Size matters: Fungus shrinks to better infect brain

Size matters: Fungus shrinks to better infect brain

Some fungi really are fun. Truffles, for instance, add a wonderful flavor to many meals and olive oils. Other types of fungus are more sinister, ranging from outright poisonous (looking at you, toadstools) to neurologically villainous, like Cryptococcus neoformans, the fungus behind fungal meningitis.

Those who have the misfortune of encountering C. neoformans can contend with rare but deadly brain swelling. The fungus is devious, but effective — undergoing a “remarkable transformation” that allows it not only to withstand different microenvironments in the body, but also to infect the body quickly.

Now, University of Utah scientists are studying its shrink-and-grow skill to better understand how we can block it.

If inhaled, the fungus can survive in the lungs and trot through the bloodstream into the brain and other essential organs. Like Alice in Wonderland, it changes size drastically: In the lungs, the fungus grows to 10 times its normal size. By the time it gets to the brain, it is exceptionally tiny.

According to the study, the fungus cells were unfazed by the body’s usual defense. Phosphate, a chemical released in the body when tissue is damaged by an infection, accumulates in the lungs at the first sign of fungus. Instead of being damaged, these fungus cells shape-shift and continue their march through the body. That led the researchers to wonder if the phosphate might have a role in inducing the fungus to alter itself.

This lethal efficacy has prompted researchers to turn their focus toward looking for an existing FDA-approved compound that can block the fungus from spreading throughout the body — catching it before it can transform.

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