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Aims: Salmonella enterica is a leading cause of acute enteritis in people, and dairy cattle are an important reservoir of this pathogen. The objective of this study was to analyse serotype and anti‐microbial resistance trends of Salmonella isolated from dairy cattle in the United States between 2007 and 2021. Methods and Results: We collected data for bovine Salmonella isolates obtained from samples submitted to Cornell University's Animal Health Diagnostic Center (AHDC). We analysed 5114 isolates for serotype trends, and a subset of 2521 isolates tested for anti‐microbial susceptibility were analysed for resistance trends. The most frequently identified serotypes were Salmonella Cerro, Dublin, Typhimurium, Montevideo, 4,[5],12:i:‐, and Newport. Among these serotypes, a Cochran–Armitage trend test determined there was a significant increase in the proportion of isolates serotyped as Salmonella Dublin (p < 0.0001) and Montevideo (p < 0.0001) over time. There was a significant decrease in the proportion of isolates serotyped as Salmonella Cerro (p < 0.0001), Typhimurium (p < 0.0001), and Newport (p < 0.0001). For the anti‐microbial resistance (AMR) analysis, we found an overall increase in the proportion of multi‐drug‐resistant isolates over time (p = 0.009). There was a significant increase in the proportion of isolates resistant to ampicillin (p = 0.007), florfenicol (p = 0.0002), and ceftiofur (p < 0.0001) and a marginal increase in resistance to enrofloxacin (p = 0.05). There was a significant decrease in the proportion of isolates resistant to spectinomycin (p = 0.0002), trimethoprim/sulphamethoxazole (p = 0.01), sulphadimethoxine (p = 0.003), neomycin (p < 0.0001), and gentamicin (p = 0.0002). Conclusions: Our results provide evidence of an increase in resistance to key anti‐microbial agents, although the observed trends were driven by the sharp increase in the proportion of Salmonella Dublin isolates over time. [ABSTRACT FROM AUTHOR]

Global emergence of ciprofloxacin‐resistant ST198 Salmonella Kentucky poses an important public health threat. While conducting Salmonella surveillance among wildlife patients admitted to our veterinary medical teaching hospital in central New York, we isolated multidrug‐resistant (MDR) ST198 Salmonella Kentucky from an American black bear (Ursus americanus) in September 2020. The isolate was phenotypically resistant to numerous antimicrobial agents, including ceftriaxone and ciprofloxacin, and several antimicrobial resistance genes and mutational resistance determinants were detected. Between April and July 2021, the same strain of MDR ST198 Salmonella Kentucky was also isolated from seven other wildlife patients and multiple hospital environmental locations, suggesting nosocomial transmission. Ciprofloxacin resistance is conferred by triple point mutations in the quinolone resistance‐determining regions (QRDRs), a genotypic profile indicative of Clade ST198.2. To our knowledge, this is the first report of this ciprofloxacin‐resistant clade being identified in animals or animal products in the United States. Timely resolution of the outbreak was achieved following efforts to further enhance environmental disinfection protocols and biosecurity measures at the hospital, with no known cases or positive environmental samples after July 2021. [ABSTRACT FROM AUTHOR]

Mycobacterium bovis is the etiologic agent of bovine tuberculosis (BTB), a serious infectious disease in both humans and animals. BTB is a zoonotic disease primarily affecting cattle and occasionally humans infected through close contact with infected hosts or the consumption of unpasteurized dairy products. Zoonotic tuberculosis is strongly associated with poverty and poor hygiene, and low- and middle-income countries bear the brunt of the disease. BTB has been increasingly recognized as a growing public health threat in developing countries. However, the lack of effective surveillance programs in many of these countries poses a barrier to accurately determining the true burden of this disease. Additionally, the control of BTB is threatened by the emergence of drug-resistant strains that affect the effectiveness of current treatment regimens. Here, we analyzed current trends in the epidemiology of the disease as well as the antimicrobial susceptibility patterns of M. bovis in the Middle East and North Africa (MENA) region, a region that includes several developing countries. Following PRISMA guidelines, a total of 90 studies conducted in the MENA region were selected. Our findings revealed that the prevalence of BTB among humans and cattle varied significantly according to the population size and country in the MENA region. Most of the available studies were based on culture and/or PCR strategies and were published without including data on antimicrobial resistance and molecular typing. Our findings highlighted the paramount need for the use of appropriate diagnostic tools and the implementation of sustainable control measures, especially at the human/animal interface, in the MENA region. [ABSTRACT FROM AUTHOR]

Background: Listeria monocytogenes (Lm) present in farming soil and food‐processing facilities threatens food safety, but little is known about the carriage of Lm by wildlife. Objectives: We estimated the prevalence of faecal Lm shedding among wildlife admitted to a veterinary medical teaching hospital in central New York and characterized a subset of the Lm isolates. Methods: Wildlife samples were collected between May 2018 and December 2019. We characterized the Lm isolates by assessing the growth at three temperatures approximating the body temperatures of reptiles (25°C), mammals (37°C), and birds (42°C) and identifying genotypic characteristics related to transmission and virulence. Results: The apparent prevalence of faecal Lm shedding was 5.6% [18/324; 95% confidence interval (CI), 3.3%–8.6%]. Among 13 isolates that represented two lineages and 11 clonal complexes, three and five isolates were grouped into the same SNP clusters with human clinical isolates and environmental isolates, respectively. However, specific SNP difference data showed that Lm from wildlife was generally not closely related (>22 SNP differences) to Lm from human clinical sources and the food‐processing environment. While the stress response locus SSI‐2 was absent, SSI‐1 was found in four isolates. Virulence genes prfA, plcA, hly, mpl, actA, plcB, inlA, inlB, inlC, inlE, inlH, inlJ, and inlK were present, without any premature stop codons, in all isolates. Virulence loci Listeria pathogenicity island 3 (LIPI‐3) and LIPI‐4, which have been linked to hypervirulence, and inlG were found in four, three, and seven isolates, respectively. Conclusions: Wildlife represents a potential reservoir for genetically diverse and putatively hypervirulent Lm strains. No statistically significant association between growth parameters and hosts was observed. However, compared to lineage I isolates, lineage II isolates showed significantly (p < 0.05) faster growth at 25°C and significantly slower growth at 42°C, suggesting that wildlife Lm isolates that belong to lineages I and II differ in their ability to grow at 25°C and 42°C. [ABSTRACT FROM AUTHOR]

The role of wildlife as a source of zoonotic Salmonella transmission is poorly understood, as are the clinical implications of this pathogen among wildlife species. Wildlife hospitals represent an important location to conduct Salmonella surveillance, given the wide variety of species admitted for medical and surgical care. Our objectives were to estimate the prevalence of fecal Salmonella shedding among wildlife admitted to a veterinary medical teaching hospital, to identify risk factors for infection, and to fully characterize the isolates. Voided fecal samples (birds and mammals) and cloacal swab samples (reptiles and amphibians) were collected between May 2018 and March 2020. Standard bacteriologic culture methods were used to detect Salmonella, and isolates were characterized via serotyping, antimicrobial susceptibility testing, and whole-genome sequencing. Samples were collected from 348 wildlife patients representing 74 wildlife species, and the apparent prevalence of fecal Salmonella shedding was 1.4% (5/348; 95% confidence interval, 0.5–3.3%). Four serotypes were identified, and isolates were phenotypically susceptible to all antimicrobial agents tested. Two isolates were closely related to human clinical isolates, demonstrating the overlap between wildlife and human pathogens. Fecal Salmonella shedding among hospitalized wildlife appears to be uncommon, and the risk of either nosocomial or zoonotic Salmonella transmission is presumably low. Nevertheless, the occurrence of Salmonella in wildlife, particularly among common species found in a wide array of habitats, poses a potential threat to public health and may result in transmission to more-vulnerable wildlife populations. [ABSTRACT FROM AUTHOR]

Dogs are a potential source of zoonotic Salmonella transmission. We had previously estimated the prevalence of Salmonella shedding among shelter dogs throughout Texas using a repeated cross‐sectional study design. Our current objectives were to fully characterize the Salmonella isolates and to assess their relatedness, using whole‐genome sequencing. Antimicrobial resistance (AMR) genes were detected in 4/27 (15%) of the isolates. The fosfomycin resistance gene fosA7 was identified in two isolates; to our knowledge, there are no published reports of this gene in canine Salmonella isolates. The biocide resistance gene qacEdelta1, conferring resistance to quaternary ammonium compounds, was detected in an isolate that had four additional AMR genes. The most frequently identified serotypes were Newport (6/27, 22%) and Javiana (4/27, 15%), both of which were widespread among animal shelters. For these serotypes, there was evidence of both transmission of Salmonella within the shelter environment and separate introductions of Salmonella into a shelter. Several canine Salmonella isolates were closely related to human clinical isolates (four canine isolates within 10 SNPs and six more within 20 SNPs), suggesting a shared pathogen population. Educational outreach programmes targeting animal shelter workers would be useful for optimizing knowledge of Salmonella and other canine‐associated zoonotic pathogens. [ABSTRACT FROM AUTHOR]

Salmonella Dublin is an important cause of salmonellosis among dairy cattle and poses a considerable threat to public health. This serotype is increasingly being identified among bovine Salmonella isolates from clinical samples in the north‐eastern United States, and these isolates are generally multidrug resistant. Our objective was to estimate the herd‐level prevalence of Salmonella Dublin among dairy cattle herds throughout New York. Bulk tank milk samples from nearly all commercial dairy herds in New York were collected from milk quality testing laboratories during the first half of 2013. Antibody testing of bulk tank milk was performed using a Salmonella Dublin ELISA kit. Samples representing 4,896 commercial dairies were collected, and antibodies against Salmonella Dublin were detected in 46 herds (0.9%; 95% CI, 0.7%–1.3%). Given the herd‐level sensitivity of ELISA testing for Salmonella Dublin in bulk tank milk at a single timepoint, this approach presumably underestimated the true prevalence. Some Salmonella Dublin‐positive herds had both positive and negative bulk tanks at the same sampling time, indicating that herds with multiple tanks should test all of them when using this ELISA. Further research is needed to better understand the epidemiologic features of Salmonella Dublin in the north‐eastern United States, including risk factors for introduction into dairy herds and principal transmission pathways. [ABSTRACT FROM AUTHOR]

The population size and geographic range of feral pigs in the United States are rapidly expanding. Nevertheless, the role of this invasive species in the ecology and transmission of zoonotic enteric pathogens is poorly understood. Our objectives were to describe the prevalence and diversity of Cryptosporidium and Giardia shedding among feral pigs throughout Texas and to identify risk factors for infection. Fecal samples were collected from feral pigs in Texas from February 2014 through May 2015. Cryptosporidium oocysts and Giardia cysts were detected using a direct immunofluorescence assay, and genotyping of positive samples was performed. The prevalence of Cryptosporidium shedding was 1.6% (6/370), and C. scrofarum and C. suis were identified. The prevalence of Giardia shedding was 4.3% (16/370), and assemblages A and E were identified. Cryptosporidium shedding was significantly more common among juvenile and subadult pigs than among adult pigs, but age group was not associated with Giardia shedding status. Feral pigs may serve as a source of Cryptosporidium and Giardia transmission to humans and livestock. [ABSTRACT FROM AUTHOR]