title: Genetic diversity and dynamic distribution of Mycobacterium tuberculosis isolates causing pulmonary and extrapulmonary tuberculosis in Thailand.
abstract: This study examined the genetic diversity and dynamicity of circulating Mycobacterium tuberculosis strains in Thailand using nearly neutral molecular markers. The single nucleotide polymorphism (SNP)-based genotypes of 1,414 culture-positive M. tuberculosis isolates from 1,282 pulmonary tuberculosis (PTB) and 132 extrapulmonary TB (EPTB) patients collected from 1995 to 2011 were characterized. Among the eight SNP cluster groups (SCG), SCG2 (44.1%), which included the Beijing (BJ) genotype, and SCG1 (39.4%), an East African Indian genotype, were dominant. Comparisons between the genotypes of M. tuberculosis isolates causing PTB and EPTB in HIV-negative cases revealed similar prevalence trends although genetic diversity was higher in the PTB patients. The identification of 10 reported sequence types (STs) and three novel STs was hypothesized to indicate preferential expansion of the SCG2 genotype, especially the modern BJ ST10 (15.6%) and ancestral BJ ST19 (13.1%). An association between SCG2 and SCG1 genotypes and particular patient age groups implies the existence of different genetic advantages among the bacterial populations. The results revealed that increasing numbers of young patients were infected with M. tuberculosis SCGs 2 and 5, which contrasts with the reduction of the SCG1 genotype. Our results indicate the selection and dissemination of potent M. tuberculosis genotypes in this population. The determination of heterogeneity and dynamic population changes of circulating M. tuberculosis strains in countries using the Mycobacterium bovis BCG (bacillus Calmette-Guérin) vaccine are beneficial for vaccine development and control strategies.
authors.affiliation: Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Prapaporn
authors.initials: P
authors.lastname: Srilohasin
authors.affiliation: Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand angkana.cha@mahidol.ac.th.
authors.forename: Angkana
authors.initials: A
authors.lastname: Chaiprasert
authors.affiliation: Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Katsushi
authors.initials: K
authors.lastname: Tokunaga
authors.affiliation: Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
authors.forename: Nao
authors.initials: N
authors.lastname: Nishida
authors.affiliation: National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Ministry of Science and Technology, Pathum Thani, Thailand.
authors.forename: Therdsak
authors.initials: T
authors.lastname: Prammananan
authors.affiliation: National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Ministry of Science and Technology, Pathum Thani, Thailand.
authors.forename: Nat
authors.initials: N
authors.lastname: Smittipat
authors.affiliation: Medical Genetics Section, National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi, Thailand.
authors.forename: Surakameth
authors.initials: S
authors.lastname: Mahasirimongkol
authors.affiliation: TB/HIV Research Project, Research Institute of Tuberculosis, Chiang Rai, Thailand.
authors.forename: Boonchai
authors.initials: B
authors.lastname: Chaiyasirinroje
authors.affiliation: TB/HIV Research Project, Research Institute of Tuberculosis, Chiang Rai, Thailand Fukujuji Hospital, Japan Anti-Tuberculosis Association, Kiyose, Tokyo, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Yanai
authors.affiliation: Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Prasit
authors.initials: P
authors.lastname: Palittapongarnpim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence; D013785:Thailand / Q000453:epidemiology; D014376:Tuberculosis / Q000453:epidemiology* / Q000382:microbiology*; D055815:Young Adult