Microbiology 9- Fungal Infection Flashcards
The Fungus kingdom consists of two phyla:
Basidiomycota
Ascomycota
What are the two main type of fungal infections
ASCOMYCETES-
molds
90% of all human fungal infections
Basidiomycetes
consists of many of the mushrooms that we find
Out of the basidiomycetes, Cryptococcus neoformans and Cryptococcus gatii cause the largest burden of disease CRYPTOCOCCAL MENINGITIS
How do fungi digest their foods
Fungi digest their food extracellularly
They produce hydrolytic enzymes which are pumped out into the environment
They are powerful polymer degrading substances which rot the material around them - so the fungus is effectively suspended in its food source
This means that they are SAPROPHYTES
Three Types of Illness caused by Fungi
Allergies
Mycotoxicoses
Mycoses
What allergies can you get from fungi
Rhinitis
Dermatitis
Asthma
Allergic Broncho-Pulmonary Aspergillosis (ABPA)
What are myctoxicoses
DEFINITION: a toxic reaction due to the ingestion/inhalation of toxins produced by fungi
Mycotoxins are secondary metabolites of moulds that exert toxic effects on animals and humans
What are symptoms of myctoxicoses
what are the treatments
Breathing problems Dizziness Severe vomiting Diarrhoea Dehydration Hepatic and renal failure 6 days later
Treatment:
Gastric Lavage - wash out the toxins
Liver transplant
What is aflatoxin
produced by Aspergillus flavus is the most carcinogenic natural compound known
Contaminates grain
If you get aflatoxin poisoning and you have liver damage from hepatitis B then you are at particular risk of cancer
South-East Asia - higher rates of liver cancer possibly due to greater exposure to aflatoxin
What is mycoses
DEFINITION: disease caused by fungi which is classified by the level of tissue affected (superficial, cutaneous, subcutaneous, systemic)
What are superficial mycoses
Affecting skin or hair
No living tissue is invaded - no cellular response from host
What are Cutaneous mycoses
Produce keratinases which are capable of hydrolysing keratin
Inflammation is caused by host response to metabolic by-products
Trychopyton and Microsporum
Subcutaneous Mycosis
DEFINITION: chronic, localised infections of the skin and subcutaneous tissue following traumatic implantations of the aetilogic agent
Mycetoma - chronic infection of the skin, subcutaneous tissue and sometimes bone, characterised by discharging sinuses filled with organisms
Where is candida auris/ aspergillosis a big problem
hospital/Transplant settings
whats affected by superfical candida infections
Mouth, throat, skin, scalp, vagina, fingers, nails, bronchi, lungs or the GI tract
Usually due to impaired epithelial barrier function
Most common in the new born and elderly
What are risk factors of systemic candida infections
Chemotherapy
Gut-related surgery
Catheters
