KguS/KguR two-component system as a molecular marker for E. coli strains associated with chronic urinary tract...

The identification of key genes responsible for the colonization and infection of E. coli strains associated with diarrhea (DEC) has made significant progress. Unfortunately, for uropathogenic E. coli (UPEC) strains, there are currently no defined genes that contribute to the identification of strains associated with urinary tract infections. This paper presents data regarding genes associated with the virulence and adaptability of UPEC strains isolated from urinary tract infections (UTI), aiming to evaluate the possibility of identifying a molecular marker for this pathotype. We analyzed 166 E. coli strains (90 recovered from urine and 76 isolated from feces) characterized by serotyping, phylogenetic analysis, and PCR detection of fimH, iutA, fyuA, feoB, ompT, kguS and kguR, genes associated with the virulence and metabolism of UPEC. Herein, results showed a higher prevalence of kguS/kguR combination in strains isolated from persistent UTI (peUTI), which correlated with strains of classic UPEC serogroups, a higher virulence gene load, and inclusion in pathogenic phylogroups (B2 and D). The presence of the genes in strains isolated from feces showed that the kguS/kguR presence was minimal (14%), while the presence of kguR was almost inexistent (1%), contrary to kguS (39%). The results obtained suggest that the presence of the kguS/kguR pair encoding the homonymous two-component system (TCS) plays an important role in the adaptation and colonization of the urinary tract by E. coli strains that cause UTI. In conclusion, the combination of kguS/kguR could be used as a molecular marker to identify pathogenic strains with a high capacity for adaptation to the urinary environment.