A fungus described by the Centers for Disease Control and Protection (CDC) as a “serious threat to global health” has been found in several places in nature.
Candida auris it was first described in 2009 in Japan, before spreading to South Korea, Asia, Europe and the United States. The main challenges posed by the fungus – more specifically, a type of yeast – is that it is often resistant to various antifungals used to treat Candida infections. In addition, it is difficult to identify, can remain in the host for several months and can easily spread in hospital environments – especially where it has not been identified correctly.
In a new study, mycologist physician Anuradha Chowdhary, PhD, led a team that analyzed samples of soil, sand and water collected from beaches, swamps and mangroves on the tropical islands of Andaman. Even in samples taken from salt marshes, where human activity is low, the researchers found Candida auris – with one of the two samples proving susceptible to several antifungals.
Of more concern were the samples taken from areas such as the beach, where 22 samples contained the fungus – all resistant to multiple antifungals.
“The isolates found in the area where there was human activity were more related to strains that we see in the clinical setting,” said Chowdhary in a statement. Future studies, she said, may be able to explain this connection. “It can come from plants, or it can come off human skin, which we know C. auris can colonize. We need to explore more environmental niches for the pathogen. ”
The findings, write the authors in their study published in the journal mBio, represent the first time that the fungus was discovered outside a hospital environment. From the genetic tests of the samples, they believe that the fungus can survive well under certain conditions outside of human hosts.
“The high genetic diversity of C. albicans of old oaks shows that they can live in this environment for long periods of time “, wrote the team about the separate pathogenic yeast Candida albicans. “Likewise, the isolation of C. auris of the marine environment suggests swamps as a niche for C. auris outside its human host. “
An earlier hypothesis suggested that the fungus could be native to swamps and go unnoticed by humans before it became pathogenic for humans, when adaptations to higher temperatures caused by climate change made it thrive within us and in other mammals.
“The observation that an environmental isolate grew more slowly at mammalian temperatures than clinical strains is consistent with the notion that its ancestor has recently adapted to higher temperatures,” Dr. Arturo Casadevall, head of the Department of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health in Baltimore in a commentary article on the study.
“The knowledge that C. auris can be recovered from the environment should lead to further research to define its ecological niches, and the analysis of future environmental isolates will provide evidence to validate or refute the hypothesis of the emergence of global warming.”