Coculture method for in vitro cultivation of uncultured oral bacteria

Purpose: The purpose of the study is to culture uncultured oral bacteria with helper strains using the coculture method from the subgingival plaque samples of chronic periodontitis patients. Materials and Methods: The samples were processed and inoculated on a blood agar medium enriched with hemin and Vitamin K. A helper strain Propionibacterium acnes (ATCC 6919) was cross-streaked across the inoculums to facilitate coculture. The plates were then incubated for 7 days with subsequent subculturing and further incubation. Results: Satellite colonies around helper strain showed one colony type of Porphyromonas gingivalis, one was of nonpigmented Prevotella, three were of Fusobacterium nucleatum and five isolates remained unidentified. Conclusions: Coculture could be used effectively as one of the methods in the isolation and in vitro cultivation of oral bacteria. Incubation using the anaerobic jar technique was found to be economical and efficient for the growth of anaerobic oral bacteria.