Q1. What is mycology and who is regarded as its father? - Mycology is the study of fungi - Derived from Gre
TOPIC 1: INTRODUCTION TO MYCOLOGY (Lecture 1) --- Q1. What is mycology and who is regarded as its father? Mycology is the study of fungi Derived from Greek word "mykes" meaning mushroom Raymond Sabouraud is the Father of Medical Mycology (published Les Teignes , 1910) --- Q2. List FOUR beneficial effects of fungi. Decomposition — nutrient and carbon recycling Source of antibiotics e.g. Penicillin from Penicillium spp. Fermentation — industrial production of alcohols and organic acids Ergot alkaloids from Claviceps purpurea — treat migraines, control bleeding, induce uterine contractions (Bonus) Model organisms for genetic studies e.g. Neurospora crassa --- Q3. List FOUR general properties of fungi. Eukaryotic — have membrane-bound organelles Cell wall made of chitin Lack chlorophyll (cannot photosynthesize) Are chemoheterotrophs — require organic compounds for carbon and energy Have ergosterols in their membranes Possess 80S ribosomes No obligate anaerobes — all require oxygen --- Q4. How are fungi classified based on sexual reproduction? Zygomycetes — produce zygospores Ascomycetes — produce ascospores inside asci Basidiomycetes — produce basidiospores on basidia Deuteromycetes (Fungi Imperfecti) — no known sexual spores --- Q5. What are dimorphic fungi? Give THREE examples. Fungi that exist in two forms depending on temperature/environment Yeast form: in host tissue and at 37°C in vitro Mould form: in natural habitat and at 25°C in vitro Examples: Histoplasma capsulatum , Blastomyces dermatitidis , Coccidioides immitis , Paracoccidioides brasiliensis --- Q6. Differentiate between septate and aseptate hyphae. Septate hyphae — have cross walls (septa) with pores; cytoplasm is continuous; damage to one compartment doesn't kill the whole strand Aseptate hyphae — no septa (non-septate); more primitive; damage kills the entire strand All moulds are septate EXCEPT Zygomycetes (e.g. Rhizopus, Mucor ) --- Q7. List FIVE types of asexual fungal spores. Conidia/Conidiospores Sporangiospores Arthrospores Chlamydospores Blastospores/Blastoconidia --- Q8. Differentiate between moulds and yeasts. Moulds — filamentous, made of hyphae; mass of hyphae = mycelium; e.g. Aspergillus Yeasts — unicellular; reproduce by budding forming blastoconidia; e.g. Cryptococcus neoformans Yeast-like — yeasts that produce pseudohyphae e.g. Candida albicans --- TOPIC 2: FUNGAL PATHOGENESIS (Lecture 2) --- Q9. List FIVE virulence factors of fungi. Adhesion to host cells via cell wall glycoproteins Capsule production — resists phagocytosis Secretion of enzymes: keratinase, elastase, collagenase Ability to resist killing by phagocytes (as in dimorphic fungi) Thermal dimorphism Secretion of mycotoxins Block cell-mediated immunity of the host --- Q10. List FIVE host defense factors against fungal infections. Physical barriers — skin and mucous membranes Fatty acid content of the skin Normal flora — keeps fungi in commensal state pH of skin and body fluids Phagocytic cells — PMNs, monocytes, macrophages Epithelial cell turnover Serum factors (chemical barriers) --- Q11. List SIX predisposing factors to fungal infections. Prolonged antibiotic therapy — disrupts normal flora HIV infection, cancer, diabetes, obesity Immunosuppressive drugs/transplants Indwelling catheters Irradiation therapy Surgical procedures Drug addiction; extremes of age --- Q12. Why is cell-mediated immunity (CMI) more important than humoral immunity in fungal infections? Fungi are intracellular pathogens — stay inside host cells CMI (T-lymphocytes, macrophages, PMNs) directly targets infected cells Antibodies have limited access to intracellular fungi However, antibodies assist through opsonization against Candida and Cryptococcus --- Q13. What are the five categories of mycoses? Superficial mycoses Cutaneous mycoses Subcutaneous mycoses Systemic (deep) mycoses Opportunistic mycoses --- TOPIC 3: FUNGAL INFECTIONS / MYCOSES (Lecture 3) --- Q14. Differentiate between superficial and cutaneous mycoses. Superficial — infects outermost layer of skin/hair/nails; no cellular immune response; cosmetic problem only; e.g. Pityriasis versicolor, Tinea nigra Cutaneous — invades keratinized tissues; evokes cellular immune response; can cause hypersensitivity reactions; caused by dermatophytes --- Q15. What is Tinea versicolor? How is it diagnosed? Fungal infection of the stratum corneum; presents as hypo/hyperpigmented skin patches Caused by Malassezia globosa / Malassezia furfur Diagnosis: KOH mount — "spaghetti and meatballs" appearance (short hyphae + budding cells) Wood's lamp — yellow fluorescence Treatment: Topical imidazole --- Q16. Name the three genera of dermatophytes and the tissues they infect. Microsporum — hair and skin; rarely nails; mostly in children Trichophyton — hair, skin AND nails; both children and adults Epidermophyton — skin and nails; rarely hair; mainly adults --- Q17. How are dermatophytes classified ecologically? Anthropophilic — infects humans only; transmitte