title: Killing of Neisseria gonorrhoeae by human polymorphonuclear neutrophil granule extracts.
abstract: Neisseria gonorrhoeae was grown in vitro (on agar and in broth) and in vivo (in 10-day chicken embryos) and tested for its sensitivity to the bactericidal action of human neutrophil granule extracts. Under all conditions studied, type 1 and type 4 N. gonorrhoeae were killed equally well by dialyzed extracts of neutrophil granules (containing both azurophil and specific granule contents) and by the myeloperoxidase-Cl- - H2O2 bactericidal system. However, sensitivity to the bactericidal activity of granule extracts depended upon growth conditions and growth phase. Log-phase, egg-grown gonococci were the most sensitive; they were killed 100% by 250 to 300 micrograms of granule extract (60 min, 37 degrees C) per ml. N. gonorrhoeae grown on agar for 20 h (to stationary phase) were the least sensitive, being killed only 80 to 90% with 500 micrograms of granule extract per ml. Thus, susceptibility to granule extract of gonococci grown under the four conditions studied in this report decreased in the order: log phase, egg grown; log phase, broth grown; stationary phase, egg grown; and stationary phase, agar grown. Killing was time and temperature dependent; little killing occurred when incubations were done at 10 degrees C. Boiled granule extract had only minimal effects on N. gonorrhoeae viability. Addition of catalase (500 U/ml) to the granule extract bactericidal system did not protect; however, the same concentration of catalase completely inhibited the bactericidal activity of the myeloperoxidase-Cl- - H2O2 system.
mesh_terms: D001770:Blood Bactericidal Activity; D002374:Catalase / Q000378:metabolism; D002474:Cell-Free System; D003594:Cytoplasmic Granules / Q000276:immunology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D009344:Neisseria gonorrhoeae / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology*; D009195:Peroxidase / Q000378:metabolism; D013696:Temperature; D013997:Time Factors
chemical_list: D006861:Hydrogen Peroxide; D002374:Catalase; D009195:Peroxidase