NO INCREASE IN ENDOTOXIN RELEASE DURING ANTIBIOTIC KILLING OF MENINGOCOCCI

Endotoxin is liberated following antibiotic killing of Gram-negative r ods, and antibiotics may differ in this respect. Although the amount o f filterable endotoxin has also been reported to increase following an tibiotic killing of meningococci, it is unknown how this influences th e host response. We investigated the influence of three antibiotics on levels of free endotoxin in culture medium and cytokine production in whole blood ex vivo during killing of four strains of meningococci. B acterial killing was significantly more efficient with penicillin or c eftriaxone than with chloramphenicol, and free endotoxin levels were l ower after exposure to antibiotics as compared with no treatment (ANOV A, P < 0.001). Endotoxin levels were lowest after exposure to chloramp henicol. In three of the four strains exposure to antibiotics resulted in considerably lower cytokine levels (ANOVA, P < 0.001), and TNF-a l evels were significantly lower after exposure to penicillin or ceftria xone than after chloramphenicol treatment. Only in the strain that ind uced the lowest levels of TNF-a were cytokine levels comparable for un treated and treated samples. We conclude that fear of excessive endoto xin release or cytokine production caused by effective antibiotics is not justified in the treatment of meningococcal infections.