title: Phylogenetic clustering of 4 prevalent virulence genes in Orientia tsutsugamushi isolates from human patients.
abstract: The pathogenicity of microbes is involved in many kinds of virulence genes. The relationships between these virulence genes and strains are not clear in Orientia tsutsugamushi yet. In this study, we confirmed the presence of the virulence genes and classified into O. tsutsugamushi isolates using phylogenetic analysis of the virulence genes. We also compared the fatality rates of every isolate via an infection experiment in BALB/c mice using the O. tsutsugamushi isolates, Deajeon03-01, Wonju03-01, and Muju03-01. Moreover, we compared the phylogenetic analysis, in basis with 56 kDa protein sequence which determined from serotype, and virulence genes of O. tsutsugamushi. Our results showed remarkably different fatality rates between Deajeon03-01 and Muju03-01, which are both Boryong strains of O. tsutsugamushi. Also, clustering analyses including these two isolates gave slightly different results depending on whether they were clustered based on virulence genes or on the 56 kDa protein sequences. Consequently, we conclude that fatality rates in O. tsutsugamushi are correlated with differences in both serotypes and virulence genes. We identified some variations within the virulence genes dnaA, virB8, tolR, and trxA among the isolates.
authors.affiliation: Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Seoul, Republic of Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Chu
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Park
authors.forename: Eun-Ju
authors.initials: EJ
authors.lastname: Kim
authors.forename: Kyu-Jam
authors.initials: KJ
authors.lastname: Hwang
authors.forename: Soo-Kyoung
authors.initials: SK
authors.lastname: Shim
authors.forename: Sungdo
authors.initials: S
authors.lastname: Park
authors.forename: Mi-Yeoun
authors.initials: MY
authors.lastname: Park
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D016000:Cluster Analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D012285:Orientia tsutsugamushi / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D010802:Phylogeny; D012612:Scrub Typhus / Q000382:microbiology; D016415:Sequence Alignment; D016019:Survival Analysis; D013879:Thioredoxins / Q000235:genetics; D014774:Virulence / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; D008565:Membrane Proteins; D013879:Thioredoxins