First Insight into the Genotypic Diversity of Clinical Mycobacterium tuberculosis Isolates from Gansu Province, China

Abstract

BackgroundInvestigations of Mycobacterium tuberculosis genetic diversity in China have indicated a significant regional distribution. The aim of this study was to characterize the genotypes of clinical M. tuberculosis isolates obtained from Gansu, which has a special geographic location in China.Methodology/Principal FindingsA total of 467 clinical M. tuberculosis strains isolated in Gansu Province were genotyped by 15-locus mycobacterial interspersed repetitive units–variable number tandem repeats (MIRU-VNTR) and spoligotyping. The results showed that 445 isolates belonged to six known spoligotype lineages, whereas 22 isolates were unknown. The Beijing genotype was the most prevalent (87.58%, n = 409), while the shared type 1 was the dominant genotype (80.94%, n = 378). The second most common lineage was the T lineage, with 25 isolates (5.35%), followed by the H lineage with 5 isolates (1.07%), the MANU family (0.64%, 3 isolates), the U family (0.43%, 2 isolates) and the CAS lineage with 1 isolate (0.21%). By using the VNTR15China method, we observed 15 groups and 228 genotypes among the 467 isolates. We found no association between the five larger groups (including the Beijing genotype) and sex, age, or treatment status, and there was no noticeable difference in the group analysis in different areas. In the present study, seven of the 15 MIRU-VNTR loci were highly or moderately discriminative according to their Hunter-Gaston discriminatory index.Conclusions/SignificanceThe Beijing genotype is the predominant genotype in Gansu province. We confirm that VNTR15China is suitable for typing Beijing strains in China and that it has a better discriminatory power than spoligotyping. Therefore, the use of both methods is the most suitable for genotyping analysis of M. tuberculosis.

Genotypic characteristics ofMycobacterium tuberculosiscirculating in Xinjiang, China

“…In previous studies, the predominance of the Beijing/W genotype in China has been well described. The proportion of Beijing/W lineage strain infections has been reported to be 91.82% in Beijing [20], with similar predominance in provinces that neighbor Xinjiang [21,22] (69.34% in Sichuan, 96.3% in Tibet, 87.58% in Gansu, and 93.26% in Inner Mongolia). However, the Beijing/W lineage is less prevalent in countries that neighbor Xinjiang (6.09% in Russia [23], 50% in Mongolia [4], and 6% in Pakistan [24]).…”

Genetic diversity and drug resistance of Mycobacterium tuberculosis in Yunnan, China

“…However, a strain belonging to the CAS lineage was first identified in this study. The mainly prevalent region of the CAS family was India, which was also reported in Tibet, Xinjiang, Jiangsu, and Gansu in China. The transmission way of CAS MTB strain into Yunnan remains unclear.…”

A First Insight into the Genetic Diversity and Drug Susceptibility Pattern of Mycobacterium tuberculosis Complex in Zhejiang, China

“…Although the prevalence of Beijing genotype among most of northern regions was higher than 75%, we also found that Beijing genotype only accounted for 57.3% of MTB isolates in Xinjiang Uygur Autonomous Region [14]. In southern China, the prevalence of Beijing family in Zhejiang (71.6%) was lower than that in Jiangsu (80.5%) [16], Shanghai (79.3%) [17], and Jiangxi (76.7%) [18], while it was higher than that in Chongqing (66.7%) [20], Guangxi (61.9%) [21], Fujian (57.3%) [22], and Guizhou (54.0%) [6–13, 15, 19, 23] (Table 4). …”