Commensal E. coli as an Important Reservoir of Resistance Encoding Genetic Elements

International Journal of Enteric Pathogens

article

Azam Mahmoudi-Aznaveh¹  Bita Bakhshi¹  Shahin Najar-Peerayeh¹  Anoshirvan Kazemnejad¹  Zahra Rafieepour²  Mohammad Rahbar³  Shahla Abbaspour⁴ 

[1] Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University;Food Microbiology Research Center, Tehran University of Medical Sciences;Antimicrobial Resistance Research center, Tehran University of Medical Sciences;Bahrami Hospital

关键词: Enteropathogenic;    E.coli;    Commensal;    Integron;    Resistance;   

DOI  :  10.17795/ijep13516

学科分类：农业科学（综合）

来源: Alborz University of Medical Sciences

【 摘 要 】

Background: Diarrheagenic E. coli is the most important cause of diarrhea in children and is a public health concern in developing countries. A major public problem is acquisition and transmission of antimicrobial resistance via mobile genetic elements including plasmids, conjugative transposons, and integrons which may occur through horizontal gene transfer. Objectives: The aim of this study was to investigate the distribution of class 1 and 2 integrons among commensal and enteropathogenic E. coli isolates and assess the role of commensal E. coli population as a reservoir in the acquisition and transmission of antimicrobial resistance. Materials and Methods: Swabs were collected directly from stool samples of the children with diarrhea admitted to three hospitals in Tehran, Iran during July 2012 through October 2012. Antimicrobial susceptibility testing and PCR analysis were performed for analysis of the resistance pattern and integron content of isolates. Results: A total of 20 enteropathogenic E.coli (identified as eae+stx1-stx2-) and 20 commensal E.coli were selected for analysis. The resistance pattern in commensal and pathogenic E.coli was very similar. In both groups a high rate of resistance was seen to tetracycline, streptomycin, cotrimoxazole, nalidixic acid, and minocycline. Of 20 EPEC strains, 3 strains (15 %) and 1 strain (5%) had positive results for int and hep genes, respectively. Among 20 commensal, 65% (13 strains) and 10% (2 strains) had positive results for int and hep genes, respectively. Conclusions: The higher rate of class 1 integron occurrence among commensal population proposes the commensal intestinal organisms as a potential reservoir of mobile resistance gene elements which could transfer the resistance gene cassettes to other pathogenic and/or nonpathogenic organisms in the intestinal lumen at different occasions.

【 授权许可】

CC BY-NC