Comparsion of virulence gene between Escherichia coli isolates from Urinary Tract Infections and normal fecal flora and their relationship with phylogenetic groups

Introduction and Objectives: Escherichia coli is the most prevalent facultative gram-negative bacillus in the human fecal flora, usually inhabits the colon as commensal. It’s the most common cause of the Urinary Tract Infections (UTI). UTI isolates have several virulence factors which may be different from the common normal fecal flora. The phylogeny of the E.coli species, with the identification of eight phylogroups (A, B1, B2, C, D, E, F and clad1) is linked to the lifestyle of the strains. The aim of present study was determination of new phylogenetic groups of UTI and normal fecal flora isolates E.coli and to compare the presence of several virulence factors between UTI and normal fecal flora. Materials and Methods: Totally 50 E.coli isolates from UTI and 50 E.coli isolates from normal fecal flora were tested. The PCR method was used for identification of virulent genes vat, chuA, fyuA, yfcv, iroN, iucD. The phylogenetic groups was performed using universal primers for quadruplex genotype (arpA, chuA, yjaA, tspE4.C2) for groups A, B1, B2, C, D and additional primers for identification of clade 1, E, F. Results: Virulence factor genes ( vat, chuA, iroN ) in UTI isolates was significantly higher than the isolates derived from normal fecal flora (P ≤ 0/001). Virulence factor gene vat was only isolated in UTI isolates and was not seen in fecal samples. In addition, the isolates from the UTI was mostly in Group D and isolates from the normal fecal flora was in clade1. Group E was not detected neither in fecal nor in UTI isolates. Conclusion: In conclusion, the isolates from UTI have more virulent factors that in fecal normal flora and the phylogenetic grouping showed the Group D to the more common in UTI and clade1 mostly in normal fecal flora.