Prevalence and molecular characterization of extended-spectrum b-Lactamases (blaTEM) producing Escherichia coli isolated from humans andfoods of animal origin in Chhattisgarh, India

The present study describes the prevalence of extended spectrum b-lactamases (ESBL) producing E. coli in raw chevon, milk and human samples in different districts of Chhattisgarh state. A total of 330 samples comprising of chevon (n=126), raw milk (n=104), human urine and stool (n=100) were collected from Bilaspur, Durg, Raipur, Rajnandgaon and Dhamtari districts of Chhattisgarh and processed for isolation of E. coli. The biochemically confirmed E. coli isolates were further screened of for the presence of blaTEM gene by PCR amplification. Analysis of samples indicated an overall prevalence of 31.52%. The highest prevalence of E. coli was recorded in fresh chevon samples (38.09%) followed by human urine samples (37.14%), human stool samples (30%) followed by milk samples (20.19%). In –vitro antibiotic sensitivity test of E. coli isolates revealed that all isolates to be highly sensitive towards imipenem, gentamicin, ciprofloxacin, amoxyclav, ampicillin, oxytetracyclin. The highest numbers of E. coli isolates were found resistant to erythromycin, cefotaxim, ceftazidime, cephalexin and cifixime. The 49 E. coli isolates were found to have Multiple Antibiotic Resistance (MAR) index more than 0.2, thus indicating indiscriminate use of antimicrobials. The 44 (42.3%) isolates were identified as presumptive ESBL producers and out of them 39.4% isolates were found to harbour the blaTEM gene on their plasmid DNA indicating the presence of multidrug resistant ESBL producing E. coli in foods of animal origin and human samples.