Evaluation of serologic responses, lymphocyte proliferative responses, and clearance from lymphatic organs after vaccination of bison with Brucella abortus strain RB51.
OBJECTIVE
To evaluate clearance of the vaccine strain, immunologic responses, and potential shedding of Brucella abortus strain RB51 organisms after vaccination of bison calves.


METHODS
Fourteen 7-month-old female bison calves.


METHODS
10 bison calves were vaccinated SC with 1.22 x 10(10) colony-forming units of B abortus strain RB51. Four bison calves were vaccinated SC with 0.15M NaCl solution. Rectal, vaginal, nasal, and ocular swab specimens were obtained to evaluate potential shedding by vaccinated bison. The superficial cervical lymph node was biopsied to evaluate clearance of the vaccine strain. Lymphocyte proliferative responses to strain RB51 bacteria were evaluated in lymph node cells obtained from biopsy specimens and also in peripheral blood mononuclear cells.


RESULTS
Strain RB51 was recovered from superficial cervical lymph nodes of vaccinates examined 6, 12, and 18 weeks after vaccination (4/4, 3/4, and 1/4, respectively) but not in vaccinates examined at 24 weeks (0/3) after vaccination or nonvaccinates examined at all sample collection times (n = 1 bison/sample period). Serologic, immunologic, and bacterial culture techniques failed to reveal shedding of strain RB51 by vaccinates or infection of nonvaccinated bison. Lymphocyte proliferative responses were evident in lymph node cells and blood mononuclear cells from strain RB51-vaccinated bison beginning 12 weeks after vaccination.


CONCLUSIONS
Strain RB51 was cleared from bison by 18 to 24 weeks after vaccination. Bison vaccinated with strain RB51 did not shed the vaccine strain to nonvaccinated bison housed in close proximity. Strain RB51 did not induce antibody responses in bison that would interfere with brucellosis surveillance tests, but did stimulate cell-mediated immunity.
Olsen
S C
SC
National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA 50010, USA.
Jensen
A E
AE
Palmer
M V
MV
Stevens
M G
MG
D000372:Agglutination Tests; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000917:Antibody Formation; D016164:Bison; D002004:Brucella Vaccine / Q000493:pharmacokinetics; D002003:Brucella abortus / Q000302:isolation & purification / Q000502:physiology; D002006:Brucellosis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D008198:Lymph Nodes / Q000382:microbiology*; D008213:Lymphocyte Activation
D000907:Antibodies, Bacterial; D002004:Brucella Vaccine