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Flashcards in Introduction to Fungi Deck (26)
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1
Q

What can fungi infect?

A
  • Plants
  • Insects
  • Amphibians
  • Mammals
2
Q

What is mycology?

A

The study of fungi

3
Q

What is a fungi?

A

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
Q

What are the 3 groups of fungi?

A
  • Basidiomycetes
  • Ascomycetes
  • Zygomycetes
5
Q

What are the sexual and asexual spores of each group?

A
Basidiomycetes
-S:basidiospores
-A:conidium
Ascomycetes
-S:ascospores
-A:conidium
Zygomycetes
-S:zygospore
-A:sporangiospores
6
Q

What are examples of ascomycetes?

A
  • Candida

- Aspergillus spp

7
Q

What is an example o of a basidiomycete?

A

Crytococcus species

8
Q

What is an example of a zygomycete/

A

Rhizopus species

9
Q

What are yeasts?

A

Fungi that favour a unicellular habit

10
Q

What non-fatal diseases can fungi cause?

A

-Athletes foot: Epidermophyton, Microsporum and Trichophyton spp
-Thrush:Candida
Pityriasis veriscolor: Malssezia spp

11
Q

What are ringworm infections usually called?

A

Tinea…

12
Q

What is dermatophytosis caused by?

A

Moulds with a dredilection to degrade keratin as a nutrient source

13
Q

What are the causative agents of dermatophytosis?

A
  • Epidermophyton
  • Microsporum
  • Trichophyton spp
14
Q

What is the causative agent of pityriasis veriscolor?

A

Malassezia spp

15
Q

What is pityriasis veriscolor caused by?

A

Yeasts that also form hyphae in infected skin

16
Q

What group of immunocompromised individuals does Candida species affect?

A

Infect deep organs of patients with various types of immune dysfunction e.g. after abdominal surgery, burns

17
Q

What group of immunocrompromised individuals does Aspergillus species affect?

A

Infect deep organs of patients undergoing chemotherapy and stem cell transplantation

18
Q

What factors contribute to pathogenicity of fungal infections?

A
  • Favourable micro-environments
  • Broad-spectrum antibacterial agents reduce competition for epithelial colonisation sites in gut
  • Immunosuppression
19
Q

What are examples of iatrogenic immunosuppression of host defenced?

A
  • Steroids
  • Anti-cancer chemotherapy
  • Solid-organ transplantation
20
Q

What are examples of disease process that can immunosuppress host defenced?

A
  • AIDS
  • Leukaemia
  • Endocrinopathies
21
Q

Describe candida specie.

A
  • Commensal to GI tract
  • Most infections are enogenous
  • Candida spp are yeasts
  • C.albicans can form hyphae
22
Q

What infections can Candida spp cause?

A
  • Superficial of mouth, vagina, penis, skin, nails

- Deep-seated: disseminated infections in seriously immunocompromised hosts

23
Q

How can chronic mucocutaneous Candida infections arise?

A

In individuals with an unusual combination of endocrine and immune dysfunction

24
Q

Describe aspergillus spp.

A
  • Moulds
  • Ubiquitous in the environment: infection occurs by spore inhalation
  • strongly angioinvasive
25
Q

What is invasive pulmonary aspergillosis mainly associated with?

A

Haemotological malignancy

26
Q

What diagnostic methods are used in mycology?

A
  • Direct detection (histopathology, CT)
  • Detection of circulating fungal antigens
  • Detection circulating antibodies to fungi
  • PCR for fungal DNA
  • Culture of fungus from normally sterile site