Lecture 14: Candida auris

Question 1

Give an example of unicellular vs. multicellular fungi. How does each type reproduce?

Answer 1

1. Unicellular: yeast
   - Reproduce by budding
2. Multicelular: molds
   - Reproduce asexually through spores

Question 2

Most fungi are opportunistic but _____ fungi are true pathogens.

Answer 2

dimorphic

Question 3

What is candidiasis? What causes it? What are the types of infections? What is the first line of treatment?

Answer 3

1. Opportunistic infections caused by Candida spp. (part of the microflora)
2. Most infections caused by Candida albicans
   - Other common species: C. glabrata, C. parapsilosis, C. krusei, and C tropicalis
3. Vaginal (yeast infection), oral (thrush), UTI, skin and nails
4. Fluconazole

Question 4

What is invasive candidiasis? What are its 3 major routes to the bloodstream?

Answer 4

1. Systemic spread of the Candida yeast
2. GI tract, intravascular catheter, from a localized infection

Question 5

When was Candida auris first identified? When did reporting begin? When did it become a national notifiable disease? When did the first identified case occur?

Answer 5

1. 2009: isolated from external ear canal discharge of a patient in Japan
2. C. auris reporting began in 2016
3. 2018: became a national notifiable disease
4. 2013: first identified case

Question 6

What is the mortality rate of C. auris? Why is it so high?

Answer 6

30-60%
- Resistant to antifungals
- No concrete documentation for theraputic options for infection

Question 7

Explain how C. auris emerged and spread.

Answer 7

1. Global warming is responsible for raising ambient climate temperatures, which selects fungal clades that can reproduce at avian and mammalian basal temperatures
2. C auris previously existed as a plant saprophyte that gained thermotolerance and salinity tolerance as a result of the effects of climate change on ht wetland ecosystem
3. Thermotolerant C. auris may have been transplanted by birds across the globe to rural areas where human and birds are in constant contact
4. Rural environment activities (e.g. farming) provide the opportunity for interspecies transmission of virulent pathogens such as C. auris