2 Identification, pathogenesis and chemical composition of the exopolysaccharides of clinical isolates of exopolysaccaride-producing black-pigmented Gram-negative anaerobic rods

Abstract

We examined the biofilm forming capacity of 74 clinical isolates of black-pigmented Gram-negative anaerobic rods isolated from periodontal lesions. Two strains (OD 1-2 and OD 1-16) were obtained and identified as Prevotell intermedia (P. intermedia). Exopolysaccharide (EPS) from strain OD 1-16 cultures consisted primarily of polysaccharide that was 62% mannose. Compared to the non-EPS-producing strain, ATCC 25611, strain OD 1-16 had a higher capacity to induce abscess formation in mice. Our results suggest that P. intermedia can produce large amounts of exopolysaccharide, form biofilm, and play an important role in the development of biofilm infections in the oral cavity.