@article{criollo_gaghan_john_orozco_thachil_crespo_kulkarni_2023, title={Immune Response Evaluation in Commercial Turkeys Affected with Clostridial Dermatitis}, volume={67}, ISSN={["1938-4351"]}, DOI={10.1637/aviandiseases-D-22-00089}, abstractNote={Evaluación de la respuesta inmune en pavos comerciales afectados por dermatitis clostridial. La dermatitis clostridial (CD), causada por Clostridium septicum y Clostridium perfringens, es una enfermedad emergente económicamente importante de los pavos caracterizada por muerte súbitas y dermatitis necrótica. Se conoce poco acerca de las respuestas inmunitarias en pavos comerciales afectados por dermatitis clostridial. En el presente estudio, se aisló C. septicum de pavos comerciales afectados por dermatitis clostridial durante un brote reciente, y los tejidos (piel, músculo y bazo) se recolectaron y analizaron para determinar la expresión de genes inmunitarios junto con muestras de aves clínicamente sanas. Los resultados mostraron que los pavos afectados por dermatitis clostridial tenían niveles significativamente más altos de transcritos de IL-1β, IL-6, IFNγ, and iNOS en los tejidos de la piel, los músculos y el bazo en comparación con las aves sanas. Los pavos afectados también tenían una transcripción significativamente elevada del gene del receptor tipo toll (TLR21) en los tejidos de la piel y el bazo, lo que sugiere un papel de este receptor en el reconocimiento inmunitario. La expresión de los genes IL-4 e IL-13 en el bazo y el músculo también fue significativamente mayor en las aves afectadas. Aves adicionales de las mismas granjas afectadas y sanas que fueron examinadas por serología revelaron que los pavos afectados por dermatitis clostridial tenían niveles significativamente más altos de anticuerpos séricos IgM e IgY. Además, la estimulación in vitro de los macrófagos MQ-NCSU con C. septicum condujo a una regulación transcripcional significativamente al alza de los genes IL-1β and IFNγ, mientras que la expresión del gene IL-10 se reguló a la baja. La expresión superficial de la proteína MHC-II y la producción celular de óxido nítrico también aumentaron significativamente en los macrófagos estimulados por C. septicum, lo que indica activación celular. Colectivamente, estos hallazgos sugieren que las respuestas del huésped en pavos afectados por dermatitis clostridial implican una respuesta inflamatoria robusta, así como una respuesta mediada por citoquinas IL4/IL-13 que pueden ayudar en la inmunidad mediada por anticuerpos.}, number={1}, journal={AVIAN DISEASES}, author={Criollo, Valeria and Gaghan, Carissa and John, Feba and Orozco, Eric and Thachil, Anil and Crespo, Rocio and Kulkarni, Raveendra R.}, year={2023}, month={Mar}, pages={80–88} }
 @article{smith_cornell_crossley_crespo_jones_snyder_owen_2023, title={Wind Speed and Landscape Context Mediate Campylobacter Risk among Poultry Reared in Open Environments}, url={https://doi.org/10.3390/ani13030492}, DOI={10.3390/ani13030492}, abstractNote={Foodborne pathogens cause over 9 million illnesses in the United States each year, and Campylobacter from chickens is the largest contributor. Rearing poultry outdoors without the use of antibiotics is becoming an increasingly popular style of farming; however, little is understood about how environmental factors and farm management alter pathogen prevalence. Our survey of 27 farms in California, Oregon, Washington, and Idaho, USA, revealed a diversity of management practices used to rear poultry in the open environment. Here, we assess environmental and management factors that impact Campylobacter spp. prevalence in 962 individual chicken fecal samples from 62 flocks over a three-year period. We detected Campylobacter spp. in 250/962 (26.0%) of fecal samples screened, in 69.4% (43/62) of flocks, and on 85.2% (23/27) of farms. We found that Campylobacter spp. prevalence was predicted to increase in poultry on farms with higher average wind speeds in the seven days preceding sampling; on farms embedded in more agricultural landscapes; and in flocks typified by younger birds, more rotations, higher flock densities, and the production of broilers. Collectively, our results suggest that farms in areas with higher wind speeds and more surrounding agriculture face greater risk of Campylobacter spp. introduction into their flocks.}, journal={Animals}, author={Smith, Olivia M. and Cornell, Kevin A. and Crossley, Michael S. and Crespo, Rocio and Jones, Matthew S. and Snyder, William E. and Owen, Jeb P.}, year={2023}, month={Jan} }
 @article{adams_kulkarni_mohammed_crespo_2022, title={A flow cytometric method for enumeration and speciation of coccidia affecting broiler chickens}, volume={301}, ISSN={["1873-2550"]}, url={https://doi.org/10.1016/j.vetpar.2021.109634}, DOI={10.1016/j.vetpar.2021.109634}, abstractNote={Production losses, mortality, and control measures associated with coccidiosis, caused by Eimera species, cost the broiler industry over $14 billion a year. Current means to distinguish Eimeria species such as oocyst morphology, pre-patent period and site of infection are subjective, labor intensive or unsuitable for high-throughput applications. Although Polymerase Chain Reaction (PCR) techniques have been validated, the target gene cannot differentiate relative abundance of each species in mixed infections. In this study, we developed a non-antibody-based flow cytometry high throughput method to simultaneously enumerate and speciate four Eimeria species, E. acervulina, E. mitis, E. maxima, and E. tenella, using commercial coccidia vaccine as well as field fecal samples. Our findings showed that the four Eimeria oocyst populations could be distinctly speciated based on their size and granularity (shape) via scatter plotting. These distinct populations were sorted and confirmed by quantitative real-time PCR assay. Finally, the flow cytometry findings were applied to enumerate and speciate oocysts from fecal samples collected from commercial broiler flocks vaccinated for coccidiosis at day of hatch and the results were validated against the conventional manual method of floatation and microscopic examination. Collectively, the findings of this study suggested that non-antibody based Flow Cytometry technique can be successful in the simultaneous enumeration and speciation of coccidia. Further development and validation is needed to make this diagnostic tool useful for field applications at a much larger scale as well as to speciate other Eimeria species.}, journal={VETERINARY PARASITOLOGY}, publisher={Elsevier BV}, author={Adams, Daniel S. and Kulkarni, Raveendra R. and Mohammed, Javid P. and Crespo, Rocio}, year={2022}, month={Jan} }
 @article{gaghan_adams_mohammed_crespo_livingston_kulkarni_2022, title={Characterization of vaccine-induced immune responses against coccidiosis in broiler chickens}, volume={40}, ISSN={["1873-2518"]}, url={https://doi.org/10.1016/j.vaccine.2022.05.043}, DOI={10.1016/j.vaccine.2022.05.043}, abstractNote={Coccidiosis, caused by Eimeria protozoan species, is an economically important enteric disease of poultry. Although commercial live vaccines are widely used for disease control, the vaccine-induced protective immune mechanisms are poorly characterized. The present study used a commercial broiler vaccine containing a mixture of E. acervulina, E. maxima, and E. tenella. One-day-old chicks were vaccinated by spray followed by a challenge at 21 days of age with a mixture of wild type Eimeria species via oral gavage. Oocyst shedding, immune gene expression and cellular responses in the spleen and cecal tonsils were measured at pre- (days 14 and 21) and post-challenge (days 24, 28 and 35) time points. Results showed that the oocyst counts were significantly reduced in the vaccinated chickens at post-challenge compared to unvaccinated control group. While the vaccinated birds had a significantly increased toll-like receptor (TLR) 21 gene expression at pre-challenge, the transcription of interferon (IFN)γ, Interleukin (IL)-12 and CD40 genes in spleen and cecal tonsils of these birds was significantly higher at post-challenge compared to unvaccinated chickens. Cellular immunophenotyping analysis found that vaccination led to increased frequency of macrophages and activated T cells (CD8+CD44+ and CD4+CD44+) in the spleen and cecal tonsils at post-challenge. Furthermore, in vitro stimulation of chicken macrophages (MQ-NCSU cells) with purified individual species of E. acervulina, E. maxima, and E. tenella showed a significantly increased expression of TLR21, TLR2 and IFNγ genes as well as nitric oxide production. Collectively, these findings suggest that TLR21 and TLR2 may be involved in the immune cell recognition of Eimeria parasites and that the vaccine can induce a robust macrophage activation leading to a T helper-1 dominated protective response at both local and systemic lymphoid tissues.}, number={29}, journal={VACCINE}, publisher={Elsevier BV}, author={Gaghan, Carissa and Adams, Daniel and Mohammed, Javid and Crespo, Rocio and Livingston, Kimberly and Kulkarni, Raveendra R.}, year={2022}, month={Jun}, pages={3893–3902} }
 @article{chambless_cornell_crespo_snyder_owen_2022, title={Diversity and Prevalence of Ectoparasites on Poultry from Open Environment Farms in the Western-United States of Washington, Idaho, Oregon, and California}, volume={7}, ISSN={["1938-2928"]}, DOI={10.1093/jme/tjac093}, abstractNote={Abstract Open-environment poultry farms that allow chickens to forage outdoors are becoming increasingly common throughout the United States and Europe; however, there is little information regarding the diversity and prevalence of ectoparasites in these farming systems. Eight to 25 birds were captured and surveyed for ectoparasites on each of 17 farms across the states of Washington, Idaho, Oregon, and California. Among the farms sampled, six louse species (Phthiraptera: Ischnocera & Amblycera) and two parasitic mite species (Acari: Mesostigmata) were collected and identified: Goniodes gigas (Taschenberg, 1879; Phthiraptera: Menoponidae) on one farm, Menacathus cornutus (Schömmer, 1913; Phthiraptera: Menoponidae) on one farm, Menopon gallinae (Linnaeus, 1758; Phthiraptera: Menoponidae) on six farms, Lipeurus caponis (Linnaeus, 1758; Phthiraptera: Philopteridae) on five farms, Menacanthus stramineus (Nitzsch, 1818; Phthiraptera: Menoponidae) on nine farms, Goniocotes gallinae De Geer (Phthiraptera: Philopteridae) on 11 farms, Dermanyssus gallinae (De Geer, 1778; Mesostigmata: Dermanyssidae) on two farms, and Ornithonyssus sylviarum (Canestrini & Fanzago, 1877; Mesostigmata: Macronyssidae) on one farm. The diversity of ectoparasites on these open environment poultry farms highlights a need for additional research on ectoparasite prevalence and intensity in these poultry farming systems.}, journal={JOURNAL OF MEDICAL ENTOMOLOGY}, author={Chambless, Kendra N. and Cornell, Kevin A. and Crespo, Rocio and Snyder, William E. and Owen, Jeb P.}, year={2022}, month={Jul} }
 @article{boyett_crespo_vinueza_gaghan_mohammed_kulkarni_2022, title={Enumeration and speciation of coccidia affecting turkeys using flow cytometry method}, volume={31}, ISSN={["1537-0437"]}, url={https://doi.org/10.1016/j.japr.2022.100270}, DOI={10.1016/j.japr.2022.100270}, abstractNote={Enumeration of Eimeria oocysts is a common practice in monitoring coccidiosis in turkeys; however, the conventional method of manual microscopic examination of Eimeria oocysts is time-consuming. Previously, we used flow cytometry ( FCM ) to enumerate and speciate coccidia affecting chickens and here, we extended those findings to turkey coccidia species, E. adenoides and E. meleagrimitis . Using FCM, a commercial vaccine containing these species was used to optimize the scatter-plot parameters, including Forward-(size) and Side-(shape/granularity) scatter Area, Height, and Width patterns for Eimeria . The two Eimeria species populations in the vaccine were accurately phenotyped and the gated populations were then sorted using a Cell sorter instrument to obtain pure oocyst suspensions. The individual Eimeria species identity of sorted oocysts was confirmed by PCR using species-specific primers. A significant ( P = 0.0466) correlation (R = 0.9893) in the total oocyst count between FCM and manual methods were observed. Furthermore, when FCM was employed to analyze farm fecal samples, the close similarities in the oocyst morphologies coupled with organic debris particulate interference prevented a precise separation of these 2 species resulting in a lack of oocyst count ( OPG ) correlation between the 2 methods. The OPG counts by FCM were much lower than the manual method; however, a partial OPG trend between the two methods was observed only at the early timepoint collections during a period of 35 d. Collectively, our findings showed that FCM can be used in the enumeration of turkey Eimeria oocysts with a potential scope for a more precise enumeration and speciation in field samples.}, number={3}, journal={JOURNAL OF APPLIED POULTRY RESEARCH}, publisher={Elsevier BV}, author={Boyett, Taylor and Crespo, Rocio and Vinueza, Valeria C. and Gaghan, Carissa and Mohammed, Javid P. and Kulkarni, Raveendra R.}, year={2022}, month={Sep} }
 @article{adams_gruber_sather_correa_crespo_2022, title={Evaluation of Growing Turkey Blood Biochemistry Panel Measured Using the VetScan VS2}, url={https://doi.org/10.3390/poultry1020012}, DOI={10.3390/poultry1020012}, abstractNote={Point-of-care analyzers such as the Vetscan VS2 (VS2) that provide fast results are becoming an important tool in a variety of clinical and research settings. Several studies have explored the use of the VS2 to evaluate blood chemistry values in chickens; however, the VS2 analyzer has not yet been tested in turkeys. The first objective of this study was to utilize the VS2 to evaluate possible time-dependent changes in biochemical blood analytes over time, such as glucose, calcium, or sodium. Blood samples from 30 turkeys were analyzed with the VS2 at three time points (0, 15–20, and 40–60 min post collection), and it was found that the blood biochemistry values were stable when stored at 4 °C and analyzed within 60 min of collection. Next, we assessed the agreement between the VS2 portable analyzer and the reference benchtop analyzer (Cobas c501) and found that all of the blood analytes were comparable between both analyzers. Finally, we determined reference intervals using 120 blood samples collected from turkeys in the brooding period (0–7 days) and 118 samples collected from turkeys in the growing period (1–12 weeks). Although the values were compared to the published data, the understanding of any observed differences was challenging because reference intervals for the biochemical values in turkeys are limited, and the origin of these interval values could not be traced. Significant differences in the whole blood analytes were noted between brooding and growing birds. This study offers reassurance of the validity of the use of portable analyzers in the field for turkey veterinarians. We conclude that the VS2 can be used to measure biochemical analytes in turkeys and provide the first reference intervals for brooding and growing turkeys using this instrument.}, journal={Poultry}, author={Adams, Daniel and Gruber, Erika and Sather, Hannah and Correa, Maria and Crespo, Rocio}, year={2022}, month={Jun} }
 @article{adams_ruiz-jimenez_fletcher_gall_crespo_2022, title={Image analysis for Eimeria oocyst counts and classification}, volume={31}, ISSN={["1537-0437"]}, DOI={10.1016/j.japr.2022.100260}, abstractNote={The McMaster counting technique is the standard method used to enumerate coccidia oocysts in poultry flocks. It also allows for speciation of coccidia according to the size of their oocysts. The McMaster is a manual technique, which can be tedious and time-consuming. In this study, we present a method for quantification and classification of Eimeria using the image processing program, FIJI ImageJ (ImageJ). We compared 34 litter samples from different poultry houses. Oocysts were loaded and floated into a McMaster chamber, where they were counted manually and by ImageJ. When the software settings were used to count all oocysts without size consideration, statistical differences were found between the two techniques; however, when the parameters were set to identify specific oocyst size and cirularity, no significant statistical differences were found between results from McMaster counting technique and ImageJ. Taking the sum of the individual oocysts sizes (small, medium, and large) provided a total count that was similar to the total count obtained using the manual method. Furthermore, no statistical differences were found in the counts of Eimeria sp. oocysts by either method. However, a small but statistically significant difference was found between counts obtained using the two methods for the medium size oocysts (tentatively classified as E. necatrix, E. precox, and E. tenella together) . Overall, automatic counting using ImageJ was demonstrated to be an accurate and rapid method for counting and speciating Eimeria .}, number={3}, journal={JOURNAL OF APPLIED POULTRY RESEARCH}, author={Adams, Daniel S. and Ruiz-Jimenez, Fernando and Fletcher, Oscar J. and Gall, Sezny and Crespo, Rocio}, year={2022}, month={Sep} }
 @article{gonzalez-morales_thomson_petritz_crespo_haija_santangelo_schal_2022, title={Systemic veterinary drugs for control of the common bed bug, Cimex lectularius, in poultry farms}, volume={15}, ISSN={["1756-3305"]}, DOI={10.1186/s13071-022-05555-6}, abstractNote={The common bed bug, Cimex lectularius L., is a hematophagous ectoparasite that was a common pest in poultry farms through the 1960s. Dichlorodiphenyltrichloroethane (DDT) and organophosphates eradicated most infestations, but concurrent with their global resurgence as human ectoparasites, infestations of bed bugs have been reappearing in poultry farms. Although the impact of bed bugs on chicken health has not been quantified, frequent biting and blood-feeding are expected to cause stress, infections and even anemia in birds. Bed bug control options are limited due to the sensitive nature of the poultry environment, limited products labeled for bed bug control and resistance of bed bug populations to a broad spectrum of active ingredients. Veterinary drugs are commonly used to control endo- and ectoparasites in animals. In this study, we evaluated the effects of two common veterinary drugs on bed bugs by treating the host with systemic antiparasitic drugs.We conducted dose-response studies of ivermectin and fluralaner against several bed bug strains using a membrane feeding system. Also, different doses of these drugs were given to chickens and two delivery methods (topical treatment and ingestion) were used to evaluate the efficacy of ivermectin and fluralaner on bed bug mortality.Using an artificial feeding system, both ivermectin and fluralaner caused high mortality in insecticide-susceptible bed bugs, and fluralaner was found to be effective on pyrethroid- and fipronil-resistant bed bugs. Ivermectin was ineffective in chickens either by the topical treatment or ingestion, whereas bed bugs that fed on chickens which had ingested fluralaner suffered high mortality when feeding on these chickens for up to 28 days post treatment.These findings suggest that systemic ectoparasitic drugs have great potential for practical use to control bed bug infestations in poultry farms. These findings also demonstrate the efficacy of fluralaner (and potentially other isoxazolines) as a potent new active ingredient for bed bug control.}, number={1}, journal={PARASITES & VECTORS}, author={Gonzalez-Morales, Maria A. and Thomson, Andrea E. and Petritz, Olivia A. and Crespo, Rocio and Haija, Ahmed and Santangelo, Richard G. and Schal, Coby}, year={2022}, month={Nov} }
 @article{ruiz-jimenez_gruber_correa_crespo_2021, title={Comparison of portable and conventional laboratory analyzers for biochemical tests in chickens}, volume={100}, ISSN={["1525-3171"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85098113653&partnerID=MN8TOARS}, DOI={10.1016/j.psj.2020.11.060}, abstractNote={Antemortem blood biochemical and blood gas analyses are routinely used in health screening and diagnosis of disease in domestic veterinary species. These testing modalities are not routinely performed in poultry, in part, due to the distance from the diagnostic laboratory. Portable blood analyzers such as the i-STAT and VetScan (VS2) can be used to obtain results on the farm without delay, potentially offering a more practical option for poultry practitioners. We investigated the time effect on blood chemistry values and compared the results obtained using the i-STAT and VS2 with those obtained using conventional laboratory analyzers (GEM Premier 3000 and Cobas c501, respectively). We tested blood from 60 healthy chickens. Each sample was tested in triplicate using each of the portable analyzers and once using conventional analyzers. All samples were analyzed within 60 minutes of collection. The concentrations of some analytes were outside the limit of detection of the portable analyzers (i.e., bile acids). Although statistically significant differences were found for some biochemical analytes over time, the actual mean or median differences were too small to be considered of clinical importance. As observed in mammals, significant time-dependent changes in blood gas analytes were observed in whole blood samples exposed to ambient air. Correlation coefficients between portable and conventional analyzers were moderate to high for most of the analytes. For the most part, there was an agreement between the portable and conventional analyzers. We identified constant and proportional biases in the measurement of multiple analytes by both the i-STAT and VS2. Future studies are warranted to establish analyzer-specific reference intervals for poultry.}, number={2}, journal={POULTRY SCIENCE}, publisher={Elsevier BV}, author={Ruiz-Jimenez, Fernando and Gruber, Erika and Correa, Maria and Crespo, Rocio}, year={2021}, month={Feb}, pages={746–754} }
 @article{jara_crespo_roberts_chapman_banda_machado_2021, title={Development of a Dissemination Platform for Spatiotemporal and Phylogenetic Analysis of Avian Infectious Bronchitis Virus}, volume={8}, ISSN={["2297-1769"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85105984090&partnerID=MN8TOARS}, DOI={10.3389/fvets.2021.624233}, abstractNote={Infecting large portions of the global poultry populations, the avian infectious bronchitis virus (IBV) remains a major economic burden in North America. With more than 30 serotypes globally distributed, Arkansas, Connecticut, Delaware, Georgia, and Massachusetts are among the most predominant serotypes in the United States. Even though vaccination is widely used, the high mutation rate exhibited by IBV is continuously triggering the emergence of new viral strains and hindering control and prevention measures. For that reason, targeted strategies based on constantly updated information on the IBV circulation are necessary. Here, we sampled IBV-infected farms from one US state and collected and analyzed 65 genetic sequences coming from three different lineages along with the immunization information of each sampled farm. Phylodynamic analyses showed that IBV dispersal velocity was 12.3 km/year. The majority of IBV infections appeared to have derived from the introduction of the Arkansas DPI serotype, and the Arkansas DPI and Georgia 13 were the predominant serotypes. When analyzed against IBV sequences collected across the United States and deposited in the GenBank database, the most likely viral origin of our sequences was from the states of Alabama, Georgia, and Delaware. Information about vaccination showed that the MILDVAC-MASS+ARK vaccine was applied on 26% of the farms. Using a publicly accessible open-source tool for real-time interactive tracking of pathogen spread and evolution, we analyzed the spatiotemporal spread of IBV and developed an online reporting dashboard. Overall, our work demonstrates how the combination of genetic and spatial information could be used to track the spread and evolution of poultry diseases, providing timely information to the industry. Our results could allow producers and veterinarians to monitor in near-real time the current IBV strain circulating, making it more informative, for example, in vaccination-related decisions.}, journal={FRONTIERS IN VETERINARY SCIENCE}, author={Jara, Manuel and Crespo, Rocio and Roberts, David L. and Chapman, Ashlyn and Banda, Alejandro and Machado, Gustavo}, year={2021}, month={May} }
 @article{walker_suyemoto_hull_gall_jimenez_chen_thakur_crespo_borst_2021, title={Genomic Characterization of a Nalidixic Acid-Resistant Salmonella Enteritidis Strain Causing Persistent Infections in Broiler Chickens}, volume={8}, ISSN={["2297-1769"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85115006803&partnerID=MN8TOARS}, DOI={10.3389/fvets.2021.725737}, abstractNote={Virulent strains of Salmonella enterica subsp. enterica serovar Enteritidis (SE) harbored by poultry can cause disease in poultry flocks and potentially result in human foodborne illness. Two broiler flocks grown a year apart on the same premises experienced mortality throughout the growing period due to septicemic disease caused by SE. Gross lesions predominantly consisted of polyserositis followed by yolk sacculitis, arthritis, osteomyelitis, and spondylitis. Tissues with lesions were cultured yielding 59 SE isolates. These were genotyped by Rep-PCR followed by whole-genome sequencing (WGS) of 15 isolates which were clonal. The strain, SE_TAU19, was further characterized for antimicrobial susceptibility and virulence in a broiler embryo lethality assay. SE_TAU19 was resistant to nalidixic acid and sulfadimethoxine and was virulent to embryos with 100% mortality of all challenged broiler embryos within 3.5 days. Screening the SE_TAU19 whole-genome sequence revealed seven antimicrobial resistance (AMR) genes, 120 virulence genes, and two IncF plasmid replicons corresponding to a single, serovar-specific pSEV virulence plasmid. The pef, spv, and rck virulence genes localized to the plasmid sequence assembly. We report phenotypic and genomic features of a virulent SE strain from persistently infected broiler flocks and present a workflow for SE characterization from isolate collection to genome assembly and sequence analysis. Further SE surveillance and investigation of SE virulence in broiler chickens is warranted.}, journal={FRONTIERS IN VETERINARY SCIENCE}, author={Walker, Grayson K. K. and Suyemoto, M. Mitsu and Hull, Dawn M. M. and Gall, Sesny and Jimenez, Fernando and Chen, Laura R. R. and Thakur, Siddhartha and Crespo, Rocio and Borst, Luke B. B.}, year={2021}, month={Sep} }
 @article{ellington_hebron_crespo_machado_2021, title={Unraveling the Contact Network Patterns between Commercial Turkey Operation in North Carolina and the Distribution of <i>Salmonella</i> Species}, volume={10}, url={https://www.mdpi.com/2076-0817/10/12/1539}, DOI={10.3390/pathogens10121539}, abstractNote={Salmonellosis originating from poultry poses a significant threat to human health. Surveillance within production is thus needed to minimize risk. The objectives of this work were to investigate the distribution of Salmonella spp. from a commercial turkey operation and describe the animal movement patterns to investigate the association between contact network structure and Salmonella infection status. Four years of routine growout farm samples along with data on facility location, time since barns were built, production style, and bird movement data were utilized. From all of the surveillance samples collected, Salmonella serotyping was performed on positive samples and results showed that the most represented groups were C1 (28.67%), B (24.37%) and C2 (17.13%). The serovar Infantis (26.44%) was the most highly represented, followed by Senftenberg (12.76%) and Albany (10.93%). Results illustrated the seasonality of Salmonella presence with a higher number of positive samples being collected in the second half of each calendar year. We also demonstrated that Salmonella was more likely to occur in samples from older farms compared to farms built more recently. The contact network connectivity was low, although a few highly connected farms were identified. Results of the contact network showed that the farms which tested positive for Salmonella were not clustered within the network, suggesting that even though Salmonella dissemination occurs via transferring infected birds, for this study case it is unlikely the most important route of transmission. In conclusion, this study identified seasonality of Salmonella with significantly more cases in the second half of each year and also uncovered the role of between-farm movement of birds as not a major mode of Salmonella transmission.}, number={12}, journal={Pathogens}, author={Ellington, Cameron and Hebron, Claude and Crespo, Rocio and Machado, Gustavo}, year={2021}, month={Nov} }
 @article{livingston_cowieson_crespo_hoang_nogal_browning_livingston_2020, title={Effect of broiler genetics, age, and gender on performance and blood chemistry}, volume={6}, ISSN={["2405-8440"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85087691199&partnerID=MN8TOARS}, DOI={10.1016/j.heliyon.2020.e04400}, abstractNote={<h2>Abstract</h2> A total of 640 broilers were used to determine the effects of strain, sex, and age on hematology and blood chemistry using rapid detection devices. Day old chicks from two genetic lines of common fast-growing and high-yield broiler strains were sexed and allocated to 40 pens (16 birds per pen) containing either male or female and Ross or Cobb strains (n = 10). Venous blood was analyzed weekly using 2 broilers from each pen (n = 20) using the i-STAT® Alinity Handheld Clinical Analyzer, Zoetis Vetscan VS2, and iCheck™ Carotene devices at 14, 21, 28, 35, and 42 d, as well as growth performance. Post-mortem health tracking metrics were also recorded on 42 d. Broilers were deemed healthy based on posting data results and performed in accordance with industry standards with males presenting greater BW and reduced FCR than female broilers. Ross broilers displayed greater BW to 14 d with similar FCR compared with Cobb birds. Day of age had a highly significant impact on blood calcium, phosphorus, potassium, sodium, chloride, carotene, aspartate aminotransferase, creatine kinase, bile acids, uric acid, total protein, albumin, globulin, total carbon dioxide, hematocrit, and malondialdehyde. Male broilers had reduced blood sodium, chloride, carotene, uric acid, albumin, and increased total protein, glucose, and total carbon dioxide. Ross broilers had greater blood potassium, and sodium, as well as reduced uric acid, total protein, globulin, and malondialdehyde, compared with Cobb birds. These results demonstrated the effectiveness of point-of-care devices in measuring blood chemistry and hematology in modern broilers. These data can be utilized to determine normal healthy blood ranges in these types of broilers when accounting for strain, sex, and age.}, number={7}, journal={HELIYON}, author={Livingston, M. L. and Cowieson, A. J. and Crespo, R. and Hoang, V and Nogal, B. and Browning, M. and Livingston, K. A.}, year={2020}, month={Jul} }
 @article{cowieson_livingston_nogal_hoang_wang_crespo_livingston_2020, title={Effect of coccidial challenge and vaccination on the performance, veterinary postmortem scores, and blood biochemistry of broiler chickens}, volume={99}, ISSN={["1525-3171"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85087699065&partnerID=MN8TOARS}, DOI={10.1016/j.psj.2020.05.018}, abstractNote={A total of 960 male Cobb 500 broilers were used in a growth performance study to explore the effect of coccidial vaccination and/or coccidial challenge on blood biochemistry and veterinary postmortem metrics. Day-old chicks were randomly divided into one of the 4 experimental treatments. Treatments were arranged in a 2 × 2 factorial arrangement, with the factors being without or with vaccination (administered on day 1) or coccidial challenge (oral gavage on day 7). Growth performance was monitored on a weekly basis. Blood sample collection, as well as full veterinary necropsies, were carried out on days 6, 8, 13, 20, 27, and 34. Birds that did not receive the vaccination but were challenged with coccidiosis had higher feed conversion ratio, lower body weights, and higher mortality than the other experimental groups, and this effect was particularly evident from day 13 to day 20. Birds challenged with coccidiosis had lower plasma sodium and total carotenoid concentrations and higher potassium and globulin concentrations than nonchallenged birds. Significant interactions between age and experimental treatment for these blood parameters were observed, particularly on day 13. The necropsy results confirmed the effectiveness of the challenge and vaccination treatments, wherein birds that were challenged had higher coccidiosis scores on day 13 and day 27 than birds that were not challenged. These results demonstrate the potential for plasma sodium, potassium, total protein, total carbon dioxide, globulin, and carotenoid analysis for early diagnosis of coccidiosis in growing broiler chickens. Further work is necessary to establish whether the changes in blood biochemistry observed in the present study are transferable to alternative flocks of chicken and whether early diagnosis and intervention may mitigate performance losses associated with this disease.}, number={8}, journal={POULTRY SCIENCE}, author={Cowieson, A. J. and Livingston, M. L. and Nogal, B. and Hoang, V and Wang, Y-T and Crespo, R. and Livingston, K. A.}, year={2020}, month={Aug}, pages={3831–3840} }
 @article{shah_board_crespo_guard_paul_faux_2020, title={The occurrence of Salmonella, extended-spectrum β-lactamase producing Escherichia coli and carbapenem resistant non-fermenting Gram-negative bacteria in a backyard poultry flock environment}, volume={67}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85088388846&partnerID=MN8TOARS}, DOI={10.1111/zph.12756}, abstractNote={Increase in the number of small-scale backyard poultry flocks in the USA has substantially increased human-to-live poultry contact, leading to increased public health risks of the transmission of multi-drug resistant (MDR) zoonotic and food-borne bacteria. The objective of this study was to detect the occurrence of Salmonella and MDR Gram-negative bacteria (GNB) in the backyard poultry flock environment. A total of 34 backyard poultry flocks in Washington State (WA) were sampled. From each flock, one composite coop sample and three drag swabs from nest floor, waterer-feeder, and a random site with visible faecal smearing, respectively, were collected. The samples were processed for isolation of Salmonella and other fermenting and non-fermenting GNB under ceftiofur selection. Each isolate was identified to species level using MALDI-TOFF and tested for resistance against 16 antibiotics belonging to eight antibiotic classes. Salmonella serovar 1,4,[5],12:i:- was isolated from one (3%) out of 34 flocks. Additionally, a total of 133 ceftiofur resistant (CefR ) GNB including Escherichia coli (53), Acinetobacter spp. (45), Pseudomonas spp. (22), Achromobacter spp. (8), Bordetella trematum (1), Hafnia alvei (1), Ochrobactrum intermedium (1), Raoultella ornithinolytica (1), and Stenotrophomonas maltophilia (1) were isolated. Of these, 110 (82%) isolates displayed MDR. Each flock was found positive for the presence of one or more CefR GNB. Several MDR E. coli (n = 15) were identified as extended-spectrum β-lactamase (ESBL) positive. Carbapenem resistance was detected in non-fermenting GNB including Acinetobacter spp. (n = 20), Pseudomonas spp. (n = 11) and Stenotrophomonas maltophila (n = 1). ESBL positive E. coli and carbapenem resistant non-fermenting GNB are widespread in the backyard poultry flock environment in WA State. These GNB are known to cause opportunistic infections, especially in immunocompromised hosts. Better understanding of the ecology and epidemiology of these GNB in the backyard poultry flock settings is needed to identify potential risks of transmission to people in proximity.}, number={6}, journal={Zoonoses and Public Health}, author={Shah, D.H. and Board, M.M. and Crespo, R. and Guard, J. and Paul, N.C. and Faux, C.}, year={2020}, pages={742–753} }
 @article{crespo_dowd_varland_ford_hamer_2019, title={Bacterial Diversity in Feces of Wild Bald Eagles, Turkey Vultures and Common Ravens from the Pacific Northwest Coast, U.S.A}, volume={1}, url={https://doi.org/10.1101/511147}, DOI={10.1101/511147}, abstractNote={Abstract Birds harbor diverse microorganisms in their guts, which collectively fulfill important roles in providing their hosts with nutrition and protection from pathogens. Although numerous studies have investigated the presence of certain pathogenic bacteria in the feces of wild birds, only a few have attempted to investigate the microbiota of the gut. This study analyzed the avian bacteria present in the cloaca of avian scavengers captured on coastal beaches of Washington and Oregon between 2013 and 2015: 10 turkey vultures ( Cathartes aura ), 9 bald eagles ( Haliaeetus leucocephalus ), and 2 common ravens ( Corvus corax ). We used illumina sequencing based on the V4 region of the 16s gene was to characterize the bacterial diversity. Our investigation revealed phylum-level differences in the microbiome of turkey vultures, compared with bald eagles and common ravens. Substantial microbiome differences were found between bald eagles and ravens below the phylum level. Although little is known about the possible relations among these microorganisms, our analyses provides the first integrated look at the composition of the avian microbiota and serves as a foundation for future studies in this area.}, journal={bioRxiv}, publisher={Cold Spring Harbor Laboratory}, author={Crespo, Rocio and Dowd, Scot E and Varland, Daniel E. and Ford, Scott and Hamer, Thomas E.}, year={2019}, month={Jan} }
 @article{groff_lorenz_crespo_iezhova_valkiūnas_sehgal_2019, title={Haemoproteosis lethality in a woodpecker, with molecular and morphological characterization of Haemoproteus velans (Haemosporida, Haemoproteidae)}, volume={10}, ISSN={2213-2244}, url={http://dx.doi.org/10.1016/j.ijppaw.2019.07.007}, DOI={10.1016/j.ijppaw.2019.07.007}, abstractNote={A juvenile White-headed woodpecker (Dryobates albolarvatus) fitted with a radio tag was located dead at approximately 22-days post-fledging in Yakima county in central Washington in July 2015. Postmortem examination revealed an enlarged liver and spleen plus evidence of iron sequestration. Microscopic examination observed young gametocytes within the cytoplasm of erythrocytes, and exo-erythrocytic meronts within the cytoplasm of capillary endothelial cells, hepatocytes, and myocytes, and free in the tissues. These attributes implicated a haemosporidian infection that likely resulted in mortality. Subsequent sampling results of local woodpecker species in the same area during the breeding season in June-July 2016 and May-July 2017 showed other individuals infected with Haemoproteus parasites. Nested Polymerase Chain Reaction (PCR), sequencing, and microscopic analyses for avian haemosporidians revealed infections with Haemoproteus velans (Haemosporida, Haemoproteidae). This parasite was characterized molecularly and morphologically. This is the first report of a haemosporidian infection in a White-headed woodpecker anywhere in its range, and the first reported suspected mortality from haemoproteosis for a woodpecker (Piciformes, Picidae). The use of radio-tagged birds is an asset in wildlife haemosporidian studies because the effect of the pathogen can be monitored in real time. Additionally, this methodology provides opportunities to collect fresh material for microscopic and histological examination from wild birds that have died from natural causes.}, journal={International Journal for Parasitology: Parasites and Wildlife}, publisher={Elsevier BV}, author={Groff, Tierra C. and Lorenz, Teresa J. and Crespo, Rocio and Iezhova, Tatjana and Valkiūnas, Gediminas and Sehgal, Ravinder N.M.}, year={2019}, month={Dec}, pages={93–100} }
 @article{crespo_bland_opriessnig_2019, title={Use of Commercial Swine Live Attenuated Vaccine to Control an Erysipelothrix rhusiopathiae Outbreak in Commercial Cage-Free Layer Chickens}, volume={63}, ISSN={["1938-4351"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85078321343&partnerID=MN8TOARS}, DOI={10.1637/12004-112118-Case.1}, abstractNote={Erysipelothrix rhusiopathiae septicemia was diagnosed in three cage-free commercial layer flocks from Washington State that experienced an increase in mortality and slight drop in egg production. Erysipelothrix rhusiopathiae was isolated from multiple organs and from environmental samples. An agar gel diffusion test of several E. rhusiopathiae isolates confirmed the presence of serotype 1b, and multiplex real-time PCR of the surface protective antigen (Spa) gene confirmed presence of SpaA. Bacitracin administered via the water reduced mortality minimally and only for a short period of time. Mortality was finally controlled by vaccination with a live attenuated swine E. rhusiopathiae vaccine delivered via the drinking water. This is the first report describing the use of an attenuated vaccine to control an E. rhusiopathiae outbreak in a chicken flock.Reporte de caso- Uso de vacunas vivas atenuadas comerciales para uso en porcinos para controlar un brote de Erysipelothrix rhusiopathiae en aves de postura libres de jaula. Septicemia por Erysipelothrix rhusiopathiae se diagnosticó en tres parvadas comerciales libres de jaula en el estado de Washington que experimentaron un aumento de la mortalidad y una leve disminución en la producción de huevos. Se aisló Erysipelothrix rhusiopathiae de múltiples órganos y de muestras ambientales. La prueba de difusión en gel de agar de varios aislamientos de E. rhusiopathiae confirmó la presencia del serotipo 1b y un método múltiple de PCR en tiempo real del gene del antígeno protector de superficie (Spa) confirmó la presencia de SpaA. La bacitracina administrada a través del agua redujo la mortalidad en forma mínima y solo durante un tiempo corto. La mortalidad finalmente se controló mediante la vacunación con una vacuna viva atenuada de E. rhusiopathiae para porcinos administrada a través del agua de bebida. Este es el primer reporte que describe el uso de una vacuna atenuada para controlar un brote de E. rhusiopathiae en una parvada de pollos.}, number={3}, journal={AVIAN DISEASES}, author={Crespo, Rocio and Bland, Mark and Opriessnig, Tanja}, year={2019}, month={Sep}, pages={520–524} }
 @article{board_crespo_shah_faux_2018, title={Biochemical Reference Intervals for Backyard Hens}, volume={32}, ISSN={["1938-2871"]}, DOI={10.1647/2018-301}, number={4}, journal={JOURNAL OF AVIAN MEDICINE AND SURGERY}, author={Board, Melissa M. and Crespo, Rocio and Shah, Devendra H. and Faux, Cynthia M.}, year={2018}, month={Dec}, pages={301–306} }
 @article{board_crespo_shah_faux_2018, title={Biochemical reference intervals for backyard hens}, volume={32}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85065516486&partnerID=MN8TOARS}, DOI={10.1647/2017-310}, abstractNote={Keeping backyard poultry has become increasingly popular in urban and suburban households. With this rise in popularity comes an increased need for veterinarians who are willing to serve this demographic and a need for lab reference intervals that capture the range of clinically healthy backyard hens. We developed blood chemistry reference intervals for birds in backyard chicken flocks. Between June and August 2016, 133 adult, actively laying hens from 34 different flocks in Western Washington were sampled via medial metatarsal venipuncture. Whole heparinized blood was analyzed using a VetScan VS2 with Avian/Reptilian Profile Plus reagent rotors. Packed cell volume was determined via centrifugation of microhematocrit tubes. Reference intervals were calculated by Reference Value Advisor V2.1 software using the nonparametric method. Seven currently published reference intervals for the Gallus gallus domesticus could not be validated for use in backyard hens, according to the guidelines established by the Clinical and Laboratory Standards Institute. Of flock owners who participated in the study, 47% reported they would consider paying for a blood test if a veterinarian thought it would be beneficial.}, number={4}, journal={Journal of Avian Medicine and Surgery}, author={Board, M.M. and Crespo, R. and Shah, D.H. and Faux, C.M.}, year={2018}, pages={301–306} }
 @inbook{crespo_frança_fenton_shivaprasad_2018, title={Galliformes and Columbiformes}, ISBN={9780128053065}, url={http://dx.doi.org/10.1016/b978-0-12-805306-5.00031-6}, DOI={10.1016/b978-0-12-805306-5.00031-6}, abstractNote={Abstract Galliformes and columbifomes are closely associated with humans and some species have been domesticated for well over 5000 years. Both orders remain diverse, ranging from the common domestic poultry species (e.g., chicken, turkey, and squabs) to the more exotic species found in the wild and in zoological collections. While many species have been benefited from human activities and have increased their ranges, others have declined in numbers and some have become threatened (e.g., Trinidad piping-guan and wood quail) or even extinct (e.g., dodo and passenger pigeon). Nondomestic galliformes and columbiformes are susceptible to many of the same diseases that occur in domestic species, yet predisposition may be different. Furthermore, disease prevalence depends on exposure and potential risk factors. Infectious diseases that tend to be more common under intensive commercial production may not pose as great a risk to exotic and free-living species.}, booktitle={Pathology of Wildlife and Zoo Animals}, publisher={Elsevier}, author={Crespo, Rocio and França, Monique S. and Fenton, Heather and Shivaprasad, H.L.}, year={2018}, pages={747–773} }
 @article{crespo_badcoe_williams_bary_2016, title={Inactivation of Infectious Bursal Disease Virus Through Composting of Litter from Poultry Houses}, volume={60}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/11341-120615-resnote}, DOI={10.1637/11341-120615-resnote}, abstractNote={Very virulent infectious bursal disease virus (vvIBDV) was diagnosed in a pullet farm in Washington in 2014. Infectious bursal disease virus is resistant to many environmental stresses and often persists on farms for months. There have been conflicting reports as to whether composting can destroy vvIBDV in the manure. This project investigated the composting of litter from the affected house using an aerated static pile to inactivate the virus. Two weeks before the affected pullet flocks were moved to the layer house, specific-pathogen-free (SPF) birds were placed in the barns. Ten days after they were placed, three SPF birds died and were positive for vvIBDV. Thirty percent of the SPF birds were positive for vvIBDV. After the pullets were moved, at 20 wk of age, the litter in the house was composted using the aerated static pile method. The pile was maintained at above 55 C for 4 wk. After this time, 30 additional SPF birds were placed on the composted material. Two weeks later, the birds were healthy and there was no evidence of vvIBDV. The subsequent pullet flock did not break with vvIBDV. These results demonstrate that this composting method can be used to decontaminate the litter from vvIBDV and help prevent the spread of vvIBDV.}, number={2}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Badcoe, Lyndon M. and Williams, Cheryl and Bary, Andrew I.}, year={2016}, month={Jun}, pages={506–510} }
 @article{shah_paul_sischo_crespo_guard_2016, title={Population dynamics and antimicrobial resistance of the most prevalent poultry-associated Salmonella serotypes}, volume={96}, ISSN={0032-5791 1525-3171}, url={http://dx.doi.org/10.3382/ps/pew342}, DOI={10.3382/ps/pew342}, abstractNote={Salmonella spp. is the most predominant bacterial cause of foodborne gastroenteritis in humans. Due to the risk of human infection associated with poultry products and the prevalence of antimicrobial resistance, Salmonella also poses a significant challenge to commercial poultry production. During the last decade (2002 to 2012), the 12 most prevalent poultry-associated Salmonella serotypes (MPPSTs) were frequently and consistently isolated from poultry products in the United States. These MPPSTs and their percent prevalence in poultry products include Kentucky (4%), Enteritidis (2%) Heidelberg (2%), Typhimurium (2%), S. I 4,[5],12:i:- (0.31%), Montevideo (0.20%), Infantis (0.16%) Schwarzengrund (0.15%), Hadar (0.15%), Mbandaka (0.13%), Thompson (0.12%), and Senftenberg (0.04%). All MPPSTs except Kentucky are among the top 30 clinically significant serotypes that cause human illnesses in the United States. However with the exception of a few widely studied serotypes such as S. Enteritidis and Typhimurium, the ecology and epidemiology of the majority of MPPSTs still remain poorly investigated. Published data from the United States suggests that MPPSTs such as Heidelberg, Typhimurium, Kentucky, and Sentfenberg are more likely to be multi-drug resistant (MDR, ≥3 antimicobial classes) whereas Enteritidis, Montevideo, Schwarzengrund, Hadar, Infantis, Thompson, and Mbandaka are generally pan-susceptible or display resistance to fewer antimicobials. In contrast, the majority of MPPSTs isolated globally have been reported to display MDR phenotype. There also appears to be an international spread of a few MDR serotypes including Kentucky, Schwarzengrund, Hadar, Thomson, Sentfenberg, and Enteritidis, which may pose significant challenges to the public health. The current knowledge gaps on the ecology, epidemiology, and antimicrobial resistance of MPPSTs are discussed.}, number={3}, journal={Poultry Science}, publisher={Oxford University Press (OUP)}, author={Shah, Devendra H. and Paul, Narayan C. and Sischo, Willium C. and Crespo, Rocio and Guard, Jean}, year={2016}, month={Sep}, pages={687–702} }
 @inbook{crespo_2016, place={Whitehouse Station, New Jersey}, edition={11th}, title={Urate Deposition (Gout)}, url={http://www.merckvetmanual.com/poultry/miscellaneous-conditions-of-poultry/urate-deposition-gout-in-poultry.}, booktitle={The Merck Veterinary Manual}, publisher={Merck & Co. Inc}, author={Crespo, R.}, year={2016} }
 @article{crespo_opriessnig_uzal_gerber_2015, title={Avian Hepatitis E Virus Infection in Organic Layers}, volume={59}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/11070-032215-reg.1}, DOI={10.1637/11070-032215-reg.1}, abstractNote={Between 2012 and 2014, 141 chickens from 10 organic layer flocks with a history of severe drop in egg production (up to 40%) and slight increased mortality (up to 1% per week) were submitted to the Avian Health and Food Safety Laboratory (Puyallup, WA). At necropsy, the most common finding was pinpoint white foci on the liver and regressed ova without any other remarkable lesions. Histologically, there was multifocal mild-to-severe acute necrotizing hepatitis present. No significant bacteria were recovered from liver samples, and tests for mycotoxins were negative. Twenty-six serum samples from four affected flocks tested were positive for avian hepatitis E virus (HEV) immunoglobulin Y antibodies. Avian HEV RNA was detected in 10 livers of chickens from two different affected flocks. The avian HEV was characterized by sequencing and determined to belong to genotype 2. The diagnosis of a clinical manifest HEV was based solely on the demonstration of specific viral RNA and the absence of other causative agents in samples from flocks, as the clinical sings and pathologic lesions were atypical.}, number={3}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Opriessnig, Tanja and Uzal, Francisco and Gerber, Priscilla F.}, year={2015}, month={Sep}, pages={388–393} }
 @article{warren_weber_crespo_2015, title={Comparison of conventional plating methods and Petrifilm for the recovery of aerobic bacteria and mold from hatchery fluff samples}, volume={25}, ISSN={1056-6171 1537-0437}, url={http://dx.doi.org/10.3382/japr/pfv060}, DOI={10.3382/japr/pfv060}, abstractNote={SUMMARY The enumeration and evaluation of bacteria and mold are important elements in the evaluation of hatchery sanitation programs. However, detection of bacteria and mold in fluff samples is time consuming and cumbersome. The PetrifilmTM aerobic count plate (ACP) and the Petrifilm yeast/mold count plate are ready-to-use alternatives to the traditional enumeration media used for bacteria and mold associated with environment and food. The purpose of this study was to evaluate the usefulness of Petrifilms for enumeration of aerobic bacteria and mold from hatchery fluff samples. Comparisons of ACP and mold counts were performed in 25 fluff samples. These samples were from 2 commercial hatcheries. ACP comparisons were made by evaluating the standard for pour plating with plate count agar versus aerobic count plate Petrifilm. Mold comparisons were made by evaluating Sabouraud dextrose agar versus yeast/mold plate count Petrifilm. Overall equivalent bacterial counts and mold counts were obtained by both enumeration methods. Because the Petrifilm method is convenient and gave comparative results, it offers a good alternative for fluff aerobic bacteria and mold counts.}, number={1}, journal={The Journal of Applied Poultry Research}, publisher={Oxford University Press (OUP)}, author={Warren, Claire A. and Weber, Sylvia K. and Crespo, Rocio}, year={2015}, month={Nov}, pages={48–53} }
 @inbook{crespo_shivaprasad_2015, place={Hoboken, New Jersey}, title={Diagnostic Lab Sampling}, booktitle={Backyard Poultry Medicine and Surgery: A Guide for Veterinary Practitioners}, publisher={Wiley-Blackwell}, author={Crespo, R. and Shivaprasad, H.L.}, editor={Greenacre, C.B. and Morishita, T.Y.Editors}, year={2015}, pages={275–282} }
 @inbook{crespo_shivaprasad_2015, place={Hoboken, New Jersey}, title={Interpretation of Laboratory Results and Values}, booktitle={Backyard Poultry Medicine and Surgery: A Guide for Veterinary Practitioners}, publisher={Wiley-Blackwell}, author={Crespo, R. and Shivaprasad, H.L.}, editor={Greenacre, C.B. and Morishita, T.Y.Editors}, year={2015}, pages={283–296} }
 @inbook{crespo_2015, edition={2nd}, title={Laboratory Diagnostic Procedures in Poultry}, booktitle={Manual of Poultry Disease}, publisher={French Association for the Advancement of Science (AFAS)}, author={Crespo, R.}, editor={Brugere-Picoux, Jeanne and Vaillancourt, Jean-PierreEditors}, year={2015}, pages={126–133} }
 @article{ip_torchetti_crespo_kohrs_debruyn_mansfield_baszler_badcoe_bodenstein_shearn-bochsler_et al._2015, title={Novel Eurasian Highly Pathogenic Avian Influenza A H5 Viruses in Wild Birds, Washington, USA, 2014}, volume={21}, ISSN={1080-6040 1080-6059}, url={http://dx.doi.org/10.3201/eid2105.142020}, DOI={10.3201/eid2105.142020}, abstractNote={Abstract Novel Eurasian lineage avian influenza A(H5N8) virus has spread rapidly and globally since January 2014. In December 2014, H5N8 and reassortant H5N2 viruses were detected in wild birds in Washington, USA, and subsequently in backyard birds. When they infect commercial poultry, these highly pathogenic viruses pose substantial trade issues.}, number={5}, journal={Emerging Infectious Diseases}, publisher={Centers for Disease Control and Prevention (CDC)}, author={Ip, Hon S. and Torchetti, Mia Kim and Crespo, Rocio and Kohrs, Paul and DeBruyn, Paul and Mansfield, Kristin G. and Baszler, Timothy and Badcoe, Lyndon and Bodenstein, Barbara and Shearn-Bochsler, Valerie and et al.}, year={2015}, month={May}, pages={886–890} }
 @article{crespo_senties-cue_2015, title={Postmortem Survey of Disease Conditions in Backyard Poultry}, volume={24}, ISSN={1557-5063}, url={http://dx.doi.org/10.1053/j.jepm.2015.04.003}, DOI={10.1053/j.jepm.2015.04.003}, abstractNote={The laboratory information systems of the Avian Health and Food Safety Laboratory (AHFSL) and the California Animal Health and Food Safety Laboratory System (CAHFS) were analyzed to determine the disease frequency, by etiology, for backyard chicken submissions. Marek’s disease and Escherichia coli infection were by far the most common disease conditions diagnosed in both laboratories (17.7% and 17.4% at AHFSL versus 14.5% and 13.5% at CAHFS), followed by coccidiosis (AHFSL = 5.9%, CAHFS = 3.8%), ascaridiasis (AHFSL = 5.6%, CAHFS = 3.1%), and Mycoplasma gallisepticum (AHFSL = 3.2%, CAHFS = 3.6%). Neoplasia of the reproductive tract, ascites syndrome, and fatty liver hemorrhagic syndrome were found at a higher rate at AHFSL (13.9%, 8%, and 5.1%, respectively) than at CAHFS (1.6%, 1%, and 1.8%, respectively). This difference might have been related to the flock purpose and age of birds submitted. The 2 notifiable diseases of poultry, Newcastle disease and avian influenza, are rare in backyard poultry and neither of these diseases was diagnosed during the investigated period.}, number={2}, journal={Journal of Exotic Pet Medicine}, publisher={Elsevier BV}, author={Crespo, Rocio and Senties-Cue, Gabriel}, year={2015}, month={Apr}, pages={156–163} }
 @article{paul_al-adwani_crespo_shah_2014, title={Evaluation of passive immunotherapeutic efficacy of hyperimmunized egg yolk powder against intestinal colonization of Campylobacter jejuni in chickens}, volume={93}, ISSN={1525-3171 0032-5791}, url={http://dx.doi.org/10.3382/ps.2014-04234}, DOI={10.3382/ps.2014-04234}, abstractNote={Campylobacter jejuni is a leading cause of foodborne bacterial gastroenteritis in human. Chickens are the reservoir host of C. jejuni, and contaminated chicken meat is an important source of human infection. Therefore, control of C. jejuni in chickens can have direct effect on human health. In this study we tested the passive immunotherapeutic efficacy of the chicken egg-yolk-derived antibodies, in the form of hyperimmunized egg yolk powder (HEYP), against 7 colonization-associated proteins of C. jejuni, namely, CadF (Campylobacter adhesion to fibronectin), FlaA (flagellar proteins), MOMP (major outer membrane protein), FlpA (fibronectin binding protein A), CmeC (Campylobacter multidrug efflux C), Peb1A (Campylobacter putative adhesion), and JlpA (Jejuni lipoprotein A). Three chicken experiments were performed. In each experiment, chickens were treated orally via feed supplemented with 10% (wt/wt) egg yolk powder. In experiment 1, chicken groups were experimentally infected with C. jejuni (10(8) cfu) followed by treatment with 5 HEYP (CadF, FlaA, MOMP, FlpA, CmeC) for 4 d either individually or as a cocktail containing equal parts of each HEYP. In experiment 2, chickens were treated for 21 d with cocktail containing equal parts of 7 HEYP before and after experimental infection with C. jejuni (10(8) cfu). In experiment 3, chickens were treated with feed containing a cocktail of 7 HEYP before and after (prophylaxis), and after (treatment) experimental infection with C. jejuni (10(5) cfu). Intestinal colonization of C. jejuni was monitored by culturing cecal samples from chickens euthanized at the end of each experiment. The results showed that there were no differences in the cecal colonization of C. jejuni between HEYP treated and nontreated control chickens, suggesting that use of HEYP at the dose and the regimens used in the current study is not efficacious in reducing C. jejuni colonization in chickens.}, number={11}, journal={Poultry Science}, publisher={Oxford University Press (OUP)}, author={Paul, Narayan C. and Al-Adwani, Salma and Crespo, Rocio and Shah, Devendra H.}, year={2014}, month={Nov}, pages={2779–2787} }
 @article{neal-mckinney_samuelson_eucker_nissen_crespo_konkel_2014, title={Reducing Campylobacter jejuni Colonization of Poultry via Vaccination}, volume={9}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0114254}, DOI={10.1371/journal.pone.0114254}, abstractNote={Campylobacter jejuni is a leading bacterial cause of human gastrointestinal disease worldwide. While C. jejuni is a commensal organism in chickens, case-studies have demonstrated a link between infection with C. jejuni and the consumption of foods that have been cross-contaminated with raw or undercooked poultry. We hypothesized that vaccination of chickens with C. jejuni surface-exposed colonization proteins (SECPs) would reduce the ability of C. jejuni to colonize chickens, thereby reducing the contamination of poultry products at the retail level and potentially providing a safer food product for consumers. To test our hypothesis, we injected chickens with recombinant C. jejuni peptides from CadF, FlaA, FlpA, CmeC, and a CadF-FlaA-FlpA fusion protein. Seven days following challenge, chickens were necropsied and cecal contents were serially diluted and plated to determine the number of C. jejuni per gram of material. The sera from the chickens were also analyzed to determine the concentration and specificity of antibodies reactive against the C. jejuni SECPs. Vaccination of chickens with the CadF, FlaA, and FlpA peptides resulted in a reduction in the number of C. jejuni in the ceca compared to the non-vaccinated C. jejuni-challenged group. The greatest reduction in C. jejuni colonization was observed in chickens injected with the FlaA, FlpA, or CadF-FlaA-FlpA fusion proteins. Vaccination of chickens with different SECPs resulted in the production of C. jejuni-specific IgY antibodies. In summary, we show that the vaccination of poultry with individual C. jejuni SECPs or a combination of SECPs provides protection of chickens from C. jejuni colonization.}, number={12}, journal={PLoS ONE}, publisher={Public Library of Science (PLoS)}, author={Neal-McKinney, Jason M. and Samuelson, Derrick R. and Eucker, Tyson P. and Nissen, Mark S. and Crespo, Rocio and Konkel, Michael E.}, editor={Bereswill, StefanEditor}, year={2014}, month={Dec}, pages={e114254} }
 @inbook{crespo_shivaprasad_2013, place={Ames, Iowa. Pages}, edition={13th}, title={Miscellaneous diseases}, booktitle={Diseases of Poultry}, publisher={Iowa State Press}, author={Crespo, R. and Shivaprasad, H.L.}, editor={Swayne, D.Editor}, year={2013}, pages={1233–1270} }
 @article{crespo_garner_hopkins_shah_2013, title={Outbreak of Listeria monocytogenes in an urban poultry flock}, volume={9}, ISSN={1746-6148}, url={http://dx.doi.org/10.1186/1746-6148-9-204}, DOI={10.1186/1746-6148-9-204}, abstractNote={Listeria monocytogenes infection is most commonly recognized in ruminants, including cattle, sheep, and goats; but it is rarely diagnosed in poultry. This report describes an outbreak of L. monocytogenes in a backyard poultry flock. Also, it points out the importance of collaboration between veterinarians and public health departments and the possible implications of zoonotic diseases.Depression, lack of appetite, labored breathing, and increased mortality were noted for 5 months in several affected birds within the flock. The pathologic changes in the internal organs of infected birds included severe myocarditis, pericarditis, pneumonia, hepatitis, and splenitis. No lesions were noted in the brain. Gram-positive organisms were seen in histologic sections of the heart and spleen. Listeria monocytogenes was detected by real time PCR from formalin fixed heart and spleen, and was isolated from fresh lung, spleen, and liver. This isolate was identified as L. monocytogenes serotype 4b by 16S rDNA sequencing and by PCR-based serotyping assay.This is the first report describing outbreak of L. monocytogenes in backyard poultry flock in Washington State and use of molecular methods to confirm L. monocytogenes infection from formalin fixed tissues.}, number={1}, journal={BMC Veterinary Research}, publisher={Springer Nature}, author={Crespo, Rocio and Garner, Michael M and Hopkins, Sharon G and Shah, Devendra H}, year={2013}, pages={204} }
 @article{al-adwani_crespo_shah_2013, title={Production and Evaluation of Chicken Egg-Yolk-Derived Antibodies Against Campylobacter jejuni Colonization-Associated Proteins}, volume={10}, ISSN={1535-3141 1556-7125}, url={http://dx.doi.org/10.1089/fpd.2012.1313}, DOI={10.1089/fpd.2012.1313}, abstractNote={Campylobacter jejuni is one of the most important causes of foodborne gastroenteritis. Chickens are considered a reservoir host of C. jejuni, and epidemiological studies have shown that contaminated chicken meat is a primary source of human infection. The objective of this study was to produce chicken egg-yolk-derived antibody (IgY) against the five C. jejuni colonization-associated proteins or CAPs (CadF, FlaA, MOMP, FlpA, and CmeC). Recombinant C. jejuni CAPs were expressed in Escherichia coli and were purified by affinity chromatography. Specific-pathogen-free laying hens were hyperimmunized with each recombinant CAP to induce production of α-CAP-specific IgY. Egg yolks were collected from immunized and nonimmunized hens and were lyophilized to obtain egg-yolk powder (EYP) with or without α-C. jejuni CAP-specific IgY. IgY was purified from EYP, and the antibody response in serum and egg yolk was tested by indirect enzyme-linked immunosorbent assay. The α-C. jejuni CAP-specific IgY levels were significantly (p<0.05) higher in both serum and EYP obtained from immunized hens as compared with the nonimmunized hens. Each α-C. jejuni CAP-specific IgY reacted with the C. jejuni cells and recombinant CAPs as detected by immunofluorescence microscopy and Western blot assays, respectively. We also show that α-CadF, α-MOMP, and α-CmeC IgY significantly reduced adherence of C. jejuni to the chicken hepatocellular carcinoma (LMH) cells, suggesting that these α-C. jejuni CAP-specific IgY may be useful as a passive immunotherapeutic to reduce C. jejuni colonization in chickens.}, number={7}, journal={Foodborne Pathogens and Disease}, publisher={Mary Ann Liebert Inc}, author={Al-Adwani, Salma R. and Crespo, Rocio and Shah, Devendra H.}, year={2013}, month={Jul}, pages={624–631} }
 @article{crespo_franca_shivaprasad_2013, title={Ulcerative Enteritis-like Disease Associated with Clostridium sordellii in Quail}, volume={57}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/10485-010813-Case.1}, DOI={10.1637/10485-010813-case.1}, abstractNote={A natural outbreak of ulcerative enteritis-like disease associated with Clostridium sordellii was diagnosed in two commercial quail flocks. Clinical signs in the quail included anorexia, weakness, and increased mortality in the flocks. Lesions in the intestine were characterized by ulcers covered with fibrinonecrotic exudate in the small intestine and occasional hemorrhages. There were also multifocal pale areas of necrosis in the liver. Clostridium sordellii was isolated from the intestine and liver. A retrospective study of avian cases submitted to the California Animal Health and Food Safety Laboratories revealed that C. sordellii had been isolated in 45 avian submissions, most commonly in chickens and turkeys. In most of these cases the birds were diagnosed with necrotic enteritis, with or without hepatitis. Clostridium sordellii has occasionally been associated with gangrenous dermatitis in poultry, but this is the first report of enteritis in an avian species.Reporte de Caso—Enfermedad similar a la enteritis ulcerativa asociada con Clostridium sordellii en codornices.Se diagnosticó un brote natural de una enfermedad similar a enteritis ulcerativa asociada con Clostridium sordellii en dos parvadas comerciales de codornices. Los signos clínicos en las codornices incluyeron anorexia, debilidad y mortalidad aumentada en las parvadas. Las lesiones en el intestino estuvieron caracterizadas por úlceras cubiertas con exudado fibrinonecrótico en el intestino delgado y hemorragias ocasionales. En el hígado se observaron áreas pálidas de necrosis. Se aisló Clostridium sordellii del intestino y del hígado. Un estudio retrospectivo de los casos aviares remitidos a los Laboratorios de Salud Animal e Inocuidad de los Alimentos de California, reveló que se había aislado C. sordellii en 45 casos aviares, más comúnmente en pollos y pavos. En la mayoría de los casos, las aves fueron diagnosticadas con enteritis necrótica, con o sin la presencia de hepatitis. Ocasionalmente, Clostridium sordellii ha sido asociado con dermatitis gangrenosa en las aves comerciales, pero este es el primer reporte de enteritis en una especie aviar.}, number={3}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Franca, Monique and Shivaprasad, H. L.}, year={2013}, month={Sep}, pages={698–702} }
 @book{shivaprasad_crespo_2013, place={Jacksonville, FL}, title={Velogenic Newcastle-slide study set}, publisher={American Association of Avian Pathologists}, author={Shivaprasad, H.L. and Crespo, R.}, year={2013} }
 @article{crespo_schaberg_warren_2012, title={Detection of Salmonella Enteritidis (SE) Bacterin in Environmental Samples from Poultry Houses Using the RapidChek SE Immunoassay}, volume={56}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/10137-031912-case.1}, DOI={10.1637/10137-031912-case.1}, abstractNote={Environmental swabs from pullet houses were tested for the presence of Salmonella Enteritidis (SE) using the RapidChek SE immunoassay test. Of the 1162 samples tested in 2011, 20 samples were positive, but only two samples were confirmed positive for SE by culture. Seventeen positive samples were from pullet houses that had been vaccinated with SE bacterin 2 to 3 days prior to submission to the lab. This study investigated the detection of SE bacterin using the RapidChek SE test system. Swabs were inoculated with different amounts of a commercial SE bacterin. As little as 0.25 ml of the SE bacterin was sufficient to cause positive results with the RapidChek SE test. This finding emphasizes the need to perform bacterial isolation and identification when a positive result occurs using an immunoassay test.}, number={3}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Schaberg, Dennis and Warren, Claire}, year={2012}, month={Sep}, pages={621–624} }
 @article{crespo_shivaprasad_2011, title={Rupture of Gastrocnemius Tendon in Broiler Breeder Hens}, volume={55}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/9669-012711-case.1}, DOI={10.1637/9669-012711-case.1}, abstractNote={Lameness and mortality of 0.55% to 1.00% per week occurred in 32-to-33-wk-old broiler breeder hens in a complex involving eight houses. Males were not affected. Laboratory evaluation of 19 birds, over 2 wk, revealed complete rupture or partial tear, primarily of the gastrocnemius tendon; the fibularis longus, fibularis brevis, and flexor muscles and their tendons were injured in a few birds. Rupture of the gastrocnemius tendon has been observed in broiler breeder chickens older than 12 wk of age and it is characterized by lameness secondary to unilateral or bilateral rupture of the tendon. The cause of this condition has been primarily attributed to reovirus infection but rupture by other causes can also occur. In this case, there was no evidence of synovitis or reovirus infection in the birds. The cause of the ruptures was attributed to aggressive males when the ratio of males to females was increased from seven or eight males per 100 females at 22-23 wk to nine or 10 per 100 at 31 wk of age.}, number={3}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Shivaprasad, H. L.}, year={2011}, month={Sep}, pages={495–498} }
 @article{crespo_shivaprasad_2010, title={Decrease of Fertility in a Broiler Breeder Flock due to Testicular Atrophy}, volume={54}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/8876-041409-case.1}, DOI={10.1637/8876-041409-case.1}, abstractNote={Two weeks after spiking, a decrease in fertility from 96% to 82% was observed in a 48-week-old broiler breeder flock. Hatchability in the flock was about 86%. Necropsy of 25 males revealed severe testicular atrophy in 60% of the birds. Histopathology of the testes demonstrated no spermatogenesis in most of these birds. No evidence of infectious disease was discovered, and no infectious agents were isolated. Further investigation on the farm revealed standing water in the house, due to heavy rains, and wet and caked litter; this resulted in decreased feed consumption, for at least 5 days prior to submission to the diagnostic laboratory, and a corresponding decrease in body weight of the birds. In conclusion, a combination of a recent introduction of replacement (spiking) males, poor environmental conditions, and decreased feed consumption led to the loss of weight, testicular atrophy, and decreased or no spermatogenesis in individual birds, collectively resulting in decreased flock fertility.}, number={1}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Shivaprasad, H. L.}, year={2010}, month={Mar}, pages={142–145} }
 @article{crespo_faux_dhillon_newberry_moore_2010, title={Pet Poultry Training for Veterinary Practitioners}, volume={37}, ISSN={0748-321X 1943-7218}, url={http://dx.doi.org/10.3138/jvme.37.4.383}, DOI={10.3138/jvme.37.4.383}, abstractNote={Keeping backyard poultry in urban areas is a burgeoning trend in the United States. As such, we believe urban pet poultry owners are increasingly likely to seek veterinary services from urban companion-animal practitioners. Traditionally, poultry species have been classified as production animals. Most small-animal practitioners have limited experience or knowledge of these species and hesitate to accept these animals at their practices. We developed a one-day course to train veterinarians in pet poultry (as opposed to commercial poultry) medicine. The course covers poultry examination, diseases, and treatments and provides an introduction to poultry breeds and behavior and the basics of nutrition and husbandry. We believe this type of continuing education program is important for veterinarians because they are often on the front line of human public health issues. In addition, courses of this type increase the number of veterinarians trained to spot serious avian diseases, including foreign diseases and diseases with zoonotic potential. Most important, veterinarians with this training develop the knowledge to contribute to the health and well-being of pet poultry along with their clients' other companion animals.}, number={4}, journal={Journal of Veterinary Medical Education}, publisher={University of Toronto Press Inc. (UTPress)}, author={Crespo, Rocio and Faux, Cynthia and Dhillon, Singh A. and Newberry, Ruth C. and Moore, Dale A.}, year={2010}, month={Dec}, pages={383–387} }
 @article{frança_crespo_chin_woolcock_shivaprasad_2010, title={Retrospective Study of Myocarditis Associated with Reovirus in Turkeys}, volume={54}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/9262-020110-reg.1}, DOI={10.1637/9262-020110-reg.1}, abstractNote={The myocarditis associated with reovirus in commercial turkeys was studied retrospectively. Fifty-two cases were identified between 1991 and 2009. The lesions occurred in four different poultry companies in California and affected male and female turkeys with an average age of 19 days. Increased mortality in the turkey flocks ranged from 0.35% to 3% per week in 47 cases. Reovirus was isolated from the heart in 14 out of 19 cases. Twenty-four out of 28 birds from nine cases had low vitamin E levels in the liver ranging from 0.29 to 2.5 ppm (normal 3.0 to > or = 15 ppm). Transmission electron microscopy of the heart revealed degenerative changes in the myocardial cells. Reovirus has been suggested as a probable etiology of this condition. Vitamin E deficiency might also contribute to the development of the lesions.}, number={3}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={França, M. and Crespo, R. and Chin, R. and Woolcock, P. and Shivaprasad, H. L.}, year={2010}, month={Sep}, pages={1026–1031} }
 @inbook{crespo_2010, place={Whitehouse Station, New Jersey. Page}, edition={10th}, title={Urate Deposition (Gout)}, booktitle={The Merck Veterinary Manual}, publisher={Merck & Co. Inc}, author={Crespo, R.}, year={2010}, pages={2473} }
 @article{chin_garcía_corsiglia_riblet_crespo_shivaprasad_rodríguez-avila_woolcock_frança_2009, title={Intervention Strategies for Laryngotracheitis: Impact of Extended Downtime and Enhanced Biosecurity Auditing}, volume={53}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/8873-041309-reg.1}, DOI={10.1637/8873-041309-reg.1}, abstractNote={An outbreak of vaccinal infectious laryngotracheitis (LT) began in 2005 involving 57 ranches of two broiler companies in California. Standard biosecurity, and cleaning and disinfection programs along with vaccination, did not stop the outbreak. Due to the close proximity and number of birds in the same geographic area, the decision was made by both companies to attempt a joint regional and zonal depopulation strategy. The strategy involved extended downtime between flock placements on ranches located within close proximity to one another. This extended downtime on each ranch ranged from 30 to 91 days. An extensive biosecurity audit, with more than 70 items, was implemented. Briefly, this included heating all houses to 37 C for 100 hr, removing the litter, cleaning and disinfecting everything on the ranches, then again heating the houses to 37 C for 100 hr. Used litter was spread on crops away from poultry, or was sent to a litter processor for pasteurization. Extensive surveillance for LT at 28, 35, and 42 days of age was performed on the initial flocks, which had been placed immediately after the extended downtime. Since completion of this plan in early 2008, LT was diagnosed on only two of the previously 57 affected ranches. Those two ranches, and those within close proximity, went through the extended downtime program and biosecurity audit a second time. Currently, both companies are free of LT. This program lends credence to the importance of cooperation between companies to consider all the ranches within close proximity as the population at risk. In the control of LT in broilers, the program also highlights the necessity for extended downtime and enhanced biosecurity auditing of all flocks.}, number={4}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Chin, R. P. and García, M. and Corsiglia, C. and Riblet, S. and Crespo, R. and Shivaprasad, H. L. and Rodríguez-Avila, A. and Woolcock, P. R. and França, M.}, year={2009}, month={Dec}, pages={574–577} }
 @article{crespo_shivaprasad_frança_woolcock_2009, title={Isolation and Distribution of West Nile Virus in Embryonated Chicken Eggs}, volume={53}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/8829-040209-resnote.1}, DOI={10.1637/8829-040209-resnote.1}, abstractNote={West Nile virus (WNV) was identified from domestic psittacine birds by inoculating embryonated chicken eggs. Most of the embryos died 5 days postinoculation; flavivirus was detected in some by negative-staining electron microscopy. Immunohistochemistry performed on the embryos and their supporting structures detected the WNV antigen mainly in the chorioallantoic membrane, regardless of the inoculation route or passage number. WNV antigen was also found in the embryonic muscle (both skeletal and smooth muscles) and in multifocal areas of the skin. WNV was not detected in the viscera of the embryo or yolk sac. This study provides evidence of isolation and identification of WNV via embryonated chicken eggs.}, number={4}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Shivaprasad, H. L. and França, Monique and Woolcock, Peter R.}, year={2009}, month={Dec}, pages={608–612} }
 @article{crespo_subbiah_corsiglia_bickford_puschner_2008, title={Bilateral Malacia Associated with Sodium Poisoning in Turkey Poults}, volume={52}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/8025-053107-case}, DOI={10.1637/8025-053107-case}, abstractNote={Improper cleaning of the water storage tank resulted in a toxic concentration of sodium in drinking water in a commercial turkey flock. Within the first week after placement 40% of the birds in the flock died. Clinically, poults were depressed and weak, huddled together, and reluctant to walk. At necropsy the birds had crops and gizzards filled with rice hulls, moderately swollen livers, distended gall bladders, and congested lungs. Neither ascites nor round heart was observed. The major microscopic lesion was multifocal symmetrical malacia of brain and spinal cord. Laboratory results revealed a high concentration of sodium in water (2340 mg/liter). The concentration of sodium in brain and liver ranged from 1870 to 2680 (mean = 2185; SD = 321.5) mg/liter wet weight and from 1810 to 2360 (mean = 2191.67; SD = 193.2) mg/liter wet weight, respectively, whereas the normal expected sodium concentration in the brain and liver tissues from young turkeys (< 7 days old) that were submitted for other causes averaged 1233 and 983 mg/liter wet weight, respectively. Based on the histological and toxicological results, a diagnosis of salt poisoning was made. This case investigation demonstrated that sodium analysis of brain and liver are diagnostically useful when confirming sodium poisoning in young turkeys.}, number={1}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Subbiah, Murugan and Corsiglia, Charles and Bickford, Arthur and Puschner, Birgit}, year={2008}, month={Mar}, pages={179–182} }
 @article{shivaprasad_cadenas_diab_nordhausen_bradway_crespo_breitschwerdt_2008, title={Coxiella-Like Infection in Psittacines and a Toucan}, volume={52}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/8192-120707-reg}, DOI={10.1637/8192-120707-reg}, abstractNote={Seven psittacine birds and a toucan (Ramphastos toco) were diagnosed as infected with Coxiella-like bacteria, based on polymerase chain reaction and bacterial 16S rRNA gene sequence obtained from each bird's liver tissue. Most of the birds exhibited lethargy and weakness for several days prior to death. Gross lesions included mild to moderate emaciation and severely enlarged and mottled pale livers and spleens. Microscopically, there was multifocal necrosis of hepatocytes with infiltration of a mixed population of inflammatory cells, including lymphocytes, heterophils, plasma cells, and macrophages randomly scattered throughout in most birds. In several birds within the macrophages there were vacuoles containing basophilic small cocco-bacilli organisms measuring about 0.5-1 microm. The spleens had increased numbers of mononuclear phagocytic system cells, some of which had vacuoles that contained similar organisms, as observed in the liver. There was inflammation in the epicardium and endocardium, interstitium of the lungs, kidney, adrenal and thyroid glands, lamina propria of the intestine, and in occasional birds in the brain, bursa of Fabricius, and bone marrow associated with similar organisms in the macrophages. Transmission electron microscopy of the liver and lungs in most birds and in the thyroid glands of one bird revealed pleomorphic round to elongated bacteria measuring about 0.45 microm in diameter and more than 1.0 microm in length. Most of these organisms contained a peripheral zone of loosely arranged electron dense material that was located immediately beneath a trilaminar membrane. Occasional organisms contained nucleoids. This is the first documentation of disease presumptively associated with Coxiella-like bacteria in birds.}, number={3}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Shivaprasad, H. L. and Cadenas, M. B. and Diab, S. S. and Nordhausen, R. and Bradway, D. and Crespo, R. and Breitschwerdt, E. B.}, year={2008}, month={Sep}, pages={426–432} }
 @article{crespo_mcmillan_2008, title={Facial Cellulitis Induced in Chickens by Mycoplasma gallisepticum Bacterin and Its Treatment}, volume={52}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/8342-050108-case.1}, DOI={10.1637/8342-050108-case.1}, abstractNote={Ten-to-14-day-old replacement chickens were vaccinated subcutaneously in the neck with a Mycoplasma gallisepticum bacterin. A few days later, 40% of the flock developed cellulitis of the head. Birds were submitted for diagnostic investigation between 4 and 6 wk of age. Histology revealed lesions in the subcutis consistent with oil-emulsified vaccine/bacterin reaction. No significant bacteria were isolated from the lesions. Birds were treated with 1 mg of methyl prednisol acetate intramuscularly. Improvement was noted as early as 12 hr posttreatment. One week after treatment only 1%-2% of the flock still had facial cellulitis.}, number={4}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and McMillan, Richard}, year={2008}, month={Dec}, pages={698–701} }
 @article{crespo_shivaprasad_sommer_puschner_2008, title={Interaction of Ionophore and Vitamin E in Knockdown Syndrome of Turkeys}, volume={20}, ISSN={1040-6387 1943-4936}, url={http://dx.doi.org/10.1177/104063870802000409}, DOI={10.1177/104063870802000409}, abstractNote={Monensin and vitamin E concentrations, as well as histopathology of skeletal muscles and myocardium, were evaluated in broad-breasted white turkeys kept in commercial facilities. Turkeys with knockdown syndrome had myopathy of skeletal muscles, but no lesions in the myocardium. Generally, concentration of monensin in serum was highest in turkeys diagnosed with knockdown syndrome given more than 90 mg/kg of monensin in the diet, followed by turkeys diagnosed with knockdown syndrome given <90 mg/kg of monensin in the diet, healthy turkeys fed a diet that contained <90 mg/kg of monensin, and finally healthy turkeys fed a diet free of monensin (not detectable). However, the concentration of monensin was highly variable within each group, and the median was lower than the average. Vitamin E concentrations in the livers varied from low–normal to below normal and were statistically higher in healthy turkeys fed a diet free of monensin than in the livers of birds from the 3 groups exposed to monensin. This suggests that the concentration of monensin in serum positively correlates to the severity of clinical signs and pathology and to the amount of monensin in the feed. Although the methodology developed to detect serum monensin concentrations is beneficial and accurate for case investigations, it is recommended that several samples from each flock be evaluated because of variation within a flock. The current study also suggests that monensin in the feed could induce lower concentrations of vitamin E in the liver of turkeys and can predispose the turkeys to knockdown syndrome.}, number={4}, journal={Journal of Veterinary Diagnostic Investigation}, publisher={SAGE Publications}, author={Crespo, Rocio and Shivaprasad, H. L. and Sommer, Franz and Puschner, Birgit}, year={2008}, month={Jul}, pages={472–476} }
 @inbook{crespo_shivaprasad_2008, place={Ames, Iowa. Pages}, edition={12th}, title={Miscellaneous diseases}, booktitle={Diseases of Poultry}, publisher={Iowa State Press}, author={Crespo, R. and Shivaprasad, H.L.}, editor={Saif, Y.M.Editor}, year={2008}, pages={1149–1195} }
 @article{crespo_woolcock_chin_shivaprasad_garcía_2007, title={Comparison of Diagnostics Techniques in an Outbreak of Infectious Laryngotracheitis from Meat Chickens}, volume={51}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/7875-011907-regr1.1}, DOI={10.1637/7875-011907-regr1.1}, abstractNote={Various diagnostics techniques were compared for their ability to detect infectious laryngotracheitis (ILT) during an outbreak in chickens aged between 4 and 21 wk. Gross lesions ranged from excess mucus to accumulation of fibrinonecrotic exudate in the larynx and trachea. Syncytial cells with intranuclear inclusion bodies were found in sinus, conjunctiva, larynx, trachea, lung, and air sac. Virus isolation in chicken embryos was attempted in every case. Negative-stain electron microscopy detected herpesvirus in only 6% of the cases. Yet, isolation of ILT virus in the chorioallantoic membrane was presumed by histology in >20% of the samples and confirmed by fluorescent antibody (FA) in 35% of the embryos inoculated with conjunctivas or tracheas from affected birds. Overall, results from histology and FA tests were highly correlated. FA test has the advantage over histology of being diagnostically specific for ILT virus. Polymerase chain reaction was the most sensitive test and detected the viral DNA even in cases where histology and FA were negative. ILT virus DNA was quantified by real-time polymerase chain reaction (Re-Ti ILTV). Histologic and FA results from larynx and trachea were negative if the concentration of the viral DNA was ≤4 of log10. A viral DNA concentration higher than log10 4, as determined by Re-Ti ILTV, was required for clinical ILT to be manifested.}, number={4}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Woolcock, Peter R. and Chin, R. P. and Shivaprasad, H. L. and García, Maricarmen}, year={2007}, month={Dec}, pages={858–862} }
 @article{crespo_fisher_shivaprasad_fernández-miyakawa_uzal_2007, title={Toxinotypes of Clostridium Perfringens Isolated from Sick and Healthy Avian Species}, volume={19}, ISSN={1040-6387 1943-4936}, url={http://dx.doi.org/10.1177/104063870701900321}, DOI={10.1177/104063870701900321}, abstractNote={Currently, the factors/toxins responsible for Clostridium perfringens-associated avian enteritis are not well understood. To assess whether specific C. perfringens' toxinotypes are associated with avian enteritis, the isolates of C. perfringens from 31 cases of avian necrotic or ulcerative enteritis submitted between 1997 and 2005 were selected for retrospective analysis using multiplex PCR. C. perfringens was isolated from chickens, turkeys, quail, and psittacines. The toxinotypes of isolates from diseased birds were compared against the toxinotype of 19 C. perfringens isolates from avian cases with no evidence of clostridial enteritis. All C. perfringens isolates were classified as type A regardless of species or disease history. Although many isolates (from all avian groups) had the gene encoding the C. perfirngens beta2 toxin, only 54% produced the toxin in vitro when measured using Western blot analysis. Surprisingly, a large number of healthy birds (90%) carried CPB2-producing isolates, whereas over half of the cpb2-positive isolates from diseased birds failed to produce CPB2. These data from this investigation do not suggest a causal relationship between beta2 toxin and necrotic enteritis in birds.}, number={3}, journal={Journal of Veterinary Diagnostic Investigation}, publisher={SAGE Publications}, author={Crespo, Rocio and Fisher, Derek J. and Shivaprasad, H. L. and Fernández-Miyakawa, Mariano E. and Uzal, Francisco A.}, year={2007}, month={May}, pages={329–333} }
 @article{shivaprasad_cortes_crespo_2006, title={Otitis Interna (Labyrinthitis) Associated with Salmonella enterica arizonae in Turkey Poults}, volume={50}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/7379-051205r.1}, DOI={10.1637/7379-051205r.1}, abstractNote={Otitis interna was diagnosed in five 9-to-21-day-old turkey poults with clinical signs of paralysis, opisthotonus, torticollis, blindness, and increased mortality. Gross and microscopic lesions in the poults included omphalitis, typhlitis, hepatitis, meningoencephalitis, ophthalmitis, neuritis and ganglionitis of the vestibulocochlear nerve, and otitis interna. Salmonella enterica arizonae was isolated from the brains, eyes, intestines, yolk sacs, and livers of poults. Birds with otitis interna also had meningoencephalitis. It is most likely that the S. enterica arizonae infection spread from the brain to the internal ears through the vestibulocochlear nerve. This is the first documentation of otitis interna caused by bacteria in an avian species.}, number={1}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Shivaprasad, H. L. and Cortes, P. and Crespo, R.}, year={2006}, month={Mar}, pages={135–138} }
 @article{crespo_pizarro_2006, title={Skin and Abdominal Fascia Melanization in Broiler Chickens}, volume={50}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/7425-082405r.1}, DOI={10.1637/7425-082405r.1}, abstractNote={Increased trimming and consequent carcass downgrade was experienced in a broiler flock. Condemned birds had gray to black pigmentation of the subcutaneous tissue and fat of the abdomen, and bluish pigmentation of the shanks. Histopathology revealed accumulation of melanin in these tissues. No significant bacteria were isolated. Accumulation of melanin in the skin and fascia is because of the cumulative and interactive effects of several genes. Additionally, pigmentation of abdominal fat has a high correlation with accumulation of melanin in the skin of the shanks. Although melanization of the skin and abdominal fascia is not harmful to people, it may cause severe economic losses to the producer.}, number={2}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Pizarro, Manuel}, year={2006}, month={Jun}, pages={309–311} }
 @article{cortes_tiwary_puschner_crespo_chin_bland_shivaprasad_2006, title={Vitamin a Deficiency in Turkey Poults}, volume={18}, ISSN={1040-6387 1943-4936}, url={http://dx.doi.org/10.1177/104063870601800514}, DOI={10.1177/104063870601800514}, abstractNote={Vitamin A deficiency was diagnosed in a commercial flock of 13,000 4–6-week-old turkey poults in the summer of 2004. The birds were initially submitted for examination because of a 3% increase in the reported daily mortality of the flock. Clinically, affected birds had stunted growth and ruffled feathers, showed signs of incoordination, and were depressed. At necropsy, pale white pseudomembranous to mucoid material was observed on the mucosal surface of the tongue, oral cavity, portions of the esophagus, and the crop of some birds. Histologically, there was squamous metaplasia of the mucosal epithelium of the oral mucosa, esophagus, sinuses, nasal glands, bronchi, proventriculus, and the bursa of Fabricius. Vitamin A was not detected in the feed sample at a detection limit of 0.5 mg/kg. Serum vitamin A concentrations in 7 birds were very low and ranged from 0.05 to 0.1 mg/L. Vitamin A concentrations in livers were extremely low (0.1 mg/kg wet weight, 1/7 poults) or undetectable (<0.1 mg/kg wet weight, 6/7 poults). A diagnosis of vitamin A deficiency was made based on gross and microscopic lesions and vitamin A concentrations in serum, liver, and feed. To the authors' knowledge, this is the first documented case of vitamin A deficiency in poults submitted from a commercial meat turkey producer comparatively depicting the gross and microscopic lesions with those found in other species of birds and mammals.}, number={5}, journal={Journal of Veterinary Diagnostic Investigation}, publisher={SAGE Publications}, author={Cortes, P. L. and Tiwary, A. K. and Puschner, B. and Crespo, R. M. and Chin, R. P. and Bland, M. and Shivaprasad, H. L.}, year={2006}, month={Sep}, pages={489–494} }
 @article{shivaprasad_crespo_puschner_2004, title={Coronary artery rupture in male commercial turkeys}, volume={33}, ISSN={0307-9457 1465-3338}, url={http://dx.doi.org/10.1080/0307945042000195777}, DOI={10.1080/0307945042000195777}, abstractNote={Mortalities of 3% in a 1-week period and 2.5% in a 4-week period occurred in two flocks of 13-week-old to 16-week-old male turkeys, respectively. Eleven of 18 birds submitted to the laboratory for necropsy had large amounts of clotted blood in the pericardial sac and transverse bands of haemorrhage at the base of the left heart. Three other birds had clotted blood in the abdominal cavity due to rupture of the aorta. Histopathology of the hearts with haemorrhage at the base of the left heart revealed medial degeneration, necrosis and rupture of the coronary arteries. Special stains revealed decrease in elastic fibres and increase in fibrous connective tissue in the coronary arteries. Fourteen of 16 birds had a low copper concentration (<5 mg/kg wet weight) in the liver; the zinc concentration was high in one bird. Levels of heavy metals including copper and selenium in the feed were within normal ranges for poultry. No mycotoxins were detected in the feed. Tests for bacterial and viral pathogens showed no significant findings. The average weight of these turkeys at market at 16 weeks was 12.5 kg, which was considered 1.4 to 2.3 kg higher than normal. It is well known that male turkeys are prone to hypertensive angiopathy. Therefore, it is probable that higher body weights in the turkeys in conjunction with the hypertensive angiopathy and low levels of copper may have predisposed the birds for coronary artery rupture. Genetic diseases such as connective tissue disorders of the elastin and/or collagen were also considered as possible causes.}, number={2}, journal={Avian Pathology}, publisher={Informa UK Limited}, author={Shivaprasad, H. L. and Crespo, Rocio and Puschner, Birgit}, year={2004}, month={Apr}, pages={226–232} }
 @article{crespo_chin_2004, title={Effect of Feeding Green Onions (Allium Ascalonicum) to White Chinese Geese (Threskiornis Spinicollis)}, volume={16}, ISSN={1040-6387 1943-4936}, url={http://dx.doi.org/10.1177/104063870401600411}, DOI={10.1177/104063870401600411}, abstractNote={Sudden increase in mortality was observed in 2 different flocks of mature breeder geese fed green onions. At necropsy, birds had pale epicardium with random petechiation, sanguinous fluid accumulation in the pericardial sac, and mild swelling of the liver and spleen. Histologically, there was accumulation of hemosiderin in hepatocytes, Kupffer cells of the liver, macrophages, and renal tubules. There was also moderate to severe hepatic necrosis, vacuolation of hepatocytes, splenitis, and renal tubular nephrosis. To assess the effects of green onion ingestion, 2 feeding trials were carried out in 3 mature White Chinese geese. In the first trial, onions were thoroughly mixed with pellet maintenance ration. In the second trial, onions were offered in a separate trough from the pelleted diet. During the 21 days of experiments, the red blood cell count and hematocrit decreased, whereas the polychromasia and reticulocyte estimate increased. The blood changes were more marked in birds from the second feeding trial. Gross and histologic changes were similar in both trials. Mild swelling and severe darkening of the liver were the only significant findings at necropsy. Histologically, the liver looked similar to that seen from the field outbreak. The liver contained moderate amounts of hemosiderin in the hepatocytes and Kupffer cells, and had centrolobular necrosis and vacuolation of hepatocytes. This experimental study demonstrated that anemia and liver pathology could be caused by ingestion of onions. Furthermore, Heinz bodies are not a consistent finding in the blood of geese fed onions.}, number={4}, journal={Journal of Veterinary Diagnostic Investigation}, publisher={SAGE Publications}, author={Crespo, Rocio and Chin, R. P.}, year={2004}, month={Jul}, pages={321–325} }
 @article{cortes_chin_bland_crespo_shivaprasad_2004, title={Histomoniasis in the Bursa of Fabricius of Chickens}, volume={48}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/7175-030404r}, DOI={10.1637/7175-030404r}, abstractNote={Histomoniasis was diagnosed in a flock of 6-wk-old commercial chickens. Clinical signs included depression, stilted gait, inappetence, and a slight increase in mortality. At necropsy, there were pale-yellow to dark-gray circular and depressed necrotic lesions in the liver. The ceca were enlarged and impacted with caseous cores. Cecal worms were not observed either at necropsy or on histopathology. Histomonads were demonstrated microscopically within the bursa of Fabricius in addition to the liver, ceca, and spleen. This is the first report of the presence of histomonads in the bursa of Fabricius in commercial chickens.}, number={3}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Cortes, Portia L. and Chin, R. P. and Bland, Mark C. and Crespo, Rocio and Shivaprasad, H. L.}, year={2004}, month={Sep}, pages={711–715} }
 @article{crespo_jeffrey_chin_sentíes-cué_shivaprasad_2004, title={Phenotypic and Genotypic Characterization of Salmonella arizonae from an Integrated Turkey Operation}, volume={48}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/7116}, DOI={10.1637/7116}, abstractNote={Fifty cases submitted between 2000 and 2002 were selected for retrospective analysis to evaluate possible relationships between Salmonella arizonae isolated from breeder flocks, hatching eggs, and meat bird flocks belonging to a single turkey integrator. In all the meat bird cases selected for this study, arizonosis was the primary diagnosis. In birds under 1 month of age, clinical signs and pathologic changes were observed in older birds. The Salmonella arizonae isolates were analyzed by antibiotic resistance pattern and serotype and genotyped by pulsed-field gel electrophoresis (PFGE). Serotyping and PFGE yielded similar results, but the antibiotic resistance patterns did not correspond to either serotyping or PFGE typing. The presence of common pulsed-field patterns in breeder flocks, eggs, and meat bird flocks suggested that S. arizonae was being transmitted vertically from the breeder flock.}, number={2}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, R. and Jeffrey, J. S. and Chin, R. P. and Sentíes-Cué, G. and Shivaprasad, H. L.}, year={2004}, month={Apr}, pages={344–350} }
 @article{sentíes-cué_crespo_chin_2003, title={Focal Transmural Necrotic Tracheitis in Commerical Meat Turkeys}, volume={47}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/0005-2086(2003)047[0234:ftntic]2.0.co;2}, DOI={10.1637/0005-2086(2003)047[0234:ftntic]2.0.co;2}, abstractNote={This report describes an unusual presentation of severe focal necrotic tracheitis in a flock of 8-wk-old commercial turkeys. The flock was kept on a range that is located near a cotton field. The cotton field had been chemically defoliated 2 wk before the birds were submitted for necropsy. At necropsy, most of the birds had a 1-cm, yellow-white constricture in the upper third of the trachea at which the lumen was partially occluded by necrotic tissue. Microscopically, there was severe, transmural necrosis with an accumulation of inflammatory exudate in the tracheal lumen and numerous bacteria within the necrotic debris, mucosa, and lamina propria. Mixed bacteria were isolated from the trachea. No viruses were detected. Neither abnormal heavy metal concentrations in the liver nor paraquat in the respiratory tract were detected. The exact cause of this severe, necrotic tracheitis was not determined. Based on the clinical history and laboratory findings, it was concluded that a combination of a toxic irritant, possibly an aerosolized cotton defoliant, and bacterial infections were likely the cause of this lesion.}, number={1}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Sentíes-Cué, Gabriel and Crespo, Rocio and Chin, R. P.}, year={2003}, month={Jan}, pages={234–239} }
 @inbook{crespo_shivaprasad_2003, place={Ames, Iowa. Pages}, edition={11th}, title={Miscellaneous diseases}, booktitle={Diseases of Poultry}, publisher={Iowa State Press}, author={Crespo, R. and Shivaprasad, H.L.}, editor={Saif, Y.M.Editor}, year={2003}, pages={1055–1102} }
 @article{crespo_ghazikhanian_hall_2002, title={Avulsion of the Common Retinaculum in Meat Turkeys}, volume={46}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/0005-2086(2002)046[0245:aotcri]2.0.co;2}, DOI={10.1637/0005-2086(2002)046[0245:aotcri]2.0.co;2}, abstractNote={An increase in leg condemnations was experienced in several commercial meat flocks of male and female turkeys. Affected legs had hematomas around and above the tibiotarsus-tarsometatarsus (hock) joint. Avulsion of the common retinaculum from the external condyle was observed when the skin and muscular fascia were removed. A farm investigation was performed and similar changes were observed in turkeys between 10 and 19 wk of age. Interestingly, birds with avulsion of this fibrinous bridge were not lame. Body weights were normal, no infectious agent was detected, and mineral contents of bones and tendons were within normal limits. Avulsion of the retinaculum might not have been diagnosed in the past because the birds are not lame and the lesion is tightly covered by the skin and muscular fascia.}, number={1}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Crespo, Rocio and Ghazikhanian, G. Yan and Hall, Cheryl I.}, year={2002}, month={Jan}, pages={245–248} }
 @article{crespo_woolcock_fadly_hall_shivaprasad_2002, title={Characterization of T-cell lymphomas associated with an outbreak of reticuloendotheliosis in turkeys}, volume={31}, ISSN={0307-9457 1465-3338}, url={http://dx.doi.org/10.1080/03079450220141624}, DOI={10.1080/03079450220141624}, abstractNote={Increased mortality and decreased egg production associated with disseminated lymphoma were observed in a turkey breeding flock for more than 20 weeks. A few unrelated meat turkey flocks, from the same integrator, experienced increased condemnation due to neoplasia in a few organs. Lymphoma was characterized by a uniform population of large lymphocytes with large vesicular nuclei containing one or two nucleoli and with little, faintly staining, basophilic cytoplasm. Neoplastic cells replaced normal tissue and were consistent with lesions seen with reticuloendotheliosis virus (REV) infection. Immunoperoxidase and fluorescent antibody staining characterized the neoplastic cells as CD3+, CD4+ and CD8- lymphocytes. Infection with REV was confirmed by virus isolation, polymerase chain reaction, serology and indirect fluorescent antibody. Poults hatched from these breeders tested positive for REV antibodies at hatch, but the performance of these flocks was normal and lymphoma was not observed. The origin of REV infection in this outbreak could not be determined. This is the first documented report of T-cell lymphomas associated with REV in commercial flocks. Furthermore, this is the first time that lymphomas have been characterized as T helper cells (CD3+ CD4+ and CD8-) in an outbreak of REV in turkeys.}, number={4}, journal={Avian Pathology}, publisher={Informa UK Limited}, author={Crespo, Rocio and Woolcock, Peter R. and Fadly, Aly M. and Hall, Cheryl and Shivaprasad, H. L.}, year={2002}, month={Aug}, pages={355–361} }
 @article{crespo_stover_shivaprasad_chin_2002, title={Microstructure and mineral content of femora in male turkeys with and without fractures}, volume={81}, ISSN={0032-5791 1525-3171}, url={http://dx.doi.org/10.1093/ps/81.8.1184}, DOI={10.1093/ps/81.8.1184}, abstractNote={Microscopic and radiographic observations, as well as ash, calcium, phosphorus, copper, manganese, and zinc concentrations, were evaluated from femora of 32- to 35-wk-old male turkeys from two different farms (A and B). Turkeys from Farm A were divided into birds with femoral fracture (AF) and without femoral fracture (ANF). Turkeys from Farm B did not have femoral fractures (BNF). In the mid-diaphyseal cortex of turkeys without femoral fractures, collagen fibers were evenly distributed parallel to the transverse plane of bone surface. In contrast, collagen fibers were disorganized and the cortex was osteoporotic in turkeys with femoral fractures. Each turkey with femoral fractures also had callus on the mediocaudal region of the femoral middiaphysis. The periosteal callus was interrupted at the insertion of the puboischiofemoralis muscle. Muscle attachment to the bone might have interfered with the formation of periosteal callus. The concentration of calcium was lower in the cortex of turkeys in group AF compared to turkeys in groups ANF and BNF. The focal nature of the callus, along with the low levels of calcium, is indicative of a local repair response with alteration in cortical structure and altered concentrations of minerals in the cortex. These changes in the bone and the routine handling of the birds might have predisposed the turkeys to complete fractures of the femur.}, number={8}, journal={Poultry Science}, publisher={Oxford University Press (OUP)}, author={Crespo, R. and Stover, S. and Shivaprasad, H. and Chin, R.}, year={2002}, month={Aug}, pages={1184–1190} }
 @article{shivaprasad_crespo_puschner_lynch_wright_2002, title={Myopathy in brown pelicans (Pelicanus occidentalis) associated with rancid feed}, volume={150}, ISSN={0042-4900 2042-7670}, url={http://dx.doi.org/10.1136/vr.150.10.307}, DOI={10.1136/vr.150.10.307}, abstractNote={Three adult brown pelicans (Pelicanus occidentalis) were observed to be weak, anorexic and unresponsive to antibiotics, anti-inflammatory drugs, vitamins including vitamin E, and steroids. Blood chemistry revealed high activities of aspartate aminotransferase, creatinine kinase and lactate dehydrogenase. Radiographs of the birds' leg muscles revealed multiple opacities suggestive of calcification; the gross lesions included white streaks in the leg, wing, and heart muscles, and the microscopical lesions consisted of various degrees of degeneration and necrosis characterised by eosinophilia, variations in fibre size, loss of striations, myolysis, mineralisation, and proliferation of mononuclear cells in the skeletal muscles and the myocardium. The levels of heavy metals, selenium and vitamin E in the birds' livers were not abnormal. The level of peroxide in their diet of capelin fish was high, 69 meq/kg, (normal <20 meq/kg) consistent with rancid feed, and the level of vitamin E was very low, 0.5 iu/kg (normal 20 to 30 iu/kg). It was concluded that the myopathy was probably caused by vitamin E deficiency due to feeding the pelicans a rancid diet.}, number={10}, journal={Veterinary Record}, publisher={BMJ}, author={Shivaprasad, H. L. and Crespo, R. and Puschner, B. and Lynch, S. and Wright, L.}, year={2002}, month={Mar}, pages={307–311} }
 @article{crespo_walker_nordhausen_sawyer_manalac_2001, title={Salpingitis in Pekin Ducks Associated with Concurrent Infection with Tetratrichomonas sp. and Escherichia Coli}, volume={13}, ISSN={1040-6387 1943-4936}, url={http://dx.doi.org/10.1177/104063870101300309}, DOI={10.1177/104063870101300309}, abstractNote={Increased mortality (1.5% per week) and low egg production (5–10% lower than normal) were observed in a flock of domestic breeding Pekin ducks ( Anas platyrhynchos). At necropsy, salpingitis and peritonitis were the most significant findings. Histologically, there was accumulation of necrotic debris in the lumen of the oviduct. Numerous bacteria and trichomonads were observed histologically in the lumen of the vagina and occasionally in the shell gland. Escherichia coli and a trichomonad were isolated from the oviduct. The trichomonads were oval (6–8 μm long, 4.5–6 μm wide) and had 4 anterior flagella and an undulating membrane extending over the entire length of the body, finishing in a long posterior flagellum. Morphology was consistent with trichomonads of the genus Tetratrichomonas. Comparative sequence analysis of the 5.8S ribosomal RNA gene and the flanking internal transcribed space regions of the trichomonad isolate did not closely match with available sequences of the same region of other trichomonadid protozoa.}, number={3}, journal={Journal of Veterinary Diagnostic Investigation}, publisher={SAGE Publications}, author={Crespo, Rocio and Walker, Richard L. and Nordhausen, Robert and Sawyer, Sherilyn J. and Manalac, Rosa B.}, year={2001}, month={May}, pages={240–245} }
 @article{crespo_stover_taylor_chin_shivaprasad_2000, title={Morphometric and mechanical properties of femora in young adult male turkeys with and without femoral fractures}, volume={79}, ISSN={0032-5791 1525-3171}, url={http://dx.doi.org/10.1093/ps/79.4.602}, DOI={10.1093/ps/79.4.602}, abstractNote={Morphologic and torsional mechanical properties of femora were evaluated in three groups of turkeys to determine whether turkeys that incurred femoral fracture have different radiographic, morphologic, and torsional mechanical properties than do turkeys without femoral fracture, and if body weight was a factor differentiating affected and nonaffected turkeys. Nine turkeys with unilateral femoral fractures and nine turkeys without fractures from Farm A were compared with a group of nine age and genetically matched turkeys from Farm B. Turkeys from Farm A were 10 to 25% heavier (26.2+/-0.9 kg) and turkeys from Farm B were 10% lighter (18.2+/-0.9 kg) than expected breed standards. Femoral length, cortical thickness, medullary diameter, and diaphyseal curvature were measured from craniocaudal and lateromedial radiographs. One intact femur from each of five turkeys with a contralateral femoral fracture (Farm A), nine unaffected turkeys from Farm A, and nine turkeys from Farm B were subjected to failure in a torsion test. Geometric and mechanical results were compared. Turkeys from Farm A had a thicker cortex and a smaller medullary diameter than turkeys from Farm B. Turkeys from Farm A had significantly lower torsional stiffness and failure torque values compared with turkeys from Farm B, when differences in body weight were accounted for (analysis of covariance, P < 0.05). Mechanical failure torque calculated from geometric values suggests that organic or inorganic material arrangement and composition may be responsible, in part, for differences between groups. Femoral fractures may be associated with insufficient skeletal adaptation to heavy body weight.}, number={4}, journal={Poultry Science}, publisher={Oxford University Press (OUP)}, author={Crespo, R. and Stover, S. M. and Taylor, K. T. and Chin, R. P. and Shivaprasad, H. L.}, year={2000}, month={Apr}, pages={602–608} }
 @article{crespo_shivaprasad_woolcock_chin_davidson-york_tarbell_1999, title={Exotic Newcastle Disease in a Game Chicken Flock}, volume={43}, ISSN={0005-2086}, url={http://dx.doi.org/10.2307/1592629}, DOI={10.2307/1592629}, abstractNote={A sudden increase in mortality, preceded by a short history of respiratory signs and diarrhea, occurred in a backyard flock of 48 game chickens in the Central Valley of California. Necropsy findings included severe generalized linear hemorrhages and/or ulcers in the digestive tract, larynx, and trachea. Histology revealed severe multifocal hemorrhages and necrosis in the mucosa of the respiratory and digestive tracts, vasculitis, and necrosis of lymphoid tissue. The birds were serologically negative to Newcastle disease virus; this was consistent with an acute infection. The avian paramyxovirus type 1 isolated was characterized as velogenic viscerotropic Newcastle disease virus. A thorough epidemiologic investigation was carried out, and no other premises were found to have birds with clinical signs or evidence of exposure. The entire outbreak was limited to the original backyard flock and resolved within 14 days of the onset of clinical signs.}, number={2}, journal={Avian Diseases}, publisher={JSTOR}, author={Crespo, Rocio and Shivaprasad, H. L. and Woolcock, Peter R. and Chin, R. P. and Davidson-York, Dorothy and Tarbell, Robert}, year={1999}, month={Apr}, pages={349} }
 @article{crespo_stover_droual_chin_shivaprasad_1999, title={Femoral Fractures in a Young Male Turkey Breeder Flock}, volume={43}, ISSN={0005-2086}, url={http://dx.doi.org/10.2307/1592775}, DOI={10.2307/1592775}, abstractNote={Twenty-two 32-to-35-wk-old male turkeys from a commercial breeding flock were presented to the California Veterinary Diagnostic Laboratory System, Fresno Branch, with a clinical complaint of lameness and increased mortality. Necropsy findings included a unilateral, closed oblique fracture involving the femur in 12 birds. Ten complete femoral fractures had periosteal new bone adjacent to and bridging the fracture. Periosteal callus formation, in this case, suggested that preexisting lesions preceded complete fracture of the femur. Factors such as selection for heavy body weight, lack of exercise, and handling might have contributed to the development and promotion of complete fractures.}, number={1}, journal={Avian Diseases}, publisher={JSTOR}, author={Crespo, R. and Stover, S. M. and Droual, R. and Chin, R. P. and Shivaprasad, H. L.}, year={1999}, month={Jan}, pages={150–154} }
 @article{crespo_yamashiro_hunter_1998, title={Development of the Thoracic Air Sacs of Turkeys with Age and Rearing Conditions}, volume={42}, ISSN={0005-2086}, url={http://dx.doi.org/10.2307/1592574}, DOI={10.2307/1592574}, abstractNote={Cytology and structure of the thoracic air sac of turkeys were investigated at four different ages (26-day embryo, 1 day, 2 wk, and 10 wk old) and two rearing conditions (isolation and commercial). Cytology was performed by guided fiberoptic endoscopy on the left thoracic air sac of each bird. The right thoracic air sac was sampled for light and electron microscopy. Heterophils were the most common nonepithelial cell found in air sac fluid. followed by macrophages and lymphocytes. Macrophages were most abundant in 1-day-old turkeys and turkeys raised in commercial conditions. The epithelium of the air sac consisted of squamous and cuboidal cells, with a few ciliated columnar and nonciliated columnar cells. Cuboidal cells had similar characteristics to type II pneumocytes. The mucociliary system was organized in tracts extended from the ostium to the posterior parts of the air sac. The number of ciliated tracts decreased with age, and the air sacs of commercial turkeys had a larger proportion of ciliated epithelium than did those of isolation birds. The epithelium may protect against disease by a structured mucociliary transport system, the production of surfactant, and phagocytosis of foreign particles. Differences in cytology and structure may reflect the maturation of the immune system and/or response to environment.}, number={1}, journal={Avian Diseases}, publisher={JSTOR}, author={Crespo, Rocio and Yamashiro, Shigeto and Hunter, D. Bruce}, year={1998}, month={Jan}, pages={35} }
 @article{crespo_taylor_hunter_1998, title={Endoscopic Gross Anatomy Findings of the Thoracic Air Sac of the Turkey}, volume={42}, ISSN={0005-2086}, url={http://dx.doi.org/10.2307/1592592}, DOI={10.2307/1592592}, abstractNote={The gross anatomy of the cranial thoracic air sacs was studied in the live turkey with a fiber-optic endoscope fitted with a video system. Thirty-five out of 39 (89.7%) of the turkeys had paired single thoracic air sacs with two ostia. The other 10.3% of the turkeys had paired cranial and caudal thoracic air sacs, each with a single ostium. The air flow pattern through the common thoracic air sac with two ostia is unknown. Furthermore, 42.3% of the turkeys with a single thoracic air sac had an invagination arising from the floor of the air sac that partially divided the single thoracic air sac creating a blind-ended sac. The blind sac formed by the invagination may trap small inhaled particulate matter.}, number={1}, journal={Avian Diseases}, publisher={JSTOR}, author={Crespo, Rocio and Taylor, Michael and Hunter, D. Bruce}, year={1998}, month={Jan}, pages={179} }
 @article{crespo_stirtzinger_hunter_1998, title={Evaluation of Different Procedures for Processing Avian Air Sac Lavage Fluid}, volume={42}, ISSN={0005-2086}, url={http://dx.doi.org/10.2307/1592572}, DOI={10.2307/1592572}, abstractNote={Air sac lavage has become a routine diagnostic tool used in pet birds; however, cytologic techniques for collection and handling of avian cells have not been reported. In this study, directed endoscopy was used to obtain the air sac washes. Different factors were compared that might affect final preservation of cell morphology, such as centrifugation speed, anticoagulant, storage temperature, time to processing, addition of glutaraldehyde to the sample, and addition of protein. The goal was to find the processing technique best suited for the evaluation of cells from air sac washes. The use of an anticoagulant did not influence cell quality. Optimal cell morphology was achieved when the sample was centrifuged at a speed of 1000 rpm (89.4 X g) and when prepared in less than an hour from the time of collection. Low temperature (5 C) tended to preserve cell quality better. The addition of protein (fetal bovine serum) helped to preserve cell quality and was of value if the sample storage time was greater than 30 min. The addition of glutaraldehyde resulted in a significant reduction in cell quality.}, number={1}, journal={Avian Diseases}, publisher={JSTOR}, author={Crespo, Rocio and Stirtzinger, Tantiana and Hunter, D. Bruce}, year={1998}, month={Jan}, pages={20} }
 @article{crespo_shivaprasad_droual_chin_woolcock_carpenter_1998, title={Inclusion Body Tracheitis Associated with Avian Adenovirus in Turkeys}, volume={42}, ISSN={0005-2086}, url={http://dx.doi.org/10.2307/1592687}, DOI={10.2307/1592687}, abstractNote={Nine turkey flocks with basophilic intranuclear inclusion bodies, suggestive of adenovirus, within the epithelial cells of the tracheal mucosa were studied. Respiratory signs and increased mortality occurred in turkeys between 6 and 10 wk of age from nine commercial turkey meat flocks in central California. Necropsy findings included tracheitis and occasional mild sinusitis. Histopathology of the tracheas revealed epithelial deciliation, squamous metaplasia, large basophilic intranuclear inclusion bodies within epithelial cells, and lymphoplasmatic inflammation in the mucosa. Electron microscopy of the mucosa revealed hexagonal viral particles, approximately 73 nm in diameter, consistent with adenovirus within the nuclei of epithelial cells. All tracheal sections were negative for adenovirus group II by specific immunoperoxidase staining. Adenovirus group I was isolated from the trachea. In addition, Bordetella avium, Ornithobacterium rhinotracheale, and Klebsiella pneumoniae were isolated from the tracheas of three, three, and two flocks, respectively. Statistically greater total mortality and a smaller percentage of marketed turkeys were observed in the submitted flocks than in randomly selected flocks. No significant difference was observed between the two turkey groups in market weight, feed conversion, or percentage of grade "A" turkeys.}, number={3}, journal={Avian Diseases}, publisher={JSTOR}, author={Crespo, Rocio and Shivaprasad, H. L. and Droual, Robert and Chin, Richard P. and Woolcock, Peter R. and Carpenter, Tim E.}, year={1998}, month={Jul}, pages={589–596} }