7. Intro to Fungi

Question 1

At what temperature does the Aspergillus species normally thrive?

Answer 1

Room temperature

Question 2

Cryptococcus neoformans is most often found where?

Answer 2

Pigeon faeces

Question 3

What is a risk factor for candidiasis infection?

Answer 3

Use of broad spectrum antibiotics

Question 4

Pneumocystis jiroveci (previously P. carinii) is best described as which type of fungus?

Answer 4

Yeast-like

Question 5

Are fungi prokaryotic or eukaryotic?

Answer 5

Eukaryotic

Question 6

What molecule is found in fungal cell membranes?

Answer 6

Ergosterol

Question 7

What parts of the fungal cell wall give it rigidity?

Answer 7

Chitin

Carbohydrates (mannans)

Question 8

What added protection does a capsule give?

Answer 8

Antiphagocytic

Question 9

How does yeast appear on culture?

Answer 9

Moist-waxy colonies

Question 10

How does a yeast-like fungus appear on culture?

Answer 10

Creamy white colonies

Question 11

What type of fungus is cryptococcus?

Answer 11

Yeast

Question 12

What type of fungus is candida albicans?

Answer 12

Yeast-like

Question 13

How do moulds reproduce?

Answer 13

Spore formation

Question 14

How can a dimorphic fungus behave like both a mould and a yeast?

Answer 14

Act as a mould from 25-30C

Yeast in humans at 35-37C

Question 15

How are superficial infections diagnosed?

Answer 15

Skin scrapings or nail clippings

KOH microscopy

Question 16

What superficial infection presents as an itchy, dry rash, commonly on the trunk and neck?

Answer 16

Pityriasis Versicolor

Question 17

What factors are often related to a pityriasis versicolor infection?

Answer 17

Hot, humid climate

Excessive sweating

Question 18

What is the topical treatment for pityriasis versicolor infection?

Answer 18

Azoles, selenium sulphide

Question 19

What is the oral treatment for pityriasis versicolor infecton?

Answer 19

Fluconazole, itraconazole

Question 20

What culture is used to grow tinea/ringworm?

Answer 20

Sabouraud sugar

Question 21

What treatment is given for tinea?

Answer 21

Oral terbinafide

Topical antifungals and keratolytic agents

Question 22

Which fungus causes a subcutaneous infection?

Answer 22

Sporotrichosis

Question 23

How does sporotrichosis present?

Answer 23

An ulcer on site of injury forms a granulomatous nodule

Question 24

How is sporotrichosis treated?

Answer 24

Itraconazole

Question 25

How is sporotrichosis treated if it spreads to the lungs?

Answer 25

Amphotericin B

Question 26

Which yeast causes meningitis in an immunocompromised patient?

Answer 26

Cryptococcus neoformans

Question 27

How does cryptococcus neoformans get into the body?

Answer 27

inhaled | Found in soil, bird faeces, rotting vegetation

Question 28

How is cryptococcus neoformans diagnosed?

Answer 28

Antigen is found in blood and CSF | India ink

Question 29

What dimorphic fungus causes an infection similar to TB?

Answer 29

Histoplasma capsulatum

Question 30

Where can histoplasma capsulatum disseminate to?

Answer 30

Liver, lungs, spleen

Question 31

How does Histoplasma capsulatum evade the immune system?

Answer 31

It can live within macrophages

Question 32

How does a candida skin infection present?

Answer 32

Red rash in warm, moist areas of skin

Question 33

How is a candida skin infection treated?

Answer 33

Topical: clotrimazole Oral: fluconazole

Question 34

How does candida appear under the microscope?

Answer 34

Budding yeasts with large purple cells

Question 35

What cultures does candida grow on?

Answer 35

Blood | Selective agar

Question 36

What disease is caused when aspergillus is inhaled by a patient with asthma or CF?

Answer 36

Allergic Broncho Pulmonary Aspergillosis | Results in a wheeze, cough and fever

Question 37

How is Allergic Broncho Pulmonary Aspergillosis treated?

Answer 37

Steroids | itraconazole

Question 38

How can an aspergilloma present?

Answer 38

Asymptomatic, chronic cough or haemoptosis

Question 39

What is seen on a CT scan if an aspergilloma is present?

Answer 39

Fluid filled cavity in thorax

Question 40

What does invasive aspergillosis cause in an immunocompromised patient?

Answer 40

Invasion of blood vessels causes haemoptysis and bleeding | Dissemination

Question 41

What is PJP seen as on a thorax CT?

Answer 41

Ground glass infiltrates

Question 42

How is PJP diagnosed?

Answer 42

Bronchoalveolar lavage

Question 43

What does PCP stain with?

Answer 43

Methanamine silver/grocott