My research interests are focused primarily on several different microbial products that contribute to the virulence of gram-positive bacteria, with particular emphasis on group B streptococcus (GBS) and Bacillus anthracis. GBS are a major cause of life-threatening infections of newborn babies in this country. In one project we are biochemically characterizing a hyaluronan lyase secreted by GBS and studying its role in pathogenesis. In another project we are genetically engineering a commensal organism normally present in the vagina of women, a lactobacillus, to secrete a bacteriophage lysin that will prevent vaginal colonization with group B streptococci (GBS), and thereby greatly reduce the incidence of serious neonatal GBS infections. Bacillus anthracis, the causative agent of anthrax, has already been used in bioterrorist attacks in this country and the potential for future large-scale attacks remains a serious concern. One means by which B. anthracis bacteria protect themselves from lysozyme present in blood and other bodily fluids is by deacetylating their peptidoglycan coat. We are attempting to identify the deacetylases involved in this process, with the long-term goal of developing drugs that inhibit the enzymes. This should make the bacteria susceptible to lysozyme in the blood and may provide an alternative therapeutic strategy. In another anthrax-related project we are characterizing a rhamnose-containing glycoprotein, BclA, on the surface of anthrax spores. Mutant spores that are unable to make rhamnose are much less virulent in a mouse model of anthrax.
David G. Pritchard (b. 1945), Professor of Biochemistry and Molecular Genetics, received his Ph.D. degree in biochemistry from the University of California at Los Angeles in 1975. He then spent 3 years at the City of Hope Research Institute in Duarte, California, studying the human tumor marker carcinoembryonic antigen. After coming to Birmingham in 1977, Dr. Pritchard began studying the protein and polysaccharide antigens of group B streptococci and their roles in pathogenesis. He has recently become interested in characterizing the glycoproteins on the surface of B. anthracis spores.