Mycology Flashcards
What is Mycology?
Mycology: The Study of Fungus
Mycoses: Fungal Infection
Includes:
Molds (Multicellular)
Yeasts (Unicellular)
What Domain Are Fungi In?
Eukarya
What Are Some Features Of Fungi?
- Either Unicellular/Multicellular
- Heterotrophic (unable to produce their own
food) - Need Oxygen for Survival
- Stain Gram+
- Cell Wall made of Chitin
What is the Fungal Cell Wall Composed Of?
Chitin Layer:
- Rigid, Nitrogen-containing Polysaccharide
- Made of N-acetylglucosamine repeat units
- Prevents collapse under osmotic pressure
Glucan Polysaccharides:
- Provides Flexibility + Strength To Cell Wall
- Branched Glucose Polymers
- Composed of β-1,3-Glucans + β-1,6-Glucans
- Form Fibrous Network Intertwined with chitin
Ergosterol within membrane:
- Maintains Fluidity + Stability under Temp
changes - Regulates Membrane Permeability +
Membrane bound Enzyme Activity
What Are the 4 Fungi Types?
- Chytridiomycota
- Zygomycota
- Basidiomycota
- Ascomycota
Describe Ascomycota.
3 Major Subdivisions:
- Saccharomycotina:
Unicellular Yeasts that reproduce by asexual
Budding - Taphrinomycotina:
Multicellular Hyphae, Reproduce by Sexual
Spores - Pezizomycotina:
Multicellular Hyphae, Reproduce by Sexual
Fission/ Asexual Spores
Describe Saccharomycotina.
Consist of 1 class: Sacchatomycetes
- Unicellular
- Have Cell Wall made of Chitin
- Able To Bud
Hoe Do Saccharomycotina Reproduce?
Via Asexual Budding
- Parent Nucleus Split + Migrates into
Daughter Cell - Cytoplasm Divides to create new Yeast Cell
- Yeast form Pseudo-hyphae (chains)
How Do Saccharomycotina Infect? Are They harmful?
Caused by Candida Albicans
- C. Albicans Colonizes in Bodies, doesn’t
harm - Lives in Moist + Warm conditions
- Infections called Candidiasis
Harmful To:
- Pregnant Individuals
- Antibiotic Therapy
- Immunocompromised Individuals (HIV)
Explain 2 Candida albicans Infections.
Oral Thrush
Overgrowth of C. albicans on tongue
White spots seen down the throat
Common in Individuals with Dentures
Vaginal Thrush
C. albicans Overgrowth in Vaginal Tract
Common in Individuals with IUDs
Symptoms:
- Thick, Cottage Cheese like Discharge
- Painful Urination
Describe The Diagnosis Test For C. albicans.
- C. albicans cultured onto Saboraud agar
- Plate taped + Incubated at 37°C for 48 hours
KOH Test: (Potassium Hydroxide)
- KOH Drops Added to Sample
- Heat Sample to Speed Up Reaction
(Chemical)
Germ Tube Test (GTT)
Differentiates albicans from other Yeasts
Procedure:
- 0.5ml Sheep/Human Serum added to Small
Tube - Colony of Yeast added to Serum
- Tube Incubated at 37°C for 2-4 Hours
- Drop Of Serum added to Slide For
Examination - Examine Microscopically
What is an Industrial Use of Saccharomycotina?
- Baking
- Alcoholic Drinks (Ethanol Production)
Describe Pezizomycotina.
Over 15 Classes, but in debate because of DNA Analysis
How Do Pezizomycotina Reproduce?
Asexual Reproduction (Mitosis)
Conidiophore releases spores
Germination Occurs
Sexual Reproduction (Meiosis + Mitosis)
Ascogonium (Male)
Antheridium (Female)
- Nuclei in asci form a diploid zygote
- Meiosis occurs and 4 Haploid ascospores
form - Mitosis Occurs To give 8 Haploid
Ascospores
Explain 2 illnesses caused by Pezizomycota.
Aspergillosis:
Lung Infection caused by aspergillus (any) Commonly asperigillus niger
Dermatophytosis:
Skin/Hair/Nail infection
Caused by Dermatophytes
Examples: Ringworm/Athlete’s Foot
Athlete’s Foot:
- Commonly caused by T. rubrum
- Test: Lactophenol Cotton Blue Staining + SAB
Agar
Explain An Industrial use of Pezizomycota.
Penicillin Production
Reason:
Penicillium is a genus of Fungi found within pezizomycotina
Describe Aspergillus fumigatus:
Risk Factor: Immunocompromised Patients
Symptoms:
1. Shortness of breath
2. coughing mucus
Causes: Aspergillus fumigatus (Most Common)
Lab Test: Culture of sputum onto SAB agar
Treatments:
1. Antifungal Tablets
2. If aspergilloma has grown: Surgery
