117 research outputs found

    A Deoxyribonucleic Acid Decoy Trapping DUX4 for the Treatment of Facioscapulohumeral Muscular Dystrophy

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    Facioscapulohumeral dystrophy (FSHD) is characterized by a loss of repressive epigenetic marks leading to the aberrant expression of the DUX4 transcription factor. In muscle, DUX4 acts as a poison protein though the induction of multiple downstream genes. So far, there is no therapeutic solution for FSHD. Because DUX4 is a transcription factor, we developed an original therapeutic approach, based on a DNA decoy trapping the DUX4 protein, preventing its binding to genomic DNA and thereby blocking the aberrant activation of DUX4’s transcriptional network. In vitro, transfection of a DUX4 decoy into FSHD myotubes reduced the expression of the DUX4 network genes. In vivo, both double-stand DNA DUX4 decoys and adeno-associated viruses (AAVs) carrying DUX4 binding sites reduced transcriptional activation of genes downstream of DUX4 in a DUX4-expressing mouse model. Our study demonstrates, both in vitro and in vivo, the feasibility of the decoy strategy and opens new avenues of research

    Seasonal and Regional Dynamics of M. ulcerans Transmission in Environmental Context: Deciphering the Role of Water Bugs as Hosts and Vectors

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    Buruli ulcer, caused by Mycobacterium ulcerans, is a devastating skin disease. Most cases of Buruli ulcer occur in poor rural communities. As a result, treatment is frequently sought too late and about 25% of those infected—particularly children—become permanently disabled. Outbreaks of Buruli ulcer have always been associated with swampy areas. However, the route(s) of bacillus transmission is (are) still unclear. This Mycobacterium species resides in water where it colonizes many ecological niches such as aquatic plants, herbivorous animals and predatory/carnivorous insects. For several years the role of water bugs as hosts and vectors of M. ulcerans was suspected and was demonstrated under laboratory conditions. The aim of this work was to further assess the role of water bugs as hosts and vectors of M. ulcerans in environmental context. This work identifies several water bug families as hosts of M. ulcerans in Buruli ulcer endemic area. The detection of bacilli in saliva of human biting insects provides further evidence for their role in M. ulcerans transmission. Interestingly, three of these insects are good flyers, and as such could participate in M. ulcerans dissemination

    Los valores y el compromiso laboral en el empleo público

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    El presente estudio tiene como finalidad analizar el perfil axiológico de empleados públicos en relación con los niveles de compromiso laboral que presenta el sector. Se trabajó con un muestreo intencional conformado por 147 empleados de un organismo estatal de Mendoza, Argentina. La metodología utilizada es cuantitativa. En este artículo, se muestran los datos obtenidos a partir de la aplicación del Cuestionario de Valores en el Trabajo EVAT 30 y los indicadores de compromiso laboral medidos según el UWES. Los resultados indican asociaciones entre ambos instrumentos, lo que sugiere la importancia de recuperar la centralidad de los valores personales y organizacionales como un modo de incentivar la motivación y la dedicación al trabajo, en pro de la construcción de organizaciones saludables.This paper discusses the axiological profile of public employees in relation with the levels of engagement existing in the sector. A purposive sampling of 147 employees from a government agency in Mendoza, Argentina was used; the methodology applied, quantitative. The article includes data gathered through the EVAT 30 Questionnaire on Values at Work and engagement indicators measured by the Utrecht Work Engagement Scale–UWES. The results show a connection between both instruments, which, in turn, signals the importance of recovering the central role that both personal and organizational values have, as an incentive to motivation and dedication to work, in order to create healthy organizations

    Mycobacterium ulcerans ecological dynamics and its association with freshwater ecosystems and aquatic communities : results from a 12-month environmental survey in Cameroon

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    Background: Mycobacterium ulcerans (MU) is the agent responsible for Buruli Ulcer (BU), an emerging skin disease with dramatic socioeconomic and health outcomes, especially in rural settings. BU emergence and distribution is linked to aquatic ecosystems in tropical and subtropical countries, especially to swampy and flooded areas. Aquatic animal organisms are likely to play a role either as host reservoirs or vectors of the bacilli. However, information on MU ecological dynamics, both in space and time, is dramatically lacking. As a result, the ecology of the disease agent, and consequently its mode of transmission, remains largely unknown, which jeopardizes public health attempts for its control. The objective of this study was to gain insight on MU environmental distribution and colonization of aquatic organisms through time. Methodology/Principal Findings: Longitudinal sampling of 32 communities of aquatic macro-invertebrates and vertebrates was conducted from different environments in two BU endemic regions in Cameroon during 12 months. As a result, 238,496 individuals were classified and MU presence was assessed by qPCR in 3,084 sample-pools containing these aquatic organisms. Our study showed a broad distribution of MU in all ecosystems and taxonomic groups, with important regional differences in its occurrence. Colonization dynamics fluctuated along the year, with the highest peaks in August and October. The large variations observed in the colonization dynamics of different taxonomic groups and aquatic ecosystems suggest that the trends shown here are the result of complex ecological processes that need further investigation. Conclusion/Perspectives: This is the largest field study on MU ecology to date, providing the first detailed description of its spatio-temporal dynamics in different aquatic ecosystems within BU endemic regions. We argue that coupling this data with fine-scale epidemiological data through statistical and mathematical models will provide a major step forward in the understanding of MU ecology and mode of transmission

    Landscape Diversity Related to Buruli Ulcer Disease in Côte d'Ivoire

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    Buruli ulcer (BU) is one of the most neglected but treatable tropical diseases. The causative organism, Mycobacterium ulcerans, is from the family of bacteria that causes tuberculosis and leprosy. This severe skin disease leads to long-term functional disability if not treated. BU has been reported in over 30 countries mainly with tropical and subtropical climates, but Côte d'Ivoire is one of the most affected countries. M. ulcerans is an environmental bacterium and its mode of transmission to humans is still unclear, such that the disease is often referred to as the “mysterious disease” or the “new leprosy”. Here, we explored the relationship between environmental and socioeconomic factors and BU cases on a nationwide scale. We found that irrigated rice field cultures areas, and, to a lesser extent, banana fields as well as areas in the vicinity of dams used for irrigation and aquaculture purposes, represent high risk zones for the human population to contract BU in Côte d'Ivoire. This work identifies high-risk areas for BU in Côte d'Ivoire and deserves to be extended to different countries. We need now to obtain a global vision and understanding of the route of transmission of M. ulcerans to humans in order to better implement control strategies

    Extra-human epidemiology of Acinetobacter baumannii in Lebanon

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    Presence of Acinetobacter baumannii outside hospitals is still a controversial issue. The objective of our study was to explore the extra hospital epidemiology of A. baumannii in Lebanon. From February 2012 to October 2013, a total of 73 water samples, 51 soil samples, 37 raw cow milk samples, 50 cow meat samples, 7 raw cheese samples and 379 animal samples were analysed by cultural methods for the presence of A. baumannii. Species identification was performed by rpoB gene sequencing. Antibiotic susceptibility was investigated and A. baumannii population was studied by two genotyping approaches: Multilocus Sequence Typing (MLST) and blaOXA-51 Sequence-Based Typing (blaOXA-51 SBT). A. baumannii was detected in 6.9% of water samples, 2.7% of milk samples, 8.0% of meat samples, 14.3% of cheese samples and 7.7% of animal samples. All isolates showed a susceptible phenotype against most of the antibiotics tested and lacked carbapenemase encoding genes except one that harboured a blaOXA-143 gene. MLST analysis revealed the presence of 36 sequence types (ST), among them 24 were novel ST(s), reported for the first time in this study. blaOXA-51 SBT showed the presence of 34 variants, among them 21 were novel and all isolated from animal origin. Finally, 30 isolates had new partial rpoB sequences and were considered as putative new Acinetobacter species. In conclusion, animals can be a potential reservoir for A. baumannii and the dissemination of new emerging carbapenemases. The role of novel identified animal clones in community-acquired infections should be investigated

    Ecology and Transmission of Buruli Ulcer Disease: A Systematic Review

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    Buruli ulcer is a neglected emerging disease that has recently been reported in some countries as the second most frequent mycobacterial disease in humans after tuberculosis. Cases have been reported from at least 32 countries in Africa (mainly west), Australia, Southeast Asia, China, Central and South America, and the Western Pacific. Large lesions often result in scarring, contractual deformities, amputations, and disabilities, and in Africa, most cases of the disease occur in children between the ages of 4–15 years. This environmental mycobacterium, Mycobacterium ulcerans, is found in communities associated with rivers, swamps, wetlands, and human-linked changes in the aquatic environment, particularly those created as a result of environmental disturbance such as deforestation, dam construction, and agriculture. Buruli ulcer disease is often referred to as the “mysterious disease” because the mode of transmission remains unclear, although several hypotheses have been proposed. The above review reveals that various routes of transmission may occur, varying amongst epidemiological setting and geographic region, and that there may be some role for living agents as reservoirs and as vectors of M. ulcerans, in particular aquatic insects, adult mosquitoes or other biting arthropods. We discuss traditional and non-traditional methods for indicting the roles of living agents as biologically significant reservoirs and/or vectors of pathogens, and suggest an intellectual framework for establishing criteria for transmission. The application of these criteria to the transmission of M. ulcerans presents a significant challenge

    Photodegradation of the Mycobacterium ulcerans Toxin, Mycolactones: Considerations for Handling and Storage

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    Background: Mycolactones are toxins secreted by M. ulcerans, the etiological agent of Buruli ulcer. These toxins, which are the main virulence factors of the bacilli, are responsible for skin lesions. Considering their specificity for M. ulcerans and their presence in skin lesions even at early stages, mycolactones are promising candidates for the development of a diagnostic tool for M. ulcerans infection. Stability of purified mycolactones towards light and heat has not yet been investigated, despite the importance of such parameters in the selection of strategies for a diagnosis tool development. In this context, the effects of UV, light and temperature on mycolactone stability and biological activity were studied. Methodology/Principal Findings: To investigate the effect of these physical parameters, mycolactones were exposed to different wavelengths in several solvents and temperatures. Structural changes and biological activity were monitored. Whilst high temperature had no effect on mycolactones, UV irradiation (UV-A, UV-B and UV-C) and sunlight exposure caused a considerable degradation, as revealed by LC-MS and NMR analysis, correlated with a loss of biological activity. Moreover, effect of UVs on mycolactone caused a photodegradation rather than a phototransformation due to the identification of degradation product. Conclusion/Significance: This study demonstrates the high sensitivity of mycolactones to UVs as such it defines instruction

    Risk of Buruli Ulcer and Detection of Mycobacterium ulcerans in Mosquitoes in Southeastern Australia

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    Buruli ulcer (BU) is a destructive skin condition caused by infection with the environmental bacterium, Mycobacterium ulcerans. BU has been reported in more than 30 countries in Africa, the Americas, Asia and the Western Pacific. How people become infected with M. ulcerans is not completely understood, but numerous studies have explored the role of biting insects. In 2007, it was discovered that M. ulcerans could be detected in association with mosquitoes trapped in one town in southeastern Australia during a large outbreak of BU. In the present study we investigated whether there was a relationship between the incidence of BU in humans in several towns and the likelihood of detecting M. ulcerans in mosquitoes trapped in those locations. We found a strong association between the proportion of M. ulcerans-positive mosquitoes and the incidence of human disease. The results of this study strengthen the hypothesis that mosquitoes are involved in the transmission of M. ulcerans in southeastern Australia. This has implications for the development of strategies to control and prevent BU
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