title: The population structure of drug-resistant Mycobacterium tuberculosis clinical isolates from Sichuan in China.
abstract: China ranks second next to India among 22 high-burden countries despite decades' effort on tuberculosis (TB) control. The Sichuan province today contains the second-largest number of TB cases among Chinese provinces, where the prevalence of drug-resistant TB, especially MDR-TB, is much higher than the average level in eastern China. In this study, the population structure and the transmission characteristics of drug-resistant TB in Sichuan province were studied by spoligotyping and 24-locus Mycobacterial interspersed repetitive units-variable number tandem DNA repeats (MIRU-VNTR), applied to a total of 306 clinical isolates. Spoligotyping-based analysis showed that Beijing family represented 69.28% of all isolates and constituted the largest group (66.24%) of MDR-TB in Sichuan. The remaining isolates, accounting for 33.76% of MDR isolates, belonged to the ill-defined T family, Manu2, H3, LAM9, and other minor unassigned clades. The discriminatory power evaluated for spoligotyping was poor (HGI=0.595), but high for 24-locus MIRU-VNTRs (HGI=0.999). The number of the most discriminatory loci (h>0.6) was 12, including locus 424, 802, 960, 1644, 1955, 2163b, 2996, 3007, 3192, 3690, 4348 and 4052. It was concluded that 24-locus MIRU-VNTRs could be a more discriminatory tool for differentiating clinical isolates from Sichuan region. The small clustering size obtained from the current population structure analysis suggested that the high prevalence of drug-resistant TB in this region might be attributed partially to the acquired resistance due to inappropriate drug use rather than active transmission of drug-resistant TB (primary resistance).
authors: Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, PR China.
authors: Yuding
authors: Y
authors: Zhao
authors: Qin
authors: Q
authors: Feng
authors: Ke
authors: K
authors: Tang
authors: Congcong
authors: C
authors: Zhang
authors: Honghu
authors: H
authors: Sun
authors: Tao
authors: T
authors: Luo
authors: Zhirong
authors: Z
authors: Yang
authors: David
authors: D
authors: Couvin
authors: Nalin
authors: N
authors: Rastogi
authors: Qun
authors: Q
authors: Sun
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015373:Bacterial Typing Techniques; D002648:Child; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D004269:DNA, Bacterial; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D058885:Multilocus Sequence Typing; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology / Q000382:microbiology*; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial