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

OBJECTIVES: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: These results indicated that in subjects without periodontitis, the transmission of oral bacteria to atherosclerotic plaques of the carotid artery is a feasible event. CLINICAL RELEVANCE: The prevention of transient bacteremia from the oral cavity requires high levels of oral health.

Synthesis of new carolacton derivatives and their activity against biofilms of oral bacteria.

Carolacton, a secondary metabolite isolated from the extracts of Sorangium cellulosum, causes membrane damage and cell death in biofilms of the caries- and endocarditis-associated bacterium Streptococcus mutans. Here, we report the total synthesis of several derivatives of carolacton. All new structural modifications introduced abolished its biological activity, including subtle ones, such as inversion of configuration at C9. However, a bicyclic bislactone derivative as well as the methyl ester of carolacton resulted in compounds with prodrug properties. Their inhibitory activity on S. mutans was proven to be based on enzymatic hydrolysis by S. mutans which provided native carolacton resulting in biofilm damage in vivo. Moreover, we demonstrate that carolacton acts also on S. gordonii, S. oralis and the periodontitis pathogen Aggregatibacter actinomycetemcomitans, causing elongated cells and growth inhibition.

16S rDNA-based metagenomic analysis of human oral plaque microbiota in patients with atherosclerosis and healthy controls.

To address the question if an altered oral microbiota is associated with atherosclerosis. Twenty patients suffering from atherosclerosis and 10 controls were recruited. Clinical oral, medical and laboratory investigations were performed. Oral bacteria were collected and 16S rDNA was sequenced following Single strand conformation polymorphism.(SSCP) Probing pocket depths in patients were significantly elevated. The oral microbiota of patients and controls were dominated by Fusobacterium (16%/17%), Streptococcus (21%/14%), Prevotella (10%/12%), Enterococcus (12%/12%), Porphyromonas (8%/7%), TM7 (0%/7%) and Veillonella (6%/7%). Differences in diversity were not significant between groups. The pathology of atherosclerosis may not be related to significant qualitative changes of the oral microbiota.