Investigating the Invertebrate Response to Cryptococcus neoformans, a Fungal Pathogen

Abstract

Cyrptococcus neoformans (Cn) is a pathogen that kills more than 250,000 people each year. Several organisms are used as models to investigate pathogenesis of Cryptococcus such as larvae of the wax moth, Galleria mellonella. These larvae have phagocytic haemocytes which engulf and kill microbes similarly to mammalian neutrophils. To investigate aspects of the pathogen, a strain of Cn (H99W) was serially passaged in Galleria larvae 15 times to create an evolved strain, P15. Based on results of genomic analysis and mammalian infections of P15 and H99W, a peroxide induction study with Galleria was conducted to compare the immune response of the parent and evolved strain. To further analyze the characteristics of the evolved strain, a growth assay was conducted to determine changes in growth between P15 and H99W. The results showed a subdued immune response and faster growth in hemolymph by P15 compared to H99W.