bis(3--5-)-cyclic-diguanylic-acid and Urinary-Tract-Infections

The

Topics: Animals; ATP-Binding Cassette Transporters; Cyclic GMP; Escherichia coli Infections; Escherichia coli Proteins; Fimbriae, Bacterial; Gene Expression Regulation, Bacterial; Humans; Mice; Multigene Family; Mutation; Operon; Phosphates; Phosphorus-Oxygen Lyases; Recombinases; Regulon; Transcription Factors; Urinary Bladder; Urinary Tract Infections; Uropathogenic Escherichia coli; Virulence

During urinary tract infections (UTIs), uropathogenic Escherichia coli must maintain a delicate balance between sessility and motility to achieve successful infection of both the bladder and kidneys. Previous studies showed that cyclic dimeric GMP (c-di-GMP) levels aid in the control of the transition between motile and nonmotile states in E. coli. The yfiRNB locus in E. coli CFT073 contains genes for YfiN, a diguanylate cyclase, and its activity regulators, YfiR and YfiB. Deletion of yfiR yielded a mutant that was attenuated in both the bladder and the kidneys when tested in competition with the wild-type strain in the murine model of UTI. A double yfiRN mutant was not attenuated in the mouse model, suggesting that unregulated YfiN activity and likely increased cytoplasmic c-di-GMP levels cause a survival defect. Curli fimbriae and cellulose production were increased in the yfiR mutant. Expression of yhjH, a gene encoding a proven phosphodiesterase, in CFT073 ΔyfiR suppressed the overproduction of curli fimbriae and cellulose and further verified that deletion of yfiR results in c-di-GMP accumulation. Additional deletion of csgD and bcsA, genes necessary for curli fimbriae and cellulose production, respectively, returned colonization levels of the yfiR deletion mutant to wild-type levels. Peroxide sensitivity assays and iron acquisition assays displayed no significant differences between the yfiR mutant and the wild-type strain. These results indicate that dysregulation of c-di-GMP production results in pleiotropic effects that disable E. coli in the urinary tract and implicate the c-di-GMP regulatory system as an important factor in the persistence of uropathogenic E. coli in vivo.

Topics: Animals; Bacterial Proteins; Cellulose; Cyclic GMP; Cytoplasm; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Fimbriae, Bacterial; Gene Deletion; Hydrogen Peroxide; Iron; Mice; Phosphorus-Oxygen Lyases; Urinary Tract; Urinary Tract Infections; Urine; Uropathogenic Escherichia coli