Molecular Evaluation of Carbapenemasegenes NDM and OXA48among Escherichia coli Isolated from Urinary Tract InfectionPatients

Background and objectives: Urinary tract infections (UTIs) caused by Uropathogenic Escherichia coli (UPEC) are among the most common infectious diseases. Misuse use of antibiotics results in the drug resistance in UPECandcomplicatesthe clinical management of UTIs. Occurrence of enzymes inactivating carbapenem antibiotics is a new problem in treatment of UTI patients.Carbapenemasessuch as NDM and OXA48are a diverse set of enzymes that catalyze the hydrolysis of a broad range of β-lactam drugs including carbapenems .The objective of this study was to investigate the prevalence of Carbapenemases enzyme NDM and OXA48 among UPEC isolated from different hospitals in Tehran, Iran. Materials and Methods: In this study, 100 UPEC were collected from UTI patients from different hospitals in Tehran, Iran. After bacteriological and biochemical confirmation of the isolates in Department of Molecular Biology, Pasteur Institute of Iran, antibiotic resistance to antibiotics ertapenem and imipenem was assayed using the disk diffusion method. Then, Polymerase Chain Reaction (PCR) assay was used to determinethe prevalence ofCarbapenemases enzymesNDM and OXA48genes using specific primers. Results: According to the results, of the 100 isolates, 12 (12%) isolates were resistant to carbapenem antibiotics. Among them, 8% (n =8) isolates harbored bla-OXA48, whereas the bla-NDMgene was not detected in the isolates. Conclusion: Fortunately,Carbapenemases prevalence is still low in our hospitals. However, to prescribe suitable antimicrobial therapy and to prevent resistant dissemination, early detection of Carbapenemases-producing isolates is crucial. Investigationof other Carbapenemasesencoding genes is under way.