RESUMEN
BACKGROUND: Porphyromonas gingivalis, a major periodontal pathogen, is gaining increasing attention for its possible association with atherosclerosis. Its fimbriae are classified into six genotypes (Types I-V, Ib) based on the diversity of the fim A genes encoding the fimbrial subunits. In this study, fim A genotype's distribution of P. gingivalis was analyzed in atherosclerotic plaque specimens. METHODS: A total of 50 atherosclerotic plaque specimens and 50 non-atherosclerotic, post stenotic aneurysm specimens were collected from patients undergoing cardiovascular surgery. Bacterial DNA was also extracted from each specimen, as real-time PCR was carried out with P. gingivalis-specific primer sets. The positive specimens of P. gingivalis were further analyzed to discriminate the fim A genotype using real-time and nested PCR methods. RESULTS: P. gingivalis was detected only in one atherosclerotic plaque; however, the genotype was nontypable in this specimen. CONCLUSIONS: We state that it is not easy to show a significant relationship between P. gingivalis, its fim A genotype, and atherosclerosis. We suggest that new extended studies based especially upon the quantitave determination of P. gingivalis and its genotype distribution on atherosclerotic specimens are needed to show an evident relationship between atherosclerosis and P. gingivalis.