Background and Aim: The emergence of carbapenemase - producing Enterobacteriaceae is a major concern to public health. The aim of this study was molecular detection of carbapenemase - producing Escherichia coli isolates collected from a university hospital in Tehran, Iran.
Methods: From March 2015 to May 2016, thirty eight E.coli clinical isolates with reduced susceptibility to carbapenems were collected. Antibiotic susceptibility tests were performed using the disc diffusion method. The Modified Hodge Test (MHT) was performed for the screening of carbapenemases. PCR and nucleotide sequenc ing were employed to screen for the presence of carbapenemase - encoding genes, including blaKPC, blaVIM, blaIMP, blaNDM−1 and blaOXA−48. The clonal relationship among isolates was analyzed by pulsed - field gel electrophoresis (PFGE).
Results: All of the isola tes were resistant or intermediately susceptible to ertapenem. Only ten of the isolates also exhibited resistance to both imipenem and meropenem. The resistance rate to cephalosporins and ciprofloxacin was high. MHT was positive in 15 (39.4%) isolates. PCR and sequencing analysis revealed that the 8 (21%) isolates harbored the blaOXA - 48 gene. We did not detect blaKPC, blaNDM−1, blaIMP and blaVIM among the isolates. Six isolates contained blaOXA - 48 carbapenemase belonged to different PFGE clone and two isola tes belonged to a same clone.
Conclusion: In this study, we report the first detection of E.coli harboring the blaOXA - 48 gene in Iran. PFGE showed that the dissemination of blaOXA - 48 gene was not spread by a single clone. Our results show that OXA - 48 - produc ing E.coli have started to spread into the hospitas in Iran, and detection of these isolates in Iran is important to prevent its rapid spread.