Zhang Xiaoyun, Zhai Yaxuan, Zhu Jie, Zhu Zhichen, Wen Yicheng, Gao Qizhao, Wang Liang, Lin Jiayao, Qian Yan, Chen Liang, Du Hong
Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
Department of Clinical Laboratory, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, Jiangsu, China.
Microbiol Spectr. 2025 Jun 3;13(6):e0307624. doi: 10.1128/spectrum.03076-24. Epub 2025 May 15.
causes both community-acquired and healthcare-associated infections, presenting a major therapeutic challenge to global public health. RstBA is a common two-component regulatory system that controls downstream gene expression in certain species. However, the role of RstBA in infection remains unknown. To determine its function, a wild-type strain (ATCC43816) and mutant and complementation strains were constructed. Phenotypic experiments and animal infection assays demonstrated that deletion of decreased virulence and biofilm formation. RNA sequencing analysis of ATCC43816 and mutant strains was performed to study the regulatory mechanisms, revealing differential expression of genes involved in arginine and proline metabolism, phenylalanine metabolism, and quorum sensing. In addition, the and the gene cluster, which regulates and encodes type 3 fimbriae, exhibited lower expression in the absence of , possibly related to decreased virulence and biofilm formation. Quantitative real-time reverse transcription PCR, promoter activity assays, and electrophoretic mobility shift assays were conducted to identify the transcriptional regulation of and by . Our findings show that regulates type 3 fimbriae expression by regulating indirectly and regulating directly by binding to its promoter. This study provides new insights into the functional importance of RstA in regulating biofilm formation and virulence in .IMPORTANCE is an opportunistic pathogen that has become a significant cause of community-acquired and nosocomial infections. The rise of hypervirulent and multi-drug-resistant poses a significant threat to public health. The two-component regulatory system is a typical signal-sensing and stress-response system widely distributed in bacteria, playing a critical regulatory role in bacterial infection. Through and experiments, we demonstrate that regulates the expression of type 3 fimbriae by regulating indirectly and directly, thereby playing an essential role in the virulence and biofilm formation of . Understanding the regulatory mechanism of RstA in provides a proof-of-concept for identifying new genetic targets for controlling infection, which may aid in the development of therapeutic drugs.
可引发社区获得性感染和医疗保健相关感染，给全球公共卫生带来重大治疗挑战。RstBA是一种常见的双组分调节系统，可控制某些物种下游基因的表达。然而，RstBA在感染中的作用尚不清楚。为确定其功能，构建了野生型菌株（ATCC43816）、突变株和互补株。表型实验和动物感染试验表明，缺失该基因会降低毒力和生物膜形成能力。对ATCC43816和突变株进行RNA测序分析以研究调控机制，结果显示参与精氨酸和脯氨酸代谢、苯丙氨酸代谢以及群体感应的基因存在差异表达。此外，调控和编码3型菌毛的基因簇在缺失该基因时表达较低，这可能与毒力和生物膜形成能力降低有关。进行了定量实时逆转录PCR、启动子活性测定和电泳迁移率变动分析，以确定该基因对上述两个基因的转录调控。我们的研究结果表明，该基因通过间接调控另一个基因来调节3型菌毛表达，并通过结合其启动子直接调控该基因。本研究为RstA在调节生物膜形成和毒力方面的功能重要性提供了新见解。重要性该菌是一种机会致病菌，已成为社区获得性感染和医院感染的重要原因。高毒力和多重耐药菌株的出现对公共卫生构成重大威胁。双组分调节系统是一种典型的信号感知和应激反应系统，广泛分布于细菌中，在细菌感染中起关键调节作用。通过实验，我们证明该基因通过间接调控一个基因和直接调控另一个基因来调节3型菌毛的表达，从而在该菌的毒力和生物膜形成中发挥重要作用。了解RstA在该菌中的调控机制为确定控制该菌感染的新基因靶点提供了概念验证，这可能有助于治疗药物的开发。
