The antibiotic, which was extracted from a dirt sample, is unlike many antibiotics on the market today. It works by attacking the building blocks of a bacteria’s cell wall, making it difficult for the bacteria to evolve resistance.

The process of extracting teixobactin from the ground could open up a range of new treatment compounds that could fight superbugs such as staph, or tuberculosis infections, and even cancer, scientists say.

“Uncultured bacteria make up approximately 99% of all species in external environments, and are an untapped source of new antibiotics,” the researchers wrote in the journal Nature.

Now that scientists have developed a method for isolating and growing that uncultured bacteria, they’ve been able to develop several new ways to grow those organisms within a laboratory setting, allowing them to test the bacteria as possible new drug treatments. That’s what led to the development of teixobactin.

Studies on mice using the new antibiotic, which is the most promising candidate isolated from 10,000 strains scanned by the scientists, showed that it killed various kinds of staph and strep infections without any side effects. It even fought off a strain of staph that was drug-resistant.

That’s big news, especially given the looming threat of superbugs worldwide. Drug-resistant infections currently kill about 50,000 people each year in the U.S. and Europe, and that number could reach as high as 10 million deaths by 2050, according to research by the U.K. government.

Fighting superbugs has been a pharmaceutical treadmill, since “resistance development limits the useful lifespan of antibiotics and results in the requirement for a constant introduction of new compounds,” the researchers wrote. The search for new antibiotics is never over — at least, not until there’s a suitable mutation-stopping drug available.

Teixobactin works differently from most antibiotics we use today, many of which were developed decades ago. The antibiotic kills bacteria by blocking fatty molecules that help build cell walls, and so those fatty molecules are not as likely to mutate and make the infection drug-resistant.

Teixobactin shows a lot of promise, but it hasn’t yet been tested in humans. Its safety and effectiveness still needs to be determined before it will become available for common use. Studies in people won’t begin for about two years, meaning once it passes all required milestones, it could be five or six years until any drugs hit the market.

Even if teixobactin isn’t the ultimate solution, the new research points toward a new approach to how we develop antibiotics: search for drugs that not only kill bacteria, but also prevent mutation.