Distribution Of Porphyromonas Gingivalis Strains With FimA Genotypes In Puberty Gingivitis Patients And The Ultrastructure Observation

ObjectiveThe studies aimed to detect Porphyromonas gingivalis ( P. gingivalis ) in subgingival plaque samples collected from puberty gingivitis patients and puber-tal periodontally healthy subjects by species - specific 16S rRNA polymerase chain reaction ( PCR);then assess the fimbriae genotypes in P. gingivalis positive samples by fimA type - specific PCR and observe the ultrastructure, to explore the relationship between P. gingivalis and puberty gingivitis and find the distribution of fimA genotypes of P. gingivalis in puberty gingivitis patients and pubertal periodontally healthy subjects subgingival plaque samples, and the ultrastructure properties associated with pathogenicity.MethodsThe prevalence of P. gingivalis was analyzed in 51 subgingival samples obtained from puberty gingivitis patients and 46 ones from pubertal periodontally healthy subjects in the first part of the present studies. The subgingival plaque samples were taken from incisors and first molars with sterile subgingival curets. P. gingivalis strains cultured previously were selected as would be observed.Genomosomal DNA was isolated from samples and P. gingivalis strains with phenol and chloroform. P. gingivalis was detected by species - specific16S rRNA PCR, and then the fimA genotypes in P. gingivalis positive samples were assessed by fimA type - specific PCR. The cells were observed under transmission electron microscope by ultrathin section. Statistical analysis were performed by chi - square test.ResultslxThe detection rate of P. gingivalis by species - specific 16S rRNA PCR in puberty gingivitis patients was 74. 5% , and pubertal periodontally healthy subjects 30. 4% , statistically significant difference was observed between them (P < 0. 01 ). A significant relationship was identified between detection rate growth and increase of age in puberty gingivitis patients (P <0. 05 ) and pubertal periodontally healthy subjects (P <0. 01).2%The subgingival plaque samples of puberty gingivitis patients and pubertal periodontally healthy subjects were isolated different/i/n/l genotypes. The distribution oifimA genotypes of P. gingivalis in puberty gingivitis patients: type I, 34.2%;type II , 55.3%;type IV, 18.4%;type I and typeV were not detected;a fimA genotype was not identified in 7 samples (18.4%). The distribution oifimA genotypes of P. gingivalis in pubertal periodontally healthy subjects;type I, 14. 3%;type II , 85.7%;type IV, 28. 6%;type 1, 14. 3%;typeVwas not detected;a.fimA genotype was not identified in 2 samples (14. 3%).3 > There were differences in the fimbriae among fimA genotype I x II and IV P. gingivalis : type I and II possessed numerous fimbriae on the surface and type II possessed more likely, but no obvious fimbriae was observed in type IV. In the meantime, the differences of capsule among them were also observed: the capsule of type I was the thickest, type IV was less than type I , and type II only had a very thin layer.Conclusion1N P. gingivalis was related to puberty gingivitis.2xThe detection rates of P. gingivalis increased with age in puberty.3 % Genetic diversity of P. gingivalis existed in the subgingival plaque of puberty gingivitis patients and pubertal periodontally healthy subjects. The most prevalent fimA genotype was type II , followed by type I and IV, type M and V even could not be detected.4 x Other untypeable fimA genotypes may be present in the subgingival plaque of puberty gingivitis patients and pubertal periodontally healthy subjects.S^The fimbriae and capsule differed in fimA genotype I > II and IV P. gingivalis . Maybe the differences of adhesion x invasion or other pathogenic capabilities were not only caused by fimbriae, but also caused by capsule or other factors.