Livestock origin for a human pandemic clone of community-associated methicillin-resistant Staphylococcus aureus.
Livestock origin for a human pandemic clone of community-associated methicillin-resistant Staphylococcus aureus.
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DOI：
10.1128/mbio.00356-13
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发表时间：
2013-08-13
期刊：
影响因子：
6.4
通讯作者：
Fitzgerald JR
中科院分区：
文献类型：
--
作者：
Spoor LE;McAdam PR;Weinert LA;Rambaut A;Hasman H;Aarestrup FM;Kearns AM;Larsen AR;Skov RL;Fitzgerald JR
牲畜作为细菌病原体来源的重要性，以及在人群中流行病传播的可能性尚不清楚。近年来，健康人群社区相关耐甲氧西林金黄色葡萄球菌（CA-MRSA）感染在全球范围内有所增加，但对CA-MRSA克隆的不同进化起源及其最近扩张的基础缺乏了解。在这里，使用高分辨率的系统发育方法，我们报告了两个紧急克隆的人类流行性CA-MRSA的发现，这是由于独立的牲畜到人类宿主跳跃的主要牛金黄色葡萄球菌复合体，CC 97。值得注意的是，其中一个新的克隆体是从四大洲的人类感染中分离出来的，这表明它自40多年前发生宿主跳跃以来在全球传播。两种人类金黄色葡萄球菌克隆的出现与编码抗菌素耐药性和人类特异性免疫逃避介质的移动的遗传元件的独立获得相一致，这与这些遗传事件在人群中存活和传播能力中的重要作用一致。总之，我们提供的证据表明，牲畜代表了新的人类致病性金黄色葡萄球菌克隆的出现与大流行传播的能力水库。这些发现具有重大的公共卫生意义，突出了监测对早期识别紧急克隆和改善人畜界面传播控制措施的重要性。动物是影响人类的新病原体的主要来源。然而，最初在动物中发现的致病菌转换宿主并在人群中广泛存在的可能性尚不清楚。在这里，我们报告了耐甲氧西林金黄色葡萄球菌（MRSA）的紧急克隆的发现，这些克隆起源于牲畜并转移到人类，随后在全球人群中进行了宿主适应性进化和流行病传播。我们的研究结果表明，牲畜可以作为新的人类细菌克隆出现的水库，具有大流行传播的潜力，突出了农业环境中的监测和生物安全措施在预防新的人类病原体出现方面的潜在作用。
The importance of livestock as a source of bacterial pathogens with the potential for epidemic spread in human populations is unclear. In recent years, there has been a global increase in community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections of healthy humans, but an understanding of the different evolutionary origins of CA-MRSA clones and the basis for their recent expansion is lacking. Here, using a high-resolution phylogenetic approach, we report the discovery of two emergent clones of human epidemic CA-MRSA which resulted from independent livestock-to-human host jumps by the major bovine S. aureus complex, CC97. Of note, one of the new clones was isolated from human infections on four continents, demonstrating its global dissemination since the host jump occurred over 40 years ago. The emergence of both human S. aureus clones coincided with the independent acquisition of mobile genetic elements encoding antimicrobial resistance and human-specific mediators of immune evasion, consistent with an important role for these genetic events in the capacity to survive and transmit among human populations. In conclusion, we provide evidence that livestock represent a reservoir for the emergence of new human-pathogenic S. aureus clones with the capacity for pandemic spread. These findings have major public health implications highlighting the importance of surveillance for early identification of emergent clones and improved transmission control measures at the human-livestock interface. Animals are the major source of new pathogens affecting humans. However, the potential for pathogenic bacteria that originally were found in animals to switch hosts and become widely established in human populations is not clear. Here, we report the discovery of emergent clones of methicillin-resistant Staphylococcus aureus (MRSA) that originated in livestock and switched to humans, followed by host-adaptive evolution and epidemic spread in global human populations. Our findings demonstrate that livestock can act as a reservoir for the emergence of new human bacterial clones with potential for pandemic spread, highlighting the potential role of surveillance and biosecurity measures in the agricultural setting for preventing the emergence of new human pathogens.