Fungal diseases Flashcards
What are the three main ways a fungi may pathogenically effect a human ?
- Mycoses (true infection)
- Mycotoxicoses (ingestion of micro or macro fungal toxins
- Allergies(Inhalation oospores triggering inflammation e.g hay fever)
How many poisonous and how many Fatal macro fungi produce mycotoxicoses in the uk ?
There are 20 poisonous and 5 fatal species.
What is the Latin name of the death cap ?
Amanita phalloides
How do symptoms occur after ingesting the death cap. mushroom ?
6-24 h delay until vomiting and diarrhoea. 1-2 days after it will seem as if symptoms have subsided. 1-2 days later after that then death will occur.
How do death caps kill humans ?
Phalloidin toxins toxins effect the liver. Amantin effects the liver and kidney.
What is the name for toxic black mold and how does it infect a human ?
Stachybotrys. Ihalation of spores cause hay fever. Sporesare able to grow saprotrophically in the mucus of the lung; forming a localised ball of hyphae. If reaches blood stream may become systemic and true mycoses will occur e.g Aspergillosis.
What are the main features of a superficial/ cutaneous fungal infection ?
- Parasites with poor saprotrophic ability.
- Colonise dead keratinous layers
- Contagious via dead skin or hair cells
- Create prorating and frond hyphae
Give two examples of superficial/ cutaneous fungal infections and their Latin names ?
Ringworm- Tinea corporis
Athletes foot-tines pedis
How does perforating and frond hyphae occuronthe skin ?
Hyphae grows on the substrate surface. Perforating hyphae grow into the tissue. Frond hyphae grows in a plane of weakness; force layers apart causing flaking.
What are the main features of systemic mycoses ?
- Saprotrophic
- Mycelial or yeast (usually yeast)
- Dimorphic (can convert from Yeats to hyphae and back again)
- Enter via the wounds of usually debilitated patients.
What is Cryptococcosis caused by and what are its characteristics ?
Cryptococcus neoformans. Basidiomycete yeast, saprotrophic.
What are the three main forms of disease from cryptococcosis ?
Pulmonary(10%), skin/ bone lesions (10%) and CNS (80%).
What is the main fatal disease caused by crytococcus neoformans ?
Meningitis. Mortality for HIV associated cryptococcal meningitis Is 10 - 30 % in developed countries and as high as 44% in Africa.
What is neurotropism and why is it strong in Crytococcis ?
Neurotropism is the ability to infect the nervous system. Cryptococci require thiamin which is used a lot to contract the nerves in the nervous system meaning thatit is easily able to infect.
What is Candidiasis caused by ?
Candida spp- especially C.albicans
