Colonization factors associated with enterotoxigenic Escherichia coli isolated in Thailand.

ABSTRACT The prevalence of toxin types and colonization factors (CFs) of enterotoxigenic Escherichia coli (ETEC) was prospectively studied with fresh samples ( n = 4,662) obtained from a 2% routine surveillance of diarrheal stool samples over 2 years, from September 1996 to August 1998. Stool samples were tested by enzyme-linked immunoassay techniques and with specific monoclonal antibodies for the toxins and CFs. The prevalence of ETEC was 14% ( n = 662), with over 70% of the strains isolated from children 0 to 5 years of age, of whom 93% were in the 0- to 3-year-old age range. Of the total ETEC isolates, 49.4% were positive for the heat-stable toxin (ST), 25.4% were positive for the heat-labile toxin (LT) only, and 25.2% were positive for both LT and ST. The rate of ETEC isolation peaked in the hot summer months of May to September and decreased in winter. About 56% of the samples were positive for 1 or more of the 12 CFs that were screened for. The coli surface antigens CS4, CS5, and/or CS6 of the colonization factor antigen (CFA)/IV complex were most prevalent (incidence, 31%), followed by CFA/I (23.5%) and coli surface antigens CS1, CS2, and CS3 of CFA/II (21%). In addition, other CFs detected in decreasing order were CS7 (8%), CS14 (PCFO166) (7%), CS12 (PCFO159) (4%), CS17 (3%), and CS8 (CFA/III) (2.7%). The ST- or LT- and ST-positive ETEC isolates expressed the CFs known to be the most prevalent (i.e., CFA/I, CFA/II, and CFA/IV), while the strains positive for LT only did not. Among children who were infected with ETEC as the single pathogen, a trend of relatively more severe disease in children infected with ST-positive ( P < 0.001) or LT- and ST-positive ( P < 0.001) ETEC isolates compared to the severity of the disease in children infected with LT only-positive ETEC isolates was seen. This study supports the fact that ETEC is still a major cause of childhood diarrhea in Bangladesh, especially in children up to 3 years of age, and that measures to prevent such infections are needed in developing countries.

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Enterotoxigenic Escherichia coli Isolated from Foods in São Paulo, Brazil

Journal of Food Protection ◽

10.4315/0362-028x-50.10.832 ◽

1987 ◽

Vol 50 (10) ◽

pp. 832-834 ◽

Cited By ~ 3

Author(s):

BERNADETTE D. G. M. FRANCO ◽

BEATRIZ E. C. GUTH ◽

LUIZ R. TRABULSI

Keyword(s):

Escherichia Coli ◽

Food Samples ◽

Sao Paulo ◽

Enterotoxigenic Escherichia Coli ◽

São Paulo ◽

E Coli ◽

Colonization Factors ◽

The City

Incidence of enterotoxigenic Escherichia coli (ETEC) in foods usually consumed in the city of Sao Paulo, Brazil was determined. Raw and cooked foods of animal and vegetable origin were investigated. Enterotoxigenic strains were found in approximately 3.5% of food samples contaminated with E. coli. There was a great predominance of ETEC strains producing only LT enterotoxin. None of the isolated strains produced LT and ST simultaneously. Several serotypes were involved, and none of them was positive for colonization factors CFA-I and CFA-II. One ETEC showed resistance to some antibiotics but most were sensitive to the ones tested.

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The Major Subunit, CfaB, of Colonization Factor Antigen I from Enterotoxigenic Escherichia coli Is a Glycosphingolipid Binding Protein

Infection and Immunity ◽

10.1128/iai.02006-05 ◽

2006 ◽

Vol 74 (6) ◽

pp. 3488-3497 ◽

Cited By ~ 55

Author(s):

Lena Jansson ◽

Joshua Tobias ◽

Michael Lebens ◽

Ann-Mari Svennerholm ◽

Susann Teneberg

Keyword(s):

Escherichia Coli ◽

Pathogenic Bacteria ◽

Binding Capacity ◽

Enterotoxigenic Escherichia Coli ◽

E Coli ◽

Colonization Factor ◽

Mucosal Surfaces ◽

Colonization Factors ◽

Bacteria Adhesion ◽

Colonization Factor Antigen I

ABSTRACT Bacterial adherence to mucosal surfaces is an important virulence trait of pathogenic bacteria. Adhesion of enterotoxigenic Escherichia coli (ETEC) to the intestine is mediated by a number of antigenically distinct colonization factors (CFs). One of the most common CFs is CFA/I. This has a fimbrial structure composed of a major repeating subunit, CfaB, and a single tip subunit, CfaE. The potential carbohydrate recognition by CFA/I was investigated by binding CFA/I-fimbriated bacteria and purified CFA/I fimbriae to a large number of variant glycosphingolipids separated on thin-layer chromatograms. For both fimbriated bacteria and purified fimbriae, specific interactions could be identified with a number of nonacid glycosphingolipids. These included glucosylceramide, lactosylceramide with phytosphingosine and/or hydroxy fatty acids, neolactotetraosylceramide, gangliotriaosylceramide, gangliotetraosylceramide, the H5 type 2 pentaglycosylceramide, the Lea-5 glycosphingolipid, the Lex-5 glycosphingolipid, and the Ley-6 glycosphingolipid. These glycosphingolipids were also recognized by recombinant E. coli expressing CFA/I in the absence of tip protein CfaE, as well as by purified fimbriae from the same strain. This demonstrates that the glycosphingolipid-binding capacity of CFA/I resides in the major CfaB subunit.

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Expression of enterotoxigenic Escherichia coli colonization factors in Vibrio cholerae

Vaccine ◽

10.1016/j.vaccine.2006.02.052 ◽

2006 ◽

Vol 24 (20) ◽

pp. 4354-4368 ◽

Cited By ~ 20

Author(s):

Didier Favre ◽

Stefan Lüdi ◽

Michael Stoffel ◽

Joachim Frey ◽

Michael P. Horn ◽

...

Keyword(s):

Escherichia Coli ◽

Vibrio Cholerae ◽

Enterotoxigenic Escherichia Coli ◽

Colonization Factors

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Allele Variants of Enterotoxigenic Escherichia coli Heat-Labile Toxin Are Globally Transmitted and Associated with Colonization Factors

Journal of Bacteriology ◽

10.1128/jb.02050-14 ◽

2014 ◽

Vol 197 (2) ◽

pp. 392-403 ◽

Cited By ~ 14

Author(s):

Enrique Joffré ◽

Astrid von Mentzer ◽

Moataz Abd El Ghany ◽

Numan Oezguen ◽

Tor Savidge ◽

...

Keyword(s):

Escherichia Coli ◽

Amino Acid ◽

Fluid Secretion ◽

Toxin Production ◽

Amino Acid Sequences ◽

Enterotoxigenic Escherichia Coli ◽

Content Type ◽

Heat Labile ◽

Virulence Potential ◽

Colonization Factors

EnterotoxigenicEscherichia coli(ETEC) is a significant cause of morbidity and mortality in the developing world. ETEC-mediated diarrhea is orchestrated by heat-labile toxin (LT) and heat-stable toxins (STp and STh), acting in concert with a repertoire of more than 25 colonization factors (CFs). LT, the major virulence factor, induces fluid secretion after delivery of a monomeric ADP-ribosylase (LTA) and its pentameric carrier B subunit (LTB). A study of ETEC isolates from humans in Brazil reported the existence of natural LT variants. In the present study, analysis of predicted amino acid sequences showed that the LT amino acid polymorphisms are associated with a geographically and temporally diverse set of 192 clinical ETEC strains and identified 12 novel LT variants. Twenty distinct LT amino acid variants were observed in the globally distributed strains, and phylogenetic analysis showed these to be associated with different CF profiles. Notably, the most prevalent LT1 allele variants were correlated with major ETEC lineages expressing CS1 + CS3 or CS2 + CS3, and the most prevalent LT2 allele variants were correlated with major ETEC lineages expressing CS5 + CS6 or CFA/I. LTB allele variants generally exhibited more-stringent amino acid sequence conservation (2 substitutions identified) than LTA allele variants (22 substitutions identified). The functional impact of LT1 and LT2 polymorphisms on virulence was investigated by measuring total-toxin production, secretion, and stability using GM1–enzyme-linked immunosorbent assays (GM1-ELISA) andin silicoprotein modeling. Our data show that LT2 strains produce 5-fold more toxin than LT1 strains (P< 0.001), which may suggest greater virulence potential for this genetic variant. Our data suggest that functionally distinct LT-CF variants with increased fitness have persisted during the evolution of ETEC and have spread globally.

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Infection with colonization factor antigen I-expressing enterotoxigenic Escherichia coli boosts antibody responses against heterologous colonization factors in primed subjects

Epidemiology and Infection ◽

10.1017/s0950268897008200 ◽

1997 ◽

Vol 119 (3) ◽

pp. 391-393 ◽

Cited By ~ 11

Author(s):

A. RUDIN ◽

G. WIKLUND ◽

C. WENNERÅS ◽

F. QADRI

Keyword(s):

Escherichia Coli ◽

Antibody Responses ◽

Enterotoxigenic Escherichia Coli ◽

Enzyme Linked Immunosorbent Assay ◽

Symptomatic Infection ◽

Colonization Factor ◽

Serum Iga ◽

Iga Antibody ◽

Colonization Factors ◽

Colonization Factor Antigen I

Enterotoxigenic Escherichia coli (ETEC) adhere to the intestinal mucosa by a number of fimbrial colonization factors (CFs) that have been claimed to induce only type-specific immunity. However, adult Bangladeshi patients infected with CFA/I-expressing bacteria, developed significant plasma IgA antibody responses, as determined by enzyme-linked immunosorbent assay, not only against the homologous fimbriae but also against several heterologous CFs, i.e. CS1, CS2, CS4 and PCFO166 fimbriae. In contrast, North American volunteers, who had probably not been infected by ETEC previously, responded with serum IgA against CFA/I fimbriae but not against any other CFs after symptomatic infection with CFA/I-expressing ETEC. Thus, infection with CFA/I-expressing bacteria may boost immune responses against CFs with a related amino acid sequence in previously primed subjects.

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Generation and Characterization of a Live Attenuated Enterotoxigenic Escherichia coli Combination Vaccine Expressing Six Colonization Factors and Heat-Labile Toxin Subunit B

Clinical and Vaccine Immunology ◽

10.1128/cvi.05345-11 ◽

2011 ◽

Vol 18 (12) ◽

pp. 2128-2135 ◽

Cited By ~ 27

Author(s):

Arthur K. Turner ◽

Jonathan C. Stephens ◽

Juliet C. Beavis ◽

Judith Greenwood ◽

Cornelia Gewert ◽

...

Keyword(s):

Escherichia Coli ◽

Enterotoxigenic Escherichia Coli ◽

Gene Encoding ◽

Double Blind ◽

Content Type ◽

Double Blind Placebo ◽

Heat Stable ◽

Heat Labile ◽

Colonization Factors ◽

Viable Approach

ABSTRACTLive attenuated oral enterotoxigenicEscherichia coli(ETEC) vaccines have been demonstrated to be safe and immunogenic in human volunteers and to provide a viable approach to provide protection against this important pathogen. This report describes the construction of new ETEC vaccine candidate strains from recent clinical isolates and their characterization. All known genes for ETEC toxins were removed, and attenuating deletion mutations were made in thearoC,ompC, andompFchromosomal genes. An isolate expressing coli surface antigen 2 (CS2), CS3, heat-labile toxin (LT), heat-stable toxin (ST), and enteroaggregativeEscherichia coliheat-stable toxin 1 (EAST1) was attenuated to generate ACAM2007. The subsequent insertion of the operon encoding CS1 created ACAM2017, and this was further modified by the addition of an expression cassette containing theeltBgene, encoding a pentamer of B subunits of LT (LTB), to generate ACAM2027. Another isolate expressing CS5, CS6, LT, ST, and EAST1 was attenuated to generate ACAM2006, from which a lysogenic prophage was deleted to create ACAM2012 and an LTB gene was introduced to form ACAM2022. Finally, a previously described vaccine strain, ACAM2010, had theeltBgene incorporated to generate ACAM2025. All recombinant genes were incorporated into the chromosomal sites of the attenuating mutations to ensure maximal genetic stability. The expression of the recombinant antigens and the changes in plasmids accompanying the deletion of toxin genes are described. Strains ACAM2025, ACAM2022, and ACAM2027 have been combined to create the ETEC vaccine formulation ACE527, which has recently successfully completed a randomized, double-blind, placebo-controlled phase I trial and is currently undergoing a randomized, double-blind placebo-controlled phase II challenge trial, both in healthy adult volunteers.

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