242 research outputs found

    Practical microbiology in schools: a survey of UK teachers

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    A survey of secondary school teachers investigated practical microbiology in the classroom. The results were heartening (practical microbiology was common), but concerns were expressed regarding equipment, time, cost, and expertise. Microbiologists should engage more with school education to support teachers and maintain the health of microbiology for future generations

    Reproducibility of Bacterial Cellulose Nanofibers Over Sub-Cultured Generations for the Development of Novel Textiles

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    The textile industry is in crisis and under pressure to minimize the environmental impact on its practices. Bacterial cellulose (BC), a naturally occurring form of cellulose, displays properties superior to those of its cotton plant counterpart, such as enhanced purity, crystallinity, tensile strength, and water retention and is thus suitable for an array of textile applications. It is synthesized from a variety of microorganisms but is produced in most abundance by Komagataeibacter xylinus. K. xylinus is available as a type strain culture and exists in the microbial consortium commonly known as Kombucha. Whilst existing literature studies have described the effectiveness of both K. xylinus isolates and Kombucha in the production of BC, this study investigated the change in microbial communities across several generations of sub-culturing and the impact of these communities on BC yield. Using Kombucha and the single isolate strain K. xylinus as inocula in Hestrin and Schramm liquid growth media, BC pellicles were propagated. The resulting pellicles and residual liquid media were used to further inoculate fresh liquid media, and this process was repeated over three generations. For each generation, the thickness of the pellicles and their appearance under SEM were recorded. 16S rRNA sequencing was conducted on both pellicles and liquid media samples to assess changes in communities. The results indicated that the genus Komagataeibacter was the most abundant species in all samples. Cultures seeded with Kombucha yielded thicker cellulose pellicles than those seeded with K. xylinus, but all the pellicles had similar nanofibrillar structures, with a mix of liquid and pellicle inocula producing the best yield of BC after three generations of sub-culturing. Therefore, Kombucha starter cultures produce BC pellicles which are more reproducible across generations than those created from pure isolates of K. xylinus and could provide a reproducible sustainable model for generating textile materials

    Quantifying the pattern of microbial cell dispersion, density and clustering on surfaces of differing chemistries and topographies using multifractal analysis

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    The effects of surface topography on bacterial distribution across a surface are of extreme importance when designing novel, hygienic or antimicrobial surface coatings. The majority of methods that are deployed to describe the pattern of cell dispersion, density and clustering across surfaces are currently qualitative. This paper presents a novel application of multifractal analysis to quantitatively measure these factors using medically relevant microorganisms (Staphylococcus aureus or Staphylococcus epidermidis). Surfaces (medical grade 316 stainless steel) and coatings (Ti–ZrN, Ti–ZrN/6.0%Ag, Ti–ZrN/15.6%Ag, TiZrN/24.7%Ag) were used in microbiological retention assays. Results demonstrated that S. aureus displayed a more heterogeneous cell dispersion (∆αAS < 1) whilst the dispersion of S. epidermidis was more symmetric and homogeneous (∆αAS ≥ 1). Further, although the surface topography and chemistry had an effect on cell dispersion, density and clustering, the type of bonding that occurred at the surface interface was also important. Both types of cells were influenced by both surface topographical and chemical effects; however, S. aureus was influenced marginally more by surface chemistry whilst S. epidermidis cells was influenced marginally more by surface topography. Thus, this effect was bacterially species specific. The results demonstrate that multifractal analysis is a method that can be used to quantitatively analyse the cell dispersion, density and clustering of retained microorganisms on surfaces. Using quantitative descriptors has the potential to aid the understanding the effect of surface properties on the production of hygienic and antimicrobial coatings

    Nano-layered inorganic-organic hybrid materials for the controlled delivery of antimicrobials

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    An essential oil (EO) blend has been identified that provides a broad spectrum potent antimicrobial effect. Adsorption of the EO onto porous silicate materials (Rockwood Additives: Laponite® B, Laponite® RD and Fulcat® 800) and has been analysed and it was found that Laponite® RD organically modified with dihydrogenated tallow dimethyl ammonium chloride (2HT2M) at 50% cation exchange capacity gave the highest levels of adsorption. The Laponite® RD 2HT2M with EO blend adsorbed has been added to polymer materials to produce an antimicrobial polymer. The adsorption of the EO onto the Laponite® RD was done to achieve controlled release of the EO to prolong the antimicrobial effect within the polymer. Addition of the EO loaded substrates into silicone elastomer has resulted in successfully conferring a high level of antimicrobial activity to the polymer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    SimFection: a digital resource for vaccination education

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    © 2018 Royal Society of Biology. Vaccination coverage in the United Kingdom is below the level recommended by the World Health Organisation, and when vaccination coverage is not sufficient, outbreaks of infectious diseases can occur. In 2015, coverage of the first dose of the Measles-Mumps-Rubella vaccine declined in the United Kingdom for the first time since 2008, indicating a need to raise public awareness and understanding of the importance of vaccination to public health. Identifying 16 – 18-year olds as a target audience, being future parents who would make decisions regarding vaccination of their children, a digital educational resource (‘SimFection’) was developed to deliver key messages about the spread and control of vaccine-preventable infectious diseases (identified via school curricula). The process of development utilised an iterative approach, involving a cyclic process of prototyping, testing, analysis and refinement with a range of audiences including students, schoolchildren, and trainee teachers. The completed resource is now available online for free download

    China’s Weibo: is faster different?

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    The popularization of microblogging in China represents a new challenge to the state’s regime of information control. The speed with which information is diffused in the microblogosphere has helped netizens to publicize and express their discontent with the negative consequences of economic growth, income inequalities and official corruption. In some cases, netizen led initiatives have facilitated the mobilization of online public opinion and forced the central government to intervene to redress acts of lower level malfeasance. However, despite the growing corpus of such cases, the government has quickly adapted to the changing internet ecology and is using the same tools to help it maintain control of society by enhancing its claims to legitimacy, circumscribing dissent, identifying malfeasance in its agents and using online public opinion to adapt policy and direct propaganda efforts. This essay reflects on microblogging in the context of the Chinese internet, and argues that successes in breaking scandals and mobilizing opinion against recalcitrant officials should not mask the reality that the government is utilizing the microblogosphere to its own advantage

    Seeing the baby, doing family: commercial ultrasound as family practice?

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    Medical sociologists and anthropologists have studied the social significance of obstetric ultrasound for families but little is known about how women and families make use of commercially available ultrasound scans. This article draws on interviews with women who booked a scan with a commercial company in the UK. For some women, commercial ultrasound can be understood as a family practice. We investigate this theme by examining who accompanies women to commercial scan appointments, how scan images are shared and how sonograms are used as prompts to resemblance talk. We argue that commercial scans are more than an additional opportunity to acquire ‘baby’s first picture’ and offer a flexible resource to do family, creating and affirming family relationships and rehearsing roles as parents, siblings and grandparents. Our findings confirm the importance of imagination in doing family and raise questions about the role of technology and commercial interests in shaping family practices

    How Do We Determine the Efficacy of an Antibacterial Surface? A Review of Standardised Antibacterial Material Testing Methods

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    Materials that confer antimicrobial activity, be that by innate property, leaching of biocides or design features (e.g., non-adhesive materials) continue to gain popularity to combat the increasing and varied threats from microorganisms, e.g., replacing inert surfaces in hospitals with copper. To understand how efficacious these materials are at controlling microorganisms, data is usually collected via a standardised test method. However, standardised test methods vary, and often the characteristics and methodological choices can make it difficult to infer that any perceived antimicrobial activity demonstrated in the laboratory can be confidently assumed to an end-use setting. This review provides a critical analysis of standardised methodology used in academia and industry, and demonstrates how many key methodological choices (e.g., temperature, humidity/moisture, airflow, surface topography) may impact efficacy assessment, highlighting the need to carefully consider intended antimicrobial end-use of any product

    The effects of blood conditioning films on the antimicrobial and retention properties of zirconium-nitride silver surfaces

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    External bone fixation devices provide support and rehabilitation for severely damaged/broken bones, however, this invasive procedure is prone to infection. Zirconium nitride/silver (Ti-ZrN/Ag) coatings were characterised for surface topography, chemical composition, physicochemistry and antimicrobial efficacy (against Staphylococcus aureus and Staphylococcus epidermidis), in the presence of a blood conditioning film. The conditioning film altered the width of the microtopography of the surfaces however, the depth of the features remained relatively constant. The conditioning film also altered the coatings from hydrophobic to hydrophilic/partially hydrophilic surfaces. Following the MATH assay, the presence of a conditioning film reduced affinity towards the hydrocarbons for both microorganisms. The addition of a blood conditioning film reduced the antimicrobial efficacy of the Ti-ZrN/Ag coatings but also reduced the number of retained bacteria. This study suggests that the presence of a pre-defined blood conditioning film may result in surfaces with anti-adhesive properties, potentially leading to a reduction in bacterial retention. This, combined with the antimicrobial efficacy of the coatings, could reduce the risk of infection on biomaterial surfaces
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