Tahini is a common food product in the Mediterranean area that is used as a main ingredient in variety of ready-to-eat foods. The objective of the current study was to investigate the inhibitory effect of thyme oil (TO) or cinnamon oil (CO) on E. coli O157:H7 viability in tahini and diluted tahini at different storage temperatures.
Addition of 2.0% CO to tahini reduced E. coli O157:H7 numbers by 1.38, 1.79 or 2.20 log10 CFU/mL at 10, 25 or 37 °C, respectively, by 28d. In diluted tahini at 10 °C, no viable cells of E. coli O157:H7 by 21d were detected when 1.0% CO was used. However, at 25 and 37 °C, no viable cells were detected by 14d when CO was added at 0.5% level. Addition of 2.0% TO to tahini, resulted in 1.82, 2.01 or 1.65 log10 CFU/mL reduction in E. coli O 157:H7 numbers was noted at 37, 25 or 10 °C, respectively, by 28d. In diluted tahini, TO at 0.5% or 1.0% induced complete reduction in the viability of E. coli O157:H7 by 28d storage at 37 or 25 °C. At 10 °C, a 3.02 log10 CFU/mL reduction was observed by 28d compared to the initial inoculation level in samples treated with 2.0% TO.
Inhibitory effect of thyme and cinnamon essential oils against e. coli O157:H7 in tahini, 08 May 2020
Food Science and Technology
Anas Al-Nabulsi, Tareq Osaili, Amin Olaimat, Weam Almarsi, Murad Al-Holy, Ziad Jaradat, Mutamed Ayyash, Saddam Awaisheh, Richard Holley
Jimmy John’s LLC reported that all of its restaurants stopped serving clover sprouts on February 24, 2020.
People usually get sick from Shiga toxin-producing E. coli (STEC) 1 to 10 days (average of 3 to 4 days) after swallowing the germ.
Symptoms vary, but often include severe stomach cramps, diarrhea (often bloody), and vomiting. Some people may have a fever, which usually is not very high (less than 101˚F/38.5˚C).
Some people with a STEC infection may get a type of kidney failure called hemolytic uremic syndrome (HUS).
Antibiotics are not recommended for patients with suspected E. coli infections until diagnostic testing can be performed and E. coli infection is ruled out. Some studies have shown that administering antibiotics to patients with E. coli infections might increase their risk of developing HUS, and a benefit of treatment has not been clearly demonstrated.
CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) investigated a multistate outbreak of E. coli O103 infections linked to clover sprouts.
Public health investigators used the PulseNet system to identify illnesses that were part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA fingerprinting is performed on E. coli bacteria isolated from ill people by using a standardized laboratory and data analysis method called whole genome sequencing (WGS). CDC PulseNet manages a national database of these sequences that are used to identify possible outbreaks. WGS gives investigators detailed information about the bacteria causing illness. In this investigation, WGS showed that bacteria isolated from ill people were closely related genetically. This means that people in this outbreak were likely to share a common source of infection.
A total of 51 people infected with the outbreak strain of E. coli O103 were reported from 10 states. A list of the states and the number of cases in each can be found on the Map of Reported Cases.
Illnesses started on dates ranging from January 6, 2020, to March 15, 2020. Ill people ranged in age from 1 to 79 years, with a median age of 29 years. Fifty-five percent of ill people were female. Of 41 ill people with information available, 3 were hospitalized and no deaths were reported.
Seventeen (63%) of 27 people interviewed reported eating sprouts at a Jimmy John’s restaurant. Jimmy John’s LLC reported that all of their restaurants stopped serving clover sprouts on February 24, 2020. Clover sprouts are no longer available at Jimmy John’s restaurants.
Additionally, FDA identified the outbreak strain of E. coli O103 in samples of Chicago Indoor Garden products that contain sprouts. On March 16, 2020, Chicago Indoor Garden recalledexternal icon all products containing red clover sprouts.
FDA’s traceback investigationexternal icon showed that a common seed lot was used to grow both the sprouts recalled by Chicago Indoor Garden and sprouts that were served at some Jimmy John’s locations. The same seed lot was also used to grow sprouts linked to an outbreakexternal icon of the same strain of E. coli O103 infections in 2019.
As of April 22, 2020, this outbreak appears to be over.
Enteroinvasive Escherichia coli (EIEC) and Shigella spp. are both Gram-negative bacteria causing diarrheal disease worldwide [1,2]. The clinical presentations of these two pathogens are very similar [3,4] and commonly manifested through diarrhoea, abdominal cramps, nausea and fever both in children and adults [5,6]. In addition to a similar clinical picture, EIEC and Shigella share laboratory features that can make it difficult to distinguish between them in routine clinical laboratory practice. Both pathogens are transmitted via the faecal-oral route and infections are frequently associated with consumption of contaminated food and water [7–10]. While Shigella is associated with large-scale food-borne outbreaks [11,12], outbreaks caused by EIEC are rarely recorded.
High prevalence of EIEC infections have been documented in rural areas and settings with poor sanitation in high-risk countries [5,13] while EIEC infections in Europe are typically sporadic and travel related . Nevertheless, a few EIEC outbreaks have been reported in Europe, with the most recent ones having occurred in Italy in 2012  and in the United Kingdom (UK) in 2014 . These outbreaks affected 109 cases and 157 probable cases, respectively, highlighting the fact that EIEC, like Shigella, has the capacity to cause large gastrointestinal disease outbreaks. The outbreak strain identified in these recent European outbreaks, EIEC O96:H19, is an emergent type of EIEC that has phenotypic characteristics more resembling those of non-invasive Escherichia coli (E. coli) than those described for Shigella . These characteristics are suggested to contribute to improved survival abilities as well as the ability to better adapt to different ecological niches .
Traditionally, culturing of faecal specimens has been the mainstay of laboratory diagnostics for enteric bacteria, and EIEC has been differentiated from Shigella by assessing a combination of several phenotypic characteristics, including biochemical, motility and serological traits [18,19]. This is now changing as PCR-based methods are becoming routine in many diagnostic laboratories . In contrast to non-invasive E. coli, EIEC and Shigella can invade and multiply in intestinal epithelial cells , a process that is partially mediated by the products of the invasion plasmid antigen (ipa) genes . For this reason, PCR targeting the ipaH gene can separate EIEC from other non-invasive E. coli, but cannot differentiate between EIEC and Shigella . The lacY gene has been proposed as an additional molecular marker for which most E. coli are positive and Shigella is negative . Its use as a PCR target in separating Shigella and EIEC is restricted to bacterial isolates since many faecal samples are lacY positive because of the presence of E. coli in the normal flora.
Which is considered too time consuming for most clinical laboratories. For this reason, it is likely that a patient with specimens that are ipaH PCR-positive but culture negative would not be notified as a case if the diagnostic algorithm at the laboratory requires a detected Shigella isolate. In addition, PCR is a more sensitive method than culturing  and Shigella is known for its limited survival ability in faecal samples , which also may lead to samples being ipaH PCR-positive but culture negative.
Shigellosis is notifiable by law in Sweden as in the majority of countries in Europe . In 2017, the incidence was 2.1 per 100,000 inhabitants in Sweden, and the majority of cases had been infected abroad . The mandatory reporting of diseases allows the implementation of a series of public health actions, including public health management and surveillance activities, and helps define risk exposures. In contrast to shigellosis, reporting is not mandatory for EIEC and the occurrence of this pathogen in Sweden is currently unknown.It requires additional laboratory procedures such as screening large numbers of colonies,
Outbreak of gastroenteritis highlighting the diagnostic and epidemiological challenges of enteroinvasive Escherichia coli, county of Halland, Sweden, November 2017, 12 December 2019
Shiga toxin-producing Escherichia coli (STEC) strains are important zoonotic foodborne pathogens, causing diarrhea, hemorrhagic colitis, and life-threatening hemolytic uremic syndrome (HUS) in humans. However, antibiotic treatment of STEC infection is associated with an increased risk of HUS. Therefore, there is an urgent need for early and effective therapeutic strategies.
Here, we isolated lytic T7-like STEC phage PHB19 and identified a novel O91-specific polysaccharide depolymerase (Dep6) in the C terminus of the PHB19 tailspike protein. Dep6 exhibited strong hydrolase activity across wide ranges of pH (pH 4 to 8) and temperature (20 to 60°C) and degraded polysaccharides on the surface of STEC strain HB10. In addition, both Dep6 and PHB19 degraded biofilms formed by STEC strain HB10.
In a mouse STEC infection model, delayed Dep6 treatment (3 h postinfection) resulted in only 33% survival, compared with 83% survival when mice were treated simultaneously with infection. In comparison, pretreatment with Dep6 led to 100% survival compared with that of the control group. Surprisingly, a single PHB19 treatment resulted in 100% survival in all three treatment protocols. Moreover, a significant reduction in the levels of proinflammatory cytokines was observed at 24 h postinfection in Dep6- or PHB19-treated mice. These results demonstrated that Dep6 or PHB19 might be used as a potential therapeutic agent to prevent STEC infection.
IMPORTANCE Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen worldwide. The Shiga-like toxin causes diarrhea, hemorrhagic colitis, and life-threatening hemolytic uremic syndrome (HUS) in humans. Although antibiotic therapy is still used for STEC infections, this approach may increase the risk of HUS. Phages or phage-derived depolymerases have been used to treat bacterial infections in animals and humans, as in the case of the “San Diego patient” treated with a phage cocktail. Here, we showed that phage PHB19 and its O91-specific polysaccharide depolymerase Dep6 degraded STEC biofilms and stripped the lipopolysaccharide (LPS) from STEC strain HB10, which was subsequently killed by serum complement in vitro. In a mouse model, PHB19 and Dep6 protected against STEC infection and caused a significant reduction in the levels of proinflammatory cytokines. This study reports the use of an O91-specific polysaccharide depolymerase for the treatment of STEC infection in mice.
A novel tail-associated O91-specific polysaccharide depolymerase from a podophage reveals lytic efficacy of shiga toxin-producing Escherichia coli, 28 February 2020
I’ll say it again, as a comic in all seriousness: Lettuce is overrated.
My favorite salad is a Greek one with all those veggies and no lettuce.
The U.S. Food and Drug Administration announced last week that between 2009 and 2018, FDA and the Centers for Disease Control and Prevention (CDC) identified 40 foodborne outbreaks of Shiga toxin-producing E. coli (STEC) infections in the U.S. with a confirmed or suspected link to leafy greens.
This is why The Tragically Hip were so great, and why they never appealed much beyond Canada.
I feel the same about academia.
And why Osterholm called me 15 years ago as a consultant for Fresh Express, and asked me how dare I the lettuce and skull picture, and I said because I can and it was fairly apt given there have been 40 outbreaks.
Holy shit (this is me echoing my John Oliver voice).
Coronavirus is just confirming: Go public, go often, go hard.
It’s the only way people will pay attention.
And as this story in the N.Y. Times points out, there have been spectacular public health failures by people who tell others, just shut the fuck up.
According to the FDA, it has an unwavering commitment to advancing the safety of fresh leafy greens. Leafy greens are among the most widely consumed vegetables and an important part of an overall healthy diet. While millions of servings are consumed safely every day, this produce commodity has been implicated too often in outbreaks of foodborne illness, and we believe that FDA, along with leafy greens sector stakeholders, can do more.
Between 2009 and 2018, FDA and Centers for Disease Control and Prevention (CDC) identified 40 foodborne outbreaks of Shiga toxin-producing E. coli (STEC) infections in the U.S. with a confirmed or suspected link to leafy greens. While most strains of E. coli are harmless, STEC can cause bloody diarrhea, anemia, blood-clotting problems, and kidney failure – conditions that are potentially life-threatening. The most common STEC, E. coli O157:H7, is the type most often associated with outbreaks.
Most leafy greens are grown outdoors, where they are exposed to soil, animals, and water, all of which can be a source of pathogen contamination. In addition, leafy greens are mostly consumed raw, without cooking or other processing steps to eliminate microbial hazards. The Produce Safety Rule under the FDA Food Safety Modernization Act (FSMA) sets science-based standards to help ensure that water, soil amendments (e.g., fertilizer or compost), food contact surfaces and other materials that touch produce during growing, harvesting, packing, and holding do not contribute to produce contamination. The Produce Safety Rule also addresses animal intrusion into fields and worker hygiene.
Due to the recurring nature of outbreaks associated with leafy greens, FDA has developed this commodity-specific action plan. What follows is an overview of the actions FDA plans to take in 2020 to advance work in three areas: (1) prevention, (2) response, and (3) addressing knowledge gaps.
Faculty members from the Kansas State University College of Veterinary Medicine have developed a faster, more efficient method of detecting “Shiga toxin-producing E. coli,” or STEC, in ground beef, which often causes recalls of ground beef and vegetables.
“The traditional gold standard STEC detection, which requires bacterial isolation and characterization, is not amenable to high-throughput settings and often requires a week to obtain a definitive result,” said Jianfa Bai, section head of molecular research and development in the Kansas State Veterinary Diagnostic Laboratory.
The new method developed by Bai and colleagues requires only a day to obtain confirmatory results using a Kansas State University-patented method with the partition-based multichannel digital polymerase chain reaction system.
“We believe the new digital polymerase chain reaction detection method developed in this study will be widely used in food safety and inspection services for the rapid detection and confirmation of STEC and other foodborne pathogens,” said Jamie Henningson, director of the Kansas State Veterinary Diagnostic Laboratory.
When ingested through foods such as ground beef and vegetables, STEC can cause illnesses with symptoms including abdominal pain and diarrhea. Some illnesses caused by STEC may lead to kidney failure and can be life-threatening.
“Some E. coli strains do not produce Shiga toxins and thus do not affect human health as much,” said Xuming Liu, research assistant professor. “Because cattle feces and ground beef can contain harmless or less pathogenic E. coli along with STEC, the most commonly used polymerase chain reaction cannot identify pathogenic E. coli strains in a complex sample matrix.”
The new digital polymerase chain reaction test was developed for research and food safety inspections that require shorter turnaround and high throughput, without sacrificing detection accuracy.
“While the current, commonly used testing method is considered to be the gold standard, it is tedious and requires many days to obtain results that adequately differentiate the bacteria,” said Gary Anderson, director of the International Animal Health and Food Safety Institute at the K-State Olathe campus.
The study, “Single cell-based digital PCR detection and association of Shiga toxin-producing E. coli serogroups and major virulence genes,” which describes the test design and results, was published in the Journal of Clinical Microbiology.
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
Chris Koger of The Packer reported in late Dec. 2019 that Sprouts Unlimited, Marion, Iowa, is recalling clover sprouts, which have been linked to a cluster of E. coli cases under investigation in Iowa.
The Iowa Department of Inspections and Appeals is investigating the link between the outbreak and the product from Sprouts Unlimited, according to a Dec. 27 recall notice from the company.
The sprouts were shipped to Hy-Vee and Fareway Foods stores, and Jimmy John’s restaurants.
The retail packs in the recall are in pint containers with a blue label on the lid, according to Sprouts Unlimited. The Universal Product Code is 7 32684 00013 6 is on the bottom right side of the label.
The Iowa Department of Inspections and Appeals told Sprouts Unlimited the sprouts are epidemiologically linked to the outbreak. More tests are being conducted to determine the source, according to the recall notice.
Nutritional and perceived health benefits have contributed to the increasing popularity of raw sprouted seed products. In the past two decades, sprouted seeds have been a recurring food safety concern, with at least 55 documented foodborne outbreaks affecting more than 15,000 people. A compilation of selected publications was used to yield an analysis of the evolving safety and risk communication related to raw sprouts, including microbiological safety, efforts to improve production practices, and effectiveness of communication prior to, during, and after sprout-related outbreaks. Scientific investigation and media coverage of sprout-related outbreaks has led to improved production guidelines and public health enforcement actions, yet continued outbreaks call into question the effectiveness of risk management strategies and producer compliance. Raw sprouts remain a high-risk product and avoidance or thorough cooking are the only ways that consumers can reduce risk; even thorough cooking messages fail to acknowledge the risk of cross-contamination. Risk communication messages have been inconsistent over time with Canadian and U.S. governments finally aligning their messages in the past five years, telling consumers to avoid sprouts. Yet consumer and industry awareness of risk remains low. To minimize health risks linked to the consumption of sprout products, local and national public health agencies, restaurants, retailers and producers need validated, consistent and repeated risk messaging through a variety of sources.
Several types of mettwurst, manufactured by a South Australian Company, have been recalled after it was discovered the products may be contaminated with harmful bacteria.
Wintulichs, based in Gawler, recalled their Metwurst Garlic 300g, 375g, 500g, 700g, Mettwurst Plain 700g and Mettwurst Pepperoni 375g products.
Food Standards Australia New Zealand say the products have been sold at Woolworths, IGA and independent stores across SA.
The recall is due to incorrect pH and water activity levels, which may lead to microbial contamination and could cause illness if consumed.
Customers should return the products to the place of purchase for a full refund.
In Australia and around the world, the incidence of reported foodborne illness is on the increase. Regularly cited estimates suggest that Australia is plagued with over two million cases of foodborne illness each year, costing the community in excess of $1 billion annually.
Based on the case studies cited here and a thorough examination of a variety of documents disseminated for public consumption, government and industry in Australia are well aware of the challenges posed by greater public awareness of foodborne illness. They are also well aware of risk communication basics and seem eager to enter the public fray on contentious issues. The primary challenge for government and industry will be to provide evidence that approaches to managing microbial foodborne risks are indeed mitigating and reducing levels of risk; that actions are matching words.
There is a further challenge in impressing upon all producers and processors the importance of food safety vigilance, as well as the need for a comprehensive crisis management plan for critical food safety issues.
On Feb. 1, 1995, the first report of a food poisoning outbreak in Australia involving the death of a child from hemolytic uremic syndrome (HUS) after eating contaminated mettwurst reached the national press. The next day, the causative organism was identified in news stories as E. coli 0111, a Shiga-toxin E. coli (STEC) which was previously thought to be destroyed by the acidity in fermented sausage products like mettwurst, an uncooked, semi-dry fermented sausage. By Feb. 3, 1995, the child was identified as a four-year-old girl and the number sickened in the outbreak was estimated at 21.
The manager of the company that allegedly produced the contaminated mettwurst had to hire security guards to protect his family home as threats continued to be made on his life, and the social actors began jockeying for position in the public discourse. The company, Garibaldi, blamed a slaughterhouse for providing the contaminated product, while the State’s chief meat hygiene officer insisted that meat inspections and slaughtering techniques in Australian abattoirs were “top class and only getting better.”
On Feb. 4, just three days after the initial, national report, the South Australian state government announced it was implementing new food regulations effective March 1, 1995. The federal government followed suit the next day, announcing intentions to bolster food processing standards and launching a full inquiry. Even the coroner investigating the death of the girl said on Feb. 9 that investigations relating to inquests usually took about three months to complete, but he would start the hearing the next day if possible.
By Feb. 6, 1995, Garibaldi Smallgoods declared bankruptcy. Sales of smallgoods like mettwurst were down anywhere from 50 to 100 per cent according to the National Smallgoods Council.
The outbreak of E. coli O111 and the reverberations fundamentally changed the public discussion of foodborne illness in Australia, much as similar outbreaks of STEC in Japan, the U.K. and the U.S. subsequently altered public perception, regulatory efforts and industry pronouncements in those countries. The pattern of public reporting and response followed a similar pattern of reporting on the medical implications of the illness, attempts to determine causation and finger pointing. Such patterns of reporting are valid; when people are sick and in some cases dying from the food they consume, people want to know why. The results altered both the scientific and public landscapes regarding microbial foodborne illness, and can inform future risk communication and management efforts.
In all, 173 people were stricken by foodborne illness linked to consumption of mettwurst manufactured by Garibaldi smallgoods. Twenty-three people, mainly children, developed HUS, and one died. Although sporadic cases of HUS had been previously reported, this was the first outbreak of this condition recognized in Australia.
Once public attention focused on Garibaldi as the source of the offending foodstuff, the company quickly deflected criticism, blaming an unnamed Victorian-based company of supplying contaminated raw meat, and citing historical precedent as proof of safety. Garibaldi’s administration manager Neville Mead was quoted as saying that he was confident hygiene and processing at the plant were up to standard, adding, “We stand by our processing. We’ve done this process now for 24 years and it’s proved successful.” Such blind faith in tradition, even in the face of changing science-based recommendations, even in the face of tragedy, is often a hallmark of outbreaks of foodborne illness, reflecting the deep cultural and social mythologies that are associated with food.
However, given the uncertainties at the time, a spokesman with the Australian Meat and Livestock Association appropriately rejected such allegations, saying, “I believe it is irresponsible of them (Garibaldi) to make that statement when there is absolutely no evidence of that at all.” Likewise, Victorian Meat Authority chairman John Watson said his officers were investigating Garibaldi’s claims, but that even if the raw meat had come from
Victoria, the supplier may not necessarily be the source of the disease, but rather it could be based in Garibaldi’s processing techniques.
Similarly, when Garibaldi accused the watchdog South Australian Health Commission of dragging its feet with investigations, Health Minister, Dr. Michael Armitage responded by publicly stating that, “They indicated to us that they wanted their lawyers first to be involved before they provided us with information (concerning the mettwurst). It was only (after) earlier this week, under the Food Act, we issued a demand for that information, that we got it. So indeed, I would put it to Garibaldi that the boot is completely on the other foot.”
Likewise, South Australia’s chief meat hygiene officer, Robin Van de Graaff rejected such claims, saying that, “These organisms are part of a large family of bugs that are normal inhabitants of the gut of farm animals … If a tragedy like this occurs it is usually because, and it no doubt is in this case, not because of a small amount of contamination at the point of slaughter but because of the method of handling and processing after that.” The statements of government regulators would be subsequently validated.