Salt at concentrations relevant to meat processing enhances Shiga toxin 2 production in Escherichia coli O157:H7

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.

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Enterohemorrhagic Escherichia coli O157 subclade 8b strains in Chiba Prefecture, Japan, produced larger amounts of Shiga toxin 2 than strains in subclade 8a and other clades

PLoS ONE ◽

10.1371/journal.pone.0191834 ◽

2018 ◽

Vol 13 (1) ◽

pp. e0191834 ◽

Cited By ~ 2

Author(s):

Shinichiro Hirai ◽

Eiji Yokoyama ◽

Taku Wakui ◽

Taichiro Ishige ◽

Masaki Nakamura

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Enterohemorrhagic Escherichia Coli ◽

Escherichia Coli O157 ◽

Chiba Prefecture ◽

Shiga Toxin 2

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Vaccination of pregnant cows with EspA, EspB, γ-intimin, and Shiga toxin 2 proteins from Escherichia coli O157:H7 induces high levels of specific colostral antibodies that are transferred to newborn calves

Journal of Dairy Science ◽

10.3168/jds.2011-5093 ◽

2012 ◽

Vol 95 (6) ◽

pp. 3318-3326 ◽

Cited By ~ 26

Author(s):

B.C. Rabinovitz ◽

E. Gerhardt ◽

C. Tironi Farinati ◽

A. Abdala ◽

R. Galarza ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Escherichia Coli O157 ◽

Shiga Toxin 2 ◽

Newborn Calves

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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 ◽

10.1016/s0378-1119(03)00487-6 ◽

2003 ◽

Vol 309 (1) ◽

pp. 35-48 ◽

Cited By ~ 28

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

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Efficacy of Urtoxazumab (TMA-15 Humanized Monoclonal Antibody Specific for Shiga Toxin 2) Against Post-Diarrheal Neurological Sequelae Caused by Escherichia coli O157:H7 Infection in the Neonatal Gnotobiotic Piglet Model

Toxins ◽

10.3390/toxins9020049 ◽

2017 ◽

Vol 9 (2) ◽

pp. 49 ◽

Cited By ~ 6

Author(s):

Rodney Moxley ◽

David Francis ◽

Mizuho Tamura ◽

David Marx ◽

Kristina Santiago-Mateo ◽

...

Keyword(s):

Escherichia Coli ◽

Monoclonal Antibody ◽

Shiga Toxin ◽

Escherichia Coli O157 ◽

Neurological Sequelae ◽

Humanized Monoclonal Antibody ◽

Shiga Toxin 2 ◽

Gnotobiotic Piglet

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Seasonal Prevalence of Escherichia coli O157:H7 in Beef Cattle Feces†

Journal of Food Protection ◽

10.4315/0362-028x-69.12.3018 ◽

2006 ◽

Vol 69 (12) ◽

pp. 3018-3020 ◽

Cited By ~ 33

Author(s):

M. J. ALAM ◽

L. ZUREK

Keyword(s):

Escherichia Coli ◽

Beef Cattle ◽

Shiga Toxin ◽

Bacterial Colonization ◽

Feedlot Cattle ◽

Escherichia Coli O157 ◽

Human Pathogen ◽

E Coli ◽

Cattle Feces ◽

Shiga Toxin 2

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.

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Reactivation of Insertionally Inactivated Shiga Toxin 2 Genes of Escherichia coli O157:H7 Caused by Nonreplicative Transposition of the Insertion Sequence

Applied and Environmental Microbiology ◽

10.1128/aem.66.3.1133-1138.2000 ◽

2000 ◽

Vol 66 (3) ◽

pp. 1133-1138 ◽

Cited By ~ 11

Author(s):

Masahiro Kusumoto ◽

Yoshiaki Nishiya ◽

Yoshihisa Kawamura

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Insertion Sequence ◽

Pcr Amplification ◽

Direct Repeat ◽

Toxin Gene ◽

Escherichia Coli O157 ◽

Wild Type ◽

In The Wild ◽

Shiga Toxin 2

ABSTRACT IS1203v is an insertion sequence which has been found in inactivated Shiga toxin 2 genes of Escherichia coliO157:H7. We analyzed the transpositional mechanism of IS1203v in order to investigate whether the Shiga toxin 2 genes inactivated by IS1203v could revert to the wild type. When the transposase activity of IS1203v was enhanced by artificial frameshifting, IS1203v was obviously excised from the Shiga toxin 2 gene in a circular form. The IS1203v circle consisted of the entire IS1203v, but an extra 3-bp sequence (ATC) intervened between the 5′ and 3′ ends of IS1203v. The extra 3-bp sequence was identical to a direct repeat which was probably generated upon insertion. Moreover, we detected the Shiga toxin 2 gene with a precise excision of IS1203v. In the wild-type situation, the transposition products of IS1203v could be observed by PCR amplification. These results show that IS1203v can transpose in a nonreplicative manner and that the Shiga toxin gene inactivated by this insertion sequence can revert to the wild type.

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