[Protective properties of doxycycline, rifampicin and sisomycin in experimental pulmonary tularemia of albino mice].

The protective effects of doxycycline, rifampicin and sisomicin were compared in a multifactor experiment with animal infection induced by finally dispersed aerosol of a virulent strain of the European variant of the tularemia causative agent and the optimal regimens for the antibiotic use were determined. By the values of the protective effect rifampicin and sisomicin were shown to provide a high percentage of the animal survival: more than 80 and up to 50-70 per cent of the animals survived when the aerosol infective doses were 100 and 10,000 LD50, respectively. A characteristic feature of doxycycline was its activity only in the infection induced by low doses of the biological agent. The optimal course of the antibiotic therapy in inhalation tularemia was 6 to 8 days. The interval of 1 to 3 days between the infection and the therapy start had no significant effect on the protective efficacies of the antibiotics.