Surface proteins that promote adherence of Staphylococcus aureus to human desquamated nasal epithelial cells

<p>Abstract</p> <p>Background</p> <p>The natural habitat of <it>Staphylococcus aureus </it>is the moist squamous epithelium in the anterior nares. About 20% of the human population carry <it>S. aureus </it>permanently in their noses and another 60% of individuals are intermittent carriers. The ability of <it>S. aureus </it>to colonize the nasal epithelium is in part due to expression of surface proteins clumping factor B (ClfB) and the iron-regulated surface determinant A (IsdA), which promote adhesion to desquamated epithelial cells present in the anterior part of the nasal vestibule. <it>S. aureus </it>strain Newman defective in IsdA and ClfB exhibited reduced but not completely defective adherence to squamous cells in indicating that other cell surface components might also contribute.</p> <p>Results</p> <p>Surface proteins IsdA, ClfB, and the serine-aspartic acid repeat proteins SdrC, SdrD and SdrE were investigated to determine their contribution to the adherence of <it>S. aureus </it>to desquamated nasal epithelial cells. This was achieved by expression of ClfB, IsdA, SdrC, SdrD and SdrE on the surface of the surrogate Gram-positive host <it>Lactococcus lactis </it>and by isolating mutants of <it>S. aureus </it>Newman defective in one or more factor. The level of adherence of strains to squamous cells isolated from the nares of volunteers was measured. Results consistently showed that ClfB, IsdA, SdrC and SdrD each contributed to the ability of <it>S. aureus </it>to adhere to squamous cells. A mutant lacking all four proteins was completely defective in adherence.</p> <p>Conclusion</p> <p>The ability of <it>S. aureus </it>Newman to adhere to desquamated nasal epithelial cells is multifactorial and involves SdrD and SdrC as well as ClfB and IsdA.</p

Endophytic Trichoderma spp. can protect strawberry and privet plants from infection by the fungus Armillaria mellea

Armillaria mellea is an important fungal pathogen worldwide, affecting a large number of hosts in the horticulture and forestry industries. Controlling A. mellea infection is expensive, labour intensive and time-consuming, so a new, environmentally friendly management solution is required. To this effect, endophytic Trichoderma species were studied as a potential protective agent for Armillaria root rot (ARR) in strawberry and privet plants. A collection of forty endophytic Trichoderma isolates were inoculated into strawberry (Fragaria × ananassa) plants and plant growth was monitored for two months, during which time Trichoderma treatment had no apparent effect. Trichoderma-colonised strawberry plants were then inoculated with A. mellea and after three months plants were assessed for A. mellea infection. There was considerable variation in ARR disease levels between plants inoculated with different Trichoderma spp. isolates, but seven isolates reduced ARR below the level of positive controls. These isolates were further tested for protective potential in Trichoderma-colonized privet (Ligustrum vulgare) plants where five Trichoderma spp. isolates, including two highly effective Trichoderma atrobrunneum isolates, were able to significantly reduce levels of disease. This study highlights the potential of plants pre-colonised with T. atrobrunneum for effective protection against A. mellea in two hosts from different plant families

An automated image analysis framework for segmentation and division plane detection of single live Staphylococcus aureus cells which can operate at millisecond sampling time scales using bespoke Slimfield microscopy

Staphylococcus aureus is an important pathogen, giving rise to antimicrobial resistance in cell strains such as Methicillin Resistant S. aureus (MRSA). Here we report an image analysis framework for automated detection and image segmentation of cells in S. aureus cell clusters, and explicit identification of their cell division planes. We use a new combination of several existing analytical tools of image analysis to detect cellular and subcellular morphological features relevant to cell division from millisecond time scale sampled images of live pathogens at a detection precision of single molecules. We demonstrate this approach using a fluorescent reporter GFP fused to the protein EzrA that localises to a mid-cell plane during division and is involved in regulation of cell size and division. This image analysis framework presents a valuable platform from which to study candidate new antimicrobials which target the cell division machinery, but may also have more general application in detecting morphologically complex structures of fluorescently labelled proteins present in clusters of other types of cells

Six-Year Incidence of Blindness and Visual Impairment in Kenya: The Nakuru Eye Disease Cohort Study.

PURPOSE: To describe the cumulative 6-year incidence of visual impairment (VI) and blindness in an adult Kenyan population. The Nakuru Posterior Segment Eye Disease Study is a population-based sample of 4414 participants aged ?50 years, enrolled in 2007-2008. Of these, 2170 (50%) were reexamined in 2013-2014. METHODS: The World Health Organization (WHO) and US definitions were used to calculate presenting visual acuity classifications based on logMAR visual acuity tests at baseline and follow-up. Detailed ophthalmic and anthropometric examinations as well as a questionnaire, which included past medical and ophthalmic history, were used to assess risk factors for study participation and vision loss. Cumulative incidence of VI and blindness, and factors associated with these outcomes, were estimated. Inverse probability weighting was used to adjust for nonparticipation. RESULTS: Visual acuity measurements were available for 2164 (99.7%) participants. Using WHO definitions, the 6-year cumulative incidence of VI was 11.9% (95%CI [confidence interval]: 10.3-13.8%) and blindness was 1.51% (95%CI: 1.0-2.2%); using the US classification, the cumulative incidence of blindness was 2.70% (95%CI: 1.8-3.2%). Incidence of VI increased strongly with older age, and independently with being diabetic. There are an estimated 21 new cases of VI per year in people aged ?50 years per 1000 people, of whom 3 are blind. Therefore in Kenya we estimate that there are 92,000 new cases of VI in people aged ?50 years per year, of whom 11,600 are blind, out of a total population of approximately 4.3 million people aged 50 and above. CONCLUSIONS: The incidence of VI and blindness in this older Kenyan population was considerably higher than in comparable studies worldwide. A continued effort to strengthen the eye health system is necessary to support the growing unmet need in an aging and growing population

Stat2 loss disrupts damage signalling and is protective in acute pancreatitis

The severity of sterile inflammation, as seen in acute pancreatitis, is determined by damage-sensing receptors, signalling cascades and cytokine production. Stat2 is a type I interferon signalling mediator that also has interferon-independent roles in murine lipopolysaccharide-induced NF-κB-mediated sepsis. However, its role in sterile inflammation is unknown. We hypothesised that Stat2 determines the severity of non-infective inflammation in the pancreas. Wild type (WT) and Stat2-/- mice were injected intraperitoneally with caerulein or L-arginine. Specific cytokine-blocking antibodies were used in some experiments. Pancreata and blood were harvested 1 h and 24 h after the final dose of caerulein and up to 96 h post L-arginine. Whole-tissue phosphoproteomic changes were assessed using label-free mass spectrometry. Tissue-specific Stat2 effects were studied in WT/Stat2-/- bone-marrow chimera and using Cre-lox recombination to delete Stat2 in pancreatic and duodenal homeobox 1(Pdx1)-expressing cells. Stat2-/- mice were protected from caerulein- and L-arginine-induced pancreatitis. Protection was independent of type I interferon signalling. Stat2-/- mice had lower cytokine levels including TNFα and IL-10 and reduced NF-kB nuclear localisation in pancreatic tissue compared to WT. Inhibition of TNFα improved (inhibition of IL-10 worsened) caerulein-induced pancreatitis in WT but not Stat2-/- mice. Phosphoproteomics showed down-regulation of mitogen-activated protein kinase (MAPK) mediators but accumulation of Ser412-phosphorylated Tak1. Stat2 deletion in Pdx1-expressing acinar cells (Stat2flox/Pdx1-cre ) reduced pancreatic TNFα expression, but not histological injury or serum amylase. WT/Stat2-/- bone-marrow chimera mice were protected from pancreatitis irrespective of host or recipient genotype. Stat2 loss results in disrupted signalling in pancreatitis, upstream of NF-κB in non-acinar and/or bone marrow derived cells. This article is protected by copyright. All rights reserved

The COMPLETE Survey of Star-Forming Regions: Phase I Data

We present an overview of data available for the Ophiuchus and Perseus molecular clouds from ``Phase I'' of the COMPLETE Survey of Star-Forming Regions. This survey provides a range of data complementary to the Spitzer Legacy Program ``From Molecular Cores to Planet Forming Disks.'' Phase I includes: Extinction maps derived from 2MASS near-infrared data using the NICER algorithm; extinction and temperature maps derived from IRAS 60 and 100um emission; HI maps of atomic gas; 12CO and 13CO maps of molecular gas; and submillimetre continuum images of emission from dust in dense cores. Not unexpectedly, the morphology of the regions appears quite different depending on the column-density tracer which is used, with IRAS tracing mainly warmer dust and CO being biased by chemical, excitation and optical depth effects. Histograms of column-density distribution are presented, showing that extinction as derived from 2MASS/NICER gives the closest match to a log-normal distribution as is predicted by numerical simulations. All the data presented in this paper, and links to more detailed publications on their implications are publically available at the COMPLETE website.Comment: Accepted by AJ. Full resolution version available from: http://www.cfa.harvard.edu/COMPLETE/papers/complete_phase1.pd

Implementation of an electronic monitoring and evaluation system for the antiretroviral treatment programme in the Cape Winelands district, South Africa: a qualitative evaluation

BACKGROUND: A pragmatic three-tiered approach to monitor the world's largest antiretroviral treatment (ART) programme was adopted by the South African National Department of Health in 2010. With the rapid expansion of the programme, the limitations of the paper-based register (tier 1) were the catalyst for implementation of the stand-alone electronic register (tier 2), which offers simple digitisation of the paper-based register. This article engages with theory on implementation to identify and contextualise enabling and constraining factors for implementation of the electronic register, to describe experiences and use of the register, and to make recommendations for implementation in similar settings where standardisation of ART monitoring and evaluation has not been achieved. METHODS: We conducted a qualitative evaluation of the roll-out of the register. This comprised twenty in-depth interviews with a diverse sample of stakeholders at facility, sub-district, and district levels of the health system. Facility-level participants were selected across five sub-districts, including one facility per sub-district. Responses were coded and analysed using a thematic approach. An implementation science framework guided interpretation of the data. Results & DISCUSSION: We identified the following seven themes: 1) ease of implementation, 2) perceived value of an electronic M&E system, 3) importance of stakeholder engagement, 4) influence of a data champion, 5) operational and logistical factors, 6) workload and role clarity, and 7) importance of integrating the electronic register with routine facility monitoring and evaluation. Interpreting our findings through an implementation theory enabled us to construct the scaffolding for implementation across the five facility-settings. This approach illustrated that implementation was not a linear process but occurred at two nodes: at the adoption of the register for roll-out, and at implementation at facility-level. CONCLUSION: In this study we found that relative advantage of an intervention and stakeholder engagement are critical to implementation. We suggest that without these aspects of implementation, formative and summative outcomes of implementation at both the adoption and coalface stages of implementation would be negatively affected

Dental and craniofacial defects in the Crtap−/− mouse model of osteogenesis imperfecta type VII

BackgroundInactivating mutations in the gene for cartilage‐associated protein (CRTAP) cause osteogenesis imperfecta type VII in humans, with a phenotype that can include craniofacial defects. Dental and craniofacial manifestations have not been a focus of case reports to date. We analyzed the craniofacial and dental phenotype of Crtap−/− mice by skull measurements, micro‐computed tomography (micro‐CT), histology, and immunohistochemistry.ResultsCrtap−/− mice exhibited a brachycephalic skull shape with fusion of the nasofrontal suture and facial bones, resulting in mid‐face retrusion and a class III dental malocclusion. Loss of CRTAP also resulted in decreased dentin volume and decreased cellular cementum volume, though acellular cementum thickness was increased. Periodontal dysfunction was revealed by decreased alveolar bone volume and mineral density, increased periodontal ligament (PDL) space, ectopic calcification within the PDL, bone‐tooth ankylosis, altered immunostaining of extracellular matrix proteins in bone and PDL, increased pSMAD5, and more numerous osteoclasts on alveolar bone surfaces.ConclusionsCrtap−/− mice serve as a useful model of the dental and craniofacial abnormalities seen in individuals with osteogenesis imperfecta type VII.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155878/1/dvdy166.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155878/2/dvdy166_am.pd

Desenvolvimento de um novo instrumento online de avaliação do consumo alimentar para crianças portuguesas em idade escolar : abordagem qualitativa

© Creative Commons 3.0Introduction: Twenty-four-hour dietary recall is the method of choice for assessing food intake among school-age children. Because they require highly trained interviewers, recalls are expensive and impractical for large-scale nutrition research. A new method for assessing dietary intake in children is being developed: the Portuguese self-administered computerized 24-hour dietary recall (PAC24). Objectives: To identify and select food items to comprise PAC24; to better understand the way children report their food consumption on the previous day; and, to know the different meanings and labeling children give to some specific food items. Methods: Data were collected through 21 Focus Groups (FG), conducted in 7 primary schools from the 7 regions of Portugal in 2011. 204 children from second to fourth grade participated. FG were homogeneous for children’s grade and area of residence and heterogeneous for gender and socioeconomic status. Children participated in FG after parent’s written informed consent. Topics for discussion were food consumption on the previous day and individual meanings and labeling of some specific food items. Content analysis followed a thematic coding process. Results: Regarding food consumption on the previous day, 3997 food items were identified and grouped into 12 food groups. Children generally reported foods chronologically organized by the three main meals (breakfast, lunch and dinner). Snacks and candies consumption were reported after prompting for snacks and forgotten foods. Not all children were able to record foods successfully; both descriptions and quantities of food posed problems. Different regional culture-specific terms were identified for some of the food-items. Conclusions: This qualitative approach enriched the food-items pool that was originally developed by literature review and revealed the main aspects that should be taken into account in PAC24 development