Researchers have suggested that fungi are adapting to human body temperature and becoming drug-resistant, potentially due to climate change. This theory, however, is still contested. Every time you step outside, you inhale fungal spores, but out of the millions of fungal species, only about 20 cause infections in humans. (

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Published in the journal Nature Microbiology, recent research focuses on a previously unrecorded fungal species in human infections. Historically, fungal infections have been rare and mild, such as yeast infections, ringworm, and nail infections. However, unusual and severe fungal infections have increased, prompting deeper investigation into their behavior under changing climatic conditions.

In China, researchers examined fungal infection records from 98 hospitals between 2009 and 2019. They identified two patients infected with fungi that had never caused human disease before. In laboratory tests, these fungi infected immunocompromised mice, suggesting similar effects in humans with weakened immune systems.

Mammals are usually protected against fungi because our body temperature of 37°C is too high for most species to survive. However, the researchers found that the fungal species R. fluvialis and R. nylandii tolerated high body temperatures well. At 37°C, the rate of mutations in these fungi increased compared to 25°C, leading to resistance to antifungal medications.

"This paper shows that the same mechanism could exist in many other organisms that don't cause human disease, meaning they could adapt to cause human disease," said Jatin Vyas, a fungal pathogen specialist at Harvard Medical School. "It's not going to be like [the game/TV series] The Last of Us, but new fungal organisms could cause serious infectious diseases. And we have very few drugs to help," Vyas added.

The study's authors believe global warming is driving fungal pathogens to evolve drug resistance and virulence. "This is an indirect conclusion from the observations that heat tolerance is a known virulence," said Toni Gabaldón, an evolutionary biologist at the Institute for Research in Biomedicine in Barcelona, Spain. Other studies have shown that some fungal species can grow at higher temperatures than decades ago, but direct proof linking these observations is still needed.

There is a risk of drug-resistant fungal pathogens spreading globally, as detected in Spain, Portugal, and Canada. "We're starting to get nervous about what we're seeing. The vast majority of organisms are completely resistant to antifungal drugs," Vyas noted. Fungal infections already cause about 2.5 million deaths per year.

Reference:

1. Pan-drug resistance and hypervirulence in a human fungal pathogen are enabled by mutagenesis induced by mammalian body temperature - (https://www.nature.com/articles/s41564-024-01720-y)

Source-Medindia