Comparative transcriptomics and genomics from continuous axenic media growth identifies Coxiella burnetii intracellular survival strategies
Comparative transcriptomics and genomics from continuous axenic media growth identifies Coxiella burnetii intracellular survival strategies
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DOI：
10.1093/femspd/ftad009
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发表时间：
2023-01-17
影响因子：
3.3
通讯作者：
Shaw，Edward
中科院分区：
文献类型：
--
作者：
Yadav，Archana;Brewer，Melissa N.;Shaw，Edward
贝氏柯克斯体（Coxiellaburnetii，Cb）是一种专性胞内致病菌，是急性Q热和慢性疾病的病原体。为了鉴定对其正常细胞内生长生活方式至关重要的基因和蛋白质，我们应用了“反向进化”方法，其中将Cb的无毒Nine Mile II期菌株在化学成分确定的ACCM-D培养基中生长67代，并将来自各代的基因表达模式和基因组完整性与细胞内生长后的第一代进行比较。转录组学分析鉴定了4 B型分泌系统（T4 BSS）、一般分泌（Sec）途径的结构组分以及先前鉴定的118个编码效应蛋白的基因中的14个的显著下调。其他下调的致病性决定基因包括几种分子伴侣、LPS和肽聚糖生物合成。还观察到中枢代谢途径的普遍显著下调，这通过编码转运蛋白的基因的显著上调来平衡。这种模式反映了媒体的丰富性和减少合成代谢和ATP生成的需求。最后，基因组测序和比较基因组分析表明，尽管观察到的Cb基因表达的变化后，适应无菌培养基的突变水平极低，跨代。
Coxiella burnetii(Cb) is an obligate intracellular pathogen in nature and the causative agent of acute Q fever as well as chronic diseases. In an effort to identify genes and proteins crucial to their normal intracellular growth lifestyle, we applied a ‘reverse evolution’ approach where the avirulent Nine Mile Phase II strain of Cb was grown for 67 passages in chemically defined ACCM-D media and gene expression patterns and genome integrity from various passages was compared to passage number one following intracellular growth. Transcriptomic analysis identified a marked downregulation of the structural components of the type 4B secretion system (T4BSS), the general secretory (Sec) pathway, as well as 14 out of 118 previously identified genes encoding effector proteins. Additional downregulated pathogenicity determinants genes included several chaperones, LPS, and peptidoglycan biosynthesis. A general marked downregulation of central metabolic pathways was also observed, which was balanced by a marked upregulation of genes encoding transporters. This pattern reflected the richness of the media and diminishing anabolic, and ATP-generation needs. Finally, genomic sequencing and comparative genomic analysis demonstrated an extremely low level of mutation across passages, despite the observed Cb gene expression changes following acclimation to axenic media.