Cell death of human polymorphonuclear neutrophils induced by a Pseudomonas aeruginosa cystic fibrosis isolate requires a functional type III secretion system.

With a coincubation model incorporating Pseudomonas aeruginosa and human polymorphonuclear neutrophils (PMNs), a cystic fibrosis (CF) P. aeruginosa isolate has been shown to resist the bactericidal action of PMNs and to induce their cellular death. An isogenic mutant of this CF isolate in which the type III secretion system was rendered nonfunctional was unable to induce cellular death of PMNs.