scholarly journals Comprehensive Identification of Fim-Mediated Inversions in Uropathogenic Escherichia coli with Structural Variation Detection Using Relative Entropy

2018 ◽  
Author(s):  
Colin W. Russell ◽  
Rashmi Sukumaran ◽  
Lu Ting Liow ◽  
Balamurugan Periaswamy ◽  
Shazmina Rafee ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Relative Entropy ◽  
Structural Variation ◽  
Infection Type ◽  
Uropathogenic Escherichia Coli ◽  
Structural Variations ◽  
Type 1 Pili ◽  
Bladder Cells ◽  
Tract Infections

Most urinary tract infections (UTIs) are caused by uropathogenic Escherichia coli (UPEC), which depend on an extracellular organelle (Type 1 pili) for adherence to bladder cells during infection. Type 1 pilus expression is partially regulated by inversion of a piece of DNA referred to as fimS, which contains the promoter for the fim operon encoding Type 1 pili. fimS inversion is regulated by up to five recombinases collectively known as Fim recombinases. These Fim recombinases are currently known to regulate two other switches: the ipuS and hyxS switches. A long-standing question has been whether the Fim recombinases regulate the inversion of other switches, perhaps to coordinate expression for adhesion or virulence. We answered this question using whole genome sequencing with a newly developed algorithm (Structural Variation detection using Relative Entropy, SVRE) for calling structural variations using paired-end short read sequencing. SVRE identified all of the previously known switches, refining the specificity of which recombinases act at which switches. Strikingly, we found no new inversions that were mediated by the Fim recombinases. We conclude that the Fim recombinases are each highly specific for a small number of switches. We hypothesize that the unlinked Fim recombinases have been recruited to regulate fimS, and fimS only, as a secondary locus; this further implies that regulation of Type 1 pilus expression (and its role in gastrointestinal and/or genitourinary colonization) is important enough, on its own, to influence the evolution and maintenance of multiple additional genes within the accessory genome of E. coli.

scholarly journals Comprehensive Identification of Fim-Mediated Inversions in UropathogenicEscherichia coliwith Structural Variation Detection Using Relative Entropy

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Colin W. Russell ◽  
Rashmi Sukumaran ◽  
Lu Ting Liow ◽  
Balamurugan Periaswamy ◽  
Shazmina Rafee ◽  
...  
Keyword(s):  
Relative Entropy ◽  
Structural Variation ◽  
Infection Type ◽  
Epigenetic Mechanism ◽  
Structural Variations ◽  
Entire Genome ◽  
Content Type ◽  
Type 1 Pili ◽  
Tract Infections

ABSTRACTMost urinary tract infections (UTIs) are caused by uropathogenicEscherichia coli(UPEC), which depends on an extracellular organelle (type 1 pili) for adherence to bladder cells during infection. Type 1 pilus expression is partially regulated by inversion of a piece of DNA referred to asfimS, which contains the promoter for thefimoperon encoding type 1 pili.fimSinversion is regulated by up to five recombinases collectively known as Fim recombinases. These Fim recombinases are currently known to regulate two other switches: theipuSandhyxSswitches. A long-standing question has been whether the Fim recombinases regulate the inversion of other switches, perhaps to coordinate expression for adhesion or virulence. We answered this question using whole-genome sequencing with a newly developed algorithm (structural variation detection using relative entropy [SVRE]) for calling structural variations using paired-end short-read sequencing. SVRE identified all of the previously known switches, refining the specificity of which recombinases act at which switches. Strikingly, we found no new inversions that were mediated by the Fim recombinases. We conclude that the Fim recombinases are each highly specific for a small number of switches. We hypothesize that the unlinked Fim recombinases have been recruited to regulatefimS, andfimSonly, as a secondary locus; this further implies that regulation of type 1 pilus expression (and its role in gastrointestinal and/or genitourinary colonization) is important enough, on its own, to influence the evolution and maintenance of multiple additional genes within the accessory genome ofE. coli.IMPORTANCEUTI is a common ailment that affects more than half of all women during their lifetime. The leading cause of UTIs is UPEC, which relies on type 1 pili to colonize and persist within the bladder during infection. The regulation of type 1 pili is remarkable for an epigenetic mechanism in which a section of DNA containing a promoter is inverted. The inversion mechanism relies on what are thought to be dedicated recombinase genes; however, the full repertoire for these recombinases is not known. We show here that there are no additional targets beyond those already identified for the recombinases in the entire genome of two UPEC strains, arguing that type 1 pilus expression itself is the driving evolutionary force for the presence of these recombinase genes. This further suggests that targeting the type 1 pilus is a rational alternative nonantibiotic strategy for the treatment of UTI.

scholarly journals Pectic Oligosaccharides from Cranberry Prevent Quiescence and Persistence in the Uropathogenic Escherichia coli CFT073

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiadong Sun ◽  
Robert W. Deering ◽  
Zhiyuan Peng ◽  
Laila Najia ◽  
Christina Khoo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Chemical Compounds ◽  
Uropathogenic Escherichia Coli ◽  
Cranberry Juice ◽  
Persister Cells ◽  
E Coli ◽  
Pectic Oligosaccharides ◽  
Bladder Cells ◽  
Strain Cft073 ◽  
Tract Infections

AbstractUrinary tract infections (UTIs) caused by Escherichia coli create a large burden on healthcare and frequently lead to recurrent infections. Part of the success of E. coli as an uropathogenic bacterium can be attributed to its ability to form quiescent intracellular reservoirs in bladder cells and its persistence after antibiotic treatment. Cranberry juice and related products have been used for the prevention of UTIs with varying degrees of success. In this study, a group of cranberry pectic oligosaccharides (cPOS) were found to both inhibit quiescence and reduce the population of persister cells formed by the uropathogenic strain, CFT073. This is the first report detailing constituents of cranberry with the ability to modulate these important physiological aspects of uropathogenic E. coli. Further studies investigating cranberry should be keen to include oligosaccharides as part of the ‘active’ cocktail of chemical compounds.

scholarly journals Establishment of a Persistent Escherichia coli Reservoir during the Acute Phase of a Bladder Infection

2001 ◽  
Vol 69 (7) ◽  
pp. 4572-4579 ◽  
Author(s):  
Matthew A. Mulvey ◽  
Joel D. Schilling ◽  
Scott J. Hultgren
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Epithelial Cells ◽  
Urinary Tract Infections ◽  
Bacterial Attachment ◽  
Bacterial Invasion ◽  
E Coli ◽  
Bladder Cells ◽  
Tract Infections

ABSTRACT The vast majority of urinary tract infections are caused by strains of uropathogenic Escherichia coli that encode filamentous adhesive organelles called type 1 pili. These structures mediate both bacterial attachment to and invasion of bladder epithelial cells. However, the mechanism by which type 1 pilus-mediated bacterial invasion contributes to the pathogenesis of a urinary tract infection is unknown. Here we show that type 1-piliated uropathogens can invade the superficial epithelial cells that line the lumenal surface of the bladder and subsequently replicate, forming massive foci of intracellular E. coli termed bacterial factories. In response to infection, superficial bladder cells exfoliate and are removed with the flow of urine. To avoid clearance by exfoliation, intracellular uropathogens can reemerge and eventually establish a persistent, quiescent bacterial reservoir within the bladder mucosa that may serve as a source for recurrent acute infections. These observations suggest that urinary tract infections are more chronic and invasive than generally assumed.

scholarly journals A host receptor enables type 1 pilus-mediated pathogenesis of Escherichia coli pyelonephritis

2021 ◽  
Vol 17 (1) ◽  
pp. e1009314
Author(s):  
Lisa K. McLellan ◽  
Michael R. McAllaster ◽  
Arthur S. Kim ◽  
Ľubomíra Tóthová ◽  
Patrick D. Olson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Infection Type ◽  
Collecting Duct ◽  
Binding Pocket ◽  
Lectin Domain ◽  
Type 1 Pili ◽  
Crispr Screen ◽  
Bacterial Mutants

Type 1 pili have long been considered the major virulence factor enabling colonization of the urinary bladder by uropathogenic Escherichia coli (UPEC). The molecular pathogenesis of pyelonephritis is less well characterized, due to previous limitations in preclinical modeling of kidney infection. Here, we demonstrate in a recently developed mouse model that beyond bladder infection, type 1 pili also are critical for establishment of ascending pyelonephritis. Bacterial mutants lacking the type 1 pilus adhesin (FimH) were unable to establish kidney infection in male C3H/HeN mice. We developed an in vitro model of FimH-dependent UPEC binding to renal collecting duct cells, and performed a CRISPR screen in these cells, identifying desmoglein-2 as a primary renal epithelial receptor for FimH. The mannosylated extracellular domain of human DSG2 bound directly to the lectin domain of FimH in vitro, and introduction of a mutation in the FimH mannose-binding pocket abolished binding to DSG2. In infected C3H/HeN mice, type 1-piliated UPEC and Dsg2 were co-localized within collecting ducts, and administration of mannoside FIM1033, a potent small-molecule inhibitor of FimH, significantly attenuated bacterial loads in pyelonephritis. Our results broaden the biological importance of FimH, specify the first renal FimH receptor, and indicate that FimH-targeted therapeutics will also have application in pyelonephritis.

scholarly journals Human Urine Decreases Function and Expression of Type 1 Pili in Uropathogenic Escherichia coli

mBio ◽  
2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Sarah E. Greene ◽  
Michael E. Hibbing ◽  
James Janetka ◽  
Swaine L. Chen ◽  
Scott J. Hultgren
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Human Urine ◽  
Phase Variable ◽  
Bladder Epithelium ◽  
Content Type ◽  
Type 1 Pili ◽  
Tract Infections

ABSTRACTUropathogenicEscherichia coli(UPEC) is the primary cause of community-acquired urinary tract infections (UTIs). UPEC bind the bladder using type 1 pili, encoded by thefimoperon in nearly allE. coli. Assembled type 1 pili terminate in the FimH adhesin, which specifically binds to mannosylated glycoproteins on the bladder epithelium. Expression of type 1 pili is regulated in part by phase-variable inversion of the genomic element containing thefimSpromoter, resulting in phase ON (expressing) and OFF (nonexpressing) orientations. Type 1 pili are essential for virulence in murine models of UTI; however, studies of urine samples from human UTI patients demonstrate variable expression of type 1 pili. We provide insight into this paradox by showing that human urine specifically inhibits both expression and function of type 1 pili. Growth in urine induces thefimSphase OFF orientation, preventingfimexpression. Urine also contains inhibitors of FimH function, and this inhibition leads to a further bias infimSorientation toward the phase OFF state. The dual effect of urine onfimSregulation and FimH binding presents a potential barrier to type 1 pilus-mediated colonization and invasion of the bladder epithelium. However, FimH-mediated attachment to human bladder cells during growth in urine reverses these effects such thatfimexpression remains ON and/or turns ON. Interestingly, FimH inhibitors called mannosides also induce thefimSphase OFF orientation. Thus, the transduction of FimH protein attachment or inhibition into epigenetic regulation of type 1 pilus expression has important implications for the development of therapeutics targeting FimH function.IMPORTANCEUrinary tract infections (UTIs) are extremely common infections, frequently caused by uropathogenicEscherichia coli(UPEC), that are treated with antibiotics but often recur. Therefore, UTI treatment both is complicated by and contributes to bacterial antibiotic resistance. Thus, it is important to understand UTI pathogenesis to devise novel strategies and targets for prevention and treatment. Based on evidence from disease epidemiology and mouse models of infection, UPEC relies heavily on type 1 pili to attach to and invade the bladder epithelium during initial stages of UTI. Here, we demonstrate that the negative effect of planktonic growth in human urine on both the function and expression of type 1 pili is overcome by attachment to bladder epithelial cells, representing a strategy to subvert this alternative innate defense mechanism. Furthermore, this dually inhibitory action of urine is a mechanism shared with recently developed anti-type 1 pilus molecules, highlighting the idea that further development of antivirulence strategies targeting pili may be particularly effective for UPEC.

Aqueous Root Extract from Ononis spinosa Exerts Anti-adhesive Activity against Uropathogenic Escherichia coli

Planta Medica ◽  
2020 ◽  
Vol 86 (04) ◽  
pp. 247-254 ◽  
Author(s):  
Melanie Deipenbrock ◽  
Jandirk Sendker ◽  
Andreas Hensel
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Cell Viability ◽  
Urinary Tract Infections ◽  
Bacterial Adhesion ◽  
Uropathogenic Escherichia Coli ◽  
E Coli ◽  
T24 Cells ◽  
Bladder Cells ◽  
Tract Infections

AbstractExtracts from Ononis spinosa are traditionally used for urinary tract infections due to diuretic and anti-inflammatory activity. A potential influence on the virulence of uropathogenic Escherichia coli has not been investigated until now. The following study aimed to investigate the influence of an aqueous O. spinosa extract on uropathogenic E. coli and uropathogenic E. coli host cell interaction. A hot water extract from the roots of O. spinosa (O. spinosa extract) was characterized by LC-qTOF-MS. The influence of O. spinosa extract on the proliferation of uropathogenic E. coli UTI89 and on cell viability against human T24 bladder cells was investigated. Anti-adhesive activity of O. spinosa extract was assessed by flow cytometry, evaluating the adhesion of fluorescent-labelled UTI89 to T24 bladder cells. Internalization of uropathogenic E. coli into T24 cells was monitored by an invasion assay. O. spinosa extract was characterized by the presence of isoflavones, isoflavanones, licoagrosides, pterocarpans, tartaric acid derivatives, and saponines. O. spinosa extract had no influence on the proliferation of uropathogenic E. coli (125 – 1000 µg/mL) and did not influence the cell viability of T24 cells. Bacterial adhesion to T24 cells was significantly (p > 0.001) inhibited by O. spinosa extract in a concentration-dependent manner (125 – 1000 µg/mL) during coincubation. Preincubation of uropathogenic E. coli or T24 cells with O. spinosa extract reduced bacterial adhesion, but to a lower extent than during coincubation. Consequently, the reduced bacterial adhesion also leads to a reduced internalization of uropathogenic E. coli uropathogenic E. coli into the host cell. O. spinosa extract does not interact with FimH-mediated uropathogenic E. coli adhesion to host cells. From these data, the traditional use of O. spinosa extracts for urinary tract infections seems to be rationalized.

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