Softshell turtles, a delicacy in China, may have something to do with potentially deadly cholera outbreaks in the country.
The cholera pathogen Vibrio cholerae can apparently invade the intestines of these turtles. Thus, there's evidence that these turtles, which people often eat, may be spreading cholera in China. Scientists say that turtles bred specifically for human consumption contain a major cholera strain.
Cholera is an infection that can cause symptoms ranging from nonexistent to severe. Symptoms include watery diarrhea that lasts a few days, and can lead to severe dehydration. Cholera spreads when human feces containing the pathogen contaminates food or drink. Places with poor sanitation or unclean drinking water are prone to cholera outbreaks.
Tourists in China often receive warnings to stay away from unsafe food or drink. Now, however, they must also avoid eating softshell turtles.
Researchers wanted to find out whether or not eating turtle delicacies will facilitate the spread of cholera. They were able to observe the pathogens colonizing the turtles by inserting genes that produce bioluminescent proteins into V. cholerae. The researchers then infected the turtles by dipping them in a special saline solution.
The next phase of the experiment entailed checking on the turtles every 24 hours for four days. By the end of those four days, the entire dorsal side of the turtle was bioluminescent. The researchers were also able to easily detect bioluminescence on the turtles' limbs and necks.
People consider a particular part of softshell turtles to be a delicacy. These turtles have a fatty, gelatinous material just beneath the surface of their shells. This part, called the calipash, also exhibited a considerable amount of bioluminescence. This means that the calipash, which people eat, as well as other parts of the turtle contain bacterial contamination.
The researchers also inoculated the turtles with the bioluminescent pathogen to study intestinal colonization. They dissected the turtles 72 hours after inoculation and discovered that only the intestines exhibited bioluminescence. Another discovery is how the pathogen was able to attach itself to the turtles' dorsal surfaces and intestines.
Cholera can be dangerous and deadly. China's Law of Infectious Disease Control and Prevention categorizes cholera under the most dangerous category, at par with plagues. Though China has seen less than 200 cholera cases over the last decade, it's still a disease that people need to be wary of. In other parts of the world, cholera has caused thousands of deaths and hundreds and thousands of infections.
The researchers say that the turtles are spreading an emerging strain of the infection. Thus, if you'll be traveling to China or are in China at present, try to avoid eating softshell turtles. It may be a rare delicacy, but it isn't worth risking contracting a potentially deadly disease. In China and elsewhere, travelers should be careful of what they eat and drink. As much as possible, make sure to drink only bottled water, and try to make sure that your food is prepared hygienically. This way, you can avoid contracting diseases like cholera.
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