Study of the presence of blaTEM, blaSHV and blaCTX-M genes in Escherichia coli strains isolated from sheep in Kerman province

The aim of this study was to the determination of prevalence of resistant Escherichia coli isolates to commonly used β-lactam antibiotics and some related resistance genes in sheep. Totally, 67 E. coli isolates from 67 healthy sheep were considered to determine resistance against 9 antibiotics belonging to commonly used beta-lactam antibiotics by disc diffusion method. Also, the presence of blaTEM, blaSHV and blaCTX-M genes was investigated by PCR. The results showed all isolates were resistant to at least one of the tested antibiotics. The high prevalence of resistant strains to cephalexin, cefotaxime and ceftazidime was 98.5%, 98.5% and 97%, respectively. Also, 5 samples (7.4%) were positive for ESBLs producing E. coli. The results of this study indicated an increasing rate of resistance to commonly used β-lactam antibiotics among sheep. Therefore, antibiotic prescription methods should be limited and prevention strategies should be considered against infections to avoid dissemination of antibiotic resistance in food-producing animals.