title: Efficacy of an Escherichia coli O157:H7 SRP Vaccine in Orally Challenged Goats and Strain Persistence Over Time.
abstract: Small ruminants have been implicated in outbreaks of Escherichia coli O157:H7 at livestock exhibitions throughout the United States. Additionally, goat meat or milk may serve as a reservoir for foodborne transmission of the organism. These associations highlight the public health importance of an effective strategy to reduce E. coli O157:H7 shedding in goats. We examined the efficacy of the SRP®vaccine in goats orally challenged with E. coli O157:H7. Mixed-breed goats (n = 14) were randomly allocated into vaccinated and unvaccinated treatments (n = 7 per treatment). Goats were housed with a vaccinated and unvaccinated animal in each pen. Feces were collected for 3 weeks, then at necropsy, gastrointestinal contents were collected to determine the concentration of E. coli O157:H7. Three isolates per positive sample were saved and evaluated by pulsed-field gel electrophoresis (PFGE) to assess strain persistence over time. The mean concentration of E. coli O157:H7 in the feces of goats was numerically reduced in the vaccinated treatment; however, it was not statistically significant. In addition, the total number of days goats were fecal positive for E. coli O157:H7 were not different between vaccinated and unvaccinated treatments. Pulsotypes of isolates revealed that goats initially shed two of the four challenge strains of E. coli O157:H7, after which there was a distinct shift to two different strains. Further work is needed to evaluate cost-effective intervention strategies that reliably reduce E. coli O157:H7 shedding in goats, particularly those that may reduce the risk of transmission at public events, including petting zoos and fairs.
authors.affiliation: 1 Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Swift
authors.affiliation: 1 Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.
authors.forename: Derek M
authors.initials: DM
authors.lastname: Foster
authors.affiliation: 1 Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.
authors.forename: Anna T
authors.initials: AT
authors.lastname: Rogers
authors.affiliation: 1 Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.
authors.forename: Hannah J
authors.initials: HJ
authors.lastname: Sylvester
authors.affiliation: 2 Department of Statistics, College of Sciences, North Carolina State University , Raleigh, North Carolina.
authors.forename: Emily H
authors.initials: EH
authors.lastname: Griffith
authors.affiliation: 1 Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Jacob
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D016521:Electrophoresis, Gel, Pulsed-Field; D004927:Escherichia coli Infections / Q000517:prevention & control* / Q000662:veterinary; D019453:Escherichia coli O157 / Q000276:immunology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000276:immunology; D022361:Escherichia coli Vaccines / Q000276:immunology*; D005243:Feces / Q000382:microbiology; D005506:Food Contamination / Q000517:prevention & control; D005516:Food Microbiology; D015511:Goat Diseases / Q000382:microbiology / Q000517:prevention & control*; D006041:Goats / Q000276:immunology* / Q000382:microbiology; D008297:Male; D008892:Milk / Q000382:microbiology; D018272:Porins / Q000276:immunology; D011956:Receptors, Cell Surface / Q000276:immunology; D000069466:Red Meat / Q000382:microbiology; D014611:Vaccination / Q000662:veterinary
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D022361:Escherichia coli Vaccines; D018272:Porins; D011956:Receptors, Cell Surface; C035902:siderophore receptors
keywords: Shiga toxin-producing E. coli; goats; livestock exhibition; vaccination