Experimental infection of gnotobiotic piglets with Escherichia coli strains positive for EAST1 and AIDA

Zajacova, Z. Sramkova; Faldyna, Martin; Kulich, Pavel; Kummer, V.; Mašková, J.; Alexa, P.

doi:10.1016/j.vetimm.2012.09.011

Cited by 12 publications

(11 citation statements)

References 25 publications

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“…However, evidence for any effect in elder or conventionally reared piglets is still lacking. Similarly, the toxin EAST1 (enteroaggregative E. coli heat stable enterotoxin) is commonly detected among porcine ETEC although its role in PWD remains yet to be clarified [13, 22]. Likewise, we cannot exclude the presence of enteropathogenic E. coli (EPEC) among those isolates or the involvement of other pathogens in the cases of PWD described in this study.…”

Section: Discussionmentioning

confidence: 88%

Prevalence of virulence factors in enterotoxigenic Escherichia coli isolated from pigs with post-weaning diarrhoea in Europe

et al. 2016

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BackgroundPost-weaning diarrhoea (PWD), due to Escherichia coli, is an important cause of economic losses to the pig industry primarily as a result of mortality and worsened productive performance. In spite of its relevance, recent data about the prevalence of virulence genes and pathotypes among E. coli isolates recovered from cases of PWD in Europe are scarce.ResultsThis study investigates the prevalence of fimbrial and toxin genes of E. coli by PCR among 280 farms with PWD across Europe. A total of 873 samples collected within the first 48 h after the onset of PWD (occurring 7–21 days post weaning) were submitted to the laboratory for diagnostic purposes. Isolation and identification of E. coli were performed following standard bacteriological methods and PCR assays for the detection of genes encoding for fimbriae (F4, F5, F6, F18 and F41) and toxins (LT, STa, STb and Stx2e). The prevalence of fimbriae and toxins among E. coli isolates from cases of PWD was: F4 (45.1 %), F18 (33.9 %), F5 (0.6 %), F6 (0.6 %), F41 (0.3 %), STb (59.1 %), STa (38.1 %), LT (31.9 %) and Stx2e (9.7 %). E. coli isolates carrying both fimbrial and toxin genes were detected in 52.5 % of the cases (178 out of 339 isolates), with 94.9 % of them being classified as enterotoxigenic E. coli (ETEC). The most common virotype detected was F4, STb, LT.ConclusionsThis study confirms that ETEC is frequently isolated in pig farms with PWD across Europe, with F4- and F18-ETEC variants involved in 36.1 % and 18.2 % of the outbreaks, respectively.

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Section: Discussionmentioning

confidence: 88%

Prevalence of virulence factors in enterotoxigenic Escherichia coli isolated from pigs with post-weaning diarrhoea in Europe

et al. 2016

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“…EAST1 alone seems not sufficient to cause diarrhea in 5-day old gnotobiotic pigs suggesting that EAST1 is likely not a virulence determinant in ETEC-associated diarrhea. An experimental infection with E. coli strains positive for EAST1 and AIDA and a F4/EAST1-positive strains, in gnotobiotic piglets, did not produce diarrhea either (431). Although the EAST1/AIDA strain used in the study was present in fecal shedding of challenged animals it was not markedly associated with intestinal epithelial surface.…”

Section: East1mentioning

confidence: 99%

Animal EnterotoxigenicEscherichia coli

2016

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Enterotoxigenic Escherichia coli (ETEC) is the most common cause of E. coli diarrhea in farm animals. ETEC are characterized by the ability to produce two types of virulence factors; adhesins that promote binding to specific enterocyte receptors for intestinal colonization and enterotoxins responsible for fluid secretion. The best-characterized adhesins are expressed in the context of fimbriae, such as the F4 (also designated K88), F5 (K99), F6 (987P), F17 and F18 fimbriae. Once established in the animal small intestine, ETEC produces enterotoxin(s) that lead to diarrhea. The enterotoxins belong to two major classes; heat-labile toxin that consist of one active and five binding subunits (LT), and heat-stable toxins that are small polypeptides (STa, STb, and EAST1). This chapter describes the disease and pathogenesis of animal ETEC, the corresponding virulence genes and protein products of these bacteria, their regulation and targets in animal hosts, as well as mechanisms of action. Furthermore, vaccines, inhibitors, probiotics and the identification of potential new targets identified by genomics are presented in the context of animal ETEC.

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“…But as Stx2e is frequently found in ETEC strains expressing LT and/or ST toxins (Zajacova et al, 2012;Zhang et al, 2007), it was also targeted for ETEC diarrhea prevention. In contrast, E. coli strains expressing fimbriae and EAST1 are found not associated with diarrhea in young pigs (Ruan et al, 2012;Zajacova et al, 2013). It is thought that a vaccine blocking attachment from all ETEC fimbrial adhesins to host receptors and/ or eliminating enterotoxicity of ETEC toxins to host epithelial cells would be able to effectively protect against ETEC diarrhea in pigs and humans (Boedeker, 2005;Walker, 2005;Zhang and Sack, 2012).…”

Section: Introductionmentioning

confidence: 99%

Antibodies derived from a toxoid MEFA (multiepitope fusion antigen) show neutralizing activities against heat-labile toxin (LT), heat-stable toxins (STa, STb), and Shiga toxin 2e (Stx2e) of porcine enterotoxigenic Escherichia coli (ETEC)

Rausch

Ruan

Nandre

et al. 2017

Veterinary Microbiology

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Enterotoxigenic Escherichia coli (ETEC) strains are the main cause of diarrhea in pigs. Pig diarrhea especially post-weaning diarrhea remains one of the most important swine diseases. ETEC bacterial fimbriae including K88, F18, 987P, K99 and F41 promote bacterial attachment to intestinal epithelial cells and facilitate ETEC colonization in pig small intestine. ETEC enterotoxins including heat-labile toxin (LT) and heat-stable toxins type Ia (porcine-type STa) and type II (STb) stimulate fluid hyper-secretion, leading to watery diarrhea. Blocking bacteria colonization and/or neutralizing enterotoxicity of ETEC toxins are considered effective prevention against ETEC diarrhea. In this study, we applied the MEFA (multiepitope fusion antigen) strategy to create toxoid MEFAs that carried antigenic elements of ETEC toxins, and examined for broad antitoxin immunogenicity in a murine model. By embedding STa toxoid STa (NTFYCCELCCNFACAGCY), a STb epitope (KKDLCEHY), and an epitope of Stx2e A subunit (QSYVSSLN) into the A1 peptide of a monomeric LT toxoid (LT), two toxoid MEFAs, 'LT-STb-Stx2e-STa' and 'LT-STb-Stx2e-3xSTa' which carried three copies of STa, were constructed. Mice intraperitoneally immunized with each toxoid MEFA developed IgG antibodies to all four toxins. Induced antibodies showed in vitro neutralizing activities against LT, STa, STb and Stx2e toxins. Moreover, suckling piglets born by a gilt immunized with 'LT-STb-Stx2e-3xSTa' were protected when challenged with ETEC strains, whereas piglets born by a control gilt developed diarrhea. Results from this study showed that the toxoid MEFA induced broadly antitoxin antibodies, and suggested potential application of the toxoid MEFA for developing a broad-spectrum vaccine against ETEC diarrhea in pigs.

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Experimental infection of gnotobiotic piglets with Escherichia coli strains positive for EAST1 and AIDA

Cited by 12 publications

References 25 publications

Prevalence of virulence factors in enterotoxigenic Escherichia coli isolated from pigs with post-weaning diarrhoea in Europe

Prevalence of virulence factors in enterotoxigenic Escherichia coli isolated from pigs with post-weaning diarrhoea in Europe

Animal EnterotoxigenicEscherichia coli

Antibodies derived from a toxoid MEFA (multiepitope fusion antigen) show neutralizing activities against heat-labile toxin (LT), heat-stable toxins (STa, STb), and Shiga toxin 2e (Stx2e) of porcine enterotoxigenic Escherichia coli (ETEC)

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