The diagnostic benefit of 16S rDNA PCR examination of infective endocarditis heart valves: a cohort study of 146 surgical cases confirmed by histopathology

Abstract

Aims Upon suspicion of infective endocarditis, the causative microorganism must be identified to optimize treatment. Blood cultures and culturing of removed valves are the mainstay of this diagnosis and should be complemented by growth-independent methods. We assessed the diagnostic benefit of examining removed endocarditis valves by broad-range bacterial PCR to detect causative bacteria in cases where culturing was not available, negative, or inconclusive because a skin commensal was detected, in patients from our clinical routine practice. Methods and results Patients from Heidelberg University Hospital with suspicion of endocarditis, followed by valve replacement and analysis by 16S rDNA PCR, between 2015 and 2018, were evaluated. 146 patients with definite infective endocarditis, confirmed by the valve macroscopics and/or histology, were included. Valve PCRs were compared to corresponding blood and valve culture results. Overall, valve PCR yielded an additional diagnostic benefit in 34 of 146 cases (23%) and was found to be more sensitive than valve culture. In 19 of 38 patients with both negative blood and valve cultures, valve PCR was the only method rendering a pathogen. In 23 patients with positive blood cultures detecting skin commensals, 4 patients showed discordant valve PCR results, detecting a more plausible pathogen, and in 11 of 23 cases, valve PCR confirmed commensals in blood culture as true pathogens. Only the remaining 8 patients had negative valve PCRs. Conclusion Valve PCR was found to be a valuable diagnostic tool in surgical endocarditis cases with negative blood cultures or positive blood cultures of unknown significance. Trial registration S-440/2017 on 28.08.2017 retrospectively registered. Graphic abstract Subdividing of all infective endocarditis patients in this study, showing that valve PCR yields valuable information for patients with skin commensals in blood cultures, which were either confirmed by the same detection in valve PCR or refuted by the detection of a different and typical pathogen in valve PCR. Additionally, benefit was determined in patients with negative or not available blood cultures and only positive detection in valve PCR. +: Positive; −: negative; n/a: not available results

Evaluation of 16S rDNA Heart Tissue PCR as a Complement to Blood Cultures for the Routine Etiological Diagnosis of Infective Endocarditis

“…Molecular analysis of heart valves was found to be the only method to establish the etiology of BCNE, giving consistent results in 16 out of 44 patients (36%). These results agree with recent articles where 16S rDNA valve PCR was positive in 41% of surgical blood culture-negative endocarditis [20].…”

“…Furthermore, the performance of 16S rDNA PCR in our study was useful to interpret blood culture results, for instance, to confirm infections by bacteria from the skin microbiota, a benefit that has already been highlighted in other works [20].…”

Clinical and diagnostic value of including PCR blood test in the traditional algorithm for identifying causative agents of infective endocarditis: a cohort study of 124 patients

“…), K. Armstrong (2021 г.) и соавт., показавших, что ПЦР-исследование имеет большое диагностическое значение для ИЭ неустановленной этиологии или играет важную роль для уточнения результатов ранее проведенного микробиологического исследования [5,10,11,14]. Однако следует отметить, что проведенные исследования больше были направлены на выявление преимуществ ПЦР-исследования тканей резецированных клапанов, частично включая результаты ПЦР-исследования крови, в связи с чем представляемое исследование параллельного включения ПЦР крови в алгоритм этиологической диагностики ИЭ на ранних этапах является практичес ки не изученным ранее.…”

“…), а также ра-нее представленными нами данными (47,2%, 2016 г.) [1,2,5,10,11,[14][15][16]. Такие неприемлемо высокие показатели ИЭ с неустановленной этиологией в первую очередь, вероятно, связаны с бесконтрольным длительным приемом АБП пациентами до проведения исследования крови, что приводит к тому, что исходно низкая бактериемия при ИЭ становится еще менее выраженной, определяя получение отрицательных результатов микробиологического исследования крови, даже несмотря на наличие типичных и легко культивируемых возбудителей.…”

Native valve, prosthetic valve, and cardiac device-related infective endocarditis: A review and update on current innovative diagnostic and therapeutic strategies

“…Several metagenomic techniques exist. A broad-range PCR technique that can be combined with next generation sequencing called 16S rDNA or 16S rRNA analysis has been successfully used for bacterial detection ( Oberbach et al, 2017 ; Boujelben et al, 2018 ; Armstrong et al, 2021 ). Currently, PCR in IE can only be used to determine which bacteria are on valve- and other infected tissue retrieved after surgical intervention.…”