Molecular Epidemiology of ESBL Genes and Multi-Drug Resistance in Diarrheagenic Escherichia coli strains Isolated from Adults in Iran

Resistance to oxyimino cephalosporins antibiotics in Enterobacteriaceae is primarily done by the extended spectrum β-lactamases (ESBLs). Clear identification of risk factors for ESBL-producing infections is necessary. Therefore, efficient strategies can be developed to decrease outbreak of these infections. The aim of this study was to determine the antibacterial susceptibility and ESBLs pattern of diarrhogenic Escherichia coli (E. coli) strains isolated from adult patients. In the present study, Diarrheogenic E. coli strains were isolated from 54 patients from the University of Medical Sciences hospitals in Shiraz. Antimicrobial susceptibility testing was done by disk diffusion method by CLSI criteria. The presence of blaTEM, blaSHV and blaCTX-M genes was investigated by PCR using designated primers. The prevalence of ESBLs-producer E. coli strains was 12.96%. Antimicrobial resistance testing showed a high resistance to cefexime, trimethoprim-sulfamethoxazole, ampicillin and penicillin. Overall, β-lactamase genes were identified in 52 (96.30%) isolates which were identified as 45 (83.33%) blaTEM, 17 (31.48%) blaSHV and 11 (20.37%) blaCTX-M. ESBL-producer E. coli is very prevalent in Diarrheogenic strains isolated from adult patients. Also, this study clearly showed that the blaTEM gene for ESBL-producer E. coli was widespread in Iran.