Identification of novel mutations associated with cycloserine resistance in Mycobacterium tuberculosis
Identification of novel mutations associated with cycloserine resistance in Mycobacterium tuberculosis
复制标题
结核分枝杆菌中与环丝氨酸抗性相关的新突变的鉴定。
DOI：
10.1093/jac/dkx316
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发表时间：
2017-12-01
影响因子：
5.2
通讯作者：
Zhang, Ying
中科院分区：
文献类型：
--
作者：
Chen, Jiazhen;Zhang, Shuo;Zhang, Ying
目的：D-胞糖碱是用于治疗MDR-和XDR-TB的重要二线药物。然而，对D-胞丝苷的抗性机制尚不清楚。在这里，我们使用体外脱离的抗药性突变体研究了D-胞丝苷耐药的分子基础。方法：结核分枝杆菌H37RV在7H11琼脂平板上进行突变体选择，其中含有不同浓度的D-蛋白酶。总共分离了18个抗糖烯耐药突变体并遭受WGS。通过PCR和Sanger测序证实了与D-胞克氨耐药耐药性相关的鉴定突变。分析：我们在16个基因中鉴定了与D-胞克氏菌抗性相关的突变。有趣的是，我们仅在编码丙氨酸种族酶的ALR（RV3423C）中发现了突变，但在其他已知的D-胞与甲烯耐药相关基因（例如DDL，CYCA或ALD）中却没有发现突变。取而代之的是，我们确定了13个新基因[RV0059，BETP（RV0917），RV0221，RV1403C，RV1683，RV1726，RV1726，GABD2（RV1731），RV2749，SUGI（RV33331），RV3331），Hisc2（Rv3331），RV3772（RV3772） RV1435C和RV0759C]的30个区域，其具有与D-环丝氨酸耐药性相关的独奏突变。我们的发现表明，D-胞丝氨耐药耐药的机制比以前认为的更为复杂，并且涉及参与不同细胞功能的基因，例如脂质代谢，甲基转移酶，压力反应和运输系统。结论：与D-不同基因相关的新突变。已经确定了环丝氨酸的耐药性，它为D-胞与甲烯的作用机理和抗性机理开发了新的启示。需要未来的研究来验证临床菌株中的这些发现，以便可以开发出D-胞丝苷耐药性以改善MDR-TB治疗的分子检测。
Objectives: D-Cycloserine is an important second-line drug used to treat MDR- and XDR-TB. However, the mechanisms of resistance to D-cycloserine are not well understood. Here we investigated the molecular basis of D-cycloserine resistance using in vitro-isolated resistant mutants.Methods: Mycobacterium tuberculosis H37Rv was subjected to mutant selection on 7H11 agar plates containing varying concentrations of D-cycloserine. A total of 18 D-cycloserine-resistant mutants were isolated and subjected to WGS. The identified mutations associated with D-cycloserine resistance were confirmed by PCR and Sanger sequencing.Results: We identified mutations in 16 genes that are associated with D-cycloserine resistance. Interestingly, we found mutations only in alr (rv3423c) encoding alanine racemase, but not in other known D-cycloserine resistance-associated genes such as ddl, cycA or ald. Instead, we identified 13 new genes [rv0059, betP (rv0917), rv0221, rv1403c, rv1683, rv1726, gabD2 (rv1731), rv2749, sugI (rv3331), hisC2 (rv3772), the 50 intergenic region of rv3345c and rv1435c, and the 30 region of rv0759c] that had solo mutations associated with D-cycloserine resistance. Our findings indicate that the mechanisms of D-cycloserine resistance are more complex than previously thought and involve genes participating in different cellular functions such as lipid metabolism, methyltransferase, the stress response and transport systems.Conclusions: New mutations in diverse genes associated with D-cycloserine resistance have been identified that shed new light on the mechanisms of action and resistance of D-cycloserine. Future studies are needed to verify these findings in clinical strains so that molecular detection of D-cycloserine resistance for improved treatment of MDR-TB can be developed.