Last updated November 28, 2019 at 2:59 pm
Deadly fungal infections are on the rise, but researchers are fighting back, with an Australian team leading the charge.
An illustration of the Candida auris fungi. Credit: Kateryna Kon/Science Photo Library
Why This Matters: This is definitely not fun with fungi.
We typically associate fungi with mundane conditions like athlete’s foot. But some species can invade our bloodstream, kill immune cells and cause organ failure.
Despite the global rise of fungal infections, Monash University researcher Professor Ana Traven says they remain “underestimated”.
“People don’t tend to think about fungi as something that can kill you,” says Traven.
“At least a million, more like 1.5 million people, die every year from fungal infections globally.”
“It is a very significant problem.”
One of the really nasty fungi is Candida auris. First identified a decade ago, the fungus is often drug-resistant, deadly and has caused several intensive care units around the world to be shut down after they were contaminated.
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Candida can be deadly in people with lowered immune systems
Fortunately, C. auris is rare in Australia. But while more common species, such as its cousin Candida albicans, usually present little risk to healthy people, they can cause organ failure and death in critically ill patients and those who are immune-suppressed.
“In the example of Candida, infection is more of a problem in the developed world because they are hospital-associated infections, in the ICU and where people are really sick.”
Hospitals can be hotspots for fungal inspections. Credit: FS Productions
Intensive care units are a hotspot for fungal infections as critically ill patients can have feeding tubes and intravenous catheters inserted for extended periods of time. This gives the fungi an ideal site to colonise and thrive.
The fungi, often in conjunction with bacteria, can create a “biofilm”, a thin yet robust structure on a solid surface. Some components of biofilms can even impede the penetration of anti-fungal drugs.
“It’s highly resistant to therapy and a lot of the time, the only thing you can do is remove the device. That sounds like a simple thing but you have to keep in mind that these patients are very, very sick and it is not practical to be removing these devices,” says Traven.
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Infectious diseases physician Claire Dendle, from Monash Health, says fungal infections can also be deadly in cancer patients undergoing chemotherapy, organ transplant recipients taking anti-rejection drugs, and patients with HIV.
“Most patients who get what we call invasive fungal infections have problems with their immune system.”
“Their blood pressure drops; their organs start to fail. Sometimes they can have a rash but mostly they have fever and what we call sepsis,” explains Dendle.
“The thing about Candida and other fungi is there aren’t many antifungal drugs around. If it’s resistant to the most important class of drug, you are in real trouble.”
Indeed, Dendle says that C. auris is already resistant to many.
“One of the drug classes we normally use for Candida, it is resistant to. Secondly, it causes outbreaks; it spreads through contact of patients or contaminated surfaces. Thirdly, it has a high case fatality rate,” Dendle says.
The Australian team leading the charge
There are teams around the world working to find ways of tackling Candida fungi, however. One of the groups leading the charge is Traven’s own team at Monash.
Her group is attacking the problem from several angles – from how the fungi live and transform states, to identifying new drug targets and creating new diagnostic methods.
One question is how fungus out-competes the immune system to eventually cause organ failure. In a lab dish, Candida can kill immune cells called macrophages by triggering a cell death process. Last year, Traven’s group discovered Candida albicans can also kill immune cells by competing for an important resource.
“The Candida essentially starves the immune cells of glucose. Glucose is a critical nutrient for immune cells when they need to work, when they need to defend against microbes and cancer,” she says.
“As it often is in science, you find something you didn’t expect to find.”
Traven hopes this “understudied” global problem attracts more research funding and scientific talent.
“It is the most vulnerable people that these infections target and if we want to solve cancer and so on, we need to get on top of infections. It is a problem that feeds into a lot of other diseases.”
“It’s not going away. It’s really a problem of the 21st century.”
