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Carbapenem-resistant bacteria (CRB) present a significant global public health concern. Sub-Saharan Africa has borne a heavy burden of CRB with a reported prevalence of up to 60% in some patient populations. es in Africa focus on clinical CRB isolates, with limited data on their spread in the natural environment. Therefore, the purpose of this study was to report the recovery of CRB from Nairobi River surface waters and nearby anthropogenic and zoonotic sources in Nairobi County, Kenya. A total of 336 CRB were recovered from 336 (250 mL) samples, with 230 of the samples (68.5%) producing one or more CRB isolates. CRB were recovered most commonly from untreated sewage influent (100% of 36 samples; 79 total isolates), treated effluent (93% of 118 samples; 116 total isolates), Nairobi River surface waters upstream (100% of 36 samples; 57 total isolates), downstream (100% of 36 samples; 45 total isolates), and way downstream from the wastewater treatment plant (73% of 11 samples; 19 total isolates), slaughterhouse effluent discharges 1.5%, (5/336), animal contact areas 0.9%, (3/336), a manhole sewer from the affluent neighborhood of Karen at 2.7%, (9/336) respectively. The CRB included Escherichia coli (158, 47%), Klebsiella pneumoniae (74, 22%), and Enterobacter spp (43, 13%). Aeromonas spp (29, 9%) Acinetobacter baumannii (12, 3.6%), Citrobacter freundii (7, 2.1%), Pseudomonas aeruginosa (5, 1.5%) and other species (8, 2.4%). CRB genotypes included blaNDM (246, 73.2%), blaKPC (40, 12%), blaVIM (51, 15.2%), blaOXA-48-like (65, 19.3%), blaIMP (15, 4.5%), and blaGES (7, 2.1%). Sixty-nine of the CRB isolates (20.5%) harbored multiple carbapenemase-encoding genes. Our results indicate that clinically important CRB are commonly present in Nairobi River surface water and from nearby wastewater and livestock sources. These pose an important public health threat that requires urgent intervention strategies and additional investigation., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

The global food trade provides a means of disseminating antimicrobial resistant (AMR) bacteria and genes. Using selective media, carbapenem-resistant species of Enterobacterales ( Providencia sp. and Citrobacter sp.), were detected in a single package of imported frozen shrimp purchased from a grocery store in Ohio, USA. Polymerase chain reaction confirmed that both isolates harbored bla NDM-1 genes. Following PacBio long read sequencing, the sequences were annotated using the NCBI Prokaryotic Genome Annotation Pipeline. The bla NDM-1 genes were found in IncC plasmids, each with different antimicrobial resistance island configuration. We found that the bla NDM-1 AMR islands had close relationships with previously reported environmental, food, and clinical isolates detected in Asia and the United States, highlighting the importance of the food chain in the global dissemination of antimicrobial resistance.

Since their commercialization, scientists have known that antimicrobial use kills or inhibits susceptible bacteria while allowing resistant bacteria to survive and expand. Today there is widespread antimicrobial resistance (AMR), even to antimicrobials of last resort such as the carbapenems, which are reserved for use in life-threatening infections. It is often convenient to assign responsibility for this global health crisis to the users and prescribers of antimicrobials. However, we know that animals never treated with antimicrobials carry clinically relevant AMR bacteria and genes. The causal pathway from bacterial susceptibility to resistance is not simple, and dissemination is cyclical rather than linear. Amplification of AMR occurs in healthcare environments and on farms where frequent exposure to antimicrobials selects for resistant bacterial populations. The recipients of antimicrobial therapy release antimicrobial residues, resistant bacteria, and resistance genes in waste products. These are reduced but not removed during wastewater and manure treatment and enter surface waters, soils, recreational parks, wildlife, and fields where animals graze and crops are grown for human and animal consumption. The cycle is complete when a patient carrying AMR bacteria is treated with antimicrobials that amplify the resistant bacterial populations. Reducing the development and spread of AMR requires a One Health approach with the combined commitment of governments, medical and veterinary professionals, agricultural industries, food and feed processors, and environmental scientists. In this review and in the companion Currents in One Health by Ballash et al, JAVMA, April 2024, we highlight just a few of the steps of the complex cyclical causal pathway that leads to the amplification, dissemination, and maintenance of AMR.

Once considered to be a simple cause-and-effect relationship with localized impact, the concept of how antimicrobial use drives antimicrobial resistance is now recognized as a complex, transdisciplinary problem on a global scale. While the issue of antimicrobial resistance is often studied and addressed at the antimicrobial-human or antimicrobial-animal treatment interface, the role of the environment in the One Health dynamics of antimicrobial resistance is not as well understood. Antimicrobial-resistant bacteria, including those resistant to carbapenem drugs, are emerging in veterinary clinical environments, on farms, and in natural habitats. These multidrug-resistant bacteria can colonize our livestock and companion animals and are later disseminated into the environment, where they contaminate surface waters and colonize wildlife. From here, the One Health transmission cycle of antimicrobial-resistant bacteria is completed as environmental reservoirs can serve as sources of antimicrobial resistance transmission into human or animal healthcare settings. In this review, we utilize a One Health perspective to evaluate how environments become contaminated and, in turn, become reservoirs that can colonize and infect our veterinary species, and how the veterinary field is combating environmental contamination with antimicrobial stewardship regulations and program implementation. The companion Currents in One Health by Parker et al, AJVR, April 2024, addresses the intensive research that justifies this One Health cycle of antimicrobial resistance transmission and emerging techniques that are dissecting the complex interactions at the One Health interface.

Antibiotic therapy is the standard of care for urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC). However, previous antibiotic therapy may impart a selective pressure that influences the population structure and pathogenic potential of infecting UPEC strains. Here, we conducted a 3-year study using whole-genome-sequencing analysis and retrospective medical record review to characterize how antibiotic exposure influenced the phenotypic antibiotic resistance, acquired resistome, virulome, and population structure of 88 UTI-causing E. coli strains from dogs. A majority of UTI-associated E. coli strains were from phylogroup B2 and clustered within sequence type 372. Previous antibiotic exposure was associated with a population shift toward UPEC from phylogroups other than the typical urovirulent phylogroup B2. The specific virulence profiles within the accessory virulome that were associated with antibiotic use were elicited by the effect of antibiotics on UPEC phylogenetic structure. Among phylogroup B2, antibiotic exposure increased the quantity of genes within the resistome and the odds of developing reduced susceptibility to at least one antibiotic. Non-B2 UPEC strains harbored a more diverse and greater resistome that conferred reduced susceptibility to multiple antibiotic classes following antibiotic exposure. Collectively, these data suggest that previous antibiotic exposure establishes an environment that provides a selective edge to non-B2 UPEC strains through their diverse and abundant antibiotic resistance genes, despite their lack of urovirulence genes. Our findings highlight the necessity for judicious use of antibiotics as we uncover another mechanism by which antibiotic exposure and resistance can influence the dynamics of bacterial infectious disease. IMPORTANCE Urinary tract infections (UTIs) are one of the most common infections of dogs and humans. While antibiotic therapy is the standard of care for UTIs and other infections, antibiotic exposure may influence the pathogenic profile of subsequent infections. We used whole-genome sequencing and retrospective medical record review to characterize the effect of systemic antibiotic therapy on the resistance, virulence, and population structure of 88 UTI-causing UPEC strains isolated from dogs. Our results indicate that antibiotic exposure alters the population structure of infecting UPEC strains, providing a selective edge for non-B2 phylogroups that harbor diverse and abundant resistance gene catalogues but fewer urovirulence genes. These findings highlight how antibiotic resistance can influence pathogen infection dynamics and have clinical implications for the judicious use of antibiotics for bacterial infections., Competing Interests: The authors declare no conflict of interest.

Environmental surfaces can serve as reservoirs for pathogens and antimicrobial-resistant (AMR) bacteria in healthcare settings. Although active surveillance programs are used in veterinary and human healthcare, unconventional settings like zoological facilities are often overlooked, even though antimicrobials are used to maintain the health of their animal collections. Here, we used electrostatic cloths to conduct active environmental surveillance over a 2-year period at two zoological institutions to determine contamination prevalence of human-only and mixed animal-human touch environments with AMR bacteria. We recovered Enterobacterales isolates that expressed quinolone resistance, an AmpC-like phenotype, and an extended-spectrum β-lactamase phenotype from 144 (39%), 141 (38.2%), and 72 (19.5%) of the environmental samples, respectively. The zoological institutions, areas and exhibits within the zoological facility, and sampling surface type affected the odds of recovering AMR bacteria from the environment. Three carbapenemase-producing Enterobacter cloacae complex ST171 isolates recovered from one zoological facility harbored an IncH12 plasmid with a Tn 4401b -KPC-4 transposon conferring multidrug resistance. One isolate maintained three tandem repeats of a Tn 4401b -KPC-4 element on an IncHI2 plasmid, although this isolate was susceptible to the four carbapenem drugs tested. These three isolates and their IncH12 plasmids shared significant genomic similarity with two E. cloacae complex isolates recovered from canine patients at a regional veterinary hospital during year 2 of this study. Our results indicated that surface environments at zoological institutions can serve as reservoirs for AMR bacteria and their genes and have implications for animal and public health. IMPORTANCE Environmental surfaces can be a source of antimicrobial-resistant (AMR) bacteria that pose a risk to human and animal health. Zoological institutions are unique environments where exotic animals, staff, and visitors intermingle and antimicrobials are used to maintain animal health. However, zoological environments are often overlooked as reservoirs of AMR bacteria. Here, we show that zoological environments can serve as reservoirs of fluoroquinolone-resistant and extended-spectrum cephalosporin-resistant bacteria. In addition, we isolated three carbapenemase-producing Enterobacter cloacae complex strains carrying bla KPC-4 , including one with a unique, tandem triplicate of the Tn 4401b -KPC-4 element. Comparative whole genomics of these isolates with two E. cloacae complex isolates from patients at a regional veterinary hospital highlighted the possibility of local KPC-4 spread between animal environments. Our results suggest that environments at zoological institutions serve as reservoirs for AMR bacteria and pose a hypothetical One Health risk to the public, staff, and the wild animal populations in captivity., Competing Interests: The authors declare no conflict of interest.

Concern about zoonoses and wildlife has increased. Few studies described the role of wild mammals and environments in the epidemiology of Salmonella . Antimicrobial resistance is a growing problem associated with Salmonella that threatens global health, food security, the economy, and development in the 21st century. The aim of this study is to estimate the prevalence and identify antibiotic susceptibility profiles and serotypes of non-typhoidal Salmonella enterica recovered from non-human primate feces, feed offered, and surfaces in wildlife centers in Costa Rica. A total of 180 fecal samples, 133 environmental, and 43 feed samples from 10 wildlife centers were evaluated. We recovered Salmonella from 13.9% of feces samples, 11.3% of environmental, and 2.3% of feed samples. Non-susceptibility profiles included six isolates from feces (14.6%): four non-susceptible isolates (9.8%) to ciprofloxacin, one (2.4%) to nitrofurantoin, and one to both ciprofloxacin and nitrofurantoin (2.4%). Regarding the environmental samples, one profile was non-susceptible to ciprofloxacin (2.4%) and two to nitrofurantoin (4.8%). The serotypes identified included Typhimurium/I4,[5],12:i:-, S . Braenderup/Ohio, S . Newport, S . Anatum/Saintpaul, and S . Westhampton. The epidemiological surveillance of Salmonella and antimicrobial resistance can serve in the creation of strategies for the prevention of the disease and its dissemination throughout the One Health approach.

Salmonella enterica serovar Agona is commonly detected in raw animal feed components during routine microbial monitoring of Australian commercial animal feed mills. We hypothesized that Salmonella -contaminated raw feed components originate at the rendering or oil seed crushing plant and are distributed to mills in different locations. Our objective was to investigate the source of Salmonella Agona contaminated raw feed components. Whole genome sequences of 37 Salmonella Agona isolates, 36 from raw feed components and 1 from finished feed, collected from 10 Australian feed mills located in 4 Australian states, were compared using core genome phylogenetic analysis. After DNA extraction and de novo draft assembly of the paired reads, the draft genomes were aligned using conserved signature indel phylogeny against a reference genome for Salmonella Agona, to identify single nucleotide polymorphisms in the core genome. Five distinct clades corresponding to the five different suppliers of Salmonella Agona-contaminated raw feed components were identified in the resulting phylogenetic tree. The results also provided evidence of cross-transference of Salmonella Agona between canola meal, meat meal, and finished feed within a mill. Core genome phylogenetic analysis facilitated tracing the source of Salmonella contamination in feed mills.

As safe agents of last resort, carbapenems are reserved for the treatment of infections caused by multidrug-resistant organisms. The impact of β-lactam antibiotics, cefotaxime, and meropenem on the frequency and diversity of carbapenemase-producing organisms recovered from environmental samples has not been fully established. Therefore, this methodological study aimed at determining β-lactam drugs used in selective enrichment and their impact on the recovery of carbapenemase-producing Enterobacterales (CPE) from untreated wastewater. We used a longitudinal study design where 1L wastewater samples were collected weekly from wastewater treatment plant (WWTP) influent and quarterly from contributing sanitary sewers in Columbus, Ohio USA with 52 total samples collected. Aliquots of 500 mL were passed through membrane filters of decreasing pore sizes to enable all the water to pass through and capture bacteria. For each sample, the resulting filters were placed into two modified MacConkey (MAC) broths, one supplemented with 0.5 μg/mL of meropenem and 70 μg/mL of ZnSO4 and the other supplemented with 2 μg/mL cefotaxime. The inoculated broth was then incubated at 37° C overnight, after which they were streaked onto two types of correspondingly-modified MAC agar plates supplemented with 0.5 μg/mL and 1.0 μg/mL of meropenem and 70 μg/mL of ZnSO4 and incubated at 37°C overnight. The isolates were identified based on morphological and biochemical characteristics. Then, up to four distinct colonies of each isolate's pure culture per sample were tested for carbapenemase production using the Carba-NP test. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) MALDI-TOF MS was used to identify carbapenemase-producing organisms. In total 391 Carba-NP positive isolates were recovered from the 52 wastewater samples: 305 (78%) isolates had blaKPC, 73 (19%) carried blaNDM, and 14 (4%) harbored both blaKPC and blaNDM resistance genes. CPE genes of both blaKPC and blaNDM were recovered in both types of modified MAC broths, with 84 (21%) having a blaKPC gene, 22 (6%) carrying blaNDM and 9 (2%) harbored both a blaKPC and blaNDM of isolates recovered from MAC medium incorporated with 0.5ug/mL meropenem and 70ug/mL ZnSO4. The most prevalent isolates were Klebsiella pneumoniae, Escherichia coli, and Citrobacter spp., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Abstract: Studies of red swamp crayfish (Procambarus clarkii) outside of the United States confirm the presence of a variety of zoonotic pathogens, but it is unknown whether these same pathogens occur in P. clarkii in the United States. The U.S. commercial crayfish industry generates $200 million yearly, underscoring the need to evaluate this consumer commodity. The study objectives were to evaluate specific zoonotic pathogens present on P. clarkii from Alabama and Louisiana, states in the southeastern United States, and to determine the effectiveness of traditional food preparation methods to reduce pathogens. Experiment A evaluated the presence of Escherichia coli, Salmonella, Staphylococcus aureus, and Vibrio spp. in crayfish and environmental samples over a 2-month collection period (May to June 2021). Crayfish sampling consisted of swabbing the cephalothorax region; 15 samples were tested for E. coli, Salmonella, and S. aureus, and an additional 15 samples for Vibrio spp. Additionally, crayfish shipping materials were sampled. In experiment B, 92 crayfish were evaluated for Paragonimus kellicotti. Experiment C compared live and boiled crayfish for the presence of Vibrio spp. In experiments A and B, all 60 (100%) crayfish samples and 13 (81.25%) of 16 environmental samples showed growth characteristic of Vibrio spp. Three (5%) of 60 samples showed E. coli growth, with no statistical difference (P = 0.5536) between farms. P. kellicotti, Salmonella, and S. aureus were not recovered from any samples. In experiment C, all 10 (100%) of the live preboiled crayfish samples showed characteristic growth, whereas 1 (10%) of 10 samples of crayfish boiled in unseasoned water showed Vibrio growth (P < 0.0001). These results confirm that Vibrio spp. and E. coli may be present on U.S. commercial crayfish and that care should be taken when handling any materials that come into contact with live crayfish because they can potentially be contaminated., (Copyright ©, International Association for Food Protection.)

Surface waters, especially those receiving wastewater flows, can disseminate antimicrobial resistant bacteria (ARB), antimicrobial resistance genes (ARG), and antibiotics. In the Scioto River of central Ohio, United States, we evaluated fishes as potential sentinels of ARB and antimicrobial contamination and investigated the influence of antimicrobial exposure on the fish intestinal resistome. Seventy-seven fish were collected from river reaches receiving inputs from two wastewater treatment plants that serve the greater Columbus Metropolitan Area. Fish were screened for the presence of cephalosporin-resistant (CeRO) and carbapenem-resistant (CRO) organisms, epidemic carbapenemase genes, and antibiotic drugs and metabolites using culture methods, droplet digital PCR, and ultra-high performance liquid chromatography tandem mass spectroscopy (UHPLC-MS/MS). Nearly 21% of fish harbored a CeRO in their resistome, with 19.4% exhibiting bacteria expressing an AmpC genotype encoded by blaCMY, and 7.7% with bacteria expressing an extended-spectrum β-lactamase phenotype encoded by blaCTX-M. blaKPC and blaNDM were present in 87.7% (57/65) and 80.4% (37/46) of the intestinal samples at an average abundance of 104 copies. Three antibiotics-lincomycin (19.5%), azithromycin (31.2%) and sulfamethoxazole (3.9%)-were found in hepatic samples at average concentrations between 25-31 ng/g. Fish harboring blaCTX-M and those exposed to azithromycin were at greater odds of being downstream of a wastewater treatment plant. Fish that bioconcentrated antibiotics in their liver were not at greater odds of harboring CeRO, CRO, or epidemic carbapenemase gene copies in their resistome. Our findings confirm that fishes can be effective bioindicators of surface waters contaminated with ARB, ARG, and antibiotics. Moreover, our findings highlight the varying importance of different mechanisms that facilitate establishment of ARB in aquatic ecosystems., Competing Interests: The authors have declared that no competing interests exist.

Biofilm formation enhances bacteria's ability to colonize unique niches while protecting themselves from environmental stressors. Escherichia coli that colonize the urinary tract can protect themselves from the harsh bladder environment by forming biofilms. These biofilms promote persistence that can lead to chronic and recurrent urinary tract infections (UTI). While biofilm formation is frequently studied among urinary E. coli, its association with other pathogenic mechanisms and adaptations in certain host populations remains poorly understood. Here we utilized whole genome sequencing and retrospective medical record analysis to investigate associations between the population structure, phenotypic resistance, resistome, virulome, and patient demographic and clinical findings of 104 unique urinary E. coli and their capacity to form biofilms. We show that population structure including multilocus sequence typing and Clermont phylogrouping had no association with biofilm capacity. Among clinical factors, exposure to multiple antibiotics within that past 30 days and a clinical history of recurrent UTIs were positively associated with biofilm formation. In contrast, phenotypic antimicrobial reduced susceptibility and corresponding acquired resistance genes were negatively associated with biofilm formation. While biofilm formation was associated with increased virulence genes within the cumulative virulome, individual virulence genes did not influence biofilm capacity. We identified unique virulotypes among different strata of biofilm formation and associated the presence of the tosA/R-ibeA gene combination with moderate to strong biofilm formation. Our findings suggest that E. coli causing UTI in dogs utilize a heterogenous mixture of virulence genes to reach a biofilm phenotype, some of which may promote robust biofilm capacity. Antimicrobial use may select for two populations, non-biofilm formers that maintain an arsenal of antimicrobial resistance genes to nullify treatment and a second that forms durable biofilms to avoid therapeutic insults., Competing Interests: The authors have declared that no competing interests exist.

Objective: To identify important risk factors for carbapenem-resistant Enterobacterales (CRE) infections among hospitalized patients., Design: We utilized a case-case-control design that compared patients with CRE infections to patients with carbapenem-susceptible Enterobacterales (CSE) infections and randomly selected controls during the period from January 2011 through December 2016., Setting: The study population was selected from patients at a large metropolitan tertiary-care and instructional medical center., Patients: Cases of CRE were defined as initial admission of adults diagnosed with a bacterial infection of an Enterobacterales species resistant clinically or through sensitivity testing to carbapenems 48 hours or more after admission. Cases of CSE were selected from the same patient population as the CRE cases within a 30-day window for admission, with diagnostic pathogens identified as susceptible to carbapenems. Controls were defined as adult patients admitted to any service within a 30-day window from a CRE case for >48 hours who did not meet either of the above case definitions during that admission., Results: Antibiotic exposure within 90 days prior to admission and length of hospital stay were both associated with increased odds of CRE and CSE infections compared to controls. Patients with CRE infections had >18 times greater odds of prior antibiotic exposure compared to patients with CSE infections., Conclusions: Antibiotic exposure and increased length of hospital stay may result in increased patient risk of developing an infection resistant to carbapenems and other β-lactams., (© The Author(s) 2022.)

Wildlife play a role in the acquisition, maintenance, and dissemination of antimicrobial resistance (AMR). This is especially true at the human-domestic animal-wildlife interface, like urbanized areas, where interactions occur that can promote the cross-over of AMR bacteria and genes. We conducted a 2-year fecal surveillance ( n  = 783) of a white-tailed deer (WTD) herd from an urban park system in Ohio to identify and characterize cephalosporin-resistant and carbapenemase-producing bacteria using selective enrichment. Using generalized linear mixed models we found that older (OR = 2.3, P  < 0.001), male (OR = 1.8, P  = 0.001) deer from urbanized habitats (OR = 1.4, P  = 0.001) were more likely to harbor extended-spectrum cephalosporin-resistant Enterobacterales. In addition, we isolated two carbapenemase-producing Enterobacterales (CPE), a Klebsiella quasipneumoniae harboring bla KPC-2 and an Escherichia coli harboring bla NDM-5 , from two deer from urban habitats. The genetic landscape of the plasmid carrying bla KPC-2 was unique, not clustering with other reported plasmids encoding KPC-2, and only sharing 78% of its sequence with its nearest match. While the plasmid carrying bla NDM-5 shared sequence similarity with other reported plasmids encoding NDM-5, the intact IS26 mobile genetic elements surrounding multiple drug resistant regions, including the bla NDM-5 , has been reported infrequently. Both carbapenemase genes were successfully conjugated to a J53 recipient conferring a carbapenem-resistant phenotype. Our findings highlight that urban environments play a significant role on the transmission of AMR bacteria and genes to wildlife and suggest WTD may play a role in the dissemination of clinically and epidemiologically relevant antimicrobial resistant bacteria. IMPORTANCE The role of wildlife in the spread of antimicrobial resistance is not fully characterized. Some wildlife, including white-tailed deer (WTD), can thrive in suburban and urban environments. This may result in the exchange of antimicrobial resistant bacteria and resistance genes between humans and wildlife, and lead to their spread in the environment. We found that WTD living in an urban park system carried antimicrobial resistant bacteria that were important to human health and resistant to antibiotics used to treat serious bacterial infections. This included two deer that carried bacteria resistant to carbapenem antibiotics which are critically important for treatment of life-threatening infections. These two bacteria had the ability to transfer their AMR resistance genes to other bacteria, making them a threat to public health. Our results suggest that WTD may contribute to the spread of antimicrobial resistant bacteria in the environment.

Salmonella contamination of livestock feed is a serious veterinary and public health issue. In this study we used a systematic review to assess the prevalence and characterization of Salmonella isolates detected in raw feed components, feed milling equipment and finished feed from 97 studies published from 1955 to 2020 across seven global regions. Eighty-five studies were included in a meta-analyses to estimate the combined prevalence of Salmonella detection and to compare the risk of contamination associated with different sample types. We found the overall combined prevalence estimate of Salmonella detection was 0.14 with a prevalence of 0.18 in raw feed components, 0.09 in finished feed and 0.08 in feed milling equipment. Animal based raw feed components were 3.9 times more likely to be contaminated with Salmonella than plant based raw feed components. Differences between studies accounted for 99 % of the variance in the prevalence estimate for all sample types and there was no effect of region on the prevalence estimates. The combined prevalence of Salmonella detection in raw feed components decreased from 0.25 in 1955 to 0.11 in 2019. The proportion of Salmonella isolates that were resistant to antimicrobials was largest for amikacin (0.20), tetracycline (0.18) streptomycin (0.17), cefotaxime (0.14) and sulfisoxazole (0.11). The prevalence of Salmonella contamination of animal feed varies widely between individual studies and is an ongoing challenge for the commercial feed industry. Control relies on the vigilant monitoring and control of Salmonella in each individual mill., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Historically, pre-clinical professional veterinary instruction has relied heavily on didactic methods. With the shift toward competency-based education in health professions teaching, instructors at The Ohio State University College of Veterinary Medicine are exploring alternative engagement strategies to focus on learner outcomes. In this article, we report on the integration of competency-based active learning techniques in a large-lecture setting, along with preliminary outcomes from the student perspective. A total of 110 students from Zoonotic Diseases, a two-credit core course offered in the second year of the 4-year professional curriculum, participated in the learning techniques and retrospective pre-/post-questionnaire. Results of the questionnaire indicated improvement in learners' perceived competency. For practical skills (e.g., donning and doffing of personal protective equipment), students also reported improved self-efficacy. Students enjoyed the interactive and self-directed learning techniques and described an improvement in their ability to evaluate their own understanding of relevant course concepts. The active learning techniques described herein may be used to supplement, and even transform, primarily lecture-based courses to better achieve professional competency and develop practice-ready veterinarians.

The changing epidemiologic role of wildlife as reservoirs of antimicrobial-resistant bacteria (ARB) is poorly understood. In this study, we characterize the phenotypic resistance of commensal Escherichia coli from fecal samples of 879 individual white-tailed (Odocoileus virginianus; WTD) over a ten-year period and analyze resistance patterns. Our results show commensal E. coli from WTD had significant linear increases in reduced susceptibility to 5 of 12 antimicrobials, including broad-spectrum cephalosporins and fluoroquinolones, from 2006 to 2016. In addition, the relative frequency distribution of minimal inhibitory concentrations of two additional antimicrobials shifted towards higher values from across the study period. The prevalence of multidrug-resistant commensal E. coli increased over the study period with a prevalence of 0%, 2.2%, and 3.7% in 2006, 2012, and 2016, respectively. WTD may be persistently and increasingly exposed to antibiotics or their residues, ARB, and/or antimicrobial resistance genes via contaminated environments like surface water receiving treated wastewater effluent., (© 2021. EcoHealth Alliance.)

Retail beef and pork, including processed products, can serve as vehicles for the zoonotic foodborne transmission of pathogens and antimicrobial resistant bacteria. However, processed and seasoned products like sausages, are not often included in research and surveillance programs. The objective of this study was to investigate retail ground beef and pork, including processed products, for the presence of common foodborne pathogens and antimicrobial resistant bacteria. We purchased 763 packages of fresh and fully cooked retail meat products during 29 visits to 17 grocery stores representing seven major grocery chains located in west and central Ohio. Each package of meat was evaluated for contamination with methicillin-resistant Staphylococcus aureus (MRSA), Salmonella spp., Enterobacteriaceae expressing extended-spectrum cephalosporin resistance, and carbapenemase-producing organisms (CPO). Only 3 of the 144 (2.1%) packages of fully cooked meat products contained any of these organisms, 1 with an extended-spectrum β-lactamase-producing (ESBL) Enterobacteriaceae and 2 with CPO. Among the 619 fresh meat products, we found that 85 (13.7%) packages were contaminated with MRSA, 19 (3.1%) with Salmonella, 136 (22.0%) with Enterobacteriaceae expressing an AmpC (bla CMY ) resistance genotype, 25 (4.0%) with Enterobacteriaceae expressing an ESBL (bla CTX-M ) resistance genotype, and 31 (5.0%) with CPO, primarily environmental organisms expressing intrinsic carbapenem resistance. However, one CPO, a Raoultella ornithinolytica, isolated from pork sausage co-harbored both bla KPC-2 and bla NDM-5 on IncN and IncX3 plasmids, respectively. Our findings suggest that fresh retail meat, including processed products can be important vehicles for the transmission of foodborne pathogens and antimicrobial resistant bacteria, including those with epidemic carbapenemase-producing genotypes.

Background: Leptospirosis is a zoonotic disease of concern and an investigation of recent spatio-temporal trends of leptospirosis in dogs in the United States is needed. Leptospira PCR testing has become increasingly used in veterinary clinical medicine and these data might provide information on recent trends of disease occurrence., Objectives: To identify and describe clusters of PCR-positive Leptospira test results in dogs in the United States., Animals: Leptospira real-time PCR test results from dogs (n = 40 118) in the United States from IDEXX Laboratories, Inc., between 2009 and 2016 were included in the analysis., Methods: In this retrospective study, spatio-temporal clusters for a real-time PCR-positive test were identified using the space-time permutation scan statistic and the centroid of the zip code reported for each test. A maximum spatial window of 20% of the population at risk, and a maximum temporal window of 6 months were used., Results: Seven statistically significant space-time clusters of Leptospira real-time PCR-positive test results were identified across the United States: 1 each located within the states of Arizona (2016), California (2014-2015), Florida (2010), South Carolina (2015), and 1 each located within the south-central region (2015), midwest region (2014), and northeast region (2011). Clusters ranged from 3 to 108 dogs and were identified during all years under study, except 2009, 2012, and 2013., Conclusions and Clinical Importance: The spatial and temporal components of leptospirosis in dogs in this study are similar to those in previous work. However, clusters were identified in new areas, demonstrating the complex epidemiology of this disease., (© 2021 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine.)

Objective: To estimate the prevalence of extended-spectrum cephalosporin-, carbapenem-, and fluoroquinolone-resistant bacteria of the family Enterobacteriaceae in the feces of hospitalized horses and on hospital surfaces., Sample: Fecal and environmental samples were collected from The Ohio State University Galbreath Equine Center (OSUGEC) and a private referral equine hospital in Kentucky (KYEH). Feces were sampled within 24 hours after hospital admission and after 48 hours and 3 to 7 days of hospitalization., Procedures: Fecal and environmental samples were enriched, and then selective media were inoculated to support growth of Enterobacteriaceae bacteria that expressed resistance phenotypes to extended-spectrum cephalosporins, carbapenems, and fluoroquinolones., Results: 358 fecal samples were obtained from 143 horses. More samples yielded growth of Enterobacteriaceae bacteria that expressed resistance phenotypes (AmpC β-lactamase, OR = 4.2; extended-spectrum beta-lactamase, OR = 3.2; and fluoroquinolone resistance, OR = 4.0) after 48 hours of hospitalization, versus within 24 hours of hospital admission. Horses hospitalized at KYEH were at greater odds of having fluoroquinolone-resistant bacteria (OR = 2.2). At OSUGEC, 82%, 64%, 0%, and 55% of 164 surfaces had Enterobacteriaceae bacteria with AmpC β-lactamase phenotype, extended-spectrum beta-lactamase phenotype, resistance to carbapenem, and resistance to fluoroquinolones, respectively; prevalences at KYEH were similarly distributed (52%, 32%, 1%, and 35% of 315 surfaces)., Conclusions and Clinical Relevance: Results indicated that antimicrobial-resistant Enterobacteriaceae may be isolated from the feces of hospitalized horses and from the hospital environment. Hospitalization may lead to increased fecal carriage of clinically important antimicrobial-resistance genes.

One objective of this study was to determine overall prevalence of Salmonella in ground pork from U.S. retail stores over three seasons including both case-ready and store-ground packages. Package types collected included: overwrap, chub, modified atmosphere packaging, and other (plastic or wax paper wrapped). Because package type represents different production systems and are subject to varied microbiological government regulation and testing methodologies, both USDA-FSIS and FDA Salmonella isolation protocols were performed. Another objective of the study was to determine serotypes and antimicrobial susceptibility profiles of the isolates obtained from the ground pork samples. Ground pork aliquots were subjected to real-time PCR. Recovered isolates were serotyped and minimum inhibitory concentration analysis to 15 antimicrobials was determined using microbroth dilution. Overall prevalence of Salmonella in ground pork from the 865 samples collected was 1.39%. Prevalence was not affected by package type ( p  = 0.29) nor grind location (case-ready vs. store-ground; p  = 0.17). Season affected Salmonella prevalence ( p  = 0.05) with most isolates found during fall, and there was a tendency for geographic region to affect prevalence ( p  = 0.07). The USDA Salmonella isolation method was more effective at recovering isolates ( p  = 0.01) compared with the FDA methodology and yielded a kappa statistic of 0.26 as a measure of agreement. The serotypes isolated included: Infantis, 4,5,12:i:-, Brandenburg, Typhimurium var 5-, Seftenberg, and Johannesburg with only two packages containing multiple serotypes. No isolates were resistant to antibiotics commonly used to treat human Salmonella infections including extended spectrum cephalosporins or fluoroquinolones. Although the recovery of Salmonella from retail ground pork samples was rare, Salmonella Typhimurium (and its monophasic variant 4,5,12:i:-), which are among the most common serovars recovered from human infections, were recovered. Therefore, more effective strategies to further reduce or eliminate these pathogens from retail pork products are warranted.

Widespread use of antimicrobials in human and veterinary medicine drives the emergence and dissemination of resistant bacteria in human, animal, and environmental reservoirs. The AVMA and FDA Center for Veterinary Medicine have both taken public positions emphasizing the importance of incorporating antimicrobial stewardship in veterinary clinical settings; however, a model for implementing a comprehensive antimicrobial stewardship program in veterinary practice is not readily available. In 2015, The Ohio State University College of Veterinary Medicine began developing a veterinary antimicrobial stewardship program modeled on existing programs in human health-care institutions and the 7 core elements of a successful hospital antimicrobial stewardship program, as defined by the CDC. The program includes comprehensive antimicrobial use guidelines, active environmental surveillance, and enhanced infection control procedures in The Ohio State University Veterinary Medical Center, along with routine monitoring and reporting of antimicrobial prescribing practices and antimicrobial susceptibility patterns of common pathogens isolated from patients and the hospital environment. Finally, programs have been developed to educate clinicians, staff, and students on antimicrobial resistance and appropriate antimicrobial prescribing practices. The antimicrobial stewardship program has been designed to help clinicians and students confidently make judicious antimicrobial use decisions and provide them with actionable steps that can help them act as strong stewards while providing the best care for their patients. This report describes our program and the process involved in developing it, with the intent that the program could serve as a potential model for other veterinary medical institutions.

Though carbapenems are not licensed for use in food animals in the U.S., carbapenem resistance among Enterobacteriaceae has been identified in farm animals and their environments. The objective of our study was to determine the extent to which older-generation β-lactam antibiotics approved for use in food animals in the U.S. might differentially select for resistance to antibiotics of critical importance to human health, such as carbapenems. Escherichia coli (E. coli) strains from humans, food animals, or the environment bearing a single β-lactamase gene (n = 20 each) for blaTEM-1, blaCMY-2, and blaCTX-M-* or else blaKPC/IMP/NDM (due to limited availability, often in combination with other bla genes), were identified, along with 20 E. coli strains lacking any known beta-lactamase genes. Baseline estimates of intrinsic bacterial fitness were derived from the population growth curves. Effects of ampicillin (32 μg/mL), ceftriaxone (4 μg/mL) and meropenem (4 μg/mL) on each strain and resistance-group also were assessed. Further, in vitro batch cultures were prepared by mixing equal concentrations of 10 representative E. coli strains (two from each resistance gene group), and each mixture was incubated at 37°C for 24 hours in non-antibiotic cation-adjusted Mueller-Hinton II (CAMH-2) broth, ampicillin + CAMH-2 broth (at 2, 4, 8, 16, and 32 μg/mL) and ceftiofur + CAMH-2 broth (at 0.5, 1, 2, 4, and 8μg/mL). Relative and absolute abundance of resistance-groups were estimated phenotypically. Line plots of the raw data were generated, and non-linear Gompertz models and multilevel mixed-effect linear regression models were fitted to the data. The observed strain growth rate distributions were significantly different across the groups. AmpC strains (i.e., blaCMY-2) had distinctly less robust (p < 0.05) growth in ceftriaxone (4 μg/mL) compared to extended-spectrum beta-lactamase (ESBL) producers harboring blaCTX-M-*variants. With increasing beta-lactam antibiotic concentrations, relative proportions of ESBLs and CREs were over-represented in the mixed bacterial communities; importantly, this was more pronounced with ceftiofur than with ampicillin. These results indicate that aminopenicillins and extended-spectrum cephalosporins would be expected to propagate carbapenemase-producing Enterobacteriaceae in food animals if and when Enterobacteriaceae from human health care settings enter the food animal environment., Competing Interests: The authors have declared that no competing interests exist.

Objective: To determine whether previous corrective upper airway surgery in brachycephalic dogs would decrease perianesthetic complications in subsequent anesthetic events., Animals: 45 client-owned dogs., Procedures: Brachycephalic dogs undergoing any combination of staphylectomy, nasal alaplasty, or laryngeal sacculectomy that were anesthetized at a later date for additional surgical procedures or imaging from August 2, 2007, to February 8, 2019, had their medical records reviewed during both anesthetic events for signalment, American Society of Anesthesiologists status, perianesthetic drug administration, anesthetic duration, presence and total time of positive-pressure ventilation, procedure invasiveness, and perianesthetic complications such as bradycardia, hypothermia, hypotension, cardiac arrhythmias, hypertension, vomiting or regurgitation, dysphoria, respiratory distress, hypoxemia, reintubation, and prolonged periods of recovery., Results: The odds of having complications during the postanesthetic period following subsequent anesthetic events were decreased by 79% in dogs having previous surgical intervention to correct clinical signs of brachycephalic airway syndrome. Intra-anesthetic bradycardia increased the odds of developing a postanesthetic complication by 4.56 times. Every 15-minute increase in anesthetic duration increased the odds of having a postanesthetic complication by 12% and having an intra-anesthetic complication by 11%., Conclusions and Clinical Relevance: Previous corrective upper airway surgery decreased odds of postanesthetic complications in brachycephalic dogs that underwent subsequent anesthetic events. Findings in this study indicated that corrective upper airway surgery for brachycephalic dogs may reduce postanesthetic complications following subsequent anesthetic events, which may reduce perianesthetic morbidity in patients undergoing multiple surgical or diagnostic imaging procedures.

Rapid transmission and spread of infectious pathogens are enhanced by the agricultural fair environment, where large numbers of livestock and people from numerous backgrounds congregate for several days. The transmission of influenza A virus and zoonotic enteric pathogens to fairgoers is a considerable risk and has occurred several times over the past decade. In an effort to mitigate zoonotic disease transmission in these settings, public health guidelines and recommendations including hand sanitation stations have been implemented. While hand hygiene recommendations to prevent the spread of zoonotic disease are well communicated, it is hypothesized that the adoption of these recommendations by agricultural fairs and fairgoers is low. To test this hypothesis, hand hygiene data collected from 658 agricultural fairs between 2012 and 2019 was analyzed to determine frequency and function of hand sanitation stations at the fairs, as well as utilization of educational signage. In addition, an observational study was performed to calculate the proportion of fairgoers who use hand sanitation stations at the fair. Lastly, samples were taken from working hand sanitation stations present at the exits of livestock barns and tested for the presence of influenza A virus and antimicrobial resistant coliform bacteria. Hand sanitation stations were present at most fairs (77.4 %) as recommended, but only 142 out of 2021 (7.0 %) visitors were observed using the stations. Health risk signage was displayed at more than half of fairs while the proper wash procedure was displayed at less than half. No influenza A virus was detected on any of the hand sanitation stations, however antimicrobial resistant coliform bacteria were recovered from 75.5 % of the sampled hand sanitation stations. Fairs should employ educational material along with functional hand sanitation stations in order to promote hand hygiene at fairs. Stations should be maintained and cleaned often to ensure effectiveness, as hand hygiene continues to be recommended to fairgoers when exiting animal barns to reduce zoonotic disease transmission., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Wastewater flows from metropolitan areas, especially those with healthcare inputs, can serve as transport reservoirs for the dissemination of clinically-relevant antimicrobial resistant bacteria (ARB) such as carbapenem- (CR) and colistin-resistant (CoR) strains. Pulsed electric field (PEF) is an emerging wastewater management tool for reducing bacterial loads without generating environmentally harmful byproducts, but it's ability to reduce ARB and their genetic determinants is not well reported. We collected 86, 10-L raw wastewater influent samples from a large metropolitan wastewater treatment plant in Columbus, Ohio and subjected them to low (34 kV cm -1 for 67 μsec) and high (36 kV cm -1 for 89 μsec) PEF treatment. We quantified the PEF effectiveness by measuring concentrations of total coliform bacteria, CR and CoR bacteria, and the epidemic carbapenemase gene, bla KPC , before and after PEF treatment. Utilizing marginal linear regression models with generalized estimating equations, we observed that low and high PEF treatment resulted in a 1.94 (95% CI 2.06-1.81; P < 0.001) and 2.32 (95% CI 2.46-2.18; P < 0.001) log reduction of total coliform bacteria concentrations, respectively. Low and high PEF treatment produced similar log reductions between CR E. coli (2.01 (95% CI 2.15-1.86; P < 0.001); 2.14 (95% CI: 5.30-4.61; P < 0.001)) and CR Enterobacteriaceae concentrations (1.55 (95% CI 1.70-1.41; P < 0.001); 1.86 (95% CI 2.05-1.68; P < 0.001)), and resulted in a 1.15 log (95% CI 1.38-0.93, P < 0.001) and 1.28 log (95% CI 1.54-1.03, P < 0.001) reduction of absolute bla KPC concentrations. Log CoR E. coli concentrations were reduced by 2.47 (95% CI 2.78-2.15; P < 0.001) and 2.52 (95% CI 2.91-2.15; P < 0.001) and CoR Enterobacteriaceae by 2.24 (95% CI 2.52-1.95; P < 0.001) and 2.50 (95% CI 2.89-2.11; P < 0.001) following low and high PEF application. PEF can be applied for wastewater management as an independent treatment method, particularly at critical control points, such as an on-site management of wastewater from hospitals or other healthcare facilities, or in series with other conventional methods to reduce total bacterial loads and concentrations of clinically-relevant ARB., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This research study was conducted to determine if bird depredation in feedlots is associated with the prevalence of ciprofloxacin-resistant Escherichia coli in cattle and to determine if removal of invasive bird species could be an effective management strategy to help reduce ciprofloxacin-resistant E. coli in cattle within the United States. European starlings (Sturnus vulgaris) were collected from feedlots within multiple geographic regions within the United States and European starlings within all regions tested positive for ciprofloxacin-resistant E. coli, but prevalence differed by region. Total number of birds on feedlots were positively associated with increased cattle fecal shedding of ciprofloxacin-resistant E. coli. Targeted control of invasive European starlings reduced bird numbers on feedlots by 70.4%, but decreasing populations of European starlings was not associated with corresponding reductions in bovine fecal prevalence of ciprofloxacin-resistant E. coli. These data provide evidence for the role of wild bird depredation in feedlots contributing to fecal shedding of ciprofloxacin-resistant E. coli, but a single month of European starling control in feedlots was not sufficient to impact the fecal carriage of this organism in cattle.

Background: Canine leptospirosis is a reemerging zoonotic disease concern in North America, and a better understanding of its epidemiology is needed. Wide-scale use and subsequent analyses of polymerase chain reaction (PCR) testing may provide additional insight into leptospirosis. This study aimed to describe temporal trends, to descriptively map, and to identify environmental, dog, and human-level factors associated with positive canine leptospirosis PCR test results in the United States., Results: Data obtained from IDEXX Laboratories, Inc. on 40,118 canine leptospirosis PCR tests run in the United States between 2009 and 2016 were evaluated. Climate and socioeconomic (e.g. urban influence, income) data were obtained from public databases. Choropleth maps were created to identify high test-positive proportion areas and a cross-sectional analysis was completed with generalized (univariable, followed by multivariable) mixed logistic regression models accounting for county within state to identify significant predictors for a positive test. Overall test-positive proportion was 5.4% across the United States, with the regional point estimate highest in the southwest (8.1%). In the final multivariable model, the odds of a positive test were greater for male dogs (Odds Ratio [OR] = 1.28) and dogs 0-4 years of age (ORs ranged from 0.35-0.71 for the other age groups). The odds of a positive test were greater for dogs living in areas with wet environmental conditions (OR = 1.24). Season and temperature, as well as the interaction between them, were significant predictors of a positive test. Dogs had a greater probability of testing positive during cool temperatures (< 4 °C) compared to the other temperature categories in the fall season., Conclusions: These findings based on PCR testing allow for an improved understanding of factors influencing a positive canine leptospirosis PCR test and will assist targeted education and prevention efforts.

Objective:  The aim of this study was to determine the accuracy and repeatability of the shoulder abduction test and to assess the effect of transection of the medial shoulder support structures in canine cadavers., Materials and Methods:  The shoulder abduction angle was measured by three separate observers, both with the shoulder extended and at a neutral angle. Shoulder abduction was then measured, using craniocaudal fluoroscopic images. Arthroscopy was performed in all shoulder joints, with the medial support structures transected in one shoulder of each dog. The three observers again measured shoulder abduction angles in all dogs. Shoulder abduction was measured again using fluoroscopy. Accuracy and repeatability of the abduction test were assessed using linear mixed models., Results:  All three observers had different measured abduction angles when compared with fluoroscopy ( p  < 0.01); however, the experienced surgeon had an error of only 2.9°. Inter-observer repeatability was poor, with all three observers having different abduction measurements ( p  < 0.001). Intra-observer repeatability, however, indicated no differences on repeated measurements ( p  = 0.26). Placing the shoulder at a neutral standing angle, and transection of support structures caused an average increase in abduction by 8.2° ( p  < 0.001) and 4.4° respectively., Conclusion:  Significant variation exists between observers performing this test, increased accuracy seen in the more experienced observer. Shoulder flexion angle can significantly affect measured abduction angles., Competing Interests: The authors of this study have no conflicts of interest to declare., (Georg Thieme Verlag KG Stuttgart · New York.)

Pharmacokinetics and pharmacodynamics of alfaxalone was performed in mallard ducks (Anas platyrhynchos) after single bolus injections of 10 mg/kg administered intramuscularly (IM; n = 10) or intravenously (IV; n = 10), in a randomized cross-over design with a washout period between doses. Mean (±SD) C max following IM injection was 1.6 (±0.8) µg/ml with T max at 15.0 (±10.5) min. Area under the curve (AUC) was 84.66 and 104.58 min*mg/ml following IV and IM administration, respectively. Volume of distribution (V D ) after IV dose was 3.0 L/kg. The mean plasma clearance after 10 mg/kg IV was 139.5 (±67.9) ml min -1  kg -1 . Elimination half-lives (mean [±SD]) were 15.0 and 16.1 (±3.0) min following IV and IM administration, respectively. Mean bioavailability at 10 mg/kg IM was 108.6%. None of the ducks achieved a sufficient anesthetic depth for invasive procedures, such as surgery, to be performed. Heart and respiratory rates measured after administration remained stable, but many ducks were hyperexcitable during recovery. Based on sedation levels and duration, alfaxalone administered at dosages of 10 mg/kg IV or IM in mallard ducks does not induce clinically acceptable anesthesia., (© 2019 John Wiley & Sons Ltd.)

Carbapenemase-producing bacteria (CPB) are rare, multidrug resistant organisms most commonly associated with hospitalized patients. Metropolitan wastewater treatment plants (WWTP) treat wastewater from large geographic areas which include hospitals and may serve as epidemiologic reservoirs for the maintenance or expansion of CPB that originate from hospitals and are ultimately discharged in treated effluent. However, little is known about the potential impact of these WWTP CPB on the local surface water and their risk to the public health. In addition, CPB that are present in surface water may ultimately disseminate to intensively-managed animal agriculture facilities where there is potential for amplification by extended-spectrum cephalosporins. To better understand the role of WWTPs in the dissemination of CPB in surface waters, we obtained samples of treated effluent, and both upstream and downstream nearby surface water from 50 WWTPs throughout the US. A total of 30 CPB with clinically-relevant genotypes were recovered from 15 WWTPs (30%) of which 13 (50%) serviced large metropolitan areas and 2 (8.3%) represented small rural populations (P < 0.05). Recovery of CPB was lowest among WWTPs that utilized ultraviolet radiation for primary disinfection (12%), and higher (P = 0.11) for WWTPs that used chlorination (42%) or that did not utilize disinfection (50%). We did not detect a difference in CPB recovery by sampling site, although fewer CPB were detected in upstream (8%) compared to effluent (20%) and downstream (18%) samples. Our results indicate that WWTP effluent and nearby surface waters in the US are routinely contaminated with CPB with clinically important genotypes including those producing Klebsiella pneumoniae carbapenemase (KPC) and New Delhi metallo-beta-lactamase (NDM). This is a concern for both public health and animal agriculture because introduction of CPB into intensively managed livestock populations could lead to their amplification and foodborne dissemination., Competing Interests: The authors have declared that no competing interests exist.

Globally, increasing acquired antimicrobial resistance among pathogenic bacteria presents an urgent challenge to human and animal health. As a result, significant efforts, such as the One Health Initiative, are underway to curtail and optimize the use of critically important antimicrobials for human medicine in all applications, including food animal production. This review discusses the rationale behind multiple and competing "critically important antimicrobial" lists and their contexts as created by international, regional, and national organizations; identifies discrepancies among these lists; and describes issues surrounding risk management recommendations that have been made by regulatory organizations on the use of antibiotics in food animal production. A more harmonized approach to defining criticality in its various contexts (e.g., for human versus animal health, enteric diseases versus other systemic infections, and direct versus indirect selection of resistance) is needed in order to identify shared contextual features, aid in their translation into risk management, and identify the best ways to maintain the health of food animals, all while keeping in mind the wider risks of antimicrobial resistance, environmental impacts, and animal welfare considerations., (© 2019 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals, Inc. on behalf of New York Academy of Sciences.)

Antimicrobial resistance (AMR) is a significant threat to both human and animal health. The spread of AMR bacteria and genes across systems can occur through a myriad of pathways, both related and unrelated to agriculture, including via wastewater, soils, manure applications, direct exchange between humans and animals, and food exposure. Tracing origins and drivers of AMR bacteria and genes is challenging due to the array of contexts and the complexity of interactions overlapping health practice, microbiology, genetics, applied science and engineering, as well as social and human factors. Critically assessing the diverse and sometimes contradictory AMR literature is a valuable step in identifying tractable mitigation options to stem AMR spread. In this article we review research on the nonfoodborne spread of AMR, with a focus on domesticated animals and the environment and possible exposures to humans. Attention is especially placed on delineating possible sources and causes of AMR bacterial phenotypes, including underpinning the genetics important to human and animal health., (© 2019 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals, Inc. on behalf of New York Academy of Sciences.)

Companion animals are likely relevant in the transmission of antimicrobial-resistant bacteria. Enterobacter xiangfangensis sequence type 171 (ST171), a clone that has been implicated in clusters of infections in humans, was isolated from two dogs with clinical disease in Ohio. The canine isolates contained IncHI2 plasmids encoding bla KPC-4 Whole-genome sequencing was used to put the canine isolates in phylogenetic context with available human ST171 sequences, as well as to characterize their bla KPC-4 plasmids., (Copyright © 2018 American Society for Microbiology.)

The dissemination of Enterobacteriaceae expressing resistance to clinically important antibiotics such as extended-spectrum cephalosporins (ESC), carbapenems, and fluoroquinolones is of critical concern to both human and veterinary medicine. In healthcare facilities, the movement of patients, personnel, and equipment provides an opportunity for Enterobacteriaceae carrying antibiotic resistance genes to disseminate in the hospital environment where they pose a threat to patients, staff, and hospital visitors. We collected environmental samples using electrostatic cloths to estimate the frequency of resistant Enterobacteriaceae contamination on human and veterinary hospital surfaces. Samples were enriched in nutrient broth modified with antibiotics to provide specific selection pressure to select for bacteria expressing AmpC β-lactamase (bla CMY ), extended-spectrum β-lactamase (ESBL, bla CTX-M ), carbapenemase, quinolone, and fluoroquinolone-resistant phenotypes. A total of 31 contact surfaces were sampled at each of five visits to two human hospitals. In addition, 34 surfaces were sampled at each of three visits to a veterinary hospital serving both farm animal and companion animal patients. Isolates expressing the bla CMY phenotype were recovered from 0.6%, 100%, and 18.2% of human hospitals, veterinary farm animal, and veterinary companion animal hospital surfaces, respectively. Isolates expressing the bla CTX-M phenotype were recovered from 0.6%, 55%, and 16.7% of human hospitals, farm animal, and companion animal veterinary hospital surfaces, respectively. Carbapenemase-producing Enterobacteriaceae (CPE) were detected from 1.3% of human hospital surfaces, but none were recovered from the veterinary hospital. Fluoroquinolone resistance was detected in 0.6%, 5.0%, and 37.9% of human hospitals, farm animal, and companion animal veterinary hospital surfaces, respectively. Our results indicate that ESC and fluoroquinolone-resistant Enterobacteriaceae can contaminate surfaces in both human and veterinary medical settings, with higher prevalence observed in veterinary hospitals, although the recovery of CPE from human hospital environments is concerning. Hospital medical trolleys or carts may serve as fomites for the dissemination of clinically relevant resistant bacteria.

Antimicrobial resistant bacteria in retail meat pose a health hazard to the public, as does contamination of these products with Salmonella. Our aim was to determine the prevalence of Salmonella as well as Escherichia coli expressing AmpC and extended-spectrum beta-lactamase (ESBL) resistance phenotypes contaminating broiler transport cages and fresh, retail ground chicken meat. Sterile gauze sponges were used to collect duplicate cage floor samples from transport trailers that deliver market-ready birds to a single organic poultry-processing facility. With the exception of the first visit (n = 25), 50 duplicate cage floor samples were collected using moistened sterile gauze sponges on each of nine weekly visits during May, June, and July 2013. Additionally, fresh, retail ground chicken meat was sampled at each weekly visit from an on-site retail store located at the same processing facility. A total of 425 cage swabs and 72 ground chicken aliquots from 24 retail packages were collected and screened for the presence of Salmonella as well as E. coli expressing resistance to extended-spectrum cephalosporins using selective culture. We recovered Salmonella from 26.1% of cage swab samples and 2.8% of retail meat samples. E. coli expressing AmpC and ESBL resistance phenotypes were recovered from 84.9% and 22.6% of cage swabs and 77.8% and 11.1% of fresh, retail ground meat samples, respectively. Our results suggest that transport cages could potentially act as a source of broiler exposure to both Salmonella and enteric bacteria resistant to important antimicrobial drugs as they are transported for entry into the food supply as fresh, retail meat products.

OBJECTIVE To determine whether brachycephalic dogs were at greater risk of anesthesia-related complications than nonbrachycephalic dogs and identify other risk factors for such complications. DESIGN Retrospective cohort study. ANIMALS 223 client-owned brachycephalic dogs undergoing general anesthesia for routine surgery or diagnostic imaging during 2012 and 223 nonbrachycephalic client-owned dogs matched by surgical procedure and other characteristics. PROCEDURES Data were obtained from the medical records regarding dog signalment, clinical signs, anesthetic variables, surgery characteristics, and complications noted during or following anesthesia (prior to discharge from the hospital). Risk of complications was compared between brachycephalic and nonbrachycephalic dogs, controlling for other factors. RESULTS Perianesthetic (intra-anesthetic and postanesthetic) complications were recorded for 49.1% (n = 219) of all 446 dogs (49.8% [111/223] of brachycephalic and 48.4% [108/223] of nonbrachycephalic dogs), and postanesthetic complications were recorded for 8.7% (39/446; 13.9% [31/223] of brachycephalic and 3.6% [8/223] of nonbrachycephalic dogs). Factors associated with a higher perianesthetic complication rate included brachycephalic status and longer (vs shorter) duration of anesthesia; the risk of perianesthetic complications decreased with increasing body weight and with orthopedic or radiologic procedures (vs soft tissue procedures). Factors associated with a higher postanesthetic complication rate included brachycephalic status, increasing American Society of Anesthesiologists status, use of ketamine plus a benzodiazepine (vs propofol with or without lidocaine) for anesthetic induction, and invasive (vs noninvasive) procedures. CONCLUSIONS AND CLINICAL RELEVANCE Controlling for other factors, brachycephalic dogs undergoing routine surgery or imaging were at higher risk of peri- and postanesthetic complications than nonbrachycephalic dogs. Careful monitoring is recommended for brachycephalic dogs in the perianesthetic period.

Antimicrobial-resistant bacteria represent an important concern impacting both veterinary medicine and public health. The rising prevalence of extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase, carbapenemase (CRE) and fluoroquinolone-resistant Enterobacteriaceae continually decreases the efficiency of clinically important antibiotics. Moreover, the potential for zoonotic transmission of antibiotic-resistant enteric bacteria increases the risk to public health. Our objective was to estimate the prevalence of specific antibiotic-resistant bacteria on human contact surfaces in various animal environments. Environmental surface samples were collected from companion animal shelters, private equine facilities, dairy farms, livestock auction markets and livestock areas of county fairs using electrostatic cloths. Samples were screened for Enterobacteriaceae expressing AmpC, ESBL, CRE or fluoroquinolone resistance using selective media. Livestock auction markets and county fairs had higher levels of bacteria expressing both cephalosporin and fluoroquinolone resistance than did equine, dairy, and companion animal environments. Equine facilities harboured more bacteria expressing cephalosporin resistance than companion animal shelters, but less fluoroquinolone resistance. The regular use of extended-spectrum cephalosporins in livestock populations could account for the increased levels of cephalosporin resistance in livestock environments compared to companion animal and equine facilities. Human surfaces, as well as shared human and animal surfaces, were contaminated with resistant bacteria regardless of species environment. Detecting these bacteria on common human contact surfaces suggests that the environment can serve as a reservoir for the zoonotic transmission of antibiotic-resistant bacteria and resistance genes. Identifying interventions to lower the prevalence of antibiotic-resistant bacteria in animal environments will protect both animal and public health., (© 2018 Blackwell Verlag GmbH.)

Background: The provincial wildlife management agency, British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development, performed a translocation to control the urban mule deer ( Odocoileus hemionus ; uMD) overpopulation and supplement the declining non-urban mule deer (nuMD) population in the Kootenay region, British Columbia, Canada. The objectives of this cross-sectional study were to evaluate the health of the urban and nuMD populations by comparing pathogen exposure, body condition scores (BCS) and pregnancy rates, to characterize the health risks associated with the translocation and to investigate the role of infectious diseases in the decline of the nuMD deer population., Methods: Two hundred free-ranging mule deer were captured in urban and non-urban environments in the Kootenay region from 2014 to 2017. BCS and morphometric examinations were performed for each deer. Blood samples collected from each deer were tested for exposure to selected pathogens and pregnancy status., Results: Body condition scores averaged 3.4 on a five-point scale, was greater in nuMD, and significantly differed between years. Antibodies were detected for adenovirus hemorrhagic disease virus (38.4% (uMD 43.7%, nuMD 33.3%)), bluetongue virus (0.6% (uMD 1.2%, nuMD 0%)), bovine respiratory syncytial virus (8.4% (uMD 4.6%, nuMD 12.1%)), bovine viral diarrhea virus (1.1% (uMD 0%, nuMD 2.2%)), bovine parainfluenza-3 virus (27.0% (uMD 27.6%, nuMD 26.4%)), Neospora caninum (22.1% (uMD 24.4%, nuMD 19.7%)) and Toxoplasma gondii (8.2% (uMD 12.3%, nuMD 3.9%)). No antibodies against epizootic hemorrhagic disease virus were detected. Pregnancy rates did not differ between the two deer populations (90.7% (uMD 90.6%, nuMD 90.9%)). Exposure to N. caninum was associated with a reduced probability of being pregnant. uMD were more likely to be exposed to T. gondii than nuMD., Discussion: Comparison of BCS, pregnancy rates and pathogen exposure of uMD and nuMD showed that the health of the two populations did not significantly differ, suggesting uMD translocations do not pose a severe risk of pathogen transmission between mule deer populations and that these selected pathogens do not factor in the decline of the nuMD population. However, inclusion of additional health indicators and creation of a robust predictive disease model are warranted to further characterize the health of mule deer and the health risks associated with uMD translocations. These results should be considered as part of a formal risk assessment for future uMD translocations in southeastern British Columbia., Competing Interests: The authors declare that they have no competing interests.

Carbapenemase-producing Enterobacteriaceae (CPE) threaten both agriculture and public health. While carbapenems are restricted in food-producing animals, other β-lactams, such as ceftiofur, are frequently applied in livestock. While the relationship is not fully elucidated, ceftiofur use may provide selective pressure that promotes carbapenem resistance. Recently reported in U.S. livestock, plasmid-mediated CPE are also present in livestock in Europe and Asia. We previously reported the rare carbapenemase gene, bla IMP-64 , in the environment of a large farrow-to-finish swine operation. To better understand CPE in this swine production system, in 2016 we followed a cohort of 350+ pigs over 5 months from late sow gestation to the final finishing phase. We screened both environmental and fecal samples for CPE using our selective enrichment protocol, with resulting phenotypic CPE isolates further characterized. Of 55 environmental and 109 sow fecal samples collected from a farrowing barn on our initial visit, 35 (64%) environmental and 15 (14%) sow fecal samples yielded isolates of multiple Enterobacteriaceae species carrying the metallo-β-lactamase gene bla IMP-64 on an IncQ plasmid. The frequency of IMP-64-positive environmental (n = 32), sow fecal (n = 30), and piglet fecal swab (n = 120) samples was highest for all groups when the market pig cohort was between 1 and 10 days, with observed prevalence of 97%, 28%, and 18%, respectively. After weaning, bla IMP-64 was detected in a single environmental sample from a nursery pen, with no CPE recovered in the finishing phase. Used in U.S. swine production to treat and control disease, ceftiofur is administered to piglets on this farm at birth, with males receiving a second dose at castration (≈day 7). Once introduced into animal agriculture, the common use of ceftiofur may provide the selection pressure required for CPE dissemination throughout large, intensively managed food animal populations housed in animal-dense environments.

Dogs are often present on livestock farms, where they serve important management and companion roles, yet may be involved in zoonotic pathogen transmission. Numerous factors can potentially alter the risk of exposure to zoonotic pathogens, such as the dog's access to livestock, close dog-human contact and an increasing immunocompromised human population. The objective of this study was to quantify and qualify dog ownership among livestock owners, their dog husbandry and biosecurity practices, the dogs' access to livestock and potential risks for zoonotic pathogen transmission. A questionnaire was developed and mailed to 2,000 presumed Ohio livestock owners. Data were collected on demographics, dog husbandry practices, attitudes surrounding zoonotic diseases and attachment to and preventive veterinary care for the dogs. There were 446 responders who met the study inclusion criteria as an Ohio livestock farm owner, with 297 (67%) also owning dogs. Approximately 52% of dog-owning households included at least one individual at higher disease risk (i.e., <5 years, ≥65 years, diagnosed with an immunocompromising condition). Most respondents had little/no concern for disease transmission from livestock to dogs (90%), from dogs to livestock (87%) and from dogs to people (94%). Dogs were allowed access to livestock by 70% of respondents and nearly all (96%; 198) indicated at least one higher risk dog-livestock management practice. In addition, many reported never leashing or fencing their dog (61%) and rarely to never picking up dog faeces (76%). Households with higher risk members reported similar husbandry, biosecurity and concern levels as households without those members (all p > .05). Numerous opportunities for zoonotic pathogen transmission and low level of zoonotic disease concern suggest a need for improved education and outreach for the livestock dog-owning community, particularly for higher risk households., (© 2017 Blackwell Verlag GmbH.)

Background: The diagnosis of equine protozoal myeloencephalitis (EPM) relies heavily on the clinical examination. The accurate identification of neurologic signs during a clinical examination is critical to the interpretation of laboratory results., Objective: To investigate the level of agreement between board-certified veterinary internists when performing neurologic examinations in horses., Animals: Ninety-seven horses admitted to the Veterinary Teaching Hospital at The Ohio State University from December 1997 to June 1998., Methods: A prospective epidemiologic research design was used. Horses enrolled in the study were examined by the internist responsible for care of the horse, and later by an internist who was not aware of the presenting complaint or other patient history. Data were analyzed by descriptive statistics, and kappa (K) statistics were calculated to assess interobserver agreement., Results: Ninety-seven horses were enrolled in the study. Overall, examiners, also referred to as observers, agreed that 60/97 (61.9%) were clinically abnormal, 21/97 (21.6%) were clinically normal, and the status of 16/97 (16.5%) of horses was contested. There was complete agreement among the examiners with regard to cranial nerve signs and involuntary movements. Disagreement involving severity of clinical signs occurred in 31 horses, and 25 of those horses (80.6%) were considered either normal or mildly affected by the primary observer. When examining the results of all paired clinical examinations for 11 different categories, there was wide variability in the results. When examiners rated the presence or absence of any neurologic abnormalities, lameness, or ataxia, the agreement among observers was either good or excellent for 80% of horses. When assessing truncal sway, the agreement among observers was good or excellent for 60% of the horses. When examining the horses for asymmetry of deficits, agreement was either good or excellent for 40% of the horses. Agreement among observers was excellent or good for only 20% of the horses when assessing muscle atrophy, spasticity (hypermetria), and overall assessment of the severity of neurologic abnormalities., Conclusions and Clinical Importance: This study underscores the subjectivity of the neurologic examination and demonstrates a reasonable level of agreement that may be achieved when different clinicians examine the same horse., (Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

In order to estimate the prevalence of AmpC- and ESBL β-lactamase-producing Enterobacteriaceae in the faecal flora of a healthy domestic canine population, faecal samples were obtained from healthy dogs receiving routine parasitology screening at the Ohio State University Veterinary Medical Center, between January 2013 and April 2013. Samples were screened for the presence of AmpC and ESBL β-lactamase phenotypes, and the clinically important genotypes, bla CMY and bla CTX -M , were confirmed via conventional PCR. Minimum inhibitory concentrations were determined for isolates and plasmids were characterized. Two hundred and twelve canine faecal samples were screened, of which 30 harboured isolates carrying the AmpC bla CMY , representing 14.2% of the population (95% CI: 9.4-18.9%). Nine samples harboured isolates that carried the ESBL bla CTX -M , representing 4.2% of the population (95% CI: 1.5-7.0%). Isolates containing bla CMY harboured multiple plasmid replicon types, while isolates containing bla CTX -M harboured few plasmid replicon types. Our results suggest that domestic dogs may serve as a reservoir for extended-spectrum cephalosporin resistance genes for other domestic animal populations as well as for their human companions. This represents a potential veterinary and public health risk that warrants further investigation and continued surveillance to ascertain the nature and extent of the risk. The high level of diversity of plasmid content among isolates harbouring bla CMY suggests broader dissemination relative to bla CTX -M isolates., (© 2017 Blackwell Verlag GmbH.)

In the US, nontyphoidal Salmonellae are a common foodborne zoonotic pathogen causing gastroenteritis. Invasive Salmonella infections caused by extended-spectrum cephalosporin resistant (ESCR) phenotypes are more likely to result in treatment failure and adverse health outcomes, especially in severe pediatric Salmonella infections where the extended-spectrum β-lactams are the therapy of choice. To examine the genetic and epidemiologic characteristics of ESCR Salmonellae which may enter the food chain, we characterized 44 ceftiofur-resistant Salmonella isolates from the National Animal Health Monitoring System (NAHMS) 2011 beef cattle feedlot health and management study. As part of the NAHMS Feedlot 2011 study, 5050 individual fecal samples from 68 large (1000+ head capacity) feedlots were cultured for Salmonella spp. The resulting 460 positive samples yielded 571 Salmonella isolates with 44 (8%) expressing an AmpC β-lactamase phenotype. These phenotypic bla CMY-2 Salmonella isolates represented 8 serotypes, most commonly S. Newport (n=14, 32%), S. Typhimurium (n=13, 30%), and S. Reading (n=5, 11%), followed by S. Dublin, S. Infantis, S. Montevideo, S. Rough O:i;v:1;7, and S. Uganda. Carriage of the bla CMY-2 gene was confirmed for all isolates expressing an AmpC β-lactamase phenotype by PCR. Additionally, all 44 isolates were shown to carry the bla CMY-2 gene on a large IncA/C plasmid, a gene/plasmid combination which has been previously reported in multiple species. Other plasmids, including IncN, FIC, and FIIA, were also detected in some isolates. Cattle fed chlortetracycline were less likely to be positive for a bla CMY-2 Salmonella isolate in their enteric flora compared to those not receiving chlortetracycline during the feeding period. Carriage of bla CMY-2 was more prevalent in Salmonella isolates originating from lighter weight cattle, cattle fed tylosin and dairy breeds. Our characterization of the NAHMS Feedlot 2011 study Salmonella isolates with ESCR phenotype shows that while other cephalosporin resistance mechanisms have been reported in US cattle, specific serotypes harboring bla CMY-2 on IncA/C plasmids may be the dominant resistance genotype., (Copyright © 2017 Elsevier B.V. All rights reserved.)

We tested 772 cloacal swabs from wild ducks to estimate the prevalence of enteric bacteria resistant to extended-spectrum cephalosporins (ESC). We found a low prevalence of the important ESC resistance genotypes, bla CMY (5.7%) and bla CTX-M (0.3%). This suggests a minor role for wild ducks in the movement of resistant bacteria in the environment.