scholarly journals Enterotoxic, neurotoxic and cytotoxice demonstrated by shiga toxin (2d) producing escherichia coli in experimental models

2020 ◽  
Vol 46 (1) ◽  
pp. 41-47
Author(s):  
Chowdhury Rafiqul Ahsan ◽  
Kohinur Begum ◽  
Enamul Kabir ◽  
Alam Nur-E- Kamal ◽  
Kaisar Ali Talukder
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Cytotoxic Effect ◽  
Kidney Tissue ◽  
Clinical Manifestations ◽  
Diarrhoeal Disease ◽  
Experimental Models ◽  
Histopathological Study ◽  
Ileal Loop ◽  
Study Results

Background: Shiga toxin (Stx) producing Escherichia coli (STEC) colonize human intestinal tract and their infections have asymptomatic clinical manifestations which cause local and systemic pathological changes. Objectives: This study intended to establish the role of Shiga toxin (Stx2d) in developing clinical manifestations in STEC infections using experimental models. Methods: A total 300 stool samples were screened from hospitalised diarrhoeal patients enrolled in 2% surveillance system at International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b). The stx gene profile including their variants was identified byPCR.stx2d gene positive STEC PT187 was selected for toxin (s) preparation.Toxin was prepared by centrifugation of culture supernatant. Enterotoxicand paralytic-lethal activities were tested in rabbit ileal loops and mice, respectively.  Histopathological study of the rabbit ileal loop segments and different tissues of mice  by paraffin embedded method and stained by H & E staining. Cytotoxic effect was performed on  HeLa cells. Results: Nine STEC strains were identified for stx2 gene positive.  Among them STEC PT187 was found stx2d gene positive strain and selected for toxic activities. Toxin (s) responsible for causing accumulation of fluid in rabbit ileal loops and its segments showed inflammation and enterocytenecrosis. In mouse model, toxin(s) was found to cause hind limbs paralysis and death. Brain, spinal cord and kidney tissue of mice showed histopathological changes. Toxin (s) also showed positive cytotoxic activity in HeLa cell. Conclusion: In this study, results indicated that Stx2d producing E. coli exhibit not only enterotoxic activity, but also cause impaired neurological functions and cytotoxic effect. Bangladesh Med Res Counc Bull 2020; 46(1): 41-47

scholarly journals The first documented case of enterocolitis in Yugoslavia caused by enterohemorrhagic Escherichia coli 0517

2003 ◽  
Vol 60 (4) ◽  
pp. 493-496 ◽  
Author(s):  
Miloje Cobeljic ◽  
Ivanko Bojic ◽  
Dolores Opacic ◽  
Zorica Lepsanovic ◽  
Srdjan Lazic
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Cytotoxic Effect ◽  
Diarrhoeal Disease ◽  
Enterohemorrhagic Escherichia Coli ◽  
First Case ◽  
Potential Development ◽  
Uremic Syndrome ◽  
Pathogenic Agents ◽  
Extraintestinal Complications

A ?new? group of pathogenic agents, enterohemorrhagic Escherichia coli (EHEC) (particularly the strains of O157 serogroup), emerged in the last 20 years causing an increased number of sporadic and epidemic diarrhoeal diseases with hemorrhagic enterocolitis as a most common clinical manifestation of the infection. As a consequence of the absorption and cytotoxic effect of the main virulence factor of these bacteria - verotoxin (shiga-toxin), in about 10% of the affected persons extraintestinal complications, most frequently hemolytic-uremic syndrome (HUS), occurred 7-14 days after an episode of diarrhoeal disease. The first case of hemorrhagic enterocolitis with the documented EHEC O157 infection in Yugoslavia is presented in this paper. Considering the existing expansion trend of these carriers, practitioners should be aware of them in case of the occurrence of diarrhoeal disease (particularly hemorrhagic enterocolitis), and keep these patients under control during the reconvalescence period because of potential development of extraintestinal complications, such as HUS.

scholarly journals Contribution of Urease to Colonization by Shiga Toxin-Producing Escherichia coli

2012 ◽  
Vol 80 (8) ◽  
pp. 2589-2600 ◽  
Author(s):  
Susan R. Steyert ◽  
James B. Kaper
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Type Strain ◽  
Nitrogen Availability ◽  
Wild Type Strain ◽  
Clinical Manifestations ◽  
Maximum Activity ◽  
Wild Type ◽  
Urease Enzyme

ABSTRACTShiga toxin-producingEscherichia coli(STEC) is a food-borne pathogen with a low infectious dose that colonizes the colon in humans and can cause severe clinical manifestations such as hemolytic-uremic syndrome. The urease enzyme, encoded in the STEC chromosome, has been demonstrated to act as a virulence factor in other bacterial pathogens. The NH3produced as urease hydrolyzes urea can aid in buffering bacteria in acidic environments as well as provide an easily assimilated source of nitrogen that bacteria can use to gain a metabolic advantage over intact microflora. Here, we explore the role of urease in STEC pathogenicity. The STEC urease enzyme exhibited maximum activity near neutral pH and during the stationary-growth phase. Experiments altering growth conditions performed with three phylogenetically distinct urease-positive strains demonstrated that the STECuregene cluster is inducible by neither urea nor pH but does respond to nitrogen availability. Quantitative reverse transcription-PCR (qRT-PCR) data indicate that nitrogen inhibits the transcriptional response. The deletion of theuregene locus was constructed in STEC strain 88-0643, and theuremutant was used with the wild-type strain in competition experiments in mouse models to examine the contribution of urease. The wild-type strain was twice as likely to survive passage through the acidic stomach and demonstrated an enhanced ability to colonize the intestinal tract compared to theuremutant strain. Thesein vivoexperiments reveal that, although the benefit STEC gains from urease expression is modest and not absolutely required for colonization, urease can contribute to the pathogenicity of STEC.

scholarly journals P0334HEMOLYTIC UREMIC SYNDROME: CLINICAL PRESENTATION, LABORATORY FINDINGS, MANAGEMENT AND OUTCOMES

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Issa Al Salmi ◽  
AbdelMasiah Metry ◽  
SUAD Hannawi
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Hemolytic Anemia ◽  
Shiga Toxin ◽  
Post Partum ◽  
Kidney Injury ◽  
Partial Recovery ◽  
Laboratory Findings ◽  
Study Results ◽  
Uremic Syndrome

Abstract Background and Aims Hemolytic-uremic syndrome (HUS) is a disease that has been described as a triad of hemolytic anemia, thrombocytopenia and renal impairment. There are two types of HUS, typical and atypical. HUS remains a leading cause of acute renal injury in children and is increasingly recognized as a cause of renal failure in adults. In our study we evaluated the demographic features, clinical characteristics, management and outcome of HUS. Method This is a descriptive study evaluating all cases of Hemolytic Uremic Syndrome (HUS) that have been admitted at Royal Hospital (RH) Oman in the period between 2008 and 2017. Results Thirty-six patients identified. The mean age (SD) of 10.68 (14.07) years. Eighteen (50%) presented with abdominal pain, nausea, vomiting and diarrhea, 9 (25 %) with hypertension, 23 (64 %) with acute kidney injury (AKI), 6 (16.67%) with seizure, 2 (5.56%) with confusion and 1 (2.78%) with cerebrovascular accident (CVA). Twenty-one (58.33 %) diagnosed as typical HUS of which 19 with Shiga toxin producing Escherichia Coli (STEC) HUS and 2 had post Streptococal HUS. Six (16.67%) diagnosed with aHUS, 2 (5.56%) with HELLP, 2 (5.56%) with G6PD, 3 (8.33%) with Autoimmune hemolytic anemia (AIHA ), one (2.78%) with congenital TTP and 1 (2.78%) with post partum HUS. Twenty three (63.89%) needed renal replacement therapy (RRT), while remaining 13 (36.11%) did not require RRT. Eleven (30.56%) received plasma exchange, 5 (13.89%) received Eculizumab while 2 (5.56%) received plasma infusion and 1 (2.78%) patient received Rituximab. The majority 22 (61.11%) had partial recovery after treatment, 5 (13.89 %) had compelte recovery and 3 (8.33% ) ended with end stage kidney disease (ESKD) and 1 (2.78%) died from hypertensive crises. Conclusion The study results showed that HUS population were mostly due to Shiga toxin producing Escherichia Coli (STEC). It showed that HUS population were young, mostly male and only 25% have known medical comorbidities at time of presentation. Also, the majority presented with AKI requiring dialysis, of which PD was main stay of therapy. The duration of RRT and recovery time was almost a month period.

scholarly journals Risk of haemolytic uraemic syndrome caused by shiga-toxin-producing Escherichia coli infection in adult women in Japan

2015 ◽  
Vol 144 (5) ◽  
pp. 952-961 ◽  
Author(s):  
J. FUJII ◽  
T. MIZOUE ◽  
T. KITA ◽  
H. KISHIMOTO ◽  
K. JOH ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Renal Failure ◽  
Shiga Toxin ◽  
Haemolytic Uraemic Syndrome ◽  
Fatal Case ◽  
Diarrhoeal Disease ◽  
Positive Control ◽  
Renal Tubules ◽  
Adult Women ◽  
Escherichia Coli Infection

SUMMARYShiga-toxin-producing Escherichia coli (STEC) infections usually cause haemolytic uraemic syndrome (HUS) equally in male and female children. This study investigated the localization of globotriaosylceramide (Gb3) in human brain and kidney tissues removed from forensic autopsy cases in Japan. A fatal case was used as a positive control in an outbreak of diarrhoeal disease caused by STEC O157:H7 in a kindergarten in Urawa in 1990. Positive immunodetection of Gb3 was significantly more frequent in female than in male distal and collecting renal tubules. To correlate this finding with a clinical outcome, a retrospective analysis of the predictors of renal failure in the 162 patients of two outbreaks in Japan was performed: one in Tochigi in 2002 and the other in Kagawa Prefecture in 2005. This study concludes renal failure, including HUS, was significantly associated with female sex, and the odds ratio was 4·06 compared to male patients in the two outbreaks. From 2006 to 2009 in Japan, the risk factor of HUS associated with STEC infection was analysed. The number of males and females and the proportion of females who developed HUS were calculated by age and year from 2006 to 2009. In 2006, 2007 and 2009 in adults aged >20 years, adult women were significantly more at risk of developing HUS in Japan.

scholarly journals Enhancement of Shiga Toxin Production in Enterohemorrhagic Escherichia coli Serotype O157:H7 by DNase Colicins

2007 ◽  
Vol 73 (23) ◽  
pp. 7582-7588 ◽  
Author(s):  
Hirono Toshima ◽  
Ayana Yoshimura ◽  
Kentaro Arikawa ◽  
Ayumi Hidaka ◽  
Jun Ogasawara ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Clinical Manifestations ◽  
Fold Increase ◽  
Toxin Production ◽  
Enterohemorrhagic Escherichia Coli ◽  
Mrna Levels ◽  
Rt Pcr ◽  
E Coli ◽  
Reverse Transcription Pcr

ABSTRACT Colicins are proteins produced by and active against several strains of Escherichia coli. Previously we reported that colicinogenic bacteria seemed beneficial in preventing the clinical manifestations of infectious disease caused by enterohemorrhagic E. coli O157 in humans. The inhibitory effects could be due to a decrease in O157 levels and/or pathogenicity. This study investigated the effects of colicinogenic E. coli on the production of Shiga toxin (Stx) by O157. Standard strains of colicinogenic bacteria carrying plasmids for each type of colicin (E3/5/8/9) were used for the study. The O157 strains were cultured in the presence of colicinogenic bacteria or extracted colicins. Compared with results for controls, DNase colicins (E8/9) facilitated an 8- to 64-fold increase in production of Stx2, while RNase colicins (E3/5) suppressed Stx production in only two strains. Stx prophages were induced in synchrony with Stx production. Semiquantitative real-time reverse transcription-PCR (RT-PCR) was then performed to examine SOS gene expression. The RT-PCR results clearly indicated a marked increase in mRNA levels of SOS reaction-associated genes after the addition of DNase colicins. We believe that Stx prophages are induced by the SOS response to DNA damage caused by DNase colicins, thus leading to higher Stx production. These findings suggest that while colicinogenic bacteria can be antagonistic to O157 infection, DNase colicins may enhance Stx production. Thus, colicinogenic flora is likely to be involved in the complex pathogenic pathways of O157 infection, and further investigation should be performed before the use of colicinogenic bacteria as an intervention method.

scholarly journals Transduction of Porcine Enteropathogenic Escherichia coli with a Derivative of a Shiga Toxin 2-Encoding Bacteriophage in a Porcine Ligated Ileal Loop System

2003 ◽  
Vol 69 (12) ◽  
pp. 7242-7247 ◽  
Author(s):  
István Tóth ◽  
Herbert Schmidt ◽  
Mohamed Dow ◽  
Anna Malik ◽  
Eric Oswald ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Prototype Strain ◽  
Epec Strain ◽  
Ileal Loop ◽  
E Coli ◽  
Shiga Toxin 2 ◽  
K 12

ABSTRACT In this study, we have investigated the ability of detoxified Shiga toxin (Stx)-converting bacteriophages Φ3538 (Δstx 2::cat) (H. Schmidt et al., Appl. Environ. Microbiol. 65:3855-3861, 1999) and H-19B::Tn10d-bla (D. W. Acheson et al., Infect. Immun. 66:4496-4498, 1998) to lysogenize enteropathogenic Escherichia coli (EPEC) strains in vivo. We were able to transduce the porcine EPEC strain 1390 (O45) withΦ 3538 (Δstx 2::cat) in porcine ligated ileal loops but not the human EPEC prototype strain E2348/69 (O127). Neither strain 1390 nor strain E2348/69 was lysogenized under these in vivo conditions when E. coli K-12 containing H-19B::Tn10d-bla was used as the stx1 phage donor. The repeated success in the in vivo transduction of an Stx2-encoding phage to a porcine EPEC strain in pig loops was in contrast to failures in the in vitro trials with these and other EPEC strains. These results indicate that in vivo conditions are more effective for transduction of Stx2-encoding phages than in vitro conditions.

Shiga Toxin-Producing Escherichia coli Infections in Germany†

1997 ◽  
Vol 60 (11) ◽  
pp. 1454-1457 ◽  
Author(s):  
HELGE KARCH ◽  
HANS-IKO HUPPERTZ ◽  
JOCHEN BOCKEMÜHL ◽  
HERBERT SCHMIDT ◽  
ANDREAS SCHWARZKOPF ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Blot Hybridization ◽  
Clinical Manifestations ◽  
Microbiological Analysis ◽  
E Coli ◽  
Shiga Toxin 2 ◽  
Stool Samples ◽  
A Prospective Study

A prospective study was carried out in collaboration with two children's hospitals in Würzburg, Germany to assess the incidence and clinical manifestations of infections due to Shiga toxin-producing Escherichia coli (STEC) in children. Between 1991 and 1995, stool samples from 2788 children with enteritis were investigated for the occurrence of STEC. STEC cultures from stools were screened using PCR with primers complementary to Shiga toxin 1(Stx1) and Shiga toxin 2 (Stx2) genes. PCR-positive samples were further subjected to colony blot hybridization and probe positive colonies were serotyped and analyzed for the presence of virulence genes. There was an increase in the incidence of STEC infections from 0.4% in 1991 to 2.8% in 1994. In 1995 the number of infections remained nearly unchanged (2.5%). Infection with STEC was associated with painful nonbloody diarrhea in most patients. Among the 35 patients in this study with stools containing STEC, only 9 (25.7%) had O157 colonies of which 3 (8.6%) were O157:H7 and 6 (17.1%) were sorbitol-fermenting O157:H−. In an additional study in 1994/l995, STEC etiology in 88 patients with HUS from Germany was confirmed in our laboratories by culture of STEC from stools, and in 20 additional HUS cases by serological analysis. Of the strains from stools of HUS patients, 78% belonged to serogroup O157. The most frequently isolated non-O157 serogroups were O26 and O111. These results demonstrate that when analyzing stools of patients with bloody diarrhea, HUS, or painful nonbloody diarrhea, the occurrence of non-O157:H7 strains should be considered when classical microbiological analysis fails to yield a standard enteric pathogen, such as Campylobacter. E. coli O157:H7, Salmonella. Shigella, or Yersinia.

scholarly journals Plasmids from Shiga Toxin-Producing Escherichia coli Strains with Rare Enterohemolysin Gene (ehxA) Subtypes Reveal Pathogenicity Potential and Display a Novel Evolutionary Path

2016 ◽  
Vol 82 (21) ◽  
pp. 6367-6377 ◽  
Author(s):  
Sandra C. Lorenz ◽  
Steven R. Monday ◽  
Maria Hoffmann ◽  
Markus Fischer ◽  
Julie A. Kase
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Sequence Data ◽  
Clinical Manifestations ◽  
Virulence Plasmid ◽  
Virulence Determinants ◽  
Content Type ◽  
E Coli ◽  
Subtype B ◽  
Evolutionary Relatedness

ABSTRACTMost Shiga toxin-producingEscherichia coli(STEC) strains associated with severe disease, such as hemolytic-uremic syndrome (HUS), carry large enterohemolysin-encoding (ehxA) plasmids, e.g., pO157 and pO103, that contribute to STEC clinical manifestations. SixehxAsubtypes (A through F) exist that phylogenetically cluster intoeae-positive (B, C, F), a mix ofeae-positive (E) andeae-negative (A), and a third, more distantly related, cluster ofeae-negative (D) STEC strains. While subtype B, C, and F plasmids share a number of virulence traits that are distinct from those of subtype A, sequence data have not been available for subtype D and E plasmids. Here, we determined and compared the genetic composition of four subtype D and two subtype E plasmids to establish their evolutionary relatedness amongehxAsubtypes and define their potential role in pathogenicity. We found that subtype D strains carry one exceptionally large plasmid (>200 kbp) that carries a variety of virulence genes that are associated with enterotoxigenic and enterohemorrhagicE. coli, which, quite possibly, enables these strains to cause disease despite being food isolates. Our data offer further support for the hypothesis that this subtype D plasmid represents a novel virulence plasmid, sharing very few genetic features with other plasmids; we conclude that these plasmids have evolved from a different evolutionary lineage than the plasmids carrying the otherehxAsubtypes. In contrast, the 50-kbp plasmids of subtype E (pO145), although isolated from HUS outbreak strains, carried only few virulence-associated determinants, suggesting that the clinical presentation of subtype E strains is largely a result of chromosomally encoded virulence factors.IMPORTANCEBacterial plasmids are known to be key agents of change in microbial populations, promoting the dissemination of various traits, such as drug resistance and virulence. This study determined the genetic makeup of virulence plasmids from rare enterohemolysin subtype D and E Shiga toxin-producingE. colistrains. We demonstrated thatehxAsubtype D plasmids represent a novelE. colivirulence plasmid, and although subtype D plasmids were derived from nonclinical isolates, they encoded a variety of virulence determinants that are associated with pathogenicE. coli. In contrast, subtype E plasmids, isolated from strains recovered from severely ill patients, carry only a few virulence determinants. The results of this study reemphasize the plasticity and vast diversity amongE. coliplasmids. This work demonstrates that, althoughE. colistrains of certain serogroups may not be frequently associated with disease, they should not be underestimated in protecting human health and food safety.

scholarly journals Escherichia coli O104:H4 outbreak--have we learnt a lesson from it?

2012 ◽  
Vol 59 (4) ◽  
Author(s):  
Sylwia K Bloch ◽  
Agnieszka Felczykowska ◽  
Bożena Nejman-Faleńczyk
Keyword(s):  
Escherichia Coli ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Shiga Toxin ◽  
Wide Spectrum ◽  
Clinical Manifestations ◽  
Significant Risk ◽  
Diagnostic Methods ◽  
Bacterial Strains ◽  
E Coli

Shiga toxin-producing Escherichia coli (STEC) strains belong to the group of pathogens that cause bloody diarrhea and hemorrhagic colitis with often severe complications. The main problem with human pathogenic E. coli strains, including STEC, is a wide spectrum of phenotypes and clinical manifestations. It is related to a variety of exchangeable genetic elements, like plasmids, bacteriophages, transposons and pathogenicity islands, that take part in horizontal gene transfer which influences creation of new dangerous bacterial strains. A good example of this phenomenon is a novel Shiga toxin-producing E. coli O104:H4 serotype that was associated with a widespread and severe foodborne disease outbreak in Germany in 2011. The O104:H4 strain was created by a number of horizontal gene transfer events between two distinct pathogens, resulting in the emergence of the new, atypical strain. That outbreak proved that also rare and unusual serotypes of STEC may be a significant risk factor and that the procedures recommended for STEC detection were not suitable to deal with this kind of pathogens. With respect to new combinations of chromosomal and extrachromosomal elements in susceptible bacterial hosts, epidemics and frequent human infections caused by STEC strains, we suggest that more attention should be paid to the development and improvement of diagnostic methods. It is difficult to determine STEC bacteria by general microbiological, biochemical and immunological assays, because strains can vary dramatically in their phenotypic and serotypic properties. It is postulated that standardized genetic tests, based on detection of features most frequently presented by STEC, particularly those located on easily exchangeable elements (such as Shiga toxin-encoding phages), can be more adequate for STEC detection.

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