Molecular Characterization of β-lactamase-producing multidrug-resistant Uropathogenic Escherichia coli isolated from urinary tract infections in southwest of Iran

BACKGROUND AND OBJECTIVESInfections with β-lactamase-producing multidrug-resistant E. coli is associated with poor outcomes due delays in initiation appropriate antimicrobial therapy and limited therapeutic options, leading to increase in social cost such as prolonged hospitalization and increased medical expenses. This study was aimed to characterized antimicrobial susceptibility patterns, ESBL phenotype, acquisition of β- lactamase genes, ERIC-PCR profile of β-lactamase-producing multidrug-resistant Uropathogenic Escherichia coli strains.MATERIALS AND METHODSThe cross-sectional study was conducted at Ahvaz Jundishapur University of Medical Sciences, Iran, between November ۲۰۱۵ and March ۲۰۱۶. Antimicrobial susceptibility tests were performed by disk diffusion method according to the CLSI guidelines and then, the ESBL production was phenotypically determined by both double disk synergy test and combined disk test. All multidrug-resistant strains of E. coli isolates were subjected to molecular analysis.RESULTS AND DISCUSSIONFrom total ۱۰۷ samples defined as ESBL positive by using drug susceptibility testing, ۵۵ MDR isolates were subjected to detection of the common ESBL genes and ERIC-PCR analysis. However, considerable resistance was observed to ampicillin (۹۸.۱%), piperacillin (۹۶.۴%) azithromycin (۸۳.۶%), cephalosporins (۸۵- ۹۲.۵%) and SXT (۸۰%). The presence of CTX-M gene was the most pronounced, followed TEM gene, then SHV genes. By ERIC-PCR, the high heterogeneity was observed among the isolates from UTIs including ۳۵ isolates which were categorized in ۱۷ clusters and ۲۰ single clones.CONCLUSIONDue to the high level of genotypic heterogeneity in MDR strains in the present study and the simultaneous presence of resistance extended spectrum beta-lactamases (ESBL) genes, it can be a warning danger to the health community that should be avoid to dispersal as soon as possible to prevent the further spread of these strains.