Molecular Diagnosis of Bacterial Definite Infective Endocarditis by Real-Time Polymerase Chain Reaction

Abstract

Infective endocarditis (IE) can be diagnosed using the Duke criteria, which cannot be conclusive especially when the results of blood cultures are negative. This study aimed at using real-time polymerase chain reaction (PCR) technique to isolate bacteria present in whole blood samples of patients with definitive IE on the basis of the method designed in this study. This laboratory and test study was conducted on 20 whole blood samples taken from patients with definitive IE. Real-time PCR of the 16s rRNA was utilized to directly analyze whole blood samples to diagnose bacterial IE. Of 20 whole blood samples with definitive IE, only one blood culture (5%) was positive and the isolated bacterium belonged to Streptococci viridans group. Also, 13 whole blood samples were positive using real-time PCR technique. The isolated bacteria were Enterococcus faecalis with seven (35%) cases, Streptococcus gallolyticus with two (10%) cases, Streptococcus mutans with one (5%) case, Streptococcus sanguinis with one (5%) case, Streptococcus salivarius with one (5%) case, and Staphylococcus aureus with one (5%) case. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) using real-time PCR technique were 65%, 100%, 100%, and 74%, respectively. The developed real-time PCR method allows us to detect bacteria in whole blood samples and is much more sensitive than culturing method. It also permits the differentiation of the main group of bacteria within a few hours for IE.

Impact of Healthcare-Associated Infections Connected to Medical Devices—An Update

“…In addition, the development of MDR bacterial strains and drug-tolerant microbial biofilms is not rare [161,162]. Blood culture negative infective endocarditis can be caused by fungi or fastidious bacteria, notably by obligatory intracellular bacteria [163]. Testing for Coxiella burnetii, Bartonella spp., Mycoplasma pneumoniae, Brucella spp., and Legionella pneumophila should be proposed, followed by atypical bacteria such as Tropheryma whipplei, Bartonella spp., and fungi (Candida spp., Aspergillus spp.)…”

Expression of oxidative stress markers in native heart valves obtained from patients with infective endocarditis

“…Зачастую развитие ИЭ ассоциировано с бактериальной инфекцией, которая изначально поражает эндокардиальную поверхность сердца. Течение ИЭ зависит от активности воспалительного процесса, патогена, а также от реакции организма пациента [2]. Среди патогенов, поражающих клапанные структуры сердца, в большинстве случаев превалирует золотистый стафилококк, проникающий в эндотелиальные клетки, что впоследствии может приводить к повреждению эндотелиального слоя.…”

DMBT1 involvement in the human aortic endothelial cell response to Streptococcus mutans

“…Nakano et al () demonstrated that S. mutans was the most frequently detected species among oral streptococci in the cardiovascular specimens, with the detection rates in the heart valve and aneurysm wall specimens being 42.7% and 62.8%, respectively. S. mutans has also been detected in blood samples taken from patients with infective endocarditis (Faraji et al, ; Kim, Gordon, & Shrestha, ). In animal experiments, S. mutans caused infective endocarditis (Nagata et al, ) and accelerated atherosclerosis (Kesavalu et al, ).…”