The Occurrence Of Actinobacillus Actinomycetem-comitans In Buccal Mucosa And Subgingival Plaque From The Chronic And Aggressive Periodontitis Patients

ObjectiveThe aim of this study was to determine the distribution patterns of Actinoba-cillus actinomycetemcomitans in buccal mucosa and subgingival plaque from per-iodontally healthy subjects, chronic and aggressive periodontitis patients using a PCR method, and to relate Actinobacillus actinomycetemcomitans (A. a) to host cells using Fluorescent In Situ Hybridization (FISH) and Laser Scanning Confo-cal Microscopy ( LSCM) . A better understanding of the etiology may be offered for the therapy and prevention of periodontitis.Methods30 patients with chronic periodontitis (CP) ,12 with aggressive periodontitis (AgP) and 15 periodontally healthy individuals as healthy control participated in the present study. All subject participants were healthy and had not undergone periodontal or antibiotic therapy for at least 3 months prior to sampling. Subgingival microbial samples were collected from the 1st,4th and 6th teeth sites of periodontal pockets at the same quadrant among CP,AgP and healthy individuals. Cheek epithelial cells were obtained from mucosa of both cheeks with two sterile cytological brushes each subject. One for PCR, the other for FISH. Genomic DNA was extracted with phenol and chloroform from samples and was amplified with universal primers and A. a species - specific primer.Bacterial universal probe and A. a species - specific probe designed were marked TAMRA and FITC respectively and used for FISH. LSCM was used todetermine whether bacteria detected by FISH were inside buccal epithelial cells from human subjects.Results1,The frequency detected in PCR was as follows : A. a was detected in a high percentage of AgP groups in both subgingival microbial samples and buccal mucosa samples (41.7% respectively) , but in a low percentage of CP groups (16. 7% and 10% respectively) . None was A. a positive in periodontally healthy individuals. Highly statistically significant differences were observed between detection of A. a of buccal mucosa samples in AgP and CP groups ( X2 = 5.57,P <0.05) . The same highly statistically significant differences were exited between detection of A. a of buccal mucosa samples and subgingival microbial samples in periodontally healthy individuals and AgP groups (P =0.009) .2,In the CP groups,the relative quantity of A. a was 19% in subgingival microbial samples and 12. 75% in buccal mucosa samples . In the AgP groups , the relative quantity of A. a was 38. 5% in subgingival microbial samples and 22.2% in buccal mucosa samples . Highly statistically significant differences were observed between buccal mucosa samples and subgingival microbial samples in AgP groups (P <0. 05). The same relations were exited between AgP groups and CP groups in the subgingival microbial samples (P <0.05) .3,The age (26. 32 ± 8. 33 ) of A. a - positive patients was younger than that (41.53 ±11.56) of A. a - negative patients (t=3.658 ,P <0.01) .4 , Correlation analysis showed that the relative quantity of A. a in subgingival microbial samples moderately related to PlI,GI and PD between AgP groups and CP groups (P<0.05) .5,It found that all of the subject participants buccal epithelial cells were infected with intracellular bacteria .6, Highly statistically significant differences of relative proportion of A. a in a buccal epithelial cell of study subjects were observed between AgP and CP groups ( at 60 - 100% , P < 0.01) . A. a - positive was detected in only 1 of the healthy individuals .