Identification of Streptococcus pneumoniae lytA, plyA and psaA genes in pleural fluid by multiplex real-time PCR

Abstract Introduction The aim was to evaluate the utility of a multiplex real-time PCR to detect Streptococcus pneumoniae lytA , plyA and psaA genes in pleural fluid (PF). Methods A collection of 81 PF samples was used. Sixty were considered positive for S. pneumoniae according to previous results (54 by an in-house lytA gene PCR and eight by universal rRNA PCR). Results The sensitivity for detection of the lytA , plyA and psaA genes by multiplex PCR was 100% (60/60), 98.3% (59/60) and 91.7% (55/60), respectively. The detection of all three genes was negative in 21 samples formerly confirmed as negative for S. pneumoniae (100% specificity) by the other procedures (9 by in-house lytA PCR and 12 by rRNA PCR). Conclusions The use of this multiplex PCR may be a useful option to identify S. pneumoniae directly in PF samples.