Category Archives: E.coli O111

Research – Shiga toxin-producing Escherichia coli (STEC) data: 2019


Main points for 2019

The main points of the 2019 report are:

1. A total of 539 confirmed cases of Shiga toxin-producing Echerichia coli (STEC) O157 were reported in England and Wales in 2019.

2. The lowest incidence of STEC O157 was in the East Midlands region (0.56 per 100,000 population) and the highest in the Yorkshire and Humber region (1.51 per 100,000 population).

3. Children aged 1 to 4 years had the highest incidence of infection (3.28 per 100,000 population, CI 95% 2.63–4.04).

4. Nearly one-third of confirmed STEC O157 cases in England were hospitalised and 3% were reported to have developed haemolytic ureamic syndrome (HUS).

5. In England and Wales, detection of non-O157 STEC increased in line with the growing number of NHS labs implementing gastrointestinal (GI) diagnostics using polymerase chain reaction (PCR); in 2019, 768 culture-positive non-O157 STEC cases (655 in England, 113 in Wales) were reported.

6. A further 347 specimens in England and 66 in Wales were positive for Shiga toxins (stx) genes on PCR at the Gastrointestinal Bacteria Reference Unit (GBRU) but an organism was not cultured.

7. The most commonly isolated non-O157 STEC serogroup was STEC O26 (England: n=109/655, 17% and Wales: n=28/113, 25%).

8. Five outbreaks of STEC involving 65 cases in England were investigated in 2019.

Cases of STEC in England and Wales in 2019

In 2019, 1,720 confirmed cases of STEC were reported in England and Wales; these comprised 539 culture-confirmed cases of STEC serogroup O157 (515 cases in England and 24 in Wales) and 768 cases (655 in England, 113 in Wales) where a serogroup other than O157 was isolated (non-O157). For a further 413 cases, samples were confirmed as STEC by testing positive by PCR for stx genes, but STEC was not cultured (347 in England, 66 in Wales).

Five confirmed cases were infected with multiple serogroups:

  • O157 and O26
  • O26 and O103
  • O76 and O113
  • O91 and O128ab
  • O146 and O91

There were 13 probable cases with serological evidence of STEC infection, with antibodies detected to O157 lipopolysaccharides in 11 cases (England: 10, Wales: 1), for O111 lipopolysaccharides in one case, and for O26 lipopolysaccharides in another case.

The crude incidence rate of confirmed STEC O157 in England and Wales was 0.91 per 100,000 cases (95% CI 0.83–0.99), continuing the downward trend observed since 2015 (Figure 1). It is the lowest number of cases reported annually since 1996, when testing began in England for STEC O157 on all faecal specimens from patients with suspected gastrointestinal infection (7).

Non-O157 STEC cases in England and Wales
Historically, cases of non-O157 STEC have been under ascertained, with 89 cases of STEC non-O157 reported between 2009 and 2013, prior to PCR being implemented.

Following the increase in recent years in frontline laboratories using PCR, there has been a significant increase in the detection of non-O157 STEC in England. It is not possible to estimate a denominator for incidence calculations for non-O157 STEC because details of contract arrangements for referral of samples from primary care and catchment areas of each diagnostic laboratory using PCR are not known.

In 2019, of 5,760 samples received at GBRU for STEC testing, 1,002 non-O157 STEC cases were confirmed in England. Of the 1,002 non-O157 cases, 655 culture positive cases of 72 different serogroups were confirmed. For 21 isolates, a serotype could not be identified as the genes encoding the somatic O antigen did not match any known sequence in the database. Specimens for a further 347 cases in England were positive for stx genes on PCR at GBRU but an organism was not cultured (PCR positive-culture negative).

In Wales, 113 non-O157 cases of 40 different serotypes were confirmed and a further 66 were PCR positive-culture negative. The most common non-O157 serogroups isolated in 2019 were O26 (28/113, 25%), O146 (15/113, 13%), O128ab (10/113, 9%) and O91 (8/113, 7%) followed by O111 (4/113, 4%), O113 (4/113, 4%) and O156 (4/113, 4%).

Research – Attachment of Shiga Toxin-Producing Escherichia coli (STEC) to Pre-Chill and Post-Chill Beef Brisket Tissue


Shiga toxin-producing Escherichia coli (STEC) has caused numerous foodborne illness outbreaks where beef was implicated as the contaminated food source. Understanding how STEC attach to beef surfaces may inform effective intervention applications at the abattoir. This simulated meat processing conditions to measure STEC attachment to adipose and lean beef tissue. Beef brisket samples were warmed to a surface temperature of 30 °C (warm carcass), while the remaining samples were maintained at 4 °C (cold carcass), prior to surface inoculation with an STEC cocktail (O26, O45, O103, O111, O121, O145, and O157:H7). Cocktails were grown in either tryptic soy broth (TSB) or M9 minimal nutrient medium. Loosely and firmly attached cells were measured at 0, 3, 5, and 20 min and 1, 3, 8, 12, 24 and 48 h. TSB-grown STEC cells became more firmly attached throughout storage and a difference in loosely versus firmly attached populations on lean and adipose tissues was observed. M9-grown STEC demonstrated a 0.2 log10 CFU/cm2 difference in attachment to lean versus adipose tissue and variability in populations was recorded throughout sampling. Future research should investigate whether a decrease in intervention efficacy correlates to an increase in firmly attached STEC cells on chilled carcasses and/or subprimals, which has been reported. View Full-Text

Research – Fate of Salmonella and Enterohemorrhagic Escherichia coli on Wheat Grain

Journal of Food Protection

Wheat flour has been connected to outbreaks of foodborne illnesses with increased frequency in recent years, specifically, outbreaks involving Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC). However, there is little information regarding the survival of these pathogens on wheat grain during long-term storage in a low-moisture environment. This study aims to evaluate the long-term survival of these enteric pathogens on wheat grain over the course of a year. Hard red spring wheat was inoculated with strains of four serovars of Salmonella enterica (Enteritidis , Agona, Tennessee, and Montevideo) and six serotypes of EHEC (O157:H7, O26:H11, O121:H19, O45:NM, O111:H8, and O103:H2) in triplicate, sealed in Mylar bags to maintain the water activity, and stored at room temperature (22 ± 1°C). The survival of each pathogen was evaluated by plating onto differential media . Viable counts of strains from all four serovars of Salmonella (Enteritidis , Agona, Tennessee, and Montevideo) were detected on wheat grain stored at room temperature (22 ± 1°C) for the duration of the study (52 weeks). Viable counts of strains from EHEC serotypes O45:NM, O111:H8, and O26:H11 were only detected for 44 weeks and strains from serotypes O157:H7, O121:H19, and O103:H2 were only detected for 40 weeks until they passed below the limit of detection (2.0 log CFU/g). D -values were found to be significantly different between Salmonella and EHEC (adj. p ≤ 0.05) with Salmonella D -values ranging from 22.9 ± 2.2 to 25.2 ± 1.0 weeks and EHEC D -values ranging from 11.4 ± 0.6 to 13.1 ± 1.8 weeks. There were no significant differences amongst the four Salmonella strains or amongst the six EHEC strains (adj. p > 0.05). These observations highlight the wide range of survival capabilities of enteric pathogens in a low-moisture environment and confirm these pathogens are a food safety concern when considering the long shelf life of wheat grain and its products.

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



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.

Research – Investigation of On-Farm Transmission Routes for Contamination of Dairy Cows with Top 7 Escherichia coli O-Serogroups


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.

USA -USDA Will Expand non-O157 STEC Testing to Ground Beef

Food Poisoning Bulletin

According to an announcement in the Federal Register, the USDA will expand non-O157 STEC (Shiga toxin-producing E. coli) testing to ground beef, bench trim, and other raw ground beef components. The non-O157 strains include what’s called the “Big Six” E. coli strains: E. coli O26, O45, O103, O111, O121, and O145.

Research – Shiga toxin-producing Escherichia coli (STEC) and food: attribution, characterization, and monitoring


Strains of pathogenic Escherichia coli that are characterized by their ability to
produce Shiga toxins are referred to as Shiga toxin-producing E. coli (STEC). STEC
are an important cause of foodborne disease and infections have been associated with a wide range of human clinical illnesses ranging from mild non-bloody
diarrhoea to bloody diarrhoea (BD) and haemolytic uraemic syndrome (HUS)
which often includes kidney failure. A high proportion of patients are hospitalized,
some develop end-stage renal disease (ESRD) and some die.
The Codex Committee on Food Hygiene (CCFH) has discussed the issue of STEC
in foods since its 45th Session, and at the 47th Session, in November 2015, it was
agreed that it was an important issue to be addressed (REP 16/FH, 2015)2
. To
commence this work, the CCFH requested the Food and Agriculture Organization
(FAO) and the World Health Organization (WHO) to develop a report compiling
and synthesizing available relevant information, using existing reviews where
possible, on STEC. The CCFH noted that further work on STEC in food, including
the commodities to be focused on, would be determined based on the outputs of
the FAO/WHO consultation.
The information requested by CCFH is divided into three main areas: the global
burden of disease and source attribution; hazard identification and characterization; and monitoring, including the status of the currently available analytical
methods. This report provides an overview of the work undertaken in response to
the request from the CCFH and provides the conclusions and advice of the Expert
Group based on the currently available information.

Research – Survey of Intact and Nonintact Raw Pork Collected at Retail Stores in the Mid-Atlantic Region of the United States for the Seven Regulated Serogroups of Shiga Toxin–Producing Escherichia coli

Journal of Food Protection


A total of 514 raw pork samples (395 ground or nonintact and 119 intact samples) were purchased at retail stores in Pennsylvania, Delaware, and New Jersey between July and December 2017. All raw pork samples were screened for serogroup O26, O45, O103, O111, O121, O145, or O157:H7 cells of Shiga toxin–producing Escherichia coli (STEC-7) using standard microbiological and molecular methods. In short, 21 (5.3%) of the 395 ground or nonintact pork samples and 3 (3.4%) of the 119 intact pork samples tested positive via the BAX system real-time PCR assay for the stx and eae virulence genes and for the somatic O antigens for at least one of the STEC-7 serogroups. However, none of these 24 presumptive-positive pork samples subsequently yielded a viable isolate of STEC displaying a STEC-7 serogroup-specific surface antigen in combination with the stx and eae genes. These data suggest that cells of STEC serogroups O26, O45, O103, O111, O121, O145, or O157:H7 are not common in retail raw pork samples in the mid-Atlantic region of the United States.

  • None of the 514 retail raw pork samples were positive for STEC-7.

  • Four of 514 raw pork samples harbored E. coli of unknown serogroup containing stx and eae.

  • STEC-7 are uncommon in retail raw pork samples in the U.S. mid-Atlantic region.


Research – Antibiofilm Efficacy of Peptide 1018 against Listeria monocytogenes and Shiga Toxigenic Escherichia coli on Equipment Surfaces

Journal of Food Protection


Listeria monocytogenes and Shiga toxigenic Escherichia coli (STEC) are important foodborne bacterial pathogens that can form biofilms on equipment surfaces at food processing facilities. Pathogens in biofilms are resistant to conventional antimicrobials and require higher antimicrobial concentrations to be inactivated. In this study, the efficacy of a synthetic innate defense regulator peptide 1018 (peptide 1018) for inactivating L. monocytogenes and STEC (O26, O111, O145, O157) biofilms on stainless steel and polycarbonate surfaces was investigated. Stainless steel and polycarbonate coupons (12 mm in diameter) were used in a Centers for Disease Control and Prevention biofilm reactor containing 400 mL of 10% tryptic soy broth (TSB) that had been inoculated with an individual strain of L. monocytogenes or STEC to obtain 6 log CFU/mL populations. The reactor was set with a constant flow rate at 50 mL/h of 10% TSB for 48 h. After 48 h, coupons were treated with peptide 1018 at 0, 10, 20, or 50 μg/mL in phosphate buffer saline (PBS) for 24 h. Surviving bacterial populations were determined by scraping off the coupons and spiral plating on selective media. Significantly higher levels of pathogens in biofilms formed by certain bacterial strains, including L. monocytogenes F6854, E. coli O157:H7 RM4407 and NADC5713, and non-O157 E. coli NADC3629, were recovered on polycarbonate surfaces than on stainless steel. Antibiofilm efficacy of peptide 1018 against pathogens was concentration-dependent and varied with the type of pathogen and material surfaces. Peptide 1018 at 50 μg/mL significantly inactivated all tested bacterial biofilms on both surfaces compared with the PBS control (P < 0.05). L. monocytogenes was the bacterium most sensitive to peptide 1018; on stainless steel surfaces treated with 50 μg/mL peptide 1018, there was a 3.7- to 4.6-log CFU/cm2 reduction in Listeria populations compared with a 1.0- to 3.5-log CFU/cm2 reduction of STEC. Results suggest that peptide 1018 may be used to inactivate L. monocytogenes and STEC biofilms on equipment surfaces.

  • Bacteria attach at higher levels on polycarbonate surfaces than on stainless steel.

  • L. monocytogenes is more sensitive than STEC to peptide 1018.

  • Peptide 1018 can be used to inactivate biofilms on equipment surfaces.

France – E. Coli Bacteria: Chaource Lincet and Gaugry Raw Milk Cheeses Recalled – STEC E.coli O111:H8

Teller Report

A few hundred Chaource raw milk cheese brands Lincet and Gaugry, sold throughout France, are subject to a recall procedure after the demonstration of the presence of Escherichia coli. A check has highlighted in these products, manufactured by the Lincet cheese factory in Vaudes in the Aube, the presence of Escherichia coli O111: H8, indicates the cheese Friday in a statement.