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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Infectious Bacterial Diseases Research » Research » Publications at this Location » Publication #94483


item Olsen, Steven

Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The purpose of this study was to evaluate the efficacy of 10*10 CFU of B. abortus strain RB51 administered as a calfhood vaccine to 5- to 7-month-old bison heifers. Bison were raised to 3 years of age, pasture bred, and pregnancy determined by rectal palpation. At 180 days of gestation, bison were intraconjunctivally challenged with 1 x 10*7 CFU of B. abortus strain 2308 in a biocontainment facility. Blood was obtained prior to vaccination at 4 weeks after challenge, and at necropsy for evaluation by brucellosis serologic tests. Adult bison and their calves were euthanized within 24 hours after abortion or full-term parturition and multiple tissues sampled for bacteriologic and histologic evaluation. All bison had seroconverted when evaluated by the standard tube agglutination test at 4 weeks after challenge. Both nonvaccinated bison aborted within 6 weeks after challenge and strain 2308 was recovered from multiple maternal and fetal tissues. The efive strain RB51-vaccinated bison all gave birth to full-term, clinically normal calves. Strain 2308 was not recovered at necropsy from any tissue sample obtained from calves of strain RB51 vaccinates. The challenge strain was recovered at necropsy from maternal lymphatic tissues of 4 of 5 strain RB51 vaccinates, usually parotid, mandibular, and retropharyngeal lymph nodes. The results of this study demonstrate that strain RB51 is efficacious in bison as a calfhood vaccine in protecting against abortions caused by B. abortus. As abortion and expulsion of Brucella-infected tissues and fluids are the mechanism for transmission of brucellosis, our data suggest that vaccination of bison with strain RB51 will be effective in reducing the prevalence of brucellosis in an infected bison herd. Our data also suggest that strain RB51-vaccinated bison do not clear virulent