Prevotella intermedia has been implicated as a potent pathogen in many kinds of periodontal, pulpal and
periapical diseases. However, it has been isolated from periodontally healthy
adults and from edentulous
children as well. The intraspecies heterogeneity of
Prevotella intermedia has been demonstrated in early studies and finally Shah & Gharbia confirmed the existence of 2
DNA homology groups and proposed dividing
Prevotella intermedia into 2 species,
Prevotella intermedia and
Prevotella nigrescens. This study was designed to examine the frequency of
Prevotella intermedia and
Prevotella nigrescens in diseased
periodontal pockets and healthy gingival sulcus of Korean people by
PCR based on 16s
ribosomal DNA sequence. One hundred
adults who had
adult periodontitis but not taken any periodontal
treatment or
antibiotics during previous 6 months and 50
adults who had healthy periodontal
tissue were selected for this study. The sulcular fluid was collected into VMGA by sterilized
paper point and diluted to 1,000 times in anaerobic chamber. 100ml of sample was cultured in 37degrees C for 10 days. Among the bacterial colonies, BPB were selected and cultured in BHI broth and then
Prevotella intermedia was identified through Gram
staining and biochemical test. Identified
Prevotella intermedia was cultured again and centrifuged.
DNA was extracted from the pellet using several
reagents.
PCR was performed by previously designed primer. The results were followed. 1.BPB were isolated from 39 of 100 samples of diseased
periodontal pockets(39%). 2.
Prevotella intermedia was identified from 24 of 39 BPB samples. 3.Among 24
Prevotella intermedia, 21 were confirmed as
Prevotella intermedia(87.5) and 2 were confirmed as
Prevotella nigrescens(8.33%). 4.BPB were isolated from 9 of 50 samples of periodontally healthy
patients. Among them only two were identified as
Prevotella intermedia, that is, one was confirmed as
Prevotella intermedia and the other was
Prevotella nigrescens.