scholarly journals Evaluating the Occurrence of Escherichia albertii in Chicken Carcass Rinses by PCR, Vitek Analysis, and Sequencing of therpoBGene

2014 ◽  
Vol 81 (5) ◽  
pp. 1727-1734 ◽  
Author(s):  
Rebecca L. Lindsey ◽  
Paula J. Fedorka-Cray ◽  
Melanie Abley ◽  
Jennifer B. Turpin ◽  
Richard J. Meinersmann
Keyword(s):  
Escherichia Coli ◽  
Causative Agent ◽  
Clinical Importance ◽  
Culture Methods ◽  
Hafnia Alvei ◽  
Content Type ◽  
Shiga Toxins ◽  
Heat Stable ◽  
Food Borne ◽  
Chicken Carcass

ABSTRACTEscherichia albertiiis a recently described species that has been associated with gastroenteritis in humans and with healthy and ill birds. Most recently, it has been identified as the causative agent in a food-borne outbreak in Japan. The distribution and clinical importance ofE. albertiiare not well studied because its importance is unclear. Culture methods for clinical isolation frequently missE. albertiior incorrectly identify it asShigellaspp.,Escherichia coli, orHafnia alvei. This study was designed to determine ifE. albertiicould be recovered from chicken carcass rinses collected at slaughter during a 1-year period from November 2009 until October 2010. Colonies were isolated from chicken carcass rinses and tested by PCR for the presence or absence ofclpX, lysP, mdh, intimin (eae), Shiga toxins 1 and 2 (stx1,stx2, andstx2f), heat-stable enterotoxin A (staA), and cytolethal distending toxins 1 and 2 (cdtB) genes. Sixty-five isolates were analyzed by sequencing a section of therpoBgene. Analysis of therpoBgene sequences revealed 14 fixed differences betweenE. albertiiand other, closely related organisms. The fixed differences found in therpoBgene could aid in future discrimination ofE. albertiifrom closely related bacteria.

scholarly journals Diversity of Shiga Toxin-Producing Escherichia coli (STEC) O26:H11 Strains Examined viastxSubtypes and Insertion Sites of Stx and EspK Bacteriophages

2015 ◽  
Vol 81 (11) ◽  
pp. 3712-3721 ◽  
Author(s):  
Ludivine Bonanno ◽  
Estelle Loukiadis ◽  
Patricia Mariani-Kurkdjian ◽  
Eric Oswald ◽  
Lucille Garnier ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Sequence Type ◽  
Phylogenetic Groups ◽  
Content Type ◽  
Shiga Toxins ◽  
E Coli ◽  
Food Borne ◽  
Insertion Sites ◽  
Human Infections

ABSTRACTShiga toxin-producingEscherichia coli(STEC) is a food-borne pathogen that may be responsible for severe human infections. Only a limited number of serotypes, including O26:H11, are involved in the majority of serious cases and outbreaks. The main virulence factors, Shiga toxins (Stx), are encoded by bacteriophages. Seventy-four STEC O26:H11 strains of various origins (including human, dairy, and cattle) were characterized for theirstxsubtypes and Stx phage chromosomal insertion sites. The majority of food and cattle strains possessed thestx1asubtype, while human strains carried mainlystx1aorstx2a. ThewrbAandyehVgenes were the main Stx phage insertion sites in STEC O26:H11, followed distantly byyecEandsbcB. Interestingly, the occurrence of Stx phages inserted in theyecEgene was low in dairy strains. In most of the 29stx-negativeE. coliO26:H11 strains also studied here, these bacterial insertion sites were vacant. Multilocus sequence typing of 20stx-positive orstx-negativeE. coliO26:H11 strains showed that they were distributed into two phylogenetic groups defined by sequence type 21 (ST21) and ST29. Finally, an EspK-carrying phage was found inserted in thessrAgene in the majority of the STEC O26:H11 strains but in only a minority of thestx-negativeE. coliO26:H11 strains. The differences in thestxsubtypes and Stx phage insertion sites observed in STEC O26:H11 according to their origin might reflect that strains circulating in cattle and foods are clonally distinct from those isolated from human patients.

scholarly journals Fecal Metagenome Sequences from Lactating Dairy Cows Shedding Escherichia coli O157:H7

2018 ◽  
Vol 7 (18) ◽  
Author(s):  
Serajus Salaheen ◽  
Seon Woo Kim ◽  
Jeffrey S. Karns ◽  
Bradd J. Haley ◽  
Jo Ann S. Van Kessel
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Causative Agent ◽  
Public Domain ◽  
Escherichia Coli O157 ◽  
Content Type ◽  
The Public ◽  
E Coli ◽  
Lactating Dairy Cows ◽  
Human Infections

Cattle are primary reservoirs of Escherichia coli O157:H7, a causative agent of severe human infections. To facilitate analyses of the communities in which this pathogen is found, we sequenced the fecal metagenomes of 10 dairy cows shedding E. coli O157:H7 and added them to the public domain.

scholarly journals Mechanical Stimuli Affect Escherichia coli Heat-Stable Enterotoxin-Cyclic GMP Signaling in a Human Enteroid Intestine-Chip Model

2019 ◽  
Vol 88 (3) ◽  
Author(s):  
Laxmi Sunuwar ◽  
Jianyi Yin ◽  
Magdalena Kasendra ◽  
Katia Karalis ◽  
James Kaper ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Cyclic Gmp ◽  
Cyclic Stretch ◽  
Intestinal Bacterium ◽  
Mechanical Forces ◽  
Mechanical Stimuli ◽  
Content Type ◽  
Heat Stable ◽  
Static Conditions

ABSTRACT Modeling host-pathogen interactions with human intestinal epithelia using enteroid monolayers on permeable supports (such as Transwells) represents an alternative to animal studies or use of colon cancer-derived cell lines. However, the static monolayer model does not expose epithelial cells to mechanical forces normally present in the intestine, including luminal flow and serosal blood flow (shear force) or peristaltic forces. To determine the contribution of mechanical forces in the functional response of human small intestine to a virulence factor of a pathogenic intestinal bacterium, human jejunal enteroids were cultured as monolayers in microengineered fluidic-based Organ-Chips (Intestine-Chips) exposed to enterotoxigenic Escherichia coli heat-stable enterotoxin A (ST) and evaluated under conditions of static fluid, apical and basolateral flow, and flow plus repetitive stretch. Application of flow increased epithelial cell height and apical and basolateral secretion of cyclic GMP (cGMP) under baseline, unstimulated conditions. Addition of ST under flow conditions increased apical and basolateral secretion of cGMP relative to the level under static conditions but did not enhance intracellular cGMP accumulation. Cyclic stretch did not have any significant effect beyond that contributed by flow. This study demonstrates that fluid flow application initiates changes in intestinal epithelial cell characteristics relative to those of static culture conditions under both baseline conditions and with exposure to ST enterotoxin and suggests that further investigations of the application of these mechanical forces will provide insights into physiology and pathophysiology that more closely resemble intact intestine than study under static conditions.

scholarly journals Enterotoxigenic Escherichia coli Prevents Host NF-κB Activation by Targeting IκBα Polyubiquitination

2012 ◽  
Vol 80 (12) ◽  
pp. 4417-4425 ◽  
Author(s):  
Xiaogang Wang ◽  
Philip R. Hardwidge
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Diarrheal Disease ◽  
Innate Immune ◽  
Host Cells ◽  
Enterotoxigenic Escherichia Coli ◽  
Host Responses ◽  
Innate Immune Responses ◽  
Content Type ◽  
Heat Stable

ABSTRACTThe NF-κB pathway regulates innate immune responses to infection. NF-κB is activated after pathogen-associated molecular patterns are detected, leading to the induction of proinflammatory host responses. As a countermeasure, bacterial pathogens have evolved mechanisms to subvert NF-κB signaling. EnterotoxigenicEscherichia coli(ETEC) causes diarrheal disease and significant morbidity and mortality for humans in developing nations. The extent to which this important pathogen subverts innate immune responses by directly targeting the NF-κB pathway is an understudied topic. Here we report that ETEC secretes a heat-stable, proteinaceous factor that blocks NF-κB signaling normally induced by tumor necrosis factor (TNF), interleukin-1β, and flagellin. Pretreating intestinal epithelial cells with ETEC supernatant significantly blocked the degradation of the NF-κB inhibitor IκBα without affecting IκBα phosphorylation. Data from immunoprecipitation experiments suggest that the ETEC factor functions by preventing IκBα polyubiquitination. Inhibiting clathrin function blocked the activity of the secreted ETEC factor, suggesting that this yet-uncharacterized activity may utilize clathrin-dependent endocytosis to enter host cells. These data suggest that ETEC evades the host innate immune response by directly modulating NF-κB signaling.

scholarly journals Identification of Antibiotics That Diminish Disease in a Murine Model of Enterohemorrhagic Escherichia coli Infection

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Sabrina Mühlen ◽  
Isabell Ramming ◽  
Marina C. Pils ◽  
Martin Koeppel ◽  
Jana Glaser ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enterohemorrhagic Escherichia Coli ◽  
Content Type ◽  
Shiga Toxins ◽  
Escherichia Coli Infection ◽  
Uremic Syndrome ◽  
Severity Of The Disease ◽  
Selection Of ◽  
Mild Diarrhea

ABSTRACT Infections with enterohemorrhagic Escherichia coli (EHEC) cause disease ranging from mild diarrhea to hemolytic-uremic syndrome (HUS) and are the most common cause of renal failure in children in high-income countries. The severity of the disease derives from the release of Shiga toxins (Stx). The use of antibiotics to treat EHEC infections is generally avoided, as it can result in increased stx expression. Here, we systematically tested different classes of antibiotics and found that their influence on stx expression and release varies significantly. We assessed a selection of these antibiotics in vivo using the Citrobacter rodentium ϕstx2dact mouse model and show that stx2d-inducing antibiotics resulted in weight loss and kidney damage despite clearance of the infection. However, several non-Stx-inducing antibiotics cleared bacterial infection without causing Stx-mediated pathology. Our results suggest that these antibiotics might be useful in the treatment of EHEC-infected human patients and decrease the risk of HUS development.

scholarly journals Predicting the Presence of Non-O157 Shiga Toxin-Producing Escherichia coli in Ground Beef by Using Molecular Tests for Shiga Toxins, Intimin, and O Serogroups

2012 ◽  
Vol 78 (19) ◽  
pp. 7152-7155 ◽  
Author(s):  
Joseph M. Bosilevac ◽  
Mohammad Koohmaraie
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Ground Beef ◽  
Content Type ◽  
Shiga Toxins ◽  
Molecular Tests

ABSTRACTWhen 3,972 ground beef enrichments with 6 confirmed to contain a non-O157 Shiga toxin-producing intimin-positiveEscherichia coliisolate were tested for Shiga toxin, intimin, and O group (O26, O45, O103, O111, O121, and O145) genes, 183 potential positives and only 2 of the 6 confirmed positives were identified.

scholarly journals Towards Rational Design of a Toxoid Vaccine against the Heat-Stable Toxin of Escherichia coli

2016 ◽  
Vol 84 (4) ◽  
pp. 1239-1249 ◽  
Author(s):  
Arne M. Taxt ◽  
Yuleima Diaz ◽  
Rein Aasland ◽  
John D. Clements ◽  
James P. Nataro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rational Design ◽  
Diarrheal Disease ◽  
Cross Reactivity ◽  
Single Amino Acid ◽  
Minimal Risk ◽  
Content Type ◽  
Heat Stable ◽  
Low Toxicity ◽  
Mutant Forms

EnterotoxigenicEscherichia coli(ETEC) is an important cause of diarrheal disease and death in children <5 years old. ETEC strains that express the heat-stable toxin (ST), with or without the heat-labile toxin, are among the four most important diarrhea-causing pathogens. This makes ST an attractive target for an ETEC vaccine. An ST vaccine should be nontoxic and elicit an immune response that neutralizes native ST without cross-reacting with the human endogenous guanylate cyclase C receptor ligands. To identify variants of ST with no or low toxicity, we screened a library of all 361 possible single-amino-acid mutant forms of ST by using the T84 cell assay. Moreover, we identified mutant variants with intact epitopes by screening for the ability to bind neutralizing anti-ST antibodies. ST mutant forms with no or low toxicity and intact epitopes are termed toxoid candidates, and the top 30 candidates all had mutations of residues A14, N12, and L9. The identification of nontoxic variants of L9 strongly suggests that it is a novel receptor-interacting residue, in addition to the previously identified N12, P13, and A14 residues. The screens also allowed us to map the epitopes of three neutralizing monoclonal antibodies, one of which cross-reacts with the human ligand uroguanylin. The common dominant epitope residue for all non-cross-reacting antibodies was Y19. Our results suggest that it should be possible to rationally design ST toxoids that elicit neutralizing immune responses against ST with minimal risk of immunological cross-reactivity.

scholarly journals Behavior of Different Shiga Toxin-Producing Escherichia coli Serotypes in Various Experimentally Contaminated Raw-Milk Cheeses

2012 ◽  
Vol 79 (1) ◽  
pp. 150-158 ◽  
Author(s):  
Stéphane D. Miszczycha ◽  
Frédérique Perrin ◽  
Sarah Ganet ◽  
Emmanuel Jamet ◽  
Fanny Tenenhaus-Aziza ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Human Health Risk ◽  
Raw Milk ◽  
Public Health Implication ◽  
Content Type ◽  
Growth And Survival ◽  
The Public ◽  
Food Borne ◽  
Food Borne Illness

ABSTRACTShiga toxin-producingEscherichia coli(STEC) is an important cause of food-borne illness. The public health implication of the presence of STEC in dairy products remains unclear. Knowledge of STEC behavior in cheeses would help to evaluate the human health risk. The aim of our study was to observe the growth and survival of experimentally inoculated STEC strains in raw-milk cheeses manufactured and ripened according to five technological schemes: blue-type cheese, uncooked pressed cheese with long ripening and with short ripening steps, cooked cheese, and lactic cheese. Cheeses were contaminated with different STEC serotypes (O157:H7, O26:H11, O103:H2, and O145:H28) at the milk preparation stage. STEC growth and survival were monitored on selective media during the entire manufacturing process. STEC grew (2 to 3 log10CFU · g−1) in blue-type cheese and the two uncooked pressed cheeses during the first 24 h of cheese making. Then, STEC levels progressively decreased in cheeses that were ripened for more than 6 months. In cooked cheese and in lactic cheese with a long acidic coagulation step (pH < 4.5), STEC did not grow. Their levels decreased after the cooking step in the cooked cheese and after the coagulation step in the lactic cheese, but STEC was still detectable at the end of ripening and storage. A serotype effect was found: in all cheeses studied, serotype O157:H7 grew less strongly and was less persistent than the others serotypes. This study improves knowledge of the behavior of different STEC serotypes in various raw-milk cheeses.

scholarly journals 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

2011 ◽  
Vol 18 (10) ◽  
pp. 1593-1599 ◽  
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.

scholarly journals Genomic Diversity and Virulence Profiles of Historical Escherichia coli O157 Strains Isolated from Clinical and Environmental Sources

2014 ◽  
Vol 81 (2) ◽  
pp. 569-577 ◽  
Author(s):  
Lydia V. Rump ◽  
Narjol Gonzalez-Escalona ◽  
Wenting Ju ◽  
Fei Wang ◽  
Guojie Cao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
The United States ◽  
Genomic Diversity ◽  
Severe Illness ◽  
Pathogenic Potential ◽  
Content Type ◽  
E Coli ◽  
Virulence Markers ◽  
Virulence Potential ◽  
Food Borne

ABSTRACTEscherichia coliO157:H7 is, to date, the majorE. coliserotype causing food-borne human disease worldwide. Strains of O157 with other H antigens also have been recovered. We analyzed a collection of historic O157 strains (n= 400) isolated in the late 1980s to early 1990s in the United States. Strains were predominantly serotype O157:H7 (55%), and various O157:non-H7 (41%) serotypes were not previously reported regarding their pathogenic potential. Although lacking Shiga toxin (stx) andeaegenes, serotypes O157:H1, O157:H2, O157:H11, O157:H42, and O157:H43 carried several virulence factors (iha,terD, andhlyA) also found in virulent serotypeE. coliO157:H7. Pulsed-field gel electrophoresis (PFGE) showed the O157 serogroup was diverse, with strains with the same H type clustering together closely. Among non-H7 isolates, serotype O157:H43 was highly prevalent (65%) and carried important enterohemorrhagicE. coli(EHEC) virulence markers (iha,terD,hlyA, andespP). Isolates from two particular H types, H2 and H11, among the most commonly found non-O157 EHEC serotypes (O26:H11, O111:H11, O103:H2/H11, and O45:H2), unexpectedly clustered more closely with O157:H7 than other H types and carried several virulence genes. This suggests an early divergence of the O157 serogroup to clades with different pathogenic potentials. The appearance of important EHEC virulence markers in closely related H types suggests their virulence potential and suggests further monitoring of those serotypes not implicated in severe illness thus far.

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