Document Type

Article

Publication Date

12-1-2006

Identifier

PMCID: PMC1694447, DOI: 10.1128/CVI.00205-06

Abstract

Although cattle develop humoral immune responses to Shiga-toxigenic (Stx+) Escherichia coli O157:H7, infections often result in long-term shedding of these human pathogenic bacteria. The objective of this study was to compare humoral and cellular immune responses to Stx+ and Stx- E. coli O157:H7. Three groups of calves were inoculated intrarumenally, twice in a 3-week interval, with different strains of E. coli: a Stx2-producing E. coli O157:H7 strain (Stx2+ O157), a Shiga toxin-negative E. coli O157:H7 strain (Stx- O157), or a nonpathogenic E. coli strain (control). Fecal shedding of Stx2+ O157 was significantly higher than that of Stx- O157 or the control. Three weeks after the second inoculation, all calves were challenged with Stx2+ O157. Following the challenge, levels of fecal shedding of Stx2+ O157 were similar in all three groups. Both groups inoculated with an O157 strain developed antibodies to O157 LPS. Calves initially inoculated with Stx- O157, but not those inoculated with Stx2+ O157, developed statistically significant lymphoproliferative responses to heat-killed Stx2+ O157. These results provide evidence that infections with STEC can suppress the development of specific cellular immune responses in cattle, a finding that will need to be addressed in designing vaccines against E. coli O157:H7 infections in cattle.

Journal Title

Clin Vaccine Immunol

Volume

13

Issue

12

First Page

1322

Last Page

1327

MeSH Keywords

Animals; Antibodies; Bacterial; Cattle; Cattle Diseases; Escherichia coli Infections; Escherichia coli O157; Humans; Leukocytes; Mononuclear; Lymphocyte Activation; Shiga Toxin 2

Keywords

E coli O157:H7; Cows; Immune response

Comments

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1694447/

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