title: An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against Babesia bovis in cattle.
abstract: A method for the isolation of Babesia bovis merozoites from infected erythrocytes (Machado et al., 1994) and an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-B. bovis antibodies were developed. This ELISA utilizes a soluble, alkali-digested B. bovis antigen. Sera from calves experimentally infected with B. bovis were screened by this technique from day 9 to day 233 postinfection (PI). Maximum titers were reached between days 29 and 149 PI. Sera from calves (n = 62), heifers (n = 38) and cows (n = 49), raised in tick-infested areas of São Paulo State, showed higher antibody levels in heifers and cows. A higher percentage of negative sera (19.4%) was found among calves. Sodium dodecyl sulphate-polyacrylamide electrophoresis (SDS-PAGE) and immunoblotting have identified proteins of similar molecular mass in the two species. Sera from calves experimentally infected with B. bovis reacted with homologous antigens at the level of 95, 66 and 23 kDa. The same serum reacted with the 23 kDa band of heterologous antigen. Sera from calves experimentally infected with B. bigemina recognized 82, 66, 58, 36 and the 23 kDa polypeptides of homologous and heterologous antigens. The experimental ELISA described may prove to be a practical serological test for bovine Babesia infection with the choice of specific test antigen for B. bovis and B. bigemina.
authors.affiliation: Faculdade de Ciências Agrárias e Veterinárias-UNESP, Rod. Carlos Tonanni, Jaboticabal, São Paulo, Brazil.
authors.forename: R Z
authors.initials: RZ
authors.lastname: Machado
authors.forename: H J
authors.initials: HJ
authors.lastname: Montassier
authors.forename: A A
authors.initials: AA
authors.lastname: Pinto
authors.forename: E G
authors.initials: EG
authors.lastname: Lemos
authors.forename: M R
authors.initials: MR
authors.lastname: Machado
authors.forename: I F
authors.initials: IF
authors.lastname: Valadão
authors.forename: L G
authors.initials: LG
authors.lastname: Barci
authors.forename: E B
authors.initials: EB
authors.lastname: Malheiros
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000917:Antibody Formation; D016793:Babesia bovis / Q000276:immunology*; D001404:Babesiosis / Q000175:diagnosis* / Q000276:immunology; D015153:Blotting, Western; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000276:immunology / Q000469:parasitology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D005260:Female; D013997:Time Factors
chemical_list: D000913:Antibodies, Protozoan