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Sample records for foliar bacterial diseases

  1. Role of stomata in plant innate immunity and foliar bacterial diseases.

    PubMed

    Melotto, Maeli; Underwood, William; He, Sheng Yang

    2008-01-01

    Pathogen entry into host tissue is a critical first step in causing infection. For foliar bacterial plant pathogens, natural surface openings, such as stomata, are important entry sites. Historically, these surface openings have been considered as passive portals of entry for plant pathogenic bacteria. However, recent studies have shown that stomata can play an active role in limiting bacterial invasion as part of the plant innate immune system. As a counter-defense, the plant pathogen Pseudomonas syringae pv. tomato DC3000 uses the virulence factor coronatine to actively open stomata. In nature, many foliar bacterial disease outbreaks require high humidity, rain, or storms, which could favor stomatal opening and/or bypass stomatal defense by creating wounds as alternative entry sites. Further studies on microbial and environmental regulation of stomatal closure and opening could fill gaps in our understanding of bacterial pathogenesis, disease epidemiology, and microbiology of the phyllosphere. PMID:18422426

  2. Foliar diseases of corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf blights and spots caused by fungi are some of the most destructive diseases of corn in the US and around the world. Correct identification of the disease is very important in determining the best means of control. For example, gray leaf spot of maize can be caused by one of at least two species...

  3. Bacteria in a wood fungal disease: characterization of bacterial communities in wood tissues of esca-foliar symptomatic and asymptomatic grapevines

    PubMed Central

    Bruez, Emilie; Haidar, Rana; Alou, Maryam T.; Vallance, Jessica; Bertsch, Christophe; Mazet, Flore; Fermaud, Marc; Deschamps, Alain; Guerin-Dubrana, Lucia; Compant, Stéphane; Rey, Patrice

    2015-01-01

    Esca is a grapevine trunk disease (GTD) associated with different pathogenic fungi inhabiting the woody tissues. Bacteria can also be found in such tissues and they may interact with these fungal colonizers. Although such types of microbial interactions have been observed for wood diseases in many trees, this has never been studied for grapevine. In this study, the bacterial microflora of different vine status (esca-symptomatic and asymptomatic), different anatomical part (trunk and cordon) and different type of tissues (necrotic or not) have been studied. Based on Single Strand Conformation Polymorphism (SSCP) analyses, data showed that (i) specific complexes of bacterial microflora colonize the wood of both necrotic and non-necrotic tissues of esca-foliar symptomatic and asymptomatic vines, and also that (ii) depending on the anatomical part of the plant, cordon or trunk, differences could be observed between the bacterial communities. Such differences were also revealed through the community-level physiological profiling (CLPP) with Biolog EcoplatesTM. Two hundred seventeen bacterial strains were also isolated from plant samples and then assigned to bacterial species based on the 16S rRNA genes. Although Bacillus sp. and Pantoea agglomerans were the two most commonly isolated species from all kinds of tissues, various other taxa were also isolated. Inoculation of vine cuttings with 14 different bacterial species, and one GTD fungus, Neofusicoccum parvum, showed no impact of these bacteria on the size of the wood necroses caused by N. parvum. This study showed, therefore, that bacterial communities differ according to the anatomical part (trunk or cordon) and/or the type of tissue (necrotic or non-necrotic) of wood of grapevine plants showing external symptoms of esca disease. However, research into bacteria having a role in GTD development needs further studies. PMID:26579076

  4. Bacteria in a wood fungal disease: characterization of bacterial communities in wood tissues of esca-foliar symptomatic and asymptomatic grapevines.

    PubMed

    Bruez, Emilie; Haidar, Rana; Alou, Maryam T; Vallance, Jessica; Bertsch, Christophe; Mazet, Flore; Fermaud, Marc; Deschamps, Alain; Guerin-Dubrana, Lucia; Compant, Stéphane; Rey, Patrice

    2015-01-01

    Esca is a grapevine trunk disease (GTD) associated with different pathogenic fungi inhabiting the woody tissues. Bacteria can also be found in such tissues and they may interact with these fungal colonizers. Although such types of microbial interactions have been observed for wood diseases in many trees, this has never been studied for grapevine. In this study, the bacterial microflora of different vine status (esca-symptomatic and asymptomatic), different anatomical part (trunk and cordon) and different type of tissues (necrotic or not) have been studied. Based on Single Strand Conformation Polymorphism (SSCP) analyses, data showed that (i) specific complexes of bacterial microflora colonize the wood of both necrotic and non-necrotic tissues of esca-foliar symptomatic and asymptomatic vines, and also that (ii) depending on the anatomical part of the plant, cordon or trunk, differences could be observed between the bacterial communities. Such differences were also revealed through the community-level physiological profiling (CLPP) with Biolog Ecoplates(TM). Two hundred seventeen bacterial strains were also isolated from plant samples and then assigned to bacterial species based on the 16S rRNA genes. Although Bacillus sp. and Pantoea agglomerans were the two most commonly isolated species from all kinds of tissues, various other taxa were also isolated. Inoculation of vine cuttings with 14 different bacterial species, and one GTD fungus, Neofusicoccum parvum, showed no impact of these bacteria on the size of the wood necroses caused by N. parvum. This study showed, therefore, that bacterial communities differ according to the anatomical part (trunk or cordon) and/or the type of tissue (necrotic or non-necrotic) of wood of grapevine plants showing external symptoms of esca disease. However, research into bacteria having a role in GTD development needs further studies. PMID:26579076

  5. The secret life of foliar bacterial pathogens on leaves.

    PubMed

    Beattie, G A; Lindow, S E

    1995-01-01

    This review focuses on the role of two distinct fitness strategies in the growth, survival, and epidemiology of foliar bacterial pathogens. A tolerance strategy requires the ability to tolerate direct exposure to environmental stresses on leaf surfaces, including UV radiation and low water availability. An avoidance strategy requires the ability to seek and/or exploit sites that are protected from these stresses, including endophytic sites. The ability to employ an avoidance strategy and grow endophytically may directly influence the potential for pathogenesis, since endophytic populations, not epiphytic populations, are likely responsible for disease induction. Furthermore, exchange between these two populations is probably crucial to the epidemiology of foliar pathogens. While foliar pathogens can grow and survive in both exposed and internal sites, indicating that they can employ both fitness strategies, the poor internal growth of most saprophytes suggests that saprophytes depend primarily on a strategy of tolerance. This difference between pathogens and saprophytes has important implications for predicting the population dynamics of leaf-associated bacterial species and for selecting effective biological control agents. PMID:18294082

  6. Foliar bacterial communities of trembling aspen in a common garden.

    PubMed

    Mason, Charles J; Pfammatter, Jesse A; Holeski, Liza M; Raffa, Kenneth F

    2015-02-01

    Microbial associations with plants are widely distributed and are structured by a number of biotic and physical factors. Among biotic factors, the host plant genotype may be integral to these plant-microbe interactions. Trees in the genus Populus have become models for studies in scaling effects of host plant genetics and in plant-microbe interactions. Using 454 pyrosequencing of the 16S rRNA gene, we assessed the foliar bacterial community of 7 genotypes of mature trembling aspen trees (Populus tremuloides Michx.) grown in a common garden. Trees were selected based on prior analyses showing clonal variation in their concentration of chemicals conferring resistance against insect herbivores. At broad taxonomic designations, the bacterial community of trembling aspen was similar across all plant genotypes. At a finer taxonomic scale, the foliage of these trees varied in their community composition, but there was no distinct pattern to colonization or abundance related to plant genotype. The most abundant operational taxonomic units (OTUs) were classified as Ralstonia, Bradyrhizobium, Pseudomonas, and Brucella. These OTUs varied across the common garden, but there was no significant effect of host plant genotype or spatial position on the abundance of these members. Our results suggest that aspen genotype is less important in the structuring of its foliar bacterial communities than are other, poorly understood processes. PMID:25602743

  7. Effect of glyphosate on foliar diseases in Roundup Ready alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar diseases are a serious problem for alfalfa management in all areas where alfalfa is grown. Defoliation due to foliar diseases varies from 3-71% depending on time of year, environmental conditions, and locale. Fungicide treatments are cost-effective in only some years and locations. Recently, ...

  8. Fungal and Bacterial Diseases.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungal and bacterial diseases are important constraints to production. Recognition of diseases and information on their biology is important in disease management. This chapter is aimed at providing diagnostic information on fungal and bacterial diseases of sugar beet and their biology, epidemiolo...

  9. Resistance to Foliar Diseases in Rosa sp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fifty cultivars of roses were evaluated for disease resistance to black spot and Cercospora leaf spot. Many rose cultivars were susceptibe to black spot, Cercospora leaf spot, or both. Six cultivars that were highly resistant to Cercospora leaf spot were susceptible to black spot (Belinda's Dream, M...

  10. Foliar disease control demonstrations for watermelon: Distant presentation of field trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar diseases are a serious concern of watermelon producers. In Oklahoma, for instance, several distinct foliar fungal diseases can result in complete crop loss when conditions are conducive to disease development. Proper fungicide use can reduce or prevent losses to these diseases. An educatio...

  11. Water relations in the interaction of foliar bacterial pathogens with plants.

    PubMed

    Beattie, Gwyn A

    2011-01-01

    This review examines the many ways in which water influences the relations between foliar bacterial pathogens and plants. As a limited resource in aerial plant tissues, water is subject to manipulation by both plants and pathogens. A model is emerging that suggests that plants actively promote localized desiccation at the infection site and thus restrict pathogen growth as one component of defense. Similarly, many foliar pathogens manipulate water relations as one component of pathogenesis. Nonvascular pathogens do this using effectors and other molecules to alter hormonal responses and enhance intercellular watersoaking, whereas vascular pathogens use many mechanisms to cause wilt. Because of water limitations on phyllosphere surfaces, bacterial colonists, including pathogens, benefit from the protective effects of cellular aggregation, synthesis of hygroscopic polymers, and uptake and production of osmoprotective compounds. Moreover, these bacteria employ tactics for scavenging and distributing water to overcome water-driven barriers to nutrient acquisition, movement, and signal exchange on plant surfaces. PMID:21438680

  12. Common foliar fungi of Populus trichocarpa modify Melampsora rust disease severity.

    PubMed

    Busby, Posy E; Peay, Kabir G; Newcombe, George

    2016-03-01

    Nonpathogenic foliar fungi (i.e. endophytes and epiphytes) can modify plant disease severity in controlled experiments. However, experiments have not been combined with ecological studies in wild plant pathosystems to determine whether disease-modifying fungi are common enough to be ecologically important. We used culture-based methods and DNA sequencing to characterize the abundance and distribution of foliar fungi of Populus trichocarpa in wild populations across its native range (Pacific Northwest, USA). We conducted complementary, manipulative experiments to test how foliar fungi commonly isolated from those populations influence the severity of Melampsora leaf rust disease. Finally, we examined correlative relationships between the abundance of disease-modifying foliar fungi and disease severity in wild trees. A taxonomically and geographically diverse group of common foliar fungi significantly modified disease severity in experiments, either increasing or decreasing disease severity. Spatial patterns in the abundance of some of these foliar fungi were significantly correlated (in predicted directions) with disease severity in wild trees. Our study reveals that disease modification is an ecological function shared by common foliar fungal symbionts of P. trichocarpa. This finding raises new questions about plant disease ecology and plant biodiversity, and has applied potential for disease management. PMID:26565565

  13. Fluid fragmentation shapes rain-induced foliar disease transmission.

    PubMed

    Gilet, T; Bourouiba, L

    2015-03-01

    onset dynamics of foliar epidemics through the lens of fluid fragmentation. We discuss how the reported findings can inform the design of mitigation strategies acting at the early stage of a foliar disease outbreak. PMID:25652459

  14. Fluid fragmentation shapes rain-induced foliar disease transmission

    PubMed Central

    Gilet, T.; Bourouiba, L.

    2015-01-01

    onset dynamics of foliar epidemics through the lens of fluid fragmentation. We discuss how the reported findings can inform the design of mitigation strategies acting at the early stage of a foliar disease outbreak. PMID:25652459

  15. Foliar Diseases of Apiaceae Crops in Coastal California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The number of outbreaks of leaf spot, blight and streak diseases on celery, cilantro, fennel and parsley has been increasing throughout central coastal California and particularly in Monterey County since 2002. Two different bacterial pathogens (Pseudomonas syringae pv. apii, and P. syringae pv. cor...

  16. [Bacterial diseases of rape].

    PubMed

    Zakharova, O M; Mel'nychuk, M D; Dankevych, L A; Patyka, V P

    2012-01-01

    Bacterial destruction of the culture was described and its agents identified in the spring and winter rape crops. Typical symptoms are the following: browning of stem tissue and its mucilagization, chlorosis of leaves, yellowing and beginning of soft rot in the place of leaf stalks affixion to stems, loss of pigmentation (violet). Pathogenic properties of the collection strains and morphological, cultural, physiological, and biochemical properties of the agents of rape's bacterial diseases isolated by the authors have been investigated. It was found that all the isolates selected by the authors are highly or moderately aggressive towards different varieties of rape. According to the complex of phenotypic properties 44% of the total number of isolates selected by the authors are related to representatives of the genus Pseudomonas, 37% - to Xanthomonas and 19% - to Pectobacterium. PMID:23293826

  17. Subalpine conifers in different geographical locations host highly similar foliar bacterial endophyte communities.

    PubMed

    Carrell, Alyssa A; Carper, Dana L; Frank, A Carolin

    2016-08-01

    Pines in the subalpine environment at Niwot Ridge, CO, have been found to host communities of acetic acid bacteria (AAB) within their needles. The significance and ubiquity of this pattern is not known, but recent evidence of nitrogen (N)-fixing activity in Pinus flexilis (limber pine) foliage calls for a better understanding of the processes that regulate endophytic communities in forest tree canopies. Here, to test if AAB dominate the foliar bacterial microbiota in other subalpine locations, we compared the 16S rRNA community in needles from P. flexilis and P. contorta (lodgepole pine) growing in the Eastern Sierra Nevada, CA, and Niwot Ridge, CO. AAB made up the majority of the bacterial community in both species at both sites. Multiple distinct AAB taxa, resolved at the single nucleotide level, were shared across host species and sites, with dominant OTUs identical or highly similar to database sequences from cold environments, including high altitude air sampled in Colorado, and the endosphere of Arctic plants. Our results suggest strong selection for community composition, potentially amplified by the long lifespan of individual Pinus needles, along with low dispersal constraints on canopy bacteria. PMID:27267931

  18. Changes in distribution and frequency of fungi associated with a foliar disease complex of pyrethrum in Australia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Australia, pyrethrum is affected by a foliar disease complex which can substantially reduce green leaf area and deleteriously affect yield. Traditionally, the dominant disease in spring has been ray blight, caused by Stagonosporopsis tanaceti, with other foliar diseases more prevalent during aut...

  19. Understanding the Impact of Drought on Foliar and Xylem Invading Bacterial Pathogen Stress in Chickpea.

    PubMed

    Sinha, Ranjita; Gupta, Aarti; Senthil-Kumar, Muthappa

    2016-01-01

    In field conditions, plants are concurrently exposed to multiple stresses, where one stressor impacts the plant's response to another stressor, and the resultant net effect of these stresses differs from individual stress response. The present study investigated the effect of drought stress on interaction of chickpea with Pseudomonas syringae pv. phaseolicola (Psp; foliar pathogen) and Ralstonia solanacearum (Rs; xylem inhabiting wilt causing pathogen), respectively, and the net-effect of combined stress on chlorophyll content and cell death. Two type of stress treatments were used to study the influence of each stress factor during combined stress, viz., imposition of drought stress followed by pathogen challenge (DP), and pathogen inoculated plants imposed with drought in course of pathogen infection (PD). Drought stress was imposed at different levels with pathogen inoculum to understand the influence of different stress intensities on stress interaction and their net impact. Drought stressed chickpea plants challenged with Psp infection (DPsp) showed reduced in planta bacterial number compared to Psp infection alone. Similarly, Rs infection of chickpea plants showed reduced in planta bacterial number under severe drought stress. Combined drought and Psp (DPsp) infected plants showed decreased cell death compared to plants infected only with Psp but the extent of cell death was similar to drought stressed plants. Similarly, chlorophyll content in plants under combined stress was similar to the individual drought stressed plants; however, the chlorophyll content was more compared to pathogen only infected plants. Under combined drought and Rs infection (DRs), cell death was similar to individual drought stress but significantly less compared to only Rs infected plants. Altogether, the study proposes that both stress interaction and net effect of combined stress could be majorly influenced by first occurring stress, for example, drought stress in DP treatment. In

  20. Understanding the Impact of Drought on Foliar and Xylem Invading Bacterial Pathogen Stress in Chickpea

    PubMed Central

    Sinha, Ranjita; Gupta, Aarti; Senthil-Kumar, Muthappa

    2016-01-01

    In field conditions, plants are concurrently exposed to multiple stresses, where one stressor impacts the plant's response to another stressor, and the resultant net effect of these stresses differs from individual stress response. The present study investigated the effect of drought stress on interaction of chickpea with Pseudomonas syringae pv. phaseolicola (Psp; foliar pathogen) and Ralstonia solanacearum (Rs; xylem inhabiting wilt causing pathogen), respectively, and the net-effect of combined stress on chlorophyll content and cell death. Two type of stress treatments were used to study the influence of each stress factor during combined stress, viz., imposition of drought stress followed by pathogen challenge (DP), and pathogen inoculated plants imposed with drought in course of pathogen infection (PD). Drought stress was imposed at different levels with pathogen inoculum to understand the influence of different stress intensities on stress interaction and their net impact. Drought stressed chickpea plants challenged with Psp infection (DPsp) showed reduced in planta bacterial number compared to Psp infection alone. Similarly, Rs infection of chickpea plants showed reduced in planta bacterial number under severe drought stress. Combined drought and Psp (DPsp) infected plants showed decreased cell death compared to plants infected only with Psp but the extent of cell death was similar to drought stressed plants. Similarly, chlorophyll content in plants under combined stress was similar to the individual drought stressed plants; however, the chlorophyll content was more compared to pathogen only infected plants. Under combined drought and Rs infection (DRs), cell death was similar to individual drought stress but significantly less compared to only Rs infected plants. Altogether, the study proposes that both stress interaction and net effect of combined stress could be majorly influenced by first occurring stress, for example, drought stress in DP treatment. In

  1. Acyl-homoserine lactones produced by Pantoea sp. isolated from the "maize white spot" foliar disease.

    PubMed

    Pomini, Armando M; Paccola-Meirelles, Luzia D; Marsaioli, Anita J

    2007-02-21

    The "maize white spot" foliar disease is a problem of increasing importance to Brazilian maize crops. A bacterium isolated from water-soaked lesions from infected maize leaves was pathogenic in biological assays in vivo. It was identified as a Gram-negative, nonsporulating, facultative anaerobic bacterium, belonging to the genus Pantoea. Chemical study of the extracts from bacterial cultivation media allowed the identification of (S)-(-)-N-butanoyl-homoserine lactone and trace amounts of N-hexanoyl-homoserine lactone, widely recognized quorum-sensing signaling substances employed in cell-to-cell communication systems. The absolute configuration of natural (S)-(-)-N-butanoyl-homoserine lactone was determined by gas chromatography-flame ionization detection with a chiral stationary phase and by comparison of circular dichroism spectroscopic data with enantiopure synthetic substances. Biological evaluations with reporter Agrobacterium tumefaciens NTL4(pZLR4) were carried out with synthetic and natural products and also with extracts from maize leaves contaminated with the isolated bacterium, as well as from healthy leaves. PMID:17256964

  2. Cold hardiness and foliar disease resistance of North American and Asian Fragaria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty-two wild strawberry genotypes and two commercial cultivars were obtained from the US Department of Agriculture (USDA), Agricultural Research Service (ARS), National Clonal Germplasm Repository-Corvallis (NCGR) and planted in the field to test cold hardiness and foliar disease resistance at th...

  3. Bacterial kidney disease (Renibacterium salmoninarum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a prevalent disease of salmonid fish that impacts sustainable production for consumption and species conservation efforts. The disease is chronic in nature and mortality most often occurs in juvenile salmonids and prespawning a...

  4. Probing occurrence of phenylpropanoids in Morinda citrifolia in relation to foliar diseases.

    PubMed

    Mandal, Sudhamoy; Rath, Chiranjibi; Gupta, Chandan Kumar; Nath, Vishal; Singh, Hari Shankar

    2015-01-01

    Accumulation of phenolic compounds in cell walls of different plant organs leading to increased lignification is an early defence response of plants against biotic stress. The aim of this work was to delineate occurrence of cell wall-bound (CWB) phenolic compounds in Morinda citrifolia leaves. Alkaline hydrolysis of the cell wall material of leaf tissues yielded 4-coumaric acid (4-CA) as the major bulk of the phenolic compounds in all Morinda germplasms. Next in line was 4-hydroxybenzoic acid. Other phenolics identified were vanillic acid, 4-hydroxybenzaldehyde, vanillin and ferulic acid. Concentrations of all the CWB phenolics were highest in the germplasm CHN-5, followed by the germplasm CHN-1. Incidentally, these two Morinda germplasms recorded lowest incidence of foliar diseases. Significantly higher amounts of 4-CA in combination with other phenolics may be the reasons for lowest incidence of foliar diseases in CHN-5 and CHN-1 germplasms of M. citrifolia. PMID:25184947

  5. Ex Vivo Application of Secreted Metabolites Produced by Soil-Inhabiting Bacillus spp. Efficiently Controls Foliar Diseases Caused by Alternaria spp.

    PubMed Central

    El-Sayed, Ashraf S. A.; Patel, Jaimin S.; Green, Kari B.; Ali, Mohammad; Brennan, Mary; Norman, David

    2015-01-01

    Bacterial biological control agents (BCAs) are largely used as live products to control plant pathogens. However, due to variable environmental and ecological factors, live BCAs usually fail to produce desirable results against foliar pathogens. In this study, we investigated the potential of cell-free culture filtrates of 12 different bacterial BCAs isolated from flower beds for controlling foliar diseases caused by Alternaria spp. In vitro studies showed that culture filtrates from two isolates belonging to Bacillus subtilis and Bacillus amyloliquefaciens displayed strong efficacy and potencies against Alternaria spp. The antimicrobial activity of the culture filtrate of these two biological control agents was effective over a wider range of pH (3.0 to 9.0) and was not affected by autoclaving or proteolysis. Comparative liquid chromatography-mass spectrometry (LC-MS) analyses showed that a complex mixture of cyclic lipopeptides, primarily of the fengycin A and fengycin B families, was significantly higher in these two BCAs than inactive Bacillus spp. Interaction studies with mixtures of culture filtrates of these two species revealed additive activity, suggesting that they produce similar products, which was confirmed by LC-tandem MS analyses. In in planta pre- and postinoculation trials, foliar application of culture filtrates of B. subtilis reduced lesion sizes and lesion frequencies caused by Alternaria alternata by 68 to 81%. Taken together, our studies suggest that instead of live bacteria, culture filtrates of B. subtilis and B. amyloliquefaciens can be applied either individually or in combination for controlling foliar diseases caused by Alternaria species. PMID:26519395

  6. A novel Botrytis species is associated with a newly emergent foliar disease in cultivated Hemerocallis.

    PubMed

    Grant-Downton, Robert T; Terhem, Razak B; Kapralov, Maxim V; Mehdi, Saher; Rodriguez-Enriquez, M Josefina; Gurr, Sarah J; van Kan, Jan A L; Dewey, Frances M

    2014-01-01

    Foliar tissue samples of cultivated daylilies (Hemerocallis hybrids) showing the symptoms of a newly emergent foliar disease known as 'spring sickness' were investigated for associated fungi. The cause(s) of this disease remain obscure. We isolated repeatedly a fungal species which proved to be member of the genus Botrytis, based on immunological tests. DNA sequence analysis of these isolates, using several different phyogenetically informative genes, indicated that they represent a new Botrytis species, most closely related to B. elliptica (lily blight, fire blight) which is a major pathogen of cultivated Lilium. The distinction of the isolates was confirmed by morphological analysis of asexual sporulating cultures. Pathogenicity tests on Hemerocallis tissues in vitro demonstrated that this new species was able to induce lesions and rapid tissue necrosis. Based on this data, we infer that this new species, described here as B. deweyae, is likely to be an important contributor to the development of 'spring sickness' symptoms. Pathogenesis may be promoted by developmental and environmental factors that favour assault by this necrotrophic pathogen. The emergence of this disease is suggested to have been triggered by breeding-related changes in cultivated hybrids, particularly the erosion of genetic diversity. Our investigation confirms that emergent plant diseases are important and deserve close monitoring, especially in intensively in-bred plants. PMID:24887415

  7. A Novel Botrytis Species Is Associated with a Newly Emergent Foliar Disease in Cultivated Hemerocallis

    PubMed Central

    Grant-Downton, Robert T.; Terhem, Razak B.; Kapralov, Maxim V.; Mehdi, Saher; Rodriguez-Enriquez, M. Josefina; Gurr, Sarah J.; van Kan, Jan A. L.; Dewey, Frances M.

    2014-01-01

    Foliar tissue samples of cultivated daylilies (Hemerocallis hybrids) showing the symptoms of a newly emergent foliar disease known as ‘spring sickness’ were investigated for associated fungi. The cause(s) of this disease remain obscure. We isolated repeatedly a fungal species which proved to be member of the genus Botrytis, based on immunological tests. DNA sequence analysis of these isolates, using several different phyogenetically informative genes, indicated that they represent a new Botrytis species, most closely related to B. elliptica (lily blight, fire blight) which is a major pathogen of cultivated Lilium. The distinction of the isolates was confirmed by morphological analysis of asexual sporulating cultures. Pathogenicity tests on Hemerocallis tissues in vitro demonstrated that this new species was able to induce lesions and rapid tissue necrosis. Based on this data, we infer that this new species, described here as B. deweyae, is likely to be an important contributor to the development of ‘spring sickness’ symptoms. Pathogenesis may be promoted by developmental and environmental factors that favour assault by this necrotrophic pathogen. The emergence of this disease is suggested to have been triggered by breeding-related changes in cultivated hybrids, particularly the erosion of genetic diversity. Our investigation confirms that emergent plant diseases are important and deserve close monitoring, especially in intensively in-bred plants. PMID:24887415

  8. Edge effects, not connectivity, determine the incidence and development of a foliar fungal plant disease.

    SciTech Connect

    Johnson, Brenda, L.; Haddad, Nick, M.

    2011-08-01

    Using a model plant-pathogen system in a large-scale habitat corridor experiment, we found that corridors do not facilitate the movement of wind-dispersed plant pathogens, that connectivity of patches does not enhance levels of foliar fungal plant disease, and that edge effects are the key drivers of plant disease dynamics. Increased spread of infectious disease is often cited as a potential negative effect of habitat corridors used in conservation, but the impacts of corridors on pathogen movement have never been tested empirically. Using sweet corn (Zea mays) and southern corn leaf blight (Cochliobolus heterostrophus) as a model plant-pathogen system, we tested the impacts of connectivity and habitat fragmentation on pathogen movement and disease development at the Savannah River Site, South Carolina, USA. Over time, less edgy patches had higher proportions of diseased plants, and distance of host plants to habitat edges was the greatest determinant of disease development. Variation in average daytime temperatures provided a possible mechanism for these disease patterns. Our results show that worries over the potentially harmful effects of conservation corridors on disease dynamics are misplaced, and that, in a conservation context, many diseases can be better managed by mitigating edge effects.

  9. Photochemical Transformation and Bacterial Utilization of Dissolved Organic Matter and Disinfection Byproduct Precursors from Foliar Litter

    NASA Astrophysics Data System (ADS)

    Chow, A. T.; Wong, P.; O'Geen, A. T.; Dahlgren, R. A.

    2009-12-01

    Foliar litter is an important terrestrial source of dissolved organic matter (DOM) in surface water. DOM is a public health concern since it is a precursor of carcinogenic disinfection byproducts (DBPs) during drinking water treatment. Chemical characterization of in-situ water samples for their impact on water treatment may be misleading because DOM characteristics can be altered from their original composition during downstream transport to water treatment plants. In this study, we collected leachate from four fresh litters and decomposed duffs from four dominant vegetation components of California oak woodlands: blue oak (Quercus douglassi), live oak (Quercus wislizenii), foothill pine (Pinus sabiniana), and annual grasses to evaluate their DOM degradability and the reactivity of altered DOM towards DBP formation. Samples were filtered through a sterilized membrane (0.2 micron) and exposed to natural sunlight and Escherichia coli K-12 independently for 14 days. Generally speaking, leachate from decomposed duff was relatively resistant towards biodegradation compared to that from fresh litter, but the former was more susceptible to photo-transformation. Photo-bleaching caused a 30% decrease in ultra-violet absorbance at 254 nm (UVA) but no significant changes in dissolved organic carbon (DOC) concentration. This apparent loss of aromatic carbon in DOM, in terms of specific UVA, did not result in a decrease of specific trihalomethane (THM) formation potential, although aromatic carbon is considered as a major reactive site for THM formation. In addition, there were significant increases (p < 0.05) of chloral hydrate after the 14-day exposure, suggesting that the photolytic products could be a precursor of chloral hydrate. In contrast, samples inoculated with E. coli did not show a significant effect on the DOC concentration, UVA or DBP formation, although the colony counts indicated a 2-log cell growth during the 14-day incubation. Results suggest photolysis is a

  10. Bacterial diseases of the skin.

    PubMed

    Edlich, Richard F; Winters, Kathryne L; Britt, L D; Long, William B

    2005-01-01

    When considering common bacterial diseases of the skin, rather distinct clinical responses to a variety of bacterial infections have been identified. In these cases, it is the specific site of infection and the attendant inflammatory responses that provide the characteristic clinical picture. When the pyoderma extends just below the stratum corneum, it is called impetigo. Nonbullous impetigo is the most common pediatric skin infection. It usually starts in a traumatized area. The typical lesion begins as an erythematous papule, after which it becomes a unilocular vesicle. When the subcorneal vesicle becomes pustular, it ruptures and eventually becomes a yellow, golden crust that is a hallmark of the disease process. Bullous impetigo is a less common form of impetigo, accounting for fewer than 30% of all impetigo cases. It occurs in infants and is characterized by rapid progression of vesicles to the formation of bullae measuring larger than 5 mm in diameter in previously untraumatized skin. Treatment of nonbullous impetigo must include intervention against the pathogen as well as improvements in the hygiene and living conditions of the patient. A fundamental tenet is to debride the crust (scab) from the wound surface using poloxamer 188. If the lesions are not widespread, topical mupirocin is the treatment of choice. Treatment of bullous impetigo is similar, except that the local cleansing and topical antibiotic must be complemented by systemic antibiotics if there is evidence of disseminating infections. Ecthyma is usually a consequence of failure to treat effectively impetigo. The untreated infection extends deep into the tissue in shallow ulcerations that often heal without scar. Treatment for ecthyma usually requires systemic antibiotics against either staphylococcus or streptococcus. Folliculitis is a pyoderma located within a hair follicle, secondary to follicular occlusion by keratin, overhydration, or either bacterial or fungal infection. Folliculitis may

  11. Vaccination against salmonid bacterial kidney disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial kidney disease (BKD) of salmonid fishes, caused by Renibacterium salmoninarum, has presented challenges for development of effective vaccines, despite several decades of research. The only vaccine against BKD that is commercially licensed is an injectable preparation containing live cells ...

  12. Effects of Biopesticides on Foliar Diseases and Japanese Beetle (Popillia japonica) Adults in Roses (Rosa spp.), Oakleaf Hydrangea (Hydrangea quercifolia), and Crapemyrtle (Lagerstroemia indica)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated efficacy of biopesticides for reducing foliar diseases and feeding damage from Japanese beetle adults on hybrid T rose (Rosa spp.), oakleaf hydrangea (Hydrangea quercifolia), and crapemyrtle (Lagerstroemia indica). The materials tested included household soaps with Triclosan act...

  13. Disease notes - Bacterial root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  14. Bacterial ureases in infectious diseases.

    PubMed

    Burne, R A; Chen, Y Y

    2000-04-01

    Ureases are multi-subunit, nickel-containing enzymes that catalyze the hydrolysis of urea to carbon dioxide and ammonia. This brief review discusses the biochemistry and genetics of bacterial ureases and outlines the roles of urea metabolism in microbial ecology and pathogenesis of some of the principle ureolytic species affecting human health. PMID:10865198

  15. Bacterial clinical infectious diseases ontology (BCIDO) dataset.

    PubMed

    Gordon, Claire L; Weng, Chunhua

    2016-09-01

    This article describes the Bacterial Infectious Diseases Ontology (BCIDO) dataset related to research published in http:dx.doi.org/ 10.1016/j.jbi.2015.07.014 [1], and contains the Protégé OWL files required to run BCIDO in the Protégé environment. BCIDO contains 1719 classes and 39 object properties. PMID:27508237

  16. Meningococcal Disease (Bacterial Meningitis) Vaccine and Pregnancy

    MedlinePlus

    Meningococcal Disease (Bacterial meningitis) Vaccine and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of having a baby ... advice from your health care provider. What is meningitis? Meningitis is an infection of the lining that ...

  17. Arthropod-borne bacterial diseases in pregnancy.

    PubMed

    Dotters-Katz, Sarah K; Kuller, Jeffrey; Heine, R Phillips

    2013-09-01

    Arthropod-borne bacterial diseases affect more than 25,000 Americans every year and thousands more around the world. These infections present a diagnostic dilemma for clinicians because they mimic many other pathologic conditions and are often low on or absent from the differential diagnosis list. Diagnosis is particularly challenging during pregnancy, as these infections may mimic common pregnancy-specific conditions, such as typical and atypical preeclampsia, or symptoms of pregnancy itself. Concerns regarding the safety in pregnancy of some indicated antibiotics add a therapeutic challenge for the prescriber, requiring knowledge of alternative therapeutic options for many arthropod-borne bacterial diseases. Physicians, especially those in endemic areas, must keep this class of infections in mind, particularly when the presentation does not appear classic for more commonly seen conditions. This article discusses presentation, diagnosis, and treatment of the most common of these arthropod-borne bacterial diseases, including Lyme disease, Rocky Mountain spotted fever, tick-borne relapsing fever, typhus, plague, cat-scratch disease, and Carrión disease. PMID:25102120

  18. Relationships between periodontal disease and bacterial pneumonia.

    PubMed

    Scannapieco, F A; Mylotte, J M

    1996-10-01

    Bacterial pneumonia is a prevalent and costly infection that is a significant cause of morbidity and mortality in patients of all ages. The continuing emergence of antibiotic-resistant bacteria (e.g., penicillin-resistant pneumococci) suggests that bacterial pneumonia will assume increasing importance in the coming years. Thus, knowledge of the pathogenesis of, and risk factors for, bacterial pneumonia is critical to the development of strategies for prevention and treatment of these infections. Bacterial pneumonia in adults is the result of aspiration of oropharyngeal flora into the lower respiratory tract and failure of host defense mechanisms to eliminate the contaminating bacteria, which multiply in the lung and cause infection. It is recognized that community-acquired pneumonia and lung abscesses can be the result of infection by anaerobic bacteria; dental plaque would seem to be a logical source of these bacteria, especially in patients with periodontal disease. It is also possible that patients with high risk for pneumonia, such as hospitalized patients and nursing home residents, are likely to pay less attention to personal hygiene than healthy patients. One important dimension of this personal neglect may be diminished attention to oral hygiene. Poor oral hygiene and periodontal disease may promote oropharyngeal colonization by potential respiratory pathogens (PRPs) including Enterobacteriaceae (Klebsiella pneumoniae, Escherichia coli, Enterobacter species, etc.), Pseudomonas aeruginosa, and Staphylococcus aureus. This paper provides the rationale for the development of this hypothesis especially as it pertains to mechanically ventilated intensive care unit patients and nursing home residents, two patient groups with a high risk for bacterial pneumonia. PMID:8910830

  19. Bacterial and parasitic diseases of parrots.

    PubMed

    Doneley, Robert J T

    2009-09-01

    As wild-caught birds become increasingly rare in aviculture, there is a corresponding decline in the incidence of bacterial and parasitic problems and an increase in the recognition of the importance of maintaining health through better nutrition and husbandry. Nevertheless, the relatively close confines of captivity mean an increased pathogen load in the environment in which companion and aviary parrots live. This increased pathogen load leads to greater exposure of these birds to bacteria and parasites, and consequently a greater risk of infection and disease. This article discusses bacterial and parasitic infections in companion and aviary parrots. It includes the origins, pathogens, diagnosis, treatment, and some of the associated risk factors. PMID:19732702

  20. Vaccination against bacterial kidney disease: Chapter 22

    USGS Publications Warehouse

    Elliott, Diane G.; Wiens, Gregory D.; Hammell, K. Larry; Rhodes, Linda D.

    2014-01-01

    Bacterial kidney disease (BKD) of salmonid fishes, caused by Renibacterium salmoninarum, has been recognized as a serious disease in salmonid fishes since the 1930s. This chapter discusses the occurrence and significance, etiology, and pathogenesis of BKD. It then describes the different vaccination procedures and the effects and side-effects of vaccination. Despite years of research, however, only a single vaccine has been licensed for prevention of BKD, and has demonstrated variable efficacy. Therefore, in addition to a presentation of the current status of BKD vaccination, a discussion of potential future directions for BKD vaccine development is included in the chapter. This discussion is focused on the unique characteristics of R. salmoninarum and its biology, as well as aspects of the salmonid immune system that might be explored specifically to develop more effective vaccines for BKD prevention.

  1. Chronic osteomyelitislike disease with negative bacterial cultures.

    PubMed

    Pelkonen, P; Ryöppy, S; Jääskeläinen, J; Rapola, J; Repo, H; Kaitila, I

    1988-11-01

    During a seven-year period we observed 14 children who had chronic osteomyelitislike disease. The bacterial cultures from the bone lesions were negative. In eight patients the findings were compatible with chronic recurrent multifocal osteomyelitis (CRMO), in four the findings were compatible with chronic sclerosing osteomyelitis of Garré, and two had osteomyelitis of the clavicle. In patients with CRMO, lymphocyte subpopulations, the responses to mitogens, and the chemotactic and chemokinetic responses showed no consistent abnormalities. After a mean follow-up of 4.5 years (range, one to ten years), all four patients with osteomyelitis of Garré were symptomatic, and two had complications. Only two of the eight patients with CRMO had active disease. The course had been complicated by growth disturbances in one patient and by thoracic outlet syndrome in another. Wegener's granulomatosis later developed in a patient with CRMO. PMID:3177323

  2. Current Concepts in Bacterial Sexually Transmitted Diseases

    PubMed Central

    2011-01-01

    Sexually transmitted diseases (STDs) are the most common infectious diseases worldwide, with over 350 million new cases occurring each year, and have far-reaching health, social, and economic consequences. Failure to diagnose and treat STDs at an early stage may result in serious complications and sequelae. STDs are passed from person to person primarily by sexual contact and are classified into varied groups. Some cause mild, acute symptoms and some are life-threatening. They are caused by many different infectious organisms and are treated in different ways. Syphilis and gonorrhea are ancient afflictions. Now, however, Chlamydia is prevalent and has become the most common bacterial STD. Antimicrobial resistance of several sexually transmitted pathogens is increasing, rendering some regimens ineffective, adding to therapeutic problems. A standardized treatment protocol for STDs is recommended to ensure that all patients receive adequate treatment. Appropriate treatment of STDs is an important public health measure. PMID:22025952

  3. A western type of bacterial gill disease

    USGS Publications Warehouse

    Fish, F.F.

    1935-01-01

    The first reference to a pathological condition of the gill tissues of salmonid fishes was made by Osburn in 1910. This author in describing a progressive infolding of the opercula of trout, commonly known to hatcherymen as "short gill covers," mentioned a marked proliferation on the gill epithelium as accompanying this condition. Osburn assumed that the club-like appearance of the gill filaments due to the proliferated epithelium was the result of continual irritation of the delicate gill tissue in the absence of the usual protection offered by the normal opercula. Although such a conclusion seems quite logical, it is also possible that Osburn was dealing with "short gill covers" complicated by the unknown bacterial gill disease which was subsequently described by Davis.

  4. Watermelon foliar fungicide timing trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar diseases are a persistent threat to watermelon production in Oklahoma. Several diseases that include anthracnose, downy mildew, and powdery mildew can result in yield and fruit quality losses when foliage is damaged. Effective fungicides are available for the control of these diseases. How...

  5. Bacterial flora in inflammatory bowel disease.

    PubMed

    Marteau, Philippe

    2009-01-01

    The pathogenesis of inflammatory bowel disease (IBD) involves an interaction between host susceptibility (which is partly genetically determined), mucosal immunity and the intestinal milieu. Micro-organisms have physiological effects on mucosal structure, epithelial turnover, the intestinal immune cells and, thus, on many intestinal functions. Toll-like receptors and nucleotide oligomerisation-binding domain proteins in host cells recognise specific bacterial molecules and modify the immune response. Human studies have repeatedly shown that the microbiota of patients with IBD differs from that of controls and is unstable, both in the intestinal lumen and at the surface of the mucosa. A single pathogen has not been identified, but potentially pro-inflammatory micro-organisms have been found in samples from IBD patients more often than from healthy controls. These include Mycobacterium paratuberculosis, and enteroadherent and invasive Escherichia coli in Crohn's disease (CD). Ecological descriptions of the microbiota present in patients with IBD (either in the faeces or adherent to the mucosa) have repeatedly reported a decrease in usually dominant bacteria, especially those from the dominant phylum Firmicutes. A decrease in the biodiversity of Firmicutes has been observed in CD, while a recent study has shown that a decrease in Firmicutes, especially Faecalibacterium prausnitzii, was associated with CD and the post-operative recurrence of CD lesions in the ileum. Taken together, these results suggest that dysbiosis, or an imbalance within the (dominant) intestinal microbiota, may favour IBD. PMID:20203504

  6. Prevention of bacterial foodborne disease using nanobiotechnology

    PubMed Central

    Billington, Craig; Hudson, J Andrew; D’Sa, Elaine

    2014-01-01

    Foodborne disease is an important source of expense, morbidity, and mortality for society. Detection and control constitute significant components of the overall management of foodborne bacterial pathogens, and this review focuses on the use of nanosized biological entities and molecules to achieve these goals. There is an emphasis on the use of organisms called bacteriophages (phages: viruses that infect bacteria), which are increasingly being used in pathogen detection and biocontrol applications. Detection of pathogens in foods by conventional techniques is time-consuming and expensive, although it can also be sensitive and accurate. Nanobiotechnology is being used to decrease detection times and cost through the development of biosensors, exploiting specific cell-recognition properties of antibodies and phage proteins. Although sensitivity per test can be excellent (eg, the detection of one cell), the very small volumes tested mean that sensitivity per sample is less compelling. An ideal detection method needs to be inexpensive, sensitive, and accurate, but no approach yet achieves all three. For nanobiotechnology to displace existing methods (culture-based, antibody-based rapid methods, or those that detect amplified nucleic acid) it will need to focus on improving sensitivity. Although manufactured nonbiological nanoparticles have been used to kill bacterial cells, nanosized organisms called phages are increasingly finding favor in food safety applications. Phages are amenable to protein and nucleic acid labeling, and can be very specific, and the typical large “burst size” resulting from phage amplification can be harnessed to produce a rapid increase in signal to facilitate detection. There are now several commercially available phages for pathogen control, and many reports in the literature demonstrate efficacy against a number of foodborne pathogens on diverse foods. As a method for control of pathogens, nanobiotechnology is therefore flourishing

  7. Host Antimicrobial Peptides in Bacterial Homeostasis and Pathogenesis of Disease

    PubMed Central

    Heimlich, Derek R.; Harrison, Alistair; Mason, Kevin M.

    2014-01-01

    Innate immune responses function as a first line of host defense against the development of bacterial infection, and in some cases to preserve the sterility of privileged sites in the human host. Bacteria that enter these sites must counter host responses for colonization. From the host’s perspective, the innate immune system works expeditiously to minimize the bacterial threat before colonization and subsequent dysbiosis. The multifactorial nature of disease further challenges predictions of how each independent variable influences bacterial pathogenesis. From bacterial colonization to infection and through disease, the microenvironments of the host are in constant flux as bacterial and host factors contribute to changes at the host-pathogen interface, with the host attempting to eradicate bacteria and the bacteria fighting to maintain residency. A key component of this innate host response towards bacterial infection is the production of antimicrobial peptides (AMPs). As an early component of the host response, AMPs modulate bacterial load and prevent establishment of infection. Under quiescent conditions, some AMPs are constitutively expressed by the epithelium. Bacterial infection can subsequently induce production of other AMPs in an effort to maintain sterility, or to restrict colonization. As demonstrated in various studies, the absence of a single AMP can influence pathogenesis, highlighting the importance of AMP concentration in maintaining homeostasis. Yet, AMPs can increase bacterial virulence through the co-opting of the peptides or alteration of bacterial virulence gene expression. Further, bacterial factors used to subvert AMPs can modify host microenvironments and alter colonization of the residential flora that principally maintain homeostasis. Thus, the dynamic interplay between host defense peptides and bacterial factors produced to quell peptide activity play a critical role in the progression and outcome of disease. PMID:26029470

  8. Concurrent Infections (Parasitism and Bacterial Disease) in Tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most laboratory disease studies in tilapia to date have focused on a single parasite or a single bacterial pathogen. In intensive tilapia aquaculture, the reality of a single disease agent resulting in death-loss may be small. More likely, multiple disease agents are present (i.e., parasites, bacter...

  9. Relationship between antigen concentration and bacterial load in Pacific salmon with bacterial kidney disease.

    PubMed

    Hamel, Owen S; Anderson, James J

    2002-08-29

    Using data collected to test spawning female Pacific salmon (Oncorhynchus kisutch and O. tshawytscha for the presence and severity of bacterial kidney disease (BKD), a mathematical model of the relationship between bacterial load and antigen concentration in tissues and ovarian fluid is developed. Renibacterium salmoninarum, the causative agent of BKD, secretes large amounts of a 57 kDa protein ('p57'), its major soluble antigen, which eventually breaks down or is otherwise removed from free circulation. Bacterial load and soluble antigen concentration in tissues are strong indicators of fish health, while in ovarian fluid they are predictors of the success of offspring. Model results indicate either an exponentially increasing antigen removal rate or an exponentially decreasing per-bacterium antigen secretion rate with increasing antigen concentration. Possible mechanisms underlying the observed relationship include a nonlinear increasing autolytic rate of the 'p57' antigen and a bacterium-antigen interaction threshold which prevents bacterial antigen secretion. PMID:12363089

  10. Emerging infectious diseases with cutaneous manifestations: Viral and bacterial infections.

    PubMed

    Nawas, Zeena Y; Tong, Yun; Kollipara, Ramya; Peranteau, Andrew J; Woc-Colburn, Laila; Yan, Albert C; Lupi, Omar; Tyring, Stephen K

    2016-07-01

    Given increased international travel, immigration, and climate change, bacterial and viral infections that were once unrecognized or uncommon are being seen more frequently in the Western Hemisphere. A delay in diagnosis and treatment of these diseases can lead to significant patient morbidity and mortality. However, the diagnosis and management of these infections is fraught with a lack of consistency because there is a dearth of dermatology literature on the cutaneous manifestations of these infections. We review the epidemiology, cutaneous manifestations, diagnosis, and management of these emerging bacterial and viral diseases. PMID:27317512

  11. Bacterial persistence and expression of disease.

    PubMed Central

    Domingue, G J; Woody, H B

    1997-01-01

    A considerable body of experimental and clinical evidence supports the concept that difficult-to-culture and dormant bacteria are involved in latency of infection and that these persistent bacteria may be pathogenic. This review includes details on the diverse forms and functions of individual bacteria and attempts to make this information relevant to the care of patients. A series of experimental studies involving host-bacterium interactions illustrates the probability that most bacteria exposed to a deleterious host environment can assume a form quite different from that of a free-living bacterium. A hypothesis is offered for a kind of reproductive cycle of morphologically aberrant bacteria as a means to relate their diverse tissue forms to each other. Data on the basic biology of persistent bacteria are correlated with expression of disease and particularly the mechanisms of both latency and chronicity that typify certain infections. For example, in certain streptococcal and nocardial infections, it has been clearly established that wall-defective forms can be induced in a suitable host. These organisms can survive and persist in a latent state within the host, and they can cause pathologic responses compatible with disease. A series of cases illustrating idiopathic conditions in which cryptic bacteria have been implicated in the expression of disease is presented. These conditions include nephritis, rheumatic fever, aphthous stomatitis, idiopathic hematuria, Crohn's disease, and mycobacterial infections. By utilizing PCR, previously nonculturable bacilli have been identified in patients with Whipple's disease and bacillary angiomatosis. Koch's postulates may have to be redefined in terms of molecular data when dormant and nonculturable bacteria are implicated as causative agents of mysterious diseases. PMID:9105757

  12. The sinonasal bacterial microbiome in health and disease

    PubMed Central

    Ramakrishnan, Vijay R.; Hauser, Leah J.; Frank, Daniel N.

    2016-01-01

    Purpose of review The development of culture-independent bacterial DNA sequencing techniques and integration into research practice has led to a burgeoning interest in the microbiome and its relevance to human health and disease. Introduction into the study of chronic rhinosinusitis in the past few years has shaped current thinking on the role of bacteria in the disease process. Recent findings Rich and diverse populations of bacteria inhabit the sinonasal cavity at all times. Decreased bacterial richness and diversity may be associated with disease state and outcomes. Summary Although there is much to be explored, the sinus microbiome appears to have potentially promising roles in many aspects of sinus health and disease. PMID:26575518

  13. Bacterial Leaf Spot of Parsley: Characterization of a New Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, a severe leaf spot disease on parsley has occurred throughout central coastal California and particularly in Monterey County. Two different bacterial pathogens (Pseudomonas syringae pv. apii, and P. syringae pv. coriandricola) have been associated these outbreaks on parsley. Our research...

  14. Bacterial symbiosis in arthropods and the control of disease transmission.

    PubMed Central

    Beard, C. B.; Durvasula, R. V.; Richards, F. F.

    1998-01-01

    Bacterial symbionts may be used as vehicles for expressing foreign genes in arthropods. Expression of selected genes can render an arthropod incapable of transmitting a second microorganism that is pathogenic for humans and is an alternative approach to the control of arthropod-borne diseases. We discuss the rationale for this alternative approach, its potential applications and limitations, and the regulatory concerns that may arise from its use in interrupting disease transmission in humans and animals. PMID:9866734

  15. Dissection of Bacterial Wilt on Medicago truncatula Revealed Two Type III Secretion System Effectors Acting on Root Infection Process and Disease Development[C][W][OA

    PubMed Central

    Turner, Marie; Jauneau, Alain; Genin, Stéphane; Tavella, Marie-José; Vailleau, Fabienne; Gentzbittel, Laurent; Jardinaud, Marie-Françoise

    2009-01-01

    Ralstonia solanacearum is the causal agent of the devastating bacterial wilt disease, which colonizes susceptible Medicago truncatula via the intact root tip. Infection involves four steps: appearance of root tip symptoms, root tip cortical cell invasion, vessel colonization, and foliar wilting. We examined this pathosystem by in vitro inoculation of intact roots of susceptible or resistant M. truncatula with the pathogenic strain GMI1000. The infection process was type III secretion system dependent and required two type III effectors, Gala7 and AvrA, which were shown to be involved at different stages of infection. Both effectors were involved in development of root tip symptoms, and Gala7 was the main determinant for bacterial invasion of cortical cells. Vessel invasion depended on the host genetic background and was never observed in the resistant line. The invasion of the root tip vasculature in the susceptible line caused foliar wilting. The avrA mutant showed reduced aggressiveness in all steps of the infection process, suggesting a global role in R. solanacearum pathogenicity. The roles of these two effectors in subsequent stages were studied using an assay that bypassed the penetration step; with this assay, the avrA mutant showed no effect compared with the GMI1000 strain, indicating that AvrA is important in early stages of infection. However, later disease symptoms were reduced in the gala7 mutant, indicating a key role in later stages of infection. PMID:19493968

  16. Effect of foliar application of antibiotics and gibberellic acid on the rhizosphre microflora of pea, infected with Verticillium dahliae.

    PubMed

    Ramarao, P; Isaac, I

    1980-01-01

    A study was made of the effects of foliar spray of bacitracin, chloramphenicol and gibberellic acid on the rhizosphere microflora of pea seedlings (Pisum sativum L.) infected with Verticillium dahliae. The antibiotics increased fungus and actinomycete counts and reduced the bacterial populations in the rhizosphere. Gibberellic acid at 10 ppm concentration reduced all three groups of microorganisms while at 100 ppm fungi and actinomycetes increased slightly. Invariably the rhizosphere effect was as follows: bacteria leads to fungi leads to actinomycetes. Foliar sprays also affected percentage occurrence of particular genera of fungi in the rhizosphere; for example, Trichoderma spp. were stimulated by all the treatments, the maximum being with 10 ppm gibberellic acid, even though the total fungus count was reduced. The disease severity was markedly reduced by foliar sprays. PMID:7191387

  17. Bacterial Intestinal Superinfections in Inflammatory Bowel Diseases Beyond Clostridum difficile.

    PubMed

    Lobatón, Triana; Domènech, Eugeni

    2016-07-01

    Besides genetics and environmental factors, intestinal microbiota seem to play a major role in the pathogenesis of inflammatory bowel diseases. For many decades, it has been said that some enteropathogens may even trigger both inflammatory bowel disease development and disease flares. For this reason, stool testing had been performed in inflammatory bowel disease flares but current guidelines only recommend to rule out Clostridium difficile infection and there is no clear advice for other enteropathogens given that the scarce available evidence points at a low prevalence of this sort of intestinal superinfections with no clear impact on disease course. The present article reviews the current knowledge about the role of bacterial enteropathogens on disease pathogenesis and flares beyond C. difficile. PMID:27104824

  18. Markers of bacterial translocation in end-stage liver disease.

    PubMed

    Koutsounas, Ioannis; Kaltsa, Garyfallia; Siakavellas, Spyros I; Bamias, Giorgos

    2015-09-18

    Bacterial translocation (BT) refers to the passage of viable bacteria or bacterial products from the intestinal lumen, through the intestinal epithelium, into the systemic circulation and extraintestinal locations. The three principal mechanisms that are thought to be involved in BT include bacterial overgrowth, disruption of the gut mucosal barrier and an impaired host defence. BT is commonly observed in liver cirrhosis and has been shown to play an important role in the pathogenesis of the complications of end stage liver disease, including infections as well as hepatic encephalopathy and hepatorenal syndrome. Due to the importance of BT in the natural history of cirrhosis, there is intense interest for the discovery of biomarkers of BT. To date, several such candidates have been proposed, which include bacterial DNA, soluble CD14, lipopolysaccharides endotoxin, lipopolysaccharide-binding protein, calprotectin and procalcitonin. Studies on the association of these markers with BT have demonstrated not only promising data but, oftentimes, contradictory results. As a consequence, currently, there is no optimal marker that may be used in clinical practice as a surrogate for the presence of BT. PMID:26380651

  19. Markers of bacterial translocation in end-stage liver disease

    PubMed Central

    Koutsounas, Ioannis; Kaltsa, Garyfallia; Siakavellas, Spyros I; Bamias, Giorgos

    2015-01-01

    Bacterial translocation (BT) refers to the passage of viable bacteria or bacterial products from the intestinal lumen, through the intestinal epithelium, into the systemic circulation and extraintestinal locations. The three principal mechanisms that are thought to be involved in BT include bacterial overgrowth, disruption of the gut mucosal barrier and an impaired host defence. BT is commonly observed in liver cirrhosis and has been shown to play an important role in the pathogenesis of the complications of end stage liver disease, including infections as well as hepatic encephalopathy and hepatorenal syndrome. Due to the importance of BT in the natural history of cirrhosis, there is intense interest for the discovery of biomarkers of BT. To date, several such candidates have been proposed, which include bacterial DNA, soluble CD14, lipopolysaccharides endotoxin, lipopolysaccharide-binding protein, calprotectin and procalcitonin. Studies on the association of these markers with BT have demonstrated not only promising data but, oftentimes, contradictory results. As a consequence, currently, there is no optimal marker that may be used in clinical practice as a surrogate for the presence of BT. PMID:26380651

  20. Modelling Wheat Growth and Yield Losses from Late Epidemics of Foliar Diseases using Loss of Green Leaf Area per Layer and Pre-anthesis Reserves

    PubMed Central

    Bancal, Marie-Odile; Robert, Corinne; Ney, Bertrand

    2007-01-01

    Background and Aims Crop protection strategies, based on preventing quantitative crop losses rather than pest outbreaks, are being developed as a promising way to reduce fungicide use. The Bastiaans' model was applied to winter wheat crops (Triticum aestivum) affected by leaf rust (Puccinia triticina) and Septoria tritici blotch (STB; Mycosphaerella graminicola) under a range of crop management conditions. This study examined (a) whether green leaf area per layer accurately accounts for growth loss; and (b) whether from growth loss it is possible to derive yield loss accurately and simply. Methods Over 5 years of field experiments, numerous green leaf area dynamics were analysed during the post-anthesis period on wheat crops using natural aerial epidemics of leaf rust and STB. Key Results When radiation use efficiency (RUE) was derived from bulk green leaf area index (GLAI), RUEbulk was hardly accurate and exhibited large variations among diseased wheat crops, thus extending outside the biological range. In contrast, when RUE was derived from GLAI loss per layer, RUElayer was a more accurate calculation and fell within the biological range. In one situation out of 13, no significant shift in the RUElayer of diseased crops vs. healthy crops was observed. A single linear relationship linked yield to post-anthesis accumulated growth for all treatments. Its slope, not different from 1, suggests that the allocation of post-anthesis photosynthates to grains was not affected by the late occurring diseases under study. The mobilization of pre-anthesis reserves completely accounted for the intercept value. Conclusions The results strongly suggest that a simple model based on green leaf area per layer and pre-anthesis reserves can predict both growth and yield of wheat suffering from late epidemics of foliar diseases over a range of crop practices. It could help in better understanding how crop structure and reserve management contribute to tolerance of wheat genotypes to

  1. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

    PubMed

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-12-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs. PMID:27178300

  2. Association between Bacterial Infection and Peripheral Vascular Disease: A Review.

    PubMed

    Budzyński, Jacek; Wiśniewska, Joanna; Ciecierski, Marek; Kędzia, Anna

    2016-03-01

    There are an increasing number of data showing a clinically important association between bacterial infection and peripheral artery disease (PAD). Bacteria suspected of being involved in PAD pathogenesis are: periodontal bacteria, gut microbiota, Helicobacter pylori, and Chlamydia pneumoniae. Infectious agents may be involved in the pathogenesis of atherosclerosis via activation of a systemic or local host immunological response to contamination of extravascular tissues or the vascular wall, respectively. A systemic immunological reaction may damage vascular walls in the course of autoimmunological cross-reactions between anti-pathogen antibodies and host vascular antigens (immunological mimicry), pathogen burden mechanisms (nonspecific activation of inflammatory processes in the vascular wall), and neuroendocrine-immune cross-talk. Besides activating the inflammatory pathway, bacterial infection may trigger PAD progression or exacerbation by enhancement of platelet reactivity, by a stimulatory effect on von Willebrand factor binding, factor VIII, fibrinogen, P-selectin activation, disturbances in plasma lipids, increase in oxidative stress, and resistance to insulin. Local inflammatory host reaction and induction of atherosclerotic plaque progression and/or instability result mainly from atherosclerotic plaque colonization by microorganisms. Despite these premises, the role of bacterial infection in PAD pathogenesis should still be recognized as controversial, and randomized, controlled trials are required to evaluate the outcome of periodontal or gut bacteria modification (through diet, prebiotics, and probiotics) or eradication (using antibiotics) in hard and surrogate cardiovascular endpoints. PMID:26900306

  3. Limited fungicide applications affect foliar and fruit disease severity and phytochemical content of muscadine grape (Vitis rotundifolia Michx.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Berry rot diseases cause significant reductions in yield and quality of muscadine grapes, but these losses may be reduced significantly by fungicide applications. Four studies were conducted to explore the relationship between yield, disease control, berry quality, and phytochemical content followin...

  4. [Acute bacterial exacerbation of chronic obstructive pulmonary disease and biofilm].

    PubMed

    Legnani, Delfino

    2009-07-01

    The lower respiratory tract of patients affected by COPD is constantly colonized by pathogenic microrganisms such as H. influenzae, M. catarrhalis and S. pneumoniae. Role of bacterial colonization of big and small airways in patients affected by COPD is still unclear but it is likely to play a role in directly or indirectly maintaining the vicious circle of infection/inflammation. Colonizer pathogens are capable to stimulate mucus production, to alter the ciliary function by inducing dyskinesia and stasis; in addition, they represent a strong stimulus for neutrophils to come in the airways, which release elastase that, in turn, inhibit the mucus-ciliary function. The same pathogens are responsible for epithelial damage and chronic inflammation, by releasing neutrophilic elastase, leading to the damage progression and obstruction. Recent studies have also shown that infection sustained by H. influenzae is not limited to bronchial mucosa, i.e. surface epithelial cells, but that the pathogen is capable to penetrate cells, so spreading the infection in sub-epithelial cellular layers. In addition, the ability to produce biofilm is another possible defence mechanism which allows them to grow and colonise. Such a mechanism could in part explain the lack of response to antimicrobials and contribute to stimulation of parenchymal inflammatory response, the cause of pathological-anatomic damage which occurs in COPD. The impossibility to eradicate chronic infection and bacterial exacerbations of COPD are likely the elements that promt and worsen obstruction, so determining the disease's progression. PMID:19696555

  5. Bacterial differentiation, development and disease: mechanisms for survival

    PubMed Central

    Justice, Sheryl S.; Harrison, Alistair; Becknell, Brian; Mason, Kevin M.

    2014-01-01

    Bacteria have the exquisite ability to maintain a precise diameter, cell length and shape. The dimensions of bacteria size and shape are a classical metric in the distinction of bacterial species. Much of what we know about the particular morphology of any given species is the result of investigations of planktonic cultures. As we explore deeper into the natural habitats of bacteria, it is increasingly clear that bacteria can alter their morphology in response to the environment in which they reside. Specific morphologies are also becoming recognized as advantageous for survival in hostile environments. This is of particular importance in the context of both colonization and infection in the host. There are multiple examples of bacterial pathogens that use morphological changes as a mechanism for evasion of host immune responses and continued persistence. This review will focus on two systems where specific morphological changes are essential for persistence in animal models of human disease. We will also offer insight into the mechanism underlying the morphological changes and how these morphotypes aid in persistence. Additional examples of morphological changes associated with survival will be presented. PMID:25228010

  6. GSK3β and the control of infectious bacterial diseases

    PubMed Central

    Wang, Huizhi H.; Lamont, Richard J.; Kumar, Akhilesh; Scott, David A.

    2014-01-01

    Glycogen synthesis kinase 3β (GSK3β) has been shown to be a critical mediator of the intensity and direction of the innate immune system responding to bacterial stimuli. This review will focus on: (i) the central role of GSK3β in the regulation of pathogen-induced inflammatory responses through the regulation of pro- and anti-inflammatory cytokine production. (ii) The extensive ongoing efforts to exploit GSK3β for its therapeutic potential in the control of infectious diseases. (iii) The increasing evidence that specific pathogens target GSK3β-related pathways for immune evasion. A better understanding of complex bacterial–GSK3β interactions is likely to lead to more effective anti-inflammatory interventions and novel targets to circumvent pathogen colonization and survival. PMID:24618402

  7. Design and evaluation of a bacterial clinical infectious diseases ontology.

    PubMed

    Gordon, Claire L; Pouch, Stephanie; Cowell, Lindsay G; Boland, Mary Regina; Platt, Heather L; Goldfain, Albert; Weng, Chunhua

    2013-01-01

    With antimicrobial resistance increasing worldwide, there is a great need to use automated antimicrobial decision support systems (ADSSs) to lower antimicrobial resistance rates by promoting appropriate antimicrobial use. However, they are infrequently used mostly because of their poor interoperability with different health information technologies. Ontologies can augment portable ADSSs by providing an explicit knowledge representation for biomedical entities and their relationships, helping to standardize and integrate heterogeneous data resources. We developed a bacterial clinical infectious diseases ontology (BCIDO) using Protégé-OWL. BCIDO defines a controlled terminology for clinical infectious diseases along with domain knowledge commonly used in hospital settings for clinical infectious disease treatment decision-making. BCIDO has 599 classes and 2355 object properties. Terms were imported from or mapped to Systematized Nomenclature of Medicine, Unified Medical Language System, RxNorm and National Center for Bitechnology Information Organismal Classification where possible. Domain expert evaluation using the "laddering" technique, ontology visualization, and clinical notes and scenarios, confirmed the correctness and potential usefulness of BCIDO. PMID:24551353

  8. Design and Evaluation of a Bacterial Clinical Infectious Diseases Ontology

    PubMed Central

    Gordon, Claire L.; Pouch, Stephanie; Cowell, Lindsay G.; Boland, Mary Regina; Platt, Heather L.; Goldfain, Albert; Weng, Chunhua

    2013-01-01

    With antimicrobial resistance increasing worldwide, there is a great need to use automated antimicrobial decision support systems (ADSSs) to lower antimicrobial resistance rates by promoting appropriate antimicrobial use. However, they are infrequently used mostly because of their poor interoperability with different health information technologies. Ontologies can augment portable ADSSs by providing an explicit knowledge representation for biomedical entities and their relationships, helping to standardize and integrate heterogeneous data resources. We developed a bacterial clinical infectious diseases ontology (BCIDO) using Protégé-OWL. BCIDO defines a controlled terminology for clinical infectious diseases along with domain knowledge commonly used in hospital settings for clinical infectious disease treatment decision-making. BCIDO has 599 classes and 2355 object properties. Terms were imported from or mapped to Systematized Nomenclature of Medicine, Unified Medical Language System, RxNorm and National Center for Bitechnology Information Organismal Classification where possible. Domain expert evaluation using the “laddering” technique, ontology visualization, and clinical notes and scenarios, confirmed the correctness and potential usefulness of BCIDO. PMID:24551353

  9. Host–Bacterial Symbiosis in Health and Disease

    PubMed Central

    Chow, Janet; Lee, S. Melanie; Shen, Yue; Khosravi, Arya; Mazmanian, Sarkis K.

    2011-01-01

    All animals live in symbiosis. Shaped by eons of co-evolution, host-bacterial associations have developed into prosperous relationships creating mechanisms for mutual benefits to both microbe and host. No better example exists in biology than the astounding numbers of bacteria harbored by the lower gastrointestinal tract of mammals. The mammalian gut represents a complex ecosystem consisting of an extraordinary number of resident commensal bacteria existing in homeostasis with the host’s immune system. Most impressive about this relationship may be the concept that the host not only tolerates, but has evolved to require colonization by beneficial microorganisms, known as commensals, for various aspects of immune development and function. The microbiota provides critical signals that promote maturation of immune cells and tissues, leading to protection from infections by pathogens. Gut bacteria also appear to contribute to non-infectious immune disorders such as inflammatory bowel disease and autoimmunity. How the microbiota influences host immune responses is an active area of research with important implications for human health. This review synthesizes emerging findings and concepts that describe the mutualism between the microbiota and mammals, specifically emphasizing the role of gut bacteria in shaping an immune response that mediates the balance between health and disease. Unlocking how beneficial bacteria affect the development of the immune system may lead to novel and natural therapies based on harnessing the immunomodulatory properties of the microbiota. PMID:21034976

  10. Partitioning of Bacterial Communities between Seawater and Healthy, Black Band Diseased, and Dead Coral Surfaces

    PubMed Central

    Frias-Lopez, Jorge; Zerkle, Aubrey L.; Bonheyo, George T.; Fouke, Bruce W.

    2002-01-01

    Distinct partitioning has been observed in the composition and diversity of bacterial communities inhabiting the surface and overlying seawater of three coral species infected with black band disease (BBD) on the southern Caribbean island of Curaçao, Netherlands Antilles. PCR amplification and sequencing of bacterial 16S rRNA genes (rDNA) with universally conserved primers have identified over 524 unique bacterial sequences affiliated with 12 bacterial divisions. The molecular sequences exhibited less than 5% similarity in bacterial community composition between seawater and the healthy, black band diseased, and dead coral surfaces. The BBD bacterial mat rapidly migrates across and kills the coral tissue. Clone libraries constructed from the BBD mat were comprised of eight bacterial divisions and 13% unknowns. Several sequences representing bacteria previously found in other marine and terrestrial organisms (including humans) were isolated from the infected coral surfaces, including Clostridium spp., Arcobacter spp., Campylobacter spp., Cytophaga fermentans, Cytophaga columnaris, and Trichodesmium tenue. PMID:11976091

  11. Treatment of sexually transmitted bacterial diseases in pregnant women.

    PubMed

    Donders, G G

    2000-03-01

    twice daily for 7 days as earlier fears of teratogenesis in humans have not been confirmed by recent data. Bacterial vaginosis is also associated with preterm delivery in certain risk groups, such as women with a history of preterm birth or of low maternal weight. Such an association is yet to be convincingly proven in other women. The current advice is to treat only women diagnosed with bacterial vaginosis who also present other risk factors for preterm delivery. The treatment of choice is oral metronidazole 1 g/day for 5 days. The possible reduction of preterm birth by vaginally applied metronidazole or clindamycin is still under investigation. In general, both test of cure and re-testing after several weeks are advisable in most pregnant patients with STDs, because partner notification and treatment are likely to be less efficient than outside pregnancy and the impact of inadequately treated or recurrent disease is greater because of the added risk to the fetus. Every diagnosis of an STD warrants a full screen for concomitant genital disease. Most ulcerative genital infections, as well as abnormal vaginal flora and bacterial vaginosis, increase the sexual transmission efficiency of HIV, necessitating even more stringent screening for and treating of STD during pregnancy. PMID:10776830

  12. The olive knot disease as a model to study the role of interspecies bacterial communities in plant disease

    PubMed Central

    Buonaurio, Roberto; Moretti, Chiaraluce; da Silva, Daniel Passos; Cortese, Chiara; Ramos, Cayo; Venturi, Vittorio

    2015-01-01

    There is an increasing interest in studying interspecies bacterial interactions in diseases of animals and plants as it is believed that the great majority of bacteria found in nature live in complex communities. Plant pathologists have thus far mainly focused on studies involving single species or on their interactions with antagonistic competitors. A bacterial disease used as model to study multispecies interactions is the olive knot disease, caused by Pseudomonas savastanoi pv. savastanoi (Psv). Knots caused by Psv in branches and other aerial parts of the olive trees are an ideal niche not only for the pathogen but also for many other plant-associated bacterial species, mainly belonging to the genera Pantoea, Pectobacterium, Erwinia, and Curtobacterium. The non-pathogenic bacterial species Erwinia toletana, Pantoea agglomerans, and Erwinia oleae, which are frequently isolated inside the olive knots, cooperate with Psv in modulating the disease severity. Co-inoculations of these species with Psv result in bigger knots and better bacterial colonization when compared to single inoculations. Moreover, harmless bacteria co-localize with the pathogen inside the knots, indicating the formation of stable bacterial consortia that may facilitate the exchange of quorum sensing signals and metabolites. Here we discuss the possible role of bacterial communities in the establishment and development of olive knot disease, which we believe could be taking place in many other bacterial plant diseases. PMID:26113855

  13. The olive knot disease as a model to study the role of interspecies bacterial communities in plant disease.

    PubMed

    Buonaurio, Roberto; Moretti, Chiaraluce; da Silva, Daniel Passos; Cortese, Chiara; Ramos, Cayo; Venturi, Vittorio

    2015-01-01

    There is an increasing interest in studying interspecies bacterial interactions in diseases of animals and plants as it is believed that the great majority of bacteria found in nature live in complex communities. Plant pathologists have thus far mainly focused on studies involving single species or on their interactions with antagonistic competitors. A bacterial disease used as model to study multispecies interactions is the olive knot disease, caused by Pseudomonas savastanoi pv. savastanoi (Psv). Knots caused by Psv in branches and other aerial parts of the olive trees are an ideal niche not only for the pathogen but also for many other plant-associated bacterial species, mainly belonging to the genera Pantoea, Pectobacterium, Erwinia, and Curtobacterium. The non-pathogenic bacterial species Erwinia toletana, Pantoea agglomerans, and Erwinia oleae, which are frequently isolated inside the olive knots, cooperate with Psv in modulating the disease severity. Co-inoculations of these species with Psv result in bigger knots and better bacterial colonization when compared to single inoculations. Moreover, harmless bacteria co-localize with the pathogen inside the knots, indicating the formation of stable bacterial consortia that may facilitate the exchange of quorum sensing signals and metabolites. Here we discuss the possible role of bacterial communities in the establishment and development of olive knot disease, which we believe could be taking place in many other bacterial plant diseases. PMID:26113855

  14. Efficacy and safety of lomefloxacin on bacterial extraocular disease in the horse

    PubMed Central

    HIDAKA, Shuhei; KOBAYASHI, Mitsutoshi; ANDO, Kunihide; FUJII, Yoshikazu

    2015-01-01

    Lomefloxacin is a broad-spectrum fluoroquinolone antibiotic used for the treatment of bacterial extraocular disease. This study investigated the efficacy and safety of lomefloxacin eye drops for bacterial extraocular disease in horses. Lomefloxacin ophthalmic solution (0.3%) was instilled three times daily for 2–5 days in 65 horses diagnosed with bacterial extraocular disease based on clinical findings. Clinical observations and bacteriological examinations were performed at the start of treatment, 2 and 5 days after the start of treatment, and at the discontinuation or termination of treatment. Of the 65 horses, 64 were positive for bacteria, and 22 bacterial genera and 47 bacterial species were identified. The efficacy of lomefloxacin was evaluated in 63 horses; one horse with a negative culture and another with suspected bacterial contamination were excluded. Lomefloxacin was considered to be clinically effective in 54 horses. The major bacterial species identified were Staphylococcus aureus, Streptococcus equi subsp. zooepidemicus, Acinetobacter lwoffii, Staphylococcus xylosus, Staphylococcus vitulinus, Enterobacter agglomerans, Flavimonas oryzihabitans and Staphylococcus sciuri, with a cumulative disappearance rate of 80% or more at the termination of instillation. Excluding one horse that did not undergo a bacteriological examination, the remaining 62 horses were assessed for bacteriological outcome. Full or partial bacterial clearance was detected in 95% or more of the 62 horses. One of the 65 horses reported adverse events that had no causal relation with the eye drops. Our results showed that lomefloxacin is safe and effective for the treatment of bacterial extraocular disease in horses. PMID:25787926

  15. Efficacy and safety of lomefloxacin on bacterial extraocular disease in the horse.

    PubMed

    Hidaka, Shuhei; Kobayashi, Mitsutoshi; Ando, Kunihide; Fujii, Yoshikazu

    2015-07-01

    Lomefloxacin is a broad-spectrum fluoroquinolone antibiotic used for the treatment of bacterial extraocular disease. This study investigated the efficacy and safety of lomefloxacin eye drops for bacterial extraocular disease in horses. Lomefloxacin ophthalmic solution (0.3%) was instilled three times daily for 2-5 days in 65 horses diagnosed with bacterial extraocular disease based on clinical findings. Clinical observations and bacteriological examinations were performed at the start of treatment, 2 and 5 days after the start of treatment, and at the discontinuation or termination of treatment. Of the 65 horses, 64 were positive for bacteria, and 22 bacterial genera and 47 bacterial species were identified. The efficacy of lomefloxacin was evaluated in 63 horses; one horse with a negative culture and another with suspected bacterial contamination were excluded. Lomefloxacin was considered to be clinically effective in 54 horses. The major bacterial species identified were Staphylococcus aureus, Streptococcus equi subsp. zooepidemicus, Acinetobacter lwoffii, Staphylococcus xylosus, Staphylococcus vitulinus, Enterobacter agglomerans, Flavimonas oryzihabitans and Staphylococcus sciuri, with a cumulative disappearance rate of 80% or more at the termination of instillation. Excluding one horse that did not undergo a bacteriological examination, the remaining 62 horses were assessed for bacteriological outcome. Full or partial bacterial clearance was detected in 95% or more of the 62 horses. One of the 65 horses reported adverse events that had no causal relation with the eye drops. Our results showed that lomefloxacin is safe and effective for the treatment of bacterial extraocular disease in horses. PMID:25787926

  16. Changes in intestinal bacterial communities are closely associated with shrimp disease severity.

    PubMed

    Xiong, Jinbo; Wang, Kai; Wu, Jinfeng; Qiuqian, Linglin; Yang, Kunjie; Qian, Yunxia; Zhang, Demin

    2015-08-01

    Increasing evidence has revealed a close association between intestinal bacterial communities and human health. However, given that host phylogeny shapes the composition of intestinal microbiota, it is unclear whether changes in intestinal microbiota structure in relation to shrimp health status. In this study, we collected shrimp and seawater samples from ponds with healthy and diseased shrimps to understand variations in bacterial communities among habitats (water and intestine) and/or health status. The bacterial communities were clustered according to the original habitat and health status. Habitat and health status constrained 14.6 and 7.7 % of the variation in bacterial communities, respectively. Changes in shrimp intestinal bacterial communities occurred in parallel with changes in disease severity, reflecting the transition from a healthy to a diseased state. This pattern was further evidenced by 38 bacterial families that were significantly different in abundance between healthy and diseased shrimps; moderate changes were observed in shrimps with sub-optimal health. In addition, within a given bacterial family, the patterns of enrichment or decrease were consistent with the known functions of those bacteria. Furthermore, the identified 119 indicator taxa exhibited a discriminative pattern similar to the variation in the community as a whole. Overall, this study suggests that changes in intestinal bacterial communities are closely associated with the severity of shrimp disease and that indicator taxa can be used to evaluate shrimp health status. PMID:25947250

  17. The Evolution of Fungicide Resistance Resulting from Combinations of Foliar-Acting Systemic Seed Treatments and Foliar-Applied Fungicides: A Modeling Analysis

    PubMed Central

    Kitchen, James L.; van den Bosch, Frank; Paveley, Neil D.; Helps, Joseph; van den Berg, Femke

    2016-01-01

    For the treatment of foliar diseases of cereals, fungicides may be applied as foliar sprays or systemic seed treatments which are translocated to leaves. Little research has been done to assess the resistance risks associated with foliar-acting systemic seed treatments when used alone or in combination with foliar sprays, even though both types of treatment may share the same mode of action. It is therefore unknown to what extent adding a systemic seed treatment to a foliar spray programme poses an additional resistance risk and whether in the presence of a seed treatment additional resistance management strategies (such as limiting the total number of treatments) are necessary to limit the evolution of fungicide-resistance. A mathematical model was developed to simulate an epidemic and the resistance evolution of Zymoseptoria tritici on winter wheat, which was used to compare different combinations of seed and foliar treatments by calculating the fungicide effective life, i.e. the number of years before effective disease control is lost to resistance. A range of parameterizations for the seed treatment fungicide and different fungicide uptake models were compared. Despite the different parameterizations, the model consistently predicted the same trends in that i) similar levels of efficacy delivered either by a foliar-acting seed treatment, or a foliar application, resulted in broadly similar resistance selection, ii) adding a foliar-acting seed treatment to a foliar spray programme increased resistance selection and usually decreased effective life, and iii) splitting a given total dose—by adding a seed treatment to foliar treatments, but decreasing dose per treatment—gave effective lives that were the same as, or shorter than those given by the spray programme alone. For our chosen plant-pathogen-fungicide system, the model results suggest that to effectively manage selection for fungicide-resistance, foliar acting systemic seed treatments should be included

  18. The Evolution of Fungicide Resistance Resulting from Combinations of Foliar-Acting Systemic Seed Treatments and Foliar-Applied Fungicides: A Modeling Analysis.

    PubMed

    Kitchen, James L; van den Bosch, Frank; Paveley, Neil D; Helps, Joseph; van den Berg, Femke

    2016-01-01

    For the treatment of foliar diseases of cereals, fungicides may be applied as foliar sprays or systemic seed treatments which are translocated to leaves. Little research has been done to assess the resistance risks associated with foliar-acting systemic seed treatments when used alone or in combination with foliar sprays, even though both types of treatment may share the same mode of action. It is therefore unknown to what extent adding a systemic seed treatment to a foliar spray programme poses an additional resistance risk and whether in the presence of a seed treatment additional resistance management strategies (such as limiting the total number of treatments) are necessary to limit the evolution of fungicide-resistance. A mathematical model was developed to simulate an epidemic and the resistance evolution of Zymoseptoria tritici on winter wheat, which was used to compare different combinations of seed and foliar treatments by calculating the fungicide effective life, i.e. the number of years before effective disease control is lost to resistance. A range of parameterizations for the seed treatment fungicide and different fungicide uptake models were compared. Despite the different parameterizations, the model consistently predicted the same trends in that i) similar levels of efficacy delivered either by a foliar-acting seed treatment, or a foliar application, resulted in broadly similar resistance selection, ii) adding a foliar-acting seed treatment to a foliar spray programme increased resistance selection and usually decreased effective life, and iii) splitting a given total dose-by adding a seed treatment to foliar treatments, but decreasing dose per treatment-gave effective lives that were the same as, or shorter than those given by the spray programme alone. For our chosen plant-pathogen-fungicide system, the model results suggest that to effectively manage selection for fungicide-resistance, foliar acting systemic seed treatments should be included as

  19. Foliar and tuber late blight resistance in a Solanum tuberosum potato mapping population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar and tuber resistance to Phytophthora infestans were evaluated in a mapping population (n=94) developed between two Solanum tuberosum breeding lines, NY121 x NY115. Foliar disease severity of the progeny clones was measured by the area under the disease progress curve (AUDPC) in field tests in...

  20. Restructuring of endophytic bacterial communities in grapevine yellows-diseased and recovered Vitis vinifera L. plants.

    PubMed

    Bulgari, Daniela; Casati, Paola; Crepaldi, Paola; Daffonchio, Daniele; Quaglino, Fabio; Brusetti, Lorenzo; Bianco, Piero Attilio

    2011-07-01

    Length heterogeneity-PCR assays, combined with statistical analyses, highlighted that the endophytic bacterial community associated with healthy grapevines was characterized by a greater diversity than that present in diseased and recovered plants. The findings suggest that phytoplasmas can restructure the bacterial community by selecting endophytic strains that could elicit a plant defense response. PMID:21622794

  1. Bacterial brown leaf spot of citrus, a new disease caused by Burkholderia andropogonis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new bacterial disease of citrus was recently identified in Florida and named as bacterial brown leaf spot (BBLS) of citrus. BBLS-infected citrus displayed flat, circular and brownish lesions with water-soaked margins surrounded by a chlorotic halo on leaves. Based on Biolog carbon source metabolic...

  2. Rainbow Trout (Oncorhynchus mykiss) resistance to columnaris disease is heritable and favorably correlated with bacterial cold water disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Columnaris disease (CD) is an emerging disease affecting rainbow trout aquaculture. Objectives were to estimate heritability of CD resistance in a line (ARS-Fp-R) selected 4 generations for improved bacterial cold water disease (BCWD) resistance; estimate genetic correlations among CD resistance, BC...

  3. INHERITANCE OF RESISTANCE IN STRAWBERRY TO BACTERIAL ANGUALAR LEAFSOPT DISEASE CAUSED BY XANTHOMONAS FRAGARIAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial angular leafspot disease (Xanthomonas fragariae Kennedy and King) of strawberry (Fragaria species and F. × ananassa Duch. cultivars) has become increasingly important to strawberry fruit and plant production. Strawberry cultivars and species vary in susceptibility to infection. However, ...

  4. CRACKING THE CODE: SELECTING FOR RESISTANCE AGAINST BACTERIAL COLD-WATER DISEASE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At the National Center for Cool and Cold Water Aquaculture (NCCCWA) reducing the negative impact of diseases on rainbow trout culture is a primary objective. Bacterial cold-water disease, a chronic disease of rainbow trout is caused by Flavobacterium psychrophilum. This bacterium also causes acute ...

  5. Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease.

    PubMed

    Hu, Yang; Zhang, Junli; Jia, Hongge; Sosso, Davide; Li, Ting; Frommer, Wolf B; Yang, Bing; White, Frank F; Wang, Nian; Jones, Jeffrey B

    2014-01-28

    Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector gene pthA4 or with the distinct yet biologically equivalent gene pthAw from strain XccA(w), induces two host genes, CsLOB1 and CsSWEET1, in a TAL effector-dependent manner. CsLOB1 is a member of the Lateral Organ Boundaries (LOB) gene family of transcription factors, and CsSWEET1 is a homolog of the SWEET sugar transporter and rice disease susceptibility gene. Both TAL effectors drive expression of CsLOB1 and CsSWEET1 promoter reporter gene fusions when coexpressed in citrus or Nicotiana benthamiana. Artificially designed TAL effectors directed to sequences in the CsLOB1 promoter region, but not the CsSWEET1 promoter, promoted pustule formation and higher bacterial leaf populations. Three additional distinct TAL effector genes, pthA*, pthB, and pthC, also direct pustule formation and expression of CsLOB1. Unlike pthA4 and pthAw, pthB and pthC do not promote the expression of CsSWEET1. CsLOB1 expression was associated with the expression of genes associated with cell expansion. The results indicate that CBC-inciting species of Xanthomonas exploit a single host disease susceptibility gene by altering the expression of an otherwise developmentally regulated gene using any one of a diverse set of TAL effector genes in the pathogen populations. PMID:24474801

  6. Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease

    PubMed Central

    Hu, Yang; Zhang, Junli; Jia, Hongge; Sosso, Davide; Li, Ting; Frommer, Wolf B.; Yang, Bing; White, Frank F.; Wang, Nian; Jones, Jeffrey B.

    2014-01-01

    Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector gene pthA4 or with the distinct yet biologically equivalent gene pthAw from strain XccAw, induces two host genes, CsLOB1 and CsSWEET1, in a TAL effector-dependent manner. CsLOB1 is a member of the Lateral Organ Boundaries (LOB) gene family of transcription factors, and CsSWEET1 is a homolog of the SWEET sugar transporter and rice disease susceptibility gene. Both TAL effectors drive expression of CsLOB1 and CsSWEET1 promoter reporter gene fusions when coexpressed in citrus or Nicotiana benthamiana. Artificially designed TAL effectors directed to sequences in the CsLOB1 promoter region, but not the CsSWEET1 promoter, promoted pustule formation and higher bacterial leaf populations. Three additional distinct TAL effector genes, pthA*, pthB, and pthC, also direct pustule formation and expression of CsLOB1. Unlike pthA4 and pthAw, pthB and pthC do not promote the expression of CsSWEET1. CsLOB1 expression was associated with the expression of genes associated with cell expansion. The results indicate that CBC-inciting species of Xanthomonas exploit a single host disease susceptibility gene by altering the expression of an otherwise developmentally regulated gene using any one of a diverse set of TAL effector genes in the pathogen populations. PMID:24474801

  7. Small intestinal bacterial overgrowth in dogs with chronic intestinal disease.

    PubMed

    Rutgers, H C; Batt, R M; Elwood, C M; Lamport, A

    1995-01-15

    Small intestinal bacterial overgrowth (SIBO) was diagnosed by quantitative bacterial culture of duodenal juice samples obtained endoscopically in 41 of 80 dogs that were admitted with chronic diarrhea, vomiting, or weight loss. Thirteen dogs had aerobic bacterial overgrowth, most frequently comprising Escherichia coli, staphylococci, and enterococci, and 28 dogs had mixed anaerobic overgrowth, most frequently including Clostridium and Bacteroides spp. Affected dogs comprised 23 breeds, including 10 German Shepherd Dogs and median age at diagnosis was 2 years (range, 6 months to 11 years). High serum folate and low serum cobalamin concentrations had fair specificity (79 and 87%, respectively), but low sensitivity (51 and 24%, respectively) in detecting SIBO. Histologic examination of duodenal biopsy specimens did not reveal abnormalities (26/41 dogs), or revealed mild to moderate lymphocytic (12/41) or eosinophilic (2/41) infiltrates, or lymphosarcoma (1/41). Oral antibiotic treatment was effective in 77% (23/30 dogs), but prolonged treatment (> 4 weeks) was required to control signs and prevent recurrence in 50% (15/30). Corticosteroids were used alone in a dog with eosinophilic enteritis and in combination with antibiotics in 4 dogs with marked gastrointestinal lymphocytic/plasmacytic infiltrates. This study suggested that SIBO may be observed in dogs of many breeds, without an obvious primary cause, and that, although results of indirect tests may be suggestive of SIBO, bacterial culture of duodenal juice samples remains necessary for definitive diagnosis. PMID:7751219

  8. Bacterial profiling of White Plague Disease in a comparative coral species framework.

    PubMed

    Roder, Cornelia; Arif, Chatchanit; Bayer, Till; Aranda, Manuel; Daniels, Camille; Shibl, Ahmed; Chavanich, Suchana; Voolstra, Christian R

    2014-01-01

    Coral reefs are threatened throughout the world. A major factor contributing to their decline is outbreaks and propagation of coral diseases. Due to the complexity of coral-associated microbe communities, little is understood in terms of disease agents, hosts and vectors. It is known that compromised health in corals is correlated with shifts in bacterial assemblages colonizing coral mucus and tissue. However, general disease patterns remain, to a large extent, ambiguous as comparative studies over species, regions, or diseases are scarce. Here, we compare bacterial assemblages of samples from healthy (HH) colonies and such displaying signs of White Plague Disease (WPD) of two different coral species (Pavona duerdeni and Porites lutea) from the same reef in Koh Tao, Thailand, using 16S rRNA gene microarrays. In line with other studies, we found an increase of bacterial diversity in diseased (DD) corals, and a higher abundance of taxa from the families that include known coral pathogens (Alteromonadaceae, Rhodobacteraceae, Vibrionaceae). In our comparative framework analysis, we found differences in microbial assemblages between coral species and coral health states. Notably, patterns of bacterial community structures from HH and DD corals were maintained over species boundaries. Moreover, microbes that differentiated the two coral species did not overlap with microbes that were indicative of HH and DD corals. This suggests that while corals harbor distinct species-specific microbial assemblages, disease-specific bacterial abundance patterns exist that are maintained over coral species boundaries. PMID:23924783

  9. Rainbow trout (Oncorhynchus mykiss) resistance to columnaris disease is heritable and favorably correlated with bacterial cold water disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Columnaris disease (CD), caused by Flabobacterium columnare, is an emerging disease affecting rainbow trout aquaculture. Objectives of this study were to 1) estimate heritability of innate CD resistance in a rainbow trout line (ARS-Fp-R) previously selected four generations for improved bacterial co...

  10. Bacterial profiling of White Plague Disease across corals and oceans indicates a conserved and distinct disease microbiome.

    PubMed

    Roder, Cornelia; Arif, Chatchanit; Daniels, Camille; Weil, Ernesto; Voolstra, Christian R

    2014-02-01

    Coral diseases are characterized by microbial community shifts in coral mucus and tissue, but causes and consequences of these changes are vaguely understood due to the complexity and dynamics of coral-associated bacteria. We used 16S rRNA gene microarrays to assay differences in bacterial assemblages of healthy and diseased colonies displaying White Plague Disease (WPD) signs from two closely related Caribbean coral species, Orbicella faveolata and Orbicella franksi. Analysis of differentially abundant operational taxonomic units (OTUs) revealed strong differences between healthy and diseased specimens, but not between coral species. A subsequent comparison to data from two Indo-Pacific coral species (Pavona duerdeni and Porites lutea) revealed distinct microbial community patterns associated with ocean basin, coral species and health state. Coral species were clearly separated by site, but also, the relatedness of the underlying bacterial community structures resembled the phylogenetic relationship of the coral hosts. In diseased samples, bacterial richness increased and putatively opportunistic bacteria were consistently more abundant highlighting the role of opportunistic conditions in structuring microbial community patterns during disease. Our comparative analysis shows that it is possible to derive conserved bacterial footprints of diseased coral holobionts that might help in identifying key bacterial species related to the underlying etiopathology. Furthermore, our data demonstrate that similar-appearing disease phenotypes produce microbial community patterns that are consistent over coral species and oceans, irrespective of the putative underlying pathogen. Consequently, profiling coral diseases by microbial community structure over multiple coral species might allow the development of a comparative disease framework that can inform on cause and relatedness of coral diseases. PMID:24350609

  11. Bacterial profiling of White Plague Disease across corals and oceans indicates a conserved and distinct disease microbiome

    PubMed Central

    Roder, Cornelia; Arif, Chatchanit; Daniels, Camille; Weil, Ernesto; Voolstra, Christian R

    2014-01-01

    Coral diseases are characterized by microbial community shifts in coral mucus and tissue, but causes and consequences of these changes are vaguely understood due to the complexity and dynamics of coral-associated bacteria. We used 16S rRNA gene microarrays to assay differences in bacterial assemblages of healthy and diseased colonies displaying White Plague Disease (WPD) signs from two closely related Caribbean coral species, Orbicella faveolata and Orbicella franksi. Analysis of differentially abundant operational taxonomic units (OTUs) revealed strong differences between healthy and diseased specimens, but not between coral species. A subsequent comparison to data from two Indo-Pacific coral species (Pavona duerdeni and Porites lutea) revealed distinct microbial community patterns associated with ocean basin, coral species and health state. Coral species were clearly separated by site, but also, the relatedness of the underlying bacterial community structures resembled the phylogenetic relationship of the coral hosts. In diseased samples, bacterial richness increased and putatively opportunistic bacteria were consistently more abundant highlighting the role of opportunistic conditions in structuring microbial community patterns during disease. Our comparative analysis shows that it is possible to derive conserved bacterial footprints of diseased coral holobionts that might help in identifying key bacterial species related to the underlying etiopathology. Furthermore, our data demonstrate that similar-appearing disease phenotypes produce microbial community patterns that are consistent over coral species and oceans, irrespective of the putative underlying pathogen. Consequently, profiling coral diseases by microbial community structure over multiple coral species might allow the development of a comparative disease framework that can inform on cause and relatedness of coral diseases. PMID:24350609

  12. Remote sensing of foliar chemistry

    NASA Technical Reports Server (NTRS)

    Curran, Paul J.

    1989-01-01

    Remotely sensed data are being used to estimate foliar chemical content. This paper reviews how stepwise multiple regression and deconvolution have been used to extract chemical information from foliar spectra, and concludes that both methods are useful, but neither is ideal. It is recommended that the focus of research be modeling in the long term and experimentation in the short term. Long-term research should increase our understanding of the interaction between radiation and foliar chemistry so that the focus of research can move from leaf model to canopy model to field experiment. Short-term research should aim to design experiments in which remotely sensed data are used to generate unambiguous and accurate estimates of foliar chemical content.

  13. Hydrogen Peroxide- and Nitric Oxide-mediated Disease Control of Bacterial Wilt in Tomato Plants

    PubMed Central

    Hong, Jeum Kyu; Kang, Su Ran; Kim, Yeon Hwa; Yoon, Dong June; Kim, Do Hoon; Kim, Hyeon Ji; Sung, Chang Hyun; Kang, Han Sol; Choi, Chang Won; Kim, Seong Hwan; Kim, Young Shik

    2013-01-01

    Reactive oxygen species (ROS) generation in tomato plants by Ralstonia solanacearum infection and the role of hydrogen peroxide (H2O2) and nitric oxide in tomato bacterial wilt control were demonstrated. During disease development of tomato bacterial wilt, accumulation of superoxide anion (O2−) and H2O2 was observed and lipid peroxidation also occurred in the tomato leaf tissues. High doses of H2O2and sodium nitroprusside (SNP) nitric oxide donor showed phytotoxicity to detached tomato leaves 1 day after petiole feeding showing reduced fresh weight. Both H2O2and SNP have in vitro antibacterial activities against R. solanacearum in a dose-dependent manner, as well as plant protection in detached tomato leaves against bacterial wilt by 106 and 107 cfu/ml of R. solanacearum. H2O2- and SNP-mediated protection was also evaluated in pots using soil-drench treatment with the bacterial inoculation, and relative ‘area under the disease progressive curve (AUDPC)’ was calculated to compare disease protection by H2O2 and/or SNP with untreated control. Neither H2O2 nor SNP protect the tomato seedlings from the bacterial wilt, but H2O2+ SNP mixture significantly decreased disease severity with reduced relative AUDPC. These results suggest that H2O2 and SNP could be used together to control bacterial wilt in tomato plants as bactericidal agents. PMID:25288967

  14. Coral transcriptome and bacterial community profiles reveal distinct Yellow Band Disease states in Orbicella faveolata

    PubMed Central

    Closek, Collin J; Sunagawa, Shinichi; DeSalvo, Michael K; Piceno, Yvette M; DeSantis, Todd Z; Brodie, Eoin L; Weber, Michele X; Voolstra, Christian R; Andersen, Gary L; Medina, Mónica

    2014-01-01

    Coral diseases impact reefs globally. Although we continue to describe diseases, little is known about the etiology or progression of even the most common cases. To examine a spectrum of coral health and determine factors of disease progression we examined Orbicella faveolata exhibiting signs of Yellow Band Disease (YBD), a widespread condition in the Caribbean. We used a novel combined approach to assess three members of the coral holobiont: the coral-host, associated Symbiodinium algae, and bacteria. We profiled three conditions: (1) healthy-appearing colonies (HH), (2) healthy-appearing tissue on diseased colonies (HD), and (3) diseased lesion (DD). Restriction fragment length polymorphism analysis revealed health state-specific diversity in Symbiodinium clade associations. 16S ribosomal RNA gene microarrays (PhyloChips) and O. faveolata complimentary DNA microarrays revealed the bacterial community structure and host transcriptional response, respectively. A distinct bacterial community structure marked each health state. Diseased samples were associated with two to three times more bacterial diversity. HD samples had the highest bacterial richness, which included components associated with HH and DD, as well as additional unique families. The host transcriptome under YBD revealed a reduced cellular expression of defense- and metabolism-related processes, while the neighboring HD condition exhibited an intermediate expression profile. Although HD tissue appeared visibly healthy, the microbial communities and gene expression profiles were distinct. HD should be regarded as an additional (intermediate) state of disease, which is important for understanding the progression of YBD. PMID:24950107

  15. Coral transcriptome and bacterial community profiles reveal distinct Yellow Band Disease states in Orbicella faveolata.

    PubMed

    Closek, Collin J; Sunagawa, Shinichi; DeSalvo, Michael K; Piceno, Yvette M; DeSantis, Todd Z; Brodie, Eoin L; Weber, Michele X; Voolstra, Christian R; Andersen, Gary L; Medina, Mónica

    2014-12-01

    Coral diseases impact reefs globally. Although we continue to describe diseases, little is known about the etiology or progression of even the most common cases. To examine a spectrum of coral health and determine factors of disease progression we examined Orbicella faveolata exhibiting signs of Yellow Band Disease (YBD), a widespread condition in the Caribbean. We used a novel combined approach to assess three members of the coral holobiont: the coral-host, associated Symbiodinium algae, and bacteria. We profiled three conditions: (1) healthy-appearing colonies (HH), (2) healthy-appearing tissue on diseased colonies (HD), and (3) diseased lesion (DD). Restriction fragment length polymorphism analysis revealed health state-specific diversity in Symbiodinium clade associations. 16S ribosomal RNA gene microarrays (PhyloChips) and O. faveolata complimentary DNA microarrays revealed the bacterial community structure and host transcriptional response, respectively. A distinct bacterial community structure marked each health state. Diseased samples were associated with two to three times more bacterial diversity. HD samples had the highest bacterial richness, which included components associated with HH and DD, as well as additional unique families. The host transcriptome under YBD revealed a reduced cellular expression of defense- and metabolism-related processes, while the neighboring HD condition exhibited an intermediate expression profile. Although HD tissue appeared visibly healthy, the microbial communities and gene expression profiles were distinct. HD should be regarded as an additional (intermediate) state of disease, which is important for understanding the progression of YBD. PMID:24950107

  16. Sensitive molecular diagnostic assays to mitigate the risks of asymptomatic bacterial diseases of plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our highly concentrated monoculture makes crops vulnerable to pests and diseases. An increase in emerging non-indigenous bacterial diseases pose a real threat to US agriculture. The USA has 100,000 miles of shoreline and 6,000 miles of border, making possible easy introduction of crop pests and di...

  17. IDENTIFICATION OF SOURCES OF RESISTENCE TO BACTERIAL ANGULAR LEAFSPOT DISEASE OF STRAWBERRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial angular leafspot disease (BALD) of cultivated strawberry, caused by the bacterium Xanthomonas fragariae, has become an increasingly serious disease problem. It is of particular concern because it is readily transmitted through asymptomatic nursery plants. Until now, there have been no s...

  18. Bacterial Urease and its Role in Long-Lasting Human Diseases

    PubMed Central

    Konieczna, Iwona; Żarnowiec, Paulina; Kwinkowski, Marek; Kolesińska, Beata; Frączyk, Justyna; Kamiński, Zbigniew; Kaca, Wiesław

    2012-01-01

    Urease is a virulence factor found in various pathogenic bacteria. It is essential in colonization of a host organism and in maintenance of bacterial cells in tissues. Due to its enzymatic activity, urease has a toxic effect on human cells. The presence of ureolytic activity is an important marker of a number of bacterial infections. Urease is also an immunogenic protein and is recognized by antibodies present in human sera. The presence of such antibodies is connected with progress of several long-lasting diseases, like rheumatoid arthritis, atherosclerosis or urinary tract infections. In bacterial ureases, motives with a sequence and/or structure similar to human proteins may occur. This phenomenon, known as molecular mimicry, leads to the appearance of autoantibodies, which take part in host molecules destruction. Detection of antibodies-binding motives (epitopes) in bacterial proteins is a complex process. However, organic chemistry tools, such as synthetic peptide libraries, are helpful in both, epitope mapping as well as in serologic investigations. In this review, we present a synthetic report on a molecular organization of bacterial ureases - genetic as well as structural. We characterize methods used in detecting urease and ureolytic activity, including techniques applied in disease diagnostic processes and in chemical synthesis of urease epitopes. The review also provides a summary of knowledge about a toxic effect of bacterial ureases on human body and about occurrence of anti-urease antibodies in long-lasting diseases. PMID:23305365

  19. Prevention and treatment of bacterial diseases caused by bacterial bioterrorism threat agents.

    PubMed

    Greenfield, Ronald A; Bronze, Michael S

    2003-10-01

    There is general consensus that the bacterial agents or products most likely to be used as weapons of mass destruction are Bacillus anthracis, Yersinia pestis, Francisella tularensis and the neurotoxin of Clostridium botulinum. Modern supportive and antimicrobial therapy for inhalational anthrax is associated with a 45% mortality rate, reinforcing the need for better adjunctive therapy and prevention strategies. Pneumonic plague is highly contagious, difficult to recognize and is frequently fatal. Therefore, the development of vaccines against this agent is crucial. Although tularemia is associated with low mortality, the highly infectious nature of aerosolized F. tularensis poses a substantive threat that is best met by vaccine development. Safer antitoxins and a vaccine are required to meet the threat of the use of botulinum toxin as a weapon of mass destruction. In this article, the current status of research in these areas is reviewed. PMID:14554016

  20. Rainbow trout resistance to bacterial cold-water disease is moderately heritable and is not adversely correlated with growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to estimate the heritabilities for and genetic correlations among resistance to bacterial cold-water disease and growth traits in a population of rainbow trout. Bacterial cold-water disease, a chronic disease of rainbow trout, is caused by Flavobacterium psychrophilu...

  1. Role of Pore-Forming Toxins in Bacterial Infectious Diseases

    PubMed Central

    Los, Ferdinand C. O.; Randis, Tara M.

    2013-01-01

    SUMMARY Pore-forming toxins (PFTs) are the most common bacterial cytotoxic proteins and are required for virulence in a large number of important pathogens, including Streptococcus pneumoniae, group A and B streptococci, Staphylococcus aureus, Escherichia coli, and Mycobacterium tuberculosis. PFTs generally disrupt host cell membranes, but they can have additional effects independent of pore formation. Substantial effort has been devoted to understanding the molecular mechanisms underlying the functions of certain model PFTs. Likewise, specific host pathways mediating survival and immune responses in the face of toxin-mediated cellular damage have been delineated. However, less is known about the overall functions of PFTs during infection in vivo. This review focuses on common themes in the area of PFT biology, with an emphasis on studies addressing the roles of PFTs in in vivo and ex vivo models of colonization or infection. Common functions of PFTs include disruption of epithelial barrier function and evasion of host immune responses, which contribute to bacterial growth and spreading. The widespread nature of PFTs make this group of toxins an attractive target for the development of new virulence-targeted therapies that may have broad activity against human pathogens. PMID:23699254

  2. Association of Secondhand Smoke Exposure with Pediatric Invasive Bacterial Disease and Bacterial Carriage: A Systematic Review and Meta-analysis

    PubMed Central

    Lee, Chien-Chang; Middaugh, Nicole A.; Howie, Stephen R. C.; Ezzati, Majid

    2010-01-01

    Background A number of epidemiologic studies have observed an association between secondhand smoke (SHS) exposure and pediatric invasive bacterial disease (IBD) but the evidence has not been systematically reviewed. We carried out a systematic review and meta-analysis of SHS exposure and two outcomes, IBD and pharyngeal carriage of bacteria, for Neisseria meningitidis (N. meningitidis), Haemophilus influenzae type B (Hib), and Streptococcus pneumoniae (S. pneumoniae). Methods and Findings Two independent reviewers searched Medline, EMBASE, and selected other databases, and screened articles for inclusion and exclusion criteria. We identified 30 case-control studies on SHS and IBD, and 12 cross-sectional studies on SHS and bacterial carriage. Weighted summary odd ratios (ORs) were calculated for each outcome and for studies with specific design and quality characteristics. Tests for heterogeneity and publication bias were performed. Compared with those unexposed to SHS, summary OR for SHS exposure was 2.02 (95% confidence interval [CI] 1.52–2.69) for invasive meningococcal disease, 1.21 (95% CI 0.69–2.14) for invasive pneumococcal disease, and 1.22 (95% CI 0.93–1.62) for invasive Hib disease. For pharyngeal carriage, summary OR was 1.68 (95% CI, 1.19–2.36) for N. meningitidis, 1.66 (95% CI 1.33–2.07) for S. pneumoniae, and 0.96 (95% CI 0.48–1.95) for Hib. The association between SHS exposure and invasive meningococcal and Hib diseases was consistent regardless of outcome definitions, age groups, study designs, and publication year. The effect estimates were larger in studies among children younger than 6 years of age for all three IBDs, and in studies with the more rigorous laboratory-confirmed diagnosis for invasive meningococcal disease (summary OR 3.24; 95% CI 1.72–6.13). Conclusions When considered together with evidence from direct smoking and biological mechanisms, our systematic review and meta-analysis indicates that SHS exposure may be

  3. Overexpression of BSR1 confers broad-spectrum resistance against two bacterial diseases and two major fungal diseases in rice.

    PubMed

    Maeda, Satoru; Hayashi, Nagao; Sasaya, Takahide; Mori, Masaki

    2016-06-01

    Broad-spectrum disease resistance against two or more types of pathogen species is desirable for crop improvement. In rice, Xanthomonas oryzae pv. oryzae (Xoo), the causal bacteria of rice leaf blight, and Magnaporthe oryzae, the fungal pathogen causing rice blast, are two of the most devastating pathogens. We identified the rice BROAD-SPECTRUM RESISTANCE 1 (BSR1) gene for a BIK1-like receptor-like cytoplasmic kinase using the FOX hunting system, and demonstrated that BSR1-overexpressing (OX) rice showed strong resistance to the bacterial pathogen, Xoo and the fungal pathogen, M. oryzae. Here, we report that BSR1-OX rice showed extended resistance against two other different races of Xoo, and to at least one other race of M. oryzae. In addition, the rice showed resistance to another bacterial species, Burkholderia glumae, which causes bacterial seedling rot and bacterial grain rot, and to Cochliobolus miyabeanus, another fungal species causing brown spot. Furthermore, BSR1-OX rice showed slight resistance to rice stripe disease, a major viral disease caused by rice stripe virus. Thus, we demonstrated that BSR1-OX rice shows remarkable broad-spectrum resistance to at least two major bacterial species and two major fungal species, and slight resistance to one viral pathogen. PMID:27436950

  4. Overexpression of BSR1 confers broad-spectrum resistance against two bacterial diseases and two major fungal diseases in rice

    PubMed Central

    Maeda, Satoru; Hayashi, Nagao; Sasaya, Takahide; Mori, Masaki

    2016-01-01

    Broad-spectrum disease resistance against two or more types of pathogen species is desirable for crop improvement. In rice, Xanthomonas oryzae pv. oryzae (Xoo), the causal bacteria of rice leaf blight, and Magnaporthe oryzae, the fungal pathogen causing rice blast, are two of the most devastating pathogens. We identified the rice BROAD-SPECTRUM RESISTANCE 1 (BSR1) gene for a BIK1-like receptor-like cytoplasmic kinase using the FOX hunting system, and demonstrated that BSR1-overexpressing (OX) rice showed strong resistance to the bacterial pathogen, Xoo and the fungal pathogen, M. oryzae. Here, we report that BSR1-OX rice showed extended resistance against two other different races of Xoo, and to at least one other race of M. oryzae. In addition, the rice showed resistance to another bacterial species, Burkholderia glumae, which causes bacterial seedling rot and bacterial grain rot, and to Cochliobolus miyabeanus, another fungal species causing brown spot. Furthermore, BSR1-OX rice showed slight resistance to rice stripe disease, a major viral disease caused by rice stripe virus. Thus, we demonstrated that BSR1-OX rice shows remarkable broad-spectrum resistance to at least two major bacterial species and two major fungal species, and slight resistance to one viral pathogen. PMID:27436950

  5. Antimicrobial peptides as an opportunity against bacterial diseases.

    PubMed

    Galdiero, Stefania; Falanga, Annarita; Berisio, Rita; Grieco, Paolo; Morelli, Giancarlo; Galdiero, Massimiliano

    2015-01-01

    Antimicrobial peptides (AMPs) are an heterogeneous group of small amino acidic molecules produced by the innate immune system of a variety of organisms encompassing all orders of life from eukaryotes to amphibians, insects and plants. Numerous AMPs have been isolated from natural sources and many others have been de novo designed and synthetically produced. AMPs have antimicrobial activity in the micromolar range and compared with traditional antibiotics, they kill bacteria very rapidly. They act, principally, by the electrostatic attraction to negatively charged bacterial cells and consequently membrane disruption, but their antibacterial activity may also involve interference with metabolic processes or different cytoplasmic targets. AMPs are a group of unique and incredible compounds that may be directed to a therapeutic use either alone or in combination with existing antibiotics. PMID:25760092

  6. Jamming bacterial communication: New approaches for the treatment of infectious diseases

    PubMed Central

    Njoroge, Jacqueline; Sperandio, Vanessa

    2009-01-01

    The global rise of anti-microbial resistance, combined with the rapid rate of microbial evolution, and the slower development of novel antibiotics, underscores the urgent need for innovative therapeutics. We are facing a post-antibiotic era with a decreased armamentarium to combat infectious diseases. Development of novel drugs will rely on basic research aimed to increase our understanding of bacterial pathogenesis and the inter-cellular chemical signalling among bacterial cells. Such basic science, when combined with contemporary drug discovery technologies, may be translated into therapeutic applications to combat bacterial infections. In this review, we discuss many strategies aimed to interfere with bacterial cell-to-cell signalling via the quorum-sensing (QS) pathway to inhibit bacterial virulence and/or the development of microbial communities (known as biofilms), which are refractory to antibiotic treatment. QS antagonists should be viewed as blockers of pathogenicity rather than as anti-microbials and because QS is not involved in bacterial growth, inhibition of QS should not yield a strong selective pressure for development of resistance. QS inhibitors (QSIs) hold great expectations and we look forward to their application in fighting bacterial infections. PMID:20049722

  7. Bacterial Infections Following Splenectomy for Malignant and Nonmalignant Hematologic Diseases

    PubMed Central

    Leone, Giuseppe; Pizzigallo, Eligio

    2015-01-01

    Splenectomy, while often necessary in otherwise healthy patients after major trauma, finds its primary indication for patients with underlying malignant or nonmalignant hematologic diseases. Indications of splenectomy for hematologic diseases have been reducing in the last few years, due to improved diagnostic and therapeutic tools. In high-income countries, there is a clear decrease over calendar time in the incidence of all indication splenectomy except nonmalignant hematologic diseases. However, splenectomy, even if with different modalities including laparoscopic splenectomy and partial splenectomy, continue to be a current surgical practice both in nonmalignant hematologic diseases, such as Immune Thrombocytopenic Purpura (ITP), Autoimmune Hemolytic Anemia (AIHA), Congenital Hemolytic Anemia such as Spherocytosis, Sickle Cell Anemia and Thalassemia and Malignant Hematological Disease, such as lymphoma. Today millions of people in the world are splenectomized. Splenectomy, independently of its cause, induces an early and late increase in the incidence of venous thromboembolism and infections. Infections remain the most dangerous complication of splenectomy. After splenectomy, the levels of antibody are preserved but there is a loss of memory B cells against pneumococcus and tetanus, and the loss of marginal zone monocytes deputed to immunological defense from capsulated bacteria. Commonly, the infections strictly correlated to the absence of the spleen or a decreased or absent splenic function are due to encapsulated bacteria that are the most virulent pathogens in this set of patients. Vaccination with polysaccharide and conjugate vaccines again Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis should be performed before the splenectomy. This practice reduces but does not eliminate the occurrence of overwhelming infections due to capsulated bacteria. At present, most of infections found in splenectomized patients are due to Gram

  8. Viral and bacterial diseases in livestock in Mongolia.

    PubMed

    Odontsetseg, Namsraijav; Mweene, Aaron S; Kida, Hiroshi

    2005-02-01

    This review focuses on the status of infectious diseases that are serious for animal health and have adverse economic effects in Mongolia. Data presented here are limited due to the lack of published or other easily available documents. Foot-and-mouth disease continues to cause substantial economic losses as exemplified by the outbreak of infection with serotype O PanAsia lineage virus. In the case of the 2001 outbreak, a 65% reduction in export revenues was recorded. In order to ascertain the free status of Mongolia from rinderpest, sero-epidemiological surveillance has been carried out since 2001. In 2004, Mongolia was certified free from rinderpest by Office International des Epizooties (OIE). A sharp rise in both animal and human brucellosis incidence has become a serious problem. Rabies and anthrax remain endemic with occasional human cases. Other prevailing infectious diseases are contagious pustular dermatitis, contagious agalactia, enterotoxemia and pasteurellosis. The current programs for the control of infectious diseases in livestock in Mongolia lack a definite policy that would enable rapid implementation. A large-scale surveillance of infectious diseases in animals and management of appropriate preventive measures are urgently required in Mongolia. PMID:15822857

  9. [The role of chronic dental bacterial infections in the aetiopathogenesis of ischaemic heart disease].

    PubMed

    Stypułkowska, Jadwiga; Lyszczarz, Robert; Błazowska, Katarzyna

    2002-01-01

    Chronic dental infections, even of low intensity, may cause the development of atherosclerotic changes in arteries, that lead to coronary heart disease. There are many risk factors for atherosclerosis, but the most important are endothelium function disturbances, platelets activation and oxidative changes of plasmatic lipoproteins. Among factors that can induce the epithelium lesions bacterial factor may play an important role. In consequence of the bacterial cell breakdown place the release of endotoxins takes, that lead directly to the damage of endothelial cells. Apart from this direct effect endotoxins activate the fagocytes releasing superoxide reactive radicals, that cause lesions of endothelium. Probably the most widespread chronic bacterial infections in human are the diseases of periodontium and teeth and their inflammatory complications. Oral cavity is colonized by 300-400 bacterial species. In the case of dental bacterial infections bacteriemia occurs after such procedures as tooth extraction, endodontic treatment, therapeutic and hygienic interventions on periodontal tissues. The results of many investigations show the relationship between the oral status (dental and periodontal diseases as chronic oral infections) and disorders of cardiovascular system. PMID:17474623

  10. Integration of selective breeding and vaccination to improve disease resistance in aquaculture: Application to control bacterial cold water disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) is a frequent cause of elevated mortality in rainbow trout and the development of effective control strategies is a priority within the U.S. A goal of the NCCCWA breeding program is to produce germplasm with superior growth and survival following exposure to infe...

  11. A bacterial disease of yellow perch (Peres flavescens)

    USGS Publications Warehouse

    Ross, A.J.; Nordstrom, P.R.; Bailey, J.E.; Heaton, J.H.

    1960-01-01

    Examination of the freshly dead perch revealed the presence of multiple petechiae, which were visible externally as well as in the dorsal musculature. The peritoneal cavity showed evidence of inflammation and contained a bloody ascitic fluid. A number of the dead fish were placed on ice and shipped to the Western Fish Disease Laboratory in Seattle for bacteriological studies.

  12. Determination of bacterial disease map for rainbow trout farms in Van province

    NASA Astrophysics Data System (ADS)

    Arabaci, Muhammed; Önalan, Şükrü

    2016-04-01

    Lactococcosis, yersiniosis, listenollosis and cold water disease agents are frequently observed in Turkey as bacterial fish pathogens. Bacterial fish pathogens have high mortality prognosis, causing significant economic losses for the businesses. Use of molecular methods in substantiation of disease factors became prevalent in recent years. These methods have a significant role in fast diagnosis and early treatment of fish diseases. In the present study, 8 rainbow trout samples were obtained from each of 19 rainbow trout farms located in Van province, Turkey and registered with Food, Agriculture and Livestock Ministry. Total genomic DNAs were isolated from kidney tissues of sampled rainbow trout. Obtained DNAs were analyzed with real-time PCR there is/not (+/-) analysis using disease specific primer pairs for each disease. Molecular diagnosis of lactococcosis pathogen in 4 farms out of 19 rainbow trout farms active in Van province, and yersiniosis pathogen in 1 farm were made as a result real-time PCR analysis. Listenollosis and cold water pathogens were not molecularly observed. Results of the present study demonstrated that the region was safe for bacterial fish pathogens of cold water disease and listenollosis, which are observed frequently in Turkey, and there were deficiencies in preventive measures against lactococcosis and yersiniosis and fish transfer was a significant reason for the prevalence these diseases.

  13. Direct fluorescent antibody technique for the detection of bacterial kidney disease in paraffin-embedded tissues

    USGS Publications Warehouse

    Ochiai, T.; Yasutake, W.T.; Gould, R.W.

    1985-01-01

    The direct fluorescent antibody technique (FAT) was successfully used to detect the causative agent of bacterial kidney disease (BKD), Renibacterium salmoninarum, in Bouin's solution flexed and paraffinembedded egg and tissue sections. This method is superior to gram stain and may be particularly useful in detecting the BKD organism in fish with low-grade infection.

  14. Preliminary field evaluation of rainbow trout selectively bred for increased resistance to bacterial cold water disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) is one of the most frequent causes of elevated mortality in juvenile salmonids, and the development of effective control strategies is a priority. We previously reported results of a selective breeding program designed to increase rainbow trout survival following ...

  15. Field evaluation of rainbow trout selectively bred for resistance to bacterial cold water disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) is a frequent cause of elevated mortality in rainbow trout and the development of effective control strategies is a priority within the U.S. Since 2005, the NCCCWA has implemented a selective breeding program designed to increase survival following BCWD exposure....

  16. EFFECTS OF PHOSGENE EXPOSURE ON BACTERIAL VIRAL AND NEOPLASTIC LUNG DISEASE SUSCEPTIBILITY IN MICE

    EPA Science Inventory

    The effects of phosgene inhalation exposure on host resistance models representative of bacterial, viral, and neoplastic lung diseases were assessed. ingle 4 h exposure to concentrations of phosgene of 0.025 ppm and above significantly enhanced mortality due to aerosol infection ...

  17. Cuticles of European and American lobsters harbor diverse bacterial species and differ in disease susceptibility

    PubMed Central

    Whitten, Miranda M A; Davies, Charlotte E; Kim, Anita; Tlusty, Michael; Wootton, Emma C; Chistoserdov, Andrei; Rowley, Andrew F

    2014-01-01

    Diseases of lobster shells have a significant impact on fishing industries but the risk of disease transmission between different lobster species has yet to be properly investigated. This study compared bacterial biofilm communities from American (Homarus americanus) and European lobsters (H. gammarus), to assess both healthy cuticle and diseased cuticle during lesion formation. Culture-independent molecular techniques revealed diversity in the bacterial communities of cuticle biofilms both within and between the two lobster species, and identified three bacterial genera associated with shell lesions plus two putative beneficial bacterial species (detected exclusively in healthy cuticle or healing damaged cuticle). In an experimental aquarium shared between American and European lobsters, heterospecific transmission of potentially pathogenic bacteria appeared to be very limited; however, the claws of European lobsters were more likely to develop lesions when reared in the presence of American lobsters. Aquarium biofilms were also examined but revealed no candidate pathogens for environmental transmission. Aquimarina sp. ‘homaria’ (a potential pathogen associated with a severe epizootic form of shell disease) was detected at a much higher prevalence among American than European lobsters, but its presence correlated more with exacerbation of existing lesions rather than with lesion initiation. PMID:24817518

  18. Recent Trends in Control Methods for Bacterial Wilt Diseases Caused by Ralstonia solanacearum

    PubMed Central

    Yuliar; Nion, Yanetri Asi; Toyota, Koki

    2015-01-01

    Previous studies have described the development of control methods against bacterial wilt diseases caused by Ralstonia solanacearum. This review focused on recent advances in control measures, such as biological, physical, chemical, cultural, and integral measures, as well as biocontrol efficacy and suppression mechanisms. Biological control agents (BCAs) have been dominated by bacteria (90%) and fungi (10%). Avirulent strains of R. solanacearum, Pseudomonas spp., Bacillus spp., and Streptomyces spp. are well-known BCAs. New or uncommon BCAs have also been identified such as Acinetobacter sp., Burkholderia sp., and Paenibacillus sp. Inoculation methods for BCAs affect biocontrol efficacy, such as pouring or drenching soil, dipping of roots, and seed coatings. The amendment of different organic matter, such as plant residue, animal waste, and simple organic compounds, have frequently been reported to suppress bacterial wilt diseases. The combined application of BCAs and their substrates was shown to more effectively suppress bacterial wilt in the tomato. Suppression mechanisms are typically attributed to the antibacterial metabolites produced by BCAs or those present in natural products; however, the number of studies related to host resistance to the pathogen is increasing. Enhanced/modified soil microbial communities are also indirectly involved in disease suppression. New promising types of control measures include biological soil disinfection using substrates that release volatile compounds. This review described recent advances in different control measures. We focused on the importance of integrated pest management (IPM) for bacterial wilt diseases. PMID:25762345

  19. Inconsequential effect of nutritional treatments on Huanglongbing control, fruit quality, bacterial titer and disease progress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of an enhanced nutritional programs (ENPs) to minimize the deleterious effects of the vector transmitted bacterial disease, citrus huanglongbing (HLB) caused by Candidatus Liberibacter asiaticus (Las), has been a topic of considerable discussion and debate since the discovery of HLB in Flori...

  20. Mapping of QTL for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonids aquaculture. We previously detected genetic variation in survival following challenge with Flavobacterium psychrophilum (Fp), the causative agent of BCWD in rainbow trout, and a family-based selection program to impro...

  1. Field evaluation of rainbow trout selectively bred for resistance to bacterial cold water disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) is a frequent cause of elevated mortality in rainbow trout and the development of effective control strategies is a priority within the U.S. Since 2005, the NCCCWA has implemented a selective breeding program and has created three genetic lines of outbred rainbow...

  2. Mapping of QTL for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation in survival following challenge with Flavobacterium psychrophilum, the causative agent of BCWD in rainbow trout, and a family-based selection program to improve res...

  3. Mapping of QTL for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation in survival following challenge with Flavobacterium psychrophilum (Fp), the causative agent of BCWD in rainbow trout, and a family-based selection program to improv...

  4. Potato psyllids and their bacterial allies: Two fronts in the war against zebra chip disease.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato psyllid is a major pest of potato in the western United States that transmits the pathogen that causes zebra chip disease. Potato psyllids, like all psyllids, have close associations with bacterial endosymbionts living within them. These endosymbionts may be obligate or facultative, and the...

  5. Response to selection for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies indicate that resistance to experimental bacterial cold water disease (BCWD) challenge is heritable and thus may be improved through selective breeding. Our objective was to estimate response after one generation of genetic selection for resistance to BCWD in a pedigreed population ...

  6. Response to selection for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A family-based selection program was initiated at the National Center for Cool and Cold Water Aquaculture in 2005 to improve resistance to bacterial cold water disease (BCWD) in rainbow trout. The objective of this study was to estimate response to 2 generations of selection. A total of 14,841 juven...

  7. Future impact of molecular biology and biotechnology on bacterial and viral diseases.

    PubMed

    Pang, T

    1993-06-01

    The advent of recombinant DNA technology has already made a significant impact on various aspects related to the basic understanding of pathogenic mechanisms in infectious diseases, as well as practical applications related to diagnostics and prevention. The present paper discusses recent technological innovations and increased analytical capabilities which promise to have an even more significant impact on the control of viral and bacterial diseases. PMID:8350782

  8. New Paenibacillus larvae bacterial isolates from honey bee colonies infected with American foulbrood disease in Egypt

    PubMed Central

    Masry, Saad Hamdy Daif; Kabeil, Sanaa Soliman; Hafez, Elsayed Elsayed

    2014-01-01

    The American foulbrood disease is widely distributed all over the world and causes a serious problem for the honeybee industry. Different infected larvae were collected from different apiaries, ground in phosphate saline buffer (PSB) and bacterial isolation was carried out on nutrient agar medium. Different colonies were observed and were characterized biologically. Two bacterial isolates (SH11 and SH33) were subjected to molecular identification using 16S rRNA gene and the sequence analysis revealed that the two isolates are Paenibacillus larvae with identity not exceeding 83%. The DNA sequence alignment between the other P. larvae bacterial strains and the two identified bacterial isolates showed that all the examined bacterial strains have the same ancestor, i.e. they have the same origin. The SH33 isolate was closely related to the P. larvae isolated from Germany, whereas the isolate SH11 was close to the P. larvae isolated from India. The phylogenetic tree constructed for 20 different Bacillus sp. and the two isolates SH11 and SH33 demonstrated that the two isolates are Bacillus sp. and they are new isolates. The bacterial isolates will be subjected to more tests for more confirmations. PMID:26740757

  9. Ultrastructural observations on bacterial invasion in cementum and radicular dentin of periodontally diseased human teeth.

    PubMed

    Adriaens, P A; Edwards, C A; De Boever, J A; Loesche, W J

    1988-08-01

    In this study the bacterial invasion in root cementum and radicular dentin of periodontally diseased, caries-free human teeth was examined. In addition, structural changes in these tissues, which could be related to the bacterial invasion, were reported. Twenty-one caries-free human teeth with extensive periodontal attachment loss were studied by light and scanning electron microscopy. At the base of the gingival pocket, bacteria were found in the spaces between remnants of Sharpey's fibers and their point of insertion in the cementum. In teeth that had been scaled and root planed, most of the root cementum had been removed. Bacterial invasion was found in the remaining root cementum. The invasion seemed to start as a localized process, often involving only one bacterium. In other areas bacteria were present in lacunar defects in the cementum. These lacunae extended into the radicular dentin. In 11 teeth bacteria had invaded the dentinal tubules. Most bacteria were located in the outer 300 microns of the dentinal tubules, although occasionally they were found in deeper parts. In two of the nontreated teeth, bacteria were detected on the pulpal wall. No correlation was found between the presence of bacterial invasion and the absence of radicular cementum. No bacteria were found in the portion of the root located apically to the epithelial attachment. These data are in agreement with our results from cultural studies of the bacterial flora in these structures. It was also demonstrated that in spite of meticulous scaling and root planning and personal oral hygiene, bacterial plaque remained present on radicular surfaces. Both the invaded dentinal tubules and the lacunae could act as bacterial reservoirs from which recolonization of treated root surfaces occurs. From these reservoirs bacteria could also induce pulpal pathoses. Since these bacterial reservoirs are not eliminated by conventional mechanical periodontal treatment, it seems appropriate to combine mechanical

  10. Importance of Candida-bacterial polymicrobial biofilms in disease

    PubMed Central

    Harriott, Melphine M.; Noverr, Mairi C.

    2011-01-01

    Candida albicans is the most prevalent human fungal pathogen, with an ability to inhabit diverse host niches and cause disease in both immunocompetent and immunocompromised individuals. C. albicans also readily forms biofilms on indwelling medical devices and mucosal tissues, which serve as an infectious reservoir that is difficult to eradicate, and can lead to lethal systemic infections. Biofilm formation occurs within a complex milieu of host factors and other members of the human microbiota. Polymicrobial interactions will likely dictate the cellular and biochemical composition of the biofilm, as well as influence clinically relevant outcomes such as drug and host resistance and virulence. In this manuscript, we review C. albicans infections in the context of in vivo polymicrobial biofilms and implications for pathogenesis. PMID:21855346

  11. Inflammatory bowel disease in rats: Bacterial and chemical interaction

    PubMed Central

    Hussein, Inaya Abdallah Hajj; Tohme, Rania; Barada, Kassem; Mostafa, Mostafa Hassan; Freund, Jean-Noel; Jurjus, Rosalyn A; Karam, Walid; Jurjus, Abdo

    2008-01-01

    AIM: To develop a novel model of colitis in rats, using a combination of iodoacetamide and enteropathogenic E. coli (EPEC), and to elucidate the pathophysiologic processes implicated in the development of ulcerative colitis (UC). METHODS: Male Sprague-Dawley rats (n = 158) were inoculated intrarectally on a weekly basis with 4 different combinations: (a) 1% methylcellulose (MC), (b) 100 μL of 6% iodoacetamide (IA) in 1% MC, (c) 200 μL containing 4 × 108 colony factor units (CFU) of EPEC, and (d) combined treatment of (IA) followed by bacteria (B) after 2 d. Thirty days post treatment, each of the four groups was divided into two subgroups; the inoculation was stopped for one subgroup and the other subgroup continued with biweekly inoculation until the end of the experiment. Colitis was evaluated by the clinical course of the disease, the macroscopic and microscopic alterations, activity of myeloperoxidase (MPO), and by TNF-α gene expression. RESULTS: Findings indicative of UC were seen in the combined treatment (IA + B) as well as the IA continued treatment groups: the animals showed slow rate of increase in body weight, diarrhea, bloody stools, high colonic ulcer score, as well as histological alterations characteristic of UC, with an extensive inflammatory reaction. During the course of the experiment, the MPO activity was consistently elevated and the TNF-α gene expression was upregulated compared to the control animals. CONCLUSION: The experimental ulcerative colitis model used in the present study resembles, to a great extent, the human disease. It is reproducible with characteristics indicative of chronicity. PMID:18609687

  12. Southern leaf blight disease severity is correlated with decreased maize leaf epiphytic bacterial species richness and the phyllosphere bacterial diversity decline is enhanced by nitrogen fertilization

    PubMed Central

    Manching, Heather C.; Balint-Kurti, Peter J.; Stapleton, Ann E.

    2014-01-01

    Plant leaves are inhabited by a diverse group of microorganisms that are important contributors to optimal growth. Biotic and abiotic effects on plant growth are usually studied in controlled settings examining response to variation in single factors and in field settings with large numbers of variables. Multi-factor experiments with combinations of stresses bridge this gap, increasing our understanding of the genotype-environment-phenotype functional map for the host plant and the affiliated epiphytic community. The maize inbred B73 was exposed to single and combination abiotic and the biotic stress treatments: low nitrogen fertilizer and high levels of infection with southern leaf blight (causal agent Cochliobolus heterostrophus). Microbial epiphyte samples were collected at the vegetative early-season phase and species composition was determined using 16S ribosomal intergenic spacer analysis. Plant traits and level of southern leaf blight disease were measured late-season. Bacterial diversity was different among stress treatment groups (P < 0.001). Lower species richness—alpha diversity—was correlated with increased severity of southern leaf blight disease when disease pressure was high. Nitrogen fertilization intensified the decline in bacterial alpha diversity. While no single bacterial ribotype was consistently associated with disease severity, small sets of ribotypes were good predictors of disease levels. Difference in leaf bacterial-epiphyte diversity early in the season were correlated with plant disease severity, supporting further tests of microbial epiphyte-disease correlations for use in predicting disease progression. PMID:25177328

  13. Efficacy of cellular vaccines and genetic adjuvants against bacterial kidney disease in chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    Rhodes, Linda D; Rathbone, Cindra K; Corbett, Stephen C; Harrell, Lee W; Strom, Mark S

    2004-04-01

    DNA adjuvants and whole bacterial cell vaccines against bacterial kidney disease (BKD) were tested in juvenile chinook salmon. Whole cell vaccines of either a nonpathogenic Arthrobacter spp. or an attenuated Renibacterium salmoninarum strain provided limited prophylactic protection against acute intraperitoneal challenge with virulent R. salmoninarum, and the addition of either synthetic oligodeoxynucleotides or purified R. salmoninarum genomic DNA as adjuvants did not increase protection. However, a combination of both whole cell vaccines significantly increased survival among fish naturally infected with R. salmoninarum, and the surviving fish treated with the combination vaccine exhibited reduced levels of bacterial antigens in the kidney. This is the first demonstration of a potential therapeutic effect of a whole cell vaccine against BKD. PMID:15123289

  14. Cystic Fibrosis Pigs Develop Lung Disease and Exhibit Defective Bacterial Eradication at Birth

    PubMed Central

    Stoltz, David A; Meyerholz, David K; Pezzulo, Alejandro A; Ramachandran, Shyam; Rogan, Mark P; Davis, Greg J; Hanfland, Robert A; Wohlford-Lenane, Chris; Dohrn, Cassie L; Bartlett, Jennifer A; Nelson, George A; Chang, Eugene H; Taft, Peter J; Ludwig, Paula S; Estin, Mira; Hornick, Emma E; Launspach, Janice L; Samuel, Melissa; Rokhlina, Tatiana; Karp, Philip H; Ostedgaard, Lynda S; Uc, Aliye; Starner, Timothy D; Horswill, Alexander R; Brogden, Kim A; Prather, Randall S; Richter, Sandra S; Shilyansky, Joel; McCray, Paul B; Zabner, Joseph; Welsh, Michael J

    2010-01-01

    Lung disease causes most of the morbidity and mortality in cystic fibrosis (CF). However, understanding its pathogenesis has been hindered by lack of an animal model with characteristic features of CF. To overcome this problem, we recently generated pigs with targeted CFTR genes. We now report that, within months of birth, CF pigs spontaneously develop hallmark features of CF lung disease including airway inflammation, remodeling, mucus accumulation, and infection. Their lungs contained multiple bacterial species, suggesting an equal opportunity host defense defect. In humans, the temporal and causal relationships between inflammation and infection have remained uncertain. To investigate these processes, we studied newborn pigs. Their lungs showed no inflammation, but were less often sterile than controls. Moreover, after intrapulmonary bacterial challenge, CF pigs failed to eradicate bacteria as effectively as wild-type pigs. These results suggest that impaired bacterial elimination is the pathogenic event that initiates a cascade of inflammation and pathology in CF lungs. Finding that CF pigs have a bacterial host defense defect within hours of birth provides an opportunity to further investigate pathogenesis and to test therapeutic and preventive strategies before secondary consequences develop. PMID:20427821

  15. Bacterial Infection in Chronic Obstructive Pulmonary Disease in 2000: a State-of-the-Art Review

    PubMed Central

    Sethi, Sanjay; Murphy, Timothy F.

    2001-01-01

    Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States. The precise role of bacterial infection in the course and pathogenesis of COPD has been a source of controversy for decades. Chronic bacterial colonization of the lower airways contributes to airway inflammation; more research is needed to test the hypothesis that this bacterial colonization accelerates the progressive decline in lung function seen in COPD (the vicious circle hypothesis). The course of COPD is characterized by intermittent exacerbations of the disease. Studies of samples obtained by bronchoscopy with the protected specimen brush, analysis of the human immune response with appropriate immunoassays, and antibiotic trials reveal that approximately half of exacerbations are caused by bacteria. Nontypeable Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae are the most common causes of exacerbations, while Chlamydia pneumoniae causes a small proportion. The role of Haemophilus parainfluenzae and gram-negative bacilli remains to be established. Recent progress in studies of the molecular mechanisms of pathogenesis of infection in the human respiratory tract and in vaccine development guided by such studies promises to lead to novel ways to treat and prevent bacterial infections in COPD. PMID:11292642

  16. Bacterial community composition of chronic periodontitis and novel oral sampling sites for detecting disease indicators

    PubMed Central

    2014-01-01

    Background Periodontitis is an infectious and inflammatory disease of polymicrobial etiology that can lead to the destruction of bones and tissues that support the teeth. The management of chronic periodontitis (CP) relies heavily on elimination or at least control of known pathogenic consortia associated with the disease. Until now, microbial plaque obtained from the subgingival (SubG) sites has been the primary focus for bacterial community analysis using deep sequencing. In addition to the use of SubG plaque, here, we investigated whether plaque obtained from supragingival (SupG) and tongue dorsum sites can serve as alternatives for monitoring CP-associated bacterial biomarkers. Results Using SubG, SupG, and tongue plaque DNA from 11 healthy and 13 diseased subjects, we sequenced V3 regions (approximately 200 bases) of the 16S rRNA gene using Illumina sequencing. After quality filtering, approximately 4.1 million sequences were collapsed into operational taxonomic units (OTUs; sequence identity cutoff of >97%) that were classified to a total of 19 phyla spanning 114 genera. Bacterial community diversity and overall composition was not affected by health or disease, and multiresponse permutation procedure (MRPP) on Bray-Curtis distance measures only supported weakly distinct bacterial communities in SubG and tongue plaque depending on health or disease status (P < 0.05). Nonetheless, in SubG and tongue sites, the relative abundance of Firmicutes was increased significantly from health to disease and members of Synergistetes were found in higher abundance across all sites in disease. Taxa indicative of CP were identified in all three locations (for example, Treponema denticola, Porphyromonas gingivalis, Synergistes oral taxa 362 and 363). Conclusions For the first time, this study demonstrates that SupG and tongue dorsum plaque can serve as alternative sources for detecting and enumerating known and novel bacterial biomarkers of CP. This finding is clinically

  17. Transcriptome analysis of Fusarium virguliforme provides additional evidence of toxins that contribute to foliar symptoms of soybean sudden death syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxins produced by the soil-borne fungus, Fusarium virguliforme, cause foliar symptoms in soybean. The disease in soybean is referred to as soybean sudden death syndrome (SDS). Three toxins produced by the fungus were reported to be associated with SDS foliar symptoms, but none produced identical S...

  18. Mechanisms linking bacterial infections of the bovine endometrium to disease and infertility.

    PubMed

    Carneiro, Luísa Cunha; Cronin, James Graham; Sheldon, Iain Martin

    2016-03-01

    Bacterial infections of the endometrium after parturition commonly cause metritis and endometritis in dairy cattle, and these diseases are important because they compromise animal welfare and incur economic costs, as well as delaying or preventing conception. Here we highlight that uterine infections cause infertility, discuss which bacteria cause uterine disease, and review the evidence for mechanisms of inflammation and tissue damage in the endometrium. Bacteria cultured from the uterus of diseased animals include Escherichia coli, Trueperella pyogenes, and several anaerobic species, but their causative role in disease is challenged by the discovery of many other bacteria in the uterine disease microbiome. Irrespective of the species of bacteria, endometrial cell inflammatory responses to infection initially depend on innate immunity, with Toll-like receptors binding pathogen-associated molecular patterns, such as lipopolysaccharide and bacterial lipopeptides. In addition to tissue damage associated with parturition and inflammation, endometrial cell death is caused by a cholesterol-dependent cytolysin secreted by T. pyogenes, called pyolysin, which forms pores in plasma membranes of endometrial cells. However, endometrial cells surprisingly do not sense damage-associated molecular patterns, but a combination of infections followed by cell damage leads to release of the intracellular cytokine interleukin (IL)-1 alpha from endometrial cells, which then acts to scale inflammatory responses. To develop strategies to limit the impact of uterine disease on fertility, future work should focus on determining which bacteria and virulence factors cause endometritis, and understanding how the host response to infection is regulated in the endometrium. PMID:26952747

  19. Overexpression of polyphenol oxidase in transgenic tomato plants results in enhanced bacterial disease resistance.

    PubMed

    Li, Li; Steffens, John C

    2002-06-01

    Polyphenol oxidases (PPOs; EC 1.10.3.2 or EC 1.14.18.1) catalyzing the oxygen-dependent oxidation of phenols to quinones are ubiquitous among angiosperms and assumed to be involved in plant defense against pests and pathogens. In order to investigate the role of PPO in plant disease resistance, we made transgenic tomato ( Lycopersicon esculentum Mill. cv. Money Maker) plants that overexpressed a potato ( Solanum tuberosum L.) PPO cDNA under control of the cauliflower mosaic virus 35S promoter. The transgenic plants expressed up to 30-fold increases in PPO transcripts and 5- to 10-fold increases in PPO activity and immunodetectable PPO. As expected, these PPO-overexpressing transgenic plants oxidized the endogenous phenolic substrate pool at a higher rate than control plants. Three independent transgenic lines were selected to assess their interaction with the bacterial pathogen Pseudomonas syringae pv. tomato. The PPO-overexpressing tomato plants exhibited a great increase in resistance to P. syringae. Compared with control plants, these transgenic lines showed less severity of disease symptoms, with over 15-fold fewer lesions, and strong inhibition of bacterial growth, with over 100-fold reduction of bacterial population in the infected leaves. These results demonstrate the importance of PPO-mediated phenolic oxidation in restricting plant disease development. PMID:12029473

  20. Isolation and Characterization of Bacteriophages Against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit.

    PubMed

    Yu, Ji-Gang; Lim, Jeong-A; Song, Yu-Rim; Heu, Sunggi; Kim, Gyoung Hee; Koh, Young Jin; Oh, Chang-Sik

    2016-02-01

    Pseudomonas syringae pv. actinidiae causes bacterial canker disease in kiwifruit. Owing to the prohibition of agricultural antibiotic use in major kiwifruit-cultivating countries, alternative methods need to be developed to manage this disease. Bacteriophages are viruses that specifically infect target bacteria and have recently been reconsidered as potential biological control agents for bacterial pathogens owing to their specificity in terms of host range. In this study, we isolated bacteriophages against P. syringae pv. actinidiae from soils collected from kiwifruit orchards in Korea and selected seven bacteriophages for further characterization based on restriction enzyme digestion patterns of genomic DNA. Among the studied bacteriophages, two belong to the Myoviridae family and three belong to the Podoviridae family, based on morphology observed by transmission electron microscopy. The host range of the selected bacteriophages was confirmed using 18 strains of P. syringae pv. actinidiae, including the Psa2 and Psa3 groups, and some were also effective against other P. syringae pathovars. Lytic activity of the selected bacteriophages was sustained in vitro until 80 h, and their activity remained stable up to 50°C, at pH 11, and under UV-B light. These results indicate that the isolated bacteriophages are specific to P. syringae species and are resistant to various environmental factors, implying their potential use in control of bacterial canker disease in kiwifruits. PMID:26628254

  1. Reduction of rainbow trout spleen size by splenectomy does not alter resistance against bacterial cold water disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In lower vertebrates, the contribution of the spleen to anti-bacterial immunity is poorly understood. Researchers have previously reported a phenotypic and genetic correlation between resistance to Flavobacterium psychrophilum, the causative agent of bacterial cold water disease (BCWD) and spleen so...

  2. Fibronectin Binding Protein BBK32 of the Lyme Disease Spirochete Promotes Bacterial Attachment to Glycosaminoglycans

    PubMed Central

    Fischer, Joshua R.; LeBlanc, Kimberly T.; Leong, John M.

    2006-01-01

    Borrelia burgdorferi, the agent of Lyme disease, causes a multisystemic illness that can affect the skin, heart, joints, and nervous system and is capable of attachment to diverse cell types. Among the host components recognized by this spirochete are fibronectin and glycosaminoglycans (GAGs). Three surface-localized GAG-binding bacterial ligands, Bgp, DbpA, and DbpB, have been previously identified, but recent studies suggested that at least one additional GAG-binding ligand is expressed on the spirochetal surface when the spirochete is adapted to the mammalian host environment. BBK32 is a surface lipoprotein that is produced during infection and that has been shown to bind to fibronectin. In this study, we show that, when BBK32 was produced from a shuttle vector in an otherwise nonadherent high-passage B. burgdorferi strain, the protein localized on the bacterial surface and conferred attachment to fibronectin and to mammalian cell monolayers. In addition, the high-passage strain producing BBK32 bound to purified preparations of the GAGs dermatan sulfate and heparin, as well as to these GAGs on the surfaces of cultured mammalian cells. Recombinant BBK32 recognized purified heparin, indicating that the bacterial attachment to GAGs was due to direct binding by BBK32. This GAG-binding activity of BBK32 is apparently independent of fibronectin recognition, because exogenous heparin had no effect on BBK32-mediated bacterial binding to fibronectin. PMID:16368999

  3. Cultivation-Independent Methods Reveal Differences among Bacterial Gut Microbiota in Triatomine Vectors of Chagas Disease

    PubMed Central

    da Mota, Fabio Faria; Marinho, Lourena Pinheiro; Moreira, Carlos José de Carvalho; Lima, Marli Maria; Mello, Cícero Brasileiro; Garcia, Eloi Souza; Carels, Nicolas; Azambuja, Patricia

    2012-01-01

    Background Chagas disease is a trypanosomiasis whose agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous bugs known as triatomines. Even though insecticide treatments allow effective control of these bugs in most Latin American countries where Chagas disease is endemic, the disease still affects a large proportion of the population of South America. The features of the disease in humans have been extensively studied, and the genome of the parasite has been sequenced, but no effective drug is yet available to treat Chagas disease. The digestive tract of the insect vectors in which T. cruzi develops has been much less well investigated than blood from its human hosts and constitutes a dynamic environment with very different conditions. Thus, we investigated the composition of the predominant bacterial species of the microbiota in insect vectors from Rhodnius, Triatoma, Panstrongylus and Dipetalogaster genera. Methodology/Principal Findings Microbiota of triatomine guts were investigated using cultivation-independent methods, i.e., phylogenetic analysis of 16s rDNA using denaturing gradient gel electrophoresis (DGGE) and cloned-based sequencing. The Chao index showed that the diversity of bacterial species in triatomine guts is low, comprising fewer than 20 predominant species, and that these species vary between insect species. The analyses showed that Serratia predominates in Rhodnius, Arsenophonus predominates in Triatoma and Panstrongylus, while Candidatus Rohrkolberia predominates in Dipetalogaster. Conclusions/Significance The microbiota of triatomine guts represents one of the factors that may interfere with T. cruzi transmission and virulence in humans. The knowledge of its composition according to insect species is important for designing measures of biological control for T. cruzi. We found that the predominant species of the bacterial microbiota in triatomines form a group of low complexity whose structure

  4. Clinical Implications of Oral Candidiasis: Host Tissue Damage and Disseminated Bacterial Disease

    PubMed Central

    Kong, Eric F.; Kucharíková, Sona; Peters, Brian M.; Shirtliff, Mark E.

    2014-01-01

    The clinical significance of polymicrobial interactions, particularly those between commensal species with high pathogenic potential, remains largely understudied. Although the dimorphic fungal species Candida albicans and the bacterium Staphylococcus aureus are common cocolonizers of humans, they are considered leading opportunistic pathogens. Oral candidiasis specifically, characterized by hyphal invasion of oral mucosal tissue, is the most common opportunistic infection in HIV+ and immunocompromised individuals. In this study, building on our previous findings, a mouse model was developed to investigate whether the onset of oral candidiasis predisposes the host to secondary staphylococcal infection. The findings demonstrated that in mice with oral candidiasis, subsequent exposure to S. aureus resulted in systemic bacterial infection with high morbidity and mortality. Histopathology and scanning electron microscopy of tongue tissue from moribund animals revealed massive C. albicans hyphal invasion coupled with S. aureus deep tissue infiltration. The crucial role of hyphae in the process was demonstrated using a non-hypha-producing and a noninvasive hypha-producing mutant strains of C. albicans. Further, in contrast to previous findings, S. aureus dissemination was aided but not contingent upon the presence of the Als3p hypha-specific adhesion. Importantly, impeding development of mucosal C. albicans infection by administering antifungal fluconazole therapy protected the animals from systemic bacterial disease. The combined findings from this study demonstrate that oral candidiasis may constitute a risk factor for disseminated bacterial disease warranting awareness in terms of therapeutic management of immunocompromised individuals. PMID:25422264

  5. Bacterial Infection of endometrial stromal cells influences bovine herpersvirus 4 immediate early gene activation: a new insight into bacterial and viral interaction for uterine disease

    PubMed Central

    Donofrio, Gaetano; Ravanetti, Lara; Cavirani, Sandro; Herath, Shan; Capocefalo, Antonio; Sheldon, Iain Martin

    2009-01-01

    Experimental infection with the gammaherpesvirus Bovine herpesvirus 4 (BoHV-4) rarely establishes disease, yet BoHV-4 is commonly associated with uterine disease in cattle. Uterine disease involves co-infection with bacteria such as Escherichia coli, which stimulate the production of prostaglandin E2 (PGE2) by endometrial cells. BoHV-4 replication depends on Immediate Early 2 (IE2) gene transactivation, and in the present study, PGE2, E. coli or its lipopolysaccharide (LPS), up-regulated the IE2 gene promoter in uterine cells. Bacterial co-infection is important for BoHV-4 uterine disease. PMID:18577555

  6. Docosahexaenoic Acid, Inflammation, and Bacterial Dysbiosis in Relation to Periodontal Disease, Inflammatory Bowel Disease, and the Metabolic Syndrome

    PubMed Central

    Tabbaa, Maria; Golubic, Mladen; Roizen, Michael F.; Bernstein, Adam M.

    2013-01-01

    Docosahexaenoic acid (DHA), a long-chain omega-3 polyunsaturated fatty acid, has been used to treat a range of different conditions, including periodontal disease (PD) and inflammatory bowel disease (IBD). That DHA helps with these oral and gastrointestinal diseases in which inflammation and bacterial dysbiosis play key roles, raises the question of whether DHA may assist in the prevention or treatment of other inflammatory conditions, such as the metabolic syndrome, which have also been linked with inflammation and alterations in normal host microbial populations. Here we review established and investigated associations between DHA, PD, and IBD. We conclude that by beneficially altering cytokine production and macrophage recruitment, the composition of intestinal microbiota and intestinal integrity, lipopolysaccharide- and adipose-induced inflammation, and insulin signaling, DHA may be a key tool in the prevention of metabolic syndrome. PMID:23966110

  7. Caroli's disease and congenital hepatic fibrosis associated with polycystic kidney disease. A case presenting with acute focal bacterial nephritis.

    PubMed

    Sung, J M; Huang, J J; Lin, X Z; Ruaan, M K; Lin, C Y; Chang, T T; Shu, H F; Chow, N H

    1992-12-01

    Congenital cystic dilatation of the intrahepatic biliary ducts (Caroli's disease), until recently, has been infrequently recognized. It is often associated with autosomal recessive polycystic kidney disease (ARPKD) and congenital hepatic fibrosis (CHF). We hereby report a case with Caroli's disease, polycystic kidney disease (PKD), and CHF: This 24-year-old female patient initially presented with acute bacterial nephritis (ABN). Renal ultrasonography revealed bilateral enlarged kidneys with multiple cysts. Because her parents showed no renal cyst on ultrasonographic examination, she received further studies. Abdominal ultrasonography showed cystic dilatation of the biliary tree. Computed tomography (CT) with meglumine lotroxinate (biliscopin) infusion study and hepatobiliary scintigraphy confirmed the diagnosis of Caroli's disease. Liver biopsy revealed CHF: The radiographic and scintigraphic pictures are hereby illustrated and CT with biliscopin infusion study is emphasized. We conclude that if radiologic evidence of renal cystic lesions is absent in the parents of patients with PKD, the coexistence of Caroli's disease and CHF should be considered. The clinical pictures of ABN in this patient are also discussed. As far as we know, this is the first reported case of ABN in a patient with PKD and Caroli's disease, and it showed good response to antibiotic therapy. PMID:1468163

  8. Developments in the control of bacterial kidney disease of salmonid fishes

    USGS Publications Warehouse

    Elliott, D.G.; Pascho, R.J.; Bullock, G.L.

    1989-01-01

    Bacterial kidney disease of salmonid fishes, caused by Renibactenum salrnoninarum, was first reported more than 50 yr ago; nevertheless, large gaps persist in our knowledge of the infection - particularly in methods for its control. In the 1950's, principal control measures consisted of prophylactic or therapeutic feeding of sulfonamides, which were later supplanted by the antibiotic erythromycin. Chemotherapy has effected some reduction of mortality, but benefits are typically transient and mortality usually resumes after the drug is withdrawn. Some studies have indicated that diet composition affects the prevalence and severity of the disease. Although tests of chemotherapeutants and diet modification have continued, research emphasis has shifted partly toward prevention of the disease by breaking the infection cycle. It is now generally accepted that R. salrnoninarum can be transmitted both vertically and horizontally. Experimental evidence indicates that immersion of newly fertilized eggs in iodophor or erythromycin does not prevent vertical transmission. However, the injection of female salmon with erythromycin before they spawn shows promise as a practical means of interrupting vertical transmission. The results of attempts to prevent infection of juvenile salmonids by vaccination against bacterial kidney disease have been disappointing, thus underscoring a basic need for a better understanding of protective mechanisms in salmonids. The recent development of more sensitive and quantitative detection methods should aid in evaluating the efficacy of current and future control strategies.

  9. The dynamics of spreading bacterial diseases and ilnesses caused by helminthosis in Adjara Autonomous Republic 2011.

    PubMed

    Lomtatidze, N; Chachnelidze, R; Chkaidze, M

    2013-01-01

    According to the data of past few years it has been determined that the general incidence and the prevalence of the bacterial and helminthosis diseases have increased. Epidemic Supervision has registered a slight increase of such diseases in data of 2011. Taking into consideration this fact, this research is quite important for the region of Adjara. The aim of our research is to study the dynamics of spreading some bacterial and helminthosis diseases in Adjara Autonomous Republic. In particular, the diseases caused by different bacterias of leptospira family - leptospirosis and illnesses caused by helminthosis - ascariasis, enterobiasis and trichocephalosis. according to the reseaches held it has been determined that there have been several cases of leptospirosis registered in Adjara. Specifically, 10 cases in 2008, 6 in 2009, 30 in 2010 and 31 cases in 2011 out of which 10 of the cases where laboratorily claimed. There were cases of ascariasis, enterobiasis and trichocephalosis. According to data, there are 5 times less cases of trichocephalosis than of ascariasis. As for enterobiasis, it's less than ascariasis (the difference is 205 cases). In therms of the aging, all the cases occur more frequently in the group of children below the age of 14. PMID:23388532

  10. Invited review: Role of bacterial endotoxins in the etiopathogenesis of periparturient diseases of transition dairy cows.

    PubMed

    Eckel, Emily F; Ametaj, Burim N

    2016-08-01

    The dairy industry continues to suffer severe economic losses due to the increased disease incidence cows experience during the transition period. It has long been the classical view that the major contributing factor to the development of these periparturient diseases is the considerable increase in nutritional demands for milk production. This classical view, however, fails to account for the substantial correlation between both metabolic and infectious diseases and the detrimental effects that can occur with the provision of high-energy diets to support these nutritional demands. Currently, increasing evidence implicates bacterial endotoxins in the etiopathology of most periparturient diseases. Bacterial endotoxins are components of the outer cell wall of gram-negative and gram-positive bacteria that are highly immunostimulatory and can trigger proinflammatory immune responses. The ability of endotoxins to translocate from the mucosal tissues, including the gastrointestinal tract, mammary gland, and uterus, into the systemic circulation has been observed. Once they have entered the circulation, endotoxins potentially contribute to disease either directly, through eliciting an inflammatory response, or indirectly through other factors such as the overreaction of the natural protective mechanisms of the host. Although the evidence implicating a role of endotoxins in the pathogenesis of transition diseases continues to grow, our current knowledge of the host response to mucosal endotoxin exposure and pathogenic mechanisms remain largely unknown. Developing our understanding of the connection between endotoxemia and dairy cattle disease holds significant potential for the future development of preventative measures that could benefit the productivity of the dairy industry as well as animal welfare. PMID:27209132

  11. Development of a Vaccine for Bacterial Kidney Disease in Salmon, 1986 Annual Report.

    SciTech Connect

    Kaattari, Stephen L.

    1987-06-01

    Bacterial kidney disease (BRD) has been and remains a chronic contributory problem limiting the productivity of salmon of the Columbia River Basin. Control of this disease will not come easily, but it would lead to a tremendous increase in the health and numbers of salmon populations. Vaccination of salmon of Renibacterium salmoninarum (KDB) is a potentially successful method of controlling this disease. To date, however, no successful vaccine has been developed for general use. A possible solution to this problem,and thus the goal of this research, is to isolate the antigenic components of KDB and enhance their ability to activate the host defenses. This will be accomplished by the chemical modification of these antigens with potent immunomodulatory substances. These modified antigens will then be tested for their effectiveness in inducing immunity to BKD and thereby preventing the disease. The goal of the project's third year was to test the immunogenicity and prophylactic value in coho salmon (Oncorhynchus kisutch) of various chemical conjugates of Renibacterium salmoninarum cells and major antigens. This was accomplished by assessing the serum antibody response, the cellular immune response (cellular proliferation), and the kinetics of mortality after Lethal injections of the bacterium. An important facet of this research is the identification and isolation of virulence factors. These studies are not only important to the dissection of the mechanism of pathogenesis of bacterial kidney disease, but the purification of such a factor(s) will insure the production of a more potent vaccine. The studies completed this year have: (1) identified antigenic material which protect; (2) identified antigenic material which can exacerbate the disease; (3) identified a possibly major mechanism of pathogenesis via the interference with antibody; (4) the general ability to produce delineated a western blot technique for identification of infected fish; (5) described the use of

  12. Development of a Vaccine for Bacterial Kidney Disease in Salmon, 1987 Annual Report.

    SciTech Connect

    Kaattari, Stephen

    1988-06-01

    Bacterial kidney disease (BKD) has been and remains a chronic contributory problem limiting the productivity of salmon in the Columbia River Basin. Control of this disease will not come easily, but it would lead to a tremendous increase in the health and numbers of salmon populations. Vaccination of salmon to Renibacterium salmoninarum (KDB) is a potentially successful method of controlling this disease. To date, however, no successful vaccine has been developed for general use. A possible solution to this problem, and thus the goal of this research, is to isolate the antigenic components of KDB and enhance their ability to activate the host defenses. This will be accomplished by the chemical modification of these antigens with potent immunomodulatory substances. These modified antigens will then be tested for their effectiveness in inducing immunity to BKD and thereby preventing the disease. The goal of the project's fourth year was to test the immunogenicity and prophylactic value in coho salmon (Oncorhynchus kisutch) of various--chemical conjugates of Renibacterium salmoninarum cell and major antigens. This was accomplished by assessing the serum antibody response, the cellular immune response (chemiluminescence), and the kinetics of mortality after lethal injections of the bacteria. The studies completed this year have: (1) identified immunization procedures which enhance the induction of high levels of antibody; (2) identified functionally distinct serum antibodies which may possess different abilities to protect salmon against BKD; (3) begun the isolation and characterization of anti-R. salmoninarum antibodies which may correlate with varying degrees of protection; (4) identified chemiluminescence as a potential method for assessing cellular immunity to bacterial kidney disease; and (5) characterized two monoclonal antibodies to R. salmoninarum which will be of benefit in the diagnosis of this disease.

  13. Cystic fibrosis pigs develop lung disease and exhibit defective bacterial eradication at birth.

    PubMed

    Stoltz, David A; Meyerholz, David K; Pezzulo, Alejandro A; Ramachandran, Shyam; Rogan, Mark P; Davis, Greg J; Hanfland, Robert A; Wohlford-Lenane, Chris; Dohrn, Cassie L; Bartlett, Jennifer A; Nelson, George A; Chang, Eugene H; Taft, Peter J; Ludwig, Paula S; Estin, Mira; Hornick, Emma E; Launspach, Janice L; Samuel, Melissa; Rokhlina, Tatiana; Karp, Philip H; Ostedgaard, Lynda S; Uc, Aliye; Starner, Timothy D; Horswill, Alexander R; Brogden, Kim A; Prather, Randall S; Richter, Sandra S; Shilyansky, Joel; McCray, Paul B; Zabner, Joseph; Welsh, Michael J

    2010-04-28

    Lung disease causes most of the morbidity and mortality in cystic fibrosis (CF). Understanding the pathogenesis of this disease has been hindered, however, by the lack of an animal model with characteristic features of CF. To overcome this problem, we recently generated pigs with mutated CFTR genes. We now report that, within months of birth, CF pigs spontaneously developed hallmark features of CF lung disease, including airway inflammation, remodeling, mucus accumulation, and infection. Their lungs contained multiple bacterial species, suggesting that the lungs of CF pigs have a host defense defect against a wide spectrum of bacteria. In humans, the temporal and causal relations between inflammation and infection have remained uncertain. To investigate these processes, we studied newborn pigs. Their lungs showed no inflammation but were less often sterile than controls. Moreover, after introduction of bacteria into their lungs, pigs with CF failed to eradicate bacteria as effectively as wild-type pigs. These results suggest that impaired bacterial elimination is the pathogenic event that initiates a cascade of inflammation and pathology in CF lungs. Our finding that pigs with CF have a host defense defect against bacteria within hours of birth provides an opportunity to further investigate CF pathogenesis and to test therapeutic and preventive strategies that could be deployed before secondary consequences develop. PMID:20427821

  14. Culturable Bacterial Microbiota of the Stomach of Helicobacter pylori Positive and Negative Gastric Disease Patients

    PubMed Central

    Khosravi, Yalda; Dieye, Yakhya; Poh, Bee Hoon; Ng, Chow Goon; Loke, Mun Fai; Goh, Khean Lee; Vadivelu, Jamuna

    2014-01-01

    Human stomach is the only known natural habitat of Helicobacter pylori (Hp), a major bacterial pathogen that causes different gastroduodenal diseases. Despite this, the impact of Hp on the diversity and the composition of the gastric microbiota has been poorly studied. In this study, we have analyzed the culturable gastric microbiota of 215 Malaysian patients, including 131 Hp positive and 84 Hp negative individuals that were affected by different gastric diseases. Non-Hp bacteria isolated from biopsy samples were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry based biotyping and 16SrRNA sequencing. The presence of Hp did not significantly modify the diversity of the gastric microbiota. However, correlation was observed between the isolation of Streptococci and peptic ulcer disease. In addition, as a first report, Burkholderia pseudomallei was also isolated from the gastric samples of the local population. This study suggested that there may be geographical variations in the diversity of the human gastric microbiome. Geographically linked diversity in the gastric microbiome and possible interactions between Hp and other bacterial species from stomach microbiota in pathogenesis are proposed for further investigations. PMID:25105162

  15. Both msa genes in Renibacterium salmoninarum are needed for full virulence in bacterial kidney disease

    USGS Publications Warehouse

    Coady, A.M.; Murray, A.L.; Elliott, D.G.; Rhodes, L.D.

    2006-01-01

    Renibacterium salmoninarum, a gram-positive diplococcobacillus that causes bacterial kidney disease among salmon and trout, has two chromosomal loci encoding the major soluble antigen (msa) gene. Because the MSA protein is widely suspected to be an important virulence factor, we used insertion-duplication mutagenesis to generate disruptions of either the msa1 or msa2 gene. Surprisingly, expression of MSA protein in broth cultures appeared unaffected. However, the virulence of either mutant in juvenile Chinook salmon (Oncorhynchus tshawytscha) by intraperitoneal challenge was severely attenuated, suggesting that disruption of the msa1 or msa2 gene affected in vivo expression. Copyright ?? 2006, American Society for Microbiology. All Rights Reserved.

  16. A review of rifaximin and bacterial overgrowth in poorly responsive celiac disease.

    PubMed

    Chang, Matthew S; Green, Peter H R

    2012-01-01

    A proportion of patients with celiac disease have a poor response to a gluten-free diet, which may be due to small-intestinal bacterial overgrowth (SIBO). Treatment with rifaximin is often used in the clinical setting, but there is limited literature to support this practice. In addition, challenges in the diagnosis of SIBO confound response interpretation. Our recent placebo-controlled trial did not demonstrate any improvement in gastrointestinal symptoms after treatment with rifaximin and casts doubt on the utility of lactulose-hydrogen breath testing for SIBO in this population. PMID:22282706

  17. A review of rifaximin and bacterial overgrowth in poorly responsive celiac disease

    PubMed Central

    Chang, Matthew S.

    2012-01-01

    A proportion of patients with celiac disease have a poor response to a gluten-free diet, which may be due to small-intestinal bacterial overgrowth (SIBO). Treatment with rifaximin is often used in the clinical setting, but there is limited literature to support this practice. In addition, challenges in the diagnosis of SIBO confound response interpretation. Our recent placebo-controlled trial did not demonstrate any improvement in gastrointestinal symptoms after treatment with rifaximin and casts doubt on the utility of lactulose–hydrogen breath testing for SIBO in this population. PMID:22282706

  18. Both msa genes in Renibacterium salmoninarum are needed for full virulence in bacterial kidney disease.

    PubMed

    Coady, Alison M; Murray, Anthony L; Elliott, Diane G; Rhodes, Linda D

    2006-04-01

    Renibacterium salmoninarum, a gram-positive diplococcobacillus that causes bacterial kidney disease among salmon and trout, has two chromosomal loci encoding the major soluble antigen (msa) gene. Because the MSA protein is widely suspected to be an important virulence factor, we used insertion-duplication mutagenesis to generate disruptions of either the msa1 or msa2 gene. Surprisingly, expression of MSA protein in broth cultures appeared unaffected. However, the virulence of either mutant in juvenile chinook salmon (Oncorhynchus tshawytscha) by intraperitoneal challenge was severely attenuated, suggesting that disruption of the msa1 or msa2 gene affected in vivo expression. PMID:16597972

  19. Both msa Genes in Renibacterium salmoninarum Are Needed for Full Virulence in Bacterial Kidney Disease

    PubMed Central

    Coady, Alison M.; Murray, Anthony L.; Elliott, Diane G.; Rhodes, Linda D.

    2006-01-01

    Renibacterium salmoninarum, a gram-positive diplococcobacillus that causes bacterial kidney disease among salmon and trout, has two chromosomal loci encoding the major soluble antigen (msa) gene. Because the MSA protein is widely suspected to be an important virulence factor, we used insertion-duplication mutagenesis to generate disruptions of either the msa1 or msa2 gene. Surprisingly, expression of MSA protein in broth cultures appeared unaffected. However, the virulence of either mutant in juvenile chinook salmon (Oncorhynchus tshawytscha) by intraperitoneal challenge was severely attenuated, suggesting that disruption of the msa1 or msa2 gene affected in vivo expression. PMID:16597972

  20. Bacterial community associated to the pine wilt disease insect vectors Monochamus galloprovincialis and Monochamus alternatus.

    PubMed

    Alves, Marta; Pereira, Anabela; Matos, Patrícia; Henriques, Joana; Vicente, Cláudia; Aikawa, Takuya; Hasegawa, Koichi; Nascimento, Francisco; Mota, Manuel; Correia, António; Henriques, Isabel

    2016-01-01

    Monochamus beetles are the dispersing vectors of the nematode Bursaphelenchus xylophilus, the causative agent of pine wilt disease (PWD). PWD inflicts significant damages in Eurasian pine forests. Symbiotic microorganisms have a large influence in insect survival. The aim of this study was to characterize the bacterial community associated to PWD vectors in Europe and East Asia using a culture-independent approach. Twenty-three Monochamus galloprovincialis were collected in Portugal (two different locations); twelve Monochamus alternatus were collected in Japan. DNA was extracted from the insects' tracheas for 16S rDNA analysis through denaturing gradient gel electrophoresis and barcoded pyrosequencing. Enterobacteriales, Pseudomonadales, Vibrionales and Oceanospirilales were present in all samples. Enterobacteriaceae was represented by 52.2% of the total number of reads. Twenty-three OTUs were present in all locations. Significant differences existed between the microbiomes of the two insect species while for M. galloprovincialis there were no significant differences between samples from different Portuguese locations. This study presents a detailed description of the bacterial community colonizing the Monochamus insects' tracheas. Several of the identified bacterial groups were described previously in association with pine trees and B. xylophilus, and their previously described functions suggest that they may play a relevant role in PWD. PMID:27045340

  1. Bacterial community associated to the pine wilt disease insect vectors Monochamus galloprovincialis and Monochamus alternatus

    PubMed Central

    Alves, Marta; Pereira, Anabela; Matos, Patrícia; Henriques, Joana; Vicente, Cláudia; Aikawa, Takuya; Hasegawa, Koichi; Nascimento, Francisco; Mota, Manuel; Correia, António; Henriques, Isabel

    2016-01-01

    Monochamus beetles are the dispersing vectors of the nematode Bursaphelenchus xylophilus, the causative agent of pine wilt disease (PWD). PWD inflicts significant damages in Eurasian pine forests. Symbiotic microorganisms have a large influence in insect survival. The aim of this study was to characterize the bacterial community associated to PWD vectors in Europe and East Asia using a culture-independent approach. Twenty-three Monochamus galloprovincialis were collected in Portugal (two different locations); twelve Monochamus alternatus were collected in Japan. DNA was extracted from the insects’ tracheas for 16S rDNA analysis through denaturing gradient gel electrophoresis and barcoded pyrosequencing. Enterobacteriales, Pseudomonadales, Vibrionales and Oceanospirilales were present in all samples. Enterobacteriaceae was represented by 52.2% of the total number of reads. Twenty-three OTUs were present in all locations. Significant differences existed between the microbiomes of the two insect species while for M. galloprovincialis there were no significant differences between samples from different Portuguese locations. This study presents a detailed description of the bacterial community colonizing the Monochamus insects’ tracheas. Several of the identified bacterial groups were described previously in association with pine trees and B. xylophilus, and their previously described functions suggest that they may play a relevant role in PWD. PMID:27045340

  2. Development of a Vaccine for Bacterial Kidney Disease in Salmon, 1985 Annual Report.

    SciTech Connect

    Kaattari, Stephen L.

    1986-06-01

    Bacterial kidney disease (BRD) has been and remains a chronic contributory problem limiting the productivity of salmon in the Columbia River Basin. Control of this disease will not come easily, but it would lead to a tremendous increase in the health and numbers of salmon populations. Vaccination of salmon to Renibacterium salmoninarum (KDB) is a potentially successful method of controlling this disease. To date, however, no successful vaccine has been developed for general use. A possible solution to this problem, and thus the goal of this research, is to isolate the antigenic components of KDB and enhance their ability to activate the host defenses. This will be accomplished by the chemical modification of these antigens with potent immunomodulatory substances. These modified antigens will then be tested for their effectiveness in inducing immunity to BKD and thereby preventing the disease. The goal of the project's second year was to chemically modify the major antigens of Renibacteirium salmoninarum, immunize coho salmon (Oncorhynchus kisutch), and to test the immunogenicity of the preparations used. Immunogenicity of the antigenic material was tested by (1) admixture experiments, using whole KD cells with muramyl dipepetide, Vibrio anguillarum extract, E. coli lipopolysaccharide, or Mycobacterium tuberculosis in Freund's complete adjuvant. In addition to these goals a number of important techniques have been developed in order to facilitate the production of the vaccine. These procedures include: (1) the use of the soluble antigen for diagnosis in the ELISA and Western blot analysis, (2) detection of salmonid anti-KD antibodies by an ELISA technique, (3) detection of cellular immune responses to the soluble antigen, and (4) development of immersion challenge procedures for bacterial kidney disease (BKD).

  3. Extensive cervical lymphadenitis mimicking bacterial adenitis as the first presentation of Kawasaki disease

    PubMed Central

    Rossi, Felipe de Souza; da Silva, Marco Felipe Castro; Kozu, Kátia Tomie; Camargo, Luís Fernando Aranha; Rossi, Flávia Feijó Panico; Silva, Clovis Artur; Campos, Lúcia Maria de Arruda

    2015-01-01

    Cervical adenitis >1.5cm in diameter is the less frequently observed criteria in patients with Kawasaki disease and it is usually found in association with other symptoms during the acute phase. Moreover, the finding of fever and lymphadenitis with intense local signs of inflammation and phlegmon is rarely seen as the initial manifestation of Kawasaki disease. We report the case of a 7-year-old boy who had cervical lymphadenitis with adjacent cellulitis and phlegmon mimicking bacterial adenitis as the first presentation of Kawasaki disease. The patient had fever, cervical lymphadenitis with adjacent cellulitis, and severe headache. Cefadroxil was prescribed based on the clinical diagnosis of bacterial adenitis. Because he remained febrile and phlogistic signs worsened, after 1 day of hospitalization, antibiotics were administrated intravenously (ceftriaxone and oxacillin). The computed tomography of the neck showed primary infectious/inflammatory process. On the fourth day, the patient had dry and scaly lips, and treatment with oxacillin was replaced by clindamycin because the patient was still febrile. On the ninth day, he presented non-exudative bilateral conjunctival injection. On the tenth day of febrile disease, a rash appeared on his trunk, hands and feet. Patient’s symptoms resolved after intravenous administration of immunoglobulin (2g/kg/dose), and he was discharged 2 days later. On the 14th day, the patient had lamellar desquamation of fingers. Kawasaki disease should be considered as a differential diagnosis in children with febrile cervical lymphadenitis unresponsive to empiric antibiotics even if they have adjacent cellulitis and phlegmon. PMID:26132362

  4. Outgrowth of the Bacterial Airway Microbiome after Rhinovirus Exacerbation of Chronic Obstructive Pulmonary Disease

    PubMed Central

    Molyneaux, Philip L.; Mallia, Patrick; Cox, Michael J.; Footitt, Joseph; Willis-Owen, Saffron A. G.; Homola, Daniel; Trujillo-Torralbo, Maria-Belen; Elkin, Sarah; Kon, Onn Min; Cookson, William O. C.; Johnston, Sebastian L.

    2013-01-01

    Rationale: Rhinovirus infection is followed by significantly increased frequencies of positive, potentially pathogenic sputum cultures in chronic obstructive pulmonary disease (COPD). However, it remains unclear whether these represent de novo infections or an increased load of organisms from the complex microbial communities (microbiome) in the lower airways. Objectives: To investigate the effect of rhinovirus infection on the airway bacterial microbiome. Methods: Subjects with COPD (n = 14) and healthy control subjects with normal lung function (n = 17) were infected with rhinovirus. Induced sputum was collected at baseline before rhinovirus inoculation and again on Days 5, 15, and 42 after rhinovirus infection and DNA was extracted. The V3–V5 region of the bacterial 16S ribosomal RNA gene was amplified and pyrosequenced, resulting in 370,849 high-quality reads from 112 of the possible 124 time points. Measurements and Main Results: At 15 days after rhinovirus infection, there was a sixfold increase in 16S copy number (P = 0.007) and a 16% rise in numbers of proteobacterial sequences, most notably in potentially pathogenic Haemophilus influenzae (P = 2.7 × 10-20), from a preexisting community. These changes occurred only in the sputum microbiome of subjects with COPD and were still evident 42 days after infection. This was in contrast to the temporal stability demonstrated in the microbiome of healthy smokers and nonsmokers. Conclusions: After rhinovirus infection, there is a rise in bacterial burden and a significant outgrowth of Haemophilus influenzae from the existing microbiota of subjects with COPD. This is not observed in healthy individuals. Our findings suggest that rhinovirus infection in COPD alters the respiratory microbiome and may precipitate secondary bacterial infections. PMID:23992479

  5. Citrus Canker and Citrus Huanglongbing, Two Exotic Bacterial Diseases Threatening the Citrus Industries of the Western Hemisphere

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two exotic Asian bacterial diseases of citrus are currently plaguing citrus industries in the Western Hemisphere. The two largest citrus producing areas in the Americas, located in Florida and the state of São Paulo Brazil, are presently battling these devastating diseases. The presence of these d...

  6. Development of practical diagnostic methods for monitoring rice bacterial panicle blight disease and evaluation of rice germplasm for resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was initiated to understand Burkholderia glumae, the major causal agent for bacterial panicle blight disease of rice; to develop practical diagnostic methods for monitoring the disease; and to evaluate rice germplasm for resistance. Burkholderia glumae was frequently isolated from infected p...

  7. Development of practical diagnostic methods for monitoring rice bacterial panicle blight disease and evaluation of rice germplasm for resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was initiated to understand Burkholderia glumae (major causal agent for bacterial panicle blight disease of rice) to develop practical diagnostic methods for monitoring the disease; and to evaluate rice germplasm for resistance. B. glumae was frequently isolated from symptomatic panicles on...

  8. Circulating Angiogenic Factors as Biomarkers of Disease Severity and Bacterial Burden in Pulmonary Tuberculosis

    PubMed Central

    Kumar, Nathella Pavan; Banurekha, Vaithilingam V.; Nair, Dina; Babu, Subash

    2016-01-01

    Background Angiogenesis and lymphangiogenesis are classical features of granuloma formation in pulmonary tuberculosis (PTB). In addition, the angiogenic factor—VEGF-A is a known biomarker for PTB. Aims/Methodology To examine the association of circulating angiogenic factors with PTB, we examined the systemic levels of VEGF-A, VEGF-C, VEGF-D, VEGF-R1, VEGF-R2 and VEGF-R3in individuals with PTB, latent TB (LTB) or no TB infection (NTB). Results Circulating levels of VEGF-A, VEGF-C andVEGF-R2 were significantly higher in PTB compared to LTB or NTB individuals. Moreover, the levels of VEGF-A, VEGF-C and VEGF-R2 were significantly higher in PTB with bilateral and/or cavitary disease. The levels of these factors also exhibited a significant positive relationship with bacterial burdens in PTB. ROC analysis revealed VEGF-A and VEGF-R2 as markers distinguishing PTB from LTB or NTB. Finally, the circulating levels of all the angiogenic factors examined were significantly reduced following successful chemotherapy. Conclusion Therefore, our data demonstrate that PTB is associated with elevated levels of circulating angiogenic factors, possibly reflecting vascular and endothelial dysfunction. In addition, some of these circulating angiogenic factors could prove useful as biomarkers to monitor disease severity, bacterial burden and therapeutic responses. PMID:26727122

  9. Possible association between celiac disease and bacterial transglutaminase in food processing: a hypothesis.

    PubMed

    Lerner, Aaron; Matthias, Torsten

    2015-08-01

    The incidence of celiac disease is increasing worldwide, and human tissue transglutaminase has long been considered the autoantigen of celiac disease. Concomitantly, the food industry has introduced ingredients such as microbial transglutaminase, which acts as a food glue, thereby revolutionizing food qualities. Several observations have led to the hypothesis that microbial transglutaminase is a new environmental enhancer of celiac disease. First, microbial transglutaminase deamidates/transamidates glutens such as the endogenous human tissue transglutaminase. It is capable of crosslinking proteins and other macromolecules, thereby changing their antigenicity and resulting in an increased antigenic load presented to the immune system. Second, it increases the stability of protein against proteinases, thus diminishing foreign protein elimination. Infections and the crosslinked nutritional constituent gluten and microbial transglutaminase increase the permeability of the intestine, where microbial transglutaminases are necessary for bacterial survival. The resulting intestinal leakage allows more immunogenic foreign molecules to induce celiac disease. The increased use of microbial transglutaminase in food processing may promote celiac pathogenesis ex vivo, where deamidation/transamidation starts, possibly explaining the surge in incidence of celiac disease. If future research substantiates this hypothesis, the findings will affect food product labeling, food additive policies of the food industry, and consumer health education. PMID:26084478

  10. Possible association between celiac disease and bacterial transglutaminase in food processing: a hypothesis

    PubMed Central

    Matthias, Torsten

    2015-01-01

    The incidence of celiac disease is increasing worldwide, and human tissue transglutaminase has long been considered the autoantigen of celiac disease. Concomitantly, the food industry has introduced ingredients such as microbial transglutaminase, which acts as a food glue, thereby revolutionizing food qualities. Several observations have led to the hypothesis that microbial transglutaminase is a new environmental enhancer of celiac disease. First, microbial transglutaminase deamidates/transamidates glutens such as the endogenous human tissue transglutaminase. It is capable of crosslinking proteins and other macromolecules, thereby changing their antigenicity and resulting in an increased antigenic load presented to the immune system. Second, it increases the stability of protein against proteinases, thus diminishing foreign protein elimination. Infections and the crosslinked nutritional constituent gluten and microbial transglutaminase increase the permeability of the intestine, where microbial transglutaminases are necessary for bacterial survival. The resulting intestinal leakage allows more immunogenic foreign molecules to induce celiac disease. The increased use of microbial transglutaminase in food processing may promote celiac pathogenesis ex vivo, where deamidation/transamidation starts, possibly explaining the surge in incidence of celiac disease. If future research substantiates this hypothesis, the findings will affect food product labeling, food additive policies of the food industry, and consumer health education. PMID:26084478

  11. On-farm performance of rainbow trout (Oncorhynchus mykiss) selectively bred for resistance to bacterial cold water disease: effect of rearing environment on survival phenotype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selective fish breeding programs for disease resistance comprise an increasingly important role in aquaculture production and offer an additional management tool for reducing bacterial-caused disease losses. Bacterial cold water disease (BCWD) is one of the most frequent causes of elevated mortalit...

  12. Risk of group A meningococcal disease: bacterial interference and cross-reactive bacteria among mucosal flora.

    PubMed

    Filice, G A; Hayes, P S; Counts, G W; Griffiss, J M; Fraser, D W

    1985-08-01

    During outbreaks of group A meningococcal disease in Seattle, Wash., and Portland, Oreg., we studied the mucosal flora of the affected population and comparison groups to identify possible determinants of susceptibility and resistance to disease. Antimeningococcal immunoglobulin A can block the bactericidal activity of specific antibodies of other classes and has been associated with susceptibility in adults. We used immunoprecipitation and fluorescent-antibody techniques to detect mucosal microorganisms cross-reactive with group A meningococci that might have stimulated such antibodies. Cross-reactive strains of Bacillus pumilus and Streptococcus faecalis were found. Bacterial interference on mucosal surfaces has been shown to reduce susceptibility to other pathogens. With an agar overlay technique, we sought nasopharyngeal microorganisms that inhibited the growth of group A meningococci. Forty-five percent of subjects carried inhibitory strains representing at least nine different species. Inhibitory strains were less common (32%) in residents from "skid row" areas (see D.J. Bogue, Skid Row in American Cities, University of Chicago Press, for a comprehensive definition of these areas) than in a comparison group that did not experience meningococcal disease (61%), suggesting that their presence may be associated with resistance to acquisition of meningococci or to meningococcal disease. PMID:3928679

  13. Epidemiology and Control of Strawberry Bacterial Angular Leaf Spot Disease Caused by Xanthomonas fragariae.

    PubMed

    Kim, Da-Ran; Gang, Gun-Hye; Jeon, Chang-Wook; Kang, Nam Jun; Lee, Sang-Woo; Kwak, Youn-Sig

    2016-08-01

    Strawberry bacterial angular leaf spot (ALS) disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are 20°C and the pathogen suffers mortality above 32°C. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August), the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%). To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields. PMID:27493604

  14. Bacterial indicators of risk of diarrhoeal disease from drinking-water in the Philippines.

    PubMed Central

    Moe, C. L.; Sobsey, M. D.; Samsa, G. P.; Mesolo, V.

    1991-01-01

    Inadequate measures of water quality have been used in many studies of the health effects associated with water supplies in developing countries. The present 1-year epidemiological-microbiological study evaluated four bacterial indicators of tropical drinking-water quality (faecal coliforms, Escherichia coli, enterococci and faecal streptococci) and their relationship to the prevalence of diarrhoeal disease in a population of 690 under-2-year-olds in Cebu, Philippines. E. coli and enterococci were better predictors than faecal coliforms of the risk of waterborne diarrhoeal disease. Methods to enumerate E. coli and enterococci were less subject to interference from the thermotolerant, non-faecal organisms that are indigenous to tropical waters. Little difference was observed between the illness rates of children drinking good quality water (less than 1 E. coli per 100 ml) and those drinking moderately contaminated water (2-100 E. coli per 100 ml). Children drinking water with greater than 1000 E. coli per 100 ml had significantly higher rates of diarrhoeal disease than those drinking less contaminated water. This threshold effect suggests that in developing countries where the quality of drinking-water is good or moderate other transmission routes of diarrhoeal disease may be more important; however, grossly contaminated water is a major source of exposure to faecal contamination and diarrhoeal pathogens. PMID:1893505

  15. Epidemiology and Control of Strawberry Bacterial Angular Leaf Spot Disease Caused by Xanthomonas fragariae

    PubMed Central

    Kim, Da-Ran; Gang, Gun-hye; Jeon, Chang-Wook; Kang, Nam Jun; Lee, Sang-woo; Kwak, Youn-Sig

    2016-01-01

    Strawberry bacterial angular leaf spot (ALS) disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are 20°C and the pathogen suffers mortality above 32°C. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August), the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%). To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields. PMID:27493604

  16. The Influence of Host and Bacterial Genotype on the Development of Disseminated Disease with Mycobacterium tuberculosis

    PubMed Central

    Caws, Maxine; Thwaites, Guy; Dunstan, Sarah; Hawn, Thomas R.; Thi Ngoc Lan, Nguyen; Thuong, Nguyen Thuy Thuong; Stepniewska, Kasia; Huyen, Mai Nguyet Thu; Bang, Nguyen Duc; Huu Loc, Tran; Gagneux, Sebastien; van Soolingen, Dick; Kremer, Kristin; van der Sande, Marianne; Small, Peter; Thi Hoang Anh, Phan; Chinh, Nguyen Tran; Thi Quy, Hoang; Thi Hong Duyen, Nguyen; Quang Tho, Dau; Hieu, Nguyen T.; Torok, Estee; Hien, Tran Tinh; Dung, Nguyen Huy; Thi Quynh Nhu, Nguyen; Duy, Phan Minh; van Vinh Chau, Nguyen; Farrar, Jeremy

    2008-01-01

    The factors that govern the development of tuberculosis disease are incompletely understood. We hypothesized that some strains of Mycobacterium tuberculosis (M. tuberculosis) are more capable of causing disseminated disease than others and may be associated with polymorphisms in host genes responsible for the innate immune response to infection. We compared the host and bacterial genotype in 187 Vietnamese adults with tuberculous meningitis (TBM) and 237 Vietnamese adults with uncomplicated pulmonary tuberculosis. The host genotype of tuberculosis cases was also compared with the genotype of 392 cord blood controls from the same population. Isolates of M. tuberculosis were genotyped by large sequence polymorphisms. The hosts were defined by polymorphisms in genes encoding Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) and Toll-like receptor-2 (TLR-2). We found a significant protective association between the Euro-American lineage of M. tuberculosis and pulmonary rather than meningeal tuberculosis (Odds ratio (OR) for causing TBM 0.395, 95% confidence intervals (C.I.) 0.193–0.806, P = 0.009), suggesting these strains are less capable of extra-pulmonary dissemination than others in the study population. We also found that individuals with the C allele of TLR-2 T597C allele were more likely to have tuberculosis caused by the East-Asian/Beijing genotype (OR = 1.57 [95% C.I. 1.15–2.15]) than other individuals. The study provides evidence that M. tuberculosis genotype influences clinical disease phenotype and demonstrates, for the first time, a significant interaction between host and bacterial genotypes and the development of tuberculosis. PMID:18369480

  17. IgG subclass deficiency and sinopulmonary bacterial infections in patients with alcoholic liver disease.

    PubMed

    Spinozzi, F; Cimignoli, E; Gerli, R; Agea, E; Bertotto, A; Rondoni, F; Grignani, F

    1992-01-01

    Abnormalities in IgG subclass distribution were sought in serum samples and bronchoalveolar lavage fluid from 15 patients with alcoholic liver disease to explain their increased susceptibility to bacterial respiratory infections. Serum IgG4 deficiency alone or in association with low IgG2 levels was revealed in approximately 30% of patients with alcoholic liver disease. This fact prompted us to further investigate the immunoglobulin concentrations in broncho-alveolar lavage fluid, paying special attention to the distribution of IgA and IgG subclasses. IgA levels were found to be normal or slightly elevated. However, there were substantial defects in total IgG and IgG1 concentrations, often associated with reduced IgG2 and IgG4 levels, in approximately 70% of patients with alcoholic liver disease, which proved to be closely correlated with the number and type (pneumonia) of bacterial respiratory infections. A prospective study of intravenous immunoglobulin substitutive therapy involving two patients with recurrent pneumonia and very low serum IgG2 values demonstrated a reduction in the number of respiratory infectious episodes as well as an increase in both serum and, to a lesser extent, bronchoalveolar lavage fluid IgG1 and IgG2 levels. We identified immune defects that may represent an important pathogenetic mechanism that, when considered together with the alcohol-related suppression of alveolar macrophage and ciliary functions and the inhibition of leukocyte migration into the lungs, should help clarify the complex relationships between alcohol and immune defense. PMID:1728935

  18. Methods in plant foliar volatile organic compounds research.

    PubMed

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; Gauci, Vincent

    2015-12-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant-plant and plant-insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas analysis, usually based on gas chromatography and soft chemical ionization mass spectrometry. Until now, these techniques (especially the latter one) have been developed and used primarily by physicists and analytical scientists, who have used them in a wide range of scientific research areas (e.g., aroma, disease biomarkers, hazardous compound detection, atmospheric chemistry). The interdisciplinary nature of plant foliar VOC research has recently attracted the attention of biologists, bringing them into the field of applied environmental analytical sciences. In this paper, we review the sampling methods and available analytical techniques used in plant foliar VOC research to provide a comprehensive resource that will allow biologists moving into the field to choose the most appropriate approach for their studies. PMID:26697273

  19. Methods in plant foliar volatile organic compounds research1

    PubMed Central

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; Gauci, Vincent

    2015-01-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant–plant and plant–insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas analysis, usually based on gas chromatography and soft chemical ionization mass spectrometry. Until now, these techniques (especially the latter one) have been developed and used primarily by physicists and analytical scientists, who have used them in a wide range of scientific research areas (e.g., aroma, disease biomarkers, hazardous compound detection, atmospheric chemistry). The interdisciplinary nature of plant foliar VOC research has recently attracted the attention of biologists, bringing them into the field of applied environmental analytical sciences. In this paper, we review the sampling methods and available analytical techniques used in plant foliar VOC research to provide a comprehensive resource that will allow biologists moving into the field to choose the most appropriate approach for their studies. PMID:26697273

  20. Effect of Stress on Viral–Bacterial Synergy in Bovine Respiratory Disease: Novel Mechanisms to Regulate Inflammation

    PubMed Central

    Hodgson, P. D.; Aich, P.; Manuja, A.; Hokamp, K.; Roche, F. M.; Brinkman, F. S. L.; Potter, A.; Babiuk, L. A.

    2005-01-01

    The severity of bovine respiratory infections has been linked to a variety of factors, including environmental and nutritional changes, transportation, and social reorganization of weaned calves. Fatal respiratory infections, however, usually occur when a primary viral infection compromises host defences and enhances the severity of a secondary bacterial infection. This viral–bacterial synergy can occur by a number of different mechanisms and disease challenge models have been developed to analyse host responses during these respiratory infections. A primary bovine herpesvirus-1 (BHV-1) respiratory infection followed by a secondary challenge with Mannheimia haemolytica results in fatal bovine respiratory disease (BRD) and host responses to these two pathogens have been studied extensively. We used this disease model to demonstrate that stress significantly altered the viral–bacterial synergy resulting in fatal BRD. Functional genomic analysis revealed that BHV-1 infection enhanced toll-like receptors (TLR) expression and increased pro-inflammatory responses which contribute to the severity of a Mannheimia haemolytica infection. TLRs play a critical role in detecting bacterial infections and inducing pro-inflammatory responses. It is difficult to understand, however, how stress-induced corticosteroids could enhance this form of viral–bacterial synergy. Nuclear translocation of the glucocorticoid receptor activates cell signalling pathways which inhibit both TLR signalling and pro-inflammatory responses. The apparent conundrum between stress-induced corticosteroids and enhanced BRD susceptibility is discussed in terms of present data and previous investigations of stress and respiratory disease. PMID:18629190

  1. Type I Interferon Protects against Pneumococcal Invasive Disease by Inhibiting Bacterial Transmigration across the Lung

    PubMed Central

    LeMessurier, Kim S.; Häcker, Hans; Chi, Liying; Tuomanen, Elaine; Redecke, Vanessa

    2013-01-01

    Streptococcus pneumoniae infection is a leading cause of bacterial pneumonia, sepsis and meningitis and is associated with high morbidity and mortality. Type I interferon (IFN-I), whose contribution to antiviral and intracellular bacterial immunity is well established, is also elicited during pneumococcal infection, yet its functional significance is not well defined. Here, we show that IFN-I plays an important role in the host defense against pneumococci by counteracting the transmigration of bacteria from the lung to the blood. Mice that lack the type I interferon receptor (Ifnar1−/−) or mice that were treated with a neutralizing antibody against the type I interferon receptor, exhibited enhanced development of bacteremia following intranasal pneumococcal infection, while maintaining comparable bacterial numbers in the lung. In turn, treatment of mice with IFNβ or IFN-I-inducing synthetic double stranded RNA (poly(I:C)), dramatically reduced the development of bacteremia following intranasal infection with S. pneumoniae. IFNβ treatment led to upregulation of tight junction proteins and downregulation of the pneumococcal uptake receptor, platelet activating factor receptor (PAF receptor). In accordance with these findings, IFN-I reduced pneumococcal cell invasion and transmigration across epithelial and endothelial layers, and Ifnar1−/− mice showed overall enhanced lung permeability. As such, our data identify IFN-I as an important component of the host immune defense that regulates two possible mechanisms involved in pneumococcal invasion, i.e. PAF receptor-mediated transcytosis and tight junction-dependent pericellular migration, ultimately limiting progression from a site-restricted lung infection to invasive, lethal disease. PMID:24244159

  2. Modulation of cytokine release from colonic explants by bacterial antigens in inflammatory bowel disease.

    PubMed

    Dionne, S; Laberge, S; Deslandres, C; Seidman, E G

    2003-07-01

    The intestinal flora play an important role in experimental colitis and inflammatory bowel disease (IBD). Using colonic explant cultures from 132 IBD and control subjects, we examined tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 and interleukin-1 receptor antagonist (IL-1RA) production in vitro in response to bacterial activators. Unstimulated TNF-alpha release was increased significantly in rectal biopsies from involved IBD tissue, correlating with inflammation severity. Whereas lipopolysaccharide (LPS) only moderately stimulated TNF-alpha production from inflamed tissue, pokeweed mitogen (PWM) induced its release in all groups, with a stronger response in involved IBD tissue. Superantigen staphylococcal enterotoxin A (SEA) had a similar, but weaker effect. SEB was observed to be the strongest inducer of TNF-alpha for all groups, again with a more marked response in inflamed tissue. Stimulated release of IL-1 was considerably less than for TNF-alpha. The superantigens' superior potency over LPS was not as marked for IL-1 as it was for TNF-alpha. In addition to IL-1, IL-1RA release was also triggered by the bacterial products. The net effect of activation on the IL-1RA/IL-1 ratio was relatively modest. Release of the proinflammatory cytokines TNF-alpha and IL-1, as well as that of the anti-inflammatory cytokine IL-1RA was increased by incubation of colonic tissue with bacterial factors. TNF-alpha production and release was increased significantly in involved colonic explants from IBD. SEB was even capable of inducing TNF-alpha release from uninvolved colonic tissue. PMID:12823284

  3. Huanglongbing, a Systemic Disease, Restructures the Bacterial Community Associated with Citrus Roots▿

    PubMed Central

    Trivedi, Pankaj; Duan, Yongping; Wang, Nian

    2010-01-01

    To examine the effect of pathogens on the diversity and structure of plant-associated bacterial communities, we carried out a molecular analysis using citrus and huanglongbing as a host-disease model. 16S rRNA gene clone library analysis of citrus roots revealed shifts in microbial diversity in response to pathogen infection. The clone library of the uninfected root samples has a majority of phylotypes showing similarity to well-known plant growth-promoting bacteria, including Caulobacter, Burkholderia, Lysobacter, Pantoea, Pseudomonas, Stenotrophomonas, Bacillus, and Paenibacillus. Infection by “Candidatus Liberibacter asiaticus” restructured the native microbial community associated with citrus roots and led to the loss of detection of most phylotypes while promoting the growth of bacteria such as Methylobacterium and Sphingobacterium. In pairwise comparisons, the clone library from uninfected roots contained significantly higher 16S rRNA gene diversity, as reflected in the higher Chao 1 richness estimation (P ≤ 0.01) of 237.13 versus 42.14 for the uninfected and infected clone libraries, respectively. Similarly, the Shannon index of the uninfected clone library (4.46) was significantly higher than that of the infected clone library (2.61). Comparison of the uninfected clone library with the infected clone library using LIBSHUFF statistics showed a significant difference (P ≤ 0.05). Quantitative PCR analysis revealed that the bacterial community changes not only qualitatively but also quantitatively. The relative proportions of different groups of bacteria changed significantly after infection with the pathogen. These data indicate that infection of citrus by “Ca. Liberibacter asiaticus” has a profound effect on the structure and composition of the bacterial community associated with citrus roots. PMID:20382817

  4. Jellyfish as vectors of bacterial disease for farmed salmon (Salmo salar).

    PubMed

    Ferguson, Hugh W; Delannoy, Christian M J; Hay, Stephen; Nicolson, James; Sutherland, David; Crumlish, Margaret

    2010-05-01

    Swarms or blooms of jellyfish are increasingly problematic and can result in high mortality rates of farmed fish. Small species of jellyfish, such as Phialella quadrata (13 mm in diameter), are capable of passing through the mesh of sea cages and being sucked into the mouth of fish during respiration. Results of the current study show that the initial damage to gills of farmed Atlantic salmon, likely produced by nematocyst-derived toxins from the jellyfish, was compounded by secondary bacterial infection with Tenacibaculum maritimum. Results also demonstrate that these filamentous bacteria were present on the mouth of the jellyfish and that their DNA sequences were almost identical to those of bacteria present on the salmon gills. This suggests that the bacterial lesions were not the result of an opportunistic infection of damaged tissue, as previously thought. Instead, P. quadrata is probably acting as a vector for this particular bacterial pathogen, and it is the first time that evidence to support such a link has been presented. No prior literature describing the presence of bacteria associated with jellyfish, except studies about their decay, could be found. It is not known if all jellyfish of this and other species carry similar bacteria or the relationship to each other. Their source, the role they play under other circumstances, and indeed whether the jellyfish were themselves diseased are also not known. The high proteolytic capabilities of T. maritimum mean that partially digested gill tissues were readily available to the jellyfish, which rely heavily on intracellular digestion for their nutrition. PMID:20453210

  5. Interpreting dual ELISA and qPCR data for bacterial kidney disease of salmonids.

    PubMed

    Nance, Shelly L; Riederer, Michael; Zubkowski, Tyler; Trudel, Marc; Rhodes, Linda D

    2010-09-01

    Although there are a variety of methods available for the detection of Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmon and trout, the enzyme-linked immunosorbent assay (ELISA) is probably the most widely used method. However, ELISA measures bacterial antigen, which does not necessarily reflect the number of cells present. We hypothesized that dual analysis of kidney tissue by ELISA and a quantitative real-time polymerase chain reaction assay (qPCR) would provide complementary information about antigen level and the number of bacterial genomes. We found that DNA extracted from the insoluble fraction of the ELISA tissue preparation produced the same qPCR result as DNA extracted directly from frozen tissue, permitting true dual analysis of the same tissue sample. We examined kidney tissue in this manner from individual free-ranging juvenile Chinook salmon and antibiotic-treated captive subadult Chinook salmon and observed 3 different patterns of results. Among the majority of fish, there was a strong correlation between the ELISA value and the qPCR value. However, subsets of fish exhibited either low ELISA values with elevated qPCR values or higher ELISA values with very low qPCR values. These observations suggest a conceptual model that allows inferences about the state of infection of individual fish based on dual ELISA/qPCR results. Although this model requires further assessment through experimental infections and treatments, it may have utility in broodstock selection programs that currently apply egg-culling practices based on ELISA alone. PMID:21387990

  6. Evaluating clinical periodontal measures as surrogates for bacterial exposure: The Oral Infections and Vascular Disease Epidemiology Study (INVEST)

    PubMed Central

    2010-01-01

    Background Epidemiologic studies of periodontal infection as a risk factor for cardiovascular disease often use clinical periodontal measures as a surrogate for the underlying bacterial exposure of interest. There are currently no methodological studies evaluating which clinical periodontal measures best reflect the levels of subgingival bacterial colonization in population-based settings. We investigated the characteristics of clinical periodontal definitions that were most representative of exposure to bacterial species that are believed to be either markers, or themselves etiologic, of periodontal disease. Methods 706 men and women aged ≥ 55 years, residing in northern Manhattan were enrolled. Using DNA-DNA checkerboard hybridization in subgingival biofilms, standardized values for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were averaged within mouth and summed to define "bacterial burden". Correlations of bacterial burden with clinical periodontal constructs defined by the severity and extent of attachment loss (AL), pocket depth (PD) and bleeding on probing (BOP) were assessed. Results Clinical periodontal constructs demonstrating the highest correlations with bacterial burden were: i) percent of sites with BOP (r = 0.62); ii) percent of sites with PD ≥ 3 mm (r = 0.61); and iii) number of sites with BOP (r = 0.59). Increasing PD or AL severity thresholds consistently attenuated correlations, i.e., the correlation of bacterial burden with the percent of sites with PD ≥ 8 mm was only r = 0.16. Conclusions Clinical exposure definitions of periodontal disease should incorporate relatively shallow pockets to best reflect whole mouth exposure to bacterial burden. PMID:20056008

  7. Bacterial Sialidase

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Data shows that elevated sialidase in bacterial vaginosis patients correlates to premature births in women. Bacterial sialidase also plays a significant role in the unusual colonization of Pseudomonas aeruginosa in cystic fibrosis patients. Crystals of Salmonella sialidase have been reproduced and are used for studying the inhibitor-enzyme complexes. These inhibitors may also be used to inhibit a trans-sialidase of Trypanosome cruzi, a very similar enzyme to bacterial sialidase, therefore preventing T. cruzi infection, the causitive agent of Chagas' disease. The Center for Macromolecular Crystallography suggests that inhibitors of bacterial sialidases can be used as prophylactic drugs to prevent bacterial infections in these critical cases.

  8. Changes in sulfate-reducing bacterial populations during the onset of black band disease.

    PubMed

    Bourne, David G; Muirhead, Andrew; Sato, Yui

    2011-03-01

    Factors that facilitate the onset of black band disease (BBD) of corals remain elusive, though anoxic conditions under the complex microbial mat and production of sulfide are implicated in necrosis of underlying coral tissues. This study investigated the diversity and quantitative shifts of sulfate-reducing bacterial (SRB) populations during the onset of BBD using real-time PCR (RT-PCR) and cloning approaches targeting the dissimilatory (bi)sulfite reductase (dsrA) gene. A quantitative-PCR (qPCR) assay targeting the 16S rRNA gene also provided an estimate of total bacteria, and allowed the relative percentage of SRB within the lesions to be determined. Three Montipora sp. coral colonies identified with lesions previously termed cyanobacterial patches (CPs) (comprising microbial communities unlike those of BBD lesions), were tagged and followed through time as CP developed into BBD. The dsrA-targeted qPCR detected few copies of the gene in the CP samples (<65 per ng DNA), though copy numbers increased in BBD lesions (>2500 per ng DNA). SRB in CP samples were less than 1% of the bacterial population, though represented up to 7.5% of the BBD population. Clone libraries also demonstrated a shift in the dominant dsrA sequences as lesions shifted from CP into BBD. Results from this study confirm that SRB increase during the onset of BBD, likely increasing sulfide concentrations at the base of the microbial mat and facilitating the pathogenesis of BBD. PMID:20811471

  9. Changes in sulfate-reducing bacterial populations during the onset of black band disease

    PubMed Central

    Bourne, David G; Muirhead, Andrew; Sato, Yui

    2011-01-01

    Factors that facilitate the onset of black band disease (BBD) of corals remain elusive, though anoxic conditions under the complex microbial mat and production of sulfide are implicated in necrosis of underlying coral tissues. This study investigated the diversity and quantitative shifts of sulfate-reducing bacterial (SRB) populations during the onset of BBD using real-time PCR (RT-PCR) and cloning approaches targeting the dissimilatory (bi)sulfite reductase (dsrA) gene. A quantitativePCR (qPCR) assay targeting the 16S rRNA gene also provided an estimate of total bacteria, and allowed the relative percentage of SRB within the lesions to be determined. Three Montipora sp. coral colonies identified with lesions previously termed cyanobacterial patches (CPs) (comprising microbial communities unlike those of BBD lesions), were tagged and followed through time as CP developed into BBD. The dsrA-targeted qPCR detected few copies of the gene in the CP samples (<65 per ng DNA), though copy numbers increased in BBD lesions (>2500 per ng DNA). SRB in CP samples were less than 1% of the bacterial population, though represented up to 7.5% of the BBD population. Clone libraries also demonstrated a shift in the dominant dsrA sequences as lesions shifted from CP into BBD. Results from this study confirm that SRB increase during the onset of BBD, likely increasing sulfide concentrations at the base of the microbial mat and facilitating the pathogenesis of BBD. PMID:20811471

  10. Controlling Foliar Disease with ZeroTol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ZeroTol is a disinfestant labeled for direct application on plants. Laboratory, field, and greenhouse experiments were performed to determine the rates and intervals in days between applications needed to control daylily rust. In laboratory trials, a very high rate was required to achieve 100% morta...

  11. Controlling foliar disease with ZeroTol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrogen dioxide (H2O2) is a disinfestant used to kill fungal spores, such as urediniospores of Puccinia hemerocallidis, on plant and production surfaces. Excised sections of daylily leaves with sporulating rust pustules were sprayed with rates from 2.4 to 11.9% H2O2. Treated spores were rubbed onto...

  12. Genomics reveals historic and contemporary transmission dynamics of a bacterial disease among wildlife and livestock

    USGS Publications Warehouse

    Kamath, Pauline L.; Foster, Jeffrey T.; Drees, Kevin P.; Luikart, Gordon; Quance, Christine; Anderson, Neil J.; Clarke, P. Ryan; Cole, Eric K.; Drew, Mark L.; Edwards, William H.; Rhyan, Jack C.; Treanor, John J.; Wallen, Rick L.; White, Patrick J.; Robbe-Austerman, Suelee; Cross, Paul C.

    2016-01-01

    Whole-genome sequencing has provided fundamental insights into infectious disease epidemiology, but has rarely been used for examining transmission dynamics of a bacterial pathogen in wildlife. In the Greater Yellowstone Ecosystem (GYE), outbreaks of brucellosis have increased in cattle along with rising seroprevalence in elk. Here we use a genomic approach to examine Brucella abortus evolution, cross-species transmission and spatial spread in the GYE. We find that brucellosis was introduced into wildlife in this region at least five times. The diffusion rate varies among Brucella lineages (B3 to 8 km per year) and over time. We also estimate 12 host transitions from bison to elk, and 5 from elk to bison. Our results support the notion that free-ranging elk are currently a self-sustaining brucellosis reservoir and the source of livestock infections, and that control measures in bison are unlikely to affect the dynamics of unrelated strains circulating in nearby elk populations.

  13. Genomics reveals historic and contemporary transmission dynamics of a bacterial disease among wildlife and livestock.

    PubMed

    Kamath, Pauline L; Foster, Jeffrey T; Drees, Kevin P; Luikart, Gordon; Quance, Christine; Anderson, Neil J; Clarke, P Ryan; Cole, Eric K; Drew, Mark L; Edwards, William H; Rhyan, Jack C; Treanor, John J; Wallen, Rick L; White, Patrick J; Robbe-Austerman, Suelee; Cross, Paul C

    2016-01-01

    Whole-genome sequencing has provided fundamental insights into infectious disease epidemiology, but has rarely been used for examining transmission dynamics of a bacterial pathogen in wildlife. In the Greater Yellowstone Ecosystem (GYE), outbreaks of brucellosis have increased in cattle along with rising seroprevalence in elk. Here we use a genomic approach to examine Brucella abortus evolution, cross-species transmission and spatial spread in the GYE. We find that brucellosis was introduced into wildlife in this region at least five times. The diffusion rate varies among Brucella lineages (∼3 to 8 km per year) and over time. We also estimate 12 host transitions from bison to elk, and 5 from elk to bison. Our results support the notion that free-ranging elk are currently a self-sustaining brucellosis reservoir and the source of livestock infections, and that control measures in bison are unlikely to affect the dynamics of unrelated strains circulating in nearby elk populations. PMID:27165544

  14. Genomics reveals historic and contemporary transmission dynamics of a bacterial disease among wildlife and livestock

    PubMed Central

    Kamath, Pauline L.; Foster, Jeffrey T.; Drees, Kevin P.; Luikart, Gordon; Quance, Christine; Anderson, Neil J.; Clarke, P. Ryan; Cole, Eric K.; Drew, Mark L.; Edwards, William H.; Rhyan, Jack C.; Treanor, John J.; Wallen, Rick L.; White, Patrick J.; Robbe-Austerman, Suelee; Cross, Paul C.

    2016-01-01

    Whole-genome sequencing has provided fundamental insights into infectious disease epidemiology, but has rarely been used for examining transmission dynamics of a bacterial pathogen in wildlife. In the Greater Yellowstone Ecosystem (GYE), outbreaks of brucellosis have increased in cattle along with rising seroprevalence in elk. Here we use a genomic approach to examine Brucella abortus evolution, cross-species transmission and spatial spread in the GYE. We find that brucellosis was introduced into wildlife in this region at least five times. The diffusion rate varies among Brucella lineages (∼3 to 8 km per year) and over time. We also estimate 12 host transitions from bison to elk, and 5 from elk to bison. Our results support the notion that free-ranging elk are currently a self-sustaining brucellosis reservoir and the source of livestock infections, and that control measures in bison are unlikely to affect the dynamics of unrelated strains circulating in nearby elk populations. PMID:27165544

  15. Identification of multiple phytotoxins produced by Fusarium virguliforme including a phytotoxic effector (FvNIS1) associated with soybean sudden death syndrome foliar symptoms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxins produced by the soil-borne fungus, Fusarium virguliforme, cause foliar symptoms in soybean. The disease in soybean is referred to as soybean sudden death syndrome (SDS). Three toxins produced by the fungus were reported to be associated with SDS foliar symptoms, but none produced identical S...

  16. Two cycles of recurrent maternal half-sib selection reduce foliar late blight in a diploid hybrid Solanum phureja-S. stenotomum population by two-thirds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar late blight, caused by Phytophthora infestans, is an important disease problem worldwide. Foliar resistance to late blight was found in a hybrid population of the cultivated diploid species Solanum phureja-S. stenotomum (phu-stn). The objective of this study was to determine if resistance t...

  17. Influence of bacterial kidney disease on smoltification in salmonids: Is it a case of double jeopardy?

    USGS Publications Warehouse

    Mesa, M.G.; Maule, A.G.; Poe, T.P.; Schreck, C.B.

    1999-01-01

    We investigated the effects of a chronic, progressive infection with Renibacterium salmoninarum (Rs), the causative agent of bacterial kidney disease (BKD), on selected aspects of smoltification in yearling juvenile spring chinook salmon (Oncorhynchus tshawytscha). After experimentally infecting fish with Rs using an immersion challenge, we sampled them every two weeks to monitor changes in gill Na+, K+-ATPase (ATPase), cortisol, infection level, mortality, growth, and other stress-related physiological factors during the normal time of parr-smolt transformation in fresh water (i.e., from winter to spring). A progressively worsening infection with Rs did not alter the normal changes in gill ATPase and condition factor associated with smoltification in juvenile chinook salmon. The infection did, however, lead to elevated levels of plasma cortisol and lactate and depressed levels of plasma glucose, indicating that the disease is stressful during the later stages. A dramatic proliferation of BKD was associated with maximal responses of indicators of smoltification, suggesting that the process of smoltification itself can trigger outbreaks of disease. Our results suggest mechanisms that probably influence the reported inability of Rs-infected fish to successfully adapt to sea water.

  18. [Efficacy and safety of faropenem in pediatric patients with bacterial infectious diseases].

    PubMed

    Yokota, Takao; Azagami, Shiro; Abe, Takashi; Ozaki, Akira; Ojima, Tadashi; Koizumi, Yukihiko; Jozaki, Keijio; Cho, Hideo; Nakao, Ayumi; Nonoyama, Masato; Bamba, Masahiro; Hojo, Hideto; Sunakawa, Keisuke

    2008-12-01

    The only oral penem antibiotic, faropenem (FRPM: Farom Dry Syrup for pediatrics), is one of the few antibiotics that exerts potent antibacterial activity against penicillin-resistant Streptococcus pneumoniae (PRSP), and the dosage and administration schedule has been established for children. We studied the efficacy and safety of the drug in 113 pediatric patients with mild-to-moderate bacterial infectious diseases: upper respiratory tract infection (pharyngitis or tonsillitis), acute bronchitis, otitis media and urinary tract infection (UTI). The patients were administered oral FRPM at the dose of 15-30 mg/kg/day three times a day for 3 to 8 days (or 5 to 14 days for group A streptococcal infection). The study drug was found to be clinically effective in 63/70 cases (90.0%) of upper respiratory tract infection, 6/7 cases of acute bronchitis, 16/17 cases (94.1%) of otitis media and 6/6 cases of UTI. FRPM was demonstrated to have very potent antibacterial activity against S. pneumoniae, with a high bacteriological eradication rate. No serious adverse drug reactions were observed. The only side effect was diarrhea in 12.5% of the patients (14/112 cases). There was little difference in the incidence of diarrhea between FRPM and other oral beta-lactam antibiotics. Compliance with FRPM was found to be very good in this study. These findings suggest that FRPM is as useful for the treatment of bacterial infectious diseases in children as oral penicillin and cephem antibiotics. PMID:19288854

  19. Pathogens and diseases of freshwater mussels in the United States: Studies on bacterial transmission and depuration

    USGS Publications Warehouse

    Starliper, Clifford E.

    2011-01-01

    Unionid mussels are recognized as important contributors to healthy aquatic ecosystems, as well as bioindicators of environmental perturbations. Because they are sedentary, filter feeding animals and require hosts (i.e., fishes) to transform embryonic glochidia, mussels are susceptible to direct adverse environmental parameters, and indirect parameters that restrict the timely presence of the host(s). Their numbers have declined in recent decades to a point that this fauna is regarded as one of the most imperiled in North America. The most significant threat to populations of native unionids in recent years has been the introduction and spread of zebra mussels Dreissena polymorpha. Many federal and state agencies, and private interests are now engaged in mussel conservation efforts, including collecting selected imperiled species from impacted rivers and lakes and propagating them at refuges for future population augmentations. One essential consideration with mussel propagation and their intensive culture at refugia is the prevention of pathogen introductions and control of diseases. Currently, there are few reports of etiological agents causing diseases among freshwater mussels; however, because of increased observations of mussel die-offs in conjunction with transfers of live animals between natural waters and refugia, disease problems can be anticipated to emerge. This review summarizes research to develop bacterial isolation techniques, study pathogen transmission between fish and mussels, identify causes of seasonal mussel die-offs, and develop non-destructive methods for pathogen detection. These efforts were done to develop disease preventative techniques for use by resource managers to avoid potential large-scale disease problems in restoration and population augmentation efforts among imperiled populations.

  20. The Fusarium virguliforme toxin FvTox1 causes foliar sudden death syndrome-like symptoms in soybean.

    PubMed

    Brar, Hargeet K; Swaminathan, Sivakumar; Bhattacharyya, Madan K

    2011-10-01

    Fusarium virguliforme causes sudden death syndrome (SDS) in soybean. The pathogen has never been isolated from diseased foliar tissues; therefore, one or more toxins have been considered to cause foliar SDS development. Cell-free F. virguliforme culture filtrates containing a toxin causes foliar SDS in soybean. A low-molecular-weight protein of approximately 13.5 kDa (FvTox1), purified from F. virguliforme culture filtrates, produces foliar SDS-like symptoms in cut soybean seedlings. Anti-FvTox1 monoclonal antibodies raised against the purified FvTox1 were used in isolating the FvTox1 gene. In the presence of light, recombinant FvTox1 protein expressed in an insect cell line resulted in chlorosis and necrosis in soybean leaf disks that are typical foliar SDS symptoms. SDS-susceptible but not the SDS-resistant soybean lines were sensitive to the baculovirus-expressed toxin. The requirement of light for foliar SDS-like symptom development indicates that FvTox1 induces foliar SDS in soybean, most likely through production of free radicals by interrupting photosynthesis. PMID:21635141

  1. Bacterial assemblages shifts from healthy to yellow band disease states in the dominant reef coral Montastraea faveolata.

    PubMed

    Cróquer, Aldo; Bastidas, Carolina; Elliott, Amy; Sweet, Michael

    2013-02-01

    Descriptions of microbial diversity in healthy and diseased corals are necessary first steps before further investigating the mechanisms that lead to coral pathology. This is the first study that characterizes the microbial associates from healthy corals to yellow band disease (YBD) lesions using two complementary screening techniques of bacterial 16S rRNA genes [amplified 16S ribosomal DNA restriction analysis (ARDRA) of clone libraries and denaturing gradient gel electrophoresis (DGGE)]. Both these techniques showed similar trends, namely a significant difference in the bacterial community and an increase in diversity from healthy to YBD diseased lesions. There was an increase in the number of sequences retrieved of potentially pathogenic bacteria in diseased tissues compared with healthy samples, most notably from the genus Vibrio. Furthermore, we also detected a number of known pathogenic bacteria within the natural healthy microbiota such as Vibrio carchariae and Vibrio harveyi, a result supporting previous studies, showing healthy corals have the ability to harbour these species. PMID:23757136

  2. USE OF PORTABLE REAL-TIME PCR FOR SAME-DAY ON-SITE FIELD DIAGNOSIS OF BACTERIAL DISEASES.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diagnosing bacterial diseases can be very time consuming. Traditional isolation and pathogenicity tests are very sensitive but require 10-20 days or longer. Serological techniques can reduce the time, but the detection threshold is only 104 - 105 cfu/ml. Classical PCR is 10 times more sensitive t...

  3. A prospective matched nested case-control study of bacterial gill disease outbreaks in Ontario, Canada government salmonid hatcheries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early-rearing salmonids in Ontario, Canada government fish hatcheries have been persistently affected by bacterial gill disease (BGD), and outbreaks at these locations have often been associated with high morbidity and mortality. The causative agent of BGD, Flavobacterium branchiophilum, is consider...

  4. The effects of Zebra Chip disease development and bacterial titer on biochemical properties in relation to the time of infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato tuber biochemical responses to ‘Candidatus’ Liberibacter solanacearum (Lso), the causal agent of Zebra chip disease, were evaluated both within infected tubers and across different infection dates. Tuber biochemistry also was related to symptom severity and bacterial titer. Symptom severity w...

  5. Cloning of a very virulent plus, 686 strain of Marek’s disease virus as a bacterial artificial chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial artificial chromosome (BAC) vectors were first developed to facilitate propagation and manipulation of large DNA fragments. This technology was later used to clone full-length genomes of large DNA viruses to study viral gene function. Marek’s disease virus (MDV) is a highly oncogenic herpe...

  6. Identification of single nucleotide polymorphism markers associated with bacterial cold water disease resistance and spleen size in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) is one of the frequent causes of elevated mortality in salmonid aquaculture. Previously, we identified and validated microsatellites associated with QTL (quantitative trait loci) for BCWD resistance and spleen size in rainbow trout. The objective of this study was...

  7. Detection of quantitative trait loci (QTL) for resistance to bacterial cold water disease and spleen size in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation in survival following challenge with Flavobacterium psychrophilum, the causative agent of BCWD in rainbow trout, and a family-based selection program to improve res...

  8. Evidence of major genes affecting resistance to bacterial cold water disease in rainbow trout using Bayesian methods of segregation analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation for BCWD resistance in our rainbow trout population, and a family-based selection program to improve resistance was initiated at the National Center for Cool and Col...

  9. Identification of single nucleotide polymorphism markers associated with bacterial cold water disease resistance and spleen size in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) is one of the frequent causes of elevated mortality in salmonid aquaculture. Previously, we identified and validated microsatellite markers associated with QTL (quantitative trait loci) for BCWD resistance and spleen size in rainbow trout. The objective of this st...

  10. Factors associated with the incidence of bacterial gill disease in salmonid lots reared in Ontario, Canada government hatcheries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial gill disease (BGD) (causative agent: Flavobacterium branchiophilum) has been a persistent problem in early-rearing salmonids in the Ontario Ministry of Natural Resources (OMNR) fish hatchery system. Retrospective epidemiological investigations of BGD diagnoses and treatments in OMNR fish h...

  11. Rearing unit-level factors associated with bacterial gill disease treatment in two Ontario, Canada government salmonid hatcheries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early-rearing salmonids in Ontario Ministry of Natural Resources (OMNR)fish hatcheries have been consistently affected by bacterial gill disease (BGD)(causative agent: Flavobacterium branchiophilum) for many years. Separate retrospective epidemiological investigations of BGD treatments at two OMNR f...

  12. Evidence of major genes affecting bacterial cold water disease resistance in rainbow trout using Bayesian methods of complex segregation analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation for BCWD resistance in our rainbow trout population, and a family-based selection program to improve resistance was initiated at the NCCCWA in 2005. The main objec...

  13. Bacterial role in pine wilt disease development - review and future perspectives.

    PubMed

    Nascimento, Francisco X; Hasegawa, Koichi; Mota, Manuel; Vicente, Cláudia S L

    2015-02-01

    Mutualistic and beneficial relationships between nematodes and bacteria are highly present in nature, mostly occurring because of nutritional dependence and pathogen protection, and intrinsically related with the environment, the ecological conditions and the nematode life stages. Thirty-four years have passed since the first hypothesis suggesting a bacterial role in pine wilt disease (PWD), associated with the pinewood nematode (PWN), Bursaphelenchus xylophilus. In 1980, researchers reported that bacteria associated with the PWN could produce toxins that lead to PWD development in pine seedlings. It was also suggested a double vector system for PWD, where bacteria were vectored by the PWN and the PWN vectored by an insect from the Monochamus genus. Presently, the specific involvement of bacteria in such complex disease is still controversial, even though the increased number of studies focused on the potential bacteria role has increased considerably. This review is an up-to-date comprehensive perspective and brings new insights on the role of PWN-associated bacteria in PWD. PMID:25139220

  14. Water Extract from Spent Mushroom Substrate of Hericium erinaceus Suppresses Bacterial Wilt Disease of Tomato

    PubMed Central

    Kwak, A Min; Min, Kyeong Jin; Lee, Sang Yeop

    2015-01-01

    Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium carotovorum subsp. carotovorum, Agrobacterium tumefaciens, R. solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, X. axonopodis pv. vesicatoria, X. axonopodis pv. citiri, and X. axonopodis pv. glycine. Quantitative real-time PCR revealed that water extracts of SMS (WESMS) of H. erinaceus induced expressions of plant defense genes encoding β-1,3-glucanase (GluA) and pathogenesis-related protein-1a (PR-1a), associated with systemic acquired resistance. Furthermore, WESMS also suppressed tomato wilt disease caused by R. solanacearum by 85% in seedlings and promoted growth (height, leaf number, and fresh weight of the root and shoot) of tomato plants. These findings suggest the WESMS of H. erinaceus has the potential to suppress bacterial wilt disease of tomato through multiple effects including antibacterial activity, plant growth promotion, and defense gene induction. PMID:26539048

  15. Water Extract from Spent Mushroom Substrate of Hericium erinaceus Suppresses Bacterial Wilt Disease of Tomato.

    PubMed

    Kwak, A Min; Min, Kyeong Jin; Lee, Sang Yeop; Kang, Hee Wan

    2015-09-01

    Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium carotovorum subsp. carotovorum, Agrobacterium tumefaciens, R. solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, X. axonopodis pv. vesicatoria, X. axonopodis pv. citiri, and X. axonopodis pv. glycine. Quantitative real-time PCR revealed that water extracts of SMS (WESMS) of H. erinaceus induced expressions of plant defense genes encoding β-1,3-glucanase (GluA) and pathogenesis-related protein-1a (PR-1a), associated with systemic acquired resistance. Furthermore, WESMS also suppressed tomato wilt disease caused by R. solanacearum by 85% in seedlings and promoted growth (height, leaf number, and fresh weight of the root and shoot) of tomato plants. These findings suggest the WESMS of H. erinaceus has the potential to suppress bacterial wilt disease of tomato through multiple effects including antibacterial activity, plant growth promotion, and defense gene induction. PMID:26539048

  16. Inflammatory bowel disease: an immunity-mediated condition triggered by bacterial infection with Helicobacter hepaticus.

    PubMed Central

    Cahill, R J; Foltz, C J; Fox, J G; Dangler, C A; Powrie, F; Schauer, D B

    1997-01-01

    Inflammatory bowel disease (IBD) is thought to result from either an abnormal immunological response to enteric flora or a normal immunological response to a specific pathogen. No study to date has combined both factors. The present studies were carried out with an immunologically manipulated mouse model of IBD. Mice homozygous for the severe combined immunodeficiency (scid) mutation develop IBD with adoptive transfer of CD4+ T cells expressing high levels of CD45RB (CD45RB(high) CD4+ T cells). These mice do not develop IBD in germfree conditions, implicating undefined intestinal flora in the pathogenesis of lesions. In controlled duplicate studies, the influence of a single murine pathogen, Helicobacter hepaticus, in combination with the abnormal immunological response on the development of IBD was assessed. The combination of H. hepaticus infection and CD45RB(high) CD4+ T-cell reconstitution resulted in severe disease expression similar to that observed in human IBD. This study demonstrates that IBD develops in mice as a consequence of an abnormal immune response in the presence of a single murine pathogen, H. hepaticus. The interaction of host immunity and a single pathogen in this murine system provides a novel model of human IBD, an immunity-mediated condition triggered by bacterial infection. PMID:9234764

  17. Prevalence and diagnosis of bacterial kidney disease (BKD) in Scotland between 1990 and 2002.

    PubMed

    Bruno, David W

    2004-05-01

    Bacterial kidney disease (BKD) is a notifiable disease for salmonids under United Kingdom and European Union legislation. Within the UK, legislation and the control of infected fish with BKD has been operating for 25 yr. Infection by the bacterium Renibacterium salmoninarum results in a chronic, debilitating infection and mortality. Records of BKD outbreaks and the detection of R. salmoninarum were monitored from 1990 through to 2002 for Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss reared in Scottish waters. The test methods included ELISA, culture and light microscopy. New outbreaks of BKD in salmon in seawater declined during this period, but with year-to-year variation. Only 1 record of BKD has occurred in freshwater-reared salmon (prevalence 1.04). BKD in farmed rainbow trout in seawater is uncommon and was only identified in 1993 and between 1998 and 2000. The number of active designated area orders (DAOs) for outbreaks in salmon has fallen since 1990, but has remained relatively constant for trout over the period of study. PMID:15212278

  18. Use of ELISA to monitor bacterial kidney disease in naturally spawning chinook salmon.

    PubMed

    O'Connor, Glenda; Hoffnagle, Timothy L

    2007-09-14

    Bacterial kidney disease (BKD) caused by Renibacterium salmoninarum (Rs) is a serious problem among Pacific Northwest salmon hatcheries and has raised concerns that salmon reared in hatcheries may spread BKD to natural populations. In order to monitor the potential spread of this disease to salmon spawning in nature, a method must be available to collect and analyze tissues from naturally spawning salmon. Kidney tissue analyzed by enzyme-linked immunosorbent assay (ELISA) is the standard method to detect the presence of Rs in salmon sampled in hatcheries. In this study, we tested the validity of using ELISA on kidney tissue collected from intact carcasses recovered on the spawning grounds to monitor BKD in naturally spawning populations by comparing ELISA optical density (OD) values from kidney tissue that was subjected to conditions that simulated decomposition in a carcass and collection during a spawning ground survey with samples freshly collected from salmon at a hatchery. Mean ELISA OD levels were 1.060 for the samples prepared by the normal preparation and 1.115 for samples prepared by simulating spawning ground survey collection. There was no significant difference in mean ELISA OD between the 2 sample preparations and the relationship did not significantly differ from 1:1 (slope = 0.946). This demonstrates that BKD prevalence in natural populations can be monitored using ELISA conducted on samples from intact carcasses recovered on spawning ground surveys. This will be an important tool for monitoring the effect of hatchery supplementation on naturally spawning salmon populations. PMID:17972755

  19. Preclinical testing of radiopharmaceuticals for novel applications in HIV, bacterial and fungal infectious diseases.

    PubMed

    Shah, M; Garg, G; Dadachova, E

    2015-09-01

    Antibiotics, antifungal and antiviral medications have traditionally been used in the management of infections. Due to widespread emergence of resistance to antimicrobial medications, and their side effects, there is a growing need for alternative approaches for management of such conditions. Antibiotic resistant bacterial pathogens are on the rise. A cure has not been achieved for viral infections like AIDS, while fungal and parasitic infections are constant threats to the health of general public. The incidence of opportunistic infections in immunocompromised individuals like HIV patients, patients receiving high dose steroids, chemotherapy patients, and organ transplant recipients is on the rise. Radioimmunotherapy (RIT) has the potential to be a suitable and viable therapeutic modality in the arena of infection management. Provided the target-associated antigen is expressed by the target cells and minimally or not expressed by other tissues, selective targeting of radiation to target sites can be theoretically accomplished with relative sparing normal tissues from radiation exposure. In our laboratory we successfully demonstrated the effectiveness of RIT for treating infectious diseases. We targeted murine cryptococcosis with a mAb to the Cryptococcus neoformans capsular glucuronoxylomannan labeled with Bismuth-213 ((213)Bi) or Rhenium-188 ((188)Re). We subsequently extended the applicability of RIT for treating bacterial and viral infections. One of the advantages of using RIT to treat infections as opposed to cancer is that, in contrast to tumor cells, cells expressing microbial antigens are antigenically very different from host tissues and thus provide the potential for exquisite specificity and low cross-reactivity. Ever increasing incidence of infectious pathologies, exhaustion of antimicrobial possibilities and rising drug resistance calls for use of alternative and novel therapeutic options and we believe RIT is the need of the hour to combat these

  20. Evidence and Role for Bacterial Mucin Degradation in Cystic Fibrosis Airway Disease

    PubMed Central

    Flynn, Jeffrey M.; Niccum, David; Dunitz, Jordan M.

    2016-01-01

    Chronic lung infections in cystic fibrosis (CF) patients are composed of complex microbial communities that incite persistent inflammation and airway damage. Despite the high density of bacteria that colonize the lower airways, nutrient sources that sustain bacterial growth in vivo, and how those nutrients are derived, are not well characterized. In this study, we examined the possibility that mucins serve as an important carbon reservoir for the CF lung microbiota. While Pseudomonas aeruginosa was unable to efficiently utilize mucins in isolation, we found that anaerobic, mucin-fermenting bacteria could stimulate the robust growth of CF pathogens when provided intact mucins as a sole carbon source. 16S rRNA sequencing and enrichment culturing of sputum also identified that mucin-degrading anaerobes are ubiquitous in the airways of CF patients. The collective fermentative metabolism of these mucin-degrading communities in vitro generated amino acids and short chain fatty acids (propionate and acetate) during growth on mucin, and the same metabolites were also found in abundance within expectorated sputum. The significance of these findings was supported by in vivo P. aeruginosa gene expression, which revealed a heightened expression of genes required for the catabolism of propionate. Given that propionate is exclusively derived from bacterial fermentation, these data provide evidence for an important role of mucin fermenting bacteria in the carbon flux of the lower airways. More specifically, microorganisms typically defined as commensals may contribute to airway disease by degrading mucins, in turn providing nutrients for pathogens otherwise unable to efficiently obtain carbon in the lung. PMID:27548479

  1. Evidence and Role for Bacterial Mucin Degradation in Cystic Fibrosis Airway Disease.

    PubMed

    Flynn, Jeffrey M; Niccum, David; Dunitz, Jordan M; Hunter, Ryan C

    2016-08-01

    Chronic lung infections in cystic fibrosis (CF) patients are composed of complex microbial communities that incite persistent inflammation and airway damage. Despite the high density of bacteria that colonize the lower airways, nutrient sources that sustain bacterial growth in vivo, and how those nutrients are derived, are not well characterized. In this study, we examined the possibility that mucins serve as an important carbon reservoir for the CF lung microbiota. While Pseudomonas aeruginosa was unable to efficiently utilize mucins in isolation, we found that anaerobic, mucin-fermenting bacteria could stimulate the robust growth of CF pathogens when provided intact mucins as a sole carbon source. 16S rRNA sequencing and enrichment culturing of sputum also identified that mucin-degrading anaerobes are ubiquitous in the airways of CF patients. The collective fermentative metabolism of these mucin-degrading communities in vitro generated amino acids and short chain fatty acids (propionate and acetate) during growth on mucin, and the same metabolites were also found in abundance within expectorated sputum. The significance of these findings was supported by in vivo P. aeruginosa gene expression, which revealed a heightened expression of genes required for the catabolism of propionate. Given that propionate is exclusively derived from bacterial fermentation, these data provide evidence for an important role of mucin fermenting bacteria in the carbon flux of the lower airways. More specifically, microorganisms typically defined as commensals may contribute to airway disease by degrading mucins, in turn providing nutrients for pathogens otherwise unable to efficiently obtain carbon in the lung. PMID:27548479

  2. [Experience of using bacteriophages and bitsillin-5 to reduce the incidence of respiratory diseases of bacterial ethiology in military personnel].

    PubMed

    Akimkin, V G; Kalmykov, A A; Aminev, R M; Polyakov, V S; Artebyakin, S V

    2016-02-01

    The authors defined epidemiological efficacy and safety of the use of bacteriophages(streptococcal, staphylococcal, piobakferiophage multipartial) and bitsillin-5 to reduce tonsillitis morbidityand other respiratory diseases with bacterial etiology in groups of servicemen during their formationagainst increase of seasonal morbidity. The results of the use of these preventive agents were evaluatedby a comparative analysis of this disease in experimental and control groups. In total 510 healthy conscriptswere involved into the study. The effectiveness of prophylactic use of bacteriophages and bitsillin-5, whichprovided a reduction in the incidence of respiratory infections of bacterial ethiology, tonsillitis, and otherrespiratory diseases is showed. Recommendations on the choice of drugsfor the prevention of these infections,methods and organization of their application in organized groups are given. PMID:27263210

  3. Observations on the foliar nematode, Aphelenchoides besseyi, infecting tuberose and rice in India

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The foliar nematode Aphelenchoides besseyi causes white tip disease in rice (Oryza sativa L.) and floral malady in tuberose (Polianthes tuberosa L.). This nematode is widely distributed in the rice fields of many states of India, including West Bengal (WB), Andhra Pradesh (AP), Madhya Pradesh (MP) a...

  4. A rapidly progressing, deadly disease of Actias selene (Indianmoonmoth) larvae associated with a mixed bacterial and baculoviral infection.

    PubMed

    Skowron, Marta A; Guzow-Krzemińska, Beata; Barańska, Sylwia; Jędrak, Paulina; Węgrzyn, Grzegorz

    2015-09-01

    The outbreak of an infectious disease in captive-bred Lepidoptera can cause death of all the caterpillars within days. A mixed baculoviral-bacterial infection observed among Actias selene (Hubner 1807), the Indian moon moth (Insecta: Lepidoptera: Saturniidae), larvae was characterized and followed by a photographic documentation of the disease progression. The etiological agents were determined using mass spectrometry and polymerase chain reaction (PCR). It appeared that the disease was caused by a mixed infection of larvae with a baculovirus and Morganella morganii. A molecular phylogenetic analysis of the virus and microbiological description of the pathogenic bacterium are presented. PMID:26333395

  5. Onchocerciasis: the Role of Wolbachia Bacterial Endosymbionts in Parasite Biology, Disease Pathogenesis, and Treatment

    PubMed Central

    Tamarozzi, Francesca; Halliday, Alice; Gentil, Katrin; Hoerauf, Achim; Pearlman, Eric; Taylor, Mark J.

    2011-01-01

    Summary: The discovery of Wolbachia intracellular bacteria within filarial nematodes, including Onchocerca volvulus, the causative agent of onchocerciasis or “river blindness,” has delivered a paradigm shift in our understanding of the parasite's biology, to where we now know that the bacterial endosymbionts are essential for normal development of larvae and embryos and may support the long-term survival of adult worms. The apparent mutualistic dependency has also offered a novel approach to the treatment of onchocerciasis through the use of antibiotics to eliminate Wolbachia, delivering for the first time a treatment which has significant macrofilaricidal efficacy. Studies with other filarial nematode species have also highlighted a role for Wolbachia in transmission and infection of the mammalian host through a fascinating manipulation of mast cell-mediated vasodilation to enhance infectivity of vector-borne larvae. Wolbachia has also been identified as the principal driver of innate and adaptive Th1 inflammatory immunity, which can either contribute to disease pathogenesis or, with the Wolbachia-mediated recruitment of mast cells, enhance infectivity. The Wolbachia activation of innate inflammation also drives inflammatory adverse events in response to chemotherapy with either diethylcarbamazine (DEC) or ivermectin. In this review we summarize the experimental and field trial data which have uncovered the importance of Wolbachia symbiosis in onchocerciasis. PMID:21734243

  6. Diagnosis of bacterial kidney disease by detection of Renibacterium salmoninarum by real-time PCR.

    PubMed

    Jansson, E; Lindberg, L; Säker, E; Aspán, A

    2008-10-01

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum (Rs), is a serious threat to salmon in aquaculture as well as to wild populations. We have developed a real-time polymerase chain reaction (PCR) for detection of Rs in kidney samples. The PCR is based on detection of unique parts of the 16S rRNA gene of Rs and DNA equivalent to 1-10 Rs genomes was detected per reaction. No cross-reactivity with other fish pathogenic or related bacteria could be demonstrated. Analysis of individual kidney samples collected from BKD classified populations identified 39.9% of the fish as positive by real-time PCR compared with 28.0% by polyclonal enzyme-linked immunosorbent assay (ELISA). The real-time PCR assay was found to be well suited for complementary use with ELISA for diagnosis of BKD, with the ability to detect clinical as well as covert Rs infections. The infection level determined by the polyclonal ELISA and by real-time PCR was significantly correlated. PMID:18681904

  7. Bacterial invasion in root cementum and radicular dentin of periodontally diseased teeth in humans. A reservoir of periodontopathic bacteria.

    PubMed

    Adriaens, P A; De Boever, J A; Loesche, W J

    1988-04-01

    In this study the viability and the distribution of bacteria within the radicular dentin and pulp of periodontally diseased caries-free teeth were studied. Healthy teeth served as controls. Samples were obtained from the pulp tissue and from the radicular dentin. Dentin samples were taken from the interdental surfaces in the subgingival area. Starting from the pulpal side, three to five successive dentin layers of approximately 1 mm thickness were sampled. The samples were processed and cultured using an anaerobic technique. Bacterial growth was detected in 87% of the periodontally diseased teeth. In 83% of the teeth, bacteria were present in at least one of the dentin layers. Fifty-nine percent of the diseased teeth, from which the pulp tissue was cultured, contained bacteria in the pulp samples. The mean bacterial concentrations in the pulp and dentin layers ranged from 1,399 to 16,537 colony-forming units (CFU) per mg of tissue. These concentrations were 259 to 7,190 times greater than concentrations found in healthy teeth. It is suggested that the roots of periodontally diseased teeth could act as bacterial reservoirs from which recolonization of mechanically treated root surfaces can occur, as well as infection of the dental pulp. These findings might change current concepts concerning root surface debridement in periodontal therapy. PMID:3164373

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

    PubMed

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA) pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods. PMID:25565273

  9. Yeast Cell Wall Extract Induces Disease Resistance against Bacterial and Fungal Pathogens in Arabidopsis thaliana and Brassica Crop

    PubMed Central

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA) pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods. PMID:25565273

  10. Development of a Vaccine for Bacterial Kidney Disease in Salmon, 1988 Final Report.

    SciTech Connect

    Kaattari, Stephen L.

    1989-08-01

    Bacterial kidney disease of salmonids is a very complex disease which appears to exploit a variety of pathogenic mechanisms. An understanding of these mechanisms is essential to the development of efficacious vaccines. It has become well established from the studies published .in this report and those of others that soluble antigens which are secreted by Renibacterium salmoninarum have toxigenic potential. If they are found to be responsible for mortality, the development of toxoid(s) could be paramount to the production of a vaccine. One must, however, be circumspect in producing a vaccine. A thorough knowledge, not only of the pathogen, but also of the immune system of the host is an absolute requirement. This becomes of particular importance when dealing with fish diseases, since the field of fish immunology is still within its infancy. This lack of knowledge is particularly felt when the induction of a prophylactic immune response concomitantly leads to pathological side effects which may be as destructive as the original infection. Indeed, it appears that some aspects of BKD may be due to the induction of hypersensitivity reactions. If such immunopathologies are expressed, it is prudent to thoroughly evaluate the nature of the immunoprophylaxis to insure that these harmful sequelae do not occur. Evaluation of a variety of antigens, adjuvants, immune responses, and survival data leads us to recommend that attempts at prophylaxis against BKD should center upon the elicitation of cellular immunity utilizing preparations of Mycobacterium chelonii. The choice of this species of mycobacteria was made because of its effectiveness, ease of maintenance and production, and the lack of need for its propagation within containment facilities. These assets are important to consider if large scale vaccine production is to be profitable. As can be seen from the data provided, M. chelonii alone is capable of producing prophylaxis to BKD, however, this is likely due to the

  11. Salivary bacterial fingerprints of established oral disease revealed by the Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS) technique

    PubMed Central

    Belstrøm, Daniel; Paster, Bruce J.; Fiehn, Nils-Erik; Bardow, Allan; Holmstrup, Palle

    2016-01-01

    Background and objective The composition of the salivary microbiota, as determined using various molecular methods, has been reported to differentiate oral health from diseases. Thus, the purpose of this study was to utilize the newly developed molecular technique HOMINGS (Human Oral Microbe Identification using Next Generation Sequencing) for comparison of the salivary microbiota in patients with periodontitis, patients with dental caries, and orally healthy individuals. The hypothesis was that this method could add on to the existing knowledge on salivary bacterial profiles in oral health and disease. Design Stimulated saliva samples (n=30) were collected from 10 patients with untreated periodontitis, 10 patients with untreated dental caries, and 10 orally healthy individuals. Salivary microbiota was analyzed using HOMINGS and statistical analysis was performed using Kruskal–Wallis test with Benjamini–Hochberg's correction. Results From a total of 30 saliva samples, a mean number of probe targets of 205 (range 120–353) were identified, and a statistically significant higher mean number of targets was registered in samples from patients with periodontitis (mean 220, range 143–306) and dental caries (mean 221, range 165–353) as compared to orally healthy individuals (mean 174, range 120–260) (p=0.04 and p=0.04). Nine probe targets were identified with a different relative abundance between groups (p<0.05). Conclusions Cross-sectional comparison of salivary bacterial profiles by means of HOMINGS analysis showed that different salivary bacterial profiles were associated with oral health and disease. Future large-scale prospective studies are needed to evaluate if saliva-based screening for disease-associated oral bacterial profiles may be used for identification of patients at risk of acquiring periodontitis and dental caries. PMID:26782357

  12. Hyperspectral remote sensing of foliar nitrogen content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A strong positive correlation between vegetation canopy Bidirectional Reflectance Factor (BRF) in the Near'InfraRed (NIR) spectral region and foliar mass-based nitrogen concentration (%N) has been reported in some temperate and boreal forests. This relationship, if true, would indicate an additional...

  13. Foliar Nitrogen Fertilization for Perennial Nursery Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) availability affects plant growth and development and is intimately linked to the quality of nursery plants. In nursery production, N is commonly applied to the soil as controlled release and/or liquid fertilizers. However, research has shown that combining foliar N fertilization with a...

  14. Disease-reducing effect of Chromolaena odorata extract on sheath blight and other rice diseases.

    PubMed

    Khoa, Nguyen Đac; Thuy, Phan Thi Hong; Thuy, Tran Thi Thu; Collinge, David B; Jørgensen, Hans Jørgen Lyngs

    2011-02-01

    Sheath blight caused by Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) is a major cause of crop loss in intensive rice production systems. No economically viable control methods have been developed. We screened aqueous extracts of common herbal plants that could reduce sheath blight lesions and found that foliar spraying and seed soaking application of extracts of either fresh or dried leaves of Chromolaena odorata gave up to 68% reduction in sheath blight lesion lengths under controlled and semi-field conditions. The observed reductions were not dependent on growth conditions of C. odorata and rice cultivar. The effect was observed until 21 days after inoculation and was not dependent on microbial activity. Under semi-field conditions, extracts also reduced severity of other important rice diseases, i.e., blast (Pyricularia oryzae) using foliar spray (up to 45%), brown spot (Bipolaris oryzae) using seed treatment (up to 57%), and bacterial blight (Xanthomonas oryzae pv. oryzae) using both application methods (up to 50%). PMID:20839964

  15. Intestinal Dysbiosis and Bacterial Enteroinvasion in a Murine Model of Hirschsprung’s Disease

    PubMed Central

    Pierre, Joseph F.; Barlow-Anacker, Amanda J.; Erickson, Christopher S.; Heneghan, Aaron F.; Leverson, Glen E.; Dowd, Scot E.; Epstein, Miles L.; Kudsk, Kenneth A.; Gosain, Ankush

    2014-01-01

    Background/Purpose Hirschsprung’s disease (HSCR), characterized by the absence of ganglia in the distal colon, results in functional obstruction. Despite surgical resection of the aganglionic segment, around 40% of patients suffer recurrent life threatening Hirschsprung’s-associated enterocolitis (HAEC). The aim of this study was to investigate whether gut microbiota and intestinal immunity changes contribute to the HAEC risk in a HSCR model. Methods Mice with neural crest conditional deletion of Endothelin receptor B (EdnrB) and their littermate controls were used (EdnrB-null and EdnrB-het). Bacterial DNA was prepared from cecal contents of P16–18 and P21–24 animals and pyrosequencing employed for microbiome analysis. Ileal tissue was isolated and secretory phospholipase A2 (sPLA2) expression and activity determined. Enteroinvasion of E. coli into ileal explants was measured using an ex vivo organ culture system. Results EdnrB-het and EdnrB-nulls displayed similar flora, sPLA2 expression and activity at P16–18. However, by P21–24, EdnrB-hets demonstrated increased Lactobacillus and decreased Bacteroides and Clostridium, while EdnrB-nulls exhibited reciprocal changes. EdnrB-nulls also showed reduced sPLA2 expression and luminal activity at this stage. Functionally, EdnrB-nulls were more susceptible to enteroinvasion with E. coli ex vivo and released less sPLA2 than EdnrB-hets. Conclusions Initially, EdnrB-het and EdnrB-nulls contain similar cecal flora but then undergo reciprocal changes. EdnrB-nulls display dysbiosis, demonstrate impaired mucosal defense, decreased luminal sPLA2 and increased enteroinvasion of E. coli just prior to robust colonic inflammation and death. These findings suggest a role for the intestinal microbiome in the development of HAEC. PMID:25092084

  16. Reactive oxygen species in peripheral blood and sputum neutrophils during bacterial and nonbacterial acute exacerbation of chronic obstructive pulmonary disease.

    PubMed

    Vaitkus, Mindaugas; Lavinskiene, Simona; Barkauskiene, Diana; Bieksiene, Kristina; Jeroch, Jolanta; Sakalauskas, Raimundas

    2013-12-01

    Chronic airway inflammation can be mediated by an enhanced neutrophil oxidative burst. However, the role of bacteria in the pathogenesis of chronic obstructive pulmonary disease (COPD) exacerbations is highly controversial. The aim of this study was to evaluate the production of reactive oxygen species (ROS) in peripheral blood and sputum neutrophils during bacterial and nonbacterial acute exacerbations of COPD (AECOPD). A total of 40 patients with AECOPD, 10 healthy nonsmokers, and 10 "healthy" smokers were enrolled into the study. Peripheral blood and sputum samples were obtained during exacerbation and after recovery. Neutrophils were isolated by high-density gradient centrifugation and magnetic separation. ROS production by neutrophils was investigated after stimulation with phorbol-myristate-acetate and Staphylococcus aureus bacteria. ROS production by neutrophils was assessed as the mean fluorescent intensity using a flow cytometer. IL-8 levels in serum and induced sputum were determinant by ELISA. Spontaneous ROS production was significantly higher in neutrophils from the patients with bacterial AECOPD as compared with nonbacterial AECOPD and stable COPD (P <0.05). ROS production stimulated with PMA and with Staphylococcus aureus was significantly higher in neutrophils isolated from the patients with bacterial AECOPD as compared with nonbacterial and stable COPD (P <0.05). The serum and induced sputum IL-8 levels were significantly increased in the patients with bacterial AECOPD than nonbacterial AECOPD, stable COPS, and "healthy" smokers and nonsmokers (P <0.05) and higher in the induced sputum as the compared with serum in all studied groups (P <0.05). Enlarge CRP level was documented during AECOPD than in all other groups (P <0.05). A markedly increased ROS production in sputum neutrophils during bacterial AECOPD shows an inflammatory response reflecting enhanced local inflammation, which can be mediated by bacterial colonization. PMID:23872721

  17. Hyperspectral Remote Sensing of Foliar Nitrogen Content

    NASA Technical Reports Server (NTRS)

    Knyazikhin, Yuri; Schull, Mitchell A.; Stenberg, Pauline; Moettus, Matti; Rautiainen, Miina; Yang, Yan; Marshak, Alexander; Carmona, Pedro Latorre; Kaufmann, Robert K.; Lewis, Philip; Disney, Mathias I.; Vanderbilt, Vern; Davis, Anthony B.; Baret, Frederic; Jacquemoud, Stephane; Lyapustin, Alexei; Myneni, Ranga B.

    2013-01-01

    A strong positive correlation between vegetation canopy bidirectional reflectance factor (BRF) in the near infrared (NIR) spectral region and foliar mass-based nitrogen concentration (%N) has been reported in some temperate and boreal forests. This relationship, if true, would indicate an additional role for nitrogen in the climate system via its influence on surface albedo and may offer a simple approach for monitoring foliar nitrogen using satellite data. We report, however, that the previously reported correlation is an artifact - it is a consequence of variations in canopy structure, rather than of %N. The data underlying this relationship were collected at sites with varying proportions of foliar nitrogen-poor needleleaf and nitrogen-rich broadleaf species, whose canopy structure differs considerably. When the BRF data are corrected for canopy-structure effects, the residual reflectance variations are negatively related to %N at all wavelengths in the interval 423-855 nm. This suggests that the observed positive correlation between BRF and %N conveys no information about %N. We find that to infer leaf biochemical constituents, e.g., N content, from remotely sensed data, BRF spectra in the interval 710-790 nm provide critical information for correction of structural influences. Our analysis also suggests that surface characteristics of leaves impact remote sensing of its internal constituents. This further decreases the ability to remotely sense canopy foliar nitrogen. Finally, the analysis presented here is generic to the problem of remote sensing of leaf-tissue constituents and is therefore not a specific critique of articles espousing remote sensing of foliar %N.

  18. Hyperspectral remote sensing of foliar nitrogen content.

    PubMed

    Knyazikhin, Yuri; Schull, Mitchell A; Stenberg, Pauline; Mõttus, Matti; Rautiainen, Miina; Yang, Yan; Marshak, Alexander; Latorre Carmona, Pedro; Kaufmann, Robert K; Lewis, Philip; Disney, Mathias I; Vanderbilt, Vern; Davis, Anthony B; Baret, Frédéric; Jacquemoud, Stéphane; Lyapustin, Alexei; Myneni, Ranga B

    2013-01-15

    A strong positive correlation between vegetation canopy bidirectional reflectance factor (BRF) in the near infrared (NIR) spectral region and foliar mass-based nitrogen concentration (%N) has been reported in some temperate and boreal forests. This relationship, if true, would indicate an additional role for nitrogen in the climate system via its influence on surface albedo and may offer a simple approach for monitoring foliar nitrogen using satellite data. We report, however, that the previously reported correlation is an artifact--it is a consequence of variations in canopy structure, rather than of %N. The data underlying this relationship were collected at sites with varying proportions of foliar nitrogen-poor needleleaf and nitrogen-rich broadleaf species, whose canopy structure differs considerably. When the BRF data are corrected for canopy-structure effects, the residual reflectance variations are negatively related to %N at all wavelengths in the interval 423-855 nm. This suggests that the observed positive correlation between BRF and %N conveys no information about %N. We find that to infer leaf biochemical constituents, e.g., N content, from remotely sensed data, BRF spectra in the interval 710-790 nm provide critical information for correction of structural influences. Our analysis also suggests that surface characteristics of leaves impact remote sensing of its internal constituents. This further decreases the ability to remotely sense canopy foliar nitrogen. Finally, the analysis presented here is generic to the problem of remote sensing of leaf-tissue constituents and is therefore not a specific critique of articles espousing remote sensing of foliar %N. PMID:23213258

  19. PARTITIONING THE RELATIVE INFLUENCE OF SOIL N, MYCORRHIZAE, AND FOLIAR N UPTAKE ON FOLIAR δ15N PATTERNS: CAN WE DETECT FOLIAR UPTAKE OF REACTIVE N?

    NASA Astrophysics Data System (ADS)

    Vallano, D.; Sparks, J. P.

    2009-12-01

    Vegetation is an important sink for atmospheric reactive N in N-limited systems and may be capable of incorporating reactive N compounds directly into leaves through the foliar uptake pathway. A proxy for atmospheric reactive N entering vegetation would be useful to estimate the impact of direct foliar N uptake on plant metabolism. Natural abundance foliar N isotopic composition (δ15N) is a practical tool for this purpose because plant-available N sources often have different isotopic compositions. Current understanding of foliar δ15N suggests these values primarily represent the integration of soil δ15N, direct foliar N uptake, mycorrhizal fractionation, and within-plant fractionations. Using a potted plant mesocosm system, we estimated the influence of mycorrhizae on foliar δ15N patterns in red maple (Acer rubrum) seedlings along an N deposition gradient in New York State. We found that mycorrhizal associations altered foliar δ15N in red maple seedlings from 0.03 - 1.01‰ across sites. Along the same temporal and spatial scales, we examined the influence of soil δ15N, foliar N uptake, and mycorrhizae on foliar δ15N in adult stands of American beech (Fagus grandifolia), black birch (Betula lenta), red maple (A. rubrum), and red oak (Quercus rubra). Using multiple regression models, atmospheric NO2 concentration explained 0%, 69%, 23%, and 45% of the residual variation in foliar δ15N remaining in American beech, red maple, red oak, and black birch, respectively, after accounting for soil δ15N. Our results suggest that foliar δ15N may be used to estimate pollution-derived atmospheric reactive N entering vegetation via the foliar N uptake pathway.

  20. Practical benefits of knowing the enemy: Modern molecular tools for diagnosing the etiology of bacterial diseases and understanding the taxonomy and diversity of plant pathogenic bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowing the identity of bacterial plant pathogens is essential to strategic and sustainable disease management. However, such identifications are linked to bacterial taxonomy, a complicated and changing discipline that depends on methods and information that often are not used by those who are diagn...

  1. Rainbow trout (Oncorhynchus mykiss) resistance to columnaris disease is heritable and favorably correlated with bacterial cold water disease resistance.

    PubMed

    Evenhuis, J P; Leeds, T D; Marancik, D P; LaPatra, S E; Wiens, G D

    2015-04-01

    Columnaris disease (CD), caused by Flavobacterium columnare, is an emerging disease affecting rainbow trout aquaculture. Objectives of this study were to 1) estimate heritability of CD resistance in a rainbow trout line (ARS-Fp-R) previously selected 4 generations for improved bacterial cold water disease (BCWD) resistance; 2) estimate genetic correlations among CD resistance, BCWD resistance, and growth to market BW; and 3) compare CD resistance among the ARS-Fp-R, ARS-Fp-S (selected 1 generation for increased BCWD susceptibility), and ARS-Fp-C (selection control) lines. Heritability of CD resistance was estimated using data from a waterborne challenge of 44 full-sib ARS-Fp-R families produced using a paternal half-sib mating design, and genetic correlations were estimated using these data and 5 generations of BCWD resistance, 9-mo BW (approximately 0.5 kg), and 12-mo BW (approximately 1.0 kg) data from 405 ARS-Fp-R full-sib families. The CD and BCWD challenges were initiated at approximately 52 and 84 d posthatch, or approximately 650 and 1,050 degree days (°C × d), respectively. Survival of ARS-Fp-R families ranged from 0 to 48% following CD challenge and heritability estimates were similar between CD (0.17 ± 0.09) and BCWD (0.18 ± 0.03) resistance, and the genetic correlation between these 2 traits was favorable (0.35 ± 0.25). Genetic correlations were small and antagonistic (-0.15 ± 0.08 to -0.19 ± 0.24) between the 2 resistance traits and 9- and 12-mo BW. Two challenges were conducted in consecutive years to compare CD resistance among ARS-Fp-R, ARS-Fp-C, and ARS-Fp-S families. In the first challenge, ARS-Fp-R families (83% survival) had greater CD resistance than ARS-Fp-C (73.5%; P = 0.02) and ARS-Fp-S (68%; P < 0.001) families, which did not differ (P = 0.16). In the second challenge, using an approximately 2.5-fold greater challenge dose, ARS-Fp-R families exhibited greater CD resistance (56% survival) than ARS-Fp-S (38% survival; P = 0.02) families

  2. Characterization of the bacterial communities associated with the bald sea urchin disease of the echinoid Paracentrotus lividus.

    PubMed

    Becker, Pierre T; Egea, Emilie; Eeckhaut, Igor

    2008-06-01

    The microbial communities involved in the bald sea urchin disease of the echinoid Paracentrotus lividus are investigated using culture-independent techniques. Lesions of diseased specimens from two locations in France, La Ciotat (Mediterranean Sea) and Morgat (Atlantic Ocean), are examined by Scanning Electron Microscopy (SEM) and the diversity of their microbiota is analysed by Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rRNA gene clones libraries construction. Microscopic observations demonstrated that only the central area of the lesions is invaded by bacteria but not the peripheral zone and the surrounding healthy tissues. Molecular analysis identified at least 24 bacterial genomospecies in bald sea urchin lesions: 5 are Alphaproteobacteria, 10 are Gammaproteobacteria, 8 are CFB bacteria and 1 is a Fusobacteria. Out of them, 4 are observed in both locations while 10 occur only in the Atlantic Ocean and 10 only in the Mediterranean Sea. Gammaproteobacteria are the most represented in clones libraries from both locations, with respectively 65% and 43% of the total clones. CFB and Alphaproteobacteria accounted for the majority of the remaining clones and were detected by DGGE in virtually all samples from both stations. Our results demonstrate that bacterial communities observed on diseased individuals of the same echinoid species but originating from distinct locations are not similar and thus support the hypothesis that bacteria involved in the worldwide echinoid disease commonly called the bald sea urchin disease are opportunistic and not specific. PMID:18191940

  3. Foliar pathogenesis and plant water relations: a review.

    PubMed

    Grimmer, Michael K; John Foulkes, M; Paveley, Neil D

    2012-07-01

    As the world population grows, there is a pressing need to improve productivity from water use in irrigated and rain-fed agriculture. Foliar diseases have been reported to decrease crop water-use efficiency (WUE) substantially, yet the effects of plant pathogens are seldom considered when methods to improve WUE are debated. We review the effects of foliar pathogens on plant water relations and the consequences for WUE. The effects reported vary between host and pathogen species and between host genotypes. Some general patterns emerge however. Higher fungi and oomycetes cause physical disruption to the cuticle and stomata, and also cause impairment of stomatal closing in the dark. Higher fungi and viruses are associated with impairment of stomatal opening in the light. A number of toxins produced by bacteria and higher fungi have been identified that impair stomatal function. Deleterious effects are not limited to compatible plant-pathogen interactions. Resistant and non-host interactions have been shown to result in stomatal impairment in light and dark conditions. Mitigation of these effects through selection of favourable resistance responses could be an important breeding target in the future. The challenges for researchers are to understand how the effects reported from work under controlled conditions translate to crops in the field, and to elucidate underlying mechanisms. PMID:22664583

  4. Interaction of common bacterial blight bacteria with disease resistance quantitative trait loci in common bean.

    PubMed

    Duncan, Robert W; Singh, Shree P; Gilbertson, Robert L

    2011-04-01

    Common bacterial blight (CBB) of common bean (Phaseolus vulgaris L.) is caused by Xanthomonas campestris pv. phaseoli and X. fuscans subsp. fuscans, and is the most important bacterial disease of this crop in many regions of the world. In 2005 and 2006, dark red kidney bean fields in a major bean-growing region in central Wisconsin were surveyed for CBB incidence and representative symptomatic leaves collected. Xanthomonad-like bacteria were isolated from these leaves and characterized based upon phenotypic (colony) characteristics, pathogenicity on common bean, polymerase chain reaction (PCR) with X. campestris pv. phaseoli- and X. fuscans subsp. fuscans-specific primers, and repetitive-element PCR (rep-PCR) and 16S-28S ribosomal RNA spacer region sequence analyses. Of 348 isolates that were characterized, 293 were identified as common blight bacteria (i.e., pathogenic on common bean and positive in PCR tests with the X. campestris pv. phaseoli- and X. fuscans subsp. fuscans-specific primers), whereas the other isolates were nonpathogenic xanthomonads. Most (98%) of the pathogenic xanthomonads were X. campestris pv. phaseoli, consistent with the association of this bacterium with CBB in large-seeded bean cultivars of the Andean gene pool. Two types of X. campestris pv. phaseoli were involved with CBB in this region: typical X. campestris pv. phaseoli (P) isolates with yellow mucoid colonies, no brown pigment production, and a typical X. campestris pv. phaseoli rep-PCR fingerprint (60% of strains); and a new phenotype and genotype (Px) with an X. campestris pv. phaseoli-type fingerprint and less mucoid colonies that produced brown pigment (40% of strains). In addition, a small number of X. fuscans subsp. fuscans strains, representing a new genotype (FH), were isolated from two fields in 2005. Representative P and Px X. campestris pv. phaseoli strains, an FH X. fuscans subsp. fuscans strain, plus five previously characterized X. campestris pv. phaseoli and X

  5. Detection and validation of QTL affecting bacterial cold water disease resistance in rainbow trout using restriction-site associated DNA sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. Using microsatellites genome scan we have previously detected significant and suggestive QTL with major effects on the phenotypic variation of survival following challenge with Flavobacterium psychrophilum...

  6. Detection and validation of QTL affecting Bacterial Cold Water Disease resistance in rainbow trout using restriction-site associated DNA Sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. Using microsatellites genome scan we have previously detected significant and suggestive QTL with major effects on the phenotypic variation of survival following challenge with Flavobacterium psychrophilum...

  7. Foliar application of biofilm formation-inhibiting compounds enhances control of citrus canker caused by Xanthomonas citri subsp. citri.

    PubMed

    Li, Jinyun; Wang, Nian

    2014-02-01

    Citrus canker caused by the bacterium Xanthomonas citri subsp. citri is an economically important disease of citrus worldwide. Biofilm formation plays an important role in early infection of X. citri subsp. citri on host leaves. In this study, we assessed the hypothesis that small molecules inhibiting biofilm formation reduce X. citri subsp. citri infection and enhance the control of citrus canker disease. D-leucine and 3-indolylacetonitrile (IAN) were found to prevent biofilm formation by X. citri subsp. citri on different abiotic surfaces and host leaves at a concentration lower than the minimum inhibitory concentration (MIC). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis indicated that IAN repressed expression of chemotaxis/motility-related genes in X. citri subsp. citri. In laboratory experiments, planktonic and biofilm cells of X. citri subsp. citri treated with D-leucine and IAN, either alone or in combination, were more susceptible to copper (CuSO4) than those untreated. In greenhouse assays, D-leucine and IAN applied alone or combined with copper reduced both the number of canker lesions and bacterial populations of X. citri subsp. citri on citrus host leaves. This study provides the basis for the use of foliar-applied biofilm inhibitors for the control of citrus canker alone or combined with copper-based bactericides. PMID:23901828

  8. Nontarget effects of foliar fungicide application on the rhizosphere: diversity of nifH gene and nodulation in chickpea field

    PubMed Central

    Yang, C; Hamel, C; Vujanovic, V; Gan, Y

    2012-01-01

    Aims This study explores nontarget effects of fungicide application on field-grown chickpea. Methods and Results Molecular methods were used to test the effects of foliar application of fungicide on the diversity and distribution of nifH genes associated with two chickpea cultivars and their nodulation. Treatments were replicated four times in a split-plot design in the field, in 2008 and 2009. Chemical disease control did not change the richness of the nifH genes associated with chickpea, but selected different dominant nifH gene sequences in 2008, as revealed by correspondence analysis. Disease control strategies had no significant effect on disease severity or nifH gene distribution in 2009. Dry weather conditions rather than disease restricted plant growth that year, suggesting that reduced infection rather than the fungicide is the factor modifying the distribution of nifH gene in chickpea rhizosphere. Reduced nodule size and enhanced N2-fixation in protected plants indicate that disease control affects plant physiology, which may in turn influence rhizosphere bacteria. The genotypes of chickpea also affected the diversity of the nifH gene in the rhizosphere, illustrating the importance of plant selective effects on bacterial communities. Conclusions We conclude that the chemical disease control affects nodulation and the diversity of nifH gene in chickpea rhizosphere, by modifying host plant physiology. A direct effect of fungicide on the bacteria cannot be ruled out, however, as residual amounts of fungicide were found to accumulate in the rhizosphere soil of protected plants. Significance and Impact of the Study Systemic nontarget effect of phytoprotection on nifH gene diversity in chickpea rhizosphere is reported for the first time. This result suggests the possibility of manipulating associative biological nitrogen fixation in the field. PMID:22335393

  9. First Report of Bacterial Wilt Caused by Ralstonia solanacearum Biovar 2 Race 1 on Tomato in Egypt

    PubMed Central

    Seleim, Mohamed A. A.; Abo-Elyousr, Kamal A. M.; Abd-El-Moneem, Kenawy M.; Saead, Farag A.

    2014-01-01

    This study aims to isolate and identify the causal pathogen of tomato bacterial wilt in Egypt. In 2008, tomato plants showing typical symptoms of bacterial wilt disease with no foliar yellowing were observed in Minia, Assiut and Sohag governorates, Egypt. When cut stems of symptomatic plants were submerged in water, whitish ooze was evident and longitudinal sections showed a brown discoloration in the vascular tissues. Bacteria were isolated on triphenyl tetrazolium chloride medium and fifteen isolates shown typical morphological and cultural characteristics were confirmed as Ralstonia solanacearum biovar 2 race 1. Pathogenicity tests showed that all isolates proved to be pathogenic to tomato plants, varied from 52 to 97% wilting. This is the first report of R. solanacearum biovar 2 race 1 causing bacterial wilt in tomato crop in Egypt. PMID:25289016

  10. A review of infectious bovine rhinotracheitis, shipping fever pneumonia and viral-bacterial synergism in respiratory disease of cattle.

    PubMed Central

    Yates, W D

    1982-01-01

    Unanswered questions on the etiology and prevention of shipping fever pneumonia have allowed this disease to remain one of the most costly to the North American cattle industry. Research in this area has indirected that while Pasteurella haemolytica and, to a lesser extent, P. multocida are involved in most cases, they seem to require additional factors to help initiate the disease process. Bovine herpes virus 1 has been shown experimentally to be one such factor. This review examines in some detail the topics of infectious bovine rhinotracheitis, shipping fever, and viral-bacterial interactions in the production of respiratory disease in various species. It deals with history, definitions, etiologies, clinical signs and lesions, and considers exposure levels, transmission and various pathogenetic mechanisms that are postulated or known to occur. PMID:6290011

  11. Foliar penetration enhanced by biosurfactant rhamnolipid.

    PubMed

    Liu, Haojing; Shao, Bing; Long, Xuwei; Yao, Yang; Meng, Qin

    2016-09-01

    With recent environmental and health concerns, biosurfactants have obtained increasing interest in replacing conventional surfactants for diverse applications. In agriculture, the use of surfactant in stimulating foliar uptake is mainly for wetting leaf surface, resisting deposition/evaporation, enhancing penetration across cuticular membrane (CM) and translocation. This paper aimed to address the improved foliar uptake by rhamnolipid (RL) in comparison with the currently used alkyl polyglucoside (APG). As found, compared with APG at 900mg/L (1×critical micellar concentration, CMC), RL at a much lower concentration of 50mg/L (1×CMC) showed much better wettability and surface activity, indicative of its high effectiveness as surfactants. Its performance on resistance to deposition and evaporation was at least as same as APG. Moreover, RL could significantly improve the penetration of herbicide glyphosate and other two small water-soluble molecules (phenol red and Fe(2+)) across CM at an equivalent efficiency as APG at 1×CMC. Finally, the greatly enhanced herbicidal actitivity of glyphosate on greenhouse plants confirmed that RL and APG could both enhance the foliar uptake including translocation. Overall, RL should be more applicable than APG in agriculture due to its more promising properties on health/environmental friendliness. PMID:27281240

  12. Testing Taxonomic Predictivity of Foliar and Tuber Resistance to Phytophthora infestans in Wild Relatives of Potato.

    PubMed

    Khiutti, A; Spooner, D M; Jansky, S H; Halterman, D A

    2015-09-01

    Potato late blight, caused by the oomycete phytopathogen Phytophthora infestans, is a devastating disease found in potato-growing regions worldwide. Long-term management strategies to control late blight include the incorporation of host resistance to predominant strains. However, due to rapid genetic changes within pathogen populations, rapid and recurring identification and integration of novel host resistance traits is necessary. Wild relatives of potato offer a rich source of desirable traits, including late blight resistance, but screening methods can be time intensive. We tested the ability of taxonomy, ploidy, crossing group, breeding system, and geography to predict the presence of foliar and tuber late blight resistance in wild Solanum spp. Significant variation for resistance to both tuber and foliar late blight was found within and among species but there was no discernable predictive power based on taxonomic series, clade, ploidy, breeding system, elevation, or geographic location. We observed a moderate but significant correlation between tuber and foliar resistance within species. Although previously uncharacterized sources of both foliar and tuber resistance were identified, our study does not support an assumption that taxonomic or geographic data can be used to predict sources of late blight resistance in wild Solanum spp. PMID:25871860

  13. Altering Transplantation Time to Avoid Periods of High Temperature Can Efficiently Reduce Bacterial Wilt Disease Incidence with Tomato.

    PubMed

    Wei, Zhong; Huang, Jian-Feng; Hu, Jie; Gu, Yi-An; Yang, Chun-Lan; Mei, Xin-Lan; Shen, Qi-Rong; Xu, Yang-Chun; Friman, Ville-Petri

    2015-01-01

    Tomato bacterial wilt caused by Ralstonia solanacearum bacterium is a severe problem in Southern China, where relatively high environmental temperatures commonly prevails during the crop seasons. Previous research has indicated that bacterial wilt disease incidence generally increases during the warm months of summer leading to reduced tomato yield. Moreover, the efficacy of bio-organic fertilizers (BOFs)-organic compost fortified with pathogen-suppressive bacteria-is often lost during the periods of high environmental temperatures. Here we studied if the disease incidence could be reduced and the BOF performance enhanced by simply preponing and postponing the traditional seedling transplantation times to avoid tomato plant development during periods of high environmental temperature. To this end, a continuous, two-year field experiment was conducted to evaluate the performance of BOF in two traditional (late-spring [LS] and early-autumn [EA]) and two alternative (early-spring [ES] and late-autumn [LA]) crop seasons. We found that changing the transplantation times reduced the mean disease incidence from 33.9% (LS) and 54.7% (EA) to 11.1% (ES) and 7.1% (LA), respectively. Reduction in disease incidence correlated with the reduction in R. Solanacearum pathogen density in the tomato plant rhizosphere and stem base. Applying BOF during alternative transplantation treatments improved biocontrol efficiency from 43.4% (LS) and 3.1% (EA) to 67.4% (ES) and 64.8% (LA). On average, the mean maximum air temperatures were positively correlated with the disease incidence, and negatively correlated with the BOF biocontrol efficacy over the crop seasons. Crucially, even though preponing the transplantation time reduced the tomato yield in general, it was still economically more profitable compared to LS season due to reduced crop losses and relatively higher market prices. Preponing and postponing traditional tomato transplantation times to cooler periods could thus offer simple

  14. Altering Transplantation Time to Avoid Periods of High Temperature Can Efficiently Reduce Bacterial Wilt Disease Incidence with Tomato

    PubMed Central

    Wei, Zhong; Huang, Jian-Feng; Hu, Jie; Gu, Yi-An; Yang, Chun-Lan; Mei, Xin-Lan; Shen, Qi-Rong; Xu, Yang-Chun; Friman, Ville-Petri

    2015-01-01

    Tomato bacterial wilt caused by Ralstonia solanacearum bacterium is a severe problem in Southern China, where relatively high environmental temperatures commonly prevails during the crop seasons. Previous research has indicated that bacterial wilt disease incidence generally increases during the warm months of summer leading to reduced tomato yield. Moreover, the efficacy of bio-organic fertilizers (BOFs)–organic compost fortified with pathogen-suppressive bacteria—is often lost during the periods of high environmental temperatures. Here we studied if the disease incidence could be reduced and the BOF performance enhanced by simply preponing and postponing the traditional seedling transplantation times to avoid tomato plant development during periods of high environmental temperature. To this end, a continuous, two-year field experiment was conducted to evaluate the performance of BOF in two traditional (late-spring [LS] and early-autumn [EA]) and two alternative (early-spring [ES] and late-autumn [LA]) crop seasons. We found that changing the transplantation times reduced the mean disease incidence from 33.9% (LS) and 54.7% (EA) to 11.1% (ES) and 7.1% (LA), respectively. Reduction in disease incidence correlated with the reduction in R. Solanacearum pathogen density in the tomato plant rhizosphere and stem base. Applying BOF during alternative transplantation treatments improved biocontrol efficiency from 43.4% (LS) and 3.1% (EA) to 67.4% (ES) and 64.8% (LA). On average, the mean maximum air temperatures were positively correlated with the disease incidence, and negatively correlated with the BOF biocontrol efficacy over the crop seasons. Crucially, even though preponing the transplantation time reduced the tomato yield in general, it was still economically more profitable compared to LS season due to reduced crop losses and relatively higher market prices. Preponing and postponing traditional tomato transplantation times to cooler periods could thus offer

  15. Cytotoxicity in bacterial cultures: interaction and cell-specificity, possible factors in periodontal disease.

    PubMed

    Johansson, A; Bergenholtz, A; Holm, S E

    1994-09-01

    Cytotoxicity in culture media of various growing bacterial strains was estimated by Cr-51 release of labelled target-cells. Interaction studies were made by adding each of the different UV-killed bacteria to the medium with viable bacteria. The reference oral bacterial strains were: Actinobacillus actinomycetemcomitans Y4, Porphyromonas gingivalis, Fusobacterium nucleatum and Streptococcus mitis, which were compared with the reference bacteria Staphylococcus aureus 209 and Staphylococcus epidermidis. The target cells were: gingival fibroblasts (GF), periodontal membrane fibroblasts (PMF), pulpal fibroblasts (PF), HeLa-cells (HeLa), and lymphoid neoplasm cells (LN). Synergistic, as well as antagonistic, effects on target cells were observed. The cytotoxicity of A. actinomycetemcomitans in presence of P. gingivalis is neutralized while in presence of S. aureus it was increased. Bacterial interactions with F. nucleatum and P. gingivalis cytotoxicity were observed. The cytotoxicity of F. nucleatum was increased when cultured together with A. actinomycetemcomitans. Each cell type reacted differently to the toxicity of the supernatant of growth medium in which the same bacterial strain had been cultivated, which indicates cell specificity of the toxins. PMID:7799211

  16. Spleen size is an indirect indicator of rainbow trout bacterial cold water disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contribution of the spleen to anti-bacterial immunity in lower vertebrates is poorly understood. The spleen first appears as a recognizable organ in shark and bony fish lineages while factors influencing its size and functions in lower vertebrates have received little attention. We have previou...

  17. Draft genome sequence of XANTHOMONAS ARBORICOLA strain 3004, causal agent of bacterial disease on barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report here the annotated genome sequence of XANTHOMONAS ARBORICOLA str. 3004, a Gram-negative phytopathogenic bacteria that includes several pathovars characterized by virulence specificity. Strain 3004 was isolated from barley leaves with symptoms of streak (bacterial blight) and also can infec...

  18. Impact of soil heat on reassembly of bacterial communities in the rhizosphere microbiome and plant disease suppression.

    PubMed

    van der Voort, Menno; Kempenaar, Marcel; van Driel, Marc; Raaijmakers, Jos M; Mendes, Rodrigo

    2016-04-01

    The rhizosphere microbiome offers a range of ecosystem services to the plant, including nutrient acquisition and tolerance to (a)biotic stress. Here, analysing the data by Mendes et al. (2011), we show that short heat disturbances (50 or 80 °C, 1 h) of a soil suppressive to the root pathogenic fungus Rhizoctonia solani caused significant increase in alpha diversity of the rhizobacterial community and led to partial or complete loss of disease protection. A reassembly model is proposed where bacterial families that are heat tolerant and have high growth rates significantly increase in relative abundance after heat disturbance, while temperature-sensitive and slow-growing bacteria have a disadvantage. The results also pointed to a potential role of slow-growing, heat-tolerant bacterial families from Actinobacteria and Acidobacteria phyla in plant disease protection. In conclusion, short heat disturbance of soil results in rearrangement of rhizobacterial communities and this is correlated with changes in the ecosystem service disease suppression. PMID:26833547

  19. Transcriptome of American Oysters, Crassostrea virginica, in Response to Bacterial Challenge: Insights into Potential Mechanisms of Disease Resistance

    PubMed Central

    McDowell, Ian C.; Nikapitiya, Chamilani; Aguiar, Derek; Lane, Christopher E.; Istrail, Sorin; Gomez-Chiarri, Marta

    2014-01-01

    The American oyster Crassostrea virginica, an ecologically and economically important estuarine organism, can suffer high mortalities in areas in the Northeast United States due to Roseovarius Oyster Disease (ROD), caused by the gram-negative bacterial pathogen Roseovarius crassostreae. The goals of this research were to provide insights into: 1) the responses of American oysters to R. crassostreae, and 2) potential mechanisms of resistance or susceptibility to ROD. The responses of oysters to bacterial challenge were characterized by exposing oysters from ROD-resistant and susceptible families to R. crassostreae, followed by high-throughput sequencing of cDNA samples from various timepoints after disease challenge. Sequence data was assembled into a reference transcriptome and analyzed through differential gene expression and functional enrichment to uncover genes and processes potentially involved in responses to ROD in the American oyster. While susceptible oysters experienced constant levels of mortality when challenged with R. crassostreae, resistant oysters showed levels of mortality similar to non-challenged oysters. Oysters exposed to R. crassostreae showed differential expression of transcripts involved in immune recognition, signaling, protease inhibition, detoxification, and apoptosis. Transcripts involved in metabolism were enriched in susceptible oysters, suggesting that bacterial infection places a large metabolic demand on these oysters. Transcripts differentially expressed in resistant oysters in response to infection included the immune modulators IL-17 and arginase, as well as several genes involved in extracellular matrix remodeling. The identification of potential genes and processes responsible for defense against R. crassostreae in the American oyster provides insights into potential mechanisms of disease resistance. PMID:25122115

  20. National Institute of Allergy and Infectious Disease (NIAID) Funding for Studies of Hospital-Associated Bacterial Pathogens: Are Funds Proportionate to Burden of Disease?

    PubMed Central

    2012-01-01

    Background Hospital-associated infections (HAIs) are associated with a considerable burden of disease and direct costs greater than $17 billion. The pathogens that cause the majority of serious HAIs are Enterococcus faecium, Staphylococcus aureus, Clostridium difficile, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species, referred as ESCKAPE. We aimed to determine the amount of funding the National Institute of Health (NIH) National Institute of Allergy and Infectious Diseases (NIAID) allocates to research on antimicrobial resistant pathogens, particularly ESCKAPE pathogens. Methods The NIH Research Portfolio Online Reporting Tools (RePORT) database was used to identify NIAID antimicrobial resistance research grants funded in 2007-2009 using the terms "antibiotic resistance," "antimicrobial resistance," and "hospital-associated infection." Results Funding for antimicrobial resistance grants has increased from 2007-2009. Antimicrobial resistance funding for bacterial pathogens has seen a smaller increase than non-bacterial pathogens. The total funding for all ESKCAPE pathogens was $ 22,005,943 in 2007, $ 30,810,153 in 2008 and $ 49,801,227 in 2009. S. aureus grants received $ 29,193,264 in FY2009, the highest funding amount of all the ESCKAPE pathogens. Based on 2009 funding data, approximately $1,565 of research money was spent per S. aureus related death and $750 of was spent per C. difficile related death. Conclusions Although the funding for ESCKAPE pathogens has increased from 2007 to 2009, funding levels for antimicrobial resistant bacteria-related grants is still lower than funding for antimicrobial resistant non-bacterial pathogens. Efforts may be needed to improve research funding for resistant-bacterial pathogens, particularly as their clinical burden increases. PMID:22958856

  1. Inheritance of rainbow trout Oncorhynchus mykiss spleen size and correlation with bacterial cold water disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infectious disease causes substantial loss in aquaculture and selective breeding for increased innate resistance offers an attractive strategy for controlling disease. In 2005, the NCCCWA implemented a selective breeding program to increase rainbow trout survival following challenge with Flavobacte...

  2. Bacterial immunostimulants--mechanism of action and clinical application in respiratory diseases.

    PubMed

    Rozy, Adriana; Chorostowska-Wynimko, Joanna

    2008-01-01

    Immunity towards bacteria might be achieved as a result of natural processes following infection, or as a consequence of medical intervention including vaccination, administration of immunoglobulins or therapy with immunostimulants derived from bacteria. Bacterial immunostimulants (ISs) containing bacterial lysate (OM-85 BV, LW 50020) or components of bacterial cells (ribosomal extracts) were shown to induce a non-specific response (i.e. intensification of phagocytosis) but also to orchestrate both cellular (B, T cell stimulation) and humoral responses (antibodies and proinflammatory cytokines production). Therefore, the duality of their immunomodulatory activity mimics or, to a certain extent, repeats the immune response evoked by the intrusion of a pathogen into the human body, which is initially non-specific, but subsequently becomes specific. However, their clinical efficacy in the prevention of respiratory tract infection (RTI) is still debated. This article reviews their mechanism of action, as well as the available clinical data, discussing the pros and cons of their use in the prevention of RITs in children and adults. PMID:19003766

  3. The pathophysiology of bacterial cold water disease in selectively-bred rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding programs that select for fish that exhibit disease resistance are important elements of aquaculture. A current challenge in selecting for disease resistance is recognizing and understanding the mechanisms that lead to disease resistance. Infectivity trials that monitor mortality and allow...

  4. A Benefit of High Temperature: Increased Effectiveness of a Rice Bacterial Blight Disease Resistance Gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High temperatures promote development of many plant diseases and reduce effectiveness of disease resistance (R) genes. In many rice producing countries, two crops of rice are produced, with more disease occurring in the season with higher day/night temperatures. While studying the factors that influ...

  5. Neutrophil CD64 as a Marker of Bacterial Infection in Acute Exacerbations of Chronic Obstructive Pulmonary Disease.

    PubMed

    Qian, Wei; Huang, Gao-Zhong

    2016-08-01

    Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are responsible for most mortality in patients with chronic obstructive pulmonary disease (COPD) and are caused mainly by bacterial infection. We analyzed and compared neutrophil CD64 expression (using the ratio of CD64 level in neutrophils to that in lymphocytes as an index), serum C-reactive protein (CRP), procalcitonin (PCT) levels, white blood cell (WBC) count, and neutrophil percentage among healthy subjects and patients with stable COPD or AECOPD. Compared with patients with COPD and healthy subjects, patients with AECOPD demonstrated significantly increased CD64 index, CRP, PCT, WBC count, and neutrophil percentage. Interestingly, CD64 index and PCT were both significantly higher in patients with AECOPD with positive bacterial sputum culture than those with negative culture. Furthermore, CD64 index and PCT were positively correlated in AECOPD, and there was also correlation between CD64 index and CRP, WBC, and neutrophil percentage. These data suggest that CD64 index is a relevant marker of bacterial infection in AECOPD. We divided patients with AECOPD into CD64-guided group and conventional treatment group. In CD64-guided group, clinicians prescribed antibiotics based on CD64 index; while in the conventional treatment group, clinicians relied on experience and clinical symptoms to determine the necessity for antibiotics. We found that the efficacy of antibiotic treatment in CD64-guided group was significantly improved compared with the conventional treatment group, including reduction of hospital stays and cost and shortened antibiotic treatment duration. Thus, the CD64 index has important diagnostic and therapeutic implications for antibiotic treatment of patients with AECOPD. PMID:27224474

  6. Successional changes in bacterial communities during the development of black band disease on the reef coral, Montipora hispida.

    PubMed

    Sato, Yui; Willis, Bette L; Bourne, David G

    2010-02-01

    Black band disease (BBD) consists of a mat-forming microbial consortium that migrates across coral colonies causing rapid tissue loss. Although BBD-associated microbial communities have been well characterized, little is known regarding how these complex bacterial consortia develop. This study analyzed successional changes in microbial communities leading to the development of BBD. Long-term monitoring of tagged corals throughout outbreaks of BBD in the central Great Barrier Reef documented cyanobacterium-infected lesions, herein termed cyanobacterial patch(es) (CP), which were macroscopically distinct from BBD and preceded the onset of BBD in 19% of the cases. Dominant cyanobacteria within CP lesions were morphologically distinct from ones dominating BBD lesions. Clone libraries and terminal restriction fragment length polymorphism analysis confirmed shifts within cyanobacterial assemblages, from Blennothrix sp.-affiliated sequences dominating CP lesions, to Oscillatoria sp.-affiliated sequences, similar to those retrieved from other BBD samples worldwide, dominating BBD lesions. Bacterial 16S ribosomal RNA clone libraries also showed shifts in bacterial ribotypes during transitions from CP to BBD, with Alphaproteobacteria-affiliated sequences dominant in CP libraries, whereas gammaproteobacterial and cyanobacterial ribotypes were more abundant in BBD clone libraries. Sequences affiliated with organisms identified in sulfur cycling were commonly retrieved from lesions showing characteristic field signs of BBD. As high sulfide concentrations have been implicated in BBD-mediated coral tissue degradation, proliferation of a microbial community actively involved in sulfur cycling potentially contributes to the higher progression rates found for BBD compared with CP lesions. Results show how microbial colonization of indistinct lesions may facilitate a common coral disease with proven ecological effects on coral populations. PMID:19776765

  7. Evidence of major genes for resistance to bacterial cold-water disease in rainbow trout using mixed inheritance multiple-threshold models and Bayesian segregation analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PURPOSE: Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture, and in 2005, a rainbow trout breeding program was initiated at the NCCCWA to select for increased disease survival. The main objectives of this study were to determine the mode of inheritance of di...

  8. A longitudinal assessment of changes in bacterial community composition associated with the development of periodontal disease in dogs.

    PubMed

    Wallis, Corrin; Marshall, Mark; Colyer, Alison; O'Flynn, Ciaran; Deusch, Oliver; Harris, Stephen

    2015-12-31

    Periodontal disease is the most widespread oral disease in dogs. Whilst the involvement of bacteria in the aetiology of periodontitis is well established the role of individual species and their complex interactions with the host is not well understood. The objective of this research was therefore to perform a longitudinal study in dogs to identify the changes that occur in subgingival bacterial communities during the transition from mild gingivitis to the early stages of periodontitis (<25% attachment loss). Subgingival plaque samples were collected from individual teeth of 52 miniature schnauzer dogs every six weeks for up to 60 weeks. The microbial composition of plaque samples was determined using 454-pyrosequencing of the 16S rDNA. A group of aerobic Gram negative species, including Bergeyella zoohelcum COT-186, Moraxella sp. COT-017, Pasteurellaceae sp. COT-080, and Neisseria shayeganii COT-090 decreased in proportion as teeth progressed to mild periodontitis. In contrast, there was less evidence that increases in the proportion of individual species were associated with the onset of periodontitis, although a number of species (particularly members of the Firmicutes) became more abundant as gingivitis severity increased. There were small increases in Shannon diversity, suggesting that plaque community membership remains relatively stable but that bacterial proportions change during progression into periodontitis. This is the first study to demonstrate the temporal dynamics of the canine oral microbiota; it showed that periodontitis results from a microbial succession predominantly characterised by a reduction of previously abundant, health associated taxa. PMID:26507828

  9. Bacterial Immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of bacterial agents reside in and around the environment that can cause illness and death in a poultry flock. Many cause disseminated disease while others exert more local effects such as the respiratory or gastrointestinal tract. The host, for our current purposes the laying hen, has de...

  10. Comparing bacterial community composition between healthy and white plague-like disease states in Orbicella annularis using PhyloChip™ G3 microarrays.

    PubMed

    Kellogg, Christina A; Piceno, Yvette M; Tom, Lauren M; DeSantis, Todd Z; Gray, Michael A; Zawada, David G; Andersen, Gary L

    2013-01-01

    Coral disease is a global problem. Diseases are typically named or described based on macroscopic changes, but broad signs of coral distress such as tissue loss or discoloration are unlikely to be specific to a particular pathogen. For example, there appear to be multiple diseases that manifest the rapid tissue loss that characterizes 'white plague.' PhyloChip™ G3 microarrays were used to compare the bacterial community composition of both healthy and white plague-like diseased corals. Samples of lobed star coral (Orbicella annularis, formerly of the genus Montastraea[1]) were collected from two geographically distinct areas, Dry Tortugas National Park and Virgin Islands National Park, to determine if there were biogeographic differences between the diseases. In fact, all diseased samples clustered together, however there was no consistent link to Aurantimonas coralicida, which has been described as the causative agent of white plague type II. The microarrays revealed a large amount of bacterial heterogeneity within the healthy corals and less diversity in the diseased corals. Gram-positive bacterial groups (Actinobacteria, Firmicutes) comprised a greater proportion of the operational taxonomic units (OTUs) unique to healthy samples. Diseased samples were enriched in OTUs from the families Corynebacteriaceae, Lachnospiraceae, Rhodobacteraceae, and Streptococcaceae. Much previous coral disease work has used clone libraries, which seem to be methodologically biased toward recovery of Gram-negative bacterial sequences and may therefore have missed the importance of Gram-positive groups. The PhyloChip™data presented here provide a broader characterization of the bacterial community changes that occur within Orbicella annularis during the shift from a healthy to diseased state. PMID:24278181

  11. Comparing bacterial community composition between healthy and white plague-like disease states in Orbicella annularis using PhyloChip™ G3 microarrays

    USGS Publications Warehouse

    Kellogg, Christina A.; Piceno, Yvette M.; Tom, Lauren M.; DeSantis, Todd Z.; Gray, Michael A.; Zawada, David G.; Andersen, Gary L.

    2013-01-01

    Coral disease is a global problem. Diseases are typically named or described based on macroscopic changes, but broad signs of coral distress such as tissue loss or discoloration are unlikely to be specific to a particular pathogen. For example, there appear to be multiple diseases that manifest the rapid tissue loss that characterizes ‘white plague.’ PhyloChip™ G3 microarrays were used to compare the bacterial community composition of both healthy and white plague-like diseased corals. Samples of lobed star coral (Orbicella annularis, formerly of the genus Montastraea [1]) were collected from two geographically distinct areas, Dry Tortugas National Park and Virgin Islands National Park, to determine if there were biogeographic differences between the diseases. In fact, all diseased samples clustered together, however there was no consistent link to Aurantimonas coralicida, which has been described as the causative agent of white plague type II. The microarrays revealed a large amount of bacterial heterogeneity within the healthy corals and less diversity in the diseased corals. Gram-positive bacterial groups (Actinobacteria, Firmicutes) comprised a greater proportion of the operational taxonomic units (OTUs) unique to healthy samples. Diseased samples were enriched in OTUs from the families Corynebacteriaceae, Lachnospiraceae, Rhodobacteraceae, and Streptococcaceae. Much previous coral disease work has used clone libraries, which seem to be methodologically biased toward recovery of Gram-negative bacterial sequences and may therefore have missed the importance of Gram-positive groups. The PhyloChip™ data presented here provide a broader characterization of the bacterial community changes that occur within Orbicella annularis during the shift from a healthy to diseased state.

  12. Comparing Bacterial Community Composition between Healthy and White Plague-Like Disease States in Orbicella annularis Using PhyloChip™ G3 Microarrays

    PubMed Central

    Kellogg, Christina A.; Piceno, Yvette M.; Tom, Lauren M.; DeSantis, Todd Z.; Gray, Michael A.; Zawada, David G.; Andersen, Gary L.

    2013-01-01

    Coral disease is a global problem. Diseases are typically named or described based on macroscopic changes, but broad signs of coral distress such as tissue loss or discoloration are unlikely to be specific to a particular pathogen. For example, there appear to be multiple diseases that manifest the rapid tissue loss that characterizes ‘white plague.’ PhyloChip™ G3 microarrays were used to compare the bacterial community composition of both healthy and white plague-like diseased corals. Samples of lobed star coral (Orbicella annularis, formerly of the genus Montastraea [1]) were collected from two geographically distinct areas, Dry Tortugas National Park and Virgin Islands National Park, to determine if there were biogeographic differences between the diseases. In fact, all diseased samples clustered together, however there was no consistent link to Aurantimonas coralicida, which has been described as the causative agent of white plague type II. The microarrays revealed a large amount of bacterial heterogeneity within the healthy corals and less diversity in the diseased corals. Gram-positive bacterial groups (Actinobacteria, Firmicutes) comprised a greater proportion of the operational taxonomic units (OTUs) unique to healthy samples. Diseased samples were enriched in OTUs from the families Corynebacteriaceae, Lachnospiraceae, Rhodobacteraceae, and Streptococcaceae. Much previous coral disease work has used clone libraries, which seem to be methodologically biased toward recovery of Gram-negative bacterial sequences and may therefore have missed the importance of Gram-positive groups. The PhyloChip™data presented here provide a broader characterization of the bacterial community changes that occur within Orbicella annularis during the shift from a healthy to diseased state. PMID:24278181

  13. Microfungi and canopy biology: The distribution of an endemic foliar pathogen and its effects on carbon dioxide flux

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phaeocryptopus gaeumannii, causal organism of the foliar disease Swiss needle cast of Douglas-fir, is endemic to the Pacific Northwest and widely distributed throughout the natural range of its host. The fungus produces fruiting bodies, pseudothecia, which emerge through and occlude stomata. To cont...

  14. Estimation of Canopy Foliar Biomass with Spectral Reflectance Measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canopy foliar biomass, defined as the product of leaf dry matter content and leaf area index, is an important measurement for global biogeochemical cycles. This study explores the potential for retrieving foliar biomass in green canopies using a spectral index, the Normalized Dry Matter Index (NDMI)...

  15. FOLIAR WASHOFF OF PESTICIDES (FWOP) MODEL: DEVELOPMENT AND EVALUATION

    EPA Science Inventory

    The Foliar Washoff of Pesticides (FWOP) Model was developed to provide an empirical simulation of pesticide washoff from plant leaf surfaces as influenced by rainfall amount. To evaluate the technique, simulations by the FWOP Model were compared to those by the foliar washoff alg...

  16. Modelling management strategies for a disease including undetected sub-clinical infection: bacterial kidney disease in Scottish salmon and trout farms.

    PubMed

    Murray, Alexander G; Hall, Malcolm; Munro, Lorna A; Wallace, I Stuart

    2011-09-01

    Disease is a major constraint on animal production and welfare in agriculture and aquaculture. Movement of animals between farms is one of the most significant routes of disease transmission and is particularly hard to control for pathogens with subclinical infection. Renibacterium salmoninarum causes bacterial kidney disease (BKD) in salmonid fish, but infection is often sub-clinical and may go undetected with major potential implications for disease control programmes. A Susceptible-Infected model of R. salmoninarum in Scottish aquaculture has been developed that subdivides the infected phase between known and undetected sub-clinically infected farms and diseased farms whose status is assumed to be known. Farms officially known to be infected are subject to movement controls restricting spread of infection. Model results are sensitive to prevalence of undetected infection, which is unknown. However, the modelling suggests that controls that reduce BKD prevalence include improve biosecurity on farms, including those not known to be infected, and improved detection of infection. Culling appears of little value for BKD control. BKD prevalence for rainbow trout farms is less sensitive to controls than it is for Atlantic salmon farms and so different management strategies may be required for the sectors. PMID:22094340

  17. A cohabitation challenge to compare the efficacies of vaccines for bacterial kidney disease (BKD) in chinook salmon Oncorhynchus tshawytscha

    USGS Publications Warehouse

    Alcorn, S.; Murray, A.L.; Pascho, R.J.; Varney, J.

    2005-01-01

    The relative efficacies of 1 commercial and 5 experimental vaccines for bacterial kidney disease (BKD) were compared through a cohabitation waterborne challenge. Groups of juvenile chinook salmon Oncorhynchus tshawytscha were vaccinated with one of the following: (1) killed Renibacterium salmoninarum ATCC 33209 (Rs 33209) cells; (2) killed Rs 33209 cells which had been heated to 37??C for 48 h, a process that destroys the p57 protein; (3) killed R. salmoninarum MT239 (Rs MT239) cells; (4) heated Rs MT239 cells; (5) a recombinant version of the p57 protein (r-p57) emulsified in Freund's incomplete adjuvant (FIA); (6) the commercial BKD vaccine Renogen; (7) phosphate-buffered saline (PBS) emulsified with an equal volume of FIA; or (8) PBS alone. Following injection, each fish was marked with a subcutaneous fluorescent latex tag denoting its treatment group and the vaccinated fish were combined into sham and disease challenge tanks. Two weeks after these fish were vaccinated, separate groups of fish were injected with either PBS or live R. salmoninarum GL64 and were placed inside coated-wire mesh cylinders (liveboxes) in the sham and disease challenge tanks, respectively. Mortalities in both tanks were recorded for 285 d. Any mortalities among the livebox fish were replaced with an appropriate cohort (infected with R. salmoninarum or healthy) fish. None of the bacterins evaluated in this study induced protective immunity against the R. salmoninarum shed from the infected livebox fish. The percentage survival within the test groups in the R. salmoninarum challenge tank ranged from 59% (heated Rs MT239 bacterin) to 81 % (PBS emulsified with FIA). There were no differences in the percentage survival among the PBS-, PBS/FIA-, r-p57-and Renogen-injected groups. There also were no differences in survival among the bacterin groups, regardless of whether the bacterial cells had been heated or left untreated prior to injection. ?? Inter-Research 2005.

  18. A cohabitation challenge to compare the efficacies of vaccines for bacterial kidney disease (BKD) in chinook salmon Oncorhynchus tshawytscha.

    PubMed

    Alcorn, Stewart; Murray, Anthony L; Pascho, Ronald J; Varney, Jed

    2005-02-28

    The relative efficacies of 1 commercial and 5 experimental vaccines for bacterial kidney disease (BKD) were compared through a cohabitation waterborne challenge. Groups of juvenile chinook salmon Oncorhynchus tshawytscha were vaccinated with one of the following: (1) killed Renibacterium salmoninarum ATCC 33209 (Rs 33209) cells; (2) killed Rs 33209 cells which had been heated to 37 degrees C for 48 h, a process that destroys the p57 protein; (3) killed R. salmoninarum MT239 (Rs MT239) cells; (4) heated Rs MT239 cells; (5) a recombinant version of the p57 protein (r-p57) emulsified in Freund's incomplete adjuvant (FIA); (6) the commercial BKD vaccine Renogen; (7) phosphate-buffered saline (PBS) emulsified with an equal volume of FIA; or (8) PBS alone. Following injection, each fish was marked with a subcutaneous fluorescent latex tag denoting its treatment group and the vaccinated fish were combined into sham and disease challenge tanks. Two weeks after these fish were vaccinated, separate groups of fish were injected with either PBS or live R. salmoninarum GL64 and were placed inside coated-wire mesh cylinders (liveboxes) in the sham and disease challenge tanks, respectively. Mortalities in both tanks were recorded for 285 d. Any mortalities among the livebox fish were replaced with an appropriate cohort (infected with R. salmoninarum or healthy) fish. None of the bacterins evaluated in this study induced protective immunity against the R. salmoninarum shed from the infected livebox fish. The percentage survival within the test groups in the R. salmoninarum challenge tank ranged from 59% (heated Rs MT239 bacterin) to 81% (PBS emulsified with FIA). There were no differences in the percentage survival among the PBS-, PBS/FIA-, r-p57- and Renogen-injected groups. There also were no differences in survival among the bacterin groups, regardless of whether the bacterial cells had been heated or left untreated prior to injection. PMID:15819430

  19. Hyperglycemia Impairs Neutrophil-Mediated Bacterial Clearance in Mice Infected with the Lyme Disease Pathogen

    PubMed Central

    Javid, Ashkan; Zlotnikov, Nataliya; Pětrošová, Helena; Tang, Tian Tian; Zhang, Yang; Bansal, Anil K.; Ebady, Rhodaba; Parikh, Maitry; Ahmed, Mijhgan; Sun, Chunxiang; Newbigging, Susan; Kim, Yae Ram; Santana Sosa, Marianna; Glogauer, Michael

    2016-01-01

    Insulin-insufficient type 1 diabetes is associated with attenuated bactericidal function of neutrophils, which are key mediators of innate immune responses to microbes as well as pathological inflammatory processes. Neutrophils are central to immune responses to the Lyme pathogen Borrelia burgdorferi. The effect of hyperglycemia on host susceptibility to and outcomes of B. burgdorferi infection has not been examined. The present study investigated the impact of sustained obesity-independent hyperglycemia in mice on bacterial clearance, inflammatory pathology and neutrophil responses to B. burgdorferi. Hyperglycemia was associated with reduced arthritis incidence but more widespread tissue colonization and reduced clearance of bacterial DNA in multiple tissues including brain, heart, liver, lung and knee joint. B. burgdorferi uptake and killing were impaired in neutrophils isolated from hyperglycemic mice. Thus, attenuated neutrophil function in insulin-insufficient hyperglycemia was associated with reduced B. burgdorferi clearance in target organs. These data suggest that investigating the effects of comorbid conditions such as diabetes on outcomes of B. burgdorferi infections in humans may be warranted. PMID:27340827

  20. Bacterial Spectrum and Antibiotic Resistance Patterns of Ocular Infection: Differences between External and Intraocular Diseases

    PubMed Central

    Wang, Nan; Yang, Qian; Tan, Yiwei; Lin, Liping; Huang, Qiang; Wu, Kaili

    2015-01-01

    This study aimed to compare the differences of microbial spectrum and antibiotic resistance patterns between external and intraocular bacterial infections in an eye hospital in South China. A total of 737 bacteria isolates from suspected ocular infections were included in this retrospective study covering the period 2010–2013. The organisms cultured from the ocular surface (cornea, conjunctiva) accounted for the majority of the isolates (82.77%, n = 610), followed by the intraocular (aqueous humor, vitreous fluid), which accounted for 17.23% (n = 127). The top three species accounting for the external ocular infections were S. epidermidis (35.25%), P. aeruginosa (8.03%), and S. simulans (4.43%). The top three species for the intraocular infections were S. epidermidis (14.96%), S. hominis (8.66%), and B. subtilis (7.87%). The bacteria from the external ocular surface were more sensitive to neomycin, while those from the intraocular specimens were more sensitive to levofloxacin (P < 0.01). Multidrug resistance was found in 89 bacteria (12.08%), including isolates from both external (13.28%) and intraocular samples (6.30%). The results of this study indicate that the bacteria spectrum of external and intraocular infections is variable in the setting. A high percentage of bacterial organisms were found to be primarily susceptible to neomycin for external infection and levofloxacin for intraocular infection. PMID:26576294

  1. Hyperglycemia Impairs Neutrophil-Mediated Bacterial Clearance in Mice Infected with the Lyme Disease Pathogen.

    PubMed

    Javid, Ashkan; Zlotnikov, Nataliya; Pětrošová, Helena; Tang, Tian Tian; Zhang, Yang; Bansal, Anil K; Ebady, Rhodaba; Parikh, Maitry; Ahmed, Mijhgan; Sun, Chunxiang; Newbigging, Susan; Kim, Yae Ram; Santana Sosa, Marianna; Glogauer, Michael; Moriarty, Tara J

    2016-01-01

    Insulin-insufficient type 1 diabetes is associated with attenuated bactericidal function of neutrophils, which are key mediators of innate immune responses to microbes as well as pathological inflammatory processes. Neutrophils are central to immune responses to the Lyme pathogen Borrelia burgdorferi. The effect of hyperglycemia on host susceptibility to and outcomes of B. burgdorferi infection has not been examined. The present study investigated the impact of sustained obesity-independent hyperglycemia in mice on bacterial clearance, inflammatory pathology and neutrophil responses to B. burgdorferi. Hyperglycemia was associated with reduced arthritis incidence but more widespread tissue colonization and reduced clearance of bacterial DNA in multiple tissues including brain, heart, liver, lung and knee joint. B. burgdorferi uptake and killing were impaired in neutrophils isolated from hyperglycemic mice. Thus, attenuated neutrophil function in insulin-insufficient hyperglycemia was associated with reduced B. burgdorferi clearance in target organs. These data suggest that investigating the effects of comorbid conditions such as diabetes on outcomes of B. burgdorferi infections in humans may be warranted. PMID:27340827

  2. World Health Organization Estimates of the Global and Regional Disease Burden of 22 Foodborne Bacterial, Protozoal, and Viral Diseases, 2010: A Data Synthesis

    PubMed Central

    Kirk, Martyn D.; Pires, Sara M.; Black, Robert E.; Caipo, Marisa; Crump, John A.; Devleesschauwer, Brecht; Döpfer, Dörte; Fazil, Aamir; Fischer-Walker, Christa L.; Hald, Tine; Hall, Aron J.; Keddy, Karen H.; Lake, Robin J.; Lanata, Claudio F.; Torgerson, Paul R.; Havelaar, Arie H.; Angulo, Frederick J.

    2015-01-01

    Background Foodborne diseases are important worldwide, resulting in considerable morbidity and mortality. To our knowledge, we present the first global and regional estimates of the disease burden of the most important foodborne bacterial, protozoal, and viral diseases. Methods and Findings We synthesized data on the number of foodborne illnesses, sequelae, deaths, and Disability Adjusted Life Years (DALYs), for all diseases with sufficient data to support global and regional estimates, by age and region. The data sources included varied by pathogen and included systematic reviews, cohort studies, surveillance studies and other burden of disease assessments. We sought relevant data circa 2010, and included sources from 1990–2012. The number of studies per pathogen ranged from as few as 5 studies for bacterial intoxications through to 494 studies for diarrheal pathogens. To estimate mortality for Mycobacterium bovis infections and morbidity and mortality for invasive non-typhoidal Salmonella enterica infections, we excluded cases attributed to HIV infection. We excluded stillbirths in our estimates. We estimate that the 22 diseases included in our study resulted in two billion (95% uncertainty interval [UI] 1.5–2.9 billion) cases, over one million (95% UI 0.89–1.4 million) deaths, and 78.7 million (95% UI 65.0–97.7 million) DALYs in 2010. To estimate the burden due to contaminated food, we then applied proportions of infections that were estimated to be foodborne from a global expert elicitation. Waterborne transmission of disease was not included. We estimate that 29% (95% UI 23–36%) of cases caused by diseases in our study, or 582 million (95% UI 401–922 million), were transmitted by contaminated food, resulting in 25.2 million (95% UI 17.5–37.0 million) DALYs. Norovirus was the leading cause of foodborne illness causing 125 million (95% UI 70–251 million) cases, while Campylobacter spp. caused 96 million (95% UI 52–177 million) foodborne

  3. Ecological ramifications of the direct foliar uptake of nitrogen.

    PubMed

    Sparks, Jed P

    2009-02-01

    The foliar incorporation of various reactive forms of nitrogen (N) has been identified and studied for nearly 30 years. However, the ecosystem-level ramifications of this uptake pathway have only recently been considered by the scientific community. In this review, I present our current understanding of the foliar uptake process and then discuss why this pathway of N addition to ecosystems should be considered separately from the bulk deposition of N to the soil surface. Direct foliar uptake is a direct addition of N to plant metabolism and could potentially more readily influence plant growth compared to soil-deposited N. Current ecosystem process models do not partition reactive N between foliar and soil entry pathways and the influence of N deposition on ecosystem C sequestration is likely inadequately represented in most models. I also outline several research priorities for the future understanding of the ecological consequences of foliar uptake of reactive N. PMID:18975011

  4. Filthy Flies? Experiments to Test Flies as Vectors of Bacterial Disease

    ERIC Educational Resources Information Center

    Shaffer, Julie J.; Warner, Kasey Jo; Hoback, W. Wyatt

    2007-01-01

    For more than 75 years, flies and other insects have been known to serve as mechanical vectors of infectious disease (Hegner, 1926). Flies have been shown to harbor over 100 different species of potentially pathogenic microorganisms and are known to transmit more than 65 infectious diseases (Greenberg, 1965). This laboratory exercise is a simple…

  5. Foliar nutrient retranslocation in Eucalyptus globulus.

    PubMed

    Saur, E; Nambiar, E K; Fife, D N

    2000-10-01

    We measured patterns of change in concentrations and contents of nitrogen, phosphorus, potassium, magnesium and calcium in fully expanded leaves of young Eucalyptus globulus (Labill.) trees growing in a plantation in southeastern Australia, over a 12-month period beginning at the onset of spring. There was significant net retranslocation of mobile nutrients on a seasonal basis from green leaves, coinciding with continued growth and production of foliage. There was a close positive relationship between initial nutrient content (N, P and K) of the leaf and amount retranslocated, and a tight coupling between N and P retranslocated from leaves. Net retranslocation was significantly correlated with basal area growth increments. Artificial shading of leaves resulted in senescence and reduction in leaf mass. It also induced retranslocation of N, P and K from leaves of different ages and from different position in the canopy. Although the mechanisms underlying the effects of shading intensity on these changes were not elucidated, shading provided an experimental tool for studying retranslocation. Comparison of the results with published data for Pinus radiata (D. Don) grown in the same environment indicated a similarity between the species in patterns of change in foliar nutrient contents and in factors governing foliar nutrient retranslocation, giving rise to unifying principles. PMID:11269962

  6. Pyrosequencing of the bacteria associated with Platygyra carnosus corals with skeletal growth anomalies reveals differences in bacterial community composition in apparently healthy and diseased tissues

    PubMed Central

    Ng, Jenny C. Y.; Chan, Yuki; Tun, Hein M.; Leung, Frederick C. C.; Shin, Paul K. S.; Chiu, Jill M. Y.

    2015-01-01

    Corals are rapidly declining globally due to coral diseases. Skeletal growth anomalies (SGA) or “coral tumors” are a group of coral diseases that affect coral reefs worldwide, including Hong Kong waters in the Indo-Pacific region. To better understand how bacterial communities may vary in corals with SGA, for the first time, we examined the bacterial composition associated with the apparently healthy and the diseased tissues of SGA-affected Platgyra carnosus using 16S ribosomal rRNA gene pyrosequencing. Taxonomic analysis revealed Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria as the main phyla in both the apparently healthy and the diseased tissues. A significant difference in the bacterial community composition was observed between the two conditions at the OTU level. Diseased tissues were associated with higher abundances of Acidobacteria and Gemmatimonadetes, and a lower abundance of Spirochaetes. Several OTUs belonging to Rhodobacteraceae, Rhizobiales, Gammaproteobacteria, and Cytophaga-Flavobacterium-Bacteroidetes (CFB) were strongly associated with the diseased tissues. These groups of bacteria may contain potential pathogens involved with the development of SGA or opportunistic secondary or tertiary colonizers that proliferated upon the health-compromised coral host. We suggest that these bacterial groups to be further studied based on inoculation experiments and testing of Koch's postulates in efforts to understand the etiology and progression of SGA. PMID:26539174

  7. Pyrosequencing of the bacteria associated with Platygyra carnosus corals with skeletal growth anomalies reveals differences in bacterial community composition in apparently healthy and diseased tissues.

    PubMed

    Ng, Jenny C Y; Chan, Yuki; Tun, Hein M; Leung, Frederick C C; Shin, Paul K S; Chiu, Jill M Y

    2015-01-01

    Corals are rapidly declining globally due to coral diseases. Skeletal growth anomalies (SGA) or "coral tumors" are a group of coral diseases that affect coral reefs worldwide, including Hong Kong waters in the Indo-Pacific region. To better understand how bacterial communities may vary in corals with SGA, for the first time, we examined the bacterial composition associated with the apparently healthy and the diseased tissues of SGA-affected Platgyra carnosus using 16S ribosomal rRNA gene pyrosequencing. Taxonomic analysis revealed Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria as the main phyla in both the apparently healthy and the diseased tissues. A significant difference in the bacterial community composition was observed between the two conditions at the OTU level. Diseased tissues were associated with higher abundances of Acidobacteria and Gemmatimonadetes, and a lower abundance of Spirochaetes. Several OTUs belonging to Rhodobacteraceae, Rhizobiales, Gammaproteobacteria, and Cytophaga-Flavobacterium-Bacteroidetes (CFB) were strongly associated with the diseased tissues. These groups of bacteria may contain potential pathogens involved with the development of SGA or opportunistic secondary or tertiary colonizers that proliferated upon the health-compromised coral host. We suggest that these bacterial groups to be further studied based on inoculation experiments and testing of Koch's postulates in efforts to understand the etiology and progression of SGA. PMID:26539174

  8. Genetic effects of ELISA-based segregation for control of bacterial kidney disease in Chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Hard, J.J.; Elliott, D.G.; Pascho, R.J.; Chase, D.M.; Park, L.K.; Winton, J.R.; Campton, D.E.

    2006-01-01

    We evaluated genetic variation in ability of Chinook salmon (Oncorhynchus tshawytscha) to resist two bacterial pathogens: Renibacterium salmoninarum, the agent of bacterial kidney disease (BKD), and Listonella anguillarum, an agent of vibriosis. After measuring R. salmoninarum antigen in 499 adults by enzyme-linked immunosorbent assay (ELISA), we mated each of 12 males with high or low antigen levels to two females with low to moderate levels and exposed subsets of their progeny to each pathogen separately. We found no correlation between R. salmoninarum antigen level in parents and survival of their progeny following pathogen exposure. We estimated high heritability for resistance to R. salmoninarum (survival h2 = 0.890 ?? 0.256 (mean ?? standard error)) independent of parental antigen level, but low heritability for resistance to L. anguillarum (h2 = 0.128 ?? 0.078). The genetic correlation between these survivals (rA = -0.204 ?? 0.309) was near zero. The genetic and phenotypic correlations between survival and antigen levels among surviving progeny exposed to R. salmoninarum were both negative (rA = -0.716 ?? 0.140; rP = -0.378 ?? 0.041), indicating that variation in antigen level is linked to survival. These results suggest that selective culling of female broodstock with high antigen titers, which is effective in controlling BKD in salmon hatcheries, will not affect resistance of their progeny. ?? 2006 NRC.

  9. A family of conserved bacterial effectors inhibits salicylic acid-mediated basal immunity and promotes disease necrosis in plants.

    PubMed

    DebRoy, Sruti; Thilmony, Roger; Kwack, Yong-Bum; Nomura, Kinya; He, Sheng Yang

    2004-06-29

    Salicylic acid (SA)-mediated host immunity plays a central role in combating microbial pathogens in plants. Inactivation of SA-mediated immunity, therefore, would be a critical step in the evolution of a successful plant pathogen. It is known that mutations in conserved effector loci (CEL) in the plant pathogens Pseudomonas syringae (the Delta CEL mutation), Erwinia amylovora (the dspA/E mutation), and Pantoea stewartii subsp. stewartii (the wtsE mutation) exert particularly strong negative effects on bacterial virulence in their host plants by unknown mechanisms. We found that the loss of virulence in Delta CEL and dspA/E mutants was linked to their inability to suppress cell wall-based defenses and to cause normal disease necrosis in Arabidopsis and apple host plants. The Delta CEL mutant activated SA-dependent callose deposition in wild-type Arabidopsis but failed to elicit high levels of callose-associated defense in Arabidopsis plants blocked in SA accumulation or synthesis. This mutant also multiplied more aggressively in SA-deficient plants than in wild-type plants. The hopPtoM and avrE genes in the CEL of P. syringae were found to encode suppressors of this SA-dependent basal defense. The widespread conservation of the HopPtoM and AvrE families of effectors in various bacteria suggests that suppression of SA-dependent basal immunity and promotion of host cell death are important virulence strategies for bacterial infection of plants. PMID:15210989

  10. [Biofilms of the oral cavity. Formation, development and involvement in the onset of diseases related to bacterial plaque increase].

    PubMed

    Bortolaia, C; Sbordone, L

    2002-05-01

    Biofilm is defined as a community of bacteria intimately associated with each other and included within an exopolymer matrix: this biological unit exhibits its own properties, quite different in comparison with those showed by the single species in planktonic form. The oral cavity appears as an open ecosystem, with a dynamic balance between the entrance of microrganisms, colonisation modalities and host defences aimed to their removal: to avoid elimination, bacteria need to adhere to either hard dental surfaces or epithelial surfaces. The oral biofilm formation and development, and the inside selection of specific microrganisms have been correlated with the most common oral pathologies, such as dental caries, periodontal disease and peri-implantitis. Many of these bacteria are usual saprophytes of the oral environment, that, in particular situations, can overcome and express their virulence factors: to better understand the mechanisms of these pathologies it's necessary to know the complex interactions between all the bacterial species inside the biofilm and host tissues and responses. The present paper is a review of the most significant studies on the biofilm development modalities, their correlations with either health or illness of the oral cavity, the bacterial co-aggregation strategies and the biofilm response to antimicrobial agents. PMID:12070469

  11. Polycystic kidney disease in four British shorthair cats with successful treatment of bacterial cyst infection.

    PubMed

    Nivy, R; Lyons, L A; Aroch, I; Segev, G

    2015-09-01

    Polycystic kidney disease is the most common inherited disorder in cats. Renal cysts progressively increase in size and number, resulting in a gradual decrease in kidney function. An autosomal dominant mutation in exon 29 of the polycystin-1 gene has been identified, mostly in Persian and Persian-related breeds. This case study describes polycystic kidney disease in four British shorthair cats, of which two had the same genetic mutation reported in Persian and Persian-related cats. This likely reflects introduction of this mutation into the British shorthair breeding line because of previous outcrossing with Persian cats. An infected renal cyst was diagnosed and successfully treated in one of the cats. This is a commonly reported complication in human polycystic kidney disease, and to the authors' knowledge has not previously been reported in cats with polycystic kidney disease. PMID:25677715

  12. Soybean (Glycine max L. Merr.) Sprouts Germinated under Red Light Irradiation Induce Disease Resistance against Bacterial Rotting Disease

    PubMed Central

    Dhakal, Radhika; Park, Euiho; Lee, Se-Weon; Baek, Kwang-Hyun

    2015-01-01

    Specific wavelengths of light can exert various physiological changes in plants, including effects on responses to disease incidence. To determine whether specific light wavelength had effects on rotting disease caused by Pseudomonas putida 229, soybean sprouts were germinated under a narrow range of wavelengths from light emitting diodes (LEDs), including red (650–660), far red (720–730) and blue (440–450 nm) or broad range of wavelength from daylight fluorescence bulbs. The controls were composed of soybean sprouts germinated in darkness. After germination under different conditions for 5 days, the soybean sprouts were inoculated with P. putida 229 and the disease incidence was observed for 5 days. The sprouts exposed to red light showed increased resistance against P. putida 229 relative to those grown under other conditions. Soybean sprouts germinated under red light accumulated high levels of salicylic acid (SA) accompanied with up-regulation of the biosynthetic gene ICS and the pathogenesis- related (PR) gene PR-1, indicating that the resistance was induced by the action of SA via de novo synthesis of SA in the soybean sprouts by red light irradiation. Taken together, these data suggest that only the narrow range of red light can induce disease resistance in soybean sprouts, regulated by the SA-dependent pathway via the de novo synthesis of SA and up-regulation of PR genes. PMID:25679808

  13. Decreased mortality of lake michigan chinook salmon after bacterial kidney disease challenge: Evidence for pathogen-driven selection?

    USGS Publications Warehouse

    Purcell, M.K.; Murray, A.L.; Elz, A.; Park, L.K.; Marcquenski, S.V.; Winton, J.R.; Alcorn, S.W.; Pascho, R.J.; Elliott, D.G.

    2008-01-01

    In the late 1960s, Chinook salmon Oncorhynchus tshawytscha from the Green River, Washington, were successfully introduced into Lake Michigan. During spring from1988 to 1992, large fish die-offs affecting Chinook salmon occurred in the lake. Multiple ecological factors probably contributed to the severity of the fish kills, but the only disease agent found regularly was Renibacterium salmoninarum, the causative agent of bacterial kidney disease. in this study, survival after challenge by R. salmoninarum was compared between two Chinook salmon stocks: a Lake Michigan stock from Wisconsin (WI) and the progenitor stock from the Green River. We found that the WI stock had significantly greater survival than the Green River stock. Next, the WI and Green River stocks were exposed to the marine pathogen Listonella anguillarum (formerly Vibrio anguillarum), one of the causative agents of vibriosis; survival after this challenge was significantly poorer for the WI stock than for the Green River stock. A close genetic relationship between the Green River and WI stocks was confirmed by analyzing 13 microsatellite loci. These results collectively suggest that disease susceptibility of Lake Michigan Chinook salmon has diverged from that of the source population, possibly in response to pathogen-driven selection. ?? Copyright by the American Fisheries Society 2008.

  14. Shifts in bacterial communities of two caribbean reef-building coral species affected by white plague disease

    PubMed Central

    Cárdenas, Anny; Rodriguez-R, Luis M; Pizarro, Valeria; Cadavid, Luis F; Arévalo-Ferro, Catalina

    2012-01-01

    Coral reefs are deteriorating at an alarming rate mainly as a consequence of the emergence of coral diseases. The white plague disease (WPD) is the most prevalent coral disease in the southwestern Caribbean, affecting dozens of coral species. However, the identification of a single causal agent has proved problematic. This suggests more complex etiological scenarios involving alterations in the dynamic interaction between environmental factors, the coral immune system and the symbiotic microbial communities. Here we compare the microbiome of healthy and WPD-affected corals from the two reef-building species Diploria strigosa and Siderastrea siderea collected at the Tayrona National Park in the Caribbean of Colombia. Microbiomes were analyzed by combining culture-dependent methods and pyrosequencing of 16S ribosomal DNA (rDNA) V5-V6 hypervariable regions. A total of 20 410 classifiable 16S rDNA sequences reads were obtained including all samples. No significant differences in operational taxonomic unit diversity were found between healthy and affected tissues; however, a significant increase of Alphaproteobacteria and a concomitant decrease in the Beta- and Gammaproteobacteria was observed in WPD-affected corals of both species. Significant shifts were also observed in the orders Rhizobiales, Caulobacteriales, Burkholderiales, Rhodobacterales, Aleteromonadales and Xanthomonadales, although they were not consistent between the two coral species. These shifts in the microbiome structure of WPD-affected corals suggest a loss of community-mediated growth control mechanisms on bacterial populations specific for each holobiont system. PMID:21955993

  15. Structured literature review of responses of cattle to viral and bacterial pathogens causing bovine respiratory disease complex.

    PubMed

    Grissett, G P; White, B J; Larson, R L

    2015-01-01

    Bovine respiratory disease (BRD) is an economically important disease of cattle and continues to be an intensely studied topic. However, literature summarizing the time between pathogen exposure and clinical signs, shedding, and seroconversion is minimal. A structured literature review of the published literature was performed to determine cattle responses (time from pathogen exposure to clinical signs, shedding, and seroconversion) in challenge models using common BRD viral and bacterial pathogens. After review a descriptive analysis of published studies using common BRD pathogen challenge studies was performed. Inclusion criteria were single pathogen challenge studies with no treatment or vaccination evaluating outcomes of interest: clinical signs, shedding, and seroconversion. Pathogens of interest included: bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV-1), parainfluenza-3 virus, bovine respiratory syncytial virus, Mannheimia haemolytica, Mycoplasma bovis, Pastuerella multocida, and Histophilus somni. Thirty-five studies and 64 trials were included for analysis. The median days to the resolution of clinical signs after BVDV challenge was 15 and shedding was not detected on day 12 postchallenge. Resolution of BHV-1 shedding resolved on day 12 and clinical signs on day 12 postchallenge. Bovine respiratory syncytial virus ceased shedding on day 9 and median time to resolution of clinical signs was on day 12 postchallenge. M. haemolytica resolved clinical signs 8 days postchallenge. This literature review and descriptive analysis can serve as a resource to assist in designing challenge model studies and potentially aid in estimation of duration of clinical disease and shedding after natural pathogen exposure. PMID:25929158

  16. Decreased mortality of Lake Michigan Chinook salmon after bacterial kidney disease challenge: evidence for pathogen-driven selection?

    PubMed

    Purcell, Maureen K; Murray, Anthony L; Elz, Anna; Park, Linda K; Marcquenski, Susan V; Winton, James R; Alcorn, Stewart W; Pascho, Ronald J; Elliott, Diane G

    2008-12-01

    In the late 1960s, Chinook salmon Oncorhynchus tshawytscha from the Green River, Washington, were successfully introduced into Lake Michigan. During spring from 1988 to 1992, large fish die-offs affecting Chinook salmon occurred in the lake. Multiple ecological factors probably contributed to the severity of the fish kills, but the only disease agent found regularly was Renibacterium salmoninarum, the causative agent of bacterial kidney disease. In this study, survival after challenge by R. salmoninarum was compared between two Chinook salmon stocks: a Lake Michigan stock from Wisconsin (WI) and the progenitor stock from the Green River. We found that the WI stock had significantly greater survival than the Green River stock. Next, the WI and Green River stocks were exposed to the marine pathogen Listonella anguillarum (formerly Vibrio anguillarum), one of the causative agents of vibriosis; survival after this challenge was significantly poorer for the WI stock than for the Green River stock. A close genetic relationship between the Green River and WI stocks was confirmed by analyzing 13 microsatellite loci. These results collectively suggest that disease susceptibility of Lake Michigan Chinook salmon has diverged from that of the source population, possibly in response to pathogen-driven selection. PMID:19306612

  17. Localization of the bacterial agent of juvenile oyster disease (Roseovarius crassostreae) within affected eastern oysters (Crassostrea virginica).

    PubMed

    Boardman, Cynthia L; Maloy, Aaron P; Boettcher, Katherine J

    2008-02-01

    The bacterium Roseovarius crassostreae causes seasonal mortalities among commercially produced eastern oysters (Crassostrea virginica) grown in the Northeastern United States. Phylogenetically, the species belongs to a major lineage of marine bacteria (the Roseobacter clade), within which Roseovarius crassostreae is the only known pathogen to be isolated in laboratory culture. The objective of the current study was to determine the location and nature of R. crassostreae interactions with oysters affected by juvenile oyster disease (JOD). Scanning electron microscopy of diseased individuals revealed abundant colonization of the inner shell surfaces by bacteria which were morphologically similar to R. crassostreae. The same types of cells were also observed on and within layers of host-derived conchiolin on the inner valves. Most bacterial cells were alive as determined by the use of a fluorescent viability stain. Further, most were clearly attached at the cell poles, which is consistent with the ability of R. crassostreae to express polar fimbriae. When material from the pallial fluid, soft tissue and inner valve surfaces was cultured, the highest numbers of R. crassostreae were recovered from the inner valves. These samples also contained the greatest abundance of R. crassostreae as a percentage of total colonies. Cloning and sequencing of 16S rRNA genes provided culture-independent evidence of the numerical dominance of R. crassostreae among the bacterial consortia associated with the inner shell surfaces of JOD-affected animals. The ability of R. crassostreae to colonize shell and conchiolin is consistent with the described JOD-pathology and may aid the bacteria in avoiding hemocyte-mediated killing. PMID:17931651

  18. Systemic cytokine signaling via IL-17 in smokers with obstructive pulmonary disease: a link to bacterial colonization?

    PubMed Central

    Andelid, Kristina; Tengvall, Sara; Andersson, Anders; Levänen, Bettina; Christenson, Karin; Jirholt, Pernilla; Åhrén, Christina; Qvarfordt, Ingemar; Ekberg-Jansson, Ann; Lindén, Anders

    2015-01-01

    We examined whether systemic cytokine signaling via interleukin (IL)-17 and growth-related oncogene-α (GRO-α) is impaired in smokers with obstructive pulmonary disease including chronic bronchitis (OPD-CB). We also examined how this systemic cytokine signaling relates to bacterial colonization in the airways of the smokers with OPD-CB. Currently smoking OPD-CB patients (n=60, corresponding to Global initiative for chronic Obstructive Lung Disease [GOLD] stage I–IV) underwent recurrent blood and sputum sampling over 60 weeks, during stable conditions and at exacerbations. We characterized cytokine protein concentrations in blood and bacterial growth in sputum. Asymptomatic smokers (n=10) and never-smokers (n=10) were included as control groups. During stable clinical conditions, the protein concentrations of IL-17 and GRO-α were markedly lower among OPD-CB patients compared with never-smoker controls, whereas the asymptomatic smoker controls displayed intermediate concentrations. Notably, among OPD-CB patients, colonization by opportunistic pathogens was associated with markedly lower IL-17 and GRO-α, compared with colonization by common respiratory pathogens or oropharyngeal flora. During exacerbations in the OPD-CB patients, GRO-α and neutrophil concentrations were increased, whereas protein concentrations and messenger RNA for IL-17 were not detectable in a reproducible manner. In smokers with OPD-CB, systemic cytokine signaling via IL-17 and GRO-α is impaired and this alteration may be linked to colonization by opportunistic pathogens in the airways. Given the potential pathogenic and therapeutic implications, these findings deserve to be validated in new and larger patient cohorts. PMID:25848245

  19. Inducible expression of p50 from TMV for increased resistance to bacterial crown gall disease in tobacco.

    PubMed

    Niemeyer, Julia; Ruhe, Jonas; Machens, Fabian; Stahl, Dietmar J; Hehl, Reinhard

    2014-01-01

    The dominant tobacco mosaic virus (TMV) resistance gene N induces a hypersensitive response upon TMV infection and protects tobacco against systemic spread of the virus. It has been proposed to change disease resistance specificity by reprogramming the expression of resistance genes or their corresponding avirulence genes. To reprogramme the resistance response of N towards bacterial pathogens, the helicase domain (p50) of the TMV replicase, the avirulence gene of N, was linked to synthetic promoters 4D and 2S2D harbouring elicitor-responsive cis-elements. These promoter::p50 constructs induce local necrotic lesions on NN tobacco plants in an Agrobacterium tumefaciens infiltration assay. A tobacco genotype void of N (nn) was transformed with the promoter::p50 constructs and subsequently crossed to NN plants. Nn F1 offspring selected for the T-DNA develop normally under sterile conditions. After transfer to soil, some of the F1 plants expressing the 2S2D::p50 constructs develop spontaneous necrosis. Transgenic Nn F1 plants with 4D::p50 and 2S2D::p50 expressing constructs upregulate p50 transcription and induce local necrotic lesions in an A. tumefaciens infiltration assay. When leaves and stems of Nn F1 offspring harbouring promoter::p50 constructs are infected with oncogenic A. tumefaciens C58, transgenic lines harbouring the 2S2D::p50 construct induce necrosis and completely lack tumor development. These results demonstrate a successful reprogramming of the viral N gene response against bacterial crown gall disease and highlight the importance of achieving tight regulation of avirulence gene expression and the control of necrosis in the presence of the corresponding resistance gene. PMID:23955710

  20. On the Remote Sensing of Foliar Nitrogen in Plants

    NASA Astrophysics Data System (ADS)

    Ollinger, S. V.; Lepine, L. C.; Martin, M.; Wicklein, H. F.; Sullivan, F. B.

    2012-12-01

    The concentration of nitrogen (N) in foliage is central to numerous biogeochemical processes and can serve as an indicator of carbon assimilation, species composition and linkages between terrestrial and aquatic ecosystems. Efforts to detect foliar N via remote sensing began decades ago and have been continually improved using a variety of methods and sensors. Despite this, the use of foliar N in regional- to global-scale analyses has lagged, in part because we lack instruments that provide applicable data at broad scales and because there is still no consensus on the spectral properties needed and the mechanisms that underlie foliar N detection. Here, we review the history of foliar N detection--from early laboratory based approaches to proposed methods using planned future sensors--and discuss recent findings that relate foliar N to broadband spectral features as well as high spectral resolution data. We also discuss recently revealed relations among foliar N and total shortwave albedo and address criticisms that have been directed at the use of remote sensing for foliar N detection. Our analysis is based on a combination of models and data collected over a wide range of North American research sites. Findings are presented in relation to both current and planned future sensors.

  1. Remote sensing of foliar biochemistry with a terrestrial laser scanner

    NASA Astrophysics Data System (ADS)

    Eitel, J.; Vierling, L. A.; Long, D. S.

    2011-12-01

    Foliar biochemistry provides important information about the physiological status of plants. Several different tools and techniques have been developed to infer plant biochemistry (such as state and change of foliar nitrogen (N) and chlorophyll) using remote sensing. However, few techniques allow accurate mapping of foliar biochemistry in 3-dimensions at a sub-cm level. Scanning laser technology is available that measures the x,y,z location of each reflected laser pulse in addition to the intensity of the reflected laser light within a mm-scale ground instantaneous field of view at a very high sampling rate (up to 50,000 points sec-1 in this study). We examined the ability to quantify foliar N of spring wheat (Triticum aestivum L.) and chlorophyll content of two broadleaf tree species saplings (Quercus macrocarpa and Acer saccharum) using a green (532 nm) terrestrial laser scanner. The return intensity of the reflected green laser light was significantly correlated with foliar N concentration of wheat (r2 = 0.68) and the foliar chlorophyll content (r2 = 0.77) of the broadleaf saplings. The results indicate that laser scanners are useful to obtain spatially explicit estimates of foliar biochemistry.

  2. Multilocus variable-number tandem-repeat genotyping of Renibacterium salmoninarum, a bacterium causing bacterial kidney disease in salmonid fish

    PubMed Central

    2013-01-01

    Background Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a bacterial disease of fish, which is both geographically widespread and difficult to control. Previously, application of various molecular typing methods has failed to reliably discriminate between R. salmoninarum isolates originating from different host species and geographic areas. The current study aimed to utilize multilocus variable number tandem repeats (VNTR) to investigate inter-strain variation of R. salmoninarum to establish whether host-specific populations exist in Atlantic salmon and rainbow trout respectively. Such information would be valuable in risk assessment of transmission of R. salmoninarum in a multispecies aquaculture environment. Results The present analysis utilizing sixteen VNTRs distinguished 17 different haplotypes amongst 41 R. salmoninarum isolates originating from Atlantic salmon and rainbow trout in Scotland, Norway and the US. The VNTR typing system revealed two well supported groups of R. salmoninarum haplotypes. The first group included R. salmoninarum isolates originating from both Atlantic salmon and rainbow trout circulating in Scottish and Norwegian aquaculture, in addition to the type strain ATCC33209T originating from Chinook salmon in North America. The second group comprised isolates found exclusively in Atlantic salmon, of mainly wild origin, including isolates NCIB1114 and NCIB1116 associated with the original Dee disease in Scotland. Conclusions The present study confirmed that VNTR analysis can be successfully applied to discriminate R. salmoninarum strains. There was no clear distinction between isolates originating from Atlantic salmon and rainbow trout as several haplotypes in group 1 clustered together R. salmoninarum isolates from both species. These findings indicate a potential exchange of pathogens between Atlantic salmon and rainbow trout in Scottish and Norwegian aquaculture during the last 20 years. In a scenario of

  3. Bacterial Antagonists, Zoospore Inoculum Retention Time, and Potato Cultivar Influence Pink Rot Disease Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pink rot of potato, primarily incited by Phytophthora erythroseptica, is a disease of importance in many potato growing regions of the world including North America. The principal mode of entry by the pathogen into tubers in storage is via wounds or eyes; surfaces that theoretically could be protec...

  4. Antibacterial Activity of Cinnamaldehyde and Estragole Extracted from Plant Essential Oils against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit

    PubMed Central

    Song, Yu-Rim; Choi, Min-Seon; Choi, Geun-Won; Park, Il-Kwon; Oh, Chang-Sik

    2016-01-01

    Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs) originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant antibacterial activity by only the liquid culture assay, while cinnamaldehyde exhibited antibacterial activity by both assays. The minimum inhibitory concentrations (MICs) of estragole and cinnamaldehyde by the liquid culture assay were 1,250 and 2,500 ppm, respectively. The MIC of cinnamaldehyde by the vapor diffusion assay was 5,000 ppm. Based on the formation of clear zones or the decrease of optical density caused by these compounds, they might kill the bacterial cells and this feature might be useful for managing the bacterial canker disease in kiwifruit. PMID:27493612

  5. Antibacterial Activity of Cinnamaldehyde and Estragole Extracted from Plant Essential Oils against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit.

    PubMed

    Song, Yu-Rim; Choi, Min-Seon; Choi, Geun-Won; Park, Il-Kwon; Oh, Chang-Sik

    2016-08-01

    Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs) originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant antibacterial activity by only the liquid culture assay, while cinnamaldehyde exhibited antibacterial activity by both assays. The minimum inhibitory concentrations (MICs) of estragole and cinnamaldehyde by the liquid culture assay were 1,250 and 2,500 ppm, respectively. The MIC of cinnamaldehyde by the vapor diffusion assay was 5,000 ppm. Based on the formation of clear zones or the decrease of optical density caused by these compounds, they might kill the bacterial cells and this feature might be useful for managing the bacterial canker disease in kiwifruit. PMID:27493612

  6. The gut microbial endocrine organ: bacterially derived signals driving cardiometabolic diseases.

    PubMed

    Brown, J Mark; Hazen, Stanley L

    2015-01-01

    The human gastrointestinal tract is home to trillions of bacteria, which vastly outnumber host cells in the body. Although generally overlooked in the field of endocrinology, gut microbial symbionts organize to form a key endocrine organ that converts nutritional cues from the environment into hormone-like signals that impact both normal physiology and chronic disease in the human host. Recent evidence suggests that several gut microbial-derived products are sensed by dedicated host receptor systems to alter cardiovascular disease (CVD) progression. In fact, gut microbial metabolism of dietary components results in the production of proatherogenic circulating factors that act through a meta-organismal endocrine axis to impact CVD risk. Whether pharmacological interventions at the level of the gut microbial endocrine organ will reduce CVD risk is a key new question in the field of cardiovascular medicine. Here we discuss the opportunities and challenges that lie ahead in targeting meta-organismal endocrinology for CVD prevention. PMID:25587655

  7. The Gut Microbial Endocrine Organ: Bacterially-Derived Signals Driving Cardiometabolic Diseases

    PubMed Central

    Brown, J. Mark; Hazen, Stanley L.

    2015-01-01

    The human gastrointestinal tract is home to trillions of bacteria, which vastly outnumber host cells in the body. Although generally overlooked in the field of endocrinology, gut microbial symbionts organize to form a key endocrine organ that convert nutritional cues from the environment into hormone-like signals that impact both normal physiology and chronic disease in the human host. Recent evidence suggests that several gut microbial-derived products are sensed by dedicated host receptor systems to alter cardiovascular disease (CVD) progression. In fact, gut microbial metabolism of dietary components results in the production of proatherogenic circulating factors that act through a meta-organismal endocrine axis to impact CVD risk. Whether pharmacological interventions at the level of the gut microbial endocrine organ will reduce CVD risk is a key new question in the field of cardiovascular medicine. Here we discuss the opportunities and challenges that lie ahead in targeting meta-organismal endocrinology for CVD prevention. PMID:25587655

  8. Demodectic Mange, Dermatophilosis, and other parasitic and bacterial dermatologic diseases in free-ranging white-tailed deer (Odocoileus virginianus) in the United States from 1975-2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The white-tailed deer (Odocoileus virginianus) is a common and widespread North American game species. To evaluate the incidence, clinical manifestations, demography, and pathology of bacterial and parasitic dermatologic diseases in white-tailed deer in the southeastern United States, we retrospecti...

  9. Draft Genome Sequence of Two Strains of Xanthomonas arboricola Isolated from Prunus persica Which Are Dissimilar to Strains That Cause Bacterial Spot Disease on Prunus spp.

    PubMed

    Garita-Cambronero, Jerson; Palacio-Bielsa, Ana; López, María M; Cubero, Jaime

    2016-01-01

    The draft genome sequences of two strains of Xanthomonas arboricola, isolated from asymptomatic peach trees in Spain, are reported here. These strains are avirulent and do not belong to the same phylogroup as X. arboricola pv. pruni, a causal agent of bacterial spot disease of stone fruits and almonds. PMID:27609931

  10. Registration of Great Northern Common Bean Cultivar NE1-06-12 with Enhanced Disease Resistance to Common Bacterial Blight and Bean Rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Great northern common bean (Phaseolus vulgaris L.) cultivar NE1-06-12, developed by the University of Nebraska Agricultural Research Division and released in 2008, was bred specifically for enhanced resistance to common bacterial blight, a major disease of common bean caused by the seed borne bacter...

  11. Flavobacterium branchiophilum and F. succinicans associated with bacterial gill disease in rainbow trout Oncorhynchus mykiss (Walbaum) in water recirculation aquaculture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Raised rainbow trout Oncorhynchus mykiss in six replicated water recirculation aquaculture systems (WRAS), and manipulated environmental conditions to promote bacterial gill disease (BGD). For each episode of BGD, gill tissue was sampling from affected fish, unaffected fish within the same WRAS, and...

  12. Artifically inserting a reticuloendotheliosis virus long terminal repeat into a bacterial artificial chromosome clone of Marek's disease virus (MDV) alters expression of nearby MDV genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The long terminal repeat (LTR) sequence of reticuloendotheliosis virus (REV) was inserted into the very virulent Marek’s disease virus (MDV) Md5 bacterial artificial chromosome clone. The insertion site was nearly identical to the REV LTR that was naturally inserted into the JM/102W strain of MDV fo...

  13. Evaluation of genome-enabled selection for bacterial cold water disease resistance using progeny performance data in Rainbow Trout: Insights on genotyping methods and genomic prediction models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic losses in salmonid aquaculture, and traditional family-based breeding programs aimed at improving BCWD resistance have been limited to exploiting only between-family variation. We used genomic selection (GS) models to predict genomic br...

  14. ELISA-Based Segregation of Adult Spring Chinook Salmon for Control of Bacterial Kidney Disease, Annual Report FY 1989.

    SciTech Connect

    Kaattari, Stephen L.; Winton, James R.

    1989-12-01

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a serious disease of salmonid fish worldwide. The disease has a major impact on spring chinook salmon populations in the Columbia River system. There is strong evidence that R. safmoninarum can be transmitted from parent to progeny, and therefore culling of gametes from infected parents should obviate this mode of transmission. This report presents the results from the first year of our four year study to investigate segregation of broodstock as a tool for controlling BKD. The segregations will use Enzyme-Linked Immunosorbent Assays (ELISAs) as detection systems to identify, in tissues of infected fish, proteins produced by R. salmoninarum. A first step in the development of the described detection systems was the optimization of the production of important antigenic proteins from R. salmoninarum. Different culture media were qualitatively and quantitatively evaluated for their ability to support production of cellular and soluble proteins. The major factor affecting antigen quality was the presence and absence of calf serum. Media components and R. salmoninarum growth products could not be separated during harvest of proteins from the cultures containing serum. This caused problems with the quantitation of actual bacterial proteins in the preparation. Thus media without serum is currently employed. Two independent ELISA techniques for the identification of infected parents were examined. One technique is based on polyclonal antisera produced in rabbits and the second is based on mouse monoclonal antibodies (Mabs). To develop the latter system, several Mabs against a major R. salmoninarum antigenic protein were produced. These Mabs were used for the detection of R. salmoninarum antigens in infected fish and also to characterize proteins produced by the bacterium. Both ELISAs were deemed suitable for the segregation of parents into the high and low BKD groups required for this study. An

  15. Common mechanisms involved in Alzheimer's disease and type 2 diabetes: a key role of chronic bacterial infection and inflammation

    PubMed Central

    Miklossy, Judith; McGeer, Patrick L.

    2016-01-01

    Strong epidemiologic evidence and common molecular mechanisms support an association between Alzheimer's disease (AD) and type 2-diabetes. Local inflammation and amyloidosis occur in both diseases and are associated with periodontitis and various infectious agents. This article reviews the evidence for the presence of local inflammation and bacteria in type 2 diabetes and discusses host pathogen interactions in chronic inflammatory disorders. Chlamydophyla pneumoniae, Helicobacter pylori and spirochetes are demonstrated in association with dementia and brain lesions in AD and islet lesions in type 2 diabetes. The presence of pathogens in host tissues activates immune responses through Toll-like receptor signaling pathways. Evasion of pathogens from complement-mediated attack results in persistent infection, inflammation and amyloidosis. Amyloid beta and the pancreatic amyloid called amylin bind to lipid bilayers and produce Ca(2+) influx and bacteriolysis. Similarly to AD, accumulation of amylin deposits in type 2 diabetes may result from an innate immune response to chronic bacterial infections, which are known to be associated with amyloidosis. Further research based on an infectious origin of both AD and type 2 diabetes may lead to novel treatment strategies. PMID:26961231

  16. Cloning of a very virulent plus, 686 strain of Marek's disease virus as a bacterial artificial chromosome.

    PubMed

    Reddy, Sanjay M; Sun, Aijun; Khan, Owais A; Lee, Lucy F; Lupiani, Blanca

    2013-06-01

    Bacterial artificial chromosome (BAC) vectors were first developed to facilitate propagation and manipulation of large DNA fragments. This technology was later used to clone full-length genomes of large DNA viruses to study viral gene function. Marek's disease virus (MDV) is a highly oncogenic herpesvirus that causes rapid induction of T-cell lymphomas in chickens. Based on the virus's ability to cause disease in vaccinated chickens, MDV strains are classified into pathotypes, with the most virulent strains belonging to the very virulent plus (vv+) pathotype. Here we report the construction of BAC clones of 686 (686-BAC), a vv+ strain of MDV. Transfection of DNA isolated from two independent clones into duck embryo fibroblasts resulted in recovery of infectious virus. Pathogenesis studies showed that the BAC-derived 686 viruses were more virulent than Md5, a vv strain of MDV. With the use of a two-step red-mediated mutagenesis process, both copies of viral interleukin 8 (vIL-8) were deleted from the MDV genome, showing that 686-BACs were amenable to mutagenesis techniques. The generation of BAC clones from a vv+ strain of MDV is a significant step toward understanding molecular basis of MDV pathogenesis. PMID:23901763

  17. Common mechanisms involved in Alzheimer's disease and type 2 diabetes: a key role of chronic bacterial infection and inflammation.

    PubMed

    Miklossy, Judith; McGeer, Patrick L

    2016-04-01

    Strong epidemiologic evidence and common molecular mechanisms support an association between Alzheimer's disease (AD) and type 2-diabetes. Local inflammation and amyloidosis occur in both diseases and are associated with periodontitis and various infectious agents. This article reviews the evidence for the presence of local inflammation and bacteria in type 2 diabetes and discusses host pathogen interactions in chronic inflammatory disorders. Chlamydophyla pneumoniae, Helicobacter pylori and spirochetes are demonstrated in association with dementia and brain lesions in AD and islet lesions in type 2 diabetes. The presence of pathogens in host tissues activates immune responses through Toll-like receptor signaling pathways. Evasion of pathogens from complement-mediated attack results in persistent infection, inflammation and amyloidosis. Amyloid beta and the pancreatic amyloid called amylin bind to lipid bilayers and produce Ca(2+) influx and bacteriolysis. Similarly to AD, accumulation of amylin deposits in type 2 diabetes may result from an innate immune response to chronic bacterial infections, which are known to be associated with amyloidosis. Further research based on an infectious origin of both AD and type 2 diabetes may lead to novel treatment strategies. PMID:26961231

  18. Plant Ribosomal Proteins, RPL12 and RPL19, Play a Role in Nonhost Disease Resistance against Bacterial Pathogens.

    PubMed

    Nagaraj, Satish; Senthil-Kumar, Muthappa; Ramu, Vemanna S; Wang, Keri; Mysore, Kirankumar S

    2015-01-01

    Characterizing the molecular mechanism involved in nonhost disease resistance is important to understand the adaptations of plant-pathogen interactions. In this study, virus-induced gene silencing (VIGS)-based forward genetics screen was utilized to identify genes involved in nonhost resistance in Nicotiana benthamiana. Genes encoding ribosomal proteins, RPL12 and RPL19, were identified in the screening. These genes when silenced in N. benthamiana caused a delay in nonhost bacteria induced hypersensitive response (HR) with concurrent increase in nonhost bacterial multiplication. Arabidopsis mutants of AtRPL12 and AtRPL19 also compromised nonhost resistance. The studies on NbRPL12 and NbRPL19 double silenced plants suggested that both RPL12 and RPL19 act in the same pathway to confer nonhost resistance. Our work suggests a role for RPL12 and RPL19 in nonhost disease resistance in N. benthamiana and Arabidopsis. In addition, we show that these genes also play a minor role in basal resistance against virulent pathogens. PMID:26779226

  19. Plant Ribosomal Proteins, RPL12 and RPL19, Play a Role in Nonhost Disease Resistance against Bacterial Pathogens

    PubMed Central

    Nagaraj, Satish; Senthil-Kumar, Muthappa; Ramu, Vemanna S.; Wang, Keri; Mysore, Kirankumar S.

    2016-01-01

    Characterizing the molecular mechanism involved in nonhost disease resistance is important to understand the adaptations of plant-pathogen interactions. In this study, virus-induced gene silencing (VIGS)-based forward genetics screen was utilized to identify genes involved in nonhost resistance in Nicotiana benthamiana. Genes encoding ribosomal proteins, RPL12 and RPL19, were identified in the screening. These genes when silenced in N. benthamiana caused a delay in nonhost bacteria induced hypersensitive response (HR) with concurrent increase in nonhost bacterial multiplication. Arabidopsis mutants of AtRPL12 and AtRPL19 also compromised nonhost resistance. The studies on NbRPL12 and NbRPL19 double silenced plants suggested that both RPL12 and RPL19 act in the same pathway to confer nonhost resistance. Our work suggests a role for RPL12 and RPL19 in nonhost disease resistance in N. benthamiana and Arabidopsis. In addition, we show that these genes also play a minor role in basal resistance against virulent pathogens. PMID:26779226

  20. Salmonella enterica serovar Typhimurium-induced placental inflammation and not bacterial burden correlates with pathology and fatal maternal disease.

    PubMed

    Chattopadhyay, Anindita; Robinson, Nirmal; Sandhu, Jagdeep K; Finlay, B Brett; Sad, Subash; Krishnan, Lakshmi

    2010-05-01

    Food-borne infections caused by Salmonella enterica species are increasing globally, and pregnancy poses a high risk. Pregnant mice rapidly succumb to S. enterica serovar Typhimurium infection. To determine the mechanisms involved, we addressed the role of inflammation and bacterial burden in causing placental and systemic disease. In vitro, choriocarcinoma cells were a highly conducive niche for intracellular S. Typhimurium proliferation. While infection of mice with S. Typhimurium wild-type (WT) and mutant (Delta aroA and Delta invA) strains led to profound pathogen proliferation and massive burden within placental cells, only the virulent WT S. Typhimurium infection evoked total fetal loss and adverse host outcome. This correlated with substantial placental expression of granulocyte colony-stimulating factor (G-CSF), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) and increased serum inflammatory cytokines/chemokines, such as G-CSF, IL-6, CCL1, and KC, evoked by WT S. Typhimurium infection. In contrast, infection with high doses of S. Typhimurium Delta aroA, despite causing massive placental infection, resulted in reduced inflammatory cellular and cytokine response. While S. Typhimurium WT bacteria were dispersed in large numbers across all regions of the placenta, including the deeper labyrinth trophoblast, S. Typhimurium Delta aroA bacteria localized primarily to the decidua. This correlated with the widespread placental necrosis accompanied by neutrophil infiltration evoked by the S. Typhimurium WT bacteria. Thus, the ability of Salmonella to localize to deeper layers of the placenta and the nature of inflammation triggered by the pathogen, rather than bacterial burden, profoundly influenced placental integrity and host survival. PMID:20194592

  1. Development of a Vaccine for Bacterial Kidney Disease in Salmon, 1984 Annual Report.

    SciTech Connect

    Kaattari, Stephen L.

    1985-06-01

    The data presented here demonstrate that there is some variability to the antigenic structure of KDB. Although gel filtration of all antigenic preparations revealed a wide range of sizes for antigens, resolution on a denaturing gel revealed relatively few protein bands and immunological assays revealed the same (3) low number of antigens. It is of particular interest that there seems to be a protein of 60 kd in all preparations, but that there are not larger individual molecular species. This, in turn indicates that the larger molecular weight species detected in gel filtration are most likely aggregates or membrane fragments composed of a lower molecular weight subunit. Use of ultrafiltration of KDM-2 medium appears to be successful in eliminating contamination of high molecular weight material found in KDM-2. There appears to be no alteration in the number of soluble antigens produced by growth in either medium, nor in the number of proteins, as detected by SDS-PAGE. However, soluble antigens isolated from UF-KDM-2 does appear to have greater heterogeneity in their isoelectric focusing (IEF) patterns than those from UF-KDM-2. Also, although there does appear to be an extended lag period in KDB growth on UF-KDM-2, there is no alteration in final O.D. or wet weight of cells. Thus, it appears that UF-KDM-2 may be an alternate medium for those wishing to isolate purified bacterial proteins or antigens. ELISA assays have been developed for the detection of soluble KDB antigens. This system is currently being developed as a sensitive measure of the presence of soluble antigen in serum and tissues of fish. Such a sensitive assay may also allow for the detection of KD+ spawners by the testing of ovarian fluid or serum. ELISA assays have also been developed to detect antibodies to soluble and cellular antigens of KDB. These systems have been proven successful in the detection of rabbit and murine monoclonal antibodies against KDB antigens. Future work will develop the use

  2. Selective neutralization of a bacterial enterotoxin by serum immunoglobulin A in response to mucosal disease.

    PubMed Central

    Johnson, S; Sypura, W D; Gerding, D N; Ewing, S L; Janoff, E N

    1995-01-01

    One-third of convalescent-phase serum samples (6 of 18) from patients with Clostridium difficle-associated diarrhea demonstrated neutralization of the clostridial enterotoxin, toxin A. Although appreciable amounts of toxin A-specific immunoglobulin G (IgG) and IgA were present in these sera, the ability to neutralize the cytotoxic activity of toxin A on OTF9-63 cells in vitro was confined to the IgA fraction and the IgA1 subclass in serum samples from all six patients. In contrast to the patients with C. difficile diarrhea, this activity was present in both the IgA and IgG fractions in sera from two C. difficile-infected patients without diarrhea, one of whom presented with a splenic abscess. Sera and purified IgA which neutralized the cytotoxicity of toxin A on OTF9-63 cell cultures in vitro also neutralized the enterotoxicity of toxin A in rabbit ileal loops in vivo. This activity was not Fc dependent, since IgA retained neutralizing activity after pepsin digestion and F(ab')2 purification. The transition from nonneutralizing toxin A-specific IgA in the acute-phase sera to neutralizing specific IgA in the convalescent-phase sera was accompanied by a shift from a polymeric to a predominantly monomeric form of specific IgA. However, the neutralizing activity in convalescent-phase sera was present as both monomeric and polymeric IgA. Convalescent-phase sera from other patients with C. difficile diarrhea that failed to neutralize toxin A also failed to produce a predominantly monomeric-form specific IgA response. We conclude that serum IgA, not IgG, characteristically neutralizes toxin A in patients with C. difficile diarrhea who develop neutralizing systemic responses. This neutralization of an enteric bacterial toxin is a unique and selective role for serum IgA which provides a novel functional link between the systemic and mucosal immune systems. PMID:7622244

  3. ELISA-Based Segregation of Adult Spring Chinook Salmon for Control of Bacterial Kidney Disease: Annual Report 1991.

    SciTech Connect

    Kaattari, Stephen L.

    1993-02-01

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum (RS), a serious disease of salmonid fish worldwide. The disease has a major impact on spring chinook salmon populations in the Columbia River system. There is strong evidence that RS can be transmitted from parent to progeny, and segregation of progeny based on levels of antigen detected in adult fish may obviate this mode of transmission. Results are presented from the third year of a four year study to investigate segregation of broodstock as a tool for controlling BKD. Segregation of adult fish infected with RS has been achieved using enzyme-linked immunosorbent assays (ELlSAs) optimized in the first and second year of this project. Gametes from both 1990 and 1991 broodstock, either injected with erythromycin or receiving no antibiotic injection were successfully segregated into groups having either high or low levels of the RS soluble antigen. Offspring have been monitored every three months from the 1990 broodstock and are being monitored from the 1991 broodstock. Antigen levels in the offspring from the 1990 segregation experiment at Marion Forks Hatchery were low and clinical BKD was not observed in any of the juvenile fish. At Carson National Fish Hatchery, antigen levels were also low in fish which were sampled December 1990 through July 1991. Total mortality was low throughout these sampling periods. An increase in mortality was observed in November-December 1991, and preliminary evidence suggests that motality may have been due BKD. The epizootic appears to have equally effected both offspring from high and low RS antigen level parents. Antigen levels in moribund fish are being examined to confirm the prevalence of RS infection.

  4. Review of antimicrobial therapy of selected bacterial diseases in broiler chickens in Canada

    PubMed Central

    Agunos, Agnes; Léger, Dave; Carson, Carolee

    2012-01-01

    This paper reviews common therapeutic applications of antimicrobials in broiler chicken production in relation to Canadian guidelines, surveillance data, and emerging public health concerns about antimicrobial use (AMU). Escherichia coli, Clostridium perfringens, and Staphylococcus spp., were reviewed because of their animal health and economic significance. Enterococcus cecorum and Salmonella were included because of their importance in antimicrobial resistance (AMR) surveillance. This review identified that i) antimicrobials are available in Canada to treat infections by these agents, but may be through over the counter or extra-label use, ii) prevalence rates for these diseases are unknown, iii) antimicrobial use estimates in broilers are lacking, and iv) AMR has emerged in clinical isolates, though data are very sparse. This review highlights the need for surveillance of AMU and AMR in broiler chickens in Canada. PMID:23729827

  5. A comparison of culture-dependent and culture-independent techniques used to characterize bacterial communities on healthy and white plague-diseased corals of the Montastraea annularis species complex

    NASA Astrophysics Data System (ADS)

    Cook, G. M.; Rothenberger, J. P.; Sikaroodi, M.; Gillevet, P. M.; Peters, E. C.; Jonas, R. B.

    2013-06-01

    Diseases of hermatypic corals pose a global threat to coral reefs, and investigations of bacterial communities associated with healthy corals and those exhibiting signs of disease are necessary for proper diagnosis. One disease, commonly called white plague (WP), is characterized by acute tissue loss. This investigation compared the bacterial communities associated with healthy coral tissue ( N = 15), apparently healthy tissue on WP-diseased colonies ( N = 15), and WP-diseased tissues ( N = 15) from Montastraea annularis (species complex) colonies inhabiting a Bahamian reef. Aliquots of sediment ( N = 15) and water ( N = 15) were also obtained from the proximity of each coral colony sampled. Samples for culture-dependent analyses were inoculated onto one-half strength Marine Agar (½ MA) and Thiosulfate Citrate Bile Salts Sucrose Agar to quantify the culturable communities. Length heterogeneity PCR (LH-PCR) of the 16S rRNA gene characterized the bacterial operational taxonomic units (OTU) associated with lesions on corals exhibiting signs of a white plague-like disease as well as apparently healthy tissue from diseased and non-diseased conspecifics. Analysis of Similarity was conducted on the LH-PCR fingerprints, which indicated no significant difference in the composition of bacterial communities associated with apparently healthy and diseased corals. Comparisons of the 16S rRNA gene amplicons from cultured bacterial colonies (½ MA; N = 21) with all amplicons obtained from the whole coral-associated bacterial community indicated ≥39 % of coral-associated bacterial taxa could be cultured. Amplicons from these bacterial cultures matched amplicons from the whole coral-associated bacterial community that, when combined, accounted for >70 % total bacterial abundance. An OTU with the same amplicon length as Aurantimonas coralicida (313.1 bp), the reported etiological agent of WPII, was detected in relatively low abundance (<0.1 %) on all tissue types. These findings

  6. Molecular mechanisms of foliar water uptake in a desert tree.

    PubMed

    Yan, Xia; Zhou, Maoxian; Dong, Xicun; Zou, Songbing; Xiao, Honglang; Ma, Xiao-Fei

    2015-01-01

    Water deficits severely affect growth, particularly for the plants in arid and semiarid regions of the world. In addition to precipitation, other subsidiary water, such as dew, fog, clouds and small rain showers, may also be absorbed by leaves in a process known as foliar water uptake. With the severe scarcity of water in desert regions, this process is increasingly becoming a necessity. Studies have reported on physical and physiological processes of foliar water uptake. However, the molecular mechanisms remain less understood. As major channels for water regulation and transport, aquaporins (AQPs) are involved in this process. However, due to the regulatory complexity and functional diversity of AQPs, their molecular mechanism for foliar water uptake remains unclear. In this study, Tamarix ramosissima, a tree species widely distributed in desert regions, was investigated for gene expression patterns of AQPs and for sap flow velocity. Our results suggest that the foliar water uptake of T. ramosissima occurs in natural fields at night when the humidity is over a threshold of 85 %. The diurnal gene expression pattern of AQPs suggests that most AQP gene expressions display a circadian rhythm, and this could affect both photosynthesis and transpiration. At night, the PIP2-1 gene is also upregulated with increased relative air humidity. This gene expression pattern may allow desert plants to regulate foliar water uptake to adapt to extreme drought. This study suggests a molecular basis of foliar water uptake in desert plants. PMID:26567212

  7. Molecular mechanisms of foliar water uptake in a desert tree

    PubMed Central

    Yan, Xia; Zhou, Maoxian; Dong, Xicun; Zou, Songbing; Xiao, Honglang; Ma, Xiao-Fei

    2015-01-01

    Water deficits severely affect growth, particularly for the plants in arid and semiarid regions of the world. In addition to precipitation, other subsidiary water, such as dew, fog, clouds and small rain showers, may also be absorbed by leaves in a process known as foliar water uptake. With the severe scarcity of water in desert regions, this process is increasingly becoming a necessity. Studies have reported on physical and physiological processes of foliar water uptake. However, the molecular mechanisms remain less understood. As major channels for water regulation and transport, aquaporins (AQPs) are involved in this process. However, due to the regulatory complexity and functional diversity of AQPs, their molecular mechanism for foliar water uptake remains unclear. In this study, Tamarix ramosissima, a tree species widely distributed in desert regions, was investigated for gene expression patterns of AQPs and for sap flow velocity. Our results suggest that the foliar water uptake of T. ramosissima occurs in natural fields at night when the humidity is over a threshold of 85 %. The diurnal gene expression pattern of AQPs suggests that most AQP gene expressions display a circadian rhythm, and this could affect both photosynthesis and transpiration. At night, the PIP2-1 gene is also upregulated with increased relative air humidity. This gene expression pattern may allow desert plants to regulate foliar water uptake to adapt to extreme drought. This study suggests a molecular basis of foliar water uptake in desert plants. PMID:26567212

  8. Prediction of Foliar Nitrogen to Phosphorus Ratio Using Remote Sensing

    NASA Astrophysics Data System (ADS)

    Gokkaya, K.; Thomas, V. A.; Noland, T.; Wynne, R. H.; McCaughey, J. H.; Morrison, I.; Treitz, P. M.

    2009-12-01

    Foliar nitrogen (N) to phosphorus (P) ratio (N:P) has been used as a tool to detect nutrient limitation in a variety of ecosystems. It is usually accepted that N:P ratios less than 14 indicate N limitation and greater than 16 suggest P limitation. When the value falls between 14 and 16, the ecosystem may be limited by either N and/or P. Hyperspectral remote sensing data have been used to estimate foliar pigments and N in a variety of ecosystems, but the prediction of foliar P has been limited to only a few studies. The objective of this study is to explore the potential of hyperspectral remote sensing to predict foliar N:P ratio. A one-variable model for N:P ratio estimation was developed using hyperspectral derivative indices commonly used for chlorophyll prediction (r2= 0.57 and 0.79 for calibration and validation, respectively). A foliar N:P ratio map of the area was generated using the model. The average of estimated N:P ratio at the site was 14.3, which parallels with the theory that boreal forest ecosystems are in general N limited. The map is of diagnostic value for nutrient limitation, showing significant differences in coniferous versus deciduous areas. The results suggest that hyperspectral remote sensing can be utilized to estimate foliar N:P ratio for boreal mixedwood forests. Future work will include testing the robustness of the technique in other boreal and temperate ecosystems.

  9. Molecular community profiling reveals impacts of time, space, and disease status on the bacterial community associated with the Caribbean sponge Aplysina cauliformis.

    PubMed

    Olson, Julie B; Thacker, Robert W; Gochfeld, Deborah J

    2014-01-01

    Reports of marine sponge diseases have increased in recent years, but few etiologic agents have been identified. Aplysina red band syndrome (ARBS), a condition observed in the Caribbean sponge Aplysina cauliformis, is characterized by a rust-colored leading margin. Culture-independent methods (terminal restriction fragment length polymorphism and clone library analyses) were used to assess bacterial communities associated with healthy and ARBS-affected sponges from two locations over 2 years. Although the bacterial communities associated with healthy and ARBS-affected sponges were significantly different, the sponges maintained a core bacterial community across space, time, and health status. Ten terminal restriction fragments were shown to change significantly between sponge health conditions, with six increasing in abundance with disease and four decreasing. The prevalence of the photosymbiont Synechococcus spongiarum decreased with ARBS infection, suggesting a functional consequence of disease. After cultivating a red-pigmented Leptolyngbya strain from ARBS lesions, transmission studies were conducted to determine whether this organism was the ARBS pathogen. Despite significantly increased abundance of Leptolyngbya spp. in diseased sponges, signs of ARBS were not observed in healthy sponges following 24 days of contact with the cultured strain. Additional work with this model system is needed to increase our understanding of the dynamics of marine diseases. PMID:24112035

  10. Disease Interactions in a Shared Host Plant: Effects of Pre-Existing Viral Infection on Cucurbit Plant Defense Responses and Resistance to Bacterial Wilt Disease

    PubMed Central

    Mauck, Kerry E.; Pulido, Hannier; De Moraes, Consuelo M.; Stephenson, Andrew G.; Mescher, Mark C.

    2013-01-01

    Both biotic and abiotic stressors can elicit broad-spectrum plant resistance against subsequent pathogen challenges. However, we currently have little understanding of how such effects influence broader aspects of disease ecology and epidemiology in natural environments where plants interact with multiple antagonists simultaneously. In previous work, we have shown that healthy wild gourd plants (Cucurbita pepo ssp. texana) contract a fatal bacterial wilt infection (caused by Erwinia tracheiphila) at significantly higher rates than plants infected with Zucchini yellow mosaic virus (ZYMV). We recently reported evidence that this pattern is explained, at least in part, by reduced visitation of ZYMV-infected plants by the cucumber beetle vectors of E. tracheiphila. Here we examine whether ZYMV-infection may also directly elicit plant resistance to subsequent E. tracheiphila infection. In laboratory studies, we assayed the induction of key phytohormones (SA and JA) in single and mixed infections of these pathogens, as well as in response to the feeding of A. vittatum cucumber beetles on healthy and infected plants. We also tracked the incidence and progression of wilt disease symptoms in plants with prior ZYMV infections. Our results indicate that ZYMV-infection slightly delays the progression of wilt symptoms, but does not significantly reduce E. tracheiphila infection success. This observation supports the hypothesis that reduced rates of wilt disease in ZYMV-infected plants reflect reduced visitation by beetle vectors. We also documented consistently strong SA responses to ZYMV infection, but limited responses to E. tracheiphila in the absence of ZYMV, suggesting that the latter pathogen may effectively evade or suppress plant defenses, although we observed no evidence of antagonistic cross-talk between SA and JA signaling pathways. We did, however, document effects of E. tracheiphila on induced responses to herbivory that may influence host-plant quality for (and

  11. Disease-enhancing antibodies improve the efficacy of bacterial toxin-neutralizing antibodies

    PubMed Central

    Chow, Siu-Kei; Smith, Cameron; MacCarthy, Thomas; Pohl, Mary Ann; Bergman, Aviv; Casadevall, Arturo

    2013-01-01

    SUMMARY During infection, humoral immunity produces a polyclonal response with various immunoglobulins recognizing different epitopes within the microbe or toxin. Despite this diverse response, the biological activity of an antibody (Ab) is usually assessed by the action of a monoclonal population. We demonstrate that a combination of monoclonal antibodies (mAbs) that are individually disease-enhancing or neutralizing to Bacillus anthracis protective antigen (PA), a component of anthrax toxin, results in significantly augmented protection against the toxin. This boosted protection is Fc gamma receptor (FcγR)-dependent and involves the formation of stoichiometrically defined mAb-PA complexes that requires immunoglobulin bivalence and simultaneous interaction between PA and the two mAbs. The formation of these mAb-PA complexes inhibits PA oligomerization, resulting in protection. These data suggest that functional assessments of single Abs may inaccurately predict how the same Abs will operate in polyclonal preparations and imply that potentially therapeutic mAbs may be overlooked in single Ab screens. PMID:23601104

  12. Sulfur-oxidizing bacterial populations within cyanobacterial dominated coral disease lesions.

    PubMed

    Bourne, David G; van der Zee, Marc J J; Botté, Emmanuelle S; Sato, Yui

    2013-08-01

    This study investigated the diversity and quantitative shifts of sulfur-oxidizing bacteria (SOB) during the onset of black band disease (BBD) in corals using quantitative PCR (qPCR) and cloning approaches targeting the soxB gene, involved in sulfur oxidation. Four Montipora sp. coral colonies identified with lesions previously termed cyanobacterial patches (CP) (comprising microbial communities different from those of BBD lesions), was monitored in situ as CP developed into BBD. The overall abundance of SOB in both CP and BBD lesions were very low and near the detection limit of the qPCR assay, although consistently indicated that SOB populations decreased as the lesions transitioned from CP to BBD. Phylogenetic assessment of retrieved soxB genes showed that SOB in both CP and BBD lesions were dominated by one sequence type, representing > 70% of all soxB gene sequences and affiliated with members of the Rhodobacteraceae within the α-Proteobacteria. This study represents the first assessment targeting SOB within BBD lesions and clearly shows that SOB are not highly diverse or abundant in this complex microbial mat. The lack of oxidation of reduced sulfur compounds by SOB likely aids the accumulation of high levels of sulfide at the base of the BBD mat, a compound contributing to the pathogenicity of BBD lesions. PMID:23864565

  13. Evidence that asthma is a developmental origin disease influenced by maternal diet and bacterial metabolites.

    PubMed

    Thorburn, Alison N; McKenzie, Craig I; Shen, Sj; Stanley, Dragana; Macia, Laurence; Mason, Linda J; Roberts, Laura K; Wong, Connie H Y; Shim, Raymond; Robert, Remy; Chevalier, Nina; Tan, Jian K; Mariño, Eliana; Moore, Rob J; Wong, Lee; McConville, Malcolm J; Tull, Dedreia L; Wood, Lisa G; Murphy, Vanessa E; Mattes, Joerg; Gibson, Peter G; Mackay, Charles R

    2015-01-01

    Asthma is prevalent in Western countries, and recent explanations have evoked the actions of the gut microbiota. Here we show that feeding mice a high-fibre diet yields a distinctive gut microbiota, which increases the levels of the short-chain fatty acid, acetate. High-fibre or acetate-feeding led to marked suppression of allergic airways disease (AAD, a model for human asthma), by enhancing T-regulatory cell numbers and function. Acetate increases acetylation at the Foxp3 promoter, likely through HDAC9 inhibition. Epigenetic effects of fibre/acetate in adult mice led us to examine the influence of maternal intake of fibre/acetate. High-fibre/acetate feeding of pregnant mice imparts on their adult offspring an inability to develop robust AAD. High fibre/acetate suppresses expression of certain genes in the mouse fetal lung linked to both human asthma and mouse AAD. Thus, diet acting on the gut microbiota profoundly influences airway responses, and may represent an approach to prevent asthma, including during pregnancy. PMID:26102221

  14. Tomato mutants altered in bacterial disease resistance provide evidence for a new locus controlling pathogen recognition.

    PubMed Central

    Salmeron, J M; Barker, S J; Carland, F M; Mehta, A Y; Staskawicz, B J

    1994-01-01

    We have employed a genetic approach to study the resistance of tomato to the phytopathogenic bacterium Pseudomonas syringae pv tomato. Resistance to P. s. tomato depends upon expression of the Pto locus in tomato, which encodes a protein with similarity to serine/threonine protein kinases and recognizes pathogen strains expressing the avirulence gene avrPto. Eleven tomato mutants were isolated with altered resistance to P. s. tomato strains expressing avrPto. We identified mutations both in the Pto resistance locus and in a new locus designated Prf (for Pseudomonas resistance and fenthion sensitivity). The genetic approach allowed us to dissect the roles of these loci in signal transduction in response to pathogen attack. Lines carrying mutations in the Pto locus vary 200-fold in the degree to which they are susceptible to P. s. tomato strains expressing avrPto. The pto mutants retain sensitivity to the organophosphate insecticide fenthion; this trait segregates with Pto in genetic crosses. This result suggested that contrary to previous hypotheses, the Pto locus controls pathogen recognition but not fenthion sensitivity. Interestingly, mutations in the prf locus result in both complete susceptibility to P. s. tomato and insensitivity to fenthion, suggesting that Prf plays a role in tomato signaling in response to both pathogen elicitors and fenthion. Because pto and prf mutations do not alter recognition of Xanthomonas campestris strains expressing avrBsP, an avirulence gene recognized by all tested tomato cultivars, Prf does not play a general role in disease resistance but possibly functions specifically in resistance against P. s. tomato. Genetic analysis of F2 populations from crosses of pto and prf homozygotes indicated that the Pto and Prf loci are tightly linked. PMID:7911348

  15. BGRcast: A Disease Forecast Model to Support Decision-making for Chemical Sprays to Control Bacterial Grain Rot of Rice.

    PubMed

    Lee, Yong Hwan; Ko, Sug-Ju; Cha, Kwang-Hong; Park, Eun Woo

    2015-12-01

    A disease forecast model for bacterial grain rot (BGR) of rice, which is caused by Burkholderia glumae, was developed in this study. The model, which was named 'BGRcast', determined daily conduciveness of weather conditions to epidemic development of BGR and forecasted risk of BGR development. All data that were used to develop and validate the BGRcast model were collected from field observations on disease incidence at Naju, Korea during 1998-2004 and 2010. In this study, we have proposed the environmental conduciveness as a measure of conduciveness of weather conditions for population growth of B. glumae and panicle infection in the field. The BGRcast calculated daily environmental conduciveness, Ci , based on daily minimum temperature and daily average relative humidity. With regard to the developmental stages of rice plants, the epidemic development of BGR was divided into three phases, i.e., lag, inoculum build-up and infection phases. Daily average of Ci was calculated for the inoculum build-up phase (Cinf ) and the infection phase (Cinc ). The Cinc and Cinf were considered environmental conduciveness for the periods of inoculum build-up in association with rice plants and panicle infection during the heading stage, respectively. The BGRcast model was able to forecast actual occurrence of BGR at the probability of 71.4% and its false alarm ratio was 47.6%. With the thresholds of Cinc = 0.3 and Cinf = 0.5, the model was able to provide advisories that could be used to make decisions on whether to spray bactericide at the pre- and post-heading stage. PMID:26672893

  16. BGRcast: A Disease Forecast Model to Support Decision-making for Chemical Sprays to Control Bacterial Grain Rot of Rice

    PubMed Central

    Lee, Yong Hwan; Ko, Sug-Ju; Cha, Kwang-Hong; Park, Eun Woo

    2015-01-01

    A disease forecast model for bacterial grain rot (BGR) of rice, which is caused by Burkholderia glumae, was developed in this study. The model, which was named ‘BGRcast’, determined daily conduciveness of weather conditions to epidemic development of BGR and forecasted risk of BGR development. All data that were used to develop and validate the BGRcast model were collected from field observations on disease incidence at Naju, Korea during 1998–2004 and 2010. In this study, we have proposed the environmental conduciveness as a measure of conduciveness of weather conditions for population growth of B. glumae and panicle infection in the field. The BGRcast calculated daily environmental conduciveness, Ci, based on daily minimum temperature and daily average relative humidity. With regard to the developmental stages of rice plants, the epidemic development of BGR was divided into three phases, i.e., lag, inoculum build-up and infection phases. Daily average of Ci was calculated for the inoculum build-up phase (Cinf) and the infection phase (Cinc). The Cinc and Cinf were considered environmental conduciveness for the periods of inoculum build-up in association with rice plants and panicle infection during the heading stage, respectively. The BGRcast model was able to forecast actual occurrence of BGR at the probability of 71.4% and its false alarm ratio was 47.6%. With the thresholds of Cinc = 0.3 and Cinf = 0.5, the model was able to provide advisories that could be used to make decisions on whether to spray bactericide at the pre- and post-heading stage. PMID:26672893

  17. A comprehensive analysis of the microbial communities of healthy and diseased marine macroalgae and the detection of known and potential bacterial pathogens

    PubMed Central

    Zozaya-Valdes, Enrique; Egan, Suhelen; Thomas, Torsten

    2015-01-01

    Microorganisms are increasingly being recognized as the causative agents in the diseases of marine higher organisms, such as corals, sponges, and macroalgae. Delisea pulchra is a common, temperate red macroalga, which suffers from a bleaching disease. Two bacterial strains, Nautella italica R11 and Phaeobacter gallaeciensis LSS9, have been shown in vitro to cause bleaching symptoms, but previous work has failed to detect them during a natural bleaching event. To provide a link between in vitro observations and natural occurrences of the disease, we employ here deep-sequencing of the 16S rRNA gene to comprehensively analyze the community composition of healthy and diseased D. pulchra samples from two separate locations. We observed operational taxonomic units (OTUs) with 100% identity and coverage to the 16S RNA gene sequence of both in vitro pathogens, but only the OTU with similarity to strain LSS9 showed a statistically significant higher abundance in diseased samples. Our analysis also reveals the existence of other bacterial groups within the families Rhodobacteraceae and Flavobacteriaceae that strongly contribute to difference between diseased and healthy samples and thus these groups potentially contain novel macroalgal pathogens and/or saprophytes. Together our results provide evidence for the ecological relevance of one kind of in vitro pathogen, but also highlight the possibility that multiple opportunistic pathogens are involved in the bleaching disease of D. pulchra. PMID:25759688

  18. Circulating Bacterial-Derived DNA Fragment Level Is a Strong Predictor of Cardiovascular Disease in Peritoneal Dialysis Patients

    PubMed Central

    Szeto, Cheuk-Chun; Kwan, Bonnie Ching-Ha; Chow, Kai-Ming; Kwok, Jeffrey Sung-Shing; Lai, Ka-Bik; Cheng, Phyllis Mei-Shan; Pang, Wing-Fai; Ng, Jack Kit-Chung; Chan, Michael Ho-Ming; Lit, Lydia Choi-Wan; Leung, Chi-Bon; Li, Philip Kam-Tao

    2015-01-01

    Background Circulating bacterial DNA fragment is related to systemic inflammatory state in peritoneal dialysis (PD) patients. We hypothesize that plasma bacterial DNA level predicts cardiovascular events in new PD patients. Methods We measured plasma bacterial DNA level in 191 new PD patients, who were then followed for at least a year for the development of cardiovascular event, hospitalization, and patient survival. Results The average age was 59.3 ± 11.8 years; plasma bacterial DNA level 34.9 ± 1.5 cycles; average follow up 23.2 ± 9.7 months. At 24 months, the event-free survival was 86.1%, 69.8%, 55.4% and 30.8% for plasma bacterial DNA level quartiles I, II, III and IV, respectively (p < 0.0001). After adjusting for confounders, plasma bacterial DNA level, baseline residual renal function and malnutrition-inflammation score were independent predictors of composite cardiovascular end-point; each doubling in plasma bacterial DNA level confers a 26.9% (95% confidence interval, 13.0 – 42.5%) excess in risk. Plasma bacterial DNA also correlated with the number of hospital admission (r = -0.379, p < 0.0001) and duration of hospitalization for cardiovascular reasons (r = -0.386, p < 0.0001). Plasma bacterial DNA level did not correlate with baseline arterial pulse wave velocity (PWV), but with the change in carotid-radial PWV in one year (r = -0.238, p = 0.005). Conclusions Circulating bacterial DNA fragment level is a strong predictor of cardiovascular event, need of hospitalization, as well as the progressive change in arterial stiffness in new PD patients. PMID:26010741

  19. Molecular chaperons and co-chaperons, Hsp90, RAR1, and SGT1 negatively regulate bacterial wilt disease caused by Ralstonia solanacearum in Nicotiana benthamiana.

    PubMed

    Ito, Makoto; Ohnishi, Kouhei; Hikichi, Yasufumi; Kiba, Akinori

    2015-01-01

    Ralstonia solanacearum is the causal agent of bacterial wilt disease. To better understand the molecular mechanisms involved in interaction between Nicotiana benthamiana and R. solanacearum, we focused on Hsp90, RAR1 and SGT1. Appearances of wilt symptom were significantly suppressed in Hsp90, RAR1 and SGT1-silenced plants compared with control plants. In RAR1-silenced plants, population of R. solanacearum increased in a similar manner to control plants. In contrast, multiplication of R. solanacearum was significantly suppressed in Hsp90 and SGT1-silenced plants. In addition, expression of PR genes were increased in Hsp90 and SGT1-silenced plants challenged with R. solanacearum. Therefore, RAR1 might be required for disease development or suppression of disease tolerance. These results also suggested that Hsp90 and/or SGT1 might play an important role in suppression of plant defenses leading to disease susceptibility and disease development. PMID:25482800

  20. [Bacterial vaginosis].

    PubMed

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. PMID:27474242

  1. Use of penicillin and streptomycin to reduce spread of bacterial coldwater disease I: antibiotics in sperm extenders.

    PubMed

    Oplinger, Randall W; Wagner, Eric J

    2015-03-01

    Bacterial coldwater disease caused by Flavobacterium psychrophilum has led to the loss of significant numbers of hatchery-reared salmonids. The bacteria can be spread from parent to progeny within contaminated sperm and ovarian fluid. Methods for disinfecting ovarian fluid and unfertilized eggs are available, but methods for disinfecting sperm have not been described. In this study we determined whether sperm extenders containing a mixture of penicillin and streptomycin can be used to eliminate F. psychrophilum. In vitro trials demonstrated that when Rainbow Trout Oncorhynchus mykiss sperm is mixed with an extender, a 15-min exposure to 0.197 mg penicillin plus 0.313 mg/mL streptomycin is effective at killing the bacteria and has no effect on sperm motility. Small-scale trials showed that egg fertilization rates were not reduced when sperm held in an extender solution containing the same antibiotic mixture for 15 min was used to fertilize eggs. Production-scale trials, however, showed a roughly 18% decrease in egg fertilization rate when sperm stored in an antibiotic containing extender was used. To determine why a reduction in fertilization capacity was observed, a small-scale experiment testing the fertilization of eggs with larger quantities of sperm was performed and showed that increasing the volume of sperm used did not increase fertilization rates. Our results demonstrate that extenders containing penicillin and streptomycin can be used to disinfect sperm, especially when small quantities of eggs are fertilized, but factors negatively affecting egg fertilization and survival on a production scale still need further investigation. PMID:25581335

  2. Persistence of the bacterial pathogen Granulibacter bethesdensis in Chronic Granulomatous Disease monocytes and macrophages lacking a functional NADPH oxidase1

    PubMed Central

    Chu, Jessica; Song, Helen H.; Zarember, Kol A.; Mills, Teresa A.; Gallin, John I.

    2013-01-01

    Granulibacter bethesdensis is a Gram-negative pathogen in patients with Chronic Granulomatous Disease (CGD), a deficiency in the phagocyte NADPH oxidase. Repeated isolation of genetically identical strains from the same patient over years, and prolonged waxing and waning seropositivity in some subjects, raises the possibility of long-term persistence. G. bethesdensis resists killing by serum, CGD polymorphonuclear leukocytes (PMN), and antimicrobial peptides, indicating resistance to non-oxidative killing mechanisms. While G. bethesdensis extends the survival of PMN, persistent intracellular bacterial survival might rely on longer-lived macrophages and their precursor monocytes. Therefore, we examined phagocytic killing by primary human monocytes and monocyte-derived macrophages (MDM). Cells from both normal and CGD subjects internalized G. bethesdensis similarly. G. bethesdensis stimulated superoxide production in normal monocytes, but to a lesser degree than in normal PMN. Normal but not CGD monocytes and MDM killed G. bethesdensis and required in vitro treatment with interferon-γ (IFN-γ) to maintain this killing effect. Although in vitro IFN-γ did not enhance G. bethesdensis killing in CGD monocytes, it restricted growth in proportion to CGD PMN residual superoxide production, providing a potential method to identify patients responsive to IFN-γ therapy. In IFN-γ-treated CGD MDM, G. bethesdensis persisted for the duration of the study (7 days) without decreasing viability of the host cells. These results indicate that G. bethesdensis is highly resistant to oxygen-independent microbicides of myeloid cells, requires an intact NADPH oxidase for clearance, and can persist long-term in CGD mononuclear phagocytes, likely relating to the persistence of this microorganism in infected CGD patients. PMID:23956436

  3. Clinical, Paraclinical, and Antimicrobial Resistance Features of Community-Acquired Acute Bacterial Meningitis at a Large Infectious Diseases Ward in Tehran, Iran.

    PubMed

    Heydari, Behrooz; Khalili, Hossein; Karimzadeh, Iman; Emadi-Kochak, Hamid

    2016-01-01

    In this study demographic, clinical, paraclinical, microbiological, and therapeutic features of patients with community-acquired acute bacterial meningitis admitted to a referral center for infectious diseases in Iran, have been evaluated. Medical records of adult (> 18 years) individuals with confirmed diagnosis of community-acquired bacterial meningitis during a 4-year period were retrospectively reviewed. All required data were obtained from patients' medical charts. Available findings about antimicrobial susceptibility of isolated bacteria from CSF and/or blood were also collected. Kirby-Bauer disc diffusion method was used to determine their antimicrobial susceptibility profile. Details of medical management including antibiotic regimen, duration, patients' outcome, and possible sequelae of meningitis were recorded. The most commonly isolated microorganism from CSF or blood of patients was Streptococcus pneumonia (33.33%) followed by Neisseria meningitidis (27.78%) and Haemophilus influenza (16.67%). The most common antimicrobial regimen was ceftriaxone plus vancomycin (69.44%) followed by ceftriaxone plus vancomycin plus ampicillin (11.11%). Neurological sequelae of meningitis including cranial nerve palsy, deafness, and hemiparesis were identified in 4 (11.11%), 2 (5.56%), and 1 (2.78%) subjects, respectively. Regarding mortality, only 3 (8.33%) patients died from bacterial meningitis and the remaining 33 individuals discharged from the hospital. In conclusion, findings of the current study demonstrated that the mean incidence of acute bacterial meningitis in a referral infectious diseases ward in Iran was 9 episodes per year. The majority cases of community-acquired acute bacterial meningitis admitted to our center had negative CSF culture and classic triad of meningitis was absent in them. PMID:27610176

  4. Clinical, Paraclinical, and Antimicrobial Resistance Features of Community-Acquired Acute Bacterial Meningitis at a Large Infectious Diseases Ward in Tehran, Iran

    PubMed Central

    Heydari, Behrooz; Khalili, Hossein; Karimzadeh, Iman; Emadi-Kochak, Hamid

    2016-01-01

    In this study demographic, clinical, paraclinical, microbiological, and therapeutic features of patients with community-acquired acute bacterial meningitis admitted to a referral center for infectious diseases in Iran, have been evaluated. Medical records of adult (> 18 years) individuals with confirmed diagnosis of community-acquired bacterial meningitis during a 4-year period were retrospectively reviewed. All required data were obtained from patients’ medical charts. Available findings about antimicrobial susceptibility of isolated bacteria from CSF and/or blood were also collected. Kirby-Bauer disc diffusion method was used to determine their antimicrobial susceptibility profile. Details of medical management including antibiotic regimen, duration, patients’ outcome, and possible sequelae of meningitis were recorded. The most commonly isolated microorganism from CSF or blood of patients was Streptococcus pneumonia (33.33%) followed by Neisseria meningitidis (27.78%) and Haemophilus influenza (16.67%). The most common antimicrobial regimen was ceftriaxone plus vancomycin (69.44%) followed by ceftriaxone plus vancomycin plus ampicillin (11.11%). Neurological sequelae of meningitis including cranial nerve palsy, deafness, and hemiparesis were identified in 4 (11.11%), 2 (5.56%), and 1 (2.78%) subjects, respectively. Regarding mortality, only 3 (8.33%) patients died from bacterial meningitis and the remaining 33 individuals discharged from the hospital. In conclusion, findings of the current study demonstrated that the mean incidence of acute bacterial meningitis in a referral infectious diseases ward in Iran was 9 episodes per year. The majority cases of community-acquired acute bacterial meningitis admitted to our center had negative CSF culture and classic triad of meningitis was absent in them. PMID:27610176

  5. Detection of gene expression changes in Capsicum annuum L. leaf foliar blight caused by Phytophthora capsici Leon. using qRT-PCR and leaf discs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora capsici is responsible for multiple disease syndromes of Capsicum annuum but the resistance mechanism is still unknown. Evaluating gene expression during foliar blight can be used to identify expression patterns associated with resistance in Capsicum species. This study reports a direct...

  6. Crossreactive recognition of viral, self, and bacterial peptide ligands by human class I-restricted cytotoxic T lymphocyte clonotypes: Implications for molecular mimicry in autoimmune disease

    PubMed Central

    Misko, Ihor S.; Cross, Simone M.; Khanna, Rajiv; Elliott, Suzanne L.; Schmidt, Christopher; Pye, Stephanie J.; Silins, Sharon L.

    1999-01-01

    The immunodominant, CD8+ cytotoxic T lymphocyte (CTL) response to the HLA-B8-restricted peptide, RAKFKQLL, located in the Epstein–Barr virus immediate-early antigen, BZLF1, is characterized by a diverse T cell receptor (TCR) repertoire. Here, we show that this diversity can be partitioned on the basis of crossreactive cytotoxicity patterns involving the recognition of a self peptide—RSKFRQIV—located in a serine/threonine kinase and a bacterial peptide—RRKYKQII—located in Staphylococcus aureus replication initiation protein. Thus CTL clones that recognized the viral, self, and bacterial peptides expressed a highly restricted αβ TCR phenotype. The CTL clones that recognized viral and self peptides were more oligoclonal, whereas clones that strictly recognized the viral peptide displayed a diverse TCR profile. Interestingly, the self and bacterial peptides equally were substantially less effective than the cognate viral peptide in sensitizing target cell lysis, and also resulted only in a weak reactivation of memory CTLs in limiting dilution assays, whereas the cognate peptide was highly immunogenic. The described crossreactions show that human antiviral, CD8+ CTL responses can be shaped by peptide ligands derived from autoantigens and environmental bacterial antigens, thereby providing a firm structural basis for molecular mimicry involving class I-restricted CTLs in the pathogenesis of autoimmune disease. PMID:10051632

  7. Animal Models of Bacterial Keratitis

    PubMed Central

    Marquart, Mary E.

    2011-01-01

    Bacterial keratitis is a disease of the cornea characterized by pain, redness, inflammation, and opacity. Common causes of this disease are Pseudomonas aeruginosa and Staphylococcus aureus. Animal models of keratitis have been used to elucidate both the bacterial factors and the host inflammatory response involved in the disease. Reviewed herein are animal models of bacterial keratitis and some of the key findings in the last several decades. PMID:21274270

  8. PHYSIOLOGY AND YIELD RESPONSES OF COTTON TO FOLIAR UREA WITH NBPT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Urea is the most recommended foliar N source, due to its relatively low toxicity, quick absorption, and low cost. However, in the literature reports of yield increments with foliar urea application are not consistent. The objectives of this research were to study foliar urea assimilation in cotton...

  9. EFFECT OF FOLIAR APPLICATION OF UREA WITH NBPT ON THE PHYSIOLOGY AND YIELD OF COTTON

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Urea is the most recommended foliar N source, due to its relatively low toxicity, quick absorption, and low cost. However, reports of yield improvements with foliar urea application are not consistent. The objectives of this research were to study foliar urea assimilation in cotton and to test the ...

  10. Sorghum pathology and biotechnology - A fungal disease perspective: Part II. Anthracnose, stalk rot, and downy mildew

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar diseases and stalk rots are among the most damaging diseases of sorghum in terms of lost production potential, thus commanding considerable research time and expenditure. This review will focus on anthracnose, a fungal disease that causes both foliar symptoms and stalk rots along with the st...

  11. Evidence of Bacterial Biofilms among Infected and Hypertrophied Tonsils in Correlation with the Microbiology, Histopathology, and Clinical Symptoms of Tonsillar Diseases.

    PubMed

    Alasil, Saad Musbah; Omar, Rahmat; Ismail, Salmah; Yusof, Mohd Yasim; Dhabaan, Ghulam N; Abdulla, Mahmood Ameen

    2013-01-01

    Diseases of the tonsils are becoming more resistant to antibiotics due to the persistence of bacteria through the formation of biofilms. Therefore, understanding the microbiology and pathophysiology of such diseases represent an important step in the management of biofilm-related infections. We have isolated the microorganisms, evaluated their antimicrobial susceptibility, and detected the presence of bacterial biofilms in tonsillar specimens in correlation with the clinical manifestations of tonsillar diseases. Therefore, a total of 140 palatine tonsils were collected from 70 patients undergoing tonsillectomy at University Malaya Medical Centre. The most recovered isolate was Staphylococcus aureus (39.65%) followed by Haemophilus influenzae (18.53%). There was high susceptibility against all selected antibiotics except for cotrimoxazole. Bacterial biofilms were detected in 60% of patients and a significant percentage of patients demonstrated infection manifestation rather than obstruction. In addition, an association between clinical symptoms like snore, apnea, nasal obstruction, and tonsillar hypertrophy was found to be related to the microbiology of tonsils particularly to the presence of biofilms. In conclusion, evidence of biofilms in tonsils in correlation with the demonstrated clinical symptoms explains the recalcitrant nature of tonsillar diseases and highlights the importance of biofilm's early detection and prevention towards better therapeutic management of biofilm-related infections. PMID:24454384

  12. Identification of Fusarium virguliforme FvTox1-Interacting Synthetic Peptides for Enhancing Foliar Sudden Death Syndrome Resistance in Soybean

    PubMed Central

    Wang, Bing; Swaminathan, Sivakumar; Bhattacharyya, Madan K.

    2015-01-01

    Soybean is one of the most important crops grown across the globe. In the United States, approximately 15% of the soybean yield is suppressed due to various pathogen and pests attack. Sudden death syndrome (SDS) is an emerging fungal disease caused by Fusarium virguliforme. Although growing SDS resistant soybean cultivars has been the main method of controlling this disease, SDS resistance is partial and controlled by a large number of quantitative trait loci (QTL). A proteinacious toxin, FvTox1, produced by the pathogen, causes foliar SDS. Earlier, we demonstrated that expression of an anti-FvTox1 single chain variable fragment antibody resulted in reduced foliar SDS development in transgenic soybean plants. Here, we investigated if synthetic FvTox1-interacting peptides, displayed on M13 phage particles, can be identified for enhancing foliar SDS resistance in soybean. We screened three phage-display peptide libraries and discovered four classes of M13 phage clones displaying FvTox1-interacting peptides. In vitro pull-down assays and in vivo interaction assays in yeast were conducted to confirm the interaction of FvTox1 with these four synthetic peptides and their fusion-combinations. One of these peptides was able to partially neutralize the toxic effect of FvTox1 in vitro. Possible application of the synthetic peptides in engineering SDS resistance soybean cultivars is discussed. PMID:26709700

  13. Identification of Fusarium virguliforme FvTox1-Interacting Synthetic Peptides for Enhancing Foliar Sudden Death Syndrome Resistance in Soybean.

    PubMed

    Wang, Bing; Swaminathan, Sivakumar; Bhattacharyya, Madan K

    2015-01-01

    Soybean is one of the most important crops grown across the globe. In the United States, approximately 15% of the soybean yield is suppressed due to various pathogen and pests attack. Sudden death syndrome (SDS) is an emerging fungal disease caused by Fusarium virguliforme. Although growing SDS resistant soybean cultivars has been the main method of controlling this disease, SDS resistance is partial and controlled by a large number of quantitative trait loci (QTL). A proteinacious toxin, FvTox1, produced by the pathogen, causes foliar SDS. Earlier, we demonstrated that expression of an anti-FvTox1 single chain variable fragment antibody resulted in reduced foliar SDS development in transgenic soybean plants. Here, we investigated if synthetic FvTox1-interacting peptides, displayed on M13 phage particles, can be identified for enhancing foliar SDS resistance in soybean. We screened three phage-display peptide libraries and discovered four classes of M13 phage clones displaying FvTox1-interacting peptides. In vitro pull-down assays and in vivo interaction assays in yeast were conducted to confirm the interaction of FvTox1 with these four synthetic peptides and their fusion-combinations. One of these peptides was able to partially neutralize the toxic effect of FvTox1 in vitro. Possible application of the synthetic peptides in engineering SDS resistance soybean cultivars is discussed. PMID:26709700

  14. From plant surface to plant metabolism: the uncertain fate of foliar-applied nutrients.

    PubMed

    Fernández, Victoria; Brown, Patrick H

    2013-01-01

    The application of agrochemical sprays to the aerial parts of crop plants is an important agricultural practice world-wide. While variable effectiveness is often seen in response to foliar treatments, there is abundant evidence showing the beneficial effect of foliar fertilizers in terms of improving the metabolism, quality, and yields of crops. This mini-review is focused on the major bottlenecks associated with the uptake and translocation of foliar-applied nutrient solutions. A better understanding of the complex scenario surrounding the ultimate delivery of foliar-applied nutrients to sink cells and organs is essential for improving the effectiveness and performance of foliar fertilizers. PMID:23914198

  15. Foliar biofilms of Burkholderia pyrrocinia FP62 on geraniums

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biofilm formation on foliar surfaces is commonly associated with plants in water-saturated environments (e.g. tropics or modified environments). On most leaf surfaces bacteria are thought to reside in aggregates with limited production of an exopolysaccharide (EPS) matrix. However, the biocontrol ag...

  16. FOLIAR POTASSIUM IMPROVES CANTALOUPE MARKETABLE AND NUTRITIONAL QUALITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potassium (K) is needed to optimize both crop yield and quality. Roots, the sole source of K uptake, are poor suppliers of K during fruit crop production. This study has shown that supplementing optimal soil K with additional foliar K applications, superficially during cantaloupe fruit growth, can...

  17. Investigation of the Fusarium virguliforme fvtox1 mutants revealed that the FvTox1 toxin is involved in foliar sudden death syndrome development in soybean.

    PubMed

    Pudake, Ramesh N; Swaminathan, Sivakumar; Sahu, Binod B; Leandro, Leonor F; Bhattacharyya, Madan K

    2013-08-01

    The soil borne fungus, Fusarium virguliforme, causes sudden death syndrome (SDS) in soybean, which is a serious foliar and root rot disease. The pathogen has never been isolated from the diseased foliar tissues; phytotoxins produced by the pathogen are believed to cause foliar SDS symptoms. One of these toxins, a 13.5-kDa acidic protein named FvTox1, has been hypothesized to interfere with photosynthesis in infected soybean plants and cause foliar SDS. The objective of this study is to determine if FvTox1 is involved in foliar SDS development. We created and studied five independent knockout fvtox1 mutants to study the function of FvTox1. We conducted Agrobacterium tumefaciens-mediated transformation to accomplish homologous recombination of FvTox1 with a hygromycin B resistance gene, hph, to generate the fvtox1 mutants. Approximately 40 hygromycin-resistant transformants were obtained from 10(6) conidial spores of the F. virguliforme Mont-1 isolate when the spores were co-cultivated with the A. tumefaciens EHA105 but not with LBA4044 strain carrying a recombinant binary plasmid, in which the hph gene encoding hygromycin resistance was flanked by 5'- and 3'-end FvTox1 sequences. We observed homologous recombination-mediated integration of hph into the FvTox1 locus among five independent fvtox1 mutants. In stem-cutting assays using cut soybean seedlings fed with cell-free F. virguliforme culture filtrates, the knockout fvtox1 mutants caused chlorophyll losses and foliar SDS symptoms, which were over twofold less than those caused by the virulent F. virguliforme Mont-1 isolate. Similarly, in root inoculation assays, more than a twofold reduction in foliar SDS development and chlorophyll losses was observed among the seedlings infected with the fvtox1 mutants as compared to the seedlings infected with the wild-type Mont-1 isolate. These results suggest that FvTox1 is a major virulence factor involved in foliar SDS development in soybean. It is expected that

  18. Impact of hepatic function on serum procalcitonin for the diagnosis of bacterial infections in patients with chronic liver disease: A retrospective analysis of 324 cases.

    PubMed

    Qu, Junyan; Feng, Ping; Luo, Yan; Lü, Xiaoju

    2016-07-01

    Although procalcitonin (PCT) is a valid marker for early diagnosis of bacterial infections, it is unclear whether its accuracy in predicting bacterial infections is affected by impaired liver function. This study aimed to assess the impact of compromised liver function on the diagnostic value of PCT.This retrospective study was conducted between January 2013 and May 2015. A total of 324 patients with chronic liver disease were enrolled. Routine laboratory measurements and PCT were performed. Patients were divided into 3 groups according to clinical diagnosis: chronic hepatitis (group 1), decompensated cirrhosis (group 2), and acute-on-chronic liver failure/chronic liver failure (group 3). The correlation between PCT and liver function was analyzed. The area under the receiver operating characteristic (AUCROC) curve of PCT was analyzed according to infection status and liver function.PCT was more accurate than white blood cell count (P < 0.001) and percentage of neutrophils (P < 0.001) in detecting bacterial infections in patients with impaired liver function. In patients without infection, PCT had a moderate positive correlation with serum total bilirubin (TBIL) (r = 0.592), and a weak correlation with model for end-stage liver disease score (r = 0.483) and international normalized ratio (r = 0.389). The AUCROC and optimum thresholds of PCT and for predicting bacterial infections at different levels of TBIL were 0.907 (95% CI 0.828-0.958) and 0.38 ng/mL, respectively, for TBIL <5 mg/dL, 0.927 (95% CI 0.844-0.974) and 0.54 ng/mL (5 mg/dL ≤TBIL<10 mg/dL), 0.914 (95% CI 0.820-0.968) and 0.61 ng/mL (10 mg/dL ≤TBIL<20 mg/dL), 0.906 (95% CI 0.826-0.958) and 0.94 ng/mL (TBIL ≥20 mg/dL), respectively.This study demonstrated that PCT was a valuable marker of bacterial infection in patients with chronic liver diseases. TBIL affected PCT threshold, so different cut-offs should be used according to different TBIL values. PMID

  19. Identification of alternatives for the management of foliar nematodes in floriculture.

    PubMed

    Jagdale, Ganpati B; Grewal, Parwinder S

    2002-05-01

    The foliar nematodes, Aphelenchoides spp, have emerged as important pests of ornamentals in North America during the last decade. Due to the ban on the use of potentially toxic pesticides, there are currently no nematicides registered to manage foliar nematodes on ornamentals. Therefore, we have evaluated a biological [Burkholderia cepacia (syn Pseudomonas cepacia)], two plant products [clove (Syzygium aromaticum) extract and Nimbecidine (azadirachtin)] and twelve chemical pesticides registered for the management of insects, mites, slugs or diseases of ornamentals, against Aphelenchoides fragariae on the most popular ornamental, hosta (Hosta spp), for two consecutive years. We found ZeroTol (270 g liter-1 peroxyacetic acid), currently labeled as a broad-spectrum fungicide/algicide, to be a very potent nematicide that killed 100% of the nematodes in water suspension. It also caused over 70% reduction in A fragariae population in soil and in the leaves without any phytotoxicity. B cepacia caused 67-85% reduction in A fragariae population in leaves and 50% reduction in the soil whereas insecticidal soap caused over 72% reduction in leaves and 61% reduction in the soil. Clove extract and Nimbecidine did not show any potential for the control of A fragariae on hosta. Although all twelve chemical pesticides were effective in reducing the population of A fragariae in the soil 45 days after treatment (DAT), only diazinon 475 g liter-1 EC, trichlorfon 800 g kg-1 SP, ethoprophos 100 g kg-1 GR, oxamyl 100 g kg-1 GR and ZeroTol caused over 70% reduction in nematode population compared with the control. In the leaves, only diazinon EC, trichlorfon SP, insecticidal soap, oxamyl GR and ZeroTol consistently caused over 70% nematode population reduction compared with the control at 45 DAT in both years. Thus, only diazinon EC, trichlorfon SP, oxamyl GR and ZeroTol consistently caused over 70% reduction in nematode population both in soil and leaves. Due to the recent ban by the US

  20. Demodectic mange, dermatophilosis, and other parasitic and bacterial dermatologic diseases in free-ranging white-tailed deer (Odocoileus virginianus) in the United States from 1975 to 2012.

    PubMed

    Nemeth, N M; Ruder, M G; Gerhold, R W; Brown, J D; Munk, B A; Oesterle, P T; Kubiski, S V; Keel, M K

    2014-05-01

    The white-tailed deer (Odocoileus virginianus) is a common and widespread North American game species. To evaluate the incidence, clinical manifestations, demography, and pathology of bacterial and parasitic dermatologic diseases in white-tailed deer in the southeastern United States, we retrospectively evaluated white-tailed deer cases submitted to the Southeastern Cooperative Wildlife Disease Study from 1975 to 2012. Among 2569 deer examined, bacterial or parasitic dermatologic disease was diagnosed in 88 (3.4%) individuals, with Demodex spp (n = 37; 42.0%) and Dermatophilus congolensis (n = 19; 21.6%) as the most common causes. Demodicosis was significantly more common in deer older than 2 years and was most often detected in the fall; no statistically significant sex predilection was identified. Affected animals had patchy to generalized alopecia, often distributed over the head, neck, limbs, and trunk; microscopic lesions included epidermal crusts and cutaneous nodules with mild perifollicular, lymphoplasmacytic inflammation. Dermatophilosis was most common in males younger than 1 year that were often found dead. Crusting, erythema, and alopecia occurred on the face, ears, and distal extremities. Less commonly, infectious dermatologic diseases were associated with other bacteria (n = 13; 14.8%), fungi (n = 5; 5.7%), ectoparasites (chiggers, lice, mites, and ticks; n = 11; 12.5%), and larval nematodes (n = 7; 8.0%). Population-level effects of these diseases in white-tailed deer are likely minimal; however, due to their dramatic presentation, demodicosis, dermatophilosis, and other infectious skin diseases can be of concern to hunters and, in some cases, may have zoonotic potential. PMID:23912715

  1. Increased Risks of Spontaneous Bacterial Peritonitis and Interstitial Lung Disease in Primary Biliary Cirrhosis Patients With Concomitant Sjögren Syndrome.

    PubMed

    Chen, Chun-Ting; Tseng, Yu-Chen; Yang, Chih-Wei; Lin, Hsuan-Hwai; Chen, Peng-Jen; Huang, Tien-Yu; Shih, Yu-Lueng; Chang, Wei-Kuo; Hsieh, Tsai-Yuan; Chu, Heng-Cheng

    2016-01-01

    The incidence of Sjögren syndrome (SS) in primary biliary cirrhosis (PBC) patients is high. The influence of SS on the clinical outcomes of PBC patients, however, remains unclear. Our study retrospectively collected data on PBC-only patients and PBC patients with concomitant SS (PBC-SS) to compare the clinical differences of long-term outcomes between them.A total of 183 patients were diagnosed with PBC from January 1999 to December 2014 at our hospital. Of these, the authors excluded patients with diabetes, hypertension, advanced liver cirrhosis at initial diagnosis of PBC (Child-Turcotte-Pugh classification score of ≥7) and other liver diseases (ie, alcoholic liver disease, alpha-antitrypsin deficiency, viral hepatitis, and primary sclerosing cholangitis), and autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. Of the remaining 125 patients, 77 (61.6%) were PBC-only and 48 (38.4%) were PBC-SS patients.The mean follow-up duration was 8.76 years. During the observation period, the incidence of interstitial lung disease was higher in the PBC-SS group than in the PBC-only group (P = 0.005). The occurrence of spontaneous bacterial peritonitis was significantly different in PBC-SS patients than in PBC-only patients (P = 0.002). The overall survival was lower in PBC-SS patients than in PBC-only patients (P = 0.033). Although the incidence of hepatocellular carcinoma, end-stage renal disease, variceal bleeding, and hypothyroidism were all higher in the PBC-SS group than in the PBC-only group, the differences were not significant.Our study suggests that PBC-SS patients have a higher risk of developing interstitial lung disease and spontaneous bacterial peritonitis and have a poor prognosis. Aggressive surveillance of thyroid and pulmonary functions should therefore be performed in these patients. PMID:26765478

  2. Bacterial panicle blight resistance QTL in rice (Oryza sativa L.) and their association with resistance to other diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial panicle blight (BPB) of rice (Oryza sativa L.) occurs when the bacterium Burkholderia glumae infects and colonizes emerging and flowering panicles, causing kernels to abort. To identify quantitative trait loci (QTL) for BPB resistance, a population of 300 recombinant inbred lines (RILs) d...

  3. Previous reports of bacterial diseases on crucifers attributed to Pseuomonas syringae pv. maculicola were caused by P. cannabina pv. alisalensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas cannabina pv. alisalensis (Pca) causes bacterial blight on crucifers, which can reduce crucifer yields and result in economic losses in the US. Prior to the late 1990s Pca was not distinguished from the pepper spot pathogen of crucifers, Pseudomonas syringae pv. maculicola (Psm), althoug...

  4. Use of Penicillin and Streptomycin to Reduce Spread of Bacterial Coldwater Disease II: Efficacy of Using Antibiotics in Diluents and During Water Hardening.

    PubMed

    Oplinger, Randall W; Wagner, Eric J; Cavender, Wade

    2015-03-01

    Bacterial coldwater disease, caused by Flavobacterium psychrophilum, has lead to the loss of significant numbers of hatchery-reared salmonids. The bacteria can be spread from parent to progeny within contaminated sperm and ovarian fluid and can enter the egg during fertilization. The addition of antibiotics to diluents and water-hardening solutions could prevent the spread of the disease. In separate trials, a mixture of 0.197 mg/mL penicillin plus 0.313 mg/mL streptomycin was added to both a 0.5% sodium chloride fertilization diluent and hatchery well water during hardening. Tests showed that the addition of the antibiotics to the diluent and during up to 60 min of water hardening had no effect on the eye-up, hatch and deformity rates of Rainbow Trout Oncorhynchus mykiss eggs compared with the nonantibiotic-treated controls. Also, significant reductions in the prevalence of F. psychrophilum on the surface and inside eggs were observed when compared with controls. These results indicate that the addition of penicillin and streptomycin to diluents and during water hardening can prevent the vertical transmission of bacterial coldwater disease. PMID:25581260

  5. NDR1, a locus of Arabidopsis thaliana that is required for disease resistance to both a bacterial and a fungal pathogen.

    PubMed Central

    Century, K S; Holub, E B; Staskawicz, B J

    1995-01-01

    We have employed Arabidopsis thaliana as a model host plant to genetically dissect the molecular pathways leading to disease resistance. A. thaliana accession Col-0 is susceptible to the bacterial pathogen Pseudomonas syringae pv. tomato strain DC3000 but resistant in a race-specific manner to DC3000 carrying any one of the cloned avirulence genes avrB, avrRpm1, avrRpt2, and avrPph3. Fast-neutron-mutagenized Col-0 M2 seed was screened to identify mutants susceptible to DC3000(avrB). Disease assays and analysis of in planta bacterial growth identified one mutant, ndr1-1 (nonrace-specific disease resistance), that was susceptible to DC3000 expressing any one of the four avirulence genes tested. Interestingly, a hypersensitive-like response was still induced by several of the strains. The ndr1-1 mutation also rendered the plant susceptible to several avirulent isolates of the fungal pathogen Peronospora parasitica. Genetic analysis of ndr1-1 demonstrated that the mutation segregated as a single recessive locus, located on chromosome III. Characterization of the ndr1-1 mutation suggests that a common step exists in pathways of resistance to two unrelated pathogens. Images Fig. 1 PMID:11607554

  6. Comparative Genomic and Phenotypic Characterization of Pathogenic and Non-Pathogenic Strains of Xanthomonas arboricola Reveals Insights into the Infection Process of Bacterial Spot Disease of Stone Fruits

    PubMed Central

    Garita-Cambronero, Jerson; Palacio-Bielsa, Ana; López, María M.

    2016-01-01

    Xanthomonas arboricola pv. pruni is the causal agent of bacterial spot disease of stone fruits, a quarantinable pathogen in several areas worldwide, including the European Union. In order to develop efficient control methods for this disease, it is necessary to improve the understanding of the key determinants associated with host restriction, colonization and the development of pathogenesis. After an initial characterization, by multilocus sequence analysis, of 15 strains of X. arboricola isolated from Prunus, one strain did not group into the pathovar pruni or into other pathovars of this species and therefore it was identified and defined as a X. arboricola pv. pruni look-a-like. This non-pathogenic strain and two typical strains of X. arboricola pv. pruni were selected for a whole genome and phenotype comparative analysis in features associated with the pathogenesis process in Xanthomonas. Comparative analysis among these bacterial strains isolated from Prunus spp. and the inclusion of 15 publicly available genome sequences from other pathogenic and non-pathogenic strains of X. arboricola revealed variations in the phenotype associated with variations in the profiles of TonB-dependent transporters, sensors of the two-component regulatory system, methyl accepting chemotaxis proteins, components of the flagella and the type IV pilus, as well as in the repertoire of cell-wall degrading enzymes and the components of the type III secretion system and related effectors. These variations provide a global overview of those mechanisms that could be associated with the development of bacterial spot disease. Additionally, it pointed out some features that might influence the host specificity and the variable virulence observed in X. arboricola. PMID:27571391

  7. Comparative Genomic and Phenotypic Characterization of Pathogenic and Non-Pathogenic Strains of Xanthomonas arboricola Reveals Insights into the Infection Process of Bacterial Spot Disease of Stone Fruits.

    PubMed

    Garita-Cambronero, Jerson; Palacio-Bielsa, Ana; López, María M; Cubero, Jaime

    2016-01-01

    Xanthomonas arboricola pv. pruni is the causal agent of bacterial spot disease of stone fruits, a quarantinable pathogen in several areas worldwide, including the European Union. In order to develop efficient control methods for this disease, it is necessary to improve the understanding of the key determinants associated with host restriction, colonization and the development of pathogenesis. After an initial characterization, by multilocus sequence analysis, of 15 strains of X. arboricola isolated from Prunus, one strain did not group into the pathovar pruni or into other pathovars of this species and therefore it was identified and defined as a X. arboricola pv. pruni look-a-like. This non-pathogenic strain and two typical strains of X. arboricola pv. pruni were selected for a whole genome and phenotype comparative analysis in features associated with the pathogenesis process in Xanthomonas. Comparative analysis among these bacterial strains isolated from Prunus spp. and the inclusion of 15 publicly available genome sequences from other pathogenic and non-pathogenic strains of X. arboricola revealed variations in the phenotype associated with variations in the profiles of TonB-dependent transporters, sensors of the two-component regulatory system, methyl accepting chemotaxis proteins, components of the flagella and the type IV pilus, as well as in the repertoire of cell-wall degrading enzymes and the components of the type III secretion system and related effectors. These variations provide a global overview of those mechanisms that could be associated with the development of bacterial spot disease. Additionally, it pointed out some features that might influence the host specificity and the variable virulence observed in X. arboricola. PMID:27571391

  8. Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fish, detected by nested reverse transcription-PCR of 16S rRNA sequences.

    PubMed Central

    Magnússon, H B; Fridjónsson, O H; Andrésson, O S; Benediktsdóttir, E; Gudmundsdóttir, S; Andrésdóttir, V

    1994-01-01

    An assay based on reverse transcription and nested PCR amplification of hypervariable regions within the 16S rRNA sequence was used to specifically detect Renibacterium salmoninarum, the slowly growing causative agent of bacterial kidney disease in salmonid fish. This assay detected 1 to 10 bacteria per sample and took 1 to 2 days to perform. The assay was used to detect R. salmoninarum in ovarian fluid obtained from naturally infected fish. The assay was unreliable when it was used to examine kidney tissue. Images PMID:7529017

  9. Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fish, detected by nested reverse transcription-PCR of 16S rRNA sequences.

    PubMed

    Magnússon, H B; Fridjónsson, O H; Andrésson, O S; Benediktsdóttir, E; Gudmundsdóttir, S; Andrésdóttir, V

    1994-12-01

    An assay based on reverse transcription and nested PCR amplification of hypervariable regions within the 16S rRNA sequence was used to specifically detect Renibacterium salmoninarum, the slowly growing causative agent of bacterial kidney disease in salmonid fish. This assay detected 1 to 10 bacteria per sample and took 1 to 2 days to perform. The assay was used to detect R. salmoninarum in ovarian fluid obtained from naturally infected fish. The assay was unreliable when it was used to examine kidney tissue. PMID:7529017

  10. The iturin-like lipopeptides are essential components in the biological control arsenal of Bacillus subtilis against bacterial diseases of cucurbits.

    PubMed

    Zeriouh, Houda; Romero, Diego; Garcia-Gutierrez, Laura; Cazorla, Francisco M; de Vicente, Antonio; Perez-Garcia, Alejandro

    2011-12-01

    The antibacterial potential of four strains of Bacillus subtilis, UMAF6614, UMAF6619, UMAF6639, and UMAF8561, previously selected on the basis of their antifungal activity and efficacy against cucurbit powdery mildew, was examined. Among these strains, UMAF6614 and UMAF6639 showed the highest antibacterial activity in vitro, especially against Xanthomonas campestris pv. cucurbitae and Pectobacterium carotovorum subsp. carotovorum. These strains produced the three families of lipopeptide antibiotics known in Bacillus spp.: surfactins, iturins, and fengycins. Using thin-layer chromatography analysis and direct bioautography, the antibacterial activity could be associated with iturin lipopeptides. This result was confirmed by mutagenesis analysis using lipopeptide-defective mutants. The antibacterial activity was practically abolished in iturin-deficient mutants, whereas the fengycin mutants retained certain inhibitory capabilities. Analyses by fluorescence and transmission electron microscopy revealed the cytotoxic effect of these compounds at the bacterial plasma membrane level. Finally, biological control assays on detached melon leaves demonstrated the ability of UMAF6614 and UMAF6639 to suppress bacterial leaf spot and soft rot; accordingly, the biocontrol activity was practically abolished in mutants deficient in iturin biosynthesis. Taken together, our results highlight the potential of these B. subtilis strains as biocontrol agents against fungal and bacterial diseases of cucurbits and the versatility of iturins as antifungal and antibacterial compounds. PMID:22066902

  11. Do foliar endophytic bacteria fix nitrogen?

    NASA Astrophysics Data System (ADS)

    Kueppers, L. M.; Moyes, A. B.; Frank, C.; Pett-Ridge, J.; Carper, D.; Vandehey, N.; O'Neil, J.; Dekas, A.

    2015-12-01

    Endophytic microorganisms - bacteria and fungi that live inside healthy plant tissue - are a relatively unexplored source of functional diversity in natural ecosystems. Prior to modern sequencing technology, detecting uncultured endophytic bacteria and assessing their putative functions was challenging. However, recent work has revealed a remarkable diversity of as yet non-culturable endophytic taxa and is beginning to identify functional roles within plant microbiomes. We recently examined bacterial communities in the foliage of a long-lived, high-elevation conifer species, limber pine (Pinus flexilis), and discovered a community strongly dominated by acetic acid bacteria (Acetobacteraceae), with several taxa closely related to known nitrogen fixers. Given limber pine's status as a pioneer species that is able to grow in low fertility soils, we hypothesized that this bacterial community has a potential functional role in fixing atmospheric nitrogen, providing a source of this limiting nutrient to the host tree. We used the radioisotope 13N2 to confirm that N2 rapidly diffuses into pine needles, where it could potentially be fixed. With an acetylene reduction assay we confirmed nitrogenase enzyme activity inside excised twigs 4 times over a growing season, and estimate potential rates of N2 fixation at 0.1 nmol N2 g needle-1 hr-1. Scaled to the stand level, this N input could be on the order of ~20 mg N m-2 d-1 over a growing season. While these rates are low, the long lifespan of individual trees (~1000 years) makes them biologically meaningful. Still, measured rates of acetylene reduction and bulk 15N2 incorporation are quite variable in space and time. Much work remains to better characterize the plant-microbial interactions in this system, including the rates of nitrogen fixation and their variability over the growing season, across edaphic conditions, among host species, and through plant development; and to determine which community members are responsible

  12. Zebra chip disease severity and ‘Candidatus Liberibacter solanacearum’ titer load of the potato hosts inoculated throughout the field season

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study investigated end-of-season ‘Candidatus Liberibacter solanacearum’ (Lso) titers in potato tuber and foliar tissues inoculated at different times during the growing season. Potato plants inoculated earlier in the season expressed more severe foliar symptoms and bacterial titers when compared...

  13. Deep 16S rRNA pyrosequencing reveals a bacterial community associated with Banana Fusarium Wilt disease suppression induced by bio-organic fertilizer application.

    PubMed

    Shen, Zongzhuan; Wang, Dongsheng; Ruan, Yunze; Xue, Chao; Zhang, Jian; Li, Rong; Shen, Qirong

    2014-01-01

    Our previous work demonstrated that application of a bio-organic fertilizer (BIO) to a banana mono-culture orchard with serious Fusarium wilt disease effectively decreased the number of soil Fusarium sp. and controlled the soil-borne disease. Because bacteria are an abundant and diverse group of soil organisms that responds to soil health, deep 16 S rRNA pyrosequencing was employed to characterize the composition of the bacterial community to investigate how it responded to BIO or the application of other common composts and to explore the potential correlation between bacterial community, BIO application and Fusarium wilt disease suppression. After basal quality control, 137,646 sequences and 9,388 operational taxonomic units (OTUs) were obtained from the 15 soil samples. Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria were the most frequent phyla and comprised up to 75.3% of the total sequences. Compared to the other soil samples, BIO-treated soil revealed higher abundances of Gemmatimonadetes and Acidobacteria, while Bacteroidetes were found in lower abundance. Meanwhile, on genus level, higher abundances compared to other treatments were observed for Gemmatimonas and Gp4. Correlation and redundancy analysis showed that the abundance of Gemmatimonas and Sphingomonas and the soil total nitrogen and ammonium nitrogen content were higher after BIO application, and they were all positively correlated with disease suppression. Cumulatively, the reduced Fusarium wilt disease incidence that was seen after BIO was applied for 1-year might be attributed to the general suppression based on a shift within the bacteria soil community, including specific enrichment of Gemmatimonas and Sphingomonas. PMID:24871319

  14. Arabidopsis nonhost resistance gene PSS1 confers immunity against an oomycete and a fungal pathogen but not a bacterial pathogen that cause diseases in soybean

    PubMed Central

    2012-01-01

    Background Nonhost resistance (NHR) provides immunity to all members of a plant species against all isolates of a microorganism that is pathogenic to other plant species. Three Arabidopsis thaliana PEN (penetration deficient) genes, PEN1, 2 and 3 have been shown to provide NHR against the barley pathogen Blumeria graminis f. sp. hordei at the prehaustorial level. Arabidopsis pen1-1 mutant lacking the PEN1 gene is penetrated by the hemibiotrophic oomycete pathogen Phytophthora sojae, the causal organism of the root and stem rot disease in soybean. We investigated if there is any novel nonhost resistance mechanism in Arabidopsis against the soybean pathogen, P. sojae. Results The P.sojaesusceptible (pss) 1 mutant was identified by screening a mutant population created in the Arabidopsis pen1-1 mutant that lacks penetration resistance against the non adapted barley biotrophic fungal pathogen, Blumeria graminis f. sp. hordei. Segregation data suggested that PEN1 is not epistatic to PSS1. Responses of pss1 and pen1-1 to P. sojae invasion were distinct and suggest that PSS1 may act at both pre- and post-haustorial levels, while PEN1 acts at the pre-haustorial level against this soybean pathogen. Therefore, PSS1 encodes a new form of nonhost resistance. The pss1 mutant is also infected by the necrotrophic fungal pathogen, Fusarium virguliforme, which causes sudden death syndrome in soybean. Thus, a common NHR mechanism is operative in Arabidopsis against both hemibiotrophic oomycetes and necrotrophic fungal pathogens that are pathogenic to soybean. However, PSS1 does not play any role in immunity against the bacterial pathogen, Pseudomonas syringae pv. glycinea, that causes bacterial blight in soybean. We mapped PSS1 to a region very close to the southern telomere of chromosome 3 that carries no known disease resistance genes. Conclusions The study revealed that Arabidopsis PSS1 is a novel nonhost resistance gene that confers a new form of nonhost resistance against both

  15. No globally consistent effect of ectomycorrhizal status on foliar traits.

    PubMed

    Koele, Nina; Dickie, Ian A; Oleksyn, Jacek; Richardson, Sarah J; Reich, Peter B

    2012-11-01

    The concept that ectomycorrhizal plants have a particular foliar trait suite characterized by low foliar nutrients and high leaf mass per unit area (LMA) is widely accepted, but whether this trait suite can be generalized to all ectomycorrhizal clades is unclear. We identified 19 evolutionary clades of ectomycorrhizal plants and used a global leaf traits dataset comprising 11,466 samples across c. 3000 species to test whether there were consistent shifts in leaf nutrients or LMA with the evolution of ectomycorrhiza. There were no consistent effects of ectomycorrhizal status on foliar nutrients or LMA in the 17 ectomycorrhizal/non-ectomycorrhizal pairs for which we had sufficient data, with some ectomycorrhizal groups having higher and other groups lower nutrient status than non-ectomycorrhizal contrasts. Controlling for the woodiness of host species did not alter the results. Our findings suggest that the concepts of ectomycorrhizal plant trait suites should be re-examined to ensure that they are broadly reflective of mycorrhizal status across all evolutionary clades, rather than reflecting the traits of a few commonly studied groups, such as the Pinaceae and Fagales. PMID:22966750

  16. Subsurface Examination of a Foliar Biofilm Using Scanning Electron- and Focused-Ion-Beam Microscopy

    SciTech Connect

    Wallace, Patricia K.; Arey, Bruce W.; Mahaffee, Walt F.

    2011-08-01

    The dual beam scanning electron microscope, equipped with both a focused ion- and scanning electron- beam (FIB SEM) is a novel tool for the exploration of the subsurface structure of biological tissues. The FIB can remove a predetermined amount of material from a selected site to allow for subsurface exploration and when coupled with SEM or scanning ion- beam microscopy (SIM) could be suitable to examine the subsurface structure of bacterial biofilms on the leaf surface. The suitability of chemical and cryofixation was examined for use with the FIB SEM to examine bacterial biofilms on leaf surfaces. The biological control agent, Burkholderia pyroccinia FP62, that rapidly colonizes the leaf surface and forms biofilms, was inoculated onto geranium leaves and incubated in a greenhouse for 7 or 14 days. Cryofixation was not suitable for examination of leaf biofilms because it created a frozen layer over the leaf surface that cracked when exposed to the electron beam and the protective cap required for FIB milling could not be accurately deposited. With chemically fixed samples, it was possible to precisely FIB mill a single cross section (5 µm) or sequential cross sections from a single site without any damage to the surrounding surface. Biofilms, 7 days post-inoculation (DPI), were composed of 2 to 5 bacterial cell layers while biofilms 14 DPI ranged from 5 to greater than 30 cell layers. Empty spaces between bacteria cells in the subsurface structure were observed in biofilms 7- and 14-DPI. Sequential cross sections inferred that the empty spaces were often continuous between FP62 cells and could possibly make up a network of channels throughout the biofilm. FIB SEM was a useful tool to observe the subsurface composition of a foliar biofilm.

  17. Meta-analysis Reveals That the Genus Pseudomonas Can Be a Better Choice of Biological Control Agent against Bacterial Wilt Disease Caused by Ralstonia solanacearum

    PubMed Central

    Chandrasekaran, Murugesan; Subramanian, Dharaneedharan; Yoon, Ee; Kwon, Taehoon; Chun, Se-Chul

    2016-01-01

    Biological control agents (BCAs) from different microbial taxa are increasingly used to control bacterial wilt caused by Ralstonia solanacearum. However, a quantitative research synthesis has not been conducted on the role of BCAs in disease suppression. Therefore, the present study aimed to meta-analyze the impacts of BCAs on both Ralstonia wilt disease suppression and plant (host) growth promotion. The analysis showed that the extent of disease suppression by BCAs varied widely among studies, with effect size (log response ratio) ranging from −2.84 to 2.13. The disease incidence and severity were significantly decreased on average by 53.7% and 49.3%, respectively. BCAs inoculation also significantly increased fresh and dry weight by 34.4% and 36.1%, respectively on average. Also, BCAs inoculation significantly increased plant yield by 66%. Mean effect sizes for genus Pseudomonas sp. as BCAs were higher than for genus Bacillus spp. Among antagonists tested, P. fluorescens, P. putida, B. cereus, B. subtilis and B. amyloliquefaciens were found to be more effective in general for disease reduction. Across studies, highest disease control was found for P. fluorescens, annual plants, co-inoculation with more than one BCA, soil drench and greenhouse condition were found to be essential in understanding plant responses to R. solanacearum. Our results suggest that more efforts should be devoted to harnessing the potential beneficial effects of these antagonists, not just for plant growth promoting traits but also in mode of applications, BCAs formulations and their field studies should be considered in the future for R. solanacearum wilt disease suppression. PMID:27298597

  18. Meta-analysis Reveals That the Genus Pseudomonas Can Be a Better Choice of Biological Control Agent against Bacterial Wilt Disease Caused by Ralstonia solanacearum.

    PubMed

    Chandrasekaran, Murugesan; Subramanian, Dharaneedharan; Yoon, Ee; Kwon, Taehoon; Chun, Se-Chul

    2016-06-01

    Biological control agents (BCAs) from different microbial taxa are increasingly used to control bacterial wilt caused by Ralstonia solanacearum. However, a quantitative research synthesis has not been conducted on the role of BCAs in disease suppression. Therefore, the present study aimed to meta-analyze the impacts of BCAs on both Ralstonia wilt disease suppression and plant (host) growth promotion. The analysis showed that the extent of disease suppression by BCAs varied widely among studies, with effect size (log response ratio) ranging from -2.84 to 2.13. The disease incidence and severity were significantly decreased on average by 53.7% and 49.3%, respectively. BCAs inoculation also significantly increased fresh and dry weight by 34.4% and 36.1%, respectively on average. Also, BCAs inoculation significantly increased plant yield by 66%. Mean effect sizes for genus Pseudomonas sp. as BCAs were higher than for genus Bacillus spp. Among antagonists tested, P. fluorescens, P. putida, B. cereus, B. subtilis and B. amyloliquefaciens were found to be more effective in general for disease reduction. Across studies, highest disease control was found for P. fluorescens, annual plants, co-inoculation with more than one BCA, soil drench and greenhouse condition were found to be essential in understanding plant responses to R. solanacearum. Our results suggest that more efforts should be devoted to harnessing the potential beneficial effects of these antagonists, not just for plant growth promoting traits but also in mode of applications, BCAs formulations and their field studies should be considered in the future for R. solanacearum wilt disease suppression. PMID:27298597

  19. Carbohydrates in plant immunity and plant protection: roles and potential application as foliar sprays.

    PubMed

    Trouvelot, Sophie; Héloir, Marie-Claire; Poinssot, Benoît; Gauthier, Adrien; Paris, Franck; Guillier, Christelle; Combier, Maud; Trdá, Lucie; Daire, Xavier; Adrian, Marielle

    2014-01-01

    Increasing interest is devoted to carbohydrates for their roles in plant immunity. Some of them are elicitors of plant defenses whereas other ones act as signaling molecules in a manner similar to phytohormones. This review first describes the main classes of carbohydrates associated to plant immunity, their role and mode of action. More precisely, the state of the art about perception of "PAMP, MAMP, and DAMP (Pathogen-, Microbe-, Damage-Associated Molecular Patterns) type" oligosaccharides is presented and examples of induced defense events are provided. A particular attention is paid to the structure/activity relationships of these compounds. The role of sugars as signaling molecules, especially in plant microbe interactions, is also presented. Secondly, the potentialities and limits of foliar sprays of carbohydrates to stimulate plant immunity for crop protection against diseases are discussed, with focus on the roles of the leaf cuticle and phyllosphere microflora. PMID:25408694

  20. Carbohydrates in plant immunity and plant protection: roles and potential application as foliar sprays

    PubMed Central

    Trouvelot, Sophie; Héloir, Marie-Claire; Poinssot, Benoît; Gauthier, Adrien; Paris, Franck; Guillier, Christelle; Combier, Maud; Trdá, Lucie; Daire, Xavier; Adrian, Marielle

    2014-01-01

    Increasing interest is devoted to carbohydrates for their roles in plant immunity. Some of them are elicitors of plant defenses whereas other ones act as signaling molecules in a manner similar to phytohormones. This review first describes the main classes of carbohydrates associated to plant immunity, their role and mode of action. More precisely, the state of the art about perception of “PAMP, MAMP, and DAMP (Pathogen-, Microbe-, Damage-Associated Molecular Patterns) type” oligosaccharides is presented and examples of induced defense events are provided. A particular attention is paid to the structure/activity relationships of these compounds. The role of sugars as signaling molecules, especially in plant microbe interactions, is also presented. Secondly, the potentialities and limits of foliar sprays of carbohydrates to stimulate plant immunity for crop protection against diseases are discussed, with focus on the roles of the leaf cuticle and phyllosphere microflora. PMID:25408694

  1. Recent Advances and Understanding of Using Probiotic-Based Interventions to Restore Homeostasis of the Microbiome for the Prevention/Therapy of Bacterial Diseases.

    PubMed

    Suchodolski, Jan S; Jergens, Albert E

    2016-04-01

    The importance of the microbiome in health and disease has galvanized interest in using manipulations of the gastrointestinal ecosystem to prevent and/or combat gut bacterial infections and to restore mucosal homeostasis in patients with generalized microbial imbalances (i.e., dysbiosis), including the human inflammatory bowel diseases, Crohn's disease, and ulcerative colitis. Probiotics, prebiotics, or their combination use (i.e., synbiotics) are one mechanism for modifying the microbiota and exerting direct and indirect effects on the host immune responses and metabolomics profiles. These beneficial effects are transferred through various pathways, including the production of antimicrobial peptides, promoting the growth of beneficial microbes and enhancing immunomodulatory functions via various metabolites. While probiotic therapy has been used empirically for decades with mixed success, the recent advances in molecular and mass spectrophotometric techniques for the characterization of the complexity and diversity of the intestinal microbiome has aided in better understanding of host-microbe interactions. It is important to better understand the functional properties of the microbiome, because it is now clear that the microbiota secretes many metabolites that have a direct impact on host immune responses. This information will improve selection of the most appropriate probiotic strains that selectively target intestinal disease processes. PMID:27227298

  2. A MEQ Deleted Marek's Disease Virus Cloned as a Bacterial Artificial Chromosome is a Highly Efficacious Vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Marek’s disease virus (MDV) MEQ gene is essential for the T-cell lymphocytic infiltration of nerves and other organs seen in chickens with Marek’s disease (MD). In an earlier study, researchers used an overlapping cosmid clone library of MDV and demonstrated that deleting MEQ resulted in an exce...

  3. Cloning of a very virulent plus, 686 strain of Marek’s disease virus as a bacterial artificial chromosome.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease virus (MDV) is a highly oncogenic herpesvirus that induces rapid onset of T-cell lymphomas in chicken. It has been well established that MDV strains increase in virulence over time, possibly due to the widespread use of vaccination to control Marek’s disease. One of the most pathoge...

  4. Rice xa13 Recessive Resistance to Bacterial Blight Is Defeated by Induction of the Disease Susceptibility Gene Os-11N3[W][OA

    PubMed Central

    Antony, Ginny; Zhou, Junhui; Huang, Sheng; Li, Ting; Liu, Bo; White, Frank; Yang, Bing

    2010-01-01

    The rice (Oryza sativa) gene xa13 is a recessive resistance allele of Os-8N3, a member of the NODULIN3 (N3) gene family, located on rice chromosome 8. Os-8N3 is a susceptibility (S) gene for Xanthomonas oryzae pv oryzae, the causal agent of bacterial blight, and the recessive allele is defeated by strains of the pathogen producing any one of the type III effectors AvrXa7, PthXo2, or PthXo3, which are all members of the transcription activator-like (TAL) effector family. Both AvrXa7 and PthXo3 induce the expression of a second member of the N3 gene family, here named Os-11N3. Insertional mutagenesis or RNA-mediated silencing of Os-11N3 resulted in plants with loss of susceptibility specifically to strains of X. oryzae pv oryzae dependent on AvrXa7 or PthXo3 for virulence. We further show that AvrXa7 drives expression of Os-11N3 and that AvrXa7 interacts and binds specifically to an effector binding element within the Os-11N3 promoter, lending support to the predictive models for TAL effector binding specificity. The result indicates that variations in the TAL effector repetitive domains are driven by selection to overcome both dominant and recessive forms of resistance to bacterial blight in rice. The finding that Os-8N3 and Os-11N3 encode closely related proteins also provides evidence that N3 proteins have a specific function in facilitating bacterial blight disease. PMID:21098734

  5. Comparative Genomic Analysis of Xanthomonas axonopodis pv. citrumelo F1, Which Causes Citrus Bacterial Spot Disease, and Related Strains Provides Insights into Virulence and Host Specificity ▿ #

    PubMed Central

    Jalan, Neha; Aritua, Valente; Kumar, Dibyendu; Yu, Fahong; Jones, Jeffrey B.; Graham, James H.; Setubal, João C.; Wang, Nian

    2011-01-01

    Xanthomonas axonopodis pv. citrumelo is a citrus pathogen causing citrus bacterial spot disease that is geographically restricted within the state of Florida. Illumina, 454 sequencing, and optical mapping were used to obtain a complete genome sequence of X. axonopodis pv. citrumelo strain F1, 4.9 Mb in size. The strain lacks plasmids, in contrast to other citrus Xanthomonas pathogens. Phylogenetic analysis revealed that this pathogen is very close to the tomato bacterial spot pathogen X. campestris pv. vesicatoria 85-10, with a completely different host range. We also compared X. axonopodis pv. citrumelo to the genome of citrus canker pathogen X. axonopodis pv. citri 306. Comparative genomic analysis showed differences in several gene clusters, like those for type III effectors, the type IV secretion system, lipopolysaccharide synthesis, and others. In addition to pthA, effectors such as xopE3, xopAI, and hrpW were absent from X. axonopodis pv. citrumelo while present in X. axonopodis pv. citri. These effectors might be responsible for survival and the low virulence of this pathogen on citrus compared to that of X. axonopodis pv. citri. We also identified unique effectors in X. axonopodis pv. citrumelo that may be related to the different host range as compared to that of X. axonopodis pv. citri. X. axonopodis pv. citrumelo also lacks various genes, such as syrE1, syrE2, and RTX toxin family genes, which were present in X. axonopodis pv. citri. These may be associated with the distinct virulences of X. axonopodis pv. citrumelo and X. axonopodis pv. citri. Comparison of the complete genome sequence of X. axonopodis pv. citrumelo to those of X. axonopodis pv. citri and X. campestris pv. vesicatoria provides valuable insights into the mechanism of bacterial virulence and host specificity. PMID:21908674

  6. Comparative genomic analysis of Xanthomonas axonopodis pv. citrumelo F1, which causes citrus bacterial spot disease, and related strains provides insights into virulence and host specificity.

    PubMed

    Jalan, Neha; Aritua, Valente; Kumar, Dibyendu; Yu, Fahong; Jones, Jeffrey B; Graham, James H; Setubal, João C; Wang, Nian

    2011-11-01

    Xanthomonas axonopodis pv. citrumelo is a citrus pathogen causing citrus bacterial spot disease that is geographically restricted within the state of Florida. Illumina, 454 sequencing, and optical mapping were used to obtain a complete genome sequence of X. axonopodis pv. citrumelo strain F1, 4.9 Mb in size. The strain lacks plasmids, in contrast to other citrus Xanthomonas pathogens. Phylogenetic analysis revealed that this pathogen is very close to the tomato bacterial spot pathogen X. campestris pv. vesicatoria 85-10, with a completely different host range. We also compared X. axonopodis pv. citrumelo to the genome of citrus canker pathogen X. axonopodis pv. citri 306. Comparative genomic analysis showed differences in several gene clusters, like those for type III effectors, the type IV secretion system, lipopolysaccharide synthesis, and others. In addition to pthA, effectors such as xopE3, xopAI, and hrpW were absent from X. axonopodis pv. citrumelo while present in X. axonopodis pv. citri. These effectors might be responsible for survival and the low virulence of this pathogen on citrus compared to that of X. axonopodis pv. citri. We also identified unique effectors in X. axonopodis pv. citrumelo that may be related to the different host range as compared to that of X. axonopodis pv. citri. X. axonopodis pv. citrumelo also lacks various genes, such as syrE1, syrE2, and RTX toxin family genes, which were present in X. axonopodis pv. citri. These may be associated with the distinct virulences of X. axonopodis pv. citrumelo and X. axonopodis pv. citri. Comparison of the complete genome sequence of X. axonopodis pv. citrumelo to those of X. axonopodis pv. citri and X. campestris pv. vesicatoria provides valuable insights into the mechanism of bacterial virulence and host specificity. PMID:21908674

  7. Different bacterial communities in heat and gamma irradiation treated replant disease soils revealed by 16S rRNA gene analysis - contribution to improved aboveground apple plant growth?

    PubMed

    Yim, Bunlong; Winkelmann, Traud; Ding, Guo-Chun; Smalla, Kornelia

    2015-01-01

    Replant disease (RD) severely affects apple production in propagation tree nurseries and in fruit orchards worldwide. This study aimed to investigate the effects of soil disinfection treatments on plant growth and health in a biotest in two different RD soil types under greenhouse conditions and to link the plant growth status with the bacterial community composition at the time of plant sampling. In the biotest performed we observed that the aboveground growth of apple rootstock M26 plants after 8 weeks was improved in the two RD soils either treated at 50°C or with gamma irradiation compared to the untreated RD soils. Total community DNA was extracted from soil loosely adhering to the roots and quantitative real-time PCR revealed no pronounced differences in 16S rRNA gene copy numbers. 16S rRNA gene-based bacterial community analysis by denaturing gradient gel electrophoresis (DGGE) and 454-pyrosequencing revealed significant differences in the bacterial community composition even after 8 weeks of plant growth. In both soils, the treatments affected different phyla but only the relative abundance of Acidobacteria was reduced by both treatments. The genera Streptomyces, Bacillus, Paenibacillus, and Sphingomonas had a higher relative abundance in both heat treated soils, whereas the relative abundance of Mucilaginibacter, Devosia, and Rhodanobacter was increased in the gamma-irradiated soils and only the genus Phenylobacterium was increased in both treatments. The increased abundance of genera with potentially beneficial bacteria, i.e., potential degraders of phenolic compounds might have contributed to the improved plant growth in both treatments. PMID:26635733

  8. [Experience of using bacterial lysate IRS 19 for the prophylaxis of the diseases of respiratory organs in organized groups].

    PubMed

    Volgin, A R; Demina, Iu V

    2005-01-01

    To solve the problem of unfavorable sanitary and epidemiological situation in diseases of respiratory organs in one of the organized groups in the Moscow region, a preparation prepared from a group of curative vaccines, IRS 19, was used. For controlling the effectiveness of its prophylactic action two groups of 250 persons were formed. As a result, morbidity rate in respiratory diseases decreased 2.5-3 times. In 1.5 months after the use of the preparation was started the coefficient of protection against the whole group of diseases of respiratory organs was 70%. PMID:16028523

  9. Temperature-mediated differences in bacterial kidney disease expression and survival in Renibacterium salmoninarum-challenged bull trout and other salmonids

    USGS Publications Warehouse

    Jones, D.T.; Moffitt, C.M.; Peters, K.K.

    2007-01-01

    Resource managers considering restoration and reconnection of watersheds to protect and enhance threatened populations of bull trout Salvelinus confluentus have little information about the consequences of bacterial kidney disease (BKD) caused by Renibacterium salmoninarum. To better understand the response of bull trout to R. salmoninarum challenge, we conducted several laboratory experiments at two water temperatures. The extent, severity, and lethality of BKD in bull trout were compared with those of similarly challenged lake trout S. namaycush, Arctic char S. alpinus, Chinook salmon Oncorhynchus tshawytscha, and rainbow trout O. mykiss. The lethal dose of bacterial cells necessary to induce 50% mortality (LD50) was 10-fold lower at the 15??C challenge than at the 9??C challenge. Of the species tested, bull trout were relatively resistant to BKD, Arctic char were the most susceptible among Salvelinus species, and Chinook salmon were the most susceptible among Oncorhynchus species tested. Mean time to death was more rapid for all fish tested at 15??C than for fish challenged at 9??C. These results suggest that infection of bull trout with BKD likely poses a low risk to successful restoration of threatened populations. ?? Copyright by the American Fisheries Society 2007.

  10. Novel components of leaf bacterial communities of field-grown tomato plants and their potential for plant growth promotion and biocontrol of tomato diseases.

    PubMed

    Romero, Fernando M; Marina, María; Pieckenstain, Fernando L

    2016-04-01

    This work aimed to characterize potentially endophytic culturable bacteria from leaves of cultivated tomato and analyze their potential for growth promotion and biocontrol of diseases caused by Botrytis cinerea and Pseudomonas syringae. Bacteria were obtained from inner tissues of surface-disinfected tomato leaves of field-grown plants. Analysis of 16S rRNA gene sequences identified bacterial isolates related to Exiguobacterium aurantiacum (isolates BT3 and MT8), Exiguobacterium spp. (isolate GT4), Staphylococcus xylosus (isolate BT5), Pantoea eucalypti (isolate NT6), Bacillus methylotrophicus (isolate MT3), Pseudomonas veronii (isolates BT4 and NT2), Pseudomonas rhodesiae (isolate BT2) and Pseudomonas cichorii (isolate NT3). After seed inoculation, BT2, BT4, MT3, MT8, NT2 and NT6 were re-isolated from leaf extracts. NT2, BT2, MT3 and NT6 inhibited growth of Botrytis cinerea and Pseudomonas syringae pv. tomato in vitro, produced antimicrobial compounds and reduced leaf damage caused by B. cinerea. Some of these isolates also promoted growth of tomato plants, produced siderophores, the auxin indole-3-acetic and solubilized inorganic phosphate. Thus, bacterial communities of leaves from field-grown tomato plants were found to harbor potentially endophytic culturable beneficial bacteria capable of antagonizing pathogenic microorganisms and promoting plant growth, which could be used as biological control agents and biofertilizers/biostimulators for promotion of tomato plant growth. PMID:26654914

  11. Development of variable number of tandem repeats typing schemes for Ralstonia solanacearum, the agent of bacterial wilt, banana Moko disease and potato brown rot.

    PubMed

    N'guessan, Carine Aya; Brisse, Sylvain; Le Roux-Nio, Anne-Claire; Poussier, Stéphane; Koné, Daouda; Wicker, Emmanuel

    2013-03-01

    Ralstonia solanacearum is an important soil borne bacterial plant pathogen causing bacterial wilt on many important crops. To better monitor epidemics, efficient tools that can identify and discriminate populations are needed. In this study, we assessed variable number of tandem repeats (VNTR) genotyping as a new tool for epidemiological surveillance of R. solanacearum phylotypes, and more specifically for the monitoring of the monomorphic ecotypes "Moko" (banana-pathogenic) and "brown rot" (potato-pathogenic under cool conditions). Screening of six R. solanacearum genome sequences lead to select 36 VNTR loci that were preliminarily amplified on 24 strains. From this step, 26 single-locus primer pairs were multiplexed, and applied to a worldwide collection of 337 strains encompassing the whole phylogenetic diversity, with revelation on a capillary-electrophoresis genotype. Four loci were monomorphic within all phylotypes and were not retained; the other loci were highly polymorphic but displayed a clear phylotype-specificity. Phylotype-specific MLVA schemes were thus defined, based on 13 loci for phylotype I, 12 loci for phylotype II, 11 loci for phylotype III and 6 for phylotype IV. MLVA typing was significantly more discriminative than egl-based sequevar typing, particularly on monomorphic "brown rot" ecotype (phylotype IIB/sequevar 1) and "Moko disease" clade 4 (Phylotype IIB/sequevar 4). Our results raise promising prospects for studies of population genetic structures and epidemiological monitoring. PMID:23376194

  12. A sensitive loop-mediated isothermal amplification (LAMP) method for detection of Renibacterium salmoninarum, causative agent of bacterial kidney disease in salmonids.

    PubMed

    Gahlawat, S K; Ellis, A E; Collet, B

    2009-06-01

    Loop-mediated isothermal amplification (LAMP) is a novel technique for nucleic acid amplification with high specificity, sensitivity and rapidity and does not require expensive equipment or reagents. In the present study, we developed and evaluated a LAMP method for the rapid detection of Renibacterium salmoninarum causing the bacterial kidney disease in salmonids. This method was more sensitive than quantitative real-time polymerase chain reaction (qPCR). Using DNA template extracted from cultured R. salmoninarum, the LAMP method gave an amplification signal from template diluted to 10(-8) while the limit of detection of qPCR was10(-7). The LAMP method was also highly specific and did not amplify DNA purified from five other Gram-positive and -negative bacterial fish pathogens. The method also worked well using extracts of macrophages infected with R. salmoninarum and kidney material from rainbow trout, which were positive for R. salmoninarum by qPCR and crude R. salmoninarum culture. There was some evidence for inhibitors of the LAMP reaction in the kidney samples, which was overcome by diluting the sample. PMID:19538642

  13. Bacterial Proteasomes

    PubMed Central

    Jastrab, Jordan B.; Darwin, K. Heran

    2015-01-01

    Interest in bacterial proteasomes was sparked by the discovery that proteasomal degradation is required for the pathogenesis of Mycobacterium tuberculosis, one of the world's deadliest pathogens. Although bacterial proteasomes are structurally similar to their eukaryotic and archaeal homologs, there are key differences in their mechanisms of assembly, activation, and substrate targeting for degradation. In this article, we compare and contrast bacterial proteasomes with their archaeal and eukaryotic counterparts, and we discuss recent advances in our understanding of how bacterial proteasomes function to influence microbial physiology. PMID:26488274

  14. Construction and characterization of a bacterial artificial chromosome library of the causal agent of Black Sigatoka fungal leaf spot disease of banana and plantain, Mycosphaerella fijiensis.

    PubMed

    Canto-Canché, Blondy; Guillén-Maldonado, Diana Karina; Peraza-Echeverría, Leticia; Conde-Ferráez, Laura; James-Kay, Andrew

    2007-05-01

    A bacterial artificial chromosome library of the causal agent of the Black Sigatoka leaf spot disease of banana and plantain, Mycosphaerella fijiensis, has been constructed using a non-sphaeroplasting technique and characterized using both homologous and heterologous probes. After first and a second size selection of PFGE-fractionated DNA, a ligation was obtained using a 1:4 molar ratio (insert:vector). One hundred random clones were analyzed, and the mean insert size was estimated to be 90 kb. The range of the insert sizes was between 40 and 160 kb. The highest percentage of inserts belonged to the range between 80 and 100 kb; 32% of the inserts had 2 or 3 internal NotI sites. This library consists of 1920 clones, if the genomic size is at least 35 Mb, then this represents 4.9 x genome equivalents, which was supported by hybridization results with homologous and heterologous probes. PMID:17827540

  15. Bacterial vaginosis.

    PubMed Central

    Spiegel, C A

    1991-01-01

    Bacterial vaginosis (BV) is the most common of the vaginitides affecting women of reproductive age. It appears to be due to an alteration in the vaginal ecology by which Lactobacillus spp., the predominant organisms in the healthy vagina, are replaced by a mixed flora including Prevotella bivia, Prevotella disiens, Porphyromonas spp., Mobiluncus spp., and Peptostreptococcus spp. All of these organisms except Mobiluncus spp. are also members of the endogenous vaginal flora. While evidence from treatment trials does not support the notion that BV is sexually transmitted, recent studies have shown an increased risk associated with multiple sexual partners. It has also been suggested that the pathogenesis of BV may be similar to that of urinary tract infections, with the rectum serving as a reservoir for some BV-associated flora. The organisms associated with BV have also been recognized as agents of female upper genital tract infection, including pelvic inflammatory disease, and the syndrome BV has been associated with adverse outcome of pregnancy, including premature rupture of membranes, chorioamnionitis, and fetal loss; postpartum endometritis; cuff cellulitis; and urinary tract infections. The mechanisms by which the BV-associated flora causes the signs of BV are not well understood, but a role for H2O2-producing Lactobacillus spp. in protecting against colonization by catalase-negative anaerobic bacteria has been recognized. These and other aspects of BV are reviewed. PMID:1747864

  16. Molecular Phylogeny, Homology Modeling, and Molecular Dynamics Simulation of Race-Specific Bacterial Blight Disease Resistance Protein (xa5) of Rice: A Comparative Agriproteomics Approach

    PubMed Central

    Dehury, Budheswar; Sahu, Mousumi; Sarma, Kishore; Sahu, Jagajjit; Sen, Priyabrata; Modi, Mahendra Kumar; Sharma, Gauri Dutta; Choudhury, Manabendra Dutta

    2013-01-01

    Abstract Rice (Oryza sativa L.), a model plant belonging to the family Poaceae, is a staple food for a majority of the people worldwide. Grown in the tropical and subtropical regions of the world, this important cereal crop is under constant and serious threat from both biotic and abiotic stresses. Among the biotic threats, Xanthomonas oryzae pv. oryzae, causing the damaging bacterial blight disease in rice, is a prominent pathogen. The xa5 gene in the host plant rice confers race-specific resistance to this pathogen. This recessive gene belongs to the Xa gene family of rice and encodes a gamma subunit of transcription factor IIA (TFIIAγ). In view of the importance of this gene in conferring resistance to the devastating disease, we reconstructed the phylogenetic relationship of this gene, developed a three-dimensional protein model, followed by long-term molecular dynamics simulation studies to gain a better understanding of the evolution, structure, and function of xa5. The modeled structure was found to fit well with the small subunit of TFIIA from human, suggesting that it may also act as a small subunit of TFIIA in rice. The model had a stable conformation in response to the atomic flexibility and interaction, when subjected to MD simulation at 20 nano second in aqueous solution. Further structural analysis of xa5 indicated that the protein retained its basic transcription factor function, suggesting that it might govern a novel pathway responsible for bacterial blight resistance. Future molecular docking studies of xa5 underway with its corresponding avirulence gene is expected to shed more direct light into plant–pathogen interactions at the molecular level and thus pave the way for richer agriproteomic insights. PMID:23758479

  17. Lipoproteins of bacterial pathogens.

    PubMed

    Kovacs-Simon, A; Titball, R W; Michell, S L

    2011-02-01

    Bacterial lipoproteins are a set of membrane proteins with many different functions. Due to this broad-ranging functionality, these proteins have a considerable significance in many phenomena, from cellular physiology through cell division and virulence. Here we give a general overview of lipoprotein biogenesis and highlight examples of the roles of lipoproteins in bacterial disease caused by a selection of medically relevant Gram-negative and Gram-positive pathogens: Mycobacterium tuberculosis, Streptococcus pneumoniae, Borrelia burgdorferi, and Neisseria meningitidis. Lipoproteins have been shown to play key roles in adhesion to host cells, modulation of inflammatory processes, and translocation of virulence factors into host cells. As such, a number of lipoproteins have been shown to be potential vaccines. This review provides a summary of some of the reported roles of lipoproteins and of how this knowledge has been exploited in some cases for the generation of novel countermeasures to bacterial diseases. PMID:20974828

  18. Gender difference in calcification diseases: is it the result of gender-specific ways of nano-bacterial expansion?

    PubMed

    Schwartsburd, P M; Agababov, R; Vainshtein, M

    2013-11-01

    Gender difference has been reported for frequency of the calcification diseases in urogenital system: according to published statistics data, they are more numerous in males. We suggest that the male increasing is due to nanobacterial infections and ways of their dissemination. There are specific gender-dependent ways for these infections which bring infection to the different target organs, namely: urinary tract, kidney, prostate in men and placenta in women. Identification of the suggested microbial pathogens and investigation of sex-determined pathways for the dissemination are the following steps to get ascertaining events of gender reasons for different calcification diseases. PMID:24018282

  19. Natural foliar variegation without costs? The case of Begonia

    PubMed Central

    Sheue, Chiou-Rong; Pao, Shang-Horng; Chien, Lee-Feng; Chesson, Peter; Peng, Ching-I

    2012-01-01

    Background and Aims Foliar variegation is recognized as arising from two major mechanisms: leaf structure and pigment-related variegation. Begonia has species with a variety of natural foliar variegation patterns, providing diverse examples of this phenomenon. The aims of this work are to elucidate the mechanisms underlying different foliar variegation patterns in Begonia and to determine their physiological consequences. Methods Six species and one cultivar of Begonia were investigated. Light and electron microscopy revealed the leaf structure and ultrastructure of chloroplasts in green and light areas of variegated leaves. Maximum quantum yields of photosystem II were measured by chlorophyll fluorescence. Comparison with a cultivar of Ficus revealed key features distinguishing variegation mechanisms. Key Results Intercellular space above the chlorenchyma is the mechanism of variegation in these Begonia. This intercellular space can be located (a) below the adaxial epidermis or (b) below the adaxial water storage tissue (the first report for any taxa), creating light areas on a leaf. In addition, chlorenchyma cell shape and chloroplast distribution within chlorenchyma cells differ between light and green areas. Chloroplasts from both areas showed dense stacking of grana and stroma thylakoid membranes. The maximum quantum yield did not differ significantly between these areas, suggesting minimal loss of function with variegation. However, the absence of chloroplasts in light areas of leaves in the Ficus cultivar led to an extremely low quantum yield. Conclusions Variegation in these Begonia is structural, where light areas are created by internal reflection between air spaces and cells in a leaf. Two forms of air space structural variegation occur, distinguished by the location of the air spaces. Both forms may have a common origin in development where dermal tissue becomes loosely connected to mesophyll. Photosynthetic functioning is retained in light areas, and

  20. Foliar anthocyanin content - Sensitivity of vegetation indices using green reflectance

    NASA Astrophysics Data System (ADS)

    Vina, A.; Gitelson, A. A.

    2009-12-01

    The amount and composition of photosynthetic and non-photosynthetic foliar pigments varies primarily as a function of species, developmental and phenological stages, and environmental stresses. Information on the absolute and relative amounts of these pigments thus provides insights onto the physiological conditions of plants and their responses to stress, and has the potential to be used for evaluating plant species composition and diversity across broad geographic regions. Anthocyanins in particular, are non-photosynthetic pigments associated with the resistance of plants to environmental stresses (e.g., drought, low soil nutrients, high radiation, herbivores, and pathogens). As they absorb radiation primarily in the green region of the electromagnetic spectrum (around 540-560 nm), broad-band vegetation indices that use this region in their formulation will respond to their presence. We evaluated the sensitivity of three vegetation indices using reflectance in the green spectral region (the green Normalized Difference Vegetation Index, gNDVI, the green Chlorophyll Index, CIg, and the Visible Atmospherically Resistant Vegetation Index, VARI) to foliar anthocyanins in five different species. For comparison purposes the widely used Normalized Difference Vegetation Index, NDVI was also evaluated. Among the four indices tested, the VARI, which uses only spectral bands in the visible region of the electromagnetic spectrum, was found to be inversely and linearly related to the relative amount of foliar anthocyanins. While this result was obtained at leaf level, it opens new possibilities for analyzing anthocyanin content across multiple scales, by means of currently operational aircraft- and spacecraft-mounted broad-band sensor systems. Further studies that evaluate the sensitivity of the VARI to the relative content of anthocyanins across space (e.g., at canopy and regional scales) and time, and its relationship with plant biodiversity and vegetation stresses, are

  1. A Multi-Omic Systems-Based Approach Reveals Metabolic Markers of Bacterial Vaginosis and Insight into the Disease

    PubMed Central

    Yeoman, Carl J.; Thomas, Susan M.; Miller, Margret E. Berg; Ulanov, Alexander V.; Torralba, Manolito; Lucas, Sarah; Gillis, Marcus; Cregger, Melissa; Gomez, Andres; Ho, Mengfei; Leigh, Steven R.; Stumpf, Rebecca; Creedon, Douglas J.; Smith, Michael A.; Weisbaum, Jon S.; Nelson, Karen E.; Wilson, Brenda A.; White, Bryan A.

    2013-01-01

    Background Bacterial vaginosis (BV) is the most common vaginal disorder of reproductive-age women. Yet the cause of BV has not been established. To uncover key determinants of BV, we employed a multi-omic, systems-biology approach, including both deep 16S rRNA gene-based sequencing and metabolomics of lavage samples from 36 women. These women varied demographically, behaviorally, and in terms of health status and symptoms. Principal Findings 16S rRNA gene-based community composition profiles reflected Nugent scores, but not Amsel criteria. In contrast, metabolomic profiles were markedly more concordant with Amsel criteria. Metabolomic profiles revealed two distinct symptomatic BV types (SBVI and SBVII) with similar characteristics that indicated disruption of epithelial integrity, but each type was correlated to the presence of different microbial taxa and metabolites, as well as to different host behaviors. The characteristic odor associated with BV was linked to increases in putrescine and cadaverine, which were both linked to Dialister spp. Additional correlations were seen with the presence of discharge, 2-methyl-2-hydroxybutanoic acid, and Mobiluncus spp., and with pain, diethylene glycol and Gardnerella spp. Conclusions The results not only provide useful diagnostic biomarkers, but also may ultimately provide much needed insight into the determinants of BV. PMID:23405259

  2. Loop-mediated isothermal amplification (LAMP) for rapid detection of Renibacterium salmoninarum, the causative agent of bacterial kidney disease.

    PubMed

    Saleh, Mona; Soliman, Hatem; El-Matbouli, Mansour

    2008-08-27

    A loop-mediated isothermal amplification (LAMP) assay was developed for rapid, specific and sensitive detection of Renibacterium salmoninarum in 1 h without thermal cycling. A fragment of R. salmoninarum p57 gene was amplified at 63 degrees C in the presence of Bst polymerase and a specially designed primer mixture. The specificity of the BKD-LAMP assay was demonstrated by the absence of any cross reaction with other bacterial strains, followed by restriction digestion of the amplified products. Detections of BKD-LAMP amplicons by visual inspection, agrose gel electrophoresis, and real-time monitoring using a turbidimeter were equivalently sensitive. The BKD-LAMP assay has the sensitivity of the nested PCR method, and 10 times the sensitivity of one-round PCR assay. The lower detection limit of BKD-LAMP and nested PCR is 1 pg genomic R. salmoninarum DNA, compared to 10 pg genomic R. salmoninarum DNA for one-round PCR assay. In comparison to other available diagnostic methods, the BKD-LAMP assay is rapid, simple, sensitive, specific, and cost effective with a high potential for field application. PMID:18924379

  3. Variations in prevalence of viral, bacterial, and rhizocephalan diseases and parasites of the blue crab (Callinectes sapidus).

    PubMed

    Rogers, Holly A; Taylor, Sabrina S; Hawke, John P; Anderson Lively, Julie A

    2015-05-01

    Prevalence of blue crab diseases and parasites has not been consistently monitored in the Gulf of Mexico. To establish current prevalence levels and to more fully understand population dynamics, commercial landing trends, and effects of future natural and anthropogenic disasters on animal health, we measured the prevalence of white spot syndrome virus (WSSV), Loxothylacus texanus, shell disease, and Vibrio spp. in blue crabs collected from Louisiana in 2013 and the beginning of 2014. We used PCR to detect WSSV and L. texanus infections, visual gross diagnosis for L. texanus externae and shell disease, and standard microbiological culture techniques and biochemical testing for Vibrio spp. We found no crabs infected with WSSV or L. texanus. Absence of L. texanus parasitization was expected based on the sampled salinities and the sampling focus on large crabs. Shell disease was present at a level of 54.8% and was most prevalent in the winter and summer and least prevalent in the spring. Vibrio spp. were found in the hemolymph of 22.3% of the crabs and prevalence varied by site, season, and sex. Additionally, three of 39 crabs tested were infected with reo-like virus. PMID:25769514

  4. Bean common bacterial blight: pathogen epiphytic life and effect of irrigation practices.

    PubMed

    Akhavan, Alireza; Bahar, Masoud; Askarian, Homa; Lak, Mohammad Reza; Nazemi, Abolfazl; Zamani, Zahra

    2013-12-01

    In recent years, bean common bacterial blight (CBB) caused by Xanthomonas axonopodis pv. phaseoli (Xap) has caused serious yield losses in several countries. CBB is considered mainly a foliar disease in which symptoms initially appear as small water-soaked spots that then enlarge and become necrotic and usually bordered by a chlorotic zone. Xap epiphytic population community has a critical role in the development of the disease and subsequent epidemics. The epiphytic population of Xap in the field has two major parts; solitary cells (potentially planktonic) and biofilms which are sources for providing and refreshing the solitary cell components. Irrigation type has a significant effect on epiphytic population of Xap. The mean epiphytic population size in the field with an overhead sprinkler irrigation system is significantly higher than populations under furrow irrigation. A significant positive correlation between the epiphytic population size of Xap and disease severity has been reported in both the overhead irrigated (r=0.64) and the furrow irrigated (r= 0.44) fields. PMID:23539532

  5. BACTERIAL WATERBORNE PATHOGENS

    EPA Science Inventory

    Bacterial pathogens are examples of classical etiological agents of waterborne disease. While these agents no longer serve as major threats to U.S. water supplies, they are still important pathogens in areas with substandard sanitation and poor water treatment facilities. In th...

  6. Bacterial leaf spot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial leaf spot has been reported in Australia (Queensland), Egypt, El Salvador, India, Japan, Nicaragua, Sudan, and the United States (Florida, Iowa, Kansas, Maryland, and Wisconsin). It occasionally causes locally severe defoliation and post-emergence damping-off and stunting. The disease is...

  7. Management practices regulate the response of Moso bamboo foliar stoichiometry to nitrogen deposition.

    PubMed

    Song, Xinzhang; Gu, Honghao; Wang, Meng; Zhou, Guomo; Li, Quan

    2016-01-01

    Moso bamboo, well known for its high growth rate, is being subjected to increasing amounts of nitrogen deposition. However, how anthropogenic management practices regulate the effects of N deposition on Moso bamboo stoichiometry remains poorly understood. We observed the effects of two years of simulated N deposition (30, 60 and 90 kg N ha(-1)yr(-1)) on the foliar stoichiometry of Moso bamboo plantations under conventional management (CM) and intensive management (IM). Young bamboo had significantly greater foliar N and P concentrations and N:P ratios than mature plants (P < 0.05). IM significantly increased the foliar N concentrations of young bamboo and P concentrations of mature bamboo but decreased mature bamboo foliar N:P ratios (P < 0.05). Nitrogen increased foliar N and P concentrations in IM bamboo plantations, but the positive effects were diminished when the addition rate exceeded 60 kg N ha(-1)yr(-1). Nitrogen increased foliar N concentrations but aggravated P deficiency in CM bamboo plantations. The positive effects of N deposition on foliar stoichiometry were influenced by management practices and bamboo growth stage. The effects of N deposition on foliar stoichiometry combined with anthropogenic management practices can influence ecosystem production, decomposition, and subsequent N and P cycles in Moso bamboo plantations. PMID:27052002

  8. Foliar deficiencies of mature southern Appalachian red spruce determined from fertilizer trials

    SciTech Connect

    Joslin, J.D.; Wolfe, M.H.

    1994-09-01

    A field fertilization study employing additions of Ca, Mg, and N to a mature red spruce (Picea rubens Sarg.) stand was conducted at a high-elevation site in southwestern Virginia. Statistically significant increases in needle weight (20% larger than controls) were observed after two growing seasons in treatments receiving Ca or Ca plus Mg. Significant foliar growth responses were accompanied by significant increases (20-60%) in foliar concentrations of Ca, Zn, Mg, and Mn in current-year and 1-yr-old needles. Both Ca and Mg addition, alone or together, appear to have alleviated antagonisms by Al towards the uptake of these four cations. Both the foliar growth response (negative) and the foliar N concentration response to N addition were nonsignificant, a response consistent with evidence for N saturation at this site. Vector analysis, correlation analyses, and literature evidence all provide support at this site for a foliar deficiency of Zn at a foliar concentration of 14 mg kg{sup -1} and for a foliar and/or root deficiency of Ca at a current-year needle concentration of 1700 mg kg{sup -1}, Foliar concentrations of Ca and Zn at or below these thresholds are common in southern Appalachian red spruce and may be related to its apparent growth decline in the higher elevations. 47 refs., 7 figs., 1 tab.

  9. Segregation of progeny of Solanum tuberosum subsp. andigena for foliar and tuber resistance to late blight.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding solely for foliar resistance to late blight without emphasis on tuber resistance has the potential to exacerbate tuber infection. Wild potato species are valuable sources of foliar and tuber blight resistance. However, most species are difficult to sexually hybridize with cultivated potat...

  10. Foliar Application of Phosphorus Has Minimal Impact on 'Pinot noir' Growth, Mycorrhizal Colonization, or Fruit Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grapevines grown in low phosphorus (P) soils typical of western Oregon vineyards may benefit from additional P applied to the canopy using foliar sprays. Alternatively, vines may be negatively affected by foliar P sprays because lower root colonization by arbuscular mycorrhizal fungi (AMF) could red...

  11. Management practices regulate the response of Moso bamboo foliar stoichiometry to nitrogen deposition

    PubMed Central

    Song, Xinzhang; Gu, Honghao; Wang, Meng; Zhou, Guomo; Li, Quan

    2016-01-01

    Moso bamboo, well known for its high growth rate, is being subjected to increasing amounts of nitrogen deposition. However, how anthropogenic management practices regulate the effects of N deposition on Moso bamboo stoichiometry remains poorly understood. We observed the effects of two years of simulated N deposition (30, 60 and 90 kg N ha−1yr−1) on the foliar stoichiometry of Moso bamboo plantations under conventional management (CM) and intensive management (IM). Young bamboo had significantly greater foliar N and P concentrations and N:P ratios than mature plants (P < 0.05). IM significantly increased the foliar N concentrations of young bamboo and P concentrations of mature bamboo but decreased mature bamboo foliar N:P ratios (P < 0.05). Nitrogen increased foliar N and P concentrations in IM bamboo plantations, but the positive effects were diminished when the addition rate exceeded 60 kg N ha−1yr−1. Nitrogen increased foliar N concentrations but aggravated P deficiency in CM bamboo plantations. The positive effects of N deposition on foliar stoichiometry were influenced by management practices and bamboo growth stage. The effects of N deposition on foliar stoichiometry combined with anthropogenic management practices can influence ecosystem production, decomposition, and subsequent N and P cycles in Moso bamboo plantations. PMID:27052002

  12. Scaling uncertainties in estimating canopy foliar maintenance respiration for black spruce ecosystems in Alaska

    USGS Publications Warehouse

    Zhang, X.; McGuire, A.D.; Ruess, R.W.

    2006-01-01

    A major challenge confronting the scientific community is to understand both patterns of and controls over spatial and temporal variability of carbon exchange between boreal forest ecosystems and the atmosphere. An understanding of the sources of variability of carbon processes at fine scales and how these contribute to uncertainties in estimating carbon fluxes is relevant to representing these processes at coarse scales. To explore some of the challenges and uncertainties in estimating carbon fluxes at fine to coarse scales, we conducted a modeling analysis of canopy foliar maintenance respiration for black spruce ecosystems of Alaska by scaling empirical hourly models of foliar maintenance respiration (Rm) to estimate canopy foliar Rm for individual stands. We used variation in foliar N concentration among stands to develop hourly stand-specific models and then developed an hourly pooled model. An uncertainty analysis identified that the most important parameter affecting estimates of canopy foliar Rm was one that describes R m at 0??C per g N, which explained more than 55% of variance in annual estimates of canopy foliar Rm. The comparison of simulated annual canopy foliar Rm identified significant differences between stand-specific and pooled models for each stand. This result indicates that control over foliar N concentration should be considered in models that estimate canopy foliar Rm of black spruce stands across the landscape. In this study, we also temporally scaled the hourly stand-level models to estimate canopy foliar Rm of black spruce stands using mean monthly temperature data. Comparisons of monthly Rm between the hourly and monthly versions of the models indicated that there was very little difference between the estimates of hourly and monthly models, suggesting that hourly models can be aggregated to use monthly input data with little loss of precision. We conclude that uncertainties in the use of a coarse-scale model for estimating canopy foliar

  13. Improvement of Basmati rice varieties for resistance to blast and bacterial blight diseases using marker assisted backcross breeding.

    PubMed

    Ellur, Ranjith K; Khanna, Apurva; Yadav, Ashutosh; Pathania, Sandeep; Rajashekara, H; Singh, Vikas K; Gopala Krishnan, S; Bhowmick, Prolay K; Nagarajan, M; Vinod, K K; Prakash, G; Mondal, Kalyan K; Singh, Nagendra K; Vinod Prabhu, K; Singh, Ashok K

    2016-01-01

    Marker assisted backcross breeding was employed to incorporate the blast resistance genes, Pi2 and Pi54 and bacterial blight (BB) resistance genes xa13 and Xa21 into the genetic background of Pusa Basmati 1121 (PB1121) and Pusa Basmati 6. Foreground selection for target gene(s) was followed by arduous phenotypic and background selection which fast-tracked the recovery of recurrent parent genome (RPG) to an extent of 95.8% in one of the near-isogenic lines (NILs) namely, Pusa 1728-23-33-31-56, which also showed high degree of resemblance to recurrent parent, PB6 in phenotype. The phenotypic selection prior to background selection provided an additional opportunity for identifying the novel recombinants viz., Pusa 1884-9-12-14 and Pusa 1884-3-9-175, superior to parental lines in terms of early maturity, higher yield and improved quality parameters. There was no significant difference between the RPG recovery estimated based on SSR or SNP markers, however, the panel of SNPs markers was considered as the better choice for background selection as it provided better genome coverage and included SNPs in the genic regions. Multi-location evaluation of NILs depicted their stable and high mean performance in comparison to the respective recurrent parents. The Pi2+Pi54 carrying NILs were effective in combating a pan-India panel of Magnaporthe oryzae isolates with high level of field resistance in northern, eastern and southern parts of India. Alongside, the PB1121-NILs and PB6-NILs carrying BB resistance genes xa13+Xa21 were resistant against Xanthomonas oryzae pv. oryzae races of north-western, southern and eastern parts of the country. Three of NILs developed in this study, have been promoted to final stage of testing during the ​Kharif 2015 in the Indian National Basmati Trial. PMID:26566849

  14. Evolution and Impact of Bacterial Drug Resistance in the Context of Cystic Fibrosis Disease and Nosocomial Settings

    PubMed Central

    Sriramulu, Dinesh

    2013-01-01

    The use of antibiotics is unavoidable in trying to treat acute infections and in the prevention and control of chronic infections. Over the years, an ever increasing number of infections has escalated the use of antibiotics, which has necessitated action against an emerging bacterial resistance. There seems to be a continuous acquisition of new resistance mechanisms among bacteria that switch niches between human, animals, and the environment. An antibiotic resistant strain emerges when it acquires the DNA that confers the added capacity needed to survive in an unusual niche. Once acquired, a new resistance mechanism evolves according to the dynamics of the microenvironment; there is then a high probability that it is transferred to other species or to an avirulent strain of the same species. A well understood model for studying emerging antibiotic resistance and its impact is Pseudomonas aeruginosa, an opportunistic pathogen which is able to cause acute and chronic infections in nosocomial settings. This bacterium has a huge genetic repertoire consisting of genes that encode both innate and acquired antibiotic resistance traits. Besides acute infections, chronic colonization of P. aeruginosa in the lungs of cystic fibrosis (CF) patients plays a significant role in morbidity and mortality. Antibiotics used in the treatment of such infections has increased the longevity of patients over the last several decades. However, emerging multidrug resistant strains and the eventual increase in the dosage of antibiotic(s) is of major concern. Though there are various infections that are treated by single/combined antibiotics, the particular case of P. aeruginosa infection in CF patients serves as a reference for understanding the impact of overuse of antibiotics and emerging antibiotic resistant strains. This mini review presents the need for judicious use of antibiotics to treat various types of infections, protecting patients and the environment, as well as achieving a

  15. Controls on foliar nutrient and aluminium concentrations in a tropical tree flora: phylogeny, soil chemistry and interactions among elements.

    PubMed

    Metali, Faizah; Abu Salim, Kamariah; Tennakoon, Kushan; Burslem, David F R P

    2015-01-01

    Foliar elemental concentrations are predictors of life-history variation and contribute to spatial patterns in biogeochemical cycling. We examined the contributions of habitat association, local soil environment, and elemental interactions to variation in foliar elemental concentrations in tropical trees using methods that account for phylogeny. We sampled top-soils and leaves of 58 tropical trees in heath forest (HF) on nutrient-poor sand and mixed dipterocarp forest (MDF) on nutrient-rich clay soils. A phylogenetic generalized least squares method was used to determine how foliar nutrient and aluminium (Al) concentrations varied in response to habitat distribution, soil chemistry and other elemental concentrations. Foliar nitrogen (N) and Al concentrations were greater for specialists of MDF than for specialists of HF, while foliar calcium (Ca) concentrations showed the opposite trend. Foliar magnesium (Mg) concentrations were lower for generalists than for MDF specialists. Foliar element concentrations were correlated with fine-scale variation in soil chemistry in phylogenetically controlled analyses across species, but there was limited within-species plasticity in foliar elemental concentrations. Among Al accumulators, foliar Al concentration was positively associated with foliar Ca and Mg concentrations, and negatively associated with foliar phosphorus (P) concentrations. The Al-accumulation trait and relationships between foliar elemental and Al concentrations may contribute to species habitat partitioning and ecosystem-level differences in biogeochemical cycles. PMID:25138655

  16. IL-27 and TGFβ mediated expansion of Th1 and adaptive regulatory T cells expressing IL-10 correlates with bacterial burden and disease severity in pulmonary tuberculosis

    PubMed Central

    Kumar, Nathella P; Moideen, Kadar; Banurekha, Vaithilingam V; Nair, Dina; Sridhar, Rathinam; Nutman, Thomas B; Babu, Subash

    2015-01-01

    CD4+ T cell expression of IL-10 is an important mechanism controlling immunity to tuberculosis (TB). To identify the CD4+ T cell subsets producing IL-10 in human TB, we enumerated the frequencies of IL-10 expressing CD4+ T cell subsets following TB—antigen stimulation of cells from individuals with pulmonary (PTB) and latent TB (LTB). We first demonstrate that TB antigens induce an expansion of IL-10 expressing Th1 (IL-10+, IFNγ+, T-bet+), Th2 (IL-10+, IL-4+, GATA-3+), Th9 (IL-10+, IL-9+, IL-4−), Th17 (IL-10+, IL-17+, IFNγ−), and natural and adaptive regulatory T cells [nTregs; IL-10+, CD4+, CD25+, Foxp3+ and aTregs; IL-10 single+, CD4+, CD25−, Foxp3−] in PTB and LTB individuals, with frequencies being significantly higher in the former. However, only Th1 cells and adaptive Tregs expressing IL-10 exhibit a positive relationship with bacterial burdens and extent of disease in PTB. Finally, we show that IL-27 and TGFβ play an important role in the regulation of IL-10+ Th cell subsets. Thus, active PTB is characterized by an IL-27 and TGFβ mediated expansion of IL-10 expressing CD4+ T cell subsets, with IL-10+ Th1 and IL-10+ aTreg cells playing a potentially pivotal role in the pathogenesis of active disease. PMID:26417443

  17. IL-27 and TGFβ mediated expansion of Th1 and adaptive regulatory T cells expressing IL-10 correlates with bacterial burden and disease severity in pulmonary tuberculosis.

    PubMed

    Kumar, Nathella P; Moideen, Kadar; Banurekha, Vaithilingam V; Nair, Dina; Sridhar, Rathinam; Nutman, Thomas B; Babu, Subash

    2015-09-01

    CD4(+) T cell expression of IL-10 is an important mechanism controlling immunity to tuberculosis (TB). To identify the CD4(+) T cell subsets producing IL-10 in human TB, we enumerated the frequencies of IL-10 expressing CD4(+) T cell subsets following TB-antigen stimulation of cells from individuals with pulmonary (PTB) and latent TB (LTB). We first demonstrate that TB antigens induce an expansion of IL-10 expressing Th1 (IL-10(+), IFNγ(+), T-bet(+)), Th2 (IL-10(+), IL-4(+), GATA-3(+)), Th9 (IL-10(+), IL-9(+), IL-4(-)), Th17 (IL-10(+), IL-17(+), IFNγ(-)), and natural and adaptive regulatory T cells [nTregs; IL-10(+), CD4(+), CD25(+), Foxp3(+) and aTregs; IL-10 single(+), CD4(+), CD25(-), Foxp3(-)] in PTB and LTB individuals, with frequencies being significantly higher in the former. However, only Th1 cells and adaptive Tregs expressing IL-10 exhibit a positive relationship with bacterial burdens and extent of disease in PTB. Finally, we show that IL-27 and TGFβ play an important role in the regulation of IL-10(+) Th cell subsets. Thus, active PTB is characterized by an IL-27 and TGFβ mediated expansion of IL-10 expressing CD4(+) T cell subsets, with IL-10(+) Th1 and IL-10(+) aTreg cells playing a potentially pivotal role in the pathogenesis of active disease. PMID:26417443

  18. Effects of sampling method on foliar δ (13)C of Leymus chinensis at different scales.

    PubMed

    Liu, Yanjie; Li, Yan; Zhang, Lirong; Xu, Xingliang; Niu, Haishan

    2015-03-01

    Stable carbon isotope composition (δ (13)C) usually shows a negative relationship with precipitation at a large scale. We hypothesized that sampling method affects foliar δ (13)C and its response pattern to precipitation. We selected 11 sites along a precipitation gradient in Inner Mongolia and collected leaves of Leymus chinensis with five or six replications repeatedly in each site from 2009 to 2011. Additionally, we collected leaves of L. chinensis separately from two types of grassland (grazed and fenced) in 2011. Foliar δ (13)C values of all samples were measured. We compared the patterns that foliar δ (13)C to precipitation among different years or different sample sizes, the differences of foliar δ (13)C between grazed and fenced grassland. Whether actual annual precipitation (AAP) or mean annual precipitation (MAP), it was strongly correlated with foliar δ (13)C every year. Significant difference was found between the slopes of foliar δ (13)C to AAP and MAP every year, among the slopes of foliar δ (13)C to AAP from 2009 to 2011. The more samples used at each site the lower and convergent P-values of the linear regression test between foliar δ (13)C and precipitation. Furthermore, there was significant lower foliar δ (13)C value in presence of grazed type than fenced type grassland. These findings provide evidence that there is significant effect of sampling method to foliar δ (13)C and its response pattern to precipitation of L. chinensis. Our results have valuable implications in methodology for future field sampling studies. PMID:25798224

  19. The Mauna Loa environmental matrix: foliar and soil nutrients

    USGS Publications Warehouse

    Vitousek, P.M.; Aplet, G.; Turner, D.; Lockwood, J.J.

    1992-01-01

    The accumulation of total carbon, nitrogen, and phosphorus in soils, available soil nutrients, and foliar nutrients in the native dominant Metrosideros polymorpha were determined across a wide elevational range on 9 lava flows on Mauna Loa, Hawai'i. The flows included a young (2800 y) a??a?? (rough surface texture) and pa??hoehoe (smooth) flow on the wet east and dry northwest side of the mountain. Soil element pools and nutrient availability increased with flow age independent of climate. The dry sites accumulated organic matter and nutrients more slowly than comparable wet sites, but relative nutrient availability to plants (as indicated by soil assays and foliar nutrients) was greater in the dry sites. Accumulation of soil organic matter and nutrients occurred most rapidly in lowerelevation sites on the young flows, but the largest accumulations occurred at higher elevations on old flows. The range of sites sampled represents a complete and largely independent matrix of major factors governing ecosystem structure and function. ?? 1992 Springer-Verlag.

  20. Drought alters interactions between root and foliar herbivores.

    PubMed

    Tariq, Muhammad; Rossiter, John T; Wright, Denis J; Staley, Joanna T

    2013-08-01

    Drought can alter plant quality and the strength of trophic interactions between herbivore groups, and is likely to increase in occurrence and severity under climate change. We hypothesized that changes in plant chemistry due to root herbivory and drought stress would affect the performance of a generalist and a specialist aphid species feeding on a Brassica plant. High drought stress increased the negative effect of root herbivory on the performance of both aphid species (30% decrease in fecundity and 15% reduction in intrinsic rate of increase). Aphid performance was greatest at moderate drought stress, though the two species differed in which treatment combination maximized performance. Nitrogen concentration was greatest in high and moderately drought-stressed plants without root herbivores and moderately drought-stressed plants under low root herbivore density, and correlated positively with aphid fecundity for both species. Glucosinolate concentrations increased 62% under combined drought stress and root herbivory, and were positively correlated with extended aphid development time. Root herbivory did not influence relative water content and foliar biomass under normal water regimes but they decreased 24 and 63%, respectively, under high drought stress. This study shows that drought can alter the strength of interactions between foliar and root herbivores, and that plant chemistry is key in mediating such interactions. The two aphid species responded in a broadly similar way to root herbivore and drought-stress treatments, which suggests that generalized predictions of the effects of abiotic factors on interactions between above- and below-ground species may be possible. PMID:23292454

  1. Foliar temperature acclimation reduces simulated carbon sensitivity to climate

    NASA Astrophysics Data System (ADS)

    Smith, Nicholas G.; Malyshev, Sergey L.; Shevliakova, Elena; Kattge, Jens; Dukes, Jeffrey S.

    2016-04-01

    Plant photosynthesis and respiration are the largest carbon fluxes between the terrestrial biosphere and the atmosphere, and their parameterizations represent large sources of uncertainty in projections of land carbon uptake in Earth system models (ESMs). The incorporation of temperature acclimation of photosynthesis and foliar respiration, commonly observed processes, into ESMs has been proposed as a way to reduce this uncertainty. Here we show that, across 15 flux tower sites spanning multiple biomes at various locations worldwide (10° S-67° N), acclimation parameterizations improve a model's ability to reproduce observed net ecosystem exchange of CO2. This improvement is most notable in tropical biomes, where photosynthetic acclimation increased model performance by 36%. The consequences of acclimation for simulated terrestrial carbon uptake depend on the process, region and time period evaluated. Globally, including acclimation has a net effect of increasing carbon assimilation and storage, an effect that diminishes with time, but persists well into the future. Our results suggest that land models omitting foliar temperature acclimation are likely to overestimate the temperature sensitivity of terrestrial carbon exchange, thus biasing projections of future carbon storage and estimates of policy indicators such as the transient climate response to cumulative carbon emissions.

  2. Mapping Amazonian Canopy Foliar Traits with Imaging Spectroscopy

    NASA Astrophysics Data System (ADS)

    Asner, G. P.; Martin, R.; Anderson, C. B.; Knapp, D. E.

    2014-12-01

    Spatial and temporal information on plant functional traits is lacking in ecology, which limits our understanding of how plant communities and ecosystems are changing. This problem is acute in remote tropical regions such as in Andean and Amazonian forests, where information on plant functional traits is difficult to ascertain. We used Carnegie Airborne Observatory visible-to-shortwave infrared (VSWIR) imaging spectroscopy with light detection and ranging (LiDAR) to assess the chemical composition of tropical forests along a 3000 m elevation gradient from lowland Amazonia to the Andean treeline. We calibrated and validated the retrieval of 15 canopy foliar chemicals and leaf mass per area (LMA) in 81 one-hectare field plots using a new VSWIR-LiDAR fusion approach. Remotely sensed estimates of elevational changes in forest foliar pigments, nitrogen, phosphorus, water, soluble and total carbon, cellulose and LMA were similar to those derived via laborious field survey and laboratory analysis. This new airborne approach addresses the inherent limitations and sampling biases associated with field-based studies of forest functional traits, particularly in structurally and floristically complex tropical canopies.

  3. Enhanced Disease Susceptibility1 Mediates Pathogen Resistance and Virulence Function of a Bacterial Effector in Soybean1[C][W][OPEN

    PubMed Central

    Wang, Jialin; Shine, M.B.; Gao, Qing-Ming; Navarre, Duroy; Jiang, Wei; Liu, Chunyan; Chen, Qingshan; Hu, Guohua; Kachroo, Aardra

    2014-01-01

    Enhanced disease susceptibility1 (EDS1) and phytoalexin deficient4 (PAD4) are well-known regulators of both basal and resistance (R) protein-mediated plant defense. We identified two EDS1-like (GmEDS1a/GmEDS1b) proteins and one PAD4-like (GmPAD4) protein that are required for resistance signaling in soybean (Glycine max). Consistent with their significant structural conservation to Arabidopsis (Arabidopsis thaliana) counterparts, constitutive expression of GmEDS1 or GmPAD4 complemented the pathogen resistance defects of Arabidopsis eds1 and pad4 mutants, respectively. Interestingly, however, the GmEDS1 and GmPAD4 did not complement pathogen-inducible salicylic acid accumulation in the eds1/pad4 mutants. Furthermore, the GmEDS1a/GmEDS1b proteins were unable to complement the turnip crinkle virus coat protein-mediated activation of the Arabidopsis R protein Hypersensitive reaction to Turnip crinkle virus (HRT), even though both interacted with HRT. Silencing GmEDS1a/GmEDS1b or GmPAD4 reduced basal and pathogen-inducible salicylic acid accumulation and enhanced soybean susceptibility to virulent pathogens. The GmEDS1a/GmEDS1b and GmPAD4 genes were also required for Resistance to Pseudomonas syringae pv glycinea2 (Rpg2)-mediated resistance to Pseudomonas syringae. Notably, the GmEDS1a/GmEDS1b proteins interacted with the cognate bacterial effector AvrA1 and were required for its virulence function in rpg2 plants. Together, these results show that despite significant structural similarities, conserved defense signaling components from diverse plants can differ in their functionalities. In addition, we demonstrate a role for GmEDS1 in regulating the virulence function of a bacterial effector. PMID:24872380

  4. Characterization of Bacterial and Fungal Microbiome in Children with Hirschsprung Disease with and without a History of Enterocolitis: A Multicenter Study

    PubMed Central

    Frykman, Philip K.; Nordenskjöld, Agneta; Kawaguchi, Akemi; Hui, Thomas T.; Granström, Anna L.; Cheng, Zhi; Tang, Jie; Underhill, David M.; Iliev, Iliyan; Funari, Vince A.; Wester, Tomas

    2015-01-01

    Development of potentially life-threatening enterocolitis is the most frequent complication in children with Hirschsprung disease (HSCR), even after definitive corrective surgery. Intestinal microbiota likely contribute to the etiology of enterocolitis, so the aim of this study was to compare the fecal bacterial and fungal communities of children who developed Hirschsprung-associated enterocolitis (HAEC) with HSCR patients who had never had enterocolitis. Eighteen Hirschsprung patients who had completed definitive surgery were enrolled: 9 had a history of HAEC and 9 did not. Fecal DNA was isolated and 16S and ITS-1 regions sequenced using Next Generation Sequencing and data analysis for species identification. The HAEC group bacterial composition showed a modest reduction in Firmicutes and Verrucomicrobia with increased Bacteroidetes and Proteobacteria compared with the HSCR group. In contrast, the fecal fungi composition of the HAEC group showed marked reduction in diversity with increased Candida sp., and reduced Malassezia and Saccharomyces sp. compared with the HSCR group. The most striking finding within the HAEC group is that the Candida genus segregated into “high burden” patients with 97.8% C. albicans and 2.2% C. tropicalis compared with “low burden” patients 26.8% C. albicans and 73% C. tropicalis. Interestingly even the low burden HAEC group had altered Candida community structure with just two species compared to more diverse Candida populations in the HSCR patients. This is the first study to identify Candida sp. as potentially playing a role in HAEC either as expanded commensal species as a consequence of enterocolitis (or treatment), or possibly as pathobioants contributing to the pathogenesis of HAEC. These findings suggest a dysbiosis in the gut microbial ecosystem of HAEC patients, such that there may be dominance of fungi and bacteria predisposing patients to development of HAEC. PMID:25909773

  5. Choline, Its Potential Role in Nonalcoholic Fatty Liver Disease, and the Case for Human and Bacterial Genes.

    PubMed

    Sherriff, Jill L; O'Sullivan, Therese A; Properzi, Catherine; Oddo, Josephine-Lee; Adams, Leon A

    2016-01-01

    Our understanding of the impact of poor hepatic choline/phosphatidylcholine availability in promoting the steatosis characteristic of human nonalcoholic fatty liver disease (NAFLD) has recently advanced and possibly relates to phosphatidylcholine/phosphatidylethanolamine concentrations in various, membranes as well as cholesterol dysregulation. A role for choline/phosphatidylcholine availability in the progression of NAFLD to liver injury and serious hepatic consequences in some individuals requires further elucidation. There are many reasons for poor choline/phosphatidylcholine availability in the liver, including low intake, estrogen status, and genetic polymorphisms affecting, in particular, the pathway for hepatic de novo phosphatidylcholine synthesis. In addition to free choline, phosphatidylcholine has been identified as a substrate for trimethylamine production by certain intestinal bacteria, thereby reducing host choline bioavailability and providing an additional link to the increased risk of cardiovascular disease faced by those with NAFLD. Thus human choline requirements are highly individualized and biomarkers of choline status derived from metabolomics studies are required to predict those at risk of NAFLD induced by choline deficiency and to provide a basis for human intervention trials. PMID:26773011

  6. A Genome-wide In Vitro Bacterial-Infection Screen Reveals Human Variation in the Host Response Associated with Inflammatory Disease

    PubMed Central

    Ko, Dennis C.; Shukla, Kajal P.; Fong, Christine; Wasnick, Michael; Brittnacher, Mitchell J.; Wurfel, Mark M.; Holden, Tarah D.; O'Keefe, Grant E.; Van Yserloo, Brian; Akey, Joshua M.; Miller, Samuel I.

    2009-01-01

    Recent progress in cataloguing common genetic variation has made possible genome-wide studies that are beginning to elucidate the causes and consequences of our genetic differences. Approaches that provide a mechanistic understanding of how genetic variants function to alter disease susceptibility and why they were substrates of natural selection would complement other approaches to human-genome analysis. Here we use a novel cell-based screen of bacterial infection to identify human variation in Salmonella-induced cell death. A loss-of-function allele of CARD8, a reported inhibitor of the proinflammatory protease caspase-1, was associated with increased cell death in vitro (p = 0.013). The validity of this association was demonstrated through overexpression of alternative alleles and RNA interference in cells of varying genotype. Comparison of mammalian CARD8 orthologs and examination of variation among different human populations suggest that the increase in infectious-disease burden associated with larger animal groups (i.e., herds and colonies), and possibly human population expansion, may have naturally selected for loss of CARD8. We also find that the loss-of-function CARD8 allele shows a modest association with an increased risk of systemic inflammatory response syndrome in a small study (p = 0.05). Therefore, a by-product of the selected benefit of loss of CARD8 could be increased inflammatory diseases. These results demonstrate the utility of genome-wide cell-based association screens with microbes in the identification of naturally selected variants that can impact human health. PMID:19664744

  7. Bacterial Keratitis

    MedlinePlus

    ... very quickly, and if left untreated, can cause blindness. The bacteria usually responsible for this type of ... to intense ultraviolet radiation exposure, e.g. snow blindness or welder's arc eye). Next Bacterial Keratitis Symptoms ...

  8. Etiologic and immunologic characteristics of thoroughbred horses with bacterial infectious upper respiratory disease at the Seoul Race Park.

    PubMed

    Ryu, Seung-Ho; Koo, Hye Cheong; Park, Young Kyung; Kim, Jun Man; Jung, Woo Kyung; Davis, William C; Park, Yong Ho; Lee, Chang-Woo

    2009-09-01

    Equine respiratory disease is a common cause of poor performance and training interruptions. The higher incidence rate of infectious upper respiratory disease (IURD) in thoroughbred racehorses at the Seoul Race Park coincided with the frequent stabling season, shorter stabling periods, and younger ages in this study. Incidence rates were also correlated with significantly lower proportions of cells expressing MHC class II-, CD2 antigen-, CD4+- or CD8+-T lymphocyte-, and B lymphocyte in IURD patients compared with healthy control groups in the summer and fall and in 2-and-3-year-old groups. The data suggested that movement and new environments may have resulted in immunosuppression and inappropriate responses to respiratory pathogens in IURD patients. The IURD incidence decreased with age, perhaps by the acquisition of immunity, and study results suggested that immunologic protection was associated with IURD, particularly in young thoroughbred racehorses. Streptococci isolates were identified in 11 of 72 IURD horses, and 3 of these isolates were identified as Streptococcus. equi subsp. equi. S. equi subsp. zooepidemicus was isolated from 2 of 23 IURD horses in the spring (8.7%), 5 of 23 in the summer (21.7%), and 1 of 6 in winter (16.7%). S. equi subsp. zooepidemicus (5%) was also identified in 3 of 61 isolates from clinically normal horses. Racetracks should implement anti-IURD protective measures by assessing the capacity of equine immunologic protection at the Park and by limiting the introduction of specific respiratory pathogens (such as S. equi subsp. equi) by preventing the access of infected horses with a respiratory pathogen-free certification system prior to Park entry. PMID:19809264

  9. Bacterial Enteric Infections Among Older Adults in the United States: Foodborne Diseases Active Surveillance Network, 1996–2012

    PubMed Central

    Scallan, Elaine; Crim, Stacy M.; Runkle, Arthur; Henao, Olga L.; Mahon, Barbara E.; Hoekstra, Robert M.; Griffin, Patricia M.

    2015-01-01

    Background A growing segment of the population—adults aged ≥65 years—is more susceptible than younger adults to certain enteric (including foodborne) infections and experience more severe disease. Materials and Methods Using data on laboratory-confirmed infections from the Foodborne Diseases Active Surveillance Network (FoodNet), we describe trends in the incidence of Campylobacter spp., Escherichia coli O157, Listeria monocytogenes, and nontyphoidal Salmonella infections in adults aged ≥65 years over time and by age group and sex. We used data from FoodNet and other sources to estimate the total number of illnesses, hospitalizations, and deaths in the United States caused by these infections each year using a statistical model to adjust for underdiagnosis (taking into account medical care-seeking, stool sample submission, laboratory practices, and test sensitivity). Results From 1996 to 2012, 4 pathogens caused 21,405 laboratory-confirmed infections among older adults residing in the FoodNet surveillance area; 49.3% were hospitalized, and 2.6% died. The average annual rate of infection was highest for Salmonella (12.8/100,000) and Campylobacter (12.1/100,000). Salmonella and Listeria led as causes of death. Among older adults, rates of laboratory-confirmed infection and the percentage of patients who were hospitalized and who died generally increased with age. A notable exception was the rate of Campylobacter infections, which decreased with increasing age. Adjusting for underdiagnosis, we estimated that these pathogens caused about 226,000 illnesses (~600/100,000) annually among U.S. adults aged ≥65 years, resulting in ~9700 hospitalizations and ~500 deaths. Conclusion Campylobacter, E. coli O157, Listeria, and Salmonella are major contributors to illness in older adults, highlighting the value of effective and targeted intervention. PMID:26067228

  10. Expansion of syndromic vaccine preventable disease surveillance to include bacterial meningitis and Japanese encephalitis: Evaluation of adapting polio and measles laboratory networks in Bangladesh, China and India, 2007–2008

    PubMed Central

    Cavallaro, Kathleen F.; Sandhu, Hardeep S.; Hyde, Terri B.; Johnson, Barbara W.; Fischer, Marc; Mayer, Leonard W.; Clark, Thomas A.; Pallansch, Mark A.; Yin, Zundong; Zuo, Shuyan; Hadler, Stephen C.; Diorditsa, Serguey; Hasan, A.S.M. Mainul; Bose, Anindya S.; Dietz, Vance

    2016-01-01

    Background Surveillance for acute flaccid paralysis with laboratory confirmation has been a key strategy in the global polio eradication initiative, and the laboratory platform established for polio testing has been expanded in many countries to include surveillance for cases of febrile rash illness to identify measles and rubella cases. Vaccine-preventable disease surveillance is essential to detect outbreaks, define disease burden, guide vaccination strategies and assess immunization impact. Vaccines now exist to prevent Japanese encephalitis (JE) and some etiologies of bacterial meningitis. Methods We evaluated the feasibility of expanding polio–measles surveillance and laboratory networks to detect bacterial meningitis and JE, using surveillance for acute meningitis-encephalitis syndrome in Bangladesh and China and acute encephalitis syndrome in India. We developed nine syndromic surveillance performance indicators based on international surveillance guidelines and calculated scores using supervisory visit reports, annual reports, and case-based surveillance data. Results Scores, variable by country and targeted disease, were highest for the presence of national guidelines, sustainability, training, availability of JE laboratory resources, and effectiveness of using polio–measles networks for JE surveillance. Scores for effectiveness of building on polio–measles networks for bacterial meningitis surveillance and specimen referral were the lowest, because of differences in specimens and techniques. Conclusions Polio–measles surveillance and laboratory networks provided useful infrastructure for establishing syndromic surveillance and building capacity for JE diagnosis, but were less applicable for bacterial meningitis. Laboratory-supported surveillance for vaccine-preventable bacterial diseases will require substantial technical and financial support to enhance local diagnostic capacity. PMID:25597940

  11. Genomes and Virulence Factors of Novel Bacterial Pathogens Causing Bleaching Disease in the Marine Red Alga Delisea pulchra

    PubMed Central

    Fernandes, Neil; Case, Rebecca J.; Longford, Sharon R.; Seyedsayamdost, Mohammad R.; Steinberg, Peter D.; Kjelleberg, Staffan; Thomas, Torsten

    2011-01-01

    Nautella sp. R11, a member of the marine Roseobacter clade, causes a bleaching disease in the temperate-marine red macroalga, Delisea pulchra. To begin to elucidate the molecular mechanisms underpinning the ability of Nautella sp. R11 to colonize, invade and induce bleaching of D. pulchra, we sequenced and analyzed its genome. The genome encodes several factors such as adhesion mechanisms, systems for the transport of algal metabolites, enzymes that confer resistance to oxidative stress, cytolysins, and global regulatory mechanisms that may allow for the switch of Nautella sp. R11 to a pathogenic lifestyle. Many virulence effectors common in phytopathogenic bacteria are also found in the R11 genome, such as the plant hormone indole acetic acid, cellulose fibrils, succinoglycan and nodulation protein L. Comparative genomics with non-pathogenic Roseobacter strains and a newly identified pathogen, Phaeobacter sp. LSS9, revealed a patchy distribution of putative virulence factors in all genomes, but also led to the identification of a quorum sensing (QS) dependent transcriptional regulator that was unique to pathogenic Roseobacter strains. This observation supports the model that a combination of virulence factors and QS-dependent regulatory mechanisms enables indigenous members of the host alga's epiphytic microbial community to switch to a pathogenic lifestyle, especially under environmental conditions when innate host defence mechanisms are compromised. PMID:22162749

  12. Relationship between photosynthetic phosphorus-use efficiency and foliar phosphorus fractions in tropical tree species

    PubMed Central

    Hidaka, Amane; Kitayama, Kanehiro

    2013-01-01

    How plants develop adaptive strategies to efficiently use nutrients on infertile soils is an important topic in plant ecology. It has been suggested that, with decreasing phosphorus (P) availability, plants increase photosynthetic P-use efficiency (PPUE) (i.e., the ratio of instantaneous photosynthetic carbon assimilation rate per unit foliar P). However, the mechanism to increase PPUE remains unclear. In this study, we tested whether high PPUE is explained by an optimized allocation of P in cells among P-containing biochemical compounds (i.e., foliar P fractions). We investigated the relationships among mass-based photosynthetic carbon assimilation rate (Amass), PPUE, total foliar P concentration, and foliar P fractions in 10 tree species in two tropical montane rain forests with differing soil P availability (five species on sedimentary soils and five species on P-poorer ultrabasic serpentine soils) on Mount Kinabalu, Borneo. We chemically fractionated foliar P into the following four fractions: metabolic P, lipid P, nucleic acid P, and residual P. Amass was positively correlated with the concentrations of total foliar P and of metabolic P across 10 tree species. Mean Amass and mean concentrations of total foliar P and of each foliar P fraction were lower on the P-poorer ultrabasic serpentine soils than on the sedimentary soils. There was a negative relationship between the proportion of metabolic P per total P and the proportion of lipid P per total P. PPUE was positively correlated with the ratio of metabolic P to lipid P. High PPUE is explained by the net effect of a relatively greater investment of P into P-containing metabolites and a relatively lesser investment into phospholipids in addition to generally reduced concentrations of all P fractions. We conclude that plants optimize the allocation of P among foliar P fractions for maintaining their productivity and growth and for reducing demand for P as their adaptation to P-poor soils. PMID:24455122

  13. Relationship between photosynthetic phosphorus-use efficiency and foliar phosphorus fractions in tropical tree species.

    PubMed

    Hidaka, Amane; Kitayama, Kanehiro

    2013-12-01

    How plants develop adaptive strategies to efficiently use nutrients on infertile soils is an important topic in plant ecology. It has been suggested that, with decreasing phosphorus (P) availability, plants increase photosynthetic P-use efficiency (PPUE) (i.e., the ratio of instantaneous photosynthetic carbon assimilation rate per unit foliar P). However, the mechanism to increase PPUE remains unclear. In this study, we tested whether high PPUE is explained by an optimized allocation of P in cells among P-containing biochemical compounds (i.e., foliar P fractions). We investigated the relationships among mass-based photosynthetic carbon assimilation rate (A mass), PPUE, total foliar P concentration, and foliar P fractions in 10 tree species in two tropical montane rain forests with differing soil P availability (five species on sedimentary soils and five species on P-poorer ultrabasic serpentine soils) on Mount Kinabalu, Borneo. We chemically fractionated foliar P into the following four fractions: metabolic P, lipid P, nucleic acid P, and residual P. A mass was positively correlated with the concentrations of total foliar P and of metabolic P across 10 tree species. Mean A mass and mean concentrations of total foliar P and of each foliar P fraction were lower on the P-poorer ultrabasic serpentine soils than on the sedimentary soils. There was a negative relationship between the proportion of metabolic P per total P and the proportion of lipid P per total P. PPUE was positively correlated with the ratio of metabolic P to lipid P. High PPUE is explained by the net effect of a relatively greater investment of P into P-containing metabolites and a relatively lesser investment into phospholipids in addition to generally reduced concentrations of all P fractions. We conclude that plants optimize the allocation of P among foliar P fractions for maintaining their productivity and growth and for reducing demand for P as their adaptation to P-poor soils. PMID:24455122

  14. Contribution of PsbS Function and Stomatal Conductance to Foliar Temperature in Higher Plants

    PubMed Central

    Kulasek, Milena; Bernacki, Maciej Jerzy; Ciszak, Kamil; Witoń, Damian; Karpiński, Stanisław

    2016-01-01

    Natural capacity has evolved in higher plants to absorb and harness excessive light energy. In basic models, the majority of absorbed photon energy is radiated back as fluorescence and heat. For years the proton sensor protein PsbS was considered to play a critical role in non-photochemical quenching (NPQ) of light absorbed by PSII antennae and in its dissipation as heat. However, the significance of PsbS in regulating heat emission from a whole leaf has never been verified before by direct measurement of foliar temperature under changing light intensity. To test its validity, we here investigated the foliar temperature changes on increasing and decreasing light intensity conditions (foliar temperature dynamics) using a high resolution thermal camera and a powerful adjustable light-emitting diode (LED) light source. First, we showed that light-dependent foliar temperature dynamics is correlated with Chl content in leaves of various plant species. Secondly, we compared the foliar temperature dynamics in Arabidopsis thaliana wild type, the PsbS null mutant npq4-1 and a PsbS-overexpressing transgenic line under different transpiration conditions with or without a photosynthesis inhibitor. We found no direct correlations between the NPQ level and the foliar temperature dynamics. Rather, differences in foliar temperature dynamics are primarily affected by stomatal aperture, and rapid foliar temperature increase during irradiation depends on the water status of the leaf. We conclude that PsbS is not directly involved in regulation of foliar temperature dynamics during excessive light energy episodes. PMID:27273581

  15. Bacterial tick-borne diseases caused by Bartonella spp., Borrelia burgdorferi sensu lato, Coxiella burnetii, and Rickettsia spp. among patients with cataract surgery

    PubMed Central

    Chmielewski, Tomasz; Brydak-Godowska, Joanna; Fiecek, Beata; Rorot, Urszula; Sędrowicz, Elżbieta; Werenowska, Małgorzata; Kopacz, Dorota; Hevelke, Agata; Michniewicz, Magdalena; Kęcik, Dariusz; Tylewska-Wierzbanowska, Stanisława

    2014-01-01

    Background Clinical data have shown that tick-borne diseases caused by Borrelia burgdorferi sensu lato, Bartonella spp., Coxiella burnetii, and Rickettsia spp. can affect the central nervous system, including the eye. The aim of this study was to establish a relationship between the incidence of cataract and evidence of bacterial infections transmitted by ticks. Material/Methods Fluid with lenticular masses from inside of the eye and blood from 109 patients were tested by PCR and sequencing. Sera from patients and the control group were subjected to serological tests to search specific antibodies to the bacteria. Results Microbiological analysis revealed the presence of Bartonella sp. DNA in intraoperative specimens from the eye in 1.8% of patients. Serological studies have shown that infections caused by B. burgdorferi sensu lato and Bartonella sp. were detected in 34.8% and 4.6% of patients with cataract surgery, respectively. Conclusions Presence of DNA of yet uncultured and undescribed species of Bartonella in eye liquid indicates past infection with this pathogen. Specific antibodies to B. burgdorferi sensu lato and Bartonella sp. are detected more frequently in patients with cataract compared to the control group. This could indicate a possible role of these organisms in the pathological processes within the eyeball, leading to changes in the lens. Further studies are needed to identify Bartonella species, as well as to recognize the infectious mechanisms involved in cataract development. PMID:24902636

  16. Expression and Functional Roles of the Pepper Pathogen-Induced bZIP Transcription Factor CabZIP2 in Enhanced Disease Resistance to Bacterial Pathogen Infection.

    PubMed

    Lim, Chae Woo; Baek, Woonhee; Lim, Sohee; Han, Sang-Wook; Lee, Sung Chul

    2015-07-01

    A pepper bZIP transcription factor gene, CabZIP2, was isolated from pepper leaves infected with a virulent strain of Xanthomonas campestris pv. vesicatoria. Transient expression analysis of the CabZIP2-GFP fusion protein in Nicotiana benthamiana revealed that the CabZIP2 protein is localized in the cytoplasm as well as the nucleus. The acidic domain in the N-terminal region of CabZIP2 that is fused to the GAL4 DNA-binding domain is required to activate the transcription of reporter genes in yeast. Transcription of CabZIP2 is induced in pepper plants inoculated with virulent or avirulent strains of X. campestris pv. vesicatoria. The CabZIP2 gene is also induced by defense-related hormones such as salicylic acid, methyl jasmonate, and ethylene. To elucidate the in vivo function of the CabZIP2 gene in plant defense, virus-induced gene silencing in pepper and overexpression in Arabidopsis were used. CabZIP2-silenced pepper plants were susceptible to infection by the virulent strain of X. campestris pv. vesicatoria, which was accompanied by reduced expression of defense-related genes such as CaBPR1 and CaAMP1. CabZIP2 overexpression in transgenic Arabidopsis plants conferred enhanced resistance to Pseudomonas syringae pv. tomato DC3000. Together, these results suggest that CabZIP2 is involved in bacterial disease resistance. PMID:25738319

  17. A Bacterial Component to Alzheimer's-Type Dementia Seen via a Systems Biology Approach that Links Iron Dysregulation and Inflammagen Shedding to Disease.

    PubMed

    Pretorius, Etheresia; Bester, Janette; Kell, Douglas B

    2016-06-18

    The progression of Alzheimer's disease (AD) is accompanied by a great many observable changes, both molecular and physiological. These include oxidative stress, neuroinflammation, and (more proximal to cognitive decline) the death of neuronal and other cells. A systems biology approach seeks to organize these observed variables into pathways that discriminate those that are highly involved (i.e., causative) from those that are more usefully recognized as bystander effects. We review the evidence that iron dysregulation is one of the central causative pathway elements here, as this can cause each of the above effects. In addition, we review the evidence that dormant, non-growing bacteria are a crucial feature of AD, that their growth in vivo is normally limited by a lack of free iron, and that it is this iron dysregulation that is an important factor in their resuscitation. Indeed, bacterial cells can be observed by ultrastructural microscopy in the blood of AD patients. A consequence of this is that the growing cells can shed highly inflammatory components such as lipopolysaccharides (LPS). These too are known to be able to induce (apoptotic and pyroptotic) neuronal cell death. There is also evidence that these systems interact with elements of vitamin D metabolism. This integrative systems approach has strong predictive power, indicating (as has indeed been shown) that both natural and pharmaceutical iron chelators might have useful protective roles in arresting cognitive decline, and that a further assessment of the role of microbes in AD development is more than highly warranted. PMID:27340854

  18. Pyrosequencing-based profiling of archaeal and bacterial 16S rRNA genes identifies a novel archaeon associated with black band disease in corals.

    PubMed

    Sato, Yui; Willis, Bette L; Bourne, David G

    2013-11-01

    Black band disease (BBD) is a microbial consortium that creates anoxic, sulfide-rich microenvironments and kills underlying coral tissues as it rapidly migrates across colonies. Although bacterial communities associated with BBD have been studied extensively, the presence and roles of archaea are unexplored. Using amplicon-pyrosequencing of 16S ribosomal RNA genes, we investigated the community structure of both archaea and bacteria within microbial lesions of BBD and the less-virulent precursor stage, 'cyanobacterial patches' (CP), affecting the coral Montipora hispida. We detected characteristic shifts in microbial communities during the development of BBD from CP, reflecting microenvironmental changes within lesions. Archaeal profiles in CP suggested a diverse assemblage affiliated with the Thaumarchaeota and Euryarchaeota, similar to communities described for oxic marine environments. In contrast, a novel ribotype, distantly affiliated to the Euryarchaeota, dominated up to 94% of archaeal sequences retrieved from BBD. The physiological characteristics of this dominant archaeal ribotype are unknown because of the novelty of its 16S ribosomal RNA gene sequences; however, their prominent associations with BBD lesions suggest the ability to thrive in the organic- and sulfide-rich anoxic microenvironment characteristic of BBD lesions. Discovery of this novel archaeal ribotype provides new insights into the microbial ecology and aetiology of BBD. PMID:24112537

  19. In vitro growth of the bacterial kidney disease organism Renibacterium salmoninarum on a nonserum, noncharcoal-based "homospecies-metabolite" medium.

    PubMed

    Teska, J D

    1994-07-01

    Laboratory and field trials were conducted to evaluate in vitro growth of Renibacterium salmoninarum in media without serum or charcoal. Growth of this bacterium, the cause of bacterial kidney disease (BKD) in salmonids, is accelerated by addition of a growth enhancing "metabolite" of unknown composition to KDM2 medium, the medium commonly used for isolation of R. salmoninarum. KDM2 medium supplemented with greater than 1% (v/v) metabolite enhanced growth even without addition of either serum or charcoal. Medium containing 5% metabolite (denoted Five-M) allowed optimal growth in laboratory studies and was further evaluated as a primary plating medium for recovery of the bacterium isolated from chinook salmon (Oncorhynchus tshawytscha) exhibiting clinical BKD. Recovery rates of R. salmoninarum using Five-M medium were 4% and 36% higher, respectively, than comparable rates using a serum-based medium for the two salmon populations evaluated. Five-M medium is an effective, inexpensive alternative to serum-based or charcoal-based media. PMID:7933282

  20. Genetic variation in bacterial kidney disease (BKD) susceptibility in Lake Michigan Chinook Salmon and its progenitor population from the Puget Sound

    USGS Publications Warehouse

    Purcell, Maureen K.; Hard, Jeffrey J.; Neely, Kathleen G.; Park, Linda K.; Winton, James R.; Elliott, Diane G.

    2014-01-01

    Mass mortality events in wild fish due to infectious diseases are troubling, especially given the potential for long-term, population-level consequences. Evolutionary theory predicts that populations with sufficient genetic variation will adapt in response to pathogen pressure. Chinook Salmon Oncorhynchus tshawytscha were introduced into Lake Michigan in the late 1960s from a Washington State hatchery population. In the late 1980s, collapse of the forage base and nutritional stress in Lake Michigan were thought to contribute to die-offs of Chinook Salmon due to bacterial kidney disease (BKD). Previously, we demonstrated that Lake Michigan Chinook Salmon from a Wisconsin hatchery have greater survival following BKD challenge relative to their progenitor population. Here, we evaluated whether the phenotypic divergence of these populations in BKD susceptibility was due to selection rather than genetic drift. Comparison of the overall magnitude of quantitative trait to neutral marker divergence between the populations suggested selection had occurred but a direct test of quantitative trait divergence was not significant, preventing the rejection of the null hypothesis of differentiation through genetic drift. Estimates of phenotypic variation (VP), additive genetic variation (VA) and narrow-sense heritability (h2) were consistently higher in the Wisconsin relative to the Washington population. If selection had acted on the Wisconsin population there was no evidence of a concomitant loss of genetic variation in BKD susceptibility. The Renibacterium salmoninarum exposures were conducted at both 14°C and 9°C; the warmer temperature accelerated time to death in both populations and there was no evidence of phenotypic plasticity or a genotype-by-environment (G × E) interaction. High h2 estimates for BKD susceptibility in the Wisconsin population, combined with a lack of phenotypic plasticity, predicts that future adaptive gains in BKD resistance are still possible and

  1. A CCCH-Type Zinc Finger Nucleic Acid-Binding Protein Quantitatively Confers Resistance against Rice Bacterial Blight Disease1[W][OA

    PubMed Central

    Deng, Hanqing; Liu, Hongbo; Li, Xianghua; Xiao, Jinghua; Wang, Shiping

    2012-01-01

    Bacterial blight is a devastating disease of rice (Oryza sativa) caused by Xanthomonas oryzae pv oryzae (Xoo). Zinc finger proteins harboring the motif with three conserved cysteine residues and one histidine residue (CCCH) belong to a large family. Although at least 67 CCCH-type zinc finger protein genes have been identified in the rice genome, their functions are poorly understood. Here, we report that one of the rice CCCH-type zinc finger proteins, C3H12, containing five typical CX8-CX5-CX3-H zinc finger motifs, is involved in the rice-Xoo interaction. Activation of C3H12 partially enhanced resistance to Xoo, accompanied by the accumulation of jasmonic acid (JA) and induced expression of JA signaling genes in rice. In contrast, knockout or suppression of C3H12 resulted in partially increased susceptibility to Xoo, accompanied by decreased levels of JA and expression of JA signaling genes in rice. C3H12 colocalized with a minor disease resistance quantitative trait locus to Xoo, and the enhanced resistance of randomly chosen plants in the quantitative trait locus mapping population correlated with an increased expression level of C3H12. The C3H12 protein localized in the nucleus and possessed nucleic acid-binding activity in vitro. These results suggest that C3H12, as a nucleic acid-binding protein, positively and quantitatively regulates rice resistance to Xoo and that its function is likely associated with the JA-dependent pathway. PMID:22158700

  2. Genetic variation in bacterial kidney disease (BKD) susceptibility in Lake Michigan Chinook Salmon and its progenitor population from the Puget Sound.

    PubMed

    Purcell, Maureen K; Hard, Jeffrey J; Neely, Kathleen G; Park, Linda K; Winton, James R; Elliott, Diane G

    2014-03-01

    Mass mortality events in wild fish due to infectious diseases are troubling, especially given the potential for long-term, population-level consequences. Evolutionary theory predicts that populations with sufficient genetic variation will adapt in response to pathogen pressure. Chinook Salmon Oncorhynchus tshawytscha were introduced into Lake Michigan in the late 1960s from a Washington State hatchery population. In the late 1980s, collapse of the forage base and nutritional stress in Lake Michigan were thought to contribute to die-offs of Chinook Salmon due to bacterial kidney disease (BKD). Previously, we demonstrated that Lake Michigan Chinook Salmon from a Wisconsin hatchery have greater survival following BKD challenge relative to their progenitor population. Here, we evaluated whether the phenotypic divergence of these populations in BKD susceptibility was due to selection rather than genetic drift. Comparison of the overall magnitude of quantitative trait to neutral marker divergence between the populations suggested selection had occurred but a direct test of quantitative trait divergence was not significant, preventing the rejection of the null hypothesis of differentiation through genetic drift. Estimates of phenotypic variation (VP ), additive genetic variation (VA ) and narrow-sense heritability (h (2)) were consistently higher in the Wisconsin relative to the Washington population. If selection had acted on the Wisconsin population there was no evidence of a concomitant loss of genetic variation in BKD susceptibility. The Renibacterium salmoninarum exposures were conducted at both 14°C and 9°C; the warmer temperature accelerated time to death in both populations and there was no evidence of phenotypic plasticity or a genotype-by-environment (G × E) interaction. High h (2) estimates for BKD susceptibility in the Wisconsin population, combined with a lack of phenotypic plasticity, predicts that future adaptive gains in BKD resistance are still

  3. Neglected Bacterial Zoonoses

    PubMed Central

    Chikeka, Ijeuru; Dumler, J. Stephen

    2015-01-01

    Bacterial zoonoses comprise a group of diseases in humans or animals acquired by direct contact with or by oral consumption of contaminated animal materials, or via arthropod vectors. Among neglected infections, bacterial zoonoses are among the most neglected given emerging data on incidence and prevalence as causes of acute febrile illness, even in areas where recognized neglected tropical diseases occur frequently. While many other bacterial infections could also be considered in this neglected category, five distinct infections stand out because they are globally distributed, are acute febrile diseases, have high rates of morbidity and case fatality, and are reported as commonly as malaria, typhoid or dengue virus infections in carefully designed studies in which a broad spectrum diagnoses are actively sought. Thus, this review will focus attention on leptospirosis, relapsing fever borreliosis, and rickettsioses, including scrub typhus, murine typhus and spotted fever group rickettsiosis. Of greatest interest is the lack of distinguishing clinical features among these infections when in humans, which confounds diagnosis where laboratory confirmation is lacking, and in regions where clinical diagnosis is often attributed to one of several perceived more common threats. As diseases such as malaria come under improved control, the real impact of these common and under-recognized infections will become evident, as will the requirement for the strategies and allocation of resources for their control. PMID:25964152

  4. Laboratory Diagnosis of Bacterial Gastroenteritis

    PubMed Central

    Humphries, Romney M.

    2015-01-01

    SUMMARY Bacterial gastroenteritis is a disease that is pervasive in both the developing and developed worlds. While for the most part bacterial gastroenteritis is self-limiting, identification of an etiological agent by bacterial stool culture is required for the management of patients with severe or prolonged diarrhea, symptoms consistent with invasive disease, or a history that may predict a complicated course of disease. Importantly, characterization of bacterial enteropathogens from stool cultures in clinical laboratories is one of the primary means by which public health officials identify and track outbreaks of bacterial gastroenteritis. This article provides guidance for clinical microbiology laboratories that perform stool cultures. The general characteristics, epidemiology, and clinical manifestations of key bacterial enteropathogens are summarized. Information regarding optimal specimen collection, transport, and processing and current diagnostic tests and testing algorithms is provided. This article is an update of Cumitech 12A (P. H. Gilligan, J. M. Janda, M. A. Karmali, and J. M. Miller, Cumitech 12A, Laboratory diagnosis of bacterial diarrhea, 1992). PMID:25567220

  5. Foliar treatments of 2,4-dichlorophenoxyacetic acid for control of common scab in potato have beneficial effects on powdery scab control.

    PubMed

    Thompson, Hannah Katherine; Tegg, Robert Stephen; Corkrey, Ross; Wilson, Calum Rae

    2014-01-01

    Prior studies have shown that applications of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) to the foliage of potato plants can reduce common scab. Here field and glasshouse trials suggest that 2,4-D foliar treatments may also reduce the biologically distinct tuber disease, powdery scab. Significant correlations between suppression of common and powdery scab from the field trials suggested an interaction between the two diseases or possible additional broad spectrum mechanisms of enhanced defence against pathogen invasion provided by 2,4-D treatment. PMID:25009832

  6. Evidence for foliar endophytic nitrogen fixation in a widely distributed subalpine conifer

    DOE PAGESBeta

    Moyes, Andrew B.; Kueppers, Lara M.; Pett-Ridge, Jennifer; Carper, Dana L.; Vandehey, Nick; O'Neil, James; Frank, A. Carolin

    2016-02-01

    Coniferous forest nitrogen (N) budgets indicate unknown sources of N. A consistent association between limber pine (Pinus flexilis) and potential N2-fixing acetic acid bacteria (AAB) indicates that native foliar endophytes may supply subalpine forests with N.

  7. Toxicity of seven foliar insecticides to four insect parasitoids attacking citrus and cotton pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory studies were carried out to compare the relative toxicity of seven foliar insecticides against four species of beneficial insects representing two families of HYmenoptera: Aphelinidae (Aphytis melinus Debach, Eretmocerus eremicus Rose & Zolnerowich, and Encarsia formosa Gahan) and MYmarid...

  8. Shrimp pond effluent dominates foliar nitrogen in disturbed mangroves as mapped using hyperspectral imagery.

    PubMed

    Fauzi, Anas; Skidmore, Andrew K; van Gils, Hein; Schlerf, Martin; Heitkönig, Ignas M A

    2013-11-15

    Conversion of mangroves to shrimp ponds creates fragmentation and eutrophication. Detection of the spatial variation of foliar nitrogen is essential for understanding the effect of eutrophication on mangroves. We aim (i) to estimate nitrogen variability across mangrove landscapes of the Mahakam delta using airborne hyperspectral remote sensing (HyMap) and (ii) to investigate links between the variation of foliar nitrogen mapped and local environmental variables. In this study, multivariate prediction models achieved a higher level of accuracy than narrow-band vegetation indices, making multivariate modeling the best choice for mapping. The variation of foliar nitrogen concentration in mangroves was significantly influenced by the local environment: (1) position of mangroves (seaward/landward), (2) distance to the shrimp ponds, and (3) predominant mangrove species. The findings suggest that anthropogenic disturbances, in this case shrimp ponds, influence nitrogen variation in mangroves. Mangroves closer to the shrimp ponds had higher foliar nitrogen concentrations. PMID:24103095

  9. Exploring the remote sensing of foliar biochemical concentrations with AVIRIS data

    NASA Technical Reports Server (NTRS)

    Smith, Geoffrey M.; Curran, Paul J.

    1992-01-01

    Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data shows promise for the estimation of foliar biochemical concentrations at the scale of the canopy. There are, however, several problems associated with the use of AVIRIS data in this way and these are detailed in recent Plant Biochemical Workshop Report. The research reported was concentrated upon three of these problems: field sampling of forest canopies, wet laboratory assay of foliar chemicals, and the visualization of AVIRIS data.

  10. Lyme Disease

    MedlinePlus

    Lyme disease is a bacterial infection you get from the bite of an infected tick. The first symptom ... Muscle and joint aches A stiff neck Fatigue Lyme disease can be hard to diagnose because you may ...

  11. Lyme disease

    MedlinePlus

    Lyme disease is a bacterial infection that is spread through the bite of one of several types of ... Lyme disease is caused by bacteria called Borrelia burgdorferi ( B burgdorferi ). Blacklegged ticks and other species of ticks ...

  12. Foliar Water Uptake of Tamarix ramosissima from an Atmosphere of High Humidity

    PubMed Central

    Li, Shuang; Xiao, Hong-lang; Zhao, Liang; Zhou, Mao-Xian; Wang, Fang

    2014-01-01

    Many species have been found to be capable of foliar water uptake, but little research has focused on this in desert plants. Tamarix ramosissima was investigated to determine whether its leaves can directly absorb water from high humidity atmosphere and, if they can, to understand the magnitude and importance of foliar water uptake. Various techniques were adopted to demonstrate foliar water uptake under submergence or high atmospheric humidity. The mean increase in leaf water content after submergence was 29.38% and 20.93% for mature and tender leaves, respectively. In the chamber experiment, obvious reverse sap flow occurred when relative humidity (RH) was persistently above 90%. Reverse flow was recorded first in twigs, then in branches and stems. For the stem, the percentage of negative sap flow rate accounting for the maximum value of sap flow reached 10.71%, and its amount accounted for 7.54% of diurnal sap flow. Small rainfall can not only compensate water loss of plant by foliar uptake, but also suppress transpiration. Foliar uptake can appear in the daytime under certain rainfall events. High atmospheric humidity is beneficial for enhancing the water status of plants. Foliar uptake should be an important strategy of water acquisition for desert plants. PMID:24982964

  13. Rotavirus Surveillance at a WHO-Coordinated Invasive Bacterial Disease Surveillance Site in Bangladesh: A Feasibility Study to Integrate Two Surveillance Systems

    PubMed Central

    Ahmed, ASM Nawshad Uddin; Arumugam, Rajesh; Marzan, Mahfuza; Saha, Shampa; Arifeen, Shams El; Baqui, Abdullah H.; Black, Robert E.; Kang, Gagandeep; Saha, Samir Kumar

    2016-01-01

    The World Health Organization (WHO) currently coordinates rotavirus diarrhea and invasive bacterial disease (IBD) surveillance at 178 sentinel sites in 60 countries. However, only 78 sites participate in both surveillance systems using a common sentinel site. Here, we explored the feasibility of extending a WHO-IBD surveillance platform to generate data on the burden of rotaviral diarrhea and its epidemiological characteristics to prepare the countries to measure the impact of rotaviral vaccine. A six-month (July to December, 2012) surveillance, managed by IBD team, collected stool samples and clinical data from under-five children with acute watery diarrhea at an IBD sentinel site. Samples were tested for rotavirus antigen by ELISA and genotyped by PCR at the regional reference laboratory (RRL). Specimens were collected from 79% (n = 297) of eligible cases (n = 375); 100% of which were tested for rotavirus by ELISA and 54% (159/297) of them were positive. At RRL, all the cases were confirmed by PCR and genotyped (99%; 158/159). The typing results revealed the predominance of G12 (40%; 64/159) genotype, followed by G1 (31%; 50/159) and G9 (19%; 31/159). All in all, this exploratory surveillance collected the desired demographic and epidemiological data and achieved almost all the benchmark indicators of WHO, starting from enrollment number to quality assurance through a number of case detection, collection, and testing of specimens and genotyping of strains at RRL. The success of this WHO-IBD site in achieving these benchmark indicators of WHO can be used by WHO as a proof-of-concept for considering integration of rotavirus surveillance with WHO-IBD platforms, specifically in countries with well performing IBD site and no ongoing rotavirus surveillance. PMID:27096958

  14. Bacterial Larvicide, Bacillus thuringiensis israelensis Strain AM 65-52 Water Dispersible Granule Formulation Impacts Both Dengue Vector, Aedes aegypti (L.) Population Density and Disease Transmission in Cambodia.

    PubMed

    Setha, To; Chantha, Ngan; Benjamin, Seleena; Socheat, Doung

    2016-09-01

    A multi-phased study was conducted in Cambodia from 2005-2011 to measure the impact of larviciding with the bacterial larvicide, Bacillus thuringiensis israelensis (Bti), a water dispersible granule (WG) formulation on the vector, Aedes aegypti (L.) and the epidemiology. In our studies, all in-use containers were treated at 8 g/1000 L, including smaller containers and animal feeders which were found to contribute 23% of Ae aegypti pupae. The treated waters were subjected to routine water exchange activities. Pupal production was suppressed by an average 91% for 8 weeks. Pupal numbers continued to remain significantly lower than the untreated commune (UTC) for 13 weeks post treatment in the peak dengue vector season (p<0.05). Suppression of pupal production was supported by very low adult numbers in the treated commune. An average 70% of the household harbored 0-5 Ae aegypti mosquitoes per home for 8 weeks post treatment, but in the same period of time >50% of the household in the UTC harbored ≥11 mosquitoes per home. The adult population continued to remain at significantly much lower numbers in the Bti treated commune than in the UTC for 10-12 weeks post treatment (p<0.05). In 2011, a pilot operational program was evaluated in Kandal Province, a temephos resistant site. It was concluded that 2 cycles of Bti treatment in the 6 months monsoon season with complete coverage of the target districts achieved an overall dengue case reduction of 48% in the 6 treated districts compared to the previous year, 2010. Five untreated districts in the same province had an overwhelming increase of 352% of dengue cases during the same period of time. The larvicide efficacy, treatment of all in-use containers at the start of the monsoon season, together with treatment coverage of entire districts interrupted disease transmission in the temephos resistant province. PMID:27627758

  15. Foliar nitrogen, phosphorus and potassium content in trees in environmentally toxic plastic industry area.

    PubMed

    Sett, Rupnarayan; Soni, Bhawna

    2013-04-01

    In plants, nitrogen deficiency causes stunted growth and chlorosis or yellowing of the leaves due to decreased levels of chlorophyll, while excess nitrogen uptake may cause dark green overly vigorous foliage which may have increased susceptibility to disease and insect attacks. Phosphorus is an important nutrient in crop production, since many soils in their native state do not have sufficient available phosphorus to maximize crop yield. Potassium deficiency may cause necrosis or interveinal chlorosis. Plastics are synthetic or semi-synthetic moldable organic solids that are organic polymers of high molecular mass, most commonly derived from petrochemicals; these polymers are based on chains of carbon atoms alone or with oxygen, sulfur, or nitrogen. Plastic is a non- biodegradable major toxic pollutant. It pollutes earth and leads to air pollution and water pollution. Merely there is any safe way to dispose the hazardous plastic wastes. The study was targeted to estimate foliar level of NPK content of three plant species, viz. Cassia tora (Herb), Ailanthus excelsa (Tree) and Dalbergia sissoo (Tree) from polluted areas associated to polythene-industries as well as control areas having least pollution, where all the parameters were found to be higher than the control experiments. PMID:25464692

  16. Foliar nitrogen, phosphorus and potassium content in trees in environmentally toxic plastic industry area.

    PubMed

    Sett, Rupnarayan; Soni, Bhawna

    2013-04-01

    In plants, nitrogen deficiency causes stunted growth and chlorosis or yellowing of the leaves due to decreased levels of chlorophyll, while excess nitrogen uptake may cause dark green overly vigorous foliage which may have increased susceptibility to disease and insect attacks. Phosphorus is an important nutrient in crop production, since many soils in their native state do not have sufficient available phosphorus to maximize crop yield. Potassium deficiency may cause necrosis or interveinal chlorosis. Plastics are synthetic or semi-synthetic moldable organic solids that are organic polymers of high molecular mass, most commonly derived from petrochemicals; these polymers are based on chains of carbon atoms alone or with oxygen, sulfur, or nitrogen. Plastic is a non- biodegradable major toxic pollutant. It pollutes earth and leads to air pollution and water pollution. Merely there is any safe way to dispose the hazardous plastic wastes. The study was targeted to estimate foliar level of NPK content of three plant species, viz. Cassia tora (Herb), Ailanthus excelsa (Tree) and Dalbergia sissoo (Tree) from polluted areas associated to polythene-industries as well as control areas having least pollution, where all the parameters were found to be higher than the control experiments. PMID:25508323

  17. The defensive role of foliar endophytic fungi for a South American tree

    PubMed Central

    González-Teuber, Marcia

    2016-01-01

    Fungal endophytes colonize living internal plant tissues without causing any visible symptoms of disease. Endophytic fungi associated with healthy leaves may play an important role in the protection of hosts against herbivores and pathogens. In this study, the diversity of foliar endophytic fungi (FEF) of the southern temperate tree Embothrium coccineum (Proteaceae), as well as their role in plant protection in nature was determined. Fungal endophytes were isolated from 40 asymptomatic leaves by the culture method for molecular identification of the 18S rRNA gene. A relationship between FEF frequency and plant protection was evaluated in juveniles of E. coccineum. Fungal endophyte frequency was estimated using real-time PCR analyses to determine endophyte DNA content per plant. A total of 178 fungal isolates were identified, with sequence data revealing 34 different operational taxonomic units (OTUs). A few common taxa dominated the fungal endophyte community, whereas most taxa qualified as rare. A significant positive correlation between plant protection (evaluated in terms of percentage of leaf damage) and FEF frequency was found. Furthermore, in vitro confrontation assays indicated that FEF were able to inhibit the growth of fungal pathogens. The data showed a relatively high diversity of fungal endophytes associated with leaves of E. coccineum, and suggest a positive relationship between fungal endophyte frequencies in leaves and host protection in nature. PMID:27339046

  18. Control of foliar pathogens of spring barley using a combination of resistance elicitors

    PubMed Central

    Walters, Dale R.; Havis, Neil D.; Paterson, Linda; Taylor, Jeanette; Walsh, David J.; Sablou, Cecile

    2014-01-01

    The ability of the resistance elicitors acibenzolar-S-methyl (ASM), β-aminobutyric acid (BABA), cis-jasmone (CJ), and a combination of the three products, to control infection of spring barley by Rhynchosporium commune was examined under glasshouse conditions. Significant control of R. commune was provided by ASM and CJ, but the largest reduction in infection was obtained with the combination of the three elicitors. This elicitor combination was found to up-regulate the expression of PR-1b, which is used as a molecular marker for systemic acquired resistance (SAR). However, the elicitor combination also down-regulated the expression of LOX2, a gene involved in the biosynthesis of jasmonic acid (JA). In field experiments over 3 consecutive years, the effects of the elicitor combination were influenced greatly by crop variety and by year. For example, the elicitor combination applied on its own provided significant control of powdery mildew (Blumeria graminis f.sp. hordei) and R. commune in 2009, whereas no control on either variety was observed in 2007. In contrast, treatments involving both the elicitor combination and fungicides provided disease control and yield increases which were equal to, and in some cases better than that provided by the best fungicide-only treatment. The prospects for the use of elicitor plus fungicide treatments to control foliar pathogens of spring barley in practice are discussed. PMID:24904629

  19. The defensive role of foliar endophytic fungi for a South American tree.

    PubMed

    González-Teuber, Marcia

    2016-01-01

    Fungal endophytes colonize living internal plant tissues without causing any visible symptoms of disease. Endophytic fungi associated with healthy leaves may play an important role in the protection of hosts against herbivores and pathogens. In this study, the diversity of foliar endophytic fungi (FEF) of the southern temperate tree Embothrium coccineum (Proteaceae), as well as their role in plant protection in nature was determined. Fungal endophytes were isolated from 40 asymptomatic leaves by the culture method for molecular identification of the 18S rRNA gene. A relationship between FEF frequency and plant protection was evaluated in juveniles of E. coccineum Fungal endophyte frequency was estimated using real-time PCR analyses to determine endophyte DNA content per plant. A total of 178 fungal isolates were identified, with sequence data revealing 34 different operational taxonomic units (OTUs). A few common taxa dominated the fungal endophyte community, whereas most taxa qualified as rare. A significant positive correlation between plant protection (evaluated in terms of percentage of leaf damage) and FEF frequency was found. Furthermore, in vitro confrontation assays indicated that FEF were able to inhibit the growth of fungal pathogens. The data showed a relatively high diversity of fungal endophytes associated with leaves of E. coccineum, and suggest a positive relationship between fungal endophyte frequencies in leaves and host protection in nature. PMID:27339046

  20. Bacterial Diseases of Minor Importance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several bacteria are reported to attack hop infrequently, including a Corynebacterium spp. and Xanthomonas campestris pv. cannabis. Reports of Pseudomonas cannabina as a pathogen of hop can be found in the popular press, although the limited information on this organism in the scientific literature...

  1. Foliar Uptake of Atmospheric Reactive Nitrogen Pollution Along an Urban-Rural Gradient in New York State

    NASA Astrophysics Data System (ADS)

    Vallano, D.; Sparks, J. P.

    2008-12-01

    Vegetation is an important sink for atmospheric reactive nitrogen (N) pollution in terrestrial ecosystems, and when soil N is limiting, foliar N uptake can be a source of plant-available N. A proxy for pollution derived N, and in particular foliar assimilated N, would be useful to quantify the impact of the foliar uptake pathway on plant metabolism. Nitrogen stable isotope ratios (15N/14N) are practical for this purpose because forms of plant-available N often have varying isotopic compositions. However, the mechanisms driving differences in foliar N isotopic composition (δ15N) are still unresolved. Current understanding of foliar δ 15N suggests these values primarily represent the integration of the soil water solution δ15N, direct foliar uptake of atmospheric reactive N, within-plant fractionations, and fractionation due to the fungus to root transfer in mycorrhizae. In this study, we investigated the influence of direct foliar uptake, soil solution δ 15N, and mycorrhizae on foliar δ15N in seedlings of two dominant Northeastern tree species, red maple (Acer rubrum) and red oak (Quercus rubra), along an N deposition gradient in New York State. Using a potted plant mesocosm system, we compared foliar δ15N values directly to soil solution δ15N values while controlling for mycorrhizal associations. Both species showed higher foliar δ15N when exposed to fractionation by mycorrhizal associations. Overall, A. rubrum showed higher foliar δ15N than Q. rubra across all sites. In both species, patterns of foliar δ15N values were coupled with soil solution δ15N values across the N deposition gradient. Additionally, increasing atmospheric N deposition was correlated with higher foliar δ15N values in Q. rubra, but not in A. rubrum. Using a mixing model, we estimated that Q. rubra seedlings incorporated up to 7% of their assimilated N via direct foliar uptake of atmospheric N pollution. However, foliar uptake was not detectable in A. rubrum seedlings. Results

  2. Modeling intraocular bacterial infections.

    PubMed

    Astley, Roger A; Coburn, Phillip S; Parkunan, Salai Madhumathi; Callegan, Michelle C

    2016-09-01

    Bacterial endophthalmitis is an infection and inflammation of the posterior segment of the eye which can result in significant loss of visual acuity. Even with prompt antibiotic, anti-inflammatory and surgical intervention, vision and even the eye itself may be lost. For the past century, experimental animal models have been used to examine various aspects of the pathogenesis and pathophysiology of bacterial endophthalmitis, to further the development of anti-inflammatory treatment strategies, and to evaluate the pharmacokinetics and efficacies of antibiotics. Experimental models allow independent control of many parameters of infection and facilitate systematic examination of infection outcomes. While no single animal model perfectly reproduces the human pathology of bacterial endophthalmitis, investigators have successfully used these models to understand the infectious process and the host response, and have provided new information regarding therapeutic options for the treatment of bacterial endophthalmitis. This review highlights experimental animal models of endophthalmitis and correlates this information with the clinical setting. The goal is to identify knowledge gaps that may be addressed in future experimental and clinical studies focused on improvements in the therapeutic preservation of vision during and after this disease. PMID:27154427

  3. Bacterial Vaginosis

    MedlinePlus

    ... Pelvic Inflammatory Disease (PID) STDs & Infertility STDs & Pregnancy Syphilis Trichomoniasis Other STDs See Also Pregnancy Reproductive Health ... Pelvic Inflammatory Disease (PID) STDs & Infertility STDs & Pregnancy Syphilis Trichomoniasis Other STDs See Also Pregnancy Reproductive Health ...

  4. Direct suppression of a rice bacterial blight (Xanthomonas oryzae pv. oryzae) by monoterpene (S)-limonene.

    PubMed

    Lee, Gun Woong; Chung, Moon-Soo; Kang, Mihyung; Chung, Byung Yeoup; Lee, Sungbeom

    2016-05-01

    Rice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a severe disease of rice plants. Upon pathogen infection, rice biosynthesizes phytoalexins, including diterpenoids such as momilactones, phytocassanes, and oryzalexins. However, information on headspace volatiles in response to Xoo infection is limited. We have examined headspace volatile terpenes, induced by the infection of Xoo, and investigated their biological roles in the rice plant. Monoterpenes α-thujene, α-pinene, sabinene, myrcene, α-terpene, and (S)-limonene and sesquiterpenes cyclosativene, α-copaene, and β-elemene were detected from 1-week-old Xoo-infected rice seedlings, by solid-phase microextraction-gas chromatography-mass spectrometry. All monoterpenes were constitutively released from rice seedlings before Xoo infection. However, (S)-limonene emission was further elicited after exposure of the seedlings to Xoo in coincidence with upregulation of limonene synthase gene (OsTPS20) transcripts. Only the stereospecific (S)-limonene [and not (R)-limonene or other monoterpenes] severely inhibited Xoo growth, as confirmed by disc diffusion and liquid culture assays. Rice seedlings showed suppressed pathogenic symptoms suggestive of resistance to Xoo infection after foliar treatment with (S)-limonene. Collectively, our findings suggest that (S)-limonene is a volatile phytoanticipin, which plays a significant role in suppressing Xoo growth in rice seedlings. PMID:26530963

  5. Increased Production of Lysozyme Associated with Bacterial Proliferation in Barrett's Esophagitis, Chronic Gastritis, Gluten-induced Atrophic Duodenitis (Celiac Disease), Lymphocytic Colitis, Collagenous Colitis, Ulcerative Colitis and Crohn's Colitis.

    PubMed

    Rubio, Carlos A

    2015-12-01

    The mucosa of the esophagus, the stomach, the small intestine, the large intestine and rectum are unremittingly challenged by adverse micro-environmental factors, such as ingested pathogenic and non-pathogenic bacteria, and harsh secretions with digestive properties with disparate pH, as well as bacteria and secretions from upstream GI organs. Despite the apparently inauspicious mixture of secretions and bacteria, the normal GI mucosa retains a healthy state of cell renewal. To by-pass the tough microenvironment, the epithelia of the GI react by speeding-up cell exfoliation, by increasing peristalsis, eliminating bacteria through secretion of plasma cell-immunoglobulins and by increasing production of natural antibacterial enzymes (lysozyme) and host defense peptides (defensin-5). Lysozyme was recently found up-regulated in Barrett's esophagitis, in chronic gastritis, in gluten-induced atrophic duodenitis (celiac disease), in collagenous colitis, in lymphocytic colitis and in Crohn's colitis. This up-regulation is a response directed towards the special types of bacteria thriving in the microenvironment in each of the aforementioned clinical inflammatory maladies. The purpose of that up-regulation is to protect the mucosa affected by the ongoing chronic inflammation. Bacterial antibiotic resistance continues to exhaust our supply of effective antibiotics. The future challenge is how to solve the increasing menace of bacterial resistance to anti-bacterial drugs. Further research on natural anti-bacterial enzymes such as lysozyme, appears mandatory. PMID:26637845

  6. Stoichiometric patterns in foliar nutrient resorption across multiple scales

    USGS Publications Warehouse

    Reed, Sasha C.; Townsend, Alan R.; Davidson, Eric A.; Cleveland, Cory C.

    2012-01-01

    *Nutrient resorption is a fundamental process through which plants withdraw nutrients from leaves before abscission. Nutrient resorption patterns have the potential to reflect gradients in plant nutrient limitation and to affect a suite of terrestrial ecosystem functions. *Here, we used a stoichiometric approach to assess patterns in foliar resorption at a variety of scales, specifically exploring how N : P resorption ratios relate to presumed variation in N and/or P limitation and possible relationships between N : P resorption ratios and soil nutrient availability. *N : P resorption ratios varied significantly at the global scale, increasing with latitude and decreasing with mean annual temperature and precipitation. In general, tropical sites (absolute latitudes < 23°26′) had N : P resorption ratios of < 1, and plants growing on highly weathered tropical soils maintained the lowest N : P resorption ratios. Resorption ratios also varied with forest age along an Amazonian forest regeneration chronosequence and among species in a diverse Costa Rican rain forest. *These results suggest that variations in N : P resorption stoichiometry offer insight into nutrient cycling and limitation at a variety of spatial scales, complementing other metrics of plant nutrient biogeochemistry. The extent to which the stoichiometric flexibility of resorption will help regulate terrestrial responses to global change merits further investigation.

  7. Acute Bacterial Cholangitis

    PubMed Central

    Zimmer, Vincent; Lammert, Frank

    2015-01-01

    Background Acute bacterial cholangitis for the most part owing to common bile duct stones is common in gastroenterology practice and represents a potentially life-threatening condition often characterized by fever, abdominal pain, and jaundice (Charcot's triad) as well as confusion and septic shock (Reynolds' pentad). Methods This review is based on a systematic literature review in PubMed with the search items ‘cholangitis’, ‘choledocholithiasis’, ‘gallstone disease’, ‘biliary infection’, and ‘biliary sepsis’. Results Although most patients respond to empiric broad-spectrum antibiotic treatment, timely endoscopic biliary drainage depending on the severity of the disease is required to eliminate the underlying obstruction. Specific recommendations have been derived from the Tokyo guideline working group consensus 2006 and its update in 2013, albeit poorly evidence-based, providing a comprehensive overview of diagnosis, classification, risk stratification, and treatment algorithms in acute bacterial cholangitis. Conclusion Prompt clinical recognition and accurate diagnostic workup including adequate laboratory assessment and (aetiology-oriented) imaging are critical steps in the management of cholangitis. Treatment is directed at the two major interrelated pathophysiologic components, i.e. bacterial infection (immediate antimicrobial therapy) and bile duct obstruction (biliary drainage). As for the latter, transpapillary endoscopic drainage by stent or nasobiliary drain and/or same-session bile duct clearance, depending on individual disease severity, represent first-line treatment approaches. PMID:26468310

  8. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing.

    PubMed

    Yang, Chuanyu; Powell, Charles A; Duan, Yongping; Shatters, Robert; Zhang, Muqing

    2015-01-01

    Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm) coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm) compared to those of Brij 35 (4.34 mm) and Amp solution (2.83 mm) alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O) nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB. PMID:26207823

  9. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing

    PubMed Central

    Yang, Chuanyu; Powell, Charles A.; Duan, Yongping; Shatters, Robert; Zhang, Muqing

    2015-01-01

    Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm) coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm) compared to those of Brij 35 (4.34 mm) and Amp solution (2.83 mm) alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O) nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB. PMID:26207823

  10. Impact of foliar herbivory on the development of a root-feeding insect and its parasitoid

    PubMed Central

    Bezemer, T. Martijn; Cortesero, Anne Marie; Van der Putten, Wim H.; Vet, Louise E. M.; Harvey, Jeffrey A.

    2007-01-01

    The majority of studies exploring interactions between above- and below-ground biota have been focused on the effects of root-associated organisms on foliar herbivorous insects. This study examined the effects of foliar herbivory by Pieris brassicae L. (Lepidoptera: Pieridae) on the performance of the root herbivore Delia radicum L. (Diptera: Anthomyiidae) and its parasitoid Trybliographa rapae (Westwood) (Hymenoptera: Figitidae), mediated through a shared host plant Brassica nigra L. (Brassicaceae). In the presence of foliar herbivory, the survival of D. radicum and T. rapae decreased significantly by more than 50%. In addition, newly emerged adults of both root herbivores and parasitoids were significantly smaller on plants that had been exposed to foliar herbivory than on control plants. To determine what factor(s) may have accounted for the observed results, we examined the effects of foliar herbivory on root quantity and quality. No significant differences in root biomass were found between plants with and without shoot herbivore damage. Moreover, concentrations of nitrogen in root tissues were also unaffected by shoot damage by P. brassicae larvae. However, higher levels of indole glucosinolates were measured in roots of plants exposed to foliar herbivory, suggesting that the development of the root herbivore and its parasitoid may be, at least partly, negatively affected by increased levels of these allelochemicals in root tissues. Our results show that foliar herbivores can affect the development not only of root-feeding insects but also their natural enemies. We argue that such indirect interactions between above- and below-ground biota may play an important role in the structuring and functioning of communities. PMID:17334787

  11. Capture of heavy metals and sulfur by foliar dust in urban Huizhou, Guangdong Province, China.

    PubMed

    Qiu, Yuan; Guan, Dongsheng; Song, Weiwei; Huang, Kangyou

    2009-04-01

    Foliar dust on urban tree leaf surfaces in Huizhou (HZ) in Guangdong Province of China was studied for a range of elements. The concentrations of the heavy metals (Cd, Cr, Cu, Pb, Zn) and sulfur in the foliar dust were determined by ICP-AES. Remote sensing imaging was used to estimate the total aboveground urban vegetation biomass in Huizhou, information that was then used to estimate the total removal of air particulates in the city by foliar dust. The results showed that the heavy metal concentrations in foliar dust were high, particularly for Cd and Pb. Concentrations of Cd ranged from 6.2 to 12.8 mg kg(-1), while concentrations of Pb ranged from 434.0 to 512.0 mg kg(-1). The amount of foliar dust retained by the four tree species increased with time for 20 d following a rain event. The amount of foliar dust collected from different locations in the city was significantly different. Specifically, the heavy metal and sulfur pollution index in the different locations decreased in this order: Power Station (PS)>Electronic Industry Area (EIA)>Commercial and Traffic Area (CTA)>Residential Areas (RA)>Control Area (CA). These data suggest that the foliar dust can remove appreciable amounts of Cd, Cr, Cu, Pb, Zn, and S--0.040 t, 1.63 t, 2.70 t, 1.84 t, 5.54 t, and 19.52 t, respectively--from the atmosphere in the study area. This information can provide health-related impetus and guidance for the work of urban planners and those involved in environment protection. PMID:19201444

  12. Timing of foliar Zn application plays a vital role in minimizing Cd accumulation in wheat.

    PubMed

    Saifullah; Javed, Hina; Naeem, Asif; Rengel, Zed; Dahlawi, Saad

    2016-08-01

    Due to chemical and biochemical similarities between cadmium (Cd) and zinc (Zn), application of Zn may minimize Cd uptake by plants and ameliorate its toxicity. However, there is poor understanding of the comparative effectiveness of the foliar Zn application at different growth stages on Cd toxicity and accumulation in wheat. The present study was carried out to compare the effectiveness of foliarly applied Zn at different stages of plant growth to minimize Cd accumulation in wheat grains. Wheat (cv AARI-2011) was grown at three levels of soil Cd (0, 2.5, and 5.0 mg kg(-1)). Foliar application of Zn was carried out at either tillering, jointing, booting, heading, or grain filling stage using 0.05 % w/v aqueous solution of ZnSO4 · 7H2O. Increasing soil Cd had a negative effect on growth and yield attributes, including tiller production, root length and dry weight, plant height, 100-grain weight and grain and straw yield. Zinc foliar spray increased grain yield by increasing tiller production; importantly, an application at booting was more effective than at other stages. Foliarly applied Zn decreased Cd concentration in the roots, straw, and grain. Similar to grain yield, the largest decrease (74 %) in Cd concentration was associated with Zn foliar spray at booting. Grain yield was negatively related to grain Cd concentration which in turn showed a negative relationship with Zn concentration in leaves and grains. It is concluded that the booting stage is the suitable time for foliar application of Zn to (i) effectively minimize a Cd-induced loss in grain yield and (ii) decrease grain Cd concentration. PMID:27164881

  13. Diseases of Landscape Ornamentals. Slide Script.

    ERIC Educational Resources Information Center

    Powell, Charles C.; Sydnor, T. Davis

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with recognizing and controlling diseases found on ornamental landscape plants. Included in the script are narrations for use with a total of 80 slides illustrating various foliar diseases (anthracnose, black spot, hawthorn leaf blight,…

  14. Identifying Constraints to Potato System Sustainability: Diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four different potato cropping systems, designed to address specific management goals of soil conservation (SC), soil improvement (SI), disease suppression (DS), and a status quo (standard rotation) control (SQ), were evaluated for their effects on soilborne and foliar diseases of potato, as well as...

  15. Bacterial Genome Instability

    PubMed Central

    Darmon, Elise

    2014-01-01

    SUMMARY Bacterial genomes are remarkably stable from one generation to the next but are plastic on an evolutionary time scale, substantially shaped by horizontal gene transfer, genome rearrangement, and the activities of mobile DNA elements. This implies the existence of a delicate balance between the maintenance of genome stability and the tolerance of genome instability. In this review, we describe the specialized genetic elements and the endogenous processes that contribute to genome instability. We then discuss the consequences of genome instability at the physiological level, where cells have harnessed instability to mediate phase and antigenic variation, and at the evolutionary level, where horizontal gene transfer has played an important role. Indeed, this ability to share DNA sequences has played a major part in the evolution of life on Earth. The evolutionary plasticity of bacterial genomes, coupled with the vast numbers of bacteria on the planet, substantially limits our ability to control disease. PMID:24600039

  16. Detection and Validation of QTL Affecting Bacterial Cold Water Disease Resistance in Rainbow Trout Using Restriction-Site Associated DNA Sequencing

    PubMed Central

    Gao, Guangtu; Liu, Sixin; Hernandez, Alvaro G.; Rexroad, Caird E.

    2015-01-01

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. Using microsatellite markers in a genome scan, we previously detected significant and suggestive QTL affecting phenotypic variation in survival following challenge with Flavobacterium psychrophilum, the causative agent of BCWD in rainbow trout. In this study, we performed selective genotyping of SNPs from restriction-site associated DNA (RAD) sequence data from two pedigreed families (2009070 and 2009196) to validate the major QTL from the previous work and to detect new QTL. The use of RAD SNPs in the genome scans increased the number of mapped markers from ~300 to ~5,000 per family. The significant QTL detected in the microsatellites scan on chromosome Omy8 in family 2009070 was validated explaining up to 58% of the phenotypic variance in that family, and in addition, a second QTL was also detected on Omy8. Two novel QTL on Omy11 and 14 were also detected, and the previously suggestive QTL on Omy1, 7 and 25 were also validated in family 2009070. In family 2009196, the microsatellite significant QTL on Omy6 and 12 were validated and a new QTL on Omy8 was detected, but none of the previously detected suggestive QTL were validated. The two Omy8 QTL from family 2009070 and the Omy12 QTL from family 2009196 were found to be co-localized with handling and confinement stress response QTL that our group has previously identified in a separate pedigreed family. With the currently available data we cannot determine if the co-localized QTL are the result of genes with pleiotropic effects or a mere physical proximity on the same chromosome segment. The genetic markers linked to BCWD resistance QTL were used to query the scaffolds of the rainbow trout reference genome assembly and the QTL-positive scaffold sequences were found to include 100 positional candidate genes. Several of the candidate genes located on or near the two Omy8 QTL detected in family 2009070 suggest potential

  17. Evaluation of Genome-Enabled Selection for Bacterial Cold Water Disease Resistance Using Progeny Performance Data in Rainbow Trout: Insights on Genotyping Methods and Genomic Prediction Models

    PubMed Central

    Vallejo, Roger L.; Leeds, Timothy D.; Fragomeni, Breno O.; Gao, Guangtu; Hernandez, Alvaro G.; Misztal, Ignacy; Welch, Timothy J.; Wiens, Gregory D.; Palti, Yniv

    2016-01-01

    Bacterial cold water disease (BCWD) causes significant economic losses in salmonid aquaculture, and traditional family-based breeding programs aimed at improving BCWD resistance have been limited to exploiting only between-family variation. We used genomic selection (GS) models to predict genomic breeding values (GEBVs) for BCWD resistance in 10 families from the first generation of the NCCCWA BCWD resistance breeding line, compared the predictive ability (PA) of GEBVs to pedigree-based estimated breeding values (EBVs), and compared the impact of two SNP genotyping methods on the accuracy of GEBV predictions. The BCWD phenotypes survival days (DAYS) and survival status (STATUS) had been recorded in training fish (n = 583) subjected to experimental BCWD challenge. Training fish, and their full sibs without phenotypic data that were used as parents of the subsequent generation, were genotyped using two methods: restriction-site associated DNA (RAD) sequencing and the Rainbow Trout Axiom® 57 K SNP array (Chip). Animal-specific GEBVs were estimated using four GS models: BayesB, BayesC, single-step GBLUP (ssGBLUP), and weighted ssGBLUP (wssGBLUP). Family-specific EBVs were estimated using pedigree and phenotype data in the training fish only. The PA of EBVs and GEBVs was assessed by correlating mean progeny phenotype (MPP) with mid-parent EBV (family-specific) or GEBV (animal-specific). The best GEBV predictions were similar to EBV with PA values of 0.49 and 0.46 vs. 0.50 and 0.41 for DAYS and STATUS, respectively. Among the GEBV prediction methods, ssGBLUP consistently had the highest PA. The RAD genotyping platform had GEBVs with similar PA to those of GEBVs from the Chip platform. The PA of ssGBLUP and wssGBLUP methods was higher with the Chip, but for BayesB and BayesC methods it was higher with the RAD platform. The overall GEBV accuracy in this study was low to moderate, likely due to the small training sample used. This study explored the potential of GS for

  18. Frequency of Pathogenic Paediatric Bacterial Meningitis in Mozambique: The Critical Role of Multiplex Real-Time Polymerase Chain Reaction to Estimate the Burden of Disease

    PubMed Central

    Nhantumbo, Aquino Albino; Cantarelli, Vlademir Vicente; Caireão, Juliana; Munguambe, Alcides Moniz; Comé, Charlotte Elizabeth; Pinto, Gabriela do Carmo; Zimba, Tomás Francisco; Mandomando, Inácio; Semá, Cynthia Baltazar; Dias, Cícero; Moraes, Milton Ozório; Gudo, Eduardo Samo

    2015-01-01

    Background In Sub-Saharan Africa, including Mozambique, acute bacterial meningitis (ABM) represents a main cause of childhood mortality. The burden of ABM is seriously underestimated because of the poor performance of culture sampling, the primary method of ABM surveillance in the region. Low quality cerebrospinal fluid (CSF) samples and frequent consumption of antibiotics prior to sample collection lead to a high rate of false-negative results. To our knowledge, this study is the first to determine the frequency of ABM in Mozambique using real-time polymerase chain reaction (qPCR) and to compare results to those of culture sampling. Method Between March 2013 and March 2014, CSF samples were collected at 3 regional hospitals from patients under 5 years of age, who met World Health Organization case definition criteria for ABM. Macroscopic examination, cytochemical study, culture, and qPCR were performed on all samples. Results A total of 369 CSF samples were collected from children clinically suspected of ABM. qPCR showed a significantly higher detection rate of ABM-causing pathogens when compared to culture (52.3% [193/369] versus 7.3% [27/369], p = 0.000). The frequency of Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococci, and Neisseria meningitidis were 32.8% (121⁄369), 12.2%, (45⁄369), 3.0% (16⁄369) and 4.3% (11⁄369), respectively, significantly higher compared to that obtained on culture (p < 0.001 for each). Conclusion Our findings demonstrate that culture is less effective for the diagnosis of ABM than qPCR. The common use of culture rather than qPCR to identify ABM results in serious underestimation of the burden of the disease, and our findings strongly suggest that qPCR should be incorporated into surveillance activities for ABM. In addition, our data showed that S. pneumoniae represents the most common cause of ABM in children under 5 years of age. PMID:26393933

  19. The Influence of Time and Plant Species on the Composition of the Decomposing Bacterial Community in a Stream Ecosystem.

    PubMed

    Wymore, Adam S; Liu, Cindy M; Hungate, Bruce A; Schwartz, Egbert; Price, Lance B; Whitham, Thomas G; Marks, Jane C

    2016-05-01

    Foliar chemistry influences leaf decomposition, but little is known about how litter chemistry affects the assemblage of bacterial communities during decomposition. Here we examined relationships between initial litter chemistry and the composition of the bacterial community in a stream ecosystem. We incubated replicated genotypes of Populus fremontii and P. angustifolia leaf litter that differ in percent tannin and lignin, then followed changes in bacterial community composition during 28 days of decomposition using 16S rRNA gene-based pyrosequencing. Using a nested experimental design, the majority of variation in bacterial community composition was explained by time (i.e., harvest day) (R(2) = 0.50). Plant species, nested within harvest date, explained a significant but smaller proportion of the variation (R(2) = 0.03). Significant differences in community composition between leaf species were apparent at day 14, but no significant differences existed among genotypes. Foliar chemistry correlated significantly with community composition at day 14 (r = 0.46) indicating that leaf litter with more similar phytochemistry harbor bacterial communities that are alike. Bacteroidetes and β-proteobacteria dominated the bacterial assemblage on decomposing leaves, and Verrucomicrobia and α- and δ-proteobacteria became more abundant over time. After 14 days, bacterial diversity diverged significantly between leaf litter types with fast-decomposing P. fremontii hosting greater richness than slowly decomposing P. angustifolia; however, differences were no longer present after 28 days in the stream. Leaf litter tannin, lignin, and lignin: N ratios all correlated negatively with diversity. This work shows that the bacterial community on decomposing leaves in streams changes rapidly over time, influenced by leaf species via differences in genotype-level foliar chemistry. PMID:26879940

  20. Bacterial Games

    NASA Astrophysics Data System (ADS)

    Frey, Erwin; Reichenbach, Tobias

    Microbial laboratory communities have become model systems for studying the complex interplay between nonlinear dynamics of evolutionary selection forces, stochastic fluctuations arising from the probabilistic nature of interactions, and spatial organization. Major research goals are to identify and understand mechanisms that ensure viability of microbial colonies by allowing for species diversity, cooperative behavior and other kinds of "social" behavior. A synthesis of evolutionary game theory, nonlinear dynamics, and the theory of stochastic processes provides the mathematical tools and conceptual framework for a deeper understanding of these ecological systems. We give an introduction to the modern formulation of these theories and illustrate their effectiveness, focusing on selected examples of microbial systems. Intrinsic fluctuations, stemming from the discreteness of individuals, are ubiquitous, and can have important impact on the stability of ecosystems. In the absence of speciation, extinction of species is unavoidable, may, however, take very long times. We provide a general concept for defining survival and extinction on ecological time scales. Spatial degrees of freedom come with a certain mobility of individuals. When the latter is sufficiently high, bacterial community structures can be understood through mapping individual-based models, in a continuum approach, onto stochastic partial differential equations. These allow progress using methods of nonlinear dynamics such as bifurcation analysis and invariant manifolds. We conclude with a perspective on the current challenges in quantifying bacterial pattern formation, and how this might have an impact on fundamental research in nonequilibrium physics .

  1. The impact of foliar boron sprays on reproductive biology and seed quality of black gram.

    PubMed

    Pandey, Nalini; Gupta, Bhavana

    2013-01-01

    An experiment was conducted under glass house condition to study the effect of foliar application of boron (B) on reproductive biology and seed quality of black gram (Vigna mungo). Black gram (V. mungo L. var. DPU-88-31) was grown under controlled sand culture condition at deficient and sufficient B levels. After 32 days of sowing B deficient plants were sprayed with three concentrations of B (0.05%, 0.1% and 0.2% borax) at three different stages of reproductive development, i.e. prior to flowering, initiation of bud formation and after bud formation. Deficient B supply decreased the anther and pollen size, pollen tube growth, pollen viability as well as stigmatic receptivity which were increased by foliar B application. Foliar spray at all the three concentrations and at all stages increased the yield parameters like number of pods, pod size and number of seeds formed per plant. Foliar B application also improved the seed yield and seed quality in terms of storage seed proteins (albumin, globulin, glutenin and prolamin) and carbohydrates (sugars and starch) in black gram. The foliar application of B in appropriate doses (particularly 0.1%) after bud formation made quantitative and qualitative improvement in seed yield of black gram by supplementing additional/critical B requirements for reproductive development. PMID:22947393

  2. Host Genotype Shapes the Foliar Fungal Microbiome of Balsam Poplar (Populus balsamifera)

    PubMed Central

    Bálint, Miklós; Tiffin, Peter; Hallström, Björn; O’Hara, Robert B.; Olson, Matthew S.; Fankhauser, Johnathon D.; Piepenbring, Meike; Schmitt, Imke

    2013-01-01

    Foliar fungal communities of plants are diverse and ubiquitous. In grasses endophytes may increase host fitness; in trees, their ecological roles are poorly understood. We investigated whether the genotype of the host tree influences community structure of foliar fungi. We sampled leaves from genotyped balsam poplars from across the species' range, and applied 454 amplicon sequencing to characterize foliar fungal communities. At the time of the sampling the poplars had been growing in a common garden for two years. We found diverse fungal communities associated with the poplar leaves. Linear discriminant analysis and generalized linear models showed that host genotypes had a structuring effect on the composition of foliar fungal communities. The observed patterns may be explained by a filtering mechanism which allows the trees to selectively recruit fungal strains from the environment. Alternatively, host genotype-specific fungal communities may be present in the tree systemically, and persist in the host even after two clonal reproductions. Both scenarios are consistent with host tree adaptation to specific foliar fungal communities and suggest that there is a functional basis for the strong biotic interaction. PMID:23326555

  3. Changes on grape phenolic composition induced by grapevine foliar applications of phenylalanine and urea.

    PubMed

    Portu, J; López-Alfaro, I; Gómez-Alonso, S; López, R; Garde-Cerdán, T

    2015-08-01

    Grapevines may require the input of nitrogen to grow and to guarantee an appropriate grape composition. Recently there has been a growing interest in foliar fertilization, which entails a fast and efficient assimilation of the products. The aim of this work was to study the influence of foliar applications of phenylalanine and urea, at two different doses, on grape anthocyanins, flavonols, flavan-3-ols, phenolic acids, and stilbenes. All treatments were applied at veraison and one week later at doses of 0.9 and 1.5 kg N/ha. The results showed that the synthesis of phenolic compounds was favoured by foliar applications of phenylalanine and urea. The application of the lowest dose of urea was the most effective treatment, increasing the content of several anthocyanins and flavonols. Moreover, none of the foliar treatments worsened the grape phenolic composition. In conclusion, foliar application of phenylalanine and especially urea, could be an interesting management tool for improving grape quality and their health-promoting properties. PMID:25766815

  4. Precision and accuracy of visual foliar injury assessments

    SciTech Connect

    Gumpertz, M.L.; Tingey, D.T.; Hogsett, W.E.

    1982-07-01

    The study compared three measures of foliar injury: (i) mean percent leaf area injured of all leaves on the plant, (ii) mean percent leaf area injured of the three most injured leaves, and (iii) the proportion of injured leaves to total number of leaves. For the first measure, the variation caused by reader biases and day-to-day variations were compared with the innate plant-to-plant variation. Bean (Phaseolus vulgaris 'Pinto'), pea (Pisum sativum 'Little Marvel'), radish (Rhaphanus sativus 'Cherry Belle'), and spinach (Spinacia oleracea 'Northland') plants were exposed to either 3 ..mu..L L/sup -1/ SO/sub 2/ or 0.3 ..mu..L L/sup -1/ ozone for 2 h. Three leaf readers visually assessed the percent injury on every leaf of each plant while a fourth reader used a transparent grid to make an unbiased assessment for each plant. The mean leaf area injured of the three most injured leaves was highly correlated with all leaves on the plant only if the three most injured leaves were <100% injured. The proportion of leaves injured was not highly correlated with percent leaf area injured of all leaves on the plant for any species in this study. The largest source of variation in visual assessments was plant-to-plant variation, which ranged from 44 to 97% of the total variance, followed by variation among readers (0-32% of the variance). Except for radish exposed to ozone, the day-to-day variation accounted for <18% of the total. Reader bias in assessment of ozone injury was significant but could be adjusted for each reader by a simple linear regression (R/sup 2/ = 0.89-0.91) of the visual assessments against the grid assessments.

  5. Bacterial endophyte communities in the foliage of coast redwood and giant sequoia.

    PubMed

    Carrell, Alyssa A; Frank, Anna C

    2015-01-01

    The endophytic bacterial microbiome, with an emerging role in plant nutrient acquisition and stress tolerance, is much less studied in natural plant populations than in agricultural crops. In a previous study, we found consistent associations between trees in the pine family and acetic acid bacteria (AAB) occurring at high relative abundance inside their needles. Our objective here was to determine if that pattern may be general to conifers, or alternatively, is more likely restricted to pines or conifers growing in nutrient limited and exposed environments. We used 16S rRNA pyrosequencing to characterize the foliar endophyte communities of two conifers in the Cupressaceae family: Two coast redwood (CR; Sequoia sempervirens) populations and one giant sequoia (GS; Sequoiadendron giganteum) population were sampled. Similar to the pines, the endophyte communities of the giant trees were dominated by Proteobacteria, Firmicutes, Acidobacteria, and Actinobacteria. However, although some major operational taxonomic units (OTUs) occurred at a high relative abundance of 10-40% in multiple samples, no specific group of bacteria dominated the endophyte community to the extent previously observed in high-elevation pines. Several of the dominating bacterial groups in the CR and GS foliage (e.g., Bacillus, Burkholderia, Actinomycetes) are known for disease- and pest suppression, raising the possibility that the endophytic microbiome protects the giant trees against biotic stress. Many of the most common and abundant OTUs in our dataset were most similar to 16S rRNA sequences from bacteria found in lichens or arctic plants. For example, an OTU belonging to the uncultured Rhizobiales LAR1 lineage, which is commonly associated with lichens, was observed at high relative abundance in many of the CR samples. The taxa shared between the giant trees, arctic plants, and lichens may be part of a broadly defined endophyte microbiome common to temperate, boreal, and tundra ecosystems. PMID

  6. Bacterial endophyte communities in the foliage of coast redwood and giant sequoia

    PubMed Central

    Carrell, Alyssa A.; Frank, Anna C.

    2015-01-01

    The endophytic bacterial microbiome, with an emerging role in plant nutrient acquisition and stress tolerance, is much less studied in natural plant populations than in agricultural crops. In a previous study, we found consistent associations between trees in the pine family and acetic acid bacteria (AAB) occurring at high relative abundance inside their needles. Our objective here was to determine if that pattern may be general to conifers, or alternatively, is more likely restricted to pines or conifers growing in nutrient limited and exposed environments. We used 16S rRNA pyrosequencing to characterize the foliar endophyte communities of two conifers in the Cupressaceae family: Two coast redwood (CR; Sequoia sempervirens) populations and one giant sequoia (GS; Sequoiadendron giganteum) population were sampled. Similar to the pines, the endophyte communities of the giant trees were dominated by Proteobacteria, Firmicutes, Acidobacteria, and Actinobacteria. However, although some major operational taxonomic units (OTUs) occurred at a high relative abundance of 10–40% in multiple samples, no specific group of bacteria dominated the endophyte community to the extent previously observed in high-elevation pines. Several of the dominating bacterial groups in the CR and GS foliage (e.g., Bacillus, Burkholderia, Actinomycetes) are known for disease- and pest suppression, raising the possibility that the endophytic microbiome protects the giant trees against biotic stress. Many of the most common and abundant OTUs in our dataset were most similar to 16S rRNA sequences from bacteria found in lichens or arctic plants. For example, an OTU belonging to the uncultured Rhizobiales LAR1 lineage, which is commonly associated with lichens, was observed at high relative abundance in many of the CR samples. The taxa shared between the giant trees, arctic plants, and lichens may be part of a broadly defined endophyte microbiome common to temperate, boreal, and tundra ecosystems

  7. Small Intestinal Bacterial Overgrowth

    PubMed Central

    Dukowicz, Andrew C.; Levine, Gary M.

    2007-01-01

    Small intestinal bacterial overgrowth (SIBO), defined as excessive bacteria in the small intestine, remains a poorly understood disease. Initially thought to occur in only a small number of patients, it is now apparent that this disorder is more prevalent than previously thought. Patients with SIBO vary in presentation, from being only mildly symptomatic to suffering from chronic diarrhea, weight loss, and malabsorption. A number of diagnostic tests are currently available, although the optimal treatment regimen remains elusive. Recently there has been renewed interest in SIBO and its putative association with irritable bowel syndrome. In this comprehensive review, we will discuss the epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of SIBO. PMID:21960820

  8. Magnetic resonance imaging of sugar beet taproots in soil reveals growth reduction and morphological changes during foliar Cercospora beticola infestation.

    PubMed

    Schmittgen, Simone; Metzner, Ralf; Van Dusschoten, Dagmar; Jansen, Marcus; Fiorani, Fabio; Jahnke, Siegfried; Rascher, Uwe; Schurr, Ulrich

    2015-09-01

    Cercospora leaf spot (CLS) infection can cause severe yield loss in sugar beet. Introduction of Cercospora-resistant varieties in breeding programmes is important for plant protection to reduce both fungicide applications and the risk of the development of fungal resistance. However, in vivo monitoring of the sugar-containing taproots at early stages of foliar symptoms and the characterization of the temporal development of disease progression has proven difficult. Non-invasive magnetic resonance imaging (MRI) measurements were conducted to quantify taproot development of genotypes with high (HS) and low (LS) levels of susceptibility after foliar Cercospora inoculation. Fourteen days post-inoculation (dpi) the ratio of infected leaf area was still low (~7%) in both the HS and LS genotypes. However, during this period, the volumetric growth of the taproot had already started to decrease. Additionally, inoculated plants showed a reduction of the increase in width of inner cambial rings while the width of outer rings increased slightly compared with non-inoculated plants. This response partly compensated for the reduced development of inner rings that had a vascular connection with Cercospora-inoculated leaves. Hence, alterations in taproot anatomical features such as volume and cambial ring development can be non-invasively detected already at 14 dpi, providing information on the early impact of the infection on whole-plant performance. All these findings show that MRI is a suitable tool to identify promising candidate parent lines with improved resistance to Cercospora, for example with comparatively lower taproot growth reduction at early stages of canopy infection, for future introduction into breeing programmes. PMID:25873673

  9. Bacterial Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Lauga, Eric

    2016-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells, yet they represent the bulk of the world's biomass and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micrometer scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically complex environments. Using hydrodynamics as an organizing framework, I review the biomechanics of bacterial motility and look ahead to future challenges.

  10. New strategies for managing leaf diseases of alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf diseases are a serious problem for alfalfa management in all areas where alfalfa is grown. Defoliation from leaf diseases has been measured from 3-71% depending on time of year, environmental conditions, age of the stand, and location. In addition to yield loss, foliar diseases can reduce forag...

  11. Quantitative Trait Loci Associated with Foliar Trigonelline Accumulation in Glycine Max L

    PubMed Central

    2002-01-01

    The objective of this study was to utilize a Glycine max RIL population to (1) evaluate foliar trigonelline (TRG) content in field-grown soybean, (2) determine the heritability of TRG accumulation, and (3) identify DNA markers linked to quantitative trait loci (QTLs) conditioning variation in TRG accumulation. Frequency distributions of 70 recombinant inbred lines showed statistically no significant departure from normality (P > .05) for TRG accumulation measured at pod development stage (R4). Six different molecular linkage groups (LGs) (B2, C2, D2, G, J, and K) were identified to be linked to QTLs for foliar TRG accumulation. Two unique microsatellite markers (SSR) on two different linkage groups identified QTL significantly associated with foliar TRG accumulation: a region on LG J (Satt285) (P = .0019, R2 = 15.9%) and a second region on LG C2 (Satt079) (P = .0029, R2 = 13.4%). PMID:12488580

  12. Methyl jasmonate foliar application to Tempranillo vineyard improved grape and wine phenolic content.

    PubMed

    Portu, Javier; Santamaría, Pilar; López-Alfaro, Isabel; López, Rosa; Garde-Cerdán, Teresa

    2015-03-01

    The importance of phenolic compounds for grape and wine quality has drawn attention to studying different practices with the aim of increasing their content. Cluster application of elicitors is a viticultural practice that has shown promising results in recent years. However, cluster application requires a previous defoliation, which is time-consuming and expensive. In the present study, methyl jasmonate was foliar applied to Tempranillo grapevines in order to study its effect on grape and wine phenolic composition. Methyl jasmonate foliar application increased anthocyanin and stilbene content in both grape and wine, besides enhancing wine flavonol content. This treatment induced the synthesis of 3-O-glucosides of petunidin and peonidin and trans-p-coumaroyl derivatives of cyanidin and peonidin. For stilbenes, trans-piceid content was considerably increased in both grape and wine. The results obtained suggest that methyl jasmonate foliar application could be a simple and accessible practice to enhance grape and wine quality. PMID:25672964

  13. Purple phototrophic bacterium enhances stevioside yield by Stevia rebaudiana Bertoni via foliar spray and rhizosphere irrigation.

    PubMed

    Wu, Jing; Wang, Yiming; Lin, Xiangui

    2013-01-01

    This study was conducted to compare the effects of foliar spray and rhizosphere irrigation with purple phototrophic bacteria (PPB) on growth and stevioside (ST) yield of Stevia. rebaudiana. The S. rebaudiana plants were treated by foliar spray, rhizosphere irrigation, and spray plus irrigation with PPB for 10 days, respectively. All treatments enhanced growth of S. rebaudiana, and the foliar method was more efficient than irrigation. Spraying combined with irrigation increased the ST yield plant (-1) by 69.2% as compared to the control. The soil dehydrogenase activity, S. rebaudiana shoot biomass, chlorophyll content in new leaves, and soluble sugar in old leaves were affected significantly by S+I treatment, too. The PPB probably works in the rhizosphere by activating the metabolic activity of soil bacteria, and on leaves by excreting phytohormones or enhancing the activity of phyllosphere microorganisms. PMID:23825677

  14. Bacterial Infections

    MedlinePlus

    ... body will learn to resist them causing antibiotic resistance. Later, you could get or spread an infection that those antibiotics cannot cure. NIH: National Institute of Allergy and Infectious Diseases

  15. Bacterial Vaginosis

    MedlinePlus

    ... had sex. You cannot get BV from toilet seats, bedding, or swimming pools. How can I avoid ... chlamydia and gonorrhea. These bacteria can sometimes cause pelvic inflammatory disease (PID), which can make it difficult ...

  16. Sugarbeet Cultivar Evaluation for Bacterial Root Rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial root rot of sugarbeet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, studies were conducted to establish an assa...

  17. Eleven-year response of foliar chemistry to chronic nitrogen and sulfur additions at the Bear Brooks Watershed in Maine

    SciTech Connect

    Jose Alexander Elvir; Gregory J. White

    2005-06-01

    The foliar chemistry of sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Ehrh.), and red spruce (Picea rubens Sarg.) was studied from 1993 to 2003 at the Bear Brook Watershed in Maine (BBWM). The BBWM is a paired-watershed forest ecosystem study, with one watershed treated bimonthly since 1989 with ammonium sulfate ((NH4)2SO4) at a rate of 25.2 kg N·ha–1·year–1. Foliar N concentrations were higher in all tree species within the treated watershed compared with trees within the reference watershed. Foliar Ca and Mg concentrations were lower in American beech and red spruce within the treated watershed. There were no significant differences in foliar K concentrations between watersheds. Foliar P and Mn concentration differences between watersheds were inconsistent among years. Differences in foliar N concentrations between watersheds declined over time in sugar maple but not in red spruce or American beech. Differences in foliar Ca and Mg concentrations between the treated and reference watersheds increased over time for American beech and red spruce, primarily because of a consistent decline in concentrations of these nutrients in trees within the treated watershed. No temporal trends in foliar Ca and Mg concentration differences between watersheds were observed for sugar maple.

  18. Soybean seed phenol, lignin, and isoflavones and sugars composition are altered by Foliar Boron application in soybean under water stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research showed that foliar boron (B) fertilizer at flowering or seed-fill growth stages altered seed protein, oil, and fatty acids. The objective of this research was to investigate the effects of foliar B fertilizer on seed phenolics (phenol, lignin, and isoflavones) and sugars concentrat...

  19. Foliar Shielding: How Non-Meteoric Water Deposition Helps Leaves Survive Drought by Reducing Incoming Energy

    NASA Astrophysics Data System (ADS)

    Gerlein-Safdi, C.; Sinkler, C. J.; Caylor, K. K.

    2015-12-01

    The uptake of water from the surface of the leaves, called foliar uptake, is common when rainfall is scarce and non-meteoric water (dew or fog) is the only source of water. However, many species have very water repellent leaves. Past studies have not differentiated between the uptake of water and the impact of the droplets on the energy balance of the leaf, which we call 'foliar shielding'. Leaves of the hydrophobic Colocasia esculenta were misted with isotopically enriched water in order to mimic non-meteoric water deposition. The leaf water potential and water isotopes were monitored for different water-stress conditions. A new protocol was developed for the fast analysis of leaf water isotopes using the Picarro induction module coupled to a laser spectrometer. Comparing the isotopic composition of the bulk leaf water at the end of the experiment, the misted leaves exhibit a d-excess higher by c. 63‰ than the control ones (P < 0.001). Low d-excess values are commonly associated with a high transpiration rate. Linking isotopic enrichment with leaf transpiration rate, we find a c. 30% decrease in transpiration rate for the treated leaves compared to the control (P < 0.001). Water-stressed leaves that were misted regularly exhibit a c. 64% smaller decline in water potential than water-stressed leaves that did not get misted (P < 0.05). Three possible mechanisms are proposed for the interaction of water droplets with the leaf energy and water balance. Comparing three previous foliar uptake studies to our results, we conclude that foliar shielding has a comparable yet opposite effect to foliar uptake on leaf water isotopes and that it is necessary to consider both processes when estimating foliar uptake of fog water.

  20. Changes in Foliar Chemistry Along a Midwestern Air Pollution Gradient: 1988- 2005

    NASA Astrophysics Data System (ADS)

    Talhelm, A. F.; Burton, A. J.; Pregitzer, K. S.

    2008-12-01

    Sugar maple (Acer saccharum) leaf litter has been collected annually for the past two decades from four sites in Michigan along a regional gradient in air pollution. During this time, wet acid deposition at monitoring stations near these sites declined 20-30 % while wet deposition of nitrogen remained virtually unchanged. Given these dynamics, we examined the foliar chemistry of this leaf litter to determine (a) if concentrations of the biologically important elements Ca and Al had responded to the reduction in acid deposition and (b) if foliar N concentrations and δ15N values reflected a trend toward increased N availability resulting from the persistence of high rates of N deposition. During the study period of 1988-2005, the foliar [Ca] declined significantly at three of the four sites and the foliar [Al] declined significantly at all four sites. Together, these changes suggest that amount of these elements removed from exchange sites and put into soil solution has decreased with the decline in acid deposition. Furthermore, the ratio of Ca:Al significantly increased at each site. Changes in the Ca:Al are of particular importance because low Ca to Al ratios in foliar tissue have been strongly implicated in declines in plant growth resulting from acid deposition. The increase in the foliar Ca:Al suggests that rather than causing a lasting depletion of base cations, previous highs in acid deposition had a transient effect from which hardwood forests in this region have largely recovered. In contrast, there were no significant trends in the [N] at any of the four sites and only one site in the middle of the pollution gradient showed a significant trend in δ15N that implies increased N availability. These results suggest that current levels of N deposition are not causing widespread increases in the amount of N available to plants in these ecosystems and do not appear to be quickly pushing the systems toward N saturation.