de Andrade Flavia Costa Carvalho, Carvalho Mariana Fernandes, Figueiredo Agnes Marie Sá
Departamento de Microbiologia Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil.
Programa de Pós-Graduação em Patologia, Faculdade de Medicina, Universidade Federal Fluminense, Niterói 24033-900, Brazil.
Antibiotics (Basel). 2024 Nov 25;13(12):1131. doi: 10.3390/antibiotics13121131.
: The anti-restriction protein ArdA-H1, found in multiresistant (MRSA) strains from the ST239-SCCIII lineage, inhibits restriction-modification systems, fostering horizontal gene transfer (HGT) and supporting genetic adaptability and resistance. This study investigates the regulatory mechanisms controlling H1 expression in under various stress conditions, including acidic pH, iron limitation, and vancomycin exposure, and explores the roles of the Agr quorum sensing system. : The expression of H1 was analyzed in strains exposed to environmental stressors using real-time quantitative reverse transcription PCR. Comparisons were made between Agr-functional and Agr-deficient strains. In addition, Agr inhibition was achieved using a heterologous Agr autoinducing peptide. : The Agr system upregulated H1 expression in acidic and iron-limited conditions. However, vancomycin induced H1 activation specifically in the Agr-deficient strain GV69, indicating that an alternative regulatory pathway controls H1 expression in the absence of gr. The vancomycin response in GV69 suggests that diminished quorum sensing may offer a survival advantage by promoting persistence and HGT-related adaptability. : Overall, our findings provide new insights into the intricate relationships between quorum-sensing, stress responses, bacterial virulence, and genetic plasticity, enhancing our understanding of . adaptability in challenging environments.
在源自ST239 - SCCIII谱系的多重耐药（MRSA）菌株中发现的抗限制蛋白ArdA - H1，可抑制限制修饰系统，促进水平基因转移（HGT）并支持遗传适应性和耐药性。本研究调查了在各种应激条件下，包括酸性pH、铁限制和万古霉素暴露，控制金黄色葡萄球菌中H1表达的调控机制，并探讨了Agr群体感应系统的作用。：使用实时定量逆转录PCR分析暴露于环境应激源的金黄色葡萄球菌菌株中H1的表达。对具有功能性Agr和缺乏Agr的菌株进行了比较。此外，使用异源Agr自诱导肽实现了对Agr的抑制。：Agr系统在酸性和铁限制条件下上调H1表达。然而，万古霉素特异性地在缺乏Agr的菌株GV69中诱导H1激活，这表明在没有agr的情况下，一种替代调控途径控制H1表达。GV69中的万古霉素反应表明，减弱的群体感应可能通过促进持续性和与HGT相关的适应性提供生存优势。：总体而言，我们的研究结果为群体感应、应激反应、细菌毒力和遗传可塑性之间的复杂关系提供了新的见解，增强了我们对金黄色葡萄球菌在具有挑战性的环境中的适应性的理解。
