The bacterium Alcaligenes faecalis was first discovered in faeces – but it turns out to have healing properties for the chronic wounds that affect people with diabetes.
An open wound is the perfect playground for bacteria – but some of these bacteria are actually helpful. Researchers found that Alcaligenes faecalis – named as such because it was originally discovered in faeces – promotes the healing of chronic wounds.
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| The bacterium Alcaligenes faecalis has unexpected wound-healing effects SciMAT /Science Photo Library |
In people with diabetes, the body’s carefully coordinated process of wound healing collapses, leading to chronic wounds that refuse to heal. These injuries are hard to treat, and they often cause painful infections that can lead to amputations or death.
Lindsay Kalan, a researcher previously in the lab of Elizabeth Grice at the University of Pennsylvania, was studying the microbiome of such wounds when she came across A. faecalis. At first, she and her colleagues thought it was just a “bystander” microbe that had no effect on the injury.
“But she found that, repeatedly, when she colonised wounds with this bacterium, that the wounds actually healed faster,” says Ellen White, also at the University of Pennsylvania. “That was a very surprising finding.”
White and her colleagues added A. faecalis to wounds on diabetic mice and to human skin samples from people with diabetes. In both cases, compared with untreated controls, the treated wounds and skin samples produced more, faster-moving keratinocytes – an important skin cell involved in wound closure.
Delving deeper, White and her colleagues found that the bacterium decreases levels of specific enzymes known to inhibit proper wound healing, called matrix metalloproteinases (MMPs). Levels of MMPs are higher in people with diabetes, so by rebalancing these enzymes, the bacterium may be restoring the diabetic wounds’ ability to heal.
Now, Grice’s lab aims to further understand the therapeutic potential of the bacterium – and to study how A. faecalis goes head to head with other bacteria in a wound, particularly dangerous ones like Staphylococcus aureus.
Swathi Balaji at Baylor College of Medicine in Texas says a lot more fundamental discovery is needed before this can be used as treatment, because chronic wounds contain a complex variety of bacteria that interact in different ways.
“If you target one thing, the pathogens will find a way to circumvent it again,” she says. “You have to tackle it from multiple different angles.”
Journal reference:
Science Advances DOI: 10.1126/sciadv.adj2020