scholarly journals Localization of the Insertion Site and Pathotype Determination of the Locus of Enterocyte Effacement of Shiga Toxin-Producing Escherichia coli Strains

2004 ◽  
Vol 70 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Yolande Bertin ◽  
Karima Boukhors ◽  
Valerie Livrelli ◽  
Christine Martin
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Insertion Site ◽  
Pcr Amplification ◽  
Food Samples ◽  
Asymptomatic Children ◽  
Healthy Cattle ◽  
Sporadic Cases ◽  
Enterocyte Effacement ◽  
Great Genetic Diversity

ABSTRACT Of 220 Shiga toxin-producing Escherichia coli (STEC) strains collected in central France from healthy cattle, food samples, and asymptomatic children, 12 possessed the eae gene included in the locus of enterocyte effacement (LEE) pathogenicity island. Based on gene typing, we observed 7 different eae espA espB tir pathotypes among the 12 STEC strains and described the new espAβv variant. As previously observed, the O157 serogroup is associated with eaeγ, O26 is associated with eaeβ, and O103 is associated with eaeε. However, the unexpected eaeζ allele was detected in 5 of the 12 isolates. PCR amplification and pulsed-field gel electrophoresis using the I-CeuI endonuclease followed by Southern hybridization indicated that the LEE was inserted in the vicinity of the selC (three isolates), pheU (two isolates), or pheV (six isolates) tRNA gene. Six isolates harbored two or three of these tRNA loci altered by the insertion of integrase genes (CP4-int and/or int-phe), suggesting the insertion of additional foreign DNA fragments at these sites. In spite of great genetic diversity of LEE pathotypes and LEE insertion sites, bovine strains harbor alleles of LEE genes that are frequently found in clinical STEC strains isolated from outbreaks and sporadic cases around the world, underscoring the potential risk of the bovine strains on human health.

scholarly journals Prevalence and Characteristics of Shiga Toxin-Producing Escherichia coli from Healthy Cattle in Japan

2001 ◽  
Vol 67 (1) ◽  
pp. 484-489 ◽  
Author(s):  
Hideki Kobayashi ◽  
Jun Shimada ◽  
Muneo Nakazawa ◽  
Tetsuo Morozumi ◽  
Tarja Pohjanvirta ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Virulence Factor ◽  
Shiga Toxin ◽  
Animal Groups ◽  
E Coli ◽  
Healthy Cattle ◽  
Stool Samples ◽  
Enterocyte Effacement ◽  
Virulence Factor Genes

ABSTRACT The prevalence of Shiga toxin-producing Escherichia coli (STEC) in Japan was examined by using stool samples from 87 calves, 88 heifers, and 183 cows on 78 farms. As determined by screening with stx-PCR, the prevalence was 46% in calves, 66% in heifers, and 69% in cows; as determined by nestedstx-PCR, the prevalence was 100% in all animal groups. Of the 962 isolates picked by colony stx hybridization, 92 isolates from 54 farms were characterized to determine their O serogroups, virulence factor genes, and antimicrobial resistance. Of these 92 isolates, 74 (80%) could be classified into O serogroups; 50% of these 74 isolates belonged to O serogroups O8, O26, O84, O113, and O116 and 1 isolate belonged to O serogroup O157. Locus of enterocyte effacement genes were detected in 24% of the isolates, and enterohemorrhagic E. coli (EHEC) hlyA genes were detected in 72% of the isolates. Neither the bundle-forming pilus gene nor the enteropathogenic E. coli adherence factor plasmid was found. STEC strains with characteristics typical of isolates from human EHEC infections, which were regarded as potential EHEC strains, were present on 11.5% of the farms.

scholarly journals Shiga-toxigenic Escherichia coli in ready-to-eat food staffs: Prevalence and distribution of putative virulence factors

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Mohammad Hossein Sakhaie Shahreza ◽  
Ebrahim Rahimi ◽  
Hassan Momtaz
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Shiga Toxin ◽  
Raw Materials ◽  
Pcr Amplification ◽  
Food Samples ◽  
Public Health Issue ◽  
E Coli ◽  
Food Borne ◽  
The World

Lack of proper hygiene and using from low quality raw materials cause high presence of food-borne pathogens in ready to eat foods. Shiga toxin producing Escherichia coli is one of the most common cause of food-borne diseases in the world. The present research was done to study the prevalence and distribution of virulence factors in the STEC strains isolated from various types of ready to eat food samples. Seven-hundred and twenty food samples were collected and cultured. Isolated E. coli bacteria were approved another time using the 16S rRNA-based PCR amplification. Approved strains were subjected to multiplex PCR for identification of putative virulence factors. Twenty-six out of 720 food samples (5.20%) were positive for E. coli. Salad (15%), candy (12.50%) and barbecue (10%) were the most commonly contaminated. Prevalence of STEC strains was 2.63%. Prevalence of EHEC and AEEC subtypes were 36.84% and 52.63%, respectively. EHEC strains harbored all three stx1, eae and ehly genes. High presence of EHEC strains besides the considerable distribution of multiple virulence factors showed an important public health issue regarding the consumption of ready to eat foods.

scholarly journals Prevalence of theeaeA gene in verotoxigenicEscherichia colistrains from dairy cattle in Southwest Ontario

1996 ◽  
Vol 116 (1) ◽  
pp. 1-7 ◽  
Author(s):  
K. S. Sandhu ◽  
R. C. Clarke ◽  
K. McFadden ◽  
A. Brouwer ◽  
M. Louie ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Frequency ◽  
Strong Association ◽  
Pcr Amplification ◽  
Dairy Farms ◽  
Adult Cattle ◽  
Cattle Disease ◽  
Healthy Cattle ◽  
Random Survey ◽  
Amplification Procedure

SummaryThis study determined the prevalence of theeaeA gene and its relationship to serotype and type of verotoxin produced in a collection of 432 verotoxigenicEscherichia coli(VTEC) obtained from the faeces of healthy cows and calves in a systematic random survey involving 80 dairy farms in Southwest Ontario. A PCR amplification procedure involving primer pairs which target the conserved central region of the O157:H7eaeA. gene showed that 151 (35·2%) strains were positive for the eaeA gene. All isolates (9–21 for each O group) of O groups 5, 26, 69, 84, 103, 111, 145 and 157 were positive, whereas all isolates (7–34 for each O group) of O groups 113, 132, and 153 and serotype O156:NM (38 isolates) were negative foreaeA. Seventy-three percent of 130 isolates ofeaeA-positive serotypes produced VT1 only compared with 20% of 253 isolates ofeaeA-negative serotypes. We conclude that there is a strong association between certain O groups and theeaeA gene, that serotypes ofeaeA-positive and eaeA-negative VTEC implicated in human and cattle disease are present at high frequency in the faeces of healthy cattle, that VT1 is more frequently associated witheaeA-positive than witheaeA-negative serogroups, and that the eaeA gene is more frequently found in VTEC from calves compared with VTEC from adult cattle.

Outbreak of Shiga Toxin–Producing Escherichia coli (STEC) O104:H4 Infection in Germany Causes a Paradigm Shift with Regard to Human Pathogenicity of STEC Strains

2012 ◽  
Vol 75 (2) ◽  
pp. 408-418 ◽  
Author(s):  
LOTHAR BEUTIN ◽  
ANNETT MARTIN
Keyword(s):  
Escherichia Coli ◽  
Hemolytic Uremic Syndrome ◽  
Shiga Toxin ◽  
Outbreak Strain ◽  
Fenugreek Seeds ◽  
E Coli ◽  
Aggregative Adherence ◽  
Uremic Syndrome ◽  
Enterocyte Effacement ◽  
The Way

An outbreak that comprised 3,842 cases of human infections with enteroaggregative hemorrhagic Escherichia coli (EAHEC) O104:H4 occurred in Germany in May 2011. The high proportion of adults affected in this outbreak and the unusually high number of patients that developed hemolytic uremic syndrome makes this outbreak the most dramatic since enterohemorrhagic E. coli (EHEC) strains were first identified as agents of human disease. The characteristics of the outbreak strain, the way it spread among humans, and the clinical signs resulting from EAHEC infections have changed the way Shiga toxin–producing E. coli strains are regarded as human pathogens in general. EAHEC O104:H4 is an emerging E. coli pathotype that is endemic in Central Africa and has spread to Europe and Asia. EAHEC strains have evolved from enteroaggregative E. coli by uptake of a Shiga toxin 2a (Stx2a)–encoding bacteriophage. Except for Stx2a, no other EHEC-specific virulence markers including the locus of enterocyte effacement are present in EAHEC strains. EAHEC O104:H4 colonizes humans through aggregative adherence fimbrial pili encoded by the enteroaggregative E. coli plasmid. The aggregative adherence fimbrial colonization mechanism substitutes for the locus of enterocyte effacement functions for bacterial adherence and delivery of Stx2a into the human intestine, resulting clinically in hemolytic uremic syndrome. Humans are the only known natural reservoir known for EAHEC. In contrast, Shiga toxin–producing E. coli and EHEC are associated with animals as natural hosts. Contaminated sprouted fenugreek seeds were suspected as the primary vehicle of transmission of the EAHEC O104:H4 outbreak strain in Germany. During the outbreak, secondary transmission (human to human and human to food) was important. Epidemiological investigations revealed fenugreek seeds as the source of entry of EAHEC O104:H4 into the food chain; however, microbiological analysis of seeds for this pathogen produced negative results. The survival of EAHEC in seeds and the frequency of human carriers of EAHEC should be investigated for a better understanding of EAHEC transmission routes.

scholarly journals Toxins of Locus of Enterocyte Effacement-Negative Shiga Toxin-Producing Escherichia coli

Toxins ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 241 ◽  
Author(s):  
Maike Krause ◽  
Holger Barth ◽  
Herbert Schmidt
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Enterocyte Effacement

Simultaneous Enrichment of Shiga Toxin–Producing Escherichia coli O157 and O26 and Salmonella in Food Samples Using Universal Preenrichment Broth

2009 ◽  
Vol 72 (10) ◽  
pp. 2065-2070 ◽  
Author(s):  
MASASHI KANKI ◽  
KAZUKO SETO ◽  
JUNKO SAKATA ◽  
TETSUYA HARADA ◽  
YUKO KUMEDA
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Food Samples ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Significant Difference ◽  
Peptone Water ◽  
Radish Sprouts ◽  
Pork Samples ◽  
Better Than

Universal preenrichment broth (UPB) was compared with modified Escherichia coli broth with novobiocin (mEC+n) for enrichment of Shiga toxin–producing E. coli O157 and O26, and with buffered peptone water (BPW) for preenrichment of Salmonella enterica. Ten strains each of the three pathogens were inoculated into beef and radish sprouts following thermal, freezing, or no treatment. With regard to O157 and O26, UPB incubated at 42°C recovered significantly more cells from inoculated beef than UPB at 35°C and from radish sprout samples than UPB at 35°C and mEC+n. With regard to Salmonella, UPB incubated at 42°C was as effective as UPB at 35°C and BPW at recovering cells from beef and radish sprout samples. No significant difference was noted between the effectiveness of UPB at 42°C and UPB at 35°C or BPW in the recovery of Salmonella from 205 naturally contaminated poultry samples. By using UPB at 42°C, one O157:H7 strain was isolated from the mixed offal of 53 beef samples, 6 cattle offal samples, and 50 pork samples all contaminated naturally, with no pathogen inoculation. The present study found that UPB incubated at 42°C was as effective as, or better than, mEC+n for enrichment of O157 and O26 and comparable to BPW for preenrichment of Salmonella. These findings suggest that a great deal of labor, time, samples, and space may be saved if O157, O26, and Salmonella are enriched simultaneously with UPB at 42°C.

scholarly journals Genomically Informed Strain-Specific Recovery of Shiga Toxin–Producing Escherichia coli during Foodborne Illness Outbreak Investigations

2018 ◽  
Vol 82 (1) ◽  
pp. 39-44 ◽  
Author(s):  
BURTON W. BLAIS ◽  
KYLE TAPP ◽  
MARTINE DIXON ◽  
CATHERINE D. CARRILLO
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Shiga Toxin ◽  
Sequence Data ◽  
Food Samples ◽  
Foodborne Illness ◽  
Whole Genome Sequence ◽  
Source Attribution ◽  
Selective Enrichment ◽  
Food Testing

ABSTRACT Next-generation sequencing plays an important role in the characterization of clinical bacterial isolates for source attribution purposes during investigations of foodborne illness outbreaks. Once an illness cluster and a suspect food vehicle have been identified, food testing is initiated for confirmation and to determine the scope of a contamination event so that the implicated lots may be removed from the marketplace. For biochemically diverse families of pathogens such as Shiga toxin–producing Escherichia coli (STEC), the ability to detect specific strains may be hampered by the lack of a universal selective enrichment approach for their recovery against high levels of background microbiota. The availability of whole genome sequence data for a given outbreak STEC strain prior to commencement of food testing may provide food microbiologists an opportunity to customize selective enrichment techniques favoring the recovery of the outbreak strain. Here we demonstrate the advantages of using the publicly available ResFinder tool in the analysis of STEC model strains belonging to serotypes O111 and O157 to determine antimicrobial resistance traits that can be used in formulating strain-specific enrichment media to enhance recovery of these strains from microbiologically complex food samples. The improved recovery from ground beef of model STEC strains with various antimicrobial resistance profiles was demonstrated using three classes of antibiotics as selective agents, suggesting the universal applicability of this new approach in supporting foodborne illness investigations.

scholarly journals Whole-Genome Analysis of a Shiga Toxin-Producing Escherichia coli O103:H2 Strain Isolated from Cattle Feces

2020 ◽  
Vol 9 (45) ◽  
Author(s):  
Yujie Zhang ◽  
Yen-Te Liao ◽  
Vivian C. H. Wu
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Whole Genome Analysis ◽  
Content Type ◽  
Cattle Feces ◽  
Beef Products ◽  
Foodborne Outbreaks ◽  
Enterocyte Effacement

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) serotype O103 is one of the primary pathogenic contaminants of beef products, contributing to several foodborne outbreaks in recent years. Here, we report the whole-genome sequence of a STEC O103:H2 strain isolated from cattle feces that contains a locus of enterocyte effacement (LEE) pathogenicity island.

scholarly journals Detection of the Emerging Shiga Toxin-Producing Escherichia coli O26:H11/H−Sequence Type 29 (ST29) Clone in Human Patients and Healthy Cattle in Switzerland

2013 ◽  
Vol 79 (17) ◽  
pp. 5411-5413 ◽  
Author(s):  
Claudio Zweifel ◽  
Nicole Cernela ◽  
Roger Stephan
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Sequence Type ◽  
Gene Profile ◽  
Content Type ◽  
Plasmid Gene ◽  
Healthy Cattle

ABSTRACTShiga toxin-producingEscherichia coliO26:H11/H−strains showing the characteristics of the emerging human-pathogenic ST29 clone (stx2a+only,eae+, plasmid gene profilehlyA+etpD+) were detected from human patients and healthy cattle, indicating a possible reservoir. Sheep also appear to shed strains related to the new pathogenic clone O26:H11/H−(ST29,stx1a+only,eae+, plasmid gene profilehlyA+etpD+).

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