Significance Bacterial pathogens frequently use type 3 secretion systems (T3SS) to counteract host immune responses to infection. T3SS expression is associated with increased virulence of Pseudomonas aeruginosa in humans and in animal models, but T3SS-negative bacteria often are isolated from acutely and chronically infected patients. We tested whether T3SS-negative bacteria could “cheat” during mixed infections with T3SS-positive bacteria in a murine model of acute pneumonia. Bacterial cheating occurred in the inflamed lung but only when T3SS-positive bacteria secreted the phospholipase A 2 effector, Exotoxin U. Phenotypically T3SS-expressing and –non-expressing bacteria co-exist within P. aeruginosa populations, suggesting that bacterial cheating might allow T3SS-negative organisms to establish themselves within a host.
Journal article
Proceedings of the National Academy of Sciences
Proceedings of the National Academy of Sciences
27/05/2014
111
7801 - 7806