Macrolide Resistance in Peptostreptococcus spp. Mediated by ermTR: Possible Source of Macrolide-Lincosamide-Streptogramin B Resistance in Streptococcus pyogenes

Eighty percent (21 of 26) of macrolide-resistant Peptostreptococcus strains studied harbored the ermTR gene. This methyltransferase gene is also the most frequently found gene among macrolide-lincosamide-streptogramin B-resistant Streptococcus pyogenes strains. Transfer of the ermTR gene from Peptostreptococcus magnus to macrolide-susceptible S. pyogenes strains indicates that this resistance determinant may circulate among gram-positive aerobic and anaerobic species of the oropharyngeal bacterial flora.