Analysis of porphyromonas gingivalis kgp gene polymorphism in periodontitis patients with diabetes

Background: To analyze the distribution of Porphyromonas gingivalis (P. gingivalis) kgp genotype in subgingival plaque of patients with diabetic periodontitis. The genetic polymorphism of the kgp gene in diabetic periodontitis was explored, and the correlation between different genotypes and diabetic periodontitis was obtained. Methods: Subgingival plaque samples were collected from 49 patients with periodontitis (21 with diabetes, 28 with non-diabetic periodontitis) and 11 healthy periodontal subjects. DNA was extracted, and the positive samples of P. gingivalis were screened by PCR with specific primers of 16S rRNA gene of P. gingivalis, and the fragment of kgp catalytic domain was obtained by PCR with specific primers of kgp. The genotype of kgp was determined by Mse I digestion of the catalytic domain fragment of kgp, and the experimental data were analyzed by the Pearson χ2 method. Results: Among the 11 healthy periodontal population samples collected in this study, 4 cases (36.4 %) of P. gingivalis were detected. Among 49 subgingival plaque samples of periodontitis, 47 patients (95.9 %) were detected with P. gingivalis. There was a statistical difference between the two. Among the 47 samples with P. gingivalis, the detection rate of kgp I was 57.4 %, the detection rate of kgp II was 31.9 %, and the detection rate of kgp I + II was 10.6 %. The kgp genotype was not associated with diabetes. There was no significant difference in the kgp genotypes between the two groups with different PD depths. Conclusion: P. gingivalis is associated with periodontitis. P. gingivalis kgp gene polymorphism exists in patients with diabetic periodontitis subgingival plaque.