RT Book, Section A1 Ryan, Kenneth J. SR Print(0) ID 1185634759 T1 The Opportunistic Fungi: Candida, Aspergillus, the zygomycetes, and Pneumocystis T2 Sherris & Ryan's Medical Microbiology, 8th Edition YR 2022 FD 2022 PB McGraw-Hill Education PP New York, NY SN 9781260464283 LK accessmedicine.mhmedical.com/content.aspx?aid=1185634759 RD 2024/03/28 AB The “opportunistic fungi” are usually found as members of the resident human microbiota or on decaying matter in the environment. With the breakdown of host defenses, they can cause infections ranging from skin/mucous membrane involvement to life-threatening, systemic disease. The most common opportunistic infections are caused by two species: the yeast Candida albicans, a common inhabitant of the gastrointestinal and genital microbiota; and the mold Aspergillus fumigatus which is widespread in the environment. Pneumocystis, a frequent cause of pneumonia in AIDS patients, is an unusual fungus that used to be considered a parasite on morphologic grounds. However, it too is a frequent colonizer of the human respiratory tract. The diseases caused by these opportunistic fungi are summarized in Table 46–1.