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 ◽  
...  

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.

2007 ◽  
Vol 74 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Alexander Mellmann ◽  
Shan Lu ◽  
Helge Karch ◽  
Jian-guo Xu ◽  
Dag Harmsen ◽  
...  

ABSTRACT Using colony blot hybridization with stx 2 and eae probes and agglutination in anti-O157 lipopolysaccharide serum, we isolated stx 2-positive and eae-positive sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157:NM (nonmotile) strains from initial stool specimens and stx-negative and eae-positive SF E. coli O157:NM strains from follow-up specimens (collected 3 to 8 days later) from three children. The stx-negative isolates from each patient shared with the corresponding stx 2-positive isolates fliC H7, non-stx virulence traits, and multilocus sequence types, which indicates that they arose from the stx 2-positive strains by loss of stx 2 during infection. Analysis of the integrity of the yecE gene, a possible stx phage integration site in EHEC O157, in the consecutive stx 2-positive and stx-negative isolates demonstrated that yecE was occupied in stx 2-positive but intact in stx-negative strains. It was possible to infect and lysogenize the stx-negative E. coli O157 strains in vitro using an stx 2-harboring bacteriophage from one of the SF EHEC O157:NM isolates. The acquisition of the stx 2-containing phage resulted in the occupation of yecE and production of biologically active Shiga toxin 2. We conclude that the yecE gene in SF E. coli O157:NM is a hot spot for excision and integration of Shiga toxin 2-encoding bacteriophages. SF EHEC O157:NM strains and their stx-negative derivatives thus represent a highly dynamic system that can convert in both directions by the loss and gain of stx 2-harboring phages. The ability to recycle stx 2, a critical virulence trait, makes SF E. coli O157:NM strains ephemeral EHEC that can exist as stx-negative variants during certain phases of their life cycle.


2021 ◽  
Vol 9 (11) ◽  
pp. 2374
Author(s):  
Xiangning Bai ◽  
Flemming Scheutz ◽  
Henrik Mellström Dahlgren ◽  
Ingela Hedenström ◽  
Cecilia Jernberg

Shiga toxin (Stx) is the key virulence factor in the Shiga Toxin-Producing Escherichia coli (STEC), which can cause diarrhea and hemorrhagic colitis with potential life-threatening complications. There are two major types of Stx: Stx1 and Stx2. Several Stx1/Stx2 subtypes have been identified in E. coli, varying in sequences, toxicity and host specificity. Here, we report a novel Stx2 subtype (designated Stx2m) from three clinical E. coli strains isolated from diarrheal patients and asymptomatic carriers in Sweden and Denmark. The Stx2m toxin was functional and exhibited cytotoxicity in vitro. The two Swedish Stx2m-producing strains belonged to the same serotype O148:H39 and Multilocus Sequencing Typing (MLST) Sequence Type (ST) 5825, while the Danish strain belonged to the O96:H19 serotype and ST99 type. Whole-genome sequencing (WGS) data analysis revealed that the three Stx2m-producing strains harbored additional virulence genes and the macrolide resistance gene mdf (A). Our findings expand the pool of Stx2 subtypes and highlight the clinical significance of emerging STEC variants. Given the clinical relevance of the Stx2m-producing strains, we propose to include Stx2m in epidemiological surveillance of STEC infections and clinical diagnosis.


2020 ◽  
Vol 152 ◽  
pp. 15667-15675
Author(s):  
Chakirath Folakè Arikè Salifou ◽  
Cyrille Boko ◽  
Isidore Houaga ◽  
Raoul Agossa ◽  
Isabelle Ogbankotan ◽  
...  

Objectives: The study aimed to search for E. coli O157 and non-O157 in milk, meat and faeces of cattle, sheep and pigs slaughtered in Cotonou. Methodology and Results: One hundred and Seventy-Five (175) samples including 25 meat, 25 faeces per species and 25 milk from cattle were analysed for E. coli O157; O26 and O111 and the virulence genes were identified by PCR. The SAS software (1998) and the bilateral Z test were used to calculate and compare the identification frequencies. E. coli O157 was identified in 4% of cattle faeces, 4% of sheep faeces, and 20% of beef and, in 20% of milk samples. E. coli O26 was identified in 12% of cattle faeces and, in 8% of beef samples. E. coli O111 was identified at frequencies of 8%, and 12% in faeces of sheep and pigs, respectively. The eae gene was detected in 4% of beef, ovine meat, milk, pig faeces and in sheep faeces. stx1 was detected in 8% of milk, and in 4% of bovine and sheep faeces. The strains possessing the gene were all of E. coli O157 with the exception of one from pig faeces identified as O111. Conclusions and application of findings: The presence of these serogroups of E. coli with virulence genes poses a real food safety problem in Benin. This study findings must be taken into account for risk assessment and management related to the consumption of food of animal origin. Keywords: Benin, E. coli O157, O26, O111, faeces, meat, milk


2000 ◽  
Vol 124 (2) ◽  
pp. 215-220 ◽  
Author(s):  
B. DECLUDT ◽  
P. BOUVET ◽  
P. MARIANI-KURKDJIAN ◽  
F. GRIMONT ◽  
P. A. D. GRIMONT ◽  
...  

We conducted a study to determine the incidence of haemolytic uraemic syndrome (HUS) in children in France and to assess the role of Shiga-toxin-producing Escherichia coli (STEC) infection in the aetiology of HUS. In collaboration with the Société de Néphrologie Pédiatrique we undertook a retrospective review of all cases of HUS hospitalized from January 1993 to March 1995 and a 1-year prospective study (April 1995–March 1996) of epidemiological and microbiological features of cases of HUS. The polymerase chain reaction (PCR) procedure was used to detect stx, eae, e-hlyA genes directly from case stool samples. Serum samples from cases were examined for antibodies to lipopolysaccharide (LPS) of 26 major STEC serogroups. Two hundred and eighty-six cases were reported. The average incidence per year was 0·7/105 children < 15 years and 1·8/105 children < 5 years. During the prospective study, 122/130 cases were examined for evidence of STEC infection using PCR and/or serological assays and 105 (86%) had evidence of STEC infection. Serum antibodies to E. coli O157 LPS were detected in 79 (67%) cases tested. In conclusion, this study showed that STEC infection is an important cause of HUS in children in France, with a high proportion related to the O157 serogroup.


2014 ◽  
Vol 77 (7) ◽  
pp. 1052-1061 ◽  
Author(s):  
ABEL B. EKIRI ◽  
DOUGLAS LANDBLOM ◽  
DAWN DOETKOTT ◽  
SUSAN OLET ◽  
WEILIN L. SHELVER ◽  
...  

Cattle are the main reservoirs for Shiga toxin–producing Escherichia coli (STEC) strains. E. coli O26, O45, O103, O111, O121, O145, and O157 are among the STEC serogroups that cause severe foodborne illness and have been declared as adulterants by the U.S. Department of Agriculture, Food Safety and Inspection Service. The objectives of this study were (i) to estimate the prevalence of non-O157 STEC and E. coli O157 in naturally infected beef cows and in steer calves at postweaning, during finishing, and at slaughter and (ii) to test non-O157 STEC isolates for the presence of virulence genes stx1, stx2, eaeA, and ehlyA. Samples were collected from study animals during multiple sampling periods and included fecal grabs, rectal swabs, and midline sponge samples. Laboratory culture, PCR, and multiplex PCR were performed to recover and identify E. coli and the virulence genes. The prevalence of non-O157 STEC (serogroups O26, O45, O103, O111, O121, O113, and O145) fecal shedding ranged from 8% (4 of 48 samples) to 39% (15 of 38 samples) in cows and 2% (1 of 47 samples) to 38% (9 of 24 samples) in steer calves. The prevalence of E. coli O157 fecal shedding ranged from 0% (0 of 38 samples) to 52% (25 of 48 samples) in cows and 2% (1 of 47 samples) to 31% (15 of 48 samples) in steer calves. In steer calves, the prevalence of non-O157 STEC and E. coli O157 was highest at postweaning, at 16% (15 of 96 samples) and 23% (22 of 96 samples), respectively. Among the 208 non-O157 STEC isolates, 79% (164 isolates) had stx1, 79% (165 isolates) had stx2, and 58% (121 isolates) had both stx1 and stx2 genes. The percentage of non-O157 STEC isolates encoding the eaeA gene was low; of the 165 isolates tested, 8 (5%) were positive for eaeA and 135 (82%) were positive for ehlyA. Findings from this study provide further evidence of non-O157 STEC shedding in beef cows and steer calves particularly at the stage of postweaning and before entry into the feedlot.


2014 ◽  
Vol 19 (17) ◽  
Author(s):  
I Friesema ◽  
K van der Zwaluw ◽  
T Schuurman ◽  
M Kooistra-Smid ◽  
E Franz ◽  
...  

The Shiga toxins of Shiga toxin-producing Escherichia coli (STEC) can be divided into Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2) with several sub-variants. Variant Stx2f is one of the latest described, but has been rarely associated with symptomatic human infections. In the enhanced STEC surveillance in the Netherlands, 198 STEC O157 cases and 351 STEC non-O157 cases, including 87 stx2f STEC isolates, were reported between 2008 and 2011. Most stx2f strains belonged to the serogroups O63:H6 (n=47, 54%), O113:H6 (n=12, 14%) and O125:H6 (n=12, 14%). Of the 87 stx2f isolates, 84 (97%) harboured the E. coli attaching and effacing (eae) gene, but not the enterohaemorrhagic E. coli haemolysin (hly) gene. Stx2f STEC infections show milder symptoms and a less severe clinical course than STEC O157 infections. Almost all infections with stx2f (n=83, 95%) occurred between June and December, compared to 170/198 (86%) of STEC O157 and 173/264 (66%) of other STEC non-O157. Stx2f STEC infections in the Netherlands are more common than anticipated, and form a distinct group within STEC with regard to virulence genes and the relatively mild disease.


1999 ◽  
Vol 65 (12) ◽  
pp. 5615-5618 ◽  
Author(s):  
Maite Muniesa ◽  
Francisco Lucena ◽  
Juan Jofre

ABSTRACT The behavior outside the gut of seeded Escherichia coliO157:H7, naturally occurring E. coli, somatic coliphages, bacteriophages infecting O157:H7, and Shiga toxin 2 (Stx2)-encoding bacteriophages was studied to determine whether the last persist in the environment more successfully than their host bacteria. The ratios between the numbers of E. coli and those of the different bacteriophages were clearly lower in river water than in sewage of the area, whereas the ratios between the numbers of the different phages were similar. In addition, the numbers of bacteria decreased between 2 and 3 log units in in situ survival experiments performed in river water, whereas the numbers of phages decreased between 1 and 2 log units. Chlorination and pasteurization treatments that reduced by approximately 4 log units the numbers of bacteria reduced by less than 1 log unit the numbers of bacteriophages. Thus, it can be concluded that Stx2-encoding phages persist longer than their host bacteria in the water environment and are more resistant than their host bacteria to chlorination and heat treatment.


2003 ◽  
Vol 71 (6) ◽  
pp. 3107-3115 ◽  
Author(s):  
Shantini D. Gamage ◽  
Jane E. Strasser ◽  
Claudia L. Chalk ◽  
Alison A. Weiss

ABSTRACT The food-borne pathogen, Escherichia coli O157:H7, has been associated with gastrointestinal disease and the life-threatening sequela hemolytic uremic syndrome. The genes for the virulence factor, Shiga toxin 2 (Stx2), in E. coli O157:H7 are encoded on a temperate bacteriophage under the regulation of the late gene promoter. Induction of the phage lytic cycle is required for toxin synthesis and release. We investigated the hypothesis that nonpathogenic E. coli could amplify Stx2 production if infected with the toxin-encoding phage. Toxin-encoding phage were incubated with E. coli that were either susceptible or resistant to the phage. The addition of phage to phage-susceptible bacteria resulted in up to 40-fold more toxin than a pure culture of lysogens, whereas the addition of phage to phage-resistant bacteria resulted in significantly reduced levels of toxin. Intestinal E. coli isolates incubated with Shiga toxin-encoding phage produced variable amounts of toxin. Of 37 isolates, 3 produced significantly more toxin than was present in the inoculum, and 1 fecal isolate appeared to inactivate the toxin. Toxin production in the intestine was assessed in a murine model. Fecal toxin recovery was significantly reduced when phage-resistant E. coli was present. These results suggest that the susceptibility of the intestinal flora to the Shiga toxin phage could exert either a protective or an antagonistic influence on the severity of disease by pathogens with phage-encoded Shiga toxin. Toxin production by intestinal flora may represent a novel strategy of pathogenesis.


2006 ◽  
Vol 69 (12) ◽  
pp. 3018-3020 ◽  
Author(s):  
M. J. ALAM ◽  
L. ZUREK

Cattle are an asymptomatic reservoir of Escherichia coli O157:H7, but the bacterial colonization and shedding patterns are poorly understood. The prevalence and shedding of this human pathogen have been reported to be seasonal with rates typically increasing during warm months. The objectives of this study were (i) to assess the prevalence of E. coli O157:H7 in feces of feedlot cattle in Kansas during summer, fall, and winter months, and (ii) to characterize E. coli O157:H7 by screening for virulence factors. Of 891 fecal samples collected, 82 (9.2%) were positive for E. coli O157:H7. No significant differences in prevalence were detected among summer, fall, and winter months. The highest monthly prevalence (18.1%) was detected in February. All tested isolates were positive for stx2 (Shiga toxin 2) and eaeA (intimin) genes; 14 isolates (12.8%) also carried stx1. Our results indicate the prevalence of E. coli O157:H7 in beef cattle feces is not necessarily season dependent.


2014 ◽  
Vol 618 ◽  
pp. 293-297 ◽  
Author(s):  
Yang Deng ◽  
Li Li Ji ◽  
Lin Li ◽  
Bing Li ◽  
Jian Yu Su

Escherichia coliO157,Psuedomonas aeruginosa,Salmonella,Vibrio parahaemolyticusandListeriaare important pathogens for human. With increased awareness in public health, development of a rapid, sensitive, cost-effective and easy-operating bacteriological detection is of the utmost importance and urgent necessity. In this study, we developed and applied a simple amplification kit based on loop-mediated isothermal amplification (LAMP) methods for rapid detection of various pathogens includingEscherichia coliO157,Psuedomonas aeruginosa,Salmonella,Vibrio parahaemolyticusandListeria, as well as related virulence. Nine targets, includingrfbE(E. coli-specific),stx1 (coding for Shiga toxin 1),stx2 (coding for Shiga toxin 2),oprI(P. aeruginosa–specific),invA(Salmonella-specific),hlyA(Listeria-specific),tlh(coding for thermolable haemolysin),tdh(coding for thermostable direct haemolysin) andtrh(coding for TDH-related haemolysin), were selected for identification forEscherichia coliO157,Psuedomonas aeruginosa,Salmonella,Vibrio parahaemolyticusandListeria, as well as related virulence.. Six primers, including outer primers, inner primers and loop primers, were specially designed for recognizing eight distinct sequences on the targets. Three solutions labeled A, B and C was included in the kit. The experiment were carried out in a total of 25 μl reaction mixture: solution A containing 1.6 μM (each) of the primers FIP and BIP, 0.2 μM (each) of the primers F3 and B3, 0.8 μM (each) of primers LF and LB; solution B containing 1.6 mM of deoxynucleoside triphosphates, 6 mM MgSO4, 1 M betain (Sigma, St. Louis, MO, USA), 1 X thermopol buffer (New England Biolabs, Ipswich, MA, USA); solution C containing BST polymerase. Twenty-two reference strains, including various species of gram-negative and-positive isolates, were included in this study to evaluate and optimize LAMP assays. Application of the optimized LAMP assays was performed on a total of 200 strains (with 40 strains for each species of the pahtogens). The optimal reaction condition was found to be 65°C for 45 min. Application of the kit assays were performed on various types of pathogens, the sensitivity for the 9 targets was found to be 100%; with a 100% specificity and positive predictive value (PPV) for all the 9 targets targets. In conclusion, the isothermal amplification kits were demonstrated to be useful and powerful tools for rapid differentiation of various pathogens (includingEscherichia coliO157,Psuedomonas aeruginosa,Salmonella,Vibrio parahaemolyticusandListeria), and undoubtedly, the rapidness, easiness and cost-effectiveness of LAMP assay will aid in the broad application of bacteriological detection of common pathogens.


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