Hyperimmune Bovine Colostral Anti-CS17 Antibodies Protect Against Enterotoxigenic Escherichia coli Diarrhea in a Randomized, Doubled-Blind, Placebo-Controlled Human Infection Model

AbstractBackgroundEnterotoxigenic Escherichia coli (ETEC) commonly cause diarrhea in children living in developing countries and in travelers to those regions. ETEC are characterized by colonization factors (CFs) that mediate intestinal adherence. We assessed if bovine colostral IgG (bIgG) antibodies against a CF, CS17, or antibodies against CsbD, the minor tip subunit of CS17, would protect subjects against diarrhea following challenge with a CS17-expressing ETEC strain.MethodsAdult subjects were randomized (1:1:1) to receive oral bIgG against CS17, CsbD, or placebo. Two days prior to challenge, subjects began dosing 3 times daily with the bIgG products (or placebo). On day 3, subjects ingested 5 × 109 cfu ETEC strain LSN03-016011/A in buffer. Subjects were assessed for diarrhea for 120 hours postchallenge.ResultsA total of 36 subjects began oral prophylaxis and 35 were challenged with ETEC. While 50.0% of the placebo recipients had watery diarrhea, none of the subjects receiving anti-CS17 had diarrhea (P = .01). In contrast, diarrhea rates between placebo and anti-CsbD recipients (41.7%) were comparable (P = 1.0).ConclusionsThis is the first study to demonstrate anti-CS17 antibodies provide significant protection against ETEC expressing CS17. More research is needed to better understand why anti-CsbD was not comparably efficacious.Clinical Trials Registration. NCT00524004

Download Full-text

The Controlled Human Infection Model for Enterotoxigenic Escherichia coli

10.1007/82_2021_242 ◽

2021 ◽

Author(s):

Chad K. Porter ◽

Kawsar R. Talaat ◽

Sandra D. Isidean ◽

Alwine Kardinaal ◽

Subhra Chakraborty ◽

...

Keyword(s):

Escherichia Coli ◽

Human Infection ◽

Enterotoxigenic Escherichia Coli ◽

Infection Model

Download Full-text

Newly Characterized Putative Colonization Factors of Human Enterotoxigenic Escherichia coli

Molecular Pathogenesis of Gastrointestinal Infections ◽

10.1007/978-1-4684-5982-1_11 ◽

1991 ◽

pp. 79-85 ◽

Cited By ~ 2

Author(s):

Moyra M. McConnell

Keyword(s):

Escherichia Coli ◽

Enterotoxigenic Escherichia Coli ◽

Colonization Factors

Download Full-text

CfaD-Dependent Expression of a Novel Extracytoplasmic Protein from Enterotoxigenic Escherichia coli

Journal of Bacteriology ◽

10.1128/jb.00131-07 ◽

2007 ◽

Vol 189 (14) ◽

pp. 5060-5067 ◽

Cited By ~ 33

Author(s):

M. Carolina Pilonieta ◽

Maria D. Bodero ◽

George P. Munson

Keyword(s):

Escherichia Coli ◽

Binding Sites ◽

Secretory Pathway ◽

Dnase I ◽

Enterotoxigenic Escherichia Coli ◽

Watery Diarrhea ◽

Dnase I Footprinting ◽

Virulence Regulator

ABSTRACT H10407 is a strain of enterotoxigenic Escherichia coli (ETEC) that utilizes CFA/I pili to adhere to surfaces of the small intestine, where it elaborates toxins that cause profuse watery diarrhea in humans. Expression of the CFA/I pilus is positively regulated at the level of transcription by CfaD, a member of the AraC/XylS family. DNase I footprinting revealed that the activator has two binding sites upstream of the pilus promoter cfaAp. One site extends from positions −23 to −56, and the other extends from positions −73 to −103 (numbering relative to the transcription start site of cfaAp). Additional CfaD binding sites were predicted within the genome of H10407 by computational analysis. Two of these sites lie upstream of a previously uncharacterized gene, cexE. In vitro DNase I footprinting confirmed that both sites are genuine binding sites, and cexEp::lacZ reporters demonstrated that CfaD is required for the expression of cexE in vivo. The amino terminus of CexE contains a secretory signal peptide that is removed during translocation across the cytoplasmic membrane through the general secretory pathway. These studies suggest that CexE may be a novel ETEC virulence factor because its expression is controlled by the virulence regulator CfaD, and its distribution is restricted to ETEC.

Download Full-text

Improvement of the Enterotoxigenic Escherichia coli Infection Model for Post-Weaning Diarrhea by Controlling for Bacterial Adhesion, Pig Breed and MUC4 Genotype

Veterinary Sciences ◽

10.3390/vetsci7030106 ◽

2020 ◽

Vol 7 (3) ◽

pp. 106

Author(s):

Hiroki Matsumoto ◽

Masashi Miyagawa ◽

Sayaka Takahashi ◽

Ryouichi Shima ◽

Takayuki Oosumi

Keyword(s):

Escherichia Coli ◽

Experimental Infection ◽

Antibacterial Agents ◽

Experimental Models ◽

Enterotoxigenic Escherichia Coli ◽

Infection Model ◽

Swine Industry ◽

Pig Breeds ◽

Adhesion Ability ◽

Escherichia Coli Infection

Enterotoxigenic Escherichia coli (ETEC) is a major cause of post-weaning diarrhea (PWD) in pigs and causes significant damage to the swine industry worldwide. In recent years, there has been increased regulation against the use of antibacterial agents in swine due to their health risks. Utilizing experimental models that consistently recapitulate PWD is important for the development of non-antibacterial agents against PWD in pigs. In this study, we established a highly reproducible PWD infection model by examining differences in adhesion of ETEC to the intestinal tissue as well as the association between MUC4 polymorphisms and sensitivity to PWD. Post-weaning diarrhea differences between pig breeds were also examined. The adhesion to enterocytes varied from 104.0 to 106.4 CFU/mL even among the F4 ETEC strains. Experimental infection revealed that PWD can be induced in all MUC4 genotypes after infection with 1010 CFU/pig of highly adherent ETEC, although there were variable sensitivities between the genotypes. Lowly adherent ETEC did not cause PWD as efficiently as did highly adherent ETEC. The incidence of PWD was confirmed for all pigs with the ETEC-susceptible MUC4 genotypes in all of the breeds. These results indicate that high-precision and reproducible experimental infection is possible regardless of pig breeds by controlling factors on the pig-end (MUC4 genotype) and the bacterial-end (adhesion ability).

Download Full-text

Over-expression of major colonization factors of enterotoxigenic Escherichia coli, alone or together, on non-toxigenic E. coli bacteria

Vaccine ◽

10.1016/j.vaccine.2010.08.047 ◽

2010 ◽

Vol 28 (43) ◽

pp. 6977-6984 ◽

Cited By ~ 19

Author(s):

Joshua Tobias ◽

Jan Holmgren ◽

Maria Hellman ◽

Erik Nygren ◽

Michael Lebens ◽

...

Keyword(s):

Escherichia Coli ◽

Enterotoxigenic Escherichia Coli ◽

Over Expression ◽

E Coli ◽

Colonization Factors

Download Full-text

Enumeration of Gut-Homing β7-Positive, Pathogen-Specific Antibody-Secreting Cells in Whole Blood from Enterotoxigenic Escherichia coli- and Vibrio cholerae-Infected Patients, Determined Using an Enzyme-Linked Immunosorbent Spot Assay Technique

Clinical and Vaccine Immunology ◽

10.1128/cvi.00526-15 ◽

2015 ◽

Vol 23 (1) ◽

pp. 27-36 ◽

Cited By ~ 8

Author(s):

Taufiqur Rahman Bhuiyan ◽

Mohammad Rubel Hoq ◽

Naoshin Sharmin Nishat ◽

Deena Al Mahbuba ◽

Rasheduzzaman Rashu ◽

...

Keyword(s):

Escherichia Coli ◽

Immune Responses ◽

Vibrio Cholerae ◽

Elispot Assay ◽

Enterotoxigenic Escherichia Coli ◽

Watery Diarrhea ◽

Content Type ◽

A Cell ◽

Mucosal Immune Responses ◽

Antibody Secreting Cells

ABSTRACTVibrio choleraeand enterotoxigenicEscherichia coli(ETEC) are noninvasive mucosal pathogens that cause acute watery diarrhea in people in developing countries. Direct assessment of the mucosal immune responses to these pathogens is problematic. Surrogate markers of local mucosal responses in blood are increasingly being studied to determine the mucosal immune responses after infection. However, the volume of blood available in children and infants has limited this approach. We assessed whether an approach that first isolates β7-positive cells from a small volume of blood would allow measurement of the antigen-specific immune responses in patients with cholera and ETEC infection. β7 is a cell surface marker associated with mucosal homing. We isolated β7-expressing cells from blood on days 2, 7, and 30 and used an enzyme-linked immunosorbent spot (ELISPOT) assay to assess the gut-homing antibody-secreting cells (ASCs) specific to pathogen antigens. Patients with ETEC diarrhea showed a significant increase in toxin-specific gut-homing ASCs at day 7 compared to the levels at days 2 and 30 after onset of illness and to the levels in healthy controls. Similar elevations of responses to the ETEC colonization factors (CFs) CS6 and CFA/I were observed in patients infected with CS6- and CFA/I-positive ETEC strains. Antigen-specific gut-homing ASCs to the B subunit of cholera toxin and cholera-specific lipopolysaccharides (LPS) were also observed on day 7 after the onset of cholera using this approach. This study demonstrates that a simple ELISPOT assay can be used to study the mucosal immunity to specific antigens using a cell-sorting protocol to isolate mucosal homing cells, facilitating measurement of mucosal responses in children following infection or vaccination.

Download Full-text

A Tripartite Fusion, FaeG-FedF-LT192A2:B, of Enterotoxigenic Escherichia coli (ETEC) Elicits Antibodies That Neutralize Cholera Toxin, Inhibit Adherence of K88 (F4) and F18 Fimbriae, and Protect Pigs against K88ac/Heat-Labile Toxin Infection

Clinical and Vaccine Immunology ◽

10.1128/cvi.05120-11 ◽

2011 ◽

Vol 18 (10) ◽

pp. 1593-1599 ◽

Cited By ~ 25

Author(s):

Xiaosai Ruan ◽

Mei Liu ◽

Thomas A. Casey ◽

Weiping Zhang

Keyword(s):

Escherichia Coli ◽

Cholera Toxin ◽

Enterotoxigenic Escherichia Coli ◽

Content Type ◽

Etec Strain ◽

Severe Diarrhea ◽

Heat Stable ◽

Heat Labile ◽

Young Pigs ◽

Gnotobiotic Piglet

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) strains expressing K88 (F4) or F18 fimbriae and heat-labile (LT) and/or heat-stable (ST) toxins are the major cause of diarrhea in young pigs. Effective vaccines inducing antiadhesin (anti-K88 and anti-F18) and antitoxin (anti-LT and anti-ST) immunity would provide broad protection to young pigs against ETEC. In this study, we genetically fused nucleotides coding for peptides from K88ac major subunit FaeG, F18 minor subunit FedF, and LT toxoid (LT192) A2 and B subunits for a tripartite adhesin-adhesin-toxoid fusion (FaeG-FedF-LT192A2:B). This fusion was used for immunizations in mice and pigs to assess the induction of antiadhesin and antitoxin antibodies. In addition, protection by the elicited antiadhesin and antitoxin antibodies against a porcine ETEC strain was evaluated in a gnotobiotic piglet challenge model. The data showed that this FaeG-FedF-LT192A2:B fusion elicited anti-K88, anti-F18, and anti-LT antibodies in immunized mice and pigs. In addition, the anti-porcine antibodies elicited neutralized cholera toxin and inhibited adherence against both K88 and F18 fimbriae. Moreover, immunized piglets were protected when challenged with ETEC strain 30302 (K88ac/LT/STb) and did not develop clinical disease. In contrast, all control nonvaccinated piglets developed severe diarrhea and dehydration after being challenged with the same ETEC strain. This study clearly demonstrated that this FaeG-FedF-LT192A2:B fusion antigen elicited antibodies that neutralized LT toxin and inhibited the adherence of K88 and F18 fimbrialE. colistrains and that this fusion could serve as an antigen for vaccines against porcine ETEC diarrhea. In addition, the adhesin-toxoid fusion approach used in this study may provide important information for developing effective vaccines against human ETEC diarrhea.

Download Full-text

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

Infection and Immunity ◽

10.1128/iai.02976-14 ◽

2015 ◽

Vol 83 (5) ◽

pp. 1893-1903 ◽

Cited By ~ 8

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.

Download Full-text

In Vitro Evaluation of Dietary Fiber Anti-Infectious Properties against Food-Borne Enterotoxigenic Escherichia coli

Nutrients ◽

10.3390/nu13093188 ◽

2021 ◽

Vol 13 (9) ◽

pp. 3188

Author(s):

Thomas Sauvaitre ◽

Claude Durif ◽

Adeline Sivignon ◽

Sandrine Chalancon ◽

Tom Van de Wiele ◽

...

Keyword(s):

Escherichia Coli ◽

Culture Media ◽

Toxin Production ◽

Enterotoxigenic Escherichia Coli ◽

In Vitro Assays ◽

Dietary Fibers ◽

Mucus Cell ◽

Etec Strain ◽

Beneficial Effects

Dietary fibers have well-known beneficial effects on human health, but their anti-infectious properties against human enteric pathogens have been poorly investigated. Enterotoxigenic Escherichia coli (ETEC) is the main agent of travelers’ diarrhea, against which targeted preventive strategies are currently lacking. ETEC pathogenesis relies on multiple virulence factors allowing interactions with the intestinal mucosal layer and toxins triggering the onset of diarrheal symptoms. Here, we used complementary in vitro assays to study the antagonistic properties of eight fiber-containing products from cereals, legumes or microbes against the prototypical human ETEC strain H10407. Inhibitory effects of these products on the pathogen were tested through growth, toxin production and mucus/cell adhesion inhibition assays. None of the tested compounds inhibited ETEC strain H10407 growth, while lentil extract was able to decrease heat labile toxin (LT) concentration in culture media. Lentil extract and specific yeast cell walls also interfered with ETEC strain H10407 adhesion to mucin beads and human intestinal cells. These results constitute a first step in the use of dietary fibers as a nutritional strategy to prevent ETEC infection. Further work will be dedicated to the study of fiber/ETEC interactions within a complex gut microbial background.

Download Full-text