245 research outputs found

    The Virulence Factor Ycho Has A Pleiotropic Action In An Avian Pathogenic Escherichia Coli (apec) Strain

    Get PDF
    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Avian pathogenic Escherichia coli strains cause extraintestinal diseases in birds, leading to substantial economic losses to the poultry industry worldwide. Bacteria that invade cells can overcome the host humoral immune response, resulting in a higher pathogenicity potential. Invasins are members of a large family of outer membrane proteins that allow pathogen invasion into host cells by interacting with specific receptors on the cell surface. Results: An in silico analysis of the genome of a septicemic APEC strain (SEPT362) demonstrated the presence of a putative invasin homologous to the ychO gene from E. coli str. K-12 substr. MG1655. In vitro and in vivo assays comparing a mutant strain carrying a null mutation of this gene, a complemented strain, and its counterpart wildtype strain showed that ychO plays a role in the pathogenicity of APEC strain SEPT362. In vitro assays demonstrated that the mutant strain exhibited significant decreases in bacterial adhesiveness and invasiveness in chicken cells and biofilm formation. In vivo assay indicated a decrease in pathogenicity of the mutant strain. Moreover, transcriptome analysis demonstrated that the ychO deletion affected the expression of 426 genes. Among the altered genes, 93.66 % were downregulated in the mutant, including membrane proteins and metabolism genes. Conclusion: The results led us to propose that gene ychO contributes to the pathogenicity of APEC strain SEPT362 influencing, in a pleiotropic manner, many biological characteristics, such as adhesion and invasion of in vitro cultured cells, biofilm formation and motility, which could be due to the possible membrane location of this protein. All of these results suggest that the absence of gene ychO would influence the virulence of the APEC strain herein studied.16Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [2012/04391-1, 2012/09655-7]CNPqFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Branding in a Hyperconnected World: Refocusing Theories and Rethinking Boundaries

    Get PDF
    Technological advances have resulted in a hyperconnected world, requiring a reassessment of branding research from the perspectives of firms, consumers, and society. Brands are shifting away from single ownership to shared ownership, as heightened access to information and people is allowing more stakeholders to cocreate brand meanings and experiences alongside traditional brand owners and managers. Moreover, hyperconnectivity has allowed existing brands to expand their geographic reach and societal roles, while new types of branded entities (ideas, people, places, and organizational brands) are further stretching the branding space. To help establish a new branding paradigm that accounts for these changes, the authors address the following questions: (1) What are the roles and functions of brands?, (2) How is brand value (co)created?, and (3) How should brands be managed? Throughout the article, the authors also identify future research issues that require scholarly attention, with the aim of aligning branding theory and practice with the realities of a hyperconnected world

    Molecular footprints of the Holocene retreat of dwarf birch in Britain

    Get PDF
    © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

    Concomitant medication use and its implications on the hazard pattern in pharmacoepidemiological studies: example of antidepressants, benzodiazepines and fracture risk

    Get PDF
    Background: Antidepressants and benzodiazepines are often co-prescribed and both associated with an increased fracture risk, albeit with distinctive hazard patterns. Timing of initiation of one with respect to the other and duration of use may influence the combined fracture hazard. The objective of our study was to describe patterns of concomitant use of benzodiazepine and antidepressants in terms of timing of initiation and duration and to illustrate the potential impact of various scenarios of timing of co-use on hip fracture hazard. Methods: Patients initiating antidepressant therapy (2002-2009) were identified from the Netherlands Primary Care Research Database. Concomitant benzodiazepine use was assessed according to the start time of benzodiazepine with respect to antidepressant therapy start. Duration of concomitant use was estimated relative to the length of antidepressant treatment episode.  Results: Among 16,087 incident antidepressant users, 39.0% used benzodiazepines concomitantly during their first antidepressant treatment episode. The time of initiation of benzodiazepine use was variable (64.4% starting before, 13.7% simultaneous and 21.9% after antidepressants). Duration of concomitant use in the three groups varied.  Conclusions: Co-prescribed medications with a common adverse event, may not only require accounting for concomitant use, but also the timing of start and duration of use as the overall hazard may vary accordingly

    Validation of a Novel Method to Assess the Clinical Quality of Information in Pregnancy-Related Pharmacovigilance Case Reports: A ConcePTION Project.

    Get PDF
    To assess the causal relationship between a medicinal product and a reported event, relevant information needs to be present. Information elements for assessing cases of exposure to medicinal products during pregnancy were predefined and used in a new tool to assess the quality of information. However, the extent in which the presence or absence of these predefined information elements is associated with the overall clinical quality of these cases, as evaluated by pharmacovigilance experts, remains uncertain. We aimed to validate a novel method to assess the clinical quality of information in real-world pregnancy pharmacovigilance case reports. The clinical quality of case reports regarding medicinal product exposure and pregnancy-related outcomes was appraised from spontaneous reports, literature, Teratology Information Services (UK and Switzerland), The Dutch Pregnancy Drug Register, the Gilenya pregnancy registry and the Enhanced PV programme of Novartis. Assessment was done by means of the novel standardised tool based on the presence and relevance of information, and by expert judgement. The novel tool was validated compared to the expert assessment as the gold standard expressed as the area under the receiver operating characteristic curves, after which the sensitivity and specificity were calculated using cross-tabulations. Inter-rater variability was determined by means of weighted Cohen's kappa. One hundred and eighty-six case reports were included. The clinical quality score as assessed by the novel method was divided into three categories with cut-off values of 45% (poor to intermediate) and 65% (intermediate to excellent). Sensitivity was 0.93 and 0.96 for poor to intermediate and intermediate to excellent, respectively. Specificity was respectively 0.52 and 0.73. Inter-rater variability was 0.65 (95% confidence interval 0.53-0.78) for the newly developed approach, and 0.40 (95% confidence interval 0.28-0.52) for the gold standard assessment. The tool described in this study using the presence and relevance of elements of information is the first designed, validated and standardised method for the assessment of the quality of information of case reports in pregnancy pharmacovigilance data. This method confers less inter-rater variability compared with a quality assessment by experts of pregnancy-related pharmacovigilance data

    Genotyping of Brazilian Giardia duodenalis human axenic isolates

    Full text link
    Giardia duodenalis is a complex species that comprises at least seven distinct genetic groups (A to G), but only genotypes A and B are known to infect humans and a wide variety of other mammals. Regardless of biological, biochemical and antigenic analysis, several isolates maintained in vitro were not genetically typed yet. So, in the present study, five Brazilian axenic isolates obtained from asymptomatic and symptomatic patients were typed in order to determine the major genetic groups to which the isolates belonged. DNA was extracted from axenic trophozoites, fragments of glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes were amplified by PCR and the isolate genotyping was carried out using restriction fragment length polymorphism (RFLP) and DNA sequencing for both genes. The results revealed that all isolates were assigned to genotype A at both analyzed loci. Indeed, DNA sequence analysis classified the four isolates obtained from asymptomatic individuals into subtype AII, while the isolate obtained from the symptomatic patient was typed as subtype AI. Despite of the limited number of isolates assessed, the findings presented herein provide interesting insights on the occurrence of Giardia genotypes in Brazil and hold the perspective for future molecular and epidemiological investigations

    Hybridization and hybrid speciation under global change

    Get PDF
    An unintended consequence of global change is an increase in opportunities for hybridization among previously isolated lineages. Here we illustrate how global change can facilitate the breakdown of reproductive barriers and the formation of hybrids, drawing on the flora of the British Isles for insight. Although global change may ameliorate some of the barriers preventing hybrid establishment, for example by providing new ecological niches for hybrids, it will have limited effects on environment-independent post-zygotic barriers. For example, genic incompatibilities and differences in chromosome numbers and structure within hybrid genomes are unlikely to be affected by global change. We thus speculate that global change will have a larger effect on eroding pre-zygotic barriers (eco-geographical isolation and phenology) than post-zygotic barriers, shifting the relative importance of these two classes of reproductive barriers from what is usually seen in naturally produced hybrids where pre-zygotic barriers are the largest contributors to reproductive isolation. Although the long-term fate of neo-hybrids is still to be determined, the massive impact of global change on the dynamics and distribution of biodiversity generates an unprecedented opportunity to study large numbers of unpredicted, and often replicated, hybridization ‘experiments’, allowing us to peer into the birth and death of evolutionary lineages

    Evaluation of the integration level of quality and environmental management systems in a tire manufacturer

    Get PDF
    Purpose: This article aims to evaluate the integration level of a quality management system (QMS) and an environmental management system (EMS) in a tire manufacturer and propose a guide to evaluate the integration of these systems in companies. Design/methodology/approach: The methodological strategies used in this research were literature review; and case study, with interviews to verify professionals' perception about benefits from integration. Data from interviews were analyzed through Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Findings: The results showed that the studied company has a simple level of integration, observing only some low intensity benefits. Thus, it was recommended that the company partially integrate its management systems (MSs) before evolving into something more complex. The literature and the findings of case study were used as basis for proposing a guide to evaluate MS integration. Originality/value: Lessons learned throughout the study and the suggested guide can support other companies to assess the integration level of their QMS and EMS. Thus, the findings presented here can be useful for researchers and managers

    On the use of parataxonomy in biodiversity monitoring: a case study on wild flora

    Get PDF
    International audienceMonitoring programs that assess species-richness and turnover are now regarded as essential to document biodiversity loss worldwide. Implementation of such programs is impeded by a general decrease in the number of skilled naturalists. Here we studied how morphotypes, instead of species, might be used by unskilled participants (referred to as “volunteers”) to survey common plant communities. Our main questions were: (1) Can morphotypes be used as a robust estimator of species-richness (alpha-diversity) and assemblage turnover (Beta-diversity)? and (2) What is the robustness (reproducibility and repeatability) of such methods? Double inventories were performed on 150 plots in arable Weld margins, one by a non-expert using morphotypes, the other by a taxonomist using species. To test the robustness of morphotype identiWcation among participants, 20 additional plots were surveyed by eight volunteers using the same protocol. We showed that (1) the number of morphotypes identiWed by unskilled volunteers in a plot was always strongly correlated with species-richness. (2) Morphotypes were sensitive to diVerences among habitats but were less accurate than species to detect these diVerences. (3) Morphotype identiWcation varied signiWcantly within and between volunteers. Due to this lack of repeatability and reproducibility, parataxonomy cannot be considered a good surrogate for taxonomy. Nevertheless, assuming that morphotypes are identiWed with standardized methods, and that results are used only to evaluate gross species-richness but not species turnover, parataxonomy might be a valuable tool for rapid biodiversity assessment of common wild flora

    The coral core microbiome identifies rare bacterial taxa as ubiquitous endosymbionts

    Get PDF
    © 2015 International Society for Microbial Ecology All rights reserved. Despite being one of the simplest metazoans, corals harbor some of the most highly diverse and abundant microbial communities. Differentiating core, symbiotic bacteria from this diverse hostassociated consortium is essential for characterizing the functional contributions of bacteria but has not been possible yet. Here we characterize the coral core microbiome and demonstrate clear phylogenetic and functional divisions between the micro-scale, niche habitats within the coral host. In doing so, we discover seven distinct bacterial phylotypes that are universal to the core microbiome of coral species, separated by thousands of kilometres of oceans. The two most abundant phylotypes are co-localized specifically with the corals' endosymbiotic algae and symbiont-containing host cells. These bacterial symbioses likely facilitate the success of the dinoflagellate endosymbiosis with corals in diverse environmental regimes
    corecore