Investigation of Oxidative Stress Defenses of Neisseria gonorrhoeae by Using a Human Polymorphonuclear Leukocyte Survival Assay

Neisseria gonorrhoeae has well-characterized oxidative stress defense systems that protect against oxidative killing in in vitro assays. In contrast, mutant strains of N. gonorrhoeae lacking oxidative stress defenses are identical to the wild type when tested in an ex vivo survival assay using human polymorphonuclear leukocytes. Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection gonorrhea, is a host-adapted pathogen that poses serious health implications. Gonococcal infection is typically characterized by a symptomatic inflammatory re-sponse of the urogenital tract, which involves accumulation of activated polymorphonuclear leukocytes (PMNs) (4). The PMN-mediated inflammatory response involves migration of PMNs towards sites of infection, phagocytosis of microorgan-isms, and elimination of these organisms by oxygen-dependent and oxygen-independent mechanisms (reviewed in references 11 and 23). Stimulation of PMNs results in a rapid increase in oxyge