Use of an automated PCR assay, the GenomEra S. pneumoniae, for rapid detection of Streptococcus pneumoniae in blood cultures.
BACKGROUND
Streptococcus pneumoniae is recognized as a major cause of pneumonia, meningitis, and bacteremia. Since the mortality rate for pneumococcal bacteremia remains high, the reliable detection of the bacterium in blood samples is important. In this study, the performance of a new automated PCR assay, the GenomEra(™) S. pneumoniae, for direct detection of S. pneumoniae in blood cultures was investigated.


METHODS
In total, 200 samples were analyzed, including 90 previously identified culture collection isolates and 110 blood culture specimens. The species identification was confirmed with routine diagnostic methods including MALDI-TOF or 16S rDNA sequencing.


RESULTS
From culture collection, the GenomEra S. pneumoniae assay correctly identified all 37 S. pneumoniae isolates consisting of 18 different serotypes, while all 53 non-S. pneumoniae isolates yielded negative test results. Of 110 blood culture specimens, 46 grew S. pneumoniae and all were positive by the GenomEra assay direct from bottle. The detection sensitivity and specificity of the GenomEra assay for direct analysis of S. pneumoniae in signal positive blood culture bottles was 100%, respectively. With a straightforward sample preparation protocol of blood cultures the results were available within 55 min, thus being significantly quicker than by the routinely used identification methods (18-48 h). The two-step, time-resolved fluorometric measurement mode employed by the GenomEra CDX(™) instrument showed no interference from blood or charcoal.


CONCLUSION
The GenomEra S. pneumoniae assay is a tool that performs well for the rapid and reliable detection of S. pneumoniae in blood cultures.
['Hirvonen|Jari J|JJ|', 'Seiskari|Tapio|T|', 'Harju|Inka|I|', 'Rantakokko-Jalava|Kaisu|K|', 'Vuento|Risto|R|', 'Aittoniemi|Janne|J|']
D016470:Bacteremia D001769:Blood D006801:Humans D011008:Pneumococcal Infections D016133:Polymerase Chain Reaction D011933:Reagent Kits, Diagnostic D012680:Sensitivity and Specificity D013296:Streptococcus pneumoniae
PCR Streptococcus pneumoniae bacteremia diagnosis molecular assay