Comparison of virulence genes and phylogenetic groups of Escherichia coli isolates from urinary tract infections and normal fecal flora

Abstract

IntroductionEscherichia coli is the most common cause of urinary tract infections (UTI). The gut is a suggested to be a common pool of E. coli isolates causing UTIs. The aim of present study was determination of phylogenetic groups in UTI and normal fecal flora isolates of E. coli and to compare the presence of virulence genes between these isolates. Material and methodsA total of 100 E. coli comprising 50 nonduplicated isolates from UTI and 50 isolates from fecal flora were collected in this study. All these isolates were identification by routine biochemical tests. Virulence genes were determined by the PCR method. Phylogenetic groups were determined using PCR and multiplexes PCR method. ResultsThe fyuA and iucD genes were the most common virulence factors among both UTIs and fecal flora isolates. The virulence genes vat, chuA, iroN was found to be significantly dominant in the UTI isolates compared to the fecal flora isolates (P < .05). vat gene was only detected in the UTIs isolates. Most of the isolates were in the phylogroups B1 and D. However, significantly higher isolates from UTIs belonged to the phylogroup B2 and D and the fecal flora in the phylogroup B1 and clade 1. The prevalence of vat and yfcV genes was significantly higher in the phylogroupB2 and vat gene in group D. ConclusionsThis study showed that the E. coli isolates from UTIs have significantly higher numbers of virulence genes compared to the fecal flora, and the phylogroups of these isolates were not the same. Study with the higher number of isolates is recommended for a better characterization of E. coli causing UTIs.