Infective Endocarditis – Value of 16S/18S Broad-Range rDNA Diagnosis of Pathogens

Infective endocarditis (IE) is a serious disease with an incidence of up to 10 episodes per 100,000 person years and a relatively high mortality [up to 20%]. IE is diagnosed by clinical review, echocardiography, vegetation on heart valves and blood culturing. A major limitation is that blood culture stays negative in up to 31% of cases and is limited in the detection of rare pathogens and mixed infections. Culture-negative IE may cause delayed or inappropriate antibiotic treatment with potentially negative clinical outcome. Broad-range PCR targeting bacterial and fungal rRNA genes together with amplicon sequencing is an evaluated, widely used method of IE pathogen diagnosis. In-house PCR methods, however, are under risk of low sensitivity and false positive results due to DNA contamination of reagents, consumables and other materials used for sample preparation and PCR analysis of heart valves. In this application note clinical results of latest studies are discussed that involved protocols of Molzym’s DNA-free reagents and DNA-extraction kits for the direct broad-range PCR and sequencing diagnosis of heart valves for bacterial and fungal pathogens.