Molecular basis of commensalism in the urinary tract: low virulence or virulence attenuation?
In some patients Escherichia coli strains establish significant bacteriuria without causing symptoms of urinary tract infection (UTI). These asymptomatic bacteriuria (ABU) strains have been shown to express fewer virulence factors than the uropathogenic E. coli (UPEC) strains that cause severe, symptomatic UTI. Paradoxically, ABU strains carry many typical UPEC virulence genes, however, and the mo
