Release of endotoxin from Neisseria meningitidis. A short survey with a preliminary report on virulence in mice.

Gram-negative bacteria release various amounts of cell wall fragments containing endotoxin into the surroundings. The authors demonstrated that liberation of endotoxin from Neisseria meningitidis during growth varied with strain and growth conditions and was dependent on whether the strains released large quantities of cell wall fragments into the medium or not. The ability to liberate endotoxin could be lost upon subcultivation and was associated with certain traits. The experiments indicated that short-lasting therapy with a penicillin dose big enough to give a rapid bactericidal effect increased the release of free, filtrable endotoxin from endotoxin liberating meningococci, but not from a non-liberating variant. This effect was not found when the meningococci were treated with chloramphenicol. The endotoxin liberating meningococcal strains were more virulent for mice than the non-liberating variants, indicating that the tendency to liberate cell wall fragments containing endotoxin may be a factor in the pathogenesis of meningococcal disease in mice.