Prevalence and Molecular Characterization of Extended-Spectrum ß-Lactamase Producing Enterobacterales in Healthy Community Dogs in Israel.

BACKGROUND: antimicrobial resistance is a global problem in human and veterinary medicine. We aimed to investigate the extended spectrum ß-lactamase-producing Enterobacterales (ESBL-PE) gut colonization in healthy community dogs in Israel. METHODS: Rectal swabs were sampled from 145 healthy dogs, enriched, plated on selective plates, sub-cultured to obtain pure cultures, and ESBL production was confirmed. Bacterial species and antibiotic susceptibility profiles were identified. WGS was performed on all of the ESBL-PE isolates and their resistomes were identified in silico. Owners' questionnaires were collected for risk factor analysis. RESULTS: ESBL-PE gut colonization rate was 6.2% (n = 9/145, 95% CI 2.9-11.5). Overall, ten isolates were detected (one dog had two isolates); the main species was Escherichia coli (eight isolates), belonging to diverse phylogenetic groups-B1, A and C. Two isolates were identified as Citrobacter braakii, and C. portucalensis. A phylogenetic analysis indicated that all of the isolates were genetically unrelated and sporadic. The isolates possessed diverse ESBL genes and antibiotic-resistance gene content, suggesting independent ESBL spread. In a multivariable risk factor analysis, coprophagia was identified as a risk factor for ESBL-PE gut colonization (p = 0.048, aOR = 4.408, 95% CI 1.014-19.169). CONCLUSIONS: healthy community dogs may be colonized with ESBL-PE MDR strains, some of which were previously reported in humans, that carry wide and diverse resistomes and may serve as a possible source for AMR.

Third Generation Cephalosporin Resistant Enterobacterales Infections in Hospitalized Horses and Donkeys: A Case-Case-Control Analysis.

In human medicine, infections caused by third-generation cephalosporin-resistant Enterobacterales (3GCRE) are associated with detrimental outcomes. In veterinary medicine, controlled epidemiological analyses are lacking. A matched case-case-control investigation (1:1:1 ratio) was conducted in a large veterinary hospital (2017-2019). In total, 29 infected horses and donkeys were matched to 29 animals with third-generation cephalosporin-susceptible Enterobacterales (3GCSE) infections, and 29 uninfected controls (overall n = 87). Despite multiple significant associations per bivariable analyses, the only independent predictor for 3GCRE infection was recent exposure to antibiotics (adjusted odds ratio (aOR) = 104, p < 0.001), but this was also an independent predictor for 3GCSE infection (aOR = 22, p < 0.001), though the correlation with 3GCRE was significantly stronger (aOR = 9.3, p = 0.04). In separated multivariable outcome models, 3GCRE infections were independently associated with reduced clinical cure rates (aOR = 6.84, p = 0.003) and with 90 days mortality (aOR = 3.6, p = 0.003). Klebsiella spp. were the most common 3GCRE (36%), and blaCTX-M-1 was the major ß-lactamase (79%). Polyclonality and multiple sequence types were evident among all Enterobacterales (e.g., Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae). The study substantiates the significance of 3GCRE infections in equine medicine, and their independent detrimental impact on cure rates and mortality. Multiple Enterobacterales genera, subtypes, clones and mechanisms of resistance are prevalent among horses and donkeys with 3GCRE infections.

Extended-Spectrum ß-Lactamase-Producing Enterobacterales Shedding by Dogs and Cats Hospitalized in an Emergency and Critical Care Department of a Veterinary Teaching Hospital.

Extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-PE) gut shedding in human medicine is considered as a major reservoir for ESBL-associated infections in high risk patients. In veterinary medicine, data regarding ESBL-PE gut shedding on admission to emergency and critical care department is scarce. We aimed to determine ESBL-PE shedding rates by dogs and cats in this setting and to determine the risk factors for shedding, at two separate periods, three-years apart. Rectal swabs were collected from animals, on admission and 72 h post admission, enriched and plated on Chromagar ESBL plates, followed by bacterial identification. ESBL phenotype was confirmed and antibiotic susceptibility profiles were determined (Vitek 2). Medical records were reviewed for risk factor analysis (SPSS). Overall, 248 animals were sampled, including 108 animals on period I (2015-2016) and 140 animals on period II (2019). In both periods combined, 21.4% of animals shed ESBL-PE on admission, and shedding rates increased significantly during hospitalization (53.7%, p-value < 0.001). The main ESBL-PE species were Escherichia coli and Klebsiella pneumoniae, accounting for more than 85% of the isolates. In a multivariable analysis, previous hospitalization was a risk factor for ESBL-PE gut shedding (p-value = 0.01, Odds ratio = 3.05, 95% Confidence interval 1.28-7.27). Our findings demonstrate significant ESBL-PE gut shedding among small animals in the emergency and critical care department, posing the necessity to design and implement control measures to prevent transmission and optimize antibiotic therapy in this setting.

Evaluation of single and double-locus real-time PCR assays for methicillin-resistant Staphylococcus aureus (MRSA) surveillance.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a human pathogen, representing an infection control challenge. Conventional MRSA screening takes up to three days, therefore development of rapid detection is essential. Real time-PCR (rt-PCR) is the fastest method fulfilling this task. All currently published or commercially available rt-PCR MRSA assays relay on single or double-locus detection. Double-locus assays are based on simultaneous detection of mecA gene and a S. aureus-specific gene. Such assays cannot be applied on clinical samples, which often contain both coagulase-negative staphylococci (CoNS) and S. aureus, either of which can carry mecA. Single-locus assays are based on detection of the staphylococcal cassette chromosome mec (SCCmec) element and the S. aureus-specific orfX gene, assuming that it is equivalent to mecA detection. FINDINGS: Parallel evaluation of several published single and double-locus rt-PCR MRSA assays of 150 pure culture strains, followed by analysis of 460 swab-derived clinical samples which included standard identification, susceptibility testing, followed by PCR detection of staphylococcal suspected isolates and in-PCR mixed bacterial populations analysis indicated the following findings.Pure cultures analysis indicated that one of the single-locus assay had very high prevalence of false positives (Positive predictive value = 77.8%) and was excluded from further analysis. Analysis of 460 swab-derived samples indicated that the second single-locus assay misidentified 16 out of 219 MRSA's and 13 out of 90 methicillin-sensitive S. aureus's (MSSA) were misidentified as MRSA's. The double-locus detection assay misidentified 55 out of 90 MSSA's. 46 MSSA containing samples were misidentified as MRSA and 9 as other than S. aureus ending with low positive predicted value (<85%) and very low specificity (<62%). CONCLUSION: The results indicate that high prevalence of false-positive and false-negative reactions occurs in such assays.