Prolonged Fecal Excretion of Verotoxin-Producing Escherichia coli Following Diarrheal Illness

Orr, Pamela; Milley, Douglas; Colby, Dawn; Fast, Margaret

doi:10.1093/clinids/19.4.796

Cited by 10 publications

(4 citation statements)

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“…EPEC is a leading cause of both acute and chronic diarrhea in developing countries, while O157:H7 EHEC strains cause life-threatening hemorrhagic colitis and hemolytic-uremic syndrome and can colonize patients for prolonged periods of time (6,7,33,51). One potential consequence of lymphostatin expression might be the suppression of an immune response to the bacteria, prolonging the infection and increasing the opportunity for transmission to new hosts.…”

Section: Discussionmentioning

confidence: 99%

A Large Toxin from Pathogenic Escherichia coli Strains That Inhibits Lymphocyte Activation

Klapproth¹,

et al. 2000

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The mechanisms by which bacteria resist cell-mediated immune responses to cause chronic infections are largely unknown. We report the identification of a large gene present in enteropathogenic strains of Escherichia coli (EPEC) that encodes a toxin that specifically inhibits lymphocyte proliferation and interleukin-2 (IL-2), IL-4, and gamma interferon production in response to a variety of stimuli. Lymphostatin, the product of this gene, is predicted to be 366 kDa and shares significant homology with the catalytic domains of the large clostridial cytotoxins. A mutant EPEC strain that has a disruption in this gene lacks the ability to inhibit lymphokine production and lymphocyte proliferation. Enterohemorrhagic E. coli strains of serotype O157:H7 possess a similar gene located on a large plasmid. Loss of the plasmid is associated with loss of the ability to inhibit IL-2 expression while transfer of the plasmid to a nonpathogenic strain of E. coli is associated with gain of this activity. Among 89 strains of E. coli and related bacteria tested, lifA sequences were detected exclusively in strains capable of attaching and effacing activity. Lymphostatin represents a new class of large bacterial toxins that blocks lymphocyte activation.Bacteria have evolved a number of mechanisms, including antiphagocytic factors, leukotoxins, and systems for iron chelation, to resist the nonspecific (innate) immune response of vertebrate hosts (25). In addition, several mechanisms to circumvent humoral immunity have been described, such as immunoglobulin A proteases and immunoglobulin-binding proteins. However, few bacterial factors that specifically interfere with cellular immune responses have been described (69). In addition, the mechanisms that allow certain bacterial pathogens to colonize hosts for prolonged periods remain obscure.Enteropathogenic Escherichia coli (EPEC) is a leading cause of diarrhea among infants in developing countries. EPEC is one of the few known bacterial causes of chronic diarrhea (24,34,55). EPEC strains are characterized by their ability to induce profound cytoskeletal rearrangements in host cells that result in the formation of adhesion pedestals upon which the bacteria rest (47). This phenomenon is known as the attaching and effacing effect. Enterohemorrhagic E. coli (EHEC) strains, a subgroup of Shiga-toxin-producing E. coli, also have attaching and effacing activity (26, 64). We previously reported that EPEC produce and secrete a high-molecular-weight, proteasesensitive factor that selectively inhibits production of interleukin-2 (IL-2), IL-4, IL-5, and gamma interferon by human peripheral and lamina propria mononuclear cells and inhibits proliferation of these cells (35,36,41). This inhibitory effect was observed regardless of whether the cells were stimulated by phorbol esters, mitogens, CD3 cross-linking, or antigen. The effect was also seen in macrophage-depleted T-cell populations and in Jurkat cells, indicating that this activity did not require participation of cells other than lymphocytes. ...

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Section: Discussionmentioning

confidence: 99%

A Large Toxin from Pathogenic Escherichia coli Strains That Inhibits Lymphocyte Activation

Klapproth¹,

et al. 2000

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“…Orr et al. described a sporadic case of STEC O rough:H21 infection, in which asymptomatic excretion was detectable for 6 months after the acute phase. Pai et al.…”

Section: Chapter 4 Verotoxin/shiga Toxin‐producing (Vtec/stec) O117:mentioning

confidence: 99%

Characterization of four Escherichia coli clonal groups

Olesen

2017

APMIS

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(1991)(1992) that involved an unusual multi-resistant E. coli O78:H10 strain. Surprisingly, the isolates qualified as enteroaggregative E. coli (EAEC), a diarrheagenic pathotype, making this the first reported involvement of EAEC in an extraintestinal disease outbreak. Paper IV reports an analysis of 51 archived E. coli O78:H10 isolates (1956 2000) that showed E. coli O78:H10 to be clonally heterogeneous, comprising one dominant clonal group (61% of isolates, including all 19 Copenhagen outbreak isolates) from ST10 (phylogenetic group A), plus several minor clonal groups (phylogenetic groups A and D). The outbreak clone exhibited both extraintestinal pathogenic E. coli (ExPEC) and EAEC characteristics. Paper V reports evidence that the outbreak strain adhered more extensively to human bladder epithelial cells than did prototype uropathogenic (ExPEC) strains thanks to its aggregative adherence fimbriae, the principal adhesins of EAEC, and was capable of extensive biofilm formation on urethral catheters. These findings suggest that certain EAEC-specific virulence factors increase uropathogenicity.Paper VI reports a search for ST131, a globally disseminated, recently emerged multiresistant ExPEC clonal group, among 115 extended-spectrum beta-lactamase (ESBL)-producing E. coli clinical isolates from Danish patients (2008 -2009), to assess ST131's prevalence in Copenhagen among ESBL-producing isolates. ST131 was the most prevalent clonal group (38% of isolates) and compared with other ESBL isolates was more often community-associated and exhibited distinctive and extensive virulence profiles.Paper VII reports temporal trends in antimicrobial resistance and virulence genes among historical E. coli ST131 isolates (1968 -2011). Antimicrobial resistance increased over time due to emergence of the (resistance-associated) H30 and H30-Rx ST131 subclones. Distinctive characteristics of the ST131 H30-Rx subclone including specific virulence factors (iutA, afa/dra, kpsM II), K100 capsule, multidrug resistance, and ESBL production possibly contributed to this lineage's epidemiologic success. These findings confirm that ST131 represents a group of distinctive subclones, not a unitary entity.In conclusion, all four clonal groups were multiresistant and demonstrated the potential to spread locally or globally. A combination of antimicrobial resistance and specific virulence genes likely contributed to their epidemiologic success. Future implementation of rapid methods to screen for such multiresistant high-risk clones and their cardinal virulence genes conceivably could assist in clinical management and prevention efforts.

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“…Im Zusammenhang mit Infektionsfällen ist jedoch bekannt, dass symptomlose Träger vorkommen können [9,10]. Bislang liegen über das asymptomatische Ausscheiden von VTEC beim gesunden Menschen in lebensmittelverarbeitenden Betrieben allerdings nur wenig Informationen vor.…”

Section: Vtec · Ehec · Food Safety · Raw Sausages · Asymptomatic Shedunclassified

“…Über ein asymptomatisches Ausscheidertum von VTEC im Zusammenhang mit Infektionserkrankungen wurde bereits früher berichtet [9,10], über das Vorkommen von gesunden, klinisch symptomlosen VTEC-Ausscheidern unter dem Personal in lebensmittelverarbeitenden Betrieben liegen bislang allerdings wenig Erkenntnisse vor. Stephan [11] Der Serotyp O91 wurde erstmalig in der Kalenderwoche 6 in einer streichfähigen Rohwurst detektiert, eine Woche später dann in der Stuhlprobe des Mitarbeiters II und anschließend mehrmals in Produktproben als auch den Stuhlproben.…”

Section: Diskussionunclassified

Nachweis Verotoxin-bildender E-coli (VTEC) bei gesunden Mitarbeitern eines Fleisch verarbeitenden Betriebes

Gareis¹,

Pichner²,

Brey³

et al. 2000

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschu

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Prolonged Fecal Excretion of Verotoxin-Producing Escherichia coli Following Diarrheal Illness

Cited by 10 publications

References 0 publications

A Large Toxin from Pathogenic Escherichia coli Strains That Inhibits Lymphocyte Activation

A Large Toxin from Pathogenic Escherichia coli Strains That Inhibits Lymphocyte Activation

Characterization of four Escherichia coli clonal groups

Nachweis Verotoxin-bildender E-coli (VTEC) bei gesunden Mitarbeitern eines Fleisch verarbeitenden Betriebes

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