Research Associate Professor, Department of Oral Biology
109b Foster Hall
Buffalo, NY 14214
Biofilms are communities of bacteria attached to a surface enclosed in a matrix of extracellular polysaccharides (EPS), DNA dissolved nutrients and other biological molecules. Biofilm-associated organisms cause up to 80% of all infections. Dental plaque is a typical multispecies biofilm. The focus of our research is to define the molecular basis of biofilm formation by the periodontopathogen Aggregatibacter (Actinobacillus) actinomycetemcomitans. This organism is associated with localized aggressive periodontitis, a destructive form of periodontitis occurring primarily in adolescents, some forms of refractory periodontitis, and is a causative agent of a variety of extra-oral infections including endocarditis abscesses and septicemia. We have shown that biofilm varies quantitatively in response to environmental conditions commonly found in the oral cavity, including variable pH, nutrient availability, oxygen tension and iron. Primary biofilm determinants include fimbriae and lipopolysaccharide (LPS) involved in adhesion, along with EPS that serves in intercellular aggregation and as a protective barrier for the cells of the biofilm. We are investigating the role of small non-coding RNA in the post-transcriptional regulation of biofilm determinant genes (fimbriae, LPS and EPS) in response to iron-limited conditions. Through the use of molecular biology techniques, protein analysis, bioinformatics, and microarrays we aim to identify the pathways involved in the maintenance of biofilm by these sRNAs. We also have used the Calgary device and other microtiter systems to evaluate the antimicrobial efficacy of a new therapeutic agent against monospecies biofilms of oral microorganisms.