Tag Archives: Produce

FDA speaks: E. coli O157 in leafy greens

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Between August and December 2020, the U.S. Food and Drug Administration (FDA) and multiple state and federal partners were involved in an outbreak investigation related to E. coli O157:H7 illnesses and the consumption of leafy greens. The outbreak, which caused 40 reported domestic illnesses, was linked via whole genome sequencing (WGS) and geography to outbreaks traced back to the California growing region associated with the consumption of leafy greens in 2019 and 2018. FDA, alongside state and federal partners, investigated the outbreak to identify potential contributing factors that may have led to leafy green contamination with E. coli O157:H7. The E. coli O157:H7 outbreak strain was identified in a cattle feces composite sample taken alongside a road approximately 1.3 miles upslope from a produce farm with multiple fields tied to the outbreaks by the traceback investigations. In addition, several potential contributing factors to the 2020 leafy greens outbreak were identified.

Isolates within this cluster of illnesses are part of a reoccurring strain of concern and are associated with outbreaks that have occurred in leafy greens each fall since 2017. The two most recent outbreaks associated with this strain were an outbreak in 2018 (linked to romaine lettuce from the Santa Maria growing region of California) and an outbreak in 2019 (linked to romaine lettuce from the Salinas growing region of California). Clinical isolates from cases in this 2020 outbreak appear more closely related to those from the 2019 outbreak than the 2018 outbreak. In addition, several specific food and environmental isolates that appear to be highly related to this 2020 outbreak include a fecal-soil composite sample collected by FDA in February 2020 from the Salinas growing region and two leafy green samples collected in 2019 by state partners as a part of the 2019 investigation that traced back to the Salinas growing region.

As part of this investigation, tracebacks of leafy greens consumed by ten ill individuals from eleven points of service were conducted. Although that traceback investigation was based on a relatively small number of the total cases, it was based on those cases which presented the strongest evidence via purchase card information, invoices, bills of lading, and electronic data. The traceback investigation identified the Salinas growing region of California as a geographical region of interest.

In light of this most recent finding, combined with previous outbreak investigation findings in the region, FDA has identified key trends regarding the issues of a reoccurring strain, a reoccurring region, and reoccurring issues around adjacent and nearby land use of primary importance in understanding the contamination of leafy greens by E. coli O157:H7 that occurred in 2020 and previous years.

FDA also recognizes the interconnection between people, animals, plants, and their shared environment when it comes to public health outcomes. As such, we strongly encourage collaboration among various groups in the broader agricultural community (i.e. livestock owners; leafy greens growers, state and federal government agencies, and academia) to address this issue. With this collaboration, the agricultural community, alongside academic and government partners, can work to identify and implement measures to prevent contamination of leafy greens. FDA recommends that these parties participate in efforts to understand and address the challenge of successful coexistence of various types of agricultural industries to ensure food safety and protect consumers against foodborne illnesses.

Frank Yiannas, Deputy Commissioner for Food Policy and Response – Food and Drug Administration said in a release that as part of our ongoing efforts to combat foodborne illness, today the U.S. Food and Drug Administration published a report on the investigation into the Fall 2020 outbreak of Shiga Toxin-Producing E. coli (STEC) O157:H7 illnesses linked to the consumption of leafy greens grown in the California Central Coast. The report describes findings from the investigation, as well as trends that are key to understanding leafy green outbreaks that are linked to the California Central Coast growing region, specifically encompassing the Salinas Valley and Santa Maria growing areas every fall since 2017.

We released our preliminary findings earlier this year that noted this investigation found the outbreak strain in a sample of cattle feces collected on a roadside about a mile upslope from a produce farm. This finding drew our attention once again to the role that cattle grazing on agricultural lands near leafy greens fields could have on increasing the risk of produce contamination, where contamination could be spread by water, wind or other means. In fact, the findings of foodborne illness outbreak investigations since 2013 suggest that a likely contributing factor for contamination of leafy greens has been the proximity of cattle. Cattle have been repeatedly demonstrated to be a persistent source of pathogenic E. coli, including E. coli O157:H7.

Considering this, we recommend that all growers be aware of and consider adjacent land use practices, especially as it relates to the presence of livestock, and the interface between farmland, rangeland and other agricultural areas, and conduct appropriate risk assessments and implement risk mitigation strategies, where appropriate. Increasing awareness around adjacent land use is one of the specific goals of the Leafy Greens Action Plan we released last March, which we’re also announcing is being updated today to include new activities for 2021.

During our analysis of outbreaks that have occurred each fall since 2017, we have determined there are three key trends in the contamination of leafy greens by E. coli O157:H7 in recent years: a reoccurring strain, reoccurring region and reoccurring issues with activities on adjacent land. The 2020 E. coli O157:H7 outbreak associated with leafy greens represents the latest in a repeated series of outbreaks associated with leafy greens that originated in the Central Coast of California (encompassing Salinas Valley and Santa Maria) growing region (that’s me and Frank and the woman who wants to divorce me in our Kansas kitchen, 10 years ago)

In the investigation, the FDA recommends that growers of leafy greens in the California Central Coast Growing Region consider this reoccurring E. coli strain a reasonably foreseeable hazard, and specifically of concern in the South Monterey County area of the Salinas Valley. It is important to note that farms covered by the Food Safety Modernization Act (FSMA) Produce Safety Rule are required to implement science and risk-based preventive measures in the rule, which includes practices that prevent the introduction of known or reasonably foreseeable hazards into or onto produce.

The FDA also recommends that the agricultural community in the California Central Coast growing region work to identify where this reoccurring strain of pathogenic E. coli is persisting and the likely routes of leafy green contamination with STEC. Specifically, we have outlined specific recommendations in our investigation report for growers in the California Central Coast leafy greens region. Those recommendations include participation in the California Longitudinal Study and the California Agricultural Neighbors workgroup. When pathogens are identified through microbiological surveys, pre-harvest or post-harvest testing, we recommend growers implement industry-led root cause analyses to determine how the contamination likely occurred and then implement appropriate prevention and verification measures.

In response, Tim York wrote in The Packer that on April 16 the California LGMA Board took decisive action to endorse pre-harvest testing guidance. The guidance recommends pre-harvest testing specifically when leafy greens are being farmed in proximity to animal operations. 

It’s the intention of the board to include pre-harvest testing as part of the LGMA audit checklist so the government can verify that all LGMA members are in compliance. 

This is the first time an entire commodity group will be required to conduct pre-harvest testing.

This is a big deal, but a necessary response to the recent U.S. Food and Drug Administration report on outbreaks associated with lettuce in 2020.  The findings and regulatory language used by FDA in this report were nothing short of a warning shot that calls on our industry to do more to stop outbreaks. 

And so, we must do more.

Updating LGMA’s required food safety practices is an involved process that seeks input from scientists, food safety experts and the public. No other entity is capable of making such widespread change as quickly as we can.<

Some weeks ago, in the first piece I wrote for The Packer as CEO of the California LGMA, I stressed the need for collaboration with the retail and foodservice buying community, noting that we must lean on each other to make needed improvements together. And now, I am asking for your help.

Updating LGMA’s required food safety practices is an involved process that seeks input from scientists, food safety experts and the public. No other entity is capable of making such widespread change as quickly as we can.

FDA, California agricultural stakeholders launch multi-year study to enhance food safety

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This is a few months old, but if Frank’s in it, I’ll run it, late but not never.

The following quote is attributed to Frank Yiannas, FDA Deputy Commissioner for Food Policy and Response:

“The FDA is committed to providing innovative food safety approaches that build on past learnings and leverage the use of new information and data. Today we’re announcing a partnership with the California Department of Food and Agriculture (CDFA), the University of California, Davis, Western Center for Food Safety (WCFS), and agricultural stakeholders in the Central Coast of California to launch a multi-year longitudinal study to improve food safety through enhanced understanding of the ecology of human pathogens in the environment that may cause foodborne illness outbreaks.”

“The launch of this longitudinal study follows a series of E. coli O157:H7 outbreaks in recent years linked to California’s leafy greens production regions, particularly three outbreaks that occurred in Fall 2019. Due to the recurring nature of outbreaks associated with leafy greens, the FDA developed a commodity-specific action plan to advance work in three areas: prevention, response, and addressing knowledge gaps. We’ve already made great strides executing our 2020 Leafy Greens Shiga toxin-producing E. coli (STEC) Action Plan by engaging with state partners to implement new strategies for preventing outbreaks before they occur, collaborating with industry partners to assess and augment response efforts when an outbreak occurs, and analyzing past leafy greens outbreaks to identify areas of improvement important to enhance leafy greens safety.”

“In alignment with the FDA’s New Era of Smarter Food Safety initiative, the findings from this longitudinal study will contribute new knowledge on how various environmental factors may influence bacterial persistence and distribution in the region, and how those factors may impact the contamination of leafy greens.”

The California longitudinal multi-year study will examine how pathogens survive, move through the environment and possibly contaminate produce, through work with water quality, food safety, and agricultural experts from CDFA, the WCFS, representatives from various agriculture industries, and members of the leafy greens industry.

Produce and on-farm risk management

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Produce-associated foodborne disease outbreaks have increased worldwide highlighting the importance of proper implementation of risk management practices (RMP). We determined the relationship between environmental characteristics (i.e., physical resources) of produce farms and implementation of RMP.

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses principles, we identified 36 studies to include in our analysis. Most study data were collected through surveys administered to growers in developed countries. Quality assessment results showed that studies on this topic should be more rigorously conducted (e.g., powering sample sizes and training data collectors) to yield better quality evidence. Agricultural waters were the most common environmental characteristic assessed, with many farms using unsafe water sources. Hygiene aids (e.g., accessible handwashing facilities), were lacking across many farms. Animal intrusion RMP were the least commonly assessed environmental characteristic. Only one study tested the relationship between on-farm environmental characteristics and RMP implementation reporting a positive relationship between accessible handwashing and worker hygiene practices.

Grower knowledge and perception of RMP combined with cost and ease in carrying out RMP might influence the availability of physical resources for proper RMP implementation. These results can inform practical interventions aimed to increase adoption of RMP on produce farms.

The relationship between environmental characteristics and risk management practices on produce farms: A systematic literature review

Agriculture

Dilhani Nisansala Jayawardhana 1 , Loan Thi Thanh Cao 2 , Thomas A. Yeargin 3 , Kristen E. Gibson 3 and Angela M. Fraser 1,*

http://scholar.google.com/scholar_url?url=http://131.220.45.179/ojs/index.php/fsd/article/download/69/997&hl=en&sa=X&d=18011325979091000715&ei=tuDCX4itNMeQmgGTyImoAQ&scisig=AAGBfm27ulzPEdzdGJcb8pYgpudYPZZCbA&nossl=1&oi=scholaralrt&hist=5kxqCikAAAAJ:5428478285509672052:AAGBfm0um7xNxqfVpArKOWnp4NG6xAm5og&html=&cited-by=

The continuing prevalence of shiga-toxin producing E. coli in produce

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Chris Koger of The Packer writes the U.S. Centers for Disease Control and Prevention has added 16 more people to an E. coli outbreak investigation of unknown origin, bringing the total to 39. Cases have been reported in 18 states; there have been no deaths.

According to the CDC’s Nov. 23 update, “Of the 22 ill people interviewed to date, all reported eating a variety of leafy greens, like spinach (16), romaine lettuce (15), iceberg lettuce (12), and mixed bag lettuce (8). No single type or brand of leafy greens or other food item has been identified as the source of this outbreak. CDC is not advising people avoid any particular food at this time.

Dole Fresh Vegetables, Inc. is voluntarily recalling a limited number of cases of organic romaine hearts. The products being recalled are Dole™ Organic Romaine Hearts 3pk (UPC 0-71430-90061-1), combined English/French packaging, with Harvested-On dates of 10-23-20 and 10-26-20, and Wild Harvest Organic Romaine Hearts (UPC 7-11535-50201-2), with Harvested-On dates of 10-23-20 and 10-26-20.  The recall is being conducted due to a possible health risk from E. coli in the two products.  Dole Fresh Vegetables is coordinating closely with regulatory officials. No illnesses have been reported to date in association with the recall. 

Pathogenic E. coli can cause diarrhea, severe stomach cramps and vomiting.  Most people recover within a week, but some illnesses can last longer and can be more severe.

This precautionary recall notification is being issued due to an isolated instance in which a package of Dole™ Organic Romaine Hearts – 3pk yielded a positive result for pathogenic non-O157 E.coli STEC in a routine sample collected at a retail store by the Michigan Department of Agriculture and Rural Development. There is no indication at this time that this positive result is related to any illnesses nor consumer complaints and it is not associated with the strains connected to the ongoing outbreaks currently under regulatory investigation. 

Raw is risky: Why salads are the biggest source of food poisoning and what to do to avoid it

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Brian Adam of Intallght writes just over a year ago, the United States saw the largest outbreak of E. coli since 2006; affecting at least 98 people in more than 20 states. The origin wa bagged romaine lettuce. Unfortunately, this is not an isolated case. Vegetables and fresh fruit have become a real headache for food safety experts.

 Today in the United States, fresh vegetables are the largest source of food poisoning. In Europe, the figures are not so pristine, but the bacteria and viruses associated with this type of food also are to blame for the vast majority of poisonings. We are facing a real danger for food safety: salads.

The numbers speak for themselves

In 1990, more than 400 epidemic outbreaks associated with fresh fruits and salads were detected. Between 2001 and 2013 we are not even able to know in its entirety, some experts explain, how many related outbreaks appeared, but they are many, increasing since 2008. Arrived in 2013, in Europe these epidemics seem to reduce their growth, stagnating in number per year, as explained in this article by EFSA, the European authority on food safety.

Despite the fact that Europe the number of appearances seems to have stabilized, in the United States they have continued to increase. The danger is still lurking, hidden between “romaine lettuce and Brussels sprouts.” The reason is in “cool” words.

According to some independent experts, this increase could be related to the increased consumption of vegetables and fresh fruit in the diet. This is a consequence of the search for a better, healthier diet. But, not being processed, these foods can also bring unexpected and unpleasant surprises.

But what is the problem? What’s wrong with fresh vegetables? It is not that strict food safety controls do not pass, as it happens with everything that arrives at our supermarkets but fresh food, especially if we put it in a plastic bag, is cannon fodder for microorganisms.

From the duh files: FDA says cows may have caused E. coli lettuce contamination, gumshoes are needed

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Lettuce and leafy greens are overrated.

Outbreaks of E. coli illness sickened 188 people last year who ate romaine lettuce in three separate outbreaks.

There have been so many outbreaks going back to spinach in 2006, and beyond that, my favorite salad now is a Greek  salad – without the lettuce.

If the Leafy Greens Marketing Association was as rigorous as its press releases maintain this would be minimized.

Instead, between 2009 and 2018, federal authorities identified 40 food-borne outbreaks of E. coli in the U.S. “with a confirmed or suspected link to leafy greens,” the FDA said.

Investigators concluded the most recent outbreaks were centered on ranches and fields owned by the same grower and that were located downslope from public land where cattle grazed.

So if LGMA is doing internal audits, why didn’t they notice this dude?

Because it’s PR not gumshoes, people out in the field.

We figured out 20 years ago that gumshoes are required.

 The U.S. Food and Drug Administration published the findings of an investigation into the contamination of romaine lettuce implicated in three outbreaks of E. coli O157:H7 during the Fall of 2019.

The investigation was conducted at several farms identified in the outbreak tracebacks, as well as at other businesses and public access areas and resulted in several key findings:

Each of these three outbreaks, identified in the report as Outbreaks A, B and C was caused by distinctly different strains of E. coli O157:H7 as determined by whole genome sequencing (WGS) analysis;

Traceback investigations of multiple illness sub-clusters and supply chain information identified a common grower with multiple ranches/fields which supplied romaine lettuce during the timeframe of interest to multiple business entities associated with all three outbreaks. 

The same strain of E. coli O157:H7 that caused Outbreak A was found in two different brands of fresh-cut salads containing romaine lettuce in 2019;

This same outbreak strain of E. coli O157:H7 in Outbreak A was detected in a fecal–soil composite sample taken from a cattle grate on public land less than two miles upslope from a produce farm with multiple fields tied to the outbreaks by the traceback investigations;

Other strains of Shiga toxin-producing E.coli (STEC), while not linked to any of the  outbreaks, were found in closer proximity to where romaine lettuce crops were grown, including two samples from a border area of a farm immediately next to cattle grazing land in the hills above leafy greens fields and two samples from on-farm water drainage basins.

These findings, together with the findings from earlier leafy greens outbreaks dating back to 2013, suggest that a potential contributing factor has been the proximity of cattle—a persistent source of E. coli O157:H7 and other STEC—to the produce fields identified in traceback investigations.

Because of  the reoccurring nature of outbreaks associated with leafy greens, the FDA recently released a 2020 Leafy Greens STEC Action Plan, which outlines a three-pronged approach for tackling this problem.  It describes the FDA’s plans for working with industry, federal partners, state and local regulators, academia and others to address the safety of leafy greens by advancing work in three areas: prevention, response, and addressing knowledge gaps.

Outbreak investigation of E. coli: Romaine from Salinas, California (November 2019)

21.may.20

FDA

https://www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-e-coli-romaine-salinas-california-november-2019

Salmonella in poop on produce

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Heightened concerns about wildlife on produce farms and possible introduction of pathogens to the food supply have resulted in required actions following intrusion events. The purpose of this study was to evaluate the survival of Salmonella in feces from cattle and various wild animals (feral pigs, waterfowl, deer, and raccoons) in California, Delaware, Florida, and Ohio.

Feces were inoculated with rifampin-resistant Salmonella enterica cocktails that included six serotypes: Typhimurium, Montevideo, Anatum, Javiana, Braenderup, and Newport (104 to 106 CFU/g). Fecal samples were stored at ambient temperature. Populations were enumerated for up to 1 year (364 days) by spread plating onto tryptic soy agar supplemented with rifampin. When no colonies were detected, samples were enriched. Colonies were banked on various sampling days based on availability of serotyping in each state. During the 364-day storage period, Salmonella populations decreased to ≤2.0 log CFU/g by day 84 in pig, waterfowl, and raccoon feces from all states. Salmonella populations in cattle and deer feces were 3.3 to 6.1 log CFU/g on day 336 or 364; however, in Ohio Salmonella was not detected after 120 days. Salmonella serotypes Anatum, Braenderup, and Javiana were the predominant serotypes throughout the storage period in all animal feces and states. Determination of appropriate risk mitigation strategies following animal intrusions can improve our understanding of pathogen survival in animal feces.

Survival of salmonella in various wild animal feces that may contaminate produce, 01 April 2020

Journal of Food Protection

Topalcengiz Z1,2, Spanninger PM3, Jeamsripong S4,5, Persad AK6,7, Buchanan RL8, Saha J2, LeJEUNE J7, Jay-Russell MT4,9, Kniel KE3, Danyluk MD2.

DOI:10.4315/0362-028X.JFP-19-302

https://www.ncbi.nlm.nih.gov/pubmed/32221570

(Oh, and I have a young lady who comes over every week for musical therapy, and we’ve been going through my greatest hits of the 1960s and 70s, so I just post whatever video I want now. Freedom of the press belongs to whoever owns one.)

Whittaker: Market food safety

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Ashley Nickle of The Packer wrote in Oct. 2019 (did I mention the bit about catch up, 8 broken ribs and a broken collarbone) PMA chief science and technology officer Bob Whitaker gave an impassioned presentation at Fresh Summit on the improvements that need to be made in food safety across the industry. Ten years after the formation of the Center for Produce Safety, companies can’t assert anymore that there isn’t relevant research to inform practices, Whitaker said.

Whitaker gave specific examples of potentially risky practices that are common. He mentioned setting harvest containers on the ground before they’re filled, and spoke about relying on the presence of generic E. coli in agricultural water to indicate pathogenic E. coli, along with several other examples.

Whitaker encourages companies to get competitive on food safety if that will get them to push past the status quo. He urged industry members to consider the costs when outbreaks happen, and he mentioned the death of a toddler during the 2006 outbreak linked to spinach.

“If we look at the recent issues we’ve had, we had an issue that involved water,” Whitaker said. “People said, ‘Well, we measured the water, we looked at generic E. coli.’ Well yeah, but the research has told us for years that generic E. coli does not represent the presence of pathogenic E. coli or salmonella. And In fact, at the volumes we do, we’re not going to find it.

“We also know that in every water system we’ve looked at around the U.S., I don’t care what crop, it has nothing to do with crop, every place the researchers have looked at and we’ve had a concentrated effort, we found contamination in open water sources — back east, out west, up north, doesn’t make a difference,” Whitaker said. “That’s where it is.”

Growing near concentrated animal feeding operations is another practice that the research indicates carries some risk.

“We know that dust will make the stuff travel,” Whitaker said. “Now we don’t know how far, but we know the one experiment that was done went out to 600 and it was there, so maybe it went farther …”

He also noted several practices in the field that he described as problematic yet commonplace.

“If I had a nickel for every picture I get every summer of people showing me Port-A-Johns being serviced in the field next to a harvest crop, I could have retired a couple years ago,” said Whitaker, who plans to retire from PMA in January.

“Don’t tell me it doesn’t drip, and then we wonder how we get some of these things like parasites in our fields,” Whitaker said.

He mentioned harvest sleds being left in the field overnight with the day’s debris still on them as another potential problem.

 “I’m seeing companies now breaking away from what everybody else is doing and say, ‘You know what, this is what we’re going to do,’” Whitaker said. “And we’ve always abhorred that idea. We’ve always said that food safety is something we share with each other, we don’t compete on it.

“To hell with that,” Whitaker said. “One thing this industry knows how to do is compete … You’ve always been marketing it anyway — you know you have. I see the stories. I see myself show up in people’s marketing things to their customers. I know that they’re marketing that.

“So do it,” Whitaker said. “If that’s what it’s going to take to get better, to create competition to get better, then do it. Because that’s what we need to do. We need the impetus to do it.”

Persister, I don’t even know her: STEC in produce

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Bacterial persistence is a form of phenotypic heterogeneity in which a subpopulation, persisters, has high tolerance to antibiotics and other stresses. Persisters of enteric pathogens may represent the subpopulations capable of surviving harsh environments and causing human infections. Here we examined the persister populations of several shiga toxin-producing Escherichia coli (STEC) outbreak strains under conditions relevant to leafy greens production.

The persister fraction of STEC in exponential-phase of culture varied greatly among the strains examined, ranging from 0.00003% to 0.0002% for O157:H7 strains to 0.06% and 0.08% for STEC O104:H4 strains. A much larger persister fraction (0.1–11.2%) was observed in STEC stationary cells grown in rich medium, which was comparable to the persister fractions in stationary cells grown in spinach lysates (0.6–3.6%). The highest persister fraction was measured in populations of cells incubated in field water (9.9–23.2%), in which no growth was detected for any of the STEC strains examined. Considering the high tolerance of persister cells to antimicrobial treatments and their ability to revert to normal cells, the presence of STEC persister cells in leafy greens production environments may pose a significant challenge in the development of effective control strategies to ensure the microbial safety of fresh vegetables.

Enhanced formation of shiga toxin-producing Escherichia coli persister variants in environments relevant to leafy greens production

Science Direct, Food Microbiology, Volume 84

Sandy Thao, Maria T. Brandl, Michelle Qiu Carter

https://www.sciencedirect.com/science/article/pii/S0740002018311353

Animals and produce-related risk: Australia New Zealand version

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The Fresh Produce Safety Centre of Australia and New Zealand came out with an 8-page fact sheet on the risks of animals to fresh produce that was seven pages too long.

Chapman used to write wonderful 1-page fact sheets that were used around the world, and maybe he can be persuaded to do so again, or find a skilled student.

The important graphic is below. The rest is filler.