Deadly Garden Fungus Found in US Soil and Compost

A dangerous, drug-resistant fungus called Aspergillus fumigatus has now been found in everyday gardening materials across the United States. Researchers are raising urgent concerns as this organism not only resists common antifungal drugs but also appears genetically primed to outsmart future medications (1^✔ ✔Trusted Source
Elevated mutation rates in multi-azole resistant Aspergillus fumigatus drive rapid evolution of antifungal resistance

Go to source). Scientists warn that the drug-resistant fungus is spreading rapidly across parts of the United States, especially in warm, humid states. Highly populated cities like New York and Los Angeles may also be at risk due to aging infrastructure and dense urban environments.

Why It Is Alarming:

A study from the University of Georgia found that 24 out of 525 samples of soil, compost, and flower bulbs tested positive for a drug-resistant strain of Aspergillus fumigatus, raising concern about its spread through everyday gardening materials. This fungus already causes over 300,000 infections a year worldwide, with death rates as high as 90 percent in vulnerable populations. A Nature Communications study now adds that some strains carry a specific mutation that increases mutation rates fivefold, meaning they could rapidly develop resistance to even new antifungal drugs in the future.

Where This Fungus Is Found

A. fumigatus is naturally present in compost, decaying leaves, and garden soil. It helps break down organic material, so it's virtually everywhere in the environment. That’s not a problem for most people. But in those with weakened immune systems, such as people with cancer, organ transplants, or chronic lung disease, this fungus can cause a severe lung infection called aspergillosis.

A Fungus That’s Evolving Fast

Researchers discovered that drug-resistant strains are not just more stubborn, they’re evolving faster. These strains carry a gene mutation known as msh6-G233A, which increases how often the fungus mutates, yet comes with no cost to its survival. That means the fungus continues spreading globally and adapting in ways that make it even harder to treat.

One alarming finding is that this gene variant tends to appear only in fungi already resistant to common azole drugs, which are heavily used in both medicine and agriculture. The combination makes this a “super-strain” with the potential to outpace medical treatment in hospitals and clinics.

Why Gardening Can Be Risky

Many people inhale fungal spores while gardening. Tasks like repotting plants or digging compost release spores into the air. For healthy individuals, the immune system quickly handles them. But immunocompromised people may not be able to fight off the infection, which can then spread from the lungs to the brain, kidneys, or skin.

Dr. Michael Mansour, an infectious disease expert at Massachusetts General Hospital, warns that many of his patients with aspergillosis had been exposed while gardening without masks or gloves. He says even short-term exposure can be risky in these cases.

How Agriculture May Be Worsening the Crisis

The rise of this dangerous fungus is closely linked to the widespread use of antifungals in farming. Just like antibiotics overused in livestock can breed resistant bacteria, fungicides sprayed on crops can help fungi evolve stronger forms that medical drugs can’t easily kill. This double use of antifungals in clinics and on farms is accelerating resistance worldwide.

What Experts Recommend

Do:

• Wear gloves and an N95 mask when handling soil, compost, or flower bulbs, especially if you have a weakened immune system
• Stay informed and alert if you or someone close is undergoing chemotherapy or has a lung condition

Don’t:

• Disturb compost or potting soil in enclosed spaces where spores can linger in the air
• Ignore persistent respiratory symptoms like coughing, wheezing, or fever after gardening

In healthcare settings, doctors are also on alert. With the rise of this highly adaptable strain, even next-generation antifungals may eventually fail. Prevention is key; especially for people already vulnerable to fungal infections.

The most alarming part of this discovery is not just that the fungus is already resistant to current treatments, but that it’s gaining the tools to resist future drugs too. And it’s doing so without slowing down or becoming less fit. That means it can continue spreading, silently and invisibly, through common gardening products and outdoor spaces.

If you or a loved one is immunocompromised, don’t skip the mask or gloves next time you garden. A hidden threat in the soil could be far more dangerous than it seems, and staying safe is as simple as protecting yourself before you dig.

Reference:

1. Elevated mutation rates in multi-azole resistant Aspergillus fumigatus drive rapid evolution of antifungal resistance - (https://www.nature.com/articles/s41467-024-54568-5)

Source-Medindia