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Sample records for deuteromycota hyphomycetes conidia

  1. Digitomyces, a new genus of hyphomycetes with cheiroid conidia.

    PubMed

    Mercado Sierra, Angel; Calduch, Misericordia; Gené, Josepa; Guarro, Josep; Delgado, Gregorio

    2003-01-01

    The new anamorphic genus Digitomyces, based on Dictyosporium verrucosum, is proposed. It is characterized by micronematous or semimacronematous conidiophores, integrated or discrete, holoblastic, determinate conidiogenous cells, and olivaceous to pale brown, verrucose, cheiroid conidia, with a truncate basal cell and (2-)3 arms. The new taxon is compared with morphologically similar anamorph genera.

  2. Effects of whole-stream nutrient enrichment on the concentration and abundance of aquatic hyphomycete conidia in transport.

    PubMed

    Gulis, Vladislav; Suberkropp, Keller

    2004-01-01

    The concentrations and relative abundances of aquatic hyphomycete conidia in water were followed during a three-year study in two headwater streams at Coweeta Hydrologic Laboratory, North Carolina, using the membrane-filtration technique. After a one-year pretreatment period, one of the streams was enriched continuously with inorganic nutrients (N+P) for two years while the other stream served as the reference. This ecosystem-level nutrient manipulation resulted in concentrations of aquatic hyphomycete conidia in the water of the treated stream that were 4.5-6.9 times higher than the concentrations observed during the pretreatment period and in the reference stream. Nutrient enrichment led to an increase in the number of fungal species detected on each sampling date. Changes in dominance patterns and relative abundances of individual species also were detected after treatment. Nutrient addition stimulates the reproductive activity of aquatic hyphomycetes, their colonization success and fungal-mediated leaf-litter decomposition. Such changes in the activity of the fungal community might affect higher trophic levels in lotic ecosystems.

  3. Nuclear staining of Paracoccidioides brasiliensis conidia.

    PubMed

    McEwen, J G; Restrepo, B I; Salazar, M E; Restrepo, A

    1987-10-01

    More than 80% of the conidia produced by two different isolates of Paracoccidioides brasiliensis, were found to be uninucleate; however, when they were incubated at 37 degrees C and began to transform into yeast cells, they became bi- or multi-nucleated, so that when most of the conidia had already transformed into yeast cells (72-96 h), there were at least four or five nuclei per cell in approximately 80% of the conidia examined.

  4. Failure of ticks to transmit Scopulariopsis brevicaulis (Deuteromycota), a common filamentous fungal commensal of ticks.

    PubMed

    Yoder, Jay A; Benoit, Joshua B; Rellinger, Eric J; Telford, Sam R

    2005-05-01

    The capacity of ticks to transmit a fungus was examined by analyzing tick saliva, host tissue from feeding sites, and host blood for presence of Scopulariopsis brevicaulis (Sacc.) Bainier, an internal mycosymbiont of the American dog tick, Dermacentor variabilis (Say), and lone star tick, Amnblyomma americanum (L.). Although >85% of ticks were infected with S. brevicaulis, conidia presence was low (0-5% of samples) in microscopic observations and mycological culturing of saliva expressed from larvae, nymphs, and adults. Additionally, the recovery of S. brevicaulis from blood and tissue feeding sites from a rabbit where S. brevicaulis-positive adult ticks had attached and fed was not increased compared with control tissue where no feeding occurred, indicating that transmission does not occur by the blood-feeding route. Tick mouthparts were found to contain S. brevicaulis in addition to Penicillium glabrum (Wehmer) Westling, but these agents were sparse in isolations from the feeding sites, which makes it unlikely that ticks act frequently as a mechanical fungal vector.

  5. Proteomic profile of dormant Trichophyton Rubrum conidia

    PubMed Central

    Leng, Wenchuan; Liu, Tao; Li, Rui; Yang, Jian; Wei, Candong; Zhang, Wenliang; Jin, Qi

    2008-01-01

    Background Trichophyton rubrum is the most common dermatophyte causing fungal skin infections in humans. Asexual sporulation is an important means of propagation for T. rubrum, and conidia produced by this way are thought to be the primary cause of human infections. Despite their importance in pathogenesis, the conidia of T. rubrum remain understudied. We intend to intensively investigate the proteome of dormant T. rubrum conidia to characterize its molecular and cellular features and to enhance the development of novel therapeutic strategies. Results The proteome of T. rubrum conidia was analyzed by combining shotgun proteomics with sample prefractionation and multiple enzyme digestion. In total, 1026 proteins were identified. All identified proteins were compared to those in the NCBI non-redundant protein database, the eukaryotic orthologous groups database, and the gene ontology database to obtain functional annotation information. Functional classification revealed that the identified proteins covered nearly all major biological processes. Some proteins were spore specific and related to the survival and dispersal of T. rubrum conidia, and many proteins were important to conidial germination and response to environmental conditions. Conclusion Our results suggest that the proteome of T. rubrum conidia is considerably complex, and that the maintenance of conidial dormancy is an intricate and elaborate process. This data set provides the first global framework for the dormant T. rubrum conidia proteome and is a stepping stone on the way to further study of the molecular mechanisms of T. rubrum conidial germination and the maintenance of conidial dormancy. PMID:18578874

  6. Hyphomycetes on the Vochysiaceae from the Brazilian cerrado.

    PubMed

    Dornelo-Silva, Denise; Dianese, José C

    2003-01-01

    New hyphomycetes are described in association with leaves of native plants of the family Vochysiaceae, as part of studies of cerrado fungi. Six new species are described belonging to genera Alternaria (A. qualeae sp. nov.), Janetia (J. salvertiae sp. nov.), Passalora (P. qualeae sp. nov.) and Periconiella (P. longispora sp. nov., P. qualeae-grandiflorae sp. nov. and P. campo-grandensis sp. nov.). A key to the species of Periconiella on Qualea is provided.

  7. Ergosterol-to-Biomass Conversion Factors for Aquatic Hyphomycetes

    PubMed Central

    Gessner, Mark O.; Chauvet, Eric

    1993-01-01

    Fourteen strains of aquatic hyphomycete species that are common on decaying leaves in running waters were grown in liquid culture and analyzed for total ergosterol contents. Media included an aqueous extract from senescent alder leaves, a malt extract broth, and a glucose-mineral salt solution. Concentrations of ergosterol in fungal mycelium ranged from 2.3 to 11.5 mg/g of dry mass. The overall average was 5.5 mg/g. Differences among both species and growth media were highly significant but followed no systematic pattern. Stationary-phase mycelium had ergosterol contents 10 to 12% lower or higher than mycelium harvested during the growth phase, but these differences were only significant for one of four species examined. Availability of plant sterols in the growth medium had no clear effect on ergosterol concentrations in two species tested. To convert ergosterol contents determined in field samples to biomass values of aquatic hyphomycetes, a general multiplicative factor of 182 is proposed. More accurate estimates would be obtained with species-specific factors. Using these in combination with estimates of the proportion of the dominant species in a naturally established community on leaves resulted in biomass estimates that were typically 20% lower than those obtained with the general conversion factor. Improvements of estimates with species-specific factors may be limited, however, by intraspecific variability in fungal ergosterol content. PMID:16348874

  8. Penzigomyces catalonicus, a new species of hyphomycetes from Spain.

    PubMed

    Mercado-Sierra, Angel; Gené, Josepa; Calduch, Misericordia; Guarro, Josep

    2004-01-01

    Penzigomyces catalonicus sp. nov., collected on dead branches of an unknown tree species in Spain, is described and illustrated. This fungus is characterized by short, dark brown, percurrent conidiophores, usually doliiform conidiogenous cells and ellipsoidal or slightly obclavate, (2-)3-4(-6) euseptate, thin-walled conidia. The new taxon is compared with species from other morphologically similar genera, and a key to the known species of Penzigomyces is provided.

  9. Elevated aluminium concentration in acidified headwater streams lowers aquatic hyphomycete diversity and impairs leaf-litter breakdown.

    PubMed

    Baudoin, J M; Guérold, F; Felten, V; Chauvet, E; Wagner, P; Rousselle, P

    2008-08-01

    Aquatic hyphomycetes play an essential role in the decomposition of allochthonous organic matter which is a fundamental process driving the functioning of forested headwater streams. We studied the effect of anthropogenic acidification on aquatic hyphomycetes associated with decaying leaves of Fagus sylvatica in six forested headwater streams (pH range, 4.3-7.1). Non-metric multidimensional scaling revealed marked differences in aquatic hyphomycete assemblages between acidified and reference streams. We found strong relationships between aquatic hyphomycete richness and mean Al concentration (r = -0.998, p < 0.0001) and mean pH (r = 0.962, p < 0.002), meaning that fungal diversity was severely depleted in acidified streams. By contrast, mean fungal biomass was not related to acidity. Leaf breakdown rate was drastically reduced under acidic conditions raising the issue of whether the functioning of headwater ecosystems could be impaired by a loss of aquatic hyphomycete species.

  10. Aquatic Hyphomycete Species Are Screened by the Hyporheic Zone of Woodland Streams

    PubMed Central

    Chauvet, Eric; Mermillod-Blondin, Florian; Assemat, Fiona; Elger, Arnaud

    2014-01-01

    Aquatic hyphomycetes strongly contribute to organic matter dynamics in streams, but their abilities to colonize leaf litter buried in streambed sediments remain unexplored. Here, we conducted field and laboratory experiments (slow-filtration columns and stream-simulating microcosms) to test the following hypotheses: (i) that the hyporheic habitat acting as a physical sieve for spores filters out unsuccessful strategists from a potential species pool, (ii) that decreased pore size in sediments reduces species dispersal efficiency in the interstitial water, and (iii) that the physicochemical conditions prevailing in the hyporheic habitat will influence fungal community structure. Our field study showed that spore abundance and species diversity were consistently reduced in the interstitial water compared with surface water within three differing streams. Significant differences occurred among aquatic hyphomycetes, with dispersal efficiency of filiform-spore species being much higher than those with compact or branched/tetraradiate spores. This pattern was remarkably consistent with those found in laboratory experiments that tested the influence of sediment pore size on spore dispersal in microcosms. Furthermore, leaves inoculated in a stream and incubated in slow-filtration columns exhibited a fungal assemblage dominated by only two species, while five species were codominant on leaves from the stream-simulating microcosms. Results of this study highlight that the hyporheic zone exerts two types of selection pressure on the aquatic hyphomycete community, a physiological stress and a physical screening of the benthic spore pool, both leading to drastic changes in the structure of fungal community. PMID:24441154

  11. Development of Carrot Medium Suitable for Conidia Production of Venturia nashicola

    PubMed Central

    Choi, Eu Ddeum; Kim, Gyoung Hee; Lee, Young Sun; Jung, Jae Sung; Song, Jang Hoon; Koh, Young Jin

    2017-01-01

    The causal fungus of pear scab, Venturia nashicola, grows slowly and rarely produces conidia on artificial media in the laboratory, but it produced conidia on the Cheongah medium containing Cheongah powder. V. nashicola grew too slow to produce conidia until 15 days after cultivation but produced conidia with 4 × 104 conidia/plate 30 days after cultivation on the Cheongah medium containing 1% Cheongah powder. V. nashicola showed a peak production of conidia with 4.5 × 105 conidia/plate 60 days after cultivation on the carrot medium containing 2% carrot powder, one of the constituents of Cheongah powder. The carrot medium is considered to be the best medium to obtain conidia of V. nashicola in the laboratory until now. This is the first report on the development of a suitable medium for conidia production of V. nashicola, as far as we know. PMID:28167890

  12. Capillary electrophoresis of conidia from cultivated microscopic filamentous fungi.

    PubMed

    Horká, Marie; Růzicka, Filip; Kubesová, Anna; Holá, Veronika; Slais, Karel

    2009-05-15

    In immunocompromised people fungal agents are able to cause serious infections with high mortality rate. An early diagnosis can increase the chances of survival of the affected patients. Simultaneously, the fungi produce toxins and they are frequent cause of allergy. Currently, various methods are used for detection and identification of these pathogens. They use microscopic examination and growth characteristic of the fungi. New methods are based on the analysis of structural elements of the target microorganisms such as proteins, polysaccharides, glycoproteins, nucleic acids, etc. for the construction of antibodies, probes, and primers for detection. The above-mentioned methods are time-consuming and elaborate. Here hydrophobic conidia from the cultures of different strains of the filamentous fungi were focused and separated by capillary zone electrophoresis and capillary isoelectric focusing. The detection was optimized by dynamic modifying of conidia by the nonionogenic tenside on the basis of pyrenebutanoate. Down to 10 labeled conidia of the fungal strains were fluorometrically detected, and isoelectric points of conidia were determined. The observed isoelectric points were compared with those obtained from the separation of the cultured clinical samples, and they were found to be not host-specific.

  13. Kinetic studies on the aggregation of Aspergillus niger conidia.

    PubMed

    Grimm, L H; Kelly, S; Hengstler, J; Göbel, A; Krull, R; Hempel, D C

    2004-07-20

    Morphology has a crucial effect on productivity and the supply of substrate for cultures of filamentous fungi. However, cultivation parameters leading to the desired morphology are often chosen empirically as the mechanisms governing the processes involved are usually unknown. For coagulating microorganisms like Aspergillus niger the morphological development is considered to start with the aggregation of conidia right after inoculation. To elucidate the mechanism of this process, kinetic studies were carried out using an in-line particle size analyzer. Based on the data obtained from these experiments a model for conidial aggregation is proposed in this article. It consists of two separate aggregation steps. The first one takes place immediately after inoculation, but only leads to a small decrease of total particle concentration. Most suspended conidia aggregate after a second aggregation step triggered by germination and hyphal growth. Aggregation velocity of this second phase is linearly dependent on the particle growth rate.

  14. Heterogeneity in liquid shaken cultures of Aspergillus niger inoculated with melanised conidia or conidia of pigmentation mutants.

    PubMed

    van Veluw, G J; Teertstra, W R; de Bekker, C; Vinck, A; van Beek, N; Muller, W H; Arentshorst, M; van der Mei, H C; Ram, A F J; Dijksterhuis, J; Wösten, H A B

    2013-03-15

    Black pigmented conidia of Aspergillus niger give rise to micro-colonies when incubated in liquid shaken medium. These micro-colonies are heterogeneous with respect to gene expression and size. We here studied the biophysical properties of the conidia of a control strain and of strains in which the fwnA, olvA or brnA gene is inactivated. These strains form fawn-, olive-, and brown-coloured conidia, respectively. The ΔolvA strain produced larger conidia (3.8 μm) when compared to the other strains (3.2-3.3 μm). Moreover, the conidia of the ΔolvA strain were highly hydrophilic, whereas those of the other strains were hydrophobic. The zeta potential of the ΔolvA conidia in medium was also more negative when compared to the control strain. This was accompanied by the near absence of a rodlet layer of hydrophobins. Using the Complex Object Parametric Analyzer and Sorter it was shown that the ratio of individual hyphae and micro-colonies in liquid shaken cultures of the deletion strains was lower when compared to the control strain. The average size of the micro-colonies of the control strain was also smaller (628 μm) than that of the deletion strains (790-858 μm). The size distribution of the micro-colonies of the ΔfwnA strain was normally distributed, while that of the other strains could be explained by assuming a population of small and a population of large micro-colonies. In the last set of experiments it was shown that relative expression levels of gpdA, and AmyR and XlnR regulated genes correlate in individual hyphae at the periphery of micro-colonies. This indicates the existence of transcriptionally and translationally highly active and lowly active hyphae as was previously shown in macro-colonies. However, the existence of distinct populations of hyphae with high and low transcriptional and translational activity seems to be less robust when compared to macro-colonies grown on solid medium.

  15. Optimization of Solid-State Fermentation for Improved Conidia Production of Beauveria bassiana as a Mycoinsecticide

    PubMed Central

    Pham, Tuan Anh; Kim, Jeong Jun

    2010-01-01

    The production of conidia of entomopathogenic Beauveria bassiana by solid-state fermentation was studied for the development of a biocontrol agent against aphid Myzus persicae. The optimal conditions for conidia production on polished white rice were 40% moisture content, 25℃ culture temperature, 2-day-old seeding culture grown in 3% corn meal, 2% rice bran, 2% corn steep powder medium, initial conidia concentration of 107 conidia/g in the wet rice, 10% inoculum size, and use of a polyethylene bag as a container. The polyethylene bag containing inoculated rice was hand-shaken every 12 hr during fermentation. Using optimal conditions, the maximum conidia production obtained was 4.05 g conidia/100 g dry rice after 14 days of cultivation, a rate 2.83 times higher than conidia yield of pre-optimization. PMID:23956642

  16. Photodynamic inactivation of Penicillium chrysogenum conidia by cationic porphyrins.

    PubMed

    Gomes, Maria C; Woranovicz-Barreira, Sandra M; Faustino, Maria A F; Fernandes, Rosa; Neves, Maria G P M S; Tomé, Augusto C; Gomes, Newton C M; Almeida, Adelaide; Cavaleiro, José A S; Cunha, Angela; Tomé, João P C

    2011-11-01

    This work reports the photophysical and biological evaluation of five cationic porphyrins as photosensitizers (PS) for the photodynamic inactivation (PDI) of Penicillium chrysogenum conidia. Two different cationic porphyrin groups were synthesized from 5,10,15,20-tetrakis(4-pyridyl)porphyrin and 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin. The photostability and singlet oxygen generation studies showed that these molecules are photostable and efficient singlet oxygen generators. PDI experiments of P. chrysogenum conidia conducted with 50 μmol L(-1) of photosensitiser under white light at a fluence rate of 200 mW cm(-2) over 20 min showed that the most effective PS caused a 4.1 log reduction in the concentration of viable conidia. The present results show that porphyrins 1a and 1b are more efficient PSs than porphyrin 2a while porphyrins 1c and 2b show no inactivation of P. chrysogenum. It is also clear that the effectiveness of the molecule as PS for antifungal PDI is strongly related with the porphyrin substituent groups, and consequently their solubility in physiological media. The average amount of PS adsorbed per viable conidium was a determining factor in the photoinactivation efficiency and varied between the different studied PSs. Cationic PSs 1a and 1b might be promising anti-fungal PDI agents with potential applications in phytosanitation, biofilm control, bioremediation, and wastewater treatment.

  17. Melanin dependent survival of Apergillus fumigatus conidia in lung epithelial cells.

    PubMed

    Amin, Shayista; Thywissen, Andreas; Heinekamp, Thorsten; Saluz, Hans Peter; Brakhage, Axel A

    2014-07-01

    Aspergillus fumigatus is the most important air-borne pathogenic fungus of humans. Upon inhalation of conidia, the fungus makes close contact with lung epithelial cells, which only possess low phagocytic activity. These cells are in particular interesting to address the question whether there is some form of persistence of conidia of A. fumigatus in the human host. Therefore, by also using uracil-auxotrophic mutant strains, we were able to investigate the interaction of A549 lung epithelial cells and A. fumigatus conidia in detail for long periods. Interestingly, unlike professional phagocytes, our study showed that the presence of conidial dihydroxynaphthalene (DHN) melanin enhanced the uptake of A. fumigatus conidia by epithelial cells when compared with non-pigmented pksP mutant conidia. Furthermore, conidia of A. fumigatus were able to survive within epithelial cells. This was due to the presence of DHN melanin in the cell wall of conidia, because melanised wild-type conidia showed a higher survival rate inside epithelial cells and led to inhibition of acidification of phagolysosomes. Both effects were not observed for white (non-melanised) conidia of the pksP mutant strain. Moreover, in contrast to pksP mutant conidia, melanised wild-type conidia were able to inhibit the extrinsic apoptotic pathway in A549 lung epithelial cells even for longer periods. The anti-apoptotic effect was not restricted to conidia, because both conidia-derived melanin ghosts (cell-free DHN melanin) and a different type of melanin, dihydroxyphenylalanine (DOPA) melanin, acted anti-apoptotically. Taken together, these data indicate the possibility of melanin-dependent persistence of conidia in lung epithelial cells.

  18. Preparation of fungal conidia impacts their susceptibility to inactivation by ethanol vapours.

    PubMed

    Dao, Thien; Dantigny, Philippe

    2009-11-15

    A common protocol employed for the preparation of conidia employs flooding a fungal colony grown on semi-solid media under optimum conditions with an aqueous solution. In contrast, conidia produced in a natural environment are usually not hydrated when disseminated in air and can be produced under water stress. In order to simulate the latter conditions, cultures were grown at different water activities and conidia were dry-harvested on the lid by turning the dishes upside-down then gently tapping the bottom of the box. This study aimed at assessing the effect of the preparation of fungal conidia on their inactivation by ethanol vapours. Firstly ethanol vapours (either 0.30 or 0.45 kPa) were applied to conidia obtained from the standardised protocol and to dry-harvested conidia for some species of Penicillium. While all dry-harvested conidia remained viable after 24 h of treatment, about 1.0, 3.5 and 2.5 log(10) reductions were observed for hydrated conidia of Penicillium chrysogenum, Penicillium digitatum and Penicillium italicum respectively. Secondly ethanol vapours (0.67 kPa) were applied to dry-harvested conidia obtained from cultures grown at 0.99 a(w) and at reduced water activities. For all species, the susceptibility to ethanol vapours of conidia obtained at 0.99 a(w) was significantly greater than that of conidia obtained at reduced water activities. Conidia produced in a natural environment under non-optimal conditions would be much more resistant to ethanol vapours than those produced in the laboratory. This phenomenon may be due to a reduced intracellular water activity of dry-harvested conidia.

  19. Evaluation of soyscreen in an oil-based formulation for UV protection of Beauveria bassiana conidia.

    PubMed

    Behle, Robert W; Compton, David L; Laszlo, Joseph A; Shapiro-Ilan, David I

    2009-10-01

    Soyscreen oil was studied as a formulation ingredient to protect Beauveria bassiana (Balsamo) Vuillemin conidia from UV degradation. Feruloylated soy glycerides, referred to as Soyscreen oil, are biobased UV-absorbing molecules made by combining molecules of soybean oil with ferulic acid. Conidia stored in Soyscreen oil for 28 wk at 25, 30, and 35 degrees C retained viability as well as conidia stored in sunflower oil, demonstrating that Soyscreen did not adversely affect viability with prolonged storage. For samples applied to glass and exposed to simulated sunlight (xenon light), conidia in sunflower oil with or without sunscreens (Soyscreen or oxyl methoxycinnimate) had similar conidia viability after exposure. These oil formulations retained conidia viability better than conidia applied as an aqueous treatment. However, the 10% Soyscreen oil formulation applied to field grown cabbage (Brassica oleracea L.) and bean (Phaseolus vulgaris L.) plants, did not improve residual insecticidal activity compared with aqueous applications of unformulated conidia or two commercial formulations when assayed against Trichoplusia ni (Hübner) larvae. Our results suggest that the oil applications lose UV protection because the oil was absorbed by the leaf. This conclusion was supported in subsequent laboratory exposures of conidia in oil-based formulations with UV screens applied to cabbage leaves or balsa wood, which lost protection as measured by decreased viability of conidia when exposed to simulated sunlight. As a result, additional formulation techniques such as encapsulation to prevent separation of the protective oil from the conidia may be required to extend protection when oil formulations are applied in the field.

  20. Paleomycology of the Princeton Chert I. Fossil hyphomycetes associated with the early Eocene aquatic angiosperm, Eorhiza arnoldii.

    PubMed

    Klymiuk, Ashley A; Taylor, Thomas N; Taylor, Edith L; Krings, Michael

    2013-01-01

    The Eocene (~ 48.7 Ma, Ypresian-Lutetian) Princeton Chert of British Columbia, Canada, has long been recognized as a significant paleobotanical locality, and a diverse assemblage of anatomically preserved fossil plants has been extensively documented. Co-occurring fossil fungi also have been observed, but the full scope of their diversity has yet to be comprehensively assessed. Here, we present the first of a series of investigations of fossilized fungi associated with the silicified plants of the Princeton Chert. This report focuses on saprotrophic, facultative-aquatic hyphomycetes observed in cortical aerenchyma tissue of an enigmatic angiosperm, Eorhiza arnoldii. Our use of paleontological thin sections provides the opportunity to observe and infer developmental features, making it possible to more accurately attribute two hyphomycetes that were observed in previous studies. These comprise multiseptate, holothallic, chlamydospore-like phragmoconidia most similar to extant Xylomyces giganteus and basipetal phragmospore-like chains of amerospores like those of extant Thielaviopsis basicola. We also describe a third hyphomycete that previously has not been recognized from this locality; biseptate, chlamydosporic phragmoconidia are distinguished by darkly melanized, inflated apical cells and are morphologically similar to Brachysporiella rhizoidea or Culcitalna achraspora.

  1. Fate of conidia of Paracoccidioides brasiliensis after ingestion by resident macrophages or cytokine-treated macrophages.

    PubMed Central

    Cano, L E; Brummer, E; Stevens, D A; Restrepo, A

    1992-01-01

    Conidia ingested by resident macrophages had an enhanced percentage of transformation to yeast cells compared with those in culture medium without macrophages. The yeast cells subsequently grew intracellularly by budding. Macrophages treated with cytokines from antigen-stimulated spleen cells from immunized mice significantly inhibited transformation of ingested conidia. PMID:1563800

  2. Fate of conidia of Paracoccidioides brasiliensis after ingestion by resident macrophages or cytokine-treated macrophages.

    PubMed

    Cano, L E; Brummer, E; Stevens, D A; Restrepo, A

    1992-05-01

    Conidia ingested by resident macrophages had an enhanced percentage of transformation to yeast cells compared with those in culture medium without macrophages. The yeast cells subsequently grew intracellularly by budding. Macrophages treated with cytokines from antigen-stimulated spleen cells from immunized mice significantly inhibited transformation of ingested conidia.

  3. Novel technique for quantifying adhesion of Metarhizium anisopliae conidia to the tick cuticle.

    PubMed

    Ment, Dana; Gindin, Galina; Rot, Asael; Soroker, Victoria; Glazer, Itamar; Barel, Shimon; Samish, Michael

    2010-06-01

    The present study describes an accurate quantitative method for quantifying the adherence of conidia to the arthropod cuticle and the dynamics of conidial germination on the host. The method was developed using conidia of Metarhizium anisopliae var. anisopliae (Metschn.) Sorokin (Hypocreales: Clavicipitaceae) and engorged Rhipicephalus annulatus (Say) (Arachnida: Ixodidae) females and was also verified for M. anisopliae var. acridum Driver et Milner (Hypocreales: Clavicipitaceae) and Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) larvae. This novel method is based on using an organic solvent (dichloromethane [DCM]) to remove the adhered conidia from the tick cuticle, suspending the conidia in a detergent solution, and then counting them using a hemocytometer. To confirm the efficacy of the method, scanning electron microscopy (SEM) was used to observe the conidial adherence to and removal from the tick cuticle. As the concentration of conidia in the suspension increased, there were correlating increases in both the number of conidia adhering to engorged female R. annulatus and tick mortality. However, no correlation was observed between a tick's susceptibility to fungal infection and the amount of adhered conidia. These findings support the commonly accepted understanding of the nature of the adhesion process. The mechanism enabling the removal of the adhered conidia from the host cuticle is discussed.

  4. Microencapsuling aerial conidia of Trichoderma harzianum through spray drying at elevated temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trichoderma conidia are mostly produced by solid fermentation systems. Inoculum is produced by liquid culturing, and then transferred to solid substrate for aerial conidial production. Aerial conidia of T. harzianum are hydrophilic in nature, and it is difficult to separate them from the solid subst...

  5. Cell wall alpha1-3glucans induce the aggregation of germinating conidia of Aspergillus fumigatus.

    PubMed

    Fontaine, Thierry; Beauvais, Anne; Loussert, Céline; Thevenard, Benoît; Fulgsang, Claus C; Ohno, Naohito; Clavaud, Cécile; Prevost, Marie-Christine; Latgé, Jean-Paul

    2010-08-01

    The germination of Aspergillus fumigatus conidia can be divided into four stages: breaking of dormancy, isotropic swelling, establishment of cell polarity, and formation of a germ tube. Swelling of conidia is associated in liquid medium with a multi-cellular aggregation that produced large clumps of conidia. Conidial aggregation can be specifically prevented by the addition of alpha1-3glucanase. Swollen conidia specifically adhere to insoluble alpha1-3glucan chains. Electron microscopy studies showed that cell wall alpha1-3glucan chains became exposed at the cell surface during the swelling. These results demonstrate that cell wall alpha1-3glucans play an essential role in the aggregation between swollen conidia. Experiments with alpha1-3glucan coated latex beads show that alpha1-3glucan chains interacted between them without the requirement of any other cell wall component suggesting that biophysical properties of alpha1-3glucans are solely responsible for conidial aggregation.

  6. Killing of Paracoccidioides brasiliensis conidia by pulmonary macrophages and the effect of cytokines.

    PubMed

    Cano, L E; Arango, R; Salazar, M E; Brummer, E; Stevens, D A; Restrepo, A

    1992-01-01

    The ability of conidia, the infectious form of the dimorphic fungus Paracoccidioides brasiliensis, to be killed in vitro by murine pulmonary macrophages was studied. Mice were immunized by intravenous injection of killed conidia, which resulted in cellular immunity demonstrated by delayed type hypersensitivity in vivo and macrophage migration inhibition factor production in vitro. Resident pulmonary macrophages from non-immune mice were able to significantly kill the conidia (28%). Such macrophages treated with supernatants (cytokines) from antigen-stimulated immune mononuclears had a markedly enhanced ability to kill conidia (73%). These results show that activated pulmonary macrophages are potent killers of conidia of P. brasiliensis and that immune mononuclears play a role in activation of macrophages. Activated macrophages may be important for pulmonary defense against the initial stages of infection with this fungus.

  7. Physiological Response of Neurospora Conidia to Freezing in the Dehydrated, Hydrated, or Germinated State

    PubMed Central

    Leef, James L.; Mazur, Peter

    1978-01-01

    This study concerned the response to freezing of Neurospora crassa conidia in four different states: air-dry, hydrated in water, hydrated in Vogel medium lacking only sucrose, or hydrated in complete Vogel medium. All hydrated conidia were incubated in one of the above media for various times before freezing and were then washed and frozen in distilled water. Viability was estimated by three techniques, and the agreement among them was good. Hydration of air-dry conidia was found to be very rapid and, once hydrated, the conidia were much more sensitive to rapid freezing than they were before hydration. Rapidly cooled conidia survived freezing to a much higher extent when the warming rate was rapid than when it was slow; slowly cooled conidia showed little or no dependence on the warming rate. This sensitivity to rapid cooling and slow warming was attributed to the effects of intracellular ice. The sensitivity to freezing could be reversed by dehydrating the conidia in vacuo before freezing; thus, it was concluded that the presence or absence of water is the determining factor in the initial sensitivity due to freezing. In water, the sensitivity remained constant from 2 min to 15 days after hydration. Although conidia hydrated in growth medium lacking sucrose remained metabolically inactive, their sensitivity to rapid freezing decreased as a function of time in the medium before freezing. The reason for this decreased sensitivity is not understood. Conidia hydrated in complete growth medium (i.e., containing sucrose) became metabolically active and, after the initial sensitivity associated with hydration, became increasingly more sensitive to freezing as a function of their time in the medium. Drying itself was deleterious to metabolically active conidia, and those that survived dehydration did not exhibit a large absolute increase in resistance to subsequent freezing. The increase in sensitivity to freezing and to drying seems associated with the presence of

  8. Response of Aquatic Hyphomycete Communities to Changes in Heavy Metal Exposure

    NASA Astrophysics Data System (ADS)

    Sridhar, K. R.; Bärlocher, Felix; Krauss, Gerd-Joachim; Krauss, Gudrun

    2005-02-01

    Decomposition of Alnus glutinosa (alder) leaves was studied in a severely (site H4) and a moderately (site H8) heavy metal polluted stream in the former copper shale mining district of Mansfeld, Central Germany. Leaves at H8 had reduced fungal diversity and spore production but a high exponential decay rate (k = 0.065). No further mass loss of leaves occurred at H4 after 4-6 weeks, and fungal diversity and spore production were lower than in H8. Decay and sporulation rates gradually increased to values of H8 control leaves in leaves preincubated in H4 and then transferred to H8. These increases correlated with the invasion of transplanted leaves by Tetracladium marchalianum and Tricladium angulatum. In the reverse transplant experiment (H8 to H4), mass loss appeared to stop immediately. Sporulation rates also declined, but remained consistently above levels in H4 control leaves. Leaves precolonized in the laboratory by one of three aquatic hyphomycete species exhibited increased decay rates in both streams. Sporulation rates on these leaves were greater than those of control leaves in H4, but smaller than those of control leaves in H8.

  9. Early events in macrophage killing of Aspergillus fumigatus conidia: new flow cytometric viability assay.

    PubMed

    Marr, K A; Koudadoust, M; Black, M; Balajee, S A

    2001-11-01

    Detailed investigations of macrophage phagocytosis and killing of Aspergillus fumigatus conidia have been limited by technical difficulties in quantifying fungal uptake and viability. In order to study early events in cell pathogen ingestion and killing, we developed a new flow cytometry assay that utilizes the fungus-specific viability dye FUN-1. Metabolically active A. fumigatus conidia accumulate orange fluorescence in vacuoles, while dormant or dead conidia stain green. After incubation within THP-1 cells, recovered conidia are costained with propidium iodide (PI) to discriminate between dormant and dead cells. Flow cytometric measurements of FUN-1 metabolism and PI uptake provide indicators of conidial viability, dormancy, and death. Conidial phagocytosis and killing are also assessed by measurement of green and orange FUN-1 fluorescence within the THP-1 cell population. Compared to previously described methods, this assay has less error introduced by membrane permeability changes and serial dilution of filamentous fungal forms. Results suggest that the THP-1 cells kill conidia rapidly (within 6 h) after exposure. Conidia that are preexposed to human serum are ingested and killed more quickly than are nonopsonized conidia.

  10. Transformation of Epichloë typhina by electroporation of conidia

    PubMed Central

    2011-01-01

    Background Choke, caused by the endophytic fungus Epichloë typhina, is an important disease affecting orchardgrass (Dactylis glomerata L.) seed production in the Willamette Valley. Little is known concerning the conditions necessary for successful infection of orchardgrass by E. typhina. Detection of E. typhina in plants early in the disease cycle can be difficult due to the sparse distribution of hyphae in the plant. Therefore, a sensitive method to detect fungal infection in plants would provide an invaluable tool for elucidating the conditions for establishment of infection in orchardgrass. Utilization of a marker gene, such as the green fluorescent protein (GFP), transformed into Epichloë will facilitate characterization of the initial stages of infection and establishment of the fungus in plants. Findings We have developed a rapid, efficient, and reproducible transformation method using electroporation of germinating Epichloë conidia isolated from infected plants. Conclusions The GFP labelled E. typhina provides a valuable molecular tool to researchers studying conditions and mechanisms involved in the establishment of choke disease in orchardgrass. PMID:21375770

  11. Ovularia puerariae Sawada is the hyphomycetous anamorph of a new Marasmius species on living leaves of kudzu (Pueraria montana, Fabaceae).

    PubMed

    Kirschner, Roland; Lee, I-Shu; Chen, Chee-Jen

    2013-01-01

    An arthroconidial hyphomycete on living leaves of kudzu (Pueraria montana, Fabaceae), originally described by Sawada in 1959 as Ovularia puerariae, was rediscovered. This anamorph is connected to an unknown Marasmius teleomorph belonging to section Globulares, which develops on the same living leaves. Ultrastructure and LSU rDNA sequence analysis of the anamorph confirm this connection. The fungus does not have only a unique biology among agarics, comparable only to Mycena citricolor, but also has the potential for application as a control agent of kudzu. During comparison with similar anamorph genera, Illosporium graminicola was found to be a synonym for Beniowskia sphaeroidea.

  12. Germination of fungal conidia after exposure to low concentration ozone atmospheres.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The germinability of conidia of Alternaria alternata, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, or Penicillium italicum was determined periodically during exposure for approximately 100 days to a humid atmosphere of air alone or air containing 150 ppb ozone ...

  13. THE POWER OF THE SMALL: THE EXAMPLE OF Paracoccidioides brasiliensis CONIDIA

    PubMed Central

    RESTREPO, Angela; CANO, Luz Elena; GONZALEZ, Ángel

    2015-01-01

    SUMMARY Research on Paracoccidioides brasiliensis has centered in the yeast cell probably because of the lack of distinctive features in the mycelium. In 1942 and for the first time, lateral conidia were noticed in the fungus' hyphae. Later on, Brazilian, Venezuelan and Argentinean researchers described "aleurias" when the fungus was grown in natural substrates. In 1970 authors became interested in the conidia and were able to obtain them in large numbers and treat them as individual units. Their shape and size were defined and the presence of all the elements of a competent eukaryotic cell were demonstrated. Conidia exhibited thermal dimorphism and, additionally, when given intranasally to BALB/c male mice, they converted into yeasts in the lungs and produce progressive pulmonary lesions with further dissemination to other organs. Studies on the phagocyte-conidia interaction were revealing and showed that these versatile structures allow a better understanding of the host- P. brasiliensis interactions. PMID:26465363

  14. Comparison of methodologies for conidia production by Alternaria alternata from citrus

    PubMed Central

    Carvalho, Daniel D. C.; Alves, Eduardo; Batista, Tereza R. S.; Camargos, Renato B.; Lopes, Eloísa A. G. L.

    2008-01-01

    Conidia production is a problem in the study of Alternaria alternata from citrus. Thus, this study aimed to compare existing methodologies for conidial production of A. alternata isolated from Ponkan tangerine (2 isolates), Cravo lemon (1 isolate), Pêra orange (2 isolates) and Murcott tangor (1 isolate). The methodologies used were conidia production with 12 and 24 hours under white fluorescent light, evaluation with 24 and 48 hours after applying fungal mycelium stress technique, cold stress followed by injury of mycelium and evaluation with 24 hours, using healthy vegetable tissue and the use of black fluorescent near ultraviolet (NUV) lamp. Satisfactory result was obtained with A. alternata isolate from Murcott tangor, with the production of 2.8 × 105 conidia mL-1, when fungal mycelium was stressed (Petri dish with 66.66% of fungi growth) and subsequently 24 h of growth. The use of white light (24 h) and black fluorescent NUV lamp also induced expressive conidia production by one isolate of Ponkan tangerine, which produced 17.2 × 105 and 10.1 × 105conidia mL-1 and another of Murcott tangor, which produced 13.9 × 105 and 10.1 × 105 conidia mL-1, respectively. The remaining methodologies analyzed in this study were not able to induce conidia production in satisfactory quantity. The use of both mycelium stress technique and white light (24 h) and black fluorescent NUV lamp allowed the production of enough quantities of conidia to be used in vitro (detection of fungitoxic substances) and in vivo (pathogenicity test) assays, respectively. PMID:24031309

  15. Interaction between Paracoccidioides brasiliensis conidia and the coagulation system: involvement of fibrinogen.

    PubMed

    Tamayo, Diana; Hernández, Orville; Muñoz-Cadavid, Cesar; Cano, Luz Elena; González, Angel

    2013-06-01

    The infectious process starts with an initial contact between pathogen and host. We have previously demonstrated that Paracoccidioides brasiliensis conidia interact with plasma proteins including fibrinogen, which is considered the major component of the coagulation system. In this study, we evaluated the in vitro capacity of P. brasiliensis conidia to aggregate with plasma proteins and compounds involved in the coagulation system. We assessed the aggregation of P. brasiliensis conidia after incubation with human serum or plasma in the presence or absence of anticoagulants, extracellular matrix (ECM) proteins, metabolic and protein inhibitors, monosaccharides and other compounds. Additionally, prothrombin and partial thromboplastin times were determined after the interaction of P. brasiliensis conidia with human plasma. ECM proteins, monosaccharides and human plasma significantly induced P. brasiliensis conidial aggregation; however, anticoagulants and metabolic and protein inhibitors diminished the aggregation process. The extrinsic coagulation pathway was not affected by the interaction between P. brasiliensis conidia and plasma proteins, while the intrinsic pathway was markedly altered. These results indicate that P. brasiliensis conidia interact with proteins involved in the coagulation system. This interaction may play an important role in the initial inflammatory response, as well as fungal disease progression caused by P. brasiliensis dissemination.

  16. Melanin is required for the formation of the multi-cellular conidia in the endophytic fungus Pestalotiopsis microspora.

    PubMed

    Yu, Xi; Huo, Liang; Liu, Heng; Chen, Longfei; Wang, Yu; Zhu, Xudong

    2015-10-01

    Melanin plays an important role in regulating various biological processes in many fungi. However, its biological role in conidiation remains largely elusive. We report here that conidia production, morphogenesis, integrity, germination and their viability in Pestalotiopsis microspora require the polyketide-derived melanin. A polyketide synthase gene, pks1, was identified and demonstrated responsible for melanin biosynthesis in this fungus. A targeted deletion mutant strain Δpks1 displayed a defect in pigmentation of conidia and had an albino colonial phenotype. Interestingly, Δpks1 produced approximately 6-fold as many conidia as the wild type did, suggesting a negative modulation of melanin on conidia production in this fungus. Moreover, the conidia failed to develop into the normal five-cell morphology, rather the three main-body cells separated via constriction at the original septum position to generate three independent mutant conidia. This result suggests a novel role of melanin in the formation of the multi-cellular conidia. Germ tubes could develop from the three different types of mutant conidia and kept elongating, despite a significantly lower germination rate was observed for them. Still more, the unpigmented conidia became permeable to Calcofluor White and DAPI, suggesting the integrity of the conidia was impaired. Deliberate inhibition of melanin biosynthesis by a specific inhibitor, tricyclazole, led to a similar phenotypes. This work demonstrates a new function of fungal melanin in conidial development.

  17. Solid substrate production of Epicoccum nigrum conidia for biological control of brown rot on stone fruits.

    PubMed

    Larena, I; De Cal, A; Melgarejo, P

    2004-07-15

    Production of conidia of Epicoccum nigrum, a biocontrol agent of the fungal pathogen Monilinia laxa, was tested in liquid- and solid-state fermentation. Liquid fermentation was conducted in 250 ml Erlenmeyer flasks containing 50 ml of a mineral medium (containing per litre: 20 g lactose, 10 g NO3K, 1 g K2HPO4, 0.5 g MgSO4.7H2O, and 1 ml of a minor-element solution), inoculated with 2 x 10(5) E. nigrum conidia ml(-1), and incubated at 20-25 degrees C and 150 rpm for 7 days. Solid-state fermentation was carried out in specially designed plastic bags (600 cm3) (VALMIC) containing either 50 g of peat/vermiculite (1:1, w/w), or 50 g of peat/vermiculite/lentil meal (1:1:1, w/w/w) with 40% (v/w) initial moisture content. Substrate was inoculated with a conidial suspension of E. nigrum to give 10(5) conidia g(-1) substrate, and bags were incubated at 20-25 degrees C for 7 days in darkness. The amount of conidia of E. nigrum obtained in solid-state fermentation with substrate based on peat/vermiculite/lentil meal was 10-fold higher than with substrate based on peat/vermiculite or in liquid fermentation. Conidial production under these conditions was maintained in the range of 10(8) conidia g(-1) substrate from 10 to 150 days after inoculation. Germinability of these conidia was >90%. Addition of other nutrients than lentil meal to peat/vermiculite did not enhance production of conidia. Presence of peat in the substrate was necessary for good conidia production, but change in the kind of peat or vermiculite did not improve conidial production. Conidial production was similar when the substrate was inoculated with 10(5), 10(6) or 10(7) conidia g(-1) dry substrate. Incubation of bags in light conditions did not enhance conidial production. Fresh conidia produced in this solid-state fermentation system reduced the incidence and lesion diameter induced by M. laxa on peaches.

  18. Effects of Stachybotrys chartarum (atra) conidia and isolated toxin on lung surfactant production and homeostasis.

    PubMed

    Mason, C D; Rand, T G; Oulton, M; MacDonald, J M; Scott, J E

    1998-01-01

    This study evaluated the effects of Stachybotrys chartarum conidia and a trichothecene, isosatratoxin-F, on choline incorporation into DSPC by fetal rabbit alveolar type II cells and on alveolar surfactant subtypes in mice. Exposure of fetal rabbit type II cells to S. chartarum conidia at concentrations of 10(3) to 10(6) conidia ml(-1) significantly depressed [3H] choline incorporation after 24 h of exposure. Exposure of the rabbit cells to 10(5) to 10(6) conidia ml(-1) also resulted in significantly depressed [3H] choline uptake after 48 h. Additionally, fetal rabbit alveolar type II cells exposed to isosatratoxin-F in concentrations ranging from 10(-9) to 10(-4) M showed a significant reduction in [3H] choline incorporation into DSPC. Alveolar surfactant phospholipid concentrations in the different metabolic subfractions of lung lavage fluid of mice intratracheally exposed to either 50 microl of 10(7) ml(-1) S. chartarum conidia or 50 microl 10(-7) M isosatratoxin-F showed some significant changes at 12, 24, 48, and 72 h post-exposure, compared to the surfactant subfractions of control mice which were either untreated, exposed to saline or to 50 microl of 10(-7) ml(-1) Cladosporium cladosporioides conidia. In both the S. chartarum- and the isosatratoxin-F-treated mice, exposure significantly increased P10, P100, and S100 phospholipid concentrations, while the P60 phospholipid concentrations were depressed. In contrast, C. cladosporioides-treated mice showed only one significant change in subfraction phospholipid concentration: P60 was depressed at 48 h post-exposure. These results reveal that alveolar type II cells are sensitive to exposure to S. chartarum conidia and to isosatratoxin F. Sensitivity is manifest by alterations in the normal metabolic processing of alveolar surfactant. In exposed mice, this effect appears to involve a significant increase in newly secreted surfactant and an accumulation of the used surfactant forms.

  19. Production of Conidia by the Fungus Metarhizium anisopliae Using Solid-State Fermentation.

    PubMed

    Loera-Corral, Octavio; Porcayo-Loza, Javier; Montesinos-Matias, Roberto; Favela-Torres, Ernesto

    2016-01-01

    This chapter describes the production of conidia by Metarhizium anisopliae using solid-state fermentation. Before production of conidia, procedures for strains conservation, reactivation, and propagation are essential in order to provide genetic stability of the strains. The strain is conserved in freeze-dried vials and then reactivated through insect inoculation. Rice is used as a substrate for the conidia production in two different bioreactors: plastic bags and tubular bioreactor. The CO2 production in the tubular bioreactors is measured with a respirometer; this system allows calculating indirect growth parameters as lag time (tlag) (25-35 h), maximum rate of CO2 production (rCO2 max) (0.5-0.7 mg/gdm h), specific rate of CO2 production (μ) (0.10-0.15 1/h), and final CO2 production (CO2) (100-120 mg/gdm). Conidial yield per gram of dry substrate (gdm) should be above 1 × 10(9) conidia/gdm after 10 days of incubation. Germination and viability of conidia obtained after 10 days of incubation should be above 80 % and 75 %, respectively. Bioassays using of Tenebrio molitor as a host insect should yield a final mortality above 80 %.

  20. Interaction of Aspergillus fumigatus conidia with Acanthamoeba castellanii parallels macrophage-fungus interactions.

    PubMed

    Van Waeyenberghe, Lieven; Baré, Julie; Pasmans, Frank; Claeys, Myriam; Bert, Wim; Haesebrouck, Freddy; Houf, Kurt; Martel, An

    2013-12-01

    Aspergillus fumigatus and free-living amoebae are common inhabitants of soil. Mechanisms of A. fumigatus to circumvent the amoeba's digestion may facilitate overcoming the vertebrate macrophage defence mechanisms. We performed co-culture experiments using A. fumigatus conidia and the amoeba Acanthamoeba castellanii. Approximately 25% of the amoebae ingested A. fumigatus conidia after 1 h of contact. During intra-amoebal passage, part of the ingested conidia was able to escape the food vacuole and to germinate inside the cytoplasm of A. castellanii. Fungal release into the extra-protozoan environment by exocytosis of conidia or by germination was observed with light and transmission electron microscopy. These processes resulted in structural changes in A. castellanii, leading to amoebal permeabilization without cell lysis. In conclusion, A. castellanii internalizes A. fumigatus conidia, resulting in fungal intracellular germination and subsequent amoebal death. As such, this interaction highly resembles that of A. fumigatus with mammalian and avian macrophages. This suggests that A. fumigatus virulence mechanisms to evade macrophage killing may be acquired by co-evolutionary interactions among A. fumigatus and environmental amoebae.

  1. Molecular and physiological effects of environmental UV radiation on fungal conidia.

    PubMed

    Braga, Gilberto U L; Rangel, Drauzio E N; Fernandes, Éverton K K; Flint, Stephan D; Roberts, Donald W

    2015-08-01

    Conidia are specialized structures produced at the end of the asexual life cycle of most filamentous fungi. They are responsible for fungal dispersal and environmental persistence. In pathogenic species, they are also involved in host recognition and infection. Conidial production, survival, dispersal, germination, pathogenicity and virulence can be strongly influenced by exposure to solar radiation, although its effects are diverse and often species dependent. UV radiation is the most harmful and mutagenic waveband of the solar spectrum. Direct exposure to solar radiation for a few hours can kill conidia of most fungal species. Conidia are killed both by solar UV-A and UV-B radiation. In addition to killing conidia, which limits the size of the fungal population and its dispersion, exposures to sublethal doses of UV radiation can reduce conidial germination speed and virulence. The focus of this review is to provide an overview of the effects of solar radiation on conidia and on the major systems involved in protection from and repair of damage induced by solar UV radiation. The efforts that have been made to obtain strains of fungi of interest such as entomopathogens more tolerant to solar radiation will also be reviewed.

  2. Production of conidia by entomopathogenic fungi: from inoculants to final quality tests.

    PubMed

    Muñiz-Paredes, Facundo; Miranda-Hernández, Francisco; Loera, Octavio

    2017-03-01

    Demand for biopesticides is growing due to the increase of areas under integrated pest management worldwide. Conidia from entomopathogenic fungi play a major role as infective units in the current market of biopesticides. Success in a massive production of fungal conidia include the use of proper long-term conservation microbial methods, aimed at preserving the phenotypic traits of the strains. The development of suitable inoculants should also be considered since that favours a rapid germination and invasiveness of the substrate in solid state cultures (SSC). After the selection of a suitable fungal strain, proven optimization approaches for SSC mainly include the combination of substrates, moisture, texturizers, aeration and moderate stress to induce conidiation. Nonetheless, during storage and upon application in open fields, conidia either as free propagules or imbibed in formulations are subjected to stress due to abiotic factors, then quality should be preserved to resist such harsh conditions. All of these topics are analysed in this report.

  3. Filter Paper Degrading Ability of a Trichoderma Strain With Multinucleate Conidia

    NASA Astrophysics Data System (ADS)

    Toyama, Hideo; Yano, Makiko; Hotta, Takeshi; Toyama, Nobuo

    The multinucleate conidia were produced from the green mature conidia of Trichoderma reesei Rut C-30 strain by colchicine treatment. The strain with higher Filter paper degrading ability was selected among those conidia using a double layer selection medium. The selected strain, JS-2 was able to collapse the filter paper within 15 min but the original strain took 25 min to collapse it completely. Moreover, the amount of reducing sugar in the L-type glass tube of the strain, JS-2, was greater than that of the original strain. The Avicel, CMC-Na, and Salicin hydrolyzing activity of the strain, JS-2, increased 2.1 times, 1.2 times, and 3.6 times higher than that of the original strain.

  4. Early neutrophil recruitment and aggregation in the murine lung inhibit germination of Aspergillus fumigatus Conidia.

    PubMed

    Bonnett, Colin R; Cornish, E Jean; Harmsen, Allen G; Burritt, James B

    2006-12-01

    Several types of polymorphonuclear neutrophil (PMN) deficiency are a predisposing condition for fatal Aspergillus fumigatus infection. In order to study the defensive role of PMNs in the lungs, with particular reference to PMN recruitment and antimicrobial oxidant activity, responses to pulmonary instillation of A. fumigatus conidia were examined. Responses in BALB/c and C57BL/6 mice were compared with those in CXCR2(-/-) and gp91(phox-/-) mice, which are known to have delayed recruitment of PMN to the lungs in response to inflammatory stimuli and inactive NADPH oxidase, respectively. In BALB/c mice, PMNs were recruited to the lungs and formed oxidase-active aggregates with conidia, which inhibited germination. In C57BL/6, gp91(phox-/-), and CXCR2(-/-) mice, PMN recruitment was slower and there was increased germination compared to that in BALB/c mice at 6 and 12 h. In gp91(phox-/-) mice, germination was extensive in PMN aggregates but negligible in alveolar macrophages (AM). Lung sections taken at 6 and 48 h from BALB/c mice showed PMN accumulation at peribronchiolar sites but no germinating conidia. Those from C57BL/6 and CXCR2(-/-) mice showed germinating conidia at 6 h but not at 48 h and few inflammatory cells. In contrast, those from gp91(phox-/-) mice showed germination at 6 h with more-extensive hyphal proliferation and tissue invasion at 48 h. These results indicate that when the lungs are exposed to large numbers of conidia, in addition to the phagocytic activity of AM, early PMN recruitment and formation of oxidative-active aggregates are essential in preventing germination of A. fumigatus conidia.

  5. A Murine Inhalation Model to Characterize Pulmonary Exposure to Dry Aspergillus fumigatus Conidia

    PubMed Central

    Buskirk, Amanda D.; Green, Brett J.; Lemons, Angela R.; Nayak, Ajay P.; Goldsmith, W. Travis; Kashon, Michael L.; Anderson, Stacey E.; Hettick, Justin M.; Templeton, Steven P.; Germolec, Dori R.; Beezhold, Donald H.

    2014-01-01

    Most murine models of fungal exposure are based on the delivery of uncharacterized extracts or liquid conidia suspensions using aspiration or intranasal approaches. Studies that model exposure to dry fungal aerosols using whole body inhalation have only recently been described. In this study, we aimed to characterize pulmonary immune responses following repeated inhalation of conidia utilizing an acoustical generator to deliver dry fungal aerosols to mice housed in a nose only exposure chamber. Immunocompetent female BALB/cJ mice were exposed to conidia derived from Aspergillus fumigatus wild-type (WT) or a melanin-deficient (Δalb1) strain. Conidia were aerosolized and delivered to mice at an estimated deposition dose of 1×105 twice a week for 4 weeks (8 total). Histopathological and immunological endpoints were assessed 4, 24, 48, and 72 hours after the final exposure. Histopathological analysis showed that conidia derived from both strains induced lung inflammation, especially at 24 and 48 hour time points. Immunological endpoints evaluated in bronchoalveolar lavage fluid (BALF) and the mediastinal lymph nodes showed that exposure to WT conidia led to elevated numbers of macrophages, granulocytes, and lymphocytes. Importantly, CD8+ IL17+ (Tc17) cells were significantly higher in BALF and positively correlated with germination of A. fumigatus WT spores. Germination was associated with specific IgG to intracellular proteins while Δalb1 spores elicited antibodies to cell wall hydrophobin. These data suggest that inhalation exposures may provide a more representative analysis of immune responses following exposures to environmentally and occupationally prevalent fungal contaminants. PMID:25340353

  6. Maturation feeding and transmission of Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) by Monochamus alternatus (Coleoptera: Cerambycidae) inoculated with Beauveria bassiana (Deuteromycotina: Hyphomycetes).

    PubMed

    Maehara, Noritoshi; He, Xueyou; Shimazu, Mitsuaki

    2007-02-01

    We examined the amount of maturation feeding and transmission of pinewood nematodes, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle (Nematoda: Parasitaphelenchidae), to healthy pine (Pinus spp.) trees by pine sawyer Monochamus alternatus Hope (Coleoptera: Cerambycidae) adults infected with Beauveria bassiana (Balsamo) Vuill. (Deuteromycotina: Hyphomycetes). Inoculated beetles fed less than noninoculated beetles, probably because feeding by inoculated beetles began to decrease at about 4 d postinoculation and inoculated beetles ceased to feed for several days before their death. In inoculated beetles carrying >1,000 nematodes, some beetles died before nematode departure. The remaining heavily nematode-infested beetles lived until the beginning of nematode departure, but they had stopped feeding, preventing the nematodes from entering pine twigs. We suggest that microbial control of pine sawyer adults by B. bassiana may be effective in preventing transmission of pine wilt disease to healthy pine trees.

  7. Aquatic hyphomycete strains from metal-contaminated and reference streams might respond differently to future increase in temperature.

    PubMed

    Ferreira, Verónica; Gonçalves, Ana Lúcia; Canhoto, Cristina

    2012-01-01

    Aquatic hyphomycetes, a group of polyphyletic fungi, have been reported in streams contaminated with metals. This tolerance to metal contamination however can result in limited performance and limited ability to cope with additional environmental change. The predicted increase in water temperature, as a consequence of global warming, will have an additional effect on many streams. The sensitivity to temperature of strains of three aquatic hyphomycete species isolated from a metal-contaminated stream and an uncontaminated stream was assessed by determining their radial growth and activity (conidial production, oxygen consumption, mycelial biomass accumulation, fine particulate organic matter [FPOM] production, and microbial induced leaf mass loss) at 13 C (present water temperature in autumn) and at 18 C (predicted water temperature under global warming). Growth and reproductive activity generally were depressed for the strains isolated from the metal-contaminated stream when compared with those isolated from the unpolluted stream. These differences however were not translated into differences in FPOM production and leaf-litter mass loss, indicating that the strains isolated from the contaminated stream can decompose leaf litter similar to those of the reference stream. The 5 C increase in temperature stimulated fungal activity and litter decomposition, irrespective of species and strain. This might have strong effect on aquatic food-web and ecosystem functioning under global warming because increases in litter decomposition might lead to food shortage for higher trophic levels. The sensitivity to temperature depended on the response variable, species and strain. FPOM production was the variable most sensitive to temperature across strains and species and that for which temperature sensitivities differed most between strains. Fungal tolerance to metal contamination affects the extent to which its functions are stimulated by an increase in temperature, constituting

  8. A new species of Cladophialophora (hyphomycetes) from boreal and montane bryophytes.

    PubMed

    Davey, Marie L; Currah, Randolph S

    2007-01-01

    During a survey of bryophilous fungi from boreal and montane habitats in central Alberta, a hitherto undescribed species of Cladophialophora was recovered from Polytrichum juniperinum, Aulacomnium palustre, and Sphagnum fuscum. On potato dextrose agar (PDA) colonies grew slowly, attaining a diameter of 25 mm after 30 d, were dark grey, velvety, radially sulcate, and convolute and cracked at the centre. Micronematous conidiophores gave rise to branched chains of small (1-2 x 8-22 microm), cylindrical to fusiform conidia with truncate, swollen scars at each end. Phylogenies built on the ITS and ribosomal SSU regions indicate the isolates form a monophyletic clade within the family Herpotrichiellaceae (Chaetothyriales) that is composed of two geographically based groups, each with 99% within-group sequence similarity and 97-98% between-group sequence similarity. A teleomorph has not been found but would likely be similar to species of Capronia. In vitro inoculation of the isolates onto axenically grown P. juniperinum produced no discernible host symptoms, and host penetration could not be detected using light microscopy. The production of polyphenol oxidases by the fungus and the role of other Cladophialophora species as latent endophytes and saprobes suggest that a potential role for the fungus is the degradation of the polyphenol-rich cell walls of mosses. A dichotomous key to species of the genus Cladophialophora is provided.

  9. Susceptibility of biological stages of the horn fly, Haematobia irritans, to entomopathogenic fungi (Hyphomycetes)

    PubMed Central

    Angel-Sahagún, C. A.; Lezama-Gutiérrez, R.; Molina-Ochoa, J.; Galindo-Velasco, E.; López-Edwards, M.; Rebolledo-Domínguez, O.; Cruz-Vázquez, C.; Reyes-Velázquez, W. P.; Skoda, S. R.; Foster, J. E.

    2005-01-01

    The susceptibility of the egg, pupa, and adult of Haematobia irritans (L.) (Diptera: Muscidae) to isolates of the fungi Metarhizium anisopliae (Metsch.) Sor., Beauveria bassiana (Bals.) Vuill., and Paecilomyces fumosoroseus (Wize) Brown and Smith, was evaluated under laboratory conditions. Groups of 20 eggs than 4 h old, pupae less than 48h old and adults were sprayed with a conidial suspension of each isolate. Eggs, pupae and adults of horn fly were susceptible to these entomopathogenic fungi. For treated eggs, the isolates Ma3, Ma 15, Ma25, Pfr1, and Pfr8 reduced adult emergence to 3.8% to 6.3% in comparison with the control (72%). The mortality of pupae infected by the isolates Ma2, Ma25, and Pfr10 ranged between 50% and 71.3%. Mortality of adults after treatment with the isolates Ma6, Ma 10, Ma 14, Ma 15, Pfr 1, Pfr 9, Pfr 10, Pfr 11, and Pfr12 were higher than 90%. The isolate Ma6 produced the lowest LC50 against adult horn flies (8.08 × 102conidia/ml). These findings supported the hypotheses that isolates of M. anisopliae, and P. fumosoroseus are pathogenic against the different biological stages of horn flies by reducing adult emergence when applied on groups of eggs and pupae, and producing mortality when applied to adults. PMID:17119632

  10. Recognition of laminin by Paracoccidioides brasiliensis conidia: a possible mechanism of adherence to human type II alveolar cells.

    PubMed

    Caro, Erika; Gonzalez, Angel; Muñoz, César; Urán, Marta E; Restrepo, Angela; John Hamilton, Andrew; Elena Cano, Luz

    2008-12-01

    This study addresses the recognition of laminin by Paracoccidioides brasiliensis conidia, as well as its possible role in the adherence of conidia to A549 cells. Adherence of conidia to immobilized laminin was shown to be specific, as anti-laminin antibodies, soluble laminin or the laminin-derived peptides IKVAV and CDPGYIGSR inhibited this interaction. RGD containing peptides and various monosaccharides had no effect on adherence, with the exception of N-acetylneuraminic acid. Pre-treatment of conidia with fibrinogen and fibronectin, but not with BSA, also resulted in significant inhibition, suggesting that P. brasiliensis conidia might cross-recognize host proteins involved in colonization. In assays using transmission electron microscopy, we observed internalization of conidia 30 min after exposition to A549 cells. Laminin present on the surface of A549 cells shown to serve as mediator of this interaction, with a significant decrease in fungal adherence when the epithelial cells were pre-treated with anti-laminin antibodies or when conidia were pre-incubated with either soluble laminin or the laminin-specific peptides. Together these results suggest that the recognition of laminin by P. brasiliensis conidia is a key process in the interaction with pulmonary epithelial cells, where this extracellular matrix protein acts as bridging molecule.

  11. Temperature, water activity and pH during conidia production affect the physiological state and germination time of Penicillium species.

    PubMed

    Nguyen Van Long, Nicolas; Vasseur, Valérie; Coroller, Louis; Dantigny, Philippe; Le Panse, Sophie; Weill, Amélie; Mounier, Jérôme; Rigalma, Karim

    2017-01-16

    Conidial germination and mycelial growth are generally studied with conidia produced under optimal conditions to increase conidial yield. Nonetheless, the physiological state of such conidia most likely differs from those involved in spoilage of naturally contaminated food. The present study aimed at investigating the impact of temperature, pH and water activity (aw) during production of conidia on the germination parameters and compatible solutes of conidia of Penicillium roqueforti and Penicillium expansum. Low temperature (5°C) and reduced aw (0.900 aw) during sporulation significantly reduced conidial germination times whereas the pH of the sporulation medium only had a slight effect at the tested values (2.5, 8.0). Conidia of P. roqueforti produced at 5°C germinated up to 45h earlier than those produced at 20°C. Conidia of P. roqueforti and P. expansum produced at 0.900 aw germinated respectively up to 8h and 3h earlier than conidia produced at 0.980 aw. Furthermore, trehalose and mannitol assessments suggested that earlier germination might be related to delayed conidial maturation even though no ultra-structural modifications were observed by transmission electron microscopy. Taken together, these results highlight the importance of considering environmental conditions during sporulation in mycological studies. The physiological state of fungal conidia should be taken into account to design challenge tests or predictive mycology studies. This knowledge may also be of interest to improve the germination capacity of fungal cultures commonly used in fermented foods.

  12. Absorbing film assisted laser induced forward transfer of fungi (Trichoderma conidia)

    NASA Astrophysics Data System (ADS)

    Hopp, B.; Smausz, T.; Antal, Zs.; Kresz, N.; Bor, Zs.; Chrisey, D.

    2004-09-01

    We present an investigation on absorbing film assisted laser induced forward transfer (AFA-LIFT) of fungus (Trichoderma) conidia. A KrF excimer laser beam [λ =248nm,FWHM=30ns (FWHM, full width at half maximum)] was directed through a quartz plate and focused onto its silver coated surface where conidia of the Trichoderma strain were uniformly spread. The laser fluence was varied in the range of 0-2600mJ/cm2 and each laser pulse transferred a pixel of target material. The average irradiated area was 8×10-2mm2. After the transfer procedure, the yeast extract medium covered glass slide and the transferred conidia patterns were incubated for 20 h and then observed using an optical microscope. The transferred conidia pixels were germinated and the areas of the culture medium surfaces covered by the pixels were evaluated as a function of laser fluence. As the laser fluence was increased from 0 to 355mJ/cm2 the transferred and germinated pixel area increased from 0 to 0.25mm2. Further increase in fluence resulted in a drastic decrease down to an approximately constant value of 0.06mm2. The yield of successful transfer by AFA-LIFT and germination was as much as 75% at 355mJ/cm2. The results prove that AFA-LIFT can successfully be applied for the controlled transfer of biological objects.

  13. Evaluation of Soyscreen in an Oil-based Formulation for UV Protection of Beauveria bassiana Conidia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    SoyScreen oil was studied as a formulation ingredient to protect Beauveria bassiana (Balsamo) Vuillemin conidia from UV degradation. Feruloylated soy glycerides, referred to as SoyScreen oil, are biobased ultraviolet-absorbing molecules made by combining molecules of soybean oil with ferulic acid. ...

  14. Metacridamides A and B, bioactive macrocycles from conidia of the entomopathogenic fungus Metarhizium acridum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metarhizium acridum, an entomopathogenic fungus, has been commercialized and used successfully for biocontrol of grasshopper pests in Africa and Australia. Its conidia produce two novel 17-membered macrocycles, metacridamides A (1) and B (2), which consist of a Phe unit condensed with a nonaketide....

  15. Interactions of Aspergillus fumigatus Conidia with Airway Epithelial Cells: A Critical Review

    PubMed Central

    Croft, Carys A.; Culibrk, Luka; Moore, Margo M.; Tebbutt, Scott J.

    2016-01-01

    Aspergillus fumigatus is an environmental filamentous fungus that also acts as an opportunistic pathogen able to cause a variety of symptoms, from an allergic response to a life-threatening disseminated fungal infection. The infectious agents are inhaled conidia whose first point of contact is most likely to be an airway epithelial cell (AEC). The interaction between epithelial cells and conidia is multifaceted and complex, and has implications for later steps in pathogenesis. Increasing evidence has demonstrated a key role for the airway epithelium in the response to respiratory pathogens, particularly at early stages of infection; therefore, elucidating the early stages of interaction of conidia with AECs is essential to understand the establishment of infection in cohorts of at-risk patients. Here, we present a comprehensive review of the early interactions between A. fumigatus and AECs, including bronchial and alveolar epithelial cells. We describe mechanisms of adhesion, internalization of conidia by AECs, the immune response of AECs, as well as the role of fungal virulence factors, and patterns of fungal gene expression characteristic of early infection. A clear understanding of the mechanisms involved in the early establishment of infection by A. fumigatus could point to novel targets for therapy and prophylaxis. PMID:27092126

  16. Optimization of compatible non-ionic surfactant for formulation development of hydrophobic conidia of entomopathogenic fungi, Beauveria bassiana (Hypocreales:Cordycipitaceae) and Metarhizium anisopliae Hypocreales:Clavicipita

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerial conidia, especially dried conidia of entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae are hydrophobic, and therefore surfactants are needed for developing water-based formulations in laboratory studies, greenhouse bioassays, and field trials as well as commercial product ...

  17. Growth under visible light increases conidia and mucilage production and tolerance to UV-B radiation in the plant pathogenic fungus Colletotrichum acutatum.

    PubMed

    de Menezes, Henrique D; Massola, Nelson S; Flint, Stephan D; Silva, Geraldo J; Bachmann, Luciano; Rangel, Drauzio E N; Braga, Gilberto U L

    2015-01-01

    Light conditions can influence fungal development. Some spectral wavebands can induce conidial production, whereas others can kill the conidia, reducing the population size and limiting dispersal. The plant pathogenic fungus Colletotrichum acutatum causes anthracnose in several crops. During the asexual stage on the host plant, Colletototrichum produces acervuli with abundant mucilage-embedded conidia. These conidia are responsible for fungal dispersal and host infection. This study examined the effect of visible light during C. acutatum growth on the production of conidia and mucilage and also on the UV tolerance of these conidia. Conidial tolerance to an environmentally realistic UV irradiance was determined both in conidia surrounded by mucilage on sporulating colonies and in conidial suspension. Exposures to visible light during fungal growth increased production of conidia and mucilage as well as conidial tolerance to UV. Colonies exposed to light produced 1.7 times more conidia than colonies grown in continuous darkness. The UV tolerances of conidia produced under light were at least two times higher than conidia produced in the dark. Conidia embedded in the mucilage on sporulating colonies were more tolerant of UV than conidia in suspension that were washed free of mucilage. Conidial tolerance to UV radiation varied among five selected isolates.

  18. Inhibitory effect of deferoxamine or macrophage activation on transformation of Paracoccidioides brasiliensis conidia ingested by macrophages: reversal by holotransferrin.

    PubMed

    Cano, L E; Gomez, B; Brummer, E; Restrepo, A; Stevens, D A

    1994-04-01

    Conidia of P. brasiliensis ingested by murine macrophages at 37 degrees C showed enhanced transformation to yeast cells and further intracellular growth compared with conidia in culture medium alone. Treatment of macrophages with the iron chelator deferoxamine inhibited the intracellular conidium-to-yeast transformation. Cytokine-activated macrophages could also exert this inhibitory effect. Holotransferrin reversed the inhibitory effect of either deferoxamine or activated macrophages on intracellular conidium-to-yeast transformation. These results indicate that iron restriction is one of the mechanisms by which activated macrophages control the intracellular transformation of ingested conidia and growth of yeast cells.

  19. Inhibitory effect of deferoxamine or macrophage activation on transformation of Paracoccidioides brasiliensis conidia ingested by macrophages: reversal by holotransferrin.

    PubMed Central

    Cano, L E; Gomez, B; Brummer, E; Restrepo, A; Stevens, D A

    1994-01-01

    Conidia of P. brasiliensis ingested by murine macrophages at 37 degrees C showed enhanced transformation to yeast cells and further intracellular growth compared with conidia in culture medium alone. Treatment of macrophages with the iron chelator deferoxamine inhibited the intracellular conidium-to-yeast transformation. Cytokine-activated macrophages could also exert this inhibitory effect. Holotransferrin reversed the inhibitory effect of either deferoxamine or activated macrophages on intracellular conidium-to-yeast transformation. These results indicate that iron restriction is one of the mechanisms by which activated macrophages control the intracellular transformation of ingested conidia and growth of yeast cells. PMID:8132359

  20. Lag time for germination of Penicillium chrysogenum conidia is induced by temperature shifts.

    PubMed

    Kalai, Safaa; Bensoussan, Maurice; Dantigny, Philippe

    2014-09-01

    In the environment, fungal conidia are subject to transient conditions. In particular, temperature is varying according to day/night periods. All predictive models for germination assume that fungal spores can adapt instantaneously to changes of temperature. The only study that supports this assumption (Gougouli and Koutsoumanis, 2012, Modelling germination of fungal spores at constant and fluctuating temperature conditions. International Journal of Food Microbiology, 152: 153-161) was carried out on Penicillium expansum and Aspergillus niger conidia that, in most cases, already produced germ tubes. In contrast, the present study focuses on temperature shifts applied during the first stages of germination (i.e., before the apparition of the germ tubes). Firstly, germination times were determined in steady state conditions at 10, 15, 20 and 25 °C. Secondly, temperature shifts (e.g., up-shifts and down-shifts) were applied at 1/4, 1/2, and 3/4 of germination times, with 5, 10 and 15 °C magnitudes. Experiments were carried out in triplicate on Penicillium chrysogenum conidia on Potato Dextrose Agar medium according to a full factorial design. Statistical analysis of the results clearly demonstrated that the assumption of instantaneous adaptation of the conidia should be rejected. Temperature shifts during germination led to an induced lag time or an extended germination time as compared to the experiments conducted ay steady state. The induced lag time was maximized when the amplitude of the shift was equal to 10 °C. Interaction between the instant and the direction of the shift was highlighted. A negative lag time was observed for a 15 °C down-shift applied at 1/4 of the germination time. This result suggested that at optimal temperature the rate of germination decreased with time, and that the variation of this rate with time depended on temperature.

  1. Botrytis cinerea isolates collected from grapes present different requirements for conidia germination.

    PubMed

    Cotoras, Milena; García, Carolina; Mendoza, Leonora

    2009-01-01

    Botrytis cinerea presents high variability in several biological traits, which can be explained by the high degree of genotypic diversity among isolates. Because this genetic variability might be related to phenotypic differences the requirements for conidia germination of three natural isolates (G1, G5 and G11) obtained from grapes and belonging to the same genetic group were analyzed. The results showed that contact with a solid surface was a common requisite for conidia germination of the isolates but they differed in their nutritional requirements to germinate. Isolate G11 was able to germinate in the absence of a carbon or nitrogen source. G1 and G5 required the presence of a carbon source such as glucose, fructose or sucrose. In G11 and G5 isolates a much higher rate of germination was obtained in the presence of sucrose. It was shown with a pharmacological approach that the cAMP stimulated the germination only in those isolates requiring a carbon source. Conidia germination of G1 and G5 was inhibited by EGTA, a calcium chelator. Isolate G11 germinated in the presence of this compound. On the other hand the germination of three B. cinerea isolates required protein synthesis and did not require RNA synthesis. To explain the ability of isolate G11 to germinate in water the content of total and reducing sugars, mannitol/L-arabitol, trehalose, and proteins in the nongerminated conidia of the three isolates was compared. The isolates presented similar amounts of total and reducing sugars. In the three isolates the amount of mannitol/L-arabitol was higher than that of trehalose. In isolate G11 total protein content was twice higher than in the other isolates.

  2. Differential Regulation by Organic Compounds and Heavy Metals of Multiple Laccase Genes in the Aquatic Hyphomycete Clavariopsis aquatica

    PubMed Central

    Solé, Magali; Müller, Ines; Pecyna, Marek J.; Fetzer, Ingo; Harms, Hauke

    2012-01-01

    To advance the understanding of the molecular mechanisms controlling microbial activities involved in carbon cycling and mitigation of environmental pollution in freshwaters, the influence of heavy metals and natural as well as xenobiotic organic compounds on laccase gene expression was quantified using quantitative real-time PCR (qRT-PCR) in an exclusively aquatic fungus (the aquatic hyphomycete Clavariopsis aquatica) for the first time. Five putative laccase genes (lcc1 to lcc5) identified in C. aquatica were differentially expressed in response to the fungal growth stage and potential laccase inducers, with certain genes being upregulated by, e.g., the lignocellulose breakdown product vanillic acid, the endocrine disruptor technical nonylphenol, manganese, and zinc. lcc4 is inducible by vanillic acid and most likely encodes an extracellular laccase already excreted during the trophophase of the organism, suggesting a function during fungal substrate colonization. Surprisingly, unlike many laccases of terrestrial fungi, none of the C. aquatica laccase genes was found to be upregulated by copper. However, copper strongly increases extracellular laccase activity in C. aquatica, possibly due to stabilization of the copper-containing catalytic center of the enzyme. Copper was found to half-saturate laccase activity already at about 1.8 μM, in favor of a fungal adaptation to low copper concentrations of aquatic habitats. PMID:22544244

  3. Ecological study of Paracoccidioides brasiliensis in soil: growth ability, conidia production and molecular detection

    PubMed Central

    Terçarioli, Gisela Ramos; Bagagli, Eduardo; Reis, Gabriela Martins; Theodoro, Raquel Cordeiro; Bosco, Sandra De Moraes Gimenes; Macoris, Severino Assis da Graça; Richini-Pereira, Virgínia Bodelão

    2007-01-01

    Background Paracoccidioides brasiliensis ecology is not completely understood, although several pieces of evidence point to the soil as its most probable habitat. The present study aimed to investigate the fungal growth, conidia production and molecular pathogen detection in different soil conditions. Methods Soils samples of clayey, sandy and medium textures were collected from ground surface and the interior of armadillo burrows in a hyperendemic area of Paracoccidioidomycosis. P. brasiliensis was inoculated in soil with controlled humidity and in culture medium containing soil extracts. The molecular detection was carried out by Nested PCR, using panfungal and species specific primers from the ITS-5.8S rDNA region. Results The soil texture does not affect fungus development and the growth is more abundant on/in soil saturated with water. Some soil samples inhibited the development of P. brasiliensis, especially those that contain high values of Exchangeable Aluminum (H+Al) in their composition. Some isolates produced a large number of conidia, mainly in soil-extract agar medium. The molecular detection was positive only in samples collected from armadillo burrows, both in sandy and clayey soil. Conclusion P. brasiliensis may grow and produce the infectious conidia in sandy and clayey soil, containing high water content, mainly in wild animal burrows, but without high values of H+Al. PMID:17953742

  4. Effects of fluctuating moisture and temperature regimes on the persistence of quiescent conidia of Isaria fumosorosea.

    PubMed

    Bouamama, N; Vidal, C; Fargues, J

    2010-10-01

    Conidia of Isaria fumosorosea were submitted to three regimes of temperature and moisture to simulate microclimatic conditions which prevail in temperate (43% RH and 28 degrees C to 98% RH and 15 degrees C), subtropical (75% RH and 35 degrees C to 98% RH and 25 degrees C), and arid areas (13% RH and 40 degrees C to 33% RH and 15 degrees C) with daily fluctuating cycles. Germination, conidial viability, and virulence to Spodoptera frugiperda larvae were less affected after 20 days exposure under temperate cycling conditions than under arid and subtropical conditions. Exposure of conidia for 20 days to constant nocturnal simulated conditions of any tested regime weakly affected conidial persistence, whereas diurnal conditions exerted the most detrimental effects of high temperatures. However, when tested at both 45 degrees C and 50 degrees C at 33% RH for 160 h, the persistence of I. fumosorosea conidia was relatively higher than expected. These results emphasize that climatic conditions prevailing in environments and ecological fitness of fungal isolates have to be taken into account for assessing microbial control strategies.

  5. Fungal tyrosine betaine, a novel secondary metabolite from conidia of entomopathogenic Metarhizium spp. fungi.

    PubMed

    Carollo, Carlos A; Calil, Ana Luiza A; Schiave, Letícia A; Guaratini, Thais; Roberts, Donald W; Lopes, Norberto P; Braga, Gilberto U L

    2010-01-01

    Fungi, including the entomopathogenic deuteromycete Metarhizium anisopliae, produce a wide diversity of secondary metabolites that either can be secreted or stored in specific developmental structures, e.g., conidia. Some secondary metabolites, such as pigments, polyols and mycosporines, are associated with pathogenicity and/or fungal tolerance to several stress-inducing environmental factors, including temperature and solar radiation extremes. Extracts of M. anisopliae var. anisopliae (strain ESALQ-1037) conidia were purified by chromatographic procedures and the isolated compounds analyzed by ¹H and ¹³C nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. LC-MS analyses were carried out to search for mycosporines (the initial targets), but no compounds of this class were detected. A molecule whose natural occurrence was previously undescribed was identified. It consists of betaine conjugated with tyrosine, and the structure was identified as 2-{[1-carboxy-2-(4-hydroxyphenyl)ethyl]amino}-N,N,N-trimethyl-2-oxoethanammonium. Mannitol was the predominant compound in the alcoholic conidial extract, but no amino acids other than tyrosine were found to be conjugated with betaine in conidia. The fungal tyrosine betaine was detected also in conidial extracts of three other M. anisopliae var. anisopliae (ARSEF 1095, 5626 and 5749) and three M. anisopliae var. acridum isolates (ARSEF 324, 3391 and 7486), but it was not detected in Aspergillus nidulans conidial extract (ATCC 10074).

  6. Development of pulmonary fibrosis in mice during infection with Paracoccidioides brasiliensis conidia.

    PubMed

    Restrepo, S; Tobon, A; Trujillo, J; Restrepo, A

    1992-01-01

    Pulmonary fibrosis is a feared sequelae of paracoccidioidomycosis. We sought to determine if mice exposed to Paracoccidioides brasiliensis conidia would develop pulmonary fibrosis. BALB/c mice were infected intranasally with P. brasiliensis conidia and sacrificed at regular intervals. One lung was sectioned for histopathology and sections were stained with haematoxylin and eosin, trichromic and argentic stains; the other lung was homogenized and cultured to determine the viability of the fungus. One week post-challenge, only small peribronchial foci were apparent. After 4 weeks, reticular fibres appeared disorganized and disrupted. Six to 8 weeks later peribronchial infiltrates were larger and appeared surrounded by reticular fibres; thick collagen I fibres were noticed in the infiltrated areas at this time. On weeks 10-12, infiltrates were confluent and reticular fibres were concentrated around the inflammatory foci; collagenization was apparent. Observations up to 16 weeks revealed diffuse involvement of the lung parenchyma with extensive collagenization. Lung cultures were always positive. We suggest that inhalation of P. brasiliensis conidia induces adverse lung responses leading to changes in the proportion of collagen fibres I and III.

  7. Location of Aryl Sulfatase in Conidia and Young Mycelia of Neurospora crassa

    PubMed Central

    Scott, Walter A.; Metzenberg, Robert L.

    1970-01-01

    Aryl sulfatase (arylsulfate sulfohydrolase, EC 3.1.6.1) was found to have multiple locations in Neurospora conidia. Some enzyme activity remained in the supernatant when a spore suspension was centrifuged or filtered. Part of the cell-bound activity could be detected by adding the assay ingredients to a suspension of intact spores (patent enzyme), and additional activity was only detectable when the spores were first treated to destroy their permeability barriers (cryptic enzyme). Such treatments include: disruption with an X-press, brief rinsing with chloroform or acetone, incubation at 60 C for 5 min, and incubation with phenethyl alcohol, nystatin, or ascosin. Part of the patent aryl sulfatase was inactivated by briefly acid treating the intact spores (no loss of conidial viability). This enzyme was considered to have a cell surface location. Some enzyme was acid-resistant in intact spores, but all of the enzyme was acid-sensitive in spores whose permeability barriers had been disrupted. The pH dependence, kinetic properties, and p-nitrophenyl sulfate uptake were investigated in acid-treated conidia. No aryl sulfatase was detected in ascospores. Young mycelia contained more aryl sulfatase than did conidia, but little, if any, was secreted into the growth medium. Cryptic activity was demonstrated in young mycelia by brief chloroform treatment or by rinsing the cells with 0.1 m acetate buffer. Enzyme activity in young mycelia was completely labile to acid treatment, as was cell viability. PMID:16559101

  8. EVALUATION OF DIFFERENT METHODS FOR THE EXTRACTION OF DNA FROM FUNGAL CONIDIA BY QUANTITATIVE COMPETITIVE PCR ANALYSIS

    EPA Science Inventory

    Five different DNA extraction methods were evaluated for their effectiveness in recovering PCR templates from the conidia of a series of fungal species often encountered in indoor air. The test organisms were Aspergillus versicolor, Penicillium chrysogenum, Stachybotrys chartaru...

  9. Germination of Aspergillus niger conidia is triggered by nitrogen compounds related to L-amino acids.

    PubMed

    Hayer, Kimran; Stratford, Malcolm; Archer, David B

    2014-10-01

    Conidial germination is fundamentally important to the growth and dissemination of most fungi. It has been previously shown (K. Hayer, M. Stratford, and D. B. Archer, Appl. Environ. Microbiol. 79:6924-6931, 2013, http://dx.doi.org/10.1128/AEM.02061-13), using sugar analogs, that germination is a 2-stage process involving triggering of germination and then nutrient uptake for hyphal outgrowth. In the present study, we tested this 2-stage germination process using a series of nitrogen-containing compounds for the ability to trigger the breaking of dormancy of Aspergillus niger conidia and then to support the formation of hyphae by acting as nitrogen sources. Triggering and germination were also compared between A. niger and Aspergillus nidulans using 2-deoxy-D-glucose (trigger), D-galactose (nontrigger in A. niger but trigger in A. nidulans), and an N source (required in A. niger but not in A. nidulans). Although most of the nitrogen compounds studied served as nitrogen sources for growth, only some nitrogen compounds could trigger germination of A. niger conidia, and all were related to L-amino acids. Using L-amino acid analogs without either the amine or the carboxylic acid group revealed that both the amine and carboxylic acid groups were essential for an L-amino acid to serve as a trigger molecule. Generally, conidia were able to sense and recognize nitrogen compounds that fitted into a specific size range. There was no evidence of uptake of either triggering or nontriggering compounds over the first 90 min of A. niger conidial germination, suggesting that the germination trigger sensors are not located within the spore.

  10. Methods for reducing particle concentrations of Aspergillus fumigatus conidia and mouldy hay dust.

    PubMed

    Edwards, J H; Trotman, D M; Mason, O F

    1985-08-01

    The effectiveness of commercially available domestic air purifiers to reduce airborne Aspergillus fumigatus conidia and mouldy hay dust was investigated. It was found that the rate of particle clearance is a function of the volume of air passing through the purifiers but that the low throughflow of air makes their use of little value in clearing particles from a normal sized room. Vacuum cleaners were more effective than air purifiers because of their higher air throughput, so too were high volume fan systems in conjunction with simple filtration units. Ionizers had no effect but steam condensation was very efficient at clearing airborne particles.

  11. Conidia of the insect pathogenic fungus, Metarhizium anisopliae, fail to adhere to mosquito larval cuticle

    PubMed Central

    Greenfield, Bethany P. J.; Lord, Alex M.; Dudley, Ed; Butt, Tariq M.

    2014-01-01

    Adhesion of conidia of the insect pathogenic fungus, Metarhizium anisopliae, to the arthropod host cuticle initially involves hydrophobic forces followed by consolidation facilitated by the action of extracellular enzymes and secretion of mucilage. Gene expression analysis and atomic force microscopy were used to directly quantify recognition and adhesion between single conidia of M. anisopliae and the cuticle of the aquatic larval stage of Aedes aegypti and a representative terrestrial host, Tenebrio molitor. Gene expression data indicated recognition by the pathogen of both hosts; however, the forces for adhesion to the mosquito were approximately five times lower than those observed for Tenebrio. Although weak forces were recorded in response to Aedes, Metarhizium was unable to consolidate firm attachment. An analysis of the cuticular composition revealed an absence of long-chain hydrocarbons in Aedes larvae which are thought to be required for fungal development on host cuticle. This study provides, to our knowledge, the first evidence that Metarhizium does not form firm attachment to Ae. aegypti larvae in situ, therefore preventing the normal route of invasion and pathogenesis from occuring. PMID:26064542

  12. A Non-canonical Melanin Biosynthesis Pathway Protects Aspergillus terreus Conidia from Environmental Stress.

    PubMed

    Geib, Elena; Gressler, Markus; Viediernikova, Iuliia; Hillmann, Falk; Jacobsen, Ilse D; Nietzsche, Sandor; Hertweck, Christian; Brock, Matthias

    2016-05-19

    Melanins are ubiquitous pigments found in all kingdoms of life. Most organisms use them for protection from environmental stress, although some fungi employ melanins as virulence determinants. The human pathogenic fungus Aspergillus fumigatus and related Ascomycetes produce dihydroxynaphthalene- (DHN) melanin in their spores, the conidia, and use it to inhibit phagolysosome acidification. However, biosynthetic origin of melanin in a related fungus, Aspergillus terreus, has remained a mystery because A. terreus lacks genes for synthesis of DHN-melanin. Here we identify genes coding for an unusual NRPS-like enzyme (MelA) and a tyrosinase (TyrP) that A. terreus expressed under conidiation conditions. We demonstrate that MelA produces aspulvinone E, which is activated for polymerization by TyrP. Functional studies reveal that this new pigment, Asp-melanin, confers resistance against UV light and hampers phagocytosis by soil amoeba. Unexpectedly, Asp-melanin does not inhibit acidification of phagolysosomes, thus likely contributing specifically to survival of A. terreus conidia in acidic environments.

  13. Thermal inactivation of Botrytis cinerea conidia in synthetic medium and strawberry puree.

    PubMed

    Villa-Rojas, R; Sosa-Morales, M E; López-Malo, A; Tang, J

    2012-04-16

    Botrytis cinerea is one of the most important post-harvest molds that cause quality deterioration of strawberries and other fruits even during refrigeration storage. This research studied the effects of thermal inactivation of B. cinerea in synthetic medium and strawberry puree using hot water baths at different temperatures. These media were studied in order to determine if results obtained in a solution with the major components of the fruit (synthetic media), are comparable to the ones obtained in fruit purees. The results demonstrated that B. cinerea spores can be inactivated by heat treatments using relatively low temperatures (42-46 °C). Inactivation curves were well described by first order kinetics (R² 0.91-0.99). B. cinerea conidia inoculated in synthetic medium required less time to achieve one log reduction in population than those inoculated in the fruit puree. D values were 22, 8.5, 4 and 1.4 min at 42, 44, 46 and 48 °C, respectively, in synthetic medium; while D values in strawberry puree were 44.9, 13.8, 4.7 and 1.4 min at 42, 44, 46 and 48 °C, respectively. The z values obtained were 4.15 and 5.08 °C for the strawberry puree and synthetic medium respectively, showing higher sensitivity of B. cinerea in fruit purees than in the synthetic medium. Thus, a change in the medium composition had a marked difference in the heat inactivation of B. cinerea conidia, and the results obtained in synthetic medium are not accurate to describe the behavior of the microorganism in the fruit.

  14. A Quantitative Dynamic Simulation of Bremia lactucae Airborne Conidia Concentration above a Lettuce Canopy

    PubMed Central

    Fall, Mamadou Lamine; Van der Heyden, Hervé; Carisse, Odile

    2016-01-01

    Lettuce downy mildew, caused by the oomycete Bremia lactucae Regel, is a major threat to lettuce production worldwide. Lettuce downy mildew is a polycyclic disease driven by airborne spores. A weather-based dynamic simulation model for B. lactucae airborne spores was developed to simulate the aerobiological characteristics of the pathogen. The model was built using the STELLA platform by following the system dynamics methodology. The model was developed using published equations describing disease subprocesses (e.g., sporulation) and assembled knowledge of the interactions among pathogen, host, and weather. The model was evaluated with four years of independent data by comparing model simulations with observations of hourly and daily airborne spore concentrations. The results show an accurate simulation of the trend and shape of B. lactucae temporal dynamics of airborne spore concentration. The model simulated hourly and daily peaks in airborne spore concentrations. More than 95% of the simulation runs, the daily-simulated airborne conidia concentration was 0 when airborne conidia were not observed. Also, the relationship between the simulated and the observed airborne spores was linear. In more than 94% of the simulation runs, the proportion of the linear variation in the hourly-observed values explained by the variation in the hourly-simulated values was greater than 0.7 in all years except one. Most of the errors came from the deviation from the 1:1 line, and the proportion of errors due to the model bias was low. This model is the only dynamic model developed to mimic the dynamics of airborne inoculum and represents an initial step towards improved lettuce downy mildew understanding, forecasting and management. PMID:26953691

  15. A proteomic approach to identifying proteins differentially expressed in conidia and mycelium of the entomopathogenic fungus Metarhizium acridum.

    PubMed

    Barros, Bruno H R; da Silva, Sérgio H; dos ReisMarques, Everaldo Dos Reis; Rosa, José C; Yatsuda, Ana Patrícia; Roberts, Donald W; Braga, Gilberto U L

    2010-07-01

    Metarhizium spp. is an important worldwide group of entomopathogenic fungi used as an interesting alternative to chemical insecticides in programs of agricultural pest and disease vector control. Metarhizium conidia are important in fungal propagation and also are responsible for host infection. Despite their importance, several aspects of conidial biology, including their proteome, are still unknown. We have established conidial and mycelial proteome reference maps for Metarhizium acridum using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF MS). In all, 1130±102 and 1200±97 protein spots were detected in ungerminated conidia and fast-growing mycelia, respectively. Comparison of the two protein-expression profiles reveled that only 35% of the protein spots were common to both developmental stages. Out of 94 2-DE protein spots (65 from conidia, 25 from mycelia and two common to both) analyzed using mass spectrometry, seven proteins from conidia, 15 from mycelia and one common to both stages were identified. The identified protein spots exclusive to conidia contained sequences similar to known fungal stress-protector proteins (such as heat shock proteins (HSP) and 6-phosphogluconate dehydrogenase) plus the fungal allergen Alt a 7, actin and the enzyme cobalamin-independent methionine synthase. The identified protein spots exclusive to mycelia included proteins involved in several cell housekeeping biological processes. Three proteins (HSP 90, 6-phosphogluconate dehydrogenase and allergen Alt a 7) were present in spots in conidial and mycelial gels, but they differed in their locations on the two gels.

  16. Influence of mechanical stress and surface interaction on the aggregation of Aspergillus niger conidia.

    PubMed

    Grimm, L H; Kelly, S; Völkerding, I I; Krull, R; Hempel, D C

    2005-12-30

    Productivity of fungal cultures is closely linked with their morphologic development. Morphogenesis of coagulating filamentous fungi, like Aspergillus niger, starts with aggregation of conidia, also denominated as spores. Several parameters are presumed to control this event, but little is known about their mode of action. Rational process optimization requires models that mirror the underlying reaction mechanisms. An approach in this regard is suggested and supported by experimental data. Aggregation kinetics was examined for the first 15 h of cultivation under different cultivation conditions. Mechanical stress was considered as well as pH-dependent surface interaction. Deliberations were based on a two-step aggregation mechanism. The first aggregation step is only affected by the pH-value, not by the fluid dynamic conditions in the bioreactor. The second aggregation step, in contrast, depends on the pH-value as well as on agitation and aeration induced power input. For the given experimental set-up, agitation had much more influence than aeration. In addition, hyphal growth rate was determined to be the driving force for the second aggregation step.

  17. IL-1 signaling inhibits Trichophyton rubrum conidia development and modulates the IL-17 response in vivo.

    PubMed

    Yoshikawa, Fábio Seiti Yamada; Ferreira, Lucas Gonçalves; de Almeida, Sandro Rogério

    2015-01-01

    Dermatophytosis are one of the most common fungal infections in the world. They compromise keratinized tissues and the main etiological agent is Trichophyton rubrum. Macrophages are key cells in innate immunity and prominent sources of IL-1β, a potent inflammatory cytokine whose main production pathway is by the activation of inflammasomes and caspase-1. However, the role of inflammasomes and IL-1 signaling against T.rubrum has not been reported. In this work, we observed that bone marrow-derived macrophages produce IL-1β in response to T.rubrum conidia in a NLRP3-, ASC- and caspase-1-dependent fashion. Curiously, lack of IL-1 signaling promoted hyphae development, uncovering a protective role for IL-1β in macrophages. In addition, mice lacking IL-1R showed reduced IL-17 production, a key cytokine in the antifungal defense, in response to T.rubrum. Our findings point to a prominent role of IL-1 signaling in the immune response to T.rubrum, opening the venue for the study of this pathway in other fungal infections.

  18. A novel approach of utilization of the fungal conidia biomass to remove heavy metals from the aqueous solution through immobilization

    NASA Astrophysics Data System (ADS)

    Cai, Chun-Xiang; Xu, Jian; Deng, Nian-Fang; Dong, Xue-Wei; Tang, Hao; Liang, Yu; Fan, Xian-Wei; Li, You-Zhi

    2016-11-01

    The biomass of filamentous fungi is an important cost-effective biomass for heavy metal biosorption. However, use of free fungal cells can cause difficulties in the separation of biomass from the effluent. In this study, we immobilized the living conidia of the heavy metal-resistant Penicillium janthinillum strain GXCR by polyvinyl alcohol (PVA)-sodium alginate (SA) beads to remove heavy metals from an aqueous solution containing a low concentration (70 mg/L) of Cu, Pb, and Cd. The PVA-SA-conidia beads showed perfect characters of appropriate mechanical strength suitable for metal removal from the dynamic wastewater environment, an ideal settleability, easy separation from the solution, and a high metal biosorption and removal rate even after four cycles of successive sorption-desorption of the beads, overcoming disadvantages when fungal biomasses alone are used for heavy metal removal from wastewater. We also discuss the major biosorption-affecting factors, biosorption models, and biosorption mechanisms.

  19. A novel approach of utilization of the fungal conidia biomass to remove heavy metals from the aqueous solution through immobilization

    PubMed Central

    Cai, Chun-Xiang; Xu, Jian; Deng, Nian-Fang; Dong, Xue-Wei; Tang, Hao; Liang, Yu; Fan, Xian-Wei; Li, You-Zhi

    2016-01-01

    The biomass of filamentous fungi is an important cost-effective biomass for heavy metal biosorption. However, use of free fungal cells can cause difficulties in the separation of biomass from the effluent. In this study, we immobilized the living conidia of the heavy metal-resistant Penicillium janthinillum strain GXCR by polyvinyl alcohol (PVA)-sodium alginate (SA) beads to remove heavy metals from an aqueous solution containing a low concentration (70 mg/L) of Cu, Pb, and Cd. The PVA-SA-conidia beads showed perfect characters of appropriate mechanical strength suitable for metal removal from the dynamic wastewater environment, an ideal settleability, easy separation from the solution, and a high metal biosorption and removal rate even after four cycles of successive sorption-desorption of the beads, overcoming disadvantages when fungal biomasses alone are used for heavy metal removal from wastewater. We also discuss the major biosorption-affecting factors, biosorption models, and biosorption mechanisms. PMID:27848987

  20. Arthromyces and Blastosporella, two new genera of conidia-producing lyophylloid agarics (Agaricales, Basidiomycota) from the neotropics.

    PubMed

    Baroni, Timothy J; Franco-Molano, Ana Esperanza; Lodge, D Jean; Lindner, Daniel L; Horak, Egon; Hofstetter, Valerie

    2007-05-01

    Two new genera encompassing three new species of lyophylloid agarics that produce conidia on the basidiomata are described. Arthromyces is a genus comprised of two very different arthrospore-producing mushroom species found in the Greater Antilles and Central America. Blastosporella is a monotypic genus with spherical balls of blastospores covering the pileus surface with age and is known from Hispaniola and Colombia. A key to the species of Arthromyces is included.

  1. Surface structure characterization of Aspergillus fumigatus conidia mutated in the melanin synthesis pathway and their human cellular immune response.

    PubMed

    Bayry, Jagadeesh; Beaussart, Audrey; Dufrêne, Yves F; Sharma, Meenu; Bansal, Kushagra; Kniemeyer, Olaf; Aimanianda, Vishukumar; Brakhage, Axel A; Kaveri, Srini V; Kwon-Chung, Kyung J; Latgé, Jean-Paul; Beauvais, Anne

    2014-08-01

    In Aspergillus fumigatus, the conidial surface contains dihydroxynaphthalene (DHN)-melanin. Six-clustered gene products have been identified that mediate sequential catalysis of DHN-melanin biosynthesis. Melanin thus produced is known to be a virulence factor, protecting the fungus from the host defense mechanisms. In the present study, individual deletion of the genes involved in the initial three steps of melanin biosynthesis resulted in an altered conidial surface with masked surface rodlet layer, leaky cell wall allowing the deposition of proteins on the cell surface and exposing the otherwise-masked cell wall polysaccharides at the surface. Melanin as such was immunologically inert; however, deletion mutant conidia with modified surfaces could activate human dendritic cells and the subsequent cytokine production in contrast to the wild-type conidia. Cell surface defects were rectified in the conidia mutated in downstream melanin biosynthetic pathway, and maximum immune inertness was observed upon synthesis of vermelone onward. These observations suggest that although melanin as such is an immunologically inert material, it confers virulence by facilitating proper formation of the A. fumigatus conidial surface.

  2. The pbrB gene encodes a laccase required for DHN-melanin synthesis in conidia of Talaromyces (Penicillium) marneffei.

    PubMed

    Sapmak, Ariya; Boyce, Kylie J; Andrianopoulos, Alex; Vanittanakom, Nongnuch

    2015-01-01

    Talaromyces marneffei (Basionym: Penicillium marneffei) is a significant opportunistic fungal pathogen in patients infected with human immunodeficiency virus in Southeast Asia. T. marneffei cells have been shown to become melanized in vivo. Melanins are pigment biopolymers which act as a non-specific protectant against various stressors and which play an important role during virulence in fungi. The synthesis of the two most commonly found melanins in fungi, the eumelanin DOPA-melanin and the allomelanin DHN-melanin, requires the action of laccase enzymes. The T. marneffei genome encodes a number of laccases and this study describes the characterization of one of these, pbrB, during growth and development. A strain carrying a PbrB-GFP fusion shows that pbrB is expressed at high levels during asexual development (conidiation) but not in cells growing vegetatively. The pbrB gene is required for the synthesis of DHN-melanin in conidia and when deleted results in brown pigmented conidia, in contrast to the green conidia of the wild type.

  3. Aspergillus fumigatus germ tube growth and not conidia ingestion induces expression of inflammatory mediator genes in the human lung epithelial cell line A549.

    PubMed

    Bellanger, Anne-Pauline; Millon, Laurence; Khoufache, Khaled; Rivollet, Danièle; Bièche, Ivan; Laurendeau, Ingrid; Vidaud, Michel; Botterel, Françoise; Bretagne, Stéphane

    2009-02-01

    Inhalation of conidia is the main cause of invasive pulmonary aspergillosis (IPA) and the respiratory epithelium is the first line of defence. To explore the triggering factor for the inflammatory response to Aspergillus fumigatus, the species mainly responsible for IPA, this study analysed the differential expression of three inflammatory genes in A549 cells after challenge with live and killed conidia. The influence of steroids, one of the main risk factors for developing IPA, was also investigated. Quantification of mRNAs of the inflammatory mediator genes encoding interleukin (IL)-8, tumour necrosis factor (TNF)-alpha and granulocyte-monocyte colony-stimulating factor (GM-CSF) was carried out using real-time PCR. Ingestion rates were studied for the conidia of A. fumigatus and Penicillium chrysogenum using a fluorescence brightener. Similar results were obtained for both species, with ingestion rates ranging from 35 to 40 %. Exposure of A549 cells to live A. fumigatus conidia only induced a four- to fivefold increase in the mRNA levels of the three genes, starting 8 h after the initial contact. Both inactivation of live A. fumigatus conidia and treatment by dexamethasone (10(-7) M) prevented the overexpression of TNF-alpha, IL-8 and GM-CSF. Fungal growth, rather than conidia ingestion, appears to be the main stimulus for the production of inflammatory mediators by epithelial cells, and this production is inhibited by steroid therapy. These results underline the role that the epithelium plays in the innate response against IPA.

  4. Intact Cell/Spore Mass Spectrometry of Fusarium Macro Conidia for Fast Isolate and Species Differentiation

    NASA Astrophysics Data System (ADS)

    Dong, Hongjuan; Marchetti-Deschmann, Martina; Winkler, Wolfgang; Lohninger, Hans; Allmaier, Guenter

    The focus of this paper is the development of an approach called intact cell mass spectrometry (ICMS) or intact spore mass spectrometry (ISMS) based on the technique matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for the rapid differentiation and identification of Fusarium species. Several parameters, which are known to affect the quality of IC mass spectra, have been investigated in detail by varying the MALDI matrix as well as the solvent system, in which the matrix has been dissolved, the solvent system for sample purification and the type of sample/MALDI matrix deposition technique. In the end characteristic as well as highly reproducible IC or IS mass spectra or peptide/protein fingerprints of three Fusarium species (F. cerealis, F. graminearum and F. poae) including 16 Fusarium isolates derived from different hosts and geographical locations have been obtained. Unscaled hierarchical cluster analysis based on ICMS data of eight selected Fusarium isolates of two species F. graminearum and F. poae revealed significant difference among the peptide/protein pattern of them. The results of the applied cluster analysis proved that, ICMS is a powerful approach for the rapid differentiation of Fusarium species. In addition, an on-target tryptic digestion was applied to Fusarium macro conidia spores to identify proteins using MALDI post source decay (PSD) fragment ion analysis. Two kinds of trypsin, namely bead-immobilized - to favor cleavage of surface-associated proteins - and non-immobilized trypsin were applied and compared. The results showed that the latter is more suitable for generating sequence tags by PSD fragment ion analysis.

  5. Taxonomy, nomenclature and phylogeny of three cladosporium-like hyphomycetes, Sorocybe resinae, Seifertia azaleae and the Hormoconis anamorph of Amorphotheca resinae

    PubMed Central

    Seifert, K.A.; Hughes, S.J.; Boulay, H.; Louis-Seize, G.

    2007-01-01

    Using morphological characters, cultural characters, large subunit and internal transcribed spacer rDNA (ITS) sequences, and provisions of the International Code of Botanical Nomenclature, this paper attempts to resolve the taxonomic and nomenclatural confusion surrounding three species of cladosporium-like hyphomycetes. The type specimen of Hormodendrum resinae, the basis for the use of the epithet resinae for the creosote fungus {either as Hormoconis resinae or Cladosporium resinae) represents the mononematous synanamorph of the synnematous, resinicolous fungus Sorocybe resinae. The phylogenetic relationships of the creosote fungus, which is the anamorph of Amorphotheca resinae, are with the family Myxotrichaceae, whereas S. resinae is related to Capronia (Chaetothyriales, Herpotrichiellaceae). Our data support the segregation of Pycnostysanus azaleae, the cause of bud blast of rhododendrons, in the recently described anamorph genus Seifertia, distinct from Sorocybe; this species is related to the Dothideomycetes but its exact phylogenetic placement is uncertain. To formally stabilize the name of the anamorph of the creosote fungus, conservation of Hormodendrum resinae with a new holotype should be considered. The paraphyly of the family Myxotrichaceae with the Amorphothecaceae suggested by ITS sequences should be confirmed with additional genes. PMID:18491002

  6. [Variation in the viability and the metabolism of internally reserved nutrients of Beauveria bassiana conidia during storage at different regimes of water content and temperature].

    PubMed

    Feng, Mingguang; Ying, Shenghua

    2002-04-01

    While the fresh powder (with water content of 58.9 +/- 1.6%) and vacuum-freeze dried (VFD) one (with water content of 7.4 +/- 0.9%) of Beauveria bassiana SGBB8702 conidia were stored at 4 degrees C and 20 degrees C, their viability and contents of internally reserved saccharides and proteins were examined at 5 days intervals. It was found during one-month storage that the water content and temperature interactively affected the levels of conidia viability and the contents of the reserved saccharides and proteins, which in turn correlated considerably well to the viability. Stored at 4 degrees C and 20 degrees C, the VFD conidia lost content of saccharides by 13.4% and 14.1%, content of proteins by 39.2% and 38.2%, and viability by 32.0% and 55.8% when germinating in water only and 6.7% and 10.4% when germinating in 2% glucose solution plus 0.5% peptone, respectively. In contrast, the four estimates of the fresh conidia stored at 4 degrees C and 20 degrees C decreased by 42.4% and 43.2%, 66.3% and 65.4%, 96.4% and 99.4%, and 9.9% and 98.4%, respectively. Thus, water content of B. bassiana conidia affected variation ranges of the viability and the internally reserved nutrients whereas storage temperature influenced their variation rates. However, depletion of the internally reserved nutrients did not necessarily inactivate the conidia. Instead, such conidia may germinate at relatively high level during a period of time as long as being supplied with sufficient nutrients. In another experiment, the powder of VFD conidia with water content being reduced to 4.0 +/- 0.9% were half-monthly examined for viability during one-year storage. The viability only decreased slightly from 99.0% to 90.2% at 4 degrees C by the end of one year. Stored at 20 degrees C, the viability also declined slowly during the first 165 days but dramatically decreased afterwards with little being detected on day 240. A modeling analysis showed that the time for the VFD conidia to lose 50% viability

  7. Hypocrea rufa/Trichoderma viride: a reassessment, and description of five closely related species with and without warted conidia

    PubMed Central

    Jaklitsch, Walter M.; Samuels, Gary J.; Dodd, Sarah L.; Lu, Bing-Sheng; Druzhinina, Irina S.

    2006-01-01

    The type species of the genus Hypocrea (Hypocreaceae, Hypocreales, Ascomycota, Fungi), H. rufa, is re-defined and epitypified using a combination of phenotype (morphology of teleomorphs and anamorphs, and characteristics in culture) and phylogenetic analyses of the translation-elongation factor 1α gene. Its anamorph, T. viride, the type species of Trichoderma, is re-described and epitypified. Eidamia viridescens is combined as Trichoderma viridescens and is recognised as one of the most morphologically and phylogenetically similar relatives of T. viride. Its teleomorph is newly described as Hypocrea viridescens. Contrary to frequent citations of H. rufa and T. viride in the literature, this species is relatively rare. Although both T. viride and T. viridescens have a wide geographic distribution, their greatest genetic diversity appears to be in Europe and North America. Hypocrea vinosa is characterised and its anamorph, T. vinosum sp. nov., is described. Conidia of T. vinosum are subglobose and warted. The new species T. gamsii is proposed. It shares eidamia-like morphology of conidiophores with T. viridescens, but it has smooth, ellipsoidal conidia that have the longest L/W ratio that we have seen in Trichoderma. Trichoderma scalesiae, an endophyte of trunks of Scalesia pedunculata in the Galapagos Islands, is described as new. It only produces conidia on a low-nutrient agar to which filter paper has been added. Additional phylogenetically distinct clades are recognised and provisionally delimited from the species here described. Trichoderma neokoningii, a T. koningii-like species, is described from a collection made in Peru on a fruit of Theobroma cacao infected with Moniliophthora roreri. PMID:18490991

  8. Binding of live conidia of Aspergillus fumigatus activates in vitro-generated human Langerhans cells via a lectin of galactomannan specificity

    PubMed Central

    PERSAT, F; NOIREY, N; DIANA, J; GARIAZZO, M-J; SCHMITT, D; PICOT, S; VINCENT, C

    2003-01-01

    Aspergillus fumigatus is the most common aetiological fungus responsible for human pulmonary aspergilloses. This study investigated the primary contact between Langerhans cells (LC), corresponding to dendritic cells present in pulmonary mucosa and live conidia of A. fumigatus. LC play a key role in antigen presentation for initiation of the primary T cell response. In vitro-generated LC (iLC) were differentiated from cultured human cord blood CD34+ cells and incubated at 4°C or 37°C with fluorescein-isothiocyanate (FITC)-stained conidia or control latex beads. In vitro, conidia were shown by microscopy and cytometry to adhere to iLC in a dose- and time-dependent manner. This adhesion was not limited to iLC because interstitial dendritic and other cells also fluoresced in the presence of conidia-FITC. A lectin other than mannose receptor-type lectin was demonstrated to be responsible of conidial binding. Inhibition of binding was observed with heterologous galactomannan and EDTA, indicating a C-lectin-like receptor with galactomannan structure specificity. After binding only a few conidia were internalized in acidic vesicles, as indicated by the cessation of conidial fluorescence. Conidial binding was followed by activation and maturation of iLC, suggesting that LC present in the lung may play a role in cellular host defence against aspergilloses. PMID:12930363

  9. Field trials using the fungal pathogen, Metarhizium anisopliae (Deuteromycetes: Hyphomycetes) to control the ectoparasitic mite, Varroa destructor (Acari: Varroidae) in honey bee, Apis mellifera (Hymenoptera: Apidae) colonies.

    PubMed

    Kanga, Lambert Houssou Ble; Jones, Walker A; James, Rosalind R

    2003-08-01

    The potential for Metarhizium anisopliae (Metschinkoff) to control the parasitic mite, Varroa destructor (Anderson and Trueman) in honey bee colonies was evaluated in field trials against the miticide, tau-fluvalinate (Apistan). Peak mortality of V. destructor occurred 3-4 d after the conidia were applied; however, the mites were still infected 42 d posttreatments. Two application methods were tested: dusts and strips coated with the fungal conidia, and both methods resulted in successful control of mite populations. The fungal treatments were as effective as the Apistan, at the end of the 42-d period of the experiment. The data suggested that optimum mite control could be achieved when no brood is being produced, or when brood production is low, such as in the early spring or late fall. M. anisopliae was harmless to the honey bees (adult bees, or brood) and colony development was not affected. Mite mortality was highly correlated with mycosis in dead mites collected from sticky traps, indicating that the fungus was infecting and killing the mites. Because workers and drones drift between hives, the adult bees were able to spread the fungus between honey bee colonies in the apiary, a situation that could be beneficial to beekeepers.

  10. Effects of resveratrol on the ultrastructure of Botrytis cinerea conidia and biological significance in plant/pathogen interactions.

    PubMed

    Adrian, Marielle; Jeandet, Philippe

    2012-12-01

    Many roles have been ascribed to stilbenes, namely as antimicrobial, deterrent or repellent compounds in plants, protecting them from attacks by fungi, bacteria, nematodes or herbivores, acting both as constitutive and active defense (phytoalexin) compounds. More recently, stilbenes (especially resveratrol and its derivatives) were acclaimed for their wondrous effects and wide range of purported healing and preventive powers as cardioprotective, antitumor, neuroprotective and antioxidant agents. Although there is a huge number of works concerning the role of resveratrol in human health, reports on the antifungal activity of this compound are still scarce. This study was thus conducted in order to investigate the toxicity of resveratrol at an ultra- structural level to dormant conidia of Botrytis cinerea, the causal microorganism for gray mold. In grapevine particularly, this disease can affect all the green organs but is particularly damaging for ripening berries. Observations using transmission electron microscopy showed the occurrence of damages on conidia treated with sub-lethal doses, that is, 60μg/mL (2.6×10(-4)M) of resveratrol, a concentration usually reached in grapevine leaves and grape berries challenged by this pathogen. These results provide further data about the overall mode of action of this phytoalexin and its role in the B. cinerea/grapevine interaction.

  11. Yield and cold storage of Trichoderma conidia is influenced by substrate pH and storage temperature.

    PubMed

    Steyaert, Johanna M; Chomic, Anastasia; Nieto-Jacobo, Maria; Mendoza-Mendoza, Artemio; Hay, Amanda J; Braithwaite, Mark; Stewart, Alison

    2017-02-17

    In this study we examined the influence of the ambient pH during morphogenesis on conidial yield of Trichoderma sp. "atroviride B" LU132 and T. hamatum LU593 and storage at low temperatures. The ambient pH of the growth media had a dramatic influence on the level of Trichoderma conidiation and this was dependent on the strain and growth media. On malt-extract agar, LU593 yield decreased with increasing pH (3-6), whereas yield increased with increasing pH for LU132. During solid substrate production the reverse was true for LU132 whereby yield decreased with increasing pH. The germination potential of the conidia decreased significantly over time in cold storage and the rate of decline was a factor of the strain, pH during morphogenesis, growth media, and storage temperature.

  12. A soluble fucose-specific lectin from Aspergillus fumigatus conidia--structure, specificity and possible role in fungal pathogenicity.

    PubMed

    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. Application of hydrophilic-lypophilic balance (HLB) number to optimize a compatible non-ionic surfactant for dried aerial conidia of Beauveria bassiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hydrophilic-lipophilic balance (HLB) number system was used to optimize a compatible non-ionic surfactant, TDA(polyoxyethylene tridecyl ether) in formulations for two Beauveria bassiana strains, NI8 and GHA. The optimal HLB number for TDA was determined on the basis of wetting times for conidia...

  14. A proposed role for the cuticular fatty amides of Liposcelis bostrychophila (Psocoptera: Liposcelidae) in preventing adhesion of entomopathogenic fungi with dry-conidia.

    PubMed

    Lord, Jeffrey C; Howard, Ralph W

    2004-08-01

    Maximum challenge exposure of Liposcelis bostrychophila to Beauveria bassiana, Paecilomyces fumosoroseus, Aspergillus parasiticus or Metarhizium anisopliae resulted in no more than 16% mortality. We investigated several of L. bostrychophila's cuticular lipids for possible contributions to its tolerance for entomopathogenic fungi. Saturated C14 and C16 fatty acids did not reduce the germination rates of B. bassiana or M. anisopliae conidia. Saturated C6 to C12 fatty acids that have not been identified in L. bostrychophila cuticular extracts significantly reduced germination, but the reduction was mitigated by the presence of stearamide. Cis-6-hexadecenal did not affect germination rates. Mycelial growth of either fungal species did not occur in the presence of caprylic acid, was reduced by the presence of lauric acid, and was not significantly affected by palmitic acid. Liposcelis bostrychophila is the only insect for which fatty acid amides have been identified as cuticular components. Stearamide, its major fatty amide, did not reduce germination of B. bassiana or M. anisopliae conidia or growth of their mycelia. Adhesion of conidia to stearamide preparations did not differ significantly from adhesion to the cuticle of L. bostrychophila. Pretreatment of a beetle known to be fungus-susceptible, larval Oryzaephilus surinamensis, with stearamide significantly decreased adhesion of B. bassiana or M. anisopliae conidia to their cuticles. This evidence indicates that cuticular fatty amides may contribute to L. bostrychophila's tolerance for entomopathogenic fungi by decreasing hydrophobicity and static charge, thereby reducing conidial adhesion.

  15. Interactions of Chemical Additives, pH, and Temperature on Conidia Germination and Virulence of Colletotrichum truncatum, a Bioherbicide of Sesbania exaltata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied several factors that influence conidial germination and pathogenicity of the fungus Colletotrichum truncatum, which is a potential bioherbicide for hemp sesbania. The conidia germinated on 2% water agar over the pH range of 3.5 to 9.0, and the optimal pH for germination depended upon the ...

  16. Use of a granular bioplastic formulation for carrying conidia of a non-aflatoxigenic strain of Aspergillus flavus.

    PubMed

    Accinelli, Cesare; Saccà, M Ludovica; Abbas, Hamed K; Zablotowicz, Robert M; Wilkinson, Jeffery R

    2009-09-01

    Previous research demonstrated that aflatoxin contamination in corn is reduced by field application of wheat grains pre-inoculated with the non-aflatoxigenic Aspergillus flavus strain NRRL 30797. To facilitate field applications of this biocontrol isolate, a series of laboratory studies were conducted on the reliability and efficiency of replacing wheat grains with the novel bioplastic formulation Mater-Bi to serve as a carrier matrix to formulate this fungus. Mater-Bi granules were inoculated with a conidial suspension of NRRL 30797 to achieve a final cell density of approximately log 7 conidia/granule. Incubation of 20-g soil samples receiving a single Mater-Bi granule for 60-days resulted in log 4.2-5.3 propagules of A. flavus/g soil in microbiologically active and sterilized soil, respectively. Increasing the number of granules had no effect on the degree of soil colonization by the biocontrol fungus. In addition to the maintenance of rapid vegetative growth and colonization of soil samples, the bioplastic formulation was highly stable, indicating that Mater-Bi is a suitable substitute for biocontrol applications of A. flavus NRRL 30797.

  17. Aspergillus flavus Conidia-derived Carbon/Sulfur Composite as a Cathode Material for High Performance Lithium–Sulfur Battery

    NASA Astrophysics Data System (ADS)

    Xu, Maowen; Jia, Min; Mao, Cuiping; Liu, Sangui; Bao, Shujuan; Jiang, Jian; Liu, Yang; Lu, Zhisong

    2016-01-01

    A novel approach was developed to prepare porous carbon materials with an extremely high surface area of 2459.6 m2g‑1 by using Aspergillus flavus conidia as precursors. The porous carbon serves as a superior cathode material to anchor sulfur due to its uniform and tortuous morphology, enabling high capacity and good cycle lifetime in lithium sulfur-batteries. Under a current rate of 0.2 C, the carbon-sulfur composites with 56.7 wt% sulfur loading deliver an initial capacity of 1625 mAh g‑1, which is almost equal to the theoretical capacity of sulfur. The good performance may be ascribed to excellent electronic networks constructed by the high-surface-area carbon species. Moreover, the semi-closed architecture of derived carbons can effectively retard the polysulfides dissolution during charge/discharge, resulting in a capacity of 940 mAh g‑1 after 120 charge/discharge cycles.

  18. Evaluation of Conidia-Dust Formulation of the Entomopathogenic Fungus, Metarhizium anisopliae to Biocontrol the Brown-Banded Cockroach, Supella longipalpa F.

    PubMed Central

    Sharififard, Mona; Mossadegh, Mohammad Saeed; Vazirianzadeh, Babak; Latifi, Seyed Mahmood

    2014-01-01

    Background: The brown-banded cockroach Supella longipalpa (F.) as a mechanical vector of pathogens and source of allergens has recently become widespread in the city of Ahvaz, southwestern Iran. Objectives: This research was done to evaluate the efficacy of a dust-formulation of Metarhizium anisopliae isolate IRAN 437C, as a common entomopathogenous fungus, against S. longipalpa. Materials and Methods: Conidia dust-formulations of M. anisopliae were prepared in proportions of 1%, 5%, 10%, 25%, 50% and 100% with bad wheat flour as the carrier. Cockroaches were exposed to surfaces treated with 1.5 mg/cm2 of the formulations under laboratory and semi-field conditions. Results: Cockroach mortality rates increased and survival times (ST50) decreased with an increased proportion of conidia from 1% to 100% but records taken for mortality and survival time from proportions of 25%, 50% and 100% were not significantly different. The mortality rates reached 100% and 90-100% in adults and nymphs, respectively on the seventh day. The lowest ST50 was related to the proportion of 100% (3 days). Probit analysis indicated LD50 and LD90 values of 1.7 × 106 and 1.7 × 107 conidia/cm2 for adults and these values changed to 4.5 × 106 and 2.9 × 107 for third and fourth instar nymphs at three days post exposure. Proportion of 25% caused mortality rates of 87%, 81% and 73% in adult, adult & nymph and nymph populations, respectively at four days after exposure under room conditions. Conclusions: Conidia dust-formulation of M. anospliae isolate IRAN 437C could present a promising alternative to control the brown-banded cockroach. PMID:25371804

  19. Repellent activity of desiccant dusts and conidia of the entomopathogenic fungus Beauveria bassiana when tested against poultry red mites (Dermanyssus gallinae) in laboratory experiments.

    PubMed

    Kilpinen, Ole; Steenberg, Tove

    2016-11-01

    Desiccant dusts and entomopathogenic fungi have previously been found to hold potential against the poultry red mite, which is an important pest in egg production and notoriously difficult to control. Both control agents may cause repellence in other arthropods and potentially also influence control levels adversely when used against the poultry red mite. Five desiccant dust products with good efficacy against the poultry red mite Dermanyssus gallinae caused avoidance behavior in mites when tested in bioassays. The repellent activity was correlated with efficacy, which was found to depend on both dose and relative humidity (RH). However, one desiccant dust was significantly less repellent compared to other dusts with similar levels of efficacy. Further, dry conidia of the fungus Beauveria bassiana were also shown to be repellent to poultry red mites, both when applied on its own and when admixed with a low dose of the desiccant dust Diamol. The pick-up of desiccant dust particles and fungus conidia from treated surfaces by mites did not differ depending on RH, whereas the overall efficacy of the two control agents were significantly higher at 75 than at 85 % RH. In addition, the combined effect of the two substances was synergistic when tested in a bioassay where mites could choose whether to cross a treated surface. This is the first time a member of Acari has been shown to be repelled by desiccant dusts and by conidia of an entomopathogenic fungus.

  20. Modelling the effect of temperature, pH, water activity, and organic acids on the germination time of Penicillium camemberti and Penicillium roqueforti conidia.

    PubMed

    Kalai, Safaa; Anzala, Lexane; Bensoussan, Maurice; Dantigny, Philippe

    2017-01-02

    In this study, the influence of environmental factors on the germination time of Penicillium camemberti and Penicillium roqueforti conidia was evaluated. To do so, the effects of i/temperature, pH, water activity, and ii/organic acids were determined using models based on i/cardinal values, and ii/minimum inhibitory concentration (MIC) respectively. Cardinal values for germination of conidia were not observed to be species dependent. Minimum temperatures were estimated to be below the freezing point, with an optimum of 26.9°C, and a maximum of 33.5°C. For both species, minimal and optimal aw values were found to be 0.83 and 0.99, respectively, while for pH these values corresponded to 2.9, and 5.6. MIC values could not be determined for lactic acid because conidia of both species germinated in up to 1M concentrations, the highest concentration tested. At pH5.6, P. camemberti (MIC=0.197M) was more sensitive to propionic acid than P. roqueforti (MIC=0.796M).

  1. The physiological effects of multi-walled carbon nanotubes (MWCNTs) on conidia and the development of the entomopathogenic fungus, Metarhizium anisopliae (Metsch.) Sorok.

    PubMed

    Gorczyca, Anna; Kasprowicz, Marek J; Lemek, Tadeusz

    2014-01-01

    The aim of the study was an in vitro evaluation of the effect of MWCNTs on the conidia of two strains of entomopathogenic fungus, Metarhizium anisopliae. The study made use of water suspensions of MWCNTs (concentration ∼ 3 mg·mL(-1)) made from commercial nanotubes and centrifuged. The conidia were placed in contact with nanotubes for 240 h. An assessment of MWCNT influence on conidia was performed after 1, 24, 72 and 240 h and focused on the linear growth of vegetative mycelium derived from these conidia, mycelium sporulation in subcultures and pathogenicity. Using TEM imaging, it was demonstrated that carbon nanotubes are able to damage cell membranes of the examined fungi conidia. However, the absence was noted of a significantly fungistatic effect of both MWCNT suspensions on the examined strains with respect to the physiological features in question. The increase in vegetative mycelium effected by spores after contact with MWCNTs was characterized by a slight modification in relation to the control. There was no strong trend (inhibition - stimulation), in relation to the effect of the tested suspension of carbon nanotubes, on the development of the vegetative mycelium in in vitro culture. Sporulation of the mycelium after completion of the culture only occurred in one case (strain Ma73F and culture of spores after 24-h contact with MWCNTs) significantly more intensely than in the controls. With respect to pathogenicity for test insects compared to the control strain, Ma73F spores grown from the longest contact with nanotubes suspensions performed significantly better. On the basis of the calculated of mycelium index growth rates and the time of death of the test insects (LT50), it was found that the adverse effects of water suspension MWCNTs on the spores of M. anisopliae were applied after a short contact with biological material. This indicates unfavorable physical rather than chemical effects on the tested cell. Over time, nanotube aggregation in water

  2. Effects of Airflow and Changing Humidity on the Aerosolization of Respirable Fungal Fragments and Conidia of Botrytis cinerea

    PubMed Central

    2012-01-01

    The purpose of this study was to investigate the aerosolization of particles (micro- and macroconidia and fragments) from Botrytis cinerea cultures in relation to potential human inhalation in indoor environments. The influence of the following factors on the aerosolization of B. cinerea particles was studied: exposure to airflow, relative humidity (rh), changing rh, and plant or building materials. The aerodynamic diameter (da) and the respirable fraction of the aerosolized particles were determined. Conidia and fragments of B. cinerea were not aerosolized as a response to a decrease in the rh. In contrast, both micro- and macroconidia and fungal fragments were aerosolized when exposed to an airflow of 1.5 m s−1 or 0.5 m s−1. Significantly more particles of microconidial size and fragment size were aerosolized at a low rh (18 to 40% rh) than at a higher rh (60 to 80% rh) when cultures were exposed to airflow. The size of the respirable fraction of the aerosolized particles was dependent on the rh but not on the growth material. At high rh, about 30% of the aerosolized particles were of respirable size, while at low rh, about 70% were of respirable size. During low rh, more fungal (1→3)-β-d-glucan and chitinase were aerosolized than during high rh. In conclusion, exposure to external physical forces such as airflow is necessary for the aerosolization of particles from B. cinerea. The amount and size distribution are highly affected by the rh, and more particles of respirable sizes were aerosolized at low rh than at high rh. PMID:22447608

  3. Survival of Penicillium spp. conidia during deep-frying and baking steps of frozen chicken nuggets processing.

    PubMed

    Wigmann, Évelin Francine; Moreira, Rafael Chelala; Alvarenga, Verônica Ortiz; Sant'Ana, Anderson S; Copetti, Marina Venturini

    2016-05-01

    This study aimed at determining whether Penicillium spp. strains could survive through the heat treatment applied during the processing of frozen chicken nuggets. Firstly, it was found that the conidia of Penicillium were not able to survive the heat shock in phosphate buffer at pH 7.2 in thermal death tubes (TDT) at 80 °C/30 min. Subsequently, each Penicillium strain was inoculated in frozen chicken nuggets, which were subjected to the following treatments: i) only deep frying (frying oil at 195-200 °C), ii) only baking (120-130 °C until the internal temperature reached 70 °C) and iii) deep frying followed by baking (frying oil temperature of 195-200 °C and baking temperature of 120-130 °C, until the internal temperature reached 70 °C). The results indicated that Penicillium polonicum NGT 23/12, Penicillium commune NGT 16/12, Penicillium solitum NGT 30/12 and Penicillium crustosum NGT 51/12 were able to survive after the combined treatment (deep frying followed by baking) when inoculated in chicken nuggets. P. polonicum NGT 23/12 was the most resistant strain to the combined treatment (deep frying and baking), as its population was reduced by 3 log cycles CFU/g, when the internal temperature reached 78 °C after 10 min and 30 s of baking. The present data show that if Penicillium spp. is present in high numbers in raw materials, such as breading flours, it will survive the thermal processing applied during chicken nuggets production.

  4. Increased rDNA synthesis in germinated conidia of Neurospora crassa is caused by RNA primer molecules found in its culture medium

    SciTech Connect

    Dutta, S.K.; Beljanski, M.

    1984-01-01

    Purine rich small primer RNA molecules (10-15 nucleotides) were isolated from growth medium of germinated (3 hr sprout) conidia of N. crassa. These RNA-primer molecules strongly stimulated in vitro DNA synthesis in N. crassa 74A wild type, as well as in DNAs from mice spleen and lung, and quail testis. These increases of in vitro DNA synthesis was dependent on the concentration of these RNA primer molecules. In contrast, such molecules were not found in 1 or 10 hour sprouts, nor in the culture medium of mycelia (24 hr). These RNA-primer molecules could be hydrolyzed by T1 RNAse but not by pancreatic RNase. Dutta et al. reported increased (250) copies of rRNA genes in germinated conidia (3 hr sprouts) compared to 100 copies of rRNA genes in mycelial cells grown for 24 hours. These observations suggest excessive transcription of rDNAs in the germinated conidial cells which undergo cleavages by nucleates after 3-4 hours of cell growth. Some degradation products were excreted into the culture medium and acted as RNA-primers.

  5. Environmental Scanning Electron Microscopy characterization of the adhesion of conidia from Penicillium expansum to cedar wood substrata at different pH values.

    PubMed

    El Abed, Soumya; Ibnsouda, Saad Koraichi; Latrache, Hassan; Meftah, Hasna; Tahri, Nezha Joutey; Hamadi, Fatima

    2012-04-01

    Initial microbial adhesion to surfaces is a complicated process that is affected by a number of factors. An important property of a solution that may influence adhesion is pH. The surface properties of the cedar wood were characterized by the sessile drop technique. Moreover, the interfacial free energy of surface adhesion to the cedar wood was determined under pH values (2, 3, 5, 7, 9 and 11). The results showed that cedar wood examined at different pH levels could be considered hydrophobic ranged from Giwi = -13.1 mJ/m(2) to Giwi = -75 mJ/m(2). We noted that the electron-donor character of cedar wood was important at both basic and limit acidic conditions (pH 11 and pH 3) and it decreased at intermediate pH (pH 5). The cedar wood substratum presents a weak electron acceptor under various pH's. In addition, the adhesion of conidia from Penicilllium expansum to the cedar wood surfaces at different pH values (2, 3, 5, 7, 9 and 11) was investigated using Environmental Scanning Electron Microscopy and image analysis was assessed with the Mathlab(®) program. The data analysis showed that the conidia from P. expansum were strongly influenced by the pH. The maximum adhesion occurs in the pH 11 and pH 3 and decreased to 24% at pH 5.

  6. Liquid culture production of microsclerotia and submerged conidia by Trichoderma harzianum active against damping-off disease caused by Rhizoctonia solani.

    PubMed

    Kobori, Nilce N; Mascarin, Gabriel M; Jackson, Mark A; Schisler, David A

    2015-04-01

    Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L(-1)) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (<4% moisture) retained excellent shelf life under cool and unrefrigerated storage conditions with no loss in conidial production. A low-cost complex nitrogen source based on cottonseed flour effectively supported high MS yields. Amending potting mix with dried MS formulations reduced or eliminated damping-off of melon seedlings caused by Rhizoctonia solani. Together, the results provide insights into the liquid culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases.

  7. New collection of Acrogenospora spharerocephala from freshwater habitats of Northern Thailand

    NASA Astrophysics Data System (ADS)

    Liu, X. J.; Li, F. P.; Liu, W.; Huang, X. L.; Zhang, H.

    2017-01-01

    During investigations of freshwater fungi in Thailand, we collected dematiaceous hyphomycetes Acrogenospora spharerocephalan in lotic freshwater habitat. The description and morphological photographs of new collection is illustrated. Acrogenospora spharerocephala was characterized by unbranched conidiophores and producing solitary non-septate conidia acrogenously from recurrently proliferating conidiogenous cells. The conidia are dark brown to black when mature, paler at young, spherical to subspherical.

  8. Inhibition of spoilage mould conidia by acetic acid and sorbic acid involves different modes of action, requiring modification of the classical weak-acid theory.

    PubMed

    Stratford, Malcolm; Plumridge, Andrew; Nebe-von-Caron, Gerhardt; Archer, David B

    2009-11-30

    Fungal spoilage of many foods is prevented by weak-acid preservatives such as sorbic acid or acetic acid. We show that sorbic and acetic acids do not both inhibit cells by lowering of internal pH alone and that the "classical weak-acid theory" must be revised. The "classical weak-acid theory" suggests that all lipophilic acids with identical pK(a) values are equally effective as preservatives, causing inhibition by diffusion of molecular acids into the cell, dissociation, and subsequent acidification of the cytoplasm. Using a number of spoilage fungi from different genera, we have shown that sorbic acid was far more toxic than acetic acid, and no correlation existed between resistance to acetic acid and resistance to sorbic acid. The molar ratio of minimum inhibitory concentrations (MICs) (acetic: sorbic) was 58 for Paecilomyces variotii and 14 for Aspergillus phoenicis. Using flow cytometry on germinating conidia of Aspergillusniger, acetic acid at pH 4.0 caused an immediate decline in the mean cytoplasmic pH (pH(i)) falling from neutrality to approximately pH 4.7 at the MIC (80 mM). Sorbic acid also caused a rapid but far smaller drop in pH(i), at the MIC (4.5 mM); the pH remained above pH 6.3. Over 0-5 mM, a number of other weak acids caused a similar fall in cytoplasmic pH. It was concluded that while acetic acid inhibition of A. niger conidia was due to cytoplasmic acidification, inhibition by sorbic acid was not. A possible membrane-mediated mode of action of sorbic acid is discussed.

  9. Role of ozone in UV-C disinfection, demonstrated by comparison between wild-type and mutant conidia of Aspergillus niger.

    PubMed

    Liu, Jing; Zhou, Lin; Chen, Ji-Hong; Mao, Wang; Li, Wen-Jian; Hu, Wei; Wang, Shu-Yang; Wang, Chun-Ming

    2014-01-01

    This study aimed to investigate the tolerance of a melanized wild-type strain of Aspergillus niger (CON1) and its light-colored mutant (MUT1) to UV-C light and the concomitantly generated ozone. Treatments were segregated into four groups based on whether UV irradiation was used and the presence or absence of ozone: (-UV, -O3), (-UV, +O3), (+UV, -O3) and (+UV, +O3). The survival of CON1 and MUT1 conidia under +UV decreased as the exposure time increased, with CON1 showing greater resistance to UV irradiation than MUT1. Ozone induced CON1 conidium inactivation only under conditions of UV radiation exposure. While, the inactivation effect of ozone on MUT1 was always detectable regardless of the presence of UV irradiation. Furthermore, the CON1 conidial suspension showed lower UV light transmission than MUT1 when examined at the same concentration. Compared with the pigment in MUT1, the melanin in CON1 exhibited more potent radical-scavenging activity and stronger UV absorbance. These results suggested that melanin protected A. niger against UV disinfection via UV screening and free radical scavenging. The process by which UV-C disinfection induces a continual decrease in conidial survival suggests that UV irradiation and ozone exert a synergistic fungicidal effect on A. niger prior to reaching a plateau.

  10. Visual expression analysis of the responses of the alternative oxidase gene (aox1) to heat shock, oxidative, and osmotic stresses in conidia of citric acid-producing Aspergillus niger.

    PubMed

    Honda, Yuki; Hattori, Takasumi; Kirimura, Kohtaro

    2012-03-01

    The citric acid-producing filamentous fungus Aspergillus niger WU-2223L shows cyanide-insensitive respiration catalyzed by alternative oxidase in addition to the cytochrome pathway. Sequence analysis of the 5' flanking region of the alternative oxidase gene (aox1) revealed a potential heat shock element (HSE) and a stress response element (STRE). We have previously confirmed aox1 expression in conidia. In this study, to confirm whether the upstream region of aox1 responds to various stresses, we used a visual expression analysis system for single-cell conidia of the A. niger strain AOXEGFP-1. This strain harbored a fusion gene comprising aox1 and egfp, which encodes the enhanced green fluorescent protein (EGFP). The fluorescence intensity of EGFP increased in conidia of A. niger AOXEGFP-1 that were subjected to heat shock at 35-45 °C, oxidative stress by exposure to 5mM paraquat or 1 mM t-butylhydroperoxide, or osmotic stresses by exposure to 0.5 M KCl or 1.0 M mannitol. These results indicate that the putative HSE and STRE in the upstream region of aox1 directly or indirectly respond to heat shock, oxidative, and osmotic stresses.

  11. Effects of tricyclazole (5-methyl-1,2,4-triazol[3,4] benzothiazole), a specific DHN-melanin inhibitor, on the morphology of Fonsecaea pedrosoi conidia and sclerotic cells.

    PubMed

    Franzen, Anderson J; Cunha, Marcel M L; Batista, Evander J O; Seabra, Sergio H; De Souza, Wanderley; Rozental, Sonia

    2006-09-01

    The influence of tricyclazole (5-methyl-1,2,4-triazol[3,4]benzothiazole), a specific DHN-melanin inhibitor, on the cell walls and intracellular structures of Fonsecaea pedrosoi conidia and sclerotic cells was analyzed by transmission electron microscopy (TEM), deep-etching, and field emission scanning electron microscopy. The treatment of the fungus with 16 microg mL(-1) of tricyclazole (TC) did not significantly affect fungal viability, but electron microscopy observations showed several important morphological differences between TC-treated and non-TC treated cells. Control sclerotic cells presented patched granules, with an average diameter of 47 nm, on the cell surface, which were absent in TC-treated cells. Also, TC-treated sclerotic cells showed an undulated relief. TC treatment leads to an accumulation of electron lucent vacuoles in the fungal cytoplasm of both conidia and sclerotic cells, and treated conidia observed by deep etching showed a relevant thickening of the fungal cell wall. Together, these observations support the previous data of our group that F. pedrosoi synthesizes melanin in intracellular organelles. In addition, we suggest that melanin is not only an extracellular constituent but could also be dispersing all over the cell walls and could have an effective role in cross-linking different cell wall compounds that help maintain the regular shape of the cell wall.

  12. The pmr gene, encoding a Ca2+-ATPase, is required for calcium and manganese homeostasis and normal development of hyphae and conidia in Neurospora crassa.

    PubMed

    Bowman, Barry J; Abreu, Stephen; Johl, Jessica K; Bowman, Emma Jean

    2012-11-01

    The pmr gene is predicted to encode a Ca(2+)-ATPase in the secretory pathway. We examined two strains of Neurospora crassa that lacked PMR: the Δpmr strain, in which pmr was completely deleted, and pmr(RIP), in which the gene was extensively mutated. Both strains had identical, complex phenotypes. Compared to the wild type, these strains required high concentrations of calcium or manganese for optimal growth and had highly branched, slow-growing hyphae. They conidiated poorly, and the shape and size of the conidia were abnormal. Calcium accumulated in the Δpmr strains to only 20% of the wild-type level. High concentrations of MnCl(2) (1 to 5 mM) in growth medium partially suppressed the morphological defects but did not alter the defect in calcium accumulation. The Δpmr Δnca-2 double mutant (nca-2 encodes a Ca(2+)-ATPase in the plasma membrane) accumulated 8-fold more calcium than the wild type, and the morphology of the hyphae was more similar to that of wild-type hyphae. Previous experiments failed to show a function for nca-1, which encodes a SERCA-type Ca(2+)-ATPase in the endoplasmic reticulum (B. J. Bowman, S. Abreu, E. Margolles-Clark, M. Draskovic, and E. J. Bowman, Eukaryot. Cell 10:654-661, 2011). The pmr(RIP) Δnca-1 double mutant accumulated small amounts of calcium, like the Δpmr strain, but exhibited even more extreme morphological defects. Thus, PMR can apparently replace NCA-1 in the endoplasmic reticulum, but NCA-1 cannot replace PMR. The morphological defects in the Δpmr strain are likely caused, in part, by insufficient concentrations of calcium and manganese in the Golgi compartment; however, PMR is also needed to accumulate normal levels of calcium in the whole cell.

  13. Characterization of NpgA, a 4'-phosphopantetheinyl transferase of Aspergillus nidulans, and evidence of its involvement in fungal growth and formation of conidia and cleistothecia for development.

    PubMed

    Kim, Jung-Mi; Song, Ha-Yeon; Choi, Hyo-Jin; So, Kum-Kang; Kim, Dae-Hyuk; Chae, Keon-Sang; Han, Dong-Min; Jahng, Kwang-Yeop

    2015-01-01

    The null pigmentation mutant (npgA1) in Aspergillus nidulans results in a phenotype with colorless organs, decreased branching growth, delayed of asexual spore development, and aberrant cell wall structure. The npgA gene was isolated from A. nidulans to investigate these pleiomorphic phenomena of npgA1 mutant. Sequencing analysis of the complementing gene indicated that it contained a 4'-phosphopantetheinyl transferase (PPTase) superfamily domain. Enzymatic assay of the PPTase, encoded by the npgA gene, was implemented in vivo and in vitro. Loss-of-function of LYS5, which encoded a PPTase in Saccharomyces cerevisiae, was functionally complemented by NpgA, and Escherichia coli-derived NpgA revealed phosphopantetheinylation activity with the elaboration of 3'5'-ADP. Deletion of the npgA gene caused perfectly a lethal phenotype and the absence of asexual/sexual sporulation and secondary metabolites such as pigments in A. nidulans. However, a cross feeding effect with A. nidulans wild type allowed recovery from deletion defects, and phased-culture filtrate from the wild type were used to verify that the npgA gene was essential for formation of metabolites needed for development as well as growth. In addition, forced expression of npgA promoted the formation of conidia and cleistothecia as well as growth. These results indicate that the npgA gene is involved in the phosphopantetheinylation required for primary biological processes such as growth, asexual/sexual development, and the synthesis of secondary metabolites in A. nidulans.

  14. Proteomic analysis of conidia germination in Fusarium oxysporum f. sp. cubense tropical race 4 reveals new targets in ergosterol biosynthesis pathway for controlling Fusarium wilt of banana.

    PubMed

    Deng, Gui-Ming; Yang, Qiao-Song; He, Wei-Di; Li, Chun-Yu; Yang, Jing; Zuo, Cun-Wu; Gao, Jie; Sheng, Ou; Lu, Shao-Yun; Zhang, Sheng; Yi, Gan-Jun

    2015-09-01

    Conidial germination is a crucial step of the soilborne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), a most important lethal disease of banana. In this study, a total of 3659 proteins were identified by isobaric tags for relative and absolute quantitation (iTRAQ)-based comparative proteomic approach, of which 1009 were differentially expressed during conidial germination of the fungus at 0, 3, 7, and 11 h. Functional classification and bioinformatics analysis revealed that the majority of the differentially expressed proteins are involved in six metabolic pathways. Particularly, all differential proteins involved in the ergosterol biosynthesis pathway were significantly upregulated, indicating the importance of the ergosterol biosynthesis pathway to the conidial germination of Foc TR4. Quantitative RT-PCR, western blotting, and in vitro growth inhibition assay by several categories of fungicides on the Foc TR4 were used to validate the proteomics results. Four enzymes, C-24 sterol methyltransferase (ERG6), cytochrome P450 lanosterol C-14α-demethylase (EGR11), hydroxymethylglutaryl-CoA synthase (ERG13), and C-4 sterol methyl oxidase (ERG25), in the ergosterol biosynthesis pathway were identified and verified, and they hold great promise as new targets for effective inhibition of Foc TR4 early growth in controlling Fusarium wilt of banana. To the best of our knowledge, this report represents the first comprehensive study on proteomics profiling of conidia germination in Foc TR4. It provides new insights into a better understanding of the developmental processes of Foc TR4 spores. More importantly, by host plant-induced gene silencing (HIGS) technology, the new targets reported in this work allow us to develop novel transgenic banana leading to high protection from Fusarium wilt and to explore more effective antifungal drugs against either individual or multiple target proteins of Foc TR4.

  15. Nomenclatural notes on some cercosporoid hyphomycetes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cercospora haleniae is validated, Cercospora tragiicola sp. nov. and Passalora halesiicola sp. nov. (Cercospora halesiae nom. inval., Passalora halesiae comb. inval.) are described and the combination Pseudocercospora nepheloides is introduced....

  16. Influence of plant root exudates, germ tube orientation and passive conidia transport on biological control of fusarium wilt by strains of nonpathogenic Fusarium oxysporum.

    PubMed

    Mandeel, Qaher A

    2006-03-01

    reached at 96 h. The presented data confirm the previous findings that attributes important for nonpathogenic fusaria to induce resistant are: rapid spore germination and orientation in response to root exudate; active root penetration and passive conidia transport in stem to initiate defence reaction without pathogenicity and enough lag period between induction and challenge inoculation. Strain C14 possesses all these qualifications and hence its ability to enhance host resistance is superior than strain C5.

  17. Formation of 1-octen-3-ol from Aspergillus flavus conidia is accelerated after disruption of cells independently of Ppo oxygenases, and is not a main cause of inhibition of germination.

    PubMed

    Miyamoto, Kana; Murakami, Tomoko; Kakumyan, Pattana; Keller, Nancy P; Matsui, Kenji

    2014-01-01

    Eight-carbon (C8) volatiles, such as 1-octen-3-ol, are ubiquitous among fungi. They are the volatiles critical for aroma and flavor of fungi, and assumed to be signals controlling germination of several fungi. In this study, we found that intact Aspergillus flavus conidia scarcely synthesized C8 volatiles but repeated freeze-thaw treatment that made the cell membrane permeable promoted (R)-1-octen-3-ol formation. Loss or down regulation of any one of five fatty acid oxygenases (PpoA, PpoB, PpoC, PpoD or lipoxygenase) hypothesized contribute to 1-octen-3-ol formation had little impact on production of this volatile. This suggested that none of the oxygenases were directly involved in the formation of 1-octen-3-ol or that compensatory pathways exist in the fungus. Germination of the conidia was markedly inhibited at high density (1.0 × 10(9)spores mL(-1)). It has been postulated that 1-octen-3-ol is an autoinhibitor suppressing conidia germination at high density. 1-Octen-3-ol at concentration of no less than 10 mM was needed to suppress the germination while the concentration of 1-octen-3-ol in the suspension at 1.0 × 10(9) mL(-1) was under the detection limit (<1 µM). Thus, 1-octen-3-ol was not the principal component responsible for inhibition of germination. Instead, it was evident that the other heat-labile factor(s) suppressed conidial germination.

  18. Species and ecological diversity within the Cladosporium cladosporioides complex (Davidiellaceae, Capnodiales)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Cladosporium is one of the largest genera of dematiaceous hyphomycetes, and is characterised by a coronate scar structure, conidia in acropetal chains and Davidiella teleomorphs. Based on morphology and DNA phylogeny, the species complexes of C. herbarum and C. sphaerospermum have been res...

  19. John Webster: a personal perspective.

    PubMed

    Fisher, Peter J

    2005-05-01

    A personal perspective of John Webster, with an emphasis of studies of aero-aquatic hyphomycetes and the techniques pioneered to enable them to be studied, illustrated by examples particularly from the genera with helicoid conidia, Helicodendron and Helicoon, showing flotation devices.

  20. SPM and fungal spores in the ambient air of west Korea during the Asian dust (Yellow sand) period

    NASA Astrophysics Data System (ADS)

    Yeo, Hwan-Goo; Kim, Jong-Ho

    The relationship between suspended particulate matter (SPM) and fungal spore was investigated in Seosan, a rural county along the west coast of Korea, in the spring of 2000. SPM concentrations in the air were 199.8 μg m -3 in the first Asian dust period (23-24 March), 249.4 μg m -3 in the second Asian dust period (7-9 April) and 98.9 μg m -3 in the non-Asian dust period (12-16 May), respectively. The majority of the total SPM were composed of coarse particles sized about 5 μm during the two Asian dust periods. Four molds genera grown from airborne fungal spores were identified in colonies grown from SPM samples taken during the Asian dust periods. All the genera found, Fusarium, Aspergillus, Penicillium and Basipetospora, are hyphomycetes in the division Deuteromycota. Morphologically, more diversified mycelia of hyphomycetes were grown on the sample captured from 1.1 to 2.1 μm sized SPM than on the other sized samples gathered in the dust periods. On the other hand, no mold was observed on the sample of 1.1-2.1 μm sized SPM in the non-Asian dust period. From these results, it seems evident that several sorts of fine sized fungal spores were suspended in the atmospheric environment of this study area during Asian dust periods.

  1. The impact of biotechnology on hyphomycetous fungal insect biocontrol agents.

    PubMed

    Hegedus, D D; Khachatourians, G G

    1995-01-01

    The potential for the control of insect pests by entomopathogenic fungi has been touted for decades, if not centuries. Only recently have advances in biotechnology provided the tools for indepth analysis of the mechanisms involved in pathogenesis and host death at the molecular level. This review outlines the current state of knowledge regarding the mode of infection and targets several key components that are amenable to improvement via biotechnology. Realization of the considerable economic potential of fungal bioinsecticides can occur only through a combined and coordinated effort involving fundamental science, formulation technology and field applications.

  2. Transformation of Epichloë typhina by electroporation of conidia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Choke, caused by the endophytic fungus Epichloë typhina is an important disease of orchardgrass (Dactylis glomerata L.) grown for seed. Very little is known concerning the conditions necessary for successful infection of orchardgrass by E. typhina. Detection of E. typhina early in the disease cycle ...

  3. Ramophialophora humicola and Fibulochlamys chilensis, two new microfungi from soil.

    PubMed

    Madrid, H; Cano, J; Stchigel, A; Gené, J; Guarro, J

    2010-01-01

    In a study on soil microfungi from different countries two new hyphomycetes were found. The first one, Ramophialophora humicola, isolated from a soil sample collected in Ronda (Spain), is characterized by producing profusely branched conidiophores ending in sterile, sometimes swollen apices, and subhyaline, dacryoid conidia borne from both integrated and discrete phialides with conspicuous collaretes. ITS sequence data reveal its relationships with members of the Sordariales and its genetic differences with other fungi morphologically close, such as Cladorrhinum spp. The second species, Fibulochlamys chilensis, isolated from a soil sample collected in LaJunta (Chile), is characterized by micronematous, clamped, mostly branched conidiophores producing thallic, one-celled, thick-walled conidia that exhibit strongly wrinkled surfaces in age. The analysis of partial sequences of the ITS region and 28S rRNA gene reveal that this fungus is close to members of the gilled Agaricales.

  4. The hyphomycete genus Piricauda, with the description of a new species.

    PubMed

    Mercado Sierra, Angel; Guarro, Josep; Heredia, Gabriela

    2005-06-01

    The genus Piricauda comprises eight species characterized by monotretic conidiogenous cells and micronematous arched conidiophores: P. cochinensis, P. cubensis, P. longispora, P. mexicana, P. paraguayensis, P. pseudarthriae, P. taiwanensis, and P. vulcanensis sp. nov. P. caribensis is transferred to Acrodictys. Species usually colonize dead petioles and rachides of palms in tropical and subtropical areas, but can also be found on branches and leaves of different trees. The species are illustrated and briefly described, and a key to them is provided.

  5. Carbon requirements of some nematophagous, entomopathogenic and mycoparasitic hyphomycetes as fungal biocontrol agents.

    PubMed

    Sun, ManHong; Liu, XingZhong

    2006-05-01

    Thirty-three carbon sources were evaluated for their effects on spore germination, hyphal growth and sporulation of 11 fungal biocontrol agents, i.e. the nematophagous fungi Paecilomyces lilacinus, Pochonia chlamydosporia, Hirsutella rhossiliensis, H. minnesotensis and Arkansas Fungus 18, the entomopathogenic fungi Lecanicillium lecanii, Beauveria bassiana and Metarhizium anisopliae, and the mycoparasitic fungus Trichoderma viride. Variations in carbon requirements were found among the fungal species or strains tested. All strains studied except for T. viride grew on most carbon sources, although B. bassiana had more fastidious requirements for spore germination. Monosaccharides and disaccharides were suitable for fungal growth. For most isolates, D-glucose, D-mannose, sucrose and trehalose were superior to pectin and soluble starch among the polysaccharides and lactic acid among the organic acids. Both ethanol and methanol could accelerate growth of most isolates but not biomass. D-mannose, D-fructose and D-xylose were excellent carbon sources for sporulation, while D-glucose, sucrose, cellobiose, trehalose, chitin, dextrin, gelatin and lactic acid were better for some isolates. Neither sorbic acid nor linoleic acid could be utilized as a single carbon source. These findings provided a better understanding of the nutritional requirements of different fungal biocontrol agents that can benefit the mass production process.

  6. Virulence of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes) on Anastrepha ludens (Diptera: Tephritidae): laboratory and field trials.

    PubMed

    Lezama-Gutiérrez, R; Trujillo-de la Luz, A; Molina-Ochoa, J; Rebolledo-Dominguez, O; Pescador, A R; López-Edwards, M; Aluja, M

    2000-08-01

    Twenty isolates of the fungus Metarhizium anisopliae (Metsch). Sorkin (Ma) were evaluated to determine their virulence against last instar and adult emergence of Mexican fruit fly, Anastrepha ludens (Loew). Larvae were exposed by immersion in a conidial suspension at a concentration of 10(8) UFC/ml under laboratory conditions. Larvae and pupae cumulative mortality rates ranged from 37.9 to 98.75%. Thirteen isolates caused mortality rates > 83.7%, and their LT50 values ranged from 1.8 to 6.2 d. The Ma2, Ma8, and Ma16 isolates were evaluated at seven different concentrations ranging from 10(1) to 10(7) UFC/ml, showing LC50 values from 3.7 to 4.8 x 10(5) UFC/ml. In a field-cage experiment, 200 ml of a conidial suspension of Ma2, at a concentration of 2.5 x 10(6) UFC/ml, was applied on 2,500 cm2 soil surface (2 x 10(5) UFC/cm2). The fungus reduced adult emergence, 22% fewer adults emerging in a sandy loam soil, and 43% fewer in loam soil, compared with the controls. M. anisopliae may offer a preferable alternative to chemicals as a biological control agent against A. ludens.

  7. Preillumination of rice blast conidia induces tolerance to subsequent oxidative stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many environmental factors, alone or combined, affect organisms by changing a pro-/antioxidant balance. Here we tested rice blast fungus (Magnaporthe oryzae) for possible cross-adaptations caused by relatively intense light and protecting from artificially formed reactive oxygen species (ROS) and RO...

  8. Inactivation of conidia of Penicillium chrysogenum, P. digitatum and P. italicum by ethanol solutions and vapours.

    PubMed

    Dao, Thien; Bensoussan, Maurice; Gervais, Patrick; Dantigny, Philippe

    2008-02-29

    A fractional factorial design, 2(5-1) experiments, was used for assessing the influence of 5 factors: water activity, aw [0.7, 0.9], temperature, T ( degrees C) [10, 30], mode of application, A [liquid, vapour], ethanol concentration, E (% w/w) [5, 10] and time, t (d) [1, 4] on the inactivation of spores of Penicillium chrysogenum, P. digitatum and P. italicum. Survival was determined by germination at optimal conditions within 3d. The experimental response was log (N 0/Nt), where N 0 and Nt (spore ml(-1)) the concentrations of viable spores at t=0 and t respectively. By a decreasing order of sensitivity to ethanol, moulds were ranked as followed: P. digitatum, P. italicum and P. chrysogenum. A greater inactivation for P. digitatum, P. italicum, that were the most sensitive moulds to ethanol, was obtained by applying vapour rather than ethanol solution. The order of significance of the main factors depended upon the mould. The key factor for explaining inactivation of P. chrysogenum was water activity. But, temperature was the main factor for explaining inactivation of P. digitatum and P. italicum. In the more drastic conditions, (i.e., 0.7 aw, 30 degrees C, 10% w/w ethanol), all spores were inactivated by applying liquid solution for 4d.

  9. Imbibitional damage in conidia of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Metarhizium acridum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When dried organisms are immersed in water, rapid imbibition may cause severe damage to plasma membranes; in unicellular organisms, such damage is usually lethal. This study investigated effects of pre-immersion moisture levels and immersion temperature on imbibitional damage in three insect pathoge...

  10. Effect of storage temperature and sphacellum age on C. africana conidia survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum ergot, caused by Claviceps africana Frederickson, Mantle & de Milliano, is a disease that poses a serious treat to sorghum, especially in hybrid seed production. The initial sign of the disease is called a sphacelium. Sphacelia containing macroconidia could play a role in the survival of t...

  11. Confirming resistance in bottle gourd germplasm by quantifying powdery mildew conidia using a cellometer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew (PM) caused by Podosphaera xanthii, an important foliar disease affecting cucurbit crops grown in the United States, commonly occurs on foliage, petioles, and stems. We have developed two highly resistant bottle gourd (Lagenaria siceraria) germplasm (USVL351 and USVL482) for use in o...

  12. Storage conditions affect speed of germination in Beauveria bassiana and Metarhizium anisopliae conidia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The retention of high viability during storage is essential for effectiveness and thus market acceptance of fungus-based biopesticides. The length of adequate shelf-lives for mycoinsecticides is controversial, with proposed requirements varying from a few weeks to 18 months. Shelf-life determination...

  13. Shelf-life of Beauveria bassiana conidia in gaseous atmospheres under high temperature regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The retention of high viability during storage is essential for effectiveness and thus market acceptance of fungus-based biopesticides. The length of adequate shelf-lives for mycoinsecticides is controversial, with proposed requirements varying from a few weeks to 18 months. Shelf-life determination...

  14. [Aerobiological study of Alternaria and Cladosporium conidia in the atmosphere of Almeria (SE Spain)].

    PubMed

    Sabariego Ruiz, Silvia; Díaz de la Guardia Guerrero, Consuelo; Alba Sánchez, Francisca

    2004-09-01

    This study analysed the seasonal and intradiurnal behaviour of fungal spores from Alternaria and Cladosporium on air samples collected in the city of Almeria (SE Spain), as well as the influence that meteorological parameters have on the concentration of these type of spores. Aerobiological sampling was made during four years (1998-2001) using a Hirst-type volumetric spore trap. Spores of Alternaria and Cladosporium were detected throughout the year, reaching the highest concentrations from May to October. The diurnal patterns of these taxons reflected a presence similar of spores during a 24 h period, with values horary close to 4% of total sampling daily. The correlations show a positive association with temperature, hours of sunshine and accumulate rainfall, but negative with daily rainfall.

  15. Determining Diversity of Freshwater Fungi on Decaying Leaves: Comparison of Traditional and Molecular Approaches

    PubMed Central

    Nikolcheva, Liliya G.; Cockshutt, Amanda M.; Bärlocher, Felix

    2003-01-01

    Traditional microscope-based estimates of species richness of aquatic hyphomycetes depend upon the ability of the species in the community to sporulate. Molecular techniques which detect DNA from all stages of the life cycle could potentially circumvent the problems associated with traditional methods. Leaf disks from red maple, alder, linden, beech, and oak as well as birch wood sticks were submerged in a stream in southeastern Canada for 7, 14, and 28 days. Fungal biomass, estimated by the amount of ergosterol present, increased with time on all substrates. Alder, linden, and maple leaves were colonized earlier and accumulated the highest fungal biomass. Counts and identifications of released conidia suggested that fungal species richness increased, while community evenness decreased, with time (up to 11 species on day 28). Conidia of Articulospora tetracladia dominated. Modifications of two molecular methods—denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) analysis—suggested that both species richness and community evenness decreased with time. The dominant ribotype matched that of A. tetracladia. Species richness estimates based on DGGE were consistently higher than those based on T-RFLP analysis and exceeded those based on spore identification on days 7 and 14. Since traditional and molecular techniques assess different aspects of the fungal organism, both are essential for a balanced view of fungal succession on leaves decaying in streams. PMID:12732520

  16. Pseudosigmoidea ibarakiensis sp. nov., a dark septate endophytic fungus from a cedar forest in Ibaraki, Japan.

    PubMed

    Diene, Ousmane; Wang, Wei; Narisawa, Kazuhiko

    2013-01-01

    A dark septate fungus of Pseudosigmoidea, Hyphomycetes, was recovered from forest soil in Ibaraki prefecture, Japan. The isolate is characterized by pale to brown conidia with up to 8 septa measuring 68-132 × 4-7.9 mm. It is also unique in producing conidia borne by long conidogenious cells in agar medium with or without water, compared to P. cranei, which must be immersed in water to sporulate. Morphological analysis indicated that the isolate is distinct from P. cranei and is described as a new species, P. ibarakiensis sp. nov. Pathogenicity tests of Chinese cabbage and cucumber seedlings indicated that the fungus grows as an endophyte and colonizes, inter and intracellularly, the root epidermal and cortical layers without causing apparent disease symptoms in the host. This endophyte showed the ability to support cucumber plant growth under conditions where NaNO3 was replaced by organic nitrogen but also conferred to Chinese cabbage the ability to grow at low pH. It also became successfully established in six other plants, including the Brassicae, Solanaceae, Poaceae, and Liliacea families, suggesting its adaptability to a broad range of host plants.

  17. Septoria-like pathogens causing leaf and fruit spot of pistachio.

    PubMed

    Crous, Pedro W; Quaedvlieg, William; Sarpkaya, Kamil; Can, Canan; Erkılıç, Ali

    2013-12-01

    Several species of Septoria are associated with leaf and fruit spot of pistachio (Pistacia vera), though their identity has always been confused, making identification problematic. The present study elucidates the taxonomy of the Septoria spp. associated with pistachio, and distinguishes four species associated with this host genus. Partial nucleotide sequence data for five gene loci, ITS, LSU, EF-1α, RPB2 and Btub were generated for a subset of isolates. Cylindroseptoria pistaciae, which is associated with leaf spots of Pistacia lentiscus in Spain, is characterised by pycnidial conidiomata that give rise to cylindrical, aseptate conidia. Two species of Septoria s. str. are also recognised on pistachio, S. pistaciarum, and S. pistaciae. The latter is part of the S. protearum species complex, and appears to be a wide host range pathogen occurring on hosts in several different plant families. Septoria pistacina, a major pathogen of pistachio in Turkey, is shown to belong to Pseudocercospora, and not Septoria as earlier suspected. Other than for its pycnidial conidiomata, it is a typical species of Pseudocercospora based on its smooth, pigmented conidiogenous cells and septate conidia. This phenomenon has also been observed in Pallidocercospora, and seriously questions the value of conidiomatal structure at generic level, which has traditionally been used to separate hyphomycetous from coelomycetous ascomycetes. Other than DNA barcodes to facilitate the molecular identification of these taxa occurring on pistachio, a key is also provided to distinguish species based on morphology.

  18. Potential of topic applications, leaf residues and soil drenches of the fungus Paecilomyces fumosoroseus (Deuteromycotina: Hyphomycetes) for management of the Diaprepes root weevil: laboratory and greenhouse investigations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diaprepes root weevil, (DRW) Diaprepes abbreviatus is a key pest of citrus and ornamental plants in Florida and Texas. DRW larvae burrow through the soil feeding on roots which when girdled causes secondary infection of the structural roots or root crown by Phytopthora spp. wherein mature citrus tre...

  19. Graphene oxide exhibits broad-spectrum antimicrobial activity against bacterial phytopathogens and fungal conidia by intertwining and membrane perturbation

    NASA Astrophysics Data System (ADS)

    Chen, Juanni; Peng, Hui; Wang, Xiuping; Shao, Feng; Yuan, Zhaodong; Han, Heyou

    2014-01-01

    To understand the interaction mechanism between graphene oxide (GO) and typical phytopathogens, a particular investigation was conducted about the antimicrobial activity of GO against two bacterial pathogens (P. syringae and X. campestris pv. undulosa) and two fungal pathogens (F. graminearum and F. oxysporum). The results showed that GO had a powerful effect on the reproduction of all four pathogens (killed nearly 90% of the bacteria and repressed 80% macroconidia germination along with partial cell swelling and lysis at 500 μg mL-1). A mutual mechanism is proposed in this work that GO intertwinds the bacteria and fungal spores with a wide range of aggregated graphene oxide sheets, resulting in the local perturbation of their cell membrane and inducing the decrease of the bacterial membrane potential and the leakage of electrolytes of fungal spores. It is likely that GO interacts with the pathogens by mechanically wrapping and locally damaging the cell membrane and finally causing cell lysis, which may be one of the major toxicity actions of GO against phytopathogens. The antibacterial mode proposed in this study suggests that the GO may possess antibacterial activity against more multi-resistant bacterial and fungal phytopathogens, and provides useful information about the application of GO in resisting crop diseases.To understand the interaction mechanism between graphene oxide (GO) and typical phytopathogens, a particular investigation was conducted about the antimicrobial activity of GO against two bacterial pathogens (P. syringae and X. campestris pv. undulosa) and two fungal pathogens (F. graminearum and F. oxysporum). The results showed that GO had a powerful effect on the reproduction of all four pathogens (killed nearly 90% of the bacteria and repressed 80% macroconidia germination along with partial cell swelling and lysis at 500 μg mL-1). A mutual mechanism is proposed in this work that GO intertwinds the bacteria and fungal spores with a wide range of aggregated graphene oxide sheets, resulting in the local perturbation of their cell membrane and inducing the decrease of the bacterial membrane potential and the leakage of electrolytes of fungal spores. It is likely that GO interacts with the pathogens by mechanically wrapping and locally damaging the cell membrane and finally causing cell lysis, which may be one of the major toxicity actions of GO against phytopathogens. The antibacterial mode proposed in this study suggests that the GO may possess antibacterial activity against more multi-resistant bacterial and fungal phytopathogens, and provides useful information about the application of GO in resisting crop diseases. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr04941h

  20. Use of a Granular Bioplastic Formulation for Carrying Conidia of a Non-aflatoxigenic Strain of Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research demonstrated that aflatoxin contamination in corn grown in Mississippi is reduced by field application of wheat grains pre-inoculated with the non-aflatoxigenic Aspergillus flavus strain NRRL 30797. To facilitate field applications of the biocontrol isolate, a series of laboratory ...

  1. rDNA-targeted PCR primers and FISH probe in the detection of Ophiocordyceps sinensis hyphae and conidia.

    PubMed

    Zhong, Xin; Peng, Qingyun; Qi, Lili; Lei, Wei; Liu, Xin

    2010-11-01

    Ophiocordyceps sinensis (Berk.) Sung, Sung, Hywel-Jones & Spatafora (syn. Cordyceps sinensis) one of the entomopathogenic fungi, is a rare Traditional Chinese Medicine (TCM) found in the Qinghai-Tibetan Plateau. Polymerase Chain Reaction (PCR) and Fluorescence in situ hybridization (FISH) methods are necessary to identify the mycelia or spores of O. sinensis from its habitat and to monitor its dispersal, colonization and infectivity. To develop both primers and probe specific to O. sinensis, ribosomal DNA (rDNA) amplified with universal primers from O. sinensis genomic DNA and seven closely related fungi were sequenced. According to these sequences, the upper and lower primers (OsT-F and OsT-R) were designed within internal transcribed spacer region 1 (ITS1) and ITS2 and flanked by universal primers ITS5 and ITS4, respectively. The designed primers were used for general PCR, touchdown PCR, or both together with the universal primers for nested-touchdown PCR. The results showed that only the extracted DNA of O. sinensis was specifically amplified. The sensitivity of nested-touchdown PCR with extracted DNA of O. sinensis is as low as 10(-14)g (10 fg) and at least 1000 times higher than the other PCR methods. In addition, Cy5-labeled probe (OsLSU) for cytoplasmic LSU rRNA was hybridized with the ascospores of O. sinensis. It showed a strong red fluorescence throughout the whole cell but did not cross-react with other entomopathogenic fungi. Taken together, these methods were useful for studying the biology and ecology of O. sinensis.

  2. Recovery of viability and radiation resistance by heat-injured conidia of Penicillium expansum Lk. ex Thom.

    PubMed

    Baldy, R W; Sommer, N F; Buckley, P M

    1970-05-01

    Spores heated in water at 54 C for up to 1 hr were plated on nutrient agar immediately or held for 3 days in aerated water at 23 C and then plated. Under these conditions, holding was optimal for recovery, increasing survival percentage up to 20-fold over values for immediate plating. Recovery was prevented partially or completely, however, when spores were held in any of the following solutions: glucose, potassium phosphate, ammonium or sodium acetate, sodium azide, or 2,4-dinitrophenol, or in the sodium or potassium salts of pyruvate, and tricarboxylic acid cycle acids. Both anaerobiosis and incubation at 0 C prevented recovery. Survivors of a heat treatment were more sensitive to gamma radiation than were unheated spores. Conditions which affected the recovery of viability had the same effect on restoration of radiation resistance. Thus, many of the processes for restoration of radiation resistance seem involved also in recovery of viability after heating. After a 99% inactivating treatment (about 30 min at 54 C), heated spores respired as fast as unheated spores, or faster. Malate, citrate, succinate, and acetate stimulated respiration in unheated spores and inhibited it in heated spores.

  3. Potential of two entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae (Coleoptera: Scarabaeidae), as biological control agents against the June beetle

    PubMed Central

    Erler, Fedai; Ates, A. Ozgur

    2015-01-01

    The aim of this study was to evaluate the effectiveness of the entomopathogenic fungi (EPF), Beauveria bassiana (Bals.) Vuill. (Deuteromycotina: Hyphomycetes) strain PPRI 5339 [BroadBand, an emulsifiable spore concentrate (EC) formulation] and Metarhizium anisopliae (Metsch.) Sorokin (Hypocreales: Clavicipitaceae) strain F52 [Met52, both EC and granular (GR) formulations] against the larvae of Polyphylla fullo (L.) (Coleoptera: Scarabaeidae). Larvicidal bioassays were performed in foam boxes (100 by 75 by 50 cm; length by width by height), containing moist soil medium with some humus and potato tubers as food. Although the B. bassiana product (min. 4 × 109 conidia/ml) was applied at 100, 150, and 200 ml/100 l water; M. anisopliae strain F52 was applied at 500, 1,000, and 1,500 g/m3 of moist soil medium for GR (9 × 108 cfu/g) and 75, 100, and 125 ml/100 l water for EC (5.5 × 109 conidia/ml) formulation. Both fungi were pathogenic to larvae of the pest; however, young larvae (1st and 2nd instars) were more susceptible to infection than older ones (3rd instar). Mortality rates of young and older larvae varied with conidial concentration of both fungi and elapsed time after application. The B. bassiana product was more effective than both of the formulations of the M. anisopliae product, causing mortalities up to 79.8 and 71.6% in young and older larvae, respectively. The highest mortality rates of young and older larvae caused by the M. anisopliae product were 74.1 and 67.6% for the GR formulation, 70.2 and 61.8% for the EC formulation, respectively. These results may suggest that both fungi have potential to be used for management of P. fullo. PMID:25881632

  4. Species and ecological diversity within the Cladosporium cladosporioides complex (Davidiellaceae, Capnodiales)

    PubMed Central

    Bensch, K.; Groenewald, J.Z.; Dijksterhuis, J.; Starink-Willemse, M.; Andersen, B.; Summerell, B.A.; Shin, H.-D.; Dugan, F.M.; Schroers, H.-J.; Braun, U.; Crous, P.W.

    2010-01-01

    The genus Cladosporium is one of the largest genera of dematiaceous hyphomycetes, and is characterised by a coronate scar structure, conidia in acropetal chains and Davidiella teleomorphs. Based on morphology and DNA phylogeny, the species complexes of C. herbarum and C. sphaerospermum have been resolved, resulting in the elucidation of numerous new taxa. In the present study, more than 200 isolates belonging to the C. cladosporioides complex were examined and phylogenetically analysed on the basis of DNA sequences of the nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA, as well as partial actin and translation elongation factor 1-α gene sequences. For the saprobic, widely distributed species Cladosporium cladosporioides, both a neotype and epitype are designated in order to specify a well established circumscription and concept of this species. Cladosporium tenuissimum and C. oxysporum, two saprobes abundant in the tropics, are epitypified and shown to be allied to, but distinct from C. cladosporioides. Twenty-two species are newly described on the basis of phylogenetic characters and cryptic morphological differences. The most important phenotypic characters for distinguishing species within the C. cladosporioides complex, which represents a monophyletic subclade within the genus, are shape, width, length, septation and surface ornamentation of conidia and conidiophores; length and branching patterns of conidial chains and hyphal shape, width and arrangement. Many of the treated species, e.g., C. acalyphae, C. angustisporum, C. australiense, C. basiinflatum, C. chalastosporoides, C. colocasiae, C. cucumerinum, C. exasperatum, C. exile, C. flabelliforme, C. gamsianum, and C. globisporum are currently known only from specific hosts, or have a restricted geographical distribution. A key to all species recognised within the C. cladosporioides complex is provided. PMID:20877444

  5. Potential of two entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae (Coleoptera: Scarabaeidae), as biological control agents against the June beetle.

    PubMed

    Erler, Fedai; Ates, A Ozgur

    2015-01-01

    The aim of this study was to evaluate the effectiveness of the entomopathogenic fungi (EPF), Beauveria bassiana (Bals.) Vuill. (Deuteromycotina: Hyphomycetes) strain PPRI 5339 [BroadBand, an emulsifiable spore concentrate (EC) formulation] and Metarhizium anisopliae (Metsch.) Sorokin (Hypocreales: Clavicipitaceae) strain F52 [Met52, both EC and granular (GR) formulations] against the larvae of Polyphylla fullo (L.) (Coleoptera: Scarabaeidae). Larvicidal bioassays were performed in foam boxes (100 by 75 by 50 cm; length by width by height), containing moist soil medium with some humus and potato tubers as food. Although the B. bassiana product (min. 4 × 10(9) conidia/ml) was applied at 100, 150, and 200 ml/100 l water; M. anisopliae strain F52 was applied at 500, 1,000, and 1,500 g/m(3) of moist soil medium for GR (9 × 10(8) cfu/g) and 75, 100, and 125 ml/100 l water for EC (5.5 × 10(9) conidia/ml) formulation. Both fungi were pathogenic to larvae of the pest; however, young larvae (1st and 2nd instars) were more susceptible to infection than older ones (3rd instar). Mortality rates of young and older larvae varied with conidial concentration of both fungi and elapsed time after application. The B. bassiana product was more effective than both of the formulations of the M. anisopliae product, causing mortalities up to 79.8 and 71.6% in young and older larvae, respectively. The highest mortality rates of young and older larvae caused by the M. anisopliae product were 74.1 and 67.6% for the GR formulation, 70.2 and 61.8% for the EC formulation, respectively. These results may suggest that both fungi have potential to be used for management of P. fullo.

  6. Common but different: The expanding realm of Cladosporium.

    PubMed

    Bensch, K; Groenewald, J Z; Braun, U; Dijksterhuis, J; de Jesús Yáñez-Morales, M; Crous, P W

    2015-09-01

    The genus Cladosporium (Cladosporiaceae, Dothideomycetes), which represents one of the largest genera of dematiaceous hyphomycetes, has been intensively investigated during the past decade. In the process, three major species complexes (C. cladosporioides, C. herbarum and C. sphaerospermum) were resolved based on morphology and DNA phylogeny, and a monographic revision of the genus (s. lat.) published reflecting the current taxonomic status quo. In the present study a further 19 new species are described based on phylogenetic characters (nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, as well as partial actin and translation elongation factor 1-α gene sequences) and morphological differences. For a selection of the species with ornamented conidia, scanning electron microscopic photos were prepared to illustrate the different types of surface ornamentation. Surprisingly, during this study Cladosporium ramotenellum was found to be a quite common saprobic species, being widely distributed and occurring on various substrates. Therefore, an emended species description is provided. Furthermore, the host range and distribution data for several previously described species are also expanded.

  7. Ultrastructural and cytochemical characterization of brown soft scale Coccus hesperidum (Hemiptera: Coccidae) infected by the Lecanicillium lecanii (Ascomycota: Hypocreales).

    PubMed

    Liu, Weimin; Xie, Yingping; Xue, Jiaoliang; Zhang, Yanfeng; Zhang, Xiaomin

    2011-01-01

    The ultrastructural and cytochemical characterization of the brown soft scale, Coccus hesperidum L. (Hemiptera: Coccidae) infected by the hyphomycete Lecanicillium lecanii (Zimmermann) Gams & Zare, belonging to the phylum Ascomycota and order Hypocreales, was investigated by light, scanning and transmission electron microscopy. Gold cytochemistry was used to label chitin in the cuticle of the scale insect. The results revealed that the pathogenic fungus, L. lecanii generally infected by penetrating the integument, especially at anus, vulva, spiracles, stigmatic furrow, body margin, and the areas of cuticle with grooves, fissures and rugoses areas. The conidia became attached to the host body surface and germinated into hyphae that established colonies by branching repeatedly. Hyphae penetrated the integument by means of their penetration pegs using mechanical force and extracellular enzymes. During integument penetration, the hyphae extended vertically or parallel along the cuticle. Labeling with the WGA/Ovo-G complex showed disruption of the parallel sheets of chitin and a decrease in the density of the gold particles surrounding the penetrated hyphae. Hyphal invasion also separated the cuticle and epidermis from each other. Once in the haemocoele, blastospores of the fungus infected the haemocytes and internal organs. After some time, the nutritive value of the haemocoele decreased and the insect's internal organs disappeared. The hyphae then produced conidiophores and released them through the cuticle of the scale insect cadaver.

  8. [Cultural Properties and Taxonomic Position of Helminthosporium-Like Fungal Isolates from the White Sea].

    PubMed

    Kireev, Ya V; Konovalova, O P; Myuge, N S; Shnyreva, A V; Bubnova, E N

    2015-01-01

    Morphological, cultural and physiological characteristics of 19 Helminthosporium-like hyphomycetes isolated from the White Sea were studied. Taxonomic status of the isolates was verified using molecular genetics techniques. One of the isolates was identified as Alternatia sp., while the rest of marine isolates belonged to the species Paradendriphiella salina (G.K. Sutherl.) Woudenb. & Crous. The specific features of the isolates studied were characterized as adaptive. Optimum salinity for their growth was 1-2% NaCl, which is lower than the value for the known open ocean isolates. This is probably due to relatively low salinity of White Sea (22-24 per thousand) as compared with the ocean water (35 per thousand). While the temperature optimum for growth was 22 per thousand, growth and sporulation occurred at 6 degrees C, which has not been reported for marine fungi isolated from warmer seawater. All isolates studied grew and sporulated efficiently on the medium supplied with the Fucus algae extract and in the sea water layer. Conidia of the isolates submerged in the sea water were propagated efficiently, unlike the soil-born fungi. Holoblastic conidiogenesis was demonstrated by light and scanning electron microscopy, confirming the separation of P. salina from the genus Scolecobasidium.

  9. [Infectivity of the entomopathogenic fungus Verticillium lecanii in mice and guinea pigs].

    PubMed

    Mier, T; Rivera, F; Rodríguez-Ponce, M P; Carrillo-Farga, J; Toriello, C

    1994-01-01

    The resistance of plague insects to chemical insecticides as well as the importance of a healthy environment demands an alternative for agricultural plagues. Among others, biological control seems an alternate strategy with fungal entomopathogens playing a relevant role. The hyphomycete Verticillium lecanii is a natural bioregulator of aphids, scales and white-flies that attack different agricultural plantations. Its use in biological control programs must be assessed previously by safety procedures such as its innocuity in mammals and useful animals and plants. The aim of this study was pointed at demonstrating the innocuity of V. lecanii in mice and guinea pigs. Two strains of the fungus were injected intraperitoneally (10(8) conidia/kg of animal weight) to 130 mice and 66 guinea pigs. Two control groups were included, one injected with heat-killed fungi and the other with sterile physiological saline. The animals were killed at 8, 30 and 70 days after infection, and mycological and histopathological studies performed in their organs. Negative results obtained with the live fungus in the same manner as the two control groups, suggest the innocuity of V. lecanii in mice and guinea pigs.

  10. Studies on mould growth and biomass production using waste banana peel.

    PubMed

    Essien, J P; Akpan, E J; Essien, E P

    2005-09-01

    Hyphomycetous (Aspergillus fumigatus) and Phycomycetous (Mucor hiemalis) moulds were cultivated in vitro at room temperature (28 + 20 degrees C) to examined their growth and biomass production on waste banana peel agar (BPA) and broth (BPB) using commercial malt extract agar (MEA) and broth (MEB) as control. The moulds grew comparatively well on banana peel substrates. No significant difference (p > 0.05) in radial growth rates was observed between moulds cultivated on PBA and MEA, although growth rates on MEA were slightly better. Slight variations in sizes of asexual spores and reproductive hyphae were also observed between moulds grown on MEA and BPA. Smaller conidia and sporangiospores, and shorter aerial hyphae (conidiophores and sporangiophores) were noticed in moulds grown on BPA than on MEA. The biomass weight of the test moulds obtained after one month of incubation with BPB were only about 1.8 mg and 1.4 mg less than values recorded for A. fumigatus and M. hiemalis respectively, grown on MEB. The impressive performance of the moulds on banana peel substrate may be attributed to the rich nutrient (particularly the crude protein 7.8% and crude fat 11.6% contents) composition of banana peels. The value of this agricultural waste can therefore be increased by its use not only in the manufacture of mycological medium but also in the production of valuable microfungal biomass which is rich in protein and fatty acids.

  11. Common but different: The expanding realm of Cladosporium

    PubMed Central

    Bensch, K.; Groenewald, J.Z.; Braun, U.; Dijksterhuis, J.; de Jesús Yáñez-Morales, M.; Crous, P.W.

    2015-01-01

    The genus Cladosporium (Cladosporiaceae, Dothideomycetes), which represents one of the largest genera of dematiaceous hyphomycetes, has been intensively investigated during the past decade. In the process, three major species complexes (C. cladosporioides, C. herbarum and C. sphaerospermum) were resolved based on morphology and DNA phylogeny, and a monographic revision of the genus (s. lat.) published reflecting the current taxonomic status quo. In the present study a further 19 new species are described based on phylogenetic characters (nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, as well as partial actin and translation elongation factor 1-α gene sequences) and morphological differences. For a selection of the species with ornamented conidia, scanning electron microscopic photos were prepared to illustrate the different types of surface ornamentation. Surprisingly, during this study Cladosporium ramotenellum was found to be a quite common saprobic species, being widely distributed and occurring on various substrates. Therefore, an emended species description is provided. Furthermore, the host range and distribution data for several previously described species are also expanded. PMID:26955200

  12. Diversity of endophytic fungi in the roots of mangrove species on the west coast of India.

    PubMed

    Ananda, K; Sridhar, K R

    2002-10-01

    Because mangrove plant species are a valuable source of useful metabolites, their endophytes have gained more importance. Randomly sampled surface-sterilized whole root segments of four mangrove plant species, Acanthus ilicifolius, Avicennia officinalis, Rhizophora mucronata, and Sonneratia caseolaris from the mangroves of Udyavara (Karnataka) on the west coast of India, were characterized for fungal communities by direct plating, damp chamber, and bubbling chamber incubation methods. The richness of endophytic fungal species from whole root segments after direct plating and damp chamber incubation was greatest for R. mucronata than for other plants (18 vs. 8-13). Incubation of whole root segments in bubbling chambers yielded conidia of two freshwater hyphomycetes: Mycocentrospora acerina (in Avicennia officinalis) and Triscelophorus acuminatus (in R. mucronata and in S. caseolaris). Surface-sterilized whole root and root bark segments of R. mucronata sampled from the mid-tide level on direct plating yielded more fungi than that of the root segments sampled from low-tide and high-tide levels. The greatest number of isolates, species richness, and diversity of fungi were shown by the whole root segments of R. mucronata from the mid-tide level. Rarefaction indices also revealed the highest expected number of species out of 150 random isolations from the mid-tide level samples of whole root and root bark segments of R. mucronata. The present study showed that fungi in mangrove roots are composed of a consortium of soil, marine, and freshwater fungi.

  13. Selection of Wetting Agent for Dried Conidia of two Beauveria bassiana Strains from Different Production Systems to Control Tarnished Plant Bugs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hydrophilic–lipophilic balance (HLB) number was used to select surfactant, TDA (polyoxy-ethylene tridecyl ether) with a range of HLB numbers in formulation development of two Beauveria bassiana strains, NI8 and GHA produced from different systems. The results indicated that optimal HLB number of...

  14. Application of modified atmosphere packaging (gas flushing and active packaging) for extending the shelf life of Beauveria bassiana conidia at high temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited shelf life has long been a major constraint to the development of fungus-based bioinsecticides (mycoinsecticides). Fungal spores comprising the active ingredients of most products typically lose viability within a few months when stored in conventional packaging at temperatures >30 deg C. Me...

  15. Virulence of Mexican isolates of entomopathogenic fungi upon Rhipicephalus-Boophilus microplus larvae and the efficacy of conidia formulations to reduce larval tick density under field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The first objective was laboratory evaluation of the virulence of 53 Mexican isolates of fungi against larvae of Rhipicephalus (Boophilus) microplus. Thirty three isolates of Metarhizium anisopliae var. anisopliae (Metschnickoff) Sorokin (Hypocreales: Clavicipitaceae) and 20 isolates of Isaria (Paec...

  16. A RAPID METHOD FOR THE EXTRACTION OF FUNGAL DNA FROM ENVIRONMENTAL SAMPLES: EVALUATION IN THE QUANTITATIVE ANALYSIS OF MEMNONIELLA ECHINATA CONIDIA USING REAL TIME DETECTION OF PCR PRODUCTS

    EPA Science Inventory

    New technologies are creating the potential for using nucleic acid sequence detection to perform routine microbiological analyses of environmental samples. Our laboratory has recently reported on the development of a method for the quantitative detection of Stachybotrys chartarum...

  17. Fungal propagules and DNA in feces of two detritus-feeding amphipods.

    PubMed

    Sridhar, Kandikere Ramaiah; Beaton, Margaret; Bärlocher, Felix

    2011-01-01

    Aquatic shredders (leaf-eating invertebrates) preferentially ingest and digest leaves colonized by aquatic hyphomycetes (fungi). This activity destroys leaf-associated fungal biomass and detritial resources in streams. Fungal counter-adaptations may include the ability to survive passage through the invertebrate's digestive tract. When fecal pellets of Gammarus tigrinus and Hyalella azteca were incubated with sterile leaves, spores of nine (G. tigrinus) and seven (H. azteca) aquatic hyphomycete species were subsequently released from the leaves, indicating the presence of viable fungal structures in the feces. Extraction, amplification, and sequencing of DNA from feces revealed numerous fungal phylotypes, two of which could be assigned unequivocally to an aquatic hyphomycete. The estimated contributions of major fungal groups varied depending on whether 18S or ITS sequences were amplified and cloned. We conclude that a variable proportion of fungal DNA in the feces of detritivores may originate from aquatic hyphomycetes. Amplified DNA may be associated with metabolically active, dormant, or dead fungal cells.

  18. Evaluation of Metarhizium anisopliae, Beauveria bassiana and Paecilomyces fumosoroseus as entomopathogens of the cactus moth, Cactoblastis cactorum (Lepidoptera:Pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal pathogens Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae), Paecilomyces fumosoroseus (Wize) Brown & Smith (Deuteromycotina: Hyphomycetes), and Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Clavicipitaceae) were evaluated as potential biological control ...

  19. Assessment of Fungal Pathogens as Biocontrol Agents of Myriophyllum Spicatum.

    DTIC Science & Technology

    1996-01-01

    Gliocladium roseum, 2 Indeterminate Hyphomycete (producing only chlamydospores), Acremoniurn sp, Cylindrocarpon destructans, Embeilisia nr. telituster, Fusarium ... solani , Geotrchum candidum Coniothyrium fuckelli, Cryptosporiopsis sp, Glomerella cingulata and an Indeterminate Coelomycete.

  20. Do Invertebrate Activity and Current Velocity Affect Fungal Assemblage Structure in Leaves?

    NASA Astrophysics Data System (ADS)

    Ferreira, Verónica; Graça, Manuel A. S.

    2006-02-01

    In this study we assessed the effect of current velocity and shredder presence, manipulated in artificial channels, on the structure of the fungal assemblage colonizing alder (Alnus glutinosa (L.) Gaertner) leaves incubated in coarse and fine mesh bags. Fungal sporulation rates, cumulative conidial production and number of species of aquatic hyphomycetes were higher in leaves exposed to high rather than to low current velocity. The opposite was observed regarding Simpson's index (D) on the fungal assemblage. Some species of aquatic hyphomycetes were consistently stimulated in high current channels. No effect of shredders or of mesh type was observed.

  1. Two new species of Stemphylium from Northwest China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During surveys of hyphomycetes from the Northwest of China, two undescribed taxa of Stemphylium were discovered from diseased leaves of Malus sieversii and Pyrus sinkiangensis in Sinkiang Provence, which are described as S. mali and S. pyrinum. The two species differ from similar species morphologi...

  2. Potassium influences forage bermudagrass yield and fungal leaf disease severity in Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf spot diseases are associated with K deficiency in forage bermudagrass. In 2010, a natural disease epiphytotic caused by six species of Bipolaris, Curvularia, and Exserohilum (dematiaceous hyphomycetes) was evaluated in 56 plots of ‘Tifton 44' bermudagrass in Mississippi. Pathogen occurrence, di...

  3. FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection

    PubMed Central

    Sinha, Meenal; McCabe, Orla; Palmer, Jonathan M.; Choera, Tsokyi; Yun Lim, Fang; Wimmerova, Michaela; Carrington, Stephen D.; Yuan, Shaopeng; Lowell, Clifford A.; Oscarson, Stefan; Keller, Nancy P.; Fahy, John V.

    2016-01-01

    The immune mechanisms that recognize inhaled Aspergillus fumigatus conidia to promote their elimination from the lungs are incompletely understood. FleA is a lectin expressed by Aspergillus fumigatus that has twelve binding sites for fucosylated structures that are abundant in the glycan coats of multiple plant and animal proteins. The role of FleA is unknown: it could bind fucose in decomposed plant matter to allow Aspergillus fumigatus to thrive in soil, or it may be a virulence factor that binds fucose in lung glycoproteins to cause Aspergillus fumigatus pneumonia. Our studies show that FleA protein and Aspergillus fumigatus conidia bind avidly to purified lung mucin glycoproteins in a fucose-dependent manner. In addition, FleA binds strongly to macrophage cell surface proteins, and macrophages bind and phagocytose fleA-deficient (∆fleA) conidia much less efficiently than wild type (WT) conidia. Furthermore, a potent fucopyranoside glycomimetic inhibitor of FleA inhibits binding and phagocytosis of WT conidia by macrophages, confirming the specific role of fucose binding in macrophage recognition of WT conidia. Finally, mice infected with ΔfleA conidia had more severe pneumonia and invasive aspergillosis than mice infected with WT conidia. These findings demonstrate that FleA is not a virulence factor for Aspergillus fumigatus. Instead, host recognition of FleA is a critical step in mechanisms of mucin binding, mucociliary clearance, and macrophage killing that prevent Aspergillus fumigatus pneumonia. PMID:27058347

  4. Biological control of Spreading Dayflower (Commelina diffusa) with the fungal pathogen Phoma commelinicola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouse and field experiments showed that conidia of the fungal pathogen, Phoma commelinicola exhibited bioherbicidal activity on spreading dayflower (Commelina diffusa) seedlings when applied at concentrations of 106 to 109 conidia ml-1. Greenhouse tests determined an optimal temperature for co...

  5. Conidial vigor vs. viability as predictors of virulence of entomopathogenic fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We tested the hypothesis that debilitated conidia exhibiting slow-germination (requiring greater than 16 hours to germinate) are less virulent than vigorous conidia exhibiting fast germination (requiring less than or equal to 16 hours to germinate). Preparations of Beauveria bassiana s.l. strain CG ...

  6. Ulocladium cantlous sp. nov. isolated from Northwest China: morphology and molecular phylogenetic position

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species of Ulocladium was isolated from diseased leaves from two Cucumis spp. growing in Sinkiang and Gansu Provinces of China. Conidia were isolated from diseased leaf areas, grown in single-spore pure culture, and conidia harvested 1, 3, and 7 days after incubation for morphological comparis...

  7. Morphology and molecular taxonomy of Evlachovaea-like fungi, and the status of this unusual conidial genus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The entomopathogenic anamorphic genus Evlachovaea was described to differ from other fungi in forming its conidia obliquely to the axis of the conidiogenous cell and with successive conidia having alternate orientations with a zipper- or chevron-like arrangement resulting in flat, ribbon-like chains...

  8. Comparative efficacy of emulsifiable-oil, wettable-powder, and unformulated-powder preparations of Beauveria bassiana against the melon aphid Aphis gossypii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aphicidal efficacy of two commercial formulations of Beauveria bassiana strain GHA conidia, an emulsifiable-paraffinic oil dispersion (OD) and a clay-based wettable powder (WP), were compared to unformulated conidia in laboratory tests with adult melon aphids (Aphis gossypii). For the initial 24 hou...

  9. Presence of adhesive vesicles in the mycoherbicide Alternaria helianthi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria helianthi conidia have been shown to cause disease on common cocklebur. Conidia were applied to slides made hydrophobic by coating with dimethyldicholorosilane (mimics leaf surface), then rinsed and treated with FITC-Con A to stain the adhesive material. Alternaria helianthi coni...

  10. Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

    NASA Technical Reports Server (NTRS)

    Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

    1991-01-01

    Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

  11. Interaction of Aceria mangiferae with Fusarium mangiferae, the causal agent of mango malformation disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study examines the role of the mango bud mite, Aceria mangiferae, in carrying Fusarium mangiferae’s conidia, vectoring them into the penetration sites and assisting fungal penetration and dissemination. Conidia that were exposed to a green fluorescent protein (gfp)-marked isolate of F. mangifer...

  12. Variabilities of two Drechslerella dactyloides isolates in Korea and high predacity against Bursaphelenchus xylophilus.

    PubMed

    Wang, Zhen; Wang, Chun-Yan; Gu, Li-Juan; Sun, Bai-Shen; Zhang, Dong-Liang; Liu, Lei; Lee, Mi-Ra; Wang, Chun-Ling; Li, Zheng; Mo, Eun-Kyung; Sung, Chang-Keun

    2011-02-01

    Drechslerella dactyloides generates elongate ellipsoid conidia and three-celled rings. Recently, Drechslerella dactyloides CNU 091025 and CNU 091026 were isolated in Korea, which generated elongate ellipsoid, Y-shaped and reaphook-shaped conidia, three-celled rings and fishhook-shaped traps. Therefore, molecular phylogenetic analysis, morphological variability, and nematode capturing ability were tested in this study. CNU 091025 generated two-celled or three-celled Y-shaped conidia, reaphook-shaped conidia, and elongate ellipsoid conidia, 17.2, 40.9, and 41.9%, respectively. Some fishhook-shaped rings connecting together formed two-dimensional web. Both fungi showed high trap-forming and nematode-capturing ability; especially CNU 091026 captured 100% Bursaphelenchus xylophilus within 24 h after inoculation.

  13. Soil mycoflora from the Dead Sea Oases of Ein Gedi and Einot Zuqim (Israel).

    PubMed

    Steiman, R; Guiraud, P; Sage, L; Seigle-Murandi, F

    1997-10-01

    Samples were taken from the top 10 cm of soils from 24 points in the Ein Gedi area. Among 329 isolates, 142 species were identified: 11 genera of ascomycetes, one genus of coelomycetes, 28 genera of hyphomycetes, 7 genera of zygomycetes and one yeast, in addition to some unidentified basidiomycetes. The hyphomycetes were represented by 17 dematiaceous, 9 mucedinaceous and two tuberculariaceous. Melanconiaceous and stilbellaceous genera were not found. Two new varieties of Microascus recently described were reisolated. No strict thermophiles or halophiles were obtained. There is apparently no very characteristic or specific fungal flora of the Dead Sea Oases although it was different from that found in the desert soil surrounding this area.

  14. Influence of leaf quality in microbial decomposition in a headwater stream in the Brazilian cerrado: a 1-year study.

    PubMed

    Sales, M A; Gonçalves, J F; Dahora, J S; Medeiros, A O

    2015-01-01

    The temporal dynamics of leaf decomposition in a tropical stream were evaluated by measuring the input of leaves from riparian vegetation. The resulting mixture of leaves was processed by decomposer microorganisms and, in particular, by aquatic hyphomycetes, the most important microorganisms associated with leaf litter decomposition. Leaf decomposition and the characteristics and activity of the microbial community were investigated over the course of 1 year; these parameters depended on the composition and availability of leaves in the stream. We assessed the biomass, activity, and community structure of the fungi associated with the decomposing leaf mixtures monthly in a tropical stream with little seasonal variation in water characteristics. The leaf material included 27 riparian species; the amount of leaves of each contributing species varied from month to month, with higher overall values in the rainy season. Leaf decomposition was slow, and leaf mass loss did not occur monthly; however, leaf mass loss was significantly lower in May and September. The values of ATP, the ergosterol concentration, and the sporulation of aquatic hyphomycetes varied during the experiment, and only the ergosterol concentration (fungal biomass) was correlated with leaf mass loss. The sporulation rates of aquatic hyphomycetes peaked at the beginning of the rainy season (October), when only three hyphomycete species were present out of the total of seven that were found during the year. In this tropical stream, where the physical and chemical characteristics of the stream water varied little during the year, we hypothesize that changes related to leaf chemical composition could be the cause of changes in decomposition and the abundance and composition of the fungal assemblages. No significant differences were found for the parameters analyzed (lignin, cellulose, fiber, phosphorous, and polyphenols).

  15. Leaf Barriers to Fungal Colonization and Shredders (Tipula lateralis) Consumption of Decomposing Eucalyptus globulus.

    PubMed

    Canhoto; Graça

    1999-04-01

    > Abstract Herein we assess the importance of leaf cuticle, polyphenolic, and essential oils contents of Eucalyptus globulus leaves to hyphomycete colonization and shredder consumption. Optical and electron microscopy revealed that, at least during the first 5 weeks of conditioning, the cuticle remains virtually intact. Stomata provide the main access for hyphae to internal leaf tissues and, eventually, for spore release. We suggest that in E. globulus leaves, fungal decomposition progresses predominantly in and from the eucalyptus leaf mesophyll to the outside. Malt extract agar media supplemented with either eucalyptus essential oils or tannic acid completely inhibited (Articulospora tetracladia, Lemonniera aquatica, and Tricladium gracile) or depressed (Heliscus lugdunensis, Lunulospora curvula, and Tricladium angulatum) aquatic hyphomycetes growth. The transference of both secondary compounds to alder leaves induced similar and significant reduction in Tipula lateralis larval consumption. Results consistently indicate that eucalyptus oils are stronger deterrents than polyphenols. The waxy cuticle of E. globulus appears to be a key physical factor delaying fungal colonization during decomposition. We hypothesize that the relative influence of leaf phenols and essential oils to aquatic hyphomycetes and shredders may be related to three main factors: (a) initial distribution of such compounds in the leaves; (b) possibility of their decrease through decomposition; and (c) consumption strategies of detritivores.

  16. Temperature affects leaf litter decomposition in low-order forest streams: field and microcosm approaches.

    PubMed

    Martínez, Aingeru; Larrañaga, Aitor; Pérez, Javier; Descals, Enrique; Pozo, Jesús

    2014-01-01

    Despite predicted global warming, the temperature effects on headwater stream functioning are poorly understood. We studied these effects on microbial-mediated leaf decomposition and the performance of associated aquatic hyphomycete assemblages. Alder leaves were incubated in three streams differing in winter water temperature. Simultaneously, in laboratory, leaf discs conditioned in these streams were incubated at 5, 10 and 15 °C. We determined mass loss, leaf N and sporulation rate and diversity of aquatic hyphomycete communities. In the field, decomposition rate correlated positively with temperature. Decomposition rate and leaf N presented a positive trend with dissolved nutrients, suggesting that temperature was not the only factor determining the process velocity. Under controlled conditions, it was confirmed that decomposition rate and leaf N were positively correlated with temperature, leaves from the coldest stream responding most clearly. Sporulation rate correlated positively with temperature after 9 days of incubation, but negatively after 18 and 27 days. Temperature rise affected negatively the sporulating fungi richness and diversity only in the material from the coldest stream. Our results suggest that temperature is an important factor determining leaf processing and aquatic hyphomycete assemblages and that composition and activity of fungal communities adapted to cold environments could be more affected by temperature rises. Highlight: Leaf decomposition rate and associated fungal communities respond to temperature shifts in headwater streams.

  17. Aspergillus fumigatus spore proteomics and genetics reveal that VeA represses DefA-mediated DNA damage response.

    PubMed

    Shin, Kwang-Soo; Park, Hee-Soo; Kim, Young; Heo, In-Beom; Kim, Young Hwan; Yu, Jae-Hyuk

    2016-10-04

    Aspergillus fumigatus reproduces and infects host by forming a high number of small asexual spores (conidia). The velvet proteins are global transcriptional regulators governing the complex process of conidiogenesis in this fungus. Here, to further understand the velvet-mediated regulation, we carried out comparative proteomic analyses of conidia of wild type (WT) and three velvet mutants (ΔveA, ΔvelB and ΔvosA). Cluster analysis of 184 protein spots showing at least 1.5-fold differential accumulation between WT and mutants reveal the clustering of WT- ΔveA and ΔvelB-ΔvosA. Among 43 proteins identified by Nano-LC-ESI-MS/MS, 23 including several heat shock proteins showed more than two-fold reduction in both the ∆velB and ∆vosA conidia. On the contrary, three proteins exhibited more than five-fold increase in ∆veA only, including the putative RNA polymerase II degradation factor DefA. The deletion of defA resulted in a reduced number of conidia and restricted colony growth. In addition, the defA deletion mutant conidia showed hypersensitivity against the DNA damaging agents NQO and MMS, while the ΔveA mutant conidia were more resistant against to NQO. Taken together, we propose that VeA controls protein level of DefA in conidia, which are dormant and equipped with multiple layers of protection against environmental cues.

  18. Abundant respirable ergot alkaloids from the common airborne fungus Aspergillus fumigatus.

    PubMed

    Panaccione, Daniel G; Coyle, Christine M

    2005-06-01

    Ergot alkaloids are mycotoxins that interact with several monoamine receptors, negatively affecting cardiovascular, nervous, reproductive, and immune systems of exposed humans and animals. Aspergillus fumigatus, a common airborne fungus and opportunistic human pathogen, can produce ergot alkaloids in broth culture. The objectives of this study were to determine if A. fumigatus accumulates ergot alkaloids in a respirable form in or on its conidia, to quantify ergot alkaloids associated with conidia produced on several different substrates, and to measure relevant physical properties of the conidia. We found at least four ergot alkaloids, fumigaclavine C, festuclavine, fumigaclavine A, and fumigaclavine B (in order of abundance), associated with conidia of A. fumigatus. Under environmentally relevant conditions, the total mass of ergot alkaloids often constituted >1% of the mass of the conidium. Ergot alkaloids were extracted from conidia produced on all media tested, and the greatest quantities were observed when the fungus was cultured on latex paint or cultured maize seedlings. The values for physical properties of conidia likely to affect their respirability (i.e., diameter, mass, and specific gravity) were significantly lower for A. fumigatus than for Aspergillus nidulans, Aspergillus niger, and Stachybotrys chartarum. The demonstration of relatively high concentrations of ergot alkaloids associated with conidia of A. fumigatus presents opportunities for investigations of potential contributions of the toxins to adverse health effects associated with the fungus and to aspects of the biology of the fungus that contribute to its success.

  19. Conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans: influence of growth conditions and antifungal susceptibility profiles

    PubMed Central

    de Mello, Thaís Pereira; Aor, Ana Carolina; de Oliveira, Simone Santiago Carvalho; Branquinha, Marta Helena; dos Santos, André Luis Souza

    2016-01-01

    In the present study, we have investigated some growth conditions capable of inducing the conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans. Germination in Sabouraud medium (pH 7.0, 37ºC, 5% CO2) showed to be a typically time-dependent event, reaching ~75% in S. minutisporum and > 90% in S. apiospermum, S. aurantiacum and L. prolificans after 4 h. Similar germination rate was observed when conidia were incubated under different media and pHs. Contrarily, temperature and CO2 tension modulated the germination. The isotropic conidial growth (swelling) and germ tube-like projection were evidenced by microscopy and cytometry. Morphometric parameters augmented in a time-dependent fashion, evidencing changes in size and granularity of fungal cells compared with dormant 0 h conidia. In parallel, a clear increase in the mitochondrial activity was measured during the transformation of conidia-into-germinated conidia. Susceptibility profiles to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin varied regarding each morphotype and each fungal species. Overall, the minimal inhibitory concentrations for hyphae were higher than conidia and germinated conidia, except for caspofungin. Collectively, our study add new data about the conidia-into-hyphae transformation in Scedosporium and Lomentospora species, which is a relevant biological process of these molds directly connected to their antifungal resistance and pathogenicity mechanisms. PMID:27355215

  20. Interactions of Aspergillus fumigatus with endothelial cells: internalization, injury, and stimulation of tissue factor activity.

    PubMed

    Lopes Bezerra, Leila M; Filler, Scott G

    2004-03-15

    Invasive aspergillosis causes significant mortality among patients with hematologic malignancies. This infection is characterized by vascular invasion and thrombosis. To study the pathogenesis of invasive aspergillosis, we investigated the interactions of Aspergillus fumigatus conidia and hyphae with endothelial cells in vitro. We found that both forms of the organism induced endothelial cell microfilament rearrangement and subsequent endocytosis. Conidia were endocytosed 2-fold more avidly than hyphae, and endocytosis was independent of fungal viability. Endocytosed conidia and hyphae caused progressive endothelial cell injury after 4 hours of infection. Live conidia induced more endothelial cell injury than did live hyphae. However, endothelial cell injury caused by conidia was dependent on fungal viability, whereas injury caused by hyphae was not, indicating that conidia and hyphae injure endothelial cells by different mechanisms. Neither live nor killed conidia increased tissue factor activity of endothelial cells. In contrast, both live and killed hyphae stimulated significant endothelial cell tissue factor activity, as well as the expression of tissue factor antigen on the endothelial cell surface. These results suggest that angioinvasion and thrombosis caused by A fumigatus hyphae in vivo may be due in part to endothelial cell invasion, induction of injury, and stimulation of tissue factor activity.

  1. Insight into the feeding behavior of predatory mites on Beauveria bassiana, an arthropod pathogen

    PubMed Central

    Wu, Shengyong; Zhang, Ye; Xu, Xuenong; Lei, Zhongren

    2016-01-01

    Interactions between fungal entomopathogens and pest predators are particularly relevant in control of agricultural insect pests. In a laboratory study, we confirmed that the predatory mite, Neoseiulus barkeri, exhibited feeding behavior on the entomopathogenic fungus Beauveria bassiana conidia through DNA extracts. Using transmission electron microscopy, we determined that the majority of conidia found in the mite gut tended to dissolve within 24 h post ingestion, suggesting that the conidia had probably lost their viability. To our knowledge this is the first report of feeding behavior of phytoseiid mites on entomopathogenic fungus. The findings expand our knowledge of fungus–predator interactions. PMID:27041703

  2. Insight into the feeding behavior of predatory mites on Beauveria bassiana, an arthropod pathogen.

    PubMed

    Wu, Shengyong; Zhang, Ye; Xu, Xuenong; Lei, Zhongren

    2016-04-04

    Interactions between fungal entomopathogens and pest predators are particularly relevant in control of agricultural insect pests. In a laboratory study, we confirmed that the predatory mite, Neoseiulus barkeri, exhibited feeding behavior on the entomopathogenic fungus Beauveria bassiana conidia through DNA extracts. Using transmission electron microscopy, we determined that the majority of conidia found in the mite gut tended to dissolve within 24 h post ingestion, suggesting that the conidia had probably lost their viability. To our knowledge this is the first report of feeding behavior of phytoseiid mites on entomopathogenic fungus. The findings expand our knowledge of fungus-predator interactions.

  3. DIFFERENTIAL ALLERGIC AND NEUROTROPHIN RESPONSES TO FUNGAL COMPONENT EXTRACTS IN BALB/C MICE

    EPA Science Inventory

    Metarhizium anisopliae mycelium (MYC), conidia (CON) and inducible protease (IND) extracts were combined to produce the antigen MACA to screen for allergenic potential. Involuntary aspiration (IA) exposure to MACA in BALB/c mice has caused immune, inflammatory and physiological ...

  4. Differential allergy responses to Metarhizium anisopliae fungal component extracts in BALB/c mice

    EPA Science Inventory

    Intratracheal aspiration (IA) exposure to Metarhizium anisopliae crude antigen (MACA), which is composed of equal protein amounts of mycelium (MYC), conidia (CON) and inducible proteases/chitinases (IND) extracts/filtrates, has resulted in responses characteristic of human allerg...

  5. Conidial Dihydroxynaphthalene Melanin of the Human Pathogenic Fungus Aspergillus fumigatus Interferes with the Host Endocytosis Pathway

    PubMed Central

    Thywißen, Andreas; Heinekamp, Thorsten; Dahse, Hans-Martin; Schmaler-Ripcke, Jeannette; Nietzsche, Sandor; Zipfel, Peter F.; Brakhage, Axel A.

    2011-01-01

    Aspergillus fumigatus is the most important air-borne fungal pathogen of humans. The interaction of the pathogen with the host's immune system represents a key process to understand pathogenicity. For elimination of invading microorganisms, they need to be efficiently phagocytosed and located in acidified phagolysosomes. However, as shown previously, A. fumigatus is able to manipulate the formation of functional phagolysosomes. Here, we demonstrate that in contrast to pigmentless pksP mutant conidia of A. fumigatus, the gray-green wild-type conidia inhibit the acidification of phagolysosomes of alveolar macrophages, monocyte-derived macrophages, and human neutrophil granulocytes. Therefore, this inhibition is independent of the cell type and applies to the major immune effector cells required for defense against A. fumigatus. Studies with melanin ghosts indicate that the inhibitory effect of wild-type conidia is due to their dihydroxynaphthalene (DHN)-melanin covering the conidia, whereas the hydrophobin RodA rodlet layer plays no role in this process. This is also supported by the observation that pksP conidia still exhibit the RodA hydrophobin layer, as shown by scanning electron microscopy. Mutants defective in different steps of the DHN-melanin biosynthesis showed stronger inhibition than pksP mutant conidia but lower inhibition than wild-type conidia. Moreover, A. fumigatus and A. flavus led to a stronger inhibition of phagolysosomal acidification than A. nidulans and A. terreus. These data indicate that a certain type of DHN-melanin that is different in the various Aspergillus species, is required for maximal inhibition of phagolysosomal acidification. Finally, we identified the vacuolar ATPase (vATPase) as potential target for A. fumigatus based on the finding that addition of bafilomycin which inhibits vATPase, led to complete inhibition of the acidification whereas the fusion of phagosomes containing wild-type conidia and lysosomes was not affected. PMID

  6. Conidial Dihydroxynaphthalene Melanin of the Human Pathogenic Fungus Aspergillus fumigatus Interferes with the Host Endocytosis Pathway.

    PubMed

    Thywißen, Andreas; Heinekamp, Thorsten; Dahse, Hans-Martin; Schmaler-Ripcke, Jeannette; Nietzsche, Sandor; Zipfel, Peter F; Brakhage, Axel A

    2011-01-01

    Aspergillus fumigatus is the most important air-borne fungal pathogen of humans. The interaction of the pathogen with the host's immune system represents a key process to understand pathogenicity. For elimination of invading microorganisms, they need to be efficiently phagocytosed and located in acidified phagolysosomes. However, as shown previously, A. fumigatus is able to manipulate the formation of functional phagolysosomes. Here, we demonstrate that in contrast to pigmentless pksP mutant conidia of A. fumigatus, the gray-green wild-type conidia inhibit the acidification of phagolysosomes of alveolar macrophages, monocyte-derived macrophages, and human neutrophil granulocytes. Therefore, this inhibition is independent of the cell type and applies to the major immune effector cells required for defense against A. fumigatus. Studies with melanin ghosts indicate that the inhibitory effect of wild-type conidia is due to their dihydroxynaphthalene (DHN)-melanin covering the conidia, whereas the hydrophobin RodA rodlet layer plays no role in this process. This is also supported by the observation that pksP conidia still exhibit the RodA hydrophobin layer, as shown by scanning electron microscopy. Mutants defective in different steps of the DHN-melanin biosynthesis showed stronger inhibition than pksP mutant conidia but lower inhibition than wild-type conidia. Moreover, A. fumigatus and A. flavus led to a stronger inhibition of phagolysosomal acidification than A. nidulans and A. terreus. These data indicate that a certain type of DHN-melanin that is different in the various Aspergillus species, is required for maximal inhibition of phagolysosomal acidification. Finally, we identified the vacuolar ATPase (vATPase) as potential target for A. fumigatus based on the finding that addition of bafilomycin which inhibits vATPase, led to complete inhibition of the acidification whereas the fusion of phagosomes containing wild-type conidia and lysosomes was not affected.

  7. Horizontal Transmission of Metarhizium anisopliae in Fruit Flies and Effect of Fungal Infection on Egg Laying and Fertility

    PubMed Central

    Dimbi, Susan; Maniania, Nguya K.; Ekesi, Sunday

    2013-01-01

    Fly-to-fly transmission of conidia of the entomopathogenic fungus Metarhizium anisopliae and the effect of fungal infection on the reproductive potential of females surviving infection were investigated in three fruit fly species, Ceratitis cosyra, C. fasciventris, and C. capitata. The number of conidia picked up by a single fruit fly was determined in C. cosyra. The initial uptake (Day 0) of conidia by a single fly was approx. 1.1 × 106 conidia after exposure to the treated substrate. However, the number of conidia dropped from 7.2 × 105 to 4.1 × 105 conidia after 2 and 8 h post-exposure, respectively. The number of conidia picked up by a single fungus-treated fly (“donor”) varied between 3.8 × 105 and 1.0 × 106 in the three fruit fly species, resulting in 100% mortality 5–6 days post-exposure. When fungus-free flies of both sexes (“recipient” flies) were allowed to mate with “donor” flies, the number of conidia picked up by a single fly varied between 1.0 × 105 and 2.5 × 105, resulting in a mortality of 83–100% in C. capitata, 72–85% in C. cosyra and 71–93% in C. fasciventris 10–15 days post-inoculation. There was an effect of fungal infection on female egg laying in the three species of fruit flies as control flies laid more eggs than fungus-treated females. The percentage reduction in fecundity in flies infected with M. anisopliae was 82, 73 and 37% in C. capitata, C. fasciventris and C. cosyra, respectively. The results are discussed with regard to application in autodissemination techniques. PMID:26464386

  8. Germination-defective mutant of Neurospora crassa that responds to siderophores

    NASA Technical Reports Server (NTRS)

    Charlang, G.; Williams, N. P.

    1977-01-01

    A conditionally germination-defective mutant of Neurospora crassa has been found to be partially curable by ferricrocin and other siderophores. The mutant conidia rapidly lose their membrane-bound siderophores when suspended in buffer or growth media. Germination is consequently delayed unless large numbers of conidia are present (positive population effect). This indicates that the mutant has a membrane defect involving the siderophore attachment site.

  9. [Inhibition of Bacillus pumilus AR03 on Alternaria alternata and Erysiphe cichoracearum on tobacco].

    PubMed

    Wang, Jing; Tian, Hua; Kong, Fan-yu; Wang, Yi-hong; Zhang, Cheng-sheng; Feng, Chao

    2015-10-01

    This study aimed to evaluate the efficiency of Bacillus pumilus AR03 against Altenaria alternata and Erysiphe cichoracearum. The antagonistic activities were studied in the way of co-culture on plate, inhibition of pathogen conidia germination on concave slides and LB agar medium. In the investigation, the water suspension of living cells of strain AR03, at 3 x 10(8) cfu . mL-1 had a remarkable inhibition effect on hyphae growth and conidia germination of A. alternata and caused hyphae deformation, shorter and swollen nodes, winding hyphae accumulation, abnormal tubes with tips expanded or deformed. Conidia did not germinate and the tissues of compartment became swollen or formed a round spherical bubble. In addition, the inhibition rate of conidia germination of E. cichoracearum was 91. 3% and 69. 3%, respectively when treated with strain AR03 at 1 x 10(7) cfu . mL-1 and 1.5 x 10(6) cfu . mL-1. Conidia treated by living cells of AR03 became swollen, deformed, the protoplasm of conidia shrinked, disintegrated gradually and separated from the conidia wall. And some conidia were hollow because the protoplasm leaked out from inside. Greenhouse results revealed that the effects of living cells of AR03 with different concentrations were significantly different. Bacterial suspension of AR03 at 3 x 10(8) cfu . mL-1 was strongly antagonistic to E. cichoracearum with the control efficiencies 7 days and 15 days after treatment of two spays being 83.8% and 90.3%, respectively, while the control efficiencies of AR03 at 3 x 10(6) cfu . mL-1 were 70.0% and 73.3%, respectively. Strain AR03 had a long persistence against powdery mildew more than 30 days.

  10. Effect of storage conditions (relative humidity, duration, and temperature) on the germination time of Aspergillus carbonarius and Penicillium chrysogenum.

    PubMed

    Lattab, Nadia; Kalai, Safaa; Bensoussan, Maurice; Dantigny, Philippe

    2012-11-01

    Fungal conidia are disseminated, often in the air, for a certain period of time, prior to contaminating food products. The objective of this study was to examine the effects of the relative humidity, RH (%), time (day), and temperature (°C) during this period of time, called "storage", on the germination time, τ (h), of Aspergillus carbonarius and Penicillium chrysogenum. A Doehlert design was used in the range, 20-100% RH, 2-28 days, and 5-25 °C. As compared to un-stored conidia, the germination time of conidia stored at 60% RH, 15 days, 5 °C was increased by 23 and 28%, for A. carbonarius and P. chrysogenum, respectively. Stored conidia exhibited a minimum τ value at 60% RH, and 100% RH for A. carbonarius and P. chrysogenum, respectively. For these species, τ was minimum for 2 days of storage. The effect of temperature was RH dependent for A. carbonarius. The germination time of stored conidia was clearly greater than that of fresh conidia obtained in the laboratory. This result should be taken into account to determine the mould free shelf-life of food products.

  11. Antifungal properties of wheat histones (H1-H4) and purified wheat histone H1.

    PubMed

    De Lucca, Anthony J; Heden, Lars-Olof; Ingber, Bruce; Bhatnagar, Deepak

    2011-07-13

    Wheat ( Triticum spp.) histones H1, H2, H3, and H4 were extracted, and H1 was further purified. The effect of these histones on specific fungi that may or may not be pathogenic to wheat was determined. These fungi included Aspergillus flavus , Aspergillus fumigatus , Aspergillus niger , Fusarium oxysporum , Fusarium verticillioides , Fusarium solani , Fusarium graminearum , Penicillium digitatum , Penicillium italicum , and Greeneria uvicola . Non-germinated and germinating conidia of these fungi were bioassayed separately. The non-germinated and germinating conidia of all Fusarium species were highly susceptible to the mixture (H1-H4) as well as pure H1, with viability losses of 99-100% found to be significant (p < 0.001) at ≤10 μM or less for the histone mixture and pure H1. F. graminearum was the most sensitive to histone activity. The histones were inactive against all of the non-germinated Penicillium spp. conidia. However, they significantly reduced the viability of the germinating conidia of the Penicillium spp. conidia, with 95% loss at 2.5 μM. Non-germinated and germinating conidia viability of the Aspergillus spp. and G. uvicola were unaffected when exposed to histones up to 10 μM. Results indicate that Fusarium spp. pathogenic to wheat are susceptible to wheat histones, indicating that these proteins may be a resistance mechanism in wheat against fungal infection.

  12. Population genetics of the aquatic fungus Tetracladium marchalianum over space and time.

    PubMed

    Anderson, Jennifer L; Shearer, Carol A

    2011-01-14

    Aquatic hyphomycete fungi are fundamental mediators of energy flow and nutrient spiraling in rivers. These microscopic fungi are primarily dispersed in river currents, undergo substantial annual fluctuations in abundance, and reproduce either predominantly or exclusively asexually. These aspects of aquatic hyphomycete biology are expected to influence levels and distributions of genetic diversity over both spatial and temporal scales. In this study, we investigated the spatiotemporal distribution of genotypic diversity in the representative aquatic hyphomycete Tetracladium marchalianum. We sampled populations of this fungus from seven sites, three sites each in two rivers in Illinois, USA, and one site in a Wisconsin river, USA, and repeatedly sampled one population over two years to track population genetic parameters through two seasonal cycles. The resulting fungal isolates (N = 391) were genotyped at eight polymorphic microsatellite loci. In spite of seasonal reductions in the abundance of this species, genotypic diversity was consistently very high and allele frequencies remarkably stable over time. Likewise, genotypic diversity was very high at all sites. Genetic differentiation was only observed between the most distant rivers (∼450 km). Clear evidence that T. marchalianum reproduces sexually in nature was not observed. Additionally, we used phylogenetic analysis of partial β-tubulin gene sequences to confirm that the fungal isolates studied here represent a single species. These results suggest that populations of T. marchalianum may be very large and highly connected at local scales. We speculate that large population sizes and colonization of alternate substrates in both terrestrial and aquatic environments may effectively buffer the aquatic populations from in-stream population fluctuations and facilitate stability in allele frequencies over time. These data also suggest that overland dispersal is more important for structuring populations of T

  13. Xylohypha emmonsii sp. nov., a new agent of phaeohyphomycosis.

    PubMed Central

    Padhye, A A; McGinnis, M R; Ajello, L; Chandler, F W

    1988-01-01

    Xylohypha emmonsii Padhye, McGinnis et Ajello is described as a new dematiaceous opportunistic pathogen of humans and lower animals. This hyphomycete differs from X. bantiana (Saccardo) McGinnis, Padhye, Borelli et Ajello by its inability to grow at 40 degrees C and by the development of short chains of asymmetrically bent to ellipsoid blastoconidia. In brain tissue of mice, experimentally infected with X. emmonsii, the host response to the invading fungus was similar to that observed in mice infected with X. bantiana. In tissues X. bantiana occurred predominantly as long, septate hyphae, in contrast to X. emmonsii, which was more polymorphic. Images PMID:3366865

  14. Inactivation of Aspergillus niger in mango nectar by high-pressure homogenization combined with heat shock.

    PubMed

    Tribst, Alline A L; Franchi, Mark A; Cristianini, Marcelo; de Massaguer, Pilar R

    2009-01-01

    This research evaluated the inactivation of a heat-resistant Aspergillus niger conidia in mango nectar by high-pressure homogenization (HPH) combined with heat shock. A. niger were inoculated in mango nectar (10(6) conidia mL(-1)) and subjected to HPH (300 to 100 MPa) and heat shock (80 degrees C for 5 to 20 min) before or after HPH. Processes were evaluated according to number of decimal reductions reached by each isolated or combined process. Scanning electron microscopy was performed to observe conidia wall after pressure treatment. Pressures below 150 MPa did not inactivate A. niger while pressures of 200 and 300 MPa resulted in 2 and more than 6 log reductions, respectively. D(80 degrees C) of A. niger was determined as 5.03 min. A heat shock of 80 degrees C/15 min, reaching 3 decimal conidia reductions, was applied before or after a 200 MPa pressure treatment to improve the decimal reduction to 5 log cycles. Results indicated that HPH inactivated A. niger in mango nectar at 300 MPa (>6.24 log cycles) and that, with pressure (200 MPa) combined with post heat shock, it was possible to obtain the same decimal reduction, showing a synergistic effect. On the other hand, pre heat shock associated with HPH resulted in an additive effect. The observation of A. niger conidia treated by HPH at 100 and 200 MPa by scanning electron microscopy indicated that HPH promoted intense cell wall damage, which can sensitize the conidia to post heat shock and possibly explain the synergistic effect observed. Practical Application: The results obtained in this paper are relevant to elucidate the mechanism of conidia inactivation in order to develop the application of HPH as an alternative pasteurization process for the fruit nectar industry.

  15. Bioassay and Scanning Electron Microscopic Observations Reveal High Virulence of Entomopathogenic Fungus, Beauveria bassiana, on the Onion Maggot (Diptera: Anthomyiidae) Adults.

    PubMed

    Zhang, Hui; Wu, Shengyong; Xing, Zhenlong; Wang, Xiaoqing; Lei, Zhongren

    2016-12-01

    When flies were dipped in 1 × 10(8) conidia/ml conidia suspensions and then kept in the incubator (22 ± 1 °C, 70 ± 5% RH), scanning electron microscope observations revealed that, at 2 h, the majority of adhering Beauveria bassiana conidia were attached to either the wing surface or the interstitial area between the macrochaetae on the thorax and abdomen of the onion maggot adults. Germ tubes were being produced and had oriented toward the cuticle by 18 h. Penetration of the insect cuticle had occurred by 36 h, and by 48 h, germ tubes had completely penetrated the cuticle. Fungal mycelia had emerged from the insect body and were proliferating after 72 h. The superficial area and structure of the wings and macrochaetae may facilitate the attachment of conidia and enable effective penetration. The susceptibility of adults to 12 isolates, at a concentration of 1 × 10(7) conidia/ml, was tested in laboratory experiments. Eight of the more potent strains caused in excess of 85% adult mortality 8 d post inoculation, while the median lethal time (LT50) of these strains was <6 d. The virulence of the more effective strains was further tested, and the median lethal concentrations (LC50) were calculated by exposing adults to doses ranging from 10(3)-10(7) conidia/ml. The lowest LC50 value, found in the isolate XJWLMQ-32, for the adults was 3.87 × 10(3) conidia/ml. These results demonstrate that some B. bassiana strains are highly virulent to onion maggot adults and should be considered as potential biocontrol agents against the adult flies.

  16. Tools for delivering entomopathogenic fungi to malaria mosquitoes: effects of delivery surfaces on fungal efficacy and persistence

    PubMed Central

    2010-01-01

    Background Entomopathogenic fungi infection on malaria vectors increases daily mortality rates and thus represents a control measure that could be used in integrated programmes alongside insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS). Before entomopathogenic fungi can be integrated into control programmes, an effective delivery system must be developed. Methods The efficacy of Metarhizium anisopliae ICIPE-30 and Beauveria bassiana I93-825 (IMI 391510) (2 × 1010 conidia m-2) applied on mud panels (simulating walls of traditional Tanzanian houses), black cotton cloth and polyester netting was evaluated against adult Anopheles gambiae sensu stricto. Mosquitoes were exposed to the treated surfaces 2, 14 and 28 d after conidia were applied. Survival of mosquitoes was monitored daily. Results All fungal treatments caused a significantly increased mortality in the exposed mosquitoes, descending with time since fungal application. Mosquitoes exposed to M. anisopliae conidia on mud panels had a greater daily risk of dying compared to those exposed to conidia on either netting or cotton cloth (p < 0.001). Mosquitoes exposed to B. bassiana conidia on mud panels or cotton cloth had similar daily risk of death (p = 0.14), and a higher risk than those exposed to treated polyester netting (p < 0.001). Residual activity of fungi declined over time; however, conidia remained pathogenic at 28 d post application, and were able to infect and kill 73 - 82% of mosquitoes within 14 d. Conclusion Both fungal isolates reduced mosquito survival on immediate exposure and up to 28 d after application. Conidia were more effective when applied on mud panels and cotton cloth compared with polyester netting. Cotton cloth and mud, therefore, represent potential substrates for delivering fungi to mosquitoes in the field. PMID:20799967

  17. Synthesis of melanin-like pigments by Sporothrix schenckii in vitro and during mammalian infection.

    PubMed

    Morris-Jones, Rachael; Youngchim, Sirida; Gomez, Beatriz L; Aisen, Phil; Hay, Roderick J; Nosanchuk, Joshua D; Casadevall, Arturo; Hamilton, Andrew J

    2003-07-01

    Melanin has been implicated in the pathogenesis of several important human fungal pathogens. Existing data suggest that the conidia of the dimorphic fungal pathogen Sporothrix schenckii produce melanin or melanin-like compounds; in this study we aimed to confirm this suggestion and to demonstrate in vitro and in vivo production of melanin by yeast cells. S. schenckii grown on Mycosel agar produced visibly pigmented conidia, although yeast cells grown in brain heart infusion and minimal medium broth appeared to be nonpigmented macroscopically. However, treatment of both conidia and yeast cells with proteolytic enzymes, denaturant, and concentrated hot acid yielded dark particles similar in shape and size to the corresponding propagules, which were stable free radicals consistent with identification as melanins. Melanin particles extracted from S. schenckii yeast cells were used to produce a panel of murine monoclonal antibodies (MAbs) which labeled pigmented conidia, yeast cells, and the isolated particles. Tissue from hamster testicles infected with S. schenckii contained fungal cells that were labeled by melanin-binding MAbs, and digestion of infected hamster tissue yielded dark particles that were also reactive. Additionally, sera from humans with sporotrichosis contained antibodies that bound melanin particles. These findings indicate that S. schenckii conidia and yeast cells can produce melanin or melanin-like compounds in vitro and that yeast cells can synthesize pigment in vivo. Since melanin is an important virulence factor in other pathogenic fungi, this pigment may have a similar role in the pathogenesis of sporotrichosis.

  18. Synthesis of Melanin-Like Pigments by Sporothrix schenckii In Vitro and during Mammalian Infection

    PubMed Central

    Morris-Jones, Rachael; Youngchim, Sirida; Gomez, Beatriz L.; Aisen, Phil; Hay, Roderick J.; Nosanchuk, Joshua D.; Casadevall, Arturo; Hamilton, Andrew J.

    2003-01-01

    Melanin has been implicated in the pathogenesis of several important human fungal pathogens. Existing data suggest that the conidia of the dimorphic fungal pathogen Sporothrix schenckii produce melanin or melanin-like compounds; in this study we aimed to confirm this suggestion and to demonstrate in vitro and in vivo production of melanin by yeast cells. S. schenckii grown on Mycosel agar produced visibly pigmented conidia, although yeast cells grown in brain heart infusion and minimal medium broth appeared to be nonpigmented macroscopically. However, treatment of both conidia and yeast cells with proteolytic enzymes, denaturant, and concentrated hot acid yielded dark particles similar in shape and size to the corresponding propagules, which were stable free radicals consistent with identification as melanins. Melanin particles extracted from S. schenckii yeast cells were used to produce a panel of murine monoclonal antibodies (MAbs) which labeled pigmented conidia, yeast cells, and the isolated particles. Tissue from hamster testicles infected with S. schenckii contained fungal cells that were labeled by melanin-binding MAbs, and digestion of infected hamster tissue yielded dark particles that were also reactive. Additionally, sera from humans with sporotrichosis contained antibodies that bound melanin particles. These findings indicate that S. schenckii conidia and yeast cells can produce melanin or melanin-like compounds in vitro and that yeast cells can synthesize pigment in vivo. Since melanin is an important virulence factor in other pathogenic fungi, this pigment may have a similar role in the pathogenesis of sporotrichosis. PMID:12819091

  19. Virulence of Entomopathogenic Fungi Metarhizium anisopliae and Paecilomyces fumosoroseus for the Microbial Control of Spodoptera exigua

    PubMed Central

    Han, Ji Hee; Jin, Byung Rae; Lee, Sang Yeob

    2014-01-01

    The beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) is difficult to control using chemical insecticides because of the development of insecticide resistance. Several pest control agents are used to control the beet armyworm. Entomopathogenic fungi are one of the candidates for eco-friendly pest control instead of chemical control agents. In this study, among various entomopathogenic fungal strains isolated from soil two isolates were selected as high virulence pathogens against larva of beet armyworm. Control efficacy of fungal conidia was influenced by conidia concentration, temperature, and relative humidity (RH). The isolates Metarhizium anisopliae FT83 showed 100% cumulative mortality against second instar larvae of S. exigua 3 days after treatment at 1 × 107 conidia/mL and Paecilomyces fumosoroseus FG340 caused 100% mortality 6 days after treatment at 1 × 104 conidia/mL. Both M. anisopliae FT83 and P. fumosoroseus FG340 effectively controlled the moth at 20~30℃. M. anisopliae FT83 was significantly affected mortality by RH: mortality was 86.7% at 85% RH and 13.4% at 45% RH. P. fumosoroseus FG340 showed high mortality as 90% at 45% RH and 100% at 75% RH 6 days after conidia treatments. These results suggest that P. fumosoroseus FG340 and M. anisopliae FT83 have high potential to develop as a biocontrol agent against the beet armyworm. PMID:25606011

  20. Virulence of a variant of Paracoccidioides brasiliensis that exists in the yeast form at room temperature.

    PubMed

    Villar, L A; Restrepo, A

    1989-01-01

    Paracoccidioides brasiliensis (ATCC 60885) produces conidia that, when plated in enriched media and incubated at 21-25 degrees C, give rise to a yeast-form variant (YRT) (ATCC 46678). The virulence of this variant for BALB/c mice has been compared with that of the yeast and conidia produced by the parent isolate. Adult female mice were inoculated intravenously with 10(7) viable cells of YRT or yeast, or 5 x 10(5) viable conidia. Mice were weighed weekly, and three mice were sacrificed at 1, 2, 3, 4 and 8 weeks post-inoculation and their organs weighed and prepared for determination of viable counts (colony forming units; c.f.u.). Animals infected with yeast cells or with conidia exhibited little weight loss in comparison with that seen in the YRT-infected mice which began to lose weight 1 week post-challenge. Organ weights increased in the YRT group, while the changes in the remaining two groups were minor. The c.f.u. from these organs also increased in the YRT-infected mice, whereas the infection in the yeast-and conidia-infected mice was self-limiting. A proportion (16.6%) of the YRT-infected animals died during the observation period. Conversely, no deaths occurred in the remaining groups. These results indicate that the YRT variant possesses increased virulence.

  1. Monitoring environmental Aspergillus spp. contamination and meteorological factors in a haematological unit.

    PubMed

    Cavallo, M; Andreoni, S; Martinotti, M G; Rinaldi, M; Fracchia, L

    2013-12-01

    The opportunistic pathogens belonging to the Aspergillus genus are present in almost all seasons of the year, and their concentration is related to meteorological conditions. The high density of Aspergillus spp. conidia in a haematological hospital ward may be a significant risk factor for developing invasive fungal diseases in immunocompromised patients. Aim of the present study was to evaluate the variability of airborne Aspergillus spp. conidia contamination in a Haematological Unit (HU) within a period of 16 months in relation with some meteorological parameters. An environmental Aspergillus surveillance was conducted in the HU in four rooms and their bathrooms, in the corridor and in three external sites using an agar impact sampler. During each sampling, temperature and relative humidity at each site were recorded and current wind speed and rainfall events were taken from the official weather service. Aspergillus spp. conidia concentration differed significantly across the sampling sites. Internal Aspergillus spp. loads were significantly dependent on temperature, internal relative humidity and rain. External conidia concentrations were significantly influenced by outdoor temperature and relative humidity. A suitable indicator was introduced to evaluate the seasonal distribution of Aspergillus spp. conidia in the sampling sites, and a significant dependence on this indicator was observed inside the HU. Seventeen different fungal species belonging to the Aspergillus genus were detected during the sampling period. Aspergillus fumigatus was the most frequently isolated species and its distribution depended significantly on the seasonal indicator both inside and outside the hospital ward.

  2. Agent-based modeling approach of immune defense against spores of opportunistic human pathogenic fungi.

    PubMed

    Tokarski, Christian; Hummert, Sabine; Mech, Franziska; Figge, Marc Thilo; Germerodt, Sebastian; Schroeter, Anja; Schuster, Stefan

    2012-01-01

    Opportunistic human pathogenic fungi like the ubiquitous fungus Aspergillus fumigatus are a major threat to immunocompromised patients. An impaired immune system renders the body vulnerable to invasive mycoses that often lead to the death of the patient. While the number of immunocompromised patients is rising with medical progress, the process, and dynamics of defense against invaded and ready to germinate fungal conidia are still insufficiently understood. Besides macrophages, neutrophil granulocytes form an important line of defense in that they clear conidia. Live imaging shows the interaction of those phagocytes and conidia as a dynamic process of touching, dragging, and phagocytosis. To unravel strategies of phagocytes on the hunt for conidia an agent-based modeling approach is used, implemented in NetLogo. Different modes of movement of phagocytes are tested regarding their clearing efficiency: random walk, short-term persistence in their recent direction, chemotaxis of chemokines excreted by conidia, and communication between phagocytes. While the short-term persistence hunting strategy turned out to be superior to the simple random walk, following a gradient of chemokines released by conidial agents is even better. The advantage of communication between neutrophilic agents showed a strong dependency on the spatial scale of the focused area and the distribution of the pathogens.

  3. A rapid knockdown effect of Penicillium citrinum for control of the mosquito Culex quinquefasciatus in Thailand.

    PubMed

    Maketon, Monchan; Amnuaykanjanasin, Alongkorn; Kaysorngup, Achirayar

    2014-02-01

    Twenty local isolates of entomopathogenic fungi were determined for control of the larvae and adults of Culex quinquefasciatus. In a laboratory experiment, a Penicillium sp. CM-010 caused 100% mortality of third-instar larvae within 2 h using a conidial suspension of 1 × 10⁶ conidia ml⁻¹. Its LC₅₀ was 3 × 10⁵ conidia ml⁻¹, and the lethal time (LT₅₀) was 1.06 h. Cloning and sequencing of its internal transcribed spacer region indicated that this Penicillium species is Penicillium citrinum (100% identity in 434 bp). Mortality of the adult was highest with Aspergillus flavus CM-011 followed with Metarhizium anisopliae CKM-048 from 1 × 10⁹ conidia ml⁻¹. P. citrinum CM-010 at 1 × 10⁶ conidia ml⁻¹ killed 100% larvae within 2 h while Bacillus thuringiensis var. israelensis at 5 ITU ml⁻¹ required 24 h. This P. citrinum CM-010 also greatly reduced survival of C. quinquefasciatus larvae in an unreplicated field test. Light and transmission electron micrographs showed that the fungal conidia were ingested by the larvae and deposited in the gut. The metabolite patulin was produced by P. citrinum CM-010 instead of citrinin.

  4. Ethanol and phenanthrene increase the biomass of fungal assemblages and decrease plant litter decomposition in streams.

    PubMed

    Barros, Diana; Oliveira, Patrícia; Pascoal, Cláudia; Cássio, Fernanda

    2016-09-15

    Fungi, particularly aquatic hyphomycetes, have been recognized as playing a dominant role in microbial decomposition of plant litter in streams. In this study, we used a microcosm experiment with different levels of fungal diversity (species number and identity) using monocultures and combinations with up to five aquatic hyphomycete species (Articulospora tetracladia, Tricladium splendens, Heliscus submersus, Tetrachaetum elegans and Flagellospora curta) to assess the effects of ethanol and phenanthrene on three functional measures: plant litter decomposition, fungal biomass accrual and reproduction. Alder leaves were conditioned by fungi for 7days and then were exposed to phenanthrene (1mgL(-1)) dissolved in ethanol (0.1% final concentration) or ethanol (at the concentration used to solubilise phenanthrene) for further 24days. Exposure to ethanol alone or in combination with phenanthrene decreased leaf decomposition and fungal reproduction, but increased fungal biomass produced. All aspects of fungal activity varied with species number. Fungal activity in polycultures was generally higher than that expected from the sum of the weighted performances of participating species in monoculture, suggesting complementarity between species. However, the activity of fungi in polycultures did not exceed the activity of the most productive species either in the absence or presence of ethanol alone or with phenanthrene.

  5. Alteration of protein patterns in black rock inhabiting fungi as a response to different temperatures

    PubMed Central

    Tesei, Donatella; Marzban, Gorji; Zakharova, Kristina; Isola, Daniela; Selbmann, Laura; Sterflinger, Katja

    2012-01-01

    Rock inhabiting fungi are among the most stress tolerant organisms on Earth. They are able to cope with different stressors determined by the typical conditions of bare rocks in hot and cold extreme environments. In this study first results of a system biological approach based on two-dimensional protein profiles are presented. Protein patterns of extremotolerant black fungi – Coniosporium perforans, Exophiala jeanselmei – and of the extremophilic fungus – Friedmanniomyces endolithicus – were compared with the cosmopolitan and mesophilic hyphomycete Penicillium chrysogenum in order to follow and determine changes in the expression pattern under different temperatures. The 2D protein gels indicated a temperature dependent qualitative change in all the tested strains. Whereas the reference strain P. chrysogenum expressed the highest number of proteins at 40 °C, thus exhibiting real signs of temperature induced reaction, black fungi, when exposed to temperatures far above their growth optimum, decreased the number of proteins indicating a down-regulation of their metabolism. Temperature of 1 °C led to an increased number of proteins in all of the analysed strains, with the exception of P. chrysogenum. These first results on temperature dependent reactions in rock inhabiting black fungi indicate a rather different strategy to cope with non-optimal temperature than in the mesophilic hyphomycete P. chrysogenum. PMID:22862921

  6. Fungi and bacteria involved in desert varnish formation

    NASA Technical Reports Server (NTRS)

    Taylor-George, S.; Palmer, F.; Staley, J. T.; Curtiss, B.; Adams, J. B.; Borns, D. J.

    1983-01-01

    Desert varnish is a coating of ferromanganese oxides and clays that develops on rock surfaces in arid to semi-arid regions. Active respiration but not photosynthesis was detected on varnished rock surfaces from the Sonoran Desert. Light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations, and cultivation experiments indicate that both fungi, primarily dematiaceous hyphomycetes, and bacteria are found on and within desert varnish coatings from the arid regions studied. Some fungi grow as microcolonial fungi (MCF) on rocks, and microscopic observations suggest MCF become incorporated in the varnish coating. SEM-EDAX (energy dispersive X-ray systems) analyses indicate the MCF contain 3 of the characteristic elements of varnish: iron, aluminum, and silicon. In some locations, MCF are also enriched in manganese relative to the rock substratum. Furthermore, some of the dematiaceous hyphomycetes that have been cultivated are able to oxidize manganese under laboratory conditions. It is possible that manganese-oxidizing bacteria, which are found in varnish, also play an important role in varnish formation.

  7. Alteration of protein patterns in black rock inhabiting fungi as a response to different temperatures.

    PubMed

    Tesei, Donatella; Marzban, Gorji; Zakharova, Kristina; Isola, Daniela; Selbmann, Laura; Sterflinger, Katja

    2012-08-01

    Rock inhabiting fungi are among the most stress tolerant organisms on Earth. They are able to cope with different stressors determined by the typical conditions of bare rocks in hot and cold extreme environments. In this study first results of a system biological approach based on two-dimensional protein profiles are presented. Protein patterns of extremotolerant black fungi -Coniosporium perforans, Exophiala jeanselmei - and of the extremophilic fungus -Friedmanniomyces endolithicus - were compared with the cosmopolitan and mesophilic hyphomycete Penicillium chrysogenum in order to follow and determine changes in the expression pattern under different temperatures. The 2D protein gels indicated a temperature dependent qualitative change in all the tested strains. Whereas the reference strain P. chrysogenum expressed the highest number of proteins at 40 °C, thus exhibiting real signs of temperature induced reaction, black fungi, when exposed to temperatures far above their growth optimum, decreased the number of proteins indicating a down-regulation of their metabolism. Temperature of 1 °C led to an increased number of proteins in all of the analysed strains, with the exception of P. chrysogenum. These first results on temperature dependent reactions in rock inhabiting black fungi indicate a rather different strategy to cope with non-optimal temperature than in the mesophilic hyphomycete P. chrysogenum.

  8. Pathogenicity and ultrastructural studies of the mode of penetration by Phoma strasseri in peppermint stems and rhizomes.

    PubMed

    Zimowska, Beata

    2012-01-01

    Pathogenicity and ultrastructural investigation of the inoculation of peppermint stems and rhizomes with Phoma strasseri conidia was undertaken using scanning and transmission electron microscopy to examine the host-parasite relationship. Pathogenicity experiments demonstrated that all tested P. strasseri isolates had infected the stems and rhizomes of peppermint. Of all inoculation methods, direct placement of colonized agar plugs on damaged epidermis and soaking stems and rhizomes in conidial suspension were the most effective. The behavior of the conidia deposited on the stems and rhizomes was investigated at different time intervals after inoculation: 6, 16, 24, 36 and 48 h. Conidia produced an appressorium directly at the end of a short germ tube. Appressoria were formed over the cuticle, but never over stomata. Direct penetration to host tissue through the cuticle was observed. The spore and hyphae were covered with a mucilaginous sheath.

  9. Identification and functional analysis of endogenous nitric oxide in a filamentous fungus

    PubMed Central

    Pengkit, Anchalee; Jeon, Seong Sil; Son, Soo Ji; Shin, Jae Ho; Baik, Ku Yeon; Choi, Eun Ha; Park, Gyungsoon

    2016-01-01

    In spite of its prevalence in animals and plants, endogenous nitric oxide (NO) has been rarely reported in fungi. We present here our observations on production of intracellular NO and its possible roles during development of Neurospora crassa, a model filamentous fungus. Intracellular NO was detected in hypha 8–16 hours after incubation in Vogel’s minimal liquid media and conidiophores during conidiation using a fluorescent indicator (DAF-FM diacetate). Treatment with cPTIO, an NO scavenger, significantly reduced fluorescence levels and hindered hyphal growth in liquid media and conidiation, whereas exogenous NO enhanced hyphal extension on VM agar media and conidia formation. NO scavenging also dramatically diminished transcription of con-10 and con-13, genes preferentially expressed during conidiation. Our results suggest that intracellular NO is generated in young hypha growing in submerged culture and during conidia development and regulate mycelial development and conidia formation. PMID:27425220

  10. Ulocladium cantlous sp. nov. isolated from northwestern China: its morphology and molecular phylogenetic position.

    PubMed

    Wang, Yong; Pei, Yun-Fei; O'Neill, Nichole R; Zhang, Xiu-Guo

    2010-01-01

    A new species of Ulocladium was isolated from diseased leaves from two Cucumis sp. growing in Sinkiang and Gansu provinces of China. Conidia were isolated from necrotic leaves and used to establish single-spore pure cultures. Conidia were harvested from cultures 7 d after incubation for morphological comparisons. The morphology of this species resembles that of U. botrytis and U. consortiale. However it is distinguished from these two species by the sizes of obovoid to broadly ellipsoidal conidia and longer conidiophores. A taxonomic description of U. cantlous, comparison with related species in this genus, and a species phylogeny based on the partial nucleotide sequence of the glyceraldehyde-3-phosphate dehydrogenase (gpd) gene and the Alternaria alternata major allergen (Alt a 1) gene are provided.

  11. Rhinofacial conidiobolomycosis caused by Conidiobolus coronatus in a Chinese rice farmer.

    PubMed

    Yang, Xiumin; Li, Yadi; Zhou, Xiaoqian; Wang, Yuxin; Geng, Suying; Liu, Honggang; Yang, Qingwen; Lu, Xinxin; Hiruma, Masataro; Sugita, Takashi; Ikeda, Shigaku; Ogawa, Hideoki

    2010-07-01

    We provide the first report of rhinofacial conidiobolomycosis caused by Conidiobolus coronatus in China. The patient was a 36-year-old male rice farmer from Jiang Xi province who presented with diffuse swelling with classical centrofacial distribution and involvement of the right paranasal sinuses. Histopathology showed granulomas with hyphae surrounded by an eosinophilic sheath (Splendore-Hoeppli phenomenon). Culture of biopsy specimens on Sabouraud's dextrose agar led to the growth of fungi with microscopically visible conidiophores and terminal spherical conidia (primary conidium), with multiple secondary conidia and villose conidia. The patient was successfully treated with combination therapy, primarily itraconazole and terbinafine. We conclude with a brief literature review of the epidemiology of conidiobolomycosis.

  12. In vitro activity of Melaleuca alternifolia (tea tree) oil against dermatophytes and other filamentous fungi.

    PubMed

    Hammer, K A; Carson, C F; Riley, T V

    2002-08-01

    The in vitro activity of Melaleuca alternifolia (tea tree) oil against dermatophytes (n = 106) and filamentous fungi (n = 78) was determined. Tea tree oil MICs for all fungi ranged from 0.004% to 0.25% and minimum fungicidal concentrations (MFCs) ranged from <0.03% to 8.0%. Time-kill experiments with 1-4 x MFC demonstrated that three of the four test organisms were still detected after 8 h of treatment, but not after 24 h. Comparison of the susceptibility to tea tree oil of germinated and non-germinated Aspergillus niger conidia showed germinated conidia to be more susceptible than non-germinated conidia. These data demonstrate that tea tree oil has both inhibitory and fungicidal activity.

  13. Growth substrates and caleosin-mediated functions affect conidial virulence in the insect pathogenic fungus Beauveria bassiana.

    PubMed

    Ortiz-Urquiza, Almudena; Fan, Yanhua; Garrett, Timothy; Keyhani, Nemat O

    2016-11-01

    The entomopathogenic fungus, Beauveria bassiana, is a microbial biological control agent capable of infecting a wide range of insect hosts. Conidia (spores) initiate infection via adhesion, growth and penetration of the insect cuticle, whose outmost layer is rich in lipids. Conidial virulence was investigated in B. bassiana WT and caleosin mutants (ΔBbcal1), the latter a protein involved in lipid storage and turnover. Topical insect bioassays revealed that conidia of the WT strain showed up to 40-fold differences in LD50 values depending upon the growth substrate. The most virulent conidia were harvested from potato dextrose agar containing oleic acid, and the least potent were those derived from Sabouraud dextrose/yeast extract agar (SDAY). However, with the exception of conidia derived from SDAY and Czapek Dox agar, in which values were reduced, mean lethal times to kill (LT50) were essentially unaffected. In topical bioassays, the ΔBbcal1 mutant displayed LD50 values 5-40-fold higher than the WT depending upon the growth substrate, with ΔBbcal1 conidia derived from SDAY unable to effectively penetrate the host cuticle. The ΔBbcal1 mutant also showed concomitant dramatic increases in LT50 values from a mean of ~4.5 for WT to >8.5 days for the mutant. In contrast, intrahaemocoel injection bioassays that bypass cuticle penetration events revealed only minor effects on virulence for either WT or ΔBbcal1 conidia. These data highlight the importance of caleosin-dependent lipid mobilization and/or signalling in cuticle penetration events but suggest their dispensability for immune evasion and within-host growth.

  14. N-Chlorotaurine Exhibits Fungicidal Activity against Therapy-Refractory Scedosporium Species and Lomentospora prolificans

    PubMed Central

    Lackner, Michaela; Binder, Ulrike; Reindl, Martin; Gönül, Beyhan; Fankhauser, Hannes; Mair, Christian

    2015-01-01

    N-Chlorotaurine (NCT), a well-tolerated endogenous long-lived oxidant that can be applied topically as an antiseptic, was tested on its fungicidal activity against Scedosporium and Lomentospora, opportunistic fungi that cause severe infections with limited treatment options, mainly in immunocompromised patients. In quantitative killing assays, both hyphae and conidia of Scedosporium apiospermum, Scedosporium boydii, and Lomentospora prolificans (formerly Scedosporium prolificans) were killed by 55 mM (1.0%) NCT at pH 7.1 and 37°C, with a 1- to 4-log10 reduction in CFU after 4 h and a 4- to >6-log10 reduction after 24 h. The addition of ammonium chloride to NCT markedly increased this activity. LIVE/DEAD staining of conidia treated with 1.0% NCT for 0.5 to 3 h increased the permeability of the cell wall and membrane. Preincubation of the test fungi in 1.0% NCT for 10 to 60 min delayed the time to germination of conidia by 2 h to >12 h and reduced their germination rate by 10.0 to 100.0%. Larvae of Galleria mellonella infected with 1.0 × 107 conidia of S. apiospermum and S. boydii died at a rate of 90.0 to 100% after 8 to 12 days. The mortality rate was reduced to 20 to 50.0% if conidia were preincubated in 1.0% NCT for 0.5 h or if heat-inactivated conidia were used. Our study demonstrates the fungicidal activity of NCT against different Scedosporium and Lomentospora species. A postantifungal effect connected with a loss of virulence occurs after sublethal incubation times. The augmenting effect of ammonium chloride can be explained by the formation of monochloramine. PMID:26239996

  15. Efficacy of Trichoderma asperellum oil formulations on the control of cocoa black pod disease (Phytophthora megakarya).

    PubMed

    Mbarga, J B; Ten Hoopen, G Martijn; Begoude, A D; Tondje, P R; Kuate, J; Ambang, Z; Amougou, A; Schiffers, B

    2012-01-01

    The objective of this study was therefore to develop a formulation of conidia of T. asperellum with the aim of improving its efficacy. The formulations developed were oily dispersions. It was a combination of solvents consisting of groundnut oil or palm oil with structural agents and emulsifying-dispersing agents. Emulsification tests were carried out and the stability of the emulsions evaluated. The evaluation of the effect of co-formulants on the growth of conidia of T. asperellum was done by reading the optical densities of the formulated samples on multi-plates using a plate reader. The test on detached cocoa pods was done by treating the cocoa pods with selected formulations at 1.10(7) conidia/ml and inoculation of the treated cocoa pods was done 24 hours later with zoospores of P. megakarya at 1.10(5) zoospores/ml. The growth of necrosis on the fruits was measured daily. The screening of co-formulants and emulsification tests ended up with the selection of two formulations. The first composed of conidia of T. asperellum, groundnut oil, Tensiofix NTM and Tensiofix 869. The second differed from the first by utilisation of palm oil as the solvent. These formulations proved stable when diluted in water with 1% and 0.5% of sedimentation respectively after 24 hours. The viability test of the conidia indicated that the different formulations selected did not have a fungitoxic effect. The test on detached cocoa pods showed an improved efficacy of T. asperellum to control the disease. The growth rates of necrosis were 6.29 mm/day, 7.25 mm/day and 31.6 mm/day for treatment with formulation 1, pure conidia and control treated with water respectively.

  16. Geomyces destructans sp. nov. associated with Bat white-nose syndrome

    USGS Publications Warehouse

    Gargas, A.; Trest, M.T.; Christensen, M.; Volk, T.J.; Blehert, D.S.

    2009-01-01

    We describe and illustrate the new species Geomyces destructans. Bats infected with this fungus present with powdery conidia and hyphae on their muzzles, wing membranes, and/or pinnae, leading to description of the accompanying disease as white-nose syndrome, a cause of widespread mortality among hibernating bats in the northeastern US. Based on rRNA gene sequence (ITS and SSU) characters the fungus is placed in the genus Geomyces, yet its distinctive asymmetrically curved conidia are unlike those of any described Geomyces species.

  17. A preliminary evaluation of the potential of Beauveria bassiana for bed bug control.

    PubMed

    Barbarin, Alexis M; Jenkins, Nina E; Rajotte, Edwin G; Thomas, Matthew B

    2012-09-15

    Residual biopesticide treatments of Beauveria bassiana were tested against the bed bug Cimex lectularius. An oil formulation of conidia was applied to different substrates. Bed bugs were exposed for 1 h, transferred to an unsprayed environment and monitored for mortality. Separate bioassays evaluated the effect of bed bug strain, sex, life stage, and exposure substrate on mortality. Rapid mortality was observed in all bioassays, with bed bugs exposed to treated jersey knit cotton dying most rapidly. A further assay demonstrated efficient autodissemination of conidia from exposed bed bugs to unexposed bed bugs within artificial harborages.

  18. Membrane permeability and the loss of germination factor from Neurospora crassa at low water activities

    NASA Technical Reports Server (NTRS)

    Charlang, G.; Horowitz, N. H.

    1974-01-01

    Neurospora crassa conidia incubating in buffer at low water activities release a germination-essential component as well as 260-nm absorbing and ninhydrin-positive materials, regardless of whether an electrolyte or nonelectrolyte is used to reduce water activity. Chloroform and antibiotics known to increase cell-membrane permeability have a similar effect. This suggests that membrane damage occurs in media of low water activity and that an increase in permeability is responsible for the release of cellular components. The damage caused in media of low water activity is nonlethal in most cases, and the conidia recover when transferred to nutrient medium.

  19. Isolation and identification of the conidial germination factor of Neurospora crassa

    NASA Technical Reports Server (NTRS)

    Horowitz, N. H.; Charlang, G.; Horn, G.; Williams, N. P.

    1976-01-01

    The germination-essential substance (germination factor /GF/) that is lost from conidia of Neurospora crassa on exposure to solutions of low water activity has been isolated and identified as a group of iron-transport compounds, or siderochromes. The principal siderochrome of conidia is ferricrocin, a cyclic hexapeptide. A closely related substance, ferrichrome C, is tentatively identified as a minor constituent. The same substances are also present in extracts of mycelium along with small amounts of a third siderochrome, which has not been identified. The GF activity of culture filtrates is due to coprogen, the only siderochrome previously identified with N. crassa.

  20. Phosphorus availability modulates the toxic effect of silver on aquatic fungi and leaf litter decomposition.

    PubMed

    Funck, J Arce; Clivot, H; Felten, V; Rousselle, P; Guérold, F; Danger, M

    2013-11-15

    The functioning of forested headwater streams is intimately linked to the decomposition of leaf litter by decomposers, mainly aquatic hyphomycetes, which enables the transfer of allochthonous carbon to higher trophic levels. Evaluation of this process is being increasingly used as an indicator of ecosystem health and ecological integrity. Yet, even though the individual impacts of contaminants and nutrient availability on decomposition have been well studied, the understanding of their combined effects remains limited. In the current study, we investigated whether the toxic effects of a reemerging contaminant, silver (Ag), on leaf litter decomposition could be partly overcome in situations where microorganisms were benefitting from high phosphorus (P) availability, the latter being a key chemical element that often limits detritus decomposition. We also investigated whether these interactive effects were mediated by changes in the structure of the aquatic hyphomycete community. To verify these hypotheses, leaf litter decomposition by a consortium of ten aquatic hyphomycete species was followed in a microcosm experiment combining five Ag contamination levels and three P concentrations. Indirect effects of Ag and P on the consumption of leaf litter by the detritivorous crustacean, Gammarus fossarum, were also evaluated. Ag significantly reduced decomposition but only at the highest concentration tested, independently of P level. By contrast, P and Ag interactively affected fungal biomass. Both P level and Ag concentrations shaped microbial communities without significantly affecting the overall species richness. Finally, the levels of P and Ag interacted significantly on G. fossarum feeding rates, high [Ag] reducing litter consumption and low P availability tending to intensify the feeding rate. Given the high level of contaminant needed to impair the decomposition process, it is unlikely that a direct effect of Ag on leaf litter decomposition could be observed in

  1. Agrobacterium tumefaciens-mediated transformation of Valsa mali: an efficient tool for random insertion mutagenesis.

    PubMed

    Wang, Caixia; Guan, Xiangnan; Wang, Hanyan; Li, Guifang; Dong, Xiangli; Wang, Guoping; Li, Baohua

    2013-01-01

    Valsa mali is a causal agent of apple and pear trees canker disease, which is a destructive disease that causes serious economic losses in eastern Asia, especially in China. The lack of an efficient transformation system for Valsa mali retards its investigation, which poses difficulties to control the disease. In this research, a transformation system for this pathogen was established for the first time using A. tumefaciens-mediated transformation (ATMT), with the optimal transformation conditions as follows: 10(6)/mL conidia suspension, cocultivation temperature 22°C, cocultivation time 72 hours, and 200  μ M acetosyringone (AS) in the inductive medium. The average transformation efficiency was 1015.00 ± 37.35 transformants per 10(6) recipient conidia. Thirty transformants were randomly selected for further confirmation and the results showed the presence of T-DNA in all hygromycin B resistant transformants and also revealed random and single gene integration with genetic stability. Compared with wild-type strain, those transformants exhibited various differences in morphology, conidia production, and conidia germination ability. In addition, pathogenicity assays revealed that 14 transformants had mitigated pathogenicity, while one had enhanced infection ability. The results suggest that ATMT of V. mali is a useful tool to gain novel insight into this economically important pathogen at molecular levels.

  2. Occurrence of toxicity among protease, amylase, and color mutants of a nontoxic soy sauce koji mold

    SciTech Connect

    Kalayanamitr, A.; Bhumiratana, A.; Flegel, T.W.; Glinsukon, T.; Shinmyo, A.

    1987-08-01

    A soy sauce koji mold, Aspergillus flavus var. columnaris Raper and Fennel (ATCC 44310), was treated with UV irradiation to obtain mutant strains possessing high protease activities, high amylase activities, and light-colored conidia. Selected mutant strains were tested for toxicity, and some were found acutely toxic to weanling rats, although all were negative for aflatoxin production.

  3. Population balance modeling of the conidial aggregation of Aspergillus niger.

    PubMed

    Lin, P-J; Grimm, L H; Wulkow, M; Hempel, D C; Krull, R

    2008-02-01

    Numerous biotechnological production processes are based on the submerse cultivation of filamentous fungi. Process design, however, is often hampered by the complex growth pattern of these organisms. In the morphologic development of coagulating filamentous fungi, like Aspergillus niger, conidial aggregation is the first step of filamentous morphogenesis. For a proper description of this phenomenon it is necessary to characterize conidial populations. Kinetic studies performed with an in-line particle size analyzer suggested that two distinct aggregation steps have to be considered. The first step of conidial aggregation starts immediately after inoculation. Both the rate constants of formation and disintegration of aggregates have been determined by measuring the concentration of conidia at the beginning of the cultivation and the concentration of particles at steady state during the first hours of cultivation. In contrast to the first aggregation step, where the collision of conidia is presumed to be responsible for the process, the second aggregation step is thought to be initiated by germination of conidia. Growing hyphae provide additional surface for the attachment of non- germinated conidia, which leads to a strong decrease in particle concentration. The specific hyphal length growth rate and the ratio of particle concentration to the growing adhesion hyphal surface are decisive matters of the second aggregation step. Both aggregation steps can be described by population dynamics and simulated using the program package PARSIVAL (PARticle SIze eVALution) for the treatment of general particle population balances.

  4. A monograph of the entomopathogenic genera Hypocrella, Moelleriella, and Samuelsia gen. nov. (Ascomycota, Hypocreales, Clavicipitaceae), and their aschersonia-like anamorphs in the Neotropics

    PubMed Central

    Chaverri, P.; Liu, M.; Hodge, K.T.

    2008-01-01

    The present taxonomic revision deals with Neotropical species of three entomopathogenic genera that were once included in Hypocrella s. l.: Hypocrella s. str. (anamorph Aschersonia), Moelleriella (anamorph aschersonia-like), and Samuelsia gen. nov (anamorph aschersonia-like). Species of Hypocrella, Moelleriella, and Samuelsia are pathogens of scale insects (Coccidae and Lecaniidae, Homoptera) and whiteflies (Aleyrodidae, Homoptera) and are common in tropical regions. Phylogenetic analyses of DNA sequences from nuclear ribosomal large subunit (28S), translation elongation factor 1-α (TEF 1-α), and RNA polymerase II subunit 1 (RPB1) and analyses of multiple morphological characters demonstrate that the three segregated genera can be distinguished by the disarticulation of the ascospores and shape and size of conidia. Moelleriella has filiform multi-septate ascospores that disarticulate at the septa within the ascus and aschersonia-like anamorphs with fusoid conidia. Hypocrella s. str. has filiform to long-fusiform ascospores that do not disarticulate and Aschersonia s. str. anamorphs with fusoid conidia. The new genus proposed here, Samuelsia, has filiform to long-fusiform ascospores that do not disarticulate and aschersonia-like anamorphs with small allantoid conidia. In addition, the present study presents and discusses the evolution of species, morphology, and ecology in Hypocrella, Moelleriella, and Samuelsia based on multigene phylogenetic analyses. PMID:18490956

  5. Physiological and antioxidant response by Beauveria bassiana Bals (Vuill.) to different oxygen concentrations.

    PubMed

    Garza-López, Paul Misael; Konigsberg, Mina; Gómez-Quiroz, Luis Enrique; Loera, Octavio

    2012-01-01

    The effect of three levels of oxygen (normal atmosphere (21% O(2)), low oxygen (16% O(2)) and enriched oxygen (26% O(2))) on the production and germination of conidia by Beauveria bassiana was evaluated using rice as a substrate. The maximum yield of conidia was achieved under hypoxia (16% O(2)) after 8 days of culture (1.51 × 10(9) conidia per gram of initial dry substrate), representing an increase of 32% compared to the normal atmosphere. However, germination was reduced by at least 27% due to atmospheric modifications. Comparison of antioxidant enzyme activity (superoxide dismutases and catalases) with the oxidation profiles of biomolecules (proteins and lipids) showed that a decrease in catalase activity in the final days of culture coincided with an increase in the amount of oxidized lipids, showing that oxidative stress was a consequence of pulses of different concentrations of O(2). This is the first study describing oxidative stress induction by atmospheric modification, with practical implications for conidia production.

  6. Effects of catalase on the accumulation of H(2)O(2) in rice cells inoculated with rice blast fungus, Magnaporthe oryzae.

    PubMed

    Tanabe, Shigeru; Nishizawa, Yoko; Minami, Eiichi

    2009-10-01

    Roles of H(2)O(2) in the infection process of Magnaporthe oryzae on rice were investigated. In a leaf sheath assay for up to 48 h post-inoculation, the absence or presence of catalase in the conidia suspension was correlated with the level of accumulated H(2)O(2) in infected leaf cells, as observed by staining with 3',3-diaminobenzidine tetrahydrochloride. In the incompatible interaction, the appearance of autofluorescence or frequency of cell death characterized by granulation (symptoms characteristic of hypersensitive responses) was not significantly affected by the presence of catalase in the conidia suspension. In the leaf blade assay, inoculation of compatible conidia in the presence of catalase produced more severe symptoms than that of conidia in the absence of catalase at 6 days post-inoculation. These results suggest that, in this host-parasite interaction, the primary role of host-produced H(2)O(2) is in limiting hyphal growth after penetration through toxic action. Furthermore, in incompatible interactions, H(2)O(2) is implied not to be a major mediator of hypersensitive cell death.

  7. Biotechnology of Aureobasidium pullulans: A phylogenetic perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aureobasidium pullulans is a fungus historically included among the "black yeasts." Although many strains are predominantly yeast-like, the species is actually polymorphic, exhibiting complex forms ranging from blastic conidia and swollen cells to pseudophyphae, hyphae, and chlamydospores. A. pull...

  8. WetA Is Required for Conidiogenesis and Conidium Maturation in the Ascomycete Fungus Fusarium graminearum

    PubMed Central

    Son, Hokyoung; Kim, Myung-Gu; Min, Kyunghun; Lim, Jae Yun; Choi, Gyung Ja; Kim, Jin-Cheol; Chae, Suhn-Kee

    2014-01-01

    Fusarium graminearum, a prominent fungal pathogen that infects major cereal crops, primarily utilizes asexual spores to spread disease. To understand the molecular mechanisms underlying conidiogenesis in F. graminearum, we functionally characterized the F. graminearum ortholog of Aspergillus nidulans wetA, which has been shown to be involved in conidiogenesis and conidium maturation. Deletion of F. graminearum wetA did not alter mycelial growth, sexual development, or virulence, but the wetA deletion mutants produced longer conidia with fewer septa, and the conidia were sensitive to acute stresses, such as oxidative stress and heat stress. Furthermore, the survival rate of aged conidia from the F. graminearum wetA deletion mutants was reduced. The wetA deletion resulted in vigorous generation of single-celled conidia through autophagy-dependent microcycle conidiation, indicating that WetA functions to maintain conidial dormancy by suppressing microcycle conidiation in F. graminearum. Transcriptome analyses demonstrated that most of the putative conidiation-related genes are expressed constitutively and that only a few genes are specifically involved in F. graminearum conidiogenesis. The conserved and distinct roles identified for WetA in F. graminearum provide new insights into the genetics of conidiation in filamentous fungi. PMID:24186953

  9. Phylogeny and ecology of the ubiquitous saprobe Cladosporium sphaerospermum, with descriptions of seven new species from hypersaline environments

    PubMed Central

    Zalar, P.; de Hoog, G.S.; Schroers, H.-J.; Crous, P.W.; Groenewald, J.Z.; Gunde-Cimerman, N.

    2007-01-01

    Saprobic Cladosporium isolates morphologically similar to C. sphaerospermum are phylogenetically analysed on the basis of DNA sequences of the ribosomal RNA gene cluster, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S rDNA (ITS) and the small subunit (SSU) rDNA as well as β-tubulin and actin gene introns and exons. Most of the C. sphaerospermum-like species show halotolerance as a recurrent feature. Cladosporium sphaerospermum, which is characterised by almost globose conidia, is redefined on the basis of its ex-neotype culture. Cladosporium dominicanum, C. psychrotolerans, C. velox, C. spinulosum and C. halotolerans, all with globoid conidia, are newly described on the basis of phylogenetic analyses and cryptic morphological and physiological characters. Cladosporium halotolerans was isolated from hypersaline water and bathrooms and detected once on dolphin skin. Cladosporium dominicanum and C. velox were isolated from plant material and hypersaline water. Cladosporium psychrotolerans, which grows well at 4 °C but not at 30 °C, and C. spinulosum, having conspicuously ornamented conidia with long digitate projections, are currently only known from hypersaline water. We also newly describe C. salinae from hypersaline water and C. fusiforme from hypersaline water and animal feed. Both species have ovoid to ellipsoid conidia and are therefore reminiscent of C. herbarum. Cladosporium langeronii (= Hormodendrum langeronii) previously described as a pathogen on human skin, is halotolerant but has not yet been recorded from hypersaline environments. PMID:18490999

  10. Photoprotective and Antimutagenic Activity of Agaricus subrufescens Basidiocarp Extracts.

    PubMed

    da Costa, M C D; Regina, M; Cilião Filho, M; Linde, G A; do Valle, J S; Paccola-Meirelles, L D; Colauto, N B

    2015-10-01

    The photoprotective and antimutagenic activity of opened and closed basidiocarps of Agaricus subrufescens (=A. blazei; =A. brasiliensis) obtained by different extraction methods were evaluated on Aspergillus nidulans conidia submitted to ultraviolet (UV) light. The aqueous extracts were obtained by three extraction methods: maceration, infusion, and decoction, at two different extraction times. The extracts of A. subrufescens did not present toxicity for A. nidulans conidia. A suspension of A. nidulans conidia was submitted to extracts before and after the exposure to UV light. All basidiocarp extracts, regardless of the extraction method or development stage, protected A. nidulans conidia against the damaging effects of the mutagenic agent. The antimutagenic and photoprotective activity was strengthened with extracts obtained by 168-h maceration, followed by 24-h maceration and 60-min infusion and, at last, by 30-min infusion. Although the extracts presented protector effect as well as recoverer effect to the action of UV light, the preventive effect was more evident. Differences in the biological activity in function of the different development stages were detected with greater antimutagenic and photoprotective activity for the opened basidiocarps. However, the extraction method is the most important factor to be considered when compared to the basidiocarp development stage to obtain better antimutagenic and photoprotective activity of A. subrufescens basidiocarps.

  11. Conidiogenic effects of mannose-binding lectins isolated from cotyledons of red kidney bean (Phaseolus vulgaris) on Alternaria alternata.

    PubMed

    Alizadeh, Hossein; Leung, David W M; Cole, Anthony L J

    2011-01-01

    Effect of proteinaceous extracts from red kidney bean cotyledons on mycelium of Alternaria alternata growing on potato dextrose agar (PDA) plates was investigated. Unexpectedly, conidia formation was induced in response to applied crude extracts. A PDA disc method was developed to quantify conidia formed. A purified fraction retaining conidiation inducing effect (CIE) was obtained following several protein purification procedures including the last step of eluting bound proteins from an Affi-gel blue gel column. Based on MALDI (matrix assisted laser desorption/ionization) mass spectrometric analysis, a previously identified mannose-binding lectin (MBL) called PvFRIL (Phaseolus vulgaris fetal liver tyrosine kinase 3-receptor interacting lectin) was present in this conidiation inducing fraction. The PvFRIL was subsequently purified using a single step mannose-agarose affinity column chromatography. When the lectin was applied exogenously to A. alternata, increased conidiation resulted. The conidia produced in response to the MBL were similar to those induced by other methods and their germ tubes were longer after 12 h growth than those induced under white light. To our knowledge this is the first report of exogenous application of a PvFRIL or another purified protein from a plant inducing conidia formation in a fungus.

  12. Pathogenicity of Metarhizium anisopliae for Ceratitis capitata (Wied.) (Diptera: Tephritidae) in soil with different pesticides.

    PubMed

    Mochi, Dinalva A; Monteiro, Antonio C; De Bortoli, Sergio A; Dória, Háyda O S; Barbosa, José C

    2006-01-01

    This research intended to investigate if the presence of pesticides in the soil could affect the pathogenicity of Metarhizium anisopliae Metsch. (Sorokin) for Ceratitis capitata (Wied.) and assess the effect of conidia application as suspension or dry conidia. The fungicides chlorothalonyl and tebuconazol, the acaricide abamectin, the insecticide trichlorfon, and the herbicide ametrin were applied at the manufacturer-recommended doses. Soil samples were placed in glass flasks and were given the fungus as conidial suspension or dry. After pesticide application, 20 3rd-instar larvae were placed in the soil. The flasks were sealed with voile fabric and incubated at 27 +/- 0.5 masculineC for nine days, until adult emergence; incubation continued for four more days at room temperature. The total insect survival was significantly affected and pathogenic activity was detected from the pupa stage on. Pupa survival was reduced (P<0.05); the same occurred during the adult phase. No effect was observed at the larval stage. The pesticides applied to the soil affected the activity of M. anisopliae slightly: only in the dry conidia assay the fungicides chlorothalonyl and tebuconazole reduced (86.2% and 82.5%, respectively) the survival period of C. capitata compared to the control (95.0%). The techniques used for conidia application did not influence the total insect survival rate, but conidial suspension applied on soil surface reduced survival during the pupae and adult phases.

  13. Use of phosphite salts in laboratory and semi-commercial tests to control citrus postharvest decay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    EC50 concentrations of potassium phosphite (KP) to inhibit germination of Penicillium digitatum conidia were 229, 334, 360, 469, 498, or 580 mg/liter at pH 3, 4, 5, 6, 7, or 8, respectively. Increasing phosphate content in media reduced phosphite toxicity. To control green or blue mold, fruit were i...

  14. Exposure of bed bugs to metarhizium anisopliae, and the effect of defensive secretions on fungal growth in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bed bugs Cimex lectularius were treated with conidia of the entomopathogenic fungus Metarhizium anisopliae by topical, spray, and contact exposure. One week post-exposure, inconsistent mortalities were observed, averaging 30% across all treatment groups and replicates. Microscopic examination of top...

  15. Occurrence of toxicity among protease, amylase, and color mutants of a nontoxic soy sauce koji mold.

    PubMed Central

    Kalayanamitr, A; Bhumiratana, A; Flegel, T W; Glinsukon, T; Shinmyo, A

    1987-01-01

    A soy sauce koji mold, Aspergillus flavus var. columnaris Raper and Fennel (ATCC 44310), was treated with UV irradiation to obtain mutant strains possessing high protease activities, high amylase activities, and light-colored conidia. Selected mutant strains were tested for toxicity, and some were found acutely toxic to weanling rats, although all were negative for aflatoxin production. PMID:2444160

  16. Chitin synthases with a myosin motor-like domain control the resistance of Aspergillus fumigatus to echinocandins.

    PubMed

    Jiménez-Ortigosa, Cristina; Aimanianda, Vishukumar; Muszkieta, Laetitia; Mouyna, Isabelle; Alsteens, David; Pire, Stéphane; Beau, Remi; Krappmann, Sven; Beauvais, Anne; Dufrêne, Yves F; Roncero, César; Latgé, Jean-Paul

    2012-12-01

    Aspergillus fumigatus has two chitin synthases (CSMA and CSMB) with a myosin motor-like domain (MMD) arranged in a head-to-head configuration. To understand the function of these chitin synthases, single and double csm mutant strains were constructed and analyzed. Although there was a slight reduction in mycelial growth of the mutants, the total chitin synthase activity and the cell wall chitin content were similar in the mycelium of all of the mutants and the parental strain. In the conidia, chitin content in the ΔcsmA strain cell wall was less than half the amount found in the parental strain. In contrast, the ΔcsmB mutant strain and, unexpectedly, the ΔcsmA/ΔcsmB mutant strain did not show any modification of chitin content in their conidial cell walls. In contrast to the hydrophobic conidia of the parental strain, conidia of all of the csm mutants were hydrophilic due to the presence of an amorphous material covering the hydrophobic surface-rodlet layer. The deletion of CSM genes also resulted in an increased susceptibility of resting and germinating conidia to echinocandins. These results show that the deletion of the CSMA and CSMB genes induced a significant disorganization of the cell wall structure, even though they contribute only weakly to the overall cell wall chitin synthesis.

  17. DOSE-DEPENDENT ALLERGIC ASTHMA RESPONSES TO PENICILLIUM CHRYSOGENUM

    EPA Science Inventory

    ABSTRACT
    Indoor mold has been associated with development of allergic asthma. Penicillium chrysogenum, a common indoor mold, is known to have several allergens and its viable conidia can induce allergic responses in a mouse model of allergic penicilliosis. The hypothesis o...

  18. Feasibility of detecting Aflatoxin B1 in single maize kernels using hyperspectral imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The feasibility of detecting Aflatoxin B1 (AFB1) in single maize kernel inoculated with Aspergillus flavus conidia in the field, as well as its spatial distribution in the kernels, was assessed using near-infrared hyperspectral imaging (HSI) technique. Firstly, an image mask was applied to a pixel-b...

  19. Near-infrared hyperspectral imaging for detecting Aflatoxin B1 of maize kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The feasibility of detecting the Aflatoxin B1 in maize kernels inoculated with Aspergillus flavus conidia in the field was assessed using near-infrared hyperspectral imaging technique. After pixel-level calibration, wavelength dependent offset, the masking method was adopted to reduce the noise and ...

  20. Metacridamide B methanol-d4 monosolvate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The title compound was extracted from conidia of the fungus Metarhizium acridum. Crystals were obtained as a methanol-d4 solvate. The tail part of the 4-methylhexan-2-yl group exhibits disorder over two positions, with an occupancy ratio of 0.682 (9):0.318 (9). The crystal structure confirms the abs...

  1. Three new hecogenin glycosides from fermented leaves of Agave americana.

    PubMed

    Jin, Jian-Ming; Liu, Xi-Kui; Yang, Chong-Ren

    2003-06-01

    Eight steroidal compounds, including three new hecogenin glycosides, agamenosides D-F, were isolated from the fermented leaves of Agave americana. The structures of the new steroidal saponins were elucidated by spectroscopic data and chemical methods. The activity of the isolated compounds on deformations of mycelia germinated from conidia of Pyricularia oaryzae P-2b was evaluated.

  2. Efficacy of spray applications of entomopathogenic fungi against western flower thrips infesting greenhouse impatiens under variable moisture conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficacy tests of three entomopathogenic fungi (Beauveria bassiana strain GHA, Metarhizium brunneum strain F52, and Metarhizium anisopliae s.l. strain ESC-1) were conducted against thrips infesting greenhouse crops of single impatiens under variable moisture conditions. Fungal conidia suspended in 0...

  3. Presence of Fusarium graminearum in air associated with sorghum fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum can be included in crop rotations with wheat. However, there are no known reports on the effects of sorghum grown in rotation with wheat on the epidemiology of head scab caused by Fusarium graminearum. Conidia in air samples within two sorghum fields were collected by passive spore trapping ...

  4. Direct Polymerase Chain Reaction-Based Detection of Cercospora Beticola in Field Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cercospora beticola, the causal agent of Cercospora leaf spot of sugar beet, survives as pseudostromata in infected beet leaf residues in the soil. Under optimal conditions, overwintering propagules germinate and produce conidia that are dispersed as primary inoculum to initiate infection in sugar b...

  5. Impact of metarhizium brunneum petch clavicipitaceae (Hypocreales) on pre-imaginal Rhagoletis indifferens (Diptera: Tephritidae) within and on the surface of orchard soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When last instar laboratory-reared Rhagoletis indifferens were allowed to pupate within non-sterile orchard soil containing Metarhizium brunneum isolate F52 conidia, a dose related proportion died from developmental abnormalities and mycosis. Similarly, when last instar larvae entered soil that was ...

  6. Impact of Metarhizium brunneum (Hypocreales: Clavicipitaceae) on pre-imaginal Rhagoletis indifferens (Diptera: Tephritidae) within and on the surface of orchard soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When last instar laboratory-reared Rhagoletis indifferens (Cherry Fruit Fly) were allowed to pupate within non-sterile orchard soil containing incorporated Metarhizium brunneum isolate F52 conidia, a dose-related proportion died from developmental abnormalities and mycosis. Similarly, when prepupal ...

  7. Effects of surfactants on conidial germination of Myrothecium verrucaria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Myrothecium verrucaria has been employed as a unique biological control agent because it is highly effective against several annual and perennial weeds, including red vine, trumpet creeper, redroot pigweed, kudzu, hempsesbania and sicklepod. Although aerial conidia of M. verrucaria are hydrophilic, ...

  8. Ranking cultivated blueberry for Mummy Berry Blight and Fruit Infection Incidence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mummy berry is an important disease of cultivated blueberry. The disease has two distinct phases; a blighting phase initiated by ascospores and a fruit infection stage initiated by conidia. In this study we investigated the resistance of more than 100 blueberry cultivar to both phases of the disease...

  9. Mummy Berry Fruit Rot and Shoot Blight Incidence in Blueberry: Prediction, Ranking, and Stability in a Long-term Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mummy berry is an important disease of cultivated blueberry. The disease has two distinct phases; a blighting phase initiated by ascospores and a fruit infection stage initiated by conidia. In this study we investigated blueberry cultivar resistance to both phases of the disease and, utilizing ‘stan...

  10. Effect of prior vegetative growth, inoculum density and light on conidiation in Erysiphe necator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A driving force in epidemics of grape powdery mildew is the abundant production of conidia. Our objective was to better define the three factors involved in the qualitative change that occurs when a mildew colony switches from vegetative growth to sporulation –inoculum density, light, and a sporulat...

  11. Differential gene expression during conidiation in the grape powdery mildew fungus, Erysiphe necator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asexual sporulation (conidiation) is coordinately regulated in the grape powdery mildew fungus Erysiphe necator, but nothing is known about its genetic regulation. We hypothesized that genes required for conidiation in other fungi would be up-regulated at conidiophore initiation and/or full conidia...

  12. A role for the asexual spores in infection of Fraxinus excelsior by the ash-dieback fungus Hymenoscyphus fraxineus

    PubMed Central

    Fones, Helen Nicola; Mardon, Charlotte; Gurr, Sarah Jane

    2016-01-01

    The invasive pathogen, ash dieback fungus Hymenoscyphus fraxineus, is spreading rapidly across Europe. It shows high levels of outcrossing and limited population structure, even at the epidemic front. The anamorphic (asexual) form produces prolific conidia, thought to function solely as spermatia (male gametes), facilitating gene flow between sympatric strains. Here, we show that conidia are capable of germination on ash leaves and in vitro, and can infect seedlings via leaves or soil. In leaves, germlings form structures resembling fruiting bodies. Additionally, H. fraxineus colonises ash debris and grows in soil in the absence of ash tissues. We propose an amended life-cycle in which wind-dispersed, insect-vectored or water-spread conidia infect ash and may sporulate in planta, as well as in forest debris. This amplifies inoculum levels of different strains in ash stands. In combination with their function as spermatia, conidia thus act to maximise gene flow between sympatric strains, including those originally present at low inoculum. Such mixing increases evolutionary potential, as well as enhancing the likelihood of gene introgression from closely-related strains or assimilation of further genetic diversity from parental Asian populations. This scenario increases the adaptability of H. fraxineus to new climates and, indeed, onto new host species. PMID:27694963

  13. Host, Pathogen, and Environmental Characteristics Predict White-Nose Syndrome Mortality in Captive Little Brown Myotis (Myotis lucifugus)

    PubMed Central

    Johnson, Joseph S.; Reeder, DeeAnn M.; McMichael, James W.; Meierhofer, Melissa B.; Stern, Daniel W. F.; Lumadue, Shayne S.; Sigler, Lauren E.; Winters, Harrison D.; Vodzak, Megan E.; Kurta, Allen; Kath, Joseph A.; Field, Kenneth A.

    2014-01-01

    An estimated 5.7 million or more bats died in North America between 2006 and 2012 due to infection with the fungus Pseudogymnoascus destructans (Pd) that causes white-nose syndrome (WNS) during hibernation. The behavioral and physiological changes associated with hibernation leave bats vulnerable to WNS, but the persistence of bats within the contaminated regions of North America suggests that survival might vary predictably among individuals or in relation to environmental conditions. To investigate variables influencing WNS mortality, we conducted a captive study of 147 little brown myotis (Myotis lucifugus) inoculated with 0, 500, 5 000, 50 000, or 500 000 Pd conidia and hibernated for five months at either 4 or 10°C. We found that female bats were significantly more likely to survive hibernation, as were bats hibernated at 4°C, and bats with greater body condition at the start of hibernation. Although all bats inoculated with Pd exhibited shorter torpor bouts compared to controls, a characteristic of WNS, only bats inoculated with 500 conidia had significantly lower survival odds compared to controls. These data show that host and environmental characteristics are significant predictors of WNS mortality, and that exposure to up to 500 conidia is sufficient to cause a fatal infection. These results also illustrate a need to quantify dynamics of Pd exposure in free-ranging bats, as dynamics of WNS produced in captive studies inoculating bats with several hundred thousand conidia may differ from those in the wild. PMID:25409028

  14. Aspergillus fumigatus evades immune recognition during germination through loss of toll-like receptor-4-mediated signal transduction.

    PubMed

    Netea, Mihai G; Warris, Adilia; Van der Meer, Jos W M; Fenton, Matthew J; Verver-Janssen, Trees J G; Jacobs, Liesbeth E H; Andresen, Tonje; Verweij, Paul E; Kullberg, Bart Jan

    2003-07-15

    Peritoneal macrophages from Toll-like receptor (TLR) 4-deficient ScCr mice produced less tumor necrosis factor, interleukin (IL)-1alpha, and IL-1beta than did macrophages of control mice, when stimulated with conidia, but not with hyphae, of Aspergillus fumigatus, a finding suggesting that TLR4-mediated signals are lost during germination. This hypothesis was confirmed by use of a TLR4-specific fibroblast reporter cell line (3E10) that responded to the conidia, but not to the hyphae, of A. fumigatus. In contrast, macrophages from TLR2-knockout mice had a decreased production of proinflammatory cytokines in response to both Aspergillus conidia and Aspergillus hyphae, and these results were confirmed in 3E10 cells transfected with human TLR2. In addition, Aspergillus hyphae, but not Aspergillus conidia, stimulated production of IL-10 through TLR2-dependent mechanisms. In conclusion, TLR4-mediated proinflammatory signals, but not TLR2-induced anti-inflammatory signals, are lost on Aspergillus germination to hyphae. Therefore, phenotypic switching during germination may be an important escape mechanism of A. fumigatus that results in counteracting the host defense.

  15. Biochemical analysis of plant protection afforded by a nonpathogenic endophytic mutant of Colletotrichum magna

    SciTech Connect

    Redman, R.S.; Rodriguez, R.J. Univ. of Washington, Seattle, WA . Dept. of Botany); Clifton, D.R.; Morrel, J.; Brown, G. ); Freeman, S. . Dept. of Plant Pathology)

    1999-02-01

    A nonpathogenic mutant of Colletotrichum magna (path-1) was previously shown to protect watermelon (Citrullus lanatus) and cucumber (Cucumis sativus) seedlings from anthracnose disease elicited by wild-type C. magna. Disease protection was observed in stems of path-1-colonized cucurbits but not in cotyledons, indicating that path-1 conferred tissue-specific and/or localized protection. Plant biochemical indicators of a localized and systemic (peroxidase, phenylalanine ammonia-lyase, lignin, and salicylic acid) plant-defense response were investigated in anthracnose-resistant and-susceptible cultivars of cucurbit seedlings exposed to four treatments: (1) water (control), (2) path-1 conidia, (3) wild-type conidia, and (4) challenge conditions (inoculation into path-1 conidia for 48 h and then exposure to wild-type conidia). Collectively, these analyses indicated that disease protection in path-1-colonized plants was correlated with the ability of these plants to mount a defense response more rapidly and to equal or greater levels than plants exposed to wild-type C. magna alone. Watermelon plants colonized with path-1 were also protected against disease caused by Colletotrichum orbiculare and Fusarium oxysporum. A model based on the kinetics of plant-defense activation is presented to explain the mechanism of path-1-conferred disease protection.

  16. Performance of fogged disinfectants to inactivate conida of Penicillium digitatum within citrus degreening rooms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fogging with formaldehyde of citrus packinghouses when the fruit are absent is a practice to control conidia of Penicillium digitatum (Pers.) Sacc., cause of citrus green mold. Replacements for formaldehyde in these facilities are needed because of worker and environmental health issues. To evaluate...

  17. Genetic diversity and population structure of Fusicladium effusum on pecan in the U.S.A.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusicladium effusum causes pecan scab, which is the most destructive disease of pecan in the U.S.A. The disease is known to be spread through asexually produced conidia in rain splash and wind. The fungus has demonstrated pathogenic diversity, yet there is no information on its genetic diversity or ...

  18. Laboratory and field evaluation of an entomopathogenic fungus, Isaria cateniannulata strain 08XS‐1, against Tetranychus urticae (Koch)

    PubMed Central

    Zhang, Xiaona; Zou, Xiao; Guo, Jianjun

    2016-01-01

    Abstract BACKGROUND The two‐spotted mite, Tetranychus urticae Koch, is one of the most serious mite pests of crops throughout the world. Biocontrol of the mite with fungal agents has long been paid much attention because of the development of insecticide resistance and the severe restriction of chemical pesticides. In this study, the efficacy of submerged conidia of the entomopathogenic fungus Isaria cateniannulata strain 08XS‐1 against T. urticae eggs, larvae and female adults was evaluated at different temperatures and humidity in the laboratory and under field conditions. RESULTS The results showed that a suspension of 2 × 107 submerged conidia mL −1 caused the highest mortalities of mite eggs, larvae and females (100, 100 and 70% respectively) at 100% relative humidity and 25 °C in the laboratory. In the field experiments against the mites, a suspension of 2 × 108 submerged conidia mL −1 achieved significant efficiency – the relative control effects were 88.6, 83.8 and 83%, respectively, in cucumber, eggplant and bean fields after 10 days of treatment. CONCLUSION The results suggest that the I. cateniannulata strain 08XS‐1 is a potential fungal agent, with acceptable production cost of conidia, against T. urticae in the field in an area such as southwestern China with higher air humidity. © 2016 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:26775712

  19. Silver enhances the in vitro antifungal activity of the saponin, CAY-1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The separate fungicidal properties of purified CAY-1, dissolved silver, and EDTA were studied, as were the abilities of silver or EDTA to enhance CAY-1 fungicidal properties. Nongerminated and germinating conidia of A. flavus, A. fumigatus, A. niger, F. moniliforme, F. oxysporum and F. solani were ...

  20. Successful treatment of osseous blastomycosis without pulmonary or disseminated disease and review of the literature.

    PubMed

    Day, Shandra R; Weiss, David B; Hazen, Kevin C; Moore, Christopher C

    2014-06-01

    Blastomycosis commonly occurs following inhalation of Blastomyces dermatitidis conidia causing a pulmonary infection and can disseminate to extrapulmonary sites. Osseous involvement primarily results from hematogenous spread, but in rare cases, direct inoculation can occur. We describe a case of osseous blastomycosis without pulmonary or disseminated disease successfully treated with posaconazole.

  1. Successful Treatment of Osseous Blastomycosis without Pulmonary or Disseminated Disease and Review of the Literature

    PubMed Central

    Day, Shandra R.; Weiss, David B.; Hazen, Kevin C.; Moore, Christopher C.

    2014-01-01

    Blastomycosis commonly occurs following inhalation of Blastomyces dermatitidis conidia causing a pulmonary infection and can disseminate to extrapulmonary sites. Osseous involvement primarily results from hematogenous spread but in rare cases direct inoculation can occur. We describe a case of osseous blastomycosis without pulmonary or disseminated disease successfully treated with posaconazole. PMID:24703876

  2. Transcriptome analysis of the blueberry-mummy berry pathosystem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mummy berry disease of blueberry, casual agent Monilinia vaccinii-corymbosi, has two distinct phases- a blight stage of young foliage and flowers and a flower infection stage that leads to mummified fruit (pseudoscelrotia). The flower infections stage requires conidia to germinate on the style and g...

  3. Metacridamides A and B from the biocontrol fungus metarhizium acridum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metarhizium acridum, an entomopathogenic fungus, has been commercialized and used successfully for biocontrol of grasshopper pests in Africa and Australia. As part of an effort to catalog the secondary metabolites of this fungus we discovered that its conidia produce two novel 17-membered macrocycl...

  4. Serinocyclins A and B, Cyclic Heptapeptides from Metarhizium anisopliae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two new cyclic heptapeptides, serinocyclins A (1) and B (2), were isolated from conidia of the entomopathogenic fungus Metarhizium anisopliae. Structures were elucidated by a combination of mass spectrometric, NMR, and X-ray diffraction techniques. Serinocyclin A (1) contains three serine units, a...

  5. Horizontal transmission of Beauveria bassiana in Anastrepha ludens (Diptera: Tephritidae) under laboratory and field cage conditions.

    PubMed

    Toledo, Jorge; Campos, Sergio E; Flores, Salvador; Liedo, Pablo; Barrera, Juan F; Villaseñior, Antonio; Montoya, Pablo

    2007-04-01

    The virulence of two products of the fungus Beauveria bassiana (LCPP and Bassianil) on adult Anastrepha ludens (Loew) (Diptera: Tephritidae) and their effect on the mating performance of infected males was evaluated in laboratory and field cage tests. The horizontal transmission capacity of the fungus during copulation or attempted copulation also was quantified using inoculated males as well as the impact of infection on female fecundity and longevity. Both fungal products were found to be highly virulent (LCPP, mortality = 98.7% at 1 x 10(8) conidia per ml, LT50 = 4.20 d, LC50 = 9.35 x 10(5) conidia per ml; Bassianil, mortality = 99.3% at 1 X 10(8) conidia per ml, LT50 = 4.04 d, LC50 = 2.69 x 10(7) conidia per ml). Mating success of inoculated males was not affected compared with the control group during the 3 d postinoculation. Horizontal transmission to females during the first day was 80.6 and 84.3% through mating and 15.4 and 21.6% through attempts to mate and contact during courtship for the LCPP and Bassianil products, respectively. The fertility of infected females was notably reduced, and longevity did not extend beyond 15 d. Our results suggest the possibility of using sterile flies as fungus vectors in sterile insect technique programs, but the potential benefits and shortcomings of this approach require further investigation.

  6. Heat-stressed Metarhizium anisopliae: Viability (in vitro) and virulence (in vivo) assessments against the tick Rhipicephalus sanguineus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current study investigated the thermotolerance of Metarhizium anisopliae s.l. conidia from the commercial products Metarril® SP Organic and Metarril® WP. The efficacy of these M. anisopliae formulations against the tick Rhipicephalus sanguineus s.l. was studied in laboratory under optimum or hea...

  7. Entomopathogenic Fungi (Hypocreales) for Control of Potato Psyllid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory and field trials of the four isolates of entomopathogenic fungi, Isaria fumosorosea and Metarhizium anisopliae were conducted to evaluate their potential for control of the potato psyllid. In the laboratory, 2 ml aqueous suspension of 107conidia/ml in a of each isolate applied in a Potte...

  8. CCR4-Not Complex Subunit Not2 Plays Critical Roles in Vegetative Growth, Conidiation and Virulence in Watermelon Fusarium Wilt Pathogen Fusarium oxysporum f. sp. niveum

    PubMed Central

    Dai, Yi; Cao, Zhongye; Huang, Lihong; Liu, Shixia; Shen, Zhihui; Wang, Yuyan; Wang, Hui; Zhang, Huijuan; Li, Dayong; Song, Fengming

    2016-01-01

    CCR4-Not complex is a multifunctional regulator that plays important roles in multiple cellular processes in eukaryotes. In the present study, the biological function of FonNot2, a core subunit of the CCR4-Not complex, was explored in Fusarium oxysporum f. sp. niveum (Fon), the causal agent of watermelon wilt disease. FonNot2 was expressed at higher levels in conidia and germinating conidia and during infection in Fon-inoculated watermelon roots than in mycelia. Targeted disruption of FonNot2 resulted in retarded vegetative growth, reduced conidia production, abnormal conidial morphology, and reduced virulence on watermelon. Scanning electron microscopy observation of infection behaviors and qRT-PCR analysis of in planta fungal growth revealed that the ΔFonNot2 mutant was defective in the ability to penetrate watermelon roots and showed reduced fungal biomass in root and stem of the inoculated plants. Phenotypic and biochemical analyses indicated that the ΔFonNot2 mutant displayed hypersensitivity to cell wall perturbing agents (e.g., Congo Red and Calcofluor White) and oxidative stress (e.g., H2O2 and paraquat), decreased fusaric acid content, and reduced reactive oxygen species (ROS) production during spore germination. Our data demonstrate that FonNot2 plays critical roles in regulating vegetable growth, conidiogenesis and conidia morphology, and virulence on watermelon via modulating cell wall integrity, oxidative stress response, ROS production and FA biosynthesis through the regulation of transcription of genes involved in multiple pathways. PMID:27695445

  9. Proteome profiling of the dimorphic fungus Penicillium marneffei extracellular proteins and identification of glyceraldehyde-3-phosphate dehydrogenase as an important adhesion factor for conidial attachment.

    PubMed

    Lau, Susanna K P; Tse, Herman; Chan, Joanna S Y; Zhou, Anna C; Curreem, Shirly O T; Lau, Candy C Y; Yuen, Kwok-Yung; Woo, Patrick C Y

    2013-12-01

    Despite being the most important thermal dimorphic fungus causing systemic mycosis in Southeast Asia, the pathogenic mechanisms of Penicillium marneffei remain largely unknown. By comparing the extracellular proteomes of P. marneffei in mycelial and yeast phases, we identified 12 differentially expressed proteins among which glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and heat shock protein 60 (HSP60) were found to be upregulated in mycelial and yeast phases respectively. Based on previous findings in other pathogens, we hypothesized that these two extracellular proteins may be involved in adherence during P. marneffei-host interaction. Using inhibition assays with recombinant GAPDH (rGAPDH) proteins and anti-rGAPDH sera, we demonstrated that adhesion of P. marneffei conidia to fibronectin and laminin was inhibited by rGAPDH or rabbit anti-rGAPDH serum in a dose-dependent manner. Similarly, a dose-dependent inhibition of conidial adherence to A549 pneumocytes by rGAPDH or rabbit anti-rGAPDH serum was observed, suggesting that P. marneffei GAPDH can mediate binding of conidia to human extracellular matrix proteins and pneumocytes. However, HSP60 did not exhibit similar inhibition on conidia adherence, and neither GAPDH norHSP60 exhibited inhibition on adherence to J774 or THP-1 macrophage cell lines. This report demonstrates GAPDH as an adherence factor in P. marneffei by mediating conidia adherence to host bronchoalveolar epithelium during the early establishment phase of infection.

  10. Population structure and genetic diversity of Fusicladium effusum in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scab (Fusicladium effusum) is the most destructive disease of pecan in the Southeast US. Infection is thought to occur solely through asexually produced conidia. To explore the population structure and genetic diversity of F. effusum, populations were hierarchically sampled from 11 orchards in Alaba...

  11. Potential of a strain of the entomopathogenic fungus Beauveria bassiana (Hypocreales: Cordycipitaceae) as a biological control agent against western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Five Beauveria bassiana strains were evaluated for control of western flower thrips. Strain RSB was the most virulent, causing 69-96% mortality at concentrations of 1×104 – 1×107 conidia mL-1, 10 days after inoculation of first instars. In greenhouse trials, RSB applied to broccoli foliage signifi...

  12. O-Glycosylation in Cell Wall Proteins in Scedosporium prolificans Is Critical for Phagocytosis and Inflammatory Cytokines Production by Macrophages

    PubMed Central

    Xisto, Mariana I. D. S.; Bittencourt, Vera C. B.; Liporagi-Lopes, Livia Cristina; Haido, Rosa M. T.; Mendonça, Morena S. A.; Sassaki, Guilherme; Figueiredo, Rodrigo T.; Romanos, Maria Teresa V.; Barreto-Bergter, Eliana

    2015-01-01

    In this study, we analyze the importance of O-linked oligosaccharides present in peptidorhamnomannan (PRM) from the cell wall of the fungus Scedosporium prolificans for recognition and phagocytosis of conidia by macrophages. Adding PRM led to a dose-dependent inhibition of conidia phagocytosis, whereas de-O-glycosylated PRM did not show any effect. PRM induced the release of macrophage-derived antimicrobial compounds. However, O-linked oligosaccharides do not appear to be required for such induction. The effect of PRM on conidia-induced macrophage killing was examined using latex beads coated with PRM or de-O-glycosylated PRM. A decrease in macrophage viability similar to that caused by conidia was detected. However, macrophage killing was unaffected when beads coated with de-O-glycosylated PRM were used, indicating the toxic effect of O-linked oligosaccharides on macrophages. In addition, PRM triggered TNF-α release by macrophages. Chemical removal of O-linked oligosaccharides from PRM abolished cytokine induction, suggesting that the O-linked oligosaccharidic chains are important moieties involved in inflammatory responses through the induction of TNF-α secretion. In summary, we show that O-glycosylation plays a role in the recognition and uptake of S. prolificans by macrophages, killing of macrophages and production of pro- inflammatory cytokines. PMID:25875427

  13. Sporulation in Erysiphe necator: signals, differential gene expression and possible implications for disease management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abundant production of conidia is a driving factor for epidemics of grape powdery mildew (Erysiphe necator (syn. Uncinula necator). Previous investigations revealed evidence for a signal that coordinates the onset of asexual reproduction. The genetic basis for this signal in powdery mildews had not ...

  14. Biochemical analysis of plant protection afforded by a nonpathogenic endophytic mutant of Colletotrichum magna

    USGS Publications Warehouse

    Redman, R.S.; Freeman, S.; Clifton, D.R.; Morrel, J.; Brown, G.; Rodriguez, R.J.

    1999-01-01

    A nonpathogenic mutant of Colletotrichum magna (path-1) was previously shown to protect watermelon (Citrullus lanatus) and cucumber (Cucumis sativus) seedlings from anthracnose disease elicited by wild-type C. magna. Disease protection was observed in stems of path-1-colonized cucurbits but not in cotyledons, indicating that path-1 conferred tissue-specific and/or localized protection. Plant biochemical indicators of a localized and systemic (peroxidase, phenylalanine ammonia-lyase, lignin, and salicylic acid) 'plant-defense' response were investigated in anthracnose-resistant and -susceptible cultivars of cucurbit seedlings exposed to four treatments: (1) water (control), (2) path-1 conidia, (3) wild-type conidia, and (4) challenge conditions (inoculation into path-1 conidia for 48 h and then exposure to wild-type conidia). Collectively, these analyses indicated that disease protection in path-1 colonized plants was correlated with the ability of these plants to mount a defense response more rapidly and to equal or greater levels than plants exposed to wild-type C. magna alone. Watermelon plants colonized with path-1 were also protected against disease caused by Colletotrichum orbiculare and Fusarium oxysporum. A model based on the kinetics of plant-defense activation is presented to explain the mechanism of path-1-conferred disease protection.

  15. Evidence for sexual reproduction in Fusicladium effusum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusicladium effusum is the causal agent of pecan scab, the most prevalent and often catastrophic disease of pecan in the southeastern USA. Despite earlier efforts to determine a sexual stage, reproduction in F. effusum has been observed only by asexually produced conidia. However, the degree and dis...

  16. Host deception: Predaceous fungus, esteya vermicola, entices pine wood nematode by mimicking the scent of its host pine for nutrient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A nematophagous fungus, Esteya vermicola, is recorded as the first endoparasitic fungus of pine wood nematode (PWN), Burasphelenchus xylophilus, in the last century. E. vermicola exhibited high infectivity toward PWN in the laboratory conditions and conidia spraying of this fungus on Japanese red pi...

  17. Use of acoustic technology to monitor the time course of Rhynchophorus ferrugineus larval mortality in date palms after treatments with Beauveria bassiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spectral and temporal patterns of insect sound impulses were monitored daily for 23-d periods in 8, 10, or 5 small date palm trees containing larvae dipped in 0 (control), 104 (low), or 108 (high) conidia/ml doses of entomopathogenic fungus, Beauveria bassiana (Bb 203), respectively. Each tree conta...

  18. GERMINATION, VIABILITY AND CLEARANCE OF STACHYBOTRYS CHARTARUM IN THE LUNGS OF INFANT RATS

    EPA Science Inventory

    The fungus Stachybotrys chartarum has been associated with many adverse health effects including the condition known as idiopathic pulmonary hemorrhage in infants. In order to gain some insight into possible mechanisms, viable conidia of S. chartarum were instilled into the lung...

  19. Fungicidal and bactericidal properties of bisabolol and dragosantol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    a-bisabolol, a natural plant sesquiterpene alcohol, and dragosantol, a racemic mixture of synthetic bisabolol, were studied for their fungicidal properties separately against the nongerminated and germinating conidia of several species of Aspergillus and Fusarium which are problems in agriculture an...

  20. Multigene analysis suggests ecological speciation in the fungal pathogen Claviceps purpurea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Claviceps purpurea is an important pathogen of grasses and source of novel chemical compounds. Three groups within this species (G1, G2, and G3) have been recognized based on habitat association, sclerotia and conidia morphology, and alkaloid production. These groups have further been supported by g...

  1. Predatory activity of Butlerius nematodes and nematophagous fungi against Haemonchus contortus infective larvae.

    PubMed

    Silva, Manoel Eduardo da; Uriostegui, Miguel Angel Mercado; Millán-Orozco, Jair; Gives, Pedro Mendoza de; Hernández, Enrique Liébano; Braga, Fabio Ribeiro; Araújo, Jackson Victor de

    2017-01-26

    The purpose of this study was to evaluate the predatory activity of the nematode Butlerius spp. and fungal isolates of Duddingtonia flagrans, Clonostachys rosea, Arthrobotrys musiformis and Trichoderma esau against H. contortus infective larvae (L3) in grass pots. Forty-eight plastic gardening pots containing 140 g of sterile soil were used. Panicum spp. grass seeds (200 mg) were sown into each pot and individually watered with 10 mL of tap water. Twelve days after seeding, the pots were randomly divided into 6 groups (n=8). Two thousand H. contortus infective larvae (L3) were added to each group. Additionally, the following treatments were established: Group 1 - 2000 Butlerius spp. larvae; group 2 - A. musiformis (1x107 conidia); group 3 - T. esau (1x107 conidia); group 4 - C. rosea (1x107 conidia), group 5 - D. flagrans (1x107conidia) and Group 6 - no biological controller (control group). The larval population of H. contortus exposed to Butlerius spp. was reduced by 61.9%. Population reductions of 90.4, 66.7, 61.9 and 85.7% were recorded in the pots containing A. musiformis, T. esau, C. rosea and D. flagrans, respectively. The results of this study indicate that the predatory nematode Butlerius spp. and the assessed fungi display an important predatory activity can be considered suitable potential biological control agents.

  2. Morphological and molecular variation among species of the Fusarium dimerum species group

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The name Fusarium dimerum has been used in the past for saprotrophic fungi and opportunistic human pathogens with up to 3-septate but mostly 0- or 1-septate Fusarium-like conidia. On the basis of narrowly defined morphological characters, the varieties Pusillum, Nectrioides and Violaceum were disti...

  3. First report of the infection of insecticide-resistant malaria vector mosquitoes with an entomopathogenic fungus under field conditions

    PubMed Central

    2011-01-01

    Background Insecticide-resistant mosquitoes are compromising the ability of current mosquito control tools to control malaria vectors. A proposed new approach for mosquito control is to use entomopathogenic fungi. These fungi have been shown to be lethal to both insecticide-susceptible and insecticide-resistant mosquitoes under laboratory conditions. The goal of this study was to see whether entomopathogenic fungi could be used to infect insecticide-resistant malaria vectors under field conditions, and to see whether the virulence and viability of the fungal conidia decreased after exposure to ambient African field conditions. Methods This study used the fungus Beauveria bassiana to infect the insecticide-resistant malaria vector Anopheles gambiae s.s (Diptera: Culicidae) VKPER laboratory colony strain. Fungal conidia were applied to polyester netting and kept under West African field conditions for varying periods of time. The virulence of the fungal-treated netting was tested 1, 3 and 5 days after net application by exposing An. gambiae s.s. VKPER mosquitoes in WHO cone bioassays carried out under field conditions. In addition, the viability of B. bassiana conidia was measured after up to 20 days exposure to field conditions. Results The results show that B. bassiana infection caused significantly increased mortality with the daily risk of dying being increased by 2.5× for the fungus-exposed mosquitoes compared to the control mosquitoes. However, the virulence of the B. bassiana conidia decreased with increasing time spent exposed to the field conditions, the older the treatment on the net, the lower the fungus-induced mortality rate. This is likely to be due to the climate because laboratory trials found no such decline within the same trial time period. Conidial viability also decreased with increasing exposure to the net and natural abiotic environmental conditions. After 20 days field exposure the conidial viability was 30%, but the viability of control

  4. The Neurospora crassa mutant NcΔEgt-1 identifies an ergothioneine biosynthetic gene and demonstrates that ergothioneine enhances conidial survival and protects against peroxide toxicity during conidial germination.

    PubMed

    Bello, Marco H; Barrera-Perez, Viviana; Morin, Dexter; Epstein, Lynn

    2012-02-01

    Ergothioneine (EGT) is a histidine derivative with sulfur on the imidazole ring and a trimethylated amine; it is postulated to have an antioxidant function. Although EGT apparently is only produced by fungi and some prokaryotes, it is acquired by animals and plants from the environment, and is concentrated in animal tissues in cells with an EGT transporter. Monobromobimane derivatives of EGT allowed conclusive identification of EGT by LC/MS and the quantification of EGT in Colletotrichum graminicola and Neurospora crassa conidia and mycelia. EGT concentrations were significantly (α=0.05) higher in conidia than in mycelia, with approximately 17X and 5X more in C. graminicola and N. crassa, respectively. The first EGT biosynthetic gene in a fungus was identified by quantifying EGT in N. crassa wild type and knockouts in putative homologs of actinomycete EGT biosynthetic genes. NcΔEgt-1, a strain with a knockout in gene NCU04343, does not produce EGT, in contrast to the wild type. To determine the effects of EGT in vivo, we compared NcΔEgt-1 to the wild type. NcΔEgt-1 is not pleiotropically affected in rate of hyphal elongation in Vogel's medium either with or without ammonium nitrate and in the rate of germination of macroconidia on Vogel's medium. The superoxide-producer menadione had indistinguishable effects on conidial germination between the two strains. Cupric sulfate also had indistinguishable effects on conidial germination and on hyphal growth between the two strains. In contrast, germination of NcΔEgt-1 conidia was significantly more sensitive to tert-butyl hydroperoxide than the wild type; germination of 50% (GI(50)) of the NcΔEgt-1 conidia was prevented at 2.7 mM tert-butyl hydroperoxide whereas the GI(50) for the wild type was 4.7 mM tert-butyl hydroperoxide, or at a 1.7X greater concentration. In the presence of tert-butyl hydroperoxide and the fluorescent reactive oxygen species indicator 5-(and-6)-carboxy-2',7'-dichlorodihydrofluorescein

  5. Nothing special in the specialist? Draft genome sequence of Cryomyces antarcticus, the most extremophilic fungus from Antarctica.

    PubMed

    Sterflinger, Katja; Lopandic, Ksenija; Pandey, Ram Vinay; Blasi, Barbara; Kriegner, Albert

    2014-01-01

    The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes.

  6. The revenge of time: fungal deterioration of cultural heritage with particular reference to books, paper and parchment.

    PubMed

    Sterflinger, Katja; Pinzari, Flavia

    2012-03-01

    Hyphomycetous fungi - so called 'mould'- are the most important agents of biodeterioration in museums, museums' storage rooms, in libraries, collections and restoration studios. Fungi are able to live at low water activities, they are perfectly adapted to indoor environments and thrive in microclimatic niches caused by condensation, lack of ventilation or water retention by hygroscopic materials. Fungi spoil valuable pieces of art aesthetically, mechanically, chemically and by degradation of organic components. Historical material made of paper and oil paintings with high amounts of organic binders are especially susceptible to fungal deterioration. In order to prevent fungal contamination or to treat already contaminated objects an integrated approach including climate control, material-specific cleaning and application of carefully selected biocides is necessary.

  7. Nothing Special in the Specialist? Draft Genome Sequence of Cryomyces antarcticus, the Most Extremophilic Fungus from Antarctica

    PubMed Central

    Sterflinger, Katja; Lopandic, Ksenija; Pandey, Ram Vinay; Blasi, Barbara; Kriegner, Albert

    2014-01-01

    The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes. PMID:25296285

  8. Evaluation of the fungus Beauveria bassiana as a potential biological control agent against phlebotomine sand flies in Colombian coffee plantations.

    PubMed

    Reithinger, R; Davies, C R; Cadena, H; Alexander, B

    1997-09-01

    In Colombia, the entomopathogenic fungus Beauveria bassiana (Deuteromycotina: Hyphomycetes) is widely used to control the coffee berry borer Hypothenemus hampei (Coleoptera: Scolytidae) in coffee plantations. Recent studies suggested that this fungus is also pathogenic to several important vectors of disease, including Phlebotomus papatasi and Lutzomyia longipalpis (Diptera: Psychodidae). The present study evaluated the use of B. bassiana as a potential biological control agent against phlebotomine sand flies in Colombian coffee plantations. Histopathologic examination indicates that B. bassiana is unable to infect sand flies under natural conditions, although dead sand flies were shown to be readily infected. In addition, laboratory bioassays where flies were exposed to the fungus applied onto coffee plants (though not filter paper) showed lower mean survival times than the control.

  9. Microbial specialists in below-grade foundation walls in Scandinavia.

    PubMed

    Nunez, M; Hammer, H

    2014-10-01

    Below-grade foundation walls are often exposed to excessive moisture by water infiltration, condensation, leakage, or lack of ventilation. Microbial growth in these structures depends largely on environmental factors, elapsed time, and the type of building materials and construction setup. The ecological preferences of Actinomycetes (Actinobacteria) and the molds Ascotricha chartarum, Myxotrichum chartarum (Ascomycota), Geomyces pannorum, and Monocillium sp. (Hyphomycetes) have been addressed based on analyses of 1764 samples collected in below-grade spaces during the period of 2001-2012. Our results show a significant correlation between these taxa and moist foundation walls as ecological niches. Substrate preference was the strongest predictor of taxa distribution within the wall, but the taxa's physiological needs, together with gradients of abiotic factors within the wall structure, also played a role. Our study describes for the first time how the wall environment affects microbial growth.

  10. Heterotrimeric Gα protein Pga1 from Penicillium chrysogenum triggers germination in response to carbon sources and affects negatively resistance to different stress conditions.

    PubMed

    García-Rico, Ramón Ovidio; Martín, Juan Francisco; Fierro, Francisco

    2011-06-01

    Heterotrimeric Gα protein Pga1 of Penicillium chrysogenum controls vegetative growth, conidiation and secondary metabolite production. In this work we studied the role of Pga1 in spore germination and resistance to different stress conditions. Strains G203R-T (expressing the dominant inactivating pga1(G203R) allele) and Δpga1 (deleted pga1) showed a delayed and asynchronic germination pattern, and a decrease in the percentage of germination, which occurred in only 70-80% of the total conidia. In contrast, in strains expressing the dominant activating pga1(G42R) allele, germination occurred at earlier times and in 100% of conidia. In addition, strains with the pga1(G42R) allele were able to bypass the carbon source (glucose or sucrose) requirement for germination in about 64% of conidia. Thus Pga1 plays an important, but not essential, role in germination, mediating carbon source sensing. Regulation of germination by Pga1 is probably mediated by cAMP, as intracellular levels of this secondary messenger undergo a peak before the onset of germination only in strains with an active Pga1. Pga1 activity is also a determinant factor in the resistance to different stress conditions. Absence or inactivation of Pga1 allow growth on SDS-containing minimal medium, increase resistance of conidia to thermal and oxidative stress, and increase resistance of vegetative mycelium to thermal and osmotic stress. In contrast, constitutive activation of Pga1 causes a decrease in the resistance of conidia to thermal stress and of vegetative mycelium to thermal and osmotic stress. Together with our previously reported results, we show in this work that Pga1 plays a central role in the regulation of the whole growth-developmental program of this biotechnologically important fungus.

  11. Use of almond mesocarp for production of the entomopathogenic fungus Verticillium lecanii.

    PubMed

    Lopez-Llorca, L V; Carbonell, T

    1998-09-01

    Almond mesocarp (AM) has been evaluated for production of Verticillium lecanii. Microbial flora of AM has been studied. After ground AM dilution plating, 5.3 x 10(5) +/- 2.6 x 10(4) fungal CFU.g-1 of dry AM were found. Common fungal saprophytes (Rhizopus sp. and Alternaria spp.) were found in more than 80% of the samples. Aspergillus sp. and yeasts were found less commonly. Rhizopus sp., Alternaria spp., and Aspergillus sp. inhibited growth of several V. lecanii; therefore, AM was treated with sterilization agents to eliminate endogenous mycoflora. Small samples (10 g) of AM saturated in distilled water treated with steam (120 degrees C and 100 kPa) were completely sterilized after 15 min. Ground AM incorporated on agar increased the biomass of V. lecanii compared with controls. This suggested AM as suitable substrate for the production of the fungus. In petri dishes, 9.7 x 10(7) +/- 2.9 x 10(7) conidia.g-1 of dry AM were produced after inoculating 10 conidia.g-1 of AM and incubating for 2 weeks. Viability of conidia produced was more than 90%. These conidia (5 x 10(4) conidia per larvae) caused Galleria mellonella mortality, calculated as median lethal time (LT50 5.3 +/- 1.6 days), that was significantly higher (F = 10.93; P < 0.05) than untreated controls (LT50 11.3 +/- 1.1 days). Larger scale tests have to be optimized before mass production.

  12. Cell Wall Modifications during Conidial Maturation of the Human Pathogenic Fungus Pseudallescheria boydii

    PubMed Central

    Ghamrawi, Sarah; Rénier, Gilles; Saulnier, Patrick; Cuenot, Stéphane; Zykwinska, Agata; Dutilh, Bas E.; Thornton, Christopher; Faure, Sébastien; Bouchara, Jean-Philippe

    2014-01-01

    Progress in extending the life expectancy of cystic fibrosis (CF) patients remains jeopardized by the increasing incidence of fungal respiratory infections. Pseudallescheria boydii (P. boydii), an emerging pathogen of humans, is a filamentous fungus frequently isolated from the respiratory secretions of CF patients. It is commonly believed that infection by this fungus occurs through inhalation of airborne conidia, but the mechanisms allowing the adherence of Pseudallescheria to the host epithelial cells and its escape from the host immune defenses remain largely unknown. Given that the cell wall orchestrates all these processes, we were interested in studying its dynamic changes in conidia as function of the age of cultures. We found that the surface hydrophobicity and electronegative charge of conidia increased with the age of culture. Melanin that can influence the cell surface properties, was extracted from conidia and estimated using UV-visible spectrophotometry. Cells were also directly examined and compared using electron paramagnetic resonance (EPR) that determines the production of free radicals. Consistent with the increased amount of melanin, the EPR signal intensity decreased suggesting polymerization of melanin. These results were confirmed by flow cytometry after studying the effect of melanin polymerization on the surface accessibility of mannose-containing glycoconjugates to fluorescent concanavalin A. In the absence of melanin, conidia showed a marked increase in fluorescence intensity as the age of culture increased. Using atomic force microscopy, we were unable to find rodlet-forming hydrophobins, molecules that can also affect conidial surface properties. In conclusion, the changes in surface properties and biochemical composition of the conidial wall with the age of culture highlight the process of conidial maturation. Mannose-containing glycoconjugates that are involved in immune recognition, are progressively masked by polymerization of

  13. Highly virulent Beauveria bassiana strains against the two-spotted spider mite, Tetranychus urticae, show no pathogenicity against five phytoseiid mite species.

    PubMed

    Wu, Shengyong; Xie, Haicui; Li, Maoye; Xu, Xuenong; Lei, Zhongren

    2016-12-01

    Entomopathogenic fungi and predatory mites can independently contribute to suppressing the two-spotted spider mite, Tetranychus urticae Koch. It is important to assess the risk of possible fungal infections in predators when a combination of them are being considered as a tandem control strategy for suppressing T. urticae. The first part of this study tested 12 Beauveria bassiana isolates for virulence in T. urticae. Strains SCWJ-2, SDDZ-9, LNSZ-26, GZGY-1-3 and WLMQ-32 were found to be the most potent, causing 37.6-49.5% adult corrected mortality at a concentration of 1 × 10(7) m/L conidia 4 days post-treatment. The second part evaluated the pathogenicity of these five strains in five species of predatory phytoseiid mites. The bioassay results indicated that all adult predatory mite mortalities ranged from 7.5 to 9.1% 4 days post-treatment. No viable fungal hyphae were found on predator cadavers. Observations with scanning electron microscopy revealed that conidia were attached to the cuticle of predatory mites within 2-12 h after spraying with strain LNSZ-26, and had germinated within 24-36 h. After 48 h, conidia had gradually been shed from the mites, after none of the conidia had penetrated the cuticular surfaces. In contrast, the germinated conidia successfully penetrated the cuticle of T. urticae, and within 60 h the fungus colonized the mite's body. Our study demonstrated that although several B. bassiana strains displayed a high virulence in T. urticae there was no evident pathogenicity to phytoseiid mites. These findings support the potential use of entomopathogenic fungus in combination with predatory mites in T. urticae control programs.

  14. Biocontrol of the Brown-Banded Cockroach, Supella longipalpa F. (Blattaria: Blattellidae), with Entomopathogenic Fungus, Metharhizium anisopliae

    PubMed Central

    Sharififard, Mona; Mossadegh, Mohammad Saeed; Vazirianzadeh, Babak; Latifi, Seyed Mahmood

    2016-01-01

    Background: Considering to the high distribution of cockroaches as urban pests, the efficacy of different formulations of Metarhizium anisopliae strain Iran 437C were assessed against the brown-banded cockroach, Supella longipalpa F. under laboratory and field conditions. Methods: Metarhizium anisopliae isolates were screened with immersing adults of the brown-banded cockroachs in aqueous suspension of 108 conidia ml−1 followed by surface or bait treated with different doses of the most virulent isolate against the nymphs. Then formulations of conidia oil-in-water were examined versus cockroach nymphs using different plant oils and paraffin. Then they were evaluated and compared with aqueous suspension and control group. On a large-scale, the sunflower oil-in-water formulation of conidia was sprayed at houses using a hand sprayer. Results: Metarhizium anisopliae IRAN 437C was the most virulent isolate against the brown-banded cockroach, causing 100% mortality in adults at seven days post-exposure. Inoculated bait with this isolate was not enough pathogenic against the cockroach even at two weeks after treatment. Treated surface with conidia as aqueous suspension or oil-in-water formulation was more effective than the bait formulation against the cockroach caused 39.4–97.2% mortality compared with 2.5% mortality in control group after two days. Spraying the conidia formulated with sunflower oil was an effective formulation causing 76.1% reduction in the cockroach density on the third day post treatment in the houses. Conclusion: The oil-in-water formulation of M. anisopliae IRAN 437C could be recommended as a promising alternative for cockroach control. PMID:27308292

  15. Recognition of a core fragment of Beauveria bassiana hydrophobin gene promoter (P hyd1) and its special use in improving fungal biocontrol potential

    PubMed Central

    Wang, Zheng-Liang; Ying, Sheng-Hua; Feng, Ming-Guang

    2013-01-01

    To identify a suitable promoter for use in engineering fungal entomopathogens to improve heterologous gene expression and fungal biocontrol potential, a 1798 bp promoter (Phyd1) upstream of Beauveria bassiana class I hydrophobin gene (hyd1) was optimized by upstream truncation and site-directed mutation. A truncated 1290 bp fragment (Phyd1-t1) drove eGFP expression in B. bassiana much more efficiently than full-length Phyd1. Further truncating Phyd1-t1 to 1179, 991 and 791 bp or mutating one of the binding domains of three transcription factors in Phyd1-t1 reduced significantly the expression of eGFP (enhanced green fluorescence protein). Under Phyd1-t1 control, eGFP was expressed more abundantly in conidiogenic cells and conidia than in mycelia. Therefore, Phyd1-t1 was used to integrate a bacterium-derived, insect midgut-specific toxin (vip3Aa1) gene into B. bassiana, yielding a transgenic strain (BbHV8) expressing 9.8-fold more toxin molecules in conidia than a counterpart strain (BbV28) expressing the toxin under the control of PgpdA, a promoter widely used for gene expression in fungi. Consequently, BbHV8 showed much higher per os virulence to Spodoptera litura larvae than BbV28 in standardized bioassays with normal conidia for both cuticle penetration and ingestion or heat-killed conidia for ingestion only. Conclusively, Phyd1-t1 is a useful tool for enhancing beneficial protein expression, such as vip3Aa1, in fungal conidia, which are the active ingredients of mycoinsecticides. PMID:22639846

  16. Recognition of a core fragment ofBeauveria bassiana hydrophobin gene promoter (P hyd1) and its special use in improving fungal biocontrol potential.

    PubMed

    Wang, Zheng-Liang; Ying, Sheng-Hua; Feng, Ming-Guang

    2013-01-01

    To identify a suitable promoter for use in engineering fungal entomopathogens to improve heterologous gene expression and fungal biocontrol potential, a 1798 bp promoter (P hyd1) upstream of Beauveria bassiana class I hydrophobin gene (hyd1) was optimized by upstream truncation and site-directed mutation. A truncated 1290 bp fragment (P hyd1-t1) drove eGFP expression in B. bassiana much more efficiently than full-length P hyd1. Further truncating P hyd1-t1 to 1179, 991 and 791 bp or mutating one of the binding domains of three transcription factors in P hyd1-t1 reduced significantly the expression of eGFP (enhanced green fluorescence protein). Under P hyd1-t1 control, eGFP was expressed more abundantly in conidiogenic cells and conidia than in mycelia. Therefore, P hyd1-t1 was used to integrate a bacterium-derived, insect midgut-specific toxin (vip3Aa1) gene into B. bassiana, yielding a transgenic strain (BbHV8) expressing 9.8-fold more toxin molecules in conidia than a counterpart strain (BbV28) expressing the toxin under the control of P gpdA, a promoter widely used for gene expression in fungi. Consequently, BbHV8 showed much higher per os virulence to Spodoptera litura larvae than BbV28 in standardized bioassays with normal conidia for both cuticle penetration and ingestion or heat-killed conidia for ingestion only. Conclusively, P hyd1-t1 is a useful tool for enhancing beneficial protein expression, such as vip3Aa1, in fungal conidia, which are the active ingredients of mycoinsecticides.

  17. Persistence versus Escape: Aspergillus terreus and Aspergillus fumigatus Employ Different Strategies during Interactions with Macrophages

    PubMed Central

    Slesiona, Silvia; Gressler, Markus; Mihlan, Michael; Zaehle, Christoph; Schaller, Martin; Barz, Dagmar; Hube, Bernhard; Jacobsen, Ilse D.; Brock, Matthias

    2012-01-01

    Invasive bronchopulmonary aspergillosis (IBPA) is a life-threatening disease in immunocompromised patients. Although Aspergillus terreus is frequently found in the environment, A. fumigatus is by far the main cause of IBPA. However, once A. terreus establishes infection in the host, disease is as fatal as A. fumigatus infections. Thus, we hypothesized that the initial steps of disease establishment might be fundamentally different between these two species. Since alveolar macrophages represent one of the first phagocytes facing inhaled conidia, we compared the interaction of A. terreus and A. fumigatus conidia with alveolar macrophages. A. terreus conidia were phagocytosed more rapidly than A. fumigatus conidia, possibly due to higher exposure of β-1,3-glucan and galactomannan on the surface. In agreement, blocking of dectin-1 and mannose receptors significantly reduced phagocytosis of A. terreus, but had only a moderate effect on phagocytosis of A. fumigatus. Once phagocytosed, and in contrast to A. fumigatus, A. terreus did not inhibit acidification of phagolysosomes, but remained viable without signs of germination both in vitro and in immunocompetent mice. The inability of A. terreus to germinate and pierce macrophages resulted in significantly lower cytotoxicity compared to A. fumigatus. Blocking phagolysosome acidification by the v-ATPase inhibitor bafilomycin increased A. terreus germination rates and cytotoxicity. Recombinant expression of the A. nidulans wA naphthopyrone synthase, a homologue of A. fumigatus PksP, inhibited phagolysosome acidification and resulted in increased germination, macrophage damage and virulence in corticosteroid-treated mice. In summary, we show that A. terreus and A. fumigatus have evolved significantly different strategies to survive the attack of host immune cells. While A. fumigatus prevents phagocytosis and phagolysosome acidification and escapes from macrophages by germination, A. terreus is rapidly phagocytosed, but

  18. Responses of antioxidant defenses to Cu and Zn stress in two aquatic fungi.

    PubMed

    Azevedo, Maria-Manuel; Carvalho, Agostinho; Pascoal, Cláudia; Rodrigues, Fernando; Cássio, Fernanda

    2007-05-15

    Aquatic hyphomycetes are fungi that play a key role in plant litter decomposition in streams. Even though these fungi occur in metal-polluted streams, the mechanisms underlying their tolerance to metals are poorly documented. We addressed the effects of Zn and Cu in Varicosporium elodeae and Heliscus submersus by examining metal adsorption to cell walls, plasma membrane integrity and production of reactive oxygen species at metal concentrations inhibiting biomass production in 50% or 80%. The activity of the enzymes catalase, superoxide dismutase and glucose-6-phosphate dehydrogenase was measured to elucidate their role in coping with oxidative stress induced by metals at short- (14 h) and long- (8 days) term exposure. Results show that V. elodeae was more susceptible to the toxic effects induced by Cu and Zn than H. submersus, as indicated by more extensive inhibition of biomass production. Both metals, particularly Cu, induced oxidative stress in the two fungal species, as shown by the noticeable recovery of biomass production in the presence of an antioxidant agent. In both fungi, Cu induced a more severe disruption of plasma membrane integrity than Zn. Our studies on antioxidant defenses showed that catalase had a greater role alleviating stress induced by Zn and Cu than superoxide dismutase. Chronic metal stress also stimulated the production of NADPH, via the pentose phosphate pathway by increasing the activity of glucose-6-phosphate dehydrogenase. Our results suggest that the tolerance of aquatic hyphomycetes to Cu and Zn is associated with the ability of these fungi to initiate an efficient antioxidant defense system.

  19. Infection-Mediated Priming of Phagocytes Protects against Lethal Secondary Aspergillus fumigatus Challenge

    PubMed Central

    Savers, Amélie; Rasid, Orhan; Parlato, Marianna; Brock, Matthias; Jouvion, Gregory; Ryffel, Bernhard; Cavaillon, Jean-Marc; Eberl, Gerard; Ibrahim-Granet, Oumaïma

    2016-01-01

    Phagocytes restrict the germination of Aspergillus fumigatus conidia and prevent the establishment of invasive pulmonary aspergillosis in immunecompetent mice. Here we report that immunecompetent mice recovering from a primary A. fumigatus challenge are protected against a secondary lethal challenge. Using RAGγc knock-out mice we show that this protection is independent of T, B and NK cells. In protected mice, lung phagocytes are recruited more rapidly and are more efficient in conidial phagocytosis and killing. Protection was also associated with an enhanced expression of CXCR2 and Dectin-1 on bone marrow phagocytes. We also show that protective lung cytokine and chemokine responses are induced more rapidly and with enhanced dynamics in protected mice. Our findings support the hypothesis that following a first encounter with a non-lethal dose of A. fumigatus conidia, the innate immune system is primed and can mediate protection against a secondary lethal infection. PMID:27078879

  20. Conidiobolus macrosporus (Entomophthorales), a mosquito pathogen in Central Brazil.

    PubMed

    Montalva, Cristian; Rocha, Luiz F N; Fernandes, Éverton K K; Luz, Christian; Humber, Richard A

    2016-09-01

    A new fungal pathogen of Culicinae (Diptera: Culicidae) adults, Conidiobolus macrosporus (Entomophthorales: Ancylistaceae), was detected and isolated during a survey of mosquito pathogens close to the city of Aruanã, Goiás State, in December 2014. The morphological characteristics of C. macrosporus are presented, and reasons for some uncertainty about this identification are discussed. The pathogenicity and high virulence of this fungus for Aedes aegypti were confirmed in laboratory conditions. Mortality of adults exposed to conidia was observed within 24h of exposure to the pathogen, and increased to 100% as quickly as 3days after inoculation (with the highest conidial concentration tested, 8.3×10(4)conidia/cm(2)). Repeated attempts to obtain genomic sequence data failed despite confirmations that the DNA extraction methods were themselves successful.

  1. Biomechanics of conidial dispersal in the toxic mold Stachybotrys chartarum.

    PubMed

    Tucker, Kathryn; Stolze, Jessica L; Kennedy, Aaron H; Money, Nicholas P

    2007-07-01

    Conidial dispersal in Stachybotrys chartarum in response to low-velocity airflow was studied using a microflow apparatus. The maximum rate of spore release occurred during the first 5 min of airflow, followed by a dramatic reduction in dispersal that left more than 99% of the conidia attached to their conidiophores. Micromanipulation of undisturbed colonies showed that micronewton (microN) forces were needed to dislodge spore clusters from their supporting conidiophores. Calculations show that airspeeds that normally prevail in the indoor environment disturb colonies with forces that are 1000-fold lower, in the nanonewton (nN) range. Low-velocity airflow does not, therefore, cause sufficient disturbance to disperse a large proportion of the conidia of S. chartarum.

  2. Fusarium dactylidis sp. nov., a novel nivalenol toxin-producing species sister to F. pseudograminearum isolated from orchard grass (Dactylis glomerata) in Oregon and New Zealand.

    PubMed

    Aoki, Takayuki; Vaughan, Martha M; McCormick, Susan P; Busman, Mark; Ward, Todd J; Kelly, Amy; O'Donnell, Kerry; Johnston, Peter R; Geiser, David M

    2015-01-01

    The B trichothecene toxin-producing clade (B clade) of Fusarium includes the etiological agents of Fusarium head blight, crown rot of wheat and barley and stem and ear rot of maize. B clade isolates also have been recovered from several wild and cultivated grasses, including Dactylis glomerata (orchard grass or cock's foot), one of the world's most important forage grasses. Two isolates from the latter host are formally described here as F. dactylidis. Phenotypically F. dactylidis most closely resembles F. ussurianum from the Russian Far East. Both species produce symmetrical sporodochial conidia that are similar in size and curved toward both ends. However, conidia of F. ussurianum typically end in a narrow apical beak while the apical cell of F. dactylidis is acute. Fusarium dactylidis produced nivalenol mycotoxin in planta as well as low but detectable amounts of the estrogenic mycotoxin zearalenone in vitro. Results of a pathogenicity test revealed that F. dactylidis induced mild head blight on wheat.

  3. Protein analysis in a pleomorphically deteriorated strain of the insect-pathogenic fungus Metarhizium anisopliae.

    PubMed

    Kamp, Andrena M; Bidochka, Michael J

    2002-09-01

    Pleomorphic deterioration is a process where a fungal isolate loses the ability to produce conidia during repeated subculturing. We have previously isolated strains of the entomopathogenic fungus Metarhizium anisopliae that have irreversibly lost the ability to produce conidia and only produce mycelia when grown on agar. Gel electrophoresis was used to examine differences in intracellular protein patterns (urea-soluble proteins and urea-insoluble proteins (i.e., hydrophobins)) in conidiating and mycelial cultures of M. anisopliae. Two major proteins present in a conidiating culture and one from a mycelial culture were N-terminally sequenced but showed no homologies to known proteins. The presence of hydrophobins in conidiating and mycelial cultures was also examined, and it was shown that these proteins were abundant in conidiating cultures but not in mycelial cultures. We also used primers designed from regulatory genes involved in conidiation in Aspergillus nidulans. The amplified fragments were not homologous to A. nidulans genes.

  4. Comparative efficacy and pathogenicity of keratinophilic soil fungi against Culex quinquefasciatus larvae.

    PubMed

    Mohanty, Suman Sundar; Prakash, Soam

    2010-09-01

    Out of seven fungal species belonging to four genera isolated from pond and wallow soils using feathers of Pavo cristatus as bait, four species viz., Aspergillus flavus, Aspergillus niger, Chrysosporium pseudomerdarium and Trichophyton ajelloi were most frequent. Chrysosporium and Trichophyton spp. were more pathogenic on Culex quinquefasciatus larvae than Aspergillus and Penicillium. The bioefficacy tests conducted as per the protocol of World Health Organization and the LC(50) values calculated by the Probit analysis showed that 3(rd)-instar C. quinquefasciatus were more susceptible to the conidia of above fungi. Highest mortality was observed in the larvae of C. quinquefasciatus when exposed to T. ajelloi. The density of fungal conidia was greatest on the ventral brush, palmate hair and anal region of the mosquito larvae after exposing for 72 hours. The potentiality of these fungi for use in the control of C. quinquefasciatus is discussed which can be exploited as a suitable biocontrol agent in the tropics.

  5. Antifungal Activity of a Synthetic Cationic Peptide against the Plant Pathogens Colletotrichum graminicola and Three Fusarium Species.

    PubMed

    Johnson, Eric T; Evans, Kervin O; Dowd, Patrick F

    2015-09-01

    A small cationic peptide (JH8944) was tested for activity against a number of pathogens of agricultural crops. JH8944 inhibited conidium growth in most of the tested plant pathogens with a dose of 50 μg/ml, although one isolate of Fusarium oxysporum was inhibited at 5 μg/ml of JH8944. Most conidia of Fusarium graminearum were killed within 6 hours of treatment with 50 μg/ml of JH8944. Germinating F. graminearum conidia required 238 μg/ml of JH8944 for 90% growth inhibition. The peptide did not cause any damage to tissues surrounding maize leaf punctures when tested at a higher concentration of 250 μg/ml even after 3 days. Liposomes consisting of phosphatidylglycerol were susceptible to leakage after treatment with 25 and 50 μg/ml of JH8944. These experiments suggest this peptide destroys fungal membrane integrity and could be utilized for control of crop fungal pathogens.

  6. Sensitivity ofBeauveria bassiana to solanine and tomatine : Plant defensive chemicals inhibit an insect pathogen.

    PubMed

    Costa, S D; Gaugler, R R

    1989-02-01

    The alkaloids solanine and tomatine and the polyene antibiotic nystatin were tested in vitro against the entomopathogenic fungusBeauveria bassiana. Nystatin was the most inhibitory compound tested, reducing colony formation, growth, and development of conidiaphores to a greater degree and at lower concentrations than the alkaloids. Tomatine inhibited colony formation and growth more than solanine, which had relatively little effect on the fungus. The toxicity of tomatine suggests that germination of conidia and subsequent hyphal growth would be inhibited when an insect consumes conidia along with foliage containing 0.100 mg/g (fresh weight) of this compound. The sensitivity ofB. bassiana to alkaloids appears to be in the middle of the range found with other fungi.

  7. Conidium Germination Rate in Wild and Domesticated Yellow-Green Aspergilli

    PubMed Central

    Wicklow, D. T.

    1984-01-01

    Conidia of domesticated yellow-green aspergilli from strains of Aspergillus oryzae (Ahlburg) Cohn and Aspergillus sojae Sakaguchi and Yamada ex Murakami, used in the preparation of koji inoculum, germinate approximately 3 h sooner than conidia produced by related wild species, Aspergillus flavus Link ex Fr. and Aspergillus parasiticus Speare. There was no consistent relationship between average conidium size and estimated 50% germination time. Germination trials were conducted on Czapek agar at 28°C. A hypothesis is offered that, in the propagation of koji inoculum, selection has favored those individuals capable of rapid conidium germination and germ tube extension, attributes that enable them to gain the available substrate during intraspecific competition. PMID:16346471

  8. Extreme dryness and DNA-protein cross-links

    NASA Astrophysics Data System (ADS)

    Bieger-Dose, A.; Dose, K.; Meffert, R.; Mehler, M.; Risi, S.

    Exposure of fungal conidia (Aspergillus ochraceus) or spores of Bacillus subtilis to extreme dryness or vacuum induces DNA lesions, including strand breaks and the formation of DNA-protein cross-links. In wet cells only a small amount of protein is bound to DNA, but exposure to conditions of lowered water activity results in an increasing number of cross-links between DNA and proteins. In fungal conidia these cross-links are detected after selective iodination (125J) of the DNA-bound proteins followed by gel electrophoresis and subsequent autoradiography. Another approach is the labelling of DNA with 32p by means of nick translation and the detection of differences in the electrophoretic mobility of DNA before and after digestion with proteinase K of proteins bound to DNA.

  9. Purification of Candida guilliermondii and Pichia ohmeri killer toxin as an active agent against Penicillium expansum.

    PubMed

    Coelho, Alexandre Rodrigo; Tachi, Masahico; Pagnocca, Fernando Carlos; Nobrega, Gisele Maria Andrade; Hoffmann, Fernando Leite; Harada, Ken-Ichi; Hirooka, Elisa Yoko

    2009-01-01

    An antifungal assay with cell-free culture supernatant of Pichia ohmeri 158 and Candida guilliermondii P3 was tested against Penicillium expansum strain #2 at 25 degrees C by measuring hyphal length and percentage conidia germination. C. guilliermondii was more effective against P. expansum conidia germination (58.15% inhibition), while P. ohmeri showed higher inhibition of mycelial growth (66.17%), indicating a probable mechanism associated with killer activity. This killer toxin (molecular mass <3 kDa) was partially purified by normal phase HPLC, using TSKgel Amide-80 analytical and preparative columns. Compared with crude extract, the killer toxin eluted from the post analytical column significantly inhibited P. expansum:% inhibition rose from 42.16 to 90.93% (C. guilliermondii) and 39.32 to 91.12% (P. ohmeri) (p < 0.05). The one-step purification process was adequate in isolating killer toxin from culture supernatant and also increased anti-Penicillium activity.

  10. Morphogenetic circuitry regulating growth and development in the dimorphic pathogen Penicillium marneffei.

    PubMed

    Boyce, Kylie J; Andrianopoulos, Alex

    2013-02-01

    Penicillium marneffei is an emerging human-pathogenic fungus endemic to Southeast Asia. Like a number of other fungal pathogens, P. marneffei exhibits temperature-dependent dimorphic growth and grows in two distinct cellular morphologies, hyphae at 25°C and yeast cells at 37°C. Hyphae can differentiate to produce the infectious agents, asexual spores (conidia), which are inhaled into the host lung, where they are phagocytosed by pulmonary alveolar macrophages. Within macrophages, conidia germinate into unicellular yeast cells, which divide by fission. This minireview focuses on the current understanding of the genes required for the morphogenetic control of conidial germination, hyphal growth, asexual development, and yeast morphogenesis in P. marneffei.

  11. Changes in the physiological properties and kinetics of citric acid accumulation via carbon ion irradiation mutagenesis of Aspergillus niger *

    PubMed Central

    Hu, Wei; Chen, Ji-hong; Wang, Shu-yang; Liu, Jing; Song, Yuan; Wu, Qing-feng; Li, Wen-jian

    2016-01-01

    The objective of this work was to produce citric acid from corn starch using a newly isolated mutant of Aspergillus niger, and to analyze the relationship between changes in the physiological properties of A. niger induced by carbon ion irradiation and citric acid accumulation. Our results showed that the physiological characteristics of conidia in A. niger were closely related to citric acid accumulation and that lower growth rate and viability of conidia may be beneficial to citric acid accumulation. Using corn starch as a raw material, a high-yielding citric acid mutant, named HW2, was obtained. In a 10-L bioreactor, HW2 can accumulate 118.9 g/L citric acid with a residual total sugar concentration of only 14.4 g/L. This represented an 18% increase in citric acid accumulation and a 12.5% decrease in sugar utilization compared with the original strain.

  12. Regulation and specificity of antifungal metapleural gland secretion in leaf-cutting ants.

    PubMed

    Yek, Sze Huei; Nash, David R; Jensen, Annette B; Boomsma, Jacobus J

    2012-10-22

    Ants have paired metapleural glands (MGs) to produce secretions for prophylactic hygiene. These exocrine glands are particularly well developed in leaf-cutting ants, but whether the ants can actively regulate MG secretion is unknown. In a set of controlled experiments using conidia of five fungi, we show that the ants adjust the amount of MG secretion to the virulence of the fungus with which they are infected. We further applied fixed volumes of MG secretion of ants challenged with constant conidia doses to agar mats of the same fungal species. This showed that inhibition halos were significantly larger for ants challenged with virulent and mild pathogens/weeds than for controls and Escovopsis-challenged ants. We conclude that the MG defence system of leaf-cutting ants has characteristics reminiscent of an additional cuticular immune system, with specific and non-specific components, of which some are constitutive and others induced.

  13. Upper boundary of the biosphere.

    PubMed Central

    Imshenetsky, A A; Lysenko, S V; Kazakov, G A

    1978-01-01

    By using meterological rockets fitted with specially designed analyzers, samples for microbiological investigation have been taken. The analyzer design prevented extraneous microorganisms from penetrating into the analyzer. Before being used, the analyzers were sterilized with high gamma-ray doses. For the first time microorganisms have been detected in the mesosphere at an altitude of 48 to 77 km. The microorganisms are microscopic fungi having black conidia or spores (Circinella muscae, Aspergillus niger, Papulaspora anomala) and one species forming green conidia (Penicillium notatum). Colonies of Mycobacterium luteum and Micrococcus albus have also grown. Five of the six species have synthesized pigments. The presence of pigmented microbial forms leads us to believe that natural selection is occurring in the mesosphere because cells possessing chromogenous pigments (carotenoids, melanins) are more resistant to ultraviolet-ray action. A greater number of microorganisms have been registered in the mesosphere during dust storms than in the absence of strong winds. Images PMID:623455

  14. Biomechanics of conidial dispersal in the toxic mold Stachybotrys chartarum

    PubMed Central

    Tucker, Kathryn; Stolze, Jessica L.; Kennedy, Aaron H.; Money, Nicholas P.

    2007-01-01

    Conidial dispersal in Stachybotrys chartarum in response to low-velocity airflow was studied using a microflow apparatus. The maximum rate of spore release occurred during the first 5 min of airflow, followed by a dramatic reduction in dispersal that left more than 99% of the conidia attached to their conidiophores. Micromanipulation of undisturbed colonies showed that micronewton (μN) forces were needed to dislodge spore clusters from their supporting conidiophores. Calculations show that airspeeds that normally prevail in the indoor environment disturb colonies with forces that are 1,000-fold lower, in the nanonewton (nN) range. Low-velocity airflow does not, therefore, cause sufficient disturbance to disperse a large proportion of the conidia of S. chartarum. PMID:17267247

  15. Automated image analysis of the host-pathogen interaction between phagocytes and Aspergillus fumigatus.

    PubMed

    Mech, Franziska; Thywissen, Andreas; Guthke, Reinhard; Brakhage, Axel A; Figge, Marc Thilo

    2011-05-05

    Aspergillus fumigatus is a ubiquitous airborne fungus and opportunistic human pathogen. In immunocompromised hosts, the fungus can cause life-threatening diseases like invasive pulmonary aspergillosis. Since the incidence of fungal systemic infections drastically increased over the last years, it is a major goal to investigate the pathobiology of A. fumigatus and in particular the interactions of A. fumigatus conidia with immune cells. Many of these studies include the activity of immune effector cells, in particular of macrophages, when they are confronted with conidia of A. fumigus wild-type and mutant strains. Here, we report the development of an automated analysis of confocal laser scanning microscopy images from macrophages coincubated with different A. fumigatus strains. At present, microscopy images are often analysed manually, including cell counting and determination of interrelations between cells, which is very time consuming and error-prone. Automation of this process overcomes these disadvantages and standardises the analysis, which is a prerequisite for further systems biological studies including mathematical modeling of the infection process. For this purpose, the cells in our experimental setup were differentially stained and monitored by confocal laser scanning microscopy. To perform the image analysis in an automatic fashion, we developed a ruleset that is generally applicable to phagocytosis assays and in the present case was processed by the software Definiens Developer XD. As a result of a complete image analysis we obtained features such as size, shape, number of cells and cell-cell contacts. The analysis reported here, reveals that different mutants of A. fumigatus have a major influence on the ability of macrophages to adhere and to phagocytose the respective conidia. In particular, we observe that the phagocytosis ratio and the aggregation behaviour of pksP mutant compared to wild-type conidia are both significantly increased.

  16. Effects of hydrophilic and hydrophobic kaolin-based particle films on pea aphid (Homoptera: Aphididae) and its entomopathogen Pandora neoaphidis (Entomophthorales: Entomophthoraceae).

    PubMed

    Eigenbrode, Sanford D; Ding, Hongjian; Neufeld, Jeffrey; Duetting, Patrick

    2006-02-01

    Hydrophobic and hydrophilic kaolin-based particle films are effective for control of insect pests in certain agricultural crops. How these products interact with potential biological control agents is not well documented. This study was conducted to evaluate the effects of the hydrophobic (M96-018) and hydrophilic (Surround WP) kaolin-based particle films (Engelhard Corporation, Iselin, NJ) on pea aphid, Acyrthosiphon pisum (Harris), on peas (Pisum spp.), and on the fungal aphid pathogen Pandora neoaphidis (Remaudière and Hennebert) Humber. Over two field seasons (2001 and 2002) in northern Idaho, applications of M96-018 significantly reduced the rate of pea aphid increase on pea, but Surround WP, tested only in 2001, did not reduce aphid population growth rate. Neither particle film treatment was as effective as a standard application of esfenvalerate (DuPont Asana). In the laboratory, particle films suppressed pea aphid populations by up to 30%. M96-018 seemed to have some repellent activity based on aphid distributions after treating plants. When applied along with P. neoaphidis conidia, M96-018 but not Surround WP caused higher percentage of infection mortality of pea aphids by P. neoaphidis than occurred on controls treated only with P. neoaphidis conidia. P. neoaphidis conidia deposited on glass slides coated with M96-018, produced more germ tubes and secondary conidia than those deposited on untreated glass slides or slides treated with Surround WP. This result suggests that greater infection of pea aphids on plants treated with M96-018 is in part a result of a direct enhancement of fungal germination by the particle film.

  17. Biosynthesis and Functions of Melanin in Sporothrix schenckii

    PubMed Central

    Romero-Martinez, Rafael; Wheeler, Michael; Guerrero-Plata, Antonieta; Rico, Guadalupe; Torres-Guerrero, Haydée

    2000-01-01

    Sporothrix schenckii is a human pathogen that causes sporotrichosis, an important cutaneous mycosis with a worldwide distribution. It produces dark-brown conidia, which infect the host. We found that S. schenckii synthesizes melanin via the 1,8-dihydroxynaphthalene pentaketide pathway. Melanin biosynthesis in the wild type was inhibited by tricyclazole, and colonies of the fungus were reddish brown instead of black on tricyclazole-amended medium. Two melanin-deficient mutant strains were analyzed in this study: an albino that produced normal-appearing melanin on scytalone-amended medium and a reddish brown mutant that accumulated and extruded melanin metabolites into its medium. Scytalone and flaviolin obtained from cultures of the reddish brown mutant were identified by thin-layer chromatography, high-performance liquid chromatography, and UV spectra. Transmission electron microscopy showed an electron-dense granular material believed to be melanin in wild-type conidial cell walls, and this was absent in conidial walls of the albino mutant unless the albino was grown on a scytalone-amended medium. Melanized cells of wild-type S. schenckii and the albino grown on scytalone-amended medium were less susceptible to killing by chemically generated oxygen- and nitrogen-derived radicals and by UV light than were conidia of the mutant strains. Melanized conidia of the wild type and the scytalone-treated albino were also more resistant to phagocytosis and killing by human monocytes and murine macrophages than were unmelanized conidia of the two mutants. These results demonstrate that melanin protects S. schenckii against certain oxidative antimicrobial compounds and against attack by macrophages. PMID:10816530

  18. Morphogenetic Alterations of Alternaria alternata Exposed to Dicarboximide Fungicide, Iprodione

    PubMed Central

    Kim, Eunji; Lee, Hye Min; Kim, Young Ho

    2017-01-01

    Fungicide-resistant Alternaria alternata impede the practical control of the Alternaria diseases in crop fields. This study aimed to investigate cytological fungicide resistance mechanisms of A. alternata against dicarboximide fungicide iprodione. A. alternata isolated from cactus brown spot was cultured on potato-dextrose agar (PDA) with or without iprodione, and the fungal cultures with different growth characteristics from no, initial and full growth were observed by light and electron microscopy. Mycelia began to grow from one day after incubation (DAI) and continued to be in full growth (control-growth, Con-G) on PDA without fungicide, while on PDA with iprodione, no fungal growth (iprodione-no growth, Ipr-N) occurred for the first 3 DAI, but once the initial growth (iprodione-initial growth, Ipr-I) began at 4–5 DAI, the colonies grew and expanded continuously to be in full growth (iprodione-growth, Ipr-G), suggesting Ipr-I may be a turning moment of the morphogenetic changes resisting fungicidal toxicity. Con-G formed multicellular conidia with cell walls and septa and intact dense cytoplasm. In Ipr-N, fungal sporulation was inhibited by forming mostly undeveloped unicellular conidia with degraded and necrotic cytoplasm. However, in Ipr-I, conspicuous cellular changes occurred during sporulation by forming multicellular conidia with double layered (thickened) cell walls and accumulation of proliferated lipid bodies in the conidial cytoplasm, which may inhibit the penetration of the fungicide into conidial cells, reducing fungicide-associated toxicity, and may be utilized as energy and nutritional sources, respectively, for the further fungal growth to form mature colonies as in Ipr-G that formed multicellular conidia with cell walls and intact cytoplasm with lipid bodies as in Con-G. PMID:28167893

  19. Plant waxy bloom on peas affects infection of pea aphids by Pandora neoaphidis.

    PubMed

    Duetting, Patrick S; Ding, Hongjian; Neufeld, Jeffrey; Eigenbrode, Sanford D

    2003-11-01

    This study examined the effects of the surface wax bloom of pea plants, Pisum sativum, on infection of pea aphids, Acyrthosiphon pisum, by the fungal pathogen Pandora neoaphidis. In prior field surveys, a higher proportion of P. neoaphidis-killed pea aphids (cadavers) had been observed on a pea line with reduced wax bloom, as compared with a sister line with normal surface wax bloom. Laboratory bioassays were conducted in order to examine the mechanisms. After plants of each line infested with aphids were exposed to similar densities of conidia, the rate of accumulation of cadavers on the reduced wax line was significantly greater than on the normal wax bloom line; at the end of the experiment (13d), the proportion of aphid cadavers on the reduced wax line was approximately four times that on the normal wax bloom line. When plants were exposed to conidia first and then infested with aphids, the rate of accumulation of cadavers was slightly but significantly greater on the reduced wax line, and infection at the end of the experiment (16d) did not differ between the lines. When aphids were exposed first and then released onto the plants, no differences in the proportion of aphid cadavers were observed between the pea lines. Greater infection of pea aphid on reduced wax peas appears to depend upon plants being exposed to inoculum while aphids are settled in typical feeding positions on the plant. Additional experiments demonstrated increased adhesion and germination by P. neoaphidis conidia to leaf surfaces of the reduced wax line as compared with normal wax line, and this could help explain the higher infection rate by P. neoaphidis on the reduced wax line. In bioassays using surface waxes extracted from the two lines, there was no effect of wax source on germination of P. neoaphidis conidia.

  20. Influence of Lectins on Constricting Ring Formation by Arthrobotrys dactyloides.

    PubMed

    Kaplan, D T; Davis, E L; Walter, D E

    1991-04-01

    Incubation of Arthrobotrys dactyloides conidia in the presence of Radopholus citrophilus in lectin solutions with their corresponding sugars did not alter the stimulation of trap formation in solutions containing lectins alone. The lack of inhibition of lectin-stimulated trap formation by sugars or by lectin denaturation and the lack of lectin specificity indicate that the carbohydrate-binding regions of the particular lectins studied are not the stimulatory moieties of these macromolecules.

  1. Environmental Monitoring for Aspergillus fumigatus in Association with an Immunosuppressed Rabbit Model of Pulmonary Aspergillosis

    PubMed Central

    Such, Kimberly A; Petraitis, Vidmantas; Petraitiene, Ruta; Strauss, Gittel E; Moradi, Patriss-Wais; Walsh, Thomas J

    2013-01-01

    Aspergillus fumigatus causes life-threatening pneumonia in immunocompromised patients. Conidia, the infectious form of the organism, are handled in a biologic safety cabinet under BSL2 conditions. However because germinated conidia form noninfectious hyphae in tissue, we hypothesized that rabbits inoculated intratracheally would grow A. fumigatus in their lungs but that the environment would remain free of this fungus, potentially permitting maintenance of infected animals under ABSL1 conditions. We performed a surveillance study for the presence of A. fumigatus in the environment before proceeding with antifungal therapy studies of experimental pulmonary aspergillosis. The expected outcome included absence of A. fumigatus in the environment, stool, and blood and presence in rabbit lungs. Female SPF New Zealand white rabbits were immunosuppressed and inoculated intratracheally (n = 4) or intraesophageally (n = 2) with 1.25 × 108 conidia of A. fumigatus. Feces, pan liners, and walls were sampled daily during the 11-d experiment, and blood was sampled on days 2, 6, and 8 after inoculation. Samples were cultured on 5% Sabouraud glucose agar plates. Lungs were weighed and scored for hemorrhagic infarcts and homogenized for culture on 5% Sabouraud glucose agar and trypticase soy agar plates. Blood cultures, rabbit stool, and environmental swabs were all negative for A. fumigatus whereas the lungs inoculated intratracheally demonstrated 4.5 × 102 ± 0.8 × 102 CFU/g of A. fumigatus. Therefore, neutropenic rabbits with experimental invasive pulmonary aspergillosis do not shed conidia of A. fumigatus and can be safely housed under ABSL1 conditions after inoculation. PMID:24041208

  2. A re-evaluation of the genus Myceliophthora (Sordariales, Ascomycota): its segregation into four genera and description of Corynascus fumimontanus sp. nov.

    PubMed

    Marin-Felix, Yasmina; Stchigel, Alberto M; Miller, Andrew N; Guarro, Josep; Cano-Lira, José F

    2015-01-01

    Based on a number of isolates of Myceliophthora (Chaetomiaceae, Sordariales, Ascomycota) recently isolated from soil samples collected in USA, the taxonomy of the genus was re-evaluated through phylogenetic analyses of sequences from the nuc rDNA internal transcribed spacer region and genes for the second largest subunit of RNA polymerase II and translation elongation factor 1α. Members of Myceliophthora were split into four monophyletic clades strongly supported by molecular and phenotypic data. Such clades correspond with Myceliophthora, now restricted only to the type species of the genus Corynascus, which is re-established with five species, the new monotypic genus Crassicarpon and also the new genus Thermothelomyces (comprising four species). Myceliophthora lutea is mesophilic and a permanently asexual morph compared to the members of the other three mentioned genera, which also are able to sexually reproduce morphs with experimentally proven links to their asexual morphs. The asexual morph of M. lutea is characterized by broadly ellipsoidal, smooth-walled conidia with a wide, truncate base. Crassicarpon thermophilum is thermophilic and heterothallic and produces spherical to cuneiform, smooth-walled conidia and cleistothecial ascomata of smooth-walled, angular cells and ascospores with a germ pore at each end. Corynascus spp. are homothallic and mesophilic and produce spherical, mostly ornamented conidia and cleistothecial ascomata with textura epidermoidea composed of ornamented wall cells, and ascospores with one germ pore at each end. Thermothelomyces spp. are thermophilic, heterothallic and characterized by similar ascomata and conidia as Corynascus spp., but its ascospores exhibit only a single germ pore. A dichotomous key to distinguish Myceliophthora from the other mentioned genera are provided, as well as dichotomous keys to identify the species of Corynascus and Thermothelomyces. A new species, namely Corynascus fumimontanus, characterized by

  3. Apollo MEED mycology revisited and reviewed, including the Trichophyton terrestre keratinophilic growth at splashdown and 23 years after exposure to space parameters.

    PubMed

    Volz, P A; Long, J D; Veselenak, J M

    1995-01-01

    Keratinophilic Trichophyton terrestre conidia were exposed to selected parameters of space flight including 254, 280 and 300 nm UV light, full light and total darkness of space. Phenotypic isolates were grown on human hair collected from one source at years 1 and 23 after splashdown. The patterns of fungal growth on the hair, and the hair deterioration rates, were noted according to the space exposure. Growth and deterioration were consistent but slightly reduced at year 23.

  4. Sprays of emulsifiable Beauveria bassiana formulation are ovicidal towards Tetranychus urticae (Acari: Tetranychidae) at various regimes of temperature and humidity.

    PubMed

    Shi, Wei-Bing; Feng, Ming-Guang; Liu, Shu-Sheng

    2008-12-01

    Aerial conidia of Beauveria bassiana in an emulsifiable formulation germinated by >95% after 24 h exposure to the regimes of 20, 25 and 30 degrees C with 51%, 74% and 95% RH. Ovicidal activities of the formulation towards two-spotted spider mite, Tetranychus urticae, were assayed at the concentrations of 0, 18, 160 and 693 conidia mm(-2) sprayed separately onto fava bean leaves including 39 (25-76) eggs per capita. All the sprayed eggs on the leaves were directly exposed to the different regimes for hatch after 24 h maintenance in covered Petri dishes. Generally, hatched proportions increased over post-spray days and decreased with the elevated fungal concentrations; no more eggs hatched from day 9 or 10 onwards. Based on the counts of the hatched/non-hatched eggs in the different regimes, the final egg mortalities were 15.0-40.4%, 48.9-66.6% and 62.9-87.5% at the low, medium and high concentrations, respectively, but only 5.6-11.3% in blank controls. The RH effect on the fungal action was significant at 20 and 25 degrees C but not at 30 degrees C whereas the effect of temperature was significant at 51% and 74% RH but not at 95% RH. Probit analysis of the egg mortalities versus the fungal sprays generated median lethal concentrations (LC(50)) of 65-320 conidia mm(-2) at all the regimes, and of only 65-78 conidia mm(-2) at 25-30 degrees C with 74-95% RH. The results highlight ovicidal activities of the emulsifiable formulation against the mite species at the tested regimes and its potential use in spider mite control.

  5. Metarhizium anisopliae conidial responses to lipids from tick cuticle and tick mammalian host surface.

    PubMed

    Ment, Dana; Gindin, Galina; Soroker, Victoria; Glazer, Itamar; Rot, Asael; Samish, Michael

    2010-02-01

    Conidial germination and the formation of appressoria are important events in the interactions between entomopathogenic fungi and their arthropod hosts. In this study, we demonstrate the effects of lipids extracted from tick epicuticle and the surface of a mammalian host (calf) on conidial germination and the development of appressoria in two subspecies of Metarhizium anisopliae, M. anisopliae var. anisopliae (M.an.an.-7) and M. anisopliae var. acridum (M.an.ac.-5), which have different levels of virulence toward ticks. Pentane extracts of epicuticles of ticks susceptible and resistant to fungal infection always stimulated the germination of M.an.an.-7 conidia and the development of their appressoria; whereas the effects of dichloromethane (DCM) extracts of tick epicuticle varied depending on the tick. The DCM extracts from most of the tick species and developmental stages stimulated conidial germination and/or the formation of appressoria in M.an.an.-7. However, a DCM extract of lipids from the most resistant tick, engorged Hyalomma excavatum female, inhibited the germination of M.an.an.-7 conidia. Conidia of the non-virulent M.an.ac.-5 did not germinate on agarose amended with any of the examined tick extracts. However, when the tick extracts were placed on bactoagar, conidial germination increased 7- to 8-fold. Extracts from the skin, hair and ear secretions of a calf stimulated conidial germination and the formation of appressoria in M.an.an.-7, but not M.an.ac.-5. This study demonstrates that lipids from tick epicuticles and mammalian skin selectively affect the germination of conidia of entomopathogenic fungi. The effects of these lipids may explain the variability in tick control these fungi provide for different hosts.

  6. Testing anti-fungal activity of a soil-like substrate for growing plants in bioregenerative life support systems

    NASA Astrophysics Data System (ADS)

    Nesterenko, E. V.; Kozlov, V. A.; Khizhnyak, S. V.; Manukovsky, N. S.; Kovalev, V. S.; Gurevich, Yu. L.; Liu, Hong; Xing, Yidong; Hu, Enzhu

    2009-10-01

    The object of this research is to study a soil-like substrate (SLS) to grow plants in a Bioregenerative Life Support System (BLSS). Wheat and rice straw were used as raw materials to prepare SLS. Anti-fungal activity of SLS using test cultures of Bipolaris sorokiniana, a plant-pathogenic fungus which causes wheat root rot was studied. Experiments were conducted with SLS samples, using natural soil and sand as controls. Infecting the substrates, was performed at two levels: the first level was done with wheat seeds carrying B. sorokiniana and the second level with seeds and additional conidia of B. sorokiniana from an outside source. We measured wheat disease incidence and severity in two crop plantings. Lowest disease incidence values were obtained from the second planting, SLS: 26% and 41% at the first and the second infection levels, respectively. For soil the values were 60% and 82%, respectively, and for sand they were 67% and 74%, respectively. Wheat root rot in the second crop planting on SLS, at both infection levels was considerably less severe (9% and 13%, respectively) than on natural soil (20% and 33%) and sand (22% and 32%). SLS significantly suppressed the germination of B. sorokiniana conidia. Conidia germination was 5% in aqueous SLS suspension, and 18% in clean water. No significant differences were found regarding the impact on conidia germination between the SLS samples obtained from wheat and rice straw. The anti-fungal activity in SLS increased because of the presence of worms. SLS also contained bacteria stimulating and inhibiting B. sorokiniana growth.

  7. The N-terminus region of the putative C2H2 transcription factor Ada1 harbors a species-specific activation motif that regulates asexual reproduction in Fusarium verticillioides.

    PubMed

    Malapi-Wight, Martha; Kim, Jung-Eun; Shim, Won-Bo

    2014-01-01

    Fusarium verticillioides is an important plant pathogenic fungus causing maize ear and stalk rots. In addition, the fungus is directly associated with fumonisin contamination of food and feeds. Here, we report the functional characterization of Ada1, a putative Cys2-His2 zinc finger transcription factor with a high level of similarity to Aspergillus nidulans FlbC, which is required for the activation of the key regulator of conidiation brlA. ADA1 is predicted to encode a protein with two DNA binding motifs at the C terminus and a putative activator domain at the N terminus region. Deletion of the flbC gene in A. nidulans results in "fluffy" cotton-like colonies, with a defect in transition from vegetative growth to asexual development. In this study we show that Ada1 plays a key role in asexual development in F. verticillioides. Conidia production was significantly reduced in the knockout mutant (Δada1), in which aberrant conidia and conidiophores were also observed. We identified genes that are predicted to be downstream of ADA1, based on A. nidulans conidiation signaling pathway. Among them, the deletion of stuA homologue, FvSTUA, resulted in near absence of conidia production. To further investigate the functional conservation of this transcription factor, we complemented the Δada1 strain with A. nidulans flbC, F. verticillioides ADA1, and chimeric constructs. A. nidulans flbC failed to restore conidia production similar to the wild-type level. However, the Ada1N-terminal domain, which contains a putative activator, fused to A. nidulans FlbC C-terminal motif successfully complemented the Δada1 mutant. Taken together, Ada1 is an important transcriptional regulator of asexual development in F. verticillioides and that the N-terminus domain is critical for proper function of this transcription factor.

  8. Development of a population-based threshold model of conidial germination for analysing the effects of physiological manipulation on the stress tolerance and infectivity of insect pathogenic fungi.

    PubMed

    Andersen, M; Magan, N; Mead, A; Chandler, D

    2006-09-01

    Entomopathogenic fungi are being used as biocontrol agents of insect pests, but their efficacy can be poor in environments where water availability is reduced. In this study, the potential to improve biocontrol by physiologically manipulating fungal inoculum was investigated. Cultures of Beauveria bassiana, Lecanicillium muscarium, Lecanicillium longisporum, Metarhizium anisopliae and Paecilomyces fumosoroseus were manipulated by growing them under conditions of water stress, which produced conidia with increased concentrations of erythritol. The time-course of germination of conidia at different water activities (water activity, aw) was described using a generalized linear model, and in most cases reducing the water activity of the germination medium delayed the onset of germination without affecting the distribution of germination times. The germination of M. anisopliae, L. muscarium, L. longisporum and P. fumosoroseus was accelerated over a range of aw levels as a result of physiological manipulation. However, the relationship between the effect of physiological manipulation on germination and the osmolyte content of conidia varied according to fungal species. There was a linear relationship between germination rate, expressed as the reciprocal of germination time, and aw of the germination medium, but there was no significant effect of fungal species or physiological manipulation on the aw threshold for germination. In bioassays with M. anisopliae, physiologically manipulated conidia germinated more rapidly on the surface of an insect host, the melon cotton aphid Aphis gossypii, and fungal virulence was increased even when relative humidity was reduced after an initial high period. It is concluded that physiological manipulation may lead to improvements in biocontrol in the field, but choice of fungal species/isolate will be critical. In addition, the population-based threshold model used in this study, which considered germination in terms of physiological

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

    PubMed Central

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

    2015-01-01

    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

  10. Transcriptome analysis of the entomopathogenic fungus Beauveria bassiana grown on cuticular extracts of the coffee berry borer (Hypothenemus hampei).

    PubMed

    Mantilla, Javier Guillermo; Galeano, Narmer F; Gaitan, Alvaro L; Cristancho, Marco A; Keyhani, Nemat O; Góngora, Carmenza E

    2012-07-01

    The coffee berry borer (CBB; Hypothenemus hampei) is a major pest of coffee responsible for significant crop losses worldwide. The entomopathogenic fungus Beauveria bassiana represents a natural means of controlling this insect pest; however, little is known concerning the molecular determinants that contribute to the virulence of the fungus towards the CBB. In order to examine genes involved in insect virulence, two expressed sequence tag (EST) libraries, representing germinating conidia and growing hyphae/mycelia of B. bassiana cells grown on cuticular extracts of the CBB were constructed and analysed. In total, 4186 cDNA transcripts were obtained, which included 2141 from the cuticle-germinated conidia and 2045 from the cuticle-grown mycelium libraries, respectively. The average sequence length obtained was 470 bp and transcript assembly resulted in a set of 1271 and 1305 unique gene sequences for the conidial and mycelia libraries, respectively. Around 50 % of the sequences in each library could be annotated by gene ontology terms. An analysis of the two generated libraries as well as a previously reported EST library of B. bassiana grown on chitin was performed. Between the cuticle-germinated conidia and the cuticle-grown mycelia libraries, 322 unique gene sequences were shared, of which 90 % could be annotated, leaving 949 unique cuticle-germinated conidial genes and 983 unique growing hyphae/mycelia genes of which around 65 % were annotated. ESTs shared between the libraries indicated a basic response pattern for B. bassiana against H. hampei, which included genes implicated in pathogenicity. The expression profiles of four genes were evaluated with a cyclophilin, an alkaline-like serine protease and a mitogen-activated protein kinase (MAPK), showing elevated expression during initial phases of infection, i.e. conidia germinating on insect extracts. These data provide clues and gene candidates for further exploration concerning the biology and

  11. Morphogenetic Alterations of Alternaria alternata Exposed to Dicarboximide Fungicide, Iprodione.

    PubMed

    Kim, Eunji; Lee, Hye Min; Kim, Young Ho

    2017-02-01

    Fungicide-resistant Alternaria alternata impede the practical control of the Alternaria diseases in crop fields. This study aimed to investigate cytological fungicide resistance mechanisms of A. alternata against dicarboximide fungicide iprodione. A. alternata isolated from cactus brown spot was cultured on potato-dextrose agar (PDA) with or without iprodione, and the fungal cultures with different growth characteristics from no, initial and full growth were observed by light and electron microscopy. Mycelia began to grow from one day after incubation (DAI) and continued to be in full growth (control-growth, Con-G) on PDA without fungicide, while on PDA with iprodione, no fungal growth (iprodione-no growth, Ipr-N) occurred for the first 3 DAI, but once the initial growth (iprodione-initial growth, Ipr-I) began at 4-5 DAI, the colonies grew and expanded continuously to be in full growth (iprodione-growth, Ipr-G), suggesting Ipr-I may be a turning moment of the morphogenetic changes resisting fungicidal toxicity. Con-G formed multicellular conidia with cell walls and septa and intact dense cytoplasm. In Ipr-N, fungal sporulation was inhibited by forming mostly undeveloped unicellular conidia with degraded and necrotic cytoplasm. However, in Ipr-I, conspicuous cellular changes occurred during sporulation by forming multicellular conidia with double layered (thickened) cell walls and accumulation of proliferated lipid bodies in the conidial cytoplasm, which may inhibit the penetration of the fungicide into conidial cells, reducing fungicide-associated toxicity, and may be utilized as energy and nutritional sources, respectively, for the further fungal growth to form mature colonies as in Ipr-G that formed multicellular conidia with cell walls and intact cytoplasm with lipid bodies as in Con-G.

  12. An improved Agrobacterium-mediated transformation system for the functional genetic analysis of Penicillium marneffei.

    PubMed

    Kummasook, Aksarakorn; Cooper, Chester R; Vanittanakom, Nongnuch

    2010-12-01

    We have developed an improved Agrobacterium-mediated transformation (AMT) system for the functional genetic analysis of Penicillium marneffei, a thermally dimorphic, human pathogenic fungus. Our AMT protocol included the use of conidia or pre-germinated conidia of P. marneffei as the host recipient for T-DNA from Agrobacterium tumefaciens and co-cultivation at 28°C for 36 hours. Bleomycin-resistant transformants were selected as yeast-like colonies following incubation at 37°C. The efficiency of transformation was approximately 123 ± 3.27 and 239 ± 13.12 transformants per plate when using 5 × 10(4) conidia and pre-germinated conidia as starting materials, respectively. Southern blot analysis demonstrated that 95% of transformants contained single copies of T-DNA. Inverse PCR was employed for identifying flanking sequences at the T-DNA insertion sites. Analysis of these sequences indicated that integration occurred as random recombination events. Among the mutants isolated were previously described stuA and gasC defective strains. These AMT-derived mutants possessed single T-DNA integrations within their particular coding sequences. In addition, other morphological and pigmentation mutants possessing a variety of gene-specific defects were isolated, including two mutants having T-DNA integrations within putative promoter regions. One of the latter integration events was accompanied by the deletion of the entire corresponding gene. Collectively, these results indicated that AMT could be used for large-scale, functional genetic analyses in P. marneffei. Such analyses can potentially facilitate the identification of those genetic elements related to morphogenesis, as well as pathogenesis in this medically important fungus.

  13. Systematic reappraisal of Coniella and Pilidiella, with specific reference to species occurring on Eucalyptus and Vitis in South Africa.

    PubMed

    Van Niekerk, Jan M; Groenewald, J Z Ewald; Verkley, Gerard J M; Fourie, Paul H; Wingfield, Michael J; Crous, Pedro W

    2004-03-01

    The genus Pilidiella, including its teleomorphs in Schizoparme, has a cosmopolitan distribution and is associated with disease symptoms on many plants. In the past, conidial pigmentation has been used as a character to separate Pilidiella (hyaline to pale brown conidia) from Coniella (dark brown conidia). In recent years, however, the two genera have been regarded as synonymous, the older name Coniella having priority. To address the generic question, sequences of the internal transcribed spacer region (ITS1, ITS2), 5.8S gene, large subunit (LSU) and elongation factor 1-alpha gene (EF 1-alpha) were analysed to compare the type species of Pilidiella and Coniella. All three gene regions supported the separation of Coniella from Pilidiella, with the majority of taxa residing in Pilidiella. Pilidiella is characterised by having species with hyaline to pale brown conidia (avg. length:width > 1.5), in contrast to the dark brown conidia of Coniella (avg. length:width < or = 1.5). Pilidiella diplodiella, which is a pathogen associated with white rot of grapevines, was shown to be an older name for C. petrakii. To delineate species in the P. diplodiella species complex, isolates were also compared based on histone (H3) gene sequences. Analyses derived from these sequence data separated P. diplodiella from a newly described species, P. diplodiopsis. The new species P. eucalyptorum sp. nov. is proposed for isolates formerly treated as C. fragariae and associated with leaf spots of Eucalyptus spp. This species clustered basal to Pilidiella, and may represent yet a third genus within this complex. Pilidiella destruens sp. nov. is newly described as anamorph of Schizoparme destruens, which is associated with twig dieback of Eucalyptus spp. in Hawaii. A key based on morphological characteristics is provided to separate the taxa treated in this study.

  14. Correlation of cell surface proteins of distinct Beauveria bassiana cell types and adaption to varied environment and interaction with the host insect.

    PubMed

    Yang, Zhi; Jiang, Hongyan; Zhao, Xin; Lu, Zhuoyue; Luo, Zhibing; Li, Xuebing; Zhao, Jing; Zhang, Yongjun

    2017-02-01

    The insect fungal pathogen Beauveria bassiana produces a number of distinct cell types that include aerial conidia, blastospores and haemolymph-derived cells, termed hyphal bodies, to adapt varied environment niches and within the host insect. These cells display distinct biochemical properties and surface structures, and a highly ordered outermost brush-like structure uniquely present on hyphal bodies, but not on any in vitro cells. Here, we found that the outermost structure on the hyphal bodies mainly consisted of proteins associated to structural wall components in that most of it could be removed by dithiothreitol (DTT) or proteinase K. DTT-treatment also caused delayed germination, decreased tolerance to ultraviolet irradiation and virulence of conidia or blastospores, with decreased adherence and alternated carbohydrate epitopes, suggesting involvement in fungal development, stress responses and virulence. To characterize these cell surface molecules, proteins were released from the living cells using DTT, and identified and quantitated using label-free quantitative mass spectrometry. Thereafter, a series of bioinformatics programs were used to predict cell surface-associated proteins (CSAPs), and 96, 166 and 54 CSAPs were predicted from the identified protein pools of conidia, blastospores and hyphal bodies, respectively, which were involved in utilization of carbohydrate, nitrogen, and lipid, detoxification, pathogen-host interaction, and likely other cellular processes. Thirteen, sixty-nine and six CSAPs were exclusive in conidia, blastospores and hyphal bodies, respectively, which were verified by eGFP-tagged proteins at their N-terminus. Our data provide a crucial cue to understand mechanism of B. bassiana to adapt to varied environment and interaction with insect host.

  15. Phyllosticta ophiopogonis sp. nov. from Ophiopogon japonicus (Liliaceae)

    PubMed Central

    Wikee, S.; Wulandari, N.F.; McKenzie, E.H.C.; Hyde, K.D.

    2011-01-01

    A leaf spotting disease of an ornamental variety of Ophiopogon japonicus was discovered at several locations in northern Thailand. In all cases a species of Phyllosticta was associated with the lesions. Phyllosticta ophiopogonis sp. nov. is distinguished from Phyllosticta species from Liliaceae in conidia size, mucilaginous sheath and appendage thus the species is introduced as new in this paper. The new species which causes unsightly lesions on this ornamental plant is described, illustrated and compared with other similar Phyllosticta species. PMID:23961156

  16. Pathogenicity of entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana (Hypocreales: Clavicipitaceae) isolates to the adult pea leafminer (Diptera: Agromyzidae) and prospects of an autoinoculation device for infection in the field.

    PubMed

    Migiro, L N; Maniania, N K; Chabi-Olaye, A; Vandenberg, J

    2010-04-01

    Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) were evaluated for their pathogenicity to the adult pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), in the laboratory. Flies were contaminated with dry conidia through a velvet material wrapped around the inner side of a cylindrical plastic tube. All the isolates were pathogenic to the pea leafminer, causing mortality between 40 and 100% at 5 d after exposure. The lethal time for 50% mortality (LT(50)) ranged from 2.6 to 5.4 d, whereas the LT(90) values varied between 3.2 and 9.1 d depending on the isolate. An autoinoculation device was evaluated in cage field experiments using only one of the virulent isolates, M. anisopliae ICIPE 20. The device was loaded with 2-3 g of dry conidia. Mortality of up to 100% was observed in flies captured from fungus-treated cages held under laboratory conditions. The average number of spores picked up by a single fly visiting the device increased with days after inoculation. One day after the inoculation, adults picked up an average of 4.1 +/- 0.7 x 10(5) conidia and 39.6 +/- 4.0 x 10(5) conidia 5 d after inoculation. Depending on the sampling date, the LT(50) varied between 1.8 and 3.4 d. Results indicate that some isolates of B. bassiana and M. anisopliae are highly pathogenic to L. huidobrensis, suggesting a potential for their use in the control of this pest. They also suggest the possibility of L. huidobrensis suppression with fungi using an autoinoculation device.

  17. THE EFFECT OF TEMPERATURE AND HUMIDITY ON THE TOBACCO POWDERY MILDEW FUNGUS

    DTIC Science & Technology

    The influence of temperature on the germination of conidia and on the infection of tobacco by powdery mildew was determined. For the former the...The existence of a very close correlation between the occurrence of powdery mildew in certain tobacco areas and the average daily maximum-minimum...temperatures prevailing in those areas could be shown. It was found, for example, that powdery mildew did not occur in areas in which the prevailing

  18. Virulence determinants of the human pathogenic fungus Aspergillus fumigatus protect against soil amoeba predation.

    PubMed

    Hillmann, Falk; Novohradská, Silvia; Mattern, Derek J; Forberger, Tilmann; Heinekamp, Thorsten; Westermann, Martin; Winckler, Thomas; Brakhage, Axel A

    2015-08-01

    Filamentous fungi represent classical examples for environmentally acquired human pathogens whose major virulence mechanisms are likely to have emerged long before the appearance of innate immune systems. In natural habitats, amoeba predation could impose a major selection pressure towards the acquisition of virulence attributes. To test this hypothesis, we exploited the amoeba Dictyostelium discoideum to study its interaction with Aspergillus fumigatus, two abundant soil inhabitants for which we found co-occurrence in various sites. Fungal conidia were efficiently taken up by D. discoideum, but ingestion was higher when conidia were devoid of the green fungal spore pigment dihydroxynaphtalene melanin, in line with earlier results obtained for immune cells. Conidia were able to survive phagocytic processing, and intracellular germination was initiated only after several hours of co-incubation which eventually led to a lethal disruption of the host cell. Besides phagocytic interactions, both amoeba and fungus secreted cross inhibitory factors which suppressed fungal growth or induced amoeba aggregation with subsequent cell lysis, respectively. On the fungal side, we identified gliotoxin as the major fungal factor killing Dictyostelium, supporting the idea that major virulence attributes, such as escape from phagocytosis and the secretion of mycotoxins are beneficial to escape from environmental predators.

  19. The role of initial spore adhesion in pellet and biofilm formation in Aspergillus niger.

    PubMed

    Priegnitz, Bert-Ewald; Wargenau, Andreas; Brandt, Ulrike; Rohde, Manfred; Dietrich, Sylvia; Kwade, Arno; Krull, Rainer; Fleissner, André

    2012-01-01

    Fungi grow on a great variety of organic and inorganic materials. Colony establishment and growth on solid surfaces require adhesion of spores and hyphae to the substrate, while cell-to-cell interactions among spores and/or hyphae are a prerequisite for the development of three-dimensional mycelial structures such as pellets or biofilms. Surface adherence has been described as a two-step process, comprised of the initial attachment of ungerminated conidia followed by further adhesion of the forming germ tubes and growing hyphae. In the present study, we analyzed the contribution of adhesion of ungerminated spores to pellet and biofilm formation in Aspergillus niger. Mutants deficient in melanin biosynthesis were constructed by the deletion of the alb1 gene, encoding a polyketide synthase essential for pigment biosynthesis. Δalb1 conidia have an altered surface structure and changed physicochemical surface properties. Spore aggregation in liquid culture as well as spore surface attachment differ between the wild type and the mutant in a pH-dependent manner. In liquid culture further pellet formation is unaffected by altered spore-spore interactions, indicating that germ tube and hyphal adherence can compensate for deficiencies in the initial step of spore attachment. In contrast, under conditions promoting adhesion of Δalb1 conidia to polymer surfaces the mutant forms more stable biofilms than the wild type, suggesting that initial spore adhesion supports sessile growth.

  20. The CarO rhodopsin of the fungus Fusarium fujikuroi is a light-driven proton pump that retards spore germination

    PubMed Central

    García-Martínez, Jorge; Brunk, Michael; Avalos, Javier; Terpitz, Ulrich

    2015-01-01

    Rhodopsins are membrane-embedded photoreceptors found in all major taxonomic kingdoms using retinal as their chromophore. They play well-known functions in different biological systems, but their roles in fungi remain unknown. The filamentous fungus Fusarium fujikuroi contains two putative rhodopsins, CarO and OpsA. The gene carO is light-regulated, and the predicted polypeptide contains all conserved residues required for proton pumping. We aimed to elucidate the expression and cellular location of the fungal rhodopsin CarO, its presumed proton-pumping activity and the possible effect of such function on F. fujikuroi growth. In electrophysiology experiments we confirmed that CarO is a green-light driven proton pump. Visualization of fluorescent CarO-YFP expressed in F. fujikuroi under control of its native promoter revealed higher accumulation in spores (conidia) produced by light-exposed mycelia. Germination analyses of conidia from carO− mutant and carO+ control strains showed a faster development of light-exposed carO− germlings. In conclusion, CarO is an active proton pump, abundant in light-formed conidia, whose activity slows down early hyphal development under light. Interestingly, CarO-related rhodopsins are typically found in plant-associated fungi, where green light dominates the phyllosphere. Our data provide the first reliable clue on a possible biological role of a fungal rhodopsin. PMID:25589426

  1. Talaromyces neofusisporus and T. qii, two new species of section Talaromyces isolated from plant leaves in Tibet, China.

    PubMed

    Wang, Qi-Ming; Zhang, Yong-Hong; Wang, Bo; Wang, Long

    2016-01-04

    Two new species isolated from plant leaves belonging to Talaromyces section Talaromyces are reported, namely T. neofusisporus (ex-type AS3.15415 (T) = CBS 139516 (T)) and T. qii (ex-type AS3.15414 (T) = CBS 139515 (T)). Morphologically, T. neofusisporus is featured by forming synnemata on CYA and YES, bearing appressed biverticillate penicilli and smooth-walled fusiform conidia about 3.5-4.5 × 2-2.5 μm; and T. qii is characterized by velutinous colony texture, yellowish green conidia, yellow mycelium and ovoid to subglobose echinulate conidia measuring 3-3.5 μm. Phylogenetically, T. neofusisporus is such a unique species that no close relatives are found according to CaM, BenA and ITS1-5.8S-ITS2 as well as the combined three-gene sequences; and T. qii is related to T. thailandensis according to CaM, BenA and the combined sequence matrices, whereas ITS1-5.8S-ITS2 sequences do not support the close relationship between T. qii and T. thailandensis.

  2. A Mechanistic Model of Botrytis cinerea on Grapevines That Includes Weather, Vine Growth Stage, and the Main Infection Pathways

    PubMed Central

    González-Domínguez, Elisa; Caffi, Tito; Ciliberti, Nicola; Rossi, Vittorio

    2015-01-01

    A mechanistic model for Botrytis cinerea on grapevine was developed. The model, which accounts for conidia production on various inoculum sources and for multiple infection pathways, considers two infection periods. During the first period (“inflorescences clearly visible” to “berries groat-sized”), the model calculates: i) infection severity on inflorescences and young clusters caused by conidia (SEV1). During the second period (“majority of berries touching” to “berries ripe for harvest”), the model calculates: ii) infection severity of ripening berries by conidia (SEV2); and iii) severity of berry-to-berry infection caused by mycelium (SEV3). The model was validated in 21 epidemics (vineyard × year combinations) between 2009 and 2014 in Italy and France. A discriminant function analysis (DFA) was used to: i) evaluate the ability of the model to predict mild, intermediate, and severe epidemics; and ii) assess how SEV1, SEV2, and SEV3 contribute to epidemics. The model correctly classified the severity of 17 of 21 epidemics. Results from DFA were also used to calculate the daily probabilities that an ongoing epidemic would be mild, intermediate, or severe. SEV1 was the most influential variable in discriminating between mild and intermediate epidemics, whereas SEV2 and SEV3 were relevant for discriminating between intermediate and severe epidemics. The model represents an improvement of previous B. cinerea models in viticulture and could be useful for making decisions about Botrytis bunch rot control. PMID:26457808

  3. In-depth Analysis of the Magnaporthe oryzae Conidial Proteome

    PubMed Central

    Gokce, Emine; Franck, William L.; Oh, Yeonyee; Dean, Ralph A.; Muddiman, David C.

    2013-01-01

    The filamentous fungus Magnaporthe oryzae (M. oryzae) is the causative agent of rice blast disease and presents a significant threat to worldwide rice production. To establish the groundwork for future research on the pathogenic development of M. oryzae, a global proteomic study of conidia was performed. The filter aided sample preparation method (FASP) and anion StageTip fractionation combined with long, optimized shallow 210 min nanoLC gradients prior to mass spectrometry analysis on an Orbitrap XL was applied, which resulted in a doubling of protein identifications in comparison to our previous GeLC analysis. Herein, we report the identification of 2912 conidial proteins at a 1% protein false discovery rate (FDR) and we present the most extensive study performed on M. oryzae conidia to date. A similar distribution between identified proteins and the predicted proteome was observed when subcellular localization analysis was performed, suggesting the detected proteins build a representative portion of the predicted proteome. A higher percentage of cytoplasmic proteins (associated with translation, energy and metabolism) were observed in the conidial proteome relative to the whole predicted proteome. Conversely, nuclear and extracellular proteins were less well represented in the conidial proteome. Further analysis by gene ontology revealed biological insights into identified proteins important for central metabolic processes and the physiology of conidia. PMID:23039028

  4. abaA controls phialide differentiation in Aspergillus nidulans.

    PubMed Central

    Sewall, T C; Mims, C W; Timberlake, W E

    1990-01-01

    Aspergillus nidulans is an ascomycetous fungus that reproduces asexually by forming multicellular conidiophores and uninucleate spores called conidia. Loss of function mutations in the abacus A (abaA) regulatory locus result in formation of aberrant conidiophores that fail to produce conidia. Wild-type conidiophores form two tiers of sterigmata. The first tier, metulae, divide to produce the second tier, phialides. Phialides are sporogenous cells that produce conidia through a specialized apical budding process. We have examined conidiophore development in an abaA- strain at the ultrastructural level. The results showed that in the mutant metulae produce supernumerary tiers of cells with metula-like, rather than phialide-like, properties. Temperature shift experiments with an abaA14ts strain demonstrated that abaA+ function induced phialide formation by the aberrant abacus cells and was continuously required for maintenance of phialide function. In the absence of abaA+ activity, metulae simply proliferated and later developmental steps never occurred. We conclude that abaA+ directs the differentiation of phialides and is continuously required for maintenance of their function. PMID:2152124

  5. Photodynamic inactivation of mold fungi spores by newly developed charged corroles.

    PubMed

    Preuß, Annegret; Saltsman, Irena; Mahammed, Atif; Pfitzner, Michael; Goldberg, Israel; Gross, Zeev; Röder, Beate

    2014-04-05

    The photodynamic effect, originally used in photodynamic therapy (PDT) for the treatment of different diseases, e.g. of cancer, has recently been introduced for the inactivation of bacteria. Mold fungi, which provoke health problems like allergies and diseases of the respiratory tract, are even more resistant and their biology is also very different. This study presents the development of four new photosensitizers, which, in combination with low doses of white light, inhibit the germination of mold fungi spores. Two of them even cause lethal damage to the conidia (spores) which are responsible for the spreading of mold fungi. The photoactivity of the newly synthesized corroles was obtained by their application on three different mold fungi: Aspergillus niger, Cladosporium cladosporoides, and Penicillium purpurgenum. To distinguish between inactivation of germination and permanent damage, the fungi were first incubated under illumination for examination of photosensitizer-induced growth inhibition and then left in darkness to test the survival of the conidia. None of the compounds displayed dark toxicity, but all of them attenuated or prevented germination when exposed to light, and the positively charged complexes induced a complete damage of the conidia.

  6. Inhibition by estrogens of conidium-to-yeast conversion in the fungus Paracoccidioides brasiliensis.

    PubMed

    Salazar, M E; Restrepo, A; Stevens, D A

    1988-03-01

    Conidia produced by Paracoccidioides brasiliensis are inhibited by mammalian estrogens in their in vitro conversion into yeast-form cells. This was demonstrated with four different isolates. In these experiments, conversion was reduced to 10.7 and 34.4% of the control values by 17-beta-estradiol at 10(-6) and 10(-8) M, respectively. At the same concentrations, the synthetic estrogen diethylstilbestrol was slightly less inhibitory. In contrast, other sex hormones and analogs, i.e., testosterone, 17-alpha-estradiol, tamoxifen, and hydroxytamoxifen, had no effect on conidium-to-yeast conversion. Previous studies have shown that estrogens similarly inhibit mycelium-to-yeast-form transition in P. brasiliensis. Conidia, and not mycelial fragments, are believed to be the natural infectious propagules. These findings with conidia support the hypothesis that estrogens, affecting the initial host-parasite interactions by suppressing conversion to the parasitic form of the organism, are, at least in part, responsible for the greater resistance of females to paracoccidioidomycosis.

  7. Inhibition by estrogens of conidium-to-yeast conversion in the fungus Paracoccidioides brasiliensis.

    PubMed Central

    Salazar, M E; Restrepo, A; Stevens, D A

    1988-01-01

    Conidia produced by Paracoccidioides brasiliensis are inhibited by mammalian estrogens in their in vitro conversion into yeast-form cells. This was demonstrated with four different isolates. In these experiments, conversion was reduced to 10.7 and 34.4% of the control values by 17-beta-estradiol at 10(-6) and 10(-8) M, respectively. At the same concentrations, the synthetic estrogen diethylstilbestrol was slightly less inhibitory. In contrast, other sex hormones and analogs, i.e., testosterone, 17-alpha-estradiol, tamoxifen, and hydroxytamoxifen, had no effect on conidium-to-yeast conversion. Previous studies have shown that estrogens similarly inhibit mycelium-to-yeast-form transition in P. brasiliensis. Conidia, and not mycelial fragments, are believed to be the natural infectious propagules. These findings with conidia support the hypothesis that estrogens, affecting the initial host-parasite interactions by suppressing conversion to the parasitic form of the organism, are, at least in part, responsible for the greater resistance of females to paracoccidioidomycosis. Images PMID:3343055

  8. Evaluation of a New Entomopathogenic Strain of Beauveria bassiana and a New Field Delivery Method against Solenopsis invicta

    PubMed Central

    Li, Jun; Guo, Qiang; Lin, Miaofeng; Jiang, Lu; Ye, Jingwen; Chen, Dasong; Li, Zhigang; Dai, Jianqing; Han, Shichou

    2016-01-01

    Solenopsis invicta Buren is one of the most important pests in China, and control measures are mainly based on the use of synthetic pesticides, which may be inadequate and unsustainable. Hence, there is a growing interest in developing biological control alternatives for managing S. invicta, such as the use of entomopathogenic fungi. To facilitate the commercialization of entomopathogenic fungi against S. invicta, 10 Beauveria bassiana isolates originating from different hosts were tested for virulence in laboratory bioassays, and the most pathogenic strain, ZGNKY-5, was tested in field studies using an improved pathogen delivery system. The cumulative mortality rate reached 93.40% at 1×108 mL-1 conidia after 504 h. The germination and invasion of the spores were observed under a scanning electron microscope, and several conidia adhered to the cuticle of S. invicta after 2 h. Furthermore, the germ tubes of the conidia oriented toward the cuticle after 48 h, and the mycelium colonized the entire body after 96 h. Based on the efficacy observed in the laboratory trials, further experiments were performed with ZGNKY-5 strain to evaluate its utility in an injection control technology against S. invicta in the field. We found that three dosage treatments of ZGNKY-5 strain (500 mL, 750 mL, and 1,000 mL per nest) had significant control effects. Our results show that this strain of Beauveria bassiana and our control method were effective against S. invicta in both laboratory and field settings. PMID:27341441

  9. Evaluation of a New Entomopathogenic Strain of Beauveria bassiana and a New Field Delivery Method against Solenopsis invicta.

    PubMed

    Li, Jun; Guo, Qiang; Lin, Miaofeng; Jiang, Lu; Ye, Jingwen; Chen, Dasong; Li, Zhigang; Dai, Jianqing; Han, Shichou

    2016-01-01

    Solenopsis invicta Buren is one of the most important pests in China, and control measures are mainly based on the use of synthetic pesticides, which may be inadequate and unsustainable. Hence, there is a growing interest in developing biological control alternatives for managing S. invicta, such as the use of entomopathogenic fungi. To facilitate the commercialization of entomopathogenic fungi against S. invicta, 10 Beauveria bassiana isolates originating from different hosts were tested for virulence in laboratory bioassays, and the most pathogenic strain, ZGNKY-5, was tested in field studies using an improved pathogen delivery system. The cumulative mortality rate reached 93.40% at 1×108 mL-1 conidia after 504 h. The germination and invasion of the spores were observed under a scanning electron microscope, and several conidia adhered to the cuticle of S. invicta after 2 h. Furthermore, the germ tubes of the conidia oriented toward the cuticle after 48 h, and the mycelium colonized the entire body after 96 h. Based on the efficacy observed in the laboratory trials, further experiments were performed with ZGNKY-5 strain to evaluate its utility in an injection control technology against S. invicta in the field. We found that three dosage treatments of ZGNKY-5 strain (500 mL, 750 mL, and 1,000 mL per nest) had significant control effects. Our results show that this strain of Beauveria bassiana and our control method were effective against S. invicta in both laboratory and field settings.

  10. Effect of vacuolar ATPase subunit H (VmaH) on cellular pH, asexual cycle, stress tolerance and virulence in Beauveria bassiana.

    PubMed

    Zhu, Jing; Zhu, Xiao-Guan; Ying, Sheng-Hua; Feng, Ming-Guang

    2017-01-01

    Vacuolar ATPase (V-ATPase) is a conserved multi-subunit protein complex that mediates intracellular acidification in fungi. Here we show functional diversity of V-ATPase subunit H (BbVmaH) in Beauveria bassiana, a filamentous fungal insect pathogen. Deletion of BbvmaH resulted in elevated vacuolar pH, increased Ca(2+) level in cytosol but not in vacuoles, accelerated culture acidification and reduced accumulation of extracellular ammonia. Aerial conidiation and submerged blastospore production were largely delayed and reduced in the deletion mutant, respectively, accompanied with a significant delay in conidial germination, alterations of conidia and blastospores in morphology, size and/or density, and severe growth defects in minimal media with different carbon and nitrogen sources. Despite null responses to osmotic, oxidative and cell wall perturbing stresses, the deletion mutant showed increased sensitivity to Ca(2+), Zn(2+) and Cu(2+) during growth while its conidia were less tolerant to a wet-heat stress at 45°C and UV-B irradiation. Intracellular glycerol and mannitol contents also decreased significantly. Its virulence to Galleria mellonella larvae was significantly attenuated when conidia were topically applied for normal cuticle infection or injected into haemocoel for cuticle-bypassing infection. All phenotypic changes were restored by targeted gene complementation. Our results indicate that BbVmaH plays an important role in sustaining not only vacuolar acidification but also cytosolic calcium accumulation, ambient pH homeostasis, in vitro asexual cycle and virulence in B. bassiana.

  11. Ultrastructural Exploration on the Histopathological Change in Phenacoccus fraxinus Infected with Lecanicillium lecanii

    PubMed Central

    Gao, Ying; Xie, Ying Ping; Xiong, Qi; Liu, Wei Min; Xue, Jiao Liang

    2015-01-01

    The histopathological changes of the second instar nymph of the mealybug Phenacoccus fraxinus infected with Lecanicillium lecanii strain 3.4505 were investigated using light, scanning and transmission electron microscopy. The results demonstrated that L. lecanii 3.4505 could infect P. fraxinus in a short period. At 24 h post-inoculation, the conidia of L. lecanii 3.4505 adhered to the indented gloves or intersegmental folds of the insect body surface. Subsequently, the germinated conidia produced germ-tubes, appressoria and extended hyphae, which tightly adhered to the cuticle. Penetration of cuticle could be achieved either by peg form appressoria or directly by hyphae. Also, the conidia and hyphae could secrete massive mucilages causing visible damage to the host cuticle. After 48 h, the body wall, tissues and organs, including cuticle, trachea, fat body, muscle, Malpighian tubules and nerve ganglion, were destroyed by ramification of hyphae as a result of infection. The endoplasmic reticulum hypertrophied and formed obvious fingerprint agglomerates, and the mitochondria swelled and deformed in the haemocytes. Finally, the mycelium fully occupied the entire haemocoel. The entire bodies were wrapped in a white mycelium, with the mycelium extending radically outward. PMID:25629309

  12. Characterization and virulence of Beauveria bassiana associated with auger beetle (Sinoxylon anale) infesting allspice (Pimenta dioica).

    PubMed

    Senthil Kumar, C M; Jacob, T K; Devasahayam, S; D'Silva, Sharon; Nandeesh, P G

    2016-09-01

    The incidence of auger beetle, Sinoxylon anale Lesne (Bostrichidae: Coleoptera), a destructive pest of cosmopolitan occurrence is reported for the first time on allspice trees, Pimenta dioica (L.) Merr. in Kerala, India. The insects bored through the basal region of fresh twigs resulting in dieback symptoms. Morphological characterization and sequencing of a partially amplified fragment of the mitochondrial CO1 gene (696bp) revealed the insect to be Sinoxylon anale. An entomopathogenic fungus was isolated from infected cadavers of S. anale that was identified as Beauveria bassiana (Bals.-Criv.) Vuill., sensu stricto (s.s.) (Ascomycota: Hypocreales) based on morphological and molecular studies. The partial sequences of the ITS, TUB, TEF and Bloc gene regions were sequenced. The fungus grew well in ambient room temperature conditions (28-32±2°C; 60-70% relative humidity) and the infection process on the insect was documented by scanning electron microscopy. Bioassay studies with the isolate indicated that the fungus was virulent against adult beetles as evidenced by the LC50 (3.6×10(6)conidia/ml) and ST50 values (6.8days at a dose of 1×10(7)conidia/ml and 5.8days at a dose of 1×10(8)conidia/ml, respectively). This is the first record of B. bassiana naturally infecting S. anale and the fungus holds promise to be developed as a mycoinsecticide.

  13. Nest sanitation through defecation: antifungal properties of wood cockroach feces

    NASA Astrophysics Data System (ADS)

    Rosengaus, Rebeca B.; Mead, Kerry; Du Comb, William S.; Benson, Ryan W.; Godoy, Veronica G.

    2013-11-01

    The wood cockroach Cryptocercus punctulatus nests as family units inside decayed wood, a substrate known for its high microbial load. We tested the hypothesis that defecation within their nests, a common occurrence in this species, reduces the probability of fungal development. Conidia of the entomopathogenic fungus, Metarhizium anisopliae, were incubated with crushed feces and subsequently plated on potato dextrose agar. Relative to controls, the viability of fungal conidia was significantly reduced following incubation with feces and was negatively correlated with incubation time. Although the cockroach's hindgut contained abundant β-1,3-glucanase activity, its feces had no detectable enzymatic function. Hence, these enzymes are unlikely the source of the fungistasis. Instead, the antifungal compound(s) of the feces involved heat-sensitive factor(s) of potential microbial origin. When feces were boiled or when they were subjected to ultraviolet radiation and subsequently incubated with conidia, viability was "rescued" and germination rates were similar to those of controls. Filtration experiments indicate that the fungistatic activity of feces results from chemical interference. Because Cryptocercidae cockroaches have been considered appropriate models to make inferences about the factors fostering the evolution of termite sociality, we suggest that nesting in microbe-rich environments likely selected for the coupling of intranest defecation and feces fungistasis in the common ancestor of wood cockroaches and termites. This might in turn have served as a preadaptation that prevented mycosis as these phylogenetically related taxa diverged and evolved respectively into subsocial and eusocial organizations.

  14. Critical Values of Porosity in Rice Cultures of Isaria fumosorosea by Adding Water Hyacinth: Effect on Conidial Yields and Quality.

    PubMed

    Angel-Cuapio, Alejandro; Figueroa-Montero, Arturo; Favela-Torres, Ernesto; Viniegra-González, Gustavo; Perraud-Gaime, Isabelle; Loera, Octavio

    2015-09-01

    Conidia of the entomopathogenic fungus Isaria fumosorosea are used to control insect pests in crops. Commercially available mycoinsecticides manufactured with this fungus are produced on a large scale via solid-state cultures (SSC). In order to favour gaseous exchange in SCC, texturizers can be added to increase porosity fraction (ε). This work presents results of water hyacinth (Eichhornia crassipes) as a novel texturizer. A mixture of parboiled rice (PR), with a ε = 0.23, was used as a substrate, which was then mixed with water hyacinth (WH amendment) as a texturizer at different proportions affecting ε. Strains CNRCB1 and ARSEF3302 of I. fumosorosea yielded 1.6 (1.49-1.71) × 10(9) and 7.3 (7.02-7.58) × 10(9) conidia per gram of initial dry rice after 8 days, at ε values of 0.34 and 0.36, respectively. Improvement of conidial yields corresponded to 1.33 and 1.55 times, respectively, compared to rice alone using WH amendment in the mixtures PR:WH (%) at 90-10 and 80-20. In addition, infectivity against Galleria mellonella larvae was maintained. This is the first report of the use of water hyacinth as a texturizer in SSC, affecting ε, which is proposed a key parameter in conidia production by I. fumosorosea, without affecting conidial infectivity.

  15. Talaromyces neofusisporus and T. qii, two new species of section Talaromyces isolated from plant leaves in Tibet, China

    PubMed Central

    Wang, Qi-Ming; Zhang, Yong-Hong; Wang, Bo; Wang, Long

    2016-01-01

    Two new species isolated from plant leaves belonging to Talaromyces section Talaromyces are reported, namely T. neofusisporus (ex-type AS3.15415 T = CBS 139516 T) and T. qii (ex-type AS3.15414 T = CBS 139515 T). Morphologically, T. neofusisporus is featured by forming synnemata on CYA and YES, bearing appressed biverticillate penicilli and smooth-walled fusiform conidia about 3.5–4.5 × 2–2.5 μm; and T. qii is characterized by velutinous colony texture, yellowish green conidia, yellow mycelium and ovoid to subglobose echinulate conidia measuring 3–3.5 μm. Phylogenetically, T. neofusisporus is such a unique species that no close relatives are found according to CaM, BenA and ITS1-5.8S-ITS2 as well as the combined three-gene sequences; and T. qii is related to T. thailandensis according to CaM, BenA and the combined sequence matrices, whereas ITS1-5.8S-ITS2 sequences do not support the close relationship between T. qii and T. thailandensis. PMID:26725318

  16. Rapid Isolation of the Trichoderma Strain with Higher Degrading Ability of a Filter Paper and Superior Proliferation Characteristics Using Avicel Plates and the Double-Layer Selection Medium

    NASA Astrophysics Data System (ADS)

    Toyama, Hideo; Nakano, Megumi; Satake, Yuuki; Toyama, Nobuo

    The cost of cellulase is still a problem for bioethanol production. As the cellulase of Trichoderma reesei is applicable for producing ethanol from cellulosic materials, the cellulase productivity of this fungus should be increased. Therefore, we attempted to develop a system to isolate the strain with higher degrading ability of a filter paper and superior proliferation characteristics among the conidia treated with the mitotic arrester, colchicine. When green mature conidia of T. reesei RUT C-30 were swollen, autopolyploidized, and incubated in the double-layer selection medium containing Avicel, colonies appeared on the surface earlier than the original strain. When such colonies and the original colony were incubated on the Avicel plates, strain B5, one of the colonies derived from the colchicinetreated conidia, showed superior proliferation characteristics. Moreover, when strain B5 and the original strain were compared in the filter paper degrading ability and the cellulose hydrolyzing activity, strain B5 was also superior to the original strain. It was suspected that superior proliferation characteristics of strain B5 reflects higher filter paper degrading ability. Thus, we concluded that the Trichoderma strain with higher degrading ability of a filter paper and superior proliferation characteristics can be isolated using Avicel plates and the double-layer selection medium.

  17. Fungus dose-dependent primary pulmonary aspergillosis in immunosuppressed mice.

    PubMed Central

    Dixon, D M; Polak, A; Walsh, T J

    1989-01-01

    We report on a model of primary pulmonary aspergillosis occurring after intranasal instillation of concentrated suspensions of conidia of Aspergillus fumigatus in immunocompromised mice. Unconcentrated suspensions of inoculum contained ca. 2 x 10(7) conidia per ml (1x). These suspensions were concentrated by centrifugation, adjusted to give ca. 2 x 10(8) (10x) or 2 x 10(9) (100x) conidia per ml, and delivered in 30-microliters droplets to the nares of anesthetized mice. Mice were untreated or injected with cortisone acetate (CA) or cyclophosphamide (CY) in various dosage regimens. It was not possible to obtain mortality of more than 50% with sublethal immunosuppressive treatment and 1x fungus. In contrast, mortality followed a fungus dose response in mice receiving sublethal immunosuppression with either CA or CY. Mortality rates of up to 100% were obtained with 100x fungus and a single dose of CY (200 mg/kg) or CA (250 mg/kg) or three alternate doses (125 mg/kg per day) of CA prior to infection. This model is applicable to the study of acute, fatal primary pulmonary aspergillosis and chemotherapy trials. PMID:2651308

  18. The Aspergillus fumigatus Transcription Factor Ace2 Governs Pigment Production, Conidiation and Virulence

    PubMed Central

    Ejzykowicz, Daniele E.; Cunha, Marcel M.; Rozental, Sonia; Solis, Norma V.; Gravelat, Fabrice N.; Sheppard, Donald C.; Filler, Scott G.

    2009-01-01

    Summary Aspergillus fumigatus causes serious and frequently fatal infections in immunocompromised patients. To investigate the regulation of virulence of this fungus, we constructed and analyzed an A. fumigatus mutant that lacked the transcription factor Ace2, which influences virulence in other fungi. The Δace2 mutant had dysmorphic conidiophores, reduced conidia production, and abnormal conidial cell wall architecture. This mutant produced an orange pigment when grown on solid media, although its conidia had normal pigmentation. Conidia of the Δace2 mutant were larger and had accelerated germination. The resulting germlings were resistant to hydrogen peroxide, but not other stressors. Non-neutropenic mice that were immunosuppressed with cortisone acetate and infected with the Δace2 mutant had accelerated mortality, greater pulmonary fungal burden, and increased pulmonary inflammatory responses compared to mice infected with the wild-type or Δace2∷ace2 complemented strains. The Δace2 mutant had reduced ppoC, ecm33, and ags3 mRNA expression. It is known that A. fumigatus mutants with absent or reduced expression of these genes have increased virulence in mice, as well as other phenotypic similarities to the Δace2 mutant. Therefore, reduced expression of these genes likely contributes to the increased virulence of the Δace2 mutant. PMID:19220748

  19. Optimization of the medium composition of a biphasic production system for mycelial growth and spore production of Aschersonia placenta using response surface methodology.

    PubMed

    Qiu, Junzhi; Song, Feifei; Qiu, Yunfeng; Li, Xiaoxia; Guan, Xiong

    2013-02-01

    The culture media for mycelial growth and sporulation of the entomopathogenic fungus Aschersonia placenta were optimized using the response surface method (RSM). Interactions of medium components and the optimization of a biphasic production system were studied using Box-Behnken design (BBD) with three levels of three variables. Experimentation confirmed that the model developed based on RSM and BBD successfully predicted mycelia production (R(2) = 0.9336) and conidia production (R(2) = 0.9532). In the first phase, mycelial dry weight was highest (2.14 ± 0.17 g per 100ml of culture, mean±SE) when the concentrations (g/l) of glucose, vitamin B(6), and MgSO(4)·7H(2)O were 31.4, 11.5, and 0.64, respectively. In the second phase, conidia production was highest (9.31 ± 0.48 × 10(7)sporespercm(2)) after 18d of cultivation in the medium containing 33.8 g/l of millet, 1.11 g/l of KH(2)PO(4), and 0.37 g/l of MgSO(4). Mycelial and conidial yields were 3.6- and 10-fold greater, respectively, with the optimized media than with the non-optimized basal media. The results indicate that RSM and BBD methods are effective for increasing the production of A. placenta mycelia and conidia.

  20. The role of diamondback moth cuticle surface compounds in pre-penetration growth of the entomopathogen Isaria fumosoroseus.

    PubMed

    Ali, Shaukat; Huang, Zhen; Ren, Shunxiang

    2010-10-01

    Transcript patterns elicited in response to hosts can reveal how fungi recognize suitable hosts and the mechanisms involved in pathogenicity. These patterns could be fashioned by recognition of host-specific topographical features or by chemical components displayed or released by the host. We investigated this in three isolates of Isaria fumosoroseus which has shown considerable pathogenic ability against Plutella xylostella. Conidia inoculated to hind wings had the highest germination ability while the conidia inoculated to head regions showed the lowest germination. Conidia applied to diamondback moth wings showed slightly lower rates of germination than those incubated on SDA. Although I. funosoroseus isolates germinated well on crude methanol extracts, only low levels of germination occurred on hexane and dichloromethane extracts. Similarly, poor germination was also observed on diamondback moth hind wing from which cuticular lipids were extracted by using methanol when compared to the untreated hind wings showing that simple polar compounds are required to stimulate germination before the fungus can make effective use of a complex mixture of non-polar lipids. Such studies could address the origin of intraspecies differences and correlate these differences with the underlying metabolic and biosynthetic differences that define different host ranges.

  1. Fungal infection of mantis shrimp (Oratosquilla oratoria) caused by two anamorphic fungi found in Japan.

    PubMed

    Duc, Pham Minh; Hatai, Kishio; Kurata, Osamu; Tensha, Kozue; Yoshitaka, Uchida; Yaguchi, Takashi; Udagawa, Shun-ichi

    2009-05-01

    Two fungal pathogens of the mantis shrimp (Oratosquilla oratoria) in Yamaguchi and Aichi Prefectures, Japan are described as the new species Plectosporium oratosquillae and Acremonium sp. (a member of the Emericellopsis marine clade). Both fungi infect the gills of the mantis shrimp, which become brown or black due to melanization. The former species is characterized by its slow growth on artificial seawater yeast extract peptone glucose (PYGS) agar, pale yellow to pale orange or grayish yellow colonies, short cylindrical solitary phialides with a wavy tip, and one-celled ellipsoidal conidia. Although lacking the two-celled conidia demonstrated by the type species Plectosporium tabacinum, the taxonomic placement of the new species was confirmed by DNA sequence analysis of the internal transcribed spacer (ITS) region of ribosomal DNA (ITS1, 5.8S rDNA and ITS2). Acremonium sp., the other causal pathogen, differs from P. oratosquillae by its fast growth on PYGS agar, pale orange to salmon-colored colonies, long, slender conidiophores consisting of solitary phialides with tips lacking an undulate outline, and typically cylindrical conidia. Analysis of ITS and beta-tubulin gene sequences placed this fungus within the phylogenetically distinct Emericellopsis (anam. Acremonium) marine clade. Various physiological characteristics of both pathogens were also investigated. This is the first report of a fungal infection found on the mantis shrimp in Japan.

  2. Differential susceptibility of adults and nymphs of Blattella germanica (L.) (Blattodea: Blattellidae) to infection by Metarhizium anisopliae and assessment of delivery strategies.

    PubMed

    Lopes, R B; Alves, S B

    2011-01-01

    Microbial insecticides for cockroach control, such as those containing entomopathogenic fungi, may be an alternative to reduce contamination by chemicals in housing and food storage environments. Virulence of isolate ESALQ1037 belonging to the Metarhizium anisopliae complex against nymphs and adults of Blattella germanica (L.), and its infectivity following exposure of insects to a contaminated surface or to M. anisopliae-bait were determined under laboratory conditions. Estimated LD50 15 d following topical inoculation was 2.69 x 10(5) conidia per adult, whereas for nymphs the maximum mortality was lower than 50%. Baits amended with M. anisopliae conidia had no repellent effect on targets; adult mortality was inferior to 25%, and nymphs were not susceptible. All conidia found in the digestive tract of M. anisopliae-bait fed cockroaches were unviable, and bait-treated insects that succumbed to fungal infection showed a typical mycelial growth on mouthparts and front legs, but not on the hind body parts. As opposed to baits, the use of a M. anisopliae powdery formulation for surface treatment was effective in attaining high mortality rates of B. germanica. Both nymphs and adults were infected when this delivery strategy was used, and mycelia growth occurred all over the body surface. Our results suggest that the development of powders or similar formulations of M. anisopliae to control B. germanica may provide faster and better results than some of the strategies based on baits currently available.

  3. The Developmentally Regulated alb1 Gene of Aspergillus fumigatus: Its Role in Modulation of Conidial Morphology and Virulence

    PubMed Central

    Tsai, Huei-Fung; Chang, Yun C.; Washburn, Ronald G.; Wheeler, Michael H.; Kwon-Chung, K. J.

    1998-01-01

    Aspergillus fumigatus, an important opportunistic pathogen which commonly affects neutropenic patients, produces conidia with a bluish-green color. We identified a gene, alb1, which is required for conidial pigmentation. The alb1 gene encodes a putative polyketide synthase, and disruption of alb1 resulted in an albino conidial phenotype. Expression of alb1 is developmentally regulated, and the 7-kb transcript is detected only during the conidiation stage. The alb1 mutation was found to block 1,3,6,8-tetrahydroxynaphthalene production, indicating that alb1 is involved in dihydroxynaphthalene-melanin biosynthesis. Scanning electron microscopy studies showed that the alb1 disruptant exhibited a smooth conidial surface, whereas complementation of the alb1 deletion restored the echinulate wild-type surface. Disruption of alb1 resulted in a significant increase in C3 binding on conidial surfaces, and the conidia of the alb1 disruptant were ingested by human neutrophils at a higher rate than were those of the wild type. The alb1-complemented strain producing bluish-green conidia exhibited inefficient C3 binding and neutrophil-mediated phagocytosis quantitatively similar to those of the wild type. Importantly, the alb1 disruptant had a statistically significant loss of virulence compared to the wild-type and alb1-complemented strains in a murine model. These results suggest that disruption of alb1 causes pleiotropic effects on conidial morphology and fungal virulence. PMID:9620950

  4. Secreted Aspergillus fumigatus Protease Alp1 Degrades Human Complement Proteins C3, C4, and C5▿

    PubMed Central

    Behnsen, Judith; Lessing, Franziska; Schindler, Susann; Wartenberg, Dirk; Jacobsen, Ilse D.; Thoen, Marcel; Zipfel, Peter F.; Brakhage, Axel A.

    2010-01-01

    The opportunistic human pathogenic fungus Aspergillus fumigatus is a major cause of fungal infections in immunocompromised patients. Innate immunity plays an important role in the defense against infections. The complement system represents an essential part of the innate immune system. This cascade system is activated on the surface of A. fumigatus conidia and hyphae and enhances phagocytosis of conidia. A. fumigatus conidia but not hyphae bind to their surface host complement regulators factor H, FHL-1, and CFHR1, which control complement activation. Here, we show that A. fumigatus hyphae possess an additional endogenous activity to control complement activation. A. fumigatus culture supernatant efficiently cleaved complement components C3, C4, C5, and C1q as well as immunoglobulin G. Secretome analysis and protease inhibitor studies identified the secreted alkaline protease Alp1, which is present in large amounts in the culture supernatant, as the central molecule responsible for this cleavage. An alp1 deletion strain was generated, and the culture supernatant possessed minimal complement-degrading activity. Moreover, protein extract derived from an Escherichia coli strain overproducing Alp1 cleaved C3b, C4b, and C5. Thus, the protease Alp1 is responsible for the observed cleavage and degrades a broad range of different substrates. In summary, we identified a novel mechanism in A. fumigatus that contributes to evasion from the host complement attack. PMID:20498262

  5. Antifungal activity of β-carbolines on Penicillium digitatum and Botrytis cinerea.

    PubMed

    Olmedo, Gabriela M; Cerioni, Luciana; González, M Micaela; Cabrerizo, Franco M; Rapisarda, Viviana A; Volentini, Sabrina I

    2017-04-01

    β-carbolines (βCs) are alkaloids widely distributed in nature that have demonstrated antimicrobial properties. Here, we tested in vitro six βCs against Penicillium digitatum and Botrytis cinerea, causal agents of postharvest diseases on fruit and vegetables. Full aromatic βCs (harmine, harmol, norharmane and harmane) exhibited a marked inhibitory effect on conidia germination at concentrations between 0.5 and 1 mM, while dihydro-βCs (harmalina and harmalol) only caused germination delay. Harmol showed the highest inhibitory effect on both fungal pathogens. After 24 h of exposure to 1 mM harmol, conidia revealed a severe cellular damage, exhibiting disorganized cytoplasm and thickened cell wall. Harmol antimicrobial effect was fungicidal on B. cinerea, while it was fungistatic on P. digitatum. Conidia membrane permeabilization was detected in treatments with harmol at sub-inhibitory and inhibitory concentrations, for both pathogens. In addition, residual infectivity of P. digitatum on lemons and B. cinerea on blueberries was significantly reduced after exposure to this alkaloid. It also inhibited mycelial growth, preventing sporulation at the highest concentration tested. These results indicate that harmol might be a promising candidate as a new antifungal molecule to control causal agents of fruit diseases.

  6. VeA of Aspergillus niger increases spore dispersing capacity by impacting conidiophore architecture.

    PubMed

    Wang, Fengfeng; Dijksterhuis, Jan; Wyatt, Timon; Wösten, Han A B; Bleichrodt, Robert-Jan

    2015-01-01

    Aspergillus species are highly abundant fungi worldwide. Their conidia are among the most dominant fungal spores in the air. Conidia are formed in chains on the vesicle of the asexual reproductive structure called the conidiophore. Here, it is shown that the velvet protein VeA of Aspergillus niger maximizes the diameter of the vesicle and the spore chain length. The length and width of the conidiophore stalk and vesicle were reduced nearly twofold in a ΔveA strain. The latter implies a fourfold reduced surface area to develop chains of spores. Over and above this, the conidial chain length was approximately fivefold reduced. The calculated 20-fold reduction in formation of conidia by ΔveA fits the 8- to 17-fold decrease in counted spore numbers. Notably, morphology of the ΔveA conidiophores of A. niger was very similar to that of wild-type Aspergillus sydowii. This suggests that VeA is key in conidiophore architecture diversity in the fungal kingdom. The finding that biomass formation of the A. niger ΔveA strain was reduced twofold shows that VeA not only impacts dispersion capacity but also colonization capacity of A. niger.

  7. Nest sanitation through defecation: antifungal properties of wood cockroach feces.

    PubMed

    Rosengaus, Rebeca B; Mead, Kerry; Du Comb, William S; Benson, Ryan W; Godoy, Veronica G

    2013-11-01

    The wood cockroach Cryptocercus punctulatus nests as family units inside decayed wood, a substrate known for its high microbial load. We tested the hypothesis that defecation within their nests, a common occurrence in this species, reduces the probability of fungal development. Conidia of the entomopathogenic fungus, Metarhizium anisopliae, were incubated with crushed feces and subsequently plated on potato dextrose agar. Relative to controls, the viability of fungal conidia was significantly reduced following incubation with feces and was negatively correlated with incubation time. Although the cockroach's hindgut contained abundant β-1,3-glucanase activity, its feces had no detectable enzymatic function. Hence, these enzymes are unlikely the source of the fungistasis. Instead, the antifungal compound(s) of the feces involved heat-sensitive factor(s) of potential microbial origin. When feces were boiled or when they were subjected to ultraviolet radiation and subsequently incubated with conidia, viability was "rescued" and germination rates were similar to those of controls. Filtration experiments indicate that the fungistatic activity of feces results from chemical interference. Because Cryptocercidae cockroaches have been considered appropriate models to make inferences about the factors fostering the evolution of termite sociality, we suggest that nesting in microbe-rich environments likely selected for the coupling of intranest defecation and feces fungistasis in the common ancestor of wood cockroaches and termites. This might in turn have served as a preadaptation that prevented mycosis as these phylogenetically related taxa diverged and evolved respectively into subsocial and eusocial organizations.

  8. Control of sawtoothed grain beetles (Coleoptera: Silvanidae) in stored oats by using an entomopathogenic fungus in conjunction with seed resistance.

    PubMed

    Throne, James E; Lord, Jeffrey C

    2004-10-01

    We tested the hypothesis that the entomopathogenic fungus Beauveria bassiana would be more efficacious on oat cultivars that prolonged the immature developmental period of sawtoothed grain beetle, Oryzaephilus surinamensis (L.), a storage pest. However, percentage of reduction in progeny production was similar on whole 'Don' and 'Paul' oats treated with fungus, even though immature developmental time was longer on whole 'Don' than on 'Paul' oats. In our initial test at 10 mg of conidia per kilogram of oats, the number of beetle progeny produced was reduced by 38-67% in whole oats, and there was no effect of the fungus on insects developing on cracked oats. Therefore, we conducted two dose-response studies that showed that adding 150 mg of conidia per kilogram to cracked or whole 'Paul' oats resulted in a 70 and 98% reduction, respectively, in number of progeny produced. No further reduction was obtained by adding 200 mg of conidia per kilogram of cracked or whole 'Paul' oats. Presence of the fungus did not affect developmental time in any of our tests. A previous study showed that cleaned oats should limit insect population growth to allow long-term storage of oats without insect damage. However, the current study shows that if the oats are not cleaned, and not cleaning oats is the normal storage practice, then B. bassiana could be used to help control sawtoothed grain beetles.

  9. Potential of oil-based formulations of Beauveria bassiana to control Triatoma infestans.

    PubMed

    Luz, C; Batagin, I

    2005-08-01

    The in vitro development of Beauveria bassiana conidia was monitored when immersed in six concentrations of seven non-ionic (MP 6400, MP 600, Renex 60, Renex 95, Span 80, Tween 20 and Tween 80) and three anionic (DOS 75, Hostapaval BVQ 9 and Surfax 220) surfactants and 11 vegetable oils (linseed, soybean, groundnut, rapeseed, thistle, sunflower, olive, sesame, corn, castor, and babassu). The influence of the oils on the settling behavior of Triatoma infestans nymphs and the activity of an oil-water formulation of the fungus against this vector under laboratory and simulated field conditions were also determined. With exception of DOS 75 and Surfax 220 germination of conidia on complete medium was >98% at 24 h after exposure to surfactants up to 10%. Elevated rates of germination (>25%) were observed in 10% corn, thistle and linseed oil 8 days after incubation. Pure oils had a significant repellent effect to T. infestans. Repellency decreased generally at 10% of the oil and some oils showed some attractiveness for nymphs when tested at 1%. Nymphs were highly susceptible to oil-water formulated conidia, even at unfavorable moisture for extra-tegumental development of the fungus on the insect cuticle.

  10. The CarO rhodopsin of the fungus Fusarium fujikuroi is a light-driven proton pump that retards spore germination.

    PubMed

    García-Martínez, Jorge; Brunk, Michael; Avalos, Javier; Terpitz, Ulrich

    2015-01-15

    Rhodopsins are membrane-embedded photoreceptors found in all major taxonomic kingdoms using retinal as their chromophore. They play well-known functions in different biological systems, but their roles in fungi remain unknown. The filamentous fungus Fusarium fujikuroi contains two putative rhodopsins, CarO and OpsA. The gene carO is light-regulated, and the predicted polypeptide contains all conserved residues required for proton pumping. We aimed to elucidate the expression and cellular location of the fungal rhodopsin CarO, its presumed proton-pumping activity and the possible effect of such function on F. fujikuroi growth. In electrophysiology experiments we confirmed that CarO is a green-light driven proton pump. Visualization of fluorescent CarO-YFP expressed in F. fujikuroi under control of its native promoter revealed higher accumulation in spores (conidia) produced by light-exposed mycelia. Germination analyses of conidia from carO(-) mutant and carO(+) control strains showed a faster development of light-exposed carO(-) germlings. In conclusion, CarO is an active proton pump, abundant in light-formed conidia, whose activity slows down early hyphal development under light. Interestingly, CarO-related rhodopsins are typically found in plant-associated fungi, where green light dominates the phyllosphere. Our data provide the first reliable clue on a possible biological role of a fungal rhodopsin.

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

    PubMed

    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.

  12. Metarhizium brunneum Blastospore Pathogenesis in Aedes aegypti Larvae: Attack on Several Fronts Accelerates Mortality

    PubMed Central

    Alkhaibari, Abeer M.; Carolino, Aline T.; Yavasoglu, Sare I.; Maffeis, Thierry; Mattoso, Thalles C.; Bull, James C.; Samuels, Richard I.; Butt, Tariq M.

    2016-01-01

    Aedes aegypti is the vector of a wide range of diseases (e.g. yellow fever, dengue, Chikungunya and Zika) which impact on over half the world’s population. Entomopathogenic fungi such as Metarhizium anisopliae and Beauveria bassiana have been found to be highly efficacious in killing mosquito larvae but only now are the underlying mechanisms for pathogenesis being elucidated. Recently it was shown that conidia of M. anisopliae caused stress induced mortality in Ae. aegypti larvae, a different mode of pathogenicity to that normally seen in terrestrial hosts. Blastospores constitute a different form of inoculum produced by this fungus when cultured in liquid media and although blastospores are generally considered to be more virulent than conidia no evidence has been presented to explain why. In our study, using a range of biochemical, molecular and microscopy methods, the infection process of Metarhizium brunneum (formerly M. anisopliae) ARSEF 4556 blastospores was investigated. It appears that the blastospores, unlike conidia, readily adhere to and penetrate mosquito larval cuticle. The blastospores are readily ingested by the larvae but unlike the conidia are able infect the insect through the gut and rapidly invade the haemocoel. The fact that pathogenicity related genes were upregulated in blastospores exposed to larvae prior to invasion, suggests the fungus was detecting host derived cues. Similarly, immune and defence genes were upregulated in the host prior to infection suggesting mosquitoes were also able to detect pathogen-derived cues. The hydrophilic blastospores produce copious mucilage, which probably facilitates adhesion to the host but do not appear to depend on production of Pr1, a cuticle degrading subtilisin protease, for penetration since protease inhibitors did not significantly alter blastospore virulence. The fact the blastospores have multiple routes of entry (cuticle and gut) may explain why this form of the inoculum killed Ae. aegypti

  13. Differentiation of beauveria bassiana isolates from the darkling beetle, alphitobius diaperinus, using isozyme and RAPD analyses

    PubMed

    Castrillo; Brooks

    1998-11-01

    Two natural genetic markers, isozymes and RAPD, were utilized to differentiate 24 strains of Beauveria bassiana (Deuteromycotina: Hyphomycetes) collected from the darkling beetle, Alphitobius diaperinus (Coleoptera: Tenebrionidae), from poultry houses in North Carolina and West Virginia. Nine enzyme systems were screened, of which alkaline phosphatase, alpha- and beta-esterase, and glucose phosphate isomerase gave well-resolved, scorable bands. A total of 26 isozyme bands was generated by these four enzymes which partitioned the 24 strains into 14 classes. Three classes were shared by two or more strains while the rest of the strains had distinct electrophoretic profiles. Ten RAPD primers, selected from 72 that were screened, produced 141 bands from the 24 strains and separated each as a unique class. While both systems were able to detect variation present among the 24 strains from different regions in North Carolina and West Virginia, RAPD markers provided better resolution of the differences between strains. Variation was detected not only within and among strains from different regions but also among strains collected from a given insect host. Copyright 1998 Academic Press.

  14. Genetic variation in Beauveria bassiana populations associated with the darkling beetle, Alphitobius diaperinus.

    PubMed

    Castrillo, L A; Wiegmann, B M; Brooks, W M

    1999-05-01

    A study was conducted to assess genetic variation within and among populations of Beauveria bassiana (Deuteromycotina: Hyphomycetes) associated with the darkling beetle, Alphitobius diaperinus (Coleoptera: Tenebrionidae), using RAPD markers. A hierarchical collection of samples (strains from the same insect specimen, from insects from the same location, and from insects from different locations) was obtained from infected beetles from North Carolina (NC) and West Virginia (WV), USA. Ten primers resolved 81 strains into 80 distinct multiband phenotypes reflecting the substantial amount of variation that was present. Variation present within populations was evident not only in the separation of each strain as a distinct multiband phenotype but also in the separation of strains within a population into separate clusters. Among populations, a group sharing more than 89% similarity was observed among all the strains from Martin Co. and Greene Co., NC and 61% of the strains collected from WV. Some genetic differentiation was present among the other populations but the separation was not distinct with a few strains from some populations showing greater affinity to strains from other collection sites.

  15. Dependence of the entomopathogenic fungus, Beauveria bassiana, on high humidity for infection of Rhodnius prolixus.

    PubMed

    Luz, C; Fargues, J

    1999-01-01

    The impact of relative humidity (RH) on the infective potential of the isolate Bb INRA 297 of Beauveria bassiana (Bals.) Vuillemin (Deuteromycotina: Hyphomycetes) against first instar nymphs of Rhodnius prolixus Stål. (Hemiptera: Reduviidae) was determined. Fungus-treated insects were exposed to RHs ranged from 75 to 100% at 25 degrees C. Results clearly showed a threshold of humidity at ca. 96% for high and rapid mortality. After initial exposure to increasing periods of 97% (4, 8, 16, 24, 36 and 48 h) and subsequent transfer to constant lower RHs (43, 53, 75 and 86%) at a constant 25 degrees C, an incubation of at least 48 h at 97% RH was necessary to kill all insects. On changing RHs of 97/75% and different regimes of temperature (15/28 degrees C, 20/25 degrees C, 25/28 degrees C, and 25/35 degrees C), at least 72 h of initial exposure at 97% RH for the 15/28 degrees C regime, 48 h for the 20 degrees/25 degrees C and 25/28 degrees C regimes and 36 h for 25/35 degrees C were needed to kill all insects over a 6-day incubation time. Delayed exposure to favorable moisture condition (97% RH), significantly affected infection for up to a 3-day delay within the various temperature-humidity regimes tested.

  16. Efficiency of uronic acid uptake in marine alginate-degrading fungi

    NASA Astrophysics Data System (ADS)

    Schaumann, K.; Weide, G.

    1995-03-01

    Despite the fact that many marine fungi, including phycomycetes, yeasts, ascomycetes and hyphomycetes, have been recorded from living and/or dead phaeophytes, only a few of these have been shown to be capable of degrading alginic acid or alginates. The degradation is achieved by the action of an exoenzyme complex, comprising alginate lyase, as well as alginate hydrolase activities. The latter was detected only recently by the authors. In this study, the growth of two marine sodiumalginate-degrading deuteromycetes, Asteromyces cruciatus and Dendryphiella salina, was investigated, and the assimilation efficiency of sodiumalginate and its uronic acid degradation products, respectively, was estimated from the economic coefficient (E). E is calculated from the mycelial dry weight, divided by the weight of substrate consumed for this production. The economic coefficient for A. cruciatus was 48.6%, and that of D. salina 38.9%. This indicates that the former species uses the alginate degradation products more efficiently than the latter. The observed E-values for the marine deuteromycetes agree with those from other fungi, e.g. terrestrial species. In general, it is concluded that the marine fungi appear to play a more important role in kelp-based ecosystems than was realized previously.

  17. Fungal Planet description sheets: 128-153.

    PubMed

    Crous, P W; Shivas, R G; Wingfield, M J; Summerell, B A; Rossman, A Y; Alves, J L; Adams, G C; Barreto, R W; Bell, A; Coutinho, M L; Flory, S L; Gates, G; Grice, K R; Hardy, G E St J; Kleczewski, N M; Lombard, L; Longa, C M O; Louis-Seize, G; Macedo, F; Mahoney, D P; Maresi, G; Martin-Sanchez, P M; Marvanová, L; Minnis, A M; Morgado, L N; Noordeloos, M E; Phillips, A J L; Quaedvlieg, W; Ryan, P G; Saiz-Jimenez, C; Seifert, K A; Swart, W J; Tan, Y P; Tanney, J B; Thu, P Q; Videira, S I R; Walker, D M; Groenewald, J Z

    2012-12-01

    Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae from Carpentaria, Phaeococcomyces eucalypti from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria. Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand), Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal), Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliae-fistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided.

  18. Selective feeding by shredders on leaf-colonizing stream fungi: comparison of macroinvertebrate taxa.

    PubMed

    Arsuffi, T L; Suberkropp, K

    1989-04-01

    Laboratory experiments were conducted to examine the effects of fungal species composition of leaf detritus on the feeding of distantly related macroinvertebrate shredders. Preferences of shredders representing three orders of insects (Diptera: Tipulidae; Plecoptera: Pteronarcidae; Trichoptera: Limnephilidae and Calamatoceridae) and one each of gastropods (Basommatophora: Planorbidae) and crustaceans (Amphipoda: Gammaridae) were compared. Shredder preferences were based on consumption of leaves separately colonized by one of eight species of aquatic hyphomycetes. The feeding patterns of the invertebrates ranged from lack of feeding to heavy consumption of fungal-colonized leaves. Where consumption occurred, rank orders of preference and degree of selectivity differed among invertebrate shredders. Differences in preferences together with relationships between degree of selectivity and the relative mobility and digestive specializations exhibited by shredders suggest that the exploitation of fungal-colonized leaf detritus by different taxa is affected by phylogenetic constraints. Our results suggest that fungal species composition affects the feeding of a variety of shredders and that fungal species composition may be as important as degree of conditioning in determining food selection by shredders.

  19. Surprising spectra of root-associated fungi in submerged aquatic plants.

    PubMed

    Kohout, Petr; Sýkorová, Zuzana; Ctvrtlíková, Martina; Rydlová, Jana; Suda, Jan; Vohník, Martin; Sudová, Radka

    2012-04-01

    Similarly to plants from terrestrial ecosystems, aquatic species harbour wide spectra of root-associated fungi (RAF). However, comparably less is known about fungal diversity in submerged roots. We assessed the incidence and diversity of RAF in submerged aquatic plants using microscopy, culture-dependent and culture-independent techniques. We studied RAF of five submerged isoetid species collected in four oligotrophic freshwater lakes in Norway. Levels of dark septate endophytes (DSE) colonization differed among the lakes and were positively related to the organic matter content and negatively related to pH. In total, we identified 41 fungal OTUs using culture-dependent and culture-independent techniques, belonging to Mucoromycotina, Chytridiomycota, Glomeromycota, Ascomycota as well as Basidiomycota. Sequences corresponding to aquatic hyphomycetes (e.g. Nectria lugdunensis, Tetracladium furcatum and Varicosporium elodeae) were obtained. Eight arbuscular mycorrhizal taxa belonging to the orders Archaeosporales, Diversisporales and Glomerales were also detected. However, the vast majority of the fungal species detected (e.g. Ceratobasidium sp., Cryptosporiopsis rhizophila, Leptodontidium orchidicola, and Tuber sp.) have previously been known only from roots of terrestrial plants. The abundance and phylogenetic distribution of mycorrhizal as well as nonmycorrhizal fungi in the roots of submerged plants have reshaped our views on the fungal diversity in aquatic environment.

  20. A technique for the prevention of greenhouse whitefly (Trialeurodes vaporariorum) using the entomopathogenic fungus Beauveria bassiana M130.

    PubMed

    Kim, Chang-Su; Lee, Jung-Bok; Kim, Beam-Soo; Nam, Young-Ho; Shin, Kee-Sun; Kim, Jin-Won; Kim, Jang-Eok; Kwon, Gi-Seok

    2014-01-01

    The possibility of using hyphomycete fungi as suitable biocontrol agents against greenhouse whitefly has led to the isolation of various insect pathogenic fungi. Among them is Beauveria bassiana, one of the most studied entomopathogenic fungi. The objective of this study was to use B. bassiana M130 as an insecticidal agent against the greenhouse whitefly. M130 isolated from infected insects is known to be a biocontrol agent against greenhouse whitefly. Phylogenetic classification of M130 was determined according to its morphological features and 18S rRNA sequence analysis. M130 was identified as B. bassiana M130 and showed chitinase (342.28 units/ml) and protease (461.70 units/ml) activities, which were involved in the invasion of the host through the outer cuticle layer, thus killing them. The insecticidal activity was 55.2% in petri-dish test, 84.6% in pot test, and 45.3% in field test. The results of this study indicate that B. bassiana has potential as a biological agent for the control of greenhouse whitefly to replace chemical pesticides.

  1. The effects of motorway runoff on freshwater ecosystems. 1: Field study

    SciTech Connect

    Maltby, L.; Forrow, D.M.; Boxall, A.B.A.; Calow, P.; Betton, C.I.

    1995-06-01

    The effects of motorway runoff on the water quality, sediment quality, and biota of small streams were investigated over a 12-month period. Downstream of motorway runoff discharges there was an increase in the sediment concentrations of total hydrocarbons, aromatic hydrocarbons, and heavy metals and an increase in the water concentrations of heavy metals and selected anions. Hydrocarbon contamination of sediments was positively correlated with potential contaminant loading (i.e., length of road drained/stream size). The greatest effect was observed at Pigeon Bridge Brook, a small stream receiving drainage from a 1,500-m stretch of the M1 motorway. The dominant PAHs in contaminated sediment at this site were phenanthrene, pyrene, and fluoranthene, whereas the dominant metals were zinc, cadmium, chromium, and lead. Differences between the station upstream and downstream of discharges in the diversity and composition of the macroinvertebrate assemblages were detected in four out of the seven streams surveyed. However, there was no evidence of an effect on either the diversity of abundance of epilithic algae. The diversity of the aquatic hyphomycete assemblage was only affected at the most impacted site. Reductions in macroinvertebrate diversity were associated with reductions in the processing of leaf litter and a change from an assemblage based on benthic algae and coarse particulate organic matter to one dependent upon fine particulate organic matter.

  2. New remarkable records of microfungi from Sardinia (Italy).

    PubMed

    Jensen, M; Nerat, N; Ale-Agha, N

    2010-01-01

    In June 2009 we organized a botanical student excursion to the eastern part of Sardinia, Italy. On this occasion we were able to collect and identify over 80 species of microfungi growing on higher plants. The collecting sites were spread over a large area, among them were La Caletta, Capo Comino, Monte Albo, Cala Gonone, Monte Maccione, San Teodoro, Capo Testa. The collected microfungi were parasitic or saprophytic; Basidiomycotina (Uredinales), Ascomycotina and Deuteromycotina (Hyphomycetes, Coelomycetes) were predominant. Examples are Pezicula corticola (Jörg.) NANNF. (new for Sardinia), on Pyrus communis. Puccinia chamaecyparissi TROTT. (new for Sardinia), on Santolina insularis. Sphaceloma oleae CICC. and GRANITI (new for Sardinia) and Phlyctema vagabunda DESM. (new for Sardinia), on Olea europaea and Arbutus unedo. Puccinia pseudosphaeria MONT. (new for Sardinia), on Sonchus oleraceus. Discula umbrinella (BERK. and BR.) SUTTON (new for Sardinia)(D. quercina WEST. and BARK), on Quercus coccifera. Zaghouania phillyreae PAT. (new for Sardinia), on Phillyrea angustifolia. Phymatotrichum omnivorum (DUGGAR) HENNEBERT, new on Verbascum thapsus for Sardinia. Guignardia punctoidea (COOKE) SCHROTER (new for Sardinia), on Quercus ilex. Many of the collected species are rare or unknown for the area of investigation until now. All specimens are located in the Herbarium ESS, Mycotheca Parva collection G.B. Feige and N. Ale-Agha.

  3. Endophytic Fungal Flora from Roots and Fruits of an Indian Neem Plant Azadirachta indica A. Juss., and Impact of Culture Media on their Isolation.

    PubMed

    Verma, Vijay C; Gond, Surendra K; Kumar, Anuj; Kharwar, Ravindra N; Boulanger, Lori-Ann; Strobel, Gary A

    2011-10-01

    Azadirachta indica A. Juss. (neem), native to India, is well known worldwide for its insecticidal and ethanopharmacological properties. Although endophytic microbes are known from this plant as only leaves and stems were the subjects of past reports. Now, a variety of procedures and a number of different media were used to isolate the maximum number of endophytic fungi from unripe fruits and roots. A total of 272 isolates of 29 filamentous fungal taxa were isolated at rate of 68.0% from 400 samples of three different individual trees (at locations-Az1, Az2, Az3). Mycological agar (MCA) medium yielded the highest number of isolates (95, with a 14.50% isolation rate) with the greatest species richness. Mycelia Sterilia (1, 2, 3) accounted for 11.06%, Coelomycetes 7.25%, while Hyphomycetes showed the maximum number of representative isolates (81.69%). Mycelia-Sterilia (1, 2, 3), based on their 5.8S ITS 1, ITS2 and partial 18S and 28S rDNA sequences were identified as Fusarium solani (99%), Chaetomium globosum (93%) and Chaetomium globosum (93%) respectively. Humicola, Drechslera, Colletotrichum, and Scytalidium sp. were some of the peculiar fungal endophytes recovered from this plant.

  4. Identification of a new species of Cercospora causing leaf spot disease in Capsicum assamicum in northeastern India.

    PubMed

    Meghvansi, Mukesh K; Khan, Mohammad Haneef; Gupta, Rajeev; Veer, Vijay

    2013-11-01

    Northeastern India is one of the most important biodiversity hotspots in the world. However, hot and humid climatic conditions of the region favor growth and development of foliar fungal phytopathogens such as cercosporoid fungi. The genus Cercospora is one of the largest genera of hyphomycetes. Species of Cercospora are known to cause leaf spot disease in several cultivated and non-cultivated plants leading to considerable losses. In this study, we describe a new species of Cercospora which was isolated from the leaves of Naga chilli (Capsicum assamicum Purkayastha & Singh) grown in northeastern India. Comparison of the detailed morphological characteristics along with the DNA sequences for four gene regions, namely actin, calmodulin, histone H3 and translation elongation factor-1α of this isolate, was made with those of some previously reported Cercospora species infecting Capsicum and other similar species of Cercospora from other hosts. The results suggested that our isolate represents an undescribed taxon and warrants the establishment of a new species, Cercospora tezpurensis sp. nov.

  5. A dark strain in the Fusarium solani species complex isolated from primary subcutaneous sporotrichioid lesions associated with traumatic inoculation via a rose bush thorn.

    PubMed

    Kantarcioglu, A Serda; Summerbell, Richard C; Sutton, Deanna A; Yücell, Ayhan; Sarikaya, Ebru; Kaner, Gültekin; Iscimen, Aydin; Altas, Kemal

    2010-02-01

    Fusarium species are hyaline hyphomycetes widely distributed in nature and documented agents of both superficial and systemic infections in humans. In this paper, we report a darkly-pigmented and initially non-sporulating isolate in the Fusarium solani species complex (FSSC) causing a post-traumatic sporotrichoid infection in an otherwise healthy, male patient. Sequencing of multiple loci showed that the isolate represented an otherwise unknown lineage, possibly corresponding to a separate species, within the multi-species F. solani complex. In prolonged culture, the non-sporulating isolate produced revertant wild-type subcultures with typical Fusarium conidiation. This suggests that the original dense, dark, non-sporulating isolate was a host-adapted form selected in vivo for characters compatible with human pathogenicity. The production of such forms by Fusarium species is increasingly recognized now that sequencing has allowed the identification of highly atypical isolates. In vitro antifungal susceptibility of the isolate was investigated against seven conventional and two newly approved antifungal agents. The isolate showed in vitro resistance to amphotericin B, but appeared susceptible to itraconazole and terbinafine. A cure was ultimately achieved with combined terbinafine/itraconazole therapy with prolonged itraconazole follow-up therapy.

  6. The Utility of Decomposition and Associated Microbial Parameters to Assess Changes in Stream Ecosystems due to Eutrophication

    NASA Astrophysics Data System (ADS)

    Gulis, V.; Ferreira, V. J.; Graca, M. A.

    2005-05-01

    Traditional approaches to assess stream ecosystem health rely on structural parameters, e.g. a variety of biotic indices. The goal of the Europe-wide RivFunction project is to develop methodology that uses functional parameters (e.g. plant litter decomposition) to this end. Here we report on decomposition experiments carried out in Portugal in five pairs of streams that differed in dissolved inorganic nutrients. On average, decomposition rates of alder and oak leaves were 2.8 and 1.4 times higher in high nutrient streams in coarse and fine mesh bags, respectively, than in corresponding reference streams. Breakdown rate correlated better with stream water SRP concentration rather than TIN. Fungal biomass and sporulation rates of aquatic hyphomycetes associated with decomposing leaves were stimulated by higher nutrient levels. Both fungal parameters measured at very early stages of decomposition (e.g. days 7-13) correlated well with overall decomposition rates. Eutrophication had no significant effect on shredder abundances in leaf bags but species richness was higher in disturbed streams. Decomposition is a key functional parameter in streams integrating many other variables and can be useful in assessing stream ecosystem health. We also argue that because decomposition is often controlled by fungal activity, microbial parameters can also be useful in bioassessment.

  7. Severe osteomyelitis caused by Myceliophthora thermophila after a pitchfork injury

    PubMed Central

    Destino, Lauren; Sutton, Deanna A; Helon, Anna L; Havens, Peter L; Thometz, John G; Willoughby, Rodney E; Chusid, Michael J

    2006-01-01

    Background Traumatic injuries occurring in agricultural settings are often associated with infections caused by unusual organisms. Such agents may be difficult to isolate, identify, and treat effectively. Case report A 4-year-old boy developed an extensive infection of his knee and distal femur following a barnyard pitchfork injury. Ultimately the primary infecting agent was determined to be Myceliophthora thermophila, a thermophilic melanized hyphomycete, rarely associated with human infection, found in animal excreta. Because of resistance to standard antifungal agents including amphotericin B and caspofungin, therapy was instituted with a prolonged course of terbinafine and voriconazole. Voriconazole blood levels demonstrated that the patient required a drug dosage (13.4 mg/kg) several fold greater than that recommended for adults in order to attain therapeutic blood levels. Conclusion Unusual pathogens should be sought following traumatic farm injuries. Pharmacokinetic studies may be of critical importance when utilizing antifungal therapy with agents for which little information exists regarding drug metabolism in children. PMID:16961922

  8. Anti-HIV activity in vitro of MGN-3, an activated arabinoxylane from rice bran.

    PubMed

    Ghoneum, M

    1998-02-04

    MGN-3 an arabinoxylane from rice bran that has been enzymatically modified with extract from Hyphomycetes mycelia, was tested for anti-HIV activity in vitro. MGN-3 activity against HIV-1 (SF strain) was examined in primary cultures of peripheral blood mononuclear cells. MGN-3 inhibited HIV-1 replication by: (1) inhibition of HIV-1 p24 antigen production in a dose dependent manner--MGN-3 concentrations of 12.5, 25, 50, and 100 micrograms/ml showed 18.3, 42.8, 59, and 75% reduction in p24 antigen, respectively; and (2) inhibition of syncytia formation maximized (75%) at concentrations of 100 micrograms/ml. Further studies showed that ingestion of MGN-3 at concentration of 15 mg/kg/day resulted in a significant increase in T and B cell mitogen response at 2 months after treatment: 146% for PHA, 140% for Con A, and 136.6% for PWM mitogen. We conclude that MGN-3 possesses potent anti-HIV activity and in the absence of any notable side effects, MGN-3 shows promise as an agent for treating patients with AIDS.

  9. A molecular, morphological and ecological re-appraisal of Venturiales—a new order of Dothideomycetes

    PubMed Central

    Zhang, Ying; Crous, Pedro W.; Schoch, Conrad L.; Bahkali, Ali H.; Guo, Liang Dong

    2012-01-01

    The Venturiaceae was traditionally assigned to Pleosporales although its diagnostic characters readily distinguish it from other pleosporalean families. These include a parasitic or saprobic lifestyle, occurring on leaves or stems of dicotyledons; small to medium-sized ascomata, often with setae; deliquescing pseudoparaphyses; 8-spored, broadly cylindrical to obclavate asci; 1-septate, yellowish, greenish or pale brown to brown ascospores; and hyphomycetous anamorphs. Phylogenetically, core genera of Venturiaceae form a monophyletic clade within Dothideomycetes, and represent a separate sister lineage from current orders, thus a new order—Venturiales is introduced. A new family, Sympoventuriaceae, is introduced to accommodate taxa of a well-supported subclade within Venturiales, which contains Sympoventuria, Veronaeopsis simplex and Fusicladium-like species. Based on morphology and DNA sequence analysis, eight genera are included in Venturiaceae, viz. Acantharia, Apiosporina (including Dibotryon), Caproventuria, Coleroa, Pseudoparodiella, Metacoleroa, Tyrannosorus and Venturia. Molecular phylogenetic information is lacking for seven genera previously included in Venturiales, namely Arkoola, Atopospora, Botryostroma, Lasiobotrys, Trichodothella, Trichodothis and Rhizogenee and these are discussed, but their inclusion in Venturiaceae is doubtful. Crotone, Gibbera, Lineostroma, Phaeocryptopus, Phragmogibbera, Platychora, Polyrhizon, Rosenscheldiella, Uleodothis and Xenomeris are excluded from Venturiales, and their ordinal placement needs further investigation. Zeuctomorpha is treated as a synonym of Acantharia. PMID:22368534

  10. Sexual Reproduction in Aspergillus flavus Sclerotia: Acquisition of Novel Alleles from Soil Populations and Uniparental Mitochondrial Inheritance

    PubMed Central

    Horn, Bruce W.; Gell, Richard M.; Singh, Rakhi; Sorensen, Ronald B.; Carbone, Ignazio

    2016-01-01

    Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. flavus is heterothallic and laboratory crosses between strains of the opposite mating type produce progeny showing genetic recombination. Sclerotia formed in crops are dispersed onto the soil surface at harvest and are predominantly produced by single strains of one mating type. Less commonly, sclerotia may be fertilized during co-infection of crops with sexually compatible strains. In this study, laboratory and field experiments were performed to examine sexual reproduction in single-strain and fertilized sclerotia following exposure of sclerotia to natural fungal populations in soil. Female and male roles and mitochondrial inheritance in A. flavus were also examined through reciprocal crosses between sclerotia and conidia. Single-strain sclerotia produced ascospores on soil and progeny showed biparental inheritance that included novel alleles originating from fertilization by native soil strains. Sclerotia fertilized in the laboratory and applied to soil before ascocarp formation also produced ascospores with evidence of recombination in progeny, but only known parental alleles were detected. In reciprocal crosses, sclerotia and conidia from both strains functioned as female and male, respectively, indicating A. flavus is hermaphroditic, although the degree of fertility depended upon the parental sources of sclerotia and conidia. All progeny showed maternal inheritance of mitochondria from the sclerotia. Compared to A. flavus populations in crops, soil populations would provide a higher likelihood of exposure of sclerotia to sexually compatible strains and a more diverse source of genetic material for outcrossing. PMID:26731416

  11. A morphological and phylogenetic revision of the Nectria cinnabarina species complex

    PubMed Central

    Hirooka, Y.; Rossman, A.Y.; Chaverri, P.

    2011-01-01

    The genus Nectria is typified by N. cinnabarina, a wood-inhabiting fungus common in temperate regions of the Northern Hemisphere. To determine the diversity within N. cinnabarina, specimens and cultures from Asia, Europe, and North America were obtained and examined. Their phylogeny was determined using sequences of multiple loci, specifically act, ITS, LSU, rpb1, tef1, and tub. Based on these observations, four species are recognised within the N. cinnabarina complex. Each species is delimited based on DNA sequence analyses and described and illustrated from specimens and cultures. The basionym for N. cinnabarina, Sphaeria cinnabarina, is lectotypified based on an illustration that is part of the protologue, and an epitype specimen is designated. Nectria cinnabarina s. str. is recircumscribed as having 2-septate ascospores and long stipitate sporodochia. Nectria dematiosa, previously considered a synonym of N. cinnabarina, has up to 2-septate ascospores and sessile sporodochia or no anamorph on the natural substrate. A third species, Nectria nigrescens, has up to 3-septate ascospores and short to long stipitate sporodochia. One newly described species, Nectria asiatica with a distribution restricted to Asia, has (0–)1-septate ascospores and short stipitate sporodochia. Young and mature conidia developing on SNA were observed for each species. Mature conidia of N. asiatica, N. cinnabarina, and N. nigrescens but not N. dematiosa bud when the mature conidia are crowded. On PDA the optimal temperature for growth for N. dematiosa is 20 °C, while for the other three species it is 25 °C. Based on our phylogenetic analyses, three subclades are evident within N. dematiosa. Although subtle culture and geographical differences exist, these subclades are not recognised as distinct species because the number of samples is small and the few specimens are insufficient to determine if morphological differences exist in the natural environment. PMID:21523188

  12. Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease?

    PubMed

    Moser, John C; Konrad, Heino; Blomquist, Stacy R; Kirisits, Thomas

    2010-02-01

    Dutch elm disease (DED) is a destructive vascular wilt disease of elm (Ulmus) trees caused by the introduced Ascomycete fungus Ophiostoma novo-ulmi. In Europe, this DED pathogen is transmitted by elm bark beetles in the genus Scolytus. These insects carry phoretic mites to new, suitable habitats. The aim of this study was to record and quantify conidia and ascospores of O. novo-ulmi on phoretic mites on the three elm bark beetle species Scolytus multistriatus, Scolytus pygmaeus, and Scolytus scolytus. Spores of O. novo-ulmi were found on four of the ten mite species phoretic on Scolytus spp. These included Elattoma fraxini, Proctolaelaps scolyti, Pseudotarsonemoides eccoptogasteri, and Tarsonemus crassus. All four species had spores attached externally to their body surfaces. However, T. crassus carried most spores within its sporothecae, two paired pocket-like structures adapted for fungal transmission. Individuals of Pr. scolyti also had O. novo-ulmi conidia and ascospores frequently in their digestive system, where they may remain viable. While E. fraxini and P. eccoptogasteri rarely had spores attached to their bodies, large portions of Pr. scolyti and T. crassus carried significant numbers of conidia and/or ascospores of O. novo-ulmi. P. scolyti and T. crassus, which likely are fungivores, may thus contribute to the transmission of O. novo-ulmi, by increasing the spore loads of individual Scolytus beetles during their maturation feeding on twigs of healthy elm trees, enhancing the chance for successful infection with the pathogen. Only S. scolytus, which is the most efficient vector of O. novo-ulmi in Europe, carried high numbers of Pr. scolyti and T. crassus, in contrast to S. multistriatus and S. pygmaeus, which are known as less efficient vectors. The high efficiency of S. scolytus in spreading Dutch elm disease may be partly due to its association with these two mites and the hyperphoretic spores of O. novo-ulmi they carry.

  13. Suppression of Pythium spp. by Trichoderma spp. during germination of tomato seeds in soilless growing media.

    PubMed

    Aerts, R; De Schutter, B; Rombouts, L

    2002-01-01

    In the Flemish horticulture Pythium spp. is an important pathogen of tomato plants (Lycopersicon esculenthum) in soilless growing media. Therefore some experiments were conducted to evaluate the possibility of decreasing the damage caused by Pythium spp. by Trichoderma spp. In a tray with several growing media, a suspension of Trichoderma conidia (10(6)/ml growing medium) was applied two weeks before sowing. On some objects, a compost extract (Biostimulus) was added. The growing media used in the experiment were rockwool, recycled rockwool and recycled coconut fibre. After sowing, the trays were covered with perlite. Three isolates of Trichoderma spp.: T. asperellum (Biofungus), T. harzianum (Tri 003) and Trichoderma sp. (KHK) and two isolates of Pythium spp.: P. ultimum (MUCL) en P. aphanidermatum (HRI, UK) were used. Propamocarb was used as a chemical standard. The use of coconut fibre growing medium resulted in a higher percentage (36%) of germination than the rockwool media when only Pythium spp. was used. The presence of the spontaneous developing microflora in the coconut fibre medium gave probably also a suppression of Pythium spp. For that reason the results of the suppression by Trichoderma spp. are not easy to explain and very variable on the different objects. Pythium ultimum was more suppressed than P. aphanidermatum on all the growing media and the application of all the Trichoderma isolates increased the germination percentage of tomato seeds. T. asperellum (Biofungus) gave on rockwool also a good result for the suppression of P. aphanidermatum (increasing of germination with 48%). This effect was comparable with the propamocarb treatment (48%). T. harzianum (Tri 003) gave a small suppression (22%) and Trichoderma sp. (KHK) gave almost no suppression of P. aphanidermatum (7%). When less Trichoderma conidia were applied the germination percentage decreased. The adding of a compost extract (Biostimulus) had no influence on the results. This experiment

  14. Production of Extracellular Traps against Aspergillus fumigatus In Vitro and in Infected Lung Tissue Is Dependent on Invading Neutrophils and Influenced by Hydrophobin RodA

    PubMed Central

    Aimanianda, Vishukumar; Nietzsche, Sandor; Thywißen, Andreas; Jeron, Andreas; Latgé, Jean-Paul; Brakhage, Axel A.; Gunzer, Matthias

    2010-01-01

    Aspergillus fumigatus is the most important airborne fungal pathogen causing life-threatening infections in immunocompromised patients. Macrophages and neutrophils are known to kill conidia, whereas hyphae are killed mainly by neutrophils. Since hyphae are too large to be engulfed, neutrophils possess an array of extracellular killing mechanisms including the formation of neutrophil extracellular traps (NETs) consisting of nuclear DNA decorated with fungicidal proteins. However, until now NET formation in response to A. fumigatus has only been demonstrated in vitro, the importance of neutrophils for their production in vivo is unclear and the molecular mechanisms of the fungus to defend against NET formation are unknown. Here, we show that human neutrophils produce NETs in vitro when encountering A. fumigatus. In time-lapse movies NET production was a highly dynamic process which, however, was only exhibited by a sub-population of cells. NETosis was maximal against hyphae, but reduced against resting and swollen conidia. In a newly developed mouse model we could then demonstrate the existence and measure the kinetics of NET formation in vivo by 2-photon microscopy of Aspergillus-infected lungs. We also observed the enormous dynamics of neutrophils within the lung and their ability to interact with and phagocytose fungal elements in situ. Furthermore, systemic neutrophil depletion in mice almost completely inhibited NET formation in lungs, thus directly linking the immigration of neutrophils with NET formation in vivo. By using fungal mutants and purified proteins we demonstrate that hydrophobin RodA, a surface protein making conidia immunologically inert, led to reduced NET formation of neutrophils encountering Aspergillus fungal elements. NET-dependent killing of Aspergillus-hyphae could be demonstrated at later time-points, but was only moderate. Thus, these data establish that NET formation occurs in vivo during host defence against A. fumigatus, but suggest

  15. A New Method To Monitor Airborne Inoculum of the Fungal Plant Pathogens Mycosphaerella brassicicola and Botrytis cinerea

    PubMed Central

    Kennedy, R.; Wakeham, A. J.; Byrne, K. G.; Meyer, U. M.; Dewey, F. M.

    2000-01-01

    We describe a new microtiter immunospore trapping device (MTIST device) that uses a suction system to directly trap air particulates by impaction in microtiter wells. This device can be used for rapid detection and immunoquantification of ascospores of Mycosphaerella brassicicola and conidia of Botrytis cinerea by an enzyme-linked immunosorbent assay (ELISA) under controlled environmental conditions. For ascospores of M. brassicicola correlation coefficients (r2) of 0.943 and 0.9514 were observed for the number of MTIST device-impacted ascospores per microtiter well and the absorbance values determined by ELISA, respectively. These values were not affected when a mixed fungal spore population was used. There was a relationship between the number of MTIST device-trapped ascospores of M. brassicicola per liter of air sampled and the amount of disease expressed on exposed plants of Brassica oleracea (Brussels sprouts). Similarly, when the MTIST device was used to trap conidia of B. cinerea, a correlation coefficient of 0.8797 was obtained for the absorbance values generated by the ELISA and the observed number of conidia per microtiter well. The relative collection efficiency of the MTIST device in controlled plant growth chambers with limited airflow was 1.7 times greater than the relative collection efficiency of a Burkard 7-day volumetric spore trap for collection of M. brassicicola ascospores. The MTIST device can be used to rapidly differentiate, determine, and accurately quantify target organisms in a microflora. The MTIST device is a portable, robust, inexpensive system that can be used to perform multiple tests in a single sampling period, and it should be useful for monitoring airborne particulates and microorganisms in a range of environments. PMID:10877797

  16. Persistence and Viability of Lecanicillium lecanii in Chinese Agricultural Soil

    PubMed Central

    Peng, De-Liang; Zhou, Jie; Zhang, Xiao-Lin; Zhang, Zhao-Rong; Zhao, Jin-Jin; Wu, Yu-Huan

    2015-01-01

    The entomopathogenic fungus L. lecanii has been developed as biopesticides and used widely for biological control of several insects in agricultural practice. Due to the lack of isolation/count methods for L. lecanii in soil, the persistence of this fungus in soil appears to have attracted no attention. A selective medium and count method for L. lecanii in soil based on cetyl trimethyl ammonium bromide (CTAB) was developed, and then the persistence and viability of this fungus in soil were investigated under field conditions between 2012 and 2014. The results showed that the rate of recovery for L. lecanii in soil on the selective CTAB medium was satisfactory. The minimum CFUs for L. lecanii on the selective medium (0.5 g/L CTAB) was about 102 conidia/g soil. The L. lecanii density in soil declined quickly in the first month after inoculation with fungal conidia, kept stable for 6 to 10 months, and then decreased gradually until undetectable. L. lecanii could persist for at least 14 months in the agricultural soil of northern China. The colony growth, conidia yield and germination rate on plates, as well as the median lethal concentration or times (LC50 or LT50) to aphids, mycelium growth in aphids and sporulation on aphids of L. lecanii did not change significantly during the persistence in soil. In general, the count method developed here was a very useful tool for monitoring the dynamics of natural or introduced L. lecanii populations in soil, and the data on the persistence of L. lecanii in soil reported here were helpful for biological control and environmental risk assessment. PMID:26375030

  17. Transcriptome Profiles of Human Lung Epithelial Cells A549 Interacting with Aspergillus fumigatus by RNA-Seq

    PubMed Central

    Jia, Xiaodong; Wang, Shuo; Wang, Jing; Chen, Yong; Zhao, Jingya; Tian, Shuguang; Han, Xuelin; Han, Li

    2015-01-01

    Lung epithelial cells constitute the first defense line of host against the inhaled Aspergillus fumigatus; however, the transcriptional response of human alveolar type II epithelial cells was still unclear. Here we used RNA-Seq technology to assess the transcriptome profiles of A549 cells following direct interaction with conidia of A. fumigatus. The total number of identified genes was 19118. Compared with uninfected A549 cells, 459 genes were differentially expressed in cells co-incubated with conidia for 8 h, including 302 up-regulated genes and 157 down-regulated genes. GO and KEGG pathway enrichment analysis showed that most of the up-regulated genes were related to immune response, chemotaxis and inflammatory response and enriched in cytokine-cytokine receptor interaction, JAK-STAT and MAPK signaling pathways. The down-regulated genes were mainly enriched for terms associated with development, hemopoiesis and ion transport. Among them, EGR4 and HIST1H4J gene had the maximum of fold change in up-regulated and down-regulated genes, respectively. Fourteen up-regulated genes and three down-regulated genes were further validated and significant increase on expression of IL-6, IL-8 and TNF-α in A549 cells were confirmed by qRT-PCR during the interaction of A549 cells with A. fumigatus. Besides, western blot showed that expression of two proteins (ARC, EGR1) significantly increased in A549 cells during interaction with A. fumigatus conidia for 8h. Interference of endogenous expression of ARC or EGR1 protein in A549 cells reduced the internalization of A. fumigatus. These results provided important insights into dynamic changes of gene expression in lung epithelial cells, especially its strong immunological response against A. fumigatus infection. PMID:26273834

  18. Detection of Erysiphe necator in Air Samples Using the Polymerase Chain Reaction and Species-Specific Primers.

    PubMed

    Falacy, Jennifer S; Grove, Gary G; Mahaffee, Walter F; Galloway, Heather; Glawe, Dean A; Larsen, Richard C; Vandemark, George J

    2007-10-01

    ABSTRACT A polymerase chain reaction (PCR) assay employing species-specific primers was developed to differentiate Erysiphe necator from other powdery mildews common in the northwest United States. DNA was extracted from mycelia, conidia, and/or chasmothecia that were collected from grape leaves with a Burkard cyclonic surface sampler. To differentiate E. necator from other erysiphaeceous fungi, primer pairs Uncin144 and Uncin511 were developed to select unique sequences of the internal transcribed spacer regions of E. necator. Using these primers in PCR amplifications, a 367-bp amplicon specific to E. necator was generated, but no amplicons were generated from other erysiphaceous species collected from 48 disparate hosts representing 26 vascular plant families. The PCR limit of detection was one to five conidia of E. necator placed directly into reaction mixtures or 100 to 250 conidia placed on glass rods coated with silicon grease. During field studies, this PCR assay facilitated the detection of E. necator inoculum in air samples within hours of sample rod collection and prior to disease onset. Amplification of E. necator DNA did not occur when the PCR assay was conducted on vineyard air samples collected while grapes were dormant or during periods when vine growth occurred but E. necator remained dormant. The initial PCR detection of E. necator of the season occurred during seasonal ascospore releases caused by precipitation events between bud burst and the prebloom period during the 3 years of the study. Detection ceased for 7 to 11 days following ascospore release and then resumed several days prior to the observance of microscopic symptoms and signs of powdery mildew in the field. Results of this study represent the initial step toward the goal of incorporating an inoculum availability component into current and future grapevine powdery mildew risk assessment models.

  19. Aspergillus nidulans transcription factor AtfA interacts with the MAPK SakA to regulate general stress responses, development and spore functions.

    PubMed

    Lara-Rojas, Fernando; Sánchez, Olivia; Kawasaki, Laura; Aguirre, Jesús

    2011-04-01

    Fungi utilize a phosphorelay system coupled to a MAP kinase module for sensing and processing environmental signals. In Aspergillus nidulans, response regulator SskA transmits osmotic and oxidative stress signals to the stress MAPK (SAPK) SakA. Using a genetic approach together with GFP tagging and molecular bifluorescence we show that SakA and ATF/CREB transcription factor AtfA define a general stress-signalling pathway that plays differential roles in oxidative stress responses during growth and development. AtfA is permanently localized in the nucleus, while SakA accumulates in the nucleus in response to oxidative or osmotic stress signals or during normal spore development, where it physically interacts with AtfA. AtfA is required for expression of several genes, the conidial accumulation of SakA and the viability of conidia. Furthermore, SakA is active (phosphorylated) in asexual spores, remaining phosphorylated in dormant conidia and becoming dephosphorylated during germination. SakA phosphorylation in spores depends on certain (SskA) but not other (SrrA and NikA) components of the phosphorelay system. Constitutive phosphorylation of SakA induced by the fungicide fludioxonil prevents both, germ tube formation and nuclear division. Similarly, Neurospora crassa SakA orthologue OS-2 is phosphorylated in intact conidia and gets dephosphorylated during germination. We propose that SakA-AtfA interaction regulates gene expression during stress and conidiophore development and that SAPK phosphorylation is a conserved mechanism to regulate transitions between non-growing (spore) and growing (mycelia) states.

  20. Laboratory evaluation of a native strain of Beauveria bassiana for controlling Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae).

    PubMed

    Immediato, Davide; Camarda, Antonio; Iatta, Roberta; Puttilli, Maria Rita; Ramos, Rafael Antonio Nascimento; Di Paola, Giancarlo; Giangaspero, Annunziata; Otranto, Domenico; Cafarchia, Claudia

    2015-09-15

    The poultry red mite, Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae) is one of the most economically important ectoparasites of laying hens worldwide. Chemical control of this mite may result in environmental and food contamination, as well as the development of drug resistance. High virulence of Beauveria bassiana sensu lato strains isolated from naturally infected hosts or from their environment has been demonstrated toward many arthropod species, including ticks. However, a limited number of studies have assessed the use of B. bassiana for the control of D. gallinae s.l. and none of them have employed native strains. This study reports the pathogenicity of a native strain of B. bassiana (CD1123) against nymphs and adults of D. gallinae. Batches of nymph and adult mites (i.e., n=720 for each stage) for treated groups (TGs) were placed on paper soaked with a 0.1% tween 80 suspension of B. bassiana (CIS, 10(5), 10(7) and 10(9) conidia/ml), whilst 240 untreated control mites for each stage (CG) were exposed only to 0.1% tween 80. The mites in TG showed a higher mortality at all stages (p<0.01) when compared to CG, depending on the time of exposure and the conidial concentration. A 100% mortality rate was recorded using a CIS of 10(9) conidia/ml 12 days post infection (DPI) in adults and 14 DPI in nymphs. B. bassiana suspension containing 10(9) conidia/ml was highly virulent towards nymph and adult stages of D. gallinae, therefore representing a possible promising natural product to be used in alternative or in combination to other acaricidal compounds currently used for controlling the red mite.

  1. Biological control of major postharvest pathogens on apple with Candida sake.

    PubMed

    Viñas, I; Usall, J; Teixidó, N; Sanchis, V

    1998-03-03

    Epiphytic microorganisms isolated from apples, pears and the surfaces of apple leaves were screened for antagonistic activity against Penicillium expansum (blue-mold), Botrytis cinerea (gray-mold) and Rhizopus nigricans (Rhizopus rot) on apple (Malus domestica). A total of 933 bacteria and yeasts were tested in primary screening against P. expansum. Ninety-two strains reduced the lesion size on apples by more than 50%, 72 of which were isolated from the surface of apples. For secondary screening against P. expansum, B. cinerea and R. nigricans, 31 strains were selected. The most promising isolate, CPA-1, was identified as Candida sake. This yeast, isolated from apples in storage season was very effective against all three diseases. Wounded Golden Delicious apples protected with the yeast suspension at a concentration of 2.6 x 10(6) CFU/ml and inoculated with conidia of B. cinerea and R. nigricans of 10(5) and 10(4) conidia/ml, respectively, did not develop rot. Complete control of P. expansum was obtained at the same concentration of the antagonist with a pathogen inoculum concentration of 10(3) conidia/ml. This strain, also provided excellent control of rot development under cold storage conditions. The strain of Candida sake can grow actively in aerobic conditions. In drop-inoculated wounds of apples, the populations of C. sake increased by more than 50-fold during the first 24 h at 20 degrees C. The maximum population of C. sake on apple wounds was the same at 20 as at 1 degrees C and was recovered after three and twenty days, respectively.

  2. Environmental Conditions Affect Botrytis cinerea Infection of Mature Grape Berries More Than the Strain or Transposon Genotype.

    PubMed

    Ciliberti, Nicola; Fermaud, Marc; Roudet, Jean; Rossi, Vittorio

    2015-08-01

    Effects of environment, Botrytis cinerea strain, and their interaction on the infection of mature grape berries were investigated. The combined effect of temperature (T) of 15, 20, 25, and 30°C and relative humidity (RH) of 65, 80, 90, and 100% was studied by inoculating berries with mycelium plugs. Regardless of the T, no disease occurred at 65% RH, and both disease incidence and severity increased with increasing RH. The combined effect of T (5 to 30°C) and wetness duration (WD) of 3, 6, 12, 24, and 36 h was studied by inoculating berries with conidia. At WD of 36 h, disease incidence was approximately 75% of affected berries at 20 or 25°C, 50% at 15°C, and 30 to 20% at 30 and 10°C; no infection occurred at 5°C. Under favorable conditions (100% RH or 36 h of WD) and unfavorable conditions (65% RH or 3 h of WD), berry wounding did not significantly affect disease incidence; under moderately favorable conditions (80% RH or 6 to 12 h of WD), disease incidence was approximately 1.5 to 5 times higher in wounded than in intact berries. Our data collectively showed that (i) T and RH or WD were more important than strain for mature berry infection by either mycelium or conidia and (ii) the effect of the environment on the different strains was similar. Two equations were developed describing the combined effect of T and RH, or T and WD, on disease incidence following inoculation by mycelium (R2=0.99) or conidia (R2=0.96), respectively. These equations may be useful in the development of models used to predict and control Botrytis bunch rot during berry ripening.

  3. Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease?

    NASA Astrophysics Data System (ADS)

    Moser, John C.; Konrad, Heino; Blomquist, Stacy R.; Kirisits, Thomas

    2010-02-01

    Dutch elm disease (DED) is a destructive vascular wilt disease of elm ( Ulmus) trees caused by the introduced Ascomycete fungus Ophiostoma novo-ulmi. In Europe, this DED pathogen is transmitted by elm bark beetles in the genus Scolytus. These insects carry phoretic mites to new, suitable habitats. The aim of this study was to record and quantify conidia and ascospores of O. novo-ulmi on phoretic mites on the three elm bark beetle species Scolytus multistriatus, Scolytus pygmaeus, and Scolytus scolytus. Spores of O. novo-ulmi were found on four of the ten mite species phoretic on Scolytus spp. These included Elattoma fraxini, Proctolaelaps scolyti, Pseudotarsonemoides eccoptogasteri, and Tarsonemus crassus. All four species had spores attached externally to their body surfaces. However, T. crassus carried most spores within its sporothecae, two paired pocket-like structures adapted for fungal transmission. Individuals of Pr. scolyti also had O. novo-ulmi conidia and ascospores frequently in their digestive system, where they may remain viable. While E. fraxini and P. eccoptogasteri rarely had spores attached to their bodies, large portions of Pr. scolyti and T. crassus carried significant numbers of conidia and/or ascospores of O. novo-ulmi. P. scolyti and T. crassus, which likely are fungivores, may thus contribute to the transmission of O. novo-ulmi, by increasing the spore loads of individual Scolytus beetles during their maturation feeding on twigs of healthy elm trees, enhancing the chance for successful infection with the pathogen. Only S. scolytus, which is the most efficient vector of O. novo-ulmi in Europe, carried high numbers of Pr. scolyti and T. crassus, in contrast to S. multistriatus and S. pygmaeus, which are known as less efficient vectors. The high efficiency of S. scolytus in spreading Dutch elm disease may be partly due to its association with these two mites and the hyperphoretic spores of O. novo-ulmi they carry.

  4. Potential of Entomopathogenic Fungi as Biological Control Agents of Diamondback Moth (Lepidoptera: Plutellidae) and Compatibility With Chemical Insecticides.

    PubMed

    Duarte, R T; Gonçalves, K C; Espinosa, D J L; Moreira, L F; De Bortoli, S A; Humber, R A; Polanczyk, R A

    2016-04-01

    The objectives were to evaluate the efficiency of entomopathogenic fungi against Plutella xylostella (L.) and the compatibility of the most virulent isolates with some of the insecticides registered for use on cabbage crops. Pathogenicity tests used isolates of Beauveria bassiana, Metarhizium rileyi, Isaria fumosorosea, Isaria sinclairii, and Lecanicillium muscarium standardized at a concentration of 10(7) conidia/ml. Cabbage leaf discs were immersed in these suspensions, and after evaporation of the excess water, were placed 10 second-instar larvae of P. xylostella, totaling 10 leaf discs per treatment. Mortality was assessed 7 d after treatment, and the isolates that caused mortality>80% were used to estimate LC50 and LT50. The compatibilities of the most virulent isolates and the insecticides were tested from the mixture of these into the culture medium, and after solidifying, the medium was inoculated with an aliquot of the isolated suspension. The following parameters were evaluated: growth of the colony, number and viability of conidia after 7 d. The isolated IBCB01, IBCB18, IBCB66, and IBCB87 of B. bassiana, LCMAP101 of M. rileyi, and ARSEF7973 of I. sinclairii caused mortality between 80 and 100%, with LC50 and LT50 between 2.504 to 6.775×10(4) conidia/ml and 52.22 to 112.13 h, respectively. The active ingredients thiamethoxam and azadirachtin were compatible with the entomopathogenic fungi. The results suggest that the use of these isolates is an important alternative in the pesticidal management of P. xylostella, with the possible exception of the associated use of chemical controls using the active ingredients thiamethoxam or azadirachtin.

  5. The fungistatic and fungicidal effects of volatiles from metathoracic glands of soybean-attacking stink bugs (Heteroptera: Pentatomidae) on the entomopathogen Beauveria bassiana.

    PubMed

    Lopes, Rogério B; Laumann, Raul A; Blassioli-Moraes, Maria C; Borges, Miguel; Faria, Marcos

    2015-11-01

    This study was initially designed to evaluate the differential susceptibility of three soybean-attacking pentatomids to the entomopathogenic fungus Beauveria bassiana in standardized bioassays. Euschistus heros (Eh) was shown to be significantly less susceptible than Chinavia ubica (Cu), whereas Dichelops melacanthus (Dm) adults were highly susceptible to fungal infections. A deeper look at the mechanisms involved in the possible role of volatiles from metathoracic glands on fungal infections was undertaken, and gland extracts from Nezara viridula (Nv), a species known for its resilience to fungal infections, were also included in the assays. Atmospheres with volatiles from pentatomids with very low-susceptibility to B. bassiana infections (Eh and Nv) had a significant effect on speed of germination as shown in counts performed up to 22h post-inoculation, by which time 0.1 (control), 0.6 (Dm), 17.9 (Cu), 32.6 (Eh), and 43.4% (Nv) of conidia had not germinated. The fungistatic (inhibitory) and fungicidal (lethal) effects of Eh and Nv volatile-rich atmospheres were subsequently quantified in Petri dishes with either PDA or PDA medium amended with carbendazim, which allowed germination rates to be determined at 18 and 48h post-inoculation, respectively. As opposed to control, Eh volatile-rich atmosphere had a clear fungistatic effect, since germination rate was only 27.4% within 18h, but reached 99.4% at 48h post-inoculation. For Nv volatile-rich atmospheres, only 15.1% of conidia germinated within 18h, and by 48h post-inoculation, approx. 18% of conidia were unviable (neither germ tubes nor intumescence), whereas in the control treatment rates were >99% at both reading times. Therefore, the gaseous phase of defensive secretions from fungus-resilient pentatomids possess a strong inhibitory effect and may display a less pronounced lethal effect on fungal germination, as was the case for Nv.

  6. The predatory capability of three nematophagous fungi in the control of Haemonchus contortus infective larvae in ovine faeces.

    PubMed

    Flores-Crespo, J; Herrera-Rodríguez, D; Mendoza de Gives, P; Liébano-Hernández, E; Vázquez-Prats, V M; López-Arellano, M E

    2003-12-01

    The effect of oral administration of three different nematode-trapping fungi, in aqueous suspension containing either Dactylaria sp. or Arthrobotrys oligospora conidia or Duddingtonia flagrans chlamydospores, on the number of Haemonchus contortus infective larvae in sheep faeces, was evaluated. The three selected species of fungi produce three-dimensional adhesive nets in the presence of nematodes. Sixteen Creole sheep were divided into four groups of four animals each. Groups 1 and 2 were orally drenched with a suspension containing 2x10(7) conidia of either A. oligospora or Dactylaria sp. Group 3, received a similar treatment, with D. flagrans chlamydospores, instead of conidia, being administered, at the same dose. Group 4 acted as control, without any fungi. Faecal samples were collected directly from the rectum of each sheep and faecal cultures were prepared and incubated at 15 and 21 days. Larvae were recovered from faecal cultures and counted. The highest reduction of the nematode population occurred in the D. flagrans group, reaching reductions of 96.3% and 91.4% in individual samplings in plates incubated for 15 and 21 days, respectively. Arthrobotrys oligospora showed moderate reductions in the faecal larval population, ranging between 25-64% at 15 days incubation. In general, Dactylaria sp., was less efficient in its trapping ability. Despite the inconsistent results with Dactylaria sp., reduction percentages of 73.4% and 80.7% were recorded in individual samplings during the first and second days, in plates incubated for 15 days. Duddingtonia flagrans, was shown to be a potential biological control agent of H. contortus infective larvae.

  7. Phacidiopycnis washingtonensis--a new species associated with pome fruits from Washington State.

    PubMed

    Xiao, C L; Rogers, J D; Kim, Y K; Liu, Q

    2005-01-01

    A new species of Phacidiopycnis associated with pome fruits is described. The fungus causes fruit rot on apples during storage and is associated with a twig dieback and canker disease of crabapple trees and dead twigs of pear trees. To characterize the biology of the fungus and compare it with Ph. piri, the type species of the genus, effects of nine media and light on mycelial growth and pycnidial production, mycelial growth in response to temperature and mode of conidial germination in response to nutrient were determined. Apple-juice agar, pear-juice agar, prune-juice agar, potato-dextrose agar (PDA) and malt-extract agar, Czapek-Dox agar and oatmeal agar (OMA) favored mycelial growth. Cornmeal agar (CMA) did not favor mycelial growth. Light effect on pycnidial formation was medium dependent. Abundant pycnidia with mature conidia formed in 14 d old PDA and OMA cultures at 20 C, regardless of light, whereas none or very few pycnidia formed on other media in the dark. Fluorescent light stimulated formation of pycnidia except on CMA. The fungus grew at -3-25 C, with optimum growth at 15-20 C. Conidia germinated either by forming germ tubes or less often by budding. Budding of conidia occurred in 1 and 10% pear-juice solutions but not in 100% pear-juice solution. Six isolates of Ph. washingtonensis from different species of pome fruits had identical ITS sequences. The sizes of the ITS region were the same for both Ph. washingtonensis and Ph. piri, and four polymorphic nucleotide sites were found in the ITS region between Ph. washingtonensis and Ph. piri. The similarity in ITS sequences between these two taxa is confirmatory evidence for the erection of the new species of Phacidiopycnis associated with pome fruits we describe here.

  8. Method To immobilize the aphid-pathogenic fungus erynia neoaphidis in an alginate matrix for biocontrol

    PubMed

    Shah; Aebi; Tuor

    1998-11-01

    Erynia neoaphidis is an important fungal pathogen of aphid pests worldwide. There have been few reported attempts to formulate this natural agent for use in biocontrol. In the current study, factors involved in the immobilization of E. neoaphidis hyphae in an alginate matrix were investigated. Hyphae of two isolates cultured in liquid medium were 220 to 620 &mgr;m in length and 7 to 19 &mgr;m in diameter with a 74 to 83% cytoplasmic content. The optimal concentration of low-viscosity sodium alginate for production of conidia from entrapped hyphae was 1.5% (wt/vol), and 0.1 and 0.25 M calcium chloride were equally suitable for use as the gelling solution. Alginate beads were rinsed with 10% sucrose after gelling. However, beads should not be left for longer than 40 min in 0.1 M calcium chloride or 10% sucrose to prevent a 10% loss in conidial production. A 40% (vol/vol) concentration of fungal biomass produced significantly more conidia than either 20% or the standard concentration of 10%. This effect persisted even after beads were dried overnight in a laminar flow hood and stored at 4 degreesC for 4 days. Conidia from freshly produced alginate beads caused 27 to 32% infection in Pea aphids as determined by standardized laboratory bioassays. This finding was not significantly different from infections in aphids inoculated with fresh mycelial mats or plugs from Petri dish cultures. In conclusion, algination appears to be a promising technique for utilizing E. neoaphidis in the biocontrol of aphid pests.

  9. Effect of salicylic acid on Fusarium graminearum, the major causal agent of fusarium head blight in wheat.

    PubMed

    Qi, Peng-Fei; Johnston, Anne; Balcerzak, Margaret; Rocheleau, Hélène; Harris, Linda J; Long, Xiang-Yu; Wei, Yu-Ming; Zheng, You-Liang; Ouellet, Thérèse

    2012-03-01

    Salicylic acid (SA) is one of the key signal molecules in regulating plant resistance to diverse pathogens. In Arabidopsis thaliana, it is predominantly associated with resistance against biotrophic and hemibiotrophic pathogens, and triggering systemic acquired resistance. In contrast, the effect of SA on the defence efficiency of wheat against fusarium head blight (FHB) and its causal agent, Fusarium graminearum, is still poorly understood. Here we show that the F. graminearum mycelial growth and conidia germination were significantly inhibited, and eventually halted in the presence of increasing concentration of SA in both liquid and solid media. Addition of SA also significantly reduced the production of the mycotoxin deoxynivalenol (DON). However the inhibitory effect of SA required acidic growth conditions to be observed while basic conditions allowed F. graminearum to use SA as a carbon source. High performance liquid chromatography (HPLC) analysis confirmed the capacity of F. graminearum to metabolize SA. To better understand the effect of SA on F. graminearum mycelial growth, we have compared the expression profiles of SA-treated and untreated F. graminearum liquid cultures after 8 and 24 h of treatment, using an F. graminearum custom-commercial microarray. The microarray analysis suggested that F. graminearum can metabolize SA through either the catechol or gentisate pathways that are present in some fungal species. Inoculation of F. graminearum conidia in a SA-containing solution has led to reduced FHB symptoms in the very susceptible Triticum aestivum cv. Roblin. In contrast, no inhibition was observed when SA and conidia were inoculated sequentially. The expression patterns for the wheat PR1, NPR1, Pdf1.2, and PR4 genes, a group of indicator genes for the defence response, suggested that SA-induced resistance contributed little to the reduction of symptoms in our assay conditions. Our results demonstrate that, although F. graminearum has the capacity to

  10. Histopathologic criteria to confirm white-nose syndrome in bats

    USGS Publications Warehouse

    Meteyer, C.U.; Buckles, E.L.; Blehert, D.S.; Hicks, A.C.; Green, D.E.; Shearn-Bochsler, V.; Thomas, N.J.; Gargas, A.; Behr, M.J.

    2009-01-01

    White-nose syndrome (WNS) is a cutaneous fungal disease of hibernating bats associated with a novel Geomyces sp. fungus. Currently, confirmation of WNS requires histopathologic examination. Invasion of living tissue distinguishes this fungal infection from those caused by conventional transmissible dermatophytes. Although fungal hyphae penetrate the connective tissue of glabrous skin and muzzle, there is typically no cellular inflammatory response in hibernating bats. Preferred tissue samples to diagnose this fungal infection are rostral muzzle with nose and wing membrane fixed in 10% neutral buffered formalin. To optimize detection, the muzzle is trimmed longitudinally, the wing membrane is rolled, and multiple cross-sections are embedded to increase the surface area examined. Periodic acid-Schiff stain is essential to discriminate the nonpigmented fungal hyphae and conidia. Fungal hyphae form cup-like epidermal erosions and ulcers in the wing membrane and pinna with involvement of underlying connective tissue. In addition, fungal hyphae are present in hair follicles and in sebaceous and apocrine glands of the muzzle with invasion of tissue surrounding adnexa. Fungal hyphae in tissues are branching and septate, but the diameter and shape of the hyphae may vary from parallel walls measuring 2 ??m in diameter to irregular walls measuring 3-5 ??m in diameter. When present on short aerial hyphae, curved conidia are approximately 2.5 ??m wide and 7.5 ??m in curved length. Conidia have a more deeply basophilic center, and one or both ends are usually blunt. Although WNS is a disease of hibernating bats, severe wing damage due to fungal hyphae may be seen in bats that have recently emerged from hibernation. These recently emerged bats also have a robust suppurative inflammatory response.

  11. Synergistic antifungal activity of sodium hypochlorite, hydrogen peroxide, and cupric sulfate against Penicillium digitatum.

    PubMed

    Cerioni, Luciana; Rapisarda, Viviana Andrea; Hilal, Mirna; Prado, Fernando Eduardo; Rodríguez-Montelongo, Luisa

    2009-08-01

    Oxidizing compounds such as sodium hypochlorite (NaCIO) and hydrogen peroxide (H2O2) are widely used in food sanitization because of their antimicrobial effects. We applied these compounds and metals to analyze their antifungal activity against Penicillium digitatum, the causal agent of citrus green mold. The MICs were 300 ppm for NaClO and 300 mM for H2O2 when these compounds were individually applied for 2 min to conidia suspensions. To minimize the concentration of these compounds, we developed and standardized a sequential treatment for conidia that resulted in loss of viability on growth plates and loss of infectivity on lemons. The in vitro treatment consists of preincubation with 10 ppm of NaClO followed by incubation with 100 mM H2O2 and 6 mM CuSO4 (cupric sulfate). The combination of NaClO and H2O2 in the presence of CuSO4 produces a synergistic effect (fractional inhibitory concentration index of 0.36). The sequential treatment applied in situ on lemon peel 24 h after the fruit was inoculated with conidia produced a significant delay in the fungal infection. The in vitro treatment was effective on both imazalil-sensitive and imazalil-resistant strains of P. digitatum and Geotrichum candidum, the causal agent of citrus sour rot. However, this treatment inhibited 90% of mycelial growth for Penicillium italicum (citrus blue mold). These results indicate that sequential treatment may be useful for postharvest control of citrus fruit diseases.

  12. Dosage Response Mortality of Japanese Beetle, Masked Chafer, and June Beetle (Coleoptera: Scarabaeidae) Adults When Exposed to Experimental and Commercially Available Granules Containing Metarhizium brunneum.

    PubMed

    Behle, Robert W; Goett, Erica J

    2016-05-01

    Field-collected adults of three genera of turf-infesting scarabs, Japanese beetle (Popillia japonica Newman), June beetles (Phyllophaga spp.), and masked chafers (Cyclocephala spp.), were exposed to experimental and commercial granule formulations of the entomopathogenic fungus Metarhizium brunneum (Petch) strain F52 to determine their relative susceptibility. Experimental granules contained microsclerotia produced by liquid fermentation with the ability to produce fresh conidia when rehydrated and commercial granules were Met 52 granular bioinsecticide. All three groups of scarab adults showed a positive dosage response to the fungus when exposed in cups of potting mix treated with the granules. LC50 values for microsclerotia granules were 1.9 × 10(7), 7.1 × 10(6), and 3.2 × 10(6) conidia cup(-1) for P. japonica, Phyllophaga spp., and Cyclocephala spp., respectively. LC50 values for Met 52 granules were 5.9 × 10(7), 5.1 × 10(7), and 7.6 × 10(6) conidia cup(-1), respectively. The experimental granules containing microsclerotia show promise as a viable commercial control agent. They can be produced using lower cost fermentation methods and applied at lower dosages (97 g for 100 m(2) as opposed to 489 g per 100 m(2) for Met 52). If M. brunneum is applied to control the aforementioned white grubs, our data indicate the potential for the adult beetles to also be infected as they enter the soil to lay eggs.

  13. Ras GTPase-Activating Protein Regulation of Actin Cytoskeleton and Hyphal Polarity in Aspergillus nidulans▿ †

    PubMed Central

    Harispe, Laura; Portela, Cecilia; Scazzocchio, Claudio; Peñalva, Miguel A.; Gorfinkiel, Lisette

    2008-01-01

    Aspergillus nidulans gapA1, a mutation leading to compact, fluffy colonies and delayed polarity establishment, maps to a gene encoding a Ras GTPase-activating protein. Domain organization and phylogenetic analyses strongly indicate that GapA regulates one or more “true” Ras proteins. A gapAΔ strain is viable. gapA colonies are more compact than gapA1 colonies and show reduced conidiation. gapAΔ strains have abnormal conidiophores, characterized by the absence of one of the two layers of sterigmata seen in the wild type. gapA transcript levels are very low in conidia but increase during germination and reach their maximum at a time coincident with germ tube emergence. Elevated levels persist in hyphae. In germinating conidiospores, gapAΔ disrupts the normal coupling of isotropic growth, polarity establishment, and mitosis, resulting in a highly heterogeneous cell population, including malformed germlings and a class of giant cells with no germ tubes and a multitude of nuclei. Unlike wild-type conidia, gapAΔ conidia germinate without a carbon source. Giant multinucleated spores and carbon source-independent germination have been reported in strains carrying a rasA dominant active allele, indicating that GapA downregulates RasA. gapAΔ cells show a polarity maintenance defect characterized by apical swelling and subapical branching. The strongly polarized wild-type F-actin distribution is lost in gapAΔ cells. As GapA-green fluorescent protein shows cortical localization with strong predominance at the hyphal tips, we propose that GapA-mediated downregulation of Ras signaling at the plasma membrane of these tips is involved in the polarization of the actin cytoskeleton that is required for hyphal growth and, possibly, for asexual morphogenesis. PMID:18039943

  14. Coordinated and independent functions of velvet-complex genes in fungal development and virulence of the fungal cereal pathogen Cochliobolus sativus.

    PubMed

    Wang, Rui; Leng, Yueqiang; Shrestha, Subidhya; Zhong, Shaobin

    2016-08-01

    LaeA and velvet proteins regulate fungal development and secondary metabolism through formation of multimeric complexes in many fungal species, but their functions in the cereal fungal pathogen Cochliobolus sativus are not well understood. In this study, four velvet complex genes (CsLaeA, CsVeA, CsVelB, and CsVelC) in C. sativus were identified and characterized using knockout mutants generated for each of the genes. Both ΔCsVeA and ΔCsVelB showed significant reduction in aerial mycelia growth. ΔCsVelB also exhibited a hypermorphic conidiation phenotype with indeterminate growth of the conidial tip cells and premature germination of conidia. ΔCsLaeA, ΔCsVeA, and ΔCsVelB produced more conidia under constant dark conditions than under constant light conditions whereas no differences were observed under the two conditions for the wild type. These three mutants also showed significantly reduced conidiation under constant light conditions, but produced more small sized conidia under constant dark conditions compared to the wild type. All knockout mutants (ΔCsLaeA, ΔCsVeA, ΔCsVelB and ΔCsVelC) showed some extent of reduction in virulence on susceptible barley plants compared to the wild type strain. The results revealed the conserved and unique roles of velvet-complex proteins as regulators in mediating fungal development and secondary metabolism in C. sativus.

  15. Monitoring of fungal loads in seabird rehabilitation centers with comparisons to natural seabird environments in northern California.

    PubMed

    Burco, Julia D; Massey, J Gregory; Byrne, Barbara A; Tell, Lisa; Clemons, Karl V; Ziccardi, Michael H

    2014-03-01

    Aspergillosis remains a major cause of mortality in captive and rehabilitated seabirds. To date, there has been poor documentation of fungal (particularly Aspergillus spp.) burdens in natural seabird loafing and roosting sites compared with fungal numbers in rehabilitation or captive settings and the various microenvironments that seabirds are exposed to during the rehabilitation process. This study compares fungal, particularly Aspergillus spp., burdens potentially encountered by seabirds in natural and rehabilitation environments. Differences among the various microenvironments in the rehabilitation facility were evaluated to determine the risk of infection when seabirds are experiencing high stress and poor immune function. Aspergillus spp. counts were quantified in three wildlife rehabilitation centers and five natural seabird loafing and roosting sites in northern California using a handheld impact air sampler and a water filtration system. Wildlife rehabilitation centers demonstrated an increase in numbers of conidia of Aspergillus spp. and Aspergillus fumigatus in air and water samples from select aquatic bird rehabilitation centers compared with natural seabird environments in northern California. Various microenvironments in the rehabilitation facility were identified as having higher numbers of conidia of Aspergillus spp. These results suggest that periodic monitoring of multiple local areas, where the birds spend time in a rehabilitation facility, should be done to identify "high risk" sites, where birds should spend minimal time, or sites that should be cleaned more frequently or have improved air flow to reduce exposure to fungal conidia. Overall, these results suggest that seabirds may be more likely to encounter Aspergillus spp. in various microenvironments in captivity, compared with their native habitats, which could increase their risk of developing disease when in a debilitated state.

  16. Fungicidal activities of commonly used disinfectants and antifungal pharmaceutical spray preparations against clinical strains of Aspergillus and Candida species.

    PubMed

    Gupta, A K; Ahmad, I; Summerbell, R C

    2002-04-01

    The antifungal efficacy of commercial chemical disinfectants and pharmaceutical antifungal agents against medically important moulds and yeast species was investigated. Chlorine, phenol, sodium dodecyl sulfate and quaternary ammonium salts were the chemical disinfectants, and bifonazole and terbinafine were the antifungal pharmaceutical products tested against clinical isolates of Aspergillus and Candida species. Fungal inocula were obtained from conidial preparations of two A. ochraceus strains and yeast cells of C. albicans, C. krusei and C. parapsilosis. The antifungal activities were evaluated either by determining the kill rate in a cell suspension media at different contact periods, or by examining the viability and growth on plates sprayed with the active ingredient. Chlorine (1%) was the only disinfectant with the ability to cause a rapid inactivation of all five strains. Phenol (5%) was equally effective against Candida species; however, a number of A. ochraceus conidia were able to survive this treatment for up to 1 h. Benzalkonium chloride (0.5%) and cetrimide (0.5%) were also able to disinfect the three Candida species rapidly; however, these two quaternary ammonium compounds were relatively ineffective against A. ochraceus. In spray experiments, quaternary ammonium compounds had a fungicidal activity against Candida species and were fungistatic against A. ochraceus conidia. All five fungal strains were able to resist 0.5% sodium dodecyl sulfate, present either in the suspension solution or on the sprayed plate. Of the two pharmaceutical antifungal products tested, bifonazole (1%) were essentially ineffective against all five strains. Terbinafine (1%) had a fungicidal activity against A. ochraceus and C. parapsilosis. In suspension experiments, an exposure to 0.01% terbinafine required a contact period of 1 h for a complete inactivation of A. ochraceus conidia and an onset of fungicidal effect on C. parapsilosis yeast cells. Terbinafine was only

  17. Production of extracellular traps against Aspergillus fumigatus in vitro and in infected lung tissue is dependent on invading neutrophils and influenced by hydrophobin RodA.

    PubMed

    Bruns, Sandra; Kniemeyer, Olaf; Hasenberg, Mike; Aimanianda, Vishukumar; Nietzsche, Sandor; Thywissen, Andreas; Jeron, Andreas; Latgé, Jean-Paul; Brakhage, Axel A; Gunzer, Matthias

    2010-04-29

    Aspergillus fumigatus is the most important airborne fungal pathogen causing life-threatening infections in immunocompromised patients. Macrophages and neutrophils are known to kill conidia, whereas hyphae are killed mainly by neutrophils. Since hyphae are too large to be engulfed, neutrophils possess an array of extracellular killing mechanisms including the formation of neutrophil extracellular traps (NETs) consisting of nuclear DNA decorated with fungicidal proteins. However, until now NET formation in response to A. fumigatus has only been demonstrated in vitro, the importance of neutrophils for their production in vivo is unclear and the molecular mechanisms of the fungus to defend against NET formation are unknown. Here, we show that human neutrophils produce NETs in vitro when encountering A. fumigatus. In time-lapse movies NET production was a highly dynamic process which, however, was only exhibited by a sub-population of cells. NETosis was maximal against hyphae, but reduced against resting and swollen conidia. In a newly developed mouse model we could then demonstrate the existence and measure the kinetics of NET formation in vivo by 2-photon microscopy of Aspergillus-infected lungs. We also observed the enormous dynamics of neutrophils within the lung and their ability to interact with and phagocytose fungal elements in situ. Furthermore, systemic neutrophil depletion in mice almost completely inhibited NET formation in lungs, thus directly linking the immigration of neutrophils with NET formation in vivo. By using fungal mutants and purified proteins we demonstrate that hydrophobin RodA, a surface protein making conidia immunologically inert, led to reduced NET formation of neutrophils encountering Aspergillus fungal elements. NET-dependent killing of Aspergillus-hyphae could be demonstrated at later time-points, but was only moderate. Thus, these data establish that NET formation occurs in vivo during host defence against A. fumigatus, but suggest

  18. Molecular taxonomy of bambusicolous fungi: Tetraplosphaeriaceae, a new pleosporalean family with Tetraploa-like anamorphs

    PubMed Central

    Tanaka, K.; Hirayama, K.; Yonezawa, H.; Hatakeyama, S.; Harada, Y.; Sano, T.; Shirouzu, T.; Hosoya, T.

    2009-01-01

    A new pleosporalean family Tetraplosphaeriaceae is established to accommodate five new genera; 1) Tetraplosphaeria with small ascomata and anamorphs belonging to Tetraploa s. str., 2) Triplosphaeria characterised by hemispherical ascomata with rim-like side walls and anamorphs similar to Tetraploa but with three conidial setose appendages, 3) Polyplosphaeria with large ascomata surrounded by brown hyphae and anamorphs producing globose conidia with several setose appendages, 4) Pseudotetraploa, an anamorphic genus, having obpyriform conidia with pseudosepta and four to eight setose appendages, and 5) Quadricrura, an anamorphic genus, having globose conidia with one or two long setose appendages at the apex and four to five short setose appendages at the base. Fifteen new taxa in these genera mostly collected from bamboo are described and illustrated. They are linked by their Tetraploa s. l. anamorphs. To infer phylogenetic placement in the Pleosporales, analyses based on a combined dataset of small- and large-subunit nuclear ribosomal DNA (SSU+LSU nrDNA) was carried out. Tetraplosphaeriaceae, however, is basal to the main pleosporalean clade and therefore its relationship with other existing families was not completely resolved. To evaluate the validity of each taxon and to clarify the phylogenetic relationships within this family, further analyses using sequences from ITS-5.8S nrDNA (ITS), transcription elongation factor 1-α (TEF), and β-tubulin (BT), were also conducted. Monophyly of the family and that of each genus were strongly supported by analyses based on a combined dataset of the three regions (ITS+TEF+BT). Our results also suggest that Tetraplosphaeria (anamorph: Tetraploa s. str.) is an ancestral lineage within this family. Taxonomic placement of the bambusicolous fungi in Astrosphaeriella, Kalmusia, Katumotoa, Massarina, Ophiosphaerella, Phaeosphaeria, Roussoella, Roussoellopsis, and Versicolorisporium, are also discussed based on the SSU

  19. Selection of indigenous isolates of entomopathogenic soil fungus Metarhizium anisopliae under laboratory conditions.

    PubMed

    Skalický, Aleš; Bohatá, Andrea; Šimková, Jana; Osborne, Lance S; Landa, Zdeněk

    2014-07-01

    Eight native isolates of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin were obtained by monitoring soils cultivated in a conventional manner. These isolates were compared in three areas: (a) conidial germination, (b) radial growth and sporulation and (c) ability of conidia to infect Tenebrio molitor larvae. All bioassays were carried out at constant temperatures of 10, 15, and 20 °C. Conidia of individual isolates demonstrated differences in germination after a 24-h long incubation at all evaluated temperatures. At 20 °C, the germination ranged from 67 to 100 % and at 15 °C from 5.33 to 46.67 %. At 10 °C, no germination was observed after 24 h; nevertheless, it was 8.67-44.67 % after 48 h. In terms of radial growth, the culture diameters and the associated production of spores of all isolates increased with increasing temperature. At 10 °C, sporulation was observed in three isolates while all remaining cultures appeared sterile. Three weeks post-inoculation, conidia of all assessed isolates caused 100 % cumulative mortality of treated larvae of T. molitor at 15 and 20 °C with the exception of isolate 110108 that induced 81.33 % mortality at 15 °C. At 10 °C, larval cumulative mortality ranged from 6.67 to 85.33 % depending on the isolate. Isolates 110108 and 110111 showed significantly slower outset and a much lower rate of infection at all temperatures compared to other tested isolates of M. anisopliae. The bioassays were carried out with the purpose to sort and select indigenous isolates of M. anisopliae useful as biocontrol agents in their original habitat.

  20. Sexual Reproduction in Aspergillus flavus Sclerotia: Acquisition of Novel Alleles from Soil Populations and Uniparental Mitochondrial Inheritance.

    PubMed

    Horn, Bruce W; Gell, Richard M; Singh, Rakhi; Sorensen, Ronald B; Carbone, Ignazio

    2016-01-01

    Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. flavus is heterothallic and laboratory crosses between strains of the opposite mating type produce progeny showing genetic recombination. Sclerotia formed in crops are dispersed onto the soil surface at harvest and are predominantly produced by single strains of one mating type. Less commonly, sclerotia may be fertilized during co-infection of crops with sexually compatible strains. In this study, laboratory and field experiments were performed to examine sexual reproduction in single-strain and fertilized sclerotia following exposure of sclerotia to natural fungal populations in soil. Female and male roles and mitochondrial inheritance in A. flavus were also examined through reciprocal crosses between sclerotia and conidia. Single-strain sclerotia produced ascospores on soil and progeny showed biparental inheritance that included novel alleles originating from fertilization by native soil strains. Sclerotia fertilized in the laboratory and applied to soil before ascocarp formation also produced ascospores with evidence of recombination in progeny, but only known parental alleles were detected. In reciprocal crosses, sclerotia and conidia from both strains functioned as female and male, respectively, indicating A. flavus is hermaphroditic, although the degree of fertility depended upon the parental sources of sclerotia and conidia. All progeny showed maternal inheritance of mitochondria from the sclerotia. Compared to A. flavus populations in crops, soil populations would provide a higher likelihood of exposure of sclerotia to sexually compatible strains and a more diverse source of genetic material for outcrossing.

  1. Metabolic and developmental effects resulting from deletion of the citA gene encoding citrate synthase in Aspergillus nidulans.

    PubMed

    Murray, Sandra L; Hynes, Michael J

    2010-04-01

    Citrate synthase is a central activity in carbon metabolism. It is required for the tricarboxylic acid (TCA) cycle, respiration, and the glyoxylate cycle. In Saccharomyces cerevisiae and Arabidopsis thaliana, there are mitochondrial and peroxisomal isoforms encoded by separate genes, while in Aspergillus nidulans, a single gene, citA, encodes a protein with predicted mitochondrial and peroxisomal targeting sequences (PTS). Deletion of citA results in poor growth on glucose but not on derepressing carbon sources, including those requiring the glyoxylate cycle. Growth on glucose is restored by a mutation in the creA carbon catabolite repressor gene. Methylcitrate synthase, required for propionyl-coenzyme A (CoA) metabolism, has previously been shown to have citrate synthase activity. We have been unable to construct the mcsADelta citADelta double mutant, and the expression of mcsA is subject to CreA-mediated carbon repression. Therefore, McsA can substitute for the loss of CitA activity. Deletion of citA does not affect conidiation or sexual development but results in delayed conidial germination as well as a complete loss of ascospores in fruiting bodies, which can be attributed to loss of meiosis. These defects are suppressed by the creA204 mutation, indicating that McsA activity can substitute for the loss of CitA. A mutation of the putative PTS1-encoding sequence in citA had no effect on carbon source utilization or development but did result in slower colony extension arising from single conidia or ascospores. CitA-green fluorescent protein (GFP) studies showed mitochondrial localization in conidia, ascospores, and hyphae. Peroxisomal localization was not detected. However, a very low and variable detection of punctate GFP fluorescence was sometimes observed in conidia germinated for 5 h when the mitochondrial targeting sequence was deleted.

  2. Biocontrol of Monilinia laxa by Aureobasidium pullulans strains: Insights on competition for nutrients and space.

    PubMed

    Di Francesco, Alessandra; Ugolini, Luisa; D'Aquino, Salvatore; Pagnotta, Eleonora; Mari, Marta

    2017-02-17

    Two Aureobasidium pullulans strains (L1 and L8), able to prevent postharvest fruit decay, were evaluated in order to elucidate how the competition for nutrients and space was involved in their activity against Monilinia laxa, the causal agent of peach brown rot. The competition for nutrients was studied by co-culturing pathogen conidia and antagonists in different conditions of nutrient availability and avoiding contact between them. Both antagonists prevented the germination of conidia of M. laxa in water, reducing germination rate by >35%. However, L1 and L8 showed the lowest inhibition of conidial germination in peach juice at 5%, with a reduction of 12.6% and 13.9% respectively. HPLC amino acid analysis of peach juice revealed that the addition of the yeast suspension greatly modified their composition: asparagine was completely depleted soon after 12h of incubation and was probably hydrolyzed to aspartic acid by the yeasts, as aspartic acid content markedly increased. Pure asparagine and aspartic acid were tested by in vitro trials at the concentrations found in peach juice: both influenced M. laxa growth, but in opposite ways. Asparagine stimulated pathogen growth; conversely, amended medium with aspartic acid significantly inhibited the conidia germination and mycelial development of M. laxa. Scanning Electron Microscopy revealed that both strains showed a great capability to compete with M. laxa for space (starting 8h after treatment), colonizing the wound surface and inhibiting pathogen growth. This study clearly showed that A. pullulans L1 and L8 strains could compete with M. laxa for nutrients and space; this mode of action may play an important role in the antagonistic activity, especially in the first hours of tritrophic host-pathogen-antagonist interaction, although several other mechanisms can interact each other.

  3. Environmental contamination by Aspergillus spp. in laying hen farms and associated health risks for farm workers.

    PubMed

    Cafarchia, Claudia; Camarda, Antonio; Iatta, Roberta; Danesi, Patrizia; Favuzzi, Vincenza; Di Paola, Giancarlo; Pugliese, Nicola; Caroli, Anna; Montagna, Maria Teresa; Otranto, Domenico

    2014-03-01

    Data on the occurrence and epidemiology of Aspergillus spp. in laying hens farms are scant. With the aims of determining levels of airborne contamination in laying hen farms and evaluating the potential risk of infection for workers and animals, 57 air samples from 19 sheds (Group I), 69 from faeces (Group II), 19 from poultry feedstuffs (Group III) and 60 from three anatomical sites (i.e. nostrils, pharynx, ears) of 20 farm workers (Group IV) were cultured. The Aspergillus spp. prevalence in samples ranged from 31.6% (Group III) to 55.5% (Group IV), whereas the highest conidia concentration was retrieved in Group II (1.2 × 10(4) c.f.u. g(-1)) and in Group III (1.9 × 10(3) c.f.u. g(-1)). The mean concentration of airborne Aspergillus spp. conidia was 70 c.f.u. m(-3) with Aspergillus fumigatus (27.3%) being the most frequently detected species, followed by Aspergillus flavus (6.3%). These Aspergillus spp. were also isolated from human nostrils (40%) and ears (35%) (P<0.05) (Group IV). No clinical aspergillosis was diagnosed in hens. The results demonstrate a relationship between the environmental contamination in hen farms and presence of Aspergillus spp. on animals and humans. Even if the concentration of airborne Aspergillus spp. conidia (i.e. 70 c.f.u. m(-3)) herein detected does not trigger clinical disease in hens, it causes human colonization. Correct management of hen farms is necessary to control environmental contamination by Aspergillus spp., and could lead to a significant reduction of animal and human colonization.

  4. Application of loop-mediated isothermal amplification assays for direct identification of pure cultures of Aspergillus flavus, A. nomius, and A. caelatus and for their rapid detection in shelled Brazil nuts.

    PubMed

    Luo, Jie; Taniwaki, Marta H; Iamanaka, Beatriz T; Vogel, Rudi F; Niessen, Ludwig

    2014-02-17

    Brazil nuts have a high nutritional content and are a very important trade commodity for some Latin American countries. Aflatoxins are carcinogenic fungal secondary metabolites. In Brazil nuts they are produced predominantly by Aspergillus (A.) nomius and A. flavus. In the present study we applied and evaluated two sets of primers previously published for the specific detection of the two species using loop-mediated isothermal amplification (LAMP) technology. Moreover, a primer set specific for A. caelatus as a frequently occurring non-aflatoxigenic member of Aspergillus section Flavi in Brazil nuts was newly developed. LAMP assays were combined with a simplified DNA release method and used for rapid identification of pure cultures and rapid detection of A. nomius and A. flavus from samples of shelled Brazil nuts. An analysis of pure cultures of 68 isolates representing the major Aspergillus species occurring on Brazil nuts showed that the three LAMP assays had individual accuracies of 61.5%, 84.4%, and 93.3% for A. flavus, A. nomius, and A. caelatus, respectively when morphological identification was used as a reference. The detection limits for conidia added directly to the individual LAMP reactions were found to be 10⁵ conidia per reaction with the primer set ID9 for A. nomius and 10⁴ conidia per reaction with the primer set ID58 for A. flavus. Sensitivity was increased to 10¹ and 10² conidia per reaction for A. nomius and A. flavus, respectively, when sample preparation included a spore disruption step. The results of LAMP assays obtained during the analysis of 32 Brazil nut samples from different regions of Brazil and from different steps in the production process of the commodity were compared with results obtained from mycological analysis and aflatoxin analysis of corresponding samples. Compared with mycological analysis of the samples, the Negative Predictive Values of LAMP assays were 42.1% and 12.5% while the Positive Predictive Values were 61

  5. Penicillium kongii, a new terverticillate species isolated from plant leaves in China.

    PubMed

    Wang, Bo; Wang, Long

    2013-01-01

    A new Penicillium species isolated from plant leaves, characterized by restricted growth, terverticillate penicilli, ovoid to ellipsoidal conidia and a red soluble pigment on yeast extract sucrose agar is reported here. Penicillium kongii sp. nov. belongs to subgenus Penicillium section Brevicompacta and is morphologically similar to P. bialowiezense and P. brevicompactum. Phylogenetic analyses based on sequence data from calmodulin gene, β-tubulin gene and rDNA ITS1-5.8S-ITS2 show that P. kongii forms a distinctive clade.

  6. Effects of temperature and relative humidity on sporulation of Metarhizium anisopliae var. acridum in mycosed cadavers of Schistocerca gregaria.

    PubMed

    Arthurs, S; Thomas, M B

    2001-08-01

    The effects of relative humidity (RH) and temperature on the sporulation of Metarhizium anisopliae var. acridum on mycosed cadavers of desert locust, Schistocerca gregaria, were assessed in the laboratory. Quantitative assessments of conidial production over 10 days under constant conditions showed that sporulation was optimized at RH > 96% and at temperatures between 20 and 30 degrees C. Under both these conditions >10(9) conidia/cadaver were produced. At 25 degrees C, conidial yield was maximized under conditions in which cadavers remained in contact with damp substrate. Relatively little sporulation occurred at 15 degrees C (< 3 x 10(7) conidia/cadaver) and 40 degrees C (< 4 x 10(6) conidia/cadaver) and no sporulation occurred at 10 or 45 degrees C. Following incubation, conidial yield was closely related to the water content of locust cadavers. In separate tests, locust cadavers were incubated for 10 days under diurnally fluctuating temperature and RH that comprised favorable (25 degrees C/100% RH) alternating with unfavorable (40 degrees C/80% RH) conditions for sporulation. In this case, fewer conidia were produced compared with cadavers that were incubated under the favorable conditions for an equal period cumulatively but were not periodically exposed to unfavorable conditions. However, this reduced sporulation observed with the fluctuating condition was not observed when cadavers were similarly incubated under favorable/unfavorable conditions of temperature but were not periodically exposed to the low RH condition. This result implies that sporulation is a dynamic process, dependent not only on periodic exposure to favorable RH but also on the interrelation of this with low RH. Associated tests and the monitoring of changes in cadaver weights imply that the mechanism driving the reduced sporulation under fluctuating RH is the net water balance of cadavers, i.e. the cumulative ability of the fungus/cadaver to adsorb water necessary for sporulation at high

  7. Four new species in Magnaporthaceae from grass roots in New Jersey Pine Barrens.

    PubMed

    Luo, Jing; Walsh, Emily; Zhang, Ning

    2014-01-01

    Based on morphology and DNA sequences of SSU, ITS, LSU, MCM7, RPB1 and TEF1 genes, we describe four new species in Magnaporthaceae that are associated with grass roots collected from New Jersey Pine Barrens. A new genus, Pseudophialophora, is erected to accommodate three species, which is characterized by slow growth on potato dextrose agar, curved conidiogenous cells without a conspicuous collarette at the apex and oblong ellipsoidal conidia. Pseudophialophora eragrostis, P. panicorum and P. schizachyrii are assigned to this genus. A new species of Magnaporthiopsis also is reported and named as M. panicorum. Distinctions between them and phylogenetic relationships with other Magnaporthaceae taxa are discussed.

  8. A rare case of human mycosis by Rhizoctonia solani.

    PubMed

    Kaore, N M; Atul, A R; Khan, M Z; Ramnani, V K

    2012-01-01

    Rhizoctonia solani is a most widely recognized strong saprophyte with a great diversity of host plants. It is a first ever case of extensive human mycosis caused by Rhizoctonia solani in a 65-year-old diabetic and hypertensive farmer, with a history of head injury caused by fall of mud wall. Necrotic material collected revealed septate fungal hyphae with bacterial co-infection. Fungal culture on SDA at 25°C showed cotton wooly growth progressing to greyish-white to shiny metallic black colonies and identified on basis of septate mycelial growth without conidia, right angle branching, presence of compact hyphal forms and anastomosis between branching hyphae on LPCB mount.

  9. In vitro colony interactions among species of trichoderma with inference toward biological control. Forest Service research paper

    SciTech Connect

    Reaves, J.L.; Crawford, R.H.

    1994-07-01

    Colony of interactions among 15 isolates representing seven species of Trichoderma were evaluated in vitro interactions characterized by zones of inhibition, demarcation lines, ridges of conidia, overgrowth, intermingling, anastomosis, and hyphal coiling in self-pairings and intraspecific and interspecific pairings of the seven species were recorded. Antagnostic interactions such as zones of inhibition were prevelent in these pairings. An understanding of the compatibility between species of isolates of Trichoderma will provide information on the use of multiple species of Trichoderma as biological control agents.

  10. Development in Aspergillus

    PubMed Central

    Krijgsheld, P.; Bleichrodt, R.; van Veluw, G.J.; Wang, F.; Müller, W.H.; Dijksterhuis, J.; Wösten, H.A.B.

    2013-01-01

    The genus Aspergillus represents a diverse group of fungi that are among the most abundant fungi in the world. Germination of a spore can lead to a vegetative mycelium that colonizes a substrate. The hyphae within the mycelium are highly heterogeneous with respect to gene expression, growth, and secretion. Aspergilli can reproduce both asexually and sexually. To this end, conidiophores and ascocarps are produced that form conidia and ascospores, respectively. This review describes the molecular mechanisms underlying growth and development of Aspergillus. PMID:23450714

  11. Biodeterioration of optical glass induced by lubricants used in optical instruments technology.

    PubMed

    Bartosik, Magdalena; Zakowska, Zofia; Cedzińska, Krystyna; Rozniakowski, Kazimierz

    2010-01-01

    The process of biodeterioration of optical glass was studied after being induced by an auxiliary material (lubricant 4CKP) used in the production of optical instruments. It was determined that the lubricant can initiate growth of conidia of Aspergillus niger fungus. Acid spawn metabolites cause deterioration of the glass surface. Measurements of laser light beam transmittance through the glass plate and the AAS chemical analysis method of the post-culture fluid allowed to determine that glass with a high SiO2 content is most resistant to corrosion caused by the growth of A. niger fungi spawn.

  12. Efficacy of Clonostachys rosea and Duddingtonia flagrans in Reducing the Haemonchus contortus Infective Larvae

    PubMed Central

    da Silva, Manoel Eduardo; Braga, Fabio Ribeiro; de Gives, Pedro Mendoza; Uriostegui, Miguel Angel Mercado; Reyes, Manuela; Soares, Filippe Elias de Freitas; de Carvalho, Lorendane Millena; Rodrigues, Francielle Bosi; de Araújo, Jackson Victor

    2015-01-01

    The biocontrol is proven effective in reducing in vitro and in situ free-living stages of major gastrointestinal helminths, allowing progress in reducing losses by parasitism, maximizing production, and productivity. This study aimed at evaluating the predatory activity of fungal isolates of Duddingtonia flagrans and Clonostachys rosea species and its association on infective larvae (L3) of H. contortus in microplots formed by grasses and maintained in a protected environment. All groups were added with 10 mL of an aqueous suspension with 618 H. contortus L3 approximately. Group 1 was used as control and only received the infective larvae. Groups 2 and 3 received D. flagrans chlamydospores and C. rosea conidia at doses of 5 × 106. Group 4 received the combination of 5 × 106 D. flagrans chlamydospores + 5 × 106 C. rosea conidia. D. flagrans and C. rosea showed nematicidal effectiveness reducing by 91.5 and 88.9%, respectively, the population of H. contortus L3. However, when used in combination efficiency decreased to 74.5% predation of H. contortus L3. These results demonstrate the need for further studies to determine the existence of additive effects, synergistic or antagonistic, between these species. PMID:26504809

  13. Antifungal curcumin promotes chitin accumulation associated with decreased virulence of Sporothrix schenckii.

    PubMed

    Huang, Lilin; Zhang, Jing; Song, Tianzhang; Yuan, Liyan; Zhou, Junjie; Yin, Hongling; He, Tailong; Gao, Wenchao; Sun, Yao; Hu, Xuchu; Huang, Huaiqiu

    2016-05-01

    Curcumin, a yellow polyphenol compound, is known to possess antifungal activity for a range of pathogenic fungi. However, the fungicidal mechanism of curcumin (CUR) has not been identified. We have occasionally found that chitin redistributes to the cell wall outer layer of Sporothrix schenckii (S. schenckii) upon sublethal CUR treatment. Whether CUR can affect chitin synthesis via the protein kinase C (PKC) signaling pathway has not been investigated. This study describes a direct fungicidal activity of CUR against S. schenckii demonstrated by the results of a checkerboard microdilution assay and, for the first time, a synergistic effect of CUR with terbinafine (TRB). Furthermore, the results of real-time PCR showed that sublethal CUR upregulated the transcription of PKC, chitin synthase1 (CHS1), and chitin synthase3 (CHS3) in S. schenckii. The fluorescence staining results using wheat germ agglutinin-fluorescein isothiocyanate (WGA-FITC) and calcofluor white (CFW) consistently showed that chitin exposure and total chitin content were increased on the conidial cell wall of S. schenckii by sublethal CUR treatment. A histopathological analysis of mice infected with CUR-treated conidia showed dampened inflammation in the local lesion and a reduced fungal burden. The ELISA results showed proinflammatory cytokine secretion at an early stage from macrophages stimulated by the CUR-treated conidia. The present data led to the conclusion that CUR is a potential antifungal agent and that its fungicidal mechanism may involve chitin accumulation on the cell wall of S. schenckii, which is associated with decreased virulence in infected mice.

  14. Hyphal tip extension in Aspergillus nidulans requires the manA gene, which encodes phosphomannose isomerase.

    PubMed Central

    Smith, D J; Payton, M A

    1994-01-01

    A strain of Aspergillus nidulans carrying a temperature-sensitive mutation in the manA gene produces cell walls depleted of D-mannose and forms hyphal tip balloons at the restrictive temperature (B.P. Valentine and B.W. Bainbridge, J. Gen. Microbiol. 109:155-168, 1978). We have isolated and characterized the manA gene and physically located it between 3.5 and 5.5 kb centromere distal of the riboB locus on chromosome VIII. The manA gene contains four introns and encodes a 50.6-kDa protein which has significant sequence identity to type I phosphomannose isomerase proteins from other eukaryotes. We have constructed by integrative transformation a null mutation in the manA gene which can only be maintained in a heterokaryotic strain with wild-type manA+ nuclei. Thus, a manA null mutation is lethal in A. nidulans. The phenotype of the mutation was analyzed in germinating conidia. Such conidia are able to commence germination but swell abnormally, sometimes producing a misshapen germ tube, before growth ceases. The reason for the lethality is probably the lack of synthesis of mannose-containing cell wall polymers that must be required for normal cell wall development in growing hyphae. Images PMID:8065336

  15. UVA Photoactivation of Harmol Enhances Its Antifungal Activity against the Phytopathogens Penicillium digitatum and Botrytis cinerea

    PubMed Central

    Olmedo, Gabriela M.; Cerioni, Luciana; González, María M.; Cabrerizo, Franco M.; Volentini, Sabrina I.; Rapisarda, Viviana A.

    2017-01-01

    Phytopathogenic fungi responsible for post-harvest diseases on fruit and vegetables cause important economic losses. We have previously reported that harmol (1-methyl-9H-pyrido[3,4-b]indol-7-ol) is active against the causal agents of green and gray molds Penicillium digitatum and Botrytis cinerea, respectively. Here, antifungal activity of harmol was characterized in terms of pH dependency and conidial targets; also photodynamic effects of UVA irradiation on the antimicrobial action were evaluated. Harmol was able to inhibit the growth of both post-harvest fungal disease agents only in acidic conditions (pH 5), when it was found in its protonated form. Conidia treated with harmol exhibited membrane integrity loss, cell wall disruption, and cytoplasm disorganization. All these deleterious effects were more evident for B. cinerea in comparison to P. digitatum. When conidial suspensions were irradiated with UVA in the presence of harmol, antimicrobial activity against both pathogens was enhanced, compared to non-irradiated conditions. B. cinerea exhibited a high intracellular production of reactive oxygen species (ROS) when was incubated with harmol in irradiated and non-irradiated treatments. P. digitatum showed a significant increase in ROS accumulation only when treated with photoexcited harmol. The present work contributes to unravel the antifungal activity of harmol and its photoexcited counterpart against phytopathogenic conidia, focusing on ROS accumulation which could account for damage on different cellular targets. PMID:28326067

  16. LongSAGE gene-expression profiling of Botrytis cinerea germination suppressed by resveratrol, the major grapevine phytoalexin.

    PubMed

    Zheng, Chuanlin; Choquer, Mathias; Zhang, Bing; Ge, Hui; Hu, Songnian; Ma, Huiqin; Chen, Shangwu

    2011-09-01

    The ascomycetes Botrytis cinerea is one of the most studied necrotrophic phytopathogens and one of the main fungal parasites of grapevine. As a defense mechanism, grapevine produces a phytoalexin compound, resveratrol, which inhibits germination of the fungal conidium before it can penetrate the plant barriers and lead to host cell necrotrophy. To elucidate the effect of resveratrol on transcriptional regulation in B. cinerea germlings, two LongSAGE (long serial analysis of gene expression) libraries were generated in vitro for gene-expression profiling: 41 428 tags and among them, 15 665 unitags were obtained from resveratrol-treated B. cinerea germlings and 41 358 tags, among them, 16 362 unitags were obtained from non-treated B. cinerea germlings. In-silico analysis showed that about half of these unitags match known genes in the complete B. cinerea genome sequence. Comparison of unitag frequencies between libraries highlighted 110 genes that were transcriptionally regulated in the presence of resveratrol: 53 and 57 genes were significantly down- and upregulated, respectively. Manual curation of their putative functional categories showed that primary metabolism of germinating conidia appears to be markedly affected under resveratrol treatment, along with changes in other putative metabolic pathways, such as resveratrol detoxification and virulence-effector secretion, in B. cinerea germlings. We propose a hypothetical model of cross talk between B. cinerea germinating conidia and resveratrol-producing grapevine at the very early steps of infection.

  17. cAMP-pKA signaling regulates multiple steps of fungal infection cooperatively with Cmk1 MAP kinase in Colletotrichum lagenarium.

    PubMed

    Yamauchi, Junko; Takayanagi, Naoyuki; Komeda, Kenichi; Takano, Yoshitaka; Okuno, Tetsuro

    2004-12-01

    In Colletotrichum lagenarium, RPK1 encoding the regulatory subunit of PKA is required for pathogenicity. From the rpkl mutant that forms small colonies, we isolated three growth-suppressor mutants. All rpk1-suppressor mutants are nonpathogenic and contain amino acid changes in the PKA catalytic subunit Cpkl. To assess the roles of cyclic AMP (cAMP) signaling in detail, we generated knockout mutants of CPK1 and the adenylate cyclase gene CAC1. The cpk1 and cac1 mutants are nonpathogenic on cucumber. Interestingly, both of the mutants germinated poorly, suggesting involvement of cAMP signaling in germination. Germination defect in the cpk1 and cac1 mutants is partially rescued by incubation of the conidia at lower concentrations. Germinating conidia of the cpk1 and cac1 mutants can form appressoria, but the appressoria formed by them are nonfunctional, like those of the rpk1 mutant. Cytological analysis indicates that the appressoria of the cpk1 mutant contain larger numbers of lipid bodies compared with the wild type, whereas lipid levels in the rpk1 mutants are lower, suggesting cAMP-mediated regulation of lipid metabolism for appressorium functionality. Furthermore, the cpk1 and cacl mutants have a defect in infectious growth in plant. In C. lagenarium, Cmkl mitogen-activated protein kinase (MAPK) regulates germination, appressorium formation, and infectious growth. These results suggest that cAMP signaling controls multiple steps of fungal infection in cooperative regulation with Cmkl MAPK in C. lagenarium.

  18. The Aspergillus nidulans cetA and calA genes are involved in conidial germination and cell wall morphogenesis.

    PubMed

    Belaish, Ravit; Sharon, Haim; Levdansky, Emma; Greenstein, Shulamit; Shadkchan, Yana; Osherov, Nir

    2008-03-01

    The Aspergillus nidulans genes cetA (AN3079.2) and calA (AN7619.2) encode a novel class of fungal thaumatin-like proteins of unknown function. Deletion of cetA does not result in an observable phenotype [Greenstein, S., Shadkchan, Y., Jadoun, J., Sharon, C., Markovich, S., Osherov, N., 2006. Analysis of the Aspergillus nidulans thaumatin-like cetA gene and evidence for transcriptional repression of pyr4 expression in the cetA-disrupted strain. Fungal Genet. Biol. 43, 42-53]. We prepared knockout calA and calA/cetA A. nidulans strains. The calA mutants were phenotypically identical to the wild-type. In contrast, the cetA/calA double mutant showed a synthetic lethal phenotype suggesting that the two genes affect a single function or pathway: most of its conidia were completely inhibited in germination. Many collapsed and underwent lysis. A few showed abnormal germination characterized by short swollen hyphae and abnormal hyphal branching. Nongerminated conidia contained a single condensed nucleus suggesting a block in early germination. This is the first functional analysis of the novel cetA/calA family of thaumatin-like genes and their role in A. nidulans conidial germination. We show that CETA and CALA are secreted proteins that together play an essential role in early conidial germination.

  19. Analysis of the Aspergillus nidulans thaumatin-like cetA gene and evidence for transcriptional repression of pyr4 expression in the cetA-disrupted strain.

    PubMed

    Greenstein, Shulamit; Shadkchan, Yona; Jadoun, Jeries; Sharon, Chaim; Markovich, Sarit; Osherov, Nir

    2006-01-01

    The asexual spore or conidium plays a critical role in the life cycle of many filamentous fungi. However, the process of conidial germination remains surprisingly obscure. To better understand this process at the molecular level we characterized the Aspergillus nidulans cetA gene which is uniquely transcribed in conidiating cultures and whose transcript is significantly enriched in mature conidia. CetA is a member of a novel family of fungal genes of unknown function with homology to plant thaumatin-like (PR-5) defense proteins. We demonstrate by Northern analysis that cetA is a glucose-repressible gene. Transcriptional repression is dependent on the presence of protein kinase A. Western analysis indicates that the CETA protein is absent from conidia but is highly expressed during the first 6h of germination and is secreted into the medium. Disruption of the cetA gene seemingly results in delayed germination, slow growth, abnormal hyphal branching, and cell-wall defects. However, further analysis shows that the mutant phenotype is the result of glucose-dependent transcriptional repression of the pyr4 selectable marker used to disrupt the cetA gene. This is the first time that repression of a selectable marker ("position effect") has been reported in A. nidulans, a finding that may well be of significance in the analysis and interpretation of mutant phenotypes in this organism.

  20. Suppression and enhancement of the Aspergillus nidulans medusa mutation by altered dosage of the bristle and stunted genes.

    PubMed

    Busby, T M; Miller, K Y; Miller, B L

    1996-05-01

    Asexual reproduction in Aspergillus nidulans is characterized by the orderly differentiation of multicellular reproductive structures (conidiophores) and chains of uninucleate conidia (spores). Mutations in the developmental modifier medusa (medA) result in aberrant conidiophores with branching chains of reiterated reproductive cells (metulae), delayed conidial differentiation and frequent reinitiation of secondary conidiophores. We show that incorrect morphology is in part a consequence of modified bristle (brlA) and abacus (abaA) expression, key regulators of the core genetic pathway directing conidial differentiation. First, correct temporal expression of both brlA transcripts (brlA alpha and brlA beta) requires MedAp. Second, MedAp functions as a coactivator required for normal levels of abaA expression. Finally, we show that wild-type morphology results from a finely tuned balance in the expression of brlA, medA and the developmental modifier stunted (stuA). One extra copy of brlA suppresses medA mutations and restores normal abaA mRNA abundance. In contrast, an extra copy of stuA in a medA- strain results in an enhanced medusoid phenotype with extensive metulae proliferation and nearly complete absence of conidia. abaA and brlA alpha transcription are completely repressed in these strains. In general, low stuA:brlA ratios promoted conidiation while high ratios caused proliferation of unicellular sterigmata and inhibited conidiation.

  1. Human neutrophils produce extracellular traps against Paracoccidioides brasiliensis.

    PubMed

    Mejía, Susana P; Cano, Luz E; López, Juan A; Hernandez, Orville; González, Ángel

    2015-05-01

    Neutrophils play an important role as effector cells and contribute to the resistance of the host against microbial pathogens. Neutrophils are able to produce extracellular traps (NETs) in response to medically important fungi, including Aspergillus spp., Candida albicans and Cryptococcus gattii. However, NET production in response to Paracoccidioides brasiliensis has yet to be studied. We have demonstrated that human neutrophils produce NETs against both conidia and yeasts of P. brasiliensis. Although the NADPH oxidase inhibitor diphenyleneiodonium chloride (DPI) did not alter NET production against conidia, it partially suppressed NET formation against P. brasiliensis yeasts. Cytochalasin D or IFN-γ did not affect the production of NETs against the fungus. Additionally, a mutant strain of P. brasiliensis with reduced expression of an alternative oxidase induced significantly higher levels of NETs in comparison with the WT strain. Finally, c.f.u. quantification of P. brasiliensis showed no significant differences when neutrophils were treated with DPI, DNase I or cytochalasin D as compared with untreated cells. These data establish that NET formation by human neutrophils appears to be either dependent or independent of reactive oxygen species production, correlating with the fungal morphotype used for stimulation. However, this mechanism was ineffective in killing the fungus.

  2. Morphological and physiological comparison of taxa comprising the Sporothrix schenckii complex*

    PubMed Central

    ZHAO, Ming-dan; ZHOU, Xun; LIU, Ting-ting; YANG, Zhi-bang

    2015-01-01

    Based on recent molecular data, it has been suggested that Sporothrix globosa is the main causal agent of sporotrichosis in China. The objective of this study was to compare the morphology, growth characteristics, patterns of carbon source usage, and susceptibility to antifungal agents among Sporothrix strains. A total of 15 clinical strains confirmed to be S. globosa, from three different regions of China, and 11 ex-type strains from the CBS-KNAW biodiversity center were obtained. The elongated conidia of S. pallida, S. variecibatus, S. schenckii, and S. schenckii luriei were clearly different from the subglobose and globose conidia of S. globosa strains. S. schenckii is able to assimilate sucrose, raffinose, and ribitol. Susceptibility profiles of these Sporothrix species were evaluated by measuring minimum inhibitory concentrations (MICs). Fluconazole, itraconazole, terbinafine, and amphotericin B showed good activity against most S. globosa clinical isolates from China. Potassium iodide also showed a low MIC against S. pallida, while fluconazole showed a high MIC for S. mexicana, S. humicola, S. globosa, S. schenckii, and S. inflata; these strains might be considered tolerant. The species showed differences in susceptibility to antifungal drugs and should therefore be properly identified during diagnosis prior to designing therapeutic strategies. PMID:26537212

  3. Development of a Filtration-Based Bioluminescence Assay for Detection of Microorganisms in Tea Beverages.

    PubMed

    Shinozaki, Yohei; Igarashi, Toshinori; Harada, Yasuhiro

    2016-03-01

    The market for tea drinks as healthy beverages has been steadily expanding, and ready-to-drink beverages in polyethylene terephthalate bottles have been popular. To more rapidly and accurately test tea beverages bottled in polyethylene terephthalate for microbial contamination, a newly developed filtration device and a washing method with a commercial bioluminescence assay were combined to detect low numbers of bacterial spores, fungal conidia, and ascospores. Washing buffers were formulated with nonionic detergents from the Tween series. Commercially available tea beverages were used to evaluate the filtration capacity of the filtration device, the effect of washing buffers, and the performance of the assay. The assay was tested with serially diluted suspensions of colonies of two bacterial strains, spores of three Bacillus strains, conidia of five fungal strains, and ascospores of four fungal strains. The filtration device enabled filtration of a large sample volume (100 to 500 ml), and the washing buffer significantly decreased the background bioluminescence intensity of tea samples when compared with the no-washing method. Low numbers (1 to 10 CFU/100 ml) of the tested strains of bacteria were detected within 8 to 18 h of cultivation, and fungi were detected within 24 to 48 h. Furthermore, a whole bottle (500 ml) of mixed tea was filtered through the filtration device and microbes were detected. This method could be used for quality control of bottled beverages without preincubation.

  4. Passive vectoring of entomopathogenic fungus Beauveria bassiana among the wax moth Galleria mellonella larvae by the ectoparasitoid Habrobracon hebetor females.

    PubMed

    Kryukov, Vadim Yu; Kryukova, Natalia A; Tyurin, Maksim V; Yaroslavtseva, Olga N; Glupov, Viktor V

    2017-03-15

    Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly (1.5-13 fold) increased the mycoses level in clusters of G. mellonella, with 40 % of the larvae infected with fungal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4-fold. An enhanced germination rate (2-fold) was registered in the n-hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase (PO) activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor. This article is protected by copyright. All rights reserved.

  5. The Sch9 Kinase Regulates Conidium Size, Stress Responses, and Pathogenesis in Fusarium graminearum

    PubMed Central

    Zhou, Xiaoying; Wang, Yulin; Xu, Jin-Rong

    2014-01-01

    Fusarium head blight caused by Fusarium graminearum is an important disease of wheat and barley worldwide. In a previous study on functional characterization of the F. graminearum kinome, one protein kinase gene important for virulence is orthologous to SCH9 that is functionally related to the cAMP-PKA and TOR pathways in the budding yeast. In this study, we further characterized the functions of FgSCH9 in F. graminearum and its ortholog in Magnaporthe oryzae. The ΔFgsch9 mutant was slightly reduced in growth rate but significantly reduced in conidiation, DON production, and virulence on wheat heads and corn silks. It had increased tolerance to elevated temperatures but became hypersensitive to oxidative, hyperosmotic, cell wall, and membrane stresses. The ΔFgsch9 deletion also had conidium morphology defects and produced smaller conidia. These results suggest that FgSCH9 is important for stress responses, DON production, conidiogenesis, and pathogenesis in F. graminearum. In the rice blast fungus Magnaporthe oryzae, the ΔMosch9 mutant also was defective in conidiogenesis and pathogenesis. Interestingly, it also produced smaller conidia and appressoria. Taken together, our data indicate that the SCH9 kinase gene may have a conserved role in regulating conidium size and plant infection in phytopathogenic ascomycetes. PMID:25144230

  6. Agrobacterium tumefaciens-mediated genetic transformation of the entomopathogenic fungus Beauveria bassiana.

    PubMed

    dos Reis, Maria Cecília; Pelegrinelli Fungaro, Maria Helena; Delgado Duarte, Rubens Tadeu; Furlaneto, Luciana; Furlaneto, Marcia Cristina

    2004-08-01

    Agrobacterium tumefaciens-mediated transformation (agro-transformation) was successfully applied to the entomogenous fungus Beauveria bassiana. Conidia of B. bassiana were transformed to hygromycin B resistance using the hph gene of Escherichia coli as the selective trait, under the control of a heterologous fungal promoter and the Aspergillus nidulans trpC terminator. The efficiency of transformation was up to 28 and 96 transformants per 10(4) and 10(5) target conidia, respectively, using three distinct vectors. High mitotic stability of the transformants (80-100%) was demonstrated after five successive transfers on a nonselective medium. Abortive transformants were observed for all the hph(r) vectors used. Putative transformants were analysed for the presence of the hph gene by PCR and Southern analysis. The latter analysis revealed the integration of two or more copies of the hph gene in the genome. The agro-transformation method was found to be effective for the isolation of B. bassiana hygromycin resistant transformants and may represent a useful tool for insertional mutagenesis studies in this fungus.

  7. Isolation and characterization of the grain mold fungi Cochliobolus and Alternaria spp. from sorghum using semiselective media and DNA sequence analyses.

    PubMed

    Funnell-Harris, Deanna L; Prom, Louis K; Pedersen, Jeffrey F

    2013-02-01

    Mold diseases, caused by fungal complexes including Alternaria, Cochliobolus, and Fusarium species, limit sorghum grain production. Media were tested by plating Fusarium thapsinum, Alternaria sp., and Curvularia lunata, individually and competitively. Dichloran chloramphenicol rose bengal (DRBC) and modified V8 juice (ModV8) agars, found to be useful, were compared with commonly used agar media, dichloran chloramphenicol peptone (DCPA) and pentachloronitrobenzene (PCNB). Radial growth, starting with mycelia or single-conidia and hyphal tips, demonstrated an effect of media. For isolation of grain fungi, DRBC and ModV8 were similar or superior to DCPA and PCNB. When seedlings were inoculated with conidia of C. lunata, Alternaria sp., F. thapsinum, or mixtures, the percentage of root infection ranged from 28% to 77%. For mixed inoculations, shoot weights, lesion lengths, and percentage of root infections were similar to F. thapsinum inoculations; most colonies recovered from roots were F. thapsinum. For Alternaria grain isolates, 5 morphological types, including Alternaria alternata, were distinguished by colony morphologies and conidial dimensions. Sequence analysis using a portion of the endo-polygalacturonase gene was able to further distinguish isolates. Cochliobolus isolates were identified morphologically as C. lunata, Curvularia sorghina, and Bipolaris sorghicola. Multiple molecular genotypes were apparent from rRNA internal transcribed spacer region sequences from Cochliobolus grain isolates.

  8. Trans-resveratrol concentrations and antimutagenic potential of juice from the grape cultivars Vênus, BRS Violeta and Isabel.

    PubMed

    Polonio, N C V; Rocha, C L M S C; Clemente, E

    2014-02-25

    Grape juice, in addition to being an energetic food, due to its high sugar content, has several compounds that can prevent or treat various types of diseases. Resveratrol is a compound present in grapes that has attracted a lot of interest; in addition to preventing cardiovascular disease linked to lipid metabolism, it has chemopreventive and chemotherapeutic activities. We evaluated the antimutagenic activity and determined the trans-resveratrol content in grape juice from the varieties Vênus, BRS Violeta and Isabel. The grape juices from the three cultivars and the resveratrol solution were tested in the methG1 system in Aspergillus nidulans. The conidia from the biA1methG1 strain were treated for 4 h in 10% grape juice (v/v). After washing, the conidia were placed in selective media to analyze survival and mutations. The standard resveratrol solution and the grape juice of the cultivar Isabel, both with a trans-resveratrol content of 1 mg/mL, presented antimutagenic potential in this test system because the frequency of mutation of the treatments was significantly lower than the frequency of spontaneous mutation. However, grape juice from the varieties Vênus and BRS Violeta, both with a lower quantity of trans-resveratrol, gave weak antimutagenic activity in this test system because the frequency of mutation of the treatments was significantly higher than the frequency of spontaneous mutation.

  9. Agrobacterium tumefaciens-mediated transformation of the entomopathogenic fungus Nomuraea rileyi.

    PubMed

    Shao, Changwen; Yin, Youping; Qi, Zhaoran; Li, Ren; Song, Zhangyong; Li, Yan; Wang, Zhongkang

    2015-10-01

    An Agrobacterium-mediated genetic transformation system for the entomopathogenic fungus Nomuraea rileyi was established. Three binary T-DNA vectors, pPZP-Hph, pPZP-Hph-RNAi and pPZP-Hph-DsRed2, were constructed. The trpc promoter from Aspergillus nidulans was used as the cis-regulatory element to drive the expression of hygromycin phosphotransferase (hph) gene and DsRed2, which conferred the hygromycin B (Hyg B) resistance and red fluorescence visualization, respectively. The blastospores and conidia were used as the recipients. The blastospores' transformation efficiency reached ∼20-40 transformants per 10(6) blastospores, whereas the conidia were not transformed. Based on an analysis of five generations of subcultures, PCR and Southern blotting assays, the Ptrpc-hph cassette had integrated into the genomes of all transformants, which contained single copy of the hph gene and showed mitotic stability. Abundant altered morphologic phenotypes in colonies, blastospores and hyphae formations were observed in the arbitrary insertional mutants of N. rileyi, which made it possible to study the relationships between the functions and the interrupted genes over the whole genome. The transformation protocol will promote the functional characterization of genes, and the construction of genetically engineered strains of this important entomopathogenic fungus, and potentially of other similar fungal pathogens.

  10. Effects of Two Salts Compounds on Mycelial Growth, Sporulation, and Spore Germination of Six Isolates of Botrytis cinerea in the Western North of Algeria

    PubMed Central

    Boumaaza, Boualem; Benkhelifa, Mohamed; Belkhoudja, Moulay

    2015-01-01

    Six isolates of Botrytis cinerea were isolated from leaves and stems of different tomato varieties taken from four areas in the northwest of Algeria where tomato is mostly grown in greenhouses and high tunnels. The purpose of this research was to determine the effect of two salts, NaCl and CaCl2, on three stages of Botrytis cinerea's life cycle. All isolates tested were stimulated in 50 to 150 ppm; NaCl was the most effective treatment to increase mycelial growth at two tested concentrations. However, at 300 ppm concentration, CaCl2 completely inhibited the growth of mycelium; they reach 34.78% for the isolate TR46 and 26.72% for isolate F27. The sodium and calcium salts stimulated conidia production in liquid culture. We noticed that the effect of calcium chloride on sporulation was average while sodium chloride. In the medium containing 50 ppm, calcium chloride and sodium chloride increased the germination capacity of most isolates compared with the control. Other calcium salts, at 100 or 300 ppm, decreased the germination percentage of the conidia. With the exception of sodium salts, the inhibitions of germination reduce at 150 or 300 compared with the control. Conidial germination was slightly inhibited by sodium chloride only when the concentration was over 300 ppm. PMID:25883657

  11. Changes in development and ultrastructure of Aspergillus niger mycelium, strain with increased tolerance to toxic substances from beet molasses.

    PubMed

    Zakowska, Z; Gabara, B

    1991-01-01

    Effects of a defoamer and toxic molasses compounds on development and ultrastructure of A. niger mycelium, strain Z, characterized by high tolerance to these substances and producing citric acid in surface fermentation on proper molasses media with 70% yield were presented. Spumol BJ in concentration of 5 microliters/100 cm3 as well as toxic molasses compounds stimulated the process of swelling and germinating of conidia. Moreover, giant conidia, unable to germinate, appeared. Developing mycelium with dispersed hyphae became mucilaginous after 17-20 h culture, which indicated the process of sinking but after 24 h some part of the mycelium developed normally. Electron microscopic observations of mycelium developing in the presence of the toxic substances showed along with electron-transparent cytoplasm in a consequence of decrease in ribosome number, changes in ultrastructure of mitochondria. It may be assumed that one of the reasons of the above described abnormalities in development and ultrastructure of mycelium was a disturbance of respiration processes. The appearance of deposits of electron-dense material in mitochondria suggested the existence of a defence mechanism, eliminating toxic substances.

  12. Morphological study of a variant of Paracoccidioides brasiliensis that exists in the yeast form at room temperature.

    PubMed

    Villar, L A; Salazar, M E; Restrepo, A

    1988-01-01

    Incubation of Paracoccidioides brasiliensis conidia at 20-25 degrees C (RT) results in two types of colonies, mycelial (M) and yeast (YRT). A study of the latter colonies was undertaken. Conidia were plated in complex (BHI) and chemically-defined media (CDCM), with and without fetal calf serum (FCS). Incubation was carried out at 21 degrees C for 4 weeks. The mean number of YRT colonies was approximately 18.5% on BHI agar. Selected YRT colonies were transferred to liquid CDCM, incubated 7 days at 21 degrees C and transferred to solid media; YRT appearance was preserved in 95% of the colonies if media were FCS-supplemented; otherwise, most colonies reverted to the M form. When FCS was replaced by bovine albumin or by alpha-globulin, 63% and 68% respectively of the colonies obtained after plating YRT cells, became mycelial. Comparative morphologic studies of both YRT and yeasts grown at 37 degrees C suggested that there were no major differences between these two types of yeast cells when size and budding were taken into consideration. The results indicate that in this particular variant, dimorphism is not exclusively temperature-dependent.

  13. Populational parameters of Spalangia endius Walker (Hymenoptera: Pteromalidae) on Pupae of Musca domestica L. (Diptera: Muscidae) treated with two strains of Beauveria bassiana (Bals.) Vuil. (Deuteromycetes).

    PubMed

    Lecuona, Roberto; Crespo, Diana; La Rossa, Francisco

    2007-01-01

    The parasitoid Spalangia endius Walker is an efficient controller of Dipteran pupae, such as Musca domestica L. The entomopathogenic fungus Beauveria bassiana (Bals.) Vuil. is a regulator of insect populations, including these synanthropic pests. The aim of this work was to explore the possibilities of utilizing both agents in a combined form for the biocontrol of the domestic fly. Recently formed M. domestica pupae were inoculated by immersion in conidia suspension (10(8) conidia/ml) with two strains of B. bassiana (Bb6 and Bb10). The inoculated pupae were offered to the female parasitoid. In one bioassay they were offered pupae inoculated a single day and in other, pupae inoculated the following day as well. In both bioassays non inoculated (control) pupae were offered to the parasitoids until their death. Thirty females of S. endius were used for each strain and bioassay. From the study of the parasitoid offspring, life tables were built and the reproduction net rate (R(0)) and intrinsic natural increase (r(m)) were obtained among other demographic parameters; the parasitism percentages and sex ratios were also analyzed. B. bassiana did not affect significantly the biodemography of the parasitoid when pupae were inoculated a single time. On the other hand the R0 and the rm were smaller than that of the control without the fungus when pupae were inoculated twice, although sporulation was not observed in the cadavers of S. endius.

  14. Expression profile of lncRNA in human bronchial epithelial cells response to Talaromyces marneffei infection: A microarray analysis.

    PubMed

    Li, Yinghua; Li, Meihua; Luo, Honglin; Bai, Jing; Zhang, Jianquan; Zhong, Xiaoning; Lan, Xiuwan; He, Zhiyi

    2017-03-01

    Talaromyces marneffei is an important opportunistic pathogenic fungus capable of causing systemic lethal infection through inhalation of its conidia. However, little is known about the pathogenesis and interactions between Talaromyces marneffei and host. The aim of this study was to identify potential long noncoding RNAs (lncRNAs) and coding genes associated with interactions between airway epithelial cell and Talaromyces marneffei conidia. We carried out a microarray analysis to determine the expression profile of lncRNA and mRNA in human bronchial epithelial cell in response to Talaromyces marneffei infection. Compared to control group, we found that 370 and 149 lncRNAs were up and down regulated, respectively. Meanwhile, the expression level of 269 and 60 mRNAs was increased and decreased, respectively. To understand the potential role of the differentially expressed lncRNAs, we performed functional annotations of the corresponding coding genes using gene ontology and pathway analyses. Our results provide insights into the pathogenesis of early infection by Talaromyces marneffei.

  15. The production and uses of Beauveria bassiana as a microbial insecticide.

    PubMed

    Mascarin, Gabriel Moura; Jaronski, Stefan T

    2016-11-01

    Among invertebrate fungal pathogens, Beauveria bassiana has assumed a key role in management of numerous arthropod agricultural, veterinary and forestry pests. Beauveria is typically deployed in one or more inundative applications of large numbers of aerial conidia in dry or liquid formulations, in a chemical paradigm. Mass production is mainly practiced by solid-state fermentation to yield hydrophobic aerial conidia, which remain the principal active ingredient of mycoinsecticides. More robust and cost-effective fermentation and formulation downstream platforms are imperative for its overall commercialization by industry. Hence, where economics allow, submerged liquid fermentation provides alternative method to produce effective and stable propagules that can be easily formulated as dry stable preparations. Formulation also continues to be a bottleneck in the development of stable and effective commercial Beauveria-mycoinsecticides in many countries, although good commercial formulations do exist. Future research on improving fermentation and formulation technologies coupled with the selection of multi-stress tolerant and virulent strains is needed to catalyze the widespread acceptance and usefulness of this fungus as a cost-effective mycoinsecticide. The role of Beauveria as one tool among many in integrated pest management, rather than a stand-alone management approach, needs to be better developed across the range of crop systems. Here, we provide an overview of mass-production and formulation strategies, updated list of registered commercial products, major biocontrol programs and ecological aspects affecting the use of Beauveria as a mycoinsecticide.

  16. Disease and colony foundation in the dampwood termite Zootermopsis angusticollis: The survival advantage of nestmate pairs

    NASA Astrophysics Data System (ADS)

    Calleri, Daniel V.; Rosengaus, Rebeca B.; Traniello, James F. A.

    2005-06-01

    To determine the impact of inbreeding and outbreeding on disease resistance and survival during colony foundation, nestmate (NM) and non-nestmate (NON) primary reproductives of the dampwood termite Zootermopsis angusticollis were exposed to a single or double dose of conidia of the entomopathogenic fungus Metarhizium anisopliae. Male and female primary reproductive pairs originating from the same parent colony had higher survivorship than NON pairs in control and conidia-exposure treatments. The survival advantage of NM primary reproductives increased with the intensity of pathogen challenge and was significantly greater in the single- and double-dose treatments than in the controls. Although NM pairs had significantly lower mortality than NON pairs, the survivorship of colonies stabilized as they matured and inbred and outbred colonies did not differ in offspring production. These results demonstrate that colony foundation by NON male and female reproductives may have a disease-related survival cost during this critical phase of their life cycle. There may also be a cost associated with lower offspring heterozygosity, but in the first generation this does not appear to significantly impact colony growth.

  17. Penicillium fusisporum and P. zhuangii, Two New Monoverticillate Species with Apical-Swelling Stipes of Section Aspergilloides Isolated from Plant Leaves in China

    PubMed Central

    Wang, Long

    2014-01-01

    Two new Penicillium species isolated from plant leaves are reported here, namely, P. fusisporum (type strain AS3.15338T = NRRL 62805T = CBS 137463T) and P. zhuangii (type strain AS3.15341T = NRRL 62806T = CBS 137464T). P. fusisporum is characterized by fast growth rate, apical-swelling monoverticillate penicilli, verrucose stipes, fusiform to oblong conidia about 3.5–4×2–2.5 µm and cinnamon-colored sclerotia. While P. zhuangii presents a moderate growth rate, it also bears apical-swelling monoverticillate penicilli but its stipes are smooth-walled, and produces ovoid to globose smooth-walled conidia about 3–3.5 µm. Both species belong to section Aspergilloides, and P. fusisporum is related to “P. thomii var. flavescens”, while P. zhuangii is morphologically similar to P. lividum. Phylogenetic analyses of sequences of calmodulin and beta-tubulin genes both show that the two new taxa form distinct monophyletic clades. PMID:24988489

  18. Suppression and Enhancement of the Aspergillus Nidulans Medusa Mutation by Altered Dosage of the Bristle and Stunted Genes

    PubMed Central

    Busby, T. M.; Miller, K. Y.; Miller, B. L.

    1996-01-01

    Asexual reproduction in Aspergillus nidulans is characterized by the orderly differentiation of multicellular reproductive structures (conidiophores) and chains of uninucleate conidia (spores). Mutations in the developmental modifier medusa (medA) result in aberrant conidiophores with branching chains of reiterated reproductive cells (metulae), delayed conidial differentiation and frequent reinitiation of secondary conidiophores. We show that incorrect morphology is in part a consequence of modified bristle (brlA) and abacus (abaA) expression, key regulators of the core genetic pathway directing conidial differentiation. First, correct temporal expression of both brlA transcripts (brlAα and brlAβ) requires MedAp. Second, MedAp functions as a coactivator required for normal levels of abaA expression. Finally, we show that wild-type morphology results from a finely tuned balance in the expression of brlA, medA and the developmental modifier stunted (stuA). One extra copy of brlA suppresses medA mutations and restores normal abaA mRNA abundance. In contrast, an extra copy of stuA in a medA(-) strain results in an enhanced medusoid phenotype with extensive metulae proliferation and nearly complete absence of conidia. abaA and brlAα transcription are completely repressed in these strains. In general, low stuA:brlA ratios promoted conidiation while high ratios caused proliferation of unicellular sterigmata and inhibited conidiation. PMID:8722771

  19. UV photobiochemistry under space conditions

    NASA Astrophysics Data System (ADS)

    Dose, K.; Bieger-Dose, A.; Dillmann, R.; Gill, M.; Kerz, O.; Klein, A.; Stridde, C.

    The response of spores of Bacillus subtilis, cells of Deinococcus radiodurans and conidia of Aspergillus ochraceus to actual and simulated space conditions (UV in combination with long-term exposure to extremely dry conditions, including vacuum) has been studied: The following effects have been analyzed: decrease of viability, occurrence of DNA double strand breaks, formation of DNA-protein cross-links and DNA-DNA cross-links. All organisms show an increased sensitivity to UV light in extreme dryness (dry argon or vacuum) compared to an irradiation in aqueous suspension. The UV irradiation leads in all cases to a variety of DNA lesions. Very conspicuous is the occurrence of double strand breaks. Most of these double strand breaks are produced by incomplete repair of other lesions, especially base damages. The increase in DNA lesions can be correlated to the loss in viability. The specific response of the chromosomal DNA to UV irradiation in extreme dryness, however, varies from species to species and depends on the state of dehydration. The formation of DNA double strand breaks and DNA-protein cross-links prevails in the case of B. subtilis spores. In cells of Deinococcus radiodurans DNA-DNA cross-links often predominate, in conidia of Aspergillus ochraceus double strand breaks. The results obtained by direct exposure to space conditions (EURECA mission and D2 mission) largely agree with the laboratory data.

  20. Inducible immune proteins in the dampwood termite Zootermopsis angusticollis

    NASA Astrophysics Data System (ADS)

    Rosengaus, Rebeca B.; Cornelisse, Tara; Guschanski, Katerina; Traniello, James F. A.

    2007-01-01

    Dampwood termites, Zootermopsis angusticollis (Isoptera: Termopsidae), mount an immune response to resist microbial infection. Here we report on results of a novel analysis that allowed us to electrophoretically assess changes in hemolymph proteins in the same individual before and after exposure to a pathogen. We demonstrate that contact with a sublethal concentration of the entomopathogenic fungus Metarhizium anisopliae (Deuteromycotina:Hypomycetes) induces the production of protective proteins in nymphs, pseudergates (false workers), and soldiers. Termites exposed to an immunizing dosage of fungal conidia consistently showed an enhancement of constitutive proteins (62-85 kDa) in the hemolymph as well as an induction of novel proteins (28-48 kDa) relative to preimmunization levels. No significant differences in protein banding patterns relative to baseline levels in control and naïve termites were observed. Incubating excised and eluted induced proteins produced by immunized pseudergates or immunized soldiers with conidia significantly reduced the germination of the fungus. The fungistatic effect of eluted proteins differed significantly among five colonies examined. Our results show that the upregulation of protective proteins in the hemolymph underscores the in vivo immune response we previously recorded in Z. angusticollis.

  1. Olfactory Cues from Pathogenic Fungus Affect the Direction of Motion of Termites, Coptotermes formosanus.

    PubMed

    Yanagawa, Aya; Imai, Tomoya; Akino, Toshiharu; Toh, Yoshihiro; Yoshimura, Tsuyoshi

    2015-12-01

    Formosan subterranean termites, Coptotermes formosanus, tend to avoid pathogen odors when tested in Y-tube olfactometers, but approach and groom exposed nestmates to remove pathogens from their cuticle and maintain a healthy population. To better understand their differential reaction to pathogens and their odors, the relationship between odor cues and direction of motion was examined with the fungus Isaria fumosorosea K3 strain. The results indicate that nestmate odor was strongly attractive only in tests where fungal odors were present in both branches of the olfactometer. Termites generally avoid fungal odors when offered a choice without fungal odor. We also tested termite aversion to 3-octanone and 1-octen-3-ol, major surface chemical compounds of I. fumosorosea K3, and estimated the total mass of these compounds present on the conidial surface by direct extraction method. The total quantity of these chemicals on the surface of fungal conidia was estimated to be approximately 0.01 ng per 10(7) conidia. This study demonstrates a context dependent behavioral change in termites in response to the odors of pathogenic fungi.

  2. Fungal Volatiles Can Act as Carbon Sources and Semiochemicals to Mediate Interspecific Interactions Among Bark Beetle-Associated Fungal Symbionts

    PubMed Central

    Collignon, R. Maxwell; Klutsch, Jennifer G.; Kanekar, Sanat S.; Hussain, Altaf; Erbilgin, Nadir

    2016-01-01

    Mountain pine beetle (Dendroctonus ponderosae) has killed millions of hectares of pine forests in western North America. Beetle success is dependent upon a community of symbiotic fungi comprised of Grosmannia clavigera, Ophiostoma montium, and Leptographium longiclavatum. Factors regulating the dynamics of this community during pine infection are largely unknown. However, fungal volatile organic compounds (FVOCs) help shape fungal interactions in model and agricultural systems and thus may be important drivers of interactions among bark beetle-associated fungi. We investigated whether FVOCs can mediate interspecific interactions among mountain pine beetle’s fungal symbionts by affecting fungal growth and reproduction. Headspace volatiles were collected and identified to determine species-specific volatile profiles. Interspecific effects of volatiles on fungal growth and conidia production were assessed by pairing physically-separated fungal cultures grown either on a carbon-poor or -rich substrate, inside a shared-headspace environment. Fungal VOC profiles differed by species and influenced the growth and/or conidia production of the other species. Further, our results showed that FVOCs can be used as carbon sources for fungi developing on carbon-poor substrates. This is the first report demonstrating that FVOCs can drive interactions among bark beetle fungal symbionts, and thus are important factors in beetle attack success. PMID:27583519

  3. Development and Use of Flow Cytometry for Detection of Airborne Fungi

    PubMed Central

    Prigione, Valeria; Lingua, Guido; Marchisio, Valeria Filipello

    2004-01-01

    Traditional methods for the enumeration of airborne fungi are slow, tedious, and rather imprecise. In this study, the possibility of using flow cytometry (FCM) for the assessment of exposure to the fungus aerosol was evaluated. Epifluorescence microscopy direct counting was adopted as the standard for comparison. Setting up of the method was achieved with pure suspensions of Aspergillus fumigatus and Penicillium brevicompactum conidia at different concentrations, and then analyses were extended to field samples collected by an impinger device. Detection and quantification of airborne fungi by FCM was obtained combining light scatter and propidium iodide red fluorescence parameters. Since inorganic debris are unstainable with propidium iodide, the biotic component could be recognized, whereas the preanalysis of pure conidia suspensions of some species allowed us to select the area corresponding to the expected fungal population. A close agreement between FCM and epifluorescence microscopy counts was found. Moreover, data processing showed that FCM can be considered more precise and reliable at any of the tested concentrations. PMID:15006754

  4. Small-Scale DNA Sample Preparation Method for Field PCR Detection of Microbial Cells and Spores in Soil

    PubMed Central

    Kuske, Cheryl R.; Banton, Kaysie L.; Adorada, Dante L.; Stark, Peter C.; Hill, Karen K.; Jackson, Paul J.

    1998-01-01

    Efficient, nonselective methods to obtain DNA from the environment are needed for rapid and thorough analysis of introduced microorganisms in environmental samples and for analysis of microbial community diversity in soil. A small-scale procedure to rapidly extract and purify DNA from soils was developed for in-the-field use. Amounts of DNA released from bacterial vegetative cells, bacterial endospores, and fungal conidia were compared by using hot-detergent treatment, freeze-thaw cycles, and bead mill homogenization. Combining a hot-detergent treatment with bead mill homogenization gave the highest DNA yields from all three microbial cell types and provided DNA from the broadest range of microbial groups in a natural soil community. Only the bead mill homogenization step was effective for DNA extraction from Bacillus globigii (B. subtilis subsp. niger) endospores or Fusarium moniliforme conidia. The hot-detergent–bead mill procedure was simplified and miniaturized. By using this procedure and small-scale, field-adapted purification and quantification procedures, DNA was prepared from four different soils seeded with Pseudomonas putida cells or B. globigii spores. In a New Mexico soil, seeded bacterial targets were detected with the same sensitivity as when assaying pure bacterial DNA (2 to 20 target gene copies in a PCR mixture). The detection limit of P. putida cells and B. globigii spores in different soils was affected by the amount of background DNA in the soil samples, the physical condition of the DNA, and the amount of DNA template used in the PCR. PMID:9647816

  5. Production of an Extracellular Matrix as an Isotropic Growth Phase of Penicillium rubens on Gypsum

    PubMed Central

    Bekker, M.; Adan, O. C. G.; Samson, R. A.; Wyatt, T.; Dijksterhuis, J.

    2012-01-01

    Indoor mold represents an important environmental concern, but a fundamental knowledge of fungal growth stages is needed to limit indoor fungal proliferation on finishing materials used in buildings. The present study focused on the succession of germination stages of the common indoor fungus Penicillium rubens on a gypsum substrate. This substrate is used as a model system representing porous materials that are widely used in indoor environments. Imaging with cryo-scanning electron microscopy showed that the formation of an extracellular matrix (ECM) is a phase of the isotropic growth of P. rubens that is uniquely related to germinating conidia. Furthermore, the ECM is observed only when a dry-state inoculation of the surface is applied, i.e., applying conidia directly from a 7-day-old colony, mimicking airborne contamination of the surface. When inoculation is done by spraying an aqueous conidial suspension, no ECM is observed. Moreover, it is concluded that the formation of an ECM requires active processes in the fungal cell. The porosity of the substrate proved that the ECM substance has high-viscosity characteristics. The present results stress that studies of indoor fungal growth should consider the method of inoculation, knowing that the common aqueous suspension may obscure specific stages in the initial phases of germination. PMID:22843536

  6. Nomuraea rileyi as biological control agents of Rhipicephalus microplus tick.

    PubMed

    Perinotto, W M S; Terra, A L M; Angelo, I C; Fernandes, É K K; Golo, P S; Camargo, M G; Bittencourt, V R E P

    2012-10-01

    Nomuraea rileyi, a fungus pathogenic to insects, has been widely used for biological control of agricultural pests in Brazil. This study investigates the effects of N. rileyi, isolates Nr 138, Nr 151, and Nr 177, to eggs, larvae, and engorged females of Rhipicephalus microplus tick. Specimens were immersed in 1 ml of conidial suspension for 3 min, whereas the control group was immersed in 0.01% Tween 80 water solution. The isolate Nr 138 controlled 67.37% of ticks when the highest conidial concentration was used, 10(8) conidia ml(-1). The isolate Nr 177 significantly reduced the percentage of hatch of larvae from eggs treated with 10(8) conidia ml(-1). Conversely, the isolate Nr 151 was not virulent to eggs, larvae, or adults. Variability in virulence was observed among the N. rileyi isolates investigated in the current study-Nr 138 was more virulent to engorged females, while Nr 177 was more virulent to unfed larvae. Although N. rileyi proved to be virulent to several stages of R. microplus, the results obtained in this study indicate that N. rileyi does not appear to be a remarkable biological control agent for R. microplus.

  7. Putative use of a Bacillus subtilis L194 strain for biocontrol of Phoma medicaginis in Medicago truncatula seedlings.

    PubMed

    Ben Slimene, Imen; Tabbene, Olfa; Djebali, Naceur; Cosette, Pascal; Schmitter, Jean Marie; Jouenne, Thierry; Urdaci, Maria-Camino; Limam, Ferid

    2012-06-01

    An antagonist L194 strain against Phoma medicaginis pathogenic fungi was isolated from Tunisian soil (vicinity of Tunis) and identified as Bacillus subtilis based on biochemical characteristics and partial 16S rDNA sequence. When cells were grown in a minimal medium for 24 h, spore culture supernatant exhibited 2-fold higher antifungal activity than vegetative cells. MALDI-TOF mass spectrometry analysis showed that L194 spores produced mainly iturins, surfactins and fengycins with long-chain fatty acids, and other not yet identified compounds. Both vegetative cells and spores of L194 efficiently reduced germination of P. medicaginis conidia. As revealed by atomic force microscopy, L194 spores modified conidia morphology from a regular to a deflated shape. Data suggest that lipopeptides interacted with the cytoplasmic membrane, causing pore formation. In vivo, L194 spores were highly protective against P. medicaginis by reducing disease symptoms and alleviating growth disturbance of Medicago truncatula seedlings. As a whole, the lipopeptide-producing L194 strain may be successfully used in biocontrol of plant diseases induced by phytopathogenic fungi such as P. medicaginis.

  8. [Determination of LC 90 and LT 90 of IBCB66 Beauveria bassiana (Ascomycetes: Clavicipitaceae) isolate for Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) control].

    PubMed

    Barci, Leila A G; de Almeida, José Eduardo M; de Campos Nogueira, Adriana H; do Prado, Angelo P

    2009-12-01

    The objective of this research was to evaluate the pathogenicity and the virulence of the IBCB66 isolate of Beauveria bassiana on infected larvae of Rhipicephalus (Boophilus) microplus. The IBCB66 fungus strain was used as standard isolates of B. bassiana against R. (B.) microplus larvae. The larval bioassay tests using the IBCB66 isolate were carried out to determine the (Lethal Concentration) LC50, LC90, (Lethal Time) LT50 and LT90. The IBCB66 fungus strain was tested at six different concentrations (5x10(6), 10(7), 5x10(7), 10(8), 5x10(8) and 10(9) conidia.mL(-1)) to determine the percentage of larval mortality. In addition, a Probit analysis was also performed. Total larval mortality was observed eighteen days after the beginning of the test in the group treated with 5x10(9) conidia.mL(1). The LC50 and LC90 were 3x10(7) and 5x10(8) respectively and the LT50 and LT90 were 10 and 16 days.

  9. Interaction of the pathogenic mold Aspergillus fumigatus with lung epithelial cells

    PubMed Central

    Osherov, Nir

    2012-01-01

    Aspergillus fumigatus is an opportunistic environmental mold that can cause severe allergic responses in atopic individuals and poses a life-threatening risk for severely immunocompromised patients. Infection is caused by inhalation of fungal spores (conidia) into the lungs. The initial point of contact between the fungus and the host is a monolayer of lung epithelial cells. Understanding how these cells react to fungal contact is crucial to elucidating the pathobiology of Aspergillus-related disease states. The experimental systems, both in vitro and in vivo, used to study these interactions, are described. Distinction is made between bronchial and alveolar epithelial cells. The experimental findings suggest that lung epithelial cells are more than just “innocent bystanders” or a purely physical barrier against infection. They can be better described as an active extension of our innate immune system, operating as a surveillance mechanism that can specifically identify fungal spores and activate an offensive response to block infection. This response includes the internalization of adherent conidia and the release of cytokines, antimicrobial peptides, and reactive oxygen species. In the case of allergy, lung epithelial cells can dampen an over-reactive immune response by releasing anti-inflammatory compounds such as kinurenine. This review summarizes our current knowledge regarding the interaction of A. fumigatus with lung epithelial cells. A better understanding of the interactions between A. fumigatus and lung epithelial cells has therapeutic implications, as stimulation or inhibition of the epithelial response may alter disease outcome. PMID:23055997

  10. Interactions involving ozone, Botrytis cinerea, and B. squamosa on onion leaves

    SciTech Connect

    Rist, D.L.

    1983-01-01

    Interactions involving Botrytis cinerea Pers., B. squamosa Walker, and ozone on onion (alium cepae L.) were investigated. Initially, threshold dosages of ozone required to predispose onion leaves to greater infection by B. cinerea and B. squamosa were determined under controlled conditions in an ozone-exposure chamber. Subsequent experiments supported the hypothesis that nutrients leaking out of ozone-injured cells stimulated lesion production by B. cinerea. The electrical conductivity of, and carbohydrate concentration in, dew collected from leaves of onion plants which had been exposed to ozone were greater than the electrical conductivity of, and carbohydrate concentration in, dew collected from leaves of other, non-exposed onion plants. When conidia of B. cinerea were suspended in dew collected from leaves of plants which had been exposed to ozone and the resulting suspension atomized onto leaves of non-exposed plants, more lesions were induced than on leaves of other non-exposed plants inoculated with conidia suspended in dew collected from plants which had not been exposed to ozone. EDU protected onion leaves from ozone-induced predisposition to these fungi under controlled conditions. Experiments designed to detect interaction between B. cinerea and B. squamosa in onion leaf blighting indicated that such interaction did not occur. Leaves were blighted rapidly when inoculated with B. squamosa whether B. cinerea was present or absent.

  11. Field bioassay of Metarhizium anisopliae strains to control the poultry red mite Dermanyssus gallinae.

    PubMed

    Tavassoli, M; Allymehr, M; Pourseyed, S H; Ownag, A; Bernousi, I; Mardani, K; Ghorbanzadegan, M; Shokrpoor, S

    2011-06-10

    The poultry red mite, Dermanyssus gallinae is one of the most economically deleterious ectoparasite of laying hens worldwide. To evaluate the efficacy of three strains (V245, 3247 and 715C) of entomopathogenic fungus Metarhizium anisopliae with potential as acaricides against D. gallinae, this investigation was carried out in a commercial caged laying poultry farm in Naghedeh, West Azarbaijan of Iran. The parasite infestation already existed in the farm. Sunflower oil suspension of all fungal strains, each in two concentrations (1×10(7) and 1×10(9) conidia/ml) were used separately as spray on hens and cages, and in the control group the cages were only sprayed with sunflower oil and sterile distilled water. For estimating the population rate of mites before and after treatment, special cardboard traps were fixed to cages during a 1-month period. The traps were placed on weeks -1, 0, 1, 2 and 3 and always removed after 1 w. The results showed that the population rates post fungal treatment with the lower concentration were not significantly different compared to the control group. However, the reduction in mite numbers induced by all three strains at the concentration of 1×10(9) conidia/ml was significantly higher than the control (P<0.05). The results revealed that under field conditions, higher concentrations of M. anisopliae will be required for controlling D. gallinae.

  12. Biocontrol of pigeon tick Argas reflexus (Acari: Argasidae) by entomopathogenic fungus Metarhizium Anisopliae (Ascomycota: Hypocreales)

    PubMed Central

    Tavassoli, Mosa; Pourseyed, Seyed Hassan; Ownagh, Abdulghaffar; Bernousi, Iraj; Mardani, Karim

    2011-01-01

    The pigeon tick Argas reflexus is a pathogen-transmitting soft tick that typically feeds on pigeons, but can also attack humans causing local and systemic reactions. Chemical control is made difficult due to environmental contamination and resistance development. As a result, there is much interest in increasing the role of other strategies like biological control. In this study, the efficacy of three strains (V245, 685 and 715C) of entomopathogenic fungus Metarhizium anisopliae for biological control of three life stages of pigeon tick A. reflexus including eggs, larvae, engorged and unfed adults was investigated under laboratory conditions. Five concentrations of different strains of M. anisopliae ranging from 103 to 107 conidia/ml were used. All fungal strains significantly decreased hatchability of A. reflexus eggs. Strain V245 was the most effective strain on the mortality of larval stage with nearly 100% mortality at the lowest concentration (103 conidia/ml) at 10 days post-inoculation. The mortality rate of both engorged and unfed adult ticks were also increased significantly exposed to different conidial concentrations compared to the control groups (P < 0.05) making this fungus a potential biological control agent of pigeon tick reducing the use of chemical acaricides. PMID:24031777

  13. Use of Random T-DNA Mutagenesis in Identification of Gene UvPRO1, A Regulator of Conidiation, Stress Response, and Virulence in Ustilaginoidea virens

    PubMed Central

    Lv, Bo; Zheng, Lu; Liu, Hao; Tang, Jintian; Hsiang, Tom; Huang, Jinbin

    2016-01-01

    False smut of rice, caused by Ustilaginoidea virens (Cooke) Takahashi (teleomorph: Villosiclava virens), is one of the most important diseases affecting rice worldwide. Agrobacterium tumefaciens-mediated transformation was used to identify functional genes in U. virens. In this study, we selected a single-copy insertion mutant T133 with deficiency in producing conidia by screening the T-DNA insertion mutant library of U. virens. The UvPRO1-deletion mutant was successfully obtained after cloning the targeted gene by analysis of the T-DNA insert site of mutant T133. Further research showed that the UvPRO1 mutant was reduced in growth rate and could not produce conidia in PSB medium, while sensitivities to sodium dodecyl sulfate, Congo red, and hyperosmotic stress increased. Moreover, the UvPRO1 deletion mutant hyphae could extend along the surface of spikelets at 1–3 dpi, but mycelia became shriveled and completely lost the ability to infect spikelets at 4 dpi. The relative expression level of UvPRO1 at 8 dpi was more than twice as high as that at 1–2 dpi. These results suggest that UvPRO1 plays a critical role in hyphal growth and conidiation, as well as in stress response and pathogenesis. These findings provide a novel mode of action for the PRO1 protein in fungi and improve the understanding of the function of UvPRO1 in the life cycle of U. virens. PMID:28082958

  14. Method To Enhance Growth and Sporulation of Pelletized Biocontrol Fungi †

    PubMed Central

    Knudsen, G. R.; Eschen, D. J.; Dandurand, L. M.; Wang, Z. G.

    1991-01-01

    The biocontrol fungi Trichoderma harzianum, used to control soilborne plant pathogens, and Beauveria bassiana, used to control insect pests, were formulated as mycelial biomass in alginate pellets with wheat bran added. After drying for 0, 4, or 16 h, pellets were placed in water or in aqueous solutions of polyethylene glycol (PEG) 8000 for 4 to 24 h and then allowed to continue drying. PEG-treated pellets containing T. harzianum showed significantly greater proliferation of hyphae in soil than untreated pellets or pellets treated with water. Production of conidia of T. harzianum from PEG-treated pellets was lower than production from untreated pellets after 4 days, although rates were equivalent after 7 days. In contrast, production of conidia of B. bassiana was significantly more rapid from PEG-treated pellets than from untreated pellets. Biocontrol of soilborne plant pathogens or insect pests may be enhanced by rapid hyphal growth of T. harzianum in soil or rapid sporulation of B. bassiana on foliage, respectively. Therefore, PEG treatment may improve the efficacy of these biocontrol agents. PMID:16348562

  15. Acute invasive pulmonary aspergillosis, shortly after occupational exposure to polluted muddy water, in a previously healthy subject

    PubMed Central

    Pilaniya, Vikas; Gera, Kamal; Gothi, Rajesh; Shah, Ashok

    2015-01-01

    Invasive pulmonary aspergillosis (IPA) predominantly occurs in severely neutropenic immunocompromised subjects. The occurrence of acute IPA after brief but massive exposure to Aspergillus conidia in previously healthy subjects has been documented, although only six such cases have been reported. The diagnosis was delayed in all six of the affected patients, five of whom died. We report the case of a 50-year-old HIV-negative male, a water pipeline maintenance worker, who presented with acute-onset dyspnea and fever one day after working for 2 h in a deep pit containing polluted, muddy water. Over a one-month period, his general condition deteriorated markedly, despite antibiotic therapy. Imaging showed bilateral diffuse nodules with cavitation, some of which were surrounded by ground-glass opacity suggestive of a halo sign (a hallmark of IPA). Cultures (of sputum/bronchial aspirate samples) and serology were positive for Aspergillus fumigatus. After being started on itraconazole, the patient improved. We conclude that massive exposure to Aspergillus conidia can lead to acute IPA in immunocompetent subjects. PMID:26578140

  16. Mutation of AREA affects growth, sporulation, nitrogen regulation, and pathogenicity in Colletotrichum gloeosporioides.

    PubMed

    Bi, Fangcheng; Ment, Dana; Luria, Neta; Meng, Xiangchun; Prusky, Dov

    2017-02-01

    The GATA transcription factor AreA is a global nitrogen regulator that restricts the utilization of complex and poor nitrogen sources in the presence of good nitrogen sources in microorganisms. In this study, we report the biological function of an AreA homolog (the CgareA gene) in the fruit postharvest pathogen Colletotrichum gloeosporioides. Targeted gene deletion mutants of areA exhibited significant reductions in vegetative growth, increases in conidia production, and slight decreases in conidial germination rates. Quantitative RT-PCR (qRT-PCR) analysis revealed that the expression of AreA was highly induced under nitrogen-limiting conditions. Moreover, compared to wild-type and complemented strains, nitrogen metabolism-related genes were misregulated in ΔareA mutant strains. Pathogenicity assays indicated that the virulence of ΔareA mutant strains were affected by the nitrogen content, but not the carbon content, of fruit hosts. Taken together, our results indicate that CgareA plays a critical role in fungal development, conidia production, regulation of nitrogen metabolism and virulence in Colletotrichum gloeosporioides.

  17. Fungal Antagonism Assessment of Predatory Species and Producers Metabolites and Their Effectiveness on Haemonchus contortus Infective Larvae

    PubMed Central

    Silva, Manoel Eduardo; Braga, Fabio Ribeiro; de Gives, Pedro Mendoza; Millán-Orozco, Jair; Uriostegui, Miguel Angel Mercado; Marcelino, Liliana Aguilar; Soares, Filippe Elias de Freitas; Araújo, Andréia Luiza; Vargas, Thainá Souza; Aguiar, Anderson Rocha; Senna, Thiago; Rodrigues, Maria Gorete; Froes, Frederico Vieira; de Araújo, Jackson Victor

    2015-01-01

    The objective of this study was to assess antagonism of nematophagous fungi and species producers metabolites and their effectiveness on Haemonchus contortus infective larvae (L3). Assay A assesses the synergistic, additive, or antagonistic effect on the production of spores of fungal isolates of the species Duddingtonia flagrans, Clonostachys rosea, Trichoderma esau, and Arthrobotrys musiformis; Assay B evaluates in vitro the effect of intercropping of these isolates grown in 2% water-agar (2% WA) on L3 of H. contortus. D. flagrans (Assay A) produced 5.3 × 106 spores and associated with T. esau, A. musiformis, or C. rosea reduced its production by 60.37, 45.28, and 49.05%, respectively. T. esau produced 7.9 × 107 conidia and associated with D. flagrans, A. musiformis, or C. rosea reduced its production by 39.24, 82.27, and 96.96%, respectively. A. musiformis produced 7.3 × 109 spores and associated with D. flagrans, T. esau, or C. rosea reduced its production by 99.98, 99.99, and 99.98%, respectively. C. rosea produced 7.3 × 108 conidia and associated with D. flagrans, T. esau, or A. musiformis reduced its production by 95.20, 96.84, and 93.56%, respectively. These results show evidence of antagonism in the production of spores between predators fungi. PMID:26504791

  18. Autophagy-associated alpha-arrestin signaling is required for conidiogenous cell development in Magnaporthe oryzae

    PubMed Central

    Dong, Bo; Xu, Xiaojin; Chen, Guoqing; Zhang, Dandan; Tang, Mingzhi; Xu, Fei; Liu, Xiaohong; Wang, Hua; Zhou, Bo

    2016-01-01

    Conidiation patterning is evolutionarily complex and mechanism concerning conidiogenous cell differentiation remains largely unknown. Magnaporthe oryzae conidiates in a sympodial way and uses its conidia to infect host and disseminate blast disease. Arrestins are multifunctional proteins that modulate receptor down-regulation and scaffold components of intracellular trafficking routes. We here report an alpha-arrestin that regulates patterns of conidiation and contributes to pathogenicity in M. oryzae. We show that disruption of ARRDC1 generates mutants which produce conidia in an acropetal array and ARRDC1 significantly affects expression profile of CCA1, a virulence-related transcription factor required for conidiogenous cell differentiation. Although germ tubes normally develop appressoria, penetration peg formation is dramatically impaired and Δarrdc1 mutants are mostly nonpathogenic. Fluorescent analysis indicates that EGFP-ARRDC1 puncta are well colocalized with DsRed2-Atg8, and this distribution profile could not be altered in Δatg9 mutants, suggesting ARRDC1 enters into autophagic flux before autophagosome maturation. We propose that M. oryzae employs ARRDC1 to regulate specific receptors in response to conidiation-related signals for conidiogenous cell differentiation and utilize autophagosomes for desensitization of conidiogenous receptor, which transmits extracellular signal to the downstream elements of transcription factors. Our investigation extends novel significance of autophagy-associated alpha-arrestin signaling to fungal parasites. PMID:27498554

  19. Genetic control of asexual development in aspergillus fumigatus.

    PubMed

    Alkhayyat, Fahad; Chang Kim, Sun; Yu, Jae-Hyuk

    2015-01-01

    Aspergillus fumigatus is one of the most common fungi found in the environment. It is an opportunistic human pathogen causing invasive pulmonary aspergillosis with a high mortality rate in immunocompromised patients. Conidia, the asexual spores, serve as the main dispersal and infection agent allowing entrance of the fungus into the host through the respiratory tract. Therefore, understanding the asexual developmental process that gives rise to the conidia is of great interest to the scientific community and is currently the focus of an immense load of research being conducted. We have been studying the genetic basis that controls asexual development and gliotoxin biosynthesis in A. fumigatus. In this review, we discuss the genetic regulatory system that dictates conidiation in this important fungus by covering the roles of crucial genetic factors from the upstream heterotrimeric G-protein signaling components to the more specific downstream central activators of the conidiation pathway. In addition, other key asexual regulators including the velvet regulators, the Flb proteins and their associated regulatory factors are discussed.

  20. The rise and fall of Sarawakus (Hypocreaceae, Ascomycota)

    PubMed Central

    Jaklitsch, Walter M.; Lechat, Christian; Voglmayr, Hermann

    2014-01-01

    Species of Sarawakus are rarely encountered. Their teleomorphs resemble sexual stages of Trichoderma, formerly called Hypocrea, but differ from that genus by unicellular ascospores. The two greenspored species S. britannicus and the type species of Sarawakus, S. lycogaloides, recently were collected, compared with their types and cultured. We redescribe and illustrate these species and transfer them to Trichoderma, based on phylogenetic analysis of the translation elongation factor 1-alpha encoding gene (tef1), containing the two last introns and exon, and a part of the rpb2 gene, encoding the second largest RNA polymerase subunit. Trichoderma lycogaloides, was found to cluster with Hypocrea sulawesensis, an unusual species of Trichoderma, while T. britannicum is closely related to T. aerugineum of the Spinulosa clade. The anamorphs of the two examined species are characterized by (odd) verticillium-like conidiophores, large cylindrical phialides and conidia, which belong to the largest of those species forming green conidia, oval to subglobose in T. lycogaloides and oblong in T. britannicum. All species currently recognized in Sarawakus are transferred to Trichoderma, introducing the new combinations T. fragile, T. hexasporum, T. izawae, T. sordidum, T. subtrachycarpum, T. succisum and T. trachycarpum and the new name T. rosellum. Trichoderma trachycarpum is redescribed and illustrated from an isotype. PMID:24603837

  1. Vermamoeba vermiformis-Aspergillus fumigatus relationships and comparison with other phagocytic cells.

    PubMed

    Maisonneuve, Elodie; Cateau, Estelle; Kaaki, Sihem; Rodier, Marie-Hélène

    2016-11-01

    Free living amoebae (FLA) are protists ubiquitously present in the environment. Aspergillus fumigatus is a mould responsible for severe deep-seated infections, and that can be recovered in the same habitats as the FLA. By conducting coculture experiments and fungal incubation with amoebal supernatants, we report herein that Vermamoeba vermiformis, a FLA present in hospital water systems, promotes filamentation and growth of A. fumigatus. This finding is of particular importance to institutions whose water systems might harbor FLA and could potentially be used by immunocompromised patients. Also, the relationships between V. vermiformis and A. fumigatus were compared to those between this fungus and two other phagocytic cells: Acanthamoeba castellanii, another FLA, and macrophage-like THP-1 cells. After 4 h of coincubation, the percentages of the three phagocytic cell types with adhered conidia were similar, even though the types of receptors between FLA and macrophagic cell seemed different. However, the percentage of THP-1 with internalized conidia was considerably lower (40 %) in comparison with the two other cell types (100 %). Thus, this study revealed that interactions between A. fumigatus and these three phagocytic cell types show similarities, even though it is premature to extrapolate these results to interpret relationships between A. fumigatus and macrophages.

  2. Gliotoxin promotes Aspergillus fumigatus internalization into type II human pneumocyte A549 cells by inducing host phospholipase D activation.

    PubMed

    Jia, Xiaodong; Chen, Fangyan; Pan, Weihua; Yu, Rentao; Tian, Shuguang; Han, Gaige; Fang, Haiqin; Wang, Shuo; Zhao, Jingya; Li, Xianping; Zheng, Dongyu; Tao, Sha; Liao, Wanqing; Han, Xuelin; Han, Li

    2014-06-01

    The internalization of Aspergillus fumigatus into lung epithelial cells is critical for the infection process in the host. Gliotoxin is the most potent toxin produced by A. fumigatus. However, its role in A. fumigatus internalization into the lung epithelial cells is still largely unknown. In the present study, the deletion of the gliP gene regulating the production of gliotoxin in A. fumigatus suppressed the internalization of conidia into the A549 lung epithelial cells, and this suppression could be rescued by the exogenous addition of gliotoxin. At lower concentrations, gliotoxin enhanced the internalization of the conidia of A. fumigatus into A549 cells; in contrast, it inhibited the phagocytosis of J774 macrophages in a dose-dependent manner. Under a concentration of 100 ng/ml, gliotoxin had no effect on A549 cell viability but attenuated ROS production in a dose-dependent manner. Gliotoxin significantly stimulated the phospholipase D activity in the A549 cells at a concentration of 50 ng/ml. This stimulation was blocked by the pretreatment of host cells with PLD1- but not PLD2-specific inhibitor. Morphological cell changes induced by gliotoxin were observed in the A549 cells accompanying with obvious actin cytoskeleton rearrangement and a moderate alteration of phospholipase D distribution. Our data indicated that gliotoxin might be responsible for modulating the A. fumigatus internalization into epithelial cells through phospholipase D1 activation and actin cytoskeleton rearrangement.

  3. Seven wood-inhabiting new species of the genus Trichoderma (Fungi, Ascomycota) in Viride clade

    PubMed Central

    Qin, Wen-Tao; Zhuang, Wen-Ying

    2016-01-01

    More than 200 recent collections of Trichoderma from China were examined and 16 species belonging to the Viride clade were identified based on integrated studies of phenotypic and molecular data. Among them, seven wood-inhabiting new species, T. albofulvopsis, T. densum, T. laevisporum, T. sinokoningii, T. sparsum, T. sphaerosporum and T. subviride, are found. They form trichoderma- to verticillium-like conidiophores, lageniform to subulate phialides and globose to ellipsoidal conidia, but vary greatly in colony features, growth rates, and sizes of phialides and conidia. To explore their taxonomic positions, the phylogenetic tree including all the known species of the Viride clade is constructed based on sequence analyses of the combined RNA polymerase II subunit b and translation elongation factor 1 alpha exon genes. Our results indicated that the seven new species were well-located in the Koningii, Rogersonii and Neorufum subclades as well as a few independent terminal branches. They are clearly distinguishable from any existing species. Morphological distinctions and sequence divergences between the new species and their close relatives were discussed. PMID:27245694

  4. UVA Photoactivation of Harmol Enhances Its Antifungal Activity against the Phytopathogens Penicillium digitatum and Botrytis cinerea.

    PubMed

    Olmedo, Gabriela M; Cerioni, Luciana; González, María M; Cabrerizo, Franco M; Volentini, Sabrina I; Rapisarda, Viviana A

    2017-01-01

    Phytopathogenic fungi responsible for post-harvest diseases on fruit and vegetables cause important economic losses. We have previously reported that harmol (1-methyl-9H-pyrido[3,4-b]indol-7-ol) is active against the causal agents of green and gray molds Penicillium digitatum and Botrytis cinerea, respectively. Here, antifungal activity of harmol was characterized in terms of pH dependency and conidial targets; also photodynamic effects of UVA irradiation on the antimicrobial action were evaluated. Harmol was able to inhibit the growth of both post-harvest fungal disease agents only in acidic conditions (pH 5), when it was found in its protonated form. Conidia treated with harmol exhibited membrane integrity loss, cell wall disruption, and cytoplasm disorganization. All these deleterious effects were more evident for B. cinerea in comparison to P. digitatum. When conidial suspensions were irradiated with UVA in the presence of harmol, antimicrobial activity against both pathogens was enhanced, compared to non-irradiated conditions. B. cinerea exhibited a high intracellular production of reactive oxygen species (ROS) when was incubated with harmol in irradiated and non-irradiated treatments. P. digitatum showed a significant increase in ROS accumulation only when treated with photoexcited harmol. The present work contributes to unravel the antifungal activity of harmol and its photoexcited counterpart against phytopathogenic conidia, focusing on ROS accumulation which could account for damage on different cellular targets.

  5. Aspergillus fumigatus melanins: interference with the host endocytosis pathway and impact on virulence

    PubMed Central

    Heinekamp, Thorsten; Thywißen, Andreas; Macheleidt, Juliane; Keller, Sophia; Valiante, Vito; Brakhage, Axel A.

    2013-01-01

    The opportunistic human pathogenic fungus Aspergillus fumigatus produces at least two types of melanin, namely pyomelanin and dihydroxynaphthalene (DHN) melanin. Pyomelanin is produced during tyrosine catabolism via accumulation of homogentisic acid. Although pyomelanin protects the fungus against reactive oxygen species (ROS) and acts as a defense compound in response to cell wall stress, mutants deficient for pyomelanin biosynthesis do not differ in virulence when tested in a murine infection model for invasive pulmonary aspergillosis. DHN melanin is responsible for the characteristic gray-greenish color of A. fumigatus conidia. Mutants lacking a functional polyketide synthase PksP, the enzyme responsible for the initial step in DHN-melanin formation, i.e., the synthesis of naphthopyrone, produce white spores and are attenuated in virulence. The activity of PksP was found to be essential not only for inhibition of apoptosis of phagocytes by interfering with the host PI3K/Akt signaling cascade but also for effective inhibition of acidification of conidia-containing phagolysosomes. These features allow A. fumigatus to survive in phagocytes and thereby to escape from human immune effector cells and to become a successful pathogen. PMID:23346079

  6. Life and the outer planets I. Performance of terrestrial organisms in ammonia-rich systems.

    PubMed

    Siegel, S M

    1977-01-01

    Survival and growth of organisms has been demonstrated at 298 degrees K in NH3 atmospheres, including ammonia-methane mixtures. Included are bacteria such as Clostridium perfringens, Pseudomonas aeruginosa, fungi such as Penicillium notatum and Torula utilis. Although the biological response in onion and other species of Allium is limited to germination, standard metabolic poisons were active even in 15 M aqueous NH3, at 250 degrees K. The most extreme example of compatibility between NH3-rich environments and terrestrial life was the retention of metabolic capabilities by conidia of Penicillium after 6 months at 233 degrees K in a liquid ammonia-glycerol medium. Tritiated thymidine, uridine and amino acids were incorporated by these conidia unless subjected to intense gamma-radiation. Observations spanning the past decade suggest that the analogies between H2O and NH3 as solvent media or -OH and -NH2, as functional groups are probably valid. Chemical-biological evolution similar to early terrestrial evolution could be compatible with chemical conditions presumed to exist on the outer planets and some of their satellites.

  7. Entomopathogenicity of Simplicillium lanosoniveum Isolated in Korea

    PubMed Central

    Lim, Sung Yeol; Lee, Sehee; Kong, Hyun Gi

    2014-01-01

    Fruiting bodies similar to those of the ascomycete fungi Podostroma cornu-damae and Cordyceps militaris were collected from Mt. Seunghak in Busan, Korea on August 21, 2012. The fruiting bodies were cylindrical, with tapered ends and golden red in color. The fruiting bodies contained abundant conidiophores bearing single-celled conidia, but no perithecia or asci. Pure culture of the fungal isolates was obtained through single-spore isolation. Analyses of morphological characteristics, including conidia shape, and phylogenetic traits, using internal transcribed spacer sequences, showed that these isolates belonged to the species Simplicillium lanosoniveum. Although this fungal species is known to be mycoparasitic, the isolates obtained in this study were unable to infect fungi. However, silkworms (Bombyx mori) inoculated with the fungal isolates died during the larval or pupal stages, as has been shown for the strongly entomopathogenic fungus Beauveria bassiana. This study is the first report of the entomopathogenicity of S. lanosoniveum and indicates its potential for use in biological control of insects. PMID:25606002

  8. Comparative study of antimicrobial peptides to control citrus postharvest decay caused by Penicillium digitatum.

    PubMed

    Muñoz, Alberto; López-García, Belén; Marcos, Jose F

    2007-10-03

    The objective of this study was to investigate and compare the in vitro efficacy and in vivo potential of eight distinct short antimicrobial peptides to control the postharvest green mold disease of oranges caused by the fungus Penicillium digitatum. The L-amino acid versions of the four peptides PAF26, PAF38, PAF40, and BM0, previously obtained by combinatorial approaches, were examined. The study included two antibacterial peptides formerly identified by rational design, BP15 and BP76, and it is demonstrated that they also have in vitro antifungal properties. The natural antimicrobial peptides melittin and indolicidin were also selected for comparison, due to their well-known properties and modes of action. In vitro and in vivo results indicated differential behaviors among peptides, regarding the inhibitory potency in growth media, selectivity against distinct microorganisms, fungicidal activity towards nongerminated conidia of P. digitatum, and efficacy in fruit inoculation assays. Interestingly, a high in vitro inhibitory activity did not necessarily associate with an effective control of fruit infection by P. digitatum. The short tryptophan-rich cationic peptides PAF26, PAF38, PAF40, and BM0 were lethal to conidia of P. digitatum, and this property is correlated with better protection in the decay control test.

  9. Two new hyaline-ascospored species of Trichoderma and their phylogenetic positions.

    PubMed

    Qin, W T; Zhuang, W Y

    2016-01-01

    Collections of hypocrealean fungi found on decaying wood in subtropical regions of China were examined. Two new species, Trichoderma confluens and T. hubeiense, were discovered and are described. Trichoderma confluens is characterized by its widely effuse to rarely pulvinate, yellow stromata with densely disposed yellowish brown ostioles, simple acremonium- to verticillium-like conidiophores, hyaline conidia and multiform chlamydospores. Trichoderma hubeiense has pulvinate, grayish yellow stromata with brownish ostioles, trichoderma- to verticillium-like conidiophores and hyaline conidia. The phylogenetic positions of the two fungi were investigated based on sequence analyses of RNA polymerase II subunit b and translation elongation factor 1-α genes. The results indicate that T. confluens belongs to the Hypocreanum clade and is associated with but clearly separated from T. applanatum and T. decipiens. Trichoderma hubeiense belongs to the Polysporum clade and related to T. bavaricum but obviously differs from other members of the clade in sequence data. Morphological distinctions between the new species and their close relatives are noted and discussed.

  10. Three new species of Trichoderma with hyaline ascospores from China.

    PubMed

    Zhu, Z X; Zhuang, W Y

    2015-01-01

    Collections of Trichoderma having hyaline ascospores from different areas of China were examined. Using combined analyses of morphological data, culture characters and phylogenetic information based on rDNA sequences of partial nuc translation elongation factor 1-α encoding gene (TEF1-α) and the gene encoding the second largest nuc RNA polymerase subunit (RPB2), three new species, Trichoderma applanatum, T. oligosporum and T. sinoluteum, were discovered and are described. Trichoderma applanatum produces continuous flat to pulvinate, white to cream stromata with dense orange or pale brown ostioles, and simple acremonium-like to verticillium-like conidiophores, belongs to the Hypocreanum clade and is closely related to T. decipiens. Trichoderma oligosporum forms reddish brown stromata with a downy surface, hyaline conidia and gliocladium-like conidiophores, and is closely related to but distinct from T. crystalligenum in the Psychrophila clade. Trichoderma sinoluteum, as a member of the Polysporum clade, is characterized by pale yellow stromata, white pustulate conidiomata, pachybasium-like conidiophores, and hyaline conidia. Differences between the new species and their close relatives are discussed.

  11. Rapid assessment of antimould efficacies of pressure-treated southern pine.

    PubMed

    Price, D; Drago, G; Noble, J; Simmons, R; Crow, S; Ahearn, D

    2002-12-01

    A membrane-screening method was developed in conjunction with flow cytometric (FC) analysis for determining the efficacies of antimould pressure-treatment formulations for mould species of cosmetic significance on southern pine. Fusarium subglutinans, Aspergillus flavus, Penicillium chrysogenum, and Paecilomyces spp. were the predominant moulds colonizing surfaces of the variously treated pine stored in sealed plastic bags over 3- to 6-month periods. Nylon membranes placed directly on pressure-treated pine and membranes saturated with the various formulations were inoculated with the conidia of selected moulds. FC analysis of conidia stained with propidium iodide (PI) before and after exposure to the pressure-treatment formulations permitted a rapid assessment of the inocula and selection of those pressure-treatment formulations with probable inhibitory activity versus probable nonactive preparations. Recoveries of the fungi from the membranes over 9-14 days were in general agreement with the emergence of colonizing fungi on the similarly preserved uninoculated pine stored in sealed plastic bags for 6 months. This combination of procedures provided for a relatively rapid assessment of preservative formulations designed to provide enhanced efficacy against surface mould growth on lumber during storage and retail display.

  12. A Critical Role for CLSP2 in the Modulation of Antifungal Immune Response in Mosquitoes.

    PubMed

    Wang, Yan-Hong; Hu, Yang; Xing, Long-Sheng; Jiang, Hong; Hu, Song-Nian; Raikhel, Alexander S; Zou, Zhen

    2015-06-01

    Entomopathogenic fungi represent a promising class of bio-insecticides for mosquito control. Thus, detailed knowledge of the molecular mechanisms governing anti-fungal immune response in mosquitoes is essential. In this study, we show that CLSP2 is a modulator of immune responses during anti-fungal infection in the mosquito Aedes aegypti. With a fungal infection, the expression of the CLSP2 gene is elevated. CLSP2 is cleaved upon challenge with Beauveria bassiana conidia, and the liberated CLSP2 CTL-type domain binds to fungal cell components and B. bassiana conidia. Furthermore, CLPS2 RNA interference silencing significantly increases the resistance to the fungal challenge. RNA-sequencing transcriptome analysis showed that the majority of immune genes were highly upregulated in the CLSP2-depleted mosquitoes infected with the fungus. The up-regulated immune gene cohorts belong to melanization and Toll pathways, but not to the IMD or JAK-STAT. A thioester-containing protein (TEP22), a member of α2-macroglobulin family, has been implicated in the CLSP2-modulated mosquito antifungal defense. Our study has contributed to a greater understanding of immune-modulating mechanisms in mosquitoes.

  13. Modeling Spatial Characteristics in the Biological Control of Fungi at Leaf Scale: Competitive Substrate Colonization by Botrytis cinerea and the Saprophytic Antagonist Ulocladium atrum.

    PubMed

    Kessel, G J T; Köhl, J; Powell, J A; Rabbinge, R; van der Werf, W

    2005-04-01

    ABSTRACT A spatially explicit model describing saprophytic colonization of dead cyclamen leaf tissue by the plant-pathogenic fungus Botrytis cinerea and the saprophytic fungal antagonist Ulocladium atrum was constructed. Both fungi explore the leaf and utilize the resources it provides. Leaf tissue is represented by a two-dimensional grid of square grid cells. Fungal competition within grid cells is modeled using Lotka-Volterra equations. Spatial expansion into neighboring grid cells is assumed proportional to the mycelial density gradient between donor and receptor cell. Established fungal biomass is immobile. Radial growth rates of B. cinerea and U. atrum in dead cyclamen leaf tissue were measured to determine parameters describing the spatial dynamics of the fungi. At temperatures from 5 to 25 degrees C, B. cinerea colonies expanded twice as rapidly as U. atrum colonies. In practical biological control, the slower colonization of space by U. atrum thus needs to be compensated by a sufficiently dense and even distribution of conidia on the leaf. Simulation results confirm the importance of spatial expansion to the outcome of the competitive interaction between B. cinerea and U. atrum at leaf scale. A sensitivity analysis further emphasized the importance of a uniform high density cover of vital U. atrum conidia on target leaves.

  14. Evaluation of Antifungal Activity and Mode of Action of New Coumarin Derivative, 7-Hydroxy-6-nitro-2H-1-benzopyran-2-one, against Aspergillus spp.

    PubMed Central

    Guerra, Felipe Queiroga Sarmento; de Araújo, Rodrigo Santos Aquino; de Sousa, Janiere Pereira; Pereira, Fillipe de Oliveira; Mendonça-Junior, Francisco J. B.; Barbosa-Filho, José M.; de Oliveira Lima, Edeltrudes

    2015-01-01

    Aspergillus spp. produce a wide variety of diseases. For the treatment of such infections, the azoles and Amphotericin B are used in various formulations. The treatment of fungal diseases is often ineffective, because of increases in azole resistance and their several associated adverse effects. To overcome these problems, natural products and their derivatives are interesting alternatives. The aim of this study was to examine the effects of coumarin derivative, 7-hydroxy-6-nitro-2H-1-benzopyran-2-one (Cou-NO2), both alone and with antifungal drugs. Its mode of action against Aspergillus spp. Cou-NO2 was tested to evaluate its effects on mycelia growth and germination of fungal conidia of Aspergillus spp. We also investigated possible Cou-NO2 action on cell walls (0.8 M sorbitol) and on Cou-NO2 to ergosterol binding in the cell membrane. The study shows that Cou-NO2 is capable of inhibiting both the mycelia growth and germination of conidia for the species tested, and that its action affects the structure of the fungal cell wall. At subinhibitory concentration, Cou-NO2 enhanced the in vitro effects of azoles. Moreover, in combination with azoles (voriconazole and itraconazole) Cou-NO2 displays an additive effect. Thus, our study supports the use of coumarin derivative 7-hydroxy-6-nitro-2H-1-benzopyran-2-one as an antifungal agent against Aspergillus species. PMID:26175794

  15. Modification of competence for in vitro response to Fusarium oxysporum in tomato cells. II. Effect of the integration of Agrobacterium tumefaciens genes for auxin and cytokinin synthesis.

    PubMed

    Storti, E; Bogani, P; Bettini, P; Bittini, P; Guardiola, M L; Pellegrini, M G; Inzé, D; Buiatti, M

    1994-04-01

    We have studied the effect of a change in the endogenous hormone equilibria on the competence of tomato (Lycopersicon esculentum) cells to defend themselves against the fungal pathogen Fusarium oxysporum f. sp. lycopersici. Calluses from cvs 'Davis' and 'Red River', respectively resistant and susceptible to Fusarium and transgenic for an auxin- or cytokinin-synthesizing gene from Agrobacterium tumefaciens, were used. The integration of Agrobacterium hormone-related genes into susceptible cv 'Red River' can bring the activation of defense processes to a stable competence as assessed by the inhibition of mycelial growth in dual culture and gem-tube elongation of Fusarium conidia, the determination of callose contents, peroxidase induction and ion leakage in the presence of fusaric acid. This is particularly true when the transformation results in a change of phytohormone equilibria towards an higher cytokin in concentration. On the contrary, in resistant cv 'Davis' the inhibition of both fungal growth in dual culture and conidia germination is higher when the hormone balance is modified in favour of the auxins. No significant effect was observed for ion leakage and peroxidase induction, probably because of a constitutive overproduction of cytokinins in 'Davis' cells.

  16. Morphological and physiological comparison of taxa comprising the Sporothrix schenckii complex.

    PubMed

    Zhao, Ming-dan; Zhou, Xun; Liu, Ting-ting; Yang, Zhi-bang

    2015-11-01

    Based on recent molecular data, it has been suggested that Sporothrix globosa is the main causal agent of sporotrichosis in China. The objective of this study was to compare the morphology, growth characteristics, patterns of carbon source usage, and susceptibility to antifungal agents among Sporothrix strains. A total of 15 clinical strains confirmed to be S. globosa, from three different regions of China, and 11 ex-type strains from the CBS-KNAW biodiversity center were obtained. The elongated conidia of S. pallida, S. variecibatus, S. schenckii, and S. schenckii luriei were clearly different from the subglobose and globose conidia of S. globosa strains. S. schenckii is able to assimilate sucrose, raffinose, and ribitol. Susceptibility profiles of these Sporothrix species were evaluated by measuring minimum inhibitory concentrations (MICs). Fluconazole, itraconazole, terbinafine, and amphotericin B showed good activity against most S. globosa clinical isolates from China. Potassium iodide also showed a low MIC against S. pallida, while fluconazole showed a high MIC for S. mexicana, S. humicola, S. globosa, S. schenckii, and S. inflata; these strains might be considered tolerant. The species showed differences in susceptibility to antifungal drugs and should therefore be properly identified during diagnosis prior to designing therapeutic strategies.

  17. Nannizziopsis guarroi infection in 2 Inland Bearded Dragons (Pogona vitticeps): clinical, cytologic, histologic, and ultrastructural aspects.

    PubMed

    Le Donne, Viviana; Crossland, Nicholas; Brandão, João; Sokolova, Yuliya; Fowlkes, Natalie; Nevarez, Javier G; Langohr, Ingeborg M; Gaunt, Stephen D

    2016-06-01

    Chrysosporium-related infections have been increasingly reported in reptiles over the last 2 decades. In this report, we describe clinical, cytologic, histopathologic, and ultrastructural aspects of Chrysosporium-related infection in 2 Inland Bearded Dragons (Pogona vitticeps). Case 1 was presented for an enlarging raised lesion over the left eye and multiple additional masses over the dorsum. Case 2 was submitted to necropsy by the referring veterinarian for suspected yellow fungus disease. Impression smears of the nodules in case 1 revealed granulomatous to pyogranulomatous inflammation and many septate, variably long, 4-10 μm wide, often undulated hyphae, and very rare conidia. Postmortem impression smears of the superficial lesions of case 2 contained large numbers of solitary conidia and arthroconidia and low numbers of hyphae with similar morphology to case 1. Histopathology of the 2 cases revealed severe, multifocal, chronic, ulcerative, nodular pyogranulomatous dermatitis, with myriad intralesional septate hyphae, and arthroconidia. Fungal culture and molecular sequencing in both cases indicated infection with Nannizziopsis guarroi.

  18. Activities of Aureobasidium pullulans cell filtrates against Monilinia laxa of peaches.

    PubMed

    Di Francesco, Alessandra; Roberti, Roberta; Martini, Camilla; Baraldi, Elena; Mari, Marta

    2015-12-01

    The Aureobasidium pullulans L1 and L8 strains are known as efficient biocontrol agents against several postharvest fungal pathogens. In order to better understand the mechanism of action underneath the antifungal activity of L1 and L8 strains, yeast cell filtrates grown at different times were evaluated in vivo against Monilinia laxa on peach. Lesion diameters on peach fruit were reduced by L1 and L8 culture filtrates of 42.5% and 67% respectively. The ability of these filtrates to inhibit M. laxa conidia germination and germ tube elongation was studied by in vitro assays. The results showed a 70% reduction of conidia germination for both strains while for germ tube elongation, it was 52% and 41% for L1 and L8 culture filtrates respectively. Finally, the activity of cell wall hydrolytic enzymes such as chitinase and glucanase in cell filtrates was analysed and the expression of genes encoding these activities was quantified during yeast growth. From 24h onward, both culture filtrates contained β,1-3,glucanase and. chitinase activities, the most pronounced of which was N-β-acetylglucosaminidase. Gene expression level encoding for these enzymes in L1 and L8 varied according to the strain. These results indicate that L1 and L8 strains culture filtrates retain the yeast antagonistic activity and suggest that the production of hydrolytic enzymes plays an important role in this activity.

  19. New species of Cordana and epitypification of the genus.

    PubMed

    Hernández-Restrepo, Margarita; Gené, Josepa; Mena-Portales, Julio; Cano, Jose; Madrid, Hugo; Castañeda-Ruiz, Rafael F; Guarro, Josep

    2014-01-01

    Two interesting fungi belonging to the genus Cordana have been isolated recently in Spain from plant debris. Both are proposed here as new species, described and illustrated. Cordana mercadiana sp. nov. produces 0-1-septate conidia, with a prominent basal scar. Cordana verruculosa sp. nov. differs from the other species of the genus by its unique combination of aseptate, verruculose and small conidia. Both species are compared morphologically with other species of Cordana and their identities supported by the analysis of rDNA sequences. LSU sequence analysis revealed the congeneric relationship of Cordana and Pseudobotrytis; the members of both genera are in a well supported monophyletic lineage that appears to be related to the Coniochaetales but remains incertae sedis within the Sordariomycetes. To establish nomenclatural stability of the genus Cordana, an isolate of C. pauciseptata is designed here as epitype and the two species of Pseudobotrytis are transferred to Cordana. A dichotomous key is provided to identify the currently accepted species of Cordana.

  20. Surface imaging of the filamentous fungus Penicillium simplicissimum growing in a solid-state fermentation system.

    PubMed

    de Almeida, Fernando Pereira; Freire, Denise Maria Guimarães; Lins, Ulysses; Gutarra, Melissa Limoeiro Estrada

    2017-04-05

    A comparative study on the lipase-producing fungus Penicillium simplissicimum, grown on a tray type solid-state fermentation (SSF) bioreactor, was performed using stereoscopy, focus Z-stacking stereoscopic images, field emission scanning electron microscopy (FE-SEM) and environmental scanning electron microscopy (ESEM) to better characterize the morphology of filamentous fungi in SSF and their distribution over the solid matrix. The imaging of live fungal samples using a stereomicroscope with focus Z-stacking showed differences in colonization between a static SSF and an intermittent agitated SSF. A comparison of the stereomicroscopy, hi-vacuum and environmental scanning electron microscopy results obtained using different protocols for sample processing showed that fixation with osmium tetroxide vapor and subsequent hydrated imaging is the best combination of sample preparation and imaging conditions for keeping the arrangement of the aerial hyphae and conidia morphology closer to the natural state. These combined methodologies can be applied in the SSF of fungal growth to characterize the formation of conidiophores over time, the conidia morphology and the spatial organization after their release from conidiophores. Mycelium colonization over the matrix, which is an important characteristic related to the production of different biotechnological products, could be observed and provide more knowledge about fungal physiology behavior during SSF.