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Sample records for airborne alternaria spore

  1. Airborne fungal spores of Alternaria, meteorological parameters and predicting variables

    NASA Astrophysics Data System (ADS)

    Filali Ben Sidel, Farah; Bouziane, Hassan; del Mar Trigo, Maria; El Haskouri, Fatima; Bardei, Fadoua; Redouane, Abdelbari; Kadiri, Mohamed; Riadi, Hassane; Kazzaz, Mohamed

    2015-03-01

    Alternaria is frequently found as airborne fungal spores and is recognized as an important cause of respiratory allergies. The aerobiological monitoring of fungal spores was performed using a Burkard volumetric spore traps. To establish predicting variables for daily and weakly spore counts, a stepwise multiple regression between spore concentrations and independent variables (meteorological parameters and lagged values from the series of spore concentrations: previous day or week concentration (Alt t - 1) and mean concentration of the same day or week in other years ( C mean)) was made with data obtained during 2009-2011. Alternaria conidia are present throughout the year in the atmosphere of Tetouan, although they show important seasonal fluctuations. The highest levels of Alternaria spores were recorded during the spring and summer or autumn. Alternaria showed maximum daily values in April, May or October depending on year. When the spore variables of Alternaria, namely C mean and Alt t - 1, and meteorological parameters were included in the equation, the resulting R 2 satisfactorily predict future concentrations for 55.5 to 81.6 % during the main spore season and the pre-peak 2. In the predictive model using weekly values, the adjusted R 2 varied from 0.655 to 0.676. The Wilcoxon test was used to compare the results from the expected values and the pre-peak spore data or weekly values for 2012, indicating that there were no significant differences between series compared. This test showed the C mean, Alt t - 1, frequency of the wind third quadrant, maximum wind speed and minimum relative humidity as the most efficient independent variables to forecast the overall trend of this spore in the air.

  2. Potential sources of airborne Alternaria spp. spores in South-west Spain.

    PubMed

    Fernández-Rodríguez, Santiago; Sadyś, Magdalena; Smith, Matt; Tormo-Molina, Rafael; Skjøth, Carsten Ambelas; Maya-Manzano, José María; Silva-Palacios, Inmaculada; Gonzalo-Garijo, Ángela

    2015-11-15

    Fungi belonging to the genus of Alternaria are recognised as being significant plant pathogens, and Alternaria allergens are one of the most important causes of respiratory allergic diseases in Europe. This study aims to provide a detailed and original analysis of Alternaria transport dynamics in Badajoz, SW Spain. This was achieved by examining daily mean and hourly observations of airborne Alternaria spores recorded during days with high airborne concentrations of Alternaria spores (>100 s m(-3)) from 2009 to 2011, as well as four inventory maps of major Alternaria habitats, the overall synoptic weather situation and analysis of air mass transport using Hybrid Single Particle Lagrangian Integrated Trajectory model and geographic information systems. Land use calculated within a radius of 100 km from Badajoz shows that crops and grasslands are potentially the most important local sources of airborne Alternaria spores recorded at the site. The results of back trajectory analysis show that, during the examined four episodes, the two main directions where Alternaria source areas were located were: (1) SW-W; and (2) NW-NE. Regional scale and long distance transport could therefore supplement the airborne catch recorded at Badajoz with Alternaria conidia originating from sources such as crops and orchards situated in other parts of the Iberian Peninsula. PMID:26156135

  3. Crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Sommer, J.; Frederiksen, L.; Gosewinkel Karlson, U.

    2012-06-01

    This study tests the hypothesis that Danish agricultural areas are the main source to airborne Alternaria spores in Copenhagen, Denmark. We suggest that the source to the overall load is mainly local, but with intermittent Long Distance Transport (LDT) from more remote agricultural areas. This hypothesis is supported by investigating a 10 yr bi-hourly record of Alternaria spores in the air from Copenhagen. This record shows 232 clinically relevant episodes with a distinct daily profile. The data analysis also revealed potential LDT episodes almost every year. A source map and analysis of atmospheric transport suggest that LDT always originates from the main agricultural areas in Central Europe. A dedicated emission study in cereal crops under harvest during 2010 also supports our hypothesis. The emission study showed that although the fields had been treated against fungal infections, harvesting still produced large amounts of airborne fungal spores. It is likely that such harvesting periods can cause clinically relevant levels of fungal spores in the atmosphere. Our findings suggest that crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen as well as other urban areas in this region. It is likely that such episodes could be simulated using atmospheric transport models.

  4. Crop harvest in Denmark and Central Europe contributes to the local load of airborne Alternaria spore concentrations in Copenhagen

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Sommer, J.; Frederiksen, L.; Gosewinkel Karlson, U.

    2012-11-01

    This study examines the hypothesis that Danish agricultural areas are the main source of airborne Alternaria spores in Copenhagen, Denmark. We suggest that the contribution to the overall load is mainly local or regional, but with intermittent long distance transport (LDT) from more remote agricultural areas. This hypothesis is supported by investigating a 10 yr bi-hourly record of Alternaria spores in the air from Copenhagen. This record shows 232 clinically relevant episodes (daily average spore concentration above 100 m-3) with a distinct daily profile. The data analysis also revealed potential LDT episodes almost every year. A source map and analysis of atmospheric transport suggest that LDT always originates from the main agricultural areas in Central Europe. A dedicated emission study in cereal crops under harvest during 2010 also supports our hypothesis. The emission study showed that although the fields had been treated against fungal infections, harvesting still produced large amounts of airborne fungal spores. It is likely that such harvesting periods can cause clinically relevant levels of fungal spores in the atmosphere. Our findings suggest that crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen as well as other urban areas in this region. It is likely that such episodes could be simulated using atmospheric transport models.

  5. Analysis of the predicting variables for daily and weekly fluctuations of two airborne fungal spores: Alternaria and Cladosporium

    NASA Astrophysics Data System (ADS)

    Recio, Marta; del Mar Trigo, María; Docampo, Silvia; Melgar, Marta; García-Sánchez, José; Bootello, Lourdes; Cabezudo, Baltasar

    2012-11-01

    Alternaria and Cladosporium are two fungal taxa whose spores (conidia) are included frequently in aerobiological studies of outdoor environments. Both spore types are present in the atmosphere of Malaga (Spain) throughout almost the entire year, although they reach their highest concentrations during spring and autumn. To establish predicting variables for daily and weekly fluctuations, Spearman's correlations and stepwise multiple regressions between spore concentrations (measured using a volumetric 7-day recorder) and meteorological variables were made with results obtained for both spore types in 1996 and 1997. Correlations and regressions were also made between the different taxa and their concentrations in different years. Significant and positive correlation coefficients were always obtained between spore concentrations of both taxa, followed by temperature, their concentrations in different years, sunshine hours and relative humidity (this last in a negative sense). For the two spore types we obtained higher correlation and regression coefficients using weekly data. We showed different regression models using weekly values. From the results and a practical point of view, it was concluded that weekly values of the atmospheric concentration of Alternaria spores can be predicted from the maximum temperature expected and its concentrations in the years sampled. As regards the atmospheric concentration of Cladoposrium spores, the weekly values can be predicted based on the concentration of Alternaria spores, thus saving the time and effort that would otherwise be employed in counting them by optical microscopy.

  6. Artificial neural network models of relationships between Alternaria spores and meteorological factors in Szczecin (Poland)

    NASA Astrophysics Data System (ADS)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2008-11-01

    Alternaria is an airborne fungal spore type known to trigger respiratory allergy symptoms in sensitive patients. Aiming to reduce the risk for allergic individuals, we constructed predictive models for the fungal spore circulation in Szczecin, Poland. Monthly forecasting models were developed for the airborne spore concentrations of Alternaria, which is one of the most abundant fungal taxa in the area. Aerobiological sampling was conducted over 2004-2007, using a Lanzoni trap. Simultaneously, the following meteorological parameters were recorded: daily level of precipitation; maximum and average wind speed; relative humidity; and maximum, minimum, average, and dew point temperature. The original factors as well as with lags (up to 3 days) were used as the explaining variables. Due to non-linearity and non-normality of the data set, the modelling technique applied was the artificial neural network (ANN) method. The final model was a split model with classification (spore presence or absence) followed by regression for spore seasons and log(x+1) transformed Alternaria spore concentration. All variables except maximum wind speed and precipitation were important factors in the overall classification model. In the regression model for spore seasons, close relationships were noted between Alternaria spore concentration and average and maximum temperature (on the same day and 3 days previously), humidity (with lag 1) and maximum wind speed 2 days previously. The most important variable was humidity recorded on the same day. Our study illustrates a novel approach to modelling of time series with short spore seasons, and indicates that the ANN method provides the possibility of forecasting Alternaria spore concentration with high accuracy.

  7. Daily variations of Alternaria spores in the city of Murcia (semi-arid southeastern Spain)

    NASA Astrophysics Data System (ADS)

    Munuera Giner, M.; Carrión García, J. S.

    1995-12-01

    Annual variations in the abundance of Alternaria spores were related to the length of the spore period for data from Murcia (southeastern Spain). To understand the relationship between the number of spores and climatic factors, Alternaria spore counts for March 1993 to February 1994 were examined by means of correlation and regression analyses with fourteen different weather parameters. The results indicated that there was a tendency for Alternaria spore concentrations to increase with increases in temperature, wind speed and hours of sunshine. Negative correlations were observed with air pressure, wind direction and humidity. Theoretical curves for Alternaria spore counts are given in relation to temperatures during the period studied.

  8. Changes in concentration of Alternaria and Cladosporium spores during summer storms

    NASA Astrophysics Data System (ADS)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2013-09-01

    Fungal spores are known to cause allergic sensitization. Recent studies reported a strong association between asthma symptoms and thunderstorms that could be explained by an increase in airborne fungal spore concentrations. Just before and during thunderstorms the values of meteorological parameters rapidly change. Therefore, the goal of this study was to create a predictive model for hourly concentrations of atmospheric Alternaria and Cladosporium spores on days with summer storms in Szczecin (Poland) based on meteorological conditions. For this study we have chosen all days of June, July and August (2004-2009) with convective thunderstorms. There were statistically significant relationships between spore concentration and meteorological parameters: positive for air temperature and ozone content while negative for relative humidity. In general, before a thunderstorm, air temperature and ozone concentration increased, which was accompanied by a considerable increase in spore concentration. During and after a storm, relative humidity increased while both air temperature ozone concentration along with spore concentrations decreased. Artificial neural networks (ANN) were used to assess forecasting possibilities. Good performance of ANN models in this study suggest that it is possible to predict spore concentrations from meteorological variables 2 h in advance and, thus, warn people with spore-related asthma symptoms about the increasing abundance of airborne fungi on days with storms.

  9. Changes in concentration of Alternaria and Cladosporium spores during summer storms.

    PubMed

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2013-09-01

    Fungal spores are known to cause allergic sensitization. Recent studies reported a strong association between asthma symptoms and thunderstorms that could be explained by an increase in airborne fungal spore concentrations. Just before and during thunderstorms the values of meteorological parameters rapidly change. Therefore, the goal of this study was to create a predictive model for hourly concentrations of atmospheric Alternaria and Cladosporium spores on days with summer storms in Szczecin (Poland) based on meteorological conditions. For this study we have chosen all days of June, July and August (2004-2009) with convective thunderstorms. There were statistically significant relationships between spore concentration and meteorological parameters: positive for air temperature and ozone content while negative for relative humidity. In general, before a thunderstorm, air temperature and ozone concentration increased, which was accompanied by a considerable increase in spore concentration. During and after a storm, relative humidity increased while both air temperature ozone concentration along with spore concentrations decreased. Artificial neural networks (ANN) were used to assess forecasting possibilities. Good performance of ANN models in this study suggest that it is possible to predict spore concentrations from meteorological variables 2 h in advance and, thus, warn people with spore-related asthma symptoms about the increasing abundance of airborne fungi on days with storms. PMID:23161270

  10. Main airborne Ascomycota spores: characterization by culture, spore morphology, ribosomal DNA sequences and enzymatic analysis.

    PubMed

    Oliveira, Manuela; Amorim, M Isabel; Ferreira, Elsa; Delgado, Luís; Abreu, Ilda

    2010-04-01

    The aim of this work was to identify the main allergy-related Ascomycetes fungal spores present in the atmosphere of Porto, using different and complementary techniques. The atmospheric sampling, performed in the atmosphere of Porto (Portugal) from August 2006 to July 2008, indicated Cladosporium, Penicillium, Aspergillus and Alternaria as the main fungal spore taxa. Alternaria and Cladosporium peaks were registered during summer. Aspergillus and Penicillium highest values were registered from late winter to early spring. Additionally, the Andersen sampler allowed the culture and isolation of the collected viable spores subsequently used for different identification approaches. The internal-transcribed spacer region of the nuclear ribosomal repeat unit sequences of airborne Ascomycetes fungi isolates revealed 11 taxonomically related fungal species. Among the identified taxa, Penicillum and Aspergillus presented the highest diversity, while only one species of Cladosporium and Alternaria, respectively, were identified. All selected fungal spore taxa possessed phosphatase, esterase, leucine arylamidase and beta-glucosidase enzymatic activity, while none had lipase, cystine arylamidase, trypsin or beta-glucuronidase activity. The association between the spore cell wall morphology, DNA-based techniques and enzymatic activity approaches allowed a more reliable identification procedure of the airborne Ascomycota fungal spores. PMID:20143229

  11. Large-spored Alternaria pathogens in section Porri disentangled

    PubMed Central

    Woudenberg, J.H.C.; Truter, M.; Groenewald, J.Z.; Crous, P.W.

    2014-01-01

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e.g. Alternaria porri, A. solani and A. tomatophila). We constructed a multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alt a 1 gene regions, which, supplemented with morphological and cultural studies, forms the basis for species recognition in sect. Porri. Our data reveal 63 species, of which 10 are newly described in sect. Porri, and 27 species names are synonymised. The three known Alternaria pathogens causing early blight on tomato all cluster in one clade, and are synonymised under the older name, A. linariae. Alternaria protenta, a species formerly only known as pathogen on Helianthus annuus, is also reported to cause early blight of potato, together with A. solani and A. grandis. Two clades with isolates causing purple blotch of onion are confirmed as A. allii and A. porri, but the two species cannot adequately be distinguished based on the number of beaks and branches as suggested previously. This is also found among the pathogens of Passifloraceae, which are reduced from four to three species. In addition to the known pathogen of sweet potato, A. bataticola, three more species are delineated of which two are newly described. A new Alternaria section is also described, comprising two large-spored Alternaria species with concatenate conidia. PMID:25492985

  12. Large-spored Alternaria pathogens in section Porri disentangled.

    PubMed

    Woudenberg, J H C; Truter, M; Groenewald, J Z; Crous, P W

    2014-09-01

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e.g. Alternaria porri, A. solani and A. tomatophila). We constructed a multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alt a 1 gene regions, which, supplemented with morphological and cultural studies, forms the basis for species recognition in sect. Porri. Our data reveal 63 species, of which 10 are newly described in sect. Porri, and 27 species names are synonymised. The three known Alternaria pathogens causing early blight on tomato all cluster in one clade, and are synonymised under the older name, A. linariae. Alternaria protenta, a species formerly only known as pathogen on Helianthus annuus, is also reported to cause early blight of potato, together with A. solani and A. grandis. Two clades with isolates causing purple blotch of onion are confirmed as A. allii and A. porri, but the two species cannot adequately be distinguished based on the number of beaks and branches as suggested previously. This is also found among the pathogens of Passifloraceae, which are reduced from four to three species. In addition to the known pathogen of sweet potato, A. bataticola, three more species are delineated of which two are newly described. A new Alternaria section is also described, comprising two large-spored Alternaria species with concatenate conidia. PMID:25492985

  13. Spatial and temporal distribution of Alternaria spores in the Iberian Peninsula atmosphere, and meteorological relationships: 1993-2009

    NASA Astrophysics Data System (ADS)

    Aira, María-Jesús; Rodríguez-Rajo, Francisco-Javier; Fernández-González, María; Seijo, Carmen; Elvira-Rendueles, Belén; Abreu, Ilda; Gutiérrez-Bustillo, Montserrat; Pérez-Sánchez, Elena; Oliveira, Manuela; Recio, Marta; Tormo, Rafael; Morales, Julia

    2013-03-01

    This paper provides an updated of airborne Alternaria spore spatial and temporal distribution patterns in the Iberian Peninsula, using a common non-viable volumetric sampling method. The highest mean annual spore counts were recorded in Sevilla (39,418 spores), Mérida (33,744) and Málaga (12,947), while other sampling stations never exceeded 5,000. The same cities also recorded the highest mean daily spore counts (Sevilla 109 spores m-3; Mérida 53 spores m-3 and Málaga 35 spores m-3) and the highest number of days on which counts exceeded the threshold levels required to trigger allergy symptoms (Sevilla 38 % and Mérida 30 % of days). Analysis of annual spore distribution patterns revealed either one or two peaks, depending on the location and prevailing climate of sampling stations. For all stations, average temperature was the weather parameter displaying the strongest positive correlation with airborne spore counts, whilst negative correlations were found for rainfall and relative humidity.

  14. Immunochemical quantitation of airborne short ragweed, Alternaria, antigen E, and Alt-I allergens: a two-year prospective study

    SciTech Connect

    Agarwal, M.K.; Swanson, M.C.; Reed, C.E.; Yunginger, J.W.

    1983-07-01

    We conducted a 2 yr prospective study to measure atmospheric short ragweed and Alternaria allergens by RAST inhibition analysis of eluates from filter sheets exposed in air samplers. In both years ragweed pollen and Alternaria spore counts, obtained with a rotoslide sampler, correlated significantly with immunochemically measured airborne ragweed and Alternaria allergenic activity. Airborne levels of the purified allergens AgE and Alt-I were successfully quantitated; these levels correlated closely with total airborne ragweed and Alternaria allergenic activities, respectively, and also with ragweed pollen and Alternaria spore counts. Eluates from filter sheets exposed during late summer and fall produced positive wheal-and-flare skin tests in patients with fall hay fever. In both years immunochemical measurements of allergenic activity due to airborne short ragweed correlated closely with mean symptom score indices in groups of short ragweed-sensitive individuals. Measurable levels of atmospheric ragweed allergenic activity were noted before and after the ragweed pollination season, and at these times we noted small increases in mean symptom score indices in the short ragweed-sensitive groups. Thus immunochemical analyses provide important information concerning levels of environmental allergens.

  15. Occurrence of Cladosporium spp. and Alternaria spp. spores in Western, Northern and Central-Eastern Poland in 2004-2006 and relation to some meteorological factors

    NASA Astrophysics Data System (ADS)

    Grinn-Gofroń, Agnieszka; Rapiejko, Piotr

    2009-08-01

    The concentration of airborne spores of Cladosporium spp. and Alternaria spp. has been investigated at three monitoring stations situated along the west-north and central-east transect in Poland (Szczecin, Olsztyn, Warszawa,) i.e. from a height of 100 m to 149 m above sea level. The aerobiological monitoring of fungal spores was performed by means of three Lanzoni volumetric spore traps. Cladosporium spp. spores were dominant at all the stations. The highest Cladosporium spp. and Alternaria spp. numbers of spores were observed at all the cities in July and August. Statistically significant correlations have been found between the Cladosporium spp. and Alternaria spp. concentration in the air and the mean air temperature, amount of precipitation, air pressure and relative air humidity. The spore count of Cladosporium spp. and Alternaria spp. is determined by the diversity of local flora and weather conditions, especially by the air temperature. The identification of factors, which influence and shape spore concentrations, may significantly improve the current methods of allergy prevention.

  16. Effects of meteorological factors on the levels of Alternaria spores on a potato crop

    NASA Astrophysics Data System (ADS)

    Escuredo, Olga; Seijo, Maria Carmen; Fernández-González, Maria; Iglesias, Isabel

    2011-03-01

    Alternaria solani Soraeur produces early blight in Solanum tuberosum L., leading to significant agricultural losses. The current study was carried out on the extensive potato crop situated in north-western of Spain during 2007, 2008 and 2009. In this area potato crops are the most important source of income. In this work we used a Hirst-type volumetric spore-trap for the aerobiological monitoring of Alternaria spores. The highest spore concentrations were recorded during the 2009 cycle (10,555 spores), and the lowest concentrations were recorded during the 2008 cycle (5,471 spores). Over the 3 years of study, the highest concentrations were registered during the last stage of the crop. The aim of the study was to observe the influence of meteorological factors on the concentration of Alternaria spores, which can lead to serious infection and early blight. Prediction of the stages during which a crop is particularly vulnerable to infection allows for adjustment of the application of fungicide and is of environmental and agricultural importance. For this reason, we tested three models (P-Days, DD and IWP) to predict the first treatment and decrease the negative effect that these spores have on potato crops. The parameter that showed the most significant correlation with spore concentrations was minimum temperature. We used ARIMA (autoregressive integrated model of running mean) time-series models to determine the forecast. We considered weather data as predictor variables and the concentration of spores on the previous day as the fixed variable.

  17. Analysis of global gene expression changes in human bronchial epithelial cells exposed to spores of the allergenic fungus, Alternaria alternata

    PubMed Central

    Babiceanu, M. C.; Howard, B. A.; Rumore, A. C.; Kita, H.; Lawrence, C. B.

    2013-01-01

    Exposure and sensitivity to ubiquitous airborne fungi such as Alternaria alternata have long been implicated in the development, onset, and exacerbation of chronic allergic airway disorders. This present study is the first to investigate global changes in host gene expression during the interaction of cultured human bronchial epithelial cells and live Alternaria spores. In in vitro experiments human bronchial epithelial cells (BEAS-2B) were exposed to spores or media alone for 24 h. RNA was collected from three biological replicates per treatment and was used to assess changes in gene expression patterns using Affymetrix Human Genome U133 Plus 2.0 Arrays. In cells treated with Alternaria spores compared to controls, 613 probe sets representing 460 individual genes were found differentially expressed (p ≤ 0.05). In this set of 460 statistically significant, differentially expressed genes, 397 genes were found to be up-regulated and 63 were down-regulated. Of these 397 up-regulated genes, 156 genes were found to be up-regulated ≥2 fold. Interestingly, none of the 63 down-regulated genes were found differentially expressed at ≤−2 fold. Differentially expressed genes were identified following statistical analysis and subsequently used for pathway and network evaluation. Interestingly, many cytokine and chemokine immune response genes were up-regulated with a particular emphasis on interferon-inducible genes. Genes involved in cell death, retinoic acid signaling, and TLR3 response pathways were also significantly up-regulated. Many of the differentially up-regulated genes have been shown in other systems to be associated with innate immunity, inflammation and/or allergic airway diseases. This study now provides substantial information for further investigating specific genes and innate immune system pathways activated by Alternaria in the context of allergic airway diseases. PMID:23882263

  18. Hourly predictive artificial neural network and multivariate regression tree models of Alternaria and Cladosporium spore concentrations in Szczecin (Poland)

    NASA Astrophysics Data System (ADS)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2009-11-01

    A study was made of the link between time of day, weather variables and the hourly content of certain fungal spores in the atmosphere of the city of Szczecin, Poland, in 2004-2007. Sampling was carried out with a Lanzoni 7-day-recording spore trap. The spores analysed belonged to the taxa Alternaria and Cladosporium. These spores were selected both for their allergenic capacity and for their high level presence in the atmosphere, particularly during summer. Spearman correlation coefficients between spore concentrations, meteorological parameters and time of day showed different indices depending on the taxon being analysed. Relative humidity (RH), air temperature, air pressure and clouds most strongly and significantly influenced the concentration of Alternaria spores. Cladosporium spores correlated less strongly and significantly than Alternaria. Multivariate regression tree analysis revealed that, at air pressures lower than 1,011 hPa the concentration of Alternaria spores was low. Under higher air pressure spore concentrations were higher, particularly when RH was lower than 36.5%. In the case of Cladosporium, under higher air pressure (>1,008 hPa), the spores analysed were more abundant, particularly after 0330 hours. In artificial neural networks, RH, air pressure and air temperature were the most important variables in the model for Alternaria spore concentration. For Cladosporium, clouds, time of day, air pressure, wind speed and dew point temperature were highly significant factors influencing spore concentration. The maximum abundance of Cladosporium spores in air fell between 1200 and 1700 hours.

  19. Airborne pollen and spores of León (Spain)

    NASA Astrophysics Data System (ADS)

    Fernández-González, Delia; Suarez-Cervera, María; Díaz-González, Tomás; Valencia-Barrera, Rosa María

    1993-06-01

    A qualitative and quantitative analysis of airborne pollen and spores was carried out over 2 years (from September 1987 to August 1989) in the city of León. Slides were prepared daily using a volumetric pollen trap, which was placed on the Faculty of Veterinary Science building (University of León) 12m above ground-level. Fifty-one pollen types were observed; the most important of these were: Cupressaceae during the winter, Pinus and Quercus in spring, and Poaceae, Leguminosae and Chenopodiaceae in the summer. The results also showed the existence of a rich mould spore assemblage in the atmosphere. The group of Amerospores ( Penicillium, Aspergillus and Cladosporium) as well as Dictyospores ( Alternaria) were the most abundant; Puccinia was common in the air in August. Fluctuations in the total pollen and spores m3 of air were compared with meteorological parameters (temperature, relative humidity and rainfall). From the daily sampling of the atmosphere of León, considering the maximum and minimum temperature and duration of rainfall, the start of the pollen grain season was observed generally to coincide with a rise in temperature in the absence of rain.

  20. Prevalence of culturable airborne spores of selected allergenic and pathogenic fungi in outdoor air

    NASA Astrophysics Data System (ADS)

    O'Gorman, Céline M.; Fuller, Hubert T.

    2008-06-01

    Temporal and spatial variations in airborne spore concentrations of selected allergenic and pathogenic fungi were examined in Dublin, Ireland, in 2005. Air samples were taken at four outdoor locations in the city every 2 weeks, coupled with measurements of meteorological conditions. Total culturable airborne fungal spore concentrations in Dublin ranged from 30-6800 colony forming units per cubic metre of air (CFU m-3) over the 12-month period. Cladosporium, Penicillium, Aspergillus and Alternaria spores were constantly present in the Dublin atmosphere, representing >20% of the total culturable spore count. Concentrations of Cladosporium increased significantly in summer and reached allergenic threshold levels, peaking at over 3200 CFU m-3 in August. Penicillium spore concentrations never reached allergenic threshold levels, with average concentrations of <150 CFU m-3. Alternaria conidia formed only 0.3% of the total culturable fungal spore count and concentrations never exceeded 50 CFU m-3, attributable to the coastal position of Dublin and its low levels of arable production. The opportunistic human pathogen Aspergillus fumigatus was present throughout the year in nominal concentrations (<10 CFU m-3), but sporadic high counts were also recorded (300-400 CFU m-3), the potential health implications of which give cause for concern. Spores of neither Cryptococcus neoformans nor Stachybotrys chartarum were detected, but airborne basidiospores of Schizophyllum commune were evidenced by the dikaryotization of monokaryon tester strains following exposure to the air. The relationships between airborne fungal spore concentrations and meteorological factors were analysed by redundancy analysis and revealed positive correlations between temperature and Cladosporium and relative humidity and Penicillium and Aspergillus.

  1. Airborne myxomycete spores: detection using molecular techniques

    NASA Astrophysics Data System (ADS)

    Kamono, Akiko; Kojima, Hisaya; Matsumoto, Jun; Kawamura, Kimitaka; Fukui, Manabu

    2009-01-01

    Myxomycetes are organisms characterized by a life cycle that includes a fruiting body stage. Myxomycete fruiting bodies contain spores, and wind dispersal of the spores is considered important for this organism to colonize new areas. In this study, the presence of airborne myxomycetes and the temporal changes in the myxomycete composition of atmospheric particles (aerosols) were investigated with a polymerase chain reaction (PCR)-based method for Didymiaceae and Physaraceae. Twenty-one aerosol samples were collected on the roof of a three-story building located in Sapporo, Hokkaido Island, northern Japan. PCR analysis of DNA extracts from the aerosol samples indicated the presence of airborne myxomycetes in all the samples, except for the one collected during the snowfall season. Denaturing gradient gel electrophoresis (DGGE) analysis of the PCR products showed seasonally varying banding patterns. The detected DGGE bands were subjected to sequence analyses, and four out of nine obtained sequences were identical to those of fruiting body samples collected in Hokkaido Island. It appears that the difference in the fruiting period of each species was correlated with the seasonal changes in the myxomycete composition of the aerosols. Molecular evidence shows that newly formed spores are released and dispersed in the air, suggesting that wind-driven dispersal of spores is an important process in the life history of myxomycetes. This study is the first to detect airborne myxomycetes with the use of molecular ecological analyses and to characterize their seasonal distribution.

  2. Apparatus and method for automated monitoring of airborne bacterial spores

    NASA Technical Reports Server (NTRS)

    Ponce, Adrian (Inventor)

    2009-01-01

    An apparatus and method for automated monitoring of airborne bacterial spores. The apparatus is provided with an air sampler, a surface for capturing airborne spores, a thermal lysis unit to release DPA from bacterial spores, a source of lanthanide ions, and a spectrometer for excitation and detection of the characteristic fluorescence of the aromatic molecules in bacterial spores complexed with lanthanide ions. In accordance with the method: computer-programmed steps allow for automation of the apparatus for the monitoring of airborne bacterial spores.

  3. Airborne and allergenic fungal spores of the Karachi environment and their correlation with meteorological factors.

    PubMed

    Hasnain, Syed M; Akhter, Tasneem; Waqar, Muhammad A

    2012-03-01

    Airborne fungal spores are well known to cause respiratory allergic diseases particularly bronchial asthma, allergic rhinitis, rhino-conjunctivitis and allergic broncho-pulmonary aspergillosis in both adults and children. In order to monitor and analyze airborne fungal flora of the Karachi environment, an aeromycological study was conducted using a Burkard 7-Day Recording Volumetric Spore Trap from January to December 2010. The data recorded from the Spore Trap was further analyzed for percent catch determination, total spores concentration, seasonal periodicities and diurnal variations. Cladosporium spp (44.8%), Alternaria spp. (15.5%), Periconia spp (6.1%), Curvularia spp (2.1%), Stemphylium spp (1.3%) and Aspergillus/Penicillium type (1%) emerged to be major components constituting more than 70% of the airborne fungal flora. Cladosporium, Curvularia and Stemphylium displayed a clear seasonal trend, while there were no clear seasonal trends for other fungal spore types. Diurnal variations were observed to be mainly having daytime maxima. Spearman Rank Correlation Coefficient analysis was conducted using various weather parameters. The various fungal types showed a negative correlation with heat index, dew point, wind velocity and wind chill. However, a positive correlation was found with humidity, rain and barometric pressure. In fact, Alternaria, Bipolaris and Periconia showed a negative correlation with temperature, while Cladosporium and Periconia showed a negative correlation with heat index, dew point, wind velocity and wind chill. The barometric pressure was positively correlated with Cladosporium. On the basis of these findings, it can be concluded that a number of fungal spores are present in the atmosphere of Karachi throughout the year, with certain atmospheric conditions influencing the release, dispersion, and sedimentation processes of some genera. It is expected that clinicians will use the identified fungal flora for diagnosis and treatment and

  4. The role of meteorological factors in determining the annual variation of Alternaria and Cladosporium spores in the atmosphere of Palencia, 1990 1992

    NASA Astrophysics Data System (ADS)

    Herrero, B.; Fombella-Blanco, M. A.; Fernández-González, D.; Valencia-Barrera, R. M.

    1996-09-01

    A study was made of the daily content of Alternaria and Cladosporium spores in the atmosphere in Palencia city (Spain) for three consecutive years 1990 1992. Alternaria and Cladosporium represented 55% of the total identified spores, presenting an annual distributional pattern of which the maximum values were reached in summer. Multiple regression analyses showed a positive correlation between minimum temperature and Cladosporium spore concentrations, while for Alternaria there was a positive correlation with maximum temperature and a negative correlation with precipitation. Duncan's multiple range test among means of Alternaria data indicated that winds coming from a northeasterly direction were associated with significantly higher concentrations the spores.

  5. Enumerating Spore-Forming Bacteria Airborne with Particles

    NASA Technical Reports Server (NTRS)

    Lin, Ying; Barengoltz, Jack

    2006-01-01

    A laboratory method has been conceived to enable the enumeration of (1) Cultivable bacteria and bacterial spores that are, variously, airborne by themselves or carried by, parts of, or otherwise associated with, other airborne particles; and (2) Spore-forming bacteria among all of the aforementioned cultivable microbes.

  6. Air pollution by allergenic spores of the genus Alternaria in the air of central and eastern Europe.

    PubMed

    Kasprzyk, Idalia; Rodinkova, Victoria; Šaulienė, Ingrida; Ritenberga, Olga; Grinn-Gofron, Agnieszka; Nowak, Malgorzata; Sulborska, Aneta; Kaczmarek, Joanna; Weryszko-Chmielewska, Elzbieta; Bilous, Elena; Jedryczka, Malgorzata

    2015-06-01

    Spores of the genus Alternaria belong to one of the most prevailing constituents of the air in all regions of the world. They form infectious inoculum of numerous plant species as well as severe inhaled allergies. The aim of this study was to compare the biological pollution with Alternaria spores of the air of 12 cities located in central and eastern Europe. The experiment was done in 2010 and it covered the territory of Latvia (LV), Lithuania (LT), Poland (PL) and Ukraine (UA). The spores were counted using an identical method and standard equipment (7-day Lanzoni volumetric sampler) followed by extensive statistical calculations. The timing of the day of maximum concentration changed mainly along the N-S direction and had a positive correlation with latitude. The most important factor determining the increase in Alternaria spore concentration was the temperature, whereas other weather parameters were not related or of low significance. Regardless of geographical location, the first phase of the season (0-0.9 % of Alternaria spores in the air) was the longest (up to 60 days) and the last (97.5 to 99 %) was the shortest (22 days or less). The means of daily concentrations of Alternaria spores ranged from 11 spores m(-3) in Klaipeda (LT, Baltic Sea coast) to 187 in Poznan (west PL, agricultural plain). The threshold value of 80 spores m(-3) that triggers the first allergy symptoms was exceeded in 8 to 86 days (Vinnitsa, UA, temperate continental, forest-steppes region). There were considerable differences between the highest number of spores per cubic metre of air, varying from 139 in the north (Klaipeda, LT) to 2,295 in central west (Poznan, PL). The biological pollution by Alternaria spores in several places of central and eastern Europe was high; the number of days exceeding the threshold value of 300 spores m(-3) connected with serious health problems of atopic people ranged from 0 to 1 on the north (LV, LT) to 29 in central west (Poznan, PL). PMID:25592912

  7. Influence of urban climate upon distribution of airborne Deuteromycete spore concentrations in Mexico City

    NASA Astrophysics Data System (ADS)

    Calderón, C.; Lacey, J.; McCartney, A.; Rosas, I.

    The effect of an urban climate upon the spatial and temporal distribution of Deuteromycete spores was studied during 1991 using Burkard volumetric spore traps in two areas of Mexico City with different degrees of urbanization. Deuteromycete conidia formed the largest component of the total airborne fungal spore load in the atmosphere of Mexico City, contributing 52% of the spores trapped in an urban-residential area (southern area) and 65% of those in an urban-commercial area (central area). Among the most common spore types, Cladosporium and Alternaria showed a marked seasonal periodicity with significant differences in concentration (P<0.05) between the dry and wet seasons. Maximum conidial concentrations were found during the end of the wet season and the beginning of the cool, dry season (October-December). Daily mean concentrations of the predominant airborne spore types did not differ significantly between the southern and central areas. Daily mean spore concentrations were significantly correlated (P<0.05) in southern and central areas with maximum temperature (south, r = -0.35 central, r = -0.40) and relative humidity (south, r = 0.43; central, r = 0.29) from the previous day. Moreover, multiple regression analysis of spore concentrations with several meteorological factors showed significant interactions between fungal spores, relative humidity and maximum temperature in both areas. The diurnal periodicity of Cladosporium conidia characteristically showed two or three peaks in concentration during the day at 0200-0400, 1400 and 2000-2200 hours, while that of Alternaria showed only one peak (1200 to 2000 hours) in both areas. Maximum concentrations of these spores generally occurred 2-4 h earlier in the southern than in the central area. The lag in reaching maximum concentrations in the central area probably resulted from differences in the local conditions between the study areas, and from spores transported aerially into the city from distant sources. The

  8. Seasonal Trends in Airborne Fungal Spores in Coastal California Ecosystems

    NASA Astrophysics Data System (ADS)

    Morfin, J.; Crandall, S. G.; Gilbert, G. S.

    2014-12-01

    Airborne fungal spores cause disease in plants and animals and may trigger respiratory illnesses in humans. In terrestrial systems, fungal sporulation, germination, and persistence are strongly regulated by local meteorological conditions. However, few studies investigate how microclimate affects the spatio-temporal dynamics of airborne spores. We measured fungal aerospora abundance and microclimate at varying spatial and time scales in coastal California in three habitat-types: coast redwood forest, mixed-evergreen forest, and maritime chaparral. We asked: 1) is there a difference in total airborne spore concentration between habitats, 2) when do we see peak spore counts, and 3) do spore densities correlate with microclimate conditions? Fungal spores were caught from the air with a volumetric vacuum air spore trap during the wet season (January - March) in 2013 and 2014, as well as monthly in 2014. Initial results suggest that mixed-evergreen forests exhibit the highest amounts of spore abundance in both years compared to the other habitats. This may be due to either a higher diversity of host plants in mixed-evergreen forests or a rich leaf litter layer that may harbor a greater abundance of saprotrophic fungi. Based on pilot data, we predict that temperature and to a lesser degree, relative humidity, will be important microclimate predictors for high spore densities. These data are important for understanding when and under what weather conditions we can expect to see high levels of fungal spores in the air; this can be useful information for managers who are interested in treating diseased plants with fungicides.

  9. Thirty-four identifiable airborne fungal spores in Havana, Cuba.

    PubMed

    Almaguer, Michel; Aira, María-Jesús; Rodríguez-Rajo, F Javier; Fernandez-Gonzalez, Maria; Rojas-Flores, Teresa I

    2015-01-01

    The airborne fungal spore content in Havana, Cuba, collected by means a non-viable volumetric methodology, was studied from November 2010 - October 2011. The study, from a qualitative point of view, allowed the characterization of 29 genera and 5 fungal types, described following the Saccardo´s morphotypes, as well as their morphobiometrical characteristics. In the amerospores morphotype, the conidia of 7 genera (with ascospores, basidiospores and uredospores) and 5 fungal types were included. Among phragmospores morphotype, the ascospores and conidia of 12 different genera were identified. The dictyospores morphotype only included conidial forms from 6 genera. Finally, the less frequent morphotypes were staurospores, didymospores and distosepted spores. In general, the main worldwide spread mitosporic fungi also predominated in the Havana atmosphere, accompanied by some ascospores and basidiospores. Cladosporium cladosporioides type was the most abundant with a total of 148,717 spores, followed by Leptosphaeria, Coprinus and the Aspergillus-Penicillium type spores, all of them with total values ranging from 20,591 - 16,392 spores. The higher monthly concentrations were registered in January (31,663 spores) and the lowest in December (7,314 spores). Generally, the average quantity of spores recorded during the months of the dry season (20,599 spores) was higher compared with that observed during the rainy season (17,460 spores). PMID:26094511

  10. The effect of meteorological factors on the daily variation of airborne fungal spores in Granada (southern Spain)

    NASA Astrophysics Data System (ADS)

    Sabariego, S.; Díaz de la Guardia, C.; Alba, F.

    A study was made of the link between climatic factors and the daily content of certain fungal spores in the atmosphere of the city of Granada in 1994. Sampling was carried out with a Burkard 7-day-recording spore trap. The spores analysed corresponded to the taxa Alternaria, Ustilago and Cladosporium, with two morphologically different spore types in the latter genus, cladosporioides and herbarum. These spores were selected both for their allergenic capacity and for the high level of their presence in the atmosphere, particularly during the spring and autumn. The spores of Cladosporium were the most abundant (93.82% of the total spores identified). The Spearman correlation coefficients between the spore concentrations studied and the meteorological parameters show different indices depending on the taxon being analysed. Alternaria and Cladosporium are significantly correlated with temperature and hours of sunlight, while Ustilago shows positive correlation indices with relative humidity and negative indices with wind speed.

  11. Non-Seasonal Variation of Airborne Aspergillus Spore Concentration in a Hospital Building.

    PubMed

    Oberle, Michael; Reichmuth, Markus; Laffer, Reto; Ottiger, Cornelia; Fankhauser, Hans; Bregenzer, Thomas

    2015-11-01

    Nosocomial fungal infections are gaining increased attention from infectiologists. An adequate investigation into the levels of airborne Aspergillus and other fungal spores in hospital settings, under normal conditions, is largely unknown. We monitored airborne spore contamination in a Swiss hospital building in order to establish a seasonally-dependent base-line level. Air was sampled using an impaction technique, twice weekly, at six different locations over one year. Specimens were seeded in duplicate on Sabouraud agar plates. Grown colonies were identified to genus levels. The airborne Aspergillus spore concentration was constantly low throughout the whole year, at a median level of 2 spores/m³ (inter-quartile range = IQR 1-4), and displayed no seasonal dependency. The median concentration of other fungal spores was higher and showed a distinct seasonal variability with the ambient temperature change during the different seasons: 82 spores/m³ (IQR 26-126) in summer and 9 spores/m³ (IQR 6-15) in winter. The spore concentration varied considerably between the six sampling sites in the building (10 to 26 spores/m³). This variability may explain the variability of study results in the literature. PMID:26516890

  12. Non-Seasonal Variation of Airborne Aspergillus Spore Concentration in a Hospital Building

    PubMed Central

    Oberle, Michael; Reichmuth, Markus; Laffer, Reto; Ottiger, Cornelia; Fankhauser, Hans; Bregenzer, Thomas

    2015-01-01

    Nosocomial fungal infections are gaining increased attention from infectiologists. An adequate investigation into the levels of airborne Aspergillus and other fungal spores in hospital settings, under normal conditions, is largely unknown. We monitored airborne spore contamination in a Swiss hospital building in order to establish a seasonally-dependent base-line level. Air was sampled using an impaction technique, twice weekly, at six different locations over one year. Specimens were seeded in duplicate on Sabouraud agar plates. Grown colonies were identified to genus levels. The airborne Aspergillus spore concentration was constantly low throughout the whole year, at a median level of 2 spores/m3 (inter-quartile range = IQR 1–4), and displayed no seasonal dependency. The median concentration of other fungal spores was higher and showed a distinct seasonal variability with the ambient temperature change during the different seasons: 82 spores/m3 (IQR 26–126) in summer and 9 spores/m3 (IQR 6–15) in winter. The spore concentration varied considerably between the six sampling sites in the building (10 to 26 spores/m3). This variability may explain the variability of study results in the literature. PMID:26516890

  13. The effects of meteorological factors on airborne fungal spore concentration in two areas differing in urbanisation level

    NASA Astrophysics Data System (ADS)

    Oliveira, M.; Ribeiro, H.; Delgado, J. L.; Abreu, I.

    2009-01-01

    Although fungal spores are an ever-present component of the atmosphere throughout the year, their concentration oscillates widely. This work aims to establish correlations between fungal spore concentrations in Porto and Amares and meteorological data. The seasonal distribution of fungal spores was studied continuously (2005-2007) using volumetric spore traps. To determine the effect of meteorological factors (temperature, relative humidity and rainfall) on spore concentration, the Spearman rank correlation test was used. In both locations, the most abundant fungal spores were Cladosporium, Agaricus, Agrocybe, Alternaria and Aspergillus/Penicillium, the highest concentrations being found during summer and autumn. In the present study, with the exception of Coprinus and Pleospora, spore concentrations were higher in the rural area than in the urban location. Among the selected spore types, spring-autumn spores ( Coprinus, Didymella, Leptosphaeria and Pleospora) exhibited negative correlations with temperature and positive correlations both with relative humidity and rainfall level. On the contrary, late spring-early summer (Smuts) and summer spores ( Alternaria, Cladosporium, Epicoccum, Ganoderma, Stemphylium and Ustilago) exhibited positive correlations with temperature and negative correlations both with relative humidity and rainfall level. Rust, a frequent spore type during summer, had a positive correlation with temperature. Aspergillus/Penicillium, showed no correlation with the meteorological factors analysed. This knowledge can be useful for agriculture, allowing more efficient and reliable application of pesticides, and for human health, by improving the diagnosis and treatment of respiratory allergic disease.

  14. Spores

    MedlinePlus

    A spore is a cell that certain fungi, plants (moss, ferns), and bacteria produce. Spores are involved in reproduction. Certain bacteria make spores as a way to defend themselves. These spores have thick walls. They can resist high temperatures, ...

  15. Role of the Alternaria alternata Blue-Light Receptor LreA (White-Collar 1) in Spore Formation and Secondary Metabolism

    PubMed Central

    Pruß, Sonja; Fetzner, Ramona; Seither, Kristin; Herr, Andreas; Pfeiffer, Erika; Metzler, Manfred; Lawrence, Christopher B.

    2014-01-01

    Alternaria alternata is a filamentous fungus that causes considerable loss of crops of economically important feed and food worldwide. It produces more than 60 different secondary metabolites, among which alternariol (AOH) and altertoxin (ATX) are the most important mycotoxins. We found that mycotoxin production and spore formation are regulated by light in opposite ways. Whereas spore formation was largely decreased under light conditions, the production of AOH was stimulated 2- to 3-fold. ATX production was even strictly dependent on light. All light effects observed could be triggered by blue light, whereas red light had only a minor effect. Inhibition of spore formation by light was reversible after 1 day of incubation in the dark. We identified orthologues of genes encoding the Neurospora crassa blue-light-perceiving white-collar proteins, a cryptochrome, a phytochrome, and an opsin-related protein in the genome of A. alternata. Deletion of the white-collar 1 (WC-1) gene (lreA) resulted in derepression of spore formation in dark and in light. ATX formation was strongly induced in the dark in the lreA mutant, suggesting a repressing function of LreA, which appears to be released in the wild type after blue-light exposure. In addition, light induction of AOH formation was partially dependent on LreA, suggesting also an activating function. A. alternata ΔlreA was still able to partially respond to blue light, indicating the action of another blue-light receptor system. PMID:24532063

  16. Development of a new technique using glass beads for dry dispersion of airborne fungal spores.

    PubMed

    Shimasaki, Noriko; Okaue, Akira; Kikuno, Ritsuko; Okuda, Shunji; Abe, Keiko

    2015-01-01

    To evaluate the removal of airborne microbes by air cleaners, a technique for generating airborne fungal spores in the dry state in a test chamber (dry dispersion) become necessary. The Society of Indoor Environment Japan (SIEJ) published SIEJ Standard Method No. 20110001 (SIEJ standard),in which an aerial ultrasonic oscillator was used as the device for dry dispersion. However, a more versatile apparatus is also necessary from a practical point of view. Therefore, we developed a new device using glass beads for the dispersion. Glass beads and a fungal sheet containing spores of Wallemia sebi were set in a midget impinger, which was connected to a compressor and a compact test chamber (1 m(3)). Air was blown into the impinger from the compressor. The spores on the fungal sheet were released by impingement of the glass beads when the beads were induced to float by the air blown into the impinger, and the spores were introduced to the chamber by the airflow. This newly developed technique can be used in a compact chamber system and could be applicable as an improved method for generating airborne fungal spores in the dry state in the SIEJ standard. PMID:25817813

  17. Allergenic airborne pollen and spores in Anchorage, Alaska

    SciTech Connect

    Anderson, J.H.

    1985-05-01

    Major aeroallergens in Anchorage are birch, alder, poplar, spruce, grass pollen, Cladosporium, and unspecified fungus spores. Lesser pollens are sorrel, willow, pine, juniper, sedge, lamb's-quarters, wormwood, plantain, and others. The aero-flora is discussed in terms of the frequency of allergenically significant events and within-season and year-to-year dynamics.

  18. Control of airborne fungal spores in a university hospital

    SciTech Connect

    Streifel, A.J.; Vesley, D. ); Rhame, F.S. ); Murray, B. )

    1989-01-01

    A new university hospital was designed to maximize the air quality protection of severely compromised patients undergoing transplantation or treatment for malignant disorders. The entire hospital was designed as a sealed building with two filter systems having >95% efficiencies for 1.0 {mu}m particles. Controlled airflow and isolation of the most severely compromised patients were also design features. Air quality monitoring of particles and airborne fungi demonstrate effective control in the patient environment. The results show the areas with the greatest control of personnel and air changes have the lowest airborne concentrations of fungi and the smallest particles. Larger indoor airborne particle ranking indicate highest levels depending on local human activity, air changes rates, or filtration efficiency.

  19. Spores

    MedlinePlus

    ... do not destroy their spores. A process called sterilization destroys spores and bacteria. It is done at ... and under high pressures. In health care settings, sterilization is usually done using a device called an ...

  20. Effects of meteorological factors on airborne bracken ( Pteridium aquilinum (L.) Kuhn.) spores in Salamanca (middle-west Spain)

    NASA Astrophysics Data System (ADS)

    Rodríguez de La Cruz, David; Sánchez Reyes, Estefanía; Sánchez Sánchez, José

    2009-05-01

    Temporal variation of airborne bracken ( Pteridium aquilinum) spores concentration in Salamanca during 10 years from January 1998 to December 2007 were studied by using a Burkard spore trap, and correlations with some meteorological parameters were analyzed. The number of spores that were counted was very low, due probably to the distance between the spore trap and the main bracken populations which were located 70 km away from the city. Long-range transport caused by winds coming from the Second Quadrant (IIQ) is supposed to be responsible for the appearance of bracken spores in Salamanca. The season period from August to late October shows the most intense spore dispersal process, with an early morning distribution along the day. Years 2002 and 2007 with a low quantity of airborne spores were also characterized by low mean temperatures, always under 18°C from May to June. Daily spore concentration shows positive correlation with temperature and sun hours but negative with IVQ winds and with relative humidity. No correlation between daily spore concentration and rainfall was found. Also, a positive correlation between number of spores and IIQ winds was observed during the main spore season (MSS) and prepeak period (PRE).

  1. Effects of meteorological conditions on spore plumes

    NASA Astrophysics Data System (ADS)

    Burch, M.; Levetin, E.

    2002-05-01

    Fungal spores are an ever-present component of the atmosphere, and have long been known to trigger asthma and hay fever symptoms in sensitive individuals. The atmosphere around Tulsa has been monitored for airborne spores and pollen with Burkard spore traps at several sampling stations. This study involved the examination of the hourly spore concentrations on days that had average daily concentrations near 50,000 spores/m3 or greater. Hourly concentrations of Cladosporium, Alternaria, Epicoccum, Curvularia, Pithomyces, Drechslera, smut spores, ascospores, basidiospores, other, and total spores were determined on 4 days at three sites and then correlated with hourly meteorological data including temperature, rainfall, wind speed, dew point, air pressure, and wind direction. On each of these days there was a spore plume, a phenomenon in which spore concentrations increased dramatically over a very short period of time. Spore plumes generally occurred near midday, and concentrations were seen to increase from lows around 20,000 total spores/m3 to highs over 170,000 total spores/m3 in 2 h. Multiple regression analysis of the data indicated that increases in temperature, dew point, and air pressure correlated with the increase in spore concentrations, but no single weather variable predicted the appearance of a spore plume. The proper combination of changes in these meteorological parameters that result in a spore plume may be due to the changing weather conditions associated with thunderstorms, as on 3 of the 4 days when spore plumes occurred there were thunderstorms later that evening. The occurrence of spore plumes may have clinical significance, because other studies have shown that sensitization to certain spore types can occur during exposure to high spore concentrations.

  2. Alternaria redefined

    PubMed Central

    Woudenberg, J.H.C.; Groenewald, J.Z.; Binder, M.; Crous, P.W.

    2013-01-01

    Alternaria is a ubiquitous fungal genus that includes saprobic, endophytic and pathogenic species associated with a wide variety of substrates. In recent years, DNA-based studies revealed multiple non-monophyletic genera within the Alternaria complex, and Alternaria species clades that do not always correlate to species-groups based on morphological characteristics. The Alternaria complex currently comprises nine genera and eight Alternaria sections. The aim of this study was to delineate phylogenetic lineages within Alternaria and allied genera based on nucleotide sequence data of parts of the 18S nrDNA, 28S nrDNA, ITS, GAPDH, RPB2 and TEF1-alpha gene regions. Our data reveal a Pleospora/Stemphylium clade sister to Embellisia annulata, and a well-supported Alternaria clade. The Alternaria clade contains 24 internal clades and six monotypic lineages, the assemblage of which we recognise as Alternaria. This puts the genera Allewia, Brachycladium, Chalastospora, Chmelia, Crivellia, Embellisia, Lewia, Nimbya, Sinomyces, Teretispora, Ulocladium, Undifilum and Ybotromyces in synonymy with Alternaria. In this study, we treat the 24 internal clades in the Alternaria complex as sections, which is a continuation of a recent proposal for the taxonomic treatment of lineages in Alternaria. Embellisia annulata is synonymised with Dendryphiella salina, and together with Dendryphiella arenariae, are placed in the new genus Paradendryphiella. The sexual genera Clathrospora and Comoclathris, which were previously associated with Alternaria, cluster within the Pleosporaceae, outside Alternaria s. str., whereas Alternariaster, a genus formerly seen as part of Alternaria, clusters within the Leptosphaeriaceae. Paradendryphiella is newly described, the generic circumscription of Alternaria is emended, and 32 new combinations and 10 new names are proposed. A further 10 names are resurrected, while descriptions are provided for 16 new Alternaria sections. Taxonomic novelties: New

  3. Thermal resistance of naturally occurring airborne bacterial spores. [Viking spacecraft dry heat decontamination simulation

    NASA Technical Reports Server (NTRS)

    Puleo, J. R.; Bergstrom, S. L.; Peeler, J. T.; Oxborrow, G. S.

    1978-01-01

    Simulation of a heat process used in the terminal dry-heat decontamination of the Viking spacecraft is reported. Naturally occurring airborne bacterial spores were collected on Teflon ribbons in selected spacecraft assembly areas and subsequently subjected to dry heat. Thermal inactivation experiments were conducted at 105, 111.7, 120, 125, 130, and 135 C with a moisture level of 1.2 mg of water per liter. Heat survivors were recovered at temperatures of 135 C when a 30-h heating cycle was employed. Survivors were recovered from all cycles studied and randomly selected for identification. The naturally occurring spore population was reduced an average of 2.2 to 4.4 log cycles from 105 to 135 C. Heating cycles of 5 and 15 h at temperature were compared with the standard 30-h cycle at 111.7, 120, and 125 C. No significant differences in inactivation (alpha = 0.05) were observed between 111.7 and 120 C. The 30-h cycle differs from the 5- and 15-h cycles at 125 C. Thus, the heating cycle can be reduced if a small fraction (about 0.001 to 0.0001) of very resistant spores can be tolerated.

  4. Influence of atmospheric ozone, PM 10 and meteorological factors on the concentration of airborne pollen and fungal spores

    NASA Astrophysics Data System (ADS)

    Sousa, S. I. V.; Martins, F. G.; Pereira, M. C.; Alvim-Ferraz, M. C. M.; Ribeiro, H.; Oliveira, M.; Abreu, I.

    The increase of allergenic symptoms has been associated with air contaminants such as ozone, particulate matter, pollen and fungal spores. Considering the potential relevance of crossed effects of non-biological pollutants and airborne pollens and fungal spores on allergy worsening, the aim of this work was to evaluate the influence of non-biological pollutants and meteorological parameters on the concentrations of pollen and fungal spores using linear correlations and multiple linear regressions. For that, the seasonal variation of ozone, particulate matter with an equivalent aerodynamic diameter smaller than 10 μm, pollen and fungal spores were assessed and statistical correlations were analysed between those parameters. The data were collected through 2003-2005 in Porto, Portugal. The linear correlations showed that ozone and particulate matter had no significant influence on the concentration of pollen and fungal spores. On the contrary, when using multiple linear regressions those parameters showed to have some influence on the biological pollutants, although results were different depending on the year analysed. Among the meteorological parameters analysed, temperature was the one that most influenced the pollen and fungal spores airborne concentrations, both when using linear and multiple linear correlations. Relative humidity also showed to have some influence on the fungal spore dispersion when multiple linear regressions were used. Nevertheless, the conclusions for each pollen and fungal spore were different depending on the analysed period, which means that the correlations identified as statistically significant may not be, even so, consistent enough. Furthermore, the comparison of the results here presented with those obtained by other authors for only one period should be made carefully.

  5. Discriminating bacterial spores from inert airborne particles by classification of optical scattering patterns

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni F.; Pan, Yongle; Videen, Gorden

    2014-05-01

    Scattering patterns are made available by the TAOS (Two-dimensional Angle-resolved Optical Scattering) method, which consists of detecting micrometer-sized single airborne aerosol particles and collecting the intensity of the light they scatter from a pulsed, monochromatic laser beam. TAOS patterns have been classified by a learning machine, the training stage of which depends on many control parameters. Patterns due to single bacterial spores (Bq class) have to be discriminated from those produced by outdoor aerosol particles (Kq set) and diesel soot aggregates (sq set), where both Kq and sq are assumed not to contain patterns of bacterial origin. This work describes two directions along which classification continues to develop: the enlargement of the control parameter set and the simultaneous processing of two areas (sectors) selected from the TAOS pattern. The latter algorithm is meant to make the classifier sensitive to simmetry exhibited by some patterns. The available classification scheme is summarized, as well as the rule by which discrimination is rated off-line. Discrimination based on one pattern sector alone scores fewer than 15% false negatives (misclassified Bq patterns) and false positives from Kq and sq. Discrimination based on the symmetry of two pattern sectors fails to recognize 30% of the Bq (bacterial) patterns, whereas < 5% Kq (environmental) patterns are assigned to the Bq class; false positives from sq (diesel) patterns drop to zero. The issue of false positives is briefly discussed in relation to the fraction of airborne bacteria found in aerosols.

  6. Alternaria section Alternaria: Species, formae speciales or pathotypes?

    PubMed Central

    Woudenberg, J.H.C.; Seidl, M.F.; Groenewald, J.Z.; de Vries, M.; Stielow, J.B.; Thomma, B.P.H.J.; Crous, P.W.

    2015-01-01

    The cosmopolitan fungal genus Alternaria consists of multiple saprophytic and pathogenic species. Based on phylogenetic and morphological studies, the genus is currently divided into 26 sections. Alternaria sect. Alternaria contains most of the small-spored Alternaria species with concatenated conidia, including important plant, human and postharvest pathogens. Species within sect. Alternaria have been mostly described based on morphology and / or host-specificity, yet molecular variation between them is minimal. To investigate whether the described morphospecies within sect. Alternaria are supported by molecular data, whole-genome sequencing of nine Alternaria morphospecies supplemented with transcriptome sequencing of 12 Alternaria morphospecies as well as multi-gene sequencing of 168 Alternaria isolates was performed. The assembled genomes ranged in size from 33.3–35.2 Mb within sect. Alternaria and from 32.0–39.1 Mb for all Alternaria genomes. The number of repetitive sequences differed significantly between the different Alternaria genomes; ranging from 1.4–16.5 %. The repeat content within sect. Alternaria was relatively low with only 1.4–2.7 % of repeats. Whole-genome alignments revealed 96.7–98.2 % genome identity between sect. Alternaria isolates, compared to 85.1–89.3 % genome identity for isolates from other sections to the A. alternata reference genome. Similarly, 1.4–2.8 % and 0.8–1.8 % single nucleotide polymorphisms (SNPs) were observed in genomic and transcriptomic sequences, respectively, between isolates from sect. Alternaria, while the percentage of SNPs found in isolates from different sections compared to the A. alternata reference genome was considerably higher; 8.0–10.3 % and 6.1–8.5 %. The topology of a phylogenetic tree based on the whole-genome and transcriptome reads was congruent with multi-gene phylogenies based on commonly used gene regions. Based on the genome and transcriptome data, a set of core

  7. Alternaria blight

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria blight of chickpea is caused by the fungal pathogen Alternaria alternata. The pathogen has wide host range, and affects all above ground parts of the plant. The disease occurs sporadically and occasionally could be economically important and causes significant damage. The pathogen can ...

  8. Culturability of Bacillus spores on aerosol collection filters exposed to airborne combustion products of Al, Mg, and B·Ti.

    PubMed

    Adhikari, Atin; Yermakov, Michael; Indugula, Reshmi; Reponen, Tiina; Driks, Adam; Grinshpun, Sergey A

    2016-05-01

    Destruction of bioweapon facilities due to explosion or fire could aerosolize highly pathogenic microorganisms. The post-event air quality assessment is conducted through air sampling. A bioaerosol sample (often collected on a filter for further culture-based analysis) also contains combustion products, which may influence the microbial culturability and, thus, impact the outcome. We have examined the interaction between spores deposited on collection filters using two simulants of Bacillus anthracis [B. thuringiensis (Bt) and B. atrophaeus (referred to as BG)] and incoming combustion products of Al as well as Mg and B·Ti (common ingredient of metalized explosives). Spores extracted from Teflon, polycarbonate, mixed cellulose ester (MCE), and gelatin filters (most common filter media for bioaerosol sampling), which were exposed to combustion products during a short-term sampling, were analyzed by cultivation. Surprisingly, we observed that aluminum combustion products enhanced the culturability of Bt (but not BG) spores on Teflon filters increasing the culturable count by more than an order of magnitude. Testing polycarbonate and MCE filter materials also revealed a moderate increase of culturability although gelatin did not. No effect was observed with either of the two species interacting on either filter media with products originated by combustion of Mg and B·Ti. Sample contamination, spore agglomeration, effect of a filter material on the spore survival, changes in the spore wall ultrastructure and germination, as well as other factors were explored to interpret the findings. The study raises a question about the reliability of certain filter materials for collecting airborne bio-threat agents in combustion environments. PMID:26914458

  9. Monitoring airborne fungal spores in an experimental indoor environment to evaluate sampling methods and the effects of human activity on air sampling.

    PubMed Central

    Buttner, M P; Stetzenbach, L D

    1993-01-01

    Aerobiological monitoring was conducted in an experimental room to aid in the development of standardized sampling protocols for airborne microorganisms in the indoor environment. The objectives of this research were to evaluate the relative efficiencies of selected sampling methods for the retrieval of airborne fungal spores and to determine the effect of human activity on air sampling. Dry aerosols containing known concentrations of Penicillium chrysogenum spores were generated, and air samples were taken by using Andersen six-stage, Surface Air System, Burkard, and depositional samplers. The Andersen and Burkard samplers retrieved the highest numbers of spores compared with the measurement standard, an aerodynamic particle sizer located inside the room. Data from paired samplers demonstrated that the Andersen sampler had the highest levels of sensitivity and repeatability. With a carpet as the source of P. chrysogenum spores, the effects of human activity (walking or vacuuming near the sampling site) on air sampling were also examined. Air samples were taken under undisturbed conditions and after human activity in the room. Human activity resulted in retrieval of significantly higher concentrations of airborne spores. Surface sampling of the carpet revealed moderate to heavy contamination despite relatively low airborne counts. Therefore, in certain situations, air sampling without concomitant surface sampling may not adequately reflect the level of microbial contamination in indoor environments. PMID:8439150

  10. Inhibition of Aspergillus flavus in soil by antagonistic Pseudomonas strains reduces the potential for airborne spore dispersal.

    PubMed

    Palumbo, Jeffrey D; O'Keeffe, Teresa L; Kattan, Ali; Abbas, Hamed K; Johnson, Bobbie J

    2010-06-01

    Pseudomonas chlororaphis strain JP1015 and P. fluorescens strain JP2175 were previously isolated from Mississippi cornfield soil samples and selected for their growth inhibition of Aspergillus flavus in laboratory culture. In this study, the antifungal activity of these bacterial strains against A. flavus in soil coculture was determined. Growth of A. flavus was inhibited up to 100-fold by P. chlororaphis strain JP1015 and up to 58-fold by P. fluorescens strain JP2175 within 3 days following soil coinoculation. A. flavus propagule densities after 16 days remained 7- to 20-fold lower in soil treated with either bacterial strain. Using a bench-scale wind chamber, we demonstrated that treatments of soil with P. chlororaphis strain JP1015 and P. fluorescens strain JP2175 reduced airborne spores dispersed across a 1 m distance by 75- to 1,000-fold and 10- to 50-fold, respectively, depending on soil type and inoculum level. These results suggest that application of these bacterial strains may be effective in reducing soil populations of mycotoxigenic fungi, thereby reducing fungal spore formation, and ultimately reducing the potential for crop plant infection via airborne transmission. PMID:20465408

  11. Particle size distribution of airborne Aspergillus fumigatus spores emitted from compost using membrane filtration

    NASA Astrophysics Data System (ADS)

    Deacon, L. J.; Pankhurst, L. J.; Drew, G. H.; Hayes, E. T.; Jackson, S.; Longhurst, P. J.; Longhurst, J. W. S.; Liu, J.; Pollard, S. J. T.; Tyrrel, S. F.

    Information on the particle size distribution of bioaerosols emitted from open air composting operations is valuable in evaluating potential health impacts and is a requirement for improved dispersion simulation modelling. The membrane filter method was used to study the particle size distribution of Aspergillus fumigatus spores in air 50 m downwind of a green waste compost screening operation at a commercial facility. The highest concentrations (approximately 8 × 10 4 CFU m -3) of culturable spores were found on filters with pore diameters in the range 1-2 μm which suggests that the majority of spores are emitted as single cells. The findings were compared to published data collected using an Andersen sampler. Results were significantly correlated ( p < 0.01) indicating that the two methods are directly comparable across all particles sizes for Aspergillus spores.

  12. Spores of most common airborne fungi reveal no ice nucleation activity

    NASA Astrophysics Data System (ADS)

    Pummer, B. G.; Atanasova, L.; Bauer, H.; Bernardi, J.; Druzhinina, I. S.; Grothe, H.

    2013-06-01

    Fungal spores are ubiquitous biological aerosols, which are considered to show ice nucleation (IN) activity. In this study the respective IN activity was tested in oil emulsion in the immersion freezing mode. The focus was laid on species of economical, ecological or sanitary significance. For the first time, not only common moulds, but also edible mushrooms (Basidiomycota, Agaricomycetes) were investigated, as they contribute massively to the total amount of fungal spores in the atmosphere. Only Fusarium avenaceum showed freezing events at low subzero-temperatures, while the other investigated fungal spores showed no significant IN activity. Furthermore, we selected a set of fungal strains from different sites and exposed them to occasional freezing stress during cultivation. Although the total protein expression was altered by this treatment, it had no significant impact on the IN activity.

  13. Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments

    NASA Astrophysics Data System (ADS)

    Pummer, B. G.; Atanasova, L.; Bauer, H.; Bernardi, J.; Druzhinina, I. S.; Fröhlich-Nowoisky, J.; Grothe, H.

    2013-12-01

    Fungal spores are ubiquitous biological aerosols, which are considered to act as ice nuclei. In this study the ice nucleation (IN) activity of spores harvested from 29 fungal strains belonging to 21 different species was tested in the immersion freezing mode by microscopic observation of water-in-oil emulsions. Spores of 8 of these strains were also investigated in a microdroplet freezing array instrument. The focus was laid on species of economical, ecological or sanitary significance. Besides common molds (Ascomycota), some representatives of the widespread group of mushrooms (Basidiomycota) were also investigated. Fusarium avenaceum was the only sample showing IN activity at relatively high temperatures (about 264 K), while the other investigated fungal spores showed no freezing above 248 K. Many of the samples indeed froze at homogeneous ice nucleation temperatures (about 237 K). In combination with other studies, this suggests that only a limited number of species may act as atmospheric ice nuclei. This would be analogous to what is already known for the bacterial ice nuclei. Apart from that, we selected a set of fungal strains from different sites and exposed them to occasional freezing stress during their cultivation. This was in order to test if the exposure to a cold environment encourages the expression of ice nuclei during growth as a way of adaptation. Although the total protein expression was altered by this treatment, it had no significant impact on the IN activity.

  14. Differential gene expression in Alternaria gaisen exposed to dark and light

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Character states observed during sporulation have been the basis for segregation and description of many of the small-spored species of Alternaria. Phylogenetic analyses of ITS and housekeeping genes from small-spored Alternaria spp. do not support most of the currently defined morphological specie...

  15. [Nature and frequency of the existence of mold fungi in garbage cans for biological waste and the resultant airborne spore pollution].

    PubMed

    Weinrich, M; Vissiennon, T; Kliche, R; Schumann, M; Bergmann, A

    1999-12-01

    In organic waste, numerous mold fungi and other microorganisms develop sometimes within a few hours only which decompose the organic material already in the collecting containers generating heat and odor. With regard to the emission of mold fungus spores out of garbage cans for bio-waste and the potential environmental-hygienic danger connected with it, considerable worries have been expressed recently. A wide spectrum of mold fungi can be found in bio-waste in strongly varying concentrations. No noticeable difference could be ascertained between the settlement structure areas and the cities respectively as to the fungus concentration in the bio-waste substrate. A. fumigatus and A. niger can be recommended as leading spores for the behavior of the total concentration of fungi in the bio-waste due to their frequency of detection and their seasonal dynamism. The intensity of the air spore pollution through emission of mold fungus spores correlates closely with the climatic conditions, such as variations of temperature, relative humidity and solar radiation. The airborne release of mold fungus spores out of garbage cans for bio-waste and the formation of a respective exposure connected with it is judged as harmless for healthy persons. Risk patients and persons having a weakened immune system or assumed to have such a one due to an existent basic illness and/or other reasons should avoid any handling of bio-waste as well as any other waste if possible. PMID:10638030

  16. The dynamics of the fungal aerospores Alternaria sp. and Cladosporium sp. in Parisian atmospheric air, in France

    NASA Astrophysics Data System (ADS)

    Brezoczki, V. M.

    2016-08-01

    The bioallergens occurring naturally in the atmospheric air are microorganisms, pollen grains, plant seeds, leaf and stem scrap, or their protein molecules. The presence of various airborne fungal spores determines a high allergenic potential for public health. This effect is due to the high number of produced spores, which under favourable meteorological conditions (dry weather and wind) reach the surrounding air. This paper traces the dynamics of two types of fungi, Alternaria sp and Cladosporium sp, fungi which can be found outdoors, in the surrounding air, as well as indoors, inside houses (especially the conidia of Cladosporium sp). The effects of these fungal spores on human health are varies, ranging from seasonal allergies (hay fever, rhinitis, sinusitis etc.) to sever afflictions of the respiratory system, onset of asthma, disfunctionalities of the nervous systems, of the immune system, zymoses etc. The monitoring of the dynamics of the aerospores Alternaria sp and Cladosporium sp was carried out between 2010 and 2013, over a period of 42 weeks during one calendar year, from February to the end of September, in the surrounding air in the French capital, Paris. The regional and global climate and meteorological conditions are directly involved in the occurrence and development of fungi colonies, the transportation and dispersion of fungal spores in the atmospheric air, as well as in the creation of the environment required for the interaction of chemical and biological components in the air. Knowledge of the dynamics of the studied fungal aerospores, coupled with climate and meteorological changes, offers a series of information on the magnitude of the allergenic potential these airborne spores can determine. Legal regulations in this domain set the allergen risk threshold for the Alternaria sp aerospores at 3500 ÷ 7000 spores/m3 air/week, and for the Cladosporium sp aerospores at 56,000 spores/m3 air/week. Besides these regulations there exist a series of

  17. Efficacy of ultraviolet germicidal irradiation of upper-room air in inactivating airborne bacterial spores and mycobacteria in full-scale studies

    NASA Astrophysics Data System (ADS)

    Xu, Peng; Peccia, Jordan; Fabian, Patricia; Martyny, John W.; Fennelly, Kevin P.; Hernandez, Mark; Miller, Shelly L.

    The efficacy of ultraviolet germicidal irradiation (UVGI) for inactivating airborne bacterial spores and vegetative mycobacteria cells was evaluated under full-scale conditions. Airborne bacteria inactivation experiments were conducted in a test room (87 m 3), fitted with a modern UVGI system (216 W all lamps operating, average upper zone UV irradiance 42±19 μW cm -2) and maintained at 25°C and 50% relative humidity, at two ventilation rates (0 and 6 air changes per hour). Bacillus subtilis (spores), Mycobacterium parafortuitum, and Mycobacterium bovis BCG cells were aerosolized continuously into the room such that their numbers and physiologic state were comparable both with and without the UVGI and ventilation system operating. Air samples were collected using glass impingers (9 breathing-zone locations) and multi-stage impactors, and collected bacteria were quantified using direct microscopy and standard culturing assays. UVGI reduced the room-average concentration of culturable airborne bacteria between 46% and 80% for B. subtilis spores, between 83% and 98% for M. parafortuitum, and 96-97% for M. bovis BCG cells, depending on the ventilation rate. An additional set of experiments, in which M. parafortuitum was aerosolized into the test room and then allowed to decay under varying UVGI and ventilation rates, yielded an inactivation rate of 16±1.2 h -1 for the UVGI system, all lamps operating. The Z value (inactivation rate normalized to UVGI irradiance) was estimated to be 1.2±0.15×10 -3 cm 2 μW -1 s -1 for aerosolized M. parafortuitum at 50% relative humidity.

  18. Relationships between airborne fungal spore concentration of Cladosporium and the summer climate at two sites in Britain

    NASA Astrophysics Data System (ADS)

    Hollins, P. D.; Kettlewell, P. S.; Atkinson, M. D.; Stephenson, D. B.; Corden, J. M.; Millington, W. M.; Mullins, J.

    Cladosporium conidia have been shown to be important aeroallergens in many regions throughout the world, but annual spore concentrations vary considerably between years. Understanding these annual fluctuations may be of value in the clinical management of allergies. This study investigates the number of days in summer when spore concentration exceeds the allergenic threshold in relation to regional temperature and precipitation at two sites in England and Wales over 27 years. Results indicate that number of days in summer when the Cladosporium spores are above the allergenic concentration is positively correlated with regional temperature and negatively correlated with precipitation for both sites over the study period. Further analysis used a winter North Atlantic Oscillation index to explore the potential for long-range forecasting of the aeroallergen. For both spore measurement sites, a positive correlation exists between the winter North Atlantic Oscillation index and the number of days in summer above the allergenic threshold for Cladosporium spore concentration.

  19. Cytotoxic and genotoxic potencies of single and combined spore extracts of airborne OTA-producing and OTA-non-producing Aspergilli in Human lung A549 cells.

    PubMed

    Šegvić Klarić, Maja; Jakšić Despot, Daniela; Kopjar, Nevenka; Rašić, Dubravka; Kocsubé, Sándor; Varga, János; Peraica, Maja

    2015-10-01

    Aspergillus sclerotiorum (AS) is a well-known producer of ochratoxin A (OTA) while Aspergillus pseudoglaucus (AP) produces a wide range of extrolites with poorly investigated toxicity. These species are frequently co-occur in grain mill aeromycota. The aim of this study was to determine OTA levels in spore extracts using HPLC and immunoaffinity columns, and to examine the cytotoxicity of pure OTA, OTA-positive (AS-OTA(+)) and OTA-negative (AS-OTA(-)) spore extracts, as well as of AP spore extract, on human lung adenocarcinoma cells A549, individually and in combination, using a colorimetric MTT test (540nm). To establish which type of cell death predominated after treatments, a quantitative fluorescent assay with ethidium bromide and acridine orange was used, and the level of primary DNA damage in A549 cells was evaluated using the alkaline comet assay. OTA was detected in spore extracts (0.3-28µg/mL) of 3/6 of the AS strains, while none of the tested AP strains were able to produce OTA. Taking into account the maximum detected concentration of OTA in the spores, the daily intake of OTA by inhalation was calculated to be 1ng/kg body weight (b.w.), which is below the tolerable daily intake for OTA (17ng/kg b.w.). Using the MTT test, the following IC50 values were obtained: single OTA (53μg/mL); AS-OTA(+) (mass concentration 934μg/mL corresponds to 10.5μg/mL of OTA in spore extract); and 2126μg/mL for AP. The highest applied concentration of AS-OTA(-) spore extract (4940μg/mL) decreased cell viability by 30% and IC50 for the extract could not be determined. Single OTA and AS-OTA(+) and combinations (AP+AS-OTA(+) and AP+AS-OTA(-)) in subtoxic concentrations provoked significant primary DNA damage, apoptosis, and to a lesser extent, necrosis in A549 cells. Mixture of AP+AS-OTA(+) and AP+AS-OTA(-) in subtoxic concentrations showed dominant additive interactions. Despite the low calculated daily intake of OTA by inhalation, our results suggest that chronic exposure

  20. Back-trajectories show export of airborne fungal spores (Ganoderma sp.) from forests to agricultural and urban areas in England

    NASA Astrophysics Data System (ADS)

    Sadyś, M.; Skjøth, C. A.; Kennedy, R.

    2014-02-01

    We propose here the hypothesis that all of United Kingdom (UK) is likely to be affected by Ganoderma sp. spores, an important plant pathogen. We suggest that the main sources of this pathogen, which acts as a bioaerosol, are the widely scattered woodlands in the country, although remote sources must not be neglected. The hypothesis is based on related studies on bioaerosols and supported by new observations from a non-forest site and model calculations to support our hypothesis.

  1. Comparison of enzyme immunoassay–based assays for environmental Alternaria alternata

    PubMed Central

    Barnes, Charles; Portnoy, Jay; Sever, Michelle; Arbes, Samuel; Vaughn, Ben; Zeldin, Darryl C.

    2007-01-01

    Background Alternaria alternata–derived allergenic materials are causes of human disease. Several immunoassays exist to quantify these materials. Objective To compare methods for evaluating Alternaria content. Methods Four methods, including 1 monoclonal antibody (MAb)–based assay specific for recombinant Alt a 1, 1 MAb-based assay for chromatographically purified Alt a 1, 1 polyclonal antibody (PAb)–based assay for chromatographically purified Alt a 1, and 1 PAb-based assay for whole Alternaria extract, were evaluated. Environmental samples collected as part of the National Survey of Lead and Allergens in Housing were examined. Alternaria spore counts were determined in dust by observation. Results The MAb-based assay for recombinant Alt a 1 detected Alternaria in few samples (25%); the PAb-based assay for whole Alternaria proteins detected antigen in 97% of the samples. The PAb- and MAb-based assays for purified Alt a 1 detected antigen in 100% of the samples. There was a significant positive correlation between the 2 assays directed against purified Alt a 1. There was a positive correlation between the PAb-based assay for whole Alternaria and the PAb-based assay for Alt a 1. Nearly all the dust samples contained Alternaria spores, and there was a strong positive correlation between counts and all assays. Conclusion Because of the multifaceted nature of Alternaria, the disparities between methods for quantifying Alternaria, the cross-reactivity between fungal allergens, and the documented genetic promiscuity of this fungus, enzyme immunoassays using PAbs against a range of Alternaria proteins will probably produce the most reliable estimation of overall Alternaria exposure in house dust. PMID:17042141

  2. Optical pulling of airborne absorbing particles and smut spores over a meter-scale distance with negative photophoretic force

    SciTech Connect

    Lin, Jinda; Hart, Adam G.; Li, Yong-qing

    2015-04-27

    We demonstrate optical pulling of single light-absorbing particles and smut spores in air over a meter-scale distance using a single collimated laser beam based on negative photophoretic force. The micron-sized particles are pulled towards the light source at a constant speed of 1–10 cm/s in the optical pulling pipeline while undergoing transverse rotation at 0.2–10 kHz. The pulled particles can be manipulated and precisely positioned on the entrance window with an accuracy of ∼20 μm, and their chemical compositions can be characterized with micro-Raman spectroscopy.

  3. A year-round study on functional relationships of airborne fungi with meteorological factors

    NASA Astrophysics Data System (ADS)

    Li, De-Wei; Kendrick, Bryce

    1995-06-01

    Air sampling was conducted in Waterloo, Canada throughout 1992. Functional relationships between aeromycota and meteorological factors were analysed. The meteorological factors were, in descending order of importance: mean temperature, minimum temperature, maximum temperature, mean wind speed, relative humidity (RH), rain, maximum wind speed and snow. The most important airborne fungal propagules in descending order were: total fungal spores, unidentified Ascomycetes, Cladosporium, Coprinus, unidentified Basidiomycetes, Alternaria and unidentified fungi. Most airborne fungal taxa had highly significant relationship with temperature, but Aspergillus/Penicillium, hyphal fragments and Epicoccum did not. Epicoccum and hyphal fragments were positively associated with wind speed. In comparison with other airborne fungal taxa, Leptosphaeria and unidentified Ascomycetes were more closely correlated with rain and RH during the growing season.

  4. Pulmonary hypersensitivity to Alternaria and Aspergillus in baker's asthma.

    PubMed

    Klaustermeyer, W B; Bardana, E J; Hale, F C

    1977-05-01

    In two cases of baker's asthma pulmonary hypersensitivity was found to the fungi Alternaria and Aspergillus. Provocative bronchial challenge revealed a dual response; an immediate and an Arthus type hypersensitivity to Aspergillus in the first case. A primary binding assay revealed high titres of anti-Aspergillus antibody in the serum. In the second case intradermal and bronchial challenge suggested an immediate type I hypersensitivity response to Alternaria. The suspected organisms were present in the room air of the bakeries. It is suggested that an immunological response to these airborne fungi may have contributed to the pathogenesis of baker's asthma. PMID:561668

  5. [Airborne fungal community composition in indoor environments in Beijing].

    PubMed

    Fang, Zhi-guo; Ouyang, Zhi-yun; Liu, Peng; Sun, Li; Wang, Xiao-yong

    2013-05-01

    Indoor environmental quality has significant effects on human health. It is reported that adults in China spent about 80%-90% of their time in indoor environments, and a number of physically handicapped people such as the elderly and infants stayed in the room even up to 95% of their total time. Moreover, air conditioner in indoor environments becomes more and more important in modern life, and a closed circulatory system can be formed among human body, room and air conditioner in indoor environments with an air conditioner, which can make the microbes such as bacteria, viruses and mold indoors propagate rapidly or abundantly. Therefore, studies on the microbial pollution in the air at places such as mall, classroom, office, and family home have been the research hotspots recently. In the present study, the community composition and concentration variation pattern of airborne fungi were investigated from Nov 2009 to Oct 2010 in 31 family homes with children in Beijing. Results showed that 24 generas of airborne fungi in family homes were identified from 225 isolates. The most common fungi were Penicillium, Cladosporium, Aspergillus, Alternaria and Phoma. The frequency of Penicillium, Cladosporium, Aspergillus, Alternaria and Monilia was much higher than those of other fungal genera in family home, and the frequency of Penicillium was more than 90%. As for the concentration percentage, airborne fungi with most high concentrations were Penicillium, Cladosporium, Aspergillus, No-sporing, and Alternaria, and totally accounted for more than 65.0%. Penicillium contributed to 32.2% of the total airborne fungi in family homes. In the 31 family homes selected, the fungal concentration in the air ranged from 62-3 498 CFU x m(-3), and the mean concentration was 837 CFU x m(-3). Seasonal variation pattern of total fungi, and Cladosporium, Aspergillus, Alternaria concentration was consistent, and the highest fungal concentration was observed in summer, followed by spring and

  6. Size-selective assessment of agricultural workers' personal exposure to airborne fungi and fungal fragments.

    PubMed

    Lee, Shu-An; Liao, Chien-Hua

    2014-01-01

    Fungi are ubiquitous agents that cause human respiratory diseases. Very few studies have size-selectively assessed farmers' exposure to fungi and fungal fragments in agricultural settings. In this study, a two-stage bio-aerosol cyclone personal sampler was employed to collect airborne fungi and fungal fragments size-selectively at corn, swine, poultry, and mushroom farms. The collected air samples were analyzed for culturable fungi, fungal spores, viable fungi and (1 → 3)-β-D-glucan. The results show that the median concentrations ranged from 3.2 × 10(5) to 1.3 × 10(8)spores/m(3) for total fungal spores, from 1.3 × 10(5) to 5.1 × 10(7)spores/m(3) for total viable fungi, from 1.9 × 10(3) to 1.5 × 10(7)CFU/m(3) for total culturable fungi, and from 4.3 × 10(3) to 2.4 × 10(6)pg/m(3) for total (1 → 3)-β-D-glucan. The aerodynamic sizes of most of the collected fungal contaminants were larger than 1.8 μm. Total (1 → 3)-β-D-glucan significantly correlated with total fungal spores (r = 0.65, p < 0.001), total viable fungi (r = 0.68, p < 0.001) and total culturable fungi (r = 0.72, p < 0.001). Total (1 → 3)-β-D-glucan significantly correlated with Aspergillus/Penicillium, Alternaria, and Cladosporium. Alternaria and Botrytis were also found to highly correlate with (1 → 3)-β-D-glucan at the size <1 μm, which was less than the expected spore sizes (the mean measured aerodynamic sizes were 18.5 μm for Alternaria and 6.1 μm for Botrytis); therefore, Alternaria and Botrytis might release small fragments that could enter the deep lung and cause respiratory diseases. PMID:23973538

  7. Alternaria alternata allergens: Markers of exposure, phylogeny and risk of fungi-induced respiratory allergy.

    PubMed

    Gabriel, Marta F; Postigo, Idoia; Tomaz, Cândida T; Martínez, Jorge

    2016-01-01

    Alternaria alternata spores are considered a well-known biological contaminant and a very common potent aeroallergen source that is found in environmental samples. The most intense exposure to A. alternata allergens is likely to occur outdoors; however, Alternaria and other allergenic fungi can colonize in indoor environments and thereby increase the fungal aeroallergen exposure levels. A consequence of human exposure to fungal aeroallergens, sensitization to A. alternata, has been unequivocally associated with increased asthma severity. Among allergenic proteins described in this fungal specie, the major allergen, Alt a 1, has been reported as the main elicitor of airborne allergies in patients affected by a mold allergy and considered a marker of primary sensitization to A. alternata. Moreover, A. alternata sensitization seems to be a triggering factor in the development of poly-sensitization, most likely because of the capability of A. alternata to produce, in addition to Alt a 1, a broad and complex array of cross-reactive allergens that present homologs in several other allergenic sources. The study and understanding of A. alternata allergen information may be the key to explaining why sensitization to A. alternata is a risk factor for asthma and also why the severity of asthma is associated to this mold. Compared to other common environmental allergenic sources, such as pollens and dust mites, fungi are reported to be neglected and underestimated. The rise of the A. alternata allergy has enabled more research into the role of this fungal specie and its allergenic components in the induction of IgE-mediated respiratory diseases. Indeed, recent research on the identification and characterization of A. alternata allergens has allowed for the consideration of new perspectives in the categorization of allergenic molds, assessment of exposure and diagnosis of fungi-induced allergies. PMID:26826364

  8. Immunotherapy with Alternaria alternata: present and future.

    PubMed

    Martínez-Cañavate Burgos, A; Valenzuela-Soria, A; Rojo-Hernández, A

    2007-01-01

    The prevalence of fungal allergies is greater than previously believed; consequently, such processes have been underestimated as potential causes of respiratory tract disease. Most patients sensitized to fungi exhibit perennial symptoms, though their intensity increases in the summer and autumn months. Skin reactions to the antigens of Alternaria alternata are associated with a high risk of allergic respiratory conditions in the presence of spores of this fungus -fundamentally in children and young adults- with a special form of presentation as life-threatening asthma. Very few controlled studies have examined the efficacy and safety of fungal extract immunotherapy -the main problem being the lack of standardized extracts for the diagnosis and treatment of such patients. In the year 2005 a tolerance study was made in children in relation to a depot extract containing the predominant antigen of Alternaria, with two different regimens (short and cluster). Tolerance was found to be good, with a 0.95 % incidence of local reactions and a 0.95 % incidence of grade 2 systemic reactions. Few studies involving sublingual immunotherapy have been conducted to date. PMID:18047818

  9. Clinical Characteristics of Alternaria Keratitis

    PubMed Central

    Lin, Hsin-Chiung; Chen, Phil Y. F.; Ma, David H. K.; Tan, Hsin-Yuan

    2014-01-01

    Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated. PMID:24778867

  10. Atmospheric mold spore counts in relation to meteorological parameters

    NASA Astrophysics Data System (ADS)

    Katial, R. K.; Zhang, Yiming; Jones, Richard H.; Dyer, Philip D.

    Fungal spore counts of Cladosporium, Alternaria, and Epicoccum were studied during 8 years in Denver, Colorado. Fungal spore counts were obtained daily during the pollinating season by a Rotorod sampler. Weather data were obtained from the National Climatic Data Center. Daily averages of temperature, relative humidity, daily precipitation, barometric pressure, and wind speed were studied. A time series analysis was performed on the data to mathematically model the spore counts in relation to weather parameters. Using SAS PROC ARIMA software, a regression analysis was performed, regressing the spore counts on the weather variables assuming an autoregressive moving average (ARMA) error structure. Cladosporium was found to be positively correlated (P<0.02) with average daily temperature, relative humidity, and negatively correlated with precipitation. Alternaria and Epicoccum did not show increased predictability with weather variables. A mathematical model was derived for Cladosporium spore counts using the annual seasonal cycle and significant weather variables. The model for Alternaria and Epicoccum incorporated the annual seasonal cycle. Fungal spore counts can be modeled by time series analysis and related to meteorological parameters controlling for seasonallity; this modeling can provide estimates of exposure to fungal aeroallergens.

  11. [Research of chemotaxis response of Botrytis cinerea and Alternaria panax on total ginsenosides].

    PubMed

    Chi, Kun; Xu, Yong-hua; Lei, Feng-jie; Yin, Min-jing; Wang, Zhuang; Zhang, Ai-hua; Zhang, Lian-xue

    2015-10-01

    In this paper, three kinds of chemotactic parameters (concentration, temperature and pH) were determined by plate assay and spore germination method to research the chemotactic response of Botrytis cinerea and Alternaria panax, and their spores on total ginsenosides. The results showed that Botrytis cinerea had strong chemotactic response at the mid-concentration of total ginsenosides (cultivation temperature was 20 degrees C and pH value was 6), and the data of chemotactic migration index (CMI) was 1.293 0, chemotactic growth rate (CGR) was 0.476 0, spore germination rate (SGR) was 53%, and dry weight of mycelial (DWM) was 0.452 6 g x L(-1); however, Alternaria panax had strong chemotactic response at the low-concentration of total ginsenosides (cultivation temperature was 25 degrees C and pH value was 6), and the data of chemotactic migration index (CMI) was 1.235 4, chemotactic growth rate (CGR) was 0.537 0, spore germination rate (SGR) was 67%, and dry weight of mycelial (DWM) was 0.494 8 g x L(-1). The results indicated that the low and middle concentration (2, 20 mg x L(-1)) of total ginsenosides had significant promoting effect on chemotactic response of these two pathogens, and the spore germination, mycelial growth rate, dry weight of mycelial of them were also significantly improved by this chemotactic response, whereas it decreased as the increase of total ginsenosides concentration. PMID:26975095

  12. Characterization of Alternaria strains from Argentinean blueberry, tomato, walnut and wheat.

    PubMed

    Andersen, Birgitte; Nielsen, Kristian F; Fernández Pinto, Virginia; Patriarca, Andrea

    2015-03-01

    Alternaria species have the ability to produce a variety of secondary metabolite, which plays important roles in food safety. Argentina is the second largest exporter of fresh and processed food products to Europe, however, few studies on Alternaria mycotoxins and other bioactive secondary metabolites have been carried out on Argentinean cereals, fruit and vegetables. Knowing the full chemical potential and the distribution of Alternaria spp. on crops, it is necessary to establish a toxicological risk assessment for food products for human consumption. In the present study, 87 Alternaria strains from different substrates (tomato, wheat, blueberries and walnuts) were characterized according to morphology and metabolite production. Aggressive dereplication (accurate mass, isotopic patterns and lists of all described compounds from Alternaria) was used for high-throughput evaluation of the chemical potential. Four strains belonged to the Alternaria infectoria sp.-grp., 6 to the Alternaria arborescens sp.-grp., 6 showed a sporulation pattern similar to that of "M" according to Simmons, 1 to that of Alternaria vaccinii, and the remaining 70 constituted a diverse group belonging to morphological groups "G" and "H". The cluster analysis yielded 16 almost identical dendrograms and grouped the Alternaria strains into four clusters and 11 singletons and outlier groups. The chemical analysis showed that AOH and AME were the most common metabolites produced, followed by TEN, ALXs and TeA. The A. infectoria sp.-grp. had no metabolites in common with the rest of the strains. Several secondary metabolites isolated from large-spored Alternaria species or other fungal genera were detected, such as dehydrocurvularin, pyrenochaetic acid and alternarienonic acid. The strains isolated from tomato produced lower amounts of metabolites than strains from blueberries, walnut and wheat, although individual strains from tomato produced the highest amount of some metabolites. The A

  13. Correlation of spring spore concentrations and meteorological conditions in Tulsa, Oklahoma

    NASA Astrophysics Data System (ADS)

    Troutt, C.; Levetin, E.

    Different spore types are abundant in the atmosphere depending on the weather conditions. Ascospores generally follow precipitation, while spore types such as Alternaria and Cladosporium are abundant in dry conditions. This project attempted to correlate fungal spore concentrations with meteorological data from Tulsa, Oklahoma during May 1998 and May 1999. Air samples were collected and analyzed by the 12-traverse method. The spore types included were Cladosporium, Alternaria, Epicoccum, Curvularia, Pithomyces, Drechslera, smut spores, ascospores, basidiospores, and other spores. Weather variables included precipitation levels, temperature, dew point, air pressure, wind speed, wind direction and wind gusts. There were over 242.57 mm of rainfall in May 1999 and only 64.01 mm in May 1998. The most abundant spore types during May 1998 and May 1999 were Cladosporium, ascospores, and basidiospores. Results showed that there were significant differences in the dry-air spora between May 1998 and May 1999. There were twice as many Cladosporium in May 1998 as in May 1999; both ascospores and basidiospores showed little change. Multiple regression analysis was used to determine which meteorological variables influenced spore concentrations. Results showed that there was no single model for all spore types. Different combinations of factors were predictors of concentration for the various fungi examined; however, temperature and dew point seemed to be the most important meteorological factors.

  14. The Fungal Spores Survival Under the Low-Temperature Plasma

    NASA Astrophysics Data System (ADS)

    Soušková, Hana; Scholtz, V.; Julák, J.; Savická, D.

    This paper presents an experimental apparatus for the decontamination and sterilization of water suspension of fungal spores. The fungicidal effect of stabilized positive and negative corona discharges on four fungal species Aspergillus oryzae, Clacosporium sphaerospermum, Penicillium crustosum and Alternaria sp. was studied. Simultaneously, the slower growing of exposed fungal spores was observed. The obtained results are substantially different in comparison with those of the analogous experiments performed with bacteria. It may be concluded that fungi are more resistant to the low-temperature plasma.

  15. Lyophilized spore dispenser

    NASA Technical Reports Server (NTRS)

    Jessup, A. D. (Inventor)

    1973-01-01

    A lyophilized spore dispenser is provided which produces a finely divided, monoparticulate cloud of bacterial spores. The spores are contained within a tightly sealed chamber, and a turbulator orifice connected to an air supply source provides a jet of air which stirs up the spores and causes the spores to be suspended in eddy currents within the chamber. This air jet also produces a positive pressure within the chamber which forces the spores out of an injection orifice.

  16. Spore Resistance Properties.

    PubMed

    Setlow, Peter

    2014-10-01

    Spores of various Bacillus and Clostridium species are among the most resistant life forms known. Since the spores of some species are causative agents of much food spoilage, food poisoning, and human disease, and the spores of Bacillus anthracis are a major bioweapon, there is much interest in the mechanisms of spore resistance and how these spores can be killed. This article will discuss the factors involved in spore resistance to agents such as wet and dry heat, desiccation, UV and γ-radiation, enzymes that hydrolyze bacterial cell walls, and a variety of toxic chemicals, including genotoxic agents, oxidizing agents, aldehydes, acid, and alkali. These resistance factors include the outer layers of the spore, such as the thick proteinaceous coat that detoxifies reactive chemicals; the relatively impermeable inner spore membrane that restricts access of toxic chemicals to the spore core containing the spore's DNA and most enzymes; the low water content and high level of dipicolinic acid in the spore core that protect core macromolecules from the effects of heat and desiccation; the saturation of spore DNA with a novel group of proteins that protect the DNA against heat, genotoxic chemicals, and radiation; and the repair of radiation damage to DNA when spores germinate and return to life. Despite their extreme resistance, spores can be killed, including by damage to DNA, crucial spore proteins, the spore's inner membrane, and one or more components of the spore germination apparatus. PMID:26104355

  17. Comparison of pathogenicity of Alternaria pellucida and Curvularia lunata on weed Echinochloa species.

    PubMed

    Reza, Mohammad; Motlagh, Safari

    2015-07-01

    Echinochloa spp. are the most important weeds in rice fields. In this research Curvularia lunata and Alternaria pellucida were isolated from these weeds and their pathogenicity effects were compared on these weeds and five rice cultivars in a completely random design with three replications in greenhouse conditions. Fungi were inoculated on weeds and rice cultivars, using spore suspension consisting of 10' spore ml(-1) of distilled water. Results indicated significant effect of Curvularia lunata and Alternaria pellucida on Echinochloa oryzicola and E. crus-galli. In the present study, effect of C. lunata on fresh weight, dry weight and height of Echinochloa species based on variance analysis table, a significant reaction was observed for height and fresh weight, but for dry weight reaction was not significant. The effect of A. pellucida on fresh weight, dry weight and height of Echinochloa species based on variance analysis table, a significant reaction was observed for all the three traits. Also, rice cultivars did not show any significant reaction to C. lunata and A. pellucida. The results showed that in comparison between effect of Curvularia lunata and Alternaria pellucida on Echinochloa spp., disease rating caused by A. pellucida on E. oryzicola and E. crusalli was more than disease rating caused by C. lunata and these species of weed were more susceptible to A. pellucida. However, A. alternata can be considered as a better promising bioherbicide to control Echinochloa spp. PMID:26364476

  18. Spores Disperse, Too!

    ERIC Educational Resources Information Center

    Schumann, Donna N.

    1981-01-01

    Suggests the use of spores and spore-producing structures to show adaptations facilitating spore dispersal and dispersal to favorable environments. Describes several activities using horsetails, ferns, and mosses. Lists five safety factors related to use of mold spores in the classroom. (DS)

  19. Analysis of Bacillus globigii spores by CE.

    PubMed

    Chichester, Kimberly D; Silcott, David B; Colyer, Christa L

    2008-02-01

    It is imperative in today's world that harmful airborne or solution-based microbes can be detected quickly and efficiently. Bacillus globigii (Bg) spores are used as a simulant for Bacillus anthracis (Ba) due to their similar shape, size, and cellular makeup. The utility of CE to separate and detect low levels of Bg spore concentrations will be evaluated. To differentiate spores from background particulates, several dyes, including fluorescamine, C-10, NN-127, Red-1c, and indocyanine green (ICG), were utilized as noncovalent labels for proteins on the Bg spore surface, as well as for HSA and homoserine standards. On-column labeling, with dye present in the running buffer, was utilized to obtain greater sensitivity and better separation. CE with LIF detection enables interactions between the dye and spore surface proteins to be observed, with enhanced fluorescence occurring upon binding of the dye to surface protein. Resulting electropherograms showed unique fingerprints for each dye with Bg spores. Migration times were under 10 min for all dye-spore complexes, with net mobilities ranging from 3.5x10(-4) to 6.9x10(-4) cm(2) V(-1) s(-1), and calibration curves yielded correlation coefficients of 0.98 or better for four of the dyes studied. PMID:18203249

  20. Source strength of fungal spore aerosolization from moldy building material

    NASA Astrophysics Data System (ADS)

    Górny, Rafał L.; Reponen, Tiina; Grinshpun, Sergey A.; Willeke, Klaus

    The release of Aspergillus versicolor, Cladosporium cladosporioides, and Penicillium melinii spores from agar and ceiling tile surfaces was tested under different controlled environmental conditions using a newly designed and constructed aerosolization chamber. This study revealed that all the investigated parameters, such as fungal species, air velocity above the surface, texture of the surface, and vibration of contaminated material, affected the fungal spore release. It was found that typical indoor air currents can release up to 200 spores cm -2 from surfaces with fungal spores during 30-min experiments. The release of fungal spores from smooth agar surfaces was found to be inadequate for accurately predicting the emission from rough ceiling tile surfaces because the air turbulence increases the spore release from a rough surface. A vibration at a frequency of 1 Hz at a power level of 14 W resulted in a significant increase in the spore release rate. The release appears to depend on the morphology of the fungal colonies grown on ceiling tile surfaces including the thickness of conidiophores, the length of spore chains, and the shape of spores. The spores were found to be released continuously during each 30-min experiment. However, the release rate was usually highest during the first few minutes of exposure to air currents and mechanical vibration. About 71-88% of the spores released during a 30-min interval became airborne during the first 10 min.

  1. Elevated Atmospheric Carbon Dioxide Concentrations Amplify Alternaria alternata Sporulation and Total Antigen Production

    PubMed Central

    Wolf, Julie; O’Neill, Nichole R.; Rogers, Christine A.; Muilenberg, Michael L.; Ziska, Lewis H.

    2010-01-01

    Background Although the effect of elevated carbon dioxide (CO2) concentration on pollen production has been established in some plant species, impacts on fungal sporulation and antigen production have not been elucidated. Objective Our purpose was to examine the effects of rising atmospheric CO2 concentrations on the quantity and quality of fungal spores produced on timothy (Phleum pratense) leaves. Methods Timothy plants were grown at four CO2 concentrations (300, 400, 500, and 600 μmol/mol). Leaves were used as growth substrate for Alternaria alternata and Cladosporium phlei. The spore abundance produced by both fungi, as well as the size (microscopy) and antigenic protein content (ELISA) of A. alternata, were quantified. Results Leaf carbon-to-nitrogen ratio was greater at 500 and 600 μmol/mol, and leaf biomass was greater at 600 μmol/mol than at the lower CO2 concentrations. Leaf carbon-to-nitrogen ratio was positively correlated with A. alternata spore production per gram of leaf but negatively correlated with antigenic protein content per spore. At 500 and 600 μmol/mol CO2 concentrations, A. alternata produced nearly three times the number of spores and more than twice the total antigenic protein per plant than at lower concentrations. C. phlei spore production was positively correlated with leaf carbon-to-nitrogen ratio, but overall spore production was much lower than in A. alternata, and total per-plant production did not vary among CO2 concentrations. Conclusions Elevated CO2 concentrations often increase plant leaf biomass and carbon-to-nitrogen ratio. Here we demonstrate for the first time that these leaf changes are associated with increased spore production by A. alternata, a ubiquitous allergenic fungus. This response may contribute to the increasing prevalence of allergies and asthma. PMID:20462828

  2. Ungual and cutaneous phaeohyphomycosis caused by Alternaria alternata and Alternaria chlamydospora.

    PubMed

    Singh, S M; Naidu, J; Pouranik, M

    1990-01-01

    Two cases of ungual and cutaneous phaeohyphomycosis caused by Alternaria alternata and Alternaria chlamydospora are described. Oxiconazole and amorolfine were most effective in vitro against A. alternata and A. chlamydospora respectively. This is the first report of A. chlamydospora as an opportunistic pathogen of skin. PMID:2148601

  3. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities.

    PubMed

    Lou, Jingfeng; Yu, Ruiting; Wang, Xiaohan; Mao, Ziling; Fu, Linyun; Liu, Yang; Zhou, Ligang

    2016-01-01

    One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75μg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27μg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18μg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17μg/mL and 74.62μg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms. PMID:26887231

  4. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities

    PubMed Central

    Lou, Jingfeng; Yu, Ruiting; Wang, Xiaohan; Mao, Ziling; Fu, Linyun; Liu, Yang; Zhou, Ligang

    2016-01-01

    One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75 μg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27 μg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18 μg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17 μg/mL and 74.62 μg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms. PMID:26887231

  5. MODELING OF CEREAL RUST EPIDEMICS IN RUSSIA: EMISSION OF SPORES INTO THE AIR FROM INFECTED CROPS AND FORMATION OF SPORE CLOUDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Special isolating chambers were used to estimate quantity of spores of Puccinia triticina, P. graminis and P. striiformis in the field intact plants. Spore outflow from infected fields was estimated using ground and airborne impactors. Simultaneous factors that could affect emission and transfer of ...

  6. Alternaria keratitis after deep anterior lamellar keratoplasty.

    PubMed

    Naik, Mekhla; Mohd Shahbaaz; Sheth, Jay; Sunderamoorthy, S K

    2014-01-01

    To describe a case of Alternaria keratitis in a 30-year-old male patient who presented with bilateral vascularised central corneal opacity and underwent deep anterior lamellar keratoplasty (DALK) in the left eye. Patient was treated for recurrent epithelial defect with a bandage contact lens in the follow-up visits after DALK. Subsequently, patient presented with pigmented fungal keratitis, which on culture examination of the corneal scrapping demonstrated Alternaria species. Patient had to undergo a repeat DALK as the keratitis did not resolve with medical therapy alone. Patient did not have a recurrence for 11 months following the regraft. This case report highlights the importance of considering the Alternaria species as a possibile cause of non-resolving fungal keratitis after DALK. PMID:24669155

  7. Significance of air humidity and air velocity for fungal spore release into the air

    NASA Astrophysics Data System (ADS)

    Pasanen, A.-L.; Pasanen, P.; Jantunen, M. J.; Kalliokoski, P.

    Our previous field studies have shown that the presence of molds in buildings does not necessarily mean elevated airborne spore counts. Therefore, we investigated the release of fungal spores from cultures of Aspergillus fumigatus, Penicillium sp. and Cladosporium sp. at different air velocities and air humidities. Spores of A. fumigatus and Penicillium sp. were released from conidiophores already at air velocity of 0.5 ms -1, whereas Cladosporium spores required at least a velocity of 1.0 ms -1. Airborne spore counts of A. fumigatus and Penicillium sp. were usually higher in dry than moist air, being minimal at relative humidities (r.h.) above 70%, while the effect of r.h. on the release of Cladosporium sp. was ambivalent. The geometric mean diameter of released spores increased when the r.h. exceeded a certain level which depends on fungal genus. Thus, spores of all three fungi were hygroscopic but the hygroscopicity of various spores appeared at different r.h.-ranges. This study indicates that spore release is controlled by external factors and depends on fungal genus which can be one reason for considerable variation of airborne spore counts in buildings with mold problems.

  8. Fungal spores are transported long distances in smoke from biomass fires

    NASA Astrophysics Data System (ADS)

    Mims, Sarah A.; Mims, Forrest M.

    Viable fungal spores are present in smoke from distant biomass fires. This finding has potentially important implications for prescribed burning, agricultural management and public health. While attempting to find fungal spores in dust blown from China to Texas, one of us (S.A.M.) discovered that smoke from Yucatan contains viable bacteria and fungal spores, including the genera Alternaria, Cladosporium, Fusariella and Curvularia. There was a high correlation ( r2=0.78) of spores and coarse carbon particles collected on microscope slides during 13 days of the 2002 smoke season. To eliminate possible contamination by local spores, an air sampler was flown from a kite at a Texas Gulf Coast beach during and after the 2003 smoke season on days when the NOAA back trajectory showed air arriving from Yucatan. Fifty-two spores and 19 coarse black carbon particles (>2.5 μm) were collected during a 30-min kite flight on the smoke day and 12 spores and four carbons on the day without smoke. We have found spores in smoke from an Arizona forest fire and in Asian smoke at Mauna Loa Observatory, Hawaii. We have tested these findings by burning dried grass, leaves, twigs and flood detritus. The smoke from all test fires contained many spores.

  9. Hydrazine inactivates bacillus spores

    NASA Technical Reports Server (NTRS)

    Schubert, Wayne; Plett, G. A.; Yavrouian, A. H.; Barengoltz, J.

    2005-01-01

    Planetary Protection places requirements on the maximum number of viable bacterial spores that may be delivered by a spacecraft to another solar system body. Therefore, for such space missions, the spores that may be found in hydrazine are of concern. A proposed change in processing procedures that eliminated a 0.2 um filtration step propmpted this study to ensure microbial contamination issue existed, especially since no information was found in the literature to substantiate bacterial spore inactivation by hydrazine.

  10. Experiments with Biocontrol of Alternaria alternata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A biocontrol yeast (WRL-76) developed by USDA-ARS at the Western Regional Research lab was evaluated for control of Alternaria alternata on pistachio. The experiment was conducted over a four year period in a Madera Co., CA orchard. Counts of damaged vs. intact fruit clusters were taken on 100 contr...

  11. Cryopreservation of fern spores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spore banks for ferns are analogous to seed banks for angiosperms and provide a promising ex situ conservation tool because large quantities of germplasm with high genetic variation can be conserved in a small space with low economic and technical costs. Ferns produce two types of spores with very ...

  12. Mushrooms as Rainmakers: How Spores Act as Nuclei for Raindrops.

    PubMed

    Hassett, Maribeth O; Fischer, Mark W F; Money, Nicholas P

    2015-01-01

    Millions of tons of fungal spores are dispersed in the atmosphere every year. These living cells, along with plant spores and pollen grains, may act as nuclei for condensation of water in clouds. Basidiospores released by mushrooms form a significant proportion of these aerosols, particularly above tropical forests. Mushroom spores are discharged from gills by the rapid displacement of a droplet of fluid on the cell surface. This droplet is formed by the condensation of water on the spore surface stimulated by the secretion of mannitol and other hygroscopic sugars. This fluid is carried with the spore during discharge, but evaporates once the spore is airborne. Using environmental electron microscopy, we have demonstrated that droplets reform on spores in humid air. The kinetics of this process suggest that basidiospores are especially effective as nuclei for the formation of large water drops in clouds. Through this mechanism, mushroom spores may promote rainfall in ecosystems that support large populations of ectomycorrhizal and saprotrophic basidiomycetes. Our research heightens interest in the global significance of the fungi and raises additional concerns about the sustainability of forests that depend on heavy precipitation. PMID:26509436

  13. Mushrooms as Rainmakers: How Spores Act as Nuclei for Raindrops

    PubMed Central

    2015-01-01

    Millions of tons of fungal spores are dispersed in the atmosphere every year. These living cells, along with plant spores and pollen grains, may act as nuclei for condensation of water in clouds. Basidiospores released by mushrooms form a significant proportion of these aerosols, particularly above tropical forests. Mushroom spores are discharged from gills by the rapid displacement of a droplet of fluid on the cell surface. This droplet is formed by the condensation of water on the spore surface stimulated by the secretion of mannitol and other hygroscopic sugars. This fluid is carried with the spore during discharge, but evaporates once the spore is airborne. Using environmental electron microscopy, we have demonstrated that droplets reform on spores in humid air. The kinetics of this process suggest that basidiospores are especially effective as nuclei for the formation of large water drops in clouds. Through this mechanism, mushroom spores may promote rainfall in ecosystems that support large populations of ectomycorrhizal and saprotrophic basidiomycetes. Our research heightens interest in the global significance of the fungi and raises additional concerns about the sustainability of forests that depend on heavy precipitation. PMID:26509436

  14. A polyphasic approach for the characterization of endophytic Alternaria strains isolated from grapevines.

    PubMed

    Polizzotto, Rachele; Andersen, Birgitte; Martini, Marta; Grisan, Simone; Assante, Gemma; Musetti, Rita

    2012-01-01

    A polyphasic approach was set up and applied to characterize 20 fungal endophytes belonging to the genus Alternaria, recovered from grapevine in different Italian regions. Morphological, microscopical, molecular and chemical investigations were performed and the obtained results were combined in a pooled cluster analysis. Following morphological analyses, all strains were grouped according to their three-dimensional sporulation pattern on PCA and to the colony characteristics on different substrates. After DNA extraction, all strains were analyzed by RAPD-PCR and the resulting profiles were subjected to cluster analysis. The metabolites extracted from the 20 Alternaria endophytes were analyzed by a HPLC and the resulting metabolite profiles were subjected to multivariate statistic analyses. In comparison with reference 'small-spored' Alternaria species, the 20 strains were segregated into two morphological groups: one belonging to the A. arborescens species-group and a second to the A. tenuissima species-group. RAPD analysis also showed that grapevine endophytes belonged to either the A. arborescens or the A. tenuissima species-group and that they were molecularly distinct from strains belonging to A. alternata. Chemotaxonomy gave the same grouping: the grapevine endophytic strains belong to A. arborescens or A. tenuissima species-groups producing known metabolites typical of these species-groups. Interestingly, the 20 grapevine endophytes were able to produce also a number of unknown metabolites, whose characterization could be useful for a more precise segregation of the two species-groups. The results show how complementary morphological, molecular and chemical data can clarify relationships among endophyte species-groups of low morphological divergence. PMID:22123507

  15. Comparative Genomics of Pathogens Causing Brown Spot Disease of Tobacco: Alternaria longipes and Alternaria alternata

    PubMed Central

    Wan, Wenting; Long, Ni; Zhang, Jing; Tan, Yuntao; Duan, Shengchang; Zeng, Yan; Dong, Yang

    2016-01-01

    The genus Alternaria is a group of infectious/contagious pathogenic fungi that not only invade a wide range of crops but also induce severe allergic reactions in a part of the human population. In this study, two strains Alternaria longipes cx1 and Alternaria alternata cx2 were isolated from different brown spot lesions on infected tobacco leaves. Their complete genomes were sequenced, de novo assembled, and comparatively analyzed. Phylogenetic analysis revealed that A. longipes cx1 and A. alternata cx2 diverged 3.3 million years ago, indicating a recent event of speciation. Seventeen non-ribosomal peptide synthetase (NRPS) genes and 13 polyketide synthase (PKS) genes in A. longipes cx1 and 13 NRPS genes and 12 PKS genes in A. alternata cx2 were identified in these two strains. Some of these genes were predicted to participate in the synthesis of non-host specific toxins (non-HSTs), such as tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME). By comparative genome analysis, we uncovered that A. longipes cx1 had more genes putatively involved in pathogen-plant interaction, more carbohydrate-degrading enzymes and more secreted proteins than A. alternata cx2. In summary, our results demonstrate the genomic distinction between A. longipes cx1 and A. altenata cx2. They will not only improve the understanding of the phylogenetic relationship among genus Alternaria, but more importantly provide valuable genomic resources for the investigation of plant-pathogen interaction. PMID:27159564

  16. Comparative Genomics of Pathogens Causing Brown Spot Disease of Tobacco: Alternaria longipes and Alternaria alternata.

    PubMed

    Hou, Yujie; Ma, Xiao; Wan, Wenting; Long, Ni; Zhang, Jing; Tan, Yuntao; Duan, Shengchang; Zeng, Yan; Dong, Yang

    2016-01-01

    The genus Alternaria is a group of infectious/contagious pathogenic fungi that not only invade a wide range of crops but also induce severe allergic reactions in a part of the human population. In this study, two strains Alternaria longipes cx1 and Alternaria alternata cx2 were isolated from different brown spot lesions on infected tobacco leaves. Their complete genomes were sequenced, de novo assembled, and comparatively analyzed. Phylogenetic analysis revealed that A. longipes cx1 and A. alternata cx2 diverged 3.3 million years ago, indicating a recent event of speciation. Seventeen non-ribosomal peptide synthetase (NRPS) genes and 13 polyketide synthase (PKS) genes in A. longipes cx1 and 13 NRPS genes and 12 PKS genes in A. alternata cx2 were identified in these two strains. Some of these genes were predicted to participate in the synthesis of non-host specific toxins (non-HSTs), such as tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME). By comparative genome analysis, we uncovered that A. longipes cx1 had more genes putatively involved in pathogen-plant interaction, more carbohydrate-degrading enzymes and more secreted proteins than A. alternata cx2. In summary, our results demonstrate the genomic distinction between A. longipes cx1 and A. altenata cx2. They will not only improve the understanding of the phylogenetic relationship among genus Alternaria, but more importantly provide valuable genomic resources for the investigation of plant-pathogen interaction. PMID:27159564

  17. Alternaria in Food: Ecophysiology, Mycotoxin Production and Toxicology

    PubMed Central

    Patriarca, Andrea; Magan, Naresh

    2015-01-01

    Alternaria species are common saprophytes or pathogens of a wide range of plants pre- and post-harvest. This review considers the relative importance of Alternaria species, their ecology, competitiveness, production of mycotoxins and the prevalence of the predominant mycotoxins in different food products. The available toxicity data on these toxins and the potential future impacts of Alternaria species and their toxicity in food products pre- and post-harvest are discussed. The growth of Alternaria species is influenced by interacting abiotic factors, especially water activity (aw), temperature and pH. The boundary conditions which allow growth and toxin production have been identified in relation to different matrices including cereal grain, sorghum, cottonseed, tomato, and soya beans. The competitiveness of Alternaria species is related to their water stress tolerance, hydrolytic enzyme production and ability to produce mycotoxins. The relationship between A. tenuissima and other phyllosphere fungi has been examined and the relative competitiveness determined using both an Index of Dominance (ID) and the Niche Overlap Index (NOI) based on carbon-utilisation patterns. The toxicology of some of the Alternaria mycotoxins have been studied; however, some data are still lacking. The isolation of Alternaria toxins in different food products including processed products is reviewed. The future implications of Alternaria colonization/infection and the role of their mycotoxins in food production chains pre- and post-harvest are discussed. PMID:26190916

  18. Alternaria in Food: Ecophysiology, Mycotoxin Production and Toxicology.

    PubMed

    Lee, Hyang Burm; Patriarca, Andrea; Magan, Naresh

    2015-06-01

    Alternaria species are common saprophytes or pathogens of a wide range of plants pre- and post-harvest. This review considers the relative importance of Alternaria species, their ecology, competitiveness, production of mycotoxins and the prevalence of the predominant mycotoxins in different food products. The available toxicity data on these toxins and the potential future impacts of Alternaria species and their toxicity in food products pre- and post-harvest are discussed. The growth of Alternaria species is influenced by interacting abiotic factors, especially water activity (aw), temperature and pH. The boundary conditions which allow growth and toxin production have been identified in relation to different matrices including cereal grain, sorghum, cottonseed, tomato, and soya beans. The competitiveness of Alternaria species is related to their water stress tolerance, hydrolytic enzyme production and ability to produce mycotoxins. The relationship between A. tenuissima and other phyllosphere fungi has been examined and the relative competitiveness determined using both an Index of Dominance (ID) and the Niche Overlap Index (NOI) based on carbon-utilisation patterns. The toxicology of some of the Alternaria mycotoxins have been studied; however, some data are still lacking. The isolation of Alternaria toxins in different food products including processed products is reviewed. The future implications of Alternaria colonization/infection and the role of their mycotoxins in food production chains pre- and post-harvest are discussed. PMID:26190916

  19. 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...

  20. Fungicidal activity of silver nanoparticles against Alternaria brassicicola

    NASA Astrophysics Data System (ADS)

    Gupta, Deepika; Chauhan, Pratima

    2016-04-01

    This work highlighted the fungicidal properties of silver nanoparticles against Alternaria brassicicola. Alternaria brassicicola causes Black spot of Cauliflower, radish, cabbage, kale which results in sever agricultural loss. We treat the synthesised silver nanoparticles (AgNPs) of 10, 25, 50, 100 and 110 ppm concentrations against Alternaria brassicicola on PDA containing Petri dish. We calculated inhibitory rate (%) in order to evaluate the antifungal efficacy of silver nanoparticles against pathogens. Treatment with 100ppm AgNPs resulted in maximum inhibition of Alternaria brassicicola i.e.92.2%. 110ppm of AgNPS also shows the same result, therefore 100ppm AgNPs was treated as optimize concentration. AgNPs effectively inhibited the growth of a Alternaria brassicicola, which suggests that AgNPs could be used as fungicide in plant disease management. Further research and development are necessary to translate this technology into plant disease management strategies.

  1. Walking and jumping spores

    NASA Astrophysics Data System (ADS)

    Marmottant, Philippe

    2012-02-01

    The Equisetum plants, more commonly called ``horsetail,'' emit 50-microns spores that are spherical in shape and present four hygroscopic arms. Under high humidity, the arms are retracted. But under lower humidity, less than 70%, the four arms deploy beautifully. With time-lapse image recordings, we show that under repeated cycles of dry and high humidity, the spores behave as random walkers, since they move by about their size in a different direction at every cycle. The process is apparently stochastic because of the complex shape of the arms and hysteretic friction of the arms on the ground. For some spores, a decrease in humidity level results in very fast jumps, the spores taking off at a typical velocity of a meter per second, as recorded on high-speed camera. With these jumps, they reach centimetric elevations, much larger than their size. The physical mechanism at the root of these ``Levy-flight'' jumps is still under investigation. The walking and jumping phenomena thus provide motility, which we believe is helpful for the understanding of the biological dispersion of the spores. It could also bring biomimetic inspiration to engineer new motile elastic structures.

  2. Epicoccum allergy: skin reaction patterns and spore/mycelium disparities recognized by IgG and IgE ELISA inhibition.

    PubMed

    Portnoy, J; Chapman, J; Burge, H; Muilenberg, M; Solomon, W

    1987-07-01

    Comparable degrees of skin reactivity were observed towards spore and mycelium extracts from two isolates of Epicoccum and to one preparation of Alternaria in 35 rural and 120 university patients. The best experimental extracts detected Epicoccum sensitivity in 70% of the group tested while the commercial extract detected sensitivity in only 6%. Skin reaction correlations were greatest within isolates (eg, spore-A/mycelium-A), then for specific fungus parts (eg, spore-A/spore-B), then between isolates and parts (spore-A/mycelium-B). High correlations were found between individual IgG and IgE ELISA values for all antigens using serum from Epicoccum skin-reactive patients. ELISA inhibition results suggested that significant cross-reactivity exists between Epicoccum and Alternaria antigens recognized by IgG but not by IgE. ELISA inhibition cross-reaction patterns among Epicoccum antigens were comparable to skin reactions while IgG patterns showed little variability. Further characterization of spore/mycelium and interstrain recognition patterns among different immunoglobulin isotypes will be necessary before complete standardization of extracts from different parts of fungi will be possible. The use of spore material for skin testing and treatment of Epicoccum sensitivity appears to be both premature and unnecessary at this time. PMID:3605796

  3. Clostridium difficile spore biology: sporulation, germination, and spore structural proteins

    PubMed Central

    Paredes-Sabja, Daniel; Shen, Aimee; Sorg, Joseph A.

    2014-01-01

    Clostridium difficile is a Gram-positive, spore-forming obligate anaerobe and a major nosocomial pathogen of world-wide concern. Due to its strict anaerobic requirements, the infectious and transmissible morphotype is the dormant spore. In susceptible patients, C. difficile spores germinate in the colon to form the vegetative cells that initiate Clostridium difficile infections (CDI). During CDI, C. difficile induces a sporulation pathway that produces more spores; these spores are responsible for the persistence of C. difficile in patients and horizontal transmission between hospitalized patients. While important to the C. difficile lifecycle, the C. difficile spore proteome is poorly conserved when compared to members of the Bacillus genus. Further, recent studies have revealed significant differences between C. difficile and B. subtilis at the level of sporulation, germination and spore coat and exosporium morphogenesis. In this review, the regulation of the sporulation and germination pathways and the morphogenesis of the spore coat and exosporium will be discussed. PMID:24814671

  4. Fifth international fungus spore conference

    SciTech Connect

    Timberlake, W.E.

    1993-04-01

    This folio contains the proceedings of the Fifth International Fungal Spore Conference held August 17-21, 1991 at the Unicoi State Park at Helen, Georgia. The volume contains abstracts of each oral presentation as well as a collection of abstracts describing the poster sessions. Presentations were organized around the themes (1) Induction of Sporulation, (2) Nuclear Division, (3) Spore Formation, (4) Spore Release and Dispersal, and (4) Spore Germination.

  5. Anthrax Spores under a microscope

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Anthrax spores are inactive forms of Bacillus anthracis. They can survive for decades inside a spore's tough protective coating; they become active when inhaled by humans. A result of NASA- and industry-sponsored research to develop small greenhouses for space research is the unique AiroCide TiO2 system that kills anthrax spores and other pathogens.

  6. Transcriptomic profile of tobacco in response to Alternaria longipes and Alternaria alternata infections

    PubMed Central

    Duan, Shengchang; Ma, Xiao; Chen, Wei; Wan, Wenting; He, Yuqi; Ma, Xiaoqin; Ma, Yujin; Long, Ni; Tan, Yuntao; Wang, Yangzi; Hou, Yujie; Dong, Yang

    2016-01-01

    Tobacco brown spot caused by Alternaria fungal species is one of the most damaging diseases, and results in significant yield losses. However, little is known about the systematic response of tobacco to this fungal infection. To fill this knowledge gap, de novo assemblies of tobacco leaf transcriptomes were obtained in cultivars V2 and NC89 after the inoculation of either Alternaria longipes (AL) or Alternaria alternata (AA) at three different time points. We studied the gene expression profile of each cultivar-pathogen combination, and identified eight differentially expressed genes shared among all combinations. Gene ontology enrichment analysis of the differentially expressed genes revealed key components during the fungal infection, which included regulation of gene expression (GO:0010468), regulation of RNA metabolic process (GO:0051252), tetrapyrrole binding (GO:0046906), and external encapsulating structure (GO:0030312). Further analyses of the continuously upregulated/downregulated genes and the resistance genes demonstrated that the gene expression profile upon fungal infection was contingent on the specific cultivar and pathogen. In conclusion, this study provides a solid foundation for the investigation of plant-pathogen interaction, and is of great importance for disease prevention and molecular breeding. PMID:27157477

  7. Transcriptomic profile of tobacco in response to Alternaria longipes and Alternaria alternata infections.

    PubMed

    Duan, Shengchang; Ma, Xiao; Chen, Wei; Wan, Wenting; He, Yuqi; Ma, Xiaoqin; Ma, Yujin; Long, Ni; Tan, Yuntao; Wang, Yangzi; Hou, Yujie; Dong, Yang

    2016-01-01

    Tobacco brown spot caused by Alternaria fungal species is one of the most damaging diseases, and results in significant yield losses. However, little is known about the systematic response of tobacco to this fungal infection. To fill this knowledge gap, de novo assemblies of tobacco leaf transcriptomes were obtained in cultivars V2 and NC89 after the inoculation of either Alternaria longipes (AL) or Alternaria alternata (AA) at three different time points. We studied the gene expression profile of each cultivar-pathogen combination, and identified eight differentially expressed genes shared among all combinations. Gene ontology enrichment analysis of the differentially expressed genes revealed key components during the fungal infection, which included regulation of gene expression (GO:0010468), regulation of RNA metabolic process (GO:0051252), tetrapyrrole binding (GO:0046906), and external encapsulating structure (GO:0030312). Further analyses of the continuously upregulated/downregulated genes and the resistance genes demonstrated that the gene expression profile upon fungal infection was contingent on the specific cultivar and pathogen. In conclusion, this study provides a solid foundation for the investigation of plant-pathogen interaction, and is of great importance for disease prevention and molecular breeding. PMID:27157477

  8. Fungicidal activity of volatile oil from eucalyptus Citriodora Hook. against Alternaria triticina.

    PubMed

    Ramezani, Hesamedin

    2006-01-01

    Use of plant products for the management of phytopathogenic fungi is fast becoming an important component of Integrated Disease Management (I.D.M.) programme. The natural plant products are bio-degradable and thus eco-friendly, are catching the attention of the scientist worldwide. Such products from higher plants are relatively broad spectrum, bio-efficacious, economical and environmentally safe. Among these essential oils from higher plants because of their greater inhibitory action are being explored preferably worldwide. In this context, a study was undertaken to explore the effect of volatile oil from Eucalyptus citriodora against Alternaria triticina. The radial growth, dry weight and spore germination of pathogen were drastically reduced in response to the different concentrations of volatile oil. A complete inhibition of radial growth, dry weight and spore germination were observed at 1500, 1000 and 100 ppm, respectively. In contrast, similar complete inhibition of test pathogen was observed at very high concentration (6500, 6500 and 1000 ppm) of mancozeb--a commercially available synthetic fungicide. Based on these observations, it was therefore concluded that eucalypt volatile oil has potential to suppress the phytopathogenic fungi. PMID:17390838

  9. Spore: Spawning Evolutionary Misconceptions?

    NASA Astrophysics Data System (ADS)

    Bean, Thomas E.; Sinatra, Gale M.; Schrader, P. G.

    2010-10-01

    The use of computer simulations as educational tools may afford the means to develop understanding of evolution as a natural, emergent, and decentralized process. However, special consideration of developmental constraints on learning may be necessary when using these technologies. Specifically, the essentialist (biological forms possess an immutable essence), teleological (assignment of purpose to living things and/or parts of living things that may not be purposeful), and intentionality (assumption that events are caused by an intelligent agent) biases may be reinforced through the use of computer simulations, rather than addressed with instruction. We examine the video game Spore for its depiction of evolutionary content and its potential to reinforce these cognitive biases. In particular, we discuss three pedagogical strategies to mitigate weaknesses of Spore and other computer simulations: directly targeting misconceptions through refutational approaches, targeting specific principles of scientific inquiry, and directly addressing issues related to models as cognitive tools.

  10. Thermal Spore Exposure Vessels

    NASA Technical Reports Server (NTRS)

    Beaudet, Robert A.; Kempf, Michael; Kirschner, Larry

    2006-01-01

    Thermal spore exposure vessels (TSEVs) are laboratory containers designed for use in measuring rates of death or survival of microbial spores at elevated temperatures. A major consideration in the design of a TSEV is minimizing thermal mass in order to minimize heating and cooling times. This is necessary in order to minimize the number of microbes killed before and after exposure at the test temperature, so that the results of the test accurately reflect the effect of the test temperature. A typical prototype TSEV (see figure) includes a flat-bottomed stainless-steel cylinder 4 in. (10.16 cm) long, 0.5 in. (1.27 cm) in diameter, having a wall thickness of 0.010 plus or minus 0.002 in. (0.254 plus or minus 0.051 mm). Microbial spores are deposited in the bottom of the cylinder, then the top of the cylinder is closed with a sterile rubber stopper. Hypodermic needles are used to puncture the rubber stopper to evacuate the inside of the cylinder or to purge the inside of the cylinder with a gas. In a typical application, the inside of the cylinder is purged with dry nitrogen prior to a test. During a test, the lower portion of the cylinder is immersed in a silicone-oil bath that has been preheated to and maintained at the test temperature. Test temperatures up to 220 C have been used. Because the spores are in direct contact with the thin cylinder wall, they quickly become heated to the test temperature.

  11. The effects of meteorological factors on the occurrence of Ganoderma sp. spores in the air

    NASA Astrophysics Data System (ADS)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2011-03-01

    Ganoderma sp. is an airborne fungal spore type known to trigger respiratory allergy symptoms in sensitive patients. Aiming to reduce the risk for allergic individuals, we analysed fungal spore circulation in Szczecin, Poland, and its dependence on meteorological conditions. Statistical models for the airborne spore concentrations of Ganoderma sp.—one of the most abundant fungal taxa in the area—were developed. Aerobiological sampling was conducted over 2004-2008 using a volumetric Lanzoni trap. Simultaneously, the following meteorological parameters were recorded: daily level of precipitation, maximum and average wind speed, relative humidity and maximum, minimum, average and dew point temperatures. These data were used as the explaining variables. Due to the non-linearity and non-normality of the data set, the applied modelling techniques were artificial neural networks (ANN) and mutlivariate regression trees (MRT). The obtained classification and MRT models predicted threshold conditions above which Ganoderma sp. appeared in the air. It turned out that dew point temperature was the main factor influencing the presence or absence of Ganoderma sp. spores. Further analysis of spore seasons revealed that the airborne fungal spore concentration depended only slightly on meteorological factors.

  12. Spore collection and elimination apparatus and method

    DOEpatents

    Czajkowski, Carl; Warren, Barbara Panessa

    2007-04-03

    The present invention is for a spore collection apparatus and its method of use. The portable spore collection apparatus includes a suction source, a nebulizer, an ionization chamber and a filter canister. The suction source collects the spores from a surface. The spores are activated by heating whereby spore dormancy is broken. Moisture is then applied to the spores to begin germination. The spores are then exposed to alpha particles causing extinction.

  13. Clostridium difficile Spore-Macrophage Interactions: Spore Survival

    PubMed Central

    Paredes-Sabja, Daniel; Cofre-Araneda, Glenda; Brito-Silva, Christian; Pizarro-Guajardo, Marjorie; Sarker, Mahfuzur R.

    2012-01-01

    Background Clostridium difficile is the main cause of nosocomial infections including antibiotic associated diarrhea, pseudomembranous colitis and toxic megacolon. During the course of Clostridium difficile infections (CDI), C. difficile undergoes sporulation and releases spores to the colonic environment. The elevated relapse rates of CDI suggest that C. difficile spores has a mechanism(s) to efficiently persist in the host colonic environment. Methodology/Principal Findings In this work, we provide evidence that C. difficile spores are well suited to survive the host’s innate immune system. Electron microscopy results show that C. difficile spores are recognized by discrete patchy regions on the surface of macrophage Raw 264.7 cells, and phagocytosis was actin polymerization dependent. Fluorescence microscopy results show that >80% of Raw 264.7 cells had at least one C. difficile spore adhered, and that ∼60% of C. difficile spores were phagocytosed by Raw 264.7 cells. Strikingly, presence of complement decreased Raw 264.7 cells’ ability to phagocytose C. difficile spores. Due to the ability of C. difficile spores to remain dormant inside Raw 264.7 cells, they were able to survive up to 72 h of macrophage infection. Interestingly, transmission electron micrographs showed interactions between the surface proteins of C. difficile spores and the phagosome membrane of Raw 264.7 cells. In addition, infection of Raw 264.7 cells with C. difficile spores for 48 h produced significant Raw 264.7 cell death as demonstrated by trypan blue assay, and nuclei staining by ethidium homodimer-1. Conclusions/Significance These results demonstrate that despite efficient recognition and phagocytosis of C. difficile spores by Raw 264.7 cells, spores remain dormant and are able to survive and produce cytotoxic effects on Raw 264.7 cells. PMID:22952726

  14. Fungal spores and pollen in particulate matter collected during agricultural activities in the Po Valley (Italy).

    PubMed

    Telloli, Chiara; Chicca, Milvia; Leis, Marilena; Vaccaro, Carmela

    2016-08-01

    Airborne particulate matter (PM) containing fungal spores and pollen grains was sampled within a monitoring campaign of wheat threshing, plowing and sowing agricultural operations. Fungal spores and pollen grains were detected and identified on morphological basis. No studies were previously available about fungal spore and pollen content in agricultural PM in the Po Valley. Sampling was conducted in a Po Valley farmland in Mezzano (Ferrara, Italy). The organic particles collected were examined by scanning electron microscopy with energy dispersive X-ray spectrometer. Fungal spores and pollen grains were identified when possible at the level of species. The most frequent components of the organic particles sampled were spores of Aspergillus sp., which could represent a risk of developing allergies and aspergillosis for crop farmers. PMID:27521955

  15. Composition of tobaccos from countries with high and low incidences of lung cancer. I. Selenium, polonium-210, Alternaria, tar, and nicotine

    SciTech Connect

    Bogden, J.D.; Kemp, F.W.; Buse, M.; Thind, I.S.; Louria, D.B.; Forgacs, J.; Llanos, G.; Terrones, I.M.

    1981-01-01

    Tobaccos from countries with high and low incidences of lung cancer were analyzed. Tobacco concentrations of polonium-210 were similar in cigarettes from high- and low-incidence countries, as were levels of cigarette smoke tar and nicotine. Tobaccos from low-incidence countries had significantly lower Alternaria spore counts. Mean selenium concentrations of tobaccos from the high-incidence countries (0.16 +- 0.05 ..mu..g/g) were significantly lower than those of tobaccos from the low-incidence countries (0.49 +- 0.22 ..mu..g/g).

  16. Fungal microcolonies on indoor surfaces — an explanation for the base-level fungal spore counts in indoor air

    NASA Astrophysics Data System (ADS)

    Pasanen, A.-L.; Heinonen-Tanski, H.; Kalliokoski, P.; Jantunen, M. J.

    In the subarctic winter, fungal spores are found in indoor air even when outdoor spore levels are very low. The results of this study support an explanation that some indoor airborne fungal spores are derived from unnoticeable fungal microcolonies, which may develop on temporarily wet surfaces. Laboratory experiments on Penicillium verrucosum indicated that the fungus germinated on new wallpaper very quickly (about half an hour) under moist conditions. Hyphal growth and sporulation of the fungus on moist wallpaper occured within one day of incubation. In gravity-settling tape samples from occasionally wet surfaces in a suburban home, large spore aggregates, hyphal fragments with some spores and spores in the germination stage were found, indicating fungal growth. These experiments showed that fungal microcolonies can develop within a week on occasionally wet indoor surfaces.

  17. "Spore" and the Sociocultural Moment

    ERIC Educational Resources Information Center

    Meyer, W. Max

    2012-01-01

    Analyses of the game "Spore" have centered on the important issues of accuracy of evolution content and engendering interest in science. This paper suggests that examination of the degree of scaffolding necessary to use the game in pedagogy is a missing part of the discussion, and then questions the longevity of the "Spore" discussion relative to…

  18. Conidia of Alternaria in the atmosphere of the city of Cordoba, Spain in relation to meteorological parameters

    NASA Astrophysics Data System (ADS)

    Angulo-Romero, J.; Mediavilla-Molina, Ana; Domínguez-Vilches, Eugenio

    In this study, we have analyzed the presence of conidia belonging to different species of the genus Alternaria in the atmosphere of the city of Cordoba, using a Hirst sampler. The results show that spores of this genus are present all year, with a clear seasonal pattern which shows two peaks, one in spring and the other in fall. A total of 26,822 conidia/m3 have been sampled, which implies a daily mean of 74.3 conidia/m3. Statistical analyses comparing the data with meteorological parameters show a positive correlation with maximum, minimum and mean temperatures, and a negative correlation with rain. Nevertheless, meteorological parameters seem to affect the number of conidia differently according to the season of the year. Regression analyses carried out in order to obtain a predictive pattern show that the best fit is between the 7-day running mean of the number of conidia and a week's accumulated mean temperature.

  19. Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity.

    PubMed

    Kim, Wonyong; Park, Chung-Min; Park, Jeong-Jin; Akamatsu, Hajime O; Peever, Tobin L; Xian, Ming; Gang, David R; Vandemark, George; Chen, Weidong

    2015-04-01

    Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here, we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both Ascochyta rabiei and Alternaria solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound, prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of Ascochyta rabiei and Alternaria solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity. PMID:25372118

  20. Allergic bronchopulmonary mycosis due to Alternaria: Case report and review.

    PubMed

    Singh, Bhagteshwar; Denning, David W

    2012-01-01

    While allergic bronchopulmonary aspergillosis and mycosis are well recognised, no cases have been described related to Alternaria spp. Alternaria is a common sensitising fungus in asthmatics and related to thunderstorm asthma. We report a case of an asthmatic who presented with worsening asthma control, mild eosinophilia on high dose inhaled corticosteroids (800 μg/day), a total IgE of 3800 KIU/L, an Alternaria-specific IgE of 21.3 KUa/L and positive skin prick test, negative specific IgE and skin prick test to Aspergillus fumigatus, Penicillium spp., Cladosporium spp., Trichophyton spp. and a normal CT scan of the thorax. He responded well to a short course of oral prednisolone and then oral itraconazole, given over 17 months but relapsed 1 month after stopping it. PMID:24371728

  1. 40 CFR 180.1256 - Alternaria destruens strain 059; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Alternaria destruens strain 059... RESIDUES IN FOOD Exemptions From Tolerances § 180.1256 Alternaria destruens strain 059; exemption from the... the microbial pesticide Alternaria destruens Strain 059 when used in or on all raw...

  2. Cutaneous Alternariosis Caused by Alternaria infectoria: Three Cases in Kidney Transplant Patients.

    PubMed

    Lopes, Leonor; Borges-Costa, João; Soares-Almeida, Luís; Filipe, Paulo; Neves, Fernanda; Santana, Alice; Guerra, José; Kutzner, Heinz

    2013-01-01

    The genus Alternaria has more than 80 species. Alternaria alternata and Alternaria infectoria are the most frequent species associated with infections in humans. Their clinical importance lies in the growing number of cases reported in immunocompromised patients. Herein, we report three cases of kidney-transplanted patients with different clinical presentations of cutaneous alternariosis and we discuss the treatment options. PMID:27429134

  3. Cutaneous Alternariosis Caused by Alternaria infectoria: Three Cases in Kidney Transplant Patients

    PubMed Central

    Lopes, Leonor; Borges-Costa, João; Soares-Almeida, Luís; Filipe, Paulo; Neves, Fernanda; Santana, Alice; Guerra, José; Kutzner, Heinz

    2013-01-01

    The genus Alternaria has more than 80 species. Alternaria alternata and Alternaria infectoria are the most frequent species associated with infections in humans. Their clinical importance lies in the growing number of cases reported in immunocompromised patients. Herein, we report three cases of kidney-transplanted patients with different clinical presentations of cutaneous alternariosis and we discuss the treatment options. PMID:27429134

  4. Comparative particle recoveries by the retracting rotorod, rotoslide and Burkard spore trap sampling in a compact array

    NASA Astrophysics Data System (ADS)

    Solomon, W. R.; Burge, H. A.; Boise, J. R.; Becker, M.

    1980-06-01

    An array comprising 4 intermittent (retracting) rotorods, 3 (“swingshield”) rotoslides and one Burkard (Hirst) automatic volumetric spore trap was operated on an urban rooftop during 70 periods of 9, 15 or 24 hours in late summer. Standard sampling procedures were utilized and recoveries of pollens as well as spores of Alternaria, Epicoccum, Pithomyces and Ganoderma species compared. Differences between paired counts from each sampler type showed variances increasing with levels of particle prevalence (and deposition). In addition, minimal, non-random, side-to-side and intersampler differences were noted for both impactor types. Exclusion of particles between operating intervals by rotoslides and rotorods was virtually complete. Spore trap recoveries for all particle categories, per m3, exceeded those by both impactors. The greatest (7-fold) difference was noted for the smallest type examined ( Ganoderma). For ragweed pollen, an overall spore trap/impactor ratio approached 1.5. Rain effects were difficult to discern but seemed to influence rotoslides least. Overall differences between impactors were quite small but generally favored the rotoslide in this comparison. Our data confirm the relative advantages of suction traps for small particles. Both impactors and spore traps are suited to pollen and large spore collection, and, with some qualification, data from both may be compared.

  5. Characteristics and determinants of ambient fungal spores in Hualien, Taiwan

    NASA Astrophysics Data System (ADS)

    Ho, Hsiao-Man; Rao, Carol Y.; Hsu, Hsiao-Hsien; Chiu, Yueh-Hsiu; Liu, Chi-Ming; Chao, H. Jasmine

    Characteristics and determinants of ambient aeroallergens are of much concern in recent years because of the apparent health impacts of allergens. Yet relatively little is known about the complex behaviors of ambient aeroallergens. To address this issue, we monitored ambient fungal spores in Hualien, Taiwan from 1993-1996 to examine the compositions and temporal variations of fungi, and to evaluate possible determinants. We used a Burkard seven-day volumetric spore trap to collect daily fungal spores. Air pollutants, meteorological factors, and Asian dust events were included in the statistical analyses to predict fungal levels. We found that the most dominant fungal categories were ascospores, followed by Cladosporium and Aspergillus/Penicillium. The majority of the fungal categories had significant diurnal and seasonal variations. Total fungi, Cladosporium, Ganoderma, Arthrinium/Papularia, Cercospora, Periconia, Alternaria, Botrytis, and PM 10 had significantly higher concentrations ( p<0.05) during the period affected by Asian dust events. In multiple regression models, we found that temperature was consistently and positively associated with fungal concentrations. Other factors correlated with fungal concentrations included ozone, particulate matters with an aerodynamic diameter less than 10 μm (PM 10), relative humidity, rainfall, atmospheric pressure, total hydrocarbons, carbon monoxide, nitrogen dioxide, and sulfur dioxide. Most of the fungal categories had higher levels in 1994 than in 1995-96, probably due to urbanization of the study area. In this study, we demonstrated complicated interrelationships between fungi and air pollution/meteorological factors. In addition, long-range transport of air pollutants contributed significantly to local aeroallergen levels. Future studies should examine the health impacts of aeroallergens, as well as the synergistic/antagonistic effects of weather, and local and global-scale air pollutions.

  6. Ultrastructure and properties of Paecilomyces lilacinus spores.

    PubMed

    Holland, R J; Gunasekera, T S; Williams, K L; Nevalainen, K M H

    2002-10-01

    Strains of the filamentous soil fungus Paecilomyces lilacinus are currently being developed for use as biological control agents against root-knot, cyst, and other plant-parasitic nematodes. The inoculum applied in the field consists mainly of spores. This study was undertaken to examine the size, ultrastructure, and rodlet layers of P. lilacinus spores and the effect of the culture method on structural and functional spore properties. A rodlet layer was identified on aerial spores only. Other differences noted between aerial spores and those produced in submerged culture included the size and appearance of spores and thickness of spore coat layers when examined with transmission electron microscopy. The two spore types differed in UV tolerance, with aerial spores being less sensitive to environmentally relevant UV radiation. Also, viability after drying and storage was better with the aerial spores. Both spore types exhibited similar nematophagous ability. PMID:12489777

  7. Hydrazine vapor inactivates Bacillus spores

    NASA Astrophysics Data System (ADS)

    Schubert, Wayne W.; Engler, Diane L.; Beaudet, Robert A.

    2016-05-01

    NASA policy restricts the total number of bacterial spores that can remain on a spacecraft traveling to any planetary body which might harbor life or have evidence of past life. Hydrazine, N2H4, is commonly used as a propellant on spacecraft. Hydrazine as a liquid is known to inactivate bacterial spores. We have now verified that hydrazine vapor also inactivates bacterial spores. After Bacillus atrophaeus ATCC 9372 spores deposited on stainless steel coupons were exposed to saturated hydrazine vapor in closed containers, the spores were recovered from the coupons, serially diluted, pour plated and the surviving bacterial colonies were counted. The exposure times required to reduce the spore population by a factor of ten, known as the D-value, were 4.70 ± 0.50 h at 25 °C and 2.85 ± 0.13 h at 35 °C. These inactivation rates are short enough to ensure that the bioburden of the surfaces and volumes would be negligible after prolonged exposure to hydrazine vapor. Thus, all the propellant tubing and internal tank surfaces exposed to hydrazine vapor do not contribute to the total spore count.

  8. PERMEABILITY OF BACTERIAL SPORES I.

    PubMed Central

    Black, S. H.; Gerhardt, Philipp

    1961-01-01

    Black, S. H. (The University of Michigan, Ann Arbor) and Philipp Gerhardt. Permeability of bacterial spores. I. Characterization of glucose uptake. J. Bacteriol. 82:743–749. 1961.—The total uptake of glucose by masses of clean, dormant spores was measured to assess their permeability. After correction for intercellular space, packed spores of Bacillus cereus strain terminalis were found in 87 determinations to be permeated by glucose to 40% of their weight. The glucose uptake was relatively independent of environmental variables, and thus was concluded to occur principally through a process of passive diffusion. PMID:13869665

  9. Microbial profile modification with spores

    SciTech Connect

    Bae, J.H.; Chambers, K.T.; Lee, H.O.

    1996-08-01

    To overcome the shortcomings of conventional, near-wellbore profile modification methods, a microbial profile modification (MPM) method with spores was investigated. A halotolerant, spore-forming mesophile was isolated and characterized. These biopolymer-producing spores propagate easily in Berea cores with permeabilities more than about 500 md. With a specifically formulated nutrient package, they are readily germinated and produce biofilm, which reduces the permeability of the rock. The depth of penetration and the degree of permeability reduction can be controlled by varying injection schemes.

  10. Spore and the sociocultural moment

    NASA Astrophysics Data System (ADS)

    Meyer, W. Max

    2012-12-01

    Analyses of the game Spore have centered on the important issues of accuracy of evolution content and engendering interest in science. This paper suggests that examination of the degree of scaffolding necessary to use the game in pedagogy is a missing part of the discussion, and then questions the longevity of the Spore discussion relative to the general dissatisfaction with the science presented in the game. The paper proposes that analysis of Spore and other technological tools in science education may be embedded in an historical moment which directs the discussion towards satisfying sociocultural and organizational needs and away from pedagogical ones.

  11. Spore Coat Architecture of Clostridium novyi-NT spores

    SciTech Connect

    Plomp, M; McCafferey, J; Cheong, I; Huang, X; Bettegowda, C; Kinzler, K; Zhou, S; Vogelstein, B; Malkin, A

    2007-05-07

    Spores of the anaerobic bacterium Clostridium novyi-NT are able to germinate in and destroy hypoxic regions of tumors in experimental animals. Future progress in this area will benefit from a better understanding of the germination and outgrowth processes that are essential for the tumorilytic properties of these spores. Towards this end, we have used both transmission electron microscopy and atomic force microscopy to determine the structure of dormant as well as germinating spores. We found that the spores are surrounded by an amorphous layer intertwined with honeycomb parasporal layers. Moreover, the spore coat layers had apparently self-assembled and this assembly was likely to be governed by crystal growth principles. During germination and outgrowth, the honeycomb layers as well as the underlying spore coat and undercoat layers sequentially dissolved until the vegetative cell was released. In addition to their implications for understanding the biology of C. novyi-NT, these studies document the presence of proteinaceous growth spirals in a biological organism.

  12. Genetic variability in the pistachio late blight fungus, Alternaria alternata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic variation in the pistachio late blight fungus, Alternaria alternata, was investigated by restriction fragment length polymorphism (RFLP) in the rDNA region. Southern hybridization of EcoRI, HindIII, and Xbal digested fungal DNA with a RNA probe derived from Alt1, an rDNA clone isolated from ...

  13. CHARACTERIZATION OF SPORULATION OF ALTERNARIA ALTERNATA F. SP. SPHENOCLEAE.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted on agar media to characterize the factors for the optimization of sporulation of Alternaria alternata f. sp. sphenocleae, a fungal pathogen being evaluated as a biological control agent for Sphenoclea zeylanica (gooseweed). A. alternata f. sp. sphenocleae conidiation was affec...

  14. Draft Genome Sequence of Alternaria alternata ATCC 34957.

    PubMed

    Nguyen, Hai D T; Lewis, Christopher T; Lévesque, C André; Gräfenhan, Tom

    2016-01-01

    We report the draft genome sequence of Alternaria alternata ATCC 34957. This strain was previously reported to produce alternariol and alternariol monomethyl ether on weathered grain sorghum. The genome was sequenced with PacBio technology and assembled into 27 scaffolds with a total genome size of 33.5 Mb. PMID:26769939

  15. TWO NEW SPECIES OF ALTERNARIA FROM PEAR FRUIT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During studies conducted over the past 15 years of various diseases of deciduous tree fruit from around the world, hundreds of Alternaria isolates have been made and characterized using morphological and molecular methods. Two such fungi are newly described here as A. calycipyricola sp. nov. from th...

  16. NASA Facts: SporeSat

    NASA Technical Reports Server (NTRS)

    Martinez, Andres; Cappuccio, Gelsomina; Tomko, David

    2013-01-01

    SporeSat is an autonomous, free-flying three-unit (3U) spacecraft that will be used to conduct scientific experiments to gain a deeper knowledge of the mechanisms of plant cell gravity sensing. SporeSat is being developed through a partnership between NASAs Ames Research Center and the Department of Agricultural and Biological Engineering at Purdue University. Amani Salim and Jenna L. Rickus are the Purdue University Principal Investigators. The SporeSat mission will be flown using a 3U nanosatellite weighing approximately 12 pounds and measuring 14 inches long by 4 inches wide by 4 inches tall. SporeSat will utilize flight-proven spacecraft technologies demonstrated on prior Ames nanosatellite missions such as PharmaSat and OrganismOrganic Exposure to Orbital Stresses (OOREOS) as well as upgrades that increase the hardware integration capabilities with SporeSat science instrumentation. In addition, the SporeSat science payload will serve as a technology platform to evaluate new microsensor technologies for enabling future fundamental biology missions.

  17. Identifying and Inactivating Bacterial Spores

    NASA Technical Reports Server (NTRS)

    Newcombe, David; Dekas, Anne; Venkateswaran, Kasthuri

    2009-01-01

    Problems associated with, and new strategies for, inactivating resistant organisms like Bacillus canaveralius (found at Kennedy Space Center during a survey of three NASA cleanrooms) have been defined. Identifying the particular component of the spore that allows its heightened resistance can guide the development of sterilization procedures that are targeted to the specific molecules responsible for resistance, while avoiding using unduly harsh methods that jeopardize equipment. The key element of spore resistance is a multilayered protein shell that encases the spore called the spore coat. The coat of the best-studied spore-forming microbe, B. subtilis, consists of at least 45 proteins, most of which are poorly characterized. Several protective roles for the coat are well characterized including resistance to desiccation, large toxic molecules, ortho-phthalaldehyde, and ultraviolet (UV) radiation. One important long-term specific goal is an improved sterilization procedure that will enable NASA to meet planetary protection requirements without a terminal heat sterilization step. This would support the implementation of planetary protection policies for life-detection missions. Typically, hospitals and government agencies use biological indicators to ensure the quality control of sterilization processes. The spores of B. canaveralius that are more resistant to osmotic stress would serve as a better biological indicator for potential survival than those in use currently.

  18. Effect of relative humidity on the aerodynamic diameter and respiratory deposition of fungal spores

    NASA Astrophysics Data System (ADS)

    Reponen, Tiina; Willeke, Klaus; Ulevicius, Vidmantas; Reponen, Auvo; Grinshpun, Sergey A.

    Exposure to airborne fungal spores may cause respiratory symptoms. The hygroscopicity of airborne spores may significantly affect their aerodynamic diameter, and thus change their deposition pattern in the human respiratory tract. We have investigated the change in aerodynamic diameter of five different fungal species as a function of relative humidity. Liquid and dry dispersion methods were explored for the aerosolization of the fungal spores. A new system that produces non-aggregated spore aerosol directly from a moldy surface was designed and found suitable for this study. The spores were aerosolized from a mold growth on agar by ducting dry air over the surface, and spore chains in the flow were broken up by passing the entire flow through a critical orifice. Size-spectrometric measurements with an Aerodynamic Particle Sizer showed that the aerodynamic diameter of the tested fungal spores does not change significantly when the relative humidity increases from 30% to 90%. A more distinct spore size increase was found at a relative humidity of ˜ 100%. The highest change of the aerodynamic diameter was found with Cladosporium cladosporioides: it increased from 1.8 μm to 2.3 μm when the relative humidity increased from 30% to ˜ 100%. The size increase corresponds to an approximate doubling of the particle volume. In order to estimate the effect of hygroscopic growth on the respiratory deposition of spores, the mean depositions in the human respiratory tract were calculated for fungal spores with various size changes due to hygroscopic growth. A recently developed model of the International Commission of Radiological Protection was used for the respiratory deposition calculations. We found that the 27% increase in Cladosporium size results in a 20-30% increase in the respiratory deposition of these spores. We conclude that most fungal spores are only slightly hygroscopic and the hygroscopic increase does not significantly affect their respiratory deposition. Our

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

    PubMed

    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

  20. 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

  1. Intervention study of airborne fungal spora in homes with portable HEPA filtration units.

    PubMed

    Cheong, C D; Neumeister-Kemp, H G; Dingle, P W; Hardy, G St J

    2004-11-01

    The concentrations and composition of airborne fungal spores in homes fitted with portable HEPA filtration units were examined to provide information to evaluate the importance of varying levels of fungal spores in residential environments in Perth, Australia. A novel method for simulating activity/impaction on carpeted environments was also investigated. Reductions in fungal (35%) and particulate (38%) levels were achieved in the air filter homes. Penicillium, Cladosporium and yeasts were the most common and widespread fungi recovered indoors and outdoors. Fungal range decreased over the study period but this could be due to an overall reduced dissemination of spores (less spores in the air). PMID:15536499

  2. Measuring Total and Germinable Spore Populations

    NASA Technical Reports Server (NTRS)

    Noell, A.C.; Yung, P.T.; Yang, W.; Lee, C.; Ponce, A.

    2011-01-01

    It has been shown that bacterial endospores can be enumerated using a microscopy based assay that images the luminescent halos from terbium ions bound to dipicolinic acid, a spore specific chemical marker released upon spore germination. Further development of the instrument has simplified it towards automation while at the same time improving image quality. Enumeration of total spore populations has also been developed allowing measurement of the percentage of viable spores in any population by comparing the germinable/culturable spores to the total. Percentage viability will allow a more quantitative comparison of the ability of spores to survive across a wide range of extreme environments.

  3. Measuring Total and Germinable Spore Populations

    NASA Astrophysics Data System (ADS)

    Noell, A. C.; Yung, P. T.; Yang, W.; Ponce, A.; Lee, C.

    2011-10-01

    It has been shown that bacterial endospores can be enumerated using a microscopy based assay that images the luminescent halos from terbium ions bound to dipicolinic acid, a spore specific chemical marker released upon spore germination. Further development of the instrument has simplified it towards automation while at the same time improving image quality. Enumeration of total spore populations has also been developed allowing measurement of the percentage of viable spores in any population by comparing the germinable/culturable spores to the total. Percentage viability will allow a more quantitative comparison of the ability of spores to survive across a wide range of extreme environments.

  4. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  5. Airborne laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven E.

    2002-06-01

    The US Air Force Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success.

  6. Fungal spores: hazardous to health?

    PubMed Central

    Sorenson, W G

    1999-01-01

    Fungi have long been known to affect human well being in various ways, including disease of essential crop plants, decay of stored foods with possible concomitant production of mycotoxins, superficial and systemic infection of human tissues, and disease associated with immune stimulation such as hypersensitivity pneumonitis and toxic pneumonitis. The spores of a large number of important fungi are less than 5 microm aerodynamic diameter, and therefore are able to enter the lungs. They also may contain significant amounts of mycotoxins. Diseases associated with inhalation of fungal spores include toxic pneumonitis, hypersensitivity pneumonitis, tremors, chronic fatigue syndrome, kidney failure, and cancer. PMID:10423389

  7. Fungi in a changing world: growth rates will be elevated, but spore production may decrease in future climates

    NASA Astrophysics Data System (ADS)

    Damialis, Athanasios; Mohammad, Aqilah B.; Halley, John M.; Gange, Alan C.

    2015-09-01

    Very little is known about the impact of climate change on fungi and especially on spore production. Fungal spores can be allergenic, thus being important for human health. The aim of this study was to investigate how climate change influences the responsive ability of fungi by simulating differing environmental regimes. Fungal species with high spore allergenic potential and atmospheric abundance were grown and experimentally examined under a variety of temperatures and different nutrient availability. Each represented the average decadal air temperature of the 1980s, 1990s and 2000s in the UK, along with an Intergovernmental Panel on Climate Change (IPCC) climate change scenario for 2100. All tests were run on six fungal species: Alternaria alternata, Aspergillus niger, Botrytis cinerea, Cladosporium cladosporioides, Cladosporium oxysporum and Epicoccum purpurascens. Mycelium growth rate and spore production were examined on each single species and competitive capacity among species combinations in pairs. All fungal species grew faster at higher temperatures, and this was more pronounced for the temperature projection in 2100. Most species grew faster when there was lower nutrient availability. Exceptions were the species with the highest growth rate ( E. purpurascens) and with the highest competition capacity ( A. alternata). Most species (except for E. purpurascens) produced more spores in the richer nutrient medium but fewer as temperature increased. C. cladosporioides was an exception, exponentially increasing its spore production in the temperature of the 2100 scenario. Regarding competitive capacity, no species displayed any significant alterations within the environmental range checked. It is suggested that in future climates, fungi will display dramatic growth responses, with faster mycelium growth and lower spore production, with questions risen on relevant allergen potential.

  8. Spore sensitivity to sunlight and freezing can restrict dispersal in wood-decay fungi.

    PubMed

    Norros, Veera; Karhu, Elina; Nordén, Jenni; Vähätalo, Anssi V; Ovaskainen, Otso

    2015-08-01

    Assessment of the costs and benefits of dispersal is central to understanding species' life-history strategies as well as explaining and predicting spatial population dynamics in the changing world. While mortality during active movement has received much attention, few have studied the costs of passive movement such as the airborne transport of fungal spores. Here, we examine the potential of extreme environmental conditions to cause dispersal mortality in wood-decay fungi. These fungi play a key role as decomposers and habitat creators in forest ecosystems and the populations of many species have declined due to habitat loss and fragmentation. We measured the effect of simulated solar radiation (including ultraviolet A and B) and freezing at -25°C on the spore germinability of 17 species. Both treatments but especially sunlight markedly reduced spore germinability in most species, and species with thin-walled spores were particularly light sensitive. Extrapolating the species' laboratory responses to natural irradiance conditions, we predict that sunlight is a relevant source of dispersal mortality at least at larger spatial scales. In addition, we found a positive effect of spore size on spore germinability, suggesting a trade-off between dispersal distance and establishment. We conclude that freezing and particularly sunlight can be important sources of dispersal mortality in wood-decay fungi which can make it difficult for some species to colonize isolated habitat patches and habitat edges. PMID:26380666

  9. Spore sensitivity to sunlight and freezing can restrict dispersal in wood-decay fungi

    PubMed Central

    Norros, Veera; Karhu, Elina; Nordén, Jenni; Vähätalo, Anssi V; Ovaskainen, Otso

    2015-01-01

    Assessment of the costs and benefits of dispersal is central to understanding species' life-history strategies as well as explaining and predicting spatial population dynamics in the changing world. While mortality during active movement has received much attention, few have studied the costs of passive movement such as the airborne transport of fungal spores. Here, we examine the potential of extreme environmental conditions to cause dispersal mortality in wood-decay fungi. These fungi play a key role as decomposers and habitat creators in forest ecosystems and the populations of many species have declined due to habitat loss and fragmentation. We measured the effect of simulated solar radiation (including ultraviolet A and B) and freezing at −25°C on the spore germinability of 17 species. Both treatments but especially sunlight markedly reduced spore germinability in most species, and species with thin-walled spores were particularly light sensitive. Extrapolating the species' laboratory responses to natural irradiance conditions, we predict that sunlight is a relevant source of dispersal mortality at least at larger spatial scales. In addition, we found a positive effect of spore size on spore germinability, suggesting a trade-off between dispersal distance and establishment. We conclude that freezing and particularly sunlight can be important sources of dispersal mortality in wood-decay fungi which can make it difficult for some species to colonize isolated habitat patches and habitat edges. PMID:26380666

  10. Identification and characterization of microsatellite from Alternaria brassicicola to assess cross-species transferability and utility as a diagnostic marker.

    PubMed

    Singh, Ruchi; Kumar, Sudheer; Kashyap, Prem Lal; Srivastava, Alok Kumar; Mishra, Sanjay; Sharma, Arun Kumar

    2014-11-01

    Alternaria blight caused by Alternaria brassicicola (Schwein.) Wiltshire and A. brassicae (Berk.) Sacc., is one of the most important disease of rapeseed-mustard, characterized by the formation of spots on leaves, stem, and siliquae with premature defoliation and stunting of growth. These two species are very difficult to differentiate based on disease symptoms or spore morphology. Therefore, the aim of present investigation was to identify and characterize transferable microsatellite loci from A. brassicicola to A. brassicae for the development of diagnostic marker. A total of 8,457 microsatellites were identified from transcript sequences of A. brassicicola. The average density of microsatellites was one microsatellite per 1.94 kb of transcript sequence screened. The most frequent repeat was tri-nucleotide (74.03 %), whereas penta-nucleotide (1.14 %) was least frequent. Among amino acids, arginine (13.11 %) showed maximum abundance followed by lysine (10.11 %). A total of 32 alleles were obtained across the 31 microsatellite loci for the ten isolates of A. brassicicola. In cross-species amplifications, 5 of the 31 markers amplified the corresponding microsatellite regions in twenty isolates of A. brassicae and showed monomorphic banding pattern. Microsatellite locus ABS28 was highly specific for A. brassicicola, as no amplification was observed from twenty-nine other closely related taxa. Primer set, ABS28F/ABS28R, amplified a specific amplicon of 380 bp from all A. brassicicola isolates. Standard curves were generated for A. brassicicola isolate using SYBR Green I fluorescent dye for detection of amplification in real-time PCR assay. The lowest detection limit of assay was 0.01 ng. Thus, the primer set can be used as diagnostic marker to discriminate and diagnose A. brassicicola from synchronously occurring fungus, A. brassicae associated with rapeseed and mustard. PMID:25048820

  11. Temporal dynamics of airborne fungi in Havana (Cuba) during dry and rainy seasons: influence of meteorological parameters

    NASA Astrophysics Data System (ADS)

    Almaguer, Michel; Aira, María-Jesús; Rodríguez-Rajo, F. Javier; Rojas, Teresa I.

    2014-09-01

    The aim of this paper was to determine for first time the influence of the main meteorological parameters on the atmospheric fungal spore concentration in Havana (Cuba). This city is characterized by a subtropical climate with two different marked annual rainfall seasons during the year: a "dry season" and a "rainy season". A nonviable volumetric methodology (Lanzoni VPPS-2000 sampler) was used to sample airborne spores. The total number of spores counted during the 2 years of study was 293,594, belonging to 30 different genera and five spore types. Relative humidity was the meteorological parameter most influencing the atmospheric concentration of the spores, mainly during the rainy season of the year. Winds coming from the SW direction also increased the spore concentration in the air. In terms of spore intradiurnal variation we found three different patterns: morning maximum values for Cladosporium, night peaks for Coprinus and Leptosphaeria, and uniform behavior throughout the whole day for Aspergillus/ Penicillium."

  12. Fungal spores as potential ice nuclei in fog/cloud water and snow

    NASA Astrophysics Data System (ADS)

    Bauer, Heidi; Goncalves, Fabio L. T.; Schueller, Elisabeth; Puxbaum, Hans

    2010-05-01

    . Atmos. Res. 64, 109-119. Bauer, H., Schueller, E., Weinke, G. Berger, A., Hitzenberger, R., Marr, I.L., Puxbaum, H. (2008). Significant contributions of fungal spores to the organic carbon and to the aerosol mass balance of the urban atmospheric aerosol. Atmos. Environ. 42, 5542-5549. Bowers, R.M., Lauber, C.L., Wiedinmyer, C., Hamady, M., Hallar, A.G., Fall, R., Knight, R., Fierer, N. (2009). Characterization of airborne microbial communities at a high-elevation site and their potential to act as atmospheric ice nuclei. Appl. Environ. Microbiol: 75, 5121-5130.

  13. Modulation of Alternaria infectoria Cell Wall Chitin and Glucan Synthesis by Cell Wall Synthase Inhibitors

    PubMed Central

    Fernandes, Chantal; Anjos, Jorge; Walker, Louise A.; Silva, Branca M. A.; Cortes, Luísa; Mota, Marta; Munro, Carol A.; Gow, Neil A. R.

    2014-01-01

    The present work reports the effects of caspofungin, a β-1,3-glucan synthase inhibitor, and nikkomycin Z, an inhibitor of chitin synthases, on two strains of Alternaria infectoria, a melanized fungus involved in opportunistic human infections and respiratory allergies. One of the strains tested, IMF006, bore phenotypic traits that conferred advantages in resisting antifungal treatment. First, the resting cell wall chitin content was higher and in response to caspofungin, the chitin level remained constant. In the other strain, IMF001, the chitin content increased upon caspofungin treatment to values similar to basal IMF006 levels. Moreover, upon caspofungin treatment, the FKS1 gene was upregulated in IMF006 and downregulated in IMF001. In addition, the resting β-glucan content was also different in both strains, with higher levels in IMF001 than in IMF006. However, this did not provide any advantage with respect to echinocandin resistance. We identified eight different chitin synthase genes and studied relative gene expression when the fungus was exposed to the antifungals under study. In both strains, exposure to caspofungin and nikkomycin Z led to modulation of the expression of class V and VII chitin synthase genes, suggesting its importance in the robustness of A. infectoria. The pattern of A. infectoria phagocytosis and activation of murine macrophages by spores was not affected by caspofungin. Monotherapy with nikkomycin Z and caspofungin provided only fungistatic inhibition, while a combination of both led to fungal cell lysis, revealing a strong synergistic action between the chitin synthase inhibitor and the β-glucan synthase inhibitor against this fungus. PMID:24614372

  14. Optimizing Bacillus subtilis spore isolation and quantifying spore harvest purity.

    PubMed

    Harrold, Zoë R; Hertel, Mikaela R; Gorman-Lewis, Drew

    2011-12-01

    Investigating the biochemistry, resilience and environmental interactions of bacterial endospores often requires a pure endospore biomass free of vegetative cells. Numerous endospore isolation methods, however, neglect to quantify the purity of the final endospore biomass. To ensure low vegetative cell contamination we developed a quality control technique that enables rapid quantification of endospore harvest purity. This method quantifies spore purity using bright-field and fluorescence microscopy imaging in conjunction with automated cell counting software. We applied this method to Bacillus subtilis endospore harvests isolated using a two-phase separation method that utilizes mild chemicals. The average spore purity of twenty-two harvests was 88±11% (error is 1σ) with a median value of 93%. A spearman coefficient of 0.97 correlating automated and manual bacterial counts confirms the accuracy of software generated data. PMID:21989299

  15. Isolating and Purifying Clostridium difficile Spores.

    PubMed

    Edwards, Adrianne N; McBride, Shonna M

    2016-01-01

    The ability for the obligate anaerobe, Clostridium difficile to form a metabolically dormant spore is critical for the survival of this organism outside of the host. This spore form is resistant to a myriad of environmental stresses, including heat, desiccation, and exposure to disinfectants and antimicrobials. These intrinsic properties of spores allow C. difficile to survive long-term in an oxygenated environment, to be easily transmitted from host-to-host, and to persist within the host following antibiotic treatment. Because of the importance of the spore form to the C. difficile life cycle and treatment and prevention of C. difficile infection (CDI), the isolation and purification of spores are necessary to study the mechanisms of sporulation and germination, investigate spore properties and resistances, and for use in animal models of CDI. Here we provide basic protocols, in vitro growth conditions, and additional considerations for purifying C. difficile spores for a variety of downstream applications. PMID:27507337

  16. Theory of femtosecond coherent anti-Stokes Raman backscattering enhanced by quantum coherence for standoff detection of bacterial spores

    NASA Astrophysics Data System (ADS)

    Ooi, C. H. Raymond; Beadie, Guy; Kattawar, George W.; Reintjes, John F.; Rostovtsev, Yuri; Zubairy, M. Suhail; Scully, Marlan O.

    2005-08-01

    Backscattered signal of coherent anti-Stokes Raman spectroscopy can be an extremely useful tool for remote identification of airborne particles, provided the signal is sufficiently large. We formulate a semiclassical theory of nonlinear scattering to estimate the number of detectable photons from a bacterial spore at a distance. For the first time, the theory incorporates enhanced quantum coherence via femtosecond pulses and a nonlinear process into the classical scattering problem. Our result shows a large backscattered signal in the far field, using typical parameters of an anthrax spore with maximally prepared vibrational coherence. Using train pulses of 1 kHz of repetition rate each with energy of 10 mJ, we estimate that about 107 photons can be detected by a 1 m diameter detector placed 1 km away from the spore in the backward scattering direction. The result shows the feasibility of developing a real time remote detection of hazardous microparticles in the atmosphere, particularly biopathogenic spores.

  17. Theory of femtosecond coherent anti-Stokes Raman backscattering enhanced by quantum coherence for standoff detection of bacterial spores

    SciTech Connect

    Ooi, C.H. Raymond; Rostovtsev, Yuri; Scully, Marlan O.; Beadie, Guy; Reintjes, John F.; Kattawar, George W.; Zubairy, M. Suhail

    2005-08-15

    Backscattered signal of coherent anti-Stokes Raman spectroscopy can be an extremely useful tool for remote identification of airborne particles, provided the signal is sufficiently large. We formulate a semiclassical theory of nonlinear scattering to estimate the number of detectable photons from a bacterial spore at a distance. For the first time, the theory incorporates enhanced quantum coherence via femtosecond pulses and a nonlinear process into the classical scattering problem. Our result shows a large backscattered signal in the far field, using typical parameters of an anthrax spore with maximally prepared vibrational coherence. Using train pulses of 1 kHz of repetition rate each with energy of 10 mJ, we estimate that about 10{sup 7} photons can be detected by a 1 m diameter detector placed 1 km away from the spore in the backward scattering direction. The result shows the feasibility of developing a real time remote detection of hazardous microparticles in the atmosphere, particularly biopathogenic spores.

  18. Alternaria roseogrisea, a new species from achenes of Helianthus annuus (sunflower)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria roseogrisea was isolated from the achenes of Helianthus annuus L. during studies conducted in 1983-85 to document the diversity of fungi occurring in sunflower seeds and the possible role these fungi play in degradation of oilseed quality. A. roseogrisea was reported as "Alternaria sp. 2...

  19. Phylogenetic, morphological and pathogenic characterization of Alternaria species associated with fruit rots of blueberry in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruits. Alternaria spp. isolates were collected from decayed fruits of blueberry in the Central Valley of California during 2012 and 2013. The aims of this study wer...

  20. Leaf Petiole and Stem Blight Disease of Sweet Potato Caused by Alternaria Bataticola in Uganda

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria leaf petiole and stem blight is an important disease of sweet potato (Ipomoea batatus (L.) Lam.) in tropical and sub-tropical regions. In surveys conducted in Uganda from 2001 to 2003, disease incidence ranged from 0-49%. Symptoms of Alternaria leaf and stem blight disease consisted of sm...

  1. Modelling and visualizing morphology in the fungus Alternaria.

    PubMed

    Taralova, Ekaterina H; Schlecht, Joseph; Barnard, Kobus; Pryor, Barry M

    2011-11-01

    Alternaria is one of the most cosmopolitan fungal genera encountered and impacts humans and human activities in areas of material degradation, phytopathology, food toxicology, and respiratory disease. Contemporary methods of taxon identification rely on assessments of morphology related to sporulation, which are critical for accurate diagnostics. However, the morphology of Alternaria is quite complex, and precise characterization can be laborious, time-consuming, and often restricted to experts in this field. To make morphology characterization easier and more broadly accessible, a generalized statistical model was developed for the three-dimensional geometric structure of the sporulation apparatus. The model is inspired by the widely used grammar-based models for plants, Lindenmayer-systems, which build structure by repeated application of rules for growth. Adjusting the parameters of the underlying probability distributions yields variations in the morphology, and thus the approach provides an excellent tool for exploring the morphology of Alternaria under different assumptions, as well as understanding how it is largely the consequence of local rules for growth. Further, different choices of parameters lead to different model groups, which can then be visually compared to published descriptions or microscopy images to validate parameters for species-specific models. The approach supports automated analysis, as the models can be fit to image data using statistical inference, and the explicit representation of the geometry allows the accurate computation of any morphological quantity. Furthermore, because the model can encode the statistical variation of geometric parameters for different species, it will allow automated species identification from microscopy images using statistical inference. In summary, the approach supports visualization of morphology, automated quantification of phenotype structure, and identification based on form. PMID:22036294

  2. Influence of environmental parameters on mycotoxin production by Alternaria arborescens.

    PubMed

    Vaquera, Sandra; Patriarca, Andrea; Fernández Pinto, V

    2016-02-16

    Alternaria arborescens has been reported as a common fungal species invading tomatoes and is capable of producing several mycotoxins in infected plants, fruits and in agricultural commodities. Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants of food. This species can produce these toxic metabolites together with AAL toxins (Alternaria alternata f. sp. lycopersicum toxins), which can act as inhibitors of sphingolipid biosynthesis. The objective of this study was to determine the effect of water activity (aw, 0.995, 0.975, 0.950) and temperature (6, 15, 20, 25 and 30 °C) on mycotoxin production by A. arborescens on a synthetic tomato medium. The optimum production of AOH and AME occurred at 0.975 aw after 40 days of incubation at 30 °C. The maximum TeA accumulation was observed at 0.975 aw and 25 °C and at 0.950 aw and 30 °C. AAL TA was produced in higher quantities at 0.995 aw and 30 °C. At 6 °C no quantifiable levels of AOH or AME were detected, but significant amounts of TeA were produced at 0.975 aw. In general, high aw levels and high temperatures were favorable for mycotoxin production. The greatest accumulation of all four toxins occurred at 0.975 aw and 30 °C. The results obtained here could be extrapolated to evaluate the risk of tomato fruits and tomato products contamination caused by these toxins. PMID:26708802

  3. A new compound from an endophytic fungus Alternaria tenuissima.

    PubMed

    Wu, Wen-Bin; Yue, Gao-Chao; Huang, Qi-Lin; Sun, Ling-Ling; Zhang, Wen

    2014-01-01

    A new secondary metabolite, named altertoxin IV (1), together with altertoxin II (2), was isolated from the fermentation broth of Alternaria tenuissima, an endophytic fungal strain residing in the stem of Tribulus terrestris L. The structure of new compound 1 was established by HR-ESI-MS, multinuclear NMR spectroscopy, and single crystal X-ray diffraction method. In their in vitro bioassay, compound 2 exhibited moderate cytotoxic activity against PC-3 cell lines with an IC50 value of 14.28 μM. PMID:24660902

  4. Ultraviolet-Resistant Bacterial Spores

    NASA Technical Reports Server (NTRS)

    Venkateswaran, Kasthuri; Newcombe, David; LaDuc, Myron T.; Osman, Shariff R.

    2007-01-01

    A document summarizes a study in which it was found that spores of the SAFR-032 strain of Bacillus pumilus can survive doses of ultraviolet (UV) radiation, radiation, and hydrogen peroxide in proportions much greater than those of other bacteria. The study was part of a continuing effort to understand the survivability of bacteria under harsh conditions and develop means of sterilizing spacecraft to prevent biocontamination of Mars that could interfere with the search for life there.

  5. Sterilizing Effects of High-Intensity Airborne Sonic and Ultrasonic Waves

    PubMed Central

    Pisano, Michael A.; Boucher, Raymond M. G.; Alcamo, I. Edward

    1966-01-01

    The lethal effects of high-intensity airborne sonic (9.9 kc/sec) and ultrasonic waves (30.4 kc/sec) on spores of Bacillus subtilis var. niger ATCC 9372 were determined. The spores, which were deposited on filter-paper strips, were exposed to sound waves for periods varying from 1 to 8 hr, at a temperature of 40 C and a relative humidity of 40%. Significant reductions in the viable counts of spores exposed to airborne sonic or ultrasonic irradiations were obtained. The antibacterial activity of airborne sound waves varied with the sound intensity level, the period of irradiation, and the distance of the sample from the sound source. At similar intensity levels, the amplitude of motion of the sound waves appeared to be a factor in acoustic sterilization. Images Fig. 1 PMID:4961527

  6. Modelling the impact of fungal spore ice nuclei on clouds and precipitation

    NASA Astrophysics Data System (ADS)

    Sesartic, Ana; Lohmann, Ulrike; Storelvmo, Trude

    2013-04-01

    Fungal spores are part of the atmospheric bioaerosols such as pollen or bacteria. Interest in bioaerosols is mainly related to their health effects, impacts on agriculture, ice nucleation and cloud droplet activation, as well as atmospheric chemistry (Morris et al. 2011). Spores of some fungal species have been found to be very efficient ice nuclei, e.g. in laboratory studies by Pouleur et al. (1992). Recent field studies by Poehlker et al. (2012) found that fungal spores are important contributors to the development of mist and clouds in rainforest ecosystems. In our study we investigated the impact of fungal spores acting as ice nuclei on clouds and precipitation on a global scale. Fungal spores as a new aerosol species were introduced into the global climate model ECHAM5-HAM (Sesartic et al. 2012) using observational fungal spore data compiled by Sesartic & Dallafior (2011). The addition of fungal spores lead to only minor changes in cloud formation and precipitation on a global level, however, changes in the liquid water path and ice water path as well as stratiform precipitation in the model were observed in the boreal regions where tundra and forests act as sources of fungal spores. This goes hand in hand with a decreased ice crystal number concentration and increased effective radius of ice crystals. An increase in stratiform precipitation and snowfall can be observed in those regions as well. Although fungal spores contribute to heterogeneous freezing, their impact in the model was reduced by their low numbers compared to other heterogeneous ice nuclei. These results for fungal spores are comparable to the ones achieved with bacteria (Sesartic et al. 2012). REFERENCES Morris, C. E. et al. 2011: Microbiology and atmospheric processes: research challenges concerning the impact of airborne micro-organisms on the atmosphere and climate, Biogeosciences, 8, 17-25. Poehlker, C. et al. 2012: Biogenic Potassium Salt Particles as Seeds for Secondary Organic Aerosol

  7. Can airborne fungal allergens pass through an air-conditioning system. [Aspergillus fumigatus

    SciTech Connect

    Elixmann, J.H. ); Linskens, H.F.; Schata, M.; Jorde, W. )

    1989-01-01

    Fungal spores, an important fraction of aeroplankton particles, can be filtered in an air-conditioning system, resulting in a drastic reduction of the spore count in the air-conditioned rooms. Nevertheless, using the EISA inhibition test against Aspergillus fumigatus, it was found that air samples from air-conditioned rooms show inhibition of the serum activity of a highly sensitized patient. There is evidence that airborne allergens can pass both coarse and fine filters of an air-conditioning system.

  8. Reaerosolization of Fluidized Spores in Ventilation Systems▿

    PubMed Central

    Krauter, Paula; Biermann, Arthur

    2007-01-01

    This project examined dry, fluidized spore reaerosolization in a heating, ventilating, and air conditioning duct system. Experiments using spores of Bacillus atrophaeus, a nonpathogenic surrogate for Bacillus anthracis, were conducted to delineate the extent of spore reaerosolization behavior under normal indoor airflow conditions. Short-term (five air-volume exchanges), long-term (up to 21,000 air-volume exchanges), and cycled (on-off) reaerosolization tests were conducted using two common duct materials. Spores were released into the test apparatus in turbulent airflow (Reynolds number, 26,000). After the initial pulse of spores (approximately 1010 to 1011 viable spores) was released, high-efficiency particulate air filters were added to the air intake. Airflow was again used to perturb the spores that had previously deposited onto the duct. Resuspension rates on both steel and plastic duct materials were between 10−3 and 10−5 per second, which decreased to 10 times less than initial rates within 30 min. Pulsed flow caused an initial spike in spore resuspension concentration that rapidly decreased. The resuspension rates were greater than those predicted by resuspension models for contamination in the environment, a result attributed to surface roughness differences. There was no difference between spore reaerosolization from metal and that from plastic duct surfaces over 5 hours of constant airflow. The spores that deposited onto the duct remained a persistent source of contamination over a period of several hours. PMID:17293522

  9. The walk and jump of Equisetum spores.

    PubMed

    Marmottant, Philippe; Ponomarenko, Alexandre; Bienaimé, Diane

    2013-11-01

    Equisetum plants (horsetails) reproduce by producing tiny spherical spores that are typically 50 µm in diameter. The spores have four elaters, which are flexible ribbon-like appendages that are initially wrapped around the main spore body and that deploy upon drying or fold back in humid air. If elaters are believed to help dispersal, the exact mechanism for spore motion remains unclear in the literature. In this manuscript, we present observations of the 'walks' and 'jumps' of Equisetum spores, which are novel types of spore locomotion mechanisms compared to the ones of other spores. Walks are driven by humidity cycles, each cycle inducing a small step in a random direction. The dispersal range from the walk is limited, but the walk provides key steps to either exit the sporangium or to reorient and refold. Jumps occur when the spores suddenly thrust themselves after being tightly folded. They result in a very efficient dispersal: even spores jumping from the ground can catch the wind again, whereas non-jumping spores stay on the ground. The understanding of these movements, which are solely driven by humidity variations, conveys biomimetic inspiration for a new class of self-propelled objects. PMID:24026816

  10. Mycotoxin production by Alternaria strains isolated from Argentinean wheat.

    PubMed

    Patriarca, A; Azcarate, M P; Terminiello, L; Fernández Pinto, V

    2007-11-01

    The toxigenic potential of Alternaria strains isolated from Argentinean wheat was investigated. A total of 123 strains were assayed for the production of tenuazonic acid (TA), alternariol (AOH) and alternariol monomethyl ether (AME). All but one of the isolates were able to produce at least one of the three mycotoxins. TA was produced by 72% of the strains (1-14782 mg/kg), AOH by 87% (4-622 mg/kg) and AME by 91% (7-2625 mg/kg). The average level of TA detected for all strains (1757 mg/kg) was higher than the average level of both alternariols (162 mg/kg for AOH and 620 mg/kg for AME). TA was the toxin produced at the highest concentration but in lower frequency. Most of the strains were able to synthesize more than one toxin: 74 isolates (60%) were positive for all three toxins, 30 (24%) for both AOH and AME, 5 (4%) for both TA and AME, and 2 (2%) for TA and AOH. The widespread occurrence of Alternaria in wheat and its ability to produce mycotoxins suggests the possible occurrence of its toxins in wheat naturally infected with this fungus. PMID:17804107

  11. Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs

    PubMed Central

    Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M. A.; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E.; Casadevall, Arturo

    2015-01-01

    The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis. PMID:26711773

  12. Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs.

    PubMed

    Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M A; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E; Casadevall, Arturo; Gonçalves, Teresa

    2016-03-01

    The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis. PMID:26711773

  13. Evaluation of three portable samplers for monitoring airborne fungi

    NASA Technical Reports Server (NTRS)

    Mehta, S. K.; Mishra, S. K.; Pierson, D. L.

    1996-01-01

    Airborne fungi were monitored at five sample sites with the Burkard portable, the RCS Plus, and the SAS Super 90 air samplers; the Andersen 2-stage impactor was used for comparison. All samplers were calibrated before being used simultaneously to collect 100-liter samples at each site. The Andersen and Burkard samplers retrieved equivalent volumes of airborne fungi; the SAS Super 90 and RCS Plus measurements did not differ from each other but were significantly lower than those obtained with the Andersen or Burkard samplers. Total fungal counts correlated linearly with Cladosporium and Penicillium counts. Alternaria species, although present at all sites, did not correlate with total count or with amounts of any other fungal genera. Sampler and location significantly influenced fungal counts, but no interactions between samplers and locations were found.

  14. Identifying Airborne Pathogens in Time to Respond

    SciTech Connect

    Hazi, A

    2006-01-25

    Among the possible terrorist activities that might threaten national security is the release of an airborne pathogen such as anthrax. Because the potential damage to human health could be severe, experts consider 1 minute to be an operationally useful time limit for identifying the pathogen and taking action. Many commercial systems can identify airborne pathogenic microbes, but they take days or, at best, hours to produce results. The Department of Homeland Security (DHS) and other U.S. government agencies are interested in finding a faster approach. To answer this national need, a Livermore team, led by scientist Eric Gard, has developed the bioaerosol mass spectrometry (BAMS) system--the only instrument that can detect and identify spores at low concentrations in less than 1 minute. BAMS can successfully distinguish between two related but different spore species. It can also sort out a single spore from thousands of other particles--biological and nonbiological--with no false positives. The BAMS team won a 2005 R&D 100 Award for developing the system. Livermore's Laboratory Directed Research and Development (LDRD) Program funded the biomedical aspects of the BAMS project, and the Department of Defense's Technical Support Working Group and Defense Advanced Research Project Agency funded the biodefense efforts. Developing a detection system that can analyze small samples so quickly has been challenging. Livermore engineer Vincent Riot, who worked on the BAMS project, explains, ''A typical spore weighs approximately one-trillionth of a gram and is dispersed in the atmosphere, which contains naturally occurring particles that could be present at concentrations thousands of times higher. Previous systems also had difficulty separating benign organisms from those that are pathogenic but very similar, which has resulted in false alarms''.

  15. Use of microbial spores as a biocatalyst

    SciTech Connect

    Murata, Kousaku . Research Inst. for Food Science)

    1993-01-01

    Endospores of a bacterium Bacillus subtilis and ascospores of a yeast Saccharomyces cerevisiae contained almost all the activities for the same enzymes as vegetative cells. The biotechnological potential of spores was studied by selecting adenosine 5[prime]-triphosphatase and alkaline phosphatase in bacterial and yeast spores, respectively, as model enzymes. The activity of both enzymes was efficiently expressed when the spores were treated by physical (sonication or electric field pulse) and chemical (organic solvents or detergents) methods. The yeast spores were immobilized in polyacrylamide gel without any appreciable loss of activity. The immobilized spores were packed in a column and used successfully for the continuous reactions of alkaline phosphatase and glyoxalase I. The microbial spores were confirmed to be promising as a biocatalyst for the production of useful chemicals in bioreactor systems.

  16. On the fate of ingested Bacillus spores.

    PubMed

    Spinosa, M R; Braccini, T; Ricca, E; De Felice, M; Morelli, L; Pozzi, G; Oggioni, M R

    2000-06-01

    Spores of various Bacillus species, including B. subtilis, B. cereus and B. clausii, are used as probiotics, although they are generally absent from the normal microflora of man. We used two nonpathogenic Bacillus species, B. subtilis and B. clausii, to follow the fate of spores inoculated intragastrically in mice. We did not find detectable amounts of vegetative cells in intestinal samples, probably because of high toxicity of the conjugated bile salt taurodeoxycholic acid against Bacillus species. Both spores and cells were detected in the lymph nodes and spleen of one mouse. Our results indicate that Bacillus is present in the intestinal tract solely as spores and that nonpathogenic Bacillus spores may germinate in lymphoid organs, a finding reminiscent of B. anthracis germination in macrophages. These results indicate that any claimed probiotic effect of B. subtilis should be due to spores or, alternatively, to vegetative growth outside the intestine. PMID:10919516

  17. Identification of a Nosema bombycis (Microsporidia) spore wall protein corresponding to spore phagocytosis.

    PubMed

    Cai, Shunfeng; Lu, Xingmeng; Qiu, Haihong; Li, Mingqian; Feng, Zhenzhen

    2011-08-01

    Life-cycle stages of the microsporidia Nosema bombycis, the pathogen causing silkworm pebrine, were separated and purified by an improved method of Percoll-gradient centrifugation. Soluble protein fractions of late sporoblasts (spore precursor cells) and mature spores were analysed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Protein spots were recovered from gels and analysed by mass spectrometry. The most abundant differential protein spot was identified by database search to be a hypothetical spore wall protein. Using immunoelectron microscopy, we demonstrated that HSWP5 is localized to the exospore of mature spores and renamed it as spore wall protein 5 (NbSWP5). Further spore phagocytosis assays indicated that NbSWP5 can protect spores from phagocytic uptake by cultured insect cells. This spore wall protein may function both for structural integrity and in modulating host cell invasion. PMID:21756420

  18. Inducing and Quantifying Clostridium difficile Spore Formation.

    PubMed

    Shen, Aimee; Fimlaid, Kelly A; Pishdadian, Keyan

    2016-01-01

    The Gram-positive nosocomial pathogen Clostridium difficile induces sporulation during growth in the gastrointestinal tract. Sporulation is necessary for this obligate anaerobe to form metabolically dormant spores that can resist antibiotic treatment, survive exit from the mammalian host, and transmit C. difficile infections. In this chapter, we describe a method for inducing C. difficile sporulation in vitro. This method can be used to study sporulation and maximize spore purification yields for a number of C. difficile strain backgrounds. We also describe procedures for visualizing spore formation using phase-contrast microscopy and for quantifying the efficiency of sporulation using heat resistance as a measure of functional spore formation. PMID:27507338

  19. Seasonal and diurnal patterns of spore release can significantly affect the proportion of spores expected to undergo long-distance dispersal.

    PubMed

    Savage, David; Barbetti, Martin J; MacLeod, William J; Salam, Moin U; Renton, Michael

    2012-04-01

    Many of the fungal pathogens that threaten agricultural and natural systems undergo wind-assisted dispersal. During turbulent wind conditions, long-distance dispersal can occur, and airborne spores are carried over distances greater than the mean. The occurrence of long-distance dispersal is an important ecological process, as it can drastically increase the extent to which pathogen epidemics spread across a landscape, result in rapid transmission of disease to previously uninfected areas, and influence the spatial structure of pathogen populations in fragmented landscapes. Since the timing of spore release determines the wind conditions that prevail over a dispersal event, this timing is likely to affect the probability of long-distance dispersal occurring. Using a Lagrangian stochastic model, we test the effect of seasonal and diurnal variation in the release of spores on wind-assisted dispersal. Spores released during the hottest part of the day are shown to be more likely to undergo long-distance dispersal than those released at other times. Furthermore, interactions are shown to occur between seasonal and diurnal patterns of release. These results have important consequences for further modelling of wind-assisted dispersal and the use of models to predict the spread of fungal pathogens and resulting population and epidemic dynamics. PMID:21968611

  20. Phylogenetic, Morphological, and Pathogenic Characterization of Alternaria Species Associated with Fruit Rot of Blueberry in California.

    PubMed

    Zhu, X Q; Xiao, C L

    2015-12-01

    Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruit. The aims of this study were to characterize Alternaria isolates using morphological and molecular approaches and test their pathogenicity to blueberry fruit. Alternaria spp. isolates were collected from decayed blueberry fruit in the Central Valley of California during 2012 and 2013. In total, 283 isolates were obtained and five species of Alternaria, including Alternaria alternata, A. tenuissima, A. arborescens, A. infectoria, and A. rosae, were identified based on DNA sequences of the plasma membrane ATPase, Alt a1 and Calmodulin gene regions in combination with morphological characters of the culture and sporulation. Of the 283 isolates, 61.5% were identified as A. alternata, 32.9% were A. arborescens, 5.0% were A. tenuissima, and only one isolate of A. infectoria and one isolate of A. rosae were found. These fungi were able to grow at temperatures from 0 to 35°C, and mycelial growth was arrested at 40°C. Optimal radial growth occurred between 20 to 30°C. Pathogenicity tests showed that all five Alternaria spp. were pathogenic on blueberry fruit at 0, 4, and 20°C, with A. alternata, A. arborescens, and A. tenuissima being the most virulent species, followed by A. infectoria and A. rosae. Previously A. tenuissima has been reported to be the primary cause of Alternaria fruit rot of blueberry worldwide. Our results indicated that the species composition of Alternaria responsible for Alternaria fruit rot in blueberry can be dependent on geographical region. A. alternata, A. arborescens, A. infectoria, and A. rosae are reported for the first time on blueberry in California. This is also the first report of A. infectoria and A. rosae infecting blueberry fruit. PMID:26267542

  1. Electron Beam Irradiation Dose Dependently Damages the Bacillus Spore Coat and Spore Membrane

    PubMed Central

    Fiester, S. E.; Helfinstine, S. L.; Redfearn, J. C.; Uribe, R. M.; Woolverton, C. J.

    2012-01-01

    Effective control of spore-forming bacilli begs suitable physical or chemical methods. While many spore inactivation techniques have been proven effective, electron beam (EB) irradiation has been frequently chosen to eradicate Bacillus spores. Despite its widespread use, there are limited data evaluating the effects of EB irradiation on Bacillus spores. To study this, B. atrophaeus spores were purified, suspended in sterile, distilled water, and irradiated with EB (up to 20 kGy). Irradiated spores were found (1) to contain structural damage as observed by electron microscopy, (2) to have spilled cytoplasmic contents as measured by spectroscopy, (3) to have reduced membrane integrity as determined by fluorescence cytometry, and (4) to have fragmented genomic DNA as measured by gel electrophoresis, all in a dose-dependent manner. Additionally, cytometry data reveal decreased spore size, increased surface alterations, and increased uptake of propidium iodide, with increasing EB dose, suggesting spore coat alterations with membrane damage, prior to loss of spore viability. The present study suggests that EB irradiation of spores in water results in substantial structural damage of the spore coat and inner membrane, and that, along with DNA fragmentation, results in dose-dependent spore inactivation. PMID:22319535

  2. Distinction of broken cellular wall Ganoderma lucidum spores and G. lucidum spores using FTIR microspectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Xianliang; Liu, Xingcun; Sheng, Daping; Huang, Dake; Li, Weizu; Wang, Xin

    2012-11-01

    In this paper, FTIR microspectroscopy was used to identify broken cellular wall Ganoderma lucidum spores and G. lucidum spores. For IR spectra, broken cellular wall G. lucidum spores and G. lucidum spores were mainly different in the regions of 3000-2800, 1660-1600, 1400-1200 and 1100-1000 cm-1. For curve fitting, the results showed the differences in the protein secondary structures and the polysaccharide structures/content between broken cellular wall G. lucidum spores and G. lucidum spores. Moreover, the value of A1078/A1741 might be a potentially useful factor to distinguish broken cellular wall G. lucidum spores from G. lucidum spores. Additionally, FTIR microspectroscopy could identify broken cellular wall G. lucidum spores and G. lucidum spores accurately when it was combined with hierarchical cluster analysis. The result suggests FTIR microspectroscopy is very simple and efficient for distinction of broken cellular wall G. lucidum spores and G. lucidum spores. The result also indicates FTIR microspectroscopy may be useful for TCM identification.

  3. Anthrax Toxins in Context of Bacillus anthracis Spores and Spore Germination

    PubMed Central

    Cote, Christopher K.; Welkos, Susan L.

    2015-01-01

    The interaction of anthrax toxin or toxin components with B. anthracis spores has been demonstrated. Germinating spores can produce significant amounts of toxin components very soon after the initiation of germination. In this review, we will summarize the work performed that has led to our understanding of toxin and spore interactions and discuss the complexities associated with these interactions. PMID:26287244

  4. Bacillus anthracis Spore Surface Protein BclA Mediates Complement Factor H Binding to Spores and Promotes Spore Persistence

    PubMed Central

    Gu, Chunfang; Martinez-Moczygemba, Margarita; Herold, Jennifer; Botto, Marina; Wetsel, Rick A.; Xu, Yi

    2016-01-01

    Spores of Bacillus anthracis, the causative agent of anthrax, are known to persist in the host lungs for prolonged periods of time, however the underlying mechanism is poorly understood. In this study, we demonstrated that BclA, a major surface protein of B. anthracis spores, mediated direct binding of complement factor H (CFH) to spores. The surface bound CFH retained its regulatory cofactor activity resulting in C3 degradation and inhibition of downstream complement activation. By comparing results from wild type C57BL/6 mice and complement deficient mice, we further showed that BclA significantly contributed to spore persistence in the mouse lungs and dampened antibody responses to spores in a complement C3-dependent manner. In addition, prior exposure to BclA deletion spores (ΔbclA) provided significant protection against lethal challenges by B. anthracis, whereas the isogenic parent spores did not, indicating that BclA may also impair protective immunity. These results describe for the first time an immune inhibition mechanism of B. anthracis mediated by BclA and CFH that promotes spore persistence in vivo. The findings also suggested an important role of complement in persistent infections and thus have broad implications. PMID:27304426

  5. Bacillus anthracis Spore Surface Protein BclA Mediates Complement Factor H Binding to Spores and Promotes Spore Persistence.

    PubMed

    Wang, Yanyu; Jenkins, Sarah A; Gu, Chunfang; Shree, Ankita; Martinez-Moczygemba, Margarita; Herold, Jennifer; Botto, Marina; Wetsel, Rick A; Xu, Yi

    2016-06-01

    Spores of Bacillus anthracis, the causative agent of anthrax, are known to persist in the host lungs for prolonged periods of time, however the underlying mechanism is poorly understood. In this study, we demonstrated that BclA, a major surface protein of B. anthracis spores, mediated direct binding of complement factor H (CFH) to spores. The surface bound CFH retained its regulatory cofactor activity resulting in C3 degradation and inhibition of downstream complement activation. By comparing results from wild type C57BL/6 mice and complement deficient mice, we further showed that BclA significantly contributed to spore persistence in the mouse lungs and dampened antibody responses to spores in a complement C3-dependent manner. In addition, prior exposure to BclA deletion spores (ΔbclA) provided significant protection against lethal challenges by B. anthracis, whereas the isogenic parent spores did not, indicating that BclA may also impair protective immunity. These results describe for the first time an immune inhibition mechanism of B. anthracis mediated by BclA and CFH that promotes spore persistence in vivo. The findings also suggested an important role of complement in persistent infections and thus have broad implications. PMID:27304426

  6. FATE OF BACILLUS SPHAERICUS 2362 SPORES IN NONTARGET INVERTEBRATES

    EPA Science Inventory

    Predatory stonefly larvae (Paragnetina media) acquired B. sphaericus spores by eating spore-laden midge larvae. eaf shredding stonefly larvae (Pteronarcys proteus) and cranefly larvae (Tipula abdominalis) acquired spores by feeding on contaminated leaf discs. pon switching to unc...

  7. Spore heat resistance and specific mineralization.

    PubMed Central

    Bender, G R; Marquis, R E

    1985-01-01

    Spores of Bacillus megaterium ATCC 19213, Bacillus subtilis niger and Bacillus stearothermophilus ATCC 7953 were converted to fully demineralized, but viable, H forms by controlled acid titration. H forms were more heat sensitive than were native forms, but z values were greater for killing of H spores than those for native spores. Therefore, the differences in heat sensitivity between native and H forms decreased with increasing killing temperature. The increase in heat sensitivity associated with demineralization did not appear to be due to damage to cortex lytic enzymes of the germination system because it could not be moderated by decoating heated H spores and plating them on medium with added lysozyme. H spores could be remineralized by means of back titration with appropriate base solutions. The remineralized spores, except for the Na form, were then more heat resistant than were H spores. Ca and Mn were more effective in restoring resistance than were Mg and K. Generally, the remineralized forms (except for the Na form) had z values greater than those of the native forms but still less than those of the H forms. At lower killing temperatures, the reinstatement of resistance could be related to the extent of remineralization. However, at higher killing temperatures, only a fraction of the mineral was effective in restoring resistance, and higher levels of remineralization did not result in greater resistance. Mineralization is clearly an important factor in spore heat resistance, but the relationship between resistance and mineralization is complex and dependent on killing temperature. PMID:3937495

  8. Spore formation in plants: sporocyteless and more.

    PubMed

    Yuan, Li; Sundaresan, Venkatesan

    2015-01-01

    Plant reproduction is initiated by the specification of sporocytes that form haploid spores through meiosis. A new study in Arabidopsis published in Cell Research shows how the product of sporocyteless/nozzle, a key gene in this process, partners with co-repressors and transcription factors to promote spore formation, and draws interesting parallels with fungi. PMID:25512340

  9. Plasma Assisted Decontamination of Bacterial Spores

    PubMed Central

    Kuo, Spencer P

    2008-01-01

    The efficacy and mechanism of killing bacterial spores by a plasma torch is studied. Bacterial-spore (Bacillus cereus) suspension is inoculated onto glass/paper slide-coupons and desiccated into dry samples, and inoculated into well-microplate as wet sample. The exposure distance of all samples is 4 cm from the nozzle of the torch. In the experiment, paper slide-coupon is inserted inside an envelope. The kill times on spores in three types of samples are measured to be about 3, 9, and 24 seconds. The changes in the morphology and shape of still viable spores in treated wet samples are recorded by scanning electron and atomic force microscopes. The loss of appendages and exosporium in the structure and squashed/flattened cell shape are observed. The emission spectroscopy of the torch indicates that the plasma effluent carries abundant reactive atomic oxygen, which is responsible for the destruction of spores. PMID:19662115

  10. Occurrence of Leaf Blight on Cosmos Caused by Alternaria cosmosa in Korea

    PubMed Central

    Deng, Jian Xin; Lee, Ji Hye; Paul, Narayan Chandra; Cho, Hye Sun; Lee, Hyang Burm; Yu, Seung Hun

    2015-01-01

    In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus) leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea. PMID:25774114

  11. INOCULATION STRATEGIES TO ASSESS BIOLOGICAL INTERACTIONS BETWEEN FUSARIUM AND ALTERNARIA SPECIES INFECTING SORGHUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three bioassays were assessed for experimental utility to either characterize fungal species potentially pathogenic to sorghum [Sorghum bicolor (L.) Moench] or to screen germplasm for advancement in breeding programs. Isolates of species commonly associated with sorghum, Alternaria alternata, Fusari...

  12. Annual distribution of allergenic fungal spores in atmospheric particulate matter in the Eastern Mediterranean; a comparative study between ergosterol and quantitative PCR analysis

    NASA Astrophysics Data System (ADS)

    Lang-Yona, N.; Dannemiller, K.; Yamamoto, N.; Burshtein, N.; Peccia, J.; Yarden, O.; Rudich, Y.

    2012-03-01

    Airborne fungal spores are an important fraction of atmospheric particulate matter and are major causative agents of allergenic and infectious diseases. Predicting the variability and species of allergy-causing fungal spores requires detailed and reliable methods for identification and quantification. There are diverse methods for their detection in the atmosphere and in the indoor environments; yet, it is important to optimize suitable methods for characterization of fungal spores in atmospheric samples. In this study we sampled and characterized total and specific airborne fungal spores from PM10 samples collected in Rehovot, Israel over an entire year. The total fungal spore concentrations vary throughout the year although the species variability was nearly the same. Seasonal equivalent spore concentrations analyzed by real-time quantitative-PCR-based methods were fall > winter > spring > summer. Reported concentrations based on ergosterol analysis for the same samples were and fall > spring > winter > summer. Correlation between the two analytical methods was found only for the spring season. These poor associations may be due to the per-spore ergosterol variations that arise from both varying production rates, as well as molecular degradation of ergosterol. While conversion of genome copies to spore concentration is not yet straightforward, the potential for improving this conversion and the ability of qPCR to identify groups of fungi or specific species makes this method preferable for environmental spore quantification. Identifying tools for establishing the relation between the presence of species and the actual ability to induce allergies is still needed in order to predict the effect on human health.

  13. Annual distribution of allergenic fungal spores in atmospheric particulate matter in the eastern mediterranean; a comparative study between ergosterol and quantitative PCR analysis

    NASA Astrophysics Data System (ADS)

    Lang-Yona, N.; Dannemiller, K.; Yamamoto, N.; Burshtein, N.; Peccia, J.; Yarden, O.; Rudich, Y.

    2011-10-01

    Airborne fungal spores are an important fraction of atmospheric particulate matter and are major causative agents of allergenic and infectious diseases. Predicting the variability and species of allergy-causing fungal spores requires detailed and reliable methods for identification and quantification. There are diverse methods for their detection in the atmosphere and in the indoor environments; yet, it is important to optimize suitable methods for characterization of fungal spores in atmospheric samples. In this study we sampled and characterized total and specific airborne fungal spores from PM10 samples collected in Rohovot, Israel over an entire year. The total fungal spore concentrations vary throughout the year although the species variability was nearly the same. Seasonal equivalent spore concentrations analyzed by real-time quantitative-PCR-based methods were fall > winter > spring > summer. Reported concentrations based on ergosterol analysis for the same samples were and fall > spring > winter > summer. Correlation between the two analytical methods was found only for the spring season. These poor associations may be due to the per-spore ergosterol variations that arise from both varying production rates, as well as molecular degradation of ergosterol. While conversion of genome copies to spore concentration is not yet straightforward, the potential for improving this conversion and the ability of qPCR to identify groups of fungi or specific species makes this method preferable for environmental spore quantification. Identifying tools for establishing the relation between the presence of species and the actual ability to induce allergies is still needed in order to predict the effect on human health.

  14. Alternaria-derived serine protease activity drives IL-33–mediated asthma exacerbations

    PubMed Central

    Snelgrove, Robert J.; Gregory, Lisa G.; Peiró, Teresa; Akthar, Samia; Campbell, Gaynor A.; Walker, Simone A.; Lloyd, Clare M.

    2014-01-01

    Background The fungal allergen Alternaria alternata is implicated in severe asthma and rapid onset life-threatening exacerbations of disease. However, the mechanisms that underlie this severe pathogenicity remain unclear. Objective We sought to investigate the mechanism whereby Alternaria was capable of initiating severe, rapid onset allergic inflammation. Methods IL-33 levels were quantified in wild-type and ST2−/− mice that lacked the IL-33 receptor given inhaled house dust mite, cat dander, or Alternaria, and the effect of inhibiting allergen-specific protease activities on IL-33 levels was assessed. An exacerbation model of allergic airway disease was established whereby mice were sensitized with house dust mite before subsequently being challenged with Alternaria (with or without serine protease activity), and inflammation, remodeling, and lung function assessed 24 hours later. Results Alternaria, but not other common aeroallergens, possessed intrinsic serine protease activity that elicited the rapid release of IL-33 into the airways of mice through a mechanism that was dependent upon the activation of protease activated receptor-2 and adenosine triphosphate signaling. The unique capacity of Alternaria to drive this early IL-33 release resulted in a greater pulmonary inflammation by 24 hours after challenge relative to the common aeroallergen house dust mite. Furthermore, this Alternaria serine protease–IL-33 axis triggered a rapid, augmented inflammation, mucus release, and loss of lung function in our exacerbation model. Conclusion Alternaria-specific serine protease activity causes rapid IL-33 release, which underlies the development of a robust TH2 inflammation and exacerbation of allergic airway disease. PMID:24636086

  15. The effect of outdoor fungal spore concentrations on daily asthma severity.

    PubMed Central

    Delfino, R J; Zeiger, R S; Seltzer, J M; Street, D H; Matteucci, R M; Anderson, P R; Koutrakis, P

    1997-01-01

    The relationship between day-to-day changes in asthma severity and combined exposures to community air pollutants and aeroallergens remains to be clearly defined. We examined the effects of outdoor air pollutants, fungi, and pollen on asthma. Twenty-two asthmatics ages 9-46 years were followed for 8 weeks (9 May-3 July 1994) in a semirural Southern California community around the air inversion base elevation (1,200 ft). Daily diary responses included asthma symptom severity (6 levels), morning and evening peak expiratory flow rates (PEFR), and as-needed beta-agonist inhaler use. Exposures included 24-hr outdoor concentrations of fungi, pollen, and particulate matter with a diameter < 10 microns (PM10; maximum = 51 micrograms/m3) and 12-hour day-time personal ozone (O3) measurements (90th percentile = 38 ppb). Random effects longitudinal regression models controlled for autocorrelation and weather. Higher temperatures were strongly protective, probably due to air conditioning use and diminished indoor allergens during hot, dry periods. Controlling for weather, total fungal spore concentrations were associated with all outcomes: per minimum to 90th percentile increase of nearly 4,000 spores/m3, asthma symptom scores increased 0.36 (95% CI, 0.16-0.56), inhaler use increased 0.33 puffs (95% CI, -0.02-0.69), and evening PEFR decreased 12.1 l/min (95% CI, -1.8-22.3). These associations were greatly enhanced by examining certain fungal types (e.g., Alternaria, basidiospores, and hyphal fragments) and stratifying on 16 asthmatics allergic to tested deuteromycete fungi. There were no significant associations to low levels of pollen or O3, but inhaler use was associated with PM10 (0.15 inhaler puffs/10 micrograms/m3; p < 0.02). These findings suggest that exposure to fungal spores can adversely effect the daily respiratory status of some asthmatics. Images Figure 1. PMID:9288497

  16. Constructing Fluorogenic Bacillus Spores (F-Spores) via Hydrophobic Decoration of Coat Proteins

    PubMed Central

    Ferencko, Linda; Rotman, Boris

    2010-01-01

    Background Bacterial spores are protected by a coat consisting of about 60 different proteins assembled as a biochemically complex structure with intriguing morphological and mechanical properties. Historically, the coat has been considered a static structure providing rigidity and mainly acting as a sieve to exclude exogenous large toxic molecules, such as lytic enzymes. Over recent years, however, new information about the coat's architecture and function have emerged from experiments using innovative tools such as automated scanning microscopy, and high resolution atomic force microscopy. Principal Findings Using thin-section electron microscopy, we found that the coat of Bacillus spores has topologically specific proteins forming a layer that is identifiable because it spontaneously becomes decorated with hydrophobic fluorogenic probes from the milieu. Moreover, spores with decorated coat proteins (termed F-spores) have the unexpected attribute of responding to external germination signals by generating intense fluorescence. Fluorescence data from diverse experimental designs, including F-spores constructed from five different Bacilli species, indicated that the fluorogenic ability of F-spores is under control of a putative germination-dependent mechanism. Conclusions This work uncovers a novel attribute of spore-coat proteins that we exploited to decorate a specific layer imparting germination-dependent fluorogenicity to F-spores. We expect that F-spores will provide a model system to gain new insights into structure/function dynamics of spore-coat proteins. PMID:20174569

  17. Slow Leakage of Ca-Dipicolinic Acid from Individual Bacillus Spores during Initiation of Spore Germination

    PubMed Central

    Wang, Shiwei; Setlow, Peter

    2015-01-01

    When exposed to nutrient or nonnutrient germinants, individual Bacillus spores can return to life through germination followed by outgrowth. Laser tweezers, Raman spectroscopy, and either differential interference contrast or phase-contrast microscopy were used to analyze the slow dipicolinic acid (DPA) leakage (normally ∼20% of spore DPA) from individual spores that takes place prior to the lag time, Tlag, when spores begin rapid release of remaining DPA. Major conclusions from this work with Bacillus subtilis spores were as follows: (i) slow DPA leakage from wild-type spores germinating with nutrients did not begin immediately after nutrient exposure but only at a later heterogeneous time T1; (ii) the period of slow DPA leakage (ΔTleakage = Tlag − T1) was heterogeneous among individual spores, although the amount of DPA released in this period was relatively constant; (iii) increases in germination temperature significantly decreased T1 times but increased values of ΔTleakage; (iv) upon germination with l-valine for 10 min followed by addition of d-alanine to block further germination, all germinated spores had T1 times of less than 10 min, suggesting that T1 is the time when spores become committed to germinate; (v) elevated levels of SpoVA proteins involved in DPA movement in spore germination decreased T1 and Tlag times but not the amount of DPA released in ΔTleakage; (vi) lack of the cortex-lytic enzyme CwlJ increased DPA leakage during germination due to longer ΔTleakage times in which more DPA was released; and (vii) there was slow DPA leakage early in germination of B. subtilis spores by the nonnutrients CaDPA and dodecylamine and in nutrient germination of Bacillus cereus and Bacillus megaterium spores. Overall, these findings have identified and characterized a new early event in Bacillus spore germination. PMID:25583976

  18. Protection of Bacillus pumilus spores by catalases.

    PubMed

    Checinska, Aleksandra; Burbank, Malcolm; Paszczynski, Andrzej J

    2012-09-01

    Bacillus pumilus SAFR-032, isolated at spacecraft assembly facilities of the National Aeronautics and Space Administration Jet Propulsion Laboratory, is difficult to kill by the sterilization method of choice, which uses liquid or vapor hydrogen peroxide. We identified two manganese catalases, YjqC and BPUM_1305, in spore protein extracts of several B. pumilus strains by using PAGE and mass spectrometric analyses. While the BPUM_1305 catalase was present in six of the B. pumilus strains tested, YjqC was not detected in ATCC 7061 and BG-B79. Furthermore, both catalases were localized in the spore coat layer along with laccase and superoxide dismutase. Although the initial catalase activity in ATCC 7061 spores was higher, it was less stable over time than the SAFR-032 enzyme. We propose that synergistic activity of YjqC and BPUM_1305, along with other coat oxidoreductases, contributes to the enhanced resistance of B. pumilus spores to hydrogen peroxide. We observed that the product of the catalase reaction, gaseous oxygen, forms expanding vesicles on the spore surface, affecting the mechanical integrity of the coat layer, resulting in aggregation of the spores. The accumulation of oxygen gas and aggregations may play a crucial role in limiting further exposure of Bacilli spore surfaces to hydrogen peroxide or other toxic chemicals when water is present. PMID:22752169

  19. Protein profile of Bacillus subtilis spore.

    PubMed

    Mao, Langyong; Jiang, Shantong; Wang, Bin; Chen, Liang; Yao, Qin; Chen, Keping

    2011-08-01

    Natural wild-type strains of Bacillus subtilis spore is regarded as a non-pathogenic for both human and animal, and has been classified as a novel food which is currently being used as probiotics added in the consumption. To identify B. subtilis spore proteins, we have accomplished a preliminary proteomic analysis of B. subtilis spore, with a combination of two-dimensional electrophoretic separations and matrix-assisted laser desorption ionization tandem time of flight mass spectrometry (MALDI-TOF-MS). In this article, we presented a reference map of 158 B. subtilis spore proteins with an isoelectric point (pI) between 4 and 7. Followed by mass spectrometry (MS) analysis, we identified 71 B. subtilis spore proteins with high level of confidence. Database searches, combined with hydropathy analysis and GO analysis revealed that most of the B. subtilis spore proteins were hydrophilic proteins related to catalytic function. These results should accelerate efforts to understand the resistance of spore to harsh conditions. PMID:21667307

  20. Memory of Germinant Stimuli in Bacterial Spores

    PubMed Central

    Wang, Shiwei; Faeder, James R.; Setlow, Peter

    2015-01-01

    ABSTRACT Bacterial spores, despite being metabolically dormant, possess the remarkable capacity to detect nutrients and other molecules in their environment through a biochemical sensory apparatus that can trigger spore germination, allowing the return to vegetative growth within minutes of exposure of germinants. We demonstrate here that bacterial spores of multiple species retain memory of transient exposures to germinant stimuli that can result in altered responses to subsequent exposure. The magnitude and decay of these memory effects depend on the pulse duration as well as on the separation time, incubation temperature, and pH values between the pulses. Spores of Bacillus species germinate in response to nutrients that interact with germinant receptors (GRs) in the spore’s inner membrane, with different nutrient types acting on different receptors. In our experiments, B. subtilis spores display memory when the first and second germinant pulses target different receptors, suggesting that some components of spore memory are downstream of GRs. Furthermore, nonnutrient germinants, which do not require GRs, exhibit memory either alone or in combination with nutrient germinants, and memory of nonnutrient stimulation is found to be more persistent than that induced by GR-dependent stimuli. Spores of B. cereus and Clostridium difficile also exhibit germination memory, suggesting that memory may be a general property of bacterial spores. These observations along with experiments involving strains with mutations in various germination proteins suggest a model in which memory is stored primarily in the metastable states of SpoVA proteins, which comprise a channel for release of dipicolinic acid, a major early event in spore germination. PMID:26604257

  1. Dustborne Alternaria alternata antigens in U.S. homes: Results from the National Survey of Lead and Allergens in Housing

    PubMed Central

    Salo, Päivi M.; Yin, Ming; Arbes, Samuel J.; Cohn, Richard D.; Sever, Michelle; Muilenberg, Michael; Burge, Harriet A.; London, Stephanie J.; Zeldin, Darryl C.

    2005-01-01

    Background: Alternaria alternata is one of the most common fungi associated with allergic disease. However, Alternaria exposure in indoor environments is not well characterized. Objective: The primary goals of this study were to examine the prevalence of Alternaria exposure and identify independent predictors of Alternaria antigen concentrations in U.S. homes. Methods: Data for this cross-sectional study were obtained from the National Survey of Lead and Allergens in Housing. A nationally representative sample of 831 housing units in 75 different locations throughout the U.S. completed the survey. Information on housing and household characteristics was obtained by questionnaire and environmental assessments. Concentrations of Alternaria antigens in dust collected from various indoor sites were assessed with a polyclonal anti-Alternaria antibody assay. Results: Alternaria antigens were detected in most (95-99%) of the dust samples. The geometric mean concentration, reflecting the average Alternaria concentration in homes, was 4.88 μg/g (SE=0.13 μg/g). In the multivariable linear regression analysis, the age of the housing unit, geographic region, urbanization, poverty, family race, observed mold and moisture problems, use of dehumidifier, and presence of cats and dogs were independent predictors of Alternaria antigen concentrations. Less frequent cleaning and smoking indoors also contributed to higher Alternaria antigen levels in homes. Conclusion: Exposure to Alternaria alternata antigens in U.S. homes is common. Antigen levels in homes are not only influenced by regional factors but also by residential characteristics. Preventing mold and moisture problems, avoiding smoking indoors, and regular household cleaning may help reduce exposure to Alternaria antigens indoors. PMID:16159634

  2. Micro-sonicator for spore lysis

    DOEpatents

    Miles, Robin R.; Belgrader, Phillip; Nasarabadi, Shanavaz L.

    2000-01-01

    A micro-sonicator for spore lysis. Using micromachining technology, the micro-sonicator uses ultrasonic excitation of spores to perform spore and cell lysis. The micro-sonicator comprises a container with a cavity therein for retaining the sample in an ultrasonic transmission medium, the cavity being closed by a silicon membrane to which an electrode and piezoelectric material are attached, with the electrode and piezoelectric material being electrically connected to an AC signal generator which causes the membrane to flex and vibrate at the frequency of the applied voltage.

  3. Isotope fractionation of selenium during fungal biomethylation by Alternaria alternata.

    PubMed

    Schilling, Kathrin; Johnson, Thomas M; Wilcke, Wolfgang

    2011-04-01

    The natural abundance of stable Se isotopes may reflect sources and formation conditions of methylated Se. We aimed at (1) quantifying the degree of methylation of selenate [Se(VI)] and (hydro)selenite [Se(IV)] by the fungus Alternaria alternata at pH 4 and 7 and (2) determining the effects of these different Se sources and pH values on 82Se/76Se ratios (δ82/76Se) in methylselenides. Alternaria alternata was incubated with Se(VI) and Se(IV) in closed microcosms for 11-15 days and additionally with Se(IV) for 3-5 days at 30 °C. We determined Se concentrations and δ82/76Se values in source Se(VI) and Se(IV), media, fungi, and trapped methylselenides. In Se(VI) incubations, methylselenide volatilization ended before the 11th day, and the amounts of trapped methylselenide were not significantly different among the 11-15 day incubations. In 11-15 days, 2.9-11% of Se(VI) and 21-29% of Se(IV) were methylated, and in 3-5 days, 3-5% of Se(IV) was methylated. The initial δ82/76Se values of Se(VI) and Se(IV) were -0.69±SD 0.07‰, and -0.20±0.05‰, respectively. The δ82/76Se values of methylselenides differed significantly between Se(VI) (-3.97‰ to -3.25‰) and Se(IV) (-1.44‰ to -0.16‰) as sources after 11-15 days of incubation; pH had little influence on δ82/76Se values. Thus, the δ82/76Se values of methylselenide indicate the source species of methylselenides used in this study. The strong isotope fractionation of Se(VI) is probably attributable to the different reduction steps of Se(VI) to Se(-II) which were rate-limiting explaining the low methylation yields, but not to the methylation itself. The shorter incubation of Se(IV) for 3-5 days showed a large Se isotope fractionation of at least -6‰ before the biomethylation reaction reached its end. This initial Se isotope fractionation during methylation of Se(IV) is much larger than previously published. PMID:21366259

  4. Hyperspectral and Thermal Imaging of Oilseed Rape (Brassica napus) Response to Fungal Species of the Genus Alternaria

    PubMed Central

    Baranowski, Piotr; Jedryczka, Malgorzata; Mazurek, Wojciech; Babula-Skowronska, Danuta; Siedliska, Anna; Kaczmarek, Joanna

    2015-01-01

    In this paper, thermal (8-13 µm) and hyperspectral imaging in visible and near infrared (VNIR) and short wavelength infrared (SWIR) ranges were used to elaborate a method of early detection of biotic stresses caused by fungal species belonging to the genus Alternaria that were host (Alternaria alternata, Alternaria brassicae, and Alternaria brassicicola) and non-host (Alternaria dauci) pathogens to oilseed rape (Brassica napus L.). The measurements of disease severity for chosen dates after inoculation were compared to temperature distributions on infected leaves and to averaged reflectance characteristics. Statistical analysis revealed that leaf temperature distributions on particular days after inoculation and respective spectral characteristics, especially in the SWIR range (1000-2500 nm), significantly differed for the leaves inoculated with A. dauci from the other species of Alternaria as well as from leaves of non-treated plants. The significant differences in leaf temperature of the studied Alternaria species were observed in various stages of infection development. The classification experiments were performed on the hyperspectral data of the leaf surfaces to distinguish days after inoculation and Alternaria species. The second-derivative transformation of the spectral data together with back-propagation neural networks (BNNs) appeared to be the best combination for classification of days after inoculation (prediction accuracy 90.5%) and Alternaria species (prediction accuracy 80.5%). PMID:25826369

  5. Indoor and outdoor atmospheric fungal spores in the São Paulo metropolitan area (Brazil): species and numeric concentrations

    NASA Astrophysics Data System (ADS)

    Gonçalves, Fábio Luiz Teixeira; Bauer, Heidi; Cardoso, Maria Regina Alves; Pukinskas, Sandra; Matos, Dulcilena; Melhem, Márcia; Puxbaum, Hans

    2010-07-01

    The aim of this study was to estimate the indoor and outdoor concentrations of fungal spores in the Metropolitan Area of Sao Paulo (MASP), collected at different sites in winter/spring and summer seasons. The techniques adopted included cultivation (samples collected with impactors) and microscopic enumeration (samples collected with impingers). The overall results showed total concentrations of fungal spores as high as 36,000 per cubic meter, with a large proportion of non culturable spores (around 91% of the total). Penicillium sp. and Aspergillus sp. were the dominant species both indoors and outdoors, in all seasons tested, occurring in more than 30% of homes at very high concentrations of culturable airborne fungi [colony forming units(CFU) m-3]. There was no significant difference between indoor and outdoor concentrations. The total fungal spore concentration found in winter was 19% higher than that in summer. Heat and humidity were the main factors affecting fungal growth; however, a non-linear response to these factors was found. Thus, temperatures below 16°C and above 25°C caused a reduction in the concentration (CFU m-3) of airborne fungi, which fits with MASP climatalogy. The same pattern was observed for humidity, although not as clearly as with temperature given the usual high relative humidity (above 70%) in the study area. These results are relevant for public health interventions that aim to reduce respiratory morbidity among susceptible populations.

  6. Quantification and Single-Spore Detection of Phakopsora pachyrhizi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The microscopic identification and quantification of Phakopsora pachyrhizi spores from environmental samples, spore traps, and laboratory specimens can represent a challenge. Such reports, especially from passive spore traps, commonly describe the number of “rust-like” spores; for other forensic sa...

  7. Identification, characterization and mycotoxigenic ability of Alternaria spp. causing core rot of apple fruit in Greece.

    PubMed

    Ntasiou, Panagiota; Myresiotis, Charalampos; Konstantinou, Sotiris; Papadopoulou-Mourkidou, Euphemia; Karaoglanidis, George S

    2015-03-16

    Alternaria core rot is a major postharvest disease of apple fruit in several countries of the world, including Greece. The study was conducted aiming to identify the disease causal agents at species level, investigate the aggressiveness of Alternaria spp. isolates and the susceptibility of different apple varieties and determine the mycotoxigenic potential of Alternaria spp. isolates from apple fruit. Seventy-five Alternaria spp. isolates obtained from apple fruit showing core rot symptoms were identified as either Alternaria tenuissima or Alternaria arborescens at frequencies of 89.3 and 11.7%, respectively, based on the sequence of endopolygalacturonase (EndoPG) gene. Artificial inoculations of fruit of 4 different varieties (Fuji, Golden Delicious, Granny Smith and Red Delicious) and incubation at two different temperatures (2 and 25°C) showed that fruit of Fuji variety were the most susceptible and fruit of Golden Delicious the most resistant to both pathogens. In addition, the production of 3 mycotoxins, alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) was investigated in 30 isolates of both species. Mycotoxin determination was conducted both in vitro, on artificial nutrient medium and in vivo on artificially inoculated apple fruit, using a high performance liquid chromatography with diode array detector (HPLC-DAD). The results showed that most of the isolates of both species were able to produce all the 3 metabolites both in vivo and in vitro. On apple fruit A. tenuissima isolates produced more AOH than A. arborescens isolates, whereas the latter produced more TEN than the former. Such results indicate that Alternaria core rot represents a major threat of apple fruit production not only due to quantitative yield losses but also for qualitative deterioration of apple by-products. PMID:25560914

  8. Quantifying Airborne Allergen Levels Before and After Rain Events Using TRMM/GPM and Ground-Sampled Data

    NASA Technical Reports Server (NTRS)

    Stewart, Randy M.

    2006-01-01

    Allergies affect millions of Americans, increasing health risks and also increasing absenteeism and reducing productivity in the workplace. Outdoor allergens, such as airborne pollens and mold spores, commonly trigger respiratory distress symptoms, but rainfall reduces the quantity of allergens in the air (EPA, 2003). The current NASA Tropical Rainfall Measuring Mission provides accurate information related to rain events. These capabilities will be further enhanced with the future Global Precipitation Measurement mission. This report examines the effectiveness of combining these NASA resources with established ground-based allergen/spore sampling systems to better understand the benefits that rain provides in removing allergens and spores from the air.

  9. Alternaria infections: laboratory diagnosis and relevant clinical features.

    PubMed

    Pastor, F J; Guarro, J

    2008-08-01

    The genus Alternaria contains several species of melanized hyphomycetes that cause opportunistic human infections. The published literature contains 210 reported cases of human alternarioses between 1933 and the present day. The most frequent clinical manifestations are cutaneous and subcutaneous infections (74.3%), followed by oculomycosis (9.5%), invasive and non-invasive rhinosinusitis (8.1%) and onychomycosis (8.1%). Immunosuppression is frequently associated with cutaneous and subcutaneous infections and rhinosinusitis. The most important risk factors for cutaneous and subcutaneous infections are solid organ transplantation and Cushing's syndrome, and those for rhinosinusitis are bone marrow transplants. Having been exposed to soil and garbage is common in all cases of oculomycosis, with corticotherapy being a risk factor in 50% of these cases. Previous contact with soil and/or trauma to the nails is associated with most cases of onychomycosis. In general, alternariosis shows a good response to conventional antifungal drugs. On some occasions, steroid suppression or reduction is sufficient to resolve an infection. Itraconazole is the antifungal drug used most frequently to successfully treat onychomycosis and cutaneous and subcutaneous infections. Posaconazole and voriconazole are promising therapeutic options, with the latter being especially so for oculomycosis. PMID:18727797

  10. Evaluation of Alternaria mycotoxins in strawberries: quantification and storage condition.

    PubMed

    Juan, Cristina; Oueslati, Souheib; Mañes, Jordi

    2016-05-01

    Alternariol (AOH), alternariol methyl ether (AME) and tentoxin (TEN) are Alternaria mycotoxins produced by the most common post-harvest pathogens of fruits. The production of these metabolites depends on several environmental factors, mainly temperature, water activity, pH and the technological treatments that have been applied to the product. In this study, the occurrence of AOH, AME and TEN was evaluated in strawberries samples stored at different temperatures ranges (at 22 ± 2 or 6 ± 2°C) and different periods (up to 1 month) simulating the current practice of consumer's storage conditions. Sample extraction was performed using a liquid-liquid extraction method prior to LC-MS/MS analysis. AOH was the most prevalent mycotoxins with a 42% at strawberries stored at (22 ± 2)°C and 37% stored at (6 ± 2)°C. The highest AOH levels were found in samples conserved at (22 ± 2)°C ranging between 26 and 752 ng g(-1). AME levels ranged between 11 and 137 ng g(-)(1), which were found mainly in stored samples at (6 ± 2)°C for more than 28 days. None sample presented levels of TEN in either of the studied conditions. PMID:27103180

  11. Asynchronous spore germination in isogenic natural isolates of Saccharomyces paradoxus.

    PubMed

    Stelkens, Rike B; Miller, Eric L; Greig, Duncan

    2016-05-01

    Spores from wild yeast isolates often show great variation in the size of colonies they produce, for largely unknown reasons. Here we measure the colonies produced from single spores from six different wild Saccharomyces paradoxus strains. We found remarkable variation in spore colony sizes, even among spores that were genetically identical. Different strains had different amounts of variation in spore colony sizes, and variation was not affected by the number of preceding meioses, or by spore maturation time. We used time-lapse photography to show that wild strains also have high variation in spore germination timing, providing a likely mechanism for the variation in spore colony sizes. When some spores from a laboratory strain make small colonies, or no colonies, it usually indicates a genetic or meiotic fault. Here, we demonstrate that in wild strains spore colony size variation is normal. We discuss and assess potential adaptive and non-adaptive explanations for this variation. PMID:26880797

  12. Rapid onsite assessment of spore viability.

    SciTech Connect

    Branda, Steven; Lane, Todd W.; VanderNoot, Victoria A.; Gaucher, Sara P.; Jokerst, Amanda S.

    2005-12-01

    This one year LDRD addresses problems of threat assessment and restoration of facilities following a bioterror incident like the incident that closed down mail facilities in late 2001. Facilities that are contaminated with pathogenic spores such as B. anthracis spores must be shut down while they are treated with a sporicidal agent and the effectiveness of the treatment is ascertained. This process involves measuring the viability of spore test strips, laid out in a grid throughout the facility; the CDC accepted methodologies require transporting the samples to a laboratory and carrying out a 48 hr outgrowth experiment. We proposed developing a technique that will ultimately lead to a fieldable microfluidic device that can rapidly assess (ideally less than 30 min) spore viability and effectiveness of sporicidal treatment, returning facilities to use in hours not days. The proposed method will determine viability of spores by detecting early protein synthesis after chemical germination. During this year, we established the feasibility of this approach and gathered preliminary results that should fuel a future more comprehensive effort. Such a proposal is currently under review with the NIH. Proteomic signatures of Bacillus spores and vegetative cells were assessed by both slab gel electrophoresis as well as microchip based gel electrophoresis employing sensitive laser-induced fluorescence detection. The conditions for germination using a number of chemical germinants were evaluated and optimized and the time course of protein synthesis was ascertained. Microseparations were carried out using both viable spores and spores inactivated by two different methods. A select number of the early synthesis proteins were digested into peptides for analysis by mass spectrometry.

  13. Genetic variability of Brazilian isolates of Alternaria alternata detected by AFLP and RAPD techniques

    PubMed Central

    Dini-Andreote, Francisco; Pietrobon, Vivian Cristina; Andreote, Fernando Dini; Romão, Aline Silva; Spósito, Marcel Bellato; Araújo, Welington Luiz

    2009-01-01

    The Alternaria brown spot (ABS) is a disease caused in tangerine plants and its hybrids by the fungus Alternaria alternata f. sp. citri which has been found in Brazil since 2001. Due to the recent occurrence in Brazilian orchards, the epidemiology and genetic variability of this pathogen is still an issue to be addressed. Here it is presented a survey about the genetic variability of this fungus by the characterization of twenty four pathogenic isolates of A. alternata f. sp. citri from citrus plants and four endophytic isolates from mango (one Alternaria tenuissima and three Alternaria arborescens). The application of two molecular markers Random Amplified Polymorphic DNA (RAPD) and Amplified Fragment Length Polymorphism (AFLP) had revealed the isolates clustering in distinct groups when fingerprintings were analyzed by Principal Components Analysis (PCA). Despite the better assessment of the genetic variability through the AFLP, significant modifications in clusters components were not observed, and only slight shifts in the positioning of isolates LRS 39/3 and 25M were observed in PCA plots. Furthermore, in both analyses, only the isolates from lemon plants revealed to be clustered, differently from the absence of clustering for other hosts or plant tissues. Summarizing, both RAPD and AFLP analyses were both efficient to detect the genetic variability within the population of the pathogenic fungus Alternaria spp., supplying information on the genetic variability of this species as a basis for further studies aiming the disease control. PMID:24031413

  14. Isolation and characterization of the grain mold fungi, Cochliobolus and Alternaria spp., from sorghum using semi-selective media and DNA sequence analyses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 m...

  15. Sensitive, Rapid Detection of Bacterial Spores

    NASA Technical Reports Server (NTRS)

    Kern, Roger G.; Venkateswaran, Kasthuri; Chen, Fei; Pickett, Molly; Matsuyama, Asahi

    2009-01-01

    A method of sensitive detection of bacterial spores within delays of no more than a few hours has been developed to provide an alternative to a prior three-day NASA standard culture-based assay. A capability for relatively rapid detection of bacterial spores would be beneficial for many endeavors, a few examples being agriculture, medicine, public health, defense against biowarfare, water supply, sanitation, hygiene, and the food-packaging and medical-equipment industries. The method involves the use of a commercial rapid microbial detection system (RMDS) that utilizes a combination of membrane filtration, adenosine triphosphate (ATP) bioluminescence chemistry, and analysis of luminescence images detected by a charge-coupled-device camera. This RMDS has been demonstrated to be highly sensitive in enumerating microbes (it can detect as little as one colony-forming unit per sample) and has been found to yield data in excellent correlation with those of culture-based methods. What makes the present method necessary is that the specific RMDS and the original protocols for its use are not designed for discriminating between bacterial spores and other microbes. In this method, a heat-shock procedure is added prior to an incubation procedure that is specified in the original RMDS protocols. In this heat-shock procedure (which was also described in a prior NASA Tech Briefs article on enumerating sporeforming bacteria), a sample is exposed to a temperature of 80 C for 15 minutes. Spores can survive the heat shock, but nonspore- forming bacteria and spore-forming bacteria that are not in spore form cannot survive. Therefore, any colonies that grow during incubation after the heat shock are deemed to have originated as spores.

  16. CmWRKY15 Facilitates Alternaria tenuissima Infection of Chrysanthemum.

    PubMed

    Fan, Qingqing; Song, Aiping; Xin, Jingjing; Chen, Sumei; Jiang, Jiafu; Wang, Yinjie; Li, Xiran; Chen, Fadi

    2015-01-01

    Abscisic acid (ABA) has an important role in the responses of plants to pathogens due to its ability to induce stomatal closure and interact with salicylic acid (SA) and jasmonic acid (JA). WRKY transcription factors serve as antagonistic or synergistic regulators in the response of plants to a variety of pathogens. Here, we demonstrated that CmWRKY15, a group IIa WRKY family member, was not transcriptionally activated in yeast cells. Subcellular localization experiments in which onion epidermal cells were transiently transfected with CmWRKY15 indicated that CmWRKY15 localized to the nucleus in vivo. The expression of CmWRKY15 could be markedly induced by the presence of Alternaria tenuissima inoculum in chrysanthemum. Furthermore, the disease severity index (DSI) data of CmWRKY15-overexpressing plants indicated that CmWRKY15 overexpression enhanced the susceptibility of chrysanthemum to A. tenuissima infection compared to controls. To illustrate the mechanisms by which CmWRKY15 regulates the response to A. tenuissima inoculation, the expression levels of ABA-responsive and ABA signaling genes, such as ABF4, ABI4, ABI5, MYB2, RAB18, DREB1A, DREB2A, PYL2, PP2C, RCAR1, SnRK2.2, SnRK2.3, NCED3A, NCED3B, GTG1, AKT1, AKT2, KAT1, KAT2, and KC1were compared between transgenic plants and controls. In summary, our data suggest that CmWRKY15 might facilitate A. tenuissima infection by antagonistically regulating the expression of ABA-responsive genes and genes involved in ABA signaling, either directly or indirectly. PMID:26600125

  17. CmWRKY15 Facilitates Alternaria tenuissima Infection of Chrysanthemum

    PubMed Central

    Fan, Qingqing; Song, Aiping; Xin, Jingjing; Chen, Sumei; Jiang, Jiafu; Wang, Yinjie; Li, Xiran; Chen, Fadi

    2015-01-01

    Abscisic acid (ABA) has an important role in the responses of plants to pathogens due to its ability to induce stomatal closure and interact with salicylic acid (SA) and jasmonic acid (JA). WRKY transcription factors serve as antagonistic or synergistic regulators in the response of plants to a variety of pathogens. Here, we demonstrated that CmWRKY15, a group IIa WRKY family member, was not transcriptionally activated in yeast cells. Subcellular localization experiments in which onion epidermal cells were transiently transfected with CmWRKY15 indicated that CmWRKY15 localized to the nucleus in vivo. The expression of CmWRKY15 could be markedly induced by the presence of Alternaria tenuissima inoculum in chrysanthemum. Furthermore, the disease severity index (DSI) data of CmWRKY15-overexpressing plants indicated that CmWRKY15 overexpression enhanced the susceptibility of chrysanthemum to A. tenuissima infection compared to controls. To illustrate the mechanisms by which CmWRKY15 regulates the response to A. tenuissima inoculation, the expression levels of ABA-responsive and ABA signaling genes, such as ABF4, ABI4, ABI5, MYB2, RAB18, DREB1A, DREB2A, PYL2, PP2C, RCAR1, SnRK2.2, SnRK2.3, NCED3A, NCED3B, GTG1, AKT1, AKT2, KAT1, KAT2, and KC1were compared between transgenic plants and controls. In summary, our data suggest that CmWRKY15 might facilitate A. tenuissima infection by antagonistically regulating the expression of ABA-responsive genes and genes involved in ABA signaling, either directly or indirectly. PMID:26600125

  18. The use of an experimental room for monitoring of airborne concentrations of microorganisms, glass fibers, and total particles

    SciTech Connect

    Buttner, M.P.; Stetzenbach, L.D.

    1996-12-31

    An experimental room was used as a microcosm for studies of airborne particles and microorganisms in indoor environments. The interior of the room measures 4 by 4 by 2.2 m high and has a hardwood floor and the walls and ceiling are sheetrocked and coated with interior latex paint. Exterior walls are 11.4-cm thick plywood panels consisting of two outer sections of plywood insulated with fiber glass batts. The ceiling is of similar construction with 17.1-cm thick panels. Attached to the room entrance is an anteroom equipped with a HEPA-filtered air shower to reduce mixing of air resulting from entering and exiting during experiments. The room is equipped with a computer-controlled heating, ventilation, and cooling system. Temperature, relative humidity, air flow, and room pressure can be continuously monitored by probes located in the room and air handling system components. Several research projects have been conducted using this room including monitoring the potential for airborne glass fibers released from rigid fibrous ductboard, comparisons of commercially available samplers for monitoring of airborne fungal spores, and a study on the efficacy of vacuum bags to minimize dispersal of particles, including fungal spores from fungal-contaminated carpet. During studies designed to monitor airborne fiberglass, air samples were taken in the room serviced by new rigid fibrous glass ductwork, and the results were compared to those obtained in the room with bare metal ductwork installed. Monitoring of airborne fungal spores using the Andersen six-stage sampler, the high flow Spiral Biotech sampler, the Biotest RCS Plus sampler, and the Burkard spore trap sampler was performed following the release of Penicillium spores into the room through the supply register. Dispersal of carpet-associated particles and fungal spores was measured after vacuuming using conventional cellulose vacuum bags in comparison to recently developed bags.

  19. Examination of fungi in domestic interiors by using factor analysis: Correlations and associations with home factors. [Cladosporium, Alternaria, Epicoccum, Aureobasidium, Aspergillus; Penicillium

    SciTech Connect

    Su, H.J.; Rotnitzky, A.; Spengler, J.D. ); Burge, H.A. )

    1992-01-01

    Factor analysis was utilized to investigate correlations among airborne microorganisms collected with Andersen samplers from homes in Topeka, Kans., during the winter of 1987 to 1988. The factors derived were used to relate microbial concentrations with categorical, questionnaire-derived descriptions of housing conditions. This approach successfully identified groups of common aboveground decay fungi including Cladosporium, Alternaria, Epicoccum, and Aureobasidium spp. The common soil fungi Aspergillus and Penicillium spp. were also separated as a group. These previously known ecological groupings were confirmed with air sampling data by a quantitative evaluation technique. The above ground decay fungi sampled indoors in winter were present at relatively high concentrations in homes with gas stoves for cooking, suggesting a possible association between these fungi and increased humidity from the combustion process. Elevated concentrations of the soil fungi were significantly associated with the dirt floor, crawl-space type of basement. Elevated concentrations of water-requiring fungi, such as Fusarium spp., were shown to be associated with water collection in domestic interiors. Also, elevated mean concentrations for the group of fungi including Cladosporium, Epicoccum, Aureobasidium, and yeast spp. were found to be associated with symptoms reported on a health questionnaire. This finding was consistent with the authors previous study of associations between respiratory health and airborne microorganisms by univariate logistic regression analysis.

  20. Personal exposure to airborne dust and microorganisms in agricultural environments.

    PubMed

    Lee, Shu-An; Adhikari, Atin; Grinshpun, Sergey A; McKay, Roy; Shukla, Rakesh; Reponen, Tiina

    2006-03-01

    Airborne dust and microorganisms are associated with respiratory diseases and increased mortality and morbidity. Farmers are at high risk of exposure to both of these hazards. Very limited information, however, is available on the combined exposures to both hazards on different types of farms. Moreover, most of the previous studies have measured the mass concentration of particles ignoring the particle size. In this study, farmers' exposure to airborne dust and microorganisms was studied using our newly developed personal sampling system. Particle number concentration and size distribution were measured with an optical particle counter. Simultaneously, particles were collected on a filter and analyzed for microorganisms. The field measurements were conducted in animal confinements (swine, poultry, and dairy) and during grain harvesting (corn and soybean). The results show the following average concentrations on the workers' breathing zone: 1.7 x 10(6) to 2.9 x 10(7) particles/m(3) for total dust, 0.9 x 10(3) to 3.9 x 10(4) spores/m(3) for total fungal spores, 0.3 x 10(3) to 3.6 x 10(4)CFU/m(3) for culturable fungal spores, 0.3 x 10(4) to 3.3 x 10(8) CFU/m(3) for culturable bacteria, and limit of detection (LOD) to 2.8 x 10(3) CFU/m(3) for culturable actinomycetes in animal confinements. The respective concentrations were 4.4 x 10(6) to 5.8 x 10(7) particles/m(3), 3.4 x 10(4) to 6.1 x 10(6) spores/m(3), 8.2 x 10(4) to 7.4 x 10(6) CFU/m(3), 0.4 x 10(5) to 1.4 x 10(6) CFU/m(3), and LOD to 2.6 x 10(4) CFU/m(3) during grain harvesting. The highest contribution of large particles (3-10 microm) in total particles was found during grain harvesting, whereas the size distribution was dominated by smaller particles (< 3 microm) in animal confinements. High fraction (up to 37%) of particles between 2-10 microm was found to be fungal spores. The results indicate that an increase in the concentration of large dust particles (2-10 microm) during grain harvesting was partially

  1. Aerodynamics of puffball mushroom spore dispersal

    NASA Astrophysics Data System (ADS)

    Amador, Guillermo; Barberie, Alex; Hu, David

    2012-11-01

    Puffball mushrooms Lycoperdon are spherical fungi that release a cloud of spores in response to raindrop impacts. In this combined experimental and theoretical study, we elucidate the aerodynamics of this unique impact-based spore-dispersal. We characterize live puffball ejections by high speed video, the geometry and elasticity of their shells by cantilever experiments, and the packing fraction and size of their spores by scanning electron microscope. We build a dynamically similar puffball mimic composed of a tied-off latex balloon filled with baby powder and topped with a 1-cm slit. A jet of powder is elicited by steady lateral compression of the mimic between two plates. The jet height is a bell-shaped function of force applied, with a peak of 18 cm at loads of 45 N. We rationalize the increase in jet height with force using Darcy's Law: the applied force generates an overpressure maintained by the air-tight elastic membrane. Pressure is relieved as the air travels through the spore interstitial spaces, entrains spores, and exits through the puffball orifice. This mechanism demonstrates how powder-filled elastic shells can generate high-speed jets using energy harvested from rain.

  2. Bacillus subtilis Spore Inner Membrane Proteome.

    PubMed

    Zheng, Linli; Abhyankar, Wishwas; Ouwerling, Natasja; Dekker, Henk L; van Veen, Henk; van der Wel, Nicole N; Roseboom, Winfried; de Koning, Leo J; Brul, Stanley; de Koster, Chris G

    2016-02-01

    The endospore is the dormant form of Bacillus subtilis and many other Firmicutes. By sporulation, these spore formers can survive very harsh physical and chemical conditions. Yet, they need to go through germination to return to their growing form. The spore inner membrane (IM) has been shown to play an essential role in triggering the initiation of germination. In this study, we isolated the IM of bacterial spores, in parallel with the isolation of the membrane of vegetative cells. With the use of GeLC-MS/MS, over 900 proteins were identified from the B. subtilis spore IM preparations. By bioinformatics-based membrane protein predictions, ca. one-third could be predicted to be membrane-localized. A large number of unique proteins as well as proteins common to the two membrane proteomes were identified. In addition to previously known IM proteins, a number of IM proteins were newly identified, at least some of which are likely to provide new insights into IM physiology, unveiling proteins putatively involved in spore germination machinery and hence putative germination inhibition targets. PMID:26731423

  3. Method for collecting spores from a mold

    DOEpatents

    Au, Frederick H. F.; Beckert, Werner F.

    1977-01-01

    A technique and apparatus used therewith for determining the uptake of plutonium and other contaminants by soil microorganisms which, in turn, gives a measure of the plutonium and/or other contaminants available to the biosphere at that particular time. A measured quantity of uncontaminated spores of a selected mold is added to a moistened sample of the soil to be tested. The mixture is allowed to sit a predetermined number of days under specified temperature conditions. An agar layer is then applied to the top of the sample. After three or more days, when spores of the mold growing in the sample have formed, the spores are collected by a miniature vacuum collection apparatus operated under preselected vacuum conditions, which collect only the spores with essentially no contamination by mycelial fragments or culture medium. After collection, the fungal spores are dried and analyzed for the plutonium and/or other contaminants. The apparatus is also suitable for collection of pollen, small insects, dust and other small particles, material from thin-layer chromatography plates, etc.

  4. Novel Species of Non-Spore-Forming Bacteria

    NASA Technical Reports Server (NTRS)

    Briegel, Ariane; Osman, Shariff; Moissl, Christine; Hosoya,Naofumi; Venkateswaran, Kasthuri; Satomi, Masataka; Mayilraj, Shanmugam

    2008-01-01

    While cataloging cultivatable microbes from the airborne biological diversity of the atmosphere of the Regenerative Enclosed life-support Module Simulator (REMS) system at Marshall Space Flight Center, two strains that belong to one novel bacterial species were isolated. Based on 16S rRNA gene sequencing and the unique morphology and the taxonomic characteristics of these strains, it is shown that they belong to the family Intrasporangiaceae, related to the genus Tetrasphaera, with phylogenetic distances from any validly described species of the genus Tetrasphaera ranging from 96.71 to 97.76 percent. The fatty acid profile supported the affiliation of these novel strains to the genus Tetrasphaera except for the presence of higher concentrations of octadecenoic acid (C18:0) and cis-9-octadecenoic acid (C18:1), which discriminates these strains from other valid species. In addition, DNA-DNA hybridization studies indicate that these strains belong to a novel species that could be readily distinguished from its nearest neighbor, Tetrasphaera japonica AMC 5116T, with less than 20 percent DNA relatedness. Physiological and biochemical tests show few phenotypic dissimilarities, but genotypic analysis allowed the differentiation of these gelatin-liquefying strains from previously reported strains. The name Tetrasphaera remsis sp. Nov. is proposed with the type strain 3-M5-R-4(sup T) (=ATCC BAA-1496(sup T)=CIP 109413(sup T). The cells are Gram-positive, nonmotile, cocci, in tetrad arrangement and clusters. Spore formation is not observed. No species of Tetrashpaera has ever been isolated from airborne samples. Previous discoveries have come from soil and activated sludge samples. As other species of this genus have demonstrated enhanced biological phosphorus removal activity, further tests are required to determine if this newly discovered species would have bioremediation applications.

  5. Alternaria toxins in wheat from the Autonomous Province of Vojvodina, Serbia: a preliminary survey.

    PubMed

    Janić Hajnal, Elizabet; Orčić, Dejan; Torbica, Aleksandra; Kos, Jovana; Mastilović, Jasna; Škrinjar, Marija

    2015-01-01

    Although Fusarium species remain a main source of mycotoxin contamination of wheat, in recent years, due to the evident climatic changes, other mycotoxigenic fungi have been recognised as important wheat contaminants. Alternaria species, especially A. alternata, have been found as contaminants of wheat as well as wheat-based products. Under favourable conditions A. alternata very often produce alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA) and others Alternaria toxins. The aim of the present study was to examine the presence of three Alternaria toxins (AOH, AME and TeA) in wheat samples harvested during three years (2011-13). To this end, 92 samples were collected during wheat harvesting from different growing regions of the Autonomous Province of Vojvodina, which represents the most important wheat-growing area in Serbia. The presence of Alternaria toxins was analysed by HPLC with electrospray ionisation triple quadrupole mass spectrometry (LC-ESI-MS/MS). Among all the analysed wheat samples, 63 (68.5%) were contaminated with TeA, 11 (12.0%) with AOH and 6 (6.5%) with AME. Furthermore, the maximum and mean toxin concentrations were 2676 and 92.4 µg kg(-1), 48.9 and 18.6 µg kg(-1), and 70.2 and 39.0 µg kg(-1) for TeA, AOH and AME, respectively. Co-occurrence of three Alternaria toxins in wheat samples was detected in six samples; a combination of two toxins was found in two samples; and 64 samples contained one toxin. The results showed that among 92 analysed wheat samples, only 20 (21.7%) samples were without Alternaria toxins. The presence of Alternaria toxins was also investigated in terms of weather conditions recorded during the period of investigation, as well as with the sampling region. This study represents the first preliminary report of the natural occurrence of Alternaria toxins in wheat (Triticum aestivum) from Serbia. PMID:25585540

  6. Primary subcutaneous Alternaria alternata infection of the hand in an immunocompromised host.

    PubMed

    Kpodzo, Dzifa S; Calderwood, Michael S; Ruchelsman, David E; Abramson, Jeremy S; Piris, Adriano; Winograd, Jonathan M; Kotton, Camille N

    2011-07-01

    We describe a case of a progressive subcutaneous Alternaria alternata infection in the hand of a patient with chronic lymphocytic leukemia (CLL). The diagnosis was based upon the examination of tissue biopsy and isolation of the etiologic agent in culture. The identity of the isolate was determined by phenotypic characteristics and by sequencing the ITS and D1/D2 regions of the rDNA. Despite combination therapy with voriconazole and micafungin, the lesion continued to progress. Posaconazole therapy, along with surgical excision of the infected tissue, resulted in the eradication of infection. The limitations of the clinical management of invasive Alternaria infections are discussed. PMID:21299373

  7. Proteome Analysis of Pathogen-Responsive Proteins from Apple Leaves Induced by the Alternaria Blotch Alternaria alternata

    PubMed Central

    Zhang, Cai-xia; Tian, Yi; Cong, Pei-hua

    2015-01-01

    Understanding the defence mechanisms used by apple leaves against Alternaria alternate pathogen infection is important for breeding purposes. To investigate the ultrastructural differences between leaf tissues of susceptible and resistant seedlings, in vitro inoculation assays and transmission electron microscopy (TEM) analysis were conducted with two different inoculation assays. The results indicated that the resistant leaves may have certain antifungal activity against A. alternate that is lacking in susceptible leaves. To elucidate the two different host responses to A. alternate infection in apples, the proteomes of susceptible and resistant apple leaves that had or had not been infected with pathogen were characterised using two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionisation time-of-flight tandem mass spectrometry (MALDI-TOF-TOF MS). MS identified 43 differentially expressed proteins in two different inoculation assays. The known proteins were categorised into 5 classes, among these proteins, some pathogenesis-related (PR) proteins, such as beta-1,3-glucanase, ascorbate peroxidase (APX), glutathione peroxidase (GPX) and mal d1, were identified in susceptible and resistant hosts and were associated with disease resistance of the apple host. In addition, the different levels of mal d1 in susceptible and resistant hosts may contribute to the outstanding anti-disease properties of resistant leaves against A. alternate. Taken together, the resistance mechanisms of the apple host against A. alternate may be a result of the PR proteins and other defence-related proteins. Given the complexity of the biology involved in the interaction between apple leaves and the A. alternate pathogen, further investigation will yield more valuable insights into the molecular mechanisms of suppression of the A. alternate pathogen. Overall, we outline several novel insights into the response of apple leaves to pathogen attacks. These findings

  8. Carotenoids present in halotolerant Bacillus spore formers.

    PubMed

    Duc, Le H; Fraser, Paul D; Tam, Nguyen K M; Cutting, Simon M

    2006-02-01

    Six isolates of pigmented spore-forming bacteria were recovered from human faeces from subjects in Vietnam. 16S rRNA analysis demonstrated close association with known pigmented Bacillus species. All isolates were able to tolerate growth on 8% NaCl and were resistant to arsenate, characteristics that make them most related to Bacillus indicus. Two visible pigments were apparent, a yellow pigment found in vegetative cells and an orange pigment found only in spores. We used high-performance liquid chromatography to characterize and quantify these pigments and found them to be carotenoids. The biosynthetic pathway that generates them branches with one that could lead to the spore-associated orange pigmentation. Although these bacteria were found in faeces, the seafood-rich diet of Vietnam and the recovery of other pigmented Bacillus species from seafood and marine environments makes it highly probable that the true origin of these bacteria is from ingested seafood. PMID:16448498

  9. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The characteristics of an Airborne Oceanographic Lidar (AOL) are given. The AOL system is described and its potential for various measurement applications including bathymetry and fluorosensing is discussed.

  10. Bacterial spores and chemical sporicidal agents.

    PubMed Central

    Russell, A D

    1990-01-01

    Bacterial spores are among the most resistant of all living cells to biocides, although the response depends on the stage of sporulation. The development of resistance to some agents such as chlorhexidine occurs much earlier in sporulation than does resistance to glutaraldehyde, which is a very late event. During germination or outgrowth or both, resistance is lost and the cells become as susceptible to biocides as nonsporulating bacteria. Mechanisms of spore resistance to, and the action of, biocides are discussed, and possible means of enhancing antispore activity are considered. The clinical and other uses of sporicidal and sporostatic chemical agents are described. Images PMID:2187595

  11. Factors affecting spore germination in algae - review.

    PubMed

    Agrawal, S C

    2009-01-01

    This review surveys whatever little is known on the influence of different environmental factors like light, temperature, nutrients, chemicals (such as plant hormones, vitamins, etc.), pH of the medium, biotic factors (such as algal extracellular substances, algal concentration, bacterial extracellular products, animal grazing and animal extracellular products), water movement, water stress, antibiotics, UV light, X-rays, gamma-rays, and pollution on the spore germination in algae. The work done on the dormancy of algal spores and on the role of vegetative cells in tolerating environmental stress is also incorporated. PMID:19826917

  12. High-Resolution Spore Coat Architecture and Assembly of Bacillus Spores

    SciTech Connect

    Malkin, A J; Elhadj, S; Plomp, M

    2011-03-14

    Elucidating the molecular architecture of bacterial and cellular surfaces and its structural dynamics is essential to understanding mechanisms of pathogenesis, immune response, physicochemical interactions, environmental resistance, and provide the means for identifying spore formulation and processing attributes. I will discuss the application of in vitro atomic force microscopy (AFM) for studies of high-resolution coat architecture and assembly of several Bacillus spore species. We have demonstrated that bacterial spore coat structures are phylogenetically and growth medium determined. We have proposed that strikingly different species-dependent coat structures of bacterial spore species are a consequence of sporulation media-dependent nucleation and crystallization mechanisms that regulate the assembly of the outer spore coat. Spore coat layers were found to exhibit screw dislocations and two-dimensional nuclei typically observed on inorganic and macromolecular crystals. This presents the first case of non-mineral crystal growth patterns being revealed for a biological organism, which provides an unexpected example of nature exploiting fundamental materials science mechanisms for the morphogenetic control of biological ultrastructures. We have discovered and validated, distinctive formulation-specific high-resolution structural spore coat and dimensional signatures of B. anthracis spores (Sterne strain) grown in different formulation condition. We further demonstrated that measurement of the dimensional characteristics of B. anthracis spores provides formulation classification and sample matching with high sensitivity and specificity. I will present data on the development of an AFM-based immunolabeling technique for the proteomic mapping of macromolecular structures on the B. anthracis surfaces. These studies demonstrate that AFM can probe microbial surface architecture, environmental dynamics and the life cycle of bacterial and cellular systems at near

  13. The SPORES experiment of the EXPOSE-R mission: Bacillus subtilis spores in artificial meteorites

    NASA Astrophysics Data System (ADS)

    Panitz, Corinna; Horneck, Gerda; Rabbow, Elke; Rettberg, Petra; Moeller, Ralf; Cadet, Jean; Douki, Thierry

    2015-01-01

    The experiment SPORES `Spores in artificial meteorites' was part of European Space Agency's EXPOSE-R mission, which exposed chemical and biological samples for nearly 2 years (March 10, 2009 to February 21, 2011) to outer space, when attached to the outside of the Russian Zvezda module of the International Space Station. The overall objective of the SPORES experiment was to address the question whether the meteorite material offers enough protection against the harsh environment of space for spores to survive a long-term journey in space by experimentally mimicking the hypothetical scenario of Lithopanspermia, which assumes interplanetary transfer of life via impact-ejected rocks. For this purpose, spores of Bacillus subtilis 168 were exposed to selected parameters of outer space (solar ultraviolet (UV) radiation at λ>110 or >200 nm, space vacuum, galactic cosmic radiation and temperature fluctuations) either as a pure spore monolayer or mixed with different concentrations of artificial meteorite powder. Total fluence of solar UV radiation (100-400 nm) during the mission was 859 MJ m-2. After retrieval the viability of the samples was analysed. A Mission Ground Reference program was performed in parallel to the flight experiment. The results of SPORES demonstrate the high inactivating potential of extraterrestrial UV radiation as one of the most harmful factors of space, especially UV at λ>110 nm. The UV-induced inactivation is mainly caused by photodamaging of the DNA, as documented by the identification of the spore photoproduct 5,6-dihydro-5(α-thyminyl)thymine. The data disclose the limits of Lithopanspermia for spores located in the upper layers of impact-ejected rocks due to access of harmful extraterrestrial solar UV radiation.

  14. Spore Cortex Hydrolysis Precedes Dipicolinic Acid Release during Clostridium difficile Spore Germination

    PubMed Central

    Francis, Michael B.; Allen, Charlotte A.

    2015-01-01

    ABSTRACT Bacterial spore germination is a process whereby a dormant spore returns to active, vegetative growth, and this process has largely been studied in the model organism Bacillus subtilis. In B. subtilis, the initiation of germinant receptor-mediated spore germination is divided into two genetically separable stages. Stage I is characterized by the release of dipicolinic acid (DPA) from the spore core. Stage II is characterized by cortex degradation, and stage II is activated by the DPA released during stage I. Thus, DPA release precedes cortex hydrolysis during B. subtilis spore germination. Here, we investigated the timing of DPA release and cortex hydrolysis during Clostridium difficile spore germination and found that cortex hydrolysis precedes DPA release. Inactivation of either the bile acid germinant receptor, cspC, or the cortex hydrolase, sleC, prevented both cortex hydrolysis and DPA release. Because both cortex hydrolysis and DPA release during C. difficile spore germination are dependent on the presence of the germinant receptor and the cortex hydrolase, the release of DPA from the core may rely on the osmotic swelling of the core upon cortex hydrolysis. These results have implications for the hypothesized glycine receptor and suggest that the initiation of germinant receptor-mediated C. difficile spore germination proceeds through a novel germination pathway. IMPORTANCE Clostridium difficile infects antibiotic-treated hosts and spreads between hosts as a dormant spore. In a host, spores germinate to the vegetative form that produces the toxins necessary for disease. C. difficile spore germination is stimulated by certain bile acids and glycine. We recently identified the bile acid germinant receptor as the germination-specific, protease-like CspC. CspC is likely cortex localized, where it can transmit the bile acid signal to the cortex hydrolase, SleC. Due to the differences in location of CspC compared to the Bacillus subtilis germinant

  15. Study on the ice nucleation activity of fungal spores (Ascomycota and Basidiomycota)

    NASA Astrophysics Data System (ADS)

    Pummer, B. G.; Atanasova, L.; Bauer, H.; Bernardi, J.; Druzhinina, I. S.; Grothe, H.

    2012-04-01

    Biogenic ice nucleation (IN) in the atmosphere is a topic of growing interest, as, according to IPCC, the impact of IN on global climate is crucial to perform reliable climate model calculations. About 20 years ago IN activity of a few lichen and Fusarium species [1,2] was reported, while all other investigated fungi were IN-negative. However, as the fungal kingdom is vast, many abundant species, especially the Basidiomycota (most mushrooms), were not tested before. Furthermore, the focus of the past studies was on the IN activity of the mycelium as a cryoprotective mechanism, and not on the airborne spores. We carried out oil immersion measurements [3] with spores from 17 different fungal species of ecological, economical or sanitary importance. Most of these species have not been investigated before, like exponents of Aspergillus, Trichoderma and Agaricales (most mushrooms). Apart from F. avenaceum, spores of all measured species showed moderate or no IN activity, supporting the hypothesis that significant IN activity is a rather exclusive property of only a few species within the fungal kingdom. [1] Kieft TL and Ruscetti T: J. Bacteriol. 172, 3519-3523, 1990. [2] Pouleur S et al.: Appl. Environ. Microbiol., 58, 2960-2964, 1992. [3] Marcolli C et al.: Atmos. Chem. Phys. 7, 5081-5091, 2007.

  16. Greenhouse germination and characterization of Synchytrium solstitiale resting spores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synchytrium solstitiale was evaluated for suitability in biological control of yellow starthisle (YST). A protocol was developed for maintenance of S. solstitiale in galled tissue under greenhouse conditions. Recently, protocol has been developed for germination of resting spores. Resting spores ...

  17. Surface tension propulsion of fungal spores by use of microdroplets

    NASA Astrophysics Data System (ADS)

    Noblin, Xavier; Yang, Sylvia; Dumais, Jacques

    2010-11-01

    Most basidiomycete fungi (such as edible mushrooms) actively eject their spores. The process begins with the condensation of a water droplet at the base of the spore. The fusion of the droplet onto the spore creates a momentum that propels the spore forward. The use of surface tension for spore ejection offers a new paradigm to perform work at small length scales. However, this mechanism of force generation remains poorly understood. To elucidate how fungal spores make effective use of surface tension, we performed high-speed video imaging of spore ejection in Auricularia auricula and Sporobolomyces yeast, along with a detailed mechanical analysis of the spore ejection. We developed an explicit relation for the conversion of surface energy into kinetic energy during the coalescence process. The relation was validated with a simple artificial system.

  18. Interaction of antimicrobial cyclic lipopeptides from Bacillus subtilis influences their effect on spore germination and membrane permeability in fungal plant pathogens.

    PubMed

    Liu, Jiajie; Hagberg, Ingrid; Novitsky, Laura; Hadj-Moussa, Hanane; Avis, Tyler J

    2014-11-01

    Bacillus subtilis cyclic lipopeptides are known to have various antimicrobial effects including different types of interactions with the cell membranes of plant pathogenic fungi. The various spectra of activities of the three main lipopeptide families (fengycins, iturins, and surfactins) seem to be linked to their respective mechanisms of action on the fungal biomembrane. Few studies have shown the combined effect of more than one family of lipopeptides on fungal plant pathogens. In an effort to understand the effect of producing multiple lipopeptide families, sensitivity and membrane permeability of spores from four fungal plant pathogens (Alternaria solani, Fusarium sambucinum, Rhizopus stolonifer, and Verticillium dahliae) were assayed in response to lipopeptides, both individually and as combined treatments. Results showed that inhibition of spores was highly variable depending on the tested fungus-lipopeptide treatment. Results also showed that inhibition of the spores was closely associated with SYTOX stain absorption suggesting effects of efficient treatments on membrane permeability. Combined lipopeptide treatments revealed additive, synergistic or sometimes mutual inhibition of beneficial effects. PMID:25442289

  19. Resistance to alternaria solani in hybrids between a Solanum tuberosum haploid and S. raphanifolium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early blight of potato (Solanum tuberosum L.), caused by the foliar fungal pathogen Alternaria solani is a major cause of economic loss in many potato growing regions. Genetic resistance offers an opportunity to decrease fungicide usage while maintaining yield and quality. In this study, an early bl...

  20. Genome sequence of a novel mitovirus identified in the phytopathogenic fungus Alternaria arborescens.

    PubMed

    Komatsu, Ken; Katayama, Yukie; Omatsu, Tsutomu; Mizutani, Tetsuya; Fukuhara, Toshiyuki; Kodama, Motoichiro; Arie, Tsutomu; Teraoka, Tohru; Moriyama, Hiromitsu

    2016-09-01

    The phytopathogenic fungus Alternaria spp. contains a variety of double-stranded RNA (dsRNA) elements of different sizes. Detailed analysis of next-generation sequencing data obtained using dsRNA purified from Alternaria arborescens, from which we had previously found Alternaria arborescens victorivirus 1, revealed the presence of another mycoviral-like dsRNA of approximately 2.5 kbp in length. When using the fungal mitochondrial genetic code, this dsRNA has a single open reading frame that potentially encodes an RNA-dependent RNA polymerase (RdRp) with significant to sequence similarity to those of viruses of the genus Mitovirus. Moreover, both the 5'- and 3'-untranslated regions have the potential to fold into stable stem-loop structures, which is characteristic of mitoviruses. Pairwise comparisons and phylogenetic analysis of the deduced amino acid sequences of RdRp indicated that the virus we identified in A. arborescens is a distinct member of the genus Mitovirus in the family Narnaviridae, designated as "Alternaria arborescens mitovirus 1" (AaMV1). PMID:27368994

  1. Identification and functional analysis of brassicicene C biosynthetic gene cluster in Alternaria brassicicola.

    PubMed

    Minami, Atsushi; Tajima, Naoto; Higuchi, Yusuke; Toyomasu, Tomonobu; Sassa, Takeshi; Kato, Nobuo; Dairi, Tohru

    2009-02-01

    The biosynthetic gene cluster of brassicicene C was identified in Alternaria brassicicola strain ATCC 96836 from genome database search. In vivo and in vitro study clearly revealed the function of Orf8 and Orf6 as a fusicoccadiene synthase and methyltransferase, respectively. The understanding toward the biosynthetic pathway promises construction of this type of diterpene compounds with genetic engineering. PMID:19097780

  2. Antileukemic alpha-pyrone derivatives from the endophytic fungus Alternaria phragmospora

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four new (1–4) and two known (5 and 6)a-pyrone derivatives have been isolated from Alternaria phragmospora, an endophytic fungus from Vinca rosea, leaves. The isolated compounds were chemically identi'ed to be 5-butyl-4-methoxy-6-methyl-2H-pyran-2-one (2) 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-py...

  3. Analysis of genetic and pathogenic variation among Alternaria solani in a potato production region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two-year survey was conducted in a potato production region to investigate the genetic variability within naturally infecting populations of Alternaria solani, the cause of early blight in potato, and between species A. solani and A. dauci. Genetic diversity among 151 isolates was assessed using s...

  4. Biochemical Evaluation of Resistance Responses of Potato to Different Isolates of Alternaria Solani

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The resistance phenotypes of nine potato cultivars to five isolates of Alternaria solani, causal agent of early blight, were studied after inoculation and growth under greenhouse conditions. We identified potato cultivars with both susceptible and resistant phenotypes as well as A. solani isolates ...

  5. Effect of Alternaria solani exudates on resistant and susceptible potato cultivars from two different pathogen isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The resistance phenotypes of two potato cultivars to two isolates of Alternaria solani, causal agent of early blight, were studied under greenhouse conditions. The two isolates contain varying degrees of aggressiveness on both susceptible and resistant phenotypes of potatoes. A bioassay was used to ...

  6. Stability of Sweet Potato Cultivars to Alternaria Leaf and Stem Blight Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria leaf petiole and stem blight is an economically important disease of sweet potato (Ipomoea batatus L) in tropical and sub-tropical environments. Published research on cultivar resistance to the sweet potato disease is limited. To evaluate cultivar reaction and stability to the disease, mu...

  7. Fifth international fungus spore conference. [Abstracts]: Final technical report

    SciTech Connect

    Timberlake, W.E.

    1993-04-01

    This folio contains the proceedings of the Fifth International Fungal Spore Conference held August 17-21, 1991 at the Unicoi State Park at Helen, Georgia. The volume contains abstracts of each oral presentation as well as a collection of abstracts describing the poster sessions. Presentations were organized around the themes (1) Induction of Sporulation, (2) Nuclear Division, (3) Spore Formation, (4) Spore Release and Dispersal, and (4) Spore Germination.

  8. Decontamination of Bacillus anthracis Spores: Evaluation of Various Disinfectants

    PubMed Central

    Heninger, Sara J.; Anderson, Christine A.; Beltz, Gerald; Onderdonk, Andrew B.

    2009-01-01

    The present study compares the efficacy of various disinfectants against Bacillus anthracis spores. While Bleach Rite® and 10% bleach reduce spore numbers by 90% within 10 minutes, a long contact time is required for complete disinfection. By contrast, although SporGon® did not initially reduce the number of spores as quickly as Bleach Rite or 10% bleach, shorter contact times were required for complete eradication of viable spores. PMID:20967138

  9. Photocontrol of the Germination of Onoclea Spores

    PubMed Central

    Towill, Leslie R.; Ikuma, Hiroshi

    1973-01-01

    Light stimulates the germination of spores of the fern Onoclea sensibilis L. At high dosages, broad band red, far red, and blue light promote maximal germination. Maximal sensitivity to these spectral regions is attained from 6 to 48 hours of dark presoaking, and all induced rapid germination after a lag of 30 to 36 hours. Maximal germination is attained approximately 70 hours after irradiation. Dose response curves suggest log linearity. The action spectrum to cause 50% germination shows that spores are most sensitive to irradiation in the red region (620-680 nm) with an incident energy less than 1000 ergs cm−2; sensitivity decreases towards both shorter and longer wavelengths. Although the action spectrum is suggestive of phytochrome involvement, photoreversibility of germination between red and far red light has not been demonstrated with Onoclea spores. An absorption spectrum of the intact spores reveals the presence of chlorophylls and carotenoids. Since the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea does not inhibit germination, it is concluded that photosynthesis does not play a role in the germination process. PMID:16658448

  10. Real time viability detection of bacterial spores

    DOEpatents

    Vanderberg, Laura A.; Herdendorf, Timothy J.; Obiso, Richard J.

    2003-07-29

    This invention relates to a process for detecting the presence of viable bacterial spores in a sample and to a spore detection system, the process including placing a sample in a germination medium for a period of time sufficient for commitment of any present viable bacterial spores to occur, mixing the sample with a solution of a lanthanide capable of forming a fluorescent complex with dipicolinic acid, and, measuring the sample for the presence of dipicolinic acid, and the system including a germination chamber having inlets from a sample chamber, a germinant chamber and a bleach chamber, the germination chamber further including an outlet through a filtering means, the outlet connected to a detection chamber, the detection chamber having an inlet from a fluorescence promoting metal chamber and the detection chamber including a spectral excitation source and a means of measuring emission spectra from a sample, the detection chamber further connected to a waste chamber. A germination reaction mixture useful for promoting commitment of any viable bacterial spores in a sample including a combination of L-alanine, L-asparagine and D-glucose is also described.

  11. Requirements for in vitro germination of Paenibacillus larvae spores.

    PubMed

    Alvarado, Israel; Phui, Andy; Elekonich, Michelle M; Abel-Santos, Ernesto

    2013-03-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), a disease affecting honey bee larvae. First- and second-instar larvae become infected when they ingest food contaminated with P. larvae spores. The spores then germinate into vegetative cells that proliferate in the midgut of the honey bee. Although AFB affects honey bees only in the larval stage, P. larvae spores can be distributed throughout the hive. Because spore germination is critical for AFB establishment, we analyzed the requirements for P. larvae spore germination in vitro. We found that P. larvae spores germinated only in response to l-tyrosine plus uric acid under physiologic pH and temperature conditions. This suggests that the simultaneous presence of these signals is necessary for spore germination in vivo. Furthermore, the germination profiles of environmentally derived spores were identical to those of spores from a biochemically typed strain. Because l-tyrosine and uric acid are the only required germinants in vitro, we screened amino acid and purine analogs for their ability to act as antagonists of P. larvae spore germination. Indole and phenol, the side chains of tyrosine and tryptophan, strongly inhibited P. larvae spore germination. Methylation of the N-1 (but not the C-3) position of indole eliminated its ability to inhibit germination. Identification of the activators and inhibitors of P. larvae spore germination provides a basis for developing new tools to control AFB. PMID:23264573

  12. Imaging bacterial spores by soft-x-ray microscopy

    SciTech Connect

    Stead, A.D.; Ford, T.W.; Judge, J.

    1997-04-01

    Bacterial spores are able to survive dehydration, but neither the physiological nor structural basis of this have been fully elucidated. Furthermore, once hydrated, spores often require activation before they will germinate. Several treatments can be used to activate spores, but in the case of Bacillus subtlis the most effective is heat treatment. The physiological mechanism associated with activation is also not understood, but some workers suggest that the loss of calcium from the spores may be critical. However, just prior to germination, the spores change from being phase bright to phase dark when viewed by light microscopy. Imaging spores by soft x-ray microscopy is possible without fixation. Thus, in contrast to electron microscopy, it is possible to compare the structure of dehydrated and hydrated spores in a manner not possible previously. A further advantage is that it is possible to monitor individual spores by phase contrast light microscopy immediately prior to imaging with soft x-rays; whereas, with both electron microscopy and biochemical studies, it is a population of spores being studied without knowledge of the phase characteristics of individual spores. This study has therefore tried to compare dehydrated and hydrated spores and to determine if there is a mass loss from individual spores as they pass the transition from being phase bright to phase dark.

  13. Classification of Streptomyces Spore Surfaces into Five Groups

    PubMed Central

    Dietz, Alma; Mathews, John

    1971-01-01

    Streptomyces spores surfaces have been classified into five groups, smooth, warty, spiny, hairy, and rugose, by examination of carbon replicas of spores with the transmission electron microscope and by direct examination of spores with the scanning electron microscope. Images PMID:4928607

  14. Single-spore elemental analyses indicate that dipicolinic acid-deficient Bacillus subtilis spores fail to accumulate calcium.

    PubMed

    Hintze, Paul E; Nicholson, Wayne L

    2010-06-01

    Dipicolinic acid (pyridine-2,6-carboxylic acid; DPA) is a major component of bacterial spores and has been shown to be an important determinant of spore resistance. In the core of dormant Bacillus subtilis spores, DPA is associated with divalent calcium in a 1:1 chelate (Ca-DPA). Spores excrete Ca-DPA during germination, but it is unknown whether Ca and DPA are imported separately or together into the developing spore. Elemental analysis by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) of wild-type spores and mutant spores lacking the ability to synthesize DPA showed that DPA-less spores also lacked calcium, suggesting that the two compounds may be co-imported. PMID:20396869

  15. Genome Diversity of Spore-Forming Firmicutes

    PubMed Central

    Galperin, Michael Y.

    2015-01-01

    Summary Formation of heat-resistant endospores is a specific property of the members of the phylum Firmicutes (low-G+C Gram-positive bacteria). It is found in representatives of four different classes of Firmicutes: Bacilli, Clostridia, Erysipelotrichia, and Negativicutes, which all encode similar sets of core sporulation proteins. Each of these classes also includes non-spore-forming organisms that sometimes belong to the same genus or even species as their spore-forming relatives. This chapter reviews the diversity of the members of phylum Firmicutes, its current taxonomy, and the status of genome sequencing projects for various subgroups within the phylum. It also discusses the evolution of the Firmicutes from their apparently spore-forming common ancestor and the independent loss of sporulation genes in several different lineages (staphylococci, streptococci, listeria, lactobacilli, ruminococci) in the course of their adaptation to the saprophytic lifestyle in nutrient-rich environment. It argues that systematics of Firmicutes is a rapidly developing area of research that benefits from the evolutionary approaches to the ever-increasing amount of genomic and phenotypic data and allows arranging these data into a common framework. Later the Bacillus filaments begin to prepare for spore formation. In their homogenous contents strongly refracting bodies appear. From each of these bodies develops an oblong or shortly cylindrical, strongly refracting, dark-rimmed spore. Ferdinand Cohn. 1876. Untersuchungen über Bacterien. IV. Beiträge zur Biologie der Bacillen. Beiträge zur Biologie der Pflanzen, vol. 2, pp. 249–276. (Studies on the biology of the bacilli. In: Milestones in Microbiology: 1546 to 1940. Translated and edited by Thomas D. Brock. Prentice-Hall, Englewood Cliffs, NJ, 1961, pp. 49–56). PMID:26184964

  16. Characterization of Airborne Bacteria at an Underground Subway Station

    PubMed Central

    Dybwad, Marius; Granum, Per Einar; Bruheim, Per

    2012-01-01

    The reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization–time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the genera Bacillus, Micrococcus, and Staphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers. PMID:22247150

  17. Characterization of airborne bacteria at an underground subway station.

    PubMed

    Dybwad, Marius; Granum, Per Einar; Bruheim, Per; Blatny, Janet Martha

    2012-03-01

    The reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization-time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the genera Bacillus, Micrococcus, and Staphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers. PMID:22247150

  18. Development of an approach to analyze the interaction between Nosema bombycis (microsporidia) deproteinated chitin spore coats and spore wall proteins.

    PubMed

    Yang, Donglin; Dang, Xiaoqun; Tian, Rui; Long, Mengxian; Li, Chunfeng; Li, Tian; Chen, Jie; Li, Zhi; Pan, Guoqing; Zhou, Zeyang

    2014-01-01

    Nosema bombycis is an obligate intracellular parasite of the Bombyx mori insect. The spore wall of N. bombycis is composed of an electron-dense proteinaceous outer layer and an electron-transparent chitinous inner layer, and the spore wall is connected to the plasma membrane. In this study, the deproteinated chitin spore coats (DCSCs) were acquired by boiling N. bombycis in 1M NaOH. Under a transmission electron microscope, the chitin spore coat resembles a loosely curled ring with strong refractivity; organelles and nuclei were not observed inside the spore. The anti-SWP25, 26, 30 and 32 antibodies were used to detect whether spore wall proteins within the total soluble and mature spore proteins could bind to the DCSCs. Furthermore, a chitin binding assay showed that within the total soluble and mature spore proteins, the SWP26, SWP30 and SWP32 spore wall proteins, bound to the deproteinated chitin spore coats, although SWP25 was incapable of this interaction. Moreover, after the DCSCs were incubated with the alkali-soluble proteins, the latter were obtained by treating N. bombycis with 0.1M NaOH. Following this treatment, SWP32 was still capable of binding the DCSCs, while SWP26 and SWP30 were unable to bind. Collectively, the DCSCs are useful for investigating the arrangement of spore wall proteins, and they shed light on how the microsporidia spore wall is self-assembled. PMID:24161881

  19. Studies on propagation of microbes in the airborne state

    NASA Technical Reports Server (NTRS)

    Dimmick, R. L.; Wolochow, H.; Straat, P.; Chatigny, M. A.

    1974-01-01

    An investigation was conducted to demonstrate whether airborne microbes could propagate. The procedure consisted of: (1) looking for dilution of a labelled base in DNA; (2) looking for labelling of DNA by mixing aerosols of the label and the cells; (3) examining changes in cell size; (4) testing the possibility of spore germination; and (5) seeking evidence of an increase in cell number. Results indicate that growth and propagation can occur under special conditions, principally at temperatures of approximately 30 C (87 F) and water activity equivalents of 0.95 to 0.98.

  20. Back-trajectory modelling and DNA-based species-specific detection methods allow tracking of fungal spore transport in air masses.

    PubMed

    Grinn-Gofroń, Agnieszka; Sadyś, Magdalena; Kaczmarek, Joanna; Bednarz, Aleksandra; Pawłowska, Sylwia; Jedryczka, Malgorzata

    2016-11-15

    Recent advances in molecular detection of living organisms facilitate the introduction of novel methods to studies of the transport of fungal spores over large distances. Monitoring the migration of airborne fungi using microscope based spore identification is limited when different species produce very similar spores. In our study, DNA-based monitoring with the use of species-specific probes allowed us to track the aerial movements of two important fungal pathogens of oilseed rape (Brassica napus L.), i.e., Leptosphaeria maculans and Leptosphaeria biglobosa, which have identical spore shape and size. The fungi were identified using dual-labelled fluorescent probes that were targeted to a β-tubulin gene fragment of either Leptosphaeria species. Spore identification by Real-Time PCR techniques capable of detecting minute amounts of DNA of selected fungal species was combined with back-trajectory analysis, allowing the tracking of past movements of air masses using the Hybrid Single Particle Lagrangian Integrated Trajectory model. Over a study period spanning the previous decade (2006-2015) we investigated two specific events relating to the long distance transport of Leptosphaeria spp. spores to Szczecin in North-West Poland. Based on the above mentioned methods and the results obtained with the additional spore sampler located in nearby Szczecin, and operating at the ground level in an oilseed rape field, we have demonstrated that on both occasions the L. biglobosa spores originated from the Jutland Peninsula. This is the first successful attempt to combine analysis of back-trajectories of air masses with DNA-based identification of economically important pathogens of oilseed rape in Europe. In our studies, the timing of L. biglobosa ascospore dispersal in the air was unlikely to result in the infection of winter oilseed rape grown as a crop plant. However, the fungus could infect other host plants, such as vegetable brassicas, cruciferous weeds, spring rapeseed

  1. A laboratory assessment of the Waveband Integrated Bioaerosol Sensor (WIBS-4) using individual samples of pollen and fungal spore material

    NASA Astrophysics Data System (ADS)

    Healy, David A.; O'Connor, David J.; Burke, Aoife M.; Sodeau, John R.

    2012-12-01

    A Bioaerosol sensing instrument referred to as WIBS-4, designed to continuously monitor ambient bioaerosols on-line, has been used to record a multiparameter “signature” from each of a number of Primary Biological Aerosol Particulate (PBAP) samples found in air. These signatures were obtained in a controlled laboratory environment and are based on the size, asymmetry (“shape”) and auto-fluorescence of the particles. Fifteen samples from two separate taxonomic ranks (kingdoms), Plantae (×8) and Fungi (×7) were individually introduced to the WIBS-4 for measurement along with two non-fluorescing chemical solids, common salt and chalk. Over 2000 individual-particle measurements were recorded for each sample type and the ability of the WIBS spectroscopic technique to distinguish between chemicals, pollen and fungal spore material was examined by identifying individual PBAP signatures. The results obtained show that WIBS-4 could potentially be a very useful analytical tool for distinguishing between natural airborne PBAP samples, such as the fungal spores and may potentially play an important role in detecting and discriminating the toxic fungal spore, Aspergillus fumigatus, from others in real-time. If the sizing range of the commercial instrument was customarily increased and permitted to operate simultaneously in its two sizing ranges, pollen and spores could potentially be discriminated between. The data also suggest that the gain setting sensitivity on the detector would also have to be reduced by a factor >5, to routinely detect, in-range fluorescence measurements for pollen samples.

  2. Sources of Variability in the Measurement of Fungal Spore Yields

    PubMed Central

    Smith, C. S.; Slade, S. J.; Nordheim, E. V.; Cascino, J. J.; Harris, R. F.; Andrews, J. H.

    1988-01-01

    Variability in the production of fungal spores and in the measurement of spore yields was investigated in four species of fungi: Colletotrichum gloeosporioides, Colletotrichum coccodes, Colletotrichum phomoides, and Acremonium strictum. When the fungi were grown on solid medium in microplates and spore yields were measured by counting the subsamples with a hemacytometer, the variability among hemacytometer squares was always the largest source of variation, accounting for 51 to 91% of the total variation. Variability among replicate cultures and results of repeat experiments were generally also significant. The effect of square-to-square variability on the precision of spore yield measurement was minimized by counting a moderate number (ca. 30) of squares per culture. Culture-to-culture variability limited the practical precision of spore production measurements to a 95% confidence interval of approximately the mean ± 25%. We provide guidelines for determining the number of replicate cultures required to attain this or other degrees of precision. Particle counter-derived spore counts and counts based on spore weights were much less variable than were hemacytometer counts, but they did not improve spore production estimates very much because of culture-to-culture variability. Results obtained by both of these methods differed from those obtained with a hemacytometer; particle counter measurements required a correction for spore pairs, while the relationship between spore weights and spore counts changed as the cultures aged. PMID:16347653

  3. Regulation of trehalose metabolism by Streptomyces griseus spores.

    PubMed Central

    McBride, M J; Ensign, J C

    1990-01-01

    Spores of Streptomyces griseus contain trehalose and trehalase, but trehalose is not readily hydrolyzed until spore germination is initiated. Trehalase in crude extracts of spores, germinated spores, and mycelia of S. griseus had a pH optimum of approximately 6.2, had a Km value for trehalose of approximately 11 mM, and was most active in buffers having ionic strengths of 50 to 200 mM. Inhibitors or activators or trehalase activity were not detected in extracts of spores or mycelia. Several lines of evidence indicated that trehalose and trehalase are both located in the spore cytoplasm. Spores retained their trehalose and most of their trehalase activity following brief exposure to dilute acid. Protoplasts formed by enzymatic removal of the spore walls in buffer containing high concentrations of solutes also retained their trehalose and trehalase activity. Protoplasts formed in buffer containing lower levels of solutes contained low levels of trehalose. The mechanism by which trehalose metabolism is regulated in S. griseus spores is unresolved. A low level of hydration of the cytoplasm of the dormant spores and an increased level of hydration during germination may account for the apparent inactivity of trehalase in dormant spores and the rapid hydrolysis of trehalose upon initiation of germination. Images PMID:2113908

  4. Monitoring Rates and Heterogeneity of High-Pressure Germination of Bacillus Spores by Phase-Contrast Microscopy of Individual Spores

    PubMed Central

    Kong, Lingbo; Doona, Christopher J.; Setlow, Peter

    2014-01-01

    Germination of Bacillus spores with a high pressure (HP) of ∼150 MPa is via activation of spores' germinant receptors (GRs). The HP germination of multiple individual Bacillus subtilis spores in a diamond anvil cell (DAC) was monitored with phase-contrast microscopy. Major conclusions were that (i) >95% of wild-type spores germinated in 40 min in a DAC at ∼150 MPa and 37°C but individual spores' germination kinetics were heterogeneous; (ii) individual spores' HP germination kinetic parameters were similar to those of nutrient-triggered germination with a variable lag time (Tlag) prior to a period of the rapid release (ΔTrelease) of the spores' dipicolinic acid in a 1:1 chelate with Ca2+ (CaDPA); (iii) spore germination at 50 MPa had longer average Tlag values than that at ∼150 MPa, but the ΔTrelease values at the two pressures were identical and HPs of <10 MPa did not induce germination; (iv) B. subtilis spores that lacked the cortex-lytic enzyme CwlJ and that were germinated with an HP of 150 MPa exhibited average ΔTrelease values ∼15-fold longer than those for wild-type spores, but the two types of spores exhibited similar average Tlag values; and (v) the germination of wild-type spores given a ≥30-s 140-MPa HP pulse followed by a constant pressure of 1 MPa was the same as that of spores exposed to a constant pressure of 140 MPa that was continued for ≥35 min; (vi) however, after short 150-MPa HP pulses and incubation at 0.1 MPa (ambient pressure), spore germination stopped 5 to 10 min after the HP was released. These results suggest that an HP of ∼150 MPa for ≤30 s is sufficient to fully activate spores' GRs, which remain activated at 1 MPa but can deactivate at ambient pressure. PMID:24162576

  5. Airborne gravity is here

    SciTech Connect

    Hammer, S.

    1982-01-11

    After 20 years of development efforts, the airborne gravity survey has finally become a practical exploration method. Besides gravity data, the airborne survey can also collect simultaneous, continuous records of high-precision magneticfield data as well as terrain clearance; these provide a topographic contour map useful in calculating terrain conditions and in subsequent planning and engineering. Compared with a seismic survey, the airborne gravity method can cover the same area much more quickly and cheaply; a seismograph could then detail the interesting spots.

  6. Activation and injury of Clostridium perfringens spores by alcohols.

    PubMed Central

    Craven, S E; Blankenship, L C

    1985-01-01

    The activation properties of Clostridium perfringens NCTC 8679 spores were demonstrated by increases in CFU after heating in water or aqueous alcohols. The temperature range for maximum activation, which was 70 to 80 degrees C in water, was lowered by the addition of alcohols. The response at a given temperature was dependent on the time of exposure and the alcohol concentration. The monohydric alcohols and some, but not all, of the polyhydric alcohols could activate spores at 37 degrees C. The concentration of a monohydric alcohol that produced optimal spore activation was inversely related to its lipophilic character. Spore injury, which was manifested as a dependence on lysozyme for germination and colony formation, occurred under some conditions of alcohol treatment that exceeded those for optimal spore activation. Treatment with aqueous solutions of monohydric alcohols effectively activated C. perfringens spores and suggests a hydrophobic site for spore activation. PMID:2864897

  7. Surface Display of Recombinant Proteins on Bacillus subtilis Spores

    PubMed Central

    Isticato, Rachele; Cangiano, Giuseppina; Tran, Hoa T.; Ciabattini, Annalisa; Medaglini, Donata; Oggioni, Marco R.; De Felice, Maurilio; Pozzi, Gianni; Ricca, Ezio

    2001-01-01

    We developed a novel surface display system based on the use of bacterial spores. A protein of the Bacillus subtilis spore coat, CotB, was found to be located on the spore surface and used as fusion partner to express the 459-amino-acid C-terminal fragment of the tetanus toxin (TTFC). Western, dot blot and fluorescent-activated cell sorting analyses were used to monitor TTFC surface expression on purified spores. We estimated that more than 1.5 × 103 TTFC molecules were exposed on the surface of each spore and recognized by TTFC-specific antibodies. The efficient surface presentation of the heterologous protein, together with the simple purification procedure and the high stability and safety record of B. subtilis spores, makes this spore-based display system a potentially powerful approach for surface expression of bioactive molecules. PMID:11591673

  8. Revival of biocide-treated spores of Bacillus subtilis.

    PubMed

    Williams, N D; Russell, A D

    1993-07-01

    Spores of Bacillus subtilis NCTC 8236 were treated with biocides and then subjected to various revival procedures. Sodium hydroxide (optimum concentration 25 mmol l-1) revived a small portion of glutaraldehyde-treated spores but not of spores exposed to formaldehyde, polyvinylpyrrolidone-iodine (PVP-I), Lugol's iodine, sodium hypochlorite or sodium dichloroisocyanurate (NaDCC). Post-treatment heat shock (at 70 degrees or 80 degrees C) increased the numbers of colony-forming units (cfu) of formaldehyde-injured spores. Coat-extraction procedures had the greatest effect on iodine-pretreated spores. The uptake of iodine and chlorine was more rapid and occurred to a greater extent with outgrowing, germinating and especially coat-deficient spores than with mature, resting spores. PMID:7690020

  9. Mushrooms use convectively created airflows to disperse their spores.

    PubMed

    Dressaire, Emilie; Yamada, Lisa; Song, Boya; Roper, Marcus

    2016-03-15

    Thousands of basidiomycete fungal species rely on mushroom spores to spread across landscapes. It has long been thought that spores depend on favorable winds for dispersal--that active control of spore dispersal by the parent fungus is limited to an impulse delivered to the spores to carry them clear of the gill surface. Here we show that evaporative cooling of the air surrounding the pileus creates convective airflows capable of carrying spores at speeds of centimeters per second. Convective cells can transport spores from gaps that may be only 1 cm high and lift spores 10 cm or more into the air. This work reveals how mushrooms tolerate and even benefit from crowding and explains their high water needs. PMID:26929324

  10. Wavelet-based fractal analysis of airborne pollen

    NASA Astrophysics Data System (ADS)

    Degaudenzi, M. E.; Arizmendi, C. M.

    1999-06-01

    The most abundant biological particles in the atmosphere are pollen grains and spores. Self-protection of a pollen allergy is possible through information about future pollen contents in the air. In spite of the importance of airborne pollen concentration forecasting, it has not been possible to predict the pollen concentrations with great accuracy, and about 25% of daily pollen forecasts result in failures. Previous analyses of the dynamic characteristics of atmospheric pollen time series indicate that the system can be described by a low dimensional chaotic map. We apply a wavelet transform to study the multifractal characteristics of an airborne pollen time series. The information and the correlation dimensions correspond to a chaotic system showing a loss of information with time evolution.

  11. Fern Spore Longevity in Saline Water: Can Sea Bottom Sediments Maintain a Viable Spore Bank?

    PubMed Central

    de Groot, G. Arjen; During, Heinjo

    2013-01-01

    Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation’s diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and - in sea bottoms - salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding) emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal. PMID:24223951

  12. Effects of simulated rainfall on disease development and weed control of the bioherbicidal fungi Alternaria cassiae and Colletotrichum truncatum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria cassiae and Colletotrichum truncatum are virulent pathogens of sicklepod (Senna obtusifolia), and hemp sesbania (Sesbania exaltata), respectively, under favorable environmental conditions. In greenhouse experiments, the effects of simulated rainfall on pathogenesis and mortality of these ...

  13. Microplate Assay for Colletotrichum Spore Production

    PubMed Central

    Slade, S. J.; Harris, R. F.; Smith, C. S.; Andrews, J. H.; Nordheim, E. V.

    1987-01-01

    A simple microplate method was devised to assay spore production by Colletotrichum gloeosporioides by growing the fungus on 1 ml of solid media in the wells of tissue culture plates. Growth and sporulation on microplates were compared at days 4 and 8 with growth and sporulation in 100-ml liquid batch cultures that involved 11 common media. Spore production per unit volume of medium was the same for solid and liquid forms of the media. Qualitative assessment of mycelial growth measured on microplates agreed with that of growth measured in liquid cultures. The microplate assay indicated that V8 juice was the best medium and that an organic content of about 6 mg/ml was optimal for high sporulation and low mycelium production. The assay provides a convenient, rapid, and inexpensive means of screening media for the production of fungal conidia in large numbers, to be used, for example, in biological control programs. PMID:16347310

  14. Chemical syntheses of oligodeoxyribonucleotides containing spore photoproduct

    PubMed Central

    Jian, Yajun; Li, Lei

    2013-01-01

    5-(α-Thyminyl)-5,6-dihydrothymine, also called spore photoproduct or SP, is commonly found in the genomic DNA of UV irradiated bacterial endospores. Despite the fact that SP was discovered nearly 50 years ago, its biochemical impact is still largely unclear due to the difficulty to prepare SP containing oligonucleotide in high purity. Here, we report the first synthesis of the phosphoramidite derivative of dinucleotide SP TpT, which enables successful incorporation of SP TpT into oligodeoxyribonucleotides with high efficiency via standard solid phase synthesis. This result provides the scientific community a reliable means to prepare SP containing oligonucleotides, laying the foundation for future SP biochemical studies. Thermal denaturation studies of the SP containing oligonucleotide found that SP destabilizes the duplex by 10–20 kJ/mole, suggesting that its presence in the spore genomic DNA may alter the DNA local conformation. PMID:23506239

  15. CLOSTRIDIUM SPORE ATTACHMENT TO HUMAN CELLS

    SciTech Connect

    PANESSA-WARREN,B.; TORTORA,G.; WARREN,J.

    1997-08-10

    This paper uses high resolution scanning electron microscopy (SEM) with a LaB6 gun and the newest commercial field emission guns, to obtain high magnification images of intact clostridial spores throughout the activation/germination/outgrowth process. By high resolution SEM, the clostridial exosporial membrane can be seen to produce numerous delicate projections (following activation), that extend from the exosporial surface to a nutritive substrate (agar), or cell surface when anaerobically incubated in the presence of human cells (embryonic fibroblasts and colon carcinoma cells). Magnifications of 20,000 to 200,000Xs at accelerating voltages low enough to minimize or eliminate specimen damage (1--5 kV) have permitted the entire surface of C.sporogenes and C.difficile endospores to be examined during all stages of germination. The relationships between the spore and the agar or human cell surface were also clearly visible.

  16. Toolsets for Airborne Data

    Atmospheric Science Data Center

    2015-04-02

    article title:  Toolsets for Airborne Data     View larger image The ... limit of detection values. Prior to accessing the TAD Web Application ( https://tad.larc.nasa.gov ) for the first time, users must ...

  17. Diversity and Composition of Airborne Fungal Community Associated with Particulate Matters in Beijing during Haze and Non-haze Days

    PubMed Central

    Yan, Dong; Zhang, Tao; Su, Jing; Zhao, Li-Li; Wang, Hao; Fang, Xiao-Mei; Zhang, Yu-Qin; Liu, Hong-Yu; Yu, Li-Yan

    2016-01-01

    To assess the diversity and composition of airborne fungi associated with particulate matters (PMs) in Beijing, China, a total of 81 PM samples were collected, which were derived from PM2.5, PM10 fractions, and total suspended particles during haze and non-haze days. The airborne fungal community in these samples was analyzed using the Illumina Miseq platform with fungi-specific primers targeting the internal transcribed spacer 1 region of the large subunit rRNA gene. A total of 797,040 reads belonging to 1633 operational taxonomic units were observed. Of these, 1102 belonged to Ascomycota, 502 to Basidiomycota, 24 to Zygomycota, and 5 to Chytridiomycota. The dominant orders were Pleosporales (29.39%), Capnodiales (27.96%), Eurotiales (10.64%), and Hypocreales (9.01%). The dominant genera were Cladosporium, Alternaria, Fusarium, Penicillium, Sporisorium, and Aspergilus. Analysis of similarities revealed that both particulate matter sizes (R = 0.175, p = 0.001) and air quality levels (R = 0.076, p = 0.006) significantly affected the airborne fungal community composition. The relative abundance of many fungal genera was found to significantly differ among various PM types and air quality levels. Alternaria and Epicoccum were more abundant in total suspended particles samples, Aspergillus in heavy-haze days and PM2.5 samples, and Malassezia in PM2.5 samples and heavy-haze days. Canonical correspondence analysis and permutation tests showed that temperature (p < 0.01), NO2 (p < 0.01), PM10 (p < 0.01), SO2(p < 0.01), CO (p < 0.01), and relative humidity (p < 0.05) were significant factors that determine airborne fungal community composition. The results suggest that diverse airborne fungal communities are associated with particulate matters and may provide reliable data for studying the responses of human body to the increasing level of air pollution in Beijing. PMID:27148180

  18. Diversity and Composition of Airborne Fungal Community Associated with Particulate Matters in Beijing during Haze and Non-haze Days.

    PubMed

    Yan, Dong; Zhang, Tao; Su, Jing; Zhao, Li-Li; Wang, Hao; Fang, Xiao-Mei; Zhang, Yu-Qin; Liu, Hong-Yu; Yu, Li-Yan

    2016-01-01

    To assess the diversity and composition of airborne fungi associated with particulate matters (PMs) in Beijing, China, a total of 81 PM samples were collected, which were derived from PM2.5, PM10 fractions, and total suspended particles during haze and non-haze days. The airborne fungal community in these samples was analyzed using the Illumina Miseq platform with fungi-specific primers targeting the internal transcribed spacer 1 region of the large subunit rRNA gene. A total of 797,040 reads belonging to 1633 operational taxonomic units were observed. Of these, 1102 belonged to Ascomycota, 502 to Basidiomycota, 24 to Zygomycota, and 5 to Chytridiomycota. The dominant orders were Pleosporales (29.39%), Capnodiales (27.96%), Eurotiales (10.64%), and Hypocreales (9.01%). The dominant genera were Cladosporium, Alternaria, Fusarium, Penicillium, Sporisorium, and Aspergilus. Analysis of similarities revealed that both particulate matter sizes (R = 0.175, p = 0.001) and air quality levels (R = 0.076, p = 0.006) significantly affected the airborne fungal community composition. The relative abundance of many fungal genera was found to significantly differ among various PM types and air quality levels. Alternaria and Epicoccum were more abundant in total suspended particles samples, Aspergillus in heavy-haze days and PM2.5 samples, and Malassezia in PM2.5 samples and heavy-haze days. Canonical correspondence analysis and permutation tests showed that temperature (p < 0.01), NO2 (p < 0.01), PM10 (p < 0.01), SO2(p < 0.01), CO (p < 0.01), and relative humidity (p < 0.05) were significant factors that determine airborne fungal community composition. The results suggest that diverse airborne fungal communities are associated with particulate matters and may provide reliable data for studying the responses of human body to the increasing level of air pollution in Beijing. PMID:27148180

  19. The airborne laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven; Schall, Harold; Shattuck, Paul

    2007-05-01

    The Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the current program status.

  20. Metal reduction by spores of Desulfotomaculum reducens.

    PubMed

    Junier, Pilar; Frutschi, Manon; Wigginton, Nicholas S; Schofield, Eleanor J; Bargar, John R; Bernier-Latmani, Rizlan

    2009-12-01

    The bioremediation of uranium-contaminated sites is designed to stimulate the activity of microorganisms able to catalyze the reduction of soluble U(VI) to the less soluble mineral UO(2). U(VI) reduction does not necessarily support growth in previously studied bacteria, but it typically involves viable vegetative cells and the presence of an appropriate electron donor. We characterized U(VI) reduction by the sulfate-reducing bacterium Desulfotomaculum reducens strain MI-1 grown fermentatively on pyruvate and observed that spores were capable of U(VI) reduction. Hydrogen gas - a product of pyruvate fermentation - rather than pyruvate, served as the electron donor. The presence of spent growth medium was required for the process, suggesting that an unknown factor produced by the cells was necessary for reduction. Ultrafiltration of the spent medium followed by U(VI) reduction assays revealed that the factor's molecular size was below 3 kDa. Pre-reduced spent medium displayed short-term U(VI) reduction activity, suggesting that the missing factor may be an electron shuttle, but neither anthraquinone-2,6-disulfonic acid nor riboflavin rescued spore activity in fresh medium. Spores of D. reducens also reduced Fe(III)-citrate under experimental conditions similar to those for U(VI) reduction. This is the first report of a bacterium able to reduce metals while in a sporulated state and underscores the novel nature of the mechanism of metal reduction by strain MI-1. PMID:19601961

  1. Methyl Iodide Fumigation of Bacillus anthracis Spores.

    PubMed

    Sutton, Mark; Kane, Staci R; Wollard, Jessica R

    2015-09-01

    Fumigation techniques such as chlorine dioxide, vaporous hydrogen peroxide, and paraformaldehyde previously used to decontaminate items, rooms, and buildings following contamination with Bacillus anthracis spores are often incompatible with materials (e.g., porous surfaces, organics, and metals), causing damage or residue. Alternative fumigation with methyl bromide is subject to U.S. and international restrictions due to its ozone-depleting properties. Methyl iodide, however, does not pose a risk to the ozone layer and has previously been demonstrated as a fumigant for fungi, insects, and nematodes. Until now, methyl iodide has not been evaluated against Bacillus anthracis. Sterne strain Bacillus anthracis spores were subjected to methyl iodide fumigation at room temperature and at 550C. Efficacy was measured on a log-scale with a 6-log reduction in CFUs being considered successful compared to the U.S. Environmental Protection Agency biocide standard. Such efficacies were obtained after just one hour at 55 °C and after 12 hours at room temperature. No detrimental effects were observed on glassware, PTFE O-rings, or stainless steel. This is the first reported efficacy of methyl iodide in the reduction of Bacillus anthracis spore contamination at ambient and elevated temperatures. PMID:26502561

  2. Association of Fidaxomicin with C. difficile Spores: Effects of Persistence on Subsequent Spore Recovery, Outgrowth and Toxin Production

    PubMed Central

    Crowther, Grace S.; Ashwin, Helen; Longshaw, Chris M.; Wilcox, Mark H.

    2016-01-01

    Background We have previously shown that fidaxomicin instillation prevents spore recovery in an in-vitro gut model, whereas vancomycin does not. The reasons for this are unclear. Here, we have investigated persistence of fidaxomicin and vancomycin on C. difficile spores, and examined post-antibiotic exposure spore recovery, outgrowth and toxin production. Methods Prevalent UK C. difficile ribotypes (n = 10) were incubated with 200mg/L fidaxomicin, vancomycin or a non-antimicrobial containing control for 1 h in faecal filtrate or Phosphate Buffered Saline. Spores were washed three times with faecal filtrate or phosphate buffered saline, and residual spore-associated antimicrobial activity was determined by bioassay. For three ribotypes (027, 078, 015), antimicrobial-exposed, faecal filtrate-washed spores and controls were inoculated into broth. Viable vegetative and spore counts were enumerated on CCEYL agar. Percentage phase bright spores, phase dark spores and vegetative cells were enumerated by phase contrast microscopy at 0, 3, 6, 24 and 48 h post-inoculation. Toxin levels (24 and 48h) were determined by cell cytotoxicity assay. Results Fidaxomicin, but not vancomycin persisted on spores of all ribotypes following washing in saline (mean = 10.1mg/L; range = 4.0-14mg/L) and faecal filtrate (mean = 17.4mg/L; 8.4–22.1mg/L). Outgrowth and proliferation rates of vancomycin-exposed spores were similar to controls, whereas fidaxomicin-exposed spores showed no vegetative cell growth after 24 and 48 h. At 48h, toxin levels averaged 3.7 and 3.3 relative units (RU) in control and vancomycin-exposed samples, respectively, but were undetectable in fidaxomicin-exposed samples. Conclusion Fidaxomicin persists on C. difficile spores, whereas vancomycin does not. This persistence prevents subsequent growth and toxin production in vitro. This may have implications on spore viability, thereby impacting CDI recurrence and transmission rates. PMID:27556739

  3. Characterization of a novel single-stranded RNA virus, closely related to fusariviruses, infecting the plant pathogenic fungus Alternaria brassicicola.

    PubMed

    Zhong, Jie; Shang, Hong Hong; Zhu, Chuan Xia; Zhu, Jun Zi; Zhu, Hong Jian; Hu, Yan; Gao, Bi Da

    2016-06-01

    The alternaria blackspot of rapeseed is one of the most prominent diseases of rapeseed. It is caused by three species of the genus Alternaria: Alternaria brassicicola, Alternaria brassicae, and Alternaria raphanin. Here we report a novel positive-sense RNA virus from an A. brassicicola strain 817-14. The virus has a 6639 nucleotide (nt) long genome, excluding a poly (A)-tail, and was predicted to contain three putative open reading frames (ORF1, ORF2, and ORF3). The large ORF1 encoded a 174-kDa polyprotein (composed of 1522 amino acid residues) containing a conserved RNA-dependent RNA polymerase (RdRp) domain and a helicase domain. The other two smaller ORFs encoded polypeptides with unknown function. Homology search and phylogenetic analysis, based on the RdRp and helicase domains, suggest that this virus is related to and grouped with Sclerotinia sclerotiorum fusarivirus 1 (SsFV1), Rosellinia necatrix fusarivirus 1 (RnFV1), Fusarium graminearum virus-DK21 (FgV1), and Penicillium roqueforti RNA mycovirus 1 (PrRV1), all of which belong to a newly proposed family Fusariviridae. For this study, we designed the virus as "Alternaria brassicicola fusarivirus 1" (AbFV1). Virus elimination revealed that AbFV1 has no conspicuous impact on the biological properties of its host. PMID:26707921

  4. Development of a polymerase chain reaction-based assay for the detection of Alternaria fungal contamination in food products.

    PubMed

    Zur, G; Hallerman, E M; Sharf, R; Kashi, Y

    1999-10-01

    Alternaria sp. are important fungal contaminants of vegetable, fruit, and grain products, including Alternaria alternata, a contaminant of tomato products. To date, the Howard method, based on microscopic observation of fungal filaments, has been the standard examination for inspection of tomato products. We report development of a polymerase chain reaction (PCR)-based method for detection of Alternaria DNA. PCR primers were designed to anneal to the internal transcribed regions ITS1 and ITS2 of the 5.8S rRNA gene of Alternaria but not to other microbial or tomato DNA. We demonstrate use of the PCR assay to detect Alternaria DNA in experimentally infested and commercially obtained tomato sauce and tomato powder. Use of the PCR method offers a rapid and sensitive assay for the presence of Alternaria DNA in tomato products. The apparent breakdown of DNA in tomato sauce may limit the utility of the assay to freshly prepared products. The assay for tomato powder is not affected by storage time. PMID:10528725

  5. Characterisation of particulate matter on airborne pollen grains.

    PubMed

    Ribeiro, Helena; Guimarães, Fernanda; Duque, Laura; Noronha, Fernando; Abreu, Ilda

    2015-11-01

    A characterization of the physical-chemical composition of the atmospheric PM adsorbed to airborne pollen was performed. Airborne pollen was sampled using a Hirst-type volumetric spore sampler and observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image was taken of each pollen grain and EDS spectra were obtained for individually adsorbed particles. All images were analysed and the size parameters of the particles adsorbed to pollen was determined. The measured particles' equivalent diameter varied between 0.1 and 25.8 μm, mostly in the fine fraction. The dominant particulates identified were Si-rich, Organic-rich, SO-rich, Metals & Oxides and Cl-rich. Significant daily differences were observed in the physical-chemical characteristics of particles adsorbed to the airborne pollen wall. These differences were correlated with weather parameters and atmospheric PM concentration. Airborne pollen has the ability to adsorb fine particles that may enhance its allergenicity. PMID:26141127

  6. Chitinase-mediated inhibitory activity of Brassica transgenic on growth of Alternaria brassicae.

    PubMed

    Mondal, Kalyan K; Chatterjee, Subhas Chandra; Viswakarma, Navin; Bhattacharya, Ram Charan; Grover, Anita

    2003-09-01

    Chitinase, capable of degrading the cell walls of invading phytopathogenic fungi, plays an important role in plant defense response, particularly when this enzyme is overexpressed through genetic engineering. In the present study, Brassica plant (Brassica juncea L.) was transformed with chitinase gene tagged with an overexpressing promoter 35 S CaMV. The putative transgenics were assayed for their inhibitory activity against Alternaria brassicae, the inducer of Alternaria leaf spot of Brassica both in vitro and under polyhouse conditions. In in vitro fungal growth inhibition assays, chitinase inhibited the fungal colony size by 12-56% over the non-trangenic control. The bioassay under artificial epiphytotic conditions revealed the delay in the onset of disease as well as reduced lesion number and size in 35S-chitinase Brassica as compared to the untransformed control plants. PMID:14570264

  7. Four cases of dermatomycosis: superficial cutaneous infection by Alternaria or Bipolaris.

    PubMed

    Robb, Christopher W; Malouf, Peter J; Rapini, Ronald P

    2003-10-01

    Invasive dermal infections in immunosuppressed patients by a wide variety of opportunistic fungi are well described in the literature; however, superficial infections (dermatomycosis) are more rarely described. We report 4 cases of dermatomycosis by Alternaria or Bipolaris species. All but one of the patients had predisposing conditions including topical corticosteroid use, atopic or seborrheic dermatitis, and nail dystrophy. All 4 patients were otherwise immunocompetent. These cases represent some of the very few reports of Bipolaris in a primary stratum corneum infection and the first report of Bipolaris in an otherwise healthy person. We also describe what may be the first report of Bipolaris onychomycosis. All of our patients responded to topical or oral imidazole antifungal therapy. We discuss the significance of Alternaria and Bipolaris as contaminants or irrelevant organisms grown in some cultures of skin scrapings. PMID:14604084

  8. Degradation of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking.

    PubMed

    Siegel, David; Feist, Michael; Proske, Matthias; Koch, Matthias; Nehls, Irene

    2010-09-01

    The stability of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking was investigated by model experiments using a spiked wholemeal wheat flour matrix. For alternariol and alternariol monomethyl ether, but not for altenuene, degradation products, formed through a sequence of hydrolysis and decarboxylation, could be identified in pilot studies. The simultaneous quantification of alternariol, alternariol monomethyl ether, altenuene, and the degradation products was achieved by a newly developed high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) multimethod. The obtained quantitative data indicate that the Alternaria mycotoxins are barely degraded during wet baking, while significant degradation occurs upon dry baking, with the stability decreasing in the order alternariol monomethyl ether>alternariol>altenuene. The novel degradation products could be detected after the wet baking of flour spiked with alternariol and in a sample survey of 24 commercial cereal based baking products. PMID:20687560

  9. Genome sequence of a novel endornavirus from the phytopathogenic fungus Alternaria brassicicola.

    PubMed

    Shang, Hong-Hong; Zhong, Jie; Zhang, Ru-Jia; Chen, Chuan-Yuan; Gao, Bi-Da; Zhu, Hong-Jian

    2015-07-01

    In an effort to discover new mycoviruses from phytopathogenic fungi, a dsRNA molecule of 10,290 nt, resembling those associated with the viruses belonging to the family Endornaviridae, was isolated from Alternaria brassicicola, one of the causal agents of rapeseed black spot disease. Genome analysis revealed the presence of a single open reading frame coding for a polyprotein of 3400 aa containing conserved viral methyltransferase (MTR), viral RNA helicase 1 (Hel-1), and RNA-dependent RNA polymerase (RdRp) domains. In addition, a cysteine-rich region (CRR) with conserved CXCC motifs, shared among several endornaviruses, was also identified between the MTR and Hel-1 domains. Phylogenetic analysis based on the RdRp sequence strongly suggested that the virus infecting A. brassicicola should be considered a representative of a novel endornavirus species, and this virus was designated as Alternaria brassicicola endornavirus 1 (AbEV1). PMID:25951967

  10. Effect of electrical charges and fields on injury and viability of airborne bacteria.

    PubMed

    Mainelis, Gediminas; Górny, Rafał L; Reponen, Tiina; Trunov, Mikhaylo; Grinshpun, Sergey A; Baron, Paul; Yadav, Jagjit; Willeke, Klaus

    2002-07-20

    In this study, the effects of the electric charges and fields on the viability of airborne microorganisms were investigated. The electric charges of different magnitude and polarity were imparted on airborne microbial cells by a means of induction charging. The airborne microorganisms carrying different electric charge levels were then extracted by an electric mobility analyzer and collected using a microbial sampler. It was found that the viability of Pseudomonas fluorescens bacteria, used as a model for sensitive bacteria, carrying a net charge from 4100 negative to 30 positive elementary charges ranged between 40% and 60%; the viability of the cells carrying >2700 positive charges was below 1.5%. In contrast, the viability of the stress-resistant spores of Bacillus subtilis var. niger (used as simulant of anthrax-causing Bacillus anthracis spores when testing bioaerosol sensors in various studies), was not affected by the amount of electric charges on the spores. Because bacterial cells depend on their membrane potential for basic metabolic activities, drastic changes occurring in the membrane potential during aerosolization and the local electric fields induced by the imposed charges appeared to affect the sensitive cells' viability. These findings facilitate applications of electric charging for environmental control purposes involving sterilization of bacterial cells by imposing high electric charges on them. The findings from this study can also be used in the development of new bioaerosol sampling methods based on electrostatic principles. PMID:12115440

  11. Role of micronutrients in defense to white rust and Alternaria blight infecting Indian mustard.

    PubMed

    Rathi, A S; Singh, Dhiraj; Avtar, Ram; Kumar, Pawan

    2015-03-01

    Field experiments were carried out at Oilseeds Research Area of CCS Haryana Agricultural University, Hisar during rabi, 2008-09 to 2011-12 to find out the possible role of soil application of different micronutrients alone and in combinations in defense to white rust and Alternaria blight diseases in Indian mustard [Brassica juncea (L.) Czern & Coss.]. Among the sole application of micronutrients, minimum disease severity of both white rust (35.0%) and Alternaria blight (31.8%) was observed when S @ 40 kg ha in the form of Gypsum was applied as basal dose in the soil. When Gypsum was supplemented with Borax @10 kg ha(-1) or with ZnSO4 @15 kg ha(-1) the level of tolerance seems to be improved for both the diseases as compared to the sole treatment of each nutrient, i.e., ZnSO4 @ 15 kg/ha, Borax @ 10 kg ha' and Gypsum @ 250 kg ha(-1). Furthermore, minimum disease severity of both white rust (31.3 %) and Alternaria blight (26.3 %) was observed with soil application of ZnSO4 @ 15 kg ha(-1) + Borax @ 10 kg ha(-1) + Gypsum @250 kg ha(-1) as basal dose as compared to the severity of white rust (43.6%) and Alternaria blight (38.6%) in untreated check. Significant increase in seed yield (1612 kg ha(-1)) was also recorded in above mentioned treatment as compared to the yield (1337 kg ha(-1)) in untreated check. These findings will also be helpful in maintaining soil health and minimizing the losses due to both the fungal diseases for eco-friendly sustainability of Indian mustard. PMID:25895272

  12. Characterization and Pathogenicity of Alternaria burnsii from Seeds of Cucurbita maxima (Cucurbitaceae) in Bangladesh.

    PubMed

    Paul, Narayan Chandra; Deng, Jian Xin; Lee, Hyang Burm; Yu, Seung-Hun

    2015-12-01

    In the course of survey of endophytic fungi from Bangladesh pumpkin seeds in 2011~2012, two strains (CNU111042 and CNU111043) with similar colony characteristics were isolated and characterized by their morphology and by molecular phylogenetic analysis of the internal transcribed spacer, glyceraldehydes-3-phosphate dehydrogenase (gpd), and Alternaria allergen a1 (Alt a1) sequences. Phylogenetic analysis of all three sequences and their combined dataset revealed that the fungus formed a subclade within the A. alternata clade, matching A. burnsi and showing differences with its other closely related Alternaria species, such as A. longipes, A. tomato, and A. tomaticola. Long ellipsoid, obclavate or ovoid beakless conidia, shorter and thinner conidial size (16~60 [90] × 6.5~14 [~16] µm) distinguish this fungus from other related species. These isolates showed more transverse septation (2~11) and less longitudinal septation (0~3) than did other related species. Moreover, the isolate did not produce any diffusible pigment on media. Therefore, our results reveal that the newly recorded fungus from a new host, Cucurbita maxima, is Alternaria burnsii Uppal, Patel & Kamat. PMID:26839497

  13. PCR and real-time PCR assays to detect fungi of Alternaria alternata species.

    PubMed

    Kordalewska, Milena; Brillowska-Dąbrowska, Anna; Jagielski, Tomasz; Dworecka-Kaszak, Bożena

    2015-01-01

    Fungi of the Alternaria genus are mostly associated with allergic diseases. However, with a growing number of immunocompromised patients, these fungi, with A. alternata being the most prevalent one, are increasingly recognized as etiological agents of infections (phaeohyphomycoses) in humans. Nowadays, identification of Alternaria spp. requires their pure culture and is solely based on morphological criteria. Clinically, Alternaria infections may be indistinguishable from other fungal diseases. Therefore, a diagnostic result is often delayed or even not achieved at all. In this paper we present easy to perform and interpret PCR and real-time PCR assays enabling detection of A. alternata species. On the basis of alignment of β-tubulin gene sequences, A. alternata-specific primers were designed. DNA from fungal isolates, extracted in a two-step procedure, were used in PCR and real-time PCR assays followed by electrophoresis or melting temperature analysis, respectively. The assays specificity was confirmed, since positive results were obtained for all A. alternata isolates, and no positive results were obtained neither for other molds, dermatophytes, yeast-like fungi, nor human DNA. The assays developed here enable fast and unambiguous identification of A. alternata pathogens. PMID:26610309

  14. How the Necrotrophic Fungus Alternaria brassicicola Kills Plant Cells Remains an Enigma

    PubMed Central

    2015-01-01

    Alternaria species are mainly saprophytic fungi, but some are plant pathogens. Seven pathotypes of Alternaria alternata use secondary metabolites of host-specific toxins as pathogenicity factors. These toxins kill host cells prior to colonization. Genes associated with toxin synthesis reside on conditionally dispensable chromosomes, supporting the notion that pathogenicity might have been acquired several times by A. alternata. Alternaria brassicicola, however, seems to employ a different mechanism. Evidence on the use of host-specific toxins as pathogenicity factors remains tenuous, even after a diligent search aided by full-genome sequencing and efficient reverse-genetics approaches. Similarly, no individual genes encoding lipases or cell wall-degrading enzymes have been identified as strong virulence factors, although these enzymes have been considered important for fungal pathogenesis. This review describes our current understanding of toxins, lipases, and cell wall-degrading enzymes and their roles in the pathogenesis of A. brassicicola compared to those of other pathogenic fungi. It also describes a set of genes that affect pathogenesis in A. brassicicola. They are involved in various cellular functions that are likely important in most organisms and probably indirectly associated with pathogenesis. Deletion or disruption of these genes results in weakly virulent strains that appear to be sensitive to the defense mechanisms of host plants. Finally, this review discusses the implications of a recent discovery of three important transcription factors associated with pathogenesis and the putative downstream genes that they regulate. PMID:25681268

  15. Characterization and Pathogenicity of Alternaria burnsii from Seeds of Cucurbita maxima (Cucurbitaceae) in Bangladesh

    PubMed Central

    Paul, Narayan Chandra; Deng, Jian Xin

    2015-01-01

    In the course of survey of endophytic fungi from Bangladesh pumpkin seeds in 2011~2012, two strains (CNU111042 and CNU111043) with similar colony characteristics were isolated and characterized by their morphology and by molecular phylogenetic analysis of the internal transcribed spacer, glyceraldehydes-3-phosphate dehydrogenase (gpd), and Alternaria allergen a1 (Alt a1) sequences. Phylogenetic analysis of all three sequences and their combined dataset revealed that the fungus formed a subclade within the A. alternata clade, matching A. burnsi and showing differences with its other closely related Alternaria species, such as A. longipes, A. tomato, and A. tomaticola. Long ellipsoid, obclavate or ovoid beakless conidia, shorter and thinner conidial size (16~60 [90] × 6.5~14 [~16] µm) distinguish this fungus from other related species. These isolates showed more transverse septation (2~11) and less longitudinal septation (0~3) than did other related species. Moreover, the isolate did not produce any diffusible pigment on media. Therefore, our results reveal that the newly recorded fungus from a new host, Cucurbita maxima, is Alternaria burnsii Uppal, Patel & Kamat. PMID:26839497

  16. Human eosinophil innate response to Alternaria fungus through protease-activated receptor-2.

    PubMed

    Matsuwaki, Yoshinori; Wada, Kota; Moriyama, Hiroshi; Kita, Hirohito

    2011-01-01

    Eosinophils are multifunctional leukocytes implicated in the pathogenesis of allergic diseases. An association between eosinophilic inflammation and infection or colonization by fungi has also been long recognized. However, the mechanisms underlying how eosinophils are activated and how they release proinflammatory and immunomodulatory mediators such as major basic protein (MBP) and eosinophil-derived neurotoxin remain largely unknown. We used a fungus, i.e. Alternaria, as a model microbe relevant to human asthma and chronic rhinosinusitis (CRS) to investigate the molecular mechanisms involved in the immune recognition of ubiquitous environmental allergens. Human eosinophils are activated by live Alternaria alternata organisms, release their granule proteins, and kill the fungi. Eosinophils, but not neutrophils, respond to secreted products from A. alternata. We found that eosinophils are equipped with innate cellular activation machinery that responds to an extracellular aspartate protease secreted by Alternaria. Aspartate protease activation of protease-activated receptor (PAR)-2 probably involves a novel mechanism different from that for serine protease activation of PAR-2. Thus, human eosinophils may recognize certain danger signals or virulence factors produced by fungi and provoke inflammatory responses against these organisms. Dysregulation of such an innate immune mechanism may be involved in the pathophysiology of certain human inflammatory diseases, including asthma and CRS. PMID:21646807

  17. Production of the Allergenic Protein Alt a 1 by Alternaria Isolates from Working Environments

    PubMed Central

    Skóra, Justyna; Otlewska, Anna; Gutarowska, Beata; Leszczyńska, Joanna; Majak, Iwona; Stępień, Łukasz

    2015-01-01

    The aim of the study was to evaluate the ability of Alternaria isolates from workplaces to produce Alt a 1 allergenic protein, and to analyze whether technical materials (cellulose, compost, leather) present within the working environment stimulate or inhibit Alt a 1 production (ELISA test). Studies included identification of the isolated molds by nucleotide sequences analyzing of the ITS1/ITS2 regions, actin, calmodulin and Alt a 1 genes. It has been shown that Alternaria molds are significant part of microbiocenosis in the archive, museum, library, composting plant and tannery (14%–16% frequency in the air). The presence of the gene encoding the Alt a 1 protein has been detected for the strains: Alternaria alternata, A. lini, A. limoniasperae A. nobilis and A. tenuissima. Environmental strains produced Alt a 1 at higher concentrations (1.103–6.528 ng/mL) than a ATCC strain (0.551–0.975 ng/mL). It has been shown that the homogenization of the mycelium and the use of ultrafiltration allow a considerable increase of Alt a 1 concentration. Variations in the production of Alt a 1 protein, depend on the strain and extraction methods. These studies revealed no impact of the technical material from the workplaces on the production of Alt a 1 protein. PMID:25689994

  18. Production of the allergenic protein Alt a 1 by Alternaria isolates from working environments.

    PubMed

    Skóra, Justyna; Otlewska, Anna; Gutarowska, Beata; Leszczyńska, Joanna; Majak, Iwona; Stępień, Łukasz

    2015-02-01

    The aim of the study was to evaluate the ability of Alternaria isolates from workplaces to produce Alt a 1 allergenic protein, and to analyze whether technical materials (cellulose, compost, leather) present within the working environment stimulate or inhibit Alt a 1 production (ELISA test). Studies included identification of the isolated molds by nucleotide sequences analyzing of the ITS1/ITS2 regions, actin, calmodulin and Alt a 1 genes. It has been shown that Alternaria molds are significant part of microbiocenosis in the archive, museum, library, composting plant and tannery (14%-16% frequency in the air). The presence of the gene encoding the Alt a 1 protein has been detected for the strains: Alternaria alternata, A. lini, A. limoniasperae A. nobilis and A. tenuissima. Environmental strains produced Alt a 1 at higher concentrations (1.103-6.528 ng/mL) than a ATCC strain (0.551-0.975 ng/mL). It has been shown that the homogenization of the mycelium and the use of ultrafiltration allow a considerable increase of Alt a 1 concentration. Variations in the production of Alt a 1 protein, depend on the strain and extraction methods. These studies revealed no impact of the technical material from the workplaces on the production of Alt a 1 protein. PMID:25689994

  19. Microbiological efficacy of superheated steam. I. Communication: results with spores of Bacillus subtilis and Bacillus stearothermophilus and with spore earth.

    PubMed

    Spicher, G; Peters, J; Borchers, U

    1999-02-01

    For the spores of Bacillus subtilis and Bacillus stearothermophilus as well as for spore earth (acc. DIN 58,946 Part 4 of August 1982), the dependence of resistance on the superheating of the steam used to kill germs was determined. A material (glass fibre fleece) was used as the germ carrier which does not superheat on contact with steam. The temperature of the saturated steam was 100 degrees C (B. subtilis) and 120 degrees C (B. stearothermophilus and spore earth). The yardstick for the resistance of the spores or bioindicators was the exposure period of the saturated or superheated steam at which 50% of the treated test objects no longer showed any viable test germs. The spores of Bacillus subtilis were far more sensitive to superheating of steam and reacted far more than the spores of Bacillus stearothermophilus and the germs in the spore earth. When superheating by 4 Kelvin the spores of Bacillus subtilis were approximately 2.5 times more resistant than they were to saturated steam. The resistance of Bacillus stearothermophilus and spore earth was only slightly higher up to superheating by 10 Kelvin. The spores of Bacillus subtilis had the highest resistance during superheating by 29 Kelvin; they were 119 times more resistant than they were to saturated steam. The resistance maximum of the spores of Bacillus stearothermophilus was at an superheating by around 22 Kelvin. However, the spores were only 4.1 times more resistant than they were to saturated steam. When using steam to kill germs, we must expect superheated steam. This raises the question whether the spores of Bacillus stearothermophilus, with their weaker reaction to the superheating of steam, are suitable as test germs for sterilisation with steam in all cases. PMID:10084207

  20. Discrimination of airborne material particles from light scattering (TAOS) patterns

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni F.; Pan, Yong-Le; Videen, Gorden; Aptowicz, Kevin B.; Chang, Richard K.

    2013-05-01

    Two-dimensional angle-resolved optical scattering (TAOS) is an experimental method which collects the intensity pattern of monochromatic light scattered by a single, micron-sized airborne particle. In general, the interpretation of these patterns and the retrieval of the particle refractive index, shape or size alone, are difficult problems. The solution proposed herewith relies on a learning machine (LM): rather than identifying airborne particles from their scattering patterns, TAOS patterns themselves are classified. The LM consists of two interacting modules: a feature extraction module and a linear classifier. Feature extraction relies on spectrum enhancement, which includes the discrete cosine Fourier transform and non-linear operations. Linear classification relies on multivariate statistical analysis. Interaction enables supervised training of the LM. The application described in this article aims at discriminating the TAOS patterns of single bacterial spores (Bacillus subtilis) from patterns of atmospheric aerosol and diesel soot particles. The latter are known to interfere with the detection of bacterial spores. Classification has been applied to a data set with more than 3000 TAOS patterns from various materials. Some classification experiments are described, where the size of training sets has been varied as well as many other parameters which control the classifier. By assuming all training and recognition patterns to come from the respective reference materials only, the most satisfactory classification result corresponds to ≍ 20% false negatives from Bacillus subtilis particles and <= 11% false positives from environmental and diesel particles.

  1. A study of Ganoderma lucidum spores by FTIR microspectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Chen, Xianliang; Qi, Zeming; Liu, Xingcun; Li, Weizu; Wang, Shengyi

    2012-06-01

    In order to obtain unique information of Ganoderma lucidum spores, FTIR microspectroscopy was used to study G. lucidum spores from Anhui Province (A), Liaoning Province (B) and Shangdong Province (C) of China. IR micro-spectra were acquired with high-resolution and well-reproducibility. The IR spectra of G. lucidum spores from different areas were similar and mainly made up of the absorption bands of polysaccharide, sterols, proteins, fatty acids, etc. The results of curve fitting indicated the protein secondary structures were dissimilar among the above G. lucidum spores. To identify G. lucidum spores from different areas, the H1078/H1640 value might be a potentially useful factor, furthermore FTIR microspectroscopy could realize this identification efficiently with the help of hierarchical cluster analysis. The result indicates FTIR microspectroscopy is an efficient tool for identification of G. lucidum spores from different areas. The result also suggests FTIR microspectroscopy is a potentially useful tool for the study of TCM.

  2. Assay for Spore Wall Integrity Using a Yeast Predator.

    PubMed

    Okada, Hiroki; Neiman, Aaron M; Ohya, Yoshikazu

    2016-01-01

    During the budding yeast life cycle, a starved diploid cell undergoes meiosis followed by production of four haploid spores, each surrounded by a spore wall. The wall allows the spores to survive in harsh environments until conditions improve. Spores are also more resistant than vegetative cells to treatments such as ether vapor, glucanases, heat shock, high salt concentrations, and exposure to high or low pH, but the relevance of these treatments to natural environmental stresses remains unclear. This protocol describes a method for assaying the yeast spore wall under natural environmental conditions by quantifying the survival of yeast spores that have passed through the digestive system of a yeast predator, the fruit fly. PMID:27480715

  3. Application of gaseous ozone for inactivation of Bacillus subtilis spores.

    PubMed

    Aydogan, Ahmet; Gurol, Mirat D

    2006-02-01

    The effectiveness of gaseous ozone (O3) as a disinfectant was tested on Bacillus subtilis spores, which share the same physiological characteristics as Bacillus anthracis spores that cause the anthrax disease. Spores dried on surfaces of different carrier material were exposed to O3 gas in the range of 500-5000 ppm and at relative humidity (RH) of 70-95%. Gaseous O3 was found to be very effective against the B. subtilis spores, and at O3 concentrations as low as 3 mg/L (1500 ppm), approximately 3-log inactivation was obtained within 4 hr of exposure. The inactivation curves consisted of a short lag phase followed by an exponential decrease in the number of surviving spores. Prehydration of the bacterial spores has eliminated the initial lag phase. The inactivation rate increased with increasing O3 concentration but not >3 mg/L. The inactivation rate also increased with increase in RH. Different survival curves were obtained for various surfaces used to carry spores. Inactivation rates of spores on glass, a vinyl floor tile, and office paper were nearly the same. Whereas cut pile carpet and hardwood flooring surfaces resulted in much lower inactivation rates, another type of carpet (loop pile) showed significant enhancement in the inactivation of the spores. PMID:16568801

  4. Quantitative and sensitive RNA based detection of Bacillus spores

    PubMed Central

    Osmekhina, Ekaterina; Shvetsova, Antonina; Ruottinen, Maria; Neubauer, Peter

    2014-01-01

    The fast and reliable detection of bacterial spores is of great importance and still remains a challenge. Here we describe a direct RNA-based diagnostic method for the specific detection of viable bacterial spores which does not depends on an enzymatic amplification step and therefore is directly appropriate for quantification. The procedure includes the following steps: (i) heat activation of spores, (ii) germination and enrichment cultivation, (iii) cell lysis, and (iv) analysis of 16S rRNA in crude cell lysates using a sandwich hybridization assay. The sensitivity of the method is dependent on the cultivation time and the detection limit; it is possible to detect 10 spores per ml when the RNA analysis is performed after 6 h of enrichment cultivation. At spore concentrations above 106 spores per ml the cultivation time can be shortened to 30 min. Total analysis times are in the range of 2–8 h depending on the spore concentration in samples. The developed procedure is optimized at the example of Bacillus subtilis spores but should be applicable to other organisms. The new method can easily be modified for other target RNAs and is suitable for specific detection of spores from known groups of organisms. PMID:24653718

  5. Total airborne mold particle sampling: evaluation of sample collection, preparation and counting procedures, and collection devices.

    PubMed

    Godish, Diana; Godish, Thad

    2008-02-01

    This study was conducted to evaluate (i) procedures used to collect, prepare, and count total airborne mold spore/particle concentrations, and (ii) the relative field performance of three commercially available total airborne mold spore/particle sampling devices. Differences between factory and laboratory airflow calibration values of axial fan-driven sampling instruments (used in the study) indicated a need for laboratory calibration using a mass flow meter to ensure that sample results were accurately calculated. An aniline blue-amended Calberla's solution adjusted to a pH of 4.2-4.4 provided good sample mounting/counting results using Dow Corning high vacuum grease, Dow Corning 280A adhesive, and Dow Corning 316 silicone release spray for samples collected using mini-Burkard and Allergenco samplers. Count variability among analysts was most pronounced in 5% counts of relatively low mold particle deposition density samples and trended downward with increased count percentage and particle deposition density. No significant differences were observed among means of 5, 10, and 20% counts and among analysts; a significant interaction effect was observed between analysts' counts and particle deposition densities. Significantly higher mini-Burkard and Air-O-Cell total mold spore/particle counts for 600x vs. 400x (1.9 and 2.3 x higher, respectively), 1000x vs. 600x (1.9 and 2.2 x higher, respectively) and 1000x vs. 400x (3.6 and 4.6 x higher, respectively) comparisons indicated that 1000x magnification counts best quantified total airborne mold spore/particles using light microscopy, and that lower magnification counts may result in unacceptable underreporting of airborne mold spore/particle concentrations. Modest but significantly higher (1.2x) total mold spore concentrations were observed with Allergenco vs. mini-Burkard samples collected in co-located, concurrently operated sampler studies; moderate but significantly higher mini-Burkard count values (1.4x) were

  6. Spore-Forming Bacteria that Resist Sterilization

    NASA Technical Reports Server (NTRS)

    LaDuc, Myron; Venkateswaran, Kasthuri

    2003-01-01

    A report presents a phenotypic and genotypic characterization of a bacterial species that has been found to be of the genus Bacillus and has been tentatively named B. odysseensis because it was isolated from surfaces of the Mars Odyssey spacecraft as part of continuing research on techniques for sterilizing spacecraft to prevent contamination of remote planets by terrestrial species. B. odysseensis is a Gram-positive, facultatively anaerobic, rod-shaped bacterium that forms round spores. The exosporium has been conjectured to play a role in the elevated resistance to sterilization. Research on the exosporium is proposed as a path toward improved means of sterilization, medical treatment, and prevention of biofouling.

  7. The Airborne Laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven E.

    2002-09-01

    The US Air Force Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success.

  8. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Specifications and preliminary design of an Airborne Oceanographic Lidar (AOL) system, which is to be constructed for installation and used on a NASA Wallops Flight Center (WFC) C-54 research aircraft, are reported. The AOL system is to provide an airborne facility for use by various government agencies to demonstrate the utility and practicality of hardware of this type in the wide area collection of oceanographic data on an operational basis. System measurement and performance requirements are presented, followed by a description of the conceptual system approach and the considerations attendant to its development. System performance calculations are addressed, and the system specifications and preliminary design are presented and discussed.

  9. NASA Airborne Lidar July 1991

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar July 1991 Data from the 1991 NASA Langley Airborne Lidar flights following the eruption of Pinatubo in July ... and Osborn [1992a, 1992b]. Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  10. NASA Airborne Lidar May 1992

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar May 1992 An airborne Nd:YAG (532 nm) lidar was operated by the NASA Langley Research Center about a year following the June 1991 eruption of ... Osborn [1992a, 1992b].  Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  11. Contamination of healthcare workers' hands with bacterial spores.

    PubMed

    Sasahara, Teppei; Ae, Ryusuke; Watanabe, Michiyo; Kimura, Yumiko; Yonekawa, Chikara; Hayashi, Shunji; Morisawa, Yuji

    2016-08-01

    Clostridium species and Bacillus spp. are spore-forming bacteria that cause hospital infections. The spores from these bacteria are transmitted from patient to patient via healthcare workers' hands. Although alcohol-based hand rubbing is an important hand hygiene practice, it is ineffective against bacterial spores. Therefore, healthcare workers should wash their hands with soap when they are contaminated with spores. However, the extent of health care worker hand contamination remains unclear. The aim of this study is to determine the level of bacterial spore contamination on healthcare workers' hands. The hands of 71 healthcare workers were evaluated for bacterial spore contamination. Spores attached to subject's hands were quantitatively examined after 9 working hours. The relationship between bacterial spore contamination and hand hygiene behaviors was also analyzed. Bacterial spores were detected on the hands of 54 subjects (76.1%). The mean number of spores detected was 468.3 CFU/hand (maximum: 3300 CFU/hand). Thirty-seven (52.1%) and 36 (50.7%) subjects were contaminated with Bacillus subtilis and Bacillus cereus, respectively. Nineteen subjects (26.8%) were contaminated with both Bacillus species. Clostridium difficile was detected on only one subject's hands. There was a significant negative correlation between the hand contamination level and the frequency of handwashing (r = -0.44, P < 0.01) and a significant positive correlation between the hand contamination level and the elapsed time since last handwashing (r = 0.34, P < 0.01). Healthcare workers' hands may be frequently contaminated with bacterial spores due to insufficient handwashing during daily patient care. PMID:27236515

  12. Model simulations of fungal spore distribution over the Indian region

    NASA Astrophysics Data System (ADS)

    Ansari, Tabish U.; Valsan, Aswathy E.; Ojha, N.; Ravikrishna, R.; Narasimhan, Balaji; Gunthe, Sachin S.

    2015-12-01

    Fungal spores play important role in the health of humans, animals, and plants by constituting a class of the primary biological aerosol particles (PBAPs). Additionally, these could mediate the hydrological cycle by acting as nuclei for ice and cloud formation (IN and CCN respectively). Various processes in the biosphere and the variations in the meteorological conditions control the releasing mechanism of spores through active wet and dry discharge. In the present paper, we simulate the concentration of fungal spores over the Indian region during three distinct meteorological seasons by combining a numerical model (WRF-Chem) with the fungal spore emissions based on land-use type. Maiden high-resolution regional simulations revealed large spatial gradient and strong seasonal dependence in the concentration of fungal spores over the Indian region. The fungal spore concentrations are found to be the highest during winter (0-70 μg m-3 in December), moderately higher during summer (0-35 μg m-3 in May) and lowest during the monsoon (0-25 μg m-3 in July). The elevated concentrations during winter are attributed to the shallower boundary layer trapping the emitted fungal spores in smaller volume. In contrast, the deeper boundary layer mixing in May and stronger monsoonal-convection in July distribute the fungal spores throughout the lower troposphere (∼5 km). We suggest that the higher fungal spore concentrations during winter could have potential health impacts. While, stronger vertical mixing could enable fungal spores to influence the cloud formation during summer and monsoon. Our study provides the first information about the distribution and seasonal variation of fungal spores over the densely populated and observationally sparse Indian region.

  13. Effect of Lysozyme on Ionic Forms of Spores of Clostridium perfringens Type A

    PubMed Central

    Ando, Yoshiaki

    1975-01-01

    H spores of Clostridium perfringens type A (two strains) were more sensitive to germination by lysozyme than native spores. Resistance to lysozyme of H spores was restored by calcium loading. PMID:236284

  14. Comparison of background levels of culturable fungal spore concentrations in indoor and outdoor air in southeastern Austria

    NASA Astrophysics Data System (ADS)

    Haas, D.; Habib, J.; Luxner, J.; Galler, H.; Zarfel, G.; Schlacher, R.; Friedl, H.; Reinthaler, F. F.

    2014-12-01

    Background concentrations of airborne fungi are indispensable criteria for an assessment of fungal concentrations indoors and in the ambient air. The goal of this study was to define the natural background values of culturable fungal spore concentrations as reference values for the assessment of moldy buildings. The concentrations of culturable fungi were determined outdoors as well as indoors in 185 dwellings without visible mold, obvious moisture problems or musty odor. Samples were collected using the MAS-100® microbiological air sampler. The study shows a characteristic seasonal influence on the background levels of Cladosporium, Penicillium and Aspergillus. Cladosporium sp. had a strong outdoor presence, whereas Aspergillus sp. and Penicillium sp. were typical indoor fungi. For the region of Styria, the median outdoor concentrations are between 100 and 940 cfu/m³ for culturable xerophilic fungi in the course of the year. Indoors, median background levels are between 180 and 420 cfu/m³ for xerophilic fungi. The I/O ratios of the airborne fungal spore concentrations were between 0.2 and 2.0. For the assessment of indoor and outdoor air samples the dominant genera Cladosporium, Penicillium and Aspergillus should receive special consideration.

  15. Airborne antenna pattern calculations

    NASA Technical Reports Server (NTRS)

    Knerr, T. J.; Schaffner, P. R.; Mielke, R. R.; Gilreath, M. C.

    1980-01-01

    A procedure for numerically calculating radiation patterns of fuselage-mounted airborne antennas using the Volumetric Pattern Analysis Program is presented. Special attention is given to aircraft modeling. An actual case study involving a large commercial aircraft is included to illustrate the analysis procedure.

  16. Recognizing Airborne Hazards.

    ERIC Educational Resources Information Center

    Schneider, Christian M.

    1990-01-01

    The heating, ventilating, and air conditioning (HVAC) systems in older buildings often do not adequately handle air-borne contaminants. Outlines a three-stage Indoor Air Quality (IAQ) assessment and describes a case in point at a Pittsburgh, Pennsylvania, school. (MLF)

  17. Airborne Fraunhofer Line Discriminator

    NASA Technical Reports Server (NTRS)

    Gabriel, F. C.; Markle, D. A.

    1969-01-01

    Airborne Fraunhofer Line Discriminator enables prospecting for fluorescent materials, hydrography with fluorescent dyes, and plant studies based on fluorescence of chlorophyll. Optical unit design is the coincidence of Fraunhofer lines in the solar spectrum occurring at the characteristic wavelengths of some fluorescent materials.

  18. Airborne Remote Sensing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA imaging technology has provided the basis for a commercial agricultural reconnaissance service. AG-RECON furnishes information from airborne sensors, aerial photographs and satellite and ground databases to farmers, foresters, geologists, etc. This service produces color "maps" of Earth conditions, which enable clients to detect crop color changes or temperature changes that may indicate fire damage or pest stress problems.

  19. Protoplast dehydration correlated with heat resistance of bacterial spores.

    PubMed Central

    Nakashio, S; Gerhardt, P

    1985-01-01

    Water content of the protoplast in situ within the fully hydrated dormant bacterial spore was quantified by use of a spore in which the complex of coat and outer (pericortex) membrane was genetically defective or chemically removed, as evidenced by susceptibility of the cortex to lysozyme and by permeability of the periprotoplast integument to glucose. Water content was determined by equilibrium permeability measurement with 3H-labeled water (confirmed by gravimetric measurement) for the entire spore, with 14C-labeled glucose for the integument outside the inner (pericytoplasm) membrane, and by the difference for the protoplast. The method was applied to lysozyme-sensitive spores of Bacillus stearothermophilus, B. subtilis, B. cereus, B. thuringiensis, and B. megaterium (four types). Comparable lysozyme-resistant spores, in which the outer membrane functioned as the primary permeability barrier to glucose, were employed as controls. Heat resistances were expressed as D100 values. Protoplast water content of the lysozyme-sensitive spore types correlated with heat resistance exponentially in two distinct clusters, with the four B. megaterium types in one alignment, and with the four other species types in another. Protoplast water contents of the B. megaterium spore types were sufficiently low (26 to 29%, based on wet protoplast weight) to account almost entirely for their lesser heat resistance. Corresponding values of the other species types were similar or higher (30 to 55%), indicating that these spores depended on factors additional to protoplast dehydration for their much greater heat resistance. PMID:3988704

  20. The Role of the Electrostatic Force in Spore Adhesion

    SciTech Connect

    Chung, Eunhyea; Yiacoumi, Sotira; Lee, Ida; Tsouris, Costas

    2010-01-01

    Electrostatic force is investigated as one of the components of the adhesion force between Bacillus thuringiensis (Bt) spores and planar surfaces. The surface potentials of a Bt spore and a mica surface are experimentally obtained using a combined atomic force microscopy (AFM)-scanning surface potential microscopy technique. On the basis of experimental information, the surface charge density of the spores is estimated at 0.03 {micro}C/cm{sup 2} at 20% relative humidity and decreases with increasing humidity. The Coulombic force is introduced for the spore-mica system (both charged, nonconductive surfaces), and an electrostatic image force is introduced to the spore-gold system because gold is electrically conductive. The Coulombic force for spore-mica is repulsive because the components are similarly charged, while the image force for the spore-gold system is attractive. The magnitude of both forces decreases with increasing humidity. The electrostatic forces are added to other force components, e.g., van der Waals and capillary forces, to obtain the adhesion force for each system. The adhesion forces measured by AFM are compared to the estimated values. It is shown that the electrostatic (Coulombic and image) forces play a significant role in the adhesion force between spores and planar surfaces.

  1. Comparison of hand hygiene procedures for removing Bacillus cereus spores.

    PubMed

    Sasahara, Teppei; Hayashi, Shunji; Hosoda, Kouichi; Morisawa, Yuji; Hirai, Yoshikazu

    2014-01-01

    Bacillus cereus is a spore-forming bacterium. B. cereus occasionally causes nosocomial infections, in which hand contamination with the spores plays an important role. Therefore, hand hygiene is the most important practice for controlling nosocomial B. cereus infections. This study aimed to determine the appropriate hand hygiene procedure for removing B. cereus spores. Thirty volunteers' hands were experimentally contaminated with B. cereus spores, after which they performed 6 different hand hygiene procedures. We compared the efficacy of the procedures in removing the spores from hands. The alcohol-based hand-rubbing procedures scarcely removed them. The soap washing procedures reduced the number of spores by more than 2 log10. Extending the washing time increased the spore-removing efficacy of the washing procedures. There was no significant difference in efficacy between the use of plain soap and antiseptic soap. Handwashing with soap is appropriate for removing B. cereus spores from hands. Alcohol-based hand-rubbing is not effective. PMID:25252644

  2. Factors influencing Saprolegnia spp. spore numbers in Norwegian salmon hatcheries.

    PubMed

    Thoen, E; Evensen, Ø; Skaar, I

    2016-06-01

    A quantitative survey of Saprolegnia spp. in the water systems of Norwegian salmon hatcheries was performed. Water samples from 14 salmon hatcheries distributed along the Norwegian coastline were collected during final incubation in the hatcheries. Samples of inlet and effluent water were analyzed to estimate Saprolegnia propagule numbers. Saprolegnia spores were found in all samples at variable abundance. Number of spores retrieved varied from 50 to 3200 L(-1) in inlet water and from 30 to >5000 L(-1) in effluent water. A significant elevation of spore levels in effluent water compared to inlet water was detected. The estimated spore levels were related to recorded managerial and environmental parameters, and the number of spores in inlet water and temperature was the factor having most influence on the spore concentration in the incubation units (effluent water). Further, the relative impact of spore concentration on hatching rates was investigated by correlation analysis. From this was found that even high spore counts did not impact significantly on hatching success. PMID:26123005

  3. Binding Affinity of Glycoconjugates to BACILLUS Spores and Toxins

    NASA Astrophysics Data System (ADS)

    Rasol, Aveen; Eassa, Souzan; Tarasenko, Olga

    2010-04-01

    Early recognition of Bacillus cereus group species is important since they can cause food-borne illnesses and deadly diseases in humans. Glycoconjugates (GCs) are carbohydrates covalently linked to non-sugar moieties including lipids, proteins or other entities. GCs are involved in recognition and signaling processes intrinsic to biochemical functions in cells. They also stimulate cell-cell adhesion and subsequent recognition and activation of receptors. We have demonstrated that GCs are involved in Bacillus cereus spore recognition. In the present study, we have investigated whether GCs possess the ability to bind and recognize B. cereus spores and Bacillus anthracis recombinant single toxins (sTX) and complex toxins (cTX). The affinity of GCs to spores + sTX and spores + cTX toxins was studied in the binding essay. Our results demonstrated that GC9 and GC10 were able to selectively bind to B. cereus spores and B. anthracis toxins. Different binding affinities for GCs were found toward Bacillus cereus spores + sTX and spores + cTX. Dilution of GCs does not impede the recognition and binding. Developed method provides a tool for simultaneous recognition and targeting of spores, bacteria toxins, and/or other entities.

  4. 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.

  5. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  6. Elemental characterization of the airborne pollen surface using Electron Probe Microanalysis (EPMA)

    NASA Astrophysics Data System (ADS)

    Duque, Laura; Guimarães, Fernanda; Ribeiro, Helena; Sousa, Raquel; Abreu, Ilda

    2013-08-01

    Recent worldwide increase in pollinoses has been attributed to the synergy between pollen and pollutants. We used EPMA for the elemental characterization of the airborne pollen surface in order to find out what occurs to the wall of pollen grains when they are together with other atmospheric pollutants. Analyses were performed both to airborne pollen and to pollen that was collected from Acer spp., Platanus spp. and Pinus spp. trees. Airborne samples were assembled using a Hirst-type volumetric spore sampler set in the coastal city of Porto, Portugal. Airborne pollen samples showed major elemental differences when compared to the control pollen sample of the same species, namely in the amounts of Cl, Na and Mg, which very significantly increased on airborne samples, revealing an important influence of the ocean. Mineral dust also contributed to modify the pollen surface, by increasing Si contents on Acer spp. and Platanus spp. airborne pollen. Our results revealed consistent positive effects of the relative humidity and the precipitation in the increase of Cl, Na and Mg relative amounts on the pollen surface. This study shows that pollen grains have the ability to adsorb and/or absorb other materials, which may contribute to enhance pollen's harmful effects on people's health.

  7. Surface sampling methods for Bacillus anthracis spore contamination.

    PubMed

    Sanderson, Wayne T; Hein, Misty J; Taylor, Lauralynn; Curwin, Brian D; Kinnes, Gregory M; Seitz, Teresa A; Popovic, Tanja; Holmes, Harvey T; Kellum, Molly E; McAllister, Sigrid K; Whaley, David N; Tupin, Edward A; Walker, Timothy; Freed, Jennifer A; Small, Dorothy S; Klusaritz, Brian; Bridges, John H

    2002-10-01

    During an investigation conducted December 17-20, 2001, we collected environmental samples from a U.S. postal facility in Washington, D.C., known to be extensively contaminated with Bacillus anthracis spores. Because methods for collecting and analyzing B. anthracis spores have not yet been validated, our objective was to compare the relative effectiveness of sampling methods used for collecting spores from contaminated surfaces. Comparison of wipe, wet and dry swab, and HEPA vacuum sock samples on nonporous surfaces indicated good agreement between results with HEPA vacuum and wipe samples. However, results from HEPA vacuum sock and wipe samples agreed poorly with the swab samples. Dry swabs failed to detect spores >75% of the time when they were detected by wipe and HEPA vacuum samples. Wipe samples collected after HEPA vacuum samples and HEPA vacuum samples collected after wipe samples indicated that neither method completely removed spores from the sampled surfaces. PMID:12396930

  8. Quantification of Spore-forming Bacteria Carried by Dust Particles

    NASA Technical Reports Server (NTRS)

    Lin, Ying; Cholakian, Tanya; Gao, Wenming; Osman, Shariff; Barengoltz, Jack

    2006-01-01

    In order to establish a biological contamination transport model for predicting the cross contamination risk during spacecraft assembly and upon landing on Mars, it is important to understand the relationship between spore-forming bacteria and their carrier particles. We conducted air and surface sampling in indoor, outdoor, and cleanroom environments to determine the ratio of spore forming bacteria to their dust particle carriers of different sizes. The number of spore forming bacteria was determined from various size groups of particles in a given environment. Our data also confirms the existence of multiple spores on a single particle and spore clumps. This study will help in developing a better bio-contamination transport model, which in turn will help in determining forward contamination risks for future missions.

  9. Bacillus atrophaeus Outer Spore Coat Assembly and Ultrastructure

    SciTech Connect

    Plomp, M; Leighton, T J; Wheeler, K E; Pitesky, M E; Malkin, A J

    2005-11-21

    Our previous atomic force microscopy (AFM) studies successfully visualized native Bacillus atrophaeus spore coat ultrastructure and surface morphology. We have shown that the outer spore coat surface is formed by a crystalline array of {approx}11 nm thick rodlets, having a periodicity of {approx}8 nm. We present here further AFM ultrastructural investigations of air-dried and fully hydrated spore surface architecture. In the rodlet layer, planar and point defects, as well as domain boundaries, similar to those described for inorganic and macromolecular crystals, were identified. For several Bacillus species, rodlet structure assembly and architectural variation appear to be a consequence of species-specific nucleation and crystallization mechanisms that regulate the formation of the outer spore coat. We propose a unifying mechanism for nucleation and self-assembly of this crystalline layer on the outer spore coat surface.

  10. Bioherbicidal activity from washed spores of Myrothecium verrucaria.

    PubMed

    Weaver, Mark A; Boyette, C Douglas; Hoagland, Robert E

    2012-05-01

    The fungal plant pathogen, Myrothecium verrucaria, is highly virulent to several important weed species and has potential utility as a bioherbicide. However the production of macrocyclic trichothecene mycotoxins by this fungus presents significant safety concerns. It was discovered that trichothecenes are removed from M. verrucaria spores by repeated washes with water. These washed spores retained bioherbicidal efficacy against kudzu when tested in field trials and on sicklepod when tested under greenhouse conditions. Changes in the growth medium combined with washing spores with water resulted in greater than 95% reduction in roridin A and verrucarin A. Washing spores reduced trichothecene concentrations in spore preparations with no significant effect on plant biomass reduction, thus demonstrating the possibility of M. verrucaria formulations with improved safety to researchers, producers and applicators. PMID:22806015

  11. Dual effects of single-walled carbon nanotubes coupled with near-infrared radiation on Bacillus anthracis spores: inactivates spores and stimulates the germination of surviving spores

    PubMed Central

    2013-01-01

    Background Bacillus anthracis is a pathogen that causes life-threatening disease--anthrax. B. anthracis spores are highly resistant to extreme temperatures and harsh chemicals. Inactivation of B. anthracis spores is important to ensure the environmental safety and public health. The 2001 bioterrorism attack involving anthrax spores has brought acute public attention and triggered extensive research on inactivation of B. anthracis spores. Single-walled carbon nanotubes (SWCNTs) as a class of emerging nanomaterial have been reported as a strong antimicrobial agent. In addition, continuous near infrared (NIR) radiation on SWCNTs induces excessive local heating which can enhance SWCNTs’ antimicrobial effect. In this study, we investigated the effects of SWCNTs coupled with NIR treatment on Bacillus anthracis spores. Results and discussion The results showed that the treatment of 10 μg/mL SWCNTs coupled with 20 min NIR significantly improved the antimicrobial effect by doubling the percentage of viable spore number reduction compared with SWCNTs alone treatment (88% vs. 42%). At the same time, SWCNTs-NIR treatment activated the germination of surviving spores and their dipicolinic acid (DPA) release during germination. The results suggested the dual effect of SWCNTs-NIR treatment on B. anthracis spores: enhanced the sporicidal effect and stimulated the germination of surviving spores. Molecular level examination showed that SWCNTs-NIR increased the expression levels (>2-fold) in 3 out of 6 germination related genes tested in this study, which was correlated to the activated germination and DPA release. SWCNTs-NIR treatment either induced or inhibited the expression of 3 regulatory genes detected in this study. When the NIR treatment time was 5 or 25 min, there were 3 out of 7 virulence related genes that showed significant decrease on expression levels (>2 fold decrease). Conclusions The results of this study demonstrated the dual effect of SWCNTs-NIR treatment on

  12. Exposure to Alternaria alternata in US homes is associated with asthma symptoms

    PubMed Central

    Salo, Päivi M.; Arbes, Samuel J.; Sever, Michelle; Jaramillo, Renee; Cohn, Richard D.; London, Stephanie J.; Zeldin, Darryl C.

    2007-01-01

    Background Exposure to the fungus Alternaria alternata is a risk factor for asthma. Few studies have examined Alternaria exposures in indoor environments. Objective We examined whether exposure to A alternata in US homes was associated with asthma-related outcomes. Methods The data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed a nationally representative sample of 831 housing units inhabited by 2456 individuals in 75 different locations throughout the United States. An interviewer-administered questionnaire obtained information on demographics, household characteristics, and occupants' health status. Exposure to A alternata was assessed by measuring concentrations of A alternata antigens in vacuumed dust samples using a polyclonal anti–A alternata antibody assay. Dust samples were collected from a bed, a sofa, or a chair, and from bedroom, living room, and kitchen floors. Results Lifetime prevalence of doctor-diagnosed asthma was 11.2%, and 6.9% of the study subjects reported active asthma symptoms in the past 12 months. The prevalence of current symptomatic asthma increased with increasing Alternaria concentrations in US homes; higher levels of A alternata antigens increased the odds of having asthma symptoms in the past year (relative to the lowest tertile, adjusted odds ratio was 1.52, 95% CI, 0.90−2.55 for the 2nd tertile; and 1.84, 95% CI, 1.18−2.85 for the 3rd tertile). Conclusion Exposure to A alternata in US homes is associated with active asthma symptoms. Clinical implications Measures that reduce indoor exposure to A alternata may help control asthma exacerbations. PMID:17030243

  13. Process development for the elucidation of mycotoxin formation in Alternaria alternata

    PubMed Central

    2011-01-01

    The black mould Alternaria alternata produces a wide diversity of mycotoxins which are of particular health concern. Since no maximum allowable limits are set for Alternaria toxins in food and feed, prevention of Alternaria infestations and mycotoxin spoilage is the only way to avoid health risks. Thus, the understanding of mycotoxin biosynthesis is essential. For that purpose, a reliable batch process in a 2 L bioreactor was established which enables the study of several parameters influencing the production of the mycotoxins alternariol (AOH), alternariol monomethylether (AME) and tenuazonic acid (TA) by A. alternata DSM 12633. Modified Czapek-Dox medium was used with glucose as carbon source and ammonium and nitrate as nitrogen sources. Consumption of carbon and nitrogen sources as well as formation of the three mycotoxins were monitored; the average data of five independent fermentations was plotted and fitted using a logistic equation with four parameters. Maximum mycotoxin concentrations of 3.49 ± 0.12 mg/L AOH, 1.62 ± 0.14 mg/L AME and 38.28 ± 0.1 mg/L TA were obtained. In this system the effect of different aeration rates (0.53 vvm-0.013 vvm) was tested which exerted a great influence on mycotoxin production. The use of the semi-synthetic Czapek-Dox medium allowed the exchange of carbon and nitrogen sources for acetate and aspartic acid. The use of acetate instead of glucose resulted in the sole production of alternariol whereas the exchange of ammonium and nitrate for aspartate enhanced the production of both AOH and AME while TA production was not affected. PMID:21970547

  14. Mycotoxin production in liquid culture and on plants infected with Alternaria spp. isolated from rocket and cabbage.

    PubMed

    Siciliano, Ilenia; Ortu, Giuseppe; Gilardi, Giovanna; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-03-01

    Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions. PMID:25751147

  15. Characterizing Aeroallergens by Infrared Spectroscopy of Fungal Spores and Pollen

    PubMed Central

    Zimmermann, Boris; Tkalčec, Zdenko; Mešić, Armin; Kohler, Achim

    2015-01-01

    Background Fungal spores and plant pollen cause respiratory diseases in susceptible individuals, such as asthma, allergic rhinitis and hypersensitivity pneumonitis. Aeroallergen monitoring networks are an important part of treatment strategies, but unfortunately traditional analysis is time consuming and expensive. We have explored the use of infrared spectroscopy of pollen and spores for an inexpensive and rapid characterization of aeroallergens. Methodology The study is based on measurement of spore and pollen samples by single reflectance attenuated total reflectance Fourier transform infrared spectroscopy (SR-ATR FTIR). The experimental set includes 71 spore (Basidiomycota) and 121 pollen (Pinales, Fagales and Poales) samples. Along with fresh basidiospores, the study has been conducted on the archived samples collected within the last 50 years. Results The spectroscopic-based methodology enables clear spectral differentiation between pollen and spores, as well as the separation of confamiliar and congeneric species. In addition, the analysis of the scattering signals inherent in the infrared spectra indicates that the FTIR methodology offers indirect estimation of morphology of pollen and spores. The analysis of fresh and archived spores shows that chemical composition of spores is well preserved even after decades of storage, including the characteristic taxonomy-related signals. Therefore, biochemical analysis of fungal spores by FTIR could provide economical, reliable and timely methodologies for improving fungal taxonomy, as well as for fungal identification and monitoring. This proof of principle study shows the potential for using FTIR as a rapid tool in aeroallergen studies. In addition, the presented method is ready to be immediately implemented in biological and ecological studies for direct measurement of pollen and spores from flowers and sporocarps. PMID:25867755

  16. Evolutionary development of the plant and spore wall

    PubMed Central

    Wallace, Simon; Fleming, Andrew; Wellman, Charles H.; Beerling, David J.

    2011-01-01

    Background and aims Many key innovations were required to enable plants to colonize terrestrial habitats successfully. One of these was the acquisition of a durable spore/pollen wall capable of withstanding the harsh desiccating and UV-B-rich environment encountered on land. The spores of ‘lower’ spore-bearing plants and the pollen of ‘higher’ seed plants are homologous. In recent years, researchers have begun to investigate the molecular genetics of pollen wall development in angiosperms (including the model organism Arabidopsis thaliana). However, research into the molecular genetics of spore wall development in more basal plants has thus far been extremely limited. This review summarizes the literature on spore/pollen wall development, including the molecular genetics associated with pollen wall development in angiosperms, in a preliminary attempt to identify possible candidate genes involved in spore wall development in more basal plants. Presence in moss of genes involved in pollen wall development Bioinformatic studies have suggested that genes implicated in pollen wall development in angiosperms are also present in moss and lycopsids, and may therefore be involved in spore wall development in basal plants. This suggests that the molecular genetics of spore/pollen development are highly conserved, despite the large morphological and functional differences between spores and pollen. Future work The use of high-throughput sequencing strategies and/or microarray experiments at an appropriate stage of ‘lower’ land plant sporogenesis will allow the identification of candidate genes likely to be involved in the development of the spore wall by way of comparison with those genes known to be involved in pollen wall development. Additionally, by conducting gene knock-out and gene swap experiments between ‘lower’ land plant species, such as the moss model species Physcomitrella patens, and the angiosperm model species arabidopsis it will be possible to

  17. Decontamination Options for Drinking Water Contaminated with Bacillus anthracis Spores

    SciTech Connect

    Raber, E; Burklund, A

    2010-02-16

    Five parameters were evaluated with surrogates of Bacillus anthracis spores to determine effective decontamination options for use in a contaminated drinking water supply. The parameters were: (1) type of Bacillus spore surrogate (B. thuringiensis or B. atrophaeus); (2) spore concentration in suspension (10{sup 2} to 10{sup 6} spores/ml); (3) chemical characteristics of decontaminant [sodium dicholor-s-triazinetrione dihydrate (Dichlor), hydrogen peroxide, potassium peroxymonosulfate (Oxone), sodium hypochlorite, and VirkonS{reg_sign}]; (4) decontaminant concentration (0.01% to 5%); and (5) decontaminant exposure time (10 min to 24 hr). Results from 162 suspension tests with appropriate controls are reported. Hydrogen peroxide at a concentration of 5%, and Dichlor and sodium hypochlorite at a concentration of 2%, were effective at spore inactivation regardless of spore type tested, spore exposure time, or spore concentration evaluated. This is the first reported study of Dichlor as an effective decontaminant for B. anthracis spore surrogates. Dichlor's desirable characteristics of high oxidation potential, high level of free chlorine, and more neutral pH than that of other oxidizers evaluated appear to make it an excellent alternative. All three oxidizers were effective against B. atrophaeus spores in meeting EPA's biocide standard of greater than a 6 log kill after a 10-minute exposure time and at lower concentrations than typically reported for biocide use. Solutions of 5% VirkonS{reg_sign} and Oxone were less effective decontaminants than other options evaluated in this study and did not meet the EPA's efficacy standard for biocides. Differences in methods and procedures reported by other investigators make quantitative comparisons among studies difficult.

  18. Functional Characterization of Clostridium difficile Spore Coat Proteins

    PubMed Central

    Permpoonpattana, Patima; Phetcharaburanin, Jutarop; Mikelsone, Anna; Dembek, Marcin; Tan, Sisareuth; Brisson, Marie-Clémence; La Ragione, Roberto; Brisson, Alain R.; Fairweather, Neil; Hong, Huynh A.

    2013-01-01

    Spores of Clostridium difficile play a key role in the dissemination of this important human pathogen, and until recently little has been known of their functional characteristics. Genes encoding six spore coat proteins (cotA, cotB, cotCB, cotD, cotE, and sodA) were disrupted by ClosTron insertional mutagenesis. Mutation of one gene, cotA, presented a major structural defect in spore assembly, with a clear misassembly of the outermost layers of the spore coat. The CotA protein is most probably subject to posttranslational modification and could play a key role in stabilizing the spore coat. Surprisingly, mutation of the other spore coat genes did not affect the integrity of the spore, although for the cotD, cotE, and sodA mutants, enzyme activity was reduced or abolished. This could imply that these enzymatic proteins are located in the exosporium or alternatively that they are structurally redundant. Of the spore coat proteins predicted to carry enzymatic activity, three were confirmed to be enzymes using both in vivo and in vitro methods, the latter using recombinant expressed proteins. These were a manganese catalase, encoded by cotD, a superoxide dismutase (SOD), encoded by sodA, and a bifunctional enzyme with peroxiredoxin and chitinase activity, encoded by cotE. These enzymes being exposed on the spore surface would play a role in coat polymerization and detoxification of H2O2. Two additional proteins, CotF (a tyrosine-rich protein and potential substrate for SodA) and CotG (a putative manganese catalase) were shown to be located at the spore surface. PMID:23335421

  19. Survival of Spores of Trichoderma longibrachiatum in Space: data from the Space Experiment SPORES on EXPOSE-R

    NASA Astrophysics Data System (ADS)

    Neuberger, Katja; Lux-Endrich, Astrid; Panitz, Corinna

    2015-01-01

    In the space experiment `Spores in artificial meteorites' (SPORES), spores of the fungus Trichoderma longibrachiatum were exposed to low-Earth orbit for nearly 2 years on board the EXPOSE-R facility outside of the International Space Station. The environmental conditions tested in space were: space vacuum at 10-7-10-4 Pa or argon atmosphere at 105 Pa as inert gas atmosphere, solar extraterrestrial ultraviolet (UV) radiation at λ > 110 nm or λ > 200 nm with fluences up to 5.8 × 108 J m-2, cosmic radiation of a total dose range from 225 to 320 mGy, and temperature fluctuations from -25 to +50°C, applied isolated or in combination. Comparable control experiments were performed on ground. After retrieval, viability of spores was analysed by two methods: (i) ethidium bromide staining and (ii) test of germination capability. About 30% of the spores in vacuum survived the space travel, if shielded against insolation. However, in most cases no significant decrease was observed for spores exposed in addition to the full spectrum of solar UV irradiation. As the spores were exposed in clusters, the outer layers of spores may have shielded the inner part. The results give some information about the likelihood of lithopanspermia, the natural transfer of micro-organisms between planets. In addition to the parameters of outer space, sojourn time in space seems to be one of the limiting parameters.

  20. Alternaria arborescens infection in a healthy individual and literature review of cutaneous alternariosis.

    PubMed

    Hu, Wenying; Ran, Yuping; Zhuang, Kaiwen; Lama, Jebina; Zhang, Chaoliang

    2015-02-01

    A 28-year-old man presented at our clinic with 1-month history of an ulcer covered with crust on his left anterior tibia. Based on the morphological features and molecular identification, the patient was diagnosed as cutaneous alternariosis caused by Alternaria arborescens. He was successfully cured by oral itraconazole and topical use of 0.25% liposomal amphotericin B. A review of published studies revealed 29 cases of cutaneous alternariosis. Most cases (90%) occurred in immunosuppressed patients; itraconazole (59%) and voriconazole (24%) are the most effective treatments of choices. PMID:25370461

  1. Secondary metabolites from a strain of Alternaria tenuissima Isolated from Northern Manitoba soil.

    PubMed

    Anyanwu, Chukwudi S; Sorensen, John L

    2015-01-01

    Deoxyphomalone (1), dimethyl 4-methyl-2,6-pyridinedicarboxylate (2), stemphyperylenol (3), and N-methyl-2-pyrrolidone (4) were isolated from the fermentation broth of a strain of the fungus, Alternaria tenuissima. This fungus was isolated from the soil underlying the lichen, Peltigera didactyla, which had been collected from Wapusk National Park in Northern Manitoba. The structures of the compounds were determined by comprehensive analysis of their spectroscopic data including FT-IR, 1D and 2D NMR spectroscopy and mass spectrometry; and their bioactivities were tested against E.coli cells. The taxonomic identity of the fungus was confirmed by ITS sequencing of its ribosomal DNA. PMID:25920216

  2. Perylene derivatives produced by Alternaria alternata, an endophytic fungus isolated from Laurencia species.

    PubMed

    Gao, Shu-Shan; Li, Xiao-Ming; Wang, Bin-Gui

    2009-11-01

    Two new perylene derivatives, 7-epi-8-hydroxyaltertoxin I (1) and 6-epi-stemphytriol (2), along with two known compounds stemphyperylenol (3) and altertoxin I (4) were isolated from Alternaria alternata, a marine endophytic fungus derived from an unidentified algal species of the genus Laurencia. Structures of compounds 1-4 were determined on the basis of detailed spectroscopic analysis, as well as by comparison with literature reports. The antimicrobial activities of compounds 1 and 3 against Staphylococcus aureus, Escherichia coli, and Aspergillus niger were evaluated; neither showed obvious activity. PMID:19967977

  3. Proteomic analysis of Alternaria alternata (Fr.) Keissler responds to COS fumigation.

    PubMed

    Liu, Tao; Li, Li; Qu, Haixia; Zhan, Guoping; Liu, Bo; Wang, Yuejin

    2010-01-01

    Carbonyl sulfide (COS) is a new fumigant which has been a potential alternative to methyl bromide and phosphine in many applications. In this study, we investigated the fungitoxicity of COS towards the pathogen of pear black spot disease Alternaria alternata (Fr.) Keissler (A. alternata). Moreover, proteomic analysis and RT-PCR was performed and our results showed that during the fumigation, the regulation of 21 proteins in protein expression and mRNA accumulation levels is involved, which respond to growth inhibition caused by COS. These results provide new clues for the mechanism of the fungitoxicity of COS. PMID:20036892

  4. First Report of Black Spot Disease Caused by Alternaria alternata on Sweet Persimmon Fruits

    PubMed Central

    Lee, Jung Han; Kim, Jinwoo

    2013-01-01

    Black spot of sweet persimmon, caused by Alternaria alternata, occurred in an orchard in Gyeongnam province, Korea in 2012. The symptom was appearance of 0.5 to 4 cm black spots on the surface of fruit. The pathogen was isolated from flesh of disease lesions. The causal agent was identified as A. alternata by morphological characteristics and sequencers of the internal transcribed spacer (ITS) 1 and ITS4 regions of rRNA. Artificial inoculation of the pathogen resulted in development of disease symptoms and the re-isolated pathogen showed characteristics of A. alternata. PMID:24198674

  5. Nuclear Ribosomal DNA Variation and Pathogenic Specialization in Alternaria Fungi Known To Produce Host-Specific Toxins †

    PubMed Central

    Kusaba, Motoaki; Tsuge, Takashi

    1994-01-01

    A total of 99 strains of 11 Alternaria species, including 68 strains of seven fungi known to produce host-specific toxins, were subjected to analysis of restriction fragment length polymorphism (RFLP) in nuclear ribosomal DNA (rDNA). Total DNA was digested with XbaI, and the Southern blots were probed with a nuclear rDNA clone of Alternaria kikuchiana. The hybridization gave 17 different RFLPs from the 99 strains. On the basis of these RFLPs, populations of host-specific toxin-producing fungi could not be differentiated from one another nor from nonpathogenic A. alternata. Each population of the toxin-producing fungi carried rDNA variants. Nine different types, named A1 to A6 and B1 to B3, were detected among the toxin-producing fungi and nonpathogenic A. alternata. All of the populations contained the type A4 variant, and the other rDNA types were also shared by different toxin-producing fungi and A. alternata. In contrast, Alternaria species that are morphologically distinguishable from A. alternata could be differentiated from A. alternata on the basis of the rDNA RFLPs. Polymorphisms in rDNA digested with HaeIII and MspI were also evaluated in 61 Alternaria strains. These restriction enzymes produced 31 variations among all of the samples. The seven toxin-producing fungi and nonpathogenic A. alternata could not be resolved by phylogenetic analysis based on the RFLPs, although they could be differentiated from the other Alternaria species studied. These results provide support for the hypothesis that Alternaria fungi known to produce host-specific toxins are intraspecific variants of A. alternata specialized in pathogenicity. Images PMID:16349367

  6. Methods for neutralizing anthrax or anthrax spores

    DOEpatents

    Sloan, Mark A; Vivekandanda, Jeevalatha; Holwitt, Eric A; Kiel, Johnathan L

    2013-02-26

    The present invention concerns methods, compositions and apparatus for neutralizing bioagents, wherein bioagents comprise biowarfare agents, biohazardous agents, biological agents and/or infectious agents. The methods comprise exposing the bioagent to an organic semiconductor and exposing the bioagent and organic semiconductor to a source of energy. Although any source of energy is contemplated, in some embodiments the energy comprises visible light, ultraviolet, infrared, radiofrequency, microwave, laser radiation, pulsed corona discharge or electron beam radiation. Exemplary organic semiconductors include DAT and DALM. In certain embodiments, the organic semiconductor may be attached to one or more binding moieties, such as an antibody, antibody fragment, or nucleic acid ligand. Preferably, the binding moiety has a binding affinity for one or more bioagents to be neutralized. Other embodiments concern an apparatus comprising an organic semiconductor and an energy source. In preferred embodiments, the methods, compositions and apparatus are used for neutralizing anthrax spores.

  7. Effect of mechanical abrasion on the viability, disruption and germination of spores of Bacillus subtilis

    PubMed Central

    Jones, C.A.; Padula, N.L.; Setlow, P.

    2005-01-01

    Aims To elucidate the factors influencing the sensitivity of Bacillus subtilis spores to killing and disruption by mechanical abrasion, and the mechanism of stimulation of spore germination by abrasion. Methods and Results Spores of B. subtilis strains were abraded by shaking with glass beads in liquid or the dry state, and spore killing, disruption and germination were determined. Dormant spores were more resistant to killing and disruption by abrasion than were growing cells or germinated spores. However, dormant spores of the wild-type strain with or without most coat proteins removed, spores of strains with mutations causing spore coat defects, spores lacking their large depot of dipicolinic acid (DPA) and spores with defects in the germination process exhibited essentially identical rates of killing and disruption by abrasion. When spores lacking all nutrient germinant receptors were enumerated by plating directly on nutrient medium, abrasion increased the plating efficiency of these spores before killing them. Spores lacking all nutrient receptors and either of the two redundant cortex-lytic enzymes behaved similarly in this regard, but the plating efficiency of spores lacking both cortex-lytic enzymes was not stimulated by abrasion. Conclusions Dormant spores are more resistant to killing and disruption by abrasion than are growing cells or germinated spores, and neither the complete coats nor DPA are important in spore resistance to such treatments. Germination is not essential for spore killing by abrasion, although abrasion can trigger spore germination by activation of either of the spore’s cortex-lytic enzymes. Significance and Importance This work provides new insight into the mechanisms of the killing, disruption and germination of spores by abrasion and makes the surprising finding that at least much of the spore coat is not important in spore resistance to abrasion. PMID:16313421

  8. Elastic and inelastic light scattering from single bacterial spores in an optical trap allows the monitoring of spore germination dynamics

    PubMed Central

    Peng, Lixin; Chen, De; Setlow, Peter; Li, Yong-qing

    2009-01-01

    Raman scattering spectroscopy and elastic light scattering intensity (ESLI) were used to simultaneously measure levels of Ca-dipicolinic acid (CaDPA) and changes in spore morphology and refractive index during germination of individual B. subtilis spores with and without the two redundant enzymes (CLEs), CwlJ and SleB, that degrade spores’ peptidoglycan cortex. Conclusions from these measurements include: 1) CaDPA release from individual wild-type germinating spores was biphasic; in a first heterogeneous slow phase, Tlag, CaDPA levels decreased ∼15% and in the second phase ending at Trelease, remaining CaDPA was released rapidly; 2) in L-alanine germination of wild-type spores and spores lacking SleB: a) the ESLI rose ∼2-fold shortly before Tlag at T1; b) following Tlag, the ESLI again rose ∼2-fold at T2 when CaDPA levels had decreased ∼50%; and c) the ESLI reached its maximum value at ∼Trelease and then decreased; 3) in CaDPA germination of wild-type spores: a) Tlag increased and the first increase in ESLI occurred well before Tlag, consistent with different pathways for CaDPA and L-alanine germination; b) at Trelease the ESLI again reached its maximum value; 4) in L-alanine germination of spores lacking both CLEs and unable to degrade their cortex, the time ΔTrelease (Trelease–Tlag) for excretion of ≥75% of CaDPA was ∼15-fold higher than that for wild-type or sleB spores; and 5) spores lacking only CwlJ exhibited a similar, but not identical ESLI pattern during L-alanine germination to that seen with cwlJ sleB spores, and the high value for ΔTrelease. PMID:19374431

  9. Exposure to airborne fungi and bacteria while commuting in passenger cars and public buses

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Hyun; Jo, Wan-Kuen

    The present study examined airborne microbe levels inside and outside passenger cars and public buses during two seasons (winter and summer). The prevalence level of individual fungal genera depended on the fungi and agar type, whereas a constant higher prevalence (>90%) was found for the total bacteria and total fungi. The four most prevalent fungal genera were Cladosporium, Penicillium, Aspergillus, and Alternaria in a descending order. The major parameters associated with the airborne microbe measurements included agar type, vehicle type, and seasonal variation. When compared to the malt extract agar (MEA), the dichloran glycerol 18 agar (DG-18) was found to produce better counts for the target fungi. The summer in-vehicle bacterial concentrations were significantly higher for public buses than for the passenger cars, whereas the reverse was true for summer in-vehicle total fungal concentrations. This pattern was also consistent with summer outdoor results. In contrast, the winter in-vehicle and outdoor airborne microbe levels were similar for cars and buses. Meanwhile, summer was generally found to have higher in-vehicle fungal concentrations than winter. The current in-vehicle airborne microbe concentrations were found to be similar to residential indoor values from other reports, such as bacterial values between 10 and 10 3 CFU m -3 and total fungal aerosol concentrations ranging from 10 to 10 3 CFU m -3. It was suggested that motor vehicles in which many individuals spend a certain percentage of their day or week for travel are also a potential microenvironment for individual exposure to airborne microbes.

  10. [Air-borne disease].

    PubMed

    Lameiro Vilariño, Carmen; del Campo Pérez, Victor M; Alonso Bürger, Susana; Felpeto Nodar, Irene; Guimarey Pérez, Rosa; Pérez Alvarellos, Alberto

    2003-11-01

    Respiratory protection is a factor which worries nursing professionals who take care of patients susceptible of transmitting microorganisms through the air more as every day passes. This type of protection covers the use of surgical or hygienic masks against the transmission of infection by airborne drops to the use of highly effective masks or respirators against the transmission of airborne diseases such as tuberculosis or SARS, a recently discovered disease. The adequate choice of this protective device and its correct use are fundamental in order to have an effective protection for exposed personnel. The authors summarize the main protective respiratory devices used by health workers, their characteristics and degree of effectiveness, as well as the circumstances under which each device is indicated for use. PMID:14705591

  11. Peptide Synthesis by Extracts from Bacillus subtilis Spores

    PubMed Central

    Bishop, Helen L.; Migita, Lloyd K.; Doi, Roy H.

    1969-01-01

    Cell-free peptide synthesis by extracts from vegetative cells and spores of Bacillus subtilis was analyzed and compared. The initial rate of phenylalanine incorporation in a polyuridylate-directed system was found to be in a similar range for the two extracts. However, spore extracts frequently incorporated less total phenylalanine as did the vegetative cell system. Optimal conditions for amino acid incorporation by spore extracts were found to be similar to those of vegetative cell extracts. Polyphenylalanine synthesis was stimulated by preincubation of both extracts prior to the addition of polyuridylic acid (poly U) and labeled phenylalanine. Both systems showed a dependence on an energy-generating system and were inhibited by chloramphenicol and puromycin. Ribonuclease, but not deoxyribonuclease, inhibited the reaction significantly. The presence of methionine transfer ribonucleic acid (tRNAF) and methionyl-tRNAF transformylase was demonstrated in spore extracts. An analysis of several aminoacyl-tRNAs in spores revealed that the relative amounts of these tRNAs were similar to those found in vegetative cells. Only lysine tRNA was found to be present in relatively greater amounts in spores. These results indicate that dormant spores of B. subtilis contain the machinery for the translation of genetic information. PMID:4984176

  12. Water Behavior in Bacterial Spores by Deuterium NMR Spectroscopy

    PubMed Central

    2015-01-01

    Dormant bacterial spores are able to survive long periods of time without nutrients, withstand harsh environmental conditions, and germinate into metabolically active bacteria when conditions are favorable. Numerous factors influence this hardiness, including the spore structure and the presence of compounds to protect DNA from damage. It is known that the water content of the spore core plays a role in resistance to degradation, but the exact state of water inside the core is a subject of discussion. Two main theories present themselves: either the water in the spore core is mostly immobile and the core and its components are in a glassy state, or the core is a gel with mobile water around components which themselves have limited mobility. Using deuterium solid-state NMR experiments, we examine the nature of the water in the spore core. Our data show the presence of unbound water, bound water, and deuterated biomolecules that also contain labile deuterons. Deuterium–hydrogen exchange experiments show that most of these deuterons are inaccessible by external water. We believe that these unreachable deuterons are in a chemical bonding state that prevents exchange. Variable-temperature NMR results suggest that the spore core is more rigid than would be expected for a gel-like state. However, our rigid core interpretation may only apply to dried spores whereas a gel core may exist in aqueous suspension. Nonetheless, the gel core, if present, is inaccessible to external water. PMID:24950158

  13. Dry-Heat Inactivation Kinetics of Naturally Occurring Spore Populations

    PubMed Central

    Bond, W. W.; Favero, M. S.; Petersen, N. J.; Marshall, J. H.

    1970-01-01

    Twenty-three soil samples were collected from areas of the United States where major spacecraft assembly and launch facilities are in operation. Soil samples were treated with ethyl alcohol, ultrasonic energy, and gross filtration. The resultant suspensions consisted of viable, naturally occurring bacterial spores and were used to inoculate stainless-steel strips. The strips were suspended in a forced air oven and assays were made at 5-min intervals for the number of viable spores. Most survivor curves were nonlinear. Subsequently, spore crops of heat-sensitive and heat-resistant soil isolates were found to have linear survivor curves at 125 C which were unaffected by the presence or absence of sterile soil particles from the parent sample. When two spore crops, one of which was heat-resistant and the other heat-sensitive, were mixed, the resultant nonlinear curves were unaffected by the presence or absence of sterile parent soil. Therefore, the survivor curves obtained originally with the soils were the result of heterogeneous spore populations rather than of protection afforded by soil particles in our test system. These results question the rationale both of assuming logarithmic death and of using decimal-reduction values obtained with subcultured standard reference spores in the derivation of dry-heat sterilization cycles for items contaminated with naturally occurring spore populations. PMID:5498605

  14. Infrared signatures to discriminate viability of autoclaved Bacillus spores

    NASA Astrophysics Data System (ADS)

    Schneider, Matthew D. W.; Valentine, Nancy B.; Johnson, Timothy J.

    2011-11-01

    Optical methods can offer good sensitivity for detecting small amounts of chemicals and biologicals, and as these methods mature, are some of the few techniques that can offer true standoff detection. For detection of biological species, determining the viability is clearly important: Certain species of gram-positive bacteria are capable of forming endospores, specialized structures that arise when living conditions become unfavorable or little growth medium is available. Spores are also resistant to many chemicals as well as changes in heat or pH; such spores can remain dormant from months to years until more favorable conditions arise, resulting in germination back to the vegetative state. This persistence characteristic of bacterial spores allows for contamination of a surface (e.g. food or medical equipment) even after the surface has been nominally cleaned. Bacterial spores have also been used as biological weapons, as in the case of B. anthracis. Thus, having rapid analytical methods to determine a spore's viability after attempts to clean a given environment is crucial. The increasing availability of portable spectrometers may provide a key to such rapid onsite analysis. The present study was designed to determine whether infrared spectroscopy may be used to differentiate between viable vs. dead B. subtilis and B. atrophaeus spores. Preliminary results show that the reproducible differences in the IR signatures can be used to identify the viable vs. the autoclaved (dead) spores.

  15. Airborne forest fire research

    NASA Technical Reports Server (NTRS)

    Mattingly, G. S.

    1974-01-01

    The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included.

  16. MLS airborne antenna research

    NASA Technical Reports Server (NTRS)

    Yu, C. L.; Burnside, W. D.

    1975-01-01

    The geometrical theory of diffraction was used to analyze the elevation plane pattern of on-aircraft antennas. The radiation patterns for basic elements (infinitesimal dipole, circumferential and axial slot) mounted on fuselage of various aircrafts with or without radome included were calculated and compared well with experimental results. Error phase plots were also presented. The effects of radiation patterns and error phase plots on the polarization selection for the MLS airborne antenna are discussed.

  17. Endotrophic Calcium, Strontium, and Barium Spores of Bacillus megaterium and Bacillus cereus1

    PubMed Central

    Foerster, Harold F.; Foster, J. W.

    1966-01-01

    Foerster, Harold F. (The University of Texas, Austin), and J. W. Foster. Endotrophic calcium, strontium, and barium spores of Bacillus megaterium and Bacillus cereus. J. Bacteriol. 91:1333–1345. 1966.—Spores were produced by washed vegetative cells suspended in deionized water supplemented with CaCl2, SrCl2, or BaCl2. Normal, refractile spores were produced in each case; a portion of the barium spores lost refractility and darkened. Thin-section electron micrographs revealed no apparent anatomical differences among the three types of spores. Analyses revealed that the different spore types were enriched specifically in the metal to which they were exposed during sporogenesis. The calcium content of the strontium and the barium spores was very small. From binary equimolar mixtures of the metal salts, endotrophic spores accumulated both metals to nearly the same extent. Viability of the barium spores was considerably less than that of the other two types. Strontium and barium spores were heat-resistant; however, calcium was essential for maximal heat resistance. Significant differences existed in the rates of germination; calcium spores germinated fastest, strontium spores were slower, and barium spores were slowest. Calcium-barium and calcium-strontium spores germinated readily. Endotrophic calcium and strontium spores germinated without the prior heat activation essential for growth spores. Chemical germination of the different metal-type spores with n-dodecylamine took place at the same relative rates as physiological germination. Heat-induced release of dipicolinic acid occurred much faster with barium and strontium spores than with calcium spores. The washed “coat fraction” from disrupted spores contained little of the spore calcium but most of the spore barium. The metal in this fraction was released by dilute acid. The demineralized coats reabsorbed calcium and barium at neutral pH. Images PMID:4956334

  18. Airborne field strength monitoring

    NASA Astrophysics Data System (ADS)

    Bredemeyer, J.; Kleine-Ostmann, T.; Schrader, T.; Münter, K.; Ritter, J.

    2007-06-01

    In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper.

  19. Mutagenicity of airborne particles.

    PubMed

    Chrisp, C E; Fisher, G L

    1980-09-01

    The physical and chemical properties of airborne particles are important for the interpretation of their potential biologic significance as genotoxic hazards. For polydisperse particle size distributions, the smallest, most respirable particles are generally the most mutagenic. Particulate collection for testing purposes should be designed to reduce artifact formation and allow condensation of mutagenic compounds. Other critical factors such as UV irradiation, wind direction, chemical reactivity, humidity, sample storage, and temperature of combustion are important. Application of chemical extraction methods and subsequent class fractionation techniques influence the observed mutagenic activity. Particles from urban air, coal fly ash, automobile and diesel exhaust, agricultural burning and welding fumes contain primarily direct-acting mutagens. Cigarette smoke condensate, smoke from charred meat and protein pyrolysates, kerosene soot and cigarette smoke condensates contain primarily mutagens which require metabolic activation. Fractionation coupled with mutagenicity testing indicates that the most potent mutagens are found in the acidic fractions of urban air, coal fly ash, and automobile diesel exhaust, whereas mutagens in rice straw smoke and cigarette smoke condensate are found primarily in the basic fractions. The interaction of the many chemical compounds in complex mixtures from airborne particles is likely to be important in determining mutagenic or comutagenic potentials. Because the mode of exposure is generally frequent and prolonged, the presence of tumor-promoting agents in complex mixtures may be a major factor in evaluation of the carcinogenic potential of airborne particles. PMID:7005667

  20. Ultrastructural Variability of the Exosporium Layer of Clostridium difficile Spores.

    PubMed

    Pizarro-Guajardo, Marjorie; Calderón-Romero, Paulina; Castro-Córdova, Pablo; Mora-Uribe, Paola; Paredes-Sabja, Daniel

    2016-01-01

    The anaerobic sporeformer Clostridium difficile is the leading cause of nosocomial antibiotic-associated diarrhea in developed and developing countries. The metabolically dormant spore form is considered the transmission, infectious, and persistent morphotype, and the outermost exosporium layer is likely to play a major role in spore-host interactions during the first contact of C. difficile spores with the host and for spore persistence during recurrent episodes of infection. Although some studies on the biology of the exosporium have been conducted (J. Barra-Carrasco et al., J Bacteriol 195:3863-3875, 2013, http://dx.doi.org/10.1128/JB.00369-13; J. Phetcharaburanin et al., Mol Microbiol 92:1025-1038, 2014, http://dx.doi.org/10.1111/mmi.12611), there is a lack of information on the ultrastructural variability and stability of this layer. In this work, using transmission electron micrographs, we analyzed the variability of the spore's outermost layers in various strains and found distinctive variability in the ultrastructural morphotype of the exosporium within and between strains. Through transmission electron micrographs, we observed that although this layer was stable during spore purification, it was partially lost after 6 months of storage at room temperature. These observations were confirmed by indirect immunofluorescence microscopy, where a significant decrease in the levels of two exosporium markers, the N-terminal domain of BclA1 and CdeC, was observed. It is also noteworthy that the presence of the exosporium marker CdeC on spores obtained from C. difficile biofilms depended on the biofilm culture conditions and the strain used. Collectively, these results provide information on the heterogeneity and stability of the exosporium surface of C. difficile spores. These findings have direct implications and should be considered in the development of novel methods to diagnose and/or remove C. difficile spores by using exosporium proteins as targets. PMID

  1. The ecology of anthrax spores: tough but not invincible.

    PubMed Central

    Dragon, D C; Rennie, R P

    1995-01-01

    Bacillus anthracis is the causative agent of anthrax, a serious and often fatal disease of wild and domestic animals. Central to the persistence of anthrax in an area is the ability of B. anthracis to form long-lasting, highly resistant spores. Understanding the ecology of anthrax spores is essential if one hopes to control epidemics. Studies on the ecology of anthrax have found a correlation between the disease and specific soil factors, such as alkaline pH, high moisture, and high organic content. Researchers initially suggested that these factors influenced vegetative anthrax bacilli. However, subsequent research has shown that vegetative cells of B. anthracis have very specific nutrient and physiological requirements and are unlikely to survive outside a host. Review of the properties of spores of B. anthracis and other Bacillus species suggests that the specific soil factors linked to epidemic areas reflect important environmental conditions that aid the anthrax spores in causing epidemics. Specifically, high levels of calcium in the soil may help to maintain spore vitality for prolonged periods, thereby increasing the chance of spores encountering and infecting a new host. Cycles of runoff and evaporation may collect spores dispersed from previous epidemics into storage areas, thereby concentrating them. Uptake of large doses of viable spores from storage areas by susceptible animals, via altered feeding or breeding behavior, may then allow the bacterium to establish infection and cause a new epidemic. Literature search for this review was done by scanning the Life Sciences Collection 1982-1994 using the keywords "anthrax" and "calcium and spore." Images Figure 1. PMID:7773917

  2. Sterilization Resistance of Bacterial Spores Explained with Water Chemistry.

    PubMed

    Friedline, Anthony W; Zachariah, Malcolm M; Middaugh, Amy N; Garimella, Ravindranath; Vaishampayan, Parag A; Rice, Charles V

    2015-11-01

    Bacterial spores can survive for long periods without nutrients and in harsh environmental conditions. This survival is influenced by the structure of the spore, the presence of protective compounds, and water retention. These compounds, and the physical state of water in particular, allow some species of bacterial spores to survive sterilization schemes with hydrogen peroxide and UV light. The chemical nature of the spore core and its water has been a subject of some contention and the chemical environment of the water impacts resistance paradigms. Either the spore has a glassy core, where water is immobilized along with other core components, or the core is gel-like with mobile water diffusion. These properties affect the movement of peroxide and radical species, and hence resistance. Deuterium solid-state NMR experiments are useful for examining the nature of the water inside the spore. Previous work in our lab with spores of Bacillus subtilis indicate that, for spores, the core water is in a more immobilized state than expected for the gel-like core theory, suggesting a glassy core environment. Here, we report deuterium solid-state NMR observations of the water within UV- and peroxide-resistant spores from Bacillus pumilus SAFR-032. Variable-temperature NMR experiments indicate no change in the line shape after heating to 50 °C, but an overall decrease in signal after heating to 100 °C. These results show glass-like core dynamics within B. pumilus SAFR-032 that may be the potential source of its known UV-resistance properties. The observed NMR traits can be attributed to the presence of an exosporium containing additional labile deuterons that can aid in the deactivation of sterilizing agents. PMID:26435315

  3. Immunomagnetic capture of Bacillus anthracis spores from food.

    PubMed

    Shields, Michael J; Hahn, Kristen R; Janzen, Timothy W; Goji, Noriko; Thomas, Matthew C; Kingombe, Cesar Bin I; Paquet, Chantal; Kell, Arnold J; Amoako, Kingsley K

    2012-07-01

    Food is a vulnerable target for potential bioterrorist attacks; therefore, a critical mitigation strategy is needed for the rapid concentration and detection of biothreat agents from food matrices. Magnetic beads offer a unique advantage in that they have a large surface area for efficient capture of bacteria. We have demonstrated the efficient capture and concentration of Bacillus anthracis (Sterne) spores using immunomagnetic beads for a potential food application. Magnetic beads from three different sources, with varying sizes and surface chemistries, were functionalized with monoclonal antibodies and polyclonal antibodies from commercial sources and used to capture and concentrate anthrax spores from spiked food matrices, including milk, apple juice, bagged salad, processed meat, and bottled water. The results indicated that the Pathatrix beads were more effective in the binding and capture of anthrax spores than the other two bead types investigated. Furthermore, it was observed that the use of polyclonal antibodies resulted in a more efficient recovery of anthrax spores than the use of monoclonal antibodies. Three different magnetic capture methods, inversion, the Pathatrix Auto system, and the new i CropTheBug system, were investigated. The i CropTheBug system yielded a much higher recovery of spores than the Pathatrix Auto system. Spore recoveries ranged from 80 to 100% for the i CropTheBug system when using pure spore preparations, whereas the Pathatrix Auto system had recoveries from 20 to 30%. Spore capture from food samples inoculated at a level of 1 CFU/ml resulted in 80 to 100% capture for milk, bottled water, and juice samples and 60 to 80% for processed meat and bagged salad when using the i CropTheBug system. This efficient capture of anthrax spores at very low concentrations without enrichment has the potential to enhance the sensitivity of downstream detection technologies and will be a useful method in a foodborne bioterrorism response. PMID

  4. Bacteriocins: Novel Solutions to Age Old Spore-Related Problems?

    PubMed

    Egan, Kevin; Field, Des; Rea, Mary C; Ross, R Paul; Hill, Colin; Cotter, Paul D

    2016-01-01

    Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, which have the ability to kill or inhibit other bacteria. Many bacteriocins are produced by food grade lactic acid bacteria (LAB). Indeed, the prototypic bacteriocin, nisin, is produced by Lactococcus lactis, and is licensed in over 50 countries. With consumers becoming more concerned about the levels of chemical preservatives present in food, bacteriocins offer an alternative, more natural approach, while ensuring both food safety and product shelf life. Bacteriocins also show additive/synergistic effects when used in combination with other treatments, such as heating, high pressure, organic compounds, and as part of food packaging. These features are particularly attractive from the perspective of controlling sporeforming bacteria. Bacterial spores are common contaminants of food products, and their outgrowth may cause food spoilage or food-borne illness. They are of particular concern to the food industry due to their thermal and chemical resistance in their dormant state. However, when spores germinate they lose the majority of their resistance traits, making them susceptible to a variety of food processing treatments. Bacteriocins represent one potential treatment as they may inhibit spores in the post-germination/outgrowth phase of the spore cycle. Spore eradication and control in food is critical, as they are able to spoil and in certain cases compromise the safety of food by producing dangerous toxins. Thus, understanding the mechanisms by which bacteriocins exert their sporostatic/sporicidal activity against bacterial spores will ultimately facilitate their optimal use in food. This review will focus on the use of bacteriocins alone, or in combination with other innovative processing methods to control spores in food, the current knowledge and gaps therein with regard to bacteriocin-spore interactions and discuss future research approaches to enable spores to be more

  5. Airborne wireless communication systems, airborne communication methods, and communication methods

    DOEpatents

    Deaton, Juan D.; Schmitt, Michael J.; Jones, Warren F.

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  6. Possibility of Alternaria toxins reduction by extrusion processing of whole wheat flour.

    PubMed

    Janić Hajnal, Elizabet; Čolović, Radmilo; Pezo, Lato; Orčić, Dejan; Vukmirović, Đuro; Mastilović, Jasna

    2016-12-15

    This study represents the first report about possibility of reduction of Alternaria toxins in wheat using the extrusion process. Effects of extrusion processing parameters - moisture content (w=16, 20, 24g/100g), feeding rate (q=15, 20, 25kg/h), and screw speed (v=300, 390, 480rpm), on reduction rate of tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME), in whole wheat flour were investigated. Temperature ranged between 111.1 and 160.8°C, while the absolute pressure was from 0.17 to 0.23MPa. The simultaneous influence of w and v was the most important for TeA reduction (p<0.05), while v and q were the most influential for AOH reduction (p<0.01). Level of AME reduction was mostly influenced by w and v (p<0.10). Optimal parameters for reduction of all three Alternaria toxins were as follows: w=24g/100g, q=25kg/h, v=390rpm, with a reduction of 65.6% for TeA, 87.9% for AOH and 94.5% for AME. PMID:27451248

  7. Characterization of a genotoxic impact compound in Alternaria alternata infested rice as Altertoxin II.

    PubMed

    Schwarz, Christoph; Tiessen, Christine; Kreutzer, Martin; Stark, Timo; Hofmann, Thomas; Marko, Doris

    2012-12-01

    Toxicity-guided fractionation was used to identify DNA strand breaking impact compounds in extracts obtained from rice heavily infested with the Alternaria alternata strains DSM 62006 and DSM 62010. The major genotoxic potential measured in the comet assay using human colon carcinoma cells (HT29) could be attributed to three unknown peaks, whereas the fractions containing alternariol, its monomethylether or tenuazonic acid showed no significant DNA damaging effects. According to (1)H and (13)C-NMR spectroscopy, one genotoxic impact compound was identified as Altertoxin II (ATXII). ATXII showed potent DNA damaging properties in HT29 cells with substantial induction of formamidopyrimidine DNA glycosylase (FPG)-sensitive sites. However, no effect was observed with respect to the cellular redox status, measured in the DCF assay and as total glutathione. The induction of apoptosis could be excluded as a potential reason for enhanced DNA damage. After 24 h of incubation with 1 μM ATX II, a significant increase of cells in the G(0)/G(1) phase was observed together with an inhibition of cell proliferation in the sulforhodamine B assay. Taken together, ATX II was found to contribute substantially to the genotoxic effects of complex extracts obtained from Alternaria alternata infested rice. The results demonstrate the high genotoxic potency of ATX II in human cells, underlining the necessity for further studies on the occurrence in food and its relevance for food safety. PMID:23076116

  8. Alternaria extract activates autophagy that induces IL-18 release from airway epithelial cells.

    PubMed

    Murai, Hiroki; Okazaki, Shintaro; Hayashi, Hisako; Kawakita, Akiko; Hosoki, Koa; Yasutomi, Motoko; Sur, Sanjiv; Ohshima, Yusei

    2015-09-01

    Alternaria alternata is a major outdoor allergen that causes allergic airway diseases. Alternaria extract (ALT-E) has been shown to induce airway epithelial cells to release IL-18 and thereby initiate Th2-type responses. We investigated the underlying mechanisms involved in IL-18 release from ALT-E-stimulated airway epithelial cells. Normal human bronchial epithelial cells and A549 human lung adenocarcinoma cells were stimulated with ALT-E in the presence of different inhibitors of autophagy or caspases. IL-18 levels in culture supernatants were measured by ELISA. The numbers of autophagosomes, an LC3-I to LC3-II conversion, and p62 degradation were determined by immunofluorescence staining and immunoblotting. 3-methyladenine and bafilomycin, which inhibit the formation of preautophagosomal structures and autolysosomes, respectively, suppressed ALT-E-induced IL-18 release by cells, whereas caspase 1 and 8 inhibitors did not. ALT-E-stimulation increased autophagosome formation, LC-3 conversion, and p62 degradation in airway epithelial cells. LPS-stimulation induced the LC3 conversion in A549 cells, but did not induce IL-18 release or p62 degradation. Unlike LPS, ALT-E induced airway epithelial cells to release IL-18 via an autophagy dependent, caspase 1 and 8 independent pathway. Although autophagy has been shown to negatively regulate canonical inflammasome activity in TLR-stimulated macrophages, our data indicates that this process is an unconventional mechanism of IL-18 secretion by airway epithelial cells. PMID:26032499

  9. New cytotoxic compounds of endophytic fungus Alternaria sp. isolated from Broussonetia papyrifera (L.) Vent.

    PubMed

    Zhang, Naidan; Zhang, Chunyan; Xiao, Xiao; Zhang, Qiaoyan; Huang, Baokang

    2016-04-01

    From the ethyl acetate extract of a culture of the endophytic fungus Alternaria species G7 in Broussonetia papyrifera, a new compound altertoxin IV (1) together with nine known compounds were isolated and identified by means of bioassay-guided fractionation. The structures of these compounds were established on the basis of spectroscopic methods, among which the absolute configuration of compound 1, a new tetrahydroperylenone derivative, was determined by means of X-Ray Crystallographic analysis. The isolated compounds were subjected to cytotoxic activity against three human cancer cell lines (A549, MG-63, and SMMC-7721). Compound 2 showed significant cytotoxic activities against tested cell lines, with IC50 values of 1.47, 2.11 and 7.34 μg/mL, respectively. Additionally, compound 4 also exhibited significant cytotoxic activities against cell lines MG-63 and SMMC-7721, with IC50 values of 0.53 and 2.92 μg/mL. Endophytic fungi Alternaria from B. papyrifera might be promising sources of natural bioactive and novel metabolites. PMID:27001249

  10. Alt a 15 is a new cross-reactive minor allergen of Alternaria alternata.

    PubMed

    Gabriel, M F; Postigo, I; Gutiérrez-Rodríguez, A; Suñén, E; Guisantes, J A; Fernández, J; Tomaz, C T; Martínez, J

    2016-02-01

    Alternaria alternata is one of the most common saprophytes worldwide that is clinically and epidemiologically associated with severe asthma. Therefore, the identification and characterization of all A. alternata allergens are of major clinical importance. This study describes a new cross-reactive A. alternata allergen that was officially named Alt a 15 by the official Allergen Nomenclature Subcommittee. The complete coding region for Alt a 15 was amplified using 5' and 3' rapid amplification of cDNA ends and PCR. The recombinant protein was produced in Escherichia coli as a 65-kDa fusion protein, and the protein sequence exhibits high homology with several important fungal allergens. Immunoblotting analyses revealed that IgE antibodies from A. alternata-sensitized patients (n=59) bound to rAlt a 15 with a prevalence of 10.2%. All patients who presented sIgE to rAlt a 15 were apparently poly-sensitized to A. alternata and C. lunata. The extensive cross-reactivity between A. alternata and C. lunata serine proteases was confirmed using immunoblotting inhibition assays. Overall, Alt a 15 is an important new cross-reactive allergen of A. alternata that explains some allergies to A. alternata without Alt a 1 sensitization and initial diagnostic errors for allergies to Alternaria. This molecule may improve the accuracy of the diagnosis, the understanding, and the management of IgE-mediated fungal diseases. PMID:26395961

  11. Genome sequence of a novel victorivirus identified in the phytopathogenic fungus Alternaria arborescens.

    PubMed

    Komatsu, Ken; Katayama, Yukie; Omatsu, Tsutomu; Mizutani, Tetsuya; Fukuhara, Toshiyuki; Kodama, Motoichiro; Arie, Tsutomu; Teraoka, Tohru; Moriyama, Hiromitsu

    2016-06-01

    Strains of the phytopathogenic fungus Alternaria spp. have been found to contain a variety of double-stranded RNA (dsRNA) elements indicative of mycovirus infection. Here, we report the molecular characterization of a novel dsRNA mycovirus, Alternaria arborescens victorivirus 1 (AaVV1), from A. arborescens, the tomato pathotype of A. alternata. Using next-generation sequencing of dsRNA purified from an A. arborescens strain from the United States of America, we found that the AaVV1 genome is 5203 bp in length and contains two open reading frames (ORF1 and 2) that overlap at the tetranucleotide AUGA. Proteins encoded by ORF1 and ORF2 showed significant similarities to the coat protein (CP) and the RNA-dependent RNA polymerase (RdRp), respectively, of dsRNA mycoviruses of the genus Victorivirus. Pairwise comparisons and phylogenetic analysis of the deduced amino acid sequences of both CP and RdRp indicated that AaVV1 is a member of a distinct species of the genus Victorivirus in the family Totiviridae. PMID:26923927

  12. [Sporogenesis, sporoderm and mature spore ornamentation in Lycopodiaceae].

    PubMed

    Rincon Baron, Edgar Javier; Rolleri, Cristina Hilda; Passarelli, Lilian M; Espinosa Matías, Silvia; Torres, Alba Marina

    2014-09-01

    Studies on reproductive aspects, spore morphology and ultrastructure of Lycopodiaceae are not very common in the scientific literature, and constitute essential information to support taxonomic and systematic relationships among the group. In order to complete existing information, adding new and broader contributions on these topics, a comparative analysis of the sporogenesis ultrastructure, with emphasis on cytological aspects of the sporocyte coat development, tapetum, monoplastidic and polyplastidic meiosis, sporoderm ontogeny and ornamentation of the mature spores, was carried out in 43 taxa of eight genera of the Lycopodiaceae: Austrolycopodium, Diphasium, Diphasiastrum, Huperzia (including Phlegmariurus), Lycopodium, Lycopodiella, Palhinhaea and Pseudolycopodiella growing in the Andes of Colombia and the Neotropics. For this study, the transmission elec- tron microscopy (TEM) samples were collected in Cauca and Valle del Cauca Departments, while most of the spores for scanning electron microscopy (SEM) analysis were obtained from herbarium samples. We followed standard preparation procedures for spore observation by TEM and SEM. Results showed that the sporocyte coat is largely composed by primary wall components; the sporocyte develop much of their metabolic activity in the production of their coat, which is retained until the spores release; protective functions for the diploid cells undergoing meiosis is postulated here for this layer. The abundance of dictyosomes in the sporocyte cytoplasm was related to the formation and development of the sporocyte coat. Besides microtubule activity, the membrane of sporocyte folds, associated with electrodense material, and would early determine the final patterns of spore ornamentation. Monoplastidic condition is common in Lycopodium s.l., whereas polyplastidic condition was observed in species of Huperzia and Lycopodiella s. l. In monoplastidic species, the tapetum presents abun- dant multivesicular bodies, while in

  13. Micromotors to capture and destroy anthrax simulant spores.

    PubMed

    Orozco, Jahir; Pan, Guoqing; Sattayasamitsathit, Sirilak; Galarnyk, Michael; Wang, Joseph

    2015-03-01

    Towards addressing the need for detecting and eliminating biothreats, we describe a micromotor-based approach for screening, capturing, isolating and destroying anthrax simulant spores in a simple and rapid manner with minimal sample processing. The B. globilli antibody-functionalized micromotors can recognize, capture and transport B. globigii spores in environmental matrices, while showing non-interactions with excess of non-target bacteria. Efficient destruction of the anthrax simulant spores is demonstrated via the micromotor-induced mixing of a mild oxidizing solution. The new micromotor-based approach paves a way to dynamic multifunctional systems that rapidly recognize, isolate, capture and destroy biological threats. PMID:25622851

  14. New pressure and temperature effects on bacterial spores

    NASA Astrophysics Data System (ADS)

    Mathys, A.; Heinz, V.; Knorr, D.

    2008-07-01

    The mechanism of inactivation of bacterial spores by heat and pressure is still a matter of discussion. Obviously, the change of the dissociation equilibrium under pressure and temperature plays a dominant role in inactivation of microorganisms. Heat and pressure inactivation of Geobacillus. stearothermophilus spores at different initial pH-values in ACES and phosphate buffer confirmed this view. Thermal inactivation in ACES buffer at 122°C resulted in higher logarithmic reductions. Contrary, after pressure treatment at 900 MPa with 80°C phosphate buffer showed higher inactivation. These results indicated the different dissociation equilibrium shifts in buffer systems by heat and pressure. Due to preparation, storage and handling of highly concentrated spore suspensions the clumping and the formation of aggregates can hardly be avoided. Consequently, the impact of the agglomeration size distribution on the quantitative assessment of G. stearothermophilus spore inactivation was determined by using a three-fold dynamic optical backreflexion measurement. Two limiting cases have been discriminated in mathematical modelling: three dimensional, spherical packing for maximum spore count and two dimensional, circular packing for minimum spore count of a particular agglomerate. Thermal inactivation studies have been carried out in thin glass capillaries, where by using numerical simulations the non isothermal conditions were modelled and taken into account. It is shown that the shoulder formation often found in thermal spore inactivation can sufficiently be described by first-order inactivation kinetics when the agglomeration size is considered. In case of high pressure inactivation agglomerations could be strongly changed by high forces at compression and especially decompression phase. The physiological response of Bacillus licheniformis spores to high pressure was investigated using multiparameter flow cytometry. Spores were treated by high pressure at 150 MPa with 37

  15. Airborne Submillimeter Spectroscopy

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J.

    1998-01-01

    This is the final technical report for NASA-Ames grant NAG2-1068 to Caltech, entitled "Airborne Submillimeter Spectroscopy", which extended over the period May 1, 1996 through January 31, 1998. The grant was funded by the NASA airborne astronomy program, during a period of time after the Kuiper Airborne Observatory was no longer operational. Instead. this funding program was intended to help develop instrument concepts and technology for the upcoming SOFIA (Stratospheric Observatory for Infrared Astronomy) project. SOFIA, which is funded by NASA and is now being carried out by a consortium lead by USRA (Universities Space Research Association), will be a 747 aircraft carrying a 2.5 meter diameter telescope. The purpose of our grant was to fund the ongoing development of sensitive heterodyne receivers for the submillimeter band (500-1200 GHz), using sensitive superconducting (SIS) detectors. In 1997 July we submitted a proposal to USRA to construct a heterodyne instrument for SOFIA. Our proposal was successful [1], and we are now continuing our airborne astronomy effort with funding from USRA. A secondary purpose of the NAG2-1068 grant was to continue the anaIN'sis of astronomical data collected with an earlier instrument which was flown on the NASA Kuiper Airborne Observatory (KAO). The KAO instrument and the astronomical studies which were carried out with it were supported primarily under another grant, NAG2-744, which extended over October 1, 1991 through Januarv 31, 1997. For a complete description of the astronomical data and its anailysis, we refer the reader to the final technical report for NAG2-744, which was submitted to NASA on December 1. 1997. Here we report on the SIS detector development effort for SOFIA carried out under NAG2-1068. The main result of this effort has been the demonstration of SIS mixers using a new superconducting material niobium titanium nitride (NbTiN), which promises to deliver dramatic improvements in sensitivity in the 700

  16. Roles of the Major, Small, Acid-Soluble Spore Proteins and Spore-Specific and Universal DNA Repair Mechanisms in Resistance of Bacillus subtilis Spores to Ionizing Radiation from X Rays and High-Energy Charged-Particle Bombardment▿

    PubMed Central

    Moeller, Ralf; Setlow, Peter; Horneck, Gerda; Berger, Thomas; Reitz, Günther; Rettberg, Petra; Doherty, Aidan J.; Okayasu, Ryuichi; Nicholson, Wayne L.

    2008-01-01

    The role of DNA repair by nonhomologous end joining (NHEJ), homologous recombination, spore photoproduct lyase, and DNA polymerase I and genome protection via α/β-type small, acid-soluble spore proteins (SASP) in Bacillus subtilis spore resistance to accelerated heavy ions (high-energy charged [HZE] particles) and X rays has been studied. Spores deficient in NHEJ and α/β-type SASP were significantly more sensitive to HZE particle bombardment and X-ray irradiation than were the recA, polA, and splB mutant and wild-type spores, indicating that NHEJ provides an efficient DNA double-strand break repair pathway during spore germination and that the loss of the α/β-type SASP leads to a significant radiosensitivity to ionizing radiation, suggesting the essential function of these spore proteins as protectants of spore DNA against ionizing radiation. PMID:18055591

  17. Effects of temperature and desiccation on ex situ conservation of nongreen fern spores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation of the genetic diversity of ferns is limited by the paucity of ex situ spore banks. Conflicting reports of fern spore response to low temperature and moisture impedes establishment of fern spore banks. There is little information available to evaluate longevity of fern spores under dif...

  18. Nonhost-specific phytotoxicity of the polyketide-derived toxin solanapyrone A produced by Ascochyta rabiei and Alternaria solani

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solanapyrone A is a polyketide-derived metabolite produced by Ascochyta rabiei and Alternaria solani, which are the most destructive necrotrophic pathogens of chickpea and potato/tomato, respectively. They belong to the Order Pleosporales within the Class Dothideomycetes, but are phylogenetically di...

  19. Phytotoxin solanapyrone A produced by Ascochyta rabiei and Alternaria solani is nonessential for pathogenicity, but likely plays ecological roles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ascochyta rabiei and Alternaria solani, causal agents of chickpea and potato blights respectively, produce the same phytotoxin solanapyrone A (SolA).The toxicity of SolA to plants has been documented, but its role in pathogenicity has not been investigated. In this study, we generated solanapyrone-d...

  20. Characterization of Alternaria isolates from the infectoria species-group and a new taxon from Arrhenatherum, Pseudoalternaria arrhenatheria sp. nov

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The infectoria species-group within the genus Alternaria was originally conceived by Simmons in 1993 and was based upon common morphological characteristics that included the development of conidial chains with primary, secondary, and tertiary branching resulting in substantial three-dimensional com...

  1. Molecular characterization and detection of mutations associated with resistance to succinate dehydrogenase inhibiting (SDHI) fungicides in Alternaria solani

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early blight, caused by Alternaria solani, is an economically important foliar disease of potato in several production areas of the United States. Few potato cultivars possess resistance to early blight, therefore, the application of fungicides is a primary means of achieving disease control. Previo...

  2. Effects of Alternaria destruens, Glyphosate, and Ammonium Sulfate Individually and Integrated for Control of Dodder (Cuscuta pentagona)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dodder is a serious weed problem in several crops. Its minutely sized, easily dispersed, and highly viable seed makes it difficult to control. Alternaria destruens is the active ingredient in a registered bioherbicide for control of dodder species. In greenhouse studies, the following treatments ...

  3. Survey of Alternaria toxin contamination in food from the German market, using a rapid HPLC-MS/MS approach.

    PubMed

    Hickert, Sebastian; Bergmann, Marian; Ersen, Seyma; Cramer, Benedikt; Humpf, Hans-Ulrich

    2016-02-01

    A HPLC-MS/MS-based method for the quantification of nine mycotoxins produced by fungi of the genus Alternaria in various food matrices was developed. The method relies on a single-step extraction, followed by dilution of the raw extract and direct analysis. In combination with an analysis time per sample of 12 min, the sample preparation is cost-effective and easy to handle. The method covers alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), altenuene (ALT), iso-altenuene (isoALT), tentoxin (TEN), altertoxin-I (ATX-I), and the AAL toxins TA1 and TA2. Some Alternaria toxins which are either not commercially available or very expensive, namely AOH, AME, ALT, isoALT, and ATX-I, were isolated as reference compounds from fungal cultures. The method was extensively validated for tomato products, bakery products, sunflower seeds, fruit juices, and vegetable oils. AOH, AME, TeA, and TEN were found in quantifiable amounts and 92.1% of all analyzed samples (n = 96) showed low level contamination with one or more Alternaria toxins. Based on the obtained results, the average daily exposure to Alternaria toxins in Germany was calculated. PMID:26408172

  4. First Report of a Leaf Spot Caused by Alternaria brassicae on the Invasive Weed Lepidium draba in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A second leaf spot disease on the perennial invasive weed white top, aka hoary cress, was found in a stand of white top in south central Montana. The plant pathogen causing the lesions was identified as the fungus Alternaria brassicae. It was isolated, purified grown on a V-8 agar growth medium and ...

  5. Real-time PCR quantification of the AM-toxin gene and HPLC qualification of toxigenic metabolites from Alternaria species from apples.

    PubMed

    Andersen, Birgitte; Smedsgaard, Jørn; Jørring, Ida; Skouboe, Pernille; Pedersen, Lars Hagsholm

    2006-09-01

    Some Alternaria species are able to produce plant pathogenic as well as toxic metabolites. In both agriculture and the food industry it is important know if toxigenic Alternaria are present to rapidly employ the correct corrective actions. The purpose of this work was to establish a real-time PCR method, which can detect and quantify apple pathogenic and toxigenic Alternaria. An AM-toxin I primer set, which could recognize Alternaria DNA only, was designed by using primers complementary to the AM-toxin I gene. The method could detect small amounts of DNA (4 pg) and still obtain a large dynamic range (4 decades) without interference from apple material. Eight Alternaria isolates were analyzed for the presence of AM-toxin I gene and their production of secondary metabolites. Then analyses showed that all eight isolates contained the AM toxin gene and were able to produce the plant pathogenic tentoxin in addition to AM toxin I. The analyses also showed the production of tenuazonic acid, alternariols, Altenuene, altenusin and/or altertoxin I in pure culture. Analyses of inoculated apples showed that both the AM-toxin gene and alternariol monomethyl ether could be detected. Morphological analyses suggested that the eight Alternaria strains, though they all carried the AM toxin genes, probably belong to different but closely related un-described Alternaria taxa in the A. tenuissima species-group based on morphological and chemical differences. PMID:16890318

  6. Identifying bacterial spores and anthrax hoax materials by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Farquharson, Stuart; Brouillette, Carl R.; Smith, Wayne

    2004-12-01

    The distribution of Bacillus anthracis spores through the US postal system in the autumn of 2001, initiated a secondary form of terror, the mailing of hoax materials. In the past three years nearly 20,000 letters containing harmless powders have been mailed, creating additional anxiety. Thus, there is a need for analyzers that can not only identify anthrax-causing spores to save lives, but also identify hoax materials to eliminate time-consuming and costly shutdowns. Recently, we established that Raman spectroscopy has the ability to identify both Bacilli endospores and hoax materials. Here we present Raman spectra of several Bacilli spores along with the dipicolinate salts, to further define the abilities of this technology to not only identify hoax materials, but also identify spores at the genus and species level.

  7. PHOSPHOLIPIDS IN VEGETATIVE CELLS AND SPORES OF BACILLUS POLYMYXA1

    PubMed Central

    Matches, Jack R.; Walker, Homer W.; Ayres, John C.

    1964-01-01

    Matches, Jack R. (Iowa State University of Science and Technology, Ames), Homer W. Walker, and John C. Ayres. Phospholipids in vegetative cells and spores of Bacillus polymyxa. J. Bacteriol. 87:16–23. 1964.—The same types of phospholipids were recovered from both vegetative cells and spores of Bacillus polymyxa 1A39. Nitrogen-containing phospholipids were identified as phosphatidyl ethanolamine, lysophosphatidyl ethanolamine, lysophosphatidyl serine, and lysolecithin. Acidic phosphatides containing no nitrogen were identified as phosphatidic acid, phosphatidyl glycerol, and a fraction appearing to be bis (phosphatidic) acid. The major phosphatide fraction in both cells and spores was phosphatidyl ethanolamine. Smaller amounts of phosphatidyl glycerol and bis (phosphatidic) acid were present; the other acidic phospholipid components were present only in trace amounts. Heat resistance of the spore as compared to the vegetative cell could not be attributed to a specific phospholipid, since no difference in the type of phospholipids present was observed. PMID:14102851

  8. A versatile nano display platform from bacterial spore coat proteins

    PubMed Central

    Wu, I-Lin; Narayan, Kedar; Castaing, Jean-Philippe; Tian, Fang; Subramaniam, Sriram; Ramamurthi, Kumaran S.

    2015-01-01

    Dormant bacterial spores are encased in a thick protein shell, the ‘coat', which contains ∼70 different proteins. The coat protects the spore from environmental insults, and is among the most durable static structures in biology. Owing to extensive cross-linking among coat proteins, this structure has been recalcitrant to detailed biochemical analysis, so molecular details of how it assembles are largely unknown. Here, we reconstitute the basement layer of the coat atop spherical membranes supported by silica beads to create artificial spore-like particles. We report that these synthetic spore husk-encased lipid bilayers (SSHELs) assemble and polymerize into a static structure, mimicking in vivo basement layer assembly during sporulation in Bacillus subtilis. In addition, we demonstrate that SSHELs may be easily covalently modified with small molecules and proteins. We propose that SSHELs may be versatile display platforms for drugs and vaccines in clinical settings, or for enzymes that neutralize pollutants for environmental remediation. PMID:25854653

  9. Surface Bacterial-Spore Assay Using Tb3+/DPA Luminescence

    NASA Technical Reports Server (NTRS)

    Ponce, Adrian

    2007-01-01

    Equipment and a method for rapidly assaying solid surfaces for contamination by bacterial spores are undergoing development. The method would yield a total (nonviable plus viable) spore count of a surface within minutes and a viable-spore count in about one hour. In this method, spores would be collected from a surface by use of a transparent polymeric tape coated on one side with a polymeric adhesive that would be permeated with one or more reagent(s) for detection of spores by use of visible luminescence. The sticky side of the tape would be pressed against a surface to be assayed, then the tape with captured spores would be placed in a reader that illuminates the sample with ultraviolet light and counts the green luminescence spots under a microscope to quantify the number of bacterial spores per unit area. The visible luminescence spots seen through the microscope would be counted to determine the concentration of spores on the surface. This method is based on the chemical and physical principles of methods described in several prior NASA Tech Briefs articles, including Live/Dead Spore Assay Using DPA-Triggered Tb Luminescence (NPO-30444), Vol. 27, No. 3 (March 2003), page 7a. To recapitulate: The basic idea is to exploit the observations that (1) dipicolinic acid (DPA) is present naturally only in bacterial spores; and (2) when bound to Tb3+ ions, DPA triggers intense green luminescence of the ions under ultraviolet excitation; (3) DPA can be released from the viable spores by using L-alanine to make them germinate; and (4) by autoclaving, microwaving, or sonicating the sample, one can cause all the spores (non-viable as well as viable) to release their DPA. One candidate material for use as the adhesive in the present method is polydimethysiloxane (PDMS). In one variant of the method for obtaining counts of all (viable and nonviable) spores the PDMS would be doped with TbCl3. After collection of a sample, the spores immobilized on the sticky tape surface

  10. Oxidation mechanism of Penicillium digitatum spores through neutral oxygen radicals

    NASA Astrophysics Data System (ADS)

    Hashizume, Hiroshi; Ohta, Takayuki; Takeda, Keigo; Ishikawa, Kenji; Hori, Masaru; Ito, Masafumi

    2014-01-01

    To investigate the inactivation process of Penicillium digitatum spores through neutral oxygen species, the spores were treated with an atmospheric-pressure oxygen radical source and observed in-situ using a fluorescent confocal-laser microscope. The treated spores were stained with two fluorescent dyes, 1,1‧-dioctadecyl-3,3,Y,3‧-tetramethylindocarbocyanine perchlorate (DiI) and diphenyl-1-pyrenylphosphine (DPPP). The intracellular organelles as well as the cell membranes in the spores treated with the oxygen radical source were stained with DiI without a major morphological change of the membranes. DPPP staining revealed that the organelles were oxidized by the oxygen radical treatment. These results suggest that neutral oxygen species, especially atomic oxygen, induce a minor structural change or functional inhibition of cell membranes, which leads to the oxidation of the intracellular organelles through the penetration of reactive oxygen species into the cell.

  11. Simulation modeling of anthrax spore dispersion in a bioterrorism incident.

    PubMed

    Reshetin, Vladimir P; Regens, James L

    2003-12-01

    Recent events have increased awareness of the risk posed by terrorist attacks. Bacillus anthracis has resurfaced in the 21st century as a deadly agent of bioterrorism because of its potential for causing massive civilian casualties. This analysis presents the results of a computer simulation of the dispersion of anthrax spores in a typical 50-story, high-rise building after an intentional release during a bioterrorist incident. The model simulates aerosol dispersion in the case of intensive, small-scale convection, which equalizes the concentration of anthrax spores over the building volume. The model can be used to predict the time interval required for spore dispersion throughout a building after a terrorist attack in a high-rise building. The analysis reveals that an aerosol release of even a relatively small volume of anthrax spores during a terrorist incident has the potential to quickly distribute concentrations that are infectious throughout the building. PMID:14641889

  12. Interplanetary Migration of Eucaryotic Cell, Spore of Schizosaccharomyces Pombe

    NASA Astrophysics Data System (ADS)

    Hayashi, N.; Nosaka, J.; Ando, R.; Hashimoto, H.; Yokobori, S.; Narumi, I.; Nakagawa, K.; Yamagishi, A.; Tohda, H.

    2013-11-01

    The Tanpopo mission to examine possible interplanetary migration of microbes is progressing. Spore of Schizosaccharomyces pombe are considered as the exposed samples. In this paper, results of preliminary experiments for the exposure are shown.

  13. Disinfection of Bacillus spores with acidified nitrite.

    PubMed

    Szabo, Jeffrey G; Adcock, Noreen J; Rice, Eugene W

    2014-10-01

    Disinfecting water generated from a bioterrorism contamination event will require large amounts of disinfectant since the volume of water flushed from a drinking water distribution system or wash water collected from a contaminated outdoor area can accumulate quickly. Commonly used disinfectants may be unavailable in the necessary amounts, so evaluation of alternative disinfectants is needed. This study focuses on disinfection of Bacillus spores in water using acidified nitrite. The effect of varying pH (2 or 3), temperature (5°C or 24°C), nitrite concentration (0.01 or 0.1M), buffer (Butterfields or Phosphate Buffered Saline, PBS) and Bacillus species (B. globigii and B. anthracis Sterne) was evaluated. B. globigii was more resistant to disinfection under all water quality conditions. Disinfection was more effective for B. globigii and B. anthracis Sterne at 0.1M nitrite, pH 2, and 24°C. Disinfection of B. anthracis Sterne was enhanced in low ionic strength Butterfields buffer compared to PBS. PMID:25065806

  14. Fate of ingested Clostridium difficile spores in mice.

    PubMed

    Howerton, Amber; Patra, Manomita; Abel-Santos, Ernesto

    2013-01-01

    Clostridium difficile infection (CDI) is a leading cause of antibiotic-associated diarrhea, a major nosocomial complication. The infective form of C. difficile is the spore, a dormant and resistant structure that forms under stress. Although spore germination is the first committed step in CDI onset, the temporal and spatial distribution of ingested C. difficile spores is not clearly understood. We recently reported that CamSA, a synthetic bile salt analog, inhibits C. difficile spore germination in vitro and in vivo. In this study, we took advantage of the anti-germination activity of bile salts to determine the fate of ingested C. difficile spores. We tested four different bile salts for efficacy in preventing CDI. Since CamSA was the only anti-germinant tested able to prevent signs of CDI, we characterized CamSa's in vitro stability, distribution, and cytotoxicity. We report that CamSA is stable to simulated gastrointestinal (GI) environments, but will be degraded by members of the natural microbiota found in a healthy gut. Our data suggest that CamSA will not be systemically available, but instead will be localized to the GI tract. Since in vitro pharmacological parameters were acceptable, CamSA was used to probe the mouse model of CDI. By varying the timing of CamSA dosage, we estimated that C. difficile spores germinated and established infection less than 10 hours after ingestion. We also showed that ingested C. difficile spores rapidly transited through the GI tract and accumulated in the colon and cecum of CamSA-treated mice. From there, C. difficile spores were slowly shed over a 96-hour period. To our knowledge, this is the first report of using molecular probes to obtain disease progression information for C. difficile infection. PMID:24023628

  15. Architecture and Assembly of the Bacillus subtilis Spore Coat

    PubMed Central

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J.

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of “nanodot” particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  16. Vacuum-induced Mutations In Bacillus Subtilis Spores

    NASA Astrophysics Data System (ADS)

    Munakata, N.; Maeda, M.; Hieda, K.

    During irradiation experiments with vacuum-UV radiation using synchrotron sources, we made unexpected observation that Bacillus subtilis spores of several recombination-deficient strains lost colony-forming ability by the exposure to high vacuum alone. Since this suggested the possible injury in spore DNA, we looked for mutation induction using the spores of strains HA101 (wild-type repair capability) and TKJ6312 (excision and spore repair deficient) that did not lose survivability. It was found that the frequency of nalidixic-acid resistant mutation increased several times in both of these strains by the exposure to high vacuum (10e-4 Pa after 24 hours). The analysis of sequence changes in gyrA gene showed that the majority of mutations carried a unique allele (gyrA12) of tandem double-base substitutions from CA to TT. The observation has been extended to rifampicin resistant mutations, the majority of that carried substitutions from CA to TT or AT in rpoB gene. On the other hand, when the spores of strains PS578 and PS2319 (obtained from P. Setlow) that are defective in a group of small acidic proteins (alpha/beta-type SASP) were similarly treated, none of the mutants analyzed carried such changes. This suggests that the unique mutations might be induced by the interaction of small acidic proteins with spore DNA under forced dehydration. The results indicate that extreme vacuum causes severe damage in spore DNA, and provide additional constraint to the long-term survival of bacterial spores in the space environment.

  17. PHARUS airborne SAR concept

    NASA Astrophysics Data System (ADS)

    Snoeij, Paul; Pouwels, Henk; Koomen, Peter J.; Hoogeboom, Peter

    1995-11-01

    PHARUS (phased array universal SAR) is an airborne SAR concept which is being developed in the Netherlands. The PHARUS system differs from other airborne SARs by the use of a phased array antenna, which provides both for the flexibility in the design as well as for a compact, light-weight instrument that can be carried on small aircraft. The concept allows for the construction of airborne SAR systems on a common generic basis but tailored to specific user needs and can be seen as a preparation for future spaceborne SAR systems using solid state transmitters with electronically steerable phased array antenna. The whole approach is aimed at providing an economic and yet technically sophisticated solution to remote sensing or surveying needs of a specific user. The solid state phased array antenna consists of a collection of radiating patches; the design flexibility for a large part resides in the freedom to choose the number of patches, and thereby the essential radar performance parameters such as resolution and swath width. Another consequence of the use of the phased array antenna is the system's compactness and the possibility to rigidly mount it on a small aircraft. The use of small aircraft of course considerably improves the cost/benefit ratio of the use of airborne SAR. Flight altitude of the system is flexible between about 7,000 and 40,000 feet, giving much operational freedom within the meteo and airspace control limits. In the PHARUS concept the airborne segment is complemented by a ground segment, which consists of a SAR processor, possibly extended by a matching image processing package. (A quick look image is available in real-time on board the aircraft.) The SAR processor is UNIX based and runs on easily available hardware (SUN station). Although the additional image processing software is available, the SAR processing software is nevertheless designed to be able to interface with commercially available image processing software, as well as being able

  18. Generic aspects of the airborne spread of human pathogens indoors and emerging air decontamination technologies.

    PubMed

    Ijaz, M Khalid; Zargar, Bahram; Wright, Kathryn E; Rubino, Joseph R; Sattar, Syed A

    2016-09-01

    Indoor air can be an important vehicle for a variety of human pathogens. This review provides examples of airborne transmission of infectious agents from experimental and field studies and discusses how airborne pathogens can contaminate other parts of the environment to give rise to secondary vehicles leading air-surface-air nexus with possible transmission to susceptible hosts. The following groups of human pathogens are covered because of their known or potential airborne spread: vegetative bacteria (staphylococci and legionellae), fungi (Aspergillus, Penicillium, and Cladosporium spp and Stachybotrys chartarum), enteric viruses (noro- and rotaviruses), respiratory viruses (influenza and coronaviruses), mycobacteria (tuberculous and nontuberculous), and bacterial spore formers (Clostridium difficile and Bacillus anthracis). An overview of methods for experimentally generating and recovering airborne human pathogens is included, along with a discussion of factors that influence microbial survival in indoor air. Available guidelines from the U.S. Environmental Protection Agency and other global regulatory bodies for the study of airborne pathogens are critically reviewed with particular reference to microbial surrogates that are recommended. Recent developments in experimental facilities to contaminate indoor air with microbial aerosols are presented, along with emerging technologies to decontaminate indoor air under field-relevant conditions. Furthermore, the role that air decontamination may play in reducing the contamination of environmental surfaces and its combined impact on interrupting the risk of pathogen spread in both domestic and institutional settings is discussed. PMID:27590695

  19. Airborne radioactive contamination monitoring

    SciTech Connect

    Whitley, C.R.; Adams, J.R.; Bounds, J.A.; MacArthur, D.W.

    1996-03-01

    Current technologies for the detection of airborne radioactive contamination do not provide real-time capability. Most of these techniques are based on the capture of particulate matter in air onto filters which are then processed in the laboratory; thus, the turnaround time for detection of contamination can be many days. To address this shortcoming, an effort is underway to adapt LRAD (Long-Range-Alpha-Detection) technology for real-time monitoring of airborne releases of alpa-emitting radionuclides. Alpha decays in air create ionization that can be subsequently collected on electrodes, producing a current that is proportional to the amount of radioactive material present. Using external fans on a pipe containing LRAD detectors, controlled samples of ambient air can be continuously tested for the presence of radioactive contamination. Current prototypes include a two-chamber model. Sampled air is drawn through a particulate filter and then through the first chamber, which uses an electrostatic filter at its entrance to remove ambient ionization. At its exit, ionization that occurred due to the presence of radon is collected and recorded. The air then passes through a length of pipe to allow some decay of short-lived radon species. A second chamber identical to the first monitors the remaining activity. Further development is necessary on air samples without the use of particulate filtering, both to distinguish ionization that can pass through the initial electrostatic filter on otherwise inert particulate matter from that produced through the decay of radioactive material and to separate both of these from the radon contribution. The end product could provide a sensitive, cost-effective, real-time method of determining the presence of airborne radioactive contamination.

  20. Wet and dry bacterial spore densities determined by buoyant sedimentation.

    PubMed Central

    Tisa, L S; Koshikawa, T; Gerhardt, P

    1982-01-01

    The wet densities of various types of dormant bacterial spores and reference particles were determined by centrifugal buoyant sedimentation in density gradient solutions of three commercial media of high chemical density. With Metrizamide or Renografin, the wet density values for the spores and permeable Sephadex beads were higher than those obtained by a reference direct mass method, and some spore populations were separated into several density bands. With Percoll, all of the wet density values were about the same as those obtained by the direct mass method, and only single density bands resulted. The differences were due to the partial permeation of Metrizamide and Renografin, but not Percoll, into the spores and the permeable Sephadex beads. Consequently, the wet density of the entire spore was accurately represented only by the values obtained with the Percoll gradient and the direct mass method. The dry densities of the spores and particles were determined by gravity buoyant sedimentation in a gradient of two organic solvents, one of high and the other of low chemical density. All of the dry density values obtained by this method were about the same as those obtained by the direct mass method. PMID:6285824

  1. Tip-enhanced Raman scattering of bacillus subtilis spores

    NASA Astrophysics Data System (ADS)

    Rusciano, G.; Zito, G.; Pesce, G.; Sasso, A.; Isticato, R.; Ricca, E.

    2015-07-01

    Understanding of the complex interactions of molecules at biological interfaces is a fundamental issue in biochemistry, biotechnology as well as biomedicine. A plethora of biological processes are ruled by the molecular texture of cellular membrane: cellular communications, drug transportations and cellular recognition are just a few examples of such chemically-mediated processes. Tip-Enhanced Raman Scattering (TERS) is a novel, Raman-based technique which is ideally suited for this purpose. TERS relies on the combination of scanning probe microscopy and Raman spectroscopy. The basic idea is the use of a metalled tip as a sort of optical nano-antenna, which gives place to SERS effect close to the tip end. Herein, we present the application of TERS to analyze the surface of Bacillus subtilis spores. The choice of this biological systems is related to the fact that a number of reasons support the use of spores as a mucosal delivery system. The remarkable and well-documented resistance of spores to various environmental and toxic effects make them clear potentials as a novel, surface-display system. Our experimental outcomes demonstrate that TERS is able to provide a nano-scale chemical imaging of spore surface. Moreover, we demonstrate that TERS allows differentiation between wilde-type spore and genetically modified strains. These results hold promise for the characterization and optimization of spore surface for drug-delivery applications.

  2. Quantification of Nonproteolytic Clostridium botulinum Spore Loads in Food Materials

    PubMed Central

    Barker, Gary C.; Malakar, Pradeep K.; Plowman, June

    2016-01-01

    We have produced data and developed analysis to build representations for the concentration of spores of nonproteolytic Clostridium botulinum in materials that are used during the manufacture of minimally processed chilled foods in the United Kingdom. Food materials are categorized into homogenous groups which include meat, fish, shellfish, cereals, fresh plant material, dairy liquid, dairy nonliquid, mushroom and fungi, and dried herbs and spices. Models are constructed in a Bayesian framework and represent a combination of information from a literature survey of spore loads from positive-control experiments that establish a detection limit and from dedicated microbiological tests for real food materials. The detection of nonproteolytic C. botulinum employed an optimized protocol that combines selective enrichment culture with multiplex PCR, and the majority of tests on food materials were negative. Posterior beliefs about spore loads center on a concentration range of 1 to 10 spores kg−1. Posterior beliefs for larger spore loads were most significant for dried herbs and spices and were most sensitive to the detailed results from control experiments. Probability distributions for spore loads are represented in a convenient form that can be used for numerical analysis and risk assessments. PMID:26729721

  3. Display of native proteins on Bacillus subtilis spores.

    PubMed

    Pan, Jae-Gu; Choi, Soo-Keun; Jung, Heung-Chae; Kim, Eui-Joong

    2014-09-01

    In principle, protein display is enabled by fusing target proteins to naturally secreted, surface-anchored protein motifs. In this work, we developed a method of native protein display on the Bacillus spore surface that obviates the need to construct fusion proteins to display a motif. Spore coat proteins are expressed in the mother cell compartment and are subsequently assembled and deposited on the surface of spores. Therefore, target proteins overexpressed in the mother cell compartment during the late sporulation phase were expected to be targeted and displayed on the spore surface. As a proof of principle, we demonstrated the display of carboxymethylcellulase (CMCase) in its native form on the spore surface. The target protein, CMCase, was expressed under the control of the cry1Aa promoter, which is controlled by σ(E) and σ(K) and is expressed in the mother cell compartment. The correct display was confirmed using enzyme activity assays, flow cytometry, and immunogold electron microscopy. In addition, we demonstrated the display of a β-galactosidase tetramer and confirmed its correct display using enzyme activity assays and protein characterization. This native protein display system, combined with the robust nature of Bacillus spores, will broaden the range of displayable target proteins. Consequently, the applications of display technology will be expanded, including high-throughput screening, vaccines, biosensors, biocatalysis, bioremediation, and other innovative bioprocesses. PMID:25168353

  4. Infectivity of microsporidia spores stored in water at environmental temperatures.

    PubMed

    Li, X; Palmer, R; Trout, J M; Fayer, R

    2003-02-01

    To determine how long waterborne spores of Encephalitozoon cuniculi, E. hellem, and E. intestinalis could survive at environmental temperatures, culture-derived spores were stored in water at 10, 15, 20, 25, and 30 C and tested for infectivity in monolayer cultures of Madin Darby bovine kidney (MDBK) cells. At 10 C, spores of E. intestinalis were still infective after 12 mo, whereas those of E. hellem and E. cuniculi were infective for 9 and 3 mo, respectively. At 15 C, spores of the same species remained infective for 10, 6, and 2 mo, and at 20 C, for 7, 5, and 1 mo, respectively. At 25 C, spores of E. intestinalis and E. hellem were infective for 3 mo, but those of E. cuniculi were infective for only 3 wk. At 30 C, the former 2 species were infective for 3 wk and 1 mo, respectively, and the latter species for only 1 wk. These findings indicate that spores of different species of Encephalitozoon differ in their longevity and temperature tolerance, but at temperatures from 10 to 30 C, all 3 have the potential to remain infective in the environment long enough to become widely dispersed. PMID:12659327

  5. Infectivity of microsporidia spores stored in seawater at environmental temperatures.

    PubMed

    Fayer, R

    2004-06-01

    To determine how long spores of Encephalitozoon cuniculi, E. hellem, and E. intestinalis remain viable in seawater at environmental temperatures, culture-derived spores were stored in 10, 20, and 30 ppt artificial seawater at 10 and 20 C. At intervals of 1, 2, 4, 8, and 12 wk, spores were tested for infectivity in monolayer cultures of Madin Darby bovine kidney cells. Spores of E. hellem appeared the most robust, some remaining infectious in 30 ppt seawater at 10 C for 12 wk and in 30 ppt seawater at 20 C for 2 wk. Those of E. intestinalis were slightly less robust, remaining infectious in 30 ppt seawater at 10 and 20 C for 1 and 2 wk, respectively. Spores of E. cuniculi remained infectious in 10 ppt seawater at 10 and 20 C for 2 wk but not at higher salinities. These findings indicate that the spores of the 3 species of Encephalitozoon vary in their ability to remain viable when exposed to a conservative range of salinities and temperatures found in nature but, based strictly on salinity and temperature, can potentially remain infectious long enough to become widely dispersed in estuarine and coastal waters. PMID:15270118

  6. Small acid soluble proteins for rapid spore identification.

    SciTech Connect

    Branda, Steven S.; Lane, Todd W.; VanderNoot, Victoria A.; Jokerst, Amanda S.

    2006-12-01

    This one year LDRD addressed the problem of rapid characterization of bacterial spores such as those from the genus Bacillus, the group that contains pathogenic spores such as B. anthracis. In this effort we addressed the feasibility of using a proteomics based approach to spore characterization using a subset of conserved spore proteins known as the small acid soluble proteins or SASPs. We proposed developing techniques that built on our previous expertise in microseparations to rapidly characterize or identify spores. An alternative SASP extraction method was developed that was amenable to both the subsequent fluorescent labeling required for laser-induced fluorescence detection and the low ionic strength requirements for isoelectric focusing. For the microseparations, both capillary isoelectric focusing and chip gel electrophoresis were employed. A variety of methods were evaluated to improve the molecular weight resolution for the SASPs, which are in a molecular weight range that is not well resolved by the current methods. Isoelectric focusing was optimized and employed to resolve the SASPs using UV absorbance detection. Proteomic signatures of native wild type Bacillus spores and clones genetically engineered to produce altered SASP patterns were assessed by slab gel electrophoresis, capillary isoelectric focusing with absorbance detection as well as microchip based gel electrophoresis employing sensitive laser-induced fluorescence detection.

  7. Infrared Signatures to Discriminate Viability of Autoclaved Bacillus Spores

    SciTech Connect

    Schneider, Matthew D.; Valentine, Nancy B.; Johnson, Timothy J.

    2011-10-06

    Optical methods can offer good sensitivity for detecting small amounts of chemicals and biologicals, and as these methods mature, are some of the few techniques that can offer true standoff detection. For detection of biological species, determining the viability is clearly important: Certain species of gram-positive bacteria are capable of forming endospores, specialized structures that arise when living conditions become unfavorable or little growth medium is available, being resistant to many chemicals as well as changes in heat or pH. Such spores can remain dormant from months to years until more favorable conditions arise, resulting in germination back to the vegetative state. This persistence characteristic of bacterial spores allows for contamination of a surface (e.g. food or medical equipment) even after the surface has been nominally cleaned. Bacterial spores have also been used as biological weapons, as in the case with B. anthracis. Thus, rapid analysis to determine a spore's viability in a given environment or after attempts to sterilize a given environment is crucial. The increasing availability of portable spectrometers may provide a key to such rapid onsite analysis. The present study was designed to determine whether infrared spectroscopy may be used to differentiate between viable vs. dead B. subtilis and B. atrophaeus spores. Preliminary results show that the reproducible differences in the IR signatures can be used to identify viable vs. autoclaved (dead) B. subtilis and B. atrophaeus bacterial spores.

  8. Lipids stimulate spore germination in the entomopathogenic ascomycete Ascosphaera aggregata.

    PubMed

    James, R R; Buckner, J S

    2004-10-01

    The alfalfa leafcutting bee (Megachile rotundata) is solitary and managed on a large scale for pollination of alfalfa seed crops. The bees nest in holes drilled in wood or polystyrene blocks, and their larvae are highly prone to a fungal disease called chalkbrood. The most prevalent form of chalkbrood is caused by Ascosphaera aggregata, but this ascomycete is difficult to culture. Hyphae will grow on standard fungal media, but spore germination is difficult to achieve and highly variable. We found that germination can be enhanced with oils. Lipids derived from plants and bee larvae increased germination from 50% (without oil) to 75-85% (with oil). Percent germination was significantly greater in the presence of lipids but germination was not significantly different when different oils, including mineral oil, were used. A. aggregata spores oriented along the oil-aqueous interface in the broth in a polar fashion, with swelling and germ tube formation always occurring into the aqueous portion of the broth. The other half of the spore tended to attach to a lipid droplet, where it remained, without swelling, during germ tube formation. The physical attachment of spores to the oil-aqueous interface is what most probably stimulates spore germination, as opposed to some nutritional stimulation. However, further research is needed to determine if and where the spores encounter such an interface when germinating in the host gut, where germination normally occurs. PMID:15645171

  9. Survival of bacterial and mold spores in air filter media

    NASA Astrophysics Data System (ADS)

    Maus, R.; Goppelsröder, A.; Umhauer, H.

    The present study deals with the survival of bacterial and mold spores ( B. subtilis, A. niger) in new and used air filter media. In an filtration test unit samples of different filter media were challenged with specific microbial aerosols and the viability or survival of the microorganisms collected in the filter media was studied. No notable decline or increase in the viability of B. subtilis in new or used filter samples was observed within 5 days. No differences were observed when filter media were either continuously exposed to air flow or stored under static conditions. No influence of relative humidity (RH=30-85%) on the viability of B. subtilis spores was detected as well. Under ideal humidity conditions (RH>98%) no bacterial growth occurred within all the investigated filter media which is due to the lack of nutrients. Similar results were obtained when employing A. niger spores at low relative humidities (RH<35%). However, in two new filter media the viability declined notably at high relative humidity (RH>85%). This trend is attributed to the combined effect of spore rehydration and diffusion of fiber substances into the spores which rendered the spores prone to air flow and air toxics. Under static conditions in a climatic chamber (RH>98%) abundant mold growth occurred in two filter media. The results indicate that atmospheric dust deposited in air filters may serve as nutrient for molds if humidity is sufficient and filters are not exposed to an air flow.

  10. Quantification of Nonproteolytic Clostridium botulinum Spore Loads in Food Materials.

    PubMed

    Barker, Gary C; Malakar, Pradeep K; Plowman, June; Peck, Michael W

    2016-01-01

    We have produced data and developed analysis to build representations for the concentration of spores of nonproteolytic Clostridium botulinum in materials that are used during the manufacture of minimally processed chilled foods in the United Kingdom. Food materials are categorized into homogenous groups which include meat, fish, shellfish, cereals, fresh plant material, dairy liquid, dairy nonliquid, mushroom and fungi, and dried herbs and spices. Models are constructed in a Bayesian framework and represent a combination of information from a literature survey of spore loads from positive-control experiments that establish a detection limit and from dedicated microbiological tests for real food materials. The detection of nonproteolytic C. botulinum employed an optimized protocol that combines selective enrichment culture with multiplex PCR, and the majority of tests on food materials were negative. Posterior beliefs about spore loads center on a concentration range of 1 to 10 spores kg(-1). Posterior beliefs for larger spore loads were most significant for dried herbs and spices and were most sensitive to the detailed results from control experiments. Probability distributions for spore loads are represented in a convenient form that can be used for numerical analysis and risk assessments. PMID:26729721

  11. Airborne Raman lidar

    NASA Astrophysics Data System (ADS)

    Heaps, Wm. S.; Burris, J.

    1996-12-01

    We designed and tested an airborne lidar system using Raman scattering to make simultaneous measurements of methane, water vapor, and temperature in a series of flights on a NASA-operated C-130 aircraft. We present the results for methane detection, which show that the instrument has the requisite sensitivity to atmospheric trace gases. Ultimately these measurements can be used to examine the transport of chemically processed air from within the polar vortex to mid-latitudinal regions and the exchange of stratospheric air between tropical and mid-latitudinal regions.

  12. Airborne Oceanographic Lidar System

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The Airborne Oceanographic Lidar (AOL), a spatially scanning range-gated device installed on board a NASA C-54 aircraft, is described. The AOL system is capable of measuring topographical relief or water depth (bathymetry) with a range resolution of plus or minus 0.3 m in the vertical dimension. The system may also be used to measure fluorescent spectral signatures from 3500 to 8000 A with a resolution of 100 A. Potential applications of the AOL, including sea state measurements, water transparency assessments, oil spill identification, effluent identification and crop cover assessment are also mentioned.

  13. Influence of negative pressurization on airborne microbial and radon levels

    SciTech Connect

    Kalliokoski, P.; Korhonen, P.; Kokotti, H.; Pasanen, A.L.; Rautiala, S.; Rantamaeki, J.

    1999-07-01

    The negative pressure inside a building is the main driving force for the entry of both radon and fungal spores. This study was conducted to test the suitability of depressurization to facilitate simultaneously the detection of fungal growth within the lower parts of building envelope and the risk of radon entry. Pressure difference was increased in three steps to 24--28 Pa in two wooden buildings known to suffer from long-term water damages. At the end, pulses of negative pressure were generated. Airborne viable fungal counts, radon and particle counts were followed during the tests together with the ventilation rate and particle count. The absolute concentrations of the impurities studied did not increase significantly or even decreased during the tests due to enhanced ventilation. However, when the increase in the ventilation rate was taken into consideration it was found that the entry rate of all the contaminants increased. The changes were larger in the tighter building where the radon entry rate increased systematically with the pressure difference reaching finally 13.8-fold level compared to the initial value. In the less tight building, the corresponding highest radon entry rate ratio was 9.5. Very large increases, up to 42-fold, were observed in the viable spore count ratio in the tighter building during the tests. In the leaky building, the changes were again considerably smaller; the maximum ratio was 4.2. Increases in particle emissions were smaller than those observed in fungal counts. The pulses were less effective than continuous depressurization. The results show that negative pressurization can be used to increase the release of fungal spores in order to detect hidden fungal growth. This kind of test is especially effective if there are no major leaks in the clean part of the building envelope. The method allows simultaneous rapid checking of need for radon mitigation.

  14. IMMUNOCYTOCHEMICAL LOCALIZATION OF STACHYLYSIN IN STACHYBOTRYS CHARTARUM SPORES AND SPORE-IMPACTED MOUSE AND RAT LUNG TISSUES

    EPA Science Inventory

    Stachylysin is a proteinaceous hemolytic agent that is producted by S. chartarum. Stachylysin was found, using immunohistochemistical and immunocytochemical methods, to be localized in S. chartarum spores/mycelia primarily in the inner wall suggesting that it is constitutively ...

  15. UV-Photobiology of bacterial spores in space

    NASA Astrophysics Data System (ADS)

    Horneck, Gerda; Douki, Thierry; Cadet, Jean; Panitz, Corinna; Rabbow, Elke; Moeller, Ralf; Rettberg, Petra

    The vast, cold and radiation filled regimes of outer space present on one hand an environmental challenge for any form of terrestrial life; on the other hand they constitute a unique platform for astrobiology research. Major environmental parameters of space that are of interest to astrobiology are (i) space vacuum, (ii) solar electromagnetic radiation, above all the high energy UV radiation, (iii) galactic cosmic radiation, (iv) extreme temperature fluctuations, and (v) microgravity. Exposure facilities on board of Earth orbiting satellites and the International Space Station (ISS) have provided unique opportunities to study biological and chemical processes in response to those parameters directly in space. Endospores of Bacillus spp., especially B. subtilis, characterized by an extreme resistance to environmental insults and an incredible longevity have served as experimental models in studies on (i) the role of the ozone layer in protecting our biosphere; (ii) the likelihood of the interplanetary transfer of life via meteorites, i.e. the hypothesis of lithopanspermia; (iii) the habitability of Mars; (iv) the need for planetary protection measures; and (v) the molecular mechanisms underlying the extreme lethality of solar extraterrestrial UV-radiation. Role of the ozone layer in protecting our biosphere: Using solar extraterrestrial UV radiation and a set of optical filters, the terrestrial UV radiation climate at different ozone concentration was simulated and the biologically effective irradiance was measured with B. subtilis spores immobilized in a biofilm. With decreasing (simulated) ozone concentrations the biologically effective solar irradiance strongly increased by nearly 1000-fold for early Earth conditions before the ozone layer was built up. Likelihood of lithopanspermia: In an impact-driven scenario of lithopanspermia, rock-dwelling microorganisms - after being ejected from a planet - may wander through space for extended periods of time before being

  16. Airborne concentrations of peanut protein.

    PubMed

    Johnson, Rodney M; Barnes, Charles S

    2013-01-01

    Food allergy to peanut is a significant health problem, and there are reported allergic reactions to peanuts despite not eating or having physical contact with peanuts. It is presumed that an allergic reaction may have occurred from inhalation of airborne peanut allergens. The purpose of this study was to detect the possible concentrations of airborne peanut proteins for various preparations and during specific activities. Separate Ara h 1 and Ara h 2 monoclonal enzyme-linked immunosorbent assays and a polyclonal sandwich enzyme immunoassay for peanuts were used to detect the amount of airborne peanut protein collected using a Spincon Omni 3000 air collector (Sceptor Industries, Inc., Kansas City, MO) under different peanut preparation methods and situations. Air samples were measured for multiple peanut preparations and scenarios. Detectable amounts of airborne peanut protein were measured using a whole peanut immunoassay when removing the shells of roasted peanut. No airborne peanut allergen (Ara h 1 or Ara h 2) or whole peanut protein above the LLD was measured in any of the other peanut preparation collections. Ara h 1, Ara h 2, and polyclonal peanut proteins were detected from water used to boil peanuts. Small amounts of airborne peanut protein were detected in the scenario of removing shells from roasted peanuts; however, Ara h 1 and Ara h 2 proteins were unable to be consistently detected. Although airborne peanut proteins were detected, the concentration of airborne peanut protein that is necessary to elicit a clinical allergic reaction is unknown. PMID:23406937

  17. Airborne ballistic camera tracking systems

    NASA Technical Reports Server (NTRS)

    Redish, W. L.

    1976-01-01

    An operational airborne ballistic camera tracking system was tested for operational and data reduction feasibility. The acquisition and data processing requirements of the system are discussed. Suggestions for future improvements are also noted. A description of the data reduction mathematics is outlined. Results from a successful reentry test mission are tabulated. The test mission indicated that airborne ballistic camera tracking systems are feasible.

  18. Characterizing and handling different kinds of AM fungal spores in the rhizosphere.

    PubMed

    Sun, Xueguang; Hu, Wentao; Tang, Ming; Chen, Hui

    2016-06-01

    Spores are important propagules as well as the most reliable species-distinguishing traits of arbuscular mycorrhizal (AM) fungi. During surveys of AM fungal communities, spore enumeration and spore identification are frequently conducted, but generally little attention is given to the age and viability of the spores. In this study, AM fungal spores in the rhizosphere were characterized as live or dead by vital staining and by performing a germination assay. A considerable proportion of the spores in the rhizosphere were dead despite their intact appearance. Furthermore, morphological and molecular analyses of spores to determine species identity revealed that both viable spores and dead spores with contents were identified. The accurate identification of spores at different developmental stages on the basis of morphology requires considerable experience. Our findings suggest that surveys of AM fungal communities based on spore enumeration and morphological and molecular identification are likely to be inaccurate, primarily because of the large proportion of dead spores in the rhizosphere. A viability check is recommended prior to spore molecular identification, and the use of trap cultures would give more reliable morphological identification results. We show that the abundance and activity of AM fungi in the rhizosphere can be determined by calculating the density of viable spores and the density of spores that could germinate. The adoption of these methods should provide a more reliable basis for further AM fungal community analysis. PMID:27116963

  19. Analysis of the Loss in Heat and Acid Resistance during Germination of Spores of Bacillus Species

    PubMed Central

    Luu, Stephanie

    2014-01-01

    A major event in the nutrient germination of spores of Bacillus species is release of the spores' large depot of dipicolinic acid (DPA). This event is preceded by both commitment, in which spores continue through germination even if germinants are removed, and loss of spore heat resistance. The latter event is puzzling, since spore heat resistance is due largely to core water content, which does not change until DPA is released during germination. We now find that for spores of two Bacillus species, the early loss in heat resistance during germination is most likely due to release of committed spores' DPA at temperatures not lethal for dormant spores. Loss in spore acid resistance during germination also paralleled commitment and was also associated with the release of DPA from committed spores at acid concentrations not lethal for dormant spores. These observations plus previous findings that DPA release during germination is preceded by a significant release of spore core cations suggest that there is a significant change in spore inner membrane permeability at commitment. Presumably, this altered membrane cannot retain DPA during heat or acid treatments innocuous for dormant spores, resulting in DPA-less spores that are rapidly killed. PMID:24563034

  20. Improvement of Biological Indicators by Uniformly Distributing Bacillus subtilis Spores in Monolayers To Evaluate Enhanced Spore Decontamination Technologies.

    PubMed

    Raguse, Marina; Fiebrandt, Marcel; Stapelmann, Katharina; Madela, Kazimierz; Laue, Michael; Lackmann, Jan-Wilm; Thwaite, Joanne E; Setlow, Peter; Awakowicz, Peter; Moeller, Ralf

    2016-04-01

    Novel decontamination technologies, including cold low-pressure plasma and blue light (400 nm), are promising alternatives to conventional surface decontamination methods. However, the standardization of the assessment of such sterilization processes remains to be accomplished. Bacterial endospores of the genera Bacillus and Geobacillus are frequently used as biological indicators (BIs) of sterility. Ensuring standardized and reproducible BIs for reliable testing procedures is a significant problem in industrial settings. In this study, an electrically driven spray deposition device was developed, allowing fast, reproducible, and homogeneous preparation of Bacillus subtilis 168 spore monolayers on glass surfaces. A detailed description of the structural design as well as the operating principle of the spraying device is given. The reproducible formation of spore monolayers of up to 5 × 10(7) spores per sample was verified by scanning electron microscopy. Surface inactivation studies revealed that monolayered spores were inactivated by UV-C (254 nm), low-pressure argon plasma (500 W, 10 Pa, 100 standard cubic cm per min), and blue light (400 nm) significantly faster than multilayered spores were. We have thus succeeded in the uniform preparation of reproducible, highly concentrated spore monolayers with the potential to generate BIs for a variety of nonpenetrating surface decontamination techniques. PMID:26801572

  1. Airborne transmission of lyssaviruses.

    PubMed

    Johnson, N; Phillpotts, R; Fooks, A R

    2006-06-01

    In 2002, a Scottish bat conservationist developed a rabies-like disease and subsequently died. This was caused by infection with European bat lyssavirus 2 (EBLV-2), a virus closely related to Rabies virus (RABV). The source of this infection and the means of transmission have not yet been confirmed. In this study, the hypothesis that lyssaviruses, particularly RABV and the bat variant EBLV-2, might be transmitted via the airborne route was tested. Mice were challenged via direct introduction of lyssavirus into the nasal passages. Two hours after intranasal challenge with a mouse-adapted strain of RABV (Challenge Virus Standard), viral RNA was detectable in the tongue, lungs and stomach. All of the mice challenged by direct intranasal inoculation developed disease signs by 7 days post-infection. Two out of five mice challenged by direct intranasal inoculation of EBLV-2 developed disease between 16 and 19 days post-infection. In addition, a simple apparatus was evaluated in which mice could be exposed experimentally to infectious doses of lyssavirus from an aerosol. Using this approach, mice challenged with RABV, but not those challenged with EBLV-2, were highly susceptible to infection by inhalation. These data support the hypothesis that lyssaviruses, and RABV in particular, can be spread by airborne transmission in a dose-dependent manner. This could present a particular hazard to personnel exposed to aerosols of infectious RABV following accidental release in a laboratory environment. PMID:16687600

  2. Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila.

    PubMed

    Andersen, Birgitte; Dongo, Anita; Pryor, Barry M

    2008-02-01

    Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species. The purpose of the present study was to describe the methodology behind metabolite profiling in chemotaxonomy using A. dauci, A. porri, A. solani, and A. tomatophila strains as examples of the group. The results confirmed that A. dauci, A. solani, and A. tomatophila are three distinct species each with their own specific metabolite profiles, and that A. solani and A. tomatophila both produce altersolanol A, altertoxin I, and macrosporin. By using automated chemical image analysis and other multivariate statistic analyses, three sets of species-specific metabolites could be selected, one each for A. dauci, A. solani, and A. tomatophila. PMID:18262401

  3. Fungal Spores Viability on the International Space Station

    NASA Astrophysics Data System (ADS)

    Gomoiu, I.; Chatzitheodoridis, E.; Vadrucci, S.; Walther, I.; Cojoc, R.

    2016-04-01

    In this study we investigated the security of a spaceflight experiment from two points of view: spreading of dried fungal spores placed on the different wafers and their viability during short and long term missions on the International Space Station (ISS). Microscopic characteristics of spores from dried spores samples were investigated, as well as the morphology of the colonies obtained from spores that survived during mission. The selected fungal species were: Aspergillus niger, Cladosporium herbarum, Ulocladium chartarum, and Basipetospora halophila. They have been chosen mainly based on their involvement in the biodeterioration of different substrate in the ISS as well as their presence as possible contaminants of the ISS. From biological point of view, three of the selected species are black fungi, with high melanin content and therefore highly resistant to space radiation. The visual inspection and analysis of the images taken before and after the short and the long term experiments have shown that all biocontainers were returned to Earth without damages. Microscope images of the lids of the culture plates revealed that the spores of all species were actually not detached from the surface of the wafers and did not contaminate the lids. From the adhesion point of view all types of wafers can be used in space experiments, with a special comment on the viability in the particular case of iron wafers when used for spores that belong to B. halophila (halophilic strain). This is encouraging in performing experiments with fungi without risking contamination. The spore viability was lower in the experiment for long time to ISS conditions than that of the short experiment. From the observations, it is suggested that the environment of the enclosed biocontainer, as well as the species'specific behaviour have an important effect, reducing the viability in time. Even the spores were not detached from the surface of the wafers, it was observed that spores used in the

  4. Enhancement of the citrus immune system provides effective resistance against Alternaria brown spot disease.

    PubMed

    Llorens, Eugenio; Fernández-Crespo, Emma; Vicedo, Begonya; Lapeña, Leonor; García-Agustín, Pilar

    2013-01-15

    In addition to basal defense mechanisms, plants are able to develop enhanced defense mechanisms such as induced resistance (IR) upon appropriate stimulation. We recently described the means by which several carboxylic acids protect Arabidopsis and tomato plants against fungi. In this work, we demonstrate the effectiveness of hexanoic acid (Hx) in the control of Alternaria brown spot (ABS) disease via enhancement of the immune system of Fortune mandarin. The application of 1mM Hx in irrigation water to 2-year-old Fortune plants clearly reduced the incidence of the disease and led to smaller lesions. We observed that several of the most important mechanisms involved in induced resistance were affected by Hx application. Our results demonstrate enhanced callose deposition in infected plants treated with Hx, which suggests an Hx priming mechanism. Plants treated with the callose inhibitor 2-DDG were more susceptible to the fungus. Moreover, polygalacturonase-inhibiting protein (PGIP) gene expression was rapidly and significantly upregulated in treated plants. However, treatment with Hx decreased the levels of reactive oxygen species (ROS) in infected plants. Hormonal and gene analyses revealed that the jasmonic acid (JA) pathway was activated due to a greater accumulation of 12-oxo-phytodienoic acid (OPDA) and JA along with a rapid accumulation of JA-isoleucine (JA-Ile). Furthermore, we observed a more rapid accumulation of abscisic acid (ABA), which could act as a positive regulator of callose deposition. Thus, our results support the hypothesis that both enhanced physical barriers and the JA signaling pathway are involved in hexanoic acid-induced resistance (Hx-IR) to Alternaria alternata. PMID:23260526

  5. Substrates and enzyme activities related to biotransformation of resveratrol from phenylalanine by Alternaria sp. MG1.

    PubMed

    Zhang, Jinhua; Shi, Junling; Liu, Yanlin

    2013-12-01

    To identify the substrates and enzymes related to resveratrol biosynthesis in Alternaria sp. MG1, different substrates were used to produce resveratrol, and their influence on resveratrol production was analyzed using high performance liquid chromatography (HPLC). Formation of resveratrol and related intermediates was identified using mass spectrum. During the biotransformation, activities of related enzymes, including phenylalanine ammonia-lyase (PAL), trans-cinnamate 4-hydroxylase (C4H), and 4-coumarate-CoA ligase (4CL), were analyzed and tracked. The reaction system contained 100 mL 0.2 mol/L phosphate buffer (pH 6.5), 120 g/L Alternaria sp. MG1 cells, 0.1 g/L MgSO₄, and 0.2 g/L CaSO₄ and different substrates according to the experimental design. The biotransformation was carried out for 21 h at 28 °C and 120 rpm. Resveratrol formation was identified when phenylalanine, tyrosine, cinnamic acid, and p-coumaric acid were separately used as the only substrate. Accumulation of cinnamic acid, p-coumaric acid, and resveratrol and the activities of PAL, C4H, and 4CL were identified and changed in different trends during transformation with phenylalanine as the only substrate. The addition of carbohydrates and the increase of phenylalanine concentration promoted resveratrol production and yielded the highest value (4.57 μg/L) when 2 g/L glucose, 1 g/L cyclodextrin, and phenylalanine (4.7 mmol/L) were used simultaneously. PMID:24068334

  6. Yield loss assessment due to Alternaria blight and its management in linseed.

    PubMed

    Singh, R B; Singh, H K; Parmar, Arpita

    2014-04-01

    Field experiments were conducted during 2010-11 and 2011-12 to assess the yield losses due to Alternaria blight disease caused by Alternaria lini and A. linicola in recently released cultivars and their management with the integration of Trichoderma viride, fungicides and plant extract. Disease severity on leaves varied from 41.07% (Parvati) to 65.01% (Chambal) while bud damage per cent ranged between 23.56% (Shekhar) to 46.12% (T-397), respectively in different cultivars. Maximum yield loss of 58.44% was recorded in cultivar Neelum followed by Parvati (55.56%), Meera (55.56%) and Chambal (51.72%), respectively while minimum loss was recorded in Kiran (19.99%) and Jeevan (22.22%). Minimum mean disease severity (19.47%) with maximum disease control (69.74%) was recorded with the treatment: seed treatment (ST) with vitavax power (2 g kg(-1) seed) + 2 foliar sprays (FS) of Saaf (a mixture of carbendazim+mancozeb) 0.2% followed by ST with Trichoderma viride (4g kg(-1) seed) + 2 FS of Saaf (0.2%). Minimum bud damage (13.75%) with maximum control (60.94%) was recorded with treatment of ST with vitavax power+2 FS of propiconazole (0.2%). Maximum mean seed yield (1440 kg ha(-1)) with maximum net return (Rs. 15352/ha) and benefit cost ratio (1:11.04) was obtained with treatment ST with vitavax power + 2 FS of Neem leaf extract followed by treatment ST with vitavax power+2 FS of Saaf (1378 kg ha(-1)). PMID:25911838

  7. Virulence Plasmids of Spore-Forming Bacteria.

    PubMed

    Adams, Vicki; Li, Jihong; Wisniewski, Jessica A; Uzal, Francisco A; Moore, Robert J; McClane, Bruce A; Rood, Julian I

    2014-12-01

    Plasmid-encoded virulence factors are important in the pathogenesis of diseases caused by spore-forming bacteria. Unlike many other bacteria, the most common virulence factors encoded by plasmids in Clostridium and Bacillus species are protein toxins. Clostridium perfringens causes several histotoxic and enterotoxin diseases in both humans and animals and produces a broad range of toxins, including many pore-forming toxins such as C. perfringens enterotoxin, epsilon-toxin, beta-toxin, and NetB. Genetic studies have led to the determination of the role of these toxins in disease pathogenesis. The genes for these toxins are generally carried on large conjugative plasmids that have common core replication, maintenance, and conjugation regions. There is considerable functional information available about the unique tcp conjugation locus carried by these plasmids, but less is known about plasmid maintenance. The latter is intriguing because many C. perfringens isolates stably maintain up to four different, but closely related, toxin plasmids. Toxin genes may also be plasmid-encoded in the neurotoxic clostridia. The tetanus toxin gene is located on a plasmid in Clostridium tetani, but the botulinum toxin genes may be chromosomal, plasmid-determined, or located on bacteriophages in Clostridium botulinum. In Bacillus anthracis it is well established that virulence is plasmid determined, with anthrax toxin genes located on pXO1 and capsule genes on a separate plasmid, pXO2. Orthologs of these plasmids are also found in other members of the Bacillus cereus group such as B. cereus and Bacillus thuringiensis. In B. thuringiensis these plasmids may carry genes encoding one or more insecticidal toxins. PMID:26104459

  8. Incorporating sweeps and ejections into Lagrangian stochastic models of spore trajectories within plant canopy turbulence: modeled contact distributions are heavy-tailed.

    PubMed

    Reynolds, A M

    2012-11-01

    ABSTRACT The turbulent dispersal of fungal spores within plant canopies is very different from that within atmospheric boundary-layers and closely analogous to dispersal within turbulent mixing-layers. The process is dominated by the presence of large coherent flow structures, high-velocity downdrafts (sweeps) and updrafts (ejections), that punctuate otherwise quiescent flow. Turbulent dispersion within plant canopies is best predicted by Lagrangian stochastic (particle-tracking) models because other approaches (e.g., diffusion models and similarity theory) are either inappropriate or invalid. Nonetheless, attempts to construct such models have not been wholly successful. Accounting for sweeps and ejections has substantially worsened rather than improved model agreement with experimental dispersion data. Here we show how this long-standing difficulty with the formulation of Lagrangian stochastic models can be overcome. The new model is shown to be in good agreement with data from a carefully controlled, well-documented wind-tunnel study of scalar dispersion within plant canopy turbulence. Equally good agreement with this data is obtained using Thomson's (1987) Gaussian model. This bolsters confidence in the application of this simple model to the prediction of spore dispersal within plant canopy turbulence. Contact distributions-the probability distribution function for the distance of viable fungal spore movement until deposition-are predicted to have "heavy" inverse power-law tails. It is known that heavy-tailed contact distributions also characterize the dispersal of spores which pass through the canopy turbulence and enter into the overlying atmospheric boundary-layer. Plant disease epidemics due to the airborne dispersal of fungal spores are therefore predicted to develop as accelerating waves over a vast range of scales-from the within field scale to intercontinental scales. This prediction is consistent with recent analyses of field and historical data for

  9. IL-33 and thymic stromal lymphopoietin mediate immune pathology in response to chronic airborne allergen exposure.

    PubMed

    Iijima, Koji; Kobayashi, Takao; Hara, Kenichiro; Kephart, Gail M; Ziegler, Steven F; McKenzie, Andrew N; Kita, Hirohito

    2014-08-15

    Humans are frequently exposed to various airborne allergens in the atmospheric environment. These allergens may trigger a complex network of immune responses in the airways, resulting in asthma and other chronic airway diseases. In this study, we investigated the immunological mechanisms involved in the pathological changes induced by chronic exposure to multiple airborne allergens. Naive mice were exposed intranasally to a combination of common airborne allergens, including the house dust mite, Alternaria, and Aspergillus, for up to 8 wk. These allergens acted synergistically and induced robust eosinophilic airway inflammation, specific IgE Ab production, type 2 cytokine response, and airway hyperresponsiveness in 4 wk, followed by airway remodeling in 8 wk. Increased lung infiltration of T cells, B cells, and type 2 innate lymphoid cells was observed. CD4(+) T cells and type 2 innate lymphoid cells contributed to the sources of IL-5 and IL-13, suggesting involvement of both innate and adaptive immunity in this model. The lung levels of IL-33 increased quickly within several hours after allergen exposure and continued to rise throughout the chronic phase of inflammation. Mice deficient in IL-33R (Il1rl1(-/-)) and thymic stromal lymphopoietin receptor (Tslpr(-/-)) showed significant reduction in airway inflammation, IgE Ab levels, and airway hyperresponsiveness. In contrast, mice deficient in IL-25R or IL-1R showed minimal differences as compared with wild-type animals. Thus, chronic exposure to natural airborne allergens triggers a network of innate and adaptive type 2 immune responses and airway pathology, and IL-33 and thymic stromal lymphopoietin most likely play key roles in this process. PMID:25015831

  10. Dielectric properties of native and decoated spores of Bacillus megaterium.

    PubMed Central

    Carstensen, E L; Marquis, R E; Child, S Z; Bender, G R

    1979-01-01

    A general model for use in interpreting dielectric data obtained with bacterial endospores is developed and applied to past results for Bacillus cereus spores and new results for Bacillus megaterium spores. The latter were also subjected to a decoating treatment to yield dormant cells with damaged outer membranes that could be germinated with lysozyme. For both spore types, core ions appeared to be completely immobilized, and decoating of B. megaterium spores did not affect this extreme state of electrostasis in the core. The cortex of B. megaterium appeared to contain a high level of mobile ions, in the cortex of B. cereus. The outer membrane-coat complex of B. megaterium acted dielectrically as an insulating layer around the cortex, so that native dormant spores showed a Maxwell-Wagner dispersion over the frequency range from about 1 to 20 MHz. The decoating treatment resulted in a shift in the dispersion to frequencies below the range of observation. Increases in cell conductivity in response to increases in environmental ionic strength indicated that the coats. of B. megaterium could be penetrated by environmental ions and that they had an inherent fixed charge concentration of about 10 to 20 milliequivalents per liter. In contrast, the dispersion for B. cereus spores was very sensitive to changes in environmental ion concentration, and it appeared that some 40% of the spore volume could be penetrated by environmental ions and that these ions traversed a dielectrically effective layer, either the exosporium or the outer membrane. It appears that dormancy is associated with extreme electrostasis of core ions but not necessarily of ions in enveloping structures and that the coat-outer membrane complex is dielectrically effective but not required for maintenance of extreme electrostasis in the core. PMID:118161

  11. Viable spore counts in biological controls pre-sterilization.

    PubMed

    Brusca, María I; Bernat, María I; Turcot, Liliana; Nastri, Natalia; Nastri, Maria; Rosa, Alcira

    2005-01-01

    The aim of the present study was to evaluate the total count of viable spores in standardized inoculated carriers pre-sterilization. Samples of "Bacterial Spore Sterilization Strip" (R Biological Laboratories) (well before their expiry date) were divided into Group A (B. subtilis) and Group B (B. stearothermophylus). Twenty-four strips were tested per group. The strips were minced in groups of three, placed in chilled sterile water and vortexed for 5 minutes to obtain a homogenous suspension. Ten ml of the homogenous suspension were transferred to two sterile jars, i.e. one jar per group. The samples were then heated in a water bath at 95 degrees C (Group A) or 80 degrees C (Group B) for 15 minutes and cooled rapidly in an ice bath at 0- 4 degrees C during 15 minutes. Successive dilutions were performed until a final aliquot of 30 to 300 colony-forming units (CFU) was obtained. The inoculums were placed in Petri dishes with culture medium (soy extract, casein agar adapted for spores, melted and cooled to 45-50 degrees C) and incubated at 55 degrees C or 37 degrees C. Statistical analysis of the data was performed. A larger number of spores were found at 48 hours than at 24 hours. However, this finding did not hold true for all the groups. The present results show that monitoring viable spores pre-sterilization would guarantee the accuracy of the data. Total spore counts must be within 50 and 300% of the number of spores indicated in the biological control. The procedure is essential to guarantee the efficacy of the biological control. PMID:16673791

  12. Thermal inactivation and injury of Bacillus stearothermophilus spores.

    PubMed Central

    Feeherry, F E; Munsey, D T; Rowley, D B

    1987-01-01

    Aqueous spore suspensions of Bacillus stearothermophilus ATCC 12980 were heated at different temperatures for various time intervals in a resistometer, spread plated on antibiotic assay medium supplemented with 0.1% soluble starch without (AAMS) or with (AAMS-S) 0.9% NaCl, and incubated at 55 degrees C unless otherwise indicated. Uninjured spores formed colonies on AAMS and AAMS-S; injured spores formed colonies only on AAMS. Values of D, the decimal reduction time (time required at a given temperature for destruction of 90% of the cells), when survivors were recovered on AAMS were 62.04, 18.00, 8.00, 3.33, and 1.05 min at 112.8, 115.6, 118.3, 121.1, and 123.9 degrees C, respectively. Recovery on AAMS-S resulted in reduced decimal reduction time. The computed z value (the temperature change which will alter the D value by a factor of 10) for spores recovered on AAMS was 8.3 degrees C; for spores recovered on AAMS-S, it was 7.6 degrees C. The rates of inactivation and injury were similar. Injury (judged by salt sensitivity) was a linear function of the heating temperature. At a heating temperature of less than or equal to 118.3 degrees C, spore injury was indicated by the curvilinear portion of the survival curve (judged by salt sensitivity), showing that injury occurred early in the thermal treatment as well as during logarithmic inactivation (reduced decimal reduction time). Heat-injured spores showed an increased sensitivity not only to 0.9% NaCl but also to other postprocessing environmental factors such as incubation temperatures, a pH of 6.6 for the medium, and anaerobiosis during incubation. PMID:3566270

  13. Nature of airborne particulates at tropic exposure sites. Final report, November 1982-September 1984

    SciTech Connect

    Chen, F.; Dement, W.A.

    1984-09-01

    Airborne particulates were collected at five exposure sites in Panama using cascade impactor air samplers. Scanning electron microscopy, energy dispersive x-ray analysis, and culture identification techniques were used to analyze the particulates. Analysis revealed that the particulates consist of silicates, chlorides, and sulfur-rich and phosphorus-rich particles. Atmospheric particle levels were higher in the dry season than in the rainy season, and the predominant fungal species varied at each exposure site. The open direct exposure of culture plates served as a simple, appropriate method for monitoring atmospheric fungal spores.

  14. Expression of Meiotic Drive Elements Spore Killer-2 and Spore Killer-3 in Asci of Neurospora Tetrasperma

    PubMed Central

    Raju, N. B.; Perkins, D. D.

    1991-01-01

    It was shown previously that when a chromosomal Spore killer factor is heterozygous in Neurospora species with eight-spored asci, the four sensitive ascospores in each ascus die and the four survivors are all killers. Sk-2(K) and Sk-3(K) are nonrecombining haplotypes that segregate with the centromere of linkage group III. No killing occurs when either one of these killers is homozygous, but each is sensitive to killing by the other in crosses of Sk-2(K) X Sk-3(K). In the present study, Sk-2(K) and Sk-3(K) were transferred by recurrent backcrosses from the eight-spored species Neurospora crassa into Neurospora tetrasperma, a pseudohomothallic species which normally makes asci with four large spores, each heterokaryotic for mating type and for any other centromere-linked genes that are heterozygous in the cross. The action of Sk-2(K) and Sk-3(K) in N. tetrasperma is that predicted from their behavior in eight-spored species. A sensitive nucleus is protected from killing if it is enclosed in the same ascospore with a killer nucleus. Crosses of Sk-2(K) X Sk-2(S), Sk-3(K) X Sk-3(S), and Sk-2(K) X Sk-3(K) all produce four-spored asci that are wild type in appearance, with the ascospores heterokaryotic and viable. The Eight-spore gene E, which shows variable penetrance, was used to obtain N. tetrasperma asci in which two to eight spores are small and homokaryotic. When killer and sensitive alleles are segregating in the presence of E, only those ascospores that contain a killer allele survive. Half of the small ascospores are killed. In crosses of Sk-2(K) X Sk-3(K) (with E heterozygous), effectively all small ascospores are killed. The ability of N. tetrasperma to carry killer elements in cryptic condition suggests a possible role for Spore killers in the origin of pseudohomothallism, with adoption of the four-spored mode restoring ascospore viability of crosses in which killing would otherwise occur. PMID:1834522

  15. Characterization of Clostridium perfringens Spores That Lack SpoVA Proteins and Dipicolinic Acid▿

    PubMed Central

    Paredes-Sabja, Daniel; Setlow, Barbara; Setlow, Peter; Sarker, Mahfuzur R.

    2008-01-01

    Spores of Clostridium perfringens possess high heat resistance, and when these spores germinate and return to active growth, they can cause gastrointestinal disease. Work with Bacillus subtilis has shown that the spore's dipicolinic acid (DPA) level can markedly influence both spore germination and resistance and that the proteins encoded by the spoVA operon are essential for DPA uptake by the developing spore during sporulation. We now find that proteins encoded by the spoVA operon are also essential for the uptake of Ca2+ and DPA into the developing spore during C. perfringens sporulation. Spores of a spoVA mutant had little, if any, Ca2+ and DPA, and their core water content was approximately twofold higher than that of wild-type spores. These DPA-less spores did not germinate spontaneously, as DPA-less B. subtilis spores do. Indeed, wild-type and spoVA C. perfringens spores germinated similarly with a mixture of l-asparagine and KCl (AK), KCl alone, or a 1:1 chelate of Ca2+ and DPA (Ca-DPA). However, the viability of C. perfringens spoVA spores was 20-fold lower than the viability of wild-type spores. Decoated wild-type and spoVA spores exhibited little, if any, germination with AK, KCl, or exogenous Ca-DPA, and their colony-forming efficiency was 103- to 104-fold lower than that of intact spores. However, lysozyme treatment rescued these decoated spores. Although the levels of DNA-protective α/β-type, small, acid-soluble spore proteins in spoVA spores were similar to those in wild-type spores, spoVA spores exhibited markedly lower resistance to moist heat, formaldehyde, HCl, hydrogen peroxide, nitrous acid, and UV radiation than wild-type spores did. In sum, these results suggest the following. (i) SpoVA proteins are essential for Ca-DPA uptake by developing spores during C. perfringens sporulation. (ii) SpoVA proteins and Ca-DPA release are not required for C. perfringens spore germination. (iii) A low spore core water content is essential for full

  16. Inactivation of chemical and heat-resistant spores of Bacillus and Geobacillus by nitrogen cold atmospheric plasma evokes distinct changes in morphology and integrity of spores.

    PubMed

    van Bokhorst-van de Veen, Hermien; Xie, Houyu; Esveld, Erik; Abee, Tjakko; Mastwijk, Hennie; Nierop Groot, Masja

    2015-02-01

    Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is still not fully understood. In this study, the biocidal effect by nitrogen CAP was determined for chemical (hypochlorite and hydrogen peroxide), physical (UV) and heat-resistant spores. The three different sporeformers used are Bacillus cereus a food-borne pathogen, and Bacillus atrophaeus and Geobacillus stearothermophilus that are used as biological indicators for validation of chemical sterilization and thermal processes, respectively. The different spores showed variation in their degree of inactivation by applied heat, hypochlorite, hydrogen peroxide, and UV treatments, whereas similar inactivation results were obtained with the different spores treated with nitrogen CAP. G. stearothermophilus spores displayed high resistance to heat, hypochlorite, hydrogen peroxide, while for UV treatment B. atrophaeus spores are most tolerant. Scanning electron microscopy analysis revealed distinct morphological changes for nitrogen CAP-treated B. cereus spores including etching effects and the appearance of rough spore surfaces, whereas morphology of spores treated with heat or disinfectants showed no such changes. Moreover, microscopy analysis revealed CAP-exposed B. cereus spores to turn phase grey conceivably because of water influx indicating damage of the spores, a phenomenon that was not observed for non-treated spores. In addition, data are supplied that exclude UV radiation as determinant of antimicrobial activity of nitrogen CAP. Overall, this study shows that nitrogen CAP treatment has a biocidal effect on selected Bacillus and Geobacillus spores associated with alterations in spore surface morphology and loss of spore integrity. PMID:25481059

  17. Studies of the Commitment Step in the Germination of Spores of Bacillus Species ▿

    PubMed Central

    Yi, Xuan; Setlow, Peter

    2010-01-01

    Spores of Bacillus species are said to be committed when they continue through nutrient germination even when germinants are removed or their binding to spores' nutrient germinant receptors (GRs) is both reversed and inhibited. Measurement of commitment and the subsequent release of dipicolinic acid (DPA) during nutrient germination of spores of Bacillus cereus and Bacillus subtilis showed that heat activation, increased nutrient germinant concentrations, and higher average levels of GRs/spore significantly decreased the times needed for commitment, as well as lag times between commitment and DPA release. These lag times were also decreased dramatically by the action of one of the spores' two redundant cortex lytic enzymes (CLEs), CwlJ, but not by the other CLE, SleB, and CwlJ action did not affect the timing of commitment. The timing of commitment and the lag time between commitment and DPA release were also dependent on the specific GR activated to cause spore germination. For spore populations, the lag times between commitment and DPA release were increased significantly in spores that germinated late compared to those that germinated early, and individual spores that germinated late may have had lower appropriate GR levels/spore than spores that germinated early. These findings together provide new insight into the commitment step in spore germination and suggest several factors that may contribute to the large heterogeneity among the timings of various events in the germination of individual spores in spore populations. PMID:20435722

  18. The Exosporium Layer of Bacterial Spores: a Connection to the Environment and the Infected Host.

    PubMed

    Stewart, George C

    2015-12-01

    Much of what we know regarding bacterial spore structure and function has been learned from studies of the genetically well-characterized bacterium Bacillus subtilis. Molecular aspects of spore structure, assembly, and function are well defined. However, certain bacteria produce spores with an outer spore layer, the exosporium, which is not present on B. subtilis spores. Our understanding of the composition and biological functions of the exosporium layer is much more limited than that of other aspects of the spore. Because the bacterial spore surface is important for the spore's interactions with the environment, as well as being the site of interaction of the spore with the host's innate immune system in the case of spore-forming bacterial pathogens, the exosporium is worthy of continued investigation. Recent exosporium studies have focused largely on members of the Bacillus cereus family, principally Bacillus anthracis and Bacillus cereus. Our understanding of the composition of the exosporium, the pathway of its assembly, and its role in spore biology is now coming into sharper focus. This review expands on a 2007 review of spore surface layers which provided an excellent conceptual framework of exosporium structure and function (A. O. Henriques and C. P. Moran, Jr., Annu Rev Microbiol 61:555-588, 2007, http://dx.doi.org/10.1146/annurev.micro.61.080706.093224). That review began a process of considering outer spore layers as an integrated, multilayered structure rather than simply regarding the outer spore components as independent parts. PMID:26512126

  19. Processor architecture for airborne SAR systems

    NASA Technical Reports Server (NTRS)

    Glass, C. M.

    1983-01-01

    Digital processors for spaceborne imaging radars and application of the technology developed for airborne SAR systems are considered. Transferring algorithms and implementation techniques from airborne to spaceborne SAR processors offers obvious advantages. The following topics are discussed: (1) a quantification of the differences in processing algorithms for airborne and spaceborne SARs; and (2) an overview of three processors for airborne SAR systems.

  20. Evaluation of meteorological airborne Doppler radar

    NASA Technical Reports Server (NTRS)

    Hildebrand, P. H.; Mueller, C. K.

    1984-01-01

    This paper will discuss the capabilities of airborne Doppler radar for atmospheric sciences research. The evaluation is based on airborne and ground based Doppler radar observations of convective storms. The capability of airborne Doppler radar to measure horizontal and vertical air motions is evaluated. Airborne Doppler radar is shown to be a viable tool for atmospheric sciences research.

  1. Fighting Ebola with novel spore decontamination technologies for the military

    SciTech Connect

    Doona, Christopher J.; Feeherry, Florence E.; Kustin, Kenneth; Olinger, Gene G.; Setlow, Peter; Malkin, Alexander J.; Leighton, Terrance

    2015-08-12

    Recently, global public health organizations such as Doctors without Borders (MSF), the World Health Organization (WHO), Public Health Canada, National Institutes of Health (NIH), and the U.S. government developed and deployed Field Decontamination Kits (FDKs), a novel, lightweight, compact, reusable decontamination technology to sterilize Ebola-contaminated medical devices at remote clinical sites lacking infra-structure in crisis-stricken regions of West Africa (medical waste materials are placed in bags and burned). The basis for effectuating sterilization with FDKs is chlorine dioxide (ClO2) produced from a patented invention developed by researchers at the US Army Natick Soldier RD&E Center (NSRDEC) and commercialized as a dry mixed-chemical for bacterial spore decontamination. In fact, the NSRDEC research scientists developed an ensemble of ClO2 technologies designed for different applications in decontaminating fresh produce; food contact and handling surfaces; personal protective equipment; textiles used in clothing, uniforms, tents, and shelters; graywater recycling; airplanes; surgical instruments; and hard surfaces in latrines, laundries, and deployable medical facilities. These examples demonstrate the far-reaching impact, adaptability, and versatility of these innovative technologies. Here, we present the unique attributes of NSRDEC’s novel decontamination technologies and a Case Study of the development of FDKs that were deployed in West Africa by international public health organizations to sterilize Ebola-contaminated medical equipment. FDKs use bacterial spores as indicators of sterility. We review the properties and structures of spores and the mechanisms of bacterial spore inactivation by ClO2. We also review mechanisms of bacterial spore inactivation by novel, emerging, and established non-thermal technologies for food preservation, such as high pressure processing, irradiation, cold plasma, and chemical

  2. Fighting Ebola with novel spore decontamination technologies for the military

    DOE PAGESBeta

    Doona, Christopher J.; Feeherry, Florence E.; Kustin, Kenneth; Olinger, Gene G.; Setlow, Peter; Malkin, Alexander J.; Leighton, Terrance

    2015-08-12

    Recently, global public health organizations such as Doctors without Borders (MSF), the World Health Organization (WHO), Public Health Canada, National Institutes of Health (NIH), and the U.S. government developed and deployed Field Decontamination Kits (FDKs), a novel, lightweight, compact, reusable decontamination technology to sterilize Ebola-contaminated medical devices at remote clinical sites lacking infra-structure in crisis-stricken regions of West Africa (medical waste materials are placed in bags and burned). The basis for effectuating sterilization with FDKs is chlorine dioxide (ClO2) produced from a patented invention developed by researchers at the US Army Natick Soldier RD&E Center (NSRDEC) and commercialized as amore » dry mixed-chemical for bacterial spore decontamination. In fact, the NSRDEC research scientists developed an ensemble of ClO2 technologies designed for different applications in decontaminating fresh produce; food contact and handling surfaces; personal protective equipment; textiles used in clothing, uniforms, tents, and shelters; graywater recycling; airplanes; surgical instruments; and hard surfaces in latrines, laundries, and deployable medical facilities. These examples demonstrate the far-reaching impact, adaptability, and versatility of these innovative technologies. Here, we present the unique attributes of NSRDEC’s novel decontamination technologies and a Case Study of the development of FDKs that were deployed in West Africa by international public health organizations to sterilize Ebola-contaminated medical equipment. FDKs use bacterial spores as indicators of sterility. We review the properties and structures of spores and the mechanisms of bacterial spore inactivation by ClO2. We also review mechanisms of bacterial spore inactivation by novel, emerging, and established non-thermal technologies for food preservation, such as high pressure processing, irradiation, cold plasma, and chemical sanitizers, using an array of

  3. Fighting Ebola with novel spore decontamination technologies for the military.

    PubMed

    Doona, Christopher J; Feeherry, Florence E; Kustin, Kenneth; Olinger, Gene G; Setlow, Peter; Malkin, Alexander J; Leighton, Terrance

    2015-01-01

    Recently, global public health organizations such as Doctors without Borders (MSF), the World Health Organization (WHO), Public Health Canada, National Institutes of Health (NIH), and the U.S. government developed and deployed Field Decontamination Kits (FDKs), a novel, lightweight, compact, reusable decontamination technology to sterilize Ebola-contaminated medical devices at remote clinical sites lacking infra-structure in crisis-stricken regions of West Africa (medical waste materials are placed in bags and burned). The basis for effectuating sterilization with FDKs is chlorine dioxide (ClO2) produced from a patented invention developed by researchers at the US Army Natick Soldier RD&E Center (NSRDEC) and commercialized as a dry mixed-chemical for bacterial spore decontamination. In fact, the NSRDEC research scientists developed an ensemble of ClO2 technologies designed for different applications in decontaminating fresh produce; food contact and handling surfaces; personal protective equipment; textiles used in clothing, uniforms, tents, and shelters; graywater recycling; airplanes; surgical instruments; and hard surfaces in latrines, laundries, and deployable medical facilities. These examples demonstrate the far-reaching impact, adaptability, and versatility of these innovative technologies. We present herein the unique attributes of NSRDEC's novel decontamination technologies and a Case Study of the development of FDKs that were deployed in West Africa by international public health organizations to sterilize Ebola-contaminated medical equipment. FDKs use bacterial spores as indicators of sterility. We review the properties and structures of spores and the mechanisms of bacterial spore inactivation by ClO2. We also review mechanisms of bacterial spore inactivation by novel, emerging, and established non-thermal technologies for food preservation, such as high pressure processing, irradiation, cold plasma, and chemical sanitizers, using an array of Bacillus

  4. Fighting Ebola with novel spore decontamination technologies for the military

    PubMed Central

    Doona, Christopher J.; Feeherry, Florence E.; Kustin, Kenneth; Olinger, Gene G.; Setlow, Peter; Malkin, Alexander J.; Leighton, Terrance

    2015-01-01

    Recently, global public health organizations such as Doctors without Borders (MSF), the World Health Organization (WHO), Public Health Canada, National Institutes of Health (NIH), and the U.S. government developed and deployed Field Decontamination Kits (FDKs), a novel, lightweight, compact, reusable decontamination technology to sterilize Ebola-contaminated medical devices at remote clinical sites lacking infra-structure in crisis-stricken regions of West Africa (medical waste materials are placed in bags and burned). The basis for effectuating sterilization with FDKs is chlorine dioxide (ClO2) produced from a patented invention developed by researchers at the US Army Natick Soldier RD&E Center (NSRDEC) and commercialized as a dry mixed-chemical for bacterial spore decontamination. In fact, the NSRDEC research scientists developed an ensemble of ClO2 technologies designed for different applications in decontaminating fresh produce; food contact and handling surfaces; personal protective equipment; textiles used in clothing, uniforms, tents, and shelters; graywater recycling; airplanes; surgical instruments; and hard surfaces in latrines, laundries, and deployable medical facilities. These examples demonstrate the far-reaching impact, adaptability, and versatility of these innovative technologies. We present herein the unique attributes of NSRDEC’s novel decontamination technologies and a Case Study of the development of FDKs that were deployed in West Africa by international public health organizations to sterilize Ebola-contaminated medical equipment. FDKs use bacterial spores as indicators of sterility. We review the properties and structures of spores and the mechanisms of bacterial spore inactivation by ClO2. We also review mechanisms of bacterial spore inactivation by novel, emerging, and established non-thermal technologies for food preservation, such as high pressure processing, irradiation, cold plasma, and chemical sanitizers, using an array of Bacillus

  5. Airborne agent concentration analysis

    DOEpatents

    Gelbard, Fred

    2004-02-03

    A method and system for inferring airborne contaminant concentrations in rooms without contaminant sensors, based on data collected by contaminant sensors in other rooms of a building, using known airflow interconnectivity data. The method solves a least squares problem that minimizes the difference between measured and predicted contaminant sensor concentrations with respect to an unknown contaminant release time. Solutions are constrained to providing non-negative initial contaminant concentrations in all rooms. The method can be used to identify a near-optimal distribution of sensors within the building, when then number of available sensors is less than the total number of rooms. This is achieved by having a system-sensor matrix that is non-singular, and by selecting that distribution which yields the lowest condition number of all the distributions considered. The method can predict one or more contaminant initial release points from the collected data.

  6. Airborne Wind Turbine

    SciTech Connect

    2010-09-01

    Broad Funding Opportunity Announcement Project: Makani Power is developing an Airborne Wind Turbine (AWT) that eliminates 90% of the mass of a conventional wind turbine and accesses a stronger, more consistent wind at altitudes of near 1,000 feet. At these altitudes, 85% of the country can offer viable wind resources compared to only 15% accessible with current technology. Additionally, the Makani Power wing can be economically deployed in deep offshore waters, opening up a resource which is 4 times greater than the entire U.S. electrical generation capacity. Makani Power has demonstrated the core technology, including autonomous launch, land, and power generation with an 8 meter wingspan, 20 kW prototype. At commercial scale, Makani Power aims to develop a 600 kW, 28 meter wingspan product capable of delivering energy at an unsubsidized cost competitive with coal, the current benchmark for low-cost power.

  7. Germination of Individual Bacillus subtilis Spores with Alterations in the GerD and SpoVA Proteins, Which Are Important in Spore Germination▿

    PubMed Central

    Wang, Guiwen; Yi, Xuan; Li, Yong-qing; Setlow, Peter

    2011-01-01

    Release of Ca2+ with dipicolinic acid (CaDPA) was monitored by Raman spectroscopy and differential interference contrast microscopy during germination of individual spores of Bacillus subtilis strains with alterations in GerD and SpoVA proteins. Notable conclusions about germination after the addition of nutrient were as follows. (i) Following l-alanine addition, wild-type and gerD spores and spores with elevated SpoVA protein levels (↑SpoVA spores) slowly released ∼10% of their CaDPA during a variable (6- to 55-min) period ending at Tlag, the time when faster CaDPA release began. (ii) Tlag times were lower for ↑SpoVA spores than for wild-type spores and were higher for gerD spores. (iii) The long Tlag times of gerD spores were partially due to slow commitment to germinate. (iv) The intervals between the commitment to germinate and CaDPA release were similar for wild-type and ↑SpoVA spores but longer for gerD spores. (v) The times for rapid CaDPA release, ΔTrelease = Trelease − Tlag (with Trelease being the time at which CaDPA release was complete), were similar for wild-type, gerD, and ↑SpoVA spores. (vi) Spores with either one of two point mutations in the spoVA operon (spoVA1 and spoVA2 spores) exhibited a more rapid rate of CaDPA release beginning immediately after l-alanine addition leading to ∼65% CaDPA release prior to Tlag. (vii) Tlag times for spoVA1 and spoVA2 spores were longer than for wild-type spores. (viii) The intervals between spoVA1 and spoVA2 spores' commitment and CaDPA release were similar to those for wild-type spores, but commitment occurred later. In contrast to germination after the addition of nutrient, Tlag and ΔTrelease times were relatively similar during dodecylamine germination of spores of the five strains. These findings suggest the following. (i) GerD plays no role in CaDPA release during spore germination. (ii) SpoVA proteins are involved in CaDPA release during germination with nutrients, and probably with

  8. Detection of Bacterial Spores with Lanthanide-Macrocycle Binary Complexes

    PubMed Central

    Cable, Morgan L.; Kirby, James P.; Levine, Dana J.; Manary, Micah J.; Gray, Harry B.; Ponce, Adrian

    2009-01-01

    The detection of bacterial spores via dipicolinate-triggered lanthanide luminescence has been improved in terms of detection limit, stability, and susceptibility to interferents by use of lanthanide-macrocycle binary complexes. Specifically, we compared the effectiveness of Sm, Eu, Tb and Dy complexes with the macrocycle 1,4,7,10-tetraazacyclododecane-1,7-diacetate (DO2A) to the corresponding lanthanide aquo ions. The Ln(DO2A)+ binary complexes bind dipicolinic acid (DPA), a major constituent of bacterial spores, with greater affinity and demonstrate significant improvement in bacterial spore detection. Of the four luminescent lanthanides studied, the terbium complex exhibits the greatest dipicolinate binding affinity (100-fold greater than Tb3+ alone, and 10-fold greater than other Ln(DO2A)+ complexes) and highest quantum yield. Moreover, the inclusion of DO2A extends the pH range over which Tb-DPA coordination is stable, reduces the interference of calcium ions nearly 5-fold, and mitigates phosphate interference 1000-fold compared to free terbium alone. In addition, detection of Bacillus atrophaeus bacterial spores was improved by the use of Tb(DO2A)+, yielding a 3-fold increase in the signal-to-noise ratio over Tb3+. Out of the eight cases investigated, the Tb(DO2A)+ binary complex is best for the detection of bacterial spores. PMID:19537757

  9. Natural dissemination of Bacillus anthracis spores in northern Canada.

    PubMed

    Dragon, D C; Bader, D E; Mitchell, J; Woollen, N

    2005-03-01

    Soil samples were collected from around fresh and year-old bison carcasses and areas not associated with known carcasses in Wood Buffalo National Park during an active anthrax outbreak in the summer of 2001. Sample selection with a grid provided the most complete coverage of a site. Soil samples were screened for viable Bacillus anthracis spores via selective culture, phenotypic analysis, and PCR. Bacillus anthracis spores were isolated from 28.4% of the samples. The highest concentrations of B. anthracis spores were found directly adjacent to fresh carcasses and invariably corresponded to locations where the soil had been saturated with body fluids escaping the carcass through either natural body orifices or holes torn by scavengers. The majority of positive samples were found within 2 m of both year-old and fresh carcasses and probably originated from scavengers churning up and spreading the body fluid-saturated soil as they fed. Trails of lesser contamination radiating from the carcasses probably resulted from spore dissemination through adhesion to scavengers and through larger scavengers dragging away disarticulated limbs. Comparison of samples from minimally scavenged and fully necropsied carcass sites revealed no statistically significant difference in the level of B. anthracis spore contamination. Therefore, the immediate area around a suspected anthrax carcass should be considered substantially contaminated regardless of the condition of the carcass. PMID:15746366

  10. Environmental Persistence of Bacillus anthracis and Bacillus subtilis Spores

    PubMed Central

    Wood, Joseph P.; Meyer, Kathryn M.; Kelly, Thomas J.; Choi, Young W.; Rogers, James V.; Riggs, Karen B.; Willenberg, Zachary J.

    2015-01-01

    There is a lack of data for how the viability of biological agents may degrade over time in different environments. In this study, experiments were conducted to determine the persistence of Bacillus anthracis and Bacillus subtilis spores on outdoor materials with and without exposure to simulated sunlight, using ultraviolet (UV)-A/B radiation. Spores were inoculated onto glass, wood, concrete, and topsoil and recovered after periods of 2, 14, 28, and 56 days. Recovery and inactivation kinetics for the two species were assessed for each surface material and UV exposure condition. Results suggest that with exposure to UV, decay of spore viability for both Bacillus species occurs in two phases, with an initial rapid decay, followed by a slower inactivation period. The exception was with topsoil, in which there was minimal loss of spore viability in soil over 56 days, with or without UV exposure. The greatest loss in viable spore recovery occurred on glass with UV exposure, with nearly a four log10 reduction after just two days. In most cases, B. subtilis had a slower rate of decay than B. anthracis, although less B. subtilis was recovered initially. PMID:26372011

  11. Scanning Surface Potential Microscopy of Spore Adhesion on Surfaces

    SciTech Connect

    Lee, Ida; Chung, Eunhyea; Kweon, Hyojin; Yiacoumi, Sotira; Tsouris, Costas

    2012-01-01

    The adhesion of spores of Bacillus anthracis - the cause of anthrax and a likely biological threat - to solid surfaces is an important consideration in cleanup after an accidental or deliberate release. However, because of safety concerns, directly studying B. anthracis spores with advanced instrumentation is problematic. As a first step, we are examining the electrostatic potential of Bacillus thuringiensis (Bt), which is a closely related species that is often used as a simulant to study B. anthracis. Scanning surface potential microscopy (SSPM), also known as Kelvin probe force microscopy (KPFM), was used to investigate the influence of relative humidity (RH) on the surface electrostatic potential of Bt that had adhered to silica, mica, or gold substrates. AFM/SSPM side-by-side images were obtained separately in air, at various values of RH, after an aqueous droplet with spores was applied on each surface and allowed to dry before measurements. In the SSPM images, a negative potential on the surface of the spores was observed compared with that of the substrates. The surface potential decreased as the humidity increased. Spores were unable to adhere to a surface with an extremely negative potential, such as mica.

  12. Environmental Persistence of Bacillus anthracis and Bacillus subtilis Spores.

    PubMed

    Wood, Joseph P; Meyer, Kathryn M; Kelly, Thomas J; Choi, Young W; Rogers, James V; Riggs, Karen B; Willenberg, Zachary J

    2015-01-01

    There is a lack of data for how the viability of biological agents may degrade over time in different environments. In this study, experiments were conducted to determine the persistence of Bacillus anthracis and Bacillus subtilis spores on outdoor materials with and without exposure to simulated sunlight, using ultraviolet (UV)-A/B radiation. Spores were inoculated onto glass, wood, concrete, and topsoil and recovered after periods of 2, 14, 28, and 56 days. Recovery and inactivation kinetics for the two species were assessed for each surface material and UV exposure condition. Results suggest that with exposure to UV, decay of spore viability for both Bacillus species occurs in two phases, with an initial rapid decay, followed by a slower inactivation period. The exception was with topsoil, in which there was minimal loss of spore viability in soil over 56 days, with or without UV exposure. The greatest loss in viable spore recovery occurred on glass with UV exposure, with nearly a four log10 reduction after just two days. In most cases, B. subtilis had a slower rate of decay than B. anthracis, although less B. subtilis was recovered initially. PMID:26372011

  13. Culturability and concentration of indoor and outdoor airborne fungi in six single-family homes

    PubMed Central

    Lee, Taekhee; Grinshpun, Sergey A.; Martuzevicius, Dainius; Adhikari, Atin; Crawford, Carlos M.; Reponen, Tiina

    2008-01-01

    In this study, the culturability of indoor and outdoor airborne fungi was determined through long-term sampling (24-h) using a Button Personal Inhalable Aerosol Sampler. The air samples were collected during three seasons in six Cincinnati area homes that were free from moisture damage or visible mold. Cultivation and total microscopic enumeration methods were employed for the sample analysis. The geometric means of indoor and outdoor culturable fungal concentrations were 88 and 102 colony-forming units (CFU) m-3, respectively, with a geometric mean of the I/O ratio equal to 0.66. Overall, 26 genera of culturable fungi were recovered from the indoor and outdoor samples. For total fungal spores, the indoor and outdoor geometric means were 211 and 605 spores m-3, respectively, with a geometric mean of I/O ratio equal to 0.32. The identification revealed 37 fungal genera from indoor and outdoor samples based on the total spore analysis. Indoor and outdoor concentrations of culturable and total fungal spores showed significant correlations (r = 0.655, p<0.0001 and r = 0.633, p<0.0001, respectively). The indoor and outdoor median viabilities of fungi were 55% and 25%, respectively, which indicates that indoor environment provides more favorable survival conditions for the aerosolized fungi. Among the seasons, the highest indoor and outdoor culturability of fungi was observed in the fall. Cladosporium had a highest median value of culturability (38% and 33% for indoor and outdoor, respectively) followed by Aspergillus/Penicillium (9% and 2%) among predominant genera of fungi. Increased culturability of fungi inside the homes may have important implications because of the potential increase in the release of allergens from viable spores and pathogenicity of viable fungi on immunocompromised individuals. PMID:18458748

  14. Culturability and concentration of indoor and outdoor airborne fungi in six single-family homes

    NASA Astrophysics Data System (ADS)

    Lee, Taekhee; Grinshpun, Sergey A.; Martuzevicius, Dainius; Adhikari, Atin; Crawford, Carlos M.; Reponen, Tiina

    In this study, the culturability of indoor and outdoor airborne fungi was determined through long-term sampling (24-h) using a Button Personal Inhalable Aerosol Sampler. The air samples were collected during three seasons in six Cincinnati area homes that were free from moisture damage or visible mold. Cultivation and total microscopic enumeration methods were employed for the sample analysis. The geometric means of indoor and outdoor culturable fungal concentrations were 88 and 102 colony-forming units (CFU) m -3, respectively, with a geometric mean of the I/ O ratio equal to 0.66. Overall, 26 genera of culturable fungi were recovered from the indoor and outdoor samples. For total fungal spores, the indoor and outdoor geometric means were 211 and 605 spores m -3, respectively, with a geometric mean of I/ O ratio equal to 0.32. The identification revealed 37 fungal genera from indoor and outdoor samples based on the total spore analysis. Indoor and outdoor concentrations of culturable and total fungal spores showed significant correlations ( r=0.655, p<0.0001 and r=0.633, p<0.0001, respectively). The indoor and outdoor median viabilities of fungi were 55% and 25%, respectively, which indicates that indoor environment provides more favorable survival conditions for the aerosolized fungi. Among the seasons, the highest indoor and outdoor culturability of fungi was observed in the fall. Cladosporium had a highest median value of culturability (38% and 33% for indoor and outdoor, respectively) followed by Aspergillus/Penicillium (9% and 2%) among predominant genera of fungi. Increased culturability of fungi inside the homes may have important implications because of the potential increase in the release of allergens from viable spores and pathogenicity of viable fungi on immunocompromised individuals.

  15. Airborne Cloud Computing Environment (ACCE)

    NASA Technical Reports Server (NTRS)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  16. Understanding of the importance of the spore coat structure and pigmentation in the Bacillus subtilis spore resistance to low-pressure plasma sterilization

    NASA Astrophysics Data System (ADS)

    Raguse, Marina; Fiebrandt, Marcel; Denis, Benjamin; Stapelmann, Katharina; Eichenberger, Patrick; Driks, Adam; Eaton, Peter; Awakowicz, Peter; Moeller, Ralf

    2016-07-01

    Low-pressure plasmas have been evaluated for their potential in biomedical and defense purposes. The sterilizing effect of plasma can be attributed to several active agents, including (V)UV radiation, charged particles, radical species, neutral and excited atoms and molecules, and the electric field. Spores of Bacillus subtilis were used as a bioindicator and a genetic model system to study the sporicidal effects of low-pressure plasma decontamination. Wild-type spores, spores lacking the major protective coat layers (inner, outer, and crust), pigmentation-deficient spores or spore impaired in encasement (a late step in coat assembly) were systematically tested for their resistance to low-pressure argon, hydrogen, and oxygen plasmas with and without admixtures. We demonstrate that low-pressure plasma discharges of argon and oxygen discharges cause significant physical damage to spore surface structures as visualized by atomic force microscopy. Spore resistance to low-pressure plasma was primarily dependent on the presence of the inner, and outer spore coat layers as well as spore encasement, with minor or less importance of the crust and spore pigmentation, whereas spore inactivation itself was strongly influenced by the gas composition and operational settings.

  17. Bats Increase the Number of Cultivable Airborne Fungi in the "Nietoperek" Bat Reserve in Western Poland.

    PubMed

    Kokurewicz, Tomasz; Ogórek, Rafał; Pusz, Wojciech; Matkowski, Krzysztof

    2016-07-01

    The "Nietoperek" bat reserve located in Western Poland is one of the largest bat hibernation sites in the European Union with nearly 38,000 bats from 12 species. Nietoperek is part of a built underground fortification system from WWII. The aims of the study were (1) to determine the fungal species composition and changes during hibernation season in relation to bat number and microclimatic conditions and (2) evaluate the potential threat of fungi for bat assemblages and humans visiting the complex. Airborne fungi were collected in the beginning, middle and end of hibernation period (9 November 2013 and 17 January and 15 March 2014) in 12 study sites, one outside and 11 inside the complex. Ambient temperature (T a) and relative humidity (RH) were measured by the use of data loggers, and species composition of bats was recorded from the study sites. The collision method (Air Ideal 3P) sampler was used to detect 34 species of airborne fungi including Pseudogymnoascus destructans (Pd). The density of airborne fungi isolated from the outdoor air samples varied from 102 to 242 CFU/1 m(3) of air and from 12 to 1198 CFU in the underground air samples. There was a positive relationship between number of bats and the concentration of fungi. The concentration of airborne fungi increased with the increase of bats number. Analysis of other possible ways of spore transport to the underground indicated that the number of bats was the primary factor determining the number of fungal spores in that hibernation site. Microclimatic conditions where Pd was found (median 8.7 °C, min-max 6.1-9.9 °C and 100 %, min-max 77.5-100.0 %) were preferred by hibernating Myotis myotis and Myotis daubentonii; therefore, these species are most probably especially prone to infection by this fungi species. The spores of fungi found in the underground can be pathogenic for humans and animals, especially for immunocompromised persons, even though their concentrations did not exceed limits and

  18. Cytology of Spore Formation in Clostridium perfringens1

    PubMed Central

    Hoeniger, Judith F. M.; Stuart, Philip F.; Holt, Stanley C.

    1968-01-01

    The sequential morphological events in spore formation by Clostridium perfringens type D were observed in Ellner's medium where 80 to 100% of the cells formed spores. Gross structural changes were studied with the light microscope under phase-contrast, and in fixed cells by the use of both nigrosin and Giemsa preparations. Fine structure was examined with the electron microscope in both thin sections and frozen-etched preparations. During the first 3 hr of incubation, the original rod-shaped cells became ellipsoid to ovoid in shape; by 5 to 6 hr, subterminal spores had developed within these enlarged cells. The fine structural sequence was in most respects identical to that in other Bacillaceae, although some stages were illustrated with particular clarity. A unique feature was the development of a convoluted, membranous exosporium which adhered to the outer surface of the two coats and had an unusual fine structure resembling a rectangular array of subunits. Images PMID:4302300

  19. Evolutionary stasis of sporopollenin biochemistry revealed by unaltered Pennsylvanian spores.

    PubMed

    Fraser, W T; Scott, A C; Forbes, A E S; Glasspool, I J; Plotnick, R E; Kenig, F; Lomax, B H

    2012-10-01

    The biopolymer sporopollenin present in the spore/pollen walls of all land plants is regarded as one of the most recalcitrant biomacromolecules (biopolymers), providing protection against a range of abiotic stresses. This long-term stability is demonstrated by the near-ubiquitous presence of pollen and spores in the fossil record with spores providing the first evidence for the colonization of the land. Here, we report for the first time chemical analyses of geologically unaltered sporopollenin from Pennsylvanian (c. 310 million yr before present (MyBP)) cave deposits. Our data show that Pennsylvanian Lycophyta megaspore sporopollenin has a strong chemical resemblance to extant relatives and indicates that a co-polymer model of sporopollenin formation is the most likely configuration. Broader comparison indicates that extant sporopollenin structure is similar across widely spaced phylogenetic groups and suggests land plant sporopollenin structure has remained stable since embryophytes invaded land. PMID:22913758

  20. Differentiating bacterial spores from hoax materials by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Farquharson, Stuart; Smith, Wayne W.

    2004-03-01

    The bioterrorism of October 2001 caused by the distribution of anthrax through the U.S. postal system was compounded by the significant delay associated with positive identification of the Bacillus anthracis spores and the unknown extent of their distribution along the eastern seaboard. In the ensuing two years, literally thousands of hoaxes, letters containing harmless powders, have been mailed creating additional anxiety. Thus, there is a need for instruments and/or methods that can not only identify anthrax-causing spores to save lives, but also identify hoax materials to eliminate costly shutdowns. Here we present Raman spectra of Bacillus cereus spores, an anthrax surrogate, as well as of 30 common substances that might be used as hoax materials. We also examine the choice of laser excitation, 785 nm or 1064 nm, and its impact on the ability to measure visible particles in 5 minutes or less, and to provide a complete answer to the question of suspicious material identity.

  1. Adenosine Monophosphate-Based Detection of Bacterial Spores

    NASA Technical Reports Server (NTRS)

    Kern, Roger G.; Chen, Fei; Venkateswaran, Kasthuri; Hattori, Nori; Suzuki, Shigeya

    2009-01-01

    A method of rapid detection of bacterial spores is based on the discovery that a heat shock consisting of exposure to a temperature of 100 C for 10 minutes causes the complete release of adenosine monophosphate (AMP) from the spores. This method could be an alternative to the method described in the immediately preceding article. Unlike that method and related prior methods, the present method does not involve germination and cultivation; this feature is an important advantage because in cases in which the spores are those of pathogens, delays involved in germination and cultivation could increase risks of infection. Also, in comparison with other prior methods that do not involve germination, the present method affords greater sensitivity. At present, the method is embodied in a laboratory procedure, though it would be desirable to implement the method by means of a miniaturized apparatus in order to make it convenient and economical enough to encourage widespread use.

  2. Plasma effects on bacterial spores in a wet environment

    NASA Astrophysics Data System (ADS)

    Kuo, Spencer P.; Tarasenko, Olga; Nourkbash, Said; Bakhtina, Assya; Levon, Kalle

    2006-03-01

    An arc-seed microwave plasma torch, which can run stably at low airflow rate (e.g., 0.393 l s-1) and produces an abundance of reactive atomic oxygen in its plasma effluent, is applied for studying the effects of atomic oxygen on bacterial spores in solution. Bacillus cereus was chosen as the biological agent. The experimental results show that the plasma effluent can penetrate into water to kill B. cereus spores. The kill time (i.e., 10-fold reduction time) is about 10 s at an exposure distance of 3 cm, 24 s at 4 cm, and 31 s at 5 cm. Morphological studies are performed via scanning electron and atomic force microscopes, which take two- and three-dimensional images of spores to record the changes in their morphological structures and shapes caused by the plasma effluent. The loss of appendages and exosporium in the structure as well as flattened cell shapes are observed.

  3. Proteomic analysis of spore wall proteins and identification of two spore wall proteins from Nosema bombycis (Microsporidia).

    PubMed

    Wu, Zhengli; Li, Yanhong; Pan, Guoqing; Tan, Xiaohui; Hu, Junhua; Zhou, Zeyang; Xiang, Zhonghuai

    2008-06-01

    Microsporidia are fungal-like unicellular eukaryotes which develop as obligate intracellular parasites. They differentiate into resistant spores that are protected by a thick spore wall composed of a glycoprotein-rich outer layer or exospore and a chitin-rich inner layer or endospore. In this study performed on the silkworm pathogen Nosema bombycis, we analyzed the spore wall proteins (SWPs) by proteomic-based approaches, MALDI-TOF MS and LC-MS/MS, and 14 hypothetical spore wall proteins (HSWPs) or peptides were obtained in total. Furthermore, we have examined the SWPs by SDS-PAGE and three main spore wall peptides were detected with molecular weights of 32.7 kDa (SWP32), 30.4 kDa (SWP30), and 25.3 kDa (SWP25), respectively. By N-terminal amino acid residue sequencing, and searching the genomic DNA shotgun database of N. bombycis, the complete ORFs of SWP30 and SWP32 were obtained, which encode for a 278- and a 316-amino acid peptide, respectively. Mouse polyclonal antibodies were raised against SWP30 and SWP32 recombinant proteins produced in Escherichia coli, and the results of indirect immunofluorescence assay (IFA) and immunoelectron microscopy (IEM) analyses indicated SWP30 to be an endosporal protein while SWP32 was shown to be an exosporal protein. Both SWP30 and SWP32 are included in the 14 HSWPs identified by MS, confirming the results of the proteomic-based approaches. PMID:18563739

  4. Alternaria sp. MG1, a resveratrol-producing fungus: isolation, identification, and optimal cultivation conditions for resveratrol production.

    PubMed

    Shi, Junling; Zeng, Qin; Liu, Yanlin; Pan, Zhongli

    2012-07-01

    Due to its potential in preventing or slowing the occurrence of many diseases, resveratrol (3,5,4'-trihydroxystilbene) has attracted great research interest. The objective of this study was to identify microorganisms from selected plants that produce resveratrol and to optimize the conditions for resveratrol production. Endophytes from Merlot wine grapes (Vitis vinifera L. cv. Merlot), wild Vitis (Vitis quinquangularis Rehd.), and Japanese knotweed (Polygonum cuspidatum Siebold & Zucc.) were isolated, and their abilities to produce resveratrol were evaluated. A total of 65 isolates were obtained and 21 produced resveratrol (6-123 μg/L) in liquid culture. The resveratrol-producing isolates belonged to seven genera, Botryosphaeria, Penicillium, Cephalosporium, Aspergillus, Geotrichum, Mucor, and Alternaria. The resveratrol-producing capability decreased or was completely lost in most isolates after three rounds of subculture. It was found that only the strain Alternaria sp. MG1 (isolated from cob of Merlot using GA1 medium) had stable and high resveratrol-producing capability in all subcultures. During liquid cultivation of Alternaria sp. MG1 in potato dextrose medium, the synthesis of resveratrol began on the first day, increased to peak levels on day 7, and then decreased sharply thereafter. Cell growth increased during cultivation and reached a stable and high level of biomass after 5 days. The best fermentation conditions for resveratrol production in liquid cultures of Alternaria sp. MG1 were an inoculum size of 6 %, a medium volume of 125 mL in a 250-mL flask, a rotation speed of 101 rpm, and a temperature of 27 °C. PMID:22526800

  5. Role of Dipicolinic Acid in the Germination, Stability, and Viability of Spores of Bacillus subtilis▿

    PubMed Central

    Magge, Anil; Granger, Amanda C.; Wahome, Paul G.; Setlow, Barbara; Vepachedu, Venkata R.; Loshon, Charles A.; Peng, Lixin; Chen, De; Li, Yong-qing; Setlow, Peter

    2008-01-01

    Spores of Bacillus subtilis spoVF strains that cannot synthesize dipicolinic acid (DPA) but take it up during sporulation were prepared in medium with various DPA concentrations, and the germination and viability of these spores as well as the DPA content in individual spores were measured. Levels of some other small molecules in DPA-less spores were also measured. These studies have allowed the following conclusions. (i) Spores with no DPA or low DPA levels that lack either the cortex-lytic enzyme (CLE) SleB or the receptors that respond to nutrient germinants could be isolated but were unstable and spontaneously initiated early steps in spore germination. (ii) Spores that lacked SleB and nutrient germinant receptors and also had low DPA levels were more stable. (iii) Spontaneous germination of spores with no DPA or low DPA levels was at least in part via activation of SleB. (iv) The other redundant CLE, CwlJ, was activated only by the release of high levels of DPA from spores. (v) Low levels of DPA were sufficient for the viability of spores that lacked most α/β-type small, acid-soluble spore proteins. (vi) DPA levels accumulated in spores prepared in low-DPA-containing media varied greatly between individual spores, in contrast to the presence of more homogeneous DPA levels in individual spores made in media with high DPA concentrations. (vii) At least the great majority of spores of several spoVF strains that contained no DPA also lacked other major spore small molecules and had gone through some of the early reactions in spore germination. PMID:18469099

  6. Spore Yield and Microcycle Conidiation of Colletotrichum gloeosporioides in Liquid Culture

    PubMed Central

    Cascino, J. J.; Harris, R. F.; Smith, C. S.; Andrews, J. H.

    1990-01-01

    The effect of V8 juice concentration (5 to 40%, vol/vol), spore inoculum density (105 and 107 spores per ml), and liquid batch or fed-batch culture condition on mycelium and spore production by Colletotrichum gloeosporioides was evaluated. The amount of mycelium produced, the time required for initiation of sporulation following attainment of maximum mycelium, and the time for attainment of maximum spore concentration increased with increasing V8 juice concentration in batch culture. Cultures containing V8 juice at >10% achieved a similar spore density (apparent spore-carrying capacity) of about 0.8 mg of spores per ml (1 × 107 to 2 × 107 spores per ml) independent of inoculum density and V8 juice concentration. The relative spore yield decreased from a high of 64% of the total biomass for the low-inoculum 5% V8 culture, through 13% for the analogous 40% V8 culture, to a low of 2% for the high-inoculum 27% V8 culture. Fed-batch cultures were used to establish conditions of high spore density and low substrate availability but high substrate flux. The rate of addition of V8 juice was adjusted to approximate the rate of substrate utilization by the (increasing) biomass. The final spore concentration was about four times higher (3.0 mg of spores per ml) than the apparent spore-carrying capacity in batch culture. This high spore yield was obtained at the expense of greatly reduced mycelium, resulting in a high relative spore yield (62% of the total biomass). Microcycle conidiation occurred in the fed-batch but not batch systems. These data indicate that substrate-limited, fed-batch culture can be used to increase the amount and efficiency of spore production by C. gloeosporioides by maintaining microcycle conidiation conditions favoring allocation of nutrients to spore rather than mycelium production. PMID:16348245

  7. [A study of the efficacy of disinfectants against anthrax spores].

    PubMed

    Lensing, H H; Oei, H L

    1984-07-01

    The activity of disinfectants with regard to spores of Bacillus anthracis was determined in a suspension test. Creoline (10%) and also several other disinfectants for veterinary use showed no activity against spores of B. anthracis. Natriumdichloorisocyanuraat-dihydrate (2400 ppm active chlorine) and peracetic acid 0,25% demonstrated after 30 minutes of exposures at 20 degrees C in the presence of 4% horse serum a significant sporicidal effect. Under the same conditions formaldehyde 4% and glutaraldehyde 2% were also found to be sporicidal but only after 2 hours of exposure. PMID:6431631

  8. Discrimination of Spore-Forming Bacilli Using spoIVA

    NASA Technical Reports Server (NTRS)

    Venkateswaran, Kasthuri; LaDuc, Myron; Stuecker, Tara

    2009-01-01

    A method of discriminating between spore-forming and non-spore-forming bacteria is based on a combination of simultaneous sporulation-specific and non-sporulation-specific quantitative polymerase chain reactions (Q-PCRs). The method was invented partly in response to the observation that for the purposes of preventing or reducing biological contamination affecting many human endeavors, ultimately, only the spore-forming portions of bacterial populations are the ones that are problematic (or, at least, more problematic than are the non-spore-forming portions). In some environments, spore-forming bacteria constitute small fractions of the total bacterial populations. The use of sporulation-specific primers in Q-PCR affords the ability to assess the spore-forming fraction of a bacterial population present in an environment of interest. This assessment can provide a more thorough and accurate understanding of the bacterial contamination in the environment, thereby making it possible to focus contamination- testing, contamination-prevention, sterilization, and decontamination resources more economically and efficiently. The method includes the use of sporulation-specific primers in the form of designed, optimized deoxyribonucleic acid (DNA) oligonucleotides specific for the bacterial spoIVA gene (see table). [In "spoIVA," "IV" signifies Roman numeral four and the entire quoted name refers to gene A for the fourth stage of sporulation.] These primers are mixed into a PCR cocktail with a given sample of bacterial cells. A control PCR cocktail into which are mixed universal 16S rRNA primers is also prepared. ["16S rRNA" denotes a ribosomal ribonucleic acid (rRNA) sequence that is common to all organisms.] Following several cycles of heating and cooling according to the PCR protocol to amplify amounts of DNA molecules, the amplification products can be analyzed to determine the types of bacterial cells present within the samples. If the amplification product is strong

  9. Effect of synthetic detergents on germination of fern spores

    SciTech Connect

    Devi, Y.; Devi, S.

    1986-12-01

    Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.

  10. Decontamination of Anthrax spores in critical infrastructure and critical assets.

    SciTech Connect

    Boucher, Raymond M.; Crown, Kevin K.; Tucker, Mark David; Hankins, Matthew Granholm

    2010-05-01

    Decontamination of anthrax spores in critical infrastructure (e.g., subway systems, major airports) and critical assets (e.g., the interior of aircraft) can be challenging because effective decontaminants can damage materials. Current decontamination methods require the use of highly toxic and/or highly corrosive chemical solutions because bacterial spores are very difficult to kill. Bacterial spores such as Bacillus anthracis, the infectious agent of anthrax, are one of the most resistant forms of life and are several orders of magnitude more difficult to kill than their associated vegetative cells. Remediation of facilities and other spaces (e.g., subways, airports, and the interior of aircraft) contaminated with anthrax spores currently requires highly toxic and corrosive chemicals such as chlorine dioxide gas, vapor- phase hydrogen peroxide, or high-strength bleach, typically requiring complex deployment methods. We have developed a non-toxic, non-corrosive decontamination method to kill highly resistant bacterial spores in critical infrastructure and critical assets. A chemical solution that triggers the germination process in bacterial spores and causes those spores to rapidly and completely change to much less-resistant vegetative cells that can be easily killed. Vegetative cells are then exposed to mild chemicals (e.g., low concentrations of hydrogen peroxide, quaternary ammonium compounds, alcohols, aldehydes, etc.) or natural elements (e.g., heat, humidity, ultraviolet light, etc.) for complete and rapid kill. Our process employs a novel germination solution consisting of low-cost, non-toxic and non-corrosive chemicals. We are testing both direct surface application and aerosol delivery of the solutions. A key Homeland Security need is to develop the capability to rapidly recover from an attack utilizing biological warfare agents. This project will provide the capability to rapidly and safely decontaminate critical facilities and assets to return them to

  11. Spore Photoproduct Lyase: The Known, the Controversial, and the Unknown*

    PubMed Central

    Yang, Linlin; Li, Lei

    2015-01-01

    Spore photoproduct lyase (SPL) repairs 5-thyminyl-5,6-dihydrothymine, a thymine dimer that is also called the spore photoproduct (SP), in germinating endospores. SPL is a radical S-adenosylmethionine (SAM) enzyme, utilizing the 5′-deoxyadenosyl radical generated by SAM reductive cleavage reaction to revert SP to two thymine residues. Here we review the current progress in SPL mechanistic studies. Protein radicals are known to be involved in SPL catalysis; however, how these radicals are quenched to close the catalytic cycle is under debate. PMID:25477522

  12. Atmospheric transport of mold spores in clouds of desert dust

    USGS Publications Warehouse

    Shinn, E.A.; Griffin, Dale W.; Seba, D.B.

    2003-01-01

    Fungal spores can be transported globally in clouds of desert dust. Many species of fungi (commonly known as molds) and bacteria--including some that are human pathogens--have characteristics suited to long-range atmospheric transport. Dust from the African desert can affect air quality in Africa, Europe, the Middle East, and the Americas. Asian desert dust can affect air quality in Asia, the Arctic, North America, and Europe. Atmospheric exposure to mold-carrying desert dust may affect human health directly through allergic induction of respiratory stress. In addition, mold spores within these dust clouds may seed downwind ecosystems in both outdoor and indoor environments.

  13. [The flotation characteristics of Bacillus cells and spores].

    PubMed

    Stabnikova, E V; Gregirchak, N N; Taranenko, T O

    1991-01-01

    Variations in hydrophobicity of the surface of bacillary cells and their capacity to flotation in the process of batch cultivation have been studied. It is shown that hydrophobicity of the cell surface increases in the course of batch cultivation of Bacillus thuringiensis, B. licheniformis and B. megaterium. Hydrophobicity of spores of the mentioned cultures is considerably higher than that of the vegetative cells. The increase of hydrophobicity of bacillary cells positively correlated with their capacity to flotation. That is why the use of flotation for the age fractionation of bacillary cells is possible: spores are concentrated in the foam while vegetative cells remain in the culture liquid. PMID:1779906

  14. Spore-displayed streptavidin: A live diagnostic tool in biotechnology

    SciTech Connect

    Kim, June-Hyung; Lee, Chang-Soo; Kim, Byung-Gee . E-mail: byungkim@snu.ac.kr

    2005-05-27

    Streptavidin, which is one of the most widely used proteins in biotechnological application field and is active only in tetrameric form, was surface expressed on the surface of Bacillus subtilis spore. Spore coat protein of B. subtilis, CotG, was used as an anchoring motif to display streptavidin. FACS using anti-streptavidin antibody was used for the verification of surface localization of expressed CotG-streptavidin fusion protein. FACS and dot-blot were used for the verification of biological activity of displayed streptavidin with FITC-labeled biotin.

  15. Proton dynamics in bacterial spores, a neutron scattering investigation

    NASA Astrophysics Data System (ADS)

    Colas de la Noue, Alexandre; Peters, Judith; Gervais, Patrick; Martinez, Nicolas; Perrier-Cornet, Jean-Marie; Natali, Francesca

    2015-01-01

    Results from first neutron scattering experiments on bacterial spores are reported. The elastic intensities and mean square displacements have a non-linear behaviour as function of temperature, which is in agreement with a model presenting more pronounced variations at around 330 K (57 ∘C) and 400 K (127 ∘C). Based on the available literature on thermal properties of bacterial spores, mainly referring to differential scanning calorimetry, they are suggested to be associated to main endothermic transitions induced by coat and/or core bacterial response to heat treatment.

  16. Impact of Alternaria toxins on CYP1A1 expression in different human tumor cells and relevance for genotoxicity.

    PubMed

    Pahlke, G; Tiessen, C; Domnanich, K; Kahle, N; Groh, I A M; Schreck, I; Weiss, C; Marko, D

    2016-01-01

    The Alternaria toxins alternariol (AOH) and alternariol monomethyl ether (AME) have been reported previously to act as activators of the aryl hydrocarbon receptor (AhR) in murine hepatoma cells, thus enhancing the expression of cytochrome P450 (CYP) 1A monooxygenases. Concomitantly, both benzopyrones represent substrates of CYP1A, giving rise to catecholic metabolites. The impact of AOH and AME on CYP1A expression in human cells of different tissue origin colon (HT29), esophagus (KYSE510), liver (HepG2) and their effects on cell viability, generation of reactive oxygen species (ROS) and DNA integrity were investigated. ROS production was induced by both mycotoxins in all cell lines with AOH exhibiting the highest potency in esophageal cells concomitant with the most prominent CYP1A induction level. Of note, altertoxin-II (ATX-II), the more potent DNA-damaging mutagen formed by Alternaria alternata, induces CYP1A even at significant lower concentrations. AhR-siRNA knockdown in human esophageal cells supported the hypothesis of AhR-mediated CYP1A1 induction by AOH. However, DNA damage was minor at CYP1A1-inducing AOH concentrations. AhR-depletion did not affect the DNA-damaging properties of AOH indicating no substantial impact of AhR in this regard. However, in combination with xenobiotics prone to metabolic activation by CYP1A the induction of CYP1A by Alternaria toxins deserves further attention. PMID:26474839

  17. FAST CARS: Engineering a laser spectroscopic technique for rapid identification of bacterial spores

    PubMed Central

    Scully, M. O.; Kattawar, G. W.; Lucht, R. P.; Opatrný, T.; Pilloff, H.; Rebane, A.; Sokolov, A. V.; Zubairy, M. S.

    2002-01-01

    Airborne contaminants, e.g., bacterial spores, are usually analyzed by time-consuming microscopic, chemical, and biological assays. Current research into real-time laser spectroscopic detectors of such contaminants is based on e.g., resonance fluorescence. The present approach derives from recent experiments in which atoms and molecules are prepared by one (or more) coherent laser(s) and probed by another set of lasers. However, generating and using maximally coherent oscillation in macromolecules having an enormous number of degrees of freedom is challenging. In particular, the short dephasing times and rapid internal conversion rates are major obstacles. However, adiabatic fast passage techniques and the ability to generate combs of phase-coherent femtosecond pulses provide tools for the generation and utilization of maximal quantum coherence in large molecules and biopolymers. We call this technique FAST CARS (femtosecond adaptive spectroscopic techniques for coherent anti-Stokes Raman spectroscopy), and the present article proposes and analyses ways in which it could be used to rapidly identify preselected molecules in real time. PMID:12177405

  18. Trypacidin, a Spore-Borne Toxin from Aspergillus fumigatus, Is Cytotoxic to Lung Cells

    PubMed Central

    Gauthier, Thierry; Wang, Xiaodi; Sifuentes Dos Santos, Joice; Fysikopoulos, Athanasios; Tadrist, Souria; Canlet, Cécile; Artigot, Marie Pierre; Loiseau, Nicolas; Oswald, Isabelle P.; Puel, Olivier

    2012-01-01

    Inhalation of Aspergillus fumigatus conidia can cause severe aspergillosis in immunosuppressed people. A. fumigatus produces a large number of secondary metabolites, some of which are airborne by conidia and whose toxicity to the respiratory tract has not been investigated. We found that spores of A. fumigatus contain five main compounds, tryptoquivaline F, fumiquinazoline C, questin, monomethylsulochrin and trypacidin. Fractionation of culture extracts using RP-HPLC and LC-MS showed that samples containing questin, monomethylsulochrin and trypacidin were toxic to the human A549 lung cell line. These compounds were purified and their structure verified using NMR in order to compare their toxicity against A549 cells. Trypacidin was the most toxic, decreasing cell viability and triggering cell lysis, both effects occurring at an IC50 close to 7 µM. Trypacidin toxicity was also observed in the same concentration range on human bronchial epithelial cells. In the first hour of exposure, trypacidin initiates the intracellular formation of nitric oxide (NO) and hydrogen peroxide (H2O2). This oxidative stress triggers necrotic cell death in the following 24 h. The apoptosis pathway, moreover, was not involved in the cell death process as trypacidin did not induce apoptotic bodies or a decrease in mitochondrial membrane potential. This is the first time that the toxicity of trypacidin to lung cells has been reported. PMID:22319557

  19. Exposure to airborne microorganisms, dust and endotoxin during processing of peppermint and chamomile herbs on farms.

    PubMed

    Skórska, Czesława; Sitkowska, Jolanta; Krysińska-Traczyk, Ewa; Cholewa, Grazyna; Dutkiewicz, Jacek

    2005-01-01

    The aim of this study was to determine the levels of microorganisms, dust and endotoxin in the air during processing of peppermint (Mentha piperita) and chamomile (Matricaria recutita) by herb farmers, and to examine the species composition of airborne microflora. Air samples were collected on glass fibre filters by use of personal samplers on 13 farms owned by herb cultivating farmers, located in Lublin province (eastern Poland). The concentrations of total viable microorganisms (bacteria + fungi) in the farm air during processing of peppermint herb were large, within a range from 895.1-6,015.8 x 10(3) cfu/m(3) (median 1,055.3 x 10(3) cfu/m(3)). During processing of chamomile herb they were much lower and varied within a range from 0.88-295.6 x 10(3) cfu/m(3) (median 27.3 x 10(3) cfu/m(3)). Gram-negative bacteria distinctly prevailed during processing of peppermint leaves, forming 46.4-88.5 % of the total airborne microflora. During processing of chamomile herb, Gram-negative bacteria were dominant at 3 out of 6 sampling sites forming 54.7-75.3 % of total microflora, whereas at the remaining 3 sites the most common were fungi forming 46.2-99.9 % of the total count. The species Pantoea agglomerans (synonyms: Erwinia herbicola, Enterobacter agglomerans ), having strong allergenic and endotoxic properties, distinctly prevailed among Gram-negative isolates. Among fungi, the most common species was Alternaria alternata. The concentrations of airborne dust and endotoxin determined on the examined herb farms were large. The concentrations of airborne dust during peppermint and chamomile processing ranged from 86.7-958.9 mg/m(3), and from 1.1-499.2 mg/m(3), respectively (medians 552.3 mg/m(3) and 12.3 mg/m(3)). The concentrations of airborne endotoxin determined during peppermint and chamomile processing were within a wide range 1.53-208.33 microg/m(3) and 0.005-2604.19 microg/m(3) respectively (medians 57.3 microg/m(3) and 0.96 microg/m(3)). In conclusion, farmers

  20. Exposure to airborne microorganisms, dust and endotoxin during flax scutching on farms.

    PubMed

    Krysińska-Traczyk, Ewa; Skórska, Czesława; Prazmo, Zofia; Sitkowska, Jolanta; Cholewa, Grazyna; Dutkiewicz, Jacek

    2004-01-01

    Microbiological air sampling was performed on 5 flax farms located in eastern Poland. Air samples for determination of the concentrations of microorganisms, dust and endotoxin were collected in barns during machine scutching of flax stems by the farmers. The concentrations of mesophilic bacteria ranged from 203.5-698.8 x 10(3) cfu/m3, of Gram-negative bacteria from 27.2-123.4 x 10(3) cfu/m3, of thermophilic actinomycetes from 0.5-2.6 x 10(3) cfu/m3, and of fungi from 23.4-99.8 x 10(3) cfu/m3. The concentrations of total airborne microorganisms (bacteria + fungi) were within a range of 245.0-741.0 x 10(3) cfu/m3. The values of the respirable fraction of total airborne microflora on the examined farms were between 45.5-98.3%. Corynebacteria (irregular Gram-positive rods, mostly Corynebacterium spp.) were dominant at all sampling sites, forming 46.8-67.8% of the total airborne microflora. Among Gram-negative bacteria, the most numerous species was Pantoea agglomerans (synonyms: Erwinia herbicola, Enterobacter agglomerans), known to have strong endotoxic and allergenic properties. Among fungi, the allergenic species Alternaria alternata prevailed. Altogether, 25 species or genera of bacteria and 10 species or genera of fungi were identified in the farm air during flax scutching; of these, 11 and 6 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of airborne dust ranged within 43.7-648.1 mg/m3 (median 93.6 mg/m3), exceeding on all farms the Polish OEL value of 4 mg/m3. The concentrations of airborne endotoxin ranged within 16.9-172.1 microg/m3 (median 30.0 microg/m3), exceeding at all sampling sites the suggested OEL value of 0.2 microg/m). In conclusion, flax farmers performing machine scutching of flax could be exposed to large concentrations of airborne microorganisms, dust and endotoxin, posing a risk of work-related respiratory disease. PMID:15627342

  1. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  2. An automated front-end monitor for anthrax surveillance systems based on the rapid detection of airborne endospores.

    PubMed

    Yung, Pun To; Lester, Elizabeth D; Bearman, Greg; Ponce, Adrian

    2007-11-01

    A fully automated anthrax smoke detector (ASD) has been developed and tested. The ASD is intended to serve as a cost effective front-end monitor for anthrax surveillance systems. The principle of operation is based on measuring airborne endospore concentrations, where a sharp concentration increase signals an anthrax attack. The ASD features an air sampler, a thermal lysis unit, a syringe pump, a time-gated spectrometer, and endospore detection chemistry comprised of dipicolinic acid (DPA)-triggered terbium ion (Tb(3+)) luminescence. Anthrax attacks were simulated using aerosolized Bacillus atrophaeus spores in fumed silica, and corresponding Tb-DPA intensities were monitored as a function of time and correlated to the number of airborne endospores collected. A concentration dependence of 10(2)-10(6) spores/mg of fumed silica yielded a dynamic range of 4 orders of magnitude and a limit of detection of 16 spores/L when 250 L of air were sampled. Simulated attacks were detected in less than 15 min. PMID:17514759

  3. Verruculogen production in airborne and clinical isolates of Aspergillus fumigatus Fres.

    PubMed

    Kosalec, Ivan; Klarić, Maja Segvić; Pepeljnjak, Stjepan

    2005-12-01

    Among airborne aspergilli sampled in outdoor air of the Zagreb area (2002/2003), Aspergillus niger (v. Teigh.) and A. fumigatus (Fres.) were the most abundant species (20-30%), with low mean annual concentrations (0.21-1.04 CFU m-3). Higher concentrations of A. fumigatus were observed in autumn and winter (0.5-1.05 CFU m-3) than in spring and summer (0-0.4 CFU m-3). On the other hand, A. fumigatus was found to be the most frequent isolate from upper and/or lower respiratory tracts of imunocompromised patients in many studies. This species produces several mycotoxins, including the tremorgenic mycotoxin verruculogen that can be found in spores and during myceliar growth. Verruculogen production ability was tested on 30 airborne and 33 clinical isolates of A. fumigatus. In both groups, high percentage of verruculogen-producing strains was noticed (84% of airborne and 91% of clinical isolates). Verruculogen production was not significantly different in the groups of airborne isolates (0.34+/-0.16 mg mL-1), and clinical isolates (0.26+/-0.19 mg mL-1). PMID:16375825

  4. Natural Occurrence of Alternaria Toxins in Wheat-Based Products and Their Dietary Exposure in China

    PubMed Central

    Zhao, Kai; Shao, Bing; Yang, Dajin; Li, Fengqin; Zhu, Jianghui

    2015-01-01

    A total of 181 wheat flour and 142 wheat-based foods including dried noodle, steamed bread and bread collected in China were analyzed for alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and tenuazonic acid (TeA) by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. TeA was the predominant toxin found in 99.4% wheat flour samples at levels ranging from 1.76 μg/kg to 520 μg/kg. TEN was another Alternaria toxin frequently detected in wheat flour samples (97.2%) at levels between 2.72 μg/kg and 129 μg/kg. AOH and AME were detected in 11 (6.1%) samples at levels ranging from 16.0 μg/kg to 98.7 μg/kg (AOH) and in 165 (91.2%) samples with a range between 0.320 μg/kg and 61.8 μg/kg (AME). AOH was quantified at higher levels than AME with the ratio of AOH/AME ranging from 1.0 to 3.7. Significant linear regressions of correlation in toxin concentrations were observed between AOH and AME, AME and TeA, TEN and TeA, AOH+AME and TeA. At an average and 95th percentile, dietary exposure to AOH and AME in the Chinese general population and different age subgroups exceeded the relevant threshold value of toxicological concern (TTC), with the highest exposure found in children which deserves human health concern. TEN and TeA seem unlikely to be health concerns for the Chinese via wheat-based products but attention should be paid to synergistic or additive effects of TeA with AOH, AME, TEN and a further assessment will be performed once more data on toxicity-guided fractionation of the four toxins are available. It is necessary to conduct a systemic surveillance of Alternaria toxins in raw and processed foods in order to provide the scientific basis for making regulations on these toxins in China. PMID:26121047

  5. Natural Occurrence of Alternaria Toxins in Wheat-Based Products and Their Dietary Exposure in China.

    PubMed

    Zhao, Kai; Shao, Bing; Yang, Dajin; Li, Fengqin; Zhu, Jianghui

    2015-01-01

    A total of 181 wheat flour and 142 wheat-based foods including dried noodle, steamed bread and bread collected in China were analyzed for alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and tenuazonic acid (TeA) by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. TeA was the predominant toxin found in 99.4% wheat flour samples at levels ranging from 1.76 μg/kg to 520 μg/kg. TEN was another Alternaria toxin frequently detected in wheat flour samples (97.2%) at levels between 2.72 μg/kg and 129 μg/kg. AOH and AME were detected in 11 (6.1%) samples at levels ranging from 16.0 μg/kg to 98.7 μg/kg (AOH) and in 165 (91.2%) samples with a range between 0.320 μg/kg and 61.8 μg/kg (AME). AOH was quantified at higher levels than AME with the ratio of AOH/AME ranging from 1.0 to 3.7. Significant linear regressions of correlation in toxin concentrations were observed between AOH and AME, AME and TeA, TEN and TeA, AOH+AME and TeA. At an average and 95th percentile, dietary exposure to AOH and AME in the Chinese general population and different age subgroups exceeded the relevant threshold value of toxicological concern (TTC), with the highest exposure found in children which deserves human health concern. TEN and TeA seem unlikely to be health concerns for the Chinese via wheat-based products but attention should be paid to synergistic or additive effects of TeA with AOH, AME, TEN and a further assessment will be performed once more data on toxicity-guided fractionation of the four toxins are available. It is necessary to conduct a systemic surveillance of Alternaria toxins in raw and processed foods in order to provide the scientific basis for making regulations on these toxins in China. PMID:26121047

  6. FORMALDEHYDE GAS INACTIVATION OF BACILLUS ANTHRACIS, BACILLUS SUBTILIS AND GEOBACILLUS STEAROTHERMOPHILUS SPORES ON INDOOR SURFACE MATERIALS.

    EPA Science Inventory

    Research evaluated the decontamination of Bacillus anthracis, Bacillus subtilis, and Geobacillus stearothermophilus spores on indoor surface material using formaldehyde gas. Spores were dried on seven types of indoor surfaces and exposed to 1100 ppm formaldehyde gas for 10 hr. Fo...

  7. Airborne GLM Simulator (FEGS)

    NASA Astrophysics Data System (ADS)

    Quick, M.; Blakeslee, R. J.; Christian, H. J., Jr.; Stewart, M. F.; Podgorny, S.; Corredor, D.

    2015-12-01

    Real time lightning observations have proven to be useful for advanced warning and now-casting of severe weather events. In anticipation of the launch of the Geostationary Lightning Mapper (GLM) onboard GOES-R that will provide continuous real time observations of total (both cloud and ground) lightning, the Fly's Eye GLM Simulator (FEGS) is in production. FEGS is an airborne instrument designed to provide cal/val measurements for GLM from high altitude aircraft. It consists of a 5 x 5 array of telescopes each with a narrow passband filter to isolate the 777.4 nm neutral oxygen emission triplet radiated by lightning. The telescopes will measure the optical radiance emitted by lightning that is transmitted through the cloud top with a temporal resolution of 10 μs. When integrated on the NASA ER-2 aircraft, the FEGS array with its 90° field-of-view will observe a cloud top area nearly equal to a single GLM pixel. This design will allow FEGS to determine the temporal and spatial variation of light that contributes to a GLM event detection. In addition to the primary telescope array, the instrument includes 5 supplementary optical channels that observe alternate spectral emission features and will enable the use of FEGS for interesting lightning physics applications. Here we present an up-to-date summary of the project and a description of its scientific applications.

  8. Airborne rescue system

    NASA Technical Reports Server (NTRS)

    Haslim, Leonard A. (Inventor)

    1991-01-01

    The airborne rescue system includes a boom with telescoping members for extending a line and collar to a rescue victim. The boom extends beyond the tip of the helicopter rotor so that the victim may avoid the rotor downwash. The rescue line is played out and reeled in by winch. The line is temporarily retained under the boom. When the boom is extended, the rescue line passes through clips. When the victim dons the collar and the tension in the line reaches a predetermined level, the clips open and release the line from the boom. Then the rescue line can form a straight line between the victim and the winch, and the victim can be lifted to the helicopter. A translator is utilized to push out or pull in the telescoping members. The translator comprises a tape and a rope. Inside the telescoping members the tape is curled around the rope and the tape has a tube-like configuration. The tape and rope are provided from supply spools.

  9. Comparative dose-survival curves of representative Clostridium botulinum type F spores with type A and B spores.

    PubMed Central

    Anellis, A; Berkowitz, D

    1977-01-01

    Radiation survival data of proteolytic (Walls 8G-F) and non-proteolytic (Eklund 83F) type F spores of Clostridium botulinum were compared with dose-response data of radiation-resistant type A (33A) and B (40B) spores. Strain Eklund 83F was as resistant as strain 33A, whereas strain Walls 8G-F was the most sensitive of the four strains tested. The methods suggested for computing both an initial shoulder and a D value for the dose-survival curves yielded results comparable to the graphic techniques used to obtain these two parameters. PMID:337901

  10. Comparative dose-survival curves of representative Clostridium botulinum type F spores with type A and B spores.

    PubMed

    Anellis, A; Berkowitz, D

    1977-11-01

    Radiation survival data of proteolytic (Walls 8G-F) and non-proteolytic (Eklund 83F) type F spores of Clostridium botulinum were compared with dose-response data of radiation-resistant type A (33A) and B (40B) spores. Strain Eklund 83F was as resistant as strain 33A, whereas strain Walls 8G-F was the most sensitive of the four strains tested. The methods suggested for computing both an initial shoulder and a D value for the dose-survival curves yielded results comparable to the graphic techniques used to obtain these two parameters. PMID:337901

  11. Water and Small-Molecule Permeation of Dormant Bacillus subtilis Spores

    PubMed Central

    Cermak, Nathan; Feijó Delgado, Francisco; Setlow, Barbara; Setlow, Peter

    2015-01-01

    ABSTRACT We use a suspended microchannel resonator to characterize the water and small-molecule permeability of Bacillus subtilis spores based on spores' buoyant mass in different solutions. Consistent with previous results, we found that the spore coat is not a significant barrier to small molecules, and the extent to which small molecules may enter the spore is size dependent. We have developed a method to directly observe the exchange kinetics of intraspore water with deuterium oxide, and we applied this method to wild-type spores and a panel of congenic mutants with deficiencies in the assembly or structure of the coat. Compared to wild-type spores, which exchange in approximately 1 s, several coat mutant spores were found to have relatively high water permeability with exchange times below the ∼200-ms temporal resolution of our assay. In addition, we found that the water permeability of the spore correlates with the ability of spores to germinate with dodecylamine and with the ability of TbCl3 to inhibit germination with l-valine. These results suggest that the structure of the coat may be necessary for maintaining low water permeability. IMPORTANCE Spores of Bacillus species cause food spoilage and disease and are extremely resistant to standard decontamination methods. This hardiness is partly due to spores' extremely low permeability to chemicals, including water. We present a method to directly monitor the uptake of molecules into B. subtilis spores by weighing spores in fluid. The results demonstrate the exchange of core water with subsecond resolution and show a correlation between water permeability and the rate at which small molecules can initiate or inhibit germination in coat-damaged spores. The ability to directly measure the uptake of molecules in the context of spores with known structural or genetic deficiencies is expected to provide insight into the determinants of spores' extreme resistance. PMID:26483518

  12. Tuber melosporum smooth spores: an anomalous feature in the genus Tuber.

    PubMed

    Lancellotti, Enrico; Fantini, Paolo; Iotti, Mirco; Franceschini, Antonio; Zambonelli, Alessandra

    2016-01-01

    This paper adds new insights on ecology and micromorphology of Tuber melosporum, a rare species with smooth spores. Eight T. melosporum ascomata collected in a 50 y old Pinus halepensis and Quercus ilex plantation in Sardinia, Italy, represent the first recovery of this species outside Spain. In comparison to the T. melosporum holotype, Italian specimens revealed differences in the number of spores in asci and spore shape. We propose an emended description of Tuber to include species without spore ornamentation. PMID:26490704

  13. Gene activity during germination of spores of the fern, Onoclea sensibilis. Cell-free translation analysis of mRNA of spores and the effect of alpha-amanitin on spore germination

    NASA Technical Reports Server (NTRS)

    Raghavan, V.

    1992-01-01

    Poly(A)-RNA fractions of dormant, dark-imbibed (non-germinating) and photoinduced (germinating) spores of Onoclea sensibilis were poor templates in the rabbit reticulocyte lysate protein synthesizing system, but the translational efficiency of poly(A)+RNA was considerably higher than that of unfractionated RNA. Poly(A)+RNA isolated from photoinduced spores had a consistently higher translational efficiency than poly(A)+RNA from dark-imbibed spores. Analysis of the translation products by one-dimensional polyacrylamide gel electrophoresis showed no qualitative differences in the mRNA populations of dormant, dark-imbibed, and photoinduced spores. However, poly(A)+RNA from dark-imbibed spores appeared to encode in vitro fewer detectable polypeptides at a reduced intensity than photoinduced spores. A DNA clone encoding the large subunit of maize ribulose bisphosphate carboxylase hybridized at strong to moderate intensity to RNA isolated from dark-imbibed spores, indicating the absence of mRNA degradation. Although alpha-amanitin did not inhibit the germination of spores, the drug prevented the elongation of the rhizoid and protonemal initial with a concomitant effect on the synthesis of poly(A)+RNA. These results are consistent with the view that some form of translational control involving stored mRNA operates during dark-imbibition and photoinduced germination of spores.

  14. Taphonomic bias in pollen and spore record: a review

    SciTech Connect

    Fisk, L.H.

    1986-05-01

    The high dispersibility and ease of pollen and spore transport have led researchers to conclude erroneously that fossil pollen and spore floras are relatively complete and record unbiased representations of the regional vegetation extant at the time of sediment deposition. That such conclusions are unjustified is obvious when the authors remember that polynomorphs are merely organic sedimentary particles and undergo hydraulic sorting not unlike clastic sedimentary particles. Prior to deposition in the fossil record, pollen and spores can be hydraulically sorted by size, shape, and weight, subtly biasing relative frequencies in fossil assemblages. Sorting during transport results in palynofloras whose composition is environmentally dependent. Therefore, depositional environment is an important consideration to make correct inferences on the source vegetation. Sediment particle size of original rock samples may contain important information on the probability of a taphonomically biased pollen and spore assemblage. In addition, a reasonable test of hydraulic sorting is the distribution of pollen grain sizes and shapes in each assemblage. Any assemblage containing a wide spectrum of grain sizes and shapes has obviously not undergone significant sorting. If unrecognized, taphonomic bias can lead to paleoecologic, paleoclimatic, and even biostratigraphic misinterpretations.

  15. Isolation of the Paenibacillus phoenicis, a Spore-Forming Bacterium

    NASA Technical Reports Server (NTRS)

    Benardini, James N.; Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Osman, Shariff; Satomi, Masataka

    2010-01-01

    A microorganism was isolated from the surfaces of the cleanroom facility in which the Phoenix lander was assembled. The isolated bacterial strain was subjected to a comprehensive polyphasic analysis to characterize its taxonomic position. Both phenotypic and phylogenetic analyses clearly indicate that this isolate belongs to the genus Paenibacillus and represents a novel species. Bacillus spores have been utilized to assess the degree and level of microbiological contamination on spacecraft and their associated spacecraft assembly facilities. Spores of Bacillus species are of particular concern to planetary protection due to the extreme resistance of some members of the genus to space environmental conditions such as UV and gamma radiation, vacuum, oxidation, and temperature fluctuation. These resistive spore phenotypes have enhanced potential for transfer, and subsequent proliferation, of terrestrial microbes on another solar body. Due to decreased nutrient conditions within spacecraft assembly facility clean rooms, the vegetative cells of Bacillus species and other spore-forming Paenibacillus species are induced to sporulate, thereby enhancing their survivability of bioreduction

  16. Two ways fungal spores can affect cotton color

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For a long time, we have observed that cotton can undergo color change when moisture conditions of the cotton sample would not be expected to support bacterial activity which normally requires free water. Several fungi can grow under low moisture pressures. It has been speculated that the spores p...

  17. 9 CFR 113.66 - Anthrax Spore Vaccine-Nonencapsulated.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... in 9 CFR 113.64 and the requirements in this paragraph. Any serial or subserial found unsatisfactory... serial or first subserial shall be tested for safety in sheep or goats by the methods described in 9 CFR... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Anthrax Spore...

  18. 9 CFR 113.66 - Anthrax Spore Vaccine-Nonencapsulated.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... in 9 CFR 113.64 and the requirements in this paragraph. Any serial or subserial found unsatisfactory... serial or first subserial shall be tested for safety in sheep or goats by the methods described in 9 CFR... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Anthrax Spore...

  19. 9 CFR 113.66 - Anthrax Spore Vaccine-Nonencapsulated.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... in 9 CFR 113.64 and the requirements in this paragraph. Any serial or subserial found unsatisfactory... serial or first subserial shall be tested for safety in sheep or goats by the methods described in 9 CFR... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Anthrax Spore...

  20. 9 CFR 113.66 - Anthrax Spore Vaccine-Nonencapsulated.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... in 9 CFR 113.64 and the requirements in this paragraph. Any serial or subserial found unsatisfactory... serial or first subserial shall be tested for safety in sheep or goats by the methods described in 9 CFR... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Anthrax Spore...