The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Wayne M Getz - One of the best experts on this subject based on the ideXlab platform.
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spores and soil from six sides interdisciplinarity and the environmental biology of Anthrax bacillus anthracis
Biological Reviews, 2018Co-Authors: Wayne M Getz, Colin J Carlson, Kyrre L Kausrud, Carrie A Cizauskas, Jason K Blackburn, Fausto Bustos Carrillo, Rita R ColwellAbstract:Author(s): Carlson, Colin J; Getz, Wayne M; Kausrud, Kyrre L; Cizauskas, Carrie A; Blackburn, Jason K; Bustos Carrillo, Fausto A; Colwell, Rita; Easterday, W Ryan; Ganz, Holly H; Kamath, Pauline L; Okstad, Ole A; Turner, Wendy C; Kolsto, Anne-Brit; Stenseth, Nils C | Abstract: Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of Anthrax (Bacillus anthracis). Anthrax is a zoonotic disease capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. Where Anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco-epidemiology of Anthrax, and the mysterious biology of Bacillus anthracis during its environmental stage, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long-term ecological research site in Namibia that has exemplified the complexities of the enzootic process of Anthrax over decades of surveillance. In Etosha, the role of scavengers and alternative routes (waterborne transmission and flies) has proved unimportant relative to the long-term persistence of Anthrax spores in soil and their infection of herbivore hosts. Carcass deposition facilitates green-ups of vegetation to attract herbivores, potentially facilitated by the role of Anthrax spores in the rhizosphere. The underlying seasonal pattern of vegetation, and herbivores' immune and behavioural responses to Anthrax risk, interact to produce regular 'Anthrax seasons' that appear to be a stable feature of the Etosha ecosystem. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how Anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways Anthrax might offer insights into the biology of other important pathogens. Bacillus anthracis, and the more recently emerged Bacillus cereus biovar anthracis, share key features with other environmentally transmitted pathogens, including several zoonoses and panzootics of special interest for global health and conservation efforts. Understanding the dynamics of Anthrax, and developing interdisciplinary research programs that explore environmental persistence, is a critical step forward for understanding these emerging threats.
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spores and soil from six sides interdisciplinarity and the environmental biology of Anthrax bacillus anthracis
bioRxiv, 2017Co-Authors: Colin J Carlson, Wayne M Getz, Kyrre L Kausrud, Carrie A Cizauskas, Jason K Blackburn, Fausto Bustos Carrillo, Rita R Colwell, Ryan W Easterday, Holly H Ganz, Pauline L KamathAbstract:Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of Anthrax (Bacillus anthracis). Anthrax is a zoonosis that is capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. In sites where Anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco-epidemiology of Anthrax, and the mysterious biology of Bacillus anthracis during its persistence in the environment, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long-term ecological research site in Namibia that has exemplified the complexities of Anthrax9s enzootic process over decades of surveillance. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how Anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways Anthrax might offer insights into the biology of other important pathogens.
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soil ingestion nutrition and the seasonality of Anthrax in herbivores of etosha national park
Ecosphere, 2013Co-Authors: Wendy C Turner, Peace Imologhome, Zepee Havarua, G P Kaaya, John K E Mfune, Irvin D T Mpofu, Wayne M GetzAbstract:Anthrax, caused by the bacterium Bacillus anthracis, is a seasonally occurring infectious disease affecting primarily herbivorous wildlife and livestock. The seasonality of Anthrax outbreaks varies among locations, making it difficult to develop a single consistent ecological description of this disease. Over 44 years of mortality surveillance, most Anthrax cases in Etosha National Park, Namibia are observed in the wet season, although elephants have an Anthrax mortality peak in the dry season. Focusing on three host species (plains zebra, Equus quagga; African elephant, Loxodonta africana; and springbok, Antidorcas marsupialis) occupying the endemic Anthrax area of Etosha National Park, Namibia, we tested two commonly posited causes of Anthrax seasonality in herbivores: increased pathogen exposure due to greater soil contact, and increased host susceptibility due to seasonal nutritional stress. These hypotheses were assessed using fecal sampling and measurement of the percentage of fecal silicates as an ...
Stephen H Leppla - One of the best experts on this subject based on the ideXlab platform.
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Anthrax lethal and edema toxins in Anthrax pathogenesis
Trends in Microbiology, 2014Co-Authors: Mahtab Moayeri, Stephen H LepplaAbstract:The pathophysiological effects resulting from many bacterial diseases are caused by exotoxins released by the bacteria. Bacillus anthracis, a spore-forming bacterium, is such a pathogen, causing Anthrax through a combination of bacterial infection and toxemia. B. anthracis causes natural infection in humans and animals and has been a top bioterrorism concern since the 2001 Anthrax attacks in the USA. The exotoxins secreted by B. anthracis use capillary morphogenesis protein 2 (CMG2) as the major toxin receptor and play essential roles in pathogenesis during the entire course of the disease. This review focuses on the activities of Anthrax toxins and their roles in initial and late stages of Anthrax infection.
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cellular and systemic effects of Anthrax lethal toxin and edema toxin
Molecular Aspects of Medicine, 2009Co-Authors: Mahtab Moayeri, Stephen H LepplaAbstract:Anthrax lethal toxin (LT) and edema toxin (ET) are the major virulence factors of Anthrax and can replicate the lethality and symptoms associated with the disease. This review provides an overview of our current understanding of Anthrax toxin effects in animal models and the cytotoxicity (necrosis and apoptosis) induced by LT in different cells. A brief reexamination of early historic findings on toxin in vivo effects in the context of our current knowledge is also presented.
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capillary morphogenesis protein 2 is the major receptor mediating lethality of Anthrax toxin in vivo
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Devorah Crown, Sharmina Millerrandolph, Mahtab Moayeri, Hailun Wang, Haijing Hu, T D Morley, Stephen H LepplaAbstract:Anthrax toxin, a major virulence factor of Bacillus anthracis, gains entry into target cells by binding to either of 2 von Willebrand factor A domain-containing proteins, tumor endothelium marker-8 (TEM8) and capillary morphogenesis protein-2 (CMG2). The wide tissue expression of TEM8 and CMG2 suggest that both receptors could play a role in Anthrax pathogenesis. To explore the roles of TEM8 and CMG2 in normal physiology, as well as in Anthrax pathogenesis, we generated TEM8- and CMG2-null mice and TEM8/CMG2 double-null mice by deleting TEM8 and CMG2 transmembrane domains. TEM8 and CMG2 were found to be dispensable for mouse development and life, but both are essential in female reproduction in mice. We found that the lethality of Anthrax toxin for mice is mostly mediated by CMG2 and that TEM8 plays only a minor role. This is likely because Anthrax toxin has approximately 11-fold higher affinity for CMG2 than for TEM8. Finally, the CMG2-null mice are also shown to be highly resistant to B. anthracis spore infection, attesting to the importance of both Anthrax toxin and CMG2 in Anthrax infections.
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Anthrax toxin triggers endocytosis of its receptor via a lipid raft mediated clathrin dependent process
Journal of Cell Biology, 2003Co-Authors: Laurence Abrami, Stephen H Leppla, Pierre Cosson, Gisou F Van Der GootAbstract:The protective antigen (PA) of the Anthrax toxin binds to a cell surface receptor and thereby allows lethal factor (LF) to be taken up and exert its toxic effect in the cytoplasm. Here, we report that clustering of the Anthrax toxin receptor (ATR) with heptameric PA or with an antibody sandwich causes its association to specialized cholesterol and glycosphingolipid-rich microdomains of the plasma membrane (lipid rafts). We find that although endocytosis of ATR is slow, clustering it into rafts either via PA heptamerization or using an antibody sandwich is necessary and sufficient to trigger efficient internalization and allow delivery of LF to the cytoplasm. Importantly, altering raft integrity using drugs prevented LF delivery and cleavage of cytosolic MAPK kinases, suggesting that lipid rafts could be therapeutic targets for drugs against Anthrax. Moreover, we show that internalization of PA is dynamin and Eps15 dependent, indicating that the clathrin-dependent pathway is the major route of Anthrax toxin entry into the cell. The present work illustrates that although the physiological role of the ATR is unknown, its trafficking properties, i.e., slow endocytosis as a monomer and rapid clathrin-mediated uptake on clustering, make it an ideal Anthrax toxin receptor.
Rita R Colwell - One of the best experts on this subject based on the ideXlab platform.
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spores and soil from six sides interdisciplinarity and the environmental biology of Anthrax bacillus anthracis
Biological Reviews, 2018Co-Authors: Wayne M Getz, Colin J Carlson, Kyrre L Kausrud, Carrie A Cizauskas, Jason K Blackburn, Fausto Bustos Carrillo, Rita R ColwellAbstract:Author(s): Carlson, Colin J; Getz, Wayne M; Kausrud, Kyrre L; Cizauskas, Carrie A; Blackburn, Jason K; Bustos Carrillo, Fausto A; Colwell, Rita; Easterday, W Ryan; Ganz, Holly H; Kamath, Pauline L; Okstad, Ole A; Turner, Wendy C; Kolsto, Anne-Brit; Stenseth, Nils C | Abstract: Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of Anthrax (Bacillus anthracis). Anthrax is a zoonotic disease capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. Where Anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco-epidemiology of Anthrax, and the mysterious biology of Bacillus anthracis during its environmental stage, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long-term ecological research site in Namibia that has exemplified the complexities of the enzootic process of Anthrax over decades of surveillance. In Etosha, the role of scavengers and alternative routes (waterborne transmission and flies) has proved unimportant relative to the long-term persistence of Anthrax spores in soil and their infection of herbivore hosts. Carcass deposition facilitates green-ups of vegetation to attract herbivores, potentially facilitated by the role of Anthrax spores in the rhizosphere. The underlying seasonal pattern of vegetation, and herbivores' immune and behavioural responses to Anthrax risk, interact to produce regular 'Anthrax seasons' that appear to be a stable feature of the Etosha ecosystem. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how Anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways Anthrax might offer insights into the biology of other important pathogens. Bacillus anthracis, and the more recently emerged Bacillus cereus biovar anthracis, share key features with other environmentally transmitted pathogens, including several zoonoses and panzootics of special interest for global health and conservation efforts. Understanding the dynamics of Anthrax, and developing interdisciplinary research programs that explore environmental persistence, is a critical step forward for understanding these emerging threats.
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spores and soil from six sides interdisciplinarity and the environmental biology of Anthrax bacillus anthracis
bioRxiv, 2017Co-Authors: Colin J Carlson, Wayne M Getz, Kyrre L Kausrud, Carrie A Cizauskas, Jason K Blackburn, Fausto Bustos Carrillo, Rita R Colwell, Ryan W Easterday, Holly H Ganz, Pauline L KamathAbstract:Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of Anthrax (Bacillus anthracis). Anthrax is a zoonosis that is capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. In sites where Anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco-epidemiology of Anthrax, and the mysterious biology of Bacillus anthracis during its persistence in the environment, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long-term ecological research site in Namibia that has exemplified the complexities of Anthrax9s enzootic process over decades of surveillance. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how Anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways Anthrax might offer insights into the biology of other important pathogens.
Mahtab Moayeri - One of the best experts on this subject based on the ideXlab platform.
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Anthrax lethal and edema toxins in Anthrax pathogenesis
Trends in Microbiology, 2014Co-Authors: Mahtab Moayeri, Stephen H LepplaAbstract:The pathophysiological effects resulting from many bacterial diseases are caused by exotoxins released by the bacteria. Bacillus anthracis, a spore-forming bacterium, is such a pathogen, causing Anthrax through a combination of bacterial infection and toxemia. B. anthracis causes natural infection in humans and animals and has been a top bioterrorism concern since the 2001 Anthrax attacks in the USA. The exotoxins secreted by B. anthracis use capillary morphogenesis protein 2 (CMG2) as the major toxin receptor and play essential roles in pathogenesis during the entire course of the disease. This review focuses on the activities of Anthrax toxins and their roles in initial and late stages of Anthrax infection.
-
cellular and systemic effects of Anthrax lethal toxin and edema toxin
Molecular Aspects of Medicine, 2009Co-Authors: Mahtab Moayeri, Stephen H LepplaAbstract:Anthrax lethal toxin (LT) and edema toxin (ET) are the major virulence factors of Anthrax and can replicate the lethality and symptoms associated with the disease. This review provides an overview of our current understanding of Anthrax toxin effects in animal models and the cytotoxicity (necrosis and apoptosis) induced by LT in different cells. A brief reexamination of early historic findings on toxin in vivo effects in the context of our current knowledge is also presented.
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capillary morphogenesis protein 2 is the major receptor mediating lethality of Anthrax toxin in vivo
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Devorah Crown, Sharmina Millerrandolph, Mahtab Moayeri, Hailun Wang, Haijing Hu, T D Morley, Stephen H LepplaAbstract:Anthrax toxin, a major virulence factor of Bacillus anthracis, gains entry into target cells by binding to either of 2 von Willebrand factor A domain-containing proteins, tumor endothelium marker-8 (TEM8) and capillary morphogenesis protein-2 (CMG2). The wide tissue expression of TEM8 and CMG2 suggest that both receptors could play a role in Anthrax pathogenesis. To explore the roles of TEM8 and CMG2 in normal physiology, as well as in Anthrax pathogenesis, we generated TEM8- and CMG2-null mice and TEM8/CMG2 double-null mice by deleting TEM8 and CMG2 transmembrane domains. TEM8 and CMG2 were found to be dispensable for mouse development and life, but both are essential in female reproduction in mice. We found that the lethality of Anthrax toxin for mice is mostly mediated by CMG2 and that TEM8 plays only a minor role. This is likely because Anthrax toxin has approximately 11-fold higher affinity for CMG2 than for TEM8. Finally, the CMG2-null mice are also shown to be highly resistant to B. anthracis spore infection, attesting to the importance of both Anthrax toxin and CMG2 in Anthrax infections.
Colin J Carlson - One of the best experts on this subject based on the ideXlab platform.
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spores and soil from six sides interdisciplinarity and the environmental biology of Anthrax bacillus anthracis
Biological Reviews, 2018Co-Authors: Wayne M Getz, Colin J Carlson, Kyrre L Kausrud, Carrie A Cizauskas, Jason K Blackburn, Fausto Bustos Carrillo, Rita R ColwellAbstract:Author(s): Carlson, Colin J; Getz, Wayne M; Kausrud, Kyrre L; Cizauskas, Carrie A; Blackburn, Jason K; Bustos Carrillo, Fausto A; Colwell, Rita; Easterday, W Ryan; Ganz, Holly H; Kamath, Pauline L; Okstad, Ole A; Turner, Wendy C; Kolsto, Anne-Brit; Stenseth, Nils C | Abstract: Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of Anthrax (Bacillus anthracis). Anthrax is a zoonotic disease capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. Where Anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco-epidemiology of Anthrax, and the mysterious biology of Bacillus anthracis during its environmental stage, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long-term ecological research site in Namibia that has exemplified the complexities of the enzootic process of Anthrax over decades of surveillance. In Etosha, the role of scavengers and alternative routes (waterborne transmission and flies) has proved unimportant relative to the long-term persistence of Anthrax spores in soil and their infection of herbivore hosts. Carcass deposition facilitates green-ups of vegetation to attract herbivores, potentially facilitated by the role of Anthrax spores in the rhizosphere. The underlying seasonal pattern of vegetation, and herbivores' immune and behavioural responses to Anthrax risk, interact to produce regular 'Anthrax seasons' that appear to be a stable feature of the Etosha ecosystem. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how Anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways Anthrax might offer insights into the biology of other important pathogens. Bacillus anthracis, and the more recently emerged Bacillus cereus biovar anthracis, share key features with other environmentally transmitted pathogens, including several zoonoses and panzootics of special interest for global health and conservation efforts. Understanding the dynamics of Anthrax, and developing interdisciplinary research programs that explore environmental persistence, is a critical step forward for understanding these emerging threats.
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spores and soil from six sides interdisciplinarity and the environmental biology of Anthrax bacillus anthracis
bioRxiv, 2017Co-Authors: Colin J Carlson, Wayne M Getz, Kyrre L Kausrud, Carrie A Cizauskas, Jason K Blackburn, Fausto Bustos Carrillo, Rita R Colwell, Ryan W Easterday, Holly H Ganz, Pauline L KamathAbstract:Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of Anthrax (Bacillus anthracis). Anthrax is a zoonosis that is capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. In sites where Anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco-epidemiology of Anthrax, and the mysterious biology of Bacillus anthracis during its persistence in the environment, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long-term ecological research site in Namibia that has exemplified the complexities of Anthrax9s enzootic process over decades of surveillance. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how Anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways Anthrax might offer insights into the biology of other important pathogens.