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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

What diagnostic methods are used in mycology?

-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