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Aims Plant-based alternatives to meat and dairy products have become increasingly popular in the UK. Despite a public perception that they have a relatively low microbiological risk, outbreaks of illness have been linked with these foods. This study aimed to assess the microbiological safety and quality of vegan alternatives to dairy and meat products available in England. Methods and results Samples were collected between September 2022 and March 2023 from retail, production, and catering premises, and tested for a range of bacterial pathogens and hygiene indicators using standard procedures. A total of 937 samples were tested, of which 92% were of a satisfactory microbiological quality, 3% were borderline, and 5% were unsatisfactory. Those interpreted as unsatisfactory were due to elevated counts of Enterobacteriaceae and Escherichia coli (indicators of poor hygiene) rather than pathogenic microorganisms. Listeria monocytogenes was present in five samples of tofu, all from the same producer (all at counts of <100 CFU g–1), while other Listeria species were detected at counts of <20 CFU g–1 in two burgers and two 'vegan chicken' products. The majority of samples did not have pH and water activity values that would significantly contribute to preventing microbial growth: 62.4% had pH > 5.0 and 82.4% had A w > 0.94. Conclusions The majority of vegan products examined were of a satisfactory quality, but results demonstrate that microbiological control must be maintained using appropriate processing and storage temperatures, and application of a safe length of shelf life. [ABSTRACT FROM AUTHOR]

Aim To investigate the possible contamination of raw flour and raw flour-based products, such as pancake/batter mixes, with Salmonella , generic Escherichia coli , and Shiga-toxin-producing E. coli (STEC). Samples included flours available for sale in the UK over a period of four months (January to April 2020). The Bread and Flour regulations, 1998 state the permitted ingredients in flour and bread but it does not specify the regular monitoring of the microbiological quality of flour and flour-based products. Methods and results Samples of raw flour were collected by local authority sampling officers in accordance with current guidance on microbiological food sampling then transported to the laboratory for examination. Microbiological testing was performed to detect Salmonella spp. generic E. coli , and STEC characterized for the presence of STEC virulence genes: stx 1, stx 2, and subtypes, eae, ipah, aggR, lt, sth , and stp , using molecular methods Polymerase Chain Reaction (PCR). Of the 882 flours sampled, the incidence of Salmonella was 0.1% (a single positive sample that contained multiple ingredients such as flour, dried egg, and dried milk, milled in the UK), and 68 samples (7.7%) contained generic E. coli at a level of >20 CFU/g. Molecular characterization of flour samples revealed the presence of the Shiga-toxin (stx) gene in 10 samples (5 imported and 5 from the UK) (1.1%), from which STEC was isolated from 7 samples (0.8%). Salmonella and STEC isolates were sequenced to provide further characterization of genotypes and to compare to sequences of human clinical isolates held in the UKHSA archive. Using our interpretive criteria based on genetic similarity, none of the STEC flour isolates correlated with previously observed human cases, while the singular Salmonella serotype Newport isolate from the mixed ingredient product was similar to a human case in 2019, from the UK, of S. Newport. Although there have been no reported human cases of STEC matching the isolates from these flour samples, some of the same serotypes and stx subtypes detected are known to have caused illness in other contexts. Conclusion Results indicate that while the incidence was low, there is a potential for the presence of Salmonella and STEC in flour, and a genetic link was demonstrated between a Salmonella isolate from a flour-based product and a human case of salmonellosis. [ABSTRACT FROM AUTHOR]

Enteroinvasive Escherichia coli (EIEC) bacteria are human enteric pathogens that have been identified worldwide. EIEC has been found to be endemic to developing countries, particularly where sanitation is poor, and [...]

Aim Frozen, breaded chicken products have been implicated in Salmonella outbreaks, and may be incorrectly perceived as ready-to-eat, leading to mishandling or undercooking by consumers. This study aimed to assess the prevalence of Salmonella and antimicrobial resistant (AMR) Escherichia coli in these products. Methods and results Samples of frozen, raw, or partly cooked, coated chicken products were collected between April and July 2021 from retailers in the UK and tested for Salmonella spp. generic E. coli , extended spectrum beta-lactamase-producing, colistin-resistant, and carbapenem-resistant E. coli. One isolate of each bacterial type from each sample was selected for minimum inhibitory concentration determination for a range of antimicrobials. Salmonella was detected in 5 of 310 (1.6%) samples, identified as Salmonella Infantis in three samples and Salm. Java in two. One Salm. Infantis isolate was multidrug resistant, while the other Salmonella isolates were each resistant to at least one class of antimicrobials. Generic E. coli were detected in 113 samples (36.4%), with multidrug resistance being demonstrated in 20.0% of these. Escherichia coli with the ESBL phenotype were detected in 15 (4.8%) of samples and the AmpC phenotype in 2 (0.6%). A colistin-resistant E. coli was isolated from one sample; this possessed the mcr-1 gene. No carbapenem-resistant E. coli were detected. The five Salmonella -positive samples from this study, together with 20 Salmonella -positive products from an earlier study in 2020/2021, were cooked according to the manufacturers' instructions. Following cooking, Salmonella was not detected in any samples. Conclusions This survey demonstrates continued contamination of frozen, coated chicken products with Salmonella , and provides data on the prevalence of AMR in these products. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes is a foodborne pathogen of significant concern for the food industry due to its remarkable ability to persist through safety control efforts, posing a subsequent health threat to consumers. Understanding the microbial communities coexisting with L. monocytogenes in food processing environments provides insights into its persistence mechanisms. We investigated the microbial communities on non-food contact surfaces in a facility producing ready-to-eat foods, known to harbour a ST121 L. monocytogenes strain over multiple years. A 10-week sampling period was coordinated with the company and public health authorities. Metagenomic analysis revealed a stable microbial composition dominated by Pseudomonas fluorescens. While highly related populations were present in high-care production zones, distinctive taxa characteristic of specific areas were observed (e.g., Sphingomonas aerolata). Although Listeria spp. were not detected in metagenomes, they were detected in cultured samples, suggesting low relative abundance in factory settings. The findings suggest that a stable resident microbiota, with distinct adaptations to different areas within the factory, was selected for by their collective ability to survive control efforts in this environment. Listeria spp. was a member of this microbial community, albeit at low abundance, and may likewise benefit from the mutualism of the overall microbial community. • Microbiota on non-food contact surfaces remains stable in factory environment. • Distinctive microbiota observed in different factory areas. • Microbiota adapted to environmental conditions within factory. • Listeria monocytogenes and Listeria spp. are present on surfaces at low abundance. [ABSTRACT FROM AUTHOR]

In October 2019, public health surveillance systems in Scotland identified an increase in the number of reported infections of Shiga toxin-producing Escherichia coli (STEC) O26:H11 involving bloody diarrhoea. Ultimately, across the United Kingdom (UK) 32 cases of STEC O26:H11 stx1a were identified, with the median age of 27 years and 64% were male; six cases were hospitalised. Among food exposures there was an association with consuming pre-packed sandwiches purchased at outlets belonging to a national food chain franchise (food outlet A) [odds ratio (OR) = 183.89, P < 0.001]. The common ingredient identified as a component of the majority of the sandwiches sold at food outlet A was a mixed salad of Apollo and Iceberg lettuce and spinach leaves. Microbiological testing of food and environmental samples were negative for STEC O26:H11, although STEC O36:H19 was isolated from a mixed salad sample taken from premises owned by food outlet A. Contamination of fresh produce is often due to a transient event and detection of the aetiological agent in food that has a short-shelf life is challenging. Robust, statistically significant epidemiological analysis should be sufficient evidence to direct timely and targeted on-farm investigations. A shift in focus from testing the microbiological quality of the produce to investigating the processes and practices through the supply chain and sampling the farm environment is recommended. [ABSTRACT FROM AUTHOR]

In August 2017, a cluster of four persons infected with genetically related strains of Shiga toxin-producing Escherichia coli (STEC) O157:H7 was identified. These strains possessed the Shiga toxin (stx) subtype stx2a, a toxin type known to be associated with severe clinical outcome. One person died after developing haemolytic uraemic syndrome. Interviews with cases revealed that three of the cases had been exposed to dogs fed on a raw meat-based diet (RMBD), specifically tripe. In two cases, the tripe had been purchased from the same supplier. Sampling and microbiological screening of raw pet food was undertaken and indicated the presence of STEC in the products. STEC was isolated from one sample of raw tripe but was different from the strain causing illness in humans. Nevertheless, the detection of STEC in the tripe provided evidence that raw pet food was a potential source of human STEC infection during this outbreak. This adds to the evidence of raw pet food as a risk factor for zoonotic transmission of gastrointestinal pathogens, which is widely accepted for Salmonella, Listeria and Campylobacter spp. Feeding RMBD to companion animals has recently increased in popularity due to the belief that they provide health benefits to animals. Although still rare, an increase in STEC cases reporting exposure to RMBDs was detected in 2017. There has also been an increased frequency of raw pet food incidents in 2017, suggesting an increasing trend in potential risk to humans from raw pet food. Recommendations to reduce the risk of infection included improved awareness of risk and promotion of good hygiene practices among the public when handling raw pet food. [ABSTRACT FROM AUTHOR]

Between February and April 2018, Salmonella typhimurium within a unique 5-single nucleotide polymorphism (SNP) address was isolated from 28 cases with links to a small rural area of Northeast England, with five cases prospectively identified by whole genome sequencing (WGS). Infections had a severe clinical picture with ten cases hospitalized (36%), two cases with invasive disease, and two deaths reported. Interviews determined that 24 cases (86%) had been exposed to a local independent butcher's shop (Butcher A).A case-control study using controls recruited by systematic digit dialling established that cases were 68 times more likely to have consumed cooked meat from Butcher A (Adjusted OR 68.1; 95% CI: 1.9-2387.6; P  = 0.02). Salmonella typhimurium genetically highly related to 28 of the outbreak cases was also isolated from a sample of cooked meat on sale in the premises.Epidemiological and microbiological investigations suggest this outbreak was likely associated with the consumption of ready-to-eat foods supplied by the implicated butcher. A relatively large number of cases were involved despite the rurality of the food business, with cases resident across the Northeast and Yorkshire identified using WGS, demonstrating the benefit of timely sequencing information to community outbreak investigations.

Results from monitoring of the microbiological quality of 2,721 samples of ready-to-eat cooked chicken collected between 2013 to 2017 in England were reviewed: 70% of samples were from retail, catering or manufacture and 30% were imported and collected at English ports. Samples were tested for a range of bacterial pathogens and indicator organisms. Six samples (<1%) had unsatisfactory levels of pathogens which were potentially injurious to health. Neither Salmonella nor Campylobacter were recovered from any sample. Two samples from catering settings contained either an unsatisfactory level of Bacillus cereus (5 x 10 6 CFU/g) or an unsatisfactory level of coagulase positive staphylococci (1.6 x 10 4 CFU/g). Listeria monocytogenes was recovered from 36 samples (one at manufacture, 26 at catering and nine at retail) and in four instances, unsatisfactory levels (≥10 2 CFU/g) were detected (three samples collected at catering and one at retail). For L. monocytogenes there were no significant differences between the rates of contamination with between the samples collected from ports, manufacture, retail supermarkets and other retailers (p = 0.288). There were no differences between the rates of contamination for other potential pathogens detected between samples from different settings. The prevalence of hygiene indicators ( Escherichia coli , Enterobacteriaceae and Aerobic Colony Counts) at import was significantly lower than in samples collected from manufacturers, retail or catering (p < 0.01). Samples collected from catering gave poorer results than all other settings. Regardless of the stage in the food chain, samples from Thailand and from other non-EU countries were of significantly better microbiological quality with respect to indicator organisms than those from the UK or from other EU countries (p = <0.001)., (Copyright © 2020 International Association for Food Protection. Published by Elsevier Inc. All rights reserved)