The Infection Eaters

Marcin Filutowicz stumbled upon a potentially powerful biotherapy—using amoebas that feast on antibiotic-resistant bacteria to cure such ills as staph infections and diabetic ulcers

Is it safe to use amoebas this way?

In the literature, there is no reported evidence to support virulence of Dictyostelium discoideum, but obviously once we have a product ready for clinical trials, the FDA will scrutinize that. And keep in mind that amoebas are all around us in the environment—in the soil, in the air we breathe, on our food and in and on our bodies.

Amoebas are all around us in the environment—in the soil, in the air we breathe, on our food and in and on our bodies.

Are there other applications for this technology?

Yes, it’s just a matter of finding the right amoeba—or combination of amoebas—to combat a particular infection. Already, we have beautiful data showing that amoebas can eat Erwinia amylovora, the fire blight pathogen that infects orchards. We also have amoebas that can eat the bacteria that cause pneumonia.

Now we are starting to look at biofilms, which are thick aggregates of bacteria that are virtually impervious to antibiotics. Amoebas can eat biofilms, so they must produce something that dismantles biofilms and releases individual cells for them to access. One potential application for this is diabetic ulcers. The rise of diabetes in the United States is alarming, and one of the consequences of advanced diabetes is skin ulcers, which lead to amputations. The ulcers are incurable with antibiotics because they are seeded with biofilms. Currently, some doctors prescribe maggot therapy—where they apply maggots directly to the ulcer—as a treatment of last resort for this. That’s because the maggots “debride” the site, meaning they eat away the dead tissue, removing the bacterial biofilms as they go, which allows topical antibiotics to work.

When I came up with the idea for treating diabetic ulcers with amoebas, I talked to an infectious disease expert, and he said it would be a marvelous alternative to maggot debridement therapy. He would rather prescribe amoebas, which are too small to see, to his patients than have them witness maggots eating their flesh. So this could be huge application.

We’re also going to hunt for new kinds of antibiotics produced by Dictyostelium discoideum and other amoebas, as genome analyses indicate they have the capacity to make a lot of compounds that may function as antibiotics.