Identification of Extended – Spectrum β - Lactamases and Metallo - Beta- Lactamases Producing Escherichia Coli and Klebsiella Pneumoniae Strains Isolated from Stool Samples of Dogs and Cats

Background and aim: bacterial infections are the most frequently occurring infections in pets. escherichia coli (e. coli) and klebsiella pneumoniae (k. pneumoniae) have been recognized as two opportunistic pathogens that are prevalent in pets. the aforementioned organisms play a vital role in the development and propagation of infections that affect the urinary tract, respiratory system, and gastrointestinal tract. the growing emergence of multidrug resistance among the bacteria is a global concern. the investigation of antibiotic resistance and genotypic characterization of extended- spectrum β-lactamases (esbls) and metallo - β - lactamase (mbl) - producing enterobacteriaceae (cpe) in companion animals in iran has been infrequently documented. the aim of this study was to identify the phenotypic and genotypic characterization of esbl and mbl - producing escherichia coli and klebsiella pneumoniae strains that were isolated from stool samples of dogs and cats.methods: a total of 65 stool samples of dogs and cats were collected from five veterinary hospitals between february to august 2022. the antimicrobial susceptibility test (ast) was evaluated by using disk diffusion according to the clinical and laboratory standards institute guidelines (clsi). the detection of esbls and mbls producing isolates was performed by combination disk diffusion test (cddt). the presence of blactxm, blatem, blashv, blandm, blavim, blaimp genes was detected by pcr technique. results: among 65 samples, 24 e. coli and 6 k. pneumoniae strains were identified. according to our findings, the most effective antibiotics against bacterial isolates were piperacillin - tazobactam imipenem and meropenem, respectively. the prevalence of esbl and mbl was found to be 66.66% and 0%, respectively. the pcr assay revealed the presence of blactxm-15, blatem, blashv, blaimp genes 28, 28, 18, 1 number, respectively. whereas blandm, and blavim genes were not detected.conclusion: the increasing prevalence of antibiotic resistance genes is a significant concern in the field of medicine. the excessive utilization of antibiotics may lead to the acquisition of genes that contribute to resistance.