Escherichia coli FimH adhesins act synergistically with PapGII adhesins for enhancing establishment and maintenance of kidney infection

Abstract

Abstract Background: FimH adhesin is proposed to enhance Escherichia coli kidney infection by acting with PapGII adhesin, but genetic epidemiology study and animal study have not been widely conducted to confirm this hypothesis. Methods: We compared the prevalence of adhesin gene and their coexistent pattern between upper and lower urinary tract infection (UTI) strains. fimH mutant (EC114FM), papGII mutant (EC114PM) and fimH/papGII double mutant (EC114DM) were constructed from a pylonephritogenic strain (EC114). We compared among these strains for the infection ability in bladders and kidneys of female BALB/c mice challenged transurethrally with these bacteria and assessed 1, 3, and 7 days after inoculation. Results: Strains carrying fimH-only genotype were significantly more prevalent in lower UTI (P < 0.001). Strains carrying the fimH/papGII, but not papGII-only, were significantly associated with upper UTI (P Z 0.001). Incidence of kidney infection increased after inoculation with