Extended Spectrum β-Lactamase-Producing Strains of Escherichia coli in Hospitalized Children in Isfahan, Iran

Background: Beta-lactam antibiotics such as long-spectrum cephalosporins and carbapenems are the empirical treatment against urinary tract infections (UTIs). The common mechanism of resistance to B-lactamas in Escherichia coli is producing of ESBLs. Objectives: The aims of this study was evaluation of the susceptibility of the ESBL-producing E. coli strains to ordinarily used antibiotics and to detect the presence of the four common ESBL genes: blaTEM, blaOXA, blaCTX-M and blaSHV using multiplex PCR method. Materials and Methods: In a retrospective cross sectional study conducted between ۲۰۱۲ and ۲۰۱۳, out of۱۴۵ strains of E. coli were isolated from hospitalized children with UTIs. Susceptibility test was performed by disc diffusion method. All isolates were also tested for ESBL by the standard CLSI double disk diffusion method, using cefotaxime/ clavulanic acid and ceftazidime/clavulanic acid disks. Multiplex PCR was performed for detect of blaCTX-MIV, blaOXA, blaTEM and blaSHV genes. Results: From ۱۴۵ strains of E. coli, ۵۱(۳۵.۲%) and ۶۱(۴۲.۱%) isolates were resistance to ceftazidime and cefotaxime, respectively. ESBL production was noted in ۵۹ (۴۰.۷%) strains. The amplification of β-lactamase genes showed the presence of blaCTX-M like genes in ۲۲ (۳۷.۹%) strains, blaTEM in ۴۲ (۷۲.۴%), blaSHV in ۷ (۱۱.۹%) and blaOXA in ۲۳ (۳۹%) of the total ۵۸ strains of E. coli. Conclusions: Our data showed that, the high prevalence of beta-lactamase genes among isolates, and it. Our findings may provide useful insights in replace of the appropriate antibiotics and it may also prevents of ESBLs, mediated resistance problem.