Identifying Genes Involved in Anti-fungal Drug Resistance

We are interested in understanding anti-fungal drug resistance mechanisms in the fungal pathogen, Cryptococcus neoformans. C. neoformans infection can cause pneumonia in humans and in rare cases, Cryptococcal meningitis in immunocompromised individuals. The commonly used anti-fungal drug currently used against Cryptococcal infection is the azole drug, fluconazole. Based on RNA-sequencing experiment to determine genes that are upregulated in C. neoformans in the presence of fluconazole, we tested 10 mutant strains, which were inhibited in multiple cellular pathways, of Cryptococcus, for growth in presence of fluconazole. We conducted preliminary assays to determine the Minimal Inhibitory Concentration (MIC) of each of the strains in comparison to wild-type, growth assays to detect growth of each of the mutant strains in the presence of fluconazole, and disc assays to determine the zone of inhibition of each mutant in the presence of fluconazole. We concluded that the sterol regulatory element( SRE1), is essential for regulating the sensitivity to fluconazole. This was an expected result as the mode of action of fluconazole is to inhibit the biosynthesis of the sterol, ergosterol. Future experiments will test the role of sterol regulatory element in regulating fluconazole sensitivity in the host, during Cryptococcal infections.