Genetic Diversity of Porphyromonas gingivalis Isolates Recovered from Single “Refractory” Periodontitis Sites

Multilocus sequence typing and fimA genotyping were performed on Porphyromonas gingivalis isolates from 15 subjects with “refractory” periodontitis. Several sequence types were detected for most individual pockets. The variation indicated recombination at the recA and pepO genes. The prevalence of fimA genotypes II and IV confirmed their association with periodontitis.