ALTERNATIVE CARBON UTILIZATION AS A VIRULENCE DETERMINANT FOR CANDIDA ALBICANS

Candida albicans is a polymorphic unicellular fungus that has evolved to proficiently colonize and infect mammals. A common constituent of the microbiome in the GI tract, mouth, vagina, and skin, C. albicans is also an opportunistic pathogen capable of causing a variety of mucosal infections and the life-threatening disseminated candidiasis. Systemic C. albicans infections are a serious and growing issue; the fungus is the fourth most common cause of nosocomial bloodstream infections which has a mortality rate reaching 50%. As antifungal resistance continues to rise, it is critical that I understand the molecular basis of disseminated fungal infections. The phagocytes of the immune system are especially important for preventing disseminated infection. Macrophages are employed to clear pathogens in the harsh environment of a phagosome, but C. albicans, as an adaptable opportunist, is capable of surviving macrophage attack to continue dissemination. The Lorenz Lab and other leading labs in the field have identified that C. albicans rapidly adapts to the macrophage phagosome by upregulating alternative carbon utilization processes. The utilization of three alternative carbon sources particularly contribute to C. albicans pathogenesis: carboxylic acids, amino acids, and N-acetylglucosamine. Studied individually, utilization of each carbon source appears to equally contribute to pathogenesis, although mutants defective in any one carbon utilization pathway display only modest attenuation.