In vitro activities of the new ketolide HMR 3647 (telithromycin) in comparison with those of eight other antibiotics against viridans group Streptococci isolated from blood of neutropenic patients with cancer.

The in vitro activities of the ketolide telithromycin and eight other antibiotics were tested against 77 strains of viridans group streptococci isolated from blood samples of neutropenic patients. Thirty-one (40.3%) of the strains were resistant to penicillin G, and 27 (35.1%) were resistant to erythromycin A. Telithromycin (MIC range of < or =0.03 to 1 microg/ml) was the most active antimicrobial tested. These data suggest that telithromycin could be useful for treatment of viridans group streptococcal bacteremia in neutropenic patients with cancer.