title: Cloning of a novel Babesia equi gene encoding a 158-kilodalton protein useful for serological diagnosis.
abstract: In this study, we characterized a Babesia equi Be158 gene obtained by immunoscreening a B. equi cDNA expression phage library with B. equi-infected horse serum. The Be158 gene consists of an open reading frame of 3,510 nucleotides. The recombinant Be158 gene product was produced in Escherichia coli and used for the immunization of mice. In Western blot analysis, mouse immune serum against the Be158 gene product recognized 75- and 158-kDa proteins from the lysate of B. equi-infected erythrocytes. In an indirect fluorescent-antibody test with the mouse immune serum, the Be158 antigen appeared in the cytoplasm of Maltese cross-forming parasites (which consist of four merozoites) and was located mainly in the extraerythrocytic merozoite body. When the recombinant Be158 gene product was used in an enzyme-linked immunosorbent assay as a serological antigen, it was found to react to B. equi-infected horse sera, indicating that the Be158 gene product is useful as a serologically diagnostic antigen for B. equi infection.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Hirata
authors.forename: Naoaki
authors.initials: N
authors.lastname: Yokoyama
authors.forename: Xuenan
authors.initials: X
authors.lastname: Xuan
authors.forename: Kozo
authors.initials: K
authors.lastname: Fujisaki
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Suzuki
authors.forename: Ikuo
authors.initials: I
authors.lastname: Igarashi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology*; D001403:Babesia / Q000276:immunology*; D001404:Babesiosis / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004912:Erythrocytes / Q000469:parasitology; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis* / Q000469:parasitology; D006736:Horses / Q000469:parasitology; D007106:Immune Sera / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D018076:DNA, Complementary; D007106:Immune Sera; D015800:Protozoan Proteins