Although all infectious agents of humans are parasites, by convention, parasitic diseases are often defined as diseases caused by ectoparasites, parasites that live on the outside or within the skin of the host, and endoparasites, parasites that live on the…
Mycetoma (maduromycosis, Madura foot) is a neglected tropical disease that has its greatest impact on severely impoverished, remote rural communities. It is a noncontagious, localized chronic debilitating infection that affects skin, subcutaneous tissue, fascia, muscle, and bone. The foot is…
Superficial fungal infections of the skin, nails, and mucosa are mainly caused by three groups of fungi—the dermatophytes, Candida spp., and Pityrosporum spp. Non-dermatophytic molds form a fourth group that contributes a minority of such infections. Superficial fungal infections are…
Coccidioidomycosis is an infection caused by the dimorphic fungi Coccidioides immitis and Coccidioides posadasii . These fungi are endemic to the southwestern US, Mexico, Guatemala, and sporadic regions within Central and South America. Infection is caused by inhalation of highly…
Blastomyces , the etiologic agent of blastomycosis, can infect both people with healthy immune systems and those with impaired immune defenses. The Blastomyces genus consists of 7 different species, of which B. dermatitidis and B. gilchristii cause the majority of…
Description of Pathogen Pneumocystis jirovecii (formerly called P. carinii ) is an opportunistic human respiratory pathogen. Although Pneumocystis organisms share some of the common features of protozoa, molecular genetic comparisons have definitively placed Pneumocystis among the ascomycetous fungi. , Pneumocystis…
Histoplasmosis is the most common primary systemic mycosis in the Americas, affecting hundreds of thousands of people living in urban and rural areas of the Ohio and Mississippi river valleys, some mideastern states, and parts of Central and South America.…
The majority of human cryptococcal infections are caused by one of two species: Cryptococcus neoformans and Cryptococcus gattii. These species were previously separated into 3 varieties: C. neoformans var. neoformans, C. neoformans var. grubii, and C. neoformans var. gattii, which…
Sporotrichosis is a chronic subcutaneous fungal infection caused by thermally dimorphic fungal species in the Sporothrix schenckii complex . This species complex is found worldwide in soil, on decomposing vegetation, and on plant material, such as sphagnum moss, hay bales,…
Microbiology Malassezia (formerly called Pityrosporum ) is a genus of lipophilic, basidiomycetous yeasts lacking ballistospores and classified in the order Malasseziales . Its phylogenetic placement within the Ustilaginomycotina (Basidiomycota) is highly supported. Malassezia increasingly is recognized as an opportunist affecting…