Survival in transport media of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in human subgingival samples.

The purpose of this study was to evaluate the survival in 3 transport media of 3 suspected periodontal pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia. Subgingival samples were taken from 10 patients with severe periodontitis, all harboring at least two of the above-mentioned species. The material was dispersed and aliquots were added to vials containing reduced transport fluid, reduced transport fluid containing 10% Fildes extract, or viability-maintaining microbiostatic medium, anaerobically prepared (VMGA III). Viable counts were determined after 1, 2, 4, 24 and 48 h of storage at 4 degrees C or at room temperature. The results showed that, for up to 4 h of storage, no significant differences existed for all parameters tested. A large increase of the total viable counts was found in VMGA III at room temperature after 24 and 48 h. This was due to an outgrowth of mainly streptococci. Incubation at 4 degrees C yielded often a significantly higher recovery compared to room temperature. After storage at room temperature, the tested bacteria were below detection level in some samples.