Table 1.

MICs of four antibiotics for 579 GCS isolates and 911 GGS isolates

Organisms (no. of isolates tested)Antimicrobial agentMIC (μg/ml)a% Resistantb
50%90%Range
GCS (579)Erythromycin0.0640.1250.064–643.6
Clindamycin0.0640.1250.032–21.0
Tetracycline0.5160.032–6413
Penicillin G0.0080.0320.008–0.50
GGS (911)Erythromycin0.0640.0640.064–>643.5
Clindamycin0.0640.1250.032–>640.3
Tetracycline2640.125–>6443
Penicillin G0.0160.0160.008–0.50
  • a 50% and 90%, MICs at which 50 and 90% of the isolates are inhibited.

  • b Breakpoints according to the National Committee for Clinical Laboratory Standards.