scholarly journals Extended-Spectrum- -Lactamase-Producing Escherichia coli Isolate Possessing the Shiga Toxin Gene (stx1) Belonging to the O64 Serogroup Associated with Human Disease in India

2013 ◽  
Vol 51 (6) ◽  
pp. 2008-2009 ◽  
Author(s):  
T. K. Dutta ◽  
I. Warjri ◽  
P. Roychoudhury ◽  
H. Lalzampuia ◽  
I. Samanta ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Human Disease ◽  
Toxin Gene ◽  
Coli Isolate ◽  
Extended Spectrum

scholarly journals CTX-M-15 Extended-Spectrum β-Lactamase in a Shiga Toxin-Producing Escherichia coli Isolate of Serotype O111:H8

2011 ◽  
Vol 78 (4) ◽  
pp. 1308-1309 ◽  
Author(s):  
Charlotte Valat ◽  
Marisa Haenni ◽  
Estelle Saras ◽  
Frédéric Auvray ◽  
Karine Forest ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Content Type ◽  
Coli Isolate ◽  
E Coli ◽  
Extended Spectrum

ABSTRACTWe report the discovery of a CTX-M-15-producingEscherichia coli(STEC) of serogroup O111:H8, a major serotype responsible for human enterohemorrhagicEscherichia coli(EHEC) infections. In line with the recent CTX-M-15/O104:H4E. colioutbreak, these data may reflect an accelerating spread of resistance to expanded-spectrum cephalosporins within theE. colipopulation, including STEC isolates.

A report on the prevalence and the whole-genome sequence-based analysis of Shiga-toxin producing Escherichia coli isolated from the recto-anal junction of slaughter-age Irish sheep

2021 ◽  
Author(s):  
Siobhán C. McCarthy ◽  
Guerrino Macori ◽  
Gina Duggan ◽  
Catherine M. Burgess ◽  
Séamus Fanning ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Human Disease ◽  
Pathogenic Bacteria ◽  
Small Ruminants ◽  
Whole Genome Sequence ◽  
Health Concern ◽  
Toxin Gene ◽  
Whole Genome ◽  
Faecal Excretion

Shiga toxin-producing Escherichia coli (STEC) are a diverse group of pathogenic bacteria capable of causing serious human illness and serogroups O157 and O26 are frequently implicated in human disease. Ruminant hosts are the primary STEC reservoir and small ruminants are important contributors to STEC transmission. This study investigated the prevalence, serotypes and shedding dynamics of STEC, including the super-shedding of serogroups O157 and O26, in Irish sheep. Recto-anal mucosal swab samples (N=840) were collected over 24 months from two ovine slaughtering facilities. Samples were plated on selective agars and were quantitatively and qualitatively assessed via real-time PCR for Shiga-toxin prevalence and serogroup. A subset of STEC isolates (N=199) were selected for whole-genome sequencing and analysed in silico . In total, 704/840 (83.8%) swab samples were Shiga-toxin positive following RT-PCR screening, and 363/704 (51.6%) animals were subsequently culture positive for STEC. Five animals were shedding STEC O157 and three of these were identified as super-shedders. No STEC O26 was isolated. Post-hoc statistical analysis showed that younger animals are more likely to harbour STEC and STEC carriage is most prevalent during the summer months. Following sequencing, 178/199 genomes were confirmed as STEC. Thirty-five different serotypes were identified, fifteen of which were not yet reported in sheep. Serotype O91:H14 was the most frequently reported. Eight Shiga-toxin gene variants were reported, two stx 1 and six stx 2 , and three novel Shiga-toxin subunit combinations were observed. Variant stx 1c was the most prevalent, while many strains also harboured stx 2b . Importance Shiga toxin-producing Escherichia coli (STEC) are foodborne, zoonotic pathogens of significant public health concern. All STEC harbour stx , a critical virulence determinant, but it is not expressed in most serotypes. Sheep shed the pathogen via faecal excretion and are increasingly recognised as important contributors in the dissemination of STEC. In this study, we have found that there is high prevalence of STEC circulating within sheep and prevalence is related to animal age and seasonality. Further, sheep harbour a variety of non-O157 STEC, whose prevalence and contribution to human disease has been under investigated for many years. A variety of Stx variants were also observed, some of which are of high clinical importance.

scholarly journals Extended-Spectrum  -Lactamase-Producing Shiga Toxin Gene (stx1)-Positive Escherichia coli O26:H11: a New Concern

2005 ◽  
Vol 43 (3) ◽  
pp. 1072-1075 ◽  
Author(s):  
Y. Ishii ◽  
S. Kimura ◽  
J. Alba ◽  
K. Shiroto ◽  
M. Otsuka ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Toxin Gene ◽  
Extended Spectrum

Characteristics of Shiga Toxin–Producing Escherichia coli Isolated from Swiss Raw Milk Cheese within a 3-Year Monitoring Program

2010 ◽  
Vol 73 (1) ◽  
pp. 88-91 ◽  
Author(s):  
C. ZWEIFEL ◽  
N. GIEZENDANNER ◽  
S. CORTI ◽  
G. KRAUSE ◽  
L. BEUTIN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Monitoring Program ◽  
Raw Milk ◽  
Health Impact ◽  
Toxin Gene ◽  
Genes Encoding ◽  
Raw Milk Cheese ◽  
Human Infections ◽  
Hard Cheese

Food is an important vehicle for transmission of Shiga toxin–producing Escherichia coli (STEC). To assess the potential public health impact of STEC in Swiss raw milk cheese produced from cow's, goat's, and ewe's milk, 1,422 samples from semihard or hard cheese and 80 samples from soft cheese were examined for STEC, and isolated strains were further characterized. By PCR, STEC was detected after enrichment in 5.7% of the 1,502 raw milk cheese samples collected at the producer level. STEC-positive samples comprised 76 semihard, 8 soft, and 1 hard cheese. By colony hybridization, 29 STEC strains were isolated from 24 semihard and 5 soft cheeses. Thirteen of the 24 strains typeable with O antisera belonged to the serogroups O2, O22, and O91. More than half (58.6%) of the 29 strains belonged to O:H serotypes previously isolated from humans, and STEC O22:H8, O91:H10, O91:H21, and O174:H21 have also been identified as agents of hemolytic uremic syndrome. Typing of Shiga toxin genes showed that stx1 was only found in 2 strains, whereas 27 strains carried genes encoding for the Stx2 group, mainly stx2 and stx2vh-a/b. Production of Stx2 and Stx2vh-a/b subtypes might be an indicator for a severe outcome in patients. Nine strains harbored hlyA (enterohemorrhagic E. coli hemolysin), whereas none tested positive for eae (intimin). Consequently, semihard and hard raw milk cheese may be a potential source of STEC, and a notable proportion of the isolated non-O157 STEC strains belonged to serotypes or harbored Shiga toxin gene variants associated with human infections.

scholarly journals Comparison between human and animal isolates of Shiga toxin-producing Escherichia coli O157 from Australia

2002 ◽  
Vol 128 (3) ◽  
pp. 357-362 ◽  
Author(s):  
N. FEGAN ◽  
P. DESMARCHELIER
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Human Infection ◽  
Pulsed Field Gel Electrophoresis ◽  
Toxin Gene ◽  
Escherichia Coli O157 ◽  
Animal Population ◽  
E Coli ◽  
Virulence Markers ◽  
Animal Isolates

There is very little human disease associated with enterohaemorrhagic Escherichia coli O157 in Australia even though these organisms are present in the animal population. A group of Australian isolates of E. coli O157:H7 and O157:H- from human and animal sources were tested for the presence of virulence markers and compared by XbaI DNA macrorestriction analysis using pulsed-field gel electrophoresis (PFGE). Each of 102 isolates tested contained the gene eae which encodes the E. coli attaching and effacing factor and all but one carried the enterohaemolysin gene, ehxA, found on the EHEC plasmid. The most common Shiga toxin gene carried was stx2c, either alone (16%) or in combination with stx1 (74%) or stx2 (3%). PFGE grouped the isolates based on H serotype and some clusters were source specific. Australian E. coli O157:H7 and H- isolates from human, animal and meat sources carry all the virulence markers associated with EHEC disease in humans therefore other factors must be responsible for the low rates of human infection in Australia.

scholarly journals Molecular analysis of Escherichia coli O157 strains isolated from cattle and pigs by the use of PCR and pulsed-field gel electrophoresis methods

2012 ◽  
Vol 47 (No. 6) ◽  
pp. 149-158 ◽  
Author(s):  
J. Osek ◽  
P. Gallien
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Genetic Relatedness ◽  
Rflp Analysis ◽  
Toxin Gene ◽  
Escherichia Coli O157 ◽  
Chromosomal Dna ◽  
E Coli ◽  
Shiga Toxin Genes ◽  
Porcine Origin

Fourteen Escherichia coli O157 strains isolated from cattle and pigs in Poland and in Germany were investigated, using PCR, for the genetic markers associated with Shiga toxin-producing E. coli (STEC). Only two strains, both of cattle origin, were positive for the fliC (H7) gene and could be classified as O157 : H7. Nine isolates had stx shiga toxin genes, either stx1 (1 strain), stx2 (4 isolates) or both (4 strains). The stx2-carrying samples were further subtyped by PCR for the stx2c, stx2d, and stx2e toxin variants. It was shown that all but one stx2-positive bacteria possessed the stx2c Shiga toxin gene type and one stx2 STEC isolate had the stx2d virulence factor sub-type. The eaeA (intimin) gene was found in 9 strains (8 isolates from cattle and one strain from pigs); all of them harboured the genetic marker characteristic of the gamma intimin variant. The translocated intimin receptor (tir) gene was detected in 7 isolates tested and among them only one tir-positive strain was recovered from pigs. The ehly E. coli enterohemolysin gene was amplified in all but one strains obtained from cattle and only in one isolate of porcine origin. The genetic relatedness of the analysed E. coli O157 strains was examined by restriction fragment length polymorphism (RFLP) of chromosomal DNA digested with XbaI. Two distinct but related RFLP pattern clusters were observed: one with 9 strains (8 isolates of bovine origin and one strain obtained from pigs) and the other one comprises the remaining 5 E. coli isolates (4 of porcine origin and one strain recovered from cattle). The results suggest that pigs, besides cattle, may be a reservoir of E. coli O157 strains potentially pathogenic to humans. Moreover, epidemiologically unrelated isolates of the O157 serogroup, recovered from different animal species, showed a clonal relationship as demonstrated by the RFLP analysis.

Detection of cytolethal distending toxin and other virulent factors in Escherichia coli samples from animal livestock, retail foods and gastroenteritis human cases in Qatar

2020 ◽  
Author(s):  
Adriana Morales Gómez ◽  
Nilda N. Valenzuela ◽  
Kenlyn E. Peters ◽  
Ahmed Salem ◽  
Ali Sultan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Food Products ◽  
Cross Sectional Study ◽  
Toxin Gene ◽  
Cytolethal Distending Toxin ◽  
Cross Sectional ◽  
E Coli ◽  
Polymerase Chain ◽  
Retail Food

Cytolethal distending toxin (CDT) is a heterotrimeric AB-type genotoxin produced by several clinically important bacterial pathogens. To better understand the risk of CDT within the food supply and human gastroenteritis patients in Qatar, we investigated the frequency of the CDT gene (cdtB) among Escherichia coli (E. coli) strains recovered from food products, animal livestock, and human gastroenteritis patients. In this cross-sectional study, E. coli isolates were screened for cdtB using polymerase chain reaction (PCR). cdtB positive strains were further examined for E. coli cdtB gene types (cdt I, cdt II, cdt III, cdt IV and cdtV), serotypes O157: H7, and non-O157 Shiga toxin-producing E. coli O26, O45, O103, O111, O121, and O145. Screening for other virulent factors, stx (Shiga toxin gene) and eae (gene that encodes intimin) genes were also performed. The cdtB gene was detected in E. coli isolates sourced from all three groups; animal livestock (17%), retail foods (8%), and human gastroenteritis patients (3%). Although the incidence of cdtB gene harboring E. coli is relatively low among gastroenteritis patients, there is still a risk of infection from animal reservoirs as well as retail food products. Among the three groups, E. coli isolates from humans had the lowest occurrence of cdtB, stx, eae, and O157: H7. Furthermore, we advise implementing monitoring at the food production and preparation level.

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