Flashcards in Introduction to Fungi Deck (26):
1
What can fungi infect?
-Plants
-Insects
-Amphibians
-Mammals
2
What is mycology?
The study of fungi
3
What is a fungi?
A chemo-organotropic eukaryote that lacks chlorophyll and forms spores. Its cell wall contains polysaccharides, often, chitin or glucan and it absorbs nutrients. Its membrane contains egosterol as the major sterol.
4
What are the 3 groups of fungi?
-Basidiomycetes
-Ascomycetes
-Zygomycetes
5
What are the sexual and asexual spores of each group?
Basidiomycetes
-S:basidiospores
-A:conidium
Ascomycetes
-S:ascospores
-A:conidium
Zygomycetes
-S:zygospore
-A:sporangiospores
6
What are examples of ascomycetes?
-Candida
-Aspergillus spp
7
What is an example o of a basidiomycete?
Crytococcus species
8
What is an example of a zygomycete/
Rhizopus species
9
What are yeasts?
Fungi that favour a unicellular habit
10
What non-fatal diseases can fungi cause?
-Athletes foot: Epidermophyton, Microsporum and Trichophyton spp
-Thrush:Candida
Pityriasis veriscolor: Malssezia spp
11
What are ringworm infections usually called?
Tinea...
12
What is dermatophytosis caused by?
Moulds with a dredilection to degrade keratin as a nutrient source
13
What are the causative agents of dermatophytosis?
-Epidermophyton
-Microsporum
-Trichophyton spp
14
What is the causative agent of pityriasis veriscolor?
Malassezia spp
15
What is pityriasis veriscolor caused by?
Yeasts that also form hyphae in infected skin
16
What group of immunocompromised individuals does Candida species affect?
Infect deep organs of patients with various types of immune dysfunction e.g. after abdominal surgery, burns
17
What group of immunocrompromised individuals does Aspergillus species affect?
Infect deep organs of patients undergoing chemotherapy and stem cell transplantation
18
What factors contribute to pathogenicity of fungal infections?
-Favourable micro-environments
-Broad-spectrum antibacterial agents reduce competition for epithelial colonisation sites in gut
-Immunosuppression
19
What are examples of iatrogenic immunosuppression of host defenced?
-Steroids
-Anti-cancer chemotherapy
-Solid-organ transplantation
20
What are examples of disease process that can immunosuppress host defenced?
-AIDS
-Leukaemia
-Endocrinopathies
21
Describe candida specie.
-Commensal to GI tract
-Most infections are enogenous
-Candida spp are yeasts
-C.albicans can form hyphae
22
What infections can Candida spp cause?
-Superficial of mouth, vagina, penis, skin, nails
-Deep-seated: disseminated infections in seriously immunocompromised hosts
23
How can chronic mucocutaneous Candida infections arise?
In individuals with an unusual combination of endocrine and immune dysfunction
24
Describe aspergillus spp.
-Moulds
-Ubiquitous in the environment: infection occurs by spore inhalation
-strongly angioinvasive
25
What is invasive pulmonary aspergillosis mainly associated with?
Haemotological malignancy
26