scholarly journals Differential Stability and Trade-Off Effects of Pathoadaptive Mutations in the Escherichia coli FimH Adhesin

2007 ◽  
Vol 75 (7) ◽  
pp. 3548-3555 ◽  
Author(s):  
Scott J. Weissman ◽  
Viktoriya Beskhlebnaya ◽  
Veronika Chesnokova ◽  
Sujay Chattopadhyay ◽  
Walter E. Stamm ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acute Cystitis ◽  
E Coli ◽  
Trade Offs ◽  
Genes Encoding ◽  
Differential Stability ◽  
Rolling Mode ◽  
Tract Infections ◽  
Pathoadaptive Mutations

ABSTRACT FimH is the tip adhesin of mannose-specific type 1 fimbriae of Escherichia coli, which are critical to the pathogenesis of urinary tract infections. Point FimH mutations increasing monomannose (1M)-specific uroepithelial adhesion are commonly found in uropathogenic strains of E. coli. Here, we demonstrate the emergence of a mixed population of clonally identical E. coli strains in the urine of a patient with acute cystitis, where half of the isolates carried a glycine-to-arginine substitution at position 66 of the mature FimH. The R66 mutation induced an unusually strong 1M-binding phenotype and a 20-fold advantage in mouse bladder colonization. However, E. coli strains carrying FimH-R66, but not the parental FimH-G66, had disappeared from the patient's rectal and urine samples collected from 29 to 44 days later, demonstrating within-host instability of the R66 mutation. No FimH variants with R66 were identified in a large (>600 strains) sequence database of fimH-positive E. coli strains. However, several strains carrying genes encoding FimH with either S66 or C66 mutations appeared to be relatively stable in the E. coli population. Relative to FimH-R66, the FimH-S66 and FimH-C66 variants mediated only moderate increases in 1M binding but preserved the ability to enhance binding under flow-induced shear conditions. In contrast, FimH-R66 completely lost shear-enhanced binding properties, with bacterial adhesion being inhibited by shear forces and lacking a rolling mode of binding. These functional trade-offs may determine the natural populational instability of this mutation or other pathoadaptive FimH mutations that confer dramatic increases in 1M binding strength.

scholarly journals Uropathogenic Escherichia coli Triggers Oxygen-Dependent Apoptosis in Human Neutrophils through the Cooperative Effect of Type 1 Fimbriae and Lipopolysaccharide

2004 ◽  
Vol 72 (8) ◽  
pp. 4570-4578 ◽  
Author(s):  
Robert Blomgran ◽  
Limin Zheng ◽  
Olle Stendahl
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Human Neutrophils ◽  
Dependent Manner ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
The Difference ◽  
Tract Infections ◽  
Neutrophil Survival

ABSTRACT Type 1 fimbriae are the most commonly expressed virulence factor on uropathogenic Escherichia coli. In addition to promoting avid bacterial adherence to the uroepithelium and enabling colonization, type 1 fimbriae recruit neutrophils to the urinary tract as an early inflammatory response. Using clinical isolates of type 1 fimbriated E. coli and an isogenic type 1 fimbria-negative mutant (CN1016) lacking the FimH adhesin, we investigated if these strains could modulate apoptosis in human neutrophils. We found that E. coli expressing type 1 fimbriae interacted with neutrophils in a mannose- and lipopolysaccharide (LPS)-dependent manner, leading to apoptosis which was triggered by the intracellular generation of reactive oxygen species. This induced neutrophil apoptosis was abolished by blocking FimH-mediated attachment, by inhibiting NADPH oxidase activation, or by neutralizing LPS. In contrast, CN1016, which did not adhere to or activate the respiratory burst of neutrophils, delayed the spontaneous apoptosis in an LPS-dependent manner. This delayed apoptosis could be mimicked by adding purified LPS and was also observed by using fimbriated bacteria in the presence of d-mannose. These results suggest that LPS is required for E. coli to exert both pro- and antiapoptotic effects on neutrophils and that the difference in LPS presentation (i.e., with or without fimbriae) determines the outcome. The present study showed that there is a fine-tuned balance between type 1 fimbria-induced and LPS-mediated delay of apoptosis in human neutrophils, in which altered fimbrial expression on uropathogenic E. coli determines the neutrophil survival and the subsequent inflammation during urinary tract infections.

Virulence factors analysis and antibiotic resistance of uropathogenic Escherichia coli isolated from patients in northeast of Iran

2020 ◽  
Author(s):  
Mahdis Ghavidel ◽  
Tahere Gholamhosseini-Moghadam ◽  
Kimiya Nourian ◽  
Kiarash Ghazvini
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Genes ◽  
High Rate ◽  
Resistance Pattern ◽  
Antibiotics Resistance ◽  
Disk Diffusion Test ◽  
E Coli ◽  
Genes Encoding ◽  
Tract Infections

Background and Objectives: Escherichia coli is known to be the pathogen commonly isolated from those infected with uri- nary tract infections (UTIs). The aim of this study was to investigate the presence of E. coli virulence genes and antibiotics’ resistance pattern among clinical isolates in the Northeast of Iran. Relationships between virulence genes and antimicrobial resistances were studied as well. Materials and Methods: Three hundred isolates of E. coli were isolated from patients with UTIs that referred to Ghaem and Imam Reza hospitals (Mashhad, Iran) during August 2016 to February 2017. A multiplex PCR was employed to amplify the genes encoding pyelonephritis associated pili (pap), S-family adhesions (sfa), type1fimbriae (fimH) and aerobactin (aer). Disk diffusion test was performed to test the susceptibility of isolates to β-lactams, aminoglycosides, cephalosporins, quino- lone, fluoroquinolones, carbapenems and trimethoprim-sulfamethoxazole. Results: The PCR results identified the fimH in 78.4%, aer in 70.5%, sfa in 13.6% and the pap in 8.2% of isolates. The rates of antibiotic resistance of the isolates were as follows: 64.7% resistant to cephalosporins, 34% to trimethoprim-sul- famethoxazole, 31% to fluoroquinolones, 15.3% to aminoglycosides, 13.3% to β-lactams, 7.8% to quinolones and 4.4% to carbapenems. Significant relationships existed between pap and aer, pap and sfa, aer and fluoroquinolones also pap and cephalosporins. Conclusion: fimH and aer were found in > 50% of isolates suggesting the importance of both genes in UPEC. The majority of isolates had fimH as adhesion factor for colonization. Determining antibiotic resistance patterns in specific geographical areas is necessary for appropriate treatment of urinary tract infection. The high rate of resistance to cephalosporins is most likely due to incorrect drug administration

scholarly journals Decreased Expression of Type 1 Fimbriae by apstMutant of Uropathogenic Escherichia coli Reduces Urinary Tract Infection

2012 ◽  
Vol 80 (8) ◽  
pp. 2802-2815 ◽  
Author(s):  
Sébastien Crépin ◽  
Sébastien Houle ◽  
Marie-Ève Charbonneau ◽  
Michaël Mourez ◽  
Josée Harel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Bacterial Virulence ◽  
Pho Regulon ◽  
Upec Strain ◽  
Content Type ◽  
Type 1 Fimbriae ◽  
Genes Encoding ◽  
Tract Infections

ABSTRACTThepstSCAB-phoUoperon encodes the phosphate-specific transport system (Pst). Loss of Pst constitutively activates the Pho regulon and decreases bacterial virulence. However, specific mechanisms underlying decreased bacterial virulence through inactivation of Pst are poorly understood. In uropathogenicEscherichia coli(UPEC) strain CFT073, inactivation ofpstdecreased urinary tract colonization in CBA/J mice. Thepstmutant was deficient in production of type 1 fimbriae and showed decreased expression of thefimAstructural gene which correlated with differential expression of thefimB,fimE,ipuA, andipbAgenes, encoding recombinases, mediating inversion of thefimpromoter. The role offimdownregulation in attenuation of thepstmutant was confirmed using afimphase-locked-on derivative, which demonstrated a significant gain in virulence. In addition, thepstmutant was less able to invade human bladder epithelial cells. Since type 1 fimbriae contribute to UPEC virulence by promoting colonization and invasion of bladder cells, the reduced bladder colonization by thepstmutant is predominantly attributed to downregulation of these fimbriae. Elucidation of mechanisms mediating the control of type 1 fimbriae through activation of the Pho regulon in UPEC may open new avenues for therapeutics or prophylactics against urinary tract infections.

scholarly journals Detection of auto-transporter Sat and Vat genes among Escherichia coli strains isolated from urinary tract infections

2019 ◽  
Vol 23 (10) ◽  
pp. 40 ◽  
Author(s):  
Wisal R. Yaseen AL- Hayali1 ◽  
Alaa Younis Mahdy2 ◽  
Muhammad Abdul Zaraq Ibrahim3
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Duplex Pcr ◽  
Macconkey Agar ◽  
Biochemical Tests ◽  
E Coli ◽  
Genes Encoding ◽  
Tract Infections ◽  
Pcr Techniques

This study was designed to detect the presence of genes encoding autotranspoter proteins in E. coli that causes UTI by using PCR techniques. Seventy two urine sample were collected from patients infected with UTI whom attended to Salah-AL-deen general hospital in Tikrit city, during three months period (September to November 2016). All samples were cultivated on Blood agar and MacConkey agar. The 47(65.2%) E. coli isolates were confirmed using standard biochemical tests for E. coli. The results indicate the frequencies of Sat gene was 27 strains(57.5%) while Vat gene was 12 strains (25.5%) while the Duplex PCR detected 8(17%) strains of E. coli contained two genes. With this method, we confirmed that autotransporter genes are pathospecifically distributed among the E. coli strains studied.   http://dx.doi.org/10.25130/tjps.23.2018.167

scholarly journals Suppression of Bladder Epithelial Cytokine Responses by Uropathogenic Escherichia coli

2005 ◽  
Vol 73 (7) ◽  
pp. 3999-4006 ◽  
Author(s):  
David A. Hunstad ◽  
Sheryl S. Justice ◽  
Chia S. Hung ◽  
Scott R. Lauer ◽  
Scott J. Hultgren
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Outer Membrane Proteins ◽  
Cytokine Signaling ◽  
E Coli ◽  
Cytokine Responses ◽  
Genes Encoding ◽  
Vitro Model ◽  
Tract Infections

ABSTRACT Urinary tract infections are most commonly caused by uropathogenic strains of Escherichia coli (UPEC), which invade superficial bladder epithelial cells via a type 1 pilus-dependent mechanism. Inside these epithelial cells, UPEC organisms multiply to high numbers to form intracellular bacterial communities, allowing them to avoid immune detection. Bladder epithelial cells produce interleukin-6 (IL-6) and IL-8 in response to laboratory strains of E. coli in vitro. We investigated the ability of UPEC to alter epithelial cytokine signaling by examining the in vitro responses of bladder epithelial cell lines to the cystitis strains UTI89 and NU14. The cystitis strains induced significantly less IL-6 than did the laboratory E. coli strain MG1655 from 5637 and T24 bladder epithelial cells. The cystitis strains also suppressed epithelial cytokine responses to exogenous lipopolysaccharide (LPS) and to laboratory E. coli. We found that insertional mutations in the rfa and rfb operons and in the surA gene all abolished the ability of UTI89 to suppress cytokine induction. The rfa and rfb operons encode LPS biosynthetic genes, while surA encodes a periplasmic cis-trans prolyl isomerase important in the biogenesis of outer membrane proteins. We conclude that, in this in vitro model system, cystitis strains of UPEC have genes encoding factors that suppress proinflammatory cytokine production by bladder epithelial cells.

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 Cytotoxic Necrotizing Factor Type 1 of Uropathogenic Escherichia coli Kills Cultured Human Uroepithelial 5637 Cells by an Apoptotic Mechanism

2000 ◽  
Vol 68 (10) ◽  
pp. 5869-5880 ◽  
Author(s):  
Melody Mills ◽  
Karen C. Meysick ◽  
Alison D. O'Brien
Keyword(s):  
Escherichia Coli ◽  
Cell Line ◽  
Cell Lines ◽  
Human Bladder ◽  
E Coli ◽  
Cytotoxic Necrotizing Factor ◽  
Bladder Cell ◽  
Factor Type ◽  
Tract Infections

ABSTRACT Pathogenic Escherichia coli associated with urinary tract infections (UTIs) in otherwise healthy individuals frequently produce cytotoxic necrotizing factor type 1 (CNF1), a member of the family of bacterial toxins that target the Rho family of small GTP-binding proteins. To gain insight into the function of CNF1 in the development of E. coli-mediated UTIs, we examined the effects of CNF1 intoxication on a panel of human cell lines derived from physiologically relevant sites (bladder, ureters, and kidneys). We identified one uroepithelial cell line that exhibited a distinctly different CNF1 intoxication phenotype from the prototypic one of multinucleation without cell death that is seen when HEp-2 or other epithelial cells are treated with CNF1. The 5637 bladder cell line detached from the growth surface within 72 h of CNF1 intoxication, a finding that suggested frank cytotoxicity. To determine the basis for the unexpected toxic effect of CNF1 on 5637 cells, we compared the degree of toxin binding, actin fiber formation, and Rho modification with those CNF1-induced events in HEp-2 cells. We found no apparent difference in the amount of CNF1 bound to 5637 cells and HEp-2 cells. Moreover, CNF1 modified Rho, in vivo and in vitro, in both cell types. In contrast, one of the classic responses to CNF1 in HEp-2 and other epithelial cell lines, the formation of actin stress fibers, was markedly absent in 5637 cells. Indeed, actin stress fiber induction by CNF1 did not occur in any of the other human bladder cell lines that we tested (J82, SV-HUC-1, or T24). Furthermore, the appearance of lamellipodia and filopodia in 5637 cells suggested that CNF1 activated the Cdc42 and Rac proteins. Finally, apoptosis was observed in CNF1-intoxicated 5637 cells. If our results with 5637 cells reflect the interaction of CNF1 with the transitional uroepithelium in the human bladder, then CNF1 may be involved in the exfoliative process that occurs in that organ after infection with uropathogenic E. coli.

scholarly journals Patterns of Variations in Escherichia coli Strains That Produce Cytolethal Distending Toxin

2004 ◽  
Vol 72 (2) ◽  
pp. 684-690 ◽  
Author(s):  
Carol L. Pickett ◽  
Robert B. Lee ◽  
Aysegul Eyigor ◽  
Ben Elitzur ◽  
Emily M. Fox ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Pcr Primers ◽  
Pcr Analysis ◽  
Cytolethal Distending Toxin ◽  
E Coli ◽  
Heat Stable ◽  
Genes Encoding ◽  
Factor Type

ABSTRACT A collection of 20 Escherichia coli strains that produce cytolethal distending toxin (CDT) were analyzed for their virulence-associated genes. All of these strains were serotyped, and multiplex PCR analysis was used to ascertain the presence of genes encoding other virulence factors, including Shiga toxin, intimin, enterohemolysin, cytotoxic necrotizing factor type 1 (CNF1) and CNF2, heat-stable toxin, and heat-labile toxin. These CDT-producing strains possessed various combinations of known virulence genes, some of which have not been noted before. Partial cdtB sequences were obtained from 10 of these strains, and their predicted CdtB sequences were compared to known E. coli CdtB sequences; some of the sequences were identical to known CdtB sequences, but two were not. PCR primers based on sequence differences between the known cdt sequences were tested for their ability to detect CDT producers and to determine CDT type. Correlations between the type of CDT produced, the presence of other virulence properties, and overall strain relatedness revealed that the CDT producers studied here can be divided into three general groups, with distinct differences in CDT type and in their complement of virulence-associated genes.

scholarly journals Adhesion of Escherichia Coli to Nanostructured Surfaces and the Role of Type 1 Fimbriae

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2247
Author(s):  
Pawel Kallas ◽  
Håvard J Haugen ◽  
Nikolaj Gadegaard ◽  
John Stormonth-Darling ◽  
Mats Hulander ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Virulence Factor ◽  
Wild Type ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
Tract Infections

Bacterial fimbriae are an important virulence factor mediating adhesion to both biotic and abiotic surfaces and facilitating biofilm formation. The expression of type 1 fimbriae of Escherichia coli is a key virulence factor for urinary tract infections and catheter-associated urinary tract infections, which represent the most common nosocomial infections. New strategies to reduce adhesion of bacteria to surfaces is therefore warranted. The aim of the present study was to investigate how surfaces with different nanotopography-influenced fimbriae-mediated adhesion. Surfaces with three different nanopattern surface coverages made in polycarbonate were fabricated by injection molding from electron beam lithography nanopatterned templates. The surfaces were constructed with features of approximately 40 nm width and 25 nm height with 100 nm, 250 nm, and 500 nm interspace distance, respectively. The role of fimbriae type 1-mediated adhesion was investigated using the E. coli wild type BW25113 and ΔfimA (with a knockout of major pilus protein FimA) and ΔfimH (with a knockout of minor protein FimH) mutants. For the surfaces with nanotopography, all strains adhered least to areas with the largest interpillar distance (500 nm). For the E. coli wild type, no difference in adhesion between surfaces without pillars and the largest interpillar distance was observed. For the deletion mutants, increased adhesion was observed for surfaces without pillars compared to surfaces with the largest interpillar distance. The presence of a fully functional type 1 fimbria decreased the bacterial adhesion to the nanopatterned surfaces in comparison to the mutants.

scholarly journals Prevalence of Quinolone Resistance of Extended-Spectrum β-Lactamase-Producing Escherichia coli with ST131-fimH30 in a City Hospital in Hyogo, Japan

2019 ◽  
Vol 20 (20) ◽  
pp. 5162 ◽  
Author(s):  
Masazumi Teramae ◽  
Kayo Osawa ◽  
Katsumi Shigemura ◽  
Koichi Kitagawa ◽  
Toshiro Shirakawa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Agents ◽  
City Hospital ◽  
Antimicrobial Susceptibility Test ◽  
E Coli ◽  
Specific Pcr ◽  
Extended Spectrum ◽  
Type 1 Pili ◽  
Genes Encoding

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates are known to tolerate superior quinolone antimicrobials compared with other antibacterial agents. Among the clones belonging to sequence type (ST) 131 by multilocus sequence typing, the involvement of the H30-Rx subclone has been reported worldwide with various fimH genes encoding type 1 pili. We investigated 83 isolates of ESBL-producing E. coli and performed antimicrobial susceptibility test, CH (fumC/fimH) ST131 by typing the specific PCR. Moreover, mutation analysis of genes involved in quinolone antibiotic resistance (gyrA and parC) and ESBL genotypes were determined. As a result, 54 of 83 isolates (65.1%) of CH40-30 clones corresponding to ST131-fimH30 were detected, and all were resistant to levofloxacin. Mutations associated with this resistance were common, and included S83L and D87N of gyrA and S80I and E84V of parC. Subclone analysis revealed a high proportion of fimH30-non-Rx (40 isolates, 74.1%). Each subclone was characterized by ESBL genotype, and the CTX-M-15 type was mainly seen for fimH30-Rx, with the CTX-M-14 type or CTX-M-27 type seen for fimH30-non-Rx. This study suggests that an increase in ESBL-producing quinolone-resistant E. coli in a city hospital in Hyogo, Japan, was caused by the spread of subclones belonging to fimH30-non-Rx of ST131.

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