Metabolic Profiling of Candida auris, a Newly-Emerging Multi-Drug Resistant Candida Species, by GC-MS

Abstract

Candida auris, a newly-emerging Candida species, is a serious global health threat due to its multi-drug resistant pattern, difficulty to diagnose, and the high mortality associated with its invasive and bloodstream infections. Unlike C. albicans, and C. dubliniensis which can form true hyphae, C. auris grows as yeast or pseudohyphae and is capable of developing biofilms. The reasons for the inability of C. auris to form true hyphae are currently unknown. Metabolites secreted by microorganisms, including Candida, are known as important factors in controlling morphogenesis and pathogenesis. Metabolic profiling of C. auris and C. albicans cultures was performed using gas chromatography⁻mass spectrometry (GC⁻MS). Compared to C. albicans, C. auris secreted several hyphae-inhibiting metabolites, including phenylethyl, benzyl and isoamyl alcohols. Furthermore, a biofilm-forming metabolite—tyrosol—was identified. On the other hand, several other biomarkers identified from C. auris but not from C. albicans cultures may be produced by the organism to overcome the host immune system or control fungal adaptations, and hence ease its invasion and infections. The results from this study are considered as the first identification of C. auris metabolic activities as a step forward to understand its virulence mechanisms.

Keywords

• Candida auris
• metabolic profiling
• GC-MS
• morphogenesis
• hyphae
• yeast