8 topics with a brief review: definitions, key facts, and classroom questions.
Opportunistic mycoses are diseases of suppressed immunity. A healthy organism easily handles their causative agents, but for immunocompromised patients (with HIV infection, oncology, after transplantation) they become a fatal threat. In this section, we analyze the fungi that take advantage of the macroorganism's weakness.
Collected here are the main opportunists: the ubiquitous yeast Candida, molds (Aspergillus, Penicillium, Fusarium), aggressive agents of zygomycosis, as well as atypical pathogens — Pneumocystis jirovecii and intracellular microsporidian parasites.
In exams and colloquia, instructors most often ask about the pathogenicity factors of Candida albicans, the morphology of aspergilli (the famous "vesicle/phialide structure" / "watering can"), and laboratory diagnostic methods for Pneumocystis pneumonia. Pay special attention to the morphology of fungi in affected tissues and on nutrient media — this is the key to a successful answer and a correct diagnosis in the future.
What is the main difference between opportunistic mycoses and classic mycoses?
They are caused by opportunistic flora that is normally safe for humans and develop exclusively against the background of suppressed immunity or disturbed microbiocenosis.
What are the main distinguishing features of C. albicans during identification?
C. albicans is characterized by two key features: elongation of budding cells to form "germ tubes" in blood serum and the formation of large, thick-walled chlamydospores when cultivated on rice agar.
What is the main morphological difference between the mycelium of zygomycetes and other fungi?
Their key feature is the absence of septa (cross-walls) in the mycelium. The branching hyphae look like single hollow tubes with multiple nuclei.
Why are microsporidia classified under the Fungi kingdom?
For a long time, they were mistakenly classified as primitive protozoa. However, modern research has shown that in their biology they belong to lower fungi—phycomycetes (phylum Zygomycota).
What is "ragpicker's disease" or "scavenger's disease"?
This is occupational aspergillosis, which occurs in people with regular contact and inhalation of dust from old moldy paper, rags, or organic debris.
What is the main mechanism of infection with penicilliosis?
The disease is transmitted via an airborne route by inhaling dust containing spores and fungal mycelial elements from soil or vegetable stores.
Study the full topic in the «Microbiology» course
This is a summary. The course covers everything tested in classes and exams.
4,383 pages of study guides across all topics
Assignments and quizzes after every topic — just like in a colloquium