Comparative activity of LY146032 against anaerobic cocci

Fifty strains of anaerobic gram-positive cocci were tested in vitro against benzylpenicillin, teicoplanin, vancomycin and LY146032. The organisms displayed a wide range of susceptibility to penicillin and the minimum inhibitory concentration for 11 of the strains was greater than or equal to 1 mg penicillin/L. The activity of teicoplanin exceeded that of vancomycin by a factor of two. The activity of LY 146032 varied in different culture media and was dramatically potentiated by the addition of a physiological concentration of calcium. Peptococci were, in general, more susceptible than peptostreptococci to penicillin and to LY146032 in the absence of added calcium.