In vitro evaluation of teicoplanin and other antimicrobials against streptococci group D bacteria.

In vitro activities of teicoplanin were compared with those of ampicillin, imipenem, rifampicin, coumermycin and vancomycin against clinical isolates of Streptococcus faecalis (n = 100) and Streptococcus faecium (n = 30). Against Str. faecalis, ampicillin and imipenem had an MIC90 and MBC90 of 3.9 micrograms/ml. Coumermycin and rifampicin had poor bactericidal activity with MBC90 values of 31.2 and 62.5 micrograms/ml. Teicoplanin was extremely active with an MIC90 of 0.95 microgram/ml and an MBC90 of 1.86 micrograms/ml.