Streptococcus mitis and Gemella haemolysans were simultaneously found in atherosclerotic and oral plaques of elderly without periodontitis-a pilot study.

Abstract

Local infections may contribute to the initiation and progression of several clinical diseases in humans. Atherosclerotic plaques of subjects suffering from periodontitis are colonized by periopathogens; however, the presence of bacteria in atherosclerotic plaques in patients without severe forms of periodontitis is of high relevance for the general population. Patients who were electively treated for atherosclerotic lesions of the carotid artery and without clinical signs of periodontitis were eligible for the study. Oral and atherosclerotic plaques were sampled, processed, and analyzed for their microbial composition by 454-sequencing. Seventeen patients were included in the analyses, and 76% of all atherosclerotic plaque specimens were positive for bacterial DNA. In the oral plaques, 76,532 sequences were identified representing 1 phylum, 17 classes, 112 families, and 263 genera. In atherosclerotic plaques, 6112 sequences representing 1 phylum, 4 classes, 8 families, and 36 genera were found. The bacterial DNAs of the species Gemella haemolysans and Streptococcus mitis were simultaneously found in atherosclerotic as well as oral plaque samples of 3 patients. These results indicated that in subjects without periodontitis, the transmission of oral bacteria to atherosclerotic plaques of the carotid artery is a feasible event. The prevention of transient bacteremia from the oral cavity requires high levels of oral health.