Health

By Sveta Listratov • August 24, 2025

Jerusalem, 24 August, 2025 (TPS-IL) — A team of researchers from the Hebrew University of Jerusalem, in collaboration with the Institute of Microbiology at Friedrich Schiller University, has uncovered a surprising factor fueling the deadliness of fungal infections: viruses hidden inside the fungi themselves.

“These viruses are like molecular backseat drivers,” said Dr. Shlezinger. “They don’t cause disease on their own, but they influence how aggressively the fungus behaves once it’s inside the body.”

The study, led by Dr. Marina Campos Rocha, Dr. Vanda Lerer, PhD, and student John Adeoye under the supervision of Dr. Neta Shlezinger of the Koret School of Veterinary Medicine, found that a virus residing within the common fungus Aspergillus fumigatus boosts the pathogen’s resilience and virulence.

Aspergillus fumigatus is responsible for most invasive fungal infections in humans and is particularly dangerous for people with weakened immune systems. Mortality rates can reach nearly 50%. The new findings suggest that so-called “mycoviruses” act like hidden amplifiers, helping the fungus withstand stress, including the hostile environment of mammalian lungs.

When researchers removed the virus from fungal strains, the pathogen became significantly weaker—less able to reproduce, less resistant to stress, and far less lethal. Antiviral treatments also improved survival rates in animal models, hinting at a novel therapeutic pathway.

The study points to a potential paradigm shift: instead of targeting only the fungus, future treatments may aim at the viruses it carries—offering a new strategy against infections that are increasingly drug-resistant and difficult to treat.