[Experimental protection with tyrothrizin against herpes simplex virus infections in mice]

Using 12-day old baby mice, strain NMRI, the LD50 of a Herpes simplex virus type 1 was calculated. Intragastric inoculation of the mice was carried out applying a stomach tube. Lethality of the mice was reduced from 67% to 23% by pre-incubation of the virus suspension for 30 min at 37 degrees C in the presence of 0.2 mg tyrothricin/ml. The effect was statistically significant and could be produced only after direct contact between tyrothricin and virus. Under the same conditions there was no effect of lysozyme against virus infectivity.