Antimicrobial resistance in bacteria from the family Enterobacteriaceae is an important indicator of the emergence of resistant bacterial strains in the gut microbiota. A total of 150 cloacal swabs were collected from free range chickens, 217 Enterobacteriaceae isolates were identified. This study investigated the antimicrobial susceptibility and resistance of commensal Enterobacteriaceae from free-range chickens to 14 antimicrobial agents using the disc diffusion method. Hundred per cent phenotypic resistance of the isolates was noticed against bacitracin, colistin, nitrofurazone, furazolidone, virginomycin, vancomycin and tylosine. Moderate resistance (70-25%) of isolates was noticed against doxycycline HCl, ampicillin, cefotaxime, ciprofloxacin and chloramphenicol. Least resistance (<25%) of isolates was recorded against enrofloxacin and gentamicin. The genotypic resistance of the Enterobacteriaceae to tetracycline was detected by targeting tet-A gene. About 90.9% of phenotypic resistant samples were found to harbour tet-A gene. Resistance to ampicillin was detected by targeting blaTEM gene and 90.55% of phenotypic resistant samples against ampicillin were found to have blaTEM gene.

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