@article{borst_mclamb_suyemoto_chen_levy_sarsour_cordova_barnes_oviedo-rondón_2019, title={Coinfection with Eimeria spp. decreases bacteremia and spinal lesions caused by pathogenic Enterococcus cecorum}, volume={250}, ISSN={0377-8401}, url={http://dx.doi.org/10.1016/J.ANIFEEDSCI.2018.09.014}, DOI={10.1016/J.ANIFEEDSCI.2018.09.014}, abstractNote={Pathogenic strains of Enterococcus cecorum (EC) escape the gut niche to infect the spine of broilers at the free thoracic vertebra (FTV) causing the disease enterococcal spondylitis or ‘kinky-back’. Intestinal barrier damage caused by coinfection with Eimeria spp. has been suggested to play a role in potentiating EC bacteremia and FTV lesion development. To test this hypothesis, 1440 broilers were experimentally infected with EC only, EC and a coinfection of E. acervulina, E. maxima and E. tenella (EC:Cocci), and a saline only control (Sham). Birds were grown for 35 days, spleen cultures, histologic lesions in the FTV and live performance parameters were compared among groups. Coccidian coinfection significantly decreased the prevalence of EC bacteremia and histologic lesions in the FTV. Histologic evaluation of the ceca revealed significantly increased cecal mucosal height and mean inflammatory scores in the EC:Cocci group compared to EC only and sham inoculated controls. These findings indicate that the decrease in pathogenic EC bacteremia observed with coccidia coinfection may be due to increased intestinal epithelial turnover or increased immune surveillance of the intestine. In both infection groups, body weights, body weight gain and feed intake were significantly decreased and feed conversion ratios were significantly increased. These undesirable alterations in live performance parameters were exacerbated by nicarbazin treatment but not zoalene or bacitracin treatment. Further work is needed to determine the mechanism for the observed benefit of coccidian coinfection in decreasing bacteremia and FTV lesions due to pathogenic EC.}, journal={Animal Feed Science and Technology}, publisher={Elsevier BV}, author={Borst, L.B. and McLamb, K.A. and Suyemoto, M.M. and Chen, L.R. and Levy, M.G. and Sarsour, A.H. and Cordova, H.A. and Barnes, H.J. and Oviedo-Rondón, E.O.}, year={2019}, month={Apr}, pages={59–68} }
 @article{chen_suyemoto_sarsour_cordova_oviedo-rondon_wineland_barnes_borst_2019, title={Temporal characterization of wooden breast myopathy ("woody breast") severity and correlation with growth rate and lymphocytic phlebitis in three commercial broiler strains and a random-bred broiler strain}, volume={48}, ISSN={["1465-3338"]}, DOI={10.1080/03079457.2019.1598541}, abstractNote={ABSTRACT Wooden breast myopathy (WBM), or “woody breast” or “wooden breast” affects modern, rapidly growing, high breast-yield broiler chickens. Decreased meat quality due to undesirable organoleptic properties and condemnation of affected breast meat cause economic losses. The pathogenesis of WBM remains unknown. In this study, WBM lesion development was determined in three modern broiler strains and Athens Canadian Random Bred (ACRB) broilers, a 1950s unselected broiler chicken. Correlations between WBM severity and incubation temperature profile, sex, strain, body weight, and lymphocytic phlebitis were also determined. At 2, 4, 6, and 8 weeks of age, samples of breast muscle from 10 male and 10 female birds from each strain, incubated under optimal or low-early, high-late temperatures, were scored histologically for severity of WBM and lymphocytic phlebitis. WBM lesions, identified as early as 2 weeks, became progressively more severe with age and growth in the three commercial broiler strains. WBM severity was significantly correlated with lymphocytic phlebitis and body weight. Lymphocytic phlebitis and minimal WBM were present in the ACRB broilers at all samplings, but did not progress in severity over time. There were no significant differences in severity of WBM among the commercial broiler strains, between sexes, or between incubation temperature profiles. The positive correlation between WBM severity and lymphocytic phlebitis indicates vascular injury is likely an important factor in the pathogenesis. Mild muscle lesions in ACRB birds without overt clinical signs indicate subclinical muscle disease may have been present in broilers prior to the description of WBM.}, number={4}, journal={AVIAN PATHOLOGY}, author={Chen, Laura R. and Suyemoto, M. Mitsu and Sarsour, Albarra H. and Cordova, H. Alejandro and Oviedo-Rondon, Edgar O. and Wineland, Michael and Barnes, H. John and Borst, Luke B.}, year={2019}, month={Jul}, pages={319–328} }
 @article{borst_suyemoto_chen_barnes_2019, title={Vaccination of breeder hens with a polyvalent killed vaccine for pathogenic Enterococcus cecorum does not protect offspring from enterococcal spondylitis}, volume={48}, ISSN={["1465-3338"]}, url={https://doi.org/10.1080/03079457.2018.1536819}, DOI={10.1080/03079457.2018.1536819}, abstractNote={ABSTRACT Pathogenic strains of Enterococcus cecorum cause symmetrical paralysis in broilers due to infection of the free thoracic vertebra. The disease caused by pathogenic E. cecorum, known as enterococcal spondylitis or “kinky-back” continues to be responsible for significant losses to the broiler industry worldwide. In outbreaks of pathogenic E. cecorum, gut colonization and sepsis occur in the first three weeks-of-life. Since maternal antibodies are present during this period, we postulated that vaccination of breeders with a polyvalent killed vaccine would protect chicks from challenge. To test this hypothesis, representative isolates from seven genotype groups of pathogenic E. cecorum circulating in the US were chosen to produce adjuvanted killed vaccines (bacterins) and given to broiler-breeder hens. No single strain produced high titres of antibodies to all other strains; however, the combination of serologic reactivity of pathogenic isolates (designated SA3 and SA7) was sufficient to react with all genotypes. Vaccination of commercial broiler-breeder hens with a bacterin composed of SA3 and SA7 did not have any adverse effects. Vaccinated hens developed E. cecorum specific antibodies; however, no significant difference in survival was observed in infected embryos from hens in vaccine or adjuvant only groups. Chicks from vaccinated hens also failed to resist homologous or heterologous challenge during experimental infection. In a macrophage killing assay, pathogenic E. cecorum were found to evade opsinophagocytosis with elicited antibodies. These data suggest that pathogenic strains of E. cecorum possess virulence mechanisms that confound antibody-mediated opsinophagocytosis, complicating vaccine development for this pathogen of broilers.}, number={1}, journal={AVIAN PATHOLOGY}, author={Borst, Luke B. and Suyemoto, M. Mitsu and Chen, Laura R. and Barnes, H. John}, year={2019}, month={Jan}, pages={17–24} }
 @article{gall_suyemoto_sather_sharpton_barnes_borst_2019, title={Wooden Breast in Commercial Broilers Associated with Mortality, Dorsal Recumbency, and Pulmonary Disease}, volume={63}, ISSN={["1938-4351"]}, DOI={10.1637/11995-111218-Case.1}, abstractNote={SUMMARY. Occurrence of mortality, wooden breast, and pulmonary disease in broiler chickens during the last 16 days of production in a teaching flock of 4000 commercial broilers was determined. A new syndrome was identified, in which broilers fell over for an unknown reason and were unable to right themselves (dorsal recumbency). Birds affected by dorsal recumbency were alert and responsive and showed no clinical signs except for occasional mild to moderate dyspnea. When turned over, they resumed normal behavior. Mortality (14 culls; 49 dead) during the last 16 days of production accounted for 1.6% of the flock and 36% of total mortality. Among these, 71% were heavy males, 70% had wooden breast, and 71% had pulmonary congestion and edema. Gross lesions of concurrent wooden breast and pulmonary disease occurred in 68% of the mortality, including 21 of 22 dead birds found on their backs. These findings indicate that wooden breast is associated with mortality prior to processing as a result of pulmonary disease in heavy male broilers. When birds with wooden breast fall onto their backs for unknown reason(s), they are unable to right themselves. If not found and turned over, they may not survive. Based on these findings, wooden breast is likely greater than just a problem with meat quality and should be considered an animal well-being issue.}, number={3}, journal={AVIAN DISEASES}, author={Gall, Sesny and Suyemoto, M. Mitsu and Sather, Hannah M. L. and Sharpton, A. Richard and Barnes, H. John and Borst, Luke B.}, year={2019}, month={Sep}, pages={514–519} }
 @book{abdul-aziz_barnes_2018, title={Gross pathology of avian diseases: Text and atlas}, publisher={Jacksonville, Fla.: American Association of Avian Pathologists}, author={Abdul-Aziz, T. and Barnes, H.J.}, year={2018} }
 @article{suyemoto_barnes_borst_2017, title={Culture methods impact recovery of antibiotic-resistant Enterococci including Enterococcus cecorum from pre- and postharvest chicken}, volume={64}, ISSN={["1472-765X"]}, DOI={10.1111/lam.12705}, abstractNote={Pathogenic strains of Enterococcus cecorum (EC) expressing multidrug resistance have emerged. In National Antimicrobial Resistance Monitoring System (NARMS) data, EC is rarely recovered from chickens. Two NARMS methodologies (FDA and USDA) were compared with standard culture (SC) techniques for recovery of EC. NARMS methods failed to detect EC in 58 caecal samples, 20 chicken breast or six whole broiler samples. EC was recovered from 1 of 38 (2·6%) and 2 of 38 (5·2%) preharvest spinal lesions (USDA and FDA method, respectively). In contrast, using the SC method, EC was recovered from 44 of 53 (83%) caecal samples, all 38 (100%) spinal lesions, 14 of 20 (70%) chicken breast samples, and all three spinal lesions identified in whole carcasses. Compared with other Enterococcus spp., EC isolates had a higher prevalence of resistance to macrolides. The NARMS methods significantly affected recovery of enterococcal species other than EC. When the postharvest FDA method was applied to preharvest caecal samples, isolates of Enterococcus faecium were preferentially recovered. All 11 E. faecium isolates were multidrug resistant, including resistance to penicillin, daptomycin and linezolid. These findings confirm that current methodologies may not accurately identify the amount and range of antimicrobial resistance of enterococci from chicken sources.}, number={3}, journal={LETTERS IN APPLIED MICROBIOLOGY}, author={Suyemoto, M. M. and Barnes, H. J. and Borst, L. B.}, year={2017}, month={Mar}, pages={210–216} }
 @article{genger_mizukami_martin_applegate_barnes_giger_2017, title={Mucopolysaccharidosis IIIB (Sanfilippo syndrome B) in a commercial emu (Dromaius novaehollandiae) flock}, volume={47}, ISSN={0307-9457 1465-3338}, url={http://dx.doi.org/10.1080/03079457.2017.1380293}, DOI={10.1080/03079457.2017.1380293}, abstractNote={ABSTRACT Clinicopathological diagnosis of mucopolysaccharidosis type IIIB (MPS IIIB; Sanfilippo syndrome B), an inherited autosomal recessive lysosomal storage disease, as a cause of losses in a commercial emu flock and screening breeders using a mutation-specific DNA test are described. Between 2012 and 2015, ∼5–10 juvenile emus from a few weeks to several months of age developed progressive neurological signs and died while others in the flock remained healthy. Necropsy of two affected siblings revealed multiple sites of haemorrhage, cytoplasmic periodic acid-Schiff and Luxol fast blue-positive inclusions in neurons, and aggregates of foamy macrophages in visceral organs. Affected emus were homozygous for the two-base deletion in the α-N-acetylglucosaminidase gene that causes MPS IIIB in emus. Mutation-specific DNA tests for MPS IIIB in emus were developed. Screening blood samples from 78 breeding emus revealed 14 (18%; 9 males, 4 females, and 1 unknown gender) carriers; an overall 0.09 mutant α-N-acetylglucosaminidase allele frequency. A “test and cull male carriers” programme, in which carrier males are culled but carrier females are retained, was proposed to avoid breeding affected emus together, ultimately eliminating the disease from future broods, and preserving the gene pool with as much breeding stock as possible. Molecular genetic diagnostic tests are simple, precise, and permit screening of all breeders for the mutant allele in any flock and can be used to eliminate MPS IIIB-related emu losses through informed breeding.}, number={1}, journal={Avian Pathology}, publisher={Informa UK Limited}, author={Genger, Seiche C. and Mizukami, Keijiro and Martin, Michael P. and Applegate, Jeffrey R., Jr and Barnes, H. John and Giger, Urs}, year={2017}, month={Oct}, pages={100–107} }
 @article{chen_suyemoto_sarsour_cordova_oviedo-rondón_barnes_borst_2017, title={Prevalence and severity of osteochondrosis of the free thoracic vertebra in three modern broiler strains and the Athens Canadian Random Bred control broiler}, volume={47}, ISSN={0307-9457 1465-3338}, url={http://dx.doi.org/10.1080/03079457.2017.1388499}, DOI={10.1080/03079457.2017.1388499}, abstractNote={ABSTRACT Osteochondrosis (OCD) results from a disturbance of endochondral ossification in articular cartilage and is an important cause of lameness in several animal species, including chickens. OCD lesions in the free thoracic vertebra (FTV) of chickens are essential to the pathogenesis of pathogenic Enterococcus cecorum. The goal of this study was to determine the prevalence of OCD in the FTV among three modern broiler chicken crosses (strains A/A, A/B, and C/C) and Athens Canadian Random Bred (ACRB) chickens, which served as the control group. The effect of sex, age, strain, body weight, and incubation temperature profile on OCD severity for each group was determined. At 2, 4, 6, and 8 weeks of age, the FTV of 10 male and 10 female birds from each strain exposed to either optimal or low-early, high-late incubation temperature profiles were collected and scored histologically for OCD lesion severity. OCD spectrum lesions were detected in >70% of all strain/sex combinations, including the ACRB controls. No association was observed between mean OCD score and broiler strain, incubation temperature profile, sex, age, or body weight. These findings indicate that OCD of the FTV is common in broiler chickens with similar prevalence observed in broilers with modern genetics and the ACRB broilers which represent 1950s broiler genetics. As the parameters examined did not have a statistical correlation with OCD, additional work is needed to understand factors that contribute to development of OCD in chickens.}, number={2}, journal={Avian Pathology}, publisher={Informa UK Limited}, author={Chen, Laura R. and Suyemoto, M. Mitsu and Sarsour, Albarra H. and Cordova, H. Alejandro and Oviedo-Rondón, Edgar O. and Barnes, H. John and Borst, Luke B.}, year={2017}, month={Nov}, pages={152–160} }
 @article{borst_suyemoto_sarsour_harris_martin_strickland_oviedo_barnes_2016, title={Pathogenesis of Enterococcal Spondylitis Caused by Enterococcus cecorum in Broiler Chickens}, volume={54}, ISSN={0300-9858 1544-2217}, url={http://dx.doi.org/10.1177/0300985816658098}, DOI={10.1177/0300985816658098}, abstractNote={ Enterococcal spondylitis (ES) is a disease of commercial broiler chickens, with a worldwide distribution. Symmetrical hind limb paralysis typical of ES results from infection of the free thoracic vertebra (FTV) by pathogenic strains of Enterococcus cecorum . To determine the pathogenesis of ES, birds with natural and experimental ES were studied over time. In natural disease, case birds (n = 150) from an affected farm and control birds (n = 100) from an unaffected farm were evaluated at weeks 1–6. In control birds, intestinal colonization by E. cecorum began at week 3. In case birds, E. cecorum was detected in intestine and spleen at week 1, followed by infection of the FTV beginning at week 3. E. cecorum isolates recovered from intestine, spleen, and FTV of case birds had matching genotypes, confirming that intestinal colonization with pathogenic strains precedes bacteremia and infection of the FTV. Clinical intestinal disease was not required for E. cecorum bacteremia. In 1- to 3-week-old case birds, pathogenic E. cecorum was observed within osteochondrosis dissecans (OCD) lesions in the FTV. To determine whether OCD of the FTV was a risk factor for ES, 214 birds were orally infected with E. cecorum, and the FTV was evaluated histologically at weeks 1–7. Birds without cartilage clefts of OCD in the FTV did not develop ES; while birds with OCD scores ≥3 were susceptible to lesion development. These findings suggest that intestinal colonization, bacteremia, and OCD of the FTV in early life are crucial to the pathogenesis of ES. }, number={1}, journal={Veterinary Pathology}, publisher={SAGE Publications}, author={Borst, L. B. and Suyemoto, M. M. and Sarsour, A. H. and Harris, M. C. and Martin, M. P. and Strickland, J. D. and Oviedo, E. O. and Barnes, H. J.}, year={2016}, month={Aug}, pages={61–73} }
 @article{wernick_tobias_moeller_barnes_palmieri_shivaprasad_2015, title={Bilateral Malignant Seminomas in Two Unrelated, Aged Trumpeter Hornbills (Bycanistes buccinator)}, volume={29}, ISSN={["1938-2871"]}, DOI={10.1647/2014-022}, abstractNote={Abstract Seminomas occur infrequently in birds. Two cases of bilateral malignant seminomas in unrelated trumpeter hornbills (Bycanistes buccinator) are described. Case 1 was a 22-year-old trumpeter hornbill submitted for necropsy because of sudden death at a zoo in California. Postmortem examination revealed multiple masses within the body cavity, 2 of which replaced both testes. Case 2 was a 19-year-old trumpeter hornbill at a zoo in North Carolina that underwent exploratory surgery for a suspected gastrointestinal obstruction. Both testes were diffusely enlarged, compressing and replacing the adjacent kidneys. In both birds, the masses were composed of discrete, round to polyhedral cells, typical of seminomas. Examination of the ancestry of the hornbills showed they were unrelated to each other, suggesting a potential predisposition for these birds to develop seminomas.}, number={2}, journal={JOURNAL OF AVIAN MEDICINE AND SURGERY}, author={Wernick, Morena B. and Tobias, Jeremy R. and Moeller, Robert B. and Barnes, John and Palmieri, Chiara and Shivaprasad, H. L.}, year={2015}, month={Jun}, pages={125–129} }
 @article{borst_suyemoto_keelara_dunningan_guy_barnes_2014, title={A Chicken Embryo Lethality Assay for Pathogenic Enterococcus cecorum}, volume={58}, ISSN={["1938-4351"]}, DOI={10.1637/10687-101113-reg.1}, abstractNote={SUMMARY Pathogenic strains of Enterococcus cecorum cause outbreaks of arthritis and osteomyelitis in chickens worldwide. Enterococcal spondylitis (ES) is a specific manifestation of E. cecorum-associated disease of broilers and broiler breeders characterized by increased flock mortality, resulting from unresolved infection of the free thoracic vertebra by pathogenic E. cecorum. A study of 22 ES outbreaks in the southeast United States revealed that pathogenic E. cecorum strains isolated from spinal lesions were genetically clonal. Here, we compare the virulence of previously genotyped pathogenic strains (n  =  8) isolated from spinal lesions and nonpathogenic strains (n  =  9) isolated from ceca of unaffected birds in a chicken embryo lethality model. Strains were inoculated into the allantoic cavity of 12-day-old broiler and specific-pathogen-free (SPF) layer embryos; embryo survival was determined by candling eggs daily for 4 days. Significantly decreased survival occurred in both broiler and SPF embryos inoculated with pathogenic genotype strains compared with embryos inoculated with nonpathogenic genotype strains (broiler embryos, 23% vs. 60%; SPF embryos, 9% vs. 61%). Embryos infected with pathogenic strains were unable to control infection and consistently showed gross changes typical of sepsis, including hemorrhage and edema. After 48 hr, similar changes were not observed in embryos infected with nonpathogenic strains. This embryo lethality assay provides a useful tool for understanding the genetic basis of E. cecorum virulence. RESUMEN Ensayo de letalidad en embriones de pollo para cepas de Enterococcus cecorum patogénicas. Las cepas patógenas de Enterococcus cecorum causan brotes de artritis y osteomielitis en pollos a nivel mundial. La espondilitis enterococócica (ES) es una manifestación específica de la enfermedad asociada con E. cecorum en pollos de engorde y en reproductoras pesadas que es caracterizada por alta mortalidad de la parvada, como resultado de la infección no resuelta en la vértebra torácica móvil causada por cepas de E. cecorum patógenas. Un estudio de 22 brotes de espondilitis enterococócica en el sureste de los Estados Unidos reveló que las cepas patógenas de E. cecorum aisladas de lesiones de la médula eran genéticamente provenientes de un clon. En este estudio, se comparó mediante un modelo de letalidad del embrión de pollo, la virulencia de las cepas patógenas previamente genotipificadas (n = 8) aisladas de lesiones de la columna vertebral y cepas no patógenas (n = 9) aisladas del ciego de las aves no afectadas. Las cepas fueron inoculadas en la cavidad alantoidea de embriones de pollo de 12 días de edad, de pollos de engorde y en aves libres de patógenos específicos (SPF); la supervivencia de los embriones se determinó por ovoscopía diariamente por cuatro días. De manera significativa se presentó una disminución en la supervivencia en ambos tipo embriones de pollos de engorde y de aves libres de patógenos específicos inoculados con cepas de genotipo patógeno en comparación con los embriones inoculados con cepas de genotipo no patógeno (embriones de pollos de engorde, 23% contra 60%; y en los embriones libres de patógenos específicos, 9% frente a 61%). Los embriones infectados con cepas patógenas fueron incapaces de controlar la infección y mostraron consistentemente cambios macroscópicos típicos de sepsis, incluyendo hemorragia y edema. Después de 48 horas, no se observaron cambios similares en los embriones infectados con cepas no patógenas. Este ensayo de letalidad del embrión proporciona una herramienta útil para la comprensión de la base genética de la virulencia de E. cecorum.}, number={2}, journal={AVIAN DISEASES}, author={Borst, Luke B. and Suyemoto, M. Mitsu and Keelara, Shivaramu and Dunningan, Sarah E. and Guy, James S. and Barnes, H. John}, year={2014}, month={Jun}, pages={244–248} }
 @article{rodriguez_barnes_anderson_whitaker_berchuck_petitte_lancaster_wenham_turbov_day_et al._2013, title={Evidence of a Chemopreventive Effect of Progestin Unrelated to Ovulation on Reproductive Tract Cancers in the Egg-laying Hen}, volume={6}, ISSN={1940-6207 1940-6215}, url={http://dx.doi.org/10.1158/1940-6207.CAPR-12-0426}, DOI={10.1158/1940-6207.capr-12-0426}, abstractNote={Epidemiologic, laboratory, and animal evidence suggests that progestins and vitamin D may be potent ovarian cancer preventives. Our objectives were to evaluate progestins as reproductive tract cancer chemopreventives in the chicken, determine whether restricted ovulation affected the incidence of reproductive tract tumors, and assess whether vitamin D would confer cancer protection either alone or in addition to progestin. A total of 2,400 two-year-old Single Comb White Leghorns were randomized into six groups (400 each) with hormonal and dietary manipulation for 2 years as follows: (i) no intervention, regular feed/caloric intake, (ii) control, (iii) vitamin D, (iv) the progestin levonorgestrel, (v) vitamin D plus levonorgestrel, and (vi) the progestin Provera (medroxyprogesterone acetate). Groups 2 to 6 were caloric restricted to inhibit ovulation. Our results indicated that caloric restriction decreased egg production by more than 60%, and was associated with a greater than 70% decrease in reproductive tract cancers. Ovulatory events did not differ among the caloric-restricted groups (groups 2–6), except for the group receiving levonorgestrel, which had fewer ovulatory events than controls (P = 0.046). After correcting for egg production, birds receiving progestins had significantly fewer reproductive tract cancers [OR, 0.61; confidence interval (CI), 0.39–0.95; P = 0.03], with similar proportionate reductions in tumors arising in either the ovary or oviduct. Vitamin D did not significantly affect cancer incidence overall, or add to the cancer preventive effect of progestins. This study suggests a protective effect of progestins against ovarian and oviductal cancers. These data support the concept that progestins provide a chemopreventive effect unrelated to ovulation. Cancer Prev Res; 6(12); 1283–92. ©2013 AACR.}, number={12}, journal={Cancer Prevention Research}, publisher={American Association for Cancer Research (AACR)}, author={Rodriguez, G. C. and Barnes, H. J. and Anderson, K. E. and Whitaker, R. S. and Berchuck, A. and Petitte, J. N. and Lancaster, J. M. and Wenham, R. M. and Turbov, J. M. and Day, R. and et al.}, year={2013}, month={Oct}, pages={1283–1292} }
 @article{robbins_suyemoto_lyman_martin_barnes_borst_2012, title={An Outbreak and Source Investigation of Enterococcal Spondylitis in Broilers Caused by Enterococcus cecorum}, volume={56}, ISSN={["0005-2086"]}, DOI={10.1637/10253-052412-case.1}, abstractNote={SUMMARY. Enterococcus cecorum was isolated from spondylitis lesions in broilers from two flocks in North Carolina that were experiencing increased mortality. Affected birds showed paresis and paralysis, clinical signs characteristic of enterococcal spondylitis (ES). Affected birds rested on their hocks and caudal abdomens with legs extended forward and were unable to stand or walk. Necropsy examination of affected birds revealed firm to hard inflammatory masses involving the vertebral bodies at the level of the free thoracic vertebra that bulged dorsally and compressed the spinal cord. When opened, lesions contained pale, tan to yellow caseonecrotic material. Microscopically, necrosis and fibrinoheterophilic spondylitis with intralesional gram-positive bacteria were seen. Heavy growth of E. cecorum recovered from vertebral lesions confirmed the diagnosis of ES. To investigate possible sources of the organism for one of the flocks bacterial cultures were made from the environment, water lines, mice trapped on the farm, cecal/cloacal swabs from one of the parent broiler breeder flocks, egg residue, hatching eggs, and the hatchery environment. Except for cecal/cloacal swabs from the breeders, E. cecorum was not isolated from any of these samples. When compared phenotypically and genotypically, cecal/cloacal isolates of E. cecorum from the breeders differed from isolates from spondylitis lesions in the broilers. The source of E. cecorum for the broiler flocks was not determined, but vertical transmission appears unlikely.}, number={4}, journal={AVIAN DISEASES}, author={Robbins, Kabel M. and Suyemoto, M. Mitsu and Lyman, Roberta L. and Martin, Michael P. and Barnes, H. John and Borst, Luke B.}, year={2012}, month={Dec}, pages={768–773} }
 @article{johnson_logue_johnson_kuskowski_sherwood_barnes_debroy_wannemuehler_obata-yasuoka_spanjaard_et al._2012, title={Associations Between Multidrug Resistance, Plasmid Content, and Virulence Potential Among Extraintestinal Pathogenic and Commensal Escherichia coli from Humans and Poultry}, volume={9}, ISSN={["1535-3141"]}, DOI={10.1089/fpd.2011.0961}, abstractNote={The emergence of plasmid-mediated multidrug resistance (MDR) among enteric bacteria presents a serious challenge to the treatment of bacterial infections in humans and animals. Recent studies suggest that avian Escherichia coli commonly possess the ability to resist multiple antimicrobial agents, and might serve as reservoirs of MDR for human extraintestinal pathogenic Escherichia coli (ExPEC) and commensal E. coli populations. We determined antimicrobial susceptibility profiles for 2202 human and avian E. coli isolates, then sought for associations among resistance profile, plasmid content, virulence factor profile, and phylogenetic group. Avian-source isolates harbored greater proportions of MDR than their human counterparts, and avian ExPEC had higher proportions of MDR than did avian commensal E. coli. MDR was significantly associated with possession of the IncA/C, IncP1-α, IncF, and IncI1 plasmid types. Overall, inferred virulence potential did not correlate with drug susceptibility phenotype. However, certain virulence genes were positively associated with MDR, including ireA, ibeA, fyuA, cvaC, iss, iutA, iha, and afa. According to the total dataset, isolates segregated significantly according to host species and clinical status, thus suggesting that avian and human ExPEC and commensal E. coli represent four distinct populations with limited overlap. These findings suggest that in extraintestinal E. coli, MDR is most commonly associated with plasmids, and that these plasmids are frequently found among avian-source E. coli from poultry production systems.}, number={1}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Johnson, Timothy J. and Logue, Catherine M. and Johnson, James R. and Kuskowski, Michael A. and Sherwood, Julie S. and Barnes, H. John and DebRoy, Chitrita and Wannemuehler, Yvonne M. and Obata-Yasuoka, Mana and Spanjaard, Lodewijk and et al.}, year={2012}, month={Jan}, pages={37–46} }
 @article{borst_suyemoto_robbins_lyman_martin_barnes_2012, title={Molecular epidemiology of Enterococcus cecorum isolates recovered from enterococcal spondylitis outbreaks in the southeastern United States}, volume={41}, ISSN={["1465-3338"]}, DOI={10.1080/03079457.2012.718070}, abstractNote={Enterococcus cecorum, a normal intestinal inhabitant, is increasingly responsible for outbreaks of arthritis and osteomyelitis in chickens worldwide. Enterococcal spondylitis (ES) is a specific manifestation of E. cecorum-associated disease in which increased flock morbidity and mortality result from chronic infection involving the free thoracic vertebra. In this study the genetic relatedness and antimicrobial resistance of isolates recovered from ES-affected flocks in the southeastern United States were determined. ES outbreaks from 2007 to 2011 were investigated in North Carolina (15 flocks, 13 farms, four integrators), South Carolina (one flock, one farm, one integrator) and Alabama (six flocks, six farms, one integrator). From these 22 epidemiologically distinct outbreaks, 326 isolates of E. cecorum were recovered. Isolates from spinal lesions and caeca of affected birds (cases) and caeca of unaffected birds (controls) were genotyped using pulsed-field gel electrophoresis; phenotyped using both GenIII MicroPlate™ (Biolog; Hayward, CA, USA) microbial identification plates and antimicrobial sensitivity testing; and compared with each other. Isolates from spinal lesions were incapable of mannitol metabolism and the majority of these isolates were genetically clonal. In contrast, caecal isolates from control birds varied in their ability to metabolize mannitol and were genetically diverse. Isolates from both case and control birds had high levels of antimicrobial resistance. These findings indicate that the increase in E. cecorum-associated disease in the southeast United States is due to the emergence of new clones with increased pathogenicity and multidrug resistance.}, number={5}, journal={AVIAN PATHOLOGY}, author={Borst, Luke B. and Suyemoto, M. Mitsu and Robbins, Kabel M. and Lyman, Roberta L. and Martin, Michael P. and Barnes, H. John}, year={2012}, pages={479–485} }
 @article{bosquet_peedicayil_maguire_chien_rodriguez_whitaker_petitte_anderson_barnes_shridhar_et al._2011, title={Comparison of gene expression patterns between avian and human ovarian cancers}, volume={120}, ISSN={["1095-6859"]}, url={http://europepmc.org/abstract/med/21093898}, DOI={10.1016/j.ygyno.2010.10.030}, abstractNote={Objectives A putative model of spontaneous cancer has been described in the laying hen that bears significant similarities to human ovarian cancer. Our objective was to characterize and compare the patterns of gene expression in chicken and human forms of this disease. Methods RNA from 20 localized and metastatic ovarian and oviductal chicken tumor samples was isolated, amplified using in vitro transcription, and hybridized against normal ovarian epithelium to a customized cDNA microarray constructed for these studies. Differentially expressed genes were identified for localized ovarian, metastatic ovarian, and oviductal (or tubal) cancer by class comparison using BRB-ArrayTools. Results were validated with semi-quantitative PCR. A gene list (prediction model) constructed with the class prediction tool was used in a human ovarian cancer microarray obtained from the GEO datasets (GSE6008) in order to compare these results across species. Results Class comparison analysis between localized ovarian, metastatic ovarian and oviductal cancer yielded 41 different informative probes that coded for 27 unique genes. Localized ovarian samples clustered between metastatic ovarian and oviductal cancer samples. Using our chicken data as a training set and leaving oviductal samples out of the analysis, we created a prediction model that classified early stage and advanced stage human ovarian cancer gene expression arrays with 78% overall accuracy. Conclusions Gene expression of spontaneous ovarian cancer in the chicken is comparable to gene expression patterns of human ovarian cancer.}, number={2}, journal={GYNECOLOGIC ONCOLOGY}, author={Bosquet, Jesus Gonzalez and Peedicayil, Abraham and Maguire, Jacie and Chien, Jeremy and Rodriguez, Gustavo C. and Whitaker, Regina and Petitte, James N. and Anderson, Kenneth E. and Barnes, H. John and Shridhar, Viji and et al.}, year={2011}, month={Feb}, pages={256–264} }
 @article{martin_martin_barnes_2011, title={Experimental Reproduction of Enterococcal Spondylitis in Male Broiler Breeder Chickens}, volume={55}, ISSN={["1938-4351"]}, DOI={10.1637/9614-121410-reg.1}, abstractNote={Abstract There has been a recent emergence of epidemic spinal infections with necrosis causing lameness and mortality in male broilers and broiler breeders. Mortality in affected flocks may be as high as 15%. The disease has been called enterococcal spondylitis (ES), based on the frequent isolation of Enterococcus cecorum from the lesions and necrosis and inflammation observed in the free thoracic vertebrae (FTV) of affected birds. Male broiler breeders in an experimental setting were challenged with pure E. cecorum isolates obtained from ES-affected commercial flocks. Challenge routes included oral gavage (108), intravenous (IV; 103), and air sac (AS; 103). Half the study birds in each group were chemically immunosuppressed with dexamethasone. Spinal lesions were observed grossly in birds challenged intravenously (2.9%) and birds challenged orally (6.1%). Microscopic spinal lesions consistent with ES were more frequently identified compared with gross lesions in the orally challenged group (30.3%). Chemical immunosuppression with dexamethasone was not associated with a greater incidence of ES in this study. By recreating the disease experimentally, the study design reported here may help in the further development of an experimental challenge model for future studies on risk factors, prevention, and therapeutic intervention of ES.}, number={2}, journal={AVIAN DISEASES}, author={Martin, Leslie T. and Martin, Michael P. and Barnes, H. John}, year={2011}, month={Jun}, pages={273–278} }
 @article{tobias_barnes_law_2011, title={Pathology in Practice}, volume={239}, ISSN={["0003-1488"]}, DOI={10.2460/javma.239.8.1065}, number={8}, journal={JAVMA-JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION}, author={Tobias, Jeremy R. and Barnes, H. John and Law, J. McHugh}, year={2011}, month={Oct}, pages={1065–1067} }
 @article{carver_barnes_anderson_petitte_whitaker_berchuck_rodriguez_2011, title={Reduction of Ovarian and Oviductal Cancers in Calorie-Restricted Laying Chickens}, volume={4}, ISSN={["1940-6215"]}, url={http://europepmc.org/abstract/med/21325563}, DOI={10.1158/1940-6207.capr-10-0294}, abstractNote={Abstract}, number={4}, journal={CANCER PREVENTION RESEARCH}, author={Carver, Donna K. and Barnes, H. John and Anderson, Kenneth E. and Petitte, James N. and Whitaker, Regina and Berchuck, Andrew and Rodriguez, Gustavo C.}, year={2011}, month={Apr}, pages={562–567} }
 @article{martin_wineland_fletcher_barnes_2011, title={Selected Blood Chemistry Values in Mobility-Impaired Broiler Breeder Hens with Suspected Calcium Tetany Using the i-STAT (R) Handheld Clinical Analyzer}, volume={55}, ISSN={["0005-2086"]}, DOI={10.1637/9566-100610-reg.1}, abstractNote={SUMMARY. Calcium tetany is a poorly defined disease of broiler breeder hens that results from acute hypocalcemia. It is characterized by impaired mobility, increased mortality, and absence of gross lesions that would explain the impaired mobility. To evaluate if hens with impaired mobility had calcium tetany or other abnormalities, blood values from normal and affected hens were determined using the i-STAT® handheld clinical analyzer. Three flocks were evaluated weekly prior to peak production (range 25–30 wk of age) comparing normal hens to hens with clinically apparent calcium tetany. Calcium tetany suspect (CaTS) hens from four additional flocks were also evaluated. Significant hypocalcemia (P < 0.001) was observed in CaTS hens (average  =  1.14 mmol/L ionized calcium [iCa]) compared to normal hens (average  =  1.53 mmol/L iCa) in only one of three flocks sampled weekly. Clinically affected hens from one of the other four flocks also had hypocalcemia. Blood value abnormalities in mobility-impaired hens without hypocalcemia included hypernatremia. Findings in this study indicate calcium tetany is one cause of impaired mobility in breeder hens, but mobility impairment without hypocalcemia can also occur. Calcium tetany should be confirmed by finding significantly decreased levels of iCa in the blood, as diagnosis based on clinical presentation and necropsy results can be inaccurate. The i-STAT® handheld clinical analyzer is an efficient, relatively low-cost method to determine iCa and other blood chemistry values that may be associated with impaired mobility in broiler breeder hens.}, number={3}, journal={AVIAN DISEASES}, author={Martin, Michael P. and Wineland, Michael and Fletcher, Oscar J. and Barnes, H. John}, year={2011}, month={Sep}, pages={340–345} }
 @article{van wettere_degernes_barnes_2010, title={Combined hepatocellular-cholangiocarcinoma in a lesser flamingo (Phoenicopterus minor)}, volume={39}, ISSN={["1465-3338"]}, DOI={10.1080/03079457.2010.493553}, abstractNote={A case of combined hepatocellular-cholangiocarcinoma (CHCC) in an adult male lesser flamingo (Phoenicopterus minor) that was part of a breeding programme at a private facility is reported. Grossly, the liver was markedly enlarged with multifocal, well-circumscribed, pinpoint to 2 cm diameter pale tan nodular masses. Histologically, the hepatic parenchyma was replaced by neoplastic cells that demonstrated hepatocellular and, less frequently, biliary epithelial cell differentiation. Positive pan-cytokeratin (AE1/AE3/PCK26) immunolabelling of the neoplastic cells forming bile ducts with the scattered immunoreactivity of cells forming glandular structures within the areas of hepatocellular differentiation supported the diagnosis. No metastases were detected. CHCC is a rare neoplasm in mammals and birds. This is the first report where gross, histological, and immunohistochemical characteristics of CHCC in a bird are described, and the first report of CHCC in a lesser flamingo.}, number={4}, journal={AVIAN PATHOLOGY}, author={Van Wettere, A. J. and Degernes, L. A. and Barnes, H. John}, year={2010}, pages={275–278} }
 @article{temple_miyamoto_mehta_capitini_von stetina_barnes_christensen_horton_spears_orndorff_2010, title={Identification and Characterization of Two Bordetella avium Gene Products Required for Hemagglutination}, volume={78}, ISSN={["1098-5522"]}, DOI={10.1128/iai.00140-10}, abstractNote={ABSTRACT}, number={6}, journal={INFECTION AND IMMUNITY}, author={Temple, Louise M. and Miyamoto, David M. and Mehta, Manju and Capitini, Christian M. and Von Stetina, Stephen and Barnes, H. John and Christensen, Vern L. and Horton, John R. and Spears, Patricia A. and Orndorff, Paul E.}, year={2010}, month={Jun}, pages={2370–2376} }
 @article{ley_marusak_vivas_barnes_fletcher_2010, title={Mycoplasma iowae associated with chondrodystrophy in commercial turkeys}, volume={39}, ISSN={["0307-9457"]}, DOI={10.1080/03079451003599276}, abstractNote={Opportunistic observations of and necropsies from selected commercial (meat) turkey flocks revealed skeletal lesions consistent with chondrodystrophy, characterized by leg and vertebral deformities, occurring at very low incidences in turkeys from two primary breeds and various multiplier breeder flocks. Mycoplasma organisms were cultured and identified as Mycoplasma iowae by immunofluorescence and polymerase chain reaction from some of the vertebral lesions but not from leg joints. This is the first detailed description of the gross and microscopic lesions of vertebral chondrodystrophy associated with M. iowae, which should now be considered in the differential diagnosis of turkeys with these lesions.}, number={2}, journal={AVIAN PATHOLOGY}, author={Ley, David H. and Marusak, Rosemary A. and Vivas, Eduardo J. and Barnes, H. John and Fletcher, Oscar J.}, year={2010}, pages={87–93} }
 @article{martin_wineland_barnes_2010, title={Selected Blood Chemistry and Gas Reference Ranges for Broiler Breeders Using the i-STAT (R) Handheld Clinical Analyzer}, volume={54}, ISSN={["0005-2086"]}, DOI={10.1637/9223-122209-reg.1}, abstractNote={Abstract Selected blood chemistry and gas reference ranges for clinically healthy broiler breeder hens were established using CG8+ cartridges in an i-STAT® handheld point-of-care clinical analyzer. Samples from 165 hens (25–36 wk of age), representing three broiler breeder strains reared by four integrators, were evaluated. A standardized sampling technique was developed to minimize instrument error readings. The following reference ranges and means, respectively, were determined: sodium (141.6–152.6, 147.1 [mmol/L]), potassium (4.1–5.7, 4.9 [mmol/L]), ionized calcium (1.20–1.73, 1.47 [mmol/L]), glucose (207.2–260.7, 234.0 [mg/dl]), hematocrit (21.3–30.8, 26.1 [% packed cell volume]), hemoglobin (7.3–10.5, 8.9 [g/dl]), pH (7.28–7.57, 7.42), carbon dioxide partial pressure (25.9–49.5, 37.7 [mm Hg]), oxygen partial pressure (32.0–60.5, 46.2 [mm Hg]), bicarbonate (18.9–30.3, 24.6 [mmol/L]), total carbon dioxide (19.9–31.5, 25.7 [mmol/L]), base excess (−6.8 to 7.2, 0.2), and oxygen saturation (70.6–93.3, 82.0 [%]). Wide ranges in blood gases and base excess occurred in all strains. Cobb strain hens had significantly lower glucose and higher partial and saturated oxygen values compared with two Ross strains. Significant differences in several blood parameters were found among different integrators and in older postpeak production birds. The i-STAT handheld point-of-care clinical analyzer provides rapid, relatively low cost, blood chemistry values that are useful for investigating broiler breeder flock diseases of unknown or uncertain etiology, especially those suspected of having a metabolic cause.}, number={3}, journal={AVIAN DISEASES}, author={Martin, Michael P. and Wineland, Michael and Barnes, H. John}, year={2010}, month={Sep}, pages={1016–1020} }
 @article{reynolds_barnes_wolfe_lu_camp_malarkey_2009, title={Bilateral Nocardial Endophthalmitis in a Prothonotary Warbler (Protonotaria citrea)}, volume={46}, ISSN={["1544-2217"]}, DOI={10.1354/vp.46-1-120}, abstractNote={ A 7-year-old captive female prothonotary warbler (Protonotaria citrea) died following chronic feather and weight loss. At necropsy, the right eye had a 2 X 2 X 1 mm corneal plaque of inspissated yellow-tan material and edema of the lower eyelid. Microscopically, both eyes exhibited diffuse, severe pyogr anulomatous endophthalmitis with retinal necrosis and detachment. Numerous intralesional branching, gram-positive, beaded, filamentous bacteria formed a thick mat attached to the retinal pigmented epithelium and extending into the pecten. Bacteria were strongly acid-fast positive by Fite's stain but only occasionally acid-fast positive by Ziehl-Neelsen staining, a characteristic consistent with a Nocardia spp. Infected regions demonstrated positive in situ hybridization reactivity with a probe complementary to the 16S rRNA gene of Nocardia spp. There was no evidence of primary bacterial infection in the other organs examined. }, number={1}, journal={VETERINARY PATHOLOGY}, author={Reynolds, T. L. and Barnes, H. J. and Wolfe, B. and Lu, L. and Camp, D. M. and Malarkey, D. E.}, year={2009}, month={Jan}, pages={120–123} }
 @article{hakim_barry_barnes_anderson_petitte_whitaker_lancaster_wenham_carver_turbov_et al._2009, title={Ovarian Adenocarcinomas in the Laying Hen and Women Share Similar Alterations in p53, ras, and HER-2/neu}, volume={2}, ISSN={["1940-6215"]}, url={http://europepmc.org/abstract/med/19174584}, DOI={10.1158/1940-6207.CAPR-08-0065}, abstractNote={Abstract}, number={2}, journal={CANCER PREVENTION RESEARCH}, author={Hakim, Amy A. and Barry, Catherine P. and Barnes, H. John and Anderson, Kenneth E. and Petitte, James and Whitaker, Regina and Lancaster, Jonathan M. and Wenham, Robert M. and Carver, Donna K. and Turbov, Jane and et al.}, year={2009}, month={Feb}, pages={114–121} }
 @article{monleon_martin_barnes_2008, title={Bacterial orchitis and epididymo-orchitis in broiler breeders}, volume={37}, ISSN={["0307-9457"]}, DOI={10.1080/03079450802499134}, abstractNote={Two cases of orchitis and epididymo-orchitis in broiler breeders are described. The first case occurred in a 62-week-old rooster showing signs of breeding inactivity. Grossly, the left testis was abnormally shaped and had multiple yellow foci, prominent blood vessels, and a gelatinous mass on the surface. The right testis and other tissues appeared normal. A pure, heavy growth of Staphylococcus aureus was obtained on bacterial culture, and intralesional Gram-positive cocci were numerous on histopathology. The second case occurred in a 28-week-old rooster that was found dead. Both testes were abnormally shaped, swollen, firm, and had irregular, dark, depressed areas, prominent vessels, and multiple petechial haemorrhages. Epididymides were enlarged and nodular. Other lesions in this rooster included poor nutritional condition, distended cloaca, and urate scalding of the abdominal skin below the vent. Microscopically, there was extensive, severe heterophilic intratubular orchitis and epididymitis with intralesional Gram-negative bacteria. A heavy, pure growth of Escherichia coli was obtained from the testes and epididymides. In both cases, the findings suggested that the most probable route of infection was ascending via the ductus deferens.}, number={6}, journal={AVIAN PATHOLOGY}, author={Monleon, Rafael and Martin, Michael P. and Barnes, H. John}, year={2008}, pages={613–617} }
 @article{osorio_fletcher_dykstra_post_barnes_2007, title={Comb candidiasis affecting roosters in a broiler breeder flock}, volume={51}, ISSN={["0005-2086"]}, DOI={10.1637/0005-2086(2007)51[618:CCARIA]2.0.CO;2}, abstractNote={Abstract A cutaneous mycosis caused by Candida albicans that involved the combs and less frequently the wattles, facial skin, ear lobes, and neck of male broiler breeders is described. Roosters were 35 wk old and housed with hens in two conventional broiler breeder houses on a farm in western North Carolina. Morbidity was approximately 10% in one house and less than 2% in the other house. Mortality and flock fertility were not affected. Three birds from the most affected house were examined. All birds had white adherent material on their combs that presented as crusty patches or lighter diffuse areas. Often, lesions were roughly circular or had a defined margin. Small black scabs were present in a few lesions. Similar but less extensive lesions were located on the wattles, facial skin, ear lobes, and rictus. In one bird, lesions extended down the neck, and they were accompanied by hyperemia and feather loss. Hyperkeratosis with little to no inflammation and intralesional fungi occurring as yeast and pseudohyphae were seen microscopically. High numbers of C. albicans were isolated and identified from the lesions.}, number={2}, journal={AVIAN DISEASES}, author={Osorio, Claudia and Fletcher, Oscar and Dykstra, Michael J. and Post, Karen and Barnes, H. John}, year={2007}, month={Jun}, pages={618–622} }
 @article{martin_bouck_helm_dykstra_wages_barnes_2007, title={Disseminated Aspergillus flavus infection in broiler breeder pullets}, volume={51}, ISSN={["1938-4351"]}, DOI={10.1637/0005-2086(2007)51[626:DAFIIB]2.0.CO;2}, abstractNote={Abstract Increased morbidity and mortality occurred in a 5-wk-old broiler breeder replacement pullet flock. The affected broiler pullet flock was housed on the first floor of a two-story confinement building. Mortality increased to 0.1%/day compared to the flock on the second floor, which had mortality levels of less than 0.01%/day. Clinical signs in the affected chickens included inactivity, decreased response to stimuli, and anorexia. No respiratory or neurologic signs were observed. On necropsy, affected pullets were dehydrated and emaciated and had disseminated variably sized single or multiple heterophilic granulomas that contained intralesional septate and branching fungal hyphae. Lesions were extensive around the base of the heart in the thoracic inlet and in the kidneys. Other affected organs included eyelid, muscle, proventriculus, ventriculus, intestine, liver, spleen, lung, and heart. Aspergillus flavus was cultured from the visceral granulomas. The source of flock exposure to the organism was not determined.}, number={2}, journal={AVIAN DISEASES}, author={Martin, Michael P. and Bouck, Karla Pecelunas and Helm, Julie and Dykstra, Michael J. and Wages, Dennis P. and Barnes, H. John}, year={2007}, month={Jun}, pages={626–631} }
 @article{sanei_barnes_vaillancourt_ley_2007, title={Experimental infection of chickens and turkeys with Mycoplasma gallisepticum reference strain S6 and North Carolina field isolate RAPD type B}, volume={51}, ISSN={["0005-2086"]}, DOI={10.1637/0005-2086(2007)051[0106:EIOCAT]2.0.CO;2}, abstractNote={Abstract During an epidemic of mycoplasmosis in chicken and turkey flocks in North Carolina between 1999 and 2001, isolates of Mycoplasma gallisepticum (MG) from affected flocks were characterized by random amplification of polymorphic DNA (RAPD), and eight distinct RAPD types were identified. MG RAPD type B accounted for more than 90% of the isolates and was associated with moderate-to-severe clinical signs and mortality. The virulence of MG RAPD type B for chickens and turkeys was compared with sham-inoculated negative controls and MG S6 (a virulent strain)-inoculated positive controls. Clinical signs occurred in chickens and turkeys inoculated with either MG RAPD type B or MG S6. However, they were not as frequent or severe as those seen in naturally affected flocks, and there was no mortality in the experimental groups. Based on gross and microscopic findings, MG RAPD type B was equal to or more virulent than MG S6. All MG-inoculated birds were culture and PCR positive at 7 and 14 days postinoculation (PI). Among serological tests, the serum plate agglutination test was positive for the majority of chickens and turkeys (58%–100%) infected with either strain of MG at both 7 and 14 days PI. The hemagglutination inhibition test was negative for all birds at 7 days PI and positive for a few chickens (8%–17%) and several turkey sera (40%–60%) at 14 days PI. Only a single serum was positive by enzyme-linked immunosorbent assay (an MG S6-infected turkey) at 14 days PI.}, number={1}, journal={AVIAN DISEASES}, author={Sanei, B. and Barnes, H. J. and Vaillancourt, J. P. and Ley, D. H.}, year={2007}, month={Mar}, pages={106–111} }
 @article{guy_smith_evans_barnes_2007, title={Experimental reproduction of transmissible viral proventriculitis by infection of chickens with a novel adenovirus-like virus (Isolate R11/3)}, volume={51}, ISSN={["0005-2086"]}, DOI={10.1637/0005-2086(2007)051[0058:EROTVP]2.0.CO;2}, abstractNote={Abstract Transmissible viral proventriculitis (TVP) was experimentally reproduced in 2-wk-old specific-pathogen-free chickens and commercial broiler chickens by eyedrop inoculation of adenovirus-like virus (AdLV), isolate R11/3. No clinical signs and no weight gain depression were observed in chickens inoculated with AdLV (R11/3); however, gross and microscopic lesions characteristic of TVP were present in proventriculi of inoculated chickens. Proventriculi of AdLV (R11/3)–inoculated chickens were markedly enlarged, compared with sham-inoculated controls, by day 7 postinoculation (PI). Microscopic lesions in proventriculi of inoculated chickens were detected beginning on day 3 PI and consisted of degeneration and necrosis of glandular epithelium, ductal epithelial hyperplasia, replacement of glandular epithelium with ductal epithelium, and diffuse interstitial lymphoid infiltration; no microscopic lesions were observed in other tissues. AdLV (R11/3) antigens were detected in proventriculi by immunohistochemistry on days 3–10 PI in inoculated SPF chickens and days 3–21 PI in inoculated commercial broiler chickens; no viral antigens were detected in other tissues. AdLV (R11/3) was reisolated from proventriculi of inoculated SPF and commercial broiler chickens on days 5 and 7 PI. No virus, viral antigens, or lesions were detected in proventriculi collected from sham-inoculated chickens. These findings indicate an etiologic role for AdLV (R11/3) in TVP.}, number={1}, journal={AVIAN DISEASES}, author={Guy, James S. and Smith, Lynda G. and Evans, Maria E. and Barnes, H. John}, year={2007}, month={Mar}, pages={58–65} }
 @article{roza_martin_barnes_2006, title={Litter impaction of the lower intestinal tract in male broiler breeders}, volume={50}, ISSN={["0005-2086"]}, DOI={10.1637/7500-010906R.1}, abstractNote={Abstract Increased mortality occurred among males in a house of 26-wk-old broiler breeders. A severe impaction of the lower intestinal tract, because of litter, was found on necropsy in two of three recently dead cockerels. Litter could be seen in the markedly distended vent of the most affected bird. This bird also had feces and litter in the body cavity because of a ruptured small intestine. Both birds had extensive urate and fecal soiling of feathers around the vent. Other visceral organs were normal except for lack of fat around the base of the heart and decreased myocardial tone. Impaction of the lower intestinal tract in these birds most likely resulted from eating litter because of a change in feeding regimen, which caused confusion and feed competition among male birds.}, number={3}, journal={AVIAN DISEASES}, author={Roza, Kristen and Martin, Michael and Barnes, H. John}, year={2006}, month={Sep}, pages={460–462} }
 @article{alfonso_barnes_2006, title={Neonatal osteomyelitis associated with Staphylococcus aureus in turkey poults}, volume={50}, ISSN={["0005-2086"]}, DOI={10.1637/7298-110104R.1}, abstractNote={Abstract A case of Staphylococcus aureus infection causing osteomyelitis in young turkey poults is described. Mortality during the first week after hatching was 12.6%. Poults showed leg weakness, inflammation of all four toes, swelling of feet and hock joints, and osteomyelitis of the proximal tibiotarsus. Staphylococcus aureus was isolated from exudate in the hock joints and footpads. Granulocytic infiltration and colonies of gram-positive coccoid bacteria compatible with S. aureus were found on microscopic examination of the lesions. Toe trimming after hatching is believed to have provided a portal of entry for S. aureus, which resulted in infection of the toes and spread along tendons to joints and bones of the leg. Neonatal staphylococcal osteomyelitis should be considered when recently placed turkey flocks experience increased mortality, especially if they develop severe swelling and inflammation of toes following trimming and have enlarged swollen feet, tendons, or joints.}, number={1}, journal={AVIAN DISEASES}, author={Alfonso, M and Barnes, HJ}, year={2006}, month={Mar}, pages={148–151} }
 @inbook{barnes_2005, title={Avian chlamydiosis}, ISBN={0911910506}, booktitle={Merck veterinary manual}, publisher={Whitehouse Station, N.J. : Merck}, author={Barnes, H. J.}, editor={Kahn, C.M. and Line, S.Editors}, year={2005} }
 @inbook{barnes_2005, title={Bloodborne organisms}, ISBN={0911910506}, booktitle={Merck veterinary manual}, publisher={Whitehouse Station, N.J. : Merck}, author={Barnes, H. J.}, editor={Kahn, C.M. and Line, S.Editors}, year={2005} }
 @article{alfonso_adochiles_hendrickson_carver_rodriguez_barnes_2005, title={Metastatic adenocarcinoma in the lungs of older laying hens}, volume={49}, ISSN={["0005-2086"]}, DOI={10.1637/0005-2086(2005)49[430:MAITLO]2.0.CO;2}, abstractNote={Abstract As part of a study on ovarian and oviductal adenocarcinomas in older laying hens, 676 commercial egg-laying chickens were necropsied at 4 yr of age. Tumors were identified in 305 (45.1%) of the hens. Grossly visible metastatic tumors in the lungs of a few birds prompted collection of lungs from 228 affected hens for histologic examination. Metastatic adenocarcinomas were identified histologically in the lungs of 42 of the 228 hens (18.4%). The number of tumors and extent of involvement of the lung parenchyma varied from minimal to extensive. Tumor emboli were occasionally seen in pulmonary vessels. Metastatic foci showing expansive or invasive growth were identified. These findings indicate that vascular spread of adenocarcinomas is more common than previously thought in chickens, and the lungs are often involved with metastatic tumors, primarily from the reproductive tract.}, number={3}, journal={AVIAN DISEASES}, author={Alfonso, M and Adochiles, L and Hendrickson, VM and Carver, DK and Rodriguez, GC and Barnes, HJ}, year={2005}, month={Sep}, pages={430–432} }
 @article{guy_barnes_smith_owen_fuller_2005, title={Partial characterization of an adenovirus-like virus isolated from broiler chickens with transmissible viral proventriculitis}, volume={49}, ISSN={["0005-2086"]}, DOI={10.1637/7352-030205R.1}, abstractNote={Abstract Transmissible viral proventriculitis (TVP) was experimentally reproduced in specific-pathogen-free chickens using a homogenate of proventricular tissue obtained from TVP-affected commercial broiler chickens. Thin-section electron microscopy revealed intranuclear, approximately 70-nanometer (nm), adenovirus-like viruses (AdLV) within proventricular lesions. The AdLV, designated AdLV (R11/3), could not be propagated using various avian and mammalian cell cultures or by inoculation of embryonated chicken eggs by yolk, allantoic, or chorioallantoic membrane routes. However, AdLV (R11/3) was successfully propagated by amniotic inoculation of embryonated chicken eggs, with detection of the virus in proventriculi and intestinal contents of hatched 2-day-old chicks (8 days postinoculation). Virus propagation was evident in in ovo–inoculated chicks by 1) gross and microscopic lesions in proventriculi consistent with TVP, 2) immunohistochemical localization of AdLV (R11/3) antigens in proventricular epithelium, 3) thin-section electron microscopic detection of intranuclear, approximately 70-nm AdLVs within proventricular epithelium, and 4) negative-stain electron microscopic detection of extracellular, approximately 70-nm AdLVs in intestinal contents. Indirect immunofluorescence and polymerase chain reaction procedures that specifically recognize groups I, II, and III avian adenoviruses failed to recognize AdLV (R11/3). The findings suggest an etiologic role for AdLV (R11/3) in TVP and indicate that this virus is distinct from known avian adenoviruses.}, number={3}, journal={AVIAN DISEASES}, author={Guy, JS and Barnes, HJ and Smith, L and Owen, R and Fuller, FJ}, year={2005}, month={Sep}, pages={344–351} }
 @article{lee_reimers_barnes_d'lima_carver_kathariou_2005, title={Strain persistence and fluctuation of multiple-antibiotic resistant Campylobacter coli colonizing turkeys over successive production cycles}, volume={2}, ISSN={["1556-7125"]}, DOI={10.1089/fpd.2005.2.103}, abstractNote={The dynamics of colonization of turkeys by thermophilic campylobacters that are resistant to multiple antibiotics is poorly understood. In this study, we monitored cecal colonization of turkeys by Campylobacter over three successive production cycles at the same farm. Campylobacter isolated from the ceca was predominantly C. coli in all three flocks. Isolates with two distinct fla types that represented a single clonal group based on pulsed-field gel electrophoresis and that were resistant to multiple antibiotics (tetracycline, streptomycin, ampicillin, erythromycin, kanamycin, nalidixic acid, and ciprofloxacin) predominated throughout the three production cycles. The relative prevalence of each fla type, however, varied significantly from one flock to the next. The repeated isolation of these multiresistant C. coli from successive flocks likely reflected persistence of the organisms in currently unknown reservoirs in the production environment or, alternatively, repeated introduction events followed by establishment of these bacteria in each successive flock.}, number={1}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Lee, Bong Choon and Reimers, Nancy and Barnes, H. John and D'Lima, Carol and Carver, Donna and Kathariou, Sophia}, year={2005}, pages={103–110} }
 @article{smith_reimers_barnes_lee_siletzky_kathariou_2004, title={Campylobacter colonization of sibling turkey flocks reared under different management conditions}, volume={67}, ISSN={["1944-9097"]}, DOI={10.4315/0362-028X-67.7.1463}, abstractNote={Uncertainty exists concerning the key factors contributing to Campylobacter colonization of poultry, especially the possible role of vertical transmission from breeder hens to young birds. A longitudinal study of Campylobacter colonization was performed in two sibling pairs of turkey flocks (four flocks total). Each pair of sibling flocks shared breeder hen populations and was obtained from the same hatchery. One flock of each pair was grown on a commercial farm, and the other was grown in an instructional demonstration unit (Teaching Animal Unit [TAU]). Flocks were located within a 60-mi (96.8-km) radius. The time of placement, feed formulations, stocking density, and general husbandry were the same for both flocks, and each flock was processed at a commercial processing plant following standard feed withdrawal and transport protocols. Both flocks grown on the commercial farms became colonized with Campylobacter between weeks 2 and 3 and remained colonized until processing. Between 80 and 90% of isolates were Campylobacter coli, and the remainder were Campylobacter jejuni. In contrast, neither C. coli nor C. jejuni were isolated from either of the TAU flocks at any time during the production cycle. None of the fla types of Campylobacter from the breeders that provided poults to one of the commercial flocks matched those from the progeny. These results failed to provide evidence for vertical transmission and indicate that this type of transmission either did not occur or was not sufficient to render the TAU turkey flocks Campylobacter positive. Management practices such as proper litter maintenance, controlled traffic between the TAU farm and other turkey flocks, and other less well-defined aspects of turkey production were likely responsible for the absence of Campylobacter in the TAU flocks before harvest.}, number={7}, journal={JOURNAL OF FOOD PROTECTION}, author={Smith, K and Reimers, N and Barnes, HJ and Lee, BC and Siletzky, R and Kathariou, S}, year={2004}, month={Jul}, pages={1463–1468} }
 @article{pakpinyo_ley_barnes_vaillancourt_guy_2003, title={Enhancement of enteropathogenic Escherichia coli pathogenicity in young turkeys by concurrent turkey coronavirus infection}, volume={47}, ISSN={["0005-2086"]}, DOI={10.1637/0005-2086(2003)047[0396:EOEECP]2.0.CO;2}, abstractNote={Abstract In a previous study, turkey coronavirus (TCV) and enteropathogenic Escherichia coli (EPEC) were shown to synergistically interact in young turkeys coinfected with these agents. In that study, inapparent or mild disease was observed in turkeys inoculated with only TCV or EPEC, whereas severe growth depression and high mortality were observed in dually inoculated turkeys. The purpose of the present study was to further evaluate the pathogenesis of combined TCV/EPEC infection in young turkeys and determine the role of these agents in the observed synergistic interaction. Experiments were conducted to determine 1) effect of EPEC dose, with and without concurrent TCV infection, and 2) effect of TCV exposure, before and after EPEC exposure, on development of clinical disease. Additionally, the effect of combined infection on TCV and EPEC shedding was determined. No clinical sign of disease and no attaching and effacing (AE) lesions characteristic of EPEC were observed in turkeys inoculated with only EPEC isolate R98/5, even when turkeys were inoculated with 1010 colony forming units (CFU) EPEC (high dose exposure). Only mild growth depression was observed in turkeys inoculated with only TCV; however, turkeys inoculated with both TCV and 104 CFU EPEC (low dose exposure) developed severe disease characterized by high mortality, marked growth depression, and AE lesions. Inoculation of turkeys with TCV 7 days prior to EPEC inoculation produced more severe disease (numerically greater mortality, significantly lower survival probability [P < 0.05], increased frequency of AE lesions) than that observed in turkeys inoculated with EPEC prior to TCV or simultaneously inoculated with these agents. Coinfection of turkeys with TCV and EPEC resulted in significantly increased (P < 0.05) shedding of EPEC, but not TCV, in intestinal contents of turkeys. These findings indicate that TCV infection predisposes young turkeys to secondary EPEC infection and potentiates the expression of EPEC pathogenicity in young turkeys.}, number={2}, journal={AVIAN DISEASES}, author={Pakpinyo, S and Ley, DH and Barnes, HJ and Vaillancourt, JP and Guy, JS}, year={2003}, pages={396–405} }
 @article{mathews_danova_newman_barnes_phillips_2003, title={Ratite cancellous xenograft: Effects on avian fracture healing}, volume={16}, DOI={10.1055/s-0038-1632746}, abstractNote={Summary}, number={1}, journal={Veterinary and Comparative Orthopaedics and Traumatology}, author={Mathews, K. G. and Danova, A. and Newman, H. and Barnes, H. J. and Phillips, L.}, year={2003}, pages={50–58} }
 @article{carver_fetrow_gerig_krueger_barnes_2002, title={Hatchery and transportation factors associated with early poult mortality in commercial turkey flocks}, volume={81}, ISSN={["0032-5791"]}, DOI={10.1093/ps/81.12.1818}, abstractNote={A prospective ecologic study, using routinely collected data from commercial turkey companies, was done of 312 turkey flocks placed over a 1-yr period. The objective was to identify hatchery- and transportation-associated risk factors for poult mortality in the first 14 d after placement using statistical models. Logistic regression was used to determine the effects of hatchery-and transportation-related factors on odds of mortality for hen and tom flocks separately. Hatchery and transportation-related risk factors for hen flock mortality included truck, truck temperature, and number of poults dead on arrival at the farm. Hatchery and transportation-related risk factors for tom flock mortality included desnooding, truck, truck temperature, shipping time, and weather conditions at placement.}, number={12}, journal={POULTRY SCIENCE}, author={Carver, DK and Fetrow, J and Gerig, T and Krueger, KK and Barnes, HJ}, year={2002}, month={Dec}, pages={1818–1825} }
 @article{barnes_2002, title={PEC: What is it and what is the economic significance?}, volume={18}, ISBN={1388-3119}, journal={World Poultry (Doetinchem, Netherlands)}, author={Barnes, H. J.}, year={2002}, pages={14} }
 @article{pakpinyo_ley_barnes_vaillancourt_guy_2002, title={Prevalence of Enteropathogenic Escherichia coli in Naturally Occurring Cases of Poult Enteritis–Mortality Syndrome}, volume={46}, ISSN={0005-2086 1938-4351}, url={http://dx.doi.org/10.1637/0005-2086(2002)046[0360:poeeci]2.0.co;2}, DOI={10.1637/0005-2086(2002)046[0360:POEECI]2.0.CO;2}, abstractNote={SUMMARY. Enteropathogenic Escherichia coli (EPEC) previously were identified in poult enteritis–mortality syndrome (PEMS)-affected turkeys and associated as a cause of this disease. In the present study, the prevalence of EPEC in PEMS-affected turkeys was examined retrospectively with archived tissues and intestinal contents collected from 12 PEMS-affected turkey flocks in 1998. Formalin-fixed intestinal tissues were examined by light and electron microscopy for attaching and effacing (AE) lesions characteristic of EPEC, and frozen (−75 C) intestinal contents were examined for presence of EPEC. Escherichia coli isolates were characterized on the basis of epithelial cell attachment, fluorescent actin staining (FAS) test, and presence of E. coli attaching/effacing (EAE), shigalike toxin (SLT) type I, SLT II, and bundle-forming pilus (BFP) genes by polymerase chain reaction procedures. EPEC isolates were examined for pathogenicity and ability to induce AE lesions in experimentally inoculated young turkeys. AE lesions were identified by light microscopy in Giemsa-stained intestines from 7 of 12 PEMS-affected turkey flocks. Lesions consisted of bacterial microcolonies attached to epithelial surfaces with epithelial degeneration at sites of attachment and inflammatory infiltration of the lamina propria. Electron microscopy confirmed the identity of AE lesions in six of seven flocks determined to have AE lesions by light microscopy. EPEC were identified in 4 of 12 flocks on the basis of the presence of EAE genes and absence of SLT I and SLT II genes; all isolates lacked BFP genes. EPEC isolates produced AE lesions and variable mortality in turkeys coinfected with turkey coronavirus. In total, EPEC were associated with 10 of 12 (83%) naturally occurring PEMS cases on the basis of identification of AE lesions and/or EPEC isolates. These findings provide additional evidence suggesting a possible role for EPEC in the pathogenesis of PEMS.}, number={2}, journal={Avian Diseases}, publisher={American Association of Avian Pathologists (AAAP)}, author={Pakpinyo, S. and Ley, D. H. and Barnes, H. J. and Vaillancourt, J. P. and Guy, J. S.}, year={2002}, month={Apr}, pages={360–369} }
 @article{carver_vaillancourt_stringham_guy_barnes_2001, title={Mortality patterns associated with poult enteritis mortality syndrome (PEMS) and coronaviral enteritis in turkey flocks raised in PEMS-affected regions}, volume={45}, ISSN={["0005-2086"]}, DOI={10.2307/1592878}, abstractNote={Poult enteritis mortality syndrome (PEMS) is an economically devastating disease. To date, many questions about the syndrome remain unanswered, including its cause, transmission of causative agent(s), and control methods. Turkey coronavirus (TCV) infection has been associated with some outbreaks of PEMS, with areas having a higher prevalence of TCV infection also experiencing an increased incidence of PEMS. This study was designed to establish mortality patterns for flocks experiencing excess mortality and TCV infection in PEMS-affected regions and to delineate the possible role of TCV in PEMS-affected flocks. Fifty-four commercial turkey flocks on farms in areas with and without a history of TCV infection were monitored for weekly mortality and for antibodies to TCV. Flocks were chosen on the basis of placement dates and were monitored from day of placement until processing. All flocks were tested for TCV by an indirect fluorescent antibody assay. PEMS status was determined with the use of the clinical definition of mortality greater than 2% during any 3-wk period from 2 wk of age through the end of brooding due to unknown cause. Of the 54 flocks, 24 remained healthy, 23 experienced PEMS, and 7 tested positive for TCV but did not experience PEMS. Ten flocks experienced PEMS and tested positive for TCV, whereas 13 flocks experienced PEMS and did not test positive for TCV. Four health status groups were evident: healthy, PEMS positive, TCV positive, and PEMS + TCV positive. Distinct mortality patterns were seen for each of the four health status groups. Whereas TCV was associated with PEMS in 43% of PEMS cases, 13 cases (57%) of PEMS did not involve TCV. Additionally, 7 out of 17 cases of TCV (41%) did not experience excess mortality (PEMS) at any time during brooding of the flock. The results of this study indicate that TCV can be associated with PEMS but is neither necessary nor sufficient to cause PEMS.}, number={4}, journal={AVIAN DISEASES}, author={Carver, DK and Vaillancourt, JP and Stringham, M and Guy, JS and Barnes, HJ}, year={2001}, pages={985–991} }
 @article{heggen_qureshi_edens_barnes_2000, title={Alterations in macrophage-produced cytokines and nitrite associated with poult enteritis and mortality syndrome}, volume={44}, ISSN={["0005-2086"]}, DOI={10.2307/1592508}, abstractNote={Poult enteritis and mortality syndrome (PEMS) is an acute, transmissible, infectious intestinal disease associated with high mortality and morbidity in turkey poults. Earlier studies demonstrated immune dysfunction, involving both humoral and cell-mediated immunity, associated with PEMS. The current study examined cytokines and metabolites produced by macrophages from poults exposed to PEMS agent(s). Six trials were conducted with six separate hatches of poults. Poults in the PEMS group were exposed to PEMS agent(s) via contact exposure at 7 days of age whereas uninfected poults served as control poults. Abdominal macrophages were harvested from control (uninfected) and PEMS poults at various times postexposure and cultured for 18-24 hr in the presence of Escherichia coli lipopolysaccharide. Interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) bioactivities and nitrite levels in macrophage culture supernatants were quantified. Macrophage supernatants from PEMS poults had greater IL-1-mediated stimulation index compared with the macrophage supernatants from uninfected control poults in both trials. However, this increase was significant only in trial 1. IL-6 activity tested in three separate trials was significantly higher in PEMS macrophage supernatants over the controls. On the contrary, TNF-alpha production by macrophages was decreased in PEMS macrophage culture supernatants. Nitrite levels in PEMS macrophage culture supernatants were significantly higher in two out of three trials. These findings suggest that the enhanced production of proinflammatory cytokine/metabolites by activated macrophages in PEMS poults may be responsible, at least in part, for the physiological intestinal inflammation, gut motility, and anorexia that characterize this disease.}, number={1}, journal={AVIAN DISEASES}, author={Heggen, CL and Qureshi, MA and Edens, FW and Barnes, HJ}, year={2000}, pages={59–65} }
 @article{breslin_smith_barnes_guy_2000, title={Comparison of virus isolation, immunohistochemistry, and reverse transcriptase-polymerase chain reaction procedures for detection of turkey coronavirus}, volume={44}, ISSN={["1938-4351"]}, DOI={10.2307/1593102}, abstractNote={A reverse transcriptase-polymerase chain reaction (RT-PCR) procedure and two monoclonal antibody (MAb)-based immunohistochemical procedures were developed for detection of turkey coronavirus (TCV) in tissues and intestinal contents/dropping samples. The RT-PCR, MAb-based fluorescent antibody (FA), and MAb-based immunoperoxidase (IP) procedures were compared with virus isolation (VI) for detection of TCV in experimentally infected turkeys. TCV was detected in experimentally infected turkeys as early as day 1 postexposure (PE) by each of the four detection procedures. TCV was detected as late as day 35 PE by FA or IP and days 42 and 49 PE by VI and RT-PCR, respectively. With VI as a reference, sensitivity and specificity of RT-PCR were 93% and 92%, respectively; specificity of both FA and IP was 96%, and sensitivities were 69% and 61%, respectively. Each of the examined procedures was highly specific, but the RT-PCR procedure was also highly sensitive. These findings demonstrate the utility of both immunohistochemistry and RT-PCR for detection of TCV. In addition, the findings indicate that RT-PCR is a highly sensitive and specific alternative to conventional diagnostic procedures.}, number={3}, journal={AVIAN DISEASES}, author={Breslin, JJ and Smith, LG and Barnes, HJ and Guy, JS}, year={2000}, pages={624–631} }
 @article{guy_smith_breslin_vaillancourt_barnes_2000, title={High mortality and growth depression experimentally produced in young turkeys by dual infection with enteropathogenic Escherichia coli and turkey coronavirus}, volume={44}, ISSN={["0005-2086"]}, DOI={10.2307/1592513}, abstractNote={Six-day-old turkeys were inoculated with turkey coronavirus (TCV) and an enteropathogenic Escherichia coli (EPEC) (isolate R98/5) that were isolated from poult enteritis and mortality syndrome (PEMS)-affected turkeys. Turkeys inoculated with only R98/5 did not develop clinically apparent disease, and only mild disease and moderate growth depression were observed in turkeys inoculated with only TCV. Turkeys dually inoculated with TCV and R98/5 developed severe enteritis with high mortality (38/48, 79%) and marked growth depression. R98/5 infection resulted in attaching/effacing (AE) intestinal lesions characteristic of EPEC: adherence of bacterial microcolonies to intestinal epithelium with degeneration and necrosis of epithelium at sites of bacterial attachment. AE lesions were more extensive and were detected for a prolonged duration in dually inoculated turkeys compared with turkeys inoculated with only R98/5. An apparent synergistic effect in dually inoculated turkeys was indicated by increased mortality, enhanced growth depression, and enhanced AE lesion development. The results suggest that TCV promoted intestinal colonization by R98/5; however, R98/5 did not appear to alter TCV infection. The present study provides a possible etiologic explanation for PEMS.}, number={1}, journal={AVIAN DISEASES}, author={Guy, JS and Smith, LG and Breslin, JJ and Vaillancourt, JP and Barnes, HJ}, year={2000}, pages={105–113} }
 @article{schultz-cherry_kapczynski_simmons_koci_brown_barnes_2000, title={Identifying agent(s) associated. with poult enteritis mortality syndrome: Importance of the thymus}, volume={44}, ISSN={["0005-2086"]}, DOI={10.2307/1592538}, abstractNote={Poult enteritis mortality syndrome (PEMS), a highly infectious disease of young turkeys, causes serious financial losses to the turkey industry. Clinically, PEMS is defined by mortality profiles, diarrhea, growth depression, and immunosuppression. Although many viruses, bacteria, and parasites are found in PEMS-infected birds, the inciting agent remains unknown. Experimentally, PEMS can be reproduced by exposing naïve poults to the intestinal contents from infected birds. Previous reports suggest that extraintestinal tissues fail to reproduce the disease. Histopathologic examination of tissues from PEMS-infected poults suggested that the thymus exhibited the earliest signs of pathology. On the basis of these observations, we hypothesized that the thymus harbors an agent(s) involved in PEMS. In these studies, naïve turkey poults were orally inoculated with a bacteria-free filtrate composed of either the intestines and feces or the thymus from PEMS-infected birds and were monitored for clinical signs of PEMS. Poults exposed to a filtrate composed solely of the thymus from PEMS-infected birds exhibited diarrhea, growth depression, mortality, pathology, and, most importantly, immunosuppression similar to poults exposed to the intestinal filtrate. The results of this study suggest that the thymus of infected birds harbors the agent(s) that can reproduce a PEMS-like disease in turkey poults.}, number={2}, journal={AVIAN DISEASES}, publisher={JSTOR}, author={Schultz-Cherry, S and Kapczynski, DR and Simmons, VM and Koci, MD and Brown, C and Barnes, HJ}, year={2000}, pages={256–265} }
 @misc{barnes_guy_vaillancourt_2000, title={Poult enteritis complex}, volume={19}, ISSN={["0253-1933"]}, DOI={10.20506/rst.19.2.1234}, abstractNote={Poult enteritis complex (PEC) is a general term that encompasses the infectious intestinal diseases of young turkeys. Some diseases, such as coronaviral enteritis and stunting syndrome, are relatively well characterised, while others, such as transmissible viral enteritis, poult growth depression and poult enteritis mortality syndrome, remain ill-defined. All forms of PEC are multifactorial, transmissible and infectious. Salient clinical features include stunting and poor feed utilisation that result from enteritis. In the more severe forms, runting, immune dysfunction and mortality are reported. Gross and microscopic lesions of enteritis are present in all forms but tend to be non-specific. Other lesions may be present, depending on the agents involved. The basic pathogenesis involves the following: a) alteration of the intestinal mucosa, generally by one or more viruses infecting enterocytes; b) inflammation; c) proliferation of secondary agents, usually bacteria. Non-infectious factors interplay with infectious agents to modulate the course and severity of disease. Diarrhoea is believed to be primarily osmotic because of maldigestion and malabsorption, but may also have a secretory component. Transmission is primarily faecal-oral. No public health significance is recognised or suspected. Prevention is based on eliminating the infectious agents from contaminated premises and preventing introduction into flocks. This is accomplished by an effective cleaning, disinfection and biosecurity programme. All-in/all-out production or separate brooding and finishing units are helpful. Control may require regional co-ordination among all companies producing turkeys, especially if the production is highly concentrated, and a quarantine programme for more severe forms of PEC. No vaccines or specific measures for controlling the organisms involved in PEC are available. Treatment is supportive for the viral component, while antibiotics, especially those with efficacy against Gram positive bacteria, may help to reduce the impact to bacterial infections. Evidence suggests that PEC occurs wherever turkeys are raised commercially, but this is not well documented and distribution of the various organisms that have been associated with PEC is largely unknown. The disease causes enormous economic loss, mostly from failure of the turkey to reach its genetic potential.}, number={2}, journal={REVUE SCIENTIFIQUE ET TECHNIQUE-OFFICE INTERNATIONAL DES EPIZOOTIES}, author={Barnes, HJ and Guy, JS and Vaillancourt, JP}, year={2000}, month={Aug}, pages={565–588} }
 @article{de buysscher_tonkonogy_vaillancourt_barnes_2000, title={Quantitation of thymic and bursal lymphocytes populations in normal and PEMS affected turkeys}, volume={49}, number={2000}, journal={Proceedings of the ... Western Poultry Disease Conference}, author={De Buysscher, E.V. and Tonkonogy, S. and Vaillancourt, J.P. and Barnes, H.J.}, year={2000}, pages={95–97} }
 @article{carver_fetrow_gerig_correa_krueger_barnes_2000, title={Use of statistical modeling to assess risk for early poult mortality in commercial turkey flocks}, volume={9}, DOI={10.1093/japr/9.3.303}, abstractNote={Abstract Statistical models were used to identify and quantify risk factors associated with early poult mortality. Mortality patterns were not different for hen and tom flocks, although toms experienced greater mortality. Season of placement, breeder flock age, strain, hatchery, and company had significant effects on risk of poult mortality in the first 14 days after placement. Hen flocks hatched in Virginia or placed in summer had higher risks of mortality. Tom flocks from young breeder hens, hatched in Virginia, or placed in winter had higher risks of mortality. There were strain effects on risk for poult mortality, and effect of breeder flock age on poult mortality was strain specific for hen poults. Median mortality differences among companies ranged from 0.98 to 2.11% at Day 14 for hens, and from 1.27 to 5.76% at Day 14 for toms. There were wide-ranging company effects on risks of mortality.}, number={3}, journal={Journal of Applied Poultry Research}, author={Carver, D. K. and Fetrow, J. and Gerig, T. and Correa, M. T. and Krueger, K. K. and Barnes, H. J.}, year={2000}, pages={303–318} }
 @article{yu_ismail_qureshi_dearth_barnes_saif_2000, title={Viral agents associated with poult enteritis and mortality syndrome: The role of a small round virus and a turkey coronavirus}, volume={44}, ISSN={["0005-2086"]}, DOI={10.2307/1592543}, abstractNote={Intestinal samples from turkey poults affected with poult enteritis and mortality syndrome (PEMS) were examined for viruses by immune electron microscopy and double-stranded RNA virus genome electropherotyping. Turkey coronavirus (TCV), avian rotaviruses, reovirus, and a yet undefined small round virus (SRV) were detected. The SRV and TCV were isolated and propagated in turkey embryos. Challenge of specific-pathogen-free turkey poults with SRV, TCV, or both resulted in mortality and clinical responses similar to those of natural PEMS. Our experiments indicate that SRV and TCV are possibly important agents in the etiology of PEMS and the combination of these infections might result in outbreaks with high mortality. The severity of clinical signs and mortality of PEMS are postulated to be partly related to the virus agents involved in individual outbreaks.}, number={2}, journal={AVIAN DISEASES}, author={Yu, M and Ismail, MM and Qureshi, MA and Dearth, RN and Barnes, HJ and Saif, YM}, year={2000}, pages={297–304} }
 @article{heggen_qureshi_edens_barnes_havenstein_1998, title={Alterations in the lymphocytic and mononuclear phagocytic systems of turkey poults associated with exposure to poult enteritis and mortality syndrome}, volume={42}, ISSN={["1938-4351"]}, DOI={10.2307/1592706}, abstractNote={In vivo and in vitro mononuclear phagocytic system functions, expression of lymphocyte subset cell surface markers in the thymus and bursa of Fabricius, and lymphocyte subset dynamics during the course of poult enteritis and mortality syndrome (PEMS) were examined. PEMS is an acute, transmissible, infectious intestinal disease accompanied by high mortality and morbidity. The etiology of this multifactorial disease remains to be elucidated; however, turkey coronavirus was initially assumed to be one of the primary agents involved. Further investigation demonstrated that turkey coronavirus was not always detectable in poults exhibiting PEMS symptoms, and, thus, PEMS poults began to be identified as positive or negative for turkey coronavirus. In each trial, uninfected hatchmate controls were compared with turkey poults that were contact exposed to PEMS poults at 7 days of age. Following intravenous inoculation, control poults cleared Escherichia coli from their circulation by 60 min, whereas viable E. coli were still present in the circulation of PEMS poults at 60 min postinoculation. Inflammatory response measured by Sephadex-elicited abdominal exudate cell recruitment and the adherence potential of abdominal exudate cells was not significantly different between uninfected and PEMS poults. The percentage of glass-adherent abdominal exudate macrophages was higher in PEMS poults. However, the ability of these macrophages to phagocytize sheep red blood cells and the average number of sheep red blood cells per phagocytic macrophage were both lower compared with uninfected controls. CD4+ expression in thymic tissue of PEMS poults at 9 days postinfection was significantly lower. The CD4+:CD8+ lymphocyte ratio in peripheral blood leukocytes from coronavirus-negative PEMS poults was lower than that from both uninfected and coronavirus-positive PEMS poults at 14 days postinfection. In the spleen, the CD4+:CD8+ lymphocyte ratio was higher in coronavirus-positive PEMS poults as compared with the other treatments. In conclusion, immune system dysfunction in PEMS is associated with impaired mononuclear phagocytic system function and alterations in lymphocyte populations.}, number={4}, journal={AVIAN DISEASES}, author={Heggen, CL and Qureshi, MA and Edens, FW and Barnes, HJ and Havenstein, GB}, year={1998}, pages={711–720} }
 @article{hawk_munger_barnes_1998, title={An outbreak of fatal disease in lovebirds attributed to an unidentified protozoan parasite}, volume={47}, number={1998}, journal={Proceedings of the ... Western Poultry Disease Conference}, author={Hawk, M. V. and Munger, L. L. and Barnes, H. J.}, year={1998}, pages={19–20} }
 @article{powers_merrill_degernes_miller_latimer_barnes_1998, title={Axillary cystadenocarcinoma in a Moluccan cockatoo (Cacatua moluccensis)}, volume={42}, ISSN={["0005-2086"]}, DOI={10.2307/1592495}, abstractNote={An adult Moluccan cockatoo (Cacatua moluccensis) was diagnosed with a cystadenocarcinoma in the right axillary region that was treated symptomatically with surgical debulking and periodic drainage. The bird eventually died and a necropsy was performed. The neoplasm extended through the humerus, and small neoplastic foci were seen within the ipsilateral lung parenchyma. Rare groupings of microvilli were observed lining intercellular canalicular lumens on electron microscopy within the axillary tumor. These findings suggest a respiratory neoplasm, although the tissue of origin remained undetermined.}, number={2}, journal={AVIAN DISEASES}, author={Powers, LV and Merrill, CL and Degernes, LA and Miller, R and Latimer, KS and Barnes, HJ}, year={1998}, pages={408–412} }
 @article{temple_weiss_walker_barnes_christensen_miyamoto_shelton_orndorff_1998, title={Bordetella avium virulence measured in vivo and in vitro}, volume={66}, number={11}, journal={Infection and Immunity}, author={Temple, L. M. and Weiss, A. A. and Walker, K. E. and Barnes, H. J. and Christensen, V. L. and Miyamoto, D. M. and Shelton, C. B. and Orndorff, P. E.}, year={1998}, pages={5244–5251} }
 @article{vukina_barnes_solakoglu_1998, title={Intervention decision model to prevent spiking mortality of turkeys}, volume={77}, ISSN={["0032-5791"]}, DOI={10.1093/ps/77.7.950}, abstractNote={
 Abstract
 
 Based on the daily records on turkeys' mortalities for the series of flocks placed on different farms in a relatively compact geographical area for the period of approximately 2 yr and other relevant explanatory variables, the goal of the research was to design a decision model to determine whether or not to use the fluorquinolone antibiotic, sarafloxacin, to prevent spiking mortality of turkeys. The core of the designed decision model is the forecasting model that attempts to ex-ante predict the cumulative flock mortality for the period between 8 and 28 d of age. Forecasts were generated with the parameters of the linear regression model where continuous values of daily mortalities served as a dependent variable. The decision variable is a binary (yes/no) choice variable, where “yes” means “go ahead with treatment” and “no” means “do nothing”. If the predicted cumulative mortality for the period between 8 and 28 d of age exceeds 9% of the total initial placement, the model generates a “yes” signal. If the predicted cumulative mortality for the same period is below 9% of the total initial placement, the model generates a “no” signal. The results indicate a reasonable accuracy of the prediction model where the number of correct prediction increases and the number of incorrect predictions falls very fast as the forecasting window shortens. The intervention decision model could help veterinarians in making decisions on whether or not to treat the suspect flocks.
 
}, number={7}, journal={POULTRY SCIENCE}, author={Vukina, T and Barnes, HJ and Solakoglu, MN}, year={1998}, month={Jul}, pages={950–955} }
 @article{barnes_1998, title={Role of the pathologist in poultry disease diagnosis}, volume={47}, number={1998}, journal={Proceedings of the ... Western Poultry Disease Conference}, author={Barnes, H. J.}, year={1998}, pages={2–3} }
 @article{barnes_guy_1998, title={Update on poult enteritis mortality syndrome, 1997}, volume={47}, number={1998}, journal={Proceedings of the ... Western Poultry Disease Conference}, author={Barnes, H. J. and Guy, J. S.}, year={1998}, pages={39–42} }
 @article{guy_barnes_smith_breslin_1997, title={Antigenic characterization of a turkey coronavirus identified in poult enteritis- and mortality syndrome-affected turkeys}, volume={41}, ISSN={["1938-4351"]}, DOI={10.2307/1592148}, abstractNote={A turkey coronavirus (TCV [NC95]) was characterized by antigenic comparison with other avian and mammalian coronaviruses using immunofluorescence (FA) and immunoperoxidase (IP) procedures. Based on FA and IP procedures, TCV (NC95) was determined to be antigenically indistinguishable from turkey enteric (bluecomb) coronavirus (TECV). In addition, TCV (NC95) and TECV were found to be closely related to infectious bronchitis virus (IBV); a one-way antigenic relationship was demonstrated. Polyclonal antibodies specific for TECV and IBV reacted strongly against TCV (NC95), as determined by FA procedures. Monoclonal antibodies (MAbs) specific for IBV matrix protein (MAb 919) reacted strongly against TCV (NC95) and TECV as determined by FA and IP procedures; an IBV peplomer protein-specific MAb (MAb 94) did not recognize the two viruses. These studies suggest an identification of TCV (NC95) as a strain of TECV, and provide evidence of a close antigenic relationship between these viruses and IBV.}, number={3}, journal={AVIAN DISEASES}, author={Guy, JS and Barnes, HJ and Smith, LG and Breslin, J}, year={1997}, pages={583–590} }
 @article{guy_barnes_1997, title={Characterization of an avian adenovirus associated with inclusion body hepatitis in day-old turkeys}, volume={41}, ISSN={["0005-2086"]}, DOI={10.2307/1592167}, abstractNote={A group I avian adenovirus isolated from day-old turkeys with inclusion body hepatitis (IBH) was identified as turkey adenovirus serotype 2 (TAV2) based on cross-neutralization assays and DNA restriction endonuclease analyses. Yolk sac inoculation of embryonated turkey eggs resulted in embryo mortality and significantly (P < 0.01) decreased hatchability compared with sham-inoculated controls. Embryo mortality occurred primarily between day 24 of incubation and the time embryos hatched. Focal necrosis was detected in livers of 11/52 virus-inoculated embryos that died postinoculation and 1/27 hatchlings; in three embryos, areas of necrosis contained intranuclear inclusion bodies. These findings identify the IBH isolate as TAV2, incriminate the virus as a potential cause of suboptimal hatchability in turkeys, and provide additional evidence for causal involvement in IBH.}, number={3}, journal={AVIAN DISEASES}, author={Guy, JS and Barnes, HJ}, year={1997}, pages={726–731} }
 @article{barnes_1997, title={Prevention, control and treatment of poult enteritis-mortality syndrome}, volume={56}, number={5}, journal={Poultry Digest}, author={Barnes, H. J.}, year={1997}, pages={16} }
 @article{ley_mclaren_miles_barnes_miller_franz_1997, title={Transmissibility of live Mycoplasma gallisepticum vaccine strains ts-11 and 6/85 from vaccinated layer pullets to sentinel poultry}, volume={41}, ISSN={["0005-2086"]}, DOI={10.2307/1592459}, abstractNote={In separate trials, layer pullets were vaccinated with Mycoplasma gallisepticum (MG) strain 6/85 or strain ts-11 commercially produced live vaccines. For a 15-wk postvaccination (PV) period, vaccinates were commingled with unvaccinated pullets and were in indirect contact with sentinel groups of pullets, broiler breeders, turkey breeders, or meat turkeys in adjoining pens. Infectivity and transmissibility of vaccine strains were determined by tracheal culture and serology at 1 wk followed by 3-wk intervals PV. Strain 6/85 was recovered from 0%-20% of vaccinates, but not from commingled pullets or sentinel birds. Strain ts-11 was recovered from 60%-90% of vaccinates and 0%-40% of commingled pullets but not from any of the sentinel birds. No birds in the 6/85 vaccine trial tested positive for MG antibodies by serology. MG enzyme-linked immunosorbent assays detected positive responses in ts-11 vaccinates (range = 10%-70%) at 42, 63, 84, and 105 days PV, and commingled pullets (10%) at 84 and 105 days PV. MG serum plate agglutination tests detected positive responses in 90% and 20% of ts-11 vaccinates at 42 and 105 days PV, respectively, and commingled pullets (10%) at day 42 PV. Clinical signs, morbidity, or mortality suggestive of pathogenic MG infection were not observed in any bird during either trial, and no gross lesions were observed at necropsy. Random amplified polymorphic DNA analysis was capable of distinguishing each of the vaccinal strains 6/85 and ts-11 from each other by their distinct DNA banding patterns.}, number={1}, journal={AVIAN DISEASES}, author={Ley, DH and McLaren, JM and Miles, AM and Barnes, HJ and Miller, SH and Franz, G}, year={1997}, pages={187–194} }
 @inproceedings{degernes_davidson_barnes_whitt_1995, title={A preliminary report on intraosseous total parenteral nutrition in birds.}, booktitle={Proceedings Annual Conference of the Association of Avian Veterinarians}, author={Degernes, L. A. and Davidson, G. F. and Barnes, H. J. and Whitt, D.}, year={1995}, pages={25–26} }
 @article{barnes_1994, title={Alphavirus infections of turkeys}, volume={42}, number={1}, journal={Turkeys}, author={Barnes, H. J.}, year={1994}, pages={26} }