Flagella allow uropathogenic Escherichia coli ascension into murine kidneys

Schwan, William R.

doi:10.1016/j.ijmm.2007.05.009

Cited by 32 publications

(33 citation statements)

References 27 publications

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“…Motility is a known fitness trait of uropathogenic E. coli strains in the urinary tract and is needed for ascension of the ureters to reach the kidneys (13,53,54). Recent studies indicate that YcgR can bind c-di-GMP and then interact with the flagellar motor.…”

Section: Resultsmentioning

confidence: 99%

Genetic Analysis of the Role of yfiR in the Ability of Escherichia coli CFT073 To Control Cellular Cyclic Dimeric GMP Levels and To Persist in the Urinary Tract

et al. 2013

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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 ⌬yfiR 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.

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Section: Resultsmentioning

confidence: 99%

Genetic Analysis of the Role of yfiR in the Ability of Escherichia coli CFT073 To Control Cellular Cyclic Dimeric GMP Levels and To Persist in the Urinary Tract

et al. 2013

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“…In addition, our data suggest that flagellum-mediated motility or a proposed architectural function (42) is dispensable for CAUTI persistence once bacteria have colonized the bladder urine. The role of flagella during CAUTI pathogenicity is more likely to be relevant during onset of infection when bacteria ascend through the urethra to reach the bladder or up the urethers into the kidneys (43).…”

Section: Discussionmentioning

confidence: 99%

Type 1 Fimbriae Contribute to Catheter-Associated Urinary Tract Infections Caused by Escherichia coli

Reisner¹,

Maierl²,

Jörger³

et al. 2013

Journal of Bacteriology

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Biofilm formation on catheters is thought to contribute to persistence of catheter-associated urinary tract infections (CAUTI), which represent the most frequent nosocomial infections. Knowledge of genetic factors for catheter colonization is limited, since their role has not been assessed using physicochemical conditions prevailing in a catheterized human bladder. The current study aimed to combine data from a dynamic catheterized bladder model in vitro with in vivo expression analysis for understanding molecular factors relevant for CAUTI caused by Escherichia coli. By application of the in vitro model that mirrors the physicochemical environment during human infection, we found that an E. coli K-12 mutant defective in type 1 fimbriae, but not isogenic mutants lacking flagella or antigen 43, was outcompeted by the wild-type strain during prolonged catheter colonization. The importance of type 1 fimbriae for catheter colonization was verified using a fimA mutant of uropathogenic E. coli strain CFT073 with human and artificial urine. Orientation of the invertible element (IE) controlling type 1 fimbrial expression in bacterial populations harvested from the colonized catheterized bladder in vitro suggested that the vast majority of catheter-colonizing cells (up to 88%) express type 1 fimbriae. Analysis of IE orientation in E. coli populations harvested from patient catheters revealed that a median level of ϳ73% of cells from nine samples have switched on type 1 fimbrial expression. This study supports the utility of the dynamic catheterized bladder model for analyzing catheter colonization factors and highlights a role for type 1 fimbriae during CAUTI.

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“…Type 1 fimbriae, expressed on the surfaces of E. coli and most of the Enterobacteriaceae (11), have been shown to be critical for colonization of the bladder by UPEC (27), and accordingly, genes encoding these fimbriae are highly expressed in vivo (53). While type 1 fimbriae allow UPEC to bind mannose-containing glycoprotein receptors, such as uroplakin (46,61), and establish infection in the bladder, our laboratory (33) and another (51) have recently shown that flagella allow UPEC to ascend from the bladder to the kidneys. Furthermore, flagellum production contributes to the fitness of UPEC during murine urinary tract colonization (34,60).…”

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confidence: 95%

Multiple Genes Repress Motility in Uropathogenic Escherichia coli Constitutively Expressing Type 1 Fimbriae

Simms

Mobley

2008

J Bacteriol

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Two surface organelles of uropathogenic Escherichia coli (UPEC), flagella and type 1 fimbriae, are critical for colonization of the urinary tract but mediate opposite actions. Flagella propel bacteria through urine and along mucus layers, while type 1 fimbriae allow bacteria to adhere to specific receptors present on uroepithelial cells. Constitutive expression of type 1 fimbriae leads to repression of motility and chemotaxis in UPEC strain CFT073, suggesting that UPEC may coordinately regulate motility and adherence. To identify genes involved in this regulation of motility by type 1 fimbriae, transposon mutagenesis was performed on a phase-locked type 1 fimbrial ON variant of strain CFT073 (CFT073 fim L-ON), followed by a screen for restoration of motility in soft agar. Functions of the genes identified included attachment, metabolism, transport, DNA mismatch repair, and transcriptional regulation, and a number of genes had hypothetical function. Isogenic deletion mutants of these genes were also constructed in CFT073 fim L-ON. Motility was partially restored in six of these mutants, including complementable mutations in four genes encoding known transcriptional regulators, lrhA, lrp, slyA, and papX; a mismatch repair gene, mutS; and one hypothetical gene, ydiV. Type 1 fimbrial expression in these mutants was unaltered, and the majority of these mutants expressed larger amounts of flagellin than the fim L-ON parental strain. Our results indicate that repression of motility in CFT073 fim L-ON is not solely due to the constitutive expression of type 1 fimbriae on the surfaces of the bacteria and that multiple genes may contribute to this repression.

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Flagella allow uropathogenic Escherichia coli ascension into murine kidneys

Cited by 32 publications

References 27 publications

Genetic Analysis of the Role of yfiR in the Ability of Escherichia coli CFT073 To Control Cellular Cyclic Dimeric GMP Levels and To Persist in the Urinary Tract

Genetic Analysis of the Role of yfiR in the Ability of Escherichia coli CFT073 To Control Cellular Cyclic Dimeric GMP Levels and To Persist in the Urinary Tract

Type 1 Fimbriae Contribute to Catheter-Associated Urinary Tract Infections Caused by Escherichia coli

Multiple Genes Repress Motility in Uropathogenic Escherichia coli Constitutively Expressing Type 1 Fimbriae

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