Scientists in Singapore have discovered a new family member of a nightmare fungus. In new research this week, they detail finding a genetically distinct type of Candida auris in several patients of theirs—the sixth such type found to date. The fungus is one of the most feared superbug threats around, since it can resist multiple antifungals as well as spread quickly in hospitals and other hotspots.
C. auris was first discovered in 2009. While it usually colonizes healthy people without making them sick, it can also cause severe infections, particularly in people with weakened immune systems. These infections are often difficult to fend off, since the fungus can typically resist several or even all classes of antifungals available to treat it. It’s also hard to fully eradicate once established in an environment.
C. auris infections are still rare overall, but cases in the U.S. and elsewhere have grown substantially in recent years and the fungus has been steadily increasing its reach across more parts of the world. This new research, published last month in The Lancet Microbe, is the latest sign that C. auris has plenty more tricks up its sleeves.
Doctors from the Singapore General Hospital had come across a patient carrying a strain of C. auris in April 2023 as part of a routine screening program. In Singapore, these cases tend to originate from people who caught the infection somewhere else, but the patient reported no recent travel in the past two years, which intrigued the doctors. They teamed up with other researchers to analyze the strain’s genetics, finding that it didn’t quite match up with any of the five known groups—or clades—of the fungus already described by scientists. The team then went back and tested strains of C. auris taken from past hospital patients, finding two more cases that did match the genetic signature of their original case, as well as another sample collected from a patient in Bangladesh and uploaded to a public database by other scientists.
“We report the discovery of a proposed sixth major clade of C. auris which includes three epidemiologically unlinked isolates detected in Singapore, and one isolate reported from Bangladesh,” the researchers wrote. “We propose this new clade based on extensive genomic analysis showing the clustering of these four isolates, and great genetic distance from the five known clades.”
The silver lining to this discovery is that the hospital cases were all still treatable with conventional antifungals. But since these cases don’t appear to be connected to each other, it’s possible that this clade has already begun to spread silently in Singapore and possibly other parts of the world. We also don’t know if and how this version differs from other clades in its ability to cause human illness or large outbreaks. But given the increasing reports of outbreaks around the world, it’s clear that “C. auris continues to be a threat to public health,” the researchers wrote. And more needs to be done to ensure the timely surveillance and detection of this looming fungal menace.
