scholarly journals Heat-Stable Enterotoxins of Enterotoxigenic Escherichia coli and Their Impact on Host Immunity

Toxins ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 24 ◽  
Author(s):  
Haixiu Wang ◽  
Zifu Zhong ◽  
Yu Luo ◽  
Eric Cox ◽  
Bert Devriendt
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Enterotoxigenic Escherichia Coli ◽  
Farm Animals ◽  
Future Research ◽  
Intestinal Epithelial ◽  
Heat Stable ◽  
Intestinal Immune System ◽  
Global Threat ◽  
The Impact

Enterotoxigenic Escherichia coli (ETEC) are an important diarrhea-causing pathogen and are regarded as a global threat for humans and farm animals. ETEC possess several virulence factors to infect its host, including colonization factors and enterotoxins. Production of heat-stable enterotoxins (STs) by most ETEC plays an essential role in triggering diarrhea and ETEC pathogenesis. In this review, we summarize the heat-stable enterotoxins of ETEC strains from different species as well as the molecular mechanisms used by these heat-stable enterotoxins to trigger diarrhea. As recently described, intestinal epithelial cells are important modulators of the intestinal immune system. Thus, we also discuss the impact of the heat-stable enterotoxins on this role of the intestinal epithelium and how these enterotoxins might affect intestinal immune cells. Finally, the latest developments in vaccination strategies to protect against infections with ST secreting ETEC strains are discussed. This review might inform and guide future research on heat-stable enterotoxins to further unravel their molecular pathogenesis, as well as to accelerate vaccine design.

Use of a Multiplex PCR System for the Simultaneous Detection of Heat Labile Toxin I and Heat Stable Toxin II Genes of Enterotoxigenic Escherichia coli in Skim Milk and Porcine Stool

1998 ◽  
Vol 61 (2) ◽  
pp. 141-145 ◽  
Author(s):  
HAU-YANG TSEN ◽  
LIANG-ZHAO JIAN ◽  
WAN-RONG CHI
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Simultaneous Detection ◽  
Skim Milk ◽  
Pcr Primers ◽  
Enterotoxigenic Escherichia Coli ◽  
Farm Animals ◽  
Target Cells ◽  
Heat Stable ◽  
Heat Labile

Enterotoxigenic Escherichia coli (ETEC) strains which produce heat labile and/or heat stable toxins (LT and ST) may cause diarrhea in humans and farm animals. Using PCR primers specific for the LT I and ST II genes, a multiplex PCR system which allows detection of LT I- and ST II-producing ETEC strains was developed. When skim milk was used for a PCR assay, it was found that if target cells in the sample were precultured in MacConkey broth for 8 h prior to PCR as few as 100 cells per ml of the sample could be detected. Without the preculture step, 104 CFU of target cells per 0.2 g of porcine stool specimen were required to generate visible PCR products. The multiplex PCR System can be used for rapid testing of fecal specimens, food and possibly environmental samples for the presence of ETEC strains.

scholarly journals Osteopontin-Enriched Algae Modulates the Gut Microbiota Composition in Weaning Piglets Infected with Enterotoxigenic Escherichia Coli (P06-069-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Mei Wang ◽  
Brooke Smith ◽  
Brock Adams ◽  
Miller Tran ◽  
Ryan Dilger ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gut Microbiota ◽  
Alpha Diversity ◽  
Enterotoxigenic Escherichia Coli ◽  
Farm Animals ◽  
Future Research ◽  
Rrna Gene ◽  
Microbiota Composition ◽  
Wild Type ◽  
Gut Microbiota Composition

Abstract Objectives Enterotoxigenic Escherichia coli (ETEC) are an important cause of diarrhea in human infants and young farm animals. Osteopontin (OPN), a glycoprotein present in high concentration in human milk, has immunomodulatory functions, which could indirectly impact the microbiota. Furthermore, a previous study has shown fecal microbiota composition differs between wild-type and OPN knockout mice. Herein, the effects of OPN-enriched algae on the gut microbiota composition and volatile fatty acid (VFA) concentrations of ETEC-infected piglets were assessed. Methods Naturally-farrowed piglets were sow-reared for 21 days and then randomized to two weaning diets: WT (formula + 1% wild-type algae) or OPN (formula + 1% OPN-enriched algae). On postnatal day (PND) 31, all piglets were infected orally with a live culture of ETEC (1010 colony-forming unit/3 mL dose) daily for three consecutive days. On PND 41, ascending colon (AC) contents were collected. Gut microbiota was assessed by sequencing V3-V4 regions of 16S rRNA gene and VFAs were determined by gas chromatography. Alpha-diversity and VFAs were analyzed using PROC MIXED procedure of SAS. Beta-diversity was evaluated by permutational multivariate analysis of variance (PERMANOVA) and differential abundance analysis on the bacterial genera was performed using DESeq2 package of R. Results Shannon indices were lower in the AC contents of OPN piglets compared to WT piglets. The overall colonic microbiota of OPN piglets differed from that of WT piglets (PERMANOVA P = 0.015). At genus level, OPN-enriched algae increased the abundance of Streptococcus, decreased the abundances of Sutterella, Candidatus Soleaferrea, dga-11 gut group, Rikenellaceae RC9 gut group, Ruminococcaceae UCG-010, unculturedRuminococcaceae, Prevotella 2 and 7 compared to piglets consuming wild-type algae (P < 0. 05). OPN piglets also had higher (P < 0.05) concentrations of acetate, propionate, butyrate and valerate compared to WT. Conclusions In ETEC infected piglets, 1% OPN-enriched algae decreased alpha-diversity and modulated the microbiota composition and VFA profiles compared to 1% WT algae. Other studies have shown that OPN inhibits biofilm formation in vitro, but future research is needed to assess in vivo microbiome-modulation mechanisms. Funding Sources Triton Algae Innovations.

scholarly journals Pig vaccination strategies based on enterotoxigenic Escherichia coli toxins

2021 ◽  
Author(s):  
J. Daniel Dubreuil
Keyword(s):  
Escherichia Coli ◽  
Initial Step ◽  
Enterotoxigenic Escherichia Coli ◽  
Farm Animals ◽  
Heat Stable ◽  
Immunization Strategies ◽  
Protection Efficacy ◽  
Weaning Piglets ◽  
New Generation ◽  
Pathogenic Process

AbstractEnterotoxigenic Escherichia coli (ETEC) are responsible for diarrhea in humans as well as in farm animals. ETEC infections in newborn, suckling, and especially in post-weaning piglets are associated with reduced growth rate, morbidity, and mortality. ETEC express virulence factors as adhesin and enterotoxins that play a central role in the pathogenic process. Adhesins associated with pigs are of diverse type being either fimbrial or non-fimbrial. Enterotoxins belong to two groups: heat-labile (LT) and heat-stable (ST). Heterogeneity of ETEC strains encompass expression of various fimbriae (F4, F5, F6, F18, and F41) and enterotoxins (LT, STa, STb, and EAST1). In the late years, attempts to immunize animals against neonatal and post-weaning diarrhea were focused on the development of anti-adhesin strategies as this is the initial step of ETEC pathogenesis. Although those vaccines demonstrated some protection against ETEC infections, as enterotoxins are pivotal to the virulence of ETEC, a new generation of vaccinal molecules, which include adhesin and one or more enterotoxins, were recently tested. Some of these newly developed chimeric fusion proteins are intended to control as well human diarrhea as enterotoxins are more or less common with the ones found in pigs. As these could not be tested in the natural host (human), either a mouse or pig model was substituted to evaluate the protection efficacy. For the advancement of pig vaccine, mice were sometimes used for preliminary testing. This review summarizes advances in the anti-enterotoxin immunization strategies considered in the last 10 years.

scholarly journals Elevated Extracellular cGMP Produced after Exposure to Enterotoxigenic Escherichia coli Heat-Stable Toxin Induces Epithelial IL-33 Release and Alters Intestinal Immunity

2021 ◽  
Vol 89 (4) ◽  
Author(s):  
Natalya I. Motyka ◽  
Sydney R. Stewart ◽  
Ian E. Hollifield ◽  
Thomas R. Kyllo ◽  
Joshua A. Mansfield ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Interleukin 1 ◽  
Enterotoxigenic Escherichia Coli ◽  
Cytokine Gene Expression ◽  
Cell Physiology ◽  
Intestinal Immunity ◽  
T84 Cells ◽  
Heat Stable ◽  
The Impact

ABSTRACT Enterotoxigenic Escherichia coli (ETEC) is a major diarrheal pathogen in children in low- to middle-income countries. Previous studies identified heat-stable enterotoxin (ST)-producing ETEC as a prevalent diarrheal pathogen in children younger than 5 years. While many studies have evaluated the interaction of ETEC heat-labile enterotoxin (LT) with host epithelium and immunity, few investigations have attempted similar studies with ST. To further understand ST pathogenesis, we examined the impact of ST on cGMP localization, epithelial cell cytokine production, and antibody development following immunization. In addition to robust intracellular cGMP in T84 cells in the presence of phosphodiesterase inhibitors (PDEis) that prevent the breakdown of cyclic nucleotides, we found that prolonged ST intoxication induced extracellular cGMP accumulation in the presence or absence of PDEis. Further, ST intoxication induced luminal cGMP in vivo in mice, suggesting that secreted cGMP may have other cellular functions. Using transcriptome sequencing (RNA-seq) and quantitative PCR (qPCR), we demonstrated that ST intoxication, or treatment with the clinically used ST mimic linaclotide, altered inflammatory cytokine gene expression, including the interleukin 1 (IL-1) family member IL-33, which could also be induced by cell-permeative 8-Br-cGMP. Finally, when present during immunization, ST suppressed induction of antibodies to specific antigens. In conclusion, our studies indicate that ST modulates epithelial cell physiology and the interplay between the epithelial and immune compartments.

scholarly journals Genetic Fusions of Heat-Labile (LT) and Heat-Stable (ST) Toxoids of Porcine Enterotoxigenic Escherichia coli Elicit Neutralizing Anti-LT and Anti-STa antibodies

2009 ◽  
Vol 78 (1) ◽  
pp. 316-325 ◽  
Author(s):  
Weiping Zhang ◽  
Chengxian Zhang ◽  
David H. Francis ◽  
Ying Fang ◽  
David Knudsen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Diarrheal Disease ◽  
Rabbit Antiserum ◽  
Full Length ◽  
Enterotoxigenic Escherichia Coli ◽  
Farm Animals ◽  
Toxic Activity ◽  
Colonization Factor ◽  
Heat Stable ◽  
Heat Labile

ABSTRACT Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of diarrheal disease in humans and farm animals. E. coli fimbriae, or colonization factor antigens (CFAs), and enterotoxins, including heat-labile enterotoxins (LT) and heat-stable enterotoxins (ST), are the key virulence factors in ETEC diarrhea. Unlike fimbriae or LT, STa has not often been included as an antigen in development of vaccines against ETEC diarrhea because of its poor immunogenicity. STa becomes immunogenic only after being coupled with a strongly immunogenic carrier protein. However, native or shorter STa antigens either had to retain toxic activity in order to become antigenic or elicited anti-STa antibodies that were not sufficiently protective. In this study, we genetically mutated the porcine LT (pLT) gene for a pLT192(R→G) toxoid and the porcine STa (pSTa) gene for three full-length pSTa toxoids [STa11(N→K), STa12(P→F), and STa13(A→Q)] and used the full-length pLT192 as an adjuvant to carry the pSTa toxoid for pLT192:pSTa-toxoid fusion antigens. Rabbits immunized with pLT192:pSTa12 or pLT192:pSTa13 fusion protein developed high titers of anti-LT and anti-STa antibodies. Furthermore, rabbit antiserum and antifecal antibodies were able to neutralize purified cholera toxin (CT) and STa toxin. In addition, preliminary data suggested that suckling piglets born by a sow immunized with the pLT192:pSTa13 fusion antigen were protected when challenged with an STa-positive ETEC strain. This study demonstrated that pSTa toxoids are antigenic when fused with a pLT toxoid and that the elicited anti-LT and anti-STa antibodies were protective. This fusion strategy could provide instructive information to develop effective toxoid vaccines against ETEC-associated diarrhea in animals and humans.

scholarly journals Feed Fermentation with Reuteran- and Levan-Producing Lactobacillus reuteri Reduces Colonization of Weanling Pigs by Enterotoxigenic Escherichia coli

2015 ◽  
Vol 81 (17) ◽  
pp. 5743-5752 ◽  
Author(s):  
Yan Yang ◽  
Sandra Galle ◽  
Minh Hong Anh Le ◽  
Ruurd T. Zijlstra ◽  
Michael G. Gänzle
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Reuteri ◽  
Control Diet ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Heat Stable ◽  
Copy Numbers ◽  
Fermented Feed ◽  
The Impact

ABSTRACTThis study determined the effect of feed fermentation withLactobacillus reuterion growth performance and the abundance of enterotoxigenicEscherichia coli(ETEC) in weanling piglets.L. reuteristrains produce reuteran or levan, exopolysaccharides that inhibit ETEC adhesion to the mucosa, and feed fermentation was conducted under conditions supporting exopolysaccharide formation and under conditions not supporting exopolysaccharide formation. Diets were chosen to assess the impact of organic acids and the impact of viableL. reuteribacteria. Fecal samples were taken throughout 3 weeks of feeding; at the end of the 21-day feeding period, animals were euthanized to sample the gut digesta. The feed intake was reduced in pigs fed diets containing exopolysaccharides; however, feed efficiencies did not differ among the diets. Quantification ofL. reuteriby quantitative PCR (qPCR) detected the two strains used for feed fermentation throughout the intestinal tract. Quantification ofE. coliand ETEC virulence factors by qPCR demonstrated that fermented diets containing reuteran significantly (P< 0.05) reduced the copy numbers of genes forE. coliand the heat-stable enterotoxin in feces compared to those achieved with the control diet. Any fermented feed significantly (P< 0.05) reduced the abundance ofE. coliand the heat-stable enterotoxin in colonic digesta at 21 days; reuteran-containing diets reduced the copy numbers of the genes forE. coliand the heat-stable enterotoxin below the detection limit in samples from the ileum, the cecum, and the colon. In conclusion, feed fermentation withL. reuterireduced the level of colonization of weaning piglets with ETEC, and feed fermentation supplied concentrations of reuteran that may specifically contribute to the effect on ETEC.

Marital Satisfaction of Portuguese Families in Times of Social Lockdown

2021 ◽  
pp. 106648072110098
Author(s):  
Carla Sílvia Fernandes ◽  
Bruno Magalhães ◽  
Sílvia Silva ◽  
Beatriz Edra
Keyword(s):  
Marital Satisfaction ◽  
Exploratory Study ◽  
Social Economic ◽  
Future Research ◽  
Marital Relations ◽  
The Social ◽  
The Family ◽  
Convenience Sampling ◽  
Global Threat ◽  
The Impact

The COVID-19 pandemic represents a global threat and crisis situation, and its wide-reaching impact has also affected marital satisfaction. Dysfunction of the marital system puts the survival of the family unit at risk. This research aimed to determine the level of marital satisfaction of Portuguese families during the social lockdown and the association between the variables under study. A descriptive, exploratory study was conducted. During the social lockdown, 276 people of Portuguese nationality and residing in Portugal were recruited using nonprobabilistic convenience sampling. Marital satisfaction in the pandemic phase showed low values that may be associated with the social, economic, and political context experienced by the pandemic situation. Future research must be carried out in order to identify, prevent, and intervene in situations of violence. In addition, future research should explore not only marital satisfaction during the current pandemic but a more systemic assessment of marital relations during crises, expanding the impact of marital satisfaction in family functioning.

scholarly journals Phony peach disease: past and present impact on the peach industry in the southeastern U.S.A

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Kendall A. Johnson ◽  
Clive H. Bock ◽  
Phillip M. Brannen
Keyword(s):  
New Technologies ◽  
Current Knowledge ◽  
Future Research ◽  
Management Options ◽  
Disease Epidemiology ◽  
Pathogen Diversity ◽  
Foundational Research ◽  
Global Threat ◽  
And Control ◽  
The Impact

Abstract Background Phony peach disease (PPD) is caused by the plant pathogenic bacterium Xylella fastidiosa subsp. multiplex (Xfm). Historically, the disease has caused severe yield loss in Georgia and elsewhere in the southeastern United States, with millions of PPD trees being removed from peach orchards over the last century. The disease remains a production constraint, and management options are few. Limited research has been conducted on PPD since the 1980s, but the advent of new technologies offers the opportunity for new, foundational research to form a basis for informed management of PPD in the U.S. Furthermore, considering the global threat of Xylella to many plant species, preventing import of Xfm to other regions, particularly where peach is grown, should be considered an important phytosanitary endeavor. Main topics We review PPD, its history and impact on peach production, and the eradication efforts that were conducted for 42 years. Additionally, we review the current knowledge of the pathogen, Xfm, and how that knowledge relates to our understanding of the peach—Xylella pathosystem, including the epidemiology of the disease and consideration of the vectors. Methods used to detect the pathogen in peach are discussed, and ramifications of detection in relation to management and control of PPD are considered. Control options for PPD are limited. Our current knowledge of the pathogen diversity and disease epidemiology are described, and based on this, some potential areas for future research are also considered. Conclusion There is a lack of recent foundational research on PPD and the associated strain of Xfm. More research is needed to reduce the impact of this pathogen on peach production in the southeastern U.S., and, should it spread internationally, wherever peaches are grown.

scholarly journals Deletion of FaeG alleviated Enterotoxigenic Escherichia coli F4ac-induced apoptosis in the intestine

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pengpeng Xia ◽  
Yunping Wu ◽  
Siqi Lian ◽  
Guomei Quan ◽  
Yiting Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Symptoms ◽  
Mucosal Damage ◽  
Enterotoxigenic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Antibody Microarray ◽  
E Coli ◽  
Fimbrial Subunit ◽  
Induced Apoptosis ◽  
Weaning Piglets

AbstractEnterotoxigenic Escherichia coli (ETEC) F4ac is a major constraint to the development of the pig industry, which is causing newborn and post-weaning piglets diarrhea. Previous studies proved that FaeG is the major fimbrial subunit of F4ac E. coli and efficient for bacterial adherence and receptor recognition. Here we show that the faeG deletion attenuates both the clinical symptoms of F4ac infection and the F4ac-induced intestinal mucosal damage in piglets. Antibody microarray analysis and the detection of mRNA expression using porcine neonatal jejunal IPEC-J2 cells also determined that the absence of FaeG subunit alleviated the F4ac promoted apoptosis in the intestinal epithelial cells. Thus, targeted depletion of FaeG is still beneficial for the prevention or treatment of F4ac infection.

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