Abstract
Background Bacterial urinary tract infections are extremely prevalent, with half of women having at least one infection at some point in their lives. Most often the causative pathogen is the common gut microbe Escherichia coli. One such E. coli, strain D3, caused a bladder infection in a male adult, and was resistant to multiple antibiotics. We sequenced and assembled the genome of D3, and present it along with a comparative analysis against other pathogenic and nonpathogenic E. Coli strains.
Results By comparing the predicted proteins of D3 with those from 5 uropathogenic and 7 nonpathogenic E. Coli strains, we generated a list of 38 genes present in most (4-5) pathogenic strains, but absent in all nonpathogenic strains. Among these were 9 proteins of the Pap fimbrial operon, which has previously been associated with cell adherence and the formation of biofilms. Lastly, we analyzed the list of predicted genes uniquely present in D3 compared to all other strains, and identified multiple transposable elements.
Conclusions The presence of fimbria in most pathogenic E. coli strains, and their absence in nonpathogenic ones, suggests that they play a role in pathogenicity, a notion supported by previous work. We also found that D3-specific genes are strongly enriched with transposases, recombinases, and integrase, suggesting that these mobile elements have been inserted or expanded in D3, relative to other strains in the study.