Evolutionary Processes Driving the Rise and Fall of Staphylococcus aureus ST239, a Dominant Hybrid Pathogen.
Evolutionary Processes Driving the Rise and Fall of Staphylococcus aureus ST239, a Dominant Hybrid Pathogen.
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DOI：
10.1128/mbio.02168-21
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发表时间：
2021-12-21
期刊：
影响因子：
6.4
通讯作者：
MacLean RC
中科院分区：
文献类型：
--
作者：
Gill JL;Hedge J;Wilson DJ;MacLean RC
选择在抗生素耐药性的传播中起着关键作用，但临床上重要的耐药菌株的进化驱动因素仍然知之甚少。在这里，我们使用基因组分析和竞争实验来研究金黄色葡萄球菌ST239，一种著名的MRSA菌株，被认为是由ST8和ST30之间的大规模重组形成的。基因组分析使我们能够完善ST239起源的杂交模型，并将ST239的起源追溯到1920到1945，这比1959年甲氧西林临床引入之前。虽然净化选择主导了ST239的进化，但参与抗生素耐药性和毒力的基因也发生了平行进化，这表明ST239已经进化成一种越来越致病的生活方式。至关重要的是，与ST8和ST30菌株相比，ST239菌株的竞争适合度较低，支持了这样一种观点，即适应成本导致了这种曾经占主导地位的病原体菌株的消亡。
Selection plays a key role in the spread of antibiotic resistance, but the evolutionary drivers of clinically important resistant strains remain poorly understood. Here, we use genomic analyses and competition experiments to study Staphylococcus aureus ST239, a prominent MRSA strain that is thought to have been formed by large-scale recombination between ST8 and ST30. Genomic analyses allowed us to refine the hybrid model for the origin of ST239 and to date the origin of ST239 to 1920 to 1945, which predates the clinical introduction of methicillin in 1959. Although purifying selection has dominated the evolution of ST239, parallel evolution has occurred in genes involved in antibiotic resistance and virulence, suggesting that ST239 has evolved toward an increasingly pathogenic lifestyle. Crucially, ST239 isolates have low competitive fitness relative to both ST8 and ST30 isolates, supporting the idea that fitness costs have driven the demise of this once-dominant pathogen strain.