--- MEDICAL MYCOLOGY — EXAM NOTES (MBMM3334) --- SECTION 1: INTRODUCTION & GENERAL PROPERTIES Mycology = study of fungi ( mykes = mushroom in Greek). Fungi inha
--- MEDICAL MYCOLOGY — EXAM NOTES (MBMM3334) --- SECTION 1: INTRODUCTION & GENERAL PROPERTIES Mycology = study of fungi ( mykes = mushroom in Greek). Fungi inhabit almost every environmental niche. Historical milestones: - 1835 — Bassi: first documented animal fungal infection - 1910 — Sabouraud published Les Teignes → Father of Medical Mycology - --- Beneficial Effects- Decomposition → nutrient/carbon recycling - Fermentation → alcohols, fats, organic acids (citric, oxalic, gluconic) - Antibiotics → Penicillin from Penicillium spp. - Model organisms → Neurospora crassa (genetics); S. cerevisiae (recombinant DNA, Hep B vaccine) - Food → mushrooms, vitamins, cofactors from yeasts - Cheese flavouring → Penicillium spp. - Ergot alkaloids ( Claviceps purpurea ) → uterine contractions, bleeding control, migraine treatment - Biocontrol → Leptolegnia caudata & Aphanomyces laevis trap mosquito larvae (malaria control) - Harmful Effects- Destroy lumber, paper, cloth - Cause human/animal diseases and allergies - Produce mycotoxins and poisonous mushrooms - Cause crop diseases (e.g. potato blight) - Spoil stored agricultural produce - --- General Properties- Eukaryotic — membrane-bound organelles - Rigid cell wall made of chitin (not cellulose like plants) - No chlorophyll — cannot photosynthesize - Chemoheterotrophs — need organic compounds for carbon AND energy - Ergosterols in membranes — regulate permeability/fluidity → KEY antifungal drug target - 80S ribosomes (eukaryotic; bacteria have 70S) - Nutrients obtained as saprophytes (dead matter) or parasites (living matter) - Need water and oxygen → no obligate anaerobes - Reproduce by spores (sexually and/or asexually) - Grow by budding (reproductive) or hyphal tip elongation (non-reproductive) - Store food as lipids and glycogen - Growth and Nutrition- Optimal pH: ~5.0 (acidic) - Most grow at 25°C ; pathogens grow at 37°C - Grow in high sugar concentrations (inhibits competing organisms) - Use glucose and maltose for energy; store glycogen - Mostly aerobic; fermentation yeasts can grow in low oxygen - ---