Development of a novel off-grid drinking water production system integrating electrochemically activated solutions and ultrafiltration membranes

© 2017 Elsevier Ltd Approximately 800 million people live without clean drinking water. Diarrhoea is responsible for between 1.7 and 2 million deaths each year (primarily children) which are the result of poor drinking water quality and sanitation. The main aim of this study was to demonstrate the production of drinking water from a raw water source using an off-grid drinking water production system. The off-grid drinking water production system (DWPS) developed at UWE Bristol, combines an ultra-filtration (UF) system with in situ generation of electrochemically activated solutions (ECAS). ECAS has two functional roles within the system; to manage biofilms within the UF system and as a disinfectant. Integrated in-situ probes (pH, oxidation reduction potential, chlorine, conductivity and dissolved oxygen) coupled with a water quality sensing network (pH, water temperature, conductivity and dissolved oxygen) enabled real time monitoring of; the operational efficiency of the DWPS, and the physicochemical parameters of both the raw water source and the produced drinking water. Spot samples of both raw and treated water were sent for independent chemical and microbial analysis at an accredited laboratory which demonstrated that the DWPS produced biologically safe potable drinking water according to the Drinking Water Inspectorate (DWI) standards. Samples from the raw water source were shown to be consistently unsuitable for human consumption, failing several of the DWI standards for potable water supply, including coliform bacteria. This study demonstrated that the novel off-grid DWPS was capable of producing DWI standard drinking water from a heavily biologically contaminated water source

Assessing the antimicrobial potential of aerosolised electrochemically activated solutions (ECAS) for reducing the microbial bio-burden on fresh food produce held under cooled or cold storage conditions

© 2017 The main aim of this study was to assess the antimicrobial efficacy of electrochemically activated fog (ECAF) for reducing the microbial bio-burden on artificially inoculated fresh produce held under cooled (cucumber and vine tomatoes) or cold (rocket and broccoli) storage conditions. The ECAF treatment (1100 ± 5 mV ORP; 50 ± 5 mg L−1 free chlorine; 2.7 ± 0.1 pH) resulted in a significant log reduction in the potential pathogen E. coli recovered from rocket (2.644 Log10 CFU g−1), broccoli (4.204 Log10 CFU g−1), cucumber (3.951 Log10 CFU g−1) and tomatoes (2.535 Log10 CFU g-1) after 5 days. ECAF treatment also resulted in a significant log reduction in potential spoilage organisms, whereby a 3.533 Log10 CFU g−1, 2.174 Log10 CFU g−1 and 1.430 Log10 CFU g−1 reduction in presumptive Pseudomonads was observed for rocket, broccoli and cucumber respectively, and a 3.527 Log10 CFU g−1 reduction in presumptive Penicillium spp. was observed for tomatoes (after 5 days). No adverse visual effects on produce were recorded. The results of this study will inform industrial scale-up trials within commercial facilities (assessing shelf-life, microbial quality and organoleptic assessment) to assess the developed ECAF technology platform within a real food processing environment

Constructing a coherent STEM strategy with schools

Most universities run STEM enrichment activities with local schools. At UWE we have run activities with respect to mathematics (Maths Challenge, Maths Event Day, FUNMaths Roadshows), Engineering (Engineering activity day, Bloodhound), Science (Science Awareness Day, Hands on Science Day, Bristol Festival of Nature). In contrast, the University of Plymouth as well as subject specific events, run a STEM activity incorporating all three STEM subject (Science, Engineering and Mathematics). This activity is rolled out to schools in the region throughout June. Both approaches have merit. We propose to share practice between the University of Plymouth and UWE through staff visits with the objective of setting up and piloting at UWE a STOP type project as currently run at the University of Plymout

In vitro discrimination of wound-associated bacteria by volatile compound profiling using selected ion flow tube-mass spectrometry

© 2017 The Society for Applied Microbiology Aims: To determine if bacterial species responsible for clinically relevant wound infection produce specific volatile profiles that would allow their speciation. Methods and Results: Selected ion flow tube-mass spectrometry (SIFT-MS) in full mass scan mode was used to analyse headspace gases produced by wound-associated bacteria grown invitro, so as to enable identification of bacterial volatile product ion profiles in the resulting mass spectra. Applying multivariate statistical analysis (hierarchical clustering and principal component analysis) to the resultant mass spectra enabled clear speciation. Moreover, bacterial volatile product ions could be detected from artificially contaminated wound dressing material, although the pattern of product ions detected was influenced by culture conditions. Conclusions: Using selected product ions from the SIFT-MS mass spectra it is possible to discriminate wound-associated bacterial species grown under specific invitro culture conditions. Significance and Impact of the Study: The results of this study have shown that wound-associated bacteria can be discriminated using volatile analysis invitro and that bacterial volatiles can be detected from wound dressing material. This indicates that volatile analysis of wounds or dressing material to identify infecting microbes has potential and warrants further study

Genome sequence of vB_AbaS_TRS1, a viable prophage isolated from Acinetobacter baumannii strain A118

© 2016 Turner et al. A novel temperate phage, vB_AbaS_TRS1, was isolated from cultures of Acinetobacter baumannii strain A118 that had been exposed to mitomycin C. Phage TRS1 belongs to the Siphoviridae family of bacteriophages and encapsulates a 40,749-bp genome encoding 70 coding sequences and a single tRNA

Microbial processing and production of aquatic fluorescent organic matter in a model freshwater system

© 2018 by the authors. Organic matter (OM) has an essential biogeochemical influence along the hydrological continuum and within aquatic ecosystems. Organic matter derived via microbial processes was investigated within a range of model freshwater samples over a 10-day period. For this, excitation-emission matrix (EEM) fluorescence spectroscopy in combination with parallel factor (PARAFAC) analysis was employed. This research shows the origin and processing of both protein-like and humic-like fluorescence within environmental and synthetic samples over the sampling period. The microbial origin of Peak T fluorescence is demonstrated within both synthetic samples and in environmental samples. Using a range of incubation temperatures provides evidence for the microbial metabolic origin of Peak T fluorescence. From temporally resolved experiments, evidence is provided that Peak T fluorescence is an indication of metabolic activity at the microbial community level and not a proxy for bacterial enumeration. This data also reveals that humic-like fluorescence can be microbially derived in situ and is not solely of terrestrial origin, likely to result from the upregulation of cellular processes prior to cell multiplication. This work provides evidence that freshwater microbes can engineer fluorescent OM, demonstrating that microbial communities not only process, but also transform, fluorescent organic matter

Laboratory in-situ production of autochthonous and allochthonous fluorescent organic matter by freshwater bacteria

This work investigates the origin and range of fluorescent organic matter (FOM) produced in-situ by environmentally sourced freshwater bacteria. Aquatic FOM is an essential component in global carbon cycling and is generally classified as either autochthonous, produced in-situ via microbial processes, or allochthonous, transported into aquatic systems from external sources. We have demonstrated that, within laboratory model systems, environmentally sourced mixed microbial communities and bacterial isolates can produce and/or export FOM associated with both autochthonous and allochthonous material. This study focuses on fluorescence peak B, T, M, C and C+, exploring (1) the cellular nature of FOM produced, (2) FOM exported as extracellular material into the water column and (3) the impact of physical cell lysis on FOM signature. For the laboratory model systems studied, Peak T fluorescence is retained within bacterial cells (>68%), while Peak C fluorescence is mainly observed as extracellular material (>80%). Peak M is identified as both cellular and extracellular FOM, produced by all isolated freshwater microorganisms investigated. The origin of Peak C+ is postulated to originate from functional metabolites associated with specific microorganisms, seen specifically within the Pseudomonas sp. monoculture here. This work challenges the binary classification of FOM as either allochthonous or autochthonous, suggesting that FOM processing and production occurs along a dynamic continuum. Within this study, fluorescence intensity data for the environmental bacteria isolate monocultures are presented as enumeration corrected data, for the first time providing quantitative fluorescence data per bacterial colony forming unit (cfu). From this, we are able to assess the relative contribution of different bacteria to the autochthonous FOM pool and if this material is cellular or extracellular

HOCl vs OCl−: clarification on chlorine-based disinfectants used within clinical settings

Disinfection is a mainstay of infection prevention, the importance of which was highlighted throughout the SARS-CoV-2 pandemic. There is frequent misuse of terminology surrounding chlorine solutions in the literature. This leads not only to confusion but has potentially dangerous outcomes, as inappropriate mixing of chlorine solutions with other disinfectants or cleaning solutions can lead to the release of chlorine gas. This article provides a resource for accurate terminology surrounding chlorine-based disinfection and clarifies some of the key inaccuracies, including the pH-dependent nature of chlorine species distribution of hypochlorous acid (HOCl) (neutral/acidic chlorine solution) and hypochlorite (OCl-) (alkaline chlorine solution). Misuse and misunderstanding of chlorine solutions and the terminology used can be harmful therefore this is an essential resource for those utilising chlorine as a disinfectant

The in situ production of aquatic fluorescent organic matter in a simulated freshwater laboratory model

Dissolved organic matter (DOM) is ubiquitous throughout aquatic systems. Fluorescence techniques can be used to characterize the fluorescing proportion of DOM, aquatic fluorescent organic matter (AFOM). AFOM is conventionally named in association with specific fluorescence “peaks,” which fluoresce in similar optical regions as microbially-derived proteinaceous material (Peak T), and terrestrially-derived humic-like compounds (Peaks C/C+), with Peak T previously being investigated as a tool for bacterial enumeration within freshwaters. The impact of anthropogenic nutrient loading on the processing of DOM by microbial communities is largely unknown. Previous laboratory studies utilizing environmental freshwater have employed growth media with complex background fluorescence, or very high nutrient concentrations, preventing the investigation of AFOM production under a range of more representative nutrient concentrations within a matrix exhibiting very low background fluorescence. We describe a laboratory-based model with Pseudomonas aeruginosa that incorporates a low fluorescence growth matrix consisting of a simulated freshwater (SFW), representative of low-hardness freshwater systems allowing controlled nutrient conditions to be studied. The effects of microbial processing of DOM as a function of available nitrogen, phosphorous, and dissolved organic carbon (DOC) in the form of glucose were investigated over 48 h at highly resolved time increments. The model system demonstrates the production of a range of complex AFOM peaks in the presence and absence of DOC, revealing no linear relationship between cell numbers and any of the peaks for the bacterial species studied, with AFOM peaks increasing with microbial cell number, ranging from 55.2 quinine sulfate units (QSU) per 106 cells to 155 QSU per 106 cells (p < 0.05) for Peak T during the exponential growth phase of P. aeruginosa under high nutrient conditions with 5 mg L−1 DOC. Nutrient and DOC concentration was found to cause differential production of autochthonous- or allochthonous-like AFOM, with lower DOC concentrations resulting in higher Peak T production relative to Peaks C/C+ upon the addition of nutrients, and high DOC concentrations resulting in higher Peak C/C+ production relative to Peak T. Our results show the production of allochthonous-like AFOM from a simple and non-fluorescent carbon source, and provide uncertainty in the use of Peak T as a reliable surrogate for specific bacterial enumeration, particularly in dynamic or nutrient-impacted environments, pointing toward the use of fluorescence as an indicator for microbial metabolism

Differential Drug Survival of Biologic Therapies for the Treatment of Psoriasis: A Prospective Observational Cohort Study from the British Association of Dermatologists Biologic Interventions Register (BADBIR)

Drug survival reflects a drug’s effectiveness, safety, and tolerability. We assessed the drug survival of biologics used to treat psoriasis in a prospective national pharmacovigilance cohort (British Association of Dermatologists Biologic Interventions Register (BADBIR)). The survival rates of the first course of biologics for 3,523 biologic-naive patients with chronic plaque psoriasis were compared using survival analysis techniques and predictors of discontinuation analyzed using a multivariate Cox proportional hazards model. Data for patients on adalimumab (n=1,879), etanercept (n=1,098), infliximab (n=96), and ustekinumab (n=450) were available. The overall survival rate in the first year was 77%, falling to 53% in the third year. Multivariate analysis showed that female gender (hazard ratio (HR) 1.22; 95% confidence interval (CI): 1.09–1.37), being a current smoker (HR 1.19; 95% CI: 1.03–1.38), and a higher baseline dermatology life quality index (HR 1.01; 95% CI: 1.00–1.02) were predictors of discontinuation. Presence of psoriatic arthritis (HR 0.82; 95% CI: 0.71–0.96) was a predictor for drug survival. As compared with adalimumab, patients on etanercept (HR 1.63; 95% CI: 1.45–1.84) or infliximab (HR 1.56; 95% CI: 1.16–2.09) were more likely to discontinue therapy, whereas patients on ustekinumab were more likely to persist (HR 0.48; 95% CI: 0.37–0.62). After accounting for relevant covariates, ustekinumab had the highest first-course drug survival. The results of this study will aid clinical decision making when choosing biologic therapy for psoriasis patients