A former professor of food safety and the publisher of barfblog.com, Powell is passionate about food, has five daughters, and is an OK goaltender in pickup hockey. Download Doug’s CV here.
Dr. Douglas Powell
editor, barfblog.com
retired professor, food safety
3/289 Annerley Rd
Annerley, Queensland
4103
dpowell29@gmail.com
61478222221
I am based in Brisbane, Australia, 15 hours ahead of Eastern Standard Time
Liz Braun of the Toronto Sun writes the aptly named Poop Café has received a yellow rating from the Toronto Public Health food safety program
In other gross out news, a recent edition of barfblog recaps a CBSLA report about how the delivery guy from Ubereats might be munching on your fries or sipping your drink before those items are delivered to you. Think about that the next time you call DoorDash or Foodora.
If that’s not disgusting enough, barfblog will also let you read all about how many sushi joints in Ireland fail to meet food safety standards, or even about mice in an Amsterdam crepe restaurant. Ewwww!
I love the sourness of blackberries. As a child I used to pick baskets full to be made into pies by my aunt. As a grown up in Guelph (that’s in Canada) there was a huge blackberry tree next door and I would pick baskets full and make pies.
Hepatitis A cases in three states that are “potentially linked” to fresh blackberries bought at Fresh Thyme Farmers Markets stores in September.
Six of the 11 people who’ve been diagnosed have been hospitalized, according to the Food and Drug Administration, which is investigating the outbreak with the Centers for Disease Control and Prevention.
A Nov. 20 notice from the FDA said hepatitis A illnesses in Indiana, Nebraska and Wisconsin are potentially linked to fresh conventionally-grown blackberries. Patients told FDA investigators they bought and consumed the berries from Fresh Thyme Farmers Markets in those three states.
The blackberries came from a distribution center that served 11 states, and the FDA is working with “federal and state partners to obtain additional information during the traceback investigation,” according to the notice.
Fresh Thyme released a statement that there is no indication the berries were contaminated by in-store handling and only conventional blackberries sold from Sept. 9-30 are involved.
The girls are off in the French territory of New Caledonia doing Amy-directed French biz and yesterday they went to Lifou, Island, part of the Loyalty Islands which the French decided would be useful way back when.
I look forward to their tales.
I spoke at an Australian food safety conference in 2004 on the Gold Coast and mentioned something about grocery trolleys in an interview and that segment made it to the national news.
Not my intent.
I was trying to point out possible short cummings of food safety for shoppers, and subsequently spent four hours going through my local Coles – biggest supermarket in Australia – with the vp of food safety, pointing out their vulnerabilities, like:
if you’re going to cut a melon in half, please ensure it is kept at 4C (better not to cut it in half)
label frozen meat products properly i.e. is it needle tenderized, are those frozen dished raw frozen or cooked frozen
what criteria do you have for produce on shelves.
The objective of this study was to identify food safety risk factors associated with supermarket trolleys (grills and handles) and handheld baskets. Indicator microorganisms evaluated were those detected by aerobic plate count (APC), yeast and molds (YM), Enterobacteriaceae (EB). Environmental listeria (EL), coliforms (CF), and E. coli (EC). In addition, listeria monocytogenes, staphylococcus aureus, Escherichia coli O157 and salmonella sp. Were tested for. Trolley grills (n=36) had 2.7 x 102 CFU/cm2. Trolley handles (n=36) had 2.7 x 106 of CF and 5.2 CFU/cm2 of YM. The bottom of handheld baskets (n=25) had 3.5 x 105 CFU/cm2 of CF and 5.07 CFU/cm2 of EC. S. aureus was found on 96% of the baskets, 50% of the trolley handles (18 out of 36 samples), and 42% of the trolleys’ grills. E. coli O157 was identified on 17% of baskets, 3% on trolley grills, and 3% on handles. Salmonella sp. was detected on 16% of baskets and 8% of trolley grills. L. monocytogenes was detected on 17% of the bottoms of handheld baskets but on none of the other samples. These results suggest the need for implementation of sanitation programs to regularly clean trolleys and baskets, as well as for consumer education.
Microbial contamination of grocery shopping trolleys and baskets in west Texas, 2020
Food Protection Trends vol. 40 no. 1
Alexandra Calle, Breyan Montoya, Andrea English, and Mindy Brashears
The bacterial pathogen Shigella, often spread through contaminated food or water, is a leading cause of mortality in both children and older adults in the developing world. Although scientists have been studying Shigella for decades, no effective vaccine has been developed, and the pathogen has acquired resistance to many antibiotics. The recent discovery of an early adherence step in the infection cycle by researchers at Massachusetts General Hospital (MGH) could provide a new therapeutic target or even a new method for vaccine development.
As it moves through the digestive system, Shigella traverses the small intestine and subsequently infects the large intestine, causing cramping, diarrhea and dehydration in the disease called shigellosis.
“We wanted to determine how Shigella makes its first contact with epithelial cells in the early stages of disease development,” says Dr. Christina Faherty, senior author on the study published in mSphere. “Because of certain gene sequence annotations, and the way that Shigella appeared following growth in standard laboratory media, it was believed that Shigella strains do not produce fimbriae or other adherence factors.” Fimbriae are short hair-like fibers that bacterial cells use to adhere to individual epithelial cells to instigate infection.
The work of Faherty and the research team has uncovered evidence of fimbriae that aid adherence to epithelial cells, an important step in the start of a shigellosis infection. “We mimicked the conditions that Shigella would face in its journey through the small intestine by adding bile salts and glucose to laboratory media,” says Faherty. “With this method, we discovered what had been hidden in plain sight before–the gene expression profiles that enabled Shigella to initiate this early step in infection by attaching to the epithelial tissue of the host.”
Chapman and I have know for decades that when someone says they’re going to educate someone else about food safety stuff, it is doomed to failure.
The key to learning is, and always has been, storytelling.
Embed your data or facts within the story.
The Science of Storytelling (2019) shows you how to craft a compelling story using lessons from psychology and neuroscience. These blinks walk you through the steps of creating a narrative that grips your audience by subtly manipulating their brains. From demonstrating how to create a perfectly flawed character to explaining the power of stimulating details, Will Storr reveals the crucial elements that go into building a great story.
Diets rich in minimally processed foods are associated with numerous health benefits, in part, due to their diverse, natural microbiota. However, antimicrobials, such as chlorine and peracetic acid (PAA), that are used to address food safety concerns may damage the natural microflora of fresh produce.
One promising approach for targeting pathogenic bacteria in foods without impacting the normal food microbiota are bacteriophages. In this study, we observed that combinational treatment of conventional antimicrobials (PAA and chlorine) and bacteriophages, specifically the Salmonella‐targeted preparation SalmoFresh, retained the bactericidal effectiveness of individual interventions, and in some cases, achieved substantially increased efficacy. Additionally, the bacterial microbiomes of farm fresh and organic produce were less affected after phage treatment compared to PAA and chlorine.
Finally, our study revealed that resistance rates against SalmoFresh were relatively minor and unaffected by the stresses introduced after chemical washes and/or bacteriophage treatment.
Treatment of fresh produce with a salmonella-targeted bacteriophage cocktail is compatible with chlorine or peracetic acid and more consistently preserves the microbial community on produce, 10 January 2020
Escherichia coli O157:H7 (EcO157) infections have been recurrently associated with produce. The physiological state of EcO157 cells surviving the many stresses encountered on plants is poorly understood. EcO157 populations on plants in the field generally follow a biphasic decay in which small subpopulations survive over longer periods of time. We hypothesized that these subpopulations include persister cells, known as cells in a transient dormant state that arise through phenotypic variation in a clonal population.
Using three experimental regimes (with growing, stationary at carrying capacity, and decaying populations), we measured the persister cell fractions in culturable EcO157 populations after inoculation onto lettuce plants in the laboratory. The greatest average persister cell fractions on the leaves within each regime were 0.015, 0.095, and 0.221%, respectively. The declining EcO157 populations on plants incubated under dry conditions showed the largest increase in the persister fraction (46.9-fold). Differential equation models were built to describe the average temporal dynamics of EcO157 normal and persister cell populations after inoculation onto plants maintained under low relative humidity, resulting in switch rates from a normal cell to a persister cell of 7.7 × 10−6 to 2.8 × 10−5 h−1. Applying our model equations from the decay regime, we estimated model parameters for four published field trials of EcO157 survival on lettuce and obtained switch rates similar to those obtained in our study. Hence, our model has relevance to the survival of this human pathogen on lettuce plants in the field. Given the low metabolic state of persister cells, which may protect them from sanitization treatments, these cells are important to consider in the microbial decontamination of produce.
IMPORTANCE Despite causing outbreaks of foodborne illness linked to lettuce consumption, E. coli O157:H7 (EcO157) declines rapidly when applied onto plants in the field, and few cells survive over prolonged periods of time. We hypothesized that these cells are persisters, which are in a dormant state and which arise naturally in bacterial populations. When lettuce plants were inoculated with EcO157 in the laboratory, the greatest persister fraction in the population was observed during population decline on dry leaf surfaces. Using mathematical modeling, we calculated the switch rate from an EcO157 normal to persister cell on dry lettuce plants based on our laboratory data. The model was applied to published studies in which lettuce was inoculated with EcO157 in the field, and switch rates similar to those obtained in our study were obtained. Our results contribute important new knowledge about the physiology of this virulent pathogen on plants to be considered to enhance produce safety.
Formation of Escherichia coli O157:H7 persister cells in the lettuce phyllosphere and application of differential equation models to predict their prevalence on lettuce plants in the field
08 November 2019
Applied and Environmental Microbiology
Daniel S. Munther, Michelle Q. Carter, Claude V. Aldric, Renata Ivanek, Maria T. Brandl
The objective of this study was to identify food safety risk factors associated with supermarket trolleys (grills and handles) and handheld baskets.
Indicator microorganisms evaluated were those detected by aerobic plate count (APC), yeast and molds (YM), Enterobacteriaceae (EB). Environmental listeria (EL), coliforms (CF), and E. coli (EC). In addition, listeria monocytogenes, staphylococcus aureus, Escherichia coli O157 and salmonella sp. Were tested for. Trolley grills (n=36) had 2.7 x 102 CFU/cm2. Trolley handles (n=36) had 2.7 x 106 of CF and 5.2 CFU/cm2 of YM. The bottom of handheld baskets (n=25) had 3.5 x 105 CFU/cm2 of CF and 5.07 CFU/cm2 of EC. S. aureus was found on 96% of the baskets, 50% of the trolley handles (18 out of 36 samples), and 42% of the trolleys’ grills. E. coli O157 was identified on 17% of baskets, 3% on trolley grills, and 3% on handles. Salmonella sp. was detected on 16% of baskets and 8% of trolley grills. L. monocytogenes was detected on 17% of the bottoms of handheld baskets but on none of the other samples.
These results suggest the need for implementation of sanitation programs to regularly clean trolleys and baskets, as well as for consumer education.
Microbial contamination of grocery shopping trolleys and baskets in west Texas, 2020
Food Protection Trends vol. 40 no. 1
Alexandra Calle, Breyan Montoya, Andrea English, and Mindy Brashears
More consumers are developing a taste for goat cheese, milk, and meat as they become aware of the high protein and great taste of these products. While U.S. goat producers are enjoying this steady trend, they remain focused on keeping their animals healthy, especially from scrapie—a fatal brain disease that affects goats and sheep.
“The goat industry is one of the fastest growing animal industries in agriculture,” says Stephen White, an Agricultural Research Service (ARS) geneticist. “Not too many years ago, there were only a few hundred thousand goats in the country.” But in January 2018, goats and kids totaled 2.62 million head.
Meat and dairy are the biggest markets, followed by mohair, but goats serve in other unique capacities, says ARS veterinary medical officer David Schneider. Goats are being used to manage weedy areas along highways, get rid of kudzu in the Southeast, and even mow lawns. They’re also used as pack animals to carry supplies through rugged areas.
For any of these businesses, a single outbreak of scrapie could be devastating.
There is no cure or treatment for scrapie, which is in the same family—transmissible spongiform encephalopathies (TSEs) or prion diseases—as mad cow disease. TSEs are rare degenerative brain disorders characterized by tiny holes that give the brain a “spongy” appearance.
Most often scrapie is transmitted through birth fluids to other goats and sheep, and it can remain infectious in the environment for many years. It was first recognized in sheep in Great Britain and other European countries more than 250 years ago and was first diagnosed in U.S. sheep in 1947 in a Michigan flock.
All animals that get scrapie die. But there is good news from ARS. White and Schneider, who both work at ARS’s Animal Disease Research Unit in Pullman, Washington, are the first to demonstrate by infectious disease challenge that goats with the S146 allele (a different form of a gene) are less susceptible to scrapie over a usual goat lifetime. They also tested the K222 allele in goats. Their research shows that goats with one copy of either the S146 or K222 allele did not develop scrapie after being challenged with infection at birth. The study was published in The Veterinary Journal in 2018.
“Commercial goats raised for either meat or milk age out of herd participation as milkers, dams of commercial offspring, or as sires by around 6 years of age,” White says. In this ongoing ARS research, goats with the resistance alleles have lived beyond this commercial lifetime—up to 7½ years—with no clinical disease and without getting sick.
The only countries considered to be scrapie free are Australia and New Zealand. Currently, if one goat is diagnosed with scrapie on a U.S. farm, all goats are quarantined for life or euthanized. “You couldn’t restock your operation with any susceptible animal,” White says. “The farmer’s operation would be over.”
This research is good news for both goat and sheep producers because it could help with eradication efforts. Before U.S. producers can take advantage of import and export markets, scrapie must be eradicated from the United States and meet the World Organisation for Animal Health (OIE) criteria for disease freedom.
Aristos Georgiou of News Week reports an international team of scientists has said that they may have identified the origin of mad cow disease. Known as bovine spongiform encephalopathy, the neurodegenerative disease destroys the brain and spinal cord in cattle, causing death.
Since BSE first appeared in the 1980s in the United Kingdom, scientists have tried to identify how the disease emerged, however, no one hypothesis has been confirmed.
For a study published in the journal Proceedings of the National Academy of Sciences, the team of scientists investigated the origins of BSE by injecting a particular variant of scrapie disease into mice which have been genetically modified with bovine DNA.
The researchers say that, unexpectedly, the injection of the scrapie strain into the genetically modified mice resulted in the propagation of classical mad cow disease prions. These prions are present in natural form in the scrapie variant.
This observation indicates that the illness could be transmitted between different species and that the modified mice could develop mad cow disease, according to the study.
Olivier Andreoletti, an author of the paper from the French National Institute for Agronomic Research (INRA,) told AFP that the modified mice are “a very good model, which works well in terms of knowing what would happen if one exposed cows to those prions.”
He noted that the results provide, for the first time, and “experimentally underpinned explanation” for the appearance of mad cow disease in the U.K. in the 1980s.
After emerging, the disease spread in cattle across Europe, North America and other regions of the globe. This process was exacerbated by the fact that cows were being given feed which contained tissue from other cows infected with the disease.
In other gross out news, a recent edition of barfblog recaps a CBSLA report about how the delivery guy from Ubereats might be munching on your fries or sipping your drink before those items are delivered to you. Think about that the next time you call DoorDash or Foodora.
