Effect of kanamycin on the reproduction of orthomyxoviruses.

Kanamycin sulphate at a concentration of 8 mmol/l had no effect on the protein synthesis in uninfected chick embryo cell (CEC) cultures, but caused a 2-fold decrease of virus-specific protein synthesis in CEC infected with fowl plague virus (FPV). Kanamycin at a concentration of 2 mmol/l decreased the yield of infectious FPV in one growth cycle experiments on CEC culture by 1.5 log10 units and when added into the agar overlay it decreased the plaque number by nearly 1 log10 unit. Inoculation of 10 mg of kanamycin into a chick embryo decreased the yield of virus by 1.0 log10. Administration of kanamycin to mice (5-10 mg for three days post infection) reduced mortality of the animals 2--3-fold. Antibiotics of the streptomycin group presumably may penetrate into orthomyxovirus-infected cells due to virus-induced impairment of leakiness of the cell membrane and inhibit both the virus protein synthesis and formation of infectious virions.