WorldWideScience

Sample records for natural fungal epidemic

  1. Epidemics after Natural Disasters

    Science.gov (United States)

    Gayer, Michelle; Connolly, Maire A.

    2007-01-01

    The relationship between natural disasters and communicable diseases is frequently misconstrued. The risk for outbreaks is often presumed to be very high in the chaos that follows natural disasters, a fear likely derived from a perceived association between dead bodies and epidemics. However, the risk factors for outbreaks after disasters are associated primarily with population displacement. The availability of safe water and sanitation facilities, the degree of crowding, the underlying health status of the population, and the availability of healthcare services all interact within the context of the local disease ecology to influence the risk for communicable diseases and death in the affected population. We outline the risk factors for outbreaks after a disaster, review the communicable diseases likely to be important, and establish priorities to address communicable diseases in disaster settings. PMID:17370508

  2. Epidemic as a natural process.

    Science.gov (United States)

    Koivu-Jolma, Mikko; Annila, Arto

    2018-05-01

    Mathematical epidemiology is a well-recognized discipline to model infectious diseases. It also provides guidance for public health officials to limit outbreaks. Nevertheless, epidemics take societies by surprise every now and then, for example, when the Ebola virus epidemic raged seemingly unrestrained in Western Africa. We provide insight to this capricious character of nature by describing the epidemic as a natural process, i.e., a phenomenon governed by thermodynamics. Our account, based on statistical mechanics of open systems, clarifies that it is impossible to predict accurately epidemic courses because everything depends on everything else. Nonetheless, the thermodynamic theory yields a comprehensive and analytical view of the epidemic. The tenet subsumes various processes in a scale-free manner from the molecular to the societal levels. The holistic view accentuates overarching procedures in arresting and eradicating epidemics. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Invasive fungal infections after natural disasters.

    Science.gov (United States)

    Benedict, Kaitlin; Park, Benjamin J

    2014-03-01

    The link between natural disasters and subsequent fungal infections in disaster-affected persons has been increasingly recognized. Fungal respiratory conditions associated with disasters include coccidioidomycosis, and fungi are among several organisms that can cause near-drowning pneumonia. Wound contamination with organic matter can lead to post-disaster skin and soft tissue fungal infections, notably mucormycosis. The role of climate change in the environmental growth, distribution, and dispersal mechanisms of pathogenic fungi is not fully understood; however, ongoing climate change could lead to increased disaster-associated fungal infections. Fungal infections are an often-overlooked clinical and public health issue, and increased awareness by health care providers, public health professionals, and community members regarding disaster-associated fungal infections is needed.

  4. Food system consequences of a fungal disease epidemic in a major crop.

    Science.gov (United States)

    Godfray, H Charles J; Mason-D'Croz, Daniel; Robinson, Sherman

    2016-12-05

    Fungal diseases are major threats to the most important crops upon which humanity depends. Were there to be a major epidemic that severely reduced yields, its effects would spread throughout the globalized food system. To explore these ramifications, we use a partial equilibrium economic model of the global food system (IMPACT) to study a hypothetical severe but short-lived epidemic that reduces rice yields in the countries affected by 80%. We modelled a succession of epidemic scenarios of increasing severity, starting with the disease in a single country in southeast Asia and ending with the pathogen present in most of eastern Asia. The epidemic and subsequent crop losses led to substantially increased global rice prices. However, as long as global commodity trade was unrestricted and able to respond fast enough, the effects on individual calorie consumption were, to a large part, mitigated. Some of the worse effects were projected to be experienced by poor net-rice importing countries in sub-Saharan Africa, which were not affected directly by the disease but suffered because of higher rice prices. We critique the assumptions of our models and explore political economic pressures to restrict trade at times of crisis. We finish by arguing for the importance of 'stress-testing' the resilience of the global food system to crop disease and other shocks.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Author(s).

  5. Fungal polyketide azaphilone pigments as future natural food colorants?

    DEFF Research Database (Denmark)

    Mapari, Sameer Shamsuddin; Thrane, Ulf; Meyer, Anne S.

    2010-01-01

    The recent approval of fungal carotenoids as food colorants by the European Union has strengthened the prospects for fungal cell factories for the production of polyketide pigments. Fungal production of colorants has the main advantage of making the manufacturer independent of the seasonal supply...... functionality and to expand the color palette of contemporary natural food colorants.......The recent approval of fungal carotenoids as food colorants by the European Union has strengthened the prospects for fungal cell factories for the production of polyketide pigments. Fungal production of colorants has the main advantage of making the manufacturer independent of the seasonal supply...... of raw materials, thus minimizing batch-to-batch variations. Here, we review the potential of polyketide pigments produced from chemotaxonomically selected non-toxigenic fungal strains (e.g. Penicillium and Epicoccum spp.) to serve as food colorants. We argue that the production of polyketide azaphilone...

  6. Mate Limitation in Fungal Plant Parasites Can Lead to Cyclic Epidemics in Perennial Host Populations.

    Science.gov (United States)

    Ravigné, Virginie; Lemesle, Valérie; Walter, Alicia; Mailleret, Ludovic; Hamelin, Frédéric M

    2017-03-01

    Fungal plant parasites represent a growing concern for biodiversity and food security. Most ascomycete species are capable of producing different types of infectious spores both asexually and sexually. Yet the contributions of both types of spores to epidemiological dynamics have still to been fully researched. Here we studied the effect of mate limitation in parasites which perform both sexual and asexual reproduction in the same host. Since mate limitation implies positive density dependence at low population density, we modeled the dynamics of such species with both density-dependent (sexual) and density-independent (asexual) transmission rates. A first simple SIR model incorporating these two types of transmission from the infected compartment, suggested that combining sexual and asexual spore production can generate persistently cyclic epidemics in a significant part of the parameter space. It was then confirmed that cyclic persistence could occur in realistic situations by parameterizing a more detailed model fitting the biology of the Black Sigatoka disease of banana, for which literature data are available. We discuss the implications of these results for research on and management of Sigatoka diseases of banana.

  7. Patterns of natural fungal community assembly during initial decay of coniferous and broadleaf tree logs

    NARCIS (Netherlands)

    van der Wal, A.; Klein Gunnewiek, P.J.A.; Cornelissen, J.H.C.; Crowther, T.W.; de Boer, W..

    2016-01-01

    Community assembly processes do not only influence community structure, but can also affect ecosystem processes. To understand the effect of initial community development on ecosystem processes, we studied natural fungal community dynamics during initial wood decay. We hypothesize that fungal

  8. Molecular evolution and the natural history of select virus epidemics

    DEFF Research Database (Denmark)

    Bruhn, Christian Anders Wathne

    Molecular evolution of pathogenic viruses with RNA based genomes is most often fast enough to leave an informative genomic sequence signal within a timeframe that is relevant for the study of both recent and on-­‐going epidemics (and epizootics). The true power of molecular evolutionary methodolo...

  9. Natural occurrence of fungi and fungal metabolites in moldy tomatoes

    DEFF Research Database (Denmark)

    Andersen, B.; Frisvad, Jens Christian

    2004-01-01

    Fresh tomatoes, homegrown and from supermarkets, with developing fungal lesions were collected. Each lesion was sampled, and the resulting fungal cultures were identified morphologically, and extracted for analyzes of secondary metabolites. The tomatoes were incubated at 25 degreesC for a week....... extracted, and analyzed for fungal metabolites. Extracts from pure cultures were compared with extracts from the moldy tomatoes and fungal metabolite standards in two HPLC systems with DAD and FLD detection. The results showed that Penicillium tularense, Stemphylium eturmiunum. and S. cf. lycopersici were...

  10. A modelling framework to simulate foliar fungal epidemics using functional-structural plant models.

    Science.gov (United States)

    Garin, Guillaume; Fournier, Christian; Andrieu, Bruno; Houlès, Vianney; Robert, Corinne; Pradal, Christophe

    2014-09-01

    Sustainable agriculture requires the identification of new, environmentally responsible strategies of crop protection. Modelling of pathosystems can allow a better understanding of the major interactions inside these dynamic systems and may lead to innovative protection strategies. In particular, functional-structural plant models (FSPMs) have been identified as a means to optimize the use of architecture-related traits. A current limitation lies in the inherent complexity of this type of modelling, and thus the purpose of this paper is to provide a framework to both extend and simplify the modelling of pathosystems using FSPMs. Different entities and interactions occurring in pathosystems were formalized in a conceptual model. A framework based on these concepts was then implemented within the open-source OpenAlea modelling platform, using the platform's general strategy of modelling plant-environment interactions and extending it to handle plant interactions with pathogens. New developments include a generic data structure for representing lesions and dispersal units, and a series of generic protocols to communicate with objects representing the canopy and its microenvironment in the OpenAlea platform. Another development is the addition of a library of elementary models involved in pathosystem modelling. Several plant and physical models are already available in OpenAlea and can be combined in models of pathosystems using this framework approach. Two contrasting pathosystems are implemented using the framework and illustrate its generic utility. Simulations demonstrate the framework's ability to simulate multiscaled interactions within pathosystems, and also show that models are modular components within the framework and can be extended. This is illustrated by testing the impact of canopy architectural traits on fungal dispersal. This study provides a framework for modelling a large number of pathosystems using FSPMs. This structure can accommodate both

  11. Patterns of natural fungal community assembly during initial decay of coniferous and broadleaf tree logs

    NARCIS (Netherlands)

    Wal, van der Annemieke; Klein Gunnewiek, P.J.A.; Cornelissen, J.H.C.; Crowther, Thomas W.; Boer, de Wietse

    2016-01-01

    Community assembly processes do not only influence community structure, but can also affect ecosystem processes. To understand the effect of initial community development on ecosystem processes, we studied natural fungal community dynamics during initial wood decay. We hypothesize that fungal

  12. Comparison of bacterial and fungal communities between natural and planted pine forests in subtropical China.

    Science.gov (United States)

    Nie, Ming; Meng, Han; Li, Ke; Wan, Jia-Rong; Quan, Zhe-Xue; Fang, Chang-Ming; Chen, Jia-Kuan; Li, Bo

    2012-01-01

    To improve our understanding of the changes in bacterial and fungal diversity in natural pine and planted forests in subtropical region of China, we examined bacterial and fungal communities from a native and a nearby planted pine forest of the Mt. Lushan by constructing clone libraries of 16S and 18S rRNA genes. For bacterial communities, Proteobacteria and Acidobacteria were dominant bacterial taxa in both two types of forest soils. The Shannon-Wiener diversity index, rarefaction curve analysis, and LibShuff analysis suggest that these two forests contained similar diversity of bacterial communities. Low soil acidity (pH ≈ 4) of our study forests might be one of the most important selection factors determining growth of acidophilic Acidobacteria and Proteobacteria. However, the natural forest harbored greater level of fungal diversity than the planted forest according to the Shannon-Wiener diversity index and rarefaction curve analysis. Basidiomycota and Ascomycota were dominant fungal taxa in the soils of natural and planted forests, respectively. Our results suggest that fungal community was more sensitive than the bacterial community in characterizing the differences in plant cover impacts on the microbial flora in the natural and planted forests. The natural and planted forests may function differently due to the differences in soil fungal diversity and relative abundance.

  13. Photostability of Natural Orange-Red and Yellow Fungal Pigments in Liquid Food Model Systems

    DEFF Research Database (Denmark)

    Mapari, Sameer Shamsuddin; Meyer, Anne S.; Thrane, Ulf

    2009-01-01

    The variation in the photostability among the currently authorized natural pigments limits their application span to a certain type of food system, and more robust alternatives are being sought after to overcome this problem. In the present study, the photostability of an orange-red and a yellow...... an enhanced photostability of fungal pigment extracts compared to the commercially available natural colorants Monascus Red and turmeric used as controls. Yellow components of the orange-red fungal pigment extract were more photostable than the red components. Chemistry of the photodegradation of the orange...

  14. Exploring the natural fungal biodiversity of tropical and temperate forests toward improvement of biomass conversion.

    Science.gov (United States)

    Berrin, Jean-Guy; Navarro, David; Couturier, Marie; Olivé, Caroline; Grisel, Sacha; Haon, Mireille; Taussac, Sabine; Lechat, Christian; Courtecuisse, Régis; Favel, Anne; Coutinho, Pedro M; Lesage-Meessen, Laurence

    2012-09-01

    In this study, natural fungal diversity in wood-decaying species was explored for biomass deconstruction. In 2007 and 2008, fungal isolates were collected in temperate forests mainly from metropolitan France and in tropical forests mainly from French Guiana. We recovered and identified 74 monomorph cultures using morphological and molecular identification tools. Following production of fungal secretomes under inductive conditions, we evaluated the capacity of these fungal strains to potentiate a commercial Trichoderma reesei cellulase cocktail for the release of soluble sugars from biomass. The secretome of 19 isolates led to an improvement in biomass conversion of at least 23%. Of the isolates, the Trametes gibbosa BRFM 952 (Banque de Ressources Fongiques de Marseille) secretome performed best, with 60% improved conversion, a feature that was not universal to the Trametes and related genera. Enzymatic characterization of the T. gibbosa BRFM 952 secretome revealed an unexpected high activity on crystalline cellulose, higher than that of the T. reesei cellulase cocktail. This report highlights the interest in a systematic high-throughput assessment of collected fungal biodiversity to improve the enzymatic conversion of lignocellulosic biomass. It enabled the unbiased identification of new fungal strains issued from biodiversity with high biotechnological potential.

  15. Evaluation of fungal laccase immobilized on natural nanostructured bacterial cellulose

    Directory of Open Access Journals (Sweden)

    Lin eChen

    2015-11-01

    Full Text Available The aim of this work was to assess the possibility of using native bacterial nanocellulose (BC as a carrier for laccase immobilization. BC was synthesized by Gluconacetobacter xylinus, which was statically cultivated in a mannitol-based medium and was freeze-dried to form BC sponge after purification. For the first time, fungal laccase from Trametes versicolor was immobilized on the native nanofibril network-structured BC sponge through physical adsorption and cross-linking with glutaraldehyde. The properties including morphologic and structural features of the BC as well as the immobilized enzyme were thoroughly investigated. It was found that enzyme immobilized by cross-linking exhibited broader pH operation range of high catalytic activity as well as higher running stability compared to free and adsorbed enzyme. Using ABTS as substrate, the optimum pH value was 3.5 for the adsorption-immobilized laccase and 4.0 for the crosslinking-immobilized laccase. The immobilized enzyme retained 69% of the original activity after being recycled 7 times. Novel applications of the BC-immobilized enzyme tentatively include active packaging, construction of biosensors, and establishment of bioreactors.

  16. Natural and recombinant fungal laccases for paper pulp bleaching

    NARCIS (Netherlands)

    Sigoillot, C.; Record, E.; Belle, V.; Robert, J.L.; Levasseur, A.; Punt, P.J.; Hondel, C.A.M.J.J. van den; Fournel, A.; Sigoillot, J.C.; Asther, M.

    2004-01-01

    Three laccases, a natural form and two recombinant forms obtained from two different expression hosts, were characterized and compared for paper pulp bleaching. Laccase from Pycnoporus cinnabarinus, a well known lignolytic fungus, was selected as a reference for this study. The corresponding

  17. An endophytic fungus isolated from finger millet (Eleucine coracona produces anti-fungal natural products

    Directory of Open Access Journals (Sweden)

    Walaa Kamel Mousa

    2015-10-01

    Full Text Available Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes that contribute to the antifungal activity. Here we report the first isolation of endophyte(s from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp. was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation.

  18. An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products.

    Science.gov (United States)

    Mousa, Walaa K; Schwan, Adrian; Davidson, Jeffrey; Strange, Philip; Liu, Huaizhi; Zhou, Ting; Auzanneau, France-Isabelle; Raizada, Manish N

    2015-01-01

    Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes) that contribute to the antifungal activity. Here we report the first isolation of endophyte(s) from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp.) was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol, and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation.

  19. Molecular Characterization of Natural Fungal Flora in Black Olives: From Field to Table

    Directory of Open Access Journals (Sweden)

    Nisa Ozsoy

    2017-08-01

    Full Text Available In this study, molecular markers were used to determine fungal flora in black olive fruits from field surveys to the table, following the fermentation process. Field samples were collected from different locations of Canakkale province, including Gokceada (Imbros, where organic farming is employed. Some of the fruits from field samples were used for black table olive production and then fungal flora was tracked during the fermentation process. Fungal isolation was also conducted on some commercial samples. Fifty seven isolates from field samples, 56 isolates from the fermentation process and 17 isolates from commercial products were obtained. Among these isolates, 41 Alternaria, 43 Penicillium, 19 Aspergillus, 8 Monascus and 19 other genera were determined using amplified sizes of the Beta-tubulin gene region. Species level identification was carried out based on sequences of Beta-tubulin amplicons, which provided accurate identification, especially where the genera were morphologically highly similar. The occurrence and prevalence of fungal species changed in fungal collections from the field to the fermentation process. While Alternaria alternata was common in field samples, they were absent during fermentation. Many of these identified species, such as Penicillium expansum, Aspergillus niger and Monascus pilosus, which are known as potential toxin producers such as aflatoxin, ochratoxin A and citrinin, were found both in natural and fermented samples, even at the end of the fermentation process. These results showed that some fungal species which survive on olives from the field to the table are potential toxin producers and can be successfully characterized by amplification and sequencing of Beta-tubulin gene.

  20. Exploring fungal biodiversity for the production of water-soluble pigments as potential natural food colorants

    DEFF Research Database (Denmark)

    Mapari, Sameer Shamsuddin; Nielsen, Kristian Fog; Larsen, Thomas Ostenfeld

    2005-01-01

    The production of many currently authorized natural food colorants has a number of disadvantages, including a dependence on the supply of raw materials and variations in pigment extraction. Fungi provide a readily available alternative source of naturally derived food colorants that could easily...... be produced in high yields. The recent authorization of a fungal food colorant has fuelled research to explore the extraordinary chemical diversity and biodiversity of fungi for the biotechnological production of pigments as natural food colorants. These studies require an appropriate use of chernotaxonomic...... technology, in the future it should be possible to employ metabolic engineering to create microbial cell factories for the production of food colorants....

  1. [Epizootic and epidemic manifestation of natural foci of tularemia in Moscow region (1965-2013)].

    Science.gov (United States)

    Demidova, T N; Popov, V P; Polukhina, A N; Orlov, D S; Mescheryakova, I S; Mikhailova, T V

    2015-01-01

    Detection of contemporary features of tularemia focimanifestations, determination of territories of high epidemic risk in various landscape zones and creation of a map of foci territories of Moscow Region for isolation of tularemia infectious agent cultures and registered human morbidity for justified planning of prophylaxis measures. Report materials of epizootologic examinations of natural foci for 1965-2013, 156 maps of epidemiologic examination of cases of human infection with tularemia, results of studies of casting of predatory birds and dung of predatory mammals were used. Registered morbidity and isolation of tularemia infectious agent cultures from 1965 to date were applied to an electronic map of Moscow Region by sign method using modern. GIS-technologies (MapInfo 10.5 program). Electronic maps Ingit at 1:200,000 scale, as well as Google Earth program were used to search for base points. Analysis of morbidity has revealed structure change in human tularemia morbidity--an increase of the fraction of urban population and a decrease of the fraction of patients among rural inhabitants, unimmunized against this infection are mostly ill. The presence of DNA of tularemia causative agent in biological objects in the complex with serologic and bacteriological studies was shown to allow to detect flaccid epizootics even at low numbers of rodents. Cartographic reflection of registered morbidity and isolation of tularemia infectious agent cultures allowed to show territories with various degrees of epizootic activity and epidemic manifestation. Positive results of serologic and molecular-genetic studies of environmental objects gives evident on epizootic activity and constant risk of aggravation of epidemic situation for this infection.

  2. Effect of Fungal Deterioration on Physical and Mechanical Properties of Hemp and Flax Natural Fiber Composites

    Directory of Open Access Journals (Sweden)

    Bryn Crawford

    2017-10-01

    Full Text Available The development and application of bio-sourced composites have been gaining wide attention, yet their deterioration due to the growth of ubiquitous microorganisms during storage/manufacturing/in-service phases is still not fully understood for optimum material selection and design purposes. In this study, samples of non-woven flax fibers, hemp fibers, and mats made of co-mingled randomly-oriented flax or hemp fiber (50% and polypropylene fiber (50% were subjected to 28 days of exposure to (i no water-no fungi, (ii water only and (iii water along with the Chaetomium globosum fungus. Biocomposite samples were measured for weight loss over time, to observe the rate of fungal growth and the respiration of cellulose components in the fibers. Tensile testing was conducted to measure mechanical properties of the composite samples under different configurations. Scanning electron microscopy was employed to visualize fungal hyphal growth on the natural fibers, as well as to observe the fracture planes and failure modes of the biocomposite samples. Results showed that fungal growth significantly affects the dry mass as well as the tensile elastic modulus of the tested natural fiber mats and composites, and the effect depends on both the type and the length scale of fibers, as well as the exposure condition and time.

  3. Meteorological factors associated with abundance of airborne fungal spores over natural vegetation

    Science.gov (United States)

    Crandall, Sharifa G.; Gilbert, Gregory S.

    2017-08-01

    The abundance of airborne fungal spores in agricultural and urban settings increases with greater air temperature, relative humidity, or precipitation. The same meteorological factors that affect temporal patterns in spore abundance in managed environments also vary spatially across natural habitats in association with differences in vegetation structure. Here we investigated how temporal and spatial variation in aerial spore abundance is affected by abiotic (weather) and biotic (vegetation) factors as a foundation for predicting how fungi may respond to changes in weather and land-use patterns. We measured the phenology of airborne fungal spores across a mosaic of naturally occurring vegetation types at different time scales to describe (1) how spore abundance changes over time, (2) which local meteorological variables are good predictors for airborne spore density, and (3) whether spore abundance differs across vegetation types. Using an air volumetric vacuum sampler, we collected spore samples at 3-h intervals over a 120-h period in a mixed-evergreen forest and coastal prairie to measure diurnal, nocturnal, and total airborne spore abundance across vegetation types. Spore samples were also collected at weekly and monthly intervals in mixed-evergreen forest, redwood forest, and maritime chaparral vegetation types from 12 field sites across two years. We found greater airborne spore densities during the wetter winter months compared to the drier summer months. Mean total spore abundance in the mixed-evergreen forest was twice than in the coastal prairie, but there were no significant differences in total airborne spore abundance among mixed-evergreen forest, redwood forest, and maritime chaparral vegetation types. Weekly and monthly peaks in airborne spore abundance corresponded with rain events and peaks in soil moisture. Overall, temporal patterns in meteorological factors were much more important in determining airborne fungal spore abundance than the

  4. Spatial statistical analysis of basal stem root disease under natural field epidemic of oil palm

    Science.gov (United States)

    Kamu, Assis; Phin, Chong Khim; Seman, Idris Abu; Wan, Hoong Hak; Mun, Ho Chong

    2015-02-01

    Oil palm or scientifically known as Elaeis guineensis Jacq. is the most important commodity crop in Malaysia and has greatly contributed to the economy growth of the country. As far as disease is concerned in the industry, Basal Stem Rot (BSR) caused by Ganoderma boninence remains the most important disease. BSR disease is the most widely studied with information available for oil palm disease in Malaysia. However, there is still limited study on the spatial as well as temporal pattern or distribution of the disease especially under natural field epidemic condition in oil palm plantation. The objective of this study is to spatially identify the pattern of BSR disease under natural field epidemic using two geospatial analytical techniques, which are quadrat analysis for the first order properties of partial pattern analysis and nearest-neighbor analysis (NNA) for the second order properties of partial pattern analysis. Two study sites were selected with different age of tree. Both sites are located in Tawau, Sabah and managed by the same company. The results showed that at least one of the point pattern analysis used which is NNA (i.e. the second order properties of partial pattern analysis) has confirmed the disease is complete spatial randomness. This suggests the spread of the disease is not from tree to tree and the age of palm does not play a significance role in determining the spatial pattern of the disease. From the spatial pattern of the disease, it would help in the disease management program and for the industry in the future. The statistical modelling is expected to help in identifying the right model to estimate the yield loss of oil palm due to BSR disease in the future.

  5. Community Structure and Succession Regulation of Fungal Consortia in the Lignocellulose-Degrading Process on Natural Biomass

    Directory of Open Access Journals (Sweden)

    Baoyu Tian

    2014-01-01

    Full Text Available The study aims to investigate fungal community structures and dynamic changes in forest soil lignocellulose-degrading process. rRNA gene clone libraries for the samples collected in different stages of lignocellulose degradation process were constructed and analyzed. A total of 26 representative RFLP types were obtained from original soil clone library, including Mucoromycotina (29.5%, unclassified Zygomycetes (33.5%, Ascomycota (32.4%, and Basidiomycota (4.6%. When soil accumulated with natural lignocellulose, 16 RFLP types were identified from 8-day clone library, including Basidiomycota (62.5%, Ascomycota (36.1%, and Fungi incertae sedis (1.4%. After enrichment for 15 days, identified 11 RFLP types were placed in 3 fungal groups: Basidiomycota (86.9%, Ascomycota (11.5%, and Fungi incertae sedis (1.6%. The results showed richer, more diversity and abundance fungal groups in original forest soil. With the degradation of lignocellulose, fungal groups Mucoromycotina and Ascomycota decreased gradually, and wood-rotting fungi Basidiomycota increased and replaced the opportunist fungi to become predominant group. Most of the fungal clones identified in sample were related to the reported lignocellulose-decomposing strains. Understanding of the microbial community structure and dynamic change during natural lignocellulose-degrading process will provide us with an idea and a basis to construct available commercial lignocellulosic enzymes or microbial complex.

  6. Community structure and succession regulation of fungal consortia in the lignocellulose-degrading process on natural biomass.

    Science.gov (United States)

    Tian, Baoyu; Wang, Chunxiang; Lv, Ruirui; Zhou, Junxiong; Li, Xin; Zheng, Yi; Jin, Xiangyu; Wang, Mengli; Ye, Yongxia; Huang, Xinyi; Liu, Ping

    2014-01-01

    The study aims to investigate fungal community structures and dynamic changes in forest soil lignocellulose-degrading process. rRNA gene clone libraries for the samples collected in different stages of lignocellulose degradation process were constructed and analyzed. A total of 26 representative RFLP types were obtained from original soil clone library, including Mucoromycotina (29.5%), unclassified Zygomycetes (33.5%), Ascomycota (32.4%), and Basidiomycota (4.6%). When soil accumulated with natural lignocellulose, 16 RFLP types were identified from 8-day clone library, including Basidiomycota (62.5%), Ascomycota (36.1%), and Fungi incertae sedis (1.4%). After enrichment for 15 days, identified 11 RFLP types were placed in 3 fungal groups: Basidiomycota (86.9%), Ascomycota (11.5%), and Fungi incertae sedis (1.6%). The results showed richer, more diversity and abundance fungal groups in original forest soil. With the degradation of lignocellulose, fungal groups Mucoromycotina and Ascomycota decreased gradually, and wood-rotting fungi Basidiomycota increased and replaced the opportunist fungi to become predominant group. Most of the fungal clones identified in sample were related to the reported lignocellulose-decomposing strains. Understanding of the microbial community structure and dynamic change during natural lignocellulose-degrading process will provide us with an idea and a basis to construct available commercial lignocellulosic enzymes or microbial complex.

  7. Prevention of fungal spoilage in food products using natural compounds: A review.

    Science.gov (United States)

    Ribes, Susana; Fuentes, Ana; Talens, Pau; Barat, Jose Manuel

    2017-04-10

    The kingdom Fungi is the most important group of microorganism contaminating food commodities, and chemical additives are commonly used in the food industry to prevent fungal spoilage. However, the increasing consumer concern about synthetic additives has led to their substitution by natural compounds in foods. The current review provides an overview of using natural agents isolated from different sources (plants, animals, and microorganisms) as promising antifungal compounds, including information about their mechanism of action and their use in foods to preserve and prolong shelf life. Compounds derived from plants, chitosan, lactoferrin, and biocontrol agents (lactic acid bacteria, antagonistic yeast, and their metabolites) are able to control the decay caused by fungi in a wide variety of foods. Several strategies are employed to reduce the drawbacks of some antifungal agents, like their incorporation into oil-in-water emulsions and nanoemulsions, edible films and active packaging, and their combination with other natural preservatives. These strategies facilitate the addition of volatile agents into food products and, improve their antifungal effectiveness. Moreover, biological agents have been investigated as one of the most promising options in the control of postharvest decay. Numerous mechanisms of action have been elucidated and different approaches have been studied to enhance their antifungal effectiveness.

  8. Ectomycorrhizal Fungal Communities in Urban Parks Are Similar to Those in Natural Forests but Shaped by Vegetation and Park Age.

    Science.gov (United States)

    Hui, Nan; Liu, Xinxin; Kotze, D Johan; Jumpponen, Ari; Francini, Gaia; Setälä, Heikki

    2017-12-01

    Ectomycorrhizal (ECM) fungi are important mutualists for the growth and health of most boreal trees. Forest age and its host species composition can impact the composition of ECM fungal communities. Although plentiful empirical data exist for forested environments, the effects of established vegetation and its successional trajectories on ECM fungi in urban greenspaces remain poorly understood. We analyzed ECM fungi in 5 control forests and 41 urban parks of two plant functional groups (conifer and broadleaf trees) and in three age categories (10, ∼50, and >100 years old) in southern Finland. Our results show that although ECM fungal richness was marginally greater in forests than in urban parks, urban parks still hosted rich and diverse ECM fungal communities. ECM fungal community composition differed between the two habitats but was driven by taxon rank order reordering, as key ECM fungal taxa remained largely the same. In parks, the ECM communities differed between conifer and broadleaf trees. The successional trajectories of ECM fungi, as inferred in relation to the time since park construction, differed among the conifers and broadleaf trees: the ECM fungal communities changed over time under the conifers, whereas communities under broadleaf trees provided no evidence for such age-related effects. Our data show that plant-ECM fungus interactions in urban parks, in spite of being constructed environments, are surprisingly similar in richness to those in natural forests. This suggests that the presence of host trees, rather than soil characteristics or even disturbance regime of the system, determine ECM fungal community structure and diversity. IMPORTANCE In urban environments, soil and trees improve environmental quality and provide essential ecosystem services. ECM fungi enhance plant growth and performance, increasing plant nutrient acquisition and protecting plants against toxic compounds. Recent evidence indicates that soil-inhabiting fungal communities

  9. [THE EPIZOOTIC AND EPIDEMIC ACTIVITY OF NATURAL TULAREMIA FOCI OF DIFFERENT LANDSCAPE EPIDEMIOLOGICAL TYPES IN 2009-2014].

    Science.gov (United States)

    Meshcheryakova, I S; Mikhailova, T V; Demidova, T N; Kormilitsyna, M I

    2016-01-01

    to assess the present state of the natural tularemia foci of different landscape epidemiological types, by using individual focal areas as an example. Epizootological monitoring and epidemiological analysis were conducted in the areas of natural tularemia foci of tundra (Wrangel Island), meadow-field (Central Federal District of the Russian Federation), flood-swamp (Arkhangelsk Region, Khanty-Mansi Autonomous District), and steppe (Mongolii) types. Small mammals (organs, blood), tularemia patients' sera, and environniental objects were examined. Molecular genetic and immune serological diagnostic assays were used. The incidence of tularemia in the past decade was analyzed using the maps for the epidemiological examinations of tularemia cases and medical reports. The natural foci of tularemia were established to continue to actively operate. There were 2913 cases of tularemia in the Russian Federation in 2001 to 2014. The flood-swamp natural foci, in which there were summer transmissive tularemia outbreaks, the largest of high occurred in Khanti-Mansiysk in 2013 when a total of 1005 people fell ill, are a special epidemic hazard. Analysis of the tularemia outbreaks suggests that there is a need for continuous epizootological monitoring of the areas of natural tularemia foci for the timely prediction and prevention of epidemic complications. It is noted that there is an unfounded reduction in the scope of preventive measures, and immunoprevention in particular, and a weaker control of the antitularemia immune status in the population residing in the area of active natural foci of tularemia.

  10. Lichensphere: a protected natural microhabitat of the non-lichenised fungal communities living in extreme environments of Antarctica.

    Science.gov (United States)

    Santiago, Iara F; Soares, Marco Aurélio; Rosa, Carlos A; Rosa, Luiz H

    2015-11-01

    We surveyed the diversity, distribution and ecology of non-lichenised fungal communities associated with the Antarctic lichens Usnea antarctica and Usnea aurantiaco-atra across Antarctica. The phylogenetic study of the 438 fungi isolates identified 74 taxa from 21 genera of Ascomycota, Basidiomycota and Zygomycota. The most abundant taxa were Pseudogymnoascus sp., Thelebolus sp., Antarctomyces psychrotrophicus and Cryptococcus victoriae, which are considered endemic and/or highly adapted to Antarctica. Thirty-five fungi may represent new and/or endemic species. The fungal communities displayed high diversity, richness and dominance indices; however, the similarity among the communities was variable. After discovering rich and diverse fungal communities composed of symbionts, decomposers, parasites and endemic and cold-adapted cosmopolitan taxa, we introduced the term "lichensphere". We hypothesised that the lichensphere may represent a protected natural microhabitat with favourable conditions able to help non-lichenised fungi and other Antarctic life forms survive and disperse in the extreme environments of Antarctica.

  11. Manure treatment and natural inactivation of porcine epidemic diarrhea virus in soils

    Science.gov (United States)

    The outbreak of porcine epidemic diarrhea virus (PEDv) in North America has substantially impacted U.S. swine production in recent years. The virus it is easily transmitted among pigs and causes nearly 100% mortality in pre-weaned piglets. Because PEDv is an enteric virus spread via fecal-oral conta...

  12. Higher fungal diversity is correlated with lower CO2 emissions from dead wood in a natural forest.

    Science.gov (United States)

    Yang, Chunyan; Schaefer, Douglas A; Liu, Weijie; Popescu, Viorel D; Yang, Chenxue; Wang, Xiaoyang; Wu, Chunying; Yu, Douglas W

    2016-08-24

    Wood decomposition releases almost as much CO2 to the atmosphere as does fossil-fuel combustion, so the factors regulating wood decomposition can affect global carbon cycling. We used metabarcoding to estimate the fungal species diversities of naturally colonized decomposing wood in subtropical China and, for the first time, compared them to concurrent measures of CO2 emissions. Wood hosting more diverse fungal communities emitted less CO2, with Shannon diversity explaining 26 to 44% of emissions variation. Community analysis supports a 'pure diversity' effect of fungi on decomposition rates and thus suggests that interference competition is an underlying mechanism. Our findings extend the results of published experiments using low-diversity, laboratory-inoculated wood to a high-diversity, natural system. We hypothesize that high levels of saprotrophic fungal biodiversity could be providing globally important ecosystem services by maintaining dead-wood habitats and by slowing the atmospheric contribution of CO2 from the world's stock of decomposing wood. However, large-scale surveys and controlled experimental tests in natural settings will be needed to test this hypothesis.

  13. Hybrid combinations containing natural products and antimicrobial drugs that interfere with bacterial and fungal biofilms.

    Science.gov (United States)

    Zacchino, Susana A; Butassi, Estefanía; Cordisco, Estefanía; Svetaz, Laura A

    2017-12-15

    works respectively. Regarding combinations against bacterial biofilms, in vitro studies were performed in all works by using several different methods of higher variety than the used against fungal biofilms. Biofilms of both the gram (+) and gram (-) bacteria were prepared, although biofilm of Staphylococcus spp. were the most used in the collected works. Among the discovered potentiators of antibacterial drugs, 75% were terpenes, including mono, di- and triterpenes, and, among the atibacterial drugs, several structurally diverse types were used in the combinations: aminoglycosides, β-lactams, glucopeptides and fluoroquinolones. The potentiating capacity of natural products, mainly terpenes, on the antibiofilm effect of antimicrobial drugs opens a wide range of possibilities for the combination antimicrobial therapy. More in vivo studies on combinations of natural products with antimicrobial drugs acting against biofilms are highly required to cope the difficult to treat biofilm-associated infections. Copyright © 2017 Elsevier GmbH. All rights reserved.

  14. Bacterial and fungal communities in a degraded ombrotrophic peatland undergoing natural and managed re-vegetation.

    Science.gov (United States)

    Elliott, David R; Caporn, Simon J M; Nwaishi, Felix; Nilsson, R Henrik; Sen, Robin

    2015-01-01

    The UK hosts 15-19% of global upland ombrotrophic (rain fed) peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6) and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals). Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in relation to bare peat

  15. Bacterial and fungal communities in a degraded ombrotrophic peatland undergoing natural and managed re-vegetation.

    Directory of Open Access Journals (Sweden)

    David R Elliott

    Full Text Available The UK hosts 15-19% of global upland ombrotrophic (rain fed peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6 and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals. Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in

  16. Bacterial and Fungal Communities in a Degraded Ombrotrophic Peatland Undergoing Natural and Managed Re-Vegetation

    Science.gov (United States)

    Elliott, David R.; Caporn, Simon J. M.; Nwaishi, Felix; Nilsson, R. Henrik; Sen, Robin

    2015-01-01

    The UK hosts 15–19% of global upland ombrotrophic (rain fed) peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6) and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals). Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in relation to bare

  17. Encountering epidemic effects of leaf spot disease (Alternaria brassicae) on Aloe vera by fungal biocontrol agents in agrifields-An ecofriendly approach.

    Science.gov (United States)

    Ghosh, Swapan Kumar; Banerjee, Subhankar; Pal, Sujoy; Chakraborty, Niloy

    2018-01-01

    Aloe vera (L.) Burm.f. is a highly important and extensively cultivated medicinal plant and that is also extensively used in the cosmetic industry. It has been frequently reported to suffer from Alternaria leaf spot disease in various parts of the world. Various fungicides used to combat this disease, have deleterious effects on the environment and on pharmacologically important constituents of Aloe vera. To avoid the harmful effects of fungicides an ecofriendly approach has been adopted here. A weekly survey was conducted during 2013-2015 in and around North 24 Parganas (West Bengal) to obtain the percentage of disease index (PDI). For biological control of the disease, screening of the antagonistic efficacy of biocontrol agents was carried out through the in vitro dual-culture-plate method and scanning electron microscopy (SEM) was used to study the mechanism. The in vitro effects of fungicides on the radial growth of the pathogen were evaluated through the poison food method and were compared with potent antagonistic fungi. Field application of potent antagonistic fungi was conducted through the dip-and-spray method. The results showed that, the PDI peaked during the hot and humid conditions of May to September (76.57%-98.57%) but decreased during the winter, December-January (35.71-46.66%). Trichoderma asperellum exerted the greatest inhibition of the radial growth of A. brassicae acting through non volatile (70.39%) and volatile metabolites (72.17%). A SEM study confirmed the hyperparasitic nature of T. asperellum through hyphal coiling-T. asperellum was similar to 2% blitox-50 (73.92%) and better than 2% bavistin (59.77%) (in vitro). In agricultural field trials (2013-15), Trichoderma application restricted the disease to the smallest area (PDI 24.00-29.33%) in comparison to untreated plots (73.33%). In conclusion, saplings treated with the dip method (108 spores / mL) and sprayed 4 times with a spore suspension of biocontrol agents such as T. asperellum, T

  18. Identification of potentially safe promising fungal cell factories for the production of polyketide natural food colorants using chemotaxonomic rationale

    DEFF Research Database (Denmark)

    Mapari, Sameer Shamsuddin; Meyer, Anne S.; Thrane, Ulf

    2009-01-01

    Background: Colorants derived from natural sources look set to overtake synthetic colorants in market value as manufacturers continue to meet the rising demand for clean label ingredients-particularly in food applications. Many ascomycetous fungi naturally synthesize and secrete pigments and thus...... has not yet been examined in detail. In addition, 4 out of the 10 chemotaxonomically selected promising Penicillium strains were shown to produce extracellular pigments in the liquid media using a solid support indicating future cell factory possibilities for polyketide natural food colorants....... provide readily available additional and/or alternative sources of natural colorants that are independent of agro-climatic conditions. With an appropriately selected fungus; using in particular chemotaxonomy as a guide, the fungal natural colorants could be produced in high yields by using the optimized...

  19. Fungal microsomes in a biotransformation perspective: protein nature of membrane-associated reactions

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Kateřina; Mikesková, Hana; Petráčková, Denisa

    2013-01-01

    Roč. 97, č. 24 (2013), s. 10263-10273 ISSN 0175-7598 R&D Projects: GA TA ČR TE01020218 Institutional support: RVO:61388971 Keywords : Fungal microsomes * Cytochrome P450 * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 3.811, year: 2013

  20. Mechanical soil disturbance as a determinant of arbuscular mycorrhizal fungal communities in semi-natural grassland

    DEFF Research Database (Denmark)

    Schnoor, Tim Krone; Lekberg, Ylva; Rosendahl, Søren

    2011-01-01

    an ongoing grassland restoration experiment that contained replicated plowed and control plots. The AM fungal community in roots was determined using nested PCR and LSU rDNA primers. We identified 38 phylotypes within the Glomeromycota, of which 29 belonged to Glomus A, six to Glomus B, and three...

  1. Diversity of dead wood inhabiting fungal and bryophytes in semi-natural beech forests in Europe

    NARCIS (Netherlands)

    Ódor, P.; Heilmann-Clausen, J.; Christensen, M.; Aude, E.; Dort, van K.W.; Piltaver, A.; Siller, I.; Veerkamp, M.T.; Walleyn, R.; Standovár, T.; Hees, van A.F.M.; Kosec, J.; Matocec, N.; Kraigher, H.; Grebenc, T.

    2006-01-01

    Saproxylic organisms are among the most threatened species in Europe and constitute a major conservation problem because they depend on the most important forestry product - dead wood. Diversity of fungal and bryophyte communities occurring on dead beech trees was analyzed in five European countries

  2. Several genes encoding enzymes with the same activity are necessary for aerobic fungal degradation of cellulose in nature.

    Directory of Open Access Journals (Sweden)

    Peter K Busk

    Full Text Available The cellulose-degrading fungal enzymes are glycoside hydrolases of the GH families and lytic polysaccharide monooxygenases. The entanglement of glycoside hydrolase families and functions makes it difficult to predict the enzymatic activity of glycoside hydrolases based on their sequence. In the present study we further developed the method Peptide Pattern Recognition to an automatic approach not only to find all genes encoding glycoside hydrolases and lytic polysaccharide monooxygenases in fungal genomes but also to predict the function of the genes. The functional annotation is an important feature as it provides a direct route to predict function from primary sequence. Furthermore, we used Peptide Pattern Recognition to compare the cellulose-degrading enzyme activities encoded by 39 fungal genomes. The results indicated that cellobiohydrolases and AA9 lytic polysaccharide monooxygenases are hallmarks of cellulose-degrading fungi except brown rot fungi. Furthermore, a high number of AA9, endocellulase and β-glucosidase genes were identified, not in what are known to be the strongest, specialized lignocellulose degraders but in saprophytic fungi that can use a wide variety of substrates whereas only few of these genes were found in fungi that have a limited number of natural, lignocellulotic substrates. This correlation suggests that enzymes with different properties are necessary for degradation of cellulose in different complex substrates. Interestingly, clustering of the fungi based on their predicted enzymes indicated that Ascomycota and Basidiomycota use the same enzymatic activities to degrade plant cell walls.

  3. Daphnia can protect diatoms from fungal parasitism

    NARCIS (Netherlands)

    Kagami, M.; Van Donk, E.; De Bruin, A.; Rijkeboer, M.; Ibelings, B.W.

    2004-01-01

    Many phytoplankton species are susceptible to chytrid fungal parasitism. Much attention has been paid to abiotic factors that determine whether fungal infections become epidemic. It is still unknown, however, how biotic factors, such as interactions with zooplankton, affect the fungal infection

  4. Identification of potentially safe promising fungal cell factories for the production of polyketide natural food colorants using chemotaxonomic rationale

    Directory of Open Access Journals (Sweden)

    Frisvad Jens C

    2009-04-01

    Full Text Available Abstract Background Colorants derived from natural sources look set to overtake synthetic colorants in market value as manufacturers continue to meet the rising demand for clean label ingredients – particularly in food applications. Many ascomycetous fungi naturally synthesize and secrete pigments and thus provide readily available additional and/or alternative sources of natural colorants that are independent of agro-climatic conditions. With an appropriately selected fungus; using in particular chemotaxonomy as a guide, the fungal natural colorants could be produced in high yields by using the optimized cultivation technology. This approach could secure efficient production of pigments avoiding use of genetic manipulation. Results Polyketide pigment producing ascomycetous fungi were evaluated for their potential as production organisms based on a priori knowledge on species-specific pigment and potential mycotoxin production and BioSafety level (BSL classification. Based on taxonomic knowledge, we pre-selected ascomycetous fungi belonging to Penicillium subgenus Biverticillium that produced yellow, orange or red pigments while deselecting Penicillium marneffei; a well known human pathogen in addition to other mycotoxigenic fungi belonging to the same group. We identified 10 strains belonging to 4 species; viz. P. purpurogenum, P. aculeatum, P. funiculosum, and P. pinophilum as potential pigment producers that produced Monascus-like pigments but no known mycotoxins. The selection/deselection protocol was illustrated in the pigment extracts of P. aculeatum IBT 14259 and P. crateriforme IBT 5015 analysed by HPLC-DAD-MS. In addition, extracellular pigment producing ability of some of the potential pigment producers was evaluated in liquid media with a solid support and N-glutarylmonascorubramine was discovered in the partially purified pigment extract of P. purpurogenum IBT 11181 and IBT 3645. Conclusion The present work brought out that the use

  5. Two novel porcine epidemic diarrhea virus (PEDV) recombinants from a natural recombinant and distinct subtypes of PEDV variants.

    Science.gov (United States)

    Chen, Nanhua; Li, Shuangjie; Zhou, Rongyun; Zhu, Meiqin; He, Shan; Ye, Mengxue; Huang, Yucheng; Li, Shuai; Zhu, Cong; Xia, Pengpeng; Zhu, Jianzhong

    2017-10-15

    Porcine epidemic diarrhea virus (PEDV) causes devastating impact on global pig-breeding industry and current vaccines have become not effective against the circulating PEDV variants since 2011. During the up-to-date investigation of PEDV prevalence in Fujian China 2016, PEDV was identified in vaccinated pig farms suffering severe diarrhea while other common diarrhea-associated pathogens were not detected. Complete genomes of two PEDV representatives (XM1-2 and XM2-4) were determined. Genomic comparison showed that these two viruses share the highest nucleotide identities (99.10% and 98.79%) with the 2011 ZMDZY strain, but only 96.65% and 96.50% nucleotide identities with the attenuated CV777 strain. Amino acid alignment of spike (S) proteins indicated that they have the similar mutation, insertion and deletion pattern as other Chinese PEDV variants but also contain several unique substitutions. Phylogenetic analysis showed that 2016 PEDV variants belong to the cluster of recombination strains but form a new branch. Recombination detection suggested that both XM1-2 and XM2-4 are inter-subgroup recombinants with breakpoints within ORF1b. Remarkably, the natural recombinant HNQX-3 isolate serves as a parental virus for both natural recombinants identified in this study. This up-to-date investigation provides the direct evidence that natural recombinants may serve as parental viruses to generate recombined PEDV progenies that are probably associated with the vaccination failure. Copyright © 2017. Published by Elsevier B.V.

  6. Survey of fungal counts and natural occurrence of aflatoxins in Malaysian starch-based foods.

    Science.gov (United States)

    Abdullah, N; Nawawi, A; Othman, I

    1998-01-01

    In a survey of starch-based foods sampled from retail outlets in Malaysia, fungal colonies were mostly detected in wheat flour (100%), followed by rice flour (74%), glutinous rice grains (72%), ordinary rice grains (60%), glutinous rice flour (48%) and corn flour (26%). All positive samples of ordinary rice and glutinous rice grains had total fungal counts below 10(3) cfu/g sample, while among the positive rice flour, glutinous rice flour and corn flour samples, the highest total fungal count was more than 10(3) but less than 10(4) cfu/g sample respectively. However, in wheat flour samples total fungal count ranged from 10(2) cfu/g sample to slightly more than 10(4) cfu/g sample. Aflatoxigenic colonies were mostly detected in wheat flour (20%), followed by ordinary rice grains (4%), glutinous rice grains (4%) and glutinous rice flour (2%). No aflatoxigenic colonies were isolated from rice flour and corn flour samples. Screening of aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 using reversed-phase HPLC were carried out on 84 samples of ordinary rice grains and 83 samples of wheat flour. Two point four percent (2.4%) of ordinary rice grains were positive for aflatoxin G1 and 3.6% were positive for aflatoxin G2. All the positive samples were collected from private homes at concentrations ranging from 3.69-77.50 micrograms/kg. One point two percent (1.2%) of wheat flour samples were positive for aflatoxin B1 at a concentration of 25.62 micrograms/kg, 4.8% were positive for aflatoxin B2 at concentrations ranging from 11.25-252.50 micrograms/kg, 3.6% were positive for aflatoxin G1 at concentrations ranging from 25.00-289.38 micrograms/kg and 13.25% were positive for aflatoxin G2 at concentrations ranging from 16.25-436.25 micrograms/kg. Similarly, positive wheat flour samples were mostly collected from private homes.

  7. Inhibition of growth of highly resistant bacterial and fungal pathogens by a natural product.

    Science.gov (United States)

    Hafidh, Rand R; Abdulamir, Ahmed S; Vern, Law Se; Abu Bakar, Fatimah; Abas, Faridah; Jahanshiri, Fatemeh; Sekawi, Zamberi

    2011-01-01

    The continuous escalation of resistant bacteria against a wide range of antibiotics necessitates discovering novel unconventional sources of antibiotics. B. oleracea L (red cabbage) is health-promoting food with proven anticancer and anti-inflammatory activities. However, it has not been researched adequately for its antimicrobial activity on potential resistant pathogens. The methanol crude extract of B. oleracea L. was investigated for a possible anti-microbial activity. The screening method was conducted using disc diffusion assay against 22 pathogenic bacteria and fungi. It was followed by evaluation of the minimum inhibitory concentration (MIC). Moreover, the antibacterial and the antifungal activities were confirmed using the minimum bactericidal concentration (MBC) and the minimum fungicidal concentration (MFC), respectively. Remarkable, antibacterial activity was evident particularly against highly infectious microorganisms such as Methicillin-resistant Staphylococcus aureus, Escherichia coli O157:H7, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Salmonella enterica serovar Typhimurium as well as against human fungal pathogens, Trichophyton rubrum and Aspergillus terreus. Red cabbage is a rich source of phenolic compounds, anthocyanins being the most abundant class, which might explain its potent antimicrobial action. This extract is potentially novel for future antimicrobials, inexpensive, and readily available at a large scale for pharmaceutical companies for further investigation and processing.

  8. How does conversion of natural tropical rainforest ecosystems affect soil bacterial and fungal communities in the Nile river watershed of Uganda?

    OpenAIRE

    Alele, Peter O; Sheil, Douglas; Surget-Groba, Yann; Lingling, Shi; Cannon, Charles H

    2014-01-01

    Uganda's forests are globally important for their conservation values but are under pressure from increasing human population and consumption. In this study, we examine how conversion of natural forest affects soil bacterial and fungal communities. Comparisons in paired natural forest and human-converted sites among four locations indicated that natural forest soils consistently had higher pH, organic carbon, nitrogen, and calcium, although variation among sites was large. Despite these diffe...

  9. Potential Use of Native and Naturalized Insect Herbivores and Fungal Pathogens of Aquatic and Wetland Plants

    National Research Council Canada - National Science Library

    Freedman, Jan E; Grodowitz, Michael J; Swindle, Robin; Nachtrieb, Julie G

    2007-01-01

    ...) scientists to identify naturalized and/or native herbivores of aquatic plants in an effort to develop alternative management strategies through an understanding of the agents' biology and ecology...

  10. Freshwater Fungal Infections

    Directory of Open Access Journals (Sweden)

    Dennis J. Baumgardner

    2017-01-01

    Full Text Available Fungal infections as a result of freshwater exposure or trauma are fortunately rare. Etiologic agents are varied, but commonly include filamentous fungi and Candida. This narrative review describes various sources of potential freshwater fungal exposure and the diseases that may result, including fungal keratitis, acute otitis externa and tinea pedis, as well as rare deep soft tissue or bone infections and pulmonary or central nervous system infections following traumatic freshwater exposure during natural disasters or near-drowning episodes. Fungal etiology should be suspected in appropriate scenarios when bacterial cultures or molecular tests are normal or when the infection worsens or fails to resolve with appropriate antibacterial therapy.

  11. Functional Reconstitution of a Fungal Natural Product Gene Cluster by Advanced Genome Editing.

    Science.gov (United States)

    Weber, Jakob; Valiante, Vito; Nødvig, Christina S; Mattern, Derek J; Slotkowski, Rebecca A; Mortensen, Uffe H; Brakhage, Axel A

    2017-01-20

    Filamentous fungi produce varieties of natural products even in a strain dependent manner. However, the genetic basis of chemical speciation between strains is still widely unknown. One example is trypacidin, a natural product of the opportunistic human pathogen Aspergillus fumigatus, which is not produced among different isolates. Combining computational analysis with targeted gene editing, we could link a single nucleotide insertion in the polyketide synthase of the trypacidin biosynthetic pathway and reconstitute its production in a nonproducing strain. Thus, we present a CRISPR/Cas9-based tool for advanced molecular genetic studies in filamentous fungi, exploiting selectable markers separated from the edited locus.

  12. Arbuscular mycorrhizal fungal diversity and natural enemies promote coexistence of tropical tree species

    Science.gov (United States)

    Benedicte Bachelot; María Uriarte; Krista L. McGuire; Jill Thompson; Jess Zimmerman

    2017-01-01

    Negative population feedbacks mediated by natural enemies can promote species coexistence at the community scale through disproportionate mortality of numerically dominant (common) tree species. Simultaneously, associations with arbuscular mycorrhizal fungi (AMF) can result in positive effects on tree populations. Coupling data on seedling foliar damage from herbivores...

  13. The fungal composition of natural biofinishes on oil-treated wood

    NARCIS (Netherlands)

    van Nieuwenhuijzen, Elke J.; Houbraken, Jos A. M. P.; Punt, Peter J; Roeselers, Guus; Adan, Olaf C G; Samson, Robert A.

    2017-01-01

    Biofinished wood is considered to be a decorative and protective material for outdoor constructions, showing advantages compared to traditional treated wood in terms of sustainability and self-repair. Natural dark wood staining fungi are essential to biofinish formation on wood. Although all sorts

  14. The fungal composition of natural biofinishes on oil-treated wood

    NARCIS (Netherlands)

    van Nieuwenhuijzen, E.J.; Houbraken, J.A.M.P.; Punt, P.J.; Roeselers, G.; Adan, O.C.G.; Samson, R.A.

    2017-01-01

    Background Biofinished wood is considered to be a decorative and protective material for outdoor constructions, showing advantages compared to traditional treated wood in terms of sustainability and self-repair. Natural dark wood staining fungi are essential to biofinish formation on wood. Although

  15. Biocombinatorial Engineering of Fungal PKS-NRPS Hybrids for Production of Novel Synthetic Natural Products

    DEFF Research Database (Denmark)

    Nielsen, Maria Lund

    encoding a PKS-NRPS hybrid responsible for the production of a medically relevant compound in Talaromyces atroroseus. To the best of my knowledge, this study represents the first example of reverse engineering of a Talaromyces species. In the fourth study (chapter 5), I used the CRISPR-Cas9 system...... structure optimization. Within the last decade, an alternative approach for expanding natural product chemodiversity has been applied. This strategy, known as combinatorial biosynthesis, involves the re-engineering of biosynthetic pathways and ultimately the rational engineering of new natural product...... analogs. This field, however, has proved very challenging and many engineering efforts have resulted in enzymatic loss-of-function or reduced yields. Thus, the future success in combinatorial biosynthetic studies requires a thorough understanding of the structure and function of biosynthetic enzymes...

  16. Fungal Meningitis

    Science.gov (United States)

    ... Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Fungal Meningitis Language: English Spanish Recommend on Facebook Tweet Share ... the brain or spinal cord. Investigation of Fungal Meningitis, 2012 In September 2012, the Centers for Disease ...

  17. High-throughput sequencing for the detection of the bacterial and fungal diversity in Mongolian naturally fermented cow's milk in Russia.

    Science.gov (United States)

    Liu, Wenjun; Zheng, Yi; Kwok, Lai-Yu; Sun, Zhihong; Zhang, Jiachao; Guo, Zhuang; Hou, Qiangchuan; Menhe, Bilige; Zhang, Heping

    2015-02-22

    Traditional fermented dairy products are major components of the typical Mongolian diet since ancient times. However, almost all the previous studies on the microbial composition of traditional Mongolian fermented dairy products analyzed food samples from the Chinese Mongolian region and Mongolia but not the Russian Mongolian region. In this study, the bacterial and fungal community diversity of nineteen naturally fermented cow's milk (NFCM) samples from local Mongolian families residing in Kalmykia and Chita of Russia was investigated with pyrosequencing. Firmicutes and Ascomycota were the predominant phyla respectively for bacteria and fungi. The abundance of the bacterial phylum Acidobacteria was considerably different between the samples from the two regions. At genus level, Lactobacillus and Pichia were the predominating bacterial and fungal genera, respectively, while six bacterial genera significantly differed between the Kalmykia (enrichment of Aeromonas, Bacillus, Clostridium, Streptococcus, Vogesella) and Chita (enrichment of Lactococcus) samples. The results of principal coordinate analysis (PCoA) based on the bacterial or fungal composition of the Kalmykia and Chita samples revealed a different microbiota structure between the samples collected in these two locations. The redundancy analysis (RDA) identified 60 bacterial and 21 fungal OTUs as the key variables responsible for such microbiota structural difference. Our results suggest that structural differences existed in the microbiota of NFCM between Kalmykia and Chita. The difference in geographic environment may be an important factor influencing the microbial diversity of NFCM made by the Mongolians in Russia.

  18. How does conversion of natural tropical rainforest ecosystems affect soil bacterial and fungal communities in the Nile river watershed of Uganda?

    Directory of Open Access Journals (Sweden)

    Peter O Alele

    Full Text Available Uganda's forests are globally important for their conservation values but are under pressure from increasing human population and consumption. In this study, we examine how conversion of natural forest affects soil bacterial and fungal communities. Comparisons in paired natural forest and human-converted sites among four locations indicated that natural forest soils consistently had higher pH, organic carbon, nitrogen, and calcium, although variation among sites was large. Despite these differences, no effect on the diversity of dominant taxa for either bacterial or fungal communities was detected, using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE. Composition of fungal communities did generally appear different in converted sites, but surprisingly, we did not observe a consistent pattern among sites. The spatial distribution of some taxa and community composition was associated with soil pH, organic carbon, phosphorus and sodium, suggesting that changes in soil communities were nuanced and require more robust metagenomic methods to understand the various components of the community. Given the close geographic proximity of the paired sampling sites, the similarity between natural and converted sites might be due to continued dispersal between treatments. Fungal communities showed greater environmental differentiation than bacterial communities, particularly according to soil pH. We detected biotic homogenization in converted ecosystems and substantial contribution of β-diversity to total diversity, indicating considerable geographic structure in soil biota in these forest communities. Overall, our results suggest that soil microbial communities are relatively resilient to forest conversion and despite a substantial and consistent change in the soil environment, the effects of conversion differed widely among sites. The substantial difference in soil chemistry, with generally lower nutrient quantity in converted

  19. Several genes encoding enzymes with the same activity are necessary for aerobic fungal degradation of cellulose in nature

    DEFF Research Database (Denmark)

    Busk, Peter Kamp; Lange, Mette; Pilgaard, Bo

    2014-01-01

    The cellulose-degrading fungal enzymes are glycoside hydrolases of the GH families and lytic polysaccharide monooxygenases. The entanglement of glycoside hydrolase families and functions makes it difficult to predict the enzymatic activity of glycoside hydrolases based on their sequence....... In the present study we further developed the method Peptide Pattern Recognition to an automatic approach not only to find all genes encoding glycoside hydrolases and lytic polysaccharide monooxygenases in fungal genomes but also to predict the function of the genes. The functional annotation is an important...

  20. Epidemic typhus.

    Science.gov (United States)

    Bechah, Yassina; Capo, Christian; Mege, Jean-Louis; Raoult, Didier

    2008-07-01

    Epidemic typhus is transmitted to human beings by the body louse Pediculus humanus corporis. The disease is still considered a major threat by public-health authorities, despite the efficacy of antibiotics, because poor sanitary conditions are conducive to louse proliferation. Until recently, Rickettsia prowazekii, the causal agent, was thought to be confined to human beings and their body lice. Since 1975, R prowazekii infection in human beings has been related to contact with the flying squirrel Glaucomys volans in the USA. Moreover, Brill-Zinsser disease, a relapsed form of epidemic typhus that appears as sporadic cases many years after the initial infection, is unrelated to louse infestation. Stress or a waning immune system are likely to reactivate this earlier persistent infection, which could be the source of new epidemics when conditions facilitate louse infestation. Finally, R prowazekii is a potential category B bioterrorism agent, because it is stable in dried louse faeces and can be transmitted through aerosols. An increased understanding of the pathogenesis of epidemic typhus may be useful for protection against this bacterial threat.

  1. Fungal Endocarditis.

    Science.gov (United States)

    Yuan, Shi-Min

    2016-01-01

    Fungal endocarditis is a rare and fatal condition. The Candida and Aspergillus species are the two most common etiologic fungi found responsible for fungal endocarditis. Fever and changing heart murmur are the most common clinical manifestations. Some patients may have a fever of unknown origin as the onset symptom. The diagnosis of fungal endocarditis is challenging, and diagnosis of prosthetic valve fungal endocarditis is extremely difficult. The optimum antifungal therapy still remains debatable. Treating Candida endocarditis can be difficult because the Candida species can form biofilms on native and prosthetic heart valves. Combined treatment appears superior to monotherapy. Combination of antifungal therapy and surgical debridement might bring about better prognosis.

  2. Decay extent evaluation of wood degraded by a fungal community using NIRS: application for ecological engineering structures used for natural hazard mitigation

    Science.gov (United States)

    Baptiste Barré, Jean; Bourrier, Franck; Bertrand, David; Rey, Freddy

    2015-04-01

    Ecological engineering corresponds to the design of efficient solutions for protection against natural hazards such as shallow landslides and soil erosion. In particular, bioengineering structures can be composed of a living part, made of plants, cuttings or seeds, and an inert part, a timber logs structure. As wood is not treated by preservatives, fungal degradation can occur from the start of the construction. It results in wood strength loss, which practitioners try to evaluate with non-destructive tools (NDT). Classical NDT are mainly based on density measurements. However, the fungal activity reduces the mechanical properties (modulus of elasticity - MOE) well before well before a density change could be measured. In this context, it would be useful to provide a tool for assessing the residual mechanical strength at different decay stages due to a fungal community. Near-infrared spectroscopy (NIRS) can be used for that purpose, as it can allow evaluating wood mechanical properties as well as wood chemical changes due to brown and white rots. We monitored 160 silver fir samples (30x30x6000mm) from green state to different levels of decay. The degradation process took place in a greenhouse and samples were inoculated with silver fir decayed debris in order to accelerate the process. For each sample, we calculated the normalized bending modulus of elasticity loss (Dw moe) and defined it as decay extent. Near infrared spectra collected from both green and decayed ground samples were corrected by the subtraction of baseline offset. Spectra of green samples were averaged into one mean spectrum and decayed spectra were subtracted from the mean spectrum to calculate the absorption loss. Partial least square regression (PLSR) has been performed between the normalized MOE loss Dw moe (0 wood decay extent in the context of ecological engineering structures used for natural hazard mitigation.

  3. Evolution of Chemical Diversity in a Group of Non-Reduced Polyketide Gene Clusters: Using Phylogenetics to Inform the Search for Novel Fungal Natural Products

    Directory of Open Access Journals (Sweden)

    Kurt Throckmorton

    2015-09-01

    Full Text Available Fungal polyketides are a diverse class of natural products, or secondary metabolites (SMs, with a wide range of bioactivities often associated with toxicity. Here, we focus on a group of non-reducing polyketide synthases (NR-PKSs in the fungal phylum Ascomycota that lack a thioesterase domain for product release, group V. Although widespread in ascomycete taxa, this group of NR-PKSs is notably absent in the mycotoxigenic genus Fusarium and, surprisingly, found in genera not known for their secondary metabolite production (e.g., the mycorrhizal genus Oidiodendron, the powdery mildew genus Blumeria, and the causative agent of white-nose syndrome in bats, Pseudogymnoascus destructans. This group of NR-PKSs, in association with the other enzymes encoded by their gene clusters, produces a variety of different chemical classes including naphthacenediones, anthraquinones, benzophenones, grisandienes, and diphenyl ethers. We discuss the modification of and transitions between these chemical classes, the requisite enzymes, and the evolution of the SM gene clusters that encode them. Integrating this information, we predict the likely products of related but uncharacterized SM clusters, and we speculate upon the utility of these classes of SMs as virulence factors or chemical defenses to various plant, animal, and insect pathogens, as well as mutualistic fungi.

  4. Epidemic Survivability: Characterizing Networks Under Epidemic-like Failure Propagation Scenarios

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi

    2013-01-01

    Epidemics theory has been used in different contexts in order to describe the propagation of diseases, human interactions or natural phenomena. In computer science, virus spreading has been also characterized using epidemic models. Although in the past the use of epidemic models...... in telecommunication networks has not been extensively considered, nowadays, with the increasing computation capacity and complexity of operating systems of modern network devices (routers, switches, etc.), the study of possible epidemic-like failure scenarios must be taken into account. When epidemics occur......, such as in other multiple failure scenarios, identifying the level of vulnerability offered by a network is one of the main challenges. In this paper, we present epidemic survivability, a new network measure that describes the vulnerability of each node of a network under a specific epidemic intensity. Moreover...

  5. Root Fungal Endophytes Enhance Heavy-Metal Stress Tolerance of Clethra barbinervis Growing Naturally at Mining Sites via Growth Enhancement, Promotion of Nutrient Uptake and Decrease of Heavy-Metal Concentration.

    Directory of Open Access Journals (Sweden)

    Keiko Yamaji

    Full Text Available Clethra barbinervis Sieb. et Zucc. is a tree species that grows naturally at several mine sites and seems to be tolerant of high concentrations of heavy metals, such as Cu, Zn, and Pb. The purpose of this study is to clarify the mechanism(s underlying this species' ability to tolerate the sites' severe heavy-metal pollution by considering C. barbinervis interaction with root fungal endophytes. We measured the heavy metal concentrations of root-zone soil, leaves, branches, and fine roots collected from mature C. barbinervis at Hitachi mine. We isolated fungal endophytes from surface-sterilized root segments, and we examined the growth, and heavy metal and nutrient absorption of C. barbinervis seedlings growing in sterilized mine soil with or without root fungal endophytes. Field analyses showed that C. barbinervis contained considerably high amounts of Cu, Zn, and Pb in fine roots and Zn in leaves. The fungi, Phialocephala fortinii, Rhizodermea veluwensis, and Rhizoscyphus sp. were frequently isolated as dominant fungal endophyte species. Inoculation of these root fungal endophytes to C. barbinervis seedlings growing in sterilized mine soil indicated that these fungi significantly enhanced the growth of C. barbinervis seedlings, increased K uptake in shoots and reduced the concentrations of Cu, Ni, Zn, Cd, and Pb in roots. Without root fungal endophytes, C. barbinervis could hardly grow under the heavy-metal contaminated condition, showing chlorosis, a symptom of heavy-metal toxicity. Our results indicate that the tree C. barbinervis can tolerate high heavy-metal concentrations due to the support of root fungal endophytes including P. fortinii, R. veluwensis, and Rhizoscyphus sp. via growth enhancement, K uptake promotion and decrease of heavy metal concentrations.

  6. Multiple Introduction and Naturally Occuring Drug Resistance of HCV among HIV-Infected Intravenous Drug Users in Yunnan: An Origin of China's HIV/HCV Epidemics.

    Directory of Open Access Journals (Sweden)

    Min Chen

    Full Text Available The human immunodeficiency virus 1 (HIV-1 epidemic in China historically stemmed from intravenous drug users (IDUs in Yunnan. Due to a shared transmission route, hepatitis C virus (HCV/HIV-1 co-infection is common. Here, we investigated HCV genetic characteristics and baseline drug resistance among HIV-infected IDUs in Yunnan.Blood samples of 432 HIV-1/HCV co-infected IDUs were collected from January to June 2014 in six prefectures of Yunnan Province. Partial E1E2 and NS5B genes were sequenced. Phylogenetic, evolutionary and genotypic drug resistance analyses were performed.Among the 293 specimens successfully genotyped, seven subtypes were identified, including subtypes 3b (37.9%, 111/293, 3a (21.8%, 64/293, 6n (14.0%, 41/293, 1b (10.6%, 31/293, 1a (8.2%, 24/293, 6a (5.1%, 15/293 and 6u (2.4%, 7/293. The distribution of HCV subtypes was mostly related to geographic location. Subtypes 3b, 3a, and 6n were detected in all six prefectures, however, the other four subtypes were detected only in parts of the six prefectures. Phylogeographic analyses indicated that 6n, 1a and 6u originated in the western prefecture (Dehong and spread eastward and showed genetic relatedness with those detected in Burmese. However, 6a originated in the southeast prefectures (Honghe and Wenshan bordering Vietnam and was transmitted westward. These subtypes exhibited different evolutionary rates (between 4.35×10-4 and 2.38×10-3 substitutions site-1 year-1 and times of most recent common ancestor (tMRCA, between 1790.3 and 1994.6, suggesting that HCV was multiply introduced into Yunnan. Naturally occurring resistance-associated mutations (C316N, A421V, C445F, I482L, V494A, and V499A to NS5B polymerase inhibitors were detected in direct-acting antivirals (DAAs-naïve IDUs.This work reveals the temporal-spatial distribution of HCV subtypes and baseline HCV drug resistance among HIV-infected IDUs in Yunnan. The findings enhance our understanding of the characteristics and

  7. Predicting extinction rates in stochastic epidemic models

    International Nuclear Information System (INIS)

    Schwartz, Ira B; Billings, Lora; Dykman, Mark; Landsman, Alexandra

    2009-01-01

    We investigate the stochastic extinction processes in a class of epidemic models. Motivated by the process of natural disease extinction in epidemics, we examine the rate of extinction as a function of disease spread. We show that the effective entropic barrier for extinction in a susceptible–infected–susceptible epidemic model displays scaling with the distance to the bifurcation point, with an unusual critical exponent. We make a direct comparison between predictions and numerical simulations. We also consider the effect of non-Gaussian vaccine schedules, and show numerically how the extinction process may be enhanced when the vaccine schedules are Poisson distributed

  8. Modeling Epidemic Network Failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    This paper presents the implementation of a failure propagation model for transport networks when multiple failures occur resulting in an epidemic. We model the Susceptible Infected Disabled (SID) epidemic model and validate it by comparing it to analytical solutions. Furthermore, we evaluate...... the SID model’s behavior and impact on the network performance, as well as the severity of the infection spreading. The simulations are carried out in OPNET Modeler. The model provides an important input to epidemic connection recovery mechanisms, and can due to its flexibility and versatility be used...... to evaluate multiple epidemic scenarios in various network types....

  9. Seed treatments to control seedborne fungal pathogens of vegetable crops.

    Science.gov (United States)

    Mancini, Valeria; Romanazzi, Gianfranco

    2014-06-01

    Vegetable crops are frequently infected by fungal pathogens, which can include seedborne fungi. In such cases, the pathogen is already present within or on the seed surface, and can thus cause seed rot and seedling damping-off. Treatment of vegetable seeds has been shown to prevent plant disease epidemics caused by seedborne fungal pathogens. Furthermore, seed treatments can be useful in reducing the amounts of pesticides required to manage a disease, because effective seed treatments can eliminate the need for foliar application of fungicides later in the season. Although the application of fungicides is almost always effective, their non-target environmental impact and the development of pathogen resistance have led to the search for alternative methods, especially in the past few years. Physical treatments that have already been used in the past and treatments with biopesticides, such as plant extracts, natural compounds and biocontrol agents, have proved to be effective in controlling seedborne pathogens. These have been applied alone or in combination, and they are widely used owing to their broad spectrum in terms of disease control and production yield. In this review, the effectiveness of different seed treatments against the main seedborne pathogens of some important vegetable crops is critically discussed. © 2013 Society of Chemical Industry.

  10. The Interaction of Risk Network Structures and Virus Natural History in the Non-spreading of HIV Among People Who Inject Drugs in the Early Stages of the Epidemic.

    Science.gov (United States)

    Dombrowski, Kirk; Khan, Bilal; Habecker, Patrick; Hagan, Holly; Friedman, Samuel R; Saad, Mohamed

    2017-04-01

    This article explores how social network dynamics may have reduced the spread of HIV-1 infection among people who inject drugs during the early years of the epidemic. Stochastic, discrete event, agent-based simulations are used to test whether a "firewall effect" can arise out of self-organizing processes at the actor level, and whether such an effect can account for stable HIV prevalence rates below population saturation. Repeated simulation experiments show that, in the presence of recurring, acute, and highly infectious outbreaks, micro-network structures combine with the HIV virus's natural history to reduce the spread of the disease. These results indicate that network factors likely played a significant role in the prevention of HIV infection within injection risk networks during periods of peak prevalence. They also suggest that social forces that disturb network connections may diminish the natural firewall effect and result in higher rates of HIV.

  11. Configuring the autism epidemic

    DEFF Research Database (Denmark)

    Seeberg, Jens; Christensen, Fie Lund Lindegaard

    2017-01-01

    Autism has been described as an epidemic, but this claim is contested and may point to an awareness epidemic, i.e. changes in the definition of what autism is and more attention being invested in diagnosis leading to a rise in registered cases. The sex ratio of children diagnosed with autism...... is skewed in favour of boys, and girls with autism tend to be diagnosed much later than boys. Building and further developing the notion of ‘configuration’ of epidemics, this article explores the configuration of autism in Denmark, with a particular focus on the health system and social support to families...... with children diagnosed with autism, seen from a parental perspective. The article points to diagnostic dynamics that contribute to explaining why girls with autism are not diagnosed as easily as boys. We unfold these dynamics through the analysis of a case of a Danish family with autism....

  12. Optimal Fungal Space Searching Algorithms.

    Science.gov (United States)

    Asenova, Elitsa; Lin, Hsin-Yu; Fu, Eileen; Nicolau, Dan V; Nicolau, Dan V

    2016-10-01

    Previous experiments have shown that fungi use an efficient natural algorithm for searching the space available for their growth in micro-confined networks, e.g., mazes. This natural "master" algorithm, which comprises two "slave" sub-algorithms, i.e., collision-induced branching and directional memory, has been shown to be more efficient than alternatives, with one, or the other, or both sub-algorithms turned off. In contrast, the present contribution compares the performance of the fungal natural algorithm against several standard artificial homologues. It was found that the space-searching fungal algorithm consistently outperforms uninformed algorithms, such as Depth-First-Search (DFS). Furthermore, while the natural algorithm is inferior to informed ones, such as A*, this under-performance does not importantly increase with the increase of the size of the maze. These findings suggest that a systematic effort of harvesting the natural space searching algorithms used by microorganisms is warranted and possibly overdue. These natural algorithms, if efficient, can be reverse-engineered for graph and tree search strategies.

  13. Global HIV/AIDS Epidemic

    Science.gov (United States)

    ... Policy The Global HIV/AIDS Epidemic The Global HIV/AIDS Epidemic Published: Nov 29, 2017 Facebook Twitter ... 2001-FY 2018 Request The Global Response to HIV/AIDS International efforts to combat HIV began in ...

  14. Networked SIS Epidemics With Awareness

    KAUST Repository

    Paarporn, Keith; Eksin, Ceyhun; Weitz, Joshua S.; Shamma, Jeff S.

    2017-01-01

    We study a susceptible-infected-susceptible epidemic process over a static contact network where the nodes have partial information about the epidemic state. They react by limiting their interactions with their neighbors when they believe

  15. epidemic teach us?

    African Journals Online (AJOL)

    frequently brings shame, fear and guilt: dealing with this for some will begin a process of .... 'AZT treatment will have a limited effect on the epidemic, as we are targeting ... others to make the decisions that control my life. It is ironic that a society ...

  16. The Obesity Epidemic

    Centers for Disease Control (CDC) Podcasts

    2011-07-18

    Learn about obesity and the community initiatives taking place to prevent and reduce this epidemic.  Created: 7/18/2011 by National Center for Chronic Disease Prevention and Health Promotion, Division of Nutrition, Physical Activity and Obesity.   Date Released: 7/18/2011.

  17. Kanpur epidemic: Time course

    Indian Academy of Sciences (India)

    The first peak was related to water contamination which began in December 1990. The second peak was related to failure of municipal authorities to chlorinate water during the 2nd week of February 1991. The epidemic came under control quickly after water contamination was controlled, providing confirmation for role of ...

  18. Trauma - the malignant epidemic

    African Journals Online (AJOL)

    national problem and the term 'malignant epidemic' is more applicable. These two ... In 1984 it stood at just over 400 000 per annum and today the figure is close to ... breadwinner, loss of productivity, expenses of rehabilitation and care of the ...

  19. Cyber Epidemic Models with Dependences

    OpenAIRE

    Xu, Maochao; Da, Gaofeng; Xu, Shouhuai

    2016-01-01

    Studying models of cyber epidemics over arbitrary complex networks can deepen our understanding of cyber security from a whole-system perspective. In this paper, we initiate the investigation of cyber epidemic models that accommodate the {\\em dependences} between the cyber attack events. Due to the notorious difficulty in dealing with such dependences, essentially all existing cyber epidemic models have assumed them away. Specifically, we introduce the idea of Copulas into cyber epidemic mode...

  20. Hepatitis E epidemics in India

    Indian Academy of Sciences (India)

    The first well recorded epidemic was in 1955-56 here in Delhi with nearly 30000 cases. Large outbreaks occurred in 1978 in Kashmir. My interest in this disease began in 1991 during investigations into a large epidemic of hepatitis E in Kanpur that my mentor, later Prof SR Naik, and I undertook. I will use this epidemic as an ...

  1. Fungal Genomics Program

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor

    2012-03-12

    The JGI Fungal Genomics Program aims to scale up sequencing and analysis of fungal genomes to explore the diversity of fungi important for energy and the environment, and to promote functional studies on a system level. Combining new sequencing technologies and comparative genomics tools, JGI is now leading the world in fungal genome sequencing and analysis. Over 120 sequenced fungal genomes with analytical tools are available via MycoCosm (www.jgi.doe.gov/fungi), a web-portal for fungal biologists. Our model of interacting with user communities, unique among other sequencing centers, helps organize these communities, improves genome annotation and analysis work, and facilitates new larger-scale genomic projects. This resulted in 20 high-profile papers published in 2011 alone and contributing to the Genomics Encyclopedia of Fungi, which targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts). Our next grand challenges include larger scale exploration of fungal diversity (1000 fungal genomes), developing molecular tools for DOE-relevant model organisms, and analysis of complex systems and metagenomes.

  2. Epidemics on interconnected networks

    Science.gov (United States)

    Dickison, Mark; Havlin, S.; Stanley, H. E.

    2012-06-01

    Populations are seldom completely isolated from their environment. Individuals in a particular geographic or social region may be considered a distinct network due to strong local ties but will also interact with individuals in other networks. We study the susceptible-infected-recovered process on interconnected network systems and find two distinct regimes. In strongly coupled network systems, epidemics occur simultaneously across the entire system at a critical infection strength βc, below which the disease does not spread. In contrast, in weakly coupled network systems, a mixed phase exists below βc of the coupled network system, where an epidemic occurs in one network but does not spread to the coupled network. We derive an expression for the network and disease parameters that allow this mixed phase and verify it numerically. Public health implications of communities comprising these two classes of network systems are also mentioned.

  3. (Epidemic of bacillary dysentery)

    Energy Technology Data Exchange (ETDEWEB)

    Auger, P.; Pouliot, B.; De Grace, M.; Milot, C.; Lafortune, M.; Bergeron, Z.

    1981-10-01

    An outbreak of bacillary dysentery in 1978 affecting 928 persons, most of whom were living in the village of St-Jacques, PQ, is described. An epidemiologic study suggested the water supply as the source of the infection, and it was established that the water carried by the municipal aqueduct was contaminated by feces containing the causal agent, Shigella sonnei. This epidemic, the largest mentioned in he Canadian medical literature, demonstrates how contagious this infection is.

  4. Fungal Skin Infections

    Science.gov (United States)

    ... Abbreviations Weights & Measures ENGLISH View Professional English Deutsch Japanese Espaniol Find information on medical topics, symptoms, drugs, ... touching the infected area. Diagnosis Skin scrapings or cultures Doctors may suspect a fungal infection when they ...

  5. JGI Fungal Genomics Program

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor V.

    2011-03-14

    Genomes of energy and environment fungi are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). Its key project, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts), and explores fungal diversity by means of genome sequencing and analysis. Over 50 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such 'parts' suggested by comparative genomics and functional analysis in these areas are presented here

  6. Fungal symbiosis unearthed

    Science.gov (United States)

    Daniel Cullen

    2008-01-01

    Associations between plant roots and fungi are a feature of many terrestrial ecosystems. The genome sequence of a prominent fungal partner opens new avenues for studying such mycorrhizal interactions....

  7. High prevalence of a fungal prion

    NARCIS (Netherlands)

    Debets, A.J.M.; Dalstra, H.J.P.; Slakhorst, S.M.; Koopmanschap-Memelink, A.B.; Hoekstra, R.F.; Saupe, S.J.

    2012-01-01

    Prions are infectious proteins that cause fatal diseases in mammals. Prions have also been found in fungi, but studies on their role in nature are scarce. The proposed biological function of fungal prions is debated and varies from detrimental to benign or even beneficial. [Het-s] is a prion of the

  8. Epidemics spread in heterogeneous populations

    Science.gov (United States)

    Capała, Karol; Dybiec, Bartłomiej

    2017-05-01

    Individuals building populations are subject to variability. This variability affects progress of epidemic outbreaks, because individuals tend to be more or less resistant. Individuals also differ with respect to their recovery rate. Here, properties of the SIR model in inhomogeneous populations are studied. It is shown that a small change in model's parameters, e.g. recovery or infection rate, can substantially change properties of final states which is especially well-visible in distributions of the epidemic size. In addition to the epidemic size and radii distributions, the paper explores first passage time properties of epidemic outbreaks.

  9. Fungal endophytes of sorghum in Burkina Faso

    DEFF Research Database (Denmark)

    Zida, E P; Thio, I G; Néya, B J

    2014-01-01

    A survey was conducted to assess the natural occurrence and distribution of fungal endophytes in sorghum in relation to plant performance in two distinct agro-ecological zones in Burkina Faso. Sorghum farm-saved seeds were sown in 48 farmers’ fields in Sahelian and North Sudanian zones to produce...... sorghum plants. In each field, leaf samples were collected from five well-developed (performing) and five less-developed (non-performing) plants at 3-5 leaf stage, while at plant maturity leaf, stem and root samples were collected from the same plants and fungal endophytes were isolated. A total of 39...... fungal species belonging to 25 genera were isolated. The most represented genera included Fusarium, Leptosphaeria, Curvularia, Nigrospora and Penicillium. The genera Fusarium and Penicillium occurred significantly higher in performing plants as compared to non-performing plants while the genera...

  10. Fungal endophytes: modifiers of plant disease.

    Science.gov (United States)

    Busby, Posy E; Ridout, Mary; Newcombe, George

    2016-04-01

    Many recent studies have demonstrated that non-pathogenic fungi within plant microbiomes, i.e., endophytes ("endo" = within, "phyte" = plant), can significantly modify the expression of host plant disease. The rapid pace of advancement in endophyte ecology warrants a pause to synthesize our understanding of endophyte disease modification and to discuss future research directions. We reviewed recent literature on fungal endophyte disease modification, and here report on several emergent themes: (1) Fungal endophyte effects on plant disease span the full spectrum from pathogen antagonism to pathogen facilitation, with pathogen antagonism most commonly reported. (2) Agricultural plant pathosystems are the focus of research on endophyte disease modification. (3) A taxonomically diverse group of fungal endophytes can influence plant disease severity. And (4) Fungal endophyte effects on plant disease severity are context-dependent. Our review highlights the importance of fungal endophytes for plant disease across a broad range of plant pathosystems, yet simultaneously reveals that complexity within plant microbiomes presents a significant challenge to disentangling the biotic environmental factors affecting plant disease severity. Manipulative studies integrating eco-evolutionary approaches with emerging molecular tools will be poised to elucidate the functional importance of endophytes in natural plant pathosystems that are fundamental to biodiversity and conservation.

  11. Phylogenetic analysis of fungal ABC transporters.

    Science.gov (United States)

    Kovalchuk, Andriy; Driessen, Arnold J M

    2010-03-16

    The superfamily of ABC proteins is among the largest known in nature. Its members are mainly, but not exclusively, involved in the transport of a broad range of substrates across biological membranes. Many contribute to multidrug resistance in microbial pathogens and cancer cells. The diversity of ABC proteins in fungi is comparable with those in multicellular animals, but so far fungal ABC proteins have barely been studied. We performed a phylogenetic analysis of the ABC proteins extracted from the genomes of 27 fungal species from 18 orders representing 5 fungal phyla thereby covering the most important groups. Our analysis demonstrated that some of the subfamilies of ABC proteins remained highly conserved in fungi, while others have undergone a remarkable group-specific diversification. Members of the various fungal phyla also differed significantly in the number of ABC proteins found in their genomes, which is especially reduced in the yeast S. cerevisiae and S. pombe. Data obtained during our analysis should contribute to a better understanding of the diversity of the fungal ABC proteins and provide important clues about their possible biological functions.

  12. Epidemic modeling in complex realities.

    Science.gov (United States)

    Colizza, Vittoria; Barthélemy, Marc; Barrat, Alain; Vespignani, Alessandro

    2007-04-01

    In our global world, the increasing complexity of social relations and transport infrastructures are key factors in the spread of epidemics. In recent years, the increasing availability of computer power has enabled both to obtain reliable data allowing one to quantify the complexity of the networks on which epidemics may propagate and to envision computational tools able to tackle the analysis of such propagation phenomena. These advances have put in evidence the limits of homogeneous assumptions and simple spatial diffusion approaches, and stimulated the inclusion of complex features and heterogeneities relevant in the description of epidemic diffusion. In this paper, we review recent progresses that integrate complex systems and networks analysis with epidemic modelling and focus on the impact of the various complex features of real systems on the dynamics of epidemic spreading.

  13. The epidemic of methylisothiazolinone

    DEFF Research Database (Denmark)

    Schwensen, Jakob F; Uter, Wolfgang; Bruze, Magnus

    2017-01-01

    BACKGROUND: The use of methylisothiazolinone (MI) in cosmetic products has caused an unprecedented epidemic of MI contact allergy. Current data concerning exposures at a European level are required. OBJECTIVES: To describe demographics and MI exposures for European patients with MI contact allergy....... METHODS: Eleven European dermatology departments from eight European countries prospectively collected data between 1 May and 31 October 2015 among consecutive patients who had positive patch test reactions to MI (2000 ppm aq.). RESULTS: A total of 6.0% (205/3434; range 2.6-13.0%) of patients had positive...... patch test reactions to MI. Dermatitis most frequently affected the hands (43.4%), face (32.7%), arms (14.6%), and eyelids (11.7%); 12.7% had widespread dermatitis. For 72.7% (149/205), MI contact allergy was currently relevant mainly because of exposure to cosmetic products (83.2%; 124...

  14. Fungal genomics beyond Saccharomyces cerevisiae?

    DEFF Research Database (Denmark)

    Hofmann, Gerald; Mcintyre, Mhairi; Nielsen, Jens

    2003-01-01

    Fungi are used extensively in both fundamental research and industrial applications. Saccharomyces cerevisiae has been the model organism for fungal research for many years, particularly in functional genomics. However, considering the diversity within the fungal kingdom, it is obvious...

  15. Epidemic spreading on random surfer networks with infected avoidance strategy

    Science.gov (United States)

    Feng, Yun; Ding, Li; Huang, Yun-Han; Guan, Zhi-Hong

    2016-12-01

    In this paper, we study epidemic spreading on random surfer networks with infected avoidance (IA) strategy. In particular, we consider that susceptible individuals’ moving direction angles are affected by the current location information received from infected individuals through a directed information network. The model is mainly analyzed by discrete-time numerical simulations. The results indicate that the IA strategy can restrain epidemic spreading effectively. However, when long-distance jumps of individuals exist, the IA strategy’s effectiveness on restraining epidemic spreading is heavily reduced. Finally, it is found that the influence of the noises from information transferring process on epidemic spreading is indistinctive. Project supported in part by the National Natural Science Foundation of China (Grant Nos. 61403284, 61272114, 61673303, and 61672112) and the Marine Renewable Energy Special Fund Project of the State Oceanic Administration of China (Grant No. GHME2013JS01).

  16. Fungal prostatitis: an update.

    Science.gov (United States)

    Mayayo, Emilio; Fernández-Silva, Fabiola

    2014-06-01

    Prostate pathology is a daily occurrence in urological and general medical consultations. Besides hyperplasia and neoplastic pathology, other processes, such as infectious ones, are also documented. Their etiology is diverse and varied. Within the infectious prostatic processes, fungi can also be a specific cause of prostatitis. Fungal prostatitis often appears in patients with impaired immunity and can also be rarely found in healthy patients. It can result from a disseminated infection, but it can also be localized. Fungal prostatitis is a nonspecific and harmless process. Diagnosis is commonly made by fine needle aspiration cytology or by biopsy. A number of fungi can be involved. Although there are not many reported cases, they are becoming more frequent, in particular in patients with some degree of immunodeficiency or those who live in areas where specific fungi are endemic or in visitors of those areas. We present a comprehensive review of the various forms of fungal prostatitis, and we describe the morphological characteristics of the fungi more frequently reported as causes of fungal prostatitis. We also report our own experience, aiming to alert physicians, urologists and pathologists of these particular infections.

  17. Fungal Wound Infection

    Centers for Disease Control (CDC) Podcasts

    2016-01-28

    Dr. David Tribble, acting director of the infectious disease clinical research program at Uniformed Services University of the Health Sciences, discusses fungal wound infections after combat trauma.  Created: 1/28/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 1/28/2016.

  18. The Fungal Kingdom

    NARCIS (Netherlands)

    Heitman, Joseph; Howlett, B.J.; Crous, P.W.; Stukenbrock, E.H.; James, T.Y.; Gow, N.A.R.

    2017-01-01

    Fungi research and knowledge grew rapidly following recent advances in genetics and genomics. This book synthesizes new knowledge with existing information to stimulate new scientific questions and propel fungal scientists on to the next stages of research. This book is a comprehensive guide on

  19. Identification & Characterization of Fungal Ice Nucleation Proteins

    Science.gov (United States)

    Scheel, Jan Frederik; Kunert, Anna Theresa; Kampf, Christopher Johannes; Mauri, Sergio; Weidner, Tobias; Pöschl, Ulrich; Fröhlich-Nowoisky, Janine

    2016-04-01

    Freezing of water at relatively warm subfreezing temperatures is dependent on ice nucleation catalysis facilitated by ice nuclei (IN). These IN can be of various origins and although extensive research was done and progress was achieved, the nature and mechanisms leading to an effective IN are to date still poorly understood. Some of the most important processes of our geosphere like the water cycle are highly dependent on effective ice nucleation at temperatures between -2°C - -8°C, a temperature range which is almost exclusively covered by biological IN (BioIN). BioIN are usually macromolecular structures of biological polymers. Sugars as well as proteins have been reported to serve as IN and the best characterized BioIN are ice nucleation proteins (IN-P) from gram negative bacteria. Fungal strains from Fusarium spp. were described to be effective IN at subfreezing temperatures up to -2°C already 25 years ago and more and more fungal species are described to serve as efficient IN. Fungal IN are also thought to be proteins or at least contain a proteinaceous compound, but to date the fungal IN-P primary structure as well as their coding genetic elements of all IN active fungi are unknown. The aim of this study is a.) to identify the proteins and their coding genetic elements from IN active fungi (F. acuminatum, F. avenaceum, M. alpina) and b.) to characterize the mechanisms by which fungal IN serve as effective IN. We designed an interdisciplinary approach using biological, analytical and physical methods to identify fungal IN-P and describe their biological, chemical, and physical properties.

  20. Impacts of clustering on interacting epidemics.

    Science.gov (United States)

    Wang, Bing; Cao, Lang; Suzuki, Hideyuki; Aihara, Kazuyuki

    2012-07-07

    Since community structures in real networks play a major role for the epidemic spread, we therefore explore two interacting diseases spreading in networks with community structures. As a network model with community structures, we propose a random clique network model composed of different orders of cliques. We further assume that each disease spreads only through one type of cliques; this assumption corresponds to the issue that two diseases spread inside communities and outside them. Considering the relationship between the susceptible-infected-recovered (SIR) model and the bond percolation theory, we apply this theory to clique random networks under the assumption that the occupation probability is clique-type dependent, which is consistent with the observation that infection rates inside a community and outside it are different, and obtain a number of statistical properties for this model. Two interacting diseases that compete the same hosts are also investigated, which leads to a natural generalization of analyzing an arbitrary number of infectious diseases. For two-disease dynamics, the clustering effect is hypersensitive to the cohesiveness and concentration of cliques; this illustrates the impacts of clustering and the composition of subgraphs in networks on epidemic behavior. The analysis of coexistence/bistability regions provides significant insight into the relationship between the network structure and the potential epidemic prevalence. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Rhodotorula Endogenous Endophthalmitis: A Novel Harbinger of the Injection Drug Epidemic in the United States

    Directory of Open Access Journals (Sweden)

    Preston M. Luong

    2017-01-01

    Full Text Available Endogenous endophthalmitis is a rare but feared infectious ocular complication of injection drug use (IDU. The recent opioid epidemic in the United States threatens to increase the incidence of this disease. We report the first case of endogenous endophthalmitis in the United States caused by the emerging fungal pathogen Rhodotorula in an injection drug user which led to no light perception vision (NLP. Worldwide experience with Rhodotorula endogenous endophthalmitis is limited, but existing cases suggest infection by this particular fungal genus has a grim prognosis.

  2. Epidemic cholera spreads like wildfire

    Science.gov (United States)

    Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

    2014-01-01

    Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks.

  3. [Epidemic parotiditis, a reportable disease].

    Science.gov (United States)

    Boverhoff, J C; Baart, J A

    2013-01-01

    Three consecutive patients with an acute swelling of one of the cheeks, were diagnosed with epidemic parotiditis. The first phase of the diagnostic procedure for an acute cheek swelling is to eliminate the possibility of odontogenic causes. When odontogenic problems have been excluded, non-dentition-related causes may be considered. An acute, progressive swelling in the preauricular area can often be attributed to an inflammation of the parotid gland, but epidemic parotiditis should also be considered. Epidemic parotiditis, or mumps, is caused by the mumps virus. Contamination occurs aerogenically. In the Netherlands, mumps vaccine is an ingredient of the governmental combined mump-measles-rubella inoculation programme. However, in recent years several small-scale parotiditis epidemics have broken out, predominantly among young, inoculated adults. Oropharyngeal mucus and blood samples are needed to diagnose the disease. Each case of the disease should be reported to the community healthcare service.

  4. Engaging 'communities': anthropological insights from the West African Ebola epidemic.

    Science.gov (United States)

    Wilkinson, A; Parker, M; Martineau, F; Leach, M

    2017-05-26

    The recent Ebola epidemic in West Africa highlights how engaging with the sociocultural dimensions of epidemics is critical to mounting an effective outbreak response. Community engagement was pivotal to ending the epidemic and will be to post-Ebola recovery, health system strengthening and future epidemic preparedness and response. Extensive literatures in the social sciences have emphasized how simple notions of community, which project solidarity onto complex hierarchies and politics, can lead to ineffective policies and unintended consequences at the local level, including doing harm to vulnerable populations. This article reflects on the nature of community engagement during the Ebola epidemic and demonstrates a disjuncture between local realities and what is being imagined in post-Ebola reports about the lessons that need to be learned for the future. We argue that to achieve stated aims of building trust and strengthening outbreak response and health systems, public health institutions need to reorientate their conceptualization of 'the community' and develop ways of working which take complex social and political relationships into account.This article is part of the themed issue 'The 2013-2016 West African Ebola epidemic: data, decision-making and disease control'. © 2017 The Authors.

  5. Fungal NRPS-dependent siderophores: From function to prediction

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Knudsen, Michael; Hansen, Frederik Teilfeldt

    2014-01-01

    discuss the function of siderophores in relation to fungal iron uptake mechanisms and their importance for coexistence with host organisms. The chemical nature of the major groups of siderophores and their regulation is described along with the function and architecture of the large multi-domain enzymes...... responsible for siderophore synthesis, namely the non-ribosomal peptide synthetases (NRPSs). Finally, we present the most recent advances in our understanding of the structural biology of fungal NRPSs and discuss opportunities for the development of a fungal NRPS prediction server...

  6. Fungal natural products targeting chronic lymphocytic leukemia

    DEFF Research Database (Denmark)

    Bladt, Tanja Thorskov; Kildgaard, Sara; Knudsen, Peter Boldsen

    2012-01-01

    Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults from the western world. No curative treatments of CLL are presently known so the treatment strategy today is primarily to prolong patient survival,1 why we have initiated new activities towards discovery of novel compounds......,3 This includes analysis of the spectroscopic data generated from LC-DAD-MS to reveal whether the active principles are either structurally known compounds or are likely to be novel compounds. This paper will illustrate our integrated discovery approaches and recent findings of anti-leukemia compounds....

  7. The worldwide obesity epidemic.

    Science.gov (United States)

    James, P T; Leach, R; Kalamara, E; Shayeghi, M

    2001-11-01

    The recent World Health Organization (WHO) agreement on the standardized classification of overweight and obese, based on body mass index (BMI), allows a comparable analysis of prevalence rates worldwide for the first time. In Asia, however, there is a demand for a more limited range for normal BMIs (i.e., 18.5 to 22.9 kg/m(2) rather than 18.5 to 24.9 kg/m(2)) because of the high prevalence of comorbidities, particularly diabetes and hypertension. In children, the International Obesity Task-Force age-, sex-, and BMI-specific cutoff points are increasingly being used. We are currently evaluating BMI data globally as part of a new millennium analysis of the Global Burden of Disease. WHO is analyzing data in terms of 20 or more principal risk factors contributing to the primary causes of disability and lost lives in the 191 countries within the WHO. The prevalence rates for overweight and obese people are different in each region, with the Middle East, Central and Eastern Europe, and North America having higher prevalence rates. In most countries, women show a greater BMI distribution with higher obesity rates than do men. Obesity is usually now associated with poverty, even in developing countries. Relatively new data suggest that abdominal obesity in adults, with its associated enhanced morbidity, occurs particularly in those who had lower birth weights and early childhood stunting. Waist measurements in nationally representative studies are scarce but will now be needed to estimate the full impact of the worldwide obesity epidemic.

  8. 50-plus years of fungal viruses

    Energy Technology Data Exchange (ETDEWEB)

    Ghabrial, Said A., E-mail: saghab00@email.uky.edu [Plant Pathology Department, University of Kentucky, Lexington, KY (United States); Castón, José R. [Department of Structure of Macromolecules, Centro Nacional Biotecnologıa/CSIC, Campus de Cantoblanco, Madrid (Spain); Jiang, Daohong [State Key Lab of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei Province (China); Nibert, Max L. [Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA (United States); Suzuki, Nobuhiro [Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama (Japan)

    2015-05-15

    Mycoviruses are widespread in all major taxa of fungi. They are transmitted intracellularly during cell division, sporogenesis, and/or cell-to-cell fusion (hyphal anastomosis), and thus their life cycles generally lack an extracellular phase. Their natural host ranges are limited to individuals within the same or closely related vegetative compatibility groups, although recent advances have established expanded experimental host ranges for some mycoviruses. Most known mycoviruses have dsRNA genomes packaged in isometric particles, but an increasing number of positive- or negative-strand ssRNA and ssDNA viruses have been isolated and characterized. Although many mycoviruses do not have marked effects on their hosts, those that reduce the virulence of their phytopathogenic fungal hosts are of considerable interest for development of novel biocontrol strategies. Mycoviruses that infect endophytic fungi and those that encode killer toxins are also of special interest. Structural analyses of mycoviruses have promoted better understanding of virus assembly, function, and evolution. - Highlights: • Historical perspective of fungal virus research. • Description, classification and diversity of fungal virus families. • Structural features of fungal virus particles. • Hypovirulence and exploitation of mycoviruses in biological control of plant pathogenic fungi.

  9. Shifts in diversification rates and host jump frequencies shaped the diversity of host range among Sclerotiniaceae fungal plant pathogens.

    Science.gov (United States)

    Navaud, Olivier; Barbacci, Adelin; Taylor, Andrew; Clarkson, John P; Raffaele, Sylvain

    2018-03-01

    The range of hosts that a parasite can infect in nature is a trait determined by its own evolutionary history and that of its potential hosts. However, knowledge on host range diversity and evolution at the family level is often lacking. Here, we investigate host range variation and diversification trends within the Sclerotiniaceae, a family of Ascomycete fungi. Using a phylogenetic framework, we associate diversification rates, the frequency of host jump events and host range variation during the evolution of this family. Variations in diversification rate during the evolution of the Sclerotiniaceae define three major macro-evolutionary regimes with contrasted proportions of species infecting a broad range of hosts. Host-parasite cophylogenetic analyses pointed towards parasite radiation on distant hosts long after host speciation (host jump or duplication events) as the dominant mode of association with plants in the Sclerotiniaceae. The intermediate macro-evolutionary regime showed a low diversification rate, high frequency of duplication events and the highest proportion of broad host range species. Our findings suggest that the emergence of broad host range fungal pathogens results largely from host jumps, as previously reported for oomycete parasites, probably combined with low speciation rates. These results have important implications for our understanding of fungal parasites evolution and are of particular relevance for the durable management of disease epidemics. © 2018 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  10. Epidemic disease decimates amphibian abundance, species diversity, and evolutionary history in the highlands of central Panama

    OpenAIRE

    Crawford, Andrew J.; Lips, Karen R.; Bermingham, Eldredge

    2010-01-01

    Amphibian populations around the world are experiencing unprecedented declines attributed to a chytrid fungal pathogen, Batrachochytrium dendrobatidis. Despite the severity of the crisis, quantitative analyses of the effects of the epidemic on amphibian abundance and diversity have been unavailable as a result of the lack of equivalent data collected before and following disease outbreak. We present a community-level assessment combining long-term field surveys and DNA barcode data describing...

  11. Epidemic optic neuropathy in Cuba. Eye findings.

    Science.gov (United States)

    Sadun, A A; Martone, J F; Muci-Mendoza, R; Reyes, L; DuBois, L; Silva, J C; Roman, G; Caballero, B

    1994-05-01

    , economic, and social changes in Cuba may have contributed to the nutritional and/or toxic compromise of mitochondrial function of an acquired nature, which led to selective retinal ganglion cell damage. We have termed this condition Cuban epidemic optic neuropathy.

  12. Symbiotic fungal associations in 'lower' land plants.

    Science.gov (United States)

    Read, D J; Ducket, J G; Francis, R; Ligron, R; Russell, A

    2000-06-29

    these plants are similar to those seen in mycorrhizal associations of ericaceous plants like Vaccinium. Cross inoculation experiments have confirmed that a typical mycorrhizal endophyte of ericaceous plants, Hymenoscyphus ericae, will form associations in liverworts which are structurally identical to those seen in nature. Again, the functional significance of these associations remains to be examined. Some members of the Jungermanniales and Metzgeriales form associations with basidiomycetous fungi. These produce intracellular coils of hyphae, which are similar to the pelotons seen in orchid mycorrhizas, which also involve basidiomycetes. The fungal associates of the autotrophic Aneura and of its heterotrophic relative Cryptothallus mirabilis have been isolated. In the latter case it has been shown that the fungal symbiont is an ectomycorrhizal associate of Betula, suggesting that the apparently obligate nature of the association between the hepatic and Betula in nature is based upon requirement for this particular heterotroph.

  13. Epidemic processes in complex networks

    Science.gov (United States)

    Pastor-Satorras, Romualdo; Castellano, Claudio; Van Mieghem, Piet; Vespignani, Alessandro

    2015-07-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The theoretical analysis of epidemic spreading in heterogeneous networks requires the development of novel analytical frameworks, and it has produced results of conceptual and practical relevance. A coherent and comprehensive review of the vast research activity concerning epidemic processes is presented, detailing the successful theoretical approaches as well as making their limits and assumptions clear. Physicists, mathematicians, epidemiologists, computer, and social scientists share a common interest in studying epidemic spreading and rely on similar models for the description of the diffusion of pathogens, knowledge, and innovation. For this reason, while focusing on the main results and the paradigmatic models in infectious disease modeling, the major results concerning generalized social contagion processes are also presented. Finally, the research activity at the forefront in the study of epidemic spreading in coevolving, coupled, and time-varying networks is reported.

  14. Environmental Factors Influencing Epidemic Cholera

    Science.gov (United States)

    Jutla, Antarpreet; Whitcombe, Elizabeth; Hasan, Nur; Haley, Bradd; Akanda, Ali; Huq, Anwar; Alam, Munir; Sack, R. Bradley; Colwell, Rita

    2013-01-01

    Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks. PMID:23897993

  15. Networked SIS Epidemics With Awareness

    KAUST Repository

    Paarporn, Keith

    2017-07-20

    We study a susceptible-infected-susceptible epidemic process over a static contact network where the nodes have partial information about the epidemic state. They react by limiting their interactions with their neighbors when they believe the epidemic is currently prevalent. A node\\'s awareness is weighted by the fraction of infected neighbors in their social network, and a global broadcast of the fraction of infected nodes in the entire network. The dynamics of the benchmark (no awareness) and awareness models are described by discrete-time Markov chains, from which mean-field approximations (MFAs) are derived. The states of the MFA are interpreted as the nodes\\' probabilities of being infected. We show a sufficient condition for the existence of a

  16. Understanding Ebola: the 2014 epidemic.

    Science.gov (United States)

    Kaner, Jolie; Schaack, Sarah

    2016-09-13

    Near the end of 2013, an outbreak of Zaire ebolavirus (EBOV) began in Guinea, subsequently spreading to neighboring Liberia and Sierra Leone. As this epidemic grew, important public health questions emerged about how and why this outbreak was so different from previous episodes. This review provides a synthetic synopsis of the 2014-15 outbreak, with the aim of understanding its unprecedented spread. We present a summary of the history of previous epidemics, describe the structure and genetics of the ebolavirus, and review our current understanding of viral vectors and the latest treatment practices. We conclude with an analysis of the public health challenges epidemic responders faced and some of the lessons that could be applied to future outbreaks of Ebola or other viruses.

  17. Epidemic spreading on interconnected networks.

    Science.gov (United States)

    Saumell-Mendiola, Anna; Serrano, M Ángeles; Boguñá, Marián

    2012-08-01

    Many real networks are not isolated from each other but form networks of networks, often interrelated in nontrivial ways. Here, we analyze an epidemic spreading process taking place on top of two interconnected complex networks. We develop a heterogeneous mean-field approach that allows us to calculate the conditions for the emergence of an endemic state. Interestingly, a global endemic state may arise in the coupled system even though the epidemics is not able to propagate on each network separately and even when the number of coupling connections is small. Our analytic results are successfully confronted against large-scale numerical simulations.

  18. Fungal biodiversity to biotechnology.

    Science.gov (United States)

    Chambergo, Felipe S; Valencia, Estela Y

    2016-03-01

    Fungal habitats include soil, water, and extreme environments. With around 100,000 fungus species already described, it is estimated that 5.1 million fungus species exist on our planet, making fungi one of the largest and most diverse kingdoms of eukaryotes. Fungi show remarkable metabolic features due to a sophisticated genomic network and are important for the production of biotechnological compounds that greatly impact our society in many ways. In this review, we present the current state of knowledge on fungal biodiversity, with special emphasis on filamentous fungi and the most recent discoveries in the field of identification and production of biotechnological compounds. More than 250 fungus species have been studied to produce these biotechnological compounds. This review focuses on three of the branches generally accepted in biotechnological applications, which have been identified by a color code: red, green, and white for pharmaceutical, agricultural, and industrial biotechnology, respectively. We also discuss future prospects for the use of filamentous fungi in biotechnology application.

  19. The narcissism epidemic is dead : Long live the narcissism epidemic

    NARCIS (Netherlands)

    Wetzel, Eunike; Brown, Anna; Hill, Patrick; Chung, J.M.H.; Robins, R.W.; Roberts, B.W.

    2017-01-01

    Are recent cohorts of college students more narcissistic than their predecessors? To address debates about the so-called “narcissism epidemic,” we used data from three cohorts of students (N1990s = 1,166; N2000s = 33,647; N2010s = 25,412) to test whether narcissism levels (overall and specific

  20. Host phenology and geography as drivers of differentiation in generalist fungal mycoparasites.

    Directory of Open Access Journals (Sweden)

    Alexandra Pintye

    Full Text Available The question as to why parasites remain generalist or become specialist is a key unresolved question in evolutionary biology. Ampelomyces spp., intracellular mycoparasites of powdery mildew fungi, which are themselves plant pathogens, are a useful model for studies of this issue. Ampelomyces is used for the biological control of mildew. Differences in mycohost phenology promote temporal isolation between sympatric Ampelomyces mycoparasites. Apple powdery mildew (APM causes spring epidemics, whereas other powdery mildew species on plants other than apple cause epidemics later in the season. This has resulted in genetic differentiation between APM and non-APM strains. It is unclear whether there is genetic differentiation between non-APM Ampelomyces lineages due to their specialization on different mycohosts. We used microsatellites to address this question and found no significant differentiation between non-APM Ampelomyces strains from different mycohosts or host plants, but strong differentiation between APM and non-APM strains. A geographical structure was revealed in both groups, with differences between European countries, demonstrating restricted dispersal at the continent scale and a high resolution for our markers. We found footprints of recombination in both groups, possibly more frequent in the APM cluster. Overall, Ampelomyces thus appears to be one of the rare genuine generalist pathogenic fungi able to parasitize multiple hosts in natural populations. It is therefore an excellent model for studying the evolution of pathogens towards a generalist rather than host-specific strategy, particularly in light of the tritrophic interaction between Ampelomyces mycoparasites, their powdery mildew fungal hosts and the mildew host plants.

  1. Genealogical evidence for epidemics of selfish genes.

    Science.gov (United States)

    Ingvarsson, Par K; Taylor, Douglas R

    2002-08-20

    Some genetic elements spread infectiously in populations by increasing their rate of genetic transmission at the expense of other genes in the genome. These so-called selfish genetic elements comprise a substantial portion of eukaryotic genomes and have long been viewed as a potent evolutionary force. Despite this view, little is known about the evolutionary history of selfish genetic elements in natural populations, or their genetic effects on other portions of the genome. Here we use nuclear and chloroplast gene genealogies in two species of Silene to show the historical pattern of selection on a well known selfish genetic element, cytoplasmic male sterility. We provide evidence that evolution of cytoplasmic male sterility has been characterized by frequent turnovers of mutations in natural populations, thus supporting an epidemic model for the evolution of selfish genes, where new mutations repeatedly arise and rapidly sweep through populations.

  2. Phytoplankton chytridiomycosis: fungal parasites of phytoplankton and their imprints on the food web dynamics

    Directory of Open Access Journals (Sweden)

    Télesphore eSIME - NGANDO

    2012-10-01

    Full Text Available Parasitism is one of the earlier and common ecological interactions in the nature, occurring in almost all environments. Microbial parasites typically are characterized by their small size, short generation time, and high rates of reproduction, with simple life cycle occurring generally within a single host. They are diverse and ubiquitous in aquatic ecosystems, comprising viruses, prokaryotes and eukaryotes. Recently, environmental 18S-rDNA surveys of microbial eukaryotes have unveiled major infecting agents in pelagic systems, consisting primarily of the fungal order of Chytridiales (chytrids. Chytrids are considered the earlier branch of the Eumycetes and produce motile, flagellated zoospores, characterized by a small size (2-6 µm and a single, posterior flagellum. The existence of these dispersal propagules includes chytrids within the so-called group of zoosporic fungi, which are particularly adapted to the plankton lifestyle where they infect a wide variety of hosts, including fishes, eggs, zooplankton, algae, and other aquatic fungi but primarily freshwater phytoplankton. Related ecological implications are huge because chytrids can killed their hosts, release substrates for microbial processes, and provide nutrient-rich particles as zoospores and short fragments of filamentous inedible hosts for the grazer food chain. Furthermore, based on the observation that phytoplankton chytridiomycosis preferentially impacts the larger size species, blooms of such species (e.g. filamentous cyanobacteria may not totally represent trophic bottlenecks. Besides, chytrid epidemics represent an important driving factor in phytoplankton seasonal successions. In this review, I summarize the knowledge on the diversity, community structure, quantitative importance, and functional roles of fungal chytrids, primarily those who are parasites of phytoplankton, and infer the ecological implications and potentials for the food web dynamics and properties.

  3. Fungal Anticancer Metabolites: Synthesis Towards Drug Discovery.

    Science.gov (United States)

    Barbero, Margherita; Artuso, Emma; Prandi, Cristina

    2018-01-01

    Fungi are a well-known and valuable source of compounds of therapeutic relevance, in particular of novel anticancer compounds. Although seldom obtainable through isolation from the natural source, the total organic synthesis still remains one of the most efficient alternatives to resupply them. Furthermore, natural product total synthesis is a valuable tool not only for discovery of new complex biologically active compounds but also for the development of innovative methodologies in enantioselective organic synthesis. We undertook an in-depth literature searching by using chemical bibliographic databases (SciFinder, Reaxys) in order to have a comprehensive insight into the wide research field. The literature has been then screened, refining the obtained results by subject terms focused on both biological activity and innovative synthetic procedures. The literature on fungal metabolites has been recently reviewed and these publications have been used as a base from which we consider the synthetic feasibility of the most promising compounds, in terms of anticancer properties and drug development. In this paper, compounds are classified according to their chemical structure. This review summarizes the anticancer potential of fungal metabolites, highlighting the role of total synthesis outlining the feasibility of innovative synthetic procedures that facilitate the development of fungal metabolites into drugs that may become a real future perspective. To our knowledge, this review is the first effort to deal with the total synthesis of these active fungi metabolites and demonstrates that total chemical synthesis is a fruitful means of yielding fungal derivatives as aided by recent technological and innovative advancements. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Current management of fungal infections.

    NARCIS (Netherlands)

    Meis, J.F.G.M.; Verweij, P.E.

    2001-01-01

    The management of superficial fungal infections differs significantly from the management of systemic fungal infections. Most superficial infections are treated with topical antifungal agents, the choice of agent being determined by the site and extent of the infection and by the causative organism,

  5. The evolution of fungal epiphytes

    NARCIS (Netherlands)

    Hongsanan, S.; Sánchez-Ramírez, S.; Crous, P.W.; Ariyawansa, H.A.; Zhao, R.L.; Hyde, K.D.

    2016-01-01

    Fungal epiphytes are a polyphyletic group found on the surface of plants, particularly on leaves, with a worldwide distribution. They belong in the phylum Ascomycota, which contains the largest known number of fungal genera. There has been little research dating the origins of the common ancestors

  6. Epidemic threshold in directed networks

    Science.gov (United States)

    Li, Cong; Wang, Huijuan; Van Mieghem, Piet

    2013-12-01

    Epidemics have so far been mostly studied in undirected networks. However, many real-world networks, such as the online social network Twitter and the world wide web, on which information, emotion, or malware spreads, are directed networks, composed of both unidirectional links and bidirectional links. We define the directionality ξ as the percentage of unidirectional links. The epidemic threshold τc for the susceptible-infected-susceptible (SIS) epidemic is lower bounded by 1/λ1 in directed networks, where λ1, also called the spectral radius, is the largest eigenvalue of the adjacency matrix. In this work, we propose two algorithms to generate directed networks with a given directionality ξ. The effect of ξ on the spectral radius λ1, principal eigenvector x1, spectral gap (λ1-λ2), and algebraic connectivity μN-1 is studied. Important findings are that the spectral radius λ1 decreases with the directionality ξ, whereas the spectral gap and the algebraic connectivity increase with the directionality ξ. The extent of the decrease of the spectral radius depends on both the degree distribution and the degree-degree correlation ρD. Hence, in directed networks, the epidemic threshold is larger and a random walk converges to its steady state faster than that in undirected networks with the same degree distribution.

  7. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination...... as an infinite-dimensional optimal controlproblem. Illustrative numerical examples are given and commented....

  8. Stochastic Processes in Epidemic Theory

    CERN Document Server

    Lefèvre, Claude; Picard, Philippe

    1990-01-01

    This collection of papers gives a representative cross-selectional view of recent developments in the field. After a survey paper by C. Lefèvre, 17 other research papers look at stochastic modeling of epidemics, both from a theoretical and a statistical point of view. Some look more specifically at a particular disease such as AIDS, malaria, schistosomiasis and diabetes.

  9. The First American Cocaine Epidemic.

    Science.gov (United States)

    Courtwright, David T.

    1991-01-01

    Discusses the wave of cocaine abuse that followed the drug's recommendation by the late nineteenth-century medical community as a cure all. Details drug addiction among ethnic and social groups at the turn of the century. Warns that drug epidemics have important social and legal consequences. Suggests legal pressure may alter the form of drug…

  10. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination wit...

  11. Epidemics in adaptive networks with community structure

    Science.gov (United States)

    Shaw, Leah; Tunc, Ilker

    2010-03-01

    Models for epidemic spread on static social networks do not account for changes in individuals' social interactions. Recent studies of adaptive networks have modeled avoidance behavior, as non-infected individuals try to avoid contact with infectives. Such models have not generally included realistic social structure. Here we study epidemic spread on an adaptive network with community structure. We model the effect of heterogeneous communities on infection levels and epidemic extinction. We also show how an epidemic can alter the community structure.

  12. Superficial fungal infections.

    Science.gov (United States)

    Schwartz, Robert A

    Superficial fungal infections arise from a pathogen that is restricted to the stratum corneum, with little or no tissue reaction. In this Seminar, three types of infection will be covered: tinea versicolor, piedra, and tinea nigra. Tinea versicolor is common worldwide and is caused by Malassezia spp, which are human saprophytes that sometimes switch from yeast to pathogenic mycelial form. Malassezia furfur, Malassezia globosa, and Malassezia sympodialis are most closely linked to tinea versicolor. White and black piedra are both common in tropical regions of the world; white piedra is also endemic in temperate climates. Black piedra is caused by Piedraia hortae; white piedra is due to pathogenic species of the Trichosporon genus. Tinea nigra is also common in tropical areas and has been confused with melanoma.

  13. Fungal keratitis: A review

    International Nuclear Information System (INIS)

    Jastaneiah, Sabah S.; Al-Rajhi, Ali A.

    2006-01-01

    Keratomycosis is a vision-threatening fungal corneal infection. The dramatic increase in the number of cases over the past three decades is attributable not only to better diagnostic recognition, improved laboratory techniques and greater awareness by the ophthalmic society as a whole, but is also due to a true increase in the incidence of keratitis related to the indiscriminate use of topical broad-spectrum antibiotics, corticosteroids and immunosuppressive drugs, as well as surgical trauma. Corneal trauma has remained the main predisposing factor over the years, though in recent years HIV-positive cases and AIDS are taking lead in certain areas. Aspergillus, Fusarium and Candida species remains the commonest 'organisms' isolated worldwide. Although the approach to this form of keratitis is similar to other types of microbial keratitis, it remains the most difficult in terms of diagnosis and management. Early recognition, prevention, prompt treatment and timely keratoplasty are crucial for a better outcome. (author)

  14. Epidemics spreading in interconnected complex networks

    International Nuclear Information System (INIS)

    Wang, Y.; Xiao, G.

    2012-01-01

    We study epidemic spreading in two interconnected complex networks. It is found that in our model the epidemic threshold of the interconnected network is always lower than that in any of the two component networks. Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. Theoretical analysis and simulation results show that, generally speaking, the epidemic size is not significantly affected by the inter-network correlation. In interdependent networks which can be viewed as a special case of interconnected networks, however, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant. -- Highlights: ► We study epidemic spreading in two interconnected complex networks. ► The epidemic threshold is lower than that in any of the two networks. And Interconnection correlation has impacts on threshold and average outbreak size. ► Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. ► We demonstrated and proved that Interconnection correlation does not affect epidemic size significantly. ► In interdependent networks, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant.

  15. Epidemics spreading in interconnected complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research (A-STAR), Singapore 138632 (Singapore); Xiao, G., E-mail: egxxiao@ntu.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2012-09-03

    We study epidemic spreading in two interconnected complex networks. It is found that in our model the epidemic threshold of the interconnected network is always lower than that in any of the two component networks. Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. Theoretical analysis and simulation results show that, generally speaking, the epidemic size is not significantly affected by the inter-network correlation. In interdependent networks which can be viewed as a special case of interconnected networks, however, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant. -- Highlights: ► We study epidemic spreading in two interconnected complex networks. ► The epidemic threshold is lower than that in any of the two networks. And Interconnection correlation has impacts on threshold and average outbreak size. ► Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. ► We demonstrated and proved that Interconnection correlation does not affect epidemic size significantly. ► In interdependent networks, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant.

  16. Biological roles of fungal carotenoids.

    Science.gov (United States)

    Avalos, Javier; Carmen Limón, M

    2015-08-01

    Carotenoids are terpenoid pigments widespread in nature, produced by bacteria, fungi, algae and plants. They are also found in animals, which usually obtain them through the diet. Carotenoids in plants provide striking yellow, orange or red colors to fruits and flowers, and play important metabolic and physiological functions, especially relevant in photosynthesis. Their functions are less clear in non-photosynthetic microorganisms. Different fungi produce diverse carotenoids, but the mutants unable to produce them do not exhibit phenotypic alterations in the laboratory, apart of lack of pigmentation. This review summarizes the current knowledge on the functional basis for carotenoid production in fungi. Different lines of evidence support a protective role of carotenoids against oxidative stress and exposure to visible light or UV irradiation. In addition, the carotenoids are intermediary products in the biosynthesis of physiologically active apocarotenoids or derived compounds. This is the case of retinal, obtained from the symmetrical oxidative cleavage of β-carotene. Retinal is the light-absorbing prosthetic group of the rhodopsins, membrane-bound photoreceptors present also in many fungal species. In Mucorales, β-carotene is an intermediary in the synthesis of trisporoids, apocarotenoid derivatives that include the sexual hormones the trisporic acids, and they are also presumably used in the synthesis of sporopollenin polymers. In conclusion, fungi have adapted their ability to produce carotenoids for different non-essential functions, related with stress tolerance or with the synthesis of physiologically active by-products.

  17. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  18. UNTANGLING THE FUNGAL NICHE: A TRAIT-BASED APPROACH

    Directory of Open Access Journals (Sweden)

    Thomas W Crowther

    2014-10-01

    Full Text Available Fungi are prominent components of most terrestrial ecosystems, both in terms of biomass and ecosystem functioning, but the hyper-diverse nature of most communities has obscured the search for unifying principles governing community organization. In particular, unlike plants and animals, observational studies provide little evidence for the existence of niche processes in structuring fungal communities at broad spatial scales. This limits our capacity to predict how communities, and their functioning, vary across landscapes. We outline how a shift in focus, from taxonomy towards functional traits, might prove to be valuable in the search for general patterns in fungal ecology. We build on theoretical advances in plant and animal ecology to provide an empirical framework for a trait-based approach in fungal community ecology. Drawing upon specific characteristics of the fungal system, we highlight the significance of drought stress and combat in structuring free-living fungal communities. We propose a conceptual model to formalize how trade-offs between stress-tolerance and combative dominance are likely to organize communities across environmental gradients. Given that the survival of a fungus in a given environment is contingent on its ability to tolerate antagonistic competitors, measuring variation in combat trait expression along environmental gradients provides a means of elucidating realized, from fundamental niche spaces. We conclude that, using a trait-based understanding of how niche processes structure fungal communities across time and space, we can ultimately link communities with ecosystem functioning. Our trait-based framework highlights fundamental uncertainties that require testing in the fungal system, given their potential to uncover general mechanisms in fungal ecology.

  19. Multiple routes transmitted epidemics on multiplex networks

    International Nuclear Information System (INIS)

    Zhao, Dawei; Li, Lixiang; Peng, Haipeng; Luo, Qun; Yang, Yixian

    2014-01-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  20. Multiple routes transmitted epidemics on multiplex networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dawei [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Shandong Provincial Key Laboratory of Computer Network, Shandong Computer Science Center, Jinan 250014 (China); Li, Lixiang [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Peng, Haipeng, E-mail: penghaipeng@bupt.edu.cn [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Luo, Qun; Yang, Yixian [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2014-02-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  1. Functional analysis of LysM effectors secreted by fungal plant pathogens

    NARCIS (Netherlands)

    Kombrink, A.

    2014-01-01

    Chitin is a homopolymer of N-acetyl-d-glucosamine (GlcNAc)that is abundantly present in nature and found as a major structural component in the fungal cell wall. In Chapter 1,the role of chitin as an important factor in the interaction between fungal pathogens

  2. Fungal biomass in pastures increases with age and reduced N input.

    NARCIS (Netherlands)

    Vries, de F.T.; Bloem, J.; Eekeren, van N.J.M.; Brussaard, L.; Hoffland, E.

    2007-01-01

    Previous studies have shown that soil fungal biomass increases towards more natural, mature systems. Shifts to a fungal-based soil food web have previously been observed with abandonment of agricultural fields and extensification of agriculture. In a previous field experiment we found increased

  3. Anaerobic fungal populations

    International Nuclear Information System (INIS)

    Brookman, J.L.; Nicholson, M.J.

    2005-01-01

    The development of molecular techniques has greatly broadened our view of microbial diversity and enabled a more complete detection and description of microbial communities. The application of these techniques provides a simple means of following community changes, for example, Ishii et al. described transient and more stable inhabitants in another dynamic microbial system, compost. Our present knowledge of anaerobic gut fungal population diversity within the gastrointestinal tract is based upon isolation, cultivation and observations in vivo. It is likely that there are many species yet to be described, some of which may be non-culturable. We have observed a distinct difference in the ease of cultivation between the different genera, for example, Caecomyes isolates are especially difficult to isolate and maintain in vitro, a feature that is likely to result in the under representation of this genera in culture-based enumerations. The anaerobic gut fungi are the only known obligately anaerobic fungi. For the majority of their life cycles, they are found tightly associated with solid digesta in the rumen and/or hindgut. They produce potent fibrolytic enzymes and grow invasively on and into the plant material they are digesting making them important contributors to fibre digestion. This close association with intestinal digesta has made it difficult to accurately determine the amount of fungal biomass present in the rumen, with Orpin suggesting 8% contribution to the total microbial biomass, whereas Rezaeian et al. more recently gave a value of approximately 20%. It is clear that the rumen microbial complement is affected by dietary changes, and that the fungi are more important in digestion in the rumens of animals fed with high-fibre diets. It seems likely that the gut fungi play an important role within the rumen as primary colonizers of plant fibre, and so we are particularly interested in being able to measure the appearance and diversity of fungi on the plant

  4. Epidemic processes in complex networks

    OpenAIRE

    Pastor Satorras, Romualdo; Castellano, Claudio; Van Mieghem, Piet; Vespignani, Alessandro

    2015-01-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The t...

  5. Hospitalized Patients and Fungal Infections

    Science.gov (United States)

    ... are mild skin rashes, but others can be deadly, like fungal pneumonia. Because of this, it’s important ... the environment. Fungi live outdoors in soil, on plants, trees, and other vegetation. They are also on ...

  6. Cancer Patients and Fungal Infections

    Science.gov (United States)

    ... are mild skin rashes, but others can be deadly, like fungal pneumonia. Because of this, it’s important ... the environment. Fungi live outdoors in soil, on plants, trees, and other vegetation. They are also on ...

  7. Fungal Fourniers Gangrene in an Immunocompromised Patient

    Directory of Open Access Journals (Sweden)

    Winston Crowell

    2016-01-01

    Full Text Available Fournier's Gangrene is a rapidly progressive necrotizing fasciitis of the groin, perianal and perineal region that is often polymicrobial in nature, often averaging 3 species of bacteria per patient. The typical infection can be due to a host of microbes, including gram positive, gram negative and anaerobic species including. Many of the causative organisms are found in the normal microbial flora of the perineum. Therefore, Fourniers is an opportunistic infection most commonly affecting the immunosuppressed. The majority of Fournier's gangrene are bacterial; however there have been cases of fungal Fournier's gangrene reported in the literature.

  8. Structural Analysis of Fungal Cerebrosides

    Directory of Open Access Journals (Sweden)

    Eliana eBarreto-Bergter

    2011-12-01

    Full Text Available Of the ceramide monohexosides (CMHs, gluco- and galactosylceramides are the main neutral glycosphingolipids expressed in fungal cells. Their structural determination is greatly dependent on the use of mass spectrometric techniques, including fast atom bombardment-mass spectrometry (FAB-MS, electrospray ionization (ESI-MS, and energy collision-induced dissociation mass spectrometry (ESI-MS/CID-MS. Nuclear magnetic resonance (NMR has also been used successfully. Such a combination of techniques, combined with classical analytical separation, such as HPTLC and column chromatography, has led to the structural elucidation of a great number of fungal CMHs. The structure of fungal CMH is conserved among fungal species and consists of a glucose or galactose residue attached to a ceramide moiety containing 9-methyl-4,8-sphingadienine with an amidic linkage to hydroxylated fatty acids, most commonly having 16 or 18 carbon atoms and unsaturation between C-3 and C-4. Along with their unique structural characteristics, fungal CMHs have a peculiar subcellular distribution and striking biological properties. Fungal cerebrosides were also characterized as antigenic molecules directly or indirectly involved in cell growth or differentiation in Schizophyllum commune, Cryptococcus neoformans, Pseudallescheria boydii, Candida albicans, Aspergillus nidulans, A.fumigatus and Colletotrichum gloeosporioides. Besides classical techniques for cerebroside (CMH analysis, we now describe new approaches, combining conventional TLC and mass spectrometry, as well as emerging technologies for subcellular localization and distribution of glycosphingolipids by SIMS and imaging MALDI TOF .

  9. Serious fungal infections in Ecuador.

    Science.gov (United States)

    Zurita, J; Denning, D W; Paz-Y-Miño, A; Solís, M B; Arias, L M

    2017-06-01

    There is a dearth of data from Ecuador on the burden of life-threatening fungal disease entities; therefore, we estimated the burden of serious fungal infections in Ecuador based on the populations at risk and available epidemiological databases and publications. A full literature search was done to identify all epidemiology papers reporting fungal infection rates. WHO, ONU-AIDS, Index Mundi, Global Asthma Report, Globocan, and national data [Instituto Nacional de Estadística y Censos (INEC), Ministerio de Salud Pública (MSP), Sociedad de Lucha Contra el Cáncer (SOLCA), Instituto Nacional de Donación y Trasplante de Órganos, Tejidos y Células (INDOT)] were reviewed. When no data existed, risk populations were used to estimate frequencies of fungal infections, using previously described methodology by LIFE. Ecuador has a variety of climates from the cold of the Andes through temperate to humid hot weather at the coast and in the Amazon basin. Ecuador has a population of 15,223,680 people and an average life expectancy of 76 years. The median estimate of the human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) population at risk for fungal disease (Ecuador is affected by serious fungal infection.

  10. Heterologous production of fungal secondary metabolites in Aspergilli

    DEFF Research Database (Denmark)

    Anyaogu, Diana Chinyere; Mortensen, Uffe Hasbro

    2015-01-01

    Fungal natural products comprise a wide range of compounds. Some are medically attractive as drugs and drug leads, some are used as food additives, while others are harmful mycotoxins. In recent years the genome sequence of several fungi has become available providing genetic information of a lar...

  11. Conservation of biodiversity in sugar pine: effects of the blister rust epidemic on genetic diversity

    Science.gov (United States)

    Constance I. Millar; Bohun B. Kinloch; Robert D. Westfall

    1992-01-01

    Genetic diversity in sugar plne will be severely reduced by the blister rust pandemic predicted within the next 50 to 75 years. We model effects of the epidemic on genetic diversity at the stand and landscape levels for both natural and artificial regeneration. In natural stands, because natural frequencies of the dominant gene (R) for resistance are low, the most...

  12. [MPOWER--strategy for fighting the global tobacco epidemic].

    Science.gov (United States)

    Kaleta, Dorota; Kozieł, Anna; Miśkiewicz, Paulina

    2009-01-01

    It is estimated that tobacco use may cause death of 5 million people in 2008, which is higher than the number of deaths attributed to tuberculosis (TB), HIV/AIDS and malaria taken together. By 2030, the number of deaths related to the tobacco epidemic could exceed annually even 8 million. Despite many difficulties, a growing number of countries undertake intensive actions aimed at tobacco control. The objective of this paper was to discuss the major objectives of the MPOWER Report issued by the World Health Organization (WHO). The MPOWER package consists a set of six key and most effective strategies for fighting the global tobacco epidemic: 1) Monitoring tobacco consumption and the effectiveness of preventive measures; 2) Protect people from tobacco smoke; 3) Offer help to quit tobacco use; 4) Warn about the dangers of tobacco; 5) Enforce bans on tobacco advertising, promotion and sponsorship; and 6) Raise taxes on tobacco. It is proven that these strategies implemented in the compatible way, effectively decreases tobacco use. In addition, MPOWER comprises epidemiological data, information on implemented tobacco control measures and their efficiency. MPOWER is the only one document of a somewhat strategic nature that is a source of information on the spread of tobacco epidemic, as well as of suggestions concerning specific actions for supporting the fight against this epidemic.

  13. Evaluation of pulmonary fungal diseases in patients with fungal rhino-sinusitis

    Directory of Open Access Journals (Sweden)

    M.Sh. Badawy

    2013-07-01

    Conclusion: Universal screening for pulmonary fungal infection especially in patients with fungal rhino sinusitis is highly recommended to treat it early, decrease morbidity and mortality of the diseases.

  14. Potential of small-molecule fungal metabolites in antiviral chemotherapy.

    Science.gov (United States)

    Roy, Biswajit G

    2017-08-01

    Various viral diseases, such as acquired immunodeficiency syndrome, influenza, and hepatitis, have emerged as leading causes of human death worldwide. Scientific endeavor since invention of DNA-dependent RNA polymerase of pox virus in 1967 resulted in better understanding of virus replication and development of various novel therapeutic strategies. Despite considerable advancement in every facet of drug discovery process, development of commercially viable, safe, and effective drugs for these viruses still remains a big challenge. Decades of intense research yielded a handful of natural and synthetic therapeutic options. But emergence of new viruses and drug-resistant viral strains had made new drug development process a never-ending battle. Small-molecule fungal metabolites due to their vast diversity, stereochemical complexity, and preapproved biocompatibility always remain an attractive source for new drug discovery. Though, exploration of therapeutic importance of fungal metabolites has started early with discovery of penicillin, recent prediction asserted that only a small percentage (5-10%) of fungal species have been identified and much less have been scientifically investigated. Therefore, exploration of new fungal metabolites, their bioassay, and subsequent mechanistic study bears huge importance in new drug discovery endeavors. Though no fungal metabolites so far approved for antiviral treatment, many of these exhibited high potential against various viral diseases. This review comprehensively discussed about antiviral activities of fungal metabolites of diverse origin against some important viral diseases. This also highlighted the mechanistic details of inhibition of viral replication along with structure-activity relationship of some common and important classes of fungal metabolites.

  15. Contact allergy epidemics and their controls

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Johansen, Jeanne Duus; Menné, Torkil

    2007-01-01

    Contact dermatitis can be severe and lead to sick leave as well as significant healthcare expenses. The aim of this review is to present the published knowledge on 6 historical epidemics of contact allergy to apply this knowledge on the prevention and control of future contact allergy epidemics. ...... to prevent contact allergy epidemics. It is essential that dermatologist, scientists, administrators, and consumers organize and structure known methods to accelerate the control of emerging contact allergens....

  16. Information content of household-stratified epidemics

    Directory of Open Access Journals (Sweden)

    T.M. Kinyanjui

    2016-09-01

    Full Text Available Household structure is a key driver of many infectious diseases, as well as a natural target for interventions such as vaccination programs. Many theoretical and conceptual advances on household-stratified epidemic models are relatively recent, but have successfully managed to increase the applicability of such models to practical problems. To be of maximum realism and hence benefit, they require parameterisation from epidemiological data, and while household-stratified final size data has been the traditional source, increasingly time-series infection data from households are becoming available. This paper is concerned with the design of studies aimed at collecting time-series epidemic data in order to maximize the amount of information available to calibrate household models. A design decision involves a trade-off between the number of households to enrol and the sampling frequency. Two commonly used epidemiological study designs are considered: cross-sectional, where different households are sampled at every time point, and cohort, where the same households are followed over the course of the study period. The search for an optimal design uses Bayesian computationally intensive methods to explore the joint parameter-design space combined with the Shannon entropy of the posteriors to estimate the amount of information in each design. For the cross-sectional design, the amount of information increases with the sampling intensity, i.e., the designs with the highest number of time points have the most information. On the other hand, the cohort design often exhibits a trade-off between the number of households sampled and the intensity of follow-up. Our results broadly support the choices made in existing epidemiological data collection studies. Prospective problem-specific use of our computational methods can bring significant benefits in guiding future study designs.

  17. Information content of household-stratified epidemics.

    Science.gov (United States)

    Kinyanjui, T M; Pellis, L; House, T

    2016-09-01

    Household structure is a key driver of many infectious diseases, as well as a natural target for interventions such as vaccination programs. Many theoretical and conceptual advances on household-stratified epidemic models are relatively recent, but have successfully managed to increase the applicability of such models to practical problems. To be of maximum realism and hence benefit, they require parameterisation from epidemiological data, and while household-stratified final size data has been the traditional source, increasingly time-series infection data from households are becoming available. This paper is concerned with the design of studies aimed at collecting time-series epidemic data in order to maximize the amount of information available to calibrate household models. A design decision involves a trade-off between the number of households to enrol and the sampling frequency. Two commonly used epidemiological study designs are considered: cross-sectional, where different households are sampled at every time point, and cohort, where the same households are followed over the course of the study period. The search for an optimal design uses Bayesian computationally intensive methods to explore the joint parameter-design space combined with the Shannon entropy of the posteriors to estimate the amount of information in each design. For the cross-sectional design, the amount of information increases with the sampling intensity, i.e., the designs with the highest number of time points have the most information. On the other hand, the cohort design often exhibits a trade-off between the number of households sampled and the intensity of follow-up. Our results broadly support the choices made in existing epidemiological data collection studies. Prospective problem-specific use of our computational methods can bring significant benefits in guiding future study designs. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Heroin epidemics, treatment and ODE modelling.

    Science.gov (United States)

    White, Emma; Comiskey, Catherine

    2007-07-01

    The UN [United Nations Office on Drugs and Crime (UNODC): World Drug Report, 2005, vol. 1: Analysis. UNODC, 2005.], EU [European Monitoring Centre for Drugs and Drug Addiction (EMCDDA): Annual Report, 2005.http://annualreport.emcdda.eu.int/en/home-en.html.] and WHO [World Health Organisation (WHO): Biregional Strategy for Harm Reduction, 2005-2009. HIV and Injecting Drug Use. WHO, 2005.] have consistently highlighted in recent years the ongoing and persistent nature of opiate and particularly heroin use on a global scale. While this is a global phenomenon, authors have emphasised the significant impact such an epidemic has on individual lives and on society. National prevalence studies have indicated the scale of the problem, but the drug-using career, typically consisting of initiation, habitual use, a treatment-relapse cycle and eventual recovery, is not well understood. This paper presents one of the first ODE models of opiate addiction, based on the principles of mathematical epidemiology. The aim of this model is to identify parameters of interest for further study, with a view to informing and assisting policy-makers in targeting prevention and treatment resources for maximum effectiveness. An epidemic threshold value, R(0), is proposed for the drug-using career. Sensitivity analysis is performed on R(0) and it is then used to examine the stability of the system. A condition under which a backward bifurcation may exist is found, as are conditions that permit the existence of one or more endemic equilibria. A key result arising from this model is that prevention is indeed better than cure.

  19. Epidemic spreading with activity-driven awareness diffusion on multiplex network.

    Science.gov (United States)

    Guo, Quantong; Lei, Yanjun; Jiang, Xin; Ma, Yifang; Huo, Guanying; Zheng, Zhiming

    2016-04-01

    There has been growing interest in exploring the interplay between epidemic spreading with human response, since it is natural for people to take various measures when they become aware of epidemics. As a proper way to describe the multiple connections among people in reality, multiplex network, a set of nodes interacting through multiple sets of edges, has attracted much attention. In this paper, to explore the coupled dynamical processes, a multiplex network with two layers is built. Specifically, the information spreading layer is a time varying network generated by the activity driven model, while the contagion layer is a static network. We extend the microscopic Markov chain approach to derive the epidemic threshold of the model. Compared with extensive Monte Carlo simulations, the method shows high accuracy for the prediction of the epidemic threshold. Besides, taking different spreading models of awareness into consideration, we explored the interplay between epidemic spreading with awareness spreading. The results show that the awareness spreading can not only enhance the epidemic threshold but also reduce the prevalence of epidemics. When the spreading of awareness is defined as susceptible-infected-susceptible model, there exists a critical value where the dynamical process on the awareness layer can control the onset of epidemics; while if it is a threshold model, the epidemic threshold emerges an abrupt transition with the local awareness ratio α approximating 0.5. Moreover, we also find that temporal changes in the topology hinder the spread of awareness which directly affect the epidemic threshold, especially when the awareness layer is threshold model. Given that the threshold model is a widely used model for social contagion, this is an important and meaningful result. Our results could also lead to interesting future research about the different time-scales of structural changes in multiplex networks.

  20. Epidemic spreading with activity-driven awareness diffusion on multiplex network

    Science.gov (United States)

    Guo, Quantong; Lei, Yanjun; Jiang, Xin; Ma, Yifang; Huo, Guanying; Zheng, Zhiming

    2016-04-01

    There has been growing interest in exploring the interplay between epidemic spreading with human response, since it is natural for people to take various measures when they become aware of epidemics. As a proper way to describe the multiple connections among people in reality, multiplex network, a set of nodes interacting through multiple sets of edges, has attracted much attention. In this paper, to explore the coupled dynamical processes, a multiplex network with two layers is built. Specifically, the information spreading layer is a time varying network generated by the activity driven model, while the contagion layer is a static network. We extend the microscopic Markov chain approach to derive the epidemic threshold of the model. Compared with extensive Monte Carlo simulations, the method shows high accuracy for the prediction of the epidemic threshold. Besides, taking different spreading models of awareness into consideration, we explored the interplay between epidemic spreading with awareness spreading. The results show that the awareness spreading can not only enhance the epidemic threshold but also reduce the prevalence of epidemics. When the spreading of awareness is defined as susceptible-infected-susceptible model, there exists a critical value where the dynamical process on the awareness layer can control the onset of epidemics; while if it is a threshold model, the epidemic threshold emerges an abrupt transition with the local awareness ratio α approximating 0.5. Moreover, we also find that temporal changes in the topology hinder the spread of awareness which directly affect the epidemic threshold, especially when the awareness layer is threshold model. Given that the threshold model is a widely used model for social contagion, this is an important and meaningful result. Our results could also lead to interesting future research about the different time-scales of structural changes in multiplex networks.

  1. Microbiological diagnostics of fungal infections

    Directory of Open Access Journals (Sweden)

    Corrado Girmenia

    2013-07-01

    Full Text Available Laboratory tests for the detection of fungal infections are easy to perform. The main obstacle to a correct diagnosis is the correlation between the laboratory findings and the clinical diagnosis. Among pediatric patients, the most common fungal pathogen is Candida. The detection of fungal colonization may be performed through the use of chromogenic culture media, which allows also the identification of Candida subspecies, from which pathogenicity depends. In neonatology, thistest often drives the decision to begin a empiric therapy; in this regard, a close cooperation between microbiologists and clinicians is highly recommended. Blood culture, if positive, is a strong confirmation of fungal infection; however, its low sensitivity results in a high percentage of false negatives, thus decreasing its reliability. Molecular diagnostics is still under evaluation, whereas the detection of some fungal antigens, such as β-D-glucan, galactomannan, mannoprotein, and cryptococcal antigen in the serum is used for adults, but still under evaluations for pediatric patients.http://dx.doi.org/10.7175/rhc.v4i1S.862

  2. Can rewiring strategy control the epidemic spreading?

    Science.gov (United States)

    Dong, Chao; Yin, Qiuju; Liu, Wenyang; Yan, Zhijun; Shi, Tianyu

    2015-11-01

    Relation existed in the social contact network can affect individuals' behaviors greatly. Considering the diversity of relation intimacy among network nodes, an epidemic propagation model is proposed by incorporating the link-breaking threshold, which is normally neglected in the rewiring strategy. The impact of rewiring strategy on the epidemic spreading in the weighted adaptive network is explored. The results show that the rewiring strategy cannot always control the epidemic prevalence, especially when the link-breaking threshold is low. Meanwhile, as well as strong links, weak links also play a significant role on epidemic spreading.

  3. Comparison of efficacy of alternative medicine with allopathy in treatment of oral fungal infection

    Directory of Open Access Journals (Sweden)

    Sahil Maghu

    2016-01-01

    The study concluded that TTO, being a natural product, is a better nontoxic modality compared to clotrimazole, in the treatment of oral fungal infection and has a promising future for its potential application in oral health products.

  4. Radiation sensitivity of fungal microflora isolated from some pharmaceutical ingredients

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, S.A. (Ain Shams Univ., Cairo (Egypt). Botany Dept.); El-Zawahry, Y.A.; Abdel All, S.S.

    1983-01-01

    The total number of fungal microflora of D-glucose, NaCl, KCl and their solutions was determined. The fungal isolates were identified as Aspergillus fumigatus. Aspergillus niger; Spicaria divaricate and Spicaria silvatica and their response to ..gamma..-radiation was determined, the most predominant isolate Asp. fumigatus was also the most irradiation resistant. The Dio and the lethal dose were determined for each isolate in a pure spore suspension as well as in the presence of the other isolates. The higher lethal dose values obtained for pure spore suspension as compared to that obtained for the natural fungal flora a D-glucose are discussed in terms of spore clumping. The activity of amylase, protease and L-asparaginase of Asp. fumigatus was examined prior to and after exposure to different doses of ..gamma..-radiation. Though all were inhibited at high doses, the effect was not as drastic as it was on cell viability.

  5. Fungal phytotoxins with potential herbicidal activity: chemical and biological characterization.

    Science.gov (United States)

    Cimmino, Alessio; Masi, Marco; Evidente, Marco; Superchi, Stefano; Evidente, Antonio

    2015-12-19

    Covering: 2007 to 2015 Fungal phytotoxins are secondary metabolites playing an important role in the induction of disease symptoms interfering with host plant physiological processes. Although fungal pathogens represent a heavy constraint for agrarian production and for forest and environmental heritage, they can also represent an ecofriendly alternative to manage weeds. Indeed, the phytotoxins produced by weed pathogenic fungi are an efficient tool to design natural, safe bioherbicides. Their use could avoid that of synthetic pesticides causing resistance in the host plants and the long term impact of residues in agricultural products with a risk to human and animal health. The isolation and structural and biological characterization of phytotoxins produced by pathogenic fungi for weeds, including parasitic plants, are described. Structure activity relationships and mode of action studies for some phytotoxins are also reported to elucidate the herbicide potential of these promising fungal metabolites.

  6. Endophytic Fungal Diversity in Medicinal Plants of Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Monnanda Somaiah Nalini

    2014-01-01

    Full Text Available Endophytes constitute an important component of microbial diversity, and in the present investigation, seven plant species with rich ethnobotanical uses representing six families were analyzed for the presence of endophytic fungi from their natural habitats during monsoon (May/June and winter (November/December seasons of 2007. Fungal endophytes were isolated from healthy plant parts such as stem, root, rhizome, and inflorescence employing standard isolation methods. One thousand five hundred and twenty-nine fungal isolates were obtained from 5200 fragments. Stem fragments harbored more endophytes (80.37% than roots (19.22%. 31 fungal taxa comprised of coelomycetes (65%, hyphomycetes (32%, and ascomycetes (3%. Fusarium, Acremonium, Colletotrichum, Chaetomium, Myrothecium, Phomopsis, and Pestalotiopsis spp. were commonly isolated. Diversity indices differed significantly between the seasons (P<0.001. Species richness was greater for monsoon isolations than winter. Host specificity was observed for few fungal endophytes. UPGMA cluster analysis grouped the endophytes into distinct clusters on the basis of genetic distance. This study is the first report on the diversity and host-specificity of endophytic fungal taxa were from the semi evergreen forest type in Talacauvery subcluster of Western Ghats.

  7. Fungal Infections in Some Economically Important Freshwater Fishes

    Directory of Open Access Journals (Sweden)

    Zafar Iqbal*, Uzma Sheikh and Rabia Mughal

    2012-06-01

    Full Text Available Aim of this study was to investigate fungal infections in four species of carps including goldfish, Carassius (C. auratus L.; silver carp, Hypophthalmichthys (H. molitrix Richardsons; rahu, Labeo (L. rohita Hamilton and Ctenopharyngodon (C. idella Valenciennes. Nine specimens of each species were studied for the presence of fungal infections. Infected fishes showed clinical signs such as fungal growth on skin, fins, eyes, eroded fins and scales, hemorrhages on body surface and abdominal distension. The specimens from infected organs of fish were inoculated on each, malt extract, Sabouraud dextrose and potato dextrose agars. The fungal colonies of white, black, green, grey and brown colors were observed in the agar plates. Slides were prepared and stained with 0.05% Trypan blue in lactophenol. C. auratus showed the highest infection rate (44.4% followed by H. molitrix and L. rohita (11.1% each. Five fungal species viz. Aspergillus (33.3%, Penicillium (22.2%, Alternaria (27.7%, Blastomyces spp (11.1% and Rhizopus (5.5% were isolated. Posterior part of the fish had significantly (P=0.05 higher (62.5% infection as compared to anterior part (37.5%. The caudal fin with 31.25% infection was the single most affected area. This study showed that most of the fungi isolated from fishes are considered as normal mycoflora, yet many fungi can cause natural infections in ponds and aquarium.

  8. The Diabetes Epidemic in Korea

    Directory of Open Access Journals (Sweden)

    Junghyun Noh

    2016-09-01

    Full Text Available Diabetes is one of the foremost public health issues worldwide that can lead to complications in many organ systems, and has become a significant cause of morbidity and mortality in Korea. According to data from the National Health Insurance Service (NHIS, about 2.7 million Koreans (8.0% aged 30 years or older had type 2 diabetes mellitus (T2DM in 2013. The prevalence of T2DM increased with age and rose from 5.6% in 2006 to 8.0% in 2013. Using data based on The Health Screening Service of the NHIS, 25% of Korean adults were reported to have prediabetes in 2013. The prevalence of an impaired fasting glucose tended to increase over time from 21.5% in 2006 to 25.0% in 2013. Even though nationwide health screening has been regularly conducted as a public service, the proportion of undiagnosed cases of diabetes was still reported to be on the higher side in the latest study. Based on the results of these epidemic studies, further actions will be needed to effectively implement lifestyle changes on a social level and increase measures for the early detection of diabetes to stem the tide of the epidemic.

  9. The Fungal Defensin Family Enlarged

    Directory of Open Access Journals (Sweden)

    Jiajia Wu

    2014-08-01

    Full Text Available Fungi are an emerging source of peptide antibiotics. With the availability of a large number of model fungal genome sequences, we can expect that more and more fungal defensin-like peptides (fDLPs will be discovered by sequence similarity search. Here, we report a total of 69 new fDLPs encoded by 63 genes, in which a group of fDLPs derived from dermatophytes are defined as a new family (fDEF8 according to sequence and phylogenetic analyses. In the oleaginous fungus Mortierella alpine, fDLPs have undergone extensive gene expansion. Our work further enlarges the fungal defensin family and will help characterize new peptide antibiotics with therapeutic potential.

  10. Phylogenetic structure of arbuscular mycorrhizal fungal communities along an elevation gradient.

    Science.gov (United States)

    Egan, Cameron P; Callaway, Ragan M; Hart, Miranda M; Pither, Jason; Klironomos, John

    2017-04-01

    Despite the importance of arbuscular mycorrhizal (AM) fungi within terrestrial ecosystems, we know little about how natural AM fungal communities are structured. To date, the majority of studies examining AM fungal community diversity have focused on single habitats with similar environmental conditions, with relatively few studies having assessed the diversity of AM fungi over large-scale environmental gradients. In this study, we characterized AM fungal communities in the soil along a high-elevation gradient in the North American Rocky Mountains. We focused on phylogenetic patterns of AM fungal communities to gain insight into how AM fungal communities are naturally assembled. We found that alpine AM fungal communities had lower phylogenetic diversity relative to lower elevation communities, as well as being more heterogeneous in composition than either treeline or subalpine communities. AM fungal communities were phylogenetically clustered at all elevations sampled, suggesting that environmental filtering, either selection by host plants or fungal niches, is the primary ecological process structuring communities along the gradient.

  11. Fungal contamination in hospital environments.

    Science.gov (United States)

    Perdelli, F; Cristina, M L; Sartini, M; Spagnolo, A M; Dallera, M; Ottria, G; Lombardi, R; Grimaldi, M; Orlando, P

    2006-01-01

    To assess the degree of fungal contamination in hospital environments and to evaluate the ability of air conditioning systems to reduce such contamination. We monitored airborne microbial concentrations in various environments in 10 hospitals equipped with air conditioning. Sampling was performed with a portable Surface Air System impactor with replicate organism detection and counting plates containing a fungus-selective medium. The total fungal concentration was determined 72-120 hours after sampling. The genera most involved in infection were identified by macroscopic and microscopic observation. The mean concentration of airborne fungi in the set of environments examined was 19 +/- 19 colony-forming units (cfu) per cubic meter. Analysis of the fungal concentration in the different types of environments revealed different levels of contamination: the lowest mean values (12 +/- 14 cfu/m(3)) were recorded in operating theaters, and the highest (45 +/- 37 cfu/m(3)) were recorded in kitchens. Analyses revealed statistically significant differences between median values for the various environments. The fungal genus most commonly encountered was Penicillium, which, in kitchens, displayed the highest mean airborne concentration (8 +/- 2.4 cfu/m(3)). The percentage (35%) of Aspergillus documented in the wards was higher than that in any of the other environments monitored. The fungal concentrations recorded in the present study are comparable to those recorded in other studies conducted in hospital environments and are considerably lower than those seen in other indoor environments that are not air conditioned. These findings demonstrate the effectiveness of air-handling systems in reducing fungal contamination.

  12. Lipopolysaccharide (LPS) stimulation of fungal secondary metabolism

    Science.gov (United States)

    Khalil, Zeinab G.; Kalansuriya, Pabasara; Capon, Robert J.

    2014-01-01

    We report on a preliminary investigation of the use the Gram-negative bacterial cell wall constituent lipopolysaccharide (LPS) as a natural chemical cue to stimulate and alter the expression of fungal secondary metabolism. Integrated high-throughput micro-cultivation and micro-analysis methods determined that 6 of 40 (15%) of fungi tested responded to an optimal exposure to LPS (0.6 ng/mL) by activating, enhancing or accelerating secondary metabolite production. To explore the possible mechanisms behind this effect, we employed light and fluorescent microscopy in conjunction with a nitric oxide (NO)-sensitive fluorescent dye and an NO scavenger to provide evidence that LPS stimulation of fungal secondary metabolism coincided with LPS activation of NO. Several case studies demonstrated that LPS stimulation can be scaled from single microplate well (1.5 mL) to preparative (>400 mL) scale cultures. For example, LPS treatment of Penicillium sp. (ACM-4616) enhanced pseurotin A and activated pseurotin A1 and pseurotin A2 biosynthesis, whereas LPS treatment of Aspergillus sp. (CMB-M81F) substantially accelerated and enhanced the biosynthesis of shornephine A and a series of biosynthetically related ardeemins and activated production of neoasterriquinone. As an indication of broader potential, we provide evidence that cultures of Penicillium sp. (CMB-TF0411), Aspergillus niger (ACM-4993F), Rhizopus oryzae (ACM-165F) and Thanatephorus cucumeris (ACM-194F) were responsive to LPS stimulation, the latter two examples being particular noteworthy as neither are known to produce secondary metabolites. Our results encourage the view that LPS stimulation can be used as a valuable tool to expand the molecular discovery potential of fungal strains that either have been exhaustively studied by or are unresponsive to traditional culture methodology. PMID:25379339

  13. Stem Cell Transplant Patients and Fungal Infections

    Science.gov (United States)

    ... Foodborne, Waterborne, and Environmental Diseases Mycotic Diseases Branch Stem Cell Transplant Patients and Fungal Infections Recommend on Facebook ... Mold . Top of Page Preventing fungal infections in stem cell transplant patients Fungi are difficult to avoid because ...

  14. Epidemic Network Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Katsikas, Dimitrios; Fagertun, Anna Manolova

    2013-01-01

    This paper presents a failure propagation model for transport networks which are affected by epidemic failures. The network is controlled using the GMPLS protocol suite. The Susceptible Infected Disabled (SID) epidemic model is investigated and new signaling functionality of GMPLS to support...

  15. Household demographic determinants of Ebola epidemic risk.

    Science.gov (United States)

    Adams, Ben

    2016-03-07

    A salient characteristic of Ebola, and some other infectious diseases such as Tuberculosis, is intense transmission among small groups of cohabitants and relatively limited indiscriminate transmission in the wider population. Here we consider a mathematical model for an Ebola epidemic in a population structured into households of equal size. We show that household size, a fundamental demographic unit, is a critical factor that determines the vulnerability of a community to epidemics, and the effort required to control them. Our analysis is based on the household reproduction number, but we also consider the basic reproduction number, intrinsic growth rate and final epidemic size. We show that, when other epidemiological parameters are kept the same, all of these quantifications of epidemic growth and size are increased by larger households and more intense within-household transmission. We go on to model epidemic control by case detection and isolation followed by household quarantine. We show that, if household quarantine is ineffective, the critical probability with which cases must be detected to halt an epidemic increases significantly with each increment in household size and may be a very challenging target for communities composed of large households. Effective quarantine may, however, mitigate the detrimental impact of large household sizes. We conclude that communities composed of large households are fundamentally more vulnerable to epidemics of infectious diseases primarily transmitted by close contact, and any assessment of control strategies for these epidemics should take into account the demographic structure of the population. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Malaria epidemic and drug resistance, Djibouti.

    Science.gov (United States)

    Rogier, Christophe; Pradines, Bruno; Bogreau, H; Koeck, Jean-Louis; Kamil, Mohamed-Ali; Mercereau-Puijalon, Odile

    2005-02-01

    Analysis of Plasmodium falciparum isolates collected before, during, and after a 1999 malaria epidemic in Djibouti shows that, despite a high prevalence of resistance to chloroquine, the epidemic cannot be attributed to a sudden increase in drug resistance of local parasite populations.

  17. Epidemics in interconnected small-world networks

    NARCIS (Netherlands)

    Liu, M.; Li, D.; Qin, P.; Liu, C.; Wang, H.; Wang, F.

    2015-01-01

    Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks

  18. Stemming the obesity epidemic : a tantalizing prospect

    NARCIS (Netherlands)

    Veerman, J Lennert; Barendregt, Jan J; van Beeck, Ed F; Seidell, Jacob C; Mackenbach, Johan P

    OBJECTIVE: Obesity is a growing problem worldwide, but there are no good methods to assess the future course of the epidemic and the potential influence of interventions. We explore the behavior change needed to stop the obesity epidemic in the U.S. RESEARCH METHODS AND PROCEDURES: We modeled the

  19. Inferring epidemic contact structure from phylogenetic trees.

    Directory of Open Access Journals (Sweden)

    Gabriel E Leventhal

    Full Text Available Contact structure is believed to have a large impact on epidemic spreading and consequently using networks to model such contact structure continues to gain interest in epidemiology. However, detailed knowledge of the exact contact structure underlying real epidemics is limited. Here we address the question whether the structure of the contact network leaves a detectable genetic fingerprint in the pathogen population. To this end we compare phylogenies generated by disease outbreaks in simulated populations with different types of contact networks. We find that the shape of these phylogenies strongly depends on contact structure. In particular, measures of tree imbalance allow us to quantify to what extent the contact structure underlying an epidemic deviates from a null model contact network and illustrate this in the case of random mixing. Using a phylogeny from the Swiss HIV epidemic, we show that this epidemic has a significantly more unbalanced tree than would be expected from random mixing.

  20. Epidemics in interconnected small-world networks.

    Science.gov (United States)

    Liu, Meng; Li, Daqing; Qin, Pengju; Liu, Chaoran; Wang, Huijuan; Wang, Feilong

    2015-01-01

    Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks has rarely been considered. Here, we study the susceptible-infected-susceptible (SIS) model of epidemic spreading in a system comprising two interconnected small-world networks. We find that the epidemic threshold in such networks decreases when the rewiring probability of the component small-world networks increases. When the infection rate is low, the rewiring probability affects the global steady-state infection density, whereas when the infection rate is high, the infection density is insensitive to the rewiring probability. Moreover, epidemics in interconnected small-world networks are found to spread at different velocities that depend on the rewiring probability.

  1. Epidemics in interconnected small-world networks.

    Directory of Open Access Journals (Sweden)

    Meng Liu

    Full Text Available Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks has rarely been considered. Here, we study the susceptible-infected-susceptible (SIS model of epidemic spreading in a system comprising two interconnected small-world networks. We find that the epidemic threshold in such networks decreases when the rewiring probability of the component small-world networks increases. When the infection rate is low, the rewiring probability affects the global steady-state infection density, whereas when the infection rate is high, the infection density is insensitive to the rewiring probability. Moreover, epidemics in interconnected small-world networks are found to spread at different velocities that depend on the rewiring probability.

  2. Fungal Endophytes: Beyond Herbivore Management

    Directory of Open Access Journals (Sweden)

    Bamisope S. Bamisile

    2018-03-01

    Full Text Available The incorporation of entomopathogenic fungi as biocontrol agents into Integrated Pest Management (IPM programs without doubt, has been highly effective. The ability of these fungal pathogens such as Beauveria bassiana and Metarhizium anisopliae to exist as endophytes in plants and protect their colonized host plants against the primary herbivore pests has widely been reported. Aside this sole role of pest management that has been traditionally ascribed to fungal endophytes, recent findings provided evidence of other possible functions as plant yield promoter, soil nutrient distributor, abiotic stress and drought tolerance enhancer in plants. However, reports on these additional important effects of fungal endophytes on the colonized plants remain scanty. In this review, we discussed the various beneficial effects of endophytic fungi on the host plants and their primary herbivore pests; as well as some negative effects that are relatively unknown. We also highlighted the prospects of our findings in further increasing the acceptance of fungal endophytes as an integral part of pest management programs for optimized crop production.

  3. DEMONSTRATION BULLETIN: FUNGAL TREATMENT BULLETIN

    Science.gov (United States)

    Fungal treatment technology uses white rot fungi (lignin degrading fungi) to treat organic contaminated soils in situ. Organic materials inoculated with the fungi are mechanically mixed into the contaminated soil. Using enzymes normally produced for wood degradation as well as ot...

  4. Cooperative epidemics on multiplex networks

    Science.gov (United States)

    Azimi-Tafreshi, N.

    2016-04-01

    The spread of one disease, in some cases, can stimulate the spreading of another infectious disease. Here, we treat analytically a symmetric coinfection model for spreading of two diseases on a two-layer multiplex network. We allow layer overlapping, but we assume that each layer is random and locally loopless. Infection with one of the diseases increases the probability of getting infected with the other. Using the generating function method, we calculate exactly the fraction of individuals infected with both diseases (so-called coinfected clusters) in the stationary state, as well as the epidemic spreading thresholds and the phase diagram of the model. With increasing cooperation, we observe a tricritical point and the type of transition changes from continuous to hybrid. Finally, we compare the coinfected clusters in the case of cooperating diseases with the so-called "viable" clusters in networks with dependencies.

  5. [Fungal infections of the gastrointestinal tract].

    Science.gov (United States)

    Maragkoudakis, Emmanouil; Realdi, Giuseppe; Dore, Maria Pina

    2005-06-01

    In immunocompetent subjects fungal infections of the gastrointestinal tract are uncommon. Candida esophagitis remains the single most common fungal infection in immunocompromised hosts or in H. pylori- infected patients who receive antibiotic therapy. Enteric fungal infections are uncommon even in HIV-infected patients. Antifungal agents such as amphotericin B, ketoconazole, fluconazole, and the various formulations of itraconazole are effective for most cases.

  6. Mycotoxicogenic fungal inhibition by innovative cheese cover with aromatic plants.

    Science.gov (United States)

    Moro, Armando; Librán, Celia M; Berruga, M Isabel; Zalacain, Amaya; Carmona, Manuel

    2013-03-30

    The use of aromatic plants and their extracts with antimicrobial properties may be compromised in the case of cheese, as some type of fungal starter is needed during its production. Penicillium verrucosum is considered a common cheese spoiler. The aim of this study was to evaluate the innovative use of certain aromatic plants as natural cheese covers in order to prevent mycotoxicogenic fungal growth (P. verrucosum). A collection of 12 essential oils (EOs) was obtained from various aromatic plants by solvent-free microwave extraction technology, and volatile characterisation of the EOs was carried out by gas chromatography/mass spectrometry. The most effective EOs against P. verrucosum were obtained from Anethum graveolens, Hyssopus officinalis and Chamaemelum nobile, yielding 50% inhibition of fungal growth at concentration values lower than 0.02 µL mL⁻¹. All EOs showed high volatile heterogeneity, with α-phellandrene, pinocamphone, isopinocamphone, α-pinene, camphene, 1,8-cineole, carvacrol and trans-anethole being found to be statistically significant in the antifungal model. The use of these aromatic plants as natural covers on cheese can satisfactorily inhibit the growth of some mycotoxicogenic fungal spoilers. Among the volatile compounds present, α- and β-phellandrene were confirmed as the most relevant in the inhibition. © 2012 Society of Chemical Industry.

  7. Subseafloor basalts as fungal habitats

    Directory of Open Access Journals (Sweden)

    M. Ivarsson

    2012-09-01

    Full Text Available The oceanic crust is believed to host the largest potential habitat for microbial life on Earth, yet, still we lack substantial information about the abundance, diversity, and consequence of its biosphere. The last two decades have involved major research accomplishments within this field and a change in view of the ocean crust and its potential to harbour life. Here fossilised fungal colonies in subseafloor basalts are reported from three different seamounts in the Pacific Ocean. The fungal colonies consist of various characteristic structures interpreted as fungal hyphae, fruit bodies and spores. The fungal hyphae are well preserved with morphological characteristics such as hyphal walls, septa, thallic conidiogenesis, and hyphal tips with hyphal vesicles within. The fruit bodies consist of large (∼50–200 µm in diameter body-like structures with a defined outer membrane and an interior filled with calcite. The fruit bodies have at some stage been emptied of their contents of spores and filled by carbonate-forming fluids. A few fruit bodies not filled by calcite and with spores still within support this interpretation. Spore-like structures (ranging from a few µm to ∼20 µm in diameter are also observed outside of the fruit bodies and in some cases concentrated to openings in the membrane of the fruit bodies. The hyphae, fruit bodies and spores are all closely associated with a crust lining the vein walls that probably represent a mineralized biofilm. The results support a fungal presence in deep subseafloor basalts and indicate that such habitats were vital between ∼81 and 48 Ma.

  8. EpSoc: Social-Based Epidemic-Based Routing Protocol in Opportunistic Mobile Social Network

    Directory of Open Access Journals (Sweden)

    Halikul Lenando

    2018-01-01

    Full Text Available In opportunistic networks, the nature of intermittent and disruptive connections degrades the efficiency of routing. Epidemic routing protocol is used as a benchmark for most of routing protocols in opportunistic mobile social networks (OMSNs due to its high message delivery and latency. However, Epidemic incurs high cost in terms of overhead and hop count. In this paper, we propose a hybrid routing protocol called EpSoc which utilizes the Epidemic routing forwarding strategy and exploits an important social feature, that is, degree centrality. Two techniques are used in EpSoc. Messages’ TTL is adjusted based on the degree centrality of nodes, and the message blocking mechanism is used to control replication. Simulation results show that EpSoc increases the delivery ratio and decreases the overhead ratio, the average latency, and the hop counts as compared to Epidemic and Bubble Rap.

  9. Fungal farming in a non-social beetle.

    Directory of Open Access Journals (Sweden)

    Wataru Toki

    Full Text Available Culturing of microbes for food production, called cultivation mutualism, has been well-documented from eusocial and subsocial insects such as ants, termites and ambrosia beetles, but poorly described from solitary, non-social insects. Here we report a fungal farming in a non-social lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae, which entails development of a special female structure for fungal storage/inoculation, so-called mycangium, and also obligate dependence of the insect on the fungal associate. Adult females of D. bucculenta bore a hole on a recently-dead bamboo culm with their specialized mandibles, lay an egg into the internode cavity, and plug the hole with bamboo fibres. We found that the inner wall of the bamboo internode harboring a larva is always covered with a white fungal layer. A specific Saccharomycetes yeast, Wickerhamomyces anomalus ( = Pichia anomala, was consistently isolated from the inner wall of the bamboo internodes and also from the body surface of the larvae. Histological examination of the ovipositor of adult females revealed an exoskeletal pocket on the eighth abdominal segment. The putative mycangium contained yeast cells, and W. anomalus was repeatedly detected from the symbiotic organ. When first instar larvae were placed on culture media inoculated with W. anomalus, they grew and developed normally to adulthood. By contrast, first instar larvae placed on either sterile culture media or autoclaved strips of bamboo inner wall exhibited arrested growth at the second instar, and addition of W. anomalus to the media resumed growth and development of the larvae. These results strongly suggest a mutualistic nature of the D. bucculenta-W. anomalus association with morphological specialization and physiological dependence. Based on these results, we compare the fungal farming of D. bucculenta with those of social and subsocial insects, and discuss ecological factors relevant to the

  10. DIAGNOSIS & MANAGEMENT OF ALLERGIC FUNGAL SINUSITIS

    Directory of Open Access Journals (Sweden)

    Syam Manohar Gadhamsetty

    2016-08-01

    Full Text Available BACKGROUND Chronic sinusitis is one of the common diagnosis in ENT practice. Allergic fungal sinusitis is a clinical entity with characteristic clinical, radiographic and histopathological findings. Allergic fungal sinusitis and eosinophilic mucin rhinosinusitis can easily be misdiagnosed. AIM OF STUDY A prospective clinical study of allergic Fungal Rhinosinusitis to use diagnostic criteria to confirm the disease with Radiological, Pathological & Microbiological investigations and their management. MATERIALS & METHODS A prospective study of allergic Fungal Rhinosinusitis in 2 years from November 2011 to October 2013. Among the patients who attended the ENT OPD during this period, 21 patients with symptoms and signs suggestive of Allergic Fungal Rhinosinusitis are selected.

  11. Coupled Metagenomic and Chemical Analyses of Degrading Fungal Necromass and Implications for Fungal contributions to Stable Soil Organic Carbon

    Science.gov (United States)

    Egerton-Warburton, L. M.; Schreiner, K. M.; Morgan, B. S. T.; Schultz, J.; Blair, N. E.

    2016-12-01

    Fungi comprise a significant portion of total soil biomass, the turnover of which must represent a dominant flux within the soil carbon cycle. Fungal organic carbon (OC) can turn over on time scales of days to months, but this process is poorly understood. Here, we examined temporal changes in the chemical and microbial community composition of fungal necromass during a 2-month decomposition experiment in which Fusarium avenaceum (a common saprophyte) was exposed to a natural soil microbial community. Over the course of the experiment, residual fungal necromass was harvested and analyzed using FTIR and thermochemolysis-GCMS to examine chemical changes in the tissue. In addition, genomic DNA was extracted from tissues, amplified with barcoded ITS primers, and sequenced using the high-throughput Illumina platform to examine changes in microbial community composition. Up to 80% of the fungal necromass turned over in the first week. This rapid degradation phase corresponded to colonization of the necromass by known chitinolytic soil fungi including Mortierella species. Members of the Zygomycota and Ascomycota were among the dominant fungal groups involved in degradation with very small contributions from Basidiomycota. At the end of the 2-month degradation, only 15% of the original necromass remained. The residual material was rich in amide and C-O moieties which is consistent with previous work predicting that peptidoglycans are the main residual product from microbial tissue degradation. Straight-chain fatty acids exhibited varying degradation profiles, with some fatty acids (e.g. C16, C18:1) degrading more rapidly than bulk tissue while others maintained steady concentrations relative to bulk OC (C18) or increased in concentration throughout the degradation sequence (C24). These results indicate that the turnover of fungal necromass has the potential to rapidly and significantly influence a variety of soil OC properties including C/N ratios, lipid biomarker

  12. Fungal endophytes: diversity and functional roles

    Science.gov (United States)

    Rodriguez, R.J.; White, J.F.; Arnold, A.E.; Redman, R.S.

    2009-01-01

    All plants in natural ecosystems appear to be symbiotic with fungal endophytes. This highly diverse group of fungi can have profound impacts on plant communities through increasing fitness by conferring abiotic and biotic stress tolerance, increasing biomass and decreasing water consumption, or decreasing fitness by altering resource allocation. Despite more than 100 yr of research resulting in thousands of journal articles, the ecological significance of these fungi remains poorly characterized. Historically, two endophytic groups (clavicipitaceous (C) and nonclavicipitaceous (NC)) have been discriminated based on phylogeny and life history traits. Here, we show that NC-endophytes represent three distinct functional groups based on host colonization and transmission, in planta biodiversity and fitness benefits conferred to hosts. Using this framework, we contrast the life histories, interactions with hosts and potential roles in plant ecophysiology of C- and NC-endophytes, and highlight several key questions for future work in endophyte biology.

  13. Fungal Phytotoxins in Sustainable Weed Management.

    Science.gov (United States)

    Vurro, Maurizio; Boari, Angela; Casella, Francesca; Zonno, Maria Chiara

    2018-01-01

    Fungal phytotoxins are natural secondary metabolites produced by plant pathogenic fungi during host-pathogen interactions. They have received considerable particular attention for elucidating disease etiology, and consequently to design strategies for disease control. Due to wide differences in their chemical structures, these toxic metabolites have different ecological and environmental roles and mechanisms of action. This review aims at summarizing the studies on the possible use of these metabolites as tools in biological and integrated weed management, e.g. as: novel and environmentally friendly herbicides; lead for novel compounds; sources of novel mechanisms of action. Moreover, the limiting factors for utilizing those metabolites in practice will also be briefly discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Percolation and epidemics in random clustered networks

    Science.gov (United States)

    Miller, Joel C.

    2009-08-01

    The social networks that infectious diseases spread along are typically clustered. Because of the close relation between percolation and epidemic spread, the behavior of percolation in such networks gives insight into infectious disease dynamics. A number of authors have studied percolation or epidemics in clustered networks, but the networks often contain preferential contacts in high degree nodes. We introduce a class of random clustered networks and a class of random unclustered networks with the same preferential mixing. Percolation in the clustered networks reduces the component sizes and increases the epidemic threshold compared to the unclustered networks.

  15. Isotopologue fractionation during N(2)O production by fungal denitrification.

    Science.gov (United States)

    Sutka, Robin L; Adams, Gerard C; Ostrom, Nathaniel E; Ostrom, Peggy H

    2008-12-01

    Identifying the importance of fungi to nitrous oxide (N2O) production requires a non-intrusive method for differentiating between fungal and bacterial N2O production such as natural abundance stable isotopes. We compare the isotopologue composition of N2O produced during nitrite reduction by the fungal denitrifiers Fusarium oxysporum and Cylindrocarpon tonkinense with published data for N2O production during bacterial nitrification and denitrification. The fractionation factors for bulk nitrogen isotope values for fungal denitrification were in the range -74.7 to -6.6 per thousand. There was an inverse relationship between the absolute value of the fractionation factors and the reaction rate constant. We interpret this in terms of variation in the relative importance of the rate constants for diffusion and enzymatic reduction in controlling the net isotope effect for N2O production during fungal denitrification. Over the course of nitrite reduction, the delta(18)O values for N2O remained constant and did not exhibit a relationship with the concentration characteristic of an isotope effect. This probably reflects isotopic exchange with water. Similar to the delta(18)O data, the site preference (SP; the difference in delta(15)N between the central and outer N atoms in N2O) was unrelated to concentration during nitrite reduction and, therefore, has the potential to act as a conservative tracer of production from fungal denitrification. The SP values of N2O produced by F. oxysporum and C. tonkinense were 37.1 +/- 2.5 per thousand and 36.9 +/- 2.8 per thousand, respectively. These SP values are similar to those obtained in pure culture studies of bacterial nitrification but quite distinct from SP values for bacterial denitrification. The large magnitude of the bulk nitrogen isotope fractionation and the delta(18)O values associated with fungal denitrification are distinct from bacterial production pathways; thus multiple isotopologue data holds much promise for

  16. CT and MRI features in bipolaris fungal sinusitis

    International Nuclear Information System (INIS)

    Aribandi, M.; Bazan III, C.

    2007-01-01

    Bipolaris is an increasingly recognized cause of fungal sinusitis. Reports of imaging features are sparse. Our purpose was to review the imaging features in patients with Bipolaris fungal sinusitis. A review of our data showed seven patients with culture-proven Bipolaris fungal sinusitis. Computed tomography of the paranasal sinuses in all the patients and MRI in five patients were analysed for the location, nature, extent of the disease and density/ signal characteristics on CT/MRI. The sphenoid and posterior ethmoid sinuses were most often involved (six of seven), followed by the anterior ethmoid sinus (five of seven), frontal sinus (four of seven) and maxillary sinus (three of seven) involvement. Five of seven cases had bilateral disease. Secretions were seen to fill the sinus and were expansile in nature in six of seven cases. Bony erosion was noted in all the patients. Air-fluid levels and bony sclerosis were rarely seen. Computed tomography showed central hyperdensity in all the cases. In the corresponding MR images (n = 5), the sinus contents appeared hyperintense on T1-weighted images and hypointense on T2-weighted images. Extension into the nasal cavity was found in six of seven cases. Five of seven cases had intracranial (extradural) spread. Intraorbital extension was seen in three of seven cases, with associated optic nerve compression in two. All the patients responded to surgical debridement, and systemic antifungal therapy was not required. Bipolaris fungal sinusitis typically presents with an allergic fungal sinusitis picture with expansile sinus opacification and bony erosions. There is central hyperdensity on CT scan, which appears hyperintense on T1-weighted and hypointense on T2-weighted MR images

  17. Temporal prediction of epidemic patterns in community networks

    International Nuclear Information System (INIS)

    Peng, Xiao-Long; Xu, Xin-Jian; Fu, Xinchu; Small, Michael

    2013-01-01

    Most previous studies of epidemic dynamics on complex networks suppose that the disease will eventually stabilize at either a disease-free state or an endemic one. In reality, however, some epidemics always exhibit sporadic and recurrent behaviour in one region because of the invasion from an endemic population elsewhere. In this paper we address this issue and study a susceptible–infected–susceptible epidemiological model on a network consisting of two communities, where the disease is endemic in one community but alternates between outbreaks and extinctions in the other. We provide a detailed characterization of the temporal dynamics of epidemic patterns in the latter community. In particular, we investigate the time duration of both outbreak and extinction, and the time interval between two consecutive inter-community infections, as well as their frequency distributions. Based on the mean-field theory, we theoretically analyse these three timescales and their dependence on the average node degree of each community, the transmission parameters and the number of inter-community links, which are in good agreement with simulations, except when the probability of overlaps between successive outbreaks is too large. These findings aid us in better understanding the bursty nature of disease spreading in a local community, and thereby suggesting effective time-dependent control strategies. (paper)

  18. Subseafloor basalts as fungal habitats

    Science.gov (United States)

    Ivarsson, M.; Bengtson, S.

    2013-12-01

    The oceanic crust makes up the largest potential habitat for life on Earth, yet next to nothing is known about the abundance, diversity and ecology of its biosphere. Our understanding of the deep biosphere of subseafloor crust is, with a few exceptions, based on a fossil record. Surprisingly, a majority of the fossilized microorganisms have been interpreted or recently re-interpreted as remnants of fungi rather than prokaryotes. Even though this might be due to a bias in fossilization the presence of fungi in these settings can not be neglected. We have examined fossilized microorganisms in drilled basalt samples collected at the Emperor Seamounts in the Pacific Ocean. Synchrotron-radiation X-ray tomography microscopy (SRXTM) studies has revealed a complex morphology and internal structure that corresponds to characteristic fungal morphology. Chitin was detected in the fossilized hyphae, which is another strong argument in favour of a fungal interpretation. Chitin is absent in prokaryotes but a substantial constituent in fungal cell walls. The fungal colonies consist of both hyphae and yeast-like growth states as well as resting structures and possible fruit bodies, thus, the fungi exist in vital colonies in subseafloor basalts. The fungi have also been involved in extensive weathering of secondary mineralisations. In terrestrial environments fungi are known as an important geobiological agent that promotes mineral weathering and decomposition of organic matter, and they occur in vital symbiosis with other microorganisms. It is probable to assume that fungi would play a similar role in subseafloor basalts and have great impact on the ecology and on biogeochemical cycles in such environments.

  19. Systemic fungal infections in neonates

    Directory of Open Access Journals (Sweden)

    Rao S

    2005-01-01

    Full Text Available Advances in neonatal management have led to considerable improvement in newborn survival. However, early (72hours onset systemic infections, both bacterial and fungal, remain a devastating complication and an important cause of morbidity and mortality in these babies. Most neonatal fungal infections are due to Candida species, particularly Candida albicans. The sources of candidiasis in NICU are often endogenous following colonization of the babies with fungi. About 10% of these babies get colonized in first week of life and up to 64% babies get colonized by 4 weeks of hospital stay. Disseminated candidiasis presents like bacterial sepsis and can involve multiple organs such as the kidneys, brain, eye, liver, spleen, bone, joints, meninges and heart. Confirming the diagnosis by laboratory tests is difficult and a high index of suspicion is required. The diagnosis of fungemia can be made definitely only by recovering the organism from blood or other sterile bodily fluid. Amphotericin B continues to be the mainstay of therapy for systemic fungal infections but its use is limited by the risks of nephrotoxicity and hypokalemia. Newer formulations of amphotericin B, namely the liposomal and the lipid complex forms, have recently become available and have been reported to have lesser toxicity. More recently Indian liposomal Amphotericin B derived from neutral lipids (L-Amp -LRC-1 has shown good response with less toxicity. A clinical trial with this preparation has shown to be safe and efficacious in neonatal fungal infections. Compared to other liposomal preparations, L-Amp-LRC-1 is effective at lower dose and is less expensive drug for the treatment of neonatal candidiasis.

  20. Fungal conservation: Protected species of fungi in South Serbia region

    Directory of Open Access Journals (Sweden)

    Sadiković, D.

    2013-12-01

    Full Text Available Protection and conservation of fungi has only recently became an issue of concern. Main motives for increased attention are uncontrolled, mass collecting of edible wild mushrooms and environmental pollution which leads to the rapid decline of their natural habitats, some of which are rich with rare and endangered species. By Serbian Nature Conservation Law 2010. there are 38 strictly protected fungal species of which 17 species are recorded in this paper. 11 of those recorded species are on European and/or National Red List of endangered fungal species. All investigated territories were in South Serbia region. This study is a contribution to conservation of protected and threatened fungi and their respective habitats in Serbia.

  1. Systems biology of fungal infection

    Directory of Open Access Journals (Sweden)

    Fabian eHorn

    2012-04-01

    Full Text Available Elucidation of pathogenicity mechanisms of the most important human pathogenic fungi, Aspergillus fumigatus and Candida albicans, has gained great interest in the light of the steadily increasing number of cases of invasive fungal infections.A key feature of these infections is the interaction of the different fungal morphotypes with epithelial and immune effector cells in the human host. Because of the high level of complexity, it is necessary to describe and understand invasive fungal infection by taking a systems biological approach, i.e., by a comprehensive quantitative analysis of the non-linear and selective interactions of a large number of functionally diverse, and frequently multifunctional, sets of elements, e.g., genes, proteins, metabolites, which produce coherent and emergent behaviours in time and space. The recent advances in systems biology will now make it possible to uncover the structure and dynamics of molecular and cellular cause-effect relationships within these pathogenic interactions.We review current efforts to integrate omics and image-based data of host-pathogen interactions into network and spatio-temporal models. The modelling will help to elucidate pathogenicity mechanisms and to identify diagnostic biomarkers and potential drug targets for therapy and could thus pave the way for novel intervention strategies based on novel antifungal drugs and cell therapy.

  2. Fungal genome resources at NCBI

    Science.gov (United States)

    Robbertse, B.; Tatusova, T.

    2011-01-01

    The National Center for Biotechnology Information (NCBI) is well known for the nucleotide sequence archive, GenBank and sequence analysis tool BLAST. However, NCBI integrates many types of biomolecular data from variety of sources and makes it available to the scientific community as interactive web resources as well as organized releases of bulk data. These tools are available to explore and compare fungal genomes. Searching all databases with Fungi [organism] at http://www.ncbi.nlm.nih.gov/ is the quickest way to find resources of interest with fungal entries. Some tools though are resources specific and can be indirectly accessed from a particular database in the Entrez system. These include graphical viewers and comparative analysis tools such as TaxPlot, TaxMap and UniGene DDD (found via UniGene Homepage). Gene and BioProject pages also serve as portals to external data such as community annotation websites, BioGrid and UniProt. There are many different ways of accessing genomic data at NCBI. Depending on the focus and goal of research projects or the level of interest, a user would select a particular route for accessing genomic databases and resources. This review article describes methods of accessing fungal genome data and provides examples that illustrate the use of analysis tools. PMID:22737589

  3. Epidemic spreading in a hierarchical social network.

    Science.gov (United States)

    Grabowski, A; Kosiński, R A

    2004-09-01

    A model of epidemic spreading in a population with a hierarchical structure of interpersonal interactions is described and investigated numerically. The structure of interpersonal connections is based on a scale-free network. Spatial localization of individuals belonging to different social groups, and the mobility of a contemporary community, as well as the effectiveness of different interpersonal interactions, are taken into account. Typical relations characterizing the spreading process, like a range of epidemic and epidemic curves, are discussed. The influence of preventive vaccinations on the spreading process is investigated. The critical value of preventively vaccinated individuals that is sufficient for the suppression of an epidemic is calculated. Our results are compared with solutions of the master equation for the spreading process and good agreement of the character of this process is found.

  4. Modeling Epidemics Spreading on Social Contact Networks.

    Science.gov (United States)

    Zhang, Zhaoyang; Wang, Honggang; Wang, Chonggang; Fang, Hua

    2015-09-01

    Social contact networks and the way people interact with each other are the key factors that impact on epidemics spreading. However, it is challenging to model the behavior of epidemics based on social contact networks due to their high dynamics. Traditional models such as susceptible-infected-recovered (SIR) model ignore the crowding or protection effect and thus has some unrealistic assumption. In this paper, we consider the crowding or protection effect and develop a novel model called improved SIR model. Then, we use both deterministic and stochastic models to characterize the dynamics of epidemics on social contact networks. The results from both simulations and real data set conclude that the epidemics are more likely to outbreak on social contact networks with higher average degree. We also present some potential immunization strategies, such as random set immunization, dominating set immunization, and high degree set immunization to further prove the conclusion.

  5. The prediction of epidemics through mathematical modeling.

    Science.gov (United States)

    Schaus, Catherine

    2014-01-01

    Mathematical models may be resorted to in an endeavor to predict the development of epidemics. The SIR model is one of the applications. Still too approximate, the use of statistics awaits more data in order to come closer to reality.

  6. The hidden epidemic: confronting sexually transmitted diseases

    National Research Council Canada - National Science Library

    Eng, Thomas R; Butler, William T

    .... In addition, STDs increase the risk of HIV transmission. The Hidden Epidemic examines the scope of sexually transmitted infections in the United States and provides a critical assessment of the nation's response to this public health crisis...

  7. Epidemic spreading on weighted complex networks

    International Nuclear Information System (INIS)

    Sun, Ye; Liu, Chuang; Zhang, Chu-Xu; Zhang, Zi-Ke

    2014-01-01

    Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

  8. Epidemic spreading on weighted complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ye [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Liu, Chuang, E-mail: liuchuang@hznu.edu.cn [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Chu-Xu [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Zi-Ke, E-mail: zhangzike@gmail.com [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China)

    2014-01-31

    Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

  9. Fungal Iron Biomineralization in Río Tinto

    Directory of Open Access Journals (Sweden)

    Monike Oggerin

    2016-04-01

    Full Text Available Although there are many studies on biomineralization processes, most of them focus on the role of prokaryotes. As fungi play an important role in different geological and biogeochemical processes, it was considered of interest to evaluate their role in a natural extreme acidic environment, Río Tinto, which has a high level of fungal diversity and a high concentration of metals. In this work we report, for the first time, the generation of iron oxyhydroxide minerals by the fungal community in a specific location of the Tinto basin. Using Transmission Electron Microscopy (TEM and High Angle Angular Dark Field coupled with Scanning Transmission Electron Microscopy (HAADF-STEM and Energy-Dispersive X-ray Spectroscopy (EDX, we observed fungal structures involved in the formation of iron oxyhydroxide minerals in mineralized sediment samples from the Río Tinto basin. Although Río Tinto waters are supersaturated in these minerals, they do not precipitate due to their slow precipitation kinetics. The presence of fungi, which simply provide charged surfaces for metal binding, favors the precipitation of Fe oxyhydroxides by overcoming these kinetic barriers. These results prove that the fungal community of Río Tinto participates very actively in the geochemical processes that take place there.

  10. Extraction of fungal polyketide pigments using ionic liquids.

    OpenAIRE

    Lebeau , Juliana ,; Venkatachalam , Mekala; Fouillaud , Mireille; Dufossé , Laurent; Caro , Yanis

    2016-01-01

    Poster communication, 8th International Conference of Pigments in Food, “Coloured foods for health benefits”, Cluj-Napoca, Romania, June 28 - July 01, 2016.; International audience; Filamentous fungi have been widely recognized as promising sources of various types ofbiomolecules and are therefore highly investigated. The production of fungal pigments is oneintensively studied domain in order to respond to the growing demand for natural colorants assubstitutes to synthetic dyes used in food, ...

  11. Epidemic Wave Dynamics Attributable to Urban Community Structure: A Theoretical Characterization of Disease Transmission in a Large Network

    Science.gov (United States)

    Eggo, Rosalind M; Lenczner, Michael

    2015-01-01

    Background Multiple waves of transmission during infectious disease epidemics represent a major public health challenge, but the ecological and behavioral drivers of epidemic resurgence are poorly understood. In theory, community structure—aggregation into highly intraconnected and loosely interconnected social groups—within human populations may lead to punctuated outbreaks as diseases progress from one community to the next. However, this explanation has been largely overlooked in favor of temporal shifts in environmental conditions and human behavior and because of the difficulties associated with estimating large-scale contact patterns. Objective The aim was to characterize naturally arising patterns of human contact that are capable of producing simulated epidemics with multiple wave structures. Methods We used an extensive dataset of proximal physical contacts between users of a public Wi-Fi Internet system to evaluate the epidemiological implications of an empirical urban contact network. We characterized the modularity (community structure) of the network and then estimated epidemic dynamics under a percolation-based model of infectious disease spread on the network. We classified simulated epidemics as multiwave using a novel metric and we identified network structures that were critical to the network’s ability to produce multiwave epidemics. Results We identified robust community structure in a large, empirical urban contact network from which multiwave epidemics may emerge naturally. This pattern was fueled by a special kind of insularity in which locally popular individuals were not the ones forging contacts with more distant social groups. Conclusions Our results suggest that ordinary contact patterns can produce multiwave epidemics at the scale of a single urban area without the temporal shifts that are usually assumed to be responsible. Understanding the role of community structure in epidemic dynamics allows officials to anticipate epidemic

  12. Epidemics and rumours in complex networks

    CERN Document Server

    Draief, Moez

    2009-01-01

    Information propagation through peer-to-peer systems, online social systems, wireless mobile ad hoc networks and other modern structures can be modelled as an epidemic on a network of contacts. Understanding how epidemic processes interact with network topology allows us to predict ultimate course, understand phase transitions and develop strategies to control and optimise dissemination. This book is a concise introduction for applied mathematicians and computer scientists to basic models, analytical tools and mathematical and algorithmic results. Mathematical tools introduced include coupling

  13. Phylogenetic distribution of fungal sterols.

    Directory of Open Access Journals (Sweden)

    John D Weete

    Full Text Available BACKGROUND: Ergosterol has been considered the "fungal sterol" for almost 125 years; however, additional sterol data superimposed on a recent molecular phylogeny of kingdom Fungi reveals a different and more complex situation. METHODOLOGY/PRINCIPAL FINDINGS: The interpretation of sterol distribution data in a modern phylogenetic context indicates that there is a clear trend from cholesterol and other Delta(5 sterols in the earliest diverging fungal species to ergosterol in later diverging fungi. There are, however, deviations from this pattern in certain clades. Sterols of the diverse zoosporic and zygosporic forms exhibit structural diversity with cholesterol and 24-ethyl -Delta(5 sterols in zoosporic taxa, and 24-methyl sterols in zygosporic fungi. For example, each of the three monophyletic lineages of zygosporic fungi has distinctive major sterols, ergosterol in Mucorales, 22-dihydroergosterol in Dimargaritales, Harpellales, and Kickxellales (DHK clade, and 24-methyl cholesterol in Entomophthorales. Other departures from ergosterol as the dominant sterol include: 24-ethyl cholesterol in Glomeromycota, 24-ethyl cholest-7-enol and 24-ethyl-cholesta-7,24(28-dienol in rust fungi, brassicasterol in Taphrinales and hypogeous pezizalean species, and cholesterol in Pneumocystis. CONCLUSIONS/SIGNIFICANCE: Five dominant end products of sterol biosynthesis (cholesterol, ergosterol, 24-methyl cholesterol, 24-ethyl cholesterol, brassicasterol, and intermediates in the formation of 24-ethyl cholesterol, are major sterols in 175 species of Fungi. Although most fungi in the most speciose clades have ergosterol as a major sterol, sterols are more varied than currently understood, and their distribution supports certain clades of Fungi in current fungal phylogenies. In addition to the intellectual importance of understanding evolution of sterol synthesis in fungi, there is practical importance because certain antifungal drugs (e.g., azoles target reactions in

  14. Phylodynamic analysis of HIV sub-epidemics in Mochudi, Botswana

    Directory of Open Access Journals (Sweden)

    Vlad Novitsky

    2015-12-01

    Real-time HIV genotyping and breaking down local HIV epidemics into phylogenetically distinct sub-epidemics may help to reveal the structure and dynamics of HIV transmission networks in communities, and aid in the design of targeted interventions for members of the acute sub-epidemics that likely fuel local HIV/AIDS epidemics.

  15. Is thermogenesis a significant causal factor in preventing the "globesity" epidemic?

    Science.gov (United States)

    Hansen, Jens Carl; Gilman, Andrew P; Odland, Jon Øyvind

    2010-08-01

    During the last four decades the world has experienced an epidemic of overweight individuals in affluent as well as developing countries. The WHO has predicted a "globesity epidemic" with more than 1 billion adults being overweight and at least 300 million of these being clinically obese. Obesity among children and adolescents is of great significance. From a global population perspective, this epidemic in weight gain and its sequelae are the largest public health problems identified to date and have very significant adverse implications for population health, and have by now almost reached the proportion of a pandemic. While genetic changes have been discussed as a cause of the epidemic, there has been too little time since its start to enable enough genetic adaptation to take place for this to provide a valid explanation. Traditionally positive energy balance and sedentary life style have been regarded as the primary causal factors; however, these factors have so far failed to provide explanations for the entire problem. For these reasons it seems warranted to investigate other possible co-factors contributing to the "globesity epidemic" and to find efficient strategies to counteract further increases in the size and nature of the epidemic. The purpose of this paper is to discuss a potential preventive co-factor, thermogenesis. Special attention has been paid to the influence of ambient temperature as a grossly neglected factor in the debate. As most people today live and work at ambient temperatures close to their body temperature (the thermal neutral point), we hypothesise that this is an important causal co-factor in the "globesity" epidemic. The hypothesis: The null hypothesis that adaptive thermogenesis in brown adipose tissue in adult humans is not significant for weight loss is rejected. We propose the hypothesis that homoeothermic living conditions close to the thermogenic neutral level is an important causal co-factor in the "Globesity" Epidemic

  16. Fungal infection risk groups among school children

    Directory of Open Access Journals (Sweden)

    Elżbieta Ejdas

    2014-08-01

    Full Text Available The aim of the study was to evaluate the relationship between ocurrence of fungi in children and living environment (city - countryside, sex, age, diet, undergone diseases therapy with antibiotics and exposure to hospital environment, and to indicate children potentially vulnerable to fungal infections. The material was consisted of swabs collected from the oral cavily, the throat and the nose of healthy children, aged 6-9 and 10-15, from both urban and rural environmens. Candida albicans, the basic aetiological factor in thc majority of mycoses recorded in humans, unquestionably prevailed in the group of the 13 speciec of yeast-like fungi and yeasts isolated. Records of C. glabrata and C. krusei increasing numbers of whose strains show resistance to basic antimycoties, as well as relatively frequent records of Trichosporon beigelii, Saccharomycopsis capsularis and Saccharomyces sp., fungi whose expansiveness and enzymatic activity have been growing, may be considered disconcerting. Vulnerability to fungal infection increases following anti-bacterial antibiotic therapy in the majority of subjects regardless season or age. This is particularly true primarily of the most stable ontocoenosis of the throat. Younger children, on the other hand, are the most vulnerable foUowing infection of the respiratory system. Fungi are likely to colonise the nose in this case. Children living in the countryside who had been ll immediately prior to the collection of the material constitute the highest risk group of the occurrence of fungi in any of the ontocoenoses studied. A greater number of positive inoculations were recorded in these children in comparison to the children from the city. It may be indicative of a more extensive spectrum of natural reservoirs of fungi and the vectors of their transmission in rural areas than those in the city, lower health hygiene and lower immunity or of a more common carriage of fungi among rural children.

  17. Epidemic disease decimates amphibian abundance, species diversity, and evolutionary history in the highlands of central Panama.

    Science.gov (United States)

    Crawford, Andrew J; Lips, Karen R; Bermingham, Eldredge

    2010-08-03

    Amphibian populations around the world are experiencing unprecedented declines attributed to a chytrid fungal pathogen, Batrachochytrium dendrobatidis. Despite the severity of the crisis, quantitative analyses of the effects of the epidemic on amphibian abundance and diversity have been unavailable as a result of the lack of equivalent data collected before and following disease outbreak. We present a community-level assessment combining long-term field surveys and DNA barcode data describing changes in abundance and evolutionary diversity within the amphibian community of El Copé, Panama, following a disease epidemic and mass-mortality event. The epidemic reduced taxonomic, lineage, and phylogenetic diversity similarly. We discovered that 30 species were lost, including five undescribed species, representing 41% of total amphibian lineage diversity in El Copé. These extirpations represented 33% of the evolutionary history of amphibians within the community, and variation in the degree of population loss and decline among species was random with respect to the community phylogeny. Our approach provides a fast, economical, and informative analysis of loss in a community whether measured by species or phylogenetic diversity.

  18. Fungal Endocarditis: Update on Diagnosis and Management.

    Science.gov (United States)

    Pasha, Ahmed Khurshid; Lee, Justin Z; Low, See-Wei; Desai, Hem; Lee, Kwan S; Al Mohajer, Mayar

    2016-10-01

    Fungal endocarditis is an extremely debilitating disease associated with high morbidity and mortality. Candida spp. are the most common isolated organisms in fungal endocarditis. It is most prevalent in patients who are immunosuppressed and intravenous drug users. Most patients present with constitutional symptoms, which are indistinguishable from bacterial endocarditis, hence a high index of suspicion is required for pursuing diagnosis. Diagnosis of fungal endocarditis can be very challenging: most of the time, blood cultures are negative or take a long time to yield growth. Fungal endocarditis mandates an aggressive treatment strategy. A medical and surgical combined approach is the cornerstone of therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Global food and fibre security threatened by current inefficiencies in fungal identification

    Science.gov (United States)

    2016-01-01

    Fungal pathogens severely impact global food and fibre crop security. Fungal species that cause plant diseases have mostly been recognized based on their morphology. In general, morphological descriptions remain disconnected from crucially important knowledge such as mating types, host specificity, life cycle stages and population structures. The majority of current fungal species descriptions lack even the most basic genetic data that could address at least some of these issues. Such information is essential for accurate fungal identifications, to link critical metadata and to understand the real and potential impact of fungal pathogens on production and natural ecosystems. Because international trade in plant products and introduction of pathogens to new areas is likely to continue, the manner in which fungal pathogens are identified should urgently be reconsidered. The technologies that would provide appropriate information for biosecurity and quarantine already exist, yet the scientific community and the regulatory authorities are slow to embrace them. International agreements are urgently needed to enforce new guidelines for describing plant pathogenic fungi (including key DNA information), to ensure availability of relevant data and to modernize the phytosanitary systems that must deal with the risks relating to trade-associated plant pathogens. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’. PMID:28080994

  20. Current ecological understanding of fungal-like pathogens of fish: what lies beneath?

    Directory of Open Access Journals (Sweden)

    Rodolphe Elie Gozlan

    2014-02-01

    Full Text Available Despite increasingly sophisticated microbiological techniques, and long after the first discovery of microbes, basic knowledge is still lacking to fully appreciate the ecological importance of microbial parasites in fish. This is likely due to the nature of their habitats as many species of fish suffer from living beneath turbid water away from easy recording. However, fishes represent key ecosystem services for millions of people around the world and the absence of a functional ecological understanding of viruses, prokaryotes, and small eukaryotes in the maintenance of fish populations and of their diversity represents an inherent barrier to aquatic conservation and food security. Among recent emerging infectious diseases responsible for severe population declines in plant and animal taxa, fungal and fungal-like microbes have emerged as significant contributors. Here, we review the current knowledge gaps of fungal and fungal-like parasites and pathogens in fish and put them into an ecological perspective with direct implications for the monitoring of fungal fish pathogens in the wild, their phylogeography as well as their associated ecological impact on fish populations. With increasing fish movement around the world for farming, releases into the wild for sport fishing and human-driven habitat changes, it is expected, along with improved environmental monitoring of fungal and fungal-like infections, that the full extent of the impact of these pathogens on wild fish populations will soon emerge as a major threat to freshwater biodiversity.

  1. Unraveling the role of fungal symbionts in plant abiotic stress tolerance

    Science.gov (United States)

    Singh, Lamabam Peter

    2011-01-01

    Fungal symbionts have been found to be associated with every plant studied in the natural ecosystem, where they colonize and reside entirely or partially in the internal tissues of their host plant. Fungal endophytes can express/form a range of different lifestyle/relationships with different host including symbiotic, mutualistic, commensalistic and parasitic in response to host genotype and environmental factors. In mutualistic association fungal endophyte can enhance growth, increase reproductive success and confer biotic and abiotic stress tolerance to its host plant. Since abiotic stress such as, drought, high soil salinity, heat, cold, oxidative stress and heavy metal toxicity is the common adverse environmental conditions that affect and limit crop productivity worldwide. It may be a promising alternative strategy to exploit fungal endophytes to overcome the limitations to crop production brought by abiotic stress. There is an increasing interest in developing the potential biotechnological applications of fungal endophytes for improving plant stress tolerance and sustainable production of food crops. Here we have described the fungal symbioses, fungal symbionts and their role in abiotic stress tolerance. A putative mechanism of stress tolerance by symbionts has also been covered. PMID:21512319

  2. Environment and geographic distance differ in relative importance for determining fungal community of rhizosphere and bulk soil.

    Science.gov (United States)

    Zhang, Kaoping; Adams, Jonathan M; Shi, Yu; Yang, Teng; Sun, Ruibo; He, Dan; Ni, Yingying; Chu, Haiyan

    2017-09-01

    Rhizospheric fungi play major roles in both natural and agricultural ecosystems. However, little is known about the determinants of their diversity and biogeographic patterns. Here, we compared fungal communities in rhizosphere and bulk soils of wheat fields in the North China Plain. The rhizosphere had a lower fungal diversity (observed OTUs and Chao1) than bulk soil, and a distinct fungal community structure in rhizosphere compared with bulk soil. The relative importance of environmental factors and geographic distance for fungal distribution differed between rhizosphere and bulk soil. Environmental factors were the primary cause of variations in total fungal community and major fungal phyla in bulk soil. By contrast, fungal communities in soils loosely attached to roots were predictable from both environmental factors and influences of geographic distance. Communities in soils tightly attached to roots were mainly determined by geographic distance. Our results suggest that both contemporary environment processes (present-day abiotic and biotic environment characters) and historical processes (spatial isolation, dispersal limitation occurred in the past) dominate variations of fungal communities in wheat fields, but their relative importance of all these processes depends on the proximity of fungal community to the plant roots. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Concurrency can drive an HIV epidemic by moving R0 across the epidemic threshold

    NARCIS (Netherlands)

    Leung, Ka Yin; Kretzschmar, Mirjam

    2015-01-01

    OBJECTIVE: The objective of this study is to investigate whether concurrency can drive an HIV epidemic by moving R0 across the epidemic threshold. DESIGN AND METHODS: We use a mathematical framework for a dynamic partnership network and the spread of a one-stage infection to study how concurrency is

  4. Large-scale application of highly-diluted bacteria for Leptospirosis epidemic control.

    Science.gov (United States)

    Bracho, Gustavo; Varela, Enrique; Fernández, Rolando; Ordaz, Barbara; Marzoa, Natalia; Menéndez, Jorge; García, Luis; Gilling, Esperanza; Leyva, Richard; Rufín, Reynaldo; de la Torre, Rubén; Solis, Rosa L; Batista, Niurka; Borrero, Reinier; Campa, Concepción

    2010-07-01

    Leptospirosis is a zoonotic disease of major importance in the tropics where the incidence peaks in rainy seasons. Natural disasters represent a big challenge to Leptospirosis prevention strategies especially in endemic regions. Vaccination is an effective option but of reduced effectiveness in emergency situations. Homeoprophylactic interventions might help to control epidemics by using highly-diluted pathogens to induce protection in a short time scale. We report the results of a very large-scale homeoprophylaxis (HP) intervention against Leptospirosis in a dangerous epidemic situation in three provinces of Cuba in 2007. Forecast models were used to estimate possible trends of disease incidence. A homeoprophylactic formulation was prepared from dilutions of four circulating strains of Leptospirosis. This formulation was administered orally to 2.3 million persons at high risk in an epidemic in a region affected by natural disasters. The data from surveillance were used to measure the impact of the intervention by comparing with historical trends and non-intervention regions. After the homeoprophylactic intervention a significant decrease of the disease incidence was observed in the intervention regions. No such modifications were observed in non-intervention regions. In the intervention region the incidence of Leptospirosis fell below the historic median. This observation was independent of rainfall. The homeoprophylactic approach was associated with a large reduction of disease incidence and control of the epidemic. The results suggest the use of HP as a feasible tool for epidemic control, further research is warranted. 2010 Elsevier Ltd. All rights reserved.

  5. Leveraging social networks for understanding the evolution of epidemics

    Science.gov (United States)

    2011-01-01

    Background To understand how infectious agents disseminate throughout a population it is essential to capture the social model in a realistic manner. This paper presents a novel approach to modeling the propagation of the influenza virus throughout a realistic interconnection network based on actual individual interactions which we extract from online social networks. The advantage is that these networks can be extracted from existing sources which faithfully record interactions between people in their natural environment. We additionally allow modeling the characteristics of each individual as well as customizing his daily interaction patterns by making them time-dependent. Our purpose is to understand how the infection spreads depending on the structure of the contact network and the individuals who introduce the infection in the population. This would help public health authorities to respond more efficiently to epidemics. Results We implement a scalable, fully distributed simulator and validate the epidemic model by comparing the simulation results against the data in the 2004-2005 New York State Department of Health Report (NYSDOH), with similar temporal distribution results for the number of infected individuals. We analyze the impact of different types of connection models on the virus propagation. Lastly, we analyze and compare the effects of adopting several different vaccination policies, some of them based on individual characteristics -such as age- while others targeting the super-connectors in the social model. Conclusions This paper presents an approach to modeling the propagation of the influenza virus via a realistic social model based on actual individual interactions extracted from online social networks. We implemented a scalable, fully distributed simulator and we analyzed both the dissemination of the infection and the effect of different vaccination policies on the progress of the epidemics. The epidemic values predicted by our simulator match

  6. Leveraging social networks for understanding the evolution of epidemics

    Directory of Open Access Journals (Sweden)

    Martín Gonzalo

    2011-12-01

    Full Text Available Abstract Background To understand how infectious agents disseminate throughout a population it is essential to capture the social model in a realistic manner. This paper presents a novel approach to modeling the propagation of the influenza virus throughout a realistic interconnection network based on actual individual interactions which we extract from online social networks. The advantage is that these networks can be extracted from existing sources which faithfully record interactions between people in their natural environment. We additionally allow modeling the characteristics of each individual as well as customizing his daily interaction patterns by making them time-dependent. Our purpose is to understand how the infection spreads depending on the structure of the contact network and the individuals who introduce the infection in the population. This would help public health authorities to respond more efficiently to epidemics. Results We implement a scalable, fully distributed simulator and validate the epidemic model by comparing the simulation results against the data in the 2004-2005 New York State Department of Health Report (NYSDOH, with similar temporal distribution results for the number of infected individuals. We analyze the impact of different types of connection models on the virus propagation. Lastly, we analyze and compare the effects of adopting several different vaccination policies, some of them based on individual characteristics -such as age- while others targeting the super-connectors in the social model. Conclusions This paper presents an approach to modeling the propagation of the influenza virus via a realistic social model based on actual individual interactions extracted from online social networks. We implemented a scalable, fully distributed simulator and we analyzed both the dissemination of the infection and the effect of different vaccination policies on the progress of the epidemics. The epidemic values

  7. HIV epidemics in Shenzhen and Chongqing, China.

    Directory of Open Access Journals (Sweden)

    Shu Yang

    Full Text Available Men who have sex with men (MSM and heterosexuals are the populations with the fastest growing HIV infection rates in China. We characterize the epidemic growth and age patterns between these two routes from 2004 to 2015 in Chongqing and Shenzhen, China.Data were downloaded from the National HIV/ AIDS Comprehensive Response Information Management System. For the new HIV diagnoses of heterosexuals and MSM in both cities, we estimated the growth rates by fitting different sub-exponential models. Heat maps are used to show their age patterns. We used histograms to compare these patterns by birth cohort.The MSM epidemics grew significantly in both cities. Chongqing experienced quadratic growth in HIV reported cases with an estimated growth rate of 0.086 per week and a "deceleration rate" of 0.673. HIV reported cases of MSM in Shenzhen grew even more drastically with a growth rate of 0.033 per week and "deceleration rate" of 0.794. The new infections are mainly affecting the ages of 18 to 30 in Chongqing and ages of 20 to 35 in Shenzhen. They peaked in early 1990's and mid-1990's birth cohorts in Chongqing and Shenzhen respectively. The HIV epidemic among heterosexuals grew rapidly in both cities. The growth rates were estimated as 0.02 and 0.028 in Chongqing and Shenzhen respectively whereas the "deceleration rates" were 0.878 and 0.790 in these two places. It affected mostly aged 18 to 75 in males and 18 to 65 in females in Chongqing and aged 18 to 45 in males and 18 to 50 in females in Shenzhen in 2015. In Chongqing, the heterosexual female epidemics display two peaks in HIV diagnoses in the birth cohorts of early 1950's and early 1980's, with heterosexual male epidemics peaked in early 1940's and early 1960's. The heterosexual male and female epidemics display higher rates in the birth cohort 1940-1960, than the birth cohort 1960-1990. It peaked in birth cohorts of 1950's and 1980's in Shenzhen.We revealed striking differences in epidemic growth

  8. Impact of interventions and the incidence of ebola virus disease in Liberia-implications for future epidemics.

    Science.gov (United States)

    Kirsch, Thomas D; Moseson, Heidi; Massaquoi, Moses; Nyenswah, Tolbert G; Goodermote, Rachel; Rodriguez-Barraquer, Isabel; Lessler, Justin; Cumings, Derek A T; Peters, David H

    2017-03-01

    To better understand the impact of national and global efforts to contain the Ebola virus disease epidemic of 2014–15 in Liberia, we provide a detailed timeline of the major interventions and relate them to the epidemic curve.  In addition to personal experience in the response, we systematically reviewed situation reports from the Liberian government, UN, CDC, WHO, UNICEF, IFRC, USAID, and local and international news reports to create the timeline. We extracted data on the timing and nature of activities and compared them to the timeline of the epidemic curve using the reproduction number—the estimate of the average number of new cases caused by a single case.  Interventions were organized around five major strategies, with the majority of resources directed to the creation of treatment beds. We conclude that no single intervention stopped the epidemic; rather, the interventions likely had reinforcing effects, and some were less likely than others to have made a major impact. We find that the epidemic’s turning coincided with a reorganization of the response in August–September 2014, the emergence of community leadership in control efforts, and changing beliefs and practices in the population. Ebola Treatment Units were important for Ebola treatment, but the vast majority of these treatment centre beds became available after the epidemic curve began declining. Similarly, the United Nations Mission for Ebola Emergency Response was launched after the epidemic curve had already turned.  These findings have significant policy implications for future epidemics and suggest that much of the decline in the epidemic curve was driven by critical behaviour changes within local communities, rather than by international efforts that came after the epidemic had turned. Future global interventions in epidemic response should focus on building community capabilities, strengthening local ownership, and dramatically reducing delays in the response.

  9. Fungal and bacterial metabolites in commercial poultry feed from Nigeria.

    Science.gov (United States)

    Ezekiel, C N; Bandyopadhyay, R; Sulyok, M; Warth, B; Krska, R

    2012-08-01

    Metabolites of toxigenic fungi and bacteria occur as natural contaminants (e.g. mycotoxins) in feedstuffs making them unsafe to animals. The multi-toxin profiles in 58 commercial poultry feed samples collected from 19 districts in 17 states of Nigeria were determined by LC/ESI-MS/MS with a single extraction step and no clean-up. Sixty-three (56 fungal and seven bacterial) metabolites were detected with concentrations ranging up to 10,200 µg kg⁻¹ in the case of aurofusarin. Fusarium toxins were the most prevalent group of fungal metabolites, whereas valinomycin occurred in more than 50% of the samples. Twelve non-regulatory fungal and seven bacterial metabolites detected and quantified in this study have never been reported previously in naturally contaminated stored grains or finished feed. Among the regulatory toxins in poultry feed, aflatoxin concentrations in 62% of samples were above 20 µg kg⁻¹, demonstrating high prevalence of unsafe levels of aflatoxins in Nigeria. Deoxynivalenol concentrations exceeded 1000 µg kg⁻¹ in 10.3% of samples. Actions are required to reduce the consequences from regulatory mycotoxins and understand the risks of the single or co-occurrence of non-regulatory metabolites for the benefit of the poultry industry.

  10. Ten Putative Contributors to the Obesity Epidemic

    Science.gov (United States)

    McAllister, Emily J.; Dhurandhar, Nikhil V.; Keith, Scott W.; Aronne, Louis J.; Barger, Jamie; Baskin, Monica; Benca, Ruth M.; Biggio, Joseph; Boggiano, Mary M.; Eisenmann, Joe C.; Elobeid, Mai; Fontaine, Kevin R.; Gluckman, Peter; Hanlon, Erin C.; Katzmarzyk, Peter; Pietrobelli, Angelo; Redden, David T.; Ruden, Douglas M.; Wang, Chenxi; Waterland, Robert A.; Wright, Suzanne M.; Allison, David B.

    2010-01-01

    The obesity epidemic is a global issue and shows no signs of abating, while the cause of this epidemic remains unclear. Marketing practices of energy-dense foods and institutionally-driven declines in physical activity are the alleged perpetrators for the epidemic, despite a lack of solid evidence to demonstrate their causal role. While both may contribute to obesity, we call attention to their unquestioned dominance in program funding and public efforts to reduce obesity, and propose several alternative putative contributors that would benefit from equal consideration and attention. Evidence for microorganisms, epigenetics, increasing maternal age, greater fecundity among people with higher adiposity, assortative mating, sleep debt, endocrine disruptors, pharmaceutical iatrogenesis, reduction in variability of ambient temperatures, and intrauterine and intergenerational effects, as contributing factors to the obesity epidemic are reviewed herein. While the evidence is strong for some contributors such as pharmaceutical-induced weight gain, it is still emerging for other reviewed factors. Considering the role of such putative etiological factors of obesity may lead to comprehensive, cause specific, and effective strategies for prevention and treatment of this global epidemic. PMID:19960394

  11. De novo genome assembly of the fungal plant pathogen Pyrenophora semeniperda

    Science.gov (United States)

    Marcus M. Soliai; Susan E. Meyer; Joshua A. Udall; David E. Elzinga; Russell A. Hermansen; Paul M. Bodily; Aaron A. Hart; Craig E. Coleman

    2014-01-01

    Pyrenophora semeniperda (anamorph Drechslera campulata) is a necrotrophic fungal seed pathogen that has a wide host range within the Poaceae. One of its hosts is cheatgrass (Bromus tectorum), a species exotic to the United States that has invaded natural ecosystems of the Intermountain West. As a natural pathogen of cheatgrass, P. semeniperda has potential as a...

  12. Fungal transmission of plant viruses.

    Science.gov (United States)

    Campbell, R N

    1996-01-01

    Thirty soilborne viruses or virus-like agents are transmitted by five species of fungal vectors. Ten polyhedral viruses, of which nine are in the family Tombusviridae, are acquired in the in vitro manner and do not occur within the resting spores of their vectors, Olpidium brassicae and O. bornovanus. Fungal vectors for other viruses in the family should be sought even though tombusviruses are reputed to be soil transmitted without a vector. Eighteen rod-shaped viruses belonging to the furo- and bymovirus groups and to an unclassified group are acquired in the in vivo manner and survive within the resting spores of their vector, O. brassicae, Polymyxa graminis, P. betae, and Spongospora subterranea. The viral coat protein has an essential role in in vitro transmission. With in vivo transmission a site in the coat protein-read through protein (CP-RT) of beet necrotic yellow vein furovirus determines vector transmissibility as does a site in a similar 98-kDa polyprotein of barley mild mosaic bymovirus. The mechanisms by which virions move (or are moved) into and out of the protoplasm of zoospores or of thalli needs study.

  13. [Iron and invasive fungal infection].

    Science.gov (United States)

    Álvarez, Florencio; Fernández-Ruiz, Mario; Aguado, José María

    2013-01-01

    Iron is an essential factor for both the growth and virulence of most of microorganisms. As a part of the innate (or nutritional) immune system, mammals have developed different mechanisms to store and transport this element in order to limit free iron bioavailability. To survive in this hostile environment, pathogenic fungi have specific uptake systems for host iron sources, one of the most important of which is based on the synthesis of siderophores-soluble, low-molecular-mass, high-affinity iron chelators. The increase in free iron that results from iron-overload conditions is a well-established risk factor for invasive fungal infection (IFI) such as mucormycosis or aspergillosis. Therefore, iron chelation may be an appealing therapeutic option for these infections. Nevertheless, deferoxamine -the first approved iron chelator- paradoxically increases the incidence of IFI, as it serves as a xeno-siderophore to Mucorales. On the contrary, the new oral iron chelators (deferiprone and deferasirox) have shown to exert a deleterious effect on fungal growth both in vitro and in animal models. The present review focuses on the role of iron metabolism in the pathogenesis of IFI and summarises the preclinical data, as well as the limited clinical experience so far, in the use of new iron chelators as treatment for mucormycosis and invasive aspergillosis. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  14. Mucormycosis: a rare fungal infection in tornado victims.

    Science.gov (United States)

    Austin, Cindy L; Finley, Phillip J; Mikkelson, Debbie R; Tibbs, Brian

    2014-01-01

    This article reviews four immunocompetent patients who developed a rare fungal infection, mucormycosis, secondary to multiple traumatic injuries sustained during an EF-5 tornado in Joplin, MO. Commonly found in soil and decaying organic matter, mucorales are fungi associated with soft tissue and cutaneous infections. Onset of this fungal infection can occur without clinical signs, presenting several days to several weeks after injury, delaying diagnosis. A multidisciplinary treatment approach including aggressive antifungal therapy and aggressive surgical debridement is critical. This diagnosis should be considered in all patients presenting with injuries sustained from high-velocity embedment of debris such as natural disasters or explosions. We present four cases of mucormycosis, species Apophysomyces trapeziformis. Data reported includes predisposing factors, number of days between injury and diagnosis of mucormycosis, surgical treatment, antifungal therapy, outcomes, and potential risk factors that may have contributed to the development of mucormycosis.

  15. Myco-fluidics: The fluid dynamics of fungal chimerism

    Science.gov (United States)

    Roper, Marcus; Hickey, Patrick; Dressaire, Emilie; Roch, Sebastien

    2012-11-01

    Chimeras-fantastical creatures formed as amalgams of many animals-have captured the human imagination since Ancient times. But they are also surprisingly common in Nature. The syncytial cells of filamentous fungi harbor large numbers of nuclei bathed in a single cytoplasm. As a fungus grows these nuclei become genetically diverse, either from mutation or from exchange of nuclei between different fungal individuals, a process that is known to increase the virulence of the fungus and its adaptability. By directly measuring nuclear movement in the model ascomycete fungus Neurospora crassa, we show that the fungus' tolerance for internal genetic diversity is enabled by hydrodynamic mixing of nuclei acting at all length scales within the fungal mycelium. Mathematical modeling and experiments in a mutant with altered mycelial morphology reveal some of the exquisite hydraulic engineering necessary to create these mixing flows from spatially coarse pressure gradients.

  16. Cellulolytic potential of thermophilic species from four fungal orders

    DEFF Research Database (Denmark)

    Busk, Peter Kamp; Lange, Lene

    2013-01-01

    and in characterization of their industrially useful enzymes. In the present study we investigated the cellulolytic potential of 16 thermophilic fungi from the three ascomycete orders Sordariales, Eurotiales and Onygenales and from the zygomycete order Mucorales thus covering all fungal orders that include thermophiles....... Thermophilic fungi are the only described eukaryotes that can grow at temperatures above 45 ºC. All 16 fungi were able to grow on crystalline cellulose but their secreted enzymes showed widely different cellulolytic activities, pH optima and thermostabilities. Interestingly, in contrast to previous reports, we......Elucidation of fungal biomass degradation is important for understanding the turnover of biological materials in nature and has important implications for industrial biomass conversion. In recent years there has been an increasing interest in elucidating the biological role of thermophilic fungi...

  17. [Invasive fungal disease due to Scedosporium, Fusarium and mucorales].

    Science.gov (United States)

    Pemán, Javier; Salavert, Miguel

    2014-01-01

    The number of emerging organisms causing invasive fungal infections has increased in the last decades. These etiological agents include Scedosporium, Fusarium and mucorales. All of them can cause disseminated, virulent, and difficult-to treat infections in immunosuppressed patients, the most affected, due to their resistance to most available antifungal agents. Current trends in transplantation including the use of new immunosuppressive treatments, the common prescription of antifungal agents for prophylaxis, and new ecological niches could explain the emergence of these fungal pathogens. These pathogens can also affect immunocompetent individuals, especially after natural disasters (earthquakes, floods, tsunamis), combat wounds or near drowning. All the invasive infections caused by Scedosporium, Fusarium, and mucorales are potentially lethal and a favourable outcome is associated with rapid diagnosis by direct microscopic examination of the involved tissue, wide debridement of infected material, early use of antifungal agents including combination therapy, and an improvement in host defenses, especially neutropenia. Copyright © 2014. Published by Elsevier Espana.

  18. Strategies to Characterize Fungal Lipases for Applications in Medicine and Dairy Industry

    Science.gov (United States)

    Gopinath, Subash C. B.; Anbu, Periasamy; Lakshmipriya, Thangavel; Hilda, Azariah

    2013-01-01

    Lipases are water-soluble enzymes that act on insoluble substrates and catalyze the hydrolysis of long-chain triglycerides. Lipases play a vital role in the food, detergent, chemical, and pharmaceutical industries. In the past, fungal lipases gained significant attention in the industries due to their substrate specificity and stability under varied chemical and physical conditions. Fungal enzymes are extracellular in nature, and they can be extracted easily, which significantly reduces the cost and makes this source preferable over bacteria. Soil contaminated with spillage from the products of oil and dairy harbors fungal species, which have the potential to secrete lipases to degrade fats and oils. Herein, the strategies involved in the characterization of fungal lipases, capable of degrading fatty substances, are narrated with a focus on further applications. PMID:23865040

  19. Landscape changes in the environment due to military actions and their epidemic risks

    Directory of Open Access Journals (Sweden)

    Krushelnitsky A.D.

    2016-05-01

    Full Text Available The article considers the influence of the military-ecological and man-caused-anthropogenic factors on the environment state and natural processes. Epidemic risks and consequences resulted from landscapic changes of the environment which arise as a result of war and destruction of ecosystems are described.

  20. Can epidemics be non-communicable?

    DEFF Research Database (Denmark)

    Seeberg, Jens; Meinert, Lotte

    2015-01-01

    This article argues that the concept of communicability that is central to the distinction between communicable diseases (CDs) and noncommunicable diseases (NCDs) is poorly conceptualized. The epidemic spread of NCDs such as diabetes, depression, and eating disorders demonstrates...... that they are communicable, even if they are not infectious. We need to more critically explore how they might be communicable in specific environments. All diseases with epidemic potential, we argue, should be assumed to be commun icable in a broader sense, and that the underlying medical distinction between infectious...... and noninfectious diseases confuses our understanding of NCD epidemics when these categories are treated as synonymous with ‘communicable’ and ‘noncommunicable’ diseases, respectively. The dominant role accorded to the concept of ‘lifestyle’, with its focus on individual responsibility, is part of the problem...

  1. Worm epidemics in wireless ad hoc networks

    Energy Technology Data Exchange (ETDEWEB)

    Nekovee, Maziar [BT Research, Polaris 134, Adastral Park, Martlesham, Suffolk IP5 3RE (United Kingdom); Centre for Computational Science, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)

    2007-06-15

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

  2. Urgent epidemic control mechanism for aviation networks

    KAUST Repository

    Peng, Chengbin; Wang, Shengbin; Shi, Meixia; Jin, Xiaogang

    2011-01-01

    In the current century, the highly developed transportation system can not only boost the economy, but also greatly accelerate the spreading of epidemics. While some epidemic diseases may infect quite a number of people ahead of our awareness, the health care resources such as vaccines and the medical staff are usually locally or even globally insufficient. In this research, with the network of major aviation routes as an example, we present a method to determine the optimal locations to allocate the medical service in order to minimize the impact of the infectious disease with limited resources. Specifically, we demonstrate that when the medical resources are insufficient, we should concentrate our efforts on the travelers with the objective of effectively controlling the spreading rate of the epidemic diseases. © 2011 Springer-Verlag Berlin Heidelberg.

  3. Vaccination intervention on epidemic dynamics in networks

    Science.gov (United States)

    Peng, Xiao-Long; Xu, Xin-Jian; Fu, Xinchu; Zhou, Tao

    2013-02-01

    Vaccination is an important measure available for preventing or reducing the spread of infectious diseases. In this paper, an epidemic model including susceptible, infected, and imperfectly vaccinated compartments is studied on Watts-Strogatz small-world, Barabási-Albert scale-free, and random scale-free networks. The epidemic threshold and prevalence are analyzed. For small-world networks, the effective vaccination intervention is suggested and its influence on the threshold and prevalence is analyzed. For scale-free networks, the threshold is found to be strongly dependent both on the effective vaccination rate and on the connectivity distribution. Moreover, so long as vaccination is effective, it can linearly decrease the epidemic prevalence in small-world networks, whereas for scale-free networks it acts exponentially. These results can help in adopting pragmatic treatment upon diseases in structured populations.

  4. Worm epidemics in wireless ad hoc networks

    Science.gov (United States)

    Nekovee, Maziar

    2007-06-01

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

  5. GENERAL: Epidemic spreading on networks with vaccination

    Science.gov (United States)

    Shi, Hong-Jing; Duan, Zhi-Sheng; Chen, Guan-Rong; Li, Rong

    2009-08-01

    In this paper, a new susceptible-infected-susceptible (SIS) model on complex networks with imperfect vaccination is proposed. Two types of epidemic spreading patterns (the recovered individuals have or have not immunity) on scale-free networks are discussed. Both theoretical and numerical analyses are presented. The epidemic thresholds related to the vaccination rate, the vaccination-invalid rate and the vaccination success rate on scale-free networks are demonstrated, showing different results from the reported observations. This reveals that whether or not the epidemic can spread over a network under vaccination control is determined not only by the network structure but also by the medicine's effective duration. Moreover, for a given infective rate, the proportion of individuals to vaccinate can be calculated theoretically for the case that the recovered nodes have immunity. Finally, simulated results are presented to show how to control the disease prevalence.

  6. Different Epidemic Models on Complex Networks

    International Nuclear Information System (INIS)

    Zhang Haifeng; Small, Michael; Fu Xinchu

    2009-01-01

    Models for diseases spreading are not just limited to SIS or SIR. For instance, for the spreading of AIDS/HIV, the susceptible individuals can be classified into different cases according to their immunity, and similarly, the infected individuals can be sorted into different classes according to their infectivity. Moreover, some diseases may develop through several stages. Many authors have shown that the individuals' relation can be viewed as a complex network. So in this paper, in order to better explain the dynamical behavior of epidemics, we consider different epidemic models on complex networks, and obtain the epidemic threshold for each case. Finally, we present numerical simulations for each case to verify our results.

  7. Worm epidemics in wireless ad hoc networks

    International Nuclear Information System (INIS)

    Nekovee, Maziar

    2007-01-01

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet

  8. The epidemic of Tuberculosis on vaccinated population

    Science.gov (United States)

    Syahrini, Intan; Sriwahyuni; Halfiani, Vera; Meurah Yuni, Syarifah; Iskandar, Taufiq; Rasudin; Ramli, Marwan

    2017-09-01

    Tuberculosis is an infectious disease which has caused a large number of mortality in Indonesia. This disease is caused by Mycrobacterium tuberculosis. Besides affecting lung, this disease also affects other organs such as lymph gland, intestine, kidneys, uterus, bone, and brain. This article discusses the epidemic of tuberculosis through employing the SEIR model. Here, the population is divided into four compartments which are susceptible, exposed, infected and recovered. The susceptible population is further grouped into two which are vaccinated group and unvaccinated group. The behavior of the epidemic is investigated through analysing the equilibrium of the model. The result shows that administering vaccine to the susceptible population contributes to the reduction of the tuberculosis epidemic rate.

  9. Fungal effector proteins: past, present and future

    NARCIS (Netherlands)

    Wit, de P.J.G.M.; Mehrabi, R.; Burg, van den H.A.; Stergiopoulos, I.

    2009-01-01

    The pioneering research of Harold Flor on flax and the flax rust fungus culminated in his gene-for-gene hypothesis. It took nearly 50 years before the first fungal avirulence (Avr) gene in support of his hypothesis was cloned. Initially, fungal Avr genes were identified by reverse genetics and

  10. A novel class of fungal lipoxygenases

    NARCIS (Netherlands)

    Heshof, R.; Jylhä, S.; Haarmann, T.; Jørgensen, A.L.W.; Dalsgaard, T.K.; Graaff, de L.H.

    2014-01-01

    Lipoxygenases (LOXs) are well-studied enzymes in plants and mammals. However, fungal LOXs are less studied. In this study, we have compared fungal LOX protein sequences to all known characterized LOXs. For this, a script was written using Shell commands to extract sequences from the NCBI database

  11. Fungal infection knowledge gap in Ethiopia

    African Journals Online (AJOL)

    EPHA USER33

    receiving immunosuppressive therapy, and patients with chronic obstructive lung disease (1). Fungi also play a role in allergic fungal disease such as allergic broncho- pulmonary Aspergilosis (ABPA) and chronic or deep tissue infections. The laboratory diagnosis of fungal infection starts with a simple potassium hydroxide.

  12. Clinical consideration of fungal paranasal sinusitis

    International Nuclear Information System (INIS)

    Okuni, Tsuyoshi; Asakura, Koji; Homma, Tomo; Kawaguchi, Ryuichi; Ishikawa, Tadataka; Yamazaki, Norikazu; Himi, Tetsuo

    2008-01-01

    Fungal paranasal sinusitis is included in the differential diagnosis of unilateral paranasal lesion. Recently the incidence of fungal paranasal sinusitis has been increasing. We reviewed 24 patients (9 males and 15 females) with fungal paranasal sinusitis treated at Muroran City Hospital between January 2001 and May 2006, and clinical presentation and CT findings with those of 56 patients (36 males and 20 females) with chronic unilateral sinusitis. Fungal sinusitis patients ranged in age from 45 to 87, and the average age was 65.9 years old. In contrast, the age of chronic sinusitis patients ranged from 24 to 83, and the average age was 54.4 years old. The chief complaint of both fungal sinusitis and chronic sinusitis included rhinorrhea, nasal obstruction and post nasal discharge. CT exam was performed in all patients. In 23 cases of paranasal fungal sinusitis and 54 cases of chronic sinusitis the findings involved the maxillary sinus. The most common observation (69.6%) was bone density within the affected sinus in fungal sinusitis. However, only 2 cases of chronic sinusitis (3.9%) showed calcification. All cases of fungal sinusitis were diagnosed by pathological examinations. Most cases were proved to be aspergillus, while only one case was mucor. We treated all cases surgically, 18 cases underwent Caldwell-Luc's procedure and 5 cases underwent endoscopic sinus surgery under local anesthesia. (author)

  13. Fungal cultivation on glass-beads

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, Henriette

    Transcription of various bioactive compounds and enzymes are dependent on fungal cultivation method. In this study we cultivate Fusarium graminearum and Fusarium solani on glass-beads with liquid media in petri dishes as an easy and inexpensive cultivation method, that resembles in secondary...... metabolite production to agar-cultivation but with an easier and more pure RNA-extraction of total fungal mycelia....

  14. Altered immunity in crowded locust reduced fungal (Metarhizium anisopliae pathogenesis.

    Directory of Open Access Journals (Sweden)

    Yundan Wang

    2013-01-01

    Full Text Available The stress of living conditions, similar to infections, alters animal immunity. High population density is empirically considered to induce prophylactic immunity to reduce the infection risk, which was challenged by a model of low connectivity between infectious and susceptible individuals in crowded animals. The migratory locust, which exhibits polyphenism through gregarious and solitary phases in response to population density and displays different resistance to fungal biopesticide (Metarhizium anisopliae, was used to observe the prophylactic immunity of crowded animals. We applied an RNA-sequencing assay to investigate differential expression in fat body samples of gregarious and solitary locusts before and after infection. Solitary locusts devoted at least twice the number of genes for combating M. anisopliae infection than gregarious locusts. The transcription of immune molecules such as pattern recognition proteins, protease inhibitors, and anti-oxidation proteins, was increased in prophylactic immunity of gregarious locusts. The differentially expressed transcripts reducing gregarious locust susceptibility to M. anisopliae were confirmed at the transcriptional and translational level. Further investigation revealed that locust GNBP3 was susceptible to proteolysis while GNBP1, induced by M. anisopliae infection, resisted proteolysis. Silencing of gnbp3 by RNAi significantly shortened the life span of gregarious locusts but not solitary locusts. By contrast, gnbp1 silencing did not affect the life span of both gregarious and solitary locusts after M. anisopliae infection. Thus, the GNBP3-dependent immune responses were involved in the phenotypic resistance of gregarious locusts to fungal infection, but were redundant in solitary locusts. Our results indicated that gregarious locusts prophylactically activated upstream modulators of immune cascades rather than downstream effectors, preferring to quarantine rather than eliminate pathogens to

  15. Histone Acetylation in Fungal Pathogens of Plants

    Directory of Open Access Journals (Sweden)

    Junhyun Jeon

    2014-03-01

    Full Text Available Acetylation of histone lysine residues occurs in different organisms ranging from yeast to plants and mammals for the regulation of diverse cellular processes. With the identification of enzymes that create or reverse this modification, our understanding on histone acetylation has expanded at an amazing pace during the last two decades. In fungal pathogens of plants, however, the importance of such modification has only just begun to be appreciated in the recent years and there is a dearth of information on how histone acetylation is implicated in fungal pathogenesis. This review covers the current status of research related to histone acetylation in plant pathogenic fungi and considers relevant findings in the interaction between fungal pathogens and host plants. We first describe the families of histone acetyltransferases and deacetylases. Then we provide the cases where histone acetylation was investigated in the context of fungal pathogenesis. Finally, future directions and perspectives in epigenetics of fungal pathogenesis are discussed.

  16. Soil fungal community responses to global changes

    DEFF Research Database (Denmark)

    Haugwitz, Merian Skouw

    Global change will affect the functioning and structure of terrestrial ecosystems and since soil fungi are key players in organic matter decomposition and nutrient turnover, shifts in fungal community composition might have a strong impact on soil functioning. The main focus of this thesis...... was therefore to investigate the impact of global environmental changes on soil fungal communities in a temperate and subartic heath ecosystem. The objective was further to determine global change effects on major functional groups of fungi and analyze the influence of fungal community changes on soil carbon...... and nutrient availability and storage. By combining molecular methods such as 454 pyrosequencing and quantitative PCR of fungal ITS amplicons with analyses of soil enzymes, nutrient pools of carbon, nitrogen and phosphorus we were able to characterize soil fungal communities as well as their impact on nutrient...

  17. Sensitivity analysis of an individual-based model for simulation of influenza epidemics.

    Directory of Open Access Journals (Sweden)

    Elaine O Nsoesie

    Full Text Available Individual-based epidemiology models are increasingly used in the study of influenza epidemics. Several studies on influenza dynamics and evaluation of intervention measures have used the same incubation and infectious period distribution parameters based on the natural history of influenza. A sensitivity analysis evaluating the influence of slight changes to these parameters (in addition to the transmissibility would be useful for future studies and real-time modeling during an influenza pandemic.In this study, we examined individual and joint effects of parameters and ranked parameters based on their influence on the dynamics of simulated epidemics. We also compared the sensitivity of the model across synthetic social networks for Montgomery County in Virginia and New York City (and surrounding metropolitan regions with demographic and rural-urban differences. In addition, we studied the effects of changing the mean infectious period on age-specific epidemics. The research was performed from a public health standpoint using three relevant measures: time to peak, peak infected proportion and total attack rate. We also used statistical methods in the design and analysis of the experiments. The results showed that: (i minute changes in the transmissibility and mean infectious period significantly influenced the attack rate; (ii the mean of the incubation period distribution appeared to be sufficient for determining its effects on the dynamics of epidemics; (iii the infectious period distribution had the strongest influence on the structure of the epidemic curves; (iv the sensitivity of the individual-based model was consistent across social networks investigated in this study and (v age-specific epidemics were sensitive to changes in the mean infectious period irrespective of the susceptibility of the other age groups. These findings suggest that small changes in some of the disease model parameters can significantly influence the uncertainty

  18. INCIDENCE OF FUNGAL ELEMENTS IN SINONASAL POLYPOSIS

    Directory of Open Access Journals (Sweden)

    Santhosh G. S

    2016-12-01

    Full Text Available BACKGROUND Nasal polyposis is a disease entity characterised by formation of pseudoedema of sinonasal mucus membrane progressing to form polyps. It presents clinically with nasal obstruction and fleshy masses in the nasal cavity. The nasal mucosa reacts to formation of polypi in allergic fungal sinusitis also. The present study is an attempt to demonstrate possible fungal elements from the polypi removed during surgery by KOH study and HPE study. The aim of the study is to find out the incidence of fungal elements in sinonasal polyposis. MATERIALS AND METHODS 50 patients attending the ENT OPD for nasal obstruction and showing polypi on anterior rhinoscopy were selected. All the patients were subjected to surgery and specimens collected were subjected to KOH study and histopathology to demonstrate fungal elements. RESULTS Among 50 patients, the age range was from 9-57 years; mean age- 36.46 years. The male-to-female ratio was 1.5:1. Deviated nasal septum was found in 38% of patients. Among the unilateral cases, 47% were antrochoanal polyps and 53% were ethmoid polyps. Out of 50 patients, only 3 specimens were positive for fungal elements with KOH study and only 2 cases with fungal culture. Thus, the incidence of fungal elements in sinonasal polyposis was 6%. CONCLUSION The incidence of fungal elements in sinonasal polyposis was 6%. Histopathological examination of polypectomy specimen was negative for invasive fungal disease and showed inflammatory changes only. There is no difference in the detection of the presence of fungal by two methods.

  19. Social sciences and humanities contribution to tackle the obesity epidemic

    DEFF Research Database (Denmark)

    Holm, Lotte; Sandøe, Peter; Nielsen, Morten Ebbe Juul

    for identifying, describing, and discussing future potential in obesity research, to establish new and to nurture existing networks and collaborations between researchers across the social sciences and humanities and the natural sciences with an interest in obesity research, and thereby to mobilise significant......To address the obesity epidemic, European researchers need to come together to find the best solutions and use their combined knowledge to provide the most innovative research ideas. By gathering more than 50 researchers and stakeholders from around Europe, we took an important step towards...... establishing strong networks and building bridges between the natural sciences and social sciences and humanities that can address obesity as a complex societal challenge and help minimise the gap between research, markets, and citizens. The objectives of the workshop were to create a cross‐European forum...

  20. Chapter 8: Invasive fungal rhinosinusitis.

    Science.gov (United States)

    Duggal, Praveen; Wise, Sarah K

    2013-01-01

    Invasive fungal rhinosinusitis (IFRS) is a disease of the paranasal sinuses and nasal cavity that typically affects immunocompromised patients in the acute fulminant form. Early symptoms can often mimic rhinosinusitis, while late symptoms can cause significant morbidity and mortality. Swelling and mucosal thickening can quickly progress to pale or necrotic tissue in the nasal cavity and sinuses, and the disease can rapidly spread and invade the palate, orbit, cavernous sinus, cranial nerves, skull base, carotid artery, and brain. IFRS can be life threatening if left undiagnosed or untreated. While the acute fulminant form of IFRS is the most rapidly progressive and destructive, granulomatous and chronic forms also exist. Diagnosis of IFRS often mandates imaging studies in conjunction with clinical, endoscopic, and histopathological examination. Treatment of IFRS consists of reversing the underlying immunosuppression, antifungal therapy, and aggressive surgical debridement. With early diagnosis and treatment, IFRS can be treated and increase patient survival.

  1. Disadvantaged Social Groups and the Cigarette Epidemic: Limits of the Diffusion of Innovations Vision

    Directory of Open Access Journals (Sweden)

    Myriam Khlat

    2016-12-01

    Full Text Available The original four-stage model of the cigarette epidemic has been extended with diffusion of innovations theory to reflect socio-economic differences in cigarette use. Recently, two revisions of the model have been proposed: (1 separate analysis of the epidemic stages for men and women, in order to improve generalization to developing countries, and; (2 addition of a fifth stage to the smoking epidemic, in order to account for the persistence of smoking in disadvantaged social groups. By developing a cohort perspective spanning a 35-year time period in France and the USA, we uncover distinctive features which challenge the currently held vision on the evolution of smoking inequalities within the framework of the cigarette epidemic. We argue that the reason for which the model may not be fit to the lower educated is that the imitation mechanism underlying the diffusion of innovations works well with regard to adoption of the habit, but is much less relevant with regard to its rejection. Based on those observations, we support the idea that the nature and timing of the epidemic differs enough to treat the stages separately for high and low education groups, and discuss policy implications.

  2. Scale-dependent climatic drivers of human epidemics in ancient China.

    Science.gov (United States)

    Tian, Huidong; Yan, Chuan; Xu, Lei; Büntgen, Ulf; Stenseth, Nils C; Zhang, Zhibin

    2017-12-05

    A wide range of climate change-induced effects have been implicated in the prevalence of infectious diseases. Disentangling causes and consequences, however, remains particularly challenging at historical time scales, for which the quality and quantity of most of the available natural proxy archives and written documentary sources often decline. Here, we reconstruct the spatiotemporal occurrence patterns of human epidemics for large parts of China and most of the last two millennia. Cold and dry climate conditions indirectly increased the prevalence of epidemics through the influences of locusts and famines. Our results further reveal that low-frequency, long-term temperature trends mainly contributed to negative associations with epidemics, while positive associations of epidemics with droughts, floods, locusts, and famines mainly coincided with both higher and lower frequency temperature variations. Nevertheless, unstable relationships between human epidemics and temperature changes were observed on relatively smaller time scales. Our study suggests that an intertwined, direct, and indirect array of biological, ecological, and societal responses to different aspects of past climatic changes strongly depended on the frequency domain and study period chosen.

  3. Epidemic spreading in weighted scale-free networks with community structure

    International Nuclear Information System (INIS)

    Chu, Xiangwei; Guan, Jihong; Zhang, Zhongzhi; Zhou, Shuigeng

    2009-01-01

    Many empirical studies reveal that the weights and community structure are ubiquitous in various natural and artificial networks. In this paper, based on the SI disease model, we investigate the epidemic spreading in weighted scale-free networks with community structure. Two exponents, α and β, are introduced to weight the internal edges and external edges, respectively; and a tunable probability parameter q is also introduced to adjust the strength of community structure. We find the external weighting exponent β plays a much more important role in slackening the epidemic spreading and reducing the danger brought by the epidemic than the internal weighting exponent α. Moreover, a novel result we find is that the strong community structure is no longer helpful for slackening the danger brought by the epidemic in the weighted cases. In addition, we show the hierarchical dynamics of the epidemic spreading in the weighted scale-free networks with communities which is also displayed in the famous BA scale-free networks

  4. Gendered Epidemics and Systems of Power in Africa: A Feminist ...

    African Journals Online (AJOL)

    creating an environment that increases women's vulnerability to epidemics. The article ..... to epidemics because rarely, if ever, does a single reason account for their vulnerability. ... life as a young woman. Contraception gave her freedom from.

  5. the south african hiv epidemic, reflected by nine provincial ...

    African Journals Online (AJOL)

    the distribution and trend of the HIV epidemic in each of the ... The exponential model significantly explains the HIV epidemics in the .... such a curve is considered to be made up of three. October 199 ..... Ut: Quantitative Forecasting Methods.

  6. Phylogenetics of the Danish HIV epidemic

    DEFF Research Database (Denmark)

    Audelin, Anne Margrethe; Cowan, Susan A; Obel, Niels

    2013-01-01

    BACKGROUND:: In Denmark 300 new individuals are diagnosed with HIV every year, despite decades of public health campaigns aimed to raise awareness of potential risk behaviour for HIV transmission. It is important to identify the driving forces of the epidemic, to enable more targeted campaigns...

  7. CDC Vital Signs: Today's Heroin Epidemic

    Science.gov (United States)

    ... the MMWR Science Clips Today’s Heroin Epidemic More people at risk, multiple drugs abused Language: English (US) Español Recommend on Facebook Tweet Share Compartir On This Page Overview Problem Infographics What Can Be Done Issue Details Overview Heroin use has increased across the US among men and ...

  8. [A prognostic model of a cholera epidemic].

    Science.gov (United States)

    Boev, B V; Bondarenko, V M; Prokop'eva, N V; San Román, R T; Raygoza-Anaya, M; García de Alba, R

    1994-01-01

    A new model for the prognostication of cholera epidemic on the territory of a large city is proposed. This model reflects the characteristic feature of contacting infection by sensitive individuals due to the preservation of Vibrio cholerae in their water habitat. The mathematical model of the epidemic quantitatively reflects the processes of the spread of infection by kinetic equations describing the interaction of the streams of infected persons, the causative agents and susceptible persons. The functions and parameters of the model are linked with the distribution of individuals according to the duration of the incubation period and infectious process, as well as the period of asymptomatic carrier state. The computer realization of the model by means of IBM PC/AT made it possible to study the cholera epidemic which took place in Mexico in 1833. The verified model of the cholera epidemic was used for the prognostication of the possible spread of this infection in Guadalajara, taking into account changes in the epidemiological situation and the size of the population, as well as improvements in sanitary and hygienic conditions, in the city.

  9. The Prescription Opioid Pain Medication Overdose Epidemic

    Centers for Disease Control (CDC) Podcasts

    2016-04-19

    Overdose related to prescription opioids has become an epidemic. This podcast discusses the risks of this type of drug sometimes used to treat pain, and how to protect yourself. .  Created: 4/19/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 4/19/2016.

  10. Alternative risk financing instruments for swine epidemics

    NARCIS (Netherlands)

    Meuwissen, M.P.M.; Asseldonk, van M.A.P.M.; Huirne, R.B.M.

    2003-01-01

    Swine epidemics can have very large devastating financial consequences. Governments generally bear the direct losses, such as the value of destroyed animals. Consequential losses, such as the losses resulting from empty buildings and movement standstills, are completely borne by the farmers (and

  11. A Weighted Configuration Model and Inhomogeneous Epidemics

    Science.gov (United States)

    Britton, Tom; Deijfen, Maria; Liljeros, Fredrik

    2011-12-01

    A random graph model with prescribed degree distribution and degree dependent edge weights is introduced. Each vertex is independently equipped with a random number of half-edges and each half-edge is assigned an integer valued weight according to a distribution that is allowed to depend on the degree of its vertex. Half-edges with the same weight are then paired randomly to create edges. An expression for the threshold for the appearance of a giant component in the resulting graph is derived using results on multi-type branching processes. The same technique also gives an expression for the basic reproduction number for an epidemic on the graph where the probability that a certain edge is used for transmission is a function of the edge weight (reflecting how closely `connected' the corresponding vertices are). It is demonstrated that, if vertices with large degree tend to have large (small) weights on their edges and if the transmission probability increases with the edge weight, then it is easier (harder) for the epidemic to take off compared to a randomized epidemic with the same degree and weight distribution. A recipe for calculating the probability of a large outbreak in the epidemic and the size of such an outbreak is also given. Finally, the model is fitted to three empirical weighted networks of importance for the spread of contagious diseases and it is shown that R 0 can be substantially over- or underestimated if the correlation between degree and weight is not taken into account.

  12. Epidemic spreading on preferred degree adaptive networks.

    Science.gov (United States)

    Jolad, Shivakumar; Liu, Wenjia; Schmittmann, B; Zia, R K P

    2012-01-01

    We study the standard SIS model of epidemic spreading on networks where individuals have a fluctuating number of connections around a preferred degree κ. Using very simple rules for forming such preferred degree networks, we find some unusual statistical properties not found in familiar Erdös-Rényi or scale free networks. By letting κ depend on the fraction of infected individuals, we model the behavioral changes in response to how the extent of the epidemic is perceived. In our models, the behavioral adaptations can be either 'blind' or 'selective'--depending on whether a node adapts by cutting or adding links to randomly chosen partners or selectively, based on the state of the partner. For a frozen preferred network, we find that the infection threshold follows the heterogeneous mean field result λ(c)/μ = / and the phase diagram matches the predictions of the annealed adjacency matrix (AAM) approach. With 'blind' adaptations, although the epidemic threshold remains unchanged, the infection level is substantially affected, depending on the details of the adaptation. The 'selective' adaptive SIS models are most interesting. Both the threshold and the level of infection changes, controlled not only by how the adaptations are implemented but also how often the nodes cut/add links (compared to the time scales of the epidemic spreading). A simple mean field theory is presented for the selective adaptations which capture the qualitative and some of the quantitative features of the infection phase diagram.

  13. [Notes about other epidemics in Colonial Chile].

    Science.gov (United States)

    Laval, Enrique

    2015-10-01

    In chronicles or in the historiography of the Colony in Chile there are few references about epidemics different to smallpox; like typhus, typhoid fever, dysentery, etc. Almost all, fast spreading in the country and some with high lethality, which led to overflowing the capacity of hospitals in the Chilean colonial period.

  14. Epidemic spreading through direct and indirect interactions.

    Science.gov (United States)

    Ganguly, Niloy; Krueger, Tyll; Mukherjee, Animesh; Saha, Sudipta

    2014-09-01

    In this paper we study the susceptible-infected-susceptible epidemic dynamics, considering a specialized setting where popular places (termed passive entities) are visited by agents (termed active entities). We consider two types of spreading dynamics: direct spreading, where the active entities infect each other while visiting the passive entities, and indirect spreading, where the passive entities act as carriers and the infection is spread via them. We investigate in particular the effect of selection strategy, i.e., the way passive entities are chosen, in the spread of epidemics. We introduce a mathematical framework to study the effect of an arbitrary selection strategy and derive formulas for prevalence, extinction probabilities, and epidemic thresholds for both indirect and direct spreading. We also obtain a very simple relationship between the extinction probability and the prevalence. We pay special attention to preferential selection and derive exact formulas. The analysis reveals that an increase in the diversity in the selection process lowers the epidemic thresholds. Comparing the direct and indirect spreading, we identify regions in the parameter space where the prevalence of the indirect spreading is higher than the direct one.

  15. Cholera Epidemic Control | Zachariah | Malawi Medical Journal

    African Journals Online (AJOL)

    Malawi Medical Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 13, No 1 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Cholera Epidemic Control. R Zachariah. Full Text: EMAIL FREE ...

  16. Social epidemics in the aftermath of disasters.

    NARCIS (Netherlands)

    IJzermans, C.J.

    2002-01-01

    Issue/problem: After disasters, terrorist attacks and wars social epidemics of medically unexplained physical symptoms/syndromes (ups) are often seen. In modern times people feel more vulnerable and especially under pressure of those incidents, everyday symptoms are interpreted as disease and

  17. Fungal infection in organ transplant patients.

    Science.gov (United States)

    Hong, Wei; Wen, Hai; Liao, Wanqing

    2003-09-01

    To review the characteristics and evolution of the fungal spectrum, and the risk factors causing fungal infection, and to make progress in diagnosing fungal infection after organ transplantation. An English-language literature search (MEDLINE 1990 - 2000) and bibliographic review of textbooks and review articles. Twenty-three articles were selected from the literature that specifically addressed the stated purpose. Fungal infections in organ transplant patients were generally divided into two types: (1) disseminated primary or reactivation infection with one of the geographically restricted systemic mycoses; (2) opportunistic infection by fungal species that rarely cause invasive infection in normal hosts. The risk factors of fungal infection after a transplant can be evaluated and predicted according to the organ recipient's conditions before, during and after the transplant. Progress in early diagnostic methods during the past 10 years has mainly revolved around two aspects, culture and non-culture. It is important to undertake a systemic evaluation on the condition of the organ recipient before, during and after a transplant; should any risk factor for fungal infection be suspected, diagnosis should be made as early as possible by employing mycological techniques including culture and non-culture methods.

  18. Invasive Fungal Infections Secondary to Traumatic Injury

    Directory of Open Access Journals (Sweden)

    Ryan Kronen

    2017-09-01

    Full Text Available Invasive fungal infection (IFI is a rare but serious complication of traumatic injury. The purpose of this article is to review the epidemiology, natural history, mycology, risk factors, diagnosis, treatment, and outcomes associated with post-traumatic IFI in military and civilian populations. The epidemiology of post-traumatic IFI is poorly characterized, but incidence appears to be rising. Patients often suffer from severe injuries and require extensive medical interventions. Fungi belonging to the order Mucorales are responsible for most post-traumatic IFI in both civilian and military populations. Risk factors differ between these cohorts but include specific injury patterns and comorbidities. Diagnosis of post-traumatic IFI typically follows positive laboratory results in the appropriate clinical context. The gold standard of treatment is surgical debridement in addition to systemic antifungal therapy. Patients with post-traumatic IFI may be at greater risk of amputation, delays in wound healing, hospital complications, and death as compared to trauma patients who do not develop IFI. More research is needed to understand the factors surrounding the development and management of post-traumatic IFI to reduce the significant morbidity and mortality associated with this disease.

  19. Fungal Laccases Degradation of Endocrine Disrupting Compounds

    Directory of Open Access Journals (Sweden)

    Gemma Macellaro

    2014-01-01

    Full Text Available Over the past decades, water pollution by trace organic compounds (ng/L has become one of the key environmental issues in developed countries. This is the case of the emerging contaminants called endocrine disrupting compounds (EDCs. EDCs are a new class of environmental pollutants able to mimic or antagonize the effects of endogenous hormones, and are recently drawing scientific and public attention. Their widespread presence in the environment solicits the need of their removal from the contaminated sites. One promising approach to face this challenge consists in the use of enzymatic systems able to react with these molecules. Among the possible enzymes, oxidative enzymes are attracting increasing attention because of their versatility, the possibility to produce them on large scale, and to modify their properties. In this study five different EDCs were treated with four different fungal laccases, also in the presence of both synthetic and natural mediators. Mediators significantly increased the efficiency of the enzymatic treatment, promoting the degradation of substrates recalcitrant to laccase oxidation. The laccase showing the best performances was chosen to further investigate its oxidative capabilities against micropollutant mixtures. Improvement of enzyme performances in nonylphenol degradation rate was achieved through immobilization on glass beads.

  20. The role of plant mycorrhizal type and status in modulating the relationship between plant and arbuscular mycorrhizal fungal communities.

    Science.gov (United States)

    Neuenkamp, Lena; Moora, Mari; Öpik, Maarja; Davison, John; Gerz, Maret; Männistö, Minna; Jairus, Teele; Vasar, Martti; Zobel, Martin

    2018-01-25

    Interactions between communities of plants and arbuscular mycorrhizal (AM) fungi shape fundamental ecosystem properties. Experimental evidence suggests that compositional changes in plant and AM fungal communities should be correlated, but empirical data from natural ecosystems are scarce. We investigated the dynamics of covariation between plant and AM fungal communities during three stages of grassland succession, and the biotic and abiotic factors shaping these dynamics. Plant communities were characterised using vegetation surveys. AM fungal communities were characterised by 454-sequencing of the small subunit rRNA gene and identification against the AM fungal reference database MaarjAM. AM fungal abundance was estimated using neutral-lipid fatty acids (NLFAs). Multivariate correlation analysis (Procrustes) revealed a significant relationship between plant and AM fungal community composition. The strength of plant-AM fungal correlation weakened during succession following cessation of grassland management, reflecting changes in the proportion of plants exhibiting different AM status. Plant-AM fungal correlation was strong when the abundance of obligate AM plants was high, and declined as the proportion of facultative AM plants increased. We conclude that the extent to which plants rely on AM symbiosis can determine how tightly communities of plants and AM fungi are interlinked, regulating community assembly of both symbiotic partners. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  1. Economic cost and burden of dengue during epidemics and non-epidemic years in Taiwan

    Directory of Open Access Journals (Sweden)

    Dih-Ling Luh

    2018-03-01

    Full Text Available Background: Determining the disease and economic burden of dengue is critical for the allocation of public health resources. Several studies have used disability-adjusted life-years (DALYs to estimate the disease burden of dengue in different regions. However, there are no published studies discussing the estimates of dengue-related economic and disease burden specifically in Taiwan. Objectives: We assessed the economic cost and disease burden of dengue infections in Taiwan for the period 1998–2014, and compared these during epidemic and non-epidemic years. Methods: We estimated the annual DALYs per million population using the disability weights for dengue fever (DF, dengue hemorrhagic fever (DHF, dengue shock syndrome (DSS, and death cases. Economic costs were estimated and divided into direct (medical costs and indirect costs (lost work days and caregiver fees. Results: For the period 1998–2014, a mean of 115.3 (range: 6.3–934.3 DALYs per million population annually were lost to dengue. In epidemic years, direct costs associated with dengue resulted mostly from hospitalization (86.09%, emergency (7.77%, outpatient (6.10%, and drug costs (0.03%. For indirect costs, lost productivity due to death (70.76% was the dominant contributor. Overall, the costs were 12.3 times higher in epidemic years than in non-epidemic years (Wilcoxon rank sum test, p < 0.05. Conclusions: This study is the first to evaluate the economic costs and disease burden of dengue infections for this period in Taiwan, and reveals significant differences in economic impact between epidemic and non-epidemic years. Keywords: Economic cost of disease, Disease burden, Disability-adjusted life years (DALYs, Dengue, Epidemic

  2. Ecological succession reveals potential signatures of marine-terrestrial transition in salt marsh fungal communities.

    Science.gov (United States)

    Dini-Andreote, Francisco; Pylro, Victor Satler; Baldrian, Petr; van Elsas, Jan Dirk; Salles, Joana Falcão

    2016-08-01

    Marine-to-terrestrial transition represents one of the most fundamental shifts in microbial life. Understanding the distribution and drivers of soil microbial communities across coastal ecosystems is critical given the roles of microbes in soil biogeochemistry and their multifaceted influence on landscape succession. Here, we studied the fungal community dynamics in a well-established salt marsh chronosequence that spans over a century of ecosystem development. We focussed on providing high-resolution assessments of community composition, diversity and ecophysiological shifts that yielded patterns of ecological succession through soil formation. Notably, despite containing 10- to 100-fold lower fungal internal transcribed spacer abundances, early-successional sites revealed fungal richnesses comparable to those of more mature soils. These newly formed sites also exhibited significant temporal variations in β-diversity that may be attributed to the highly dynamic nature of the system imposed by the tidal regime. The fungal community compositions and ecophysiological assignments changed substantially along the successional gradient, revealing a clear signature of ecological replacement and gradually transforming the environment from a marine into a terrestrial system. Moreover, distance-based linear modelling revealed soil physical structure and organic matter to be the best predictors of the shifts in fungal β-diversity along the chronosequence. Taken together, our study lays the basis for a better understanding of the spatiotemporally determined fungal community dynamics in salt marshes and highlights their ecophysiological traits and adaptation in an evolving ecosystem.

  3. Fungal colonization of air-conditioning systems

    Directory of Open Access Journals (Sweden)

    Ljaljević-Grbić Milica

    2008-01-01

    Full Text Available Fungi have been implicated as quantitatively the most important bioaerosol component of indoor air associated with contaminated air-conditioning systems. rarely, indoor fungi may cause human infections, but more commonly allergenic responses ranging from pneumonitis to asthma-like symptoms. From all air conditioner filters analyzed, 16 fungal taxa were isolated and identified. Aspergillus fumigatus causes more lethal infections worldwide than any other mold. Air-conditioning filters that adsorb moisture and volatile organics appear to provide suitable substrates for fungal colonization. It is important to stress that fungal colonization of air-conditioning systems should not be ignored, especially in hospital environments.

  4. Fungal infections in neutropenic cancer patients

    International Nuclear Information System (INIS)

    Parvez, T.

    2003-01-01

    Invasive fungal infections are important causes of morbidity and mortality in cancer patients with prolonged neutropenia following chemotherapy. Recent trends indicate a change toward infections by Aspergillus species, non-albicans species of Candida, and previously uncommon fungal pathogens. These have decreased susceptibility to current antifungal agents. In the last decade there has been much effort to find solutions for these changing trends. This article reviews current approaches to prevention and treatment of opportunistic fungal infections in postchemotherapy neutropenic patients and discussion future antifungal approaches and supportive methods. (author)

  5. Transferring the Malaria Epidemic Prediction Model to Users in East ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Transferring the Malaria Epidemic Prediction Model to Users in East Africa. In the highlands of East Africa, epidemic malaria is an emerging climate-related hazard that urgently needs addressing. Malaria incidence increased by 337% during the 1987 epidemic in Rwanda. In Tanzania, Uganda and Kenya, malaria incidence ...

  6. Women and AIDS in Zimbabwe: the making of an epidemic.

    Science.gov (United States)

    Bassett, M T; Mhloyi, M

    1991-01-01

    As the AIDS epidemic in Africa assumes major proportions, the need to understand the social context in which heterosexual transmission occurs takes on urgent importance. In this article we explore how the intersection of traditional culture with the colonial legacy and present-day political economy has influenced family structure and sexual relations, and particularly the social position of women. Drawing on Zimbabwe's historical experience, we show how land expropriation, rural impoverishment, and the forcible introduction of male migrant labor fostered new patterns of sexual relations, characterized by multiple partners. Traditional patriarchal values reinterpreted in European law resulted in further subjugation of women as even limited rights to ownership were withdrawn. For many women, sexual relations with men, either within marriage (for the majority) or outside, become inextricably linked to economic and social survival. In this setting, all sexually transmitted diseases became rampant, including genital ulcer, which facilitates transmission of the human immunodeficiency virus (HIV). Intervention programs to halt the spread of AIDS need to take into the account the epidemic's historical roots and social nature. For example, efforts to reduce risk of HIV transmission should seek to expand women's limited options, both technically (e.g., by providing alternatives to condoms) and socially (e.g., by promoting employment).

  7. Outbreak or Epidemic? How Obama's Language Choice Transformed the Ebola Outbreak Into an Epidemic.

    Science.gov (United States)

    Gesser-Edelsburg, Anat; Shir-Raz, Yaffa; Bar-Lev, Oshrat Sassoni; James, James J; Green, Manfred S

    2016-08-01

    Our aim was to examine in what terms leading newspapers' online sites described the current Ebola crisis. We employed a quantitative content analysis of terms attributed to Ebola. We found and analyzed 582 articles published between March 23 and September 30, 2014, on the online websites of 3 newspapers: The New York Times, Daily Mail, and Ynet. Our theoretical framework drew from the fields of health communication and emerging infectious disease communication, including such concepts as framing media literacy, risk signatures, and mental models. We found that outbreak and epidemic were used interchangeably in the articles. From September 16, 2014, onward, epidemic predominated, corresponding to when President Barack Obama explicitly referred to Ebola as an epidemic. Prior to Obama's speech, 86.8% of the articles (323) used the term outbreak and only 8.6% (32) used the term epidemic. Subsequently, both terms were used almost the same amount: 53.8% of the articles (113) used the term outbreak and 53.3% (112) used the term epidemic. Effective communication is crucial during public health emergencies such as Ebola, because language framing affects the decision-making process of social judgments and actions. The choice of one term (outbreak) over another (epidemic) can create different conceptualizations of the disease, thereby influencing the risk signature. (Disaster Med Public Health Preparedness. 2016;10:669-673).

  8. Integrated travel network model for studying epidemics: Interplay between journeys and epidemic

    Science.gov (United States)

    Ruan, Zhongyuan; Wang, Chaoqing; Ming Hui, Pak; Liu, Zonghua

    2015-06-01

    The ease of travelling between cities has contributed much to globalization. Yet, it poses a threat on epidemic outbreaks. It is of great importance for network science and health control to understand the impact of frequent journeys on epidemics. We stress that a new framework of modelling that takes a traveller’s viewpoint is needed. Such integrated travel network (ITN) model should incorporate the diversity among links as dictated by the distances between cities and different speeds of different modes of transportation, diversity among nodes as dictated by the population and the ease of travelling due to infrastructures and economic development of a city, and round-trip journeys to targeted destinations via the paths of shortest travel times typical of human journeys. An example is constructed for 116 cities in China with populations over one million that are connected by high-speed train services and highways. Epidemic spread on the constructed network is studied. It is revealed both numerically and theoretically that the traveling speed and frequency are important factors of epidemic spreading. Depending on the infection rate, increasing the traveling speed would result in either an enhanced or suppressed epidemic, while increasing the traveling frequency enhances the epidemic spreading.

  9. Parameter Scaling for Epidemic Size in a Spatial Epidemic Model with Mobile Individuals.

    Directory of Open Access Journals (Sweden)

    Chiyori T Urabe

    Full Text Available In recent years, serious infectious diseases tend to transcend national borders and widely spread in a global scale. The incidence and prevalence of epidemics are highly influenced not only by pathogen-dependent disease characteristics such as the force of infection, the latent period, and the infectious period, but also by human mobility and contact patterns. However, the effect of heterogeneous mobility of individuals on epidemic outcomes is not fully understood. Here, we aim to elucidate how spatial mobility of individuals contributes to the final epidemic size in a spatial susceptible-exposed-infectious-recovered (SEIR model with mobile individuals in a square lattice. After illustrating the interplay between the mobility parameters and the other parameters on the spatial epidemic spreading, we propose an index as a function of system parameters, which largely governs the final epidemic size. The main contribution of this study is to show that the proposed index is useful for estimating how parameter scaling affects the final epidemic size. To demonstrate the effectiveness of the proposed index, we show that there is a positive correlation between the proposed index computed with the real data of human airline travels and the actual number of positive incident cases of influenza B in the entire world, implying that the growing incidence of influenza B is attributed to increased human mobility.

  10. Fungal/mycotic diseases of poultry-diagnosis, treatment and control: a review.

    Science.gov (United States)

    Dhama, Kuldeep; Chakraborty, Sandip; Verma, Amit Kumar; Tiwari, Ruchi; Barathidasan, Rajamani; Kumar, Amit; Singh, Shambhu Dayal

    2013-12-01

    Fungal/mycotic diseases cause significant economic losses to the poultry industry either due to their direct infectious nature or due to production of mycotoxins, the secondary fungal metabolites produced in grains or poultry feed. Several fungi have created havoc in the poultry industry and some of them cause direct harm to human health due to their zoonotic implications. They are responsible for high morbidity and mortality, especially in young birds and cause stunted growth and diarrhea; and fatal encephalitis. Mycotic dermatitis is a possible health hazard associated with poultry houses. Mycotoxins are the leading cause of producing immunosuppression in birds, which makes them prone to several bacterial and viral infections leading to huge economic losses to the poultry industry. In comparison to bacterial and viral diseases, advances in diagnosis, treatment, prevention and control of fungal diseases in poultry has not taken much attention. Recently, molecular biological tools have been explored for rapid and accurate diagnosis of important fungal infections. Effective prevention and control measures include: appropriate hygiene, sanitation and disinfection, strict biosecurity programme and regular surveillance/monitoring of fungal infections as well as following judicious use of anti-fungal drugs. Precautionary measures during crop production, harvesting and storing and in feed mixing plants can help to check the fungal infections including health hazards of mycotoxins/mycotoxicosis. The present review describes the fungal pathogens causing diseases in poultry/birds, especially focusing to their diagnosis, prevention and control measures, which would help in formulating appropriate strategies to have a check and control on these unwanted troubles to the poultry producers/farmers.

  11. PNNL Fungal Biotechnology Core DOE-OBP Project

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Scott E.; Bruno, Kenneth S.; Butcher, Mark G.; Collett, James R.; Culley, David E.; Dai, Ziyu; Magnuson, Jon K.; Panisko, Ellen A.

    2009-11-30

    In 2009, we continued to address barriers to fungal fermentation in the primary areas of morphology control, genomics, proteomics, fungal hyperproductivity, biomass-to-products via fungal based consolidated bioprocesses, and filamentous fungal ethanol. “Alternative renewable fuels from fungi” was added as a new subtask. Plans were also made to launch a new advanced strain development subtask in FY2010.

  12. Natural disturbance reduces disease risk in endangered rainforest frog populations.

    Science.gov (United States)

    Roznik, Elizabeth A; Sapsford, Sarah J; Pike, David A; Schwarzkopf, Lin; Alford, Ross A

    2015-08-21

    Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations. Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs (Litoria rheocola) becoming infected by a fungal pathogen (Batrachochytrium dendrobatidis). Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. dendrobatidis infection risk in frogs by an average of 11-28% in cyclone-damaged areas, relative to unaffected areas. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence.

  13. HIV/AIDS and Fungal Infections

    Science.gov (United States)

    ... Environmental Diseases Mycotic Diseases Branch People living with HIV/AIDS Recommend on Facebook Tweet Share Compartir As ... Page Preventing fungal infections in people living with HIV/AIDS Fungi are difficult to avoid because they ...

  14. Postharvest fungal deterioration of tomato ( Lycopersicum ...

    African Journals Online (AJOL)

    Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives ... tomatoes and pepper were sourced from Mile 12 Market in Lagos state. ... the ingestion of mycotoxins that are usually associated with fungal species), ...

  15. Fungal rhino sinusitisin in tehran, iran

    NARCIS (Netherlands)

    Nazeri, M.; Hashemi, S.J.; Ardehali, M.; Rezaei, S.; Seyedmousavi, S.; Zareei, M.; Hosseinjani, E.

    2015-01-01

    BACKGROUND: Fungal rhino sinusitis (FRS) is an important infection of para nasal sinuses, which encompasses two main categories; invasive and noninvasive forms according to histopathological findings. Aspergillus spp are the most common species isolated from noninvasive form, while Mucorales are

  16. Zoosporic fungal parasites of marine biota

    Digital Repository Service at National Institute of Oceanography (India)

    RaghuKumar, C.

    laboratory media. In such instances, a detailed and careful examination of the disease symptoms and the endobiotic fungal parasites is to be recorded. Maintaining dual culture of the healthy and infected host also helps to fulfill these postulates partially....

  17. Organ Transplant Patients and Fungal Infections

    Science.gov (United States)

    ... are mild skin rashes, but others can be deadly, like fungal pneumonia. Because of this, it’s important ... the environment. Fungi live outdoors in soil, on plants, trees, and other vegetation. They are also on ...

  18. Air Contamination With Fungals In Museum

    Science.gov (United States)

    Scarlat, Iuliana; Haiducu, Maria; Stepa, Raluca

    2015-07-01

    The aim of the studies was to determine the level and kind of fungal contamination of air in museum, deposits patrimony, restoration and conservation laboratories and their effects on health of workers. Microbiological air purity was measured with a SAS-100 Surface Air System impactor. The fungal contamination was observed in all 54 rooms where we made determinations. The highest levels of fungal were recorded at rooms with hygroscopic patrimony objects, eg carpets, chairs, upholstered chairs, books etc. The most species identified included under common allergens: Aspergillus, Penicillium, and Mucor. There fungal species belonging to the genus identified in this study, can trigger serious diseases museum workers, such as for example Aspergillus fumigatus, known allergies and toxic effects that may occur. In some places of the museum, occupational exposure limit values to fungi present in the air in the work environment, recommended by the specialized literature, have been overcome.

  19. Fungal keratitis - improving diagnostics by confocal microscopy

    DEFF Research Database (Denmark)

    Nielsen, Esben; Heegaard, S; Prause, J U

    2013-01-01

    Purpose: Introducing a simple image grading system to support the interpretation of in vivo confocal microscopy (IVCM) images in filamentous fungal keratitis. Setting: Clinical and confocal studies took place at the Department of Ophthalmology, Aarhus University Hospital, Denmark. Histopathological...... analysis was performed at the Eye Pathology Institute, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark. Methods: A recent series of consecutive patients with filamentous fungal keratitis is presented to demonstrate the results from in-house IVCM. Based upon our experience...... with IVCM and previously published images, we composed a grading system for interpreting IVCM images of filamentous fungal keratitis. Results: A recent case series of filamentous fungal keratitis from 2011 to 2012 was examined. There were 3 male and 3 female patients. Mean age was 44.5 years (range 12...

  20. Susceptible-infected-susceptible epidemics on networks with general infection and cure times

    Science.gov (United States)

    Cator, E.; van de Bovenkamp, R.; Van Mieghem, P.

    2013-06-01

    The classical, continuous-time susceptible-infected-susceptible (SIS) Markov epidemic model on an arbitrary network is extended to incorporate infection and curing or recovery times each characterized by a general distribution (rather than an exponential distribution as in Markov processes). This extension, called the generalized SIS (GSIS) model, is believed to have a much larger applicability to real-world epidemics (such as information spread in online social networks, real diseases, malware spread in computer networks, etc.) that likely do not feature exponential times. While the exact governing equations for the GSIS model are difficult to deduce due to their non-Markovian nature, accurate mean-field equations are derived that resemble our previous N-intertwined mean-field approximation (NIMFA) and so allow us to transfer the whole analytic machinery of the NIMFA to the GSIS model. In particular, we establish the criterion to compute the epidemic threshold in the GSIS model. Moreover, we show that the average number of infection attempts during a recovery time is the more natural key parameter, instead of the effective infection rate in the classical, continuous-time SIS Markov model. The relative simplicity of our mean-field results enables us to treat more general types of SIS epidemics, while offering an easier key parameter to measure the average activity of those general viral agents.

  1. Epidemic dynamics and endemic states in complex networks

    Science.gov (United States)

    Pastor-Satorras, Romualdo; Vespignani, Alessandro

    2001-06-01

    We study by analytical methods and large scale simulations a dynamical model for the spreading of epidemics in complex networks. In networks with exponentially bounded connectivity we recover the usual epidemic behavior with a threshold defining a critical point below that the infection prevalence is null. On the contrary, on a wide range of scale-free networks we observe the absence of an epidemic threshold and its associated critical behavior. This implies that scale-free networks are prone to the spreading and the persistence of infections whatever spreading rate the epidemic agents might possess. These results can help understanding computer virus epidemics and other spreading phenomena on communication and social networks.

  2. Epidemic dynamics and endemic states in complex networks

    International Nuclear Information System (INIS)

    Pastor-Satorras, Romualdo; Vespignani, Alessandro

    2001-01-01

    We study by analytical methods and large scale simulations a dynamical model for the spreading of epidemics in complex networks. In networks with exponentially bounded connectivity we recover the usual epidemic behavior with a threshold defining a critical point below that the infection prevalence is null. On the contrary, on a wide range of scale-free networks we observe the absence of an epidemic threshold and its associated critical behavior. This implies that scale-free networks are prone to the spreading and the persistence of infections whatever spreading rate the epidemic agents might possess. These results can help understanding computer virus epidemics and other spreading phenomena on communication and social networks

  3. Toward a generalized theory of epidemic awareness in social networks

    Science.gov (United States)

    Wu, Qingchu; Zhu, Wenfang

    We discuss the dynamics of a susceptible-infected-susceptible (SIS) model with local awareness in networks. Individual awareness to the infectious disease is characterized by a general function of epidemic information in its neighborhood. We build a high-accuracy approximate equation governing the spreading dynamics and derive an approximate epidemic threshold above which the epidemic spreads over the whole network. Our results extend the previous work and show that the epidemic threshold is dependent on the awareness function in terms of one infectious neighbor. Interestingly, when a pow-law awareness function is chosen, the epidemic threshold can emerge in infinite networks.

  4. Human Fungal Pathogens of Mucorales and Entomophthorales.

    Science.gov (United States)

    Mendoza, Leonel; Vilela, Raquel; Voelz, Kerstin; Ibrahim, Ashraf S; Voigt, Kerstin; Lee, Soo Chan

    2014-11-06

    In recent years, we have seen an increase in the number of immunocompromised cohorts as a result of infections and/or medical conditions, which has resulted in an increased incidence of fungal infections. Although rare, the incidence of infections caused by fungi belonging to basal fungal lineages is also continuously increasing. Basal fungal lineages diverged at an early point during the evolution of the fungal lineage, in which, in a simplified four-phylum fungal kingdom, Zygomycota and Chytridiomycota belong to the basal fungi, distinguishing them from Ascomycota and Basidiomycota. Currently there are no known human infections caused by fungi in Chytridiomycota; only Zygomycotan fungi are known to infect humans. Hence, infections caused by zygomycetes have been called zygomycosis, and the term "zygomycosis" is often used as a synonym for "mucormycosis." In the four-phylum fungal kingdom system, Zygomycota is classified mainly based on morphology, including the ability to form coenocytic (aseptated) hyphae and zygospores (sexual spores). In the Zygomycota, there are 10 known orders, two of which, the Mucorales and Entomophthorales, contain species that can infect humans, and the infection has historically been known as zygomycosis. However, recent multilocus sequence typing analyses (the fungal tree of life [AFTOL] project) revealed that the Zygomycota forms not a monophyletic clade but instead a polyphyletic clade, whereas Ascomycota and Basidiomycota are monophyletic. Thus, the term "zygomycosis" needed to be further specified, resulting in the terms "mucormycosis" and "entomophthoramycosis." This review covers these two different types of fungal infections. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  5. Burden of fungal infections in Senegal.

    Science.gov (United States)

    Badiane, Aida S; Ndiaye, Daouda; Denning, David W

    2015-10-01

    Senegal has a high rate of tuberculosis and a low HIV seropositivity rate and aspergilloma, life-threatening fungal infections, dermatophytosis and mycetoma have been reported in this study. All published epidemiology papers reporting fungal infection rates from Senegal were identified. Where no data existed, we used specific populations at risk and fungal infection frequencies in each to estimate national incidence or prevalence. The results show that tinea capitis is common being found in 25% of children, ~1.5 million. About 191,000 Senegalese women get recurrent vaginal thrush, ≥4 times annually. We estimate 685 incident cases of chronic pulmonary aspergillosis (CPA) following TB and prevalence of 2160 cases. Asthma prevalence in adults varies from 3.2% to 8.2% (mean 5%); 9976 adults have allergic bronchopulmonary aspergillosis (ABPA) and 13,168 have severe asthma with fungal sensitisation (SAFS). Of the 59,000 estimated HIV-positive patients, 366 develop cryptococcal meningitis; 1149 develop Pneumocystis pneumonia and 1946 develop oesophageal candidiasis, in which oral candidiasis (53%) and dermatophytosis (16%) are common. Since 2008-2010, 113 cases of mycetoma were diagnosed. In conclusion, we estimate that 1,743,507 (12.5%) people in Senegal suffer from a fungal infection, excluding oral candidiasis, fungal keratitis, invasive candidiasis or aspergillosis. Diagnostic and treatment deficiencies should be rectified to allow epidemiological studies. © 2015 Blackwell Verlag GmbH.

  6. Epidemic Spreading with Heterogeneous Awareness on Human Networks

    Directory of Open Access Journals (Sweden)

    Yanling Lu

    2017-01-01

    Full Text Available The spontaneous awareness behavioral responses of individuals have a significant impact on epidemic spreading. In this paper, a modified Susceptible-Alert-Infected-Susceptible (SAIS epidemic model with heterogeneous awareness is presented to study epidemic spreading in human networks and the impact of heterogeneous awareness on epidemic dynamics. In this model, when susceptible individuals receive awareness information about the presence of epidemic from their infected neighbor nodes, they will become alert individuals with heterogeneous awareness rate. Theoretical analysis and numerical simulations show that heterogeneous awareness can enhance the epidemic threshold with certain conditions and reduce the scale of virus outbreaks compared with no awareness. What is more, for the same awareness parameter, it also shows that heterogeneous awareness can slow effectively the spreading size and does not delay the arrival time of epidemic spreading peak compared with homogeneous awareness.

  7. Unrelated facultative endosymbionts protect aphids against a fungal pathogen.

    Science.gov (United States)

    Łukasik, Piotr; van Asch, Margriet; Guo, Huifang; Ferrari, Julia; Godfray, H Charles J

    2013-02-01

    The importance of microbial facultative endosymbionts to insects is increasingly being recognized, but our understanding of how the fitness effects of infection are distributed across symbiont taxa is limited. In the pea aphid, some of the seven known species of facultative symbionts influence their host's resistance to natural enemies, including parasitoid wasps and a pathogenic fungus. Here we show that protection against this entomopathogen, Pandora neoaphidis, can be conferred by strains of four distantly related symbionts (in the genera Regiella, Rickettsia, Rickettsiella and Spiroplasma). They reduce mortality and also decrease fungal sporulation on dead aphids which may help protect nearby genetically identical insects. Pea aphids thus obtain protection from natural enemies through association with a wider range of microbial associates than has previously been thought. Providing resistance against natural enemies appears to be a particularly common way for facultative endosymbionts to increase in frequency within host populations. © 2012 Blackwell Publishing Ltd/CNRS.

  8. Extinction times of epidemic outbreaks in networks.

    Science.gov (United States)

    Holme, Petter

    2013-01-01

    In the Susceptible-Infectious-Recovered (SIR) model of disease spreading, the time to extinction of the epidemics happens at an intermediate value of the per-contact transmission probability. Too contagious infections burn out fast in the population. Infections that are not contagious enough die out before they spread to a large fraction of people. We characterize how the maximal extinction time in SIR simulations on networks depend on the network structure. For example we find that the average distances in isolated components, weighted by the component size, is a good predictor of the maximal time to extinction. Furthermore, the transmission probability giving the longest outbreaks is larger than, but otherwise seemingly independent of, the epidemic threshold.

  9. Epidemic extinction paths in complex networks

    Science.gov (United States)

    Hindes, Jason; Schwartz, Ira B.

    2017-05-01

    We study the extinction of long-lived epidemics on finite complex networks induced by intrinsic noise. Applying analytical techniques to the stochastic susceptible-infected-susceptible model, we predict the distribution of large fluctuations, the most probable or optimal path through a network that leads to a disease-free state from an endemic state, and the average extinction time in general configurations. Our predictions agree with Monte Carlo simulations on several networks, including synthetic weighted and degree-distributed networks with degree correlations, and an empirical high school contact network. In addition, our approach quantifies characteristic scaling patterns for the optimal path and distribution of large fluctuations, both near and away from the epidemic threshold, in networks with heterogeneous eigenvector centrality and degree distributions.

  10. Spread of epidemic disease on networks

    Science.gov (United States)

    Newman, M. E.

    2002-07-01

    The study of social networks, and in particular the spread of disease on networks, has attracted considerable recent attention in the physics community. In this paper, we show that a large class of standard epidemiological models, the so-called susceptible/infective/removed (SIR) models can be solved exactly on a wide variety of networks. In addition to the standard but unrealistic case of fixed infectiveness time and fixed and uncorrelated probability of transmission between all pairs of individuals, we solve cases in which times and probabilities are nonuniform and correlated. We also consider one simple case of an epidemic in a structured population, that of a sexually transmitted disease in a population divided into men and women. We confirm the correctness of our exact solutions with numerical simulations of SIR epidemics on networks.

  11. Ciguatera fish poisoning. A southern California epidemic.

    Science.gov (United States)

    Barton, E D; Tanner, P; Turchen, S G; Tunget, C L; Manoguerra, A; Clark, R F

    1995-01-01

    Ciguatera fish poisoning results from the bioconcentration of a variety of toxins produced by marine dinoflagellates. Signs and symptoms vary widely, but it usually presents as gastrointestinal and neurologic complaints beginning shortly after the ingestion of fish containing the toxins. Symptoms may persist for months and sometimes even years. Although cases have been reported throughout the United States, epidemics are most common along tropical and subtropical coasts and usually involve the ingestion of large carnivorous fish. We review the literature and report the first epidemic of 25 cases of ciguatera fish poisoning presenting to area hospitals in Southern California that were successfully tracked by the Department of Health Services and isolated to fish caught off the coast of Baja California, Mexico. Images Figure 1. PMID:7667980

  12. A break in the obesity epidemic?

    DEFF Research Database (Denmark)

    Visscher, T L S; Heitmann, B L; Rissanen, A

    2015-01-01

    Recent epidemiologic papers are presenting prevalence data suggesting breaks and decreases in obesity rates. However, before concluding that the obesity epidemic is not increasing anymore, the validity of the presented data should be discussed more thoroughly. We had a closer look into the litera......, focusing on trends in waist circumference rather than BMI leads to a less optimistic conclusion: the public health problem of obesity is still increasing.International Journal of Obesity advance online publication, 22 July 2014; doi:10.1038/ijo.2014.98....... into the literature presented in recent reviews to address the major potential biases and distortions, and to develop insights about how to interpret the presented suggestions for a potential break in the obesity epidemic. Decreasing participation rates, the use of reported rather than measured data and small sample...

  13. Eight challenges for network epidemic models

    Directory of Open Access Journals (Sweden)

    Lorenzo Pellis

    2015-03-01

    Full Text Available Networks offer a fertile framework for studying the spread of infection in human and animal populations. However, owing to the inherent high-dimensionality of networks themselves, modelling transmission through networks is mathematically and computationally challenging. Even the simplest network epidemic models present unanswered questions. Attempts to improve the practical usefulness of network models by including realistic features of contact networks and of host–pathogen biology (e.g. waning immunity have made some progress, but robust analytical results remain scarce. A more general theory is needed to understand the impact of network structure on the dynamics and control of infection. Here we identify a set of challenges that provide scope for active research in the field of network epidemic models.

  14. Computational algebraic geometry of epidemic models

    Science.gov (United States)

    Rodríguez Vega, Martín.

    2014-06-01

    Computational Algebraic Geometry is applied to the analysis of various epidemic models for Schistosomiasis and Dengue, both, for the case without control measures and for the case where control measures are applied. The models were analyzed using the mathematical software Maple. Explicitly the analysis is performed using Groebner basis, Hilbert dimension and Hilbert polynomials. These computational tools are included automatically in Maple. Each of these models is represented by a system of ordinary differential equations, and for each model the basic reproductive number (R0) is calculated. The effects of the control measures are observed by the changes in the algebraic structure of R0, the changes in Groebner basis, the changes in Hilbert dimension, and the changes in Hilbert polynomials. It is hoped that the results obtained in this paper become of importance for designing control measures against the epidemic diseases described. For future researches it is proposed the use of algebraic epidemiology to analyze models for airborne and waterborne diseases.

  15. Extinction times of epidemic outbreaks in networks.

    Directory of Open Access Journals (Sweden)

    Petter Holme

    Full Text Available In the Susceptible-Infectious-Recovered (SIR model of disease spreading, the time to extinction of the epidemics happens at an intermediate value of the per-contact transmission probability. Too contagious infections burn out fast in the population. Infections that are not contagious enough die out before they spread to a large fraction of people. We characterize how the maximal extinction time in SIR simulations on networks depend on the network structure. For example we find that the average distances in isolated components, weighted by the component size, is a good predictor of the maximal time to extinction. Furthermore, the transmission probability giving the longest outbreaks is larger than, but otherwise seemingly independent of, the epidemic threshold.

  16. Emergence of epidemics in rapidly varying networks

    International Nuclear Information System (INIS)

    Kohar, Vivek; Sinha, Sudeshna

    2013-01-01

    We describe a simple model mimicking disease spreading on a network with dynamically varying connections, and investigate the dynamical consequences of switching links in the network. Our central observation is that the disease cycles get more synchronized, indicating the onset of epidemics, as the underlying network changes more rapidly. This behavior is found for periodically switched links, as well as links that switch randomly in time. We find that the influence of changing links is more pronounced in networks where the nodes have lower degree, and the disease cycle has a longer infective stage. Further, when the switching of links is periodic we observe finer dynamical features, such as beating patterns in the emergent oscillations and resonant enhancement of synchronization, arising from the interplay between the time-scales of the connectivity changes and that of the epidemic outbreaks

  17. [The depression epidemic does not exist].

    Science.gov (United States)

    van der Feltz-Cornelis, Christina M

    2009-01-01

    There has been much discussion in the media about the question of the existence of a depression epidemic. This leads on to the questions of whether the social and economic approaches are adequate, and what the alternatives are. The concept of the disease 'depression' can be defined using a medical model, or from a patient's or a societal perspective. From a medical perspective, indeed a depression epidemic has ensued from the increased prosperity and the associated decompression of the mortality rate. Society responded with preventative measures and policies aimed at improving functioning in the workplace. However, patients with a major depressive disorder (MDD) who are eligible for treatment are often not motivated to take it up, or are undertreated. Research is necessary in order to explore what patients think about the identification and treatment of depression. The confusion regarding the concept of depression found in the media, needs to be cleared.

  18. Opioid Epidemic: Cellular & Molecular Anesthesia as a Key Solution

    Directory of Open Access Journals (Sweden)

    Ali Dabbagh

    2017-12-01

    Full Text Available Opioids are one of the most important arsenals armamentarium of physicians for fighting against pain. During the decades, opioids have been used in a wide range of indications; both for treatment of acute and chronic pain; as natural and synthetic compounds and in a variety of delivery forms from intravenous infusion to intrathecal adjuvants of local anesthetics or as transdermal patches. There is no doubt that we are in an opioid misuse epidemic status; whether in the US or other countries; but if we want to resolve this miserable multilateral complication, there is no doubt that Cellular and Molecular aspects of Anesthesia has a key role in resolving the problem; through creating an opioid free pain management era.

  19. Global dynamics of a dengue epidemic mathematical model

    Energy Technology Data Exchange (ETDEWEB)

    Cai Liming [Department of Mathematics, Xinyang Normal University, Xinyang 464000 (China); Academy of Mathematics and Systems Science, Academia Sinica, Beijing 100080 (China)], E-mail: lmcai06@yahoo.com.cn; Guo Shumin [Beijing Institute of Information Control, Beijing 100037 (China); Li, XueZhi [Department of Mathematics, Xinyang Normal University, Xinyang 464000 (China); Ghosh, Mini [School of Mathematics and Computer Application, Thapar University, Patiala 147004 (India)

    2009-11-30

    The paper investigates the global stability of a dengue epidemic model with saturation and bilinear incidence. The constant human recruitment rate and exponential natural death, as well as vector population with asymptotically constant population, are incorporated into the model. The model exhibits two equilibria, namely, the disease-free equilibrium and the endemic equilibrium. The stability of these two equilibria is controlled by the threshold number R{sub 0}. It is shown that if R{sub 0} is less than one, the disease-free equilibrium is globally asymptotically stable and in such a case the endemic equilibrium does not exist; if R{sub 0} is greater than one, then the disease persists and the unique endemic equilibrium is globally asymptotically stable.

  20. Global dynamics of a dengue epidemic mathematical model

    International Nuclear Information System (INIS)

    Cai Liming; Guo Shumin; Li, XueZhi; Ghosh, Mini

    2009-01-01

    The paper investigates the global stability of a dengue epidemic model with saturation and bilinear incidence. The constant human recruitment rate and exponential natural death, as well as vector population with asymptotically constant population, are incorporated into the model. The model exhibits two equilibria, namely, the disease-free equilibrium and the endemic equilibrium. The stability of these two equilibria is controlled by the threshold number R 0 . It is shown that if R 0 is less than one, the disease-free equilibrium is globally asymptotically stable and in such a case the endemic equilibrium does not exist; if R 0 is greater than one, then the disease persists and the unique endemic equilibrium is globally asymptotically stable.

  1. New Approaches to the Methamphetamine Epidemic

    OpenAIRE

    Zusman, Mara B.

    2004-01-01

    Methamphetamine abuse has become an epidemic in the United States. As methamphetamine becomes increasingly available, more and more people are trying – and becoming addicted to – this potent drug. But although methamphetamine is made using over-the-counter (OTC) drugs containing pseudoephedrine, shifting OTC drugs containing pseudoephedrine to prescription status is not the solution to the methamphetamine crisis. Rather, society must adopt a comprehensive...

  2. The 1982 epidemic--roller skating injuries.

    Science.gov (United States)

    Bunker, T. D.

    1983-01-01

    A series of 100 roller skating injuries is presented. Roller skating injuries have been occurring at a higher rate than the previously reported skateboarding epidemic of 1977. The severity of injury has been lower, 32% fractures and dislocations occurring whilst roller skating, compared to 60% whilst skateboarding. In particular a striking reduction is seen in ankle fractures. Fifty questionnaires detailing method of injury were analysed. Images p205-a Fig. 1 Fig. 2 PMID:6652406

  3. Impact of the infectious period on epidemics

    Science.gov (United States)

    Wilkinson, Robert R.; Sharkey, Kieran J.

    2018-05-01

    The duration of the infectious period is a crucial determinant of the ability of an infectious disease to spread. We consider an epidemic model that is network based and non-Markovian, containing classic Kermack-McKendrick, pairwise, message passing, and spatial models as special cases. For this model, we prove a monotonic relationship between the variability of the infectious period (with fixed mean) and the probability that the infection will reach any given subset of the population by any given time. For certain families of distributions, this result implies that epidemic severity is decreasing with respect to the variance of the infectious period. The striking importance of this relationship is demonstrated numerically. We then prove, with a fixed basic reproductive ratio (R0), a monotonic relationship between the variability of the posterior transmission probability (which is a function of the infectious period) and the probability that the infection will reach any given subset of the population by any given time. Thus again, even when R0 is fixed, variability of the infectious period tends to dampen the epidemic. Numerical results illustrate this but indicate the relationship is weaker. We then show how our results apply to message passing, pairwise, and Kermack-McKendrick epidemic models, even when they are not exactly consistent with the stochastic dynamics. For Poissonian contact processes, and arbitrarily distributed infectious periods, we demonstrate how systems of delay differential equations and ordinary differential equations can provide upper and lower bounds, respectively, for the probability that any given individual has been infected by any given time.

  4. Dynamics of epidemics outbreaks in heterogeneous populations

    Science.gov (United States)

    Brockmann, Dirk; Morales-Gallardo, Alejandro; Geisel, Theo

    2007-03-01

    The dynamics of epidemic outbreaks have been investigated in recent years within two alternative theoretical paradigms. The key parameter of mean field type of models such as the SIR model is the basic reproduction number R0, the average number of secondary infections caused by one infected individual. Recently, scale free network models have received much attention as they account for the high variability in the number of social contacts involved. These models predict an infinite basic reproduction number in some cases. We investigate the impact of heterogeneities of contact rates in a generic model for epidemic outbreaks. We present a system in which both the time periods of being infectious and the time periods between transmissions are Poissonian processes. The heterogeneities are introduced by means of strongly variable contact rates. In contrast to scale free network models we observe a finite basic reproduction number and, counterintuitively a smaller overall epidemic outbreak as compared to the homogeneous system. Our study thus reveals that heterogeneities in contact rates do not necessarily facilitate the spread to infectious disease but may well attenuate it.

  5. Connecting the obesity and the narcissism epidemics.

    Science.gov (United States)

    Lemaitre, Bruno

    2016-10-01

    Obesity and metabolic syndromes are major threats to health in both developed and developing countries. This opinion article is a holistic attempt to understand the obesity epidemic, by connecting it to the widespread narcissism in society. The narcissism epidemic refers to an increased prevalence of status-striving individualism and a decreased sense of community, observed in Westerns populations and spreading worldwide. Based on social personality and evolutionary psychology approaches, I speculate that this rise of narcissism underlies a steep social hierarchy resulting in increase of social stress. This social stress markedly affects individuals who are sensitive to social hierarchy dominance due to their personality, yet are relegated at a lower social position. I speculate that over-eating is one major mechanism for coping with this stress, and discuss the possibility that visceral fat may constitute an adaptive behaviour to the lower social hierarchy position, which is perceived as unjust. Connecting the prevalence of obesity to the narcissism epidemic allows for a more thorough examination of factors, which contribute to obesity, which includes early difficult childhood experience, lower rank, and the overall competitive framework of the society. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  6. Discrete stochastic analogs of Erlang epidemic models.

    Science.gov (United States)

    Getz, Wayne M; Dougherty, Eric R

    2018-12-01

    Erlang differential equation models of epidemic processes provide more realistic disease-class transition dynamics from susceptible (S) to exposed (E) to infectious (I) and removed (R) categories than the ubiquitous SEIR model. The latter is itself is at one end of the spectrum of Erlang SE[Formula: see text]I[Formula: see text]R models with [Formula: see text] concatenated E compartments and [Formula: see text] concatenated I compartments. Discrete-time models, however, are computationally much simpler to simulate and fit to epidemic outbreak data than continuous-time differential equations, and are also much more readily extended to include demographic and other types of stochasticity. Here we formulate discrete-time deterministic analogs of the Erlang models, and their stochastic extension, based on a time-to-go distributional principle. Depending on which distributions are used (e.g. discretized Erlang, Gamma, Beta, or Uniform distributions), we demonstrate that our formulation represents both a discretization of Erlang epidemic models and generalizations thereof. We consider the challenges of fitting SE[Formula: see text]I[Formula: see text]R models and our discrete-time analog to data (the recent outbreak of Ebola in Liberia). We demonstrate that the latter performs much better than the former; although confining fits to strict SEIR formulations reduces the numerical challenges, but sacrifices best-fit likelihood scores by at least 7%.

  7. Epidemic risk from cholera introductions into Mexico.

    Science.gov (United States)

    Moore, Sean M; Shannon, Kerry L; Zelaya, Carla E; Azman, Andrew S; Lessler, Justin

    2014-02-21

    Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resulting in outbreaks of 2 to over 150 people. Using publicly available data, we attempt to estimate the reproductive number (R) of cholera in Mexico, and thereby assess the potential of continued introductions to establish a sustained epidemic. We estimate R for cholera in Mexico to be between 0.8 to 1.1, depending on the number of introductions, with the confidence intervals for the most plausible estimates crossing 1. These results suggest that the efficiency of cholera transmission in some regions of Mexico is near that necessary for a large epidemic. Intensive surveillance, evaluation of water and sanitation infrastructure, and planning for rapid response are warranted steps to avoid potential large epidemics in the region.

  8. Inferring epidemic network topology from surveillance data.

    Directory of Open Access Journals (Sweden)

    Xiang Wan

    Full Text Available The transmission of infectious diseases can be affected by many or even hidden factors, making it difficult to accurately predict when and where outbreaks may emerge. One approach at the moment is to develop and deploy surveillance systems in an effort to detect outbreaks as timely as possible. This enables policy makers to modify and implement strategies for the control of the transmission. The accumulated surveillance data including temporal, spatial, clinical, and demographic information, can provide valuable information with which to infer the underlying epidemic networks. Such networks can be quite informative and insightful as they characterize how infectious diseases transmit from one location to another. The aim of this work is to develop a computational model that allows inferences to be made regarding epidemic network topology in heterogeneous populations. We apply our model on the surveillance data from the 2009 H1N1 pandemic in Hong Kong. The inferred epidemic network displays significant effect on the propagation of infectious diseases.

  9. Cyanobacteria facilitate parasite epidemics in Daphnia.

    Science.gov (United States)

    Tellenbach, C; Tardent, N; Pomati, F; Keller, B; Hairston, N G; Wolinska, J; Spaak, P

    2016-12-01

    The seasonal dominance of cyanobacteria in the phytoplankton community of lake ecosystems can have severe implications for higher trophic levels. For herbivorous zooplankton such as Daphnia, cyanobacteria have poor nutritional value and some species can produce toxins affecting zooplankton survival and reproduction. Here we present another, hitherto largely unexplored aspect of cyanobacteria, namely that they can increase Daphnia susceptibility to parasites. In a 12-yr monthly time-series analysis of the Daphnia community in Greifensee (Switzerland), we observed that cyanobacteria density correlated significantly with the epidemics of a common gut parasite of Daphnia, Caullerya mesnili, regardless of what cyanobacteria species was present or whether it was colonial or filamentous. The temperature from the previous month also affected the occurrence of Caullerya epidemics, either directly or indirectly by the promotion of cyanobacterial growth. A laboratory experiment confirmed that cyanobacteria increase the susceptibility of Daphnia to Caullerya, and suggested a possible involvement of cyanotoxins or other chemical traits of cyanobacteria in this process. These findings expand our understanding of the consequences of toxic cyanobacterial blooms for lake ecosystems and might be relevant for epidemics experienced by other aquatic species. © 2016 by the Ecological Society of America.

  10. [Fight against epidemics: Austrian prisoners in Troyes].

    Science.gov (United States)

    Hetzel, Géraldine

    2014-01-01

    The victories near Ulm and Elchingen, where the Napoleonic army took 60000 prisoners between 15th and 20th of October 1805, lead to the arrival at Troyes (county "Aube") of nearly 2000 Austrian soldiers to be held inside former monasteries among whose, mainly the Jacobinians casern where more than half of them stayed. At the beginning of 1806, the government sent the epidemics medical practitioner Dr Desgenettes on an inspection tour to control the state of health of the populations of places where foreign prisoners were held, which lead him through several counties of the North-eastern part of France, where he surveyed several diseases ranging from all kinds offevers up to dysentery, scabies or gangrenes. With the means of acid fumigations invented by the chemist Guyton Morveau from Dijon, the authorities took care of combating and preventing the epidemics in the caserns. As soon as October 1805, the epidemics medical practitioner Dr Pigeotte from Troyes wrote to the county governor his observations recommending a better diet, airing of the rooms and also calls to take some exercise. All these precepts showed an astonishing modernity.

  11. Invited review: Epidemics on social networks

    Directory of Open Access Journals (Sweden)

    M. N. Kuperman

    2013-01-01

    Full Text Available Since its first formulations almost a century ago, mathematical models fordisease spreading contributed to understand, evaluate and control the epidemic processes.They promoted a dramatic change in how epidemiologists thought of the propagation of infectious diseases.In the last decade, when the traditional epidemiological models seemed to be exhausted, new types of models were developed.These new models incorporated concepts from graph theory to describe and model the underlying social structure.Many of these works merely produced a more detailed extension of the previous results, but some otherstriggered a completely new paradigm in the mathematical study of epidemic processes. In this review, we will introduce the basicconcepts of epidemiology, epidemic modeling and networks, to finally provide a brief description of the mostrelevant results in the field.Received: 6 April 2013, Accepted: 3 June 2013; Edited by: G. Mindlin; DOI: http://dx.doi.org/10.4279/PIP.050003Cite as: M N Kuperman, Papers in Physics 5, 050003 (2013

  12. Epidemics in partially overlapped multiplex networks.

    Directory of Open Access Journals (Sweden)

    Camila Buono

    Full Text Available Many real networks exhibit a layered structure in which links in each layer reflect the function of nodes on different environments. These multiple types of links are usually represented by a multiplex network in which each layer has a different topology. In real-world networks, however, not all nodes are present on every layer. To generate a more realistic scenario, we use a generalized multiplex network and assume that only a fraction [Formula: see text] of the nodes are shared by the layers. We develop a theoretical framework for a branching process to describe the spread of an epidemic on these partially overlapped multiplex networks. This allows us to obtain the fraction of infected individuals as a function of the effective probability that the disease will be transmitted [Formula: see text]. We also theoretically determine the dependence of the epidemic threshold on the fraction [Formula: see text] of shared nodes in a system composed of two layers. We find that in the limit of [Formula: see text] the threshold is dominated by the layer with the smaller isolated threshold. Although a system of two completely isolated networks is nearly indistinguishable from a system of two networks that share just a few nodes, we find that the presence of these few shared nodes causes the epidemic threshold of the isolated network with the lower propagating capacity to change discontinuously and to acquire the threshold of the other network.

  13. Mechanistic movement models to understand epidemic spread.

    Science.gov (United States)

    Fofana, Abdou Moutalab; Hurford, Amy

    2017-05-05

    An overlooked aspect of disease ecology is considering how and why animals come into contact with one and other resulting in disease transmission. Mathematical models of disease spread frequently assume mass-action transmission, justified by stating that susceptible and infectious hosts mix readily, and foregoing any detailed description of host movement. Numerous recent studies have recorded, analysed and modelled animal movement. These movement models describe how animals move with respect to resources, conspecifics and previous movement directions and have been used to understand the conditions for the occurrence and the spread of infectious diseases when hosts perform a type of movement. Here, we summarize the effect of the different types of movement on the threshold conditions for disease spread. We identify gaps in the literature and suggest several promising directions for future research. The mechanistic inclusion of movement in epidemic models may be beneficial for the following two reasons. Firstly, the estimation of the transmission coefficient in an epidemic model is possible because animal movement data can be used to estimate the rate of contacts between conspecifics. Secondly, unsuccessful transmission events, where a susceptible host contacts an infectious host but does not become infected can be quantified. Following an outbreak, this enables disease ecologists to identify 'near misses' and to explore possible alternative epidemic outcomes given shifts in ecological or immunological parameters.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

  14. Fungal-host diversity among mycoheterotrophic plants increases proportionally to their fungal-host overlap.

    Science.gov (United States)

    Gomes, Sofia I F; Merckx, Vincent S F T; Saavedra, Serguei

    2017-05-01

    The vast majority of plants obtain an important proportion of vital resources from soil through mycorrhizal fungi. Generally, this happens in exchange of photosynthetically fixed carbon, but occasionally the interaction is mycoheterotrophic, and plants obtain carbon from mycorrhizal fungi. This process results in an antagonistic interaction between mycoheterotrophic plants and their fungal hosts. Importantly, the fungal-host diversity available for plants is restricted as mycoheterotrophic interactions often involve narrow lineages of fungal hosts. Unfortunately, little is known whether fungal-host diversity may be additionally modulated by plant-plant interactions through shared hosts. Yet, this may have important implications for plant competition and coexistence. Here, we use DNA sequencing data to investigate the interaction patterns between mycoheterotrophic plants and arbuscular mycorrhizal fungi. We find no phylogenetic signal on the number of fungal hosts nor on the fungal hosts shared among mycoheterotrophic plants. However, we observe a potential trend toward increased phylogenetic diversity of fungal hosts among mycoheterotrophic plants with increasing overlap in their fungal hosts. While these patterns remain for groups of plants regardless of location, we do find higher levels of overlap and diversity among plants from the same location. These findings suggest that species coexistence cannot be fully understood without attention to the two sides of ecological interactions.

  15. Protection by fungal starters against growth and secondary metabolite production of fungal spoilers of cheese.

    Science.gov (United States)

    Nielsen, M S; Frisvad, J C; Nielsen, P V

    1998-06-30

    The influence of fungal starter cultures on growth and secondary metabolite production of fungal contaminants associated with cheese was studied on laboratory media and Camembert cheese. Isolates of the species Penicillium nalgiovense, P. camemberti, P. roqueforti and Geotrichum candidum were used as fungal starters. The species P. commune, P. caseifulvum, P. verrucosum, P. discolor, P. solitum, P. coprophilum and Aspergillus versicolor were selected as contaminants. The fungal starters showed different competitive ability on laboratory media and Camembert cheese. The presence of the Penicillium species, especially P. nalgiovense, showed an inhibitory effect on the growth of the fungal contaminants on laboratory media. G. candidum caused a significant inhibition of the fungal contaminants on Camembert cheese. The results indicate that G. candidum plays an important role in competition with undesirable microorganisms in mould fermented cheeses. Among the starters, P. nalgiovense caused the largest reduction in secondary metabolite production of the fungal contaminants on the laboratory medium. On Camembert cheese no significant changes in metabolite production of the fungal contaminants was observed in the presence of the starters.

  16. Burden of serious fungal infections in Guatemala.

    Science.gov (United States)

    Medina, N; Samayoa, B; Lau-Bonilla, D; Denning, D W; Herrera, R; Mercado, D; Guzmán, B; Pérez, J C; Arathoon, E

    2017-06-01

    Guatemala is a developing country in Central America with a high burden of HIV and endemic fungal infections; we attempted to estimate the burden of serious fungal infections for the country. A full literature search was done to identify epidemiology papers reporting fungal infections from Guatemala. We used specific populations at risk and fungal infection frequencies in the population to estimate national rates. The population of Guatemala in 2013 was 15.4 million; 40% were younger than 15 and 6.2% older than 60. There are an estimated 53,000 adults with HIV infection, in 2015, most presenting late. The estimated cases of opportunistic fungal infections were: 705 cases of disseminated histoplasmosis, 408 cases of cryptococcal meningitis, 816 cases of Pneumocystis pneumonia, 16,695 cases of oral candidiasis, and 4,505 cases of esophageal candidiasis. In the general population, an estimated 5,568 adult asthmatics have allergic bronchopulmonary aspergillosis (ABPA) based on a 2.42% prevalence of asthma and a 2.5% ABPA proportion. Amongst 2,452 pulmonary tuberculosis patients, we estimated a prevalence of 495 for chronic pulmonary aspergillosis in this group, and 1,484 for all conditions. An estimated 232,357 cases of recurrent vulvovaginal candidiasis is likely. Overall, 1.7% of the population are affected by these conditions. The true fungal infection burden in Guatemala is unknown. Tools and training for improved diagnosis are needed. Additional research on prevalence is needed to employ public health measures towards treatment and improving the reported data of fungal diseases.

  17. Influence of Media on Seasonal Influenza Epidemic Curves.

    Science.gov (United States)

    Saito, Satoshi; Saito, Norihiro; Itoga, Masamichi; Ozaki, Hiromi; Kimura, Toshiyuki; Okamura, Yuji; Murakami, Hiroshi; Kayaba, Hiroyuki

    2016-09-01

    Theoretical investigations predicting the epidemic curves of seasonal influenza have been demonstrated so far; however, there is little empirical research using ever accumulated epidemic curves. The effects of vaccine coverage and information distribution on influenza epidemics were evaluated. Four indices for epidemics (i.e., onset-peak duration, onset-end duration, ratio of the onset-peak duration to onset-end duration and steepness of epidemic curves) were defined, and the correlations between these indices and anti-flu drug prescription dose, vaccine coverage, the volume of media and search trend on influenza through internet were analyzed. Epidemiological data on seasonal influenza epidemics from 2002/2003 to 2013/2014 excluding 2009/2010 season were collected from National Institute of Infectious Diseases of Japan. The onset-peak duration and its ratio to onset-end duration correlated inversely with the volume of anti-flu drug prescription. Onset-peak duration correlated positively with media information volume on influenza. The steepness of the epidemic curve, and anti-flu drug prescription dose inversely correlated with the volume of media information. Pre-epidemic search trend and media volume on influenza correlated with the vaccine coverage in the season. Vaccine coverage had no strong effect on epidemic curve. Education through media has an effect on the epidemic curve of seasonal influenza. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  18. Defining and detecting malaria epidemics in south-east Iran

    Directory of Open Access Journals (Sweden)

    McKelvie William R

    2012-03-01

    Full Text Available Abstract Background A lack of consensus on how to define malaria epidemics has impeded the evaluation of early detection systems. This study aimed to develop local definitions of malaria epidemics in a known malarious area of Iran, and to use that definition to evaluate the validity of several epidemic alert thresholds. Methods Epidemic definition variables generated from surveillance data were plotted against weekly malaria counts to assess which most accurately labelled aberrations. Various alert thresholds were then generated from weekly counts or log counts. Finally, the best epidemic definition was used to calculate and compare sensitivities, specificities, detection delays, and areas under ROC curves of the alert thresholds. Results The best epidemic definition used a minimum duration of four weeks and week-specific and overall smoothed geometric means plus 1.0 standard deviation. It defined 13 epidemics. A modified C-SUM alert of untransformed weekly counts using a threshold of mean + 0.25 SD had the highest combined sensitivity and specificity. Untransformed C-SUM alerts also had the highest area under the ROC curve. Conclusions Defining local malaria epidemics using objective criteria facilitated the evaluation of alert thresholds. This approach needs further study to refine epidemic definitions and prospectively evaluate epidemic alerts.

  19. Defining and detecting malaria epidemics in south-east Iran.

    Science.gov (United States)

    McKelvie, William R; Haghdoost, Ali Akbar; Raeisi, Ahmad

    2012-03-23

    A lack of consensus on how to define malaria epidemics has impeded the evaluation of early detection systems. This study aimed to develop local definitions of malaria epidemics in a known malarious area of Iran, and to use that definition to evaluate the validity of several epidemic alert thresholds. Epidemic definition variables generated from surveillance data were plotted against weekly malaria counts to assess which most accurately labelled aberrations. Various alert thresholds were then generated from weekly counts or log counts. Finally, the best epidemic definition was used to calculate and compare sensitivities, specificities, detection delays, and areas under ROC curves of the alert thresholds. The best epidemic definition used a minimum duration of four weeks and week-specific and overall smoothed geometric means plus 1.0 standard deviation. It defined 13 epidemics. A modified C-SUM alert of untransformed weekly counts using a threshold of mean+0.25 SD had the highest combined sensitivity and specificity. Untransformed C-SUM alerts also had the highest area under the ROC curve. Defining local malaria epidemics using objective criteria facilitated the evaluation of alert thresholds. This approach needs further study to refine epidemic definitions and prospectively evaluate epidemic alerts.

  20. An epidemic model for the future progression of the current Haiti cholera epidemic

    Science.gov (United States)

    Bertuzzo, E.; Mari, L.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2012-04-01

    As a major cholera epidemic progresses in Haiti, and the figures of the infection, up to December 2011, climb to 522,000 cases and 7,000 deaths, the development of general models to track and predict the evolution of the outbreak, so as to guide the allocation of medical supplies and staff, is gaining notable urgency. We propose here a spatially explicit epidemic model that accounts for the dynamics of susceptible and infected individuals as well as the redistribution of Vibrio cholera, the causative agent of the disease, among different human communities. In particular, we model two spreading pathways: the advection of pathogens through hydrologic connections and the dissemination due to human mobility described by means of a gravity-like model. To this end the country has been divided into hydrologic units based on drainage directions derived from a digital terrain model. Moreover the population of each unit has been estimated from census data downscaled to 1 km x 1 km resolution via remotely sensed geomorphological information (LandScan project). The model directly accounts for the role of rainfall patterns in driving the seasonality of cholera outbreaks. The two main outbreaks in fact occurred during the rainy seasons (October and May) when extensive floodings severely worsened the sanitation conditions and, in turn, raised the risk of infection. The model capability to reproduce the spatiotemporal features of the epidemic up to date grants robustness to the foreseen future development. To this end, we generate realistic scenario of future precipitation in order to forecast possible epidemic paths up to the end of the 2013. In this context, the duration of acquired immunity, a hotly debated topic in the scientific community, emerges as a controlling factor for progression of the epidemic in the near future. The framework presented here can straightforwardly be used to evaluate the effectiveness of alternative intervention strategies like mass vaccinations

  1. Treatment of Fungal Bioaerosols by a High-Temperature, Short-Time Process in a Continuous-Flow System▿

    Science.gov (United States)

    Jung, Jae Hee; Lee, Jung Eun; Lee, Chang Ho; Kim, Sang Soo; Lee, Byung Uk

    2009-01-01

    Airborne fungi, termed fungal bioaerosols, have received attention due to the association with public health problems and the effects on living organisms in nature. There are growing concerns that fungal bioaerosols are relevant to the occurrence of allergies, opportunistic diseases in hospitals, and outbreaks of plant diseases. The search for ways of preventing and curing the harmful effects of fungal bioaerosols has created a high demand for the study and development of an efficient method of controlling bioaerosols. However, almost all modern microbiological studies and theories have focused on microorganisms in liquid and solid phases. We investigated the thermal heating effects on fungal bioaerosols in a continuous-flow environment. Although the thermal heating process has long been a traditional method of controlling microorganisms, the effect of a continuous high-temperature, short-time (HTST) process on airborne microorganisms has not been quantitatively investigated in terms of various aerosol properties. Our experimental results show that the geometric mean diameter of the tested fungal bioaerosols decreased when they were exposed to increases in the surrounding temperature. The HTST process produced a significant decline in the (1→3)-β-d-glucan concentration of fungal bioaerosols. More than 99% of the Aspergillus versicolor and Cladosporium cladosporioides bioaerosols lost their culturability in about 0.2 s when the surrounding temperature exceeded 350°C and 400°C, respectively. The instantaneous exposure to high temperature significantly changed the surface morphology of the fungal bioaerosols. PMID:19201954

  2. Treatment of fungal bioaerosols by a high-temperature, short-time process in a continuous-flow system.

    Science.gov (United States)

    Jung, Jae Hee; Lee, Jung Eun; Lee, Chang Ho; Kim, Sang Soo; Lee, Byung Uk

    2009-05-01

    Airborne fungi, termed fungal bioaerosols, have received attention due to the association with public health problems and the effects on living organisms in nature. There are growing concerns that fungal bioaerosols are relevant to the occurrence of allergies, opportunistic diseases in hospitals, and outbreaks of plant diseases. The search for ways of preventing and curing the harmful effects of fungal bioaerosols has created a high demand for the study and development of an efficient method of controlling bioaerosols. However, almost all modern microbiological studies and theories have focused on microorganisms in liquid and solid phases. We investigated the thermal heating effects on fungal bioaerosols in a continuous-flow environment. Although the thermal heating process has long been a traditional method of controlling microorganisms, the effect of a continuous high-temperature, short-time (HTST) process on airborne microorganisms has not been quantitatively investigated in terms of various aerosol properties. Our experimental results show that the geometric mean diameter of the tested fungal bioaerosols decreased when they were exposed to increases in the surrounding temperature. The HTST process produced a significant decline in the (1-->3)-beta-d-glucan concentration of fungal bioaerosols. More than 99% of the Aspergillus versicolor and Cladosporium cladosporioides bioaerosols lost their culturability in about 0.2 s when the surrounding temperature exceeded 350 degrees C and 400 degrees C, respectively. The instantaneous exposure to high temperature significantly changed the surface morphology of the fungal bioaerosols.

  3. Dynamics of arbuscular mycorrhizal fungal community structure and functioning along a nitrogen enrichment gradient in an alpine meadow ecosystem.

    Science.gov (United States)

    Jiang, Shengjing; Liu, Yongjun; Luo, Jiajia; Qin, Mingsen; Johnson, Nancy Collins; Öpik, Maarja; Vasar, Martti; Chai, Yuxing; Zhou, Xiaolong; Mao, Lin; Du, Guozhen; An, Lizhe; Feng, Huyuan

    2018-03-30

    Nitrogen (N) availability is increasing dramatically in many ecosystems, but the influence of elevated N on the functioning of arbuscular mycorrhizal (AM) fungi in natural ecosystems is not well understood. We measured AM fungal community structure and mycorrhizal function simultaneously across an experimental N addition gradient in an alpine meadow that is limited by N but not by phosphorus (P). AM fungal communities at both whole-plant-community (mixed roots) and single-plant-species (Elymus nutans roots) scales were described using pyro-sequencing, and the mycorrhizal functioning was quantified using a mycorrhizal-suppression treatment in the field (whole-plant-community scale) and a glasshouse inoculation experiment (single-plant-species scale). Nitrogen enrichment progressively reduced AM fungal abundance, changed AM fungal community composition, and shifted mycorrhizal functioning towards parasitism at both whole-plant-community and E. nutans scales. N-induced shifts in AM fungal community composition were tightly linked to soil N availability and/or plant species richness, whereas the shifts in mycorrhizal function were associated with the communities of specific AM fungal lineages. The observed changes in both AM fungal community structure and functioning across an N enrichment gradient highlight that N enrichment of ecosystems that are not P-limited can induce parasitic mycorrhizal functioning and influence plant community structure and ecosystem sustainability. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  4. Fungal Genomics for Energy and Environment

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor V.

    2013-03-11

    Genomes of fungi relevant to energy and environment are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). One of its projects, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts) by means of genome sequencing and analysis. New chapters of the Encyclopedia can be opened with user proposals to the JGI Community Sequencing Program (CSP). Another JGI project, the 1000 fungal genomes, explores fungal diversity on genome level at scale and is open for users to nominate new species for sequencing. Over 200 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such parts suggested by comparative genomics and functional analysis in these areas are presented here.

  5. Fungal endophytes for sustainable crop production.

    Science.gov (United States)

    Lugtenberg, Ben J J; Caradus, John R; Johnson, Linda J

    2016-12-01

    This minireview highlights the importance of endophytic fungi for sustainable agriculture and horticulture production. Fungal endophytes play a key role in habitat adaptation of plants resulting in improved plant performance and plant protection against biotic and abiotic stresses. They encode a vast variety of novel secondary metabolites including volatile organic compounds. In addition to protecting plants against pathogens and pests, selected fungal endophytes have been used to remove animal toxicities associated with fungal endophytes in temperate grasses, to create corn and rice plants that are tolerant to a range of biotic and abiotic stresses, and for improved management of post-harvest control. We argue that practices used in plant breeding, seed treatments and agriculture, often caused by poor knowledge of the importance of fungal endophytes, are among the reasons for the loss of fungal endophyte diversity in domesticated plants and also accounts for the reduced effectiveness of some endophyte strains to confer plant benefits. We provide recommendations on how to mitigate against these negative impacts in modern agriculture. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Fueling the Future with Fungal Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor V.

    2014-10-27

    Genomes of fungi relevant to energy and environment are in focus of the JGI Fungal Genomic Program. One of its projects, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts and pathogens) and biorefinery processes (cellulose degradation and sugar fermentation) by means of genome sequencing and analysis. New chapters of the Encyclopedia can be opened with user proposals to the JGI Community Science Program (CSP). Another JGI project, the 1000 fungal genomes, explores fungal diversity on genome level at scale and is open for users to nominate new species for sequencing. Over 400 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics will lead to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such ‘parts’ suggested by comparative genomics and functional analysis in these areas are presented here.

  7. Reverse-feeding effect of epidemic by propagators in two-layered networks

    Science.gov (United States)

    Dayu, Wu; Yanping, Zhao; Muhua, Zheng; Jie, Zhou; Zonghua, Liu

    2016-02-01

    Epidemic spreading has been studied for a long time and is currently focused on the spreading of multiple pathogens, especially in multiplex networks. However, little attention has been paid to the case where the mutual influence between different pathogens comes from a fraction of epidemic propagators, such as bisexual people in two separated groups of heterosexual and homosexual people. We here study this topic by presenting a network model of two layers connected by impulsive links, in contrast to the persistent links in each layer. We let each layer have a distinct pathogen and their interactive infection is implemented by a fraction of propagators jumping between the corresponding pairs of nodes in the two layers. By this model we show that (i) the propagators take the key role to transmit pathogens from one layer to the other, which significantly influences the stabilized epidemics; (ii) the epidemic thresholds will be changed by the propagators; and (iii) a reverse-feeding effect can be expected when the infective rate is smaller than its threshold of isolated spreading. A theoretical analysis is presented to explain the numerical results. Project supported by the National Natural Science Foundation of China (Grant Nos. 11135001, 11375066, and 11405059) and the National Basic Key Program of China (Grant No. 2013CB834100).

  8. Evolution of scaling emergence in large-scale spatial epidemic spreading.

    Science.gov (United States)

    Wang, Lin; Li, Xiang; Zhang, Yi-Qing; Zhang, Yan; Zhang, Kan

    2011-01-01

    Zipf's law and Heaps' law are two representatives of the scaling concepts, which play a significant role in the study of complexity science. The coexistence of the Zipf's law and the Heaps' law motivates different understandings on the dependence between these two scalings, which has still hardly been clarified. In this article, we observe an evolution process of the scalings: the Zipf's law and the Heaps' law are naturally shaped to coexist at the initial time, while the crossover comes with the emergence of their inconsistency at the larger time before reaching a stable state, where the Heaps' law still exists with the disappearance of strict Zipf's law. Such findings are illustrated with a scenario of large-scale spatial epidemic spreading, and the empirical results of pandemic disease support a universal analysis of the relation between the two laws regardless of the biological details of disease. Employing the United States domestic air transportation and demographic data to construct a metapopulation model for simulating the pandemic spread at the U.S. country level, we uncover that the broad heterogeneity of the infrastructure plays a key role in the evolution of scaling emergence. The analyses of large-scale spatial epidemic spreading help understand the temporal evolution of scalings, indicating the coexistence of the Zipf's law and the Heaps' law depends on the collective dynamics of epidemic processes, and the heterogeneity of epidemic spread indicates the significance of performing targeted containment strategies at the early time of a pandemic disease.

  9. Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest

    Science.gov (United States)

    Terhonen, Eeva; Kovalchuk, Andriy; Tuovila, Hanna; Chen, Hongxin; Oghenekaro, Abbot O.; Heinonsalo, Jussi; Kohler, Annegret; Kasanen, Risto; Vasander, Harri; Asiegbu, Fred O.

    2016-01-01

    Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands. PMID:26896139

  10. Simultaneous Chronic Invasive Fungal Infection and Tracheal Fungus Ball Mimicking Cancer in an Immunocompetent Patient

    Directory of Open Access Journals (Sweden)

    Erdoğan Çetinkaya

    2016-01-01

    Full Text Available Fungal infections of the lung are uncommon and mainly affect people with immune deficiency. There are crucial problems in the diagnosis and treatment of this condition. Invasive pulmonary aspergillosis and candidiasis are the most common opportunistic fungal infections. Aspergillus species (spp. are saprophytes molds that exist in nature as spores and rarely cause disease in immunocompetent individuals. In patients with immune deficiency or chronic lung disease, such as cavitary lung disease or bronchiectasis, Aspergillus may cause a variety of aspergillosis infections. Here we present a case of a 57-year-old patient without immunodeficiency or chronic lung disease who was diagnosed with endotracheal fungus ball and chronic fungal infection, possibly due to Aspergillus. Bronchoscopic examination showed a paralyzed right vocal cord and vegetating mass that was yellow in color, at the posterior wall of tracheal lumen. After 3 months, both the parenchymal and tracheal lesions were completely resolved.

  11. Bromelain, a cysteine protease from pineapple (Ananas comosus) stem, is an inhibitor of fungal plant pathogens.

    Science.gov (United States)

    López-García, B; Hernández, M; Segundo, B S

    2012-07-01

    This study aimed to evaluate the effect of bromelain, a cysteine protease isolated from pineapple (Ananas comosus), on growth of several agronomically important fungal pathogens. Purification of bromelain from pineapple stems was carried out by chromatography techniques, and its antimicrobial activity was tested against the fungal pathogens Fusarium verticillioides, Fusarium oxysporum and Fusarium proliferatum by broth microdilution assay. A concentration of 0.3 μmol l(-1) of bromelain was sufficient for 90% growth inhibition of F. verticillioides. The capability of bromelain to inhibit fungal growth is related to its proteolytic activity. The study demonstrates that stem bromelain exhibits a potent antifungal activity against phytopathogens and suggests its potential use as an effective agent for crop protection. The results support the use of a natural protease that accumulates at high levels in pineapple stems as alternative to the use of chemical fungicides for crop protection. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

  12. Scale-dependent climatic drivers of human epidemics in ancient China

    Czech Academy of Sciences Publication Activity Database

    Tian, H.; Yan, Ch.; Xu, L.; Büntgen, Ulf; Stenseth, N. C.; Zhang, Z.

    2017-01-01

    Roč. 114, č. 49 (2017), s. 12970-12975 ISSN 0027-8424 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : infectious-diseases * northern-hemisphere * cholera dynamics * time-series * 2 millennia * reconstruction * variability * management * plague * ad * epidemics * climate * scale dependent * natural disaster * disease Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 9.661, year: 2016

  13. Dynamical Interplay between Awareness and Epidemic Spreading in Multiplex Networks

    Science.gov (United States)

    Granell, Clara; Gómez, Sergio; Arenas, Alex

    2013-09-01

    We present the analysis of the interrelation between two processes accounting for the spreading of an epidemic, and the information awareness to prevent its infection, on top of multiplex networks. This scenario is representative of an epidemic process spreading on a network of persistent real contacts, and a cyclic information awareness process diffusing in the network of virtual social contacts between the same individuals. The topology corresponds to a multiplex network where two diffusive processes are interacting affecting each other. The analysis using a microscopic Markov chain approach reveals the phase diagram of the incidence of the epidemics and allows us to capture the evolution of the epidemic threshold depending on the topological structure of the multiplex and the interrelation with the awareness process. Interestingly, the critical point for the onset of the epidemics has a critical value (metacritical point) defined by the awareness dynamics and the topology of the virtual network, from which the onset increases and the epidemics incidence decreases.

  14. Dynamical interplay between awareness and epidemic spreading in multiplex networks.

    Science.gov (United States)

    Granell, Clara; Gómez, Sergio; Arenas, Alex

    2013-09-20

    We present the analysis of the interrelation between two processes accounting for the spreading of an epidemic, and the information awareness to prevent its infection, on top of multiplex networks. This scenario is representative of an epidemic process spreading on a network of persistent real contacts, and a cyclic information awareness process diffusing in the network of virtual social contacts between the same individuals. The topology corresponds to a multiplex network where two diffusive processes are interacting affecting each other. The analysis using a microscopic Markov chain approach reveals the phase diagram of the incidence of the epidemics and allows us to capture the evolution of the epidemic threshold depending on the topological structure of the multiplex and the interrelation with the awareness process. Interestingly, the critical point for the onset of the epidemics has a critical value (metacritical point) defined by the awareness dynamics and the topology of the virtual network, from which the onset increases and the epidemics incidence decreases.

  15. Disease spreading with epidemic alert on small-world networks

    International Nuclear Information System (INIS)

    Han, Xiao-Pu

    2007-01-01

    Base on two-dimension small-world networks, a susceptible-infected model with epidemic alert is proposed in this Letter. In this model, if some parts of the network are alarmed as dangerous, a fraction of edges between the alarmed parts and others will be removed, and two cases of alerting rules that the degree and frequency of contacts kept unchanged are considered respectively. The numerical simulations show that the spreading velocity is reduced by the accurate and timely epidemic alert, and the more accurate and timely, the stronger the deceleration effect. This model indicates that to broadcast epidemic alert timely is helpful and necessary in the control of epidemic spreading, and in agreement with the general view of epidemic alert. This work is helpful to understand the effects of epidemic alert on disease spreading

  16. Cotton plants export microRNAs to inhibit virulence gene expression in a fungal pathogen.

    Science.gov (United States)

    Zhang, Tao; Zhao, Yun-Long; Zhao, Jian-Hua; Wang, Sheng; Jin, Yun; Chen, Zhong-Qi; Fang, Yuan-Yuan; Hua, Chen-Lei; Ding, Shou-Wei; Guo, Hui-Shan

    2016-09-26

    Plant pathogenic fungi represent the largest group of disease-causing agents on crop plants, and are a constant and major threat to agriculture worldwide. Recent studies have shown that engineered production of RNA interference (RNAi)-inducing dsRNA in host plants can trigger specific fungal gene silencing and confer resistance to fungal pathogens 1-7 . Although these findings illustrate efficient uptake of host RNAi triggers by pathogenic fungi, it is unknown whether or not such an uptake mechanism has been evolved for a natural biological function in fungus-host interactions. Here, we show that in response to infection with Verticillium dahliae (a vascular fungal pathogen responsible for devastating wilt diseases in many crops) cotton plants increase production of microRNA 166 (miR166) and miR159 and export both to the fungal hyphae for specific silencing. We found that two V. dahliae genes encoding a Ca 2+ -dependent cysteine protease (Clp-1) and an isotrichodermin C-15 hydroxylase (HiC-15), and targeted by miR166 and miR159, respectively, are both essential for fungal virulence. Notably, V. dahliae strains expressing either Clp-1 or HiC-15 rendered resistant to the respective miRNA exhibited drastically enhanced virulence in cotton plants. Together, our findings identify a novel defence strategy of host plants by exporting specific miRNAs to induce cross-kingdom gene silencing in pathogenic fungi and confer disease resistance.

  17. Anti-Fungal activity of essential oil from Baeckea frutescens L against Pleuratus ostreatus

    Science.gov (United States)

    Jemi, Renhart; Barus, Ade Irma; Nuwa, Sarinah, Luhan, Gimson

    2017-11-01

    Ujung Atap is an herb that have distinctive odor on its leaves. The plant's essential oil contains bioactive compounds but has not been investigated its anti-fungal activity against Pleurotus ostreatus. Essential oil from Ujung Atap leaves is one environmentally friendly natural preservative. This study consisted of distillation Ujung Atap leaves with boiled method, determining the number of acid, essential oil ester, and anti-fungal activity against Pleurotus ostreatus. Analysis of the data to calculate anti-fungal activity used probit analysis method to determine the IC50. Results for the distillation of leaves Ujung Atap produce essential oil yield of 0.071% and the average yield of the acid number and the ester of essential oils Ujung Atap leaves are 5.24 and 12.15. Anti-fungal activity Pleurotus ostreatus at a concentration of 1000 µg/mL, 100 µg/mL, 75 µg/mL, 50 µg/mL and 100 µg/mL BA defunct or fungi was declared dead, while at a concentration of 25 µg/mL, 10 µg/mL and 5 µg/mL still occur inhibitory processes. Results obtained probit analysis method IC50 of 35.48 mg/mL; means the essential oil of Ujung Atap leaf can inhibit fungal growth by 50 percent to 35.48 µg/mL concentration.

  18. Quantification of arbuscular mycorrhizal fungal DNA in roots: how important is material preservation?

    Science.gov (United States)

    Janoušková, Martina; Püschel, David; Hujslová, Martina; Slavíková, Renata; Jansa, Jan

    2015-04-01

    Monitoring populations of arbuscular mycorrhizal fungi (AMF) in roots is a pre-requisite for improving our understanding of AMF ecology and functioning of the symbiosis in natural conditions. Among other approaches, quantification of fungal DNA in plant tissues by quantitative real-time PCR is one of the advanced techniques with a great potential to process large numbers of samples and to deliver truly quantitative information. Its application potential would greatly increase if the samples could be preserved by drying, but little is currently known about the feasibility and reliability of fungal DNA quantification from dry plant material. We addressed this question by comparing quantification results based on dry root material to those obtained from deep-frozen roots of Medicago truncatula colonized with Rhizophagus sp. The fungal DNA was well conserved in the dry root samples with overall fungal DNA levels in the extracts comparable with those determined in extracts of frozen roots. There was, however, no correlation between the quantitative data sets obtained from the two types of material, and data from dry roots were more variable. Based on these results, we recommend dry material for qualitative screenings but advocate using frozen root materials if precise quantification of fungal DNA is required.

  19. The spatial resolution of epidemic peaks.

    Directory of Open Access Journals (Sweden)

    Harriet L Mills

    2014-04-01

    Full Text Available The emergence of novel respiratory pathogens can challenge the capacity of key health care resources, such as intensive care units, that are constrained to serve only specific geographical populations. An ability to predict the magnitude and timing of peak incidence at the scale of a single large population would help to accurately assess the value of interventions designed to reduce that peak. However, current disease-dynamic theory does not provide a clear understanding of the relationship between: epidemic trajectories at the scale of interest (e.g. city; population mobility; and higher resolution spatial effects (e.g. transmission within small neighbourhoods. Here, we used a spatially-explicit stochastic meta-population model of arbitrary spatial resolution to determine the effect of resolution on model-derived epidemic trajectories. We simulated an influenza-like pathogen spreading across theoretical and actual population densities and varied our assumptions about mobility using Latin-Hypercube sampling. Even though, by design, cumulative attack rates were the same for all resolutions and mobilities, peak incidences were different. Clear thresholds existed for all tested populations, such that models with resolutions lower than the threshold substantially overestimated population-wide peak incidence. The effect of resolution was most important in populations which were of lower density and lower mobility. With the expectation of accurate spatial incidence datasets in the near future, our objective was to provide a framework for how to use these data correctly in a spatial meta-population model. Our results suggest that there is a fundamental spatial resolution for any pathogen-population pair. If underlying interactions between pathogens and spatially heterogeneous populations are represented at this resolution or higher, accurate predictions of peak incidence for city-scale epidemics are feasible.

  20. Molecular Diagnostics for Soilborne Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    E.J. Paplomatas

    2004-08-01

    Full Text Available Several classical approaches have been developed to detect and identify soil fungal inhabitants through the years. Selective media have been devised to exclude the large number of soil organisms and allow growth of target fungi. However the advent of molecular biology has offered a number of revolutionary insights into the detection and enumeration of soilborne fungal pathogens and also has started to provide information on the identification of unknown species from DNA sequences. This review paper focuses on the application of various molecular techniques in the detection, identification, characterization and quantification of soilborne fungal plant pathogens. This is based on information from the literature and is combined with personal research findings of the author.

  1. Epidemics on adaptive networks with geometric constraints

    Science.gov (United States)

    Shaw, Leah; Schwartz, Ira

    2008-03-01

    When a population is faced with an epidemic outbreak, individuals may modify their social behavior to avoid exposure to the disease. Recent work has considered models in which the contact network is rewired dynamically so that susceptibles avoid contact with infectives. We consider extensions in which the rewiring is subject to constraints that preserve key properties of the social network structure. Constraining to a fixed degree distribution destroys previously observed bistable behavior. The most effective rewiring strategy is found to depend on the spreading rate.

  2. Generalized epidemic process on modular networks.

    Science.gov (United States)

    Chung, Kihong; Baek, Yongjoo; Kim, Daniel; Ha, Meesoon; Jeong, Hawoong

    2014-05-01

    Social reinforcement and modular structure are two salient features observed in the spreading of behavior through social contacts. In order to investigate the interplay between these two features, we study the generalized epidemic process on modular networks with equal-sized finite communities and adjustable modularity. Using the analytical approach originally applied to clique-based random networks, we show that the system exhibits a bond-percolation type continuous phase transition for weak social reinforcement, whereas a discontinuous phase transition occurs for sufficiently strong social reinforcement. Our findings are numerically verified using the finite-size scaling analysis and the crossings of the bimodality coefficient.

  3. CHEMICAL VERSUS SERUM TREATMENT OF EPIDEMIC MENINGITIS.

    Science.gov (United States)

    Flexner, S; Amoss, H L

    1916-05-01

    Claims of efficiency have been made at two widely separated periods for the chemical treatment of epidemic meningitis, in the first instance for lysol and in the second for protargol. The use of lysol was long since abandoned; the recommendation for protargol is based on a single series of cases, small in number. Because of the variable severity of epidemics of meningitis, small reliance can be placed on results of treatment limited in extent to small numbers of cases and to one locality. A more uniform and accurate measure of the value of a method of treatment is provided by animals infected experimentally with pathogenic cultures of meningococci. Young guinea pigs respond in a definite manner to intraperitoneal inoculation of virulent meningococci. Neither protargol nor lysol proved to have any curative action on the experimental infection thus produced in these animals. Monkeys respond in a characteristic manner to the inoculation of virulent cultures into the subarachnoid space. Protargol displayed no curative action on the experimental infection thus produced in these animals. On the contrary, both lysol and protargol exert antileukotactic and antiphagocytic effects, and are also potent protoplasmic poisons, and the leukocytes with which they come in contact are injured and made to degenerate. According to the extent to which these harmful properties are exerted, the chemicals promote the advance rather than restrain the progress of meningococcic infection. Recovery from meningococcic infection in man and animals is accomplished chiefly through the process of phagocytosis. The specific antiserum acts curatively by increasing the emigration of leukocytes, by promoting phagocytosis directly, and by agglutinating the meningococci, and also by neutralizing endotoxin. Any means which interfere with and reduce these essential processes retard or prevent recovery. Both lysol and protargol interfere with and diminish the emigration of leukocytes and the phagocytosis

  4. Two approaches to forecast Ebola synthetic epidemics.

    Science.gov (United States)

    Champredon, David; Li, Michael; Bolker, Benjamin M; Dushoff, Jonathan

    2018-03-01

    We use two modelling approaches to forecast synthetic Ebola epidemics in the context of the RAPIDD Ebola Forecasting Challenge. The first approach is a standard stochastic compartmental model that aims to forecast incidence, hospitalization and deaths among both the general population and health care workers. The second is a model based on the renewal equation with latent variables that forecasts incidence in the whole population only. We describe fitting and forecasting procedures for each model and discuss their advantages and drawbacks. We did not find that one model was consistently better in forecasting than the other. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  5. Heterogeneous Epidemic Model for Assessing Data Dissemination in Opportunistic Networks

    DEFF Research Database (Denmark)

    Rozanova, Liudmila; Alekseev, Vadim; Temerev, Alexander

    2014-01-01

    that amount of data transferred between network nodes possesses a Pareto distribution, implying scale-free properties. In this context, more heterogeneity in susceptibility means the less severe epidemic progression, and, on the contrary, more heterogeneity in infectivity leads to more severe epidemics...... — assuming that the other parameter (either heterogeneity or susceptibility) stays fixed. The results are general enough to be useful for estimating the epidemic progression with no significant acquired immunity — in the cases where Pareto distribution holds....

  6. Hybrid epidemic spreading - from Internet worms to HIV infection

    OpenAIRE

    Zhang, C.

    2015-01-01

    Epidemic phenomena are ubiquitous, ranging from infectious diseases, computer viruses, to information dissemination. Epidemics have traditionally been studied as a single spreading process, either in a fully mixed population or on a network. Many epidemics, however, are hybrid, employing more than one spreading mechanism. For example, the Internet worm Conficker spreads locally targeting neighbouring computers in local networks as well as globally by randomly probing any computer on the Inter...

  7. Epidemic dynamics and endemic states in complex networks

    OpenAIRE

    Pastor-Satorras, Romualdo; Vespignani, Alessandro

    2001-01-01

    We study by analytical methods and large scale simulations a dynamical model for the spreading of epidemics in complex networks. In networks with exponentially bounded connectivity we recover the usual epidemic behavior with a threshold defining a critical point below which the infection prevalence is null. On the contrary, on a wide range of scale-free networks we observe the absence of an epidemic threshold and its associated critical behavior. This implies that scale-free networks are pron...

  8. Optimal Control of Interdependent Epidemics in Complex Networks

    OpenAIRE

    Chen, Juntao; Zhang, Rui; Zhu, Quanyan

    2017-01-01

    Optimal control of interdependent epidemics spreading over complex networks is a critical issue. We first establish a framework to capture the coupling between two epidemics, and then analyze the system's equilibrium states by categorizing them into three classes, and deriving their stability conditions. The designed control strategy globally optimizes the trade-off between the control cost and the severity of epidemics in the network. A gradient descent algorithm based on a fixed point itera...

  9. Fungal Secretome Analysis via PepSAVI-MS: Identification of the Bioactive Peptide KP4 from Ustilago maydis

    Science.gov (United States)

    Kirkpatrick, Christine L.; Parsley, Nicole C.; Bartges, Tessa E.; Cooke, Madeline E.; Evans, Wilaysha S.; Heil, Lilian R.; Smith, Thomas J.; Hicks, Leslie M.

    2018-05-01

    Fungal secondary metabolites represent a rich and largely untapped source for bioactive molecules, including peptides with substantial structural diversity and pharmacological potential. As methods proceed to take a deep dive into fungal genomes, complimentary methods to identify bioactive components are required to keep pace with the expanding fungal repertoire. We developed PepSAVI-MS to expedite the search for natural product bioactive peptides and herein demonstrate proof-of-principle applicability of the pipeline for the discovery of bioactive peptides from fungal secretomes via identification of the antifungal killer toxin KP4 from Ustilago maydis P4. This work opens the door to investigating microbial secretomes with a new lens, and could have broad applications across human health, agriculture, and food safety. [Figure not available: see fulltext.

  10. Lignin depolymerization by fungal secretomes and a microbial sink

    Energy Technology Data Exchange (ETDEWEB)

    Salvachúa, Davinia; Katahira, Rui; Cleveland, Nicholas S.; Khanna, Payal; Resch, Michael G.; Black, Brenna A.; Purvine, Samuel O.; Zink, Erika M.; Prieto, Alicia; Martínez, María J.; Martínez, Angel T.; Simmons, Blake A.; Gladden, John M.; Beckham, Gregg T.

    2016-08-25

    In Nature, powerful oxidative enzymes secreted by white rot fungi and some bacteria catalyze lignin depolymerization and some microbes are able to catabolize the resulting aromatic compounds as carbon and energy sources. Taken together, these two processes offer a potential route for microbial valorization of lignin. However, many challenges remain in realizing this concept, including that oxidative enzymes responsible for lignin depolymerization also catalyze polymerization of low molecular weight (LMW) lignin. Here, multiple basidiomycete secretomes were screened for ligninolytic enzyme activities in the presence of a residual lignin solid stream from a corn stover biorefinery, dubbed DMR-EH (Deacetylation, Mechanical Refining, and Enzymatic Hydrolysis) lignin. Two selected fungal secretomes, with high levels of laccases and peroxidases, were utilized for DMR-EH lignin depolymerization assays. The secretome from Pleurotus eryngii, which exhibited the highest laccase activity, reduced the lignin average molecular weight by 63% and 75% at pH 7 compared to the Mw of the control treated at the same conditions and the initial DMR-EH lignin, respectively, and was applied in further depolymerization assays as a function of time. As repolymerization was observed after 3 days of incubation, an aromatic-catabolic microbe (Pseudomonas putida KT2440) was incubated with the fungal secretome and DMR-EH lignin. These experiments demonstrated that the presence of the bacterium enhances lignin depolymerization, likely due to bacterial catabolism of LMW lignin, which may partially prevent repolymerization. In addition, proteomics was also applied to the P. eryngii secretome to identify the enzymes present in the fungal cocktail utilized for the depolymerization assays, which highlighted a significant number of glucose/ methanol/choline (GMC) oxidoreductases and laccases. Overall, this study demonstrates that ligninolytic enzymes can be used to partially depolymerize a solid, high

  11. Fungal Responses to Anthropogenic N Deposition: A Historical Perspective

    Science.gov (United States)

    Cline, L.; Gutknecht, J.; Kennedy, P.

    2017-12-01

    Fungi mediate primary productivity via the decay of organic matter and the formation of mycorrhizal associations. Short-term experimental manipulations reveal that nitrogen (N) addition slows decomposition and decreases plant reliance on fungal symbionts. However, it remains unclear if the responses observed in experimental systems apply to natural forests, where the addition of N via atmospheric deposition has taken place over much longer time periods. To address this discrepancy, we measured N concentration and isotopic composition in leaf and sporocarp tissue of herbarium specimens collected over the last 120 years in the Twin Cities metropolitan area of Minnesota, USA. We selected specimens from two fungal genera (Marasmius, Amanita) and two plant genera (Acer, Betula) due to their differing ability to form ectomycorrhizal associations as well as extensive representation in the UMN Bell Museum collections (1890 - 2010). Independent of taxonomy and mycorrhizal association, we observed consistent and significant decreases in foliar δ15N and sporocarp δ15N values through time (mixed effects model; b = -0.046; F = 42.0; P fungi ; r2 = 0.10 P = 0.085), despite no significant change in Amanita (ectomycorrhizal fungi) or Acer (non-mycorrhizal host) N content. The declining foliar δ15N and foliar N concentrations suggest that despite significant atmospheric N input during the latter half of the 20th century, soil N availability in MN forests has actually declined. Furthermore, concomitant declines in foliar and sporocarp δ15N did not indicate a shrinking fungal role in temperate forest N cycling. We hypothesize that interactions among global change agents (i.e., N deposition and elevated atmospheric CO2) may be leading to enhanced ecosystem N sequestration and progressive N limitation. Collectively, these results suggest that short-term experimental studies may not accurately reflect the cumulative effects of background N addition via deposition in temperate forest

  12. Mucormycosis: a devastating fungal infection in diabetics

    International Nuclear Information System (INIS)

    Rashid, M.; Bari, A.; Mehmood, S.; Tariq, K.M.; Haq, I.; Niwaz, Z.

    2005-01-01

    Mucormycosis is a highly invasive, devastating and usually fatal fungal infection of the sinuses, brain, or lungs that occurs primarily in people with immune disorders. Despite advances in diagnosis and treatment, a high mortality still exists. We present a middle aged diabetic male with this serious fungal infection involving nose, paranasal area and adjacent periorbital regions with a high risk of progressing further towards the dura mater. He was promptly diagnosed and managed with serial surgical debridements with systemic antifungals and was later fitted with a nasal prosthesis. (author)

  13. Fungal infections of the lung in children

    Energy Technology Data Exchange (ETDEWEB)

    Toma, Paolo; Colafati, Giovanna Stefania; D' Andrea, Maria Luisa [IRCCS Bambino Gesu Children' s Hospital, Department of Imaging, Rome (Italy); Bertaina, Alice; Mastronuzzi, Angela [IRCCS Bambino Gesu Children' s Hospital, Department of Pediatric Hematology/Oncology and Transfusion Medicine, Rome (Italy); Castagnola, Elio [IRCCS Istituto Giannina Gaslini, Department of Infective Diseases, Genoa (Italy); Finocchi, Andrea [IRCCS Bambino Gesu Children' s Hospital, Department of Pediatrics, Rome (Italy); Lucidi, Vincenzina [IRCCS Bambino Gesu Children' s Hospital, Cystic Fibrosis Center, Rome (Italy); Granata, Claudio [IRCCS Istituto Giannina Gaslini, Department of Pediatric Radiology, Genoa (Italy)

    2016-12-15

    Fungal infections of the lungs are relatively common and potentially life-threatening conditions in immunocompromised children. The role of imaging in children with lung mycosis is to delineate the extension of pulmonary involvement, to assess response to therapy, and to monitor for adverse sequelae such as bronchiectasis and cavitation. The aim of this paper is to show imaging findings in a series of patients with fungal pneumonia from two tertiary children's hospitals, to discuss differential diagnoses and to show how imaging findings can vary depending on the host immune response. (orig.)

  14. Epidemics: Lessons from the past and current patterns of response

    Science.gov (United States)

    Martin, Paul

    2008-09-01

    Hippocrates gave the term 'epidemic' its medical meaning. From antiquity to modern times, the meaning of the word epidemic has continued to evolve. Over the centuries, researchers have reached an understanding of the varying aspects of epidemics and have tried to combat them. The role played by travel, trade, and human exchanges in the propagation of epidemic infectious diseases has been understood. In 1948, the World Health Organization was created and given the task of advancing ways of combating epidemics. An early warning system to combat epidemics has been implemented by the WHO. The Global Outbreak Alert and Response Network (GOARN) is collaboration between existing institutions and networks that pool their human and technical resources to fight outbreaks. Avian influenza constitutes currently the most deadly epidemic threat, with fears that it could rapidly reach pandemic proportions and put several thousands of lives in jeopardy. Thanks to the WHO's support, most of the world's countries have mobilised and implemented an 'Action Plan for Pandemic Influenza'. As a result, most outbreaks of the H5N1 avian flu virus have so far been speedily contained. Cases of dengue virus introduction in countries possessing every circumstance required for its epidemic spread provide another example pertinent to the prevention of epidemics caused by vector-borne pathogens.

  15. Abia State HIV epidemic and response: challenges and prospects.

    Science.gov (United States)

    Onyeonoro, Ugochukwu Uchenna; Emelumadu, Obiageli Fidelia; Nwamoh, Uche Ngozi; Ukegbu, Andrew Ugwunna; Okafor, Godwin Oc

    2014-11-13

    Since the first seroprevalence survey in 1999, the HIV prevalence in Abia State has increased from 1.8% to 7.3% in 2010. The state is currently experiencing a generalized epidemic, with most transmission occurring through heterosexual low-risk sex. Drivers of the epidemic include low knowledge of HIV prevention, low risk perception, predominantly male factor-driven risky sexual behavior, and low condom use. This study reviewed the state HIV epidemic trend in relation to response, sought to identify the gaps between the epidemic and response, and recommended measures to strengthen the state response.

  16. Epidemic spreading on random surfer networks with infected avoidance strategy

    International Nuclear Information System (INIS)

    Feng Yun; Ding Li; Huang Yun-Han; Guan Zhi-Hong

    2016-01-01

    In this paper, we study epidemic spreading on random surfer networks with infected avoidance (IA) strategy. In particular, we consider that susceptible individuals’ moving direction angles are affected by the current location information received from infected individuals through a directed information network. The model is mainly analyzed by discrete-time numerical simulations. The results indicate that the IA strategy can restrain epidemic spreading effectively. However, when long-distance jumps of individuals exist, the IA strategy’s effectiveness on restraining epidemic spreading is heavily reduced. Finally, it is found that the influence of the noises from information transferring process on epidemic spreading is indistinctive. (paper)

  17. Epidemic spreading in time-varying community networks.

    Science.gov (United States)

    Ren, Guangming; Wang, Xingyuan

    2014-06-01

    The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold qc. The epidemic will survive when q > qc and die when q epidemic spreading in complex networks with community structure.

  18. Untangling the Interplay between Epidemic Spread and Transmission Network Dynamics.

    Directory of Open Access Journals (Sweden)

    Christel Kamp

    Full Text Available The epidemic spread of infectious diseases is ubiquitous and often has a considerable impact on public health and economic wealth. The large variability in the spatio-temporal patterns of epidemics prohibits simple interventions and requires a detailed analysis of each epidemic with respect to its infectious agent and the corresponding routes of transmission. To facilitate this analysis, we introduce a mathematical framework which links epidemic patterns to the topology and dynamics of the underlying transmission network. The evolution, both in disease prevalence and transmission network topology, is derived from a closed set of partial differential equations for infections without allowing for recovery. The predictions are in excellent agreement with complementarily conducted agent-based simulations. The capacity of this new method is demonstrated in several case studies on HIV epidemics in synthetic populations: it allows us to monitor the evolution of contact behavior among healthy and infected individuals and the contributions of different disease stages to the spreading of the epidemic. This gives both direction to and a test bed for targeted intervention strategies for epidemic control. In conclusion, this mathematical framework provides a capable toolbox for the analysis of epidemics from first principles. This allows for fast, in silico modeling--and manipulation--of epidemics and is especially powerful if complemented with adequate empirical data for parameterization.

  19. Phenotypic and Genotypic Comparison of Epidemic and Non-Epidemic Strains of Pseudomonas aeruginosa from Individuals with Cystic Fibrosis.

    Directory of Open Access Journals (Sweden)

    Jessica Duong

    Full Text Available Epidemic strains of Pseudomonas aeruginosa have been found worldwide among the cystic fibrosis (CF patient population. Using pulse-field gel electrophoresis, the Prairie Epidemic Strain (PES has recently been found in one-third of patients attending the Calgary Adult CF Clinic in Canada. Using multi-locus sequence typing, PES isolates from unrelated patients were found to consistently have ST192. Though most patients acquired PES prior to enrolling in the clinic, some patients were observed to experience strain replacement upon transitioning to the clinic whereby local non-epidemic P. aeruginosa isolates were displaced by PES. Here we genotypically and phenotypically compared PES to other P. aeruginosa epidemic strains (OES found around the world as well as local non-epidemic CF P. aeruginosa isolates in order to characterize PES. Since some epidemic strains are associated with worse clinical outcomes, we assessed the pathogenic potential of PES to determine if these isolates are virulent, shared properties with OES, and if its phenotypic properties may offer a competitive advantage in displacing local non-epidemic isolates during strain replacement. As such, we conducted a comparative analysis using fourteen phenotypic traits, including virulence factor production, biofilm formation, planktonic growth, mucoidy, and antibiotic susceptibility to characterize PES, OES, and local non-epidemic isolates. We observed that PES and OES could be differentiated from local non-epidemic isolates based on biofilm growth with PES isolates being more mucoid. Pairwise comparisons indicated that PES produced significantly higher levels of proteases and formed better biofilms than OES but were more susceptible to antibiotic treatment. Amongst five patients experiencing strain replacement, we found that super-infecting PES produced lower levels of proteases and elastases but were more resistant to antibiotics compared to the displaced non-epidemic isolates. This

  20. MycoCosm, an Integrated Fungal Genomics Resource

    Energy Technology Data Exchange (ETDEWEB)

    Shabalov, Igor; Grigoriev, Igor

    2012-03-16

    MycoCosm is a web-based interactive fungal genomics resource, which was first released in March 2010, in response to an urgent call from the fungal community for integration of all fungal genomes and analytical tools in one place (Pan-fungal data resources meeting, Feb 21-22, 2010, Alexandria, VA). MycoCosm integrates genomics data and analysis tools to navigate through over 100 fungal genomes sequenced at JGI and elsewhere. This resource allows users to explore fungal genomes in the context of both genome-centric analysis and comparative genomics, and promotes user community participation in data submission, annotation and analysis. MycoCosm has over 4500 unique visitors/month or 35000+ visitors/year as well as hundreds of registered users contributing their data and expertise to this resource. Its scalable architecture allows significant expansion of the data expected from JGI Fungal Genomics Program, its users, and integration with external resources used by fungal community.

  1. The opioid overdose epidemic: opportunities for pharmacists

    Directory of Open Access Journals (Sweden)

    Wu LT

    2017-07-01

    Full Text Available Li-Tzy Wu,1–4 Udi E Ghitza,5 Anne L Burns,6 Paolo Mannelli,1 1Department of Psychiatry and Behavioral Sciences, 2Department of Medicine, 3Duke Clinical Research Institute, Duke University School of Medicine, 4Center for Child and Family Policy, Sanford School of Public Policy, Duke University, Durham, NC, 5Center for Clinical Trials Network, National Institute on Drug Abuse, Bethesda, MD, 6American Pharmacists Association, Washington, DC, USA The USA is experiencing an opioid overdose epidemic. It has been driven largely by prescription opioids and intensified by a surge of illicit opioids (e.g., heroin and fentanyl.1,2 Drug-involved overdose, mainly opioids (e.g., prescription opioids and heroin, is a leading cause of accidental death in the USA. The opioid overdose epidemic has been escalating consistently for over a decade.2 Every day, an estimated 91 Americans die from opioid-related overdose.3 Opioid overdose appears to have disproportionally affected men, adults aged 25–64 years, and non-Hispanic whites.2

  2. Resource allocation for epidemic control in metapopulations.

    Science.gov (United States)

    Ndeffo Mbah, Martial L; Gilligan, Christopher A

    2011-01-01

    Deployment of limited resources is an issue of major importance for decision-making in crisis events. This is especially true for large-scale outbreaks of infectious diseases. Little is known when it comes to identifying the most efficient way of deploying scarce resources for control when disease outbreaks occur in different but interconnected regions. The policy maker is frequently faced with the challenge of optimizing efficiency (e.g. minimizing the burden of infection) while accounting for social equity (e.g. equal opportunity for infected individuals to access treatment). For a large range of diseases described by a simple SIRS model, we consider strategies that should be used to minimize the discounted number of infected individuals during the course of an epidemic. We show that when faced with the dilemma of choosing between socially equitable and purely efficient strategies, the choice of the control strategy should be informed by key measurable epidemiological factors such as the basic reproductive number and the efficiency of the treatment measure. Our model provides new insights for policy makers in the optimal deployment of limited resources for control in the event of epidemic outbreaks at the landscape scale.

  3. [The cholera epidemic in Latin America].

    Science.gov (United States)

    Olsvik, O

    1992-05-30

    An outbreak of cholera started in Peru in January 1991 and spread through most Latin American countries within a year. This was the first known epidemic of cholera in America for more than a century. In 1991, 321,334 persons were reported to have cholera in Peru, 119,063 were hospitalized, and 2,906 died. Other countries like Ecuador, Colombia, Guatemala, Brazil, Mexico, Bolivia, Chile, El Salvador, Venezuela and Honduras were also affected, but these countries combined accounted for only 20% of the cases registered in Peru. In April 1992, all Latin American countries except Uruguay, Paraguay and French Guyana have reported cholera. The mortality rate for the epidemic in Latin America was only 1%, mainly owing to good oral rehydration treatment provided by Local health services and the Pan American Health Organization. The causative organism was Vibrio cholerae, serogroup O1, serotype Inaba (and Ogawa) of the El Tor biotype. Genetic characterization shows this strain to be unique, and the designation is reserved for the Latin American strain, distinguishing it from the other El Tor isolates from the 7th pandemic.

  4. Devastating epidemics in recent ages Greek populations.

    Science.gov (United States)

    Kotsiou, Antonia; Michalaki, Vasiliki; Anagnostopoulou, Helen N

    2017-12-01

    In the recent Greek ages the most devastating epidemics were plague, smallpox, leprosy and cholera. In 1816 plague struck the Ionian and Aegean Islands, mainland Greece, Constantinople and Smyrna. The Venetians ruling the Ionian Islands effectively combated plague in contrast to the Ottomans ruling all other regions. In 1922, plague appeared in Patras refugees who were expelled by the Turks from Smyrna and Asia Minor. Inoculation against smallpox was first performed in Thessaly by the Greek women, and the Greek doctors Emmanouel Timonis (1713, Oxford) and Jakovos Pylarinos (1715, Venice) made relevant scientific publications. The first leper colony opened in Chios Island. In Crete, Spinalonga was transformed into a leper island, which following the Independence War against Turkish occupation and the unification of Crete with Greece in 1913, was classified as an International Leper Hospital. Cholera struck Greece in 1853-1854 brought by the French troops during the Crimean War, and again during the Balkan Wars (1912-13) when the Bulgarian troops brought cholera to northern Greece. Due to successive wars, medical assistance was not always available, so desperate people turned many times to religion through processions in honor of local saints, for their salvation in epidemics.

  5. Resource allocation for epidemic control in metapopulations.

    Directory of Open Access Journals (Sweden)

    Martial L Ndeffo Mbah

    Full Text Available Deployment of limited resources is an issue of major importance for decision-making in crisis events. This is especially true for large-scale outbreaks of infectious diseases. Little is known when it comes to identifying the most efficient way of deploying scarce resources for control when disease outbreaks occur in different but interconnected regions. The policy maker is frequently faced with the challenge of optimizing efficiency (e.g. minimizing the burden of infection while accounting for social equity (e.g. equal opportunity for infected individuals to access treatment. For a large range of diseases described by a simple SIRS model, we consider strategies that should be used to minimize the discounted number of infected individuals during the course of an epidemic. We show that when faced with the dilemma of choosing between socially equitable and purely efficient strategies, the choice of the control strategy should be informed by key measurable epidemiological factors such as the basic reproductive number and the efficiency of the treatment measure. Our model provides new insights for policy makers in the optimal deployment of limited resources for control in the event of epidemic outbreaks at the landscape scale.

  6. America's Opioid Epidemic: Supply and Demand Considerations.

    Science.gov (United States)

    Clark, David J; Schumacher, Mark A

    2017-11-01

    America is in the midst of an opioid epidemic characterized by aggressive prescribing practices, highly prevalent opioid misuse, and rising rates of prescription and illicit opioid overdose-related deaths. Medical and lay public sentiment have become more cautious with respect to prescription opioid use in the past few years, but a comprehensive strategy to reduce our reliance on prescription opioids is lacking. Addressing this epidemic through reductions in unnecessary access to these drugs while implementing measures to reduce demand will be important components of any comprehensive solution. Key supply-side measures include avoiding overprescribing, reducing diversion, and discouraging misuse through changes in drug formulations. Important demand-side measures center around educating patients and clinicians regarding the pitfalls of opioid overuse and methods to avoid unnecessary exposure to these drugs. Anesthesiologists, by virtue of their expertise in the use of these drugs and their position in guiding opioid use around the time of surgery, have important roles to play in reducing patient exposure to opioids and providing education about appropriate use. Aside from the many immediate steps that can be taken, clinical and basic research directed at understanding the interaction between pain and opioid misuse is critical to identifying the optimal use of these powerful pain relievers in clinical practice.

  7. Epidemic contact tracing via communication traces.

    Directory of Open Access Journals (Sweden)

    Katayoun Farrahi

    Full Text Available Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  8. Modelling the dynamics of nonendemic epidemics

    International Nuclear Information System (INIS)

    Ramani, A.; Grammaticos, B.; Satsuma, J.

    2009-01-01

    We present two models for an epidemic where the individuals are infective over a fixed period of time and which never becomes endemic i.e., no infective individuals remain after the epidemic has run its course. The first model is based on a delay-difference scheme. We show that, as a function of the delay (which corresponds to the period of infectiveness) the percentage of non-infected population varies over a wide range. We present also a variant of our model where the recovery rate follows a Poisson law and obtain a discrete version of the SIR model. We estimate the percentage of non-infected population in the two models, show that they lead to almost the same values and present an explanation of this fact. The second model is based on the assumption that the infection is spread by carriers. Under the hypothesis that the carriers are relatively long-lived, and that the number of the infected ones is a relatively small fraction of the total population of potential carriers, we show that the model reduces to the same version of the discrete SIR obtained by our first model.

  9. Modelling dengue epidemic spreading with human mobility

    Science.gov (United States)

    Barmak, D. H.; Dorso, C. O.; Otero, M.

    2016-04-01

    We explored the effect of human mobility on the spatio-temporal dynamics of Dengue with a stochastic model that takes into account the epidemiological dynamics of the infected mosquitoes and humans, with different mobility patterns of the human population. We observed that human mobility strongly affects the spread of infection by increasing the final size and by changing the morphology of the epidemic outbreaks. When the spreading of the disease is driven only by mosquito dispersal (flight), a main central focus expands diffusively. On the contrary, when human mobility is taken into account, multiple foci appear throughout the evolution of the outbreaks. These secondary foci generated throughout the outbreaks could be of little importance according to their mass or size compared with the largest main focus. However, the coalescence of these foci with the main one generates an effect, through which the latter develops a size greater than the one obtained in the case driven only by mosquito dispersal. This increase in growth rate due to human mobility and the coalescence of the foci are particularly relevant in temperate cities such as the city of Buenos Aires, since they give more possibilities to the outbreak to grow before the arrival of the low-temperature season. The findings of this work indicate that human mobility could be the main driving force in the dynamics of vector epidemics.

  10. Epidemic contact tracing via communication traces.

    Science.gov (United States)

    Farrahi, Katayoun; Emonet, Rémi; Cebrian, Manuel

    2014-01-01

    Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  11. Colliding Epidemics and the Rise of Cryptococcosis

    Directory of Open Access Journals (Sweden)

    Christina C. Chang

    2015-12-01

    Full Text Available Discovered more than 100 years ago as a human pathogen, the Cryptococcus neoformans–Cryptococcus gattii (C. neoformans–C. gattii complex has seen a large global resurgence in its association with clinical disease in the last 30 years. First isolated in fermenting peach juice, and identified as a human pathogen in 1894 in a patient with bone lesions, this environmental pathogen has now found niches in soil, trees, birds, and domestic pets. Cryptococcosis is well recognized as an opportunistic infection and was first noted to be associated with reticuloendothelial cancers in the 1950s. Since then, advances in transplant immunology, medical science and surgical techniques have led to increasing numbers of solid organ transplantations (SOT and hematological stem cell transplantations being performed, and the use of biological immunotherapeutics in increasingly high-risk and older individuals, have contributed to the further rise in cryptococcosis. Globally, however, the major driver for revivification of cryptococcosis is undoubtedly the HIV epidemic, particularly in Sub-Saharan Africa where access to care and antiretroviral therapy remains limited and advanced immunodeficiency, poverty and malnutrition remains the norm. As a zoonotic disease, environmental outbreaks of both human and animal cryptococcosis have been reported, possibly driven by climate change. This is best exemplified by the resurgence of C. gattii infection in Vancouver Island, Canada, and the Pacific Northwest of the United States since 1999. Here we describe how the colliding epidemics of HIV, transplantation and immunologics, climate change and migration have contributed to the rise of cryptococcosis.

  12. Analysis of Impact of Geographical Environment and Socio-economic Factors on the Spatial Distribution of Kaohsiung Dengue Fever Epidemic

    Science.gov (United States)

    Hsu, Wei-Yin; Wen, Tzai-Hung; Yu, Hwa-Lung

    2013-04-01

    Taiwan is located in subtropical and tropical regions with high temperature and high humidity in the summer. This kind of climatic condition is the hotbed for the propagation and spread of the dengue vector mosquito. Kaohsiung City has been the worst dengue fever epidemic city in Taiwan. During the study period, from January 1998 to December 2011, Taiwan CDC recorded 7071 locally dengue epidemic cases in Kaohsiung City, and the number of imported case is 118. Our research uses Quantile Regression, a spatial infection disease distribution, to analyze the correlation between dengue epidemic and geographic environmental factors and human society factors in Kaohsiung. According to our experiment statistics, agriculture and natural forest have a positive relation to dengue fever(5.5~34.39 and 3.91~15.52). The epidemic will rise when the ratio for agriculture and natural forest increases. Residential ratio has a negative relation for quantile 0.1 to 0.4(-0.005~-0.78), and a positive relation for quantile 0.5 to0.9(0.01~18.0) . The mean income is also a significant factor in social economy field, and it has a negative relation to dengue fever(-0.01~-0.04). Conclusion from our research is that the main factor affecting the degree of dengue fever in predilection area is the residential proportion and the ratio of agriculture and natural forest plays an important role affecting the degree of dengue fever in non predilection area. Moreover, the serious epidemic area located by regression model is the same as the actual condition in Kaohsiung. This model can be used to predict the serious epidemic area of dengue fever and provide some references for the Health Agencies

  13. Streptomycetes and micromycetes as perspective antagonists of fungal phytopathogens.

    Science.gov (United States)

    Postolaky, O; Syrbu, T; Poiras, N; Baltsat, K; Maslobrod, S; Boortseva, S

    2012-01-01

    Among natural factors that permanently influence on the plants, the soil microorganisms play a special role for the growing of plants as habitants of their rhizosphere. Mainly they are the representatives of actinomycetes genus Streptomyces and fungal genus Penicillium and their metabolic products stimulate plant growth and inhibit the growth of pathogenic fungi and bacteria. The aim of our study was to determine the antagonism of actinomycetes and micromycetes isolated from soils of R. Moldova against the fungal pathogens of agricultural plants. The strains were isolated from 5 types of chernozem (black soil) from central zone of R. Moldova, with different concentration of humus. Most of micromycetes and streptomycetes were isolated from soil sample 1 (monoculture of maize) and soil sample 2 (Poltava road border) with similar humus content (2.4-2.6%). The antifungal activity of micromycetes strains was occurring mostly against Fusarium solani and Thelaviopsis basicola, at streptomycetes against Alternaria alternata and Botrytis cinerea. It was revealed the strains completely inhibit the growth of Alt. alternata (streptomycetes strains 23, 33, 37), B. cinerea (Streptomyces sp. 17), and F. solani (Penicillium sp. 104). Our results allow to consider the actinomycetes Streptomyces sp.9, Streptomyces sp. 12, Streptomyces sp. 17, Streptomyces sp. 37 Streptomyces sp. 66 and micromycetes Penicillium sp. 5, Penicillium sp. 65, Penicillium sp. 104 isolated from soils of R. Moldova, as prospective strains-antagonists against the phytopathogenic fungus, the causative agents of agricultural plants deseasis.

  14. Fungal biocatalysts in the biofiltration of VOC-polluted air.

    Science.gov (United States)

    Kennes, Christian; Veiga, María C

    2004-09-30

    Gas-phase biofilters used for the treatment of waste gases were originally packed with compost or other natural filter beds containing indigenous microorganisms. Over the past decade much effort has been made to develop new carrier materials, more performant biocatalysts and new types of bioreactors. Elimination capacities reached nowadays are 5 to 10 times higher than those originally reported with conventional compost biofilters. With the recently developed inert filter beds, inoculation is a prerequisite for successful start-up and operation. Either non-defined mixed cultures or pure bacterial cultures have originally been used. The search for efficient fungal biocatalysts started only a few years ago, mainly for the biofiltration of waste gases containing hydrophobic compounds, such as styrene, alpha-pinene, benzene, or alkylbenzenes. In this review, recently isolated new fungal strains able to degrade alkylbenzenes and other related volatile organic pollutants are described, as well as their major characteristics and their use as biocatalysts in gas-phase biofilters for air pollution control. In biofiltration, the most extensively studied organism belongs to the genus Exophiala, although strains of Scedosporium, Paecilomyces, Cladosporium, Cladophialophora, and white-rot fungi are all potential candidates for use in biofilters. Encouraging results were obtained in most of the cases in which some of those organisms were present in gas-phase biofilters. They allow reaching high elimination capacities and are resistant to low pH values and to reduce moisture content.

  15. Engineering and Applications of fungal laccases for organic synthesis

    Directory of Open Access Journals (Sweden)

    Ballesteros Antonio

    2008-11-01

    Full Text Available Abstract Laccases are multi-copper containing oxidases (EC 1.10.3.2, widely distributed in fungi, higher plants and bacteria. Laccase catalyses the oxidation of phenols, polyphenols and anilines by one-electron abstraction, with the concomitant reduction of oxygen to water in a four-electron transfer process. In the presence of small redox mediators, laccase offers a broader repertory of oxidations including non-phenolic substrates. Hence, fungal laccases are considered as ideal green catalysts of great biotechnological impact due to their few requirements (they only require air, and they produce water as the only by-product and their broad substrate specificity, including direct bioelectrocatalysis. Thus, laccases and/or laccase-mediator systems find potential applications in bioremediation, paper pulp bleaching, finishing of textiles, bio-fuel cells and more. Significantly, laccases can be used in organic synthesis, as they can perform exquisite transformations ranging from the oxidation of functional groups to the heteromolecular coupling for production of new antibiotics derivatives, or the catalysis of key steps in the synthesis of complex natural products. In this review, the application of fungal laccases and their engineering by rational design and directed evolution for organic synthesis purposes are discussed.

  16. Zika virus epidemic: the newest international emergency

    Directory of Open Access Journals (Sweden)

    Ruth Minamisava

    2016-03-01

    production, accurate diagnosis and treatment, training for caring for neurological syndromes and congenital malformations. (iii          Measures for travelers: counseling, disinfestation of aircrafts and airports. (iv          Sharing of information. Some inquiries have been made about the magnitude of this epidemic and its association with microcephaly and neurological disorders(4-5. It is reasonable to consider that there is an underreporting of microcephaly in the records of the Live Births Information System in Brazil. It is also to be expected that, after the national alert, the number of suspected cases would rise. When there is an increase or the implementation of surveillance, this always results in higher sensitivity of detection of suspected/reported cases with an increase in false positives. For these reasons, it is possible to say that part of the increase in reported cases of microcephaly may be attributable to the current intense surveillance. What is inconceivable, however, is that the prevalence of microcephaly in northeastern Brazil is 10 to 20 times higher than in other countries(6. At present, there are hypotheses that the Zika virus may have an etiologic and/or pathophysiological role for these events, which is usually rare. What seems indisputable is the gravity of the situation. Health managers cannot wait for high-level scientific evidence. Care and prudence when assessing is advisable, and the same goes for avoiding premature conclusions. However, given the potential threat, we have a duty to at least protect pregnant women and their fetuses. The current situation poses many challenges that we need to face and it seems logical that Brazil take the lead in beginning the actions. We recognize in our history both the success in the fight against yellow fever early in the last century and also our recent inefficiency in the fight against the Aedes aegypti mosquito to control dengue and chikungunya. It is necessary to create, renew, and

  17. Packaging conditions hindering fungal growth on cheese

    DEFF Research Database (Denmark)

    Nielsen, Per Væggemose; Haasum, Iben

    1997-01-01

    Fungal contamination is one of the most important quality deteriorating factors on cheese. During the last 5 years we have studied in detail the underlying factors controlling these unwanted processes in a collaborative project financed by the Danish Dairy Board and the Ministry of Agriculture...

  18. Fungal peroxidases : molecular aspects and applications

    NARCIS (Netherlands)

    Conesa, A.; Punt, P.J.; Hondel, C.A.M.J.J.

    2002-01-01

    Peroxidases are oxidoreductases that utilize hydrogen peroxide to catalyze oxidative reactions. A large number of peroxidases have been identified in fungal species and are being characterized at the molecular level. In this manuscript we review the current knowledge on the molecular aspects of this

  19. Fungal Planet description sheets: 400-468

    Czech Academy of Sciences Publication Activity Database

    Crous, P.W.; Wingfield, M. J.; Richardson, D. M.; Le Roux, J. J.; Strasberg, D.; Edwards, J.; Roets, F.; Hubka, V.; Taylor, P.W.J.; Heykoop, M.; Martín, M.P.; Moreno, G.; Sutton, D.A.; Wiederhold, N.P.; Barnes, C.W.; Carlavilla, J.R.; Gené, J.; Giraldo, A.; Guarnaccia, V.; Guarro, J.; Hernández-Restrepo, M.; Kolařík, Miroslav; Manjón, J.L.; Pascoe, I.G.; Popov, E.S.; Sandoval-Denis, M.; Woudenberg, J.H.C.; Acharya, K.; Alexandrova, A.V.; Alvarado, P.; Barbosa, R.N.; Baseia, I.G.; Blanchette, R.A.; Boekhout, T.; Burgess, T.I.; Cano-Lira, J.F.; Čmoková, A.; Dimitrov, R.A.; Dyakov, M.Yu.; Dueñas, M.; Dutta, A.K.; Esteve- Raventós, F.; Fedosova, A.G.; Fournier, J.; Gamboa, P.; Gouliamova, D.E.; Grebenc, T.; Groenewald, M.; Hanse, B.; Hardy, G.E.St.J.; Held, B.W.; Jurjević, Ž.; Kaewgrajang, T.; Latha, K.P.D.; Lombard, L.; Luangsa-Ard, J.J.; Lysková, P.; Mallátová, N.; Manimohan, P.; Miller, A.N.; Mirabolfathy, M.; Morozova, O.V.; Obodai, M.; Oliveira, N.T.; Otto, E.C.; Paloi, S.; Peterson, S.W.; Phosri, C.; Roux, J.; Salazar, W.A.; Sánchez, A.; Sarria, G.A.; Shin, H.-D.; Silva, B.D.B.; Silva, G.A.; Smith, M.Th.; Souza-Motta, C.M.; Stchigel, A.M.; Stoilova-Disheva, M.M.; Sulzbacher, M.A.; Telleria, M.T.; Toapanta, C.; Traba, J.M.; Valenzuela-Lopez, N.; Watling, R.; Groenewald, J.Z.

    2016-01-01

    Roč. 36, July (2016), s. 316-458 ISSN 0031-5850 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : ITS DNA barcodes * LSU * fungal species Subject RIV: EE - Microbiology, Virology Impact factor: 7.511, year: 2016

  20. A biotechnology perspective of fungal proteases

    Directory of Open Access Journals (Sweden)

    Paula Monteiro de Souza

    2015-06-01

    Full Text Available Proteases hydrolyze the peptide bonds of proteins into peptides and amino acids, being found in all living organisms, and are essential for cell growth and differentiation. Proteolytic enzymes have potential application in a wide number of industrial processes such as food, laundry detergent and pharmaceutical. Proteases from microbial sources have dominated applications in industrial sectors. Fungal proteases are used for hydrolyzing protein and other components of soy beans and wheat in soy sauce production. Proteases can be produced in large quantities in a short time by established methods of fermentation. The parameters such as variation in C/N ratio, presence of some sugars, besides several other physical factors are important in the development of fermentation process. Proteases of fungal origin can be produced cost effectively, have an advantage faster production, the ease with which the enzymes can be modified and mycelium can be easily removed by filtration. The production of proteases has been carried out using submerged fermentation, but conditions in solid state fermentation lead to several potential advantages for the production of fungal enzymes. This review focuses on the production of fungal proteases, their distribution, structural-functional aspects, physical and chemical parameters, and the use of these enzymes in industrial applications.

  1. October 2012 Multistate Fungal Meningitis Outbreak

    Centers for Disease Control (CDC) Podcasts

    2012-10-17

    This podcast gives an overview of the October 2012 multistate fungal meningitis outbreak, including symptoms to watch for and a website for up-to-date information.  Created: 10/17/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/17/2012.

  2. Fungal biology and agriculture: revisiting the field

    Science.gov (United States)

    Yarden, O.; Ebbole, D.J.; Freeman, S.; Rodriguez, R.J.; Dickman, M. B.

    2003-01-01

    Plant pathology has made significant progress over the years, a process that involved overcoming a variety of conceptual and technological hurdles. Descriptive mycology and the advent of chemical plant-disease management have been followed by biochemical and physiological studies of fungi and their hosts. The later establishment of biochemical genetics along with the introduction of DNA-mediated transformation have set the stage for dissection of gene function and advances in our understanding of fungal cell biology and plant-fungus interactions. Currently, with the advent of high-throughput technologies, we have the capacity to acquire vast data sets that have direct relevance to the numerous subdisciplines within fungal biology and pathology. These data provide unique opportunities for basic research and for engineering solutions to important agricultural problems. However, we also are faced with the challenge of data organization and mining to analyze the relationships between fungal and plant genomes and to elucidate the physiological function of pertinent DNA sequences. We present our perspective of fungal biology and agriculture, including administrative and political challenges to plant protection research.

  3. Fungal Systematics and Evolution: FUSE 1

    NARCIS (Netherlands)

    Crous, Pedro W; Schumacher, René K; Wingfield, Michael J; Lombard, Lorenzo; Giraldo, Alejandra; Christensen, Martha; Gardiennet, Alain; Nakashima, Chiharu; Pereira, Olinto L; Smith, Alexander J; Groenewald, Johannes Z

    2015-01-01

    Fungal Systematics and Evolution (FUSE) is introduced as a new series to expedite the publication of issues relating to the epitypification of formerly described species, report new sexual-asexual connections, the merging of sexual and asexual gen¬era following the end of dual nomenclature, and to

  4. Fungal Planet description sheets: 371-399

    Czech Academy of Sciences Publication Activity Database

    Crous, P. W.; Wingfield, M. J.; Le Roux, J. J.; Richardson, D. M.; Strasberg, D.; Shivas, R.G.; Alvarado, P.; Edwards, J.; Moreno, G.; Sharma, R.; Sonawane, M.S.; Tan, Y.P.; Altés, A.; Barasubiye, T.; Barnes, C.W.; Blanchette, R.A.; Boertmann, D.; Bogo, A.; Carlavilla, J.R.; Cheewangkoon, R.; Daniel, R.; de Beer, Z.W.; de Yáňez-Morales, J.; Duong, T.A.; Fernández-Vicente, J.; Geering, A.D.W.; Guest, D.I.; Held, B.W.; Heykoop, M.; Hubka, V.; Ismail, A.M.; Kajale, S.C.; Khemmuk, W.; Kolařík, Miroslav; Kurli, R.; Lebeuf, R.; Levesque, C.A.; Lombard, L.; Magista, D.; Manjón, J.L.; Marincowitz, S.; Mohedano, J.M.; Nováková, Alena; Oberlies, N.H.; Otto, E.C.; Paguigan, N.D.; Pascoe, I.G.; Peréz-Butrón, J.L.; Perrone, G.; Rahi, P.; Raja, H.A.; Rintoul, T.; Sanhueza, R.M.V.; Scarlett, K.; Shouche, Y.S.; Shuttleworth, L.A.; Taylor, P.W.J.; Thorn, R.G.; Vawdrey, L.L.; Solano-Vidal, R.; Voitk, A.; Wong, P.T.W.; Wood, A.R.; Zamora, J.C.; Groenewald, J.Z.

    2015-01-01

    Roč. 35, December (2015), s. 264-327 ISSN 0031-5850 R&D Projects: GA ČR(CZ) GAP506/12/1064 Institutional support: RVO:61388971 Keywords : ITS DNA barcodes * LSU * novel fungal species Subject RIV: EE - Microbiology, Virology Impact factor: 5.725, year: 2015

  5. Fungal ABC Transporter Deletion and Localization Analysis

    NARCIS (Netherlands)

    Kovalchuk, A.; Weber, S.S.; Nijland, J.G.; Bovenberg, R.A.L.; Driessen, A.J.M.

    2012-01-01

    Fungal cells are highly complex as their metabolism is compartmentalized harboring various types of subcellular organelles that are bordered by one or more membranes. Knowledge about the intracellular localization of transporter proteins is often required for the understanding of their biological

  6. CT scan findings of fungal pneumonia

    International Nuclear Information System (INIS)

    Heckmann, M.; Uder, M.; Bautz, W.; Heinrich, M.

    2008-01-01

    The importance of fungal infection of the lung in immunocompromised patients has increased substantially during the last decades. Numerically the most patients are those with neutropenia, e.g. patients with malignancies or solid organ and stem cell transplantation, chemotherapy, corticosteroid use and HIV infection. Although fungal infections can occur in immunocompetent patients, their frequency in this population is rare. The clinical symptoms such as fever accompanied with non-productive cough are unspecific. In some patients progression to hypoxemia and dyspnea may occur rapidly. In spite of improved antifungal therapy morbidity and mortality of these infections are still high. Therefore an early and non-invasive diagnosis is very important. That is why CT and even better High-Resolution-CT (HR-CT) is a very important modality in examining immunocompromised patients with a probability of fungal infection. CT is everywhere available and, as a non-invasive method, able to give the relevant diagnose efficiently. This paper should give an overview about the radiologic findings and possible differential diagnosis of diverse pulmonary fungal infections in CT. Pneumonias caused by Aspergillus, Cryptococcus, Candida, Histoplasma, Mucor and Geotrichum capitatum are illustrated. (orig.)

  7. The Amstersam declaration on fungal nomenclature

    DEFF Research Database (Denmark)

    Hawksworth, David L.; Crous, Pedro W.; Redhead, Scott A.

    2011-01-01

    The Amsterdam Declaration on Fungal Nomenclature was agreed at an international symposium convened in Amsterdam on 19–20 April 2011 under the auspices of the International Commission on the Taxonomy of Fungi (ICTF). The purpose of the symposium was to address the issue of whether or how the current...

  8. Fungal peritonitis in children on peritoneal dialysis.

    NARCIS (Netherlands)

    Raaijmakers, R.; Schroder, C.; Monnens, L.A.H.; Cornelissen, E.A.M.; Warris, A.

    2007-01-01

    Fungal peritonitis is a rare but serious complication in children on peritoneal dialysis (PD). In this study, risk factors were evaluated, and therapeutic measures were reviewed. A retrospective, multi-centre study was performed in 159 Dutch paediatric PD patients, between 1980 and 2005 (3,573

  9. UV-guided isolation of fungal metabolites by HSCCC

    DEFF Research Database (Denmark)

    Dalsgaard, P.W.; Nielsen, K.F.; Larsen, Thomas Ostenfeld

    2005-01-01

    Analytical standardised reversed phase liquid chromatography (RPLC) data can be helpful in finding a suitable solvent combination for isolation of fungal metabolites by high-speed counter current chromatography. Analysis of the distribution coefficient (K-D) of fungal metabolites in a series...... peptides from a crude fungal extract....

  10. Burden of Serious Fungal Infections in Jordan

    Directory of Open Access Journals (Sweden)

    Jamal Wadi

    2018-01-01

    Full Text Available Objective: To estimate the burden of fungal infections in Jordan for the first time. Material and Methods: Population data was from UN 2011 statistics and TB cases from WHO in 2012. Fewer than 100 patients with HIV were recorded in Jordan in 2013. Approximately 100 renal transplants and eight liver transplants are performed annually. There were 12,233 major surgical procedures in Jordan in 2013, of which 5.3% were major abdominal surgeries; candidemia was estimated in 5% of the population based on other countries, with 33% occurring in the ICU. Candida peritonitis/intra-abdominal candidiasis was estimated to affect 50% of the number of ICU candidemia cases. No adult asthma rates have been recorded for Jordan, so the rate from the Holy Land (8.54% clinical asthma from To et al. has been used. There are an estimated 49,607 chronic obstructive pulmonary disease (COPD patients in Jordan, with 64% symptomatic, 25% Gold stage 3% or 4%, and 7% (3472 are assumed to be admitted to hospital each year. No cystic fibrosis cases have been recorded. Literature searches on fungal infections revealed few data and no prevalence data on fungal keratitis or tinea capitis, even though tinea capitis comprised 34% of patients with dermatophytoses in Jordan. Results: Jordan has 6.3 million inhabitants (65% adults, 6% are >60 years old. The current burden of serious fungal infections in Jordan was estimated to affect ~119,000 patients (1.9%, not including any cutaneous fungal infections. Candidemia was estimated at 316 cases and invasive aspergillosis in leukemia, transplant, and COPD patients at 84 cases. Chronic pulmonary aspergillosis prevalence was estimated to affect 36 post-TB patients, and 175 in total. Allergic bronchopulmonary aspergillosis (ABPA and severe asthma with fungal sensitization (SAFS prevalence in adults with asthma were estimated at 8900 and 11,748 patients. Recurrent vulvovaginal candidiasis was estimated to affect 97,804 patients, using a 6

  11. Production of fungal chitosan from date wastes and its application as a biopreservative for minced meat.

    Science.gov (United States)

    Tayel, Ahmed A; Ibrahim, Sami I A; Al-Saman, Mahmoud A; Moussa, Shaaban H

    2014-08-01

    Raw and processed meat contaminated with pathogenic microorganisms is a continuing worldwide problem facing health and industry overseers. Fungal chitosan was extracted, purified and characterized from Aspergillus brasiliensis (niger) ATCC 16404 grown in date syrup (dips) and applied as a potential meat biopreservative. The main features of produced chitosan were a deacetylation degree of 81.3%, a molecular weight of 31,000Da, 96% solubility in 1% acetic acid solution and a harmonized IR-spectrum to standard commercial chitosan. The application of fungal chitosan, as a natural and safe biopreservative for minced meat, was conducted in comparison with potassium sorbate, as a commercial meat preservative. Treated meat samples with 0.02% chitosan was the least trials in microbial contents, i.e. total count, coliforms, β-glucuronidase-positive Escherichia coli, Enterobacteriaceae, yeasts and molds, Staphylococcus aureus and coagulase positive staphylococci. The antimicrobial activity of fungal chitosan was considerably greater than that of potassium sorbate or their combination at 0.01% from each. Sensory characteristics, e.g. color, odor and texture, of treated meat with chitosan, were higher than those of control and potassium sorbate treated samples. Fungal chitosan, however, could be recommended as a powerful, natural and eco-friendly alternative for meat preservation and overall quality maintenance. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.

    Science.gov (United States)

    Mykrä, Heikki; Sarremejane, Romain; Laamanen, Tiina; Karjalainen, Satu Maaria; Markkola, Annamari; Lehtinen, Sirkku; Lehosmaa, Kaisa; Muotka, Timo

    2018-04-16

    We examined how short-term (19 days) nutrient enrichment influences stream fungal and diatom communities, and rates of leaf decomposition and algal biomass accrual. We conducted a field experiment using slow-releasing nutrient pellets to increase nitrate (NO 3 -N) and phosphate (PO 4 -P) concentrations in a riffle section of six naturally acidic (naturally low pH due to catchment geology) and six circumneutral streams. Nutrient enrichment increased microbial decomposition rate on average by 14%, but the effect was significant only in naturally acidic streams. Nutrient enrichment also decreased richness and increased compositional variability of fungal communities in naturally acidic streams. Algal biomass increased in both stream types, but algal growth was overall very low. Diatom richness increased in response to nutrient addition by, but only in circumneutral streams. Our results suggest that primary producers and decomposers are differentially affected by nutrient enrichment and that their responses to excess nutrients are context dependent, with a potentially stronger response of detrital processes and fungal communities in naturally acidic streams than in less selective environments.

  13. Presentation and management of allergic fungal sinusitis

    International Nuclear Information System (INIS)

    Thahim, K.; Jawaid, M.A.; Marfani, S.

    2007-01-01

    To assess the presentation of allergic fungal sinusitis and describe the line of management in our setup. Culture and sensitivity / fungal stain proven 20 cases of allergic fungal sinusitis were selected for the study, irrespective of age and gender. Data including age, gender, socioeconomic status, signs, symptoms, laboratory findings (especially Immunoglobulin E and eosinophil count) and imaging studies (Computed Tomography and /or Magnetic Resonance Imaging) were noted for the study. Pre and postoperative medical treatment, surgery performed, follow-up; residual/recurrence disease and revised surgery performed were also recorded. In this series, allergic fungal sinusitis was a disease of younger age group with an average age of 20.75 years with male dominance (70%). Poor socioeconomic status (80%), allergic rhinitis (100%) and nasal polyposis (100%) were important associated factors. Nasal obstruction (100%), nasal discharge (90%), postnasal drip (90%) and unilateral nasal and paranasal sinuses involvement (60%) were the commonest presenting features. Aspergillus (60%) was the most common etiological agent. In all cases (100%), increased eosinophil count and IgE levels were present. Orbital (20%) and intracranial (10%) involvement were also seen. Surgical management was preferred in all cases. Functional endoscopic sinus surgery in 90% cases and lateral rhinotomy in 10% cases were performed. Recurrence / residual disease was seen in 20% cases. In this series, allergic fungal sinusitis was seen in immunocompetent, young males, belonging to poor socioeconomic status, suffering from allergic rhinitis and nasal polyposis, presenting with nasal obstruction, nasal discharge and postnasal drip. Functional endoscopic sinus surgery was the most important problem solving procedure while lateral rhinotomy was reserved for extensive disease. (author)

  14. Fungal endophytes which invade insect galls: insect pathogens, benign saprophytes, or fungal inquilines?

    Science.gov (United States)

    Wilson, Dennis

    1995-08-01

    Fungi are frequently found within insect galls. However, the origin of these fungi, whether they are acting as pathogens, saprophytes invading already dead galls, or fungal inquilines which invade the gall but kill the gall maker by indirect means, is rarely investigated. A pathogenic role for these fungi is usually inferred but never tested. I chose the following leaf-galling-insect/host-plant pairs (1) a cynipid which forms two-chambered galls on the veins of Oregon white oak, (2) a cynipid which forms single-chambered galls on California coast live oak, and (3) an aphid which forms galls on narrowleaf cottonwood leaves. All pairs were reported to have fungi associated with dead insects inside the gall. These fungi were cultured and identified. For the two cynipids, all fungi found inside the galls were also present in the leaves as fungal endophytes. The cottonwood leaves examined did not harbor fungal endophytes. For the cynipid on Oregon white oak, the fungal endophyte grows from the leaf into the gall and infects all gall tissue but does not directly kill the gall maker. The insect dies as a result of the gall tissue dying from fungal infection. Therefore, the fungus acts as an inquiline. Approximately 12.5% of these galls die as a result of invasion by the fungal endophyte.

  15. The origin and emergence of an HIV-1 epidemic:

    DEFF Research Database (Denmark)

    Bruhn, Christian Anders Wathne; Audelin, Anne M.; Helleberg, Marie

    2014-01-01

    To describe, at patient-level detail, the determining events and factors involved in the development of a country's HIV-1 epidemic.......To describe, at patient-level detail, the determining events and factors involved in the development of a country's HIV-1 epidemic....

  16. Stochastic analysis of epidemics on adaptive time varying networks

    Science.gov (United States)

    Kotnis, Bhushan; Kuri, Joy

    2013-06-01

    Many studies investigating the effect of human social connectivity structures (networks) and human behavioral adaptations on the spread of infectious diseases have assumed either a static connectivity structure or a network which adapts itself in response to the epidemic (adaptive networks). However, human social connections are inherently dynamic or time varying. Furthermore, the spread of many infectious diseases occur on a time scale comparable to the time scale of the evolving network structure. Here we aim to quantify the effect of human behavioral adaptations on the spread of asymptomatic infectious diseases on time varying networks. We perform a full stochastic analysis using a continuous time Markov chain approach for calculating the outbreak probability, mean epidemic duration, epidemic reemergence probability, etc. Additionally, we use mean-field theory for calculating epidemic thresholds. Theoretical predictions are verified using extensive simulations. Our studies have uncovered the existence of an “adaptive threshold,” i.e., when the ratio of susceptibility (or infectivity) rate to recovery rate is below the threshold value, adaptive behavior can prevent the epidemic. However, if it is above the threshold, no amount of behavioral adaptations can prevent the epidemic. Our analyses suggest that the interaction patterns of the infected population play a major role in sustaining the epidemic. Our results have implications on epidemic containment policies, as awareness campaigns and human behavioral responses can be effective only if the interaction levels of the infected populace are kept in check.

  17. The cholera epidemic in South Africa, 1980 - 1987 Epidemiological ...

    African Journals Online (AJOL)

    During the cholera epidemic in South Africa, 1980-1987, 25251 cases of cholera were bacteriologically proven. The case-fatality rate was 1,4%. Outbreaks occurred in the summer rainfall season. Age-specific aUack rates followed the pattern typically found during the 'epidemic phase' of the disease in most years. The vast ...

  18. [The cholera epidemic of 1833 and mortality in Mexico City].

    Science.gov (United States)

    Velasco, M D

    1992-01-01

    The author examines the impact of the 1833 cholera epidemic in Mexico City, Mexico, on social, economic, and political aspects of life in that city. She finds that some five percent of the population died during the epidemic, and enumerates them by age and sex.

  19. Unsynchronized influenza epidemics in two neighboring subtropical cities

    Directory of Open Access Journals (Sweden)

    Xiujuan Tang

    2018-04-01

    Full Text Available Objective: The aim of this study was to examine the synchrony of influenza epidemics between Hong Kong and Shenzhen, two neighboring subtropical cities in South China. Methods: Laboratory-confirmed influenza data for the period January 2006 to December 2016 were obtained from the Shenzhen Center for Disease Control and Prevention and the Department of Health in Hong Kong. The population data were retrieved from the 2011 population censuses. The weekly rates of laboratory-confirmed influenza cases were compared between Shenzhen and Hong Kong. Results: Unsynchronized influenza epidemics between Hong Kong and Shenzhen were frequently observed during the study period. Influenza A/H1N1 caused a more severe pandemic in Hong Kong in 2009, but the subsequent seasonal epidemics showed similar magnitudes in both cities. Two influenza A/H3N2 dominant epidemic waves were seen in Hong Kong in 2015, but these epidemics were very minor in Shenzhen. More influenza B epidemics occurred in Shenzhen than in Hong Kong. Conclusions: Influenza epidemics appeared to be unsynchronized between Hong Kong and Shenzhen most of the time. Given the close geographical locations of these two cities, this could be due to the strikingly different age structures of their populations. Keywords: Influenza epidemics, Synchrony, Shenzhen, Hong Kong

  20. The global spread of HIV-1 subtype B epidemic

    NARCIS (Netherlands)

    Magiorkinis, Gkikas; Angelis, Konstantinos; Mamais, Ioannis; Katzourakis, Aris; Hatzakis, Angelos; Albert, Jan; Lawyer, Glenn; Hamouda, Osamah; Struck, Daniel; Vercauteren, Jurgen; Wensing, Annemarie; Alexiev, Ivailo; Åsjö, Birgitta; Balotta, Claudia; Gomes, Perpétua; Camacho, Ricardo J.; Coughlan, Suzie; Griskevicius, Algirdas; Grossman, Zehava; Horban, Anders; Kostrikis, Leondios G.; Lepej, Snjezana J.; Liitsola, Kirsi; Linka, Marek; Nielsen, Claus; Otelea, Dan; Paredes, Roger; Poljak, Mario; Puchhammer-Stöckl, Elizabeth; Schmit, Jean Claude; Sönnerborg, Anders; Staneková, Danica; Stanojevic, Maja; Stylianou, Dora C.; Boucher, Charles A B; Nikolopoulos, Georgios; Vasylyeva, Tetyana; Friedman, Samuel R.; van de Vijver, David; Angarano, Gioacchino; Chaix, Marie Laure; de Luca, Andrea; Korn, Klaus; Loveday, Clive; Soriano, Vincent; Yerly, Sabine; Zazzi, Mauricio; Vandamme, Anne Mieke; Paraskevis, Dimitrios

    2016-01-01

    Human immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa through Haiti

  1. On The Travelling Wave Solution For An SEIR Epidemic Disease ...

    African Journals Online (AJOL)

    We present the travelling wave solution for a Susceptible, Exposed, Infective and Removed (SEIR) epidemic disease model. For this SEIR model, the disease is driven by both the latent and infective class (the diffusion term is included in both classes). The population is closed. Keywords: Epidemic model, spatial spread, ...

  2. The fastest spreader in SIS epidemics on networks

    NARCIS (Netherlands)

    He, Z.; Van Mieghem, P.F.A.

    2018-01-01

    Identifying the fastest spreaders in epidemics on a network helps to ensure an efficient spreading. By ranking the average spreading time for different spreaders, we show that the fastest spreader may change with the effective infection rate of a SIS epidemic process, which means that the

  3. Effects of local and global network connectivity on synergistic epidemics

    Science.gov (United States)

    Broder-Rodgers, David; Pérez-Reche, Francisco J.; Taraskin, Sergei N.

    2015-12-01

    Epidemics in networks can be affected by cooperation in transmission of infection and also connectivity between nodes. An interplay between these two properties and their influence on epidemic spread are addressed in the paper. A particular type of cooperative effects (called synergy effects) is considered, where the transmission rate between a pair of nodes depends on the number of infected neighbors. The connectivity effects are studied by constructing networks of different topology, starting with lattices with only local connectivity and then with networks that have both local and global connectivity obtained by random bond-rewiring to nodes within a certain distance. The susceptible-infected-removed epidemics were found to exhibit several interesting effects: (i) for epidemics with strong constructive synergy spreading in networks with high local connectivity, the bond rewiring has a negative role in epidemic spread, i.e., it reduces invasion probability; (ii) in contrast, for epidemics with destructive or weak constructive synergy spreading on networks of arbitrary local connectivity, rewiring helps epidemics to spread; (iii) and, finally, rewiring always enhances the spread of epidemics, independent of synergy, if the local connectivity is low.

  4. The severe acute respiratory syndrome epidemic in mainland China dissected

    NARCIS (Netherlands)

    W.-C. Cao (Wu-Chun); S.J. de Vlas (Sake); J.H. Richardus (Jan Hendrik)

    2011-01-01

    textabstractThis paper provides a review of a recently published series of studies that give a detailed and comprehensive documentation of the severe acute respiratory syndrome (SARS) epidemic in mainland China, which severely struck the country in the spring of 2003. The epidemic spanned a large

  5. The global spread of HIV-1 subtype B epidemic

    NARCIS (Netherlands)

    G. Magiorkinis (Gkikas); K. Angelis (Konstantinos); I. Mamais (Ioannis); Katzourakis, A. (Aris); A. Hatzakis (Angelos); J. Albert (Jan); Lawyer, G. (Glenn); O. Hamouda (Osamah); D. Struck (Daniel); J. Vercauteren (Jurgen); A. Wensing (Amj); I. Alexiev (Ivailo); B. Åsjö (Birgitta); C. Balotta (Claudia); Gomes, P. (Perpétua); R.J. Camacho (Ricardo Jorge); S. Coughlan (Suzie); A. Griskevicius (Algirdas); Z. Grossman (Zehava); Horban, A. (Anders); L.G. Kostrikis (Leondios); Lepej, S.J. (Snjezana J.); K. Liitsola (Kirsi); M. Linka (Marek); C. Nielsen; D. Otelea (Dan); R. Paredes (Roger); M. Poljak (Mario); E. Puchhammer-Stöckl (Elisabeth); J.C. Schmit; A. Sonnerborg (Anders); D. Stanekova (Danica); M. Stanojevic (Maja); Stylianou, D.C. (Dora C.); C.A.B. Boucher (Charles); Nikolopoulos, G. (Georgios); Vasylyeva, T. (Tetyana); Friedman, S.R. (Samuel R.); D.A.M.C. van de Vijver (David); G. Angarano (Guiseppe); M.L. Chaix (Marie Laure); A. de Luca (Andrea); K. Korn (Klaus); Loveday, C. (Clive); V. Soriano (Virtudes); S. Yerly (Sabine); M. Zazzi; A.M. Vandamme (Anne Mieke); D. Paraskevis (Dimitrios)

    2016-01-01

    textabstractHuman immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa

  6. Host and pathogen ecology drive the seasonal dynamics of a fungal disease, white-nose syndrome.

    Science.gov (United States)

    Langwig, Kate E; Frick, Winifred F; Reynolds, Rick; Parise, Katy L; Drees, Kevin P; Hoyt, Joseph R; Cheng, Tina L; Kunz, Thomas H; Foster, Jeffrey T; Kilpatrick, A Marm

    2015-01-22

    Seasonal patterns in pathogen transmission can influence the impact of disease on populations and the speed of spatial spread. Increases in host contact rates or births drive seasonal epidemics in some systems, but other factors may occasionally override these influences. White-nose syndrome, caused by the emerging fungal pathogen Pseudogymnoascus destructans, is spreading across North America and threatens several bat species with extinction. We examined patterns and drivers of seasonal transmission of P. destructans by measuring infection prevalence and pathogen loads in six bat species at 30 sites across the eastern United States. Bats became transiently infected in autumn, and transmission spiked in early winter when bats began hibernating. Nearly all bats in six species became infected by late winter when infection intensity peaked. In summer, despite high contact rates and a birth pulse, most bats cleared infections and prevalence dropped to zero. These data suggest the dominant driver of seasonal transmission dynamics was a change in host physiology, specifically hibernation. Our study is the first, to the best of our knowledge, to describe the seasonality of transmission in this emerging wildlife disease. The timing of infection and fungal growth resulted in maximal population impacts, but only moderate rates of spatial spread. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  7. EVALUATION AND PREDICTIVE METHODS OF EPIDEMICAL SITUATION IN THE AREA OF ACUTE ENTERIC INFECTIONS

    Directory of Open Access Journals (Sweden)

    Malysh N.G.

    2017-06-01

    temperature, humidity and rainfall. Simultaneously, should be gathered the information about the population on the investigated area, its density (for 1 km2, natural and migratory movement. When the information is gathered, begins the stage of analytical research. At first, determines the long-term tendency of the sick rate. If the average time of growth of the sick rate ranges from 0 to 1.0% - the epidemiological situation of this nosology is good, ranges from 1.1% to 5.0% - unstable, more than 5.0 % - bad. The probability of the influence of natural and social "risk factors» (X on the AII sick rate (Y calculates according to this formula: Rxy = Ʃ dx•dy / √Ʃ dx2•dy2, where Rxy - correlation coefficient; dx - departure from the arithmetical average of levels of natural or social factors; dy - departure from the arithmetical average of the annual sick rate or seasonal distribution. If it was founded an authentic correlation (p<0.05 between the average monthly rates of air temperature, humidity, rainfallы, number and density of population (per 1 km2, natural and migratory movements, and the sick rate of the AII nosological entities, the AII epidemical situation, in a case of increasing of the indicators of abovementioned "risk factors", will be also considered as unstable, which requires immediate elaboration and implementation of the targeted preventive steps. a result, the study found, that in current conditions in Sumy region the epidemical situation of shigellosis, AIIDA and AIIUE is good, according to Тred.av.= -10.7 % for shigellosis, and Тgr.av. = +0.6 % for acute intestinal infection, caused by other determined agents (AIIDA and acute intestinal infections of unknown etiology (AIIUE; epidemical situation of salmonellosis is unstable, because: Тgr.av.= +2.3 %. It was found, that the number and density of population (1 km2. Similar relationships were also found between the levels of salmonellosis sick rate and net migration rate and natural population

  8. Fungal diversity in deep-sea sediments associated with asphalt seeps at the Sao Paulo Plateau

    Science.gov (United States)

    Nagano, Yuriko; Miura, Toshiko; Nishi, Shinro; Lima, Andre O.; Nakayama, Cristina; Pellizari, Vivian H.; Fujikura, Katsunori

    2017-12-01

    We investigated the fungal diversity in a total of 20 deep-sea sediment samples (of which 14 samples were associated with natural asphalt seeps and 6 samples were not associated) collected from two different sites at the Sao Paulo Plateau off Brazil by Ion Torrent PGM targeting ITS region of ribosomal RNA. Our results suggest that diverse fungi (113 operational taxonomic units (OTUs) based on clustering at 97% sequence similarity assigned into 9 classes and 31 genus) are present in deep-sea sediment samples collected at the Sao Paulo Plateau, dominated by Ascomycota (74.3%), followed by Basidiomycota (11.5%), unidentified fungi (7.1%), and sequences with no affiliation to any organisms in the public database (7.1%). However, it was revealed that only three species, namely Penicillium sp., Cadophora malorum and Rhodosporidium diobovatum, were dominant, with the majority of OTUs remaining a minor community. Unexpectedly, there was no significant difference in major fungal community structure between the asphalt seep and non-asphalt seep sites, despite the presence of mass hydrocarbon deposits and the high amount of macro organisms surrounding the asphalt seeps. However, there were some differences in the minor fungal communities, with possible asphalt degrading fungi present specifically in the asphalt seep sites. In contrast, some differences were found between the two different sampling sites. Classification of OTUs revealed that only 47 (41.6%) fungal OTUs exhibited >97% sequence similarity, in comparison with pre-existing ITS sequences in public databases, indicating that a majority of deep-sea inhabiting fungal taxa still remain undescribed. Although our knowledge on fungi and their role in deep-sea environments is still limited and scarce, this study increases our understanding of fungal diversity and community structure in deep-sea environments.

  9. Characteristic properties of carrying out anti-epidemic arrangements during liquidation of radiation accident after-effects

    International Nuclear Information System (INIS)

    Shaposhnikov, A.A.; Konyshev, I.S.

    1995-01-01

    During liquidation of the after-effects of technogenic accidents it is necessary to maintain satisfactory sanitary and epidemiological conditions in the emergency zone and in the regions of temporary accommodation of the evacuated population, to secure epidemic safety of drinking water, edible raw materials and prepared foods, communal and other establishments. The volume and trend of anti-epidemic measures are planned depending on the type of epidemic situation. In the course of sanitary-epidemiological survey should be ascertained the prevalence of diseases among the population, epizootic among domestic animals and synanthropous rodents, the existence of natural foci of infectious diseases and their activity, the conditions of epidemically important establishments in the emergency zone, sanitary conditions of places of residence of population, the presence of transmitters of infectious diseases, the system of organization of anti-epidemic control of population and rescuers. The rehabilitation of immunological reactivity of human body up to adequate response to the antigen irritation is observed within various periods of time after recovery from radial disease (1-3 months). 17 refs.; 2 tabs

  10. Concurrency-Induced Transitions in Epidemic Dynamics on Temporal Networks.

    Science.gov (United States)

    Onaga, Tomokatsu; Gleeson, James P; Masuda, Naoki

    2017-09-08

    Social contact networks underlying epidemic processes in humans and animals are highly dynamic. The spreading of infections on such temporal networks can differ dramatically from spreading on static networks. We theoretically investigate the effects of concurrency, the number of neighbors that a node has at a given time point, on the epidemic threshold in the stochastic susceptible-infected-susceptible dynamics on temporal network models. We show that network dynamics can suppress epidemics (i.e., yield a higher epidemic threshold) when the node's concurrency is low, but can also enhance epidemics when the concurrency is high. We analytically determine different phases of this concurrency-induced transition, and confirm our results with numerical simulations.

  11. Concurrency-Induced Transitions in Epidemic Dynamics on Temporal Networks

    Science.gov (United States)

    Onaga, Tomokatsu; Gleeson, James P.; Masuda, Naoki

    2017-09-01

    Social contact networks underlying epidemic processes in humans and animals are highly dynamic. The spreading of infections on such temporal networks can differ dramatically from spreading on static networks. We theoretically investigate the effects of concurrency, the number of neighbors that a node has at a given time point, on the epidemic threshold in the stochastic susceptible-infected-susceptible dynamics on temporal network models. We show that network dynamics can suppress epidemics (i.e., yield a higher epidemic threshold) when the node's concurrency is low, but can also enhance epidemics when the concurrency is high. We analytically determine different phases of this concurrency-induced transition, and confirm our results with numerical simulations.

  12. Evaluating Subcriticality during the Ebola Epidemic in West Africa.

    Directory of Open Access Journals (Sweden)

    Wayne T A Enanoria

    Full Text Available The 2014-2015 Ebola outbreak is the largest and most widespread to date. In order to estimate ongoing transmission in the affected countries, we estimated the weekly average number of secondary cases caused by one individual infected with Ebola throughout the infectious period for each affected West African country using a stochastic hidden Markov model fitted to case data from the World Health Organization. If the average number of infections caused by one Ebola infection is less than 1.0, the epidemic is subcritical and cannot sustain itself. The epidemics in Liberia and Sierra Leone have approached subcriticality at some point during the epidemic; the epidemic in Guinea is ongoing with no evidence that it is subcritical. Response efforts to control the epidemic should continue in order to eliminate Ebola cases in West Africa.

  13. Dynamical processes and epidemic threshold on nonlinear coupled multiplex networks

    Science.gov (United States)

    Gao, Chao; Tang, Shaoting; Li, Weihua; Yang, Yaqian; Zheng, Zhiming

    2018-04-01

    Recently, the interplay between epidemic spreading and awareness diffusion has aroused the interest of many researchers, who have studied models mainly based on linear coupling relations between information and epidemic layers. However, in real-world networks the relation between two layers may be closely correlated with the property of individual nodes and exhibits nonlinear dynamical features. Here we propose a nonlinear coupled information-epidemic model (I-E model) and present a comprehensive analysis in a more generalized scenario where the upload rate differs from node to node, deletion rate varies between susceptible and infected states, and infection rate changes between unaware and aware states. In particular, we develop a theoretical framework of the intra- and inter-layer dynamical processes with a microscopic Markov chain approach (MMCA), and derive an analytic epidemic threshold. Our results suggest that the change of upload and deletion rate has little effect on the diffusion dynamics in the epidemic layer.

  14. The influence of school holiday timing on epidemic impact.

    Science.gov (United States)

    Eames, K T D

    2014-09-01

    The impact of reactive school closure on an epidemic is uncertain, since it is not clear how an unplanned closure will affect social mixing patterns. The effect of school holidays on social mixing patterns is better understood. Here, we use mathematical models to explore the influence of the timing of school holidays on the final size and peak incidence of an influenza-like epidemic. A well-timed holiday can reduce the impact of an epidemic, in particular substantially reducing an epidemic's peak. Final size and peak incidence cannot both be minimized: a later holiday is optimal for minimizing the final size, while an earlier holiday minimizes peak incidence. Using social mixing data from the UK, we estimated that, had the 2009 influenza epidemic not been interrupted by the school summer holidays, the final size would have been about 20% larger and the peak about 170% higher.

  15. Epidemic spreading between two coupled subpopulations with inner structures

    Science.gov (United States)

    Ruan, Zhongyuan; Tang, Ming; Gu, Changgui; Xu, Jinshan

    2017-10-01

    The structure of underlying contact network and the mobility of agents are two decisive factors for epidemic spreading in reality. Here, we study a model consisting of two coupled subpopulations with intra-structures that emphasizes both the contact structure and the recurrent mobility pattern of individuals simultaneously. We show that the coupling of the two subpopulations (via interconnections between them and round trips of individuals) makes the epidemic threshold in each subnetwork to be the same. Moreover, we find that the interconnection probability between two subpopulations and the travel rate are important factors for spreading dynamics. In particular, as a function of interconnection probability, the epidemic threshold in each subpopulation decreases monotonously, which enhances the risks of an epidemic. While the epidemic threshold displays a non-monotonic variation as travel rate increases. Moreover, the asymptotic infected density as a function of travel rate in each subpopulation behaves differently depending on the interconnection probability.

  16. Suppressing traffic-driven epidemic spreading by adaptive routing strategy

    International Nuclear Information System (INIS)

    Yang, Han-Xin; Wang, Zhen

    2016-01-01

    The design of routing strategies for traffic-driven epidemic spreading has received increasing attention in recent years. In this paper, we propose an adaptive routing strategy that incorporates topological distance with local epidemic information through a tunable parameter h. In the case where the traffic is free of congestion, there exists an optimal value of routing parameter h, leading to the maximal epidemic threshold. This means that epidemic spreading can be more effectively controlled by adaptive routing, compared to that of the static shortest path routing scheme. Besides, we find that the optimal value of h can greatly relieve the traffic congestion in the case of finite node-delivering capacity. We expect our work to provide new insights into the effects of dynamic routings on traffic-driven epidemic spreading.

  17. Dynamic complexities in a seasonal prevention epidemic model with birth pulses

    International Nuclear Information System (INIS)

    Gao Shujing; Chen Lansun; Sun Lihua

    2005-01-01

    In most of population dynamics, increases in population due to birth are assumed to be time-dependent, but many species reproduce only during a single period of the year. In this paper, we propose an epidemic model with density-dependent birth pulses and seasonal prevention. Using the discrete dynamical system determined by stroboscopic map, we obtain the local or global stability, numerical simulation shows there is a characteristic sequence of bifurcations, leading to chaotic dynamics, which implies that the dynamical behaviors of the epidemic model with birth pulses and seasonal prevention are very complex, including small amplitude oscillations, large-amplitude multi-annual cycles and chaos. This suggests that birth pulse, in effect, provides a natural period or cyclicity that may lead a period-doubling route to chaos

  18. Epidemics and dimensionality in hierarchical networks

    Science.gov (United States)

    Zheng, Da-Fang; Hui, P. M.; Trimper, Steffen; Zheng, Bo

    2005-07-01

    Epidemiological processes are studied within a recently proposed hierarchical network model using the susceptible-infected-refractory dynamics of an epidemic. Within the network model, a population may be characterized by H independent hierarchies or dimensions, each of which consists of groupings of individuals into layers of subgroups. Detailed numerical simulations reveal that for H>1, global spreading results regardless of the degree of homophily of the individuals forming a social circle. For H=1, a transition from global to local spread occurs as the population becomes decomposed into increasingly homophilous groups. Multiple dimensions in classifying individuals (nodes) thus make a society (computer network) highly susceptible to large-scale outbreaks of infectious diseases (viruses).

  19. Social networks and spreading of epidemics

    Science.gov (United States)

    Trimper, Steffen; Zheng, Dafang; Brandau, Marian

    2004-05-01

    Epidemiological processes are studied within a recently proposed social network model using the susceptible-infected-refractory dynamics (SIR) of an epidemic. Within the network model, a population of individuals may be characterized by H independent hierarchies or dimensions, each of which consists of groupings of individuals into layers of subgroups. Detailed numerical simulations reveals that for H > 1, the global spreading results regardless of the degree of homophily α of the individuals forming a social circle. For H = 1, a transition from a global to a local spread occurs as the population becomes decomposed into increasingly homophilous groups. Multiple dimensions in classifying individuals (nodes) thus make a society (computer network) highly susceptible to large scale outbreaks of infectious diseases (viruses). The SIR-model can be extended by the inclusion of waiting times resulting in modified distribution function of the recovered.

  20. Quarantine generated phase transition in epidemic spreading

    Science.gov (United States)

    Dicksion, Mark; Lagorio, Cecilia; Vazquez, F.; Braunstein, L.; Macri, P. A.; Migueles, M. V.; Havlin, S.; Stanley, H. E.

    2011-03-01

    We study the critical effect of quarantine on the propagation of epidemics on an adaptive network of social contacts. For this purpose, we analyze the susceptible-infected-recovered (SIR) model in the presence of quarantine, where susceptible individuals protect themselves by disconnecting their links to infected neighbors with probability w, and reconnecting them to other susceptible individuals chosen at random. Starting from a single infected individual, we show by an analytical approach and simulations that there is a phase transition at a critical rewiring (quarantine) threshold wc separating a phase (w =wc) where the disease does not spread out. We find that in our model the topology of the network strongly affects the size of the propagation, and that wc increases with the mean degree and heterogeneity of the network. We also find that wc is reduced if we perform a preferential rewiring, in which the rewiring probability is proportional to the degree of infected nodes.

  1. Epidemic Dynamics in Open Quantum Spin Systems

    Science.gov (United States)

    Pérez-Espigares, Carlos; Marcuzzi, Matteo; Gutiérrez, Ricardo; Lesanovsky, Igor

    2017-10-01

    We explore the nonequilibrium evolution and stationary states of an open many-body system that displays epidemic spreading dynamics in a classical and a quantum regime. Our study is motivated by recent experiments conducted in strongly interacting gases of highly excited Rydberg atoms where the facilitated excitation of Rydberg states competes with radiative decay. These systems approximately implement open quantum versions of models for population dynamics or disease spreading where species can be in a healthy, infected or immune state. We show that in a two-dimensional lattice, depending on the dominance of either classical or quantum effects, the system may display a different kind of nonequilibrium phase transition. We moreover discuss the observability of our findings in laser driven Rydberg gases with particular focus on the role of long-range interactions.

  2. Multilingual event extraction for epidemic detection.

    Science.gov (United States)

    Lejeune, Gaël; Brixtel, Romain; Doucet, Antoine; Lucas, Nadine

    2015-10-01

    This paper presents a multilingual news surveillance system applied to tele-epidemiology. It has been shown that multilingual approaches improve timeliness in detection of epidemic events across the globe, eliminating the wait for local news to be translated into major languages. We present here a system to extract epidemic events in potentially any language, provided a Wikipedia seed for common disease names exists. The Daniel system presented herein relies on properties that are common to news writing (the journalistic genre), the most useful being repetition and saliency. Wikipedia is used to screen common disease names to be matched with repeated characters strings. Language variations, such as declensions, are handled by processing text at the character-level, rather than at the word level. This additionally makes it possible to handle various writing systems in a similar fashion. As no multilingual ground truth existed to evaluate the Daniel system, we built a multilingual corpus from the Web, and collected annotations from native speakers of Chinese, English, Greek, Polish and Russian, with no connection or interest in the Daniel system. This data set is available online freely, and can be used for the evaluation of other event extraction systems. Experiments for 5 languages out of 17 tested are detailed in this paper: Chinese, English, Greek, Polish and Russian. The Daniel system achieves an average F-measure of 82% in these 5 languages. It reaches 87% on BEcorpus, the state-of-the-art corpus in English, slightly below top-performing systems, which are tailored with numerous language-specific resources. The consistent performance of Daniel on multiple languages is an important contribution to the reactivity and the coverage of epidemiological event detection systems. Most event extraction systems rely on extensive resources that are language-specific. While their sophistication induces excellent results (over 90% precision and recall), it restricts their

  3. Open data mining for Taiwan's dengue epidemic.

    Science.gov (United States)

    Wu, ChienHsing; Kao, Shu-Chen; Shih, Chia-Hung; Kan, Meng-Hsuan

    2018-07-01

    By using a quantitative approach, this study examines the applicability of data mining technique to discover knowledge from open data related to Taiwan's dengue epidemic. We compare results when Google trend data are included or excluded. Data sources are government open data, climate data, and Google trend data. Research findings from analysis of 70,914 cases are obtained. Location and time (month) in open data show the highest classification power followed by climate variables (temperature and humidity), whereas gender and age show the lowest values. Both prediction accuracy and simplicity decrease when Google trends are considered (respectively 0.94 and 0.37, compared to 0.96 and 0.46). The article demonstrates the value of open data mining in the context of public health care. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Chernobyl: Symptom of a worrying psychological epidemic

    International Nuclear Information System (INIS)

    Pretre, S.

    1991-01-01

    The Chernobyl psychological epidemic was already latent well prior to 1986 fully broke out after the accident, and continues to spread. It must be halted. But how can we counter a belief which has taken on the appearance of reality. It is the unknown, linked to alarming symbols, which sustains fear. To get beyond this state, radioactivity, ionizing radiation and nuclear energy have to become as ordinary as air travel and electronic calculators. In a climate of confidence and openness, it should be possible to successfully communicate several solid scientific reference points by first targeting teachers, doctors, and journalists. Thirty years ago, nuclear energy was presented as a universal panacea (clean, safe, and renewable). Now things have swung to the other extreme, and it is presented as diabolical. We have shifted from a symbolically white level to a symbolically black level, and both are misleading. It is high time to rejoin the world of facts, a world full of shades of gray

  5. A stochastic SIS epidemic model with vaccination

    Science.gov (United States)

    Cao, Boqiang; Shan, Meijing; Zhang, Qimin; Wang, Weiming

    2017-11-01

    In this paper, we investigate the basic features of an SIS type infectious disease model with varying population size and vaccinations in presence of environment noise. By applying the Markov semigroup theory, we propose a stochastic reproduction number R0s which can be seen as a threshold parameter to utilize in identifying the stochastic extinction and persistence: If R0s disease-free absorbing set for the stochastic epidemic model, which implies that disease dies out with probability one; while if R0s > 1, under some mild extra conditions, the SDE model has an endemic stationary distribution which results in the stochastic persistence of the infectious disease. The most interesting finding is that large environmental noise can suppress the outbreak of the disease.

  6. Fractional virus epidemic model on financial networks

    Directory of Open Access Journals (Sweden)

    Balci Mehmet Ali

    2016-01-01

    Full Text Available In this study, we present an epidemic model that characterizes the behavior of a financial network of globally operating stock markets. Since the long time series have a global memory effect, we represent our model by using the fractional calculus. This model operates on a network, where vertices are the stock markets and edges are constructed by the correlation distances. Thereafter, we find an analytical solution to commensurate system and use the well-known differential transform method to obtain the solution of incommensurate system of fractional differential equations. Our findings are confirmed and complemented by the data set of the relevant stock markets between 2006 and 2016. Rather than the hypothetical values, we use the Hurst Exponent of each time series to approximate the fraction size and graph theoretical concepts to obtain the variables.

  7. Epidemics scenarios in the "Romantic network".

    Directory of Open Access Journals (Sweden)

    Alexsandro M Carvalho

    Full Text Available The networks of sexual contacts together with temporal interactions play key roles in the spread of sexually transmitted infections. Unfortunately, data for this kind of network is scarce. One of the few exceptions, the "Romantic network", is a complete structure of a real sexual network in a high school. Based on many network measurements the authors of the work have concluded that it does not correspond to any other model network. Regarding the temporal structure, several studies indicate that relationship timing can have an effect on the diffusion throughout networks, as relationship order determines transmission routes. The aim is to check if the particular structure, static and dynamic, of the Romantic network is determinant for the propagation of an STI. We performed simulations in two scenarios: the static network where all contacts are available and the dynamic case where contacts evolve over time. In the static case, we compared the epidemic results in the Romantic network with some paradigmatic topologies. In the dynamic scenario, we considered the dynamics of formation of pairs in the Romantic network and we studied the propagation of the diseases. Our results suggest that although this real network cannot be labeled as a Watts-Strogatz network, it is, in regard to the propagation of an STI, very similar to a high disorder network. Additionally, we found that: the effect that any individual contacting an externally infected subject is to make the network closer to a fully connected one, the higher the contact degree of patient zero the faster the spread of the outbreaks, and the epidemic impact is proportional to the numbers of contacts per unit time. Finally, our simulations confirm that relationship timing severely reduced the final outbreak size, and also, show a clear correlation between the average degree and the outbreak size over time.

  8. Bacterial and fungal flora of seagull droppings in Jersey

    Science.gov (United States)

    Cragg, John; Clayton, Yvonne M.

    1971-01-01

    In Jersey 166 fresh and 122 dried seagull droppings were obtained and studied locally and in London for the presence of bacteria and fungi of potentially pathogenic nature. There were no salmonella or shigella bacteria isolated from the two groups but there was a high proportion of Candida albicans obtained from the fresh material (21·7%) and only 1·6% from the dry faeces. Cryptococcus neoformans and Histoplasma capsulatum were not found in either the dry or fresh droppings. The normal bacterial and fungal flora of the seagull was established and it is considered that the C. albicans in fresh gull droppings would not materially increase albicans infections in man. PMID:5104846

  9. Fungal atopy in adult cystic fibrosis.

    LENUS (Irish Health Repository)

    Henry, M

    2012-02-03

    This study set out to estimate the prevalence of atopy to a variety of common ubiquitous fungi, including A. fumigatus, in cystic fibrosis (CF), and to evaluate the investigations by which the diagnosis was made. Particular attention was paid to the usefulness of skin testing and immunoassays in detecting which patients had simple fungal atopy, and which patients were at high risk of developing allergic bronchopulmonary mycoses. This cross-sectional study included 21 adult CF patients and 20 matched controls. Serum samples were taken for the measurement of total serum IgE and specific serum IgE to nine common fungi. Immediate hypersensitivity skin prick testing to each of the fungi was also performed. Simple fungal atopy was described in subjects fulfilling the following criteria: total serum IgE > 100 KU l(-1) with specific radioimmunoassay > or = grade 1 to at least one fungus and a positive skin prick test (SPT) > or = 3 mm to the same fungus. \\'High risk\\' for developing allergic bronchopulmonary mycosis (ABPM) was described in subjects fulfilling the following criteria: total serum IgE > 200 KU l(-1) with specific radioimmunoassay > or = grade 2 to at least one fungus and a positive skin prick test (SPT) > or = 6 mm to the same fungus. The adult CF group had a significantly higher total SPT score (P=0.005) and mean total serum IgE (P<0.05) than controls. Forty-three percent of CF patients fulfilled the criteria for fungal atopy to at least a single fungus. Over half this group had an atopic tendency to more than one fungus. Nineteen percent of the CF group were at least \\'high risk\\' of developing ABPM. Skin prick testing is a better marker of fungal atopy and a better predictor of those adult CF patients at higher risk of developing ABPM than specific radioimmunoassay serum testing. There is a high prevalence of fungal atopy in the adult CF population. Total serum IgE and skin prick testing are good predictors of fungal atopy and help predict those at

  10. Transplant tourism and invasive fungal infection

    Directory of Open Access Journals (Sweden)

    I. Al Salmi

    2018-04-01

    Full Text Available Background: Deceased and live-related renal transplants (RTXs are approved procedures that are performed widely throughout the world. In certain regions, commercial RTX has become popular, driven by financial greed. Methods: This retrospective, descriptive study was performed at the Royal Hospital from 2013 to 2015. Data were collected from the national kidney transplant registry of Oman. All transplant cases retrieved were divided into two groups: live-related RTX performed in Oman and commercial-unrelated RTX performed abroad. These groups were then divided again into those with and without evidence of fungal infection, either in the wound or renal graft. Results: A total of 198 RTX patients were identified, of whom 162 (81.8% had undergone a commercial RTX that was done abroad. Invasive fungal infections (IFIs were diagnosed in 8% of patients who had undergone a commercial RTX; of these patients, 76.9% underwent a nephrectomy and 23.1% continued with a functioning graft. None of the patients with RTXs performed at the Royal Hospital contracted an IFI. The most common fungal isolates were Aspergillus species (including Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, and Aspergillus nigricans, followed by Zygomycetes. However, there was no evidence of fungal infection including Aspergillus outside the graft site. Computed tomography (CT findings showed infarction of the graft, renal artery thrombosis, aneurysmal dilatation of the external iliac artery, fungal ball, or just the presence of a perigraft collection. Of the total patients with IFIs, 23.1% died due to septic shock and 53.8% were alive and on hemodialysis. The remaining 23.1% who did not undergo nephrectomy demonstrated acceptable graft function. Conclusions: This is the largest single-center study on commercial RTX reporting the highest number of patients with IFI acquired over a relatively short period of time. Aspergillus spp were the main culprit fungi, with no

  11. Analysis of the epidemiological dynamics during the 1982-1983 epidemic of foot-and-mouth disease in Denmark based on molecular high-resolution strain identification

    DEFF Research Database (Denmark)

    Christensen, Laurids Siig; Normann, Preben; Thykier-Nielsen, Søren

    2005-01-01

    An epidemic of foot-and-mouth disease (FMD) causing a total of 23 cases in 1982-1983, primarily on the island of Funen, Denmark, was subjected to molecular epidemiological investigations. In an attempt to exploit the quasi-species nature of foot-and-mouth disease virus strains for molecular high......-resolution strain identification in order to analyse the dynamics of this epidemic, full-length VP1 coding regions were sequenced for 17 isolates collected at different farms during the epidemic. The sequence information together with epidemiological information gathered during the epidemic suggests......, and the prerequisite of co- or superinfection of animals with variant strains in turn implies that they have a common source or epidemiologically related sources originating from an area with endemic FMD....

  12. Fiber, food, fuel, and fungal symbionts.

    Science.gov (United States)

    Ruehle, J L; Marx, D H

    1979-10-26

    Virtually all plants of economic importance form mycorrhizae. These absorbing organs of higher plants result from a symbiotic union of beneficial soil fungi and feeder roots. In forestry, the manipulation of fungal symbionts ecologically adapted to the planting site can increase survival and growth of forest trees, particularly on adverse sites. Vesicular-arbuscular mycorrhizae, which occur not only on many trees but also on most cultivated crops, are undoubtedly more important to world food crops. Imperatives for mycorrhizal research in forestry and agriculture are (i) the development of mass inoculum of mycorrhizal fungi, (ii) the interdisciplinary coordination with soil management, plant breeding, cultivation practices, and pest control to ensure maximum survival and development of fungal symbionts in the soil, and (iii) the institution of nursery and field tests to determine the circumstances in which mycorrhizae benefit plant growth in forestry and agri-ecosystems.

  13. Fungal enzymes in the attine ant symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    the more basal attine genera use substrates such as flowers, plant debris, small twigs, insect feces and insect carcasses. This diverse array of fungal substrates across the attine lineage implies that the symbiotic fungus needs different enzymes to break down the plant material that the ants provide...... or different efficiencies of enzyme function. Fungal enzymes that degrade plant cell walls may have functionally co-evolved with the ants in this scenario. We explore this hypothesis with direct measurements of enzyme activity in fungus gardens in 12 species across 8 genera spanning the entire phylogeny...... and diversity of life-styles within the attine clade. We find significant differences in enzyme activity between different genera and life-styles of the ants. How these findings relate to attine ant coevolution and crop optimization are discussed....

  14. Burden of serious fungal infections in Bangladesh.

    Science.gov (United States)

    Gugnani, H C; Denning, D W; Rahim, R; Sadat, A; Belal, M; Mahbub, M S

    2017-06-01

    In Bangladesh there are several published papers on superficial mycoses. Deep mycoses are also recognized as an important emerging problem. Here, we estimate the annual incidence and prevalence of serious fungal infections in Bangladesh. Demographic data were obtained from world population reports and the data on TB and HIV extracted from the online publications on tuberculosis in Bangladesh and Asia Pacific research statistical data information resources AIDS Data HUB. All the published papers on fungal infections in Bangladesh were identified through extensive search of literature. We estimated the number of affected people from populations at risk and local epidemiological data. Bangladesh has a population of ∼162.6 million, 31% children and only 6% over the age of 60 years. The pulmonary TB caseload reported in 2014 was 119,520, and we estimate a prevalence of 30,178 people with chronic pulmonary aspergillosis, 80% attributable to TB. An anticipated 90,262 and 119,146 patients have allergic bronchopulmonary aspergillosis or severe asthma with fungal sensitization. Only 8,000 people are estimated to be HIV-infected, of whom 2900 are not on ART with a CD4 count Bangladesh. Candida bloodstream infection was estimated based on a 5 per 100,000 rate (8100 cases) and invasive aspergillosis based primarily on leukemia and COPD rates, at 5166 cases. Histoplasmosis was documented in 16 cases mostly with disseminated disease and presumed in 21 with HIV infection. This study constitutes the first attempt to estimate the burden of several types of serious fungal infections in Bangladesh.

  15. Burden of serious fungal infections in Ukraine.

    Science.gov (United States)

    Osmanov, Ali; Denning, David W

    2015-10-01

    Ukraine has high rates of TB, AIDS and cancer. We estimated the burden of fungal disease from epidemiology papers and specific populations at risk and fungal infection frequencies. HIV/AIDS cases and deaths (2012) and tuberculosis statistics were obtained from the State Service of Ukraine, while chronic obstructive pulmonary disease (COPD) cases were from M. Miravitlles et al., Thorax 64, 863-868 (2009). Annual estimates are 893,579 Ukrainian women get recurrent vaginal thrush (≥4× per year), 50,847 cases of oral candidiasis and 13,727 cases of oesophageal candidiasis in HIV, and 101 (1%) of 10,085 new AIDS cases develop cryptococcal meningitis, 6152 cases of Pneumocystis pneumonia (13.5 cases per 100,000). Of the 29,265 cases of active respiratory TB in 2012, it is estimated that 2881 new cases of chronic pulmonary aspergillosis (CPA) occurred and that the 5-year period prevalence is 7724 cases with a total CPA burden of 10,054 cases. Assuming adult asthma prevalence is ~2.9%, 28,447 patients with allergic bronchopulmonary aspergillosis (ABPA) are likely and 37,491 with severe asthma with fungal sensitisation. We estimate 2278 cases and 376 postsurgical intra-abdominal Candida infections. Invasive aspergillosis in immunocompromised patients is estimated at 303 patients annually; 930 cases in COPD patients. Ninety cases of mucormycosis (2 per 1,000,000) are estimated. In total, ~1,000,000 (2.2%) people in Ukraine develop serious fungal infections annually. © 2015 Blackwell Verlag GmbH.

  16. Bacterial, Fungal, Parasitic, and Viral Myositis

    OpenAIRE

    Crum-Cianflone, Nancy F.

    2008-01-01

    Infectious myositis may be caused by a broad range of bacterial, fungal, parasitic, and viral agents. Infectious myositis is overall uncommon given the relative resistance of the musculature to infection. For example, inciting events, including trauma, surgery, or the presence of foreign bodies or devitalized tissue, are often present in cases of bacterial myositis. Bacterial causes are categorized by clinical presentation, anatomic location, and causative organisms into the categories of pyo...

  17. Fungal Systematics and Evolution: FUSE 1

    OpenAIRE

    Crous, Pedro W; Schumacher, René K; Wingfield, Michael J; Lombard, Lorenzo; Giraldo, Alejandra; Christensen, Martha; Gardiennet, Alain; Nakashima, Chiharu; Pereira, Olinto L; Smith, Alexander J; Groenewald, Johannes Z

    2015-01-01

    Fungal Systematics and Evolution (FUSE) is introduced as a new series to expedite the publication of issues relating to the epitypification of formerly described species, report new sexual-asexual connections, the merging of sexual and asexual gen¬era following the end of dual nomenclature, and to describe species or note interesting observations regarding fungi. This first paper includes 18 new combinations, 13 new species, three new genera and one new family. All taxa are ascomycetes, excep...

  18. Invasive fungal infections in endogenous Cushing's syndrome

    Science.gov (United States)

    Scheffel, Rafael Selbach; Dora, José Miguel; Weinert, Letícia Schwerz; Aquino, Valério; Maia, Ana Luiza; Canani, Luis Henrique; Goldani, Luciano Z.

    2010-01-01

    Cushing's syndrome is a condition characterized by elevated cortisol levels that can result from either augmented endogenous production or exogenous administration of corticosteroids. The predisposition to fungal infections among patients with hypercortisolemia has been noted since Cushing's original description of the disease. We describe here a patient with endogenous Cushing's syndrome secondary to an adrenocortical carcinoma, who developed concomitant disseminated cryptococcosis and candidiasis in the course of his disease. PMID:24470886

  19. Burden of Serious Fungal Infections in Argentina

    Directory of Open Access Journals (Sweden)

    Fernando O. Riera

    2018-04-01

    Full Text Available The number of fungal infections at any given time in Argentina is not known. Here we estimate the burden of serious fungal infections in Argentina for the first time. Specific population statistics were searched from multiple sources, local literature was identified, and estimates made. Some additional data were sourced from the Ministry of Health, the Global Initiative for Asthma (GINA program, and national haematology and transplant societies. Argentina has a population of 43.8 million, with 25% of this total being children under 15 years. The predicted candidemia annual incidence is 2193 cases, with 50% occurring in the ICU. At a 6% prevalence rate, an estimated 593,695 women suffer from recurrent vulvovaginal candidiasis. Invasive aspergillosis is relatively common because of high smoking and chronic obstructive pulmonary disease (COPD rates, with 268 cases in immunocompromised patients and another 1938 in the 168,000 COPD patients admitted to hospital. Asthma is also common, affecting 14% of adults, and so allergic bronchopulmonary aspergillosis (ABPA and severe asthma with fungal sensitization (SAFS are major problems. An estimated 432 cases of cryptococcal meningitis (CM—90% of them in AIDS patients—and 1177 cases of Pneumocystis pneumonia (PCP occur each year. The estimated annual case number of disseminated histoplasmosis is 404 in AIDS patients, almost as frequent as CM. Paracoccidioidomycosis annual incidence is estimated at 219, and coccidioidomycosis at 16 cases. At least 881,023 people (>2.01% in Argentina are affected by a serious fungal disease annually, with considerable morbidity and mortality.

  20. Mutually cooperative epidemics on power-law networks

    Science.gov (United States)

    Cui, Peng-Bi; Colaiori, Francesca; Castellano, Claudio

    2017-08-01

    The spread of an infectious disease can, in some cases, promote the propagation of other pathogens favoring violent outbreaks, which cause a discontinuous transition to an endemic state. The topology of the contact network plays a crucial role in these cooperative dynamics. We consider a susceptible-infected-removed-type model with two mutually cooperative pathogens: An individual already infected with one disease has an increased probability of getting infected by the other. We present a heterogeneous mean-field theoretical approach to the coinfection dynamics on generic uncorrelated power-law degree-distributed networks and validate its results by means of numerical simulations. We show that, when the second moment of the degree distribution is finite, the epidemic transition is continuous for low cooperativity, while it is discontinuous when cooperativity is sufficiently high. For scale-free networks, i.e., topologies with diverging second moment, the transition is instead always continuous. In this way we clarify the effect of heterogeneity and system size on the nature of the transition, and we validate the physical interpretation about the origin of the discontinuity.

  1. Can influenza epidemics be prevented by voluntary vaccination?

    Directory of Open Access Journals (Sweden)

    Raffaele Vardavas

    2007-05-01

    Full Text Available Previous modeling studies have identified the vaccination coverage level necessary for preventing influenza epidemics, but have not shown whether this critical coverage can be reached. Here we use computational modeling to determine, for the first time, whether the critical coverage for influenza can be achieved by voluntary vaccination. We construct a novel individual-level model of human cognition and behavior; individuals are characterized by two biological attributes (memory and adaptability that they use when making vaccination decisions. We couple this model with a population-level model of influenza that includes vaccination dynamics. The coupled models allow individual-level decisions to influence influenza epidemiology and, conversely, influenza epidemiology to influence individual-level decisions. By including the effects of adaptive decision-making within an epidemic model, we can reproduce two essential characteristics of influenza epidemiology: annual variation in epidemic severity and sporadic occurrence of severe epidemics. We suggest that individual-level adaptive decision-making may be an important (previously overlooked causal factor in driving influenza epidemiology. We find that severe epidemics cannot be prevented unless vaccination programs offer incentives. Frequency of severe epidemics could be reduced if programs provide, as an incentive to be vaccinated, several years of free vaccines to individuals who pay for one year of vaccination. Magnitude of epidemic amelioration will be determined by the number of years of free vaccination, an individuals' adaptability in decision-making, and their memory. This type of incentive program could control epidemics if individuals are very adaptable and have long-term memories. However, incentive-based programs that provide free vaccination for families could increase the frequency of severe epidemics. We conclude that incentive-based vaccination programs are necessary to control

  2. A Study Of Fungal Colonization In Newborn

    Directory of Open Access Journals (Sweden)

    S Rashid Husain

    1997-04-01

    Full Text Available Research Problem: What are the factors responsible for fungal colonization in newborns? Objective: To study the pattern of and predisposing fac­tors for the development of superficial candidiasis and fungal colonization in the newborns. Study Design: Prospective study. Setting: Neonatology unitof the Paediatrics department of a teaching hospital. Participants: Randomly selected pregnant mothers admit­ted to the maternity ward and the newborns delivered to them. Sample Size: 120 pregnant mothers and the newborns delivered. Study Variables: Candida, Site of colonization. Statistical Analysis: By tests of significance Results: Candida was isolated from 23 (19.16% infants on the first day increasing to 52 (43.33% infants on the sixth day. The most common site of colonization was oral cavity. Candida colonization was more common in prema­ture infants (p<0.05. Oral thrush was seen in 29 (24.17% infants during the study and a significant number of these infants showed colonization from the first day of life. Conclusions: Fungal colonization of the newborns due to Candida species is quite common, and in the first week of life predominantly occurred in the ora I cavity. Superficial clinical candidiasis, especially oral thrush is more common in those colonized on the first day of life.

  3. Fungal myositis in children: serial ultrasonographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jung Hwa; Lee, Hee Jung; Choi, Jin Soo [Keimyung University School of Medicine, Daegu (Korea, Republic of)

    2003-08-01

    To evaluate serial ultrasonographic findings of fungal myositis in children. Eleven lesions caused by fungal myositis and occurring in six children were included in this study. Eight lesions in five children were histopathologically proven and the other three were clinically diagnosed. Serial ultrasonographic findings were retrospectively evaluated in terms of size, location, margin, internal echotexture and adjacent cortical change occurring during the follow-up period ranging from five days to two months. Three patients (50%) had multiple lesions. The sites of involvment were the thigh (n=4), calf (n=3), chest wall (n=2), abdominal wall (n=1) and forearm (n=1). Initially, diffuse muscular swelling was revealed, with ill-defined hypoechoic lesions confined to the muscle layer (n=8). Follow-up examination of eight lesions over a period of 5-10 days showed that round central echogenic lesions were surrounded by previous slightly echogenic lesions (n=6, 75%). Long-term follow-up of five lesions over a two-month period revealed periosteal thickening in one case (20%), and the peristence of echogenic solid nodules in four (80%). Pathologic examination showed that the central lesions correlated with a fungus ball and the peripheral slightly echogenic lesions corresponded to hematoma and necrosis. Serial ultrasonographic findings of fungal myositis in children revealed relatively constant features in each case. In particular, the findings of muscular necrosis and a fungus ball over a period of 5-14 days were thought to be characteristic.

  4. Fungal myositis in children: serial ultrasonographic findings

    International Nuclear Information System (INIS)

    Kwon, Jung Hwa; Lee, Hee Jung; Choi, Jin Soo

    2003-01-01

    To evaluate serial ultrasonographic findings of fungal myositis in children. Eleven lesions caused by fungal myositis and occurring in six children were included in this study. Eight lesions in five children were histopathologically proven and the other three were clinically diagnosed. Serial ultrasonographic findings were retrospectively evaluated in terms of size, location, margin, internal echotexture and adjacent cortical change occurring during the follow-up period ranging from five days to two months. Three patients (50%) had multiple lesions. The sites of involvment were the thigh (n=4), calf (n=3), chest wall (n=2), abdominal wall (n=1) and forearm (n=1). Initially, diffuse muscular swelling was revealed, with ill-defined hypoechoic lesions confined to the muscle layer (n=8). Follow-up examination of eight lesions over a period of 5-10 days showed that round central echogenic lesions were surrounded by previous slightly echogenic lesions (n=6, 75%). Long-term follow-up of five lesions over a two-month period revealed periosteal thickening in one case (20%), and the peristence of echogenic solid nodules in four (80%). Pathologic examination showed that the central lesions correlated with a fungus ball and the peripheral slightly echogenic lesions corresponded to hematoma and necrosis. Serial ultrasonographic findings of fungal myositis in children revealed relatively constant features in each case. In particular, the findings of muscular necrosis and a fungus ball over a period of 5-14 days were thought to be characteristic

  5. Bacterial - Fungal Interactions: ecology, mechanisms and challenges.

    Science.gov (United States)

    Deveau, A; Bonito, G; Uehling, J; Paoletti, M; Becker, M; Bindschedler, S; Hacquard, S; Hervé, V; Labbé, J; Lastovetsky, O A; Mieszkin, S; Millet, L J; Vajna, B; Junier, P; Bonfante, P; Krom, B P; Olsson, S; Elsas, J D van; Wick, L Y

    2018-02-19

    Fungi and bacteria are found living together in a wide variety of environments. Their interactions are significant drivers of many ecosystem functions and are important for the health of plants and animals. A large number of fungal and bacterial families are engaged in complex interactions that lead to critical behavioural shifts of the microorganisms ranging from mutualism to pathogenicity. The importance of bacterial-fungal interactions (BFI) in environmental science, medicine and biotechnology has led to the emergence of a dynamic and multidisciplinary research field that combines highly diverse approaches including molecular biology, genomics, geochemistry, chemical and microbial ecology, biophysics and ecological modelling. In this review, we discuss most recent advances that underscore the roles of BFI across relevant habitats and ecosystems. A particular focus is placed on the understanding of BFI within complex microbial communities and in regards of the metaorganism concept. We also discuss recent discoveries that clarify the (molecular) mechanisms involved in bacterial-fungal relationships, and the contribution of new technologies to decipher generic principles of BFI in terms of physical associations and molecular dialogues. Finally, we discuss future directions for researches in order to catalyse a synergy within the BFI research area and to resolve outstanding questions.

  6. Risk of Fungal Infection to Dental Patients

    Directory of Open Access Journals (Sweden)

    Jaqueline Lopes Damasceno

    2017-01-01

    Full Text Available Fungi can cause various diseases, and some pathogenic fungi have been detected in the water of dental equipment. This environment offers suitable conditions for fungal biofilms to emerge, which can facilitate mycological contamination. This study verified whether the water employed in the dental units of two dental clinics at the University of Franca was contaminated with fungi. This study also evaluated the ability of the detected fungi to form biofilms. The high-revving engine contained the largest average amount of fungi, 14.93 ± 18.18 CFU/mL. The main fungal species verified in this equipment belonged to the genera Aspergillus spp., Fusarium spp., Candida spp., and Rhodotorula spp. Among the isolated filamentous fungi, only one fungus of the genus Fusarium spp. did not form biofilms. As for yeasts, all the Candida spp. isolates grew as biofilm, but none of the Rhodotorula spp. isolates demonstrated this ability. Given that professionals and patients are often exposed to water and aerosols generated by the dental procedure, the several fungal species detected herein represent a potential risk especially to immunocompromised patients undergoing dental treatment. Therefore, frequent microbiological monitoring of the water employed in dental equipment is crucial to reduce the presence of contaminants.

  7. Fungal Production and Manipulation of Plant Hormones.

    Science.gov (United States)

    Fonseca, Sandra; Radhakrishnan, Dhanya; Prasad, Kalika; Chini, Andrea

    2018-01-01

    Living organisms are part of a highly interconnected web of interactions, characterised by species nurturing, competing, parasitizing and preying on one another. Plants have evolved cooperative as well as defensive strategies to interact with neighbour organisms. Among these, the plant-fungus associations are very diverse, ranging from pathogenic to mutualistic. Our current knowledge of plant-fungus interactions suggests a sophisticated coevolution to ensure dynamic plant responses to evolving fungal mutualistic/pathogenic strategies. The plant-fungus communication relies on a rich chemical language. To manipulate the plant defence mechanisms, fungi produce and secrete several classes of biomolecules, whose modeof- action is largely unknown. Upon perception of the fungi, plants produce phytohormones and a battery of secondary metabolites that serve as defence mechanism against invaders or to promote mutualistic associations. These mutualistic chemical signals can be co-opted by pathogenic fungi for their own benefit. Among the plant molecules regulating plant-fungus interaction, phytohormones play a critical role since they modulate various aspects of plant development, defences and stress responses. Intriguingly, fungi can also produce phytohormones, although the actual role of fungalproduced phytohormones in plant-fungus interactions is poorly understood. Here, we discuss the recent advances in fungal production of phytohormone, their putative role as endogenous fungal signals and how fungi manipulate plant hormone balance to their benefits. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. A simple method of genomic DNA extraction suitable for analysis of bulk fungal strains.

    Science.gov (United States)

    Zhang, Y J; Zhang, S; Liu, X Z; Wen, H A; Wang, M

    2010-07-01

    A simple and rapid method (designated thermolysis) for extracting genomic DNA from bulk fungal strains was described. In the thermolysis method, a few mycelia or yeast cells were first rinsed with pure water to remove potential PCR inhibitors and then incubated in a lysis buffer at 85 degrees C to break down cell walls and membranes. This method was used to extract genomic DNA from large numbers of fungal strains (more than 92 species, 35 genera of three phyla) isolated from different sections of natural Ophiocordyceps sinensis specimens. Regions of interest from high as well as single-copy number genes were successfully amplified from the extracted DNA samples. The DNA samples obtained by this method can be stored at -20 degrees C for over 1 year. The method was effective, easy and fast and allowed batch DNA extraction from multiple fungal isolates. Use of the thermolysis method will allow researchers to obtain DNA from fungi quickly for use in molecular assays. This method requires only minute quantities of starting material and is suitable for diverse fungal species.

  9. Cereal fungal infection, mycotoxins, and lactic acid bacteria mediated bioprotection: from crop farming to cereal products.

    Science.gov (United States)

    Oliveira, Pedro M; Zannini, Emanuele; Arendt, Elke K

    2014-02-01

    Lactic acid bacteria (LAB) metabolites are a reliable alternative for reducing fungal infections pre-/post-harvest with additional advantages for cereal-base products which convene the food market's trend. Grain industrial use is in expansion owing to its applicability in generating functional food. The food market is directed towards functional natural food with clear health benefits for the consumer in detriment to chemical additives. The food market chain is becoming broader and more complex, which presents an ever-growing fungal threat. Toxigenic and spoilage fungi are responsible for numerous diseases and economic losses. Cereal infections may occur in the field or post-processing, along the food chain. Consequently, the investigation of LAB metabolites with antifungal activity has gained prominence in the scientific research community. LAB bioprotection retards the development of fungal diseases in the field and inhibit pathogens and spoilage fungi in food products. In addition to the health safety improvement, LAB metabolites also enhance shelf-life, organoleptic and texture qualities of cereal-base foods. This review presents an overview of the fungal impact through the cereal food chain leading to investigation on LAB antifungal compounds. Applicability of LAB in plant protection and cereal industry is discussed. Specific case studies include Fusarium head blight, malting and baking. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Plant-ants feed their host plant, but above all a fungal symbiont to recycle nitrogen.

    Science.gov (United States)

    Defossez, Emmanuel; Djiéto-Lordon, Champlain; McKey, Doyle; Selosse, Marc-André; Blatrix, Rumsaïs

    2011-05-07

    In ant-plant symbioses, plants provide symbiotic ants with food and specialized nesting cavities (called domatia). In many ant-plant symbioses, a fungal patch grows within each domatium. The symbiotic nature of the fungal association has been shown in the ant-plant Leonardoxa africana and its protective mutualist ant Petalomyrmex phylax. To decipher trophic fluxes among the three partners, food enriched in (13)C and (15)N was given to the ants and tracked in the different parts of the symbiosis up to 660 days later. The plant received a small, but significant, amount of nitrogen from the ants. However, the ants fed more intensively the fungus. The pattern of isotope enrichment in the system indicated an ant behaviour that functions specifically to feed the fungus. After 660 days, the introduced nitrogen was still present in the system and homogeneously distributed among ant, plant and fungal compartments, indicating efficient recycling within the symbiosis. Another experiment showed that the plant surface absorbed nutrients (in the form of simple molecules) whether or not it is coated by fungus. Our study provides arguments for a mutualistic status of the fungal associate and a framework for investigating the previously unsuspected complexity of food webs in ant-plant mutualisms.

  11. Five challenges for stochastic epidemic models involving global transmission

    Directory of Open Access Journals (Sweden)

    Tom Britton

    2015-03-01

    Full Text Available The most basic stochastic epidemic models are those involving global transmission, meaning that infection rates depend only on the type and state of the individuals involved, and not on their location in the population. Simple as they are, there are still several open problems for such models. For example, when will such an epidemic go extinct and with what probability (questions depending on the population being fixed, changing or growing? How can a model be defined explaining the sometimes observed scenario of frequent mid-sized epidemic outbreaks? How can evolution of the infectious agent transmission rates be modelled and fitted to data in a robust way?

  12. Epidemic Spread in Networks Induced by Deactivation Mechanism

    International Nuclear Information System (INIS)

    Yu Xiaoling; Wu Xiao; Zhang Duanming; Li Zhihao; Liang Fang; Wang Xiaoyu

    2008-01-01

    We have studied the topology and epidemic spreading behaviors on the networks in which deactivation mechanism and long-rang connection are coexisted. By means of numerical simulation, we find that the clustering coefficient C and the Pearson correlation coefficient r decrease with increasing long-range connection μ and the topological state of the network changes into that of BA model at the end (when μ = 1). For the Susceptible-Infect-Susceptible model of epidemics, the epidemic threshold can reach maximum value at μ = 0.4 and presents two different variable states around μ = 0.4

  13. Know your epidemic, know your response: targeting HIV in Asia

    DEFF Research Database (Denmark)

    Lazarus, Jeff; Curth, Nadja; Bridge, Jamie

    2010-01-01

    This article provides an overview of the HIV epidemic in Asia, the context within which the epidemic is evolving, and the key actions to address the challenges faced by countries and risk groups. HIV epidemics across Asia are predominantly concentrated among most-at-risk populations. Although...... prevention and treatment services. In order to reach the Millennium Development Goal of halting and reversing the spread of HIV by 2015 and to achieve universal access to HIV treatment, these barriers must be overcome across Asia. High-impact programs must be targeted at those in need, with continuous...

  14. The impact of awareness on epidemic spreading in networks.

    Science.gov (United States)

    Wu, Qingchu; Fu, Xinchu; Small, Michael; Xu, Xin-Jian

    2012-03-01

    We explore the impact of awareness on epidemic spreading through a population represented by a scale-free network. Using a network mean-field approach, a mathematical model for epidemic spreading with awareness reactions is proposed and analyzed. We focus on the role of three forms of awareness including local, global, and contact awareness. By theoretical analysis and simulation, we show that the global awareness cannot decrease the likelihood of an epidemic outbreak while both the local awareness and the contact awareness can. Also, the influence degree of the local awareness on disease dynamics is closely related with the contact awareness.

  15. Inhomogeneity of epidemic spreading with entropy-based infected clusters.

    Science.gov (United States)

    Wen-Jie, Zhou; Xing-Yuan, Wang

    2013-12-01

    Considering the difference in the sizes of the infected clusters in the dynamic complex networks, the normalized entropy based on infected clusters (δ*) is proposed to characterize the inhomogeneity of epidemic spreading. δ* gives information on the variability of the infected clusters in the system. We investigate the variation in the inhomogeneity of the distribution of the epidemic with the absolute velocity v of moving agent, the infection density ρ, and the interaction radius r. By comparing δ* in the dynamic networks with δH* in homogeneous mode, the simulation experiments show that the inhomogeneity of epidemic spreading becomes smaller with the increase of v, ρ, r.

  16. The psychiatric epidemic in the American workplace.

    Science.gov (United States)

    Brodsky, C M

    1988-01-01

    make renouncement tantamount to betrayal. The mass psychogenic illness or psychiatric epidemic that occurs in the workplace offers an opportunity not only to study the elements of a biopsychosocial system, but also offers opportunities for medical anthropological studies that relate the causes and courses of specific episodes of MPI to the cultures of the individuals who develop symptoms and the cultures of the area in which the epidemic occurs.

  17. Expression of cytokines in aqueous humor from fungal keratitis patients.

    Science.gov (United States)

    Zhang, Yingnan; Liang, Qingfeng; Liu, Yang; Pan, Zhiqiang; Baudouin, Christophe; Labbé, Antoine; Lu, Qingxian

    2018-04-19

    Although a series of reports on corneal fungal infection have been published, studies on pathogenic mechanisms and inflammation-associated cytokines remain limited. In this study, aqueous humor samples from fungal keratitis patients were collected to examine cytokine patterns and cellular profile for the pathogenesis of fungal keratitis. The aqueous humor samples were collected from ten patients with advanced stage fungal keratitis. Eight aqueous humor samples from patients with keratoconus or corneal dystrophy were taken as control. Approximately 100 μl to 300 μl of aqueous humor in each case were obtained for examination. The aqueous humor samples were centrifuged and the cells were stained and examined under optical microscope. Bacterial and fungal cultures were performed on the aqueous humor and corneal buttons of all patients. Cytokines related to inflammation including IL-1β, IL-6, IL-8, IL-10, TNF-α, and IFN-γ were examined using multiplex bead-based Luminex liquid protein array systems. Fungus infection was confirmed in these ten patients by smear stains and/or fungal cultures. Bacterial and fungal cultures revealed negative results in all aqueous humor specimens. Polymorphonuclear leukocytes were the predominant infiltrating cells in the aqueous humor of fungal keratitis. At the advanced stages of fungal keratitis, the levels of IL-1β, IL-6, IL-8, and IFN-γ in the aqueous humor were significantly increased when compared with control (phumor was associated with fungal keratitis.

  18. Transplant tourism and invasive fungal infection.

    Science.gov (United States)

    Al Salmi, I; Metry, A M; Al Ismaili, F; Hola, A; Al Riyami, M; Khamis, F; Al-Abri, S

    2018-04-01

    Deceased and live-related renal transplants (RTXs) are approved procedures that are performed widely throughout the world. In certain regions, commercial RTX has become popular, driven by financial greed. This retrospective, descriptive study was performed at the Royal Hospital from 2013 to 2015. Data were collected from the national kidney transplant registry of Oman. All transplant cases retrieved were divided into two groups: live-related RTX performed in Oman and commercial-unrelated RTX performed abroad. These groups were then divided again into those with and without evidence of fungal infection, either in the wound or renal graft. A total of 198 RTX patients were identified, of whom 162 (81.8%) had undergone a commercial RTX that was done abroad. Invasive fungal infections (IFIs) were diagnosed in 8% of patients who had undergone a commercial RTX; of these patients, 76.9% underwent a nephrectomy and 23.1% continued with a functioning graft. None of the patients with RTXs performed at the Royal Hospital contracted an IFI. The most common fungal isolates were Aspergillus species (including Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, and Aspergillus nigricans), followed by Zygomycetes. However, there was no evidence of fungal infection including Aspergillus outside the graft site. Computed tomography (CT) findings showed infarction of the graft, renal artery thrombosis, aneurysmal dilatation of the external iliac artery, fungal ball, or just the presence of a perigraft collection. Of the total patients with IFIs, 23.1% died due to septic shock and 53.8% were alive and on hemodialysis. The remaining 23.1% who did not undergo nephrectomy demonstrated acceptable graft function. This is the largest single-center study on commercial RTX reporting the highest number of patients with IFI acquired over a relatively short period of time. Aspergillus spp were the main culprit fungi, with no Candida spp being isolated. A high index of suspicion might

  19. Fungal Urinary Tract Infection in Burn Patients‎

    Directory of Open Access Journals (Sweden)

    Suad Yousuf Aldorkee

    2017-11-01

    Full Text Available Background: Urinary tract infection is the most common hospital-acquired infection. Fungal species are unusual causes of urinary tract infection in healthy individuals, but common in the hospital setting or among patients with predisposing diseases and structural abnormalities of the kidney and collecting system. Burn patients are susceptible to nosocomial infections owing to the immunocompromising effects of burn injury, cutaneous and respiratory tract injury, prolonged intensive care unit stays and broad-spectrum antibiotic therapy. Objective: The study population includes adult patients of both genders who presented with different percentages of body burns. Urine sample was collected from each patient at the time of admission and weekly thereafter for 6 weeks and sent for general urine examination and urine culture to test for the possibility of fungal growth. Those who found to develop fungal UTI by urine culture during their hospitalization and had no infection at the time of admission were selected as subjects for our study. Results: 28 (18.6% patients had positive fungal culture during their hospitalization, 11 of them were males and 17 were females, the most common age of presentation was 41-50 years and the mean age ± SD was (44.4 ± 10.7 years. The most common isolated fungi were Candida albicans (64.3%, followed by Candida glabrata (21.4% and Candida tropicalis (7.1%. The majority of patients developed infection within the 2nd and 3rd weeks of hospitalization, however, those who presented with total body surface area burned > 40% developed an earlier infection within the 1st week. Female gender, urethral catheterization and diabetes mellitus were significantly associated with higher risk of infection as the P values were 0.03, 0.005 and 0.004 respectively. Conclusion: Fungal urinary tract infection occurred in 18.6% of burn patients. The most common causative fungi are candida species. Advanced age, female gender, high percentage of

  20. Rape and HIV post-exposure prophylaxis: addressing the dual epidemics in South Africa.

    Science.gov (United States)

    Kim, Julia C; Martin, Lorna J; Denny, Lynette

    2003-11-01

    In South Africa, a country notable for both a rapidly escalating AIDS epidemic and high levels of sexual violence, the issue of HIV post-exposure prophylaxis (PEP) following rape has recently come to the fore, and a policy supporting provision of PEP has been approved by the national government. This paper compares the conditions for providing PEP in Europe and North America with the conditions faced by two initiatives in South Africa, one serving a primarily rural base, and one urban. It is based on a review of the literature on sexual violence in South Africa and use of PEP following occupational and non-occupational exposure. It incorporates perspectives from in-depth interviews in 2000 with 18 key informants, including survivors of sexual violence, gender and HIV activists, domestic violence NGOs, rape crisis centres, physicians, lawyers, researchers and HIV/AIDS advisors in the Department of Health. The paper argues that given the scientific evidence for PEP, and the nature of the dual epidemics of HIV and sexual violence in South Africa, the public health and social justice rationale for implementing PEP equals and indeed exceeds that put forward in industrialised countries. However, delays in accessing PEP caused by the public justice system and lack of training for service providers constitute significant obstacles to effective implementation. In this respect, provision of PEP presents an opportunity to reform and strengthen existing services for post-rape care and to link attention to the epidemic of sexual violence to HIV/AIDS prevention.

  1. FluTE, a publicly available stochastic influenza epidemic simulation model.

    Directory of Open Access Journals (Sweden)

    Dennis L Chao

    2010-01-01

    Full Text Available Mathematical and computer models of epidemics have contributed to our understanding of the spread of infectious disease and the measures needed to contain or mitigate them. To help prepare for future influenza seasonal epidemics or pandemics, we developed a new stochastic model of the spread of influenza across a large population. Individuals in this model have realistic social contact networks, and transmission and infections are based on the current state of knowledge of the natural history of influenza. The model has been calibrated so that outcomes are consistent with the 1957/1958 Asian A(H2N2 and 2009 pandemic A(H1N1 influenza viruses. We present examples of how this model can be used to study the dynamics of influenza epidemics in the United States and simulate how to mitigate or delay them using pharmaceutical interventions and social distancing measures. Computer simulation models play an essential role in informing public policy and evaluating pandemic preparedness plans. We have made the source code of this model publicly available to encourage its use and further development.

  2. Epidemic Spread of Symbiotic and Non-Symbiotic Bradyrhizobium Genotypes Across California.

    Science.gov (United States)

    Hollowell, A C; Regus, J U; Gano, K A; Bantay, R; Centeno, D; Pham, J; Lyu, J Y; Moore, D; Bernardo, A; Lopez, G; Patil, A; Patel, S; Lii, Y; Sachs, J L

    2016-04-01

    The patterns and drivers of bacterial strain dominance remain poorly understood in natural populations. Here, we cultured 1292 Bradyrhizobium isolates from symbiotic root nodules and the soil root interface of the host plant Acmispon strigosus across a >840-km transect in California. To investigate epidemiology and the potential role of accessory loci as epidemic drivers, isolates were genotyped at two chromosomal loci and were assayed for presence or absence of accessory "symbiosis island" loci that encode capacity to form nodules on hosts. We found that Bradyrhizobium populations were very diverse but dominated by few haplotypes-with a single "epidemic" haplotype constituting nearly 30 % of collected isolates and spreading nearly statewide. In many Bradyrhizobium lineages, we inferred presence and absence of the symbiosis island suggesting recurrent evolutionary gain and or loss of symbiotic capacity. We did not find statistical phylogenetic evidence that the symbiosis island acquisition promotes strain dominance and both symbiotic and non-symbiotic strains exhibited population dominance and spatial spread. Our dataset reveals that a strikingly few Bradyrhizobium genotypes can rapidly spread to dominate a landscape and suggests that these epidemics are not driven by the acquisition of accessory loci as occurs in key human pathogens.

  3. FluTE, a publicly available stochastic influenza epidemic simulation model.

    Science.gov (United States)

    Chao, Dennis L; Halloran, M Elizabeth; Obenchain, Valerie J; Longini, Ira M

    2010-01-29

    Mathematical and computer models of epidemics have contributed to our understanding of the spread of infectious disease and the measures needed to contain or mitigate them. To help prepare for future influenza seasonal epidemics or pandemics, we developed a new stochastic model of the spread of influenza across a large population. Individuals in this model have realistic social contact networks, and transmission and infections are based on the current state of knowledge of the natural history of influenza. The model has been calibrated so that outcomes are consistent with the 1957/1958 Asian A(H2N2) and 2009 pandemic A(H1N1) influenza viruses. We present examples of how this model can be used to study the dynamics of influenza epidemics in the United States and simulate how to mitigate or delay them using pharmaceutical interventions and social distancing measures. Computer simulation models play an essential role in informing public policy and evaluating pandemic preparedness plans. We have made the source code of this model publicly available to encourage its use and further development.

  4. Phylogenetic analysis of canine distemper virus in South America clade 1 reveals unique molecular signatures of the local epidemic.

    Science.gov (United States)

    Fischer, Cristine D B; Gräf, Tiago; Ikuta, Nilo; Lehmann, Fernanda K M; Passos, Daniel T; Makiejczuk, Aline; Silveira, Marcos A T; Fonseca, André S K; Canal, Cláudio W; Lunge, Vagner R

    2016-07-01

    Canine distemper virus (CDV) is a highly contagious pathogen for domestic dogs and several wild carnivore species. In Brazil, natural infection of CDV in dogs is very high due to the large non-vaccinated dog population, a scenario that calls for new studies on the molecular epidemiology. This study investigates the phylodynamics and amino-acid signatures of CDV epidemic in South America by analyzing a large dataset compiled from publicly available sequences and also by collecting new samples from Brazil. A population of 175 dogs with canine distemper (CD) signs was sampled, from which 89 were positive for CDV, generating 42 new CDV sequences. Phylogenetic analysis of the new and publicly available sequences revealed that Brazilian sequences mainly clustered in South America 1 (SA1) clade, which has its origin estimated to the late 1980's. The reconstruction of the demographic history in SA1 clade showed an epidemic expanding until the recent years, doubling in size every nine years. SA1 clade epidemic distinguished from the world CDV epidemic by the emergence of the R580Q strain, a very rare and potentially detrimental substitution in the viral genome. The R580Q substitution was estimated to have happened in one single evolutionary step in the epidemic history in SA1 clade, emerging shortly after introduction to the continent. Moreover, a high prevalence (11.9%) of the Y549H mutation was observed among the domestic dogs sampled here. This finding was associated (p<0.05) with outcome-death and higher frequency in mixed-breed dogs, the later being an indicator of a continuous exchange of CDV strains circulating among wild carnivores and domestic dogs. The results reported here highlight the diversity of the worldwide CDV epidemic and reveal local features that can be valuable for combating the disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Current Zika virus epidemiology and recent epidemics.

    Science.gov (United States)

    Ioos, S; Mallet, H-P; Leparc Goffart, I; Gauthier, V; Cardoso, T; Herida, M

    2014-07-01

    The Zika virus (ZIKV) is a mosquito-borne flavivirus (Aedes), similar to other arboviruses, first identified in Uganda in 1947. Few human cases were reported until 2007, when a Zika outbreak occurred in Yap, Micronesia, even though ZIKV activity had been reported in Africa and in Asia through virological surveillance and entomological studies. French Polynesia has recorded a large outbreak since October 2013. A great number of cases and some with neurological and autoimmune complications have been reported in a context of concurrent circulation of dengue viruses. The clinical presentation is a "dengue-like syndrome". Until the epidemic in French Polynesia, no severe ZIKV disease had been described so far. The diagnosis is confirmed by viral genome detection by genomic amplification (RT- PCR) and viral isolation. These two large outbreaks occurred in a previously unaffected area in less than a decade. They should raise awareness as to the potential for ZIKV to spread especially since this emergent disease is not well known and that some questions remain on potential reservoirs and transmission modes as well as on clinical presentations and complications. ZIKV has the potential to spread to new areas where the Aedes mosquito vector is present and could be a risk for Southern Europe. Strategies for the prevention and control of ZIKV disease should include the use of insect repellent and mosquito vector eradication. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. Diffusive epidemic process: theory and simulation

    International Nuclear Information System (INIS)

    Maia, Daniel Souza; Dickman, Ronald

    2007-01-01

    We study the continuous absorbing-state phase transition in the one-dimensional diffusive epidemic process via mean-field theory and Monte Carlo simulation. In this model, particles of two species (A and B) hop on a lattice and undergo reactions B → A and A+B → 2B; the total particle number is conserved. We formulate the model as a continuous-time Markov process described by a master equation. A phase transition between the (absorbing) B-free state and an active state is observed as the parameters (reaction and diffusion rates, and total particle density) are varied. Mean-field theory reveals a surprising, nonmonotonic dependence of the critical recovery rate on the diffusion rate of B particles. A computational realization of the process that is faithful to the transition rates defining the model is devised, allowing for direct comparison with theory. Using the quasi-stationary simulation method we determine the order parameter and the survival time in systems of up to 4000 sites. Due to strong finite-size effects, the results converge only for large system sizes. We find no evidence for a discontinuous transition. Our results are consistent with the existence of three distinct universality classes, depending on whether A particles diffusive more rapidly, less rapidly or at the same rate as B particles. We also perform quasi-stationary simulations of the triplet creation model, which yield results consistent with a discontinuous transition at high diffusion rates

  7. Spatially explicit modelling of cholera epidemics

    Science.gov (United States)

    Finger, F.; Bertuzzo, E.; Mari, L.; Knox, A. C.; Gatto, M.; Rinaldo, A.

    2013-12-01

    Epidemiological models can provide crucial understanding about the dynamics of infectious diseases. Possible applications range from real-time forecasting and allocation of health care resources to testing alternative intervention mechanisms such as vaccines, antibiotics or the improvement of sanitary conditions. We apply a spatially explicit model to the cholera epidemic that struck Haiti in October 2010 and is still ongoing. The dynamics of susceptibles as well as symptomatic and asymptomatic infectives are modelled at the scale of local human communities. Dissemination of Vibrio cholerae through hydrological transport and human mobility along the road network is explicitly taken into account, as well as the effect of rainfall as a driver of increasing disease incidence. The model is calibrated using a dataset of reported cholera cases. We further model the long term impact of several types of interventions on the disease dynamics by varying parameters appropriately. Key epidemiological mechanisms and parameters which affect the efficiency of treatments such as antibiotics are identified. Our results lead to conclusions about the influence of different intervention strategies on the overall epidemiological dynamics.

  8. Human enterovirus 71 epidemics: what's next?

    Science.gov (United States)

    Yip, Cyril C. Y.; Lau, Susanna K. P.; Woo, Patrick C. Y.; Yuen, Kwok-Yung

    2013-01-01

    Human enterovirus 71 (EV71) epidemics have affected various countries in the past 40 years. EV71 commonly causes hand, foot and mouth disease (HFMD) in children, but can result in neurological and cardiorespiratory complications in severe cases. Genotypic changes of EV71 have been observed in different places over time, with the emergence of novel genotypes or subgenotypes giving rise to serious outbreaks. Since the late 1990s, intra- and inter-typic recombination events in EV71 have been increasingly reported in the Asia-Pacific region. In particular, ‘double-recombinant’ EV71 strains belonging to a novel genotype D have been predominant in mainland China and Hong Kong over the last decade, though co-circulating with a minority of other EV71 subgenotypes and coxsackie A viruses. Continuous surveillance and genome studies are important to detect potential novel mutants or recombinants in the near future. Rapid and sensitive molecular detection of EV71 is of paramount importance in anticipating and combating EV71 outbreaks. PMID:24119538

  9. Nature's palette: the search for natural blue colorants.

    Science.gov (United States)

    Newsome, Andrew G; Culver, Catherine A; van Breemen, Richard B

    2014-07-16

    The food and beverage industry is seeking to broaden the palette of naturally derived colorants. Although considerable effort has been devoted to the search for new blue colorants in fruits and vegetables, less attention has been directed toward blue compounds from other sources such as bacteria and fungi. The current work reviews known organic blue compounds from natural plant, animal, fungal, and microbial sources. The scarcity of blue-colored metabolites in the natural world relative to metabolites of other colors is discussed, and structural trends common among natural blue compounds are identified. These compounds are grouped into seven structural classes and evaluated for their potential as new color additives.

  10. Bio-Activity and Dereplication-Based Discovery of Ophiobolins and Other Fungal Secondary Metabolites Targeting Leukemia Cells

    DEFF Research Database (Denmark)

    Bladt, Tanja Thorskov; Dürr, Claudia; Knudsen, Peter Boldsen

    2013-01-01

    The purpose of this study was to identify and characterize fungal natural products (NPs) with in vitro bioactivity towards leukemia cells. We based our screening on a combined analytical and bio-guided approach of LC-DAD-HRMS dereplication, explorative solid-phase extraction (E-SPE), and a co...

  11. Topology dependent epidemic spreading velocity in weighted networks

    International Nuclear Information System (INIS)

    Duan, Wei; Qiu, Xiaogang; Quax, Rick; Lees, Michael; Sloot, Peter M A

    2014-01-01

    Many diffusive processes occur on structured networks with weighted links, such as disease spread by airplane transport or information diffusion in social networks or blogs. Understanding the impact of weight-connectivity correlations on epidemic spreading in weighted networks is crucial to support decision-making on disease control and other diffusive processes. However, a real understanding of epidemic spreading velocity in weighted networks is still lacking. Here we conduct a numerical study of the velocity of a Reed–Frost epidemic spreading process in various weighted network topologies as a function of the correlations between edge weights and node degrees. We find that a positive weight-connectivity correlation leads to a faster epidemic spreading compared to an unweighted network. In contrast, we find that both uncorrelated and negatively correlated weight distributions lead to slower spreading processes. In the case of positive weight-connectivity correlations, the acceleration of spreading velocity is weak when the heterogeneity of weight distribution increases. (paper)

  12. Epidemic spreading in time-varying community networks

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Guangming, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xingyuan, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)

    2014-06-15

    The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q{sub c}. The epidemic will survive when q > q{sub c} and die when q < q{sub c}. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.

  13. Epidemic spread in bipartite network by considering risk awareness

    Science.gov (United States)

    Han, She; Sun, Mei; Ampimah, Benjamin Chris; Han, Dun

    2018-02-01

    Human awareness plays an important role in the spread of infectious diseases and the control of propagation patterns. Exploring the interplay between human awareness and epidemic spreading is a topic that has been receiving increasing attention. Considering the fact, some well-known diseases only spread between different species we propose a theoretical analysis of the Susceptible-Infected-Susceptible (SIS) epidemic spread from the perspective of bipartite network and risk aversion. Using mean field theory, the epidemic threshold is calculated theoretically. Simulation results are consistent with the proposed analytic model. The results show that, the final infection density is negative linear with the value of individuals' risk awareness. Therefore, the epidemic spread could be effectively suppressed by improving individuals' risk awareness.

  14. The effect of awareness on networked SIS epidemics

    KAUST Repository

    Paarporn, Keith; Eksin, Ceyhun; Weitz, Joshua S.; Shamma, Jeff S.

    2017-01-01

    the epidemic is currently prevalent. An agent's awareness is weighted from three sources of information: the fraction of infected neighbors in their contact network, their social network, and a global broadcast of the fraction of infected nodes in the entire

  15. Stochastic population and epidemic models persistence and extinction

    CERN Document Server

    Allen, Linda J S

    2015-01-01

    This monograph provides a summary of the basic theory of branching processes for single-type and multi-type processes. Classic examples of population and epidemic models illustrate the probability of population or epidemic extinction obtained from the theory of branching processes. The first chapter develops the branching process theory, while in the second chapter two applications to population and epidemic processes of single-type branching process theory are explored. The last two chapters present multi-type branching process applications to epidemic models, and then continuous-time and continuous-state branching processes with applications. In addition, several MATLAB programs for simulating stochastic sample paths  are provided in an Appendix. These notes originated as part of a lecture series on Stochastics in Biological Systems at the Mathematical Biosciences Institute in Ohio, USA. Professor Linda Allen is a Paul Whitfield Horn Professor of Mathematics in the Department of Mathematics and Statistics ...

  16. Drought and Epidemic Typhus, Central Mexico, 1655–1918

    Science.gov (United States)

    Acuna-Soto, Rudofo; Stahle, David W.

    2014-01-01

    Epidemic typhus is an infectious disease caused by the bacterium Rickettsia prowazekii and transmitted by body lice (Pediculus humanus corporis). This disease occurs where conditions are crowded and unsanitary. This disease accompanied war, famine, and poverty for centuries. Historical and proxy climate data indicate that drought was a major factor in the development of typhus epidemics in Mexico during 1655–1918. Evidence was found for 22 large typhus epidemics in central Mexico, and tree-ring chronologies were used to reconstruct moisture levels over central Mexico for the past 500 years. Below-average tree growth, reconstructed drought, and low crop yields occurred during 19 of these 22 typhus epidemics. Historical documents describe how drought created large numbers of environmental refugees that fled the famine-stricken countryside for food relief in towns. These refugees often ended up in improvised shelters in which crowding encouraged conditions necessary for spread of typhus. PMID:24564928

  17. [Hippocrates. Aphorisms and Epidemics III. Two clinical texts].

    Science.gov (United States)

    Frøland, Anders

    2015-01-01

    The two Hippocratic texts, Aphorisms and Epidemics III, have not been translated into Danish previously. The Aphorisms are 412 short, pithy statements, mostly on the prognosis in relation to certain symptoms in the course of the diseases, very often febrile. The Aphorisms begin with the famous words: "Life is short, the Art long, opportunity fleeting, experiment treacherous, judgment difficult." (Transl. W H S Jones [22]). Epidemics III consists of 28 case histories, again mostly of febrile patients, but also of observations on the connection of the seasons with general morbidity and mortality. The author describes an epidemic, which in some respects resembles Thucydides' report on the plague in Athens in 430 BC. It is suggested, that observations as have been recorded in the seven Hippocratic texts on epidemic diseases are the material on which prognostic statements as those collected in the Aphorisms are founded.

  18. 2,500-year Evolution of the Term Epidemic

    Science.gov (United States)

    Martin-Granel, Estelle

    2006-01-01

    The term epidemic (from the Greek epi [on] plus demos [people]), first used by Homer, took its medical meaning when Hippocrates used it as the title of one of his famous treatises. At that time, epidemic was the name given to a collection of clinical syndromes, such as coughs or diarrheas, occurring and propagating in a given period at a given location. Over centuries, the form and meaning of the term have changed. Successive epidemics of plague in the Middle Ages contributed to the definition of an epidemic as the propagation of a single, well-defined disease. The meaning of the term continued to evolve in the 19th-century era of microbiology. Its most recent semantic evolution dates from the last quarter of the 20th century, and this evolution is likely to continue in the future. PMID:16707055

  19. History of the HIV epidemic and response in Swaziland

    African Journals Online (AJOL)

    that self-stigma, multiple concurrent partnerships and short-term relationships, decision on condom use and ... This prevents MSM from seeking health services. To .... 90-90-90: An ambitious treatment target to help end the AIDS epidemic.

  20. Epidemic cholera in Latin America: spread and routes of transmission.

    Science.gov (United States)

    Guthmann, J P

    1995-12-01

    In the most recent epidemic of cholera in Latin America, nearly a million cases were reported and almost 9000 people died between January 1991 and December 1993. The epidemic spread rapidly from country to country, affecting in three years all the countries of Latin America except Uruguay and the Caribbean. Case-control studies carried out in Peru showed a significant association between drinking water and risk of disease. Cholera was associated with the consumption of unwashed fruit and vegetables, with eating food from street vendors and with contaminated crabmeat transported in travellers' luggage. This article documents the spread of the epidemic and its routes of transmission and discusses whether the introduction of the epidemic to Peru and its subsequent spread throughout the continent could have been prevented.