Escherichia coli O157 is a human pathogen carried asymptomatically by cattle and shed in their feces. Infection can occur from the consumption of contaminated beef or by direct contact.
Large variations of E. coli O157 shedding in cattle exist and vary in the number of cattle positive for E. coli O157 and the amount of bacteria (c.f.u./g feces) shed by positive animals. To investigate E. coli O157 shedding and super-shedding (>104 c.f.u./g) we used daily sampling over two 8-day periods; in January 2013 (n = 12) and February 2013 (n = 21).
Samples were tested by direct faecal culture for enumeration and by immunomagnetic separation to detect lower levels of shedding. We identified three patterns of shedding, similar to previously observed descriptions: intermittent, transient and consistent. The most commonly observed pattern was intermittent shedding and variation in the level of shedding could be large. This extreme variation is demonstrated by a heifer from which E. coli O157 could be not detected one day, was super-shedding E. coli O157 the next and was detected as shedding >100 c.f.u./g the following day. Recto-anal mucosal swab testing did not predict super-shedding in this cohort of heifers.
The variable individual patterns of shedding suggest that a common mechanism of infection may not operate within such a herd when considering previously described patterns and the inferred mechanisms. The sporadic and intermittent nature of shedding is a challenge to identifying risk factors and potential intervention strategies.
Daily variations in Escherichia coli O157 shedding patterns in a cohort of dairy heifers at pasture
Daily variations in Escherichia coli O157 shedding patterns in a cohort of dairy heifers at pasture
My longtime friend and mentor, Denton Hoffman, has fallen on hard times.
Literally.
He slipped on some icy stairs in Guelph, had brain swelling and a subsequent stroke (that’s Denton on the right, with my asparagus baron grandfather, about 15 years ago).
At the suggestion of Gord Surgeoner, I met with Denton as a newly minted prof back in 1998 to devise an on-farm food safety program for the Ontario Greenhouse Vegetable Growers. At least three of my grad students went through the drill, and there was this time, we thought we’d killed Chapman.
Ben and I went along with Uncle Denton to the Canadian Horticulture Council meeting in Montreal in Feb. 2003. I had chaired a national committee on on-farm food safety program implementation – and the advice was completely ignored – Chapman and I had done years of groundwork with Denton and the Ontario Greenhouse Vegetable Growers, and we agreed to share a room at the annual meeting to cut down on expenses.
There was a couple of receptions and I still remember Ben and I asking Uncle Denton for drink tickets. We then retired to a hotel lounge and I knew trouble was ahead when Chapman asked for a cigarette.
He then went to the bathroom.
He didn’t return.
He showed up a few hours later, seemingly intact.
In 2009, Denton wrote:
As you journey through life you meet the occasional person who makes a real difference. Dr. Douglas Powell is one of those – to say the least.
Doug called me recently to talk about the early years. He was new in the On Farm Food Safety business when I was working with the Ontario Greenhouse vegetable group. Doug was at the University of Guelph and I would talk to him about the phone call I didn’t want to get. This would be the imaginary call from a senior’s residence wondering why all the occupants were very sick after consuming a fresh salad, and if the cause may have been the greenhouse tomatoes. I never got that call—thank God–but I wanted to be ready. And that readiness included a strong response indicating we had an On Farm Food Safety program and proof we were capable of tracing our greenhouse product. We’ve seen several incidences in the past few years with certain fresh veggies and berries that almost ruined the industry and certainly crippled those markets for a year or so.
From the University of Guelph and the beginning of the On Farm Food Safety program, Doug has moved to Kansas State University where he is associate professor of food safety. He is still very much in the industry – just relocated to a different university — and still writing newsletters, hence the reputation of “the guru” of On Farm Food Safety.
Doug has remained a good friend over all these years. We developed a bond as we developed an On Farm Food Safety program for greenhouse vegetables and more. Doug’s philosophy was to keep it simple. He could relate to growers, and had an uncanny ability to make the complicated science of bacterial contamination simple and understandable. Early on, he received a little help from Dr. Gord Surgeoner. These were the seeds of the On Farm Food Safety program in Canada, spreading from Ontario Greenhouse to CHC and to most vegetable growers across Canada.
I can still see Doug in an old T-shirt and jeans, holes in both, and running shoes–that was his fashion statement. Of course, his description of toilet paper “slippage” resulting in fecal contamination on your finger was priceless, but his crude description helped to break down the mystery of bacterial contamination by food handlers with dirty hands. Seems to me I got a T-shirt from Doug with “Don’t Eat Poop” written on the front. Doug continues to be a great communicator, a fair goalie, poor at politics but great at On Farm Food Safety and raising little girls.
Thanks, Doug. I am proud to say I knew you back when.
And as Ben said yesterday, Denton was a great mentor on how to deal with crazy industry folks.
Denton’s brain still works, and he can be contacted at: 222 Mountainview Road North suite 217
Increased listeriosis incidence among older adults (≥60 years) has been reported internationally, with many cases reported to be sporadic and associated with ready-to-eat (RTE) food products with extended refrigerated shelf life. Given that the home kitchen is recognized as a significant location where foodborne illnesses are acquired, it is important that consumers implement safe food practices to minimize risks. This is crucial for vulnerable consumers, such as older adults.
Consumer food safety recommendations in the United Kingdom to reduce the risk of listeriosis at home include (i) following “use-by” dates on unopened prepacked RTE food products, (ii) consuming RTE food products within 2 days of opening, and (iii) ensuring the safe operating temperatures of domestic refrigerators (≤5°C).
This study utilized observation, self-reporting, and microbiological analysis to determine actual food storage practices to identify behavioral risk factors. A domestic kitchen survey was conducted in older adult (≥60 years) consumers’ domestic kitchens (n = 100) in South Wales, United Kingdom. Forty-one percent of foods in home refrigerators were beyond the use-by date, of which 11% were unopened RTE food products commonly associated with listeriosis. Sixty-six percent of opened RTE foods had been or were intended to be stored beyond the recommended 2 days after opening. Older adults failed to ensure safe refrigeration temperatures, with 50% of central storage and 85% of door storage areas operating at temperatures >5°C. Older refrigerators operated at significantly (P < 0.05) higher temperatures.
Given that Listeria monocytogenes was isolated in 2% of kitchens, these findings suggest that storage malpractices may have a greater effect on the potential risk of listeriosis than its presence alone. The study has determined that many older adults fail to adhere to recommendations and subject RTE foods associated with L. monocytogenes to prolonged storage at unsafe temperatures which may render food unsafe for consumption.
Analysis of older adults’ domestic kitchen storage practices in the United Kingdom: identification of risk factors associated with listeriosis
Survival and growth of Salmonella was also assessed after subsequent brewing using dried inoculated teas.
A Salmonella enterica serovar cocktail was inoculated onto different dried tea leaves or flowers to give starting populations of approximately 10 log CFU/g. The inoculum was allowed to dry (at ambient temperature for 24 h) onto the dried leaves or flowers prior to storage under 25 and 35°C at low (<30% relative humidity [RH]) and high (>90% RH) humidity levels. Under the four storage conditions tested, survival followed the order 25°C with low RH > 35°C with low RH > 25°C with high RH > 35°C with high RH. Salmonella losses at 25°C with low RH occurred primarily during drying, after which populations showed little decline over 6 months. In contrast, Salmonella decreased below detection after 45 days at 35°C and high RH in all teas tested. The thermal resistance of Salmonella was assessed at 55°C immediately after inoculation of tea leaves or flowers, after drying (24 h) onto tea leaves or flowers, and after 28 days of storage at 25°C with low RH. All conditions resulted in similar D-values (2.78 ± 0.12, 3.04 ± 0.07, and 2.78 ± 0.56, at 0 h, 24 h, and 28 days, respectively), indicating thermal resistance of Salmonella in brewed tea did not change after desiccation and 28 days of storage.
In addition, all brewed teas tested supported the growth of Salmonella. If Salmonella survives after storage, it may also survive and grow after a home brewing process.
Survival of Salmonella on chamomile, peppermint, and green tea during storage and subsequent survival or growth following tea brewing
The survival of Salmonella and Escherichia coli O157:H7 on strawberries, basil leaves, and other leafy greens (spinach leaves, lamb and butterhead lettuce leaves, baby leaves, and fresh-cut iceberg lettuce) was assessed at cold (<7°C) and ambient temperatures. All commodities were spot inoculated with E. coli O157:H7 or Salmonella to obtain an initial inoculum of 5 to 6 log and 4 to 5 log CFU/g for strawberries and leafy greens, respectively. Samples were air packed. Strawberries were stored at 4, 10, 15, and 22°C and basil leaves and other leafy greens at 7, 15, and 22°C for up to 7 days (or less if spoiled before).
Both Salmonella and E. coli O157:H7 showed a gradual decrease in numbers if inoculated on strawberries, with a similar reduction observed at 4, 10, and 15°C (2 to 3 log after 5 days). However, at 15°C (and 10°C for E. coli O157:H7), the survival experiment stopped before day 7, as die-off of both pathogens below the lower limit of detection was achieved or spoilage occurred.
At 22°C, strawberries were moldy after 2 or 4 days. At that time, a 1- to 2-log reduction of both pathogens had occurred. A restricted die-off (on average 1.0 log) and increase (on average , 0.5 log) of both pathogens on basil leaves occurred after 7 days of storage at 7 and 22°C, respectively. On leafy greens, a comparable decrease as on basil was observed after 3 days at 7°C. At 22°C, both pathogens increased to higher numbers on fresh-cut iceberg and butterhead lettuce leaves (on average 1.0 log), probably due to the presence of exudates. However, by using spot inoculation, the increase was rather limited, probably due to minimized contact between the inoculum and cell exudates.
Avoiding contamination, in particular, at cultivation (and harvest or postharvest) is important, as both pathogens survive during storage, and strawberries, basil, and other leafy green leaves are consumed without inactivation treatment.
Survival of Salmonella and Escherichia coli O157:H7 on strawberries, basil, and other leafy greens during storage
Laura Otolski of Takoma Park, Maryland, writes that as a registered dietitian-nutritionist, my work has focused on not only what to eat, but also on how to keep food safe to eat. This has included seven years at a D.C.-based organization that provides home-delivered meals to people living with HIV/AIDS, cancer and other life-challenging conditions.
My department there monitored food safety, which involved thorough inspections of the kitchen twice a week, and regular reviews of proper hygiene procedures with both new and longtime volunteers. Both staff and volunteers knew not to work in the kitchen when they were ill, in order to prevent contamination.
These practices are absolutely necessary when you are feeding people with compromised immune systems. Indeed, such rules should be in place in any food service establishment.
Two factors made successful infection control more likely at that organization.
First, the kitchen staff were provided with paid sick leave, and, second, the volunteers were not under financial pressure to come in when they were not feeling well. No one was worried about losing a day’s pay, or their job.
All employees need to have that kind of security. Workers need to be able to stay home when they are ill, and keep infectious diseases out of the workplace. Everyone gets sick, so everyone should have the opportunity to earn sick days.
It’s a recurring story, one that Jim Romahn has reported on for decades: the good meat gets exported, the inferior stuff stays at home.
It’s the same with Australian seafood, unless you know where to buy.
According to Canadian union thingy Bob Kingston, cuts to Canada’s food inspection programs have created a double standard, where meat sold to Canadians is not as well inspected than that destined for export.
“Lives are at risk, [there’s] the real likelihood that people will die. And I hope they wake up to this.”
At a news conference in Edmonton today, Kingston said since January, the Canadian Food Inspection Agency (CFIA) has quietly rolled back inspections at meat plants in northern Alberta. Increased inspections were put in place following a 2008 listeriosis outbreak tied to Maple Leaf Foods products, which resulted in 22 deaths.
“There’s no public debate. There isn’t even an industry debate about what’s going on. It’s the rollback of those commitments to protect Canadians,” he said.
He said the CFIA has cut the presence of inspectors in facilities from five days a week to three – but only in plants that produce meat for the domestic market. The presence of inspectors in plants inspecting for export have stayed the same.
Dr. Sylvain Charlebois, a University of Guelph professor who studies food safety, said the changes do not mean Canadian meat is less safe to eat.
“I don’t think the health of Canadians has been compromised,” he said.
“Canadian-destined meat doesn’t get less attention. It just gets different attention.”
He said given the CFIA’s resources, the agency’s changes are the “right way” to approach inspections. Reducing inspections of plants making domestically bound meat was done because the government has confidence in those facilities. Putting resources towards protecting exports is a vital task, he argued.
Charlebois don’t know much about food safety.
Keith Warriner, director of the food safety and quality assurance program at the University of Guelph, who knows more, said the implication that the meat sold in Canada is unsafe is “a little bit of scare-mongering.”
He said the union’s argument, that fewer inspectors inherently means people are at risk, isn’t true.
“If you had a policeman on every corner, yes, crime might go down,” he said.
“But the better thing is, isn’t it, to instill into people not to commit the crime in the first place.”
Internal and external food safety audits are conducted to assess the safety and quality of food including on-farm production, manufacturing practices, sanitation, and hygiene. Some auditors are direct stakeholders that are employed by food establishments to conduct internal audits, while other auditors may represent the interests of a second-party purchaser or a third-party auditing agency. Some buyers conduct their own audits or additional testing, while some buyers trust the results of third-party audits or inspections. Third-party auditors, however, use various food safety audit standards and most do not have a vested interest in the products being sold. Audits are conducted under a proprietary standard, while food safety inspections are generally conducted within a legal framework. There have been many foodborne illness outbreaks linked to food processors that have passed third-party audits and inspections, raising questions about the utility of both. Supporters argue third-party audits are a way to ensure food safety in an era of dwindling economic resources. Critics contend that while external audits and inspections can be a valuable tool to help ensure safe food, such activities represent only a snapshot in time. This paper identifies limitations of food safety inspections and audits and provides recommendations for strengthening the system, based on developing a strong food safety culture, including risk-based verification steps, throughout the food safety system.
As two Australian Football League players (the ice hockey of footie) claim their positive tests for clenbuterol came from steak consumed in New Zealand (that’s just scientifically BS, as cyclist Alberto Contador proved in 2010 ), the European Food Safety Authority is extending the use of its harmonised sample-based data reporting model to the collection of data on veterinary medicinal product residues in animals and animal products.
Sample-based reporting using standardized description elements is already used to collect occurrence data from Member States in areas such as food additives, chemical contaminants, pesticide residues and antimicrobial resistance.
Monitoring data on veterinary medicinal product (VMP) residues are currently submitted annually in an aggregated format to a database maintained by the European Commission. EFSA then examines the data and presents the results in annual reports. However, aggregation does not lend itself to complex statistical analysis and is of limited value for quantitative exposure and risk assessments. The move to direct collection of data in a sample-based format will enable EFSA and the European Commission to tackle questions related to the risk assessment and risk management of VMP residues.
I vote for Lynn (right, exactly as shown) who’s either really happy to see me or holding a fish.
The UK consumerist outfit, Which? has called on the new food standards organisation for Scotland to “operate transparently as a strong, independent consumer champion”.
The organisation has set out a priority list for the new Food Standards Scotland agency’s first year, including ensuring it adequately tackles food fraud and misleading practices.
The FSS is launched today, taking over full operational control from the Food Standards Agency, providing Scotland with regulation and independent advice on food safety and standards, food information and nutrition.
Which? said it should act on recommendations of reports conducted in the wake of the 2013 horsemeat contamination scandals by Chris Elliott, professor of food safety and director of the Institute for Global Food Security at Queen’s University, Belfast and Professor Jim Scudamore for the Scottish Government. That would mean improving intelligence gathering, stepping up surveillance and investigating and prosecuting potential breaches.
There was this time, about five years ago, when the U.S. Department of Agriculture decided to consult with everyone they could find to chat about food safety messaging.
I participated in good faith, but soon dropped out, because it was apparent the folks in charge had their minds made up, and my – and dozens of others – time on the phone was a consultative circle jerk.
The result was those embarrassing Ad Council ads with a pig in a sauna.
I was vocal, saying that cook, clean, chill, separate places too much blame on the consumer and doesn’t account for choosing safety: source food from verifiable safe sources.
Nope, weren’t having any of that, even though the World Health Organization has been promoting that message for 15 years (one of my former students worked on this, years ago).
On World Health Day 2015, WHO/Europe estimates that levels of foodborne disease are much higher than currently reported and underlines the need for improved collaboration among sectors to lower the health risks associated with unsafe food.
Our food chain is longer and more complex than ever before, and demographic, cultural, economic and environmental developments – globalized trade, travel and migration, an ageing population, changing consumer trends and habits, new technologies, emergencies, climate change and extreme weather events – are increasing foodborne health risks.
“The fact that we significantly underestimate how many people become ill from chemicals in the food chain and from common microorganisms such as Salmonella and Campylobacter should start alarm bells ringing across the many areas with a stake in our food chain. A failure in food safety at any link in this chain, from the environment, through primary production, processing, transport, trade, catering or in the home, can have significant health and economic consequences,” says Dr Zsuzsanna Jakab, WHO Regional Director for Europe.
*Contamination from a single source may become widespread and have enormous health and economic consequences. In 2011, for example, an enterohaemorrhagic Escherichia coli (EHEC) outbreak in Germany and France, linked to imported contaminated fenugreek seeds, led to almost 4000 cases of EHEC infection in 16 countries, including more than 900 haemolytic uraemic syndrome (HUS) cases and 55 deaths. The estimated loss for farmers and industries was US$ 1.3 billion.
*Changes in animal food production are leading to an increase in the emergence and spread of zoonotic diseases. Of 335 emerging infectious disease events in humans between 1940 and 2004, it is estimated that 60% were transmitted from animals and many of these were foodborne.
WHO calls on policy-makers:
*To build and maintain adequate food safety systems and infrastructures, including laboratory capacities and surveillance and reporting systems;
*To respond to and manage food safety risks along the entire food chain, including during emergencies;
*To foster multisectoral collaboration among public health, animal health, agriculture and other sectors for better communication, information sharing and joint action;
*To integrate food safety into broader food policies and programmes (e.g. nutrition and food security);
*To think globally and act locally to ensure that food produced domestically is as safe as possible internationally.
World Health Day 2015, celebrated on 7 April, is an opportunity to recognize the important food safety role of all those involved in food production, and to strengthen collaboration and coordination among these various areas, in order to prevent, detect and respond to foodborne diseases efficiently and cost-effectively. A kaleidoscope of events is planned across the globe.
People are also invited to engage through social media and to promote “From farm to plate: make food safe” using the hashtag #safefood.
The World Organisation for Animal Health (OIE) says to be able to meet the demand for milk, eggs and meat and guarantee their safety, it is first of all essential to control pathogens in animals on the farm.
Eliminating or controlling food hazards at source has proved more effective than an approach relying solely on checking the finished product.
Large variations of E. coli O157 shedding in cattle exist and vary in the number of cattle positive for E. coli O157 and the amount of bacteria (c.f.u./g feces) shed by positive animals. To investigate E. coli O157 shedding and super-shedding (>104 c.f.u./g) we used daily sampling over two 8-day periods; in January 2013 (n = 12) and February 2013 (n = 21).
Survival and growth of Salmonella was also assessed after subsequent brewing using dried inoculated teas.
