Antibiotic therapy following polymerase chain reaction diagnosis of infective endocarditis: a single centre...

Conventional culture methods often fail in the aetiological diagnosis of infective endocarditis (IE), complicating adequate IE treatment. Therefore, in addition to culture diagnostic methods, our clinical department uses a broad-range 16S and 18S rDNA polymerase chain reaction (PCR) and sequencing test to detect and identify IE agents.

Between 2009 and 2013, we performed 246 valve replacements due to endocarditis. In 46 patients with culture-negative IE or incongruent preoperative microbiological diagnostics, heart valve (HV) samples were PCR-analysed and PCR products subsequently sequenced for phylogenetic analysis.

The molecular diagnosis led us to change the antibiotic regimen in 7 of 46 patients.

The PCR results demonstrate that the molecular test is a useful diagnostic tool for the rapid diagnosis of IE. Furthermore, the molecular diagnosis had a significant, direct impact on the therapy of IE. This suggests that using PCR can improve antibiotic treatment, particularly in cases of culture-negative IE. Consequently, molecular analysis of micro-organisms in HV samples should be performed routinely where preoperative diagnosis remains unclear.