Evolution of multidrug resistance during Staphylococcus aureus infection involves mutation of the essential two component regulator WalKR.
Evolution of multidrug resistance during Staphylococcus aureus infection involves mutation of the essential two component regulator WalKR.
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DOI：
10.1371/journal.ppat.1002359
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发表时间：
2011-11
期刊：
影响因子：
6.7
通讯作者：
Stinear TP
中科院分区：
文献类型：
--
作者：
Howden BP;McEvoy CR;Allen DL;Chua K;Gao W;Harrison PF;Bell J;Coombs G;Bennett-Wood V;Porter JL;Robins-Browne R;Davies JK;Seemann T;Stinear TP
金黄色葡萄球菌的抗菌药物耐药性是一个主要的公共卫生威胁，而且对万古霉素和达托霉素（这两种最后一线抗菌药物）产生耐药性的菌株的出现加剧了这一威胁。在这里，我们对五对临床对万古霉素敏感 (VSSA) 和万古霉素中间 ST239 金黄色葡萄球菌 (VISA) 进行了高通量 DNA 测序和比较基因组学；每对在万古霉素治疗失败之前和之后均被隔离。这些比较揭示了 VISA 菌株中参与细胞壁代谢控制的基本 walKR 双组分调节位点内的常见突变模式。然后，我们在临床 VSSA 和 VISA 菌株中进行了双向等位基因交换实验，结果表明 walK 或 walR 内的单核苷酸取代会导致对万古霉素和达托霉素的共耐药性，并导致在耐药临床分离株中观察到的典型细胞壁增厚。 Ion Torrent 基因组测序证实，在等位基因交换过程中，walR 或 walK VISA 突变体中没有引入额外的调节突变。然而，在 walK 突变体的假定转运基因中检测到了两个潜在的补偿突变。 walK 或 walR 中最小的遗传变化也会减弱毒力，减少生物膜形成，并导致一致的转录变化，这表明该调节剂在控制中枢代谢中发挥着重要作用。这项研究强调了持续性金黄色葡萄球菌感染期间出现的单一突变的巨大影响，并证明了 walKR 在增加耐药性、控制代谢和改变这种病原体的毒力潜力方面所发挥的作用。由于抗生素耐药性的发展，金黄色葡萄球菌引起的严重感染的治疗变得复杂，最近还出现了对治疗耐药金黄色葡萄球菌感染的最后可用抗生素之一万古霉素的耐药性。在这里，我们使用 10 个金黄色葡萄球菌菌株的全基因组测序和对持续血流感染期间获得的连续金黄色葡萄球菌分离株进行基因替换实验，展示了金黄色葡萄球菌如何通过获得重要调节因子 WalKR 的突变而进化出中间万古霉素耐药性。发现该基因座的突变在表现出中等万古霉素耐药性的金黄色葡萄球菌菌株中很常见，并且这些菌株也表现出对达托霉素不敏感，即使这种药物从未用于治疗。将突变的 walK 或 walR 替换为亲本菌株的实验证实了这些突变导致了抗生素耐药性，但也导致了毒力、生物膜形成和生物体内代谢调节的显着变化。这项研究强调了金黄色葡萄球菌面对抗菌治疗的适应性。
Antimicrobial resistance in Staphylococcus aureus is a major public health threat, compounded by emergence of strains with resistance to vancomycin and daptomycin, both last line antimicrobials. Here we have performed high throughput DNA sequencing and comparative genomics for five clinical pairs of vancomycin-susceptible (VSSA) and vancomycin-intermediate ST239 S. aureus (VISA); each pair isolated before and after vancomycin treatment failure. These comparisons revealed a frequent pattern of mutation among the VISA strains within the essential walKR two-component regulatory locus involved in control of cell wall metabolism. We then conducted bi-directional allelic exchange experiments in our clinical VSSA and VISA strains and showed that single nucleotide substitutions within either walK or walR lead to co-resistance to vancomycin and daptomycin, and caused the typical cell wall thickening observed in resistant clinical isolates. Ion Torrent genome sequencing confirmed no additional regulatory mutations had been introduced into either the walR or walK VISA mutants during the allelic exchange process. However, two potential compensatory mutations were detected within putative transport genes for the walK mutant. The minimal genetic changes in either walK or walR also attenuated virulence, reduced biofilm formation, and led to consistent transcriptional changes that suggest an important role for this regulator in control of central metabolism. This study highlights the dramatic impacts of single mutations that arise during persistent S. aureus infections and demonstrates the role played by walKR to increase drug resistance, control metabolism and alter the virulence potential of this pathogen. The treatment of serious infections caused by Staphylococcus aureus is complicated by the development of antibiotic resistance, and recently resistance to one of the last available antibiotics to treat resistant S. aureus infections, vancomycin, has also emerged. Here we have shown using whole genome sequencing of 10 S. aureus strains and gene replacement experiments on sequential S. aureus isolates obtained during persistent bloodstream infection, how S. aureus evolved intermediate vancomycin resistance by acquiring mutations in the important regulator WalKR. Mutations in this locus were found to be common in strains of S. aureus demonstrating intermediate vancomycin resistance, and these strains also demonstrated daptomycin non-susceptibility even though this drug had never been used for treatment. Experiments to replace the mutated walK or walR into the parent strain and vice versa confirmed that these mutations were responsible for the antibiotic resistance, but also led to significant changes in virulence, biofilm formation, and regulation of metabolism within the organism. This study highlights the adaptability of S. aureus in the face of antimicrobial treatment.
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影响因子：
3.6
作者：
Dubrac, Sarah;Bisicchia, Paola;Msadek, Tarek
通讯作者：
Msadek, Tarek
影响因子：
6.4
作者：
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影响因子：
3.2
作者：
Dubrac, S;Msadek, T
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Msadek, T
影响因子：
2.1
作者：
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影响因子：
2.6
作者：
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通讯作者：
Schneewind, O