Emergence of a Streptococcus pneumoniae clinical isolate highly resistant to telithromycin and fluoroquinolones.

Streptococcus pneumoniae is a major pathogen causing community-acquired pneumonia and acute bronchitis. Macrolides, fluoroquinolones (FQs), and, recently, telithromycin (TEL) constitute primary therapeutic options, and rare cases of resistance have been reported. In this report, we describe the emergence of an S. pneumoniae clinical isolate with high-level TEL resistance (MIC, 256 microg/ml) and simultaneous resistance to FQs. Ongoing studies are oriented to elucidate the precise mechanism of resistance to TEL.