Distribution of Class 1 and 2 Integrons Among Salmonella Enterica Serovars Isolated from Iranian Patients

Abstract

© 2019 Ranjbar et al. Background: Salmonella enterica has become increasingly resistant to antimicrobial agents, partly as a result of genes carried by integrons. Objective: The aim of the present study was to investigate the prevalence of class 1 and 2 integrons and resistance to antimicrobial agents in clinical isolates of S. enterica. Methods: This study included all Salmonella isolates, recovered from patients with salmonellosis, admitted to Medical Children Hospital, Tehran, Iran during 2015-2016. Bacterial isolates were identified using standard biochemical and agglutination tests. Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute guidelines. The presence of class 1 and 2 integrons was investigated by Polymerase Chain Reaction (PCR) assay, using specific primers. Results: A total of 138 Salmonella strains were isolated and included in this study. Integrons were detected in 45 (32%) isolates. Class 1 and 2 integrons were detected in 24 (17.3%) and 21 (15.2%) isolates, respectively. All integron-positive isolates showed multidrug-resistant phenotypes. Resistance to more than three antimicrobial agents was observed in integron-positive isolates. Conclusions: Our findings showed that integrons were widely distributed among S. enterica isolates in Tehran. Class 1 integrons are more prevalent than class 2 integrons in Salmonella isolates, and there is an association with MDR patterns. Therefore, these integrons are more likely to be involved in the distribution of resistant phenotypes in Salmonella strains.