Have you ever heard of yeast Candida aurisIf not then you probably aren’t the only one because you haven’t gotten a lot of attention.? It may change.
Candida auris The story begins in 2009 when a Japanese woman in her 70s is admitted to the Tokyo Metropolitan Hospital for the Elderly. Something may be secreted from her ears, and her doctor regularly uses cotton swabs to take samples. Analyze samples to determine the source of infection.
It turned out that it worked with a different yeast than any other known yeast.Baker’s yeast is a friendly microorganism used to make beer and bread. Candida auris Other Candida yeast species are very different. They cause serious and persistent infections that are difficult to treat with known antibiotics.
Outbreak in a London hospital
Against all expectations Candida auris It turned out to be unusually stress-resistant. This discovery is so unusual that doctors decided to document it in a scientific journal.they name it Candida auris Auris means ear in Latin, after where it was found. Since then, yeast has spread to all continents. Patients are most often weakened individuals, and incidents are almost always documented in hospitals.
For example, at the Royal Brompton Hospital in London, there was an uncontrollable acute illness. Candida auris The team tried everything to get rid of the infection for three months, eventually launching a week-long spray attack. They sprayed all surfaces in the infected room with hydrogen peroxide to ensure that the spray reached all crevices and corners.
A gel-coated plate was placed in the center of the room to test whether the microbes survived after running the spray apparatus for a week. Microbes that manage to withstand a week-long onslaught of the spray are attracted to the gel, revealing their presence. Only one organism is visible on the gel plate. Candida auris.
First case in Denmark
In 2022, a Danish man returned from South Africa and was admitted to a Danish hospital.A South African doctor discovered that the man had several wounds that needed to be treated. Candida auris on the patient’s skin.
The presence of the fungus on the skin is not itself dangerous – it only becomes dangerous if it gets into the bloodstream – but Danish hospitals Candida auris No other patients in the hospital were infected: The patient was admitted in two rooms to also have space for the equipment needed for testing. This eliminates the need to transfer patients to other departments.
Staff had to go through 2 keys to get to the 2 isolated rooms. The patient recovered and was discharged from the hospital, where the room and all locks were disinfected over the course of 24 hours.
4 cases so far in Denmark
The next patient, who was admitted to one of these two rooms, stayed only five hours, which was enough for the patient to become infected. Candida auris in bloodstream.
“It’s hard to understand how this could happen,” said Professor Miken Kabring Allendorp and head of the mycology unit at the Statens Serum Institute in Denmark, who followed the case.
4 cases so far Candida auris In Denmark, all have been registered since 2022. Three cases were on the skin of people returning from abroad, and a fourth was in a patient who became infected after five hours in a hospital room and had a blood infection. Both the carrier and the infected patient have recovered.
Need for better treatment
“The problem with this yeast is that it’s very difficult to kill. It’s multi-drug resistant, so there’s a risk of serious infections that can’t be treated,” says Daniel Wüstner’s research group, Department of Biochemistry and Molecular Biology. Maria Szomek said, adding:infections – including Candida aurisBut they are becoming less and less effective. Candida auris It is so good at developing resistance that the challenge now is to develop better drugs that are more effective. means a drug that kills “
existing drugs for Candida auris Other yeasts that can kill cells are often based on so-called polyenes. Polyenes are a group of substances found naturally in certain bacteria as part of their innate defense system. Polyenes can be extracted from bacteria for medical purposes.
Can nature’s own defense systems be improved?
But as Maria Szomek points out. The mechanism by which polyenes kill yeast is not well understood. However, this is essential for developing new and improved polyene-based drugs.
“So we are working to understand how natural polyenes work,” said Maria Szomek.
This work is done in Daniel Wüstner’s research group in the Department of Biochemistry and Molecular Biology. In their lab, the group uses advanced microscopy to study what happens to yeast cells when attacked by polyenes. The group has teamed up with colleagues in theoretical and computational chemistry Peter Reinhold and Jakob He Kongstedt, as well as his two German research teams at Leipzig and Humboldt Universities Berlin.
Precision attack inside the cell
Researchers Candida auris Use a harmless model instead and expose it to polyenes from the fungicide natamycin.
“We are interested in: How do polyenes cross cell membranes? How do they bind to ergosterol, a subgroup of steroids and the target of polyene attack? , do they interact with each other?
References: “Natamycin sequesters ergosterol and interferes with substrate transport by the lysine transporter Lyp1 from yeast” Maria Somek, Peter Reinhold, Hanna Loisa Walter, Holger A. Scheidt, Peter Müller, Sebastian Obermeyer, Bert Poolman, Jacob Kongstead, Daniel Wustner, 29 July 2022, Biochimica et Biophysica Acta (BBA) – biological membranes.
This research was funded by the Villum Foundation, the Lundbeck Foundation, and the Independent Research Fund Denmark.