Researchers in Britain have carried out a study and found that pre-packed salads could lead to food poisoning as the green leafy vegetables often get contaminated by germs and some common bacteria like salmonella and E.coli.

According to them, the germs live in the guts of cows and the egg-ducts of chickens, and contamination of meat could happen during slaughtering. They can also spread to salads and vegetables fertilised with contaminated manure or via contact with contaminated products.

In fact, in their study, they found that salmonella can contaminate salads and vegetables by gripping the leaves with their flagella -- spiny propellers which the bacteria use to move, the Daily Mail reported.

Lead researcher Professor Gadi Frankel said: "In their efforts to eat healthily, people are eating more salad products -- choosing to buy organic brands and also preferring the ease of pre-washed bagged salads from supermarkets – than ever before.

"All of these factors, together with the globalisation of the food market, mean that cases of salmonella and E.coli poisoning caused by salads are likely to rise in the future. This is why it's important to get a head start with understanding how contamination occurs now."