Nav: Home

Is deadly Candida auris a product of global warming?

July 24, 2019

A drug-resistant fungus species called Candida auris, which was first identified ten years ago and has since caused hundreds of deadly outbreaks in hospitals around the world, may have become a human pathogen in part due to global warming, according to three scientists led by a researcher at the Johns Hopkins Bloomberg School of Public Health.

C. auris was first isolated from the infected ear of an elderly patient in Japan in 2009, and within a few years caused hospital outbreaks in many different parts of the world. Between 30 and 60 percent of patients diagnosed with invasive C. auris infection have died. C. auris's sudden emergence as a human-infecting pathogen is as mysterious as it is alarming, for it happened simultaneously among several distinct families or "clades" of this fungus that exist separately on different continents.

The scientists, in their paper published July 23 in the journal mBio, suggest that this global transformation of C. auris into a deadly pathogen may be due to global warming, which could have forced C. auris clades around the world to adapt to higher temperatures. That adaptation would have made it easier for this microbe to infect humans, whose relatively warm core temperature of 98.6 degrees Fahrenheit (37 degrees Celsius) normally serves as a "thermal barrier" against fungal invasion.

"We think that C. auris may be the first example of a fungal species that has jumped the thermal barrier due to adapting to global warming," says lead author Arturo Casadevall, MD, PhD, the Alfred and Jill Sommer Professor and Chair of the W. Harry Feinstone Department of Molecular Microbiology and Immunology at the Bloomberg School.

Microbiologists estimate there are more than a million fungal species. However, most known species are adapted for living in soils, on trees, and in other places in the natural environment, where temperatures on average are much cooler than mammalian core temperatures. Only a tiny proportion of fungal species can infect humans, and dangerous internal infections with fungi typically occur only in people with very weak immune systems.

Casadevall, a Bloomberg Distinguished Professor, warned in a paper in 2010 that global warming could trigger the emergence of many more fungal pathogens. In the new paper, he and his colleagues hypothesize that C. auris is the first of these.

Analyzing the temperature range for C. auris and a few dozen species that are its nearest fungal relatives, the scientists found that the new pathogen can grow at higher temperatures than most of these near-relatives, hinting that it may have acquired its thermal tolerance only recently. They also cited a previous finding from Casadevall's laboratory that some other fungal species in a large culture collection had begun to adapt to global warming by increasing their tolerance for higher temperatures.

Proving that global warming spurred the emergence of C. auris as a human pathogen will be difficult, but Casadevall and colleagues argue that this possibility--and the possibility that other new fungal pathogens will emerge--must be borne in mind as the global average temperature continues to rise.

"Right now fungal diseases are usually not reportable," Casadevall says. "So we need better surveillance of these infections in humans--and even in other mammals, where the first warnings of new fungal pathogens might occur."

C. auris strains usually have considerable resistance to antifungal drugs, and some resist all the usual treatments. How this resistance arose is another mystery--many scientists suspect that the widespread agricultural use of fungicides was the key factor. In any case, it underscores the need for better reporting of serious fungal infections and for new antifungal drugs, says Casadevall.
-end-
"On the Emergence of Candida auris: Climate Change, Azoles, Swamps, and Birds" was written by Arturo Casadevall, Dimitrios Kontoyiannis of the University of Texas MD Anderson Cancer Center, and Vincent Robert of the Westerdijk Fungal Biodiversity Institute in the Netherlands.

Johns Hopkins University Bloomberg School of Public Health

Related Global Warming Articles:

Containing methane and its contribution to global warming
Methane is a gas that deserves more attention in the climate debate as it contributes to almost half of human-made global warming in the short-term.
Global warming and extinction risk
How can fossils predict the consequences of climate change? A German research team from Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), the Museum of Natural History Berlin and the Alfred Wegener Institute compared data from fossil and marine organisms living today to predict which groups of animals are most at risk from climate change.
Intensified global monsoon extreme rainfall signals global warming -- A study
A new study reveals significant associations between global warming and the observed intensification of extreme rainfall over the global monsoon region and its several subregions, including the southern part of South Africa, India, North America and the eastern part of the South America.
Global warming's impact on undernourishment
Global warming may increase undernutrition through the effects of heat exposure on people, according to a new study published this week in PLOS Medicine by Yuming Guo of Monash University, Australia, and colleagues.
Global warming will accelerate water cycle over global land monsoon regions
A new study provides a broader understanding on the redistribution of freshwater resources across the globe induced by future changes in the monsoon system.
Comparison of global climatologies confirms warming of the global ocean
A report describes the main features of the recently published World Ocean Experiment-Argo Global Hydrographic Climatology.
Six feet under, a new approach to global warming
A Washington State University researcher has found that one-fourth of the carbon held by soil is bound to minerals as far as six feet below the surface.
Can we limit global warming to 1.5 °C?
Efforts to combat climate change tend to focus on supply-side changes, such as shifting to renewable or cleaner energy.
Global warming: Worrying lessons from the past
56 million years ago, the Earth experienced an exceptional episode of global warming.
Global fisheries could still become more profitable despite global warming
Global commercial fish stocks could provide more food and profits in the future, despite warming seas, if adaptive management practices are implemented.
More Global Warming News and Global Warming Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Biology Of Sex
Original broadcast date: May 8, 2020. Many of us were taught biological sex is a question of female or male, XX or XY ... but it's far more complicated. This hour, TED speakers explore what determines our sex. Guests on the show include artist Emily Quinn, journalist Molly Webster, neuroscientist Lisa Mosconi, and structural biologist Karissa Sanbonmatsu.
Now Playing: Science for the People

#569 Facing Fear
What do you fear? I mean really fear? Well, ok, maybe right now that's tough. We're living in a new age and definition of fear. But what do we do about it? Eva Holland has faced her fears, including trauma and phobia. She lived to tell the tale and write a book: "Nerve: Adventures in the Science of Fear".
Now Playing: Radiolab

The Wubi Effect
When we think of China today, we think of a technological superpower. From Huweai and 5G to TikTok and viral social media, China is stride for stride with the United States in the world of computing. However, China's technological renaissance almost didn't happen. And for one very basic reason: The Chinese language, with its 70,000 plus characters, couldn't fit on a keyboard.  Today, we tell the story of Professor Wang Yongmin, a hard headed computer programmer who solved this puzzle and laid the foundation for the China we know today. This episode was reported and produced by Simon Adler with reporting assistance from Yang Yang. Special thanks to Martin Howard. You can view his renowned collection of typewriters at: antiquetypewriters.com Support Radiolab today at Radiolab.org/donate.