Description of Research
My research program focuses on aspects of bacterial physiology and cell communication that contribute to biofilm development of pathogenic Gram-positive bacteria. Specific research projects currently under investigation include:
1. Determining the contributions of endogenous nitric oxide (NO) to biofilm, physiology and cell-signaling in Staphylococcus aureus. NO is a free-radical gas that has been well-characterized as a signaling molecule in eukaryotes, and more recently, a role for this versatile molecule in regulating bacterial physiology and biofilm development has also been recognized. Our research is focused on dissecting the pathways of endogenous NO production and consumption in Staphylococcus aureus (MSSA and MRSA), a notorious pathogen that causes a wide variety of serious infections in mammals. This work also seeks to identify the upstream regulators and downstream cellular targets of endogenously-produced NO, and to determine how these processes relate to biofilm development.
2. Characterizing the role and regulation of cell death in Streptococcus mutans biofilms. The cid and lrg operons encode membrane proteins that have been shown to be involved in cell death and lysis regulation in several bacteria. Our research focuses on the Cid/Lrg system of Streptococcus mutans, the primary causative agent of dental caries. There appear to be distinct differences in the organization and regulation of S. mutans cid and lrg compared to what is known in other organisms, and some of these genes affect S. mutans virulence traits such as oxidative stress resistance, competence, and biofilm formation. A better understanding of how cid and lrg specificallycontribute to these virulence phenotypes may allow the development of new anti-caries strategies. This research is conducted in collaboration with Dr. Sang-Joon Ahn, Research Assistant Professor, Dept. Oral Biology, UF.
3. Investigating microgravity effects on S. mutans physiology, gene expression, and biofilm development. The health of astronauts during space flight is of paramount concern, as various detrimental health effects resulting from exposure to microgravity conditions have been documented. In fact, simulated microgravity exposure has been shown by others to cause increased mandibular and alveolar bone loss and decreased saliva flow, two host factors that could predispose astronauts to caries and/or periodontal disease. Although the host response to microgravity has been well-studied, the response of cariogenic bacteria such as S. mutans has not been rigorously assessed. Therefore we are studying the response of S. mutans physiology, biofilm formation and global gene expression to simulated microgravity conditions.
- Teaching Interests
- MCB 4203 - Bacterial and Viral Pathogens
- MCB 4034L - Advanced Microbiology Lab
- Undergraduate Research