Candida

Question 1

where can Candida spp. normally be found?

Answer 1

part of the microbiota of the skin, alimentary canal and vagina

Question 2

what is usually the cause of candida infections?

Answer 2

usually endogenous

but direct person to person transmission can occur

Question 3

who is usually at risk for Candida infections?

Answer 3

healthy individuals can be infected however pre-disposing factors are usually required.
new borns, elderly, HIV, diabetes, leukaemia patients

Question 4

what is the pathogenesis of Candida?

Answer 4

epithelial adhesion and nutrient acquisition.
epithelial penetration and degradation of host proteins.
tissue penetration, vascular invasion and immune evasion or escape
endothelial adhesion, infection of host tissues and activation of coagulation and blood clotting cascades

Question 5

what are some Candida virulence factors?

Answer 5

adhesins
hydrolytic enzymes
hypha formation

Question 6

where does candidiasis typically infect as a superficial infection?

Answer 6

mouth or vagina

Question 7

what are the symptoms of oral candidiasis?

Answer 7

white plaques on the oral mucosa 
unpleasant taste 
sore and painful mouth 
burning mouth or tongue 
dysphagia

Question 8

what are the symptoms of genital candidiasis?

Answer 8

itching 
burning 
soreness 
irritation 
pain on urination and/or during sex 
white cottage cheese-like discharge

Question 9

what are the symptoms of cutaneous candidiasis?

Answer 9

patches of red, moist, weepy skin appearing as a rash

Question 10

what are the symptoms of gastrointestinal candidiasis?

Answer 10

anal itching 
bloating 
indigestion 
nausea 
vomiting 
gastric ulcers 
intestinal cramps

Question 11

what type of specimen is used for candida diagnosis?

Answer 11

charcoal transport media swab
mid stream urine
biopsy
blood culture

Question 12

what selective media is used in candida diagnosis? what conditions are needed?

Answer 12

sabouraud dextrose agar
35-37 degrees
in air
for 16-48 hours

Question 13

what differential media is used in candida diagnosis? what conditions are needed?

Answer 13

candida chromogenic agar
incubated at 30 degrees
in air
checked for growth every 24 hours

Question 14

how is microscopy used for candida diagnosis?

Answer 14

direct wet prep microscopy
use gram stain
appear as gram positive oval thin walled budding yeast cells

Question 15

how is the germ tube test used for candida diagnosis?

Answer 15

presumptive identification test used to differentiate species
species produce germ tubes when in a liquid environment
further tests required for differentiation

Question 16

what biochemical tests can be used for candida diagnosis?

Answer 16

API candida system

10 tubes which allows 5 carbohydrate acidification tests and 7 enzymatic tests

Question 17

how do you treat superficial candidiasis?

Answer 17

topical treatments include nystatin or imidazole drugs

oral fluconazole or itraconazole can be used for unresponsive infections

Question 18

how do you treat invasive or disseminated candidiasis?

Answer 18

an echinocandin is the first line of treatment

fluconazole, amphotericin B and voriconazole can be used as an alternative

Question 19

how do azoles work?

Answer 19

inhibit the enzyme involved in ergosterol synthesis

Question 20

how do echinocandins work?

Answer 20

inhibit the synthesis of beta glucan in the fungal cell wall via non competitive inhibition of an enzyme

Question 21

how can you prevent candida infections?

Answer 21

maintain good personal and oral hygiene
eat a balanced diet which contributes to a healthy microbiota
only take antibiotics when necessary and as directed