Identification and Characterization of Heat‐Stable Enterotoxin II‐Producing <i>Escherichia coli</i> from Patients with Diarrhea

Okamoto, Keinosuke; Fujii, Y.; Akashi, Noriko; Hitotsubashi, Shunji; Kurazono, Hisao; Karasawa, Tadahiro; Takeda, Yoshifumi

doi:10.1111/j.1348-0421.1993.tb03230.x

Cited by 30 publications

(16 citation statements)

References 21 publications

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“…Previous phylogenetic investigations of ETEC using a variety of techniques have demonstrated similar results even though they were not placed within the context of the larger E. coli lineage. Thus, ETEC strains possessing the same CF-toxin genotypes often clustered together, suggesting that these strains had arisen by clonal expansion (33,42,43,51,59,61,64,65). However, in these same studies the CF-toxin genotypes were not strictly associated with phylogenetic clusters and closely related strains were also found to possess different CF-toxin profiles.…”

Section: Discussionmentioning

confidence: 81%

Phylogenetic Comparisons Reveal Multiple Acquisitions of the Toxin Genes by Enterotoxigenic Escherichia coli Strains of Different Evolutionary Lineages

et al. 2006

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Escherichia coli is a diverse bacterial species which is widely distributed in the environment but also exists as a commensal and pathogen of different host species. Human intestinal pathogenic E. coli causes over 160 million cases of diarrhea and an estimated 1 million deaths per year. The majority of deaths are attributable to one pathovar of E. coli, namely, enterotoxigenic E. coli. The pathogenesis of enterotoxigenic E. coli is dependent on the production of a colonization factor to promote adhesion to the intestinal epithelium and the elaboration of heat-labile or heat-stable toxins which induce a secretory diarrhea. Despite the high morbidity and mortality associated with enterotoxigenic E. coli infection, little is known of the genetic background of this global pathogen. Here we demonstrate by multilocus sequence typing that enterotoxigenic E. coli isolates are present in all phylogenetic lineages of E. coli, indicating that acquisition of the toxin genes may be sufficient to generate an enterotoxigenic E. coli strain. In addition, screening of diarrheal isolates for the presence of additional genes previously associated with the virulence of enterotoxigenic E. coli revealed that they were not abundant. These observations have significant implications for disease epidemiology and for the design of effective vaccines.

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Section: Discussionmentioning

confidence: 81%

Phylogenetic Comparisons Reveal Multiple Acquisitions of the Toxin Genes by Enterotoxigenic Escherichia coli Strains of Different Evolutionary Lineages

et al. 2006

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“…While the Stx2e that they encode is not linked to serious human disease (49), STa1 is encoded on a plasmid harbored in the human ETEC reference strain H10407 (28). ETEC strains that possess stb have been primarily isolated from animals, particularly pigs, but have been infrequently isolated from human clinical samples (5,6). However, it is not clear that STb is a contributing factor to the illness caused by the strains isolated from humans, such as strain C165-02 in this study, which also expresses stx 2d at a low level (4).…”

Section: Discussionmentioning

confidence: 99%

Hybrid Shiga Toxin-Producing and Enterotoxigenic Escherichia sp. Cryptic Lineage 1 Strain 7v Harbors a Hybrid Plasmid

Leonard

Mammel

Rasko

et al. 2016

Appl Environ Microbiol

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Hybrid isolates of Shiga toxin-producing Escherichia coli (STEC) and enterotoxigenic E. coli (ETEC) encoding heat-stable enterotoxin (ST) are being reported with increasing frequency from a variety of sources. However, information regarding the plasmids that these strains harbor is scarce. In this study, we sequence and characterize a plasmid, p7v, from the STEC/ETEC hybrid strain 7v. Whole-genome phylogenetic analyses of STEC/ETEC hybrid strains and prototype E. coli isolates of other pathotypes placed 7v in the Escherichia sp. cryptic lineage 1 (CL1) clade. The complete plasmid, p7v, was determined to be 229,275 bp and encodes putative virulence factors that are typically carried on STEC plasmids as well as those often carried on ETEC plasmids, indicating that the hybrid nature of the strain extends beyond merely encoding the two toxins. Plasmid p7v carries two copies of sta with identical sequences, which were discovered to be divergent from the sta sequences found in the prototype human ETEC strains. Using a nomenclature scheme based on a phylogeny constructed from sta and stb sequences, the sta encoded on p7v is designated STa4. In silico analysis determined that p7v also encodes the K88 fimbria, a colonization factor usually associated with porcine ETEC plasmids. The p7v sequence and the presence of plasmid-encoded virulence factors are compared to those of other STEC/ETEC CL1 hybrid genomes and reveal gene acquisition/loss at the strain level. In addition, the interrogation of 24 STEC/ETEC hybrid genomes for identification of plasmid replicons, colonization factors, Stx and ST subtypes, and other plasmid-encoded virulence genes highlights the diversity of these hybrid strains. IMPORTANCEHybrid Shiga toxin-producing Escherichia coli/enterotoxigenic Escherichia coli (STEC/ETEC) strains, which have been isolated from environmental, animal, and human clinical samples, may represent an emerging threat as food-borne pathogens. Characterization of these strains is important for assessing virulence potential, aiding in the development of pathogen detection methods, and understanding how the hybrid strains evolve to potentially have a greater impact on public health. This study represents, to our knowledge, both the first characterization of a closed plasmid sequence from a STEC/ETEC hybrid strain and the most comprehensive phylogenetic analysis of available STEC/ETEC hybrid genomes to date. The results demonstrate how the mobility of plasmid-associated virulence genes has resulted in the creation of a diverse plasmid repertoire within the STEC/ ETEC hybrid strains. Pathogenic Escherichia coli strains are categorized into pathotypes or pathovars (pathogenic variants) based on virulenceassociated genes whose expression contributes to particular disease symptoms in the human host (1). The virulence-associated genes that are unique to a pathotype have been used as molecular markers to define the pathotype of a given E. coli isolate. Two E. coli pathotypes that cause a significant burden of illness throughout ...

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“…STb is a 48 amino-acid peptide of 5.2 kDa mostly associated with porcine ETEC strains [16]. Nevertheless, some ETEC isolates from human origin where shown to possess the gene for this enterotoxin [17,18]. …”

Section: Enterotoxinsmentioning

confidence: 99%

Antibacterial and Antidiarrheal Activities of Plant Products against Enterotoxinogenic Escherichia coli

Dubreuil

2013

Toxins

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Enterotoxigenic Escherichia coli (ETEC) produces two types of enterotoxins: heat-labile (LT) and heat-stable (STa and STb). These molecules are involved in the induction of secretory diarrhea in animals including humans. This condition is currently treated using a fluid replacement therapy and antibiotics. This treatment is often not available to people in developing countries, and several die from the condition provoke by ETEC. Over the years, plants and plant extracts have been use as traditional medicine to treat various gastrointestinal ailments including diarrhea. Many of these plant products have been claimed to be active against diarrhea, however few have been extensively studied. The main objective of this review was to gather the scattered information on the antidiarrheal activities reported for various plant products on ETEC. This includes two major effects: (1) The inhibitory effect on bacterial growth or viability and (2) The interference with ETEC enterotoxins activity upon the intestinal epithelium. We will focus on plant products and extracts for which we have major indications of their biological activity against ETEC and their enterotoxins. Because Vibrio cholerae toxin (CT) is structurally, antigenically and mechanistically related to LT, it will also be discussed in this review.

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Identification and Characterization of Heat‐Stable Enterotoxin II‐Producing Escherichia coli from Patients with Diarrhea

Cited by 30 publications

References 21 publications

Phylogenetic Comparisons Reveal Multiple Acquisitions of the Toxin Genes by Enterotoxigenic Escherichia coli Strains of Different Evolutionary Lineages

Phylogenetic Comparisons Reveal Multiple Acquisitions of the Toxin Genes by Enterotoxigenic Escherichia coli Strains of Different Evolutionary Lineages

Hybrid Shiga Toxin-Producing and Enterotoxigenic Escherichia sp. Cryptic Lineage 1 Strain 7v Harbors a Hybrid Plasmid

Antibacterial and Antidiarrheal Activities of Plant Products against Enterotoxinogenic Escherichia coli

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