Cholera is a dangerous and very infectious disease that can be spread through water, feces and, apparently, soft-shelled turtles. In a study published this week in the journal American Society for Microbiology, researchers dipped these turtles in glowing cholera bacteria to figure out if they spread the disease.

Unfortunately, they do — which is bad news in China, where they’re considered a delicacy.

First, the researchers injected the cholera bacteria, Vibrio cholerae, with genes that made it glow. Next, they dipped the soft-shelled turtles in a solution that contained the glowing cholera.

The scientists then checked on the turtles every day for the next four days. By day one, they were already seeing light signals. By day four, the upper shell was glowing. The cholera bacteria definitely had no problem spreading on these animals.

But the scientists also wanted to know if the bacteria got inside the turtles since, after all, few people eat the turtle shell. So they made the turtles take the same glowing cholera bacteria, and euthanized them about three days later. After dissecting the animals, they found that their intestines (though, thankfully, nowhere else) had the glowing cholera bacteria in it.

Thankfully, there haven’t been too many cases of cholera in China — about 200 in the past ten years. But the strain of the disease spread by turtles is seen as an emerging problem, and cholera is still an issue worldwide, with the World Health Organization reporting 190,549 cases in 2014. Turtles aside, this method of using glowing bacteria could be used to study whether other animals, too, spread the disease, and just where in their bodies the cholera colonizes.