The age of a pathogen affects its virulence, according to Bettina C. Fries, M.D., and her Ph.D. student Tejas Bouklas. They reported their novel finding last August in mBio.
The researchers were studying the fungus Cryptococcus neoformans, which causes chronic meningoencephalitis in HIV patients and can persist despite antifungal therapy. They found that older C. neoformans cells accumulated in infected rats and humans because these cells were more resistant than younger cells to antifungal drugs.
In conjunction with these findings, Aviv Bergman, Ph.D., and his lab members mathematically modeled the aging of C. neoformans inside a host and showed that the presence of older cells was due to selective pressures inside the host. These findings suggest that a pathogen’s age may influence its virulence and could lead to better therapies for chronic fungal infections. Dr. Fries is a professor of medicine (infectious diseases) and of microbiology & immunology at Einstein and director of medical services and associate director of the internal medicine program at Montefiore. Dr. Bergman is professor and chair of systems & computational biology and a professor of pathology, as well as a professor in the Dominick P. Purpura Department of Neuroscience; he holds the Harold and Muriel Block Chair in Systems & Computational Biology.