Antitumor activity in the culture supernatant fluid of Fusobacterium nucleatum strain KO-31.

Antitumor activity of Fusobacterium nucleatum strain KO-31, which had been isolated from the oral cavity, was investigated in Ehrlich carcinoma-bearing mice. The strain KO-31 was cultured in TF medium for 48 hr. One-half ml of the culture supernatant fluid was injected intraperitoneally during a 7-day period to mice with Ehrlich ascites carcinoma. The survival time of the treated mice prolonged remarkably. A significant reduction in size of the solid Ehrlich tumor was also achieved with the supernatant. Antitumor activity was not observed in the cell extract.