Non-toxigenic Escherichia coli O157:H7 strain NCTC12900 causes attaching-effacing lesions and eae-dependent persistence in weaned sheep

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Abstract

Ruminants are regarded as a primary reservoir for Escherichia coli O157:H7, an important human pathogen. Intimin, encoded by the Locus of Enterocyte Effacement by E. coli O157:H7 organisms, has been cited as one bacterial mechanism of colonisation of the gastrointestinal tract. To confirm this and to test whether a non-toxigenic E. coli O157:H7 strain would colonise and persist in a sheep model, E. coli O157:H7 strain NCTC12900, that lacks Shiga toxin (stx) genes, was evaluated for use in a sheep model of persistence. Following oral inoculation of six-week-old sheep, persistent excretion of NCTC12900 was observed for up to 48 days. E. coli O157-associated attaching-effacing (AE) lesions were detected in the caecum and rectum of one six-week-old lamb, one day after inoculation. This is the first recorded observation of AE lesions in orally inoculated weaned sheep. Also, mean faecal excretion scores of NCTC12900 and an isogenic intimin (eae)-deficient mutant were determined from twenty-four six-week-old orally inoculated sheep. The eae mutant was cleared within 20 days and had lower mean excretion scores at all time points after day one post inoculation compared with the parental strain that was still being excreted at 48 days. Tissues were collected post mortem from animals selected at random from the study groups over the time course of the experiment. The eae mutant was detected in only 1/43 samples but the parental strain was recovered from 64/140 samples primarily from the large bowel although rumen, duodenum, jejunum, and ileum were culture positive especially from animals that were still excreting at and beyond 27 days after inoculation.

References (41)

  • P.A. Chapman et al.

    A 1-year study of Escherichia coli O157 in cattle, sheep, pigs and poultry

    Epidemiol. Infect

    (1997)
  • A.L. Cookson et al.

    Experimental inoculation of six-week old lambs with Escherichia coli O157:H7

    J. Med. Microbiol

    (2002)
  • A.L. Cookson et al.

    Isolation from a sheep of an attaching and effacing Escherichia coli O115:H- with a novel combination of virulence factors

    J. Med. Microbiol

    (2002)
  • N.A. Cornick et al.

    Persistent colonization of sheep by Escherichia coli O157:H7 and other E. coli pathotypes

    Appl. Environ. Microbiol

    (2000)
  • N.A. Cornick et al.

    Intimin facilitates colonisation by Escherichia coli O157:H7 in adult ruminants

    Infect. Immun

    (2002)
  • W.C. Cray et al.

    Experimental infection of calves and adult cattle with Escherichia coli O157:H7

    Appl. Environ. Microbiol

    (1995)
  • E.A. Dean-Nystrom et al.

    Pathogenicity of Escherichia coli O157:H7 in the intestines of neonatal calves

    Infect. Immun

    (1997)
  • E.A. Dean-Nystrom et al.

    Escherichia coli O157:H7 requires intimin for enteropathogenicity in calves

    Infect. Immun

    (1998)
  • E.A. Dean-Nystrom et al.

    Bovine infection with Escherichia coli O157:H7

  • E.A. Dean-Nystrom et al.

    Vaccination of pregnant dams with intiminO157 protects suckling piglets from Escherichia coli O157:H7 infection

    Infect. Immun

    (2002)
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