Mycology Flashcards
How do fungi reproduce?
By both sexual (meiosis) and asexual (mitosis) spores.
What are the two main morphological forms?
Moulds and yeasts.
What are hyphae?
Basic cell unit of moulds.
An apically elongating cylinder capable of branching.
Acellular, with several nuclei per segment.
What are mycelia?
Networks of hyphae forming body of mould.
Can consist of submerged vegetative mycelium and aerial mycelium.
Describe yeasts.
Alternative growth form to the hypha.
Consists of discrete, often ovoid cells.
Reproduce by budding.
What is a dimorphic fungi?
Can produce both yeasts and hyphae, depending on environmental conditions.
Define pseudo-mycelium.
Intermediate form of growth between hyphae and yeasts, in which elongated budding cells form “pseudohyphae”.
Define colony.
A mycelium or mass of yeast cells in culture, usually grown from a single hyphal fragment or yeast cell.
In what three ways can fungi be pathogenic?
Mycosis = infection
Allergy = inhaled spores
Toxicosis:
Mycotoxicosis = spoiled feed
Mycetism = ingesting poisonous fungi
What are the endogenous and exogenous sources of infection?
Endogenous = commensal flora
Exogenous = free-living saprophytes / parasitic on another animal host
What are the three different types of infection (mycoses)?
Superficial - epidermis, nail/hair/claws/spines/feathers
Subcutaneous - traumatic inoculation through skin
Deep - inhaled, deep wound or endogenous
How is cattle ringworm treated?
Topical: Miconazole (shampoo), Enilconazole (wash/spray)
Systemic: Griseofulvin, Terbinafine/Itraconazole (not licenced)
Are deep mycoses contagious, and what predisposes an animal to infection?
Not contagious
Opportunistic - age / immunosuppression / trauma / exposure to heavy spore loads