Pseudomonas aeruginosa Host Immune Evasion

The opportunistic pathogen Pseudomonas aeruginosa is a common cause of pneumonia in immunocompromised and mechanically ventilated patients. By virtue of its large genome and genetic flexibility, P. aeruginosa is able to adapt to its environment regulating the expression of a large repertoire of virulence factors.It is capable of forming biofilms that favor persistence and evasion of phagocytic clearance. Within a biofilm the bacteria communicate via soluble quorum sensors regulating production of elastases and proteases. P. aeruginosa is able to modify expression of pathogen associated molecular patterns such that recognition by hosts immune receptors is minimized. The bacteria are also able to subvert the innate immune system through direct interaction with host cells and host immune cytokines. These strategies of immune evasion and the genetic pathways that regulate them have contributed to the unusual success of P. aeruginosa as on opportunistic pathogen.