Macrolide- and telithromycin-resistant Streptococcus pyogenes, Belgium, 1999-2003.

We found a 13% macrolide resistance in 3,866 Streptococcus pyogenes isolated from tonsillopharyngitis patients; 59% macrolide-resistant isolates were distributed in 5 clones, suggesting the importance of both resistance gene transfer and clonal dissemination in the spread of these organisms. We also report one of the largest collections of telithromycin-resistant isolates.

Oropharyngeal carriage of macrolide-resistant viridans group streptococci: a prevalence study among healthy adults in Belgium.

Objectives: Viridans group streptococci (VGS) are gaining significance as reservoirs of resistance determinants for respiratory tract pathogens. Our aim was to investigate healthy adults for oropharyngeal carriage of VGS that are resistant to macrolides, as well as to other common antibiotics.

Methods: Macrolide-resistant VGS were isolated from throat samples of 154 healthy Belgian adults, and phenotyped and genotyped for erm(A), erm(B) and mef(A).