title: Diagnostic value of the recombinant tandem repeat antigen TeGM6-4r for surra in water buffaloes.
abstract: Trypanosoma evansi infection, or surra, is currently affecting various species of animals, especially water buffaloes. Since diagnosis is an important aspect of surra control, development of novel diagnostic antigens is of interest to implement and improve the currently utilized methods. Our study evaluated the tandem repeat antigen TeGM6-4r in T. evansi antibody detection in water buffaloes. TeGM6-4r-based ELISA was performed with 20 positive and 8 negative controls and 484 field samples from water buffaloes in Northern Vietnam. To examine cross-reactivity, sera from Japanese cattle that had been experimentally infected with Theileria orientalis (n=10), Babesia bovis (n=3), Babesia bigemina (n=7) and Trypanosoma theileri (n=59) were included in the study. The sensitivity of the test was 80%. TeGM6-4r did not react with Theileria or Babesia infected sera, however it showed cross reactivity with 11/59 T. theileri infected samples. The reference test, CATT/T. evansi also reacted with 3/59 T. theileri infected sera. The lysate antigen-based ELISA reacted with 4/59 T. theileri, 9/10 Theileria and 3/10 Babesia infected sera. In contrast, TeGM6-4r-based ELISA was 86.3% sensitive and 58.3% specific in the screening of field samples. The average seroprevalence of T. evansi infection among water buffaloes in Northern Vietnam was 27.1% by CATT/T. evansi and 53.7% by TeGM6-4r. Seroprevalence in the five surveyed provinces ranged from 17.4% to 39.8% in the reference test, and 47.3% to 67.3% in the recombinant antigen based test. The finding indicated that the disease is still widely endemic in the area and that surveillance programs need to be carried out regularly to better control surra. We proposed TeGM6-4r as a useful serodiagnostic antigen for the detection and epidemiological surveillance of T. evansi infection among water buffaloes.
authors: OIE Reference Laboratory for Surra, OIE Collaborating Center, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
authors: Thu-Thuy
authors: TT
authors: Nguyen
authors: OIE Reference Laboratory for Surra, OIE Collaborating Center, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
authors: Mo
authors: M
authors: Zhou
authors: OIE Reference Laboratory for Surra, OIE Collaborating Center, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
authors: Ngasaman
authors: N
authors: Ruttayaporn
authors: National Institute for Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Viet Nam.
authors: Quoc Doanh
authors: QD
authors: Nguyen
authors: National Institute for Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Viet Nam.
authors: Viet Khong
authors: VK
authors: Nguyen
authors: Laboratory of Molecular Immunology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors: Yasuyuki
authors: Y
authors: Goto
authors: Research Center for Zoonosis Control, Hokkaido University, North 20, West 10, Kita-ku Sapporo, Hokkaido 001-0020, Japan.
authors: Yasuhiko
authors: Y
authors: Suzuki
authors: OIE Reference Laboratory for Surra, OIE Collaborating Center, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
authors: Shin-ichiro
authors: S
authors: Kawazu
authors: OIE Reference Laboratory for Surra, OIE Collaborating Center, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan. Electronic address: ircpmi@obihiro.ac.jp.
authors: Noboru
authors: N
authors: Inoue
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan; D002020:Buffaloes / Q000469:parasitology*; D004274:DNA, Recombinant; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards / Q000662:veterinary*; D010273:Parasitic Diseases, Animal / Q000175:diagnosis* / Q000453:epidemiology; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D020080:Tandem Repeat Sequences / Q000235:genetics*; D014345:Trypanosoma / Q000235:genetics / Q000276:immunology; D014352:Trypanosomiasis / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D014744:Vietnam / Q000453:epidemiology
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D004274:DNA, Recombinant
keywords: Seroprevalence; Tandem repeat antigen; Trypanosoma evansi; Vietnam; Water buffalo