Department of Respiratory and Critical Care Medicine, the Third Affiliated Hospital of Shandong First Medical University, Jinan, Shandong, PR China.
Institute of Nutrition and Health, School of Public Health, Qingdao University, Qingdao, PR China.
Int J Infect Dis. 2024 Mar;140:124-131. doi: 10.1016/j.ijid.2023.10.015. Epub 2023 Oct 19.
This study aimed to describe the lineage-specific transmissibility and epidemiological migration of Mycobacterium tuberculosis in China.
We curated a large set of whole-genome sequences from 3204 M. tuberculosis isolates, including thousands of newly sequenced genomes, and applied a series of metrics to compare the transmissibility of M. tuberculosis strains between lineages and sublineages. The countrywide transmission patterns of major lineages were explored.
We found that lineage 2 (L2) was the most prevalent lineage in China (85.7%), with the major sublineage 2.2.1 (80.9%), followed by lineage 4 (L4) (13.8%), which comprises major sublineages 4.2 (1.5%), 4.4 (6.2%) and 4.5 (5.8%). We showed evidence for frequent cross-regional spread and large cluster formation of L2.2.1 strains, whereas L4 strains were relatively geographically restricted in China. Next, we applied a series of genomic indices to evaluate M. tuberculosis strain transmissibility and uncovered higher transmissibility of L2.2.1 compared with the L2.2.2 and L4 sublineages. Phylogeographic analysis showed that southern, eastern, and northern China were highly connected regions for countrywide L2.2.1 strain spread.
The present study provides insights into the different transmission and migration patterns of the major M. tuberculosis lineages in China and highlights that transmissible L2.2.1 is a threat to tuberculosis control.
本研究旨在描述中国结核分枝杆菌（Mycobacterium tuberculosis）谱系特异性的传染性和流行病学传播。
我们整理了来自 3204 株结核分枝杆菌分离株的大量全基因组序列，包括数千个新测序的基因组，并应用一系列指标比较了谱系和亚谱系之间结核分枝杆菌菌株的传染性。探索了主要谱系在中国的全国传播模式。
我们发现谱系 2（L2）在中国最为流行（85.7%），主要亚谱系 2.2.1（80.9%），其次是谱系 4（L4）（13.8%），其包括主要亚谱系 4.2（1.5%）、4.4（6.2%）和 4.5（5.8%）。我们有证据表明 L2.2.1 菌株经常发生跨区域传播和大型簇形成，而 L4 菌株在中国的分布相对局限。接下来，我们应用一系列基因组指标评估结核分枝杆菌菌株的传染性，发现 L2.2.1 比 L2.2.2 和 L4 亚谱系具有更高的传染性。系统地理学分析表明，中国南部、东部和北部是 L2.2.1 菌株全国传播的高度连接区域。
本研究提供了对中国主要结核分枝杆菌谱系不同传播和迁移模式的深入了解，并强调了可传播的 L2.2.1 对结核病控制构成威胁。
