All the news just repeats itself: Leafy greens in public

In October, 1996, a 16-month-old Denver girl drank Smoothie juice manufactured by Odwalla Inc. of Half Moon Bay, California. She died several weeks later; 64 others became ill in several western U.S. states and British Columbia after drinking the same juices, which contained unpasteurized apple cider — and E. coli O157:H7. Investigators believed that some of the apples used to make the cider might have been insufficiently washed after falling to the ground and coming into contact with deer feces (Powell and Leiss, 1997) not that washing would do much.

Almost 10 years later, on Sept. 14, 2006, the U.S. Food and Drug Administration announced that an outbreak of E. coli O157: H7 had killed a 77-year-old woman and sickened 49 others (United States Food and Drug Administration, 2006). The outbreak ultimately killed four and sickened at least 200 across the U.S. This was documented-outbreak 29 linked to leafy greens, but also apparently the tipping point for growers to finally get religion about commodity-wide food safety, following the way of their farmer friends in California, 10 years later.

In the decade between these two watershed outbreaks, almost 500 outbreaks of foodborne illness involving fresh produce were documented, publicized and led to some changes within the industry, yet what author Malcolm Gladwell would call a tipping point — “a point at which a slow gradual change becomes irreversible and then proceeds with gathering pace” — in public awareness about produce-associated risks) did not happen until the spinach E. coli O157:H7 outbreak in the fall of 2006. At what point did sufficient evidence exist to compel the fresh produce industry to embrace the kind of change the sector has heralded since 2007? And at what point will future evidence be deemed sufficient to initiate change within an industry?

The 1993 outbreak of E. coli O157:H7 associated with undercooked hamburgers at the Jack-in-the-Box fast food chain propelled microbial food safety to the forefront of public awareness, at least in the U.S. (Powell and Leiss, 1997). In 1996, following extensive public and political discussions about microbial food safety in meat, the focus shifted to fresh fruits and vegetables, following an outbreak of Cyclospora cayetanesis ultimately linked to Guatemalan raspberries that sickened 1,465 in 21 U.S. states and two Canadian provinces (U.S. Centers for Disease Control and Prevention, 1997). That same year, Beuchat (1996) published a review on pathogenic microorganisms in fresh fruits and vegetables and identified numerous pathways of contamination.

By 1997, researchers at CDC were stating that pathogens could contaminate at any point along the fresh produce food chain — at the farm, processing plant, transportation vehicle, retail store or foodservice operation and the home — and that by understanding where potential problems existed, it was possible to develop strategies to reduce risks of contamination (Tauxe et al., 1997). Researchers also reported that the use of pathogen-free water for washing would minimize risk of contamination (Suslow, 1997; Beuchat, 1998).

Beuchat and Ryu (1997) reported in a review that sources of pathogenic microorganisms for produce included:

Preharvest

  • Feces
  • Soil
  • Irrigation water
  • Water used to apply fungicides, insecticides
  • Green or inadequately composted manure
  • Air (dust)
  • Wild and domestic animals (including fowl and reptiles)
  • Insects
  • Human handling

Postharvest

  • Feces
  • Human handling (workers, consumers)
  • Harvesting equipment
  • Transport containers (field to packing shed)
  • Wild and domestic animals (including fowl and reptiles)
  • Insects
  • Air (dust)
  • Wash and rinse water
  • Sorting, packing, cutting, and further processing equipment
  • Ice
  • Transport vehicles
  • Improper storage (temperature, physical environment)
  • Improper packaging (including new packaging technologies)
  • Cross-contamination (other foods in storage, preparation, and display areas)
  • Improper display temperature.

kFresh fruits and vegetables were identified as the source of several outbreaks of foodborne illness in the early 1990s, especially leafy greens (Table 1).

Date Product Pathogen Cases Setting/dish State
Apr-92 Lettuce S. enteriditis 12 Salad VT
Jan-93 Lettuce S. Heidelberg 18 Restaurant MN
Jul-93 Lettuce Norovirus 285 Restaurant IL
Aug-93 Salad E. coli O157:H7 53 Salad Bar WA
Jul-93 Salad E. coli O157:H7 10 Unknown WA
Sep-94 Salad E. coli O157:H7 26 School TX
Jul-95 Lettuce E. coli O153:H48 74 Lettuce MT
Sep-95 Lettuce E. coli O153:H47 30 Scout Camp ME
Sep-95 Salad E. coli O157:H7 20 Ceasar Salad ID
Oct-95 Lettuce E. coli O153:H46 11 Salad OH
May-96 Lettuce E. coli O157:H10 61 Mesclun Mix ML
Jun-96 Lettuce E. coli O153:H49 7 Mesclun Mix NY

Outbreaks of foodborne illness related to leafy greens, 1992-1996.

Dave Gombas told an International Association for Food Protection symposium on leafy green safety on Oct. 6, 2006 in Washington, D.C. that if growers did everything they were supposed to do — in the form of good agricultural practices — and it was verified, there may be fewer outbreaks. He then said government needs to spend a lot more on research.

Wow. The same person who has vacillated between the Produce Marketing Association and the U.S. Food and Drug Administration for the past couple of decades (all you critics who complain about folks jumping back-and-forth-and-back as part of a genetically-engineered conspiracy may want to look at the all-natural, all-good-for-ya produce sector) pronounced on grower verification in which nothing has been done.

Since we were on the same panel in Washington, in 2006, I asked Gombas, why is the industry calling for more investment in research about the alleged unknowns of microbial contamination of produce when the real issue seems to be on-farm delivery and verification? Hiding behind the unknown is easy, working on verifying what is being done is much harder.

More calls for research.

Nothing on human behavior in a fresh produce environment.

It’s just another case of saying the right things in public, but failing to acknowledge what happens on individual farms. Verification is tough. Auditing may not work, because many of these outbreaks happened on third -party audited operations. Putting growers in a classroom doesn’t work, and there’s no evidence that begging for government oversight yields a product that results in fewer sick people.

In 1999, several more outbreaks of Shiga-toxin producing E. coli (STEC) were linked to leafy greens (Table 2), and the U.S. group, the United Fresh Fruit and Vegetable Association, developed and published HACCP-based food safety guidelines for industry (United Fresh Fruit and Vegetable Association, 1999).

Date Product Pathogen Cases Setting/dish State
Feb-99 Lettuce E. coli O157:H9 65 Restaurant NE
Jun-99 Salad E. coli O111:H8 58 Texas Camp TX
Sep-99 Lettuce E. coli O157:H11 6 Iceberg WA
Oct-99 Lettuce E. coli O157:H7 40 Nursing Home PA
Oct-99 Lettuce E. coli O157:H7 47 Restaurant OH
Oct-99 Salad E. coli O157:H7 5 Restaurant OR

Table 2. 1999 U.S. outbreaks of STEC linked to leafy greens

By 2000, Rafferty and colleagues demonstrated that E. coli could spread on-farm in plant production cuttings from one contaminated source, magnifying an outbreak to a whole farm (Rafferty et al., 2000). A 2001 outbreak of Shigella flexneri (886 ill) in tomatoes further focused public and scientific attention onto fresh produce.

Solomon and colleagues (2002a) discovered that the transmission of E. coli O157:H7 to lettuce was possible through both spray and drip irrigation. They also found that the pathogen persisted on the plants for 20 days following application and submerging the lettuce in a solution of 200ppm chlorine did not eliminate all viable E.coli O157:H7 cells, suggesting that irrigation water of unknown microbial quality should be avoided in lettuce production (Solomon et al., 2002a). In a follow-up experiment, Solomon and colleagues (2002b) explored the transmission of E. coli O157:H7 from manure-contaminated soil and irrigation water to lettuce plants. The researchers recovered viable cells from the inner tissues of the lettuce plants and found that the cells migrated to internal locations in plant tissue and were thus protected from the action of sanitizing agents. These experiments demonstrated that E. coli O157:H7 could enter the lettuce plant through the root system and migrate throughout the edible portion of the plant (Solomon et al., 2002b). Such results were widely reported in general media.

During this time, several outbreaks of E. coli were again linked to lettuce and salad (Table 3).

Date Product Pathogen Cases Setting/dish State
Oct-00 Salad E. coli O157:H7 6 Deli IN
Nov-01 Lettuce E. coli O157:H7 20 Restaurant TX
Jul-02 Lettuce E. coli O157:H8 55 Bagged, Tossed WA
Nov-02 Lettuce E. coli O157:H7 13 Restaurant IL
Dec-02 Lettuce E. coli O157:H7 3 Restaurant MN

Table 3: Leafy green outbreaks of STEC, 2000 — 2002.

 In 2003, according to Mexican growers, the market impact of an outbreak of hepatitis A traced to exported green onions lasted up to 4 months while prices fell 72 per cent (Calvin et al., 2004). Roma tomatoes were identified as the source of a salmonellosis outbreak that resulted in over 560 cases in both Canada and the US (CDC 2005).

During 2003-2005, several additional outbreaks of E. coli O157:H7 were linked to fresh leafy greens, including one multi-state outbreak involving Dole bagged lettuce (Table 4). 

Date Product Pathogen Cases Setting/dish State
Sep-03 Lettuce E. coli O157:H7 51 Restaurant CA
Nov-03 Spinach E. coli O157:H7 16 Nursing Home CA
Nov-04 Lettuce E. coli O157:H7 6 Restaurant NJ
Sep-05 Lettuce E. coli O157:H7 11 Dole, bagged Multiple

Table 4: Leafy green STEC outbreaks, 2003 — 2005.

During 2005–2006, four large multistate outbreaks of Salmonella infections associated with eating raw tomatoes at restaurants occurred in the U.S., resulting in 459 culture-confirmed cases of salmonellosis in 21 states. Investigations determined that the tomatoes had been supplied to restaurants either whole or precut from tomato fields in Florida, Ohio, and Virginia (CDC, 2006).

Allwood and colleagues (2004) examined 40 items of fresh produce taken from a retail setting in the U.S. that had been preprocessed (including cut, shredded, chopped or peeled) at or before the point of purchase. They found fecal contamination indicators (E. coli, F-specific coliphages, and noroviruses) were present in 48 per cent of samples.

 Researchers in Minnesota conducted a small-scale comparative study of organic versus conventionally grown produce. They found that while all samples were virtually free of pathogens, E. coli was 19 times more prevalent on produce acquired from the organic farms (Mukherjee et al., 2004). They estimated that this was due to the common use of manure aged for less than a year. Use of cattle manure was found to be of higher risk as E. coli was found 2.4 times more often on farms using it than other animal manures (Mukherjee et al., 2004).

On Sept. 14, 2006, the U.S. Food and Drug Administration (2006) issued a public statement warning against the consumption of bagged fresh spinach.

“Given the severity of this illness and the seriousness of the outbreak,” stated Dr. Robert Brackett, Director of FDA’s Center for Food Safety and Applied Nutrition (CFSAN), “FDA believes that a warning to consumers is needed (United States Food and Drug Administration, 2006).”

That is no different from the sometimes conflicting messages coming from FDA today about the E. coli O157:H7 outbreak on lettuce that originated in Yuma, Arizona: these public health folks are figuring it out on the go.

Sean Rossman of USA Today reports today that in the current E. coli O157:H7 outbreak linked to Yuma lettuce, 70% of those who’ve gotten sick are female.

Similarly, when leafy greens were the culprit of an E. coli outbreak last year, 67% of those infected were women or girls. In 2016, females were 73% of those ill from an outbreak in alfalfa sprouts, notes the U.S. Centers for Disease Control and Prevention.

Here are some suggestions:

  • The first line of defense is the farm, not the consumer.
  • All ruminants — cows, sheep, goats, deer — can carry dangerous E. coli like the O157:H7 strain that sickened people in the spinach outbreak, as well as the Taco Bell and Taco Johns outbreaks ultimately traced to lettuce.
  • Any commodity is only as good as its worst grower.

We’ve had a few peer-reviewed thoughts on these topics:

Powell, D.A. and Chapman, B. 2007. Fresh threat: what’s lurking in your salad bowl?. Journal of the Science of Food and Agriculture. 87: 1799-1801.

Implementing On-Farm Food Safety Programs in Fruit and Vegetable Cultivation, Improving the Safety of Fresh Fruit and Vegetables

Luedtke, A., Chapman, B. and Powell, D.A. 2003. Implementation and analysis of an on-farm food safety program for the production of greenhouse vegetables. Journal of Food Protection. 66:485-489.

Powell, D.A., Bobadilla-Ruiz, M., Whitfield, A. Griffiths, M.G.. and Luedtke, A. 2002. Development, implementation and analysis of an on-farm food safety program for the production of greenhouse vegetables in Ontario, Canada. Journal of Food Protection. 65: 918- 923.

A listing of 78 outbreaks linked to leafy greens since 1995 is posted here.

Risk is not low if cause is not known: 5, then 19, now 34 sick and 1 dead sick in E. coli outbreak linked to Edmonton restaurant

If the E. coli-romaine lettuce made it to an Alaskan prison, maybe it made it to an Edmonton restaurant.

Just asking.

According to the Toronto Star, one person has died and more than 30 people have fallen ill following an E. coli outbreak that Alberta Health Services has called “extremely complex” to investigate.

In a statement, AHS says it has expanded its investigation into the source of an outbreak of E. coli, beyond cases directly linked to an Edmonton restaurant late last month.

While 21 of these lab-confirmed cases are linked to Mama Nita’s Binalot restaurant in Edmonton, AHS no longer has public health concerns related to the restaurant.

The number of lab-confirmed cases of E. coli has increased to 34, including 11 patients who have needed hospital care, and one patient who has died likely due to E. coli infection.

“This outbreak is extremely complex, however AHS, in partnership with other provincial and federal agencies, is doing all we can to protect the health of Albertans,” said Dr. Chris Sikora, a medical officer of health in the Edmonton zone, in a statement. “The risk of illness remains very low.”

AHS has not yet identified the source of these cases, but believes they are linked to the initial outbreak.

The risk is not low if the cause is not known.

AHS has worked closely with the owners of Mama Nita’s Binalot since it was identified that a cluster of people with lab-confirmed E. coli ate at the restaurant. AHS says the owners have taken significant steps to manage this issue, including voluntarily closing until AHS was confident the restaurant could reopen without presenting a risk to the public.

Waiter, is that romaine from Yuma? At least 53 sick across 16 US states with outbreak strain of E. coli O157:H7 linked to lettuce

David Meyer of Fortune magazine reports the U.S.’s mysterious E. coli outbreak now has a likely culprit: romaine lettuce grown around Yuma, Arizona. And consumers are being given conflicting advice on what to do to protect themselves.

The Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) said Wednesday that any consumers in the U.S. who have store-bought chopped romaine lettuce should throw it away. If they want to buy romaine lettuce from now on, they should first check with the store or restaurant that it wasn’t grown in the Yuma region, the agencies said.

However, Consumer Reports has gone a step further, advising people to avoid all romaine lettuce for the time being. Why? Because people may find it difficult to establish for sure that their lettuce does not come from the growing region that’s suspected to be the source.

Niraj Chokshi of the New York Times reported that CDC said in a statement, “If you do not know if the lettuce is romaine, do not eat it and throw it away,” the C.D.C..

The agency was first alerted to the outbreak by health officials in New Jersey, who had noticed an increase in E. coli cases in the state, said Dr. Laura Gieraltowski, an epidemiologist at the C.D.C. After some discussion, it became clear that many of those infected had eaten chopped romaine lettuce at restaurants before getting sick.

Concerned, the agency looked for related cases by checking PulseNet, a national network of laboratories that catalog samples of harmful bacteria from infected patients.

“When we looked back into our PulseNet system we saw that there were other cases in other states with the same DNA fingerprint,” Dr. Gieraltowski said.

The C.D.C. learned that the others infected by that particular strain, E. coli O157:H7, had also eaten chopped romaine lettuce at restaurants before getting sick, she said. It turned over the information to the Food and Drug Administration, which helped trace the outbreak to Yuma, Ariz.

To pinpoint the exact source, though, investigators would need samples of the tainted lettuce. But because of the short shelf life of lettuce and the time it takes for an outbreak to be identified, obtaining such a sample may prove difficult.

However, a cluster of eight illnesses in an Alaska prison may help pinpoint the source.

Dr. Joe McLaughlin, with the Epidemiology Section at the state Department of Health and Social Services, said health officials had responded last week to an outbreak of E. coli O157:H7 bacteria at the Anvil Mountain Correctional Center in Nome, Alaska.

None of the eight patients have died or been hospitalized, in cases which were noticed between April 5 and April 15. All ate “significantly higher” numbers of salads than other people at Anvil Mountain, however, and have shown the same symptoms.

“Our outbreak is the first one I know of that’s been associated nationally with the consumption of whole heads of lettuce rather than chopped lettuce,” McLaughlin said. “What this outbreak suggests is that the source of contamination may actually be at the farm rather than the actual processing of the lettuce.”

Duh.

CDC reports in its latest outbreak update  that information collected to date indicates that chopped romaine lettuce from the Yuma, Arizona growing region could be contaminated with E. coli O157:H7 and could make people sick.

At this time, no common grower, supplier, distributor, or brand has been identified.

Consumers anywhere in the United States who have store-bought chopped romaine lettuce at home, including salads and salad mixes containing chopped romaine lettuce, should not eat it and should throw it away, even if some of it was eaten and no one has gotten sick. If you do not know if the lettuce is romaine, do not eat it and throw it away.

Before purchasing romaine lettuce at a grocery store or eating it at a restaurant, confirm with the store or restaurant that it is not chopped romaine lettuce from the Yuma, Arizona growing region. If you cannot confirm the source of the romaine lettuce, do not buy it or eat it.

Restaurants and retailers should ask their suppliers about the source of their chopped romaine lettuce.

Seek and ye shall find: Citrobacter in pre-cut veggies in a German hospital sickened 76

A foodborne outbreak of VIM carbapenemase-expressing Citrobacter freundii (CPC) occurred between February and June 2016 at a major university hospital in Germany.

An explosive increase of CPC isolated from rectal swabs of patients during weekly routine screening led to the declaration of an outbreak. A hospital-wide prevalence screening was initiated as well as screening of all patients on admission and before transfer to another ward, and canteen staff, patient rooms, medical and kitchen inventory and food. Swabs were streaked out on selective plates. All CPC isolates were analysed by mass spectrometry and selected isolates by whole-genome sequencing.

In total, 76 mostly unrelated cases in different wards were identified. The CPC was isolated from retained samples of prepared vegetable salads and puddings and from a mixing machine used to prepare them only after an overnight culture. The immediate ban on serving potential source food resulted in a sharp decline and finally disappearance of novel cases. Repeated testing of pre-sliced vegetables showed a high degree of contamination with C. freundii without a carbapenemase, indicating a possible source.

This report demonstrates that an explosive increase in carbapenemase-expressing Enterobacteriaceae contamination may be caused by a foodborne source, and suggests that pre-sliced vegetables have to be taken into account as a putative pathogen repository. It also underlines the importance of appropriate cooling, transport, re-heating and distribution of meals and indicates that probing of non-organic surfaces is limited by low sensitivity, which may be increased by additional overnight cultivation in appropriate media.

A nosocomial foodborne outbreak of a VIM carbapenemase-expressing Citrobacter freundii

15 January 2018

Clinical Infectious Diseases, https://doi.org/10.1093/cid/ciy034

Mathias Pletz, Antje Wollny, Ute-Heike Dobermann, Jurgen Rodel, Svetlana Neubauer, Claudia Stein, Christian Brandt, Anita Hartung, Alexander Mellmann, Sabine Edel, Vladimir Patchev, Oliwia Makarewicz, Jens Maschmann

https://academic.oup.com/cid/advance-article-abstract/doi/10.1093/cid/ciy034/4809943?redirectedFrom=PDF

Cilantro has a history of shits: Produce risk modelling in India

This study estimates illness (diarrhea) risks from fecal pathogens that can be transmitted via fecal-contaminated fresh produce. To do this, a quantitative microbial risk assessment (QMRA) framework was developed in National Capital Region, India based on bacterial indicator and pathogen data from fresh produce wash samples collected at local markets.

Produce wash samples were analyzed for fecal indicator bacteria (Escherichia coli, total Bacteroidales) and pathogens (Salmonella, Shiga-toxin producing E. coli (STEC), enterohemorrhagic E. coli (EHEC)). Based on the E. coli data and on literature values for Cryptosporidium and norovirus, the annual mean diarrhea risk posed by ingestion of fresh produce ranged from 18% in cucumbers to 59% in cilantro for E. coli O157:H7, and was <0.0001% for Cryptosporidium; for norovirus the risk was 11% for cucumbers and up to 46% for cilantro. The risks were drastically reduced, from 59% to 4% for E. coli O157:H7, and from 46% to 2% for norovirus for cilantro in post-harvest washing and disinfection scenario.

The present QMRA study revealed the potential hazards of eating raw produce and how post-harvest practices can reduce the risk of illness. The results may lead to better food safety surveillance systems and use of hygienic practices pre- and post-harvest.

Quantitative microbial risk assessment to estimate the risk of diarrheal diseases from fresh produce consumption in India

Food Microbiology, January 2018

Arti Kundu, Stefan Wuertz, Woutrina Smith

DOI: 10.1016/j.fm.2018.01.017 

http://www.x-mol.com/paper/530702

Confused consumers: Canadians say E. coli in romaine outbreak is over; U.S. says it’s leafy greens

Outbreaks of foodborne illness are fraught with uncertainties.

It’s OK to admit, to do the best with the info available, and get on with things.

On January 10, 2018, the Public Health Agency of Canada reported that an outbreak of Shiga toxin-producing E. coli O157:H7 infections (STEC O157:H7) they had identified was linked to romaine lettuce appears to be over.

As of January 10, 2018, there were 42 cases of E. coli O157 illness reported in five eastern provinces. Individuals became sick in November and early December 2017. Seventeen individuals were hospitalized. One individual died.

In the United States, the Centers for Disease Control, several states, and the U.S. Food and Drug Administration continue to investigate a multistate outbreak of 24 STEC O157:H7 infections in 15 states. Since CDC’s initial media statement on December 28, seven more illnesses have been added to this investigation. The last reported illness started on December 12, 2017.

The likely source of the outbreak in the United States appears to be leafy greens, but officials have not specifically identified a type of leafy greens eaten by people who became ill.  Leafy greens typically have a short shelf life, and since the last illness started a month ago, it is likely that contaminated leafy greens linked to this outbreak are no longer available for sale. Canada identified romaine lettuce as the source of illnesses there, but the source of the romaine lettuce or where it became contaminated is unknown.

Whole genome sequencing (WGS) showed that the STEC O157:H7 strain from ill people in the United States is closely related genetically to the STEC O157:H7 strain from ill people in Canada. WGS data alone are not sufficient to prove a link; health officials rely on other sources of data, such as interviews from ill people, to support the WGS link. This investigation is ongoing. Because CDC has not identified a specific type of leafy greens linked to the U.S. infections, and because of the short shelf life of leafy greens, CDC is not recommending that U.S. residents avoid any particular food at this time.

In the United States, a total of 24 STEC O157:H7 infections have been reported. Among the 18 ill people for whom CDC has information, nine were hospitalized, including one person in California who died. Two people developed hemolytic uremic syndrome, a type of kidney failure.

The Public Health Agency of Canada identified romaine lettuce as the source of the outbreak in Canada. In the United States, the likely source of the outbreak appears to be leafy greens, but health officials have not identified a specific type of leafy greens that sick people ate in common.

State and local public health officials continue to interview sick people in the United States to determine what they ate in the week before their illness started. Of 13 people interviewed, all 13 reported eating leafy greens. Five (56%) of nine ill people specifically reported eating romaine lettuce. This percentage was not significantly higher than results from a survey of healthy people in which 46% reported eating romaine lettuce in the week before they were interviewed.  Based on this information, U.S. health officials concluded that ill people in this outbreak were not more likely than healthy people to have eaten romaine lettuce.  Ill people also reported eating different types and brands of romaine lettuce. Currently, no common supplier, distributor, or retailer of leafy greens has been identified as a possible source of the outbreak. CDC continues to work with regulatory partners in several states, at the U.S. Food and Drug Administration, and the Canadian Food Inspection Agency to identify the source.

Although the most recent illness started on December 12, there is a delay between when someone gets sick and when the illness is reported to CDC. For STEC O157:H7 infections, this period can be two to three weeks. Holidays can increase this delay. Because of these reporting delays, more time is needed before CDC can say the outbreak in the United Stated is over. This investigation is ongoing.

Yup, they get into produce seeds, especially sprouts: Salmonella and E. coli internalization

Vegetable seeds contaminated with bacterial pathogens have been linked to fresh-produce-associated outbreaks of gastrointestinal infections. This study was undertaken to observe the physiological behavior of Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) cells artificially internalized into vegetable seeds during the germination process.

Surface-decontaminated seeds of alfalfa, fenugreek, lettuce, and tomato were vacuum-infiltrated with four individual strains of Salmonella or EHEC. Contaminated seeds were germinated at 25°C for 9 days, and different sprout/seedling tissues were microbiologically analyzed every other day. The internalization of Salmonella and EHEC cells into vegetable seeds was confirmed by the absence of pathogens in seed-rinsing water and the presence of pathogens in seed homogenates after post-internalization seed surface decontamination.

Results show that 317 (62%) and 343 (67%) of the 512 collected sprout/seedling tissue samples were positive for Salmonella and EHEC, respectively. The average Salmonella populations were significantly larger (P < 0.05) than the EHEC populations. Significantly larger Salmonella populations were recovered from the cotyledon and seed coat tissues, followed by the root tissues, but the mean EHEC populations from all sampled tissue sections were statistically similar, except in pre-germinated seeds. Three Salmonella and two EHEC strains had significantly larger cell populations on sprout/seedling tissues than other strains used in the study.

Salmonella and EHEC populations from fenugreek and alfalfa tissues were significantly larger than those from tomato and lettuce tissues. The study showed the fate of internalized human pathogens on germinating vegetable seeds and sprout/seedling tissues and emphasized the importance of using pathogen-free seeds for sprout production.

Fate of Salmonella enterica and Enterohemorrhagic Escherichia coli cells artificially internalized into vegetable seeds during germination

Appl. Environ. Microbiol. January 2018 84:e01888-17; Accepted manuscript posted online 27 October 2017, doi:10.1128/AEM.01888-17

Da Liu, Yue Cui, Ronald Walcott and Jinru Chen

http://aem.asm.org/content/84/1/e01888-17.abstract?etoc

 

 

21 sick with E. coli O157 from Romaine lettuce in Canada: What says LGMA?

The Sponge-Bob leafy greens cone of silence has once again been deployed with 21 sick from E. coli O157 linked to Romaine lettuce.

The Public Health Agency of Canada made the announcement Monday night, so it’s time for another edition of spokesthingy fairytales. The statements in italics are from the Public Health Agency of Canada. The comments below are mine.

The Public Health Agency of Canada is collaborating with provincial public health partners, the Canadian Food Inspection Agency and Health Canada.

How do you know a Canadian is making a presentation at a scientific conference? They spend half the talk noting collaborations.

At this time, there are no product recalls associated with this outbreak. The outbreak investigation is ongoing, and this public health notice will be updated on a regular basis as the investigation evolves.

We’ll see.

The risk to Canadians is low.

If you have no product recalls, no real clues other than some lettuce, how can you say the risk is low?

However, Canadians are reminded to follow safe food handling practices for lettuce to avoid becoming ill.

Washing does almost nothing to improve the safety of leafy greens, other than to remove the snot from an appropriately heightened 5-year-old and make consumers feel better.

Most people with an E. coli infection will become ill for a few days and then recover fully.

Unless you’re part of the percentage that has life-long health issues from eating a salad.

Some E. coli infections can be life threatening, though this is rare.

But it really sucks when it happens.

Currently, there are 21 cases of E. coli O157 illness under investigation in three provinces: Quebec (3), New Brunswick (5), and Newfoundland and Labrador (13).

These are not prime lettuce growing areas in Canada, in November.

Individuals became sick in November 2017. Ten individuals have been hospitalized.

No deaths have been reported.

See, no biggie. But this was issued Dec. 11. 2017. So was it early November or late November. The difference is hugely significant when assessing the timeliness of the announcement.

The Canadian Food Inspection Agency is working with public health officials to determine the source of the romaine lettuce that ill individuals were exposed to.
Which will be buried and vaguely released in some journal article a couple of years from now.
The following food safety tips for lettuce will help you reduce your risk of getting an E. coli infection.

  • Wash your hands thoroughly with warm water and soap for at least 20 seconds, before and after handling lettuce.

Water temperature doesn’t matter.

  • Discard outer leaves of fresh lettuce.
  • Wash your unpackaged lettuce under fresh, cool running water. There is no need to use anything other than water to wash lettuce. Washing it gently with water is as effective as using produce cleansers.

And neither are effective at removing pathogens.

  • Keep rinsing your lettuce until all of the dirt has been washed away.
  • Don’t soak lettuce in a sink full of water. It can become contaminated by bacteria in the sink.
  • Ready-to-eat lettuce products sold in sealed packages and labelled as washed, pre-washed or triple washed do not need to be washed again.
  • Use warm water and soap to thoroughly wash all utensils, countertops and cutting boards before and after handling lettuce to avoid cross-contamination.
  • Store lettuce in the refrigerator for up to seven days. Discard when leaves become wilted or brown.
  • Bagged, ready-to-eat, pre-washed lettuce products should also be refrigerated and used before the expiration date.

The Government of Canada is committed to food safety.

The Government of Canada is committed to creating a perception of commitment to food safety.

The Public Health Agency of Canada leads the human health investigation into an outbreak and is in regular contact with its federal and provincial partners to monitor the situation and to collaborate on steps to address the outbreak.

Thanks for the org-chart update.

This is nothing but crass industry-government-academia politico ass-covering.

At some point, the people barfing would probably appreciate something just a tad more human.

Cut means increased risk: 18 sick in Salmonella outbreak in Oregon, Washington linked to pre-cut fruit

Brad Schmidt of The Oregonian reports that 18 people in Washington and Oregon have been diagnosed with Salmonella after eating pre-cut fruit purchased from local grocery stores, prompting a review by state and federal health authorities.

Officials in both states have traced the outbreak to pre-cut watermelon, cantaloupe and fruit mixes containing those fruits. The products were purchased from Fred Meyer, QFC, Rosauers and Central Market.

Anyone who bought those products from those stores between Oct. 25 and Dec. 1 is urged to throw out the fruit.

“They should not eat it,” said Jonathan Modie, a spokesman for the Oregon Health Authority.

Just two of the 18 confirmed cases happened in Oregon, Modie said, with one in Multnomah County and one in Wasco County. Both people ate fruit purchased from Fred Meyer, he said, and the products carried Fred Meyer labels.

A spokesman for Fred Meyer, Jeffrey Temple, said the grocer pulled pre-cut watermelon and cantaloupe from store shelves in response to Friday’s advisory by the state of Washington.

Customers can return items to local stores for a full refund.

“Our highest priority is our customer’s safety and the safety of our food,” Temple said in a statement. “We will continue to work closely with state and federal health officials on their investigation to determine the source of this outbreak.” 

Uh-huh.

 

Hospitals should watch their litigation backside if growing their own produce with no safety talk

I’m not Debbie Downer, but I am Dougie Downer and never get invited to dinner.

This idea has risk written all over it.

Sarah Toy of USA Today writes that high atop the roof of a Boston hospital power plant in the middle of the city, you’ll find something unexpected: A 7,000-square-foot oasis with a lush carpet of green, rows upon rows of mesclun, kale, rainbow chard and a sea of plump green and red tomatoes.

Sounds good, has all the buzzwords except the one that I and anyone serving meals to immunocompromised people in hospitals should care about: microbiologically safe.

“There is an increasing trend in hospital farms,” said Stacia Clinton, the national program director for Health Care Without Harm’s Healthy Food in Health Care program, which advises hospitals on ways to provide sustainable and nutritious food. “There’s a greater demand now for people to know where their food is coming from, and hospitals are looking for ways to connect people to their food more directly.”

No mention of produce food safety.

If it’s growing on roofs, birds –Salmonella and Campylobacter factories – are crapping on the stuff, and washing does almost nothing.