To cheat or not to cheat: cheatable and non-cheatable virulence factors in Pseudomonas aeruginosa

Important bacterial pathogens such as Pseudomonas aeruginosa produce several exoproducts such as siderophores, degradative enzymes, biosurfactants, and exopolysaccharides that are used extracellularly, benefiting all members of the population, hence being public goods. Since the production of public goods is a cooperative trait, it is in principle susceptible to cheating by individuals in the population who do not invest in their production, but use their benefits, hence increasing their fitness at the expense of the cooperators' fitness. Among the most studied virulence factors susceptible to cheating are siderophores and exoproteases, with several studies in vitro and some in animal infection models. In addition to these two well-known examples, cheating with other virulence factors such as exopolysaccharides, biosurfactants, eDNA production, secretion systems, and biofilm formation has also been studied. In this review, we discuss the evidence of the susceptibility of each of those virulence factors to cheating, as well as the mechanisms that counteract this behavior and the possible consequences for bacterial virulence. Pseudomonas aeruginosa synthesizes several virulence factors which are public goods; here we discuss the susceptibility of these factors for being exploited by defectors and the mechanisms that counteract their exploitation.

Automated summary

This article discusses the susceptibility of important bacterial pathogens such as Pseudomonas aeruginosa in producing public goods that are prone to being exploited by cheaters. It focuses on the cheating behaviors related to virulence factors like siderophores and exoproteases, and also explores the mechanisms that counteract these exploitations and their potential consequences on bacterial virulence.