58 research outputs found

    Predatory Bacteria: A Potential Ally against Multidrug-Resistant Gram-Negative Pathogens

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    Multidrug-resistant (MDR) Gram-negative bacteria have emerged as a serious threat to human and animal health. Bdellovibrio spp. and Micavibrio spp. are Gram-negative bacteria that prey on other Gram-negative bacteria. In this study, the ability of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to prey on MDR Gram-negative clinical strains was examined. Although the potential use of predatory bacteria to attack MDR pathogens has been suggested, the data supporting these claims is lacking. By conducting predation experiments we have established that predatory bacteria have the capacity to attack clinical strains of a variety of ß-lactamase-producing, MDR Gram-negative bacteria. Our observations indicate that predatory bacteria maintained their ability to prey on MDR bacteria regardless of their antimicrobial resistance, hence, might be used as therapeutic agents where other antimicrobial drugs fail. © 2013 Kadouri et al

    Resilience Management for Healthy Cities in a Changing Climate

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    Cities are experiencing multiple impacts from global environmental change, and the degree to which they will need to cope with and adapt to these challenges will continue to increase. We argue that a ‘complex systems and resilience management’ view may significantly help guide future urban development through innovative integration of, for example, grey, blue and green infrastructure embedded in flexible institutions (both formal and informal) for multi-functionality and improved health. For instance, the urban heat island effect will further increase city-centre temperatures during projected more frequent and intense heat waves. The elderly and people with chronic cardiovascular and respiratory diseases are particularly vulnerable to heat. Integrating vegetation and especially trees in the urban infrastructure helps reduce temperatures by shading and evapotranspiration. Great complexity and uncertainty of urban social-ecological systems are behind this heatwave-health nexus, and they need to be addressed in a more comprehensive manner. We argue that a systems perspective can lead to innovative designs of new urban infrastructure and the redesign of existing structures. Particularly to promoting the integration of grey, green and blue infrastructure in urban planning through institutional innovation and structural reorganization of knowledge-action systems may significantly enhance prospects for improved urban health and greater resilience under various scenarios of climate change.info:eu-repo/semantics/publishedVersio

    An Eye to a Kill: Using Predatory Bacteria to Control Gram-Negative Pathogens Associated with Ocular Infections

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    Ocular infections are a leading cause of vision loss. It has been previously suggested that predatory prokaryotes might be used as live antibiotics to control infections. In this study, Pseudomonas aeruginosa and Serratia marcescens ocular isolates were exposed to the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus. All tested S. marcescens isolates were susceptible to predation by B. bacteriovorus strains 109J and HD100. Seven of the 10 P. aeruginosa isolates were susceptible to predation by B. bacteriovorus 109J with 80% being attacked by M. aeruginosavorus. All of the 19 tested isolates were found to be sensitive to at least one predator. To further investigate the effect of the predators on eukaryotic cells, human corneal-limbal epithelial (HCLE) cells were exposed to high concentrations of the predators. Cytotoxicity assays demonstrated that predatory bacteria do not damage ocular surface cells in vitro whereas the P. aeruginosa used as a positive control was highly toxic. Furthermore, no increase in the production of the proinflammatory cytokines IL-8 and TNF-alpha was measured in HCLE cells after exposure to the predators. Finally, injection of high concentration of predatory bacteria into the hemocoel of Galleria mellonella, an established model system used to study microbial pathogenesis, did not result in any measurable negative effect to the host. Our results suggest that predatory bacteria could be considered in the near future as a safe topical bio-control agent to treat ocular infections. © 2013 Shanks et al

    Collective action for smallholder market access

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    Collective action for smallholder market access: evidence and implications for Africa

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    It is widely acknowledged that the involvement of small farmers into markets can contribute to higher productivity and income growth, which in turn can enhance food security, poverty reduction efforts, and overall economic growth. In Africa, as in other parts of the developing world, agricultural production systems and their participants face significant challenges as a result of changing economic, environmental, and sociopolitical context. New dynamics in the global agricultural economy, such as the growth of supermarkets, are providing smallholders with both the new opportunities and new constraints to participate in and benefit from market exchanges. Collective action in the form of producer groups can enable African smallholders to take advantage of the new value chains and deal with existing market imperfections. However, certain conditions must be in place to create and sustain incentives for farmers to organize around marketing. Experiences from collective action in natural resource management (NRM) have shown that the types of markets and products, characteristics of user groups, institutional arrangements, and external environment need to be considered in order to determine the effectiveness and sustainability of collective marketing for smallholders. This paper applies the lessons from collective action in NRM to marketing, using existing case studies of producer groups in Africa, and offers policy recommendations on the factors that contribute to the success of collective marketing efforts

    Collective action and property rights for poverty reduction: insights from Africa and Asia

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    To improve their well-being, the poor in developing countries have used both collective action through formal and informal groups and property rights to natural resources. Collective Action and Property Rights for Poverty Reduction: Insights from Africa and Asia examines how these two types of institutions, separately and together, influence quality of life and how they can be strengthened to improve the livelihoods of the rural poor. The product of a global research study by the Systemwide Program on Collective Action and Property Rights (CAPRi) of the Consultative Group on International Agricultural Research, this book draws on case studies from East Africa and South and Southeast Asia to investigate how collective action and property rights have contributed to poverty reduction. The book extends the analysis of these institutions beyond their frequently studied role in natural resource management by also examining how they can reduce vulnerability to different types of shocks. Essays in the volume identify opportunities and risks present in the institutions of collective action and property rights. For example, property rights to natural resources can offer a variety of advantages, providing individuals and groups not only with benefits and incomes but also with assets that can counter the negative effects of shocks such as drought, and can make collective action easier. The authors also demonstrate that collective action has the potential to reduce poverty if it includes more vulnerable groups such as women, ethnic minorities, and the very poor. Preventing exclusion of these often-marginalized groups and guaranteeing genuinely inclusive collective action might require special rules and policies. Another danger to the poor is the capture of property rights by elites, which can be the result of privatization and decentralization policies; case studies and analysis identify actions to prevent such elite capture
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