Distribution of Tet, aac and Ctx-m genes among antibiotic resistant Escherichia coli isolated from poultry under various farming system of A and N Islands

Transmission of antibiotic resistance from animal food chain to human through animal food-borne pathogens have led to increased public concern. Wider surveillance on prevalence of antibiotic resistance in E. coli will provide information on evolution of resistance in various geographical locations. The purpose of this study was to investigate the presence of antimicrobial resistance of E. coli isolates from poultry under various farming system in A and N Islands and resistance genes of tet, ctx-M and aac encoding the isolates.

Isolates were obtained from cloacal swabs in poultry under various farming systems and tested against major antimicrobial derivatives to study multi drug resistance. The presence of genes associated with resistance to tetracycline (tet A), ESBL (CTX-M) and Gentamycin (aac(3)-IV) were determined by PCR.

A total of 126 cloacal samples were analysed out of which 31.38% of the E.coli isolates from poultry under various farming systems were producing extended spectrum beta-lactamases and were multiple antimicrobial resistant. Poultry birds of commercial farms showed higher resistance levels (37.5%) than organised farms (24.76%) and desi birds (31.88%). Results indicate a high level of multi-drug resistance is emerging even in desi birds. It is suggested that an antimicrobial resistance surveillance program is needed in A and N Islands in order to detect bacterial resistance among rural poultry production as the 80 percentage of total poultry population belong to desi birds.