Genes coding for Shiga-like toxin and heat-stabile enterotoxin in porcine strains of Escherichia coli

Meyer, Torsten; Karch, H

doi:10.1016/0378-1097(89)90353-4

Cited by 4 publications

(4 citation statements)

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“…The results of Southern blot analysis with probe 428-I further revealed that no hybridization signals occurred with the PCR products of SLT-II-producing E. coli C600 lysogenized with coliphage 933W (Fig. 4B, lane 3); porcine isolate E57 (lane 7), which produces a variant of SLT-II (18,19); and human 0157:H7 isolates 7279 and 4821 (lanes 4 and 5, respectively), which are thought to produce variants of SLT-II (11). When the blot was reused for hybridization with probe 428-Il, signals appeared only with the PCR products from SLT-II-producing E. coli C600 lysogenized with coliphage 933W (Fig.…”

Section: Resultsmentioning

confidence: 91%

“…Other verocytotoxigenic E. coli strains included five SLT-I-producing 026: Hl strains from children with diarrhea, five SLT-I producing 0111:Hstrains isolated from patients with hemolytic uremic syndrome (two strains) or hemorrhagic colitis (three strains). Porcine E. coli 0138:K81 strain E57, originally shown to be verocytotoxic by Konowalchuk et al (15), was recently described as producing a variant of SLT-II (19). E. coli 0139:K82:H1 strain 2013 was isolated from a pig with edema disease and also produces a variant of SLT-II (18).…”

Section: Methodsmentioning

confidence: 99%

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Single primer pair for amplifying segments of distinct Shiga-like-toxin genes by polymerase chain reaction

1989

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By using a single synthetic oligonucleotide primer pair in the polymerase chain reaction, we amplified specific Shiga-like-toxin (SLT) gene segments from DNAs of 20 clinical Escherichia coli isolates, irrespective of whether they produce SLT-I, SLT-II, or heretofore uncategorized SLTs. These segments were not detectable in any of 20 nontoxigenic E. coli strains. The primers deduced from a conserved region among SLT genes are so-called degenerate-sequence primers; i.e., they contain intentionally introduced sequence ambiguities to overcome minor sequence variations within different SLT genes. In direct gel hybridization with genomic DNA, both primers recognized SLT-I and SLT-II DNA sequences. Amplified sequences of target DNA obtained by polymerase chain reaction were visualized after gel electrophoresis by ethidium bromide staining, and definitive identification of the amplification product as an SLT gene segment was achieved by hybridization to SLT-I- and SLT-II-specific 20-base oligonucleotide probes complementary to a portion of the amplified sequences but not to the primers. The detecting oligonucleotide probes shared only 30% base homology and were shown to recognize specifically SLT-I or SLT-II sequences within genomic DNA. Moreover, they were used to distinguish whether the amplified sequence originated from SLT-I or SLT-II genes. The PCR system with the primers described here is a powerful technique to amplify SLT sequences in E. coli strains that produce serologically distinct SLTs and will facilitate identification of these pathogens, particularly among a multitude of nonpathogenic E. coli strains.

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Section: Resultsmentioning

confidence: 91%

Section: Methodsmentioning

confidence: 99%

Single primer pair for amplifying segments of distinct Shiga-like-toxin genes by polymerase chain reaction

1989

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“…Although SLTEC strains pathogenic to pigs often harbor genes that encode the production of adhesins (1,35,37) and enterotoxins (20,37), the O101 isolates described here were negative in PCR analysis for the genes for heat-stable and heat-labile enterotoxins I and did not produce the F107 fimbriae found in O139 strains that cause edema disease (1,35). In addition, other virulence characteristics of human SLTEC, such as the presence of the eaeA gene (38), positivity in the fluorescent actin staining test on HEp-2 cells (18), and production of the EHEC Hly (27), could not be detected.…”

Section: Discussionmentioning

confidence: 99%

“…Strains E-D43, E-D53, and E-D68 were of serotype O101:H Ϫ , strain E-D42 was of serotype O101:H14. Additional strains used for genetic analyses were E. coli lysogens C600 (H19J) and C600 (933W) and wild-type strains E57 (O138), E32511 (O157), EDL933 (O157), 76/5 (O143), HUS2/86 (O111), 4503/87 (O26), and WF96 (O7), which have been previously described (4,20). In addition, E. coli O139:H1 strain 2458 from a pig with edema disease was used in Southern hybridization experiments.…”

Section: Methodsmentioning

confidence: 99%

Clonal relatedness of Shiga-like toxin-producing Escherichia coli O101 strains of human and porcine origin

et al. 1995

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Shiga-like toxin (SLT)-producing Escherichia coli (SLTEC) O101 has recently been associated with hemorrhagic colitis and hemolytic-uremic syndrome in humans. In this study, SLTEC O101 strains from humans and pigs were characterized for clonal relatedness by nucleotide sequence analysis of their slt genes, DNA fingerprinting of genomic DNA, and determination of virulence factors. The slt genes of five E. coli O101 strains were cloned and sequenced. For all strains, the deduced amino acid sequences of the B subunits were identical to those of the SLT-IIe present in the classical SLTEC O139 strains that cause edema disease in pigs. The A subunit revealed more than 99% homology to that of SLT-IIe. DNA fingerprinting revealed a high degree of genetic relatedness between the human and porcine O101 isolates. None of the O101 strains investigated had virulence factors frequently found in porcine (F107 fimbriae or heat-stable or heat-labile enterotoxins) or human SLTEC strains (eaeA or enterohemorrhagic E. coli hemolysin). The absence of virulence factors typical of SLT-I-and SLT-II-producing E. coli together with the presence of SLT-IIe, a toxin previously seen only in porcine E. coli, suggests a new pathogenic mechanism for E. coli O101 infection of humans. For diagnostic purposes, we recommend the use of PCR primers and DNA probes complementary to slt-IIe to correctly identify such strains and to further evaluate their role in human diseases.on July 11, 2020 by guest http://jcm.asm.org/ Downloaded from 3176 FRANKE ET AL.

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Swine and cattle enterotoxigenic Escherichia coli - mediated diarrhea. Development of therapies based on inhibition of bacteria-host interactions

Mouricout

1991

Eur J Epidemiol

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Enterotoxigenic Escherichia coli (ETEC) frequently occurs in diarrheal disease afflicting domestic animals. In this paper is summarized the research carried out over the last decade on the two important determinants of virulence that plays a role in the development of the infection, namely the colonizing ability of the small intestine mediated by specific fimbrial adhesins acting as lectins and the production of enterotoxins. Recent progress in knowledge of the phenomenon led to alternative strategies of prevention and cure of enteric infection. Since bacterial recognition of mucosa surface receptors in an initial event in colonization, several approaches based on the competitive inhibition of ETEC adhesion have been developed. This review examines the following approaches: competitive colonization with non pathogenic strains, design of adhesin or toxin vaccines, receptor analog therapy and methods for in vivo suppression of virulence factors.

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Genes coding for Shiga-like toxin and heat-stabile enterotoxin in porcine strains of Escherichia coli

Cited by 4 publications

References 10 publications

Single primer pair for amplifying segments of distinct Shiga-like-toxin genes by polymerase chain reaction

Single primer pair for amplifying segments of distinct Shiga-like-toxin genes by polymerase chain reaction

Clonal relatedness of Shiga-like toxin-producing Escherichia coli O101 strains of human and porcine origin

Swine and cattle enterotoxigenic Escherichia coli - mediated diarrhea. Development of therapies based on inhibition of bacteria-host interactions

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