title: Molecular identification and phylogenetic relationships of trichomonad isolates of galliform birds inferred from nuclear small subunit rRNA gene sequences.
abstract: Histomonas meleagridis is the etiological agent of histomonosis or blackhead disease. Recently, genotyping, based on polymerase chain reaction and sequencing of internal transcribed spacer-1 sequences was applied to various isolates originating from fowl. Three genotypes were described: types I and II isolates were associated with clinical disease and probably derived from H. meleagridis, whereas, type III isolates were not disease-associated and likely corresponded to Parahistomonas wenrichi according to morphological observations. However, this latter species has never been characterized at the molecular level and its phylogenetic relationships with other parabasalids remained hypothetical. To confirm the identification of these isolates, small subunit rRNA gene sequences were obtained from representatives of types I, II, and III and analyzed in a broad phylogeny including 64 other parabasalid sequences. From our phylogenetic trees, we confirmed that types I and II isolates were closely related, if not identical, to H. meleagridis, while type III isolates represented P. wenrichi. Both species clustered together with high support. This grouping suggested that speciation leading to these two species inhabiting the same hosts and ecological niche occurred recently in birds. In addition, speciation was likely followed by loss of pathogenicity in P. wenrichi.
authors.affiliation: Inserm, U547, Institut Pasteur de Lille, Université Lille Nord de France, 1 rue du Professeur Calmette, BP 245, 59019, Lille cedex, France.
authors.forename: Cléa
authors.initials: C
authors.lastname: Mantini
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Dalia-Cornette
authors.forename: Satoko
authors.initials: S
authors.lastname: Noda
authors.forename: Harold M J F
authors.initials: HM
authors.lastname: Van Der Heijden
authors.forename: Monique
authors.initials: M
authors.lastname: Capron
authors.forename: Eduardo
authors.initials: E
authors.lastname: Dei-Cas
authors.forename: Wil J M
authors.initials: WJ
authors.lastname: Landman
authors.forename: Moriya
authors.initials: M
authors.lastname: Ohkuma
authors.forename: Eric
authors.initials: E
authors.lastname: Viscogliosi
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000469:parasitology*; D001717:Birds / Q000469:parasitology*; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D056900:Parabasalidea / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D011529:Protozoan Infections, Animal / Q000469:parasitology*; D016053:RNA, Protozoan / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D016053:RNA, Protozoan; D012337:RNA, Ribosomal, 18S