Improved detection of microbial DNA after bead-beating before DNA isolation.

Detection of microbial DNA in clinical samples by real-time PCR requires a universal extraction method with equally efficient lysis of cell walls of all possible microorganisms. We demonstrated that physical disruption by bead-beating with 0.1mm beads in combination with MagNA Pure DNA III extraction enhances microbial lysis of diverse Gram-positive microorganisms and may be used to optimize DNA extraction protocols in routine clinical diagnostics.

Streptococcus pneumoniae DNA load in blood as a marker of infection in patients with community-acquired pneumonia.

Direct detection of Streptococcus pneumoniae DNA in blood adds to culture results in the etiological diagnosis of patients with community-acquired pneumonia (CAP). Quantification of the amount of DNA, the bacterial DNA load (BDL), provides a measurement of DNAemia that may increase the understanding of the clinical relevance of S. pneumoniae DNA in blood.

Quantitative detection of Staphylococcus aureus and Enterococcus faecalis DNA in blood to diagnose bacteremia in patients in the intensive care unit.

Direct detection of bacterial DNA in blood offers a fast alternative to blood culture and is presumably unaffected by the prior use of antibiotics. We evaluated the performance of two real-time PCR assays for the quantitative detection of Staphylococcus aureus bacteremia and for Enterococcus faecalis bacteremia directly in blood samples, without prior cultivation. Whole-blood samples for PCR were obtained simultaneously with blood cultures from patients admitted to the intensive care unit of our hospital.