Adhesive properties of streptococcus sanguis isolated from patients with behçet's disease

Various strains of Streptococcus sanguis adhered to the buccal epithelial cells from both healthy controls and patients with Behçet's disease (BD). Almost all of them strongly adhered to the epithelial cells from patients with BD, whereas smaller numbers of the bacteria were observed on the cells from healthy controls. This phenomenon was especially clear when uncommon serotypes (clinical isolates) were used. Two or more peaks were observed in the distribution of the epithelial cells from patients with BD in the adherence test. In contrast, a single peak was observed in the distribution of the epithelial cells from healthy controls. Cytological differences of the epithelial cells between both groups were not observed in the microscopic image analysis. All the strains of S.sanguis showed agglutination of rabbit erythrocytes, but not agglutination of sheep, horse, swine and duck erythrocytes. Line cell adherence of S.sanguis uncommon serotypes was greater than that of common ones. All strains of S.sanguis showed a reactivity with aggregated human β₂-microglobulin, but not with the monomer. The different level of reactivity to aggregated β₂-microglobulin was recognised between uncommon and common serotypes. The reaction between aggregated β₂-microglobulin and S.sanguis is one of human-bacterium interaction which should be considered in studies of BD.