VIABILITY OF 4 PUTATIVE PERIODONTAL PATHOGENS AND ENTERIC RODS IN THEANAEROBIC TRANSPORT MEDIUM VMGA-III

The aim of this study was to determine the survival in VMGA III of Por phyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans and enteric rods in laboratory c ultures as well as in subgingival plaque samples. Laboratory strains o f the 4 putative periodontal pathogens and Escherichia coli were used in the laboratory part of the study. Also, 31 subgingival plaque sampl es were obtained from 22 periodontal patients and stored in VMGA III. Each sample, from both the laboratory and the clinical parts, was divi ded into 3 portions. One portion was cultured within a few hours of co llection (baseline), while the second was processed after 24 h (day 2) and the third 48 h later (day 3). The results of the clinical part in dicate that the detection frequencies of all 4 periodontal pathogens a nd their levels in positive samples decreased, to different degrees, b y day 2 and decreased further by day 3. Enteric rods were not detected in baseline samples. However, they were present in 16.1% and 22.6% of day 2 and day 3 samples, respectively. Similarly, the laboratory resu lts demonstrate a significant decrease in the levels of the 4 periodon tal pathogens tested by day 2 and day 3, whereas the opposite occurred for E. coli. P. gingivalis, P. intermedia, and F. nucleatum survived better in the presence of E. coli than alone, whereas A. actinomycetem comitans survived less well when co-inoculated with E. coli. VMGA III appears to maintain microbial population ratios for periods up to 24 h . After 24 h, the multiplication of enteric organisms may alter the or iginal proportions of the sample.