Staphylococcus aureus PhoU Homologs Regulate Persister Formation and Virulence
Staphylococcus aureus PhoU Homologs Regulate Persister Formation and Virulence
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金黄色葡萄球菌 PhoU 同源物调节持续形成和毒力
DOI：
10.3389/fmicb.2020.00865
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发表时间：
2020-05-26
影响因子：
5.2
通讯作者：
Qu, Di
中科院分区：
文献类型：
--
作者：
Shang, Yongpeng;Wang, Xiaofei;Qu, Di
在许多细菌物种中，Phou同系物是调节持续体形成和磷酸盐代谢的决定性因素之一；然而，Phou同系物的功能表现出物种特有的特征。金黄色葡萄球菌的发病机制与金黄色葡萄球菌的持续形成和毒力因子密切相关。目前，金黄色葡萄球菌中两个Phou同系物PhoU1和PhoU2的功能尚不清楚。在本研究中，在菌株USA500 2395中产生了PhoU1和PhoU2的单缺失和双缺失突变体。与亲本菌株相比，ΔPhoU1或ΔPhoU2突变体的持续力和毒力发生了变化，对万古霉素和左氧氟沙星的持续者减少了至少1,000倍，在A549细胞中存活24 h的胞内细菌数量减少到82或85%。α-溶血素在Δ-PhoU2突变体中的表达和活性均增强。转录组分析表明，573或285个基因在ΔPhoU1或ΔPhoU2突变体中与野生型相比差异表达至少2倍。参与碳代谢和丙酮酸代谢的基因上调，毒力基因和毒力调节基因下调，包括VII型分泌系统、丝氨酸蛋白酶、白血球蛋白、全局调节因子(SARA、ROT)和双组分信号转导系统(SAES)。相应地，PhoU1或PhoU2的缺失导致细胞内丙酮酸和ATP水平的增加。PhoU2的缺失，而不是PhoU1的缺失，导致无机磷运输基因的上调和细胞内无机多聚磷水平的增加。综上所述，金黄色葡萄球菌中的PhoU1和PhoU2都通过下调多种毒力因子(VII型分泌系统、丝氨酸蛋白酶和亮氨酸蛋白酶)和高活性碳代谢伴随细胞内ATP的增加来调节毒力。在金黄色葡萄球菌中的结果与我们之前在葡萄球菌表皮中发现的结果不同，在表皮葡萄球菌中，只有PhoU2调节生物膜和持续体的形成。两种葡萄球菌Phou同源物的功能差异值得进一步研究。
PhoU homologs are one of the determinant factors in the regulation of persister formation and phosphate metabolism in many bacterial species; however, the functions of PhoU homologs exhibit species-specific characteristics. The pathogenesis of Staphylococcus aureus is closely correlated with persister formation and virulence factors. The functions of two PhoU homologs, PhoU1 and PhoU2, in S. aureus are unclear yet. In this study, single- and double-deletion mutants of phoU1 and phoU2 were generated in strain USA500 2395. The ΔphoU1 or ΔphoU2 mutants displayed a change in persister formation and virulence compared to the parent strain; the persisters to vancomycin and levofloxacin were decreased at least 1,000-fold, and the number of intracellular bacteria surviving in the A549 cells for 24 h decreased to 82 or 85%. The α-hemolysin expression and activity were increased in the ΔphoU2 mutants. Transcriptome analysis revealed that 573 or 285 genes were differentially expressed by at least 2.0-fold in the ΔphoU1 or ΔphoU2 mutant vs. the wild type. Genes involved in carbon and pyruvate metabolism were up-regulated, and virulence genes and virulence regulatory genes were down-regulated, including type VII secretion system, serine protease, leukocidin, global regulator (sarA, rot), and the two-component signal transduction system (saeS). Correspondingly, the deletion of the phoU1 or phoU2 resulted in increased levels of intracellular pyruvate and ATP. Deletion of the phoU2, but not the phoU1, resulted in the up-regulation of inorganic phosphate transport genes and increased levels of intracellular inorganic polyphosphate. In conclusion, both PhoU1 and PhoU2 in S. aureus regulate virulence by the down-regulation of multiple virulence factors (type VII secretion system, serine protease, and leucocidin) and the persister generation by hyperactive carbon metabolism accompanied by increasing intracellular ATP. The results in S. aureus are different from what we have previously found in Staphylococcus epidermis, where only PhoU2 regulates biofilm and persister formation. The different functions of PhoU homologs between the two species of Staphylococcus warrant further investigation.