Association of integrons with multidrug-resistant isolates among phylogenic groups of uropathogenic Escherichia coli

Abstract

The aims of this study were to investigate the antibiotics susceptibility, multidrug- resistant (MDR) frequency and the association of integrons with MDR among phylogenic groups of uropathogenic E. coli (UPEC). In total, 176 non-duplicated UPEC isolates were collected from urinary tract infections (UTIs) specimens. The disk diffusion method was performed for determination of antibiotic susceptibility patterns. Phylogenetic grouping and the presence of integron-associated genes (int) were detected by the PCR technique. A high frequency of resistance was observed to cotrimoxazole (96.9%), ampicillin (85%), trimethoprim (80.1%) and cefazolin (79.6%); and 140 isolates (79.5%) were MDR. Carbapenems and fosfomycin were the most effective antibiotics. The majority of isolates (60.8%) belonged to the phylogenic group B2. Integrons were detected in 135 (76.7%) of isolates and, class I was the most common (63.6%) class. MDR isolates were found to be significantly associated with class І integrons. These isolates were found to be closely associated with the phylogenic group D (82%), however, the presence of class І integrons was higher among MDR isolates of the phylogroup B1. This pattern is believed to be due to other mechanisms such as the overexpression of the efflux pumps. Our findings show a significant correlation between MDR and the presence of class І integron. We conclude that class 1 integron plays an important role in the development of MDR UPEC, especially among the phylogroup B1.