Sulfonamide resistance in Neisseria meningitidis strains liberating various amounts of free endotoxin.

The relationship between sulfonamide susceptibility and the ability to liberate endotoxin was studied in 50 strains of Neisseria meningitidis. The endotoxin activity was investigated by the Limulus lysate test in growing cultures of 25 sulfonamide-resistant and 25 sensitive strains. The sulfonamide-resistant strains tended to have a higher endotoxin activity in cultures grown for 6 h than sensitive ones, and had also a higher amount of free, filtrable endotoxin.