Community-associated MRSA: what makes them special?
Community-associated MRSA: what makes them special?
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DOI：
10.1016/j.ijmm.2013.02.007
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发表时间：
2013-08
期刊：
影响因子：
--
通讯作者：
Otto M
中科院分区：
文献类型：
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作者：
Otto M
虽然耐甲氧西林金黄色葡萄球菌（MRSA）的感染传统上仅限于医院环境，但在过去二十年中出现了新型MRSA菌株，这些菌株能够感染医院环境以外的其他健康人群。这些社区相关的（CA-）MRSA菌株结合了联合收割机甲氧西林耐药性和增强的毒力和适应性。有趣的是，CA-MRSA菌株出现在全球范围内，并来自不同的背景，这表明在收敛进化中多次实现了保持足够水平的甲氧西林耐药性和以低适应性成本获得增强的毒力之间的"权衡"。然而，这一进程往往包括类似的变化。首先，所有CA-MRSA菌株通常都携带一种新型的甲氧西林耐药基因座，这种耐药基因座似乎会减少健身负担。此外，获得特定的毒素基因，最值得注意的是编码Panton-Valentine杀白细胞素（PVL）的基因，以及基因组编码的毒素（如α-毒素和酚可溶性调节蛋白（PSM））的基因表达的适应，进一步促进了CA-MRSA的进化。最后，USA300 CA-MRSA克隆的特殊流行病学成功可能特别是由于另一种基因获得，即speG基因的获得，其位于精氨酸分解代谢移动的元件（ACME）上并参与解毒有害的宿主衍生的多胺。
While infections with methicillin-resistant Staphylococcus aureus (MRSA) were traditionally restricted to the hospital setting, novel MRSA strains emerged over the last two decades that have the capacity to infect otherwise healthy people outside of the hospital setting. These communityassociated (CA-) MRSA strains combine methicillin resistance with enhanced virulence and fitness. Interestingly, CA-MRSA strains emerged globally and from different backgrounds, indicating that the “trade-off” between maintaining sufficient levels of methicillin resistance and obtaining enhanced virulence at a low fitness cost was achieved on several occasions in convergent evolution. However, frequently this process comprised similar changes. First and foremost, all CA-MRSA strains typically carry a novel type of methicillin resistance locus that appears to cause less of a fitness burden. Additionally, acquisition of specific toxin genes, most notably that encoding Panton-Valentine leukocidin (PVL), and adaptation of gene expression of genome-encoded toxins, such as alpha-toxin and phenol-soluble modulins (PSMs), further contributed to the evolution of CA-MRSA. Finally, the exceptional epidemiological success of the USA300 CA-MRSA clone in particular may have been due to yet another gene acquisition, namely that of the speG gene, which is located on the arginine catabolic mobile element (ACME) and involved in detoxifying harmful host-derived polyamines.