title: Trypanosoma vivax GM6 antigen: a candidate antigen for diagnosis of African animal trypanosomosis in cattle.
abstract: BACKGROUND
  Diagnosis of African animal trypanosomosis is vital to controlling this severe disease which hampers development across 10 million km(2) of Africa endemic to tsetse flies. Diagnosis at the point of treatment is currently dependent on parasite detection which is unreliable, and on clinical signs, which are common to several other prevalent bovine diseases.
  
  
  RESULTS
  the repeat sequence of the GM6 antigen of Trypanosoma vivax (TvGM6), a flagellar-associated protein, was analysed from several isolates of T. vivax and found to be almost identical despite the fact that T. vivax is known to have high genetic variation. The TvGM6 repeat was recombinantly expressed in E. coli and purified. An indirect ELISA for bovine sera based on this antigen was developed. The TvGM6 indirect ELISA had a sensitivity of 91.4% (95% CI: 91.3 to 91.6) in the period following 10 days post experimental infection with T. vivax, which decreased ten-fold to 9.1% (95% CI: 7.3 to 10.9) one month post treatment. With field sera from cattle infected with T. vivax from two locations in East and West Africa, 91.5% (95% CI: 83.2 to 99.5) sensitivity and 91.3% (95% CI: 78.9 to 93.1) specificity was obtained for the TvGM6 ELISA using the whole trypanosome lysate ELISA as a reference. For heterologous T. congolense field infections, the TvGM6 ELISA had a sensitivity of 85.1% (95% CI: 76.8 to 94.4).
  
  
  CONCLUSIONS
  this study is the first to analyse the GM6 antigen of T. vivax and the first to test the GM6 antigen on a large collection of sera from experimentally and naturally infected cattle. This study demonstrates that the TvGM6 is an excellent candidate antigen for the development of a point-of-treatment test for diagnosis of T. vivax, and to a lesser extent T. congolense, African animal trypanosomosis in cattle.
authors.affiliation: Microbiologie fondamentale et Pathogénicité, UMR 5234, Centre National de la Recherche Scientifique (CNRS), Université Bordeaux Segalen, Bordeaux, France.
authors.forename: Davita
authors.initials: D
authors.lastname: Pillay
authors.forename: Julien
authors.initials: J
authors.lastname: Izotte
authors.forename: Regassa
authors.initials: R
authors.lastname: Fikru
authors.forename: Philipe
authors.initials: P
authors.lastname: Büscher
authors.forename: Hermogenes
authors.initials: H
authors.lastname: Mucache
authors.forename: Luis
authors.initials: L
authors.lastname: Neves
authors.forename: Alain
authors.initials: A
authors.lastname: Boulangé
authors.forename: Momar Talla
authors.initials: MT
authors.lastname: Seck
authors.forename: Jérémy
authors.initials: J
authors.lastname: Bouyer
authors.forename: Grant B
authors.initials: GB
authors.lastname: Napier
authors.forename: Cyrille
authors.initials: C
authors.lastname: Chevtzoff
authors.forename: Virginie
authors.initials: V
authors.lastname: Coustou
authors.forename: Théo
authors.initials: T
authors.lastname: Baltz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D017124:Conserved Sequence; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D008969:Molecular Sequence Data; D016689:Trypanosoma vivax / Q000235:genetics / Q000276:immunology*; D014354:Trypanosomiasis, Bovine / Q000097:blood / Q000175:diagnosis*; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000097:blood* / Q000737:chemistry / Q000235:genetics / Q000276:immunology
chemical_list: D014643:Variant Surface Glycoproteins, Trypanosoma