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Page No. : 37-41

ABSTRACT

Non-typhoidal serovars of Salmonella are associated with high morbidity and mortality leading to huge economic losses in India. As poultry are considered to be the main reservoirs of non-typhoidal Salmonella, retail chicken meat was collected from two northern districts (Kozhikode and Palakkad) of Kerala (n=200) to detect the prevalence and study the resistance of the isolates to tetracycline. The samples were subjected to conventional culture techniques followed by molecular confi rmation using invA and spvC genes. Salmonella was detected in 37% of the samples. The invA gene was detected in cent per cent of the isolates, nevertheless spvC could be detected only in 15.38% of the positive isolates. Phenotypic detection of tetracycline resistance was done by disc diff usion method and resistance was detected in 70.27% of the isolates. Two separate PCRs were standardised for the detection of tetA and tetB genes, which yielded amplicons at 209 and 169 base pairs, respectively. The tetA gene was detected in 57.69%, whereas tetB could not be detected in any of the tetracycline resistant isolates. The widespread use of tetracycline in therapy could have led to the high prevalence of tetracycline resistant Salmonella in chicken meat.
Keywords: Antimicrobial resistance, invA, salmonella, spvC, tetA, tetB, tetracycline