Micro Flashcards
What is mycology?
The scientific study of fungi
What are some characteristics of fungi?
Eukaryotic Non-motile, rigid cell wall (chitin) Can be unicellular(yeasts) or multicellular (moulds) Saprophytes (feed of decomposing matter) or parasites Aerobes, some faculties anaerobes. Complex repro Classes based on sexual spores Insensitive to antibacterial antibiotics
Describe chitin and where it is found.
Chitin is a protective layer of chains of N-acetylglucosamine which is highly resistant to enzymatic breakdown. It is found within the fungal cell wall.
Discuss yeasts.
Type of fungi. Unicellular, spherical cells, 3-5um.
Reproduce asexually by budding, moist/mucoid colonies, facultive anaerobes.
Discuss moulds.
Filamentous fungi eg. Penicillin, microsporum.
Multicellular filaments, 2-10um wide (Hypae), can be septate(divided by cross walls), nonseptate (coencytic) or vegetative or aerial.
Reproduce sexually(spores) or asexually(condida)
Aerobic
Intertwined mass hyphae (mycelium/thallus)
What do septate hyphae possess that nonseptate don’t?
Septa-cross walls
Penicillin is septate, rhizopus is nonseptate
What are the two types of functional fungal hyphae? Briefly describe the cycle between the two.
Vegetative hyphae, reproductive hyphae
VH present on surface, fruiting bodies begin to grow and produce spores (RH), spores germinate into germ tube, hypha and then become vegetative hyphae again.
What temperatures are required for dimorphic fungi to grow in vitro and in Vivo?
In vitro - 25degrees Celsius
In Vivo - 37degrees Celsius
True or false. Many fungal species have a full lifecycle with both asexual and sexual states that are separated in time.
True
What is the sexual stage of a fungi lifecycle called?
Telomorphic.
Meiosis occurs producing meiospores.
What is the asexual period of a fungi lifecycle called?
Anamorphic.
Mitosis produces mitospores.
What are some types of asexual Filamentous fungal spores (mould)?
Sporangiospores.
Conidia.
What are the four main fungal classes?
Zygomycetes, ascomycetes, basidiomycetes, deuteromycetes.
What is pathogenicity?
Capacity to produce disease.
To cause disease a fungus must….
Enter host, multiply in host tissue, resist or not stimulate host defence, damage host.
What are the four forms of fungal disease in animals?
Infectious-parasitic fungi, mycoses.
Toxigenic-saprophyte or plant, mycotoxicoses.
Allergenic-sensitisation, mainly spores.
Effects on non-toxic spoilage-feed refusal, nutritional deficiencies.
What are the stages of fungal disease diagnosis?
The first 4 are the main forms.
- Clinical behaviour and appearance of lesions.
- Cytology of exudate/tissues-gram stain, KOH, etc.
- Fungal culture and appearance-macro and microscopic.
- Histopathology-gram stain, H&E, Etc.
- Immunofluorescence tests
- Molecular methods
- Skin tests
- Serology
- Animal inoculation
What are the differences between the microscopic morphology of yeasts and moulds?
Yeasts may have buds, capsules and germ tube production.
Moulds have hyphae, sexual spores or asexual conidia.
What is the term for fungal diseases in animals?
Mycoses.
These can be systemic/deep, cutaneous and subcutaneous.
What are the three domains of life?
Eukarya, bacteria, archaea
What are bacteria and archaea?
Prokaryotes-before nucleus
What is microbiology?
The study of micro organisms.
True or false, viruses are acellular?
True
True or false. Fungi and Protozoa are both eukaryotes?
True