Development and evaluation of test methods for the detection and enumeration of opportunistic waterborne pathogens from the hospital environment.

BACKGROUND: Many Gram-negative bacteria other than Pseudomonas aeruginosa have been implicated in waterborne outbreaks, but standardized laboratory detection methods for these organisms have not been established. AIM: This study aimed to establish laboratory testing methodologies for six waterborne pathogens: Acinetobacter spp., Burkholderia spp., Cupriavidus spp., Delftia acidovorans, Elizabethkingia spp. and Stenotrophomonas maltophilia. METHODS: Water samples were spiked by UK Health Security Agency laboratories and sent to the Glasgow Royal Infirmary laboratory for analysis. Water samples were spiked with either a pure culture of target organism or the target organism in water containing normal background flora, to ensure that the methodology could identify organisms from a mixed culture. Volumes of 100 mL were filtered under negative pressure on to culture media and incubated at 30 °C and 37 °C. The incubation time was 7 days, with plates read on days 2, 5 and 7. Further identification of colonies was undertaken using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). FINDINGS: Optimal recovery of organisms was obtained by culturing water samples on tryptic soy agar, chocolate bacitracin agar and pseudomonas selective agar. The optimal temperature for isolation was 30 °C. The optimal incubation time was 5 days, and MALDI-TOF MS identified all test species reliably. CONCLUSION: The methodology described was able to detect the six tested waterborne pathogens reliably, and can be utilized by laboratories involved in testing water samples during outbreak investigations.

Mitochondrial complex I activity in microglia sustains neuroinflammation.

Sustained smouldering, or low-grade activation, of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis1. Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells2. However, how these metabolic features act to perpetuate inflammation of the central nervous system is unclear. Here, using a multiomics approach, we identify a molecular signature that sustains the activation of microglia through mitochondrial complex I activity driving reverse electron transport and the production of reactive oxygen species. Mechanistically, blocking complex I in pro-inflammatory microglia protects the central nervous system against neurotoxic damage and improves functional outcomes in an animal disease model in vivo. Complex I activity in microglia is a potential therapeutic target to foster neuroprotection in chronic inflammatory disorders of the central nervous system3.

Mitochondrial reverse electron transport in myeloid cells perpetuates neuroinflammation.

Sustained smouldering, or low grade, activation of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis (MS) 1 . Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells 2 . However, how these metabolic features act to perpetuate neuroinflammation is currently unknown. Using a multiomics approach, we identified a new molecular signature that perpetuates the activation of myeloid cells through mitochondrial complex II (CII) and I (CI) activity driving reverse electron transport (RET) and the production of reactive oxygen species (ROS). Blocking RET in pro-inflammatory myeloid cells protected the central nervous system (CNS) against neurotoxic damage and improved functional outcomes in animal disease models in vivo . Our data show that RET in myeloid cells is a potential new therapeutic target to foster neuroprotection in smouldering inflammatory CNS disorders 3 .

Effects of exercise intensity on gut microbiome composition and function in people with type 2 diabetes.

Exercise is positively associated with higher microbial diversity, but there is limited information on exercise intensity's effect on gut microbiome composition and function in clinical populations. This study examines whether different intensities of exercise exert differential effects on gut microbiome composition and function in low active people with type 2 diabetes. This is a sub-study of the Exercise for Type 2 Diabetes Study, a single centre, prospective, randomised controlled trial. Participants (n = 12) completed 8-weeks of combined aerobic and resistance moderate intensity continuous training (C-MICT) or combined aerobic and resistance high-intensity interval training (C-HIIT). Faecal samples were collected before and after intervention to measure gut microbiome composition and metabolic pathways (metagenome shotgun sequencing) and short-chain fatty acids. Post-exercise α-diversity was different between groups as was the relative abundance of specific taxa was (p < .05). Post-exercise relative abundance of Bifidobacterium, A. municiphila, and butyrate-producers Lachnospira eligens, Enterococcus spp., and Clostridium Cluster IV were higher at lower exercise intensity. Other butyrate-producers (from Eryspelothrichales and Oscillospirales), and methane producer Methanobrevibacter smithii were higher at higher exercise intensity. Pyruvate metabolism (ko00620),COG "Cell wall membrane envelope biogenesis" and "Unknown function" pathways were significantly different between groups and higher in C-MICT post-exercise. Differential abundance analysis on KO showed higher expression of Two-component system in C-HIIT. Transcription factors and "unknown metabolism" related pathways decreased in both groups. There were no significant between group changes in faecal short chain fatty acids. Exercise intensity had a distinct effect on gut microbiome abundance and metabolic function, without impacting short-chain fatty acid output.HighlightsEvidence of exercise effect on gut microbiome outcomes is limited to healthy and athletic populationsIn low active people with type 2 diabetes, different exercise intensities increased specific health promoting and butyrate producers species, and showed differentially abundant gut microbiome metabolic pathways.Further investigation is warranted, and if this supports the present findings, then specific exercise intensities may be promoted to target specific species and optimise gut health.

Final results from the ribavirin pregnancy registry, 2004-2020.

INTRODUCTION: Significant teratogenic effects have been demonstrated for ribavirin in animal studies. Ribavirin is prescribed for chronic hepatitis C and is contraindicated in pregnant women and their male sexual partners. Both are advised to avoid pregnancy for 6 months after exposure. The registry monitored pregnancy exposures to oral formulations of ribavirin for hepatitis C for signals of possible human teratogenicity from 2004 to 2020. METHODS: Pregnant women were voluntarily enrolled following direct exposure (ribavirin use during pregnancy or the 6 months prior) or indirect exposure (through sexual contact during pregnancy or 6 months prior, with a man who has taken ribavirin within 6 months). Women were followed until the end of pregnancy. Infants were followed until 1 year of age. Birth defect rates were compared with the published rate of 2.67 per 100 live births from the Metropolitan Atlanta Congenital Defects Program (MACDP). RESULTS: The registry enrolled 280 pregnancies resulting in 186 live births: eight birth defect cases among 88 directly exposed [9.09% (8/88, 95% CI: 4.01, 17.13)], and six birth defect cases among 98 indirectly exposed [6.12% (6/98, 95% CI: 2.28, 12.85)]. The 95% CI around the birth defect rate among directly exposed pregnancies exceeds the MACDP rate; however, no patterns suggestive of a teratogenic mechanism or safety signal were detected. CONCLUSION: Based on the patterns of birth defects reported, the final results from this registry do not suggest a clear signal of human teratogenicity for ribavirin. The registry did not meet sample size requirements; therefore, caution should be exercised when interpreting the results.

Microbiological Quality of Ready-to-Eat Salad Products Collected from Retail and Catering Settings in England during 2020 to 2021.

ABSTRACT: Salad and other fresh produce were collected in England from retail and catering businesses during 2020 to 2021 and were tested for Salmonella, Shiga toxin-producing Escherichia coli (STEC), Listeria, Bacillus cereus, and E. coli. Of the 604 samples collected, 57% were from retail settings and 43% were from catering settings; 61% were either salad leaves or salad leaves mixed with other products. Equal numbers of samples were prepacked or loose, and 50% were refrigerated at the time of sampling. Combining results for all microbiological parameters, 84% were interpreted as satisfactory, 12% were interpreted as borderline, and 4% were interpreted as unsatisfactory. One sample (prepacked leaves, cucumber, and tomato from a caterer) was categorized as unacceptable and potentially injurious because of detection of STEC O76; no STEC from human infections in the United Kingdom matched this isolate. No Salmonella enterica was detected, but Listeria monocytogenes was recovered from 11 samples: 1 at 20 CFU/g and the remainder at <20 CFU/g. B. cereus was detected at borderline levels (103 to ≤105 CFU/g) in 9% of samples and at an unsatisfactory level (>105 CFU/g) in one sample. E. coli was detected in 3% of samples at borderline levels (20 to ≤102 CFU/g) and in 4% at unsatisfactory levels (>102 CFU/g). There was a significant association between detection of L. monocytogenes and borderline or unsatisfactory levels of E. coli. There were no specific risk profiles associated with products with the higher levels of B. cereus, STEC, or Listeria, but elevated levels of E. coli were predominantly confined to loose products from the United Kingdom collected from caterers in summer or autumn 2021 and may have resulted from relaxation of COVID-19 restrictions. Among the L. monocytogenes isolates, only one matched those from human cases and was recovered from a prepacked mixed salad from a catering business in 2021. This isolate was the same strain as that responsible for a multicountry outbreak (2015 to 2018) associated with Hungarian-produced frozen sweet corn; no link to the outbreak food chain was established.

Assessment of the Microbiological Quality and Safety of Unpasteurized Milk Cheese for Sale in England between 2019 and 2020.

ABSTRACT: Cheese made with unpasteurized milk has been associated with outbreaks of illness. However, there are limited data on the prevalence of Shiga toxin-producing Escherichia coli (STEC) in these products and a lack of clarity over the significance of E. coli as a general indicator of hygiene in raw milk cheeses. The aim of this study was to provide further data to address both of these issues, as well as assessing the overall microbiological quality of raw milk cheeses available to consumers in England. A total of 629 samples of cheese were collected from retailers, catering premises, and manufacturers throughout England. The majority (80%) were made using cow's milk, with 14% made from sheep's milk and 5% from goat's milk. Samples were from 18 different countries of origin, with the majority originating from either the United Kingdom (40%) or France (35%). When interpreted against European Union microbiological criteria and United Kingdom guidance, 82% were considered to be of satisfactory microbiological quality, 5% were borderline, and 12% were unsatisfactory. Four samples (0.6%) were potentially injurious to health due to the isolation of STEC from one, >104 CFU/g of coagulase-positive staphylococci in two, and >100 CFU/g of Listeria monocytogenes in the fourth sample. Indicator E. coli and Listeria species were detected more frequently in soft compared with hard cheese. Higher levels of indicator E. coli were significantly associated with a greater likelihood of detecting Shiga toxin genes (stx1 and/or stx2).

Design of a 16-channel fiber-optic coupled radiation detection array for radiation asymmetry studies in a 750-kJ dense plasma focus.

A 16-channel fiber optically coupled radiation detection array has been developed for studies of radiation asymmetries and emission histories from the Verus Research 750-kJ Dense Plasma Focus. Each detector in the array consists of a light-tight housing with a plastic scintillator coupled to a fiber optic that is fed into one channel of a multi-anode photomultiplier tube (PMT). The PMT and associated electronics are located in a remote electrically shielded control room. The detector head is configurable for using a Be-9 foil to take advantage of the 9Be(n,α)6He reaction as a fast neutron activation detector or with a bare scintillator alone to record the radiation emission history. Fiber optically coupling the detector head not only provides electrical isolation in the pulsed power environment but also allows the spatial footprint of the detector array to be reduced with concomitant flexibility in positioning each individual detector head. The array allows for spatially resolved neutron yield and radiation waveform measurements for fast z-pinches. The activation detector heads were calibrated for the total neutron yield against silver and indium activation counters for the total neutron yield. Fiber scintillation was found to contribute to the time-resolved detector head signals and was accounted for.

Polyketide ß-branching: diversity, mechanism and selectivity.

Covering: 2008 to August 2020 Polyketides are a family of natural products constructed from simple building blocks to generate a diverse range of often complex chemical structures with biological activities of both pharmaceutical and agrochemical importance. Their biosynthesis is controlled by polyketide synthases (PKSs) which catalyse the condensation of thioesters to assemble a functionalised linear carbon chain. Alkyl-branches may be installed at the nucleophilic α- or electrophilic ß-carbon of the growing chain. Polyketide ß-branching is a fascinating biosynthetic modification that allows for the conversion of a ß-ketone into a ß-alkyl group or functionalised side-chain. The overall transformation is catalysed by a multi-protein 3-hydroxy-3-methylglutaryl synthase (HMGS) cassette and is reminiscent of the mevalonate pathway in terpene biosynthesis. The first step most commonly involves the aldol addition of acetate to the electrophilic carbon of the ß-ketothioester catalysed by a 3-hydroxy-3-methylglutaryl synthase (HMGS). Subsequent dehydration and decarboxylation selectively generates either α,ß- or ß,γ-unsaturated ß-alkyl branches which may be further modified. This review covers 2008 to August 2020 and summarises the diversity of ß-branch incorporation and the mechanistic details of each catalytic step. This is extended to discussion of polyketides containing multiple ß-branches and the selectivity exerted by the PKS to ensure ß-branching fidelity. Finally, the application of HMGS in data mining, additional ß-branching mechanisms and current knowledge of the role of ß-branches in this important class of biologically active natural products is discussed.

Listeria monocytogenes in Cooked Chicken: Detection of an Outbreak in the United Kingdom (2016 to 2017) and Analysis of L. monocytogenes from Unrelated Monitoring of Foods (2013 to 2017).

ABSTRACT: In England and Wales, Public Health England applies whole genome sequencing to cultures of Listeria monocytogenes recovered from human cases of listeriosis, foods, and food production environments. Following the routine inspection of a small retailer in February and March 2016, two unopened packs of cooked chicken produced by the same manufacturer were found to be contaminated with L. monocytogenes at levels of 340 and 20 CFU/g. A public recall of this product was issued in March 2016. Early in 2017, a less than five single-nucleotide polymorphism single-linkage cluster was detected between the L. monocytogenes isolates from the two cooked chicken products and cultures from five cases of human listeriosis in England and Scotland with onsets of illness between March 2016 and February 2017. Epidemiological data provided further supportive evidence that this cluster was an outbreak linked to a manufacturer of cooked chicken whose products were supplied to the small retailer that initiated the outbreak investigation. Unrelated to this outbreak, 34 L. monocytogenes isolates recovered from routine food monitoring of 2,007 samples of cooked chicken during 2013 to 2017 were analyzed by whole genome sequencing. Previously undetected fewer than five single-nucleotide polymorphism single-linkage clusters were identified between cultures from cooked chicken and with those from two clusters and two sporadic cases of human listeriosis that were consistent with foodborne transmission. This analysis identified linkage of L. monocytogenes clusters within specific food chains more readily than traditional manual tracing. Linking of data associated with L. monocytogenes cultures from cases of listeriosis with those from unrelated food testing is a unique source of information for communicable disease risk assessment, epidemiological studies, and disease prevention and control. This report provides further evidence that should act as a reminder of the association between cooked chicken consumption and human listeriosis.

Microbiological quality of raw drinking milk and unpasteurised dairy products: results from England 2013-2019.

The aim of this study was to review microbiology results from testing >2500 raw drinking milk and dairy products made with unpasteurised milk examined in England between 2013 and 2019. Samples were collected as part of incidents of contamination, investigation of infections or as part of routine monitoring and were tested using standard methods for a range of both pathogens and hygiene indicators. Results from testing samples of raw cow's milk or cheese made from unpasteurised milk for routine monitoring purposes were overall of better microbiological quality than those collected during incident or investigations of infections. Results from routine monitoring were satisfactory for 62% of milks, 82% of cream, 100% of ice-cream, 51% of butter, 63% of kefir and 79% of cheeses, with 5% of all samples being considered potentially hazardous. Analysis of data from cheese demonstrated a significant association between increasing levels of indicator Escherichia coli with elevated levels of coagulase positive staphylococci and decreased probability of isolation of Shiga toxin-producing E. coli. These data highlight the public health risk associated with these products and provide further justification for controls applied to raw drinking milk and dairy products made with unpasteurised milk.

Public health risks associated with Salmonella contamination of imported edible betel leaves: Analysis of results from England, 2011-2017.

Fresh betel leaves (Piper betle L.), imported into the UK are a traditional ready-to-eat food consumed by Asian populations. We report here the consolidation of routinely collected data to model the public health risks from consumption of this food. Amongst 2110 samples collected at Border Inspection, wholesale, catering or retail, Salmonella was detected in 488 (23%) of samples tested between 2011 and 2017 and was the most commonly Salmonella-contaminated ready-to-eat food examined by Public Health England during this period. Using data from multiple samples (usually 5) tested per consignment sampled at Border Inspection, contamination levels were calculated by most probable number: seasonal, temporal and country specific differences were detected. Quantitative contamination data was used to estimate the levels present at retail, and a ß-Poisson dose response model the probability of illness was calculated. Using data for products imported from India, the probability of acquiring infection following a single exposure (comprising of a single leaf) was estimated to be between 0.00003 (January-March) and 0.0001 (July-September). Using British Asian population data for individuals over 30 years of age in England in 2011, two estimates of consumption were modelled as 2.1 and 12.8 million servings per annum. Results from the model estimated 160 cases (range 102 to 242) and 960 cases (range 612 to 1456) per year in England for the two consumption estimates and equated to 34 (range 22 to 51) and 204 (range 130 to 310) salmonellosis cases per year reported to national surveillance. Salmonella from 475 of the contaminated samples were further characterised which showed a heterogeneous population structure with 46 S. enterica subsp. Enterica serovars, together with S. enterica subs diarizonae and salamae identified. Isolates from individual consignments were diverse and close genetic relationships between independent isolates were very rare except from within an individual consignment. There were no outbreaks detected as associated with betel leaf consumption. However analysis by whole genome sequencing of the 2014-17 data identified two cases where the clinical isolate had <5 single nucleotide polymorphism differences to isolates from betel leaves which is indicative of a likely epidemiological link and common source of contamination. Due to the diversity of the Salmonella contaminating this product, associations between salmonellosis cases and betel leaf consumption will appear sporadic and unlikely to be detected by current surveillance strategies based on outbreak detection.

Imported edible leaves collected at retail sale in England during 2017 with an emphasis on betel and curry leaves: microbiological quality with respect to Salmonella, Shiga-toxin-producing E. coli (STEC) and levels of Escherichia coli.

AIMS: To investigate the microbiological quality of imported fresh leaves on retail sale during 2017 with respect to Salmonella, Shiga-toxin-producing Escherichia coli (STEC) and levels of E. coli. METHODS AND RESULTS: Two hundred and seventy-nine samples of imported edible leaves (69 banana, 77 betel, 118 curry and 15 other types) were tested. Salmonella spp. were confirmed by whole-genome sequencing and isolated from 44 samples, 26% from curry leaves, 14% from betel and 2·4% from all other leaf types: 80% of all samples contained ≥102 , 44% ≥103 and 22% ≥104 CFU of E. coli CFU per g. All samples where Salmonella were detected also yielded ≥20 CFU of E. coli/g. 54 samples were tested for STEC which was detected in six samples and isolated from three: one was identified as STEC O157:H7. CONCLUSIONS: This report further highlights an ongoing problem of Salmonella contamination of imported fresh edible leaves. SIGNIFICANCE AND IMPACT OF THE STUDY: Among all food tested by Public Health England (approximately 11 000 per annum), curry leaves were the herb most commonly contaminated with Salmonella, and betel leaves were the most commonly contaminated ready-to-eat food. The high proportion with unsatisfactory E. coli levels and the detection of STEC suggests risks of contamination by multiple enteric pathogens.

Corticosteroids Reduce Risk of Death Within 28 Days for Patients With Severe Alcoholic Hepatitis, Compared With Pentoxifylline or Placebo-a Meta-analysis of Individual Data From Controlled Trials.

BACKGROUND & AIMS: We performed a meta-analysis of individual patient data from 11 randomized controlled trials comparing corticosteroids, pentoxifylline, or their combination in patients with severe alcoholic hepatitis. We compared the effects of the treatments on survival for 28 days or 6 months, and response to treatment based on the Lille model. METHODS: We searched PubMed for randomized controlled trials of pharmacologic therapy for severe alcoholic hepatitis. Our final analysis comprised 11 studies, of 2111 patients. We performed 4 meta-analyses of the effects of corticosteroids vs placebo or control, corticosteroids vs pentoxifylline, corticosteroids and pentoxifylline vs corticosteroids and placebo or control, and pentoxifylline vs placebo. In each meta-analysis, the effect of treatment on the primary outcome (overall survival at 28 days, defined as the period from the first day of assigned treatment to 28 days) was estimated using a Cox proportional hazards regression model, including trials as random effect. RESULTS: Corticosteroid treatment significantly decreased risk of death within 28 days compared with controls (hazard ratio [HR] 0.64; 95% confidence interval [CI] 0.48-0.86) or to pentoxifylline (HR 0.64; 95% CI 0.43-0.95). In multiple-imputation and complete case analyses, the effect of corticosteroids compared with controls remained significant. When we compared corticosteroids vs pentoxifylline, the corticosteroid effect remained significant in the complete case analysis (HR 0.66; P = .04) but not in multiple-imputation analysis (HR 0.71; P = .08). There was no difference in 28-day mortality when patients were given a combination of corticosteroids and pentoxifylline vs corticosteroids alone or between patients given pentoxifylline vs control. In our analysis of secondary outcomes, we found no significant differences in 6-month mortality when any treatments or controls were compared. Corticosteroids were significantly associated with increased response to therapy compared with controls (relative risk 1.24; 95% CI 1.10-1.41) or pentoxifylline (relative risk 1.43; 95% CI 1.20-1.68). We found no difference in response to therapy between patients given a combination of corticosteroids and pentoxifylline vs corticosteroids alone or pentoxifylline vs controls. CONCLUSIONS: In a meta-analysis of 4 controlled trials, we found corticosteroid use to reduce risk of death within 28 days of treatment, but not in the following 6 months. This loss of efficacy over time indicates a need for new therapeutic strategies to improve medium-term outcomes.

A realist evaluation of a physical activity participation intervention for children and youth with disabilities: what works, for whom, in what circumstances, and how?

BACKGROUND: The need to identify strategies that facilitate involvement in physical activity for children and youth with disabilities is recognised as an urgent priority. This study aimed to describe the association between context, mechanisms and outcome(s) of a participation-focused physical activity intervention to understand what works, in what conditions, and how. METHODS: This study was designed as a realist evaluation. Participant recruitment occurred through purposive and theoretical sampling of children and parents participating in the Local Environment Model intervention at Beitostolen Healthsports Centre in Norway. Ethnographic methods comprising participant observation, interviews, and focus groups were employed over 15 weeks in the field. Data analysis was completed using the context-mechanism-outcome framework of realist evaluation. Context-mechanism-outcome connections were generated empirically from the data to create a model to indicate how the program activated mechanisms within the program context, to enable participation in physical activity. RESULTS: Thirty one children with a range of disabilities (mean age 12y 6 m (SD 2y 2 m); 18 males) and their parents (n = 44; 26 mothers and 18 fathers) participated in the study. Following data synthesis, a refined program theory comprising four context themes, five mechanisms, and six outcomes, were identified. The mechanisms (choice, fun, friends, specialised health professionals, and time) were activated in a context that was safe, social, learning-based and family-centred, to elicit outcomes across all levels of the International Classification of Functioning, Disability and Health. CONCLUSIONS: The interaction of mechanisms and context as a whole facilitated meaningful outcomes for children and youth with disabilities, and their parents. Whilst optimising participation in physical activity is a primary outcome of the Local Environment Model, the refined program theory suggests the participation-focused approach may act as a catalyst to promote a range of outcomes. Findings from this study may inform future interventions attempting to enable participation in physical activity for children and youth with disabilities.

Stress Responses of Aquatic Plants to Silver Nanoparticles.

Silver nanoparticles (AgNPs) are increasingly used in consumer products, biotechnology, and medicine, and are released into aquatic ecosystems through wastewater discharge. This study investigated the phytotoxicity of AgNPs to aquatic plants, Egeria densa and Juncus effusus by measuring physiologic and enzymatic responses to AgNP exposure under three release scenarios: two chronic (8.7 mg, weekly) exposures to either zerovalent AgNPs or sulfidized silver nanoparticles; and a pulsed (450 mg, one-time) exposure to zerovalent AgNPs. Plant enzymatic and biochemical stress responses were assessed using superoxide dismutase (SOD) and peroxidase (POD) activity, malondialdehyde (MDA) concentrations and chlorophyll content as markers of defense and phytotoxicity, respectively. The high initial pulse treatment resulted in rapid changes in physiological characteristics and silver concentration in plant tissue at the beginning of each AgNPs exposure (6 h, 36 h, and 9 days), while continuous AgNP and sulfidized AgNP chronic treatments gave delayed responses. Both E. densa and J. effusus enhanced their tolerance to AgNPs toxicity by increasing POD and SOD activities to scavenge free radicals but at different growth phases. Chlorophyll did not change. After AgNPs exposure, MDA, an index of membrane damage, was higher in submerged E. densa than emergent J. effusus, which suggested that engineered nanoparticles exerted more stress to submerged macrophytes.

An assessment of the microbiological quality and safety of raw drinking milk on retail sale in England.

AIMS: This study aimed to review the microbiological results for raw drinking milk (RDM) samples submitted to Public Health England laboratories between 2014 and 2016 in order to produce up-to-date data on the microbiological safety of RDM and inform future risk assessments on its sale. METHODS AND RESULTS: A total of 902 samples of RDM were collected from retail sale in England for microbiological examination. Overall, 454 of 770 samples (59·0%) taken for routine monitoring were of a satisfactory quality, whilst eight (1·0%) were 'unsatisfactory and potentially injurious to health' due to the presence of Shiga toxin-producing Escherichia coli, Campylobacter or elevated levels of Listeria monocytogenes or coagulase-positive staphylococci. In contrast, 16 of 114 (14·0%) of samples taken in follow-up to a previous unsatisfactory result and 5 of 18 (27·8%) of samples related to illness were potentially injurious. A total of 229 of 902 samples (25·4%) gave unsatisfactory results due to elevated aerobic colony counts and/or coliforms, whilst 139 of 902 samples (15·4%) were of borderline quality due to coagulase-positive staphylococci. Listeria monocytogenes was detected at levels of <100 CFU per ml in 66 of 902 samples (7·3%) and other Listeria species in 44 of 902 samples (4·9%). CONCLUSIONS: Pathogens and/or indicators of poor hygiene were present in almost half of samples examined. Cows' milk samples gave a significantly greater proportion of unsatisfactory results compared to milk from other species (i.e. goat, sheep, buffalo, camel). SIGNIFICANCE AND IMPACT OF THE STUDY: These results demonstrate the importance of maintaining strict controls on the production and sale of this product.