Ide, L.*, Lotufo, R.F.M., Contreras, A., Bergamashi, O., and SLOTS, J.,
Universidade de Sao Paulo, Sao Paulo, Brazil and University of Southern California, Los Angeles, CA, USA.

The periodontopathic microbiota in South American populations has only received little attention. This study determined the prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Campylobacter rectus, Treponema denticola and Eikenella corrodens in 2 native tribes in the Xingu Indian Park (Mato Grosso, Brazil). This remote population demonstrates relatively little periodontitis despite poor oral hygiene. A 16S rRNA polymerase chain reaction method was used for bacterial detection. Subgingival samples were collected with paper points from subjects (17-60 years of age) with gingivitis (n=49) and periodontitis (pocket depth > 5mm; n=36). 24% of gingivitis subjects and 61 % of periodontitis subjects yielded at least one of the test species. Bacteria-positive gingivitis subjects revealed an average of 1.2 and bacteria-positive periodontitis subjects an average of 2.9 test species. Gingivitis subjects were positive for P. gingivalis (18%), A. actinomycetemcomitans (8%) and E. corrodens (2%). Periodontitis subjects revealed P. gingivalis (53%), C. rectus (31%), B. forsythus (25%), P. intermedia (22%), A. actinomycetemcomitans (17%), T. denticola (17%) and E. corrodens (14%). P. gingivalis seems to constitute a major periodontal pathogen in native Brazilians. Most periodontal pathogens tested occurred less frequently in periodontitis subjects of the Xingu Indian Park than of Los Angeles, CA. The low prevalence of several periodontal pathogens in Xingu Indians may in part explain the relatively low level of destructive periodontal disease seen in this population.