揭示耻垢分枝杆菌对利奈唑胺耐药性的遗传因素：来自转座子文库的见解
Unravelling the genetic contributors to linezolid resistance in Mycobacterium smegmatis: insights from a transposon library.
作者信息
Lin Dachuan, Zhang Yuanyi, Luo Zhifei, Wang Jing, Chen Xinchun
机构信息
Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, School of Basic Medicine and Life Sciences, Hainan Medical University, Haikou, China.
Guangdong Key Laboratory of Regional Immunity and Diseases, Shenzhen University School of Medicine, Shenzhen University, Shenzhen, China.
出版信息
J Antimicrob Chemother. 2025 Jun 3;80(6):1595-1603. doi: 10.1093/jac/dkaf106.
OBJECTIVES
This study aimed to identify and characterize genes associated with linezolid resistance in Mycobacterium smegmatis using a transposon mutagenesis approach.
METHODS
This research conducted three replicative experiments where 16 isolates displaying pronounced resistance to linezolid were examined, revealing two distinct morphologies. WGS was employed to investigate these isolates, uncovering mutations in specific genes. The binding affinity of linezolid to relevant proteins was assessed through molecular docking studies and validated by drug affinity responsive target stability (DARTS) assays.
RESULTS
Complementation of the mspA gene in mutant strains restored linezolid susceptibility, but the Ala127Gln substitution in MSMEG_0965 did not, suggesting a critical role of this residue in resistance. Further investigations revealed that the resistance mechanism in the △MSMEG_0965 mutant involves impaired linezolid uptake.
CONCLUSIONS
The research successfully identified two genes, MSMEG_4189 and MSMEG_0965, associated with linezolid resistance in M. smegmatis. It also elucidated the role of MSMEG_0965 in the resistance mechanism, providing significant targets and reference points for future studies on clinical strains.
目的
本研究旨在利用转座子诱变方法鉴定耻垢分枝杆菌中与利奈唑胺耐药相关的基因并对其进行表征。
方法
本研究进行了三个重复实验，检测了16株对利奈唑胺表现出显著耐药性的菌株，发现了两种不同的形态。采用全基因组测序（WGS）对这些菌株进行研究，发现特定基因中的突变。通过分子对接研究评估利奈唑胺与相关蛋白质的结合亲和力，并通过药物亲和力响应靶点稳定性（DARTS）分析进行验证。
结果
突变菌株中mspA基因的互补恢复了对利奈唑胺的敏感性，但MSMEG_0965中的Ala127Gln替换并未恢复，这表明该残基在耐药性中起关键作用。进一步研究表明，△MSMEG_0965突变体的耐药机制涉及利奈唑胺摄取受损。
结论
该研究成功鉴定了两个与耻垢分枝杆菌利奈唑胺耐药相关的基因，即MSMEG_4189和MSMEG_0965。它还阐明了MSMEG_0965在耐药机制中的作用，为未来临床菌株的研究提供了重要的靶点和参考点。
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