Fungi + Protozoa Intro Flashcards
Mycology Def
Study of fungi
Fungal Cell Outline
Eukaryotic. Heterotrophic; saprophytic (food from dying /dead matter) and parasitic (living matter). Aerobic, thermotoletant (grow at most temps but optimal 28 degrees C).
Examples of fungi in food industry
Aspergillus niger - produces citric acid. Saccharomyces - baking, brewing and a vitamin B source
Examples of fungi in medicine
Penicillin Notatum - antibiotic. Cyclosporine A - prevent organ transplant rejection
Example of harmful fungi
Aspergillus Fumigatus - fungi in soil can contaminated air, water, food and cloth through spores
Growing fungi on an agar plate
Agar contains antibiotics and a pH of 5.6 (fungi are more acidic resistant then bacteria). Can be observed under a microscope with no staining (may naturally produce pigments on plate) or by gram staining (different from bacterial as fungal cells are bigger)
2 forms of fungal cells
Yeast (single cell) and mycelia (long threads of cells divided by septa)
Components of yeast cell
Nucleus, cell wall, plasma membrane, centrioles, lysosomes, endoplasmic reticulum, golgi apparatus, ribosomes and mitochondria
Components of mycelia
Septa, vacuoles, cytoplasm, endoplasmic reticulum, nucleus, mitochondria, plasmalemma (membrane equivalent) and vesicles (at growing tip)
Fungal Nucleus
Chromosomes contained in a nuclear membrane
Plasmalemma (Fungal Membrane) Outline
Phospholipid bilayer: containing transport proteins and sterols (mainly ergosterol, as opposed to mainly cholesterol in humans)
Fungal Cell Wall Outline
chitin (n-acetylglucosamine sugars)(innermost layer), beta 1, 3 glucans (glucose polymers and chitin complex), mannose proteins (outermost layer)
Ergosterol Outline
Large component of fungal plasmalemma. Antifungals target different enzymes during ergosterol formation. Plasmalemma becomes leaky of cell contents killing cell
Terbinafine Outline
Antifungal that that targets first step in ergosterol formation. Inhibits squalene epoxidase that converts squaluene to 2,3-oxidosqualene
Azoles Outline
Antifungal that targets last step in ergosterol formation. Inhibits 14 alpha demethylase which converts lanosterol into ergosterol
Yeast Cells Outline and Examples
Unicellular, round organisms. Scchroymers and cryptococcus. Cryptococcus id differentiated by having a carbohydate capsule
Budding Outline
Nucleus divides in 2. 1 nucleus stays in cell and 1 moves into a swelling in cell. Swelling snaps off of the cell. Forms 2 identical cells
Superficial mycoses Outline
Fungal infection on skin’s surface
Example of psuedo yeast
White colonies on sarboughed (acidic, with antibiotics) or blood agar
Filamentous Fungi (Mould) Outline
Multicellular, filamented fungi composed of hyphae (intertwined branching structures). Expand longitudinal. Spread by spores
Hyphae Outline
Branching tubular structures divided by septa (cross walls). 2 types:vegetative and aerial. Hypha = a single fungal filament. Mycelium= mass of hyphae
Vegetative Mycelium Function
Anchors mould to surface and absorbs nutrients
Aerial Mycelium Function
Release spores for mould asexual reproduction
Dimorphic fungi
Fungi that grow as a mould outside of body (hyphae and spores) but grow by budding (like yeast) inside of body and grows a capsule.
Dimorphic Fungi Example
Histoplasma capsulatam
Subcutaneous mycoses Outline
Fungal infection in lower layers of skin
Systemic Mycoses Outline
Fungal infection in circulatory system
Dermatophytes Outline
Fungi that cause superficial and subcutaneous infection of the hair, nails and skin (called ringworm or tinea infections) eg epidermophyton
Candida Albicans Outline
Ranges from superficial (eg Thrush) and to systemic
Aspergillus Outline
Aspergillus fumigatus causes systemic infections in immunocompromised individuals
Cryptococcus numoformans
Systemic infection causes
Pneumocystis Jirovec
Opportunistic pnuemonia infection in patients with HIV
Histoplasma Capsulatum Outline
Causes systemic infection in even immunocompetent individuals due to it’s dimorphic nature
How fungal infections are diagnosed clinically
Superficial inspection (eg thrush), symptomatic (eg fever) and no response to broad spectrum antibiotics
Taking fungal specimens from patients
Blood, sterile site sample and tissue
How are fungi detected under microscope
Budding conidia, pseudo hyphae, stained purple by gram stain and germ tube test (specifically candida)
Protozoa Outline
Unicellular, eukaryotic microorganisms. parasitic. Exist in soil and water
2 Protozoa Classes
Intestinal & urogenitial and blood & tissue
Types of intestinal and urogenital protozoa
Amoeba (entamoeba histolytica, abdominal cramps), flagellates (giardia labia, diahorrea), ciliates (blantidium coli, abdominal cramps), coccida (mild diahorrea (worse in immunocompromised)
Types of blood and tissue protozoa
Coccida (plasmodia flacicarium, causes malaria in blood) and flagellates (leismania, infection of skin tissues, fever and weight loss)
Malaria interactions with quinine
Quanine interefers with maliaria causing pathogens lysosomes and nucleic acid synthesis
Coccida interactions with chlorooquinine
Chloroquinine alters pH of coccida vacuoles, disrupting cell processes
Primaquinine Mode of Action
Attacks Coccids in blood and liver dirupting nucleic acid synthesis
Sulphadoxide and pyrimethamine Mode of Action
Folic acid enzyme antagonists (parasites require folic acid to function).
