An electron-microscope study of naturally occurring and cultured cells of Neisseria Gonorrhoeae.

Electron-microscope studies are reported in which gonococci grown in cultures are compared with those present in urethral exudates. Whereas naturally occurring cells presented a smooth appearance with parallel cell layers, cultured cells were rough and their surface layers appeared to be disorganised. Three different types of pili were observed in cultures; the most common type seemed to be a product of unfavourable growth conditions. The number of piliate cells in pus was variable but always much lower than the number of non-piliate cells found. A study of free endotoxin present in cultures was made and its fine structure is described. Further observations suggest that although the majority of gonococci are killed after phagocytosis, others survive and multiply--giving rise to clusters of gonococci within remnants of phagocytes. It is suggested that these coated clusters are infectious units.