184 research outputs found

    A comparative analysis of the cephalic microbiome: The ocular, aural, nasal/nasopharyngeal, oral and facial dermal niches

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    The human face/head supports a highly diverse population of microorganisms across a diverse range of microhabitats. This biogeographical diversity has given rise to selection pressure resulting in the formation of distinct bacterial communities between sites. This review investigates the similarity and differences of microbiomes across the different biogeographies of the human face and discusses a potential pathway for microbial circulation within individuals and within a population to maintain microbiome niches and diversity

    Antibacterial efficiency over time and barrier properties of wood coatings with colloidal silver

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    This work aims to represent a standard application for understanding the extent of the antibacterial efficacy of coatings with different amounts of colloidal silver on wooden surfaces over time. The key variable that was intended to be evaluated in this study was the "time efficiency," with concerns about the possible efficacy in the durability of the surfaces. By highlighting the "expiry date" of the agents, as in the case with other products, the study aimed to confirm the validity of the simulation tests conducted in the laboratory with degradation tests. Furthermore, the role of the silver amount on the barrier performance of the coatings was assessed by liquid resistance, water uptake, and perspiration tests, evaluating the aesthetic durability of the coatings by means of colorimetric analyses. Ultimately, this work demonstrates that these coatings may represent alternatives in terms of prolonged antimicrobial activity when compared with the biocide agents currently in use, capable to offer good resistance to detergent solutions and to water. Nevertheless, due to silver's susceptibility to extended exposure to acidic solutions, the findings of the research discourage the utilization of colloidal silver in wood paints intended for use in public settings

    Comparative analysis of ocular surface tissue microbiome in human, mouse, rabbit, and guinea pig

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    Animal models are a critical element of ocular surface research for investigating therapeutic drops, surgical implants, and infection research. This study was a comparative analysis of the microbial communities on conjunctival tissue samples from humans compared to several commonly used laboratory animals (BALB/c mice, New Zealand white rabbits and IMVS colored stock guinea pigs). Microbial communities were analyzed by extracting total DNA from conjunctival tissue and sequencing the 16 S rRNA gene using the Illumina MiSeq platform. Sequences were quality filtered using the UNOISE pipeline in USEARCH and taxonomically classified using GTDB database. Sequences associated with blank extraction and sampling negative controls were removed with the decontam R software package prior to downstream analysis. There was a difference in the diversity measures of richness (P = 0.0124) and Shannon index (P = 0.0002) between humans and rabbits but not between human, mouse and guinea pigs. There was a difference between the human and any animal for bacterial community structure (P = 0.006). There was a higher degree of similarity between the bacterial composition of the human and mouse samples with each dominated by the phyla Proteobacteria and Firmicutes. The use of mouse models may be more appropriate for studies investigating changes to the ocular microbiome due to interventions such as application of antibiotics due to greater similarities in bacterial community structure and composition to humans

    Colloidal silver as innovative multifunctional pigment: The effect of Ag concentration on the durability and biocidal activity of wood paints

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    This study aims to assess the effect of two different colloidal silver amount on the durability and biocidal activity of a water-borne wood paint. The influence of this multifunctional pigment on the aesthetical features of the coatings was evaluated by colorimetric measurements and optical microscopy observations. The durability of the samples was investigated by means of different accelerated degradation tests, such as the exposure in a climatic chamber and to UV-B radiations. Scanning electron microscope observations, infrared spectroscopy analysis and colorimetric inspections were carried out to highlight the residual influence of silver in altering the protective behavior of the paint. Moreover, the Ag-containing samples exhibited excellent antibacterial activity against Staphylococcus aureus and Escherichia coli, while colloidal silver did not introduce effective fungicidal performances against Coniophora puteana and Trametes versicolor fungi. Ultimately, this work demonstrates how colloidal silver can be used as a functional pigment in wood paint, capable of modifying the appearance of the coating, improving its antibacterial performance, without negatively affecting its protective performance

    Facile route to effective antimicrobial aluminum oxide layer realized by co-deposition with silver nitrate

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    The emergence and spreading of the SARS-CoV-2 pandemic has forced the focus of attention on a significant issue: the realization of antimicrobial surfaces for public spaces, which do not require extensive use of disinfectants. Silver represents one of the most used elements in this context, thanks to its excellent biocidal performance. This work describes a simple method for the realization of anodized aluminum layers, whose antimicrobial features are ensured by the co-deposition with silver nitrate. The durability and the chemical resistance of the samples were evaluated by means of several accelerated degradation tests, such as the exposure in a salt spray chamber, the contact with synthetic sweat and the scrub test, highlighting the residual influence of silver in altering the protective behavior of the alumina layers. Furthermore, the ISO 22196:2011 standard was used as the reference protocol to set up an assay to measure the effective antibacterial activity of the alumina-Ag layers against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, even at low concentrations of silver. Finally, the Ag-containing aluminum oxide layers exhibited excellent antimicrobial performances also following the chemical–physical degradation processes, ensuring good durability over time of the antimicrobial surfaces. Overall, this work introduces a simple route for the realization of anodized aluminum surfaces with excellent antibacterial properties

    Microbiological environmental monitoring in high-risk departments during building activities in a hospital site

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    Background. This study examines the microbial and fungal contamination associated with the presence of renovation works in a hospital site in Sardinia (Italy). Methods. Microbiological environmental monitoring was carried out before, during and at the conclusion of the works in the Ophthalmology Department in view of a risk assessment procedure. Results. Although the median values of microbial and fungal counts were found raised during the works, protective measures set out by the internal procedures limited the contamination level. Conclusions. This study emphasizes the benefits of environmental surveillance for airborne contamination to help prevent outbreaks of nosocomial mycosis associated with construction work

    Consecutive dosing of UVB irradiation induces loss of ABCB5 expression and activation of EMT and fibrosis proteins in limbal epithelial cells similar to pterygium epithelium

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    Pterygium pathogenesis is often attributed to a population of altered limbal stem cells, which initiate corneal invasion and drive the hyperproliferation and fibrosis associated with the disease. These cells are thought to undergo epithelial to mesenchymal transition (EMT) and to contribute to subepithelial stromal fibrosis. In this study, the presence of the novel limbal stem cell marker ABCB5 in clusters of basal epithelial pterygium cells co-expressing with P63α and P40 is reported. ABCB5-positive pterygium cells also express EMT-associated fibrosis markers including vimentin and α-SMA while their β-catenin expression is reduced. By using a novel in vitro model of two-dose UV-induced EMT activation on limbal epithelial cells, we could observe the dysregulation of EMT-related proteins including an increase of vimentin and α-SMA as well as downregulation of β-catenin in epithelial cells correlating to downregulation of ABCB5. The sequential irradiation of limbal fibroblasts also induced an increase in vimentin and α-SMA. Taken together, these data demonstrate for the first time the expression of ABCB5 in pterygium stem cell activity and EMT-related events while the involvement of limbal stem cells in pterygium pathogenesis is exhibited via sequential irradiation of limbal epithelial cells. The later in vitro approach can be used to further study the involvement of limbal epithelium UV-induced EMT in pterygium pathogenesis and help identify novel treatments against pterygium growth and recurrence

    Visualisation of peripheral retinal degenerations and anomalies with ocular imaging

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    Purpose: Certain peripheral retinal degenerations pose a significant risk to vision and require prompt detection and management. Other historically “benign” peripheral lesions are being recognised as clinically significant due to their associations with ocular and systemic disorders. Assessment and documentation of these entities however can be difficult due to challenges in visualisation of the peripheral retina. This review addresses this by providing a series of clinical examples of these entities visualised with a variety of ocular imaging technologies. Methods: A literature search was performed in Embase, Medline, and Google Scholar. We identified and analysed all papers referring to peripheral retinal degenerations and the peripheral retina, as well as reference lists of retrieved articles until August 2019. Results: Using ocular imaging technologies including ultra-widefield imaging and peripheral optical coherence tomography, we comprehensively describe current evidence and knowledge of a number of peripheral retinal degenerations and anomalies including microcystoid, pavingstone, lattice, snail track, snowflake and reticular pigmentary degenerations, peripheral drusen, white without pressure, retinal holes and vitreoretinal tufts. A summary of these entities is also provided as a short and easily interpretable chairside guide to facilitate the translation of this evidence base into clinical practice. Conclusion: While ocular technologies are useful in visualising peripheral retinal degenerations, the current evidence is fragmented throughout the literature and there is a paucity of information on imaging of “benign” peripheral lesions. This review facilitates a multimodal imaging approach to evaluating peripheral lesions

    Time spent outdoors in childhood is associated with reduced risk of myopia as an adult

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    Myopia (near-sightedness) is an important public health issue. Spending more time outdoors can prevent myopia but the long-term association between this exposure and myopia has not been well characterised. We investigated the relationship between time spent outdoors in childhood, adolescence and young adulthood and risk of myopia in young adulthood. The Kidskin Young Adult Myopia Study (KYAMS) was a follow-up of the Kidskin Study, a sun exposure-intervention study of 1776 children aged 6–12 years. Myopia status was assessed in 303 (17.6%) KYAMS participants (aged 25–30 years) and several subjective and objective measures of time spent outdoors were collected in childhood (8–12 years) and adulthood. Index measures of total, childhood and recent time spent outdoors were developed using confirmatory factor analysis. Logistic regression was used to assess the association between a 0.1-unit change in the time outdoor indices and risk of myopia after adjusting for sex, education, outdoor occupation, parental myopia, parental education, ancestry and Kidskin Study intervention group. Spending more time outdoors during childhood was associated with reduced risk of myopia in young adulthood (multivariable odds ratio [OR] 0.82, 95% confidence interval [CI] 0.69, 0.98). Spending more time outdoors in later adolescence and young adulthood was associated with reduced risk of late-onset myopia (≥ 15 years of age, multivariable OR 0.79, 95% CI 0.64, 0.98). Spending more time outdoors in both childhood and adolescence was associated with less myopia in young adulthood

    Rationale and protocol for the 7- And 8-year longitudinal assessments of eye health in a cohort of young adults in the Raine Study

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    Introduction Eye diseases and visual impairment more commonly affect elderly adults, thus, the majority of ophthalmic cohort studies have focused on older adults. Cohort studies on the ocular health of younger adults, on the other hand, have been few. The Raine Study is a longitudinal study that has been following a cohort since their birth in 1989-1991. As part of the 20-year follow-up of the Raine Study, participants underwent a comprehensive eye examination. As part of the 27- and 28-year follow-ups, eye assessments are being conducted and the data collected will be compared with those of the 20-year follow-up. This will provide an estimate of population incidence and updated prevalence of ocular conditions such as myopia and keratoconus, as well as longitudinal change in ocular parameters in young Australian adults. Additionally, the data will allow exploration of the environmental, health and genetic factors underlying inter-subject differential long-term ocular changes. Methods and analysis Participants are being contacted via telephone, email and/or social media and invited to participate in the eye examination. At the 27-year follow-up, participants completed a follow-up eye screening, which assessed visual acuity, autorefraction, ocular biometry and ocular sun exposure. Currently, at the 28-year follow-up, a comprehensive eye examination is being conducted which, in addition to all the eye tests performed at the 27-year follow-up visit, includes tonometry, optical coherence tomography, funduscopy and anterior segment topography, among others. Outcome measures include the incidence of refractive error and pterygium, an updated prevalence of these conditions, and the 8-year change in ocular parameters. Ethics and dissemination The Raine Study is registered in the Australian New Zealand Clinical Trials Registry. The Gen2 20-year, 27-year and 28-year follow-ups are approved by the Human Research Ethics Committee of the University of Western Australia. Findings resulting from the study will be published in health or medical journals and presented at conferences. Trial registration number ACTRN12617001599369; Active, not recruiting
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