title: Comparison between indirect enzyme-linked immunosorbent assays for Anaplasma marginale antibodies with recombinant major surface protein 5 and initial body antigens.
abstract: Indirect enzyme-linked immunosorbent assays (ELISAs) based on recombinant major surface protein 5 (rMSP5) and initial body (IB) antigens from a Brazilian isolate of Anaplasma marginale were developed to detect antibodies against this rickettsia in cattle. Both tests showed the same sensitivity (98.2%) and specificities (100% for rMSP5 and 93.8% for IB ELISA) which did not differ statistically. No cross-reactions were detected with Babesia bigemina antibodies, but 5 (rMSP5 ELISA) to 15% (IB ELISA) of cross-reactions were detected with B. bovis antibodies. However, such difference was not statistically significant. Prevalences of seropositive crossbred beef cattle raised extensively in Miranda county, state of Mato Grosso do Sul, Brazil, were 78.1% by rMSP5 ELISA and 79.7% by IB ELISA. In the analysis of sera from dairy calves naturally-infected with A. marginale, the dynamics of antibody production was very similar between both tests, with maternal antibodies reaching the lowest levels at 15-30 days, followed by an increase in the mean optical densities in both ELISAs, suggesting the development of active immunity against A. marginale. Results showed that all calves were seropositive by one-year old, characterizing a situation of enzootic stability. The similar performances of the ELISAs suggest that both tests can be used in epidemiological surveys for detection of antibodies to A. marginale in cattle.
authors.affiliation: Pós-Graduação em Imunologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, BA, Brasil.
authors.forename: Virgínia M G
authors.initials: VM
authors.lastname: Silva
authors.forename: Flábio R
authors.initials: FR
authors.lastname: Araújo
authors.forename: Claudio R
authors.initials: CR
authors.lastname: Madruga
authors.forename: Cleber O
authors.initials: CO
authors.lastname: Soares
authors.forename: Raul H
authors.initials: RH
authors.lastname: Kessler
authors.forename: Maria A O
authors.initials: MA
authors.lastname: Almeida
authors.forename: Stênio P
authors.initials: SP
authors.lastname: Fragoso
authors.forename: Lenita R
authors.initials: LR
authors.lastname: Santos
authors.forename: Carlos A N
authors.initials: CA
authors.lastname: Ramos
authors.forename: Gisele
authors.initials: G
authors.lastname: Bacanelli
authors.forename: Roberto A A Júnior
authors.initials: RA
authors.lastname: Torres
mesh_terms: D042322:Anaplasma marginale / Q000276:immunology*; D000712:Anaplasmosis / Q000175:diagnosis*; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis* / Q000276:immunology; D000942:Antigens, Bacterial; D001403:Babesia / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins; D002417:Cattle; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004912:Erythrocytes / Q000382:microbiology; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; C111578:major surface protein 5, Anaplasma