Antibody to a recombinant merozoite protein epitope identifies horses infected with Babesia equi

• Published in: Journal of Clinical Microbiology Vol. 30; no. 12; pp. 3122 - 3126
• Main Authors: Knowles, D.P. Jr. (ARS, USDA, Pullman, WA), Kappmeyer, L.S, Stiller, D, Hennager, S.G, Perryman, L.E
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.12.1992
• Subjects: Animal protozoal diseases; Animals; Antibodies, Protozoan - blood; ANTICORPS; ANTICUERPOS; ANTIGENE; ANTIGENOS; Antigens, Protozoan; Babesia - immunology; BABESIA EQUI; Babesiosis - diagnosis; Babesiosis - immunology; Biological and medical sciences; BOOPHILUS MICROPLUS; CABALLOS; CHEVAL; CLONE; CLONES; DIAGNOSTIC; DIAGNOSTICO; ELISA; Enzyme-Linked Immunosorbent Assay; EPIDEMIOLOGIA; EPIDEMIOLOGIE; Epitopes; Evaluation Studies as Topic; EXPERIMENTACION IN VIVO; EXPERIMENTATION IN VIVO; GENE; GENES; Horse Diseases - diagnosis; Horse Diseases - immunology; Horses; IMMUNSERUM; INFECCION; INFECTION; Infectious diseases; Medical sciences; Parasitic diseases; Protozoal diseases; Protozoan Proteins - immunology; RECOMBINACION; RECOMBINAISON; Recombinant Proteins - immunology; REPONSE IMMUNITAIRE; RESPUESTA INMUNOLOGICA; SUERO INMUNE; TEST ELISA; Time Factors; VECTEUR DE MALADIE; VECTORES; Protozoa; Antigenic determinant; Babesia equi; Identification; Serology; Monoclonal antibody; Antigen; Vertebrata; Mammalia; Animal; Horse; Merozoite; Perissodactyla; Recombinant protein; Sporozoa; ELISA assay; Ungulata
• ISSN: 0095-1137; 1098-660X
• DOI: 10.1128/jcm.30.12.3122-3126.1992

Horses infected with Babesia equi were previously identified by the presence of antibodies reactive with a merozoite surface protein epitope (D. P. Knowles, Jr., L. E. Perryman, L. S. Kappmeyer, and S. G. Hennager. J. Clin. Microbiol. 29:2056-2058, 1991). The antibodies were detected in a competitive inhibition enzyme-linked immunosorbent assay (CI ELISA) by using monoclonal antibody 36/133.97, which defines a protein epitope on the merozoite surface. The gene encoding this B. equi merozoite epitope was cloned and expressed in Escherichia coli. The recombinant merozoite protein, designated equi merozoite antigen 1 (EMA-1), was evaluated in the CI ELISA. Recombinant EMA-1 bound antibody from the sera of B. equi-infected horses from 18 countries. The antibody response to EMA-1 was then measured in horses experimentally infected with B. equi via transmission by the tick vector Boophilus microplus or by intravenous inoculation. Anti-EMA-1 antibody was detected 7 weeks post-tick exposure and remained, without reexposure to B. equi, for the 33 weeks of the evaluation period. The data indicate that recombinant EMA-1 can be used in the CI ELISA to detect horses infected with B. equi