Detection of macrolide resistance mechanisms in Streptococcus pneumoniae and Streptococcus pyogenes using a multiplex rapid cycle PCR with microwell-format probe hybridization.

In this study, a multiplex rapid cycle PCR with microwell-format probe hybridization method was developed to perform high-volume screening for macrolide resistance determinants in isolates of Streptococcus pneumoniae and Streptococcus pyogenes. The method was then utilized to determine the distribution of macrolide resistance mechanisms in recent isolates of S. pneumoniae and S. pyogenes from Great Britain and Ireland. For 83 strains of macrolide resistant S. pneumoniae tested, 51 (61.4%) were positive for mef(A), 29 (34.9%) erm(B), two (2.4%) double mechanisms mef(A) + erm(B), and one (1.2%) negative for all mechanisms tested. For 56 strains of macrolide-resistant S. pyogenes tested, 33 (58.9%) were positive for erm(A) subclass erm(TR), 18 (32.1%) mef(A) and five (8.9%) erm(B).