title: Phylogenetic analysis of spotted fever group Rickettsiae isolated from ticks in Japan.
abstract: Eight spotted fever group (SFG) rickettsiae isolated from ticks in Japan were classified by phylogenetic analysis based on the nucleotide sequences of both the citrate synthase-encoding gene (gltA) and 190-kDa antigen-encoding gene (rOmpA). In the phylogenetic tree of gltA, strains DT-1 and FLA-1 isolated from the Dermacentor taiwanensis and Haemaphysalis frava ticks, respectively, were placed as Rickettsia japonica, and strains IO-1, IO-2, IO-25, IM-1 and IP-2 from genus Ixodes ticks were placed as Rickettsia helvetica. Strain AT-1 isolated from the Amblyomma testudinarium belonged to the cluster including Rickettsia akari, Rickettsia australis and Rickettsia felis. In the phylogenetic tree of the rOmpA, strains DT-1 and FLA-1 were placed as R. japonica, and strain AT-1 belonged to the cluster including Rickettsia cooleyi and the symbiont of Ixodes scapularis. The rOmpA fragments of 5 Ixodes isolates could not be amplified by PCR. The present study showed that strains DT-1 and FLA-1 were genotypically identical to R. japonica, and 5 Ixodes isolates were associated with the R. helvetica. Based on previous genotypic and antigenic data, and the phylogenetic analysis presented here, strain AT-1 should be considered as a new species among SFG rickettsiae.
authors.affiliation: Toyama Institute of Health, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Ishikura
authors.forename: Hiromi
authors.initials: H
authors.lastname: Fujita
authors.forename: Shuji
authors.initials: S
authors.lastname: Ando
authors.forename: Kumiko
authors.initials: K
authors.lastname: Matsuura
authors.forename: Mamoru
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D002950:Citrate (si)-Synthase / Q000235:genetics; D004283:Dog Diseases / Q000382:microbiology; D004285:Dogs; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D012281:Rickettsia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D017386:Sequence Homology, Amino Acid; D013987:Ticks / Q000145:classification / Q000382:microbiology*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C080205:rOmpA, Rickettsia; D002950:Citrate (si)-Synthase