Competitor lysis and peptidoglycan scavenging by Pseudomonas aeruginosa during polymicrobial infection: role in biofilm maturation, persistence, and virulence

01/11/2020 to 31/10/2023

Pseudomonas aeruginosa is an ubiquitous Gram-negative bacterium and an opportunistic pathogen commonly associated with polymicrobial infections. The prevalence of P. aeruginosa in polymicrobial biofilms associated with chronic infectious diseases suggests that the bacterium has evolved effective strategies to contain competitors and to evade the human immune response during growth within biofilms, thereby enhancing host colonization, persistence, and virulence. However, the underlying processes are insufficiently understood. The peptidoglycan cell wall, essential for most bacteria, is an important target for P. aeruginosa in this rivalry. The bacterium lyses neighbouring cells during the maturation of biofilms, e.g. through injection of peptidoglycan hydrolases via type VI secretion systems. In this project, we will explore how cleavage and salvage of the peptidoglycan of competitor and possibly also sibling cells contributes to enhanced survival, persistence, and virulence of P. aeruginosa in polymicrobial biofilms. We aim to discover the pathways used by P. aeruginosa to feed on peptidoglycan degradation products and to establish regulatory networks crucial to form persistent biofilms during polymicrobial infections.