The neisseriae are a group of Gram-negative diplococci 0.6-1.5 µm in diameter (see Fig. 1A). Two species of Neisseria, N. gonorrhoeae and N. meningitidis, are considered as true human pathogens. Both ...The neisseriae are a group of Gram-negative diplococci 0.6-1.5 µm in diameter (see Fig. 1A). Two species of Neisseria, N. gonorrhoeae and N. meningitidis, are considered as true human pathogens. Both of these organisms possess pili and adhesins for adherence to host cells, produce endotoxins, and resist destruction within phagocytes. N. meningitidis also produces a capsule to resist phagocytic engulfment.
