[Effect of subinhibitory concentrations of antibiotics on catalase activity of plague microbes].

It was shown that the presence of subinhibitory concentrations of ampicillin, cefotaxime or gentamicin in the cultivation medium had a marked inhibitory effect on the catalase activity of plague microbe. The effect depended on the characteristic features of plague microbe strains and the incubation temperature. When the cells of a virulent strain of the plague microbe Y. pestis 1300 were cultivated at a temperature of 37 degrees C on a medium containing the subinhibitory concentrations of ampicillin or cefotaxime, the pathogen virulence for albino mice significantly decreased.