Virulence strategies of the dominant USA300 lineage of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).
Virulence strategies of the dominant USA300 lineage of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).
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DOI：
10.1111/j.1574-695x.2012.00937.x
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发表时间：
2012-06
影响因子：
--
通讯作者：
Richardson AR
中科院分区：
文献类型：
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作者：
Thurlow LR;Joshi GS;Richardson AR
耐甲氧西林金黄色葡萄球菌(MRSA)对全球健康构成严重威胁。从历史上看，MRSA克隆严格与医院环境有关，大多数医院相关的MRSA(HA-MRSA)疾病都是由有限数量的毒力克隆引起的。最近，MRSA已经蔓延到社区，在其他健康的人中引起疾病，这些人与医疗环境没有明显的接触。这些社区相关(CA-MRSA)菌株在系统发育上不同于传统的HA-MRSA克隆，CA-MRSA菌株似乎表现出超强毒力和更有效的宿主-宿主传播。因此，属于USA300血统的CA-MRSA克隆已成为北美MRSA感染的主要来源。这一成功的USA300谱系的崛起代表着新出现的病原体进化的重要一步，人们已经付出了大量努力来了解这些克隆是如何进化的。在这里，我们回顾了许多旨在阐明USA300成功的来源的最新文献，并将这些发现大致归类为三大类：新获得的毒力基因、常见毒力决定因素的表达变化以及提高适应性的蛋白质序列变化。我们认为，这些进化事件本身并不能解释USA300的成功，而是它们的结合可能是CA-MRSA的兴起和传播的原因。
Methicillin-Resistant Staphylococcus aureus (MRSA) poses a serious threat to worldwide health. Historically, MRSA clones have strictly been associated with hospital settings and most hospital-associated MRSA (HA-MRSA) disease resulted from a limited number of virulent clones. Recently, MRSA has spread into the community causing disease in otherwise healthy people with no discernible contact with healthcare environments. These community-associated (CA-MRSA) are phylogenetically distinct from traditional HA-MRSA clones and CA-MRSA strains seem to exhibit hyper virulence and more efficient host:host transmission. Consequently, CA-MRSA clones belonging to the USA300 lineage have become dominant sources of MRSA infections in North America. The rise of this successful USA300 lineage represents an important step in the evolution of emerging pathogens and a great deal of effort has been exerted to understand how these clones evolved. Here we review much of the recent literature aimed at illuminating the source of USA300 success and broadly categorize these findings into three main categories: newly acquired virulence genes, altered expression of common virulence determinants and alterations in protein sequence that increase fitness. We argue that none of these evolutionary events alone account for the success of USA300, but rather their combination may be responsible for the rise and spread of CA-MRSA.