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Flashcards in Fungi L21 Deck (33):
1

Transmission of Candida

Infection is endogenous, although cross infection can also occur (eg from Mother to child or amongst infant siblings)

2

Characteristics of Candida

Found as spherical or oval budding yeast
Single cells or blastospores

3

What are pseudo hyphae?

Elongated filamentous cells joined end to end

4

When can pseudo-hyphae be seen?

At lower incubation temperatures and on nutritionally poor media

5

What are true hyphae?

True hyphae are thread-like tubes that contain the fungal cytoplasm and its organelles.

6

What culture do C. Albicans grow on? How do they appear?

Grows on sabouraud agar, as creamy white colonies, flat or hemispherical in shape

7

Under which agar with what conditions does C. Albicans grow?

Sabouraud agar
High sugar, Low pH conditions

8

5 predisposing factors for growth of candida

1. Chronic local irritants
2. Ill-fitting appliances
3. Dietary factors
4. Immunological disorders
5. Endocrinal disorders

9

What does superficial candidiasis affect?

Mainly the skin and epithelial surfaces

10

4 conditions caused by superficial candidiasis

- mucosal infection/thrush
- candida intertrigo
- nappy rash
- candida paronychia

11

What does mucocutaneous candidiasis affect?

Involves both the skin and the underlying mucosa

12

What deficiency is chronic mucocutaneous candidiasis associated with?

T cell deficiency

13

Treatment for chronic mucocutaneous candidiasis?

Systemic anti-fungal therapy

14

Where does systemic/deep candidiasis occur?

In most organs following candidaemia (candida in blood)

15

Who are at risk of systemic/deep candidiasis? (X3)

Seriously ill patients
Patients who had heart surgery/organ transplant
Patients who are on Long term immuno suppression drugs/drug therapy

16

4 forms in which oral candidosis could present in?

1. Pseudo-membranous candidosis (PMC/thrush)
2. Erythematous candidosis
3. Angular cheilitis
4. Chronic hyperplastic candidosis (candida leukoplakia)

17

Name four groups of people who are likely to get erythematous candidosis

1. Denture wearers
2. Prolonged drug therapy - antibiotics / topical steroids
3. Persistent PMC
4. AIDS patients

18

Treatment for patients with erythematous candidosis caused by denture-wearing (x3)

1. Topical antifungal agents - chlorhexidine
2. Clean Dentures
3. removal of dentures at night

19

Treatment for patients with erythematous candidosis caused by prolonged drug therapy

Topical antifungal agents
Stop administration of antibiotics

20

What is angular cheilitis caused by?

Overgrowth of C. Albicans at the angle of the mouth

21

Groups of people prone to angular cheilitis? (X2)

1. Denture wearers
2. People with vitamin deficiencies (iron and vit b12)

22

Treatment of angular cheilitis (x2)

1. Resolve underlying problem
2. Antifungal agents

23

If a patient presents with individual lesions of red/white speckled patches, with the surface being parakeratinised and hyperplastic, what disease could it be?

Chronic hyperplastic candidosis (candida leukoplakia)

24

Symptoms of chronic leukoplakia

- individual lesions
- red/white speckles
- parakeratinised and hyperplastic surface

25

Virulence factors contributing to the adherence of C. Albicans (x4)

- hyphal form
- hydrophobic surface contains non-specific adherence process
- expansion of cell surface specific adhesion molecules
- fibrillary mannoprotein

26

Virulence factors of C. Albicans promoting host defences/damage

Secreted aspartyl proteinases (SAPs)
Phospholipase
Concentrated at hyphal tip

27

Name 3 main groups of antifungal agents

1. Polyenes
2. Azoles
3. Antimetabolite - 5-fluorocytosine

28

Give 2 examples of Polyenes

1. Amphotericin B
2. Nystatin

29

Mode of action of Polyenes

Binds to ergosterol in fungal lipid membrane - makes the membrane leaky

30

Name a fungicidal agent and a fungistatic agent

Fungicidal: Polyenes
Fungistatic: Azoles

31

Name the Azoles (x5)

Imidazoles - miconazole and ketoconazole
Triazoles - itraconazole, fluconazole, triazole

32

Name an example of an anti metabolite

5-fluorocytosine

33

Habitat of Candida

Indigenous to the oral cavity, GI tract, female genital tract and sometimes the skin