LAUSR

Abstract The objective of this study was to determine the prevalence of antibiotic resistant nontyphoidal Salmonella in 39 retail chicken meat shops located in 7 towns of North India. Overall, nontyphoidal Salmonella prevalence of 9.43% (70/742) was observed. Highest Salmonella prevalence was observed in Lalkuan (20.99%). Chicken meat samples (40%) showed highest Salmonella prevalence followed by poultry feces (20%). Three serotypes of Salmonella were identified, Salmonella Kentucky (S.Kentucky, 74.29%), Salmonella Virchow (S.Virchow, 17.14%) and Salmonella Typhimurium (S.Typhimurium, 7.14%). All isolates were multidrug resistant (MDR) by disk-diffusion assay, showing resistance to three or more classes of antibiotics. High resistance was observed to tetracycline (100%), erythromycin (100%), nalidixic acid (98.57%), ampicillin (95.71%) and ciprofloxacin (82.86%). Fifty-one (98.08%) S. Kentucky isolates were resistant to ciprofloxacin. Of these, 49 S. Kentucky isolates showed MIC values in the range of 3 to >256 μg/ml. Twenty-nine (41.43%) Salmonella isolates were co-resistant to ciprofloxacin and cefotaxime by disk-diffusion test. The tetA gene was detected in all Salmonella isolates and the blaTEM was the most predominant (25.37%) β-lactam gene. Multiple virulence genes such as sipA, mgtC, sopE1, stn, sopB, fliC, spvC and gipA were also detected. High resistance to quinolone, cephalosporin and tetracycline antibiotics in nontyphoidal Salmonella isolates of poultry origin points towards their extra-label use in poultry farms.