| Autor: |
P H, Elzer, F M, Enright, L, Colby, S D, Hagius, J V, Walker, M B, Fatemi, J D, Kopec, V C, Beal, G G, Schurig |
| Rok vydání: |
1998 |
| Předmět: |
|
| Zdroj: |
American journal of veterinary research. 59(12) |
| ISSN: |
0002-9645 |
| Popis: |
To determine efficacy of orally administered Brucella abortus vaccine strain RB51 against virulent B abortus challenge exposure in cattle as a model for vaccination of wild ungulates.20 mixed-breed beef cattle obtained from a brucellosis-free herd.Sexually mature, Brucella-negative beef heifers were vaccinated by mixing10' viable RB51 organisms or diluent with their feed. Heifers were fed individually and consumed their entire ration. Each heifer received approximately 3 X 10' colony-forming units (CFU). Six weeks after oral vaccination, heifers were pasture-bred to brucellosis-free bulls. At approximately 186 days' gestation, heifers were challenge exposed conjunctively with 107 CFU of virulent B abortus strain 2308.Vaccination with the rough variant of B abortus RB51 did not stimulate antibodies against the O-polysaccharide (OPS) of B abortus. After challenge exposure and parturition, strain 2308 was recovered from 80% of controls and only 20% of vaccinates. Only 30% of the vaccinates delivered dead, premature, or weak calves, whereas 70% of the controls had dead or weak calves.Cattle vaccinated orally with the rough variant of B abortus strain RB51 develop significant (P0.05) protection against abortion and colonization and do not produce OPS-specific antibodies. Clinical Relevance-Results encourage further investigation into use of strain RB51 to vaccinate wild ungulates (elk and bison) orally. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
