DNA fingerprinting of S. typhimurium from a pig longitudinal study

A 400 sow farrow-to-finish farm was sampled for 6 consecutive years to determine the persistence of Salmonella Typhimurium (STM) DT104. Pulsed-field gel electrophoresis, plasmid DNA analysis and antibiotic resistance phenotyping was carried out on selected STM strains, isolated from the farm during the time of the study. Clonal persistence as well and introduction of new clones from external sources were proven to be the main mechanisms by which salmonella infection was maintained in the farm

Efficacy of the mRNA-1273 SARS-CoV-2 vaccine at completion of blinded phase

BACKGROUND At interim analysis in a phase 3, observer-blinded, placebo-controlled clinical trial, the mRNA-1273 vaccine showed 94.1% efficacy in preventing coronavirus disease 2019 (Covid-19). After emergency use of the vaccine was authorized, the protocol was amended to include an open-label phase. Final analyses of efficacy and safety data from the blinded phase of the trial are reported. METHODS We enrolled volunteers who were at high risk for Covid-19 or its complications; participants were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 μg) or placebo, 28 days apart, at 99 centers across the United States. The primary end point was prevention of Covid-19 illness with onset at least 14 days after the second injection in participants who had not previously been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The data cutoff date was March 26, 2021. RESULTS The trial enrolled 30,415 participants; 15,209 were assigned to receive the mRNA-1273 vaccine, and 15,206 to receive placebo. More than 96% of participants received both injections, 2.3% had evidence of SARS-CoV-2 infection at baseline, and the median follow-up was 5.3 months in the blinded phase. Vaccine efficacy in preventing Covid-19 illness was 93.2% (95% confidence interval [CI], 91.0 to 94.8), with 55 confirmed cases in the mRNA-1273 group (9.6 per 1000 person-years; 95% CI, 7.2 to 12.5) and 744 in the placebo group (136.6 per 1000 person-years; 95% CI, 127.0 to 146.8). The efficacy in preventing severe disease was 98.2% (95% CI, 92.8 to 99.6), with 2 cases in the mRNA-1273 group and 106 in the placebo group, and the efficacy in preventing asymptomatic infection starting 14 days after the second injection was 63.0% (95% CI, 56.6 to 68.5), with 214 cases in the mRNA-1273 group and 498 in the placebo group. Vaccine efficacy was consistent across ethnic and racial groups, age groups, and participants with coexisting conditions. No safety concerns were identified. CONCLUSIONS The mRNA-1273 vaccine continued to be efficacious in preventing Covid-19 illness and severe disease at more than 5 months, with an acceptable safety profile, and protection against asymptomatic infection was observed

DNA fingerprinting of S. typhimurium from a pig longitudinal study

A 400 sow farrow-to-finish farm was sampled for 6 consecutive years to determine the persistence of Salmonella Typhimurium (STM) DT104. Pulsed-field gel electrophoresis, plasmid DNA analysis and antibiotic resistance phenotyping was carried out on selected STM strains, isolated from the farm during the time of the study. Clonal persistence as well and introduction of new clones from external sources were proven to be the main mechanisms by which salmonella infection was maintained in the farm.</p

A survey of fluoroquinolone resistance in E. coli and thermophilic Campylobacter spp. on poultry and pig farms in Great Britain

Aims: To estimate the proportions of farms on which broilers, turkeys and pigs were shedding fluoroquinolone (FQ)-resistant E. coli or Campylobacter spp. near to slaughter. Methods and Results: Freshly-voided faeces were collected on 89 poultry and 108 pig farms and cultured with media containing 1.0 mg l-1 ciprofloxacin. Studies demonstrated the specificity of this sensitive method, and both poultry and pig sampling yielded FQ-resistant E. coli on 60% of farms. FQ-resistant Campylobacter spp. were found on around 22% of poultry and 75% of pig farms. The majority of resistant isolates of Campylobacter (89%) and E. coli (96%) tested had minimum inhibitory concentrations for ciprofloxacin of ≥8 mg l-1. The proportion of resistant E. coli and Campylobacter organisms within samples varied widely. Conclusions: FQ resistance is commonly present among two enteric bacterial genera prevalent on pig and poultry farms, although the low proportion of resistant organisms in many cases requires a sensitive detection technique. Significance and Impact of Study: FQ-resistant bacteria with zoonotic potential appear to be present on a high proportion of UK pig and poultry farms. The risk this poses to consumers relative to other causes of FQ-resistant human infections remains to be clarified.</p

Insights and guidance for putting integrated natural resources management into practice in Africa at meso-scale

Natural resources in Africa are under increasing pressure to sustain the continent’s growing economies and populations, as well as competition for access to Africa’s resources from global economies. Management of these resources has become imperative to prevent over-utilisation and ensure that the local custodians of the resources are able to benefit in the long-term. Natural Resource Management (NRM) in Africa is a complex problem, needing to balance demands across different stakeholders, sectors and scales, in a context where governance is often uncoordinated and under-resourced. Integrated Natural Resource Management (INRM) encompasses the concept that natural resources are not only important for direct use, but are critical in supporting basic service provision, local economic development and social well-being. Although the concepts of INRM have been in play in Africa since the late 1980s (Hagmann et al., 2001) and the principles widely accepted, implementation in operational planning and management has been limited. Campbell et al. (2004) concluded ‘Our seeming inability to translate the approaches into practical achievements on the ground is leading to widespread disillusionment. …. What is surprising is not the improvement of approaches over the past 40 years – rather it is their fundamental similarity.’ This conclusion establishes a challenge to provide practical tools that can assist in translating concepts into improved outcomes on the ground. We need to entrench an integrated approach in the practice of NRM and associated governance frameworks. The AfroMaison project was instituted under the European Union’s 7th Framework Programme to address the challenges of making INRM in Africa operational. The project worked with five geographically and culturally diverse case studies, namely: Tunisia (Oum Zessar Watershed); Mali (Inner Niger Delta); Ethiopia (headwaters of the Blue Nile); Uganda (Rwenzori Mountains); and South Africa (uThukela District)

National survey for Salmonella in pigs, cattle and sheep at slaughter in Great Britain (1999-2000).

AIMS: The objective of these surveys was to estimate the prevalence of faecal carriage of Salmonella in healthy pigs, cattle and sheep at slaughter, and of pig carcase contamination with Salmonella. These data can be used as a baseline against which future change in Salmonella prevalence in these species at slaughter can be monitored. METHODS AND RESULTS: In this first randomized National Survey for faecal carriage of Salmonella in slaughter pigs, cattle and sheep in Great Britain, 2509 pigs, 891 cattle and 973 sheep were sampled in 34 pig abattoirs and 117 red meat abattoirs in England, Scotland and Wales. Carriage of Salmonella in 25 g caecal contents was identified in 578 (23.0% pigs) but in only 134 (5.3%) of carcase swabs. The predominant Salmonella serovars found in both types of sample were S. Typhimurium (11.1% caeca, 2.1% carcases) and S. Derby (6.3% caeca, 1.6% carcases). The main definitive phage types (DT) of S. Typhimurium found were DT104 (21.9% of caecal S. Typhimurium isolates), DT193 (18.7%), untypable strains (17.6%), DT208 (13.3%) and U302 (13.3%). Three isolates of S. Enteritidis (PTs 13A and 4) and one enrofloxacin-resistant S. Choleraesuis were also isolated. A positive 'meat-juice ELISA' was obtained from 15.2% of pigs at 40% optical density (O.D.) cut-off level and 35.7% at 10% cut-off. There was poor correlation between positive ELISA results or carcase contamination and the caecal carriage of Salmonella. The ratio of carcase contamination to caecal carriage rates was highest in abattoirs from the midland region of England and in smaller abattoirs. In cattle and sheep 1 g samples of rectal faeces were tested. Two isolates (i.e. 0.2%) were recovered from cattle, one each of S. Typhimurium, DT193 and DT12. One sheep sample (0.1%) contained a Salmonella, S. Typhimurium DT41. In a small subsidiary validation exercise using 25 g of rectal faeces from 174 cattle samples, three (1.7%) isolates of Salmonella (S. Typhimurium DT104, S. Agama, S. Derby) were found. CONCLUSIONS: The carriage rate of Salmonella in prime slaughter cattle and sheep in Great Britain was very low compared with pigs. This suggests that future control measures should be focused on reduction of Salmonella infection on pig farms and minimizing contamination of carcases at slaughter. SIGNIFICANCE AND IMPACT OF THE STUDY: This work has set baseline figures for Salmonella carriage in these species slaughtered for human consumption in Great Britain. These figures were collected in a representative way, which enables them to be used for monitoring trends and setting control targets