Salmonella love lettuce in bags

Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

More posts by Christiane Fux All content is checked by medical journalists.

It is well known that salmonella likes to romp around on poultry meat. But they appear to multiply much more strongly on packaged lettuce. The juice that comes out of the cut or squashed leaves also lets them rise to their peak.

Salad in bags is popular with the nutrition-conscious: When torn to pieces and pre-washed, it ends up directly on the plate. But the greenery is often not as healthy as hoped.

Explosive growth

Researchers at the University of Leicester have found that even a small amount of crushed leaves can cause salmonella bacteria to explode. The escaping juice caused the number of germs to skyrocket 2400 times compared to samples with intact leaves.

Stubborn germs

Amounts of juice corresponding to a 200th teaspoon were already sufficient for this effect. “This juice also helped the bacteria to adhere so tightly to the lettuce leaves that they could hardly be washed off,” says study leader Primrose Freestone. The germs were also more difficult to remove from dishes and work surfaces.

Increased danger

Even more worrying was the fact that the juice-fattened bacteria were found to be particularly aggressive. The researchers therefore recommend that packaged lettuce be consumed quickly regardless of the use-by date. This applies in particular after opening the bags, even if they are stored in the refrigerator.

Notifiable illness

Food poisoning with the pathogen Salmonella enteritidis is extremely unpleasant. Pathogens that have survived the acid bath in the stomach nest in the intestinal wall, where they release toxins.

Depending on the amount of bacteria ingested, they trigger the first symptoms five to 72 hours after salmonella poisoning: acute vomiting, diarrhea with severe abdominal cramps, fever and headache. Because of the high fluid loss, some patients suffer a collapse or even circulatory failure. Since salmonella is highly contagious and poisoning can be fatal in the worst case, salmonella poisoning is notifiable in Germany.

Source: Giannis Koukkidis et al .: "Salad leaf juices enhance Salmonella growth, fresh produce colonization and virulence", Published in Applied and Environmental Microbiology, November 18, 2016

Tags:  alcohol drugs gpp home remedies