In China, diners consider soft-shelled turtles a delicacy. So when health officials found turtles infected with cholera bacteria in shipments throughout Asia, they were very alarmed.
Cholera is a dangerous infectious disease that can spread through water, so scientists took the only logical path to figure out what was happening:
They dipped sea turtles in glowing bacteria, of course.
To start, researchers injected the cholera bacteria with a gene to make it glow. Then, they dipped the turtles into a solution that contained the bacteria.
For the next four days, scientists checked the turtles daily. They saw light signals on day one; and by day four, the turtles’ shells were glowing.
What they were afraid of was true: The turtles were perfect vessels for the spread of cholera.
The scientists saw the glowing bacteria on the turtles' shell, head, neck and in the calipash — the gelatinous layer beneath the shell considered a delicacy in Asia.
Because people don’t generally eat most of those parts, though, scientists wanted to see if cholera also made its way into the turtles' bodies. They euthanized the turtles a few days after they ingested the bacteria.
Unfortunately, when scientists dissected the turtles, they found the bacteria in their intestines — though luckily, nowhere else.
This kind of bacteria, called vibrio bacteria, flourishes in salty estuaries and generally feeds on shellfish. It's not easily rinsed off, either, which may have led to the United States' last cholera outbreak in 1986. Experts blamed poor handling of raw shrimp, crabs and oysters.
Before you swear off eating anything from remotely near the ocean, know that there hasn’t been a cholera outbreak in China yet — there have only been about 200 cases in the last 10 years.
With outbreaks around the world, though, scientists are concerned that contaminated turtles could potentially cause a major problem in the future.
Scientists hope the dip-and-glow method, as we have just named it, could help them learn about other animals that may spread cholera — and hopefully prevent outbreaks, too.