Editor: Mark Enright
Real-time PCR assays for the detection and quantification of Streptococcus pneumoniae
Article first published online: 18 JUN 2010
© 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 310, Issue 1, pages 48–53, September 2010
How to Cite
Park, H. K., Lee, H. J. and Kim, W. (2010), Real-time PCR assays for the detection and quantification of Streptococcus pneumoniae. FEMS Microbiology Letters, 310: 48–53. doi: 10.1111/j.1574-6968.2010.02044.x
- Issue published online: 4 AUG 2010
- Article first published online: 18 JUN 2010
- Received 14 February 2010; accepted 8 June 2010.Final version published online 14 July 2010.
Vol. 311, Issue 2, 200, Article first published online: 23 AUG 2010
Streptococcus pneumoniae is the main etiologic agent of pneumonia worldwide. Because the members of the viridans group streptococci share a high degree of DNA sequence homologies, phenotypic and genotypic discriminations of S. pneumoniae from the viridans group are difficult. A quantitative real-time PCR assay targeting the capsular polysaccharide biosynthesis gene (cpsA) was developed as a species-specific detection tool for S. pneumoniae. The specificity was evaluated using genomic DNAs extracted from 135 oral cocci strains. Twenty-seven S. pneumoniae strains tested positive, whereas 108 other strains including Streptococcus pseudopneumoniae, Streptococcus mitis, and Streptococcus oralis did not show a specific signal. The linear regression of standard curves indicated high correlations between the log numbers of S. pneumoniae cells and the CT values (R2=0.99). The minimal limit of detection was 32 fg of purified genomic DNA, equivalent to 14 genomes of S. pneumoniae. This new real-time PCR method may be very useful as a rapid and specific tool for detecting and quantifying S. pneumoniae.