scholarly journals Asymptomatic bacteriuria Escherichia coli strain 83972 carries mutations in the foc locus and is unable to express F1C fimbriae

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1799-1806 ◽  
Author(s):  
Viktoria Roos ◽  
Mark A. Schembri ◽  
Glen C. Ulett ◽  
Per Klemm
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Gene Cluster ◽  
Asymptomatic Bacteriuria ◽  
Human Kidney ◽  
Coli Strain ◽  
Gene Encoding ◽  
Symptomatic Urinary Tract Infection ◽  
E Coli ◽  
Colonization Factor

Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infection (UTI), very little is known about the mechanisms by which these strains colonize the urinary tract. Bacterial adhesion conferred by specific surface-associated adhesins is normally considered as a prerequisite for colonization of the urinary tract. The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. This study characterized the molecular status of one of the primary adhesion factors known to be associated with UTI, namely F1C fimbriae, encoded by the foc gene cluster. F1C fimbriae recognize receptors present in the human kidney and bladder. Expression of the foc genes was found to be up-regulated in human urine. It was also shown that although strain 83972 contains a seemingly intact foc gene cluster, F1C fimbriae are not expressed. Sequencing and genetic complementation revealed that the focD gene, encoding a component of the F1C transport and assembly system, was non-functional, explaining the inability of strain 83972 to express this adhesin. The data imply that E. coli 83972 has lost its ability to express this important colonization factor as a result of host-driven evolution. The ancestor of the strain seems to have been a pyelonephritis strain of phylogenetic group B2. Strain 83972 therefore represents an example of bacterial adaptation from pathogenicity to commensalism through virulence factor loss.

scholarly journals The Asymptomatic Bacteriuria Escherichia coli Strain 83972 Outcompetes Uropathogenic E. coli Strains in Human Urine

2006 ◽  
Vol 74 (1) ◽  
pp. 615-624 ◽  
Author(s):  
Viktoria Roos ◽  
Glen C. Ulett ◽  
Mark A. Schembri ◽  
Per Klemm
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Human Urine ◽  
Expression Profiles ◽  
Asymptomatic Bacteriuria ◽  
Gene Expression Profiles ◽  
Coli Strain ◽  
E Coli ◽  
Tract Infections

ABSTRACT Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infections (UTI), very little is known about the mechanisms by which these strains colonize the human urinary tract. The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. Deliberate colonization of UTI-susceptible individuals with E. coli 83972 has been used successfully as an alternative approach for the treatment of patients who are refractory to conventional therapy. Colonization with strain 83972 appears to prevent infection with UPEC strains in such patients despite the fact that this strain is unable to express the primary adhesins involved in UTI, viz. P and type 1 fimbriae. Here we investigated the growth characteristics of E. coli 83972 in human urine and show that it can outcompete a representative spectrum of UPEC strains for growth in urine. The unique ability of ABU E. coli 83972 to outcompete UPEC in urine was also demonstrated in a murine model of human UTI, confirming the selective advantage over UPEC in vivo. Comparison of global gene expression profiles of E. coli 83972 grown in lab medium and human urine revealed significant differences in expression levels in the two media; significant down-regulation of genes encoding virulence factors such as hemolysin, lipid A, and capsular polysaccharides was observed in cells grown in urine. Clearly, divergent abilities of ABU E. coli and UPEC to exploit human urine as a niche for persistence and survival suggest that these key differences may be exploited for preventative and/or therapeutic approaches.

scholarly journals The Globoseries Glycosphingolipid Sialosyl Galactosyl Globoside Is Found in Urinary Tract Tissues and Is a Preferred Binding Receptor In Vitro for Uropathogenic Escherichia coli Expressing pap-Encoded Adhesins

1998 ◽  
Vol 66 (8) ◽  
pp. 3856-3861 ◽  
Author(s):  
A. E. Stapleton ◽  
M. R. Stroud ◽  
S. I. Hakomori ◽  
W. E. Stamm
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Kidney Tissue ◽  
Human Kidney ◽  
Blood Group Antigens ◽  
E Coli ◽  
Vaginal Epithelial Cells ◽  
History Of ◽  
Tract Infections

ABSTRACT Women with a history of recurrent Escherichia coliurinary tract infections (UTIs) are significantly more likely to be nonsecretors of blood group antigens than are women without such a history, and vaginal epithelial cells (VEC) from women who are nonsecretors show enhanced adherence of uropathogenic E. coli isolates compared with cells from secretors. We previously extracted glycosphingolipids (GSLs) from native VEC and determined that nonsecretors (but not secretors) selectively express two extended globoseries GSLs, sialosyl galactosyl globoside (SGG) and disialosyl galactosyl globoside (DSGG), which specifically bound uropathogenicE. coli R45 expressing a P adhesin. In this study, we demonstrated, by purifying the compounds from this source, that SGG and DSGG are expressed in human kidney tissue. We also demonstrated that SGG and DSGG isolated from human kidneys bind uropathogenic E. coli isolates expressing each of the three classes ofpap-encoded adhesins, including cloned isolates expressing PapG from J96, PrsG from J96, and PapG from IA2, and the wild-type isolates IA2 and R45. We metabolically 35S labeled these five E. coli isolates and measured their relative binding affinities to serial dilutions of SGG and DSGG as well as to globotriaosylceramide (Gb3) and globotetraosylceramide (Gb4), two other globoseries GSLs present in urogenital tissues. Each of the five E. coli isolates bound to SGG with the highest apparent avidity compared with their binding to DSGG, Gb3, and Gb4, and each isolate had a unique pattern of GSL binding affinity. These studies further suggest that SGG likely plays an important role in the pathogenesis of UTI and that its presence may account for the increased binding of E. colito uroepithelial cells from nonsecretors and for the increased susceptibility of nonsecretors to recurrent UTI.

scholarly journals Whole-Genome Draft Sequences of Nine Asymptomatic Escherichia coli Bacteriuria Isolates from Diabetic Patients

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Christoph Stork ◽  
Beáta Kovács ◽  
Eva Trost ◽  
Tamás Kovács ◽  
György Schneider ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Asymptomatic Bacteriuria ◽  
Diabetic Patients ◽  
Whole Genome ◽  
Genome Sequences ◽  
Disease Response ◽  
Symptomatic Urinary Tract Infection ◽  
E Coli ◽  
Genome Draft

ABSTRACT Escherichia coli can colonize the urinary bladder without causing a disease response in the host. This asymptomatic bacteriuria (ABU) can protect against recurrent symptomatic urinary tract infection by virulent bacteria. Here, we report the whole-genome sequences of nine E. coli ABU isolates from diabetic patients.

scholarly journals Prevalence of a Gene Encoding Adhesin Involved in Diffuse Adherence among Escherichia Coli Isolates in Pigs with Postweaning Diarrhea or Edema Disease

2003 ◽  
Vol 15 (4) ◽  
pp. 378-381 ◽  
Author(s):  
Seung-Kwon Ha ◽  
Changsun Choi ◽  
Chanhee Chae
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Coli Strain ◽  
Isolation Rate ◽  
Gene Encoding ◽  
Edema Disease ◽  
E Coli ◽  
Heat Stable ◽  
Fimbrial Adhesins ◽  
Postweaning Diarrhea

A total of 604 Escherichia coli strains isolated from weaned pigs with diarrhea or edema disease on 653 swine farms were screened for the presence of the adhesin involved in diffuse adherence (AIDA) gene by polymerase chain reaction (PCR). Escherichia coli isolates that carried AIDA genes were also tested by PCR for the detection of 5 fimbriae (F4, F5, F6, F18, and F41), 3 heat-stable (STa, STb, and EAST1) and 1 heat-labile (LT) enterotoxin, and Shiga toxin 2e (Stx2e) genes. Forty-five (7.5%) of the 604 E. coli isolates carried the gene for AIDA. Of these 45 isolates, 5 (11.1%) carried EAST1 genes only, 1 (2.2%) carried genes for at least one of the fimbrial adhesins, 12 (26.7%) carried genes for at least one of the toxins, and 27 (60%) carried genes for at least one of the fimbrial adhesins and toxins. Fifty-one percent of strains that carried AIDA genes carried Stx2e genes, and 40% of strains that carried AIDA genes carried F18ab. The isolation rate of enterotoxigenic E. coli strain carrying genes for AIDA was 87%, and the isolation rate of Shiga toxin-producing E. coli strain carrying genes for AIDA was 49%. AIDA may represent an important virulence determinant in pigs with postweaning diarrhea or edema disease.

scholarly journals Gene Cluster for Assembly of Pilus Colonization Factor Antigen III of Enterotoxigenic Escherichia coli

2001 ◽  
Vol 69 (9) ◽  
pp. 5864-5873 ◽  
Author(s):  
Tooru Taniguchi ◽  
Yukihiro Akeda ◽  
Ayako Haba ◽  
Yoko Yasuda ◽  
Koichiro Yamamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleotide Sequence ◽  
Gene Cluster ◽  
Enterotoxigenic Escherichia Coli ◽  
Human Colon Carcinoma Cell ◽  
E Coli ◽  
Colonization Factor ◽  
Type Iv ◽  
K 12 ◽  
Factor Antigen

ABSTRACT The assembly of pilus colonization factor antigen III (CFA/III) of enterotoxigenic Escherichia coli (ETEC) requires the processing of CFA/III major pilin (CofA) by a prepilin peptidase (CofP), similar to other type IV pilus formation systems. CofA is produced initially as a 26.5-kDa preform pilin (prepilin) and then processed to a 20.5-kDa mature pilin by CofP which is predicted to be localized in the inner membrane. In the present experiment, we determined the nucleotide sequence of the whole region for CFA/III formation and identified a cluster of 14 genes, includingcofA and cofP. Several proteins encoded bycof genes were similar to previously described proteins, such as the toxin-coregulated pili of Vibrio cholerae and the bundle-forming pili of enteropathogenic E. coli. The G+C content of the cof gene cluster was 37%, which was significantly lower than the average for the E. coli genome (50%). The introduction of a recombinant plasmid containing thecof gene cluster into the E. coli K-12 strain conferred CFA/III biogenesis and the ability of adhesion to the human colon carcinoma cell line Caco-2. This is the first report of a complete nucleotide sequence of the type IV pili found in human ETEC, and our results provide a useful model for studying the molecular mechanism of CFA/III biogenesis and the role of CFA/III in ETEC infection.

scholarly journals TleA, a Tsh-Like Autotransporter Identified in a Human Enterotoxigenic Escherichia coli Strain

2015 ◽  
Vol 83 (5) ◽  
pp. 1893-1903 ◽  
Author(s):  
Daniela Gutiérrez ◽  
Mirka Pardo ◽  
David Montero ◽  
Angel Oñate ◽  
Mauricio J. Farfán ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Library ◽  
Coli Strain ◽  
Enterotoxigenic Escherichia Coli ◽  
Watery Diarrhea ◽  
Temperature Sensitive ◽  
Content Type ◽  
E Coli ◽  
Colonization Factor ◽  
Adhesion Level

EnterotoxigenicEscherichia coli(ETEC), a leading cause of acute diarrhea, colonizes the intestine by means of adhesins. However, 15 to 50% of clinical isolates are negative for known adhesins, making it difficult to identify antigens for broad-coverage vaccines. The ETEC strain 1766a, obtained from a child with watery diarrhea in Chile, harbors the colonization factor CS23 but is negative for other known adhesins. One clone, derived from an ETEC 1766a genomic library (clone G10), did not produce CS23 yet was capable of adhering to Caco-2 cells. The goal of this study was to identify the gene responsible for this capacity. Random transposon-based mutagenesis allowed the identification of a 4,110-bp gene that codes for a homologue of the temperature-sensitive hemagglutinin (Tsh) autotransporter described in avianE. colistrains (97% identity, 90% coverage) and that is called TleA (Tsh-like ETEC autotransporter) herein. An isogenic ETEC 1766a strain with atleAmutation showed an adhesion level similar to that of the wild-type strain, suggesting that the gene does not direct attachment to Caco-2 cells. However, expression oftleAconferred the capacity for adherence to nonadherentE. coliHB101. This effect coincided with the detection of TleA on the surface of nonpermeabilized bacteria, while, conversely, ETEC 1766a seems to secrete most of the produced autotransporter to the medium. On the other hand, TleA was capable of degrading bovine submaxillary mucin and leukocyte surface glycoproteins CD45 and P-selectin glycoprotein ligand 1 (PSGL-1). These results suggest that TleA promotes colonization of the intestinal epithelium and that it may modulate the host immune response.

Experimental colonization of the canine urinary tract with the asymptomatic bacteriuria Escherichia coli strain 83972

2011 ◽  
Vol 147 (1-2) ◽  
pp. 205-208 ◽  
Author(s):  
Mary F. Thompson ◽  
Makrina Totsika ◽  
Mark A. Schembri ◽  
Paul C. Mills ◽  
Erica J. Seton ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Asymptomatic Bacteriuria ◽  
Coli Strain

scholarly journals Fermentative Production of Thymidine by a Metabolically Engineered Escherichia coli Strain

2009 ◽  
Vol 75 (8) ◽  
pp. 2423-2432 ◽  
Author(s):  
Hyeon Cheol Lee ◽  
Jin Ha Kim ◽  
Jin Sook Kim ◽  
Wonhee Jang ◽  
Sang Yong Kim
Keyword(s):  
Escherichia Coli ◽  
De Novo ◽  
Excision Repair ◽  
Coli Strain ◽  
High Yield ◽  
Gene Encoding ◽  
E Coli ◽  
Fermentative Production ◽  
Batch Fermenter ◽  
Degradation Activity

ABSTRACT Thymidine is an important precursor in the production of various antiviral drugs, including azidothymidine for the treatment of AIDS. Since thymidine-containing nucleotides are synthesized only by the de novo pathway during DNA synthesis, it is not easy to produce a large amount of thymidine biologically. In order to develop a host strain to produce thymidine, thymidine phosphorylase, thymidine kinase, and uridine phosphorylase genes were deleted from an Escherichia coli BL21 strain to develop BLdtu. Since the genes coding for the enzymes related to the nucleotide salvage pathway were disrupted, BLdtu was unable to utilize thymidine or thymine, and thymidine degradation activity was completely abrogated. We additionally expressed T4 thymidylate synthase, T4 nucleotide diphosphate reductase, bacteriophage PBS2 TMP phosphohydrolase, E. coli dCTP deaminase, and E. coli uridine kinase in the BLdtu strain to develop a thymidine-producing strain (BLdtu24). BLdtu24 produced 649.3 mg liter−1 of thymidine in a 7-liter batch fermenter for 24 h, and neither thymine nor uridine was detected. However, the dUTP/dTTP ratio was increased in BLdtu24, which could lead to increased double-strand breakages and eventually to cell deaths during fermentation. To enhance thymidine production and to prevent cell deaths during fermentation, we disrupted a gene (encoding uracil-DNA N-glycosylase) involved in DNA excision repair to suppress the consumption of dTTP and developed BLdtug24. Compared with the thymidine production in BLdtu24, the thymidine production in BLdtug24 was increased by ∼1.2-fold (740.3 mg liter−1). Here, we show that a thymidine-producing strain with a relatively high yield can be developed using a metabolic engineering approach.

scholarly journals RegR Virulence Regulon of Rabbit-Specific Enteropathogenic Escherichia coli Strain E22

2013 ◽  
Vol 81 (4) ◽  
pp. 1078-1089 ◽  
Author(s):  
Yogitha N. Srikhanta ◽  
Dianna M. Hocking ◽  
Judyta Praszkier ◽  
Matthew J. Wakefield ◽  
Roy M. Robins-Browne ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Regulatory Protein ◽  
Bioinformatic Analysis ◽  
Coli Strain ◽  
Mobility Shift ◽  
Gene Encoding ◽  
Gene Target ◽  
Content Type ◽  
E Coli ◽  
Genes Encoding

ABSTRACTAraC-like regulators play a key role in the expression of virulence factors in enteric pathogens, such as enteropathogenicEscherichia coli(EPEC), enterotoxigenicE. coli, enteroaggregativeE. coli, andCitrobacter rodentium. Bioinformatic analysis of the genome of rabbit-specific EPEC (REPEC) strain E22 (O103:H2) revealed the presence of a gene encoding an AraC-like regulatory protein, RegR, which shares 71% identity to the global virulence regulator, RegA, ofC. rodentium. Microarray analysis demonstrated that RegR exerts 25- to 400-fold activation on transcription of several genes encoding putative virulence-associated factors, including a fimbrial operon (SEF14), a serine protease, and an autotransporter adhesin. These observations were confirmed by proteomic analysis of secreted and heat-extracted surface-associated proteins. The mechanism of RegR-mediated activation was investigated by using its most highly upregulated gene target,sefA. Transcriptional analyses and electrophoretic mobility shift assays showed that RegR activates the expression ofsefAby binding to a region upstream of thesefApromoter, thereby relieving gene silencing by the global regulatory protein H-NS. Moreover, RegR was found to contribute significantly to virulence in a rabbit infection experiment. Taken together, our findings indicate that RegR controls the expression of a series of accessory adhesins that significantly enhance the virulence of REPEC strain E22.

Sign in / Sign up

Export Citation Format

Share Document