title: Cloning of a truncated Babesia equi gene encoding an 82-kilodalton protein and its potential use in an enzyme-linked immunosorbent assay.
abstract: To isolate Babesia equi genes encoding immunodominant proteins, a cDNA expression library prepared from B. equi mRNA was immunoscreened with B. equi-infected horse serum. Eighteen positive cDNA clones were obtained, and the clone that showed the strongest immunoreactivity, designated Be82, was further characterized. The Be82 gene consisted of 1,953 bp and contained a partial open reading frame lacking the 5'-terminal sequence. As shown by Western blot analyses, immune sera from mice intraperitoneally injected with the Be82 gene product recognized the 82- and 52-kDa proteins of B. equi but not those of Babesia caballi. The glutathione S-transferase fusion protein expressed in Escherichia coli that was purified and used as the antigen in the enzyme-linked immunosorbent assay reacted specifically with B. equi-infected horse sera. These results suggest that the Be82 gene product is a potential diagnostic antigen candidate in the detection of B. equi infection in horses that will be useful both in the performance of epidemiological studies and in the granting of quarantine passes.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Hirata
authors.forename: Hiromi
authors.initials: H
authors.lastname: Ikadai
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: Takeshi
authors.initials: T
authors.lastname: Mikami
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 / Q000382:microbiology / Q000662:veterinary; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006734:Horse Diseases / Q000175:diagnosis* / Q000382:microbiology; D006736:Horses; D007106:Immune Sera / Q000276:immunology; D051379:Mice; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D017422:Sequence Analysis, DNA
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D018076:DNA, Complementary; D007106:Immune Sera; D015800:Protozoan Proteins; D011994:Recombinant Proteins