Macrolide-Resistant Streptococcus pneumoniae in Canada during 1998–1999: Prevalence of mef (A) and erm (B) and Susceptibilities to Ketolides

Abstract

ABSTRACT In this study (1998–1999), we collected 215 macrolide-resistant Streptococcus pneumoniae isolates from an ongoing Canadian Respiratory Organism Surveillance Study involving 23 centers representing all regions of Canada. The prevalence of erythromycin-resistant S. pneumoniae was 8% (215 of 2,688). Of the 215 isolates, 48.8% (105 of 215) were PCR positive for mef (A) and 46.5% (100 of 215) were PCR positive for erm (B). The ketolides telithromycin and ABT-773 demonstrated excellent activity against both mef (A) (MIC for 90% of strains [MIC 90 ], 0.06 and 0.03 μg/ml, respectively) and erm (B) (MIC 90 , 0.06 and 0.03 μg/ml, respectively) strains of S. pneumoniae .