Prevalence, Characterization, and Genotypic Analysis of Escherichia coli O157:H7/NM fromSelected Beef Exporting Abattoirs of Argentina

2010 ◽  
Vol 73 (4) ◽  
pp. 649-656 ◽  
Author(s):  
M. O. MASANA ◽  
G. A. LEOTTA ◽  
L. L. DEL CASTILLO ◽  
B. A. D'ASTEK ◽  
P. M. PALLADINO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Phage Type ◽  
Escherichia Coli O157 ◽  
Phage Types ◽  
Clonal Relatedness ◽  
Genotypic Analysis ◽  
Shiga Toxin 2 ◽  
Uremic Syndrome ◽  
Fecal Content

In Argentina, Escherichia coli O157:H7/NM (STEC O157) is the prevalent serotype associated with hemolytic uremic syndrome (HUS), which is endemic in the country with more than 400 cases per year. In order to estimate the prevalence and characteristics of STEC O157 in beef cattle at slaughter, a survey of 1,622 fecal and carcass samples was conducted in nine beef exporting abattoirs from November 2006 to April 2008. A total of 54 samples were found positive for STEC O157, with an average prevalence of 4.1% in fecal content and 2.6% in carcasses. Calves and heifers presented higher percentages of prevalence in feces, 10.5 and 8.5%, respectively. All STEC O157 isolates harbored stx2 (Shiga toxin 2), eae (intimin), ehxA (enterohemolysin), and fliCH7 (H7 flagellin) genes, while stx1 (Shiga toxin 1) was present in 16.7% of the strains. The prevalent (56%) stx genotype identified was stx2 combined with variant stx2c (vh-a), the combination of which is also prevalent (>90%) in STEC O157 post–enteric HUS cases in Argentina. The clonal relatedness of STEC O157 strains was established by phage typing and pulsed-field gel electrophoresis (PFGE). The 54 STEC isolates were categorized into 12 different phage types and in 29 XbaI-PFGE patterns distributed in 27 different lots. STEC O157 strains isolated from 5 of 21 carcasses were identical by PFGE (100% similarity) to strains of the fecal content of the same or a contiguous bovine in the lot. Five phage type–PFGE–stx profiles of 10 strains isolated in this study matched with the profiles of the strains recovered from 18 of 122 HUS cases that occurred in the same period.

scholarly journals Cattle Can Be a Reservoir of Sorbitol-Fermenting Shiga Toxin-Producing Escherichia coli O157:H−Strains and a Source of Human Diseases

2000 ◽  
Vol 38 (9) ◽  
pp. 3470-3473 ◽  
Author(s):  
Martina Bielaszewska ◽  
Herbert Schmidt ◽  
Almut Liesegang ◽  
Rita Prager ◽  
Wolfgang Rabsch ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Immunomagnetic Separation ◽  
Human Diseases ◽  
Escherichia Coli O157 ◽  
Separation Procedure ◽  
The Czech Republic ◽  
Clonal Relatedness ◽  
Uremic Syndrome ◽  
Genotypic Characteristics

Using the immunomagnetic separation procedure, we isolated sorbitol-fermenting (SF) Shiga toxin-producing Escherichia coli (STEC) O157:H− strains from two patients, one with hemolytic-uremic syndrome and the other with diarrhea, and from a dairy cow epidemiologically associated with the patients. The phenotypic and genotypic characteristics of all isolates were identical or closely related. Moreover, the bovine isolate showed a clonal relatedness to SF STEC O157:H− strains isolated from patients in Germany and the Czech Republic from 1988 to 1998. This is the first evidence that cattle can be a reservoir of SF STEC O157:H− and a source of human diseases.

How Does Escherichia coli O157:H7 Testing in Meat Compare with What We Are Seeing Clinically?

2000 ◽  
Vol 63 (6) ◽  
pp. 819-821 ◽  
Author(s):  
DAVID W. K. ACHESON
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Shiga Toxin ◽  
Food Supply ◽  
The United States ◽  
Escherichia Coli O157 ◽  
Current Policy ◽  
E Coli ◽  
Different Types ◽  
Uremic Syndrome

Escherichia coli O157:H7 is but one of a group of Shiga toxin-producing E. coli (STEC) that cause both intestinal disease such as bloody and nonbloody diarrhea and serious complications like hemolytic uremic syndrome (HUS). While E. coli O157: H7 is the most renowned STEC, over 200 different types of STEC have been documented in meat and animals, at least 60 of which have been linked with human disease. A number of studies have suggested that non-O157 STEC are associated with clinical disease, and non-O157 STEC are present in the food supply. Non-O157 STEC, such as O111 have caused large outbreaks and HUS in the United States and other countries. The current policy in the United States is to examine ground beef for O157:H7 only, but restricting the focus to O157 will miss other important human STEC pathogens.

Distinctiveness of the genomic sequence of Shiga toxin 2-converting phage isolated from Escherichia coli O157:H7 Okayama strain as compared to other Shiga toxin 2-converting phages

Gene ◽  
2003 ◽  
Vol 309 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Toshio Sato ◽  
Takeshi Shimizu ◽  
Masahisa Watarai ◽  
Midori Kobayashi ◽  
Shigeyuki Kano ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Genomic Sequence ◽  
Escherichia Coli O157 ◽  
Shiga Toxin 2

scholarly journals Effects of Antibiotics on Shiga Toxin 2 Production and Bacteriophage Induction by Epidemic Escherichia coli O104:H4 Strain

2012 ◽  
Vol 56 (6) ◽  
pp. 3277-3282 ◽  
Author(s):  
Martina Bielaszewska ◽  
Evgeny A. Idelevich ◽  
Wenlan Zhang ◽  
Andreas Bauwens ◽  
Frieder Schaumburg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Therapy ◽  
Shiga Toxin ◽  
The Other ◽  
Emerging Pathogen ◽  
Outbreak Strain ◽  
Content Type ◽  
Shiga Toxin 2 ◽  
Uremic Syndrome

ABSTRACTThe role of antibiotics in treatment of enterohemorrhagicEscherichia coli(EHEC) infections is controversial because of concerns about triggering hemolytic-uremic syndrome (HUS) by increasing Shiga toxin (Stx) production. During the recent large EHEC O104:H4 outbreak, antibiotic therapy was indicated for some patients. We tested a diverse panel of antibiotics to which the outbreak strain is susceptible to interrogate the effects of subinhibitory antibiotic concentrations on induction ofstx2-harboring bacteriophages,stx2transcription, and Stx2 production in this emerging pathogen. Ciprofloxacin significantly increasedstx2-harboring phage induction and Stx2 production in outbreak isolates (Pvalues of <0.001 to <0.05), while fosfomycin, gentamicin, and kanamycin insignificantly influenced them (P> 0.1) and chloramphenicol, meropenem, azithromycin, rifaximin, and tigecycline significantly decreased them (P≤ 0.05). Ciprofloxacin and chloramphenicol significantly upregulated and downregulatedstx2transcription, respectively (P< 0.01); the other antibiotics had insignificant effects (P> 0.1). Meropenem, azithromycin, and rifaximin, which were used for necessary therapeutic or prophylactic interventions during the EHEC O104:H4 outbreak, as well as tigecycline, neither inducedstx2-harboring phages nor increasedstx2transcription or Stx2 production in the outbreak strain. These antibiotics might represent therapeutic options for patients with EHEC O104:H4 infection if antibiotic treatment is inevitable. We await further analysis of the epidemic to determine if usage of these agents was associated with an altered risk of developing HUS.

scholarly journals Enhanced Virulence of the Escherichia coli O157:H7 Spinach-Associated Outbreak Strain in Two Animal Models Is Associated with Higher Levels of Stx2 Production after Induction with Ciprofloxacin

2014 ◽  
Vol 82 (12) ◽  
pp. 4968-4977 ◽  
Author(s):  
T. Zangari ◽  
A. R. Melton-Celsa ◽  
A. Panda ◽  
M. A. Smith ◽  
I. Tatarov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Animal Models ◽  
Shiga Toxin ◽  
Hemorrhagic Colitis ◽  
Escherichia Coli O157 ◽  
Outbreak Strain ◽  
Content Type ◽  
Intestinal Pathology ◽  
Phage Dna ◽  
Uremic Syndrome

ABSTRACTShiga toxin (Stx)-producingEscherichia coli(STEC) causes hemorrhagic colitis and the hemolytic-uremic syndrome (HUS). STEC strains may produce Stx1a and/or Stx2a or variants of either toxin. A 2006 spinach-associated outbreak of STEC O157:H7 resulted in higher hospitalization and HUS rates than previous STEC outbreaks. The spinach isolate, strain K3995, contains bothstx2aandstx2c. We hypothesized that the enhanced virulence of K3995 reflects the combination ofstx2alleles (carried on lysogenic phages) and/or the amount of Stx2 made by that strain. We compared the virulence of K3995 to those of other O157:H7 isolates and an isogenic Stx2 mutant in rabbits and mice. We also measured the relative levels of Stx2 produced from those strains with or without induction of thestx-carrying phage. Some rabbits infected with K3995 exhibited intestinal pathology and succumbed to infection, while none of those infected with O157:H7 strain 2812 (Stx1a+Stx2a+) died or showed pathological signs. Rabbits infected with the isogenic Stx2a mutant K3995stx2a::catwere not colonized as well as those infected with K3995 and exhibited no signs of disease. In the streptomycin-treated mouse model, more animals infected with K3995 died than did those infected with O157:H7 strain 86-24 (Stx2a+). Additionally, K3995 produced higher levels of total Stx2 and toxin phage DNA in cultures after phage induction than did 86-24. Our results demonstrate the greater virulence of K3995 compared to other O157:H7 strains in rabbits and mice. We conclude that this enhanced virulence is linked to higher levels of Stx2 expression as a consequence of increased phage induction.

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