Bacterial DNA signatures in carotid atherosclerosis represent both commensals and pathogens of skin origin

Infectious agents have been suggested to be involved in atherosclerosis. By using a novel subtraction broad-range PCR approach, we defined bacterial DNA signatures in surgically removed sterile carotid artery endarterectomy plaques of patients with carotid atherosclerosis. Eighty partial bacterial 16S rDNA nucleotide sequences from eight patients were studied. Furthermore, 34 clones representing 21 bacterial sequence-types from the reagents used for DNA extraction and PCR amplification were determined. After subtraction of these potential methodological contaminants, 23 bacterial sequence-types were considered as clinically relevant findings. The most prominent phylum, Actinobacteria, accounted for 74% of these relevant sequences. Furthermore, according to the Human Microbiome project database, interestingly, nearly all (94%) of the sequences were associated with the human skin microbiome.