Microbial contamination of food refrigeration equipment

Refrigeration systems in chilled rooms in 15 plants processing a variety of foods were studied. These included plants processing raw meat and salads, Chinese ready meals, dairy products, slicing and packing of cooked meats and catering establishments. An initial survey of total numbers of microbes at a total of 891 sites on evaporators, drip trays and chilled room walls was followed up with a more detailed examination of 336 sites with high counts, selecting for Listeria spp., coliforms, enterococci, Staphylococcus aureus and Bacillus cereus. Temperatures (particularly air on and air off, maximum and near defrost heaters) relative humidity, airflow, layout and cleaning regimes were surveyed. In general, no correlation could be found between any of the physical measurements and the numbers and types of bacteria detected. Maximum mean temperatures in the chilled rooms varied from -1 to +16.9 °C and few chilled units were regularly cleaned. Twenty five percent of sites examined had more than 105 colony-forming units per cm2, although, very few pathogens or faecal indicator bacteria were detected. Listeria spp. were not found and coliforms were found only once, in low numbers. Low numbers of S. aureus or B. cereus were present in 9 of the 15 plants, B. cereus was found on evaporators and associated drip trays in two catering plants and two plants processing cooked meat. Enterococci and S. aureus were found most frequently in a raw red meat slaughterhouse (always in low numbers). In general, microbial contamination was lower in rooms where wrapped rather than unwrapped products were stored. The type of product also affected the degree of contamination, with raw red meat and poultry or dry ingredients giving highest counts, and raw vegetables and cooked products lowest. The work demonstrated that bacteria were present on evaporator cooling coils in all factory cold rooms visited. Although evaporator-cleaning procedures were carried out in some factories as part of routine maintenance these were not shown to be effective at maintaining low levels of bacteria on evaporators. To maintain evaporator hygiene it is suggested that more regular cleaning procedures, possibly by means of automated cleansing systems, should be considered. © 2003 Elsevier Ltd. All rights reserved

Translating solid state organic synthesis from a mixer mill to a continuous twin screw extruder

A study on the translation of a solid-state synthetic reaction from a mechanochemical mixer-mill to a continuous twin-screw extruder is discussed herein. The study highlights some considerations to be made and parameters to be tested in the context of a model fluorination reaction, which is the first organic fluorination to be attempted using extrusion. Upon optimization, which features the first use of grinding auxiliary solids to enable effective synthetic extrusion, the difluorination reaction was successfully translated to the extruder, leading to a 100-fold improvement in Space Time Yield (STY); 29 kg m−3 day−1 in a mixer mill to 3395 kg m−3 day−1 in a twin screw extruder

Toward the definition of efficacy and safety criteria for advancing gene drive-modified mosquitoes to field testing

Mosquitoes containing gene drive systems are being developed as complementary tools to prevent transmission of malaria and other mosquito-borne diseases. As with any new tool, decision makers and other stakeholders will need to balance risks (safety) and benefits (efficacy) when considering the rationale for testing and deploying gene drive-modified mosquito products. Developers will benefit from standards for judging whether an investigational gene drive product meets acceptability criteria for advancing to field trials. Such standards may be formalized as preferred product characteristics and target product profiles, which describe the desired attributes of the product category and of a particular product, respectively. This report summarizes discussions from two scientific workshops aimed at identifying efficacy and safety characteristics that must be minimally met for an investigational gene drive-modified mosquito product to be deemed viable to move from contained testing to field release and the data that will be needed to support an application for first field release

Exploring cavities in Type II porous liquids with xenon

The porous topology of Type II Porous Liquids (PLs), prepared using Noria-OEt as an empty molecular host dissolved in 15-crown-5 solvent, is investigated with 129Xe NMR Spectroscopy. Xenon NMR parameters, such as chemical shifts and T1 relaxation times, measured in PLs solutions prepared at various Noria-OEt concentrations, are related to the intrinsic microporous structure of the material. The experimental data are interpreted on the basis of a multiple-site model for xenon atoms within the multiple PLs cavities. Diffusion NMR experiments show a similar mobility of xenon in PLs compared with the pure solvent.(c) 2022 Elsevier B.V. All rights reserved

Characterisation of innate immune viral sensors in patients following allogeneic haematopoietic stem cell transplantation

Virus infection is a major cause of morbidity and mortality following allogeneic haematopoietic stem cell transplant (HSCT), with up to 1 in 4 deaths directly linked to viral disease. Whilst awaiting lymphocyte reconstitution post HSCT, the innate anti-viral immune response is the first line of defence against invading viruses. Several novel innate viral sensing pathways have recently been characterized, but their physiological importance in humans is poorly understood. We analysed a panel of innate viral sensor genes in HSCT patients, and assessed whether differences in innate anti-viral responses could account for variation in susceptibility to viral infections. Expression levels of innate viral sensors in HSCT patients with active viral infections, HSCT patient without active infections, and healthy volunteers were highly homogenous. Although IFNα expression was upregulated in actively-infected patients relative to controls, a corresponding upregulation of innate viral sensor expression was not observed. IFNα stimulation of patient peripheral blood mononuclear cells (PBMCs) in-vitro showed intact IFNα signaling, but actively-infected patients’ PBMCs had reduced upregulation of innate viral sensors. We show that the aberrant IFNα responses in HSCT patients were not due to calcineurin inhibition. Our data therefore raises the possibility of an intrinsic defect in innate viral sensor upregulation in HSCT patients following viral infection.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by a Junior Research Fellowship to SLC from Magdalene College, Cambridge. This work was supported by the Medical Research Council MC_U105181010

Improving Phrap-Based Assembly of the Rat Using “Reliable” Overlaps

The assembly methods used for whole-genome shotgun (WGS) data have a major impact on the quality of resulting draft genomes. We present a novel algorithm to generate a set of “reliable” overlaps based on identifying repeat k-mers. To demonstrate the benefits of using reliable overlaps, we have created a version of the Phrap assembly program that uses only overlaps from a specific list. We call this version PhrapUMD. Integrating PhrapUMD and our “reliable-overlap” algorithm with the Baylor College of Medicine assembler, Atlas, we assemble the BACs from the Rattus norvegicus genome project. Starting with the same data as the Nov. 2002 Atlas assembly, we compare our results and the Atlas assembly to the 4.3 Mb of rat sequence in the 21 BACs that have been finished. Our version of the draft assembly of the 21 BACs increases the coverage of finished sequence from 93.4% to 96.3%, while simultaneously reducing the base error rate from 4.5 to 1.1 errors per 10,000 bases. There are a number of ways of assessing the relative merits of assemblies when the finished sequence is available. If one views the overall quality of an assembly as proportional to the inverse of the product of the error rate and sequence missed, then the assembly presented here is seven times better. The UMD Overlapper with options for reliable overlaps is available from the authors at http://www.genome.umd.edu. We also provide the changes to the Phrap source code enabling it to use only the reliable overlaps

Protocol for a mixed methods process evaluation of the Smoking Treatment Optimisation in Pharmacies (STOP) trial

This article is a preprint from medRxiv and has not been peer-reviewe

Assessing the effect of reducing agents on the selective catalytic reduction of NO<inf>x</inf> over Ag/Al<inf>2</inf>O<inf>3</inf> catalysts

The selective catalytic reduction (SCR) of NOx in the presence of different reducing agents over Ag/Al2O3 prepared by wet impregnation was investigated by probing catalyst activity and using NMR relaxation time analysis.We gratefully acknowledge funding for this work from the EPSRC CASTech grant (EP/G012156/1). Carmine D’Agostino would like to acknowledge Wolfson College, Cambridge, for supporting his research activities. The authors would also like to thank Dr Jonathan Mitchell for useful discussions.This is the final version of the article. It first appeared from RSC via http://dx.doi.org/10.1039/C5CY01508

Multiple communication mechanisms between sensor kinases are crucial for virulence in Pseudomonas aeruginosa

This is the author accepted manuscript. The final version is available as an open access article from the publisher via the DOI in this recordBacteria and many non-metazoan Eukaryotes respond to stresses and threats using two-component systems (TCSs) comprising sensor kinases (SKs) and response regulators (RRs). Multikinase networks, where multiple SKs work together, detect and integrate different signals to control important lifestyle decisions such as sporulation and virulence. Here, we study interactions between two SKs from Pseudomonas aeruginosa, GacS and RetS, which control the switch between acute and chronic virulence. We demonstrate three mechanisms by which RetS attenuates GacS signalling: RetS takes phosphoryl groups from GacS-P; RetS has transmitter phosphatase activity against the receiver domain of GacS-P; and RetS inhibits GacS autophosphorylation. These mechanisms play important roles in vivo and during infection, and exemplify an unprecedented degree of signal processing by SKs that may be exploited in other multikinase networks.This work was supported by the Medical Research Council (MRC) (grant number MR/ M020045/1), the Leverhulme Trust (grant number RPG-2014-228), the RoseTrees Trust (grant number M328) and a NERC PhD studentship (grant number 1076449)