A deadly fungus can multiply by having sex, which could produce virulent strains that are more drug-resistant


Researchers at McMaster University have unlocked the evolutionary mystery of a deadly pathogen responsible for fueling the superbug crisis: it can reproduce by having sex.

And while such fraternization is infrequent, scientists report that it could produce more drug-resistant and virulent strains of virus. candida aurisable to spread faster.

C.auris is a fungus that can cause serious infections and sometimes death, often striking immunocompromised hospital patients.

Unlike animals and plants, microorganisms of this nature usually divide and reproduce asexually, so one produces two, two produces four and so on, all genetically identical to each other, through a process of division very simple and without exchange of genetic material.

“One of the really complex and confusing questions about this fungal pathogen is where it comes from and how it reproduces in nature,” says Jianping Xu, a professor in McMaster’s Department of Biology and a researcher at Canada’s Global Nexus for Pandemics and Pandemics. biological threats.

For the study, recently published online in Journal of Computational and Structural Biotechnologythe researchers analyzed nearly 1,300 strains available on a public database of C.auris genome sequences. They looked for and confirmed recombination events or sexual activity.

The results will help inform future research, as scientists can now replicate these sexual behaviors in the lab.

“Research tells us that this fungus has recombined in the past and can recombine in nature, allowing it to generate new genetic variants quite quickly,” Xu says. “It may sound scary, but it’s a double-edged sword. Because we’ve learned that they can recombine in nature, we could eventually replicate the process in the lab, which could allow us to understand genetic controls. virulence and drug resistance and potentially other traits that make it such a dangerous pathogen, much faster.”

C.auris was first discovered in 2009 and has since spread to more than 50 countries, where outbreaks have been reported and thousands of people have died from fungal infections.

In Canada, three of the five known divergent lines of C.auris were identified, some isolated from the same hospital.

Xu explains that if one strain becomes resistant to one drug and another strain becomes resistant to another drug, then through sexual activity they could produce offspring resistant to both drugs.

“The mixing of strains in the same hospital, potentially in the same patient, creates an opportunity for them to meet and mate,” he says. “This study is about sex, and the implication of sex on organisms is often very broad. For fungi, this means they can spread genes that benefit them much faster through populations than asexual reproduction alone. .”

In previous work, Xu and his collaborators at the University of Delhi had discovered drug-resistant strains of C.auris on the skin of two popular stored apple varieties, Royal Gala and Red Delicious, which had been treated with fungicides to extend their shelf life. The results of this study suggested that apples could be a pathway for yeast, helping it spread drug-resistant strains more widely.

This current research was funded by the Natural Sciences and Engineering Research Council of Canada and a grant from the Global Science Initiative of McMaster’s Faculty of Science.

Source of the story:

Materials provided by McMaster University. Original written by Michelle Donovan. Note: Content may be edited for style and length.


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