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Principles of Disease > Introduction to Fungi > Flashcards

Flashcards in Introduction to Fungi Deck (28):
1

What does the cell wall of a fungus contain?

Polysaccharides, often chitin or cellulose.

2

Does a fungi form spores?

Yes

3

Does a fungi contain chlorophyl?

No

4

What is the informal classification of fungi?

moulds yeasts or mushrooms

5

What is the cell type of a fungi?

They favour a unicellular habit

6

What kind of infections are by dermatophytes?

It is a pathogenic fungus that grows on body surfaces and causes ringworm and related diseases

7

What is the prefix for a ringworm infection?

tinea

8

What is the action of dermatophytes on keratin?

Moulds with a predilection to degrade keratin as a nutrient source.

9

What does a pityriasis versicolor cause on the skin?

Forms hyphae in infected skin

10

What do candida species infect?

Deep organs of patients with various types of immune dysfunction

11

What do aspergillus spp infect?

Infects deep organs of patients undergoing e.g chemotherapy, stem cell transplantation

12

What is a favourable micro-environment that will contribute to pathogenicity of a fungal infection?

Warm moist areas - encourages the growth of fungi on skin and mucous membranes. Broad spectrum antibacterial agents reduce competition for epithelial colonization sites in the gut. Immunosuppression of all types may create a window of opportunity for fungal invasion 

13

Describe the immunosuppression of host defences

Iatrogenic (caused by medical examination or treatment)

Steroids

Anti-cancer chemotherapy

Solid organ transplantation

Disease processes - Aids Leukaemia

Endocrinopathies

14

Where are candida species commensal to?

The GI tract

15

What are risk factors for candidiasis?

Age, antibiotic therapy, endocrine disorders, immune defects, immune suppression, surgery

16

What are the diseases possible as a result of candida?

Oral infections

Vaginal infections

Skin infections

Nail infections

Oesophageal infections

Disseminated infections - in seriously immunocompromised patients

17

What is hyphae?

The fine branching tubes which make up the body (mycelium) of a multicellular fungus

18

Give examples of superficial candida infections

Mouth, vagina, penis, skin, nails

19

Give examples of a seriously immunocompromised host

Suffering from neutropenia, abdominal surgery, major burns

20

Give examples of human diseases caused by Aspergillosis

Simple asthma Asthma with eosinophilia

Aspergilloma

Invasive bronchopulmonary aspergillosis Disseminated aspergillosis.

21

How does infection by aspergillus spp occur?

They are moulds ubiquitous in the enviroment - infection occurs by inhalation of conidia

22

Define conidium

A spore produced asexually by various fungi at the tip of a specialised hypha

23

Aspergillus is said to be angioinvasive, what does this mean?

Penetrates the walls of the blood vessels.

24

What is the causative species for cryptococcosis?

Cryptocuccus........(something)

25

What are the main diseases caused by cryptococcosis?

Pulmonary cryptococcosis

Meningitis (prevalent in AIDS patients)

26

What are the diagnostic methods for fungal infections?

Direct detection - histopathology (including direct smears and growth on selective medium) also the use of High resolution CT scans Detection of fungal antigens as well as antibodies to fungi

PCR for fungal DNA Culture of fungus from normally sterile site

27

What are the technical names for the three types of fungi?

Basidiomycetes (mushrooms) (cryptococcus)

Ascomycetes (candida, Aspergillus)

Zygomycetes (bread mould)

28