This dangerous fungus has become resistant to every major antifungal drug available to us… twice: ScienceAlert

There’s a new fungus among us, and it’s causing concern among health experts because it’s resistant to all major antifungal treatments.

The discovery involves Candidozyma auris (formerly known as Candida auris)an emerging fungal pathogen that has already become a serious problem in hospitals around the world.

Since its first description in 2009, this fungus has spread to more than 60 countries on six continents, causing nosocomial outbreaks and invasive infections, with mortality rates of 30-50% reported in some situations.

The fungus can persist in healthcare environments and spread easily between patients. Due to its combination of antifungal resistance and potential for wider spread, the World Health Organization has designated C. auris a fungal pathogen of critical priority in 2022.

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But there’s something particularly troubling about the particular strain of this fungus described in a new paper: Lab tests found it to be resistant to all four major classes of antifungal drugs.

The isolate was recovered from a 28-year-old woman who developed a nosocomial surgical site infection after elective surgery at a hospital in Nairobi, Kenya. This is the first case of this type in Africa.

The swab from the woman’s wound ended up getting bigger C. aurisand genomic testing confirmed that the fungus belonged to one of the clades associated with high levels of antifungal resistance.

Researchers call this particular strain pan-drug resistant, or PDR, meaning it was resistant to antifungals found in familiar drugs like fluconazole, caspofungin, micafungin, amphotericin B, and flucytosine.

Pan-drug resistance like this is exceptionally rare. Researchers describe their Kenyan isolate as the first PDR C. auris identified in Africa and only the second documented case globally; another had already been reported in New York in 2022.

To better understand this resistance, the team sequenced its entire genome.

They discovered several mutations already associated with antifungal resistance, including changes in genes ERG11 And CDR1which are linked to resistance to azole drugs, alteration of FKS1 gene associated with resistance to echinocandins and a “stop-gain” mutation in FUR1a gene involved in processing the drug flucytosine.

The genetic profile of the strain may provide clues to the origin of its resistance.

The researchers note that the mutations differ from those found in strains previously reported in New York, raising the possibility that pan-drug resistance evolved independently rather than simply being imported to Kenya from the United States.

But it’s still possible.

They also cannot determine whether the patient’s prior exposure to antifungal drugs contributed to the selection of resistance. Her clinical history shows that she received several antifungal medications over the course of her illness, but researchers did not have enough information on doses and duration of treatment to determine whether these medications were driving the evolution of resistance in this particular infection.

The authors call this finding alarming, particularly in regions where access to new antifungal drugs may be limited.

The authors highlight the “increasing threat of incurable fungal infections” and call for stronger surveillance of fungal genomes, as well as “rapid diagnostic capacity to mitigate the spread of highly resistant fungal infections.” C. auris bloodlines in health care facilities,” as they write in the paper.

For now, the very resistant C. auris is super rare. But it has already demonstrated its ability to move around hospitals, acquire resistance and evolve in response to treatments.

A fungus that can survive almost any standard antifungal weapon reminds us that, in the microbial arms race, the enemy need not be common to be consequential.

The research was published in Scientific reports.