Hu Xinling, Zhou Xintong, Yin Tong, Chen Keyu, Hu Yongfei, Zhu Baoli, Mi Kaixia
CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
Savaid Medical School, University of Chinese Academy of Sciences, Beijing 101408, China.
Antibiotics (Basel). 2021 Oct 29;10(11):1323. doi: 10.3390/antibiotics10111323.
Tuberculosis, caused by the pathogen , is a serious infectious disease worldwide. Multidrug-resistant TB (MDR-TB) remains a global problem, and the understanding of this resistance is incomplete. Studies suggested that DNA methylation promotes bacterial adaptability to antibiotic treatment, but the role of mycobacterial HsdM in drug susceptibility has not been explored. Here, we constructed an inactivated (BCG) strain, Δ. Δ shows growth advantages over wild-type BCG under isoniazid treatment and hypoxia-induced stress. Using high-precision PacBio single-molecule real-time sequencing to compare the Δ and BCG methylomes, we identified 219 methylated HsdM substrates. Bioinformatics analysis showed that most HsdM-modified genes were enriched in respiration- and energy-related pathways. qPCR showed that HsdM-modified genes directly affected their own transcription, indicating an altered redox regulation. The use of the latent Wayne model revealed that Δ had growth advantages over wild-type BCG and that HsdM regulated mRNA levels, which may be crucial in regulating transition from latency to reactivation. We found that HsdM regulated corresponding transcription levels via gene methylation; thus, altering the mycobacterial redox status and decreasing the bacterial susceptibility to isoniazid, which is closely correlated with the redox status. Our results provide valuable insight into DNA methylation on drug susceptibility.
由该病原体引起的结核病是全球范围内一种严重的传染病。耐多药结核病（MDR-TB）仍然是一个全球性问题，而且对这种耐药性的了解并不完整。研究表明，DNA甲基化促进细菌对抗生素治疗的适应性，但分枝杆菌HsdM在药物敏感性方面的作用尚未得到探索。在此，我们构建了一株灭活的（卡介苗）菌株，Δ。在异烟肼治疗和缺氧诱导的应激条件下，Δ比野生型卡介苗具有生长优势。利用高精度的PacBio单分子实时测序技术比较Δ和卡介苗的甲基化组，我们鉴定出219个甲基化的HsdM底物。生物信息学分析表明，大多数HsdM修饰的基因富集于呼吸和能量相关途径。定量PCR显示，HsdM修饰的基因直接影响其自身转录，表明氧化还原调节发生改变。使用潜伏韦恩模型显示，Δ比野生型卡介苗具有生长优势，且HsdM调节mRNA水平，这在调节从潜伏到再激活的转变中可能至关重要。我们发现HsdM通过基因甲基化调节相应的转录水平；因此，改变了分枝杆菌的氧化还原状态并降低了细菌对异烟肼的敏感性，而异烟肼敏感性与氧化还原状态密切相关。我们的研究结果为DNA甲基化对药物敏感性的影响提供了有价值的见解。
