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Sample records for foliar bacterial diseases

  1. 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...

  2. 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

  3. 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.

  4. Foliar application of the leaf-colonizing yeast Pseudozyma churashimaensis elicits systemic defense of pepper against bacterial and viral pathogens

    PubMed Central

    Lee, Gahyung; Lee, Sang-Heon; Kim, Kyung Mo; Ryu, Choong-Min

    2017-01-01

    Yeast associates with many plant parts including the phyllosphere, where it is subject to harsh environmental conditions. Few studies have reported on biological control of foliar pathogens by yeast. Here, we newly isolated leaf-colonizing yeasts from leaves of field-grown pepper plants in a major pepper production area of South Korea. The yeast was isolated using semi-selective medium supplemented with rifampicin to inhibit bacterial growth and its disease control capacity against Xanthomonas axonopodis infection of pepper plants in the greenhouse was evaluated. Of 838 isolated yeasts, foliar spray of Pseudozyma churashimaensis strain RGJ1 at 108 cfu/mL conferred significant protection against X. axonopodis and unexpectedly against Cucumber mosaic virus, Pepper mottle virus, Pepper mild mottle virus, and Broad bean wilt virus under field conditions. Direct antagonism between strain RGJ1 and X. axonopodis was not detected from co-culture assays, suggesting that disease is suppressed via induced resistance. Additional molecular analysis of the induced resistance marker genes Capsicum annuum Pathogenesis-Related (CaPR) 4 and CaPR5 indicated that strain RGJ1 elicited plant defense priming. To our knowledge, this study is the first report of plant protection against bacterial and viral pathogens mediated by a leaf-colonizing yeast and has potential for effective disease management in the field. PMID:28071648

  5. Droplet fragmentation on leaves shapes foliar disease dispersal

    NASA Astrophysics Data System (ADS)

    Bourouiba, Lydia; Gilet, Tristan

    2015-11-01

    Although the dispersal of pathogens from plant to plant remains poorly understood, a strong statistical correlation exists between rainfall patterns and plant disease outbreaks. This correlation suggests that rain is a culprit in the dispersal of foliar pathogens. In this combined experimental and theoretical study, we unveil the mechanisms at play when a raindrop impacts an infected plant leaf. We identify two main fragmentation processes that shape rain-induced dispersal mechanisms. In both, pathogens are initially contained in water residues left on leaves by previous raindrops. As most leaves are partially wetting, residues take the shape of sessile drops. The impact of another raindrop in the vicinity triggers fragmentation of the sessile drop and subsequent ejection of contaminated droplets towards neighboring plants. Each scenario yields a different distribution of ejected droplets and brings a distinct contribution to the epidemic onset pattern. We show that leaf mechanical properties govern both fragmentation scenarios. Dimensionless parameters and scaling laws are provided to rationalize our observations.

  6. 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

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

    PubMed

    Gilet, T; Bourouiba, L

    2015-03-06

    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.

  8. 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...

  9. 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.

  10. 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...

  11. 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

  12. Low-Cost,Portable Multispectral Radiometer For Assessment Of Onset And Severity Of Foliar Disease Of Barley

    NASA Astrophysics Data System (ADS)

    Pederson, Vernyl D.; Nutter, Forrest W.

    1983-06-01

    A low-cost, hand-held multiband radiometer was used to measure reflected sunlight from barley canopies with varying levels of spot blotch, a foliar disease of barley. Spectrora-diometric measurements indicated that reflection of light in the .75 - .9 μm range was significantly less (P = < .01) from diseased canopies than from healthy ones. Yield of grain from the susceptible cultivar 'Larker' was correlated positively with amount of reflectance in the .75 - .9 μm range (P < .01). The results suggest the instrument may be useful for the objective assessment of foliar disease and the possible development of models to estimate losses from foliar disease.

  13. Bacteriophages and Bacterial Plant Diseases.

    PubMed

    Buttimer, Colin; McAuliffe, Olivia; Ross, R P; Hill, Colin; O'Mahony, Jim; Coffey, Aidan

    2017-01-01

    Losses in crop yields due to disease need to be reduced in order to meet increasing global food demands associated with growth in the human population. There is a well-recognized need to develop new environmentally friendly control strategies to combat bacterial crop disease. Current control measures involving the use of traditional chemicals or antibiotics are losing their efficacy due to the natural development of bacterial resistance to these agents. In addition, there is an increasing awareness that their use is environmentally unfriendly. Bacteriophages, the viruses of bacteria, have received increased research interest in recent years as a realistic environmentally friendly means of controlling bacterial diseases. Their use presents a viable control measure for a number of destructive bacterial crop diseases, with some phage-based products already becoming available on the market. Phage biocontrol possesses advantages over chemical controls in that tailor-made phage cocktails can be adapted to target specific disease-causing bacteria. Unlike chemical control measures, phage mixtures can be easily adapted for bacterial resistance which may develop over time. In this review, we will examine the progress and challenges for phage-based disease biocontrol in food crops.

  14. Bacteriophages and Bacterial Plant Diseases

    PubMed Central

    Buttimer, Colin; McAuliffe, Olivia; Ross, R. P.; Hill, Colin; O’Mahony, Jim; Coffey, Aidan

    2017-01-01

    Losses in crop yields due to disease need to be reduced in order to meet increasing global food demands associated with growth in the human population. There is a well-recognized need to develop new environmentally friendly control strategies to combat bacterial crop disease. Current control measures involving the use of traditional chemicals or antibiotics are losing their efficacy due to the natural development of bacterial resistance to these agents. In addition, there is an increasing awareness that their use is environmentally unfriendly. Bacteriophages, the viruses of bacteria, have received increased research interest in recent years as a realistic environmentally friendly means of controlling bacterial diseases. Their use presents a viable control measure for a number of destructive bacterial crop diseases, with some phage-based products already becoming available on the market. Phage biocontrol possesses advantages over chemical controls in that tailor-made phage cocktails can be adapted to target specific disease-causing bacteria. Unlike chemical control measures, phage mixtures can be easily adapted for bacterial resistance which may develop over time. In this review, we will examine the progress and challenges for phage-based disease biocontrol in food crops. PMID:28163700

  15. 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

  16. Strategies for managing foliar and root rot diseases of alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diseases can be a major source of yield loss and stand decline in alfalfa. Surveys were conducted to determine the distribution of pathogens for which there is limited resistance in commercial varieties and tests were done with new crop chemicals to determine their effectiveness in controlling sever...

  17. Bacterial diseases in marine bivalves.

    PubMed

    Travers, Marie-Agnès; Boettcher Miller, Katherine; Roque, Ana; Friedman, Carolyn S

    2015-10-01

    Bivalve aquaculture is seriously affected by many bacterial pathogens that cause high losses in hatcheries as well as in natural beds. A number of Vibrio species, but also members of the genera Nocardia and Roseovarius, are considered important pathogens in aquaculture. The present work provides an updated overview of main diseases and implicated bacterial species affecting bivalves. This review focuses on aetiological agents, their diversity and virulence factors, the diagnostic methods available as well as information on the dynamics of the host-parasite relationship.

  18. 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

  19. Lignasan for bacterial gill disease

    USGS Publications Warehouse

    Rucker, Robert R.; B.J., Earp; Burrows, Roger E.

    1956-01-01

    Bacterial gill disease plagues salmon and trout in many hatcheries: some infections are sporadic, but others are continual. An inexpensive, easily applied, stable, safe chemical would be highly advantageous for treatment. The use of Roccal as a 1-hour treatment for bacterial gill disease (Fish 1947) was developed at the Leavenworth (Washington) Station of the Fish and Wildlife Service in 1942 and was quite successful. Since then, Roccal has been used extensively; but because of variability in composition, its efficacy is not consistent (Rucker et al. 1949). The objection to the variability of Roccal was overcome by using another compound, pyridylmercuric acetate, which was suggested by Van Horn and Katz (1946) as having some therapeutic therapy. Pyridylmercuric acetate was tested experimentally at the Leavenworth Station and was found to be very effective for bacterial gill disease. This compound had highly differential toxicities for bacteria and fish but was quite expensive (Rucker 1948, Burrows and Palmer 1949, Snieszko 1949). Another objection to pyridylmercuric acedate was its toxicity to rainbow trout—not to other species of trout or to salmon—at the concentration necessary to control the bacteria (Seaman 1950, Rodgers et al. 1951, Bryant 1951, Foster and Olson 1951).

  20. Rhizosphere bacterial community composition responds to arbuscular mycorrhiza, but not to reductions in microbial activity induced by foliar cutting.

    PubMed

    Vestergård, Mette; Henry, Frédéric; Rangel-Castro, Juan Ignacio; Michelsen, Anders; Prosser, James I; Christensen, Søren

    2008-04-01

    Differences in bacterial community composition (BCC) between bulk and rhizosphere soil and between rhizospheres of different plant species are assumed to be strongly governed by quantitative and qualitative rhizodeposit differences. However, data on the relationship between rhizodeposit amounts and BCC are lacking. Other soil microorganisms, e.g. arbuscular mycorrhizal fungi (AMF), may also influence BCC. We simulated foliar herbivory (cutting) to reduce belowground carbon allocation and rhizodeposition of pea plants grown either with or without AMF. This reduced soil respiration, rhizosphere microbial biomass and bacteriovorous protozoan abundance, whereas none of these were affected by AMF. After labelling plants with (13)CO(2), root and rhizosphere soil (13)C enrichment of cut plants were reduced to a higher extent (24-46%) than shoot (13)C enrichment (10-24%). AMF did not affect (13)C enrichment. Despite these clear indications of reduced rhizosphere carbon-input, denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes PCR-amplified targeting DNA and RNA from rhizosphere soil did not reveal any effects of cutting on banding patterns. In contrast, AMF induced consistent differences in both DNA- and RNA-based DGGE profiles. These results show that a reduction in rhizosphere microbial activity is not necessarily accompanied by changes in BCC, whereas AMF presence inhibits proliferation of some bacterial taxa while stimulating others.

  1. 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

  2. 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.

  3. Foliar application of β-D-glucan nanoparticles to control rhizome rot disease of turmeric.

    PubMed

    Anusuya, Sathiyanarayanan; Sathiyabama, Muthukrishnan

    2015-01-01

    The soilborne Oomycete Pythium aphanidermatum is the causal agent of rhizome rot disease, one of the most serious threats to turmeric crops. At present, effective fungicides are not available. Researches on nanoparticles in a number of crops have evidenced the positive changes in gene expression indicating their potential use in crop improvement. Hence, experiments were carried out to determine the effect of β-D-glucan nanoparticles (nanobiopolymer) in protection of turmeric plants against rot disease by the way of products that reinforce plant's own defense mechanism. Foliar spray of β-D-glucan nanoparticles (0.1%, w/v) elicited marked increase in the activity of defense enzymes such as peroxidases (E.C.1.11.1.7), polyphenol oxidases (E.C.1.14.18.1), protease inhibitors (E.C.3.4.21.1) and β-1,3-glucanases (E.C.3.2.1.39) at various age levels. Constitutive and induced isoforms of these enzymes were investigated during this time-course study. β-D-glucan nanoparticles (GNPs) significantly reduced the rot incidence offering 77% protection. Increased activities of defense enzymes in GNPs-applied turmeric plants may play a role in restricting the development of disease symptoms. These results demonstrated that GNPs could be used as an effective resistance activator in turmeric for control of rhizome rot disease.

  4. 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...

  5. 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 ...

  6. 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...

  7. Bacterial diseases of crabs: a review.

    PubMed

    Wang, W

    2011-01-01

    Bacterial diseases of crabs are manifested as bacteremias caused by organisms such as Vibrio, Aeromonas, and a Rhodobacteriales-like organism or tissue and organ tropic organisms such as chitinoclastic bacteria, Rickettsia intracellular organisms, Chlamydia-like organism, and Spiroplasma. This paper provides general information about bacterial diseases of both marine and freshwater crabs. Some bacteria pathogens such as Vibrio cholerae and Vibrio vulnificus occur commonly in blue crab haemolymph and should be paid much attention to because they may represent potential health hazards to human beings because they can cause serious diseases when the crab is consumed as raw sea food. With the development of aquaculture, new diseases associated with novel pathogens such as spiroplasmas and Rhodobacteriales-like organisms have appeared in commercially exploited crab species in recent years. Many potential approaches to control bacterial diseases of crab will be helpful and practicable in aquaculture.

  8. The bacterial microbiota in inflammatory lung diseases.

    PubMed

    Huffnagle, Gary B; Dickson, Robert P

    2015-08-01

    Numerous lines of evidence, ranging from recent studies back to those in the 1920s, have demonstrated that the lungs are NOT bacteria-free during health. We have recently proposed that the entire respiratory tract should be considered a single ecosystem extending from the nasal and oral cavities to the alveoli, which includes gradients and niches that modulate microbiome dispersion, retention, survival and proliferation. Bacterial exposure and colonization of the lungs during health is most likely constant and transient, respectively. Host microanatomy, cell biology and innate defenses are altered during chronic lung disease, which in turn, alters the dynamics of bacterial turnover in the lungs and can lead to longer term bacterial colonization, as well as blooms of well-recognized respiratory bacterial pathogens. A few new respiratory colonizers have been identified by culture-independent methods, such as Pseudomonas fluorescens; however, the role of these bacteria in respiratory disease remains to be determined.

  9. The bacterial diseases of fish

    USGS Publications Warehouse

    Fish, F.F.

    1935-01-01

    Of all the diseases responsible for the losses in the hatchery, those caused by the microscopic one-celled organisms, the bacteria, are the most common and present the most serious problem to the hatcheryman. They are found at practically every trout and salmon hatchery during some period of the year. The symptoms of the diseases they cause are difficult to recognize. This in itself is a hazard because treatment, to be successful, must be applied during the early stages or, in cases where no method of treatment is effective, the infected fish must be destroyed before the disease spreads to other parts of the hatchery. Here we have a group of diseases practically universal in distribution, difficult to recognize, and hard to treat even in those cases where a remedy is known. Every hatcheryman should be well acquainted with them for efficient and intelligent control. There follows a brief summary of the present status of our knowledge of the individual diseases.

  10. Bacterial and parasitic diseases of selected invertebrates.

    PubMed

    Klaphake, Eric

    2009-09-01

    Invertebrate medicine is a rapidly advancing aspect of veterinary medicine, although frustrating in its lack of answers and its limitations compared with vertebrate medicine. Because invertebrates make up 98% of animal life, it should be impossible to contain information on their known bacterial and parasitic diseases within a single article. When the focus is placed on those species commonly kept and treated by non-marine veterinarians, the amount of information becomes manageable. Many exotic species had their known diseases and treatments start this way and then advanced to a higher level of understanding. This article stands as an introduction to the parasitic and bacterial diseases of these fascinating creatures for the veterinary practitioner.

  11. Invasive bacterial diseases in northern Canada.

    PubMed

    Degani, Naushaba; Navarro, Christine; Deeks, Shelley L; Lovgren, Marguerite

    2008-01-01

    International Circumpolar Surveillance (ICS) is a population-based invasive bacterial disease surveillance network. Participating Canadian regions include Yukon, Northwest Territories, Nunavut, and northern regions of Québec and Labrador (total population 132,956, 59% aboriginal). Clinical and demographic information were collected by using standardized surveillance forms. Bacterial isolates were forwarded to reference laboratories for confirmation and serotyping. After pneumococcal conjugate vaccine introduction, crude annual incidence rates of invasive Streptococcus pneumoniae decreased from 34.0/100,000 population (1999-2002) to 23.6/100,000 population (2003-2005); substantial reductions were shown among aboriginals. However, incidence rates of S. pneumoniae, Haemophilus influenzae, and group A streptococci were higher in aboriginal populations than in non-aboriginal populations. H. influenzae type b was rare; 52% of all H. influenzae cases were caused by type a. Data collected by ICS contribute to the understanding of the epidemiology of invasive bacterial diseases among northern populations, which assists in formulation of prevention and control strategies, including immunization recommendations.

  12. Vaccination against bacterial kidney disease: Chapter 22

    USGS Publications Warehouse

    Elliott, Diane G.; Wiens, Gregory D.; Hammell, K. Larry; Rhodes, Linda D.; Edited by Gudding, Roar; Lillehaug, Atle; Evensen, Øystein

    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.

  13. 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.

  14. Does bacterial vaginosis cause pelvic inflammatory disease?

    PubMed

    Taylor, Brandie DePaoli; Darville, Toni; Haggerty, Catherine L

    2013-02-01

    Pelvic inflammatory disease (PID), the infection and inflammation of the female genital tract, results in serious reproductive morbidity including infertility and ectopic pregnancy. Bacterial vaginosis (BV) is a complex alteration of the vaginal flora that has been implicated in PID. The role of BV in the etiology and pathogenesis of PID has not been studied extensively. Our objective was to extensively review data related to the relationship between BV and PID (n = 19 studies). Several studies found a link between BV and cervicitis, endometritis, and salpingitis. Furthermore, it seems that some BV-associated organisms are associated with PID, whereas others are not. However, studies demonstrating an independent association between BV-associated organisms and PID are sparse. In addition, a causal association between BV and PID has not been established. Prospective studies are needed to further delineate the role of BV in PID, with particular focus on individual BV-associated organisms.

  15. [Acute bacterial meningitis as an occupational disease].

    PubMed

    Seixas, Diana; Lebre, Ana; Crespo, Pedro; Ferreira, Eugénia; Serra, José Eduardo; Saraiva da Cunha, José Gabriel

    2014-01-01

    Streptococcus suis is a zoonotic pathogen with worldwide distribution, responsible for more than 700 human cases globally reported. This infection affects mostly men, exposed to pig or pork, which leads to its usual classification as an occupational disease. We report a case of acute bacterial meningitis in a 44 years old male. According to his past medical history, the patient had chronic alcoholism and worked in a restaurant as a piglet roaster. Microbiological examination of blood and CSF revealed S. suis. After 14 days of ceftriaxone the patient fully recovered. The authors review the clinical reports previously described in Portugal. In all of them was possible to identify risk exposition to pork. We alert to this microorganism's importance in Portugal where it is probably underdiagnosed.

  16. Managing foliar and root rot diseases of alfalfa for improving yield and persistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance to the six most common diseases across the United States is available in modern alfalfa cultivars. However, several diseases are becoming increasing problems in many parts of the country. Recognizing these problems is the first step in using crop management strategies to minimize diseases...

  17. Efficiency of circulant diallels via mixed models in the selection of papaya genotypes resistant to foliar fungal diseases.

    PubMed

    Vivas, M; Silveira, S F; Viana, A P; Amaral, A T; Cardoso, D L; Pereira, M G

    2014-07-02

    Diallel crossing methods provide information regarding the performance of genitors between themselves and their hybrid combinations. However, with a large number of parents, the number of hybrid combinations that can be obtained and evaluated become limited. One option regarding the number of parents involved is the adoption of circulant diallels. However, information is lacking regarding diallel analysis using mixed models. This study aimed to evaluate the efficacy of the method of linear mixed models to estimate, for variable resistance to foliar fungal diseases, components of general and specific combining ability in a circulant table with different s values. Subsequently, 50 diallels were simulated for each s value, and the correlations and estimates of the combining abilities of the different diallel combinations were analyzed. The circulant diallel method using mixed modeling was effective in the classification of genitors regarding their combining abilities relative to the complete diallels. The numbers of crosses in which each genitor(s) will compose the circulant diallel and the estimated heritability affect the combining ability estimates. With three crosses per parent, it is possible to obtain good concordance (correlation above 0.8) between the combining ability estimates.

  18. Application of glycerol as a foliar spray activates the defence response and enhances disease resistance of Theobroma cacao.

    PubMed

    Zhang, Yufan; Smith, Philip; Maximova, Siela N; Guiltinan, Mark J

    2015-01-01

    Previous work has implicated glycerol-3-phosphate (G3P) as a mobile inducer of systemic immunity in plants. We tested the hypothesis that the exogenous application of glycerol as a foliar spray might enhance the disease resistance of Theobroma cacao through the modulation of endogenous G3P levels. We found that exogenous application of glycerol to cacao leaves over a period of 4 days increased the endogenous level of G3P and decreased the level of oleic acid (18:1). Reactive oxygen species (ROS) were produced (a marker of defence activation) and the expression of many pathogenesis-related genes was induced. Notably, the effects of glycerol application on G3P and 18:1 fatty acid content, and gene expression levels, in cacao leaves were dosage dependent. A 100 mm glycerol spray application was sufficient to stimulate the defence response without causing any observable damage, and resulted in a significantly decreased lesion formation by the cacao pathogen Phytophthora capsici; however, a 500 mm glycerol treatment led to chlorosis and cell death. The effects of glycerol treatment on the level of 18:1 and ROS were constrained to the locally treated leaves without affecting distal tissues. The mechanism of the glycerol-mediated defence response in cacao and its potential use as part of a sustainable farming system are discussed.

  19. 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

  20. 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

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

    PubMed

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

    2014-12-01

    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.

  2. Using community analysis to explore bacterial indicators for disease suppression of tobacco bacterial wilt

    PubMed Central

    Liu, Xiaojiao; Zhang, Shuting; Jiang, Qipeng; Bai, Yani; Shen, Guihua; Li, Shili; Ding, Wei

    2016-01-01

    Although bacterial communities play important roles in the suppression of pathogenic diseases and crop production, little is known about the bacterial communities associated with bacterial wilt. Based on 16S rRNA gene sequencing, statistical analyses of microbial communities in disease-suppressive and disease-conducive soils from three districts during the vegetation period of tobacco showed that Proteobacteria was the dominant phylum, followed by Acidobacteria. Only samples from September were significantly correlated to disease factors. Fifteen indicators from taxa found in September (1 class, 2 orders, 3 families and 9 genera) were identified in the screen as being associated with disease suppression, and 10 of those were verified for potential disease suppression in March. Kaistobacter appeared to be the genus with the most potential for disease suppression. Elucidating microbially mediated natural disease suppression is fundamental to understanding microecosystem responses to sustainable farming and provides a possible approach for modeling disease-suppressive indicators. Here, using cluster analysis, MRPP testing, LEfSe and specific filters for a Venn diagram, we provide insight into identifying possible indicators of disease suppression of tobacco bacterial wilt. PMID:27857159

  3. [Pseudomonas syringae - the agent of bacterial diseases of weeds].

    PubMed

    Pasichnik, L A; Savenko, E A; Butsenko, L N; Shcherbina, T N; Patyka, V F

    2013-01-01

    The symptoms of bacterial diseases of the associated weeds have been identified and described in the wheat crops grown in different farming systems. On the basis of its morphological, biochemical and serological properties the agent isolated from frost-blite, barnyard grass, wild radish, couch grass, bottle-brush, bindweed and sow thistle has been identified as Pseudomonas syringae. Serological affinity between the weed bacteria and the agent of bacterial diseases of cereals has been established.

  4. Bacterial disease management: challenges, experience, innovation and future prospects: Challenges in Bacterial Molecular Plant Pathology.

    PubMed

    Sundin, George W; Castiblanco, Luisa F; Yuan, Xiaochen; Zeng, Quan; Yang, Ching-Hong

    2016-12-01

    Plant diseases caused by bacterial pathogens place major constraints on crop production and cause significant annual losses on a global scale. The attainment of consistent effective management of these diseases can be extremely difficult, and management potential is often affected by grower reliance on highly disease-susceptible cultivars because of consumer preferences, and by environmental conditions favouring pathogen development. New and emerging bacterial disease problems (e.g. zebra chip of potato) and established problems in new geographical regions (e.g. bacterial canker of kiwifruit in New Zealand) grab the headlines, but the list of bacterial disease problems with few effective management options is long. The ever-increasing global human population requires the continued stable production of a safe food supply with greater yields because of the shrinking areas of arable land. One major facet in the maintenance of the sustainability of crop production systems with predictable yields involves the identification and deployment of sustainable disease management solutions for bacterial diseases. In addition, the identification of novel management tactics has also come to the fore because of the increasing evolution of resistance to existing bactericides. A number of central research foci, involving basic research to identify critical pathogen targets for control, novel methodologies and methods of delivery, are emerging that will provide a strong basis for bacterial disease management into the future. Near-term solutions are desperately needed. Are there replacement materials for existing bactericides that can provide effective disease management under field conditions? Experience should inform the future. With prior knowledge of bactericide resistance issues evolving in pathogens, how will this affect the deployment of newer compounds and biological controls? Knowledge is critical. A comprehensive understanding of bacterial pathosystems is required to not

  5. 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.

  6. 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

  7. 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

  8. 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...

  9. Major bacterial diseases in aquaculture and their vaccine development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaculture is emerging as the fastest growing food-producing industry in the world due to the increasing demand for food fish consumption. However, the intensive culture of food fish has led to outbreaks of various bacterial diseases, resulting in annual economic losses to the aquaculture industry ...

  10. Bacterial Community Associated with Black Band Disease in Corals

    PubMed Central

    Frias-Lopez, Jorge; Klaus, James S.; Bonheyo, George T.; Fouke, Bruce W.

    2004-01-01

    Black band disease (BBD) is a virulent polymicrobial disease primarily affecting massive-framework-building species of scleractinian corals. While it has been well established that the BBD bacterial mat is dominated by a cyanobacterium, the quantitative composition of the BBD bacterial mat community has not described previously. Terminal-restriction fragment length polymorphism (T-RFLP) analysis was used to characterize the infectious bacterial community of the bacterial mat causing BBD. These analyses revealed that the bacterial composition of the BBD mat does not vary between different coral species but does vary when different species of cyanobacteria are dominant within the mat. On the basis of the results of a new method developed to identify organisms detected by T-RFLP analysis, our data show that besides the cyanobacterium, five species of the division Firmicutes, two species of the Cytophaga-Flexibacter-Bacteroides (CFB) group, and one species of δ-proteobacteria are also consistently abundant within the infectious mat. Of these dominant taxa, six were consistently detected in healthy corals. However, four of the six were found in much higher numbers in BBD mats than in healthy corals. One species of the CFB group and one species of Firmicutes were not always associated with the bacterial communities present in healthy corals. Of the eight dominant bacteria identified, two species were previously found in clone libraries obtained from BBD samples; however, these were not previously recognized as important. Furthermore, despite having been described as an important component of the pathogenetic mat, a Beggiatoa species was not detected in any of the samples analyzed. These results will permit the dominant BBD bacteria to be targeted for isolation and culturing experiments aimed at deciphering the disease etiology. PMID:15466538

  11. Rhizobacteria Bacillus subtilis restricts foliar pathogen entry through stomata.

    PubMed

    Kumar, Amutha Sampath; Lakshmanan, Venkatachalam; Caplan, Jeffrey L; Powell, Deborah; Czymmek, Kirk J; Levia, Delphis F; Bais, Harsh P

    2012-11-01

    Plants exist in a complex multitrophic environment, where they interact with and compete for resources with other plants, microbes and animals. Plants have a complex array of defense mechanisms, such as the cell wall being covered with a waxy cuticle serving as a potent physical barrier. Although some pathogenic fungi infect plants by penetrating through the cell wall, many bacterial pathogens invade plants primarily through stomata on the leaf surface. Entry of the foliar pathogen, Pseudomonas syringae pathovar tomato DC3000 (hereafter PstDC3000), into the plant corpus occurs through stomatal openings, and consequently a key plant innate immune response is the transient closure of stomata, which delays disease progression. Here, we present evidence that the root colonization of the rhizobacteria Bacillus subtilis FB17 (hereafter FB17) restricts the stomata-mediated pathogen entry of PstDC3000 in Arabidopsis thaliana. Root binding of FB17 invokes abscisic acid (ABA) and salicylic acid (SA) signaling pathways to close light-adapted stomata. These results emphasize the importance of rhizospheric processes and environmental conditions as an integral part of the plant innate immune system against foliar bacterial infections.

  12. Microbiome and metabolic disease: revisiting the bacterial phylum Bacteroidetes.

    PubMed

    Johnson, Elizabeth L; Heaver, Stacey L; Walters, William A; Ley, Ruth E

    2017-01-01

    Bacterial species composition in the gut has emerged as an important factor in obesity and its related metabolic diseases such as type 2 diabetes. Out of thousands of bacterial species-level phylotypes inhabiting the human gut, the majority belong to two dominant phyla, the Bacteroidetes and Firmicutes. Members of the Bacteroidetes in particular have been associated with human metabolic diseases. However, their associations with disease are not always consistent between studies. Delving deeper into the diversity within the Bacteroidetes reveals a vast diversity in genomes and capacities, which partly explain how not all members respond equally to similar environmental conditions in their hosts. Here, we discuss the Bacteroidetes phylum, associations of its members with metabolic phenotypes, and efforts to characterize functionally their interactions with their hosts. Harnessing the Bacteroidetes to promote metabolic health will require a nuanced understanding of how specific strains interact with their microbial neighbors and their hosts under various conditions.

  13. [Bacterial virulence in the etiology of periodontal diseases].

    PubMed

    Sbordone, L; Di Genio, M; Bortolaia, C

    2000-10-01

    Strong relationships have been very often described between various form of periodontal disease (PD) and certain bacterial species, so that nowadays periodontal disease is recognized as an infectious disease. Destruction of periodontal supporting tissues happens as a response to very intricate host-parasite interactions. When the clinician will be able to fully understand and identify such phenomena it would be possible to succeed in a properly diagnosis and control of the active phase of periodontal disease. The first step in such a direction would be to analyze the common characteristic of some bacterial species, the so called suspected periodontopathogens. Such species namely Gram-negative, associated with the outbreak of periodontal disease have in common the capacity to disrupt the integrity of the host defences by means of the so called virulence factors. These factors may enhance the bacterial colonization or may interfere with the host response that ultimately results in periodontal support breakdown. The present review focuses on the virulence factors of the main suspected periodontopathogens evaluating the effects on the host immune response and directly on the periodontal tissues.

  14. 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.

  15. Variations in bacterial communities during foliar litter decomposition in the winter and growing seasons in an alpine forest of the eastern Tibetan Plateau.

    PubMed

    Zhao, Yeyi; Wu, Fuzhong; Yang, Wanqin; Tan, Bo; He, Wei

    2016-01-01

    Bacterial communities are the primary engineers during litter decomposition and related material cycling, and they can be strongly controlled by seasonal changes in temperature and other environmental factors. However, limited information is available on changes in the bacterial community from winter to the growing season as litter decomposition proceeds in cold climates. Here, we investigated the abundance and structure of bacterial communities using real-time quantitative PCR and denaturing gradient gel electrophoresis (DGGE) during a 2-year field study of the decomposition of litter of 4 species in the winter and growing seasons of an alpine forest of the eastern Tibetan Plateau. The abundance of the bacterial 16S rRNA gene was relatively high during decomposition of cypress and birch litter in the first winter, but for the other litters 16S rRNA abundance during both winters was significantly lower than during the following growing season. A large number of bands were observed on the DGGE gels, and their intensities and number from the winter samples were lower than those from the growing season during the 2-year decomposition experiment. Eighty-nine sequences from the bands of bacteria that had been cut from the DGGE gels were affiliated with 10 distinct classes of bacteria and an unknown group. A redundancy analysis indicated that the moisture, mass loss, and elemental content (e.g., C, N, and P) of the litter significantly affected the bacterial communities. Collectively, the results suggest that uneven seasonal changes in climate regulate bacterial communities and other decomposers, thus affecting their contribution to litter decomposition processes in the alpine forest.

  16. Tracking the Remodeling of SNOMED CT's Bacterial Infectious Diseases.

    PubMed

    Ochs, Christopher; Case, James T; Perl, Yehoshua

    2016-01-01

    SNOMED CT's content undergoes many changes from one release to the next. Over the last year SNOMED CT's Bacterial infectious disease subhierarchy has undergone significant editing to bring consistent modeling to its concepts. In this paper we analyze the stated and inferred structural modifications that affected the Bacterial infectious disease subhierarchy between the Jan 2015 and Jan 2016 SNOMED CT releases using a two-phased approach. First, we introduce a methodology for creating a human readable list of changes. Next, we utilize partial-area taxonomies, which are compact summaries of SNOMED CT's content and structure, to identify the "big picture" changes that occurred in the subhierarchy. We illustrate how partial-area taxonomies can be used to help identify groups of concepts that were affected by these editing operations and the nature of these changes. Modeling issues identified using our two-phase methodology are discussed.

  17. Comparative molecular analysis of bacterial species associated with periodontal disease.

    PubMed

    De Iuliis, V; Ursi, S; Di Tommaso, L M; Caruso, M; Marino, A; D Ercole, S; Caputi, S; Sinjari, B; Festa, F; Macri, M; Martinotti, S; Vitullo, G; Toniato, E

    2016-01-01

    Periodontal disease is an inflammatory disorder affecting the supporting teeth structures, including gingiva, periodontal ligament and alveolar bone, causing loss of connective tissue, reabsorption of alveolar bone and formation of periodontal pockets. The aim of this study is to find a correlation between bacterial growth and periodontal disease. Fifty-seven patients aged between 21 and 65 years, median age 46 years, were enrolled. According to gingival pocket depth, ranging from 3 to 7 mm, patients were divided into two groups: the first (30 patients, 53%) with deep pockets ³ 5 mm and the second (27 patients, 47%) less than 5 mm. The samples taken were processed for microbiological analysis by absolute quantitative real-time Taq-Man technique. Patients affected by periodontal disease were 32 (56%) and patients with gingival bleeding were 35 (61%). This data showed that the presence, the type and the bacterial load in gingival pockets were strongly correlated with gingival depth, periodontal disease and gingival bleeding. Quantitative microbiological analysis is a key point to improve patient compliance, allowing to choose the specific antibiotic treatment. avoiding antibiotic resistance and ensuring the successful outcome of therapy for periodontal disease.

  18. 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

  19. Bacterial protein signals are associated with Crohn’s disease

    PubMed Central

    Juste, Catherine; Kreil, David P; Beauvallet, Christian; Guillot, Alain; Vaca, Sebastian; Carapito, Christine; Mondot, Stanislas; Sykacek, Peter; Sokol, Harry; Blon, Florence; Lepercq, Pascale; Levenez, Florence; Valot, Benoît; Carré, Wilfrid; Loux, Valentin; Pons, Nicolas; David, Olivier; Schaeffer, Brigitte; Lepage, Patricia; Martin, Patrice; Monnet, Véronique; Seksik, Philippe; Beaugerie, Laurent; Ehrlich, S Dusko; Gibrat, Jean-François; Van Dorsselaer, Alain; Doré, Joël

    2014-01-01

    Objective No Crohn’s disease (CD) molecular maker has advanced to clinical use, and independent lines of evidence support a central role of the gut microbial community in CD. Here we explore the feasibility of extracting bacterial protein signals relevant to CD, by interrogating myriads of intestinal bacterial proteomes from a small number of patients and healthy controls. Design We first developed and validated a workflow—including extraction of microbial communities, two-dimensional difference gel electrophoresis (2D-DIGE), and LC-MS/MS—to discover protein signals from CD-associated gut microbial communities. Then we used selected reaction monitoring (SRM) to confirm a set of candidates. In parallel, we used 16S rRNA gene sequencing for an integrated analysis of gut ecosystem structure and functions. Results Our 2D-DIGE-based discovery approach revealed an imbalance of intestinal bacterial functions in CD. Many proteins, largely derived from Bacteroides species, were over-represented, while under-represented proteins were mostly from Firmicutes and some Prevotella members. Most overabundant proteins could be confirmed using SRM. They correspond to functions allowing opportunistic pathogens to colonise the mucus layers, breach the host barriers and invade the mucosae, which could still be aggravated by decreased host-derived pancreatic zymogen granule membrane protein GP2 in CD patients. Moreover, although the abundance of most protein groups reflected that of related bacterial populations, we found a specific independent regulation of bacteria-derived cell envelope proteins. Conclusions This study provides the first evidence that quantifiable bacterial protein signals are associated with CD, which can have a profound impact on future molecular diagnosis. PMID:24436141

  20. 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.

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

    PubMed Central

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

    2015-01-01

    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

  2. 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...

  3. Gene Specific Impedimetric Bacterial DNA Sensor for Rheumatic Heart Disease.

    PubMed

    Singh, Swati; Kaushal, Ankur; Gupta, Sunil; Kumar, Ashok

    2017-03-01

    An impedimetric mga gene specific DNA sensor was developed by immobilization of single stranded DNA probe onto the screen printed modified gold-dendrimer nanohybrid composite electrode for early and rapid detection of S. pyogenes in human throat swab samples causing rheumatic heart disease. Electrochemical impedance response was measured after hybridization with bacterial single stranded genomic DNA (ssG-DNA) with probe. The sensor was found highly specific to S. pyogenes and can detect as low as 0.01 ng ssDNA in 6 µL sample only in 30 min. The nanohybrid sensor was also tested with non-specific pathogens and characterized by FTIR. An early detection of the pathogen S. pyogenes in human can save damage of mitral and aortic heart valves (rheumatic heart disease) by proper medical care.

  4. Late Foliar Diseases in Wheat Crops Decrease Nitrogen Yield Through N Uptake Rather than Through Variations in N Remobilization

    PubMed Central

    Bancal, Marie-Odile; Roche, Romain; Bancal, Pierre

    2008-01-01

    Background and Aims French wheat grains may be of little value on world markets because they have low and highly variable grain protein concentrations (GPC). This nitrogen-yield to yield ratio depends on crop nitrogen (N) fertilization as well as on crop capacity to use N, which is known to vary with climate and disease severity. Here an examination is made of the respective roles that N remobilization and post-anthesis N uptake play in N yield variations; in particular, when wheat crops (Triticum aestivum) are affected by leaf rust (Puccinia triticina) and Septoria tritici blotch (teleomorph Mycosphaerella graminicola). Methods Data from a 4-year field experiment was used to analyse N yield variations in wheat crops grown either with a third or no late N fertilization. Natural aerial epidemics ensured a range of disease severity, and fungicide ensured disease-free control plots. The data set of Gooding et al. (2005, Journal of Agricultural Science 143: 503–518) was incorporated in order to enlarge the range of conditions. Key Results Post-anthesis N uptake accounted for a third of N yield whilst N remobilization accounted for two-thirds in all crops whether affected by diseases or not. However, variations in N yield were highly correlated with post-anthesis N uptake, more than with N remobilization, in diseased and also healthy crops. Furthermore, N remobilization did not significantly correlate with N yield in healthy crops. These findings matched data from studies using various wheat genotypes under various management and climatic conditions. Leaf area duration (LAD) accurately predicted N remobilization whether or not crops were diseased; in diseased crops, LAD also accurately predicted N uptake. Conclusions Under the experimental conditions, N yield variations were closely associated with post-anthesis N uptake in diseased but also in healthy crops. Understanding the respective roles of N uptake and N remobilization in the case of diseased and healthy crops

  5. Significant relationship between soil bacterial community structure and incidence of bacterial wilt disease under continuous cropping system.

    PubMed

    She, Siyuan; Niu, Jiaojiao; Zhang, Chao; Xiao, Yunhua; Chen, Wu; Dai, Linjian; Liu, Xueduan; Yin, Huaqun

    2017-03-01

    Soil bacteria are very important in biogeochemical cycles and play significant role in soil-borne disease suppression. Although continuous cropping is responsible for soil-borne disease enrichment, its effect on tobacco plant health and how soil bacterial communities change are yet to be elucidated. In this study, soil bacterial communities across tobacco continuous cropping time-series fields were investigated through high-throughput sequencing of 16S ribosomal RNA genes. The results showed that long-term continuous cropping could significantly alter soil microbial communities. Bacterial diversity indices and evenness indices decreased over the monoculture span and obvious variations for community structures across the three time-scale tobacco fields were detected. Compared with the first year, the abundances of Arthrobacter and Lysobacter showed a significant decrease. Besides, the abundance of the pathogen Ralstonia spp. accumulated over the monoculture span and was significantly correlated with tobacco bacterial wilt disease rate. Moreover, Pearson's correlation demonstrated that the abundance of Arthrobacter and Lysobacter, which are considered to be beneficial bacteria had significant negative correlation with tobacco bacterial wilt disease. Therefore, after long-term continuous cropping, tobacco bacterial wilt disease could be ascribed to the alteration of the composition as well as the structure of the soil microbial community.

  6. Cellulase from Trichoderma harzianum interacts with roots and triggers induced systemic resistance to foliar disease in maize

    PubMed Central

    Saravanakumar, Kandasamy; Fan, Lili; Fu, Kehe; Yu, Chuanjin; Wang, Meng; Xia, Hai; Sun, Jianan; Li, Yaqian; Chen, Jie

    2016-01-01

    Trichoderma harzianum is well known to exhibit induced systemic resistance (ISR) to Curvularia leaf spot. We previously reported that a C6 zinc finger protein (Thc6) is responsible for a major contribution to the ISR to the leaf disease, but the types of effectors and the signals mediated by Thc6 from Trichoderma are unclear. In this work, we demonstrated that two hydrolases, Thph1 and Thph2, from T. harzianum were regulated by Thc6. Furthermore, an electrophoretic mobility shift assay (EMSA) study revealed that Thc6 regulated mRNA expression by binding to GGCTAA and GGCTAAA in the promoters of the Thph1 and Thph2 genes, respectively. Moreover, the Thph1 and Thph2 proteins triggered the transient production of reactive oxygen species (ROS) and elevated the free cytosolic calcium levels in maize leaf. Furthermore, the genes related to the jasmonate/ethylene signaling pathway were up-regulated in the wild-type maize strain. However, the ΔThph1- or ΔThph2-deletion mutants could not activate the immune defense-related genes in maize to protect against leaf disease. Therefore, we conclude that functional Thph1 and Thph2 may be required in T. harzianum to activate ISR in maize. PMID:27830829

  7. Cellulase from Trichoderma harzianum interacts with roots and triggers induced systemic resistance to foliar disease in maize.

    PubMed

    Saravanakumar, Kandasamy; Fan, Lili; Fu, Kehe; Yu, Chuanjin; Wang, Meng; Xia, Hai; Sun, Jianan; Li, Yaqian; Chen, Jie

    2016-11-10

    Trichoderma harzianum is well known to exhibit induced systemic resistance (ISR) to Curvularia leaf spot. We previously reported that a C6 zinc finger protein (Thc6) is responsible for a major contribution to the ISR to the leaf disease, but the types of effectors and the signals mediated by Thc6 from Trichoderma are unclear. In this work, we demonstrated that two hydrolases, Thph1 and Thph2, from T. harzianum were regulated by Thc6. Furthermore, an electrophoretic mobility shift assay (EMSA) study revealed that Thc6 regulated mRNA expression by binding to GGCTAA and GGCTAAA in the promoters of the Thph1 and Thph2 genes, respectively. Moreover, the Thph1 and Thph2 proteins triggered the transient production of reactive oxygen species (ROS) and elevated the free cytosolic calcium levels in maize leaf. Furthermore, the genes related to the jasmonate/ethylene signaling pathway were up-regulated in the wild-type maize strain. However, the ΔThph1- or ΔThph2-deletion mutants could not activate the immune defense-related genes in maize to protect against leaf disease. Therefore, we conclude that functional Thph1 and Thph2 may be required in T. harzianum to activate ISR in maize.

  8. 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.

  9. Serum Procalcitonin for Differentiating Bacterial Infection from Disease Flares in Patients with Autoimmune Diseases

    PubMed Central

    Joo, Kowoon; Lim, Mie-Jin; Kwon, Seong-Ryul; Yoon, Jiyeol

    2011-01-01

    Early differentiation between bacterial infections and disease flares in autoimmune disease patients is important due to different treatments. Seventy-nine autoimmune disease patients with symptoms suggestive of infections or disease flares were collected by retrospective chart review. The patients were later classified into two groups, disease flare and infection. C-reactive protein (CRP) and serum procalcitonin (PCT) levels were measured. The CRP and PCT levels were higher in the infection group than the disease flare group (CRP,11.96 mg/dL ± 9.60 vs 6.42 mg/dL ± 7.01, P = 0.003; PCT, 2.44 ng/mL ± 6.55 vs 0.09 ng/mL ± 0.09, P < 0.001). The area under the ROC curve (AUC; 95% confidence interval) for CRP and PCT was 0.70 (0.58-0.82) and 0.84 (0.75-0.93), which showed a significant difference (P < 0.05). The predicted AUC for the CRP and PCT levels combined was 0.83, which was not significantly different compared to the PCT level alone (P = 0.80). The best cut-off value for CRP was 7.18 mg/dL, with a sensitivity of 71.9% and a specificity of 68.1%. The best cut-off value for PCT was 0.09 ng/mL, with a sensitivity of 81.3% and a specificity of 78.7%. The PCT level had better sensitivity and specificity compared to the CRP level in distinguishing between bacterial infections and disease flares in autoimmune disease patients. The CRP level has no additive value when combined with the PCT level when differentiating bacterial infections from disease flares. PMID:21935268

  10. Home Screening for Bacterial Vaginosis to Prevent Sexually Transmitted Diseases

    PubMed Central

    Schwebke, Jane R.; Lee, Jeannette Y.; Lensing, Shelly; Philip, Susan S.; Wiesenfeld, Harold C.; Seña, Arlene C.; Trainor, Nikole; Acevado, Nincoshka; Saylor, Lisa; Rompalo, Ann M.; Cook, Robert L.

    2016-01-01

    Background. Longitudinal studies have consistently found a significant association between bacterial vaginosis (BV) and acquisition of sexually transmitted diseases. However, there are limited prospective data to confirm these findings. Methods. We conducted a prospective, randomized, open-label trial of home screening and treatment of young women with asymptomatic BV who were also at high risk for sexually transmitted diseases. These women were screened every 2 months for 12 months and randomized to treatment with oral metronidazole 500 mg twice daily for 7 days or observation alone. The primary outcome was the incidence of gonorrhea and/or chlamydia. Results. A total of 1365 subjects were enrolled in the study across 10 sites. Adherence with mailing specimens obtained at home was excellent in both groups (84%–88%). The incidence of gonorrhea and/or chlamydia was 19.1 per 100 person-years (95% confidence interval, 15.1–22.1) for the treatment group and 18.5 per 100 person-years (15.1–22.8) for the observation arm, a difference that was not statistically significant. Conclusions. Young women were very amenable to home screening for BV, gonorrhea, and chlamydia. Treatment of asymptomatic BV with 1 week of oral metronidazole did not decrease the incidence of gonorrhea and/or chlamydia. Clinical Trials Registration. NCT00667368. PMID:26611782

  11. Gram-negative bacterial molecules associate with Alzheimer disease pathology

    PubMed Central

    Stamova, Boryana; Jin, Lee-Way; DeCarli, Charles; Phinney, Brett; Sharp, Frank R.

    2016-01-01

    Objective: We determined whether Gram-negative bacterial molecules are associated with Alzheimer disease (AD) neuropathology given that previous studies demonstrate Gram-negative Escherichia coli bacteria can form extracellular amyloid and Gram-negative bacteria have been reported as the predominant bacteria found in normal human brains. Methods: Brain samples from gray and white matter were studied from patients with AD (n = 24) and age-matched controls (n = 18). Lipopolysaccharide (LPS) and E coli K99 pili protein were evaluated by Western blots and immunocytochemistry. Human brain samples were assessed for E coli DNA followed by DNA sequencing. Results: LPS and E coli K99 were detected immunocytochemically in brain parenchyma and vessels in all AD and control brains. K99 levels measured using Western blots were greater in AD compared to control brains (p < 0.01) and K99 was localized to neuron-like cells in AD but not control brains. LPS levels were also greater in AD compared to control brain. LPS colocalized with Aβ1-40/42 in amyloid plaques and with Aβ1-40/42 around vessels in AD brains. DNA sequencing confirmed E coli DNA in human control and AD brains. Conclusions: E coli K99 and LPS levels were greater in AD compared to control brains. LPS colocalized with Aβ1-40/42 in amyloid plaques and around vessels in AD brain. The data show that Gram-negative bacterial molecules are associated with AD neuropathology. They are consistent with our LPS-ischemia-hypoxia rat model that produces myelin aggregates that colocalize with Aβ and resemble amyloid-like plaques. PMID:27784770

  12. 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

  13. Incidence and Predictors of Bacterial infection in Febrile Children with Sickle Cell Disease.

    PubMed

    Morrissey, Benita J; Bycroft, Thomas P; Almossawi, Ofran; Wilkey, Olufunke B; Daniels, Justin G

    2015-01-01

    Children with sickle cell disease are at increased risk of developing bacteremia and other serious bacterial infections. Fever is a common symptom in sickle cell disease and can also occur with sickle cell crises and viral infections. We aimed to evaluate the incidence and predictors of bacteremia and bacterial infection in children with sickle cell disease presenting with fever to a district hospital and sickle cell center in London. A retrospective analysis was performed on all attendances of children (aged under 16 years) with sickle cell disease presenting with a fever of 38.5 °C or higher over a 1-year period. Confirmed bacterial infection was defined as bacteremia, bacterial meningitis, urinary tract infection (UTI), pneumonia, osteomyelitis or other bacterial infection with positive identification of organism. Children were defined as having a suspected bacterial infection if a bacterial infection was suspected clinically, but no organism was identified. Over a 1-year period there were 88 episodes analyzed in 59 children. Bacteremia occurred in 3.4% of episodes and confirmed bacterial infection in 7.0%. Suspected bacterial infection occurred in 33.0%. One death occurred from Salmonella typhirium septicemia. C-reactive protein (CRP) level and white blood cell (WBC) count were both significantly associated with bacterial infection (p = 0.004 and 0.02, respectively.) In conclusion, bacterial infections continue to be a significant problem in children with sickle cell disease. C-reactive protein was significantly associated with bacterial infections, and could be included in clinical risk criteria for febrile children with sickle cell disease.

  14. 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...

  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.

  16. Contrasting Ecological Processes and Functional Compositions Between Intestinal Bacterial Community in Healthy and Diseased Shrimp.

    PubMed

    Zhu, Jinyong; Dai, Wenfang; Qiu, Qiongfen; Dong, Chunming; Zhang, Jinjie; Xiong, Jinbo

    2016-11-01

    Intestinal bacterial communities play a pivotal role in promoting host health; therefore, the disruption of intestinal bacterial homeostasis could result in disease. However, the effect of the occurrences of disease on intestinal bacterial community assembly remains unclear. To address this gap, we compared the multifaceted ecological differences in maintaining intestinal bacterial community assembly between healthy and diseased shrimps. The neutral model analysis shows that the relative importance of neutral processes decreases when disease occurs. This pattern is further corroborated by the ecosphere null model, revealing that the bacterial community assembly of diseased samples is dominated by stochastic processes. In addition, the occurrence of shrimp disease reduces the complexity and cooperative activities of species-to-species interactions. The keystone taxa affiliated with Alphaproteobacteria and Actinobacteria in healthy shrimp gut shift to Gammaproteobacteria species in diseased shrimp. Changes in intestinal bacterial communities significantly alter biological functions in shrimp. Within a given metabolic pathway, the pattern of enrichment or decrease between healthy and deceased shrimp is correlated with its functional effects. We propose that stressed shrimp are more prone to invasion by alien strains (evidenced by more stochastic assembly and higher migration rate in diseased shrimp), which, in turn, disrupts the cooperative activity among resident species. These findings greatly aid our understanding of the underlying mechanisms that govern shrimp intestinal community assembly between health statuses.

  17. 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...

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Contribution of gut bacterial metabolism to human metabolic disease.

    PubMed

    Bain, M D; Jones, M; Borriello, S P; Reed, P J; Tracey, B M; Chalmers, R A; Stacey, T E

    1988-05-14

    Metronidazole, an antibiotic with specific activity against anaerobic bacteria, was of clinical and biochemical benefit in two patients with methylmalonic aciduria. The virtual elimination of propionic acid from the stool suggested that propionic acid derived from faecal bacterial metabolism contributes substantially to methylmalonate production. These findings point to a novel avenue of treatment for these disorders of intermediary metabolism, and indicate the importance of microbial gut flora in normal human metabolism.

  3. 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

  4. 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...

  5. Penicillin Use in Meningococcal Disease Management: Active Bacterial Core Surveillance Sites, 2009

    PubMed Central

    Blain, Amy E.; Mandal, Sema; Wu, Henry; MacNeil, Jessica R.; Harrison, Lee H.; Farley, Monica M.; Lynfield, Ruth; Miller, Lisa; Nichols, Megin; Petit, Sue; Reingold, Arthur; Schaffner, William; Thomas, Ann; Zansky, Shelley M.; Anderson, Raydel; Harcourt, Brian H.; Mayer, Leonard W.; Clark, Thomas A.; Cohn, Amanda C.

    2016-01-01

    In 2009, in the Active Bacterial Core surveillance sites, penicillin was not commonly used to treat meningococcal disease. This is likely because of inconsistent availability of antimicrobial susceptibility testing and ease of use of third-generation cephalosporins. Consideration of current practices may inform future meningococcal disease management guidelines. PMID:27704009

  6. Penicillin Use in Meningococcal Disease Management: Active Bacterial Core Surveillance Sites, 2009.

    PubMed

    Blain, Amy E; Mandal, Sema; Wu, Henry; MacNeil, Jessica R; Harrison, Lee H; Farley, Monica M; Lynfield, Ruth; Miller, Lisa; Nichols, Megin; Petit, Sue; Reingold, Arthur; Schaffner, William; Thomas, Ann; Zansky, Shelley M; Anderson, Raydel; Harcourt, Brian H; Mayer, Leonard W; Clark, Thomas A; Cohn, Amanda C

    2016-09-01

    In 2009, in the Active Bacterial Core surveillance sites, penicillin was not commonly used to treat meningococcal disease. This is likely because of inconsistent availability of antimicrobial susceptibility testing and ease of use of third-generation cephalosporins. Consideration of current practices may inform future meningococcal disease management guidelines.

  7. 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

  8. Differential Control Efficacies of Vitamin Treatments against Bacterial Wilt and Grey Mould Diseases in Tomato Plants

    PubMed Central

    Hong, Jeum Kyu; Kim, Hyeon Ji; Jung, Heesoo; Yang, Hye Ji; Kim, Do Hoon; Sung, Chang Hyun; Park, Chang-Jin; Chang, Seog Won

    2016-01-01

    Bacterial wilt and grey mould in tomato plants are economically destructive bacterial and fungal diseases caused by Ralstonia solanacearum and Botrytis cinerea, respectively. Various approaches including chemical and biological controls have been attempted to arrest the tomato diseases so far. In this study, in vitro growths of bacterial R. solanacearum and fungal B. cinerea were evaluated using four different vitamins including thiamine (vitamin B1), niacin (vitamin B3), pyridoxine (vitamin B6), and menadione (vitamin K3). In planta efficacies of the four vitamin treatments on tomato protection against both diseases were also demonstrated. All four vitamins showed different in vitro antibacterial activities against R. solanacearum in dose-dependent manners. However, treatment with 2 mM thiamine was only effective in reducing bacterial wilt of detached tomato leaves without phytotoxicity under lower disease pressure (106 colony-forming unit [cfu]/ml). Treatment with the vitamins also differentially reduced in vitro conidial germination and mycelial growth of B. cinerea. The four vitamins slightly reduced the conidial germination, and thiamine, pyridoxine and menadione inhibited the mycelial growth of B. cinerea. Menadione began to drastically suppress the conidial germination and mycelial growth by 5 and 0.5 mM, respectively. Grey mould symptoms on the inoculated tomato leaves were significantly reduced by pyridoxine and menadione pretreatments one day prior to the fungal challenge inoculation. These findings suggest that disease-specific vitamin treatment will be integrated for eco-friendly management of tomato bacterial wilt and grey mould. PMID:27721697

  9. 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

  10. The Role of the Bacterial Microbiome in Lung Disease

    PubMed Central

    Dickson, Robert P.; Erb-Downward, John R.; Huffnagle, Gary B.

    2014-01-01

    Novel culture-independent techniques have recently demonstrated that the lower respiratory tract, historically considered sterile in health, contains diverse communities of microbes: the lung microbiome. A growing literature has demonstrated that a distinct microbiota of the lower respiratory tract is present both in health and in various respiratory diseases, though the biological and clinical significance of these findings remains undetermined. In this article, we review and synthesize published reports of the lung microbiota of healthy and diseased subjects, discuss trends of microbial diversity and constitution across disease states, and look to the extra-pulmonary microbiome for hypotheses and future directions for study. PMID:23734647

  11. 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

  12. 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.

  13. 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

  14. Quorum sensing and Bacterial Pathogenicity: From Molecules to Disease.

    PubMed

    Deep, Antariksh; Chaudhary, Uma; Gupta, Varsha

    2011-01-01

    Quorum sensing in prokaryotic biology refers to the ability of a bacterium to sense information from other cells in the population when they reach a critical concentration (i.e. a Quorum) and communicate with them. The "language" used for this intercellular communication is based on small, self-generated signal molecules called as autoinducers. Quorum sensing is thought to afford pathogenic bacteriaa mechanism to minimize host immune responses by delaying theproduction of tissue-damaging virulence factors until sufficientbacteria have amassed and are prepared to overwhelm host defensemechanisms and establish infection. Quorum sensing systems are studied in a large number of gram-negative bacterial species belonging to α, β, and γ subclasses of proteobacteria. Among the pathogenic bacteria, Pseudomonas aeruginosa is perhaps the best understood in terms of the virulence factors regulated and the role the Quorum sensing plays in pathogenicity. Presently, Quorum sensing is considered as a potential novel target for antimicrobial therapy to control multi/all drug-resistant infections. This paper reviews Quorum sensing in gram positive and gram negative bacteria and its role in biofilm formation.

  15. 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.

  16. 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.

  17. Role of long non-coding RNAs in bacterial cold water disease pathogenesis in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) caused by Flavobacterium psychrophilum is one of the major causes of mortality in salmonids. Three genetic lines of rainbow trout designated as ARS-Fp-R (resistant), ARS-Fp-C (control) and ARS-Fp-S (susceptible) have significant differences in survival rate follow...

  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. 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 ...

  20. 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...

  1. 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.

  2. Recent trends in control methods for bacterial wilt diseases caused by Ralstonia solanacearum.

    PubMed

    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.

  3. 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...

  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. 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

  6. Clinical characteristics and prognostic impact of bacterial infection in hospitalized patients with alcoholic liver disease.

    PubMed

    Park, Jin Kyoung; Lee, Chang Hun; Kim, In Hee; Kim, Seon Min; Jang, Ji Won; Kim, Seong Hun; Kim, Sang Wook; Lee, Seung Ok; Lee, Soo Teik; Kim, Dae-Ghon

    2015-05-01

    Bacterial infection is an important cause of death in patients with liver cirrhosis. The aim of this study was to investigate the clinical characteristics and prognostic impact of bacterial infection in hospitalized patients with alcoholic liver disease (ALD). We retrospectively analyzed data from 409 patients consecutively admitted to a tertiary referral center with ALD diagnosis. Of a total of 544 admissions, 133 (24.4%) cases presented with bacterial infection, of which 116 were community-acquired whereas 17 were hospital-acquired. The common types of infection were pneumonia (38%), biliary tract infection (17%), soft tissue infection (12%), and spontaneous bacterial peritonitis (9%). Diabetes, serum Na <135 mM/L, albumin <2.5 g/dL, C-reactive protein ≥20 mg/L, systemic inflammatory response syndrome (SIRS) positivity were independently associated with bacterial infection in patients with ALD. Overall 30-day and 90-day mortalities in patients with bacterial infection were significantly (P < 0.001) higher than those without infection (22.3% vs. 5.1% and 32.3% vs. 8.2%, respectively). Furthermore, bacterial infection (HR, 2.2; 95% CI, 1.049-4.579, P = 0.037), SIRS positivity (HR, 2.5; 95% CI, 1.240-4.861, P = 0.010), Maddrey's discriminant function score ≥32 (HR, 2.3; 95% CI, 1.036-5.222, P = 0.041), and hemoglobin <12 g/dL (HR, 2.4; 95% CI, 1.081-5.450, P = 0.032) were independent predictors of short-term mortality. In conclusion, bacterial infection and SIRS positivity predicted short-term prognosis in hospitalized patients with ALD. A thorough evaluation at admission or on clinical deterioration is required to detect possible infection with prompt management.

  7. 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

  8. 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

    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.

  9. 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

  10. [Understanding current practice of clinical medicine in the tropics (II). Bacterial and viral diseases. Malnutrition].

    PubMed

    Ramos, J M; de Górgolas, M; Cuadros, J; Fanjul, E

    2012-07-01

    In recent years, a significant number of physicians want to spend part of their medical training in health facilities in developing countries. In this setting, clinical skills are extremely important due to the limited available diagnostic resources. Bacterial diseases are common, but bacterial cultures are rarely accessible. In Africa, tuberculosis affects over 200 cases per 100,000 persons, and more than 22 million people live with HIV infection; both diseases are a serious public health problem. Malnutrition is endemic in many countries in Africa and is compounded by the continuous humanitarian and food crisis. In this paper, basic concepts of epidemiology, clinical features, diagnosis and treatment of major diseases that can be found in a rural health post in the tropics are discussed.

  11. Studying microbial pathogenesis and bacterial diseases. Interview by Hannah Branch.

    PubMed

    Finlay, B Brett

    2013-06-01

    B Brett Finlay speaks to Hannah Branch, Commissioning Editor B Brett Finlay is Professor in the Michael Smith Laboratories in addition to the Departments of Microbiology and Immunology, and Biochemistry and Molecular Biology at the University of British Columbia, Canada. He received a BSc (Honors) and a PhD (1986) in biochemistry at the University of Alberta, Canada. In 1989, he started work as Assistant Professor in the Biotechnology Laboratory at the University of British Colombia. He has focused his research on host-pathogen interactions at the molecular level. He has been at the forefront of the cellular microbiology field and contributed towards a number of important discoveries in this area while publishing over 400 manuscripts. Research in his laboratory is focused on, but not restricted to, Escherichia coli and Salmonella interactions with host cells. He is known across the globe for his research and has been honored with a number of prestigious awards, including the EWR Steacie Prize, the Canadian Society of Microbiology Fisher Scientific Award, a Medical Research Council scientist award, five Howard Hughes International Research Scholar Awards, a Canadian Institute of Health Research Distinguished Investigator award, British Columbia Biotech Innovation Award, the Michael Smith Health Research Prize, the Infectious Diseases Society of America Squibb award and the Jacob Biely Prize. He is a Fellow of the Royal Society of Canada and the Canadian Academy of Health Sciences, is an Officer of the Order of Canada, and is the University of British Columbia Peter Wall Distinguished Professor. He cofounded Inimex Pharmaceuticals, Inc. (BC, Canada), and is Director of the Severe Acute Respiratory Syndrome Accelerated Vaccine Initiative. He is also a valued member of several advisory and editorial boards, including that of Future Microbiology.

  12. Seasonal changes in bacterial communities associated with healthy and diseased Porites coral in southern Taiwan.

    PubMed

    Lin, Chorng-Horng; Chuang, Chih-Hsiang; Twan, Wen-Hung; Chiou, Shu-Fen; Wong, Tit-Yee; Liu, Jong-Kang; Kao, Chyuan-Yao; Kuo, Jimmy

    2016-12-01

    We compared the bacterial communities associated with healthy scleractinian coral Porites sp. with those associated with coral infected with pink spot syndrome harvested during summer and winter from waters off the coast of southern Taiwan. Members of the bacterial community associated with the coral were characterized by means of denaturing gradient gel electrophoresis (DGGE) of a short region of the 16S rRNA gene and clone library analysis. Of 5 different areas of the 16S rRNA gene, we demonstrated that the V3 hypervariable region is most suited to represent the coral-associated bacterial community. The DNA sequences of 26 distinct bands extracted from DGGE gels and 269 sequences of the 16S rRNA gene from clone libraries were determined. We found that the communities present in diseased coral were more heterogeneous than the bacterial communities of uninfected coral. In addition, bacterial communities associated with coral harvested in the summer were more diverse than those associated with coral collected in winter, regardless of the health status of the coral. Our study suggested that the compositions of coral-associated bacteria communities are complex, and the population of bacteria varies greatly between seasons and in coral of differing health status.

  13. Periductal Mastitis: An Inflammatory Disease Related to Bacterial Infection and Consequent Immune Responses?

    PubMed Central

    Liu, Lu; Zhou, Fei; Wang, Pin; Yu, Lixiang; Ma, Zhongbing; Li, Yuyang; Gao, Dezong; Zhang, Qiang

    2017-01-01

    Periductal mastitis (PDM) is a prolonged inflammatory disease, but the cause of PDM is poorly understood. In the present case control study, 87 PDM and 87 healthy controls were enrolled and the results were evaluated to identify the significant risk factors for PDM. To investigate the roles of bacterial infection and critical cytokines expression, 16S rRNA gene sequencing and bacterial culturing were conducted. We also measured the levels of interferon-γ, interleukin-12A, and interleukin-17A by semiquantitative immunohistochemistry method. In a multivariable logistic regression model, we identified overweight/obesity and late onset of menarche as independent risk factors for PDM. In contrast, age of first birth >27 years had a protective effect. With 16S rRNA gene sequencing, we confirmed bacterial infections were found in all PDM patients, but none of the control patients was positive on the gene expression of 16S rRNA. Our results also demonstrated significant increases of the IFN-γ and IL-12A expression in PDM, but there was no difference in IL-17A expression in these two groups. Taken together, this study suggests that reproductive factors and overweight/obesity are possible predisposing risk factors for PDM. Bacterial infection and the increased expression of some proinflammatory cytokines are associated with the pathogenesis of this disease. PMID:28182101

  14. Bacterial infection in chronic obstructive pulmonary disease in 2000: a state-of-the-art review.

    PubMed

    Sethi, S; Murphy, T F

    2001-04-01

    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.

  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. Tracking the Remodeling of SNOMED CT’s Bacterial Infectious Diseases

    PubMed Central

    Ochs, Christopher; Case, James T.; Perl, Yehoshua

    2016-01-01

    SNOMED CT’s content undergoes many changes from one release to the next. Over the last year SNOMED CT’s Bacterial infectious disease subhierarchy has undergone significant editing to bring consistent modeling to its concepts. In this paper we analyze the stated and inferred structural modifications that affected the Bacterial infectious disease subhierarchy between the Jan 2015 and Jan 2016 SNOMED CT releases using a two-phased approach. First, we introduce a methodology for creating a human readable list of changes. Next, we utilize partial-area taxonomies, which are compact summaries of SNOMED CT’s content and structure, to identify the “big picture” changes that occurred in the subhierarchy. We illustrate how partial-area taxonomies can be used to help identify groups of concepts that were affected by these editing operations and the nature of these changes. Modeling issues identified using our two-phase methodology are discussed. PMID:28269894

  18. Serum sialic acid in malignant tumors, bacterial infections, and chronic liver diseases.

    PubMed

    Stefenelli, N; Klotz, H; Engel, A; Bauer, P

    1985-01-01

    The total serum sialic acid concentration was determined in 2,264 persons with various malignant tumors, bacterial infections, rheumatic diseases, and chronic liver diseases, and in a control group. The thiobarbiturate method according to Warren was used. The upper limit (95% percentile) in the control group was 2.23 mumol/ml. Higher values were found in the groups with neoplasms (mean: 3.04 mumol/ml), inflammatory diseases (e.g., pneumonia: 3.02 mumol/ml), and active rheumatoid arthritis (3.05 mumol/ml). In the group with malignant diseases, the sialic acid concentration at the time of diagnosis was highest for bronchial carcinoma (3.29 mumol/ml) and lowest for breast cancer (2.58 mumol/ml). In chronic liver diseases the mean sialic acid level was lower than in a heterogeneous group of noninflammatory and nonneoplastic diseases. The estimation of the serum sialic acid concentration could be useful in the detection of tumor burden and metastases, and in the evaluation of the later course and prognosis of malignant neoplasms if bacterial/inflammatory and active rheumatoid processes can be excluded.

  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.

  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.

  1. Antibody repertoire profiling using bacterial display identifies reactivity signatures of celiac disease.

    PubMed

    Spatola, Bradley N; Murray, Joseph A; Kagnoff, Martin; Kaukinen, Katri; Daugherty, Patrick S

    2013-01-15

    A general strategy to identify serum antibody specificities associated with a given disease state and peptide reagents for their detection was developed using bacterial display peptide libraries and multiparameter flow cytometry (MPFC). Using sera from patients with celiac disease (CD) (n = 45) or healthy subjects (n = 40), bacterial display libraries were screened for peptides that react specifically with antibodies from CD patients and not with those from healthy patients. The libraries were screened for peptides that simultaneously cross-react with CD patient antibodies present in two separate patient groups labeled with spectrally distinct fluorophores but do not react with unlabeled non-CD antibodies, thus affording a quantitative separation. A panel of six unique peptide sequences yielded 85% sensitivity and 91% specificity (AUC = 0.91) on a set of 60 samples not used for discovery, using leave-one-out cross-validation. Individual peptides were dissimilar with known CD-specific antigens tissue transglutaminase (tTG) and deamidated gliadin, and the classifier accuracy was independent of anti-tTG antibody titer. These results demonstrate that bacterial display/MPFC provides a highly effective tool for the unbiased discovery of disease-associated antibody specificities and peptide reagents for their detection that may have broad utility for diagnostic development.

  2. Development and Validation of an Infection Risk Model for Bacterial Canker of Kiwifruit, Using a Multiplication and Dispersal Concept for Forecasting Bacterial Diseases.

    PubMed

    Beresford, R M; Tyson, J L; Henshall, W R

    2017-02-01

    A weather-based disease prediction model for bacterial canker of kiwifruit (known worldwide as Psa; Pseudomonas syringae pv. actinidiae biovar 3) was developed using a new mechanistic scheme for bacterial disease forecasters, the multiplication and dispersal concept. Bacterial multiplication is estimated from a temperature function, the M index, accumulated from hourly air temperature over 3 days for hours when the leaf canopy is wet. Rainfall provides free water to move inoculum to infection sites, and the daily risk indicator, the R index, is the 3-day accumulation of the M index output on days with total rainfall >1 mm; otherwise, R is zero. The model was field-tested using potted kiwifruit trap plants exposed for discrete periods in infected kiwifruit orchards to identify when leaf infection occurred. In a 9-week study during spring, the R index predicted leaf-spot intensity with high accuracy (R(2) = 93%) and, in an 82-week seasonal accuracy study, prediction of infection incidence was most accurate from spring to late summer and lower during other times. To implement the risk model for the New Zealand kiwifruit industry, a modified risk index, R', used relative humidity (RH) >81% instead of wetness, so that 2- and 6-day weather forecasts of RH could be used. Risk index values were affected by the shape of the temperature function and an alternative 'low temperature' function for the M index was identified that could be used in climates in which high temperatures are known to limit Psa development during some parts of the year. This study has shown how infection risk for bacterial diseases can be conceptualized as separate processes for temperature-dependent bacterial multiplication and rain-dependent dispersal and infection. This concept has potentially wide application for bacterial disease prediction in the same way that the infection monocycle concept has had for fungal disease prediction.

  3. 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...

  4. Bacterial quorum sensing: signals, circuits, and implications for biofilms and disease.

    PubMed

    Jayaraman, Arul; Wood, Thomas K

    2008-01-01

    Communication between bacteria, belonging to the same species or to different species, is mediated through different chemical signals that are synthesized and secreted by bacteria. These signals can either be cell-density related (autoinducers) or be produced by bacteria at different stages of growth, and they allow bacteria to monitor their environment and alter gene expression to derive a competitive advantage. The properties of these signals and the response elicited by them are important in ensuring bacterial survival and propagation in natural environments (e.g., human oral cavity) where hundreds of bacterial species coexist. First, the interaction between a signal and its receptor is very specific, which underlies intraspecies communication and quorum sensing. Second, when multiple signals are synthesized by the same bacterium, the signaling circuits utilized by the different signals are coordinately regulated with distinct overall circuit architecture so as to maximize the overall response. Third, the recognition of a universal communication signal synthesized by different bacterial species (interspecies communication), as well that of signals produced by eukaryotic cells (interkingdom communication), is also integral to the formation of multispecies biofilm communities that are important in infection and disease. The focus of this review is on the principles underlying signal-mediated bacterial communication, with specific emphasis on the potential for using them in two applications-development of synthetic biology modules and circuits, and the control of biofilm formation and infection.

  5. Arabidopsis EF-Tu receptor enhances bacterial disease resistance in transgenic wheat.

    PubMed

    Schoonbeek, Henk-Jan; Wang, Hsi-Hua; Stefanato, Francesca L; Craze, Melanie; Bowden, Sarah; Wallington, Emma; Zipfel, Cyril; Ridout, Christopher J

    2015-04-01

    Perception of pathogen (or microbe)-associated molecular patterns (PAMPs/MAMPs) by pattern recognition receptors (PRRs) is a key component of plant innate immunity. The Arabidopsis PRR EF-Tu receptor (EFR) recognizes the bacterial PAMP elongation factor Tu (EF-Tu) and its derived peptide elf18. Previous work revealed that transgenic expression of AtEFR in Solanaceae confers elf18 responsiveness and broad-spectrum bacterial disease resistance. In this study, we developed a set of bioassays to study the activation of PAMP-triggered immunity (PTI) in wheat. We generated transgenic wheat (Triticum aestivum) plants expressing AtEFR driven by the constitutive rice actin promoter and tested their response to elf18. We show that transgenic expression of AtEFR in wheat confers recognition of elf18, as measured by the induction of immune marker genes and callose deposition. When challenged with the cereal bacterial pathogen Pseudomonas syringae pv. oryzae, transgenic EFR wheat lines had reduced lesion size and bacterial multiplication. These results demonstrate that AtEFR can be transferred successfully from dicot to monocot species, further revealing that immune signalling pathways are conserved across these distant phyla. As novel PRRs are identified, their transfer between plant families represents a useful strategy for enhancing resistance to pathogens in crops.

  6. Heat treatment induced bacterial changes in irrigation water and their implications for plant disease management.

    PubMed

    Hao, W; Hong, C X

    2014-05-01

    A new heat treatment for recycled irrigation water using 48 °C for 24 h to inactivate Phytophthora and bacterial plant pathogens is estimated to reduce fuel cost and environmental footprint by more than 50 % compared to current protocol (95 °C for 30 s). The objective of this study was to determine the impact of this new heat treatment temperature regime on bacterial community structure in water and its practical implications. Bacterial communities in irrigation water were analyzed before and after heat treatment using both culture-dependent and -independent strategies based on the 16S ribosomal DNA. A significant shift was observed in the bacterial community after heat treatment. Most importantly, bacteria with biological control potential--Bacillus and Paenibacillus, and Pseudomonas species became more abundant at both 48 and 42 °C. These findings imply that the new heat treatment procedure not only controls existing plant pathogens but also may make the heat-treated irrigation water a more antagonistic environment against plant pathogens, promoting sustainable disease management.

  7. 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

  8. [Per os given bacteriophages changes the clinical course of diseases caused by bacterial agents in children].

    PubMed

    Pagava, K I; Metskhvarishvili, G J; Korineli, I A; Gongadze, T B

    2012-10-01

    The aim of the study was to reveal the possible effect of perorally given bacteriophages on the clinical course of diseases caused by infectious agents in children. The complex therapy with inclusion of bacteriophages was performed in 85 children aged from 1 week to 15 years, 36 girls, 47 boys with following diagnoses: sepsis, bacterial diarrhea, urinary tract infections, bacterial infections of upper respiratory ways, bacterial pneumonia. For every case an appropriate analoguous control was matched. Thus this open clinical trial was carried out according to the Case Control Study design. Clinical and paraclinical markers specific for different diseases and integrated index of the gravitidy of condition. defined by the method of multicriterial analyzis with usage of Fuzzy logic approaches were revealed in dynamics. It was established that by peroral treatment with commercial bacteriophages the positive trends of investigated parameters had place. The improvement of the integrated index of gravitidy was most pronounced. We suppose that obtaining of more convincing evidences of the clinical value of bacteriophagetherapy the further studies in the more number of patients with the usage of the generally accepted double blind method should be conducted.

  9. Clinical implications of oral candidiasis: host tissue damage and disseminated bacterial disease.

    PubMed

    Kong, Eric F; Kucharíková, Sona; Van Dijck, Patrick; Peters, Brian M; Shirtliff, Mark E; Jabra-Rizk, Mary Ann

    2015-02-01

    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.

  10. 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

  11. 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.

  12. 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.

  13. Genetic engineering for increasing fungal and bacterial disease resistance in crop plants.

    PubMed

    Wally, Owen; Punja, Zamir K

    2010-01-01

    We review the current and future potential of genetic engineering strategies used to make fungal and bacterial pathogen-resistant GM crops, illustrating different examples of the technologies and the potential benefits and short-falls of the strategies. There are well- established procedures for the production of transgenic plants with resistance towards these pathogens and considerable progress has been made using a range of new methodologies. There are no current commercially available transgenic plant species with increased resistance towards fungal and bacterial pathogens; only plants with increased resistance towards viruses are available. With an improved understanding of plant signaling pathways in response to a range of other pathogens, such as fungi, additional candidate genes for achieving resistance are being investigated. The potential for engineering plants for resistance against individual devastating diseases or for plants with resistance towards multiple pathogens is discussed in detail.

  14. Traditional and Molecular Techniques for the Study of Emerging Bacterial Diseases: One Laboratory’s Perspective

    PubMed Central

    Houpikian, Pierre

    2002-01-01

    Identification of emerging bacterial pathogens generally results from a chain of events involving microscopy, serology, molecular tools, and culture. Because of the spectacular molecular techniques developed in the last decades, some authors think that these techniques will shortly supplant culture. The key steps that led to the discovery of emerging bacteria have been reviewed to determine the real contribution of each technique. Historically, microscopy has played a major role. Serology provided indirect evidence for causality. Isolation and culture were crucial, as all emerging bacteria have been grown on artificial media or cell lines or at least propagated in animals. With the use of broad-range polymerase chain reaction, some bacteria have been identified or detected in new clinical syndromes. Culture has irreplaceable advantages for studying emerging bacterial diseases, as it allows antigenic studies, antibiotic susceptibility testing, experimental models, and genetic studies to be carried out, and remains the ultimate goal of pathogen identification. PMID:11897062

  15. 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

  16. 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

  17. 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.

  18. Bacterial diversity and White Plague Disease-associated community changes in the Caribbean coral Montastraea faveolata.

    PubMed

    Sunagawa, Shinichi; DeSantis, Todd Z; Piceno, Yvette M; Brodie, Eoin L; DeSalvo, Michael K; Voolstra, Christian R; Weil, Ernesto; Andersen, Gary L; Medina, Mónica

    2009-05-01

    Increasing evidence confirms the crucial role bacteria and archaea play within the coral holobiont, that is, the coral host and its associated microbial community. The bacterial component constitutes a community of high diversity, which appears to change in structure in response to disease events. In this study, we highlight the limitation of 16S rRNA gene (16S rDNA) clone library sequencing as the sole method to comprehensively describe coral-associated communities. This limitation was addressed by combining a high-density 16S rRNA gene microarray with, clone library sequencing as a novel approach to study bacterial communities in healthy versus diseased corals. We determined an increase in diversity as well as a significant shift in community structure in Montastraea faveolata colonies displaying phenotypic signs of White Plague Disease type II (WPD-II). An accumulation of species that belong to families that include known coral pathogens (Alteromonadaceae, Vibrionaceae), bacteria previously isolated from diseased, stressed or injured marine invertebrates (for example, Rhodobacteraceae), and other species (for example, Campylobacteraceae) was observed. Some of these species were also present in healthy tissue samples, but the putative primary pathogen, Aurantimonas corallicida, was not detected in any sample by either method. Although an ecological succession of bacteria during disease progression after causation by a primary agent represents a possible explanation for our observations, we also discuss the possibility that a disease of yet to be determined etiology may have affected M. faveolata colonies and resulted in (or be a result of) an increase in opportunistic pathogens.

  19. Culturable bacterial microbiota of the stomach of Helicobacter pylori positive and negative gastric disease patients.

    PubMed

    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.

  20. 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.

  1. A program against bacterial bioterrorism: improved patient management and acquisition of new knowledge on infectious diseases.

    PubMed

    Kemp, Michael; Dargis, Rimtas; Andresen, Keld; Christensen, Jens Jørgen E

    2012-06-01

    In 2002 it was decided to establish laboratory facilities in Denmark for diagnosing agents associated with bioterrorism in order to make an immediate appropriate response to the release of such agents possible. Molecular assays for detection of specific agents and molecular and proteomic techniques for identification of bacteria were introduced as part of the program. All assays and techniques were made accessible for use in diagnosing patients, even when an intentional release was not suspected. Medical expertise on different diseases was established at the department as an integrated part of the program. The analyses included PCR assays for specific bacteria, identification of isolated bacteria by DNA sequencing, detection and identification of bacteria in clinical sample material by universal bacterial PCR and DNA sequencing, and identification of bacteria by mass spectrometry. The established analyses formed a basis on which a series of further developments was built. In addition to reducing the time for obtaining diagnoses and improving the accuracy of diagnosis of individual infected patients, the analyses provided new knowledge on the frequency and distribution of some bacterial infections, including Q fever, tularemia, trench fever, brucellosis, and melioidosis. The implementation of an antibioterrorism program in a clinical diagnostic setting improved the diagnostic possibilities for patients in Denmark and provided new epidemiologic information. It also introduced a number of diagnostic assays for bacterial infections not associated with bioterrorism that are difficult to culture or identify.

  2. 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

    2016-04-05

    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.

  3. 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.

  4. 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

  5. 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).

  6. 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

  7. Probability of foliar injury for Acer sp. based on foliar fluoride concentrations.

    PubMed

    McDonough, Andrew M; Dixon, Murray J; Terry, Debbie T; Todd, Aaron K; Luciani, Michael A; Williamson, Michele L; Roszak, Danuta S; Farias, Kim A

    2016-12-01

    Fluoride is considered one of the most phytotoxic elements to plants, and indicative fluoride injury has been associated over a wide range of foliar fluoride concentrations. The aim of this study was to determine the probability of indicative foliar fluoride injury based on Acer sp. foliar fluoride concentrations using a logistic regression model. Foliage from Acer nedundo, Acer saccharinum, Acer saccharum and Acer platanoides was collected along a distance gradient from three separate brick manufacturing facilities in southern Ontario as part of a long-term monitoring programme between 1995 and 2014. Hydrogen fluoride is the major emission source associated with the manufacturing facilities resulting with highly elevated foliar fluoride close to the facilities and decreasing with distance. Consistent with other studies, indicative fluoride injury was observed over a wide range of foliar concentrations (9.9-480.0 μg F(-) g(-1)). The logistic regression model was statistically significant for the Acer sp. group, A. negundo and A. saccharinum; consequently, A. negundo being the most sensitive species among the group. In addition, A. saccharum and A. platanoides were not statistically significant within the model. We are unaware of published foliar fluoride values for Acer sp. within Canada, and this research provides policy maker and scientist with probabilities of indicative foliar injury for common urban Acer sp. trees that can help guide decisions about emissions controls. Further research should focus on mechanisms driving indicative fluoride injury over wide ranging foliar fluoride concentrations and help determine foliar fluoride thresholds for damage.

  8. 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

  9. 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.

  10. Protein Mis-Termination Initiates Genetic Diseases, Cancers, and Restricts Bacterial Genome Expansion.

    PubMed

    Wong, Tit-Yee; Schwartzbach, Steve D

    2015-01-01

    Protein termination is an important cellular process. Protein termination relies on the stop-codons in the mRNA interacting properly with the releasing factors on the ribosome. One third of inherited diseases, including cancers, are associated with the mutation of the stop-codons. Many pathogens and viruses are able to manipulate their stop-codons to express their virulence. The influence of stop-codons is not limited to the primary reading frame of the genes. Stop-codons in the second and third reading frames are referred as premature stop signals (PSC). Stop-codons and PSCs together are collectively referred as stop-signals. The ratios of the stop-signals (referred as translation stop-signals ratio or TSSR) of genetically related bacteria, despite their great differences in gene contents, are much alike. This nearly identical Genomic-TSSR value of genetically related bacteria may suggest that bacterial genome expansion is limited by their unique stop-signals bias. We review the protein termination process and the different types of stop-codon mutation in plants, animals, microbes, and viruses, with special emphasis on the role of PSCs in directing bacterial evolution in their natural environments. Knowing the limit of genomic boundary could facilitate the formulation of new strategies in controlling the spread of diseases and combat antibiotic-resistant bacteria.

  11. Persistent and Recurrent Bacterial Bronchitis—A Paradigm Shift in Our Understanding of Chronic Respiratory Disease

    PubMed Central

    Ishak, Alya; Everard, Mark L.

    2017-01-01

    The recent recognition that the conducting airways are not “sterile” and that they have their own dynamic microbiome, together with the rapid advances in our understanding of microbial biofilms and their roles in the causation of respiratory diseases (such as chronic bronchitis, sinusitis, and chronic otitis media), permit us to update the “vicious circle” hypothesis of the causation of bronchiectasis. This proposes that chronic inflammation driven by persistent bacterial bronchitis (PBB) causes damage to both the epithelium, resulting in impaired mucociliary clearance, and to the airway wall, which eventually manifests as bronchiectasis. The link between a “chronic bronchitis” and a persistence of bacterial pathogens, such as non-typable Haemophilus influenzae, was first made more than 100 years ago, and its probable role in the causation of bronchiectasis was proposed soon afterward. The recognition that the “usual suspects” are adept at forming biofilms and hence are able to persist and dominate the normal dynamically changing “healthy microbiome” of the conducting airways provides an explanation for the chronic colonization of the bronchi and for the associated chronic neutrophil-dominated inflammation characteristic of a PBB. Understanding the complex interaction between the host and the microbial communities of the conducting airways in health and disease will be a key component in optimizing pulmonary health in the future. PMID:28261574

  12. Chron's disease, rare association with selective IgA immunodeficiency, and development of life-threatening bacterial infections.

    PubMed

    Manfredi, Roberto; Coronado, Olga V; Marinacci, Ginevra; Righi, Mauro; Calza, Leonardo

    2004-01-01

    Life-threatening necrotizing fasciitis and relapsing Lemierre syndrome associated with Fusobacterium necrophorum septicaemia occurred in young adults with a moderate Chron's disease and a missed profound IgA deficiency. This unexpected association of a chronic bowel inflammatory syndrome with prominent IgA abnormalities and severe bacterial infection deserves careful attention by physicians faced with young patients with Chron's disease.

  13. 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.

  14. 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

  15. Methods to determine intestinal permeability and bacterial translocation during liver disease

    PubMed Central

    Wang, Lirui; Llorente, Cristina; Hartmann, Phillipp; Yang, An-Ming; Chen, Peng; Schnabl, Bernd

    2015-01-01

    Liver disease is often times associated with increased intestinal permeability. A disruption of the gut barrier allows microbial products and viable bacteria to translocate from the intestinal lumen to extraintestinal organs. The majority of the venous blood from the intestinal tract is drained into the portal circulation, which is part of the dual hepatic blood supply. The liver is therefore the first organ in the body to encounter not only absorbed nutrients, but also gut-derived bacteria and pathogen associated molecular patterns (PAMPs). Chronic exposure to increased levels of PAMPs has been linked to disease progression during early stages and to infectious complications during late stages of liver disease (cirrhosis). It is therefore important to assess and monitor gut barrier dysfunction during hepatic disease. We review methods to assess intestinal barrier disruption and discuss advantages and disadvantages. We will in particular focus on methods that we have used to measure increased intestinal permeability and bacterial translocation during experimental liver disease models. PMID:25595554

  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. A nonluminescent and highly virulent Vibrio harveyi strain is associated with "bacterial white tail disease" of Litopenaeus vannamei shrimp.

    PubMed

    Zhou, Junfang; Fang, Wenhong; Yang, Xianle; Zhou, Shuai; Hu, Linlin; Li, Xincang; Qi, Xinyong; Su, Hang; Xie, Layue

    2012-01-01

    Recurrent outbreaks of a disease in pond-cultured juvenile and subadult Litopenaeus vannamei shrimp in several districts in China remain an important problem in recent years. The disease was characterized by "white tail" and generally accompanied by mass mortalities. Based on data from the microscopical analyses, PCR detection and 16S rRNA sequencing, a new Vibrio harveyi strain (designated as strain HLB0905) was identified as the etiologic pathogen. The bacterial isolation and challenge tests demonstrated that the HLB0905 strain was nonluminescent but highly virulent. It could cause mass mortality in affected shrimp during a short time period with a low dose of infection. Meanwhile, the histopathological and electron microscopical analysis both showed that the HLB0905 strain could cause severe fiber cell damages and striated muscle necrosis by accumulating in the tail muscle of L. vannamei shrimp, which led the affected shrimp to exhibit white or opaque lesions in the tail. The typical sign was closely similar to that caused by infectious myonecrosis (IMN), white tail disease (WTD) or penaeid white tail disease (PWTD). To differentiate from such diseases as with a sign of "white tail" but of non-bacterial origin, the present disease was named as "bacterial white tail disease (BWTD)". Present study revealed that, just like IMN and WTD, BWTD could also cause mass mortalities in pond-cultured shrimp. These results suggested that some bacterial strains are changing themselves from secondary to primary pathogens by enhancing their virulence in current shrimp aquaculture system.

  18. 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.

  19. [Colonization and disease control and fruit preservation functions of endophytic bacterial strains in lychee].

    PubMed

    Cai, Xue-qing; Chen, Wei; Lin, Na; Lin, Tong; Hu, Fang-ping

    2011-08-01

    By spraying the GFP-marked endophytic bacterial strains BS-2-gfp and TB2-gfp, this paper studied their colonization in lychee organs and the functions of the strains in disease control and fruit preservation. The BS-2-gfp and TB2-gfp could colonize and propagate in lychee leaves, flowers, un-matured fruits, and matured fruits, and transfer from the flowers to un-matured fruits. The colonization of BS-2-gfp and TB2-gfp in lychee leaves varied with season and growth stage, being larger in quantity and longer in duration in spring than in autumn. The colonization quantity and duration of the strains also differed in other organs. Both the BS-2-gfp and the TB2-gfp could be isolated and recovered from lychee leaves after 37 d inoculation, the BS-2-gfp could not be isolated from the flowers after inoculation for 10 d, and the BS-2-gfp and TB2-gfp had the largest colonization quantity in matured fruits. The colonization quantity of TB2-gfp in lychee pericarp reached to the maximum (1.90 x 10(6) CFU x g(-1) FM) when the disease index of litchi downy blight had a sharp increase, and, compared with BS-2-gfp, the TB2-gfp had better fruit preservation efficiency, and its colonization quantity in lychee pericarp was also higher. It was suggested that there was a positive correlation between the colonization quantity of test bacterial strains in lychee pericarp and the disease control and fruit preservation effect.

  20. Characterization of rhizosphere fungi that mediate resistance in tomato against bacterial wilt disease.

    PubMed

    Jogaiah, Sudisha; Abdelrahman, Mostafa; Tran, Lam-Son Phan; Shin-ichi, Ito

    2013-09-01

    Plant immunization for resistance against a wide variety of phytopathogens is an effective strategy for plant disease management. Seventy-nine plant growth-promoting fungi (PGPFs) were isolated from rhizosphere soil of India. Among them, nine revealed saprophytic ability, root colonization, phosphate solubilization, IAA production, and plant growth promotion. Seed priming with four PGPFs exhibited early seedling emergence and enhanced vigour of a tomato cultivar susceptible to the bacterial wilt pathogen compared to untreated controls. Under greenhouse conditions, TriH_JSB27 and PenC_JSB41 treatments remarkably enhanced the vegetative and reproductive growth parameters. Maximum NPK uptake was noticed in TriH_JSB27-treated plants. A significant disease reduction of 57.3% against Ralstonia solanacearum was observed in tomato plants pretreated with TriH_JSB27. Furthermore, induction of defence-related enzymes and genes was observed in plants pretreated with PGPFs or inoculated with pathogen. The maximum phenylalanine ammonia lyase (PAL) activity (111U) was observed at 24h in seedlings treated with TriH_JSB27 and this activity was slightly reduced (99U) after pathogen inoculation. Activities of peroxidase (POX, 54U) and β-1,3-glucanase (GLU, 15U) were significantly higher in control plants inoculated with pathogen after 24h and remained constant at all time points. A similar trend in gene induction for PAL was evident in PGPFs-treated tomato seedlings with or without pathogen inoculation, whereas POX and GLU were upregulated in control plus pathogen-inoculated tomato seedlings. These results determine that the susceptible tomato cultivar is triggered after perception of potent PGPFs to synthesize PAL, POX, and GLU, which activate defence resistance against bacterial wilt disease, thereby contributing to plant health improvement.

  1. Nutrition and Helicobacter pylori: Host Diet and Nutritional Immunity Influence Bacterial Virulence and Disease Outcome

    PubMed Central

    2016-01-01

    Helicobacter pylori colonizes the stomachs of greater than 50% of the world's human population making it arguably one of the most successful bacterial pathogens. Chronic H. pylori colonization results in gastritis in nearly all patients; however in a subset of people, persistent infection with H. pylori is associated with an increased risk for more severe disease outcomes including B-cell lymphoma of mucosal-associated lymphoid tissue (MALT lymphoma) and invasive adenocarcinoma. Research aimed at elucidating determinants that mediate disease progression has revealed genetic differences in both humans and H. pylori which increase the risk for developing gastric cancer. Furthermore, host diet and nutrition status have been shown to influence H. pylori-associated disease outcomes. In this review we will discuss how H. pylori is able to create a replicative niche within the hostile host environment by subverting and modifying the host-generated immune response as well as successfully competing for limited nutrients such as transition metals by deploying an arsenal of metal acquisition proteins and virulence factors. Lastly, we will discuss how micronutrient availability or alterations in the gastric microbiome may exacerbate negative disease outcomes associated with H. pylori colonization. PMID:27688750

  2. Nutrition and Helicobacter pylori: Host Diet and Nutritional Immunity Influence Bacterial Virulence and Disease Outcome.

    PubMed

    Haley, Kathryn P; Gaddy, Jennifer A

    2016-01-01

    Helicobacter pylori colonizes the stomachs of greater than 50% of the world's human population making it arguably one of the most successful bacterial pathogens. Chronic H. pylori colonization results in gastritis in nearly all patients; however in a subset of people, persistent infection with H. pylori is associated with an increased risk for more severe disease outcomes including B-cell lymphoma of mucosal-associated lymphoid tissue (MALT lymphoma) and invasive adenocarcinoma. Research aimed at elucidating determinants that mediate disease progression has revealed genetic differences in both humans and H. pylori which increase the risk for developing gastric cancer. Furthermore, host diet and nutrition status have been shown to influence H. pylori-associated disease outcomes. In this review we will discuss how H. pylori is able to create a replicative niche within the hostile host environment by subverting and modifying the host-generated immune response as well as successfully competing for limited nutrients such as transition metals by deploying an arsenal of metal acquisition proteins and virulence factors. Lastly, we will discuss how micronutrient availability or alterations in the gastric microbiome may exacerbate negative disease outcomes associated with H. pylori colonization.

  3. Transgenic resistance confers effective field level control of bacterial spot disease in tomato.

    PubMed

    Horvath, Diana M; Stall, Robert E; Jones, Jeffrey B; Pauly, Michael H; Vallad, Gary E; Dahlbeck, Doug; Staskawicz, Brian J; Scott, John W

    2012-01-01

    We investigated whether lines of transgenic tomato (Solanum lycopersicum) expressing the Bs2 resistance gene from pepper, a close relative of tomato, demonstrate improved resistance to bacterial spot disease caused by Xanthomonas species in replicated multi-year field trials under commercial type growing conditions. We report that the presence of the Bs2 gene in the highly susceptible VF 36 background reduced disease to extremely low levels, and VF 36-Bs2 plants displayed the lowest disease severity amongst all tomato varieties tested, including commercial and breeding lines with host resistance. Yields of marketable fruit from transgenic lines were typically 2.5 times that of the non-transformed parent line, but varied between 1.5 and 11.5 fold depending on weather conditions and disease pressure. Trials were conducted without application of any copper-based bactericides, presently in wide use despite negative impacts on the environment. This is the first demonstration of effective field resistance in a transgenic genotype based on a plant R gene and provides an opportunity for control of a devastating pathogen while eliminating ineffective copper pesticides.

  4. 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.

  5. 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

  6. Transgenic Resistance Confers Effective Field Level Control of Bacterial Spot Disease in Tomato

    PubMed Central

    Horvath, Diana M.; Stall, Robert E.; Jones, Jeffrey B.; Pauly, Michael H.; Vallad, Gary E.; Dahlbeck, Doug; Staskawicz, Brian J.; Scott, John W.

    2012-01-01

    We investigated whether lines of transgenic tomato (Solanum lycopersicum) expressing the Bs2 resistance gene from pepper, a close relative of tomato, demonstrate improved resistance to bacterial spot disease caused by Xanthomonas species in replicated multi-year field trials under commercial type growing conditions. We report that the presence of the Bs2 gene in the highly susceptible VF 36 background reduced disease to extremely low levels, and VF 36-Bs2 plants displayed the lowest disease severity amongst all tomato varieties tested, including commercial and breeding lines with host resistance. Yields of marketable fruit from transgenic lines were typically 2.5 times that of the non-transformed parent line, but varied between 1.5 and 11.5 fold depending on weather conditions and disease pressure. Trials were conducted without application of any copper-based bactericides, presently in wide use despite negative impacts on the environment. This is the first demonstration of effective field resistance in a transgenic genotype based on a plant R gene and provides an opportunity for control of a devastating pathogen while eliminating ineffective copper pesticides. PMID:22870280

  7. Association between Respiratory Disease and Bacterial and Viral Infections in British Racehorses

    PubMed Central

    Wood, J. L. N.; Newton, J. R.; Chanter, N.; Mumford, J. A.

    2005-01-01

    Respiratory disease is important in horses, particularly in young Thoroughbred racehorses, and inflammation that is detected in the trachea and bronchi (termed inflammatory airway disease [IAD]) is more significant in this population in terms of impact and frequency than other presentations of respiratory disease. IAD, which is characterized by neutrophilic inflammation, mild clinical signs, and accumulation of mucus in the trachea, may be multifactorial, possibly involving infections and environmental and immunological factors, and its etiology remains unclear. This 3-year longitudinal study of young Thoroughbred racehorses was undertaken to characterize the associations of IAD and nasal discharge with viral and bacterial infections. IAD was statistically associated with tracheal infection with Streptococcus pneumoniae (capsule type 3), Streptococcus zooepidemicus, Actinobacillus spp., and Mycoplasma equirhinis and equine herpesvirus 1 and 4 infections, after adjustment for variation between training yards, seasons, and age groups. The association with S. pneumoniae and S. zooepidemicus was independent of prior viral infection and, critically, was dependent on the numbers of organisms isolated. S. pneumoniae was significant only in horses that were 2 years old or younger. The prevalence and incidence of IAD, S. zooepidemicus, and S. pneumoniae decreased in parallel with age, consistent with increased disease resistance, perhaps by the acquisition of immunity. The study provided evidence for S. zooepidemicus and S. pneumoniae playing an important etiological role in the pathogenesis of IAD in young horses. PMID:15634959

  8. 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

  9. Effect of a rock dust amendment on disease severity of tomato bacterial wilt.

    PubMed

    Li, Jian-Gang; Dong, Yuan-Hua

    2013-01-01

    Nutrients are important for growth and development of plants and microbes, and they are also important factors in plant disease control. The objective of this study was to evaluate the effect of a rock dust used as a fertilizer in maintaining health of soil and tomato plants under greenhouse conditions. Four treatments-including M (commercial organic fertilizer), A (rock dust soil amendment), M + A (commercial organic fertilizer + rock dust soil amendment) and CK (blank control)--were examined for their effect on soil properties, soil enzymatic activity, plant growth and control efficacy against tomato bacterial wilt. Treatments A and M + A were significantly better than other treatments in changing soil pH, increasing it from acidic (pH 5.13) to nearly neutral (pH 6.81 and 6.70, respectively). Enzymatic activities in soil were notably influenced by the different treatments--particularly treatment M + A, which increased the activities of alkaline phosphatase, urease, catalase and sucrase to a greater extent in soil. There was no significant difference (P < 0.05) in the effects of treatments A and M + A on tomato plant height, stem diameter and biomass. The effect of the four treatments on the chlorophyll content and photosynthetic rate (in decreasing order) were M + A, A, M and CK. The replicate greenhouse experiments showed that the control efficacies of treatments M + A, A, and M against bacterial wilt were respectively 89.99, 81.11 and 8.89 % in first experiment and with the efficacies of 84.55, 74.36, and 13.49 % in the replicate; indicating that rock dust played a key role in the plant-soil interaction. The raised soil pH and Ca content were the key factors for the rock dust amendment controlling bacterial wilt under greenhouse conditions.

  10. 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

  11. May bacterial or pancreatic proteases play a critical role in inflammatory bowel disease?

    PubMed

    Qin, Xiaofa

    2014-09-21

    In a recent review paper, Carroll and Maharshak discussed a critical role of enteric bacterial proteases in the pathogenesis of inflammatory bowel disease (IBD). I take a great interest in this paper as I also suspected proteases, not from the bacteria, but those originated from the pancreas that failed to be inactivated in the lower gut due to a reduction in gut bacteria, may have played a critical role in the pathogenesis of IBD, which was first published more than a decade ago and discussed again in more detail in a recent paper published in this journal. Antibiotics may result in a big reduction in gut bacteria and bacterial proteases, but multiple studies demonstrated dramatic increased of pancreatic proteases like trypsin and chymotrypsin in the feces of animals or patients treated with antibiotics. Multiple large-scale studies also demonstrated use of antibiotics caused an increase but not decrease in the risk of developing IBD, suggesting impaired inactivation and degradation of pancreatic proteases may have played a more critical role in the pathogenesis of IBD.

  12. Molecular mimicry of host structures by bacterial lipopolysaccharides and its contribution to disease.

    PubMed

    Moran, A P; Prendergast, M M; Appelmelk, B J

    1996-12-01

    The core oligosaccharides of low-molecular-weight lipopolysaccharide (LPS), also termed lipooligosaccharide (LOS), of pathogenic Neisseria spp. mimic the carbohydrate moieties of glycosphingolipids present on human cells. Such mimicry may serve to camouflage the bacterial surface from the host. The LOS component is antigenically and/or chemically identical to lactoneoseries glycosphingolipids and can become sialylated in Neisseria gonorrhoeae when the bacterium is grown in the presence of cytidine 5'-monophospho-N-acetylneuraminic acid, the nucleotide sugar of sialic acid. Strains of Neisseria meningitidis and Haemophilus influenzae also express similarly sialylated LPS. Sialylation of the LOS influences susceptibility to bactericidal antibody, may decrease or prevent phagocytosis, cause down-regulation of complement activation, and decrease adherence to neutrophils and the subsequent oxidative burst response. The core oligosaccharides of LPS of Campylobacter jejuni serotypes which are associated with the development of the neurological disorder, Guillain-Barré syndrome (GBS), exhibit mimicry of gangliosides. Cross-reactive antibodies between C. jejuni LPS and gangliosides are considered to play an important role in GBS pathogenesis. In contrast, the O-chain of a number of Helicobacter pylori strains exhibit mimicry of Lewis(x) and Lewis(y) blood group antigens. The role of this mimicry remains to be investigated, but may play a role in bacterial camouflage, the induction of autoimmunity and immune suppression in H. pylori-associated disease.

  13. 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.

  14. 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

    2016-05-11

    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.

  15. 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

  16. Development of immersion vaccine for bacterial cold-water disease in ayu Plecoglossus altivelis.

    PubMed

    Nakayama, Hitoshi; Mori, Mariko; Takita, Teisuke; Yasukawa, Kiyoshi; Tanaka, Keisuke; Hattori, Shunji; Aikawa, Hideaki; Hasegawa, Osamu; Okamura, Takashi; Takegami, Kentarou; Motokawa, Shogo; Kuwahara, Masakazu; Amano, Kenichi

    2017-03-01

    Flavobacterium psychrophilum (F. psychrophilum) is the causative agent of bacterial cold-water disease (BCWD) that occurs in ayu Plecoglossus altivelis. Formalin-killed cell of F. psychrophilum has long been studied as an immersion vaccine for BCWD. In this study, we explored the possibility of F. psychrophilum collagenase (fpcol) for use as the immersion vaccine. BCWD convalescent ayu sera contained specific IgM antibodies against somatic F. psychrophilum and fpcol, meaning that fpcol is a promising antigen for the vaccine development. The recombinant fpcol was successfully expressed in Escherichia coli and Brevibacillus chosinensis (B. chosinensis). The culture supernatant of the B. chosinensis was used as an immersion vaccine solution. The vaccinated ayu were then challenged by soaking into F. psychrophilum culture. In two experimental groups, the relative percentages of survivals were 63 and 38%, respectively, suggesting that fpcol is promising as the immersion vaccine for ayu-BCWD.

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

    USGS Publications Warehouse

    Starliper, Clifford E.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

    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.

  19. Gut bacterial profile in patients newly diagnosed with treatment-naïve Crohn’s disease

    PubMed Central

    Ricanek, Petr; Lothe, Sheba M; Frye, Stephan A; Rydning, Andreas; Vatn, Morten H; Tønjum, Tone

    2012-01-01

    Objectives: The aim of this study was to define the composition of the gut bacterial flora in Norwegian patients with early stage Crohn’s disease (CD). Methods: By using a nonselective metagenomics approach, the general bacterial composition in mucosal biopsies from the ileum and the colon of five subjects, four patients with different phenotypes of CD, and one noninflammatory bowel disease control, was characterized. After partial 16S ribosomal RNA (rRNA) gene sequencing, BLAST homology searches for species identification and phylogenetic analysis were performed. Results: An overall biodiversity of 106 different bacterial operational taxonomic units (OTUs) was detected in the cloned libraries. Nearly all OTUs belonged to the phylae Bacteroidetes (42% in CD, 71% in the control) or Firmicutes (42% in CD, 28% in the control), except for some OTUs that belonged to the phylum Proteobacteria (15% in CD, 0% in the control) and a few OTUs that could not be assigned to a phylum (2% in CD, 1% in the control). Conclusion: Based on the high incidence of inflammatory bowel disease (IBD) in Norway, this pilot study represents a relevant determination of the gut microbiota in Norwegian patients compared to previous findings in other countries. The bacterial profile of Norwegian CD patients was found to be similar to that of CD patients in other countries. The findings do not support a particular bacterial composition as a predominant causative factor for the high incidence of IBD that exists in some countries. PMID:23049264

  20. Identification of Genes in Thuja plicata Foliar Terpenoid Defenses1[C][W][OA

    PubMed Central

    Foster, Adam J.; Hall, Dawn E.; Mortimer, Leanne; Abercromby, Shelley; Gries, Regine; Gries, Gerhard; Bohlmann, Jörg; Russell, John; Mattsson, Jim

    2013-01-01

    Thuja plicata (western redcedar) is a long-lived conifer species whose foliage is rarely affected by disease or insect pests, but can be severely damaged by ungulate browsing. Deterrence to browsing correlates with high foliar levels of terpenoids, in particular the monoterpenoid α-thujone. Here, we set out to identify genes whose products may be involved in the production of α-thujone and other terpenoids in this species. First, we generated a foliar transcriptome database from which to draw candidate genes. Second, we mapped the storage of thujones and other terpenoids to foliar glands. Third, we used global expression profiling to identify more than 600 genes that are expressed at high levels in foliage with glands, but can either not be detected or are expressed at low levels in a natural variant lacking foliar glands. Fourth, we used in situ RNA hybridization to map the expression of a putative monoterpene synthase to the epithelium of glands and used enzyme assays with recombinant protein of the same gene to show that it produces sabinene, the monoterpene precursor of α-thujone. Finally, we identified candidate genes with predicted enzymatic functions for the conversion of sabinene to α-thujone. Taken together, this approach generated both general resources and detailed functional characterization in the identification of genes of foliar terpenoid biosynthesis in T. plicata. PMID:23388118

  1. 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

  2. Disordered macrophage cytokine secretion underlies impaired acute inflammation and bacterial clearance in Crohn's disease.

    PubMed

    Smith, Andrew M; Rahman, Farooq Z; Hayee, Bu'Hussain; Graham, Simon J; Marks, Daniel J B; Sewell, Gavin W; Palmer, Christine D; Wilde, Jonathan; Foxwell, Brian M J; Gloger, Israel S; Sweeting, Trevor; Marsh, Mark; Walker, Ann P; Bloom, Stuart L; Segal, Anthony W

    2009-08-31

    The cause of Crohn's disease (CD) remains poorly understood. Counterintuitively, these patients possess an impaired acute inflammatory response, which could result in delayed clearance of bacteria penetrating the lining of the bowel and predispose to granuloma formation and chronicity. We tested this hypothesis in human subjects by monitoring responses to killed Escherichia coli injected subcutaneously into the forearm. Accumulation of (111)In-labeled neutrophils at these sites and clearance of (32)P-labeled bacteria from them were markedly impaired in CD. Locally increased blood flow and bacterial clearance were dependent on the numbers of bacteria injected. Secretion of proinflammatory cytokines by CD macrophages was grossly impaired in response to E. coli or specific Toll-like receptor agonists. Despite normal levels and stability of cytokine messenger RNA, intracellular levels of tumor necrosis factor (TNF) were abnormally low in CD macrophages. Coupled with reduced secretion, these findings indicate accelerated intracellular breakdown. Differential transcription profiles identified disease-specific genes, notably including those encoding proteins involved in vesicle trafficking. Intracellular destruction of TNF was decreased by inhibitors of lysosomal function. Together, our findings suggest that in CD macrophages, an abnormal proportion of cytokines are routed to lysosomes and degraded rather than being released through the normal secretory pathway.

  3. Disordered macrophage cytokine secretion underlies impaired acute inflammation and bacterial clearance in Crohn's disease

    PubMed Central

    Smith, Andrew M.; Rahman, Farooq Z.; Hayee, Bu'Hussain; Graham, Simon J.; Marks, Daniel J.B.; Sewell, Gavin W.; Palmer, Christine D.; Wilde, Jonathan; Foxwell, Brian M.J.; Gloger, Israel S.; Sweeting, Trevor; Marsh, Mark; Walker, Ann P.; Bloom, Stuart L.

    2009-01-01

    The cause of Crohn's disease (CD) remains poorly understood. Counterintuitively, these patients possess an impaired acute inflammatory response, which could result in delayed clearance of bacteria penetrating the lining of the bowel and predispose to granuloma formation and chronicity. We tested this hypothesis in human subjects by monitoring responses to killed Escherichia coli injected subcutaneously into the forearm. Accumulation of 111In-labeled neutrophils at these sites and clearance of 32P-labeled bacteria from them were markedly impaired in CD. Locally increased blood flow and bacterial clearance were dependent on the numbers of bacteria injected. Secretion of proinflammatory cytokines by CD macrophages was grossly impaired in response to E. coli or specific Toll-like receptor agonists. Despite normal levels and stability of cytokine messenger RNA, intracellular levels of tumor necrosis factor (TNF) were abnormally low in CD macrophages. Coupled with reduced secretion, these findings indicate accelerated intracellular breakdown. Differential transcription profiles identified disease-specific genes, notably including those encoding proteins involved in vesicle trafficking. Intracellular destruction of TNF was decreased by inhibitors of lysosomal function. Together, our findings suggest that in CD macrophages, an abnormal proportion of cytokines are routed to lysosomes and degraded rather than being released through the normal secretory pathway. PMID:19652016

  4. Weighted ssGBLUP improves genomic selection accuracy for bacterial cold water disease resistance in a rainbow trout population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to compare methods for genomic evaluation in a Rainbow Trout (Oncorhynchus mykiss) population for survival when challenged by Flavobacterium psychrophilum, the causative agent of bacterial cold water disease (BCWD). The used methods were: 1)regular ssGBLUP that assume...

  5. 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...

  6. 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...

  7. 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...

  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. 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...

  10. Yeast supplementation reduced the immune and metabolic responses to a combined viral-bacterial respiratory disease challenge in feedlot heifers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two treatments were evaluated in commercial feedlot heifers to determine the effects of a yeast supplement on immune and metabolic responses to a combined viral-bacterial respiratory disease challenge. Thirty-two beef heifers (324 ± 19.2 kg BW) were selected and randomly assigned to one of two treat...

  11. 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...

  12. Genome-wide association studies identify 25 genetic loci associated with resistance to Bacterial Cold Water Disease in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant mortality and economic losses in salmonids aquaculture. In previous studies we have identified moderate-large effect QTL for BCWD resistance in rainbow trout (Oncorhynchus mykiss). However, the recent availability of a high density SNP array and...

  13. 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...

  14. 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

  15. 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

  16. Investigation of polymerase chain reaction assays to improve detection of bacterial involvement in bovine respiratory disease.

    PubMed

    Bell, Colin J; Blackburn, Paul; Elliott, Mark; Patterson, Tony I A P; Ellison, Sean; Lahuerta-Marin, Angela; Ball, Hywel J

    2014-09-01

    Bovine respiratory disease (BRD) causes severe economic losses to the cattle farming industry worldwide. The major bacterial organisms contributing to the BRD complex are Mannheimia haemolytica, Histophilus somni, Mycoplasma bovis, Pasteurella multocida, and Trueperella pyogenes. The postmortem detection of these organisms in pneumonic lung tissue is generally conducted using standard culture-based techniques where the presence of therapeutic antibiotics in the tissue can inhibit bacterial isolation. In the current study, conventional and real-time polymerase chain reaction (PCR) assays were used to assess the prevalence of these 5 organisms in grossly pneumonic lung samples from 150 animals submitted for postmortem examination, and the results were compared with those obtained using culture techniques. Mannheimia haemolytica was detected in 51 cases (34%) by PCR and in 33 cases (22%) by culture, H. somni was detected in 35 cases (23.3%) by PCR and in 6 cases (4%) by culture, Myc. bovis was detected in 53 cases (35.3%) by PCR and in 29 cases (19.3%) by culture, P. multocida was detected in 50 cases (33.3%) by PCR and in 31 cases (20.7%) by culture, and T. pyogenes was detected in 42 cases (28%) by PCR and in 31 cases (20.7%) by culture, with all differences being statistically significant. The PCR assays indicated positive results for 111 cases (74%) whereas 82 cases (54.6%) were culture positive. The PCR assays have demonstrated a significantly higher rate of detection of all 5 organisms in cases of pneumonia in cattle in Northern Ireland than was detected by current standard procedures.

  17. [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.

  18. [Organic and element carbon in foliar smoke].

    PubMed

    Chen, Hui-yu; Liu Gang; Xu, Hui; Li, Jiu-hai; Wu, Dan

    2015-03-01

    A home-made combustion and sampling apparatus was used to burn green leaves under flaming and smoldering conditions and to collect the smoke generated. The smoke was measured with Organic/Elemental Carbon (OC/EC) Analyzer using IMPROVE thermal-optical reflectance (TOR) method, to investigate the mass fractions and the distribution of OC, EC and eight carbon fractions in foliar smoke. The results showed that in smoldering condition, the mean OC, EC mass fractions of ten foliar smokes were 48.9% and 4.5%, respectively. The mean mass fraction of char-EC (EC1 - POC) was 4.4%. The average emission factors (EF) of particulate matters, OC and EC in smoldering foliar smoke were 102.4 g x kg(-1), 50.0 g x kg(-1) and 4.7 g x kg(-1), respectively. The mean ratios of OC/EC, OC1/OC2 and char-EC/soot-EC (EC1 - POC/EC2 + EC3) in this condition were 11.5, 1.9 and 48.1, respectively. For the foliar smoke emitted in flaming condition, the mean mass fractions of OC, EC and char-EC were 44.9%, 10.9% and 10.7%, respectively. The average EF of PM, OC and EC in flaming smoke were 59.2 g x kg(-1), 26.6 g x kg(-1) and 6.0 g x kg(-1). And the three ratios mentioned above in this condition were 4.8, 1.1 and 133.0, respectively. In conclusion, foliar smoke had higher OC1 mass fractions and OC1/OC2 values in smoldering condition. While flaming foliar smoke had higher char-EC mass fractions and char-EC/soot-EC values. The compositions of OC, EC in foliar smoke varied between different tree species and different combustion conditions. The composition was also obviously different from those of other biomass smoke.

  19. 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.

  20. 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.

  1. Environment arrays: a possible approach for predicting changes in waterborne bacterial disease potential.

    PubMed

    Heinemann, Jack A; Rosén, Håkan; Savill, Marion; Burgos-Caraballo, Sofia; Toranzos, Gary A

    2006-12-01

    Current molecular techniques for identifying bacteria in water have proven useful, but they are not reliably predictive of impending disease outbreaks. Genomics-based approaches will help to detect the presence of pathogens quickly and well before they grow into a population that poses a risk to public health. We suggest that genomics is only one component of the toolbox that will be needed to identify emerging waterborne threats. We propose a methodology beyond genomics, based on activity in the mobile genome. This approach makes use of a new device called an environment array. The array will depend upon the same research necessary for genomics-based detection, but will not require an a priori knowledge of virulence genes. Environment arrays are assembled from molecular profiles of the infectious elements that transfer between bacteria. The advantage of the array is that it monitors the activity of the mobile genome, rather than the presence of particular DNA sequences. Environmental arrays should thus be many times more sensitive than traditional hybridization or PCR-based techniques that target already-known DNA sequences. Mobile elements are known to respond to new environmental conditions that may correlate with a chemical contamination or the bloom of bacterial pathogens, potentially allowing for a much broader application in detecting unknown or unanticipated biological and chemical contaminants.

  2. Potential applications for Annona squamosa leaf extract in the treatment and prevention of foodborne bacterial disease.

    PubMed

    Dholvitayakhun, Achara; Trachoo, Nathanon; Sakee, Uthai; Cushnie, T P Tim

    2013-03-01

    Foodborne disease is a major public health problem. The present study examined Annona squamosa leaves, which are traditionally used to treat diarrhea and other infections, for their potential to be used in modern food safety or medicine. Active constituents were partially purified by ethanol extraction and column chromatography. MICs of the extract were 62.5 to 125 microg/mL against Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus, and 250 microg/mL against Campylobacter jejuni. In time-kill assays, 500 microg/mL of the extract reduced colony forming unit numbers of C. jejuni almost 10 000-fold within 12 hours. Similar decreases were seen against B. cereus, but over a longer time-frame. LC-MS analysis indicated the presence of reticuline and oxophoebine. Assessment of stability by MIC assay showed activity was heat-labile, with loss of activity greatest following high temperature treatments. Activity was relatively stable at refrigeration temperature. These results indicate A. squamosa has broad-spectrum but heat-labile activity against foodborne bacterial pathogens, and bactericidal activity against B. cereus and C. jejuni. This bactericidal activity is not sufficiently rapid for A. squamosa to be used as a food sanitizer, but the extract could potentially be developed as an additive for refrigerated foods, or a modern treatment for foodborne illness.

  3. 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.

  4. Perspectives on the Transition From Bacterial Phytopathogen Genomics Studies to Applications Enhancing Disease Management: From Promise to Practice.

    PubMed

    Sundin, George W; Wang, Nian; Charkowski, Amy O; Castiblanco, Luisa F; Jia, Hongge; Zhao, Youfu

    2016-10-01

    The advent of genomics has advanced science into a new era, providing a plethora of "toys" for researchers in many related and disparate fields. Genomics has also spawned many new fields, including proteomics and metabolomics, furthering our ability to gain a more comprehensive view of individual organisms and of interacting organisms. Genomic information of both bacterial pathogens and their hosts has provided the critical starting point in understanding the molecular bases of how pathogens disrupt host cells to cause disease. In addition, knowledge of the complete genome sequence of the pathogen provides a potentially broad slate of targets for the development of novel virulence inhibitors that are desperately needed for disease management. Regarding plant bacterial pathogens and disease management, the potential for utilizing genomics resources in the development of durable resistance is enhanced because of developing technologies that enable targeted modification of the host. Here, we summarize the role of genomics studies in furthering efforts to manage bacterial plant diseases and highlight novel genomics-enabled strategies heading down this path.

  5. Reduction in diversity of the colonic mucosa associated bacterial microflora in patients with active inflammatory bowel disease

    PubMed Central

    Ott, S J; Musfeldt, M; Wenderoth, D F; Hampe, J; Brant, O; Fölsch, U R; Timmis, K N; Schreiber, S

    2004-01-01

    Background and aims: The intestinal bacterial microflora plays an important role in the aetiology of inflammatory bowel disease (IBD). As most of the colonic bacteria cannot be identified by culture techniques, genomic technology can be used for analysis of the composition of the microflora. Patients and methods: The mucosa associated colonic microflora of 57 patients with active inflammatory bowel disease and 46 controls was investigated using 16S rDNA based single strand conformation polymorphism (SSCP) fingerprint, cloning experiments, and real time polymerase chain reaction (PCR). Results: Full length sequencing of 1019 clones from 16S rDNA libraries (n = 3) revealed an overall bacterial diversity of 83 non-redundant sequences—among them, only 49 known bacterial species. Molecular epidemiology of the composition of the colonic microflora was investigated by SSCP. Diversity of the microflora in Crohn’s disease was reduced to 50% compared with controls (21.7 v 50.4; p<0.0001) and to 30% in ulcerative colitis (17.2 v 50.4; p<0.0001). The reduction in diversity in inflammatory bowel disease was due to loss of normal anaerobic bacteria such as Bacteroides species, Eubacterium species, and Lactobacillus species, as revealed by direct sequencing of variable bands and confirmed by real time PCR. Bacterial diversity in the Crohn’s group showed no association with CARD15/NOD2 status. Conclusions: Mucosal inflammation in inflammatory bowel disease is associated with loss of normal anaerobic bacteria. This effect is independent of NOD2/CARD15 status of patients. PMID:15082587

  6. Bacterial exacerbations of chronic obstructive pulmonary disease. The role of lung function in aetiology of exacerbation.

    PubMed

    Kieszko, Robert; Szmygin-Milanowska, Katarzyna; Chudnicka, Alina; Gołebiowska, Izabela; Łagozna, Jolanta; Milanowski, Janusz

    2003-01-01

    The objective of the study was determination of the most frequent bacterial factors, including Haemophilus parainfluenzae, suspected of causing COPD exacerbation, of the relation between bacterial strains and respiratory system functional status as well as of antibiotic sensitivity of sputum isolated bacteria. The examined group comprised 28 patients treated in the Pulmonary Department of Medical University of Lublin. The subjects fulfilled the criteria of type I COPD bacterial exacerbation. Patient's chest x-ray and spirometry tests were performed. Forty-nine bacterial strains were isolated. In the case of nine patients, more than one strain was isolated. Subjects having H. parainfluenzae in sputum had significantly higher (p<0.05) FVC and FEV1 values comparing to patients with H. influenzae or other Gram-negative bacteria. H. parainfluenzae may be an important etiologic factor of COPD exacerbation. Aetiology of bacterial COPD exacerbation depends on the level of respiratory parameter limitation.

  7. 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

  8. Fine-scale transition to lower bacterial diversity and altered community composition precedes shell disease in laboratory-reared juvenile American lobster.

    PubMed

    Feinman, Sarah G; Unzueta Martínez, Andrea; Bowen, Jennifer L; Tlusty, Michael F

    2017-03-30

    The American lobster Homarus americanus supports a valuable commercial fishery in the Northeastern USA and Maritime Canada; however, stocks in the southern portion of the lobster's range have shown declines, in part due to the emergence of shell disease. Epizootic shell disease is a bacterially induced cuticular erosion that renders even mildly affected lobsters unmarketable because of their appearance, and in more severe cases can cause mortality. Despite the importance of this disease, the associated bacterial communities have not yet been fully characterized. We sampled 2 yr old, laboratory-reared lobsters that displayed signs of shell disease at the site of disease as well as at 0.5, 1, and 1.5 cm away from the site of disease to determine how the bacterial community changed over this fine spatial scale. Illumina sequencing of the 16S rRNA gene revealed a distinct bacterial community at the site of disease, with significant reductions in bacterial diversity and richness compared to more distant sampling locations. The bacterial community composition 0.5 cm from the site of disease was also altered, and there was an observable decrease in bacterial diversity and richness, even though there were no signs of disease at that location. Given the distinctiveness of the bacterial community at the site of disease and 0.5 cm from the site of disease, we refer to these communities as affected and transitionary, and suggest that these bacteria, including the previously proposed causative agent, Aquimarina 'homaria', are important for the initiation and progression of this laboratory model of shell disease.

  9. Induction of Xa10-like genes in rice cultivar Nipponbare confers disease resistance to rice bacterial blight.

    PubMed

    Wang, Jun; Tian, Dongsheng; Gu, Keyu; Yang, Xiaobei; Wang, Lanlan; Zeng, Xuan; Yin, Zhongchao

    2017-03-17

    Bacterial blight of rice, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive bacterial diseases throughout the major rice growing regions in the world. The rice disease resistance (R) genes Xa10 confers race-specific disease resistance to X. oryzae pv. oryzae strains that deliver the corresponding transcription activator-like (TAL) effectors AvrXa10. Upon bacterial infection, AvrXa10 binds specifically to the effector binding element (EBE) in the promoter of the R gene and activates its expression. Xa10 encodes an executor R protein that triggers hypersensitive response and activates disease resistance. Rice cultivar Nipponbare carries two Xa10-like genes in its genome, of which one is the susceptible allele of the Xa23 gene, a Xa10-like TAL effector-dependent executor R gene isolated recently from rice cultivar CBB23. However, the function of the two Xa10-like genes in disease resistance to X. oryzae pv. oryzae strains has not been investigated. Here we designated the two Xa10-like genes as Xa10-Ni and Xa23-Ni and characterized their function for disease resistance to rice bacterial blight. Both Xa10-Ni and Xa23-Ni provided disease resistance to X. oryzae pv. oryzae strains that deliver the matching artificially designed TAL effectors (dTALEs). Transgenic rice plants containing Xa10-Ni and Xa23-Ni under the Xa10 promoter provided specific disease resistance to X. oryzae pv. oryzae strains that deliver AvrXa10. Xa10-Ni and Xa23-Ni knock-out mutants abolished dTALE-dependent disease resistance to X. oryzae pv. oryzae. Heterologous expression of Xa10-Ni and Xa23-Ni in Nicotiana benthamiana triggered cell death. The 19-amino acid residues at the N-terminal regions of XA10 or XA10-Ni are dispensable for their function in inducing cell death in N. benthamiana and the C-terminal regions of XA10, XA10-Ni and XA23-Ni are interchangeable among each other without affecting their function. Like XA10, both XA10-Ni and XA23-Ni locate to the endoplasmic

  10. Characterization of a disease susceptibility locus for exploring an efficient way to improve rice resistance against bacterial blight.

    PubMed

    Cheng, Qi; Mao, Weihua; Xie, Wenya; Liu, Qinsong; Cao, Jianbo; Yuan, Meng; Zhang, Qinglu; Li, Xianghua; Wang, Shiping

    2017-03-01

    Bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is the most harmful bacterial disease of rice worldwide. Previously, we characterized major disease resistance (MR) gene xa25, which confers race-specific resistance to Xoo strain PXO339. The xa25 is a recessive allele of the SWEET13 locus, but SWEET13's interaction with PXO339 and how efficiently using this locus for rice breeding still need to be defined. Here we show that the SWEET13 allele from rice Zhenshan 97 is a susceptibility gene to PXO339. Using this allele's promoter to regulate xa25 resulted in disease, suggesting that the promoter is a key determinant in SWEET13 caused disease in Zhanshan 97 after PXO339 infection. PXO339 transcriptionally induces SWEET13 to cause disease. Partial suppressing SWEET13 expression leads to a high level of resistance to PXO339. Thus, the transcriptionally suppressed SWEET13 functions as xa25 in resistance to PXO339. Hybrid rice is widely grown in many countries. However, recessive MR genes have not been efficiently used for disease resistance breeding in hybrid rice production for both parents of the hybrid have to carry the same recessive gene. However, the suppressed SWEET13 functions dominantly, which will have advantage to improve the resistance of hybrid rice to xa25-incomptible Xoo.

  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. Ectopic activation of the rice NLR heteropair RGA4/RGA5 confers resistance to bacterial blight and bacterial leaf streak diseases.

    PubMed

    Hutin, Mathilde; Césari, Stella; Chalvon, Véronique; Michel, Corinne; Tran, Tuan Tu; Boch, Jens; Koebnik, Ralf; Szurek, Boris; Kroj, Thomas

    2016-10-01

    Bacterial blight (BB) and bacterial leaf streak (BLS) are important diseases in Oryza sativa caused by Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc), respectively. In both bacteria, transcription activator-like (TAL) effectors are major virulence determinants that act by transactivating host genes downstream of effector-binding elements (EBEs) bound in a sequence-specific manner. Resistance to Xoo is mostly related to the action of TAL effectors, either by polymorphisms that prevent the induction of susceptibility (S) genes or by executor (R) genes with EBEs embedded in their promoter, and that induce cell death and resistance. For Xoc, no resistance sources are known in rice. Here, we investigated whether the recognition of effectors by nucleotide binding and leucine-rich repeat domain immune receptors (NLRs), the most widespread resistance mechanism in plants, is also able to stop BB and BLS. In one instance, transgenic rice lines harboring the AVR1-CO39 effector gene from the rice blast fungus Magnaporthe oryzae, under the control of an inducible promoter, were challenged with transgenic Xoo and Xoc strains carrying a TAL effector designed to transactivate the inducible promoter. This induced AVR1-CO39 expression and triggered BB and BLS resistance when the corresponding Pi-CO39 resistance locus was present. In a second example, the transactivation of an auto-active NLR by Xoo-delivered designer TAL effectors resulted in BB resistance, demonstrating that NLR-triggered immune responses efficiently control Xoo. This forms the foundation for future BB and BLS disease control strategies, whereupon endogenous TAL effectors will target synthetic promoter regions of Avr or NLR executor genes.

  13. Analyzing structural changes in SNOMED CT's Bacterial infectious diseases using a visual semantic delta.

    PubMed

    Ochs, Christopher; Case, James T; Perl, Yehoshua

    2017-03-01

    Thousands of changes are applied to SNOMED CT's concepts during each release cycle. These changes are the result of efforts to improve or expand the coverage of health domains in the terminology. Understanding which concepts changed, how they changed, and the overall impact of a set of changes is important for editors and end users. Each SNOMED CT release comes with delta files, which identify all of the individual additions and removals of concepts and relationships. These files typically contain tens of thousands of individual entries, overwhelming users. They also do not identify the editorial processes that were applied to individual concepts and they do not capture the overall impact of a set of changes on a subhierarchy of concepts. In this paper we introduce a methodology and accompanying software tool called a SNOMED CT Visual Semantic Delta ("semantic delta" for short) to enable a comprehensive review of changes in SNOMED CT. The semantic delta displays a graphical list of editing operations that provides semantics and context to the additions and removals in the delta files. However, there may still be thousands of editing operations applied to a set of concepts. To address this issue, a semantic delta includes a visual summary of changes that affected sets of structurally and semantically similar concepts. The software tool for creating semantic deltas offers views of various granularities, allowing a user to control how much change information they view. In this tool a user can select a set of structurally and semantically similar concepts and review the editing operations that affected their modeling. The semantic delta methodology is demonstrated on SNOMED CT's Bacterial infectious disease subhierarchy, which has undergone a significant remodeling effort over the last two years.

  14. 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...

  15. 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

  16. 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

  17. 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.

  18. 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...

  19. Intestinal microbiota in metabolic diseases: from bacterial community structure and functions to species of pathophysiological relevance.

    PubMed

    Clavel, Thomas; Desmarchelier, Charles; Haller, Dirk; Gérard, Philippe; Rohn, Sascha; Lepage, Patricia; Daniel, Hannelore

    2014-07-01

    The trillions of bacterial cells that colonize the mammalian digestive tract influence both host physiology and the fate of dietary compounds. Gnotobionts and fecal transplantation have been instrumental in revealing the causal role of intestinal bacteria in energy homeostasis and metabolic dysfunctions such as type-2 diabetes. However, the exact contribution of gut bacterial metabolism to host energy balance is still unclear and knowledge about underlying molecular mechanisms is scant. We have previously characterized cecal bacterial community functions and host responses in diet-induced obese mice using omics approaches. Based on these studies, we here discuss issues on the relevance of mouse models, give evidence that the metabolism of cholesterol-derived compounds by gut bacteria is of particular importance in the context of metabolic disorders and that dominant species of the family Coriobacteriaceae are good models to study these functions.

  20. Simultaneous Detection of Three Bacterial Seed-Borne Diseases in Rice Using Multiplex Polymerase Chain Reaction

    PubMed Central

    Kang, In Jeong; Kang, Mi-Hyung; Noh, Tae-Hwan; Shim, Hyeong Kwon; Shin, Dong Bum; Heu, Suggi

    2016-01-01

    Burkholderia glumae (bacterial grain rot), Xanthomonas oryzae pv. oryzae (bacterial leaf blight), and Acidovorax avenae subsp. avenae (bacterial brown stripe) are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae, and transposase A gene sequence for X. oryzae pv. oryzae, three sets of primers had been designed to produce 402 bp for B. glumae, 490 bp for X. oryzae, and 290 bp for A. avenae subsp. avenae with the 63°C as an optimum annealing temperature. Samples collected from naturally infected fields were detected with two bacteria, B. glumae and A. avenae subsp. avenae but X. oryzae pv. oryzae was not detected. This assay can be used to identify pathogens directly from infected seeds, and will be an effective tool for the identification of the three pathogens in rice plants. PMID:27904465

  1. Foliar δ15N is affected by foliar nitrogen uptake, soil nitrogen, and mycorrhizae along a nitrogen deposition gradient.

    PubMed

    Vallano, Dena M; Sparks, Jed P

    2013-05-01

    Foliar nitrogen isotope (δ(15)N) composition patterns have been linked to soil N, mycorrhizal fractionation, and within-plant fractionations. However, few studies have examined the potential importance of the direct foliar uptake of gaseous reactive N on foliar δ(15)N. Using an experimental set-up in which the rate of mycorrhizal infection was reduced using a fungicide, we examined the influence of mycorrhizae on foliar δ(15)N in potted red maple (Acer rubrum) seedlings along a regional N deposition gradient in New York State. Mycorrhizal associations altered foliar δ(15)N values in red maple seedlings from 0.06 to 0.74 ‰ across sites. At the same sites, we explored the predictive roles of direct foliar N uptake, soil δ(15)N, and mycorrhizae on foliar δ(15)N in adult stands of A. rubrum, American beech (Fagus grandifolia), black birch (Betula lenta), and red oak (Quercus rubra). Multiple regression analysis indicated that ambient atmospheric nitrogen dioxide (NO2) concentration explained 0, 69, 23, and 45 % of the variation in foliar δ(15)N in American beech, red maple, red oak, and black birch, respectively, after accounting for the influence of soil δ(15)N. There was no correlation between foliar δ(13)C and foliar %N with increasing atmospheric NO2 concentration in most species. Our findings suggest that total canopy uptake, and likely direct foliar N uptake, of pollution-derived atmospheric N deposition may significantly impact foliar δ(15)N in several dominant species occurring in temperate forest ecosystems.

  2. 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

  3. Bacterial endotoxin isolated from a water spray air humidification system as a putative agent of occupation-related lung disease.

    PubMed Central

    Flaherty, D K; Deck, F H; Cooper, J; Bishop, K; Winzenburger, P A; Smith, L R; Bynum, L; Witmer, W B

    1984-01-01

    Outbreaks of hypersensitivity pneumonitis or humidifier fever were attributed to the inhalation of organic material aerosolized by a chilled-water spray humidification system. The purpose of this study was to isolate and characterize the serologically detectable antigen(s) present in extracts obtained from the humidification system. By using bicarbonate or phenol-water extractions or both, the antigen was isolated and characterized, using colorimetry, gas-liquid chromatography, reverse-phase high-performance liquid chromatography, and X-ray fluorescence. Carbohydrates, hexosamines, phosphorus, and even-numbered saturated and unsaturated fatty acids were constituents of the serologically detectable antigen. When tested in in vivo and in vitro assays, the antigen had demonstrable endotoxin activity. All subjects with biopsy-proven lung disease and a majority of subjects suspected of having lung disease had antibodies directed toward the purified endotoxin. The data strongly suggest that an aerosolized bacterial endotoxin is a putative agent inducing lung disease. PMID:6690401

  4. 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...

  5. Monitoring bacterial panicle blight disease of rice and germplasm evaluation for resistance in Arkansas in 2015

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is a major cereal crop that contributes significantly to the global food security. Rice production is challenged by both abiotic and biotic stresses. Rice bacterial panicle blight (BPB) has been recognized as one of the major biotic factors that can cause severe yield loss in Southern rice stat...

  6. 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...

  7. Role of Bacterial Communities in the Natural Suppression of Rhizoctonia solani Bare Patch Disease of Wheat (Triticum aestivum L.)

    PubMed Central

    Yin, Chuntao; Hulbert, Scot H.; Schroeder, Kurtis L.; Mavrodi, Olga; Mavrodi, Dmitri; Dhingra, Amit; Schillinger, William F.

    2013-01-01

    Rhizoctonia bare patch and root rot disease of wheat, caused by Rhizoctonia solani AG-8, develops as distinct patches of stunted plants and limits the yield of direct-seeded (no-till) wheat in the Pacific Northwest of the United States. At the site of a long-term cropping systems study near Ritzville, WA, a decline in Rhizoctonia patch disease was observed over an 11-year period. Bacterial communities from bulk and rhizosphere soil of plants from inside the patches, outside the patches, and recovered patches were analyzed by using pyrosequencing with primers designed for 16S rRNA. Taxa in the class Acidobacteria and the genus Gemmatimonas were found at higher frequencies in the rhizosphere of healthy plants outside the patches than in that of diseased plants from inside the patches. Dyella and Acidobacteria subgroup Gp7 were found at higher frequencies in recovered patches. Chitinophaga, Pedobacter, Oxalobacteriaceae (Duganella and Massilia), and Chyseobacterium were found at higher frequencies in the rhizosphere of diseased plants from inside the patches. For selected taxa, trends were validated by quantitative PCR (qPCR), and observed shifts of frequencies in the rhizosphere over time were duplicated in cycling experiments in the greenhouse that involved successive plantings of wheat in Rhizoctonia-inoculated soil. Chryseobacterium soldanellicola was isolated from the rhizosphere inside the patches and exhibited significant antagonism against R. solani AG-8 in vitro and in greenhouse tests. In conclusion, we identified novel bacterial taxa that respond to conditions affecting bare patch disease symptoms and that may be involved in suppression of Rhizoctonia root rot and bare batch disease. PMID:24056471

  8. 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

  9. 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

  10. 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.

  11. Transcriptome of American oysters, Crassostrea virginica, in response to bacterial challenge: insights into potential mechanisms of disease resistance.

    PubMed

    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.

  12. Is it easy to clinically distinguish inflammatory arthritis of bacterial origin from monoarthritis attacks of gout disease?

    PubMed

    Atik, O Şahap; Ergişi, Yılmaz; Ayanoğlu, Tacettin; Tokgöz, Mehmet Ali; Sezgin, Erdem Aras; Göçün, Pınar Uyar

    2016-12-01

    Acute monoarthritis is a common situation in orthopedic emergency where the patient presents with typical inflamed joint. It is hard to clinically distinguish inflammatory arthritis of bacterial origin from monoarthritis attacks of gout disease. If these two situations, which are the most common causes of acute monoarthritis, are misdiagnosed, outcomes might be catastrophic and costly. Synovial fluid analysis is the most reliable method for confirming the diagnosis although it might not always lead to definitive diagnosis. If there is clinical suspicion for crystal arthropathy, repeated examinations may provide benefits for confirming the diagnosis.

  13. 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

  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 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.

  16. 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.

  17. 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...

  18. Genetic and metabolic signals during acute enteric bacterial infection alter the microbiota and drive progression to chronic inflammatory disease

    SciTech Connect

    Kamdar, Karishma; Khakpour, Samira; Chen, Jingyu; Leone, Vanessa; Brulc, Jennifer; Mangatu, Thomas; Antonopoulos, Dionysios A.; Chang, Eugene B; Kahn, Stacy A.; Kirschner, Barbara S; Young, Glenn; DePaolo, R. William

    2016-01-13

    Chronic inflammatory disorders are thought to arise due to an interplay between predisposing host genetics and environmental factors. For example, the onset of inflammatory bowel disease is associated with enteric proteobacterial infection, yet the mechanistic basis for this association is unclear. We have shown previously that genetic defiency in TLR1 promotes acute enteric infection by the proteobacteria Yersinia enterocolitica. Examining that model further, we uncovered an altered cellular immune response that promotes the recruitment of neutrophils which in turn increases metabolism of the respiratory electron acceptor tetrathionate by Yersinia. These events drive permanent alterations in anti-commensal immunity, microbiota composition, and chronic inflammation, which persist long after Yersinia clearence. Deletion of the bacterial genes involved in tetrathionate respiration or treatment using targeted probiotics could prevent microbiota alterations and inflammation. Thus, acute infection can drive long term immune and microbiota alterations leading to chronic inflammatory disease in genetically predisposed individuals.

  19. Amikacin in Newborn Infants: Comparative Pharmacology with Kanamycin and Clinical Efficacy in 45 Neonates with Bacterial Diseases

    PubMed Central

    Howard, Jorge B.; McCracken, George H.; Trujillo, Hugo; Mohs, Edgar

    1976-01-01

    The pharmacokinetic properties of amikacin (BBK8) were similar to those of kanamycin in newborn infants. Peak serum concentrations of both drugs were in the range of 15 to 25 μg/ml with the exception of kanamycin in babies weighing greater than 2,000 g at birth where peak levels were 12.5 to 15 μg/ml. Volumes of distribution, plasma clearances, and serum half-life values were comparable for the two drugs. The clinical and bacteriological responses to amikacin therapy were assessed in 45 neonates with bacterial diseases. A case fatality rate of 26% was observed in infants with septicemia and/or meningitis, whereas no deaths occurred among 22 infants with urinary tract and mucocutaneous infections. Cultures from infected sites were sterile within 72 h of initiating amikacin therapy in 47% of the infants, continued positive for greater than 72 h in 31%, and were not reevaluated during therapy in 22%. The clinical response was judged to be satisfactory in 92% of the surviving infants. The efficacy of amikacin was comparable to that of kanamycin or gentamicin in neonatal bacterial diseases. PMID:984762

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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…

  6. 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.

  7. 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.

  8. Efficacy of Fungicides for Control of Rosette, Fruit, Foliar, and Cane Diseases of ‘Kiowa’ and ‘Chickasaw’ Erect Blackberries Grown in the Southeastern U.S.A.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rosette disease, Cercosporella rubi, is often severe on erect blackberries grown in the southeastern U.S. and if not controlled, may severely limit fruit production. Pre- and post-harvest fruit diseases also reduce fruit production and quality. A series of trials were conducted in south Mississippi...

  9. 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

  10. 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.

  11. 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

  12. Real-time qPCR improves meningitis pathogen detection in invasive bacterial-vaccine preventable disease surveillance in Fiji

    PubMed Central

    Dunne, Eileen M.; Mantanitobua, Silivia; Singh, Shalini P.; Reyburn, Rita; Tuivaga, Evelyn; Rafai, Eric; Tikoduadua, Lisi; Porter, Barbara; Satzke, Catherine; Strachan, Janet E.; Fox, Kimberly K.; Jenkins, Kylie M.; Jenney, Adam; Baro, Silo; Mulholland, E. Kim; Kama, Mike; Russell, Fiona M.

    2016-01-01

    As part of the World Health Organization Invasive Bacterial-Vaccine Preventable Diseases (IB-VPD) surveillance in Suva, Fiji, cerebrospinal fluid (CSF) samples from suspected meningitis patients of all ages were examined by traditional methods (culture, Gram stain, and latex agglutination for bacterial antigen) and qPCR for Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Of 266 samples tested, pathogens were identified in 47 (17.7%). S. pneumoniae was the most common pathogen detected (n = 17) followed by N. meningitidis (n = 13). The use of qPCR significantly increased detection of IB-VPD pathogens (P = 0.0001): of 35 samples that were qPCR positive for S. pneumoniae, N. meningitidis, and H. influenzae, only 10 were culture positive. This was particularly relevant for N. meningitidis, as only 1/13 cases was culture positive. Molecular serotyping by microarray was used to determine pneumococcal serotypes from 9 of 16 (56%) of samples using DNA directly extracted from CSF specimens. Results indicate that qPCR significantly increases detection of S. pneumoniae, N. meningitidis, and H. influenzae in CSF, and that application of molecular diagnostics is a feasible way to enhance local and global surveillance for IB-VPD. PMID:28009001

  13. 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.

  14. Inhaled diesel engine emissions reduce bacterial clearance and exacerbate lung disease to Pseudomonas aeruginosa infection in vivo.

    PubMed

    Harrod, Kevin S; Jaramillo, Richard J; Berger, Jennifer A; Gigliotti, Andrew P; Seilkop, Steven K; Reed, Matthew D

    2005-01-01

    Despite experimental evidence supporting an adverse role for air pollution in models of human disease, little has been done in the way of assessing the health effects of inhalation of whole mixtures from defined sources at exposure levels relevant to ambient environmental exposures. The current study assessed the impact of inhaled diesel engine emissions (DEE) in modulating clearance of Pseudomonas aeruginosa (P.a.) and the adverse effects of infection to the pulmonary epithelium. At DEE concentrations representing from high ambient to high occupational exposures, mice were exposed to DEE continuously for one week or six months (6 h/day), and subsequently infected with P.a. by intratracheal instillation. At 18 h following P.a. infection, prior exposure to DEE impaired bacterial clearance and exacerbated lung histopathology during infection. To assess the airway epithelial cell changes indicative of lung pathogenesis, markers of specific lung epithelial cell populations were analyzed by immunohistochemistry. Both ciliated and non-ciliated airway epithelial cell numbers were decreased during P.a. infection by DEE exposure in a concentration-dependent manner. Furthermore, the lung transcription regulator, thyroid transcription factor 1 (TTF-1), was also decreased during P.a. infection by prior exposure to DEE concordant with changes in airway populations. These findings are consistent with the notion that environmental levels of DEE can decrease the clearance of P.a. and increase lung pathogenesis during pulmonary bacterial infection.

  15. 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.

  16. Soybean (Glycine max L. Merr.) sprouts germinated under red light irradiation induce disease resistance against bacterial rotting disease.

    PubMed

    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.

  17. 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

  18. 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.

  19. Probiotics, immunostimulants, plant products and oral vaccines, and their role as feed supplements in the control of bacterial fish diseases.

    PubMed

    Newaj-Fyzul, A; Austin, B

    2015-11-01

    There is a rapidly increasing literature pointing to the success of probiotics, immunostimulants, plant products and oral vaccines in immunomodulation, namely stimulation of the innate, cellular and/or humoral immune response, and the control of bacterial fish diseases. Probiotics are regarded as live micro-organisms administered orally and leading to health benefits. However, in contrast with the use in terrestrial animals, a diverse range of micro-organisms have been evaluated in aquaculture with the mode of action often reflecting immunomodulation. Moreover, the need for living cells has been questioned. Also, key subcellular components, including lipopolysaccharides, have been attributed to the beneficial effect in fish. Here, there is a link with immunostimulants, which may also be administered orally. Furthermore, numerous plant products have been reported to have health benefits, namely protection against disease for which stimulation of some immune parameters has been reported. Oral vaccines confer protection against some diseases, although the mode of action is usually linked to humoral rather than the innate and cellular immune responses. This review explores the relationship between probiotics, immunostimulants, plant products and oral vaccines.

  20. 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

  1. Resistance of different stocks and transferrin genotypes of coho salmon, Oncorhynchus kisutch, and steelhead trout, Salmo gairdneri, to bacterial kidney disease and vibriosis

    USGS Publications Warehouse

    Winter , Gary W.; Schreck, Carl B.; McIntyre, John D.

    1979-01-01

    Juvenile coho salmon and steelhead trout ofdifferentstocks and three transferrin genotypes(AA, AC, and CCl, all reared in identical or similar environments, were experimentally infected with Corynebacterium sp., the causative agent ofbacterial kidney disease, or with Vibrio anguillarum, the causative agent of vibriosis. Mortality due to the pathogens was compared among stocks within a species and among transferrin genotypes within a stock to determine whetherthere was a geneticbasis for resistance to disease. Differences in resistance to bacterial kidney disease among coho salmon stocks had a genetic basis. Stock susceptibility to vibriosis was strongly influenced by environmental factors. Coho salmon orsteelhead trout of one stock may be resistant to one disease but susceptible to another. The importance of transferrin genotype of coho salmon in resistance to bacterial kidney disease was stock specific; in stocks that showed differential resistance of genotypes, the AA was the most susceptible. No differencesin resistance to vibriosis were observed among transferrin genotypes.

  2. 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

  3. Seasonal Drivers of Pneumococcal Disease Incidence: Impact of Bacterial Carriage and Viral Activity

    PubMed Central

    Weinberger, Daniel M.; Grant, Lindsay R.; Steiner, Claudia A.; Weatherholtz, Robert; Santosham, Mathuram; Viboud, Cécile; O'Brien, Katherine L.

    2014-01-01

    Background. Winter-seasonal epidemics of pneumococcal disease provide an opportunity to understand the drivers of incidence. We sought to determine whether seasonality of invasive pneumococcal disease is caused by increased nasopharyngeal transmission of the bacteria or increased susceptibility to invasive infections driven by cocirculating winter respiratory viruses. Methods. We analyzed pneumococcal carriage and invasive disease data collected from children <7 years old in the Navajo/White Mountain Apache populations between 1996 and 2012. Regression models were used to quantify seasonal variations in carriage prevalence, carriage density, and disease incidence. We also fit a multivariate model to determine the contribution of carriage prevalence and RSV activity to pneumococcal disease incidence while controlling for shared seasonal factors. Results. The seasonal patterns of invasive pneumococcal disease epidemics varied significantly by clinical presentation: bacteremic pneumococcal pneumonia incidence peaked in late winter, whereas invasive nonpneumonia pneumococcal incidence peaked in autumn. Pneumococcal carriage prevalence and density also varied seasonally, with peak prevalence occurring in late autumn. In a multivariate model, RSV activity was associated with significant increases in bacteremic pneumonia cases (attributable percentage, 15.5%; 95% confidence interval [CI], 1.8%–26.1%) but was not associated with invasive nonpneumonia infections (8.0%; 95% CI, −4.8% to 19.3%). In contrast, seasonal variations in carriage prevalence were associated with significant increases in invasive nonpneumonia infections (31.4%; 95% CI, 8.8%–51.4%) but not with bacteremic pneumonia. Conclusions.The seasonality of invasive pneumococcal pneumonia could be due to increased susceptibility to invasive infection triggered by viral pathogens, whereas seasonality of other invasive pneumococcal infections might be primarily driven by increased nasopharyngeal

  4. First confirmed report of a bacterial brood disease in stingless bees.

    PubMed

    Shanks, Jenny Lee; Haigh, Anthony Mark; Riegler, Markus; Spooner-Hart, Robert Neil

    2017-03-01

    Susceptibility to brood pathogens in eusocial stingless bees (Meliponini), alternative pollinators to honey bees, is unknown. Brood losses in managed colonies of the Australian stingless bee, Tetragonula carbonaria, were studied over 20months. We isolated a disease-causing bacterium, Lysinibacillus sphaericus (Firmicutes, Bacillaceae), from worker and queen larvae, brood cell provisions and honey stores. Pathogenicity experiments confirmed this bacterium as the causal organism. It took 22days from infection to first appearance of brood disease symptoms. This is the first confirmed record of a brood pathogen in stingless bees.

  5. [Studies on bacterial agents in acute diarrheal disease (1985-1987)].

    PubMed

    Taguchi, M; Kobayashi, K; Harada, K; Kanno, I

    1989-06-01

    A three-year epidemiological study (from January 1985 to December 1987) was carried out on sporadic cases of acute diarrhea. A total of 2889 fecal specimens in Cary-Blair transport medium were examined for bacterial enteric pathogens, and 832 strains of fifteen species were isolated from 739 specimens, 73 patients having two or more pathogens. C. jejuni shared 51.7%, Salmonella spp. 18.3%, V. parahaemolyticus 10.3%, and Aeromonas spp. 15.7% of total fecal specimens. Isolation rates of C. jejuni and Salmonella spp. in children under the age of fifteen years (19.3%, 6.4%) were higher than those of older years (9.8%, 3.9%), respectively. Isolation of C. jejuni decreased to 24% (12/50) during 2-4 days storage at room temperature in Cary-Blair transport medium, which showed the necessity of rapid plating for isolation of C. jejuni from fecal specimens. Incidence of A. caviae in children up to ten years of age was significantly higher as compared with those of other Aeromonas species. Desoxycholate-hydrogen sulfide-xylose-agar (DHXA) was used for direct plating technique and for plating after enrichment with alkaline peptone water (without NaCl), which was found suitable as an enrichment medium for Aeromonas spp. Enterohemorrhagic E. coli (EHEC) O157:H7 was isolated from 3 patients by using desoxycholate-hydrogen sulfide-sorbitol-agar (DHSA).

  6. Expression of the Bs2 pepper gene confers resistance to bacterial spot disease in tomato

    PubMed Central

    Tai, Thomas H.; Dahlbeck, Douglas; Clark, Eszter T.; Gajiwala, Paresh; Pasion, Romela; Whalen, Maureen C.; Stall, Robert E.; Staskawicz, Brian J.

    1999-01-01

    The Bs2 resistance gene of pepper specifically recognizes and confers resistance to strains of Xanthomonas campestris pv. vesicatoria that contain the corresponding bacterial avirulence gene, avrBs2. The involvement of avrBs2 in pathogen fitness and its prevalence in many X. campestris pathovars suggests that the Bs2 gene may be durable in the field and provide resistance when introduced into other plant species. Employing a positional cloning strategy, the Bs2 locus was isolated and the gene was identified by coexpression with avrBs2 in an Agrobacterium-mediated transient assay. A single candidate gene, predicted to encode motifs characteristic of the nucleotide binding site–leucine-rich repeat class of resistance genes, was identified. This gene specifically controlled the hypersensitive response when transiently expressed in susceptible pepper and tomato lines and in a nonhost species, Nicotiana benthamiana, and was designated as Bs2. Functional expression of Bs2 in stable transgenic tomatoes supports its use as a source of resistance in other Solanaceous plant species. PMID:10570214

  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. 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

  9. Bacterial markers of periodontal diseases and their practical significance in dentistry.

    PubMed

    Chukhlovin, A B; Solovyova, A M; Matelo, S K; Kobiyasova, I V; Morosova, E B; Hokhlacheva, A V; Teplyakov, B G; Syssoev, K A; Konstantinova, V E; Matelo, L N; Totolian, Areg A

    2007-10-01

    The incidence and prevalence of Actinobacillus actinomycetemcomitans, Porphyronmonas gingivalis, and Tannerella forsythensis in specimens of subgingival dental deposit were evaluated in 495 residents of St. Petersburg aged 6-82 years. The microorganisms were detected by gene-specific PCR of 16S rDNA. In accordance with age-specific increase in the incidence of gingival diseases, the percentage of samples containing T. forsythensis and P. gingivalis was significantly higher in adult and elderly patients in comparison with adolescents. The presence of T. forsythensis significantly correlated with the presence of gingivitis and dental deposit. In addition, the incidence of T. forsythensis was significantly higher in tobacco smokers. These results attest to a relationship between T. forsythensis infection and more frequent periodontal diseases associated with aging and tobacco smoking.

  10. 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

  11. The Role of Bacterial Endotoxins in Occupational Diseases Caused by Inhaling Vegetable Dusts

    PubMed Central

    Pernis, B.; Vigliani, E. C.; Cavagna, C.; Finulli, M.

    1961-01-01

    A large group of occupational diseases connected with the inhalation of various vegetable dusts, especially in the textile industry, have certain main symptoms in common such as fever, coughing, dyspnoea, and general malaise. In most cases the symptoms are more prominent on Mondays or on resuming work after one or more days of interruption. The symptomatology of these diseases and the Monday effect leads to the hypothesis that they are due to the inhalation of the endotoxins of gram-negative bacteria that contaminate the various vegetable materials, the Monday effect being connected with the phenomenon of tolerance to the endotoxins. Support for this view came from the demonstration of the constant presence of endotoxins in cotton dusts in textile mills and from the study of the effects of the inhalation of purified endotoxins in rabbits and man. Images PMID:13734460

  12. Fighting fire with fire: is it time to use probiotics to manage pathogenic bacterial diseases?

    PubMed

    Heineman, John; Bubenik, Sara; McClave, Stephen; Martindale, Robert

    2012-08-01

    Probiotics, when considered in clinical practice, have traditionally been used for prophylaxis; however, there is growing data suggesting treatment benefits in numerous disease states. In this review, we focus on probiotics as treatment for and prevention of several acute and chronic infectious processes including Helicobacter pylori, Clostridium difficile, necrotizing enterocolitis, ventilator-associated pneumonia, vancomycin-resistant enterococci, and nonalcoholic fatty liver disease. It is inaccurate to generalize findings observed in a single probiotic species to all probiotics. This reasoning is due to the variability of colonizing abilities of native intestinal floras, probiotic or otherwise, secondary to different combinations, doses, and duration of treatments. Given these limitations, multiple animal and human studies have shown anti-inflammatory and selective antimicrobial effects of specific probiotics. Some studies suggest a role for probiotics as supplemental treatment, in combination with antibiotics, for the aforementioned disease processes. It is apparent from this review that the efficacy of probiotics is widely variable and multifaceted. More focused clinical and basic science research is necessary to better understand the treatment potential of various probiotics.

  13. 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

  14. 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...

  15. 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...

  16. 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...

  17. 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 Central

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

    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

  18. Genomic selection models double the accuracy of predicted breeding values for bacterial cold water disease resistance compared to a traditional pedigree-based model in rainbow trout aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously we have shown that bacterial cold water disease (BCWD) resistance in rainbow trout can be improved using traditional family-based selection, but progress has been limited to exploiting only between-family genetic variation. Genomic selection (GS) is a new alternative enabling exploitation...

  19. Genome-enabled selection doubles the accuracy of predicted breeding values for bacterial cold water disease resistance compared to traditional family-based selection in rainbow trout aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have shown previously that bacterial cold water disease (BCWD) resistance in rainbow trout can be improved using traditional family-based selection, but progress has been limited to exploiting only between-family genetic variation. Genomic selection (GS) is a new alternative enabling exploitation...

  20. 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

  1. Chronic obstructive pulmonary disease (COPD): evaluation from clinical, immunological and bacterial pathogenesis perspectives.

    PubMed

    Hassett, Daniel J; Borchers, Michael T; Panos, Ralph J

    2014-03-01

    Chronic obstructive pulmonary disease (COPD), a disease manifested by significantly impaired airflow, afflicts ∼14.2 million cases in the United States alone with an estimated 63 million people world-wide. Although there are a number of causes, the predominant cause is excessive tobacco smoke. In fact, in China, there have been estimates of 315,000,000 people that smoke. Other less frequent causes are associated with indirect cigarette smoke, air pollutants, biomass fuels, and genetic mutations. COPD is often associated with heart disease, lung cancer, osteoporosis and conditions can worsen in patients with sudden falls. COPD also affects both innate and adaptive immune processes. Cigarette smoke increases the expression of matrix metalloproteases and proinflammatory chemokines and increases lung titers of natural killer cells and neutrophils. Yet, neutrophil reactive oxygen species (ROS) mediated by the phagocytic respiratory burst and phagocytosis is impaired by nicotine. In contrast to innate immunity in COPD, dendritic cells represent leukocytes recruited to the lung that link the innate immune responses to adaptive immune responses by activating naïve T cells through antigen presentation. The autoimmune process that is also a significant part of inflammation associated with COPD. Moreover, coupled with restricted FEV1 values, are the prevalence of patients with single or multiple infections by bacteria, viruses and fungi. Finally, we focus on one of the more problematic infectious agents, the Gram-negative opportunistic pathogenic bacterium, Pseudomonas aeruginosa. Specifically, we delve into the development of highly problematic biofilm infections that are highly refractory to conventional antibiotic therapies in COPD. We offer a non-conventional, biocidal treatment that may be effective for COPD airway infections as well as with combinations of current antibiotic regimens for more effective treatment outcomes and relief for patients with COPD.

  2. Enteric bacterial proteases in inflammatory bowel disease- pathophysiology and clinical implications.

    PubMed

    Carroll, Ian M; Maharshak, Nitsan

    2013-01-01

    Numerous reports have identified a dysbiosis in the intestinal microbiota in patients suffering from inflammatory bowel diseases (IBD), yet the mechanism(s) in which this complex microbial community initiates or perpetuates inflammation remains unclear. The purpose of this review is to present evidence for one such mechanism that implicates enteric microbial derived proteases in the pathogenesis of IBD. We highlight and discuss studies demonstrating that proteases and protease receptors are abundant in the digestive system. Additionally, we investigate studies demonstrating an association between increased luminal protease activity and activation of protease receptors, ultimately resulting in increased intestinal permeability and exacerbation of colitis in animal models as well as in human IBD. Proteases are essential for the normal functioning of bacteria and in some cases can serve as virulence factors for pathogenic bacteria. Although not classified as traditional virulence factors, proteases originating from commensal enteric bacteria also have a potential association with intestinal inflammation via increased enteric permeability. Reports of increased protease activity in stools from IBD patients support a possible mechanism for a dysbiotic enteric microbiota in IBD. A better understanding of these pathways and characterization of the enteric bacteria involved, their proteases, and protease receptors may pave the way for new therapeutic approaches for these diseases.

  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. Bacterial probiotics as an aid in the control of Clostridium difficile disease in neonatal pigs

    PubMed Central

    Arruda, Paulo H. E.; Madson, Darin M.; Ramirez, Alejandro; Rowe, Eric W.; Songer, J. Glenn

    2016-01-01

    Although Clostridium difficile infection (CDI) is a common disease in swine, there is a lack of prevention strategies. The objectives of this study were to evaluate: i) the effectiveness of Lactobacillus spp. and ii) non-toxigenic C. difficile (NTCD) as prevention for the development of CDI in piglets. Cesarean-derived piglets (N = 150) were randomly assigned to 6 groups: GROUP 1 — negative control (n = 10); GROUP 2 — NTCD only (n = 13); GROUP 3 — Lactobacillus spp. only (n = 14); GROUP 4 — positive control (challenged with toxigenic C. difficile strain) (n = 35); GROUP 5 — NTCD and challenged with the toxigenic C. difficile strain (n = 34); and GROUP 6 — Lactobacillus spp. and challenged with the toxigenic C. difficile strain (n = 44). Piglets which received NTCD showed lower prevalence of toxin-positive feces, mesocolonic edema, and microscopic lesions compared with positive control piglets. Administration of Lactobacillus spp. did not reveal clear benefits. PMID:26834271

  6. Bacterial probiotics as an aid in the control of Clostridium difficile disease in neonatal pigs.

    PubMed

    Arruda, Paulo H E; Madson, Darin M; Ramirez, Alejandro; Rowe, Eric W; Songer, J Glenn

    2016-02-01

    Although Clostridium difficile infection (CDI) is a common disease in swine, there is a lack of prevention strategies. The objectives of this study were to evaluate: i) the effectiveness of Lactobacillus spp. and ii) non-toxigenic C. difficile (NTCD) as prevention for the development of CDI in piglets. Cesarean-derived piglets (N = 150) were randomly assigned to 6 groups: GROUP 1 - negative control (n = 10); GROUP 2 - NTCD only (n = 13); GROUP 3 - Lactobacillus spp. only (n = 14); GROUP 4 - positive control (challenged with toxigenic C. difficile strain) (n = 35); GROUP 5 - NTCD and challenged with the toxigenic C. difficile strain (n = 34); and GROUP 6 - Lactobacillus spp. and challenged with the toxigenic C. difficile strain (n = 44). Piglets which received NTCD showed lower prevalence of toxin-positive feces, mesocolonic edema, and microscopic lesions compared with positive control piglets. Administration of Lactobacillus spp. did not reveal clear benefits.

  7. Rice WRKY45 plays important roles in fungal and bacterial disease resistance.

    PubMed

    Shimono, Masaki; Koga, Hironori; Akagi, Aya; Hayashi, Nagao; Goto, Shingo; Sawada, Miyuki; Kurihara, Takayuki; Matsushita, Akane; Sugano, Shoji; Jiang, Chang-Jie; Kaku, Hisatoshi; Inoue, Haruhiko; Takatsuji, Hiroshi

    2012-01-01

    Plant 'activators', such as benzothiadiazole (BTH), protect plants from various diseases by priming the plant salicylic acid (SA) signalling pathway. We have reported previously that a transcription factor identified in rice, WRKY45 (OsWRKY45), plays a pivotal role in BTH-induced disease resistance by mediating SA signalling. Here, we report further functional characterization of WRKY45. Different plant activators vary in their action points, either downstream (BTH and tiadinil) or upstream (probenazole) of SA. Rice resistance to Magnaporthe grisea, induced by both types of plant activator, was markedly reduced in WRKY45-knockdown (WRKY45-kd) rice, indicating a universal role for WRKY45 in chemical-induced resistance. Fungal invasion into rice cells was blocked at most attempted invasion sites (pre-invasive defence) in WRKY45-overexpressing (WRKY45-ox) rice. Hydrogen peroxide accumulated within the cell wall underneath invading fungus appressoria or between the cell wall and the cytoplasm, implying a possible role for H(2)O(2) in pre-invasive defence. Moreover, a hypersensitive reaction-like reaction was observed in rice cells, in which fungal growth was inhibited after invasion (post-invasive defence). The two levels of defence mechanism appear to correspond to Type I and II nonhost resistances. The leaf blast resistance of WRKY45-ox rice plants was much higher than that of other known blast-resistant varieties. WRKY45-ox plants also showed strong panicle blast resistance. BTH-induced resistance to Xanthomonas oryzae pv. oryzae was compromised in WRKY45-kd rice, whereas WRKY45-ox plants were highly resistant to this pathogen. However, WRKY45-ox plants were susceptible to Rhizoctonia solani. These results indicate the versatility and limitations of the application of this gene.

  8. Distinct roles of the pepper pathogen-induced membrane protein gene CaPIMP1 in bacterial disease resistance and oomycete disease susceptibility.

    PubMed

    Hong, Jeum Kyu; Choi, Du Seok; Kim, Sang Hee; Yi, Seung Yeon; Kim, Young Jin; Hwang, Byung Kook

    2008-08-01

    Plant integral membrane proteins have essential roles in diverse internal and external physiological processes as signal receptors or ion transporters. The pepper CaPIMP1 gene encoding a putative integral membrane protein with four transmembrane domains was isolated and functionally characterized from pepper leaves infected with the avirulent strain Xanthomonas campestris pv. vesicatoria (Xcv). CaPIMP1-green fluorescence protein (GFP) fusions localized to the plasma membrane in onion cells, as observed by confocal microscopy. CaPIMP1 was expressed in an organ-specific manner in healthy pepper plants. Infection with Xcv induced differential accumulation of CaPIMP1 transcripts in pepper leaf tissues during compatible and incompatible interactions. The function of CaPIMP1 was examined by using the virus-induced gene silencing technique in pepper plants and by overexpression in Arabidopsis. CaPIMP1-silenced pepper plants were highly susceptible to Xcv infection and expressed lower levels of the defense-related gene CaSAR82A. CaPIMP1 overexpression (CaPIMP1-OX) in transgenic Arabidopsis conferred enhanced resistance to P. syringae pv. tomato infection, accompanied by enhanced AtPDF1.2 gene expression. In contrast, CaPIMP1-OX plants were highly susceptible to the biotrophic oomycete Hyaloperonospora parasitica. Taken together, we propose that CaPIMP1 plays distinct roles in both bacterial disease resistance and oomycete disease susceptibility.

  9. 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

  10. 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.

  11. Diverse microbial communities in non-aerated compost teas suppress bacterial wilt.

    PubMed

    Mengesha, W K; Powell, S M; Evans, K J; Barry, K M

    2017-03-01

    Non-aerated compost teas (NCTs) are water extracts of composted organic materials and are used to suppress soil borne and foliar disease in many pathosystems. Greenhouse trials were used to test the effectiveness of NCTs to suppress potato bacterial wilt caused by Ralstonia solanacearum on plants grown in soils inoculated with a virulent isolate of the pathogen (biovar II). NCTs prepared from matured compost sources: agricultural waste (AWCT), vermicompost (VCT) and solid municipal waste (SMWCT) were evaluated at three initial application times (7 days before inoculation, at time of inoculation and 7 days after inoculation) prior to weekly applications, in a randomized complete-block design. AWCT applied initially at the time of inoculation resulted in the greatest disease suppression, with the disease severity index 2.5-fold less than the non-treated plants and the "area under the disease progress curve" (AUDPC) 3.2-fold less. VCT and SMWCT were less suppressive than AWCT regardless of initial application time. Next generation sequencing of the v4 region of 16S rRNA gene and the internal transcribed spacer region (ITS1) revealed that diversity and composition of the bacterial and fungal communities across the NCTs varied significantly. Dominant bacterial phyla such as Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, Verrucomicrobia, Chloroflexi, Planctomycetes, Acidobacteria, and a fungal phylum Ascomycota were detected in all NCTs. AWCT had optimum physico-chemical measurements with higher bacterial Shannon diversity indices (H) and fungal richness (S) than the other treatments. We conclude that bacterial wilt of potatoes grown in controlled conditions can be suppressed by a non-aerated compost tea with a high microbial diversity when applied at planting and weekly thereafter.

  12. 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

    2015-06-23

    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.

  13. 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

  14. 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

  15. 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

    Shapiro, Lori R; Salvaudon, Lucie; 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

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

    PubMed

    Liu, Sixin; Vallejo, Roger L; Palti, Yniv; Gao, Guangtu; Marancik, David P; Hernandez, Alvaro G; Wiens, Gregory D

    2015-01-01

    Bacterial cold water disease (BCWD) is one of the frequent causes of elevated mortality in salmonid aquaculture. Previously, we identified and validated microsatellites on chromosome Omy19 associated with QTL (quantitative trait loci) for BCWD resistance and spleen size in rainbow trout. Recently, SNPs (single nucleotide polymorphism) have become the markers of choice for genetic analyses in rainbow trout as they are highly abundant, cost-effective and are amenable for high throughput genotyping. The objective of this study was to identify SNP markers associated with BCWD resistance and spleen size using both genome-wide association studies (GWAS) and linkage-based QTL mapping approaches. A total of 298 offspring from the two half-sib families used in our previous study to validate the significant BCWD QTL on chromosome Omy19 were genotyped with RAD-seq (restriction-site-associated DNA sequencing), and 7,849 informative SNPs were identified. Based on GWAS, 18 SNPs associated with BCWD resistance and 20 SNPs associated with spleen size were identified. Linkage-based QTL mapping revealed three significant QTL for BCWD resistance. In addition to the previously validated dam-derived QTL on chromosome Omy19, two significant BCWD QTL derived from the sires were identified on chromosomes Omy8 and Omy25, respectively. A sire-derived significant QTL for spleen size on chromosome Omy2 was detected. The SNP markers reported in this study will facilitate fine mapping to identify positional candidate genes for BCWD resistance in rainbow trout.

  17. 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.

  18. 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

  19. [Protective immune response of guinea pigs against challenge with foot and mouth disease virus by immunization with foliar extracts from transgenic tomato plants expressing the FMDV structural protein VP1].

    PubMed

    Pan, Li; Zhang, Yong-Guang; Wang, Yong-Lu; Wang, Bao-Qin; Xie, Qing-Ge

    2006-10-01

    The plant constitutive expression vector pBin438/VP1 for VP1 gene of foot-and-mouth disease virus strain O/ China/99 was constructed. Mediated with Agrobacterium tumefaciens GV3101 harboring pBin438/VP1, VP1 gene was transferred into cotyledons of tomato. After selected by Kanamysin, sixty resistant lines were obtained. The integration and transcription of the VP1 gene in transformed plants was detected by PCR and RT-PCR. After being detected by sandwich-ELISA assays, about 40% transformed plants confirmed to express the recombinant protein. The leave extracts of two positive lines were respectively emulsified in Freund's adjuvant and guinea pigs were intramuscular inoculation at days 0, 15 and 30d. According to the sera antibody levels and the protection of the vaccinated guinea pigs against challenge with 100ID50 FMDV, probed into the immunogenicity of the target protein expressed in transgenic plants. Experimental results showed that the plant expression vector was successfully constructed. PCR and RT-PCR analyses confirmed VP1 gene was transformed into tomato plants and got expression at the transcription levels. The expressed VP1 protein of FMDV, which was identified by ELISA and Western blot, can be specifically recognized by polyclonal antibodies against FMDV. Indirect-ELISA antibody titers reached 1:64 twenty-one days after the third inoculation. In the challenge test, the protection against FMDV challenge in two groups was 80% and 40% respectively. The immunization test in guinea pigs indicated that the expression product of transgenic tomato plants had immunogenicity and could effectively induce the specific antibodies against FMDV.

  20. Potential of biosynthesized silver nanoparticles using Stenotrophomonas sp. BHU-S7 (MTCC 5978) for management of soil-borne and foliar phytopathogens

    PubMed Central

    Mishra, Sandhya; Singh, Braj Raj; Naqvi, Alim H.; Singh, H. B.

    2017-01-01

    Stenotrophomonas sp. is emerging as a popular microbe of global concern with various potential ecological roles. Biosynthesis of gold and silver nanoparticles (AgNPs) using this bacterial strain has shown promising applications in life sciences. However, there is no report on efficient agricultural applications of biosynthesized AgNPs using Stenotrophomonas sp. In this regard, successful biosynthesis of AgNPs using Stenotrophomonas sp. BHU-S7 (MTCC 5978) was monitored by Uv-visible spectrum showing surface plasmon resonance (SPR) peak at 440 nm. The biosynthesized AgNPs were spherical with an average mean size of ~12 nm. The antifungal efficacy of biosynthesized AgNPs against foliar and soil-borne phytopathogens was observed. The inhibitory impact of AgNPs (2, 4, 10 μg/ml) on conidial germination was recorded under in vitro conditions. Interestingly, sclerotia of Sclerotium rolfsii exposed to AgNPs failed to germinate on PDA medium and in soil system. Moreover, AgNPs treatment successfully managed collar rot of chickpea caused by S. rolfsii under greenhouse conditions. The reduced sclerotia germination, phenolic acids induction, altered lignification and H2O2 production was observed to be the probable mechanisms providing protection to chickpea against S. rolfsii. Our data revealed that AgNPs treated plants are better equipped to cope with pathogen challenge pointing towards their robust applications in plant disease management. PMID:28345581

  1. Foliar heavy metal uptake, toxicity and detoxification in plants: A comparison of foliar and root metal uptake.

    PubMed

    Shahid, Muhammad; Dumat, Camille; Khalid, Sana; Schreck, Eva; Xiong, Tiantian; Niazi, Nabeel Khan

    2017-03-05

    Anthropologic activities have transformed global biogeochemical cycling of heavy metals by emitting considerable quantities of these metals into the atmosphere from diverse sources. In spite of substantial and progressive developments in industrial processes and techniques to reduce environmental emissions, atmospheric contamination by toxic heavy metals and associated ecological and health risks are still newsworthy. Atmospheric heavy metals may be absorbed via foliar organs of plants after wet or dry deposition of atmospheric fallouts on plant canopy. Unlike root metal transfer, which has been largely studied, little is known about heavy metal uptake by plant leaves from the atmosphere. To the best of our understanding, significant research gaps exist regarding foliar heavy metal uptake. This is the first review regarding biogeochemical behaviour of heavy metals in atmosphere-plant system. The review summarizes the mechanisms involved in foliar heavy metal uptake, transfer, compartmentation, toxicity and in plant detoxification. We have described the biological and environmental factors that affect foliar uptake of heavy metals and compared the biogeochemical behaviour (uptake, translocation, compartmentation, toxicity and detoxification) of heavy metals for root and foliar uptake. The possible health risks associated with the consumption of heavy metal-laced food are also discussed.

  2. Foliar retention and leachability of submicron plutonium and americium particles

    SciTech Connect

    Cataldo, D.A.; Garland, T.R.; Wildung, R.E.

    1981-01-01

    Submicron particles of Pu and Am were aerosolized, deposited onto foliage of bush bean (Phaseolus vulgaris L.), and their subsequent retention and behavior determined. Particles having mass median diameters of <1 ..mu..m are not readily dislodged from leaf surfaces at wind speeds of approx. 400 m min/sup -1/. Under conditions of simulated rainfall, weathering half-times range from 164 to 1000 days, and are dependent on both particle size and initial solubility. The residence time of contaminants on foliar surfaces prior to leaching influences subsequent foliar retention and leachate characteristics. Foliar retention of particles ranges from 20 to 92% and is dependent on particle size of Pu- and Am-oxides, chemical form of Pu, and environmental conditions such as humidity, simulated rainfall, and acidity of the simulated rain.

  3. Soil-based systemic delivery and phyllosphere in vivo propagation of bacteriophages: Two possible strategies for improving bacteriophage persistence for plant disease control.

    PubMed

    Iriarte, Fanny B; Obradović, Aleksa; Wernsing, Mine H; Jackson, Lee E; Balogh, Botond; Hong, Jason A; Momol, M Timur; Jones, Jeffrey B; Vallad, Gary E

    2012-10-01

    Soil-based root applications and attenuated bacterial strains were evaluated as means to enhance bacteriophage persistence on plants for bacterial disease control. In addition, the systemic nature of phage applied to tomato roots was also evaluated. Several experiments were conducted applying either single phages or phage mixtures specific for Ralstonia solanacearum, Xanthomonas perforans or X. euvesicatoria to soil surrounding tomato plants and measuring the persistence and translocation of the phages over time. In general, all phages persisted in the roots of treated plants and were detected in stems and leaves; although phage level varied and persistence in stems and leaves was at a much lower level compared with persistence in roots. Bacterial wilt control was typically best if the phage or phage mixtures were applied to the soil surrounding tomatoes at the time of inoculation, less effective if applied 3 days before inoculation, and ineffective if applied 3 days after inoculation. The use of an attenuated X. perforans strain was also evaluated to improve the persistence of phage populations on tomato leaf surfaces. In greenhouse and field experiments, foliar applications of an attenuated mutant X. perforans 91-118:∆OPGH strain prior to phage applications significantly improved phage persistence on tomato foliage compared with untreated tomato foliage. Both the soil-based bacteriophage delivery and the use of attenuated bacterial strains improved bacteriophage persistence on respective root and foliar tissues, with evidence of translocation with soil-based bacteriophage applications. Both strategies could lead to improved control of bacterial pathogens on plants.

  4. 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.

  5. Persistence of the bacterial pathogen Granulibacter bethesdensis in chronic granulomatous disease monocytes and macrophages lacking a functional NADPH oxidase.

    PubMed

    Chu, Jessica; Song, Helen H; Zarember, Kol A; Mills, Teresa A; Gallin, John I

    2013-09-15

    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 nonoxidative killing mechanisms. Although 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 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 d) 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, most likely relating to the persistence of this microorganism in infected CGD patients.

  6. 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

  7. First Report of Foliar Blight on Dendropanax morbifera Caused by Alternaria panax.

    PubMed

    Deng, Jian Xin; Kim, Chang Sun; Oh, Eun Sung; Yu, Seung Hun

    2010-12-01

    Leaf spot and blight disease was observed on two-year-old seedlings of Dendropanax morbifera (Korean name: Hwangchil tree) during July of 2008 in Jindo Island, Korea. Symptoms included yellow-brown to dark brown irregularly enlarged spots frequently located along the veins of leaves. The lesions were often surrounded by chlorotic haloes. Severe leaf blight and subsequent defoliation occurred when conditions favored disease outbreak. The causal organism of the disease was identified as Alternaria panax based on morphological characteristics and sequence analysis of the internal transcribed spacer region of rDNA. A. panax isolates induced leaf spots and blight symptoms not only on D. morbifera but also on the other members of Araliaceae tested. This is the first report of foliar blight caused by A. panax on D. morbifera.

  8. Evaluation of performance of bacterial culture of feces and serum ELISA across stages of Johne's disease in cattle using a Bayesian latent class model.

    PubMed

    Espejo, L A; Zagmutt, F J; Groenendaal, H; Muñoz-Zanzi, C; Wells, S J

    2015-11-01

    The objective of this study was to evaluate the performance of bacterial culture of feces and serum ELISA to correctly identify cows with Mycobacterium avium ssp. paratuberculosis (MAP) at heavy, light, and non-fecal-shedding levels. A total of 29,785 parallel test results from bacterial culture of feces and serum ELISA were collected from 17 dairy herds in Minnesota, Pennsylvania, and Colorado. Samples were obtained from adult cows from dairy herds enrolled for up to 10 yr in the National Johne's Disease Demonstration Herd Project. A Bayesian latent class model was fitted to estimate the probabilities that bacterial culture of feces (using 72-h sedimentation or 30-min centrifugation methods) and serum ELISA results correctly identified cows as high positive, low positive, or negative given that cows were heavy, light, and non-shedders, respectively. The model assumed that no gold standard test was available and conditional independency existed between diagnostic tests. The estimated conditional probabilities that bacterial culture of feces correctly identified heavy shedders, light shedders, and non-shedders were 70.9, 32.0, and 98.5%, respectively. The same values for the serum ELISA were 60.6, 18.7, and 99.5%, respectively. Differences in diagnostic test performance were observed among states. These results improve the interpretation of results from bacterial culture of feces and serum ELISA for detection of MAP and MAP antibody (respectively), which can support on-farm infection control decisions and can be used to evaluate disease-testing strategies, taking into account the accuracy of these tests.

  9. 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

  10. Foliar ozone injury and gas exchange among black cherry genotypes

    SciTech Connect

    Kouterick, K.B.; Skelly, J.M.; Fredericksen, T.S.; Kolb, T.E.; Savage, J.E.; Snyder, K.R. )

    1994-06-01

    The effect of differing ozone exposures on seedlings of black cherry genotypes was investigated in northcentral Pennsylvania. Ozone exclusion treatments were administrated to half-sib families R12 and MO-7, and wild-type (WT) grown in open-top chambers. Over the 1993 growing season, left gas exchange and stem volume were related to percentage of foliar ozone injury observed as adaxial stipple. Ozone symptoms decreased significantly with increasing ozone filtration. R12 exhibited the most severe foliar injury, while WT seedlings showed slightly less symptoms. MO-7 had the least amount of foliar injury. No clear trends in stomatal conductance or net photosynthesis were observed until August. During August, foliar injury was positively related to stomatal conductance. Stomatal conductance values were greatest in R12, followed by WT and MO-7. Photosynthesis followed the same pattern at stomatal conductance. Dark respiration rates were variable across treatments for the entire growing season. Differing ozone exposures did not affect stem volume, but stem volume of seedlings of all families in the open plot were significantly lower than seedlings within chambers. Overall, R12 had higher stem volume than MO-7 and WT seedlings.

  11. 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...

  12. From plant surface to plant metabolism: the uncertain fate of foliar-applied nutrients

    PubMed Central

    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

  13. 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.

  14. 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

  15. 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

  16. Biological control of bacterial speck of tomato under field conditions at several locations in north america.

    PubMed

    Wilson, M; Campbell, H L; Ji, P; Jones, J B; Cuppels, D A

    2002-12-01

    ABSTRACT Bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, continues to be a problem for tomato growers worldwide. A collection of nonpathogenic bacteria from tomato leaves plus P. syringae strains TLP2 and Cit7, P. fluorescens strain A506, and P. syringae pv. tomato DC3000 hrp mutants were examined in a greenhouse bioassay for the ability to reduce foliar bacterial speck disease severity. While several of these strains significantly reduced disease severity, P. syringae Cit7 was the most effective, providing a mean level of disease reduction of 78% under greenhouse conditions. The P. syringae pv. tomato DC3000 hrpA, hrpH, and hrpS mutants also significantly reduced speck severity under greenhouse conditions. The strains with the greatest efficacy under greenhouse conditions were tested for the ability to reduce bacterial speck under field conditions at locations in Alabama, Florida, and Ontario, Canada. P. syringae Cit7 was the most effective strain, providing a mean level of disease reduction of 28% over 10 different field experiments. P. fluorescens A506, which is commercially available as Blight-Ban A506, provided a mean level of disease reduction of 18% over nine different field experiments. While neither P. syringae Cit7 nor P. fluorescens A506 can be integrated with copper bactericides due to their copper sensitivity, there exist some potential for integrating these biological control agents with "plant activators", including Actigard. Of the P. syringae pv. tomato DC3000 hrp mutants tested, only the hrpS mutant reduced speck severity significantly under field conditions.

  17. [Influence of foliar dust on crop reflectance spectrum and nitrogen monitoring].

    PubMed

    Wang, Tao; Liu, Yang; Wu, Hai-Yun; Zuo, Yue-Ming

    2012-07-01

    More researches were carried out to investigate the application of spectral technology on crop nutrition diagnosis. However, the complex conditions in the field results in the uncertainty of spectrum. In this paper, the influence of foliar dust on spectral of the crop beside the nation road was studied, the differences of the raw spectral reflectance and first derivative spectral reflectance between the foliar with dust and the foliar washed with deionised water were analyzed, nitrogen prediction models were built on the disturbance of foliar dust. Result showed that the dust foliar spectral reflectance increased in the visible light (350-720 nm) and shortwave infrared (SWIR) (1 360-2 500 nm) regions whereas the spectral reflectance in the near infrared (NIR) (720-1 360 nm) wavelength regions decreased. There were no change rules for blue edge position, yellow edge position, red edge position, blue edge slope and yellow edge slope on the effect of foliar dust, but red edge slope, blue edge area, yellow edge area, red edge area decreased. Determinate coefficient (R2) of nitrogen prediction models reduced in the condition of foliar dust. The primary research work about the condition of foliar dust was studied which helps to provide foundation for evaluating effect of foliar dust and proposing foliar dust modification model in the future.

  18. 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...

  19. Acute immunological responses to a combined viral-bacterial respiratory disease challenge in feedlot heifers supplemented with yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two treatments were evaluated in commercial feedlot heifers to determine the effects of a yeast supplement on immune responses to a combined viral-bacterial respiratory challenge. Thirty-two beef heifers (325 +/- 19.2 kg BW) were selected and randomly assigned to one of two treatments, and fed for 3...

  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.

  1. Effects of foliar applied nickel on tomato plants. [Lycopersicon esculentum

    SciTech Connect

    Cash, R.C.; Leone, I.A.

    1987-01-01

    Shoot-applied nickel (Ni) treatments produced symptomatology, foliar Ni accumulation, and cytological changes in tomato (Lycopersicon esculentum Mill.) similar to those caused by treatments with root-applied nickel (Ni). Leaf damage resulting from 100 ..mu..g/ml foliar Ni-treatments consisted of interveinal chlorosis and spotting necrosis which appeared histologically as tissue collapse, cell clumping, and chloroplast disintegration. Shoot-treated plants accumulated more Ni in leaves than in roots; whereas the reverse was true in root-treated plants. Interference with root-to-shoot manganese translocation was attributed to attenuated vascular tissue and phloem blockage. Evidence of reduced nutrient transport and inhibited meristem activity due to Ni toxicity presents a potential for crop damage from excessive Ni in the atmosphere as well as in the soil environment.

  2. Bacillus thuringiensis suppresses bacterial wilt disease caused by Ralstonia solanacearum with systemic induction of defense-related gene expression in tomato.

    PubMed

    Hyakumachi, Mitsuro; Nishimura, Mitsuyoshi; Arakawa, Tatsuyuki; Asano, Shinichiro; Yoshida, Shigenobu; Tsushima, Seiya; Takahashi, Hideki

    2013-01-01

    Bacillus thuringiensis is a naturally abundant Gram-positive bacterium and a well-known, effective bio-insecticide. Recently, B. thuringiensis has attracted considerable attention as a potential biological control agent for the suppression of plant diseases. In this study, the bacterial wilt disease-suppressing activity of B. thuringiensis was examined in tomato plants. Treatment of tomato roots with B. thuringiensis culture followed by challenge inoculation with Ralstonia solanacearum suppressed the development of wilt symptoms to less than one third of the control. This disease suppression in tomato plants was reproduced by pretreating their roots with a cell-free filtrate (CF) that had been fractionated from B. thuringiensis culture by centrifugation and filtration. In tomato plants challenge-inoculated with R. solanacearum after pretreatment with CF, the growth of R. solanacearum in stem tissues clearly decreased, and expression of defense-related genes such as PR-1, acidic chitinase, and β-1,3-glucanase was induced in stem and leaf tissues. Furthermore, the stem tissues of tomato plants with their roots were pretreated with CF exhibited resistance against direct inoculation with R. solanacearum. Taken together, these results suggest that treatment of tomato roots with the CF of B. thuringiensis systemically suppresses bacterial wilt through systemic activation of the plant defense system.

  3. 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.

  4. Bacterially-Associated Transcriptional Remodelling in a Distinct Genomic Subtype of Colorectal Cancer Provides a Plausible Molecular Basis for Disease Development

    PubMed Central

    Goosen, Ryan W.

    2016-01-01

    The relevance of specific microbial colonisation to colorectal cancer (CRC) disease pathogenesis is increasingly recognised, but our understanding of possible underlying molecular mechanisms that may link colonisation to disease in vivo remains limited. Here, we investigate the relationships between the most commonly studied CRC-associated bacteria (Enterotoxigenic Bacteroides fragilis, pks+ Escherichia coli, Fusobacterium spp., afaC+ E. coli, Enterococcus faecalis & Enteropathogenic E. coli) and altered transcriptomic and methylation profiles of CRC patients, in order to gain insight into the potential contribution of these bacteria in the aetiopathogenesis of CRC. We show that colonisation by E. faecalis and high levels of Fusobacterium is associated with a specific transcriptomic subtype of CRC that is characterised by CpG island methylation, microsatellite instability and a significant increase in inflammatory and DNA damage pathways. Analysis of the significant, bacterially-associated changes in host gene expression, both at the level of individual genes as well as pathways, revealed a transcriptional remodeling that provides a plausible mechanistic link between specific bacterial colonisation and colorectal cancer disease development and progression in this subtype; these included upregulation of REG3A, REG1A and REG1P in the case of high-level colonization by Fusobacterium, and CXCL10 and BMI1 in the case of colonisation by E. faecalis. The enrichment of both E. faecalis and Fusobacterium in this CRC subtype suggests that polymicrobial colonisation of the colonic epithelium may well be an important aspect of colonic tumourigenesis. PMID:27846243

  5. 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

  6. Foliar uptake of fog in coastal California shrub species.

    PubMed

    Emery, Nathan C

    2016-11-01

    Understanding plant water uptake is important in ecosystems that experience periodic drought. In many Mediterranean-type climates like coastal California, plants are subject to significant drought and wildfire disturbance. During the dry summer months, coastal shrub species are often exposed to leaf wetting from overnight fog events. This study sought to determine whether foliar uptake of fog occurs in shrub species and how this uptake affects physiology and fuel condition. In a controlled greenhouse experiment, dominant California shrub species were exposed to isotopically labeled fog water and plant responses were measured. Potted plants were covered at the base to prevent root uptake. The deuterium label was detected in the leaves of four out of five species and in the stems of two of the species. While there was a minimal effect of foliar water uptake on live fuel moisture, several species had lower xylem tension and greater photosynthetic rates after overnight fog treatments, especially Salvia leucophylla. Coastal fog may provide a moisture source for many species during the summer drought, but the utilization of this water source may vary based on foliar morphology, phenology and plant water balance. From this study, it appears that drought-deciduous species (Artemisia californica and Salvia leucophylla) benefit more from overnight fog events than evergreen species (Adenostoma fasciculatum, Baccharis pilularis and Ceanothus megacarpus). This differential response to fog exposure among California shrub species may affect species distributions and physiological tolerances under future climate scenarios.

  7. 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.

  8. Prevalence of bacterial species in cats with clinical signs of lower urinary tract disease: recognition of Staphylococcus felis as a possible feline urinary tract pathogen.

    PubMed

    Litster, Annette; Moss, Susan M; Honnery, Mary; Rees, Bob; Trott, Darren J

    2007-03-31

    This study investigated the prevalence of bacterial pathogens of the urinary tract in Australian cats. Urine was collected by cystocentesis and subjected to urinalysis, bacterial culture and susceptibility testing. A total of 126 isolates were obtained from 107 culture-positive cats. Escherichia coli was most commonly isolated (37.3% of isolates) with the majority of isolates showing susceptibility to the 14 antimicrobials tested. Just over a quarter of isolates (27.0%) were Enterococcus faecalis, which showed resistance to cephalosporins and clindamycin. Staphylococcus felis, a previously unreported feline urinary tract pathogen which was susceptible to all antimicrobial agents tested, comprised 19.8% of the isolates. S. felis was significantly associated with urine that had a higher specific gravity (p=0.011) and pH (p=0.006) and was more likely to contain crystals (p=0.002) than urine from which other bacterial species were isolated. This is the first published study that associates the isolation of S. felis with clinical signs of lower urinary tract disease in cats.

  9. Overexpression of MoSM1, encoding for an immunity-inducing protein from Magnaporthe oryzae, in rice confers broad-spectrum resistance against fungal and bacterial diseases

    PubMed Central

    Hong, Yongbo; Yang, Yayun; Zhang, Huijuan; Huang, Lei; Li, Dayong; Song, Fengming

    2017-01-01

    Potential of MoSM1, encoding for a cerato-platanin protein from Magnaporthe oryzae, in improvement of rice disease resistance was examined. Transient expression of MoSM1 in rice leaves initiated hypersensitive response and upregulated expression of defense genes. When transiently expressed in tobacco leaves, MoSM1 targeted to plasma membrane. The MoSM1-overexpressing (MoSM1-OE) transgenic rice lines showed an improved resistance, as revealed by the reduced disease severity and decreased in planta pathogen growth, against 2 strains belonging to two different races of M. oryzae, causing blast disease, and against 2 strains of Xanthomonas oryzae pv. oryzae, causing bacterial leaf blight disease. However, no alteration in resistance to sheath blight disease was observed in MoSM1-OE lines. The MoSM1-OE plants contained elevated levels of salicylic acid (SA) and jasmonic acid (JA) and constitutively activated the expression of SA and JA signaling-related regulatory and defense genes. Furthermore, the MoSM1-OE plants had no effect on drought and salt stress tolerance and on grain yield. We conclude that MoSM1 confers a broad-spectrum resistance against different pathogens through modulating SA- and JA-mediated signaling pathways without any penalty on abiotic stress tolerance and grain yield, providing a promising potential for application of MoSM1 in improvement of disease resistance in crops. PMID:28106116

  10. Overexpression of MoSM1, encoding for an immunity-inducing protein from Magnaporthe oryzae, in rice confers broad-spectrum resistance against fungal and bacterial diseases.

    PubMed

    Hong, Yongbo; Yang, Yayun; Zhang, Huijuan; Huang, Lei; Li, Dayong; Song, Fengming

    2017-01-20

    Potential of MoSM1, encoding for a cerato-platanin protein from Magnaporthe oryzae, in improvement of rice disease resistance was examined. Transient expression of MoSM1 in rice leaves initiated hypersensitive response and upregulated expression of defense genes. When transiently expressed in tobacco leaves, MoSM1 targeted to plasma membrane. The MoSM1-overexpressing (MoSM1-OE) transgenic rice lines showed an improved resistance, as revealed by the reduced disease severity and decreased in planta pathogen growth, against 2 strains belonging to two different races of M. oryzae, causing blast disease, and against 2 strains of Xanthomonas oryzae pv. oryzae, causing bacterial leaf blight disease. However, no alteration in resistance to sheath blight disease was observed in MoSM1-OE lines. The MoSM1-OE plants contained elevated levels of salicylic acid (SA) and jasmonic acid (JA) and constitutively activated the expression of SA and JA signaling-related regulatory and defense genes. Furthermore, the MoSM1-OE plants had no effect on drought and salt stress tolerance and on grain yield. We conclude that MoSM1 confers a broad-spectrum resistance against different pathogens through modulating SA- and JA-mediated signaling pathways without any penalty on abiotic stress tolerance and grain yield, providing a promising potential for application of MoSM1 in improvement of disease resistance in crops.

  11. Deep 16S rRNA Pyrosequencing Reveals a Bacterial Community Associated with Banana Fusarium Wilt Disease Suppression Induced by Bio-Organic Fertilizer Application

    PubMed Central

    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

  12. 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.

  13. 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.

  14. Oral Manifestations of Tropical Infectious Diseases of Central and South America. Part II. Bacterial and Mycotic Infections.

    DTIC Science & Technology

    1979-05-24

    characteristic facial deformity called “gangosa” results from destruc- tive involvement of the maxillary nasal processes and hard palate and • heals...frequently on the maxillary incisive papi lla , lips , tongue, soft palate , uvul a, and glossopharyngeal arches.’2’2° The sequelae of ulceration , necrosis...and myco- bacterial pulp necrosis. 13 Dental invo l vement is most common in the maxillary anterior teeth. In addition to periphera l nerve

  15. Bacterial proteases in disease - role in intracellular survival, evasion of coagulation/ fibrinolysis innate defenses, toxicoses and viral infections.

    PubMed

    Dubin, Grzegorz; Koziel, Joanna; Pyrc, Krzysztof; Wladyka, Benedykt; Potempa, Jan

    2013-01-01

    Pathogenic bacteria have evolved multiple mechanisms aimed to evade host defenses. This review summarizes selected examples of how bacteria utilize proteolytic enzymes to efficiently establish and spread infection systemically. First, the role of proteases in intracellular survival and persistence - the primary means used by bacteria to endure phagocytosis and/or avoid the vigilance of the immune system - is discussed. Second, it is demonstrated how some bacteria escape entanglement in fibrin(ogen) meshes, by inducing their proteolytic dissolution while other species modify the proteolytic cascade of mesh formation to divert this important innate immune defense for their own benefit. Third, bacterial proteolytic toxins are introduced, which allow microorganisms to exert and take advantage of systemic effects already during primary, localized infection. Finally, it is discussed how viruses utilize bacterial proteases by taking advantage of concurrent infection, and how pathogens may even mutually benefit from the joint presence of other pathogens. The reviewed adaptations are often essential for pathogen survival in the hostile environment of a host organism. As such, the potential benefits of pharmacological interference in relevant pathways for the struggle against bacterial pathogens are also discussed.

  16. Foliar bacteria and soil fertility mediate seedling performance: a new and cryptic dimension of niche differentiation.

    PubMed

    Griffin, Eric A; Traw, M Brian; Morin, Peter J; Pruitt, Jonathan N; Wright, S Joseph; Carson, Walter P

    2016-11-01

    The phyllosphere (comprising the leaf surface and interior) is one of the world's largest microbial habitats and is host to an abundant and diverse array of bacteria. Nonetheless, the degree to which bacterial communities are benign, harmful, or beneficial to plants in situ is unknown. We tested the hypothesis that the net effect of reducing bacterial abundance and diversity would vary substantially among host species (from harmful to beneficial) and this would be strongly mediated by soil resource availability. To test this, we monitored tree seedling growth responses to commercial antibiotics among replicated resource supply treatments (N, P, K) in a tropical forest in Panama for 29 months. We applied either antibiotics or control water to replicated seedlings of five common tree species (Alseis blackiana, Desmopsis panamensis, Heisteria concinna, Sorocea affinis, and Tetragastris panamensis). These antibiotic treatments significantly reduced both the abundance and diversity of bacteria epiphytically as well as endophytically. Overall, the effect of antibiotics on performance was highly host specific. Applying antibiotics increased growth for three species by as much as 49% (Alseis, Heisteria, and Tetragastris), decreased growth for a fourth species by nearly 20% (Sorocea), and had no impact on a fifth species (Desmopsis). Perhaps more importantly, the degree to which foliar bacteria were harmful or not varied with soil resource supply. Specifically, applying antibiotics had no effect when potassium was added but increased growth rate by almost 40% in the absence of potassium. Alternatively, phosphorus enrichment caused the effect of bacteria to switch from being primarily beneficial to harmful or vice versa, but this depended entirely on the presence or absence of nitrogen enrichment (i.e., important and significant interactions). Our results are the first to demonstrate that the net effect of reducing the abundance and diversity of bacteria can have very

  17. 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

  18. [Diagnosis of bacterial vaginosis].

    PubMed

    Djukić, Slobodanka; Ćirković, Ivana; Arsić, Biljana; Garalejić, Eliana

    2013-01-01

    Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2-producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent's scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up-to-date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short-term and long-term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  19. Foliar and ecosystem respiration in an old-growth tropical rain forest.

    PubMed

    Cavaleri, Molly A; Oberbauer, Steven F; Ryan, Michael G

    2008-04-01

    Foliar respiration is a major component of ecosystem respiration, yet extrapolations are often uncertain in tropical forests because of indirect estimates of leaf area index (LAI). A portable tower was used to directly measure LAI and night-time foliar respiration from 52 vertical transects throughout an old-growth tropical rain forest in Costa Rica. In this study, we (1) explored the effects of structural, functional and environmental variables on foliar respiration; (2) extrapolated foliar respiration to the ecosystem; and (3) estimated ecosystem respiration. Foliar respiration temperature response was constant within plant functional group, and foliar morphology drove much of the within-canopy variability in respiration and foliar nutrients. Foliar respiration per unit ground area was 3.5 +/- 0.2 micromol CO2 m(-2) s(-1), and ecosystem respiration was 9.4 +/- 0.5 micromol CO2 m(-2) s(-1)[soil = 41%; foliage = 37%; woody = 14%; coarse woody debris (CWD) = 7%]. When modelled with El Niño Southern Oscillation (ENSO) year temperatures, foliar respiration was 9% greater than when modelled with temperatures from a normal year, which is in the range of carbon sink versus source behaviour for this forest. Our ecosystem respiration estimate from component fluxes was 33% greater than night-time net ecosystem exchange for the same forest, suggesting that studies reporting a large carbon sink for tropical rain forests based solely on eddy flux measurements may be in error.

  20. Are correlations among foliar traits in ferns consistent with those in the seed plants?

    PubMed

    Karst, Amanda L; Lechowicz, Martin J

    2007-01-01

    Broad-based studies of gymnosperms and angiosperms reveal consistent and functionally significant correlations among foliar traits such as leaf mass per area (LMA), maximum photosynthetic rate (A(area)), foliar nitrogen (N(area)), foliar chlorophyll (Chl) and leaf longevity. To assess the generality of these relationships, we studied 20 fern species growing in the understorey of a temperate deciduous forest. We found that foliar N(area) increases with LMA, and that foliar N(area) and A(area) are positively correlated with one another, as are foliar N(area) and Chl. The ferns in general have very low LMA compared with most seed plants; A(area), N(area) and Chl are below median values for seed plants but are not extreme. Species with overwintering fronds have significantly higher LMA than species with fronds that senesce at the end of the growing season, as well as a significantly higher C : N ratio in frond tissue and relatively high foliar N on an areal basis. Correlations among foliar traits associated with gas exchange in these forest understorey ferns are in accordance with patterns reported for seed plants, suggesting a high degree of functional constraint on the interrelationships among key elements in foliar design.

  1. Foliar phosphite application has minor phytotoxic impacts across a diverse range of conifers and woody angiosperms.

    PubMed

    Scott, Peter; Bader, Martin Karl-Friedrich; Williams, Nari Michelle

    2016-10-01

    Phytophthora plant pathogens cause tremendous damage in planted and natural systems worldwide. Phosphite is one of the only effective chemicals to control broad-scale Phytophthora disease. Little work has been done on the phytotoxic effects of phosphite application on plant communities especially in combination with plant physiological impacts. Here, we tested the phytotoxic impact of phosphite applied as foliar spray at 0, 12, 24 and 48 kg a.i. ha(-1) . Eighteen-month-old saplings of 13 conifer and angiosperm species native to New Zealand, and two exotic coniferous species were treated and the development of necrotic tissue and chlorophyll-a-fluorescence parameters (optimal quantum yield, Fv /Fm ; effective quantum yield of photosystem II, ΦPSII ) were assessed. In addition, stomatal conductance (gs ) was measured on a subset of six species. Significant necrosis assessed by digital image analysis occurred in only three species: in the lauraceous canopy tree Beilschmiedia tawa (8-14%) and the understory shrub Dodonaea viscosa (5-7%) across phosphite concentrations and solely at the highest concentration in the myrtaceous pioneer shrub Leptospermum scoparium (66%). In non-necrotic tissue, Fv /Fm , ΦPSII and gs remained unaffected by the phosphite treatment. Overall, our findings suggest minor phytotoxic effects resulting from foliar phosphite application across diverse taxa and regardless of concentration. This study supports the large-scale use of phosphite as a management tool to control plant diseases caused by Phytophthora pathogens in plantations and natural ecosystems. Long-term studies are required to ascertain potential ecological impacts of repeated phosphite applications.

  2. 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

  3. 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

  4. 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

  5. Wood and foliar respiration of tropical wet forest environment

    NASA Astrophysics Data System (ADS)

    Asao, S.; Bedoya Arrieta, R.; Ryan, M. G.

    2011-12-01

    Wood and foliar respiration from tropical forests constitute major components of ecosystem respiration that may control their productivity and carbon storage. However, few estimates on tropical forests vary greatly. Furthermore, the trees in these forests respire great amounts of carbon, but impacts of individual tree species on respiration is not well known. We examined wood and foliar respiration in this environment in relation to individual tree species. The objectives of this study were to: 1) identify how respiration rates relate to scaling variables for wood and foliage, 2) examine the effects of individual tree species on these relationships, 3) extrapolate the rates to the annual fluxes of the whole stands, and 4) determine if tree species differed in these fluxes. Established on an abandoned pasture in 1988 at La Selva Biological Station in Costa Rica, the monodominant stands contained four native species in a complete randomized block design. Respiration rates based on tissue surface area ranged among dominant tree species from 0.6 to 1.0 μg C m^-2 s^-1 for small diameter wood (<10cm), 1.0 to 1.8 μg C m^-2 s^-1 for large diameter wood, and 0.7 to 0.8 μg C m^-2 s^-1 for foliage. Understory species had similar wood respiration rates, but foliage respiration rates were about half of those for canopy leaves. Among surface area, volume, or biomass, respiration rates scaled best with surface area for wood with small diameter, volume or biomass for large diameter wood, and leaf area for foliage. These relationships differed slightly among tree species and between canopy trees and understory species. Foliar respiration rate was generally related to leaf nitrogen content, and this relationship differed among dominant tree species. Temperature response of foliar respiration also differed among tree species and canopy class. However, daily and annual temperature fluctuations had less than 3% effect on annual flux. Annual respiratory fluxes from wood and foliage

  6. Rice xa13 recessive resistance to bacterial blight is defeated by induction of the disease susceptibility gene Os-11N3.

    PubMed

    Antony, Ginny; Zhou, Junhui; Huang, Sheng; Li, Ting; Liu, Bo; White, Frank; Yang, Bing

    2010-11-01

    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.

  7. 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.

  8. Tick-borne bacterial, rickettsial, spirochetal, and protozoal infectious diseases in the United States: a comprehensive review.

    PubMed

    Amsden, Jarrett R; Warmack, Scott; Gubbins, Paul O

    2005-02-01

    Approximately 900 tick species exist worldwide, and they parasitize a variety of mammals, including humans; thus, ticks play a significant role in the transmission of infectious diseases. In the United States, tick-borne diseases are seasonally and geographically distributed; they typically occur during spring and summer but can occur throughout the year. Tick-borne diseases are endemic to a variety of geographic regions of the United States, depending on the species of tick commonly found in a specific locale. Specific tick-borne diseases are difficult to diagnose. Most patients have vague constitutional symptoms and nonspecific laboratory findings. Initially, serologic methods are of little benefit because they lack sensitivity early in the disease course. Therefore, a thorough history and physical examination are necessary for establishing a diagnosis. Antimicrobial regimens for tick-borne infections are poorly studied but well established. Tetracyclines and rifampin form the cornerstones of therapy for most tick-borne infections, but these agents may not be suitable for all patient populations. Therefore, no single agent can be chosen empirically to treat all tick-borne diseases. Because pharmacists are the most accessible health care providers, they are often asked how to treat tick-borne diseases. Thus, practitioners should be familiar with the ticks that inhabit their locale.

  9. Corymbia species and hybrids: chemical and physical foliar attributes and implications for herbivory.

    PubMed

    Nahrung, Helen F; Waugh, Rachel; Andrew Hayes, Richard

    2009-09-01

    Hybridization is an important biological phenomenon that can be used to understand the evolutionary process of speciation of plants and their associated pests and diseases. Interactions between hybrid plants and the herbivores of the parental taxa may be used to elucidate the various cues being used by the pests for host location or other processes. The chemical composition of plants, and their physical foliar attributes, including leaf thickness, trichome density, moisture content and specific leaf weight were compared between allopatric pure and commercial hybrid species of Corymbia, an important subtropical hardwood taxon. The leaf-eating beetle Paropsis atomaria, to which the pure taxa represented host (C. citriodora subsp. variegata) and non-host (C. torelliana) plants, was used to examine patterns of herbivory in relation to these traits. Hybrid physical foliar traits, chemical profiles, and field and laboratory beetle feeding preference, while showing some variability, were generally intermediate to those exhibited by parent taxa, thus suggesting an additive inheritance pattern. The hybrid susceptibility hypothesis was not supported by our field or laboratory studies, and there was no strong relationship between adult preference and larval performance. The most-preferred adult host was the sympatric taxon, although this species supported the lowest larval survival, while the hybrid produced significantly smaller pupae than the pure species. The results are discussed in relation to plant chemistry and physical characteristics. The findings suggest a chemical basis for host selection behavior and indicate that it may be possible to select for resistance to this insect pest in these commercially important hardwood trees.

  10. FOLIAR AND TUBER BLIGHT RESISTANCE IN A SOLANUM TUBEROSUM BREEDING LINES.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this research was to identify the genetic basis of foliar and tuber resistance to Phytophthora infestans in a potato breeding population developed from a cross between two tetraploid Solanum tuberosum lines, NY121 and NY115. The parent with high foliar resistance, NY121, was highly s...

  11. Management practices regulate the response of Moso bamboo foliar stoichiometry to nitrogen deposition

    NASA Astrophysics Data System (ADS)

    Song, Xinzhang; Gu, Honghao; Wang, Meng; Zhou, Guomo; Li, Quan

    2016-04-01

    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.

  12. Management practices regulate the response of Moso bamboo foliar stoichiometry to nitrogen deposition.

    PubMed

    Song, Xinzhang; Gu, Honghao; Wang, Meng; Zhou, Guomo; Li, Quan

    2016-04-07

    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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Characterization of foot-and-mouth disease virus gene products with antisera against bacterially synthesized fusion proteins

    SciTech Connect

    Strebel, K.; Beck, E.; Strohmaier, K.; Schaller, H.

    1986-03-01

    Defined segments of the cloned foot-and-mouth disease virus genome corresponding to all parts of the coding region were expressed in Escherichia coli as fusions to the N-terminal part of the MS2-polymerase gene under the control of the inducible lambdaPL promoter. All constructs yielded large amounts of proteins, which were purified and used to raise sequence-specific antisera in rabbits. These antisera were used to identify the corresponding viral gene products in /sup 35/S-labeled extracts from foot-and-mouth disease virus-infected BHK cells. This allowed us to locate unequivocally all mature foot-and-mouth disease virus gene products in the nucleotide sequence, to identify precursor-product relationships, and to detect several foot-and mouth disease virus gene products not previously identified in vivo or in vitro.

  18. Scaling uncertainties in estimating canopy foliar maintenance respiration for black spruce ecosystems in Alaska

    USGS Publications Warehouse

    Zhang, X.; McGuire, A.D.; Ruess, Roger 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

  19. A mutation within the leucine-rich repeat domain of the Arabidopsis disease resistance gene RPS5 partially suppresses multiple bacterial and downy mildew resistance genes.

    PubMed Central

    Warren, R F; Henk, A; Mowery, P; Holub, E; Innes, R W

    1998-01-01

    Recognition of pathogens by plants is mediated by several distinct families of functionally variable but structurally related disease resistance (R) genes. The largest family is defined by the presence of a putative nucleotide binding domain and 12 to 21 leucine-rich repeats (LRRs). The function of these LRRs has not been defined, but they are speculated to bind pathogen-derived ligands. We have isolated a mutation in the Arabidopsis RPS5 gene that indicates that the LRR region may interact with other plant proteins. The rps5-1 mutation causes a glutamate-to-lysine substitution in the third LRR and partially compromises the function of several R genes that confer bacterial and downy mildew resistance. The third LRR is relatively well conserved, and we speculate that it may interact with a signal transduction component shared by multiple R gene pathways. PMID:9724691

  20. 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.

  1. 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.

  2. Adhesive polydopamine coated avermectin microcapsules for prolonging foliar pesticide retention.

    PubMed

    Jia, Xin; Sheng, Wen-bo; Li, Wei; Tong, Yan-bin; Liu, Zhi-yong; Zhou, Feng

    2014-11-26

    In this work, we report a conceptual strategy for prolonging foliar pesticide retention by using an adhesive polydopamine (PDA) microcapsule to encapsulate avermectin, thereby minimizing its volatilization and improving its residence time on crop surfaces. Polydopamine coated avermectin (Av@PDA) microcapsules were prepared by emulsion interfacial-polymerization and characterized by Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, field-emission scanning electron microscope, and transmission electron microscopy. The in situ synthesis route confers Av@PDA microcapsules with remarkable avermectin loading ability of up to 66.5% (w/w). Kinetic study of avermectin release demonstrated that Av@PDA microcapsules exhibit sustained- and controlled-release properties. The adhesive property of Av@PDA microcapsules on different surfaces was verified by a comparative study between Av@PDA and passivated Av@SiO2 and Av@PDA@SiO2 capsules with silica shell. Moreover, PDA shell could effectively shield UV irradiation and so protect avermectin from photodegradation, making it more applicable for foliar spraying. Meanwhile, it is determinated that Av@PDA microcapsules have good mechanical stability property.

  3. Foliar sorption of emerging and priority contaminants under controlled conditions.

    PubMed

    Calderón-Preciado, Diana; Matamoros, Víctor; Biel, Carmen; Save, Robert; Bayona, Josep M

    2013-09-15

    Agricultural irrigation water contains a variety of contaminants that can be introduced into the food chain through intake by irrigated crops. This paper describes an experiment under controlled conditions designed to simulate sprinkle irrigation with polluted water at two different relative humidities (40 and 90%). Specifically, shed lettuce-heart leaves were spiked with an aqueous solution containing organic microcontaminants, including pharmaceuticals (ibuprofen, diclofenac, clofibric acid, and carbamazepine), fragrances (tonalide), biocides (triclosan), insecticides (lindane), herbicides (atrazine), phenolic estrogen (bisphenol A), and polycyclic aromatic hydrocarbons (phenanthrene and pyrene). Following an incubation period (48 h), the treated leaves were rinsed with water, and both the solution used to rinse them and the leaves themselves were independently analyzed to investigate the foliar sorption and uptake of the spiked organic contaminants through cuticle. The results showed that the foliar sorption of emerging and priority microcontaminants in leaves wetted by irrigation practices is related to their polarity (logD(ow)) and volatility (logk(H)), regardless of their compound class and the relative humidity. The results thus underscore the need to improve the quality of reclaimed water in crop irrigation, particularly when sprinkle irrigation is used.

  4. 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.

  5. 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.

  6. Molecular phylogeny, homology modeling, and molecular dynamics simulation of race-specific bacterial blight disease resistance protein (xa5) of rice: a comparative agriproteomics approach.

    PubMed

    Dehury, Budheswar; Sahu, Mousumi; Sarma, Kishore; Sahu, Jagajjit; Sen, Priyabrata; Modi, Mahendra Kumar; Sharma, Gauri Dutta; Choudhury, Manabendra Dutta; Barooah, Madhumita

    2013-08-01

    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.

  7. 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.

  8. 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...

  9. 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...

  10. 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

  11. Variability of a bacterial surface protein and disease expression in a possible mouse model of systemic Lyme borreliosis

    PubMed Central

    1994-01-01

    During persistent infection of scid mice with Borrelia turicatae, an agent of relapsing fever and neuroborreliosis, there was variation in the surface proteins the bacteria expressed and in disease manifestations over time. Two serotypes, A and B, were isolated from the mice, cloned by limiting dilution, and further characterized. The only discernible difference between the two variants was in the size of the major surface protein they expressed: serotype A had a variable major protein (Vmp) of 23,000, and serotype B had a Vmp of 20,000. When other scid mice were inoculated with clonal populations of A and B, the infections were similar with respect to onset and degree of spirochetemia, involvement of the eye and heart, and occurrence of a peripheral vestibular disorder. However, there were differences between the serotypes in other respects: (a) serotype B but not A caused reddened and significantly enlarged joints, markedly impaired performance on a walking bar, and severe arthritis by histologic examination; (b) serotype A but not B invaded the central nervous system during early infection; and (c) serotype A penetrated monolayers of human umbilical vein endothelial cells more readily than did serotype B. The combination of arthritis, myocarditis, and neurologic disease resembled human Lyme borreliosis. The findings indicate that differences in disease expression are determined by variable surface proteins of the bacterium and that scid mouse infections with B. turicatae provide a model for the study of the pathogenesis of Lyme borreliosis and other persistent spirochetal diseases. PMID:8294872

  12. 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.

  13. The combination of PRRS virus and bacterial endotoxin as a model for multifactorial respiratory disease in pigs.

    PubMed

    Van Gucht, Steven; Labarque, Geoffrey; Van Reeth, Kristien

    2004-12-08

    This paper reviews in vivo studies on the interaction between porcine reproductive and respiratory syndrome virus (PRRSV) and LPS performed in the authors' laboratory. The main aim was to develop a reproducible model to study the pathogenesis of PRRSV-induced multifactorial respiratory disease. The central hypothesis was that respiratory disease results from an overproduction of proinflammatory cytokines in the lungs. In a first series of studies, PRRSV was shown to be a poor inducer of TNF-alpha and IFN-alpha in the lungs, whereas IL-1 and the anti-inflammatory cytokine IL-10 were produced consistently during infection. We then set up a dual inoculation model in which pigs were inoculated intratracheally with PRRSV and 3-14 days later with LPS. PRRSV-infected pigs developed acute respiratory signs for 12-24h upon intratracheal LPS inoculation, in contrast to pigs inoculated with PRRSV or LPS only. Moreover, peak TNF-alpha, IL-1 and IL-6 titers were 10-100 times higher in PRRSV-LPS inoculated pigs than in the singly inoculated pigs and the cytokine overproduction was associated with disease. To further prove the role of proinflammatory cytokines, we studied the effect of pentoxifylline, a known inhibitor of TNF-alpha and IL-1, on PRRSV-LPS induced cytokine production and disease. The clinical effects of two non-steroidal anti-inflammatory drugs (NSAIDs), meloxicam and flunixin meglumine, were also examined. Pentoxifylline, but not the NSAIDs, significantly reduced fever and respiratory signs from 2 to 6h after LPS. The levels of TNF-alpha and IL-1 in the lungs of pentoxifylline-treated pigs were moderately reduced, but were still 26 and 3.5-fold higher than in pigs inoculated with PRRSV or LPS only. This indicates that pathways other than inhibition of cytokine production contributed to the clinical improvement. Finally, we studied a mechanism by which PRRSV may sensitize the lungs for LPS. We hypothesized that PRRSV would increase the amount of LPS receptor

  14. 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.

  15. Symptomatic Anti-Neutrophil Cytoplasmic Antibody-Positive Disease Complicating Subacute Bacterial Endocarditis: To Treat or Not to Treat?

    PubMed Central

    Konstantinov, Konstantin N.; Harris, Alexis A.; Hartshorne, Michael F.; Tzamaloukas, Antonios H.

    2012-01-01

    A 54-year-old man was diagnosed with Streptococcus mutans endocarditis of the mitral valve. Serological tests disclosed the presence of multiple autoantibodies including c-ANCA, anti-PR3 and anti-MPO. While the fever subsided with antibiotics, mental status and renal function deteriorated rapidly. Kidney biopsy revealed pauci-immune glomerulonephritis and acute eosinophilic interstitial nephritis. The abnormal clinical features improved rapidly after addition of corticosteroids and cyclophosphamide to the antibiotics. Immunosuppressive agents may be required in a fraction of the patients with infective endocarditis who develop ANCA and ANCA-mediated renal disease. Histological identification of the type of renal disease is imperative for the choice of the treatment. PMID:23197952

  16. Bacterial Tracheitis

    MedlinePlus

    ... as a complication of croup (see Croup ) or endotracheal intubation (insertion of a plastic breathing tube through the ... irregularities that distinguish bacterial tracheitis from croup. Treatment Endotracheal intubation Antibiotics With treatment, most children recover completely. Very ...

  17. Foliar fungal communities strongly differ between habitat patches in a landscape mosaic

    PubMed Central

    Robin, Cécile; Capdevielle, Xavier; Delière, Laurent; Vacher, Corinne

    2016-01-01

    Background Dispersal events between habitat patches in a landscape mosaic can structure ecological communities and influence the functioning of agrosystems. Here we investigated whether short-distance dispersal events between vineyard and forest patches shape foliar fungal communities. We hypothesized that these communities homogenize between habitats over the course of the growing season, particularly along habitat edges, because of aerial dispersal of spores. Methods We monitored the richness and composition of foliar and airborne fungal communities over the season, along transects perpendicular to edges between vineyard and forest patches, using Illumina sequencing of the Internal Transcribed Spacer 2 (ITS2) region. Results In contrast to our expectation, foliar fungal communities in vineyards and forest patches increasingly differentiate over the growing season, even along habitat edges. Moreover, the richness of foliar fungal communities in grapevine drastically decreased over the growing season, in contrast to that of forest trees. The composition of airborne communities did not differ between habitats. The composition of oak foliar fungal communities change between forest edge and centre. Discussion These results suggest that dispersal events between habitat patches are not major drivers of foliar fungal communities at the landscape scale. Selective pressures exerted in each habitat by the host plant, the microclimate and the agricultural practices play a greater role, and might account for the differentiation of foliar fugal communities between habitats. PMID:27833817

  18. Unusual long-chain N-acyl homoserine lactone production by and presence of quorum quenching activity in bacterial isolates from diseased tilapia fish.

    PubMed

    Chang, Chien-Yi; Koh, Chong-Lek; Sam, Choon-Kook; Chan, Xin-Yue; Yin, Wai Fong; Chan, Kok Gan

    2012-01-01

    Growth-dependent cell-cell communication termed quorum sensing is a key regulatory system in bacteria for controlling gene expression including virulence factors. In this study five potential bacterial pathogens including Bacillus sp. W2.2, Klebsiella sp. W4.2, Pseudomonas sp. W3 and W3.1 and Serratia sp. W2.3 were isolated from diseased Tilapia fish in Malaysia, supplied by the leading global fish supplier. Proteolytic activity assays confirmed that with the exception of Klebsiella sp. W4.2, all isolates showed distinct proteolytic activity. Furthermore Bacillus sp. W2.2 and Pseudomonas sp. strains W3 and W3.1 also displayed haemolytic activity. By using high resolution liquid chromatography mass spectrometry, we revealed the presence of unusually long-chain N-(3-oxohexadecanoyl)-homoserine lactone (3-oxo-C16-HSL) from Pseudomonas sp. W3.1 and N-dodecanoyl-homoserine lactone (C12-HSL) from Serratia sp. W2.3, respectively. Interestingly, Pseudomonas sp. W3.1 also produced a wide range of Pseudomonas quinolone signalling (PQS) molecules. Pseudomonas sp. W3 did not show any quorum sensing properties but possessed quorum quenching activity that inactivated AHLs. This study is the first documentation that shows unusual long-chain AHLs production in Serratia sp. and Pseudomonas sp. isolated from diseased fish and the latter also produce a wide range of PQS molecules.

  19. Unusual Long-Chain N-Acyl Homoserine Lactone Production by and Presence of Quorum Quenching Activity in Bacterial Isolates from Diseased Tilapia Fish

    PubMed Central

    Chang, Chien-Yi; Koh, Chong-Lek; Sam, Choon-Kook; Chan, Xin-Yue; Yin, Wai Fong; Chan, Kok Gan

    2012-01-01

    Growth-dependent cell-cell communication termed quorum sensing is a key regulatory system in bacteria for controlling gene expression including virulence factors. In this study five potential bacterial pathogens including Bacillus sp. W2.2, Klebsiella sp. W4.2, Pseudomonas sp. W3 and W3.1 and Serratia sp. W2.3 were isolated from diseased Tilapia fish in Malaysia, supplied by the leading global fish supplier. Proteolytic activity assays confirmed that with the exception of Klebsiella sp. W4.2, all isolates showed distinct proteolytic activity. Furthermore Bacillus sp. W2.2 and Pseudomonas sp. strains W3 and W3.1 also displayed haemolytic activity. By using high resolution liquid chromatography mass spectrometry, we revealed the presence of unusually long-chain N-(3-oxohexadecanoyl)-homoserine lactone (3-oxo-C16-HSL) from Pseudomonas sp. W3.1 and N-dodecanoyl-homoserine lactone (C12-HSL) from Serratia sp. W2.3, respectively. Interestingly, Pseudomonas sp. W3.1 also produced a wide range of Pseudomonas quinolone signalling (PQS) molecules. Pseudomonas sp. W3 did not show any quorum sensing properties but possessed quorum quenching activity that inactivated AHLs. This study is the first documentation that shows unusual long-chain AHLs production in Serratia sp. and Pseudomonas sp. isolated from diseased fish and the latter also produce a wide range of PQS molecules. PMID:22952864

  20. The Pto kinase conferring resistance to tomato bacterial speck disease interacts with proteins that bind a cis-element of pathogenesis-related genes.

    PubMed Central

    Zhou, J; Tang, X; Martin, G B

    1997-01-01

    In tomato, the Pto kinase confers resistance to bacterial speck disease by recognizing the expression of a corresponding avirulence gene, avrPto, in the pathogen Pseudomonas syringae pv. tomato. Using the yeast two-hybrid system, we have identified three genes, Pti4, Pti5 and Pti6, that encode proteins that physically interact with the Pto kinase. Pti4/5/6 each encode a protein with characteristics that are typical of transcription factors and are similar to the tobacco ethylene-responsive element-binding proteins (EREBPs). Using a gel mobility-shift assay, we demonstrate that, similarly to EREBPs, Pti4/5/6 specifically recognize and bind to a DNA sequence that is present in the promoter region of a large number of genes encoding 'pathogenesis-related' (PR) proteins. Expression of several PR genes and a tobacco EREBP gene is specifically enhanced upon Pto-avrPto recognition in tobacco. These observations establish a direct connection between a disease resistance gene and the specific activation of plant defense genes. PMID:9214637

  1. 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

  2. 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

  3. The bovine paranasal sinuses: Bacterial flora, epithelial expression of nitric oxide and potential role in the in-herd persistence of respiratory disease pathogens.

    PubMed

    Murray, Gerard M; O'Neill, Rónan G; Lee, Alison M; McElroy, Máire C; More, Simon J; Monagle, Aisling; Earley, Bernadette; Cassidy, Joseph P

    2017-01-01

    The bovine paranasal sinuses are a group of complex cavernous air-filled spaces, lined by respiratory epithelium, the exact function of which is unclear. While lesions affecting these sinuses are occasionally reported in cattle, their microbial flora has not been defined. Furthermore, given that the various bacterial and viral pathogens causing bovine respiratory disease (BRD) persist within herds, we speculated that the paranasal sinuses may serve as a refuge for such infectious agents. The paranasal sinuses of clinically normal cattle (n = 99) and of cattle submitted for post-mortem examination (PME: n = 34) were examined by microbial culture, PCR and serology to include bacterial and viral pathogens typically associated with BRD: Mycoplasma bovis, Histophilus somni, Mannheimia haemolytica and Pasteurella multocida, bovine respiratory syncytial virus (BRSV) and bovine parainfluenza-3 virus (BPIV-3). Overall, the paranasal sinuses were either predominantly sterile or did not contain detectable microbes (83.5%: 94.9% of clinically normal and 50.0% of cattle submitted for PME). Bacteria, including BRD causing pathogens, were identified in relatively small numbers of cattle (<10%). While serology indicated widespread exposure of both clinically normal and cattle submitted for PME to BPIV-3 and BRSV (seroprevalences of 91.6% and 84.7%, respectively), PCR identified BPIV-3 in only one animal. To further explore these findings we investigated the potential role of the antimicrobial molecule nitric oxide (NO) within paranasal sinus epithelium using immunohistochemistry. Expression of the enzyme responsible for NO synthesis, inducible nitric oxide synthase (iNOS), was detected to varying degrees in 76.5% of a sub-sample of animals suggesting production of this compound plays a similar protective role in the bovine sinus as it does in humans.

  4. The bovine paranasal sinuses: Bacterial flora, epithelial expression of nitric oxide and potential role in the in-herd persistence of respiratory disease pathogens

    PubMed Central

    O’Neill, Rónan G.; Lee, Alison M.; McElroy, Máire C.; More, Simon J.; Monagle, Aisling; Earley, Bernadette; Cassidy, Joseph P.

    2017-01-01

    The bovine paranasal sinuses are a group of complex cavernous air-filled spaces, lined by respiratory epithelium, the exact function of which is unclear. While lesions affecting these sinuses are occasionally reported in cattle, their microbial flora has not been defined. Furthermore, given that the various bacterial and viral pathogens causing bovine respiratory disease (BRD) persist within herds, we speculated that the paranasal sinuses may serve as a refuge for such infectious agents. The paranasal sinuses of clinically normal cattle (n = 99) and of cattle submitted for post-mortem examination (PME: n = 34) were examined by microbial culture, PCR and serology to include bacterial and viral pathogens typically associated with BRD: Mycoplasma bovis, Histophilus somni, Mannheimia haemolytica and Pasteurella multocida, bovine respiratory syncytial virus (BRSV) and bovine parainfluenza-3 virus (BPIV-3). Overall, the paranasal sinuses were either predominantly sterile or did not contain detectable microbes (83.5%: 94.9% of clinically normal and 50.0% of cattle submitted for PME). Bacteria, including BRD causing pathogens, were identified in relatively small numbers of cattle (<10%). While serology indicated widespread exposure of both clinically normal and cattle submitted for PME to BPIV-3 and BRSV (seroprevalences of 91.6% and 84.7%, respectively), PCR identified BPIV-3 in only one animal. To further explore these findings we investigated the potential role of the antimicrobial molecule nitric oxide (NO) within paranasal sinus epithelium using immunohistochemistry. Expression of the enzyme responsible for NO synthesis, inducible nitric oxide synthase (iNOS), was detected to varying degrees in 76.5% of a sub-sample of animals suggesting production of this compound plays a similar protective role in the bovine sinus as it does in humans. PMID:28282443

  5. Determination of bacterial aetiologic factor on tracheobronchial lavage in relation to clinical signs of bovine respiratory disease.

    PubMed

    França Dias de Oliveira, Bernardo Augusto; Carrillo Gaeta, Natália; Mendonça Ribeiro, Bruno Leonardo; Reyes Alemán, Mário Augusto; Miranda Marques, Lucas; Timenetsky, Jorge; Melville, Priscila Anne; Avansi Marques, Júlia; Marvulle, Valdecir; Gregory, Lilian

    2016-10-01

    This study aimed to determine the occurrence of Mannheimiahaemolytica, Pasteurella multocida and Mycoplasma spp., in relation to clinical signs of respiratory disease. Tracheobronchial lavage samples were collected from 96 (healthy and unhealthy) cattle in the State of São Paulo, Brazil. Mycoplasma spp. (12.5 %) and Pasteurellamultocida (15.50 %) were the most prevalent species. Bacillus sp., Staphylococcus sp., Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa and Klebsiella pneumoniae were also isolated. Mollicutes (70.83 %), Mycoplasmabovis (2.94 %) and Mycoplasma dispar (38.23 %) were identified using conventional PCR. Submassive sound on acoustic percussion of the thorax was associated with the absence of Mollicutes (P=0.025). Whistling (P=0.076) and coarse crackle (P=0.046) were associated with the absence of Mycoplasma dispar. Clear sound on acoustic percussion of the thorax was associated with the absence of Mycoplasmabovis (P=0.007). Coughing was associated with the presence of Pasteurellamultocida [P=0.035; confidence interval (CI), 1.12-26.89], but its absence was associated with mucopurulent (P=0.0215; CI, 1.55-34.5) and mucoid nasal discharge (P=0.068; CI, 19-28.5), submassive sound (P=0.031; CI, 1.23-75.5), fine crackle (P=0.058; CI, 1.23-20.1) and coarse crackle (P=0.046; CI, 2.38-70.8). The high prevalence of Pasteurella multocida and Mycoplasma spp. in unhealthy calves increases the importance of these micro-organisms in the pathogenesis of respiratory diseases. This study increases the information about the role of Mycoplasma dispar in respiratory diseases. Differences in some species in relation to clinical signs can be applied as a presumptive diagnosis.

  6. Foliar uptake of nitrogen oxides: A nitrogen source for forests

    SciTech Connect

    Hanson, P.J.; Taylor, G.E. Jr.; Gunderson, C.A. )

    1989-04-01

    Non-urban concentrations of nitrogen oxide gases are insufficient to directly impede plant growth processes, but foliar uptake of these gases may represent a significant N source. Measurements of NO{sub 2} and HNO{sub 3} vapor uptake by elements representative of a forest landscape (e.g. foliage, bark, forest floor) were conducted in an open gas exchange system. Under daylight conditions using a mean NO{sub 2} level of 33 ml l{sup {minus}1}, NO{sub 2} uptake by foliage of forest tree species ranged from 0.35 to 5.75 nmol m{sup {minus}2} s{sup {minus}1}. Uptake of NO{sub 2} by broadleaf species was greater than by conifers. Dry bark surfaces showed about half the conductance to NO{sub 2} than did plant shoots. Forest floor samples had a disproportionately high conductance to NO{sub 2} when compared to bark or foliage surfaces. At similar concentrations, uptake of HNO{sub 3} vapor exceeded that for NO{sub 2}. Foliar NO{sub 2} uptake, under stomatal control, was principally to leaf interiors, but HNO{sub 3} uptake occurred to leaf interiors and surfaces. Based on ambient NO{sub 2} concentrations and conductance data scaled to the forest canopy, NO{sub 2} deposition provides from 0.1 to 2.0 kg ha{sup {minus}1} y{sup {minus}1} of nitrogen to natural forests (0.1 to 3% of annual needs). Conversely, deposition to urban forests may supply >10% of a forest's annual need.

  7. [Relationship between antophyte foliar morphology and abiotic factors in the main rainforests of Eastern Cuba].

    PubMed

    Quesada, Eddy Martínez

    2009-01-01

    Relationship between antophyte foliar morphology and abiotic factors in the main rainforests of Eastern Cuba. The foliar morphology of representative antophytes in four rainforest types of Eastern Cuba was studied in relation to the main abiotic factors. Although there are several leaf types in these forests, the microphyll type is the most important among endemic species in the ophiolites complex and the Montane rainforest. At the Lowland rainforest (metamorphic complex) the mesophyll leaf was the most important. Most foliar epidermis had structures normally found in mesomorphic plants, but xeromorphic and higromorphic morphologies were also present.

  8. Effect of foliar feeding on nitrogen assimilation in alfalfa plants at insufficient molybdenum supply.

    PubMed

    Hristozkova, Marieta; Geneva, Maria; Stancheva, Ira

    2009-06-01

    The influence of foliar feeding on the nitrogen assimilation in alfalfa plants under conditions of Mo shortage was studied. It was established that foliar fertilization with 0.3% solution of Agroleaf® resulted in increase of nitrogen fixation and nitrogen assimilation in the absence of Mo. Insufficient molybdenum supply leads to significant reduction of plant Mo content and nitrogen-fixing activity, while stress induced amino acids as alanine, GABA, threonine, proline and serine increased repeatedly. The negative effect of Mo deficiency on the enzyme activities related to the primary nitrogen assimilation (NR, GS, GOGAT) and plant growth diminished due to the foliar absorbed nutrients.

  9. Choline, Its Potential Role in Nonalcoholic Fatty Liver Disease, and the Case for Human and Bacterial Genes12

    PubMed Central

    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

  10. 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.

  11. Inducible CYP2J2 and its product 11,12-EET promotes bacterial phagocytosis: a role for CYP2J2 deficiency in the pathogenesis of Crohn's disease?

    PubMed

    Bystrom, Jonas; Thomson, Scott J; Johansson, Jörgen; Edin, Matthew L; Zeldin, Darryl C; Gilroy, Derek W; Smith, Andrew M; Bishop-Bailey, David

    2013-01-01

    The epoxygenase CYP2J2 has an emerging role in inflammation and vascular biology. The role of CYP2J2 in phagocytosis is not known and its regulation in human inflammatory diseases is poorly understood. Here we investigated the role of CYP2J2 in bacterial phagocytosis and its expression in monocytes from healthy controls and Crohns disease patients. CYP2J2 is anti-inflammatory in human peripheral blood monocytes. Bacterial LPS induced CYP2J2 mRNA and protein. The CYP2J2 arachidonic acid products 11,12-EET and 14,15-EET inhibited LPS induced TNFα release. THP-1 monocytes were transformed into macrophages by 48h incubation with phorbol 12-myristate 13-acetate. Epoxygenase inhibition using a non-selective inhibitor SKF525A or a selective CYP2J2 inhibitor Compound 4, inhibited E. coli particle phagocytosis, which could be specifically reversed by 11,12-EET. Moreover, epoxygenase inhibition reduced the expression of phagocytosis receptors CD11b and CD68. CD11b also mediates L. monocytogenes phagocytosis. Similar, to E. coli bioparticle phagocytosis, epoxygenase inhibition also reduced intracellular levels of L. monocytogenes, which could be reversed by co-incubation with 11,12-EET. Disrupted bacterial clearance is a hallmark of Crohn's disease. Unlike macrophages from control donors, macrophages from Crohn's disease patients showed no induction of CYP2J2 in response to E. coli. These results demonstrate that CYP2J2 mediates bacterial phagocytosis in macrophages, and implicates a defect in the CYP2J2 pathway may regulate bacterial clearance in Crohn's disease.

  12. Protective efficacy of a recombinant bacterial artificial chromosome clone of a very virulent Marek's disease virus containing a reticuloendotheliosis virus long terminal repeat.

    PubMed

    Mays, Jody K; Black-Pyrkosz, Alexis; Spatz, Stephen; Fadly, Aly M; Dunn, John R

    2016-12-01

    Marek's disease virus (MDV), an alphaherpesvirus, causes Marek's disease (MD), a lymphoproliferative disease in poultry characterized by T-cell lymphomas, nerve lesions, and mortality. Vaccination is used worldwide to control MD, but increasingly virulent field strains can overcome this protection, driving a need to create new vaccines. Previous studies revealed that insertion of reticuloendotheliosis virus (REV) long terminal repeat (LTR) into a bacterial artificial chromosome (BAC) clone of a very virulent strain of MDV, Md5, rendered the resultant recombinant virus, rMd5 REV-LTR BAC, fully attenuated in maternal antibody positive (Mab+) chickens at passage 40. In the current study, the protective efficacy of rMd5 REV-LTR BAC was evaluated. First, passage 70 was identified as being fully attenuated in maternal antibody negative chickens and chosen as the optimal passage level for use in protective efficacy studies. Second, three protective efficacy trials were conducted comparing the rMd5 REV-LTR p70 BAC to the CVI988/Rispens vaccine. Groups of Mab+ and Mab- 15I5 × 71 chickens were vaccinated in ovo at 18 days of embryonation or intra-abdominally at day of hatch, and challenged at 5 days post-hatch with the vv+MDV strain 686. Vaccination at day of hatch and in ovo with rMd5 REV-LTR p70 BAC protected chickens against MDV-induced bursa and thymic atrophy, but did not provide the same level of protection against MD tumours as that afforded by the commercial vaccine, CVI988/Rispens.

  13. Population Genomic Analysis of a Bacterial Plant Pathogen: Novel Insight into the Origin of Pierce's Disease of Grapevine in the U.S.

    PubMed Central

    Nunney, Leonard; Yuan, Xiaoli; Bromley, Robin; Hartung, John; Montero-Astúa, Mauricio; Moreira, Lisela; Ortiz, Beatriz; Stouthamer, Richard

    2010-01-01

    Invasive diseases present an increasing problem worldwide; however, genomic techniques are now available to investigate the timing and geographical origin of such introductions. We employed genomic techniques to demonstrate that the bacterial pathogen causing Pierce's disease of grapevine (PD) is not native to the US as previously assumed, but descended from a single genotype introduced from Central America. PD has posed a serious threat to the US wine industry ever since its first outbreak in Anaheim, California in the 1880s and continues to inhibit grape cultivation in a large area of the country. It is caused by infection of xylem vessels by the bacterium Xylella fastidiosa subsp. fastidiosa, a genetically distinct subspecies at least 15,000 years old. We present five independent kinds of evidence that strongly support our invasion hypothesis: 1) a genome-wide lack of genetic variability in X. fastidiosa subsp. fastidiosa found in the US, consistent with a recent common ancestor; 2) evidence for historical allopatry of the North American subspecies X. fastidiosa subsp. multiplex and X. fastidiosa subsp. fastidiosa; 3) evidence that X. fastidiosa subsp. fastidiosa evolved in a more tropical climate than X. fastidiosa subsp. multiplex; 4) much greater genetic variability in the proposed source population in Central America, variation within which the US genotypes are phylogenetically nested; and 5) the circumstantial evidence of importation of known hosts (coffee plants) from Central America directly into southern California just prior to the first known outbreak of the disease. The lack of genetic variation in X. fastidiosa subsp. fastidiosa in the US suggests that preventing additional introductions is important since new genetic variation may undermine PD control measures, or may lead to infection of other crop plants through the creation of novel genotypes via inter-subspecific recombination. In general, geographically mixing of previously isolated subspecies

  14. A bacterial toxin and a non-enveloped virus hijack ER-to-cytosol membrane translocation pathways to cause disease

    PubMed Central

    He, Kaiyu; Ravindran, Madhu Sudhan; Tsai, Billy

    2016-01-01

    A dedicated network of cellular factors ensures that proteins translocated into the endoplasmic reticulum (ER) are folded correctly before they exit this compartment en route to other cellular destinations or for secretion. When proteins misfold, selective ER-resident enzymes and chaperones are recruited to rectify the protein-misfolding problem in order to maintain cellular proteostasis. However, when a protein becomes terminally misfolded, it is ejected into the cytosol and degraded by the proteasome via a pathway called ER-associated degradation (ERAD). Strikingly, toxins and viruses can hijack elements of the ERAD pathway to access the host cytosol and cause infection. This review focuses on emerging data illuminating the molecular mechanisms by which these toxic agents co-opt the ER-to-cytosol translocation process to cause disease. PMID:26362261

  15. 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

  16. Bacterial rheotaxis.

    PubMed

    Marcos; Fu, Henry C; Powers, Thomas R; Stocker, Roman

    2012-03-27

    The motility of organisms is often directed in response to environmental stimuli. Rheotaxis is the directed movement resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates, and spermatozoa. Using carefully controlled microfluidic flows, we show that rheotaxis also occurs in bacteria. Excellent quantitative agreement between experiments with Bacillus subtilis and a mathematical model reveals that bacterial rheotaxis is a purely physical phenomenon, in contrast to fish rheotaxis but in the same way as sperm rheotaxis. This previously unrecognized bacterial taxis results from a subtle interplay between velocity gradients and the helical shape of flagella, which together generate a torque that alters a bacterium's swimming direction. Because this torque is independent of the presence of a nearby surface, bacterial rheotaxis is not limited to the immediate neighborhood of liquid-solid interfaces, but also takes place in the bulk fluid. We predict that rheotaxis occurs in a wide range of bacterial habitats, from the natural environment to the human body, and can interfere with chemotaxis, suggesting that the fitness benefit conferred by bacterial motility may be sharply reduced in some hydrodynamic conditions.

  17. A pitfall in diagnosis of human prion diseases using detection of protease-resistant prion protein in urine. Contamination with bacterial outer membrane proteins.

    PubMed

    Furukawa, Hisako; Doh-ura, Katsumi; Okuwaki, Ryo; Shirabe, Susumu; Yamamoto, Kazuo; Udono, Heiichiro; Ito, Takashi; Katamine, Shigeru; Niwa, Masami

    2004-05-28

    Because a definite diagnosis of prion diseases relies on the detection of the abnormal isoform of prion protein (PrPSc), it has been urgently necessary to establish a non-invasive diagnostic test to detect PrPSc in human prion diseases. To evaluate diagnostic usefulness and reliability of the detection of protease-resistant prion protein in urine, we extensively analyzed proteinase K (PK)-resistant proteins in patients affected with prion diseases and control subjects by Western blot, a coupled liquid chromatography and mass spectrometry analysis, and N-terminal sequence analysis. The PK-resistant signal migrating around 32 kDa previously reported by Shaked et al. (Shaked, G. M., Shaked, Y., Kariv-Inbal, Z., Halimi, M., Avraham, I., and Gabizon, R. (2001) J. Biol. Chem. 276, 31479-31482) was not observed in this study. Instead, discrete protein bands with an apparent molecular mass of approximately 37 kDa were detected in the urine of many patients affected with prion diseases and two diseased controls. Although these proteins also gave strong signals in the Western blot using a variety of anti-PrP antibodies as a primary antibody, we found that the signals were still detectable by incubation of secondary antibodies alone, i.e. in the absence of the primary anti-PrP antibodies. Mass spectrometry and N-terminal protein sequencing analysis revealed that the majority of the PK-resistant 37-kDa proteins in the urine of patients were outer membrane proteins (OMPs) of the Enterobacterial species. OMPs isolated from these bacteria were resistant to PK and the PK-resistant OMPs from the Enterobacterial species migrated around 37 kDa on SDS-PAGE. Furthermore, nonspecific binding of OMPs to antibodies could be mistaken for PrPSc. These findings caution that bacterial contamination can affect the immunological detection of prion protein. Therefore, the presence of Enterobacterial species should be excluded in the immunological tests for PrPSc in clinical samples, in

  18. Foliar Treatments of 2,4-Dichlorophenoxyacetic Acid for Control of Common Scab in Potato Have Beneficial Effects on Powdery Scab Control

    PubMed Central

    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

  19. Bacterial proteases: targets for diagnostics and therapy.

    PubMed

    Kaman, W E; Hays, J P; Endtz, H P; Bikker, F J

    2014-07-01

    Proteases are essential for the proliferation and growth of bacteria, and are also known to contribute to bacterial virulence. This makes them interesting candidates as diagnostic and therapeutic targets for infectious diseases. In this review, the authors discuss the most recent developments and potential applications for bacterial proteases in the diagnosis and treatment of bacterial infections. Current and future bacterial protease targets are described and their limitations outlined.

  20. Neglected bacterial zoonoses.

    PubMed

    Chikeka, I; Dumler, J S

    2015-05-01

    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. Although 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 broad-spectrum diagnoses are actively sought. 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.

  1. 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

  2. The Gut-Brain Axis, Including the Microbiome, Leaky Gut and Bacterial Translocation: Mechanisms and Pathophysiological Role in Alzheimer's Disease.

    PubMed

    Köhler, Cristiano A; Maes, Michael; Slyepchenko, Anastasiya; Berk, Michael; Solmi, Marco; Lanctôt, Krista L; Carvalho, André F

    2016-01-01

    Alzheimer's disease (AD), the most common form of dementia, is a progressive disorder manifested by gradual memory loss and subsequent impairment in mental and behavioral functions. Though the primary risk factor for AD is advancing age, other factors such as diabetes mellitus, hyperlipidemia, obesity, vascular factors and depression play a role in its pathogenesis. The human gastrointestinal tract has a diverse commensal microbial population, which has bidirectional interactions with the human host that are symbiotic in health, and in addition to nutrition, digestion, plays major roles in inflammation and immunity. The most prevalent hypothesis for AD is the amyloid hypothesis, which states that changes in the proteolytic processing of the amyloid precursor protein leads to the accumulation of the amyloid beta (Aβ) peptide. Aβ then triggers an immune response that drives neuroinflammation and neurodegeneration in AD. The specific role of gut microbiota in modulating neuro-immune functions well beyond the gastrointestinal tract may constitute an important influence on the process of neurodegeneration. We first review the main mechanisms involved in AD physiopathology. Then, we review the alterations in gut microbiota and gut-brain axis that might be relevant to mediate or otherwise affect AD pathogenesis, especially those associated with aging. We finally summarize possible mechanisms that could mediate the involvement of gut-brain axis in AD physiopathology, and propose an integrative model.

  3. Phenylalanine and urea foliar application: Effect on grape and must microbiota.

    PubMed

    González-Arenzana, Lucía; Portu, Javier; López, Rosa; Garijo, Patrocinio; Garde-Cerdán, Teresa; López-Alfaro, Isabel

    2017-03-20

    The main aim of this study was to describe the impact of foliar phenylalanine and urea application on grape and must microbial populations. The tool used to perform the ecological study was DGGE conducted with several infusions in non-enriched and enriched liquid media, as well as direct DNA extractions of grapes and musts. A total of 75 microbial species were found in the study. The alpha diversity indices of grape after both foliar nitrogen treatments did not show significant changes in comparison to the control samples, but were modified in some indices in must samples. The phenylalanine must sample was similar to the control, while foliar urea application caused significant changes in microbial diversity and population structure in comparison to the control must. Further research would be necessary to properly predict the impact on winemaking of the effects observed in this study for grape and must microbiota, especially regarding the foliar application of urea.

  4. Foliar application of two silica sols reduced cadmium accumulation in rice grains.

    PubMed

    Liu, Chuanping; Li, Fangbai; Luo, Chunling; Liu, Xinming; Wang, Shihua; Liu, Tongxu; Li, Xiangdong

    2009-01-30

    In the present study, pot experiments were conducted to investigate the effects of foliar application of two silica (Si) sols on the alleviation of cadmium (Cd) toxicity in contaminated soil to rice. Results showed that the foliar application of Si sols significantly increased the dry weight of grains (without husk) and shoots in rice grown in Cd contaminated soil, whereas the Cd concentration in the grains and shoots decreased obviously. The total accumulation of Cd in rice grains also decreased with the application of both of the Si sols, but no significant effect was found on the Cd accumulation in the shoots. For the optimal effect, Si-sol-B should be foliar applied at the tillering-stage during rice growth. The mechanism of Si foliar application to alleviate the toxicity and accumulation of Cd in grains of rice may be related to the probable Cd sequestration in the shoot cell walls.

  5. Evidence for foliar endophytic nitrogen fixation in a widely distributed subalpine conifer

    DOE PAGES

    Moyes, Andrew B.; Kueppers, Lara M.; Pett-Ridge, Jennifer; ...

    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.

  6. 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.

  7. Foliar nickel application alleviates detrimental effects of glyphosate drift on yield and seed quality of wheat.

    PubMed

    Kutman, Bahar Yildiz; Kutman, Umit Baris; Cakmak, Ismail

    2013-09-04

    Glyphosate drift to nontarget crops causes growth aberrations and yield losses. This herbicide can also interact with divalent nutrients and form poorly soluble complexes. The possibility of using nickel (Ni), an essential divalent metal, for alleviating glyphosate drift damage to wheat was investigated in this study. Effects of Ni applications on various growth parameters, seed yield, and quality of durum wheat ( Triticum durum ) treated with sublethal glyphosate at different developmental stages were investigated in greenhouse experiments. Nickel concentrations of various plant parts and glyphosate-induced shikimate accumulation were measured. Foliar but not soil Ni applications significantly reduced glyphosate injuries including yield losses, stunting, and excessive tillering. Both shoot and grain Ni concentrations were enhanced by foliar Ni treatment. Seed germination and seedling vigor were impaired by glyphosate and improved by foliar Ni application to parental plants. Foliar Ni application appears to have a great potential to ameliorate glyphosate drift injury to wheat.

  8. 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

  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. Microencapsulation of a putative probiotic Enterobacter species, C6-6, to protect rainbow trout, Oncorhynchus mykiss (Walbaum), against bacterial coldwater disease.

    PubMed

    Ghosh, B; Cain, K D; Nowak, B F; Bridle, A R

    2016-01-01

    Flavobacterium psychrophilum is the causative agent of bacterial coldwater disease (BCWD), which has a major impact on salmonid aquaculture globally. An Enterobacter species, C6-6, isolated from the gut of rainbow trout, Oncorhynchus mykiss (Walbaum), has been identified as a potential probiotic species providing protection against BCWD. This study examined the effects of alginate microencapsulation on the protective efficacy of C6-6 against BCWD in vivo when administered to rainbow trout fry orally or by intraperitoneal (IP) injection. Viable C6-6 bacteria were microencapsulated successfully, and this process (microencapsulation) did not significantly deteriorate its protective properties as compared to the administration of non-microencapsulated C6-6 bacteria. Both oral and IP delivery of C6-6 achieved significantly better protection than control treatments that did not contain C6-6 bacteria. The highest relative percent survival (RPS) resulted from IP delivery (71.4%) and was significantly greater than the highest oral RPS (38.6%). Successful intestinal colonization was not critical to protective effects of C6-6. The study showed that C6-6 administration, with or without encapsulation, was a viable choice for protecting fry from BCWD especially when administered intraperitoneally.

  11. A Bacterial Component to Alzheimer’s-Type Dementia Seen via a Systems Biology Approach that Links Iron Dysregulation and Inflammagen Shedding to Disease

    PubMed Central

    Pretorius, Etheresia; Bester, Janette; Kell, Douglas B.

    2016-01-01

    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

  12. Breaking the DNA-binding code of Ralstonia solanacearum TAL effectors provides new possibilities to generate plant resistance genes against bacterial wilt disease.

    PubMed

    de Lange, Orlando; Schreiber, Tom; Schandry, Niklas; Radeck, Jara; Braun, Karl Heinz; Koszinowski, Julia; Heuer, Holger; Strauß, Annett; Lahaye, Thomas

    2013-08-01

    Ralstonia solanacearum is a devastating bacterial phytopathogen with a broad host range. Ralstonia solanacearum injected effector proteins (Rips) are key to the successful invasion of host plants. We have characterized Brg11(hrpB-regulated 11), the first identified member of a class of Rips with high sequence similarity to the transcription activator-like (TAL) effectors of Xanthomonas spp., collectively termed RipTALs. Fluorescence microscopy of in planta expressed RipTALs showed nuclear localization. Domain swaps between Brg11 and Xanthomonas TAL effector (TALE) AvrBs3 (avirulence protein triggering Bs3 resistance) showed the functional interchangeability of DNA-binding and transcriptional activation domains. PCR was used to determine the sequence of brg11 homologs from strains infecting phylogenetically diverse host plants. Brg11 localizes to the nucleus and activates promoters containing a matching effector-binding element (EBE). Brg11 and homologs preferentially activate promoters containing EBEs with a 5' terminal guanine, contrasting with the TALE preference for a 5' thymine. Brg11 and other RipTALs probably promote disease through the transcriptional activation of host genes. Brg11 and the majority of homologs identified in this study were shown to activate similar or identical target sequences, in contrast to TALEs, which generally show highly diverse target preferences. This information provides new options for the engineering of plants resistant to R. solanacearum.

  13. Quantitative disease resistance to the bacterial pathogen Xanthomonas campestris involves an Arabidopsis immune receptor pair and a gene of unknown function.

    PubMed

    Debieu, Marilyne; Huard-Chauveau, Carine; Genissel, Anne; Roux, Fabrice; Roby, Dominique

    2016-05-01

    Although quantitative disease resistance (QDR) is a durable and broad-spectrum form of resistance in plants, the identification of the genes underlying QDR is still in its infancy. RKS1 (Resistance related KinaSe1) has been reported recently to confer QDR in Arabidopsis thaliana to most but not all races of the bacterial pathogen Xanthomonas campestris pv. campestris (Xcc). We therefore explored the genetic bases of QDR in A. thaliana to diverse races of X. campestris (Xc). A nested genome-wide association mapping approach was used to finely map the genomic regions associated with QDR to Xcc12824 (race 2) and XccCFBP6943 (race 6). To identify the gene(s) implicated in QDR, insertional mutants (T-DNA) were selected for the candidate genes and phenotyped in response to Xc. We identified two major QTLs that confer resistance specifically to Xcc12824 and XccCFBP6943. Although QDR to Xcc12824 is conferred by At5g22540 encoding for a protein of unknown function, QDR to XccCFBP6943 involves the well-known immune receptor pair RRS1/RPS4. In addition to RKS1, this study reveals that three genes are involved in resistance to Xc with strikingly different ranges of specificity, suggesting that QDR to Xc involves a complex network integrating multiple response pathways triggered by distinct pathogen molecular determinants.

  14. Suppression of the Bacterial Spot Pathogen Xanthomonas euvesicatoria on Tomato Leaves by an Attenuated Mutant of Xanthomonas perforans▿

    PubMed Central

    Hert, A. P.; Marutani, M.; Momol, M. T.; Roberts, P. D.; Olson, S. M.; Jones, J. B.

    2009-01-01

    A bacteriocin-producing strain of the bacterial spot of tomato plant pathogen, Xanthomonas perforans, with attenuated pathogenicity was deployed for biocontrol of a bacteriocin-sensitive strain of the genetically closely related bacterial spot of tomato plant pathogen, X. euvesicatoria. The attenuated mutant (91-118ΔopgHΔbcnB) of X. perforans was tested in leaf tissue and shown to significantly inhibit internal populations of the wild-type X. euvesicatoria strain although significantly less than the wild-type 91-118 strain, whereas in a phyllosphere inhibition assay, the mutant strain reduced epiphytic populations comparably to 91-118. Thus, the attenuated mutant limited the sensitive bacterium more efficiently on the leaf surface than inside the leaf. In field experiments, weekly application of 91-118ΔopgHΔbcnB significantly reduced X. euvesicatoria populations compared to the growers’ standard control (copper hydroxide and mancozeb applied weekly and acibenzolar-S-methyl applied every 2 weeks). The biological control agent, 91-118ΔopgHΔbcnB, applied every 2 weeks also significantly reduced X. euvesicatoria populations in one season but was not significantly different from the growers’ standard control. Potentially, attenuated pathogenic strains could be deployed as biological control agents in order to improve disease control of foliar plant pathogens. PMID:19286785

  15. 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

  16. Foliar water uptake of Tamarix ramosissima from an atmosphere of high humidity.

    PubMed

    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.

  17. Foliar absorption of transuranic elements: influence of physiochemical form and environmental factors

    SciTech Connect

    Cataldo, D.A.; Garland, T.R.; Wildung, R.E.; Thomas, J.M.

    1980-07-01

    The accumulation of plutonium (/sup 238/Pu) and americium (/sup 241/Am) in seeds and roots of Phaseolus vulgaris L. was investigated following foliar interception. Under controlled conditions plants were exposed to well-characterized aerosols of fresh and aged Pu-dioxide, fresh Am-oxides, and Pu-nitrate and Pu-citrate complexes to assess the influence of chemical form and long-term weathering on foliar absorption and subsequent translocation to other plant parts. Mean values for Pu and Am accumulated in seeds and roots 28 days after foliar exposure ranged from 9 to 427 x 10/sup -4/% of that deposited on foilage. These results and previous plant uptake studies indicate that the foliar route is potentially of equal importance to the soil-root pathway as a route of transport. The levels of Pu and Am in seeds and roots resulting from foliar absorption and translocation from foilage were significantly affected by simulated rainfall and by the size of particles to which foilage was exposed. The influence of relative humidity and solution aging of oxides was less definitive; however, results suggest that either or both may infuence foliar absorption and subsequent translocation of Pu and Am to seeds and roots.

  18. 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.

  19. 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

  20. 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

  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. Inflammatory Bowel Diseases: When Natural Friends Turn into Enemies—The Importance of CpG Motifs of Bacterial DNA in Intestinal Homeostasis and Chronic Intestinal Inflammation

    PubMed Central

    Obermeier, Florian; Hofmann, Claudia; Falk, Werner

    2010-01-01

    From numerous studies during the last years it became evident that bacteria and bacterial constituents play a decisive role both in the maintenance of intestinal immune homeostasis as well as in the development and perpetuation of chronic intestinal inflammation. In this review we focus on the role of bacterial DNA which is a potent immunomodulatory component of the bacterial flora. Bacterial DNA has been shown to be protective against experimental colitis. In contrast bacterial DNA essentially contributes to the perpetuation of an already established chronic intestinal inflammation in a Toll-like receptor (TLR)9-dependent manner. This dichotomic action may be explained by a different activation status of essential regulators of TLR signaling like Glycogen synthase kinase 3-β (GSK3-β) depending on the pre-activation status of the intestinal immune system. In this review we suggest that regulators of TLR signaling may be interesting therapeutic targets in IBD aiming at the restoration of intestinal immune homeostasis. PMID:21188217

  3. Effect of humic acid-based amendments with foliar application of Zn and Se on Cd accumulation in tobacco.

    PubMed

    Yu, Yao; Wan, Yanan; Wang, Qi; Li, Huafen

    2017-04-01

    The smoke of tobacco is a major source of exposure to Cd in humans and therefore it is urgent to find a way to a method to reduce Cd accumulation in tobacco. A four-month tobacco pot experiment was conducted to investigate the effects of two base treatments (humic acid-based amendments) and two foliar treatments (Zn and Se) on Cd uptake by tobacco. The results showed that Cd in tobacco was mainly transferred into leaves, which could be significantly reduced by both applied amendments. The Cd contents in leaves were reduced by up to 67%. Foliar Zn alone significantly decreased Cd contents in leaves while foliar Se slightly increased them. When base and foliar treatments were combined, base treatments had dominant effects but those of foliar treatments were not distinct. The applied amendments did reduce Cd contents in all the parts of tobacco and the translocation into leaves and they were more effective than foliar Zn and Se.

  4. 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.

  5. 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 ...

  6. 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.

  7. 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.

  8. 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

  9. 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 Central

    Socheat, Doung

    2016-01-01

    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

  10. Rotavirus Surveillance at a WHO-Coordinated Invasive Bacterial Disease Surveillance Site in Bangladesh: A Feasibility Study to Integrate Two Surveillance Systems.

    PubMed

    Tanmoy, Arif Mohammad; Ahmed, Asm Nawshad Uddin; Arumugam, Rajesh; Hossain, Belal; 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.

  11. Insertion of reticuloendotheliosis virus long terminal repeat into a bacterial artificial chromosome clone of a very virulent Marek's disease virus alters its pathogenicity.

    PubMed

    Mays, Jody K; Silva, Robert F; Kim, Taejoong; Fadly, Aly

    2012-01-01

    Co-cultivation of the JM/102W strain of Marek's disease virus (MDV) with reticuloendotheliosis virus (REV) resulted in the generation of a recombinant MDV containing the REV long terminal repeat (LTR) named the RM1 strain of MDV, a strain that was highly attenuated for oncogenicity but induced severe bursal and thymic atrophy. We hypothesize that the phenotypic changes were solely due to the LTR insertion. Furthermore, we hypothesize that insertion of REV LTR into an analogous location in a different MDV would result in a similar phenotypic change. To test these hypotheses, we inserted the REV LTR into a bacterial artificial chromosome (BAC) clone of a very virulent strain of MDV, Md5, and designated the virus rMd5-RM1-LTR. The rMd5-RM1-LTR virus and the rMd5 virus were passaged in duck embryo fibroblast cells for up to 40 passages before pathogenicity studies. Susceptible chickens were inoculated intra-abdominally at hatch with the viruses rMd5-RM1-LTR, rMd5 BAC parental virus, wild-type strain Md5, or strain RM1 of MDV. The rMd5-RM1-LTR virus was attenuated at cell culture passage 40, whereas the rMd5 BAC without RM1 LTR retained its pathogenicity at cell culture passage 40. Using polymerase chain analysis, the RM1 LTR insert was detected in MDV isolated from buffy coat cells collected from chickens inoculated with rMd5-RM1-LTR, but only at 1 week post inoculation. The data suggest that the presence of the RM1 LTR insert within MDV genome for 1 week post inoculation with virus at hatch is sufficient to cause a reduction in pathogenicity of strain Md5 of MDV.

  12. Management of bacterial kidney disease in Chinook Salmon hatcheries based on broodstock testing by enzyme-linked immunosorbent assay: A multiyear study

    USGS Publications Warehouse

    Munson, A. Douglas; Elliott, Diane G.; Johnson, Keith

    2010-01-01

    From the mid-1980s through the early 1990s, outbreaks of bacterial kidney disease (BKD) caused by Renibacterium salmoninarum continued in Chinook salmon Oncorhynchus tshawytscha in Idaho Department of Fish and Game (IDFG) hatcheries despite the use of three control methods: (1) injection of returning adult fish with erythromycin to reduce prespawning BKD mortality and limit vertical transmission of R. salmoninarum, (2) topical disinfection of green eggs with iodophor, and (3) prophylactic treatments of juvenile fish with erythromycin-medicated feed. In addition, programs to manage BKD through measurement of R. salmoninarum antigen levels in kidney tissues from spawning female Chinook salmon by an enzyme-linked immunosorbent assay (ELISA) were tested over 13–15 brood years at three IDFG hatcheries. The ELISA results were used for either (1) segregated rearing of progeny from females with high ELISA optical density (OD) values (usually ≥0.25), which are indicative of high R. salmoninarum antigen levels, or (2) culling of eggs from females with high ELISA OD values. The ELISA-based culling program had the most profound positive effects on the study populations. Mortality of juvenile fish during rearing was significantly lower at each hatchery for brood years derived from culling compared with brood years for which culling was not practiced. The prevalence of R. salmoninarum in juvenile fish, as evidenced by detection of the bacterium in kidney smears by the direct fluorescent antibody test, also decreased significantly at each hatchery. In addition, the proportions of returning adult females with kidney ELISA OD values of 0.25 or more decreased 56–85% for fish reared in brood years during which culling was practiced, whereas the proportions of ELISA-negative adults increased 55–58%. This management strategy may allow IDFG Chinook salmon hatcheries to reduce or eliminate prophylactic erythromycin-medicated feed treatments. We recommend using ELISA

  13. 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...

  14. 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.

  15. Correlates of Bacterial Ulcers and Acute HSV-2 Infection among Men with Genital Ulcer Disease in South Africa: Age, Recent Sexual Behaviors, and HIV

    PubMed Central

    Leichliter, Jami S.; Lewis, David A.; Paz-Bailey, Gabriela

    2017-01-01

    Data from baseline surveys and STI/HIV laboratory tests (n=615 men) were used to examine correlates of bacterial ulcers (Treponema pallidum, Haemophilus ducreyi, or Chlamydia trachomatis L1–L3 detected in ulcer) and acute HSV-2 ulcers (HSV-2 positive ulcer specimen, HSV-2 sero-negative, and negative for bacterial pathogens) vs. recurrent HSV-2 ulcers (sero-positive), separately. Compared to men with recurrent HSV-2 ulcers, men with bacterial ulcers had larger ulcers but were less likely to be HIV-positive whereas men with acute HSV-2 ulcers were younger with fewer partners. Acute HIV was higher among men with bacterial and acute HSV-2 ulcers; the difference was not statistically significant. PMID:28217702

  16. Correlates of Bacterial Ulcers and Acute HSV-2 Infection among Men with Genital Ulcer Disease in South Africa: Age, Recent Sexual Behaviors, and HIV.

    PubMed

    Leichliter, Jami S; Lewis, David A; Paz-Bailey, Gabriela

    2016-01-01

    Data from baseline surveys and STI/HIV laboratory tests (n=615 men) were used to examine correlates of bacterial ulcers (Treponema pallidum, Haemophilus ducreyi, or Chlamydia trachomatis L1-L3 detected in ulcer) and acute HSV-2 ulcers (HSV-2 positive ulcer specimen, HSV-2 sero-negative, and negative for bacterial pathogens) vs. recurrent HSV-2 ulcers (sero-positive), separately. Compared to men with recurrent HSV-2 ulcers, men with bacterial ulcers had larger ulcers but were less likely to be HIV-positive whereas men with acute HSV-2 ulcers were younger with fewer partners. Acute HIV was higher among men with bacterial and acute HSV-2 ulcers; the difference was not statistically significant.

  17. 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.

  18. Physiological mechanisms drive differing foliar calcium content in ferns and angiosperms.

    PubMed

    Funk, Jennifer L; Amatangelo, Kathryn L

    2013-09-01

    Recent evidence points to ferns containing significantly lower contents of foliar calcium and other cations than angiosperms. This is especially true of more ancient 'non-polypod' fern lineages, which predate the diversification of angiosperms. Calcium is an important plant nutrient, the lack of which can potentially slow plant growth and litter decomposition, and alter soil invertebrate communities. The physiological mechanisms limiting foliar calcium (Ca) content in ferns are unknown. While there is a lot we do not know about Ca uptake and transport in plants, three physiological processes are likely to be important. We measured transpiration rate, cation exchange capacity, and leaching loss to determine which process most strongly regulates foliar Ca content in a range of fern and co-occurring understory angiosperm species from a montane Hawaiian rainforest. We found higher instantaneous and lifetime (corrected for leaf lifespan) transpiration rates in angiosperms relative to ferns. Ferns preferentially incorporated Ca into leaves relative to strontium, which suggests that root or stem cation exchange capacity differs between ferns and angiosperms, potentially affecting calcium transport in plants. There were no differences in foliar Ca leaching loss between groups. Among the physiological mechanisms measured, foliar Ca was most strongly correlated with leaf-level transpiration rate and leaf lifespan. This suggests that inter-specific differences in a leaf's lifetime transpiration may play a significant role in determining plant nutrition.

  19. Host genotype shapes the foliar fungal microbiome of balsam poplar (Populus balsamifera).

    PubMed

    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.

  20. 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

  1. 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.

  2. Effects of ozone on the foliar histology of the mastic plant (Pistacia lentiscus L.).

    PubMed

    Reig-Armiñana, J; Calatayud, V; Cerveró, J; García-Breijo, F J; Ibars, A; Sanz, M J

    2004-11-01

    An open-top chamber study was conducted to investigate the tissue and cellular-level foliar effects of ozone (O3) on a Mediterranean evergreen species, the mastic plant (Pistacia lentiscus L.). Plants were exposed at three different O3 levels, and leaf samples were collected periodically from the beginning of the exposure. Although no visible foliar injury was evident, alterations of the plastids and vacuoles in the mesophyll were observed. Senescence processes were accelerated with an anomalous stacking of tannin vacuoles, and a reduction in the size and number of the chloroplasts. Overall, most of the modifications induced by O3 were consistent with previously reported observations on deciduous broadleaf species, with the exception of alterations in the cells covering the secretory channels, reported here as a new finding. Comments on the feasibility of using microscopy to validate O3 related field observations and subtle foliar injury are also given.

  3. Nutrient leaching from conifer needles in relation to foliar apoplast cation-exchange capacity

    SciTech Connect

    Turner, D.P.; van Broekhuizen, H.J.

    1992-01-01

    Limited evidence to date suggests that acidic precipitation promotes leaching of nutrient cations from conifer foliage. In order to evaluate the relative contribution of the apoplast cation exchange complex and symplast nutrient pools to the leached ions, the magnitude of potential foliar leaching in response to acidic precipitation was compared to foliar apoplast cation exchange capacity (CEC) for two conifer tree species (Pseudotsuga menziesii and Picea engelmanii). Leaching increased with decreasing pH and increasing time of immersion. At pH 2.1 and 3.1, equivalents of H+ depleted from the acidic solutions approximated equivalent of cations gained by the solutions. Maximum amounts leached were less than 40 micro equiv/g dry weight of needles for all ions combined. Measured foliar apoplast CEC for these species was approximately 120 micro equiv/g dry weight of needles. These relative magnitudes indicated that the apoplast provided the leached ions.

  4. 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

  5. Purple Phototrophic Bacterium Enhances Stevioside Yield by Stevia rebaudiana Bertoni via Foliar Spray and Rhizosphere Irrigation

    PubMed Central

    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

  6. 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.

  7. 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.

  8. Magnetic resonance imaging of sugar beet taproots in soil reveals growth reduction and morphological changes during foliar Cercospora beticola infestation

    PubMed Central

    Schmittgen, Simone; Metzner, Ralf; Van Dusschoten, Dagmar; Jansen, Marcus; Fiorani, Fabio; Jahnke, Siegfried; Rascher, Uwe; Schurr, Ulrich

    2015-01-01

    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. 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.

  10. 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...

  11. 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

    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

  12. 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

  13. Brood stock segregation for the control of bacterial kidney disease can affect mortality of progeny chinook salmon (Oncorhynchus tshawytscha) in seawater

    USGS Publications Warehouse

    Elliott, Diane G.; Pascho, Ronald J.; Palmisano, Aldo N.

    1995-01-01

    Segregation of spring chinook salmon (Oncorhynchus tshawytscha) brood stock based on the measurement of maternal Renibacterium salmoninarum infection levels by the enzyme-linked immunosorbent assay (ELISA) and the fluorescent antibody technique (FAT) was previously shown to affect the prevalence and levels of bacterial kidney disease (BKD) in progeny fish during hatchery rearing. Smolts from that study were subjected to standardized fish health and condition evaluation procedures 2 weeks before the conclusion of hatchery rearing and release of the fish for migration to the Pacific Ocean. The results suggested that the general health of the smolts in the progeny group from parents that had low R. salmoninarum infection levels or tested negative for R. salmoninarum (low-BKD group) was better than that of the smolts in the progeny group from female parents with high R. salmoninarum infection levels (high-BKD group). Testing by the ELISA showed that the overall severity of R. salmoninarum infection also was lower in the smolts from the low-BKD group. Subgroups of smolts from the study were acclimated to tanks of seawater for extended holding. After a 22-day acclimation period and 98 days in full-strength (29 ppt salinity) seawater, total mortality was 12% in the low-BKD group and 44% in the high-BKD group. All of the mortality in the low-BKD group and 85% of the mortality in the high-BKD group occurred after the fish were transferred to full-strength seawater. Testing of kidney tissues from all dead fish by the FAT revealed that 85% of the fish that died in the high-BKD group had high R. salmoninarum numbers, indicating that BKD was the cause of death. In contrast, none of the fish that died in the low-BKD group had detectable numbers of R. salmoninarum. We concluded that brood stock segregation by use of the ELISA and the FAT can affect mortality and the R. salmoninarum status of progeny chinook salmon for as long as 21 months after hatching, even after the fish have

  14. Profiling the culprit in Alzheimer's disease (AD): bacterial toxic proteins - Will they be significant for the aetio-pathogenesis of AD and the transmissible spongiform encephalopathies?

    PubMed

    Schmitt, H Peter

    2007-01-01

    The aetiology of Alzheimer's disease (AD) and the transmissible spongiform encephalopathies (tSEs) is still elusive. The concept that prion protein (PrP(Sc)) is the aetiological agent (infectious protein) in the tSEs has recently been questioned. In AD, the cause of the aberrant cleavage of the beta-amyloid precursor protein (APP), resulting in the production of amyloidogenic Abeta fragments, has yet remained obscure. Moreover, the amyloid hypothesis of AD has been seriously challenged. In both AD and the tSEs, pathogens of various nature, including bacteria, have been discussed as possible causal factors. However, aetiological considerations have completely neglected microbial products such as the bacterial toxic proteins (BTPs). The present paper is aimed at drawing a "culprit profile" of these toxic molecules that can exert, at low-dosage, neuro-degeneration through various effects. Clearly, BTPs may affect cell-surface receptors including modulatory amine transmitter receptor expression, block neuro-transmitter release, increase intra-cellular Ca(2+) levels, affect intra-cellular signal transduction, change cyto-skeletal processing, alter synaptic transmission, influence APP proteolysis, interact with cell surface proteins like PrP(C) or their GPI anchors, act as chaperones inducing conformational change in proteins (e.g., PrP(C) to PrP(Sc)), alter lipid membrane integrity by affecting phospholipases or forming pores and channels, induce vacuolar (spongiform) change and elicit inflammatory reactions with cytokine production including cytokines that were demonstrated in the AD brain. Like PrP(Sc), BTPs can be heat-stable and acid-resistant. BTPs can meet the key-proteins of AD and tSEs in the lipid-rich domains of the plasma membrane called rafts. Basically, this might enable them to initiate a large variety of unfavourable molecular events, eventually resulting in pathogenetic cascades as in AD and the tSEs. All in all, their profile lends support to the

  15. 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

  16. 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

  17. 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,…

  18. Foliar and Seed Application of Amino Acids Affects the Antioxidant Metabolism of the Soybean Crop

    PubMed Central

    Teixeira, Walquíria F.; Fagan, Evandro B.; Soares, Luís H.; Umburanas, Renan C.; Reichardt, Klaus; Neto, Durval D.

    2017-01-01

    In recent years, the application of natural substances on crops has been intensified in order to increase the resistance and yield of the soybean crop. Among these products are included plant biostimulants that may contain algae extracts, amino acids, and plant regulators in their composition. However, there is little information on the isolated effect of each of these constituents. The objective of this research was to evaluate the effect of the application of isolated amino acids on the antioxidant metabolism of the soybean crop. Experiments were carried out in a greenhouse and in the field with the application of the amino acids glutamate, phenylalanine, cysteine, glycine in seed treatment, and foliar application at V4 growth stage. Antioxidant metabolism constituents evaluated were superoxide dismutase, catalase, peroxidase, hydrogen peroxide content, proline, and lipid peroxidation. In addition, resistance enzymes as polyphenol oxidase and phenylalanine ammonia-lyase (PAL) were evaluated. In both experiments, the use of cysteine, only in seed treatment and in both seed treatment and foliar application increased the activity of the enzyme PAL and catalase. Also in both experiments, the use of phenylalanine increased the activity of the enzyme PAL when the application was carried out as foliar application or both in seed treatment and foliar application. In the field experiment, the application of glutamate led to an increase in the activity of the catalase and PAL enzymes for seed treatment and foliar application. The use of the set of amino acids was only efficient in foliar application, which led to a greater activity of the enzymes peroxidase, PAL, and polyphenol oxidase. The other enzymes as well as lipid peroxidation and hydrogen peroxide presented different results according to the experiment. Therefore, glutamate, cysteine, phenylalanine, and glycine can act as signaling amino acids in soybean plants, since small doses are enough to increase the activity

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Bacterial endophyte communities in the foliage of coast redwood and giant sequoia

    SciTech Connect

    Carrell, Alyssa A.; Frank, Anna C.

    2015-09-22

    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. Lastly, 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

  4. Bacterial endophyte communities in the foliage of coast redwood and giant sequoia

    DOE PAGES

    Carrell, Alyssa A.; Frank, Anna C.

    2015-09-22

    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 inmore » 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. Lastly, 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

  5. 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.

  6. Iron concentration, bioavailability, and nutritional quality of polished rice affected by different forms of foliar iron fertilizer.

    PubMed

    He, Wanling; Shohag, M J I; Wei, Yanyan; Feng, Ying; Yang, Xiaoe

    2013-12-15

    The present study compared the effects of four different forms of foliar iron (Fe) fertilizers on Fe concentration, bioavailability and nutritional quality of polished rice. The results showed that foliar fertilisation at the anthesis stage was an effective way to promote Fe concentration and bioavailability of polished rice, especially in case of DTPA-Fe. Compared to the control, foliar application of DTPA-Fe increased sulphur concentration and the nutrition promoter cysteine content, whereas decreased phosphorus concentration and the antinutrient phytic acid content of polished rice, as a result increased 67.2% ferrtin formation in Caco-2 cell. Moreover, foliar DTPA-Fe application could maintain amylase, protein and minerals quality of polished rice. According to the current study, DTPA-Fe is recommended as an excellent foliar Fe form for Fe biofortification program.

  7. 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

  8. Bacterial Vaginosis

    MedlinePlus

    ... Pediatrician Health Issues Conditions Abdominal ADHD Allergies & Asthma Autism Cancer Chest & Lungs Chronic Conditions Cleft & Craniofacial Developmental ... Last Updated 3/9/2016 Source Adapted from Immunizations and Infectious Diseases: An Informed Parent's Guide (Copyright © ...

  9. Biochar Amendment Modifies Expression of Soybean and Rhizoctonia solani Genes Leading to Increased Severity of Rhizoctonia Foliar Blight.

    PubMed

    Copley, Tanya; Bayen, Stéphane; Jabaji, Suha

    2017-01-01

    Application of biochar, a pyrolyzed biomass from organic sources, to agricultural soils is considered a promising strategy to sustain soil fertility leading to increased plant productivity. It is also known that applications of biochar to soilless potting substrates and to soil increases resistance of plants against diseases, but also bear the potential to have inconsistent and contradictory results depending on the type of biochar feedstock and application rate. The following study examined the effect of biochar produced from maple bark on soybean resistance against Rhizoctonia foliar blight (RFB) disease caused by Rhizoctonia solani, and examined the underlying molecular responses of both soybean and R. solani during interaction with biochar application. Soybean plants were grown in the presence of 1, 3, or 5% (w/w) or absence of maple bark biochar for 2 weeks, and leaves were infected with R. solani AG1-IA. At lower concentrations (1 and 3%), biochar was ineffective against RFB, however at the 5% amendment rate, biochar was conducive to RFB with a significant increase in disease severity. For the first time, soybean and R. solani responsive genes were monitored during the development of RFB on detached leaves of plants grown in the absence and presence of 5% biochar at 0, 6, 12, and 24 h post-inoculation (h.p.i.). Generally, large decreases in soybean transcript abundances of genes associated with primary metabolism such as glycolysis, tricarboxylic acid (TCA) cycle, starch, amino acid and glutathione metabolism together with genes associated with plant defense and immunity such as salicylic acid (SA) and jasmonic acid pathways were observed after exposure of soybean to high concentration of biochar. Such genes are critical for plant protection against biotic and abiotic stresses. The general down-regulation of soybean genes and changes in SA hormonal balance were tightly linked with an increased susceptibility to RFB. In conjunction, R. solani genes associated

  10. Biochar Amendment Modifies Expression of Soybean and Rhizoctonia solani Genes Leading to Increased Severity of Rhizoctonia Foliar Blight

    PubMed Central

    Copley, Tanya; Bayen, Stéphane; Jabaji, Suha

    2017-01-01

    Application of biochar, a pyrolyzed biomass from organic sources, to agricultural soils is considered a promising strategy to sustain soil fertility leading to increased plant productivity. It is also known that applications of biochar to soilless potting substrates and to soil increases resistance of plants against diseases, but also bear the potential to have inconsistent and contradictory results depending on the type of biochar feedstock and application rate. The following study examined the effect of biochar produced from maple bark on soybean resistance against Rhizoctonia foliar blight (RFB) disease caused by Rhizoctonia solani, and examined the underlying molecular responses of both soybean and R. solani during interaction with biochar application. Soybean plants were grown in the presence of 1, 3, or 5% (w/w) or absence of maple bark biochar for 2 weeks, and leaves were infected with R. solani AG1-IA. At lower concentrations (1 and 3%), biochar was ineffective against RFB, however at the 5% amendment rate, biochar was conducive to RFB with a significant increase in disease severity. For the first time, soybean and R. solani responsive genes were monitored during the development of RFB on detached leaves of plants grown in the absence and presence of 5% biochar at 0, 6, 12, and 24 h post-inoculation (h.p.i.). Generally, large decreases in soybean transcript abundances of genes associated with primary metabolism such as glycolysis, tricarboxylic acid (TCA) cycle, starch, amino acid and glutathione metabolism together with genes associated with plant defense and immunity such as salicylic acid (SA) and jasmonic acid pathways were observed after exposure of soybean to high concentration of biochar. Such genes are critical for plant protection against biotic and abiotic stresses. The general down-regulation of soybean genes and changes in SA hormonal balance were tightly linked with an increased susceptibility to RFB. In conjunction, R. solani genes associated