MULTIPLE RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM GENOTYPES OF PORPHYROMONAS-GINGIVALIS IN SINGLE PERIODONTAL POCKETS

A total of 188 Porphyromonas gingivalis strains isolated from 13 perio dontal pockets of 8 periodontitis patients were investigated by means of restriction fragment length polymorphism (RFLP) analysis using the fimA gene as a pobe. A total of 5 RFLP genotypes were identified, and over half of the isolates belonged to type I. Four of the 8 patients h arbored only 1 RFLP genotype of P, gingivalis, and 1 patient harbored only 2 RFLP genotypes in different sites. On the other hand, in 3 othe r patients, multiple RFLP genotypes were found in single periodontal p ockets. Further studies will be required to clarify whether multiple g enotypes of P. gingivalis colonized a single periodontal pocket simult aneously or whether a mutation occurred in the fimbrilin gene locus of P. gingivalis.