铜绿假单胞菌生物被膜组成及其受群体感应系统和c-di-GMP调控的研究进展

Regulation of Pseudomonas aeruginosa biofilms by quorum sensing systems and c-di-GMP

摘要:

作为人类条件性感染的前三大病原菌之一的铜绿假单胞菌，是一种革兰氏阴性细菌，对免疫功能低下和囊性纤维化患者可以造成严重和持续性感染。造成这种持续感染的原因主要是由于细菌接收外界信号后，在自身调控网络的协同作用下，会依附于固体表面，并产生胞外多糖、基质蛋白和胞外DNA等大分子物质形成高度结构化的膜状复合物将自身包裹形成生物被膜群体结构。生物被膜可以有效帮助细菌定殖、提高细菌对抗菌物质和宿主免疫反应的抵抗能力、促进群落细菌的细胞-细胞之间的信号交流等，是临床治疗中病原菌慢性感染和反复感染最重要的原因之一。本篇综述重点介绍了铜绿假单胞菌生物被膜的各组成成分及其在生物被膜形成中的重要功能，并进一步阐述了群体感应系统（las、rhl、pqs与iqs）和c-di-GMP对铜绿假单胞菌生物被膜形成的调控作用。通过本篇综述可以更清晰地了解细菌生物被膜形成和调控的过程，为开发新的治疗生物被膜感染策略提供帮助。

Abstract:

Pseudomonas aeruginosa, one of the three leading pathogens of human opportunistic infection, is a Gram-negative bacterium that can cause severe and persistent infections in patients with immunocompromised and cystic fibrosis. The reason for this persistent infection is mainly due to the synergy of bacteria with their own regulatory network after receiving external signals. These bacteria attach to solid surfaces and produce macromolecular substances such as extracellular polysaccharides, matrix proteins, and extracellular DNA. These macromolecules can form highly structured membranous complexes that wrap themselves to form biofilm morphotype and population structure. Biofilms can effectively facilitate bacterial colonization, resistance to antimicrobial substances and host immune responses, and cell-to-cell signal communication within a bacterial community. Thus, it is one of the most important causes of chronic infection and repeated infection of pathogens in clinical treatment. This review focuses on the recent processes in study of the P. aeruginosa biofilm components and their roles in biofilm formation, as well as the function of related regulatory systems, including the quorum sensing system (las, rhl, pqs and iqs) and the c-di-GMP system. Through this review, we provide a more systematic understanding the development of P. aeruginosa biofilm, which will reinforce the treatment of P. aeruginosa infection.