Involvement of N-acetyl-D-galactosamine-specific lectin in biofilm formation by the periodontopathogenic bacterium, Eikenella corrodens

Eikenella corrodens is known not only as one of the periodontopathogenic bacteria but also as a pathogen associated with many infectious diseases of humans. Dental plaque is a complex biofilm community comprised of many bacterial species. E. corrodens has a lectin on its cell surface that is thought to be involved in its pathogenicity. In this study, we found that E. corrodens forms a biofilm on a polystyrene surface. A biofilm was formed at the bottom of the wells in microtiter plates after 24 h. Microcolonies were observed as the amount of biofilm became larger. When anaerobic respiration was repressed due to nitrate limitation, the biofilm formed only at the air-water interface. Strain 1073 and HU, which have higher lectin activity, formed a biofilm more effectively than other strains. Biofilm formation was repressed by the addition of N-acetyl-D-galactosamine. These results suggest that the lectin on the surface of E. corrodens might be involved in biofilm formation.