Environmental Candida auris and the Global Warming Emergence Hypothesis

Area of Science:

• Environmental microbiology
• Climate change impact
• Medical mycology

Background:

• Global warming has been hypothesized as a driver for the emergence of *Candida auris* (a multidrug-resistant fungal pathogen) as a nosocomial threat.
• The global warming emergence hypothesis suggests *C. auris* adapted to higher temperatures, facilitating its transition from an environmental organism to a human pathogen.
• The simultaneous emergence of distinct *C. auris* clades across continents necessitates an explanation for its rapid global spread.

Purpose of the Study:

• To investigate the environmental presence of *Candida auris* to test the global warming emergence hypothesis.
• To determine if environmental isolates of *C. auris* exhibit thermal characteristics consistent with recent adaptation to higher temperatures.
• To establish *C. auris* as an environmental organism, a prerequisite for the global warming emergence hypothesis.

Main Methods:

• Isolation of *Candida auris* from environmental samples in the Andaman Islands.
• Comparative growth analysis of environmental and clinical *C. auris* strains at different temperatures, including mammalian body temperature.
• Assessment of environmental niches for *C. auris*.

Main Results:

• Successful isolation of *Candida auris* from two distinct environmental sites in the Andaman Islands, confirming its status as an environmental organism.
• One environmental isolate demonstrated slower growth at mammalian temperatures compared to clinical strains, suggesting recent thermal adaptation.
• The findings provide initial evidence supporting the environmental origin and thermal adaptation of *C. auris*.

Conclusions:

• The recovery of *Candida auris* from the environment supports the global warming emergence hypothesis.
• Environmental isolation and observed thermal characteristics of *C. auris* suggest a link between climate change and its emergence as a pathogen.
• Further research into *C. auris* ecological niches and environmental isolate analysis is crucial for validating or refuting the global warming emergence hypothesis.