UK: Contaminated lettuce shows need for hygiene awareness
Most people seem to be well aware of similar risks when to comes to meat and poultry, but not with greens.
FSA chief scientist Andrew Wadge says: "Recent E.coli outbreaks linked with vegetables have shown that handling fresh produce can also spread harmful bacteria."
Yet the FSA’s research revealed public complacency. "Perceived risk of food poisoning from vegetables was low, whereas most people questioned were cautious when handling meat," Wadge says.
The UK newspaper, the Mail on Sunday, conducted its own investigation into food poisoning bacteria and found as many as one in twenty lettuces could be contaminated in high street supermarkets.
Lettuces were purchased on the high street and then taken to a food-testing laboratory and screened for Listeria monocytogenes and E.coli: both are strains of bacteria that can cause food poisoning if eaten.
Both strains are often present in agricultural settings, though the risk of contamination is minimal due to strict hygiene standards enforced on growers by the Department for Environment, Food and Rural Affairs.
"Bacteria are all around us in the environment," says Bob Martin, a microbiologist and food safety expert at the FSA. "E.coli contamination is normally associated with animal or human faeces, which could be present in soil where crops are grown or in water used to irrigate them. It can also result from poor personal hygiene among agricultural workers."
Listeria, an unavoidable environmental organism, lives on many plants, feeding on dead plant tissue.
"The lettuce we buy in the supermarket is a dead plant," says Christine Dodd, professor of food microbiology at the University of Nottingham. "If it contains listeria colonies, the longer you keep it, the more they’ll grow, even in the fridge and irrespective of the use-by date. So it’s best to buy vegetables with the longest shelf life and not to keep them for days before eating."
In the Mail's test, a reading of ten or less colony-forming units per gram (cfu/g) indicated a negative test for E.coli. According to the Institute of Food Science and Technology, the target level for E.coli in fresh veg is less than 100 cfu/g, with a maximum of 1,000 cfu/g. The Health Protection Agency says below 20 cfu/g in items sold as ready to eat is ‘satisfactory’; up to 100 cfu/g is ‘acceptable’.
Of the 120 lettuces tested, three were contaminated: 2.5 per cent, or one in 40. A Morrisons lettuce contained 20 cfu/g, while one from Waitrose contained 490 cfu/g. "The higher level here could cause sickness or an upset stomach in some people," says Phil Wheat, chief executive of the Society for Applied Microbiology.
Of the high E.coli reading, a Waitrose spokesperson comments: "While we strictly enforce the highest hygiene standards at all farms supplying us, we would always recommend people follow Government advice and wash all produce."
A spokesman for Morrisons said: "There’s nothing here to be concerned about but we recommend all customers follow the FSA’s recommendation that all lettuce be washed."
Listeria was not present in any of the samples.
Thankfully, outbreaks of harmful strains of E.coli are rare, but the FSA says it’s essential to thoroughly wash fruit and veg before eating them.
Source: dailymail.co.uk
