Research

8 pages, 1607 KiB

Open AccessArticle

Novel Effector Protein EspY3 of Type III Secretion System from Enterohemorrhagic Escherichia coli Is Localized in Actin Pedestals

by Mariano Larzábal, Wanderson Marques Da Silva, Nahuel A. Riviere and Ángel A. Cataldi

Microorganisms 2018, 6(4), 112; https://doi.org/10.3390/microorganisms6040112 - 27 Oct 2018

Cited by 10 | Viewed by 3693

Abstract

Enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic Escherichia coli (EPEC) are attaching and effacing (A/E) pathogens, which translocate effector proteins to intestinal enterocytes through a type III secretion system (T3SS). T3SS and most of its effector proteins are encoded in a pathogenicity island called [...] Read more.

Enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic Escherichia coli (EPEC) are attaching and effacing (A/E) pathogens, which translocate effector proteins to intestinal enterocytes through a type III secretion system (T3SS). T3SS and most of its effector proteins are encoded in a pathogenicity island called LEE. Recently, new effectors have been located outside the LEE. This study aimed to characterize EspY3, a novel non-LEE encoded T3SS effector of EHEC. EspY3 shares homology with SopD and PipB2 effector proteins of Salmonella’s T3SS-1 and T3SS-2, respectively. The presence of recombinant EspY3 in the supernatant samples demonstrated that EspY3 was secreted by the T3SS of EHEC and EPEC. Through infection assays, we demonstrated the translocation of EspY3 into Caco-2 cells by T3SS of EPEC. The subcellular localization of EspY3 was determined in the pedestal region, where its presence generates a significant increase in the size of the pedestals area. The EspY3 effector induced the elongation of polymerized actin pedestals in infected Caco-2 by EPEC. This study confirmed that EspY3 is part of the repertoire of T3SS effectors of EHEC O157:H7, and that it participates in modeling cellular actin during the infection. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

► Show Figures

Figure 1

18 pages, 1558 KiB

Open AccessArticle

Variability in Characterizing Escherichia coli from Cattle Feces: A Cautionary Tale

by Kim Stanford, Tim Reuter, Jennyka Hallewell, Renata Tostes, Trevor W. Alexander and Tim A. McAllister

Microorganisms 2018, 6(3), 74; https://doi.org/10.3390/microorganisms6030074 - 21 Jul 2018

Cited by 5 | Viewed by 4202

Abstract

Shiga toxin-producing Escherichia coli (STEC) are diverse bacteria, with seven serogroups (O26, O45, O103, O111, O121, O145, O157; “Top 7”) of interest due to their predominance in human disease. Confirmation of STEC relies on a combination of culturing, immunological and molecular assays, but [...] Read more.

Shiga toxin-producing Escherichia coli (STEC) are diverse bacteria, with seven serogroups (O26, O45, O103, O111, O121, O145, O157; “Top 7”) of interest due to their predominance in human disease. Confirmation of STEC relies on a combination of culturing, immunological and molecular assays, but no single gold standard for identification exists. In this study, we compared analysis of STEC between three independent laboratories (LAB) using different methodologies. In LAB A, colonies of Top 7 were picked after serogroup-specific immunomagnetic separation of feces from western-Canadian slaughter cattle. A fraction of each colony was tested by PCR (stx1, stx2, eae, O group), and Top 7 isolates were saved as glycerol stocks (n = 689). In LAB B, a subsample of isolates (n = 171) were evaluated for stx1 and stx2 using different primer sets. For this, approximately half of the PCR were performed using original DNA template provided by LAB A and half using DNA extracted from sub-cultured isolates. All Top 7 isolates were sub-cultured by LAB A and shipped to LAB C for traditional serotyping (TS) to determine O and H groups, with PCR-confirmation of virulence genes using a third set of primers. By TS, 76% of O groups (525/689) matched PCR-determined O groups. Lowest proportions (p < 0.05) of O group matches between PCR and TS (62.6% and 69.8%) occurred for O26 and O45 serogroups, respectively. PCR-detection of stx differed most between LAB A and LAB C. Excluding isolates where O groups by PCR and TS did not match, detection of stx1 was most consistent (p < 0.01) for O111 and O157:H7/NM. In contrast, for O45 and O103, stx1 was detected in >65% of isolates by LAB A and <5% by LAB C. Stx2 was only detected by LAB C in isolates of serogroups O121, O145, and O157:H7/NM. LAB B also detected stx2 in O26 and O157:H12/H29, while LAB A detected stx2 in all serogroups. Excluding O111 and O157:H7/NM, marked changes in stx detection were observed between initial isolation and sub-cultures of the same isolate. While multiple explanations exist for discordant O-typing between PCR and TS and for differences in stx detection across labs, these data suggest that assays for STEC classification may require re-evaluation and/or standardization. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

► Show Figures

Figure 1

22 pages, 692 KiB

Open AccessArticle

Zoonotic Fecal Pathogens and Antimicrobial Resistance in Canadian Petting Zoos

by Cheyenne C. Conrad, Kim Stanford, Claudia Narvaez-Bravo, Norman F. Neumann, Krysty Munns, Lisa Tymensen, Cassandra Jokinen and Tim A. McAllister

Microorganisms 2018, 6(3), 70; https://doi.org/10.3390/microorganisms6030070 - 16 Jul 2018

Cited by 16 | Viewed by 6069

Abstract

This study aimed to better understand the potential public health risk associated with zoonotic pathogens in agricultural fairs and petting zoos in Canada. Prevalence of Salmonella, Shiga toxin-producing Escherichia coli (STEC) O157:H7, and top six non-O157 STEC serogroups in feces (n [...] Read more.

This study aimed to better understand the potential public health risk associated with zoonotic pathogens in agricultural fairs and petting zoos in Canada. Prevalence of Salmonella, Shiga toxin-producing Escherichia coli (STEC) O157:H7, and top six non-O157 STEC serogroups in feces (n = 88), hide/feather (n = 36), and hand rail samples (n = 46) was assessed, as well as distributions of antimicrobial resistant (AMR) broad and extended-spectrum β-lactamase (ESBL)-producing E. coli. Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in pig nasal swabs (n = 4), and Campylobacter, Cryptosporidium, and Giardia in feces was also assessed. Neither Salmonella nor MRSA were detected. Campylobacter spp. were isolated from 32% of fecal samples. Cryptosporidium and Giardia were detected in 2% and 15% of fecal samples, respectively. Only one fecal sample was positive for STEC O157, whereas 22% were positive for non-O157 STEC. Multi-drug resistance (MDR) to antibiotics classified as critically and highly important in human medicine was proportionally greatest in E. coli from cattle feces. The β-lactamase-producing E. coli from pig, horse/donkey feces, and hand rail samples, as well as the STEC E. coli from handrail swabs were MDR. The diversity and prevalence of zoonotic pathogens and AMR bacteria detected within agricultural fairs and petting zoos emphasize the importance of hygienic practices and sanitization with respect to reducing associated zoonotic risks. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

► Show Figures

Figure 1

Review

Jump to: Research, Other

16 pages, 767 KiB

Open AccessReview

Complement Activation Contributes to the Pathophysiology of Shiga Toxin-Associated Hemolytic Uremic Syndrome

by Simona Buelli, Carlamaria Zoja, Giuseppe Remuzzi and Marina Morigi

Microorganisms 2019, 7(1), 15; https://doi.org/10.3390/microorganisms7010015 - 10 Jan 2019

Cited by 22 | Viewed by 6665

Abstract

Shiga toxin (Stx)-producing Escherichia coli (STEC) infections have become a threat to public health globally because of the severe illnesses that they can trigger, such as hemorrhagic colitis and the post-diarrheal hemolytic uremic syndrome (HUS), characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute [...] Read more.

Shiga toxin (Stx)-producing Escherichia coli (STEC) infections have become a threat to public health globally because of the severe illnesses that they can trigger, such as hemorrhagic colitis and the post-diarrheal hemolytic uremic syndrome (HUS), characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney failure. Glomerular endothelial cells are primary targets of Stx which, after binding to its specific receptor globotriaosylceramide, upregulates proinflammatory proteins involved both in the recruitment and adhesion of leukocytes and thrombus formation at the site of endothelial injury. In this review, we discuss the role of complement activation in promoting glomerular microvascular dysfunction, providing evidence from experimental models and patients with STEC-HUS. Within the glomerulus, an important target for Stx-induced complement activation is the podocyte, a cell type that is in close contact with endothelial cells and participates in maintaining the filtration barrier. Recently, podocyte injury and loss have been indicated as potential risk factors for long-term renal sequelae in patients with STEC-HUS. Therapeutic approaches targeting the complement system, that may be useful options for patients with STEC-HUS, will also be discussed. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

► Show Figures

Figure 1

34 pages, 2700 KiB

Open AccessReview

Modulation of Enterohaemorrhagic Escherichia coli Survival and Virulence in the Human Gastrointestinal Tract

by Grégory Jubelin, Mickaël Desvaux, Stephanie Schüller, Lucie Etienne-Mesmin, Maite Muniesa and Stéphanie Blanquet-Diot

Microorganisms 2018, 6(4), 115; https://doi.org/10.3390/microorganisms6040115 - 19 Nov 2018

Cited by 37 | Viewed by 7990

Abstract

Enterohaemorrhagic Escherichia coli (EHEC) is a major foodborne pathogen responsible for human diseases ranging from diarrhoea to life-threatening complications. Survival of the pathogen and modulation of virulence gene expression along the human gastrointestinal tract (GIT) are key features in bacterial pathogenesis, but remain [...] Read more.

Enterohaemorrhagic Escherichia coli (EHEC) is a major foodborne pathogen responsible for human diseases ranging from diarrhoea to life-threatening complications. Survival of the pathogen and modulation of virulence gene expression along the human gastrointestinal tract (GIT) are key features in bacterial pathogenesis, but remain poorly described, due to a paucity of relevant model systems. This review will provide an overview of the in vitro and in vivo studies investigating the effect of abiotic (e.g., gastric acid, bile, low oxygen concentration or fluid shear) and biotic (e.g., gut microbiota, short chain fatty acids or host hormones) parameters of the human gut on EHEC survival and/or virulence (especially in relation with motility, adhesion and toxin production). Despite their relevance, these studies display important limitations considering the complexity of the human digestive environment. These include the evaluation of only one single digestive parameter at a time, lack of dynamic flux and compartmentalization, and the absence of a complex human gut microbiota. In a last part of the review, we will discuss how dynamic multi-compartmental in vitro models of the human gut represent a novel platform for elucidating spatial and temporal modulation of EHEC survival and virulence along the GIT, and provide new insights into EHEC pathogenesis. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

► Show Figures

Figure 1

10 pages, 511 KiB

Open AccessReview

Shiga Toxin-Producing Escherichia coli Infections during Pregnancy

by Flavia Sacerdoti, María Luján Scalise, Juliana Burdet, María Marta Amaral, Ana María Franchi and Cristina Ibarra

Microorganisms 2018, 6(4), 111; https://doi.org/10.3390/microorganisms6040111 - 23 Oct 2018

Cited by 11 | Viewed by 6779

Abstract

Gastrointestinal infection with Shiga toxin-producing Escherichia coli (STEC) causes diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS), characterized by hemolytic anemia, thrombocytopenia and acute renal failure. The main virulence factor of STEC is Shiga toxin (Stx), which is responsible for HUS development. STEC [...] Read more.

Gastrointestinal infection with Shiga toxin-producing Escherichia coli (STEC) causes diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS), characterized by hemolytic anemia, thrombocytopenia and acute renal failure. The main virulence factor of STEC is Shiga toxin (Stx), which is responsible for HUS development. STEC can produce Stx type 1 and/or 2 (Stx1, Stx2) and their variants, Stx2 being more frequently associated with severe cases of HUS. This pathology occurs in 5–15% of cases with STEC infection when Stx gain access to the bloodstream and causes damage in the target organs such as the kidney and brain. STEC infections affect mainly young children, although the large HUS outbreak with a new Stx2-producing STEC O104:H4 in Europe in 2011 involved more adults than children, and women were over-represented. Maternal infections during pregnancy are associated with adverse pregnancy outcomes. Studies in rats showed that Stx2 binds to the utero-placental unit and causes adverse pregnancy outcomes. In this article, we provide a brief overview of Stx2 action on placental tissues and discuss whether they might cause pregnancy loss or preterm birth. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

► Show Figures

Graphical abstract

19 pages, 759 KiB

Open AccessReview

Recent Advances in Shiga Toxin-Producing Escherichia coli Research in Latin America

by Alfredo G. Torres, Maria M. Amaral, Leticia Bentancor, Lucia Galli, Jorge Goldstein, Alejandra Krüger and Maricarmen Rojas-Lopez

Microorganisms 2018, 6(4), 100; https://doi.org/10.3390/microorganisms6040100 - 28 Sep 2018

Cited by 39 | Viewed by 6512

Abstract

Pathogenic Escherichia coli are known to be a common cause of diarrheal disease and a frequently occurring bacterial infection in children and adults in Latin America. Despite the effort to combat diarrheal infections, the south of the American continent remains a hot spot [...] Read more.

Pathogenic Escherichia coli are known to be a common cause of diarrheal disease and a frequently occurring bacterial infection in children and adults in Latin America. Despite the effort to combat diarrheal infections, the south of the American continent remains a hot spot for infections and sequelae associated with the acquisition of one category of pathogenic E. coli, the Shiga toxin-producing E. coli (STEC). This review will focus on an overview of the prevalence of different STEC serotypes in human, animals and food products, focusing on recent reports from Latin America outlining the recent research progress achieved in this region to combat disease and endemicity in affected countries and to improve understanding on emerging serotypes and their virulence factors. Furthermore, this review will highlight the progress done in vaccine development and treatment and will also discuss the effort of the Latin American investigators to respond to the thread of STEC infections by establishing a multidisciplinary network of experts that are addressing STEC-associated animal, human and environmental health issues, while trying to reduce human disease. Regardless of the significant scientific contributions to understand and combat STEC infections worldwide, many significant challenges still exist and this review has focus in the Latin American efforts as an example of what can be accomplished when multiple groups have a common goal. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

► Show Figures

Figure 1

16 pages, 337 KiB

Open AccessReview

Genotypic Features of Clinical and Bovine Escherichia coli O157 Strains Isolated in Countries with Different Associated-Disease Incidences

by Luis Pianciola and Marta Rivas

Microorganisms 2018, 6(2), 36; https://doi.org/10.3390/microorganisms6020036 - 27 Apr 2018

Cited by 20 | Viewed by 3997

Abstract

There is great geographical variation in the frequency of Escherichia coli O157 infections that correlates with important differences in the bovine reservoir of each country. Our group carried out a broad molecular characterization of human and bovine E. coli O157 strains circulating in [...] Read more.

There is great geographical variation in the frequency of Escherichia coli O157 infections that correlates with important differences in the bovine reservoir of each country. Our group carried out a broad molecular characterization of human and bovine E. coli O157 strains circulating in Argentina using different methodologies. Our data allows us to conclude that in Argentina, a high homogeneity is observed in both cattle and human strains, with almost exclusive circulation of strains belonging to the hypervirulent clade 8 described by Manning. The aim of this review was to compare the genetic background of E. coli O157 strains isolated in countries that have conducted similar studies, to try to correlate specific O157 genotypes with the incidence and severity of E. coli O157 associated diseases. The characteristics of the strains that cause disease in humans reflect the predominant genotypes in cattle in each of the countries analyzed. The main features clearly linked to high incidence or severity of E. coli O157 infections are lineage-specific polymorphism assay-6 lineage I/II, clade 8 strains and probably, clade 6 strains, the stx_2a/stx_2c genotype, the presence of q933 and q21 simultaneously, and putative virulence factor EC_3286. In countries with an absence of these features in O157 strains, the overall incidence of O157 disease is low. Argentina, where these characteristics are detected in most strains, shows the highest incidence of hemolytic uremic syndrome (HUS) worldwide. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

Other

Jump to: Research, Review

8 pages, 243 KiB

Open AccessBrief Report

Antimicrobial Resistance in Class 1 Integron-Positive Shiga Toxin-Producing Escherichia coli Isolated from Cattle, Pigs, Food and Farm Environment

by Rocío Colello, Alejandra Krüger, José Di Conza, John W. A. Rossen, Alexander W. Friedrich, Gabriel Gutkind, Analía I. Etcheverría and Nora L. Padola

Microorganisms 2018, 6(4), 99; https://doi.org/10.3390/microorganisms6040099 - 28 Sep 2018

Cited by 14 | Viewed by 3768

Abstract

The aim of this study was to investigate the presence of class 1 integrons in a collection of Shiga toxin-producing Escherichia coli (STEC) from different origins and to characterize pheno- and genotypically the antimicrobial resistance associated to them. A collection of 649 isolates [...] Read more.

The aim of this study was to investigate the presence of class 1 integrons in a collection of Shiga toxin-producing Escherichia coli (STEC) from different origins and to characterize pheno- and genotypically the antimicrobial resistance associated to them. A collection of 649 isolates were screened for the class 1 integrase gene (intI1) by Polymerase chain reaction The variable region of class 1 integrons was amplified and sequenced. Positive strains were evaluated for the presence of antimicrobial resistance genes with microarray and for antimicrobial susceptibility by the disk diffusion method. Seven out of 649 STEC strains some to serogroups, O26, O103 and O130 isolated from cattle, chicken burger, farm environment and pigs were identified as positive for intl1. Different arrangements of gene cassettes were detected in the variable region of class 1 integron: dfrA16, aadA23 and dfrA1-aadA1. In almost all strains, phenotypic resistance to streptomycin, tetracycline, trimethoprim/sulfamethoxazole, and sulfisoxazole was observed. Microarray analyses showed that most of the isolates carried four or more antimicrobial resistance markers and STEC strains were categorized as Multridrug-resistant. Although antimicrobials are not usually used in the treatment of STEC infections, the presence of Multridrug-resistant in isolates collected from farm and food represents a risk for animal and human health. Full article

(This article belongs to the Special Issue Pathogenesis of Enterohaemorrhagic Escherichia coli)

Journal Menu

Journal Browser

Pathogenesis of Enterohaemorrhagic Escherichia coli

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Related Special Issue

Published Papers (9 papers)

Research

Review

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI