Correlation of Escherichia coli Strains Isolated from Wild Bird Feces and Human Urinary Tract Infections from Phylogenetic Point of View

Abstract

Background: Escherichia coliis a typical occupant of the enteric system of vertebrates. Some E. coli strains are related to urinary tract infections (UTIs) in human. E. coli strains are divided namely to the four phylogenetic groups, A, B1, B2, and D. Some investigations have indicated the relationship between phylogenetic characteristics and pathogenicity of E. coli. Thus, determining the phylogeny of unknown E. coli strains may be useful in predicting the pathogenesis. Objectives: In the present study, we aimed to compare the distribution of E. coli phylogroups in human UTIs and wild bird feces as a possible source of infection for human in a cross-sectional survey. Methods: A total of 264 E. coli isolates were obtained from human UTIs and feces of wild birds around and phylogenetic determination was carried out using the Clermont Triplex-PCR technique. Results: Our results showed that phylogenetic group B2 strains were the most prevalent in UTI cases (47.2%) followed by group D (30.2%). Group B1 contained 32.5% of the isolates in feces of wild birds, followed by group A (27.5%). There was a significant difference in E. coli phylogeny between hosts so that groups B2 and D were more prevalent in human UTIs and groups B1 and A in wild birds. Also, when comparing the phylogroups within a host, group B1 showed a higher rate in wild birds than in human UTIs. Conclusions: Although the majority of isolates from wild birds belonged to nonpathogenic phylogenetic groups B1 and A, further research seems to necessary to assess the exact relation of wild birds as pathogen sources for human by genotyping E. coli strains via high throughput genotyping assays.