Just wash it doesn’t cut it; new research shows how E. coli O157:H7 binds to fresh vegetables

Research presented today at the Society for General Microbiology’s Annual Meeting in Liverpool shows that the disease-causing E. coli O157:H7 interacts directly with plant cells, allowing it to anchor to the surface of a plant, where it can multiply.

cow.poop.spinachResearchers from the James Hutton Institute in Scotland have identified that E. coli O157:H7 uses whip-link structures on its surface known as flagella – typically used for bacterial motility – to penetrate the plant cell walls. The team showed that purified flagella were able to directly interact with lipid molecules found in the membranes of plant cells. E. coli bacteria lacking flagella were unable to bind to the plant cells.

Once attached, the E. coli are able to grow on, and colonize, the surface of the plant. At this point, they can be removed by washing, although the researchers showed that a small number of bacteria are able to invade inside the plant, where they become protected from washing. The group have shown that E. coli O157:H7 is able to colonise the roots of both spinach and lettuce.

Dr Nicola Holden, who led the research, says: “This work shows the fine detail of how the bacteria bind to plants. We think this mechanism is common to many foodborne bacteria and shows that they can exploit common factors found in both cow.poop2plants and animals to help them grow. Our long term aim is to better understand these interactions so we can reduce the risk of food-borne disease.”

The researchers believe that the E. coli O157:H7 bacteria use the same method of colonizing the surface of plants as they do when colonizing the intestines of animals. The work shows that these bacteria are not simply transported through the food chain in an inert manner, but are actively interacting with both plants and animals.

Lettuce likely cause of Arizona restaurant E. coli outbreak; same in Calif.

Lettuce was the likely cause of an E. coli outbreak that sickened 94 people eating at a southwest Valley Federico’s Mexican Food restaurant, according to a report released by the Maricopa County Department of Public Health.

The outbreak occurred between July18 and 31 at the Federico’s, 13132 W. Camelback Road near Litchfield Park.

According to the report, the specific source of the bacterial exposure is uncertain, but lettuce-skulllettuce is the most likely culprit.

“The lettuce could have been contaminated in the field from manure, or (from) contaminated irrigation water, during processing, transport, handling, or through improper storage,” the report states. “Improper lettuce washing and preparation at the restaurant may have contributed to the spread of disease. The restaurant corrected these processes and complied with all other recommendations and no new cases were identified, effectively ending the outbreak.”

In California, the investigation into the cluster of E. coli cases that sickened five Humboldt County residents — including county Supervisor Estelle Fennell — has been suspended, said public health director Susan Buckley of the county Department of Health and Human Services.

”We don’t have enough cases to identify a source,” Buckley said. “They occurred over a three-month period, and showed up sporadically since August.”

What made this cluster of cases unusual was that this particular strain of E. coli — known as O157:H7 — has not been reported anywhere else in California.

After interviewing the infected Humboldt residents, Buckley said that each individual ate leafy green lettuce before feeling symptoms.

Multistate outbreak of shiga toxin-producing Escherichia coli O157:H7 infections linked to ready-to-eat salads

The lettuce and leafy greens folks always say they have some sort of food safety plan and are usually quiet when there’s an outbreak. There’s an easy solution, make data public and market at retail.

But why do that when bromides fill the market need.

A total of 33 persons infected with the outbreak strain of STEC O157:H7 were reported lettuce.skull.norofrom four states.

The number of ill persons identified in each state was as follows: Arizona (1), California (28), Texas (1), and Washington (3)

32% of ill persons were hospitalized. Two ill persons developed hemolytic uremic syndrome (HUS), and no deaths were reported.

The STEC O157:H7 PFGE pattern combination in this outbreak was new to the PulseNet database.

Epidemiologic and traceback investigations conducted by local, state, and federal officials indicated that consumption of two ready-to-eat salads, Field Fresh Chopped Salad with Grilled Chicken and Mexicali Salad with Chili Lime Chicken, produced by Glass Onion Catering and sold at Trader Joe’s grocery store locations, was the likely source of this outbreak of STEC O157:H7 infections.

On November 10, 2013, Glass Onion Catering voluntarily recalled numerous ready-to-eat salads and sandwich wrap products that may be contaminated with STEC O157:H7.

 

643 sick in separate cyclospora outbreaks

In 2005, my aunt was part of a cyclospora outbreak linked to fresh basil that struck at least 300 in Florida.

Cyclospora is miserable, until a correct diagnosis comes along and cilantro.slugs.powell.10appropriate anti-parasitics prescribed.

But cyclospora outbreaks keep popping up, year after year.

The U.S. Food and Drug Administration and Centers for Disease Control and Prevention have concluded the 2013 outbreaks were at least two different sources: fresh cilantro grown in Puebla, Mexico, felled some of those in Texas, while salad mix supplied by Taylor Farms de Mexico, S. de R.L. de C.V.,   to Olive Garden and Red Lobster restaurants, both owned by Darden Restaurants, was linked to those sick in Iowa and Nebraska.

As of September 20, 2013, CDC has been notified of 643 cases of Cyclospora infection from 25 states:  Arkansas,  California, Connecticut, Florida, Georgia, Illinois, Iowa , Kansas, Louisiana, Masssachusetts, Michigan, Minnesota, Missouri, Nebraska , New Hampshire, New Jersey, New York (including New York City), Ohio, Pennsylvania, South Dakota, Tennessee, Texas , Virginia, Wisconsin , and Wyoming. 

Food safety culture and leafy green hacks

Ever since the E. coli O157:H7 outbreak linked to bagged spinach from California in 2006 killed four and sickened 200, the leafy green folks have begged for government inspection and flogged their apparent transparency.

Anyone who brags about having government inspection has nothing to brag lettuce_skull__e_coli__O145_1_story(1)about; see XL Foods in Canada from yesterday.

And why it took 29 outbreaks before something was publicly done to allegedly improve food safety conditions remains one of those unanswered mysteries.

But for their seven years of food safety investment – which has succeeded only in lowering the Sponge Bob cone of silence over any outbreak involving California leafy greens – the best these PR flunkies can do is respond to a week-old article about food safety culture by CNN’s Dr. Gupta with a link to their own website which shows … nothing.

The phrase food safety culture has certainly jumped the shark and is bandied about by people who have no idea. I’m fairly sure Chris Griffiths came up with the phrase in the early 2000s, I used it publicly at IAFP in Calgary in 2006, based on the cultural influence of my French professor wife, and Wal-Mart Frank wrote a book about it in 2009.

Now every hack uses it.

The leafy green folks claim the LGMA website “provides access to the food safety practices, the audit checklist and annual reports which provide inspection and citation data.”

No it doesn’t.

Not anything meaningful.

And these folks are now telling Washington that food safety programs should spongebob_oil_colbert_may3_10(3)(1)(1)(1)be based on what they’ve done.

Bullshit.

If the leafy Green Marketing Folks want to be truly transparent, they will make actual inspection data public for mere mortals to review, they will market microbial food safety at retail, and stop stonewalling every time there is an outbreak linked to leafy greens.

Like the E. coli O145 outbreak that sickened 30 people in New Brunswick (that’s in Canada) in 2012.

Or the E. coli O145 linked to Romaine lettuce that sickened some 50 people in Michigan and other states in 2010.

That lettuce was grown in Arizona, but they have also adopted the LGMA model.

And were silent during the outbreak.

A table of leafy green related outbreaks is available at http://bites.ksu.edu/leafy-greens-related-outbreaks.

Multistate outbreak of Escherichia coli O145 infections associated with Romaine lettuce consumption, 2010

03.jun.13

Journal of Food Protection, Number 6, June 2013, pp. 928-1108 , pp. 939-944(6)

Taylor, E.V.; Nguyen, T.A.; Machesky, K.D.; Koch, E.; Sotir, M.J.; Bohm, S.R.; Folster, J.P.; Bokanyi, R.; Kupper, A.; Bidol, S.A.; Emanuel, A.; Arends, K.D.; Johnson, S.A.; Dunn, J.; Stroika, S.; Patel, M.K.; Williams, I.

Non-O157 Shiga toxin-producing Escherichia coli (STEC) can cause severe illness, including hemolytic uremic syndrome (HUS). STEC O145 is the sixth most commonly reported non-O157 STEC in the United States, although outbreaks have been infrequent. In April and May 2010, we investigated a multistate outbreak of STEC O145 infection. Confirmed cases were STEC O145 infections with isolate pulsed-field gel electrophoresis patterns
indistinguishable from those of the outbreak strain. Probable cases were STEC O145 infections or HUS in persons who were epidemiologically linked. Case-control studies were conducted in Michigan and Ohio; food exposures were analyzed at the restaurant, menu, and ingredient level. Environmental inspections were conducted in implicated food establishments, and food samples were collected and tested. To characterize clinical findings associated with infections, we conducted a chart review for case patients who sought medical care. We identified 27 confirmed and 4 probable cases from five states. Of these, 14 (45%) were hospitalized, 3 (10%) developed HUS, and

none died. Among two case-control studies conducted, illness was significantly associated with consumption of shredded romaine lettuce in Michigan (odds ratio [OR] = undefined; 95% confidence interval [CI] = 1.6 to undefined) and Ohio (OR = 10.9; 95% CI = 3.1 to 40.5). Samples from an unopened bag of shredded romaine lettuce yielded the predominant outbreak strain. Of 15 case patients included in the chart review, 14 (93%) had diarrhea and abdominal cramps and 11 (73%) developed bloody diarrhea. This report documents the first foodborne outbreak of STEC O145 infections in the United States. Current surveillance efforts focus primarily on E. coli O157 infections; however, non-O157 STEC can cause similar disease and outbreaks, and efforts should be made to identify both O157 and non-O157 STEC infections. Providers should test all patients with bloody diarrhea for both non-O157 and O157 STEC.

foodsafetyinfosheet-5-6-10

Leafy greens cone of silence leads to Canadian lawsuit over E. coli

In a lawsuit filed late last week, attorneys allege that lettuce sold by California-based Tanimura & Antle led to a Canadian woman’s E. coli infection.

The family of a Canadian woman who allegedly died after eating E. coli-contaminated lettuce sold by California-based Tanimura & Antle filed a lawsuit against the company late last week in U.S. District Court for the Northern District lettuce.skull.noroof California (Case No. CV13-02140). The lawsuit was filed by Seattle-based Marler Clark and San Diego-based Gordon & Holmes.

According to the lawsuit, the Canadian Food Inspection Agency (CFIA) isolated E. coli O157:H7 from a sample of Tanimura & Antle Romaine lettuce and issued a “Health Hazard Alert” on August 17, 2012, warning the public not to consume “Wrapped Single Head Romaine”. The agency expanded its notice to include additional lettuce on August 20. The complaint alleges that Gail Bernacki, a Calgary, Alberta resident, consumed the Tanimura & Antle Romaine lettuce and fell ill with an E. coli O157:H7 infection in late August, 2012. The complaint states that Ms. Bernacki was hospitalized for several weeks and did not return to her baseline functional status despite extensive rehabilitation and hospitalization. She passed away on January 16, 2013. Attorneys allege that E. coli O157:H7 bacteria isolated from Ms. Bernacki’s stool during her acute E. coli illness was genetically indistinguishable from bacteria the CFIA had isolated from the Tanimura & Antle Romaine lettuce.

“Although growers of leafy greens have made huge strides in food safety since the E. coli outbreak of 2006, this case shows that there is more to do,” said Marler Clark managing partner, Bill Marler.

A table of leafy green outbreaks is available at http://bites.ksu.edu/leafy-greens-related-outbreaks.

Canadian family to sue Tanimura & Antle for Romaine lettuce E. coli death

Earlier this year, Matt McClure of the Calgary Herald wrote the faraway fields of California were the source last year of lettuce tainted with a potentially-fatal bacteria that sickened scores of Canadians in at least three outbreaks.

Media attention focused on a recent surge of 30 illnesses in the eastern half of the country linked to E. coli-tainted iceberg lettuce distributed to fast-food restaurants, and another outbreak last spring involving 23 Screen-Shot-2013-04-26-at-4.17.50-PM-191x300patients in New Brunswick and Quebec who ate bagged romaine lettuce that was laden with the bacteria.

But federal documents — not made public until Feb. 2013 — also show a Calgary senior was one of at least three patients who fell sick in a separate outbreak last summer that was also linked to tainted lettuce.

The 84-year-old woman — whom the Herald has agreed not to identify — died last month after being in and out of hospital for months following a severe infection from a strain of E. coli O157: H7 that was a genetic match to the bacteria found in a package of Tanimura and Antle brand lettuce.

“You assume the companies providing a product have all the controls in place to make sure it’s safe,” the woman’s daughter said.

“For our family, that assumption proved deadly.”

And now the family is suing, with the help of Bill Marler and friends (details at http://www.marlerblog.com/case-news/canadian-family-to-sue-tanimura-antle-for-romaine-lettuce-e-coli-death/#.UX8VqpWGQ5Q).

Tanimura and Antle did not respond to a request for an interview about its food safety program in Feb. and how its tainted shipment of lettuce to Canada last summer was only detected when a CFIA official took a random swab at an import facility in Winnipeg.

Leafy greens cone of slience.

A table of leafy green outbreaks is available at http://bites.ksu.edu/leafy-greens-related-outbreaks.

Produce safety, US and UAE versions

From Abu Dhabi to Akron, Ohio, people are worried about the safety of leafy greens – spinach, lettuce, rocket, whatever.

Gulf News reports that locally grown fresh salad vegetables in the UAE are, according to academics, contaminated by dangerous bacteria because of unhygienic farm practices and improper food handling from the farm to the table.

They also warned nearly 43 per cent of water wells in the country are contaminated with bacteria that exceed the standard level of safe lettuceconsumption, even for irrigation of crops.

“If there is a serious epidemic or outbreak of life-threatening gastrointestinal disease we will know the source, namely, the contaminated salad greens we are eating nearly every day,” said Dr Dennis J. Russell, professor of biology, department of biology, chemistry and environmental science at the American University of Sharjah.

Research over the past five years showed the presence of persistent coliform and E. coli contamination sequestered within the leaves of the locally grown popular fresh salad vegetable knows locally as jarjeer (ccientific name rocket/rocca) and other salad greens, Dr Russells told Gulf News.

‘All of the samples of jarjeer were found contaminated with E. coli and 100 per cent of the latest samples were also contaminated with large amounts of Salmonella. Tests of other locally grown greens show they too are contaminated with these bacteria, although to a lesser extent,” Dr Russell said.

Michael Doyle, director of the Center for Food Safety at the University of Georgia told the Daily Herald that a recent study released by the Centers for Disease Control and Prevention fingered produce as the leading cause of food poisoning in the U.S.

Doyle said the more cracks and grooves on the skin of a fruit or vegetable, the more easily bacteria can hide. Melons also have a neutral pH, so they offer a perfect growing environment for bacteria.

The problem of contaminated melons is often made worse by grocery stores that sell cut pieces, but often don’t store them in a cold enough lettuce.skull.e.coli.O145environment.

Doyle recalls walking into an upscale grocery store in South Carolina one summer, where a metal tank with ice in the bottom was filled with containers of cut melon. The bottom inch of the containers was inside the ice, leaving the majority of the melon in an environment warm enough for bacteria to multiply rapidly.

In the CDC’s new study, however, leafy greens like lettuce and spinach were revealed as the worst culprits for food poisoning in the study period, between 1998 and 2008.

Salad greens marked “washed and ready to eat” or “triple-washed” remain an area of debate among food safety experts.

Some experts contend that the triple-washing with chlorine that takes place during processing is enough to kill what bacteria can be killed, and advise against washing bagged greens because the risk of cross-contamination in the home kitchen is a greater concern.

Doyle says not to buy bagged greens at all. He advises buying whole heads of lettuce or greens, removing the outer surface layers where bacteria is most likely to be present, and then washing the greens under cold running water.

Doyle has conducted studies that show the cutting and bagging of lettuce in processing plants can actually trap bacteria inside the lettuce leaves, meaning that no amount of scrubbing or washing will ever get rid of the germs. If greens are cut before they are washed — as they commonly are during processing — the bacteria become internalized by the leaves, trapping the germs inside the produce.

As risky as bagged greens can be, Doyle said an even greater concern should be the consumption of raw sprouts like bean and alfalfa.

He believes the only reason they weren’t first on the list of illness-causing produce in the CDC study is that folks just don’t eat nearly as many of them as they do items like lettuce, tomatoes or melon.

He said sprouts, due to their high levels of contamination, should never be consumed raw.

26 sickened; woman shares survival story after E. coli outbreak linked to Calif. lettuce

Belle Bourque of Westville, Nova Scotia, spent almost a month in hospital with E. coli O157:H7 after eating lettuce at a restaurant over the holidays.

“You know, one minute you’re healthy, you’re living a normal life and then ‘boom,’ you’re dying.”

Belle Bourque.e.coli.lettuce.13She spent nearly a month in hospital as E. coli bacteria attacked her kidneys.

“I’m sure if it wasn’t for the good doctors and the good Lord and all the prayers, I wouldn’t be here.”

Bourque’s case was one of more than a dozen confirmed in Nova Scotia and New Brunswick, along with 13 in Ontario.

In early Jan. 2013, the Public Health Agency of Canada said the most probable cause of 26 confirmed E. coli O157:H7 illnesses in the Maritimes and Ontario was shredded lettuce grown in California and distributed by FreshPoint Inc. primarily to some KFC and KFC-Taco Bell restaurants.

The silence from the California Greens Marketing Agreement has been lettucedeafening.

A table of leafy green outbreaks is available at http://bites.ksu.edu/leafy-greens-related-outbreaks.

No one in the Bourque family has eaten lettuce since Belle fell ill, and they don’t plan to unless it comes out of their own garden.

Lettuce sickens, hacks hack; ‘leafy green marketing agreements set a bar, but it’s still too low’

Last week, Western Growers released food safety guidelines for the production, harvest and processing of fresh culinary herbs.

According to The Packer, in April 2011, the Food and Drug Administration urged the industry to take action to improve the safety of fresh cilantro. In response, Western Growers lettucestarted an initiative to develop commodity-specific guidelines for all fresh herbs as opposed to cilantro only.

Good.

But in the wake of the U.S. Centers for Disease Control study fingering produce as the biggest source of foodborne illness amongst known outbreaks, several groups decided this was an ideal moment to lecture consumers rather than explain the food safety challenges of fresh.

And none of them mentioned cantaloupe.

Bad.

ConAgra Foods, purveyors of peanut butter and pot pies that have poisoned hundreds of Americans, teamed with the Academy of Nutrition and Dietetics to tell Americans, rather than avoid certain foods, practice safe food handling at home instead.

My Food Safety Network apparently lives on at the University of Guelph, dispensing advice I never would have provided, because there is little evidence consumers can do much when it comes to fresh produce.

And then there’s the blandness of FightBac, which used the study to remind people, “Any day is a good day to share a reminder about the importance of checking food safety steps at home!”

I’m not even sure that’s a sentence.

Much better and more realistic is the effort by Matt McClure of the Calgary Herald, who wrote the faraway fields of California were the source last year of lettuce tainted with a potentially-fatal bacteria that sickened scores of Canadians in at least three outbreaks.

Media attention has focused on a recent surge of 30 illnesses in the eastern half of the country linked to E. coli-tainted iceberg lettuce distributed to fast-food restaurants, and another outbreak last spring
lettuce.tomato.skullinvolving 23 patients in New Brunswick and Quebec who ate bagged romaine lettuce that was laden with the bacteria.

But federal documents — not made public until now — also show a Calgary senior was one of at least three patients who fell sick in a separate outbreak last summer that was also linked to tainted lettuce.

The 84-year-old woman — whom the Herald has agreed not to identify — died last month after being in and out of hospital for months following a severe infection from a strain of E.coli O157: H7 that was a genetic match to the bacteria found in a package of Tanimura and Antle brand lettuce.

“You assume the companies providing a product have all the controls in place to make sure it’s safe,” the woman’s daughter said.

“For our family, that assumption proved deadly.”

The leafy greens marketing types remain under the Sponge Bob cone of silence.

Mansour Samadpour, a microbiologist and lab executive based in Washington, said illness statistics show that programs like California’s Leafy Green Marketing Agreement are failing to make salads safer.

More than 1,200 people around North America have fallen sick after eating the product in the half decade since the program was introduced, twice the number who became ill in the previous five-year period.

“The size and number of lettuce outbreaks in Canada during the last year suggest a serious situation, one that’s arguably worse than the recall of tainted beef from XL Foods,” Samadpour said.

“The leafy green marketing agreements set a bar, but it’s still too low.”

While some retailers like Costco require testing of their suppliers, Samadpour said some in the produce industry balk at the additional cost of about four cents a bag.

“The industry says we triple wash with chlorine but we know that’s not effective in killing bacteria if they are present in large numbers,” Michael Doyle said.

“I think we need to require a reliable regimen of testing of these bagged products, but the problem is it costs money.”

He said one large manufacturer had confessed to him recently it was cheaper to recall product found to be tainted than to have advanced food safety interventions at their processing plants.

Tanimura and Antle did not respond to a request for an interview about its food safety program and how its tainted shipment of lettuce to Canada last summer was only detected when a CFIA official took a random swab at an import facility in Winnipeg.

Leafy greens cone of slience.

A table of leafy green outbreaks is available at http://bites.ksu.edu/leafy-greens-related-outbreaks.

The abstract of the CDC report is below:

Each year, >9 million foodborne illnesses are estimated to be caused by major pathogens acquired in the United States. Preventing these illnesses is challenging because resources are limited and linking individual illnesses to a particular food is rarely possible except during an outbreak. We developed a method of attributing illnesses to food commodities that uses data from outbreaks associated with both simple and complex foods. Using data from outbreak-associated illnesses for 1998–2008, we estimated annual US foodborne illnesses, hospitalizations, and deaths attributable to each of 17 food commodities. We attributed 46% of illnesses to produce and found that more deaths were attributed to poultry than to any other commodity. To the extent that these estimates reflect the commodities causing all foodborne illness, they indicate that efforts are particularly needed to prevent contamination of produce and poultry. Methods to incorporate data from other sources are needed to improve attribution estimates for some commodities and agents.

http://wwwnc.cdc.gov/eid/article/19/3/11-1866_article.htm