The CpxAR Two-Component System Contributes to Growth, Stress Resistance, and Virulence of Actinobacillus pleuropneumoniae by Upregulating wecA Transcription
The CpxAR Two-Component System Contributes to Growth, Stress Resistance, and Virulence of Actinobacillus pleuropneumoniae by Upregulating wecA Transcription
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DOI：
10.3389/fmicb.2020.01026
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发表时间：
2020-05-21
影响因子：
5.2
通讯作者：
Bei, Weicheng
中科院分区：
文献类型：
--
作者：
Yan, Kang;Liu, Ting;Bei, Weicheng
胸膜肺炎放线杆菌是猪传染性胸膜肺炎的病原菌。以.在胸膜肺炎中，CpxAR双组分系统对于适应性和生长至关重要。O抗原从外膜突出到细胞外部，外膜作为屏障，帮助细菌在恶劣的环境中生存。WecA是一种十一异戊二烯磷酸GlcNAc-1-磷酸转移酶，参与O-抗原重复单元的生物合成。在这项研究中，我们研究了CpxAR在A.胸膜肺炎我们的研究结果表明，CpxR正调控wecA的表达，直接结合到推定的启动子区的wecA。野生型，三角洲cpxAR，三角洲wecA，和补充菌株进行了研究，血清，氧化和渗透胁迫。Delta cpxAR和Delta wecA菌株比野生型更容易受到这些应力的影响，但互补菌株表现出与野生型相似的表型。感染Delta cpxAR和Delta wecA菌株的小鼠比感染野生型或补充菌株的小鼠表现出更低的死亡率和肺中的细菌负荷。本研究揭示了CpxAR双组分系统对A.胸膜肺炎的生长，应激抗性和毒力，通过上调wecA的表达。我们的研究结果为A.胸膜肺炎
Actinobacillus pleuropneumoniae is the pathogen of porcine contagious pleuropneumonia. In A. pleuropneumoniae, the CpxAR two-component system is essential for fitness and growth. The O-antigen protrudes from the outer membrane to the exterior of the cell, and the outer membrane serves as a barrier that helps the bacteria to survive in harsh environments. WecA, a undecaprenyl phosphate GlcNAc-1-phosphate transferase, is involved in O-antigen repeating unit biosynthesis. In this study, we investigated the role of CpxAR in the expression of wecA in A. pleuropneumoniae. Our results revealed that CpxR positively regulates wecA expression by directly binding to the putative promoter region of wecA. Wild-type, Delta cpxAR, Delta wecA, and complemented strains were investigated under serum, oxidative, and osmotic stresses. The Delta cpxAR and Delta wecA strains were more susceptible to these stresses than the wild-type, but the complemented strains showed phenotypes similar to those of the wild-type. Mice infected with the Delta cpxAR and Delta wecA strains exhibited lower mortality and bacterial loads in the lung than those infected with the wild-type or complemented strains. This study reveals that the CpxAR two-component system contributes to A. pleuropneumoniae growth, stress resistance, and virulence, by upregulating expression of wecA. Our findings provide new insight into the pathogenesis of A. pleuropneumoniae.