Study on farmers' markets shows presence of Salmonella and E. coli

Researchers in Chapman University's Food Science Program and their collaborators at University of Washington have just published a study on the presence of Salmonella and E. coli on certain herbs sold at farmers' markets. The study focused on farmers' markets in Los Angeles and Orange counties in California, as well as in the Seattle, Washington, area. Specifically tested were samples of the herbs cilantro, basil and parsley. Of the 133 samples tested from 13 farmers' markets, 24.1 percent tested positive for E. coli and one sample tested positive for Salmonella.

"While farmers' markets can become certified to ensure that each farmer is actually growing the commodities being sold, food safety is not addressed as part of the certification process," said Rosalee Hellberg, Ph.D., and co-author on the study. "Certain herbs such as parsley, basil and cilantro have been implicated in many food outbreaks over the past two decades so our study focused specifically on the safety and quality of these three herbs."

Hellberg and her research team visited 49 different vendors at 13 farmers' markets in Los Angeles and Orange Counties in California, and in the greater Seattle area collecting 133 samples of the three herbs between the period of July and October 2013. Each sample was equivalent to one pound and was tested that same day for both Salmonella and E. coli using methods from the United States Food and Drug Administration Bacteriological Analytical Manual.

A total of 16 samples had average E. coli counts considered to be unsatisfactory according to guidelines established by the Public Health Laboratory Service. When tested for Salmonella, 15 samples had suspicious growth but only one tested positive—a parsley from a Los Angeles County farmers' market.

Orange County farmers' markets had the highest percentage of samples with E. coli growth followed by farmers' markets in the greater Seattle area and Los Angeles County.

Salmonella symptoms include diarrhea, abdominal cramps and fever around 12 to 72 hours after consumption that can last four to seven days. Symptoms for pathogenic forms of E. coli include severe stomach cramps, diarrhea that often becomes bloody, and vomiting.

According to the United States Department of Agriculture (USDA) Economic Research Service, farmers' markets have been increasing since 2009 near urban areas, particularly along the East and West Coasts. In August 2013, there were more than 8,000 ' markets listed in the USDA's National Farmers' Market directory.

The study was published in the Journal of the Science of Food and Agriculture.


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Citation: Study on farmers' markets shows presence of Salmonella and E. coli (2014, December 15) retrieved 19 October 2019 from https://phys.org/news/2014-12-farmers-presence-salmonella-coli.html
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Dec 16, 2014
Salmonella and E. coli are pathogens we have come into contact with on a regular basis for thousands if not millions of years. Unless we have a plan to eradicate them permanently, our current strategy of freaking out whenever we find them and avoiding them at all costs just breeds humans with no natural immunity to them.

As a civilization, we often wonder if some natural event could render humans extinct as has happened to the dinosaurs. I have always felt that our intelligence and adaptability would save at least a kernel of us from a similar event.

However, I am beginning to think that our tendency to rely on our rapidly advancing technology rather than natural selection to protect us from pathogens in our environment, leaves us extremely vulnerable to them in the event that some cataclysm rendered us incapable of maintaining our concurrent level of technology.

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