| Escherichia coli is by far the most common cause of urinary tract infections (UTI) accounting for approximately 90% of all ambulatory UTI. Uropathogenic E. coli (UPEC) possess specific virulence factors that confer the organism's pathogenic potential and increase its ability to be transmitted, colonize a host, cause infection and symptomatic disease.; We integrated epidemiologic methods with molecular approaches to study UTI by evaluating large samples of bacteria from well-defined populations and linking bacterial factors with host and clinical information. By comparing the relative prevalence of three putative virulence genes, usp, iha, and iroN E coli, in UTI and non-UTI we learned that iroN E coli was strongly associated with UTI pathogenesis. We additionally found that usp may play a role in pyelonephritis and colonization of the periurethral area and iha did not occur more frequently in any of our UTI collection than in rectal isolates. By comparing co-colonization rates among couples where the woman did and did not have UTI we found that E. coli that caused UTI were nearly nine times more likely than other E. coli to be shared between sex partners after adjusting for non-independence of behaviors within a sexual partnership.; Three new regions of DNA were identified to be associated with the sharing of E. coli between sex partners; a putative membrane protein form Yersina pestis, designated Yersinia membrane protein homologue, ymph, a novel adhesin gene cluster, designated adhesin-associated with sexual partnership (aasp), and a 273 by open reading frame encoding a 11 kDa protein that is 38% similar to the transcriptional regulatory protein PapB found in the P pilus fimbrial gene system, which was designated, PapB homologue regulator (pbhr). pbhr does not localize near other fimbrial genes but is strongly associated epidemiologically to the aasp, suggesting a functional linkage.; Our combined molecular epidemiologic approach yielded a better understanding of the nature of UPEC by identifying factors associated with UPEC virulence during an infection and factors that promote the transmission of E. coli in the human population. |
