Prevalence of Class 1 Integrons and Extended Spectrum Beta Lactamases among Multi-Drug Resistant Escherichia coli Isolates from North of Iran

• Published in: Iranian biomedical journal Vol. 19; no. 4; pp. 233 - 239
• Main Authors: Mehdipour Moghaddam, Mohammad Javad, Mirbagheri, Adeleh Alsadat, Salehi, Zivar, Habibzade, Seyyed Mahmood
• Format: Journal Article
• Language: English
• Published: Iran Pasteur Institute of Iran 01.10.2015
• Subjects: Anti-Bacterial Agents - pharmacology; beta-Lactamases - genetics; Drug Resistance, Multiple, Bacterial - genetics; Escherichia coli - drug effects; Escherichia coli - genetics; Escherichia coli - isolation & purification; Escherichia coli Infections - drug therapy; Escherichia coli Infections - epidemiology; Escherichia coli Infections - microbiology; Humans; Integrons - genetics; Iran - epidemiology; Microbial Sensitivity Tests; Original; Urinary Tract Infections - drug therapy; Urinary Tract Infections - epidemiology; Urinary Tract Infections - microbiology; Iran; Integrons; Antibiotic; Escherichia coli
• ISSN: 1028-852X; 2008-823X
• DOI: 10.7508/ibj.2015.04.007

Extended spectrum beta lactamases (ESBLs) are an important cause of transferable multidrug resistance (MDR) in gram-negative bacteria. The most described ESBL genes are generally found within integron-like structures as mobile genetic elements. The aim of this study was to identify the accompanying of class 1 integrons and ESBLs in the MDR E. coli isolates. Susceptibility to antimicrobial agents was determined for 33 E. coli strains by the disk diffusion method. Double-disk synergy test was applied for screening ESBL. To identify the strains carrying integrons, the conserved regions of integron-encoded integrase gene intI1 were amplified. For detection of gene cassettes, 5'CS and 3'CS primers were used. All E. coli isolates were identified as multi-drug resistant. More than 50% of the isolates were resistant to tetracycline, cephalothin, cefuroxime, amoxicillin-clavulanic acid, and third generation cephalosporines. Nearly all of the isolates displayed sensitivity to piperacillin. There was a significant correlation between production of ESBL and resistance to all antibiotics except for ciprofloxacin and piperacillin (P value less than 0.01). Thirty two MDR strains (97%) included class 1 integron, and some isolates that included integrons were similar in the size of gene cassettes. The isolates were different in the resistance profiles; however, some others had similar resistance profiles. Of eight ESBL positive isolates, seven (87.5%) carried class 1 integrons. Class 1 integrons were frequent in MDR and also ESBL-producing E. coli isolates. High prevalence of class 1 integrons confirms that integron-mediated antimicrobial gene cassettes are important in E. coli resistance profile.