Increased adherence to vaginal epithelial cells and phagocytic killing of gonococci and urogenital meningococci associated with heat modifiable proteins.

Urogenital Neisseria meningitidis were characterized with regard to serogroup, colony morphology, the presence of heat modifiable proteins (HMP), attachment to human vaginal and buccal epithelial cells, and phagocytic killing by polymorphonuclear leukocytes. The findings were compared with those on gonococci, and with those on meningococci isolated from blood or cerebrospinal fluid, with regard to colony morphology, HMP and piliation. The opacity colony morphology characteristic could be used to predict the presence of HMP in gonococci but not in meningococci, and sodium dodecyl sulphate polyacrylamide gel electrophoresis had to be used to demonstrate this surface protein. The urogenital meningococci, serogroup Y, attached significantly more efficinetly to vaginal epithelial cells in the presence of HMP and behaved in this respect like those of gonococci. Gonococci and meningococci containing HMP were more sensitive to phagocytic killing than those without HMP. Meningococci from opaque and transparent colonies and isolated from patients with meningococcal disease had no demonstrable HMP. They showed low adherence to vaginal and buccal epithelial cells, with no difference between organisms from opaque or transparent colonies.