L9 - Fungal infections & chemotherapy

Question 1

2 cellular forms of fungal growth?

Answer 1

yeast cells

hyphae/mycelium = moulds

Question 2

what are the 3 different fungal lifestyles?

Answer 2

Saprophytism

Symbiosis (mutualism)

Parasitism

Question 3

What are common plant pathogenic fungi?

Answer 3

Wheat rust

Dutch Elm disease

Ash die-back

Fusarium wilt of banana

Question 4

What are the 3 different fungal infections?

Answer 4

superficial
subcutaneous
systemic

Question 5

What are superficial fungal infections?

Answer 5

skin, hair, nails mucosal surfaces

e.g. thrush, ringworm

Question 6

What are subcutaneous fungal infections?

Answer 6

subcutaneous tissues

sporotrichosis
chromoblastomycosis

Question 7

What are systemic fungal infections?

Answer 7

deep tissues

aspergillosis

systemic candidosis

histoplasmosis

Question 8

What are dermatophytes?

Answer 8

specialised fungi

exploit keratin

Question 9

What are infections caused by dermatophytes?

Answer 9

tinea pedis
tinea unguiuim
tinea capitis

Question 10

What happens during tinea pedis?

Answer 10

scaling

inflammation (low level)

Question 11

What are the 2 types of tinea capitis

Answer 11

black dots - hair follicle infected and falls out

ring worm - microsporum canis - autoinflammatory

Question 12

what is oral candidosis?

Answer 12

white plaques
sometimes red/inflamed

dimorphic fungus
elongated hyphae

Question 13

What is Sporotirchosisi?

Answer 13

Sporothrix schenckii

fungus travels down lymphatic system, emerges on skin

sphagnum moss

Question 14

How are systemic fungal infections diagnosed?

Answer 14

isolation of fungus from blood/tissue biopsy

Question 15

What is a “true” systemic fungal infection?

Answer 15

affect host regardless of imune status

Question 16

What is opportunistic fungal infection?

Answer 16

affect immune-compromised host

Question 17

What is systemic cadidosis?

Answer 17

present as candidaemia

blood, peritoneum, meninges, heart, bone, eye

Question 18

What are risk factors for systemic candidosis?

Answer 18

catheters
IV drugs
gut surgery
antibiotics 
immunosuppressants
prematurity

Question 19

How is candidosis diagnosed?

Answer 19

blood culture

biopsy

peritoneal fluid culture

serology

Question 20

What is SAFS (aspergillosis)?

Answer 20

Sever asthma with fungal sensitisation

Question 21

What is ABPA (aspergillosis)?

Answer 21

Allergic Bronchopulmonary Aspergillosis

Question 22

What is Aspergilloma?

Answer 22

fungus ball

Old TB cavity

Question 23

What is CPA (aspergillosis)?

Answer 23

chronic pulmonary aspergillosis

Question 24

What makes people more susceptible to invasive aspergillosis?

Answer 24

neutropenia

low neutrophil count

Question 25

How is aspergillosis diagnosed in the immunocompetent?

Answer 25

X-ray Chest CT culture sputum antibody tests

Question 26

How is aspergillosis diagnosed in the immunocompromised?

Answer 26

Chest CT Culture of BAL antigen tests PCR for DNA biopsy

Question 27

How was invasive aspergillosis proved?

Answer 27

transbronchial biopsy histological examination = tissue invasion

Question 28

What is mucormycosis caused by?

Answer 28

Moulds: Mucor Lichtheimia rhino-cerebral or pulmonary disease in immunocompromised

Question 29

What is cryptococcosis caused by?

Answer 29

cryptococcus neoformans pulomonary disease meningitis AIDS

Question 30

What is Histoplasmosis?

Answer 30

Histoplasma capsulatum dimorphic conidia inhaled from bird/bat roosts can spread to other organs mottled lungs (thought to be Tb)

Question 31

What are therapies for fungal infections?

Answer 31

recover w/out treatment surgery antifungals

Question 32

What are the 6 main classes of antifungals?

Answer 32

``` Pyrimidine Polyenes Allylamine Azoles Echinocandins Fungerps (new) ```

Question 33

What do Pyrimidine targte?

Answer 33

DNA & protein synthesis

Question 34

What do Polyene target?

Answer 34

plasma membrane

Question 35

What do Allyamine target?

Answer 35

Ergosterol biosynthesis

Question 36

What do Azoles target?

Answer 36

Ergosterol biosynthesis

Question 37

Wat do Echinocandins target?

Answer 37

Beta 1-3 glucan synthesis

Question 38

What do Fungerps target?

Answer 38

Beta 1-3 glucan synthesis

Question 39

What is Beta 1-3 glucan synthesis needed for?

Answer 39

cell wall

Question 40

What is Ergosterol biosynthesis needed for?

Answer 40

plasma membrane

Question 41

What is clinical resistance?

Answer 41

failure of patient to respond to antifungal therapy

Question 42

What is in vitro resistance?

Answer 42

failure of a fungus to be inhibited or killed by an anti fungal under GIVEN SET OF CONDITIONS