How raw green greens can hide dangerous superbugs: Experts warn "difficult to wash" vegetables as a salad is likely to spread antibiotic resistant bacteria
- Experts in California found that antibiotics did not protect mice from E. coli bugs  Bacteria were released into the body of lettuce leaves that are eaten raw
- Scientists said that people needed to know that these bacteria may not only be in meat
Raw leafy green vegetables as a salad are most likely to carry dangerous superbugas, scientists have warned.
Researchers found bacteria that are strong to survive antibiotic treatment could be transported on a salad.
Salad was of particular interest to the experts because the natural traces and folds in their leaves make it difficult to wash thoroughly.
And salad and other green vegetables are often eaten, which means that bacteria have not been killed by heat.
Antibiotic resistance has been designated as one of the foremost Threats to human health, and meat meat is considered an important cause.
Many animals are fed antibiotics when they are not even sick because they are getting bigger, but bacteria get used to the drugs.
But researchers from the University of Southern California say it's not just meat to be blamed, and vegetables can also play a role.
HOW SHOULD ANTIBIOTIC RESISTANT BACTERIA COME INTO OUR FOOD?
Antibiotic resistant bacteria are those that have been developed to be strong to survive treatment with previously effective drugs.
Exposure to antibiotics in small amounts or when there is no infection increases the risk of bacteria becoming accustomed to the medicine.
Farm animals kept to produce meat are sometimes fed antibiotics, many of which are the same as those used to treat humans, in order to make them faster.
In a natural environment, animals would be exposed to bacteria and then use energy to fight infection and build immunity.
Antibiotics remove the need for this immune response by killing bacteria immediately which means more of the animal's energy is used to make the body bigger. Therefore, the farmer gets more meat.
However, the bacteria become resistant to these antibiotics because they are constantly exposed to them, which means that the antibiotic-resistant bacteria – superbugs – are built up inside the animal.
These are then fed into the human food chain when the animals are slaughtered and sold as meat, or in the milk or if their manure is used to fertilize crops.
They added mutant strains of E. coli to release leaves and fed them to mice that had received antibiotic treatment for four days, New Scientist reported.
And E.coli could survive its passage through the body and colonize – take root and multiply – in the intestines of the mice despite antibiotics.
"We come across people who say they are vegetarians now they are safe," said lead researcher Marlene Maeusli.
"What we are trying to say is that everyone, whether you are a vegetarian, is still linked to the larger food chain."
According to the US Center for Disease Control and Prevention, two million people receive antibiotic resistant infections in the country every year and 230,000 dead.
And about 400,000 of these infections are thought to come from food – mostly meat.
Doctor Maeusli did not state where the bacteria could come from a real environment.
But previous research has suggested that they could pass on vegetables through soil fertilized with animal manure or from water used to irrigate crops.
Although these antibiotic-resistant bacteria cannot cause an immediate infection, if they are allowed to build up in the body, they can cause a worse and more difficult to treat disease further down the line.
"The environment and human health – in this context through agriculture and microbiomas – are inextricably linked," Maeusli said.
"Our findings highlight the importance of managing food-borne antibiotic resistance from a full food chain perspective that includes plant foods other than meat."
Maeusli and her team presented their research at the American Society for Microbiology Conference in California this weekend.