title: [Sequence analysis subtyping of the 56-kDa protein-encoding gene of Karp-type Orientia tsutsugamushi isolated in scrub typhus cases].
abstract: To determine the Karp-type Orientia tsutsugamushi subtype in northern Japan, i.e., Yamagata, Niigata, and Akita Prefectures, we analyzed the partial nucleotide sequence of the 56-kDa protein-encoding gene of 30 isolates from scrub typhus cases. Based on sequencing results, we classified isolates into two groups of 27 and 3 isolates. Nucleotide sequences of 27 isolates were homologous to the yeo-joo strain, classified as a JP-1 subtype. The three isolates were each homologous to a stain of CMM1, KNP1, or KNP2, classified as JP-2 subtypes. Phylogenetic tree analysis showed the 27 isolates forming a cluster with the yeo-joo strain and the three isolates with the CMM, KNP1, and KNP2 strains and therefore belonging to these subtypes. The Karp-type O. tsutsugamushi JP-2 subtype predominates in Japan, the JP-1 subtype probably the predominates in the area investigated. O. tsutsugamushi JP-1 subtype strains must therefore be isolated from subjects in this area and comprehensively studied.
authors.affiliation: Yamagata Prefectural Institute of Public Health.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kaneko
authors.forename: Junji
authors.initials: J
authors.lastname: Seto
authors.forename: Toshiya
authors.initials: T
authors.lastname: Aoki
authors.forename: Katsumi
authors.initials: K
authors.lastname: Otani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D012285:Orientia tsutsugamushi / Q000145:classification* / Q000235:genetics; D012612:Scrub Typhus / Q000382:microbiology*
chemical_list: C080442:56 kDa antigen, Rickettsia; D000942:Antigens, Bacterial; D001426:Bacterial Proteins