Zahra Abdolvand - Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Shahin Najar-Peerayeh - Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Bita Bakhshi - Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran

Background and Aim : Beta-lactam antibiotics are the most important drugs used to treat Enterobacteriaceae infections. The increase in asymptomatic carriers of ESBL-producing bacteria is a concern in the community. Thus this study aims to assess the prevalence of intestinal carriage of extended-spectrum β-lactamases(ESBLs) producing E.coli in children with mental disabilities under ۱۰ years.Methods : cefotaxime and ceftazidime discs were used to screen the ESBLs producing E.coli. The production of ESBLs was confirmed by double-disc synergy assay with amoxiclav, cefotaxime, and ceftazidime discs. TEM and CTX-M-۱ genes were identified by PCR. Antimicrobial susceptibility was performed by disk-diffusion method.Results : a total of ۷۱ ESBLs producing E.coli were isolated from ۱۱۰ volunteers. The highest prevalence was observed among children under ۴ years (۷۵%). ۱۹.۷% of isolates carried blaCTX-M-۱ and blaTEM simultaneously. ۸۴.۵% of isolates showed a multi-drug resistance phenotype. All isolates were resistant to cefotaxime. The most resistance rate was found to ceftazidime (۹۵.۶%) and aztreonam (۹۰.۱%) and the least resistance was observed in imipenem (۱.۴%). ۸۱.۷% showed resistance to trimethoprim/sulfamethoxazole,۴۹.۳% to tetracycline,۸۷.۳% to ciprofloxacin and amoxicillin/clavulanate,۱۴.۱% to gentamicin and ۴.۲% to meropenem.Conclusion : Our study shows evidence of a significant prevalence of carriers of ESBL-producing E.coli in children under the age of ten with a mental disability, especially under the age of four years. Efforts can be made to reduce ESBL carriers by modifying the infection control policy, banning the sale of over-the-counter antibiotics, and guiding people about the dangers of overuse of antibiotics.

Escherichia coli, ESBLs, Intestinal carriage, CTX-M-۱