Quadriplex real-time polymerase chain reaction (lytA, mef, erm, pbp2bwt) for pneumococcal detection and assessment of antibiotic susceptibility

A quadriplex real-time polymerase chain reaction assay was developed for detecting pneumococci, penicillin susceptibility, and macrolide/lincosamide resistance. The assay was sensitive for all 4 targets (<10 copies) and correlated with antimicrobial susceptibilities in 172/180 isolates and 28/29 culture-positive clinical specimens. For 29 lytA-positive culture-negative specimens, the assay allowed interpretation of antimicrobial susceptibility.