title: Isolation and identification of a novel spotted fever group rickettsia, strain IG-1, from Ixodes granulatus ticks collected on Orchid Island (Lanyu), Taiwan.
abstract: A novel species of spotted fever group (SFG) rickettsia, Rickettsia spp. IG-1, was identified and isolated from adult Ixodes granulatus ticks collected from Orchid Island (Lanyu), an islet located in southeastern Taiwan. Serum samples collected from the rodent host Rattus losea and SFG-positive human serum reacted with IG-1 using an immunofluorescence assay (IFA). Pairwise nucleotide sequence analysis of 16S rRNA (rrs), gltA, ompA, ompB, and sca4 shows that IG-1 belongs to SFG rickettsiae and had the highest nucleotide sequence similarities to Rickettsia slovaca and R. sibirica. Phylogenetic analysis of the ompA, ompB genes and sca4 shows that IG-1 is most closely related to R. honei. The results showed the sequence divergence of this novel isolate from those rickettsiae previously characterized using the criteria proposed by Fournier and others. Whether IG-1 is pathogenic for humans remains to be studied.
authors.affiliation: Research and Diagnostic Center, Centers for Disease Control, Department of Health, Taipei, Taiwan, Republic of China.
authors.forename: Kun-Hsien
authors.initials: KH
authors.lastname: Tsai
authors.forename: Hsi-Chieh
authors.initials: HC
authors.lastname: Wang
authors.forename: Chun-Hsien
authors.initials: CH
authors.lastname: Chen
authors.forename: Jyh-Hsiung
authors.initials: JH
authors.lastname: Huang
authors.forename: Hsiu-Ying
authors.initials: HY
authors.lastname: Lu
authors.forename: Chien-Ling
authors.initials: CL
authors.lastname: Su
authors.forename: Pei-Yun
authors.initials: PY
authors.lastname: Shu
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002460:Cell Line; D017753:Ecosystem; D005260:Female; D005843:Geography; D018884:Ixodes / Q000382:microbiology*; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D051381:Rats; D012281:Rickettsia / Q000145:classification* / Q000302:isolation & purification*; D013624:Taiwan
chemical_list: D001426:Bacterial Proteins