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 : Multidrug-resistant gram-negative bacteria are a serious threat to public health. In recent years, the production of extended-spectrum beta-lactamases (ESBLs) in the Enterobacteriaceae has increased significantly. Reports of carriers of ESBL-producing bacteria are significant in healthy individuals, especially children. This article aims to assess the prevalence of ESBL-producing Klebsiella carriers.Methods : Two cefotaxime and ceftazidime antibiotics were used to screen of ESBls producing bacteria. The production of ESBLs was confirmed by double-disc 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 ۲۴ ESBls-producing Klebsiella were isolated from ۳۳۲ volunteers. The highest prevalence was observed among children ۴ to ۶ years (۴۱.۷%). CTX-M-۱ was the most common ESBL gene (۶۶.۷%). ۱.۶% of isolates carried blaCTX-M-۱ and blaTEM simultaneously. ۸.۳% isolates carried only the blaTEM. The highest antibiotic resistance was observed in cefotaxime (۸۷.۵%) and ceftazidime (۸۷.۵%) and the lowest in gentamicin (۴.۲%). Resistance to trimethoprim/sulfamethoxazole, tetracycline, ciprofloxacin, aztreonam and amoxicillin/clavulanate antibiotics were ۷۹.۲%, ۶۲.۵%, ۱۳%, ۵۴.۲% and ۵۴.۲%, respectively. ۹۱.۷% and ۷۰.۸% of isolates were susceptible to imipenem and meropenem, respectively. ۹۵% of isolates exhibited multidrug resistance.Conclusion : This prevalence of ESBls-producing Klebsiella in healthy children under ۱۰ years is significant and poses a serious threat to community health. Carrying ESBL-producing organisms is a potential risk factor for transmission and spread of infection and requiring substantial monitoring and control over antibiotic use in agriculture and animal husbandry as well as against nosocomial infections.

Klebsiella, broad-spectrum beta-lactamases, intestinal carriers, CTX-M-۱