Atherosclerosis is considered a chronic disease of the arterial wall and is the major cause of severe disease and death among individuals all over the world. Some recent studies have established the presence of bacteria in atherosclerotic plaque samples and suggested their possible contribution to the development of cardiovascular disease. The main objective of this preliminary pilot study was to better understand the bacterial diversity and abundance in human atherosclerotic plaques derived from common carotid arteries of individuals with atherosclerosis (Russian nationwide group) and contribute towards the further identification of a main group of atherosclerotic plaque bacteria by 454 pyrosequencing their 16S ribosomal RNA (16S rRNA) genes. The applied approach enabled the detection of bacterial DNA in all atherosclerotic plaques. We found that distinct members of the order Burkholderiales were present at high levels in all atherosclerotic plaques obtained from patients with atherosclerosis with the genus Curvibacter being predominant in all plaque samples. Moreover, unclassified Burkholderiales as well as members of the genera Propionibacterium and Ralstonia were typically the most significant taxa for all atherosclerotic plaques. Other genera such as Burkholderia, Corynebacterium and Sediminibacterium as well as unclassified Comamonadaceae, Oxalobacteraceae, Rhodospirillaceae, Bradyrhizobiaceae and Burkholderiaceae were always found but at low relative abundances of the total 16S rRNA gene population derived from all samples. Also, we found that some bacteria found in plaque samples correlated with some clinical parameters, including total cholesterol, alanine aminotransferase and fibrinogen levels. Finally, our study indicates that some bacterial agents at least partially may be involved in affecting the development of cardiovascular disease through different mechanisms.

Aim. To study the microflora composition of different localization atherosclerotic plaques in patients with atherosclerosis. Methods. 88 samples of atherosclerotic plaques were analyzed, including brachycephalic arteries - 71, the coronary arteries - 13, the aorta - 2, vessels of lower extremities - 2. The specimens were obtained from 71 men and 17 women aged 30-79 years (mean age 50.8 years). The presence of aerobic and anaerobic microflora was determined by bacteriological method. Detection of the cytomegalovirus nucleic acid, herpes simplex virus types 1 and 2, Epstein-Barr virus was performed by real time polymerase chain reaction. Results. The most diverse microflora was represented in the plaques of the neck vessels (carotid arteries). Thereat we found bacteria in 77.5% of the samples, including Propionibacterium acnes - 40.8%, the Staphylococcus genus - 50.7%. 83.3% Staphylococcus isolates were identified as S. epidermidis. In 14.1% of the samples from the brachycephalic artery plaques microorganisms associations (P. acnes and S. epidermidis) were found. The coronary arteries and aorta plaques microflora was represented entirely by P. acnes - 15.4 and 50% respectively. Herpes simplex virus type 1 and 2, and Epstein-Barr virus nucleic acids were detected in 6.7% of samples of carotid artery atherosclerotic plaques. Bacteria associations were presented exclusively in atherosclerotic plaques from brachycephalic arteries - 11.4% of the samples, including 9 bacteria (P. acnes and S. epidermidis) associations, and one association consisted of 3 microorganisms: 2 bacteria (P. acnes and S. epidermidis) and the virus (Epstein-Barr virus). Conclusion. Observed high frequency of microorganisms detection in studied atherosclerotic plaques samples allows to suggest their possible pathogenetic role in the blood vessels endothelium atherosclerotic lesions formation.

Aim of the study was to assess the frequency of microflora detection in the blood of patients with atherosclerotic vascular lesions and middle-aged patients without clinical symptoms of atherosclerosis. Compare the nature of microflora isolated from blood and the range of microorganisms isolated from atherosclerotic plaques (AP) of patients with carotid arteries atherosclerosis. Material and methods. The hemocultures of 118 men and 33 women with atherosclerosis (mean age 55.6 years) as well as 10 blood samples of 3 men and 7 women formed into a control group (mean age 37 years) were examined. Test samples were cultivated for 6 months. Tissue platings of carotid arteries AP in 11 women and 24 men of the main group (mean age 58.0) were incubated for 2 months. Methods based on Student’s t-test and Mann-Whitney U-test were used for statistical analysis of the obtained results. Results. Propionibacterium acnes hemocultures were detected in 9.9 % of patients from the main and control groups. In blood Staphylococcus epidermidis and Stenotrophomonas maltophylia were detected in 0.7 % of samples. P. acnes and Staphylococcus spp. cultures were obtained from AP in 34.3 and 45.7 %, including both microorganisms in 8.6 % of samples. Conclusions. P. acnes cultures are found equally frequently in the blood of atherosclerotic patients and patients not yet diagnosed with atherosclerosis. This study confirmed the presence of the same-name microorganisms in blood and atherosclerotic plaques. In 5.7 % (2 of 35) it was possible to extract simultaneously a P. acnes culture from two loci (atherosclerotic tissue and blood) in specific individuals. Further detailed research is required to study the etiological significance of the microbial factor in the atherosclerotic plaque formation.