1,019 research outputs found

    Clonal expansion within pneumococcal serotype 6C after use of seven-valent vaccine

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    Streptococcus pneumoniae causes invasive infections, primarily at the extremes of life. A seven-valent conjugate vaccine (PCV7) is used to protect against invasive pneumococcal disease in children. Within three years of PCV7 introduction, we observed a fourfold increase in serotype 6C carriage, predominantly due to a single clone. We determined the whole-genome sequences of nineteen S. pneumoniae serotype 6C isolates, from both carriage (n = 15) and disease (n = 4) states, to investigate the emergence of serotype 6C in our population, focusing on a single multi-locus sequence type (MLST) clonal complex 395 (CC395). A phylogenetic network was constructed to identify different lineages, followed by analysis of variability in gene sets and sequences. Serotype 6C isolates from this single geographical site fell into four broad phylogenetically distinct lineages. Variation was seen in the 6C capsular locus and in sequences of genes encoding surface proteins. The largest clonal complex was characterised by the presence of lantibiotic synthesis locus. In our population, the 6C capsular locus has been introduced into multiple lineages by independent capsular switching events. However, rapid clonal expansion has occurred within a single MLST clonal complex. Worryingly, plasticity exists within current and potential vaccine-associated loci, a consideration for future vaccine use, target selection and design

    Targeted mutagenesis in a human-parasitic nematode.

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    Parasitic nematodes infect over 1 billion people worldwide and cause some of the most common neglected tropical diseases. Despite their prevalence, our understanding of the biology of parasitic nematodes has been limited by the lack of tools for genetic intervention. In particular, it has not yet been possible to generate targeted gene disruptions and mutant phenotypes in any parasitic nematode. Here, we report the development of a method for introducing CRISPR-Cas9-mediated gene disruptions in the human-parasitic threadworm Strongyloides stercoralis. We disrupted the S. stercoralis twitchin gene unc-22, resulting in nematodes with severe motility defects. Ss-unc-22 mutations were resolved by homology-directed repair when a repair template was provided. Omission of a repair template resulted in deletions at the target locus. Ss-unc-22 mutations were heritable; we passed Ss-unc-22 mutants through a host and successfully recovered mutant progeny. Using a similar approach, we also disrupted the unc-22 gene of the rat-parasitic nematode Strongyloides ratti. Our results demonstrate the applicability of CRISPR-Cas9 to parasitic nematodes, and thereby enable future studies of gene function in these medically relevant but previously genetically intractable parasites

    Spatial radionuclide deposition data from the 60 km radial area around the Chernobyl nuclear power plant: results from a sampling survey in 1987

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    The data set “Spatial radionuclide deposition data from the 60 radial km area around the Chernobyl nuclear power plant: results from a sampling survey in 1987” is the latest in a series of data to be published by the Environmental Information Data Centre (EIDC) describing samples collected and analysed following the Chernobyl Nuclear Power Plant accident in 1986. The data result from a survey carried out by the Ukrainian Institute of Agricultural Radiology (UIAR) in April and May 1987 and includes sample site information, dose rate, radionuclide (zirconium-95, niobium-95, ruthenium-106, caesium-134, caesium-137 and cerium-144) deposition, and exchangeable (determined following 1M NH4Ac extraction of soils) caesium-134 and 137. The purpose of this paper is to describe the available data and methodology used for sample collection, sample preparation and analysis. The data will be useful in reconstructing doses to human and wildlife populations, answering the current lack of scientific consensus on the effects of radiation on wildlife in the Chernobyl Exclusion Zone and evaluating future management options for the Chernobyl-impacted areas of Ukraine and Belarus. The data and supporting documentation are freely available from the EIDC under the terms and conditions of the Open Government Licence (Kashparov et al., 2019; https://doi.org/10.5285/a408ac9d-763e-4f4c-ba72-73bc2d1f596d)

    Nonstandard lumbar region in predicting fracture risk

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    Background: Femoral neck BMD is the most commonly used skeletal site to estimate fracture risk. The role of lumbar spine BMD in fracture risk prediction is less clear due to osteophytes that spuriously increase LS BMD, particularly at lower levels. The aim of this study was to compare fracture predictive ability of upper L1-L2 BMD compared to standard L2-L4 BMD and assess whether the addition of either lumbar spine site could improve fracture prediction over FN BMD. Methodology: A prospective cohort of 3016 women and men 60+ years from the Dubbo Osteoporosis Epidemiology Study followed for occurrence of minimal trauma fractures from 1989 to 2014. DXA was used to measure bone mineral density at f L1-L2, L2-L4 and FN at baseline. Fracture risks were estimated using Cox proportional hazards models separately for each site. Predictive performances were compared using ROC curve analyses Results:There were 565 women and 179 men with a minimal trauma fracture during a mean of 11±7 years. L1-L2 BMD T-score was significantly lower than L2-L4 T-score in both genders (p Conclusion: In an elderly population, L1-L2 is as good as but not better than L2-L4 site in predicting fracture risk. The addition of LS BMD to FN BMD provided a modest additional benefit in overall fracture risk. Further studies in individuals with spinal degenerative disease are needed

    Inorganic−Organic Hybrid Luminescent Binary Probe for DNA Detection Based on Spin-Forbidden Resonance Energy Transfer

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    We describe the design of new fluorescent binary probe sensors for DNA detection based on spin-forbidden resonance energy transfer (SF-RET). Binary probes consist of a donor and acceptor fluorophores that are attached to two different oligonucleotides and serve as a resonance energy transfer (RET) donor−acceptor pair when hybridized to adjacent sites of a target sequence. In the absence of target, excitation of the donor results in fluorescence only from the donor, but when the probes hybridize to the target, the fluorophores are brought into close proximity favoring RET, yielding fluorescence mainly from the acceptor fluorophore. These new binary probes use the metal complex Ru(bpy‘)(DIP)_2^(2+) as the energy donor and an organic fluorophore (Cy5) as the energy acceptor. Energy transfer from the MLCT state of the Ru complex to singlet Cy5 is spin forbidden and produces a delayed fluorescence of Cy5. This paper demonstrates that fluorescence delay of Cy5 can be used to time resolve the emission of the probe from the intense fluorescence background of a model system for cellular background; this provides the reported system to overcome intense autofluorescence, an important and general advantage over “classical” spin-allowed steady-state probes

    Pole dancing for fitness: The physiological and metabolic demand of a 60-minute class

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    Nicholas, JC, McDonald, KA, Peeling, P, Jackson, B, Dimmock, JA, Alderson, JA, and Donnelly, CJ. Pole dancing for fitness: The physiological and metabolic demand of a 60-minute class. J Strength Cond Res 33(10): 2704–2710, 2019—Little is understood about the acute physiological or metabolic demand of pole dancing classes. As such, the aims of this study were to quantify the demands of a standardized recreational pole dancing class, classifying outcomes according to American College of Sports Medicine (ACSM) exercise-intensity guidelines, and to explore differences in physiological and metabolic measures between skill- and routine-based class components. Fourteen advanced-level amateur female pole dancers completed three 60-minute standardized pole dancing classes. In one class, participants were fitted with a portable metabolic analysis unit. Overall, classes were performed at a mean Vo2 of 16.0 ml·kg−1·min−1, total energy cost (EC) of 281.6 kcal (4.7 kcal·min−1), metabolic equivalent (METs) of 4.6, heart rate of 131 b·min−1, rate of perceived exertion (RPE) of 6.3/10, and blood lactate of 3.1 mM. When comparing skill- and routine-based components of the class, EC per minute (4.4 vs. 5.3 kcal·min−1), peak Vo2 (21.5 vs. 29.6 ml·kg−1·min−1), METs (4.3 vs. 5.2), and RPE (7.2 vs. 8.4) were all greater in the routine-based component (p \u3c 0.01), indicating that classes with an increased focus on routine-based training, as compared to skill-based training, may benefit those seeking to exercise at a higher intensity level, resulting in greater caloric expenditure. In accordance with ASCM guidelines, an advanced-level 60-minute pole dancing class can be classified as a moderate-intensity cardiorespiratory exercise; when completed for ≥ 30 minutes, ≥ 5 days per week (total ≥ 150 minutes) satisfies the recommended level of exercise for improved health and cardiorespiratory fitness
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