Pigmented Prevotella species in the periodontally healthy oral cavity.

Pigmented Prevotella spp. have been connected with oral infections as well as being part of the healthy gingival flora. The aim of this study was to determine the presence of pigmented Prevotella spp. in saliva and gingival crevice samples from periodontally healthy adults. Twelve Caucasian female subjects (mean age 28 years, range 21-36 years) with no pockets > or = 4 mm, nor bleeding after probing were selected for this study. Paraffin-stimulated saliva was collected first; then, a pooled subgingival bacterial sample was taken with a sterile curette from mesiobuccal surfaces of all first molars. The samples were inoculated on to non-selective and selective media and incubated anaerobically. The most frequent species isolated were Pr. melaninogenica, Pr. intermedia and Pr. loescheü, found in 11, ten and nine subjects, respectively. The mean percentage of the total cultivable anaerobic microflora in salivary/subgingival samples were 14.7/0.6 for Pr. melaninogenica, 3.1/5.3 for Pr. intermedia and 2.6/1.2 for Pr. loescheii. Pr. denticola was found in one saliva sample and Pr. corporis, in two subgingival samples only. The number of different pigmented Prevotella spp. in the same mouth was 2-4 (mean 2.75). In conclusion, Pr. melaninogenica, Pr. intermedia and Pr. loescheii seem to be common microorganisms in the periodontally healthy oral cavity.