Black Molds and Melanized Yeasts Pathogenic to Humans

Abstract

A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as "phaeoid" or "dematiaceous" fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery.

Figure 1.

Pleosporalean agents. (A) Top row, Curvularia lunata; middle row, Bipolaris hawaiiensis; bottom row, Alternaria alternata. (B) Left, Alternaria cutaneous infection; right, Bipolaris chronic sinusitis.

Figure 2.

Chaetothyrialean agents of superficial mycoses. Upper row: Cyphellophora pluriseptata; lower row: left, Phialophora europaea; right, superficial infection. Scale bar, 10 μm.

Figure 3.

Chaetothyrialean agents of deep infections. Upper row: Fonsecaea pedrosoi causing chromoblastonycosis with muriform cells; middle row: Ramichloridium mackenziei, agent of cerebral phaemycosis (case shown caused by Cladaphialophora bantiana); bottom row: disseminated infection caused by Veronaea botryosa.