Phenotypic identification of metallo-beta-lactamase (MBL) in non-infectious children under three years old in Khuzestan province

Background and Aim : Commensal Escherichia coli, one of the most important bacteria of the gut microflora, is a reservoir of antimicrobial resistance (AMR) that able transfer resistance genes especially carbapenemase genes to the pathogenic microorganisms. The aim of the current study was phenotypic identification of metallo-beta-lactamase (MBL) among E. coli strains isolated from feces of non-infectious children under three years old in Khuzestan province.Methods : Two hundred one E. coli strains were collected and examined after culture in the proprietary media. The imipenem and meropenem resistance isolates were evaluated by phenotypic methods including combined disc test (CDT), double disc synergy test (DDST), modified carbapenem inactivation method (mCIM) and EDTA-CIM (eCIM) for the presence of MBL.Results : Out of ۲۰۱ isolates, ۴ (۱.۹۹%) strains were identified as MBL producer. Two and one isolates were positive by DDST and CDT respectively and identified as MBL producer. One isolates with eCIM not been identified as a producer of MBL. One E. coli isolate was negative by CDT and DDST, and it was positive by mCIM and eCIM. Therefore four isolates were considered as MBL-producers.Conclusion : The resistance against carbapenems, the last-line group of antibiotics against MDR Gram-negative bacteria, is increasing worldwide. The emergence of the strain MBL-producing commensal E. coli isolates that are not associated with any infectious diseases has thrown light on the fact that these isolates can act as a reservoir of antibiotic resistance genes and transfer them among commensal microorganisms, including into pathogens.

کلیدواژه ها:

Commensal Escherichia coli ، CDT ، DDST ، mCIM ، eCIM ، carbapenemase ، MBL