Category Archives: E. coli

Probiotics as a means to improve the safety of cantoloupes

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A couple of weeks ago I was hit with a horrible case of strep throat. I was off from work for week, stuck in bed with a fever hovering around 40C. Naturally, the doctor prescribed some potent antibiotics which took care of the strep and essentially everything else. My naturopath prescribed probiotics to deal with the aftermath. A food safety researcher and his team from College of Agriculture, Health, and Natural Resources are looking at probiotics to improve the safety of cantoloupes.

Elaina Hancock reports

Just as probiotics can bring a wide range of benefits to your health, they can also make produce safer, according to new UConn research on cantaloupes.
This is good news, because the bumpy, net-like surface of a cantaloupe provides plenty of hiding places for bacteria to attach and weather the washing and disinfection steps in processing, allowing safe passage for pathogens to consumers’ plates.
This corrugated surface is likely the reason why cantaloupes have frequently hit the headlines in the past 10 to 15 years as the source of foodborne illness, says Professor Kumar Venkitanarayanan, a food safety specialist in the College of Agriculture, Health, and Natural Resources, who has been researching ways to improve the microbial safety of cantaloupes.
Chlorine is used as an industry standard for disinfecting fresh fruits and vegetables to improve safety and shelf-life of the food, says Venkitanarayanan. Chlorine is effective, but not 100 percent effective, especially in the case of cantaloupes.
In an earlier study on the efficacy of different chemical disinfectants for the tricky-to-clean cantaloupe, Venkitanarayanan and his team of researchers came across something surprising.
The experiments involved washing one group of cantaloupes with chlorine, and omitting the chlorine wash on another, then inoculating both groups with typical foodborne illness-causing bacteria, such as Salmonella or Listeria. Surprisingly, the results showed the pathogenic bacteria were more persistent on the surfaces of the cantaloupes that were treated with chlorine.
“Chlorine was not only not very effective at removing the pathogens, but maybe it removed the normal beneficial bacterial flora, the probiotics,” says Venkitanarayanan. Probiotics that may be keeping pathogenic bacteria from establishing themselves on the fruit.
Probiotics are used widely these days in hopes of improving various aspects of health, from digestion to depression, but they are also used in the prevention of plant disease and for improving soil health, and Venkitanarayanan says he became interested in applying these principles to food safety.
He and his research team set out to look at probiotics that have been used effectively as biosanitizers for the control of plant and soil pathogens. Settling on five to eight types of bacteria, they tested the abilities of these probiotics to prevent the growth of pathogenic bacteria on circular rinds of cantaloupe.
The researchers then inoculated the rinds with either the pathogen, the probiotics, or both. They simulated what would happen to the cantaloupe in the environment, by keeping the rinds at room temperature, as they would be in the field or in a store’s produce section.
“The results were that the probiotics worked very well,” says Venkitanarayanan says. “They were effective in reducing the pathogen, and the probiotics survived well on the surface.”
And the probiotics surpassed chlorine’s efficacy in disinfecting the surface of the cantaloupe.
In addition to the potential for avoiding the use of chemical disinfectants on produce, probiotics also bring environmental benefits.
“Chemical means of disinfection can be helpful, but we don’t know what long-term effects they have on the soil bacteria if disinfectants are applied pre-harvest,” says Venkitanarayanan. “With probiotics, we know they are helpful for the soil.”
Although the study itself was small, he says the results are paving the way for further studies into probiotic applications for food safety. For example, he notes that many of these same probiotics help prevent biofilm formation. This is a concern because Listeria, a common foodborne illness-causing bacteria, can form biofilms in processing plants.
Currently, the team are looking into different types of probiotics, experimenting with different mixes to find the most effective candidates for future studies. They are also looking at ways to ease the process of applying the probiotics.
“It is not easy to work with the whole cantaloupes,” Venkitanarayanan says. “It’s difficult to mimic the uniform application we get when working with the smaller rind discs. That is what we need to optimize now.”
Probiotic sprays for produce are not yet available for use at home, but to learn about other food safety practices you can implement now, visit the UConn College of Agriculture, Health, and Natural Resources’ Food Safety website.

 

Raw is risky: ‘Not aware this was remotely possible’ Father of toddlers critically sickened by E. coli linked to raw milk in Tenn.

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I started the Food Safety Network (the original FSN) as an incoming graduate student in 1993 in the wake of the Jack-in-the-Box outbreak, combining my science and journalism learnings, and because a constant refrain I observed was, I never knew foodborne illness could be so serious.

That’s why I continue to do it as a form of community service (I haven’t been paid since 2016).

There are now at least 15 children sick with E. coli in Tennessee that has now been linked to consumption of raw milk from French Broad Farm.

According to Kristi L Nelson of Knox News, Jordan and Stephanie Schiding wanted to give their children every health advantage.

That’s the reason the Schidings, two months ago, signed up for a local cow-share program after they read about the health benefits of unpasteurized milk.

Instead, 18-month-old Genevieve and 3-year-old Anthony contracted an illness caused by E. coli bacteria and ended up with kidney failure in the pediatric intensive care unit at East Tennessee Children’s Hospital — two of 12 local children hospitalized with E. coli since the end of May.

Knox County Health Department staff told the Schidings the E. coli infection was likely linked to the consumption of raw milk from French Broad Farm. On Thursday, the health department lifted its directive that requested French Broad Farm temporarily cease operations. But health department Director Dr. Martha Buchanan reiterated that consuming raw milk is always risky and health officials recommend the public consume only pasteurized milk and dairy products.

Jordan Schiding said he and his wife knew there was “potential” for food poisoning from unpasteurized milk, which both adults drank with seemingly no serious effects, but “we were definitely not aware that anything like this was remotely possible.”

The Schiding children seem to have turned a corner, he said, with Anthony discharged Friday afternoon and Genevieve still hospitalized but out of intensive care.

But what started as a supposed stomach bug May 31 turned into a terrifying experience that traumatized both the children and their parents, who had to watch them suffer.

Schiding said the family brought Genevieve to the emergency room at Children’s Hospital May 31 after she became seriously dehydrated with diarrhea and vomiting. As she was being admitted, Anthony also began vomiting.

The hospital rehydrated the children and discharged them a few hours later. Schiding believes they were among the first children related to the current cluster of E. coli cases to come to Children’s Hospital.

Two days later, after both children continued to get sicker, the Schidings brought them back to the hospital. This time, hospital staff took a stool sample from Genevieve, which tested positive for E. coli, and then from Anthony, who also tested positive. Both children were admitted, and Knox County Health Department contacted the couple the next day, he said.

The Schidings knew little about E. coli; certain strains produce a toxin, Shiga, that can cause a chain of reactions in the body — hemolytic uremic syndrome — resulting in clots in the small blood vessels in the kidneys that cause kidney failure. The very young, the very old and people whose immune systems are already compromised are more susceptible to HUS.

Four children admitted to Children’s so far have had HUS, including Genevieve and Anthony. Though Anthony wasn’t quite as sick as his sister, both had surgery to implant central lines so they could get fluids, dialysis and blood transfusions, Schiding said. Anthony had three days of dialysis, Genevieve seven.

In addition, Anthony’s central lines became infected with staph, Schiding said, but the antibiotics typically prescribed to treat staph are too hard on the kidneys to give a child with HUS, so doctors had to use a less common medication, which has seemed to work.

“Obviously, we were freaked out a little bit,” Schiding said. “It seemed like he had started turning the corner” until he spiked a fever of 104.9 and tested positive for staph.

Schiding said his family no longer will consume raw milk.

Shiga-toxin E. coli in dairy cattle near Brisbane

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Sure it’s almost 20 years old. But a reminder.

Over a 12-month period, 588 cattle faecal samples and 147 farm environmental samples from three dairy farms in southeast Queensland were examined for the presence of Shiga-toxigenic Escherichia coli (STEC). Samples were screened for Shiga toxin gene (stx) using PCR.

Samples positive for stx were filtered onto hydrophobic grid membrane filters and STEC identified and isolated using colony hybridisation with a stx-specific DNA probe. Serotyping was performed to identify serogroups commonly associated with human infection or enterohaemorrhagic Escherichia coli (EHEC). Shiga-toxigenic Escherichia coli were isolated from 16.7% of cattle faecal samples and 4.1% of environmental samples. Of cattle STEC isolates, 10.2% serotyped as E. coli O26:H11 and 11.2% serotyped as E. coli O157:H7, and the E. coli O26:H11 and E. coli O157:H7 prevalences in the cattle samples were 1.7 and 1.9%, respectively.

Prevalences for STEC and EHEC in dairy cattle faeces were similar to those derived in surveys within the northern and southern hemispheres. Calves at weaning were identified as the cattle group most likely to be shedding STEC, E. coli O26 or E. coli O157. In concurrence with previous studies, it appears that cattle, and in particular 1-14-week-old weanling calves, are the primary reservoir for STEC and EHEC on the dairy farm.

A longitudinal study of Shiga-toxigenic Escherichia coli (STEC) prevalence in three Australian diary herds

Veterinary microbiology, Volume 71, Issue 1-2, Pages 125-37, Jan 1, 2000

https://espace.library.uq.edu.au/view/UQ:a5186cb

Raw is risky: Netherlands study finds STEC and Campylobacter in dairy goats and dairy sheep, shows importance of pasteurization

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Researchers with the Dutch National Institute for Public Health and the Environment (RIVM) and the Dutch Food and Consumer Product Safety Authority (NVWA) shows that two types of bacteria that can cause diarrhea in humans ( STEC and Campylobacter) are common in dairy goat farms and dairy sheep farms, according to a RIVM press release (computer translated).

According to Outbreak News Today, in the animal study, 181 dairy goat farms and 24 dairy sheep farms were examined. STEC (Shiga-toxin-producing E. coli) and Campylobacter was found on most. STEC appeared on virtually all the farms studied. Campylobacter has been demonstrated in one out of three goat farms (33 percent) and almost all sheep farms (96 percent). These bacteria have found much less among cattle farmers and family members.

Listeria was less common, at about 9 percent of the goat and about 17 percent of the sheep farms. The bacteria was not found in the people studied. People run the risk of becoming infected with the listeria bacteria by eating raw milk soft cheese. The study also looked at Salmonella and ESBL-producing bacteria. These were not very common on the farms surveyed.

The results show that pasteurization of milk and hygiene after visiting a dairy goat farm or dairy sheep farm is important to prevent disease.

The bacteria found are in the intestines of the animals and thus enter the manure. A small amount of manure can contaminate raw milk or raw milk cheese. Contamination can be prevented by drinking only pasteurized milk or using it in other foods. In addition, people at a farm can become infected if they have contact with the animals or their environment. Visitors can reduce the risk of illness by washing their hands after contact with the animals or their environment.

In unrelated but related news, Brandon Macz of the Monroe Monitor reports that St. John Creamery in Monroe, Washington, announced on Thursday it is voluntarily recalling raw goat milk that may be contaminated with Escherichia coli (E.coli) bacteria.

A June 14 news release states the recall was initiated after “the presence of toxin-producing E.coli in retail raw goal milk dated 6/17” was discovered during routine sampling by the Washington State Department of Agriculture.

Included in the recall are half-gallon and one-pint containers of raw goat milk marked best by June 17-21.

HSE investigates highly contagious and dangerous case of e coli in Laois, Ireland

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The Health Service Executive is investigating a suspected case of E coli in a baby in Laois.

Sinead Moore of RSVP Live reports the HSE launched an investigation late last week after a potentially serious strain of the bacteria was suspected in the Irish infant.

The strain, called VTEC or verotoxigenic E coli, comes from contact with faeces of healthy farm animals. It can be spread through children’s shared toys or during nappy changing.

The child is understood to have since been diagnosed with the less dangerous E coli bacteria, the Leinster Express reports.

The bacteria can cause vomiting and diahorrea.

As part of the investigation, the creche the baby attends, Sonas Community Childcare Centre in Mountmellick Co Laois was contacted last Friday to raise awareness among staff and parents and to examine if other children attending the creche had any similar symptoms.

Two gorillas at Milwaukee zoo likely died from water contaminated with E. coli

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Two gorillas at the Milwaukee County Zoo likely died after ingesting water contaminated with E. coli, according to zookeepers.

Cassius, an adult male, died on April 12, and Naku, a 17-year-old female western lowland gorilla, died on April 29, the zoo said in a press release.

Autopsy results for the gorillas show that they died of gastrointestinal infections believed to have been caused by E. coli in their water supply, according to the zoo.

The water systems in the gorilla and bonobo areas have been disinfected, the zoo said, adding that the water supply available for consumption by the public was never affected.

Zookeepers are also using new protocols to disinfect produce, which can be another source of E. coli, according to the release.

While all animals, including gorillas and even humans, have healthy E.coli in their gut, some variants of E. coli can cause intestinal damage and disease, the zoo said.

Naku had been euthanized after veterinarians found that a portion of her intestine was no longer functioning, ABC affiliate WISN in Milwaukee reported.

Cassius and Nauku’s 8-month-old baby, Zahra, is now an orphan.

Zahra’s diet has consisted mainly of formula in the absence of her mother’s breast milk, zookeepers wrote on Twitter. She is also eating some produce, sweet potato, red pepper, and beans, the zoo said.

‘Close to 10 children hospitalized for E. coli’ in Tennessee: raw milk, farm animals may be sources

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Kristi Nelson of Knox News reports East Tennessee Children’s Hospital said Tuesday it’s treated “close to 10” children, all younger than 4, for a “serious outbreak” of E. coli-caused illness over the past 10 days. 

The Knox County Health Department has confirmed two likely sources of the outbreak are unpasteurized milk and farm animals.

Most of the ill children are known to have consumed raw milk from a local cow-share dairy, French Broad Farm in Knox County, the health department said in an alert issued Tuesday evening. The health department recommends consumers dispose of all raw milk or other unpasteurized products they may have from this farm.

“People need to be aware that if they choose to drink raw milk, they’re taking a risk,” said Dr. Martha Buchanan, health department director.

The health department is also investigating whether any of the affected children were exposed to E. coli after interacting with farm animals at a local child care facility. The facility, which officials declined to name, is not currently operating, Buchanan said.

Four of the children are in the Pediatric Intensive Care Unit with kidney failure, said the hospital’s chief medical officer, Dr. Joe Childs, who is director of the PICU. There have been no fatalities related to the outbreak, hospital staff said, but life-threatening infections can occur when the strain of E. coli releases a toxin, shiga, that harms small blood vessels, of which the kidneys have many. Childs said the damage to the blood vessels is usually “temporary,” but children can get very ill, require surgery to place catheters, and may have nonfunctioning kidneys for weeks. 

“We are concerned that some of these cases do have exposure to the consumption of raw milk,” or milk sold unpasteurized, Childs said. “Tennessee is a state where that’s legal, to obtain raw milk. … The FDA and the American Academy of Pediatrics strongly discourage the consumption of raw milk and raw milk products because there’s a lot of things that can be in milk and there’s no real good way to decontaminate it other than pasteurizing it.” 

We let our kids explore the world, they get raw milk and barf

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Following a school ski-trip to Austria from 10-18/02/2017, nine of 25 participants of the group from Lower Saxony (Germany) developed gastroenteritis. The students and teachers (17-41 years) shared meals in a hotel. Active case finding revealed further cases among German school groups from North Rhine-Westphalia and Schleswig-Holstein, staying at the same hotel in February 2017.

We conducted two retrospective cohort studies using self-administered questionnaires on clinical symptoms and food consumption. We defined a case as a trip participant in February 2017, staying at the aforementioned hotel and developing diarrhoea, vomiting or abdominal pain during or within ten days after the trip and/or who had a stool sample tested positive for STEC within four weeks after the trip. During the outbreak investigation, Austrian authorities detected that unlabeled raw cow milk delivered by a dairy farm had been offered at the hotel for breakfast during January and February 2017. Stool samples of participants, samples of milk served in the hotel and fecal samples of various animals kept at the milk-delivering farm were examined by culture and polymerase chain reaction. STEC isolates were typed using Pulsed-field Gel Electrophoresis (PFGE) and Whole-Genome Sequencing (WGS).

All 25 participants from Lower Saxony completed the questionnaire on symptoms and milk consumption; 14 were cases (56%). Thirteen of 20 participants who had consumed cold milk fell ill (risk ratio (RR): 3.25; 95%-confidence interval (CI): 0.55-19.32). Of 159 trip participants from North Rhine-Westphalia, 81 completed the questionnaire (51%), 25 were cases (31%); RR for cold milk was 2.11 (CI: 0.89-5.03). The combined RR for cold milk in both groups was 2.49 (CI: 1.16-5.35). Shiga toxin 1a-gene and eaeA-gene positive STEC O103:H2 were detected in nine of 32 patients’ stool samples and in two of 18 dairy farm cattle. Nine isolates from human stool samples and two isolates from cattle fecal samples yielded the same strain with an almost identical PFGE-pattern and WGS-profile.

Microbiological and epidemiological evidence identified raw cow milk as the vehicle. Results may have been compromised by misclassification of cases due to a recall bias and mild symptoms. As a result of this outbreak investigation, the Austrian authorities enforced Austrian law in the hotel, to provide milk only when pasteurized. We recommend re-emphasizing the risk of raw milk consumption to providers.

Shiga toxin-producing Escherichia coli O103:H2 outbreak in Germany after school trip to Austria due to raw cow milk, 2017-The important role of international collaboration for outbreak investigations, 29 May 2018

International Journal of Medical Microbiology

Maren Myliusa, b, c, , , Johannes Dreesmana, , Matthias Pulza, , Gerhard Pallaschd, , Konrad Beyrera, , Katja Claußena, ,  Franz Allerbergere, ,  Angelika Fruthf, ,  Christina Langf,  Rita Pragerf,  Antje Fliegerf,  Sabine Schlagere, ,  Daniela Kalhöferg, ,  Elke Mertensa, 

https://doi.org/10.1016/j.ijmm.2018.05.005

https://www.sciencedirect.com/science/article/pii/S1438422118301905

PMA: Research on produce safety priorities

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Bob Whitaker, Ph.D., chief science and technology officer for Produce Marketing Association (PMA), writes that because it provides inherently healthy, nutritious foods, the fresh produce industry is uniquely positioned to help solve the nation’s obesity epidemic. To do so, consumers must have confidence in the safety of the fresh fruits, vegetables, and nuts they eat and feed their families.

A green row celery field is watered and sprayed by irrigation equipment in the Salinas Valley, California USA

Following a large and deadly outbreak of foodborne illness linked to fresh spinach in 2006, the U.S. produce industry couldn’t wait for government or other direction. After finding significant knowledge gaps and a lack of data needed to build risk- and science-based produce safety programs, the industry created the Center for Produce Safety (CPS) in 2007.

CPS works to identify produce safety hazards, then funds research that develops that data as well as potential science-based solutions that the produce supply chain can use to manage those hazards. While two foodborne illness outbreaks in the first half of 2018 associated with leafy greens demonstrate the industry still has challenges to meet, CPS has grown into a unique public-private partnership that moves most of the research it funds from concept to real-world answers in about a year.

Each June, CPS hosts a symposium to report its latest research results to industry, policy makers, regulators, academia, and other produce safety stakeholders. Key learnings from the 2017 symposium have just been released on topics including water quality, cross-contamination, and prevention. A few highlights from those key learnings are summarized here, and for the full details, you can download the Key Learnings report from CPS’s website.

Know Your Water (we were doing that in 2002, long before youtube existed)
Irrigation water is a potentially significant contamination hazard for fresh produce while it is still in the field. While CPS research has revealed many learnings about agricultural water safety in its 10 years, many questions still remain. Meanwhile, the U.S. Food and Drug Administration (FDA)’s proposed Food Safety Modernization Act (FSMA) water testing requirements—which offers some challenges for producers in specific production regions—recently raised even more questions.

New CPS research illustrates the risks of irrigating with “tail water” from runoff collection ponds. With water becoming a precious resource in drought-stricken areas, the objective was to learn if tail water might be recovered and used for irrigation.  We learned that differences among pond sites—for example, water sources, climate, ag management practices—can strongly influence the chemistry and microbiology of the water. Further, water pH can influence disinfection treatment strategies.[1]

CPS research continues to investigate tools for irrigation water testing, looking specifically at sample volumes,[2] and searching for better water quality indicators and indexing organisms including harnessing next-generation DNA sequencing.[3] Following a CPS-organized colloquium on ag water testing in late 2017, FDA subsequently announced it would revisit FSMA’s ag water requirements, and postponed compliance.

Bottom line, CPS research demonstrates that growers must thoroughly understand their irrigation water before they can accurately assess cross-contamination risk. CPS’s findings clearly point to the need to take a systems approach, to understand and control the entire water system to help achieve produce safety. Long term, this may mean prioritizing research into ag water disinfection systems to better manage contamination hazards that can also operate at rates needed for field production.
Cross-Contamination Can Happen across the Supply Chain
While conceptually and anecdotally the fresh produce industry knows that food safety is a supply chain responsibility, research is needed that documents the role of the entire supply chain to keep fresh produce clean and safe from field to fork. At the 2017 CPS Research Symposium, research reports were presented focusing on cross-contamination risks from the packinghouse to retail store display.

In the packinghouse, CPS-funded research found that wash systems can effectively control cross-contamination on fruit, when proper system practices are implemented.[4] Post-wash, CPS research involving fresh-cut mangos also demonstrated that maintaining the cold chain is critical to controlling pathogen populations.[5] Across the cantaloupe supply chain, CPS studies show food contact surfaces—for example, foam padding—are potential points of cross-contamination.[6] See the full 2017 Key Learnings report for details, as these brief descriptions only scratch the surface of this research.

CPS studies clearly demonstrate that food safety is a supply chain responsibility—a message that must be internalized from growers and packers to transporters, storages, and retailers to commercial, institutional, and home kitchens. While translating this research into reality will present engineering and operational challenges, our new understanding of produce safety demands it.
Verifying Preventive Controls
The produce industry must know that its preventive controls are in fact effective. That said, validation can be tricky. If validation research doesn’t mimic the real world, industry ends up fooling itself about whether its food safety processes work—and the human consequences are real.

Numerous scientists presented research at the 2017 CPS Research Symposium that validates various preventive controls, from heat treating poultry litter[7] to pasteurizing pistachios[8] to validating chlorine levels in wash water systems.[9] Some researchers effectively used nonpathogenic bacteria as a surrogate in their validation studies, while another is working to develop an avirulent salmonella surrogate, and another. Wang used actual Escherichia coliO157:H7 (albeit in a laboratory).

Importantly, CPS research finds that the physiological state of a pathogen or surrogate, and pathogen growth conditions themselves, are critically important to validation studies.[10] Meanwhile, suitable surrogates have been identified for some applications, the search continues for many others.

The research findings described here are just some of the real world-applicable results to emerge from CPS’s research program. To learn more, download the 2017 and other annual Key Learnings reports from the CPS website > Resources > Key Learnings page at www.centerforproducesafety.org.

We were doing these videos in the early 2000s, long before youtube.com existed, and weren’t quite sure what to do with them. But we had fun.

 

25 sickened Don’t make mousse in a bowl used to prep raw meat: Settlement for kids in Nevada sickened by E. coli

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Brian Duggan of the Reno Gazette Journal reports that more than two years after they got sick from eating E. coli-tainted chocolate mousse cake at two Reno restaurants, six children are now awaiting a Washoe judge to approve their financial settlements, according to court records.

The six Reno-area children were all plaintiffs in a lawsuit that followed Washoe County’s worst-ever E. coli outbreak that also sickened two other children and 17 adults.

The outbreak started in October 2015 when the tainted dessert was prepared in a mixing bowl that had been used to process raw meat at Reno Provisions. The cake was later served at Heritage, located inside the Whitney Peak Hotel, and South Reno’s Twisted Fork. 

Owner Mark Estee later closed Reno Provisions. Estee was a consulting chef at Heritage, which was later changed into the Roundabout Grill. Twisted Fork is still in business and has passed all of its restaurant inspections since the 2015 outbreak with no violations, according to Washoe County Health District data.

In all, the children will get $2.5 million — 90 percent of that shared between two boys who had extensive stays at the UC Davis Medical Center to treat their injuries, according to court records.

Estee did not return requests to be interviewed for this story. A representative with Twisted Fork and victims of the outbreak also declined comment. 

Brent L. Ryman, who represented Reno Provisions, said several lawsuits were initially filed by victims of the outbreak in 2015 and 2016. Those lawsuits were later consolidated into one case that ended in financial settlements without the need for a trial. The settlements with the adults who got sick are private and did not require a judge’s approval. 

Two of the boys developed serious kidney complications because of the E.coli infection, said Bill Marler, a Seattle-based attorney who represented nine of the plaintiffs in the case.