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

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.