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Sample records for animal fungal pathogen

  1. Immunodetection of fungal and oomycete pathogens: established and emerging threats to human health, animal welfare and global food security.

    Science.gov (United States)

    Thornton, Christopher R; Wills, Odette E

    2015-02-01

    Filamentous fungi (moulds), yeast-like fungi, and oomycetes cause life-threatening infections of humans and animals and are a major constraint to global food security, constituting a significant economic burden to both agriculture and medicine. As well as causing localized or systemic infections, certain species are potent producers of allergens and toxins that exacerbate respiratory diseases or cause cancer and organ damage. We review the pathogenic and toxigenic organisms that are etiologic agents of both animal and plant diseases or that have recently emerged as serious pathogens of immunocompromised individuals. The use of hybridoma and phage display technologies and their success in generating monoclonal antibodies for the detection and control of fungal and oomycete pathogens are explored. Monoclonal antibodies hold enormous potential for the development of rapid and specific tests for the diagnosis of human mycoses, however, unlike plant pathology, their use in medical mycology remains to be fully exploited.

  2. Map kinases in fungal pathogens.

    Science.gov (United States)

    Xu, J R

    2000-12-01

    MAP kinases in eukaryotic cells are well known for transducing a variety of extracellular signals to regulate cell growth and differentiation. Recently, MAP kinases homologous to the yeast Fus3/Kss1 MAP kinases have been identified in several fungal pathogens and found to be important for appressorium formation, invasive hyphal growth, and fungal pathogenesis. This MAP kinase pathway also controls diverse growth or differentiation processes, including conidiation, conidial germination, and female fertility. MAP kinases homologous to yeast Slt2 and Hog1 have also been characterized in Candida albicans and Magnaporthe grisea. Mutants disrupted of the Slt2 homologues have weak cell walls, altered hyphal growth, and reduced virulence. The Hog1 homologues are dispensable for growth but are essential for regulating responses to hyperosmotic stress in C. albicans and M. grisea. Overall, recent studies have indicated that MAP kinase pathways may play important roles in regulating growth, differentiation, survival, and pathogenesis in fungal pathogens. PMID:11273677

  3. Proteomics of survival structures of fungal pathogens.

    Science.gov (United States)

    Loginov, Dmitry; Šebela, Marek

    2016-09-25

    Fungal pathogens are causal agents of numerous human, animal, and plant diseases. They employ various infection modes to overcome host defense systems. Infection mechanisms of different fungi have been subjected to many comprehensive studies. These investigations have been facilitated by the development of various '-omics' techniques, and proteomics has one of the leading roles in this regard. Fungal conidia and sclerotia could be considered the most important structures for pathogenesis as their germination is one of the first steps towards a host infection. They represent interesting objects for proteomic studies because of the presence of unique proteins with unexplored biotechnological potential required for pathogen viability, development and the subsequent host infection. Proteomic peculiarities of survival structures of different fungi, including those of biotechnological significance (e.g., Asperillus fumigatus, A. nidulans, Metarhizium anisopliae), in a dormant state, as well as changes in the protein production during early stages of fungal development are the subjects of the present review. We focused on biological aspects of proteomic studies of fungal survival structures rather than on an evaluation of proteomic approaches. For that reason, proteins that have been identified in this context are discussed from the point of view of their involvement in different biological processes and possible functions assigned to them. This is the first review paper summarizing recent advances in proteomics of fungal survival structures. PMID:26777984

  4. Evidence of threat to European economy and biodiversity following the introduction of an alien pathogen on the fungal-animal boundary.

    Science.gov (United States)

    Ercan, Didem; Andreou, Demetra; Sana, Salma; Öntaş, Canan; Baba, Esin; Top, Nildeniz; Karakuş, Uğur; Tarkan, Ali Serhan; Gozlan, Rodolphe Elie

    2015-01-01

    Recent years have seen a global and rapid resurgence of fungal diseases with direct impact on biodiversity and local extinctions of amphibian, coral, or bat populations. Despite similar evidence of population extinction in European fish populations and the associated risk of food aquaculture due to the emerging rosette agent Sphaerothecum destruens, an emerging infectious eukaryotic intracellular pathogen on the fungal-animal boundary, our understanding of current threats remained limited. Long-term monitoring of population decline for the 8-year post-introduction of the fungal pathogen was coupled with seasonal molecular analyses of the 18S rDNA and histological work of native fish species organs. A phylogenetic relationship between the existing EU and US strains using the ribosomal internal transcribed spacer sequences was also carried out. Here, we provide evidence that this emerging parasite has now been introduced via Pseudorasbora parva to sea bass farms, an industry that represents over 400 M€€ annually in a Mediterranean region that is already economically vulnerable. We also provide for the first time evidence linking S. destruens to disease and severe declines in International Union for Conservation of Nature threatened European endemic freshwater fishes (i.e. 80% to 90 % mortalities). Our findings are thus of major economic and conservation importance. PMID:26954992

  5. Innate Defense against Fungal Pathogens.

    Science.gov (United States)

    Drummond, Rebecca A; Gaffen, Sarah L; Hise, Amy G; Brown, Gordon D

    2014-11-10

    Human fungal infections have been on the rise in recent years and proved increasingly difficult to treat as a result of the lack of diagnostics, effective antifungal therapies, and vaccines. Most pathogenic fungi do not cause disease unless there is a disturbance in immune homeostasis, which can be caused by modern medical interventions, disease-induced immunosuppression, and naturally occurring human mutations. The innate immune system is well equipped to recognize and destroy pathogenic fungi through specialized cells expressing a broad range of pattern recognition receptors (PRRs). This review will outline the cells and PRRs required for effective antifungal immunity, with a special focus on the major antifungal cytokine IL-17 and recently characterized antifungal inflammasomes.

  6. Immunology of fungal infections: lessons learned from animal models.

    Science.gov (United States)

    Steele, Chad; Wormley, Floyd L

    2012-08-01

    The continuing AIDS epidemic coupled with increased usage of immunosuppressive drugs to prevent organ rejection or treat autoimmune diseases has resulted in an increase in individuals at risk for acquiring fungal diseases. These concerns highlight the need to elucidate mechanisms of inducing protective immune responses against fungal pathogens. Consequently, several experimental models of human mycoses have been developed to study these diseases. The availability of transgenic animal models allows for in-depth analysis of specific components, receptors, and signaling pathways that elicit protection against fungal diseases. This review focuses on recent advances in our understanding of immune responses to fungal infections gained using animal models.

  7. 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.

  8. Fungal quorum sensing molecules: Role in fungal morphogenesis and pathogenicity.

    Science.gov (United States)

    Wongsuk, Thanwa; Pumeesat, Potjaman; Luplertlop, Natthanej

    2016-05-01

    When microorganisms live together in high numbers, they need to communicate with each other. To achieve cell-cell communication, microorganisms secrete molecules called quorum-sensing molecules (QSMs) that control their biological activities and behaviors. Fungi secrete QSMs such as farnesol, tyrosol, phenylethanol, and tryptophol. The role of QSMs in fungi has been widely studied in both yeasts and filamentous fungi, for example in Candida albicans, C. dubliniensis, Aspergillus niger, A. nidulans, and Fusarium graminearum. QSMs impact fungal morphogenesis (yeast-to-hypha formation) and also play a role in the germination of macroconidia. QSMs cause fungal cells to initiate programmed cell death, or apoptosis, and play a role in fungal pathogenicity. Several types of QSMs are produced during stages of biofilm development to control cell population or morphology in biofilm communities. This review article emphasizes the role of fungal QSMs, especially in fungal morphogenesis, biofilm formation, and pathogenicity. Information about QSMs may lead to improved measures for controlling fungal infection. PMID:26972663

  9. TmpL, a transmembrane protein required for intracellular redox homeostasis and virulence in a plant and an animal fungal pathogen.

    Directory of Open Access Journals (Sweden)

    Kwang-Hyung Kim

    2009-11-01

    have discovered a novel protein involved in the virulence of both plant and animal fungal pathogens. Our results strongly suggest that dysregulation of oxidative stress homeostasis in the absence of TmpL is the underpinning cause of the developmental and virulence defects observed in these studies.

  10. Global distribution of two fungal pathogens threatening endangered sea turtles

    OpenAIRE

    Sarmiento-Ramírez, Jullie M.; Elena Abella-Pérez; Andrea D Phillott; Jolene Sim; Pieter van West; María P Martín; Adolfo Marco; Javier Diéguez-Uribeondo

    2014-01-01

    Nascent fungal infections are currently considered as one of the main threats for biodiversity and ecosystem health, and have driven several animal species into critical risk of extinction. Sea turtles are one of the most endangered groups of animals and only seven species have survived to date. Here, we described two pathogenic species, i.e., Fusarium falciforme and Fusarium keratoplasticum, that are globally distributed in major turtle nesting areas for six sea turtle species and that are i...

  11. Plant Fungal Pathogens: Methods and Protocols

    NARCIS (Netherlands)

    Bolton, M.D.; Thomma, B.P.H.J.

    2012-01-01

    Over the course of evolution, fungi have adapted to occupy specific niches, from symbiotically inhabiting the flora of the intestinal tract of mammals to saprophytic growth on leaf litter resting on the forest floor. In Plant Fungal Pathogens: Methods and Protocols, expert researchers in the field d

  12. Complement and fungal pathogens: an update.

    Science.gov (United States)

    Speth, Cornelia; Rambach, Günter; Würzner, Reinhard; Lass-Flörl, Cornelia

    2008-11-01

    Fungal infections are a serious complication in immunocompromised patients such as human immunodeficiency virus-infected individuals, patients with organ transplantations or with haematological neoplasia. The lethality of opportunistic fungal infection is high despite a growing arsenal of antimycotic drugs, implying the urgent need for supportive immunological therapies to strengthen the current inefficient antimicrobial defences of the immunocompromised host. Therefore, increasing effort has been directed to investigating the interplay between fungi and the host immunity and thus to find starting points for additional therapeutic approaches. In this article, we review the actual state of the art concerning the role of complement in the pathogenesis of fungal infections. Important aspects include the activation of the complement system by the fungal pathogen, the efficiency of the complement-associated antimicrobial functions and the arsenal of immune evasion strategies applied by the fungi. The twin functions of complement as an interactive player of the innate immunity and at the same time as a modulator of the adaptive immunity make this defence weapon a particularly interesting therapeutic candidate to mobilise a more effective immune response and to strengthen in one fell swoop a broad spectrum of different immune reactions. However, we also mention the 'Yin-Yang' nature of the complement system in fungal infections, as growing evidence assigns to complement a contributory part in the pathogenesis of fungus-induced allergic manifestations. PMID:18705662

  13. Pathogen protection and virulence: Dark side of fungal membrane protein revealed

    OpenAIRE

    Whyte, Barry James

    2009-01-01

    Researchers at the Virginia Bioinformatics Institute at Virginia Tech and Montana State University have discovered a fungal protein that plays a key role in causing disease in plants and animals and which also shields the pathogen from oxidative stress.

  14. Nitrosative and oxidative stress responses in fungal pathogenicity

    OpenAIRE

    Brown, Alistair JP; Haynes, Ken; Quinn, Janet

    2009-01-01

    Fungal pathogenicity has arisen in polyphyletic manner during evolution, yielding fungal pathogens with diverse infection strategies and with differing degrees of evolutionary adaptation to their human host. Not surprisingly, these fungal pathogens display differing degrees of resistance to the reactive oxygen and nitrogen species used by human cells to counteract infection. Furthermore, whilst evolutionarily conserved regulators, such as Hog1, are central to such stress responses in many fun...

  15. Population Genomics of Fungal and Oomycete Pathogens.

    Science.gov (United States)

    Grünwald, Niklaus J; McDonald, Bruce A; Milgroom, Michael G

    2016-08-01

    We are entering a new era in plant pathology in which whole-genome sequences of many individuals of a pathogen species are becoming readily available. Population genomics aims to discover genetic mechanisms underlying phenotypes associated with adaptive traits such as pathogenicity, virulence, fungicide resistance, and host specialization, as genome sequences or large numbers of single nucleotide polymorphisms become readily available from multiple individuals of the same species. This emerging field encompasses detailed genetic analyses of natural populations, comparative genomic analyses of closely related species, identification of genes under selection, and linkage analyses involving association studies in natural populations or segregating populations resulting from crosses. The era of pathogen population genomics will provide new opportunities and challenges, requiring new computational and analytical tools. This review focuses on conceptual and methodological issues as well as the approaches to answering questions in population genomics. The major steps start with defining relevant biological and evolutionary questions, followed by sampling, genotyping, and phenotyping, and ending in analytical methods and interpretations. We provide examples of recent applications of population genomics to fungal and oomycete plant pathogens. PMID:27296138

  16. Comparative genomic analysis of human fungal pathogens causing paracoccidioidomycosis.

    Directory of Open Access Journals (Sweden)

    Christopher A Desjardins

    2011-10-01

    Full Text Available Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18 and one strain of Paracoccidioides lutzii (Pb01. These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic

  17. Fungicide resistance assays for fungal plant pathogens.

    Science.gov (United States)

    Secor, Gary A; Rivera, Viviana V

    2012-01-01

    Fungicide resistance assays are useful to determine if a fungal pathogen has developed resistance to a fungicide used to manage the disease it causes. Laboratory assays are used to determine loss of sensitivity, or resistance, to a fungicide and can explain fungicide failures and for developing successful fungicide recommendations in the field. Laboratory assays for fungicide resistance are conducted by measuring reductions in growth or spore germination of fungi in the presence of fungicide, or by molecular procedures. This chapter describes two techniques for measuring fungicide resistance, using the sugarbeet leaf spot fungus Cercospora beticola as a model for the protocol. Two procedures are described for fungicides from two different classes; growth reduction for triazole (sterol demethylation inhibitor; DMI) fungicides, and inhibition of spore germination for quinone outside inhibitor (QoI) fungicides.

  18. The Top 10 fungal pathogens in molecular plant pathology

    NARCIS (Netherlands)

    Dean, R.; Kan, van J.A.L.; Pretorius, Z.A.; Hammond-Kosack, K.E.; Pietro, Di A.; Spanu, P.D.; Rudd, J.J.; Dickman, M.; Kahmann, R.; Ellis, J.; Foster, G.D.

    2012-01-01

    The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a ‘Top 10’ based on scientific/economic importance. The survey generated 495 votes from the international co

  19. Emerging Threats in Antifungal-Resistant Fungal Pathogens

    OpenAIRE

    Sanglard, Dominique

    2016-01-01

    The use of antifungal drugs in the therapy of fungal diseases can lead to the development of antifungal resistance. Resistance has been described for virtually all antifungal agents in diverse pathogens, including Candida and Aspergillus species. The majority of resistance mechanisms have also been elucidated at the molecular level in these pathogens. Drug resistance genes and genome mutations have been identified. Therapeutic choices are limited for the control of fungal diseases, and it is ...

  20. Higher plant diversity promotes higher diversity of fungal pathogens, while it decreases pathogen infection per plant

    OpenAIRE

    Rottstock, Tanja; Joshi, Jasmin; Kummer, Volker; Fischer, Markus

    2014-01-01

    Fungal plant pathogens are common in natural communities where they affect plant physiology, plant survival, and biomass production. Conversely, pathogen transmission and infection may be regulated by plant community characteristics such as plant species diversity and functional composition that favor pathogen diversity through increases in host diversity while simultaneously reducing pathogen infection via increased variability in host density and spatial heterogeneity. Therefore, a comprehe...

  1. Global distribution of two fungal pathogens threatening endangered sea turtles.

    Directory of Open Access Journals (Sweden)

    Jullie M Sarmiento-Ramírez

    Full Text Available Nascent fungal infections are currently considered as one of the main threats for biodiversity and ecosystem health, and have driven several animal species into critical risk of extinction. Sea turtles are one of the most endangered groups of animals and only seven species have survived to date. Here, we described two pathogenic species, i.e., Fusarium falciforme and Fusarium keratoplasticum, that are globally distributed in major turtle nesting areas for six sea turtle species and that are implicated in low hatch success. These two fungi possess key biological features that are similar to emerging pathogens leading to host extinction, e.g., high virulence, and a broad host range style of life. Their optimal growth temperature overlap with the optimal incubation temperature for eggs, and they are able to kill up to 90% of the embryos. Environmental forcing, e.g., tidal inundation and clay/silt content of nests, were correlated to disease development. Thus, these Fusarium species constitute a major threat to sea turtle nests, especially to those experiencing environmental stressors. These findings have serious implications for the survival of endangered sea turtle populations and the success of conservation programs worldwide.

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

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    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.

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

    Science.gov (United States)

    Gozlan, Rodolphe E; Marshall, Wyth L; Lilje, Osu; Jessop, Casey N; Gleason, Frank H; Andreou, Demetra

    2014-01-01

    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.

  4. Splash : the dispersal of fungal plant pathogens in rain events

    NARCIS (Netherlands)

    Pielaat, A.

    2000-01-01

    Models were developed to study splash dispersal of fungal plant pathogens in space and time. The models incorporate the main mechanisms involved in splash dispersal, that is 1. A raindrop hits the thin water film on the crop surface containing spores and spores are dispersed in the splashing rain dr

  5. Emerging fungal threats to animal, plant and ecosystem health.

    Science.gov (United States)

    Fisher, Matthew C; Henk, Daniel A; Briggs, Cheryl J; Brownstein, John S; Madoff, Lawrence C; McCraw, Sarah L; Gurr, Sarah J

    2012-04-12

    The past two decades have seen an increasing number of virulent infectious diseases in natural populations and managed landscapes. In both animals and plants, an unprecedented number of fungal and fungal-like diseases have recently caused some of the most severe die-offs and extinctions ever witnessed in wild species, and are jeopardizing food security. Human activity is intensifying fungal disease dispersal by modifying natural environments and thus creating new opportunities for evolution. We argue that nascent fungal infections will cause increasing attrition of biodiversity, with wider implications for human and ecosystem health, unless steps are taken to tighten biosecurity worldwide. PMID:22498624

  6. 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. PMID:24293285

  7. Effects of Ionizing Radiation on Postharvest Fungal Pathogens.

    Science.gov (United States)

    Jeong, Rae-Dong; Shin, Eun-Jung; Chu, Eun-Hee; Park, Hae-Jun

    2015-06-01

    Postharvest diseases cause losses in a wide variety of crops around the world. Irradiation, a useful nonchemical approach, has been used as an alternative treatment for fungicide to control plant fungal pathogens. For a preliminary study, ionizing radiations (gamma, X-ray, or e-beam irradiation) were evaluated for their antifungal activity against Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer through mycelial growth, spore germination, and morphological analysis under various conditions. Different fungi exhibited different radiosensitivity. The inhibition of fungal growth showed in a dose-dependent manner. Three fungal pathogens have greater sensitivity to the e-beam treatment compared to gamma or X-ray irradiations. The inactivation of individual fungal-viability to different irradiations can be considered between 3-4 kGy for B. cinerea and 1-2 kGy for P. expansum and R. stolonifer based on the radiosensitive and radio-resistant species, respectively. These preliminary data will provide critical information to control postharvest diseases through radiation. PMID:26060436

  8. Screening of endophytic bacteria against fungal plant pathogens.

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    Ohike, Tatsuya; Makuni, Kohei; Okanami, Masahiro; Ano, Takashi

    2013-12-01

    Bacterial endophytes were found from 6 plant leaves among 35 plant leaves screened. Two of the isolated bacteria showed antagonistic activity against fungal plant pathogens. An isolate named KL1 showed the clear inihibition against plant pathogens, Fusarium oxysporum and Rhizoctonia solani, on PDA as well as TSA plate. Supernatant of the bacterial culture also showed the clear inhibition against the fungal growth on the plate and the antibiotic substance was identified as iturin A by HPLC analysis. KL1 was identified as Bacillus sp. from the 16S rRNA gene analysis. Very thin hyphae of R. solani was miccroscopically observed when the fungus was co-cultivated with KL1. PMID:25078813

  9. Overview of Vertebrate Animal Models of Fungal Infection

    OpenAIRE

    Hohl, Tobias M

    2014-01-01

    Fungi represent emerging infectious threats to human populations worldwide. Mice and other laboratory animals have proved invaluable in modeling clinical syndromes associated with superficial and life-threatening invasive mycoses. This review outlines salient features of common vertebrate animal model systems to study fungal pathogenesis, host antifungal immune responses, and antifungal compounds.

  10. Neglected fungal zoonoses: Hidden threats to man and animals

    OpenAIRE

    Seyedmousavi, Seyedmojtaba; Guillot, J; Tolooe, Ali; Verweij, Paul; de Hoog, G. S.

    2015-01-01

    textabstractZoonotic fungi can be naturally transmitted between animals and humans, and in some cases cause significant public health problems. A number of mycoses associated with zoonotic transmission are among the group of the most common fungal diseases, worldwide. It is, however, notable that some fungal diseases with zoonotic potential have lacked adequate attention in international public health efforts, leading to insufficient attention on their preventive strategies. This review aims ...

  11. A fungal pathogen secretes plant alkalinizing peptides to increase infection.

    Science.gov (United States)

    Masachis, Sara; Segorbe, David; Turrà, David; Leon-Ruiz, Mercedes; Fürst, Ursula; El Ghalid, Mennat; Leonard, Guy; López-Berges, Manuel S; Richards, Thomas A; Felix, Georg; Di Pietro, Antonio

    2016-01-01

    Plant infections caused by fungi are often associated with an increase in the pH of the surrounding host tissue(1). Extracellular alkalinization is thought to contribute to fungal pathogenesis, but the underlying mechanisms are poorly understood. Here, we show that the root-infecting fungus Fusarium oxysporum uses a functional homologue of the plant regulatory peptide RALF (rapid alkalinization factor)(2,3) to induce alkalinization and cause disease in plants. An upshift in extracellular pH promotes infectious growth of Fusarium by stimulating phosphorylation of a conserved mitogen-activated protein kinase essential for pathogenicity(4,5). Fungal mutants lacking a functional Fusarium (F)-RALF peptide failed to induce host alkalinization and showed markedly reduced virulence in tomato plants, while eliciting a strong host immune response. Arabidopsis plants lacking the receptor-like kinase FERONIA, which mediates the RALF-triggered alkalinization response(6), displayed enhanced resistance against Fusarium. RALF homologues are found across a number of phylogenetically distant groups of fungi, many of which infect plants. We propose that fungal pathogens use functional homologues of alkalinizing peptides found in their host plants to increase their infectious potential and suppress host immunity. PMID:27572834

  12. Oxidative Stress Responses in the Human Fungal Pathogen, Candida albicans

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    Alessandra da Silva Dantas

    2015-02-01

    Full Text Available Candida albicans is a major fungal pathogen of humans, causing approximately 400,000 life-threatening systemic infections world-wide each year in severely immunocompromised patients. An important fungicidal mechanism employed by innate immune cells involves the generation of toxic reactive oxygen species (ROS, such as superoxide and hydrogen peroxide. Consequently, there is much interest in the strategies employed by C. albicans to evade the oxidative killing by macrophages and neutrophils. Our understanding of how C. albicans senses and responds to ROS has significantly increased in recent years. Key findings include the observations that hydrogen peroxide triggers the filamentation of this polymorphic fungus and that a superoxide dismutase enzyme with a novel mode of action is expressed at the cell surface of C. albicans. Furthermore, recent studies have indicated that combinations of the chemical stresses generated by phagocytes can actively prevent C. albicans oxidative stress responses through a mechanism termed the stress pathway interference. In this review, we present an up-date of our current understanding of the role and regulation of oxidative stress responses in this important human fungal pathogen.

  13. Direct exposure to animal enteric pathogens.

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    Enriquez, C; Nwachuku, N; Gerba, C P

    2001-01-01

    Humans have very close interactions with working, food-producing, and companion animals. According to the American Veterinary Medical Association, there are more than one hundred million cat and dog pets in the United States. Furthermore, non-traditional pets like reptiles and exotic birds are not unusual companion animals in households. In addition to sharing with animals our living and/or working space and time, we also share, unfortunately, many disease causing microorganisms. In the past few years, we have become aware that several enteric pathogens that were thought to be mostly restricted to animals are a major cause of human disease. Examples of such pathogens include the protozoan parasite Cryptosporidium parvum and bacteria such as Campylobacter spp. This review will examine the characteristics of zoonotic enteric pathogens including bacterial (Helicobacter spp., Campylobacter spp., Salmonella spp., and verotoxin-producing Escherichia coli); parasitic (Toxoplasma gondii, Giardia spp., Cryptosporidium spp.); and viral (rotavirus, norwalk-like virus, hepatitis E virus), and the status of our knowledge with regard to the impact of such pathogens on human health. PMID:11512628

  14. Functional genomics in the rice blast fungus to unravel the fungal pathogenicity

    Institute of Scientific and Technical Information of China (English)

    Junhyun JEON; Jaehyuk CHOI; Jongsun PARK; Yong-Hwan LEE

    2008-01-01

    A rapidly growing number of successful genome sequencing projects in plant pathogenic fungi greatly increase the demands for tools and methodologies to study fungal pathogenicity at genomic scale. Magnaporthe oryzae is an economically important plant pathogenic fungus whose genome is fully sequenced. Recently we have reported the development and application of functional genomics platform technologies in M. oryzae. This model approach would have many practical ramifications in design and implementation of upcoming functional genomics studies of filamentous fungi aimed at understanding fungal pathogenicity.

  15. Essential metals at the host-pathogen interface: nutritional immunity and micronutrient assimilation by human fungal pathogens.

    Science.gov (United States)

    Crawford, Aaron; Wilson, Duncan

    2015-11-01

    The ability of pathogenic microorganisms to assimilate sufficient nutrients for growth within their hosts is a fundamental requirement for pathogenicity. However, certain trace nutrients, including iron, zinc and manganese, are actively withheld from invading pathogens in a process called nutritional immunity. Therefore, successful pathogenic species must have evolved specialized mechanisms in order to adapt to the nutritionally restrictive environment of the host and cause disease. In this review, we discuss recent advances which have been made in our understanding of fungal iron and zinc acquisition strategies and nutritional immunity against fungal infections, and explore the mechanisms of micronutrient uptake by human pathogenic fungi.

  16. Convergent evolution of chromosomal sex-determining regions in the animal and fungal kingdoms.

    Directory of Open Access Journals (Sweden)

    James A Fraser

    2004-12-01

    Full Text Available Sexual identity is governed by sex chromosomes in plants and animals, and by mating type (MAT loci in fungi. Comparative analysis of the MAT locus from a species cluster of the human fungal pathogen Cryptococcus revealed sequential evolutionary events that fashioned this large, highly unusual region. We hypothesize that MAT evolved via four main steps, beginning with acquisition of genes into two unlinked sex-determining regions, forming independent gene clusters that then fused via chromosomal translocation. A transitional tripolar intermediate state then converted to a bipolar system via gene conversion or recombination between the linked and unlinked sex-determining regions. MAT was subsequently subjected to intra- and interallelic gene conversion and inversions that suppress recombination. These events resemble those that shaped mammalian sex chromosomes, illustrating convergent evolution in sex-determining structures in the animal and fungal kingdoms.

  17. Sporothrix schenckii complex biology: environment and fungal pathogenicity.

    Science.gov (United States)

    Téllez, M D; Batista-Duharte, A; Portuondo, D; Quinello, C; Bonne-Hernández, R; Carlos, I Z

    2014-11-01

    Sporothrix schenckii is a complex of various species of fungus found in soils, plants, decaying vegetables and other outdoor environments. It is the aetiological agent of sporotrichosis in humans and several animals. Humans and animals can acquire the disease through traumatic inoculation of the fungus into subcutaneous tissue. Despite the importance of sporotrichosis, it being currently regarded as an emergent disease in several countries, the factors driving its increasing medical importance are still largely unknown. There have only been a few studies addressing the influence of the environment on the virulence of these pathogens. However, recent studies have demonstrated that adverse conditions in its natural habitats can trigger the expression of different virulence factors that confer survival advantages both in animal hosts and in the environment. In this review, we provide updates on the important advances in the understanding of the biology of Spor. schenckii and the modification of its virulence linked to demonstrated or putative environmental factors.

  18. Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Nor’Aishah, E-mail: aishahnh@ns.uitm.edu.my [Faculty of Applied Science, UniversitiTeknologi MARA (UiTM), Kuala Pilah, Negeri Sembilan (Malaysia); Rafii, Mohd Y., E-mail: mrafii@upm.edu.my [Institute of Tropical Agriculture, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Department of Crop Science, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Rahim, Harun A. [Agrotechnology & Bioscience Division, Malaysian Nuclear Agency, Bangi, Kajang, Selangor (Malaysia); Ali, Nusaibah Syd [Department of Plant Protection, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Mazlan, Norida [Department of Agriculture Technology, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Abdullah, Shamsiah [Faculty of Plantation and Agrotechnology, UniversitiTeknologi MARA (UiTM), Shah Alam, Selangor (Malaysia)

    2016-02-01

    Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management.

  19. Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

    International Nuclear Information System (INIS)

    Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management

  20. Regulation of filamentation in the human fungal pathogen Candida tropicalis.

    Science.gov (United States)

    Zhang, Qiuyu; Tao, Li; Guan, Guobo; Yue, Huizhen; Liang, Weihong; Cao, Chengjun; Dai, Yu; Huang, Guanghua

    2016-02-01

    The yeast-filament transition is essential for the virulence of a variety of fungi that are pathogenic to humans. N-acetylglucosamine (GlcNAc) is a potent inducer of filamentation in Candida albicans and thermally dimorphic fungi such as Histoplasma capsulatum and Blastomyces dermatitidis. However, GlcNAc suppresses rather than promotes filamentation in Candida tropicalis, a fungal species that is closely related to C. albicans. Despite the intensive study in C. albicans, the regulatory mechanism of filamentation is poorly understood. In this study, we demonstrate that the cAMP signaling pathway plays a central role in the regulation of filamentation in C. tropicalis. By screening an overexpression library of 156 transcription factors, we have identified approximately 40 regulators of filamentous growth. Although most of the regulators (e.g., Tec1, Gat2, Nrg1, Sfl1, Sfl2 and Ash1) demonstrate a conserved role in the regulation of filamentation, similar to their homologues in C. albicans or Saccharomyces cerevisiae, a number of transcription factors (e.g., Wor1, Bcr1, Stp4, Efh1, Csr1 and Zcf17) play a specific role in C. tropicalis. Our findings indicate that multiple interconnected signaling pathways are involved in the regulation of filamentation in C. tropicalis. These mechanisms have conserved and divergent features among different Candida species. PMID:26466925

  1. Impact of Plant Oils as Antifungal Activity Against Fungal Pathogens of Cinnamomum Zeylanicum (Cinnamon)

    OpenAIRE

    Aisha Mohammed homod alrajhi

    2014-01-01

    Eleven fungal species were isolated from cinnamon plant, and two fungal genera could not be identified because they failed to sponulate in pure cultures. The identified species of fungi belonged to the genera Curvularia, Helminthosporium, Pestalotiopsis, Aspergillus, Rhizopus, Cladosporium, Nigrospora and Trichoderma.The effects of plant oils and synthetic fungicides were studied in a series of experiments against fungal pathogens of Cinnamon. The present results indicated a range of plant oi...

  2. 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 and their plan

  3. The general transcriptional repressor Tup1 is required for dimorphism and virulence in a fungal plant pathogen.

    Directory of Open Access Journals (Sweden)

    Alberto Elías-Villalobos

    2011-09-01

    Full Text Available A critical step in the life cycle of many fungal pathogens is the transition between yeast-like growth and the formation of filamentous structures, a process known as dimorphism. This morphological shift, typically triggered by multiple environmental signals, is tightly controlled by complex genetic pathways to ensure successful pathogenic development. In animal pathogenic fungi, one of the best known regulators of dimorphism is the general transcriptional repressor, Tup1. However, the role of Tup1 in fungal dimorphism is completely unknown in plant pathogens. Here we show that Tup1 plays a key role in orchestrating the yeast to hypha transition in the maize pathogen Ustilago maydis. Deletion of the tup1 gene causes a drastic reduction in the mating and filamentation capacity of the fungus, in turn leading to a reduced virulence phenotype. In U. maydis, these processes are controlled by the a and b mating-type loci, whose expression depends on the Prf1 transcription factor. Interestingly, Δtup1 strains show a critical reduction in the expression of prf1 and that of Prf1 target genes at both loci. Moreover, we observed that Tup1 appears to regulate Prf1 activity by controlling the expression of the prf1 transcriptional activators, rop1 and hap2. Additionally, we describe a putative novel prf1 repressor, named Pac2, which seems to be an important target of Tup1 in the control of dimorphism and virulence. Furthermore, we show that Tup1 is required for full pathogenic development since tup1 deletion mutants are unable to complete the sexual cycle. Our findings establish Tup1 as a key factor coordinating dimorphism in the phytopathogen U. maydis and support a conserved role for Tup1 in the control of hypha-specific genes among animal and plant fungal pathogens.

  4. Inhibition of citrus fungal pathogens by using lactic acid bacteria.

    Science.gov (United States)

    Gerez, C L; Carbajo, M S; Rollán, G; Torres Leal, G; Font de Valdez, G

    2010-08-01

    The effect of lactic acid bacteria (LAB) on pathogenic fungi was evaluated and the metabolites involved in the antifungal effect were characterized. Penicillium digitatum (INTA 1 to INTA 7) and Geotrichum citri-aurantii (INTA 8) isolated from decayed lemon from commercial packinghouses were treated with imazalil and guazatine to obtain strains resistant to these fungicides. The most resistant strains (4 fungal strains) were selected for evaluating the antifungal activity of 33 LAB strains, among which only 8 strains gave positive results. The antifungal activity of these LAB strains was related to the production of lactic acid, acetic acid, and phenyllactic acid (PLA). A central composite design and the response surface methodology were used to evaluate the inhibitory effect of the organic acids produced by the LAB cultures. The antifungal activity of lactic acid was directly related to its concentration; however, acetic acid and PLA showed a peak of activity at 52.5 and 0.8 mM, respectively, with inhibition rates similar to those obtained with Serenade((R)) (3.0 ppm) imazalil (50 ppm) and guazatine (50 ppm). Beyond the peak of activity, a reduction in effectiveness of both acetic acid and PLA was observed. Comparing the inhibition rate of the organic acids, PLA was about 66- and 600-fold more effective than acetic acid and lactic acid, respectively. This study presents evidences on the antifungal effect of selected LAB strains and their end products. Studies are currently being undertaken to evaluate the effectiveness in preventing postharvest diseases on citrus fruits. PMID:20722936

  5. Antifungal activity of different natural dyes against traditional products affected fungal pathogens

    Institute of Scientific and Technical Information of China (English)

    R Mari selvam; AJA Ranjit Singh; K Kalirajan

    2012-01-01

    Objective: In the present study to evaluate the anti fungal activity of natural dyes against traditional products affected fungal pathogens. Methods: Many traditional craft products affected fungal pathogens were isolated using potato dextrose agar medium. The isolated fungus were identified by morphological and microscopically characterization using Alexopolus manual. 50μl of Turmeric, Terminalli, Guava and Henna natural dyes were poured into the wells of the culture plates. If antifungal activity was present on the plates, it was indicated by an inhibition zone surrounding the well containing the natural dye. Result: At a dose level of 50μl of terminalli dye was able to inhibit the growth of all the fungi tested. The absorbance rate of natural dyes analyzed by UV Spectrophotometer. The absorbance rate is high in terminalli (2.266) and turmeric (2.255). Conclusions: Natural dyes were bound with traditional products to give good colour and good antimicrobial activity against isolated fungal pathogens.

  6. A fungal pathogen of amphibians, Batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages.

    Directory of Open Access Journals (Sweden)

    Penny F Langhammer

    Full Text Available Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd, have accelerated recently, given the pathogen's role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in artificial media for more than six years (JEL427-P39, and one recently thawed from cryopreserved stock (JEL427-P9. In a common garden experiment, we then exposed two different amphibian species, Eleutherodactylus coqui and Atelopus zeteki, to both cultures to test whether Bd attenuates in pathogenicity with in vitro passages. The culture with the shorter passage history, JEL427-P9, had significantly greater zoospore densities over time compared to JEL427-P39. This difference in zoospore production was associated with a difference in pathogenicity for a susceptible amphibian species, indicating that fecundity may be an important virulence factor for Bd. In the 130-day experiment, Atelopus zeteki frogs exposed to the JEL427-P9 culture experienced higher average infection intensity and 100% mortality, compared with 60% mortality for frogs exposed to JEL427-P39. This effect was not observed with Eleutherodactylus coqui, which was able to clear infection. We hypothesize that the differences in phenotypic performance observed with Atelopus zeteki are rooted in changes of the Bd genome. Future investigations enabled by this study will focus on the underlying mechanisms of Bd pathogenicity.

  7. A fungal pathogen of amphibians, Batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages.

    Science.gov (United States)

    Langhammer, Penny F; Lips, Karen R; Burrowes, Patricia A; Tunstall, Tate; Palmer, Crystal M; Collins, James P

    2013-01-01

    Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), have accelerated recently, given the pathogen's role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in artificial media for more than six years (JEL427-P39), and one recently thawed from cryopreserved stock (JEL427-P9). In a common garden experiment, we then exposed two different amphibian species, Eleutherodactylus coqui and Atelopus zeteki, to both cultures to test whether Bd attenuates in pathogenicity with in vitro passages. The culture with the shorter passage history, JEL427-P9, had significantly greater zoospore densities over time compared to JEL427-P39. This difference in zoospore production was associated with a difference in pathogenicity for a susceptible amphibian species, indicating that fecundity may be an important virulence factor for Bd. In the 130-day experiment, Atelopus zeteki frogs exposed to the JEL427-P9 culture experienced higher average infection intensity and 100% mortality, compared with 60% mortality for frogs exposed to JEL427-P39. This effect was not observed with Eleutherodactylus coqui, which was able to clear infection. We hypothesize that the differences in phenotypic performance observed with Atelopus zeteki are rooted in changes of the Bd genome. Future investigations enabled by this study will focus on the underlying mechanisms of Bd pathogenicity. PMID:24130895

  8. Exploiting amoeboid and non-vertebrate animal model systems to study the virulence of human pathogenic fungi.

    Directory of Open Access Journals (Sweden)

    Eleftherios Mylonakis

    2007-07-01

    Full Text Available Experiments with insects, protozoa, nematodes, and slime molds have recently come to the forefront in the study of host-fungal interactions. Many of the virulence factors required for pathogenicity in mammals are also important for fungal survival during interactions with non-vertebrate hosts, suggesting that fungal virulence may have evolved, and been maintained, as a countermeasure to environmental predation by amoebae and nematodes and other small non-vertebrates that feed on microorganisms. Host innate immune responses are also broadly conserved across many phyla. The study of the interaction between invertebrate model hosts and pathogenic fungi therefore provides insights into the mechanisms underlying pathogen virulence and host immunity, and complements the use of mammalian models by enabling whole-animal high throughput infection assays. This review aims to assist researchers in identifying appropriate invertebrate systems for the study of particular aspects of fungal pathogenesis.

  9. Indigenous arbuscular mycorrhizal fungal assemblages protect grassland host plants from pathogens.

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    Jeannine Wehner

    Full Text Available Plant roots can establish associations with neutral, beneficial and pathogenic groups of soil organisms. Although it has been recognized from the study of individual isolates that these associations are individually important for plant growth, little is known about interactions of whole assemblages of beneficial and pathogenic microorganisms associating with plants.We investigated the influence of an interaction between local arbuscular mycorrhizal (AM fungal and pathogenic/saprobic microbial assemblages on the growth of two different plant species from semi-arid grasslands in NE Germany (Mallnow near Berlin. In a greenhouse experiment each plant species was grown for six months in either sterile soil or in sterile soil with one of three different treatments: 1 an AM fungal spore fraction isolated from field soil from Mallnow; 2 a soil pathogen/saprobe fraction consisting of a microbial community prepared with field soil from Mallnow and; 3 the combined AM fungal and pathogen/saprobe fractions. While both plant species grew significantly larger in the presence of AM fungi, they responded negatively to the pathogen/saprobe treatment. For both plant species, we found evidence of pathogen protection effects provided by the AM fungal assemblages. These results indicate that interactions between assemblages of beneficial and pathogenic microorganisms can influence the growth of host plants, but that the magnitude of these effects is plant species-specific.

  10. Indigenous arbuscular mycorrhizal fungal assemblages protect grassland host plants from pathogens.

    Science.gov (United States)

    Wehner, Jeannine; Antunes, Pedro M; Powell, Jeff R; Caruso, Tancredi; Rillig, Matthias C

    2011-01-01

    Plant roots can establish associations with neutral, beneficial and pathogenic groups of soil organisms. Although it has been recognized from the study of individual isolates that these associations are individually important for plant growth, little is known about interactions of whole assemblages of beneficial and pathogenic microorganisms associating with plants.We investigated the influence of an interaction between local arbuscular mycorrhizal (AM) fungal and pathogenic/saprobic microbial assemblages on the growth of two different plant species from semi-arid grasslands in NE Germany (Mallnow near Berlin). In a greenhouse experiment each plant species was grown for six months in either sterile soil or in sterile soil with one of three different treatments: 1) an AM fungal spore fraction isolated from field soil from Mallnow; 2) a soil pathogen/saprobe fraction consisting of a microbial community prepared with field soil from Mallnow and; 3) the combined AM fungal and pathogen/saprobe fractions. While both plant species grew significantly larger in the presence of AM fungi, they responded negatively to the pathogen/saprobe treatment. For both plant species, we found evidence of pathogen protection effects provided by the AM fungal assemblages. These results indicate that interactions between assemblages of beneficial and pathogenic microorganisms can influence the growth of host plants, but that the magnitude of these effects is plant species-specific. PMID:22110635

  11. Stress Response and Pathogenicity of the Necrotrophic Fungal Pathogen Alternaria alternata

    Directory of Open Access Journals (Sweden)

    Kuang-Ren Chung

    2012-01-01

    Full Text Available The production of host-selective toxins by the necrotrophic fungus Alternaria alternata is essential for the pathogenesis. A. alternata infection in citrus leaves induces rapid lipid peroxidation, accumulation of hydrogen peroxide (H2O2, and cell death. The mechanisms by which A. alternata avoids killing by reactive oxygen species (ROS after invasion have begun to be elucidated. The ability to coordinate of signaling pathways is essential for the detoxification of cellular stresses induced by ROS and for pathogenicity in A. alternata. A low level of H2O2, produced by the NADPH oxidase (NOX complex, modulates ROS resistance and triggers conidiation partially via regulating the redox-responsive regulators (YAP1 and SKN7 and the mitogen-activated protein (MAP kinase (HOG1 mediated pathways, which subsequently regulate the genes required for the biosynthesis of siderophore, an iron-chelating compound. Siderophore-mediated iron acquisition plays a key role in ROS detoxification because of the requirement of iron for the activities of antioxidants (e.g., catalase and SOD. Fungal strains impaired for the ROS-detoxifying system severely reduce the virulence on susceptible citrus cultivars. This paper summarizes the current state of knowledge of signaling pathways associated with cellular responses to multidrugs, oxidative and osmotic stress, and fungicides, as well as the pathogenicity/virulence in the tangerine pathotype of A. alternata.

  12. Arboviruses pathogenic for domestic and wild animals.

    Science.gov (United States)

    Hubálek, Zdenek; Rudolf, Ivo; Nowotny, Norbert

    2014-01-01

    The objective of this chapter is to provide an updated and concise systematic review on taxonomy, history, arthropod vectors, vertebrate hosts, animal disease, and geographic distribution of all arboviruses known to date to cause disease in homeotherm (endotherm) vertebrates, except those affecting exclusively man. Fifty arboviruses pathogenic for animals have been documented worldwide, belonging to seven families: Togaviridae (mosquito-borne Eastern, Western, and Venezuelan equine encephalilitis viruses; Sindbis, Middelburg, Getah, and Semliki Forest viruses), Flaviviridae (mosquito-borne yellow fever, Japanese encephalitis, Murray Valley encephalitis, West Nile, Usutu, Israel turkey meningoencephalitis, Tembusu and Wesselsbron viruses; tick-borne encephalitis, louping ill, Omsk hemorrhagic fever, Kyasanur Forest disease, and Tyuleniy viruses), Bunyaviridae (tick-borne Nairobi sheep disease, Soldado, and Bhanja viruses; mosquito-borne Rift Valley fever, La Crosse, Snowshoe hare, and Cache Valley viruses; biting midges-borne Main Drain, Akabane, Aino, Shuni, and Schmallenberg viruses), Reoviridae (biting midges-borne African horse sickness, Kasba, bluetongue, epizootic hemorrhagic disease of deer, Ibaraki, equine encephalosis, Peruvian horse sickness, and Yunnan viruses), Rhabdoviridae (sandfly/mosquito-borne bovine ephemeral fever, vesicular stomatitis-Indiana, vesicular stomatitis-New Jersey, vesicular stomatitis-Alagoas, and Coccal viruses), Orthomyxoviridae (tick-borne Thogoto virus), and Asfarviridae (tick-borne African swine fever virus). They are transmitted to animals by five groups of hematophagous arthropods of the subphyllum Chelicerata (order Acarina, families Ixodidae and Argasidae-ticks) or members of the class Insecta: mosquitoes (family Culicidae); biting midges (family Ceratopogonidae); sandflies (subfamily Phlebotominae); and cimicid bugs (family Cimicidae). Arboviral diseases in endotherm animals may therefore be classified as: tick

  13. Novel insights into host-fungal pathogen interactions derived from live-cell imaging.

    Science.gov (United States)

    Bain, Judith; Gow, Neil A R; Erwig, Lars-Peter

    2015-03-01

    The theoretical physicist and Nobel laureate Richard Feynman outlined in his 1959 lecture, "There's plenty of room at the bottom", the enormous possibility of producing and visualising things at smaller scales. The advent of advanced scanning and transmission electron microscopy and high-resolution microscopy has begun to open the door to visualise host-pathogen interactions at smaller scales, and spinning disc confocal and two-photon microscopy has improved our ability to study these events in real time in three dimensions. The aim of this review is to illustrate some of the advances in understanding host-fungal interactions that have been made in recent years in particular those relating to the interactions of live fungal pathogens with phagocytes. Dynamic imaging of host-pathogen interactions has recently revealed novel detail and unsuspected mechanistic insights, facilitating the dissection of the phagocytic process into its component parts. Here, we will highlight advances in our knowledge of host-fungal pathogen interactions, including the specific effects of fungal cell viability, cell wall composition and morphogenesis on the phagocytic process and try to define the relative contributions of neutrophils and macrophages to the clearance of fungal pathogens in vitro and the infected host.

  14. Bat white-nose syndrome: An emerging fungal pathogen?

    Science.gov (United States)

    Blehert, D.S.; Hicks, A.C.; Behr, M.; Meteyer, C.U.; Berlowski-Zier, B. M.; Buckles, E.L.; Coleman, J.T.H.; Darling, S.R.; Gargas, A.; Niver, R.; Okoniewski, J.C.; Rudd, R.J.; Stone, W.B.

    2009-01-01

    White-nose syndrome (WNS) is a condition associated with an unprecedented bat mortality event in the northeastern United States. Since the winter of 2006*2007, bat declines exceeding 75% have been observed at surveyed hibernacula. Affected bats often present with visually striking white fungal growth on their muzzles, ears, and/or wing membranes. Direct microscopy and culture analyses demonstrated that the skin of WNS-affected bats is colonized by a psychro-philic fungus that is phylogenetically related to Geomyces spp. but with a conidial morphology distinct from characterized members of this genus. This report characterizes the cutaneous fungal infection associated with WNS.

  15. Development of a Selective Medium for the Fungal Pathogen Fusarium graminearum Using Toxoflavin Produced by the Bacterial Pathogen Burkholderia glumae

    Directory of Open Access Journals (Sweden)

    Boknam Jung

    2013-12-01

    Full Text Available The ascomycete fungus Fusarium graminearum is a major causal agent for Fusarium head blight in cereals and produces mycotoxins such as trichothecenes and zearalenone. Isolation of the fungal strains from air or cereals can be hampered by various other airborne fungal pathogens and saprophytic fungi. In this study, we developed a selective medium specific to F. graminearum using toxoflavin produced by the bacterial pathogen Burkholderia glumae. F. graminearum was resistant to toxoflavin, while other fungi were sensitive to this toxin. Supplementing toxoflavin into medium enhanced the isolation of F. graminearum from rice grains by suppressing the growth of saprophytic fungal species. In addition, a medium with or without toxoflavin exposed to wheat fields for 1 h had 84% or 25%, respectively, of colonies identified as F. graminearum. This selection medium provides an efficient tool for isolating F. graminearum, and can be adopted by research groups working on genetics and disease forecasting.

  16. Adhesins in Human Fungal Pathogens : Glue with Plenty of Stick

    NARCIS (Netherlands)

    de Groot, Piet W. J.; Bader, Oliver; de Boer, Albert D.; Weig, Michael; Chauhan, Neeraj

    2013-01-01

    Understanding the pathogenesis of an infectious disease is critical for developing new methods to prevent infection and diagnose or cure disease. Adherence of microorganisms to host tissue is a prerequisite for tissue invasion and infection. Fungal cell wall adhesins involved in adherence to host ti

  17. Determination of fungal pathogens of common weed species in the vicinity of Tokat, Turkey.

    Science.gov (United States)

    Kadioğlu, I; Karamanli, N; Yanar, Y

    2010-01-01

    This study was carried out to determine the fungal pathogens on Chenopodium album L., Cirsium arvense (L.) Scop., Convolvulus arvensis L., Cynodon dactylon (L.) Pers., Delphinium consolida L., Portulaca oleracea L., Rumex crispus L., Solanum nigrum L., Sorghum halepense (L.) Pers. and Xanthium strumarium L. which were common weed species of agricultural areas. Surveys were conducted in May-June and August-September in 2004-2005 growing seasons. During the surveys density and frequency of the above mentioned weed species were also determined and number of infected plants was counted in each sampling area. Infected weed samples were collected from each sampling point and brought to the laboratory in polyethylene bags and the pathogens were identified at genus or species level. As a result of two year surveys, ten fungal pathogens were determined on eight weed species. The most important fungal pathogens determined on common weed species were as follow; Peronospora farinosa (Fr.) Fr. on C. album, and Septoria convolvuli DC., Erysiphe convolvuli DC., and Puccinia punctiformis (Strauss) Roehrl. on C. arvensis. These fungal diseases were observed mainly on the weeds located at the borders of fields. Infection rates of these pathogens reached up to 21.2% in some of the survey areas. Further studies should be conducted to evaluate the efficacy of these pathogen under in vitro and in vivo conditions.

  18. Determination of fungal pathogens of common weed species in the vicinity of Tokat, Turkey.

    Science.gov (United States)

    Kadioğlu, I; Karamanli, N; Yanar, Y

    2010-01-01

    This study was carried out to determine the fungal pathogens on Chenopodium album L., Cirsium arvense (L.) Scop., Convolvulus arvensis L., Cynodon dactylon (L.) Pers., Delphinium consolida L., Portulaca oleracea L., Rumex crispus L., Solanum nigrum L., Sorghum halepense (L.) Pers. and Xanthium strumarium L. which were common weed species of agricultural areas. Surveys were conducted in May-June and August-September in 2004-2005 growing seasons. During the surveys density and frequency of the above mentioned weed species were also determined and number of infected plants was counted in each sampling area. Infected weed samples were collected from each sampling point and brought to the laboratory in polyethylene bags and the pathogens were identified at genus or species level. As a result of two year surveys, ten fungal pathogens were determined on eight weed species. The most important fungal pathogens determined on common weed species were as follow; Peronospora farinosa (Fr.) Fr. on C. album, and Septoria convolvuli DC., Erysiphe convolvuli DC., and Puccinia punctiformis (Strauss) Roehrl. on C. arvensis. These fungal diseases were observed mainly on the weeds located at the borders of fields. Infection rates of these pathogens reached up to 21.2% in some of the survey areas. Further studies should be conducted to evaluate the efficacy of these pathogen under in vitro and in vivo conditions. PMID:21542473

  19. Modelling the regulation of thermal adaptation in Candida albicans, a major fungal pathogen of humans.

    Directory of Open Access Journals (Sweden)

    Michelle D Leach

    Full Text Available Eukaryotic cells have evolved mechanisms to sense and adapt to dynamic environmental changes. Adaptation to thermal insults, in particular, is essential for their survival. The major fungal pathogen of humans, Candida albicans, is obligately associated with warm-blooded animals and hence occupies thermally buffered niches. Yet during its evolution in the host it has retained a bona fide heat shock response whilst other stress responses have diverged significantly. Furthermore the heat shock response is essential for the virulence of C. albicans. With a view to understanding the relevance of this response to infection we have explored the dynamic regulation of thermal adaptation using an integrative systems biology approach. Our mathematical model of thermal regulation, which has been validated experimentally in C. albicans, describes the dynamic autoregulation of the heat shock transcription factor Hsf1 and the essential chaperone protein Hsp90. We have used this model to show that the thermal adaptation system displays perfect adaptation, that it retains a transient molecular memory, and that Hsf1 is activated during thermal transitions that mimic fever. In addition to providing explanations for the evolutionary conservation of the heat shock response in this pathogen and the relevant of this response to infection, our model provides a platform for the analysis of thermal adaptation in other eukaryotic cells.

  20. Aerially transmitted human fungal pathogens: what can we learn from metagenomics and comparative genomics?

    Science.gov (United States)

    Aliouat-Denis, Cécile-Marie; Chabé, Magali; Delhaes, Laurence; Dei-Cas, Eduardo

    2014-01-01

    In the last few decades, aerially transmitted human fungal pathogens have been increasingly recognized to impact the clinical course of chronic pulmonary diseases, such as asthma, cystic fibrosis or chronic obstructive pulmonary disease. Thanks to recent development of culture-free high-throughput sequencing methods, the metagenomic approaches are now appropriate to detect, identify and even quantify prokaryotic or eukaryotic microorganism communities inhabiting human respiratory tract and to access the complexity of even low-burden microbe communities that are likely to play a role in chronic pulmonary diseases. In this review, we explore how metagenomics and comparative genomics studies can alleviate fungal culture bottlenecks, improve our knowledge about fungal biology, lift the veil on cross-talks between host lung and fungal microbiota, and gain insights into the pathogenic impact of these aerially transmitted fungi that affect human beings. We reviewed metagenomic studies and comparative genomic analyses of carefully chosen microorganisms, and confirmed the usefulness of such approaches to better delineate biology and pathogenesis of aerially transmitted human fungal pathogens. Efforts to generate and efficiently analyze the enormous amount of data produced by such novel approaches have to be pursued, and will potentially provide the patients suffering from chronic pulmonary diseases with a better management. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

  1. Analysis of a food-borne fungal pathogen outbreak: virulence and genome of a Mucor circinelloides isolate from yogurt.

    Science.gov (United States)

    Lee, Soo Chan; Billmyre, R Blake; Li, Alicia; Carson, Sandra; Sykes, Sean M; Huh, Eun Young; Mieczkowski, Piotr; Ko, Dennis C; Cuomo, Christina A; Heitman, Joseph

    2014-01-01

    . circinelloides, a mucoralean fungal pathogen, and >200 consumers complained of symptoms, including vomiting, nausea, and diarrhea. The manufacturer voluntarily withdrew the affected yogurt products from the market. Compared to other food-borne pathogens, including bacteria, viruses, and parasites, less focus has been placed on the risk of fungal pathogens. This study evaluates the potential risk from the food-borne fungal pathogen M. circinelloides that was isolated from the contaminated commercial yogurt. We successfully cultured an M. circinelloides isolate and found that the isolate belongs to the species M. circinelloides f. circinelloides, which is often associated with human infections. In murine and insect host models, the isolate was virulent. While information disseminated in the popular press would suggest this fungal contaminant poses little or no risk to consumers, our results show instead that it is capable of causing significant infections in animals.

  2. Field tolerance to fungal pathogens of Brassica napus constitutively expressing a chimeric chitinase gene

    Energy Technology Data Exchange (ETDEWEB)

    Grison, R.; Grezes-Besset, B.; Lucante, N. [Rustica Prograin Genetique, Mondonville (France)] [and others

    1996-05-01

    Constitutive overexpression of a protein involved in plant defense mechanisms to disease is one of the strategies proposed to increase plant tolerance to fungal pathogens. A hybrid endochitinase gene under a constitutive promoter was introduced by Agrobacterium-mediated transformation into a winter-type oilseed rape (Brassica napus var. oleifera) inbred line. Progeny from transformed plants was challenged using three different fungal pathogens (Cylindrosporium concentricum, Phoma lingam, Sclerotinia sclerotiorum) in field trials at two different geographical locations. These plants exhibited an increased tolerance to disease as compared with the nontransgenic parental plants. 31 refs., 1 fig., 2 tabs.

  3. Role of Phospholipases in Fungal Fitness, Pathogenicity and Drug Development- Lessons from Cryptococcus neoformans

    Directory of Open Access Journals (Sweden)

    Julianne eDjordjevic

    2010-11-01

    Full Text Available Many pathogenic microbes, including many fungi, produce phospholipases which facilitate survival of the pathogen in vivo, invasion and dissemination throughout the host, expression of virulence traits and evasion of host immune defense mechanisms. These phospholipases are either secreted or produced intracellularly and act by physically disrupting host membranes, and/or by affecting fungal cell signaling and production of immunomodulatory effectors. Many of the secreted phospholipases acquire a glycosylphosphatidylinositol (GPI sorting motif to facilitate membrane and/or cell wall association and secretion. This review focuses primarily on the role of two members of the phospholipase enzyme family, phospholipase B (Plb and phosphatidylinositol (PI-specific phospholipase C (PI-PLC/Plc, in fungal pathogenesis and in particular, what has been learnt about their function from studies performed in the model pathogenic yeast, Cryptococcus neoformans. These studies have revealed how Plb has adapted to become an important part of the virulence repertoire of pathogenic fungi and how its secretion is regulated. They have also provided valuable insight into how the intracellular enzyme, Plc1, contributes to fungal fitness and pathogenicity - via a putative role in signal transduction pathways that regulate the production of stress-protecting pigments, polysaccharide capsule, cell wall integrity and adaptation to growth at host temperature. Finally, this review will address the role fungal phospholipases have played in the development of a new class of antifungal drugs, which mimic their phospholipid substrates.

  4. Fungal pathogens - a sweet and sour treat for toll-like receptors

    Directory of Open Access Journals (Sweden)

    Christelle eBourgeois

    2012-11-01

    Full Text Available Hundred-thousands of fungal species are present in our environment, including normal colonizers that constitute part of the human microbiota. The homeostasis of host-fungus interactions encompasses efficient fungal sensing, tolerance at mucosal surfaces, as well as antifungal defenses. Decrease in host immune fitness or increase in fungal burden may favor pathologies, ranging from superficial mucocutaneous diseases to invasive life-threatening fungal infections. Toll-like receptors (TLRs are essential players in this balance, due to their ability to control both inflammatory and anti-inflammatory processes upon recognition of fungal-specific pathogen-associated molecular patterns (PAMPs. Certain members of the TLR family participate to the initial recognition of fungal PAMPs on the cell surface, as well as inside phagosomes of innate immune cells. Active signaling cascades in phagocytes ultimately enable fungus clearance and the release of cytokines that shape and instruct other innate immune cells and the adaptive immune system. Some TLRs cooperate with other pattern recognition receptors (e.g., C-type lectins, Galectins, thus allowing for a tailored immune response. The spatio-temporal and physiological contributions of individual TLRs in fungal infections remains ill-defined, although in humans, TLR gene polymorphisms have been linked to increased susceptibility to fungal infections. This review focuses entirely on the role of TLRs that control the host susceptibility to environmental fungi (e.g., Aspergillus, Cryptoccocus, Coccidoides, as well as to the most frequent human fungal pathogens represented by the commensal Candida species. The emerging roles of TLRs in modulating host tolerance to fungi, and the strategies that evolved in some of these fungi to evade or use TLR recognition to their advantage will also be discussed, as well as their potential suitability as targets in vaccine therapies.

  5. The homeodomain transcription factor Ste12: Connecting fungal MAPK signalling to plant pathogenicity

    OpenAIRE

    Rispail, Nicolas; Pietro, A. D.

    2010-01-01

    A conserved mitogen-activated protein kinase (MAPK) cascade orthologous to the mating/filamentation MAPK pathway in yeast is required for fungal pathogenicity on plants. One of the key targets of this signaling pathway is the homeodomain transcription factor Ste12. Mutational analysis of ste12 orthologues in a variety of plant pathogenic fungi suggests that Ste12 functions as a master regulator of invasive growth. In this mini-review we highlight recent progress in understanding the role of S...

  6. Genome Sequencing and Comparative Genomics Analysis Revealed Pathogenic Potential in Penicillium capsulatum as a Novel Fungal Pathogen Belonging to Eurotiales

    Science.gov (United States)

    Yang, Ying; Chen, Min; Li, Zongwei; Al-Hatmi, Abdullah M. S.; de Hoog, Sybren; Pan, Weihua; Ye, Qiang; Bo, Xiaochen; Li, Zhen; Wang, Shengqi; Wang, Junzhi; Chen, Huipeng; Liao, Wanqing

    2016-01-01

    Penicillium capsulatum is a rare Penicillium species used in paper manufacturing, but recently it has been reported to cause invasive infection. To research the pathogenicity of the clinical Penicillium strain, we sequenced the genomes and transcriptomes of the clinical and environmental strains of P. capsulatum. Comparative analyses of these two P. capsulatum strains and close related strains belonging to Eurotiales were performed. The assembled genome sizes of P. capsulatum are approximately 34.4 Mbp in length and encode 11,080 predicted genes. The different isolates of P. capsulatum are highly similar, with the exception of several unique genes, INDELs or SNPs in the genes coding for glycosyl hydrolases, amino acid transporters and circumsporozoite protein. A phylogenomic analysis was performed based on the whole genome data of 38 strains belonging to Eurotiales. By comparing the whole genome sequences and the virulence-related genes from 20 important related species, including fungal pathogens and non-human pathogens belonging to Eurotiales, we found meaningful pathogenicity characteristics between P. capsulatum and its closely related species. Our research indicated that P. capsulatum may be a neglected opportunistic pathogen. This study is beneficial for mycologists, geneticists and epidemiologists to achieve a deeper understanding of the genetic basis of the role of P. capsulatum as a newly reported fungal pathogen. PMID:27761131

  7. Regulation of secondary metabolite production in the fungal tomato pathogen Cladosporium fulvum

    NARCIS (Netherlands)

    Griffiths, S.A.; Saccomanno, B.; Wit, de P.J.G.M.; Collemare, J.

    2015-01-01

    Cladosporium fulvum is a non-obligate biotrophic fungal tomato pathogen for which fifteen secondary metabolite (SM) gene clusters were previously identified in its genome. However, most of these SM biosynthetic pathways remain cryptic during growth in planta and in different in vitro conditions. The

  8. Targeted Gene Replacement in Fungal Pathogens via Agrobacterium tumefaciens- Mediated Transformation

    DEFF Research Database (Denmark)

    Frandsen, Rasmus John Normand; Frandsen, Mette; Giese, Nanna Henriette

    2012-01-01

    Genome sequence data on fungal pathogens provide the opportunity to carry out a reverse genetics approach to uncover gene function. Efficient methods for targeted genome modifications such as knockout and in locus over-expression are in high demand. Here we describe two efficient single-step clon...

  9. A critical role of autophagy in plant resistance to necrotrophic fungal pathogens.

    Science.gov (United States)

    Lai, Zhibing; Wang, Fei; Zheng, Zuyu; Fan, Baofang; Chen, Zhixiang

    2011-06-01

    Autophagy is a pathway for degradation of cytoplasmic components. In plants, autophagy plays an important role in nutrient recycling during nitrogen or carbon starvation, and in responses to abiotic stress. Autophagy also regulates age- and immunity-related programmed cell death, which is important in plant defense against biotrophic pathogens. Here we show that autophagy plays a critical role in plant resistance to necrotrophic pathogens. ATG18a, a critical autophagy protein in Arabidopsis, interacts with WRKY33, a transcription factor that is required for resistance to necrotrophic pathogens. Expression of autophagy genes and formation of autophagosomes are induced in Arabidopsis by the necrotrophic fungal pathogen Botrytis cinerea. Induction of ATG18a and autophagy by B. cinerea was compromised in the wrky33 mutant, which is highly susceptible to necrotrophic pathogens. Arabidopsis mutants defective in autophagy exhibit enhanced susceptibility to the necrotrophic fungal pathogens B. cinerea and Alternaria brassicicola based on increased pathogen growth in the mutants. The hypersusceptibility of the autophagy mutants was associated with reduced expression of the jasmonate-regulated PFD1.2 gene, accelerated development of senescence-like chlorotic symptoms, and increased protein degradation in infected plant tissues. These results strongly suggest that autophagy cooperates with jasmonate- and WRKY33-mediated signaling pathways in the regulation of plant defense responses to necrotrophic pathogens.

  10. Modelling animal waste pathogen transport from agricultural land to streams

    International Nuclear Information System (INIS)

    The transport of animal waste pathogens from crop land to streams can potentially elevate pathogen levels in stream water. Applying animal manure into crop land as fertilizers is a common practice in developing as well as in developed countries. Manure application into the crop land, however, can cause potential human health. To control pathogen levels in ambient water bodies such as streams, improving our understanding of pathogen transport at farm scale as well as at watershed scale is required. To understand the impacts of crop land receiving animal waste as fertilizers on stream's pathogen levels, here we investigate pathogen indicator transport at watershed scale. We exploited watershed scale hydrological model to estimate the transport of pathogens from the crop land to streams. Pathogen indicator levels (i.e., E. coli levels) in the stream water were predicted. With certain assumptions, model results are reasonable. This study can be used as guidelines for developing the models for calculating the impacts of crop land's animal manure on stream water

  11. The secondary metabolome of the fungal tomato pathogen Cladosporium fulvum

    NARCIS (Netherlands)

    Griffiths, S.A.

    2015-01-01

    Secondary metabolites (SMs) are biologically active organic compounds that are biosynthesised
    by many plants and microbes. Many SMs that affect the growth, behaviour or survival of other
    organsisms have been re-purposed for use as medicinal drugs, agricultural biocides and animal
    g

  12. Integrating Large-Scale Data and RNA Technology to Protect Crops from Fungal Pathogens.

    Science.gov (United States)

    Girard, Ian J; Mcloughlin, Austein G; de Kievit, Teresa R; Fernando, Dilantha W G; Belmonte, Mark F

    2016-01-01

    With a rapidly growing human population it is expected that plant science researchers and the agricultural community will need to increase food productivity using less arable land. This challenge is complicated by fungal pathogens and diseases, many of which can severely impact crop yield. Current measures to control fungal pathogens are either ineffective or have adverse effects on the agricultural enterprise. Thus, developing new strategies through research innovation to protect plants from pathogenic fungi is necessary to overcome these hurdles. RNA sequencing technologies are increasing our understanding of the underlying genes and gene regulatory networks mediating disease outcomes. The application of invigorating next generation sequencing strategies to study plant-pathogen interactions has and will provide unprecedented insight into the complex patterns of gene activity responsible for crop protection. However, questions remain about how biological processes in both the pathogen and the host are specified in space directly at the site of infection and over the infection period. The integration of cutting edge molecular and computational tools will provide plant scientists with the arsenal required to identify genes and molecules that play a role in plant protection. Large scale RNA sequence data can then be used to protect plants by targeting genes essential for pathogen viability in the production of stably transformed lines expressing RNA interference molecules, or through foliar applications of double stranded RNA. PMID:27303409

  13. Integrating large-scale data and RNA technology to protect crops from fungal pathogens

    Directory of Open Access Journals (Sweden)

    Ian Joseph Girard

    2016-05-01

    Full Text Available With a rapidly growing human population it is expected that plant science researchers and the agricultural community will need to increase food productivity using less arable land. This challenge is complicated by fungal pathogens and diseases, many of which can severely impact crop yield. Current measures to control fungal pathogens are either ineffective or have adverse effects on the agricultural enterprise. Thus, developing new strategies through research innovation to protect plants from pathogenic fungi is necessary to overcome these hurdles. RNA sequencing technologies are increasing our understanding of the underlying genes and gene regulatory networks mediating disease outcomes. The application of invigorating next generation sequencing strategies to study plant-pathogen interactions has and will provide unprecedented insight into the complex patterns of gene activity responsible for crop protection. However, questions remain about how biological processes in both the pathogen and the host are specified in space directly at the site of infection and over the infection period. The integration of cutting edge molecular and computational tools will provide plant scientists with the arsenal required to identify genes and molecules that play a role in plant protection. Large scale RNA sequence data can then be used to protect plants by targeting genes essential for pathogen viability in the production of stably transformed lines expressing RNA interference molecules, or through foliar applications of double stranded RNA.

  14. Social barriers to pathogen transmission in wild animal populations

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C.

    1995-03-01

    Diseases and pathogens are receiving increasing recognition as sources of mortality in animal populations. Immune system strength is clearly important in fending off pathogen attack. Physical barriers to pathogen entry are also important. Various individual behaviors are efficacious in reducing contact with diseases and pests. This paper focuses on a fourth mode of defense: social barriers to transmission. Various social behaviors have pathogen transmission consequences. Selective pressures on these social behaviors may therefore exist. Effects on pathogen transmission of mating strategies, social avoidance, group size, group isolation, and other behaviors are explored. It is concluded that many of these behaviors may have been affected by selection pressures to reduce transmission of pathogens. 84 refs., 1 tab.

  15. Ancient dispersal of the human fungal pathogen Cryptococcus gattii from the Amazon rainforest

    NARCIS (Netherlands)

    Hagen, F.; Ceresini, P.C.; Polacheck, I.; Ma, H.; van Nieuwerburgh, F.; Gabaldon, T.; Kagan, S.; Pursall, E.R.; Hoogveld, H.L.; van Iersel, L.J.; Klau, G.W.; Kelk, S.M.; Stougie, L.; Bartlett, K.H.; Voelz, K.; Pryszcz, L.P.; Castaneda, E.; Lazera, M.; Meyer, W.; Deforce, D.; Meis, J.F.G.M.; May, R.C.; Klaassen, C.H.W.; Boekhout, T.

    2013-01-01

    Over the past two decades, several fungal outbreaks have occurred, including the high-profile 'Vancouver Island' and 'Pacific Northwest' outbreaks, caused by Cryptococcus gattii, which has affected hundreds of otherwise healthy humans and animals. Over the same time period, C. gattii was the cause o

  16. Ancient Dispersal of the Human Fungal Pathogen Cryptococcus gattii from the Amazon Rainforest

    NARCIS (Netherlands)

    Hagen, Ferry; Ceresini, Paulo C.; Polacheck, Itzhack; Ma, Hansong; van Nieuwerburgh, Filip; Gabaldon, Toni; Kagan, Sarah; Pursall, E. Rhiannon; Hoogveld, Hans L.; van Iersel, Leo J. J.; Klau, Gunnar W.; Kelk, Steven M.; Stougie, Leen; Bartlett, Karen H.; Voelz, Kerstin; Pryszcz, Leszek P.; Castaneda, Elizabeth; Lazera, Marcia; Meyer, Wieland; Deforce, Dieter; Meis, Jacques F.; May, Robin C.; Klaassen, Corne H. W.; Boekhout, Teun

    2013-01-01

    Over the past two decades, several fungal outbreaks have occurred, including the high-profile 'Vancouver Island' and 'Pacific Northwest' outbreaks, caused by Cryptococcus gattii, which has affected hundreds of otherwise healthy humans and animals. Over the same time period, C. gattii was the cause o

  17. Identification of fungal pathogens in Formalin-fixed, Paraffin-embedded tissue samples by molecular methods.

    Science.gov (United States)

    Rickerts, Volker

    2016-02-01

    The etiology of invasive fungal infections (IFI) is incompletely understood due to diagnostic limitations including insensitivity of cultures and failure of histopathology to discriminate between different species. This diagnostic gap precludes the optimal use of antifungals, leading to adverse patient outcomes. The identification of fungal pathogens from Formalin-fixed, Paraffin-embedded tissue (FFPE) blocks by molecular methods is emerging as an alternative approach to study the etiology of IFI. PCR assays, including species specific- and broadrange fungal tests are used with FFPE samples from patients with proven IFI. Fungal species identification is achieved in 15-90% of the samples. This heterogeneity may be explained by the samples studied. However, comparison of different studies is impaired, as controls ruling out false positive-, false negative test results or PCR inhibition are frequently not reported. Studies using in situ hybridization also vary in the clinical samples included and the targeted fungi. In addition, target sequences, the probe chemistry and the detection of hybridization signals also account for the differences in diagnostic sensitivity. Using both approaches in parallel yields additive insights, potentially leading to a superior identification of fungal etiology and awareness of the limitations of both molecular diagnostic approaches.

  18. The Fungal Pathogen Aspergillus fumigatus Regulates Growth, Metabolism, and Stress Resistance in Response to Light

    OpenAIRE

    Fuller, Kevin K.; Ringelberg, Carol S.; Loros, Jennifer J.; Dunlap, Jay C

    2013-01-01

    ABSTRACT Light is a pervasive environmental factor that regulates development, stress resistance, and even virulence in numerous fungal species. Though much research has focused on signaling pathways in Aspergillus fumigatus, an understanding of how this pathogen responds to light is lacking. In this report, we demonstrate that the fungus does indeed respond to both blue and red portions of the visible spectrum. Included in the A. fumigatus light response is a reduction in conidial germinatio...

  19. Fungal trunk pathogens associated with wood decay of pistachio trees in Iran

    OpenAIRE

    Hamid Mohammadi; Mehdi Sarcheshmehpour; Ebrahim Mafi

    2015-01-01

    Over the growing seasons of 2011–2013, various pistachio (Pistacia vera L.) cv. Fandoghi, and wild pistachio (P. atlantica Desf. subsp. mutica) trees were inspected in Iran to determine the aetiology of trunk diseases with specific reference to species of Phaeoacremonium and Botryosphaeriaceae spp. Samples were collected from branches of trees exhibiting yellowing, defoliation, canker and dieback, as well as wood discoloration in cross sections. Fungal trunk pathogens were identified using mo...

  20. Caterpillars and Fungal Pathogens: Two Co-Occurring Parasites of an Ant-Plant Mutualism

    OpenAIRE

    Olivier Roux; Régis Céréghino; Solano, Pascal J.; Alain Dejean

    2011-01-01

    International audience In mutualisms, each interacting species obtains resources from its partner that it would obtain less efficiently if alone, and so derives a net fitness benefit. In exchange for shelter (domatia) and food, mutualistic plant-ants protect their host myrmecophytes from herbivores, encroaching vines and fungal pathogens. Although selective filters enable myrmecophytes to host those ant species most favorable to their fitness, some insects can by-pass these filters, exploi...

  1. Ant queens (Hymenoptera: Formicidae) are attracted to fungal pathogens during the initial stage of colony founding

    OpenAIRE

    Brütsch T.; Felden A.; Reber A.; Chapuisat M.

    2014-01-01

    Ant queens that attempt to disperse and found new colonies independently face high mortality risks. The exposure of queens to soil entomopathogens during claustral colony founding may be particularly harmful, as founding queens lack the protection conferred by mature colonies. Here, we tested the hypotheses that founding queens (I) detect and avoid nest sites that are contaminated by fungal pathogens, and (II) tend to associate with other queens to benefit from social immunity when nest sites...

  2. Three promising fungal strains pathogenic to fruit flies

    Energy Technology Data Exchange (ETDEWEB)

    Jiji, T.; Praveena, R.; Babu, Kavitha; Naseema, A.; Anitha, N. [College of Agriculture, Kerala (India)

    2006-07-01

    Pathogenicity of the fungi Paecilomyces lilacinus, isolated from Bactrocera cucurbitae, and Aspergillus candidus, isolated from B. dorsalis, was tested. Cross infectivity of P. lilacinus on B. dorsalis and A. candidus on B. cucurbitae and cross infectivity of a local isolate of B. bassiana from bhindi leaf roller (Sylepta derogata) on fruit flies (B. cucurbitae and B. dorsalis ) were also studied. These fungi were new records in these hosts. P. lilacinus at 109 spores / ml caused 96.67% and 100 % cumulative mortality in fruit flies on the second and on the third days. LC50 values of P. lilacinus on B. cucurbitae were 5.0 x 106, 8.0 x 105, 7.0 x 105 spores/ ml on second, third and fourth day, respectively. The fungus was found to cross infect B. dorsalis. LC50 values of A. candidus on B. cucurbitae were 1.29 x 108, 1.22 x 107, 2.27 x 106 spores / ml on third, fourth and fifth day, respectively. The fungus was found to be cross infective to B. cucurbitae. B. bassiana at 109 spores/ ml on B. dorsalis was found to cause 70%, 80% and 90% mortality on fourth, fifth and sixth day. LC50 values of B. bassiana on B. dorsalis were 7.0 x 108, 2.0 x 107, 5.0 x 106 spores/ ml on third, fourth and fifth day ,respectively . Formulation of P. lilacinus as wettable powder and granules and B. bassiana as wettable powder, were also prepared and their efficacy was tested on hosts. (author)

  3. Fungal pathogens of Miconia calvescens (Melastomataceae) from Brazil, with reference to classical biological control.

    Science.gov (United States)

    Seixas, Claudine D S; Barreto, Robert W; Killgore, Eloise

    2007-01-01

    A survey of fungal pathogens of Miconia calvescens was carried out in Brazil aimed at finding potential classical biocontrol agents for management of this invasive alien weed in Hawaii. Coccodiella miconiae, Glomerella cingulata (= Colletotrichum gloeosporioides f. sp. miconiae) and the new species Guignardia miconiae and Korunomyces prostratus were found associated with foliar diseases and are described herein. Two previously undescribed spore stages of Coccodiella miconiae also were obtained allowing a complete description of this species. Pseudocercospora tamonae associated with leaf spots of other species of Miconia also was collected and also was proven to be pathogenic to M. calvescens. PMID:17663128

  4. Molecular identification of fungal pathogens in nodular skin lesions of cats.

    Science.gov (United States)

    Bernhardt, Anne; von Bomhard, Wolf; Antweiler, Elisabeth; Tintelnot, Kathrin

    2015-02-01

    In a retrospective study, we investigated 52 formalin-fixed, paraffin-embedded (FFPE) samples from cats with histologically confirmed cutaneous and subcutaneous mycoses to determine if the pathogens could be identified by molecular methods. Aim of the study was to obtain a deep understanding of the spectrum of infectious agents, which, as we hypothesized, was not available by histopathology alone. Detection of feline and fungal DNA was achieved in 92.3% and 94.2% of the samples, respectively. Most of the subcutaneous infections in cats were caused by Alternaria spp. (63.5%), followed by Cryptococcus neoformans (7.7%), Histoplasma capsulatum (5.8%), Sporothrix spp. (3.8%), Aspergillus vitricola, Aureobasidium pullulans, Exophiala attenuata, Fusarium oxysporum, Lecythophora cateniformis, Microsporum canis, and Phialophora sp. (1.9% each). The results from molecular identification indicate that correct identifications of the fungal pathogens by histology alone were rarely possible. The spectrum of fungal pathogens identified after DNA extraction from FFPE samples was much broader than that expected by classical histopathology. This was especially noted in alternariosis in that the micromorphological pattern in tissue was misleading and could be confused with that of cryptococcosis. Due to different susceptibilities to antifungal agents, it is important to arrive at a definitive diagnosis, which might be possible by examination of the fungus recovered in culture and/or molecular methods, in addition to the histopathologic techniques. PMID:25550386

  5. Anti-fungal activity of some medicinal plants on different pathogenic fungi

    International Nuclear Information System (INIS)

    The antifungal activity of different medicinal and locally available plants extracts (leaves, fruit, seeds) which are usually found in the surrounding of fields or in the fields on some fungi were tested in lab conditions. Six different plants were selected for testing these plants were Acacia nilotica (Lamk.) Willd. Azadirachta indica (A.) Juss. Crotalaria juncea L. Eucalyptus camaldulensis Dehnh. Ocimum basilicum L. and Prosopis juliflora (Sw.) Dc. These plants showed antifungal activity against the Aspergillus flavus, A. niger, Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani. These plants crude extracts of leaves showed inhibition activity against the fungi and suppressed the myclial growth. Over all selected plants exhibited moderate type of inhibition against these above mentioned pathogens. Among these plants, Azadirachta indica, Ocimum basilicum and Crotalaria juncea showed the most effective results against the Aspergillus, Fusarium and Rhizoctonia sp. of fungal pathogens. Whereas, Acacia nilotica, Eucalyptus camaldulensis and Prosopis juliflora showed least potential of inhibition against all above mentioned fungal pathogens. It is investigated in present studies that Azadirachta indica, Ocimum basilicum and Crotalaria juncea can be utilized against the management of fungal diseases particularly Aspergillus flavus, A. niger, Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani. (author)

  6. Arabidopsis WRKY33 transcription factor is required for resistance to necrotrophic fungal pathogens.

    Science.gov (United States)

    Zheng, Zuyu; Qamar, Synan Abu; Chen, Zhixiang; Mengiste, Tesfaye

    2006-11-01

    Plant WRKY transcription factors are key regulatory components of plant responses to microbial infection. In addition to regulating the expression of defense-related genes, WRKY transcription factors have also been shown to regulate cross-talk between jasmonate- and salicylate-regulated disease response pathways. The two pathways mediate resistance against different types of microbial pathogens, and there are numerous reports of antagonistic interactions between them. Here we show that mutations of the Arabidopsis WRKY33 gene encoding a WRKY transcription factor cause enhanced susceptibility to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola concomitant with reduced expression of the jasmonate-regulated plant defensin PDF1.2 gene. Ectopic over-expression of WRKY33, on the other hand, increases resistance to the two necrotrophic fungal pathogens. The wrky33 mutants do not show altered responses to a virulent strain of the bacterial pathogen Pseudomonas syringae, although the ectopic expression of WRKY33 results in enhanced susceptibility to this pathogen. The susceptibility of WRKY33-over-expressing plants to P. syringae is associated with reduced expression of the salicylate-regulated PR-1 gene. The WRKY33 transcript is induced in response to pathogen infection, or treatment with salicylate or the paraquat herbicide that generates activated oxygen species in exposed cells. WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence. Together, these results indicate that pathogen-induced WRKY33 is an important transcription factor that regulates the antagonistic relationship between defense pathways mediating responses to P. syringae and necrotrophic pathogens.

  7. Control of Plant Parasitic Nematodes and Soil Borne Fungal Pathogens by Soil Solarization in Northern Region of Libya

    OpenAIRE

    Ali Mahmoud Zaid; Waseim Esmael; Fawazi Bashie; Masaud Gajeam

    2014-01-01

    Soil Solarization is a new sustainable method that has been shown to be effective in the control of plant parasitic nematodes, soil borne fungal pathogens, and weeds. Organic agriculture could benefit most using such technique to reduce crop losses. The effect of soil solarization in The control of plant parasitic nematodes and soil borne fungal pathogens was studied in two uncovered plastic houses in two private farms by covering the soil with polyethlyne tarps 40um.thick for 30 and 45 days ...

  8. Transcriptomic Crosstalk between Fungal Invasive Pathogens and Their Host Cells: Opportunities and Challenges for Next-Generation Sequencing Methods

    OpenAIRE

    Francisco J Enguita; Costa, Marina C.; Ana Marisa Fusco-Almeida; Maria José Mendes-Giannini; Ana Lúcia Leitão

    2016-01-01

    Fungal invasive infections are an increasing health problem. The intrinsic complexity of pathogenic fungi and the unmet clinical need for new and more effective treatments requires a detailed knowledge of the infection process. During infection, fungal pathogens are able to trigger a specific transcriptional program in their host cells. The detailed knowledge of this transcriptional program will allow for a better understanding of the infection process and consequently will help in the future...

  9. Identification and functional characterization of proteases and protease inhibitors involved in virulence of fungal tomato pathogens

    NARCIS (Netherlands)

    Karimi Jashni, M.

    2015-01-01

    Pathogens cause disease on both animal and plant hosts. For successful infection and establishment of disease, pathogens need proper weaponry to protect themselves against host defenses and to promote host colonization to facilitate uptake of nutrients for growth and reproduction. Indeed, plant path

  10. Recent developments in pathogen detection arrays: implications for fungal plant pathogens and use in practica

    NARCIS (Netherlands)

    Lievens, B.; Thomma, B.P.H.J.

    2005-01-01

    The failure to adequately identify plant pathogens from culture-based morphological techniques has led to the development of culture-independent molecular approaches. Increasingly, diagnostic laboratories are pursuing fast routine methods that provide reliable identification, sensitive detection, an

  11. Isolation of pathogenic yersiniae from wild animals in Bulgaria.

    Science.gov (United States)

    Nikolova, S; Tzvetkov, Y; Najdenski, H; Vesselinova, A

    2001-04-01

    Pathogenic Yersinia strains were isolated between December 1998 and April 1999 from 37 wild animals: rabbit (Lepus europeus), boar (Sus scrofa scrofa), asiatic jackal (Canis aureus), red fox (Vulpes vulpes), mouflon (Ovis musimon), european river otter (Lutra lutra), beech marten (Martes foina), polecat (Musleta putorius) and wild cat (Felis silvestris). It was established that among the wild animals Y. enterocolitica strains of serotype 0:3 predominated, accompanied by Y. pseudotuberculosis strains of serotype 0:3. In one sample from asiatic jackal and one sample from rabbit, Y. enterocolitica serotype 0:8 was isolated. Yersinia enterocolitica and Y. pseudotuberculosis strains were isolated from tonsils and tongues as well as from the viscera--lung, liver, heart, spleen, kidney and lymph nodes, mainly in young animals (1-2 years of age). The results showed that wild animals are a possible natural reservoir for pathogenic Y. enterocolitica and Y. pseudotuberculosis and are included in the epidemiological chain of yersinioses. PMID:11393816

  12. Comparative genomics allowed the identification of drug targets against human fungal pathogens

    Directory of Open Access Journals (Sweden)

    Martins Natalia F

    2011-01-01

    Full Text Available Abstract Background The prevalence of invasive fungal infections (IFIs has increased steadily worldwide in the last few decades. Particularly, there has been a global rise in the number of infections among immunosuppressed people. These patients present severe clinical forms of the infections, which are commonly fatal, and they are more susceptible to opportunistic fungal infections than non-immunocompromised people. IFIs have historically been associated with high morbidity and mortality, partly because of the limitations of available antifungal therapies, including side effects, toxicities, drug interactions and antifungal resistance. Thus, the search for alternative therapies and/or the development of more specific drugs is a challenge that needs to be met. Genomics has created new ways of examining genes, which open new strategies for drug development and control of human diseases. Results In silico analyses and manual mining selected initially 57 potential drug targets, based on 55 genes experimentally confirmed as essential for Candida albicans or Aspergillus fumigatus and other 2 genes (kre2 and erg6 relevant for fungal survival within the host. Orthologs for those 57 potential targets were also identified in eight human fungal pathogens (C. albicans, A. fumigatus, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Paracoccidioides lutzii, Coccidioides immitis, Cryptococcus neoformans and Histoplasma capsulatum. Of those, 10 genes were present in all pathogenic fungi analyzed and absent in the human genome. We focused on four candidates: trr1 that encodes for thioredoxin reductase, rim8 that encodes for a protein involved in the proteolytic activation of a transcriptional factor in response to alkaline pH, kre2 that encodes for α-1,2-mannosyltransferase and erg6 that encodes for Δ(24-sterol C-methyltransferase. Conclusions Our data show that the comparative genomics analysis of eight fungal pathogens enabled the identification of

  13. Isolation and characterization of soil Streptomyces species as potential biological control agents against fungal plant pathogens.

    Science.gov (United States)

    Evangelista-Martínez, Zahaed

    2014-05-01

    The use of antagonist microorganisms against fungal plant pathogens is an attractive and ecologically alternative to the use of chemical pesticides. Streptomyces are beneficial soil bacteria and potential candidates for biocontrol agents. This study reports the isolation, characterization and antagonist activity of soil streptomycetes from the Los Petenes Biosphere Reserve, a Natural protected area in Campeche, Mexico. The results showed morphological, physiological and biochemical characterization of six actinomycetes and their inhibitory activity against Curvularia sp., Aspergillus niger, Helminthosporium sp. and Fusarium sp. One isolate, identified as Streptomyces sp. CACIS-1.16CA showed the potential to inhibit additional pathogens as Alternaria sp., Phytophthora capsici, Colletotrichum sp. and Rhizoctonia sp. with percentages ranging from 47 to 90 %. This study identified a streptomycete strain with a broad antagonist activity that could be used for biocontrol of plant pathogenic fungi. PMID:24310522

  14. Structures of Cryptococcus neoformans Protein Farnesyltransferase Reveal Strategies for Developing Inhibitors That Target Fungal Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Hast, Michael A.; Nichols, Connie B.; Armstrong, Stephanie M.; Kelly, Shannon M.; Hellinga, Homme W.; Alspaugh, J. Andrew; Beese, Lorena S. (Duke)

    2012-09-17

    Cryptococcus neoformans is a fungal pathogen that causes life-threatening infections in immunocompromised individuals, including AIDS patients and transplant recipients. Few antifungals can treat C. neoformans infections, and drug resistance is increasing. Protein farnesyltransferase (FTase) catalyzes post-translational lipidation of key signal transduction proteins and is essential in C. neoformans. We present a multidisciplinary study validating C. neoformans FTase (CnFTase) as a drug target, showing that several anticancer FTase inhibitors with disparate scaffolds can inhibit C. neoformans and suggesting structure-based strategies for further optimization of these leads. Structural studies are an essential element for species-specific inhibitor development strategies by revealing similarities and differences between pathogen and host orthologs that can be exploited. We, therefore, present eight crystal structures of CnFTase that define the enzymatic reaction cycle, basis of ligand selection, and structurally divergent regions of the active site. Crystal structures of clinically important anticancer FTase inhibitors in complex with CnFTase reveal opportunities for optimization of selectivity for the fungal enzyme by modifying functional groups that interact with structurally diverse regions. A substrate-induced conformational change in CnFTase is observed as part of the reaction cycle, a feature that is mechanistically distinct from human FTase. Our combined structural and functional studies provide a framework for developing FTase inhibitors to treat invasive fungal infections.

  15. Fungal pathogen uses sex pheromone receptor for chemotropic sensing of host plant signals.

    Science.gov (United States)

    Turrà, David; El Ghalid, Mennat; Rossi, Federico; Di Pietro, Antonio

    2015-11-26

    For more than a century, fungal pathogens and symbionts have been known to orient hyphal growth towards chemical stimuli from the host plant. However, the nature of the plant signals as well as the mechanisms underlying the chemotropic response have remained elusive. Here we show that directed growth of the soil-inhabiting plant pathogen Fusarium oxysporum towards the roots of the host tomato (Solanum lycopersicum) is triggered by the catalytic activity of secreted class III peroxidases, a family of haem-containing enzymes present in all land plants. The chemotropic response requires conserved elements of the fungal cell integrity mitogen-activated protein kinase (MAPK) cascade and the seven-pass transmembrane protein Ste2, a functional homologue of the Saccharomyces cerevisiae sex pheromone α receptor. We further show that directed hyphal growth of F. oxysporum towards nutrient sources such as sugars and amino acids is governed by a functionally distinct MAPK cascade. These results reveal a potentially conserved chemotropic mechanism in root-colonizing fungi, and suggest a new function for the fungal pheromone-sensing machinery in locating plant hosts in a complex environment such as the soil. PMID:26503056

  16. Characterisation of a Trichoderma hamatum monooxygenase gene involved in antagonistic activity against fungal plant pathogens.

    Science.gov (United States)

    Carpenter, Margaret A; Ridgway, Hayley J; Stringer, Alison M; Hay, Amanda J; Stewart, Alison

    2008-04-01

    A monooxygenase gene was isolated from a biocontrol strain of Trichoderma hamatum and its role in biocontrol was investigated. The gene had homologues in other fungal genomes, but was not closely related to any fully characterised gene. The T. hamatum monooxygenase gene was expressed specifically in response to the plant pathogens Sclerotinia sclerotiorum, Sclerotinia minor and Sclerotium cepivorum, but not in response to Botrytis cinerea or T. hamatum. Expression of the gene did not occur until contact had been made between the two fungal species. Homologues in T. atroviride and T. virens showed similar expression patterns. Expression of the gene in response to S. sclerotiorum was influenced by pH, with a peak of expression at pH 4, and was subject to nitrogen catabolite repression. Disruption of the monooxygenase gene did not affect the growth or morphology of T. hamatum, but caused a decrease in its ability to inhibit the growth and sclerotial production of S. sclerotiorum. The monooxygenase gene had a role in the antagonistic activity of Trichoderma species against specific fungal plant pathogens and is therefore a potentially important factor in biocontrol by Trichoderma species. PMID:18231791

  17. Nanoscale biophysical properties of the cell surface galactosaminogalactan from the fungal pathogen Aspergillus fumigatus.

    Science.gov (United States)

    Beaussart, Audrey; El-Kirat-Chatel, Sofiane; Fontaine, Thierry; Latgé, Jean-Paul; Dufrêne, Yves F

    2015-09-28

    Many fungal pathogens produce cell surface polysaccharides that play essential roles in host-pathogen interactions. In Aspergillus fumigatus, the newly discovered polysaccharide galactosaminogalactan (GAG) mediates adherence to a variety of substrates through molecular mechanisms that are poorly understood. Here we use atomic force microscopy to unravel the localization and adhesion of GAG on living fungal cells. Using single-molecule imaging with tips bearing anti-GAG antibodies, we found that GAG is massively exposed on wild-type (WT) germ tubes, consistent with the notion that this glycopolymer is secreted by the mycelium of A. fumigatus, while it is lacking on WT resting conidia and on germ tubes from a mutant (Δuge3) deficient in GAG. Imaging germ tubes with tips bearing anti-β-glucan antibodies shows that exposure of β-glucan is strongly increased in the Δuge3 mutant, indicating that this polysaccharide is masked by GAG during hyphal growth. Single-cell force measurements show that expression of GAG on germ tubes promotes specific adhesion to pneumocytes and non-specific adhesion to hydrophobic substrates. These results provide a molecular foundation for the multifunctional adhesion properties of GAG, thus suggesting it could be used as a potential target in anti-adhesion therapy and immunotherapy. Our methodology represents a powerful approach for characterizing the nanoscale organization and adhesion of cell wall polysaccharides during fungal morphogenesis, thereby contributing to increase our understanding of their role in biofilm formation and immune responses.

  18. Fungal Inositol Pyrophosphate IP7 Is Crucial for Metabolic Adaptation to the Host Environment and Pathogenicity

    Science.gov (United States)

    Lev, Sophie; Li, Cecilia; Desmarini, Desmarini; Saiardi, Adolfo; Fewings, Nicole L.; Schibeci, Stephen D.; Sharma, Raghwa; Sorrell, Tania C.

    2015-01-01

    ABSTRACT Inositol pyrophosphates (PP-IPs) comprising inositol, phosphate, and pyrophosphate (PP) are essential for multiple functions in eukaryotes. Their role in fungal pathogens has never been addressed. Cryptococcus neoformans is a model pathogenic fungus causing life-threatening meningoencephalitis. We investigate the cryptococcal kinases responsible for the production of PP-IPs (IP7/IP8) and the hierarchy of PP-IP importance in pathogenicity. Using gene deletion and inositol polyphosphate profiling, we identified Kcs1 as the major IP6 kinase (producing IP7) and Asp1 as an IP7 kinase (producing IP8). We show that Kcs1-derived IP7 is the most crucial PP-IP for cryptococcal drug susceptibility and the production of virulence determinants. In particular, Kcs1 kinase activity is essential for cryptococcal infection of mouse lungs, as reduced fungal burdens were observed in the absence of Kcs1 or when Kcs1 was catalytically inactive. Transcriptome and carbon source utilization analysis suggested that compromised growth of the KCS1 deletion strain (Δkcs1 mutant) in the low-glucose environment of the host lung is due to its inability to utilize alternative carbon sources. Despite this metabolic defect, the Δkcs1 mutant established persistent, low-level asymptomatic pulmonary infection but failed to elicit a strong immune response in vivo and in vitro and was not readily phagocytosed by primary or immortalized monocytes. Reduced recognition of the Δkcs1 cells by monocytes correlated with reduced exposure of mannoproteins on the Δkcs1 mutant cell surface. We conclude that IP7 is essential for fungal metabolic adaptation to the host environment, immune recognition, and pathogenicity. PMID:26037119

  19. Study on the Biocontrol Activities of Trichoderma species in Greengram with Infected Fungal Pathogens

    International Nuclear Information System (INIS)

    Seven species of Trichoderma were isolated from rhizospheric soil sources and studied by cultural morphology and microscopic examinations. In dual plate assay, antifungal effects of seven Trichoderma strains were screened against three plant pathogenic fungi (Fusarium oxysporum, Rhizoctonia solani and Pythium sp.) on PDA medium and T-5 isolate showed a wide percentage of inhibitory effects on target pathogens with PIRG value. All Trichoderma strains exhibited a clear zone formation on minimal synthetic medium supplemented with 1% colloidal chitin. T-2 and T-5 were the best chitinase producer strains. In vitro screening for protease activity, the highest protease producing activity of Trichoderma isolate (T-2) were observed in pH indicator medium after 7 days incubation. In pot trial experiment, only T-5 strain exhibited more fungal suppression efficiency on green gram plant than commercial fungicide, Trisan and the other strains. So, it can be said that the effective strain was T-5 strain only which have been more antifungal producing power on three fungal pathogens than Trisan and the resting strains.

  20. Antagonistic Potential of Native Trichoderma viride Strain against Potent Tea Fungal Pathogens in North East India.

    Science.gov (United States)

    Naglot, A; Goswami, S; Rahman, I; Shrimali, D D; Yadav, Kamlesh K; Gupta, Vikas K; Rabha, Aprana Jyoti; Gogoi, H K; Veer, Vijay

    2015-09-01

    Indigenous strains of Trichoderma species isolated from rhizosphere soils of Tea gardens of Assam, north eastern state of India were assessed for in vitro antagonism against two important tea fungal pathogens namely Pestalotia theae and Fusarium solani. A potent antagonist against both tea pathogenic fungi, designated as SDRLIN1, was selected and identified as Trichoderma viride. The strain also showed substantial antifungal activity against five standard phytopathogenic fungi. Culture filtrate collected from stationary growth phase of the antagonist demonstrated a significantly higher degree of inhibitory activity against all the test fungi, demonstrating the presence of an optimal blend of extracellular antifungal metabolites. Moreover, quantitative enzyme assay of exponential and stationary culture filtrates revealed that the activity of cellulase, β-1,3-glucanase, pectinase, and amylase was highest in the exponential phase, whereas the activity of proteases and chitinase was noted highest in the stationary phase. Morphological changes such as hyphal swelling and distortion were also observed in the fungal pathogen grown on potato dextrose agar containing stationary phase culture filtrate. Moreover, the antifungal activity of the filtrate was significantly reduced but not entirely after heat or proteinase K treatment, demonstrating substantial role of certain unknown thermostable antifungal compound(s) in the inhibitory activity. PMID:26361476

  1. The GRF10 homeobox gene regulates filamentous growth in the human fungal pathogen Candida albicans.

    Science.gov (United States)

    Ghosh, Anup K; Wangsanut, Tanaporn; Fonzi, William A; Rolfes, Ronda J

    2015-12-01

    Candida albicans is the most common human fungal pathogen and can cause life-threatening infections. Filamentous growth is critical in the pathogenicity of C. albicans, as the transition from yeast to hyphal forms is linked to virulence and is also a pivotal process in fungal biofilm development. Homeodomain-containing transcription factors have been linked to developmental processes in fungi and other eukaryotes. We report here on GRF10, a homeobox transcription factor-encoding gene that plays a role in C. albicans filamentation. Deletion of the GRF10 gene, in both C. albicans SN152 and BWP17 strain backgrounds, results in mutants with strongly decreased hyphal growth. The mutants are defective in chlamydospore and biofilm formation, as well as showing dramatically attenuated virulence in a mouse infection model. Expression of the GRF10 gene is highly induced during stationary phase and filamentation. In summary, our study emphasizes a new role for the homeodomain-containing transcription factor in morphogenesis and pathogenicity of C. albicans.

  2. Induction of beta-1,3-glucanase in barley in response to infection by fungal pathogens.

    Science.gov (United States)

    Jutidamrongphan, W; Andersen, J B; Mackinnon, G; Manners, J M; Simpson, R S; Scott, K J

    1991-05-01

    The sequence of a partial cDNA clone corresponding to an mRNA induced in leaves of barley (Hordeum vulgare) by infection with fungal pathogens matched almost perfectly with that of a cDNA clone coding for beta-1,-3-glucanase isolated from the scutellum of barley. Western blot analysis of intercellular proteins from near-isogenic barley lines inoculated with the powdery mildew fungus (Erysiphe graminis f. sp. hordei) showed a strong induction of glucanase in all inoculated lines but was most pronounced in two resistant lines. These data were confirmed by beta-1,3-glucanase assays. The barley cDNA was used as a hybridization probe to detect mRNAs in barley, wheat (Triticum aestivum), rice (oryza sativus), and sorghum (Sorghum bicolor), which are induced by infection with the necrotrophic pathogen Bipolaris sorokiniana. These results demonstrate that activation of beta-1,3-glucanase genes may be a general response of cereals to infection by fungal pathogens.

  3. Molecular genetic characterisation of the Asc locus of tomato conferring resistance to the fungal pathogen Alternaria alternata f. sp. lycopersici

    NARCIS (Netherlands)

    Biezen, E.A. van der; Overduin, B.; Kneppers, T.J.A.; Mesbah, L.A.; Nijkamp, H.J.J.; Hille, J.

    1994-01-01

    The Alternaria stem canker disease of tomato is caused by the fungal pathogen Alternaria alternata f. sp. lycopersici and its host-selective AAL-toxins. Resistance to the pathogen and insensitivity to the toxins are conferred by the Asc locus on chromosome 3L. Sensitivity to AAL-toxins is a relative

  4. The expression of a bean PGIP in transgenic wheat confers increased resistance to the fungal pathogen Bipolaris sorokiniana.

    Science.gov (United States)

    Janni, Michela; Sella, Luca; Favaron, Francesco; Blechl, Ann E; De Lorenzo, Giulia; D'Ovidio, Renato

    2008-02-01

    A possible strategy to control plant pathogens is the improvement of natural plant defense mechanisms against the tools that pathogens commonly use to penetrate and colonize the host tissue. One of these mechanisms is represented by the host plant's ability to inhibit the pathogen's capacity to degrade plant cell wall polysaccharides. Polygalacturonase-inhibiting proteins (PGIP) are plant defense cell wall glycoproteins that inhibit the activity of fungal endopolygalacturonases (endo-PGs). To assess the effectiveness of these proteins in protecting wheat from fungal pathogens, we produced a number of transgenic wheat lines expressing a bean PGIP (PvPGIP2) having a wide spectrum of specificities against fungal PGs. Three independent transgenic lines were characterized in detail, including determination of the levels of PvPGIP2 accumulation and its subcellular localization and inhibitory activity. Results show that the transgene-encoded protein is correctly secreted into the apoplast, maintains its characteristic recognition specificities, and endows the transgenic wheat with new PG recognition capabilities. As a consequence, transgenic wheat tissue showed increased resistance to digestion by the PG of Fusarium moniliforme. These new properties also were confirmed at the plant level during interactions with the fungal pathogen Bipolaris sorokiniana. All three lines showed significant reductions in symptom progression (46 to 50%) through the leaves following infection with this pathogen. Our results illustrate the feasibility of improving wheat's defenses against pathogens by expression of proteins with new capabilities to counteract those produced by the pathogens.

  5. Lutein, a Natural Carotenoid, Induces α-1,3-Glucan Accumulation on the Cell Wall Surface of Fungal Plant Pathogens.

    Science.gov (United States)

    Otaka, Junnosuke; Seo, Shigemi; Nishimura, Marie

    2016-01-01

    α-1,3-Glucan, a component of the fungal cell wall, is a refractory polysaccharide for most plants. Previously, we showed that various fungal plant pathogens masked their cell wall surfaces with α-1,3-glucan to evade plant immunity. This surface accumulation of α-1,3-glucan was infection specific, suggesting that plant factors might induce its production in fungi. Through immunofluorescence observations of fungal cell walls, we found that carrot (Daucus carota) extract induced the accumulation of α-1,3-glucan on germlings in Colletotrichum fioriniae, a polyphagous fungal pathogen that causes anthracnose disease in various dicot plants. Bioassay-guided fractionation of carrot leaf extract successfully identified two active substances that caused α-1,3-glucan accumulation in this fungus: lutein, a carotenoid widely distributed in plants, and stigmasterol, a plant-specific membrane component. Lutein, which had a greater effect on C. fioriniae, also induced α-1,3-glucan accumulation in other Colletotrichum species and in the phylogenetically distant rice pathogen Cochliobolus miyabeanus, but not in the rice pathogen Magnaporthe oryzae belonging to the same phylogenetic subclass as Colletotrichum. Our results suggested that fungal plant pathogens reorganize their cell wall components in response to specific plant-derived compounds, which these pathogens may encounter during infection. PMID:27483218

  6. Memory CD4+ T cells are required for optimal NK cell effector functions against the opportunistic fungal pathogen Pneumocystis murina.

    Science.gov (United States)

    Kelly, Michelle N; Zheng, Mingquan; Ruan, Sanbao; Kolls, Jay; D'Souza, Alain; Shellito, Judd E

    2013-01-01

    Little is known about the role of NK cells or their interplay with other immune cells during opportunistic infections. Using our murine model of Pneumocystis pneumonia, we found that loss of NK cells during immunosuppression results in substantial Pneumocystis lung burden. During early infection of C57B/6 CD4(+) T cell-depleted mice, there were significantly fewer NK cells in the lung tissue compared with CD4(+) T cell-intact animals, and the NK cells present demonstrated decreased upregulation of the activation marker NKp46 and production of the effector cytokine, IFN-γ. Furthermore, coincubation studies revealed a significant increase in fungal killing when NK cells were combined with CD4(+) T cells compared with either cell alone, which was coincident with a significant increase in perforin production by NK cells. Finally, however, we found through adoptive transfer that memory CD4(+) T cells are required for significant NK cell upregulation of the activation marker NK group 2D and production of IFN-γ, granzyme B, and perforin during Pneumocystis infection. To the best of our knowledge, this study is the first to demonstrate a role for NK cells in immunity to Pneumocystis pneumonia, as well as to establish a functional relationship between CD4(+) T cells and NK cells in the host response to an opportunistic fungal pathogen.

  7. Differential gene expression in Acromyrmex leaf-cutting ants after challenges with two fungal pathogens.

    Science.gov (United States)

    Yek, Sze H; Boomsma, Jacobus J; Schiøtt, Morten

    2013-04-01

    Social insects in general and leaf-cutting ants in particular have increased selection pressures on their innate immune system due to their social lifestyle and monoclonality of the symbiotic fungal cultivar. As this symbiosis is obligate for both parties, prophylactic behavioural defences against infections are expected to increase either ant survival or fungus-garden survival, but also to possibly trade off when specific infections differ in potential danger. We examined the effectiveness of prophylactic behaviours and modulations of innate immune defences by a combination of inoculation bioassays and genome-wide transcriptomic studies (RNA-Seq), using an ant pathogen (Metarhizium brunneum) and a fungus-garden pathogen (Escovopsis weberi) and administering inoculations both directly and indirectly (via the symbiotic partner). Upon detection of pathogen conidia, ant workers responded by increasing both general activity and the frequency of specific defence behaviours (self-grooming, allo-grooming, garden-grooming) independent of the pathogen encountered. This trend was also evident in the patterns of gene expression change. Both direct and indirect (via fungus garden) inoculations with Metarhizium induced a general up-regulation of gene expression, including a number of well-known immune-related genes. In contrast, direct inoculation of the fungus garden by Escovopsis induced an overall down-regulation of ant gene expression, whereas indirect inoculation (via the ants) did not, suggesting that increased activity of ants to remove this fungus-garden pathogen is costly and involves trade-offs with the activation of other physiological pathways. PMID:23480581

  8. Emerging trends in molecular interactions between plants and the broad host range fungal pathogens Botrytis cinerea and Sclerotinia sclerotiorum

    OpenAIRE

    Mbengue, Malick; Navaud, Olivier; Peyraud, Rémi; Barascud, Marielle; Badet, Thomas; Vincent, Rémy; Barbacci, Adelin; Raffaele, Sylvain

    2016-01-01

    Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is know...

  9. Fungal chitinases: function, regulation, and potential roles in plant/pathogen interactions.

    Science.gov (United States)

    Langner, Thorsten; Göhre, Vera

    2016-05-01

    In the past decades our knowledge about fungal cell wall architecture increased tremendously and led to the identification of many enzymes involved in polysaccharide synthesis and remodeling, which are also of biotechnological interest. Fungal cell walls play an important role in conferring mechanic stability during cell division and polar growth. Additionally, in phytopathogenic fungi the cell wall is the first structure that gets into intimate contact with the host plant. A major constituent of fungal cell walls is chitin, a homopolymer of N-acetylglucosamine units. To ensure plasticity, polymeric chitin needs continuous remodeling which is maintained by chitinolytic enzymes, including lytic polysaccharide monooxygenases N-acetylglucosaminidases, and chitinases. Depending on the species and lifestyle of fungi, there is great variation in the number of encoded chitinases and their function. Chitinases can have housekeeping function in plasticizing the cell wall or can act more specifically during cell separation, nutritional chitin acquisition, or competitive interaction with other fungi. Although chitinase research made huge progress in the last decades, our knowledge about their role in phytopathogenic fungi is still scarce. Recent findings in the dimorphic basidiomycete Ustilago maydis show that chitinases play different physiological functions throughout the life cycle and raise questions about their role during plant-fungus interactions. In this work we summarize these functions, mechanisms of chitinase regulation and their putative role during pathogen/host interactions. PMID:26527115

  10. Antimicrobial potential of Ricinus communis leaf extracts in different solvents against pathogenic bacterial and fungal strains

    Institute of Scientific and Technical Information of China (English)

    Rabia Naz; Asghari Bano

    2012-01-01

    Objective: To investigate the in vitro antimicrobial activities of the leaf extract in different solvents viz., methanol, ethanol and water extracts of the selected plant Ricinus communis. Methods:Agar well diffusion method and agar tube dilution method were carried out to perform the antibacterial and antifungal activity of methanol, ethanol and aqueous extracts. Results:Methanol leaf extracts were found to be more active against Gram positive bacteria (Bacillus subtilis: ATCC 6059 and Staphylococcus aureus: ATCC 6538) as well as Gram negative bacteria (Pseudomonas aeruginosa: ATCC 7221 and Klebsiella pneumoniae) than ethanol and aqueous leaf extracts. Antifungal activity of methanol and aqueous leaf extracts were also carried out against selected fungal strains as Aspergillus fumigatus and Aspergillus flavus. Methanolic as well as aqueous leaf extracts of Ricinus communis were effective in inhibiting the fungal growth. Conclusions: The efficient antibacterial and antifungal activity of Ricinus communis from the present investigation revealed that the methanol leaf extracts of the selected plant have significant potential to inhibit the growth of pathogenic bacterial and fungal strains than ethanol and aqueous leaf extracts.

  11. In Vitro Studies of the Activity of Dithiocarbamate Organoruthenium Complexes against Clinically Relevant Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    Claudio L. Donnici

    2014-04-01

    Full Text Available The in vitro antifungal activity of nine dirutheniumpentadithiocarbamate complexes C1–C9 was investigated and assessed for its activity against four different fungal species with clinical interest and related to invasive fungal infections (IFIs, such as Candida spp. [C. albicans (two clinical isolates, C. glabrata, C. krusei, C. parapsolisis, C. tropicalis, C.dubliniensis (six clinical isolates], Paracoccidioides brasiliensis (seven clinical isolates, Cryptococcus neoformans and Sporothrix schenckii. All synthesized complexes C1–C9 and also the free ligands L1–L9 were submitted to in vitro tests against those fungi and the results are very promising, since some of the obtained MIC (minimal inhibitory concentration values were very low (from 10−6 mol mL−1 to 10−8 mol mL−1 against all investigated clinically relevant fungal pathogens, except for C. glabrata, that the MIC values are close to the ones obtained for fluconazole, the standard antifungal agent tested. Preliminary structure-activity relations (SAR might be suggested and a strong influence from steric and lipophilic parameters in the antifungal activity can be noticed. Cytotoxicity assays (IC50 showed that the complexes are not as toxic (IC50 values are much higher—30 to 200 fold—than MIC values. These ruthenium complexes are very promising lead compounds for novel antifungal drug development, especially in IFIs, one of most harmful emerging infection diseases (EIDs.

  12. Climate change triggers effects of fungal pathogens and insect herbivores on litter decomposition

    Science.gov (United States)

    Butenschoen, Olaf; Scheu, Stefan

    2014-10-01

    Increasing infestation by insect herbivores and pathogenic fungi in response to climate change will inevitably impact the amount and quality of leaf litter inputs into the soil. However, little is known on the interactive effect of infestation severity and climate change on litter decomposition, and no such study has been published for deciduous forests in Central Europe. We assessed changes in initial chemical quality of beech (Fagus sylvatica L.) and maple litter (Acer platanoides L.) in response to infestation by the gall midge Mikiola fagi Hart. and the pathogenic fungus Sawadaea tulasnei Fuckel, respectively, and investigated interactive effects of infestation severity, changes in temperature and soil moisture on carbon mineralization in a short-term laboratory study. We found that infestation by the gall midge M. fagi and the pathogenic fungus S. tulasnei significantly changed the chemical quality of beech and maple litter. Changes in element concentrations were generally positive and more pronounced, and if negative less pronounced for maple than beech litter most likely due to high quality fungal tissue remaining on litter after abscission. More importantly, alterations in litter chemical quality did not translate to distinct patterns of carbon mineralization at ambient conditions, but even low amounts of infested litter accelerated carbon mineralization at moderately increased soil moisture and in particular at higher temperature. Our results indicate that insect herbivores and fungal pathogens can markedly alter initial litter chemical quality, but that afterlife effects on carbon mineralization depend on soil moisture and temperature, suggesting that increased infestation severity under projected climate change potentially increases soil carbon release in deciduous forests in Central Europe.

  13. Fungal-specific transcription factor AbPf2 activates pathogenicity in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yangrae; Ohm, Robin A.; Grigoriev, Igor V.; Srivastava, Akhil

    2012-12-03

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. To identify molecular determinants of pathogenicity, we created non-pathogenic mutants of a transcription factor-encoding gene, AbPf2. The frequency and timing of germination and appressorium formation on host plants were similar between the non-pathogenic abpf2 mutants and wild-type A. brassicicola. The mutants were also similar in vitro to wild-type A. brassicicola in terms of vegetative growth, conidium production, and responses to a phytoalexin, reactive oxygen species and osmolites. The hyphae of the mutants grew slowly but did not cause disease symptoms on the surface of host plants. Transcripts of the AbPf2 gene increased exponentially soon after wild-type conidia contacted their host plants . A small amount of AbPf2 protein, as monitored using GFP fusions, was present in young, mature conidia. The protein level decreased during saprophytic growth, but increased and was located primarily in fungal nuclei during pathogenesis. Levels of the proteins and transcripts sharply decreased following colonization of host tissues beyond the initial infection site. When expression of the transcription factor was induced in the wild-type during early pathogenesis, 106 fungal genes were also induced in the wild-type but not in the abpf2 mutants. Notably, 33 of the 106 genes encoded secreted proteins, including eight putative effector proteins. Plants inoculated with abpf2 mutants expressed higher levels of genes associated with photosynthesis, the pentose phosphate pathway and primary metabolism, but lower levels of defense-related genes. Our results suggest that AbPf2 is an important regulator of pathogenesis, but does not affect other cellular processes in A. brassicicola.

  14. Caterpillars and fungal pathogens: two co-occurring parasites of an ant-plant mutualism.

    Science.gov (United States)

    Roux, Olivier; Céréghino, Régis; Solano, Pascal J; Dejean, Alain

    2011-01-01

    In mutualisms, each interacting species obtains resources from its partner that it would obtain less efficiently if alone, and so derives a net fitness benefit. In exchange for shelter (domatia) and food, mutualistic plant-ants protect their host myrmecophytes from herbivores, encroaching vines and fungal pathogens. Although selective filters enable myrmecophytes to host those ant species most favorable to their fitness, some insects can by-pass these filters, exploiting the rewards supplied whilst providing nothing in return. This is the case in French Guiana for Cecropia obtusa (Cecropiaceae) as Pseudocabima guianalis caterpillars (Lepidoptera, Pyralidae) can colonize saplings before the installation of their mutualistic Azteca ants. The caterpillars shelter in the domatia and feed on food bodies (FBs) whose production increases as a result. They delay colonization by ants by weaving a silk shield above the youngest trichilium, where the FBs are produced, blocking access to them. This probable temporal priority effect also allows female moths to lay new eggs on trees that already shelter caterpillars, and so to occupy the niche longer and exploit Cecropia resources before colonization by ants. However, once incipient ant colonies are able to develop, they prevent further colonization by the caterpillars. Although no higher herbivory rates were noted, these caterpillars are ineffective in protecting their host trees from a pathogenic fungus, Fusarium moniliforme (Deuteromycetes), that develops on the trichilium in the absence of mutualistic ants. Therefore, the Cecropia treelets can be parasitized by two often overlooked species: the caterpillars that shelter in the domatia and feed on FBs, delaying colonization by mutualistic ants, and the fungal pathogen that develops on old trichilia. The cost of greater FB production plus the presence of the pathogenic fungus likely affect tree growth. PMID:21655182

  15. Caterpillars and fungal pathogens: two co-occurring parasites of an ant-plant mutualism.

    Directory of Open Access Journals (Sweden)

    Olivier Roux

    Full Text Available In mutualisms, each interacting species obtains resources from its partner that it would obtain less efficiently if alone, and so derives a net fitness benefit. In exchange for shelter (domatia and food, mutualistic plant-ants protect their host myrmecophytes from herbivores, encroaching vines and fungal pathogens. Although selective filters enable myrmecophytes to host those ant species most favorable to their fitness, some insects can by-pass these filters, exploiting the rewards supplied whilst providing nothing in return. This is the case in French Guiana for Cecropia obtusa (Cecropiaceae as Pseudocabima guianalis caterpillars (Lepidoptera, Pyralidae can colonize saplings before the installation of their mutualistic Azteca ants. The caterpillars shelter in the domatia and feed on food bodies (FBs whose production increases as a result. They delay colonization by ants by weaving a silk shield above the youngest trichilium, where the FBs are produced, blocking access to them. This probable temporal priority effect also allows female moths to lay new eggs on trees that already shelter caterpillars, and so to occupy the niche longer and exploit Cecropia resources before colonization by ants. However, once incipient ant colonies are able to develop, they prevent further colonization by the caterpillars. Although no higher herbivory rates were noted, these caterpillars are ineffective in protecting their host trees from a pathogenic fungus, Fusarium moniliforme (Deuteromycetes, that develops on the trichilium in the absence of mutualistic ants. Therefore, the Cecropia treelets can be parasitized by two often overlooked species: the caterpillars that shelter in the domatia and feed on FBs, delaying colonization by mutualistic ants, and the fungal pathogen that develops on old trichilia. The cost of greater FB production plus the presence of the pathogenic fungus likely affect tree growth.

  16. Antibacterial Activity of Garlic Extract Against some Pathogenic Animal Bacteria

    OpenAIRE

    M. Safithri; M. Bintang; M. Poeloengan

    2011-01-01

    The antimicrobial activity of garlic extract against Gram-positive and Gram-negative bacterial isolates was well studied. However, reports on antibacterial activity of garlic extract against some pathogenic bacteria in animals in Indonesia, are still limited. Therefore, the aim of this study was to evaluate the antibacterial activity of water and ethanol extracts of garlic against Salmonella typhimurium in chickens, and Streptococcus agalactie, Escherichia coli, and Staphylococcus aureus caus...

  17. Oxidative stress response to menadione and cumene hydroperoxide in the opportunistic fungal pathogen Candida glabrata

    Directory of Open Access Journals (Sweden)

    Mayra Cuéllar-Cruz

    2009-07-01

    Full Text Available Candida glabrata is an opportunistic fungal pathogen that can cause severe invasive infections and can evade phagocytic cell clearance. We are interested in understanding the virulence of this fungal pathogen, in particular its oxidative stress response. Here we investigated C. glabrata, Saccharomyces cerevisiae and Candida albicans responses to two different oxidants: menadione and cumene hydroperoxide (CHP. In log-phase, in the presence of menadione, C. glabrata requires Cta1p (catalase, while in a stationary phase (SP, Cta1p is dispensable. In addition, C. glabrata is less resistant to menadione than C. albicans in SP. The S. cerevisiae laboratory reference strain is less resistant to menadione than C. glabrata and C. albicans; however S. cerevisiaeclinical isolates (CIs are more resistant than the lab reference strain. Furthermore, S. cerevisiae CIs showed an increased catalase activity. Interestingly, in SP C. glabrata and S. cerevisiae are more resistant to CHP than C. albicans and Cta1p plays no apparent role in detoxifying this oxidant.

  18. Multicenter Outbreak of Infections by Saprochaete clavata, an Unrecognized Opportunistic Fungal Pathogen

    Science.gov (United States)

    Vaux, Sophie; Criscuolo, Alexis; Desnos-Ollivier, Marie; Diancourt, Laure; Tarnaud, Chloé; Vandenbogaert, Matthias; Brisse, Sylvain; Coignard, Bruno; Garcia-Hermoso, Dea; Blanc, Catherine; Hoinard, Damien; Lortholary, Olivier; Bretagne, Stéphane; Thiolet, Jean-Michel; de Valk, Henriette; Courbil, Rémi; Chabanel, Anne; Simonet, Marion; Maire, Francoise; Jbilou, Saadia; Tiberghien, Pierre; Blanchard, Hervé; Venier, Anne-Gaëlle; Bernet, Claude; Simon, Loïc; Sénéchal, Hélène; Pouchol, Elodie; Angot, Christiane; Ribaud, Patricia; Socié, G.; Flèche, M.; Brieu, Nathalie; Lagier, Evelyne; Chartier, Vanessa; Allegre, Thierry; Maulin, Laurence; Lanic, Hélène; Tilly, Hervé; Bouchara, Jean-Philippe; Pihet, Marc; Schmidt, Aline; Kouatchet, Achille; Vandamme, Yves-Marie; Ifrah, Norbert; Mercat, Alain; Accoceberry, Isabelle; Albert, Olivier; Leguay, Thibaut; Rogues, Anne-Marie; Bonhomme, Julie; Reman, Oumédaly; Lesteven, Claire; Poirier, Philippe; Chabrot, Cécile Molucon; Calvet, Laure; Baud, Olivier; Cambon, Monique; Farkas, Jean Chistophe; Lafon, Bruno; Dalle, Frédéric; Caillot, Denis; Lazzarotti, Aline; Aho, Serge; Combret, Sandrine; Facon, Thierry; Sendid, Boualem; Loridant, Séverine; Louis, Terriou; Cazin, Bruno; Grandbastien, Bruno; Bourgeois, Nathalie; Lotthé, Anne; Cartron, Guillaume; Ravel, Christophe; Colson, Pascal; Gaudard, Philippe; Bonmati, Caroline; Simon, Loic; Rabaud, Christian; Machouart, Marie; Poisson, Didier; Carp, Diana; Meunier, Jérôme; Gaschet, Anne; Miquel, Chantal; Sanhes, Laurence; Ferreyra, Milagros; Leibinger, Franck; Geudet, Philippe; Toubas, Dominique; Himberlin, Chantal; Bureau-Chalot, Florence; Delmer, Alain; Favennec, Loïc; Gargala, Gilles; Michot, Jean-Baptiste; Girault, Christophe; David, Marion; Leprêtre, Stéphane; Jardin, Fabrice; Honderlick, Pierre; Caille, Vincent; Cerf, Charles; Cassaing, Sophie; Recher, Christian; Picard, Muriel; Protin, Caroline; Huguet, Françoise; Huynh, Anne; Ruiz, Jean; Riu-Poulenc, Béatrice; Letocart, Philippe; Marchou, Bruno; Verdeil, Xavier; Cavalié, Laurent; Chauvin, Pamela; Iriart, Xavier; Valentin, Alexis; Bouvet, Emmanuelle; Delmas-Marsalet, Béatrice; Jeblaoui, Asma; Kassis-Chikhani, Najiby; Mühlethaler, Konrad; Zimmerli, Stefan; Zalar, Polona; Sánchez-Reus, Ferran; Gurgui, Merce

    2014-01-01

    ABSTRACT Rapidly fatal cases of invasive fungal infections due to a fungus later identified as Saprochaete clavata were reported in France in May 2012. The objectives of this study were to determine the clonal relatedness of the isolates and to investigate possible sources of contamination. A nationwide alert was launched to collect cases. Molecular identification methods, whole-genome sequencing (WGS), and clone-specific genotyping were used to analyze recent and historical isolates, and a case-case study was performed. Isolates from thirty cases (26 fungemias, 22 associated deaths at day 30) were collected between September 2011 and October 2012. Eighteen cases occurred within 8 weeks (outbreak) in 10 health care facilities, suggesting a common source of contamination, with potential secondary cases. Phylogenetic analysis identified one clade (clade A), which accounted for 16/18 outbreak cases. Results of microbiological investigations of environmental, drug, or food sources were negative. Analysis of exposures pointed to a medical device used for storage and infusion of blood products, but no fungal contamination was detected in the unused devices. Molecular identification of isolates from previous studies demonstrated that S. clavata can be found in dairy products and has already been involved in monocentric outbreaks in hematology wards. The possibility that S. clavata may transmit through contaminated medical devices or can be associated with dairy products as seen in previous European outbreaks is highly relevant for the management of future outbreaks due to this newly recognized pathogen. This report also underlines further the potential of WGS for investigation of outbreaks due to uncommon fungal pathogens. PMID:25516620

  19. Dissecting the molecular interactions between wheat and the fungal pathogen Zymoseptoria tritici

    Directory of Open Access Journals (Sweden)

    Graeme James Kettles

    2016-04-01

    Full Text Available The Dothideomycete fungus Zymoseptoria tritici (previously known as Mycosphaerella graminicola and Septoria tritici is the causative agent of Septoria tritici leaf blotch (STB disease of wheat (Triticum aestivum L.. In Europe, STB is the most economically damaging disease of wheat, with an estimated ~€1 billion per year in fungicide expenditure directed towards its control. Here, an overview of our current understanding of the molecular events that occur during Z. tritici infection of wheat leaves is presented. On the host side, this includes the contribution of (1 the pathogen-associated molecular pattern-triggered immunity (PTI layer of the plant defence, and (2 major Stb resistance loci to Z. tritici resistance. On the pathogen side of the interaction, we consolidate evidence from recent bioinformatic, transcriptomic and proteomic studies that begin to explain the contribution of Z. tritici effector proteins to the biphasic lifestyle of the fungus. This includes the discovery of chitin-binding proteins in the Z. tritici secretome, which contribute to evasion of immune surveillance by this pathogen, and the possible existence of ‘necrotrophic’ effectors from Z. tritici, which may actively stimulate host recognition in a manner similar to related necrotrophic fungal pathogens. We finish by speculating on how some of these recent fundamental discoveries might be harnessed to help improve resistance to STB in the world’s second largest food crop.

  20. Genome-Wide Host-Pathogen Interaction Unveiled by Transcriptomic Response of Diamondback Moth to Fungal Infection.

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    Zhen-Jian Chu

    Full Text Available Genome-wide insight into insect pest response to the infection of Beauveria bassiana (fungal insect pathogen is critical for genetic improvement of fungal insecticides but has been poorly explored. We constructed three pairs of transcriptomes of Plutella xylostella larvae at 24, 36 and 48 hours post treatment of infection (hptI and of control (hptC for insight into the host-pathogen interaction at genomic level. There were 2143, 3200 and 2967 host genes differentially expressed at 24, 36 and 48 hptI/hptC respectively. These infection-responsive genes (~15% of the host genome were enriched in various immune processes, such as complement and coagulation cascades, protein digestion and absorption, and drug metabolism-cytochrome P450. Fungal penetration into cuticle and host defense reaction began at 24 hptI, followed by most intensive host immune response at 36 hptI and attenuated immunity at 48 hptI. Contrastingly, 44% of fungal genes were differentially expressed in the infection course and enriched in several biological processes, such as antioxidant activity, peroxidase activity and proteolysis. There were 1636 fungal genes co-expressed during 24-48 hptI, including 116 encoding putative secretion proteins. Our results provide novel insights into the insect-pathogen interaction and help to probe molecular mechanisms involved in the fungal infection to the global pest.

  1. Antifungal Screening of Lavender Essential oils and Essential Oil Constituents on three Post-harvest Fungal Pathogens.

    Science.gov (United States)

    Erland, Lauren A E; Bitcon, Christopher R; Lemke, Ashley D; Mahmoud, Soheil S

    2016-04-01

    A growing body of literature indicates that many synthetic pesticides have adverse effects on human, animal, and environmental health. As a result, plant-derived natural products are quickly gaining momentum as safer and less ecologically damaging alternatives due to their low toxicity, high biodegradability, and good specificity. Essential oils of Lavandula angustifolia, Lavandula x intermedia cv Grosso, and Lavandida x intermedia cv Provence as well as various mono- and sesquiterpene essential oil constituents were tested in order to assess their antifungal potential on three important agricultural pathogens: Botrytis cinerea, Mucor piriformis, and Penicillium expansum. Fungal susceptibility testing was performed using disk diffusion assays. The majority of essential oil constituents tested did not have a significant effect; however, 3-carene, carvacrol, geraniol, nerol and perillyl alcohol demonstrated significant inhibition at concentrations as low as 1 µ/mL. In vivo testing using strawberry fruit as a model system supported in vitro results and revealed that perillyl alcohol, carvacrol and 3-carene were effective in limiting infection by postharvest pathogens. PMID:27396210

  2. Nucleic Acid-Based Detection and Identification of Bacterial and Fungal Plant Pathogens - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kingsley, Mark T.

    2001-03-13

    The threat to American interests from terrorists is not limited to attacks against humans. Terrorists might seek to inflict damage to the U.S. economy by attacking our agricultural sector. Infection of commodity crops by bacterial or fungal crop pathogens could adversely impact U.S. agriculture, either directly from damage to crops or indirectly from damage to our ability to export crops suspected of contamination. Recognizing a terrorist attack against U.S. agriculture, to be able to prosecute the terrorists, is among the responsibilities of the members of Hazardous Material Response Unit (HMRU) of the Federal Bureau of Investigation (FBI). Nucleic acid analysis of plant pathogen strains by the use of polymerase chain reaction (PCR) amplification techniques is a powerful method for determining the exact identity of pathogens, as well as their possible region of origin. This type of analysis, however, requires that PCR assays be developed specific to each particular pathogen strain, and analysis protocols developed that are specific to the particular instrument used for detection. The objectives of the work described here were threefold: 1) to assess the potential terrorist threat to U.S. agricultural crops, 2) to determine whether suitable assays exist to monitor that threat, and 3) where assays are needed for priority plant pathogen threats, to modify or develop those assays for use by specialists at the HMRU. The assessment of potential threat to U.S. commodity crops and the availability of assays for those threats were described in detail in the Technical Requirements Document (9) and will be summarized in this report. This report addresses development of specific assays identified in the Technical Requirements Document, and offers recommendations for future development to ensure that HMRU specialists will be prepared with the PCR assays they need to protect against the threat of economic terrorism.

  3. Fungal trunk pathogens associated with wood decay of pistachio trees in Iran

    Directory of Open Access Journals (Sweden)

    Hamid Mohammadi

    2015-06-01

    Full Text Available Over the growing seasons of 2011–2013, various pistachio (Pistacia vera L. cv. Fandoghi, and wild pistachio (P. atlantica Desf. subsp. mutica trees were inspected in Iran to determine the aetiology of trunk diseases with specific reference to species of Phaeoacremonium and Botryosphaeriaceae spp. Samples were collected from branches of trees exhibiting yellowing, defoliation, canker and dieback, as well as wood discoloration in cross sections. Fungal trunk pathogens were identified using morphological and cultural characteristics as well as comparisons of DNA sequence data of the ITS and TEF-1α (for Botryosphaeriaceae species and β-tubulin gene (for Phaeoacremonium species regions. Phaeoacremonium parasiticum was the dominant species followed by Phaeoacremonium aleophilum, Botryosphaeria dothidea, Neofusicoccum parvum, Phaeoacremoniumcinereum, Phaeoacremonium viticola and Dothiorella viticola. Pathogenicity tests were undertaken to determine the role of these species on pistachio under field conditions. Neofusicoccum parvum and Pm. aleophilum caused the longest and smallest lesions respectively. This study represents the first report on the occurrence and pathogenicity of Phaeoacremonium species on P. vera cv. Fandoghi. This also represents the first report of Pleurostomophora sp. on pistachio and Pm. parasiticum and D. viticola on wild pistachio.

  4. Comparative Transcriptome Analysis between the Fungal Plant Pathogens Sclerotinia sclerotiorum and S. trifoliorum Using RNA Sequencing.

    Science.gov (United States)

    Qiu, Dan; Xu, Liangsheng; Vandemark, George; Chen, Weidong

    2016-03-01

    The fungal plant pathogens Sclerotinia sclerotiorum and S. trifoliorum are morphologically similar, but differ considerably in host range. In an effort to elucidate mechanisms of the host range difference, transcriptomes of the 2 species at vegetative growth stage were compared to gain further insight into commonality and uniqueness in gene expression and pathogenic mechanisms of the 2 closely related pathogens. A total of 23133 and 21043 unique transcripts were obtained from S. sclerotiorum and S. trifoliorum, respectively. Approximately 43% of the transcripts were genes with known functions for both species. Among 1411 orthologous contigs, about 10% (147) were more highly (>3-fold) expressed in S. trifoliorum than in S. sclerotiorum, and about 12% (173) of the orthologs were more highly (>3-fold) expressed in S. sclerotiorum than in S. trifoliorum. The expression levels of genes on the supercontig 30 have the highest correlation coefficient value between the 2 species. Twenty-seven contigs were found to be new and unique for S. trifoliorum. Additionally, differences in expressed genes involved in pathogenesis like oxalate biosynthesis and endopolygalacturonases were detected between the 2 species. The analyses of the transcriptomes not only discovered similarities and uniqueness in gene expression between the 2 closely related species, providing additional information for annotation the S. sclerotiorum genome, but also provided foundation for comparing the transcriptomes with host-infecting transcriptomes.

  5. Regulation of secondary metabolite production in the fungal tomato pathogen Cladosporium fulvum.

    Science.gov (United States)

    Griffiths, Scott; Saccomanno, Benedetta; de Wit, Pierre J G M; Collemare, Jérôme

    2015-11-01

    Cladosporium fulvum is a non-obligate biotrophic fungal tomato pathogen for which fifteen secondary metabolite (SM) gene clusters were previously identified in its genome. However, most of these SM biosynthetic pathways remain cryptic during growth in planta and in different in vitro conditions. The sole SM produced in vitro is the pigment cladofulvin. In this study, we attempted to activate cryptic pathways in order to identify new compounds produced by C. fulvum. For this purpose, we manipulated orthologues of the global regulators VeA, LaeA and HdaA known to regulate SM biosynthesis in other fungal species. In C. fulvum, deleting or over-expressing these regulators yielded no new detectable SMs. Yet, quantification of cladofulvin revealed that CfHdaA is an activator whilst CfVeA and CfLaeA seemed to act as repressors of cladofulvin production. In the wild type strain, cladofulvin biosynthesis was affected by the carbon source, with highest production under carbon limitation and traces only in presence of saccharose. Repression of cladofulvin production by saccharose was dependent on both CfVeA and CfLaeA. Deletion of CfVeA or CfLaeA caused production of sterile mycelia, whilst Δcfhdaa deletion mutants sporulated, suggesting that cladofulvin production is not linked to asexual reproduction. Profiling the transcription of these regulators showed that CfHdaA-mediated regulation of cladofulvin production is independent of both CfVeA and CfLaeA. Our data suggest CfLaeA directly affects cladofulvin production whilst the effect of CfVeA is indirect, suggesting a role for CfLaeA outside of the Velvet complex. In conclusion, our results showed that regulation of SM production in C. fulvum is different from other fungi and indicate that manipulation of global regulators is not a universal tool to discover new fungal natural products.

  6. Miro GTPase controls mitochondrial behavior affecting stress tolerance and virulence of a fungal insect pathogen.

    Science.gov (United States)

    Guan, Yi; Wang, Ding-Yi; Ying, Sheng-Hua; Feng, Ming-Guang

    2016-08-01

    Miro homologues are small mitochondrial Rho GTPases belonging to the Ras superfamily across organisms and are generally unexplored in filamentous fungi. Here we identified a Miro orthologue (bMiro) in Beauveria bassiana, a filamentous fungal insect pathogen as a classic biological control agent of insect pests. This orthologue was proven to anchor on mitochondrial outer membrane in a manner depending completely upon a short C-terminal transmembrane domain. As a result of bmiro deletion, mitochondria in hyphal cells were largely aggregated, and their mass and mobility were reduced, accompanied with a remarkable decrease in ATP content but little change in mitochondrial morphology. The deletion mutant became 42%, 37%, 19% and 10% more tolerant to Ca(2+), Mn(2+), Zn(2+) and Mg(2+) than wild-type, respectively, during cultivation in a minimal medium under normal conditions. The deletion mutant also showed mild defects in conidial germination, vegetative growth, thermotolerance, UV-B resistance and virulence despite null response to oxidative and osmotic stresses. All these phenotypic changes were restored by targeted gene complementation. Our results indicate that bMiro can control mitochondrial distribution and movement required for the transport of ATP-form energy and metal ions and contributes significantly to the fungal potential against insect pests through the control. PMID:27241960

  7. Tissue specific localization of root infection by fungal pathogens: role of root border cells.

    Science.gov (United States)

    Gunawardena, Uvini; Hawes, Martha C

    2002-11-01

    When roots of pea seedlings were inoculated uniformly with spores of Nectria haematocca or other pea pathogenic fungi, more than 90% developed lesions in the region of elongation within 3 days. More mature regions of most roots as well as the tip showed no visible signs of infection. Yet, microscopic observation revealed that 'mantles,' comprised of fungal hyphae intermeshed with populations of border cells, covered the tips of most roots. After physical detachment of the mantle, the underlying tip of most roots was found to be free of infection. Mantle-covered root tips did not respond to invasion of their border cells by activation of known defense genes unless there was invasion of the tip itself, as revealed by the presence of a lesion. Concomitant with the activation of defense genes was the induction of a cell-wall degrading enzyme whose expression is a marker for renewed production of border cells. Mantle formation did not occur in response to nonpathogens. The data are consistent with the hypothesis that border cells serve as a host-specific 'decoy' that protects root meristems by inhibiting fungal infection of the root tip.

  8. Biocontrol of Phytophthora infestans, Fungal Pathogen of Seedling Damping Off Disease in Economic Plant Nursery

    Directory of Open Access Journals (Sweden)

    B. Loliam

    2012-01-01

    Full Text Available This research aims to control Seedling damping off disease in plants by using antagonistic actinomycetes against the causative fungi. Phytophthora infestans was isolated from the infected tomato plant seedling obtained from an economic plant nursery in Amphoe Pak Chong, Nakhon Ratchasima Province, Thailand. The chitinolytic Streptomyces rubrolavendulae S4, isolated from termite mounds at the grove of Amphoe Si-Sawat, Kanchanaburi Province, Thailand, was proven to be the most effective growth inhibition of fungal pathogens tested on potato dextrose agar. Tomato and chili seedlings that colonized with antagonistic S. rubrolavendulae S4 were grown in P. infestans artificial inoculated peat moss. Percents of noninfested seedling in fungal contaminated peat moss were compared to the controls with uninoculated peat moss. In P. infestans contaminated peat moss, the percents of survival of tomato and chili seedling were significantly increased (0.05. It was clearly demonstrated that S. rubrolavendulae S4 can prevent the tomato and chili seedling damping off disease in economic plant nurseries.

  9. Evaluation of two conservation methods of filamentous fungal oil palm pathogens

    Directory of Open Access Journals (Sweden)

    Oscar Eduardo Ladino Rey

    2016-07-01

    Full Text Available Research about filamentous fungal oil palm pathogens is as essential for the maintenance and the sustainability of the crop as the conservation of these identified fungi itself because it allows its uses for former researches or as a guide for identify fungi through time. The purpose of this study was to evaluate two methods of conservation, one of them in three times sterilized distilled water (ADTE and with Glicerol 10 %. By four months, with a monthly review of fungi isolated from plant tissue palm oil affected by Aspergillus sp., Chrysosporium sp., Curvularia sp., Fusarium sp., Penicillium sp. and Rhizopus sp. Six of the seven fungi strains conserved were successfully recovered from the Treatment with Glicerol 10 %, while five of the seven strains conserved ADTE were recovered after the four evaluation months of this study.

  10. Azole fungicides - understanding resistance mechanisms in agricultural fungal pathogens.

    Science.gov (United States)

    Price, Claire L; Parker, Josie E; Warrilow, Andrew G S; Kelly, Diane E; Kelly, Steven L

    2015-08-01

    Plant fungal pathogens can have devastating effects on a wide range of crops, including cereals and fruit (such as wheat and grapes), causing losses in crop yield, which are costly to the agricultural economy and threaten food security. Azole antifungals are the treatment of choice; however, resistance has arisen against these compounds, which could lead to devastating consequences. Therefore, it is important to understand how these fungicides are used and how the resistance arises in order to tackle the problem fully. Here, we give an overview of the problem and discuss the mechanisms that mediate azole resistance in agriculture (point mutations in the CYP51 amino acid sequence, overexpression of the CYP51 enzyme and overexpression of genes encoding efflux pump proteins). © 2015 Society of Chemical Industry. PMID:25914201

  11. Azole fungicides - understanding resistance mechanisms in agricultural fungal pathogens.

    Science.gov (United States)

    Price, Claire L; Parker, Josie E; Warrilow, Andrew G S; Kelly, Diane E; Kelly, Steven L

    2015-08-01

    Plant fungal pathogens can have devastating effects on a wide range of crops, including cereals and fruit (such as wheat and grapes), causing losses in crop yield, which are costly to the agricultural economy and threaten food security. Azole antifungals are the treatment of choice; however, resistance has arisen against these compounds, which could lead to devastating consequences. Therefore, it is important to understand how these fungicides are used and how the resistance arises in order to tackle the problem fully. Here, we give an overview of the problem and discuss the mechanisms that mediate azole resistance in agriculture (point mutations in the CYP51 amino acid sequence, overexpression of the CYP51 enzyme and overexpression of genes encoding efflux pump proteins). © 2015 Society of Chemical Industry.

  12. Pathogenic Yet Environmentally Friendly? Black Fungal Candidates for Bioremediation of Pollutants

    Science.gov (United States)

    Blasi, Barbara; Poyntner, Caroline; Rudavsky, Tamara; Prenafeta-Boldú, Francesc X.; Hoog, Sybren De; Tafer, Hakim; Sterflinger, Katja

    2016-01-01

    ABSTRACT A collection of 163 strains of black yeast-like fungi from the CBS Fungal Biodiversity Center (Utrecht, The Netherlands), has been screened for the ability to grow on hexadecane, toluene and polychlorinated biphenyl 126 (PCB126) as the sole carbon and energy source. These compounds were chosen as representatives of relevant environmental pollutants. A microtiter plate-based culture assay was set up in order to screen the fungal strains for growth on the selected xenobiotics versus glucose, as a positive control. Growth was observed in 25 strains on at least two of the tested substrates. Confirmation of substrate assimilation was performed by cultivation on closed vials and analysis of the headspace composition with regard to the added volatile substrates and the generated carbon dioxide. Exophiala mesophila (CBS 120910) and Cladophialophora immunda (CBS 110551), both of the order Chaetothyriales and isolated from a patient with chronic sinusitis and a polluted soil sample, respectively, showed the ability to grow on toluene as the sole carbon and energy source. Toluene assimilation has previously been described for C. immunda but this is the first account for E. mesophila. Also, this is the first time that the capacity to grow on alkylbenzenes has been demonstrated for a clinical isolate. Assimilation of toluene could not be demonstrated for the human opportunistic pathogen Pseudoallescheria boydii (CBS 115.59, Microascales), but the results from microtiter plate assays suggest that strains of this species are promising candidates for further studies. The outstanding abilities of black yeast-like fungi to thrive in extreme environments makes them ideal agents for the bioremediation of polluted soils, and for the treatment of contaminated gas streams in biofilters. However, interrelations between hydrocarbonoclastic and potentially pathogenic strains need to be elucidated in order to avoid the possibility of biohazards occurring. PMID:27019541

  13. Predicting invasive fungal pathogens using invasive pest assemblages: testing model predictions in a virtual world.

    Directory of Open Access Journals (Sweden)

    Dean R Paini

    Full Text Available Predicting future species invasions presents significant challenges to researchers and government agencies. Simply considering the vast number of potential species that could invade an area can be insurmountable. One method, recently suggested, which can analyse large datasets of invasive species simultaneously is that of a self organising map (SOM, a form of artificial neural network which can rank species by establishment likelihood. We used this method to analyse the worldwide distribution of 486 fungal pathogens and then validated the method by creating a virtual world of invasive species in which to test the SOM. This novel validation method allowed us to test SOM's ability to rank those species that can establish above those that can't. Overall, we found the SOM highly effective, having on average, a 96-98% success rate (depending on the virtual world parameters. We also found that regions with fewer species present (i.e. 1-10 species were more difficult for the SOM to generate an accurately ranked list, with success rates varying from 100% correct down to 0% correct. However, we were able to combine the numbers of species present in a region with clustering patterns in the SOM, to further refine confidence in lists generated from these sparsely populated regions. We then used the results from the virtual world to determine confidences for lists generated from the fungal pathogen dataset. Specifically, for lists generated for Australia and its states and territories, the reliability scores were between 84-98%. We conclude that a SOM analysis is a reliable method for analysing a large dataset of potential invasive species and could be used by biosecurity agencies around the world resulting in a better overall assessment of invasion risk.

  14. Predicting Invasive Fungal Pathogens Using Invasive Pest Assemblages: Testing Model Predictions in a Virtual World

    Science.gov (United States)

    Paini, Dean R.; Bianchi, Felix J. J. A.; Northfield, Tobin D.; De Barro, Paul J.

    2011-01-01

    Predicting future species invasions presents significant challenges to researchers and government agencies. Simply considering the vast number of potential species that could invade an area can be insurmountable. One method, recently suggested, which can analyse large datasets of invasive species simultaneously is that of a self organising map (SOM), a form of artificial neural network which can rank species by establishment likelihood. We used this method to analyse the worldwide distribution of 486 fungal pathogens and then validated the method by creating a virtual world of invasive species in which to test the SOM. This novel validation method allowed us to test SOM's ability to rank those species that can establish above those that can't. Overall, we found the SOM highly effective, having on average, a 96–98% success rate (depending on the virtual world parameters). We also found that regions with fewer species present (i.e. 1–10 species) were more difficult for the SOM to generate an accurately ranked list, with success rates varying from 100% correct down to 0% correct. However, we were able to combine the numbers of species present in a region with clustering patterns in the SOM, to further refine confidence in lists generated from these sparsely populated regions. We then used the results from the virtual world to determine confidences for lists generated from the fungal pathogen dataset. Specifically, for lists generated for Australia and its states and territories, the reliability scores were between 84–98%. We conclude that a SOM analysis is a reliable method for analysing a large dataset of potential invasive species and could be used by biosecurity agencies around the world resulting in a better overall assessment of invasion risk. PMID:22016773

  15. Pathogenicity of Cryptosporidium parvum - evaluation of an animal infection model

    DEFF Research Database (Denmark)

    Enemark, Heidi L.; Bille-Hansen, Vivi; Lind, Peter;

    2003-01-01

    and rectum. The unintended presence of rotavirus in some of the experimental animals revealed an additive or synergistic effect between rotavirus and C. parvum as indicated by prolonged diarrhoea, increased oocyst shedding, decreased weight gain and elevated levels of serum haptoglobin and serum amyloid...... A (SAA) in piglets infected simultaneously with both pathogens. The difference in daily weight gain between infected and control animals was significant only for piglets co-infected with rotavirus. The acute phase response of haptoglobin and SAA was characterised by a large individual variation....... In piglets, co-infected with rotavirus, the levels of serum haptoglobin were 3.5 and 4.6 times higher in the infected versus the controls 6 and 9 dpi, respectively (mean values: 2411 mug/ml +/- S.D. 2023 and 1840 mug/ml +/- S.D. 1697). In the controls infected with rotavirus, peak haptoglobin concentration...

  16. Mutations at the Asc locus of tomato confer resistance to the fungal pathogen Alternaria alternata f. sp. lycopersici

    NARCIS (Netherlands)

    Biezen, E.A. van der; Nijkamp, H.J.J.; Hille, J.

    1996-01-01

    The fungal pathogen Alternaria alternata f. sp. lycopersici produces host-selective AAL-toxins that cause Alternaria stem canker in tomato. Susceptibility to the disease is based on the relative sensitivity of the host to the AAL-toxins and is controlled by the Asc locus on chromosome 3L. Chemical m

  17. Emerging trends in molecular interactions between plants and the broad host range fungal pathogens Botrytis cinerea and Sclerotinia sclerotiorum

    Directory of Open Access Journals (Sweden)

    Malick eMbengue

    2016-03-01

    Full Text Available Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum , the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi.

  18. Isolation from the Sorghum bicolor Mycorrhizosphere of a Bacterium Compatible with Arbuscular Mycorrhiza Development and Antagonistic towards Soilborne Fungal Pathogens

    Science.gov (United States)

    Budi, S. W.; van Tuinen, D.; Martinotti, G.; Gianinazzi, S.

    1999-01-01

    A gram-positive bacterium with antagonistic activity towards soilborne fungal pathogens has been isolated from the mycorrhizosphere of Sorghum bicolor inoculated with Glomus mosseae. It has been identified as Paenibacillus sp. strain B2 based on its analytical profile index and on 16S ribosomal DNA analysis. Besides having antagonistic activity, this bacterium stimulates mycorrhization. PMID:10543835

  19. Emerging Trends in Molecular Interactions between Plants and the Broad Host Range Fungal Pathogens Botrytis cinerea and Sclerotinia sclerotiorum.

    Science.gov (United States)

    Mbengue, Malick; Navaud, Olivier; Peyraud, Rémi; Barascud, Marielle; Badet, Thomas; Vincent, Rémy; Barbacci, Adelin; Raffaele, Sylvain

    2016-01-01

    Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum, the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi. PMID:27066056

  20. Experimental verification and molecular basis of active immunization against fungal pathogens in termites.

    Science.gov (United States)

    Liu, Long; Li, Ganghua; Sun, Pengdong; Lei, Chaoliang; Huang, Qiuying

    2015-10-13

    Termites are constantly exposed to many pathogens when they nest and forage in the field, so they employ various immune strategies to defend against pathogenic infections. Here, we demonstrate that the subterranean termite Reticulitermes chinensis employs active immunization to defend against the entomopathogen Metarhizium anisopliae. Our results showed that allogrooming frequency increased significantly between fungus-treated termites and their nestmates. Through active social contact, previously healthy nestmates only received small numbers of conidia from fungus-treated individuals. These nestmates experienced low-level fungal infections, resulting in low mortality and apparently improved antifungal defences. Moreover, infected nestmates promoted the activity of two antioxidant enzymes (SOD and CAT) and upregulated the expression of three immune genes (phenoloxidase, transferrin, and termicin). We found 20 differentially expressed proteins associated with active immunization in R. chinensis through iTRAQ proteomics, including 12 stress response proteins, six immune signalling proteins, and two immune effector molecules. Subsequently, two significantly upregulated (60S ribosomal protein L23 and isocitrate dehydrogenase) and three significantly downregulated (glutathione S-transferase D1, cuticle protein 19, and ubiquitin conjugating enzyme) candidate immune proteins were validated by MRM assays. These findings suggest that active immunization in termites may be regulated by different immune proteins.

  1. The gray phenotype and tristable phenotypic transitions in the human fungal pathogen Candida tropicalis.

    Science.gov (United States)

    Zhang, Yulong; Tao, Li; Zhang, Qiuyu; Guan, Guobo; Nobile, Clarissa J; Zheng, Qiushi; Ding, Xuefen; Huang, Guanghua

    2016-08-01

    Phenotypic plasticity, the ability to switch between different morphological types, plays critical roles in environmental adaptation, leading to infections, and allowing for sexual reproduction in pathogenic Candida species. Candida tropicalis, which is both an emerging human fungal pathogen and an environmental fungus, can switch between two heritable cell types termed white and opaque. In this study, we report the discovery of a novel phenotype in C. tropicalis, named the gray phenotype. Similar to Candida albicans and Candida dubliniensis, white, gray, and opaque cell types of C. tropicalis also form a tristable switching system, where gray cells are relatively small and elongated. In C. tropicalis, gray cells exhibit intermediate levels of mating competency and virulence in a mouse systemic infection model compared to the white and opaque cell types, express a set of cell type-enriched genes, and exhibit both common and species-specific biological features. The key regulators of white-opaque transitions, Wor1 and Efg1, are not required for the gray phenotype. A comparative study of the gray phenotypes in C. tropicalis, C. albicans, and C. dubliniensis provides clues to explain the virulence properties and niche preferences of C. tropicalis. PMID:27246518

  2. Soil fungal pathogens and the relationship between plant diversity and productivity.

    Science.gov (United States)

    Maron, John L; Marler, Marilyn; Klironomos, John N; Cleveland, Cory C

    2011-01-01

    One robust result from many small-scale experiments has been that plant community productivity often increases with increasing plant diversity. Most frequently, resource-based or competitive interactions are thought to drive this positive diversity-productivity relationship. Here, we ask whether suppression of plant productivity by soil fungal pathogens might also drive a positive diversity-productivity relationship. We created plant assemblages that varied in diversity and crossed this with a ± soil fungicide treatment. In control (non-fungicide treated) assemblages there was a strong positive relationship between plant diversity and above-ground plant biomass. However, in fungicide-treated assemblages this relationship disappeared. This occurred because fungicide increased plant production by an average of 141% at the lower ends of diversity but boosted production by an average of only 33% at the higher ends of diversity, essentially flattening the diversity-productivity curve. These results suggest that soil pathogens might be a heretofore unappreciated driver of diversity-productivity relationships. PMID:21073641

  3. Studies on antimicrobial and antifungal activities of ziziphus mauritiana human clinical bacterial and fungal pathogens

    International Nuclear Information System (INIS)

    The antimicrobial and antifungal activities of crude extracts of Ziziphus mauritiana leaves were investigated against six selected bacterial (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa, Enterobacter, Klebsiella pneumoniae) and one fungal pathogen (Aspel-gillus niger). The crude extract was further fractionated in butanol, choloroform, n-hexane and methanol. Agar well diffusion and agar dilution assay were employed for determination of zones of inhibition and MICs, respectively, whereas MBC was determined using broth dilution test. The butanol fraction presented encouraging antimicrobial activity (15.0%0.02), while methanol (7.03:1:0.05) and chloroform (7.0%0,05) fractions emerged with significantly low susceptibility. The n-hexane fraction was recorded as almost inactive (0%0) against all bacterial pathogens. Unlike the antibacterial activities, all fractions possessed momentous antifungal activities except the methanol fraction (0%0). The n-hexane fraction showed widest zone of inhibition (11:1:0.05) followed by butanol (8.0%0.02) and chloroform (7.0%0.02). (author)

  4. Prebiotics in food animals: A potential to reduce foodborne pathogens and disease

    Science.gov (United States)

    Animals can be seriously impacted by bacterial pathogens that affect their growth efficiency and overall health, as well as food safety of animal-derived products. Some pathogenic bacteria, such as Salmonella, can be a shared problem for both human and animal health and can be found in many animal ...

  5. Prebiotics in food animals, a potential to reduce foodborne pathogens and disease

    Science.gov (United States)

    Animals can be seriously impacted by bacterial pathogens that affect their growth efficiency and overall health, as well as food safety of animal-derived products. Some pathogenic bacteria, such as Salmonella, can be a shared problem for both human and animal health and can be found in many animal ...

  6. A rock-inhabiting ancestor for mutualistic and pathogen-rich fungal lineages

    Science.gov (United States)

    Gueidan, C.; Villaseñor, C. R.; de Hoog, G. S.; Gorbushina, A. A.; Untereiner, W. A.; Lutzoni, F.

    2008-01-01

    Rock surfaces are unique terrestrial habitats in which rapid changes in the intensity of radiation, temperature, water supply and nutrient availability challenge the survival of microbes. A specialised, but diverse group of free-living, melanised fungi are amongst the persistent settlers of bare rocks. Multigene phylogenetic analyses were used to study relationships of ascomycetes from a variety of substrates, with a dataset including a broad sampling of rock dwellers from different geographical locations. Rock-inhabiting fungi appear particularly diverse in the early diverging lineages of the orders Chaetothyriales and Verrucariales. Although these orders share a most recent common ancestor, their lifestyles are strikingly different. Verrucariales are mostly lichen-forming fungi, while Chaetothyriales, by contrast, are best known as opportunistic pathogens of vertebrates (e.g. Cladophialophora bantiana and Exophiala dermatitidis, both agents of fatal brain infections) and saprophytes. The rock-dwelling habit is shown here to be key to the evolution of these two ecologically disparate orders. The most recent common ancestor of Verrucariales and Chaetothyriales is reconstructed as a non-lichenised rock-inhabitant. Ancestral state reconstructions suggest Verrucariales as one of the independent ascomycetes group where lichenisation has evolved on a hostile rock surface that might have favored this shift to a symbiotic lifestyle. Rock-inhabiting fungi are also ancestral to opportunistic pathogens, as they are found in the early diverging lineages of Chaetothyriales. In Chaetothyriales and Verrucariales, specific morphological and physiological traits (here referred to as extremotolerance) evolved in response to stresses in extreme conditions prevailing on rock surfaces. These factors facilitated colonisation of various substrates including the brains of vertebrates by opportunistic fungal pathogens, as well as helped establishment of a stable lichen symbiosis. PMID

  7. Invasive fungal infections in neutropenic enterocolitis: A systematic analysis of pathogens, incidence, treatment and mortality in adult patients

    Directory of Open Access Journals (Sweden)

    Pauls Katharina

    2006-02-01

    Full Text Available Abstract Background Neutropenic enterocolitis is a life-threatening complication most frequently occurring after intensive chemotherapy in acute leukaemias. Gramnegative bacteria constitute the most important group of causative pathogens. Fungi have also been reported, but their practical relevance remains unclear. The guidelines do not address concrete treatment recommendations for fungal neutropenic enterocolitis. Methods Here, we conducted a metaanalysis to answer the questions: What are frequency and mortality of fungal neutropenic enterocolitis? Do frequencies and microbiological distribution of causative fungi support empirical antimycotic therapy? Do reported results of antimycotic therapy in documented fungal neutropenic enterocolitis help with the selection of appropriate drugs? Following a systematic search, we extracted and summarised all detail data from the complete literature. Results Among 186 articles describing patients with neutropenic enterocolitis, we found 29 reports describing 53 patients with causative fungal pathogens. We found no randomised controlled trial, no good quality cohort study and no good quality case control study on the role of antifungal treatment. The pooled frequency of fungal neutropenic enterocolitis was 6.2% calculated from all 860 reported patients and 3.4% calculated from selected representative studies only. In 94% of the patients, Candida spp. were involved. The pooled mortality rate was 81.8%. Most authors did not report or perform antifungal therapy. Conclusion In patients with neutropenic enterocolitis, fungal pathogens play a relevant, but secondary role compared to bacteria. Evidence concerning therapy is very poor, but epidemiological data from this study may provide helpful clues to select empiric antifungal therapy in neutropenic enterocolitis.

  8. Rapid detection of fungal pathogens in bronchoalveolar lavage samples using panfungal PCR combined with high resolution melting analysis.

    Science.gov (United States)

    Bezdicek, Matej; Lengerova, Martina; Ricna, Dita; Weinbergerova, Barbora; Kocmanova, Iva; Volfova, Pavlina; Drgona, Lubos; Poczova, Miroslava; Mayer, Jiri; Racil, Zdenek

    2016-10-01

    Despite advances in the treatment of invasive fungal diseases (IFD), mortality rates remain high. Moreover, due to the expanding spectrum of causative agents, fast and accurate pathogen identification is necessary. We designed a panfungal polymerase chain reaction (PCR), which targets the highly variable ITS2 region of rDNA genes and uses high resolution melting analysis (HRM) for subsequent species identification. The sensitivity and specificity of this method was tested on a broad spectrum of the most clinically important fungal pathogens including Aspergillus spp., Candida spp. and mucormycetes. Despite the fact that fluid from bronchoalveolar lavage (BAL) is one of the most frequently tested materials there is a lack of literature sources aimed at panfungal PCR as an IFD diagnostic tool from BAL samples. The applicability of this method in routine practice was evaluated on 104 BAL samples from immunocompromised patients. Due to high ITS region variability, we obtained divergent melting peaks for different fungal species. Thirteen out of 18 patients with proven or probable IFD were positive. Therefore, the sensitivity, specificity, positive predictive value and negative predictive value of our method were 67%, 100%, 100%, and 94%, respectively. In our assay, fungal pathogens identification is based on HRM, therefore omitting the expensive and time consuming sequencing step. With the high specificity, positive and negative predictive values, short time needed to obtain a result, and low price, the presented assay is intended to be used as a quick screening method for patients at risk of IFD. PMID:27161789

  9. Gene discovery for the bark beetle-vectored fungal tree pathogen Grosmannia clavigera

    Directory of Open Access Journals (Sweden)

    Robertson Gordon

    2010-10-01

    Full Text Available Abstract Background Grosmannia clavigera is a bark beetle-vectored fungal pathogen of pines that causes wood discoloration and may kill trees by disrupting nutrient and water transport. Trees respond to attacks from beetles and associated fungi by releasing terpenoid and phenolic defense compounds. It is unclear which genes are important for G. clavigera's ability to overcome antifungal pine terpenoids and phenolics. Results We constructed seven cDNA libraries from eight G. clavigera isolates grown under various culture conditions, and Sanger sequenced the 5' and 3' ends of 25,000 cDNA clones, resulting in 44,288 high quality ESTs. The assembled dataset of unique transcripts (unigenes consists of 6,265 contigs and 2,459 singletons that mapped to 6,467 locations on the G. clavigera reference genome, representing ~70% of the predicted G. clavigera genes. Although only 54% of the unigenes matched characterized proteins at the NCBI database, this dataset extensively covers major metabolic pathways, cellular processes, and genes necessary for response to environmental stimuli and genetic information processing. Furthermore, we identified genes expressed in spores prior to germination, and genes involved in response to treatment with lodgepole pine phloem extract (LPPE. Conclusions We provide a comprehensively annotated EST dataset for G. clavigera that represents a rich resource for gene characterization in this and other ophiostomatoid fungi. Genes expressed in response to LPPE treatment are indicative of fungal oxidative stress response. We identified two clusters of potentially functionally related genes responsive to LPPE treatment. Furthermore, we report a simple method for identifying contig misassemblies in de novo assembled EST collections caused by gene overlap on the genome.

  10. Transcriptional control of fungal cell cycle and cellular events by Fkh2, a forkhead transcription factor in an insect pathogen

    OpenAIRE

    Wang, Juan-juan; Qiu, Lei; Cai, Qing; Ying, Sheng-Hua; Feng, Ming-Guang

    2015-01-01

    Transcriptional control of the cell cycle by forkhead (Fkh) transcription factors is likely associated with fungal adaptation to host and environment. Here we show that Fkh2, an ortholog of yeast Fkh1/2, orchestrates cell cycle and many cellular events of Beauveria bassiana, a filamentous fungal insect pathogen. Deletion of Fkh2 in B. bassiana resulted in dramatic down-regulation of the cyclin-B gene cluster and hence altered cell cycle (longer G2/M and S, but shorter G0/G1, phases) in unicel...

  11. Fungal pathogens intercepted in imported germplasm of medicinal and aromatic plants and their quarantine significance

    Directory of Open Access Journals (Sweden)

    Usha Dev

    2011-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} (Abstract selected from presentation in National Conference on Biodiversity of Medicinal and Aromatic Plants: Collection, Characterization and Utilization, held at Anand, India during November 24-25, 2010   International exchange of planting material of medicinal plants germplasm has a significant role in crop improvement programmes as it provides a wide genetic diversity available world wide. However, exchange of the planting material carries an inherent risk of introducing new exotic pathogens/ more virulent races into new areas. Plant quarantine is a government endeavour enforced through legislative measures to regulate the introduction of seeds and planting materials, in order to prevent inadvertent introduction of pests, pathogens and weeds harmful to the agriculture of a country/state/region and if introduced, prevent their establishment and further spread.   During 1976-2009 more than 15,000 samples of more than 70 medicinal and aromatic plants were imported from 42 countries and 330 samples were found to be infected with 29 fungal pathogens. The major interceptions of quarantine significance included Dendryphion penicillatum (Corda Fr., the blight pathogen of opium poppy, a destructive seed

  12. The Mystery of Spot Blotch Disease Caused by the Fungal Pathogen Bipolaris sorokiniana on Barley (Hordeum vulgare L)

    DEFF Research Database (Denmark)

    Gjendal, Nele

    The fungal pathogen Bipolaris sorokiniana causes a wide spectrum of diseases including spot blotch disease. To achieve a better understanding of the biology of the fungus, the interaction of B. sorokiniana with the host barley (Hordeum vulgare L) and the resulting disease spot blotch...... was investigated. In this PhD work it could be shown that light dependent disease symptoms were associated with less fungal colonization, while suppressing the rate of photosynthesis by keeping plants in darkness made them super-susceptible to B. sorokiniana colonization. Likewise, partial suppression...... of photosynthesis with DCMU (3-(3,4-Dichlorophenyl)-1,1-dimethylurea) reduced the formation of necrosis after infection and led to increased susceptibility, strongly implying that active photosynthesis is involved in disease symptom formation and that these symptoms negatively affect fungal colonization...

  13. The Dynamic Genome and Transcriptome of the Human Fungal Pathogen Blastomyces and Close Relative Emmonsia.

    Directory of Open Access Journals (Sweden)

    José F Muñoz

    2015-10-01

    Full Text Available Three closely related thermally dimorphic pathogens are causal agents of major fungal diseases affecting humans in the Americas: blastomycosis, histoplasmosis and paracoccidioidomycosis. Here we report the genome sequence and analysis of four strains of the etiological agent of blastomycosis, Blastomyces, and two species of the related genus Emmonsia, typically pathogens of small mammals. Compared to related species, Blastomyces genomes are highly expanded, with long, often sharply demarcated tracts of low GC-content sequence. These GC-poor isochore-like regions are enriched for gypsy elements, are variable in total size between isolates, and are least expanded in the avirulent B. dermatitidis strain ER-3 as compared with the virulent B. gilchristii strain SLH14081. The lack of similar regions in related species suggests these isochore-like regions originated recently in the ancestor of the Blastomyces lineage. While gene content is highly conserved between Blastomyces and related fungi, we identified changes in copy number of genes potentially involved in host interaction, including proteases and characterized antigens. In addition, we studied gene expression changes of B. dermatitidis during the interaction of the infectious yeast form with macrophages and in a mouse model. Both experiments highlight a strong antioxidant defense response in Blastomyces, and upregulation of dioxygenases in vivo suggests that dioxide produced by antioxidants may be further utilized for amino acid metabolism. We identify a number of functional categories upregulated exclusively in vivo, such as secreted proteins, zinc acquisition proteins, and cysteine and tryptophan metabolism, which may include critical virulence factors missed before in in vitro studies. Across the dimorphic fungi, loss of certain zinc acquisition genes and differences in amino acid metabolism suggest unique adaptations of Blastomyces to its host environment. These results reveal the dynamics

  14. Effects of volatile organic compounds from Streptomyces albulus NJZJSA2 on growth of two fungal pathogens.

    Science.gov (United States)

    Wu, Yuncheng; Yuan, Jun; E, Yaoyao; Raza, Waseem; Shen, Qirong; Huang, Qiwei

    2015-09-01

    A Streptomyces albulus strain NJZJSA2 was isolated from the forest soil sample of Tzu-chin Mountain (Nanjing China) and identified based on its morphological and physiological properties and 16S rDNA gene sequence analysis. The strain S. albulus NJZJSA2 was evaluated for the production of antifungal volatile organic compounds (VOCs) against two fungal pathogens. Results showed that the VOCs generated by S. albulus NJZJSA2 inhibited mycelial growth of Sclerotinia sclerotiorum (SS) and Fusarium oxysporum (FO) by 100 and 56.3%, respectively. The germination of SS sclerotia and FO conidia was completely inhibited in the presence of VOCs produced by S. albulus NJZJSA2 in vitro. In soil, the VOCs delayed the germination of SS sclerotia and inhibited the germination of FO conidia for 45 days. The strain S. albulus NJZJSA2 was able to produce 13 VOCs based on GC/MS analyses. Among those, six compounds were purchased and used for the antifungal activity assay. Three relatively abundant VOCs, 4-methoxystyrene, 2-pentylfuran, and anisole were proved to have antifungal activity. Microscopy analysis showed that the pathogen hyphae were shriveled and damaged after treatment with 4-methoxystyrene. These results suggest that the S. albulus strain NJZJSA2 produce VOCs that not only reduce the growth of SS and FO, but also significantly inhibit the SS sclerotia and FO conidia. The results are useful for the better understanding of biocontrol mechanisms by S. albulus strains and will help to improve the biological control efficiency of lethal plant diseases. PMID:26059065

  15. The wheat Lr34 gene provides resistance against multiple fungal pathogens in barley.

    Science.gov (United States)

    Risk, Joanna M; Selter, Liselotte L; Chauhan, Harsh; Krattinger, Simon G; Kumlehn, Jochen; Hensel, Goetz; Viccars, Libby A; Richardson, Terese M; Buesing, Gabriele; Troller, Anna; Lagudah, Evans S; Keller, Beat

    2013-09-01

    The Lr34 gene encodes an ABC transporter and has provided wheat with durable, broad-spectrum resistance against multiple fungal pathogens for over 100 years. Because barley does not have an Lr34 ortholog, we expressed Lr34 in barley to investigate its potential as a broad-spectrum resistance resource in another grass species. We found that introduction of the genomic Lr34 sequence confers resistance against barley leaf rust and barley powdery mildew, two pathogens specific for barley but not virulent on wheat. In addition, the barley lines showed enhanced resistance against wheat stem rust. Transformation with the Lr34 cDNA or the genomic susceptible Lr34 allele did not result in increased resistance. Unlike wheat, where Lr34-conferred resistance is associated with adult plants, the genomic Lr34 transgenic barley lines exhibited multipathogen resistance in seedlings. These transgenic barley lines also developed leaf tip necrosis (LTN) in young seedlings, which correlated with an up-regulation of senescence marker genes and several pathogenesis-related (PR) genes. In wheat, transcriptional expression of Lr34 is highest in adult plants and correlates with increased resistance and LTN affecting the last emerging leaf. The severe phenotype of transgenic Lr34 barley resulted in reduced plant growth and total grain weight. These results demonstrate that Lr34 provides enhanced multipathogen resistance early in barley plant development and implies the conservation of the substrate and mechanism of the LR34 transporter and its molecular action between wheat and barley. With controlled gene expression, the use of Lr34 may be valuable for many cereal breeding programmes, particularly given its proven durability.

  16. Ancient dispersal of the human fungal pathogen Cryptococcus gattii from the Amazon rainforest.

    Directory of Open Access Journals (Sweden)

    Ferry Hagen

    Full Text Available Over the past two decades, several fungal outbreaks have occurred, including the high-profile 'Vancouver Island' and 'Pacific Northwest' outbreaks, caused by Cryptococcus gattii, which has affected hundreds of otherwise healthy humans and animals. Over the same time period, C. gattii was the cause of several additional case clusters at localities outside of the tropical and subtropical climate zones where the species normally occurs. In every case, the causative agent belongs to a previously rare genotype of C. gattii called AFLP6/VGII, but the origin of the outbreak clades remains enigmatic. Here we used phylogenetic and recombination analyses, based on AFLP and multiple MLST datasets, and coalescence gene genealogy to demonstrate that these outbreaks have arisen from a highly-recombining C. gattii population in the native rainforest of Northern Brazil. Thus the modern virulent C. gattii AFLP6/VGII outbreak lineages derived from mating events in South America and then dispersed to temperate regions where they cause serious infections in humans and animals.

  17. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens

    Science.gov (United States)

    Reem, Nathan T.; Pogorelko, Gennady; Lionetti, Vincenzo; Chambers, Lauran; Held, Michael A.; Bellincampi, Daniela; Zabotina, Olga A.

    2016-01-01

    The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity (CWI) and function remains unclear. Modifications of cell wall composition can induce plant responses known as CWI control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, decreased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant CWI, which contributes to plant resistance to necrotrophic pathogens. PMID:27242834

  18. Biological Control of Spreading Dayflower (Commelina diffusa with the Fungal Pathogen Phoma commelinicola

    Directory of Open Access Journals (Sweden)

    Clyde D. Boyette

    2015-10-01

    Full Text Available Greenhouse and field experiments showed that conidia of the fungal pathogen, Phoma commelinicola, exhibited bioherbicidal activity against spreading dayflower (Commelina diffusa seedlings when applied at concentrations of 106 to 109 conidia·mL−1. Greenhouse tests determined an optimal temperature for conidial germination of 25 °C–30 °C, and that sporulation occurred on several solid growth media. A dew period of ≥ 12 h was required to achieve 60% control of cotyledonary-first leaf growth stage seedlings when applications of 108 conidia·mL−1 were applied. Maximal control (80% required longer dew periods (21 h and 90% plant dry weight reduction occurred at this dew period duration. More efficacious control occurred on younger plants (cotyledonary-first leaf growth stage than older, larger plants. Mortality and dry weight reduction values in field experiments were ~70% and >80%, respectively, when cotyledonary-third leaf growth stage seedlings were sprayed with 108 or 109 conidia·mL−1. These results indicate that this fungus has potential as a biological control agent for controlling this problematic weed that is tolerant to the herbicide glyphosate.

  19. Force nanoscopy of hydrophobic interactions in the fungal pathogen Candida glabrata.

    Science.gov (United States)

    El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Derclaye, Sylvie; Alsteens, David; Kucharíková, Soňa; Van Dijck, Patrick; Dufrêne, Yves F

    2015-02-24

    Candida glabrata is an opportunistic human fungal pathogen which binds to surfaces mainly through the Epa family of cell adhesion proteins. While some Epa proteins mediate specific lectin-like interactions with human epithelial cells, others promote adhesion and biofilm formation on plastic surfaces via nonspecific interactions that are not yet elucidated. We report the measurement of hydrophobic forces engaged in Epa6-mediated cell adhesion by means of atomic force microscopy (AFM). Using single-cell force spectroscopy, we found that C. glabrata wild-type (WT) cells attach to hydrophobic surfaces via strongly adhesive macromolecular bonds, while mutant cells impaired in Epa6 expression are weakly adhesive. Nanoscale mapping of yeast cells using AFM tips functionalized with hydrophobic groups shows that Epa6 is massively exposed on WT cells and conveys strong hydrophobic properties to the cell surface. Our results demonstrate that Epa6 mediates strong hydrophobic interactions, thereby providing a molecular basis for the ability of this adhesin to drive biofilm formation on abiotic surfaces.

  20. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens.

    Science.gov (United States)

    Reem, Nathan T; Pogorelko, Gennady; Lionetti, Vincenzo; Chambers, Lauran; Held, Michael A; Bellincampi, Daniela; Zabotina, Olga A

    2016-01-01

    The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity (CWI) and function remains unclear. Modifications of cell wall composition can induce plant responses known as CWI control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, decreased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant CWI, which contributes to plant resistance to necrotrophic pathogens.

  1. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    Nathan T Reem

    2016-05-01

    Full Text Available The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity and function remains unclear. Modifications of cell wall composition can induce plant responses known as Cell Wall Integrity control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, increased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant cell wall integrity, which contributes to plant resistance to necrotrophic pathogens.

  2. Determination of cellular carbohydrates in peanut fungal pathogens and baker's yeast by capillary electrophoresis and electrochromatography.

    Science.gov (United States)

    Zhang, M; Melouk, H A; Chenault, K; El Rassi, Z

    2001-11-01

    In this work, the quantitation of cellular carbohydrates, namely chitin and glucan, in peanut fungal pathogens and baker's yeast was carried out by capillary electrophoresis (CE) and capillary electrochromatography (CEC). The chitin and glucan of the fungi were hydrolyzed by the enzymes chitinase and glucanase, respectively, to their corresponding sugar monomers N-acetylglucosamine (GlcNAc) and glucose (Glc). These two monosaccharides were then tagged with 6-aminoquinoline (6-AQ) to allow their separation and detection in CE and CEC. The 6-AQ derivatives of GlcNAc and Glc formed the basis for the determination by CE and CEC of chitin and glucan in peanut fungi and baker's yeast. Several parameters affecting the separation of the 6-AQ derivatives of GlcNAc and Glc, including the separation voltage and the composition of the running electrolyte, were investigated. Under the optimized separation conditions, the contents of cellular carbohydrates including N-acetylglucosamine, chitin, glucose, and glucan in some fungi, such as Sclerotinia minor, Sclerotium rolfsii, and baker's yeast, were successfully determined. The method described here allowed the assessment of genetic differences in Sclerotium rolfsii isolates from various locations. PMID:11714314

  3. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens.

    Science.gov (United States)

    Reem, Nathan T; Pogorelko, Gennady; Lionetti, Vincenzo; Chambers, Lauran; Held, Michael A; Bellincampi, Daniela; Zabotina, Olga A

    2016-01-01

    The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity (CWI) and function remains unclear. Modifications of cell wall composition can induce plant responses known as CWI control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, decreased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant CWI, which contributes to plant resistance to necrotrophic pathogens. PMID:27242834

  4. Chlorine-rich plasma polymer coating for the prevention of attachment of pathogenic fungal cells onto materials surfaces

    Science.gov (United States)

    Lamont-Friedrich, Stephanie J.; Michl, Thomas D.; Giles, Carla; Griesser, Hans J.; Coad, Bryan R.

    2016-07-01

    The attachment of pathogenic fungal cells onto materials surfaces, which is often followed by biofilm formation, causes adverse consequences in a wide range of areas. Here we have investigated the ability of thin film coatings from chlorinated molecules to deter fungal colonization of solid materials by contact killing of fungal cells reaching the surface of the coating. Coatings were deposited onto various substrate materials via plasma polymerization, which is a substrate-independent process widely used for industrial coating applications, using 1,1,2-trichloroethane as the process vapour. XPS surface analysis showed that the coatings were characterized by a highly chlorinated hydrocarbon polymer nature, with only a very small amount of oxygen incorporated. The activity of these coatings against human fungal pathogens was quantified using a recently developed, modified yeast assay and excellent antifungal activity was observed against Candida albicans and Candida glabrata. Plasma polymer surface coatings derived from chlorinated hydrocarbon molecules may therefore offer a promising solution to preventing yeast and mould biofilm formation on materials surfaces, for applications such as air conditioners, biomedical devices, food processing equipment, and others.

  5. Simultaneous transcriptome analysis of Colletotrichum gloeosporioides and tomato fruit pathosystem reveals novel fungal pathogenicity and fruit defense strategies.

    Science.gov (United States)

    Alkan, Noam; Friedlander, Gilgi; Ment, Dana; Prusky, Dov; Fluhr, Robert

    2015-01-01

    The fungus Colletotrichum gloeosporioides breaches the fruit cuticle but remains quiescent until fruit ripening signals a switch to necrotrophy, culminating in devastating anthracnose disease. There is a need to understand the distinct fungal arms strategy and the simultaneous fruit response. Transcriptome analysis of fungal-fruit interactions was carried out concurrently in the appressoria, quiescent and necrotrophic stages. Conidia germinating on unripe fruit cuticle showed stage-specific transcription that was accompanied by massive fruit defense responses. The subsequent quiescent stage showed the development of dendritic-like structures and swollen hyphae within the fruit epidermis. The quiescent fungal transcriptome was characterized by activation of chromatin remodeling genes and unsuspected environmental alkalization. Fruit response was portrayed by continued highly integrated massive up-regulation of defense genes. During cuticle infection of green or ripe fruit, fungi recapitulate the same developmental stages but with differing quiescent time spans. The necrotrophic stage showed a dramatic shift in fungal metabolism and up-regulation of pathogenicity factors. Fruit response to necrotrophy showed activation of the salicylic acid pathway, climaxing in cell death. Transcriptome analysis of C. gloeosporioides infection of fruit reveals its distinct stage-specific lifestyle and the concurrent changing fruit response, deepening our perception of the unfolding fungal-fruit arms and defenses race.

  6. Volatiles Emitted from Maize Ears Simultaneously Infected with Two Fusarium Species Mirror the Most Competitive Fungal Pathogen

    Science.gov (United States)

    Sherif, Mohammed; Becker, Eva-Maria; Herrfurth, Cornelia; Feussner, Ivo; Karlovsky, Petr; Splivallo, Richard

    2016-01-01

    Along with barley and rice, maize provides staple food for more than half of the world population. Maize ears are regularly infected with fungal pathogens of the Fusarium genus, which, besides reducing yield, also taint grains with toxic metabolites. In an earlier work, we have shown that maize ears infection with single Fusarium strains was detectable through volatile sensing. In nature, infection most commonly occurs with more than a single fungal strain; hence we tested how the interactions of two strains would modulate volatile emission from infected ears. For this purpose, ears of a hybrid and a dwarf maize variety were simultaneously infected with different strains of Fusarium graminearum and F. verticillioides and, the resulting volatile profiles were compared to the ones of ears infected with single strains. Disease severity, fungal biomass, and the concentration of the oxylipin 9-hydroxy octadecadienoic acid, a signaling molecule involved in plant defense, were monitored and correlated to volatile profiles. Our results demonstrate that in simultaneous infections of hybrid and dwarf maize, the most competitive fungal strains had the largest influence on the volatile profile of infected ears. In both concurrent and single inoculations, volatile profiles reflected disease severity. Additionally, the data further indicate that dwarf maize and hybrid maize might emit common (i.e., sesquiterpenoids) and specific markers upon fungal infection. Overall this suggests that volatile profiles might be a good proxy for disease severity regardless of the fungal competition taking place in maize ears. With the appropriate sensitivity and reliability, volatile sensing thus appears as a promising tool for detecting fungal infection of maize ears under field conditions. PMID:27729923

  7. An essential role for the NLRP3 inflammasome in host defense against the human fungal pathogen, Candida albicans

    OpenAIRE

    Hise, Amy G.; Tomalka, Jeffrey; Ganesan, Sandhya; Patel, Krupen; Hall, Brian A.; Brown, Gordon D.; Fitzgerald, Katherine A.

    2009-01-01

    Candida albicans is an opportunistic fungal pathogen causing life-threatening mucosal and systemic infections in immunocompromised humans. Using a murine model of mucosal Candida infection we investigated the role of the proinflammatory cytokine IL-1β in host-defense to Candida albicans. We find that the synthesis, processing and release of IL-1β in response to Candida are tightly controlled and first require transcriptional induction, followed by a second signal leading to caspase-1 mediated...

  8. Detection of DOPA-Melanin in the Dimorphic Fungal Pathogen Penicillium marneffei and Its Effect on Macrophage Phagocytosis In Vitro

    OpenAIRE

    Donghua Liu; Lili Wei; Ting Guo; Weifen Tan

    2014-01-01

    The fungal pathogen Penicillium marneffei produces melanin-like pigment in vitro. The synthetic pathway of melanin and its possible influence in the protective yeast cells surviving within macrophage cells are not known. In this work, P. marneffei produced brown black pigment in the presence of L-DOPA and black particles were extracted from yeast cells treated with proteolytic enzymes, denaturant and concentrated hot acid. Kojic acid inhibited the brown-black pigment production of P. marneffe...

  9. Detection of Melanin-Like Pigments in the Dimorphic Fungal Pathogen Paracoccidioides brasiliensis In Vitro and during Infection

    OpenAIRE

    Gómez, Beatriz L.; Nosanchuk, Joshua D.; Díez, Soraya; Youngchim, Sirida; Aisen, Philip; Cano, Luz E.; Restrepo, Angela; Casadevall, Arturo; Hamilton, Andrew J.

    2001-01-01

    Melanins are implicated in the pathogenesis of several human diseases, including some microbial infections. In this study, we analyzed whether the conidia and the yeasts of the thermally dimorphic fungal pathogen Paracoccidioides brasiliensis produce melanin or melanin-like compounds in vitro and during infection. Growth of P. brasiliensis mycelia on water agar alone produced pigmented conidia, and growth of yeasts in minimal medium with l-3,4-dihydroxyphenylalanine (l-DOPA) produced pigmente...

  10. Transposons passively and actively contribute to evolution of the two-speed genome of a fungal pathogen

    Science.gov (United States)

    Faino, Luigi; Seidl, Michael F.; Shi-Kunne, Xiaoqian; Pauper, Marc; van den Berg, Grardy C.M.; Wittenberg, Alexander H.J.

    2016-01-01

    Genomic plasticity enables adaptation to changing environments, which is especially relevant for pathogens that engage in “arms races” with their hosts. In many pathogens, genes mediating virulence cluster in highly variable, transposon-rich, physically distinct genomic compartments. However, understanding of the evolution of these compartments, and the role of transposons therein, remains limited. Here, we show that transposons are the major driving force for adaptive genome evolution in the fungal plant pathogen Verticillium dahliae. We show that highly variable lineage-specific (LS) regions evolved by genomic rearrangements that are mediated by erroneous double-strand repair, often utilizing transposons. We furthermore show that recent genetic duplications are enhanced in LS regions, against an older episode of duplication events. Finally, LS regions are enriched in active transposons, which contribute to local genome plasticity. Thus, we provide evidence for genome shaping by transposons, both in an active and passive manner, which impacts the evolution of pathogen virulence. PMID:27325116

  11. Aleppo pine defense against Sphaeropsis sapinea, Cronartium flaccidum and other fungal pathogens in the Mediterranean part of Montenegro

    Directory of Open Access Journals (Sweden)

    Karadžić Dragan

    2009-01-01

    Full Text Available Aleppo pine (Pinus halepensis Mill. is the most widely disturbed conifer tree in native forest and plantations throughout the Adriatic coast of Montenegro. However, pathogenic fungi in the region are extremely diversified and constitute the principal threat to healthy tree growth: 15 pathogenic fungal species have beden identified in the Eumediterranean zone - a typical habitat of Aleppo pine, whereas 21 fungal pathogens occurred in northern Submediterranean zone - an atypical habitat for Aleppo pine in Montenegro. Greatest damages are inflicted by Sphaeropsis sapinea, a pathogenic generalist on pine, and Cronartium flaccidum, causal agent of rust disease on pine. The following relates, for the first time, the presence of hypersensitive response (HR in young needles and shoots (organs rich in nitrogen as a specific defense mechanism in Aleppo pine against Sphaeropsis sapinea, an otherwise very harmful pathogen for Austrian pine (Pinus nigra Arn. and other pines in the Mediterranean part of Montenegro. Thus, better understanding of the ecology of S. sapinea, of C. flaccidum, as well as of associated mycobiota and mechanisms of host defense are essential for establishing measures and tools for protection of Aleppo pine ecosystems.

  12. The endosymbiont Arsenophonus is widespread in soybean aphid, Aphis glycines, but does not provide protection from parasitoids or a fungal pathogen

    Science.gov (United States)

    Aphids commonly harbor bacterial facultative symbionts that have a variety of effects upon their aphid hosts, including defense against hymenopteran parasitoids and fungal pathogens. The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is infected with the symbiont, Arsenophonus sp., ...

  13. The Role of Mitogen-Activated Protein (MAP Kinase Signaling Components in the Fungal Development, Stress Response and Virulence of the Fungal Cereal Pathogen Bipolaris sorokiniana.

    Directory of Open Access Journals (Sweden)

    Yueqiang Leng

    Full Text Available Mitogen-activated protein kinases (MAPKs have been demonstrated to be involved in fungal development, sexual reproduction, pathogenicity and/or virulence in many filamentous plant pathogenic fungi, but genes for MAPKs in the fungal cereal pathogen Bipolaris sorokiniana have not been characterized. In this study, orthologues of three MAPK genes (CsSLT2, CsHOG1 and CsFUS3 and one MAPK kinase kinase (MAPKKK gene (CsSTE11 were identified in the whole genome sequence of the B. sorokiniana isolate ND90Pr, and knockout mutants were generated for each of them. The ∆Csfus3 and ∆Csste11 mutants were defective in conidiation and formation of appressoria-like structures, showed hypersensitivity to oxidative stress and lost pathogenicity on non-wounded leaves of barley cv. Bowman. When inoculated on wounded leaves of Bowman, the ∆Csfus3 and ∆Csste11 mutants were reduced in virulence compared to the wild type. No morphological changes were observed in the ∆Cshog1 mutants in comparison with the wild type; however, they were slightly reduced in growth under oxidative stress and were hypersensitive to hyperosmotic stress. The ∆Cshog1 mutants formed normal appressoria-like structures but were reduced in virulence when inoculated on Bowman leaves. The ∆Csslt2 mutants produced more vegetative hyphae, had lighter pigmentation, were more sensitive to cell wall degrading enzymes, and were reduced in virulence on Bowman leaves, although they formed normal appressoria like the wild type. Root infection assays indicated that the ∆Cshog1 and ∆Csslt2 mutants were able to infect barley roots while the ∆Csfus3 and ∆Csste11 failed to cause any symptoms. However, no significant difference in virulence was observed for ∆Cshog1 mutants while ∆Csslt2 mutants showed significantly reduced virulence on barley roots in comparison with the wild type. Our results indicated that all of these MAPK and MAPKKK genes are involved in the regulation of fungal

  14. The Role of Mitogen-Activated Protein (MAP) Kinase Signaling Components in the Fungal Development, Stress Response and Virulence of the Fungal Cereal Pathogen Bipolaris sorokiniana.

    Science.gov (United States)

    Leng, Yueqiang; Zhong, Shaobin

    2015-01-01

    Mitogen-activated protein kinases (MAPKs) have been demonstrated to be involved in fungal development, sexual reproduction, pathogenicity and/or virulence in many filamentous plant pathogenic fungi, but genes for MAPKs in the fungal cereal pathogen Bipolaris sorokiniana have not been characterized. In this study, orthologues of three MAPK genes (CsSLT2, CsHOG1 and CsFUS3) and one MAPK kinase kinase (MAPKKK) gene (CsSTE11) were identified in the whole genome sequence of the B. sorokiniana isolate ND90Pr, and knockout mutants were generated for each of them. The ∆Csfus3 and ∆Csste11 mutants were defective in conidiation and formation of appressoria-like structures, showed hypersensitivity to oxidative stress and lost pathogenicity on non-wounded leaves of barley cv. Bowman. When inoculated on wounded leaves of Bowman, the ∆Csfus3 and ∆Csste11 mutants were reduced in virulence compared to the wild type. No morphological changes were observed in the ∆Cshog1 mutants in comparison with the wild type; however, they were slightly reduced in growth under oxidative stress and were hypersensitive to hyperosmotic stress. The ∆Cshog1 mutants formed normal appressoria-like structures but were reduced in virulence when inoculated on Bowman leaves. The ∆Csslt2 mutants produced more vegetative hyphae, had lighter pigmentation, were more sensitive to cell wall degrading enzymes, and were reduced in virulence on Bowman leaves, although they formed normal appressoria like the wild type. Root infection assays indicated that the ∆Cshog1 and ∆Csslt2 mutants were able to infect barley roots while the ∆Csfus3 and ∆Csste11 failed to cause any symptoms. However, no significant difference in virulence was observed for ∆Cshog1 mutants while ∆Csslt2 mutants showed significantly reduced virulence on barley roots in comparison with the wild type. Our results indicated that all of these MAPK and MAPKKK genes are involved in the regulation of fungal development under

  15. Monitoring of antimicrobial resistance in pathogenic bacteria from livestock animals.

    Science.gov (United States)

    Wallmann, Jürgen

    2006-06-01

    Facing the problem of development and spreading of bacterial resistance, preventive strategies are considered the most appropriate means to counteract. The establishment of corresponding management options relies on scientifically defensible efforts to obtain objective data on the prevalence of bacterial resistance in healthy and diseased livestock. Additionally, detailed statistics are needed on the overall amount of antimicrobial agents dispensed in Germany. The collection of valid data on the prevalence of resistance requires representative and cross-sectional studies. The German national antimicrobial resistance monitoring of the Federal Office of Consumer Protection and Food Safety (BVL) determines the current quantitative resistance level of life-stock pathogens, in order to permit the evaluation and surveillance of the distribution of resistances on a valid basis. Essential key features determining the design of these studies comprise (1) a statistically valid sampling program. This incorporates regional differences in animal population density, (2) the avoidance of "copy strains", (3) testing of no more than two bacterial strains belonging to one species per herd, (4) testing only if no antimicrobial therapy preceded sample collection, and (5) the use of standardized methods [e.g. microdilution broth method to determine the minimal inhibitory concentration (MIC)]. The analysis and interpretation of this data permits reliable identification and definition of epidemiological characteristics of resistance and its development in animal associated bacteria, such as geographically and time wise differentiated profiles on its prevalence, the emergence of unknown phenotypes of resistance and an assessment of the threat resistant bacteria from animals pose for humans. In applied antimicrobial therapy, the data can serve as a decision guidance in choosing the antimicrobial agent most adapted to the prevailing epidemiological situation. The susceptibility testing

  16. Population Genetic Analyses of the Fungal Pathogen Colletotrichum fructicola on Tea-Oil Trees in China.

    Science.gov (United States)

    Li, He; Zhou, Guo-Ying; Liu, Jun-Ang; Xu, Jianping

    2016-01-01

    The filamentous fungus Colletotrichum fructicola is found in all five continents and is capable of causing severe diseases in a number of economically important plants such as avocado, fig, cocoa, pear, and tea-oil trees. However, almost nothing is known about its patterns of genetic variation and epidemiology on any of its host plant species. Here we analyzed 167 isolates of C. fructicola obtained from the leaves of tea-oil tree Camellia oleifera at 15 plantations in seven Chinese provinces. Multilocus sequence typing was conducted for all isolates based on DNA sequences at fragments of four genes: the internal transcribed spacers of the nuclear ribosomal RNA gene cluster (539 bp), calmodulin (633 bp), glutamine synthetase (711 bp), and glyceraldehyde-3-phosphate dehydrogenase (190 bp), yielding 3.52%, 0.63%, 8.44%, and 7.89% of single nucleotide polymorphic sites and resulting in 15, 5, 12 and 11 alleles respectively at the four gene fragments in the total sample. The combined allelic information from all four loci identified 53 multilocus genotypes with the most frequent represented by 21 isolates distributed in eight tea-oil plantations in three provinces, consistent with long-distance clonal dispersal. However, despite evidence for clonal dispersal, statistically significant genetic differentiation among geographic populations was detected. In addition, while no evidence of recombination was found within any of the four gene fragments, signatures of recombination were found among the four gene fragments in most geographic populations, consistent with sexual mating of this species in nature. Our study provides the first insights into the population genetics and epidemiology of the important plant fungal pathogen C. fructicola. PMID:27299731

  17. Population Genetic Analyses of the Fungal Pathogen Colletotrichum fructicola on Tea-Oil Trees in China

    Science.gov (United States)

    Li, He; Zhou, Guo-Ying; Liu, Jun-Ang; Xu, Jianping

    2016-01-01

    The filamentous fungus Colletotrichum fructicola is found in all five continents and is capable of causing severe diseases in a number of economically important plants such as avocado, fig, cocoa, pear, and tea-oil trees. However, almost nothing is known about its patterns of genetic variation and epidemiology on any of its host plant species. Here we analyzed 167 isolates of C. fructicola obtained from the leaves of tea-oil tree Camellia oleifera at 15 plantations in seven Chinese provinces. Multilocus sequence typing was conducted for all isolates based on DNA sequences at fragments of four genes: the internal transcribed spacers of the nuclear ribosomal RNA gene cluster (539 bp), calmodulin (633 bp), glutamine synthetase (711 bp), and glyceraldehyde-3-phosphate dehydrogenase (190 bp), yielding 3.52%, 0.63%, 8.44%, and 7.89% of single nucleotide polymorphic sites and resulting in 15, 5, 12 and 11 alleles respectively at the four gene fragments in the total sample. The combined allelic information from all four loci identified 53 multilocus genotypes with the most frequent represented by 21 isolates distributed in eight tea-oil plantations in three provinces, consistent with long-distance clonal dispersal. However, despite evidence for clonal dispersal, statistically significant genetic differentiation among geographic populations was detected. In addition, while no evidence of recombination was found within any of the four gene fragments, signatures of recombination were found among the four gene fragments in most geographic populations, consistent with sexual mating of this species in nature. Our study provides the first insights into the population genetics and epidemiology of the important plant fungal pathogen C. fructicola. PMID:27299731

  18. Population Genetic Analyses of the Fungal Pathogen Colletotrichum fructicola on Tea-Oil Trees in China.

    Directory of Open Access Journals (Sweden)

    He Li

    Full Text Available The filamentous fungus Colletotrichum fructicola is found in all five continents and is capable of causing severe diseases in a number of economically important plants such as avocado, fig, cocoa, pear, and tea-oil trees. However, almost nothing is known about its patterns of genetic variation and epidemiology on any of its host plant species. Here we analyzed 167 isolates of C. fructicola obtained from the leaves of tea-oil tree Camellia oleifera at 15 plantations in seven Chinese provinces. Multilocus sequence typing was conducted for all isolates based on DNA sequences at fragments of four genes: the internal transcribed spacers of the nuclear ribosomal RNA gene cluster (539 bp, calmodulin (633 bp, glutamine synthetase (711 bp, and glyceraldehyde-3-phosphate dehydrogenase (190 bp, yielding 3.52%, 0.63%, 8.44%, and 7.89% of single nucleotide polymorphic sites and resulting in 15, 5, 12 and 11 alleles respectively at the four gene fragments in the total sample. The combined allelic information from all four loci identified 53 multilocus genotypes with the most frequent represented by 21 isolates distributed in eight tea-oil plantations in three provinces, consistent with long-distance clonal dispersal. However, despite evidence for clonal dispersal, statistically significant genetic differentiation among geographic populations was detected. In addition, while no evidence of recombination was found within any of the four gene fragments, signatures of recombination were found among the four gene fragments in most geographic populations, consistent with sexual mating of this species in nature. Our study provides the first insights into the population genetics and epidemiology of the important plant fungal pathogen C. fructicola.

  19. Robust calling performance in frogs infected by a deadly fungal pathogen.

    Science.gov (United States)

    Greenspan, Sasha E; Roznik, Elizabeth A; Schwarzkopf, Lin; Alford, Ross A; Pike, David A

    2016-08-01

    Reproduction is an energetically costly behavior for many organisms, including species with mating systems in which males call to attract females. In these species, calling males can often attract more females by displaying more often, with higher intensity, or at certain frequencies. Male frogs attract females almost exclusively by calling, and we know little about how pathogens, including the globally devastating fungus, Batrachochytrium dendrobatidis, influence calling effort and call traits. A previous study demonstrated that the nightly probability of calling by male treefrogs, Litoria rheocola, is elevated when they are in good body condition and are infected by B. dendrobatidis. This suggests that infections may cause males to increase their present investment in mate attraction to compensate for potential decreases in future reproduction. However, if infection by B. dendrobatidis decreases the attractiveness of their calls, infected males might experience decreased reproductive success despite increases in calling effort. We examined whether calls emitted by L. rheocola infected by B. dendrobatidis differed from those of uninfected individuals in duration, pulse rate, dominant frequency, call rate, or intercall interval, the attributes commonly linked to mate choice. We found no effects of fungal infection status or infection intensity on any call attribute. Our results indicate that infected males produce calls similar in all the qualities we measured to those of uninfected males. It is therefore likely that the calls of infected and uninfected males should be equally attractive to females. The increased nightly probability of calling previously demonstrated for infected males in good condition may therefore lead to greater reproductive success than that of uninfected males. This could reduce the effectiveness of natural selection for resistance to infection, but could increase the effectiveness of selection for infection tolerance, the ability to

  20. Coincident mass extirpation of neotropical amphibians with the emergence of the infectious fungal pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Cheng, Tina L; Rovito, Sean M; Wake, David B; Vredenburg, Vance T

    2011-06-01

    Amphibians highlight the global biodiversity crisis because ∼40% of all amphibian species are currently in decline. Species have disappeared even in protected habitats (e.g., the enigmatic extinction of the golden toad, Bufo periglenes, from Costa Rica). The emergence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been implicated in a number of declines that have occurred in the last decade, but few studies have been able to test retroactively whether Bd emergence was linked to earlier declines and extinctions. We describe a noninvasive PCR sampling technique that detects Bd in formalin-preserved museum specimens. We detected Bd by PCR in 83-90% (n = 38) of samples that were identified as positive by histology. We examined specimens collected before, during, and after major amphibian decline events at established study sites in southern Mexico, Guatemala, and Costa Rica. A pattern of Bd emergence coincident with decline at these localities is revealed-the absence of Bd over multiple years at all localities followed by the concurrent emergence of Bd in various species at each locality during a period of population decline. The geographical and chronological emergence of Bd at these localities also indicates a southbound spread from southern Mexico in the early 1970s to western Guatemala in the 1980s/1990s and to Monteverde, Costa Rica by 1987. We find evidence of a historical "Bd epidemic wave" that began in Mexico and subsequently spread to Central America. We describe a technique that can be used to screen museum specimens from other amphibian decline sites around the world.

  1. Role of glutathione in the oxidative stress response in the fungal pathogen Candida glabrata.

    Science.gov (United States)

    Gutiérrez-Escobedo, Guadalupe; Orta-Zavalza, Emmanuel; Castaño, Irene; De Las Peñas, Alejandro

    2013-08-01

    Candida glabrata, an opportunistic fungal pathogen, accounts for 18-26 % of all Candida systemic infections in the US. C. glabrata has a robust oxidative stress response (OSR) and in this work we characterized the role of glutathione (GSH), an essential tripeptide-like thiol-containing molecule required to keep the redox homeostasis and in the detoxification of metal ions. GSH is synthesized from glutamate, cysteine, and glycine by the sequential action of Gsh1 (γ-glutamyl-cysteine synthetase) and Gsh2 (glutathione synthetase) enzymes. We first screened for suppressor mutations that would allow growth in the absence of GSH1 (gsh1∆ background) and found a single point mutation in PRO2 (pro2-4), a gene that encodes a γ-glutamyl phosphate reductase and catalyzes the second step in the biosynthesis of proline. We demonstrate that GSH is important in the OSR since the gsh1∆ pro2-4 and gsh2∆ mutant strains are more sensitive to oxidative stress generated by H2O2 and menadione. GSH is also required for Cadmium tolerance. In the absence of Gsh1 and Gsh2, cells show decreased viability in stationary phase. Furthermore, C. glabrata does not contain Saccharomyces cerevisiae high affinity GSH transporter ortholog, ScOpt1/Hgt1, however, our genetic and biochemical experiments show that the gsh1∆ pro2-4 and gsh2∆ mutant strains are able to incorporate GSH from the medium. Finally, GSH and thioredoxin, which is a second redox system in the cell, are not essential for the catalase-independent adaptation response to H2O2. PMID:23455613

  2. Regulatory network modelling of iron acquisition by a fungal pathogen in contact with epithelial cells

    Directory of Open Access Journals (Sweden)

    Guthke Reinhard

    2010-11-01

    Full Text Available Abstract Background Reverse engineering of gene regulatory networks can be used to predict regulatory interactions of an organism faced with environmental changes, but can prove problematic, especially when focusing on complicated multi-factorial processes. Candida albicans is a major human fungal pathogen. During the infection process, this fungus is able to adapt to conditions of very low iron availability. Such adaptation is an important virulence attribute of virtually all pathogenic microbes. Understanding the regulation of iron acquisition genes will extend our knowledge of the complex regulatory changes during the infection process and might identify new potential drug targets. Thus, there is a need for efficient modelling approaches predicting key regulatory events of iron acquisition genes during the infection process. Results This study deals with the regulation of C. albicans iron uptake genes during adhesion to and invasion into human oral epithelial cells. A reverse engineering strategy is presented, which is able to infer regulatory networks on the basis of gene expression data, making use of relevant selection criteria such as sparseness and robustness. An exhaustive use of available knowledge from different data sources improved the network prediction. The predicted regulatory network proposes a number of new target genes for the transcriptional regulators Rim101, Hap3, Sef1 and Tup1. Furthermore, the molecular mode of action for Tup1 is clarified. Finally, regulatory interactions between the transcription factors themselves are proposed. This study presents a model describing how C. albicans may regulate iron acquisition during contact with and invasion of human oral epithelial cells. There is evidence that some of the proposed regulatory interactions might also occur during oral infection. Conclusions This study focuses on a typical problem in Systems Biology where an interesting biological phenomenon is studied using a small

  3. Phage isolated from animal feces effectively reduce foodborne pathogens in the gut of cattle and swine

    Science.gov (United States)

    Food animals can harbour foodborne pathogens (e.g., enterohemorrhagic E. coli and Salmonella spp.) in their gut that can be spread to humans via contaminated meat products or water and crops contaminated with pathogens by farm run-off. If the pathogen load can be reduced on the farm, then the effec...

  4. Comparative genomics of the Staphylococcus intermedius group of animal pathogens

    Directory of Open Access Journals (Sweden)

    Nouri eBen Zakour

    2012-04-01

    Full Text Available The Staphylococcus intermedius group consists of 3 closely-related coagulase-positive bacterial species including S. intermedius, Staphylococus pseudintermedius, and Staphylococcus delphini. S. pseudintermedius is a major skin pathogen of dogs, which occasionally causes severe zoonotic infections of humans. S. delphini has been isolated from an array of different animals including horses, mink and pigeons, whereas S. intermedius has been isolated only from pigeons to date. Here we provide a detailed analysis of the S. pseudintermedius whole genome sequence in comparison to high quality draft S. intermedius and S. delphini genomes, and to other sequenced staphylococcal species. The core genome of the SIG was highly conserved with average nucleotide identity (ANI between the 3 species of 93.61%, which is very close to the threshold of species delineation (95% ANI, highlighting the close-relatedness of the SIG species. However, considerable variation was identified in the content of mobile genetic elements, cell wall-associated proteins, and iron and sugar transporters, reflecting the distinct ecological niches inhabited. Of note, S. pseudintermedius ED99 contained a Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR locus of the Nmeni subtype and S. intermedius contained both Nmeni and Mtube subtypes. In contrast to S. intermedius and S. delphini and most other staphylococci examined to date, S. pseudintermedius contained at least 9 predicted reverse transcriptase (RT Group II introns. Furthermore, S. pseudintermedius ED99 encoded several transposons which were largely responsible for its multi-resistant phenotype. Overall, the study highlights extensive differences in accessory genome content between closely-related staphylococcal species inhabiting distinct host niches, providing new avenues for research into pathogenesis and bacterial host-adaptation.

  5. A rare fungal species, Quambalaria cyanescens, isolated from a patient after augmentation mammoplasty--environmental contaminant or pathogen?

    Directory of Open Access Journals (Sweden)

    Xin Fan

    Full Text Available Some emerging but less common human fungal pathogens are known environmental species and could be of low virulence. Meanwhile, some species have natural antifungal drug resistance, which may pose significant clinical diagnosis and treatment challenges. Implant breast augmentation is one of the most frequently performed surgical procedures in China, and fungal infection of breast implants is considered rare. Here we report the isolation of a rare human fungal species, Quambalaria cyanescens, from a female patient in China. The patient had undergone bilateral augmentation mammoplasty 11 years ago and was admitted to Peking Union Medical College Hospital on 15 September 2011 with primary diagnosis of breast infection. She underwent surgery to remove the implant and fully recovered thereafter. During surgery, implants and surrounding tissues were removed and sent for histopathology and microbiology examination. Our careful review showed that there was no solid histopathologic evidence of infection apart from inflammation. However, a fungal strain, which was initially misidentified as "Candida tropicalis" because of the similar appearance on CHROMagar Candida, was recovered. The organism was later on re-identified as Q. cyanescens, based on sequencing of the rDNA internal transcribed spacer region rather than the D1/D2 domain of 26S rDNA. It exhibited high MICs to 5-flucytosine and all echinocandins, but appeared more susceptible to amphotericin B and azoles tested. The possible pathogenic role of Q. cyanescens in breast implants is discussed in this case, and the increased potential for misidentification of the isolate is a cause for concern as it may lead to inappropriate antifungal treatment.

  6. Doxycycline-regulated gene expression in the opportunistic fungal pathogen Aspergillus fumigatus

    Directory of Open Access Journals (Sweden)

    Askew David S

    2005-01-01

    Full Text Available Abstract Background Although Aspergillus fumigatus is an important human fungal pathogen there are few expression systems available to study the contribution of specific genes to the growth and virulence of this opportunistic mould. Regulatable promoter systems based upon prokaryotic regulatory elements in the E. coli tetracycline-resistance operon have been successfully used to manipulate gene expression in several organisms, including mice, flies, plants, and yeast. However, the system has not yet been adapted for Aspergillus spp. Results Here we describe the construction of plasmid vectors that can be used to regulate gene expression in A. fumigatus using a simple co-transfection approach. Vectors were generated in which the tetracycline transactivator (tTA or the reverse tetracycline transactivator (rtTA2s-M2 are controlled by the A. nidulans gpdA promoter. Dominant selectable cassettes were introduced into each plasmid, allowing for selection following gene transfer into A. fumigatus by incorporating phleomycin or hygromycin into the medium. To model an essential gene under tetracycline regulation, the E. coli hygromycin resistance gene, hph, was placed under the control of seven copies of the TetR binding site (tetO7 in a plasmid vector and co-transfected into A. fumigatus protoplasts together with one of the two transactivator plasmids. Since the hph gene is essential to A. fumigatus in the presence of hygromycin, resistance to hygromycin was used as a marker of hph reporter gene expression. Transformants were identified in which the expression of tTA conferred hygromycin resistance by activating expression of the tetO7-hph reporter gene, and the addition of doxycycline to the medium suppressed hygromycin resistance in a dose-dependent manner. Similarly, transformants were identified in which expression of rtTA2s-M2 conferred hygromycin resistance only in the presence of doxycycline. The levels of doxycycline required to regulate

  7. Effects of ozone exposure or fungal pathogen on white lupin leaves as determined by imaging of chlorophyll a fluorescence.

    Science.gov (United States)

    Guidi, Lucia; Mori, Sauro; Degl'Innocenti, Elena; Pecchia, Susanna

    2007-01-01

    Chlorophyll fluorescence has been used routinely to investigate photosynthetic activity in plants subjected to both biotic and abiotic stresses. The aim of this work was to compare the perturbations in photosynthesis induced by ozone and by a pathogen. By using a conventional fluorometer a similar response pattern was observed in inoculated and O(3)-fumigated leaves. The application of chlorophyll fluorescence imaging provided further detailed information on the spatial-temporal heterogeneity of the response of white lupin leaves to fungal pathogen or to ozone fumigation. In particular, 48 h after artificial inoculation with the necrotrophic fungal pathogen Pleiochaeta setosa, the leaves showed a remarkable alteration in PSII operating efficiency (Phi(PSII)), which affected the whole surface. Afterwards, the infection site was surrounded by a ring of increased photosynthetic activity. The response of ozonated leaves was quite different. The reduction in Phi(PSII) was already evident 24h after fumigation; moreover, a distinct heterogeneity of the fluorescence yield was observed and the major veins displayed a lowered Phi(PSII). PMID:17900916

  8. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    Directory of Open Access Journals (Sweden)

    Mari Narusaka

    Full Text Available Housaku Monogatari (HM is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods.

  9. Secretome analysis identifies potential virulence factors of Diplodia corticola, a fungal pathogen involved in cork oak (Quercus suber) decline.

    Science.gov (United States)

    Fernandes, Isabel; Alves, Artur; Correia, António; Devreese, Bart; Esteves, Ana Cristina

    2014-01-01

    The characterisation of the secretome of phytopathogenic fungi may contribute to elucidate the molecular mechanisms of pathogenesis. This is particularly relevant for Diplodia corticola, a fungal plant pathogen belonging to the family Botryosphaeriaceae, whose genome remains unsequenced. This phytopathogenic fungus is recognised as one of the most important pathogens of cork oak, being related to the decline of cork oak forests in the Iberian Peninsula. Unfortunately, secretome analysis of filamentous fungi is limited by the low protein concentration and by the presence of many interfering substances, such as polysaccharides, which affect the separation and analysis by 1D and 2D gel electrophoresis. We compared six protein extraction protocols concerning their suitability for further application with proteomic workflows. The protocols involving protein precipitation were the most efficient, with emphasis on TCA-acetone protocol, allowing us to identify the most abundant proteins on the secretome of this plant pathogen. Approximately 60% of the spots detected were identified, all corresponding to extracellular proteins. Most proteins identified were carbohydrate degrading enzymes and proteases that may be related to D. corticola pathogenicity. Although the secretome was assessed in a noninfection environment, potential virulence factors such as the putative glucan-β-glucosidase, neuraminidase, and the putative ferulic acid esterase were identified. The data obtained forms a useful basis for a deeper understanding of the pathogenicity and infection biology of D. corticola. Moreover, it will contribute to the development of proteomics studies on other members of the Botryosphaeriaceae.

  10. Polymorphic DNA sequences of the fungal honey bee pathogen Ascosphaera apis

    DEFF Research Database (Denmark)

    Jensen, Annette B; Welker, Dennis L; Kryger, Per;

    2012-01-01

    The pathogenic fungus Ascosphaera apis is ubiquitous in honey bee populations. We used the draft genome assembly of this pathogen to search for polymorphic intergenic loci that could be used to differentiate haplotypes. Primers were developed for five such loci, and the species specificities were...... for the world's most important pollinator: the honey bee and one of its most common pathogens....

  11. Animal Defenses against Infectious Agents: Is Damage Control More Important Than Pathogen Control?

    OpenAIRE

    Andrew F Read; Graham, Andrea L.; Lars Råberg

    2008-01-01

    The ability of hosts to withstand a given number of pathogens is a critical component of health. Now playing catch-up with plant biologists, animal biologists are starting to formally separate this form of defense from classical resistance.

  12. Fungal pathogen complexes associated with rambutan, longan and mango diseases in Puerto Rico

    Science.gov (United States)

    Different fungi have been associated with diseased inflorescences, leaves, and fruits of mango, rambutan and longan. During a fungal disease survey conducted between 2008 and 2013 at six orchards of rambutan and longan, and one orchard of mango in Puerto Rico, symptoms such as fruit rot, infloresc...

  13. Grazing preference of Ceratophysella sp. 1 (Collembola for Pseudoperonospora cubensis - fungal pathogen of Cucumis sativus

    Directory of Open Access Journals (Sweden)

    Andrzej Chlebicki

    2014-06-01

    Full Text Available Grazing preferences of collembolans Ceratophysella sp. 1 were noted. The collembolans feed on the sporangia of Pseudoperonospora cubensis growing on plants Cucumis sativus in greenhouses in Esfahan province in Iran. Sporangia of Pseudoperonospora cubensis were the preferred food of all fungal species noted in the alimental tract of the springtails. All digestive tracts of the springtails contained sporangia of P. cubensis.

  14. Leveraging a high resolution microfluidic assay reveals insights into pathogenic fungal spore germination.

    Science.gov (United States)

    Barkal, Layla J; Walsh, Naomi M; Botts, Michael R; Beebe, David J; Hull, Christina M

    2016-05-16

    Germination of spores into actively growing cells is a process essential for survival and pathogenesis of many microbes. Molecular mechanisms governing germination, however, are poorly understood in part because few tools exist for evaluating and interrogating the process. Here, we introduce an assay that leverages developments in microfluidic technology and image processing to quantitatively measure germination with unprecedented resolution, assessing both individual cells and the population as a whole. Using spores from Cryptococcus neoformans, a leading cause of fatal fungal disease in humans, we developed a platform to evaluate spores as they undergo morphological changes during differentiation into vegetatively growing yeast. The assay uses pipet-accessible microdevices that can be arrayed for efficient testing of diverse microenvironmental variables, including temperature and nutrients. We discovered that temperature influences germination rate, a carbon source alone is sufficient to induce germination, and the addition of a nitrogen source sustains it. Using this information, we optimized the assay for use with fungal growth inhibitors to pinpoint stages of germination inhibition. Unexpectedly, the clinical antifungal drugs amphotericin B and fluconazole did not significantly alter the process or timing of the transition from spore to yeast, indicating that vegetative growth and germination are distinct processes in C. neoformans. Finally, we used the high temporal resolution of the assay to determine the precise defect in a slow-germination mutant. Combining advances in microfluidics with a robust fungal molecular genetic system allowed us to identify and alter key temporal, morphological, and molecular events that occur during fungal germination. PMID:27026574

  15. Pathogenic Yet Environmentally Friendly? Black Fungal Candidates for Bioremediation of Pollutants : Geomicrobiology Journal

    NARCIS (Netherlands)

    Blasi, B.; Poyntner, C.; Rudavsky, T.; Prenafeta-Boldu, F. X.; De Hoog, S.; Tafer, H.; Sterflinger, K.

    2016-01-01

    A collection of 163 strains of black yeast-like fungi from the CBS Fungal Biodiversity Center (Utrecht, The Netherlands), has been screened for the ability to grow on hexadecane, toluene and polychlorinated biphenyl 126 (PCB126) as the sole carbon and energy source. These compounds were chosen as re

  16. Chemo-sensitization of fungal pathogens to antimicrobial agents using benzaldehyde analogs

    Science.gov (United States)

    Activity of conventional antifungal agents, fludioxonil, strobilurin and antimycinA, which target the oxidative and osmotic stress response systems, was elevated by co-application of certain analogs of benzaldehyde. Fungal tolerance to 2,3-dihydroxybenzaldehyde or 2,3-dihydroxybenzoic acid was foun...

  17. Behavioural defences in animals against pathogens and parasites: parallels with the pillars of medicine in humans

    OpenAIRE

    Benjamin L Hart

    2011-01-01

    No other theme in animal biology seems to be more central than the concept of employing strategies to survive and successfully reproduce. In nature, controlling or avoiding pathogens and parasites is an essential fitness strategy because of the ever-present disease-causing organisms. The disease-control strategies discussed here are: physical avoidance and removal of pathogens and parasites; quarantine or peripheralization of conspecifics that could be carrying potential pathogens; herbal med...

  18. Effects of temperature during soybean seed development on defense-related gene expression and fungal pathogen accumulation.

    Science.gov (United States)

    Upchurch, Robert G; Ramirez, Martha E

    2011-12-01

    Soybean [Glycine max (L.) Merr] plants were exposed to three temperature regimens during seed development to investigate the effect of temperature on the expression of eight defense-related genes and the accumulation of two fungal pathogens in inoculated seeds. In seeds prior to inoculation, either a day/night warm (34/26 °C) or a cool temperature (22/18 °C) relative to normal (26/22 °C) resulted in altered patterns of gene expression including substantially lower expression of PR1, PR3 and PR10. After seed inoculation with Cercospora kikuchii, pathogen accumulation was lowest in seeds produced at 22/18 °C in which of all defense genes, MMP2 was uniquely most highly induced. For seeds inoculated with Diaporthe phaseolorum, pathogen accumulation was lowest in seeds produced at 34/26 °C in which of all defense genes, PR10 was uniquely most highly induced. Our detached seed assays clearly demonstrated that the temperature regimens we applied during seed development produced significant changes in seed defense-related gene expression both pre- and post inoculation and our findings support the hypothesis that global climate change may alter plant-pathogen interactions and thereby potentially crop productivity.

  19. Common strategies for antigenic variation by bacterial, fungal and protozoan pathogens

    OpenAIRE

    Deitsch, Kirk W.; Lukehart, Sheila A.; Stringer, James R.

    2009-01-01

    The complex relationships between infectious organisms and their hosts often reflect the continuing struggle of the pathogen to proliferate and spread to new hosts, and the need of the infected individual to control and potentially eradicate the infecting population. In the case of mammals and the pathogens that infect them, a veritable “arms race” has ensued. A highly adapted immune system has evolved to control the proliferation of infectious organisms and the pathogens have developed corre...

  20. Genes Expressed in Grapevine Leaves Reveal Latent Wood Infection by the Fungal Pathogen Neofusicoccum parvum

    OpenAIRE

    Czemmel, Stefan; Galarneau, Erin R.; Travadon, Renaud; McElrone, Andrew J.; Cramer, Grant R; Baumgartner, Kendra

    2015-01-01

    Some pathogenic species of the Botryosphaeriaceae have a latent phase, colonizing woody tissues while perennial hosts show no apparent symptoms until conditions for disease development become favorable. Detection of these pathogens is often limited to the later pathogenic phase. The latent phase is poorly characterized, despite the need for non-destructive detection tools and effective quarantine strategies, which would benefit from identification of host-based markers in leaves. Neofusicoccu...

  1. Systems for eliminating pathogens from exhaust air of animal houses

    OpenAIRE

    Aarnink, A.J.A.; Landman, W.J.M.; Melse, R.W.; Huynh Thi Thanh Thuy

    2005-01-01

    Recent outbreaks of highly infectious viral diseases like swine fever and avian influenza in The Netherlands have shown that despite extensive bio-security measures aiming at minimizing physical contacts between farms, disease spread could not be halted. Dust in exhaust air from swine and chicken houses may provide a favorable environment in which these viruses and other pathogenic microorganisms can survive and be transported over long distances to other farms. In a field study and in an exp...

  2. Role of hydrogen peroxide during the interaction between the hemibiotrophic fungal pathogen Septoria tritici and wheat

    NARCIS (Netherlands)

    Shetty, N.P.; Mehrabi, R.; Lütken, H.; Haldrup, A.; Kema, G.H.J.

    2007-01-01

    Hydrogen peroxide (H2O2) is reported to inhibit biotrophic but benefit necrotrophic pathogens. Infection by necrotrophs can result in a massive accumulation of H2O2 in hosts. Little is known of how pathogens with both growth types are affected (hemibiotrophs). The hemibiotroph, Septoria tritici, inf

  3. Multicenter Outbreak of Infections by Saprochaete clavata, an Unrecognized Opportunistic Fungal Pathogen

    OpenAIRE

    Vaux, Sophie; Criscuolo, Alexis; Desnos-Ollivier, Marie; Diancourt, Laure; Tarnaud, Chloé; Vandenbogaert, Matthias; Brisse, Sylvain; Coignard, Bruno; Dromer, Françoise; ,; Garcia-Hermoso, Dea; Blanc, Catherine; Hoinard, Damien; Lortholary, Olivier; Bretagne, Stéphane

    2014-01-01

    ABSTRACT Rapidly fatal cases of invasive fungal infections due to a fungus later identified as Saprochaete clavata were reported in France in May 2012. The objectives of this study were to determine the clonal relatedness of the isolates and to investigate possible sources of contamination. A nationwide alert was launched to collect cases. Molecular identification methods, whole-genome sequencing (WGS), and clone-specific genotyping were used to analyze recent and historical isolates, and a c...

  4. Social and behavioral barriers to pathogen transmission in wild animal populations

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C.S.

    1988-12-31

    Disease and pathogens have been studied as regulators of animal populations but not really as selective forces. The authors propose that pathogens can be major selective forces influencing social behaviors when these are successful at reducing disease transmission. The behaviors whose evolution could have been influenced by pathogen effects include group size, group isolation, mixed species flocking, migration, seasonal sociality, social avoidance, and dominance behaviors. Mate choice, mating system, and sexual selection are put in a new light when examined in terms of disease transmission. It is concluded that pathogen avoidance is a more powerful selective force than has heretofore been recognized.

  5. Arranging the bouquet of disease: floral traits and the transmission of plant and animal pathogens.

    Science.gov (United States)

    McArt, Scott H; Koch, Hauke; Irwin, Rebecca E; Adler, Lynn S

    2014-05-01

    Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens deposited in flowers, we often lack a basic understanding of how floral traits influence disease transmission. Here, we provide the first systematic review regarding how floral traits attract vectors (for plant pathogens) or hosts (for animal pathogens), mediate disease establishment and evolve under complex interactions with plant mutualists that can be vectors for microbial antagonists. Attraction of floral visitors is influenced by numerous phenological, morphological and chemical traits, and several plant pathogens manipulate floral traits to attract vectors. There is rapidly growing interest in how floral secondary compounds and antimicrobial enzymes influence disease establishment in plant hosts. Similarly, new research suggests that consumption of floral secondary compounds can reduce pathogen loads in animal pollinators. Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research. We conclude by discussing important implications of floral transmission of pathogens for agriculture, conservation and human health, suggesting promising avenues for future research in both basic and applied biology. PMID:24528408

  6. Insight into trade-off between wood decay and parasitism from the genome of a fungal forest pathogen

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Ake; Aerts, Andrea; Asiegbu, Fred; Belbahri, Lassaad; Bouzid, Ourdia; Broberg, Anders; Canback, Bjorn; Coutinho, Pedro M.; Cullen, Dan; Dalman, Kerstin; Deflorio, Giuliana; van Diepen, Linda T. A.; Dunand, Christophe; Duplessis, Sebastien; Durling, Mikael; Gonthier, Paolo; Grimwood, Jane; Fossdal, Carl Gunnar; Hansson, David; Henrissat, Bernard; Hietala, Ari; Himmelstrand, Kajsa; Hoffmeister, Dirk; Hogberg, Nils; James, Timothy Y.; Karlsson, Magnus; Kohler, Annegret; Lucas, Susan; Lunden, Karl; Morin, Emmanuelle; Murat, Claude; Park, Jongsun; Raffaello, Tommaso; Rouze, Pierre; Salamov, Asaf; Schmutz, Jeremy; Solheim, Halvor; Stahlberg, Jerry; Velez, Heriberto; de Vries, Ronald P.; Wiebenga, Ad; Woodward, Steve; Yakovlev, Igor; Garbelotto, Matteo; Martin, Francis; Grigoriev, Igor V.; Stenlid, Jan

    2012-01-01

    Parasitism and saprotrophic wood decay are two fungal strategies fundamental for succession and nutrient cycling in forest ecosystems. An opportunity to assess the trade-off between these strategies is provided by the forest pathogen and wood decayer Heterobasidion annosum sensu lato. We report the annotated genome sequence and transcript profiling, as well as the quantitative trait loci mapping, of one member of the species complex: H. irregulare. Quantitative trait loci critical for pathogenicity, and rich in transposable elements, orphan and secreted genes, were identified. A wide range of cellulose-degrading enzymes are expressed during wood decay. By contrast, pathogenic interaction between H. irregulare and pine engages fewer carbohydrate-active enzymes, but involves an increase in pectinolytic enzymes, transcription modules for oxidative stress and secondary metabolite production. Our results show a trade-off in terms of constrained carbohydrate decomposition and membrane transport capacity during interaction with living hosts. Our findings establish that saprotrophic wood decay and necrotrophic parasitism involve two distinct, yet overlapping, processes.

  7. VALIDATION OF EMBRYO TESTS FOR DETERMINING EFFECTS OF FUNGAL PEST CONTROL AGENTS ON NONTARGET AQUATIC ANIMALS

    Science.gov (United States)

    Developing embryos of the inland silverside fish Menidia beryllina and grass shrimp Palaemonetes pugio were exposed to conidiospores of the fungal weed control agent, Colletotrichum gloeosporioides, f. sp. aeschynomene, and the entomopathogen, Metarhizium anisopliae. nly Metarhiz...

  8. A novel role for the NLRC4 inflammasome in mucosal defenses against the fungal pathogen Candida albicans.

    Directory of Open Access Journals (Sweden)

    Jeffrey Tomalka

    2011-12-01

    Full Text Available Candida sp. are opportunistic fungal pathogens that colonize the skin and oral cavity and, when overgrown under permissive conditions, cause inflammation and disease. Previously, we identified a central role for the NLRP3 inflammasome in regulating IL-1β production and resistance to dissemination from oral infection with Candida albicans. Here we show that mucosal expression of NLRP3 and NLRC4 is induced by Candida infection, and up-regulation of these molecules is impaired in NLRP3 and NLRC4 deficient mice. Additionally, we reveal a role for the NLRC4 inflammasome in anti-fungal defenses. NLRC4 is important for control of mucosal Candida infection and impacts inflammatory cell recruitment to infected tissues, as well as protects against systemic dissemination of infection. Deficiency in either NLRC4 or NLRP3 results in severely attenuated pro-inflammatory and antimicrobial peptide responses in the oral cavity. Using bone marrow chimeric mouse models, we show that, in contrast to NLRP3 which limits the severity of infection when present in either the hematopoietic or stromal compartments, NLRC4 plays an important role in limiting mucosal candidiasis when functioning at the level of the mucosal stroma. Collectively, these studies reveal the tissue specific roles of the NLRP3 and NLRC4 inflammasome in innate immune responses against mucosal Candida infection.

  9. Interactions between fungal plant pathogens on leaves. Especially simultaneous development of Rhynchosporium secalis and Drechslera teres on barley

    DEFF Research Database (Denmark)

    Vollmer, Jeanette Hyldal

    Plant diseases caused by fungi are major potential threats to yield in both organic and conventional cereal production, and generally several species of pathogenic fungi are found together on the same plants in the field. This PhD thesis concludes, thatinteraction between different foliar fungal...... species may influence total disease levels and often via negative effects. This implies that less disease is observed where several diseases occur together, relative to where they occur individually. Suchinteraction effects have often been ignored in the past, as plant diseases are traditionally studied...... the barley diseases scald (Rhynchosporium secalis) and net blotch (Drechslera teres). Aiming to understand how diseases interact in the field, it is concluded that increased focus should be placed on considering the dynamics of plant growth along with epidemiological development. This is pointed out...

  10. New fungal pathogens of the red ant, Myrmica rubra, from the UK and implications for ant invasions in the USA.

    Science.gov (United States)

    Evans, Harry C; Groden, Eleanor; Bischoff, Joseph F

    2010-01-01

    The red ant, Myrmica rubra, is an increasingly invasive pest species in north-eastern USA, where it is known as the European fire ant. During surveys for natural enemies in part of its native range in the UK, three previously unreported fungal pathogens developed on ants when incubated in the laboratory. These are described and illustrated: Paraisaria myrmicarum sp. nov., Hirsutella stilbelliformis var. myrmicarum var. nov., and Hirsutella subramanianii var. myrmicarum var. nov. Based on analyses of the protein coding region EF-1α and LSU rDNA, all three described taxa are shown to be affiliated with the hypocrealean family Ophiocordycipitaceae. The implications for the management of M. rubra in its exotic North American range using classical biological control are discussed. PMID:20943156

  11. Battle through signaling between wheat and the fungal pathogen Septoria tritici revealed by proteomics and phosphoproteomics

    DEFF Research Database (Denmark)

    Yang, Fen; Braga, Marcella Nunes de Melo; Larsen, Martin Røssel;

    2013-01-01

    The fungus Septoria tritici causes the disease septoria tritici blotch in wheat, one of the most economically devastating foliar diseases in this crop. To investigate signaling events and defense responses in the wheat-S. tritici interaction, we performed a time-course study of S. tritici infection......-binding proteins, 14-3-3 proteins, and calcium-binding proteins. Quantitative PCR analysis showed the expression of fungal signaling genes and genes encoding a superoxide dismutase and cell-wall degrading enzymes. These results indicate roles of signaling, antioxidative stress mechanisms, and nutrient acquisition...

  12. Comparison of different methods for extraction of DNA of fungal pathogens from cultures and blood.

    OpenAIRE

    Löffler, J; Hebart, H.; Schumacher, U; Reitze, H; Einsele, H

    1997-01-01

    Five commercially available extraction kits and an in-house DNA extraction method for the release of DNA from Candida albicans and Aspergillus niger cells were assessed for sensitivity, purity, duration, and cost. All commercially available kits helped to shorten the duration of DNA extraction. However, the sensitivity varied from 1 to 1,000 fungal cells/ml and costs varied from $0.10 to 2.30. The QIAmp Tissue kit was the commercially available assay that yielded the same sensitivity and puri...

  13. Singlet Molecular Oxygen Generation by Light-Activated DHN-Melanin of the Fungal Pathogen Mycosphaerella fijiensis in Black Sigatoka Disease of Bananas

    OpenAIRE

    Miguel J Beltrán-García; Prado, Fernanda M.; Marilene S Oliveira; David Ortiz-Mendoza; Alexsandra C Scalfo; Adalberto Pessoa; Medeiros, Marisa H. G.; White, James F.; Paolo Di Mascio

    2014-01-01

    In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg). Using analytical tools, including elemental analysis, ultraviolet/infrared absor...

  14. Insights from the genome of the biotrophic fungal plant pathogen Ustilago maydis.

    Science.gov (United States)

    Kämper, Jörg; Kahmann, Regine; Bölker, Michael; Ma, Li-Jun; Brefort, Thomas; Saville, Barry J; Banuett, Flora; Kronstad, James W; Gold, Scott E; Müller, Olaf; Perlin, Michael H; Wösten, Han A B; de Vries, Ronald; Ruiz-Herrera, José; Reynaga-Peña, Cristina G; Snetselaar, Karen; McCann, Michael; Pérez-Martín, José; Feldbrügge, Michael; Basse, Christoph W; Steinberg, Gero; Ibeas, Jose I; Holloman, William; Guzman, Plinio; Farman, Mark; Stajich, Jason E; Sentandreu, Rafael; González-Prieto, Juan M; Kennell, John C; Molina, Lazaro; Schirawski, Jan; Mendoza-Mendoza, Artemio; Greilinger, Doris; Münch, Karin; Rössel, Nicole; Scherer, Mario; Vranes, Miroslav; Ladendorf, Oliver; Vincon, Volker; Fuchs, Uta; Sandrock, Björn; Meng, Shaowu; Ho, Eric C H; Cahill, Matt J; Boyce, Kylie J; Klose, Jana; Klosterman, Steven J; Deelstra, Heine J; Ortiz-Castellanos, Lucila; Li, Weixi; Sanchez-Alonso, Patricia; Schreier, Peter H; Häuser-Hahn, Isolde; Vaupel, Martin; Koopmann, Edda; Friedrich, Gabi; Voss, Hartmut; Schlüter, Thomas; Margolis, Jonathan; Platt, Darren; Swimmer, Candace; Gnirke, Andreas; Chen, Feng; Vysotskaia, Valentina; Mannhaupt, Gertrud; Güldener, Ulrich; Münsterkötter, Martin; Haase, Dirk; Oesterheld, Matthias; Mewes, Hans-Werner; Mauceli, Evan W; DeCaprio, David; Wade, Claire M; Butler, Jonathan; Young, Sarah; Jaffe, David B; Calvo, Sarah; Nusbaum, Chad; Galagan, James; Birren, Bruce W

    2006-11-01

    Ustilago maydis is a ubiquitous pathogen of maize and a well-established model organism for the study of plant-microbe interactions. This basidiomycete fungus does not use aggressive virulence strategies to kill its host. U. maydis belongs to the group of biotrophic parasites (the smuts) that depend on living tissue for proliferation and development. Here we report the genome sequence for a member of this economically important group of biotrophic fungi. The 20.5-million-base U. maydis genome assembly contains 6,902 predicted protein-encoding genes and lacks pathogenicity signatures found in the genomes of aggressive pathogenic fungi, for example a battery of cell-wall-degrading enzymes. However, we detected unexpected genomic features responsible for the pathogenicity of this organism. Specifically, we found 12 clusters of genes encoding small secreted proteins with unknown function. A significant fraction of these genes exists in small gene families. Expression analysis showed that most of the genes contained in these clusters are regulated together and induced in infected tissue. Deletion of individual clusters altered the virulence of U. maydis in five cases, ranging from a complete lack of symptoms to hypervirulence. Despite years of research into the mechanism of pathogenicity in U. maydis, no 'true' virulence factors had been previously identified. Thus, the discovery of the secreted protein gene clusters and the functional demonstration of their decisive role in the infection process illuminate previously unknown mechanisms of pathogenicity operating in biotrophic fungi. Genomic analysis is, similarly, likely to open up new avenues for the discovery of virulence determinants in other pathogens. PMID:17080091

  15. Pulsed light for the inactivation of fungal biofilms of clinically important pathogenic Candida species.

    Science.gov (United States)

    Garvey, Mary; Andrade Fernandes, Joao Paulo; Rowan, Neil

    2015-07-01

    Microorganisms are naturally found as biofilm communities more than planktonic free-floating cells; however, planktonic culture remains the current model for microbiological studies, such as disinfection techniques. The presence of fungal biofilms in the clinical setting has a negative impact on patient mortality, as Candida biofilms have proved to be resistant to biocides in numerous in vitro studies; however, there is limited information on the effect of pulsed light on sessile communities. Here we report on the use of pulsed UV light for the effective inactivation of clinically relevant Candida species. Fungal biofilms were grown by use of a CDC reactor on clinically relevant surfaces. Following a maximal 72 h formation period, the densely populated biofilms were exposed to pulsed light at varying fluences to determine biofilm sensitivity to pulsed-light inactivation. The results were then compared to planktonic cell inactivation. High levels of inactivation of C. albicans and C. parapsilosis biofilms were achieved with pulsed light for both 48 and 72 h biofilm structures. The findings suggest that pulsed light has the potential to provide a means of surface decontamination, subsequently reducing the risk of infection to patients. The research described herein deals with an important aspect of disease prevention and public health.

  16. Evidence for synergistic activity of plant-derived essential oils against fungal pathogens of food.

    Science.gov (United States)

    Hossain, Farah; Follett, Peter; Dang Vu, Khang; Harich, Mehdi; Salmieri, Stephane; Lacroix, Monique

    2016-02-01

    The antifungal activities of eight essential oils (EOs) namely basil, cinnamon, eucalyptus, mandarin, oregano, peppermint, tea tree and thyme were evaluated for their ability to inhibit growth of Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus and Penicillium chrysogenum. The antifungal activity of the EOs was assessed by the minimum inhibitory concentration (MIC) using 96-well microplate analysis. The interactions between different EO combinations were done by the checkerboard technique. The highest antifungal activity was exhibited by oregano and thyme which showed lower MIC values amongst all the tested fungi. The antifungal activity of the other EOs could be appropriately ranked in a descending sequence of cinnamon, peppermint, tea tree and basil. Eucalyptus and mandarin showed the least efficiency as they could not inhibit any of the fungal growth at 10,000 ppm. The interaction between these two EOs also showed no interaction on the tested species. A combined formulation of oregano and thyme resulted in a synergistic effect, showing enhanced efficiency against A. flavus and A. parasiticus and P. chrysogenum. Mixtures of peppermint and tea tree produced synergistic effect against A. niger. Application of a modified Gompertz model considering fungal growth parameters like maximum colony diameter, maximum growth rate and lag time periods, under the various EO treatment scenarios, showed that the model could adequately describe and predict the growth of the tested fungi under these conditions. PMID:26678126

  17. Gene-specific markers for the wheat gene Lr34/Yr18/Pm38 which confers resistance to multiple fungal pathogens

    Science.gov (United States)

    The locus Lr34/Yr18/Pm38 confers partial and durable resistance against the devastating fungal pathogens leaf rust, stripe rust, and powdery mildew. In previous studies, this broad-spectrum resistance was shown to be controlled by a single gene which encodes a putative ATP-binding cassette transport...

  18. Production of anti-fungal volatiles by non-pathogenic Fusarium oxysporum and its efficacy in suppression of verticillium wilt of cotton

    Science.gov (United States)

    Aims: The study aimed to identify volatile organic compounds (VOCs) produced by the non-pathogenic Fusarium oxysporum (Fo) strain CanR-46, and to determine the anti-fungal spectrum and the control efficacy of the Fo-VOCs. Methods: The Fo-VOCs were identified by GC-MS. The antifungal activity of the...

  19. A novel virus that infecting hypovirulent strain XG36-1 of plant fungal pathogen Sclerotinia sclerotiorum

    Directory of Open Access Journals (Sweden)

    Jiang Daohong

    2009-07-01

    Full Text Available Abstract Background Sclerotinia sclerotiorum is a notorious plant fungal pathogen which spreads across the world. Hypovirulence is a phenomenon where the virulence of fungal pathogens is decreased, even lost, due to mycovirus infection. The potential of hypoviruses for biological control of the chestnut blight fungus (Cryphonectria parasitica has attracted much interest, and has led to discovery of new hypovirulent strains in other fungi. Results A hypovirulent strain, strain XG36-1, was isolated from a typical lesion on the stem of rapeseed (Brassica napus caused by Sclerotinia sclerotiorum. Strain XG36-1 grew on PDA very slowly (average 2.5 ± 0.1 mm/d with sectoring, and developed abnormal colony morphology with few sclerotia. Unlike health strains (such as wildtype strain XG-13, it was unable to induce lesions on detached leaves of rapeseed. Sclerotia of strain XG36-1 produced apothecia rarely. A sexual progeny test showed that the phenotypes of all 104 sexual progeny were not different from wildtype strain XG-13 which shows normal phenotype of S. sclerotiorum, and protoplast regeneration tests showed that 25.5% of the regenerants of strain XG36-1 were recovered fully. Furthermore, the hypovirulence and its associated traits could be transmitted to XG36-1A34R, a hygromycin-resistance gene labelled sexual progeny of strain XG36-1, by hyphal anastomosis. Transmission electron microscope (TEM observation showed that the cytoplasm of strain XG36-1 was destroyed and granulated; the membranes of nuclei and mitochondria were disintegrated; and mitochondrial cristae were cavitated. Viral particles (about 40 nm in hyphae of strain XG36-1, but not in its sexual progeny and wildtype strain XG-13, could be observed with TEM, and several virus-like particles were uniquely enveloped by single layer membrane in the cells of strain XG36-1. Furthermore, the viral particles could be co-transmitted with the hypovirulence traits through hyphal anastomosis

  20. Genes expressed in grapevine leaves reveal latent wood infection by the fungal pathogen Neofusicoccum parvum.

    Directory of Open Access Journals (Sweden)

    Stefan Czemmel

    Full Text Available Some pathogenic species of the Botryosphaeriaceae have a latent phase, colonizing woody tissues while perennial hosts show no apparent symptoms until conditions for disease development become favorable. Detection of these pathogens is often limited to the later pathogenic phase. The latent phase is poorly characterized, despite the need for non-destructive detection tools and effective quarantine strategies, which would benefit from identification of host-based markers in leaves. Neofusicoccum parvum infects the wood of grapevines and other horticultural crops, killing the fruit-bearing shoots. We used light microscopy and high-resolution computed tomography (HRCT to examine the spatio-temporal relationship between pathogen colonization and anatomical changes in stem sections. To identify differentially-expressed grape genes, leaves from inoculated and non-inoculated plants were examined using RNA-Seq. The latent phase occurred between 0 and 1.5 months post-inoculation (MPI, during which time the pathogen did not spread significantly beyond the inoculation site nor were there differences in lesion lengths between inoculated and non-inoculated plants. The pathogenic phase occurred between 1.5 and 2 MPI, when recovery beyond the inoculation site increased and lesion lengths of inoculated plants tripled. By 2 MPI, inoculated plants also had decreased starch content in xylem fibers and rays, and increased levels of gel-occluded xylem vessels, the latter of which HRCT revealed at a higher frequency than microscopy. RNA-Seq and screening of 21 grape expression datasets identified 20 candidate genes that were transcriptionally-activated by infection during the latent phase, and confirmed that the four best candidates (galactinol synthase, abscisic acid-induced wheat plasma membrane polypeptide-19 ortholog, embryonic cell protein 63, BURP domain-containing protein were not affected by a range of common foliar and wood pathogens or abiotic stresses

  1. Genes expressed in grapevine leaves reveal latent wood infection by the fungal pathogen Neofusicoccum parvum.

    Science.gov (United States)

    Czemmel, Stefan; Galarneau, Erin R; Travadon, Renaud; McElrone, Andrew J; Cramer, Grant R; Baumgartner, Kendra

    2015-01-01

    Some pathogenic species of the Botryosphaeriaceae have a latent phase, colonizing woody tissues while perennial hosts show no apparent symptoms until conditions for disease development become favorable. Detection of these pathogens is often limited to the later pathogenic phase. The latent phase is poorly characterized, despite the need for non-destructive detection tools and effective quarantine strategies, which would benefit from identification of host-based markers in leaves. Neofusicoccum parvum infects the wood of grapevines and other horticultural crops, killing the fruit-bearing shoots. We used light microscopy and high-resolution computed tomography (HRCT) to examine the spatio-temporal relationship between pathogen colonization and anatomical changes in stem sections. To identify differentially-expressed grape genes, leaves from inoculated and non-inoculated plants were examined using RNA-Seq. The latent phase occurred between 0 and 1.5 months post-inoculation (MPI), during which time the pathogen did not spread significantly beyond the inoculation site nor were there differences in lesion lengths between inoculated and non-inoculated plants. The pathogenic phase occurred between 1.5 and 2 MPI, when recovery beyond the inoculation site increased and lesion lengths of inoculated plants tripled. By 2 MPI, inoculated plants also had decreased starch content in xylem fibers and rays, and increased levels of gel-occluded xylem vessels, the latter of which HRCT revealed at a higher frequency than microscopy. RNA-Seq and screening of 21 grape expression datasets identified 20 candidate genes that were transcriptionally-activated by infection during the latent phase, and confirmed that the four best candidates (galactinol synthase, abscisic acid-induced wheat plasma membrane polypeptide-19 ortholog, embryonic cell protein 63, BURP domain-containing protein) were not affected by a range of common foliar and wood pathogens or abiotic stresses. Assuming such host

  2. Differential IL-17 production and mannan recognition contribute to fungal pathogenicity and commensalism.

    NARCIS (Netherlands)

    Rizzetto, L.; Kuka, M.; Filippo, C. De; Cambi, A.; Netea, M.G.; Beltrame, L.; Napolitani, G.; Torcia, M.G.; D'Oro, U.; Cavalieri, D.

    2010-01-01

    In this study, we present evidence of differential Th17 responses in human monocyte-derived dendritic cells exposed to the pathogenic Candida albicans or the nonpathogenic Saccharomyces cerevisiae. We use different forms of the microorganisms, cells, hyphae, and spores, as a toolbox to dissect the r

  3. Genes expressed in grapevine leaves reveal latent wood infection by the fungal pathogen Neofusicoccum parvum

    Science.gov (United States)

    Detection of wood-infecting pathogens is often limited to the late stage of infection, when disease symptoms are obvious. Detection of the early stage of infection would benefit from identification of host-based markers in asymptomatic leaves. The fungus Neofusicoccum parvum (Botryosphaeria diebac...

  4. Comparative genomics of the fungal pathogens Candida dubliniensis and Candida albicans.

    LENUS (Irish Health Repository)

    Jackson, Andrew P

    2009-12-01

    Candida dubliniensis is the closest known relative of Candida albicans, the most pathogenic yeast species in humans. However, despite both species sharing many phenotypic characteristics, including the ability to form true hyphae, C. dubliniensis is a significantly less virulent and less versatile pathogen. Therefore, to identify C. albicans-specific genes that may be responsible for an increased capacity to cause disease, we have sequenced the C. dubliniensis genome and compared it with the known C. albicans genome sequence. Although the two genome sequences are highly similar and synteny is conserved throughout, 168 species-specific genes are identified, including some encoding known hyphal-specific virulence factors, such as the aspartyl proteinases Sap4 and Sap5 and the proposed invasin Als3. Among the 115 pseudogenes confirmed in C. dubliniensis are orthologs of several filamentous growth regulator (FGR) genes that also have suspected roles in pathogenesis. However, the principal differences in genomic repertoire concern expansion of the TLO gene family of putative transcription factors and the IFA family of putative transmembrane proteins in C. albicans, which represent novel candidate virulence-associated factors. The results suggest that the recent evolutionary histories of C. albicans and C. dubliniensis are quite different. While gene families instrumental in pathogenesis have been elaborated in C. albicans, C. dubliniensis has lost genomic capacity and key pathogenic functions. This could explain why C. albicans is a more potent pathogen in humans than C. dubliniensis.

  5. Meiosis Drives Extraordinary Genome Plasticity in the Haploid Fungal Plant Pathogen Mycosphaerella Graminicola

    Science.gov (United States)

    Meiosis in the plant-pathogenic fungus Mycosphaerella graminicola results in eight ascospores due to a mitotic division following the two meiotic divisions. The transient diploid phase allows for recombination among homologous chromosomes. However, some chromosomes of M. graminicola lack homologs an...

  6. Deciphering Metabolic Traits of the Fungal Pathogen Aspergillus fumigatus: Redundancy vs. Essentiality

    Directory of Open Access Journals (Sweden)

    Jorge eAmich

    2012-12-01

    Full Text Available Incidence rates of infections caused by environmental opportunistic fungi have risen over recent decades. Aspergillus species have emerged as serious threat for the immune-compromised, and detailed knowledge about virulence-determining traits is crucial for drug target identification. As a prime saprobe, A. fumigatus has evolved to efficiently adapt to various stresses and to sustain nutritional supply by osmotrophy, which is characterized by extracellular substrate digestion followed by efficient uptake of breakdown products that are then fed into the fungal primary metabolism. These intrinsic metabolic features are believed to be related with its virulence ability. The plethora of genes that encode underlying effectors has hampered their in-depth analysis with respect to pathogenesis. Recent developments in Aspergillus molecular biology allow conditional gene expression or comprehensive targeting of gene families to cope with redundancy. Furthermore, identification of essential genes that are intrinsically connected to virulence opens accurate perspectives for novel targets in antifungal therapy.

  7. Ovicidal activity of two fungal pathogens (Hyphomycetes) against Tetranychus cinnabarinus (Acarina:Tetranichidae)

    Institute of Scientific and Technical Information of China (English)

    SHI Weibin; FENG Mingguang

    2004-01-01

    The carmine spider mite, Tetranychus cinnabarinus, is an economically important pest that devastates varieties of crops worldwide and develops significant resistance to common chemical pesticides, most of which lack ovicidal activity. In the present study, two isolates of entomopathogenic fungi, Beuaveria bassiana SG8702 and Paecilomyces fumosoroseus Pfr153, were bioassayed against T. cinnabarinus eggs at 25℃ under a photophase of 12∶12 (L∶D). Infected eggs on Vicia faba var. minor leaves failed to hatch due to distortion and shrinkage and had fungal outgrowths when maintained under moist conditions. Sprays of B. bassiana conidia to T. cinnabarinus eggs (on leaves) at the concentrations of 58, 298 and 1306 conidia/mm2 (3 replicates per concentration and 35-65 fresh mite eggs per replicate) resulted in corrected egg mortalities of 20.4±4.2%, 36.0±7.6% and 64.6(12.5% (F=43.14, P <0.01), respectively; sprays of P. fumosoroseus at 129, 402 and 2328 conidia/mm2 caused egg mortalities of 16.1±11.1%, 44.2±13.3%, and 63.4±11.7% (F= 15.37, P=0.01), respectively. In contrast, natural egg mortalities in blank controls were 7.8% and 10.3% only. Based on probit analysis, the estimates of LC50 with 95% confidential limits were 548 (393-858) conidia/mm2 for B. bassiana and 914 (625-1550) for P. fumosoroseus, respectively. Apparently, both fungal species were capable of infecting T. cinnabarinus eggs, but the ovicidal activity of the B. bassiana isolate was greater than that of the P. fumosoroseus isolate. This represents the first report on the ovicidal activity of the two entomopathogenic Hyphomycetes against T. cinnabarinus.

  8. Fungistatic activity of iron-free bovin lactoferrin against several fungal plant pathogens and antagonists.

    Science.gov (United States)

    Lahoz, Ernesto; Pisacane, Anna; Iannaccone, Marco; Palumbo, Daniela; Capparelli, Rosanna

    2008-01-01

    Lactoferrin (LF) is a member of the transferrin family of iron-binding glycoproteins. It is also a multifunctional protein of 80 kDa that is synthesized by glandular epithelial cells and secreted into mucosal fluid. High levels of LF are present in colostrom and milk and low levels in tears, saliva, and gastrointestinal and reproductive secretions. Data regarding the antifungal effects of LF are limited. Studies have been performed on Candida albicans, which demonstrated that LF inhibits the growth of this fungus. This study reports the results of experiments carried out in order to evaluate the effects of LF on the growth of 11 fungi, which were isolated from plants and soils. These experiments employed the methods of amended agar utilizing nine different concentration levels of LF (0, 0.001, 0.01, 0.1, 1, 10, 100, 1000, 5000 mg L(-1)). The effects of LF on the growth of these fungi were based on measures of the radial growth of the fungal colonies expressed both as percentage of inhibition and as IC(50) values (the concentration at which the fungal growth was inhibited by 50% relative to controls). LF had no effects on Alternaria alternata, Gliocladium roseum, Fusarium solani and Colletotrichum lindemuthianum. It did, however, inhibit the growth of Aspergillus niger, Trichoderma viride, Sclerotinia sclerotiorum, Sclerotium rolfsii, Rhizoctonia solani and Phoma exigua to the point that their IC(50) values ranged from 31.1 mg L(-1) for S. sclerotiorum to 952 mg L(-1) for T. viride. PMID:18629710

  9. Generation of IL-23 producing dendritic cells (DCs by airborne fungi regulates fungal pathogenicity via the induction of T(H-17 responses.

    Directory of Open Access Journals (Sweden)

    Georgios Chamilos

    Full Text Available Interleukin-17 (IL-17 producing T helper cells (T(H-17 comprise a newly recognized T cell subset with an emerging role in adaptive immunity to a variety of fungi. Whether different airborne fungi trigger a common signaling pathway for T(H-17 induction, and whether this ability is related to the inherent pathogenic behavior of each fungus is currently unknown. Here we show that, as opposed to primary pathogenic fungi (Histoplasma capsulatum, opportunistic fungal pathogens (Aspergillus and Rhizopus trigger a common innate sensing pathway in human dendritic cells (DCs that results in robust production of IL-23 and drives T(H-17 responses. This response requires activation of dectin-1 by the fungal cell wall polysaccharide b-glucan that is selectively exposed during the invasive growth of opportunistic fungi. Notably, unmasking of b-glucan in the cell wall of a mutant of Histoplasma not only abrogates the pathogenicity of this fungus, but also triggers the induction of IL-23 producing DCs. Thus, b-glucan exposure in the fungal cell wall is essential for the induction of IL-23/T(H-17 axis and may represent a key factor that regulates protective immunity to opportunistic but not pathogenic fungi.

  10. Transformation of the Fungal Soybean Pathogen Cercospora kikuchii with the Selectable Marker bar.

    Science.gov (United States)

    Upchurch, R G; Meade, M J; Hightower, R C; Thomas, R S; Callahan, T M

    1994-12-01

    An improved transformation protocol, utilizing selection for resistance to the herbicide bialaphos, has been developed for the plant pathogenic fungus Cercospora kikuchii. Stable, bialaphos-resistant transformants are recovered at frequencies eight times higher than those achieved with the previous system that was based on selection for benomyl resistance. In addition to C. kikuchii, this improved method can also be used to transform other species of Cercospora.

  11. Fungal Control of Pathogenic Fungi Isolated From Some Wild Plants in Taif Governorate, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abou-Zeid, A. M.

    2008-01-01

    Full Text Available Twenty two plants were collected from Taif Governorate and identified as: Aerva lanata, Arnebia hispidissima, Artemisia judaica, Artemisia monosperma, Asphodelus aestives, Avena barbata, Capparis dcidua, Eucalyptus globulus, Euphorbia glomerifera, Foeniculum vulgare, Forsskaolea tenacissima, Juniperus procera, Launaea mucronata, Launaea sonchoides, Medicago sativa, Opuntia ficus, Phagnalon sinaicum, Prunus persica, Pulicaria crispa, Punica granatum, Rumex dentatus and Trichodesma calathiforme. Pathogenic fungi were isolated from some of these plants and identified as Alternaria alternata, Cephalosporium madurae, Cladosporium herbarum, Fusarium oxysporum, Humicola grisea, Penicillium chrysogenum and Ulocladium botrytis. Four antagonistic isolates were tested, 2 from Gliocladium fungus and 2 from Trichoderma fungus. We found that all the four antagonistic isolates (G. deliquescens, G. virens, T. viride and T. hamatum significantly inhibited the radial growth of the pathogenic fungi tested, with different ratios. The results indicated that the antibiotics produced by the antagonists were more effective than the fungus itself and differ with different fungi. Coating plant stems with antagonists or with antagonist extracts reduce the severity of the disease but not prevent it in all tested pathogens.

  12. Fungal pathogens and antagonists in root-soil zone in organic and integrated systems of potato production

    Directory of Open Access Journals (Sweden)

    Lenc Leszek

    2016-04-01

    Full Text Available Occurrence of culturable Fungi and Oomycota in root-soil habitat of potato cv. Owacja in organic and integrated production systems at Osiny (northern Poland was compared in 2008-2010. The densities of both pathogens were significantly greater in the organic system. The eudominant fungal taxa (with frequency > 10% in at least one habitat included species of Fusarium + Gibberella + Haematonectria, Penicillium, Phoma and Trichoderma. The dominant taxa (with frequency 5-10% included species from 13 genera. In the rhizoplane, rhizosphere and non-rhizosphere soil, the total density of potential pathogens was greater in the integrated system, and of potential antagonists in the organic system. Among eudominant and dominant pathogens, Fusarium oxysporum and Gibellulopsis nigrescens occurred at greater density in the integrated system and Haematonectria haematococca and Phoma spp. in the organic system. Among eudominant antagonists, Trichoderma species occurred at greater density in the organic system. The organic system provided more disease suppressive habitat than the integrated system. The occurrence of brown leaf spot and potato blight was however similar in both systems. The mean yield of organic potatoes (24.9 t · ha-1 was higher than the mean organic potato yield in Poland (21.0 t · ha-1 and similar to the mean in other European countries (Germany 25.1 t · ha-1, Great Britain 25.0 t · ha-1. The organic system, based on a 5-year rotation, with narrow-leafed lupin, white mustard and buckwheat as a cover crop, inorganic fertilization based on ground rock phosphate + potassium sulphate, and biological and chemical control of insects and diseases (Bacillus thuringiensis ssp. tenebrionis + copper hydroxide + copper oxychloride, may be recommended for use in central Europe.

  13. Foliar treatments with Gaultheria procumbens essential oil induce defence responses and resistance against a fungal pathogen in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Sophie eVergnes

    2014-09-01

    Full Text Available Essential oil from Gaultheria procumbens is mainly composed of methylsalicylate (>96%, a compound which can be metabolized in plant tissues to salicylic acid, a phytohormone inducing plant immunity against microbial pathogens. The potential use of G. procumbens essential oil as a biocontrol agent was evaluated on the model plant Arabidopsis thaliana. Expression of a selection of defence genes was detected 1, 6 and 24 hours after essential oil treatment (0.1 ml/L using a high-throughput qPCR-based microfluidic technology. Control treatments included methyl jasmonate and a commercialized salicylic acid analog, benzo(1,2,3-thiadiazole-7carbothiolic acid (BTH. Strong induction of defence markers known to be regulated by the salicylic acid pathway was observed after the treatment with G. procumbens essential oil. Treatment induced the accumulation of total salicylic acid in the wild -type Arabidopsis line Col-0 and analysis of the Arabidopsis line sid2, mutated in a salicylic acid biosynthetic gene, revealed that approximately 30% of methylsalicylate sprayed on the leaves penetrated inside plant tissues and was demethylated by endogenous esterases. Induction of plant resistance by G. procumbens essential oil was tested following inoculation with a GFP-expressing strain of the Arabidopsis fungal pathogen Colletotrichum higginsianum. Flurorescence measurement of infected tissues revealed that treatments led to a strong reduction (60% of pathogen development and that the efficacy of the G. procumbens essential oil was similar to the commercial product BION®. Together, these results show that the G. procubens essential oil is a natural source of methylsalicylate which can be formulated to develop new biocontrol products.

  14. Transgenic Indian Cotton (Gossypium hirsutum Harboring Rice Chitinase Gene (Chi II Confers Resistance to Two Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    M. Ganesan

    2009-01-01

    Full Text Available Problem statement: The present investigation described a simple and reproducible protocol for transgenic cotton regeneration and characterization of chitinase (Chi II gene expression against two different fungal pathogens in cotton. Approach: Transgenic cotton (Gossypium hirsutum cv. SVPR2 plants were produced by pCambia-bar-Chi II (13.8 kb under the control of the CaMV 35S promoter, harbored in the strain LBA 4404 Agrobacterium tumefaciens by using shoot tip explants. Results: Finally, from the 10 experiments, 21.8% of transformation frequency was recorded. Segregation ratio of 3:1 was recorded in the T0 plant seeds. Polymerase chain reaction and southern blotting analysis were used to confirm the integration of Chi II transgene in the T0 plants genome of putative transgenics. Quantitiave and qualitative (SDS-PAGE analyses were also carried out to confirm the expression of chitinase enzyme in T0 plants. Further, randomly selected transgenic plants (T0 were analyzed for disease tolerance by evaluating them with spores of Fusarium oxysporum and Alternaria macrospora. All the selected PCR positive plants showed enhanced disease resistance against Fusarium wilt. The plants selected randomly showed an enhanced survival rate compared with the control when they were grown in earthen pots inoculated with 1×105 spores 100-1 g of soil mixture. Another four randomly selected plantlets were sprayed with spores of Alternaria macrospora in order to test their tolerance to Alternaria leaf spot disease. After 20 days of culture, the number of lesions per leaf and the lesion length per leaf spot in non-transferred leaves increased. In the case of transgenic plantlets, lesion formation was completely absent. Conclusion: The disease resistance against Fusarium wilt and Alternaria leaf spot in cotton strains would serve as good breeding materials for producing fungal disease resistant cotton varieties.

  15. DNA-based detection of the fungal pathogen Geomyces destructans in soil from bat hibernacula

    Science.gov (United States)

    Lindner, Daniel L.; Gargas, Andrea; Lorch, Jeffrey M.; Banik, Mark T.; Glaeser, Jessie; Kunz, Thomas H.; Blehert, David S.

    2011-01-01

    White-nose syndrome (WNS) is an emerging disease causing unprecedented morbidity and mortality among bats in eastern North America. The disease is characterized by cutaneous infection of hibernating bats by the psychrophilic fungus Geomyces destructans. Detection of G. destructans in environments occupied by bats will be critical for WNS surveillance, management and characterization of the fungal lifecycle. We initiated an rRNA gene region-based molecular survey to characterize the distribution of G. destructans in soil samples collected from bat hibernacula in the eastern United States with an existing PCR test. Although this test did not specifically detect G. destructans in soil samples based on a presence/absence metric, it did favor amplification of DNA from putative Geomyces species. Cloning and sequencing of PCR products amplified from 24 soil samples revealed 74 unique sequence variants representing 12 clades. Clones with exact sequence matches to G. destructans were identified in three of 19 soil samples from hibernacula in states where WNS is known to occur. Geomyces destructans was not identified in an additional five samples collected outside the region where WNS has been documented. This study highlights the diversity of putative Geomyces spp. in soil from bat hibernacula and indicates that further research is needed to better define the taxonomy of this genus and to develop enhanced diagnostic tests for rapid and specific detection of G. destructans in environmental samples.

  16. Inhibition of fungal plant pathogens by synergistic action of chito-oligosaccharides and commercially available fungicides.

    Directory of Open Access Journals (Sweden)

    Md Hafizur Rahman

    Full Text Available Chitosan is a linear heteropolymer consisting of β 1,4-linked N-acetyl-D-glucosamine (GlcNAc and D-glucosamine (GlcN. We have compared the antifungal activity of chitosan with DPn (average degree of polymerization 206 and FA (fraction of acetylation 0.15 and of enzymatically produced chito-oligosaccharides (CHOS of different DPn alone and in combination with commercially available synthetic fungicides, against Botrytis cinerea, the causative agent of gray mold in numerous fruit and vegetable crops. CHOS with DPn in the range of 15-40 had the greatest anti-fungal activity. The combination of CHOS and low dosages of synthetic fungicides showed synergistic effects on antifungal activity in both in vitro and in vivo assays. Our study shows that CHOS enhance the activity of commercially available fungicides. Thus, addition of CHOS, available as a nontoxic byproduct of the shellfish industry, may reduce the amounts of fungicides that are needed to control plant diseases.

  17. Patterns of colonization and spread in the fungal spruce pathogen Onnia tomentosa.

    Science.gov (United States)

    Germain, H; Bergeron, M-J; Bernier, L; Laflamme, G; Hamelin, R C

    2009-11-01

    The basidiomycetous fungus Onnia tomentosa is one of the most widespread root rot pathogens in North America. Although the disease is more severe on spruce and pine trees, this pathogen can infect several coniferous species. To study the population structure of O. tomentosa, we harvested 180 basidiocarps in a 45-year-old white spruce plantation in western Quebec in autumn 1997 and extracted DNA directly from individual basidiocarps. Using a combination of spatial coordinates and molecular data based on the analysis of two mitochondrial and three nuclear loci, we measured the average genet size and molecular diversity and assessed the relative contribution of basidiospores and vegetative growth to the stand colonization. Most of the sampled basidiocarps that clustered spatially belonged to the same genet. A total of 37 discrete multilocus genets of an average size of 3.42 m were obtained. The genet size distribution was skewed towards smaller genets (3 m). The nuclear loci were in Hardy-Weinberg equilibrium in the larger genets, but not in the smaller genets, which displayed a deficiency of heterozygotes. This suggests a Wahlund effect, whereby different colonization events resulted in expected heterozygosity higher than observed heterozygosity. Using an estimate of the growth rate of the fungus, only a few of the largest genets were approximately the age of the plantation. These observations are consistent with the colonization by basidiospores subsequent to site preparation and tree planting followed by secondary colonization events and vegetative spread. PMID:19804376

  18. Horizontal gene transfer drives adaptive colonization of apple trees by the fungal pathogen Valsa mali

    Science.gov (United States)

    Yin, Zhiyuan; Zhu, Baitao; Feng, Hao; Huang, Lili

    2016-01-01

    Horizontal gene transfer (HGT) often has strong benefits for fungi. In a study of samples from apple canker in Shaanxi Province, China, diverse microbes, along with the necrotrophic pathogen Valsa mali, were found to colonize the apple bark, thus providing ample opportunity for HGT to occur. In the present study, we identified 32 HGT events in V. mali by combining phyletic distribution-based methods with phylogenetic analyses. Most of these HGTs were from bacteria, whereas several others were from eukaryotes. Three HGTs putatively functioned in competition with actinomycetes, some of which showed a significant inhibitory effect on V. mali. Three HGTs that were probably involved in nitrogen uptake were also identified. Ten HGTs were thought to be involved in pathogenicity because they were related to known virulence factors, including cell wall-degrading enzymes and candidate effector proteins. HGT14, together with HGT32, was shown to contribute to bleomycin resistance of V. mali.These results suggest that HGT drives the adaptive evolution of V. mali. The HGTs identified here provide new clues for unveiling the adaptation mechanisms and virulence determinants of V. mali. PMID:27634406

  19. Draft Genome Sequence of the Animal and Human Pathogen Malassezia pachydermatis Strain CBS 1879

    Science.gov (United States)

    Triana, Sergio; González, Andrés; Ohm, Robin A.; Wösten, Han A. B.; de Cock, Hans; Restrepo, Silvia

    2015-01-01

    Malassezia pachydermatis is a basidiomycetous yeast that causes infections in humans and animals. Here, we report the genome sequence of Malassezia pachydermatis strain CBS 1879, which will facilitate the study of mechanisms underlying pathogenicity of the only non-lipid-dependent Malasezzia species. PMID:26472839

  20. Water reclamation and value-added animal feed from corn-ethanol stillage by fungal processing.

    Science.gov (United States)

    Rasmussen, M L; Khanal, S K; Pometto, A L; van Leeuwen, J Hans

    2014-01-01

    Rhizopus oligosporus was cultivated on thin stillage from a dry-grind corn ethanol plant. The aim of the research was to develop a process to replace the current energy-intensive flash evaporation and make use of this nutrient-rich stream to create a new co-product in the form of protein-rich biomass. Batch experiments in 5- and 50-L stirred bioreactors showed prolific fungal growth under non-sterile conditions. COD, suspended solids, glycerol, and organic acids removals, critical for in-plant water reuse, reached ca. 80%, 98%, 100% and 100%, respectively, within 5 d of fungal inoculation, enabling effluent recycle as process water. R. oligosporus contains 2% lysine, good levels of other essential amino acids, and 43% crude protein - a highly nutritious livestock feed. Avoiding water evaporation from thin stillage would furthermore save substantial energy inputs on corn ethanol plants.

  1. Potential of Pseudomonas putida PCI2 for the Protection of Tomato Plants Against Fungal Pathogens.

    Science.gov (United States)

    Pastor, Nicolás; Masciarelli, Oscar; Fischer, Sonia; Luna, Virginia; Rovera, Marisa

    2016-09-01

    Tomato is one of the most economically attractive vegetable crops due to its high yields. Diseases cause significant losses in tomato production worldwide. We carried out Polymerase Chain Reaction studies to detect the presence of genes encoding antifungal compounds in the DNA of Pseudomonas putida strain PCI2. We also used liquid chromatography-electrospray tandem mass spectrometry to detect and quantify the production of compounds that increase the resistance of plants to diseases from culture supernatants of PCI2. In addition, we investigated the presence of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase in PCI2. Finally, PCI2 was used for inoculation of tomato seeds to study its potential biocontrol activity against Fusarium oxysporum MR193. The obtained results showed that no fragments for the encoding genes of hydrogen cyanide, pyoluteorin, 2,4-diacetylphloroglucinol, pyrrolnitrin, or phenazine-1-carboxylic acid were amplified from the DNA of PCI2. On the other hand, PCI2 produced salicylic acid and jasmonic acid in Luria-Bertani medium and grew in a culture medium containing ACC as the sole nitrogen source. We observed a reduction in disease incidence from 53.33 % in the pathogen control to 30 % in tomato plants pre-inoculated with PCI2 as well as increases in shoot and root dry weights in inoculated plants, as compared to the pathogenicity control. This study suggests that inoculation of tomato seeds with P. putida PCI2 increases the resistance of plants to root rot caused by F. oxysporum and that PCI2 produces compounds that may be involved at different levels in increasing such resistance. Thus, PCI2 could represent a non-contaminating management strategy potentially applicable in vegetable crops such as tomato. PMID:27246499

  2. Isolation and characterization of actinomycete antagonists of a fungal root pathogen.

    Science.gov (United States)

    Crawford, D L; Lynch, J M; Whipps, J M; Ousley, M A

    1993-11-01

    By use of selective media, 267 actinomycete strains were isolated from four rhizosphere-associated and four non-rhizosphere-associated British soils. Organic media with low nutrient concentrations were found to be best for isolating diverse actinomycetes while avoiding contamination and overgrowth of isolation media by eubacteria and fungi. While all isolates grew well at pHs 6.5 to 8.0, a few were unable to grow at pH 6.0 and a significant number failed to grow at pH 5.5. Eighty-two selected isolates were screened for in vitro antagonism towards Pythium ultimum by use of a Difco cornmeal agar assay procedure. Five isolates were very strong antagonists of the fungus, four were strong antagonists, and ten others were weakly antagonistic. The remaining isolates showed no antagonism by this assay. Additional studies showed that several of the P. ultimum antagonists also strongly inhibited growth of other root-pathogenic fungi. Twelve isolates showing antifungal activity in the in vitro assay were also tested for their effects on the germination and short-term growth of lettuce plants in glasshouse pot studies in the absence of pathogens. None of the actinomycetes prevented seed germination, although half of the isolates retarded seed germination and outgrowth of the plants by 1 to 3 days. During 18-day growth experiments, biomass yields of some actinomycete-inoculated plants were reduced in comparison with untreated control plants, although all plants appeared healthy and well rooted. None of the actinomycetes significantly enhanced plant growth over these short-term experiments. For some, but not all, actinomycetes, some correlations between delayed seed germination and reduced 18-day plant biomass yields were seen. For others, plant biomass yields were not reduced despite an actinomycete-associated delay in seed germination and plant outgrowth. Preliminary glasshouse experiments indicated that some of the actinomycetes protect germinating lettuce seeds against

  3. The Arabidopsis Mediator Complex Subunit16 Is a Key Component of Basal Resistance against the Necrotrophic Fungal Pathogen Sclerotinia sclerotiorum.

    Science.gov (United States)

    Wang, Chenggang; Yao, Jin; Du, Xuezhu; Zhang, Yanping; Sun, Yijun; Rollins, Jeffrey A; Mou, Zhonglin

    2015-09-01

    Although Sclerotinia sclerotiorum is a devastating necrotrophic fungal plant pathogen in agriculture, the virulence mechanisms utilized by S. sclerotiorum and the host defense mechanisms against this pathogen have not been fully understood. Here, we report that the Arabidopsis (Arabidopsis thaliana) Mediator complex subunit MED16 is a key component of basal resistance against S. sclerotiorum. Mutants of MED16 are markedly more susceptible to S. sclerotiorum than mutants of 13 other Mediator subunits, and med16 has a much stronger effect on S. sclerotiorum-induced transcriptome changes compared with med8, a mutation not altering susceptibility to S. sclerotiorum. Interestingly, med16 is also more susceptible to S. sclerotiorum than coronatine-insensitive1-1 (coi1-1), which is the most susceptible mutant reported so far. Although the jasmonic acid (JA)/ethylene (ET) defense pathway marker gene PLANT DEFENSIN1.2 (PDF1.2) cannot be induced in either med16 or coi1-1, basal transcript levels of PDF1.2 in med16 are significantly lower than in coi1-1. Furthermore, ET-induced suppression of JA-activated wound responses is compromised in med16, suggesting a role for MED16 in JA-ET cross talk. Additionally, MED16 is required for the recruitment of RNA polymerase II to PDF1.2 and OCTADECANOID-RESPONSIVE ARABIDOPSIS ETHYLENE/ETHYLENE-RESPONSIVE FACTOR59 (ORA59), two target genes of both JA/ET-mediated and the transcription factor WRKY33-activated defense pathways. Finally, MED16 is physically associated with WRKY33 in yeast and in planta, and WRKY33-activated transcription of PDF1.2 and ORA59 as well as resistance to S. sclerotiorum depends on MED16. Taken together, these results indicate that MED16 regulates resistance to S. sclerotiorum by governing both JA/ET-mediated and WRKY33-activated defense signaling in Arabidopsis.

  4. Retransformation of marker-free potato for enhanced resistance against fungal pathogens by pyramiding chitinase and wasabi defensin genes.

    Science.gov (United States)

    Khan, Raham Sher; Darwish, Nader Ahmed; Khattak, Bushra; Ntui, Valentine Otang; Kong, Kynet; Shimomae, Kazuki; Nakamura, Ikuo; Mii, Masahiro

    2014-09-01

    Multi-auto-transformation vector system has been one of the strategies to produce marker-free transgenic plants without using selective chemicals and plant growth regulators and thus facilitating transgene stacking. In the study reported here, retransformation was carried out in marker-free transgenic potato CV. May Queen containing ChiC gene (isolated from Streptomyces griseus strain HUT 6037) with wasabi defensin (WD) gene (isolated from Wasabia japonica) to pyramid the two disease resistant genes. Molecular analyses of the developed shoots confirmed the existence of both the genes of interest (ChiC and WD) in transgenic plants. Co-expression of the genes was confirmed by RT-PCR, northern blot, and western blot analyses. Disease resistance assay of in vitro plants showed that the transgenic lines co-expressing both the ChiC and WD genes had higher resistance against the fungal pathogens, Fusarium oxysporum (Fusarium wilt) and Alternaria solani (early blight) compared to the non-transformed control and the transgenic lines expressing either of the ChiC or WD genes. The disease resistance potential of the transgenic plants could be increased by transgene stacking or multiple transformations. PMID:24802621

  5. Bioactivity of natural O-prenylated phenylpropenes from Illicium anisatum leaves and their derivatives against spider mites and fungal pathogens.

    Science.gov (United States)

    Koeduka, T; Sugimoto, K; Watanabe, B; Someya, N; Kawanishi, D; Gotoh, T; Ozawa, R; Takabayashi, J; Matsui, K; Hiratake, J

    2014-03-01

    A variety of volatile phenylpropenes, C6-C3 compounds are widely distributed in the plant kingdom, whereas prenylated phenylpropenes are limited to a few plant species. In this study, we analysed the volatile profiles from Illicium anisatum leaves and identified two O-prenylated phenylpropenes, 4-allyl-2-methoxy-1-[(3-methylbut-2-en-1-yl)oxy]benzene [O-dimethylallyleugenol (9)] and 5-allyl-1,3-dimethoxy-2-(3-methylbut-2-en-1-yl)oxy]benzene [O-dimethylallyl-6-methoxyeugenol (11)] as major constituents. The structure-activity relationship of a series of eugenol derivatives showed that specific phenylpropenes, including eugenol (1), isoeugenol (2) and 6-methoxyeugenol (6), with a phenolic hydroxy group had antifungal activity for a fungal pathogen, whereas guaiacol, a simple phenolic compound, and allylbenzene had no such activity. The eugenol derivatives that exhibited antifungal activity, in turn, had no significant toxicant property for mite oviposition. Interestingly, O-dimethylallyleugenol (9) in which the phenolic oxygen was masked with a dimethylallyl group exhibited a specific, potent oviposition deterrent activity for mites. The sharp contrast in structural requirements of phenylpropenes suggested distinct mechanisms underlying the two biological activities and the importance of a phenolic hydroxy group and its dimethylallylation for the structure-based design of new functional properties of phenylpropenes.

  6. Biogenic ZnO nanoparticles synthesized using L. aculeata leaf extract and their antifungal activity against plant fungal pathogens

    Indian Academy of Sciences (India)

    S Narendhran; Rajeshwari Sivaraj

    2016-02-01

    In this study, Zinc oxide (ZnO) nanoparticles were synthesized using aqueous extract of Lantana aculeata Linn. leaf and assessed their effects on antifungal activity against the plant fungal pathogens. Synthesized nanoparticles were confirmed by ultraviolet–visible spectroscopy, Fourier transform infrared spectrometer, energy-dispersive X-ray spectrometer, X-ray diffractometer, Field-emission scanning electron microscopy, high-resolution transmission electron microscopy. The antifungal activity of ZnO nanoparticles were determined using the well diffusion method. All the characterization analyses revealed that nanoparticles were highly stable and crystalline in nature. L. aculeata-mediated ZnO nanoparticles were spherical in shape with an average particle size of 12 ± 3 nm. Antifungal studies concluded that the maximum zone of inhibition was observed in Aspergillus flavus (21 ± 1.0 mm) and Fusarium oxysporum (19 ± 1.0 mm) at 100 g ml-1 concentration. These results clearly indicated the benefits of using ZnO nanoparticles synthesized using biological methods and shown to have antifungal activities and also that it can be effectively used as antifungal agent in environmental aspect of agricultural development.

  7. Genetic differentiation and recombination among geographic populations of the fungal pathogen Colletotrichum truncatum from chili peppers in China.

    Science.gov (United States)

    Diao, Yongzhao; Zhang, Can; Xu, Jianping; Lin, Dong; Liu, Li; Mtung'e, Olivo G; Liu, Xili

    2015-01-01

    Colletotrichum truncatum is an extremely important fungal pathogen. It can cause diseases both in humans and in over 460 plant species. However, little is known about its genetic diversity within and among populations. One of the major plant hosts of C. truncatum is pepper, and China is one of the main pepper-producing countries in the world. Here, we propose the hypotheses that geography has a major influence on the relationships among populations of C. truncatum in China and that infections in different populations need to be managed differently. To test these hypotheses, we obtained and analyzed 266 C. truncatum isolates from 13 regions representing the main pepper-growing areas throughout China. The analysis based on nine microsatellite markers identified high intrapopulation genetic diversity, evidence of sexual recombination, and geographic differentiation. The genetic differentiation was positively correlated with geographic distance, with the southern and northern China populations grouped in two distinct clusters. Interestingly, isolates collected from the pepper-breeding center harbored the most private alleles. The results suggest that the geographic populations of C. truncatum on peppers in China are genetically differentiated and should be managed accordingly. Our study also provides a solid foundation from which to further explore the global genetic epidemiology of C. truncatum in both plants and humans. PMID:25667606

  8. Functional properties of a cysteine proteinase from pineapple fruit with improved resistance to fungal pathogens in Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Wei; Zhang, Lu; Guo, Ning; Zhang, Xiumei; Zhang, Chen; Sun, Guangming; Xie, Jianghui

    2014-01-01

    In plant cells, many cysteine proteinases (CPs) are synthesized as precursors in the endoplasmic reticulum, and then are subject to post-translational modifications to form the active mature proteinases. They participate in various cellular and physiological functions. Here, AcCP2, a CP from pineapple fruit (Ananas comosus L.) belonging to the C1A subfamily is analyzed based on the molecular modeling and homology alignment. Transcripts of AcCP2 can be detected in the different parts of fruits (particularly outer sarcocarps), and gradually increased during fruit development until maturity. To analyze the substrate specificity of AcCP2, the recombinant protein was overexpressed and purified from Pichia pastoris. The precursor of purified AcCP2 can be processed to a 25 kDa active form after acid treatment (pH 4.3). Its optimum proteolytic activity to Bz-Phe-Val-Arg-NH-Mec is at neutral pH. In addition, the overexpression of AcCP2 gene in Arabidopsis thaliana can improve the resistance to fungal pathogen of Botrytis cinerea. These data indicate that AcCP2 is a multifunctional proteinase, and its expression could cause fruit developmental characteristics of pineapple and resistance responses in transgenic Arabidopsis plants.

  9. Functional Properties of a Cysteine Proteinase from Pineapple Fruit with Improved Resistance to Fungal Pathogens in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2014-02-01

    Full Text Available In plant cells, many cysteine proteinases (CPs are synthesized as precursors in the endoplasmic reticulum, and then are subject to post-translational modifications to form the active mature proteinases. They participate in various cellular and physiological functions. Here, AcCP2, a CP from pineapple fruit (Ananas comosus L. belonging to the C1A subfamily is analyzed based on the molecular modeling and homology alignment. Transcripts of AcCP2 can be detected in the different parts of fruits (particularly outer sarcocarps, and gradually increased during fruit development until maturity. To analyze the substrate specificity of AcCP2, the recombinant protein was overexpressed and purified from Pichia pastoris. The precursor of purified AcCP2 can be processed to a 25 kDa active form after acid treatment (pH 4.3. Its optimum proteolytic activity to Bz-Phe-Val-Arg-NH-Mec is at neutral pH. In addition, the overexpression of AcCP2 gene in Arabidopsis thaliana can improve the resistance to fungal pathogen of Botrytis cinerea. These data indicate that AcCP2 is a multifunctional proteinase, and its expression could cause fruit developmental characteristics of pineapple and resistance responses in transgenic Arabidopsis plants.

  10. Augmenting the Activity of Monoterpenoid Phenols against Fungal Pathogens Using 2-Hydroxy-4-methoxybenzaldehyde that Target Cell Wall Integrity.

    Science.gov (United States)

    Kim, Jong H; Chan, Kathleen L; Mahoney, Noreen

    2015-01-01

    Disruption of cell wall integrity system should be an effective strategy for control of fungal pathogens. To augment the cell wall disruption efficacy of monoterpenoid phenols (carvacrol, thymol), antimycotic potency of benzaldehyde derivatives that can serve as chemosensitizing agents were evaluated against strains of Saccharomyces cerevisiae wild type (WT), slt2Δ and bck1Δ (mutants of the mitogen-activated protein kinase (MAPK) and MAPK kinase kinase, respectively, in the cell wall integrity pathway). Among fourteen compounds investigated, slt2Δ and bck1Δ showed higher susceptibility to nine benzaldehydes, compared to WT. Differential antimycotic activity of screened compounds indicated "structure-activity relationship" for targeting the cell wall integrity, where 2-hydroxy-4-methoxybenzaldehyde (2H4M) exhibited the highest antimycotic potency. The efficacy of 2H4M as an effective chemosensitizer to monoterpenoid phenols (viz., 2H4M + carvacrol or thymol) was assessed in yeasts or filamentous fungi (Aspergillus, Penicillium) according to European Committee on Antimicrobial Susceptibility Testing or Clinical Laboratory Standards Institute M38-A protocols, respectively. Synergistic chemosensitization greatly lowers minimum inhibitory or fungicidal concentrations of the co-administered compounds. 2H4M also overcame the tolerance of two MAPK mutants (sakAΔ, mpkCΔ) of Aspergillus fumigatus to fludioxonil (phenylpyrrole fungicide). Collectively, 2H4M possesses chemosensitizing capability to magnify the efficacy of monoterpenoid phenols, which improves target-based (viz., cell wall disruption) antifungal intervention. PMID:26569223

  11. Radiation Sensitivity of some Food Borne Bacterial Pathogens in Animal Foods and Minced Meat

    International Nuclear Information System (INIS)

    Bacteriological examination of 100 samples of animal food stuffs (fish meal and bone and meat meal; as models of dry food materials) and 50 samples of minced meat (as a model of moist food materials) revealed the isolation of different bacterial pathogens; Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, Proteus spp., Staph. aureus and Salmonella species, in a decreasing order of occurrence. In the experiment; the dry food stuffs were sterilized in autoclave and the minced meat was sterilized by gamma irradiation at 10 kGy. The efficacy of gamma irradiation against the inoculated bacterial isolates (E coli 0157: H7, Salmonella enteritidis and Staph. aureus) in animal food stuffs and minced meat was investigated. Irradiated samples were stored at room temperature (25 degree C) for 2 weeks. The food borne pathogens used in this study showed a difference in radiation sensitivity. E. coli 0157: H7, Staphylococcus aureus and Salmonella enteritidis were eradicated at 1, 2 and 3 kGy, respectively. Also, inoculated pathogens in minced meat were more sensitive to ionizing radiation than dry animal food stuffs. It could be concluded that low doses of gamma irradiation are effective means of inactivating pathogenic bacteria. This radiation sensitivity is related to the bacterial isolates and the evaluated growth

  12. Ergothioneine Biosynthesis and Functionality in the Opportunistic Fungal Pathogen, Aspergillus fumigatus

    Science.gov (United States)

    Sheridan, Kevin J.; Lechner, Beatrix Elisabeth; Keeffe, Grainne O’; Keller, Markus A.; Werner, Ernst R.; Lindner, Herbert; Jones, Gary W.; Haas, Hubertus; Doyle, Sean

    2016-01-01

    Ergothioneine (EGT; 2-mercaptohistidine trimethylbetaine) is a trimethylated and sulphurised histidine derivative which exhibits antioxidant properties. Here we report that deletion of Aspergillus fumigatus egtA (AFUA_2G15650), which encodes a trimodular enzyme, abrogated EGT biosynthesis in this opportunistic pathogen. EGT biosynthetic deficiency in A. fumigatus significantly reduced resistance to elevated H2O2 and menadione, respectively, impaired gliotoxin production and resulted in attenuated conidiation. Quantitative proteomic analysis revealed substantial proteomic remodelling in ΔegtA compared to wild-type under both basal and ROS conditions, whereby the abundance of 290 proteins was altered. Specifically, the reciprocal differential abundance of cystathionine γ-synthase and β-lyase, respectively, influenced cystathionine availability to effect EGT biosynthesis. A combined deficiency in EGT biosynthesis and the oxidative stress response regulator Yap1, which led to extreme oxidative stress susceptibility, decreased resistance to heavy metals and production of the extracellular siderophore triacetylfusarinine C and increased accumulation of the intracellular siderophore ferricrocin. EGT dissipated H2O2 in vitro, and elevated intracellular GSH levels accompanied abrogation of EGT biosynthesis. EGT deficiency only decreased resistance to high H2O2 levels which suggests functionality as an auxiliary antioxidant, required for growth at elevated oxidative stress conditions. Combined, these data reveal new interactions between cellular redox homeostasis, secondary metabolism and metal ion homeostasis. PMID:27748436

  13. Impact of Piriformospora indica on tomato growth and on interaction with fungal and viral pathogens.

    Science.gov (United States)

    Fakhro, Ahmad; Andrade-Linares, Diana Rocío; von Bargen, Susanne; Bandte, Martina; Büttner, Carmen; Grosch, Rita; Schwarz, Dietmar; Franken, Philipp

    2010-03-01

    Piriformospora indica is a root endophytic fungus with plant-promoting properties in numerous plant species and induces resistance against root and shoot pathogens in barley, wheat, and Arabidopsis. A study over several years showed that the endophyte P. indica colonised the roots of the most consumed vegetable crop tomato. P. indica improved the growth of tomato resulting in increased biomass of leaves by up to 20%. Limitation of disease severity caused by Verticillium dahliae by more than 30% was observed on tomato plants colonised by the endophyte. Further experiments were carried out in hydroponic cultures which are commonly used for the indoor production of tomatoes in central Europe. After adaptation of inoculation techniques (inoculum density, plant stage), it was shown that P. indica influences the concentration of Pepino mosaic virus in tomato shoots. The outcome of the interaction seems to be affected by light intensity. Most importantly, the endophyte increases tomato fruit biomass in hydroponic culture concerning fresh weight (up to 100%) and dry matter content (up to 20%). Hence, P. indica represents a suitable growth promoting endophyte for tomato which can be applied in production systems of this important vegetable plant not only in soil, but also in hydroponic cultures. PMID:19789897

  14. A metabolic profiling strategy for the dissection of plant defense against fungal pathogens.

    Directory of Open Access Journals (Sweden)

    Konstantinos A Aliferis

    Full Text Available Here we present a metabolic profiling strategy employing direct infusion Orbitrap mass spectrometry (MS and gas chromatography-mass spectrometry (GC/MS for the monitoring of soybean's (Glycine max L. global metabolism regulation in response to Rhizoctonia solani infection in a time-course. Key elements in the approach are the construction of a comprehensive metabolite library for soybean, which accelerates the steps of metabolite identification and biological interpretation of results, and bioinformatics tools for the visualization and analysis of its metabolome. The study of metabolic networks revealed that infection results in the mobilization of carbohydrates, disturbance of the amino acid pool, and activation of isoflavonoid, α-linolenate, and phenylpropanoid biosynthetic pathways of the plant. Components of these pathways include phytoalexins, coumarins, flavonoids, signaling molecules, and hormones, many of which exhibit antioxidant properties and bioactivity helping the plant to counterattack the pathogen's invasion. Unraveling the biochemical mechanism operating during soybean-Rhizoctonia interaction, in addition to its significance towards the understanding of the plant's metabolism regulation under biotic stress, provides valuable insights with potential for applications in biotechnology, crop breeding, and agrochemical and food industries.

  15. Lasiolactols A and B Produced by the Grapevine Fungal Pathogen Lasiodiplodia mediterranea.

    Science.gov (United States)

    Andolfi, Anna; Basso, Sara; Giambra, Selene; Conigliaro, Gaetano; Lo Piccolo, Sandra; Alves, Artur; Burruano, Santella

    2016-04-01

    A strain of Lasiodiplodia mediterranea, a fungus associated with grapevine decline in Sicily, produced several metabolites in liquid medium. Two new dimeric γ-lactols, lasiolactols A and B (1 and 2), were characterized as (2S*,3S*,4R*,5R*,2'S*,3'S*,4'R*,5'R*)- and (2R*,3S*,4R*,5R*,2'R*,3'S*,4'R*,5'R*)-(5-(4-hydroxymethyl-3,5-dimethyl-tetrahydro-furan-2-yloxy)-2,4-dimethyl-tetrahydro-furan-3-yl]-methanols by IR, 1D- and 2D-NMR, and HR-ESI-MS. Other four metabolites were identified as botryosphaeriodiplodin, (5R)-5-hydroxylasiodiplodin, (-)-(1R,2R)-jasmonic acid, and (-)-(3S,4R,5R)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone (3 - 6, resp.). The absolute configuration (R) at hydroxylated secondary C-atom C(7) was also established for compound 3. The compounds 1 - 3, 5, and 6, tested for their phytotoxic activities to grapevine cv. Inzolia leaves at different concentrations (0.125, 0.25, 0.5, and 1 mg/ml) were phytotoxic and compound 5 showed the highest toxicity. All metabolites did not show in vitro antifungal activity against four plant pathogens. PMID:26938016

  16. Genetic recombination between human and animal parasites creates novel strains of human pathogen.

    Science.gov (United States)

    Gibson, Wendy; Peacock, Lori; Ferris, Vanessa; Fischer, Katrin; Livingstone, Jennifer; Thomas, James; Bailey, Mick

    2015-03-01

    Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr) responsible for sleeping sickness (Human African Trypanosomiasis, HAT) in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT. PMID:25816228

  17. Genetic recombination between human and animal parasites creates novel strains of human pathogen.

    Directory of Open Access Journals (Sweden)

    Wendy Gibson

    2015-03-01

    Full Text Available Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr responsible for sleeping sickness (Human African Trypanosomiasis, HAT in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.

  18. Genome‐wide gene expression dynamics of the fungal pathogen Dothistroma septosporum throughout its infection cycle of the gymnosperm host Pinus radiata

    Science.gov (United States)

    Guo, Yanan; Sim, Andre D.; Kabir, M. Shahjahan; Chettri, Pranav; Ozturk, Ibrahim K.; Hunziker, Lukas; Ganley, Rebecca J.; Cox, Murray P.

    2015-01-01

    Summary We present genome‐wide gene expression patterns as a time series through the infection cycle of the fungal pine needle blight pathogen, Dothistroma septosporum, as it invades its gymnosperm host, Pinus radiata. We determined the molecular changes at three stages of the disease cycle: epiphytic/biotrophic (early), initial necrosis (mid) and mature sporulating lesion (late). Over 1.7 billion combined plant and fungal reads were sequenced to obtain 3.2 million fungal‐specific reads, which comprised as little as 0.1% of the sample reads early in infection. This enriched dataset shows that the initial biotrophic stage is characterized by the up‐regulation of genes encoding fungal cell wall‐modifying enzymes and signalling proteins. Later necrotrophic stages show the up‐regulation of genes for secondary metabolism, putative effectors, oxidoreductases, transporters and starch degradation. This in‐depth through‐time transcriptomic study provides our first snapshot of the gene expression dynamics that characterize infection by this fungal pathogen in its gymnosperm host. PMID:25919703

  19. Mycobiome of the bat white nose syndrome affected caves and mines reveals diversity of fungi and local adaptation by the fungal pathogen Pseudogymnoascus (Geomyces destructans.

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    Tao Zhang

    Full Text Available Current investigations of bat White Nose Syndrome (WNS and the causative fungus Pseudogymnoascus (Geomyces destructans (Pd are intensely focused on the reasons for the appearance of the disease in the Northeast and its rapid spread in the US and Canada. Urgent steps are still needed for the mitigation or control of Pd to save bats. We hypothesized that a focus on fungal community would advance the understanding of ecology and ecosystem processes that are crucial in the disease transmission cycle. This study was conducted in 2010-2011 in New York and Vermont using 90 samples from four mines and two caves situated within the epicenter of WNS. We used culture-dependent (CD and culture-independent (CI methods to catalogue all fungi ('mycobiome'. CD methods included fungal isolations followed by phenotypic and molecular identifications. CI methods included amplification of DNA extracted from environmental samples with universal fungal primers followed by cloning and sequencing. CD methods yielded 675 fungal isolates and CI method yielded 594 fungal environmental nucleic acid sequences (FENAS. The core mycobiome of WNS comprised of 136 operational taxonomic units (OTUs recovered in culture and 248 OTUs recovered in clone libraries. The fungal community was diverse across the sites, although a subgroup of dominant cosmopolitan fungi was present. The frequent recovery of Pd (18% of samples positive by culture even in the presence of dominant, cosmopolitan fungal genera suggests some level of local adaptation in WNS-afflicted habitats, while the extensive distribution of Pd (48% of samples positive by real-time PCR suggests an active reservoir of the pathogen at these sites. These findings underscore the need for integrated disease control measures that target both bats and Pd in the hibernacula for the control of WNS.

  20. MYT3, a Myb-like transcription factor, affects fungal development and pathogenicity of Fusarium graminearum.

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    Yongsoo Kim

    Full Text Available We previously characterized members of the Myb protein family, MYT1 and MYT2, in Fusarium graminearum. MYT1 and MYT2 are involved in female fertility and perithecium size, respectively. To expand knowledge of Myb proteins in F. graminearum, in this study, we characterized the functions of the MYT3 gene, which encodes a putative Myb-like transcription factor containing two Myb DNA-binding domains and is conserved in the subphylum Pezizomycotina of Ascomycota. MYT3 proteins were localized in nuclei during most developmental stages, suggesting the role of MYT3 as a transcriptional regulator. Deletion of MYT3 resulted in impairment of conidiation, germination, and vegetative growth compared to the wild type, whereas complementation of MYT3 restored the wild-type phenotype. Additionally, the Δmyt3 strain grew poorly on nitrogen-limited media; however, the mutant grew robustly on minimal media supplemented with ammonium. Moreover, expression level of nitrate reductase gene in the Δmyt3 strain was decreased in comparison to the wild type and complemented strain. On flowering wheat heads, the Δmyt3 strain exhibited reduced pathogenicity, which corresponded with significant reductions in trichothecene production and transcript levels of trichothecene biosynthetic genes. When the mutant was selfed, mated as a female, or mated as a male for sexual development, perithecia were not observed on the cultures, indicating that the Δmyt3 strain lost both male and female fertility. Taken together, these results demonstrate that MYT3 is required for pathogenesis and sexual development in F. graminearum, and will provide a robust foundation to establish the regulatory networks for all Myb-like proteins in F. graminearum.

  1. Methodology of the biological risk classification of animal pathogens in Belgium.

    Science.gov (United States)

    Van Vaerenbergh, B; Koenen, F; Pauwels, K; Quanten, K; Boyen, F; Declercq, K; Desmecht, D; Thiry, J; Herman, P

    2010-12-01

    Since many micro-organisms are a biological hazard, they have been categorised into risk groups by many countries and organisations and classification lists have been developed. Current classification systems rely on criteria defined by the World Health Organization, which cover the severity of the disease the micro-organism might cause, its ability to spread and the availability of prophylaxis or efficient treatment. Animal pathogens are classified according to the definitions of the World Organisation for Animal Health, which also consider economic aspects of disease. In Europe, classification is often directly linked to containment measures. The Belgian classification system, however, only considers the inherent characteristics of the micro-organism, not its use, making the risk classification independent of containment measures. A common classification list for human and animal pathogens has been developed in Belgium using as comprehensive an approach as possible. The evolution of scientific knowledge will demand regular updating of classification lists. This paper describes the Belgian risk classification system and the methodology that was used for its peer-reviewed revision (with a focus on animal pathogens).

  2. DNA Extraction Method Affects the Detection of a Fungal Pathogen in Formalin-Fixed Specimens Using qPCR.

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    Andrea J Adams

    Full Text Available Museum collections provide indispensable repositories for obtaining information about the historical presence of disease in wildlife populations. The pathogenic amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd has played a significant role in global amphibian declines, and examining preserved specimens for Bd can improve our understanding of its emergence and spread. Quantitative PCR (qPCR enables Bd detection with minimal disturbance to amphibian skin and is significantly more sensitive to detecting Bd than histology; therefore, developing effective qPCR methodologies for detecting Bd DNA in formalin-fixed specimens can provide an efficient and effective approach to examining historical Bd emergence and prevalence. Techniques for detecting Bd in museum specimens have not been evaluated for their effectiveness in control specimens that mimic the conditions of animals most likely to be encountered in museums, including those with low pathogen loads. We used American bullfrogs (Lithobates catesbeianus of known infection status to evaluate the success of qPCR to detect Bd in formalin-fixed specimens after three years of ethanol storage. Our objectives were to compare the most commonly used DNA extraction method for Bd (PrepMan, PM to Macherey-Nagel DNA FFPE (MN, test optimizations for Bd detection with PM, and provide recommendations for maximizing Bd detection. We found that successful detection is relatively high (80-90% when Bd loads before formalin fixation are high, regardless of the extraction method used; however, at lower infection levels, detection probabilities were significantly reduced. The MN DNA extraction method increased Bd detection by as much as 50% at moderate infection levels. Our results indicate that, for animals characterized by lower pathogen loads (i.e., those most commonly encountered in museum collections, current methods may underestimate the proportion of Bd-infected amphibians. Those extracting DNA from

  3. DNA Extraction Method Affects the Detection of a Fungal Pathogen in Formalin-Fixed Specimens Using qPCR.

    Science.gov (United States)

    Adams, Andrea J; LaBonte, John P; Ball, Morgan L; Richards-Hrdlicka, Kathryn L; Toothman, Mary H; Briggs, Cheryl J

    2015-01-01

    Museum collections provide indispensable repositories for obtaining information about the historical presence of disease in wildlife populations. The pathogenic amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has played a significant role in global amphibian declines, and examining preserved specimens for Bd can improve our understanding of its emergence and spread. Quantitative PCR (qPCR) enables Bd detection with minimal disturbance to amphibian skin and is significantly more sensitive to detecting Bd than histology; therefore, developing effective qPCR methodologies for detecting Bd DNA in formalin-fixed specimens can provide an efficient and effective approach to examining historical Bd emergence and prevalence. Techniques for detecting Bd in museum specimens have not been evaluated for their effectiveness in control specimens that mimic the conditions of animals most likely to be encountered in museums, including those with low pathogen loads. We used American bullfrogs (Lithobates catesbeianus) of known infection status to evaluate the success of qPCR to detect Bd in formalin-fixed specimens after three years of ethanol storage. Our objectives were to compare the most commonly used DNA extraction method for Bd (PrepMan, PM) to Macherey-Nagel DNA FFPE (MN), test optimizations for Bd detection with PM, and provide recommendations for maximizing Bd detection. We found that successful detection is relatively high (80-90%) when Bd loads before formalin fixation are high, regardless of the extraction method used; however, at lower infection levels, detection probabilities were significantly reduced. The MN DNA extraction method increased Bd detection by as much as 50% at moderate infection levels. Our results indicate that, for animals characterized by lower pathogen loads (i.e., those most commonly encountered in museum collections), current methods may underestimate the proportion of Bd-infected amphibians. Those extracting DNA from archived museum

  4. Are bacterial volatile compounds poisonous odors to a fungal pathogen Botrytis cinerea, alarm signals to Arabidopsis seedlings for eliciting induced resistance, or both?

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    Choong-Min eRyu

    2016-02-01

    Full Text Available Biological control (biocontrol agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR. Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs are determinants for eliciting plant ISR. Emerging data suggest that bacterial VOCs also can directly inhibit fungal and plant growth. The aim of the current study was to differentiate direct and indirect mechanisms of bacterial VOC effects against Botrytis cinerea infection of Arabidopsis. Volatile emissions from Bacillus subtilis GB03 successfully protected Arabidopsis seedlings against B. cinerea. First, we investigated the direct effects of bacterial VOCs on symptom development and different phenological stages of B. cinerea including spore germination, mycelial attachment to the leaf surface, mycelial growth, and sporulation in vitro and in planta. Volatile emissions inhibited hyphal growth in a dose-dependent manner in vitro, and interfered with fungal attachment on the hydrophobic leaf surface. Second, the optimized bacterial concentration that did not directly inhibit fungal growth successfully protected Arabidopsis from fungal infection, which indicates that bacterial VOC-elicited plant ISR has a more important role in biocontrol than direct inhibition of fungal growth on Arabidopsis. We performed qRT-PCR to investigate the priming of the defense-related genes PR1, PDF1.2, and ChiB at 0, 12, 24, and 36 hours post-infection and 14 days after the start of plant exposure to bacterial VOCs. The results indicate that bacterial VOCs potentiate expression of PR1 and PDF1.2 but not ChiB, which stimulates SA- and JA-dependent signaling pathways in plant ISR and protects plants against pathogen

  5. Are Bacterial Volatile Compounds Poisonous Odors to a Fungal Pathogen Botrytis cinerea, Alarm Signals to Arabidopsis Seedlings for Eliciting Induced Resistance, or Both?

    Science.gov (United States)

    Sharifi, Rouhallah; Ryu, Choong-Min

    2016-01-01

    Biological control (biocontrol) agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR). Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs) are determinants for eliciting plant ISR. Emerging data suggest that bacterial VOCs also can directly inhibit fungal and plant growth. The aim of the current study was to differentiate direct and indirect mechanisms of bacterial VOC effects against Botrytis cinerea infection of Arabidopsis. Volatile emissions from Bacillus subtilis GB03 successfully protected Arabidopsis seedlings against B. cinerea. First, we investigated the direct effects of bacterial VOCs on symptom development and different phenological stages of B. cinerea including spore germination, mycelial attachment to the leaf surface, mycelial growth, and sporulation in vitro and in planta. Volatile emissions inhibited hyphal growth in a dose-dependent manner in vitro, and interfered with fungal attachment on the hydrophobic leaf surface. Second, the optimized bacterial concentration that did not directly inhibit fungal growth successfully protected Arabidopsis from fungal infection, which indicates that bacterial VOC-elicited plant ISR has a more important role in biocontrol than direct inhibition of fungal growth on Arabidopsis. We performed qRT-PCR to investigate the priming of the defense-related genes PR1, PDF1.2, and ChiB at 0, 12, 24, and 36 h post-infection and 14 days after the start of plant exposure to bacterial VOCs. The results indicate that bacterial VOCs potentiate expression of PR1 and PDF1.2 but not ChiB, which stimulates SA- and JA-dependent signaling pathways in plant ISR and protects plants against pathogen colonization. This study

  6. Photobacterium damselae subsp. damselae, a bacterium pathogenic for marine animals and humans

    OpenAIRE

    Amable J. Rivas; Lemos, Manuel L.; Osorio, Carlos R.

    2013-01-01

    Photobacterium damselae subsp. damselae (formerly Vibrio damsela) is a pathogen of a variety of marine animals including fish, crustaceans, molluscs, and cetaceans. In humans, it can cause opportunistic infections that may evolve into necrotizing fasciitis with fatal outcome. Although the genetic basis of virulence in this bacterium is not completely elucidated, recent findings demonstrate that the phospholipase-D Dly (damselysin) and the pore-forming toxins HlyApl and HlyAch play a main role...

  7. Animal Models to Assess the Pathogenicity of Genetically Modified Microorganisms for Humans

    OpenAIRE

    Hentges, D J; Petschow, B W; Dougherty, S. H.; Marsh, W. W.

    2011-01-01

    Two animal models are proposed to assess the colonising capacities and other virulence factors of genetically modified enteric microorganisms for humans. One is the streptomycin treated mouse which is exceedingly susceptible to colonisation with enteric pathogens. The other is the human intestinal microbiota associated mouse which, in ecological studies, responded in a manner similar to human infants to variations in diet. The latter model is recommended because of differences between human a...

  8. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens.

    Science.gov (United States)

    López Hernández, Yamilé; Yero, Daniel; Pinos-Rodríguez, Juan M; Gibert, Isidre

    2015-01-01

    Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host-pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host-pathogen interactions. PMID:25699030

  9. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Yamilé eLópez Hernández

    2015-02-01

    Full Text Available Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as a valuate tools to explore host-pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio, and non-vertebrate insects and nematodes (e.g. Caenorhabditis elegans in the study of diverse infectious agents that affect humans. Here we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favour of the use of these alternative animal models of infection to reveal the molecular signatures of host-pathogen interactions.

  10. A few shared up-regulated genes may influence conidia to yeast transformation in dimorphic fungal pathogens.

    Science.gov (United States)

    Kirkland, Theo N

    2016-08-01

    The small number of fungi that commonly cause disease in normal people share the capacity to grow as mycelia in the soil at 25°C and as yeast (or spherules) in mammals at 37°C. This remarkable conversion has long been a topic of interest in medical mycology. The conidia to yeast conversion has been studied by transcription profiling in several fungal species, including Histoplasma capsulatum, Paracoccidioides brasiliensis, Coccidioides spp., Blastomyces dermatitidis, and Talaromyces marneffei One limitation of transcriptional profiling is determining which genes are involved in the process of conversion to yeast as opposed to a result of conversion to yeast. If there are genes that are up-regulated in the yeast phase of more than one dimorphic, pathogenic fungus they might be required for conversion to yeast (or spherules). To address this issue, 24 up-regulated genes common to Coccidioides spp spherules and H. capsulatum yeasts were identified. Four homologs of these genes were also found in P. brasiliensis, B. dermatitidis or T. marneffei genes that were up-regulated in yeast. 4-hydroxyphenylpurvate dioxygenase, a gene involved in tyrosine metabolism and melanin synthesis that has been shown to be required for yeast conversion, is conserved and up-regulated in yeast in all five species. Another up-regulated gene that is conserved in all five species is a MFS sugar porter. These results suggest that a minority of up-regulated yeast (or spherule) genes are conserved across species and raises the possibility that conserved up-regulated genes may be of special interest for differentiation of mycelium into yeast. PMID:27118798

  11. Impact of the lectin chaperone calnexin on the stress response, virulence and proteolytic secretome of the fungal pathogen Aspergillus fumigatus.

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    Margaret V Powers-Fletcher

    Full Text Available Calnexin is a membrane-bound lectin chaperone in the endoplasmic reticulum (ER that is part of a quality control system that promotes the accurate folding of glycoproteins entering the secretory pathway. We have previously shown that ER homeostasis is important for virulence of the human fungal pathogen Aspergillus fumigatus, but the contribution of calnexin has not been explored. Here, we determined the extent to which A. fumigatus relies on calnexin for growth under conditions of environmental stress and for virulence. The calnexin gene, clxA, was deleted from A. fumigatus and complemented by reconstitution with the wild type gene. Loss of clxA altered the proteolytic secretome of the fungus, but had no impact on growth rates in either minimal or complex media at 37°C. However, the ΔclxA mutant was growth impaired at temperatures above 42°C and was hypersensitive to acute ER stress caused by the reducing agent dithiothreitol. In contrast to wild type A. fumigatus, ΔclxA hyphae were unable to grow when transferred to starvation medium. In addition, depleting the medium of cations by chelation prevented ΔclxA from sustaining polarized hyphal growth, resulting in blunted hyphae with irregular morphology. Despite these abnormal stress responses, the ΔclxA mutant remained virulent in two immunologically distinct models of invasive aspergillosis. These findings demonstrate that calnexin functions are needed for growth under conditions of thermal, ER and nutrient stress, but are dispensable for surviving the stresses encountered in the host environment.

  12. Ozone episodes in Southern Lower Saxony (FRG) and their impact on the susceptibility of cereals to fungal pathogens.

    Science.gov (United States)

    von Tiedemann, A; Ostländer, P; Firsching, K H; Fehrmann, H

    1990-01-01

    Spring wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.) plants were exposed to simulated ozone (O(3)) episodes (7 h day(-1) for 7 days) at maximum concentrations of 120, 180 and 240 microg m(-3) O(3), in comparison to a charcoal-filtered air control. Fumigations were conducted in four closed chambers placed in a climate room. Exposures took place prior to inoculation of the plants with six different facultative leaf pathogens. On wheat, significant enhancement of leaf attack by Septoria nodorum Berk. and S. tritici Rob. ex Desm. appeared, particularly on the older leaves and at the highest level of O(3). The same was true for Gerlachia nivalis W. Gams et E. Müll/Fusarium culmorum (W.F.Sm.) Sacc. on wheat and net blotch (Drechslera teres (Sacc.) Shoem.) or G. nivalis leaf spots on barley. Disease development was promoted both on leaves with and without visible injury following exposure to O(3). Sporulation of the two Septoria species increased at 120 and 180 microg m(-3) O(3); however, it was reduced to the level of the control, if 240 microg m(-3) were applied. No significant effects of predisposition were observed with Bipolaris sorokiniana (Sacc.) Shoem. (syn. Helminthosporium sativum Pamm., King et Bakke), the causal agent of spot blotch, neither on wheat nor on barley. Doses and peak concentrations applied in the experiments were in good agreement with measurements of ambient ozone in Southern Lower Saxony, FRG. Six years' ozone data (1984-1989) revealed the annual occurrence of between 3 and 11 ozone episodes with potentially harmful effects on cereals (three or more consecutive 'ozone days' with 8-h means above 80 microg m(-3)). The frequency of ozone episodes followed by weather periods favourable for infections by facultative pathogens was higher in years with low O(3) pollution than in ozone-rich years, and varied between one and five cases per season. The number of ozone days during the main growing season of cereals (1 April until 31

  13. Evaluating the risk of pathogen transmission from wild animals to domestic pigs in Australia.

    Science.gov (United States)

    Pearson, Hayley E; Toribio, Jenny-Ann L M L; Lapidge, Steven J; Hernández-Jover, Marta

    2016-01-01

    Wild animals contribute to endemic infection in livestock as well as the introduction, reintroduction and maintenance of pathogens. The source of introduction of endemic diseases to a piggery is often unknown and the extent of wildlife contribution to such local spread is largely unexplored. The aim of the current study was to quantitatively assess the probability of domestic pigs being exposed to different pathogens from wild animals commonly found around commercial piggeries in Australia. Specifically, this study aims to quantify the probability of exposure to the pathogens Escherichia coli, Salmonella spp. and Campylobacter spp. from European starlings (Sturnus vulgarus); Brachyspira hyodysenteriae, Lawsonia intracellularis and Salmonella spp. from rats (Rattus rattus and Rattus norvegicus); and Mycoplasma hyopneumoniae, Leptospira spp., Brucella suis and L. intracellularis from feral pigs (Sus scrofa). Exposure assessments, using scenario trees and Monte Carlo stochastic simulation modelling, were conducted to identify potential pathways of introduction and calculate the probabilities of these pathways occurring. Input parameters were estimated from a national postal survey of commercial pork producers and from disease detection studies conducted for European starlings, rats and feral pigs in close proximity to commercial piggeries in Australia. Based on the results of the exposure assessments, rats presented the highest probability of exposure of pathogens to domestic pigs at any point in time, and L. intracellularis (median 0.13, 5% and 95%, 0.05-0.23) and B. hyodysenteriae (median 0.10, 0.05-0.19) were the most likely pathogens to be transmitted. Regarding European starlings, the median probability of exposure of domestic pigs to pathogenic E. coli at any point in time was estimated to be 0.03 (0.02-0.04). The highest probability of domestic pig exposure to feral pig pathogens at any point in time was found to be for M. hyopneumoniae (median 0.013, 0

  14. Cladophialophora bantiana as an Emerging Pathogen in Animals: Case Report of Equine Endometritis and Review of the Literature.

    Science.gov (United States)

    Rantala, Merja; Attia, Stella; Koukila-Kähkölä, Pirkko; de Hoog, Sybren; Anttila, Marjukka; Katila, Terttu

    2015-09-01

    We present an unusual equine endometritis case associated with Cladophialophora bantiana in a 15-year-old mare. The mare displayed infertility and uterine fluid accumulation with numerous black, hairy granules. Microscopically, the fluid revealed numerous septate, dark fungal hyphae and conidia in chains. Culture yielded C. bantiana (CBS 138271); the species was confirmed by internal transcribed spacer (ITS) sequencing. Treatment was unsuccessful. C. bantiana causes cerebral phaeohyphomycosis in humans, while animal cases are rare. Animal cases are reviewed. PMID:26085616

  15. Cytotoxic and pathogenic properties of Klebsiella oxytoca isolated from laboratory animals.

    Directory of Open Access Journals (Sweden)

    Alison Darby

    Full Text Available Klebsiella oxytoca is an opportunistic pathogen implicated in various clinical diseases in animals and humans. Studies suggest that in humans K. oxytoca exerts its pathogenicity in part through a cytotoxin. However, cytotoxin production in animal isolates of K. oxytoca and its pathogenic properties have not been characterized. Furthermore, neither the identity of the toxin nor a complete repertoire of genes involved in K. oxytoca pathogenesis have been fully elucidated. Here, we showed that several animal isolates of K. oxytoca, including the clinical isolates, produced secreted products in bacterial culture supernatant that display cytotoxicity on HEp-2 and HeLa cells, indicating the ability to produce cytotoxin. Cytotoxin production appears to be regulated by the environment, and soy based product was found to have a strong toxin induction property. The toxin was identified, by liquid chromatography-mass spectrometry and NMR spectroscopy, as low molecular weight heat labile benzodiazepine, tilivalline, previously shown to cause cytotoxicity in several cell lines, including mouse L1210 leukemic cells. Genome sequencing and analyses of a cytotoxin positive K. oxytoca strain isolated from an abscess of a mouse, identified genes previously shown to promote pathogenesis in other enteric bacterial pathogens including ecotin, several genes encoding for type IV and type VI secretion systems, and proteins that show sequence similarity to known bacterial toxins including cholera toxin. To our knowledge, these results demonstrate for the first time, that animal isolates of K. oxytoca, produces a cytotoxin, and that cytotoxin production is under strict environmental regulation. We also confirmed tilivalline as the cytotoxin present in animal K. oxytoca strains. These findings, along with the discovery of a repertoire of genes with virulence potential, provide important insights into the pathogenesis of K. oxytoca. As a novel diagnostic tool, tilivalline

  16. STUDY OF MICROBIAL DIVERSITY OF FUNGAL COMMUNITIES FROM RHIZOSPHERE AND PHYLOSPHERE OF STRAWBERRY TREATED WITH CHEMICAL AND BIOLOGICAL AGENTS FOR THE CONTROL OF PATHOGENS

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    Gabi-Mirela Matei

    2011-12-01

    Full Text Available The negative impact of long term utilization of pesticides on yields quality, as well as on the human health made scientific community to seek new ways, less expensive and environmental friendly for protecting cultivated plants against pathogens. Biological control agents of microbial origin represented by living selected strains or their metabolites are more and more frequently utilized for protecting horticultural plants intensely consumed by European population, such as strawberry. A green house experiment was designed to compare the structure of rhizospheric and phylospheric microflora of strawberry cv. Senga Sengana, sensible to Botrytis cinerea (the agent of grey mould treated with systemic and contact fungicides, as well as with four biological control preparations of microbial origin administrated on plant leaves or in the soil. The structure of fungal communities in rhizosphere and phylosphere of strawberry cv. Senga Sengana varied as a function of the nature of control agent and the method of administration. Non significant influence on soil fungal community diversity index and species number was registered after the treatment with chemical and biological control agents, but significant increments were induced in time by control agents as compared with both non-treated control and chemical pesticides. Fungal community structure from strawberry leaves was not significantly influenced by chemical and biological control agents. The most favourable influence on fungal communities registered for bio-control agents E1 and E2 due to

  17. Genome-wide profiling of DNA methylation provides insights into epigenetic regulation of fungal development in a plant pathogenic fungus, Magnaporthe oryzae.

    Science.gov (United States)

    Jeon, Junhyun; Choi, Jaeyoung; Lee, Gir-Won; Park, Sook-Young; Huh, Aram; Dean, Ralph A; Lee, Yong-Hwan

    2015-02-24

    DNA methylation is an important epigenetic modification that regulates development of plants and mammals. To investigate the roles of DNA methylation in fungal development, we profiled genome-wide methylation patterns at single-nucleotide resolution during vegetative growth, asexual reproduction, and infection-related morphogenesis in a model plant pathogenic fungus, Magnaporthe oryzae. We found that DNA methylation occurs in and around genes as well as transposable elements and undergoes global reprogramming during fungal development. Such reprogramming of DNA methylation suggests that it may have acquired new roles other than controlling the proliferation of TEs. Genetic analysis of DNA methyltransferase deletion mutants also indicated that proper reprogramming in methylomes is required for asexual reproduction in the fungus. Furthermore, RNA-seq analysis showed that DNA methylation is associated with transcriptional silencing of transposable elements and transcript abundance of genes in context-dependent manner, reinforcing the role of DNA methylation as a genome defense mechanism. This comprehensive approach suggests that DNA methylation in fungi can be a dynamic epigenetic entity contributing to fungal development and genome defense. Furthermore, our DNA methylomes provide a foundation for future studies exploring this key epigenetic modification in fungal development and pathogenesis.

  18. Agrobacterium-mediated transformation of tomato with rolB gene results in enhancement of fruit quality and foliar resistance against fungal pathogens.

    Science.gov (United States)

    Arshad, Waheed; Haq, Ihsan-ul-; Waheed, Mohammad Tahir; Mysore, Kirankumar S; Mirza, Bushra

    2014-01-01

    Tomato (Solanum lycopersicum L.) is the second most important cultivated crop next to potato, worldwide. Tomato serves as an important source of antioxidants in human diet. Alternaria solani and Fusarium oxysporum cause early blight and vascular wilt of tomato, respectively, resulting in severe crop losses. The foremost objective of the present study was to generate transgenic tomato plants with rolB gene and evaluate its effect on plant morphology, nutritional contents, yield and resistance against fungal infection. Tomato cv. Rio Grande was transformed via Agrobacterium tumefaciens harbouring rolB gene of Agrobacterium rhizogenes. rolB. Biochemical analyses showed considerable improvement in nutritional quality of transgenic tomato fruits as indicated by 62% increase in lycopene content, 225% in ascorbic acid content, 58% in total phenolics and 26% in free radical scavenging activity. Furthermore, rolB gene significantly improved the defence response of leaves of transgenic plants against two pathogenic fungal strains A. solani and F. oxysporum. Contrarily, transformed plants exhibited altered morphology and reduced fruit yield. In conclusion, rolB gene from A. rhizogenes can be used to generate transgenic tomato with increased nutritional contents of fruits as well as improved foliar tolerance against fungal pathogens. PMID:24817272

  19. Agrobacterium-mediated transformation of tomato with rolB gene results in enhancement of fruit quality and foliar resistance against fungal pathogens.

    Directory of Open Access Journals (Sweden)

    Waheed Arshad

    Full Text Available Tomato (Solanum lycopersicum L. is the second most important cultivated crop next to potato, worldwide. Tomato serves as an important source of antioxidants in human diet. Alternaria solani and Fusarium oxysporum cause early blight and vascular wilt of tomato, respectively, resulting in severe crop losses. The foremost objective of the present study was to generate transgenic tomato plants with rolB gene and evaluate its effect on plant morphology, nutritional contents, yield and resistance against fungal infection. Tomato cv. Rio Grande was transformed via Agrobacterium tumefaciens harbouring rolB gene of Agrobacterium rhizogenes. rolB. Biochemical analyses showed considerable improvement in nutritional quality of transgenic tomato fruits as indicated by 62% increase in lycopene content, 225% in ascorbic acid content, 58% in total phenolics and 26% in free radical scavenging activity. Furthermore, rolB gene significantly improved the defence response of leaves of transgenic plants against two pathogenic fungal strains A. solani and F. oxysporum. Contrarily, transformed plants exhibited altered morphology and reduced fruit yield. In conclusion, rolB gene from A. rhizogenes can be used to generate transgenic tomato with increased nutritional contents of fruits as well as improved foliar tolerance against fungal pathogens.

  20. Agrobacterium-mediated transformation of tomato with rolB gene results in enhancement of fruit quality and foliar resistance against fungal pathogens.

    Science.gov (United States)

    Arshad, Waheed; Haq, Ihsan-ul-; Waheed, Mohammad Tahir; Mysore, Kirankumar S; Mirza, Bushra

    2014-01-01

    Tomato (Solanum lycopersicum L.) is the second most important cultivated crop next to potato, worldwide. Tomato serves as an important source of antioxidants in human diet. Alternaria solani and Fusarium oxysporum cause early blight and vascular wilt of tomato, respectively, resulting in severe crop losses. The foremost objective of the present study was to generate transgenic tomato plants with rolB gene and evaluate its effect on plant morphology, nutritional contents, yield and resistance against fungal infection. Tomato cv. Rio Grande was transformed via Agrobacterium tumefaciens harbouring rolB gene of Agrobacterium rhizogenes. rolB. Biochemical analyses showed considerable improvement in nutritional quality of transgenic tomato fruits as indicated by 62% increase in lycopene content, 225% in ascorbic acid content, 58% in total phenolics and 26% in free radical scavenging activity. Furthermore, rolB gene significantly improved the defence response of leaves of transgenic plants against two pathogenic fungal strains A. solani and F. oxysporum. Contrarily, transformed plants exhibited altered morphology and reduced fruit yield. In conclusion, rolB gene from A. rhizogenes can be used to generate transgenic tomato with increased nutritional contents of fruits as well as improved foliar tolerance against fungal pathogens.

  1. Comparison and Evaluation of Three Animal Models for Studying the Pathogenicity of Staphylococcus epidermidis

    Institute of Scientific and Technical Information of China (English)

    李华林; 王勇翔; 陈喆; 齐玲; 瞿涤; 闻玉梅

    2003-01-01

    In order to compare and evaluate three animal models for studying the pathogenicity of Staphylococcus epidermidis strains, three experimental animal models, namely, murine intra-venous LD50, mouse foreign body infection and rat central venous catheter (CVC) infection models were used to assess the relative virulence of two S. epidermidis strains, ATCC 12228 and 97-337. The results from three animal models were comparable, indicating S. epidermidis 97-337 was more virulent than strain ATCC 12228. The rat CVC infection model best mimicked the conditions of clinical patients with intmvenonscatheters, and more information could be obtained from this model. We conclude that different in vivo models serve for dif-ferent purposes, and the rat CVC infection model is most suitable for studying specific characteristics of catheter related infections caused by S. epidermidis stratus.

  2. Emerging Genomic and Proteomic Evidence on Relationships Among the Animal, Plant and Fungal Kingdoms

    Institute of Scientific and Technical Information of China (English)

    John W. Stiller

    2004-01-01

    Sequence-based molecular phylogenies have provided new models of early eukaryotic evolution. This includes the widely accepted hypothesis that animals are related most closely to fungi, and that the two should be grouped together as the Opisthokonta. Although most published phylogenies have supported an opisthokont relationship, a number of genes contain a tree-building signal that clusters animal and green plant sequences, to the exclusion of fungi. The alternative tree-building signal is especially intriguing in light of emerging data from genomic and proteomic studies that indicate striking and potentially synapomorphic similarities between plants and animals. This paper reviews these new lines of evidence, which have yet to be incorporated into models of broad scale eukaryotic evolution.

  3. PKC signaling regulates drug resistance of the fungal pathogen Candida albicans via circuitry comprised of Mkc1, calcineurin, and Hsp90.

    Directory of Open Access Journals (Sweden)

    Shantelle L LaFayette

    Full Text Available Fungal pathogens exploit diverse mechanisms to survive exposure to antifungal drugs. This poses concern given the limited number of clinically useful antifungals and the growing population of immunocompromised individuals vulnerable to life-threatening fungal infection. To identify molecules that abrogate resistance to the most widely deployed class of antifungals, the azoles, we conducted a screen of 1,280 pharmacologically active compounds. Three out of seven hits that abolished azole resistance of a resistant mutant of the model yeast Saccharomyces cerevisiae and a clinical isolate of the leading human fungal pathogen Candida albicans were inhibitors of protein kinase C (PKC, which regulates cell wall integrity during growth, morphogenesis, and response to cell wall stress. Pharmacological or genetic impairment of Pkc1 conferred hypersensitivity to multiple drugs that target synthesis of the key cell membrane sterol ergosterol, including azoles, allylamines, and morpholines. Pkc1 enabled survival of cell membrane stress at least in part via the mitogen activated protein kinase (MAPK cascade in both species, though through distinct downstream effectors. Strikingly, inhibition of Pkc1 phenocopied inhibition of the molecular chaperone Hsp90 or its client protein calcineurin. PKC signaling was required for calcineurin activation in response to drug exposure in S. cerevisiae. In contrast, Pkc1 and calcineurin independently regulate drug resistance via a common target in C. albicans. We identified an additional level of regulatory control in the C. albicans circuitry linking PKC signaling, Hsp90, and calcineurin as genetic reduction of Hsp90 led to depletion of the terminal MAPK, Mkc1. Deletion of C. albicans PKC1 rendered fungistatic ergosterol biosynthesis inhibitors fungicidal and attenuated virulence in a murine model of systemic candidiasis. This work establishes a new role for PKC signaling in drug resistance, novel circuitry through which

  4. Arabidopsis Elongator subunit 2 positively contributes to resistance to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola.

    Science.gov (United States)

    Wang, Chenggang; Ding, Yezhang; Yao, Jin; Zhang, Yanping; Sun, Yijun; Colee, James; Mou, Zhonglin

    2015-09-01

    The evolutionarily conserved Elongator complex functions in diverse biological processes including salicylic acid-mediated immune response. However, how Elongator functions in jasmonic acid (JA)/ethylene (ET)-mediated defense is unknown. Here, we show that Elongator is required for full induction of the JA/ET defense pathway marker gene PLANT DEFENSIN1.2 (PDF1.2) and for resistance to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola. A loss-of-function mutation in the Arabidopsis Elongator subunit 2 (ELP2) alters B. cinerea-induced transcriptome reprogramming. Interestingly, in elp2, expression of WRKY33, OCTADECANOID-RESPONSIVE ARABIDOPSIS AP2/ERF59 (ORA59), and PDF1.2 is inhibited, whereas transcription of MYC2 and its target genes is enhanced. However, overexpression of WRKY33 or ORA59 and mutation of MYC2 fail to restore PDF1.2 expression and B. cinerea resistance in elp2, suggesting that ELP2 is required for induction of not only WRKY33 and ORA59 but also PDF1.2. Moreover, elp2 is as susceptible as coronatine-insensitive1 (coi1) and ethylene-insensitive2 (ein2) to B. cinerea, indicating that ELP2 is an important player in B. cinerea resistance. Further analysis of the lesion sizes on the double mutants elp2 coi1 and elp2 ein2 and the corresponding single mutants revealed that the function of ELP2 overlaps with COI1 and is additive to EIN2 for B. cinerea resistance. Finally, basal histone acetylation levels in the coding regions of WRKY33, ORA59, and PDF1.2 are reduced in elp2 and a functional ELP2-GFP fusion protein binds to the chromatin of these genes, suggesting that constitutive ELP2-mediated histone acetylation may be required for full activation of the WRKY33/ORA59/PDF1.2 transcriptional cascade.

  5. Quantitative polymerase chain reaction (PCR) for detection of aquatic animal pathogens in a diagnostic laboratory setting

    Science.gov (United States)

    Purcell, Maureen K.; Getchell, Rodman G.; McClure, Carol A.; Weber, S.E.; Garver, Kyle A.

    2011-01-01

    Real-time, or quantitative, polymerase chain reaction (qPCR) is quickly supplanting other molecular methods for detecting the nucleic acids of human and other animal pathogens owing to the speed and robustness of the technology. As the aquatic animal health community moves toward implementing national diagnostic testing schemes, it will need to evaluate how qPCR technology should be employed. This review outlines the basic principles of qPCR technology, considerations for assay development, standards and controls, assay performance, diagnostic validation, implementation in the diagnostic laboratory, and quality assurance and control measures. These factors are fundamental for ensuring the validity of qPCR assay results obtained in the diagnostic laboratory setting.

  6. Scope for using plant viruses to present epitopes from animal pathogens.

    Science.gov (United States)

    Porta; Lomonossoff

    1998-01-01

    Epitope presentation to the immune system for vaccination purposes can be achieved either via an inactivated or attenuated form of a pathogen or via its isolated antigenic sequences. When free, these peptides can adopt a variety of conformations, most of which will not exist in their native environment. Conjugation to carrier proteins restricts mobility of the peptides and increases their immunogenicity. A high local concentration of epitopes boosts the immune response further and can be generated by the use of self-aggregating carriers, such as the capsid proteins of viruses. In this regard plant viruses have in recent years started to make an impact as safer alternatives to the use of bacterial and attenuated animal viruses: the latter both require propagation in costly cell-culture systems where they can undergo reversion towards a virulent form and/or become contaminated by other pathogens. Plant virus-based vectors can be multiplied cheaply and to high yields (exceeding 1 mg/g plant tissue) in host plants. Both helical (tobacco mosaic virus, potato virus X, alfalfa mosaic virus) and icosahedral (cowpea mosaic virus, tomato bushy stunt virus) particles have been used to express a number of animal B-cell epitopes, whose immunogenic properties have been explored to varying degrees. Copyright 1998 John Wiley & Sons, Ltd. PMID:10398492

  7. IRIDOID GLYCOSIDES FROM LINARIA GENISTIFOLIA (L. MILL. IN BIOLOGICAL CONTROL OF SOIL-BORNE FUNGAL PATHOGENS OF WHEAT AND SOME STRUCTURE CONSIDERATIONS

    Directory of Open Access Journals (Sweden)

    Natalia Mashcenko

    2015-06-01

    Full Text Available Biological activity of the iridoid glycosides extract from Linaria genistifolia (L. Mill. has been investigated, namely its influence on the resistance of the winter wheat Odesschi 51 plant to the caused by the Fusarium oxysporum and Helminthosporium avenae pathogenic fungi root rot. Our results indicate that summary iridoid glycosides from this plant, containing four major known compounds: 5-O-allosylantirrinoside, antirrinoside, linarioside and 6-β-hidroxiantirride, can be successfully employed in biological control of the afore-mentioned wheat pathogens: it stimulates wheat grains germination and embryonic root growth in conditions of fungal infection. 1H and 13C NMR characteristics of 5-O-allosylantirrinoside in Py-d5 are for the first time presented. Structures of two conformers of 5-O-allosylantirrinoside in D2O and Py-d5 solutions are proposed, based on the experimental NMR evidence and molecular modelling studies.

  8. Polyphenols Variation in Fruits of the Susceptible Strawberry Cultivar Alba during Ripening and upon Fungal Pathogen Interaction and Possible Involvement in Unripe Fruit Tolerance.

    Science.gov (United States)

    Nagpala, Ellaine Grace; Guidarelli, Michela; Gasperotti, Mattia; Masuero, Domenico; Bertolini, Paolo; Vrhovsek, Urska; Baraldi, Elena

    2016-03-01

    Strawberry (Fragaria × ananassa) fruit contains high concentrations of health-promoting phenolic compounds, playing important roles for the fruit ontogenic tolerance to fungi. In the highly susceptible cultivar Alba, the two major strawberry fungal pathogens, Colletotrichum acutatum and Botrytis cinerea, displayed disease symptoms only at red ripe stages because immature fruits are tolerant to diseases. We analyzed and compared the variation of 47 polyphenols in the surface of unripe and ripe Alba fruits upon 24 and 48 h of C. acutatum and B. cinerea infection or mock inoculation. Significant alteration in phenolic content was detected only in white infected fruit, with differences specific for each pathogen. The expression analysis of phenylpropanoid, flavonoid, and shikimate pathway genes showed in only a few cases correlation with the relative metabolite abundance. The alteration in phenolic content and the lack of consistency with gene expression data are discussed in light of previously reported metabolome data of different susceptible and resistant strawberry genotypes.

  9. Antagonistic potentiality of Trichoderma harzianum towards seed-borne fungal pathogens of winter wheat cv. Protiva in vitro and in vivo.

    Science.gov (United States)

    Hasan, M M; Rahman, S M E; Kim, Gwang-Hee; Abdallah, Elgorban; Oh, Deog-Hwan

    2012-05-01

    The antagonistic effect of Trichoderma harzianum on a range of seed-borne fungal pathogens of wheat (viz. Fusarium graminearum, Bipolaris sorokiniana, Aspergillus spp., and Penicillium spp.) was assessed. The potential of T. harzianum as a biocontrol agent was tested in vitro and under field conditions. Coculture of the pathogens and Trichoderma under laboratory conditions clearly showed dominance of T. harzianum. Under natural conditions, biocontrol effects were also obtained against the test fungi. One month after sowing, field emergence (plant stand) was increased by 15.93% over that obtained with the control treatment, and seedling infection was reduced significantly. Leaf blight severity was decreased from 22 to 11 at the heading stage, 35 to 31 at the flowering stage, and 86 to 74 at the grain filling stage. At harvest, the number of tillers per plant was increased by 50%, the yield was increased by 31.58%, and the 1,000-seed weight was increased by 21%.

  10. Evaluation of a Biological Pathogen Decontamination Protocol for Animal Feed Mills.

    Science.gov (United States)

    Huss, Anne R; Cochrane, Roger A; Deliephan, Aiswariya; Stark, Charles R; Jones, Cassandra K

    2015-09-01

    Animal feed and ingredients are potential vectors of pathogenic bacteria. Contaminated ingredients can contaminate facility equipment, leading to cross-contamination of other products. This experiment was conducted to evaluate a standardized protocol for decontamination of an animal feed manufacturing facility using Enterococcus faecium (ATCC 31282) as an indicator. A pelleted swine diet inoculated with E. faecium was manufactured, and environmental samples (swabs, replicate organism detection and counting plates, and air samples) were collected (i) before inoculation (baseline data), (ii) after production of inoculated feed, (iii) after physical removal of organic material using pressurized air, (iv) after application of a chemical sanitizer containing a quaternary ammonium-glutaraldehyde blend, (v) after application of a chemical sanitizer containing sodium hypochlorite, (vi) after facility heat-up to 60 8 C for 24 h, (vii) for 48 h, and (viii) for 72 h. Air samples collected outside the facility confirmed pathogen containment; E. faecium levels were equal to or lower than baseline levels at each sample location. The decontamination step and its associated interactions were the only variables that affected E. faecium incidence (P 0.22). After production of the inoculated diet, 85.7% of environmental samples were positive for E. faecium. Physical cleaning of equipment had no effect on contamination (P = 0.32). Chemical cleaning with a quaternary ammonium-glutaraldehyde blend and sodium hypochlorite each significantly reduced E. faecium contamination (P < 0.0001) to 28.6 and 2.4% of tested surfaces, respectively. All samples were negative for E. faecium after 48 h of heating. Both wet chemical cleaning and facility heating but not physical cleaning resulted in substantial E. faecium decontamination. These results confirmed both successful containment and decontamination of biological pathogens in the tested pilot-scale feed mill.

  11. Escherichia coli O157:H7 - An Emerging Pathogen in foods of Animal Origin

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    Ch. Bindu Kiranmayi

    Full Text Available Escherichia coli O157:H7 is an emerging public health concern in most countries of the world. E. coli O157:H7 was known to be a human pathogen for nearly 24 years. EHEC O157 infection is estimated to be the fourth most costly food borne disease in Canada and USA, not counting the cost of possible litigation. E. coli O157:H7 and Salmonella are the leading causes of produce related outbreaks, accounting for 20 and 30% respectively. The authority of the Federal Meat Inspection Act, FSIS (Food Safety and Inspection Service declared Escherichia coli O157:H7, an adulterant in raw ground beef and enforced “zero tolerance” (USDA-FSIS, 17 December 1998. Because of the severity of these illnesses and the apparent low infective dose (less than 10 cells, Escherichia coli O157:H7 is considered one of the most serious of known food borne pathogens. Escherichia coli O157:H7 is mainly pathogenic to human but in cattle and other animals, it did not induce any clinical disease except diarrhea. So, these animals act as carriers to Escherichia coli O157:H7. The majority transmission is through eating of undercooked contaminated ground meat and consumption of raw milk, raw vegetables, fruits contaminated by water, cheese, curd and also through consumption of sprouts, lettuce and juice. The conventional isolation procedure includes growth in enrichment broth like modified EC (E. coli broth or modified tryptic soy broth (mTSB Since the infection primarily occurs via faeco-oral route, the preventive measures include food hygiene measures like proper cooking of meat, consumption of pasteurized milk, washing fruits and vegetables especially those to be eaten raw and drinking chlorine treated water and personnel hygiene measures like washing hands after toilet visits. [Veterinary World 2010; 3(8.000: 382-389

  12. Identification and expression analysis of WRKY transcription factor genes in canola (Brassica napus L. in response to fungal pathogens and hormone treatments

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    Deyholos Michael K

    2009-06-01

    Full Text Available Abstract Background Members of plant WRKY transcription factor families are widely implicated in defense responses and various other physiological processes. For canola (Brassica napus L., no WRKY genes have been described in detail. Because of the economic importance of this crop, and its evolutionary relationship to Arabidopsis thaliana, we sought to characterize a subset of canola WRKY genes in the context of pathogen and hormone responses. Results In this study, we identified 46 WRKY genes from canola by mining the expressed sequence tag (EST database and cloned cDNA sequences of 38 BnWRKYs. A phylogenetic tree was constructed using the conserved WRKY domain amino acid sequences, which demonstrated that BnWRKYs can be divided into three major groups. We further compared BnWRKYs to the 72 WRKY genes from Arabidopsis and 91 WRKY from rice, and we identified 46 presumptive orthologs of AtWRKY genes. We examined the subcellular localization of four BnWRKY proteins using green fluorescent protein (GFP and we observed the fluorescent green signals in the nucleus only. The responses of 16 selected BnWRKY genes to two fungal pathogens, Sclerotinia sclerotiorum and Alternaria brassicae, were analyzed by quantitative real time-PCR (qRT-PCR. Transcript abundance of 13 BnWRKY genes changed significantly following pathogen challenge: transcripts of 10 WRKYs increased in abundance, two WRKY transcripts decreased after infection, and one decreased at 12 h post-infection but increased later on (72 h. We also observed that transcript abundance of 13/16 BnWRKY genes was responsive to one or more hormones, including abscisic acid (ABA, and cytokinin (6-benzylaminopurine, BAP and the defense signaling molecules jasmonic acid (JA, salicylic acid (SA, and ethylene (ET. We compared these transcript expression patterns to those previously described for presumptive orthologs of these genes in Arabidopsis and rice, and observed both similarities and differences in

  13. Anti-proliferative effect of fungal taxol extracted from Cladosporium oxysporum against human pathogenic bacteria and human colon cancer cell line HCT 15

    Science.gov (United States)

    Gokul Raj, K.; Manikandan, R.; Arulvasu, C.; Pandi, M.

    2015-03-01

    Cladosporium oxysporum a new taxol producing endophytic fungus was identified and production of taxol were characterized using UV-visible spectroscopy (UV-vis), high-performance liquid chromatography (HPLC), infrared (IR) nuclear magnetic resonance spectroscopy (NMR (13C and 1H)) and liquid chromatography-mass spectrometry (LC-MS). The taxol biosynthetic gene (dbat) was evaluated for new taxol producing fungus. Antibacterial activity against six different human pathogenic bacteria was done by agar well diffusion method. The anticancer efficacy of isolated fungal taxol were also evaluated in human colon cancer cell HCT 15 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cytotoxicity and nuclear morphology analysis. The isolated fungal taxol showed positive towards biosynthetic gene (dbat) and effective against both Gram positive as well as Gram negative. The fungal taxol suppress growth of cancer cell line HCT 15 with an IC50 value of 3.5 μM concentration by 24 h treatment. Thus, the result reveals that C. oxysporum could be a potential alternative source for production of taxol and have antibacterial as well as anticancer properties with possible clinical applications.

  14. Contamination with bacterial zoonotic pathogen genes in U.S. streams influenced by varying types of animal agriculture.

    Science.gov (United States)

    Haack, Sheridan K; Duris, Joseph W; Kolpin, Dana W; Focazio, Michael J; Meyer, Michael T; Johnson, Heather E; Oster, Ryan J; Foreman, William T

    2016-09-01

    Animal waste, stream water, and streambed sediment from 19 small (water or sediment sample in any control watershed. Post-rainfall pathogen gene numbers in stream water were significantly correlated with FIB, cholesterol and coprostanol concentrations, and were most highly correlated in dairy watershed samples collected from 3 different states. Although collected across multiple states and ecoregions, animal-waste gene profiles were distinctive via discriminant analysis. Stream water gene profiles could also be discriminated by the watershed animal type. Although pathogen genes were not abundant in stream water or streambed samples, PCR on enrichments indicated that many genes were from viable organisms, including several (shiga-toxin producing or enterotoxigenic E. coli, Salmonella, vancomycin-resistant enterococci) that could potentially affect either human or animal health. Pathogen gene numbers and types in stream water samples were influenced most by animal type, by local factors such as whether animals had stream access, and by the amount of local rainfall, and not by studied watershed soil or physical characteristics. Our results indicated that stream water in small agricultural U.S. watersheds was susceptible to pathogen gene inputs under typical agricultural practices and environmental conditions. Pathogen gene profiles may offer the potential to address both source of, and risks associated with, fecal pollution. PMID:27139306

  15. A rapid genotyping method for an obligate fungal pathogen, Puccinia striiformis f.sp. tritici, based on DNA extraction from infected leaf and Multiplex PCR genotyping

    Directory of Open Access Journals (Sweden)

    Enjalbert Jérôme

    2011-07-01

    Full Text Available Abstract Background Puccinia striiformis f.sp. tritici (PST, an obligate fungal pathogen causing wheat yellow/stripe rust, a serious disease, has been used to understand the evolution of crop pathogen using molecular markers. However, numerous questions regarding its evolutionary history and recent migration routes still remains to be addressed, which need the genotyping of a large number of isolates, a process that is limited by both DNA extraction and genotyping methods. To address the two issues, we developed here a method for direct DNA extraction from infected leaves combined with optimized SSR multiplexing. Findings We report here an efficient protocol for direct fungal DNA extraction from infected leaves, avoiding the costly and time consuming step of spore multiplication. The genotyping strategy we propose, amplified a total of 20 SSRs in three Multiplex PCR reactions, which were highly polymorphic and were able to differentiate different PST populations with high efficiency and accuracy. Conclusion These two developments enabled a genotyping strategy that could contribute to the development of molecular epidemiology of yellow rust disease, both at a regional or worldwide scale.

  16. Agrobacterium tumefaciens-mediated transformation of taro (Colocasia esculenta (L.) Schott) with a rice chitinase gene for improved tolerance to a fungal pathogen Sclerotium rolfsii.

    Science.gov (United States)

    He, Xiaoling; Miyasaka, Susan C; Fitch, Maureen M M; Moore, Paul H; Zhu, Yun J

    2008-05-01

    Taro (Colocasia esculenta) is one of the most important crops in the Pacific Islands, however, taro yields have been declining in Hawaii over the past 30 years partly due to diseases caused by oomycete and fungal pathogens. In this study, an efficient Agrobacterium tumefaciens-mediated transformation method for taro is first reported. In total, approximately 200 pieces (8 g) of embryogenic calluses were infected with the super-virulent A. tumefaciens strain EHA105 harboring the plant transformation plasmid pBI121/ricchi11 that contains the rice chitinase gene ricchi11. The presence and expression of the transgene ricchi11 in six independent transgenic lines was confirmed using polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR). Southern blot analysis of the six independent lines indicated that three out of six (50%) had integrated a single copy of the transgene, and the other three lines had two or three copies of the transgene. Compared to the particle bombardment transformation of taro method, which was used in the previous studies, the Agrobacterium-mediated transformation method obtained 43-fold higher transformation efficiency. In addition, these six transgenic lines via Agrobacterium may be more effective for transgene expression as a result of single-copy or low-copy insertion of the transgene than the single line with multiple copies of the transgene via particle bombardment. In a laboratory bioassay, all six transgenic lines exhibited increased tolerance to the fungal pathogen Sclerotium rolfsii, ranging from 42 to 63% reduction in lesion expansion.

  17. Effects of post-harvest treatment using chitosan from Mucor circinelloides on fungal pathogenicity and quality of table grapes during storage.

    Science.gov (United States)

    de Oliveira, Carlos Eduardo Vasconcelos; Magnani, Marciane; de Sales, Camila Veríssimo; Pontes, Alline Lima de Souza; Campos-Takaki, Galba Maria; Stamford, Thayza Christina Montenegro; de Souza, Evandro Leite

    2014-12-01

    The aim of this study was to extract chitosan (CHI) from Mucor circinelloides UCP 050 grown in a corn steep liquor (CSL)-based medium under optimized conditions and to assess the efficacy of the obtained CHI to inhibit the post-harvest pathogenic fungi Aspergillus niger URM 5162 and Rhizopus stolonifer URM 3482 in laboratory media and as a coating on table grapes (Vitis labrusca L.). The effect of CHI coating on some physical, physicochemical and sensory characteristics of the fruits during storage was assessed. The greatest amount of CHI was extracted from M. circinelloides UCP 050 grown in medium containing 7 g of CSL per 100 mL at pH 5.5 with rotation at 180 rpm. CHI from M. circinelloides UCP 050 caused morphological changes in the spores of the fungal strains tested and inhibited mycelial growth and spore germination. CHI coating delayed the growth of the assayed fungal strains in artificially infected grapes, as well as autochthonous mycoflora during storage. CHI coating preserved the quality of grapes during storage, as measured by their physical, physicochemical and sensory attributes. These results demonstrate that edible coatings derived from M. circinelloides CHI could be a useful alternative for controlling pathogenic fungi and maintaining the post-harvest quality of table grapes. PMID:25084665

  18. Isolation, identification of antagonistic rhizobacterial strains obtained from chickpea (cicer arietinum l.) field and their in-vitro evaluation against fungal root pathogens

    International Nuclear Information System (INIS)

    Plant growth promoting rhizobacteria (PGPR), are associated with roots, found in the rhizosphere and can directly or indirectly enhance the plant growth. In this study soil was collected from rhizosphere of chickpea fields of different areas of Rawalpindi division of Pakistan. PGPR were isolated, screened and characterized. Eight isolates of rhizobacteria (RHA, RPG, RFJ, RC, RTR, RT and RK) were isolated from Rawalpindi division and were characterized. The antagonistic activity of these PGPR isolates against root infecting fungi (Fusarium oxysporum and Verticillium spp.,) was done and production of indole acetic acid (IAA), siderophore and P-solubilization was evaluated. The isolates RHA, RPG, RFJ, RC, RRD and RT were found to be positive in producing siderophore, IAA and P-solubilization. Furthermore, most of the isolates showed antifungal activity against Fusarium oxysporum, and Verticillium spp. The rhizobacterial isolates RHA, RPG, RFJ, RC, RRD, RTR, RT and RK were used as bio-inoculants that might be beneficial for chickpea cultivation as the rhizobacterial isolates possessed the plant growth promoting characters i.e. siderophore, IAA production, phosphate solubilization. In in vitro tests, Pseudomonas sp. and Bacillus spp. inhibited the mycelial growth of the fungal root pathogens. The isolates (RHA and RPG) also significantly increased (60-70%) seed germination, shoot length, root length of the chickpea. The incidence of fungi was reduced by the colonization of RHA and RPG which enhanced the seedling vigor index and seed germination. The observations revealed that isolates RHA and RPG is quite effective to reduce the fungal root infection in greenhouse, and also increases seed yields significantly. These rhizobacterial isolates appear to be efficient yield increasing as well as effective biocontrol agent against fungal root pathogen. (author)

  19. Photosynthesis-dependent physiological and genetic crosstalk between cold acclimation and cold-induced resistance to fungal pathogens in triticale (Triticosecale Wittm.).

    Science.gov (United States)

    Szechyńska-Hebda, Magdalena; Wąsek, Iwona; Gołębiowska-Pikania, Gabriela; Dubas, Ewa; Żur, Iwona; Wędzony, Maria

    2015-04-01

    The breeding for resistance against fungal pathogens in winter triticale (Triticosecale Wittm.) continues to be hindered by a complexity of the resistance mechanisms, strong interaction with environmental conditions, and dependence on the plant genotype. We showed, that temperature below 4 °C induced the plant genotype-dependent resistance against the fungal pathogen Microdochium nivale. The mechanism involved, at least, the adjustment of the reactions in the PSII proximity and photoprotection, followed by an improvement of the growth and development. The genotypes capable to develop the cold-induced resistance, showed a higher maximum quantum yield of PSII and a more efficient integration of the primary photochemistry of light reactions with the dark reactions. Moreover, induction of the photoprotective mechanism, involving at least the peroxidases scavenging hydrogen peroxide, was observed for such genotypes. Adjustment of the photosynthesis and stress acclimation has enabled fast plant growth and avoidance of the developmental stages sensitive to fungal infection. The same mechanisms allowed the quick regrow of plants during the post-disease period. In contrast, genotypes that were unable to develop resistance despite cold hardening had less flexible balancing of the photoprotection and photoinhibition processes. Traits related to: photosynthesis-dependent cold-acclimation and cold-induced resistance; biomass accumulation and growth; as well as protection system involving peroxidases; were integrated also at a genetic level. Analysing 95 lines of the mapping population SaKa3006×Modus we determined region on chromosomes 5B and 7R shared within all tested traits. Moreover, similar expression pattern of a set of the genes related to PSII was determined with the metaanalysis of the multiple microarray experiments. Comparable results for peroxidases, involving APXs and GPXs and followed by PRXs, indicated a similar function during cold acclimation and defense

  20. Fungal arthritis

    Science.gov (United States)

    ... and irritation (inflammation) of a joint by a fungal infection. It is also called mycotic arthritis. Causes Fungal ... symptoms of fungal arthritis. Prevention Thorough treatment of fungal infections elsewhere in the body may help prevent fungal ...

  1. Real-time PCR for detection and quantification of fungal and oomycete tomato pathogens in plant and soil samples

    NARCIS (Netherlands)

    Lievens, B.; Brouwer, M.; Vanachter, A.C.R.C.; Cammue, B.P.A.; Thomma, B.P.H.J.

    2006-01-01

    Although new, rapid detection and identification technologies are becoming available more and more for various plant pathogens, pathogen quantification remains one of the main challenges in the disease management of many crops. Currently, real-time polymerase chain reaction (PCR) is the most straigh

  2. Application of enzyme linked immunosorbent assays to the diagnosis of the pathogenic animal trypanosomoses

    International Nuclear Information System (INIS)

    The pathogenic animal trypanosomoses comprise a number of diseases caused by different species of vector borne trypanosomes. In Africa, trypanosomes transmitted by tsetse flies (Glossina spp.) constitute a major constraint on socioeconomic development; over ten million km2 of sub-Saharan Africa are infested by the fly and 400 million livestock are at risk from infection with Trypanosoma congolense, T. vivax and T. brucei. Diseases caused by trypanosomes also occur outside the tsetse belt. Two trypanosome species are transmitted mechanically by haematophagous biting flies, mainly tabanids, and thereby have achieved a wider geographical distribution; T. evansi occurs in North Africa, Asia and South America, while a non-tsetse-transmitted form of T. vivax is found in South America. Animal trypanosomoses are difficult to diagnose: there are no pathognomonic signs, and detection of parasites is problematic. Therefore, considerable effort has been expended to develop serological assays with improved diagnostic sensitivity for use in obtaining information on the incidence and prevalence of infection and in the management of disease in the individual animal. Many different tests have been used over the past 70 years, but it is only recently that attention has been paid to test standardization, principally because of the introduction of enzyme linked immunosorbent assays (ELISAs) for the detection of trypanosomal antibodies and antigens. Although a variety of serological diagnostic techniques have been available for many years, there is still a lack of reliable data on trypanosomosis prevalence that makes economic justification and planning of control difficult to support. Clearly, enzyme immunoassays could provide this basic information. Additionally, as the emphasis moves from eradication to control of the tsetse transmitted trypanosomoses, there will be a greater need for surveillance and diagnosis of infection in individual animals. Both antigen and antibody assays can

  3. Photobacterium damselae subsp. damselae, a bacterium pathogenic for marine animals and humans

    Directory of Open Access Journals (Sweden)

    Amable J. Rivas

    2013-09-01

    Full Text Available Photobacterium damselae subsp. damselae (formerly Vibrio damsela is a pathogen of a variety of marine animals including fish, crustaceans, molluscs and cetaceans. In humans, it can cause opportunistic infections that may evolve into necrotizing fasciitis with fatal outcome. Although the genetic basis of virulence in this bacterium is not completely elucidated, recent findings demonstrate that the phospholipase-D Dly (damselysin and the pore-forming toxins HlyApl and HlyAch play a main role in virulence for homeotherms and poikilotherms. The acquisition of the virulence plasmid pPHDD1 that encodes Dly and HlyApl has likely constituted a main driving force in the evolution of a highly hemolytic lineage within the subspecies. Interestingly, strains that naturally lack pPHDD1 show a strong pathogenic potential for a variety of fish species, indicating the existence of yet uncharacterized virulence factors. Future and deep analysis of the complete genome sequence of P. damselae subsp. damselae will surely provide a clearer picture of the virulence factors employed by this bacterium to cause disease in such a varied range of hosts.

  4. Photobacterium damselae subsp. damselae, a bacterium pathogenic for marine animals and humans.

    Science.gov (United States)

    Rivas, Amable J; Lemos, Manuel L; Osorio, Carlos R

    2013-01-01

    Photobacterium damselae subsp. damselae (formerly Vibrio damsela) is a pathogen of a variety of marine animals including fish, crustaceans, molluscs, and cetaceans. In humans, it can cause opportunistic infections that may evolve into necrotizing fasciitis with fatal outcome. Although the genetic basis of virulence in this bacterium is not completely elucidated, recent findings demonstrate that the phospholipase-D Dly (damselysin) and the pore-forming toxins HlyApl and HlyAch play a main role in virulence for homeotherms and poikilotherms. The acquisition of the virulence plasmid pPHDD1 that encodes Dly and HlyApl has likely constituted a main driving force in the evolution of a highly hemolytic lineage within the subspecies. Interestingly, strains that naturally lack pPHDD1 show a strong pathogenic potential for a variety of fish species, indicating the existence of yet uncharacterized virulence factors. Future and deep analysis of the complete genome sequence of Photobacterium damselae subsp. damselae will surely provide a clearer picture of the virulence factors employed by this bacterium to cause disease in such a varied range of hosts. PMID:24093021

  5. X-ray crystallographic studies of two virulence factors from two fungal pathogens, P. marneffei and C. neoformans

    OpenAIRE

    林瑋熙; Lam, Wai-hei

    2012-01-01

    Mycoses refer to infections caused by different fungal infections. Some mycoses can be defeated by the hosts themselves attributed to the functional immune systems before severe symptoms appear. However, in immune-compromised patients, including those suffering from AIDS or receiving chemotherapies, those mycoses become lethal. They are called opportunistic systemic mycoses. Among them, two types of the most deadly mycoses, especially for AIDS patients in Southeast Asia, are cryptococcsis and...

  6. Colletotrichum truncatum species complex: Treatment considerations and review of the literature for an unusual pathogen causing fungal keratitis and endophthalmitis

    Directory of Open Access Journals (Sweden)

    Victoria Squissato

    2015-09-01

    Full Text Available We present a case of Colletotrichum truncatum species complex fungal keratitis and endophthalmitis in an 87-year-old immunocompetent male in whom oral triazole antifungals were contraindicated. The patient had recently returned from 4 months in Jamaica with a one month history of progressively increasing pain and inflammation in his left eye. Corneal samples grew a filamentous fungus and internal transcribed spacer sequencing polymerase chain reaction confirmed the presence of C. truncatum species complex. Samples showed no microbial growth.

  7. Post-genomic analyses of fungal lignocellulosic biomass degradation reveal the unexpected potential of the plant pathogen Ustilago maydis

    Directory of Open Access Journals (Sweden)

    Couturier Marie

    2012-02-01

    Full Text Available Abstract Background Filamentous fungi are potent biomass degraders due to their ability to thrive in ligno(hemicellulose-rich environments. During the last decade, fungal genome sequencing initiatives have yielded abundant information on the genes that are putatively involved in lignocellulose degradation. At present, additional experimental studies are essential to provide insights into the fungal secreted enzymatic pools involved in lignocellulose degradation. Results In this study, we performed a wide analysis of 20 filamentous fungi for which genomic data are available to investigate their biomass-hydrolysis potential. A comparison of fungal genomes and secretomes using enzyme activity profiling revealed discrepancies in carbohydrate active enzymes (CAZymes sets dedicated to plant cell wall. Investigation of the contribution made by each secretome to the saccharification of wheat straw demonstrated that most of them individually supplemented the industrial Trichoderma reesei CL847 enzymatic cocktail. Unexpectedly, the most striking effect was obtained with the phytopathogen Ustilago maydis that improved the release of total sugars by 57% and of glucose by 22%. Proteomic analyses of the best-performing secretomes indicated a specific enzymatic mechanism of U. maydis that is likely to involve oxido-reductases and hemicellulases. Conclusion This study provides insight into the lignocellulose-degradation mechanisms by filamentous fungi and allows for the identification of a number of enzymes that are potentially useful to further improve the industrial lignocellulose bioconversion process.

  8. In good company: association between fungal glycans generates molecular complexes with unique functions

    Directory of Open Access Journals (Sweden)

    Marcio eRodrigues

    2012-07-01

    Full Text Available The biological properties of fungal immunogens have historically utilized testing of isolated molecules. Recent findings, however, indicate that fungal glycans differing in structure and function can interact to form hybrid complexes with unique properties. In the pathogenic yeast Cryptococcus neoformans, chitin-like molecules associate with capsular glucuronoxylomannan to form functionally distinct glycan complexes. Such interactions between glycans that result in the formation of structures with different functions strongly suggest that additional molecular complexes with unknown properties may exist in fungal pathogens. Moreover, the identification of these novel complexes has stimulated the search of new immunogens with potential to protect human and animal hosts against systemic mycoses.

  9. Identification of fungal plant pathogens associated with oak (Quercus humboldtii Bonpl.), In the municipalities of Encino (Santander), Arcabuco, and Tipacoque (Boyaca)

    International Nuclear Information System (INIS)

    The objectives of this study were to isolate and determine the presence of the pathogen Phytophthora ramorum and other potential pathogens of Quercus humboldtii, and evaluate the possibility of using the antagonistic capacity of bacteria isolated from rhizosphere and phyllosphere against them. The study was conducted in the conservation corridor Guantiva - La Rusia - Iguaque, in the municipalities of Encino (Santander), Arcabuco and Tipacoque (Boyaca). The phytopathogenic fungi were isolated using direct seeding of leaves with symptoms of fungal infection in OGY, Sabouraud, and PDA + Lactic acid at 0.2%. We used the plate counting technique for the isolation of bacteria from rhizospheric and bulk soil. Phytophthora ramorum was not isolated, but phytopathogenic fungi of the genus Fusarium spp., and Pestalotia spp., were obtained in the isolates. Microbial populations of rhizospheric and bulk soil were scarce, exhibited low diversity, and were dominated by few morphotypes. We identified four species of bacteria: Pseudomonas fluorescens, Bacillus macerans, Pinus sylvestris and Staphylococcus epidermidis. The phyllosphere community was dominated by Pseudomonas fluorescens. The species Pseudomonas fluorescens and Pinus sylvestris did not exhibited antagonistic properties against Pestalotia spp. Further studies are required to confirm Fusarium spp., and Pestalotia spp., pathogenic activity against Quercus humboldtii.

  10. Climatic variation and seed persistence: freeze-thaw cycles lower survival via the joint action of abiotic stress and fungal pathogens.

    Science.gov (United States)

    Connolly, Brian M; Orrock, John L

    2015-10-01

    Global climate change is altering thermal cycles in soils during late winter, a transition that may directly threaten seed survival via abiotic stress, facilitate infection by soil-borne pathogens, or both. Using field-collected soil and seeds of the perennial bunchgrass Elymus canadensis, we tested the hypothesis that soil freeze-thaw events limit survival within the soil through direct effects on seed persistence and amplification of soil pathogen attack using a factorial experiment that manipulated freeze-thaw cycles (constant freeze vs. freeze-thaw) and fungicide addition. Freeze-thaw treatment resulted in lower seedling emergence and delayed emergence time relative to constant-freeze controls. Fungicide-treated soils had greater emergence relative to untreated soils; the lowest seedling emergence was observed in no-fungicide, freeze-thaw-treated soils (soil interface, as subsequent experiments showed that fungicide and freeze-thaw treatments alone do not influence dormancy. Our work demonstrates that changes in freeze-thaw events directly limit seedling emergence, delay seedling phenology, and provide opportunities for fungal pathogens to limit seed persistence. As recruitment from seeds is a key determinant of plant population dynamics, these results suggest that climatic variation may generate unique consequences for populations under changing climate regimes. PMID:26078006

  11. 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. PMID:26443032

  12. Natural Phenolic Inhibitors of Trichothecene Biosynthesis by the Wheat Fungal Pathogen Fusarium culmorum: A Computational Insight into the Structure-Activity Relationship

    Science.gov (United States)

    Pani, Giovanna; Dessì, Alessandro; Dallocchio, Roberto; Scherm, Barbara; Azara, Emanuela; Delogu, Giovanna

    2016-01-01

    A model of the trichodiene synthase (TRI5) of the wheat fungal pathogen and type-B trichothecene producer Fusarium culmorum was developed based on homology modelling with the crystallized protein of F. sporotrichioides. Eight phenolic molecules, namely ferulic acid 1, apocynin 2, propyl gallate 3, eugenol 4, Me-dehydrozingerone 5, eugenol dimer 6, magnolol 7, and ellagic acid 8, were selected for their ability to inhibit trichothecene production and/or fungal vegetative growth in F. culmorum. The chemical structures of phenols were constructed and partially optimised based on Molecular Mechanics (MM) studies and energy minimisation by Density Functional Theory (DFT). Docking analysis of the phenolic molecules was run on the 3D model of F. culmorum TRI5. Experimental biological activity, molecular descriptors and interacting-structures obtained from computational analysis were compared. Besides the catalytic domain, three privileged sites in the interaction with the inhibitory molecules were identified on the protein surface. The TRI5-ligand interactions highlighted in this study represent a powerful tool to the identification of new Fusarium-targeted molecules with potential as trichothecene inhibitors. PMID:27294666

  13. Antimicrobial mechanism of copper (II 1,10-phenanthroline and 2,2′-bipyridyl complex on bacterial and fungal pathogens

    Directory of Open Access Journals (Sweden)

    S. Chandraleka

    2014-12-01

    Full Text Available Copper based metallo drugs were prepared and their antibacterial, antifungal, molecular mechanism of [Cu(SAlaPhen]·H2O and [Cu(SAlabpy]·H2O complexes were investigated. The [Cu(SAlaPhen]·H2O and [Cu(SAlabpy]·H2O were derived from the Schiff base alanine salicylaldehyde. [Cu(SAlaPhen]·H2O showed noteworthy antibacterial and antifungal activity than the [Cu(SAlabpy]·H2O and ligand alanine, salicylaldehyde. The [Cu(SAlaPhen]·H2O complex showed significant antibacterial activity against Salmonella typhi, Staphylococcus aureus, Salmonella paratyphi and the antifungal activity against Candida albicans and Cryptococcus neoformans in well diffusion assay. The mode of action of copper (II complex was analyzed by DNA cleavage activity and in silico molecular docking. The present findings provide important insight into the molecular mechanism of copper (II complexes in susceptible bacterial and fungal pathogens. These results collectively support the use of [Cu(SAlaPhen]·H2O complex as a suitable drug to treat bacterial and fungal infections.

  14. In-Vitro Evaluation of Fungicides and Fungicide Combinations Against Fusarium Root-Rot Fungal Pathogens of French Beans(Phaseolus Vulgaris L. c v. Monel

    International Nuclear Information System (INIS)

    Laboratories studies were undertaken to evaluate In-vitro efficacy of captan, thiram, pyrazophos, triforine and metalaxyl + mancozeb fungicides against Fusarium solani (Mart.) Appel and Wollenw fsp. phaseoli (Burk) Synder and Hansen Fusarium oxysporum Schlecht fsp. phaseoli kend and Synder root-rot fungal pathogens of French beans. Five fungicides and four combinations were tested for their antifungal activity. Fungicides treatments significantly (P=0.05) inhibited mycelial growth and spore germination. Fungicides suppressed the growth of F. oxysporum fsp. Phaseoli more than that of F. solani fsp. phaseoli. All fungicides except metalaxyl + mancozeb failed to suppress sporulation of the two fungi In-vitro. In the case of thiram the sporulation capacity of F. oxysporum fsp. phaseoli 3.43 times higher than in the control. Although, no fungicides treatment was seen to inhibitor of all the three measures of fungitoxicity, the ranking of the best three fungicide treatments would be, thiram 50 + captan so > triforine > metalaxyl + mancozeb. The relatively higher inhibitory effect of fungicides on the growth of F. oxysporum Ssp. Phaseoli than that of F. solani fsp. Phaseoli suggested that F. oxysporum Esp. Phaseoli was more sensible to fungicide treatments. Such differences may reflect inherent variations in accessibility of the active toxicants within the fungal systems. The ability attributed to the low growth rate, N depletion temperature and oxygen

  15. Autophagy provides nutrients for nonassimilating fungal structures and is necessary for plant colonization but not for infection in the necrotrophic plant pathogen Fusarium graminearum

    DEFF Research Database (Denmark)

    Josefsen, Lone; Droce, Aida; Søndergaard, Teis;

    2012-01-01

    The role of autophagy in necrotrophic fungal physiology and infection biology is poorly understood. We have studied autophagy in the necrotrophic plant pathogen Fusarium graminearum in relation to development of nonassimilating structures and infection. We identified an ATG8 homolog F. graminearum...... starvation is severely inhibited in the Delta Fgatg8 strain demonstrating autophagy-dependent lipid utilization, lipophagy, in fungi. Radial growth rate of the Delta Fgatg8 strain is reduced compared with the wild type and the mutant does not grow over inert plastic surfaces in contrast to the wild type....... The ability to infect barley and wheat is normal but the mutant is unable to spread from spikelet to spikelet in wheat. Complementation by inserting the F. graminearum atg8 gene into a region adjacent to the actin gene in Delta Fgatg8 fully restores the WT phenotype. The results showed that autophagy plays...

  16. Finished genome of the fungal wheat pathogen Mycosphaerella graminicola reveals dispensome structure, chromosome plasticity, and stealth pathogenesis.

    Directory of Open Access Journals (Sweden)

    Stephen B Goodwin

    2011-06-01

    Full Text Available The plant-pathogenic fungus Mycosphaerella graminicola (asexual stage: Septoria tritici causes septoria tritici blotch, a disease that greatly reduces the yield and quality of wheat. This disease is economically important in most wheat-growing areas worldwide and threatens global food production. Control of the disease has been hampered by a limited understanding of the genetic and biochemical bases of pathogenicity, including mechanisms of infection and of resistance in the host. Unlike most other plant pathogens, M. graminicola has a long latent period during which it evades host defenses. Although this type of stealth pathogenicity occurs commonly in Mycosphaerella and other Dothideomycetes, the largest class of plant-pathogenic fungi, its genetic basis is not known. To address this problem, the genome of M. graminicola was sequenced completely. The finished genome contains 21 chromosomes, eight of which could be lost with no visible effect on the fungus and thus are dispensable. This eight-chromosome dispensome is dynamic in field and progeny isolates, is different from the core genome in gene and repeat content, and appears to have originated by ancient horizontal transfer from an unknown donor. Synteny plots of the M. graminicola chromosomes versus those of the only other sequenced Dothideomycete, Stagonospora nodorum, revealed conservation of gene content but not order or orientation, suggesting a high rate of intra-chromosomal rearrangement in one or both species. This observed "mesosynteny" is very different from synteny seen between other organisms. A surprising feature of the M. graminicola genome compared to other sequenced plant pathogens was that it contained very few genes for enzymes that break down plant cell walls, which was more similar to endophytes than to pathogens. The stealth pathogenesis of M. graminicola probably involves degradation of proteins rather than carbohydrates to evade host defenses during the biotrophic

  17. A novel extracellular metallopeptidase domain shared by animal host-associated mutualistic and pathogenic microbes.

    Directory of Open Access Journals (Sweden)

    Sirintra Nakjang

    Full Text Available The mucosal microbiota is recognised as an important factor for our health, with many disease states linked to imbalances in the normal community structure. Hence, there is considerable interest in identifying the molecular basis of human-microbe interactions. In this work we investigated the capacity of microbes to thrive on mucosal surfaces, either as mutualists, commensals or pathogens, using comparative genomics to identify co-occurring molecular traits. We identified a novel domain we named M60-like/PF13402 (new Pfam entry PF13402, which was detected mainly among proteins from animal host mucosa-associated prokaryotic and eukaryotic microbes ranging from mutualists to pathogens. Lateral gene transfers between distantly related microbes explained their shared M60-like/PF13402 domain. The novel domain is characterised by a zinc-metallopeptidase-like motif and is distantly related to known viral enhancin zinc-metallopeptidases. Signal peptides and/or cell surface anchoring features were detected in most microbial M60-like/PF13402 domain-containing proteins, indicating that these proteins target an extracellular substrate. A significant subset of these putative peptidases was further characterised by the presence of associated domains belonging to carbohydrate-binding module family 5/12, 32 and 51 and other glycan-binding domains, suggesting that these novel proteases are targeted to complex glycoproteins such as mucins. An in vitro mucinase assay demonstrated degradation of mammalian mucins by a recombinant form of an M60-like/PF13402-containing protein from the gut mutualist Bacteroides thetaiotaomicron. This study reveals that M60-like domains are peptidases targeting host glycoproteins. These peptidases likely play an important role in successful colonisation of both vertebrate mucosal surfaces and the invertebrate digestive tract by both mutualistic and pathogenic microbes. Moreover, 141 entries across various peptidase families described

  18. Chlorhexidine Digluconate Effects on Planktonic Growth and Biofilm Formation in Some Field Isolates of Animal Bacterial Pathogens

    OpenAIRE

    Ebrahimi, Azizollah; Hemati, Majid; Habibian Dehkordi, Saeed; Bahadoran, Shahab; Khoshnood, Sheida; Khubani, Shahin; Dokht Faraj, Mahdi; Hakimi Alni, Reza

    2014-01-01

    Background: To study chlorhexidine digluconate disinfectant effects on planktonic growth and biofilm formation in some bacterial field isolates from animals. Objectives: The current study investigated chlorhexidine digluconate effects on planktonic growth and biofilm formation in some field isolates of veterinary bacterial pathogens. Materials and Methods: Forty clinical isolates of Escherichia coli, Salmonella serotypes, Staphylococcus. aureus and Streptococcus agalactiae (10 isolates for ea...

  19. Systems Biology of Fungal Infection

    OpenAIRE

    FabianHorn; ThorstenHeinekamp; JohannesPollmächer; AxelABrakhage

    2012-01-01

    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 i...

  20. The role of infochemicals in the interaction between cassava green mite and its fungal pathogen Neozygites tanajoae

    NARCIS (Netherlands)

    F.C.C. Hountondji; M.W. Sabelis; R. Hanna

    2006-01-01

    The role of infochemicals in mediating interactions between herbivores and their foraging natural enemies, mainly predators and parasitoids, is well established, but very little is known about infochemical use in interactions between herbivores and their sit-and-wait pathogens. This paper reviews th

  1. Finished Genome of the Fungal Wheat Pathogen Mycosphaerella graminicola Reveals Dispensome Structure, Chromosome Plasticity, and Stealth Pathogenesis

    NARCIS (Netherlands)

    Goodwin, S.B.; M'Barek, Ben S.; Dhillon, B.; Wittenberg, A.H.J.; Crane, C.F.; Hane, J.K.; Foster, A.J.; Lee, van der T.A.J.; Grimwood, J.; Aerts, A.; Antoniw, J.; Bailey, A.; Bluhm, B.; Bowler, J.; Bristow, J.; Burgt, van der A.; Canto-Canché, B.; Churchill, A.C.L.; Conde-Ferràez, L.; Cools, H.J.; Coutinho, P.M.; Csukai, M.; Dehal, P.; Wit, de P.J.G.M.; Donzelli, B.; Geest, van de H.C.; Ham, van R.C.H.J.; Hammond-Kosack, K.E.; Henrissat, B.; Kilian, A.; Kobayashi, A.K.; Koopmann, E.; Kourmpetis, Y.; Kuzniar, A.; Lindquist, E.; Lombard, V.; Maliepaard, C.A.; Martins, N.; Mehrabi, A.; Nap, J.P.H.; Ponomarenko, A.; Rudd, J.J.; Salamov, A.; Schmutz, J.; Schouten, H.J.; Shapiro, H.; Stergiopoulos, I.; Torriani, S.F.F.; Tu, H.; Vries, de R.P.; Waalwijk, C.; Ware, S.B.; Wiebenga, A.; Zwiers, L.H.; Oliver, R.P.; Grigoriev, I.V.; Kema, G.H.J.

    2011-01-01

    The plant-pathogenic fungus Mycosphaerella graminicola (asexual stage: Septoria tritici) causes septoria tritici blotch, a disease that greatly reduces the yield and quality of wheat. This disease is economically important in most wheat-growing areas worldwide and threatens global food production. C

  2. MoFLP1, encoding a novel fungal fasciclin-like protein, is involved in conidiation and pathogenicity in Magnaporthe oryzae

    Institute of Scientific and Technical Information of China (English)

    Tong-bao LIU; Guo-qing CHEN; Hang MIN; Fuc-heng LIN

    2009-01-01

    Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtractive suppressive cDNA library and functionally analyzed. Sequence analysis showed that the MoFLP1 gene contains an open reading frame (ORF) of 1050 nucleotides encoding 349 amino acids with a calculated molecular weight of 35.85 kDa and a pl of 7.76. The deduced MoFLP1 protein contains a 17-amino acid secretion signal sequence and an 18-amino acid sequence with the characteristics of a glycosylphosphotidylinositol (GPI) anchor additional signal at its N- and C-terminuses, respectively. Potential N-glycosylation sites and domains involving cell adhesion were also identified in MoFLP1. Sequence analysis and subcellular localization by the expression of MoFLP1-GFP fusion construct in M. oryzae indicated that the MoFLP1 protein is probably localized on the vacuole membrane. Two MoFLP1 null mutants generated by targeted gene disruption exhibited marked reduction ofconidiation, conidiai adhesion, appressorium turgot, and pathogenicity. Our results indicate that fasciclin proteins play important roles in fungal development and pathogenicity in M. oryzae.

  3. Tissue-specific and pathogen-inducible expression of a fusion protein containing a Fusarium-specific antibody and a fungal chitinase protects wheat against Fusarium pathogens and mycotoxins.

    Science.gov (United States)

    Cheng, Wei; Li, He-Ping; Zhang, Jing-Bo; Du, Hong-Jie; Wei, Qi-Yong; Huang, Tao; Yang, Peng; Kong, Xian-Wei; Liao, Yu-Cai

    2015-06-01

    Fusarium head blight (FHB) in wheat and other small grain cereals is a globally devastating disease caused by toxigenic Fusarium pathogens. Controlling FHB is a challenge because germplasm that is naturally resistant against these pathogens is inadequate. Current control measures rely on fungicides. Here, an antibody fusion comprised of the Fusarium spp.-specific recombinant antibody gene CWP2 derived from chicken, and the endochitinase gene Ech42 from the biocontrol fungus Trichoderma atroviride was introduced into the elite wheat cultivar Zhengmai9023 by particle bombardment. Expression of this fusion gene was regulated by the lemma/palea-specific promoter Lem2 derived from barley; its expression was confirmed as lemma/palea-specific in transgenic wheat. Single-floret inoculation of independent transgenic wheat lines of the T3 to T6 generations revealed significant resistance (type II) to fungal spreading, and natural infection assays in the field showed significant resistance (type I) to initial infection. Gas chromatography-mass spectrometry analysis revealed marked reduction of mycotoxins in the grains of the transgenic wheat lines. Progenies of crosses between the transgenic lines and the FHB-susceptible cultivar Huamai13 also showed significantly enhanced FHB resistance. Quantitative real-time PCR analysis revealed that the tissue-specific expression of the antibody fusion was induced by salicylic acid drenching and induced to a greater extent by F. graminearum infection. Histochemical analysis showed substantial restriction of mycelial growth in the lemma tissues of the transgenic plants. Thus, the combined tissue-specific and pathogen-inducible expression of this Fusarium-specific antibody fusion can effectively protect wheat against Fusarium pathogens and reduce mycotoxin content in grain.

  4. Overexpression of TaPIEP1, a pathogen-induced ERF gene of wheat, confers host-enhanced resistance to fungal pathogen Bipolaris sorokiniana.

    Science.gov (United States)

    Dong, Na; Liu, Xin; Lu, Yan; Du, Lipu; Xu, Huijun; Liu, Hongxia; Xin, Zhiyong; Zhang, Zengyan

    2010-05-01

    Bipolaris sorokiniana is an economically important phytopathogen of wheat and other cereal species. In this paper, a novel pathogen-induced ethylene-responsive factor (ERF) gene of wheat, TaPIEP1, was isolated and characterized. The transcript of TaPIEP1 was significantly and rapidly induced by treatments with B. sorokiniana, and with ethylene (ET), jasmonate (JA), and abscisic acid. Molecular and biochemical assays demonstrated that TaPIEP1 is a new ERF transcription activator belonging to B-3c subgroup of the ERF family. Transgenic wheat lines overexpressing TaPIEP1 were generated by biolistic bombardment and molecular screening. Compared with the host wheat Yangmai12, six stable transgenic wheat lines overexpressing TaPIEP1 that exhibited significantly increased resistance to B. sorokiniana were identified by molecular detection in the T(0)-T(4) generations and by disease resistance tests. The degree of the enhanced resistance was correlated with an accumulation of the transcript level of TaPIEP1. Furthermore, the transcript levels of certain defense-related genes in the ET/JA pathways were markedly increased in the transgenic wheat plants with enhanced resistance. These results reveal that TaPIEP1 overexpression in wheat could obviously improve resistance to B. sorokiniana via activation of some defense genes, and TaPIEP1 gene may be useful in improving crop resistance to the pathogen.

  5. Fusion of two divergent fungal individuals led to the recent emergence of a unique widespread pathogen species

    Science.gov (United States)

    Stukenbrock, Eva Holtgrewe; Christiansen, Freddy Bugge; Hansen, Troels Toftebjerg; Dutheil, Julien Yann; Schierup, Mikkel Heide

    2012-01-01

    In a genome alignment of five individuals of the ascomycete fungus Zymoseptoria pseudotritici, a close relative of the wheat pathogen Z. tritici (synonym Mycosphaerella graminicola), we observed peculiar diversity patterns. Long regions up to 100 kb without variation alternate with similarly long regions of high variability. The variable segments in the genome alignment are organized into two main haplotype groups that have diverged ∼3% from each other. The genome patterns in Z. pseudotritici are consistent with a hybrid speciation event resulting from a cross between two divergent haploid individuals. The resulting hybrids formed the new species without backcrossing to the parents. We observe no variation in 54% of the genome in the five individuals and estimate a complete loss of variation for at least 30% of the genome in the entire species. A strong population bottleneck following the hybridization event caused this loss of variation. Variable segments in the Z. pseudotritici genome exhibit the two haplotypes contributed by the parental individuals. From our previously estimated recombination map of Z. tritici and the size distribution of variable chromosome blocks untouched by recombination we estimate that the hybridization occurred ∼380 sexual generations ago. We show that the amount of lost variation is explained by genetic drift during the bottleneck and by natural selection, as evidenced by the correlation of presence/absence of variation with gene density and recombination rate. The successful spread of this unique reproductively isolated pathogen highlights the strong potential of hybridization in the emergence of pathogen species with sexual reproduction. PMID:22711811

  6. Inverse pH regulation of plant and fungal sucrose transporters: a mechanism to regulate competition for sucrose at the host/pathogen interface?

    Directory of Open Access Journals (Sweden)

    Kathrin Wippel

    Full Text Available BACKGROUND: Plant sucrose transporter activities were shown to respond to changes in the extracellular pH and redox status, and oxidizing compounds like glutathione (GSSG or H(2O(2 were reported to effect the subcellular targeting of these proteins. We hypothesized that changes in both parameters might be used to modulate the activities of competing sucrose transporters at a plant/pathogen interface. We, therefore, compared the effects of redox-active compounds and of extracellular pH on the sucrose transporters UmSRT1 and ZmSUT1 known to compete for extracellular sucrose in the Ustilago maydis (corn smut/Zea mays (maize pathosystem. METHODOLOGY/PRINCIPAL FINDINGS: We present functional analyses of the U. maydis sucrose transporter UmSRT1 and of the plant sucrose transporters ZmSUT1 and StSUT1 in Saccharomyces cerevisiae or in Xenopus laevis oocytes in the presence of different extracellular pH-values and redox systems, and study the possible effects of these treatments on the subcellular targeting. We observed an inverse regulation of host and pathogen sucrose transporters by changes in the apoplastic pH. Under none of the conditions analyzed, we could confirm the reported effects of redox-active compounds. CONCLUSIONS/SIGNIFICANCE: Our data suggest that changes in the extracellular pH but not of the extracellular redox status might be used to oppositely adjust the transport activities of plant and fungal sucrose transporters at the host/pathogen interface.

  7. Isolation, antibiogram and pathogenicity of Salmonella spp. Recovered from slaughtered food animals in Nagpur region of Central India

    Directory of Open Access Journals (Sweden)

    D. G. Kalambhe

    2016-02-01

    Full Text Available Aim: To determine the prevalence, antibiogram and pathogenicity of Salmonella spp. in the common food animals slaughtered for consumption purpose at government approved slaughter houses located in and around Nagpur region during a period of 2010-2012. Materials and Methods: A total of 400 samples comprising 50 each of blood and meat from each slaughtered male cattle, buffaloes, pigs and goats were collected. Isolation was done by pre-enrichment in buffered peptone water and enrichment in Rappaport-Vassiliadis broth with subsequent selective plating onto xylose lysine deoxycholate agar. Presumptive Salmonella colonies were biochemically confirmed and analyzed for pathogenicity by hemolysin production and Congo red dye binding assay (CRDA. An antibiotic sensitivity test was performed to assess the antibiotic resistance pattern of the isolates. Results: A total of 10 isolates of Salmonella spp. from meat (3 from cattle, 1 from buffaloes and 6 from pigs with an overall prevalence of 5% among food animals was recorded. No isolation was reported from any blood samples. Pathogenicity assays revealed 100% and 80% positivity for CRDA and hemolytic activity, respectively. Antimicrobial sensitivity test showed multi-drug resistance. The overall resistance of 50% was noted for trimethoprim followed by ampicillin (20%. A maximum sensitivity (80% was reported to gentamycin followed by 40% each to ampicillin and trimethoprim, 30% to amikacin and 10% to kanamycin. Conclusion: The presence of multidrug resistant and potentially pathogenic Salmonella spp. in slaughtered food animals in Nagpur region can be a matter of concern for public health.

  8. Tick-borne pathogens and associated co-infections in ticks collected from domestic animals in central China

    OpenAIRE

    Chen, Zhuo; Liu, Qin; Liu, Ji-Qi; Xu, Bian-Li; Lv, Shan; Xia, Shang; Zhou, Xiao-Nong

    2014-01-01

    Background Ticks can transmit a number of pathogens to humans and domestic animals. Tick borne diseases (TBDs), which may lead to organ failure and death have been recently reported in China. 98.75% of the total cases (>1000) in Henan provinces have been reported in Xinyang city. Therefore, the aims of this study were to investigate the fauna of ticks and detect the potential pathogens in ticks in Xinyang, the region of central China. Methods Ticks were collected from 10 villages of Xinyang f...

  9. Rice transformation with cell wall degrading enzyme genes from Trichoderma atroviride and its effect on plant growth and resistance to fungal pathogens

    Institute of Scientific and Technical Information of China (English)

    Liu Mei; Sun Zong-Xiu; Zhu Jie; Xu Tong; Gary E Harman; Matteo Lorito; Sheri Woo

    2004-01-01

    @@ Three genes encoding for fungal cell wall degrading enzymes (CWDE), ech42, nag70 and gluc78from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305. 2 singly and in all possible combinations. The coding sequences were placed downstream of the rice actin promoter and all vectors were used to transform rice plants. A total of more than 1,800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. Expression in plant was obtained for all the fungal genes used singly or in combinations. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had a lesser effect. The expression level of endochitinase but not of the exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the positive effect of endochitinase on disease resistance when two genes were co-expressed in transgenic rice. Improved resistance to Magnaporthe grisea was found in all types of regenerated plants, including those with the gluc78 gene alone, while a few lines expressing either ech42 or nag70 appeared to be immune to this pathogen. Transgenic plants expressing the gluc78 gene alone were stunted and only few of them survived, even though they showed resistance to M. grisea. However, combination with either one of the two other genes ( ech42, nag70 ) as included in the same T-DNA region, reduced the negative effect of gluc78 on plant growth. This is the first report of single or multiple of expression of transgens encoding CWDEs that results in resistance to blast and sheath blight in rice.

  10. Filamentous fungal-specific septin AspE is phosphorylated in vivo and interacts with actin, tubulin and other septins in the human pathogen Aspergillus fumigatus

    Energy Technology Data Exchange (ETDEWEB)

    Juvvadi, Praveen Rao; Belina, Detti [Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, NC (United States); Soderblom, Erik J.; Moseley, M. Arthur [Duke Proteomics Core Facility, Institute for Genome Sciences and Policy, Duke University, Durham, NC (United States); Steinbach, William J., E-mail: bill.steinbach@duke.edu [Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, NC (United States); Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC (United States)

    2013-02-15

    Highlights: ► In vivo interactions of the novel septin AspE were identified by GFP-Trap® affinity purification. ► Septins AspA, AspB, AspC and AspD interacted with AspE in vivo. ► Actin and tubulin interacted with AspE in vivo. ► AspE is phosphorylated at six serine residues in vivo. -- Abstract: We previously analyzed the differential localization patterns of five septins (AspA–E), including a filamentous fungal-specific septin, AspE, in the human pathogen Aspergillus fumigatus. Here we utilized the A. fumigatus strain expressing an AspE–EGFP fusion protein and show that this novel septin with a tubular localization pattern in hyphae is phosphorylated in vivo and interacts with the other septins, AspA, AspB, AspC and AspD. The other major proteins interacting with AspE included the cytoskeletal proteins, actin and tubulin, which may be involved in the organization and transport of the septins. This is the first report analyzing the phosphorylation of AspE and localizing the sites of phosphorylation, and opens opportunities for further analysis on the role of post-translational modifications in the assembly and organization of A. fumigatus septins. This study also describes the previously unknown interaction of AspE with the actin-microtubule network. Furthermore, the novel GFP-Trap® affinity purification method used here complements widely-used GFP localization studies in fungal systems.

  11. Enhancing rice resistance to fungal pathogens by transformation with cell wall degrading enzyme genes from Trichoderma atroviride

    Institute of Scientific and Technical Information of China (English)

    刘梅; 孙宗修; 朱洁; 徐同; HARMANGaryE; LORITOMatteo

    2004-01-01

    Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance to Magnaporthe grisea was found in all kinds of regenerated plants including that with single gluc78. A few lines expressing either ech42 or nag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs from Trichoderma atroviride that result in resistance to blast and sheath blight in rice.

  12. A soluble fucose-specific lectin from Aspergillus fumigatus conidia--structure, specificity and possible role in fungal pathogenicity.

    Science.gov (United States)

    Houser, Josef; Komarek, Jan; Kostlanova, Nikola; Cioci, Gianluca; Varrot, Annabelle; Kerr, Sheena C; Lahmann, Martina; Balloy, Viviane; Fahy, John V; Chignard, Michel; Imberty, Anne; Wimmerova, Michaela

    2013-01-01

    Aspergillus fumigatus is an important allergen and opportunistic pathogen. Similarly to many other pathogens, it is able to produce lectins that may be involved in the host-pathogen interaction. We focused on the lectin AFL, which was prepared in recombinant form and characterized. Its binding properties were studied using hemagglutination and glycan array analysis. We determined the specificity of the lectin towards l-fucose and fucosylated oligosaccharides, including α1-6 linked core-fucose, which is an important marker for cancerogenesis. Other biologically relevant saccharides such as sialic acid, d-mannose or d-galactose were not bound. Blood group epitopes of the ABH and Lewis systems were recognized, Le(Y) being the preferred ligand among others. To provide a correlation between the observed functional characteristics and structural basis, AFL was crystallized in a complex with methyl-α,L-selenofucoside and its structure was solved using the SAD method. Six binding sites, each with different compositions, were identified per monomer and significant differences from the homologous AAL lectin were found. Structure-derived peptides were utilized to prepare anti-AFL polyclonal antibodies, which suggested the presence of AFL on the Aspergillus' conidia, confirming its expression in vivo. Stimulation of human bronchial cells by AFL led to IL-8 production in a dose-dependent manner. AFL thus probably contributes to the inflammatory response observed upon the exposure of a patient to A. fumigatus. The combination of affinity to human epithelial epitopes, production by conidia and pro-inflammatory activity is remarkable and shows that AFL might be an important virulence factor involved in an early stage of A. fumigatus infection.

  13. Lipid transfer proteins (nsLTPs) from barley and maize leaves are potent inhibitors of bacterial and fungal plant pathogens

    OpenAIRE

    Molina Fernández, Antonio; Segura, Ana; García Olmedo, Francisco

    1993-01-01

    Four homogeneous proteins (Cw18, Cw20, Cw21, Cw22) were isolated from etiolated barley leaves by extraction of the insoluble pellet from a Tris-HCl (pH 7.5) homogenate with 1.5 M LiCl and fractionation by reverse-phase high-performance liquid chromatography. All 4 proteins inhibited growth of the pathogen Clavibacter michiganensis subsp. sepedonicus (EC50S = 1−3 × 10−7 M) and had closely related N-terminal amino acid sequences. The complete amino acid sequences of proteins Cw18 and Cw21 were ...

  14. Dandruff-associated Malassezia genomes reveal convergent and divergent virulence traits shared with plant and human fungal pathogens

    NARCIS (Netherlands)

    Xu, Jun; Saunders, Charles W.; Hu, Ping; Grant, Raymond A.; Boekhout, Teun; Kuramae, Eiko E.; Kronstad, James W.; DeAngelis, Yvonne M.; Reeder, Nancy L.; Johnstone, Kevin R.; Leland, Meredith; Fieno, Angela M.; Begley, William M.; Sun, Yiping; Lacey, Martin P.; Chaudhary, Tanuja; Keough, Thomas; Chu, Lien; Sears, Russell; Yuan, Bo; Dawson, Thomas L.

    2007-01-01

    Fungi in the genus Malassezia are ubiquitous skin residents of humans and other warm-blooded animals. Malassezia are involved in disorders including dandruff and seborrheic dermatitis, which together affect > 50% of humans. Despite the importance of Malassezia in common skin diseases, remarkably lit

  15. Dandruff-associated Malassezia genomes reveal convergent and divergent virulence traits shared with plant and human fungal pathogens

    NARCIS (Netherlands)

    Xu, J.; Saunders, C.; Hu, P.; Grant, R.A.; Boekhout, T.; Kuramae, E.E.; Kronstad, J.W.; DeAngelis, Y.M.; Reeder, N.L.; Johnstone, K.R.; Leland, M.; Fieno, A.M.; Begley, W.M.; Sun, Y.; Lacey, M.P.; Chaudhary, T.; Keough, T.; Chu, L.; Sears, R.; Yuan, B.; Dawson Jr., T.L.

    2007-01-01

    Fungi in the genus Malassezia are ubiquitous skin residents of humans and other warm-blooded animals. Malassezia are involved in disorders including dandruff and seborrheic dermatitis, which together affect >50% of humans. Despite the importance of Malassezia in common skin diseases, remarkably litt

  16. Characterization of a JAZ7 activation-tagged Arabidopsis mutant with increased susceptibility to the fungal pathogen Fusarium oxysporum.

    Science.gov (United States)

    Thatcher, Louise F; Cevik, Volkan; Grant, Murray; Zhai, Bing; Jones, Jonathan D G; Manners, John M; Kazan, Kemal

    2016-04-01

    In Arabidopsis, jasmonate (JA)-signaling plays a key role in mediating Fusarium oxysporum disease outcome. However, the roles of JASMONATE ZIM-domain (JAZ) proteins that repress JA-signaling have not been characterized in host resistance or susceptibility to this pathogen. Here, we found most JAZ genes are induced following F. oxysporum challenge, and screening T-DNA insertion lines in Arabidopsis JAZ family members identified a highly disease-susceptible JAZ7 mutant (jaz7-1D). This mutant exhibited constitutive JAZ7 expression and conferred increased JA-sensitivity, suggesting activation of JA-signaling. Unlike jaz7 loss-of-function alleles, jaz7-1D also had enhanced JA-responsive gene expression, altered development and increased susceptibility to the bacterial pathogen PstDC3000 that also disrupts host JA-responses. We also demonstrate that JAZ7 interacts with transcription factors functioning as activators (MYC3, MYC4) or repressors (JAM1) of JA-signaling and contains a functional EAR repressor motif mediating transcriptional repression via the co-repressor TOPLESS (TPL). We propose through direct TPL recruitment, in wild-type plants JAZ7 functions as a repressor within the JA-response network and that in jaz7-1D plants, misregulated ectopic JAZ7 expression hyper-activates JA-signaling in part by disturbing finely-tuned COI1-JAZ-TPL-TF complexes.

  17. Rapidly Evolving Genes Are Key Players in Host Specialization and Virulence of the Fungal Wheat Pathogen Zymoseptoria tritici (Mycosphaerella graminicola.

    Directory of Open Access Journals (Sweden)

    Stephan Poppe

    2015-07-01

    Full Text Available The speciation of pathogens can be driven by divergent host specialization. Specialization to a new host is possible via the acquisition of advantageous mutations fixed by positive selection. Comparative genome analyses of closely related species allows for the identification of such key substitutions via inference of genome-wide signatures of positive selection. We previously used a comparative genomics framework to identify genes that have evolved under positive selection during speciation of the prominent wheat pathogen Zymoseptoria tritici (synonym Mycosphaerella graminicola. In this study, we conducted functional analyses of four genes exhibiting strong signatures of positive selection in Z. tritici. We deleted the four genes in Z. tritici and confirm a virulence-related role of three of the four genes ΔZt80707, ΔZt89160 and ΔZt103264. The two mutants ΔZt80707 and ΔZt103264 show a significant reduction in virulence during infection of wheat; the ΔZt89160 mutant causes a hypervirulent phenotype in wheat. Mutant phenotypes of ΔZt80707, ΔZt89160 and ΔZt103264 can be restored by insertion of the wild-type genes. However, the insertion of the Zt80707 and Zt89160 orthologs from Z. pseudotritici and Z. ardabiliae do not restore wild-type levels of virulence, suggesting that positively selected substitutions in Z. tritici may relate to divergent host specialization. Interestingly, the gene Zt80707 encodes also a secretion signal that targets the protein for cell secretion. This secretion signal is however only transcribed in Z. tritici, suggesting that Z. tritici-specific substitutions relate to a new function of the protein in the extracellular space of the wheat-Z. tritici interaction. Together, the results presented here highlight that Zt80707, Zt103264 and Zt89160 represent key genes involved in virulence and host-specific disease development of Z. tritici. Our findings illustrate that evolutionary predictions provide a powerful tool

  18. Rapidly Evolving Genes Are Key Players in Host Specialization and Virulence of the Fungal Wheat Pathogen Zymoseptoria tritici (Mycosphaerella graminicola)

    Science.gov (United States)

    Poppe, Stephan; Dorsheimer, Lena; Happel, Petra; Stukenbrock, Eva Holtgrewe

    2015-01-01

    The speciation of pathogens can be driven by divergent host specialization. Specialization to a new host is possible via the acquisition of advantageous mutations fixed by positive selection. Comparative genome analyses of closely related species allows for the identification of such key substitutions via inference of genome-wide signatures of positive selection. We previously used a comparative genomics framework to identify genes that have evolved under positive selection during speciation of the prominent wheat pathogen Zymoseptoria tritici (synonym Mycosphaerella graminicola). In this study, we conducted functional analyses of four genes exhibiting strong signatures of positive selection in Z. tritici. We deleted the four genes in Z. tritici and confirm a virulence-related role of three of the four genes ΔZt80707, ΔZt89160 and ΔZt103264. The two mutants ΔZt80707 and ΔZt103264 show a significant reduction in virulence during infection of wheat; the ΔZt89160 mutant causes a hypervirulent phenotype in wheat. Mutant phenotypes of ΔZt80707, ΔZt89160 and ΔZt103264 can be restored by insertion of the wild-type genes. However, the insertion of the Zt80707 and Zt89160 orthologs from Z. pseudotritici and Z. ardabiliae do not restore wild-type levels of virulence, suggesting that positively selected substitutions in Z. tritici may relate to divergent host specialization. Interestingly, the gene Zt80707 encodes also a secretion signal that targets the protein for cell secretion. This secretion signal is however only transcribed in Z. tritici, suggesting that Z. tritici-specific substitutions relate to a new function of the protein in the extracellular space of the wheat-Z. tritici interaction. Together, the results presented here highlight that Zt80707, Zt103264 and Zt89160 represent key genes involved in virulence and host-specific disease development of Z. tritici. Our findings illustrate that evolutionary predictions provide a powerful tool for the

  19. Projecting the Global Distribution of the Emerging Amphibian Fungal Pathogen, Batrachochytrium dendrobatidis, Based on IPCC Climate Futures

    Science.gov (United States)

    Olson, Deanna H.; Blaustein, Andrew R.

    2016-01-01

    Projected changes in climate conditions are emerging as significant risk factors to numerous species, affecting habitat conditions and community interactions. Projections suggest species range shifts in response to climate change modifying environmental suitability and is supported by observational evidence. Both pathogens and their hosts can shift ranges with climate change. We consider how climate change may influence the distribution of the emerging infectious amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), a pathogen associated with worldwide amphibian population losses. Using an expanded global Bd database and a novel modeling approach, we examined a broad set of climate metrics to model the Bd-climate niche globally and regionally, then project how climate change may influence Bd distributions. Previous research showed that Bd distribution is dependent on climatic variables, in particular temperature. We trained a machine-learning model (random forest) with the most comprehensive global compilation of Bd sampling records (~5,000 site-level records, mid-2014 summary), including 13 climatic variables. We projected future Bd environmental suitability under IPCC scenarios. The learning model was trained with combined worldwide data (non-region specific) and also separately per region (region-specific). One goal of our study was to estimate of how Bd spatial risks may change under climate change based on the best available data. Our models supported differences in Bd-climate relationships among geographic regions. We projected that Bd ranges will shift into higher latitudes and altitudes due to increased environmental suitability in those regions under predicted climate change. Specifically, our model showed a broad expansion of areas environmentally suitable for establishment of Bd on amphibian hosts in the temperate zones of the Northern Hemisphere. Our projections are useful for the development of monitoring designs in these areas, especially for

  20. Preliminary in vitro insights into the use of natural fungal pathogens of leaf-cutting ants as biocontrol agents.

    Science.gov (United States)

    Folgarait, Patricia; Gorosito, Norma; Poulsen, Michael; Currie, Cameron R

    2011-09-01

    Leaf-cutting ants are one of the main herbivores of the Neotropics, where they represent an important agricultural pest. These ants are particularly difficult to control because of the complex network of microbial symbionts. Leaf-cutting ants have traditionally been controlled through pesticide application, but there is a need for alternative, more environmentally friendly, control methods such as biological control. Potential promising biocontrol candidates include the microfungi Escovopsis spp. (anamorphic Hypocreales), which are specialized pathogens of the fungi the ants cultivate for food. These pathogens are suppressed through ant behaviors and ant-associated antibiotic-producing Actinobacteria. In order to be an effective biocontrol agent, Escovopsis has to overcome these defenses. Here, we evaluate, using microbial in vitro assays, whether defenses in the ant-cultivated fungus strain (Leucoagaricus sp.) and Actinobacteria from the ant pest Acromyrmex lundii have the potential to limit the use of Escovopsis in biocontrol. We also explore, for the first time, possible synergistic biocontrol between Escovopsis and the entomopathogenic fungus Lecanicillium lecanii. All strains of Escovopsis proved to overgrow A. lundii cultivar in less than 7 days, with the Escovopsis strain isolated from a different leaf-cutting ant species being the most efficient. Escovopsis challenged with a Streptomyces strain isolated from A. lundii did not exhibit significant growth inhibition. Both results are encouraging for the use of Escovopsis as a biocontrol agent. Although we found that L. lecanii can suppress the growth of the cultivar, it also had a negative impact on Escovopsis, making the success of simultaneous use of these two fungi for biocontrol of A. lundii questionable. PMID:21739253

  1. Physical protection against airborne pathogens and pollutants by a novel animal isolator in a level 3 containment laboratory.

    OpenAIRE

    Wathes, C M; Johnson, H. E.

    1991-01-01

    A containment laboratory unit for research with aerosols of group 2 pathogenic microorganisms is described. The design criteria are based on current UK guidelines, which imply containment at group 3 level during aerosol production, storage, exposure of animals and sampling. Within the aerosol laboratory, primary containment is provided by a Henderson apparatus operating at a negative pressure to the external environment. Flexible film isolators under negative pressure are used for all hazardo...

  2. Widespread Distribution of a Tet W Determinant among Tetracycline-Resistant Isolates of the Animal Pathogen Arcanobacterium pyogenes

    OpenAIRE

    Billington, Stephen J.; Songer, J Glenn; Jost, B. Helen

    2002-01-01

    Tetracycline resistance is common among isolates of the animal commensal and opportunistic pathogen Arcanobacterium pyogenes. The tetracycline resistance determinant cloned from two bovine isolates of A. pyogenes was highly similar at the DNA level (92% identity) to the tet(W) gene, encoding a ribosomal protection tetracycline resistance protein, from the rumen bacterium Butyrivibrio fibrisolvens. The tet(W) gene was found in all 20 tetracycline-resistant isolates tested, indicating that it i...

  3. The genomes of the fungal plant pathogens Cladosporium fulvum and Dothistroma septosporum reveal adaptation to different hosts and lifestyles but also signatures of common ancestry.

    Science.gov (United States)

    de Wit, Pierre J G M; van der Burgt, Ate; Ökmen, Bilal; Stergiopoulos, Ioannis; Abd-Elsalam, Kamel A; Aerts, Andrea L; Bahkali, Ali H; Beenen, Henriek G; Chettri, Pranav; Cox, Murray P; Datema, Erwin; de Vries, Ronald P; Dhillon, Braham; Ganley, Austen R; Griffiths, Scott A; Guo, Yanan; Hamelin, Richard C; Henrissat, Bernard; Kabir, M Shahjahan; Jashni, Mansoor Karimi; Kema, Gert; Klaubauf, Sylvia; Lapidus, Alla; Levasseur, Anthony; Lindquist, Erika; Mehrabi, Rahim; Ohm, Robin A; Owen, Timothy J; Salamov, Asaf; Schwelm, Arne; Schijlen, Elio; Sun, Hui; van den Burg, Harrold A; van Ham, Roeland C H J; Zhang, Shuguang; Goodwin, Stephen B; Grigoriev, Igor V; Collemare, Jérôme; Bradshaw, Rosie E

    2012-01-01

    We sequenced and compared the genomes of the Dothideomycete fungal plant pathogens Cladosporium fulvum (Cfu) (syn. Passalora fulva) and Dothistroma septosporum (Dse) that are closely related phylogenetically, but have different lifestyles and hosts. Although both fungi grow extracellularly in close contact with host mesophyll cells, Cfu is a biotroph infecting tomato, while Dse is a hemibiotroph infecting pine. The genomes of these fungi have a similar set of genes (70% of gene content in both genomes are homologs), but differ significantly in size (Cfu >61.1-Mb; Dse 31.2-Mb), which is mainly due to the difference in repeat content (47.2% in Cfu versus 3.2% in Dse). Recent adaptation to different lifestyles and hosts is suggested by diverged sets of genes. Cfu contains an α-tomatinase gene that we predict might be required for detoxification of tomatine, while this gene is absent in Dse. Many genes encoding secreted proteins are unique to each species and the repeat-rich areas in Cfu are enriched for these species-specific genes. In contrast, conserved genes suggest common host ancestry. Homologs of Cfu effector genes, including Ecp2 and Avr4, are present in Dse and induce a Cf-Ecp2- and Cf-4-mediated hypersensitive response, respectively. Strikingly, genes involved in production of the toxin dothistromin, a likely virulence factor for Dse, are conserved in Cfu, but their expression differs markedly with essentially no expression by Cfu in planta. Likewise, Cfu has a carbohydrate-degrading enzyme catalog that is more similar to that of necrotrophs or hemibiotrophs and a larger pectinolytic gene arsenal than Dse, but many of these genes are not expressed in planta or are pseudogenized. Overall, comparison of their genomes suggests that these closely related plant pathogens had a common ancestral host but since adapted to different hosts and lifestyles by a combination of differentiated gene content, pseudogenization, and gene regulation.

  4. Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

    Directory of Open Access Journals (Sweden)

    Miguel J Beltrán-García

    Full Text Available In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg. Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg, a highly reactive oxygen specie (ROS that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg. A pigmented-strain generated more O2 (1Δg than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2 but we cannot distinguish the source. Our results suggest that O2 (1Δg photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

  5. Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

    Science.gov (United States)

    Beltrán-García, Miguel J; Prado, Fernanda M; Oliveira, Marilene S; Ortiz-Mendoza, David; Scalfo, Alexsandra C; Pessoa, Adalberto; Medeiros, Marisa H G; White, James F; Di Mascio, Paolo

    2014-01-01

    In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg). Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN)-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg), a highly reactive oxygen specie (ROS) that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis) were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg). A pigmented-strain generated more O2 (1Δg) than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2) but we cannot distinguish the source. Our results suggest that O2 (1Δg) photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

  6. The Genomes of the Fungal Plant Pathogens Cladosporium fulvum and Dothistroma septosporum Reveal Adaptation to Different Hosts and Lifestyles But Also Signatures of Common Ancestry

    Energy Technology Data Exchange (ETDEWEB)

    de Wit, Pierre J. G. M.; van der Burgt, Ate; Okmen, Bilal; Stergiopoulos, Ioannis; Abd-Elsalam, Kamel A.; Aerts, Andrea L.; Bahkali, Ali H.; Beenen, Henriek G.; Chettri, Oranav; Cos, Murray P.; Datema, Erwin; de Vries, Ronald P.; DHillon, Braham; Ganley, Austen R.; Griffiths, Scott A.; Guo, Yanan; Gamelin, Richard C.; Henrissat, Bernard; Kabir, M. Shahjahan; Jashni, Mansoor Karimi; Kema, Gert; Klaubauf, Sylvia; Lapidus, Alla; Levasseur, Anthony; Lindquist, Erika; Mehrabi, Rahim; Ohm, Robin A.; Owen, Timothy J.; Salamov, Asaf; Schwelm, Arne; Schijlen, Elio; Sun, Hui; van den Burg, Harrold A.; van Burg, Roeland C. H. J.; Zhang, Shuguang; Goodwin, Stephen B.; Grigoriev, Igor V.; Collemare, Jerome; Bradshaw, Rosie E.

    2012-05-04

    We sequenced and compared the genomes of the Dothideomycete fungal plant pathogens Cladosporium fulvum (Cfu) (syn. Passalora fulva) and Dothistroma septosporum (Dse) that are closely related phylogenetically, but have different lifestyles and hosts. Although both fungi grow extracellularly in close contact with host mesophyll cells, Cfu is a biotroph infecting tomato, while Dse is a hemibiotroph infecting pine. The genomes of these fungi have a similar set of genes (70percent of gene content in both genomes are homologs), but differ significantly in size (Cfu >61.1-Mb; Dse 31.2-Mb), which is mainly due to the difference in repeat content (47.2percent in Cfu versus 3.2percent in Dse). Recent adaptation to different lifestyles and hosts is suggested by diverged sets of genes. Cfu contains an tomatinase gene that we predict might be required for detoxification of tomatine, while this gene is absent in Dse. Many genes encoding secreted proteins are unique to each species and the repeat-rich areas in Cfu are enriched for these species-specific genes. In contrast, conserved genes suggest common host ancestry. Homologs of Cfu effector genes, including Ecp2 and Avr4, are present in Dse and induce a Cf-Ecp2- and Cf-4-mediated hypersensitive response, respectively. Strikingly, genes involved in production of the toxin dothistromin, a likely virulence factor for Dse, are conserved in Cfu, but their expression differs markedly with essentially no expression by Cfu in planta. Likewise, Cfu has a carbohydrate-degrading enzyme catalog that is more similar to that of necrotrophs or hemibiotrophs and a larger pectinolytic gene arsenal than Dse, but many of these genes are not expressed in planta or are pseudogenized. Overall, comparison of their genomes suggests that these closely related plant pathogens had a common ancestral host but since adapted to different hosts and lifestyles by a combination of differentiated gene content, pseudogenization, and gene regulation.

  7. Transcriptional Activation and Production of Tryptophan-Derived Secondary Metabolites in Arabidopsis Roots Contributes to the Defense against the Fungal Vascular Pathogen Verticillium Iongisporum

    Institute of Scientific and Technical Information of China (English)

    Tim Iven; Wolfgang Dr(o)ge-Laser; Stefanie K(o)nig; Seema Singh; Susanna A.Braus-Stromeyer; Matthias Bischoff; Lutz F.Tietze; Gerhard H.Braus; Volker Lipka; Ivo Feussner

    2012-01-01

    The soil-borne fungal pathogen Verticillium Iongisporum causes vascular disease on Brassicaceae host plants such as oilseed rape.The fungus colonizes the root xylem and moves upwards to the foliage where disease symptoms become visible.Using Arabidopsis as a model for early gene induction,we performed root transcriptome analyses in response to hyphal growth immediately after spore germination and during penetration of the root cortex,respectively.Infected roots showed a rapid reprogramming of gene expression such as activation of transcription factors,stress-,and defense-related genes.Here,we focused on the highly coordinated gene induction resulting in the production of tryptophan-derived secondary metabolites.Previous studies in leaves showed that enzymes encoded by CYP81F2 and PEN2 (PENETRATION2) execute the formation of antifungal indole glucosinolate (IGS) metabolites.In Verticillium-infected roots.we found transcriptional activation of CYP81F2 and the PEN2 homolog PEL1 (PEN2-LIKE1),but no increase in antifungal IGS breakdown products.In contrast,indole-3-carboxylic acid (I3CA) and the phytoalexin camalexin accumulated in infected roots but only camalexin inhibited Verticillium growth in vitro.Whereas genetic disruption of the individual metabolic pathways leading to either camalexin or CYP81F2-dependent IGS metabolites did not alter Verticillium-induced disease symptoms,a cyp79b2 cyp79b3 mutant impaired in both branches resulted in significantly enhanced susceptibility.Hence,our data provide an insight into root-specific early defenses and suggest tryptophan-derived metabolites as active antifungal compounds against a vascular pathogen.

  8. Changes occurring in compositions and antioxidant properties of healthy soybean seeds [Glycine max (L.) Merr.] and soybean seeds diseased by Phomopsis longicolla and Cercospora kikuchii fungal pathogens.

    Science.gov (United States)

    Lee, Jin Hwan; Hwang, Seung-Ryul; Lee, Yeon-Hee; Kim, Kyun; Cho, Kye Man; Lee, Yong Bok

    2015-10-15

    Changes in the compositions (isoflavone, protein, oil, and fatty acid) and antioxidant properties were evaluated in healthy soybeans and soybeans diseased by Phomopsis longicolla and Cercospora kikuchii. The total isoflavone content (1491.3 μg/g) of healthy seeds was observed to be considerably different than that of diseased seeds (P. longicolla: 292.6, C. kikuchii: 727.2 μg/g), with malonlygenistin exhibiting the greatest decrease (726.1 → 57.1, 351.9 μg/g). Significantly, three isoflavones exhibited a slight increase, and their structures were confirmed as daidzein, glycitein, and genistein, based on their molecular ions at m/z 253.1, 283.0, and 269.1 using the negative mode of HPLC-DAD-ESI/MS. The remaining compositions showed slight variations. The effects against 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radicals in healthy seeds were stronger than the diseased soybeans, depending upon the isoflavone level. Our results may be useful in evaluating the relationship between composition and antioxidant activity as a result of changes caused by soybean fungal pathogens.

  9. Disease risk assessments involving companion animals: an overview for 15 selected pathogens taking a European perspective

    OpenAIRE

    Rijks, J. M.; Cito, F.; Cunningham, A. A.; Rantsios, A. T.; Givannini, A.

    2015-01-01

    Prioritization of companion animal transmissible diseases was performed by the Companion Animals multisectoriaL interprofessionaL Interdisciplinary Strategic Think tank On zoonoses (CALLISTO) project. The project considered diseases occurring in domesticated species commonly kept as pets, such as dogs and cats, but also included diseases occurring in captive wild animals and production animal species. The prioritization process led to the selection of 15 diseases of prime public health releva...

  10. Antibiotic Pattern of Some Pathogenic Bacteria Isolated from Animal and It’s Relation to Human Infections

    Directory of Open Access Journals (Sweden)

    A. Alhababi

    2011-04-01

    Full Text Available The present study was done on 186 isolates obtained from both animals (107 isolates and patients (79 isolates. The study aimed at comparing the antimicrobial patterns of pathogens isolated from animal and human cases (nosocomial infections. The isolates were identified and the antibiograms were reported. The results pointed out that E. coli was the most common isolate followed by Pseudomonas aeruginosa in human samples, while in animal samples the most common Gram negative isolates recovered were Pseudomonas aeruginosa followed by Proteus spp. On the other hand, Staphylococcus aureus was the most common Gram positive isolate in animal and human samples. Conclude that, both animal and human isolates were markedly resistant to different types of antibacterial agents. However, animal isolates compared with human isolates showed more resistance to most of the used antibacterial agents. This can be attributed to the fact that in our country, animals are generally exposed to several antibacterial agents either as therapeutic, prophylactic or as growth promoter agents.

  11. Impact on Arbuscular Mycorrhiza Formation of Pseudomonas Strains Used as Inoculants for Biocontrol of Soil-Borne Fungal Plant Pathogens

    Science.gov (United States)

    Barea, J. M.; Andrade, G.; Bianciotto, V.; Dowling, D.; Lohrke, S.; Bonfante, P.; O’Gara, F.; Azcon-Aguilar, C.

    1998-01-01

    The arbuscular mycorrhizal symbiosis, a key component of agroecosystems, was assayed as a rhizosphere biosensor for evaluation of the impact of certain antifungal Pseudomonas inoculants used to control soil-borne plant pathogens. The following three Pseudomonas strains were tested: wild-type strain F113, which produces the antifungal compound 2,4-diacetylphloroglucinol (DAPG); strain F113G22, a DAPG-negative mutant of F113; and strain F113(pCU203), a DAPG overproducer. Wild-type strain F113 and mutant strain F113G22 stimulated both mycelial development from Glomus mosseae spores germinating in soil and tomato root colonization. Strain F113(pCU203) did not adversely affect G. mosseae performance. Mycelial development, but not spore germination, is sensitive to 10 μM DAPG, a concentration that might be present in the rhizosphere. The results of scanning electron and confocal microscopy demonstrated that strain F113 and its derivatives adhered to G. mosseae spores independent of the ability to produce DAPG. PMID:9603857

  12. Population structure and temporal maintenance of the multihost fungal pathogen Botrytis cinerea: causes and implications for disease management.

    Science.gov (United States)

    Walker, Anne-Sophie; Gladieux, Pierre; Decognet, Véronique; Fermaud, Marc; Confais, Johann; Roudet, Jean; Bardin, Marc; Bout, Alexandre; Nicot, Philippe C; Poncet, Christine; Fournier, Elisabeth

    2015-04-01

    Understanding the causes of population subdivision is of fundamental importance, as studying barriers to gene flow between populations may reveal key aspects of the process of adaptive divergence and, for pathogens, may help forecasting disease emergence and implementing sound management strategies. Here, we investigated population subdivision in the multihost fungus Botrytis cinerea based on comprehensive multiyear sampling on different hosts in three French regions. Analyses revealed a weak association between population structure and geography, but a clear differentiation according to the host plant of origin. This was consistent with adaptation to hosts, but the distribution of inferred genetic clusters and the frequency of admixed individuals indicated a lack of strict host specificity. Differentiation between individuals collected in the greenhouse (on Solanum) and outdoor (on Vitis and Rubus) was stronger than that observed between individuals from the two outdoor hosts, probably reflecting an additional isolating effect associated with the cropping system. Three genetic clusters coexisted on Vitis but did not persist over time. Linkage disequilibrium analysis indicated that outdoor populations were regularly recombining, whereas clonality was predominant in the greenhouse. Our findings open up new perspectives for disease control by managing plant debris in outdoor conditions and reinforcing prophylactic measures indoor. PMID:25040694

  13. Allergen Immunotherapy in an HIV+ Patient with Allergic Fungal Rhinosinusitis

    OpenAIRE

    Myles, Ian A.; Satyen Gada

    2015-01-01

    Patients with HIV/AIDS can present with multiple types of fungal rhinosinusitis, fungal balls, granulomatous invasive fungal rhinosinusitis, acute or chronic invasive fungal rhinosinusitis, or allergic fungal rhinosinusitis (AFRS). Given the variable spectrum of immune status and susceptibility to severe infection from opportunistic pathogens it is extremely important that clinicians distinguish aggressive fungal invasive fungal disease from the much milder forms such as AFRS. Here we descr...

  14. Screening and modes of action of antagonistic bacteria to control the fungal pathogen Phaeomoniella chlamydospora involved in grapevine trunk diseases.

    Science.gov (United States)

    Haidar, Rana; Roudet, Jean; Bonnard, Olivier; Dufour, Marie Cécile; Corio-Costet, Marie France; Fert, Mathieu; Gautier, Thomas; Deschamps, Alain; Fermaud, Marc

    2016-11-01

    The antagonistic activity of 46 bacterial strains isolated from Bordeaux vineyards were evaluated against Phaeomoniella chlamydospora, a major grapevine pathogen involved in Esca. The reduction of the necrosis length of stem cuttings ranged between 31.4% and 38.7% for the 8 most efficient strains. Two in planta trials allowed the selection of the two best strains, Bacillus pumilus (S32) and Paenibacillus sp. (S19). Their efficacy was not dependent on application method; co-inoculation, prevention in the wood and soil inoculation were tested. The involvement of antibiosis by the secretion of diffusible and/or volatile compounds in the antagonistic capacity of these two strains was assessed in vitro. Volatile compounds secreted by B. pumilus (S32) and Paenibacillus sp. (S19) were identified by gas chromatography/mass spectroscopy (GC/MS). The volatile compounds 1-octen-3-ol and 2,5-dimethyl pyrazine were obtained commercially and tested, and they showed strong antifungal activity against P. chlamydospora, which suggested that these compounds may play an important role in the bacterial antagonistic activity in planta. Furthermore, the expression of 10 major grapevine defense genes was quantified by real-time polymerase chain reaction, which demonstrated that the two strains significantly affected the grapevine transcripts four days after their application on the plants. High expression levels of different genes associated with P. chlamydospora infection in B. pumilus pre-treated plants suggests that this strain induces systemic resistance in grapevine. For the first time, we demonstrated the ability of two bacterial strains, B. pumilus and Paenibacillus sp., isolated from grapevine wood, to control P. chlamydospora via direct and/or indirect mechanisms. PMID:27664735

  15. Common motifs in the response of cereal primary metabolism to fungal pathogens are not based on similar transcriptional reprogramming

    Directory of Open Access Journals (Sweden)

    Lars Matthias Voll

    2011-08-01

    Full Text Available During compatible interactions with their host plants, biotrophic plant pathogens subvert host metabolism to ensure the sustained provision of nutrient assimilates by the colonized host cells. To investigate, whether common motifs can be revealed in the response of primary carbon and nitrogen metabolism towards colonization with biotrophic fungi in cereal leaves, we have conducted a combined metabolome and transcriptome study of three quite divergent pathosystems, the barley powdery mildew fungus (Blumeria graminis f.sp. hordei, the corn smut fungus Ustilago maydis and the maize anthracnose fungus Colletotrichum graminicola, the latter being a hemibiotroph that only exhibits an initial biotrophic phase during its establishment.Based on the analysis of 42 water-soluble metabolites, we were able to separate early biotrophic from late biotrophic interactions by hierarchical cluster analysis and principal component analysis, irrespective of the plant host. Interestingly, the corresponding transcriptome dataset could not discriminate between these stages of biotrophy, irrespective, of whether transcript data for genes of central metabolism or the entire transcriptome dataset was used. Strong differences in the transcriptional regulation of photosynthesis, glycolysis, the TCA cycle, lipid biosynthesis, and cell wall metabolism were observed between the pathosystems. Increased contents of Gln, Asn, and glucose as well as diminished contents of PEP and 3-PGA were common to early post-penetration stages of all interactions. On the transcriptional level, genes of the TCA cycle, nucleotide energy metabolism and amino acid biosynthesis exhibited consistent trends among the compared biotrophic interactions, identifying the requirement for metabolic energy and the rearrangement of amino acid pools as common transcriptional motifs during early biotrophy. Both metabolome and transcript data were employed to generate models of leaf primary metabolism during

  16. Veterinary education in the area of food safety (including animal health, food pathogens and surveillance of foodborne diseases).

    Science.gov (United States)

    Vidal, S M; Fajardo, P I; González, C G

    2013-08-01

    The animal foodstuffs industry has changed in recent decades as a result of factors such as: human population growth and longer life expectancy, increasing urbanisation and migration, emerging zoonotic infectious diseases and foodborne diseases (FBDs), food security problems, technological advances in animal production systems, globalisation of trade and environmental changes. The Millennium Development Goals and the 'One Health' paradigm provide global guidelines on efficiently addressing the issues of consumer product safety, food security and risks associated with zoonoses. Professionals involved in the supply chain must therefore play an active role, based on knowledge and skills that meet current market requirements. Accordingly, it is necessary for the veterinary medicine curriculum, both undergraduate and postgraduate, to incorporate these skills. This article analyses the approach that veterinary education should adopt in relation to food safety, with an emphasis on animal health, food pathogens and FBD surveillance.

  17. Chemical ecology of animal and human pathogen vectors in a changing global climate.

    Science.gov (United States)

    Pickett, John A; Birkett, Michael A; Dewhirst, Sarah Y; Logan, James G; Omolo, Maurice O; Torto, Baldwyn; Pelletier, Julien; Syed, Zainulabeuddin; Leal, Walter S

    2010-01-01

    Infectious diseases affecting livestock and human health that involve vector-borne pathogens are a global problem, unrestricted by borders or boundaries, which may be exacerbated by changing global climate. Thus, the availability of effective tools for control of pathogen vectors is of the utmost importance. The aim of this article is to review, selectively, current knowledge of the chemical ecology of pathogen vectors that affect livestock and human health in the developed and developing world, based on key note lectures presented in a symposium on "The Chemical Ecology of Disease Vectors" at the 25th Annual ISCE meeting in Neuchatel, Switzerland. The focus is on the deployment of semiochemicals for monitoring and control strategies, and discusses briefly future directions that such research should proceed along, bearing in mind the environmental challenges associated with climate change that we will face during the 21st century. PMID:20119869

  18. Microbial Indicators, Pathogens, and Antibiotic Resistance in Groundwater Impacted by Animal Farming: Field Scale to Basin Scale

    Science.gov (United States)

    Harter, T.; Li, X.; Atwill, E. R.; Packman, A. I.

    2015-12-01

    Several surveys of microbial indicators and pathogens were conducted to determine the impact of confined animal farming operations (CAFOs) on shallow, local, and regional groundwater quality in the Central Valley aquifer system, California. The aquifer system consists of highly heterogeneous, alluvial, unconsolidated coarse- to fine-grained sediments and is among the largest aquifers in the U.S.. Overlying landuse includes 3 million ha of irrigated agriculture and 1.7 million mature dairy cows in nearly 1,500 CAFOs. A multi-scale survey of water-borne indicator pathogens (Enterococcus spp. and generic E. coli) and of three water-borne pathogens (Campylobacter, Salmonella, and E. coli O157:H7) was conducted at five different spatial scales, increasing with distance from animal sources of these enteric microbial organisms: moist surfaces within individual CAFO sub-systems (calf-hutches, heifer corrals, mature cow stalls, hospital barn etc.), first encountered (shallow) groundwater immediately below these sub-systems, production aquifer below CAFOs, production aquifer near CAFOs, and production aquifer away from CAFOs. Where found, indicator pathogens were tested for antibiotic resistance. Hundreds of samples were collected at each scale: continuously during irrigation events and seasonally over a multi-year period at the three smaller site-scales; and in a one-time survey at the two larger, regional scales. All three pathogens were frequently detected in moist surface samples across CAFO sub-systems, albeit at concentrations several orders of magnitude lower than enteric indicators. Two of the three pathogens (but not Campylobacter) were also detected in first encountered groundwater, at 3-9 m below ground surface, in 1% of samples. No pathogens were found at the production aquifer scales. Generic E. coli was detected in ¼ of first encountered groundwater samples, and in 4% of production aquifer samples, while Enterococcus spp. was ubiquitously present across the

  19. Fungal osteomyelitis and septic arthritis.

    Science.gov (United States)

    Bariteau, Jason T; Waryasz, Gregory R; McDonnell, Matthew; Fischer, Staci A; Hayda, Roman A; Born, Christopher T

    2014-06-01

    Management of fungal osteomyelitis and fungal septic arthritis is challenging, especially in the setting of immunodeficiency and conditions that require immunosuppression. Because fungal osteomyelitis and fungal septic arthritis are rare conditions, study of their pathophysiology and treatment has been limited. In the literature, evidence-based treatment is lacking and, historically, outcomes have been poor. The most common offending organisms are Candida and Aspergillus, which are widely distributed in humans and soil. However, some fungal pathogens, such as Histoplasma, Blastomyces, Coccidioides, Cryptococcus, and Sporothrix, have more focal areas of endemicity. Fungal bone and joint infections result from direct inoculation, contiguous infection spread, or hematogenous seeding of organisms. These infections may be difficult to diagnose and eradicate, especially in the setting of total joint arthroplasty. Although there is no clear consensus on treatment, guidelines are available for management of many of these pathogens.

  20. Phaeohyphomycoses, Emerging Opportunistic Diseases in Animals

    OpenAIRE

    Seyedmousavi, S.; Guillot, J; Hoog, de, G.S.

    2013-01-01

    Emerging fungal diseases due to black yeasts and relatives in domestic or wild animals and in invertebrates or cold- and warm-blooded vertebrates are continually being reported, either as novel pathogens or as familiar pathogens affecting new species of hosts. Different epidemiological situations can be distinguished, i.e., occurrence as single infections or as zoonoses, and infection may occur sporadically in otherwise healthy hosts. Such infections are found mostly in mammals but also in co...

  1. Immune response to fungal infections.

    Science.gov (United States)

    Blanco, Jose L; Garcia, Marta E

    2008-09-15

    The immune mechanisms of defence against fungal infections are numerous, and range from protective mechanisms that were present early in evolution (innate immunity) to sophisticated adaptive mechanisms that are induced specifically during infection and disease (adaptive immunity). The first-line innate mechanism is the presence of physical barriers in the form of skin and mucous membranes, which is complemented by cell membranes, cellular receptors and humoral factors. There has been a debate about the relative contribution of humoral and cellular immunity to host defence against fungal infections. For a long time it was considered that cell-mediated immunity (CMI) was important, but humoral immunity had little or no role. However, it is accepted now that CMI is the main mechanism of defence, but that certain types of antibody response are protective. In general, Th1-type CMI is required for clearance of a fungal infection, while Th2 immunity usually results in susceptibility to infection. Aspergillosis, which is a disease caused by the fungus Aspergillus, has been the subject of many studies, including details of the immune response. Attempts to relate aspergillosis to some form of immunosuppression in animals, as is the case with humans, have not been successful to date. The defence against Aspergillus is based on recognition of the pathogen, a rapidly deployed and highly effective innate effector phase, and a delayed but robust adaptive effector phase. Candida albicans, part of the normal microbial flora associated with mucous surfaces, can be present as congenital candidiasis or as acquired defects of cell-mediated immunity. Resistance to this yeast is associated with Th1 CMI, whereas Th2 immunity is associated with susceptibility to systemic infection. Dermatophytes produce skin alterations in humans and other animals, and the essential role of the CMI response is to destroy the fungi and produce an immunoprotective status against re-infection. The resolution

  2. ANIMAL PATHOGENS THAT MAY CAUSE HUMAN DISEASE THAT ORIGINATE FROM FARM OPERATIONS

    Science.gov (United States)

    The recent increase in concentrated animal feeding operations in the United States has caused renewed concern regarding the infectious diseases that may be passed from farm animals to humans via the environment. It is also known that more than 20 recent epidemics among humans cou...

  3. Tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in Mexico.

    Science.gov (United States)

    Sosa-Gutierrez, Carolina G; Vargas-Sandoval, Margarita; Torres, Javier; Gordillo-Pérez, Guadalupe

    2016-09-30

    Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1107 were collected by tick drag from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico. PMID:26726019

  4. Tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in Mexico.

    Science.gov (United States)

    Sosa-Gutierrez, Carolina G; Vargas-Sandoval, Margarita; Torres, Javier; Gordillo-Pérez, Guadalupe

    2016-09-30

    Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1107 were collected by tick drag from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico.

  5. Tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in Mexico

    Science.gov (United States)

    Vargas-Sandoval, Margarita; Torres, Javier

    2016-01-01

    Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1,107 ticks were collected by tick dragging from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico. PMID:26726019

  6. Complete Genome Sequence of Pathogenic Guinea Pig Cytomegalovirus from Salivary Gland Homogenates of Infected Animals

    OpenAIRE

    Yang, Dongmei; Tamburro, Kristen; Dittmer, Dirk; Cui, Xiaohong; McVoy, Michael A.; Hernandez-Alvarado, Nelmary; Schleiss, Mark R.

    2013-01-01

    The sequence of guinea pig cytomegalovirus (GPCMV) was determined by direct sequencing of salivary gland homogenates obtained following sustained, serial in vivo passage of pathogenic virus in guinea pigs. The 233,501-nucleotide salivary gland (SG) genome was noted to have 11 differences compared to the tissue culture-passaged virus, although no variations were noted in putative protein coding sequences.

  7. Evaluating conceptual modeling frameworks for farm scale groundwater pathogen transport associated with animal farming and municipal wastewater recharge

    Science.gov (United States)

    Cook, S. J.; Li, X.; Watanabe, N.; Atwill, R.; Puente, C. E.; Harter, T.

    2010-12-01

    Land applications to crops of diluted animal manure associated with concentrated animal feeding operations (CAFOs) and field discharges from municipal wastewater treatment plants are potential pathways for the contamination of shallow domestic and agricultural wells by pathogenic microorganisms. Sampling of soil and groundwater for the indicator and pathogenic microorganisms; Enterococcus spp., Escherichia coli, Campylobacter spp. and Salmonella was undertaken at two CAFOs in the San Joaquin Valley, California between 2006 and 2009. Observed concentrations are highly variable in both magnitude and frequency of detection and indicated no clear relationship to field applications or seasonal effects. To investigate if the observed variability in microorganism concentrations in groundwater could be attributed to aquifer heterogeneity, we developed multiple conceptual frameworks employing nonpoint source loading functions and groundwater transport models to simulate a shallow agricultural monitoring well catchment. We developed both, homogenous and heterogeneous aquifer representations, the latter using stochastic transition probability Markov chain representation. Also, we developd homogeneous and spatio-temporally heterogeneous loading models. Model sensitivity to conceptual frameworks, transport parameters, and spatio-temporal variations in diffuse pathogen loading at the water table was determined by comparing simulated frequency of pathogen detection with measured monitoring well breakthrough curves. Model results indicate that field scale aquifer heterogeneity cannot fully account for the variation in concentrations observed in shallow monitoring wells and that microorganism loading at the water table must also be highly heterogeneous. A two dimensional Neyman-Scott cluster process was found to provide the best representation of heterogeneity in recharge concentration and is conceptually consistent with the presence of low attenuation transport pathways in the

  8. Coronaviruses: emerging and re-emerging pathogens in humans and animals.

    Science.gov (United States)

    Lau, Susanna K P; Chan, Jasper F W

    2015-12-22

    The severe acute respiratory syndrome coronavirus (SARS-CoV) and recently emerged Middle East respiratory syndrome coronavirus (MERS-CoV) epidemics have proven the ability of coronaviruses to cross species barrier and emerge rapidly in humans. Other coronaviruses such as porcine epidemic diarrhea virus (PEDV) are also known to cause major disease epidemics in animals with huge economic loss. This special issue in Virology Journal aims to highlight the advances and key discoveries in the animal origin, viral evolution, epidemiology, diagnostics and pathogenesis of the emerging and re-emerging coronaviruses in both humans and animals.

  9. Plant based oral vaccines for human and animal pathogens – a new era of prophylaxis: current and future perspectives

    Directory of Open Access Journals (Sweden)

    Kuldeep Dhama

    Full Text Available Vaccination remains a high priority for animal disease prevention and control especially on account of rising antimicrobial resistant strains of pathogens and frightening increase in new emerging and reemerging pathogens. Traditional vaccines have limitation like residual virulence, need of extensive safety precautions, production difficulty and huge initial investments. Additionally, they are inefficient in producing a protective response at mucosal surfaces such as of lungs and intestinal tract, the actual sites where disease agents enter the body. Recent advances in plant molecular farming has resulted in genetic manipulations in plants to make them bioreactors for production of various recombinant proteins, by using infectious vectors or stable transgenic systems, which formulate the edible/oral vaccines. Such plant-based oral/edible vaccines have several advantages like they are functionally similar to conventional vaccines, demonstrate extended storage period in food grains, are heat-stable and does not require cold storage, eliminate need for expensive purification steps, are free from contaminating pathogens, can be produced in large scale in a time bound fashion and their delivery is easier with practical feasibility for large masses application. Additionally, these are also ideal for vaccination of animals and birds living in the wild areas thereby preventing many zoonoses. However, at this moment there are many practical challenges like degradation of vaccine antigen by enzymes of upper digestive tract, dosage regime, oral tolerance and the issues concerned to the use of genetically modified plant. In the near future the biomedical applications of these vaccines could become a common alternative to conventional vaccines, for which there is a great need to strengthen research and development activities in this promising area for protecting health of animals as well as of humans.

  10. Microsporidia Detection and Genotyping Study of Human Pathogenic E. bieneusi in Animals from Spain

    OpenAIRE

    Ana Luz Galván-Díaz; Angela Magnet; Soledad Fenoy; Nuno Henriques-Gil; María Haro; Francisco Ponce Gordo; Javier Millán; Guadalupe Miró; Carmen del Águila; Fernando Izquierdo

    2014-01-01

    Microsporidia are ubiquitous parasites infecting all animal phyla and we present evidence that supports their zoonotic potential. Fecal samples taken from domestic (cats and dogs), farm (pigs, rabbits and ostriches) and wild animals (foxes) from different provinces of Spain were evaluated for microsporidia infection by light microscopy and PCR. After Microsporidia species identification, E. bieneusi genotypes were additionally studied by sequence analysis of the ITS region. Eighty-five sample...

  11. FishPathogens.eu a new database in the research of aquatic animal diseases

    DEFF Research Database (Denmark)

    Jonstrup, Søren Peter; Gray, T.; Olesen, Niels Jørgen

    We live in a world where the amount of information available is enormous. In order to keep track of the available knowledge, databases are needed to collect, store, and sort it. Www.fishpathogens.eu is a database developed and maintained by the European Union Reference Laboratory for Fish Diseases....... The database was launched in June 2009 focusing on Viral Haemorrhagic Septicaemia Virus (VHSV), extended with Infectious Haemorrhagic Necrosis Virus (IHNV) in 2010, and is now being extended to include Spring Viraemia of Carp Virus (SVCV), Infectious Salmon Anemia Virus (ISAV), Betanodaviruses, and Koi Herpes...... Virus (KHV). The database design is based on freeware and could easily be implemented to include pathogens relevant for other species than fish. We present the database using the data on the different fish pathogens as example. However if some are interested in the platform we are happy to cooperate...

  12. Streptococcus suis, an Emerging Drug-Resistant Animal and Human Pathogen

    OpenAIRE

    Palmieri, Claudio; Varaldo, Pietro E.; Facinelli, Bruna

    2011-01-01

    Streptococcus suis, a major porcine pathogen, has been receiving growing attention not only for its role in severe and increasingly reported infections in humans, but also for its involvement in drug resistance. Recent studies and the analysis of sequenced genomes have been providing important insights into the S. suis resistome, and have resulted in the identification of resistance determinants for tetracyclines, macrolides, aminoglycosides, chloramphenicol, antifolate drugs, streptothricin,...

  13. [Investigation of pathogenic phenotypes and virulence determinants of food-borne Salmonella enterica strains in Caenorhabditis elegans animal model].

    Science.gov (United States)

    Aksoy, Deniz; Şen, Ece

    2015-10-01

    Salmonellosis, caused by non-typhoidal Salmonella enterica serovars with the consumption of contaminated food, is one of the leading food-borne disease that makes microbial food safety an important public health issue. This study was performed in order to determine the antibiotic resistance, serotyping, plasmid profiles and pathogenicity potentials of food-borne Salmonella isolates in Caenorhabditis elegans animal model system in Edirne province, located at Thrace region of Turkey. In this study, 32 Salmonella isolates, of which 26 belonged to Infantis, four to Enteritidis, one to Telaviv and one to Kentucky serovars, isolated from chicken carcasses were used. Antibiotic resistance profiles were determined by disc diffusion and broth microdilution methods. A new C.elegans nematode animal model system was used to determine the pathogenicity potential of the isolates. The antibiotic resistance profiles revealed that one (3.1%) isolate was resistant to gentamicin, two (6.2%) to ciprofloxacin, three (9.4%) to ampicillin, 18 (56.3%) to kanamycin, 19 (60.8%) to neomycin, 25 (78.1%) to tetracycline, 25 (78.1%) to trimethoprim, 26 (81.25%) to nalidixic acid, 27 (84.4%) to streptomycin and 32 (100%) to sulfonamide. All of the 32 strains were susceptible to chloramphenicol and ampicillin/sulbactam. High levels of resistance to streptomycin, nalidixic acid, tetracycline, trimethoprim, sulfonamide, kanamycin and neomycin was determined. According to the plasmid analysis, six isolates (18.75%) harboured 1-3 plasmids with sizes between 1.2 and 42.4 kb. In C.elegans nematode animal model system, the time (in days) required to kill 50% (TD50) of nematodes was calculated for each experimental group. TD50 values of the nematode group fed with S.Typhimurium ATCC 14028 that was used as the positive control and another group fed with E.coli OP50 as the negative control were 4.2 ± 0.5 days and 8.0 ± 0.02 days, respectively. TD50 of the groups fed with Salmonella isolates ranged

  14. 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

  15. 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.

  16. Prebiotic use in food animals to reduce foodborne pathogens and disease

    Science.gov (United States)

    As our understanding of the complexities of the gastrointestinal microbial ecosystem has grown in recent years, so has interest in utilizing the natural power contained within this ecosystem as a tool in our arsenal to improve both animal and human health. The diversity of the microbial population ...

  17. Pathogenic Fungus Microsporum canis Activates the NLRP3 Inflammasome

    OpenAIRE

    Mao, Liming; Zhang, Liping; Li, Hua; Chen, Wei; Wang, Hongbin; Wu, Shuxian; Guo, Caiqin; Lu, Ailing; Yang, Guiwen; An, Liguo; Abliz, Paride; Meng, Guangxun

    2014-01-01

    Microsporum canis is a pathogenic fungus with worldwide distribution that causes tinea capitis in animals and humans. M. canis also causes invasive infection in immunocompromised patients. To defy pathogenic fungal infection, the host innate immune system is the first line of defense. As an important arm of innate immunity, the inflammasomes are intracellular multiprotein complexes that control the activation of caspase-1, which cleaves proinflammatory cytokine pro-interleukin-1β (IL-1β) into...

  18. Fungal Meningitis

    Science.gov (United States)

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

  19. NUTRIENT COMPOSITION DEGRADATION OF DAPHNIA PULICARIA BY A HIGHLY PREVALENT CHYTRIDIOMYCETE FUNGAL PATHOGEN (POLYCARYUM LEAVE) DURING NATURALLY OCCURRING LAKE-WIDE EPIDEMICS.

    Science.gov (United States)

    Despite evidence illustrating that chytridiomycete fungal infection can be highly prevalent in Daphnia (>80%) and that infected individuals are preferentially consumed by fish, no studies have measured the nutritional consequences of using chytrid-infected Daphnia as a food sourc...

  20. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens

    OpenAIRE

    López Hernández, Yamilé; Yero, Daniel; Pinos-Rodríguez, Juan M.; Gibert, Isidre

    2015-01-01

    Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the vir...

  1. Development of disease preventive method using radiated pathogenic microorganisms, cell lines and animals

    International Nuclear Information System (INIS)

    The effects of radiation were investigated on pathogenic plasmid aiming at a development of a method to induce mutagenesis in plasmid DNA by radiation. To construct an experimental system which allows to detect a plasmid-segregated cell, kanamycin-resistant casette was inserted into pX02, a capsule plasmid in Bacillus anthracis to produce acpA:: Kmr by homologous recombination. This plasmid is thought available for analyzing the rate of plasmid segregation caused by radiation. Next, developments of detection and determination methods for various cytokines were attempted by RT-PCR method with an aim to investigate the expression changes of cytokine mRNA in calf immunocytes by radiation. In calf peripheral monocytes and alveolar macrophages, expressions of cytokine mRNAs such as IL-4, IFNα and GM-CSF mRNA as well as IL-1α, IL-1β, IL-2 and IL-6 were detected by RT-PCR method. (M.N.)

  2. Microsporidia detection and genotyping study of human pathogenic E. bieneusi in animals from Spain.

    Directory of Open Access Journals (Sweden)

    Ana Luz Galván-Díaz

    Full Text Available Microsporidia are ubiquitous parasites infecting all animal phyla and we present evidence that supports their zoonotic potential. Fecal samples taken from domestic (cats and dogs, farm (pigs, rabbits and ostriches and wild animals (foxes from different provinces of Spain were evaluated for microsporidia infection by light microscopy and PCR. After Microsporidia species identification, E. bieneusi genotypes were additionally studied by sequence analysis of the ITS region. Eighty-five samples out of 159 exhibited structures that were compatible with microsporidia spores by Webeŕs stain with 37 of them being confirmed by PCR. Microsporidia species identified included E. bieneusi, E. intestinalis and A. algerae. We report the first diagnosis of E. intestinalis and E. bieneusi in ostriches and A. algerae in pigs. We also provide new information on the molecular characterization of E. bieneusi isolates both in rabbits and ostriches. All of the E. bieneusi genotypes identified belonged to the zoonotic group of genotypes (Group I including genotypes A (dogs, I (pigs, D (rabbits and foxes and type IV (ostriches. Our results demonstrate that microsporidia are present in domestic, farm and wild animals in Spain, corroborating their potential role as a source of human infection and environmental contamination.

  3. Molecular survey of tick-borne pathogens in Ixodid ticks collected from hunted wild animals in Tuscany, Italy

    Institute of Scientific and Technical Information of China (English)

    Valentina; Virginia; Ebani; Fabrizio; Bertelloni; Barbara; Turchi; Dario; Filogari; Domenico; Cerri

    2015-01-01

    Objective: To determine the prevalence of zoonotic tick-borne bacteria in feeding ticks removed from hunted wild animals. Methods: PCR was executed on DNA extracted from 77 tick pools to detect Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato, Coxiella burnetii and Rickettsia spp. Results: A total of 432 ticks were collected: 30(6.94%) Haemaphysalis punctata, 72(16.7%) Dermacentor marginatus and 330(76.38%) Ixodes ricinus. For each animal one or two pools of 3 ticks of the same species was constituted. Seventy-seven tick pools were examined by PCR: 58(75.32%) resulted infected and among them 14(18.18%) showed co-infections. In particular, 29(37.66%) pools were positive for Bartonella spp., 23(29.87%) for Anaplasma phagocytophilum, 16(20.78%) for Rickettsia spp., and 5(6.49%) for Borrelia burgdorferi s.l. All samples were negative for Coxiella burnetii. Conclusions: The results demonstrate the presence of several zoonotic tick-borne pathogens in the studied area, and underline the risk of exposure to infections for hunters not only during the outdoor activity, but also when they manipulate hunted animals infested by infected ticks.

  4. An improved method for RNA extraction from urediniospores of and wheat leaves infected by an obligate fungal pathogen, Puccinia striiformis f. sp.tritici

    Institute of Scientific and Technical Information of China (English)

    MA Li-Jie; QIAO Jia-xing; KONG Xin-yu; WANG Jun-juan; XU Xiang-ming; HU Xiao-ping

    2016-01-01

    Stripe rust, caused byPuccinia striformis f. sp.tritici, is an important wheat disease in China, seriously threatening wheat production. Understanding the winter survival of the fungus is a key for predicting the spring epidemics of the disease, which determines the crop loss. Estimation ofP. striformisf. sp. triticiwinter survival requires processing a large number of samples for sensitive detection of the pathogen in wheat leaf tissue using real-time quantitative reverse transcription PCR (qRT-PCR). A bottleneck for the analysis is the acquisition of a good yield of high quality RNA suitable for qRT-PCR to distinguish dead and alive fungal hyphae inside leaves. Although several methods have been described in the literatures and commercial kits are available for RNA extraction, these methods are mostly too complicated, expensive and inefifcient. Thus, we modiifed three previously reported RNA extraction methods with common and low-cost reagents (LiCl, SDS and NaCl) to solve the problems and selected the best to obtain high quality and quantity RNA for use in qRT-PCR. In the three improved methods, the NaCl method was proven to be the best for extracting RNA from urediniospores of and wheat leaves infected byP. striformisf. sp. tritici, although the modiifed LiCl and SDS methods also increased yield of RNA compared to the previous methods. The improved NaCl method has the folowing advantages: 1) Complete transfer of urediniospores ofP. striformis f. sp. tritici from the mortar and pestle can ensure the initial amount of RNA for the qRT-PCR analysis; 2) the use of low-cost NaCl to replace more expensive Trizol can reduce the cost; 3) the yield and quality of RNA can be increased;4) the improved method is more suitable for a large number and high quantity of samples from ifelds. Using the improved NaCl method, the amount of RNA was increased three times from urediniospores ofP. striformis f. sp. triticicompared from the extraction kit. Approximately, 10.11 μg total

  5. Genetic animal models to decipher the pathogenic effects of vitamin B12 and folate deficiency.

    Science.gov (United States)

    Peng, Lu; Dreumont, Natacha; Coelho, David; Guéant, Jean-Louis; Arnold, Carole

    2016-07-01

    Vitamin B12 and folate are essential micronutrients that provide methyl groups for cellular methylations through the so-called one-carbon metabolism. Deficits in the absorption and transport or defects of the enzymes can lead to human pathogenesis comprising hematologic, neural, gastrointestinal, hepatic, renal, cardiovascular and developmental manifestations. One-carbon metabolism is a complex, multistep and multi-organ metabolism, and the understanding of the mechanisms at work have benefited from human inborn errors and population studies, as well as from nutritional animal models. Since 15 years, a wide variety of genetically engineered mice has been developed and has proved to be useful to decipher the underlying mechanisms. These genetically engineered mice target all the genes that are important for the intestinal absorption, cellular transport and metabolism of vitamin B12 and folate, which are detailed in this article. In conclusion, these mouse models represent valuable experimental paradigms for human pathogenesis. Since no animal model recapitulates the full spectrum of a human disease, researchers have to choose the one that is the most relevant for their specific needs, and this review may help in this respect. PMID:27178438

  6. Animal models of Huntington's disease: implications in uncovering pathogenic mechanisms and developing therapies

    Institute of Scientific and Technical Information of China (English)

    Lin-hui WANG; Zheng-hong QIN

    2006-01-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder, which is caused by an abnormal expansion of Cytosine Adenine Guanine (CAG) trinucleotide repeat in the gene making huntingtin (Htt). Despite intensive research efforts devoted to investigate molecular mechanisms of pathogenesis, effective therapy for this devastating disease is still not available at present. The development of various animal models of HD has offered alternative approaches in the study of HD molecular pathology. Many HD models, including chemical-induced models and genetic models, mimic some aspects of HD symptoms and pathology. To date, however, there is no ideal model which replicates all of the essential features of neuropathology and progressive motor and cognitive impairments of human HD. As a result, our understanding of molecular mechanisms of pathogenesis in HD is still limited. A new model is needed in order to uncover the pathogenesis and to develop novel therapies for HD. In this review we discussed usefulness and limitations of various animal and cellular models of HD in uncovering molecular mechanisms of pathogenesis and developing novel therapies for HD.

  7. Development of disease prevention method using radiation irradiated pathogenic microorganisms, cells and animals

    International Nuclear Information System (INIS)

    Enhancement of the abilities of specific and non-specific disease prevention through the regulation of cytokine production has been paid attention in clinical and veterinary fields. Bovine monocytes isolated from the peripheral blood were exposed to X-ray at 0.1-10 Gy and cultured in the conditions with and without LPS stimulation to investigate the radiation effects at a low level on the expression of cytokine mRNA. The expressions of IL-1 and TNFα were significantly increased in the bovine peripheral monocytes by the exposure to X-ray. If it become possible to control the induction of IL-1 and TNFα by low level X-ray, the radiation would be used as a new biophylaxis method. Then, an investigation was made on the radiation effects on pathogenic plasmid such as capsule plasmid of Bacillus anthracis. A system able to detect a one-base change in base sequence was designed using capE gene, which has been known to mediate the positive regulation of capsule expression. Not only phenotypic changes but also little changes in the phenotype caused by gene mutation became detectable. Thus, it became possible by this detection method to make analysis of radiation induced gene mutation in a plasmid and its frequency. (M.N.)

  8. A mathematical framework for estimating pathogen transmission fitness and inoculum size using data from a competitive mixtures animal model.

    Directory of Open Access Journals (Sweden)

    James M McCaw

    2011-04-01

    Full Text Available We present a method to measure the relative transmissibility ("transmission fitness" of one strain of a pathogen compared to another. The model is applied to data from "competitive mixtures" experiments in which animals are co-infected with a mixture of two strains. We observe the mixture in each animal over time and over multiple generations of transmission. We use data from influenza experiments in ferrets to demonstrate the approach. Assessment of the relative transmissibility between two strains of influenza is important in at least three contexts: 1 Within the human population antigenically novel strains of influenza arise and compete for susceptible hosts. 2 During a pandemic event, a novel sub-type of influenza competes with the existing seasonal strain(s. The unfolding epidemiological dynamics are dependent upon both the population's susceptibility profile and the inherent transmissibility of the novel strain compared to the existing strain(s. 3 Neuraminidase inhibitors (NAIs, while providing significant potential to reduce transmission of influenza, exert selective pressure on the virus and so promote the emergence of drug-resistant strains. Any adverse outcome due to selection and subsequent spread of an NAI-resistant strain is exquisitely dependent upon the transmission fitness of that strain. Measurement of the transmission fitness of two competing strains of influenza is thus of critical importance in determining the likely time-course and epidemiology of an influenza outbreak, or the potential impact of an intervention measure such as NAI distribution. The mathematical framework introduced here also provides an estimate for the size of the transmitted inoculum. We demonstrate the framework's behaviour using data from ferret transmission studies, and through simulation suggest how to optimise experimental design for assessment of transmissibility. The method introduced here for assessment of mixed transmission events has

  9. 马铃薯连作田土壤中主要病原真菌的种群动态变化规律%Population dynamics of main fungal pathogens in soil of continuously cropped potato

    Institute of Scientific and Technical Information of China (English)

    李继平; 李敏权; 惠娜娜; 王立; 马永强; 漆永红

    2013-01-01

    作物长期连作后出现土壤肥力不平衡,病原物种类及其数量不断累积,表现出严重的连作障碍.连作障碍影响马铃薯的产量和品质,已成为马铃薯产业发展的主要限制因素,土壤微生物作为连作障碍的主要因素之一,研究土壤中病原菌种群动态变化具有重要的意义.为了深入研究土传病原真菌与马铃薯连作的关系,探明马铃薯连作障碍的机理,采用稀释平板法和残渣分离法研究了马铃薯连作对土壤病原真菌种群动态变化的影响.结果表明,甘肃省定西市渭源县会川镇半阴坡村马铃薯的主要土传病原真菌为镰孢菌、轮枝菌和立枯丝核菌;3种病菌主要分布于0~10 cm土壤层,10~20和20~30 cm土壤层则较少,其中0~10 cm土壤层中每克土壤中的菌落数均随连作年限的增加而增加,镰孢菌(Fusarium spp.)为3 900,900,2 100和5 900个/g土,轮枝菌(Verticillium spp.)为200,400,600和1 600个/g土,立枯丝核菌(Rhizoctonia solani)为7.80,9.58,20.60和22.40个/10 g土;建议通过翻耕或药剂处理重点防治表层土传病菌.%Soil fertility imbalance,the pathogenic species and numbers accumulation were becoming obvious after a long term continous cropping of crops,which showed continuous cropping obstacle.Continuous cropping obstacle was one of the main restriction factors in potato industry.In order to understand the relationship between soil-borne fungal pathogens and potato continuous cropping,and explore the mechanisms of potato's continuous cropping obstacle,population dynamics of main fungal pathogens in soil was conducted by dilution plate and debris separation methods.The main fungi groups were Fusarium spp.,Verticillium spp.and Rhizoctonia solani in soil of Huichuan in Gansu province,three fungal pathogens were maily distributed in 0-10 cm soil,with lessly in 10-20 cm and 20-30 cm soil.And the increasing year of potato's continuous cropping,the numbers of fungal pathogens in 0

  10. Animals

    International Nuclear Information System (INIS)

    The radionuclides of most concern with respect to contamination of animals after a nuclear accident are radioiodine, radiocaesium and radiostrontium (ICRP 30, 1979). Of the other significant anthropogenic radionuclides likely to be released in most accidents, only small proportions of that ingested will be absorbed in an animals gut, and the main animal products, milk and meat, will not normally be contaminated to a significant extent. Animal products will mostly be contaminated as a result of ingestion of contaminated feed and possibly, but to a much lesser extent, from inhalation (for radioiodine only). Direct external contamination of animals is of little or no consequence in human food production. Radioiodine and radiostrontium are important with respect to contamination of milk; radiocaesium contaminates both milk and meat. The physical and chemical form of a radionuclide can influence its absorption in the animal gut. For example, following the Chernobyl accident radiocaesium incorporated into vegetation by root uptake was more readily absorbed than that associated with the original deposit. The transfer of radiocaesium and radiostrontium to animals will be presented both as transfer coefficients and aggregated transfer coefficients. For most animal meat products, only radiocaesium is important as other radionuclides do not significantly contaminate muscle. Farm animal products are the most important foodstuff determining radiocaesium intake by the average consumer in the Nordic countries. The major potential source of radioiodine and radiostrontium to humans is milk and milk products. Of the different species, the smaller animals have the highest transfer of radiocaesium from fodder to meat and milk. (EG)

  11. Free-living amoebae as opportunistic and non-opportunistic pathogens of humans and animals.

    Science.gov (United States)

    Schuster, Frederick L; Visvesvara, Govinda S

    2004-08-01

    Knowledge that free-living amoebae are capable of causing human disease dates back some 50 years, prior to which time they were regarded as harmless soil organisms or, at most, commensals of mammals. First Naegleria fowleri, then Acanthamoeba spp. and Balamuthia mandrillaris, and finally Sappinia diploidea have been recognised as etiologic agents of encephalitis; Acanthamoeba spp. are also responsible for amoebic keratitis. Some of the infections are opportunistic, occurring mainly in immunocompromised hosts (Acanthamoeba and Balamuthia encephalitides), while others are non-opportunistic (Acanthamoeba keratitis, Naegleria meningoencephalitis, and cases of Balamuthia encephalitis occurring in immunocompetent humans). The amoebae have a cosmopolitan distribution in soil and water, providing multiple opportunities for contacts with humans and animals, as evidenced by antibody titers in surveyed human populations. Although, the numbers of infections caused by these amoebae are low in comparison to other protozoal parasitoses (trypanosomiasis, toxoplasmosis, malaria, etc.), the difficulty in diagnosing them, the challenge of finding optimal antimicrobial treatments and the morbidity and relatively high mortality associated with, in particular, the encephalitides have been a cause for concern for clinical and laboratory personnel and parasitologists. This review presents information about the individual amoebae: their morphologies and life-cycles, laboratory cultivation, ecology, epidemiology, nature of the infections and appropriate antimicrobial therapies, the immune response, and molecular diagnostic procedures that have been developed for identification of the amoebae in the environment and in clinical specimens.

  12. A Flexible Spatial Framework for Modeling Spread of Pathogens in Animals with Biosurveillance and Disease Control Applications

    Directory of Open Access Journals (Sweden)

    Montiago X. LaBute

    2014-05-01

    Full Text Available Biosurveillance activities focus on acquiring and analyzing epidemiological and biological data to interpret unfolding events and predict outcomes in infectious disease outbreaks. We describe a mathematical modeling framework based on geographically aligned data sources and with appropriate flexibility that partitions the modeling of disease spread into two distinct but coupled levels. A top-level stochastic simulation is defined on a network with nodes representing user-configurable geospatial “patches”. Intra-patch disease spread is treated with differential equations that assume uniform mixing within the patch. We use U.S. county-level aggregated data on animal populations and parameters from the literature to simulate epidemic spread of two strikingly different animal diseases agents: foot-and-mouth disease and highly pathogenic avian influenza. Results demonstrate the capability of this framework to leverage low-fidelity data while producing meaningful output to inform biosurveillance and disease control measures. For example, we show that the possible magnitude of an outbreak is sensitive to the starting location of the outbreak, highlighting the strong geographic dependence of livestock and poultry infectious disease epidemics and the usefulness of effective biosurveillance policy. The ability to compare different diseases and host populations across the geographic landscape is important for decision support applications and for assessing the impact of surveillance, detection, and mitigation protocols.

  13. Regulation of the fungal secretome.

    Science.gov (United States)

    McCotter, Sean W; Horianopoulos, Linda C; Kronstad, James W

    2016-08-01

    The ability of countless representatives of the Kingdom Fungi to adapt to and proliferate in diverse environments is facilitated by regulation of their secretomes to respond to changes in environmental conditions and to mediate interactions with other organisms. Secretome changes often fulfill common functions of nutrient acquisition, facilitation of host/symbiont interactions, cell wall modification, and optimization of the enzyme suite to adapt to new environmental resources. In this review, we expand on our recent work on signaling and the secretome in the pathogenic fungus Cryptococcus neoformans to consider a range of selected examples of regulation of fungal secretomes. These examples include the impact of carbon source and aspects of the response to plant and animal hosts. Additionally, the influence of key protein kinases (e.g., Pka1, Snf1) and transcription factors (e.g., Rim101/PacC) is highlighted to illustrate some underlying regulatory factors influencing the secretome. Although there is a wealth of information about fungal secretomes from both experimentation and genome sequence mining, there are also major gaps in our knowledge about the complete composition of fungal secretomes and mechanisms of dynamic change. For example, a more comprehensive understanding of the composition and regulation of the secretome will require consideration of the emerging roles of unconventional secretion and extracellular vesicles in delivering proteins outside the cell. Overall, changes in the secretome are well documented in diverse fungi and the underlying mechanisms are currently under investigation; however, there remain unknown steps in the regulation of secretory pathways and gaps in understanding the regulation of unconventional secretion, which warrant further research. PMID:26879194

  14. Social and Economic Aspects of the Transmission of Pathogenic Bacteria between Wildlife and Food Animals: A Thematic Analysis of Published Research Knowledge.

    Science.gov (United States)

    Fournier, A; Young, I; Rajić, A; Greig, J; LeJeune, J

    2015-09-01

    Wildlife is a known reservoir of pathogenic bacteria, including Mycobacterium bovis and Brucella spp. Transmission of these pathogens between wildlife and food animals can lead to damaging impacts on the agri-food industry and public health. Several international case studies have highlighted the complex and cross-sectoral challenges involved in preventing and managing these potential transmission risks. The objective of our study was to develop a better understanding of the socio-economic aspects of the transmission of pathogenic bacteria between wildlife and food animals to support more effective and sustainable risk mitigation strategies. We conducted qualitative thematic analysis on a purposive sample of 30/141 articles identified in a complementary scoping review of the literature in this area and identified two key themes. The first related to the framing of this issue as a 'wicked problem' that depends on a complex interaction of social factors and risk perceptions, governance and public policy, and economic implications. The second theme consisted of promising approaches and strategies to prevent and mitigate the potential risks from transmission of pathogenic bacteria between wildlife and food animals. These included participatory, collaborative and multidisciplinary decision-making approaches and the proactive incorporation of credible scientific evidence and local contextual factors into solutions. The integration of these approaches to address 'wicked problems' in this field may assist stakeholders and decision-makers in improving the acceptability and sustainability of future strategies to reduce the transmission of pathogenic bacteria between wildlife and food animals.

  15. Controlling fungal foliar pathogen e.g. Venturia inaequalis, Blumeriella jaapi, in plants involves treating plants with a composition comprising an extract from Yucca as an antifungal agent

    DEFF Research Database (Denmark)

    2007-01-01

    The invention relates to control of fungal foliar diseases in plants, preferaby Rosaceae, such as apple scab (Venturia inaequalis), pear scab (Venturia pirina), brown spot (Stemphylium vesicarium) and powdery mildew (Podosphaera leucotricha) by treatment of plant with an extract of Yucca species...

  16. Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO2 assimilation and growth in Douglas-fir

    Science.gov (United States)

    Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible...

  17. Fungal sensing of host environment.

    Science.gov (United States)

    Braunsdorf, C; Mailänder-Sánchez, D; Schaller, M

    2016-09-01

    To survive inside a host, fungi have to adapt to a changing and often hostile environment and therefore need the ability to recognize what is going on around them. To adapt to different host niches, they need to sense external conditions such as temperature, pH and to recognize specific host factors. The ability to respond to physiological changes inside the host, independent of being in a commensal, pathogenic or even symbiotic context, implicates mechanisms for sensing of specific host factors. Because the cell wall is constantly in contact with the surrounding, fungi express receptors on the surface of their cell wall, such as pheromone receptors, which have important roles, besides mediating chemotropism for mating. We are not restricting the discussion to the human host because the receptors and mechanisms used by different fungal species to sense their environment are often similar even for plant pathogens. Furthermore, the natural habitat of opportunistic pathogenic fungi with the potential to cause infection in a human host is in soil and on plants. While the hosts' mechanisms of sensing fungal pathogens have been addressed in the literature, the focus of this review is to fill the gap, giving an overview on fungal sensing of a host-(ile) environment. Expanding our knowledge on host-fungal interactions is extremely important to prevent and treat diseases of pathogenic fungi, which are important issues in human health and agriculture but also to understand the delicate balance of fungal symbionts in our ecosystem. PMID:27155351

  18. Animals

    Energy Technology Data Exchange (ETDEWEB)

    Skuterud, L.; Strand, P. [Norwegian Radiation Protection Authority (Norway); Howard, B.J. [Inst. of Terrestrial Ecology (United Kingdom)

    1997-10-01

    The radionuclides of most concern with respect to contamination of animals after a nuclear accident are radioiodine, radiocaesium and radiostrontium (ICRP 30, 1979). Of the other significant anthropogenic radionuclides likely to be released in most accidents, only small proportions of that ingested will be absorbed in an animals gut, and the main animal products, milk and meat, will not normally be contaminated to a significant extent. Animal products will mostly be contaminated as a result of ingestion of contaminated feed and possibly, but to a much lesser extent, from inhalation (for radioiodine only). Direct external contamination of animals is of little or no consequence in human food production. Radioiodine and radiostrontium are important with respect to contamination of milk; radiocaesium contaminates both milk and meat. The physical and chemical form of a radionuclide can influence its absorption in the animal gut. For example, following the Chernobyl accident radiocaesium incorporated into vegetation by root uptake was more readily absorbed than that associated with the original deposit. The transfer of radiocaesium and radiostrontium to animals will be presented both as transfer coefficients and aggregated transfer coefficients. For most animal meat products, only radiocaesium is important as other radionuclides do not significantly contaminate muscle. Farm animal products are the most important foodstuff determining radiocaesium intake by the average consumer in the Nordic countries. The major potential source of radioiodine and radiostrontium to humans is milk and milk products. Of the different species, the smaller animals have the highest transfer of radiocaesium from fodder to meat and milk. (EG). 68 refs.

  19. Modulation of host-cell MAPkinase signaling during fungal infection

    OpenAIRE

    Nir Osherov

    2015-01-01

    Fungal infections contribute substantially to human suffering and mortality. The interaction between fungal pathogens and their host involves the invasion and penetration of the surface epithelium, activation of cells of the innate immune system and the generation of an effective response to block infection. Numerous host-cell signaling pathways are activated during fungal infection. This review will focus on the main fungal pathogens Aspergillus fumigatus, Candida albicans and Cryptococcus n...

  20. 动物源性病原细菌的危害、监测与控制%Animal Origin Pathogenic Bacteria:Hazard,Surveillance and Control

    Institute of Scientific and Technical Information of China (English)

    王君玮

    2015-01-01

    Animal origin pathogenic bacteria are those isolated from animal samples,damaging animals and human by bacteria invasion or ingestion of their toxin. Not only can it bring economic loss and biosafety problem by causing animal diseases,but also do harm to consumers. This paper briefly introduced the main pathogenic bacteria species that impact animal health and its product safety,as well as their harm to both animals and human. Furthermore,new advance on these bacteria surveillance status was analyzed both at home and abroad. Suggestions on their control were proposed in combination with risk surveillance of pathogenic bacteria.%动物源性病原细菌,不仅引起动物发病带来经济损失和生物安全问题,而且通过污染动物源性产品,给消费者带来致病性危害。本文梳理了影响动物健康和动物源性产品安全的主要病原细菌种类及其危害,对此分析了目前国际、国内对该类病原细菌的监测管理状况,并提出了控制建议。

  1. Classification and Clinical Distribution of Nosocomial Pathogenic Bacteria in Invasive Fungal Infection%医院侵袭性真菌感染的菌种分类及临床分布

    Institute of Scientific and Technical Information of China (English)

    彭云; 刘长武; 段小华; 姜贻海

    2011-01-01

    目的 了解医院内侵袭性真菌感染的流行病学特点,为减少真菌感染提供实验依据.方法 回顾性分析2006-2009年住院患者真菌培养阳性的菌种分类、标本种类、疾病种类、科室分布等.结果 4年间共检出侵袭性真菌1 945株,总的检出率为17.0%,2006-2009年真菌的检出率分别为14.6%、15.7%、16.8%和21.2%.真菌种类以念珠菌属为主,占92.4%,以白色念珠菌居多,占60.5%;丝状菌占7.6%.检出的1 945株真菌主要分离自痰、尿和大便标本.真菌感染患者主要来自呼吸科、心血管内科、传染科、神经内科和ICU等科室.结论 侵袭性真菌的检出率逐年升高,白色念珠菌仍是医院内侵袭性真菌感染的主要病原菌,非白色念珠菌和毛霉菌属引起的感染不断增加.%Objective To understand the epidemiological features of invasive fungal infection, and to provide the experimental evidence for reducing fungal infections.Methods According to the distribution of fungal species, specimen type, disease category, and department distribution, the positive cases of fungal cultures in the People' s Hospital of Wugang from 2006 to 2009 were retrospectively analyzed.Results Totally 1,945 strains of invasive fungi were detected during a four-year period and the total detection rate was 17.0%.The detection rates of fungi from 2006 to 2009 were 14.6%,15.7 %, 16.8 % and 21.2 %, respectively.The main pathogen of invasive fungal infections was Candida spp.(92.4 % ) and Candida albicans was the most frequent organism, accounting for 60.5 % of all the isolates.Filamentous fungi accounted for 7.6%.1,945 strains of fungi were isolated mainly from sputtrn, urine and stool specimens.The patients with invasive fungal infections were mainly from respiratory department, cardiovascular medicine department, infectious diseases department,neurology department, and ICU.Conclusions The detection rate of invasive fungi increased year by year, and

  2. Human Skin Fungal Diversity

    OpenAIRE

    Findley, Keisha; OH, JULIA; Yang, Joy; Conlan, Sean; Deming, Clayton; Meyer, Jennifer A.; Schoenfeld, Deborah; Nomicos, Effie; Park, Morgan; ,; Kong, Heidi H.; Segre, Julia A

    2013-01-01

    Traditional culture-based methods have incompletely defined the etiology of common recalcitrant human fungal skin diseases including athlete’s foot and toenail infections. Skin protects humans from invasion by pathogenic microorganisms, while providing a home for diverse commensal microbiota 1 . Bacterial genomic sequence data have generated novel hypotheses about species and community structures underlying human disorders 2,3,4 . However, microbial diversity is not limited to bacteria; micro...

  3. Protective immune responses to fungal infections.

    Science.gov (United States)

    Rivera, A

    2014-09-01

    The incidence of fungal infections has been on the rise over several decades. Fungal infections threaten animals, plants and humans alike and are thus of significant concern to scientists across disciplines. Over the last decade, significant advances on fungal immunology have lead to a better understanding of important mechanisms of host protection against fungi. In this article, I review recent advances of relevant mechanisms of immune-mediated protection to fungal infections.

  4. Complete Genome Sequence of the Animal Pathogen Listeria ivanovii, Which Provides Insights into Host Specificities and Evolution of the Genus Listeria

    OpenAIRE

    Buchrieser, C; Rusniok, C.; Garrido, P; HAIN, T; M. Scortti; Lampidis, R.; Kaerst, U.; Chakraborty, T; Cossart, P.; Kreft, J; Vazquez-Boland, J A; Goebel, W.; Glaser, P

    2011-01-01

    We report the complete and annotated genome sequence of the animal pathogenListeria ivanoviisubsp.ivanoviistrain PAM 55 (serotype 5), isolated in 1997 in Spain from an outbreak of abortion in sheep. The sequence and its analysis are available at an interactive genome browser at the Institut Pasteur (http://genolist.pasteur.fr/LivaList/).

  5. The Perceived Value of Passive Animal Health Surveillance: The Case of Highly Pathogenic Avian Influenza in Vietnam.

    Science.gov (United States)

    Delabouglise, A; Antoine-Moussiaux, N; Phan, T D; Dao, D C; Nguyen, T T; Truong, B D; Nguyen, X N T; Vu, T D; Nguyen, K V; Le, H T; Salem, G; Peyre, M

    2016-03-01

    Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non-monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non-monetary benefit) which was mainly obtained from other private actors and media. PMID:26146982

  6. The Perceived Value of Passive Animal Health Surveillance: The Case of Highly Pathogenic Avian Influenza in Vietnam.

    Science.gov (United States)

    Delabouglise, A; Antoine-Moussiaux, N; Phan, T D; Dao, D C; Nguyen, T T; Truong, B D; Nguyen, X N T; Vu, T D; Nguyen, K V; Le, H T; Salem, G; Peyre, M

    2016-03-01

    Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non-monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non-monetary benefit) which was mainly obtained from other private actors and media.

  7. The influence of the fungal pathogen Mycocentrosporae acerina on the proteome and polyacetylenes and 6-methoxymellein in organic and conventionally cultivated carrots (Daucus carota) during post harvest storage

    DEFF Research Database (Denmark)

    Louarn, Sébastien Jean Yves; Nawrocki, Arkadiusz; Edelenbos, Merete;

    2012-01-01

    Many carrots are discarded during post harvest cold storage due to development of fungal infections, caused by, e.g., Mycocentrospora acerina (liquorice rot). We compared the susceptibility of carrots grown under conventional and organic agricultural practices. In one year, organically cultivated...... carrots showed 3× to 7× more symptoms than conventionally cultivated, when studying naturally occurring disease at 4 and 6 months, respectively. On the other hand, we have developed a bioassay for infection studies of M. acerina on carrots and observed that organic roots were more susceptible after one...... metabolism. This combined metabolic and proteomic study indicates that roots respond to fungal infection through altered metabolism: simultaneous induction of 6-methoxymellein and synthesis of defence related proteins....

  8. Pan-European resistance monitoring programmes encompassing food-borne bacteria and target pathogens of food-producing and companion animals.

    Science.gov (United States)

    de Jong, A; Thomas, V; Klein, U; Marion, H; Moyaert, H; Simjee, S; Vallé, M

    2013-05-01

    Antimicrobial resistance is a concern both for animal and human health. Veterinary programmes monitoring resistance of animal and zoonotic pathogens are therefore essential. Various European countries have implemented national surveillance programmes, particularly for zoonotic and commensal bacteria, and the European Food Safety Authority (EFSA) is compiling the data. However, harmonisation is identified as a weakness and an essential need in order to compare data across countries. Comparisons of resistance monitoring data among national programmes are hampered by differences between programmes, such as sampling and testing methodology, and different epidemiological cut-off values or clinical breakpoints. Moreover, only very few valid data are available regarding target pathogens both of farm and companion animals. The European Animal Health Study Centre (CEESA) attempts to fill these gaps. The resistance monitoring programmes of CEESA have been a collaboration of veterinary pharmaceutical companies for over a decade and include two different projects: the European Antimicrobial Susceptibility Surveillance in Animals (EASSA) programme, which collects food-borne bacteria at slaughter from healthy animals, and the pathogen programmes that collect first-intention target pathogens from acutely diseased animals. The latter comprises three subprogrammes: VetPath; MycoPath; and ComPath. All CEESA projects include uniform sample collection and bacterial identification to species level in various European Union (EU) member states. A central laboratory conducts quantitative susceptibility testing to antimicrobial agents either important in human medicine or commonly used in veterinary medicine. This 'methodology harmonisation' allows easy comparisons among EU member states and makes the CEESA programmes invaluable to address food safety and antibiotic efficacy.

  9. One time intranasal vaccination with a modified vaccinia Tiantan strain MVTT(ZCI) protects animals against pathogenic viral challenge.

    Science.gov (United States)

    Yu, Wenbo; Fang, Qing; Zhu, Weijun; Wang, Haibo; Tien, Po; Zhang, Linqi; Chen, Zhiwei

    2010-02-25

    To combat variola virus in bioterrorist attacks, it is desirable to develop a noninvasive vaccine. Based on the vaccinia Tiantan (VTT) strain, which was historically used to eradicate the smallpox in China, we generated a modified VTT (MVTT(ZCI)) by removing the hemagglutinin gene and an 11,944bp genomic region from HindIII fragment C2L to F3L. MVTT(ZCI) was characterized for its host cell range in vitro and preclinical safety and efficacy profiles in mice. Despite replication-competency in some cell lines, unlike VTT, MVTT(ZCI) did not cause death after intracranial injection or body weight loss after intranasal inoculation. MVTT(ZCI) did not replicate in mouse brain and was safe in immunodeficient mice. MVTT(ZCI) induced neutralizing antibodies via the intranasal route of immunization. One time intranasal immunization protected animals from the challenge of the pathogenic vaccinia WR strain. This study established proof-of-concept that the attenuated replicating MVTT(ZCI) may serve as a safe noninvasive smallpox vaccine candidate.

  10. Nucleic-acid testing, new platforms and nanotechnology for point-of-decision diagnosis of animal pathogens.

    Science.gov (United States)

    Teles, Fernando; Fonseca, Luís

    2015-01-01

    Accurate disease diagnosis in animals is crucial for animal well-being but also for preventing zoonosis transmission to humans. In particular, livestock diseases may constitute severe threats to humans due to the particularly high physical contact and exposure and, also, be the cause of important economic losses, even in non-endemic countries, where they often arise in the form of rapid and devastating epidemics. Rapid diagnostic tests have been used for a long time in field situations, particularly during outbreaks. However, they mostly rely on serological approaches, which may confirm the exposure to a particular pathogen but may be inappropriate for point-of-decision (point-of-care) settings when emergency responses supported on early and accurate diagnosis are required. Moreover, they often exhibit modest sensitivity and hence significantly depend on later result confirmation in central or reference laboratories. The impressive advances observed in recent years in materials sciences and in nanotechnology, as well as in nucleic-acid synthesis and engineering, have led to an outburst of new in-the-bench and prototype tests for nucleic-acid testing towards point-of-care diagnosis of genetic and infectious diseases. Manufacturing, commercial, regulatory, and technical nature issues for field applicability more likely have hindered their wider entrance into veterinary medicine and practice than have fundamental science gaps. This chapter begins by outlining the current situation, requirements, difficulties, and perspectives of point-of-care tests for diagnosing diseases of veterinary interest. Nucleic-acid testing, particularly for the point of care, is addressed subsequently. A range of valuable signal transduction mechanisms commonly employed in proof-of-concept schemes and techniques born on the analytical chemistry laboratories are also described. As the essential core of this chapter, sections dedicated to the principles and applications of microfluidics, lab

  11. Interaction of the heterotrimeric G protein alpha subunit SSG-1 of Sporothrix schenckii with proteins related to stress response and fungal pathogenicity using a yeast two-hybrid assay

    Directory of Open Access Journals (Sweden)

    González-Méndez Ricardo

    2010-12-01

    Full Text Available Abstract Background Important biological processes require selective and orderly protein-protein interactions at every level of the signalling cascades. G proteins are a family of heterotrimeric GTPases that effect eukaryotic signal transduction through the coupling of cell surface receptors to cytoplasmic effector proteins. They have been associated with growth and pathogenicity in many fungi through gene knock-out studies. In Sporothrix schenckii, a pathogenic, dimorphic fungus, we previously identified a pertussis sensitive G alpha subunit, SSG-1. In this work we inquire into its interactions with other proteins. Results Using the yeast two-hybrid technique, we identified protein-protein interactions between SSG-1 and other important cellular proteins. The interactions were corroborated using co-immuneprecipitation. Using these techniques we identified a Fe/Mn superoxide dismutase (SOD, a glyceraldehyde-3-P dehydrogenase (GAPDH and two ion transport proteins, a siderophore-iron transporter belonging to the Major Facilitator Superfamily (MFS and a divalent-cation transporter of the Nramp (natural resistance-associated macrophage protein family as interacting with SSG-1. The cDNA's encoding these proteins were sequenced and bioinformatic macromolecular sequence analyses were used for the correct classification and functional assignment. Conclusions This study constitutes the first report of the interaction of a fungal G alpha inhibitory subunit with SOD, GAPDH, and two metal ion transporters. The identification of such important proteins as partners of a G alpha subunit in this fungus suggests possible mechanisms through which this G protein can affect pathogenicity and survival under conditions of environmental stress or inside the human host. The two ion transporters identified in this work are the first to be reported in S. schenckii and the first time they are identified as interacting with fungal G protein alpha subunits. The association

  12. Animals

    Institute of Scientific and Technical Information of China (English)

    杨光

    2000-01-01

    The largest animal ever to live on the earth is the blue whale(蓝鲸)It weighs about 80 tons--more than 24 elephants. It is more than 30 metres long. A newborn baby whale weighs as much as a big elephant.

  13. Are Bacterial Volatile Compounds Poisonous Odors to a Fungal Pathogen Botrytis cinerea, Alarm Signals to Arabidopsis Seedlings for Eliciting Induced Resistance, or Both?

    OpenAIRE

    Sharifi, Rouhallah; Ryu, Choong-Min

    2016-01-01

    Biological control (biocontrol) agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR). Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs) are determinants for eliciting plant ISR. Eme...

  14. ANIMALS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Mammals(哺乳动物)Mammals are the world's most dominant(最占优势的)animal.They are extremely(非常)diverse(多种多样的)creatures(生物,动物)that include(包括)the biggest ever animal (the blue whale鲸,which eats up to 6 tons every day),the smallest(leaf-nosed bat小蹄蝠) and the laziest(sloth树獭,who spends 80% of their time sleeping).There are over 4,600 kinds of mammals and they live in very different environments(环境)—oceans(海洋),rivers,the jungle(丛林),deserts,and plains(平原).

  15. Transformation of tobacco and Arabidopsis plants with Stellaria media genes encoding novel hevein-like peptides increases their resistance to fungal pathogens.

    Science.gov (United States)

    R Shukurov, Rahim; D Voblikova, Vera; Nikonorova, Alexandra K; Komakhin, Roman A; V Komakhina, Vera; A Egorov, Tsezi; V Grishin, Eugene; V Babakov, Alexey

    2012-04-01

    Two novel antifungal hevein-like peptides, SmAMP1.1a and SmAMP2.2a, were previously isolated from seeds of Stellaria media. It has been established that these peptides accumulate in this weed as a result of proteolysis of two propeptides, pro-SmAMP1 and pro-SmAMP2. The primary structure of these propeptides is unique; in addition to having a signal peptide and negatively charged C-terminus, each of these structures consists of two hevein-like peptides of different length separated by a space rather than a single peptide. In this work, we demonstrated that the expression of the pro-SmAMP1 and pro-SmAMP2 genes was tissue-specific and increased substantially under exposure to fungal infection. To elucidate whether S. media has any advantages in defending against phytopathogens due to its unusual structure of pro-SmAMP1 and pro-SmAMP2, on the basis of the pro-SmAMP1 gene, we created three genetic constructs. Arabidopsis and tobacco plants were subsequently transformed with these constructs. Transgenic plants bearing the full-length pro-SmAMP1 gene exhibited the best resistance to the phytopathogens Bipolaris sorokiniana and Thielaviopsis basicola. The resistance of S. media plants to phytopathogenic fungi was likely due to the fungal-inducible expression of pro-SmAMP1 and pro-SmAMP2 genes, and due to the specific features of the primary structure of the corresponding propeptides. As a result of the processing of these propeptides, two different antimicrobial peptides were released simultaneously. Based on our results, we conclude that the genes for antimicrobial peptides from S. media may be promising genetic tools for the improvement of plant resistance to fungal diseases.

  16. Fungal Tests

    Science.gov (United States)

    ... or Calcofluor white stain): in general, if fungal elements are seen, then a fungus is the likely the cause of symptoms. These tests, however, do not identify the fungus. Culture: care must be taken when interpreting culture results. ...

  17. Food-borne pathogens of animal origin-diagnosis, prevention, control and their zoonotic significance: a review.

    Science.gov (United States)

    Dhama, K; Rajagunalan, S; Chakraborty, S; Verma, A K; Kumar, A; Tiwari, R; Kapoor, S

    2013-10-15

    The term food borne diseases or food-borne illnesses or more commonly food poisoning are used to denote gastrointestinal complications that occur following recent consumption of a particular food or drink. Millions of people suffer worldwide every year and the situation is quiet grave in developing nations creating social and economic strain. The food borne pathogens include various bacteria viz., Salmonella, Campylobacter, Escherichia coli, Listeria monocytogenes, Yersinia enterocolitica, Staphylococcus, Arcobacter, Clostridium perfringens, Cl. botulinum and Bacillus cereus and helminths viz., Taenia. They also include protozoa viz., Trichinella, Sarcocystis, Toxoplasma gondii and Cryptosporidium parvum. The zoonotic potential and the ability to elaborate toxins by many of the microbes causing fatal intoxication are sufficient to understand the seriousness of the situation. The viral agents being host specific their transmission to humans through food of animal origin is not yet confirmed although these animal viruses are similar to that of viruses infecting human. Food-borne bacteria; protozoa and helminthes have complex distribution pattern in the environment and inside the host system. This along with complexity of the maintenance chain and life cycle (of parasites) has made it difficult for epidemiologist and diagnostician to undertake any immediate safety measures against them. Serological and molecular diagnostic tests viz. ELISA, Latex agglutination test, Lateral flow assays, Immunomagnetic separation assays, molecular assays viz. Polymerase Chain Reaction (PCR), multiplex PCR, immuno-PCR, Realtime PCR, Random Amplified Polymorphic DNA (RAPD)-PCR, DNA microarrays and probes are widely used. Along with these LAMP assays, Capillary Electrophoresis-Single Strand Confirmation polymorphism (CE-SSCP); Flow cytometry, FISH, Biosensors, Direct epifluorescent filter technique, nanotechnology based methods and sophisticated tools (ultrasonography, magnetic resonance

  18. The in vitro Antibacterial Activity of Florfenicol in Combination with Amoxicillin or Cefuroxime against Pathogenic Bacteria of Animal Origin

    Directory of Open Access Journals (Sweden)

    Myung-Jin Choia, Eun-Mi Leea, Seung-Jin Lee, Md. Ahsanur Reza, Joong-Su Lee, Elias Gebru, Man-Hee Rhee and Seung-Chun Park*

    2011-04-01

    Full Text Available This study evaluated the in vitro activity of florfenicol (F in combination with amoxicillin (AM or cefuroxime (CRM against pathogenic bacteria of animal origin, including E. coli, S. aureus, S. cholerasuis and P. mirabilis. The MIC of AM ranged from 16 to 256 μg/ml. The MBC of AM (64 μg/ml was four-fold higher than its MIC value (16 μg/ml for E. coli, and similar to the MIC for the other three species. The MIC of F ranged from 8 to 16 μg/ml. The MBC values of F for E. coli, S. aureus, and S. cholerasuis were eight-fold higher than the respective MIC values, and 32-fold higher than the MIC of P. mirabilis. The MIC of CRM ranged from 8 to 128 μg/ml. The MBC of CRM was the highest ( 256 μg/ml, except for E. coli. The F/AM combination resulted in synergism (FIC index  0.5 for E. coli, S. aureus, and P. mirabilis and in-difference (FIC index >1 for S. cholerasuis. For F/CRM combination, synergism (E. coli and S. cholerasuis and in-difference (S. aureus and P. mirabilis were observed. Killing rate study showed a 1.5 - > 3 log 10 cfu/ml reduction of E. coli with F/AM compared to AM or F alone. The highest activity of the combinations was observed when F comprised at least 50% of the combination. Further studies using many bacterial isolates and various proportion of each drug would reveal the potential of a combination product containing F and AM/CRM for use in veterinary practice.

  19. Fungal nail infection

    Science.gov (United States)

    Nails - fungal infection; Onychomycosis; Infection - fungal - nails; Tinea unguium ... the hair, nails, and outer skin layers. Common fungal infections include: Athlete's foot Jock itch Ringworm on the ...

  20. Two strains of Pseudomonas fluorscens bacteria differentially affect survivorship of waxworm (Galleria mellonella) larvae exposed to an arthropod fungal pathogen, Beauveria bassiana

    Science.gov (United States)

    Two strains of Pseudomonas fluorescens were found contaminating a biopesticide used in a previous study against Varroa destructor infestations in honey bee hives. In the aforementioned study the biopesticide, a formulation of the arthropod pathogen Beauveria bassiana, failed to have any impact on t...

  1. Molecular evidence of fungal signatures in the marine protist Corallochytrium limacisporum and its implications in the evolution of animals and fungi

    Digital Repository Service at National Institute of Oceanography (India)

    Manohar, C.S.; Raghukumar, S.; Kasbekar, D.P.; Raghukumar, C.

    of these cultures to grow on media containing inorganic nitrogen sources prompted us to examine the possible presence of fungal signatures, namely the enzyme α-aminoadipate reductase (α-AAR) involved in the α-aminoadipate (AAA) pathway for synthesizing lysine...

  2. Resistance to antimicrobial agents used for animal therapy in pathogenic , zoonotic and indicator bacteria isolated from different food animals in Denmark: A baseline study for the Danish Integrated Antimicrobial Resistance Monitoring Programme (DANMAP)

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Bager, Flemming; Jensen, N. E.;

    1998-01-01

    , Enterococcus faecium), 2) zoonotic bacteria (Campylobacter coli/jejuni, Salmonella enterica, Yelsinia enterocolitica), and 3) animal pathogens (E. coli, Staphylococcus aureus, coagulase-negative staphylococci (CNS), Staphylococcus hyicus, Actinobacillus pleuropneumoniae). A total of 3304 bacterial isolates......This study describes the establishment and first results of a continuous surveillance system of antimicrobial resistance among bacteria isolated from pigs, cattle and broilers in Denmark. The three categories of bacteria tested were: 1) indicator bacteria (Escherichia coli, Enterococcus faecalis...

  3. Fungal keratitis

    Directory of Open Access Journals (Sweden)

    Sonal S Tuli

    2011-02-01

    Full Text Available Sonal S TuliUniversity of Florida, Gainesville, FL, USA  Clinical question: What is the most appropriate management of fungal keratitis?Results: Traditionally, topical Natamycin is the most commonly used medication for filamentous fungi while Amphotericin B is most commonly used for yeast. Voriconazole is rapidly becoming the drug of choice for all fungal keratitis because of its wide spectrum of coverage and increased penetration into the cornea.Implementation: Repeated debridement of the ulcer is recommended for the penetration of topical medications. While small, peripheral ulcers may be treated in the community, larger or central ulcers, especially if associated with signs suggestive of anterior chamber penetration should be referred to a tertiary center. Prolonged therapy for approximately four weeks is usually necessary.Keywords: fungal keratitis, keratomycosis, antifungal medications, debridement

  4. Highly pathogenic avian influenza (H5N1: pathways of exposure at the animal-human interface, a systematic review.

    Directory of Open Access Journals (Sweden)

    Maria D Van Kerkhove

    Full Text Available BACKGROUND: The threat posed by highly pathogenic avian influenza A H5N1 viruses to humans remains significant, given the continued occurrence of sporadic human cases (499 human cases in 15 countries with a high case fatality rate (approximately 60%, the endemicity in poultry populations in several countries, and the potential for reassortment with the newly emerging 2009 H1N1 pandemic strain. Therefore, we review risk factors for H5N1 infection in humans. METHODS AND FINDINGS: Several epidemiologic studies have evaluated the risk factors associated with increased risk of H5N1 infection among humans who were exposed to H5N1 viruses. Our review shows that most H5N1 cases are attributed to exposure to sick poultry. Most cases are sporadic, while occasional limited human-to-human transmission occurs. The most commonly identified factors associated with H5N1 virus infection included exposure through contact with infected blood or bodily fluids of infected poultry via food preparation practices; touching and caring for infected poultry; [corrected] exposure to H5N1 via swimming or bathing in potentially virus laden ponds; and exposure to H5N1 at live bird markets. CONCLUSIONS: Research has demonstrated that despite frequent and widespread contact with poultry, transmission of the H5N1 virus from poultry to humans is rare. Available research has identified several risk factors that may be associated with infection including close direct contact with poultry and transmission via the environment. However, several important data gaps remain that limit our understanding of the epidemiology of H5N1 in humans. Although infection in humans with H5N1 remains rare, human cases continue to be reported and H5N1 is now considered endemic among poultry in parts of Asia and in Egypt, providing opportunities for additional human infections and for the acquisition of virus mutations that may lead to more efficient spread among humans and other mammalian species

  5. Screening of plant and fungal metabolites in wheat, maize and animal feed using automated on-line clean-up coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Ates, Ebru; Godula, Michal; Stroka, Joerg; Senyuva, Hamide

    2014-01-01

    A wide range of plant and fungal metabolites can occur in cereals and feed but only a limited number of target compounds are sought. This screening method is using a database of over 600 metabolites to establish contamination profiles in food and feed. Extracts were injected directly into an automated turbulent flow sample clean-up system, coupled to a liquid-chromatography-high-resolution-mass-spectrometer (Orbitrap). Compound identification criteria for database searching were defined and the approach was validated by spiking plant and fungal metabolites into cereals and feed. A small survey of market samples (15) and quality control materials (9) of maize, wheat and feed was conducted using this method. Besides regulated and known secondary metabolites, fumiquinazoline F, fusarochromanone and dihydrofusarubin were identified for the first time in samples of maize and oats. This method enables clean-up of crude extracts within 18min and screening and confirmation of a wide range of different compound classes.

  6. Evaluation of Patients with Community-Acquired Pneumonia Caused by Zoonotic Pathogens in an Area with a High Density of Animal Farms.

    Science.gov (United States)

    Huijskens, E G W; Smit, L A M; Rossen, J W A; Heederik, D; Koopmans, M

    2016-03-01

    Intensive animal farming could potentially lead to outbreaks of infectious diseases. Clinicians are at the forefront of detecting unusual diseases, but the lack of specificity of zoonotic disease symptoms makes this a challenging task. We evaluated patients with community-acquired pneumonia (CAP) with known and unknown aetiology in an area with a high livestock density and a potential association with animal farms in the proximity. Between 2008 and 2009, a period coinciding with a large Q fever outbreak in the Netherlands, patients with CAP were tested for the presence of possible respiratory pathogens. The presence and number of farm animals within 1 km of the patients' home address were assessed using geographic information system (GIS) and were compared between cases and age-matched control subjects. Of 408 patients with CAP, pathogens were detected in 275 (67.4%) patients. The presence of sheep and the number of goats were associated with CAP caused by Coxiella burnetii in a multiple logistic regression model (P animal farms (P > 0.10). The use of GIS in combination with aetiology of CAP could be potentially used to target diagnostics and to identify outbreaks of rare zoonotic disease.

  7. Pathogenic features and risk factors of invasive fungal infection in patients with hematopathy%血液病合并侵袭性真菌感染病原学及危险因素

    Institute of Scientific and Technical Information of China (English)

    王凡; 韩志海; 孟激光; 李泳群; 陈韦; 赵春亭

    2015-01-01

    Objective To investigate the status of invasive fungal infection(IFI)associated with hematopathy,and evaluate drug resistance and risk factors of fungal infection.Methods 1 246 cases of infection occurred in patients in a hospital from 2006 to 2010 were analyzed retrospectively,pathogenic features and risk factors of IFI were ana-lyzed.Results There were 281 cases of fungal infection,and 162 fungal isolates were isolated,the main infection site was respiratory tract(134 isolates,82.72%).Four major Candida were Candida albicans ,Candida tropicalis , Candida glabrata ,and Candida krusei ;in 2006-2009,the main fungi were Candida albicans ,while in 2010,the majority were non-Candida albicans .The resistant rates of four isolated Candida to fluconazole and itraconazole were 5.15% and 4.41 % respectively,6 isolated Candida krusei strains were all resistant to both fluconazole and itraconazole,voriconazole-resistant strain was not found.The independent risk factors for fungal infection were dia-betes and duration time of agranulocytosis>14 days.Conclusion The proportion of infection caused by non-Candi-da albicans increased obviously,fluconazole-and itraconazole-resistant non-Candida albicans strains have emerged, comprehensive measures should be adopted to prevent IFI actively and treat patients early.%目的:了解血液病合并侵袭性真菌感染(IFI)的现状,分析真菌耐药情况及感染的危险因素。方法回顾性分析2006—2010年某院血液病科合并感染的患者1246例次,对 IFI 患者病原学特点及危险因素进行分析。结果真菌感染281例次,分离真菌162株,感染部位以呼吸道(134株,占82.72%)为主。4种主要酵母菌为白假丝酵母菌、热带假丝酵母菌、光滑假丝酵母菌和克柔假丝酵母菌;2006—2009年均以白假丝酵母菌为主,2010年非白假丝酵母菌超过白假丝酵母菌。4种主要酵母菌对氟康唑和伊曲康唑的总耐药率分别为5.15%和4

  8. Fungal communities in barren forest soil after amendment with different wood substrates and their possible effects on trees’, pathogens, insects and nematodes

    Directory of Open Access Journals (Sweden)

    Małecka Monika

    2015-07-01

    Full Text Available Scots pine sawdust, composted bark or coarse, post-harvest woody debris from conifers had been spread over the surface of barren forest soil before planting with Scots pine. The effects of the Scots pine sawdust, composted bark or coarse, post-harvest woody debris from conifers on the abundance and diversity of culturable fungi were investigated. The amendments were aimed at increasing the soil suppressiveness to Armillaria and Heterobasidion. The classical soil-dilution method was chosen for qualitative and quantitative analyses of fungal communities in soils because of its proven reliability and consistency. The soil was inhabited by saprotrophic fungi from Ascomycota and Zygomycota, including species known to be potential antagonists of Armillaria or H. annosum (i.e. Clonostachys + Trichoderma spp., Penicillium commune, P. daleae, P. janczewskii or stimulants of Armillaria (i.e. Pseudogymnoascus roseus, Trichocladium opacum. Eleven years after treatment, the abundance and diversity of fungi, the abundance of P. commune, and locally the abundance of P. janczewskii increased, while Clonostachys + Trichoderma spp., and locally, P. daleae and T. opacum decreased. Amending the barren soil with organic matter does not guarantee effective, long-term suppressiveness of the sandy loam soil to Armillaria and Heterobasidion. Increased abundance of entomopathogenic and nematophagous species, 11 years after treatment, does suggest the long-term possibility of insect or nematode control in soil.

  9. 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.

  10. ICU留置尿管患者尿路真菌定植与感染的研究%Research of urinary tract fungal colonization and pathogenicity in ICU patients with indwelling catheter

    Institute of Scientific and Technical Information of China (English)

    叶宁; 骆雪萍; 黄巍

    2014-01-01

    OBJECTIVE To study the types of urinary tract fungal colonization and pathogenicity status in intensive care unit (ICU ) patients with indwelling catheter , to provide reasonable basis for clinical prevention and treatment .METHODS A retrospective study was conducted involving 81 patients with positive results of midstream urine fungus culture in ICU during Jun .2011 to Dec .2012 .Patients were divided into the colonization group and the pathogenicity group according to the fungal colony count .The type of fungal infections ,incidence of complications were analyzed and compared between the two groups .Data were processed by SPSS 13 .0 software . RESULTS Totally 81 strains of fungi were isolated ,among them ,47 strains were Candida albicans accounting for 58 .02% ,24 strains were C . tropicalis accounting for 29 .62% ,and 7 were C . glabrata (8 .64% ) .The main fungus type in the pathogenicity group was C .tropicalis(17/31 ,54 .8% ) ,while the main fungus in the coloniza-tion group was C .albicans (36/50 ,72% ) .The incidence of bloody urine of two groups was high (64 .5% and 62 .0% respectively) .There were significant differences in combined urinary tract bacterial infections or infections in other sites ,however ,the incidence of combined multi-site infections was high in both groups (the pathogenicity group 90 .32% ,the colonization group 82 .00% ) .The rate of combined multi-drug resistant (MDR) bacterial in-fection was significantly higher in the pathogenicity group than in the colonization group(P<0 .05) .CONCLUSION The type of urinary tract fungi was associated with infection status in ICU patients with indwelling catheter .Fun-gal urinary tract infection often co-existed with bacterial infection ,the incidence of combined MDR was higher in pathogenic status ,active prevention and treatment was beneficial to control systemic infections for patients .%目的:研究重症监护病房(IC U )留置尿管患者尿路感染的真菌类型和定植状况,

  11. 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

  12. 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.

  13. 2012 CELLULAR & MOLECULAR FUNGAL BIOLOGY GORDON RESEARCH CONFERENCE, JUNE 17 - 22, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Judith Berman

    2012-06-22

    The Gordon Research Conference on CELLULAR & MOLECULAR FUNGAL BIOLOGY was held at Holderness School, Holderness New Hampshire, June 17 - 22, 2012. The 2012 Gordon Conference on Cellular and Molecular Fungal Biology (CMFB) will present the latest, cutting-edge research on the exciting and growing field of molecular and cellular aspects of fungal biology. Topics will range from yeast to filamentous fungi, from model systems to economically important organisms, and from saprophytes and commensals to pathogens of plants and animals. The CMFB conference will feature a wide range of topics including systems biology, cell biology and morphogenesis, organismal interactions, genome organisation and regulation, pathogenesis, energy metabolism, biomass production and population genomics. The Conference was well-attended with 136 participants. Gordon Research Conferences does not permit publication of meeting proceedings.

  14. Utilizing virus-induced gene silencing for the functional characterization of maize genes during infection with the fungal pathogen Ustilago maydis.

    Science.gov (United States)

    van der Linde, Karina; Doehlemann, Gunther

    2013-01-01

    While in dicotyledonous plants virus-induced gene silencing (VIGS) is well established to study plant-pathogen interaction, in monocots only few examples of efficient VIGS have been reported so far. One of the available systems is based on the brome mosaic virus (BMV) which allows gene silencing in different cereals including barley (Hordeum vulgare), wheat (Triticum aestivum), and maize (Zea mays).Infection of maize plants by the corn smut fungus Ustilago maydis leads to the formation of large tumors on stem, leaves, and inflorescences. During this biotrophic interaction, plant defense responses are actively suppressed by the pathogen, and previous transcriptome analyses of infected maize plants showed comprehensive and stage-specific changes in host gene expression during disease progression.To identify maize genes that are functionally involved in the interaction with U. maydis, we adapted a VIGS system based on the Brome mosaic virus (BMV) to maize at conditions that allow successful U. maydis infection of BMV pre-infected maize plants. This setup enables quantification of VIGS and its impact on U. maydis infection using a quantitative real-time PCR (q(RT)-PCR)-based readout.

  15. InvA protein is a Nudix hydrolase required for infection by pathogenic Leptospira in cell lines and animals.

    Science.gov (United States)

    Luo, Yihui; Liu, Yan; Sun, Dexter; Ojcius, David M; Zhao, Jinfang; Lin, Xuai; Wu, Dong; Zhang, Rongguang; Chen, Ming; Li, Lanjuan; Yan, Jie

    2011-10-21

    Leptospirosis caused by pathogenic species of the genus Leptospira is a re-emerging zoonotic disease, which affects a wide variety of host species and is transmitted by contaminated water. The genomes of several pathogenic Leptospira species contain a gene named invA, which contains a Nudix domain. However, the function of this gene has never been characterized. Here, we demonstrated that the invA gene was highly conserved in protein sequence and present in all tested pathogenic Leptospira species. The recombinant InvA protein of pathogenic L. interrogans strain Lai hydrolyzed several specific dinucleoside oligophosphate substrates, reflecting the enzymatic activity of Nudix in Leptospira species. Pathogenic leptospires did not express this protein in media but temporarily expressed it at early stages (within 60 min) of infection of macrophages and nephric epithelial cells. Comparing with the wild type, the invA-deficient mutant displayed much lower infectivity and a significantly reduced survival rate in macrophages and nephric epithelial cells. Moreover, the invA-deficient leptospires presented an attenuated virulence in hamsters, caused mild histopathological damage, and were transmitted in lower numbers in the urine, compared with the wild-type strain. The invA revertant, made by complementing the invA-deficient mutant with the invA gene, reacquired virulence similar to the wild type in vitro and in vivo. The LD(50) in hamsters was 1000-fold higher for the invA-deficient mutant than for the invA revertant and wild type. These results demonstrate that the InvA protein is a Nudix hydrolase, and the invA gene is essential for virulence in pathogenic Leptospira species.

  16. Histopathological changes induced in an animal model by potentially pathogenic Enterococcus faecalis strains recovered from ready-to-eat food outlets in Osun State, Nigeria

    Directory of Open Access Journals (Sweden)

    Olawale AK

    2015-06-01

    Full Text Available Adetunji Kola Olawale,1,2 Oluwole Moses David,2,3 Adekemi Olubukunola Oluyege,2 Richard Temitope Osuntoyinbo,4 Solomon Anjuwon Laleye,5 Oladiran Famurewa,21Department of Applied Sciences, Osun State Polytechnic, Iree, 2Department of Microbiology, University of Ado-Ekiti, Ado-Ekiti, Nigeria; 3Phytomedicine Research Centre, Department of Botany, University of Fort Hare, Alice, South Africa; 4Department of Microbiology, Waterford Regional Hospital, Waterford, Republic of Ireland; 5Department of Microbiology, Adekunle Ajasin University, Akungba-Akoko, NigeriaAbstract: Enterococci have been implicated as an emerging important cause of several diseases and multiple antibiotic resistance. However, there is little information about the prevalence of pathogenic and/or antibiotic-resistant Enterococcus faecalis in ready-to-eat foods in Nigeria. Here we report the pathogenic potential of three selected antibiotic-resistant E. faecalis strains isolated from food canteens and food outlets with different virulence determinant genes, including EFC 12 (with gel+, esp+, cylA+, and asa1+, EFT 148 (with gel+, ace+, and asa1+, and EFS 18 (with esp+ and cylA+ in an animal model. Enterococcemia, hematological parameters, and histopathological changes in organ tissues were examined in experimental animals. The results showed differences in enterococcemia and hematological parameters between the control group and experimental animal group. Enterococcemia was observed for 7 days, and the animal group infected with EFC 12 showed the highest growth rate, followed by EFT 148, with the lowest growth rate seen in the EFS 18-infected group. White blood cell count, packed cell volume, and platelets were significantly reduced (P<0.05 in the experimental animals compared with the controls. White blood cells decreased drastically during the study period in rats challenged with EFC 12 (from 7,800 to 6,120 per mm3 but levels remained higher in the control group (from 9,228 to 9

  17. High gene flow and outcrossing within populations of two cryptic fungal pathogens on a native and non-native host in Cameroon.

    Science.gov (United States)

    Begoude Boyogueno, Aime Didier; Slippers, Bernard; Perez, Guillermo; Wingfield, Michael J; Roux, Jolanda

    2012-03-01

    In this study, we determined the genetic diversity of 126 isolates representing both Lasiodiplodia theobromae and Lasiodiplodia pseudotheobromae, collected from Theobroma cacao and Terminalia spp. in Cameroon, using simple sequence repeat (SSR) markers. SSR alleles showed clear genetic distinction between L. theobromae and L. pseudotheobromae, supporting their earlier separation as sister species. Both L. theobromae and L. pseudotheobromae populations from Cameroon had high levels of gene diversity, moderate degrees of genotypic diversity, and high levels of gene flow between isolates from T. cacao and Terminalia spp. There was no evidence for geographic substructure in these populations across the region studied, and the SSR alleles were randomly associated in both species, suggesting outcrossing. The significant levels of aggressiveness, evolutionary potential represented by high levels of diversity, outcrossing and gene flow between geographically and host defined populations, identify these fungi as high-risk pathogens for their native and non-native hosts in Cameroon. PMID:22385617

  18. The post-transcriptional regulator CsrA plays a central role in the adaptation of bacterial pathogens to different stages of infection in animal hosts.

    Science.gov (United States)

    Lucchetti-Miganeh, Céline; Burrowes, Elizabeth; Baysse, Christine; Ermel, Gwennola

    2008-01-01

    The importance of Csr post-transcriptional systems is gradually emerging; these systems control a variety of virulence-linked physiological traits in many pathogenic bacteria. This review focuses on the central role that Csr systems play in the pathogenesis of certain bacteria and in the establishment of successful infections in animal hosts. Csr systems appear to control the 'switch' between different physiological states in the infection process; for example switching pathogens from a colonization state to a persistence state. Csr systems are controlled by two-component sensor/regulator systems and by non-coding RNAs. In addition, recent findings suggest that the RNA chaperone Hfq may play an integral role in Csr-mediated bacterial adaptation to the host environment. PMID:18174122

  19. The post-transcriptional regulator CsrA plays a central role in the adaptation of bacterial pathogens to different stages of infection in animal hosts.

    Science.gov (United States)

    Lucchetti-Miganeh, Céline; Burrowes, Elizabeth; Baysse, Christine; Ermel, Gwennola

    2008-01-01

    The importance of Csr post-transcriptional systems is gradually emerging; these systems control a variety of virulence-linked physiological traits in many pathogenic bacteria. This review focuses on the central role that Csr systems play in the pathogenesis of certain bacteria and in the establishment of successful infections in animal hosts. Csr systems appear to control the 'switch' between different physiological states in the infection process; for example switching pathogens from a colonization state to a persistence state. Csr systems are controlled by two-component sensor/regulator systems and by non-coding RNAs. In addition, recent findings suggest that the RNA chaperone Hfq may play an integral role in Csr-mediated bacterial adaptation to the host environment.

  20. Evaluation of Patients with Community-Acquired Pneumonia Caused by Zoonotic Pathogens in an Area with a High Density of Animal Farms.

    Science.gov (United States)

    Huijskens, E G W; Smit, L A M; Rossen, J W A; Heederik, D; Koopmans, M

    2016-03-01

    Intensive animal farming could potentially lead to outbreaks of infectious diseases. Clinicians are at the forefront of detecting unusual diseases, but the lack of specificity of zoonotic disease symptoms makes this a challenging task. We evaluated patients with community-acquired pneumonia (CAP) with known and unknown aetiology in an area with a high livestock density and a potential association with animal farms in the proximity. Between 2008 and 2009, a period coinciding with a large Q fever outbreak in the Netherlands, patients with CAP were tested for the presence of possible respiratory pathogens. The presence and number of farm animals within 1 km of the patients' home address were assessed using geographic information system (GIS) and were compared between cases and age-matched control subjects. Of 408 patients with CAP, pathogens were detected in 275 (67.4%) patients. The presence of sheep and the number of goats were associated with CAP caused by Coxiella burnetii in a multiple logistic regression model (P 0.10). The use of GIS in combination with aetiology of CAP could be potentially used to target diagnostics and to identify outbreaks of rare zoonotic disease. PMID:26214299

  1. Tropospheric ozone as a fungal elicitor

    Indian Academy of Sciences (India)

    Paolo Zuccarini

    2009-03-01

    Tropospheric ozone has been proven to trigger biochemical plant responses that are similar to the ones induced by an attack of fungal pathogens, i.e. it resembles fungal elicitors. This suggests that ozone can represent a valid tool for the study of stress responses and induction of resistance to pathogens. This review provides an overview of the implications of such a phenomenon for basic and applied research. After an introduction about the environmental implications of tropospheric ozone and plant responses to biotic stresses, the biochemistry of ozone stress is analysed, pointing out its similarities with plant responses to pathogens and its possible applications.

  2. Lectins of fungal pathogens as potential tools in selecting promising biological control agents of Trichoderma spp%植物病原菌凝集素用于筛选生防木霉菌

    Institute of Scientific and Technical Information of China (English)

    杨合同; 唐文华; Maarten Ryder; 李纪顺; 郭勇; 周红姿

    2004-01-01

    In this article, lectins of eight pathogen strains were extracted and purified. By testing agglutination lectins with 19 Trichoderma spp. srains, all lectins from fungi agglutinated the conidia of Trichoderma spp. with different titers, except lectin from Alternaria solani Ms. Result indicated that the agglutination of Trichoderma conidia by fungal lectins was related to their effectiveness caused by the corresponding pathogens. Statistical analysis showed significant correlation between titers of Fusarium lectin and the effectiveness of Trichoderma against the disease.The agglutination test might be applied to predict potential effectiveness of a given Trichoderma strain against the corresponding disease and the lectins could be employed in screening Trichoderma spp as biocontrol agents efficiently.%提取并纯化了番茄早疫病、黑根霉、棉花立枯病菌和黄瓜灰霉病菌等8个植物病原菌菌株的凝集素,试验观察凝集素与供试19个木霉菌株的凝集反应效价,结果表明除番茄早疫病外,木霉菌分生孢子不同浓度悬浮液与植物病原菌产生的凝集素均有凝集反应,并且木霉菌分生孢子与病原菌凝集素的凝集反应效价与木霉菌对其防效有显著相关性,统计分析表明镰刀菌产生的凝集素与木霉菌的凝集反应效价与木霉菌对它的防效具有显著相关性.因此可以利用凝集素筛选木霉高效生防菌株.

  3. Comparative Phylogenomics of Pathogenic and Nonpathogenic Species

    OpenAIRE

    Emily Whiston; Taylor, John W.

    2016-01-01

    The Ascomycete Onygenales order embraces a diverse group of mammalian pathogens, including the yeast-forming dimorphic fungal pathogens Histoplasma capsulatum, Paracoccidioides spp. and Blastomyces dermatitidis, the dermatophytes Microsporum spp. and Trichopyton spp., the spherule-forming dimorphic fungal pathogens in the genus Coccidioides, and many nonpathogens. Although genomes for all of the aforementioned pathogenic species are available, only one nonpathogen had been sequenced. Here, we...

  4. Fungal invasion of the rhizosphere microbiome.

    Science.gov (United States)

    Chapelle, Emilie; Mendes, Rodrigo; Bakker, Peter A H M; Raaijmakers, Jos M

    2016-01-01

    The rhizosphere is the infection court where soil-borne pathogens establish a parasitic relationship with the plant. To infect root tissue, pathogens have to compete with members of the rhizosphere microbiome for available nutrients and microsites. In disease-suppressive soils, pathogens are strongly restricted in growth by the activities of specific rhizosphere microorganisms. Here, we sequenced metagenomic DNA and RNA of the rhizosphere microbiome of sugar beet seedlings grown in a soil suppressive to the fungal pathogen Rhizoctonia solani. rRNA-based analyses showed that Oxalobacteraceae, Burkholderiaceae, Sphingobacteriaceae and Sphingomonadaceae were significantly more abundant in the rhizosphere upon fungal invasion. Metatranscriptomics revealed that stress-related genes (ppGpp metabolism and oxidative stress) were upregulated in these bacterial families. We postulate that the invading pathogenic fungus induces, directly or via the plant, stress responses in the rhizobacterial community that lead to shifts in microbiome composition and to activation of antagonistic traits that restrict pathogen infection. PMID:26023875

  5. Fungal genus Hypocrea/Trichoderma: from barcodes to biodiversity

    Institute of Scientific and Technical Information of China (English)

    Christian P. KUBICEK; Monika KOMON-ZELAZOWSKA; Irina S. DRUZHININA

    2008-01-01

    Hypocrea/Trichoderma is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immuno-compromised humans and animals, while others can cause damage to cultivated mushroom. With the recent advent of a reliable, BarCode-aided identification system for all known taxa of Trichoderma and Hypocrea, it became now possible to study some of the biological fundamentals of the diversity in this fungal genus in more detail. In this article, we will therefore review recent progress in (1) the understanding of the geographic distribution of individual taxa; (2) mechanisms of speciation leading to development of mushroom diseases and facultative human mycoses; and (3) the possible correlation of specific traits of secondary metabolism and molecular phylogeny.

  6. Inoculation experimental animals with Paracoccidioides brasiliensis strains: an attempt to reestablish the dimorphic process and variation in pathogenicity as a function of time of preservation under mineral oil.

    Science.gov (United States)

    Mendes da Silva, A M; Borba, C M; de Oliveira, P C

    1996-01-01

    In an attempt to reestablish the dimorphic process in strains of Paracoccidioides brasiliensis in the transition phase (Y reversible M) and to reisolate them, five strains in the transitional phase due to the long time of preservation under mineral oil and two strains in the yeast-like phase were inoculated into male albino rats. The animals were then studied for the presence of paracoccidioidomycotic granulomata. Of the seven strains inoculated, five caused granulomatous nodules in several organs of the animals and only two of these five strains, which had been preserved for the shortest period of time (9 years) were reisolated in culture. Two strains were unable to provoke infection, with no lesions detected in any organ. It is assumed that the long period of time during which the strains were left under oil favored the alteration of celt wall contents, leading to differences in pathogenicity.

  7. Characterisation of Yersinia pseudotuberculosis isolated from animals with yersiniosis during 1996-2013 indicates the presence of pathogenic and Far Eastern strains in Italy.

    Science.gov (United States)

    Magistrali, C F; Cucco, L; Pezzotti, G; Farneti, S; Cambiotti, V; Catania, S; Prati, P; Fabbi, M; Lollai, S; Mangili, P; Sebastiani, C; Bano, L; Dionisi, A M; Luzzi, I

    2015-10-22

    Yersinia pseudotuberculosis is a pathogen that infects both animals and humans worldwide. The epidemiology of infection caused by Y. pseudotuberculosis is poorly understood; however, its outbreaks have been traced back to a probable source in wildlife. This study aimed to characterise Y. pseudotuberculosis isolates collected from animals with yersiniosis. This study included 90 isolates of Y. pseudotuberculosis collected from different animals with yersiniosis between 1996 and 2013 in Italy. The isolates were tested for antimicrobial susceptibility and were biotyped. Genes associated with virulence plasmid pYV and those encoding O-antigen, high pathogenicity island (HPI), and superantigenic toxin (YPM) were determined by performing PCR. Pulsed-field gel electrophoresis (PFGE) was performed using NotI and SpeI enzymes, and 3 dendrograms were generated. No antibiotic resistance was found. The presence of pYV was shown in 57 out of 90 isolates. Virulence profiles of majority of the isolates indicated that they belonged to O:1a and O:1b serotypes, biotype 1, and genetic type 2. Isolates belonging to O:2a serotype were detected in sheep and cattle and were found to be associated (for the first time) with septicemia in hares. Y. pseudotuberculosis isolates belonging to O:5a and O:12-O13 serotypes were also detected in hares. To our knowledge, this is the first study to detect Y. pseudotuberculosis isolates belonging to the O:12-O13 serotype from a clinical case in Europe. Results of PFGE indicated that it was a reliable method for investigating the genetic relatedness of Y. pseudotuberculosis isolates. Thus, characterisation of Y. pseudotuberculosis infection in animals should be considered a possible tool for the surveillance of pseudotuberculosis.

  8. Long-distance wind-dispersal of spores in a fungal plant pathogen: estimation of anisotropic dispersal kernels from an extensive field experiment.

    Directory of Open Access Journals (Sweden)

    Adrien Rieux

    Full Text Available Given its biological significance, determining the dispersal kernel (i.e., the distribution of dispersal distances of spore-producing pathogens is essential. Here, we report two field experiments designed to measure disease gradients caused by sexually- and asexually-produced spores of the wind-dispersed banana plant fungus Mycosphaerella fijiensis. Gradients were measured during a single generation and over 272 traps installed up to 1000 m along eight directions radiating from a traceable source of inoculum composed of fungicide-resistant strains. We adjusted several kernels differing in the shape of their tail and tested for two types of anisotropy. Contrasting dispersal kernels were observed between the two types of spores. For sexual spores (ascospores, we characterized both a steep gradient in the first few metres in all directions and rare long-distance dispersal (LDD events up to 1000 m from the source in two directions. A heavy-tailed kernel best fitted the disease gradient. Although ascospores distributed evenly in all directions, average dispersal distance was greater in two different directions without obvious correlation with wind patterns. For asexual spores (conidia, few dispersal events occurred outside of the source plot. A gradient up to 12.5 m from the source was observed in one direction only. Accordingly, a thin-tailed kernel best fitted the disease gradient, and anisotropy in both density and distance was correlated with averaged daily wind gust. We discuss the validity of our results as well as their implications in terms of disease diffusion and management strategy.

  9. From Glacier to Sauna: RNA-Seq of the Human Pathogen Black Fungus Exophiala dermatitidis under Varying Temperature Conditions Exhibits Common and Novel Fungal Response.

    Directory of Open Access Journals (Sweden)

    Barbara Blasi

    Full Text Available Exophiala dermatitidis (Wangiella dermatitidis belongs to the group of the so-called black yeasts. Thanks in part to its thick and strongly melanized cell walls, E. dermatitidis is extremely tolerant to various kinds of stress, including extreme pH, temperature and desiccation. E. dermatitidis is also the agent responsible for various severe illnesses in humans, such as pneumonia and keratitis, and might lead to fatal brain infections. Due to its association with the human environment, its poly-extremophilic lifestyle and its pathogenicity in humans, E. dermatitidis has become an important model organism. In this study we present the functional analysis of the transcriptional response of the fungus at 1°C and 45°C, in comparison with that at 37°C, for two different exposition times, i.e. 1 hour and 1 week. At 1°C, E. dermatitidis uses a large repertoire of tools to acclimatize, such as lipid membrane fluidization, trehalose production or cytoskeleton rearrangement, which allows the fungus to remain metabolically active. At 45°C, the fungus drifts into a replicative state and increases the activity of the Golgi apparatus. As a novel finding, our study provides evidence that, apart from the protein coding genes, non-coding RNAs, circular RNAs as well as fusion-transcripts are differentially regulated and that the function of the fusion-transcripts can be related to the corresponding temperature condition. This work establishes that E. dermatitidis adapts to its environment by modulating coding and non-coding gene transcription levels and through the regulation of chimeric and circular RNAs.

  10. Clinical characteristics and pathogens of invasive fungal infections in children%儿童侵袭性真菌感染的临床特征及病原菌分析

    Institute of Scientific and Technical Information of China (English)

    常莉; 石华; 周伟; 胡正强; 母丽媛; 苏敏; 旷凌寒; 江咏梅

    2012-01-01

    目的 探讨儿童侵袭性真菌感染的临床特征及病原菌分布.方法 回顾性分析2008~2012年间诊断为侵袭性真菌感染的104例患儿的临床资料.结果 104例患儿中,新生儿20例,婴幼儿48例,学龄前期及学龄期儿童(年长儿)36例.新生儿组中,早产儿比例较高(70%);多患有肺透明膜病(45%)、肺炎(30%)等基础疾病;给予全胃肠外营养的患儿比例较其他两个年龄组高(P<0.01).新生儿组及婴幼儿组机械通气比例明显高于年长儿组(P<0.05).年长儿组多为血液恶性肿瘤患儿,粒细胞减少及接受化疗的患儿比例较其他两个年龄组高(P<0.05).感染部位以肺部多见(61.5%),其次为败血症(14.4%)、肠道(12.5%),神经系统感染仅见于年长儿.104例患儿中共分离出105株真菌,包括假丝酵母菌90株,隐球菌6株和其他真菌9株,以白色假丝酵母菌最多(52/105,49.5%),非白色假丝酵母菌比例也较高(38/105,36.2%).假丝酵母菌对5-氟胞嘧啶及两性霉素B的敏感性较高,对三唑类药物敏感性相对较低.结论 侵袭性真菌感染可发生于各年龄儿童,各年龄组间危险因素有异同;假丝酵母菌是其主要病原菌,白色假丝酵母菌所占比例高,非白色假丝酵母菌也占较高比例.假丝酵母菌对5-氟胞嘧啶和两性霉素B较为敏感.%Objective To study the clinical characteristics and pathogens of invasive fungal infection in children. Methods The clinical data of 104 children who suffered from invasive fungal infections between 2008 and 2012 was retrospectively reviewed. Results Of the 104 cases, 20 occurred in neonates, 48 in infants and 36 in preschool and school-aged children (old-aged children). Prematurity (70% ) , hyaline membrane disease (45% ) and pneumonia (30% ) were commonly comorbid in the neonate group. In addition, the percentage of cases receiving total parenteral nutrition was higher in the neonate group than in the other two age

  11. Inhibitory Activity of Garlic against Fungal Pathogens of Crops%大蒜素对三种农作物病原真菌的抑制作用

    Institute of Scientific and Technical Information of China (English)

    曾东方; 陈玢; 曾麟; 桓娇

    2011-01-01

    采用水浸提法和乙醇萃取法制备大蒜素,对稻瘟病菌(Pyricularia oryzae)、小麦纹枯病菌(Rhizoctonia cerealis)、油菜菌核病菌(Sclerotinia sclerotiorum)进行体外抑制试验,结果表明,水浸提法制备的20mg/mL大蒜素对3种真菌的抑菌效果分别达到70.6%、83.6%、94.3%,乙醇萃取法制备的20 mf/mL大蒜素的抑菌效果分别达到79.7%、89.7%、93.0%,供试最低抑菌浓度5 mg/mL大蒜素的抑菌效果分别达到29.0%、61.0%、93.7%,显示大蒜提取液对稻瘟病菌、小麦纹枯病菌、油菜菌核病菌都有较强的抑制作用,对油菜菌核病菌的抑制作用最强.结果提示,大蒜提取液对植物病原真菌抑制作用的强弱因供试菌、提取方法、作用浓度而异,这为开发农用抗生素对农作物病害进行生物防治提供了实践依据.%In vitro activity of garlic against Pyricularia oryzae, Rhizoctonia cerealis ,Sclerotinia sclerotiorum was tested. The resuits showed tha for the garlic prepared from water leach, the inhibitory effect on P. oryzae, R. cerealis,S, sclerotiorum was 70.6%,83.6% and 94.3%, respectively; while that for the garlic prepared from achohol extraction was 79.7%,89.7% and 93.0% respectively. The antifungal activity of garlic at MIC,5mg/mL,on the three fungi was 29.0%,61.0% and 93.7% respectively,which meant that garlic extraction has strong inhibitory effect against the three fungi. The inhibitory effect of garlic against plant pathogenic fungi differed according to different fungi, extrating method and concentration; and this offered a base for developing agro-antibiotic for bio-controling of crop diseases.

  12. Redox proteomics changes in the fungal pathogen Trichosporon asahii on arsenic exposure: identification of protein responses to metal-induced oxidative stress in an environmentally-sampled isolate.

    Directory of Open Access Journals (Sweden)

    Sidra Ilyas

    Full Text Available Trichosporon asahii is a yeast pathogen implicated in opportunistic infections. Cultures of an isolate collected from industrial wastewater were exposed for 2 days to 100 mg/L sodium arsenite (NaAsO2 and cadmium (CdCl2. Both metals reduced glutathione transferase (GST activity but had no effect on superoxide dismutase or catalase. NaAsO2 exposure increased glutathione reductase activity while CdCl2 had no effect. Protein thiols were labeled with 5-iodoacetamido fluorescein followed by one dimensional electrophoresis which revealed extensive protein thiol oxidation in response to CdCl2 treatment but thiol reduction in response to NaAsO2. Two dimensional electrophoresis analyses showed that the intensity of some protein spots was enhanced on treatment as judged by SameSpots image analysis software. In addition, some spots showed decreased IAF fluorescence suggesting thiol oxidation. Selected spots were excised and tryptic digested for identification by MALDI-TOF/TOF MS. Twenty unique T. asahii proteins were identified of which the following proteins were up-regulated in response to NaAsO2: 3-isopropylmalate dehydrogenase, phospholipase B, alanine-glyoxylate aminotransferase, ATP synthase alpha chain, 20S proteasome beta-type subunit Pre3p and the hypothetical proteins A1Q1_08001, A1Q2_03020, A1Q1_06950, A1Q1_06913. In addition, the following showed decreased thiol-associated fluorescence consistent with thiol oxidation; aconitase; aldehyde reductase I; phosphoglycerate kinase; translation elongation factor 2; heat shock protein 70 and hypothetical protein A1Q2_04745. Some proteins showed both increase in abundance coupled with decrease in IAF fluorescence; 3-hydroxyisobutyryl-CoA hydrolase; homoserine dehydrogenase Hom6 and hypothetical proteins A1Q2_03020 and A1Q1_00754. Targets implicated in redox response included 10 unique metabolic enzymes, heat shock proteins, a component of the 20S proteasome and translation elongation factor 2. These data

  13. 养殖日本鳗鲡腐皮病真菌性病原的分离与鉴定%ISOLATION AND IDENTIFICATION OF FUNGAL PATHOGEN FROM DERMAL ULCERATION DISEASE ON CULTURED ANGUILLA JAPONICA

    Institute of Scientific and Technical Information of China (English)

    曾占壮; 樊海平; 卓玉琛; 吴斌; 张新艳; 陈灵

    2011-01-01

    In recent years, dermal ulceration disease is one of the most serious diseases on cultured Japanese eels (An-guilla japonica), which occurs widely, spreads quickly and has caused great expense through the winter. In the beginning, the grume of the diseased eels are hyperplastic and then broken off. Following the evolvement of the illness, the derma is bareness and the muscle is necrotic. Eventually, the derma and the muscle are rotted.The isolation and identification of the fungal pathogen of this disease was studied. The fungal strain Js80122 was isolated from diseased eels by cultured on kernels of wheat. Strain Js80122 was confirmed as the causative pathogen of the dermal ulceration disease by artificial infection tests, which lasted for 2 weeks. In these tests, healthy eels were infected with four kinds of different methods, namely, injected with spores (0.3 mL/ind.) on dorsal muscle, marinated with 3 dish of culture after ravaged, daubed with spores(1.0x108 cell/mL)on wound and injected with spores and bacteria (0.3 mL/ind.) on dorsal muscle. The results showed that dermal ulceration disease could be recurred well on the experimental eels by any infection method; the symptom and process were similar to the naturally diseased eels. During the course of the artificial infection tests, the mortality were up to 100% in the group injected with spores (5.0x107 cell/mL) and bacteria (5.0x107CFU/mL) on dorsal muscle, 80% in the group injected with spores (l.OxlO8 cell/mL) on dorsal muscle, 60% in the group daubed with spores on wound, 20% in the group marinated with culture after ravaged, respectively. Observation on the morphology and life history of strain Js80122 cultured on slide and cover glass showed that strain Js80122 was the filamentous fungi and could grow well at 15℃, 20℃ and 25℃. Its hyphae were non-aseptate with plentiful branches, the reproductive modes were asexual and sexual. The asexual structure of Js80122 could be well produced at 20℃ or 25

  14. Identification of a New Class of Antifungals Targeting the Synthesis of Fungal Sphingolipids

    Science.gov (United States)

    Mor, Visesato; Rella, Antonella; Farnoud, Amir M.; Singh, Ashutosh; Munshi, Mansa; Bryan, Arielle; Naseem, Shamoon; Konopka, James B.; Ojima, Iwao; Bullesbach, Erika; Ashbaugh, Alan; Linke, Michael J.; Cushion, Melanie; Collins, Margaret; Ananthula, Hari Krishna; Sallans, Larry; Desai, Pankaj B.; Wiederhold, Nathan P.; Fothergill, Annette W.; Kirkpatrick, William R.; Patterson, Thomas; Wong, Lai Hong; Sinha, Sunita; Giaever, Guri; Nislow, Corey; Flaherty, Patrick; Pan, Xuewen; Cesar, Gabriele Vargas; de Melo Tavares, Patricia; Frases, Susana; Miranda, Kildare; Rodrigues, Marcio L.; Luberto, Chiara; Nimrichter, Leonardo

    2015-01-01

    ABSTRACT Recent estimates suggest that >300 million people are afflicted by serious fungal infections worldwide. Current antifungal drugs are static and toxic and/or have a narrow spectrum of activity. Thus, there is an urgent need for the development of new antifungal drugs. The fungal sphingolipid glucosylceramide (GlcCer) is critical in promoting virulence of a variety of human-pathogenic fungi. In this study, we screened a synthetic drug library for compounds that target the synthesis of fungal, but not mammalian, GlcCer and found two compounds [N′-(3-bromo-4-hydroxybenzylidene)-2-methylbenzohydrazide (BHBM) and its derivative, 3-bromo-N′-(3-bromo-4-hydroxybenzylidene) benzohydrazide (D0)] that were highly effective in vitro and in vivo against several pathogenic fungi. BHBM and D0 were well tolerated in animals and are highly synergistic or additive to current antifungals. BHBM and D0 significantly affected fungal cell morphology and resulted in the accumulation of intracellular vesicles. Deep-sequencing analysis of drug-resistant mutants revealed that four protein products, encoded by genes APL5, COS111, MKK1, and STE2, which are involved in vesicular transport and cell cycle progression, are targeted by BHBM. PMID:26106079

  15. Candida Infections: An Update on Host Immune Defenses and Anti-Fungal Drugs

    Directory of Open Access Journals (Sweden)

    Ning Gao

    2016-04-01

    Full Text Available Infections by fungal pathogens such as Candida albicans and non-albicans Candida species are becoming increasing prevalent in the human population. Such pathogens cause life-threatening diseases with high mortality, particularly in immunocompromised patients. Host defenses against fungal infections are provided by an exquisite interplay between innate and adaptive immune responses. However, effective anti-fungal agents for Candida infections are limited, and fungal drug resistance is a significant treatment challenge. In this review, we summarize the current understanding of host–fungal interactions, discuss the modes action of anti-fungal drugs, explore host defense mechanisms, and define the new challenges for treating Candida infections.

  16. 真菌性尿路感染的病原菌分布与药物敏感性特点分析%Pathogen distribution and drug susceptibility analysis of fungal urinary tract infection

    Institute of Scientific and Technical Information of China (English)

    孙伟; 苏建荣

    2014-01-01

    Objective To investigate the pathogen distribution and drug susceptibility of fungal urinary tract infection in this hospital .Methods During Jan .2013 and May .2014 ,10 μL clean middle urine samples was taken for common bacteria or fungi cultivation ,and fungal urinary tract infection was diagnosed when the concentration of fun‐gus were more than 104 cfu/mL .Pure colonies of positive specimens were inoculated to CHROM agar medium to i‐dentify the definite species ,meanwhile ATB‐FUNGUS 3 reagent was used to determine drug susceptibility . Results The total of 507 fungi isolated from sterile urine were Candida spp ,including 267 strains Candida albicans (52 .7% ) ,150 strains of Candida glabrata(29 .6% ) ,55 strains of Candida tropicalis (10 .8% ) and 35 strains of other Candida(6 .9% ) .All the strains were susceptible to amphotericin B .Most Candida albicans were susceptible to azoles antibacterials .While Candida glabrata and Candida tropicalis were less susceptible to azoles antibacteri‐als .Conclusion Pathogen surveillance might be important to early diagnosis and anti‐fungus therapy to improve ther‐apeutic effects .%目的:分析引起真菌性尿路感染的病原菌分布和药敏特点。方法收集2013年1月至2014年5月北京友谊医院各临床科室送检的无菌留取清洁中段尿行普通细菌培养或真菌培养,定量接种10μL进行培养,≥104 cfu/mL判断为真菌性尿路感染;阳性标本纯菌落接种至科玛嘉显色培养基进行菌种鉴定,同时ATB‐FUNGUS 3试剂进行药敏测定。结果引起真菌性尿路感染的507株均为念珠菌,其中白色念珠菌为主要病原菌,占52.7%,其次为光滑念珠菌(29.6%)、热带念珠菌(10.8%)、其他念珠菌(6.9%)。所有菌株对两性霉素B敏感,白色念珠菌对常用抗真菌药物敏感性最高,均在90%以上,而光滑念珠菌和热带念珠菌对唑类耐药百分比较高。结论在临

  17. Fungal infections in neutropenic cancer patients

    International Nuclear Information System (INIS)

    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)

  18. The Mormon cricket, an old threat in modern day western USA:A search for fungal pathogens%美国西部重要害虫摩门螽斯病原真菌的研究

    Institute of Scientific and Technical Information of China (English)

    唐诺德·罗伯茨; Drauzio E N Rangel; Chad A Keyser; Helen G Bignayan; Seth J Dettenmaier; Everton K K Fernandes; Mark P Miller; Edward W Evans

    2007-01-01

    The Mormon cricket (MC),Anabrus simplex (Orthoptera:Tettigoniidae),has a long and negative history with agriculture in the western states of the USA where MC often migrates in large groups and causes significant damage to forage plants and cultivated crops.In this review, virulence to MC of isolates of the insect-pathogenic fungus Metarhizium anisopliae varieties acridum and anisopliae were compared in an effort to identify isolates with promise for use as MC biological control agents.All of the isolates tested induced 100% or nearly 100% mortality by six days post application of the fungal conidia.Searches for new Metarhizium isolates with high heat and UV-B tolerance included isolation fungi from field-caught MC and grasshopper after they died in the laboratory and culturing fungi from soil samples collected from numerous western USA sites.The survey was preceded by development of a dodine based selective medium that,at 0.002% active ingredient,permitted growth of M.anisopliae var.acridum,but inhibited most contaminating fungi.The M.anisopliae var.acridum isolates examined to date have much higher tolerance to heat and UV-B irradiation than M.anisopliae var.anisopliae isolates,and this may be critical to successful field applications.The variety acridum has not yet been found in the USA,so our search for such isolates continues.Several new M.anisopliae var.anisopliae and Beauveria spp.were found,and the Metarhizium isolates are being characterized as to stress tolerance and virulence to insects.Characterization includes comparisons of new and pre-existing Metarhizium isolates by amplified fragment-length polymorphism (AFLP) analysis.Finally, experiments on MC developmental biology were conducted to gather data needed to develop a degree day model and to establish laboratory colonies of MC.

  19. 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. PMID:26646287

  20. 宏基因组学与动物病原微生物检测%Metagenome and detection of animal microbial pathogens

    Institute of Scientific and Technical Information of China (English)

    吴旧生; 王鹏歧; 刘月环

    2014-01-01

    宏基因组学( metagenome)是直接从土壤、海水、人及动物胃肠道、口腔、呼吸道、皮肤等环境中获取样品DNA,利用载体将其克隆到替代宿主细胞中构建宏基因文库,以高通量检测为主要技术来研究特定环境中全部微生物的基因组及筛选活性物质和基因的新兴学科。利用宏基因组学技术不仅能够有效地检测特定环境的微生物群落结构,扩展了微生物资源的利用空间,发展了新兴的高通量检测技术,丰富了生物信息学内容。基于宏基因组学研究方法在环境微生物研究中的优势,对近年来相关领域、方法及其在人及动物病原微生物研究中的应用进行综述,以期将此方法用于实验动物病原微生物的调查分析及动物疫情、生物安全的监测。%Metagenomics ( metagenome) obtained all the microorganisms genome in specific biological environment from DNA samples directly from soil, water and skin, body cavity of human and animals.The metagenomic library was constructed by cloning them into alternative host cells using the vector, which is a discipline of screening new active substances and new genes by high-throughput sequencing.Therefore,using metagenomics not only can effectively detect the composition of microbial community of specific environment,but also greatly expanded the utilize the space of the microbial resources, developed of the next sequencing, enriched the content of bioinformatics. Based on the advantages of metagenomics,we summarized the major advances of metagenomics in human and animal pathogenic microorganisms in recent years,which might be used for the investigation and analysis of microbial pathogens of laboratory animal, animal epidemic monitoring and diagnosis of biological safety.

  1. Metagenome and detection of animal microbial pathogens%宏基因组学与动物病原微生物检测

    Institute of Scientific and Technical Information of China (English)

    吴旧生; 王鹏歧; 刘月环

    2014-01-01

    宏基因组学( metagenome)是直接从土壤、海水、人及动物胃肠道、口腔、呼吸道、皮肤等环境中获取样品DNA,利用载体将其克隆到替代宿主细胞中构建宏基因文库,以高通量检测为主要技术来研究特定环境中全部微生物的基因组及筛选活性物质和基因的新兴学科。利用宏基因组学技术不仅能够有效地检测特定环境的微生物群落结构,扩展了微生物资源的利用空间,发展了新兴的高通量检测技术,丰富了生物信息学内容。基于宏基因组学研究方法在环境微生物研究中的优势,对近年来相关领域、方法及其在人及动物病原微生物研究中的应用进行综述,以期将此方法用于实验动物病原微生物的调查分析及动物疫情、生物安全的监测。%Metagenomics ( metagenome) obtained all the microorganisms genome in specific biological environment from DNA samples directly from soil, water and skin, body cavity of human and animals.The metagenomic library was constructed by cloning them into alternative host cells using the vector, which is a discipline of screening new active substances and new genes by high-throughput sequencing.Therefore,using metagenomics not only can effectively detect the composition of microbial community of specific environment,but also greatly expanded the utilize the space of the microbial resources, developed of the next sequencing, enriched the content of bioinformatics. Based on the advantages of metagenomics,we summarized the major advances of metagenomics in human and animal pathogenic microorganisms in recent years,which might be used for the investigation and analysis of microbial pathogens of laboratory animal, animal epidemic monitoring and diagnosis of biological safety.

  2. Comparative genomics of multidrug resistance-encoding IncA/C plasmids from commensal and pathogenic Escherichia coli from multiple animal sources.

    Directory of Open Access Journals (Sweden)

    Claudia Fernández-Alarcón

    Full Text Available Incompatibility group A/C (IncA/C plasmids have received recent attention for their broad host range and ability to confer resistance to multiple antimicrobial agents. Due to the potential spread of multidrug resistance (MDR phenotypes from foodborne pathogens to human pathogens, the dissemination of these plasmids represents a public health risk. In this study, four animal-source IncA/C plasmids isolated from Escherichia coli were sequenced and analyzed, including isolates from commercial dairy cows, pigs and turkeys in the U.S. and Chile. These plasmids were initially selected because they either contained the floR and tetA genes encoding for florfenicol and tetracycline resistance, respectively, and/or the bla(CMY-2 gene encoding for extended spectrum β-lactamase resistance. Overall, sequence analysis revealed that each of the four plasmids retained a remarkably stable and conserved backbone sequence, with differences observed primarily within their accessory regions, which presumably have evolved via horizontal gene transfer events involving multiple modules. Comparison of these plasmids with other available IncA/C plasmid sequences further defined the core and accessory elements of these plasmids in E. coli and Salmonella. Our results suggest that the bla(CMY-2 plasmid lineage appears to have derived from an ancestral IncA/C plasmid type harboring floR-tetAR-strAB and Tn21-like accessory modules. Evidence is mounting that IncA/C plasmids are widespread among enteric bacteria of production animals and these emergent plasmids have flexibility in their acquisition of MDR-encoding modules, necessitating further study to understand the evolutionary mechanisms involved in their dissemination and stability in bacterial populations.

  3. Diversity of aquatic Pseudomonas species and their activity against the fish pathogenic oomycete Saprolegnia

    OpenAIRE

    Yiying Liu; Elzbieta Rzeszutek; Menno van der Voort; Cheng-Hsuan Wu; Even Thoen; Ida Skaar; Vincent Bulone; Dorrestein, Pieter C.; Raaijmakers, Jos M.; Irene de Bruijn

    2015-01-01

    Emerging fungal and oomycete pathogens are increasingly threatening animals and plants globally. Amongst oomycetes, Saprolegnia species adversely affect wild and cultivated populations of amphibians and fish, leading to substantial reductions in biodiversity and food productivity. With the ban of several chemical control measures, new sustainable methods are needed to mitigate Saprolegnia infections in aquaculture. Here, PhyloChip-based community analyses showed that the Pseudomonadales, part...

  4. Pathogenesis and CT findings of primary pulmonary fungal infection

    International Nuclear Information System (INIS)

    Primary pulmonary fungal infection occurs in immunocompetent hosts without underlying lesions. In the clinic, the most common pathogenic fungal are cryptococcus (cryptococcus neoformans) and aspergillus. Due to the increased incidence of the disease, the misdiagnosis rate and mortality, it has great clinical importance to study the clinical and CT features. By reviewing the recent domestic and overseas literatures, the definition, pathogenesis, clinical manifestations. clinical diagnosis, and CT findings of primary pulmonary fungal infection are summarized. (authors)

  5. Initial fungal effector production is mediated by early endosome motility

    OpenAIRE

    Higuchi, Yujiro

    2015-01-01

    Fungal plant pathogenicity is facilitated by effector proteins that are specifically expressed during infection and are responsible for suppressing plant defense mechanisms. Recent studies have elucidated the detailed molecular mechanisms of effector action throughout fungal infection. However, little is known about the trafficking and secretion of effectors in fungal hyphae during the initial stage of infection. Using state-of-the-art microscopy we have demonstrated that early endosome (EE) ...

  6. Identification and analysis of cation channel homologues in human pathogenic fungi.

    Directory of Open Access Journals (Sweden)

    David L Prole

    Full Text Available Fungi are major causes of human, animal and plant disease. Human fungal infections can be fatal, but there are limited options for therapy, and resistance to commonly used anti-fungal drugs is widespread. The genomes of many fungi have recently been sequenced, allowing identification of proteins that may become targets for novel therapies. We examined the genomes of human fungal pathogens for genes encoding homologues of cation channels, which are prominent drug targets. Many of the fungal genomes examined contain genes encoding homologues of potassium (K(+, calcium (Ca(2+ and transient receptor potential (Trp channels, but not sodium (Na(+ channels or ligand-gated channels. Some fungal genomes contain multiple genes encoding homologues of K(+ and Trp channel subunits, and genes encoding novel homologues of voltage-gated K(v channel subunits are found in Cryptococcus spp. Only a single gene encoding a homologue of a plasma membrane Ca(2+ channel was identified in the genome of each pathogenic fungus examined. These homologues are similar to the Cch1 Ca(2+ channel of Saccharomyces cerevisiae. The genomes of Aspergillus spp. and Cryptococcus spp., but not those of S. cerevisiae or the other pathogenic fungi examined, also encode homologues of the mitochondrial Ca(2+ uniporter (MCU. In contrast to humans, which express many K(+, Ca(2+ and Trp channels, the genomes of pathogenic fungi encode only very small numbers of K(+, Ca(2+ and Trp channel homologues. Furthermore, the sequences of fungal K(+, Ca(2+, Trp and MCU channels differ from those of human channels in regions that suggest differences in regulation and susceptibility to drugs.

  7. Amphibians acquire resistance to live and dead fungus overcoming fungal immunosuppression.

    Science.gov (United States)

    McMahon, Taegan A; Sears, Brittany F; Venesky, Matthew D; Bessler, Scott M; Brown, Jenise M; Deutsch, Kaitlin; Halstead, Neal T; Lentz, Garrett; Tenouri, Nadia; Young, Suzanne; Civitello, David J; Ortega, Nicole; Fites, J Scott; Reinert, Laura K; Rollins-Smith, Louise A; Raffel, Thomas R; Rohr, Jason R

    2014-07-10

    Emerging fungal pathogens pose a greater threat to biodiversity than any other parasitic group, causing declines of many taxa, including bats, corals, bees, snakes and amphibians. Currently, there is little evidence that wild animals can acquire resistance to these pathogens. Batrachochytrium dendrobatidis is a pathogenic fungus implicated in the recent global decline of amphibians. Here we demonstrate that three species of amphibians can acquire behavioural or immunological resistance to B. dendrobatidis. Frogs learned to avoid the fungus after just one B. dendrobatidis exposure and temperature-induced clearance. In subsequent experiments in which B. dendrobatidis avoidance was prevented, the number of previous exposures was a negative predictor of B. dendrobatidis burden on frogs and B. dendrobatidis-induced mortality, and was a positive predictor of lymphocyte abundance and proliferation. These results suggest that amphibians can acquire immunity to B. dendrobatidis that overcomes pathogen-induced immunosuppression and increases their survival. Importantly, exposure to dead fungus induced a similar magnitude of acquired resistance as exposure to live fungus. Exposure of frogs to B. dendrobatidis antigens might offer a practical way to protect pathogen-naive amphibians and facilitate the reintroduction of amphibians to locations in the wild where B. dendrobatidis persists. Moreover, given the conserved nature of vertebrate immune responses to fungi and the fact that many animals are capable of learning to avoid natural enemies, these results offer hope that other wild animal taxa threatened by invasive fungi might be rescued by management approaches based on herd immunity.

  8. High prevalence of pathogenicLeptospira in wild and domesticated animals in an endemic area of China

    Institute of Scientific and Technical Information of China (English)

    Wang Yalin; Zeng Lingbing; Yang Hongliang; Xu Jianmin; Zhang Xiangyan; Guo Xiaokui; Pal Utpal; Qin Jinhong

    2011-01-01

    Objective:To assess the prevalence ofLeptospira detected in wildlife and domesticated animals in Jiangxi Province, China, in2009.Methods:Urine samples from 28 buffaloes and kidney samples from50 pigs,50 dogs and38 rats were collected from Fuliang and Shangrao County, Jiangxi Province, China, in October2009. Polymerase chain reaction(PCR) and culture analyses were used to detectLeptospira. The cultured isolates were typed using the microscopic agglutination test (MAT).Results:The results showed that rats potentially serve as the main reservoir of leptospiral infection, followed by dogs. Although16% of rats (6/38) were positive using culture analysis, PCR analysis using the diagnostic primersG1/G2 and B64I/B64II or lipL32 showed identification as50% and24%, respectively, of the rat samples as positive for the presence of leptospiralDNA.Conclusions:PCR-based detection of leptospiralDNA in infected kidney tissues of reservoirs is more efficient when usingG1/G2 primers thanlipL32 primers. However, the latter primers have a potential application for detection in urine samples. The alarmingly high prevalence of leptospiralDNAin the wild rat population near human habitation underscores the utility of routineLeptospira surveillance, preferably usingPCR methods, which are more sensitive than traditional culture-based methods.

  9. 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

  10. Fundación del primer bioterio MPF funcional de Colombia Foundation of a functional murine pathogen free animal facility in Colombia

    Directory of Open Access Journals (Sweden)

    Ómar Vesga

    2003-02-01

    Full Text Available Cualquier investigación donde se experimente con modelos animales exige que el estado microbiológico y genético de los mismos sea definido desde el principio y verificado periódicamente para garantizar la fiabilidad y certeza de los datos. Buscando producir ratones libres de patógenos murinos en Colombia, se importaron 173 reproductores no emparentados suizos albinos de la cepa ICR que se hospedaron bajo condiciones protocolizadas de aislamiento microbiológico en el Bioterio MPF de la Facultad de Medicina de la Universidad de Antioquia. Tras dos años de funcionamiento ininterrumpido, el control microbiológico demostró que los progenitores mantuvieron inalterada la flora con la cual fueron exportados a Colombia, que sus crías portan flora murina idéntica, y que la misma corresponde a la exigida internacionalmente. Diversas pruebas a la integridad de la barrera microbiológica condujeron a la detección y erradicación de un brote infeccioso por Parvovirus murino. El control reproductivo permitió mantener intacta la heterocigocidad de la cepa, denominada Udea:ICR(CD-1. In order to guarantee the accuracy of the data, experimentation with animal models requires well defined microbiological and genetic statuses with periodical verification. To produce murine pathogen free mice, an outbreeding program was set up by importing 173 non-related Swiss albino ICR breeders that were hosted under strict conditions of microbiological isolation in the animal facilities of the University of Antioquia Medical Faculty. After two years of uninterrupted reproduction, microbiological control demonstrated unaltered murine flora for both parents and offspring, the same with which original breeders were dispatched to Colombia, complying with current international standards. An outbreak of Murine Parvovirus (MPV was timely detected and erradicated thanks to strict testing of microbiological barriers. The breeding program allowed the production of animals free

  11. Effect of anti-glycosphingolipid monoclonal antibodies in pathogenic fungal growth and differentiation. Characterization of monoclonal antibody MEST-3 directed to Manpα1→3Manpα1→2IPC

    Directory of Open Access Journals (Sweden)

    Straus Anita H

    2010-02-01

    Full Text Available Abstract Background Studies carried out during the 1990's demonstrated the presence of fungal glycoinositol phosphorylceramides (GIPCs with unique structures, some of them showed reactivity with sera of patients with histoplasmosis, paracoccidioidomycosis or aspergillosis. It was also observed that fungal GIPCs were able to inhibit T lymphocyte proliferation "in vitro", and studies regarding the importance of these molecules to fungal survival showed that many species of fungi are vulnerable to inhibitors of sphingolipid biosynthesis. Results In this paper, we describe a detailed characterization of an IgG2a monoclonal antibody (mAb, termed MEST-3, directed to the Paracoccidioides brasiliensis glycolipid antigen Pb-2 (Manpα1→3Manpα1→2IPC. mAb MEST-3 also recognizes GIPCs bearing the same structure in other fungi. Studies performed on fungal cultures clearly showed the strong inhibitory activity of MEST-3 on differentiation and colony formation of Paracoccidioides brasiliensis, Histoplasma capsulatum and Sporothrix schenckii. Similar inhibitory results were observed when these fungi where incubated with a different mAb, which recognizes GIPCs bearing terminal residues of β-D-galactofuranose linked to mannose (mAb MEST-1. On the other hand, mAb MEST-2 specifically directed to fungal glucosylceramide (GlcCer was able to promote only a weak inhibition on fungal differentiation and colony formation. Conclusions These results strongly suggest that mAbs directed to specific glycosphingolipids are able to interfere on fungal growth and differentiation. Thus, studies on surface distribution of GIPCs in yeast and mycelium forms of fungi may yield valuable information regarding the relevance of glycosphingolipids in processes of fungal growth, morphological transition and infectivity.

  12. Inductive effects of fungal pathogens of American Ginseng and Ginseng on chitinase and cellulase of antigonistic actinomycetes%西洋参和人参病原真菌菌体对放线菌2种水解酶的诱导

    Institute of Scientific and Technical Information of China (English)

    于妍华; 薛泉宏; 唐明

    2011-01-01

    【目的】研究特定拮抗放线菌对西洋参人参土传病害病原真菌的接触抗菌机理。【方法】以5株西洋参、人参土传病害病原真菌菌体为惟一碳源,用液体培养及3,5二硝基水杨酸(DNS)法研究5株供试病原真菌对9株拮抗放线菌几丁质酶和纤维素酶合成的诱导作用;采用搭片法,观察9株拮抗放线菌与5株供试病原真菌菌丝间的相互作用。【结果】①以5株病原真菌菌体为惟一碳源时,可诱导9株拮抗放线菌合成几丁质酶和纤维素酶;9株放线菌的几丁质酶和纤维素酶活性分别为7.17~11.58和6.14~21.20 U,其中西洋参恶疫霉菌体对9株放线%【Objective】 Inhibitory mechanism of antigonistic actimomycetes fighting against fungal pathogens of soil-borne disease in American Ginseng and Ginseng was studied.【Method】 The inductiveness was assessed by the activity of chitinase and cellulase,which were induced from 9 strains of antigonistic actinomycete by using 5 dried strains of fungal pathogens of American Ginseng and Ginseng as C-source in liquid culture medium and DNS measurement,and the mutual effects were observed between antigonistic actinomycetes and fungal pathogens of American Ginseng and Ginseng through the method of building pieces on plate.【Result】 ①The activity of chitinase and cellulase,which was mainly distributed among 7.17-11.58 and 6.14-21.20 U,respectively,differed from 9 strains of antigonistic antinomycete induced from 5 strains of fungal pathogen of American Ginseng and Ginseng.The powder of Phytophthora cactorum could induce antigonistic actinomycetes to produce much more chitinase and cellulase.②The mutural effects between mycelia of Act11,Act13,Act24 and Cylindrocarpon destructans,Cylindrocarpon sp.,such as winding and decomposition,were observed distinctively.【Conclusion】 The mycelia of 5 strains of fungal pathogen of American Ginseng and Ginseng could induce 9 strains of antigonistic actinomycete

  13. Pre- and postharvest fungal apple diseases

    Science.gov (United States)

    The domesticated apple (Malus domestica) is the most significant pome fruit grown and consumed worldwide. China is the largest producer followed by the United States on a global scale. However, fungal plant pathogens cause significant economic losses in the field and in storage which negatively impa...

  14. Rapid Detection of Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    David Perlin

    2005-08-14

    Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents. Many select agents are highly transmissible in the early stages of disease, and it is critical to identify infected patients and limit the risk to the remainder of the population and to stem potential panic in the general population. Nucleic acid-based molecular approaches for identification overcome many of the deficiencies associated with conventional culture methods by exploiting both large- and small-scale genomic differences between organisms. PCR-based amplification of highly conserved ribosomal RNA (rRNA) genes, intergenic sequences, and specific toxin genes is currently the most reliable approach for bacterial, fungal and many viral pathogenic agents. When combined with fluorescence-based oligonucleotide detection systems, this approach provides real-time, quantitative, high fidelity analysis capable of single nucleotide allelic discrimination (4). These probe systems offer rapid turn around time (<2 h) and are suitable for high throughput, automated multiplex operations that are critical for clinical diagnostic laboratories. In this pilot program, we have used molecular beacon technology invented at the Public health Research Institute to develop a new generation of molecular probes to rapidly detect important agents of infectious diseases. We have also developed protocols to rapidly extract nucleic acids from a variety of clinical specimen including and blood and tissue to for detection in the molecular assays. This work represented a cooperative research development program between the Kramer-Tyagi/Perlin labs on probe development

  15. 3种柑橘病原真菌对苯醚菌酯和苯醚甲环唑敏感基线研究%Baseline sensitivities of three fungal pathogens of citrus to strobilurin fungicide and difenoconazole

    Institute of Scientific and Technical Information of China (English)

    侯欣; 陈国庆; 王兴红; 朱丽; 李红叶

    2013-01-01

    Melanose (Diaporthe citri),black spot (Guignardia citricarpa) and greasy spot (Mycospharella citri) of citrus have been becoming more and more serious and widespread,causing significant losses to the Chinese citrus industry by reducing yield and fruit quality in recent years.Although the improvement of cultural practices has the positive effect,application of fungicides is still the primary and effective means to control these diseases.Difenoconazole(belong to 14α-demethlylation inhibitors,DMIs) is a fungicide recently registered for use on citrus in China.ZJ0712 (belong to strobilurin,QoI),developed independently by our country,has a high potential in controlling citrus fungal diseases.The objective of this study was to establish the baseline sensitivity of these citrus fungal pathogens to these fungicides prior to their widespread use. Forty-eight single-spore strains of D.citri,46 strains of G.citricarpa and 50 strains of M.citri were collected from main citrus-producing regions in China.The effective dose to reduce mycelial growth or spore germination by 50% (EC50 values) of each strain was determined by using eight different concentrations of fungicides.The results demonstrated that the baseline sensitivities for mycelial growth of D.citri,G.citricarpa and M.citri to ZJ0712 were 0.003,0.011 and 0.035 μg/mL,respectively; to difenoconazole were 0.149,0.008 and 0.970 μg/mL,respectively.The baseline sensitivities for conidial germination of D.citri to ZJ0712 was 0.001 μg/mL,but > 25 μg/mL to difenoconazole. These results above indicated that the populations of D.citri,G.citricarpa and M.citri were sensitive to ZJ0712,and the populations of G.citricarpa and M.citri were sensitive to difenoconazole,implying widely potential usage of these fungicides in controlling the diseases above.Determination of the baseline sensitivities of D.citri,G.citricarpa and M.citri should also facilitate the detection and verification of pathogen resistance development to ZJ0712

  16. Risk ranking of pathogens in ready-to-eat unprocessed foods of non-animal origin (FoNAO) in the EU: Initial evaluation using outbreak data (2007-2011)

    DEFF Research Database (Denmark)

    Da Silva Felício, M. T.; Hald, Tine; Liebana, E.;

    2015-01-01

    Foods of non-animal origin (FoNAO) are consumed in a variety of forms, being a major component of almost all meals. These food types have the potential to be associated with large outbreaks as seen in 2011 associated with VTEC O104. In order to identify and rank specific food/pathogen combination...

  17. Foster carers influence brood pathogen resistance in ants.

    Science.gov (United States)

    Purcell, Jessica; Chapuisat, Michel

    2014-10-01

    Social organisms face a high risk of epidemics, and respond to this threat by combining efficient individual and collective defences against pathogens. An intriguing and little studied feature of social animals is that individual pathogen resistance may depend not only on genetic or maternal factors, but also on the social environment during development. Here, we used a cross-fostering experiment to investigate whether the pathogen resistance of individual ant workers was shaped by their own colony of origin or by the colony of origin of their carers. The origin of care-giving workers significantly influenced the ability of newly eclosed cross-fostered Formica selysi workers to resist the fungal entomopathogen Beauveria bassiana. In particular, carers that were more resistant to the fungal entomopathogen reared more resistant workers. This effect occurred in the absence of post-infection social interactions, such as trophallaxis and allogrooming. The colony of origin of eggs significantly influenced the survival of the resulting individuals in both control and pathogen treatments. There was no significant effect of the social organization (i.e. whether colonies contain a single or multiple queens) of the colony of origin of either carers or eggs. Our experiment reveals that social interactions during development play a central role in moulding the resistance of emerging workers. PMID:25143036

  18. Comparison of Six DNA Extraction Methods for Recovery of Fungal DNA as Assessed by Quantitative PCR

    OpenAIRE

    Fredricks, David N.; Smith, Caitlin; Meier, Amalia

    2005-01-01

    The detection of fungal pathogens in clinical samples by PCR requires the use of extraction methods that efficiently lyse fungal cells and recover DNA suitable for amplification. We used quantitative PCR assays to measure the recovery of DNA from two important fungal pathogens subjected to six DNA extraction methods. Aspergillus fumigatus conidia or Candida albicans yeast cells were added to bronchoalveolar lavage fluid and subjected to DNA extraction in order to assess the recovery of DNA fr...

  19. Role And Relevance Of Mast Cells In Fungal Infections

    Directory of Open Access Journals (Sweden)

    Rohit eSaluja

    2012-06-01

    Full Text Available In addition to their detrimental role in allergic diseases, mast cells (MCs are well known to be important cells of the innate immune system. In the last decade, they have been shown to contribute significantly to optimal host defense against numerous pathogens including parasites, bacteria, and viruses. The contribution of MCs to the immune responses in fungal infections, however, is largely unknown. In this review, we first discuss key features of mast cell responses to pathogens in general and then summarize the current knowledge on the function of MCs in the defense against fungal pathogens. We especially focus on the potential and proven mechanisms by which MC can detect fungal infections and on possible MC effector mechanisms in protecting from fungal infections.

  20. Use of isotopes for research and control of vectors of animal diseases, host-pathogen relationships and the environmental impact of control procedures

    International Nuclear Information System (INIS)

    Full text: To cope with the world-wide problems of famine, malnutrition and environmental pollution it is imperative that all techniques and resources for the protection of animals and plants be utilized. As an example, nagana alone (animal trypanosomiasis) profoundly affects socioeconomic development in Africa. Its vector, the tsetse fly, is widespread and prevents agricultural development over much of the more than 7 million square kilometres where it is present. The need to control this disease has been emphasized by a mandate from the 1974 World Food Conference of the United Nations. If this disease alone could be eliminated, the cattle population could be increased by at least 120 million head with a resultant yearly increase in meat production of 1.5 million tons having a value totalling 750 million US dollars. The symposium was convened to discuss the various research and control aspects of nagana and related diseases and was the first of its kind to be convened by the sponsoring organizations The symposium amply demonstrated the value and usefulness of isotopes in the research and control of vectors of animal diseases, the elucidation of host-pathogen relationships and the degradation of pesticides. The symposium received an enthusiastic response, reflected in the large number of papers presented, which covered a variety of topics, including the sterile insect technique (SIT) as applied to tsetse flies. Several papers were presented covering its different aspects such as mass-rearing, sterility induction, ecology, behaviour and computer modelling. Other topics emphasized were pathogenesis and immunology of vector borne diseases such as trypanosomiasis, anaplasmosis, babesiosis and leishmaniasis. Also included were presentations on insect repellents and the biotransformation and degradation of labelled pesticides. The technical sessions began with 3 review papers, one on the FAO Animal Health Division's field research on tsetse flies, the second on the

  1. 非移植患者侵袭性真菌病165例病原谱和易感因素分析%Analysis of pathogenic spectrum and risk factors in 165 non-transplant patients with invasive fungal disease

    Institute of Scientific and Technical Information of China (English)

    闫晓培; 宗峰; 赵新云; 孙凯; 金琳羚; 王晶晶; 孔辉; 解卫平

    2014-01-01

    infection in patients with hematopathy/malignant tumors (fourth edition,2013),diagnostic criteria and treatment principle of invasive pulmonary fungal infection (draft,2006).Results Invasive fungal disease was mostly diagnosed in therespiratory department (31.5 %).The maj or pathogens were cryptococcus (48.3 %),aspergillus (31.7 %)and followed by mucor (5.9%).The most common symptoms included cough,haemoptysis,and fever.Radiological Findings were non-specific,nodules or opacities being more common as compared to classical aspergilloma,halo sign,and crescent sign.The most common underlying diseases were diabetes(15.8%),chronic obstructive pulmonary disease (13.3 %),and malignant hematological disease(10.3 %).Moreover,66.1% cases of invasive fungal disease were accompanied by one or more risk factors (eg.administration of antibiotics more than 7 days,invasive operations,and therapy with long-term glucocorticoids or immunosuppressant drugs).The mortality of invasive fungal disease with more than 2 risk factors was 10.6%.Conclusions The most common pathogens of invasive fungal disease in non-transplant patients were cryptococcus,aspergillus and mucor.The lung and the brain were the mostly involved organs.Compared to cryptococcus,invasive fungal disease caused by other fungal pathogens mainly occurred in patients with serious underlying diseases and risk factors.

  2. Transcriptomics of the rice blast fungus Magnaporthe oryzae in response to the bacterial antagonist Lysobacter enzymogenes reveals candidate fungal defense response genes.

    Directory of Open Access Journals (Sweden)

    Sandra M Mathioni

    Full Text Available Plants and animals have evolved a first line of defense response to pathogens called innate or basal immunity. While basal defenses in these organisms are well studied, there is almost a complete lack of understanding of such systems in fungal species, and more specifically, how they are able to detect and mount a defense response upon pathogen attack. Hence, the goal of the present study was to understand how fungi respond to biotic stress by assessing the transcriptional profile of the rice blast pathogen, Magnaporthe oryzae, when challenged with the bacterial antagonist Lysobacter enzymogenes. Based on microscopic observations of interactions between M. oryzae and wild-type L. enzymogenes strain C3, we selected early and intermediate stages represented by time-points of 3 and 9 hours post-inoculation, respectively, to evaluate the fungal transcriptome using RNA-seq. For comparative purposes, we also challenged the fungus with L. enzymogenes mutant strain DCA, previously demonstrated to be devoid of antifungal activity. A comparison of transcriptional data from fungal interactions with the wild-type bacterial strain C3 and the mutant strain DCA revealed 463 fungal genes that were down-regulated during attack by C3; of these genes, 100 were also found to be up-regulated during the interaction with DCA. Functional categorization of genes in this suite included those with roles in carbohydrate metabolism, cellular transport and stress response. One gene in this suite belongs to the CFEM-domain class of fungal proteins. Another CFEM class protein called PTH11 has been previously characterized, and we found that a deletion in this gene caused advanced lesion development by C3 compared to its growth on the wild-type fungus. We discuss the characterization of this suite of 100 genes with respect to their role in the fungal defense response.

  3. Structure and biological functions of fungal cerebrosides

    Directory of Open Access Journals (Sweden)

    Barreto-Bergter Eliana

    2004-01-01

    Full Text Available Ceramide monohexosides (CMHs, cerebrosides are glycosphingolipids composed of a hydrophobic ceramide linked to one sugar unit. In fungal cells, CMHs are very conserved molecules consisting of a ceramide moiety containing 9-methyl-4,8-sphingadienine in amidic linkage to 2-hydroxyoctadecanoic or 2-hydroxyhexadecanoic acids, and a carbohydrate portion consisting of one residue of glucose or galactose. 9-Methyl 4,8-sphingadienine-containing ceramides are usually glycosylated to form fungal cerebrosides, but the recent description of a ceramide dihexoside (CDH presenting phytosphingosine in Magnaporthe grisea suggests the existence of alternative pathways of ceramide glycosylation in fungal cells. Along with their unique structural characteristics, fungal CMHs have a peculiar subcellular distribution and striking biological properties. In Pseudallescheria boydii, Candida albicans, Cryptococcus neoformans, Aspergillus nidulans, A. fumigatus, and Schizophyllum commune, CMHs are apparently involved in morphological transitions and fungal growth. The elucidation of structural and functional aspects of fungal cerebrosides may therefore contribute to the design of new antifungal agents inhibiting growth and differentiation of pathogenic species.

  4. An evolutionary perspective on zinc uptake by human fungal pathogens†

    Science.gov (United States)

    Wilson, Duncan

    2015-01-01

    The mammalian immune system has evolved sophisticated mechanisms to withhold essential micronutrients from invading pathogens. These processes, collectively known as nutritional immunity serve to limit microbial proliferation and bolster killing of the invader. Successful pathogens, therefore, have developed strategies to counteract nutritional immunity and acquire essential micronutrients in the restrictive environment of the infected host. Here I take advantage of the now large number of sequenced fungal genomes to explore the zinc acquisition strategies of human fungal pathogens and reflect on the evolutionary context of these uptake pathways. PMID:25652414

  5. C. elegans germline-deficient mutants respond to pathogen infection using shared and distinct mechanisms.

    Directory of Open Access Journals (Sweden)

    Michael TeKippe

    Full Text Available Reproduction extracts a cost in resources that organisms are then unable to utilize to deal with a multitude of environmental stressors. In the nematode C. elegans, development of the germline shortens the lifespan of the animal and increases its susceptibility to microbial pathogens. Prior studies have demonstrated germline-deficient nematodes to have increased resistance to gram negative bacteria. We show that germline-deficient strains display increased resistance across a broad range of pathogens including gram positive and gram negative bacteria, and the fungal pathogen Cryptococcus neoformans. Furthermore, we show that the FOXO transcription factor DAF-16, which regulates longevity and immunity in C. elegans, appears to be crucial for maintaining longevity in both wild-type and germline-deficient backgrounds. Our studies indicate that germline-deficient mutants glp-1 and glp-4 respond to pathogen infection using common and different mechanisms that involve the activation of DAF-16.

  6. Effectiveness of irradiation in killing pathogens

    International Nuclear Information System (INIS)

    United States Environmental Protection Agency regulations include gamma ray irradiation of sludge as an approved Process to Further Reduce Pathogens (PFRP) prior to land application. Research at Sandia National Laboratories on pathogen inactivation in sludge by gamma irradiation has demonstrated that the 1 Mrad PFRP dose is capable, by itself, of eliminating bacterial, fungal, and parasitic pathogens from sludge. Gamma irradiation of sludge in conjunction with the required Processes to Significantly Reduce Pathogens (PSRP) should also eliminate the viral hazard from wastewater sludges

  7. FUNGAL ASSOCIATION WITH SESSILE MARINE INVERTEBRATES

    Directory of Open Access Journals (Sweden)

    Oded eYarden

    2014-05-01

    Full Text Available The presence and association of fungi with sessile marine animals such as coral and sponges has been well established, yet information on the extent of diversity of the associated fungi is still in its infancy. Culture- as well as metagenomic- and transcriptomic-based analyses have shown that fungal presence in association with these animals can be dynamic and can include core residents as well as shifts in fungal communities. Evidence for detrimental and beneficial interactions between fungi and their marine hosts is accumulating and current challenges include the elucidation of the chemical and cellular crosstalk between fungi and their associates within the holobionts. The ecological function of fungi in association with sessile marine animals is complex and is founded on a combination of factors such as fungal origin, host health, environmental conditions and the presence of other resident or invasive microorganisms in the host. Based on evidence from the much more studied terrestrial systems, the evaluation of marine animal-fungal symbioses under varying environmental conditions may well prove to be critical in predicting ecosystem response to global change, including effects on the health of sessile marine animals.

  8. Comparative genomics reveals mobile pathogenicity chromosomes in Fusarium

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Li Jun; van der Does, H. C.; Borkovich, Katherine A.; Coleman, Jeffrey J.; Daboussi, Marie-Jose; Di Pietro, Antonio; Dufresne, Marie; Freitag, Michael; Grabherr, Manfred; Henrissat, Bernard; Houterman, Petra M.; Kang, Seogchan; Shim, Won-Bo; Wolochuk, Charles; Xie, Xiaohui; Xu, Jin Rong; Antoniw, John; Baker, Scott E.; Bluhm, Burton H.; Breakspear, Andrew; Brown, Daren W.; Butchko, Robert A.; Chapman, Sinead; Coulson, Richard; Coutinho, Pedro M.; Danchin, Etienne G.; Diener, Andrew; Gale, Liane R.; Gardiner, Donald; Goff, Steven; Hammond-Kossack, Kim; Hilburn, Karen; Hua-Van, Aurelie; Jonkers, Wilfried; Kazan, Kemal; Kodira, Chinnappa D.; Koehrsen, Michael; Kumar, Lokesh; Lee, Yong Hwan; Li, Liande; Manners, John M.; Miranda-Saavedra, Diego; Mukherjee, Mala; Park, Gyungsoon; Park, Jongsun; Park, Sook Young; Proctor, Robert H.; Regev, Aviv; Ruiz-Roldan, M. C.; Sain, Divya; Sakthikumar, Sharadha; Sykes, Sean; Schwartz, David C.; Turgeon, Barbara G.; Wapinski, Ilan; Yoder, Olen; Young, Sarah; Zeng, Qiandong; Zhou, Shiguo; Galagan, James; Cuomo, Christina A.; Kistler, H. Corby; Rep, Martijn

    2010-03-18

    Fusarium species are among the most important phytopathogenic and toxigenic fungi, having significant impact on crop production and animal health. Distinctively, members of the F. oxysporum species complex exhibit wide host range but discontinuously distributed host specificity, reflecting remarkable genetic adaptability. To understand the molecular underpinnings of diverse phenotypic traits and their evolution in Fusarium, we compared the genomes of three economically important and phylogenetically related, yet phenotypically diverse plant-pathogenic species, F. graminearum, F. verticillioides and F. oxysporum f. sp. lycopersici. Our analysis revealed greatly expanded lineage-specific (LS) genomic regions in F. oxysporum that include four entire chromosomes, accounting for more than one-quarter of the genome. LS regions are rich in transposons and genes with distinct evolutionary profiles but related to pathogenicity. Experimentally, we demonstrate for the first time the transfer of two LS chromosomes between strains of F. oxysporum, resulting in the conversion of a non-pathogenic strain into a pathogen. Transfer of LS chromosomes between otherwise genetically isolated strains explains the polyphyletic origin of host specificity and the emergence of new pathogenic lineages in the F. oxysporum species complex, putting the evolution of fungal pathogenicity into a new perspective.

  9. 猕猴桃果实贮藏期主要真菌病害的rDNA-ITS鉴定及序列分析%Molecular Identification and rDNA-ITS Sequence Analysis of Fungal Pathogens in Kiwifruit During Storage

    Institute of Scientific and Technical Information of China (English)

    段爱莉; 雷玉山; 孙翔宇; 高贵田; 赵金梅; 谷留杰

    2013-01-01

    [Objective] The fungal pathogens of ‘China optimal’,‘Haiwode’ and ‘Qinmei’ kiwi fruit that were harvested in Zhouzhi County,Shaanxi Province,were isolated during storage and identified by rDNA-ITS sequences analysis.[Method] With rDNA-ITS analysis and morphological characterization,the species of Fungal pathogens were differentiated and identified.By means of the genetic relationship analysis and multiple comparison analysis of ITS sequences of fungal pathogens,the diversity of intra-species in the pathogens were investigated.[Result] Five strains were identified,e.g.Penicillium,Trichoderma,Alternaria,Mucor and Simplicillium.Penicillium was the dominant species,accounting for 63.3% of the tested strains.And Trichoderma was the second dominant species,accounting for 26.7%.There were little differences in ITS sequences among Trichoderm,approval ratings were 99%.But the differences of ITS sequences between the Penicillium were significant.Such as Penicillium sp.,Penicillium purpurogenum,Penicillium chrysogenum,Penicillium paneum and Penicillium commune.[Conclusion] Penicillium are mainly fungal pathogens of ‘China optimal’,‘Haiwode’ and ‘Qinmei’ kiwifruit that were harvested in Zhouzhi County,Shaanxi Province.The differences of rDNA-ITS sequences between Penicillium are obvious.So,rDNA-ITS sequence between ourtra-species and intra-species have a certain reference value.%[目的]对陕西省周至县猕猴桃主栽品种‘华优’、‘海沃德’及‘秦美’贮藏期霉烂果实中的病原菌进行分离与鉴定,分析比较病原菌rDNA-ITS序列的差异和种内与种间群体分化状况,确定优势菌,为病害防治提供依据.[方法]采用病原菌形态鉴定与rDNA-ITS鉴定相结合的方法,确定引起猕猴桃霉烂的病原菌种类;通过构建系统发育树,分析病原菌种之间的亲缘关系.[结果]从贮藏期霉烂的猕猴桃果实中共分离出30株病原菌,主要为青霉属(Penicillium)、木

  10. A Small Protein Associated with Fungal Energy Metabolism Affects the Virulence of Cryptococcus neoformans in Mammals.

    Science.gov (United States)

    McClelland, Erin E; Ramagopal, Udupi A; Rivera, Johanna; Cox, James; Nakouzi, Antonio; Prabu, Moses M; Almo, Steven C; Casadevall, Arturo

    2016-09-01

    The pathogenic yeast Cryptococcus neoformans causes cryptococcosis, a life-threatening fungal disease. C. neoformans has multiple virulence mechanisms that are non-host specific, induce damage and interfere with immune clearance. Microarray analysis of C. neoformans strains serially passaged in mice associated a small gene (CNAG_02591) with virulence. This gene, hereafter identified as HVA1 (hypervirulence-associated protein 1), encodes a protein that has homologs of unknown function in plant and animal fungi, consistent with a conserved mechanism. Expression of HVA1 was negatively correlated with virulence and was reduced in vitro and in vivo in both mouse- and Galleria-passaged strains of C. neoformans. Phenotypic analysis in hva1Δ and hva1Δ+HVA1 strains revealed no significant differences in established virulence factors. Mice infected intravenously with the hva1Δ strain had higher fungal burden in the spleen and brain, but lower fungal burden in the lungs, and died faster than mice infected with H99W or the hva1Δ+HVA1 strain. Metabolomics analysis demonstrated a general increase in all amino acids measured in the disrupted strain and a block in the TCA cycle at isocitrate dehydrogenase, possibly due to alterations in the nicotinamide cofactor pool. Macrophage fungal burden experiments recapitulated the mouse hypervirulent phenotype of the hva1Δ strain only in the presence of exogenous NADPH. The crystal structure of the Hva1 protein was solved, and a comparison of structurally similar proteins correlated with the metabolomics data and potential interactions with NADPH. We report a new gene that modulates virulence through a mechanism associated with changes in fungal metabolism. PMID:27583447

  11. Fungal environment in different rabbit intensive farms

    Directory of Open Access Journals (Sweden)

    M. Verga

    2010-04-01

    Full Text Available Many environmental factors (for example, temperature, relative humidity, ventilation, NH3 concentration can influence the health and welfare of rabbits reared in intensive farms. Among these elements, microorganisms and, in particular, fungi play a pivotal role in the spreading of potential pathogenic and zoonotic diseases. Aim of our work was to evaluate the fungal contamination in two different rabbit rearing (A and B. SAS System® (PBI International, Italy and opened plates, filled with cultural media for fungal growth (environmental and dermatophytes have been used. The data collected in both the farms showed that, for environmental fungi, Aspergillus, Alternaria and Penicillium were the most spread. On the contrary, for dermatophytes, there was a difference between farm A and B. In fact, in the first one Microsporum canis (a known zoonotic agent has been recovered in high concentration, while in the second rearing we have isolated Microsporum gypseum a geophilic fungus with a very low pathogenic potential.

  12. When do arbuscular mycorrhizal fungi protect plant roots from pathogens?

    OpenAIRE

    Sikes, Benjamin A

    2010-01-01

    Arbuscular mycorrhizal (AM) fungi are mainly thought to facilitate phosphorus uptake in plants, but they can also perform several other functions that are equally beneficial. Our recent study sheds light on the factors determining one such function, enhanced plant protection from root pathogens. Root infection by the fungal pathogen Fusarium oxysporum was determined by both plant susceptibility and the ability of an AM fungal partner to suppress the pathogen. The non-susceptible plant species...

  13. 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.

  14. 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.

  15. Opportunistic yeast pathogens: reservoirs, virulence mechanisms, and therapeutic strategies.

    Science.gov (United States)

    Polvi, Elizabeth J; Li, Xinliu; O'Meara, Teresa R; Leach, Michelle D; Cowen, Leah E

    2015-06-01

    Life-threatening invasive fungal infections are becoming increasingly common, at least in part due to the prevalence of medical interventions resulting in immunosuppression. Opportunistic fungal pathogens of humans exploit hosts that are immunocompromised, whether by immunosuppression or genetic predisposition, with infections originating from either commensal or environmental sources. Fungal pathogens are armed with an arsenal of traits that promote pathogenesis, including the ability to survive host physiological conditions and to switch between different morphological states. Despite the profound impact of fungal pathogens on human health worldwide, diagnostic strategies remain crude and treatment options are limited, with resistance to antifungal drugs on the rise. This review will focus on the global burden of fungal infections, the reservoirs of these pathogens, the traits of opportunistic yeast that lead to pathogenesis, host genetic susceptibilities, and the challenges that must be overcome to combat antifungal drug resistance and improve clinical outcome. PMID:25700837

  16. Immunoglobulins in defense, pathogenesis, and therapy of fungal diseases.

    Science.gov (United States)

    Casadevall, Arturo; Pirofski, Liise-Anne

    2012-05-17

    Only two decades ago antibodies to fungi were thought to have little or no role in protection against fungal diseases. However, subsequent research has provided convincing evidence that certain antibodies can modify the course of fungal infection to the benefit or detriment of the host. Hybridoma technology was the breakthrough that enabled the characterization of antibodies to fungi, illuminating some of the requirements for antibody efficacy. As discussed in this review, fungal-specific antibodies mediate protection through direct actions on fungal cells and through classical mechanisms such as phagocytosis and complement activation. Although mechanisms of antibody-mediated protection are often species-specific, numerous fungal antigens can be targeted to generate vaccines and therapeutic immunoglobulins. Furthermore, the study of antibody function against medically important fungi has provided fresh immunological insights into the complexity of humoral immunity that are likely to apply to other pathogens.

  17. Interpretation of "fungal spikes" in Permian-Triassic boundary sections

    Science.gov (United States)

    Hochuli, Peter A.

    2016-09-01

    Abundant occurrences of the palynomorph Reduviasporonites have been described as "fungal spike" from several Permian/Triassic boundary sections and related to the supposed destruction of woody vegetation by fungal pathogens during the Permian/Triassic extinction event. The biological affinity of this taxa considered by some authors of fungal origin is still controversially discussed since there is geochemical evidence that it is most probably related to algae. The abundance peak of this species is used by some authors as a stratigraphic marker, notably in terrestrial Permian/Triassic boundary sections from South China. Illustrations of the reported fungal remains however show potentially erroneous taxonomic identification of Reduviasporonites, and, based on differences in thermal maturation, they may represent recent contamination. Here Reduviasporonites chalastus of Early Triassic age is illustrated together with recent fungal remains originating from a strongly weathered and otherwise barren sample from a Middle Triassic section.

  18. Anaerobic fungal populations

    International Nuclear Information System (INIS)

    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