A case of Malassezia furfur infection in a newborn

Abstract

We report a clinicopathologically confirmed case of disseminated Malassezia furfur infection in a neonate with severe surgical pathology and a fatal outcome. Early isolation of M. furfur from non-sterile sites was underestimated, whereas subsequent cultural and histopathological examination of autopsy material confirmed an invasive infection. Yeast cells were detected within and along vessel walls, accompanied by vasculitis, septic “target-like” thrombi, and ischemic and necrotic changes in the lungs, liver, kidneys and heart. Fungal growth was obtained on modified Leeming–Notman agar, and species identification was confirmed by MALDI-TOF MS. Antifungal susceptibility testing revealed high minimal inhibitory concentrations for echinocandins and fluconazole, while amphotericin B, itraconazole, and posaconazole retained activity, which correlated with the lack of clinical response to micafungin and fluconazole. This case emphasizes the potential of M. furfur to cause true invasive disease in neonates and highlights the need for early recognition of Malassezia isolates in high-risk patients. Accurate identification using lipid-supplemented media or molecular techniques and appropriate antifungal selection based on species-specific susceptibility are crucial for optimal management.