Mycology Sporothrix schenckii sensu lato (meaning in the broadest sense) is a dimorphic fungus that exists in a hyphal form in vitro at temperatures less than 37°C. Colonies are initially white but gradually become brown to black due to the…
The disappearance of the class Zygomycetes from current taxonomy has made the term zygomycosis obsolete. The term zygomycosis encompassed both mucormycosis and entomophthoramycosis. These two infections are so different that no new name has been proposed to include both infections.…
Revised August 7, 2021 Invasive aspergillosis (IA) remains a major cause of morbidity and mortality in the immunosuppressed population. This infection is caused by Aspergillus , a hyaline mold, and is responsible for a variety of noninvasive or semiinvasive conditions.…
Revised April 26, 2022 Written descriptions of oral lesions that were probably thrush date to the time of Hippocrates and Galen. Langenbeck, in 1839, found fungi in oral lesions of a patient. In 1861, Zenker described the first well-documented case…
The advent of the human immunodeficiency virus epidemic and the ever-increasing use of immunosuppressive drugs has dramatically increased the incidence of deep mycoses and substantially broadened the range of fungi causing potentially lethal disease. Clinicians caring for highly immunosuppressed patients…
Actinomycosis is an indolent, slowly progressive infection caused by anaerobic or microaerophilic bacteria, primarily from the genus Actinomyces, that normally colonize the mouth, colon, and vagina. Disruption of mucosa may lead to infection of virtually any site. When the organisms…
Nocardia is a genus of aerobic actinomycetes responsible for localized or disseminated infections in animals and humans. The genus is named after Edmond Nocard, who in 1888 described the isolation of an aerobic actinomycete from cattle with bovine farcy. The…
Revised March 30, 2021 Overview The recent advances in mycobacterial culture techniques and the increasing utility of modern molecular techniques for identification of previously unidentified organisms have produced a major resurgence of interest in disease caused by the nontuberculous mycobacteria…
Mycobacterium avium complex (MAC) is the most common of all the nontuberculous mycobacteria (NTM) to cause human infection and pulmonary infection. MAC contains genetically diverse strains with different reservoirs and pathogenicity for humans. The three most common are M. avium,…
Leprosy, or Hansen disease, is a curable infectious disease caused by Mycobacterium leprae. Widespread implementation of multidrug antibiotic therapy for leprosy in the 1980s dramatically decreased the burden of leprosy worldwide. There is no indication for physical or social isolation…