title: The prevalence and pathogenic differences of Porphyromonas gingivalis fimA genotypes in patients with aggressive periodontitis.
abstract: BACKGROUND
  The fimA gene, which encodes fimbrillin (FimA), is found in Porphyromonas gingivalis and has been classified into six genotypes based on nucleotide sequence. P. gingivalis that possesses the type II fimA gene is prevalent in adult periodontitis.
  
  
  OBJECTIVE
  The aim of this study was to investigate the prevalence of P. gingivalis fimA genotypes in Japanese aggressive periodontitis patients, and to examine their virulence.
  
  
  METHODS
  Subgingival plaque samples were obtained from 223 sites in 18 aggressive periodontitis patients and 95 sites in 22 periodontally healthy young adults. Actinobacillus actinomycetemcomitans, P. gingivalis and Tannerella forsythensis detection, determination of the fimA genotype in P. gingivalis, and the quantification of P. gingivalis were analyzed by polymerase chain reaction (PCR) methods. The proteolytic activities of the P. gingivalis fimA type I and fimA type II were also examined.
  
  
  RESULTS
  In aggressive periodontitis patients, the most prevalent fimA genotype was the type II (46.7%), followed by the type Ib and type I, whereas in healthy subjects, the type I fimA was the only genotype detected. The number of P. gingivalis pathogens was the greatest in the type I fimA positive sites, and the frequency of coexisting A. actinomycetemcomitans and T. forsythensis was highest in the type II fimA positive sites in the aggressive periodontitis patients. Both the arginine-specific cysteine proteinase (Arg-gingipain) and lysine-specific cysteine proteinase (Lys-gingipain) activity of the P. gingivalis fimA type I strain were significantly higher than those of the fimA type II strains.
  
  
  CONCLUSIONS
  These results suggest that differences in virulence exist among different fimA genotypes. Coadherence with other pathogens in P. gingivalis fimA type II-associated aggressive periodontitis and quantitative increases in P. gingivalis in fimA type I-associated aggressive periodontitis are related to this virulence.
authors.affiliation: Section of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Higashi-ku, Fukuoka, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Miura
authors.forename: Takafumi
authors.initials: T
authors.lastname: Hamachi
authors.forename: Osamu
authors.initials: O
authors.lastname: Fujise
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Maeda
mesh_terms: D000328:Adult; D016866:Bacteroidaceae Infections / Q000235:genetics*; D016009:Chi-Square Distribution; D005260:Female; D036781:Fimbriae Proteins / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008297:Male; D010518:Periodontitis / Q000453:epidemiology / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D018709:Statistics, Nonparametric; D014774:Virulence / Q000235:genetics
chemical_list: C063055:fimbrillin; D036781:Fimbriae Proteins