A fatal hospital infection was discovered on a remote island beach. This is the first time that researchers have seen this multidrug-resistant organism in the wild.
The findings, published on Tuesday (March 16) in the journal mBio, may provide clues as to the origins of this excellent Candida auris, who mysteriously appeared in hospitals around the world about ten years ago.
“It’s a medical mystery, where does it come from,” said Dr. Arturo Casadevall, chair of the department of molecular microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health in Baltimore, said. He is writing an editorial accompanying the study. The new findings are a very important part of the puzzle, ‘Casadevall told WordsSideKick.
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C. auris is a fungus first discovered in 2009 in a patient in Japan. It looked fast spread all over the worldappearing on three different continents at the same time. The microbes can cause serious bloodstream infections, especially in patients who need catheters, feeding tubes or breathing tubes, according to the Centers for Disease Control and Prevention (CDC). The infections can be difficult to treat because the microbes are often resistant to multiple antifungal agents; and it can also linger on environmental surfaces. “When it comes to a hospital, it’s a nightmare” for infection control, Casadevall said. In 2019, the CDC declared C. auris an “urgent threat” to public health.
Although related species have been detected in plants and aquatic environments, C. auris are not found in natural environments. Casadevall and colleagues previously assumed that elevated temperatures due to climate change may have caused C. auris to adapt to higher temperatures in nature, thus enabling the fungus to make the leap to humans, whose normal body temperature is usually too hot for most fungi to survive.
The study’s lead author, Anuradha Chowdhary, a medical mycologist at the University of Delhi, India, and colleagues, inspired by this hypothesis, found samples of soil and water from eight locations around the Andaman Islands, a remote, tropical archipelago between India and Myanmar, has been collected.
The researchers isolated C. auris from two sites: a salt marshland where virtually no people ever go, and a beach with more human activity.
The C. auris The isolates from the beach were all resistant to many drugs and were more closely related to strains seen in hospitals, compared to the isolates found in the swamp, Chowdhary said in a statement.
One isolate found in the swamp was not drug resistant and grew more slowly at high temperatures compared to the other isolates. This finding suggests that this isolate may be a “wilder” strain of C. auris, one that has not yet adapted to the high body temperature of humans and other mammals, Casadevall said.
The study provides some support for the global warming hypothesis because it was first identified C. auris in a natural environment, which is a requirement for the hypothesis, the editorial said. In addition, the “wild” isolate can be a kind of missing link between game C. auris and those that cause infections in hospitals.
However, the study does not prove this C. auris live, of course, on the Andaman Islands, or that it originated there. It is possible that people could introduce the microbes, especially on the beach with more human activity. In addition, some researchers have questioned whether the microbes may have been carried by ocean currents from areas where human waste was dumped into the water, to the shores of the Andaman Islands, Casadevall said.
The new findings are likely to encourage more researchers to search C. auris in natural environments, and to compare wild tribes with those of hospitals, Casadevall said. Studies can also investigate whether wild C. auris isolates with less heat tolerance can develop in a laboratory environment to grow at higher temperatures, thus providing more support for the global warming hypothesis, the editorial said.
If it is indeed shown C. auris came from nature, and that global warming was a factor in the jump to humans, researchers are concerned that more pathogens could make the same leap. Many fungal organisms are harmful to insects and amphibians, but not to humans because of our high body temperature, Casadevall noted.
“If this idea is validated … we should start mapping more of these pathogens that are out there so that we do not get surprised,” as we were surprised by the new coronavirus, Casadevall said.
Originally published on Live Science.