Gladiolin Could Help Fight Deadly Fungal Infections

Scientists have identified a little-known antibiotic made by bacteria that can disarm fungi behind life-threatening infections.

The finding is encouraging at a time when drug-resistant fungi are an increasingly serious global health concern.

"Fungal infections kill an estimated two million people worldwide each year, yet treatment options remain limited," explains Ana Traven, a molecular biologist at Monash University in Australia who led the study published in Current Biology.

"Modern medicine, from surgery and cancer treatment to organ transplantation and intensive care, depends on our ability to prevent and treat these life-threatening infections."

Traven's team has now identified an existing but obscure antibiotic that could offer help.

"There are no vaccines for fungal infections, and some of the antifungal medicines we do have can be highly toxic, highlighting the urgent need for new ways to prevent and treat these diseases," Traven says.

Candida albicans and dangerous fungal infections

Candida albicans is a yeast that generally lives harmlessly on and within our bodies without being noticed. On very rare occasions, however, it can become pathogenic.

It usually causes infection only in people who are already seriously ill, immunocompromised, or have risks such as major surgery or invasive medical devices.

C. albicans can alternate between a rounded yeast form, which may aid its spread, and thread-like hyphae, which can help it penetrate tissue. In its hyphal state, it releases a toxin known as candidalysin that damages human cells.

When C. albicans enters the bloodstream, causing a condition known as candidemia, it can produce a life-threatening infection.

Meanwhile, the antifungal medicines once used to treat it are increasingly failing to work as effectively as before.

A recently identified antibiotic, gladiolin, shifted the fungus from invasive hyphae back into yeast cells - at least in laboratory Petri-dish experiments.

Gladiolin speeds up the shift from hyphae back to yeast cells. (Bharathwaj et al., *Curr. Biol., 2026)*

Gladiolin: a bacterial antibiotic against Candida albicans

Many of the most effective antibiotics available to us were, in a sense, borrowed from nature. Gladiolin is another example.

First identified in 2017, gladiolin is made by the bacterium Burkholderia gladioli. Like Candida, this bacterium can cause complications in hospital settings, although it is far less common.

Bacteria and fungi are not invariably peaceful neighbours: they often compete for the same resources.

A microbe's rival may therefore hold, in its genes, some of the most effective chemical weapons against it.

Since B. gladioli can endanger people - particularly in the same settings where C. albicans is also a concern - clinicians would not simply introduce the bacterium and wait to see which organism prevailed.

Instead, researchers have carefully extracted gladiolin from bacteria grown in the laboratory. The bacteria were originally isolated from the lung of a patient with cystic fibrosis.

Gladiolin has previously demonstrated promising activity against the bacteria responsible for tuberculosis. The latest results also build on research from 2024, which found that gladiolin can boost the action of the potent antifungal drug amphotericin B.

How gladiolin changes fungal behaviour

The new work details how this bacterial product affects C. albicans: it increases the activity of two crucial proteins, Tye7 and Gal4, driving the fungus's glucose metabolism into overdrive.

After C. albicans uses up its glucose supply, gladiolin causes it to return to its less invasive yeast form.

Combining gladiolin with amphotericin B produced a synergistic effect, suppressing C. albicans biofilms more strongly than either treatment did on its own.

"Our findings suggest that gladiolin could help existing drugs kill dangerous fungal pathogens, including drug-resistant biofilms that can form on medical devices, while potentially allowing lower, less toxic doses of antifungal drugs to be used," says Greg Challis, a molecular biologist at Monash.

Whether the treatment behaves similarly in the human body will not be known until it has first undergone a series of preclinical trials. Only then could it be given to people in clinical trials to assess its safety and effectiveness.

Related: Deadly Fungal Infections Causing a 'Silent Pandemic', Scientists Warn

"Fungal infections are often overlooked because they are not as common as bacterial infections," says pathologist Nathan Wiederhold of UT Health San Antonio, who did not participate in the gladiolin study.

"But they can be much more difficult to diagnose and treat, and we're seeing increasing spread and resistance."

All the help available will be needed, and gladiolin may form part of that effort.

The research was published in Current Biology.

This article was fact-checked and edited by Rebecca Dyer. Although we take pride in our process, we are only human. If you notice an error, please let us know.