Identification and Characterization of the Role of the uropathogenic Escherichia coli
gene eco293 in urinary tract infection
確認並分析尿道致病性大腸桿菌 eco293 基因在泌尿道感染中所扮演的角色
Advisor：鄧景浩老師
Student：李 馨
Abstract
Uropathogenic Escherichia coli (UPEC), a member of extraintestinal pathogenic E. coli
(ExPEC), is account for >80% uncomplicated UTIs. It has been broadly accepted that UPEC may
have extra virulence factors in comparison with intestinal commensal E. coli. So far, a lot of
UTI-associated virulence factors have been identified, including adhesins ,toxins ,and multiple iron
acquisition systems. To investigate these virulence factors may provide a novel therapeutic and
preventive strategies against UTIs.
In our preliminary study, we found that the prevalence of eco293 gene was significantly
higher in UPEC strains then in commensal E. coli strains. Based on this epidemiological association
of the eco293 gene with UTI, we speculate that the eco293 gene is involved in the pathogenesis of
UPEC-caused UTI. The eco293 gene is a sinH gene homolog. sinH and its neighbor genes, sinI and
ratA, are located in a genomic island inserted in the region between yfgJ and xseA. It has been known
that sinH gene in the Salmonella typhimurium LT2 and meningitis-associated E. coli strain RS218
has been shown to contribute to bacterial adherence of host cells. Based on these findings, we further
speculate that eco293 gene may serve as a binding factor in UPEC pathogenesis.
To determine the role of eco293 in UPEC, we knocked out the genomic island containing
eco293 from a clinical UPEC strain, UTI89. Then thew wild-type UTI89 and mutant strains were
subjected to co-infection of the urinary tract in the murine model. The mutant showed significantly
decreased levels of bladder and kidney colonization in comparison with the wild type strain,
suggesting that the eco293-containing island is involved in the pathogenesis of UTI caused by
UPEC.
In the future, we will focus on two specific aims : (1) To determine which gene in the
eco293-containg island is involved in bladder and kidney colonization of UPEC . We expect that
eco293 is the major one responsible for these phenotypes. (2) To determine the host receptor that
interacts with the putative adherence factor encoded in the eco293-containg island.