01 Fungus Intro Duncan Flashcards
What are viruses that attack bacteria called?
Bacteriophages
What are the characteristics of Archaea?
Bacteria-like in some respects (size, lack of nuclear membrane); Eukaryote-like in others (DNA and protein structure)
What is the Fungal Cell Wall primarily made out of?
Chitin. Hence, insensitive to inhibitors of peptidoglycan synthesis (i.e. B-Lactams)
What is an important part of the Fungal Cell Membrane?
Ergosterol. Imparts sensitivity to inhibitors of ergosterol synthesis, activity (e.g. Amphotericin, Azoles, etc.)
What are the different Fungal Growth Types?
Yeasts (single cells). Molds - mat of filaments (Mycelium, Hyphae - septate and nonseptate). Dimorphic (Shifts d/t growth situation; e.g. temperature)
What is the difference between septate and nonseptate in fungal growth types?
When looking at septate fungus, you can clearly see the different cells connected together. In Nonseptate, cell membranes between cells are dissolved
How does Fungal Reproduction occur?
Asexual (budding, conidia). Sexual (mating)
What is Fungal metabolism like?
Cannot photosynthesize; therefore must obtain carbon food from the environment
What is Chitin made from?
A long change of N-Acetylglucosamine
If the Fungal cell wall and cell membrane, what ratio varies with species?
Ratio of Chitin to branched B-Glucan
What are some Fungal Toxins and Mycotoxicoses?
Amantin (Amanita mushrooms). Ergot Alkaloids (Grain-infecting fungi (Claviceps), neurotoxicity). Aflatoxin (Aspergillus flavus growth on soiled grains, hepatotoxicity/hepatic cancer)
What is used for Fungal Diagnosis?
Microscopic examination (KOH, special stains). Culture (Sabouraud’s agar (no bacterial growth)). DNA-based tests. Serologic tests
What are the worst Fungal Diseases?
Systemic infections. Opportunistic infections
What are the causative fungi for opportunistic infections?
Cryptococcus. Candida. Aspergillus. Mucor, Rhizopus
What are the causative fungi for Systemic infections?
Coccidioides. Histoplasma. Blastomyces. Paracoccidioides
What is Dermatophytoses?
Cutaneous infections caused by Fungi
What types of infections fall under Dermatophytoses?
Athlete’s foot (tinea pedis), jock itch (tinea cruris). Ringworm. Dermatophytid: antibody response to circulation fungal antigens - skin lesions
Which Fungi are often associated with Dermatophytoses?
Epidermophyton. Microsporum. Trichophyton
What are the general characteristics of Subcutaneous infections caused by Fungi?
Slow spreading from site of injury. Rarely becomes systemic, or serious. Granulomatous response (macrophages). Lymphatic involvement
What are the different Subcutaneous infections caused by Fungi?
Sporotrichosis. Chromomycosis (lesser importance). Mycetoma (lesser importance)
What is Sporotrichosis?
Type of SubQ Infection. Dimorphic Sporothrix. Spread from vegetation, e.g. thorn pricks
What is Chromomycosis?
Type of SubQ Infection. Caused from several soil fungi (Fonsecaea, Phialophora, Cladosporium). Spread when cuts are exposed to soil, e.g. gardening
What is Mycetoma?
Type of SubQ Infection. Caused from several soil fungi (Petriellidium, Madurella). Spread from soil
What are some general characteristics of Systemic Infections caused by Fungi?
Inhalation into lungs. Soil resident mycelial form. Airborne spores inhaled, differentiate into yeasts into the lungs. Assymptomatic, self-limiting (except in immunocompromised: HIV, drugs). Disseminated, serious. Non-contagious
