Category Archives: STEC

Research – Prevalence and Epidemiology of Non-O157 Escherichia coli Serogroups O26, O103, O111, and O145 and Shiga Toxin Gene Carriage in Scottish Cattle, 2014–2015

ASM

ABSTRACT

Cattle are a reservoir for Shiga toxin-producing Escherichia coli (STEC), zoonotic pathogens that cause serious clinical disease. Scotland has a higher incidence of STEC infection in the human population than the European average. The aim of this study was to investigate the prevalence and epidemiology of non-O157 serogroups O26, O103, O111, and O145 and Shiga toxin gene carriage in Scottish cattle. Fecal samples (n = 2783) were collected from 110 herds in 2014 and 2015 and screened by real-time PCR. Herd-level prevalence (95% confidence interval [CI]) for O103, O26, and O145 was estimated as 0.71 (0.62, 0.79), 0.43 (0.34, 0.52), and 0.23 (0.16, 0.32), respectively. Only two herds were positive for O111. Shiga toxin prevalence was high in both herds and pats, particularly for stx2 (herd level: 0.99; 95% CI: 0.94, 1.0). O26 bacterial strains were isolated from 36 herds on culture. Fifteen herds yielded O26 stx-positive isolates that additionally harbored the intimin gene; six of these herds shed highly pathogenic stx2-positive strains. Multiple serogroups were detected in herds and pats, with only 25 herds negative for all serogroups. Despite overlap in detection, regional and seasonal effects were observed. Higher herd prevalence for O26, O103, and stx1 occurred in the South West, and this region was significant for stx2 at the pat level (P = 0.015). Significant seasonal variation was observed for O145 prevalence, with the highest prevalence in autumn (P = 0.032). Negative herds were associated with Central Scotland and winter. Herds positive for all serogroups were associated with autumn and larger herd size and were not housed at sampling.

IMPORTANCE Cattle are reservoirs for Shiga toxin-producing Escherichia coli (STEC), bacteria shed in animal feces. Humans are infected through consumption of contaminated food or water and by direct contact, resulting in serious disease and kidney failure in the most vulnerable. The contribution of non-O157 serogroups to STEC illness was underestimated for many years due to the lack of specific tests. Recently, non-O157 human cases have increased, with O26 STEC of particular note. It is therefore vital to investigate the level and composition of non-O157 in the cattle reservoir and to compare them historically and by the clinical situation. In this study, we found cattle prevalence high for toxin, as well as for O103 and O26 serogroups. Pathogenic O26 STEC were isolated from 14% of study herds, with toxin subtypes similar to those seen in Scottish clinical cases. This study highlights the current risk to public health from non-O157 STEC in Scottish cattle.

USA – New E. coli O145:H28 Outbreak Sickens 15; Little Information Provided

Food Poisoning Bulletin

new E. coli O145:H28 outbreak has been posted on the FDA’s CORE Investigation outbreak table. This new outbreak has sickened at least 15 people. There is no more information provided, which is typical for a posting on that table. The FDA only gives out more information about these outbreaks when they believe there are actionable steps that consumers can take to protect themselves, such as a recall.

USA – Notes from the Field: Multistate Outbreak of Escherichia coli O26 Infections Linked to Raw Flour — United States, 2019

CDC

On February 20, 2019, PulseNet, the molecular subtyping network for foodborne disease surveillance, identified six Shiga toxin–producing Escherichia coli (STEC) O26:H11 infections with the same pulsed-field gel electrophoresis (PFGE) pattern combination. This PFGE pattern combination matched that of infections from a July 2018 outbreak that was associated with ground beef. In response, CDC initiated an investigation with federal, state, and local partners to identify the outbreak source and implement prevention measures.

CDC defined a case as STEC O26 infection with an isolate matching the outbreak strain by PFGE or related by core genome multilocus sequence typing scheme (cgMLST), with dates of illness onset during December 11, 2018–May 21, 2019. Investigators initially hypothesized that ground beef was the outbreak cause because of the PFGE match to the July 2018 outbreak and because in early interviews, patients commonly reported eating ground beef and leafy greens. Investigators used cgMLST to compare the genetic sequences of isolates from both outbreaks and determined that they fell into separate genetic clades (differing by 6–11 alleles), suggesting that something other than ground beef caused the illness in 2019. CDC noted that one patient consumed raw cookie dough and that most patients were young adult females, similar to demographic distributions of past flour-associated STEC outbreaks (13). Investigators developed a supplemental questionnaire focusing on beef, leafy greens, and flour exposures.

Twenty-one cases were reported from nine states (Figure). The median age of patients was 24 years (range = 7–86 years); 71% were female. Three patients were hospitalized, and none died. Among 13 patients asked about flour exposures, six reported eating, licking, or tasting raw homemade dough or batter during the week before illness onset. Three patients reported eating raw dough or batter made with the same grocery store brand of all-purpose flour, including a patient who reported eating raw dough at a bakery in Rhode Island. Overall, of 18 patients with store information, 11 reported shopping at this same grocery store chain.

The Rhode Island Department of Health visited the bakery reported by the patient and collected flour for testing. On May 21, 2019, testing identified STEC O26 from an intact bag of all-purpose flour, which was the same grocery store brand reported by other patients. PulseNet confirmed that the STEC O26 isolated from the flour was highly related to clinical isolates using cgMLST (0–1 alleles). Product distribution records collected by the Food and Drug Administration indicated that the store brand flour purchased by six patients in three states was produced in a single milling facility in Buffalo, New York. Based on results of the investigation, the store chain recalled all lots of product from its retail locations in 11 states. The milling company also recalled all lots of this product and several other lots of flour produced in that facility, resulting in the recall of additional brands and products distributed to multiple states.

Flour is increasingly recognized as a cause of STEC outbreaks (15). Raw flour is not a ready-to-eat product, and this outbreak highlights the continuing risk for illness associated with consumption of flour and raw dough or batter. The investigation was aided by considering demographic information early in the investigation because these characteristics were similar to those in past flour-associated outbreaks (13). These similarities, coupled with the discriminatory power of cgMLST, helped to guide the consideration of alternative hypotheses regarding the outbreak source and the successful identification of flour as the cause of this outbreak.

Research – Outbreak of Shiga toxin-producing Escherichia coli O157 linked with consumption of a fast-food product containing imported cucumbers, United Kingdom, August 2020

IJID Online

Background

In August 2020, an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 occurred in the United Kingdom. Whole genome sequencing revealed these cases formed a genetically distinct cluster.

Methods

Hypotheses generated from case interviews were tested in analytical studies, and results informed environmental sampling and food chain analysis. A case-case study used non-outbreak ‘comparison’ STEC cases; a case-control study used a market research panel to recruit controls.

Results

A total of 36 cases were identified; all cases reported symptom onset between 3rd and 16th August 2020. The majority of cases (83%) resided in the Midlands region of England or Wales. A high proportion of cases reported eating out, with one fast-food restaurant chain mentioned by 64% (n = 23) of cases. Both case-case (adjusted odds ratio (aOR) 31.8, 95% confidence interval (CI) 1.6 – 624.9) and case-control (aOR 9.19, 95% CI 1.0 – 82.8) studies provided statistically significant results that consumption of a specific fast-food product was independently associated with infection.

Research – Survival of Salmonella and Shiga Toxin-producing Escherichia coli and Changes in Indigenous Microbiota During Fermentation of Kombucha Made from Home-brewing Kits

Journal of Food Protection

Survival and growth of Salmonella and Shiga toxin-producing Escherichia coli (STEC) in kombucha prepared from four brands of commercially available kombucha kits intended for use by home brewers were investigated. Changes in microbiota responsible for fermentation were also determined. An initial population of Salmonella (6.77 log CFU/mL) decreased to below the detection limit (0.30 log CFU/mL) within 10 d in kombucha prepared from two of the four test brands. Populations of 1.85 and 1.20 log CFU/mL were detected in two brands fermented for 14 d. An initial population of STEC (7.02 log CFU/mL) decreased to <0.30 log CFU/mL in two of the four brands within 14 d; 0.20 and 0.87 log CFU/mL were detected in kombucha prepared from the other two brands. Salmonella and STEC increased in populations within 1 d in three brands of base tea used to prepare kombucha, and were stable throughout 14 d of incubation. Both pathogens steadily declined in base tea prepared from one brand of kombucha kit. Inactivation of the pathogens occurred as the pH of kombuchas decreased, but a clear correlation between rates of inactivation and decrease in pH was not evident when comparing kombuchas prepared from the four kits. Growth and peak populations of mesophilic aerobic microorganisms, yeasts, lactic acid bacteria, and acetic acid bacteria varied, depending on the kombucha kit brand. There was not strong evidence to correlate the behavior of Salmonella and STEC with any of these groups of indigenous microbiota. Results of this study show that the ability of Salmonella and STEC to survive in kombucha and base tea used to prepare kombucha is dependent on inherent differences in commercially available kombucha kits intended for use in home settings. Strict application of hygienic practices with the goal of preventing contamination with Salmonella or STEC is essential for reducing the risk of illness associated the consumption of kombucha.

RASFF Alerts – STEC E.coli -Chilled Lamb Meat – Chilled Lamb Chops

RASFF-Logo

RASFF

shigatoxin-producing Escherichia coli (stx2+, eae+, /25g) in chilled lamb meat from New Zealand in Italy

RASFF

shigatoxin-producing Escherichia coli (stx1 + stx2 /25g) in chilled lamb chops from Belgium in the Netherlands

Switzerland – Pathogenic bacteria in food

BLV

The main pathogenic bacteria in food are Campylobacter and Salmonella. But Listeria in cheese and enterohemorrhagic Escherichia coli (ECEH) bacteria in young shoots have also made headlines in recent years.

Räucherfisch

Current

Smoked fish, what are the health risks?

04/16/2021 – Smoked fish are popular specialties in Switzerland. Consumed without cooking, they can become a food safety concern if hygiene rules are not respected during processing.

An assessment of the dietary risks associated with smoked fish was carried out as part of a pilot study in collaboration with the Office for Consumer Affairs of the canton of Vaud.

The study did not reveal any major risk, but follow-up should be ensured in order to maintain a high level of food safety and quality. The cantonal authorities concerned will keep this topic in their monitoring program and the FSVO plans to carry out a more detailed assessment.

Eingefärbtes rasterelektronisches Bild von Campylobacter jejuni

The prevention of infections with food germs of bacterial origin requires careful observance of simple hygiene rules in the kitchen .

Likewise, it is very important to wash your hands after coming into contact with animal products, as Campylobacter, Salmonella, Listeria and EHEC are transmitted from animals to humans. These diseases are called zoonoses.

Campylobacter

Infection with Campylobacter bacteria is the most common zoonosis in Switzerland, as in other European countries. It is the cause of gastrointestinal diseases in humans. The illness can last for about a week and in some circumstances may require hospitalization.

Campylobacter infection is characterized by abdominal pain, watery or bloody diarrhea, and an increase in temperature. Vomiting and high fever can also occur.

Infection is caused by contaminated food that has not been sufficiently cooked before consumption or that has come into direct contact with animals. In southern countries, contaminated water sources also represent a significant risk. The main source of infection, however, remains poultry meat.

According to data from the Federal Office of Public Health (OFSP), there are around 1,000 cases of Campylobacter infections each year. All patients do not consult their doctor, this figure is actually much higher. Overall, the number of cases has grown steadily over the past few years to reach around 7,500 during the year 2014.

Prevent Campylobacter infections

Campylobacter bacteria can survive in food, but cannot multiply there. Since contamination by Campylobacter does not affect foodstuffs, it is not possible to identify their presence by smell or appearance.

Campylobacter can be safely eliminated by thoroughly cooking the food at 70 ° C for at least 2 minutes by roasting, cooking or pasteurization. Freezing the food reduces the number of Campylobacter, without eliminating them completely.

Salmonella

Salmonella infection is most often manifested by inflammatory bowel disease with sudden onset of diarrhea, nausea, vomiting, fever, headache and abdominal pain. Salmonella infections are subject to notification .

They usually occur by ingesting contaminated food. The danger comes mainly from poultry, eggs, egg preparations, unpasteurized milk and meat products. Contamination through other animal products, utensils used, water, humans, etc. can occur throughout the food manufacturing process.

Prevent salmonellosis  

Salmonella infections are fought on two levels:

  1. the number of infected domestic animals should be reduced; 
  2. contamination of food with salmonella must be avoided and their multiplication stopped.

Listeria

In people without weakened immune systems, a Listeria infection is usually accompanied by mild symptoms or even no symptoms at all. People who are immunocompromised can experience a variety of serious symptoms, the outcome of which can be fatal. During pregnancy, a Listeria infection can lead to miscarriage or cause a child to have sepsis or meningitis when it is born.

Listeria transmission is caused by the ingestion of contaminated raw food, mainly of animal origin: meat, smoked fish, cold cuts, soft cheese. Transmission through contact with infected animals is rarer.

Prevent listeriosis  

In the first place, the general rules of hygiene should be observed when in contact with food and animals. Pregnant women and people with weakened immune systems should in particular avoid raw vegetables, raw or undercooked meat as well as raw fish and seafood, soft cheese and cheese made from unpasteurized milk. .

Enterohemorrhagic Escherichia coli (EHEC)

The majority of people infected with EHEC have abdominal pain accompanied by cramping, a short-term fever followed by intestinal colic which becomes violent, and slightly bloody hemorrhagic diarrhea. In a minority of people, only watery diarrhea is observed. Cases of EHEC infections are very rare in Switzerland. The mortality rate reaches 3 to 5%.

Escherichia coli bacteria naturally belong to our intestinal flora. EHECs are a pathogenic line of these generally harmless bacteria. Infection occurs first by consuming contaminated animal foods, mainly undercooked ground beef and unpasteurized dairy products. Contaminated drinking water, young shoots, potatoes and unpasteurized apple juice can, for example, also contain EHEC. More rarely, cases of transmission of EHEC are observed through contact with animals or animal faeces.

Prevent EHEC infections

Since a very small number of infectious agents is enough to get sick, it is important to follow the general rules of hygiene. It is therefore strongly recommended to wash your hands thoroughly after having been in contact with animals and to cook the meat thoroughly when preparing meals. Raw food should always be stored in the refrigerator.

Further information

USA – JBS USA Food Company Recalls Imported Boneless Beef Products Due to Possible E. coli O157:H7 Contamination

USDA

JBS USA Food Company, a Greeley, Colo. firm and Importer of Record, is recalling approximately 4,860 pounds of imported boneless beef products that may be contaminated with E. coli O157:H7, the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) announced today.

The raw, frozen, boneless beef products were imported on or around Nov. 10, 2020 and distributed for further processing. The following products are subject to recall [View Label (PDF Only)]:

  • 60-lb. cardboard boxes containing “95CL BONELESS BEEF PRODUCT OF AUSTRALIA” with “PACKED ON: 02-SEP-20” and Australian “EST. 4” on the packaging label.

The products were shipped to distributors and further processors in New York and Pennsylvania.

The problem was discovered when FSIS collected a routine product sample that confirmed positive for the presence of E. coli O157:H7. There have been no confirmed reports of adverse reactions due to consumption of these products.

Anyone concerned about an illness should contact a healthcare provider. E. coli O157:H7 is a potentially deadly bacterium that can cause dehydration, bloody diarrhea and abdominal cramps 2–8 days (3–4 days, on average) after exposure the organism. While most people recover within a week, some develop a type of kidney failure called hemolytic uremic syndrome (HUS). This condition can occur among persons of any age but is most common in children under 5-years old and older adults. It is marked by easy bruising, pallor, and decreased urine output. Persons who experience these symptoms should seek emergency medical care immediately.

FSIS is concerned that some product may be frozen and in cold storage at distributor or further processor locations. Distributors and further processors who received these products are urged not to utilize them.

FSIS routinely conducts recall effectiveness checks to verify recalling firms notify their customers of the recall and that steps are taken to make certain that the product is no longer available to consumers. When available, the retail distribution list(s) will be posted on the FSIS website at www.fsis.usda.gov/recalls.

FSIS advises all consumers to safely prepare their raw meat products, including fresh and frozen, and only consume whole cuts of beef that have been cooked to a temperature of 145 °F with a 3-minute rest time and ground beef to 160 °F. The only way to confirm that beef is cooked to a temperature high enough to kill harmful bacteria is to use a food thermometer that measures internal temperature, https://www.fsis.usda.gov/safetempchart.

Consumers with questions about the recall can contact Mr. Kim Holzner, Head of JBS Imports, at Kim.Holzner@jbssa.com. Members of the media with questions about the recall can contact Ms. Nikki Richardson, Director of Communications for JBS USA Food Company, at Nikki.Richardson@jbssa.com.

Research – An Overview of Traceback Investigations and Three Case Studies of Recent Outbreaks of Escherichia coli O157:H7 Infections Linked to Romaine Lettuce

Journal of Food Protection

Eurofins Food Testing UK

Leafy greens contaminated with Shiga toxin-producing Escherichia coli (STEC) have continued to cause foodborne illness outbreaks in recent years and present a threat to public health. An important component of foodborne illness outbreak investigations is determining the source of the outbreak vehicle through traceback investigations. The Food and Drug Administration is home to traceback investigation experts that employ a standardized process to initiate, execute, and interpret the results of traceback investigations in collaboration with the Centers for Disease Control and Prevention and state and local partners. Traceback investigations of three outbreaks of STEC infections linked to romaine lettuce in 2018 and 2019 were examined to demonstrate challenges, limitations, and opportunities for improvement. The three outbreaks resulted in a total of 474 illnesses, 215 hospitalizations, and five deaths. These illnesses were linked to the consumption of romaine lettuce from three distinct growing regions in Arizona and California. Some of the challenges encountered included the time it took to initiate a traceback, limited product-identifying information throughout the supply chain, lack of interoperability in record keeping systems, and co-mingling of product from multiple suppliers. These challenges led to time delays in the identification of the farm source of the leafy greens and the inability to identify the root cause of contamination. Implementation of technology enabled traceability systems, testing of these systems, and future regulations to incentivize adoption of traceability systems are some of the initiatives that will help address these challenges by improving traceback investigations and ultimately preventing foodborne illnesses and future outbreaks from occurring.

RASFF Alert – STEC E.coli – Chilled Bovine Meat

European Food Alerts

RASFF

shigatoxin-producing Escherichia coli (eae+, Stx1-, Stx2+ /25g) in chilled bovine meat from Slovenia in Sloveniafood