POSSIBLE LETHAL ENHANCEMENT OF TOXINS FROM PUTATIVE PERIODONTOPATHOGENS BY NICOTINE - IMPLICATIONS FOR PERIODONTAL-DISEASE

Aim-To test the hypothesis that lethal synergy in the chick embryo mod el may occur between nicotine and bacterial products (cell-free extrac ellular toxins and cell lysates) of five putative periodontopathogens. Methods-The lethality of cell-free extracellular toxins and cell lysa tes of five periodontal species was assessed with or without nicotine in the chick embryo assay system. Ten putative periodontopathogens (fi ve species) were studied: Prevotella intermedia (n = 5), Porphyromonas gingivalis (n = 1), Porphyromonas asaccharolytica (n = 1), Fusobacter ium nucleatum (n = 2), and Fusobacterium necrophorum (n = 1). Results- Simultaneous testing of cell-free extracellular toxins from isolates W 50, PS2, PS3, PS4, and PS5 and nicotine resulted in a percentage kill significantly greater than expected (Fisher's Exact test). Simultaneou s testing of cell lysates from isolates W50, PS2, and PS5 and nicotine resulted in a percentage kill significantly greater than expected (Fi sher's Exact test). Conclusions-Lethal synergy in the chick embryo mod el may occur between nicotine and toxins from putative periodontopatho gens (both cell-free extracellular toxins and cell lysates). This may be an important mechanism by which smoking increases the severity of p eriodontal disease.