Microbial diagnosis of periodontal pathogens

Introduction Periodontal disease is related to the chronic inflammation involving the supporting structures of the teeth (periodontium). Beginning and progression of disease are closely associated with the presence of anaerobic Gram negative bacteria in the gingival crevice. Because of the complexity of this flora, its identification requires either traditional methods (i.e. microscopy and cultural methods) or molecular approach (PCR, Polymerase Chain Reaction) in order to achieve results that may be useful from a clinical point of view.We have studied the flora from periodontal pockets of 41 subjects with a clinical diagnosis of periodontitis. Methods The subgingival samples were collected using sterile paper points inserted subgingivally and inoculated onto appropriate plating media: blood agar, kanamycin vancomycin laked blood (KVLB), and NOS medium (New Oral Spirochetes).After incubation in anaerobic environment, a detailed colony description was recorded in particular with regard to size, shape, color, and pigment.The identification was performed by API20 system (bioMérieux). Molecular study was carried out by PCR method, using whole genomic DNA. Results Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Treponema denticola were the most commonly strains isolated. Conclusions Both traditional and molecular approach are needed to identify the bacterial flora associated with periodontal disease. This approach represents an important strategy to either support the clinical diagnosis or control the extent of the disease. Furthermore, the possibility to evaluate the susceptibility pattern of antibiotic resistance among bacterial isolates might be important in view of the new antibiotic resistance recently described for those periodontal bacteria.