Phenotypic and genotypic detection of extended-spectrum β-lactamase (ESBL) producing Escherichia coli isolated from urinary tract infections in Zabol, Iran

摘要

Objective: To investigate the role of a rapid polymerase chain reaction (PCR) assay in comparison with traditional empiric therapy in detection of extended spectrum β-lactamase (ESBL) producer Escherichia coli (E. coli). Methods: Ninety isolates of E. coli from urinary tract infection were collected and screening of ESBL resistance using disc diffusion method, minimum inhibitory concentration (MIC) for ceftazidime and detection of TEM resistant gene by PCR were done. Results: The results of disc diffusion method showed that forty out of ninety E. coli isolates were ESBLs producing organisms. Antibiotic susceptibility of E. coli isolates to 9 antibacterial agents were evaluated. However, all isolated E. coli were resistant to all 9 antibacterial agents by these percentage: ceftriaxon (100%), ceftazidime (100%), amoxicillin (100%), erythromycin (100%), azithromycin (95%), cefixime (87.5%), tetracyclin (87.5%), nalidixic acid (85%) and difloxcain (75%). The abundance of antibiotic-resistant TEM gene according to PCR was 30%. Totally 82.5% of strains tested by MIC were observed as ceftazidime-resistant.Conclusions:We conclude that the TEM gene PCR assay is a rapid, sensitive and clinically useful test, particularly for the early detection of ESBLs-producing E. coli.