A fungus described by the Centers for Disease Control and Protection (CDC) as a “serious global health threat” has been found in the wild in several locations.
Candida auris was first described in Japan in 2009, before spreading to South Korea, Asia, Europe and the US. The main challenges of the fungus – more specifically a type of yeast – is that it is often resistant to multiple antifungals used to Candida infections. In addition, it is difficult to identify, can remain in the host for several months, and can easily spread within hospital settings, especially if not properly identified.
In a new study, medical mycologist Anuradha Chowdhary, PhD, led a team that analyzed soil, sand, and water samples collected from beaches, swamps, and mangrove swamps in the tropical Andaman Islands. Even in the samples from salt marshes, where human activity is low, the researchers found Candida auris – wherein one of the two samples appears to be susceptible to multiple antifungal agents.
Even more worrying were samples taken from areas such as the beach, where 22 samples were found to contain the fungus – all of which were resistant to multiple antifungals.
“The isolates found in the area where human activity took place were more related to strains we see in the clinical setting,” Chowdhary said in a statement. Future studies, she said, may be able to explain that connection. “It could come from plants, or from human skin, as we know C. auris can colonize. We need to explore more environmental niches for the pathogen. ”
The findings, the authors write in their study published in the journal mBio, represent the first time the fungus has been discovered outside of a hospital setting. From genetic testing of the samples, they believe that the fungus can survive well outside of human hosts under certain conditions.
“The high genetic diversity of C. albicans of old oak trees shows that they can live in this environment for a longer period of time, “the team writes about the individual pathogenic yeast Candida albicans. Likewise, isolation from C. auris Marine environment suggests wetlands as a niche for C. auris outside of its human host. “
A previous hypothesis suggested that the fungus could be native to wetlands, and go unnoticed to humans before becoming pathonogenic to humans when adaptations to higher temperatures brought on by climate change allowed it to thrive in us and other mammals.
“The observation that one environmental isolate grew more slowly at mammalian temperatures than clinical strains is consistent with the idea that their ancestor has recently adapted to higher temperatures,” says Dr. Arturo Casadevall, chair of the Department of Molecular Microbiology and Immunology at Johns Hopkins Bloomberg School of Public Health in Baltimore, commented on the study.
“The knowledge that C. auris can be recovered from the environment should prompt additional searches to define its ecological niches, and the analysis of future environmental isolates will provide evidence to validate or disprove the global warming hypothesis. soil.”