Research has revealed an exciting new weapon in the fight against drug-resistant bacteria: ants.
Ever since Alexander Fleming witnessed the bacteria-killing power of penicillin in his laboratory, antibiotics have led to what some have called the “golden-age” of American medicine. Diagnoses of tuberculosis and pneumonia are no longer the death sentence they once were, and infections like staph and strep throat can be treated easily.
But antibiotics are losing their effectiveness. For decades, doctors have prescribed them at even the slightest hint of infection – even when bacteria wasn’t the infecting agent. Bacteria, in turn, has caught on, and has begun mutating antibiotic-resistant genes.
Antibiotic resistance has global leaders extremely concerned; UN Secretary General Ban Ki-moon, speaking at the first general assembly meeting on drug-resistant bacteria las week, called it a “fundamental threat to global health.”
So where do ants come in?
It turns out that some ants, like the leaf-cutter ants of the Amazon, use bacteria to defend their nests against fungi and microbes. These bacteria secrete chemicals that have particularly powerful antibiotic effects, and researchers are now preparing to test them in animals to determine their potential as medicines for humans.
Amazonian leaf-cutters are one of the few species of ant being examined for this new antibiotic. In fact, the only species that are useful to this study are those that farm fungi in the North and South American tropics.
“These ants forage for plant material, which they bring back to their nests and feed to a fungus,” said Professor Jon Clardy of Harvard Medical School. “The fungus breaks down the plant material and the ants feed on the fungus.”
Since plant material is hard to digest, the ants use this fungus to help break it down before consumption. The problem is that the “good” fungus isn’t the only kind that grows in the bowels of the ants’ nest, and when hostile fungi begin to spread, they use bacteria to kill it off.
“In turn, ants have developed defenses revealed as white patches on their bodies.” Clardy said. “They look as if they had been dipped in powdered sugar. These patches are made of bacteria which the ant stores on its body. Crucially, these bacteria produce powerful antibiotic and antifungal agents.”
Scientists estimate that this strategy developed in ants around 15 million years ago. With over 200 species of fungus-farming ants in existence today, it appears to be a highly successful evolutionary trick – one that researchers like Professor Jon Clardy are hoping to exploit in humans.