Jb. Molloy et al., DEVELOPMENT OF AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR DETECTION OF ANTIBODIES TO BABESIA-BIGEMINA IN CATTLE, Parasitology research, 84(8), 1998, pp. 651-656
Monoclonal antibodies, directed against a 58-kDa Babesia bigemina mero
zoite antigen that reacted strongly with immune sera from experimental
ly and naturally infected cattle in Western blots, were used to develo
p a competitive-inhibition enzyme-linked immunosorbent assay (ELISA).
As based on the testing of 70 antibody-positive sera from experimental
ly infected cattle and 166 antibody-negative sera collected in nonende
mic areas of Australia, the sensitivity and specificity of the ELISA w
ere 95.7% and 97.0%, respectively. In sequential sera collected from s
ix calves during the course of experimental B. bigemina infections the
ELISA detected seroconversion at about 10 days post-inoculation. The
specificity of the ELISA was not affected by the presence of antibodie
s to B. bovis, Anaplasma marginale or Theileria buffeli. In 42 sera fr
om cattle experimentally infected with B. bovis but negative for B, bi
gemina the specificity of the ELISA was 95.2%. The use of a competitiv
e-inhibition ELISA format detecting only antibody directed against a s
ingle epitope on the 58-kDa antigen appears to have overcome many of t
he specificity problems that have plagued serological tests for B. big
emina in the past. The test should be useful for epidemiology studies,
particularly in areas where B, bovis and B. bigemina have overlapping
distributions.