Introduction: Porphyromonas gingivalis, a major periodontal pathogen, is gaining increasing attention for its possible association with cardiovascular diseases. Its fimbriae are classified into six genotypes (types I-V and Ib) based on the diversity of the fimA genes encoding the fimbrial subunits. In this study, fimA genotypic distribution was analyzed in P. gingivalis-infected cardiovascular specimens.
Methods: A total of 112 heart valves and 80 atheromatous plaque specimens were collected from patients undergoing cardiovascular surgery, as well as 56 dental plaque specimens. Bacterial DNA was extracted from each, and polymerase chain reaction analysis was carried out with a P. gingivalis-specific set of primers. P. gingivalis-positive specimens were further analyzed to discriminate the fimA genotype using polymerase chain reaction with fimA type-specific primer sets.
Results: P. gingivalis was detected in 10.4% of the cardiovascular specimens and 50.0% of the dental plaque samples. In the latter, type II was most frequently detected (35.7%), followed by types I (28.6%) and IV (21.4%), while types IV and II were detected with considerable frequencies of 45.0% and 30.0%, respectively, in the cardiovascular specimens. In contrast, the occurrence of type I was limited (5.0%) in the cardiovascular specimens.
Conclusion: These results suggest that specific fimA genotypic clones, which are reportedly associated with periodontitis, are also frequently harbored in cardiovascular specimens, indicating the possible involvement of type II and IV clones in the initiation and progression of cardiovascular diseases.