| Title | D-Galactose as an autoinducer 2 inhibitor to control the biofilm formation of periodontopathogens |
|---|---|
| Author | Eun-Ju Ryu1, Jaehyun Sim1, Jun Sim2, Julian Lee2, and Bong-Kyu Choi1,3* |
| Address | 1Department of Oral Microbiology and Immunology, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea, 2Department of Bioinformatics and Life Science, Soongsil University, Seoul 06978, Republic of Korea, 3Dental Research Institute, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea |
| Bibliography | Journal of Microbiology, 54(9),632-637, 2016, |
| DOI | 10.1007/s12275-016-6345-8 |
| Key Words | quorum sensing, periodontopathogens, biofilm, AI-2 inhibitor, D-galactose |
| Abstract | Autoinducer 2 (AI-2) is a quorum sensing molecule to which bacteria respond to regulate various phenotypes, including virulence and biofilm formation. AI-2 plays an important role in the formation of a subgingival biofilm composed mostly of Gram-negative anaerobes, by which periodontitis is initiated. The aim of this study was to evaluate D-galactose as an inhibitor of AI-2 activity and thus of the biofilm formation of periodontopathogens. In a search for an AI-2 receptor of Fusobacterium nucleatum, D-galactose binding protein (Gbp, Gene ID FN1165) showed high sequence similarity with the ribose binding protein (RbsB), a known AI-2 receptor of Aggregatibacter actinomycetemcomitans. D-Galactose was evaluated for its inhibitory effect on the AI-2 activity of Vibrio harveyi BB152 and F. nucleatum, the major coaggregation bridge organism, which connects early colonizing commensals and late pathogenic colonizers in dental biofilms. The inhibitory effect of D-galactose on the biofilm formation of periodontopathogens was assessed by crystal violet staining and confocal laser scanning microscopy in the absence or presence of AI-2 and secreted molecules of F. nucleatum. D-Galactose significantly inhibited the AI-2 activity of V. harveyi and F. nucleatum. In addition, D-galactose markedly inhibited the biofilm formation of F. nucleatum, Porphyromonas gingivalis, and Tannerella forsythia induced by the AI-2 of F. nucleatum without affecting bacterial growth. Our results demonstrate that the Gbp may function as an AI-2 receptor and that galactose may be used for prevention of the biofilm formation of periodontopathogens by targeting AI-2 activity. |