Gingival crevice microbiota from Chinese patients with gingivitis or necrotizing ulcerative gingivitis.

The objective of this study was to quantitatively compare the bacterial population structure in plaque from the gingival margin of two groups of 21 Chinese patients with gingivitis or necrotizing ulcerative gingivitis (NUG). Subjects were recruited in four dental clinics in Eastern China. Samples were quantitatively assessed by immunofluorescence and fluorescent in situ hybridization for taxa known to be associated with periodontal diseases. The analyses showed that the fusiform taxa (Fusobacterium nucleatum/Fusobacterium periodonticum, Leptotrichia buccalis, Tannerella forsythensis, and Capnocytophaga sp.), Campylobacter rectus, Prevotella intermedia, Prevotella nigrescens, Selenomonas sputigena, and treponemes were present in both groups with high prevalence. Porphyromonas gingivalis and Actinomyces gerencseriae were much more prevalent in the NUG group. Quantitatively, most taxa, including P. gingivalis, F. nucleatum and the treponemes, accounted, on average, for < 3% of the total bacterial cell number. Only P. intermedia/P. nigrescens, P. gingivalis, S. sputigena, A. gerencseriae, and the sum of all monitored suspected periodontal pathogens were significantly increased in the NUG group. The present study demonstrates for both groups a highly diverse plaque composition and suggests that, etiologically, the overall concentration and the concerted effects of the entire group of opportunistic pathogens thriving in NUG-associated plaque are of prime importance.