If a doctor has a patient infected with a fungus they don't recognize, there's a good chance the sample will end up in San Antonio. Nathan Wiederhold directs the Fungus Testing Laboratory at UT Health San Antonio, where his team routinely tests unidentified specimens sent in from across North America. "As a reference lab, we really see the unique things that a lot of people have not experienced or seen before," Wiederhold said.
Since taking over the lab in 2013, Wiederhold's team has identified at least 60 new fungal species. "These are things that have not been seen before causing disease in humans, and we were part of the team describing them; not only what they look like under the microscope, but also their DNA sequences, and then the disease they were causing in the individual."
Fungal pathogens have become a growing threat over the last 20 years, and many are resistant to the drugs doctors rely on. "That has put us in a bind with certain patients, because we've run out of treatment options," according to Wiederhold, who is also a professor in the Department of Pathology and Laboratory Medicine at the Joe R. and Teresa Lozano Long School of Medicine at The University of Texas at San Antonio. Candida auris is among the better-known drug-resistant fungi and can be lethal to people with compromised immune systems. Other emerging threats in the US include a dermatophyte that Wiederhold's lab flagged as developing antimicrobial resistance in 2022, and a new, sexually transmitted form of ringworm.
The Fungus Testing Laboratory doesn't just identify pathogens. It also plays a pivotal role in getting new antifungal medications to market. Researchers test new compounds against the lab's large sample library, and Wiederhold says one promising candidate is close to FDA approval. Once a drug reaches patients, his team keeps watch to see whether resistance develops against it, too.
"We're working with these compounds from the very start to when they're now being used in quite a number of patients," Wiederhold said. It's that full arc — from identifying the threat, then working to stay ahead of it — that makes his lab’s work both interesting and important. As he put it: "It's never a dull day in the fungus testing lab, and that's really a blessing.”
Science & Medicine is a collaboration between TPR and The University of Texas Health Science Center at San Antonio, about how scientific discovery in San Antonio advances the way medicine is practiced everywhere.
