Healthcare-associated outbreak of meticillin-resistant Staphylococcus aureus bacteraemia: role of a cryptic variant of an epidemic clone

BACKGROUND New strains of meticillin-resistant Staphylococcus aureus (MRSA) may be associated with changes in rates of disease or clinical presentation. Conventional typing techniques may not detect new clonal variants that underlie changes in epidemiology or clinical phenotype. AIM To investigate the role of clonal variants of MRSA in an outbreak of MRSA bacteraemia at a hospital in England. METHODS Bacteraemia isolates of the major UK lineages (EMRSA-15 and -16) from before and after the outbreak were analysed by whole-genome sequencing in the context of epidemiological and clinical data. For comparison, EMRSA-15 and -16 isolates from another hospital in England were sequenced. A clonal variant of EMRSA-16 was identified at the outbreak hospital and a molecular signature test designed to distinguish variant isolates among further EMRSA-16 strains. FINDINGS By whole-genome sequencing, EMRSA-16 isolates during the outbreak showed strikingly low genetic diversity (P < 1 × 10(-6), Monte Carlo test), compared with EMRSA-15 and EMRSA-16 isolates from before the outbreak or the comparator hospital, demonstrating the emergence of a clonal variant. The variant was indistinguishable from the ancestral strain by conventional typing. This clonal variant accounted for 64/72 (89%) of EMRSA-16 bacteraemia isolates at the outbreak hospital from 2006. CONCLUSIONS Evolutionary changes in epidemic MRSA strains not detected by conventional typing may be associated with changes in disease epidemiology. Rapid and affordable technologies for whole-genome sequencing are becoming available with the potential to identify and track the emergence of variants of highly clonal organisms

PERBEDAAN TINGKAT PENGETAHUAN KESEHATAN REPRODUKSI PADA REMAJA MAHASISWA FAKULTAS KEDOKTERAN DAN FAKULTAS ILMU SOSIAL DAN ILMU POLITIK UNIVERSITAS DIPONEGORO

Background: The awareness of reproductive health are increasing, namely HIV/AIDS, unwanted pregnancy and unsafe abortion. This indicates that knowledge of reproductive health is important. This research aimed to identify reproductive health knowledge in adolescent difference, including aspects of anatomy and physiology of the reproductive system, gender and sexuality, pregnancy and risk of teenage pregnancy, contraception, and sexually transmitted diseases among students of the Faculty of Medicine and the Faculty of Social and Political Sciences Diponegoro University. Methods: This research design was observational analytic with cross-sectional method, conducted from March until June 2011. The research subjects were students who meet the inclusion and exclusion criteria, collected by purposive random sampling method. Data was obtained from the questionnaire and analyzed with univariate and bivariate analysis. Univariate analysis was used to determine frequency distributions analysis and bivariate analysis used chi square test (x2) to identify significance. Results: Faculty of Medicine students of whom reproductive health knowledge level was categorized as good (55,1%), average (39,8%), and less (5,1%). Faculty of Social and Political Sciences students of whom reproductive health knowledge level was categorized as good (5%), average (67,3%), and less (27,6%). There are significant differences in reproductive health knowledge levels between students of those two faculty (p=0.000). Conclusion: The reproductive health knowledge level of Faculty of Medicine students is higher than Faculty of Social and Political Sciences students and significantly different. Keywords: adolescent, reproductive health knowledg

Neurotrophic factor receptors and their signal transduction capabilities in rat astrocytes

Until recently, astrocytes were not considered as sites for neurotrophic factor action. We show here that, both in vivo and in vitro, astrocytes express receptors for two separate families of neurotrophic factors. In the intact adult rat CNS, astrocytes express the extracellular domain of the neurotrophin receptor TrkB and, in a more restricted population, the low-affinity nerve growth factor receptor p75(LNGFR). In the lesioned CNS, expression of the alpha component of the receptor for ciliary neurotrophic factor (CNTFRα) switches from a purely neuronal localization to cells in the glial scar at the edge of the wound. Using cultured hippocampal astrocytes as a model to address the functional status of these receptors, we have found only the truncated forms of TrkB and TrkC, which are incapable of signal transduction as measured by protein tyrosine phosphorylation or immediate early gene induction. In contrast, a fully functional CNTF receptor complex capable of signal transduction is present on cultured astrocytes. Thus, the neurotrophin receptors may act primarily to sequester or present the neurotrophins, whereas in the case of CNTF a functional response can be initiated within the astrocyte

Detecting Feature Interactions: How Many Components Do We Need?

Features are a structuring mechanism for &lt;i&gt;additional&lt;/i&gt; functionality, usually in response to changing requirements. When several features are invoked at the same time, by the same, or different components, the features may not interwork. This is known as &lt;i&gt;feature interaction&lt;/i&gt;. We employ a property-based approach to feature interaction detection: this involves checking the validity (or not) of a temporal property against a given system model. We use the logic LTL for temporal properties and the model-checker Spin to prove properties. To gain any real insight into feature interactions, it is important to be able to infer properties for networks of &lt;i&gt;any&lt;/i&gt; size, regardless of the underlying communication structure. We present an inference mechanism based on abstraction. The key idea is to model-check a system consisting of a constant number (&lt;i&gt;m&lt;/i&gt;) of components together with an &lt;i&gt;abstract&lt;/i&gt; component representing any number of other (possibly featured) components. The approach is applied to two systems with communication which is peer to peer and client server. We outline a proof of correctness in both cases. The techniques developed here are motivated by feature interaction analysis, but they are also applicable to reasoning about networks of other types of components with suitable notions of data abstraction

A Heuristic for Symmetry Reductions with Scalarsets

We present four versions of a new heuristic for coping with the problem of finding (canonical) representatives of symmetry equivalence classes (the so-called orbit problem), in symmetry techniques for model checking. The practical implementation of such techniques hinges on appropriate workarounds of this hard problem, which is equivalent to graph isomorphism. We implemented the four strategies on top of the Spin model checker, and compared their performance on several examples, with encouraging results