Bacterial DNA detected on pathologically changed heart valves using 16S rRNA gene amplification

Abstract

Nowadays, dental diseases are one of the most common illnesses in the world. Some of them can lead to translocation of oral bacteria to the bloodstream causing intermittent bacteraemia. Therefore, a potential association between oral infection and cardiovascular diseases has been discussed in recent years as a result of adhesion of oral microbes to the heart valves. The aim of this study was to detect oral bacteria on pathologically changed heart valves not caused by infective endocarditis. In the study, patients with pathologically changed heart valves were involved. Samples of heart valves removed during heart valve replacement surgery were cut into two parts. One aliquot was cultivated aerobically and anaerobically. Bacterial DNA was extracted using Ultra-Deep Microbiome Prep (Molzym GmbH, Bremen, Germany) followed by a 16S rRNA gene PCR amplification using Mastermix 16S Complete kit (Molzym GmbH, Bremen, Germany). Positive PCR products were sequenced and the sequences were analyzed using BLAST database ( http://www.ncbi.nlm.nih/BLAST ). During the study period, 41 samples were processed. Bacterial DNA of the following bacteria was detected in 21 samples: Cutibacterium acnes (formerly Propionibacterium acnes) (n = 11; 52.38% of patients with positive bacterial DNA detection), Staphylococcus sp. (n = 9; 42.86%), Streptococcus sp. (n = 1; 4.76%), Streptococcus sanguinis (n = 4; 19.05%), Streptococcus oralis (n = 1; 4.76%), Carnobacterium sp. (n = 1; 4.76%), Bacillus sp. (n = 2; 9.52%), and Bergeyella sp. (n = 1; 4.76%). In nine samples, multiple bacteria were found. Our results showed significant appearance of bacteria on pathologically changed heart valves in patients with no symptoms of infective endocarditis.

Awareness and practices of general practitioners towards the oral‐systemic disease relationship: A regionwide survey in France

“…22,23 It is clear that oral bacteria may enter the systemic circulation through discontinuities of epithelium in the periodontal lesion, and several studies have observed these bacteria in blood vessels, within arteriosclerotic plaques or pathological heart valves. 24 Substantial evidence has also been found of the oral origin of bacteria which cause pneumonia 25 and in the subversion of immune cells by periodontopathogens exacerbating the inflammatory response in IBD. 26 It was interesting to note that PD-carrying GPs seem to be more aware of the potential influence of PD on respiratory infections than GPs with no PD.…”

Bacterial infiltration in structural heart valve disease

“…21,26 In this way, we achieved a significantly improved microbiological detection of bacteria compared with conventional processing protocols. 10,17 Bacteria such as Clostridium difficile, 27 Enterococcus faecalis, 28 and Staphylococcus haemolyticus 29 are capable of forming a biofilm and thus show a higher resistance to antibiotics. This biofilm consists largely of extracellular matrix, and the dissolution of the biofilm permits better contact between medium and bacterium, with subsequent improvement of proliferation.…”

“…Polymicrobial findings are supported by the work of Chalupova and colleagues, 10 who provided evidence of coinfections of propionibacteria, staphylococci, and streptococci in a comparable disease collective applying 16S rDNA polymerase chain reaction and subsequent Sanger sequencing. 10 Furthermore, in patients requiring dialysis, the degree of prosthetic stenosis due to calcification is particularly pronounced. 36 It would be of great interest whether a correlation between recurrent chronic infection risk (dialysis) and the degree of structural heart valve disease can be found.…”

“…5,7 Molecular biological studies of the heart valve tissue of patients with sVHD have confirmed the detection of bacteria. 8,10 The literature reveals positive evidence for streptococci, 8 staphylococci, and Propionibacterium, 10 Chlamydophila, and Mycoplasma 11 on the basis of polymerase chain reaction studies. However, the method used by these authors does not provide any insight into the degree of polymicrobial infiltration.…”

Commentary: Bacterial infiltration in structural heart valve disease—Do these new insights have profound consequences?

“…2 In the case of structural heart valve disease (sVHD), classic risks such as hyperlipidemia, diabetes, hypertension, and deranged calcium metabolism are fairly well understood. Various investigators, however, have both detected bacteria in degenerated heart valve tissue 3 and have proposed mechanisms whereby bacteria promote tissue calcification 4 and therefore could have a role in the pathogenesis of sVHD. Nevertheless, the degree of polymicrobial infiltration discerned by these studies is limited, and the detection of bacteria has even been considered by some to represent contamination.…”