Prevalence of CTX-M-1 gene in Escherichia coli isolated from broilers in Semnan province of Iran

Presence of Extended-Spectrum β-lactamase (ESBL) such as CTX-M is one of the major reasons for resistance of Enterobacteriaceae to β-lactam antibiotics. Since there is no detailed description in prevalence of CTX-M in Escherichia coli isolates in Semnan provine of Iran, the purpose of this study was determination of prevalence of production blaCTX-M type gene in broiler chicken farms in Semnan. In this study, of 156 isolates collected from poultry farms and veterinary laboratories, 100 strains includes 50 E. coli from cloac of apparently healthy broilers and 50 E. coli from viscera of broilers, which was isolated and purified by biochemical differential tests after confirmation. BlaCTX-Mgene was determined by PCR amplification. The results of this study showed that 18% (9 strains isolated from suspicious viscera and 9 strains from healthy birds) strains had blaCTX-M gene. According to the results, there was no significant difference between the two groups in the prevalence of blaCTX-Mgene, which indicates that healthy broilers in Semnan broiler farms could be as an important reservoir for dissemination of antimicrobial resistance by contaminating food chain. Therefore, it is necessary to plan continuous health care programs against the risk of the presence of ESBLs-causing microorganisms.