Comparison of Some Genetic Determinants in Escherichia coli Isolates From Human Urinary Tract Infection and Avian Colibacillosis in Semnan, Iran

BACKGROUND: Escherichia coli is a particularly complex species that is grouped into pathotypes of partly zoonotic intestinal pathogenic E. coli and extraintestinal pathogenic E. coli (ExPEC). Strains belonging to ExPEC are able to cause various clinical signs in hosts and due to similar genetic determinants, these hosts may act as a source of infection for each other. OBJECTIVES: Recent reports of outbreaks of human urinary tract infections (UTIs) have stimulated interest in the potential that E. coli from animals has to cause human UTIs via the food supply especially poultry meat, so we aimed to assess the genetic relationships between strains from these two hosts. METHODS: A total  of  260  E. coli  isolates  were  obtained  from human  UTI’s (160 strains) and  poultry colibacillosis cases (100 strains)  and  phylogenetic  grouping  was  done  based  on  the Triplex-PCR  method and virulence genotyping was carried out using a modified Tetraplex-PCR detecting hly, iucD, papEF and sfa/focDE genes. RESULTS: Statistical analysis of results demonstrated that prevalence of B2 & D phylogroups in human UTI’s (77%) and D & A groups in poultry strains (66%) are higher than others, considerably. Statistical analysis showed that distribution of A phylogroup within poultry isolates versus human and B2 phylogroup within human isolates versus poultry ones were higher, significantly. It was shown that iucD is noticeablymore prevalent in poultry strains rather than human isolates,. Also, sfa/focDE gene was significantly more distributed in human strains than poultry isolates. CONCLUSIONS: In sum, despite the minor genetic differences between isolates from both hosts, our results showed that there are major genetic similarities in E. coli isolates from human UTI and poultry colibacillosis cases in the region and these two hosts can play an important role as infection source for the other one.   ________________________________________________________________