Culture-Negative Endocarditis and the Use of Molecular Diagnostics

Abstract

The management of infective endocarditis (IE) is very challenging in patients with blood cultures negative for a microorganism. Unfortunately, this situation is not uncommon, occurring in up to 30% of cases of IE. Precise microbiological diagnosis, however, is critical to optimize the antibiotic regimen, and thus, nonYculture-based molecular techniques are playing a growing role in the care of these patients. We present a patient with culture-negative IE due to Haemophilus parainfluenzae, with the pathogen identified only via molecular techniques.(Infect Dis Clin Pract 2010;18: 120Y123)

Molecular analysis of sarcoidosis lymph nodes for microorganisms: a case–control study with clinical correlates

“…The DNA extraction from paraffin-embedded blocks was performed after paraffin was removed by incubation in xylene using the Roche HighPure PCR template purification kit (Roche Diagnostics GmbH, Mannheim, Germany). 8 Several negative patient samples (unrelated to the present study) were included in each batch to rule out any contamination. Inhibition was ruled out by checking the ability of exogenously added target DNA to be amplified in the same PCR mix that contained DNA extracted from clinical specimen.…”

“…PCR analysis for 16S ribosomal DNA, heat shock protein 65 (hsp65), RNA polymerase subunit (rpoB) The 16S gene fragment was amplified as previously described. 8 The hsp65 gene was amplified using TB11 and TB12 primers, and the RNA polymerase subunit gene (rpoB) was amplified using MF and MR primers. 9 The amplified products were then sequenced using the Big Dye Sequencing kit (Applied Biosystems, Foster City, California, USA) as per the vendor's recommended protocol.…”