Microbiología clásica y molecular en el diagnóstico de la endocarditis infecciosa

Introduction and objectives

In recent years, molecular techniques for the aetiological diagnosis of infective endocarditis (IE) have attained relevance; however, they are not implemented in all laboratories. Our objective is to evaluate the usefulness of broad-spectrum polymerase chain reaction (PCR) technique followed by sequencing (universal PCR) on valve tissue as part of the IE diagnostic practice and to compare the results with classical methods.

Results

Universal PCR showed a higher sensitivity than valve culture (80.8 vs 27.1%, P < .001) and allowed the identification of the causative agent or the confirmation of the aetiological diagnosis in case of discordance in 7.7% of patients. Regarding conventional diagnosis, blood culture stands out as the reference technique and Gram staining due to its high positive predictive value. The highest sensitivity and specificity was obtained considering classical and molecular microbiology together. The anatomopathological study presented a sensitivity of 83.9% and made it possible to assess the results of the microbiological diagnosis when there were discrepancies.

Conclusions

Universal PCR proved to be a valuable technique that completes the classical diagnosis. In an entity as complex as IE, it is necessary to use all the diagnostic tools at our disposal. All areas of laboratory diagnosis are complementary and not exclusive and should be assessed together.