Term
| Treatment for superficial mycoses |
|
Definition
* Polyenes, azoles in creams
* Also griseofulvin, allylamines |
|
|
Term
| Treatment for systemic mycoses |
|
Definition
* Polyenes azoles
* In combination with 5-flucytosine |
|
|
Term
| What type of local therapy can be used for vulvovaginal candidiasis? |
|
Definition
|
|
Term
| Oral therapy is used for what type of mycoses |
|
Definition
| Skin and nail infections for up to one year |
|
|
Term
| Systemic mycoses are treated via what route? |
|
Definition
|
|
Term
| Major chemical feature of polyenes |
|
Definition
| They are amphipathic and therefore capable of inserting into membranes |
|
|
Term
| What do polyenes primarily bind to? |
|
Definition
| Sterols with poor specificity, mainly ergosterol |
|
|
Term
| Polyene used for systemic fungal infections |
|
Definition
|
|
Term
| Why are the polyenes toxic? |
|
Definition
| Cross-reaction with cholesterol in host cell |
|
|
Term
| How are the polyenes administered |
|
Definition
| Chiefly IV because of poor absorption; can be given p.o. to treat GI infections |
|
|
Term
| Polyene used for topical treatment of superficial dermatophytoses, including oral and intestinal Candida infections |
|
Definition
|
|
Term
| Adverse reactions of systemic polyene administration |
|
Definition
* Fever
* Nephrotoxicity
* Hypokalemia (cardiotoxicity) |
|
|
Term
| Less toxic form of polyenes |
|
Definition
| Lipid formulations of amphotericin B |
|
|
Term
| How polyenes disrupt fungal membranes |
|
Definition
| Multiple polyenes bind, form pore and cause lysis |
|
|
Term
|
Definition
|
|
Term
| T/F: Most antifungal therapy uses amphipathic drugs |
|
Definition
| True (polyenes are amphipathic) |
|
|
Term
| Are most antifungals fungocidal or -static? |
|
Definition
|
|
Term
| Mechanism of action of azoles |
|
Definition
| Inhibit synthesis of ergosterol |
|
|
Term
| Clinical uses of ketoconazole |
|
Definition
* Systemic and mucocutaneous infections
* Prevention of Candida infection in immunocompromised |
|
|
Term
| Is ketoconazole good against cryptococcal meningitis? |
|
Definition
| No because it doesn't get into CNS well |
|
|
Term
| Adverse reactions of ketoconazole |
|
Definition
* GI distress
* Hepatotoxicity
* Steroid synthesis inhibition |
|
|
Term
| Why fluconazole is less toxic to humans |
|
Definition
| Less active against mammalian cytochrome P450 |
|
|
Term
| Relative antifungal spectra of ketoconazole, fluconazole, and itraconazole |
|
Definition
| Itraconazole > fluconazole > ketoconazole |
|
|
Term
|
Definition
* Many CYP interactions
* Hepatotoxicity |
|
|
Term
| Topically tend to be imidazole or triazoles? |
|
Definition
|
|
Term
| Biggest concern of azole administration |
|
Definition
| Resistance, which is why 3rd generation of azoles were created |
|
|
Term
|
Definition
|
|
Term
| Drugs that inhibit squalene epoxidase |
|
Definition
| Allylamines (eg, terbinafine) |
|
|
Term
| Consequences of squalene epoxidase inhibition |
|
Definition
* Buildup of intracellular squaline (fungotoxic)
* Decreased ergosterol synthesis |
|
|
Term
| Adverse reactions to terbinafine |
|
Definition
* GI distress
* Taste disturbances
* Hepatotoxicity |
|
|
Term
| Therapeutic niche for terbinafine |
|
Definition
* Tinea cruris
* Tinea corporis |
|
|
Term
| General class of antifungals associated with cell wall synthesis inhibition |
|
Definition
|
|
Term
| Antifungal that inhibits beta-(1,3)-glucan synthase |
|
Definition
|
|
Term
| Fungal targets of caspofungin |
|
Definition
|
|
Term
| Adverse reactions of caspofungin |
|
Definition
* Nausea
* Vomiting
* Fever
* Phlebitis |
|
|
Term
| Inhibitor of beta-(1,3)-glucan synthase |
|
Definition
|
|
Term
| Mechanism of action of flucytosine and fluorouracil |
|
Definition
| Inhibition of DNA and RNA synthesis |
|
|
Term
| Caspofungin inhibits a beta-(1,3)-glucan synthase that is active during what stage of fungal growth? |
|
Definition
| During formation of bud (thus very effective against yeast cells while not great against filamentous except for Aspergillus) |
|
|
Term
| Why caspofungin might be less effective against hyphal organisms than budding organisms |
|
Definition
* Hyphae generally more stable
* Don't form cell wall septa |
|
|
Term
| Are flucytosine and fluorouracil effective if administered alone? |
|
Definition
| No, because of side effects |
|
|
Term
| Fluorouracil is an inhibitor of what stages of metabolism? |
|
Definition
|
|
Term
| Active form of 5-flucytosine |
|
Definition
|
|
Term
| Antifungals that interacts with polymerized microtubules and keratin |
|
Definition
|
|
Term
| Mechanism of mitosis inhibition of griseofulvin |
|
Definition
| Disrupt mitotic spindle by binding polymerized microtubules |
|
|
Term
| Side effects of griseoflvin |
|
Definition
* Transient headache
* Mental confusion, fatigue, visual impairment
* GI distress |
|
|
Term
| Niche uses of griseofulvin |
|
Definition
Superficial dermatophytes
* Trichophyton
* Epidermophyton
* Microsporum |
|
|
Term
|
Definition
* Allergy
* Toxins
* Destroy tissue (mycosis) |
|
|
Term
| Morphology of most pathogenic fungi |
|
Definition
|
|
Term
| How do fungi get their nutrients? |
|
Definition
| Feed on dead or decaying tissue (hence saprophytic) |
|
|
Term
| Three locations of fungal infections |
|
Definition
* Superficial
* Subcutaneous
* Systemic |
|
|
Term
| Fungal species associated with lung and meningeal infections |
|
Definition
|
|
Term
| Fungal species associated with oral and GI tract infections |
|
Definition
|
|
Term
| Fungal species associated with subcutaneous infection of the arms and hands |
|
Definition
|
|
Term
| Fungal species that causes Athlete's foot (superficial infection of skin and between toes) |
|
Definition
* Epidermophyton
* Trichophyton |
|
|
Term
|
Definition
| Can be haploid or diploid |
|
|
Term
| Fungal cell wall components |
|
Definition
* Chitin
* Glycoproteins (mannans, glucans) |
|
|
Term
| Monomeric subunit of chitin |
|
Definition
|
|
Term
| Are fungi autotrophs or heterotrophs? |
|
Definition
| Heterotrophs, specifically saprophytes (live on dead organic matter) |
|
|
Term
| How do fungi obtain nutrients? |
|
Definition
| Secrete degradative enzymes (proteases, lipases, glucanases, etc.) into immediate invironment |
|
|
Term
|
Definition
| Moist environment (soil, water) containing decaying organic matter |
|
|
Term
| Morphological transition required for virulence in C. albicans |
|
Definition
| Budded-to-hyphal transtion |
|
|
Term
| Fungal morphology associated with filamentous growth of cells with well defined borders |
|
Definition
|
|
Term
| Fungal morphology associated with filamentous growth of cells whose borders are not easily discerned |
|
Definition
|
|
Term
| Do both fungi and bacteria have sterols in their cell membranes? |
|
Definition
| No, only fungi (and other eukaryotes) have sterols. (Mycoplasma is the one bacterial species that violates this rule; it does have sterols in its cell membrane.) |
|
|
Term
| Do fungi have generally have endo- and exotoxins? |
|
Definition
|
|
Term
| Saccharomyces cerevisiae and Neurospora crassa exist vegetatively in a haploid or diploid state? |
|
Definition
|
|
Term
| Are ascospores similar to bacterial endospores? |
|
Definition
| No; ascospores are sexual spores intended for fungal reproduction, while endospores are intracellular spores that provide protection. |
|
|
Term
| Another name for meiosis in fungi |
|
Definition
|
|
Term
| How does Saccharomyces cerevisiae generate zygotes? |
|
Definition
| Haploid ascospores of the a and alpha variety join together |
|
|
Term
| Primary method by which filamentous fungi reproduce and spread within the environment |
|
Definition
|
|
Term
| Structure responsible for fungal color as seen on food |
|
Definition
|
|
Term
| How are conidia and ascospores developed? |
|
Definition
* Conidia: asexually (mitosis of a haploid cell)
* Ascospores: sexually (meiosis of a diploid cell) |
|
|
Term
| What type of spore is often used to identify fungal species? |
|
Definition
|
|
Term
| Species of what two fungal genera cannot be discerned under the microscope? |
|
Definition
|
|
Term
| Non-culture methods using antigens are useful for differentiating between species of what two fungal genera? |
|
Definition
* Cryptococcus
* Histoplasma |
|
|
Term
| Dye used to stain conidia |
|
Definition
|
|
Term
| How is a 10% KOH solution useful for identifying fungal infections? |
|
Definition
| Solution dissolves mammalian tissue to isolate fungal cells |
|
|
Term
| Stains used histologically to stain fungi pink or black |
|
Definition
* Pink: Periodic acid Schiff (PAS)
* Gomori's methenamine silver (GMS) |
|
|
Term
| Spherules visible on microscopy is suggestive of a fungal infection by what organism? |
|
Definition
|
|
Term
| Typical immune response to fungi |
|
Definition
| Cell-mediated (humoral response isn't useful) |
|
|
Term
| Why Candida albicans is so frequently seen in nosocomial infections |
|
Definition
| It's a commensal organism |
|
|
Term
| Between 1980 and 1990, the frequency of what type of fungal infection increased the most? |
|
Definition
| Bloodstream infections (400%) |
|
|
Term
| Fungi capable of avoiding clearance in the lungs |
|
Definition
* Aspergillus
* Cryptococcus
* Histoplasma |
|
|
Term
| C. albicans must grow in what form in order to penetrate epithelium? |
|
Definition
|
|
Term
| Does auxotrophy make an organism more, or less virulent? |
|
Definition
|
|
Term
| Fungal goals achieved by fungus-mediated host tissue necrosis |
|
Definition
* Overcomes tissue barriers
* Provides nutrients for fungus |
|
|
Term
| Deletion of what protease genes can cause attenuated virulence in C. albicans? |
|
Definition
|
|
Term
| Two mechanisms by which C. albicans can cross epithelial barriers? |
|
Definition
* Induced phagocytosis (like Salmonella)
* Hyphal penetration |
|
|
Term
| What fungal organisms require a budded-hyphal transition for virulence? |
|
Definition
|
|
Term
| What fungal species can grow as yeast or hyphae? |
|
Definition
* Blastomyces
* Candida
* Histoplasma |
|
|
Term
| Once C. albicans reaches the blood, what form does it assume? |
|
Definition
| Budded form (following a hyphal-to-budded transition) |
|
|
Term
|
Definition
| Multinucleate cells containing hundreds of Coccidioides endospores |
|
|
Term
| During what phase of growth do Coccidioides form spherules? |
|
Definition
| Saprophytic phase (a form of hyphal growth) |
|
|
Term
| Fungi that secrete phospholipases targeting the host cell membrane |
|
Definition
* Aspergillus
* Candida
* Cryptococcus |
|
|
Term
| Unique characteristics of Candida and Histoplasma required for virulence |
|
Definition
| Budded-to-hyphal transition |
|
|
Term
| Fungi that can degrade cell membranes with phospholipases |
|
Definition
* Aspergillus
* Candida
* Cryptococcus |
|
|
