[Permeability of an actinomycoma for ristomycin (experimental studies)]

In vitro studies showed that ristomycin was the most active against actinomycetes causing actinomycosis as compared to benzylpenicillin, ampicillin, methicillin and lincomycin. The growth of the test microbes was inhibited by ristomycin in concentrations of 61--122 mg/ml. Since ristomycin was the most active against actinomycetes, its levels in the blood, parenchymatous organs, capsule and pus of actinomycomas of 5 rabbits infected wtih actino nycosis in the submaxillary area were determined. In the control healthy rabbit, the ristomycin levels were determined in the blood and organs. Ristomycin was administered intravenously in a single dose of 7000 mg/kg. Its concentrations in the animals were determined in 2.5 hours. The results of the experiments showed that ristomycin penetrated in therapeutic concentrations into the connective tissue capsule of actinomycoma. As for the other antibiotics tested earlier, they failed to penetrate this barrier. In 3 infected rabbits, ristomycin penetrated even the pus contained in actinomycoma. Ristomycin provides therapeutic concentrations in the disease focus and may produce a satisfactory therapeutic effect in treatment of actinomycosis.