title: Comparative analysis of Mycobacterium tuberculosis Beijing strains isolated in three remote areas of Japan.
abstract: A quantitative and qualitative comparison was carried out of Mycobacterium tuberculosis Beijing strains isolated in three remote areas of Japan. A total of 452 strains from Chiba Prefecture, 75 from Yamagata Prefecture, and 315 from Kobe City were analyzed for 24 loci by variable number of tandem repeats typing (24(Beijing)-VNTR). All strains were classified in six Beijing subgroups (B(SUB)), B1 to B5 and T, based on a minimum spanning tree reconstructed using data of a standard set of 15 VNTR loci. No significant difference was found in the distribution of strains in the B(SUB) in the three areas, with one exception due to a B5 outbreak in Yamagata, indicating no significant quantitative difference in the B(SUB) in the three areas (P<0.01, Chi-square test). In addition, when strains in each B(SUB) isolated in the three areas were mixed and standardized index of association (I(A)(s)) and variance (Φ(PT)) values were calculated, no significant qualitative difference in the B(SUB) in the three areas was found. These results suggested that the B(SUB) diverged prior to the introduction of M. tuberculosis Beijing strains into Japan. Differences in the distribution of strains in each B(SUB) between Japan and continental Asian countries suggested there had been genetic drift in the continental Asian countries in which B4 had been dominant.
authors.affiliation: Division of Bacteriology, Chiba Prefectural Institute of Public Health, Chiba, Japan. Electronic address: e.ykym@pref.chiba.lg.jp.
authors.forename: Eiji
authors.initials: E
authors.lastname: Yokoyama
authors.affiliation: Division of Bacteriology, Chiba Prefectural Institute of Public Health, Chiba, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Hachisu
authors.affiliation: Department of Infectious Disease, Kobe Institute of Health, Hyogo, Japan.
authors.forename: Tomotada
authors.initials: T
authors.lastname: Iwamoto
authors.affiliation: Department of Infectious Disease, Kobe Institute of Health, Hyogo, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakanishi
authors.affiliation: Department of Infectious Disease, Kobe Institute of Health, Hyogo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Arikawa
authors.affiliation: Department of International Health, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Wada
authors.affiliation: Department of Microbiology, Yamagata Prefectural Institute of Public Health, Yamagata, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Seto
authors.affiliation: Division of Bacteriology, Chiba Prefectural Institute of Public Health, Chiba, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kishida
mesh_terms: D005798:Genes, Bacterial; D006801:Humans; D007564:Japan; D018598:Minisatellite Repeats; D058889:Molecular Typing; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D012424:Rural Population; D017422:Sequence Analysis, DNA; D014397:Tuberculosis, Pulmonary / Q000382:microbiology*
keywords: Beijing subgroup; Genetic diversity; Mycobacterium tuberculosis; Population genetics