One of my best friends used to be a dairy farmer, and he would always say, I’m not eating at McDonald’s, could be one of my former cows.
Shiga toxin-producing Escherichia coli (STEC) are foodborne bacterial pathogens, with cattle a significant reservoir for human infection. This study evaluated environmental reservoirs, intermediate hosts and key pathways that could drive the presence of Top 7 STEC (O157:H7, O26, O45, O103, O111, O121 and O145) on pasture-based dairy herds, using molecular and culture-based methods.
A total of 235 composite environmental samples (including soil, bedding, pasture, stock drinking water, bird droppings and flies and faecal samples of dairy animals) were collected from two dairy farms, with four sampling events on each farm. Molecular detection revealed O26, O45, O103 and O121 as the most common O-serogroups, with the greatest occurrence in dairy animal faeces (> 91%), environments freshly contaminated with faeces (> 73%) and birds and flies (> 71%). STEC (79 isolates) were a minor population within the target O-serogroups in all sample types but were widespread in the farm environment in the summer samplings.
Phylogenetic analysis of whole genome sequence data targeting single nucleotide polymorphisms revealed the presence of several clonal strains on a farm; a single STEC clonal strain could be found in several sample types concurrently, indicating the existence of more than one possible route for transmission to dairy animals and a high rate of transmission of STEC between dairy animals and wildlife.
Overall, the findings improved the understanding of the ecology of the Top 7 STEC in open farm environments, which is required to develop on-farm intervention strategies controlling these zoonoses.
Investigation of on-farm transmission routes for contamination of dairy cows with top 7 Escherichia coli O-serogroups
Rapp & C. M. Ross & P. Maclean & V. M. Cave & G. Brightwell
Animal petting zoos and farm fairs provide the opportunity for children and adults to interact with animals, but contact with animals carries a risk of exposure to zoonotic pathogens and antimicrobial‐resistant bacteria.
The aim of this study was to assess the occurrence of Shiga toxin‐producing Escherichia coli (STEC), Salmonella, extended‐spectrum β‐lactamase (ESBL)‐producing Enterobacteriaceae and methicillin‐resistant Staphylococcus aureus (MRSA) in animal faeces from six animal petting zoos and one farm fair in Switzerland. Furthermore, hygiene facilities on the venues were evaluated.
Of 163 faecal samples, 75 contained stx1, stx2 or stx1/stx2 genes, indicating the presence of STEC. Samples included faeces from sika deer (100%), sheep (92%), goats (88%), mouflons (80%), camels (62%), llamas (50%), yaks (50%), pigs (29%) and donkeys (6%), whereas no stx genes were isolated from faeces of calves, guinea pigs, hens, ostriches, ponies, zebras or zebus. Salmonella enterica subsp. enterica serovar Stourbridge (S. Stourbridge) was detected in faecal samples from camels. A total of four ESBL‐producing E. coli strains were isolated from faeces of goats, camels and pigs. PCR and sequencing identified the presence of blaCTX‐M‐15 in three and blaCTX‐M‐65 in one E. coli. Antimicrobial resistance profiling using the disk diffusion method revealed two multidrug‐resistant (MDR) E. coli with resistance to ciprofloxacin, gentamicin and azithromycin, all of which are critically important drugs for human medicine. Multilocus sequence typing identified E. coli ST162, E. coli ST2179, extraintestinal high‐risk E. coli ST410 and E. coli ST4553, which belongs to the emerging extraintestinal clonal complex (CC) 648. No MRSA was detected.
On all animal petting venues, there were inadequacies with regard to access to hygiene information and handwashing hygiene facilities. This study provides data that underscore the importance of hygiene measures to minimize the risk of transmission of zoonotic pathogens and MDR, ESBL‐producing E. coli to visitors of animal petting venues.
Animal petting zoos as sources of shiga toxin-producing Escherichia coli, salmonella and extended-spectrum Beta-lactamase (EXBL)-producing Enterobacteriaceae
Chris Koger of The Packer writes the U.S. Centers for Disease Control and Prevention has added 16 more people to an E. coli outbreak investigation of unknown origin, bringing the total to 39. Cases have been reported in 18 states; there have been no deaths.
According to the CDC’s Nov. 23 update, “Of the 22 ill people interviewed to date, all reported eating a variety of leafy greens, like spinach (16), romaine lettuce (15), iceberg lettuce (12), and mixed bag lettuce (8). No single type or brand of leafy greens or other food item has been identified as the source of this outbreak. CDC is not advising people avoid any particular food at this time.
Dole Fresh Vegetables, Inc. is voluntarily recalling a limited number of cases of organic romaine hearts. The products being recalled are Dole™ Organic Romaine Hearts 3pk (UPC 0-71430-90061-1), combined English/French packaging, with Harvested-On dates of 10-23-20 and 10-26-20, and Wild Harvest Organic Romaine Hearts (UPC 7-11535-50201-2), with Harvested-On dates of 10-23-20 and 10-26-20. The recall is being conducted due to a possible health risk from E. coli in the two products. Dole Fresh Vegetables is coordinating closely with regulatory officials. No illnesses have been reported to date in association with the recall.
Pathogenic E. coli can cause diarrhea, severe stomach cramps and vomiting. Most people recover within a week, but some illnesses can last longer and can be more severe.
This precautionary recall notification is being issued due to an isolated instance in which a package of Dole™ Organic Romaine Hearts – 3pk yielded a positive result for pathogenic non-O157 E.coli STEC in a routine sample collected at a retail store by the Michigan Department of Agriculture and Rural Development. There is no indication at this time that this positive result is related to any illnesses nor consumer complaints and it is not associated with the strains connected to the ongoing outbreaks currently under regulatory investigation.
I tell people that spices like cilantro are a significant source of dangerous E. coli and they look at me like I just fell off the turnip truck.
This study sought to model the growth and die-off of Escherichia coli (E. coli) O157:H7 along the cilantro supply chain from farm-to-fork to investigate its risk to public health. Contributing factors included in the model were on farm contamination from irrigation water and soil, solar radiation, harvesting, and transportation and storage times and temperatures.
The developed risk model estimated the microbiological risks associated with E. coli O157:H7 in cilantro and determined parameters with the most effect on the final concentration per serving for future mitigation strategies. Results showed a similar decrease in the E. coli O157:H7 (median values) concentrations along the supply chain for cilantro grown in both winter and summer weather conditions. With an estimated 0.1% prevalence of E. coli O157:H7 contamination for cilantro post-harvest used for illustration, the model predicted the probability of illness from consuming fresh cilantro as very low with fewer than two illnesses per every one billion servings of cilantro (1.6 x 10-9; 95th percentile). Although rare, 3.7% and 1.6% of scenarios run in this model for summer and winter grown cilantro, respectively, result in over 10 cases per year in the United States.
This is reflected in real life where illnesses from cilantro are seen rarely but outbreaks have occurred. Sensitivity analysis and scenario testing demonstrated that ensuring clean and high quality irrigation water and preventing temperature abuse during transportation from farm to retail, are key to reducing overall risk of illness.
Evaluation of public health risk for Escherichia coli O157:H7 in cilantro, 16 July 2020
In this study, the persistence of toxigenic Escherichia coli (E. coli ) on dried chamomile, peppermint, ginger, cinnamon, black and green teas stored under 4, 10, and 25°C was determined.
The E. coli survival rate in ginger and cinnamon teas decreased below 0 on Day 5. In the other tested teas, E. coli survivability showed a downward trend over time, but never dropped to 0. Chamomile tea retained the greatest population of viable E. coli . Meanwhile, die‐off of E. coli was higher at 25°C compared to lower temperatures. Additionally, fate of E. coli during brewing at 60, 70 and 80°C was evaluated.
The E. coli population was reduced to below 2 Log colony forming units (CFU)/g after 1 min at 80°C, At the same time, the E. coli survival at 60°C was higher than that at 70°C in all tested teas. The data indicated that if E. coli survives after storage of prepared teas, it may also survive and grow after the brewing process, especially if performed using temperatures <80°C. Finally, we analyzed the correlations between temperature, time, tea varieties and E. coli survival, and successfully constructed a random forest regression model. The results of this study can be used to predict changes in E. coli during storage and fate during the brewing process. Results will form the basis of undertaking a risk assessment.
Survival of toxigenic Escherichia coli on chamomile, peppermint, green, black, ginger, and cinnamon teas during storage and brewing, 23 June 2020
In August 2018, Public Health England (PHE) was made aware of five probable cases of Shiga toxin‐producing Escherichia coli (STEC) O157:H7 among individuals reporting participation in a mud‐based obstacle race. An additional four cases, identified via routine whole‐genome sequencing, were subsequently linked to the same event. Two of the nine cases were due to secondary household transmission.
Despite an agreement between the event organizers and the local authority, to ensure that all livestock were removed from the site 28 days before the event, sheep were observed grazing on some of the routes taken by the runners 2 days prior to the race taking place. A retrospective review of incidents reported to PHE between 2015 and 2018 identified 41 cases of gastroenteritis associated with muddy assault course events. Of these, 25 cases were due to infection with STEC O157:H7, of which all but one were associated with outbreaks.
Due to the environment in which such events take place, it is impossible to entirely remove the risk of exposure to potentially pathogenic zoonoses. However, race organizers should ensure that livestock are removed from the course 28 days before the event. They should also ensure that participants are made aware of the risk of contracting gastrointestinal disease from the environment, and to stress the importance of hand hygiene post‐event and the risk of secondary transmission, particularly to children who are at risk of developing haemolytic uraemic syndrome.
An outbreak of shiga toxin-producing Escherichia coli O157:H7 linked to a mud-based obstacle course, England, August 2018
SUMMARY: The Food Safety and Inspection Service (FSIS) is announcing plans to expand its routine verification testing for six Shiga toxin-producing Escherichia coli (non-O157 STEC; O26, O45, O103, O111, O121, or O145) that are adulterants, in addition to the adulterant Escherichia coli (E. coli) O157:H7, to ground beef, bench trim, and raw ground beef components other than raw beef manufacturing trimmings (i.e., head meat, cheek meat, weasand (esophagus) meat, product from advanced meat recovery (AMR) systems, partially defatted chopped beef and partially defatted beef fatty tissue, low temperature rendered lean finely textured beef, and heart meat)(hereafter “other raw ground beef components”) for samples collected at official establishments. STEC includes non-O157 STEC; O26, O45, O103, O111, O121, or O145, that are adulterants, and E. coli O157:H7. Currently, FSIS tests only its beef manufacturing trimmings samples for these six non-O157 STEC and E. coli O157:H7; all This document is scheduled to be published in the Federal Register on 06/04/2020 and available online at federalregister.gov/d/2020-12073, and on govinfo.gov 2 other aforementioned raw beef products are presently tested for E. coli O157:H7 only.
FSIS also intends to test for these non-O157 STEC in ground beef samples that it collects at retail stores and in applicable samples it collects of imported raw beef products. FSIS is requesting comments on the proposed sampling and testing of ground beef, bench trim, and other raw ground beef components. FSIS will announce the date it will implement the new testing in a subsequent Federal Register notice. Additionally, FSIS is responding to comments on the November 19, 2014, Federal Register notice titled “Shiga Toxin Producing Escherichia coli (STEC) in Certain Raw Beef Products.” FSIS is also making available its updated analysis of the estimated costs and benefits associated with the implementation of its non-O157 STEC testing on raw beef manufacturing trimmings and the costs and benefits associated with the expansion of its non-O157 STEC testing to ground beef, bench trim, and other raw ground beef components.
The Victorian government quickly banned the sale of so-called bath milk, which although labeled as not fit for human consumption, was a widely recognized way for Australian consumers to access raw milk.
What followed was a despicable whisper campaign that the child who died had an underlying medical condition, it wasn’t Shiga-toxin producing E. coli (STEC), farmers were losing access to lucrative markets – anything but the basic and sometimes deadly biology of STECs and everything involving fantasy and fairytales.
The milk was ‘raw’, or unpasteurised, and Ms Jones’ Mountain View Dairy Farm had been selling it as bath milk — a cosmetic product labelled ‘not fit for drinking’.
Ms Jones said she told the officer she would immediately remove the milk from the shelves of local stores.
“And he said to me, ‘No, no, no, don’t do that. You’ve done nothing wrong and all your labelling is right’.”
In hindsight, Ms Jones said this response “was really bizarre” — as was the decision to wait months before telling her about the cases.
But then the health officer told her a three-year-old boy had died after drinking the bath milk.
“It was the most devastating news that you could possibly imagine ever getting,” she said.
“I was mortified, we were doing the raw milk because people wanted it.”
Or because you contributed to promoting BS.
A Gippsland MP, the father of the child who died, and evidence presented to the coroner have all questioned how the cases were managed and suggested other contributing factors were overlooked.
Mark Wahlqvist, an Emeritus professor of medicine at Monash University and former president of the international union of nutrition sciences, said, “Raw milk, unpasteurised milk, is not safe enough to be in the public domain.”
Professor Wahlqvist said he was open to new research but at present, found campaigners for raw milk to be more than unconvincing.
“When people for conspiratorial reasons rather than scientific reasons, think that vaccination is a problem or that pasteurisation is a problem,” he said.
“We have a science communication problem in this country and it needs science leaders.”
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