Phenotypic and genotypic evaluation of ESBL- and AmpC-producing Escherichia coli isolated from chicken distributed in Birjand, East of Iran

Abstract The aims of the present study were to detect Escherichia coli in chicken distributed Birjand, investigate prevalence ESBL and AmpC beta-lactamases producers among them, identify their antibiotic resistance patterns. was conducted on 150 samples, antimicrobial susceptibility patterns determined by Kirby–Bauer disk diffusion method. Phenotypic identification performed combined test (CDT). specific genes detected using two multiplex PCR (m-PCR) assays. According our results, 116 out samples contaminated with E. . Moreover, highest isolates observed trimethoprim/sulfamethoxazole (46%), ampicillin (40%), amoxicillin (29.33%). In molecular confirmation step, 17 (11.33%) beta-lactamase producers, five contained bla CTX-M14 gene (3.33%), DHA (1.33%) CTX-M3 (1.33%), just one sample carried CMY-2 (0.66%). SHV TEM not any strains isolated from samples. This showed contamination antibiotic-resistant Therefore, it is recommended that veterinarians be more precautious prescribing antibiotics.