scholarly journals Characterization of Shiga Toxin-ProducingEscherichia coliIsolated from Ground Beef Collected in Different Socioeconomic Strata Markets in Buenos Aires, Argentina

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Patricia Llorente ◽  
Laura Barnech ◽  
Kinue Irino ◽  
María Valeria Rumi ◽  
Adriana Bentancor
Keyword(s):  
Shiga Toxin ◽  
Buenos Aires ◽  
Ground Beef ◽  
Contamination Level ◽  
Contamination Rate ◽  
E Coli ◽  
Virulence Markers ◽  
Route Of Transmission ◽  
Socioeconomic Strata

Consumption of raw/undercooked ground beef is the most common route of transmission of Shiga toxin-producingE. coli(STEC). The aim of the study was to determine the STEC contamination level of the ground beef samples collected in 36 markets of different socioeconomic strata in Buenos Aires, Argentina, and the characterization of the isolated strains. Ninety-one out of 252 (36.1%) samples werestx+. Fifty-seven STEC strains were recovered. Eleven STEC strains belonged to O157 serogroup, and 46 to non-O157 serogroups. Virulence markers of the 57 STEC werestx1, 5.3% (3/57);stx2, 86.0% (49/57);stx1/stx2, 8.8% (5/57);ehxA, 61.4% (35/57);eae, 26.3% (15/57);saa, 24.6% (14/57). Shiga toxin subtypes werestx2, 31.5% (17/54);stx2c-vhb, 24.1% (13/54);stx2c-vha, 20.4% (11/54);stx2/stx2c-vha, 14.8% (8/54);stx2/stx2c-vhb, 5.6% (3/54);stx2c-vha/vhb, 3.7% (2/54). Serotypes O178:H19 and O157:H7 were prevalent. Contamination rate of STEC in all strata was high, and the highest O157 contamination was observed at low strata at several sampling rounds. Persistence of STEC was not detected. Sixteen strains (28.1%) were resistant to ampicillin, streptomycin, amikacin, or tetracycline. The STEC contamination level of ground beef could vary according to the sociocultural characteristics of the population.

scholarly journals Presence and Characterization of Shiga Toxin-Producing Escherichia coli and Other Potentially Diarrheagenic E. coli Strains in Retail Meats

2010 ◽  
Vol 76 (6) ◽  
pp. 1709-1717 ◽  
Author(s):  
Xiaodong Xia ◽  
Jianghong Meng ◽  
Patrick F. McDermott ◽  
Sherry Ayers ◽  
Karen Blickenstaff ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Ground Beef ◽  
Vero Cells ◽  
E Coli ◽  
Retail Meats ◽  
Retail Meat ◽  
Human Infections ◽  
Shiga Toxin Genes

ABSTRACT To determine the presence of Shiga toxin-producing Escherichia coli (STEC) and other potentially diarrheagenic E. coli strains in retail meats, 7,258 E. coli isolates collected by the U.S. National Antimicrobial Resistance Monitoring System (NARMS) retail meat program from 2002 to 2007 were screened for Shiga toxin genes. In addition, 1,275 of the E. coli isolates recovered in 2006 were examined for virulence genes specific for other diarrheagenic E. coli strains. Seventeen isolates (16 from ground beef and 1 from a pork chop) were positive for stx genes, including 5 positive for both stx 1 and stx 2, 2 positive for stx 1, and 10 positive for stx 2. The 17 STEC strains belonged to 10 serotypes: O83:H8, O8:H16, O15:H16, O15:H17, O88:H38, ONT:H51, ONT:H2, ONT:H10, ONT:H7, and ONT:H46. None of the STEC isolates contained eae, whereas seven carried enterohemorrhagic E. coli (EHEC) hlyA. All except one STEC isolate exhibited toxic effects on Vero cells. DNA sequence analysis showed that the stx 2 genes from five STEC isolates encoded mucus-activatable Stx2d. Subtyping of the 17 STEC isolates by pulsed-field gel electrophoresis (PFGE) yielded 14 distinct restriction patterns. Among the 1,275 isolates from 2006, 11 atypical enteropathogenic E. coli (EPEC) isolates were identified in addition to 3 STEC isolates. This study demonstrated that retail meats, mainly ground beef, were contaminated with diverse STEC strains. The presence of atypical EPEC strains in retail meat is also of concern due to their potential to cause 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.

Characterization of Shiga toxin producing E. coli and O157 serotype E. coli isolated in France from healthy domestic cattle

2001 ◽  
Vol 63 (3) ◽  
pp. 217-223 ◽  
Author(s):  
François Rogerie ◽  
Armelle Marecat ◽  
Stéphanie Gambade ◽  
Francis Dupond ◽  
Pierre Beaubois ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
E Coli

Low Prevalence of Salmonella and Shiga Toxin–Producing Escherichia coli in Lymph Nodes of Australian Beef Cattle

2017 ◽  
Vol 80 (12) ◽  
pp. 2105-2111 ◽  
Author(s):  
Gavin Bailey ◽  
Long Huynh ◽  
Lachlan Govenlock ◽  
David Jordan ◽  
Ian Jenson
Keyword(s):  
Escherichia Coli ◽  
Lymph Nodes ◽  
Shiga Toxin ◽  
Limit Of Detection ◽  
Ground Beef ◽  
Plate Count ◽  
Salmonella Spp ◽  
Live Animal ◽  
E Coli ◽  
Low Prevalence

ABSTRACT Salmonella contamination of ground beef has been viewed as originating from the surface of carcasses. Recent studies have identified lymph nodes as a potential source of Salmonella contamination because these tissues play an active role in containment of pathogens in the live animal and because some lymph nodes are unavoidably present in manufacturing beef trimmings or primal cuts that may be incorporated into ground beef. A survey was conducted of the microbiological status of lymph nodes from Australian cattle at the time of slaughter to determine the prevalence of microbiological contamination. Sets of lymph nodes (n = 197), consisting of the superficial cervical (prescapular), prepectoral, axillary, presternal, popliteal, ischiatic, subiliac (precrural), coxalis, and iliofemoralis (deep inguinal), were collected from five geographically separated Australian abattoirs over a period of 14 months. Samples were tested for the presence of Salmonella spp. and Shiga toxin–producing Escherichia coli by BAX PCR assay. Aerobic plate count, E. coli, and coliforms were enumerated with a lower limit of detection of 80 CFU per node. The observed prevalence of Salmonella within peripheral lymph nodes was 0.48% (7 of 1,464). Two of the seven lymph nodes in which Salmonella organisms were detected came from the same animal. Grass-fed, grain-fed, and cull dairy cattle were all found to have detectable Salmonella in lymph nodes. All Salmonella detections occurred during cooler months of the year. No Shiga toxin–producing E. coli were detected. Aerobic microorganisms were detected above the limit of quantification in 3.2% of nodes (median count 2.24 log per node), and E. coli was detected in 0.8% of nodes (median count 3.05 log per node). The low prevalence of Salmonella and low concentration of aerobic microorganisms in Salmonella-positive lymph nodes of Australian cattle at the time of slaughter suggest that the likelihood of lymph nodes contributing significantly to the presence of Salmonella in ground beef is low.

scholarly journals Assessment of Shiga Toxin-Producing Escherichia coli Isolates from Wildlife Meat as Potential Pathogens for Humans

2009 ◽  
Vol 75 (20) ◽  
pp. 6462-6470 ◽  
Author(s):  
Angelika Miko ◽  
Karin Pries ◽  
Sabine Haby ◽  
Katja Steege ◽  
Nadine Albrecht ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Farm Animals ◽  
Clonal Lineage ◽  
E Coli ◽  
Virulence Markers ◽  
Potential Source ◽  
Human Illness ◽  
High Level ◽  
Game Animals

ABSTRACT A total of 140 Shiga toxin-producing Escherichia coli (STEC) strains from wildlife meat (deer, wild boar, and hare) isolated in Germany between 1998 and 2006 were characterized with respect to their serotypes and virulence markers associated with human pathogenicity. The strains grouped into 38 serotypes, but eight O groups (21, 146, 128, 113, 22, 88, 6, and 91) and four H types (21, 28, 2, and 8) accounted for 71.4% and 75.7% of all STEC strains from game, respectively. Eighteen of the serotypes, including enterohemorrhagic E. coli (EHEC) O26:[H11] and O103:H2, were previously found to be associated with human illness. Genes linked to high-level virulence for humans (stx 2, stx 2d, and eae) were present in 46 (32.8%) STEC strains from game. Fifty-four STEC isolates from game belonged to serotypes which are frequently found in human patients (O103:H2, O26:H11, O113:H21, O91:H21, O128:H2, O146:H21, and O146:H28). These 54 STEC isolates were compared with 101 STEC isolates belonging to the same serotypes isolated from farm animals, from their food products, and from human patients. Within a given serotype, most STEC strains were similar with respect to their stx genotypes and other virulence attributes, regardless of origin. The 155 STEC strains were analyzed for genetic similarity by XbaI pulsed-field gel electrophoresis. O103:H2, O26:H11, O113:H21, O128:H2, and O146:H28 STEC isolates from game were 85 to 100% similar to STEC isolates of the same strains from human patients. By multilocus sequence typing, game EHEC O103:H2 strains were attributed to a clonal lineage associated with hemorrhagic diseases in humans. The results from our study indicate that game animals represent a reservoir for and a potential source of human pathogenic STEC and EHEC strains.

Occurrence of Pathogens in Raw and Ready-to-Eat Meat and Poultry Products Collected from the Retail Marketplace in Edmonton, Alberta, Canada

2006 ◽  
Vol 69 (9) ◽  
pp. 2176-2182 ◽  
Author(s):  
V. M. BOHAYCHUK ◽  
G. E. GENSLER ◽  
R. K. KING ◽  
K. I. MANNINEN ◽  
O. SORENSEN ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Ground Beef ◽  
Fermented Sausage ◽  
E Coli ◽  
Poultry Products ◽  
Fermented Sausages ◽  
Roast Beef ◽  
Chicken Legs ◽  
Retail Products ◽  
Campylobacter Spp

A total of 800 meat and poultry products were purchased from the retail marketplace in Edmonton, Alberta, Canada. The products consisted of raw ground beef, chicken legs, pork chops, and ready-to-eat fermented sausage, roast beef, processed turkey breast, chicken wieners, and beef wieners. The samples were analyzed to determine the prevalence of Shiga toxin–producing Escherichia coli, Salmonella, Campylobacter spp., and Listeria monocytogenes. Shiga toxin–producing E. coli O22: H8 was found in one raw ground beef sample. Salmonella and Campylobacter were found in 30 and 62% of raw chicken legs, respectively. L. monocytogenes was found in 52% of raw ground beef, 34% of raw chicken legs, 24% of raw pork chops, 4% of fermented sausages, 3% of processed turkey breast, 5% of beef wieners, and 3% of chicken wieners. The occurrence of pathogens in this study is similar to that in retail products in many other international locales.

scholarly journals Characterization of a Shiga Toxin-Encoding Temperate Bacteriophage of Shigella sonnei

2001 ◽  
Vol 69 (12) ◽  
pp. 7588-7595 ◽  
Author(s):  
Eckhard Strauch ◽  
Rudi Lurz ◽  
Lothar Beutin
Keyword(s):  
Shiga Toxin ◽  
Regulatory Region ◽  
Shigella Sonnei ◽  
Shigella Dysenteriae ◽  
Nucleotide Sequencing ◽  
Temperate Bacteriophage ◽  
Cross Hybridization ◽  
E Coli ◽  
K 12

ABSTRACT A Shiga toxin (Stx)-encoding temperate bacteriophage ofShigella sonnei strain CB7888 was investigated for its morphology, DNA similarity, host range, and lysogenization inShigella and Escherichia coli strains. Phage 7888 formed plaques on a broad spectrum of Shigella strains belonging to different species and serotypes, including Stx-producingShigella dysenteriae type 1. With E. coli, only strains with rough lipopolysaccharide were sensitive to this phage. The phage integrated into the genome of nontoxigenic S. sonneiand laboratory E. coli K-12 strains, which became Stx positive upon lysogenization. Moreover, phage 7888 is capable of transducing chromosomal genes in E. coli K-12. The relationships of phage 7888 with the E. coli Stx1-producing phage H-19B and the E. coli Stx2-producing phage 933W were investigated by DNA cross-hybridization of phage genomes and by nucleotide sequencing of an 8,053-bp DNA region of the phage 7888 genome flanking the stx genes. By these methods, a high similarity was found between phages 7888 and 933W. Much less similarity was found between phages H-19B and 7888. As in the other Stx phages, a regulatory region involved in Q-dependent expression is found upstream of stxA and stxB (stx gene) in phage 7888. The morphology of phage 7888 was similar to that of phage 933W, which shows a hexagonal head and a short tail. Our findings demonstrate that stx genes are naturally transferable and are expressed in strains of S. sonnei, which points to the continuous evolution of human-pathogenic Shigella by horizontal gene transfer.

scholarly journals A New Immunoassay for Detecting All Subtypes of Shiga Toxins Produced by Shiga Toxin-Producing E. coli in Ground Beef

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0148092 ◽  
Author(s):  
Xiaohua He ◽  
Qiulian Kong ◽  
Stephanie Patfield ◽  
Craig Skinner ◽  
Reuven Rasooly
Keyword(s):  
Shiga Toxin ◽  
Ground Beef ◽  
Shiga Toxins ◽  
E Coli
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