@article{gensler_hempstead_keelara_fedorka-cray_urie_wiedenheft_stuart_marshall_jacob_2024, title={Antimicrobial Resistance Characteristics of Fecal <i>Escherichia coli</i> and <i>Enterococcus</i> Species in US Goats: 2019 National Animal Health Monitoring System Enteric Study}, ISSN={["1556-7125"]}, DOI={10.1089/fpd.2023.0089}, abstractNote={Escherichia coli and Enterococcus species are normal bacteria of the gastrointestinal tract and serve as indicator organisms for the epidemiology and emergence of antimicrobial resistance in their hosts and the environment. Some E. coli serovars, including E. coli O157:H7, are important human pathogens, although reservoir species such as goats remain asymptomatic. We describe the prevalence and antimicrobial resistance of generic E. coli, E. coli O157:H7, and Enterococcus species collected from a national surveillance study of goat feces as part of the National Animal Health Monitoring System (NAHMS) Goat 2019 study. Fecal samples were collected from 4918 goats on 332 operations across the United States. Expectedly, a high prevalence of E. coli (98.7%, 4850/4915) and Enterococcus species (94.8%, 4662/4918) was found. E. coli O157:H7 prevalence was low (0.2%; 10/4918). E. coli isolates, up to three per operation, were evaluated for antimicrobial susceptibility and 84.7% (571/674) were pansusceptible. Multidrug resistance (MDR; ≥3 classes) was uncommon among E. coli, occurring in 8.2% of isolates (55/674). Resistance toward seven antimicrobial classes was observed in a single isolate. Resistance to tetracycline alone (13.6%, 92/674) or to tetracycline, streptomycin, and sulfisoxazole (7.0% 47/674) was the most common pattern. All E. coli O157:H7 isolates were pansusceptible. Enterococcus isolates, up to four per operation, were prioritized by public health importance, including Enterococcus faecium and Enterococcus faecalis and evaluated. Resistance to lincomycin (93.8%, 1232/1313) was most common, with MDR detected in 29.5% (388/1313) of isolates. The combination of ciprofloxacin, lincomycin, and quinupristin resistance (27.1%, 105/388) was the most common pattern detected. Distribution and characteristics of antimicrobial resistance in E. coli and Enterococcus in the U.S. goat population from this study can inform stewardship considerations and public health efforts surrounding goats and their products.}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Gensler, Catherine A. and Hempstead, Stephanie C. and Keelara, Shivaramu and Fedorka-Cray, Paula J. and Urie, Natalie J. and Wiedenheft, Alyson M. and Stuart, Keira and Marshall, Katherine L. and Jacob, Megan E.}, year={2024}, month={Mar} }
 @article{aworh_thakur_gensler_harrell_harden_fedorka-cray_jacob_2024, title={Characteristics of antimicrobial resistance in <i>Escherichia coli</i> isolated from retail meat products in North Carolina}, volume={19}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0294099}, abstractNote={
Background
Escherichia coli is commonly used as an indicator for antimicrobial resistance (AMR) in food, animal, environment, and human surveillance systems. Our study aimed to characterize AMR in E. coli isolated from retail meat purchased from grocery stores in North Carolina, USA as part of the National Antimicrobial Resistance Monitoring System (NARMS).
}, number={1}, journal={PLOS ONE}, author={Aworh, Mabel Kamweli and Thakur, Siddhartha and Gensler, Catherine and Harrell, Erin and Harden, Lyndy and Fedorka-Cray, Paula J. and Jacob, Megan}, year={2024}, month={Jan} }
 @article{didomenico_jacob_stowe_gruber_2024, title={Diagnostic utility of the total nucleated cell count for differentiation of septic and sterile peritoneal effusions in dogs}, volume={2}, ISSN={["1939-165X"]}, url={https://doi.org/10.1111/vcp.13315}, DOI={10.1111/vcp.13315}, abstractNote={Abstract}, journal={VETERINARY CLINICAL PATHOLOGY}, author={Didomenico, Amy E. and Jacob, Megan E. and Stowe, Devorah M. and Gruber, Erika J.}, year={2024}, month={Feb} }
 @article{halleran_sylvester_jacob_callahan_baynes_foster_2024, title={Impact of florfenicol dosing regimen on the phenotypic and genotypic resistance of enteric bacteria in steers}, volume={14}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-024-55591-8}, abstractNote={Abstract}, number={1}, journal={SCIENTIFIC REPORTS}, author={Halleran, Jennifer and Sylvester, Hannah and Jacob, Megan and Callahan, Benjamin and Baynes, Ronald and Foster, Derek}, year={2024}, month={Feb} }
 @article{abdelrahim_harrell_fedorka-cray_jacob_thakur_2024, title={Phenotypic and Genotypic Characterizations of Antimicrobial-Resistant <i>Escherichia coli</i> Isolates from Diverse Retail Meat Samples in North Carolina During 2018-2019}, volume={1}, ISSN={["1556-7125"]}, DOI={10.1089/fpd.2023.0093}, abstractNote={Surveillance of antimicrobial-resistant pathogens in U.S. retail meats is conducted to identify potential risks of foodborne illness. In this study, we conducted a phenotypic and genotypic analysis of Escherichia coli recovered from a diverse range of retail meat types during 2018-2019 in North Carolina. The investigation was conducted as part of the National Antimicrobial Resistance Monitoring System (NARMS). Retail meat sampling and E. coli isolation were performed in accordance with NARMS retail meat isolation protocols. We used the Sensititre™ broth microdilution system to determine phenotypic resistance to 14 antimicrobial agents and the Illumina next-generation sequencing platform for genotypic resistance profiling. The highest prevalence of E. coli isolates was found in ground turkey (n = 57, 42.9%) and chicken (n = 27, 20.3%), followed by ground beef (n = 25, 18.9%) and pork (n = 24, 18%). The isolates were divided into seven different phylogroups using the Clermont typing tool, with B1 (n = 59, 44.4%) and A (n = 39, 29.3%) being the most dominant, followed by B2 (n = 14, 10.5%), D (n = 7, 5.3%), F (n = 6, 4.5%), E (n = 3, 2.3%), and C (n = 2, 1.5%). Using multilocus sequence typing (MLST), 128 Sequence types (STs) were identified indicating high diversity. Phenotypic and genotypic resistance was observed toward aminoglycosides, sulfonamides, beta-lactams, macrolides, tetracyclines, phenicols, and fluoroquinolones. Ground turkey samples were more resistant to the panel of tested antimicrobials than chicken, beef, or pork (p < 0.05). All isolates were found to be susceptible to meropenem. A high percentage of turkey isolates (n = 16, 28%) were multidrug-resistant (MDR) compared with 18.5% of chicken (n = 5), 8.4% of pork (n = 2), and 8% of beef isolates (n = 2). This study highlights the benefit of surveillance to identify MDR E. coli for epidemiologic tracking and is a comprehensive report of the phenotypic and genotypic characterization of E. coli isolated from retail meats in North Carolina.}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Abdelrahim, Afaf and Harrell, Erin and Fedorka-Cray, Paula J. and Jacob, Megan and Thakur, Siddhartha}, year={2024}, month={Jan} }
 @article{dietrich_lecuyer_hendrix_burbick_jacob_byrne_olsen_mitchell_ceric_lin_et al._2024, title={Prevalence and molecular epidemiology of carbapenemase-producing Enterobacterales isolated from dog and cat faeces submitted to veterinary laboratories in the USA}, ISSN={["1863-2378"]}, DOI={10.1111/zph.13144}, abstractNote={To estimate the prevalence of carbapenemase-producing Enterobacterales (CPE) carriage among pets using faecal specimens submitted to veterinary diagnostic laboratories throughout the US. A secondary aim was to employ whole-genome sequencing (WGS) to characterize isolates of CPE from companion animals and compare them to publicly available CPE genomes.}, journal={ZOONOSES AND PUBLIC HEALTH}, author={Dietrich, Jaclyn and Lecuyer, Tessa E. and Hendrix, G. Kenitra and Burbick, Claire R. and Jacob, Megan E. and Byrne, Barbara A. and Olsen, Karen and Mitchell, Maria and Ceric, Olgica and Lin, Rachel and et al.}, year={2024}, month={May} }
 @article{gensler_hempstead_keelara_fedorka-cray_urie_wiedenheft_marshall_branan_stuart_lantz_et al._2024, title={Prevalence, Antimicrobial Resistance, and Diversity of <i>Campylobacter</i> Isolated from US Goat Feces: 2019 NAHMS Survey}, ISSN={["1556-7125"]}, DOI={10.1089/fpd.2023.0080}, abstractNote={Goats are often asymptomatic carriers of}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Gensler, Catherine A. and Hempstead, Stephanie C. and Keelara, Shivaramu and Fedorka-Cray, Paula J. and Urie, Natalie J. and Wiedenheft, Alyson M. and Marshall, Katherine L. and Branan, Matthew and Stuart, Kiera and Lantz, Kristina and et al.}, year={2024}, month={Jul} }
 @article{wallace_love_gensler_jacob_robertson_messenger_2023, title={Comparative growth dynamics of bacterial and fungal contaminants in bupivacaine liposomal injectable suspension, bupivacaine 0.5%, and propofol}, volume={18}, ISSN={["1932-6203"]}, url={https://doi.org/10.1371/journal.pone.0281768}, DOI={10.1371/journal.pone.0281768}, abstractNote={
Objective
To determine whether bupivacaine liposomal injectable suspension (BLIS) supports microbial growth when artificially inoculated and to evaluate liposomal stability in the face of this extrinsic contamination as evidenced by changes in free bupivacaine concentrations.
}, number={2}, journal={PLOS ONE}, author={Wallace, Amber and Love, Lydia and Gensler, Catherine and Jacob, Megan and Robertson, James and Messenger, Kristen}, editor={Nevárez-Moorillón, Guadalupe VirginiaEditor}, year={2023}, month={Feb} }
 @article{walker_harden_suyemoto_thakur_jacob_borst_2023, title={Draft Genome Sequences of Escherichia coli and Enterococcus faecalis Coisolated from Polymicrobial Extraintestinal Infections of Chickens and Turkeys}, volume={2}, ISSN={["2576-098X"]}, DOI={10.1128/mra.01163-22}, abstractNote={
            Coinfections by avian pathogenic
            Escherichia coli
            (APEC) and
            Enterococcus faecalis
            in poultry with colisepticemia have become increasingly recognized. Here, we report draft genome sequences of 18 APEC and 18
            E. faecalis
            strains coisolated from lesions of diseased poultry.
          }, journal={MICROBIOLOGY RESOURCE ANNOUNCEMENTS}, author={Walker, Grayson K. and Harden, Lyndy and Suyemoto, M. Mitsu and Thakur, Siddhartha and Jacob, Megan and Borst, Luke B.}, year={2023}, month={Feb} }
 @article{walker_harden_suyemoto_thakur_jacob_borst_2023, title={Draft genome sequences of 12 Escherichia coli co-isolated with Enterococcus spp. from dogs with polybacterial bacteriuria at a veterinary hospital}, volume={8}, ISSN={["2576-098X"]}, DOI={10.1128/MRA.00262-23}, abstractNote={ABSTRACT}, journal={MICROBIOLOGY RESOURCE ANNOUNCEMENTS}, author={Walker, Grayson K. and Harden, Lyndy and Suyemoto, M. Mitsu and Thakur, Siddhartha and Jacob, Megan and Borst, Luke B.}, year={2023}, month={Aug} }
 @article{gookin_hartley_aicher_mathews_cullen_cullen_callahan_stowe_seiler_jacob_et al._2023, title={Gallbladder microbiota in healthy dogs and dogs with mucocele formation}, volume={18}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0281432}, abstractNote={To date studies have not investigated the culture-independent microbiome of bile from dogs, a species where aseptic collection of bile under ultrasound guidance is somewhat routine. Despite frequent collection of bile for culture-based diagnosis of bacterial cholecystitis, it is unknown whether bile from healthy dogs harbors uncultivable bacteria or a core microbiota. The answer to this question is critical to understanding the pathogenesis of biliary infection and as a baseline to exploration of other biliary diseases in dogs where uncultivable bacteria could play a pathogenic role. A pressing example of such a disease would be gallbladder mucocele formation in dogs. This prevalent and deadly condition is characterized by excessive secretion of abnormal mucus by the gallbladder epithelium that can eventually lead to rupture of the gallbladder or obstruction of bile flow. The cause of mucocele formation is unknown as is whether uncultivable, and therefore unrecognized, bacteria play any systematic role in pathogenesis. In this study we applied next-generation 16S rRNA gene sequencing to identify the culture-negative bacterial community of gallbladder bile from healthy dogs and gallbladder mucus from dogs with mucocele formation. Integral to our study was the use of 2 separate DNA isolations on each sample using different extraction methods and sequencing of negative control samples enabling recognition and curation of contaminating sequences. Microbiota findings were validated by simultaneous culture-based identification, cytological examination of bile, and fluorescence in-situ hybridization (FISH) performed on gallbladder mucosa. Using culture-dependent, cytological, FISH, and 16S rRNA sequencing approaches, results of our study do not support existence of a core microbiome in the bile of healthy dogs or gallbladder mucus from dogs with mucocele formation. Our findings further document how contaminating sequences can significantly contribute to the results of sequencing analysis when performed on samples with low bacterial biomass.}, number={2}, journal={PLOS ONE}, author={Gookin, Jody L. and Hartley, Ashley N. and Aicher, Kathleen M. and Mathews, Kyle G. and Cullen, Rachel and Cullen, John M. and Callahan, Benjamin J. and Stowe, Devorah M. and Seiler, Gabriela S. and Jacob, Megan E. and et al.}, year={2023}, month={Feb} }
 @article{slead_callahan_schreeg_seiler_stowe_azcarate-peril_jacob_gookin_2023, title={Microbiome analysis of bile from apparently healthy cats and cats with suspected hepatobiliary disease}, volume={9}, ISSN={["1939-1676"]}, url={https://doi.org/10.1111/jvim.16852}, DOI={10.1111/jvim.16852}, abstractNote={Abstract}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={Slead, Tanner S. and Callahan, Benjamin J. and Schreeg, Megan E. and Seiler, Gabriela S. and Stowe, Devorah M. and Azcarate-Peril, Maria Andrea and Jacob, Megan E. and Gookin, Jody L.}, year={2023}, month={Sep} }
 @article{rhea_gensler_atlaw_pairis-garcia_lewbart_valentine_cruz_castillo_velez_trueba_et al._2023, title={Presence of Extended-Spectrum Beta-Lactamase-Producing <i>Escherichia coli</i> in Food-Producing and Companion Animals and Wildlife on Small-Holder Farms of Floreana Island, Galapagos Islands}, volume={11}, ISSN={["1557-7759"]}, url={https://doi.org/10.1089/vbz.2023.0044}, DOI={10.1089/vbz.2023.0044}, abstractNote={Background: Antimicrobial resistance (AR) has led to increasing human and animal morbidity and mortality and negative consequences for the environment. AR among Escherichia coli (EC) is on the rise, with serious concerns about extended-spectrum β-lactamase-producing E. coli (ESBL-EC). In the Galápagos Islands, where antimicrobials are available without a prescription, growing demands for food production can drive antimicrobial use. Food producing animals are at the interface of wildlife and environmental health on the smallest human-inhabited Galápagos Island, Floreana. We sought to determine if ESBL-EC were present in Floreana Island farm animal species and nearby wildlife and the relatedness of ESBL-EC isolates identified. Materials and Methods: During July 4-5, 2022, we visited 8 multispecies farms, representing 75% of food-producing animal production on Floreana, and collected 227 fecal samples from farm animals and wildlife. Each sample was plated on MacConkey agar supplemented with cefotaxime (4 μg/mL). Results: ESBL-EC was isolated from 20 (9%) fecal samples collected from pigs (N = 10), chickens (N = 6), wildlife (N = 3), and dog (N = 1). All ESBL-EC isolates were from samples taken at three (38%) of the eight farms. Fifteen (75%) of the ESBL-EC isolates were from a single farm. All ESBL-EC isolates were multidrug resistant. The most prevalent ESBL genes belonged to the blaCTX-M group. Among the typeable isolates from the farm with the largest proportion of ESBL-EC isolates (N = 14), we observed nine unique pulsed-field gel electrophoresis (PFGE) patterns, with identical patterns present across pig and chicken isolates. PFGE patterns in the three farms with ESBL-EC isolates were different. Conclusions: These results lend support for future routine AR monitoring activities at the livestock-wildlife interface in Galápagos to characterize potential interspecies transmission of AR bacteria and AR genes in this unique protected ecosystem, and the related human, animal, and environmental health impacts, and to formulate interventions to reduce AR spread in this setting.}, journal={VECTOR-BORNE AND ZOONOTIC DISEASES}, author={Rhea, Sarah and Gensler, Catherine and Atlaw, Nigatu and Pairis-Garcia, Monique and Lewbart, Gregory A. and Valentine, Alyssa and Cruz, Marilyn and Castillo, Paulina and Velez, Alberto and Trueba, Gabriel and et al.}, year={2023}, month={Nov} }
 @article{berg_jacob_mamo_pluta_lunn_2023, title={Refrigerated multi-dose insulin vials remain sterile through 6 months of use}, volume={8}, ISSN={["1748-5827"]}, url={https://doi.org/10.1111/jsap.13664}, DOI={10.1111/jsap.13664}, abstractNote={ObjectivesTo evaluate sterility in refrigerated multi‐dose insulin vials through 6 months of routine aspiration.}, journal={JOURNAL OF SMALL ANIMAL PRACTICE}, author={Berg, A. S. and Jacob, M. E. and Mamo, L. B. and Pluta, D. H. and Lunn, K. F.}, year={2023}, month={Aug} }
 @article{lamontagne_christenson_rogers_jacob_stewart_2023, title={Relating Antimicrobial Resistance and Virulence in Surface-Water <i>E. coli</i>}, volume={11}, ISSN={["2076-2607"]}, DOI={10.3390/microorganisms11112647}, abstractNote={The role of the environment in the emergence and spread of antimicrobial resistance (AMR) is being increasingly recognized, raising questions about the public health risks associated with environmental AMR. Yet, little is known about pathogenicity among resistant bacteria in environmental systems. Existing studies on the association between AMR and virulence are contradictory, as fitness costs and genetic co-occurrence can be opposing influences. Using Escherichia coli isolated from surface waters in eastern North Carolina, we compared virulence gene prevalence between isolates resistant and susceptible to antibiotics. We also compared the prevalence of isolates from sub-watersheds with or without commercial hog operations (CHOs). Isolates that had previously been evaluated for phenotypic AMR were paired by matching isolates resistant to any tested antibiotic with fully susceptible isolates from the same sample date and site, forming 87 pairs. These 174 isolates were evaluated by conventional PCR for seven virulence genes (bfp, fimH, cnf-1, STa (estA), EAST-1 (astA), eae, and hlyA). One gene, fimH, was found in 93.1% of isolates. Excluding fimH, at least one virulence gene was detected in 24.7% of isolates. Significant negative associations were found between resistance to at least one antibiotic and presence of at least one virulence gene, tetracycline resistance and presence of a virulence gene, resistance and STa presence, and tetracycline resistance and STa presence. No significant associations were found between CHO presence and virulence, though some sub-significant associations merit further study. This work builds our understanding of factors controlling AMR dissemination through the environment and potential health risks.}, number={11}, journal={MICROORGANISMS}, author={LaMontagne, Connor D. and Christenson, Elizabeth C. and Rogers, Anna T. and Jacob, Megan E. and Stewart, Jill R.}, year={2023}, month={Nov} }
 @article{gilbertie_schaer_engiles_seiler_deddens_schubert_jacob_stefanovski_ruthel_hickok_et al._2022, title={A Platelet-Rich Plasma-Derived Biologic Clears Staphylococcus aureus Biofilms While Mitigating Cartilage Degeneration and Joint Inflammation in a Clinically Relevant Large Animal Infectious Arthritis Model}, volume={12}, ISSN={2235-2988}, url={http://dx.doi.org/10.3389/fcimb.2022.895022}, DOI={10.3389/fcimb.2022.895022}, abstractNote={The leading cause of treatment failure in Staphylococcus aureus infections is the development of biofilms. Biofilms are highly tolerant to conventional antibiotics which were developed against planktonic cells. Consequently, there is a lack of antibiofilm agents in the antibiotic development pipeline. To address this problem, we developed a platelet-rich plasma (PRP)-derived biologic, termed BIO-PLY (for the BIOactive fraction of Platelet-rich plasma LYsate) which has potent in vitro bactericidal activity against S. aureus synovial fluid free-floating biofilm aggregates. Additional in vitro studies using equine synoviocytes and chondrocytes showed that BIO-PLY protected these cells of the joint from inflammation. The goal of this study was to test BIO-PLY for in vivo efficacy using an equine model of infectious arthritis. We found that horses experimentally infected with S. aureus and subsequently treated with BIO-PLY combined with the antibiotic amikacin (AMK) had decreased bacterial concentrations within both synovial fluid and synovial tissue and exhibited lower systemic and local inflammatory scores compared to horses treated with AMK alone. Most importantly, AMK+BIO-PLY treatment reduced the loss of infection-associated cartilage proteoglycan content in articular cartilage and decreased synovial tissue fibrosis and inflammation. Our results demonstrate the in vivo efficacy of AMK+BIO-PLY and represents a new approach to restore and potentiate antimicrobial activity against synovial fluid biofilms.}, journal={Frontiers in Cellular and Infection Microbiology}, publisher={Frontiers Media SA}, author={Gilbertie, Jessica M. and Schaer, Thomas P. and Engiles, Julie B. and Seiler, Gabriela S. and Deddens, Bennett L. and Schubert, Alicia G. and Jacob, Megan E. and Stefanovski, Darko and Ruthel, Gordon and Hickok, Noreen J. and et al.}, year={2022}, month={May} }
 @article{christenson_wickersham_jacob_stewart_2022, title={A watershed study assessing effects of commercial hog operations on microbial water quality in North Carolina, USA}, volume={838}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2022.156085}, abstractNote={Commercial Hog Operations (CHOs) produce large amounts of fecal waste, which is often treated in lagoons and sprayed onto fields as fertilizer. The effects of these systems on proximal water quality compared to ambient conditions have not been well-studied, and are particularly important for understanding the dissemination of fecal bacteria and antimicrobial resistance. A longitudinal, case-control watershed study was designed to study effects of CHOs on microbial water quality among watersheds with similar soil, land use, human population, and area. We compared watersheds with (n = 13) and without (n = 9) CHOs over one year measuring fecal indicator bacteria (FIB), microbial source tracking (MST) fecal markers, and antimicrobial resistance in isolated Escherichia coli. E. coli concentrations were higher (p < 0.001) at sites downstream of CHOs (1284 CFU/100 mL, n = 103) compared to background sites (687 CFU/100 mL, n = 74). The human MST marker HF183 was detected at similarly low concentrations (PR = 1.3 (0.91, 1.8), p = 0.30). However, the swine MST marker pig-2-bac was found at more sites downstream of CHOs (PR = 3.5 (0.98, 12), p = 0.035) and at a significantly higher (p = 0.003) mean concentration at sites downstream of CHOs (283 copies/mL) compared to background sites (0.76 copies/mL). The presence of any antimicrobial resistance was observed more often for E. coli isolated downstream from CHOs (19%, n = 556) than background sites (6%, n = 356), with tetracycline resistance observed most often. Nine isolates from four sites downstream of CHOs and one isolate from a background site were confirmed β-lactamase-producing E. coli. Overall, these results show that fecal microbes and antimicrobial resistance from CHOs may be transported off-site, however more research is needed to characterize timing and conditions of off-site transport. Mitigation strategies such as optimizeation of waste treatment, buffers, and antibiotic stewardship could help reduce the contributions of microbial contaminants to surface water.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Christenson, Elizabeth and Wickersham, Lindsay and Jacob, Megan and Stewart, Jill}, year={2022}, month={Sep} }
 @article{hempstead_gensler_keelara_brennan_urie_wiedenheft_marshall_morningstar-shaw_lantz_fedorka-cray_et al._2022, title={Detection and molecular characterization of Salmonella species on US goat operations}, volume={208}, ISSN={["1873-1716"]}, DOI={10.1016/j.prevetmed.2022.105766}, abstractNote={Salmonella species are an important cause of gastrointestinal disease in animals, including goats. Additionally, Salmonella species are among the top five U.S. foodborne pathogens causing illness to humans. The goat industry is rapidly expanding in the U.S. yet estimates of Salmonella prevalence within these populations is lacking. The aim of this study was to investigate the fecal prevalence, antimicrobial resistance (AMR), biofilm potential, and virulence profile of Salmonella species isolated from goat feces as part of the United States Department of Agriculture (USDA) National Animal Health Monitoring System (NAHMS) Goat 2019 study, enteric microbe component. A total of 4917 fecal samples were collected from 332 operations, from September 2019-March 2020. Salmonella were isolated using standard enrichment and culture methods; antimicrobial susceptibility was determined by broth microdilution. Biofilm production was assessed using a crystal violet assay and normalized to a positive control strain, and PCR was used to detect virulence genes. Overall, we detected a low prevalence (0.7%, n = 35/4917) of Salmonella in goat feces and identified a broad range of serotypes including S. Bareilly (35%) and a single rare S. Sharon. All isolates were pansusceptible to 14 antimicrobials except one, which was resistant to only tetracycline (MIC ≥ 32 µg/mL). All strains were found to possess the majority of virulence determinants screened, and 40% (14 of 35) formed weak, moderate, or strong biofilm. We found a low prevalence of Salmonella, and characteristics of Salmonella in the U.S. goat population informs ongoing public health efforts to manage risk of animal food products and animal interactions.}, journal={PREVENTIVE VETERINARY MEDICINE}, author={Hempstead, Stephanie C. and Gensler, Catherine A. and Keelara, Shivaramu and Brennan, Matthew and Urie, Natalie J. and Wiedenheft, Alyson M. and Marshall, Katherine L. and Morningstar-Shaw, Brenda and Lantz, Kristina and Fedorka-Cray, Paula J. and et al.}, year={2022}, month={Nov} }
 @article{walker_yustyniuk_shamoun_jacob_correa_vaden_borst_2022, title={Detection of Escherichia coli and Enterococcus spp. in dogs with polymicrobial urinary tract infections: A 5-year retrospective study}, volume={5}, ISSN={["1939-1676"]}, DOI={10.1111/jvim.16445}, abstractNote={Abstract}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={Walker, Grayson K. and Yustyniuk, Valeriia and Shamoun, John and Jacob, Megan E. and Correa, Maria and Vaden, Shelly L. and Borst, Luke B.}, year={2022}, month={May} }
 @misc{ruzante_harris_plummer_raineri_loy_jacob_sahin_kreuder_2022, title={Surveillance of antimicrobial resistance in veterinary medicine in the United States: Current efforts, challenges, and opportunities}, volume={9}, ISSN={["2297-1769"]}, DOI={10.3389/fvets.2022.1068406}, abstractNote={Antimicrobial resistance (AMR) is a global problem facing human, animal, plant, and environmental health by threatening our ability to effectively treat bacterial infections with antimicrobials. In the United States, robust surveillance efforts exist to collect, analyze, and disseminate AMR data in human health care settings. These tools enable the development of effective infection control methods, the detection of trends, and provide the evidence needed to guide stewardship efforts to reduce the potential for emergence and further spread of AMR. However, in veterinary medicine, there are currently no known equivalent tools. This paper reviews efforts in the United States related to surveillance of AMR in veterinary medicine and discusses the challenges and opportunities of using data from veterinary diagnostic laboratories to build a comprehensive AMR surveillance program that will support stewardship efforts and help control AMR in both humans and animals.}, journal={FRONTIERS IN VETERINARY SCIENCE}, author={Ruzante, Juliana M. and Harris, Beth and Plummer, Paul and Raineri, Raissa R. and Loy, John Dustin and Jacob, Megan and Sahin, Orhan and Kreuder, Amanda J.}, year={2022}, month={Dec} }
 @article{watson_hazen_rasko_jacob_elfenbein_stauffer_gookin_2021, title={Comparative Genomics of Atypical Enteropathogenic Escherichia coli from Kittens and Children Identifies Bacterial Factors Associated with Virulence in Kittens}, volume={89}, ISSN={["1098-5522"]}, DOI={10.1128/IAI.00619-20}, abstractNote={
            Typical enteropathogenic
            Escherichia coli
            (tEPEC) is a leading cause of diarrhea and associated death in children worldwide. Atypical EPEC (aEPEC) lacks the plasmid encoding bundle-forming pili and is considered less virulent, but the molecular mechanism of virulence is poorly understood.
          }, number={3}, journal={INFECTION AND IMMUNITY}, author={Watson, Victoria E. and Hazen, Tracy H. and Rasko, David A. and Jacob, Megan E. and Elfenbein, Johanna R. and Stauffer, Stephen H. and Gookin, Jody L.}, year={2021}, month={Mar} }
 @article{halleran_minch_slyvester_jacob_prange_baynes_foster_2021, title={Comparison of the Intestinal Pharmacokinetics of Two Different Florfenicol Dosing Regimens and Its Impact on the Prevalence and Phenotypic Resistance of E. coli and Enterococcus over Time}, volume={9}, ISSN={["2076-2607"]}, DOI={10.3390/microorganisms9091835}, abstractNote={In order to mitigate the food animal sector’s role in the growing threat of antimicrobial resistance (AMR), the World Health Organization (WHO) suggests the use of lower tier antimicrobials, such as florfenicol. Florfenicol has two dosing schemes used to treat primarily bovine respiratory disease. In this study, the objective was to characterize the plasma and gastrointestinal pharmacokinetics of each dosing regimen and assess the effect of these dosing regimens on the prevalence of resistant indicator bacteria over time. Twelve steers underwent abdominal surgery to facilitate the placement of ultrafiltration probes within the lumen of the ileum and colon, as well as placement of an interstitial probe. Following surgery, cattle were dosed with either 20 mg/kg IM every 48 h of florfenicol given twice (n = 6) or a single, subcutaneous dose (40 mg/kg, n = 6). Plasma, interstitial fluid, gastrointestinal ultrafiltrate, and feces were collected. Pharmacokinetic analysis demonstrated high penetration of florfenicol within the gastrointestinal tract for both the high and low dose group (300%, 97%, respectively). There was no significant difference noted between dosing groups in proportion or persistence of phenotypically resistant bacterial isolates; however, the percent of resistant isolates was high throughout the study period. The recommendation for the use of a lower tier antimicrobial, such as florfenicol, may allow for the persistence of co-resistance for antibiotics of high regulatory concern.}, number={9}, journal={MICROORGANISMS}, author={Halleran, Jennifer L. and Minch, Ryker and Slyvester, Hannah J. and Jacob, Megan E. and Prange, Timo and Baynes, Ronald and Foster, Derek M.}, year={2021}, month={Sep} }
 @article{halleran_callahan_jacob_sylvester_prange_papich_foster_2021, title={Effects of danofloxacin dosing regimen on gastrointestinal pharmacokinetics and fecal microbiome in steers}, volume={11}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-021-90647-z}, abstractNote={Abstract}, number={1}, journal={SCIENTIFIC REPORTS}, author={Halleran, J. L. and Callahan, B. J. and Jacob, M. E. and Sylvester, H. J. and Prange, T. and Papich, M. G. and Foster, D. M.}, year={2021}, month={May} }
 @article{graham_tefft_stowe_jacob_robertson_hawkins_2021, title={Factors associated with clinical interpretation of tracheal wash fluid from dogs with respiratory disease: 281 cases (2012-2017)}, volume={35}, ISSN={["1939-1676"]}, url={https://doi.org/10.1111/jvim.16052}, DOI={10.1111/jvim.16052}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={Graham, Amber M. and Tefft, Karen M. and Stowe, Devorah M. and Jacob, Megan E. and Robertson, James B. and Hawkins, Eleanor C.}, year={2021}, month={Mar}, pages={1073–1079} }
 @article{tyson_ceric_guag_nemser_borenstein_slavic_lippert_mcdowell_krishnamurthy_korosec_et al._2021, title={Genomics accurately predicts antimicrobial resistance in Staphylococcus pseudintermedius collected as part of Vet-LIRN resistance monitoring}, volume={254}, ISSN={["1873-2542"]}, DOI={10.1016/j.vetmic.2021.109006}, abstractNote={Whole-genome sequencing (WGS) has changed our understanding of bacterial pathogens, aiding outbreak investigations and advancing our knowledge of their genetic features. However, there has been limited use of genomics to understand antimicrobial resistance of veterinary pathogens, which would help identify emerging resistance mechanisms and track their spread. The objectives of this study were to evaluate the correlation between resistance genotypes and phenotypes for Staphylococcus pseudintermedius, a major pathogen of companion animals, by comparing broth microdilution antimicrobial susceptibility testing and WGS. From 2017-2019, we conducted antimicrobial susceptibility testing and WGS on S. pseudintermedius isolates collected from dogs in the United States as a part of the Veterinary Laboratory Investigation and Response Network (Vet-LIRN) antimicrobial resistance monitoring program. Across thirteen antimicrobials in nine classes, resistance genotypes correlated with clinical resistance phenotypes 98.4 % of the time among a collection of 592 isolates. Our findings represent isolates from diverse lineages based on phylogenetic analyses, and these strong correlations are comparable to those from studies of several human pathogens such as Staphylococcus aureus and Salmonella enterica. We uncovered some important findings, including that 32.3 % of isolates had the mecA gene, which correlated with oxacillin resistance 97.0 % of the time. We also identified a novel rpoB mutation likely encoding rifampin resistance. These results show the value in using WGS to assess antimicrobial resistance in veterinary pathogens and to reveal putative new mechanisms of resistance.}, journal={VETERINARY MICROBIOLOGY}, author={Tyson, Gregory H. and Ceric, Olgica and Guag, Jake and Nemser, Sarah and Borenstein, Stacey and Slavic, Durda and Lippert, Sarah and McDowell, Rebecca and Krishnamurthy, Aparna and Korosec, Shannon and et al.}, year={2021}, month={Mar} }
 @article{tomczyk_taylor_brown_kraker_el-saed_alshamrani_hendriksen_jacob_lofmark_perovic_et al._2021, title={Impact of the COVID-19 pandemic on the surveillance, prevention and control of antimicrobial resistance: a global survey}, volume={76}, ISSN={["1460-2091"]}, DOI={10.1093/jac/dkab300}, abstractNote={Abstract}, number={11}, journal={JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY}, author={Tomczyk, Sara and Taylor, Angelina and Brown, Allison and Kraker, Marlieke E. A. and El-Saed, Aiman and Alshamrani, Majid and Hendriksen, Rene S. and Jacob, Megan and Lofmark, Sonja and Perovic, Olga and et al.}, year={2021}, month={Nov}, pages={3045–3058} }
 @article{goggs_menard_altier_cummings_jacob_lalonde-paul_papich_norman_fajt_scott_et al._2021, title={Patterns of antimicrobial drug use in veterinary primary care and specialty practice: A 6-year multi-institution study}, volume={35}, ISSN={["1939-1676"]}, url={https://doi.org/10.1111/jvim.16136}, DOI={10.1111/jvim.16136}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, publisher={Wiley}, author={Goggs, Robert and Menard, Julie M. and Altier, Craig and Cummings, Kevin J. and Jacob, Megan E. and Lalonde-Paul, Denise F. and Papich, Mark G. and Norman, Keri N. and Fajt, Virginia R. and Scott, H. Morgan and et al.}, year={2021}, month={May}, pages={1496–1508} }
 @article{thanissery_mclaren_rivera_reed_betrapally_burdette_winston_jacob_callahan_theriot_2020, title={Clostridioides difficile carriage in animals and the associated changes in the host fecal microbiota}, volume={66}, ISSN={["1095-8274"]}, DOI={10.1016/j.anaerobe.2020.102279}, abstractNote={The relationship between the gut microbiota and Clostridioides difficile, and its role in the severity of C. difficile infection in humans is an area of active research. Intestinal carriage of toxigenic and non-toxigenic C. difficile strains, with and without clinical signs, is reported in animals, however few studies have looked at the risk factors associated with C. difficile carriage and the role of the host gut microbiota. Here, we isolated and characterized C. difficile strains from different animal species (predominantly canines (dogs), felines (cats), and equines (horses)) that were brought in for tertiary care at North Carolina State University Veterinary Hospital. C. difficile strains were characterized by toxin gene profiling, fluorescent PCR ribotyping, and antimicrobial susceptibility testing. 16S rRNA gene sequencing was done on animal feces to investigate the relationship between the presence of C. difficile and the gut microbiota in different hosts. Here, we show that C. difficile was recovered from 20.9% of samples (42/201), which included 33 canines, 2 felines, and 7 equines. Over 69% (29/42) of the isolates were toxigenic and belonged to 14 different ribotypes including ones known to cause CDI in humans. The presence of C. difficile results in a shift in the fecal microbial community structure in both canines and equines. Commensal Clostridium hiranonis was negatively associated with C. difficile in canines. Further experimentation showed a clear antagonistic relationship between the two strains in vitro, suggesting that commensal Clostridia might play a role in colonization resistance against C. difficile in different hosts.}, journal={ANAEROBE}, author={Thanissery, R. and McLaren, M. R. and Rivera, A. and Reed, A. D. and Betrapally, N. S. and Burdette, T. and Winston, J. A. and Jacob, M. and Callahan, B. J. and Theriot, C. M.}, year={2020}, month={Dec} }
 @article{gilbertie_levent_norman_vinasco_scott_jacob_2020, title={Comprehensive phenotypic and genotypic characterization and comparison of virulence, biofilm, and antimicrobial resistance in urinary Escherichia coli isolated from canines}, volume={249}, ISSN={["1873-2542"]}, DOI={10.1016/j.vetmic.2020.108822}, abstractNote={Urinary tract infections (UTIs) affect nearly half of women and an estimated 14 % of the canine companion animal population at least once in their lifetime. As with humans, Escherichia coli is the most commonly isolated bacteria from canine UTIs and infections are dominated by specific phylogenetic groups with notable virulence attributes. In this study, we evaluated uropathogenic E. coli (UPEC) (n = 69) isolated from canine UTIs phenotypically and genotypically for virulence factors, biofilm formation and antimicrobial resistance profiles. Biofilm formation in UPEC strains was positively associated with common virulence factors including papG (p = 0.006), fimH (p < 0.0001), sfaS (p = 0.004), focA (p = 0.004), cnf-1 (p = 0.009) and hlyA (p = 0.006). There was a negative association between biofilm formation and phenotypic antimicrobial resistance for ampicillin (p < 0.0004), ciprofloxacin (p < 0.0001), and trimethoprim-sulfamethoxazole (p < 0.02), as well as multidrug resistance (isolates resistant to ≥ 3 classes of antimicrobials) (p < 0.0002), and the presence of extended spectrum beta-lactamase (ESBL)-producing genes (p < 0.05). In conclusion, UPECs isolated from clinical cases of canine UTIs show a broad negative association between antimicrobial resistance and biofilm formation, and this observation is supported both by phenotypic and genotypic endpoints. As the biofilm formation may result in antimicrobial tolerance, this could be a secondary evasive tactic of UPEC lacking traditional antimicrobial resistance traits. This observation is important for veterinary practitioners to consider when treating puzzling chronic intractable and/or recurrent cases of UTI that appear to be susceptible to antimicrobial therapy via traditional antimicrobial susceptibility testing (AST) methods.}, journal={VETERINARY MICROBIOLOGY}, author={Gilbertie, Jessica M. and Levent, Gizem and Norman, Keri N. and Vinasco, Javier and Scott, H. Morgan and Jacob, Megan E.}, year={2020}, month={Oct} }
 @article{eichhorn_luebke-becker_lapschies_jacob_baeumer_fulde_2020, title={Draft Genome Sequence of Staphylococcus pseudintermedius Strain 13-13613, Isolated from a Case of Canine Pyoderma}, volume={9}, ISBN={2576-098X}, DOI={10.1128/MRA.00027-20}, abstractNote={
            Here, we report the draft genome sequence of
            Staphylococcus pseudintermedius
            strain 13-13613, isolated from a case of canine pyoderma. The draft genome contains 2,533,486 bp in 570 contigs.
          }, number={7}, journal={MICROBIOLOGY RESOURCE ANNOUNCEMENTS}, author={Eichhorn, Inga and Luebke-Becker, Antina and Lapschies, Antje-Maria and Jacob, Megan and Baeumer, Wolfgang and Fulde, Marcus}, year={2020}, month={Feb} }
 @article{jacob_keelara_aidara-kane_alvarez_fedorka-cray_2020, title={Optimizing a Screening Protocol for Potential Extended-Spectrum beta-Lactamase Escherichia coli on MacConkey Agar for Use in a Global Surveillance Program}, volume={58}, ISSN={["1098-660X"]}, DOI={10.1128/JCM.01039-19}, abstractNote={
            The increasing prevalence of extended-spectrum beta-lactamase (ESBL)-producing
            Escherichia coli
            is worrisome. Coordinated efforts to better understand global prevalence and risk factors are needed. Developing lower- and middle-income countries need reliable, readily available, and cost-effective solutions for detecting ESBL
            E. coli
            to contribute to global surveillance. We evaluated MacConkey agar supplemented with ceftriaxone or cefotaxime as a screening method for accurately detecting and quantifying potential ESBL
            E. coli
            .
          }, number={9}, journal={JOURNAL OF CLINICAL MICROBIOLOGY}, author={Jacob, Megan E. and Keelara, Shivaramu and Aidara-Kane, Awa and Alvarez, Jorge R. Matheu and Fedorka-Cray, Paula J.}, year={2020}, month={Sep} }
 @article{gilbertie_schaer_schubert_jacob_menegatti_lavoie_schnabel_2020, title={Platelet-rich plasma lysate displays antibiofilm properties and restores antimicrobial activity against synovial fluid biofilms in vitro}, volume={38}, ISSN={["1554-527X"]}, DOI={10.1002/jor.24584}, abstractNote={Abstract}, number={6}, journal={JOURNAL OF ORTHOPAEDIC RESEARCH}, author={Gilbertie, Jessica M. and Schaer, Thomas P. and Schubert, Alicia G. and Jacob, Megan E. and Menegatti, Stefano and Lavoie, R. Ashton and Schnabel, Lauren V}, year={2020}, month={Jun}, pages={1365–1374} }
 @article{carlson_nixon_jacob_messenger_2020, title={Sterility and concentration of liposomal bupivacaine single-use vial when used in a multiple-dose manner}, volume={49}, ISSN={["1532-950X"]}, DOI={10.1111/vsu.13380}, abstractNote={Abstract}, number={4}, journal={VETERINARY SURGERY}, author={Carlson, Alexandra R. and Nixon, Emma and Jacob, Megan E. and Messenger, Kristen M.}, year={2020}, month={May}, pages={772–777} }
 @article{foster_jacob_farmer_callahan_theriot_kathariou_cernicchiaro_prange_papich_2019, title={Ceftiofur formulation differentially affects the intestinal drug concentration, resistance of fecal Escherichia coli, and the microbiome of steers}, volume={14}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0223378}, abstractNote={Antimicrobial drug concentrations in the gastrointestinal tract likely drive antimicrobial resistance in enteric bacteria. Our objective was to determine the concentration of ceftiofur and its metabolites in the gastrointestinal tract of steers treated with ceftiofur crystalline-free acid (CCFA) or ceftiofur hydrochloride (CHCL), determine the effect of these drugs on the minimum inhibitory concentration (MIC) of fecal Escherichia coli, and evaluate shifts in the microbiome. Steers were administered either a single dose (6.6 mg/kg) of CCFA or 2.2 mg/kg of CHCL every 24 hours for 3 days. Ceftiofur and its metabolites were measured in the plasma, interstitium, ileum and colon. The concentration and MIC of fecal E. coli and the fecal microbiota composition were assessed after treatment. The maximum concentration of ceftiofur was higher in all sampled locations of steers treated with CHCL. Measurable drug persisted longer in the intestine of CCFA-treated steers. There was a significant decrease in E. coli concentration (P = 0.002) within 24 hours that persisted for 2 weeks after CCFA treatment. In CHCL-treated steers, the mean MIC of ceftiofur in E. coli peaked at 48 hours (mean MIC = 20.45 ug/ml, 95% CI = 10.29–40.63 ug/ml), and in CCFA-treated steers, mean MIC peaked at 96 hours (mean MIC = 10.68 ug/ml, 95% CI = 5.47–20.85 ug/ml). Shifts in the microbiome of steers in both groups were due to reductions in Firmicutes and increases in Bacteroidetes. CCFA leads to prolonged, low intestinal drug concentrations, and is associated with decreased E. coli concentration, an increased MIC of ceftiofur in E. coli at specific time points, and shifts in the fecal microbiota. CHCL led to higher intestinal drug concentrations over a shorter duration. Effects on E. coli concentration and the microbiome were smaller in this group, but the increase in the MIC of ceftiofur in fecal E. coli was similar.}, number={10}, journal={PLOS ONE}, author={Foster, Derek M. and Jacob, Megan E. and Farmer, Kyle A. and Callahan, Benjamin J. and Theriot, Casey M. and Kathariou, Sophia and Cernicchiaro, Natalia and Prange, Timo and Papich, Mark G.}, year={2019}, month={Oct} }
 @article{ceric_tyson_goodman_mitchell_zhang_prarat_cui_peak_scaria_antony_et al._2019, title={Enhancing the one health initiative by using whole genome sequencing to monitor antimicrobial resistance of animal pathogens: Vet-LIRN collaborative project with veterinary diagnostic laboratories in United States and Canada}, volume={15}, ISSN={["1746-6148"]}, DOI={10.1186/s12917-019-1864-2}, abstractNote={Antimicrobial resistance (AMR) of bacterial pathogens is an emerging public health threat. This threat extends to pets as it also compromises our ability to treat their infections. Surveillance programs in the United States have traditionally focused on collecting data from food animals, foods, and people. The Veterinary Laboratory Investigation and Response Network (Vet-LIRN), a national network of 45 veterinary diagnostic laboratories, tested the antimicrobial susceptibility of clinically relevant bacterial isolates from animals, with companion animal species represented for the first time in a monitoring program. During 2017, we systematically collected and tested 1968 isolates. To identify genetic determinants associated with AMR and the potential genetic relatedness of animal and human strains, whole genome sequencing (WGS) was performed on 192 isolates: 69 Salmonella enterica (all animal sources), 63 Escherichia coli (dogs), and 60 Staphylococcus pseudintermedius (dogs).We found that most Salmonella isolates (46/69, 67%) had no known resistance genes. Several isolates from both food and companion animals, however, showed genetic relatedness to isolates from humans. For pathogenic E. coli, no resistance genes were identified in 60% (38/63) of the isolates. Diverse resistance patterns were observed, and one of the isolates had predicted resistance to fluoroquinolones and cephalosporins, important antibiotics in human and veterinary medicine. For S. pseudintermedius, we observed a bimodal distribution of resistance genes, with some isolates having a diverse array of resistance mechanisms, including the mecA gene (19/60, 32%).The findings from this study highlight the critical importance of veterinary diagnostic laboratory data as part of any national antimicrobial resistance surveillance program. The finding of some highly resistant bacteria from companion animals, and the observation of isolates related to those isolated from humans demonstrates the public health significance of incorporating companion animal data into surveillance systems. Vet-LIRN will continue to build the infrastructure to collect the data necessary to perform surveillance of resistant bacteria as part of fulfilling its mission to advance human and animal health. A One Health approach to AMR surveillance programs is crucial and must include data from humans, animals, and environmental sources to be effective.}, journal={BMC VETERINARY RESEARCH}, author={Ceric, Olgica and Tyson, Gregory H. and Goodman, Laura B. and Mitchell, Patrick K. and Zhang, Yan and Prarat, Melanie and Cui, Jing and Peak, Laura and Scaria, Joy and Antony, Linto and et al.}, year={2019}, month={May} }
 @article{gilbertie_schnabel_hickok_jacob_conlon_shapiro_parvizi_schaer_2019, title={Equine or porcine synovial fluid as a novel ex vivo model for the study of bacterial free-floating biofilms that form in human joint infections}, volume={14}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0221012}, abstractNote={Bacterial invasion of synovial joints, as in infectious or septic arthritis, can be difficult to treat in both veterinary and human clinical practice. Biofilms, in the form of free-floating clumps or aggregates, are involved with the pathogenesis of infectious arthritis and periprosthetic joint infection (PJI). Infection of a joint containing an orthopedic implant can additionally complicate these infections due to the presence of adherent biofilms. Because of these biofilm phenotypes, bacteria within these infected joints show increased antimicrobial tolerance even at high antibiotic concentrations. To date, animal models of PJI or infectious arthritis have been limited to small animals such as rodents or rabbits. Small animal models, however, yield limited quantities of synovial fluid making them impractical for in vitro research. Herein, we describe the use of ex vivo equine and porcine models for the study of synovial fluid induced biofilm aggregate formation and antimicrobial tolerance. We observed Staphylococcus aureus and other bacterial pathogens adapt the same biofilm aggregate phenotype with significant antimicrobial tolerance in both equine and porcine synovial fluid, analogous to human synovial fluid. We also demonstrate that enzymatic dispersal of synovial fluid aggregates restores the activity of antimicrobials. Future studies investigating the interaction of bacterial cell surface proteins with host synovial fluid proteins can be readily carried out in equine or porcine ex vivo models to identify novel drug targets for treatment of prevention of these difficult to treat infectious diseases.}, number={8}, journal={PLOS ONE}, author={Gilbertie, Jessica M. and Schnabel, Lauren V. and Hickok, Noreen J. and Jacob, Megan E. and Conlon, Brian P. and Shapiro, Irving M. and Parvizi, Javad and Schaer, Thomas P.}, year={2019}, month={Aug} }
 @article{cullen_jacob_cornish_vanderschel_cotter_cubeta_carbone_gilger_2019, title={Multi-locus DNA sequence analysis, antifungal agent susceptibility, and fungal keratitis outcome in horses from Southeastern United States}, volume={14}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0214214}, DOI={10.1371/journal.pone.0214214}, abstractNote={Morphological characterization and multi-locus DNA sequence analysis of fungal isolates obtained from 32 clinical cases of equine fungal keratitis (FK) was performed to identify species and determine associations with antifungal susceptibility, response to therapy and clinical outcome. Two species of Aspergillus (A. flavus and A. fumigatus) and three species of Fusarium (F. falciforme, F. keratoplasticum, and F. proliferatum) were the most common fungi isolated and identified from FK horses. Most (91%) equine FK Fusarium nested within the Fusarium solani species complex (FSSC) with nine genetically diverse strains/lineages, while 83% of equine FK Aspergillus nested within the A. flavus clade with three genetically diverse lineages. Fungal species and evolutionary lineage were not associated with clinical outcome. However, species of equine FK Fusarium were more likely (p = 0.045) to be associated with stromal keratitis. Species of Aspergillus were more susceptible to voriconazole and terbinafine than species of Fusarium, while species of Fusarium were more susceptible to thiabendazole than species of Aspergillus. At the species level, A. fumigatus and A. flavus were more susceptible to voriconazole and terbinafine than F. falciforme. Natamycin susceptibility was higher for F. falciforme and A. fumigatus compared to A. flavus. Furthermore, F. falciforme was more susceptible to thiabendazole than A. flavus and A. fumigatus. These observed associations of antifungal sensitivity to natamycin, terbinafine, and thiabendazole demonstrate the importance of fungal identification to the species rather than genus level. The results of this study suggest that treatment of equine FK with antifungal agents requires accurate fungal species identification.}, number={3}, journal={PLOS ONE}, publisher={Public Library of Science (PLoS)}, author={Cullen, Megan and Jacob, Megan E. and Cornish, Vicki and VanderSchel, Ian Q. and Cotter, Henry Van T. and Cubeta, Marc A. and Carbone, Ignazio and Gilger, Brian C.}, editor={Kniemeyer, OlafEditor}, year={2019}, month={Mar}, pages={e0214214} }
 @article{barash_birkenheuer_vaden_jacob_2018, title={Agreement between Parallel Canine Blood and Urine Cultures: Is Urine Culture the Poor Man's Blood Culture?}, volume={56}, ISSN={["1098-660X"]}, DOI={10.1128/JCM.00506-18}, abstractNote={Bloodstream infections are a significant cause of morbidity and mortality in critically ill dogs, but due to cost and difficulties in sample acquisition, blood cultures are infrequently obtained. In ill dogs, urine cultures may be recommended as surrogates for blood cultures.}, number={9}, journal={JOURNAL OF CLINICAL MICROBIOLOGY}, author={Barash, Nanelle R. and Birkenheuer, Adam J. and Vaden, Shelly L. and Jacob, Megan E.}, year={2018}, month={Sep} }
 @article{kern_jacob_gilbertie_vaden_lyle_2018, title={Characteristics of Dogs with Biofilm-Forming Escherichia Coli Urinary Tract Infections}, volume={32}, ISSN={["1939-1676"]}, DOI={10.1111/jvim.15231}, abstractNote={BackgroundBacterial urinary tract infections (UTIs) are common in companion animals. Increasing awareness of biofilm‐forming bacteria raises concern regarding the appropriate diagnosis, treatment, and prognosis of UTIs associated with these organisms.}, number={5}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={Kern, Zachary T. and Jacob, Megan E. and Gilbertie, Jessica M. and Vaden, Shelly L. and Lyle, Sara K.}, year={2018}, pages={1645–1651} }
 @article{banovic_olivry_baumer_paps_stahl_rogers_jacob_2018, title={Diluted sodium hypochlorite (bleach) in dogs: antiseptic efficacy, local tolerability and in vitro effect on skin barrier function and inflammation}, volume={29}, ISSN={["1365-3164"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85040710868&partnerID=MN8TOARS}, DOI={10.1111/vde.12487}, abstractNote={BackgroundDiluted sodium hypochlorite represents an inexpensive and widely available topical antiseptic, but there are no tolerability and efficacy data in veterinary dermatology.}, number={1}, journal={VETERINARY DERMATOLOGY}, author={Banovic, Frane and Olivry, Thierry and Baumer, Wolfgang and Paps, Judy and Stahl, Jessica and Rogers, Ana and Jacob, Megan}, year={2018}, month={Feb} }
 @article{ferguson_jacob_theriot_callahan_prange_papich_foster_2018, title={Dosing Regimen of Enrofloxacin Impacts Intestinal Pharmacokinetics and the Fecal Microbiota in Steers}, volume={9}, ISSN={1664-302X}, url={http://dx.doi.org/10.3389/fmicb.2018.02190}, DOI={10.3389/fmicb.2018.02190}, abstractNote={Objective: The intestinal concentrations of antimicrobial drugs that select for resistance in fecal bacteria of cattle are poorly understood. Our objective was to associate active drug concentrations in the intestine of steers with changes in the resistance profile and composition of the fecal microbiome. Methods: Steers were administered either a single dose (12.5 mg/kg) or 3 multiple doses (5 mg/kg) of enrofloxacin subcutaneously every 24 h. Enrofloxacin and ciprofloxacin concentrations in intestinal fluid were measured over 96 h, and the abundance and MIC of E. coli in culture and the composition of the fecal microbiota by 16S rRNA gene sequencing were assessed over 192 h after initial treatment. Results: Active drug concentrations in the ileum and colon exceeded plasma and interstitial fluid concentrations, but were largely eliminated by 48 h after the last dose. The concentration of E. coli in the feces significantly decreased during peak drug concentrations, but returned to baseline by 96 h in both groups. The median MIC of E. coli isolates increased for 24 h in the single dose group, and for 48 h in the multiple dose group. The median MIC was higher in the multiple dose group when compared to the single dose group starting 12 h after the initial dose. The diversity of the fecal microbiota did not change in either treatment group, and taxa-specific changes were primarily seen in phyla commonly associated with the rumen. Conclusions: Both dosing regimens of enrofloxacin achieve high concentrations in the intestinal lumen, and the rapid elimination mitigates long-term impacts on fecal E. coli resistance and the microbiota.}, journal={Frontiers in Microbiology}, publisher={Frontiers Media SA}, author={Ferguson, Kaitlyn M. and Jacob, Megan E. and Theriot, Casey M. and Callahan, Benjamin J. and Prange, Timo and Papich, Mark G. and Foster, Derek M.}, year={2018}, month={Sep} }
 @article{scharf_dent_jacob_moore_2018, title={Efficacy of vaporized hydrogen peroxide for repeated sterilization of a single‐use single‐incision laparoscopic surgery port}, volume={48}, ISSN={0161-3499 1532-950X}, url={http://dx.doi.org/10.1111/vsu.12905}, DOI={10.1111/vsu.12905}, abstractNote={Abstract}, number={S1}, journal={Veterinary Surgery}, publisher={Wiley}, author={Scharf, Valery F. and Dent, Brian and Jacob, Megan E. and Moore, Brandon}, year={2018}, month={May}, pages={O59–O65} }
 @article{sylvester_griffith_jacob_foster_2018, title={Factors associated with strongyle infection in goats at the individual and farm level}, volume={253}, ISSN={["1943-569X"]}, url={https://doi.org/10.2460/javma.253.7.907}, DOI={10.2460/javma.253.7.907}, abstractNote={Abstract}, number={7}, journal={JAVMA-JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION}, author={Sylvester, Hannah J. and Griffith, Emily H. and Jacob, Megan E. and Foster, Derek M.}, year={2018}, month={Oct}, pages={907–917} }
 @article{gilbertie_schnabel_stefanovski_kelly_jacob_schaer_2018, title={Gram-negative multi-drug resistant bacteria influence survival to discharge for horses with septic synovial structures: 206 Cases (2010-2015)}, volume={226}, ISSN={["1873-2542"]}, DOI={10.1016/j.vetmic.2018.10.009}, abstractNote={Bacterial colonization of synovial structures can cause infections that are difficult to treat. Systemic and local antimicrobials and repeated joint lavages are the mainstays of therapy. However, despite aggressive treatments, infection may persist, leading to significant tissue damage or death of the patient. In order to investigate the impact of bacterial culture and antimicrobial resistance on survival to discharge, we reviewed medical records of horses admitted to the University of Pennsylvania's large animal teaching hospital from 2010-2015. Two-hundred and six cases with a definitive diagnosis of septic synovitis and a synovial fluid sample submitted for microbiological culture were included in the study. Of these horses, 48% were culture negative and 52% were positive for any bacterial growth, of which 66% were gram-positive and 28% were gram-negative aerobic organisms with 4% anaerobic and 2% fungal organisms. Overall survival to discharge from hospital was 86%. Horses that had negative growth on culture were more likely to survive until discharge (p < 0.02). Multivariable analyses revealed that the likelihood of euthanasia was significantly associated with identification of coagulase positive Staphylococcus spp. (OR 7.66, 5.46-10.74, p < 0.0001), β-hemolytic Streptococcus spp. (OR 5.18, 3.56-7.55, p < 0.0001), Enterococcus spp. (OR 18.38, 11.45-29.52, p = 0.002), Enterobacteriaceae (OR 31.37, 22.28-44.17, p < 0.0001), Pseudomonas aeruginosa (OR 9.31, 5.30-16.34, p = 0.0004) or other gram-negative species (OR 3.51, 2.07-5.94, p = 0.001). Multi-drug resistance and gram-negative bacteria species were associated with significantly decreased survival rates (OR 119.24, 70.57-201.46, p < 0.0001). In conclusion, prognosis for survival to discharge was poor for horses that were infected with gram-negative organisms, particularly those with MDR phenotypes.}, journal={VETERINARY MICROBIOLOGY}, author={Gilbertie, Jessica M. and Schnabel, Lauren V and Stefanovski, Darko and Kelly, Donna J. and Jacob, Megan E. and Schaer, Thomas P.}, year={2018}, month={Nov}, pages={64–73} }
 @article{whitehead_vanetten_jacob_harrison_2018, title={Microbial integrity of preservative-free alfaxalone in a multiple-use system for two storage conditions and three handling techniques}, volume={79}, ISSN={["1943-5681"]}, DOI={10.2460/ajvr.79.7.704}, abstractNote={Abstract}, number={7}, journal={AMERICAN JOURNAL OF VETERINARY RESEARCH}, author={Whitehead, Michelle C. and Vanetten, Chelsey L. and Jacob, Megan E. and Harrison, Tara M.}, year={2018}, month={Jul}, pages={704–710} }
 @article{watson_jacob_flowers_strong_debroy_gookin_2017, title={Association of Atypical Enteropathogenic Escherichia coli with Diarrhea and Related Mortality in Kittens}, volume={55}, ISSN={0095-1137 1098-660X}, url={http://dx.doi.org/10.1128/JCM.00403-17}, DOI={10.1128/jcm.00403-17}, abstractNote={ABSTRACT}, number={9}, journal={Journal of Clinical Microbiology}, publisher={American Society for Microbiology}, author={Watson, Victoria E. and Jacob, Megan E. and Flowers, James R. and Strong, Sandra J. and DebRoy, Chitrita and Gookin, Jody L.}, editor={Fenwick, BradEditor}, year={2017}, month={Jun}, pages={2719–2735} }
 @article{mohiti-asli_risselada_jacob_pourdeyhimi_loboa_2017, title={Creation and Evaluation of New Porcine Model for Investigation of Treatments of Surgical Site Infection}, volume={23}, ISSN={["1937-3392"]}, DOI={10.1089/ten.tec.2017.0024}, abstractNote={Surgical site infection (SSI) is the most common cause of surgical failure, increasing the risks of postoperative mortality and morbidity. Recently, it has been reported that the use of antimicrobial dressings at the incision site help with prevention of SSI. Despite the increased body of research on the development of different types of antimicrobial dressings for this application, to our knowledge, nobody has reported a reliable large animal model to evaluate the efficacy of developed materials in a preclinical SSI model. In this study, we developed a porcine full-thickness incision model to investigate SSI caused by methicillin-resistant Staphylococcus aureus (MRSA), the leading cause of SSI in the United States. Using this model, we then evaluated the efficacy of our newly developed silver releasing nanofibrous dressings for preventing and inhibiting MRSA infection. Our results confirmed the ease and practicality of a new porcine model as an in vivo platform for evaluation of biomaterials for SSI. Using this model, we found that our silver releasing scaffolds significantly reduced bacterial growth in wounds inoculated with MRSA relative to nontreated controls and to wounds treated with the gold standard, silver sulfadiazine, without causing inflammation at the wound site. Findings from this study confirm the potential of our silver-releasing nanofibrous scaffolds for treatment/prevention of SSI, and introduce a new porcine model for in vivo evaluation of additional SSI treatment approaches.}, number={11}, journal={TISSUE ENGINEERING PART C-METHODS}, author={Mohiti-Asli, Mahsa and Risselada, Marije and Jacob, Megan and Pourdeyhimi, Behnam and Loboa, Elizabeth G.}, year={2017}, month={Nov}, pages={795–803} }
 @article{swift_foster_rogers_sylvester_griffith_jacob_2017, title={Efficacy of an Escherichia coli O157:H7 SRP Vaccine in Orally Challenged Goats and Strain Persistence Over Time}, volume={14}, ISSN={["1556-7125"]}, url={https://doi.org/10.1089/fpd.2016.2213}, DOI={10.1089/fpd.2016.2213}, abstractNote={Small ruminants have been implicated in outbreaks of Escherichia coli O157:H7 at livestock exhibitions throughout the United States. Additionally, goat meat or milk may serve as a reservoir for foodborne transmission of the organism. These associations highlight the public health importance of an effective strategy to reduce E. coli O157:H7 shedding in goats. We examined the efficacy of the SRP® vaccine in goats orally challenged with E. coli O157:H7. Mixed-breed goats (n = 14) were randomly allocated into vaccinated and unvaccinated treatments (n = 7 per treatment). Goats were housed with a vaccinated and unvaccinated animal in each pen. Feces were collected for 3 weeks, then at necropsy, gastrointestinal contents were collected to determine the concentration of E. coli O157:H7. Three isolates per positive sample were saved and evaluated by pulsed-field gel electrophoresis (PFGE) to assess strain persistence over time. The mean concentration of E. coli O157:H7 in the feces of goats was numerically reduced in the vaccinated treatment; however, it was not statistically significant. In addition, the total number of days goats were fecal positive for E. coli O157:H7 were not different between vaccinated and unvaccinated treatments. Pulsotypes of isolates revealed that goats initially shed two of the four challenge strains of E. coli O157:H7, after which there was a distinct shift to two different strains. Further work is needed to evaluate cost-effective intervention strategies that reliably reduce E. coli O157:H7 shedding in goats, particularly those that may reduce the risk of transmission at public events, including petting zoos and fairs.}, number={3}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Swift, Jacob M. and Foster, Derek M. and Rogers, Anna T. and Sylvester, Hannah J. and Griffith, Emily H. and Jacob, Megan E.}, year={2017}, month={Mar}, pages={160–166} }
 @article{bäumer_bizikova_jacob_linder_2017, title={Establishing a canine superficial pyoderma model}, volume={122}, ISSN={1364-5072}, url={http://dx.doi.org/10.1111/jam.13362}, DOI={10.1111/jam.13362}, abstractNote={Pyoderma, predominantly associated with Staphylococcus pseudintermedius, is a common skin infection of dogs that typically requires long‐lasting treatments, complicated by increasing antimicrobial resistance. To investigate new treatment strategies, we aimed at establishing a dog model of pyoderma that closely mimics the natural disease.}, number={2}, journal={Journal of Applied Microbiology}, publisher={Wiley}, author={Bäumer, W. and Bizikova, P. and Jacob, M. and Linder, K.E.}, year={2017}, month={Jan}, pages={331–337} }
 @article{fogle_jacob_blikslager_edwards_wagner_dean_fogle_2016, title={Comparison of lipopolysaccharides and soluble CD14 measurement between clinically endotoxaemic and nonendotoxaemic horses}, volume={49}, ISSN={0425-1644}, url={http://dx.doi.org/10.1111/evj.12582}, DOI={10.1111/evj.12582}, abstractNote={Summary}, number={2}, journal={Equine Veterinary Journal}, publisher={Wiley}, author={Fogle, J. and Jacob, M. and Blikslager, A. and Edwards, A. and Wagner, B. and Dean, K. and Fogle, C.}, year={2016}, month={May}, pages={155–159} }
 @article{jacob_crowell_fauls_griffith_ferris_2016, title={Diagnostic accuracy of a rapid immunoassay for point-of-care detection of urinary tract infection in dogs}, volume={77}, ISSN={["1943-5681"]}, DOI={10.2460/ajvr.77.2.162}, abstractNote={Abstract}, number={2}, journal={AMERICAN JOURNAL OF VETERINARY RESEARCH}, author={Jacob, Megan E. and Crowell, M. Denise and Fauls, Megan B. and Griffith, Emily H. and Ferris, Kelli K.}, year={2016}, month={Feb}, pages={162–166} }
 @article{foster_poulsen_sylvester_jacob_casulli_farkas_2016, title={Effect of high-pressure processing of bovine colostrum on immunoglobulin G concentration, pathogens, viscosity, and transfer of passive immunity to calves}, volume={99}, ISSN={["1525-3198"]}, url={https://doi.org/10.3168/jds.2016-11204}, DOI={10.3168/jds.2016-11204}, abstractNote={This study aimed to determine the effects of high-pressure processing on the immunoglobulin concentration, microbial load, viscosity, and transfer of passive immunity to calves when applied to bovine colostrum as an alternative to thermal pasteurization. A pilot study using Staphylococcus aureus was conducted to determine which pressure-time treatments are most appropriate for use with bovine colostrum, with the goals of maximizing bacterial inactivation while minimizing IgG content and viscosity changes. Following the pilot study, an inoculation study was conducted in which first-milking colostrum samples from Holstein-Friesian cows were inoculated with known concentrations of various bacteria or viruses and pressure processed at either 300 MPa for up to 60min or at 400MPa for up to 30min. The recovery of total native aerobic bacteria, Escherichia coli, Salmonella enterica ssp. enterica serovar Dublin, Mycobacterium avium ssp. paratuberculosis, bovine herpesvirus type 1, and feline calicivirus were determined after processing. Colostrum IgG content was measured before and after pressure processing. Shear stress and viscosity for each treatment was determined over shear rates encompassing those found during calf feeding and at normal bovine body temperature (37.8°C). Following a calf trial, serum IgG concentration was measured in 14 calves fed 4 L of colostrum pressure processed at 400MPa for 15min. In the pilot study, S. aureus was effectively reduced with pressure treatment at 300 and 400MPa (0, 5, 10, 15, 30, and 45min), with 2 treatments at 400MPa (30, 45min) determined to be inappropriate for use with bovine colostrum due to viscosity and IgG changes. High-pressure processing at 300MPa (30, 45, and 60min) and 400MPa (10, 15, and 20min) was shown to effectively reduce total native aerobic bacteria, E. coli, Salmonella Dublin, bovine herpesvirus type 1, and feline calicivirus populations in bovine colostrum, but no decrease occurred in Mycobacterium avium ssp. paratuberculosis. All inoculation study pressure treatments insignificantly decreased IgG content of colostrum. Treatment of colostrum at 400MPa for 15min during the calf trial decreased IgG content of colostrum. Treatment at 400MPa for 15min increased colostrum viscosity, with 2 of 14 samples requiring dilution with water for calf feeding. Calves fed pressure-processed colostrum had similar serum IgG but lower efficiency of absorption than calves fed heat-treated colostrum. The results of this study suggest that high-pressure processing of bovine colostrum maintains an acceptable IgG level while decreasing bacterial and viral counts. Changes in viscosity sometimes made calf feeding more difficult, but still feasible. Additional research to optimize this technology for on-farm use is necessary.}, number={11}, journal={JOURNAL OF DAIRY SCIENCE}, author={Foster, Derek M. and Poulsen, Keith P. and Sylvester, Hannah J. and Jacob, Megan E. and Casulli, Kaitlyn E. and Farkas, Brian E.}, year={2016}, month={Nov}, pages={8575–8588} }
 @article{wilson_holland_step_jacob_vanoverbeke_richards_nagaraja_krehbiel_2016, title={Feeding wet distillers grains plus solubles with and without a direct-fed microbial to determine performance, carcass characteristics, and fecal shedding of Escherichia coli O157:H7 in feedlot heifers}, volume={94}, ISSN={["1525-3163"]}, DOI={10.2527/jas.2015-9601}, abstractNote={The inclusion of wet distillers grains plus solubles (WDGS) in feedlot diets has become a common practice in many regions of the United States due to the expanded production of byproducts and fluctuating corn prices related to ethanol production and other factors. In addition, societal concerns over the continued use of antimicrobials in agriculture production combined with an enhanced interest in disease and pathogen prevention in the food supply have led to an increased interest in use of direct-fed microbials (DFM) in growing and finishing cattle. Direct-fed microbials have been shown to improve ADG and feed efficiency, alter ruminal fermentation, and decrease fecal shedding of potential harmful pathogens in feedlot cattle in some experiments. The objective of this experiment was to evaluate the effects of WDGS inclusion with or without a DFM containing (1 × 10 cfu ∙ heifer ∙ d) combined with (1 × 10 cfu ∙ heifer ∙ d) on the performance, carcass characteristics, and O157:H7 shedding in feedlot heifers. In early August, 288 crossbred heifers (initial BW = 295 ± 28 kg) were assigned to 1 of 4 treatments (12 pens per treatment; 6 heifers per pen) in a randomized complete block design with a 2 × 2 factorial arrangement of treatments. Body weights and fecal grab samples were obtained at approximately 28-d intervals throughout the experiment. Across the feeding period, heifers fed 30% WDGS tended ( = 0.09) to have greater ADG and had greater carcass-adjusted ADG ( = 0.05) compared with heifers fed dry-rolled corn (DRC). Dry matter intake was not affected ( = 0.65) by diet, although carcass-adjusted G:F tended ( = 0.10) to be improved for heifers fed WDGS. Heifers fed 30% WDGS tended ( ≤ 0.10) to have greater fat thickness at the 12th rib, lower marbling scores, and higher yield grades. The inclusion of . combined with . in the diet had no effect ( > 0.10) on performance or carcass merit in the present experiment. The incidence of O157:H7 throughout the experiment was low, with only 18 positive samples across all sampling periods. Neither WDGS inclusion nor the inclusion of . combined with . in the diet had any effect ( > 0.10) on O157:H7 shedding in this experiment. Feeding 30% WDGS to feedlot heifers improved animal performance compared to the DRC-based control diet.}, number={1}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Wilson, B. K. and Holland, B. P. and Step, D. L. and Jacob, M. E. and VanOverbeke, D. L. and Richards, C. J. and Nagaraja, T. G. and Krehbiel, C. R.}, year={2016}, month={Jan}, pages={297–305} }
 @article{palerme_pan_parsons_kathariou_ward_jacob_2016, title={Isolation and characterization of atypical Listeria monocytogenes associated with a canine urinary tract infection}, volume={28}, ISSN={1040-6387 1943-4936}, url={http://dx.doi.org/10.1177/1040638716661381}, DOI={10.1177/1040638716661381}, abstractNote={Listeria monocytogenes, a well-described cause of encephalitis and abortion in ruminants and of food-borne illness in humans, is rarely associated with disease in companion animals. A case of urinary tract infection associated with an atypical, weakly hemolytic L. monocytogenes strain is described in a diabetic dog. The serotype of the L. monocytogenes isolate was determined to be 1/2a (3a), with the multilocus genotyping pattern 2.72_1/2a. A nucleotide substitution (Gly145Asp) was detected at residue 145 in the promoter prfA region. This residue is within the critical helix-turn-helix motif of PrfA. The source of the L. monocytogenes strain remains unknown, and the dog recovered after a 4-week course of cephalexin (30 mg/kg orally twice daily).}, number={5}, journal={Journal of Veterinary Diagnostic Investigation}, publisher={SAGE Publications}, author={Palerme, Jean-Sébastien and Pan, Po Ching and Parsons, Cameron T. and Kathariou, Sophia and Ward, Todd J. and Jacob, Megan E.}, year={2016}, month={Aug}, pages={604–607} }
 @article{pritchard_jacob_ward_parsons_kathariou_wood_2016, title={Listeria monocytogenes septicemia in an immunocompromised dog}, volume={45}, ISSN={["1939-165X"]}, DOI={10.1111/vcp.12363}, abstractNote={Abstract}, number={2}, journal={VETERINARY CLINICAL PATHOLOGY}, author={Pritchard, Jessica C. and Jacob, Megan E. and Ward, Todd J. and Parsons, Cameron T. and Kathariou, Sophia and Wood, Michael W.}, year={2016}, month={Jun}, pages={254–259} }
 @article{tham_jacob_bizikova_2016, title={Molecular confirmation of shampoo as the putative source of Pseudomonas aeruginosa-induced postgrooming furunculosis in a dog}, volume={27}, ISSN={["1365-3164"]}, DOI={10.1111/vde.12332}, abstractNote={BackgroundAn acute onset furunculosis due to Pseudomonas aeruginosa following grooming is a well recognized entity. Although contaminated shampoos have been suspected to be the source of the infection, a molecular confirmation of this association has been missing.}, number={4}, journal={VETERINARY DERMATOLOGY}, author={Tham, Heng L. and Jacob, Megan E. and Bizikova, Petra}, year={2016}, month={Aug}, pages={320–E80} }
 @article{banovic_koch_robson_jacob_olivry_2015, title={Deep pyoderma caused by Burkholderia cepacia complex associated with ciclosporin administration in dogs: a case series}, volume={26}, ISSN={["1365-3164"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84955721179&partnerID=MN8TOARS}, DOI={10.1111/vde.12210}, abstractNote={BackgroundBacteria of the Burkholderia cepacia complex (Bcc) are ubiquitous Gram‐negative bacilli associated with fatal nosocomial infections in humans; multi‐antibiotic resistance makes this organism a serious threat in hospital settings.}, number={4}, journal={VETERINARY DERMATOLOGY}, author={Banovic, Frane and Koch, Sandra and Robson, David and Jacob, Megan and Olivry, Thierry}, year={2015}, month={Aug}, pages={287-+} }
 @article{jacob_hoppin_steers_davis_davidson_hansen_lunn_murphy_papich_2015, title={Opinions of clinical veterinarians at a US veterinary teaching hospital regarding antimicrobial use and antimicrobial-resistant infections}, volume={247}, ISSN={0003-1488}, url={http://dx.doi.org/10.2460/javma.247.8.938}, DOI={10.2460/javma.247.8.938}, abstractNote={Abstract}, number={8}, journal={Journal of the American Veterinary Medical Association}, publisher={American Veterinary Medical Association (AVMA)}, author={Jacob, Megan E. and Hoppin, Jane A. and Steers, Nicola and Davis, Jennifer L. and Davidson, Gigi and Hansen, Bernie and Lunn, Katharine F. and Murphy, K. Marcia and Papich, Mark G.}, year={2015}, month={Oct}, pages={938–944} }
 @article{foster_jacob_warren_papich_2015, title={Pharmacokinetics of enrofloxacin and ceftiofur in plasma, interstitial fluid, and gastrointestinal tract of calves after subcutaneous injection, and bactericidal impacts on representative enteric bacteria}, volume={39}, ISSN={0140-7783}, url={http://dx.doi.org/10.1111/jvp.12236}, DOI={10.1111/jvp.12236}, abstractNote={This study's objectives were to determine intestinal antimicrobial concentrations in calves administered enrofloxacin or ceftiofur sodium subcutaneously, and their impact on representative enteric bacteria. Ultrafiltration devices were implanted in the ileum and colon of 12 steers, which received either enrofloxacin or ceftiofur sodium. Samples were collected over 48 h after drug administration for pharmacokinetic/pharmacodynamic analysis. Enterococcus faecalis or Salmonella enterica (5 × 105 CFU/mL of each) were exposed in vitro to peak and tail (48 h postadministration) concentrations of both drugs at each location for 24 h to determine inhibition of growth and change in MIC. Enrofloxacin had tissue penetration factors of 1.6 and 2.5 in the ileum and colon, while ciprofloxacin, an active metabolite of enrofloxacin, was less able to cross into the intestine (tissue penetration factors of 0.7 and 1.7). Ceftiofur was rapidly eliminated leading to tissue penetration factors of 0.39 and 0.25. All concentrations of enrofloxacin were bactericidal for S. enterica and significantly reduced E. faecalis. Peak ceftiofur concentration was bactericidal for S. enterica, and tail concentrations significantly reduced growth. E. faecalis experienced growth at all ceftiofur concentrations. The MICs for both organisms exposed to peak and tail concentrations of antimicrobials were unchanged at the end of the study. Enrofloxacin and ceftiofur achieved intestinal concentrations capable of reducing intestinal bacteria, yet the short exposure of ceftiofur in the intestine may select for resistant organisms.}, number={1}, journal={Journal of Veterinary Pharmacology and Therapeutics}, publisher={Wiley}, author={Foster, D. M. and Jacob, M. E. and Warren, C. D. and Papich, M. G.}, year={2015}, month={May}, pages={62–71} }
 @article{jacob_foster_rogers_balcomb_sanderson_2015, title={Prevalence and relatedness of Escherichia coli O157:H7 strains in the feces and on the hides and carcasses of U.S. meat goats at slaughter (vol 79, pg 4154, 2013)}, volume={81}, number={1}, journal={Applied and Environmental Microbiology}, author={Jacob, M. E. and Foster, D. M. and Rogers, A. T. and Balcomb, C. C. and Sanderson, M. W.}, year={2015}, pages={462–462} }
 @article{jacob_bai_renter_rogers_shi_nagaraja_2014, title={Comparing Real-Time and Conventional PCR to Culture-Based Methods for Detecting and Quantifying Escherichia coli O157 in Cattle Feces}, volume={77}, ISSN={["1944-9097"]}, DOI={10.4315/0362-028x.jfp-13-304}, abstractNote={Detection of Escherichia coli O157 in cattle feces has traditionally used culture-based methods; PCR-based methods have been suggested as an alternative. We aimed to determine if multiplex real-time (mq) or conventional PCR methods could reliably detect cattle naturally shedding high (≥10(4) CFU/g of feces) and low (∼10(2) CFU/g of feces) concentrations of E. coli O157. Feces were collected from pens of feedlot cattle and evaluated for E. coli O157 by culture methods. Samples were categorized as (i) high shedders, (ii) immunomagnetic separation (IMS) positive after enrichment, or (iii) culture negative. DNA was extracted pre- and postenrichment from 100 fecal samples from each category (high shedder, IMS positive, culture negative) and subjected to mqPCR and conventional PCR assays based on detecting three genes, rfbE, stx1, and stx2. In feces from cattle determined to be E. coli O157 high shedders by culture, 37% were positive by mqPCR prior to enrichment; 85% of samples were positive after enrichment. In IMS-positive samples, 4% were positive by mqPCR prior to enrichment, while 43% were positive after enrichment. In culture-negative feces, 7% were positive by mqPCR prior to enrichment, and 40% were positive after enrichment. The proportion of high shedder-positive and culture-positive (high shedder and IMS) samples were significantly different from mqPCR-positive samples before and after enrichment (P < 0.01). Similar results were observed for conventional PCR. Our data suggest that mqPCR and conventional PCR are most useful in identifying high shedder animals and may not be an appropriate substitute to culture-based methods for detection of E. coli O157 in cattle feces.}, number={2}, journal={JOURNAL OF FOOD PROTECTION}, author={Jacob, M. E. and Bai, J. and Renter, D. G. and Rogers, A. T. and Shi, X. and Nagaraja, T. G.}, year={2014}, month={Feb}, pages={314–319} }
 @article{libraries_2014, title={Edwardsiella tarda and Aeromonas hydrophila isolated from diseased Southern flounder (Paralichthys lethostigma) are virulent to channel catfish and Nile tilapia}, volume={5}, ISSN={2309-5288 2309-6152}, url={http://dx.doi.org/10.12980/jclm.2.2014jclm-2014-0005}, DOI={10.12980/jclm.2.2014jclm-2014-0005}, journal={Journal of Coastal Life Medicine}, publisher={Asian Pacific Journal of Tropical Medicine Press}, author={Libraries, NC State University}, year={2014}, month={May} }
 @article{warren_prange_campbell_gerard_martin_jacob_smith_papich_foster_2014, title={Implantation of an ultrafiltration device in the ileum and spiral colon of steers to continuously collect intestinal fluid}, volume={97}, ISSN={0034-5288}, url={http://dx.doi.org/10.1016/j.rvsc.2014.10.012}, DOI={10.1016/j.rvsc.2014.10.012}, abstractNote={Collection of fluid from the lumen of the gastrointestinal tract is commonly necessary for research projects, but presents challenges including intestinal motility and potential for leakage of intestinal contents. In this study, ultrafiltration collection devices were surgically implanted in the ileum and spiral colon of 12 steers for repeated collection of intestinal fluid over 48 hours. There were no significant complications associated with surgery or during the post-operative period, nor were there any significant pathologic changes found at necropsy 3 or 4 days post-surgery. Over 48 hours, we obtained 88% of the desired 212 samples. Only two devices failed to routinely collect samples. Use of ultrafiltration probes is a novel, consistent and humane method to repeatedly sample the gastrointestinal contents.}, number={3}, journal={Research in Veterinary Science}, publisher={Elsevier BV}, author={Warren, Chelsea D. and Prange, Timo and Campbell, Nigel B. and Gerard, Mat P. and Martin, Luke G. and Jacob, Megan E. and Smith, Geof W. and Papich, Mark G. and Foster, Derek M.}, year={2014}, month={Dec}, pages={611–615} }
 @article{hutchins_vaden_jacob_harris_bowles_wood_bailey_2014, title={Vaginal Microbiota of Spayed Dogs with or without Recurrent Urinary Tract Infections}, volume={28}, ISSN={["1939-1676"]}, DOI={10.1111/jvim.12299}, abstractNote={BackgroundLimited information is available regarding the vaginal microbiota of normal spayed dogs and spayed dogs with recurrent UTIs. Vaginal lactic acid‐producing bacteria (LAB) have been associated with decreased frequency of recurrent urinary tract infection in women and may have a protective role within the urinary tract of female dogs.}, number={2}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={Hutchins, R. G. and Vaden, S. L. and Jacob, M. E. and Harris, T. L. and Bowles, K. D. and Wood, M. W. and Bailey, C. S.}, year={2014}, month={Mar}, pages={300–304} }
 @article{jacob_foster_rogers_balcomb_shi_nagaraja_2013, title={Evidence of Non-O157 Shiga Toxin-Producing Escherichia coli in the Feces of Meat Goats at a US Slaughter Plant}, volume={76}, ISSN={["1944-9097"]}, url={https://doi.org/10.4315/0362-028X.JFP-13-064}, DOI={10.4315/0362-028x.jfp-13-064}, abstractNote={Shiga toxin-producing Escherichia coli (STEC) are important human pathogens, and attention to non-O157 serogroups has increased in recent years. Although cattle are normally considered the primary reservoir for STEC, recent illnesses associated with goat contact have indicated that these animals are important potential reservoirs for the organisms. The prevalence of STEC, particularly non-O157 serogroups, in U.S. goats has not been well described. Our objective was to determine the prevalence of six major non-O157 STEC serogroups in the feces of meat goats. Rectal contents from 296 goats were collected postevisceration at a slaughter plant in the southeastern United States over 9 days during a 12-week period from August through October 2012. Samples were enriched in E. coli broth, and DNA was extracted and used as template in an 11-gene multiplex PCR that detected six non-O157 serogroups (O26, O45, O103, O121, O111, and O145) and virulence genes. Samples were considered positive when at least one non-O157 STEC serotype was present with either stx₁ or stx₂. All six non-O157 serogroups were detected by PCR in our samples, and 14.5% of samples were positive for at least one serogroup. Prevalence of O26 was highest, with 6.4% of goat fecal samples positive. The prevalence of O45 was 3.4%, O103 was 4.4%, O111 was 4.1%, O121 was 1.4%, and O145 was 3.0%. Twenty-two (7.4%) of 296 fecal samples had more than one non-O157 serogroup detected in the feces. Two samples had evidence of three non-O157 STEC serogroups. Goats appear to be an important reservoir for non-O157 STEC, and further work to understand the characteristics, epidemiology, and ecology of STEC in these animals is warranted.}, number={9}, journal={JOURNAL OF FOOD PROTECTION}, author={Jacob, M. E. and Foster, D. M. and Rogers, A. T. and Balcomb, C. C. and Shi, X. and Nagaraja, T. G.}, year={2013}, month={Sep}, pages={1626–1629} }
 @article{jacob_foster_rogers_balcomb_sanderson_2013, title={Prevalence and Relatedness of Escherichia coli O157:H7 Strains in the Feces and on the Hides and Carcasses of US Meat Goats at Slaughter}, volume={79}, ISSN={["1098-5336"]}, url={http://europepmc.org/articles/PMC3697551}, DOI={10.1128/aem.00772-13}, abstractNote={ABSTRACT}, number={13}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Jacob, M. E. and Foster, D. M. and Rogers, A. T. and Balcomb, C. C. and Sanderson, M. W.}, year={2013}, month={Jul}, pages={4154–4158} }
 @article{hutchins_bailey_jacob_harris_wood_saker_vaden_2013, title={The Effect of an Oral Probiotic Containing Lactobacillus, Bifidobacterium, and Bacillus Species on the Vaginal Microbiota of Spayed Female Dogs}, volume={27}, ISSN={["1939-1676"]}, DOI={10.1111/jvim.12174}, abstractNote={BackgroundRecurrent urinary tract infections (UTIs) are often difficult to treat. Vaginal colonization with lactic acid‐producing bacteria (LAB) is associated with reduced frequency of recurrent UTIs in women. Oral probiotics might help increase the prevalence of vaginal LAB and decrease the frequency of recurrent UTIs in dogs.}, number={6}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={Hutchins, R. G. and Bailey, C. S. and Jacob, M. E. and Harris, T. L. and Wood, M. W. and Saker, K. E. and Vaden, S. L.}, year={2013}, month={Nov}, pages={1368–1371} }
 @article{jacob_shi_an_nagaraja_bai_2012, title={Evaluation of a Multiplex Real-Time Polymerase Chain Reaction for the Quantification of Escherichia coli O157 in Cattle Feces}, volume={9}, ISSN={["1535-3141"]}, DOI={10.1089/fpd.2011.0947}, abstractNote={Cattle are asymptomatic reservoirs for Escherichia coli O157, a major foodborne pathogen. The organism generally colonizes the hindgut of cattle and is shed in the feces at low concentrations. The objective of this research was to evaluate a multiplex, real-time polymerase chain reaction (mqPCR) assay for quantification of E. coli O157 in cattle feces using stx1, stx2, and rfbE gene targets. Primer efficiency and analytical sensitivity of the assay were evaluated with a single or pooled (five strain) culture of E. coli O157. In pure culture, the minimum detection limit of the assay was 1.4×10(3) CFU/mL and 3.6×10(3) CFU/mL for the single and five-strain mixture of E. coli O157, respectively. Diagnostic sensitivity was analyzed using DNA extracted from cattle feces spiked with E. coli O157. In feces spiked with the pooled mixture of five E. coli O157 strains, the minimum detection limit was 3.6×10(4) CFU/g. We also evaluated the assay with feces from cattle experimentally inoculated with E. coli O157 by comparing the results to a culture-based method. For the majority of samples tested, the concentration of E. coli O157 detected by the real-time and culture methods was within one log difference. However, the assay could only be evaluated for cattle shedding high concentrations of E. coli O157. In conclusion, the mqPCR quantifying E. coli O157 in cattle feces using stx1, stx2, and rfbE gene targets may have use in detecting and quantifying super shedders, but is not applicable for quantification in animals shedding low concentrations (10(2) to 10(3) CFU/g feces).}, number={1}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Jacob, Megan E. and Shi, Xiaorong and An, Baoyan and Nagaraja, Tiruvoor G. and Bai, Jianfa}, year={2012}, month={Jan}, pages={79–85} }
 @article{jacob_almes_shi_sargeant_nagaraja_2011, title={Escherichia coli O157:H7 Genetic Diversity in Bovine Fecal Samples}, volume={74}, ISSN={["0362-028X"]}, DOI={10.4315/0362-028x.jfp-11-022}, abstractNote={Escherichia coli O157:H7 causes foodborne illness in humans; cattle are considered a primary reservoir for the organism, and transmission is often through contaminated food products or water. The objective of this study was to determine the genetic diversity of E. coli O157:H7 within a single individual bovine fecal sample based on pulsed-field gel electrophoresis (PFGE) typing. Fecal samples (n=601) were collected from dairy and beef cattle at three separate facilities, and E. coli O157:H7 was isolated by enrichment, immunomagnetic separation, and plating on selective medium. The prevalence of E. coli O157:H7 was 46 (7.7%) of 601. From each positive fecal sample, up to 10 putative colonies were tested, and isolates from samples with at least seven positive colonies were subtyped using PFGE and tested for six major virulence genes by multiplex PCR. A total of 254 E. coli O157:H7 isolates from 27 samples met these criteria and were included in PFGE analysis. Fifteen PFGE subtypes (<100% Dice similarity) were detected among the 254 isolates, and there were no common subtypes between the three locations. Seven (26%) of 27 fecal samples had E. coli O157:H7 isolates with different PFGE subtypes (mean=2.1) within the same sample. The virulence gene profiles of different isolates from the same sample were always identical, regardless of the number of PFGE types. The results of this study suggest that determining the PFGE pattern of a single isolate from a bovine sample may not be sufficient when comparing isolates from feces, hides, or carcasses, because multiple PFGE subtypes are present.}, number={7}, journal={JOURNAL OF FOOD PROTECTION}, author={Jacob, M. E. and Almes, K. M. and Shi, X. and Sargeant, J. M. and Nagaraja, T. G.}, year={2011}, month={Jul}, pages={1186–1188} }
 @article{dodd_sanderson_jacob_renter_2011, title={Modeling Preharvest and Harvest Interventions for Escherichia coli O157 Contamination of Beef Cattle Carcasses}, volume={74}, ISSN={0362-028X}, url={http://dx.doi.org/10.4315/0362-028x.jfp-10-516}, DOI={10.4315/0362-028x.jfp-10-516}, abstractNote={Field studies evaluating the effects of multiple concurrent preharvest interventions for Escherichia coli O157 are logistically and economically challenging; however, modeling techniques may provide useful information on these effects while also identifying crucial information gaps that can guide future research. We constructed a risk assessment model with data obtained from a systematic search of scientific literature. Parameter distributions were incorporated into a stochastic Monte Carlo modeling framework to examine the impacts of different combinations of preharvest and harvest interventions for E. coli O157 on the risk of beef carcass contamination. We estimated the risk of E. coli O157 carcass contamination conditional on preharvest fecal prevalence estimates, inclusion of feed additive(s) in the diet, vaccination for E. coli O157, transport and lairage effects, hide intervention(s), and carcass intervention(s). Prevalence parameters for E. coli O157 were assumed to encompass potential effects of concentration; therefore, concentration effects were not specifically evaluated in this study. Sensitivity analyses revealed that fecal prevalence, fecal-to-hide transfer, hide-to-carcass transfer, and carcass intervention efficacy significantly affected the risk of carcass contamination (correlation coefficients of 0.37, 0.56, 0.58, and -0.29, respectively). The results indicated that combinations of preharvest interventions may be particularly important for supplementing harvest interventions during periods of higher variability in fecal shedding prevalence (i.e., summer). Further assessments of the relationships among fecal prevalence and concentration, hide contamination, and subsequent carcass contamination are needed to further define risks and intervention impacts for E. coli O157 contamination of beef.}, number={9}, journal={Journal of Food Protection}, publisher={International Association for Food Protection}, author={Dodd, Charles C. and Sanderson, Michael W. and Jacob, Megan E. and Renter, David G.}, year={2011}, month={Sep}, pages={1422–1433} }
 @article{jacob_renter_nagaraja_2010, title={Animal- and Truckload-Level Associations between Escherichia coli O157:H7 in Feces and on Hides at Harvest and Contamination of Preevisceration Beef Carcasses}, volume={73}, ISSN={0362-028X}, url={http://dx.doi.org/10.4315/0362-028x-73.6.1030}, DOI={10.4315/0362-028x-73.6.1030}, abstractNote={Cattle feces and hides contribute to carcass contamination with Escherichia coli O157:H7, ultimately impacting beef safety. Primary objectives of our cross-sectional study were to evaluate associations among fecal, hide, and preevisceration carcass prevalence of E. coli O157:H7 and to assess factors affecting carcass contamination. Fecal, hide, and preevisceration carcass samples were collected from up to 32 cattle on each of 45 truckloads presented to a midwestern U.S. abattoir. Enrichment and selective culture were used to assess fecal, hide, and carcass prevalence, and direct plating was used to identify cattle shedding high levels of E. coli O157:H7 in feces. Fecal, hide, and carcass prevalence of E. coli O157:H7 within truckload were significantly correlated (P < 0.05) with each other. Enriched fecal sample prevalence was 13.8%, and high shedder prevalence was 3.3%; 38.5% of hides and 10.5% of carcasses were positive for E. coli O157:H7. We used logistic regression to assess animal- and truckload-level variables affecting the probability of carcasses testing positive for E. coli O157:H7. All truckload-level predictors significantly affected the probability of an E. coli O157:H7-positive carcass, including presence of a high shedder within the truckload (odds ratio [OR] = 4.0; confidence interval [CI], 1.6 to 10.1), high (>25%) within-truckload fecal prevalence (OR = 19.3; CI, 4.7 to 79.0), and high (>50%) within-truckload hide prevalence (OR = 7.7; CI, 3.1 to 19.6). The only significant animal-level predictor was having a positive hide (OR = 1.6; CI, 1.0 to 2.6). Our results suggest that preharvest interventions for reducing E. coli O157:H7 contamination of carcasses should focus on truckload (cohort)-level and hide mitigation strategies.}, number={6}, journal={Journal of Food Protection}, publisher={International Association for Food Protection}, author={Jacob, M. E. and Renter, D. G. and Nagaraja, T. G.}, year={2010}, month={Jun}, pages={1030–1037} }
 @article{jacob_fox_nagaraja_drouillard_amachawadi_narayanan_2010, title={Effects of Feeding Elevated Concentrations of Copper and Zinc on the Antimicrobial Susceptibilities of Fecal Bacteria in Feedlot Cattle}, volume={7}, ISSN={1535-3141 1556-7125}, url={http://dx.doi.org/10.1089/fpd.2009.0401}, DOI={10.1089/fpd.2009.0401}, abstractNote={Cattle are fed elevated concentrations of copper and zinc for growth promotion. The potential mechanisms of growth promotional effects of these elements are attributed to their antimicrobial activities, similar to that of antibiotics, in that gut microbial flora are altered to reduce fermentation loss of nutrients and to suppress gut pathogens. Copper and zinc fed at elevated concentrations may select for bacteria that are resistant not only to heavy metals but also to antibiotics. Our objectives were to determine the effects of feeding elevated copper and zinc on the antimicrobial susceptibilities of fecal bacteria in feedlot cattle. Twenty heifers, fed corn-based high-grain diets, were randomly assigned to treatments in a 2 x 2 factorial arrangement with 1X or 10X National Research Council recommended copper and/or zinc. Feces, collected on days 0, 14, and 32, were cultured for commensal bacteria (Escherichia coli and Enterococcus) to determine their susceptibilities to copper, zinc, and antibiotics. Fecal DNA was extracted to detect tcrB gene and quantify erm(B) and tet(M) genes. In E. coli and Enterococcus sp., minimal differences in minimum inhibitory concentrations (MICs) of copper, zinc, and antibiotics were noticed. The mean copper MIC for E. coli increased (p < 0.05) between days 0 and 32 and days 14 and 32. The only treatment effect detected was increased zinc MIC of E. coli isolates (p < 0.01). The tcrB gene was not detected in feces or in enterococcal isolates. Proportions of erm(B) and tet(M) were unaffected by copper or zinc supplementation. However, the proportion of tet(M) increased (p < 0.05) between days 0 and 14. Feeding elevated copper and/or zinc to feedlot cattle had marginal effects on antimicrobial susceptibilities of fecal E. coli and enterococci.}, number={6}, journal={Foodborne Pathogens and Disease}, publisher={Mary Ann Liebert Inc}, author={Jacob, Megan E. and Fox, J. Trent and Nagaraja, T.G. and Drouillard, James S. and Amachawadi, Raghavendra G. and Narayanan, Sanjeev K.}, year={2010}, month={Jun}, pages={643–648} }
 @article{jacob_paddock_renter_lechtenberg_nagaraja_2010, title={Inclusion of Dried or Wet Distillers' Grains at Different Levels in Diets of Feedlot Cattle Affects Fecal Shedding of Escherichia coli O157:H7}, volume={76}, ISSN={0099-2240}, url={http://dx.doi.org/10.1128/aem.01221-10}, DOI={10.1128/aem.01221-10}, abstractNote={ABSTRACT}, number={21}, journal={Applied and Environmental Microbiology}, publisher={American Society for Microbiology}, author={Jacob, M. E. and Paddock, Z. D. and Renter, D. G. and Lechtenberg, K. F. and Nagaraja, T. G.}, year={2010}, month={Sep}, pages={7238–7242} }
 @article{amachawadi_shelton_jacob_shi_narayanan_zurek_dritz_nelssen_tokach_nagaraja_2010, title={Occurrence of tcrB, a Transferable Copper Resistance Gene, in Fecal Enterococci of Swine}, volume={7}, ISSN={1535-3141 1556-7125}, url={http://dx.doi.org/10.1089/fpd.2010.0540}, DOI={10.1089/fpd.2010.0540}, abstractNote={High concentration of copper, fed as copper sulfate, is often used to increase growth rates in swine. Bacteria exposed to copper may acquire resistance, and in Enterococcus faecium and Enterococcus faecalis, a plasmid-borne transferable copper resistance (tcrB) gene that confers copper resistance has been reported. Our objectives were to determine the occurrence of tcrB in fecal enterococci from weaned piglets fed diets with a normal supplemental level (16.5 ppm) or an elevated supplemental level (125 ppm) of copper and to determine the association of tcrB with copper, erythromycin, and vancomycin resistance. A total of 323 enterococcal isolates were examined and 15 (4.6%) isolates (14 E. faecium and 1 E. faecalis) were positive for tcrB. Fifteen tcrB-positive and 15 randomly chosen tcrB-negative isolates from piglets fed the normal supplemental level of copper were tested for erm(B), tet(M), vanA, and vanB genes and susceptibilities to copper, erythromycin, tetracyclines, and vancomycin. All tcrB-positive and -negative isolates contained erm(B) and tet(M), but not vanA and vanB. The mean minimum inhibitory concentration of copper for tcrB-positive (21.1 mM) was higher (p < 0.001) compared with tcrB-negative isolates (6.1 mM). All isolates were resistant to erythromycin and tetracyclines and susceptible to vancomycin. The transferability of the tcrB gene from tcrB-positive strains to tcrB-negative strains was demonstrated by conjugation. The potential link between tcrB and antibiotic resistance genes and the propensity of enterococci to transfer tcrB to other strains raises the possibility that copper supplementation may exert selection pressure for antibiotic-resistant enterococci. This study is the first report on the occurrence of the tcrB gene in enterococci isolated from swine in the United States.}, number={9}, journal={Foodborne Pathogens and Disease}, publisher={Mary Ann Liebert Inc}, author={Amachawadi, Raghavendra G. and Shelton, Nick W. and Jacob, Megan E. and Shi, Xiaorong and Narayanan, Sanjeev K. and Zurek, Ludek and Dritz, Steve S. and Nelssen, Jim L. and Tokach, Mike D. and Nagaraja, T.G.}, year={2010}, month={Sep}, pages={1089–1097} }
 @article{jacob_callaway_nagaraja_2009, title={Dietary Interactions and Interventions Affecting Escherichia coli O157 Colonization and Shedding in Cattle}, volume={6}, ISSN={1535-3141 1556-7125}, url={http://dx.doi.org/10.1089/fpd.2009.0306}, DOI={10.1089/fpd.2009.0306}, abstractNote={Escherichia coli O157 is an important foodborne pathogen affecting human health and the beef cattle industry. Contamination of carcasses at slaughter is correlated to the prevalence of E. coli O157 in cattle feces. Many associations have been made between dietary factors and E. coli O157 prevalence in cattle feces. Preharvest interventions, such as diet management, could reduce the fecal prevalence and diminish the impact of this adulterant. Dietary influences, including grain type and processing method, forage quality, and distillers grains have all been associated with E. coli O157 prevalence. In addition, several plant compounds, including phenolic acids and essential oils, have been proposed as in-feed intervention strategies. The specific mechanisms responsible for increased or decreased E. coli O157 shedding or survival are not known but are often attributed to changes in hindgut ecology induced by diet types. Some interventions may have a direct bacterial effect. Frequently, results of studies are conflicting or not repeatable, which speaks to the complexity of the hindgut ecosystem, variation in animal feed utilization, and variation within feed products. Still, understanding specific mechanisms, driven by diet influences, responsible for E. coli O157 shedding will aid in the development and implementation of better and practical preharvest intervention strategies.}, number={7}, journal={Foodborne Pathogens and Disease}, publisher={Mary Ann Liebert Inc}, author={Jacob, Megan E. and Callaway, Todd R. and Nagaraja, T.G.}, year={2009}, month={Sep}, pages={785–792} }
 @article{jacob_fox_drouillard_renter_nagaraja_2009, title={Evaluation of Feeding Dried Distiller's Grains with Solubles and Dry-Rolled Corn on the Fecal Prevalence of Escherichia coli O157:H7 and Salmonella spp. in Cattle}, volume={6}, ISSN={1535-3141 1556-7125}, url={http://dx.doi.org/10.1089/fpd.2008.0159}, DOI={10.1089/fpd.2008.0159}, abstractNote={Escherichia coli O157:H7 and Salmonella are foodborne pathogens that reside in the gut of cattle and are shed in the feces. Previous work indicated a positive association between feeding cattle distiller's grains (DG) and an increase in E. coli O157:H7 prevalence. Feeding processed grains also has been shown to affect fecal prevalence of E. coli O157:H7. The objective of this study was to evaluate the effect of feeding DG and dry-rolled corn (DRC), alone or in combination, on fecal prevalence of E. coli O157:H7 and Salmonella in finishing cattle. Cattle were allotted to pens (n = 28), and fed dietary treatments (n = 150 days) structured in a 2 x 2 factorial arrangement; the factors were 0% or 25% dried corn DG with solubles (DDGS) and 0% or 25% DRC in steam-flaked corn-based high-grain diets. Fecal samples were collected from each pen floor before initiating dietary treatments and at least once every 2 weeks after final diets began. Overall prevalence of E. coli O157:H7 in fecal samples was 5.1%. There were no significant effects of DDGS, DRC, or sampling time on E. coli O157:H7 prevalence (p > 0.20). Overall prevalence of Salmonella in pen floor fecal samples was 23.7%, and sampling week affected prevalence (p < 0.01), ranging from < 1% (week 1) to 77.5% (week 17). Salmonella prevalence was not affected by cattle diet, and no work had previously reported an association between either DG or DRC and Salmonella prevalence. Lack of an association between E. coli O157:H7 prevalence and feeding DG or DRC is contrary to previous observations. Further research is needed to understand inconsistencies between studies of E. coli O157:H7 prevalence and potential associations with DG and grain-processing methods.}, number={2}, journal={Foodborne Pathogens and Disease}, publisher={Mary Ann Liebert Inc}, author={Jacob, Megan E. and Fox, James Trent and Drouillard, James S. and Renter, David G. and Nagaraja, T.G.}, year={2009}, month={Mar}, pages={145–153} }
 @article{jacob_fox_reinstein_nagaraja_2008, title={Antimicrobial Susceptibility of Foodborne Pathogens in Organic or Natural Production Systems: An Overview}, volume={5}, ISSN={1535-3141 1556-7125}, url={http://dx.doi.org/10.1089/fpd.2008.0095}, DOI={10.1089/fpd.2008.0095}, abstractNote={Organic and natural food production systems are increasing in popularity, at least partially because consumers perceive that these niche markets provide healthier and safer food products. One major difference between these niche markets and conventional production systems is the use of antimicrobials. Because antimicrobial agents exert selective pressures for antimicrobial resistance, relating antimicrobial susceptibility of foodborne bacteria to niche market production systems is of interest. Other differences between production systems might also influence the susceptibility of foodborne pathogens. The objective of this review is to compare the impact of food animal production systems on the antimicrobial susceptibility of common foodborne bacterial pathogens. Studies comparing the susceptibility of such pathogens were diverse in terms of geographic location, procedures, species of bacteria, and antimicrobials evaluated; thus, it was difficult to draw conclusions. The literature is highly variable in terms of production type and practices and susceptibility associations, although few studies have compared truly organic and conventional practices. When statistical associations were found between production type and minimum inhibitory concentrations or percentage of isolates resistant for a particular pathogen, the isolates from conventionally reared animals/products were more commonly resistant than the comparison group (organic, antibiotic free, etc.). Therefore, further studies are needed to better assess public health consequences of antimicrobial resistance and food animal production systems, specifically organic or natural versus conventional.}, number={6}, journal={Foodborne Pathogens and Disease}, publisher={Mary Ann Liebert Inc}, author={Jacob, Megan E. and Fox, James Trent and Reinstein, Shelby L. and Nagaraja, T.G.}, year={2008}, month={Dec}, pages={721–730} }
 @article{jacob_fox_narayanan_drouillard_renter_nagaraja_2008, title={Effects of feeding wet corn distillers grains with solubles with or without monensin and tylosin on the prevalence and antimicrobial susceptibilities of fecal foodborne pathogenic and commensal bacteria in feedlot cattle1}, volume={86}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/jas.2007-0091}, DOI={10.2527/jas.2007-0091}, abstractNote={Distillers grains, a coproduct of ethanol production from cereal grains, are composed principally of the bran, protein, and germ fractions and are commonly supplemented in ruminant diets. The objective of this study was to assess the effect of feeding wet distillers grains with solubles (WDGS) and monensin and tylosin on the prevalence and antimicrobial susceptibilities of fecal foodborne and commensal bacteria in feedlot cattle. Cattle were fed 0 or 25% WDGS in steam-flaked corn-based diets with the addition of no antimicrobials, monensin, or monensin and tylosin. Fecal samples were collected from each animal (n = 370) on d 122 and 136 of the 150-d finishing period and cultured for Escherichia coli O157. Fecal samples were also pooled by pen (n = 54) and cultured for E. coli O157, Salmonella, commensal E. coli, and Enterococcus species. Antimicrobial resistance was assessed by determining antimicrobial susceptibilities of pen bacterial isolates and quantifying antimicrobial resistance genes in fecal samples by real-time PCR. Individual animal prevalence of E. coli O157 in feces collected from cattle fed WDGS was greater (P < 0.001) compared with cattle not fed WDGS on d 122 but not on d 136. There were no treatment effects on the prevalence of E. coli O157 or Salmonella spp. in pooled fecal samples. Antimicrobial susceptibility results showed Enterococcus isolates from cattle fed monensin or monensin and tylosin had greater levels of resistance toward macrolides (P = 0.01). There was no effect of diet or antimicrobials on concentrations of 2 antimicrobial resistance genes, ermB or tetM, in fecal samples. Results from this study indicate that WDGS may have an effect on the prevalence of E. coli O157 and the concentration of selected antimicrobial resistance genes, but does not appear to affect antimicrobial susceptibility patterns in Enterococcus and generic E. coli isolates.}, number={5}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Jacob, M. E. and Fox, J. T. and Narayanan, S. K. and Drouillard, J. S. and Renter, D. G. and Nagaraja, T. G.}, year={2008}, month={May}, pages={1182–1190} }
 @article{jacob_parsons_shelor_fox_drouillard_thomson_renter_nagaraja_2008, title={Feeding Supplemental Dried Distiller’s Grains Increases Faecal Shedding of Escherichia coli O157 in Experimentally Inoculated Calves}, volume={55}, ISSN={1863-1959 1863-2378}, url={http://dx.doi.org/10.1111/j.1863-2378.2008.01115.x}, DOI={10.1111/j.1863-2378.2008.01115.x}, abstractNote={Summary}, number={3}, journal={Zoonoses and Public Health}, publisher={Wiley}, author={Jacob, M. E. and Parsons, G. L. and Shelor, M. K. and Fox, J. T. and Drouillard, J. S. and Thomson, D. U. and Renter, D. G. and Nagaraja, T. G.}, year={2008}, month={Apr}, pages={125–132} }
 @article{fox_reinstein_jacob_nagaraja_2008, title={Niche Marketing Production Practices for Beef Cattle in the United States and Prevalence of Foodborne Pathogens}, volume={5}, ISSN={1535-3141 1556-7125}, url={http://dx.doi.org/10.1089/fpd.2008.0094}, DOI={10.1089/fpd.2008.0094}, abstractNote={Niche-marketed food products are rapidly gaining market share in today's society. Consumers are willing to pay premium prices for food perceived to be safer, healthier, more nutritious, and better tasting than conventional food. This review outlines typical production practices for niche-market beef production systems in the United States and compares prevalence estimates of foodborne pathogens in animals and produce from conventional and niche-market production systems. The two main niches for food animal production are organic and natural productions. Organic and natural beef productions are becoming increasingly popular and there is high consumer demand. Two major differences between conventional beef production systems and niche-market production systems (natural and organic) are in the use of antimicrobials and growth-promoting hormones. The impacts of these production systems on foodborne pathogens in beef cattle are variable and often data are nonexistent. Studies directly comparing conventional and niche-market production systems for dairy, swine, poultry, and produce have observed that the prevalence of foodborne pathogens was seldom statistically different between production systems, but when differences were observed, prevalence was typically greater for the niche-market production systems than the conventional production system. The published literature suggests that the perception of niche-marketed food products being safer and healthier for consumers with regard to foodborne pathogens may not be justified.}, number={5}, journal={Foodborne Pathogens and Disease}, publisher={Mary Ann Liebert Inc}, author={Fox, J. Trent and Reinstein, Shelby and Jacob, Megan E. and Nagaraja, T.G.}, year={2008}, month={Oct}, pages={559–569} }
 @article{jacob_fox_drouillard_renter_nagaraja_2007, title={Effects of Dried Distillers' Grain on Fecal Prevalence and Growth of Escherichia coli O157 in Batch Culture Fermentations from Cattle}, volume={74}, ISSN={0099-2240}, url={http://dx.doi.org/10.1128/aem.01842-07}, DOI={10.1128/aem.01842-07}, abstractNote={ABSTRACT}, number={1}, journal={Applied and Environmental Microbiology}, publisher={American Society for Microbiology}, author={Jacob, M. E. and Fox, J. T. and Drouillard, J. S. and Renter, D. G. and Nagaraja, T. G.}, year={2007}, month={Oct}, pages={38–43} }