"ashu sharma".

Ashu Sharma PhD

Professor, Department of Oral Biology

311A Foster Hall

Buffalo, NY 14214




The human oral cavity is a highly diverse ecosytem containing more than 500 species of bacteria, including both cultivable and non-cultivable species. It is believed that existence of a select few Gram-negative anaerobes, known as the ‘red-complex’, is responsible for periodontitis or gum-associated disease. These bacteria live as biofilms and form bacterial plaque in spaces between gums and teeth. The bacterial products cause inflammation by inducing inflammtory cytokine release from host cells. Therefore, if these bacteria are not erradicated, inflammation continues and leads to destruction of tooth supporting tissue and eventually tooth loss. My lab studies the pathogenic mechanisms of the red-complex bacteria by utilizing molecular-genetic and biochemical approaches; the bacteria of the red-complex include Porphyromonas gingivalis, Tannerella forsythia (formerly Bacteroides forsythus) and Treponema denticola (a spirochete). Our overall objectives are to gain a better understanding of how these pathogenic bacteria initiate colonization, form biofilms and initiate tissue destructive host immune responses critical for disease progression. The research focuses on identifying virulence factors these bacteria produce and host-cell receptors involved in their recognition. Identification of these virulence factors and their receptor should pave the way for developing intervention strategies, such as vaccines, against periodontal bacteria. In this regard, we have developed genetic systems whereby non-pathogenic oral streptococci (Streptococci gordonii) can be engineered to expression vaccine antigens of choice. These genetically modified streptococcal vectors can be utilized for vaccine delivery by oral route.