My research interests include microbial pathogenesis and fungal diseases. Our lab studies stress adaptation in species of Cryptococcus, a yeast that can cause life-threatening disease in humans. Cryptococcus are environmental fungi inhaled into the lungs as spores or yeast. A pulmonary infection that takes root may spread to the brain, resulting in a lethal cryptococcal meningitis. Infections primarily affect individuals with HIV/AIDS and others with weakened or suppressed immune systems.
The goal of our research is to understand how environmental fungi adapt in response to stress to survive the environment-to-host transition, develop drug resistance and cause persistent human disease. We employ a variety of tools (phenotypic assays, whole-genome sequencing, quantitative PCR, microscopy, etc.) to characterize the genetic and cellular changes that occur in Cryptococcus in response to environmental cues such as heat stress, changes in pH and nutrient availability.
We recently discovered that heat stress increases drug resistance and the overall mutation rate in species of Cryptococcus. Specifically, we found that the movement of some mobile genetic elements, called transposons or ‘jumping genes,’ is stimulated by heat stress at human body temperature. These movements result in genetic mutations that can alter gene function and/or expression and lead to adaptation. We are currently investigating the impact of these genetic changes on virulence and disease persistence.