Melanized Fungi in Human Disease

Abstract

SUMMARY Melanized or dematiaceous fungi are associated with a wide variety of infectious syndromes. Many are soil organisms and are generally distributed worldwide, though certain species appear to have restricted geographic ranges. Though they are uncommon causes of disease, melanized fungi have been increasingly recognized as important pathogens, with most reports occurring in the past 20 years. The spectrum of diseases with which they are associated has also broadened and includes allergic disease, superficial and deep local infections, pneumonia, brain abscess, and disseminated infection. For some infections in immunocompetent individuals, such as allergic fungal sinusitis and brain abscess, they are among the most common etiologic fungi. Melanin is a likely virulence factor for these fungi. Diagnosis relies on careful microscopic and pathological examination, as well as clinical assessment of the patient, as these fungi are often considered contaminants. Therapy varies depending upon the clinical syndrome. Local infection may be cured with excision alone, while systemic disease is often refractory to therapy. Triazoles such as voriconazole, posaconazole, and itraconazole have the most consistent in vitro activity. Further studies are needed to better understand the pathogenesis and optimal treatment of these uncommon infections.

Cladophialophora bantiana as an Emerging Pathogen in Animals: Case Report of Equine Endometritis and Review of the Literature

“…It has been discovered from soil in Panama (15); from tree bark (16) and a brick wall of a warehouse (17) in Virginia, USA; and recently from the hot tub water of a retirement community in the United States (18). Human infections have been observed worldwide (8), but the distribution of cases indicates that C. bantiana has a preference for warmer climates with high average humidity (9). The same conclusion can be drawn from the geographical distribution of animal infections (Table 1).…”

“…Ten different Cladophialophora species are known to cause infections in humans. Of these, C. bantiana is a well-known causative agent of cerebral phaeohyphomycosis, which is often a fatal condition (8,10). Many such cases have been diagnosed in people without apparent immune deficiency (8), although there may be underlying genetic susceptibilities associated, for instance, with mutations in the CARD9 gene with subsequent decreased cytokine production by innate immune cells (7).…”

“…Many such cases have been diagnosed in people without apparent immune deficiency (8), although there may be underlying genetic susceptibilities associated, for instance, with mutations in the CARD9 gene with subsequent decreased cytokine production by innate immune cells (7). The prognosis of cerebral phaeohyphomycosis is poor, regardless of aggressive surgical and medical treatment (8). C. bantiana has also been involved in (sub)cutaneous infections (11)(12)(13) and in a joint infection (14) in humans.…”

“…From a clinical perspective, three groups can be distinguished within the order: (i) pathogens, which have the advantage of using vertebrate vectors and which need specialized methods to be isolated from the environment; (ii) agents of chromoblastomycosis, which have a distinct pathogenic phase in mammalian tissue; and (iii) saprobes, which cause infections only by coincidence (7). The melanized fungi are unique in being capable of causing a plethora of diseases in mammals, such as phaeohyphomycosis, eumycetoma, and chromoblastomycosis (8). Among others, melanin, chitin, thermotolerance, and the assimilation of aromatic hydrocarbons are considered to play a role in pathogenesis (9).…”

A review on research advances, issues, and perspectives of morels

“…Development of Genealogical Concordance Phylogenetic Species Recognition (GCPSR) (Taylor et al 2000) provided a consensus criterion for resolving species relationships among fungi, including those of morels (Dettman et al 2003; Revankar and Sutton 2010; Taşkın et al 2010, 2012; O’Donnell et al 2011; Du et al 2012a; Zeng et al 2013; Elliott et al 2014; Pildain et al 2014; Voitk et al 2014). …”