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Sample records for potential biocontrol agents

  1. Potential biocontrol agents for biofouling on artificial structures.

    PubMed

    Atalah, Javier; Newcombe, Emma M; Hopkins, Grant A; Forrest, Barrie M

    2014-09-01

    The accumulation of biofouling on coastal structures can lead to operational impacts and may harbour problematic organisms, including non-indigenous species. Benthic predators and grazers that can supress biofouling, and which are able to be artificially enhanced, have potential value as augmentative biocontrol agents. The ability of New Zealand native invertebrates to control biofouling on marina pontoons and wharf piles was tested. Caging experiments evaluated the ability of biocontrol to mitigate established biofouling, and to prevent fouling accumulation on defouled surfaces. On pontoons, the gastropods Haliotis iris and Cookia sulcata reduced established biofouling cover by >55% and largely prevented the accumulation of new biofouling over three months. On wharf piles C. sulcata removed 65% of biofouling biomass and reduced its cover by 73%. C. sulcata also had better retention and survival rates than other agents. Augmentative biocontrol has the potential to be an effective method to mitigate biofouling on marine structures.

  2. Potential of Pseudomonas chlororaphis subsp. aurantiaca Strain Pcho10 as a Biocontrol Agent Against Fusarium graminearum.

    PubMed

    Hu, Weiqun; Gao, Qixun; Hamada, Mohamed Sobhy; Dawood, Dawood Hosni; Zheng, Jingwu; Chen, Yun; Ma, Zhonghua

    2014-12-01

    To develop an effective biocontrol strategy for management of Fusarium head blight on wheat caused by Fusarium graminearum, the bacterial biocontrol agent Pcho10 was selected from more than 1,476 wheat-head-associated bacterial strains according to its antagonistic activity in vitro. This strain was subsequently characterized as Pseudomonas chlororaphis subsp. aurantiaca based on 16S ribosomal DNA sequence analysis, assays of the BIOLOG microbial identification system, and unique pigment production. The major antifungal metabolite produced by Pcho10 was further identified as phenazine-1-carboxamide (PCN) on the basis of nuclear magnetic resonance data. The core PCN biosynthesis gene cluster in Pcho10 was cloned and sequenced. PCN showed strong inhibitory activity against F. graminearum conidial germination, mycelial growth, and deoxynivalenol production. Tests both under growth chamber conditions and in field trials showed that Pcho10 well colonized on the wheat head and effectively controlled the disease caused by F. graminearum. Results of this study indicate that P. chlororaphis subsp. aurantiaca Pcho10 has high potential to be developed as a biocontrol agent against F. graminearum. To our knowledge, this is the first report of the use of P. chlororaphis for the management of Fusarium head blight.

  3. Potential of Pseudomonas chlororaphis subsp. aurantiaca Strain Pcho10 as a Biocontrol Agent Against Fusarium graminearum.

    PubMed

    Hu, Weiqun; Gao, Qixun; Hamada, Mohamed Sobhy; Dawood, Dawood Hosni; Zheng, Jingwu; Chen, Yun; Ma, Zhonghua

    2014-12-01

    To develop an effective biocontrol strategy for management of Fusarium head blight on wheat caused by Fusarium graminearum, the bacterial biocontrol agent Pcho10 was selected from more than 1,476 wheat-head-associated bacterial strains according to its antagonistic activity in vitro. This strain was subsequently characterized as Pseudomonas chlororaphis subsp. aurantiaca based on 16S ribosomal DNA sequence analysis, assays of the BIOLOG microbial identification system, and unique pigment production. The major antifungal metabolite produced by Pcho10 was further identified as phenazine-1-carboxamide (PCN) on the basis of nuclear magnetic resonance data. The core PCN biosynthesis gene cluster in Pcho10 was cloned and sequenced. PCN showed strong inhibitory activity against F. graminearum conidial germination, mycelial growth, and deoxynivalenol production. Tests both under growth chamber conditions and in field trials showed that Pcho10 well colonized on the wheat head and effectively controlled the disease caused by F. graminearum. Results of this study indicate that P. chlororaphis subsp. aurantiaca Pcho10 has high potential to be developed as a biocontrol agent against F. graminearum. To our knowledge, this is the first report of the use of P. chlororaphis for the management of Fusarium head blight. PMID:24941327

  4. Potential Bio-Control Agent from Rhodomyrtus tomentosa against Listeria monocytogenes

    PubMed Central

    Odedina, Grace Fiyinfoluwa; Vongkamjan, Kitiya; Voravuthikunchai, Supayang Piyawan

    2015-01-01

    Listeria monocytogenes is an important foodborne pathogen implicated in many outbreaks of listeriosis. This study aimed at screening for the potential use of Rhodomyrtus tomentosa ethanolic leaf extract as a bio-control agent against L. monocytogenes. Twenty-two L. monocytogenes isolates were checked with 16 commercial antibiotics and isolates displayed resistance to 10 antibiotics. All the tested isolates were sensitive to the extract with inhibition zones ranging from 14 to 16 mm. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged from 16 to 32 µg/mL and 128 to 512 µg/mL, respectively. Time-kill assay showed that the extract had remarkable bactericidal effects on L. monocytogenes. The extract at a concentration of 16 µg/mL reduced tolerance to 10% NaCl in L. monocytogenes in 4 h. Stationary phase L. monocytogenes cells were rapidly inactivated by greater than 3-log units within 30 min of contact time with R. tomentosa extract at 128 µg/mL. Electron microscopy revealed fragmentary bacteria with changes in the physical and morphological properties. Our study demonstrates the potential of the extract for further development into a bio-control agent in food to prevent the incidence of L. monocytogenes contamination. PMID:26371033

  5. Potential Bio-Control Agent from Rhodomyrtus tomentosa against Listeria monocytogenes.

    PubMed

    Odedina, Grace Fiyinfoluwa; Vongkamjan, Kitiya; Voravuthikunchai, Supayang Piyawan

    2015-09-07

    Listeria monocytogenes is an important foodborne pathogen implicated in many outbreaks of listeriosis. This study aimed at screening for the potential use of Rhodomyrtus tomentosa ethanolic leaf extract as a bio-control agent against L. monocytogenes. Twenty-two L. monocytogenes isolates were checked with 16 commercial antibiotics and isolates displayed resistance to 10 antibiotics. All the tested isolates were sensitive to the extract with inhibition zones ranging from 14 to 16 mm. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged from 16 to 32 µg/mL and 128 to 512 µg/mL, respectively. Time-kill assay showed that the extract had remarkable bactericidal effects on L. monocytogenes. The extract at a concentration of 16 µg/mL reduced tolerance to 10% NaCl in L. monocytogenes in 4 h. Stationary phase L. monocytogenes cells were rapidly inactivated by greater than 3-log units within 30 min of contact time with R. tomentosa extract at 128 µg/mL. Electron microscopy revealed fragmentary bacteria with changes in the physical and morphological properties. Our study demonstrates the potential of the extract for further development into a bio-control agent in food to prevent the incidence of L. monocytogenes contamination.

  6. Arbuscular mycorrhizal fungi: potential biocontrol agents against the damaging root hemiparasite Pedicularis kansuensis?

    PubMed

    Sui, Xiao-Lin; Li, Ai-Rong; Chen, Yan; Zhuo, Lu; Liu, Yan-Yan

    2014-04-01

    Spatial expansion of root hemiparasitic Pedicularis kansuensis in Bayanbulak Grassland of Xinjiang Uygur Autonomous Region (China) has caused great loss of herbage yield and has threatened the local livestock industry. Current management practices using manual eradication and chemical control have been proved problematic. Arbuscular mycorrhizal (AM) fungi have been suggested to be potential biocontrol agents against a number of plant pests, but experimental evidence is lacking against weedy P. kansuensis. In this study, we tested the hypothesis that inoculation with AM fungi will cause growth depression in P. kansuensis and reduce its damage to host plants. Based on the confirmation of AM status and host community of the hemiparasite in the field, a pot cultivation experiment was conducted to test the influence of an AM fungus (Glomus mosseae) on growth of P. kansuensis and the parasitized host (Elymus nutans). AM colonization was observed in roots of P. kansuensis, but the levels were much lower than those of its adjacent host species. A negative correlation between AM levels and the numbers of haustoria was detected for the field samples of the hemiparasite. Strong suppression of haustorium formation, a significant reduction in plant dry weight (DW), as well as marked reduction in the survival rate of P. kansuensis after inoculation with AM fungi was observed. In contrast, inoculation with G. mosseae increased root DW and whole plant DW of parasitized host plants. Our findings demonstrated significantly repressive effects of AM fungi on growth performance of P. kansuensis with and without the presence of a host. The potential of AM fungi as biocontrol agents against the damaging hemiparasite was confirmed.

  7. A Novel Bacteriophage Targeting Cronobacter sakazakii Is a Potential Biocontrol Agent in Foods

    PubMed Central

    Lee, Ju-Hoon; Bai, Jaewoo; Shin, Hakdong; Kim, Yeran; Park, Bookyung; Heu, Sunggi

    2015-01-01

    Cronobacter sakazakii is an important pathogen that causes high mortality in infants. Due to its occasional antibiotic resistance, a bacteriophage approach might be an alternative effective method for the control of this pathogen. To develop a novel biocontrol agent using bacteriophages, the C. sakazakii-infecting phage CR5 was newly isolated and characterized. Interestingly, this phage exhibited efficient and relatively durable host lysis activity. In addition, a specific gene knockout study and subsequent complementation experiment revealed that this phage infected the host strain using the bacterial flagella. The complete genome sequence analysis of phage CR5 showed that its genome contains 223,989 bp of DNA, including 231 predicted open reading frames (ORFs), and it has a G+C content of 50.06%. The annotated ORFs were classified into six functional groups (structure, packaging, host lysis, DNA manipulation, transcription, and additional functions); no gene was found to be related to virulence or toxin or lysogen formation, but >80% of the predicted ORFs are unknown. In addition, a phage proteomic analysis using SDS-PAGE and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) revealed that seven phage structural proteins are indeed present, supporting the ORF predictions. To verify the potential of this phage as a biocontrol agent against C. sakazakii, it was added to infant formula milk contaminated with a C. sakazakii clinical isolate or food isolate, revealing complete growth inhibition of the isolates by the addition of phage CR5 when the multiplicity of infection (MOI) was 105. PMID:26497465

  8. Plant growth-promoting rhizobacteria (PGPR): Their potential as antagonists and biocontrol agents

    PubMed Central

    Beneduzi, Anelise; Ambrosini, Adriana; Passaglia, Luciane M.P.

    2012-01-01

    Bacteria that colonize plant roots and promote plant growth are referred to as plant growth-promoting rhizobacteria (PGPR). PGPR are highly diverse and in this review we focus on rhizobacteria as biocontrol agents. Their effects can occur via local antagonism to soil-borne pathogens or by induction of systemic resistance against pathogens throughout the entire plant. Several substances produced by antagonistic rhizobacteria have been related to pathogen control and indirect promotion of growth in many plants, such as siderophores and antibiotics. Induced systemic resistance (ISR) in plants resembles pathogen-induced systemic acquired resistance (SAR) under conditions where the inducing bacteria and the challenging pathogen remain spatially separated. Both types of induced resistance render uninfected plant parts more resistant to pathogens in several plant species. Rhizobacteria induce resistance through the salicylic acid-dependent SAR pathway, or require jasmonic acid and ethylene perception from the plant for ISR. Rhizobacteria belonging to the genera Pseudomonas and Bacillus are well known for their antagonistic effects and their ability to trigger ISR. Resistance-inducing and antagonistic rhizobacteria might be useful in formulating new inoculants with combinations of different mechanisms of action, leading to a more efficient use for biocontrol strategies to improve cropping systems. PMID:23411488

  9. Characterization of a new Pseudomonas aeruginosa strain NJ-15 as a potential biocontrol agent.

    PubMed

    Bano, Nazneen; Musarrat, Javed

    2003-05-01

    Phylogenetic characterization of soil isolate NJ-15, based on sequence homology of a partial 746-bp fragment of 16SrDNA amplicon, with the ribosomal database sequences (http://www.msu.edu/RDP/cgis/phylip.cgi), validated the strain as Pseudomonas aeruginosa. The strain NJ-15 produced a substantial amount of indole acetic acid (IAA) in tryptophan-supplemented medium. Besides, the strain also exhibited significant production of both the siderophore and hydrogen cyanide (HCN) on chrome azurol S and King's B media, respectively. The data revealed lower HCN production under iron-limiting conditions vis-à-vis higher HCN release with iron stimulation. Significant growth inhibition of phytopathogenic fungi occurred in the order as Fusarium oxysporum > Trichoderma herizum > Alternaria alternata > Macrophomina phasiolina upon incubation with strain NJ-15 cells. Thus, the secondary metabolites producing new Pseudomonas aeruginosa strain NJ-15 exhibited innate potential of plant growth promotion and biocontrol activities in vitro.

  10. Potential of Microbispora sp. V2 as biocontrol agent against Sclerotium rolfsii, the causative agent of southern blight of Zea mays L (Baby corn)--in vitro studies.

    PubMed

    Patil, N N; Waghmode, M S; Gaikwad, P S; Gajbhiye, M H; Gunjal, A B; Nawani, N N; Kapadnis, B P

    2014-11-01

    The study was undertaken with the aim of exploring novel and beneficial agro activities of rare actinomycetes like Microbispora sp. V2. The antagonistic activity of Microbispora sp. V2 was evaluated as a biocontrol agents against Sclerotium rolfsii, a soil-borne fungal plant pathogen. The methodology performed for evaluation of biocontrol agent was in vitro evaluation assay which comprised of three tests viz., cellophane overlay technique, seed germination test and Thiram (fungicide) tolerance of Microbispora sp. V2. The isolate was found to inhibit the fungal pathogen Sclerotium rolfsii to 91.43% in cellophane assay. In seed germination assay, Microbispora sp. V2 treated seeds resulted in 25.75% increased germination efficiency, as compared to seeds infected by Sclerotium rolfsii. The isolate Microbispora sp. V2 could tolerate 1000 microg mL(-1) of Thiram (fungicide). The in vitro assay studies proved that Microbispora sp. V2 can be used as antifungal antagonist and thus posses' great potential as biocontrol agent against southern blight caused by Sclerotium rolfsii in Zea mays L (Baby corn) which causes large economical losses.

  11. A case of ecological specialization in ladybirds: Iberorhyzobius rondensis (Coleoptera: Coccinellidae), potential biocontrol agent of Matsucoccus feytaudi (Hemiptera: Matsucoccidae).

    PubMed

    Tavares, C; Jactel, H; van Halder, I; Mendel, Z; Branco, M

    2014-06-01

    Specialization is an important attribute of a biological control agent. The maritime pine bast scale, Matsucoccus feytaudi Ducasse (Hemiptera Matsucoccidae), is an invasive species in Southeast France and the North of Italy. Iberorhyzobius rondensis Eizaguirre (Coleoptera: Coccinellidae), is a recently described ladybird species. Both adults and larvae are predaceous, feeding on egg masses of M. feytaudi, and are strongly attracted to M. feytaudi's sex pheromone. To evaluate the potential of I. rondensis as a biocontrol agent of the scale, we studied its niche breadth and prey range with emphasis on pine forests and hemipterans as tested prey. In this study, I. rondensis was found to achieve complete development only when fed on M. feytaudi egg masses (92.9% survival) and an artificial prey: eggs of Ephestia kuehniella Zeller (27.6% survival). From the 2nd instar onwards, complete development could be achieved using other prey species, although larvae had significantly higher mortality and slower development. In choice tests, M. feytaudi was the preferred prey. Surveys of the ladybird populations in the Iberian Peninsula revealed that it was found exclusively on Pinus pinaster Aiton, the sole host of M. feytaudi. The unusual specialization of I. rondensis, among other predaceous ladybirds, makes it an appropriate candidate for classical biological control of M. feytaudi. PMID:24666751

  12. A case of ecological specialization in ladybirds: Iberorhyzobius rondensis (Coleoptera: Coccinellidae), potential biocontrol agent of Matsucoccus feytaudi (Hemiptera: Matsucoccidae).

    PubMed

    Tavares, C; Jactel, H; van Halder, I; Mendel, Z; Branco, M

    2014-06-01

    Specialization is an important attribute of a biological control agent. The maritime pine bast scale, Matsucoccus feytaudi Ducasse (Hemiptera Matsucoccidae), is an invasive species in Southeast France and the North of Italy. Iberorhyzobius rondensis Eizaguirre (Coleoptera: Coccinellidae), is a recently described ladybird species. Both adults and larvae are predaceous, feeding on egg masses of M. feytaudi, and are strongly attracted to M. feytaudi's sex pheromone. To evaluate the potential of I. rondensis as a biocontrol agent of the scale, we studied its niche breadth and prey range with emphasis on pine forests and hemipterans as tested prey. In this study, I. rondensis was found to achieve complete development only when fed on M. feytaudi egg masses (92.9% survival) and an artificial prey: eggs of Ephestia kuehniella Zeller (27.6% survival). From the 2nd instar onwards, complete development could be achieved using other prey species, although larvae had significantly higher mortality and slower development. In choice tests, M. feytaudi was the preferred prey. Surveys of the ladybird populations in the Iberian Peninsula revealed that it was found exclusively on Pinus pinaster Aiton, the sole host of M. feytaudi. The unusual specialization of I. rondensis, among other predaceous ladybirds, makes it an appropriate candidate for classical biological control of M. feytaudi.

  13. Isolation and identification of actinomycetes from a compost-amended soil with potential as biocontrol agents.

    PubMed

    Cuesta, Gonzalo; García-de-la-Fuente, Rosana; Abad, Manuel; Fornes, Fernando

    2012-03-01

    The search for new biocontrol strategies to inhibit the growth of phytopathogenic microorganisms has become widely widespread due to environmental concerns. Among actinomycetes, Streptomyces species have been extensively studied since they have been recognized as important sources of antibiotics. Actinomycete strains were isolated from a calcareous soil, 2 two-phase olive mill waste ('alperujo') composts, and the compost-amended soil by using selective media, and they were then co-cultured with 5 phytopathogenic fungi and 1 bacterium to perform an in vitro antagonism assay. Forty-nine actinomycete strains were isolated, 12 of them showing a great antagonistic activity towards the phytopathogenic microorganisms tested. Isolated strains were identified by 16S rDNA sequence analysis and phenotypic procedures. Eleven isolates concerned the genus Streptomyces and 1 actinomycete with chitinolytic activity belonged to the genus Lechevalieria. PMID:21190787

  14. Methods for the Evaluation of the Bioactivity and Biocontrol Potential of Species of Trichoderma.

    PubMed

    Steyaert, Johanna; Hicks, Emily; Kandula, Janaki; Kandula, Diwakar; Alizadeh, Hossein; Braithwaite, Mark; Yardley, Jessica; Mendoza-Mendoza, Artemio

    2016-01-01

    Members of the genus Trichoderma comprise the majority of commercial fungal biocontrol agents of plant diseases. As such, there is a wealth of information available on the analysis of their biocontrol potential and the mechanisms behind their superior abilities. This chapter aims to summarize the most common methods utilized within a Trichoderma biocontrol program for assessing the biological properties of individual strains. PMID:27565489

  15. Wonder world of phages: potential biocontrol agents safeguarding biosphere and health of animals and humans- current scenario and perspectives.

    PubMed

    Tiwari, Ruchi; Chakraborty, Sandip; Dhama, Kuldeep; Wani, Mohd Yaqoob; Kumar, Amit; Kapoor, Sanjay

    2014-02-01

    Darwin's theory of natural selection and concept of survival of fittest of Wallace is a universal truth which derives the force of life among all live entities on this biosphere. Issues regarding food safety along with increased drug resistance and emerging zoonotic infections have proved that multidisciplinary efforts are in demand for human and animal welfare. This has led to development of various novel therapies the list of which remains incomplete without mentioning about phages. Homologous and non-homologous recombination along with point mutation and addition of new genes play role in their evolution. The rapid emergence of the antibiotic resistant strains of bacteria have created keen interest in finding necessary alternatives to check microbial infections and there comes the importance of phages. Phages kill the bacteria either by lysis or by releasing holins. Bacteriophages; the viruses that live on bacteria are nowadays considered as the best biocontrol agents. They are used as replacers of antibiotics; food industry promoter; guard of aquatic life as well as of plants; pre-slaughter treatment agents; Generally Recognized As Safe (GRAS) food additives; Typing agent of bacteria; active tool of super bug therapy; in post harvest crops and food and during post infection and also to combat intracellular pathogens viz. Mycobacteria and Mycoplasma. Cyanophages/phycophages are particularly useful in controlling blooms produced by various genera of algae and cyanobacteria. By performing centrifugation studies and based on electron microscopy certain virus like particles containing ds RNA have been confirmed as mycophages. They are well proven as threat to pathogenic fungi (both fungal hyphae and yeast). Those that infect yeasts are called zymophages. Virophages have exquisite specificity for their viral host, hence can extensively be used for genetic studies and can also act as evolutionary link. After the discovery of very first virophage till now, a total of 3

  16. Wonder world of phages: potential biocontrol agents safeguarding biosphere and health of animals and humans- current scenario and perspectives.

    PubMed

    Tiwari, Ruchi; Chakraborty, Sandip; Dhama, Kuldeep; Wani, Mohd Yaqoob; Kumar, Amit; Kapoor, Sanjay

    2014-02-01

    Darwin's theory of natural selection and concept of survival of fittest of Wallace is a universal truth which derives the force of life among all live entities on this biosphere. Issues regarding food safety along with increased drug resistance and emerging zoonotic infections have proved that multidisciplinary efforts are in demand for human and animal welfare. This has led to development of various novel therapies the list of which remains incomplete without mentioning about phages. Homologous and non-homologous recombination along with point mutation and addition of new genes play role in their evolution. The rapid emergence of the antibiotic resistant strains of bacteria have created keen interest in finding necessary alternatives to check microbial infections and there comes the importance of phages. Phages kill the bacteria either by lysis or by releasing holins. Bacteriophages; the viruses that live on bacteria are nowadays considered as the best biocontrol agents. They are used as replacers of antibiotics; food industry promoter; guard of aquatic life as well as of plants; pre-slaughter treatment agents; Generally Recognized As Safe (GRAS) food additives; Typing agent of bacteria; active tool of super bug therapy; in post harvest crops and food and during post infection and also to combat intracellular pathogens viz. Mycobacteria and Mycoplasma. Cyanophages/phycophages are particularly useful in controlling blooms produced by various genera of algae and cyanobacteria. By performing centrifugation studies and based on electron microscopy certain virus like particles containing ds RNA have been confirmed as mycophages. They are well proven as threat to pathogenic fungi (both fungal hyphae and yeast). Those that infect yeasts are called zymophages. Virophages have exquisite specificity for their viral host, hence can extensively be used for genetic studies and can also act as evolutionary link. After the discovery of very first virophage till now, a total of 3

  17. Potential of osmoadaptation for improving Pantoea agglomerans E325 as biocontrol agent for fire blight of apple and pear

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea agglomerans biocontrol strain E325 is the active ingredient in a commercial product for fire blight, a destructive disease of apple and pear initiated by Erwinia amylovora in flowers. Osmoadaptation, involving the combination of saline osmotic stress and osmolyte amendment to growth media, w...

  18. Responses of yeast biocontrol agents to environmental stress.

    PubMed

    Sui, Yuan; Wisniewski, Michael; Droby, Samir; Liu, Jia

    2015-05-01

    Biological control of postharvest diseases, utilizing wild species and strains of antagonistic yeast species, is a research topic that has received considerable attention in the literature over the past 30 years. In principle, it represents a promising alternative to chemical fungicides for the management of postharvest decay of fruits, vegetables, and grains. A yeast-based biocontrol system is composed of a tritrophic interaction between a host (commodity), a pathogen, and a yeast species, all of which are affected by environmental factors such as temperature, pH, and UV light as well as osmotic and oxidative stresses. Additionally, during the production process, biocontrol agents encounter various severe abiotic stresses that also impact their viability. Therefore, understanding the ecological fitness of the potential yeast biocontrol agents and developing strategies to enhance their stress tolerance are essential to their efficacy and commercial application. The current review provides an overview of the responses of antagonistic yeast species to various environmental stresses, the methods that can be used to improve stress tolerance and efficacy, and the related mechanisms associated with improved stress tolerance.

  19. Responses of Yeast Biocontrol Agents to Environmental Stress

    PubMed Central

    Sui, Yuan; Wisniewski, Michael; Droby, Samir

    2015-01-01

    Biological control of postharvest diseases, utilizing wild species and strains of antagonistic yeast species, is a research topic that has received considerable attention in the literature over the past 30 years. In principle, it represents a promising alternative to chemical fungicides for the management of postharvest decay of fruits, vegetables, and grains. A yeast-based biocontrol system is composed of a tritrophic interaction between a host (commodity), a pathogen, and a yeast species, all of which are affected by environmental factors such as temperature, pH, and UV light as well as osmotic and oxidative stresses. Additionally, during the production process, biocontrol agents encounter various severe abiotic stresses that also impact their viability. Therefore, understanding the ecological fitness of the potential yeast biocontrol agents and developing strategies to enhance their stress tolerance are essential to their efficacy and commercial application. The current review provides an overview of the responses of antagonistic yeast species to various environmental stresses, the methods that can be used to improve stress tolerance and efficacy, and the related mechanisms associated with improved stress tolerance. PMID:25710368

  20. Draft Genome Sequences of Pseudomonas fluorescens Strains SF39a and SF4c, Potential Plant Growth Promotion and Biocontrol Agents

    PubMed Central

    Ly, Lindsey K.; Underwood, Grace E.; McCully, Lucy M.; Bitzer, Adam S.; Godino, Agustina; Bucci, Vanni; Brigham, Christopher J.; Príncipe, Analía; Fischer, Sonia E.

    2015-01-01

    Pseudomonas fluorescens SF4c and SF39a, strains isolated from wheat rhizosphere, have potential applications in plant growth promotion and biocontrol of fungal diseases of crop plants. We report the draft genome sequences of SF4c and SF39a with estimated sizes of 6.5 Mb and 5.9 Mb, respectively. PMID:25814613

  1. Draft Genome Sequences of Pseudomonas fluorescens Strains SF39a and SF4c, Potential Plant Growth Promotion and Biocontrol Agents.

    PubMed

    Ly, Lindsey K; Underwood, Grace E; McCully, Lucy M; Bitzer, Adam S; Godino, Agustina; Bucci, Vanni; Brigham, Christopher J; Príncipe, Analía; Fischer, Sonia E; Silby, Mark W

    2015-03-26

    Pseudomonas fluorescens SF4c and SF39a, strains isolated from wheat rhizosphere, have potential applications in plant growth promotion and biocontrol of fungal diseases of crop plants. We report the draft genome sequences of SF4c and SF39a with estimated sizes of 6.5 Mb and 5.9 Mb, respectively.

  2. Assessment of the potential of competitor snails and African catfish (Clarias gariepinus) as biocontrol agents against snail hosts transmitting schistosomiasis.

    PubMed

    Gashaw, Fikru; Erko, Berhanu; Teklehaymanot, Tilahun; Habtesellasie, Redeat

    2008-08-01

    The objective of this study was to assess the potential of the snails Physa acuta and Melanoides tuberculata and the African catfish Clarias gariepinus as biological control agents against the Schistosoma mansoni intermediate host Biomphalaria pfeifferi under laboratory conditions. Groups of five target and five competitor snails were raised together in experimental aquaria and same number in separate aquaria as controls. Shell size, number of eggs and mortality rate were recorded for twelve consecutive weeks. The stocking density for C. gariepinus was one fish per aquarium. Fish were provided with adequate or inadequate supplementary food and fifteen B. pfeifferi were added to each aquarium. The snails and their eggs were counted daily. Significant differences in shell growth and fecundity were noted between B. pfeifferi and M. tuberculata. Physa acuta was noted to be voracious in food consumption. Snail consumption was faster by fish provided with inadequate supplementary food. Based on the present findings, it is suggested that the two competitor snails and African catfish could be used as biological control agents against B. pfeifferi. Nevertheless, the susceptibility of the competitor snails to other trematodes in Ethiopia must first be ruled out before introducing these snails into new habitats. Follow-up field observation and rigorous laboratory studies remain areas for further research.

  3. Biocontrol: Fungi as Nematode Control Agents

    PubMed Central

    Mankau, R.

    1980-01-01

    The fungal antagonists of nematodes consist of a great variety of organisms belonging to widely divergent orders and families of fungi. They include the nematode-trapping fungi, endoparasitic fungi, parasites of nematode eggs and cysts, and fungi which produce metabolites toxic to nematodes. The diversity, adaptations, and distribution of nematode-destroying fungi and taxonomic problems encountered in their study are reviewed. The importance of nemato-phagous fungi in soil biology, with special emphasis on their relationship to populations of plant-parasitic nematodes, is considered. While predacious fungi have long been investigated as possible biocontrol agents and have often exhibited spectacular results in vitro, their performance in field studies has generated little enthusiasm among nematologists. To date no species has demonstrated control of any plant pest to a degree achieved with nematicides, but recent studies have provided a much clearer concept of possibilities and problems in the applied use of fungal antagonists. The discovery of new species, which appear to control certain pests effectively under specific conditions, holds out some promise that fungi may be utilized as alternatives to chemical control after a more thorough and expanded study of their biology and ecology. PMID:19300699

  4. Influence of container design on predation rate of potential biocontrol agent, Toxorhynchites splendens (Diptera: Culicidae) against dengue vector.

    PubMed

    Mohamad, N; Zuharah, W F

    2014-03-01

    Toxorhynchites splendens larvae are a natural predator of dengue vector mosquito larvae, Aedes albopictus. This study was carried out to evaluate the predation rate of Tx. splendens third instar larvae on Ae. albopictus larvae in 24 h. Each predator was offered prey at a density between 10 to 50 individuals. Predation rate of Tx. splendens were also tested with two manipulated factors; various types of container and different water volumes. The experiment was evaluated in man-made containers (tin cans, plastic drinking glasses and rubber tires) and natural container (bamboo stumps) which were filled with different water volumes (full, half full, 1/4 full, and 1/8 full). The prey density and the characteristics of the container were found as significant factors which influence the predation rate of Tx. splendens. The predator consumed significantly more prey at higher prey densities (40 and 50 preys) compared to the lowest density (10 preys) (F=3.935, df=4, p=0.008). The results showed significantly higher consumption in horizontal shaped container of rubber tire than in vertical shape of bamboo stumps (F=3.100, df=3, p=0.029). However, the water volume had no significant effect on predation rate of Tx. splendens (F=1.736, df=3, p=0.162). We generally suggest that Tx. splendens is best to be released in discarded tires or any other containers with horizontal shape design with wide opening since Tx. splendens can become more effective in searching prey in this type of container design. This predator is also a suitable biocontrol candidates to be introduced either in wet and dry seasons in Malaysia.

  5. Phyllostictines A-D, Oxazatricycloalkenones Produced by Phyllosticta cirsii, A Potential Mycoherbicide for Cirsium arvense Biocontrol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phyllosticta cirsii, a fungal pathogen isolated from Cirsium arvense and proposed as biocontrol agent of this noxious perennial weed, produces in liquid cultures different phytotoxic metabolites with potential herbicidal activity. Four new oxazatricycloalkenones, named phyllostictines A-D, were isol...

  6. Molecular analysis of faecal samples from birds to identify potential crop pests and useful biocontrol agents in natural areas.

    PubMed

    King, R A; Symondson, W O C; Thomas, R J

    2015-06-01

    Wild habitats adjoining farmland are potentially valuable sources of natural enemies, but also of pests. Here we tested the utility of birds as 'sampling devices', to identify the diversity of prey available to predators and particularly to screen for pests and natural enemies using natural ecosystems as refugia. Here we used PCR to amplify prey DNA from three sympatric songbirds foraging on small invertebrates in Phragmites reedbed ecosystems, namely the Reed Warbler (Acrocephalus scirpaceus), Sedge Warbler (Acrocephalus schoenobaenus) and Cetti's Warbler (Cettia cetti). A recently described general invertebrate primer pair was used for the first time to analyse diets. Amplicons were cloned and sequenced, then identified by reference to the Barcoding of Life Database and to our own sequences obtained from fresh invertebrates. Forty-five distinct prey DNA sequences were obtained from 11 faecal samples, of which 39 could be identified to species or genus. Targeting three warbler species ensured that species-specific differences in prey choice broadened the range of prey taken. Amongst the prey found in reedbeds were major pests (including the tomato moth Lacanobia oleracea) as well as many potentially valuable natural enemies including aphidophagous hoverflies and braconid wasps. Given the mobility of birds, this approach provides a practical way of sampling a whole habitat at once, providing growers with information on possible invasion by locally resident pests and the colonization potential of natural enemies from local natural habitats. PMID:25572526

  7. Typhlodromus pyri and Euseius finlandicus (Acari: Phytoseiidae) as potential biocontrol agents against spider mites (Acari: Tetranychidae) inhabiting willows: laboratory studies on predator development and reproduction on four diets.

    PubMed

    Puchalska, Ewa K; Kozak, Marcin

    2016-01-01

    Typhlodromus pyri Scheuten and Euseius finlandicus (Oudemans) are important predators of phytophagous mites. The present laboratory study aimed to determine whether both species can develop and reach maturity feeding on spider mites occurring on willows, i.e., Schizotetranychus schizopus (Zacher), Schizotetranychus garmani Pritchard & Baker, and Tetranychus urticae Koch, and on Brassica napus L. pollen. The predators' development, reproduction and demographic parameters were significantly affected by diet. The data suggest that rape pollen can be useful in mass rearing of E. finlandicus but is completely unsuitable as alternative food for T. pyri. Short development time and high values of population parameters achieved by T. pyri feeding on larvae and protonymphs of S. schizopus and by E. finlandicus feeding on juvenile stages of S. garmani indicate great suitability of these preys as food for the phytoseiids, and make both predatory species promising biocontrol agents in spider mite control on willows.

  8. Typhlodromus pyri and Euseius finlandicus (Acari: Phytoseiidae) as potential biocontrol agents against spider mites (Acari: Tetranychidae) inhabiting willows: laboratory studies on predator development and reproduction on four diets.

    PubMed

    Puchalska, Ewa K; Kozak, Marcin

    2016-01-01

    Typhlodromus pyri Scheuten and Euseius finlandicus (Oudemans) are important predators of phytophagous mites. The present laboratory study aimed to determine whether both species can develop and reach maturity feeding on spider mites occurring on willows, i.e., Schizotetranychus schizopus (Zacher), Schizotetranychus garmani Pritchard & Baker, and Tetranychus urticae Koch, and on Brassica napus L. pollen. The predators' development, reproduction and demographic parameters were significantly affected by diet. The data suggest that rape pollen can be useful in mass rearing of E. finlandicus but is completely unsuitable as alternative food for T. pyri. Short development time and high values of population parameters achieved by T. pyri feeding on larvae and protonymphs of S. schizopus and by E. finlandicus feeding on juvenile stages of S. garmani indicate great suitability of these preys as food for the phytoseiids, and make both predatory species promising biocontrol agents in spider mite control on willows. PMID:26530991

  9. Streptomyces rochei ACTA1551, an Indigenous Greek Isolate Studied as a Potential Biocontrol Agent against Fusarium oxysporum f.sp. lycopersici

    PubMed Central

    Kanini, Grammatiki S.; Katsifas, Efstathios A.; Savvides, Alexandros L.; Karagouni, Amalia D.

    2013-01-01

    Many studies have shown that several Greek ecosystems inhabit very interesting bacteria with biotechnological properties. Therefore Streptomyces isolates from diverse Greek habitats were selected for their antifungal activity against the common phytopathogenic fungus Fusarium oxysporum. The isolate encoded ACTA1551, member of Streptomyces genus, could strongly suppress the fungal growth when examined in antagonistic bioassays in vitro. The isolate was found phylogenetically relative to Streptomyces rochei after analyzing its 16S rDNA sequence. The influence of different environmental conditions, such as medium composition, temperature, and pH on the expression of the antifungal activity was thoroughly examined. Streptomyces rochei ACTA1551 was able to protect tomato seeds from F. oxysporum infection in vivo while it was shown to promote the growth of tomato plants when the pathogen was absent. In an initial effort towards the elucidation of the biochemical and physiological nature of ACTA1551 antifungal activity, extracts from solid streptomycete cultures under antagonistic or/and not antagonistic conditions were concentrated and fractionated. The metabolites involved in the antagonistic action of the isolate showed to be more than one and produced independently of the presence of the pathogen. The above observations could support the application of Streptomyces rochei ACTA1551 as biocontrol agent against F. oxysporum. PMID:23762841

  10. Exploring antagonistic metabolites of established biocontrol agent of marine origin.

    PubMed

    Rane, Makarand Ramesh; Sarode, Prashant Diwakar; Chaudhari, Bhushan Liladhar; Chincholkar, Sudhir Bhaskarrao

    2008-12-01

    Biocontrol ability of Pseudomonas aeruginosa ID 4365, a biocontrol agent of groundnut phytopathogens from marine origin, was previously attributed to the production of pyoverdin type of siderophores. However, pyoverdin-rich supernatants of this organism showed better antifungal activity compared to equivalent amount of purified pyoverdin indicating presence of undetected metabolite(s) in pyoverdin rich supernatants. On the basis of observation that antagonistic activity was iron-dependent and iron-independent, an attempt was made to detect the presence of additional metabolites. In addition to pyoverdin, strain produced additional siderophores, viz. pyochelin and salicylic acid. Two broad spectrum antifungal compounds, viz. pyocyanin and phenazine-1-carboxylic acid, were detected, characterized, and activity against phytopathogens was demonstrated. Iron- and phosphate-dependent co-production of siderophores and phenazines was confirmed. Strain showed additional features like production of hydrogen cyanide, indol-3-acetic acid, and phosphate solubilization. PMID:18626581

  11. Anti-phytopathogen potential of endophytic actinobacteria isolated from tomato plants (Lycopersicon esculentum) in southern Brazil, and characterization of Streptomyces sp. R18(6), a potential biocontrol agent.

    PubMed

    de Oliveira, Margaroni Fialho; da Silva, Mariana Germano; Van Der Sand, Sueli T

    2010-09-01

    Tomato plants (Lycopersicon esculentum) are highly susceptible to phytopathogen attack. The resulting intensive application of pesticides on tomato crops can affect the environment and health of humans and animals. The objective of this study was to select potential biocontrol agents among actinobacteria from tomato plants, in a search for alternative phytopathogen control. We evaluated 70 endophytic actinobacteria isolated from tomato plants in southern Brazil, testing their antimicrobial activity, siderophore production, indoleacetic acid production, and phosphate solubility. The actinomycete isolate with the highest antimicrobial potential was selected using the agar-well diffusion method, in order to optimize conditions for the production of compounds with antimicrobial activity. For this study, six growth media (starch casein-SC, ISP2, Bennett's, Sahin, Czapek-Dox, and TSB), three temperatures (25 degrees C, 30 degrees C, and 35 degrees C) and different pH were tested. Of the actinobacteria tested, 88.6% showed antimicrobial activity against at least one phytopathogen, 72.1% showed a positive reaction for indoleacetic acid production, 86.8% produced siderophores and 16.2% showed a positive reaction for phosphate solubility. Isolate R18(6) was selected due to its antagonistic activity against all phytopathogenic microorganisms tested in this study. The best conditions for production were observed in the SC medium, at 30 degrees C and pH 7.0. The isolate R18(6) showed close biochemical and genetic similarity to Streptomyces pluricolorescens. PMID:20542109

  12. Anti-phytopathogen potential of endophytic actinobacteria isolated from tomato plants (Lycopersicon esculentum) in southern Brazil, and characterization of Streptomyces sp. R18(6), a potential biocontrol agent.

    PubMed

    de Oliveira, Margaroni Fialho; da Silva, Mariana Germano; Van Der Sand, Sueli T

    2010-09-01

    Tomato plants (Lycopersicon esculentum) are highly susceptible to phytopathogen attack. The resulting intensive application of pesticides on tomato crops can affect the environment and health of humans and animals. The objective of this study was to select potential biocontrol agents among actinobacteria from tomato plants, in a search for alternative phytopathogen control. We evaluated 70 endophytic actinobacteria isolated from tomato plants in southern Brazil, testing their antimicrobial activity, siderophore production, indoleacetic acid production, and phosphate solubility. The actinomycete isolate with the highest antimicrobial potential was selected using the agar-well diffusion method, in order to optimize conditions for the production of compounds with antimicrobial activity. For this study, six growth media (starch casein-SC, ISP2, Bennett's, Sahin, Czapek-Dox, and TSB), three temperatures (25 degrees C, 30 degrees C, and 35 degrees C) and different pH were tested. Of the actinobacteria tested, 88.6% showed antimicrobial activity against at least one phytopathogen, 72.1% showed a positive reaction for indoleacetic acid production, 86.8% produced siderophores and 16.2% showed a positive reaction for phosphate solubility. Isolate R18(6) was selected due to its antagonistic activity against all phytopathogenic microorganisms tested in this study. The best conditions for production were observed in the SC medium, at 30 degrees C and pH 7.0. The isolate R18(6) showed close biochemical and genetic similarity to Streptomyces pluricolorescens.

  13. Identification of Biocontrol Agents to Control the Fungal Pathogen, Geomyces destructans, in Bats

    NASA Astrophysics Data System (ADS)

    Braunstein, S.; Cheng, T.

    2013-12-01

    The fungal pathogen Geomyces destructans (Gd) causes the disease White-nose Syndrome (WNS) in bats and is estimated to have killed millions of bats since its emergence in North America in 2006. Gd is predicted to cause the local extinction of at least three bat species if rates of decline continue unabated. Given the devastating impacts of Gd to bat populations, identifying a viable method for controlling the pathogen is pertinent for conservation of affected bat species. Our work focuses on identifying naturally-occurring skin bacteria on bats that are antagonistic to Gd that could potentially be used as a biocontrol. We cultured bacteria from skin swabs taken from wild bats (Myotis lucifugus, Eptesicus fuscus, Myotis sodalis, Perimyotis subflavus). We conducted challenge experiments to identify bacterial strains that inhibited Gd growth. Bacteria that exhibited antifungal properties were identified using 16S and gyrB markers. Our methods identified several bacteria in the Pseudomonas fluorescens complex as potential biocontrol agents. Future work will continue to test the viability of these bacteria as biocontrol agents via experimental treatments with live captive bats. The failure of previous non-biocontrol methods highlights the importance of developing these bacteria as a biologically-friendly method for controlling Gd. A bat infected with Geomyces destructans. Photo by West Virginia Division of Natural Resources Bacterial culture from the swab of a bat's wings

  14. Evaluation of the sea anemone Anthothoe albocincta as an augmentative biocontrol agent for biofouling on artificial structures.

    PubMed

    Atalah, Javier; Bennett, Holly; Hopkins, Grant A; Forrest, Barrie M

    2013-01-01

    Augmentative biocontrol, defined as the use of indigenous natural enemies to control pest populations, has not been explored extensively in marine systems. This study tested the potential of the anemone Anthothoe albocincta as a biocontrol agent for biofouling on submerged artificial structures. Biofouling biomass was negatively related to anemone cover. Treatments with high anemone cover (>35%) led to significant changes in biofouling assemblages compared to controls. Taxa that contributed to these changes differed among sites, but included reductions in cover of problematic fouling organisms, such as solitary ascidians and bryozoans. In laboratory trials, A. albocincta substantially prevented the settlement of larvae of the bryozoan Bugula neritina when exposed to three levels of larval dose, suggesting predation as an important biocontrol mechanism, in addition to space pre-emption. This study demonstrated that augmentative biocontrol using anemones has the potential to reduce biofouling on marine artificial structures, although considerable further work is required to refine this tool before its application.

  15. Induced systemic resistance and plant responses to fungal biocontrol agents.

    PubMed

    Shoresh, Michal; Harman, Gary E; Mastouri, Fatemeh

    2010-01-01

    Biocontrol fungi (BCF) are agents that control plant diseases. These include the well-known Trichoderma spp. and the recently described Sebacinales spp. They have the ability to control numerous foliar, root, and fruit pathogens and even invertebrates such as nematodes. However, this is only a subset of their abilities. We now know that they also have the ability to ameliorate a wide range of abiotic stresses, and some of them can also alleviate physiological stresses such as seed aging. They can also enhance nutrient uptake in plants and can substantially increase nitrogen use efficiency in crops. These abilities may be more important to agriculture than disease control. Some strains also have abilities to improve photosynthetic efficiency and probably respiratory activities of plants. All of these capabilities are a consequence of their abilities to reprogram plant gene expression, probably through activation of a limited number of general plant pathways.

  16. Combined use of biocontrol agents to manage plant diseases in theory and practice.

    PubMed

    Xu, X-M; Jeffries, P; Pautasso, M; Jeger, M J

    2011-09-01

    Effective use of biological control agents (BCAs) is a potentially important component of sustainable agriculture. Recently, there has been an increasing interest among researchers in using combinations of BCAs to exploit potential synergistic effects among them. The methodology for investigating such synergistic effects was reviewed first and published results were then assessed for available evidence for synergy. Correct formulation of hypotheses based on the theoretical definition of independence (Bliss independence or Loewe additivity) and the subsequent and statistical testing for the independence-synergistic-antagonistic interactions have rarely been carried out thus far in studies on biocontrol of plant diseases. Thus, caution must be taken when interpreting reported "synergistic" effects without assessing the original publications. Recent theoretical modeling work suggested that disease suppression from combined use of two BCAs was, in general, very similar to that achieved by the more efficacious one, indicating no synergistic but more likely antagonistic interactions. Only in 2% of the total 465 published treatments was there evidence for synergistic effects among BCAs. In the majority of the cases, antagonistic interactions among BCAs were indicated. Thus, both theoretical and experimental studies suggest that, in combined use of BCAs, antagonistic interactions among BCAs are more likely to occur than synergistic interactions. Several research strategies, including formulation of synergy hypotheses in relation to biocontrol mechanisms, are outlined to exploit microbial mixtures for uses in biocontrol of plant diseases.

  17. [Fungal bio-control agents against ixodid tick--a review].

    PubMed

    Sun, Ming; Wang, Xiaoyan; Luo, Jianxun

    2012-08-01

    Entomopathogenic fungi as potential agents for bio-control have been widely applied in the control of insect pests in agriculture. However, the application remains in laboratory scale for the control of ectoparasites. Owing to the need to combat the short lasting period of chemical acaricides and reduction of pollution, it is urgent to develop sufficient, stable and safe measures for tick control. We reviewed the primary scientific achievements in utilization of environmental microbes for controlling of ticks. Studies conducted in this field may benefit to sustainable development, environmental protection, maintaining ecological balance and production of green products.

  18. Commercialization and implementation of biocontrol.

    PubMed

    Fravel, D R

    2005-01-01

    Although the number of biocontrol products is increasing, these products still represent only about 1% of agricultural chemical sales. Yet these are important contributions because biocontrol agents offer disease management alternatives with different mechanisms of action than chemical pesticides. Trends in research include the increased use of biorational screening processes to identify microorganisms with potential for biocontrol, increased testing under semicommercial and commercial production conditions, increased emphasis on combining biocontrol strains with each other and with other control methods, integrating biocontrol into an overall system.

  19. Combinations of Biocontrol Agents for Management of Plant-Parasitic Nematodes and Soilborne Plant-Pathogenic Fungi

    PubMed Central

    Meyer, Susan L. F.; Roberts, Daniel P.

    2002-01-01

    Numerous microbes are antagonistic to plant-parasitic nematodes and soilborne plant-pathogenic fungi, but few of these organisms are commercially available for management of these pathogens. Inconsistent performance of applied biocontrol agents has proven to be a primary obstacle to the development of successful commercial products. One of the strategies for overcoming inconsistent performance is to combine the disease-suppressive activity of two (or more) beneficial microbes in a biocontrol preparation. Such combinations have potential for more extensive colonization of the rhizosphere, more consistent expression of beneficial traits under a broad range of soil conditions, and antagonism to a larger number of plant pests or pathogens than strains applied individually. Conversely, microbes applied in combination also may have antagonistic interactions with each other. Increased, decreased, and unaltered suppression of the target pathogen or pest has been observed when biocontrol microbes have been applied in combination. Unfortunately, the ecological basis for increased or decreased suppression has not been determined in many cases and needs further consideration. The complexity of interactions involved in the application of multiple organisms for biological control has slowed progress toward development of successful formulations. However, this approach has potential for overcoming some of the efficacy problems that occur with application of individual biocontrol agents. PMID:19265899

  20. Lactic acid bacteria from fresh fruit and vegetables as biocontrol agents of phytopathogenic bacteria and fungi.

    PubMed

    Trias, Rosalia; Bañeras, Lluís; Montesinos, Emilio; Badosa, Esther

    2008-12-01

    This study evaluated the efficacy of lactic acid bacteria (LAB) isolated from fresh fruits and vegetables as biocontrol agents against the phytopathogenic and spoilage bacteria and fungi, Xanthomonas campestris, Erwinia carotovora, Penicillium expansum, Monilinia laxa, and Botrytis cinerea. The antagonistic activity of 496 LAB strains was tested in vitro and all tested microorganisms except P. expansum were inhibited by at least one isolate. The 496 isolates were also analyzed for the inhibition of P. expansum infection in wounds of Golden Delicious apples. Four strains (TC97, AC318, TM319, and FF441) reduced the fungal rot diameter of the apples by 20%; only Weissella cibaria strain TM128 decreased infection levels by 50%. Cell-free supernatants of selected antagonistic bacteria were studied to determine the nature of the antimicrobial compounds produced. Organic acids were the preferred mediators of inhibition but hydrogen peroxide was also detected when strains BC48, TM128, PM141 and FF441 were tested against E. carotovora. While previous reports of antifungal activity by LAB are scarce, our results support the potential of LAB as biocontrol agents against postharvest rot.

  1. Lactic acid bacteria from fresh fruit and vegetables as biocontrol agents of phytopathogenic bacteria and fungi.

    PubMed

    Trias, Rosalia; Bañeras, Lluís; Montesinos, Emilio; Badosa, Esther

    2008-12-01

    This study evaluated the efficacy of lactic acid bacteria (LAB) isolated from fresh fruits and vegetables as biocontrol agents against the phytopathogenic and spoilage bacteria and fungi, Xanthomonas campestris, Erwinia carotovora, Penicillium expansum, Monilinia laxa, and Botrytis cinerea. The antagonistic activity of 496 LAB strains was tested in vitro and all tested microorganisms except P. expansum were inhibited by at least one isolate. The 496 isolates were also analyzed for the inhibition of P. expansum infection in wounds of Golden Delicious apples. Four strains (TC97, AC318, TM319, and FF441) reduced the fungal rot diameter of the apples by 20%; only Weissella cibaria strain TM128 decreased infection levels by 50%. Cell-free supernatants of selected antagonistic bacteria were studied to determine the nature of the antimicrobial compounds produced. Organic acids were the preferred mediators of inhibition but hydrogen peroxide was also detected when strains BC48, TM128, PM141 and FF441 were tested against E. carotovora. While previous reports of antifungal activity by LAB are scarce, our results support the potential of LAB as biocontrol agents against postharvest rot. PMID:19204894

  2. Biocontrol potential of Trichoderma harzianum isolate T-aloe against Sclerotinia sclerotiorum in soybean.

    PubMed

    Zhang, Fuli; Ge, Honglian; Zhang, Fan; Guo, Ning; Wang, Yucheng; Chen, Long; Ji, Xiue; Li, Chengwei

    2016-03-01

    Sclerotinia stem rot, caused by Sclerotinia sclerotiorum (Lib.) de Bary is a major disease of soybean (Glycine max (L.) Merr.). At present, we revealed the three-way interaction between Trichoderma harzianum T-aloe, pathogen S. sclerotiorum and soybean plants in order to demonstrate biocontrol mechanism and evaluate biocontrol potential of T-aloe against S. sclerotiorum in soybean. In our experiments, T-aloe inhibited the growth of S. sclerotiorum with an efficiency of 56.3% in dual culture tests. T-aloe hyphae grew in parallel or intertwined with S. sclerotiorum hyphae and produced hooked contact branches, indicating mycoparasitism. Plate tests showed that T-aloe culture filtrate inhibited S. sclerotiorum growth with an inhibition efficiency of 51.2% and sclerotia production. T-aloe pretreatment showed growth-promoting effect on soybean plants. The activities of peroxidase, superoxide dismutase, and catalase increased, and the hydrogen peroxide (H2O2) as well as the superoxide radical (O2(-)) content in soybean leaves decreased after T-aloe pretreatment in response to S. sclerotiorum pathogen challenge. T-aloe treatment diminished damage caused by pathogen stress on soybean leaf cell membrane, and increased chlorophyll as well as total phenol contents. The defense-related genes PR1, PR2, and PR3 were expressed in the leaves of T-aloe-treated plants. In summary, T-aloe displayed biocontrol potential against S. sclerotiorum. This is the first report of unraveling biocontrol potential of Trichoderma Spp. to soybean sclerotinia stem rot from the three-way interaction between the biocontrol agent, pathogen S. sclerotiorum and soybean plants. PMID:26774866

  3. Integrated effect of gamma radiation and biocontrol agent on quality parameters of apple fruit: An innovative commercial preservation method

    NASA Astrophysics Data System (ADS)

    Ahari Mostafavi, Hossein; Mahyar Mirmajlessi, Seyed; Fathollahi, Hadi; Shahbazi, Samira; Mohammad Mirjalili, Seyed

    2013-10-01

    Effects of gamma irradiation and biocontrol agent (Pseudomonas fluorescens) on the physico-chemical parameters (including moisture, total soluble solids, antioxidant activity, phenolic content and firmness) of cv. Golden Delicious apples were investigated for their ability to avoid the post-harvest blue mold caused by Penicillium expansum during cold storage. Freshly harvested apples were inoculated with P. expansum. Treated fruits were irradiated at doses of 0, 200, 400, 600 and 800 Gy and then inoculated with P. fluorescens suspension. Samples were evaluated at 3 month intervals. The results demonstrated a clear link between antioxidant activity and phenolic content, so that dose range of 200-400 Gy significantly increased phenolic content and antioxidant activity. Effect of P. fluorescens was similar to irradiation at 200 and 400 Gy that could prevent lesion diameter in pathogen-treated apples. As dose and storage time increased firmness decreased but, combination of P. fluorescens as well as irradiation (at 200-400 Gy) could decrease softening apple fruits during storage. In all parameters, P. fluorescens (as biocontrol agent) inhibited P. expansum similar to irradiation at 200-400 Gy. So, integrated treatment of irradiation and biocontrol agent explored the potential dual benefit of low doses (200 and 400 Gy) as a suitable method to sustain physico-chemical quality and conclusively reduce apple fruits losses during post-harvest preservation.

  4. Evaluation of yeasts obtained from Antarctic soil samples as biocontrol agents for the management of postharvest diseases of apple (Malus × domestica).

    PubMed

    Vero, Silvana; Garmendia, Gabriela; González, M Belén; Bentancur, Oscar; Wisniewski, Michael

    2013-03-01

    Psychrotrophic yeasts were isolated from Antarctic soils, selected based on their ability to grow in apple juice at low temperatures, and were evaluated as potential biocontrol agents for the management of postharvest diseases of apple during cold storage. Among the species recovered, an isolate of Leucosporidium scottii, designated At17, was identified as a good biocontrol agent for blue and gray mold of two apple cultivars. The selected isolate produced soluble and volatile antifungal substances that were inhibitory to apple pathogens. Siderophore production was also demonstrated, but it did not appear to play a role in pathogen inhibition. The selected yeast had the capacity to form a biofilm when grown in apple juice, which is considered an important attribute of postharvest antagonists to successfully colonize wounds and intact fruit surfaces. At17 was resistant to commonly used postharvest fungicides, so application of a combination of low-dose fungicide along with the biocontrol agent could be used as an integrated management practice.

  5. Evaluation of yeasts obtained from Antarctic soil samples as biocontrol agents for the management of postharvest diseases of apple (Malus x domestica)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Psychrotrophic yeasts isolated from soils collected in Antarctica and selected by its capacity of growing in apple juice at low temperatures were evaluated for their potential as biocontrol agents for the management of postharvest diseases of apple during cold storage. Among the species recovered, ...

  6. Native isolate of Trichoderma: a biocontrol agent with unique stress tolerance properties.

    PubMed

    Mishra, N; Khan, S S; Sundari, S Krishna

    2016-08-01

    Species of Trichoderma are widely recognized for their biocontrol abilities, but seldom studied collectively, for their plant growth promotion, abiotic stress tolerance and bioremediation properties. Our study is a concentrated effort to establish the potential of native isolate Trichoderma harzianum KSNM (T103) to tolerate biotic (root pathogens) and abiotic stresses [high salt (100-1000 mM); heavy metal (chromium, nickel and zinc: 1-10 mM); pesticides: malathion (100-600 ppm), carbofuran (100-600 ppb)], along with its ability to support plant growth. In vitro growth promotion assays with T103 treated Vigna radiata, Vigna mungo and Hordeum vulgare confirmed 'non-species specific' growth promotion effects of T103. At lower metal concentration, T103 treatment was found to completely negate the impact of metal stress [60 % increase in radicle length (RL) with no significant decrease in %germination (%G)]. Even at 10 mM metal, T103 inoculation gave 80 % increase in %G and >50 % increase in RL. In vitro experiments confirmed high metal reduction capacity (47 %-Cr, 35 %-Ni and 42 %-Zn) of T103 at concentrations as high as 4 mM. At maximum residual concentrations of malathion (440 ppm) and carbofuran (100 ppb) reported in agricultural soils, T103 maintained 80 and 100 % survivability, respectively. T103 treatment has improved %G and RL in all three hosts challenged with pesticide. Isolate T103 was found to effectively suppress growth of three major root pathogens: Macrophomina phaseolina (65.83 %) followed by Sclerotium rolfsii (19.33 %) and Fusarium oxysporum (19.18 %). In the light of these observations, native T. harzianum (T103) seems to be a competent biocontrol agent for tropical agricultural soils contaminated with residual pesticides and heavy metals.

  7. Native isolate of Trichoderma: a biocontrol agent with unique stress tolerance properties.

    PubMed

    Mishra, N; Khan, S S; Sundari, S Krishna

    2016-08-01

    Species of Trichoderma are widely recognized for their biocontrol abilities, but seldom studied collectively, for their plant growth promotion, abiotic stress tolerance and bioremediation properties. Our study is a concentrated effort to establish the potential of native isolate Trichoderma harzianum KSNM (T103) to tolerate biotic (root pathogens) and abiotic stresses [high salt (100-1000 mM); heavy metal (chromium, nickel and zinc: 1-10 mM); pesticides: malathion (100-600 ppm), carbofuran (100-600 ppb)], along with its ability to support plant growth. In vitro growth promotion assays with T103 treated Vigna radiata, Vigna mungo and Hordeum vulgare confirmed 'non-species specific' growth promotion effects of T103. At lower metal concentration, T103 treatment was found to completely negate the impact of metal stress [60 % increase in radicle length (RL) with no significant decrease in %germination (%G)]. Even at 10 mM metal, T103 inoculation gave 80 % increase in %G and >50 % increase in RL. In vitro experiments confirmed high metal reduction capacity (47 %-Cr, 35 %-Ni and 42 %-Zn) of T103 at concentrations as high as 4 mM. At maximum residual concentrations of malathion (440 ppm) and carbofuran (100 ppb) reported in agricultural soils, T103 maintained 80 and 100 % survivability, respectively. T103 treatment has improved %G and RL in all three hosts challenged with pesticide. Isolate T103 was found to effectively suppress growth of three major root pathogens: Macrophomina phaseolina (65.83 %) followed by Sclerotium rolfsii (19.33 %) and Fusarium oxysporum (19.18 %). In the light of these observations, native T. harzianum (T103) seems to be a competent biocontrol agent for tropical agricultural soils contaminated with residual pesticides and heavy metals. PMID:27339311

  8. Selection rhizosphere-competent microbes for development of microbial products as biocontrol agents

    NASA Astrophysics Data System (ADS)

    Mashinistova, A. V.; Elchin, A. A.; Gorbunova, N. V.; Muratov, V. S.; Kydralieva, K. A.; Khudaibergenova, B. M.; Shabaev, V. P.; Jorobekova, Sh. J.

    2009-04-01

    Rhizosphere-borne microorganisms reintroduced to the soil-root interface can establish without inducing permanent disturbance in the microbial balance and effectively colonise the rhizosphere due to carbon sources of plant root exudates. A challenge for future development of microbial products for use in agriculture will be selection of rhizosphere-competent microbes that both protect the plant from pathogens and improve crop establishment and persistence. In this study screening, collection, identification and expression of stable and technological microbial strains living in soils and in the rhizosphere of abundant weed - couch-grass Elytrigia repens L. Nevski were conducted. A total of 98 bacteria isolated from the rhizosphere were assessed for biocontrol activity in vitro against phytopathogenic fungi including Fusarium culmorum, Fusarium heterosporum, Fusarium oxysporum, Drechslera teres, Bipolaris sorokiniana, Piricularia oryzae, Botrytis cinerea, Colletothrichum atramentarium and Cladosporium sp., Stagonospora nodorum. Biocontrol activity were performed by the following methods: radial and parallel streaks, "host - pathogen" on the cuts of wheat leaves. A culture collection comprising 64 potential biocontrol agents (BCA) against wheat and barley root diseases has been established. Of these, the most effective were 8 isolates inhibitory to at least 4 out of 5 phytopathogenic fungi tested. The remaining isolates inhibited at least 1 of 5 fungi tested. Growth stimulating activity of proposed rhizobacteria-based preparations was estimated using seedling and vegetative pot techniques. Seeds-inoculation and the tests in laboratory and field conditions were conducted for different agricultural crops - wheat and barley. Intact cells, liquid culture filtrates and crude extracts of the four beneficial bacterial strains isolated from the rhizosphere of weed were studied to stimulate plant growth. As a result, four bacterial strains selected from rhizosphere of weed

  9. Plot- and landscape-level changes in climate and vegetation following defoliation of exotic saltcedar (Tamarix sp.) from the biocontrol agent Diorhabda carinulata along a stream in the Mojave Desert (USA)

    USGS Publications Warehouse

    Bateman, H.L.; Nagler, P.L.; Glenn, E.P.

    2013-01-01

    The biocontrol agent, northern tamarisk beetle (Diorhabda carinulata), has been used to defoliate non-native saltcedar (Tamarix spp.) in USA western riparian systems since 2001. Biocontrol has the potential to impact biotic communities and climatic conditions in affected riparian areas. To determine the relationships between biocontrol establishment and effects on vegetation and climate at the plot and landscape scales, we measured temperature, relative humidity, foliage canopy, solar radiation, and used satellite imagery to assess saltcedar defoliation and evapotranspiration (ET) along the Virgin River in the Mojave Desert. Following defoliation solar radiation increased, daily humidity decreased, and maximum daily temperatures tended to increase. MODIS and Landsat satellite imagery showed defoliation was widespread, resulting in reductions in ET and vegetation indices. Because biocontrol beetles are spreading into new saltcedar habitats on arid western rivers, and the eventual equilibrium between beetles and saltcedar is unknown, it is necessary to monitor trends for ecosystem functions and higher trophic-level responses in habitats impacted by biocontrol.

  10. Bio-prospecting of distillery yeasts as bio-control and bio-remediation agents.

    PubMed

    Ubeda, Juan F; Maldonado, María; Briones, Ana I; Francisco, J Fernández; González, Francisco J

    2014-05-01

    This work constitutes a preliminary study in which the capacity of non-Saccharomyces yeasts isolated from ancient distilleries as bio-control agents against moulds and in the treatment of waste waters contaminated by heavy metals-i.e. bio-remediation-is shown. In the first control assays, antagonist effect between non-Saccharomyces yeasts, their extracts and supernatants against some moulds, analysing the plausible (not exhaustive) involved factors were qualitatively verified. In addition, two enzymatic degrading properties of cell wall plant polymers, quitinolitic and pectinolitic, were screened. Finally, their use as agents of bio-remediation of three heavy metals (cadmium, chromium and lead) was analysed semi-quantitatively. The results showed that all isolates belonging to Pichia species effectively inhibited all moulds assayed. Moreover, P. kudriavzevii is a good candidate for both bio-control and bio-remediation because it inhibited moulds and accumulated the major proportion of the three tested metals. PMID:24370629

  11. Bio-prospecting of distillery yeasts as bio-control and bio-remediation agents.

    PubMed

    Ubeda, Juan F; Maldonado, María; Briones, Ana I; Francisco, J Fernández; González, Francisco J

    2014-05-01

    This work constitutes a preliminary study in which the capacity of non-Saccharomyces yeasts isolated from ancient distilleries as bio-control agents against moulds and in the treatment of waste waters contaminated by heavy metals-i.e. bio-remediation-is shown. In the first control assays, antagonist effect between non-Saccharomyces yeasts, their extracts and supernatants against some moulds, analysing the plausible (not exhaustive) involved factors were qualitatively verified. In addition, two enzymatic degrading properties of cell wall plant polymers, quitinolitic and pectinolitic, were screened. Finally, their use as agents of bio-remediation of three heavy metals (cadmium, chromium and lead) was analysed semi-quantitatively. The results showed that all isolates belonging to Pichia species effectively inhibited all moulds assayed. Moreover, P. kudriavzevii is a good candidate for both bio-control and bio-remediation because it inhibited moulds and accumulated the major proportion of the three tested metals.

  12. Tamarisk biocontrol using tamarisk beetles: Potential consequences for riparian birds in the southwestern United States

    USGS Publications Warehouse

    Paxton, E.H.; Theimer, T.C.; Sogge, M.K.

    2011-01-01

    The tamarisk beetle (Diorhabda spp.), a non-native biocontrol agent, has been introduced to eradicate tamarisk (Tamarix spp.), a genus of non-native tree that has become a dominant component of riparian woodlands in the southwestern United States. Tamarisk beetles have the potential to spread widely and defoliate large expanses of tamarisk habitat, but the effects of such a widespread loss of riparian vegetation on birds remains unknown. We reviewed literature on the effects of other defoliating insects on birds to investigate the potential for tamarisk beetles to affect birds positively or negatively by changing food abundance and vegetation structure. We then combined data on the temporal patterns of tamarisk defoliation by beetles with nest productivity of a wellstudied riparian obligate, the Southwestern Willow Flycatcher (Empidonax traillii extimus), to simulate the potential demographic consequences of beetle defoliation on breeding riparian birds in both the short and long term. Our results highlight that the effects of tamarisk biocontrol on birds will likely vary by species and population, depending upon its sensitivity to seasonal defoliation by beetles and net loss of riparian habitat due to tamarisk mortality. Species with restricted distributions that include areas dominated by tamarisk may be negatively affected both in the short and long term. The rate of regeneration and/or restoration of native cottonwoods (Populus spp.) and willows (Salix spp.) relative to the rate of tamarisk loss will be critical in determining the long-term effect of this large-scale ecological experiment. ?? The Cooper Ornithological Society 2011.

  13. Tamarisk biocontrol using tamarisk beetles: Potential consequences for riparian birds in the southwestern United States

    USGS Publications Warehouse

    Paxton, Eben H.; Theimer, Tad C.; Sogge, Mark K.

    2011-01-01

    The tamarisk beetle (Diorhabda spp.), a non-native biocontrol agent, has been introduced to eradicate tamarisk (Tamarix spp.), a genus of non-native tree that has become a dominant component of riparian woodlands in the southwestern United States. Tamarisk beetles have the potential to spread widely and defoliate large expanses of tamarisk habitat, but the effects of such a widespread loss of riparian vegetation on birds remains unknown. We reviewed literature on the effects of other defoliating insects on birds to investigate the potential for tamarisk beetles to affect birds positively or negatively by changing food abundance and vegetation structure. We then combined data on the temporal patterns of tamarisk defoliation by beetles with nest productivity of a well-studied riparian obligate, the Southwestern Willow Flycatcher (Empidonax traillii extimus), to simulate the potential demographic consequences of beetle defoliation on breeding riparian birds in both the short and long term. Our results highlight that the effects of tamarisk biocontrol on birds will likely vary by species and population, depending upon its sensitivity to seasonal defoliation by beetles and net loss of riparian habitat due to tamarisk mortality. Species with restricted distributions that include areas dominated by tamarisk may be negatively affected both in the short and long term. The rate of regeneration and/or restoration of native cottonwoods (Populus spp.) and willows (Salix spp.) relative to the rate of tamarisk loss will be critical in determining the long-term effect of this large-scale ecological experiment.

  14. Endemic plants harbour specific Trichoderma communities with an exceptional potential for biocontrol of phytopathogens.

    PubMed

    Zachow, Christin; Berg, Christian; Müller, Henry; Monk, Jana; Berg, Gabriele

    2016-10-10

    Trichoderma strains exhibit enormous potential for applications in biotechnology, in particular as biocontrol agents against pathogens. However, little is known about the diversity of plant-associated Trichoderma communities at a global scale and their antagonistic spectrum. In order to gather information about structure and function, we compared Trichoderma biomes of endemic (Aeonium, Diospyros, Hebe, Rhododendron) and cosmopolitan plants (Zea mays) in a global study encompassing the area Northwest Africa to New Zealand via the European Alps and Madagascar. At the quantitative level we found no differences between cosmopolitan and endemic plants. Statistically significant differences were detected at the qualitative level: Trichoderma populations of endemic plants were highly specific and diverse with hot spots appearing in Madagascar and New Zealand. By contrast, maize plants from all sites shared the majority of Trichoderma species (65.5%). Interestingly, the high above ground biodiversity in ecosystems containing endemic plants was confirmed by a high below ground Trichoderma diversity. Despite the differences, we found a global Trichoderma core community shared by all analysed plants, which was dominated by T. koningii and T. koningiopsis. Amplicon-based network analyses revealed a high similarity between maize Trichoderma grown world-wide and distinct populations of endemic plants. Furthermore, Trichoderma strains from endemic plants showed a higher antagonistic activity against fungal pathogens compared to maize-associated strains. Our results showed that endemic plants are associated with a specific Trichoderma microbiome which possesses a high antagonistic activity indicating that it has potential to be used for biocontrol purposes. PMID:27039271

  15. Characterization of Novel Trichoderma asperellum Isolates to Select Effective Biocontrol Agents Against Tomato Fusarium Wilt

    PubMed Central

    El_Komy, Mahmoud H.; Saleh, Amgad A.; Eranthodi, Anas; Molan, Younes Y.

    2015-01-01

    The use of novel isolates of Trichoderma with efficient antagonistic capacity against Fusarium oxysporum f. sp. lycopersici (FOL) is a promising alternative strategy to pesticides for tomato wilt management. We evaluated the antagonistic activity of 30 isolates of T. asperellum against 4 different isolates of FOL. The production of extracellular cell wall degrading enzymes of the antagonistic isolates was also measured. The random amplified polymorphic DNA (RAPD) method was applied to assess the genetic variability among the T. asperellum isolates. All of the T. asperellum isolates significantly reduced the mycelial growth of FOL isolates but the amount of growth reduction varied significantly as well. There was a correlation between the antagonistic capacity of T. asperellum isolates towards FOL and their lytic enzyme production. Isolates showing high levels of chitinase and β-1,3-glucanase activities strongly inhibited the growth of FOL isolates. RAPD analysis showed a high level of genetic variation among T. asperellum isolates. The UPGMA dendrogram revealed that T. asperellum isolates could not be grouped by their anta- gonistic behavior or lytic enzymes production. Six isolates of T. asperellum were highly antagonistic towards FOL and potentially could be used in commercial agriculture to control tomato wilt. Our results are consistent with the conclusion that understanding the genetic variation within Trichoderma isolates and their biochemical capabilities are required for the selection of effective indigenous fungal strains for the use as biocontrol agents. PMID:25774110

  16. Use of mixed cultures of biocontrol agents to control sheep nematodes.

    PubMed

    Baloyi, M A; Laing, M D; Yobo, K S

    2012-03-23

    Biological control is a promising non-chemical approach for the control of gastrointestinal nematodes of sheep. Use of combinations of biocontrol agents have been reported to be an effective method to increase the efficacy of biological control effects. In this study, combinations of either two Bacillus thuringiensis (Bt) or Clonostachys rosea (C. rosea) isolates and Bt+C. rosea isolates were evaluated in vitro in microtitre plates for their biocontrol activity on sheep nematodes. The Baermann technique was used to extract the surviving L3 larval stages of intestinal nematodes and counted under a dissecting microscope to determine the larval counts. Results indicate that there was a significant reduction of nematode counts due to combination of biocontrol agents (P<0.001). Combinations of Bt isolates reduced nematodes counts by 72.8%, 64% and 29.8%. The results revealed a control level of 57% when C. rosea isolates P3+P8 were combined. Combination of Bt and C. rosea isolates B10+P8 caused the greatest mortality of 76.7%. Most combinations were antagonistic, with only a few combinations showing an additive effect. None were synergistic. The isolate combinations were more effective than when isolates were used alone.

  17. RNA interference of endochitinases in the sugarcane endophyte Trichoderma virens 223 reduces its fitness as a biocontrol agent of pineapple disease.

    PubMed

    Romão-Dumaresq, Aline S; de Araújo, Welington Luiz; Talbot, Nicholas J; Thornton, Christopher R

    2012-01-01

    The sugarcane root endophyte Trichoderma virens 223 holds enormous potential as a sustainable alternative to chemical pesticides in the control of sugarcane diseases. Its efficacy as a biocontrol agent is thought to be associated with its production of chitinase enzymes, including N-acetyl-ß-D-glucosaminidases, chitobiosidases and endochitinases. We used targeted gene deletion and RNA-dependent gene silencing strategies to disrupt N-acetyl-ß-D-glucosaminidase and endochitinase activities of the fungus, and to determine their roles in the biocontrol of soil-borne plant pathogens. The loss of N-acetyl-ß-D-glucosaminidase activities was dispensable for biocontrol of the plurivorous damping-off pathogens Rhizoctonia solani and Sclerotinia sclerotiorum, and of the sugarcane pathogen Ceratocystis paradoxa, the causal agent of pineapple disease. Similarly, suppression of endochitinase activities had no effect on R. solani and S. sclerotiorum disease control, but had a pronounced effect on the ability of T. virens 223 to control pineapple disease. Our work demonstrates a critical requirement for T. virens 223 endochitinase activity in the biocontrol of C. paradoxa sugarcane disease, but not for general antagonism of other soil pathogens. This may reflect its lifestyle as a sugarcane root endophyte.

  18. Biocontrol agents promote growth of potato pathogens, depending on environmental conditions.

    PubMed

    Cray, Jonathan A; Connor, Mairéad C; Stevenson, Andrew; Houghton, Jonathan D R; Rangel, Drauzio E N; Cooke, Louise R; Hallsworth, John E

    2016-05-01

    There is a pressing need to understand and optimize biological control so as to avoid over-reliance on the synthetic chemical pesticides that can damage environmental and human health. This study focused on interactions between a novel biocontrol-strain, Bacillus sp. JC12GB43, and potato-pathogenic Phytophthora and Fusarium species. In assays carried out in vitro and on the potato tuber, the bacterium was capable of near-complete inhibition of pathogens. This Bacillus was sufficiently xerotolerant (water activity limit for growth = 0.928) to out-perform Phytophthora infestans (~0.960) and challenge Fusarium coeruleum (~0.847) and Fusarium sambucinum (~0.860) towards the lower limits of their growth windows. Under some conditions, however, strain JC12GB43 stimulated proliferation of the pathogens: for instance, Fusarium coeruleum growth-rate was increased under chaotropic conditions in vitro (132 mM urea) by >100% and on tubers (2-M glycerol) by up to 570%. Culture-based assays involving macromolecule-stabilizing (kosmotropic) compatible solutes provided proof-of-principle that the Bacillus may provide kosmotropic metabolites to the plant pathogen under conditions that destabilize macromolecular systems of the fungal cell. Whilst unprecedented, this finding is consistent with earlier reports that fungi can utilize metabolites derived from bacterial cells. Unless the antimicrobial activities of candidate biocontrol strains are assayed over a full range of field-relevant parameters, biocontrol agents may promote plant pathogen infections and thereby reduce crop yields. These findings indicate that biocontrol activity, therefore, ought to be regarded as a mode-of-behaviour (dependent on prevailing conditions) rather than an inherent property of a bacterial strain. PMID:26880001

  19. Biocontrol agents promote growth of potato pathogens, depending on environmental conditions.

    PubMed

    Cray, Jonathan A; Connor, Mairéad C; Stevenson, Andrew; Houghton, Jonathan D R; Rangel, Drauzio E N; Cooke, Louise R; Hallsworth, John E

    2016-05-01

    There is a pressing need to understand and optimize biological control so as to avoid over-reliance on the synthetic chemical pesticides that can damage environmental and human health. This study focused on interactions between a novel biocontrol-strain, Bacillus sp. JC12GB43, and potato-pathogenic Phytophthora and Fusarium species. In assays carried out in vitro and on the potato tuber, the bacterium was capable of near-complete inhibition of pathogens. This Bacillus was sufficiently xerotolerant (water activity limit for growth = 0.928) to out-perform Phytophthora infestans (~0.960) and challenge Fusarium coeruleum (~0.847) and Fusarium sambucinum (~0.860) towards the lower limits of their growth windows. Under some conditions, however, strain JC12GB43 stimulated proliferation of the pathogens: for instance, Fusarium coeruleum growth-rate was increased under chaotropic conditions in vitro (132 mM urea) by >100% and on tubers (2-M glycerol) by up to 570%. Culture-based assays involving macromolecule-stabilizing (kosmotropic) compatible solutes provided proof-of-principle that the Bacillus may provide kosmotropic metabolites to the plant pathogen under conditions that destabilize macromolecular systems of the fungal cell. Whilst unprecedented, this finding is consistent with earlier reports that fungi can utilize metabolites derived from bacterial cells. Unless the antimicrobial activities of candidate biocontrol strains are assayed over a full range of field-relevant parameters, biocontrol agents may promote plant pathogen infections and thereby reduce crop yields. These findings indicate that biocontrol activity, therefore, ought to be regarded as a mode-of-behaviour (dependent on prevailing conditions) rather than an inherent property of a bacterial strain.

  20. Phytosanitation and the development of transgenic biocontrol agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    By the year 2050, there will be at least 9 billion people on Earth to feed using the same amount or less land and water than is available today. Currently, about one-third of all potential agricultural commodities grown worldwide are lost to diseases, weeds, insects and other pests. Farmers will be ...

  1. Selection rhizosphere-competent microbes for development of microbial products as biocontrol agents

    NASA Astrophysics Data System (ADS)

    Mashinistova, A. V.; Elchin, A. A.; Gorbunova, N. V.; Muratov, V. S.; Kydralieva, K. A.; Khudaibergenova, B. M.; Shabaev, V. P.; Jorobekova, Sh. J.

    2009-04-01

    Rhizosphere-borne microorganisms reintroduced to the soil-root interface can establish without inducing permanent disturbance in the microbial balance and effectively colonise the rhizosphere due to carbon sources of plant root exudates. A challenge for future development of microbial products for use in agriculture will be selection of rhizosphere-competent microbes that both protect the plant from pathogens and improve crop establishment and persistence. In this study screening, collection, identification and expression of stable and technological microbial strains living in soils and in the rhizosphere of abundant weed - couch-grass Elytrigia repens L. Nevski were conducted. A total of 98 bacteria isolated from the rhizosphere were assessed for biocontrol activity in vitro against phytopathogenic fungi including Fusarium culmorum, Fusarium heterosporum, Fusarium oxysporum, Drechslera teres, Bipolaris sorokiniana, Piricularia oryzae, Botrytis cinerea, Colletothrichum atramentarium and Cladosporium sp., Stagonospora nodorum. Biocontrol activity were performed by the following methods: radial and parallel streaks, "host - pathogen" on the cuts of wheat leaves. A culture collection comprising 64 potential biocontrol agents (BCA) against wheat and barley root diseases has been established. Of these, the most effective were 8 isolates inhibitory to at least 4 out of 5 phytopathogenic fungi tested. The remaining isolates inhibited at least 1 of 5 fungi tested. Growth stimulating activity of proposed rhizobacteria-based preparations was estimated using seedling and vegetative pot techniques. Seeds-inoculation and the tests in laboratory and field conditions were conducted for different agricultural crops - wheat and barley. Intact cells, liquid culture filtrates and crude extracts of the four beneficial bacterial strains isolated from the rhizosphere of weed were studied to stimulate plant growth. As a result, four bacterial strains selected from rhizosphere of weed

  2. Detection and quantification by PCR assay of the biocontrol agent Pantoea agglomerans CPA-2 on apples.

    PubMed

    Soto-Muñoz, Lourdes; Teixidó, Neus; Usall, Josep; Viñas, Inmaculada; Torres, Rosario

    2014-04-01

    The registration of biological control agents requires the development of monitoring systems to detect and quantify the agent in the environment. Pantoea agglomerans CPA-2 is an effective biocontrol agent for postharvest diseases of citrus and pome fruits. The monitoring of CPA-2 in postharvest semi-commercial trials was evaluated by Rodac impression plates and the colonies isolated were confirmed by conventional PCR using the SCAR primers PAGA1 and PAGB1. Samples were taken from different surfaces that had contact with CPA-2, the surrounding environment and working clothes worn by handlers. Moreover, population dynamics of the strain CPA-2 were determined on apple surfaces using both the classical plating technique and real-time quantitative PCR (qPCR). A qPCR assay using a 3'-minor groove-binding (MGB) probe was developed for the specific detection and quantification of P. agglomerans strain CPA-2. Based on the nucleotide sequence of a SCAR fragment of CPA-2, one primer set and TaqMan MGB probe were designed. The primers SP2-F/SP2-R and the TaqMan MGB probe showed a specific detection of strain CPA-2 on apple surfaces, which was verified tested against purified DNA from 17 strains of P. agglomerans, 4 related Pantoea species, and 21 bacterial strains from other genera isolated from whole and also freshly-cut fruit and vegetables. The detection level was approximately 10(3) cells per reaction, and the standard curve was linear within a range of 5log units. Results from semi-commercial trials showed that CPA-2 had a low impact. The maximum persistence of P. agglomerans CPA-2 was not longer than 5days in plastic boxes stored at 0°C. Significant differences in CPA-2 population level dynamics were observed in results obtained by qPCR and dilution plating. These differences may indicate the presence of non-degraded DNA from non-viable cells. In conclusion, qPCR is a novel potential tool to quickly and specifically monitor recent surface colonisation by CPA-2

  3. Detection and quantification by PCR assay of the biocontrol agent Pantoea agglomerans CPA-2 on apples.

    PubMed

    Soto-Muñoz, Lourdes; Teixidó, Neus; Usall, Josep; Viñas, Inmaculada; Torres, Rosario

    2014-04-01

    The registration of biological control agents requires the development of monitoring systems to detect and quantify the agent in the environment. Pantoea agglomerans CPA-2 is an effective biocontrol agent for postharvest diseases of citrus and pome fruits. The monitoring of CPA-2 in postharvest semi-commercial trials was evaluated by Rodac impression plates and the colonies isolated were confirmed by conventional PCR using the SCAR primers PAGA1 and PAGB1. Samples were taken from different surfaces that had contact with CPA-2, the surrounding environment and working clothes worn by handlers. Moreover, population dynamics of the strain CPA-2 were determined on apple surfaces using both the classical plating technique and real-time quantitative PCR (qPCR). A qPCR assay using a 3'-minor groove-binding (MGB) probe was developed for the specific detection and quantification of P. agglomerans strain CPA-2. Based on the nucleotide sequence of a SCAR fragment of CPA-2, one primer set and TaqMan MGB probe were designed. The primers SP2-F/SP2-R and the TaqMan MGB probe showed a specific detection of strain CPA-2 on apple surfaces, which was verified tested against purified DNA from 17 strains of P. agglomerans, 4 related Pantoea species, and 21 bacterial strains from other genera isolated from whole and also freshly-cut fruit and vegetables. The detection level was approximately 10(3) cells per reaction, and the standard curve was linear within a range of 5log units. Results from semi-commercial trials showed that CPA-2 had a low impact. The maximum persistence of P. agglomerans CPA-2 was not longer than 5days in plastic boxes stored at 0°C. Significant differences in CPA-2 population level dynamics were observed in results obtained by qPCR and dilution plating. These differences may indicate the presence of non-degraded DNA from non-viable cells. In conclusion, qPCR is a novel potential tool to quickly and specifically monitor recent surface colonisation by CPA-2

  4. Phaeobacter inhibens as biocontrol agent against Vibrio vulnificus in oyster models.

    PubMed

    Porsby, Cisse Hedegaard; Gram, Lone

    2016-08-01

    Molluscan shellfish can cause food borne diseases and here we investigated if addition of Vibrio-antagonising bacteria could reduce Vibrio vulnificus in model oyster systems and prevent its establishment in live animals. Phaeobacter inhibens, which produces an antibacterial compound, tropodithietic acid (TDA), inhibited V. vulnificus as did pure TDA (MIC of 1-3.9 μM). P. inhibens DSM 17395 (at 10(6) cfu/ml) eradicated 10(5) cfu/ml V. vulnificus CMCP6 (a rifampicin resistant variant) from a co-culture oyster model system (oyster juice) whereas the pathogen grew to 10(7) cfu/ml when co-cultured with a TDA negative Phaeobacter mutant. P. inhibens grew well in oyster juice to 10(8) CFU/ml and sterile filtered samples from these cultures were inhibitory to Vibrio spp. P. inhibens established itself in live European flat oysters (Ostrea edulis) and remained at 10(5) cfu/g for five days. However, the presence of P. inhibens could not prevent subsequently added V. vulnificus from entering the live animals, likely because of too low levels of the biocontrol strain. Whilst the oyster model studies provided indication that P. inhibens DSM 17395 could be a good candidate as biocontrol agent against V. vulnificus further optimization is need in the actual animal rearing situation. PMID:27052703

  5. Catabolic pathway of gamma-caprolactone in the biocontrol agent Rhodococcus erythropolis.

    PubMed

    Barbey, Corinne; Crépin, Alexandre; Cirou, Amélie; Budin-Verneuil, Aurélie; Orange, Nicole; Feuilloley, Marc; Faure, Denis; Dessaux, Yves; Burini, Jean-François; Latour, Xavier

    2012-01-01

    Gamma-caprolactone (GCL) is well-known as a food flavor and has been recently described as a biostimulant molecule promoting the growth of bacteria with biocontrol activity against soft-rot pathogens. Among these biocontrol agents, Rhodococcus erythropolis, characterized by a remarkable metabolic versatility, assimilates various γ-butyrolactone molecules with a branched-aliphatic chain, such as GCL. The assimilative pathway of GCL in R. erythropolis was investigated by two-dimensional gel electrophoresis coupled to matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) analysis. This analysis suggests the involvement of the lactonase QsdA in ring-opening, a feature confirmed by heterologous expression in Escherichia coli. According to proteome analysis, the open-chain form of GCL was degraded by β- and ω-oxidation coupled to the Krebs cycle and β-ketoadipate pathway. Ubiquity of qsdA gene among environmental R. erythropolis isolates was verified by PCR. In addition to a previous N-acyl homoserine lactone catabolic function, QsdA may therefore be involved in an intermediate degradative step of cyclic recalcitrant molecules or in synthesis of flavoring lactones. PMID:22085026

  6. Biocontrol: The Potential of Entomophilic Nematodes in Insect Management

    PubMed Central

    Webster, John M.

    1980-01-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management. PMID:19300702

  7. Global changes in expression of grapefruit peel tissue in response to the yeast biocontrol agent, Metschnikowia fructicola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To gain a better understanding of the molecular changes taking place in citrus fruit tissue following the application of the yeast biocontrol agent, Metschnikowia fructicola, microarray analysis was performed on grapefruit surface wounds using an Affymetrix Citrus GeneChip. Using a cut off of p<0.0...

  8. Hrp mutant bacteria as biocontrol agents: toward a sustainable approach in the fight against plant pathogenic bacteria.

    PubMed

    Hanemian, Mathieu; Zhou, Binbin; Deslandes, Laurent; Marco, Yves; Trémousaygue, Dominique

    2013-10-01

    Sustainable agriculture necessitates development of environmentally safe methods to protect plants against pathogens. Among these methods, application of biocontrol agents has been efficiently used to minimize disease development. Here we review current understanding of mechanisms involved in biocontrol of the main Gram-phytopathogenic bacteria-induced diseases by plant inoculation with strains mutated in hrp (hypersensitive response and pathogenicity) genes. These mutants are able to penetrate plant tissues and to stimulate basal resistance of plants. Novel protection mechanisms involving the phytohormone abscisic acid appear to play key roles in the biocontrol of wilt disease induced by Ralstonia solanacearum in Arabidopsis thaliana. Fully understanding these mechanisms and extending the studies to other pathosystems are still required to evaluate their importance in disease protection.

  9. Production of a newly isolated Paenibacillus polymyxa biocontrol agent using monosodium glutamate wastewater and potato wastewater.

    PubMed

    Gu, Likun; Bai, Zhihui; Jin, Bo; Zhang, Jianyun; Li, Wenying; Zhuang, Guoqiang; Zhang, Hongxun

    2010-01-01

    A phyllosphere bacterial strain EBL-06 was isolated from wheat leaves. The morphology, cultural characteristics, phospholipid fatty acids, physiological and antagonistic fungus activities of this strain were investigated. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the relevant bacteria. The results showed that the isolate EBL-06 was a strain of Paenibacillus polymyxa; this strain performed a high level of antagonistic fungus activity toward a broad spectrum of phytopathogens, such as Botrytis cinerea, Cladosporium cucumerinum, Fusarium spp. The isolate EBL-06 can grow well using monosodium glutamate wastewater (MGW) and potato wastewater (PW) as culture medium. The maximum yield of 6.5 x 10(9) CFU/mL of the isolate EBL-06 anti-fungus biocontrol agent was reached in 15 hr cultivation at 28 degrees C, pH 6.0-7.5 using the mixture of MGW and PW (1:9).

  10. Biological and molecular characterisation of potential biocontrol strains of Trichoderma.

    PubMed

    Turóczi, G; Fekete, C; Kerényi, Z; Nagy, R; Pomázi, A; Hornok, L

    1996-01-01

    Thirty-four strains of seven species of Trichoderma isolated from various fungal sources were compared for direct mycoparasitic activity (MPA), chitinase production and antibiotic activity (ANA) in order to choose the most appropriate partners for a strain-breeding programme. Within species genetic differences were also assesses in T. hamatum, T. harzianum and T. viride by means of random amplification of polymorphic DNA (RAPD). Endochitinase activities of the Trichoderma strains ranged between 20.4 and 1264.5 units/g dry weight of mycelium. The correlation between MPA and chitinase activity was not unambiguous and no correlation existed between MPA and ANA. The RAPD patterns of T. viride strains were highly variable, while isolates of T. harzianum proved to be more uniform; T. hamatum revealed remarkable intraspecific divergence. All these three comprised certain pairs of strains that are promising participants of a strain-improving programme, since their strong genetic affinities offer good changes for combining their contrasted biocontrol traits.

  11. Ecophysiological requirements and survival of a Trichoderma atroviride isolate with biocontrol potential.

    PubMed

    Longa, Claudia Maria Oliveira; Pertot, Ilaria; Tosi, Solveig

    2008-08-01

    Trichoderma atroviride SC1, isolated from decayed hazelnut wood in northern Italy in 2000, is a promising fungal agent for biological control of soil-borne plant pathogens. The objective of this research was to characterize the biology and ecology of this fungus, in order to determine its environmental parameter tolerance levels and its behavior in the phylloplane and soil systems. To better characterize T. atroviride SC1, the influences of pH, temperature, water activity and different nitrogen and carbon sources on its in vitro growth were evaluated. T. atroviride SC1 survival was assessed on strawberry leaves under controlled conditions in a greenhouse and in sterilized and non-sterilized soil samples kept at room temperature. Results showed that isolate SC1 is mesophilic and grows best at 25 degrees C. The fungus tolerates a wide range of pH levels, but growth was reduced on alkaline media (pH >or= 8). The nitrogen and carbon sources peptone, tryptone, nitrate, mannose, galactose and sucrose were associated with the highest mycelial biomass production, as compared with other potential sources of nitrogen and carbon. The fungus survived on strawberry leaves under greenhouse conditions (25 +/- 2 degrees C, RH = 60 +/- 10%) and grew in sterilized soils at room temperature (23 +/- 2 degrees C) for 45 d. However, no increase in mycelial dry weight was observed in non-sterilized soils. T. atroviride SC1 survived under the test conditions, showing a good potential for use in soil and foliar biocontrol applications.

  12. Rhizospheric bacteria of maize with potential for biocontrol of Fusarium verticillioides.

    PubMed

    Figueroa-López, Alejandro Miguel; Cordero-Ramírez, Jesús Damián; Martínez-Álvarez, Juan Carlos; López-Meyer, Melina; Lizárraga-Sánchez, Glenda Judith; Félix-Gastélum, Rubén; Castro-Martínez, Claudia; Maldonado-Mendoza, Ignacio Eduardo

    2016-01-01

    The stalk, ear and root rot (SERR) of maize caused by Fusarium verticillioides (Fv) severely impacts crop production in tropical and subtropical regions. The aim of the present work was to screen bacterial isolates in order to find novel native biocontrol agents against Fv. A culturable bacterial collection consisting of 11,520 isolates enriched in Firmicutes and Proteobacteria was created from rhizosphere samples taken from SERR symptomatic or asymptomatic maize plants. The complete collection was screened for potential activity against Fv using a liquid antagonism assay followed by dual cultures in solid medium, selecting for 42 bacteria (Bacillus, Pseudomonas and Paenibacillus) that inhibit Fv growth (>45 %). In planta assays demonstrated that three Bacillus isolates: B. megaterium (B5), B. cereus sensu lato (B25) and Bacillus sp. (B35) displayed the highest antagonistic activity against Fv. Pot experiments performed in a greenhouse with Bacillus cereus sensu lato B25 confirmed these findings and showed a reduction of Fv disease severity and incidence on plants. Antagonistic activity analysis revealed that these strains produce glucanases, proteases or chitinases, as well as siderophores and auxins and suggests these as possible control mechanisms against Fv.

  13. Tailoring biocontrol to maximize top-down effects: on the importance of underlying site fertility.

    PubMed

    Hovick, Stephen M; Carson, Walter P

    2015-01-01

    The degree to which biocontrol agents impact invasive plants varies widely across landscapes, often for unknown reasons. Understanding this variability can help optimize invasive species management while also informing our understanding of trophic linkages. To address these issues, we tested three hypotheses with contrasting predictions regarding the likelihood of biocontrol success. (1) The biocontrol effort hypothesis: invasive populations are regulated primarily by top-down effects, predicting that increased biocontrol efforts alone (e.g., more individuals of a given biocontrol agent or more time since agent release) will enhance biocontrol success. (2) The relative fertility hypothesis: invasive populations are regulated primarily by bottom-up effects, predicting that nutrient enrichment will increase dominance by invasives and thus reduce biocontrol success, regardless of biocontrol efforts. (3) The fertility-dependent biocontrol effort hypothesis: top-down effects will only regulate invasive populations if bottom-up effects are weak. It predicts that greater biocontrol efforts will increase biocontrol success, but only in low-nutrient sites. To test these hypotheses, we surveyed 46 sites across three states with prior releases of Galerucella beetles, the most common biocontrol agents used against invasive purple loosestrife (Lythrum salicaria). We found strong support for the fertility-dependent biocontrol effort hypothesis, as biocontrol success occurred most often with greater biocontrol efforts, but only in low-fertility sites. This result held for early stage metrics of biocontrol success (higher Galerucella abundance) and ultimate biocontrol outcomes (decreased loosestrife plant size and abundance). Presence of the invasive grass Phalaris arundinacea was also inversely related to loosestrife abundance, suggesting that biocontrol-based reductions in loosestrife made secondary invasion by P. arundinacea more likely. Our data suggest that low-nutrient sites

  14. Biocontrol potential of endophytes harbored in Radula marginata (liverwort) from the New Zealand ecosystem.

    PubMed

    Kusari, Parijat; Kusari, Souvik; Spiteller, Michael; Kayser, Oliver

    2014-10-01

    Radula marginata and Cannabis sativa L. are two phylogenetically unrelated plant species containing structurally similar secondary metabolites like cannabinoids. The major objective of our work was the isolation, identification, biocontrol efficacies, biofilm forming potential and anti-biofilm ability of endophytic microbial community of the liverwort R. marginata, as compared to bacterial endophytic isolates harbored in C. sativa plants. A total of 15 endophytic fungal and 4 endophytic bacterial isolates were identified, including the presence of a bacterial endosymbiont within an endophytic fungal isolate. The endosymbiont was visible only when the fungus containing it was challenged with two phytopathogens Botrytis cinerea and Trichothecium roseum, highlighting a tripartite microbe-microbe interaction and biocontrol potency of endophytes under biotic stress. We also observed sixteen types of endophytic fungal-pathogen and twelve types of endophytic bacterial-pathogen interactions coupled to varying degree of growth inhibitions of either the pathogen or endophyte or both. This showed the magnitude of biocontrol efficacies of endophytes in aiding plant fitness benefits under different media (environmental) conditions. Additionally, it was ecologically noteworthy to find the presence of similar endophytic bacterial genera in both Radula and Cannabis plants, which exhibited similar functional traits like biofilm formation and general anti-biofilm activities. Thus far, our work underlines the biocontrol potency and defensive functional traits (in terms of antagonism and biofilm formation) of endophytes harbored in liverwort R. marginata as compared to the endophytic community of phylogenetically unrelated but phytochemically similar plant C. sativa. PMID:25100187

  15. Antagonistic and Biocontrol Potential of Trichoderma asperellum ZJSX5003 Against the Maize Stalk Rot Pathogen Fusarium graminearum.

    PubMed

    Li, Yaqian; Sun, Ruiyan; Yu, Jia; Saravanakumar, Kandasamy; Chen, Jie

    2016-09-01

    The efficacy of seven strains of Trichoderma asperellum collected from the fields in Southern China was assessed against Fusarium graminearum (FG) the causal agent of corn stalk rot of maize were in vitro for their antagonistic properties followed by statistical model of principal compound analysis to identify the beneficial antagonist T. asperellum strain. The key factors of antagonist activity were attributed to a total of 13 factors including cell wall degrading enzymes (chitnase, protease and β-glucanases), secondary metabolites and peptaibols and these were analyzed from eight strains of Trichoderma. A linear regression model demonstrated that interaction of enzymes and secondary metabolites of T. asperellum strain ZJSX5003 enhanced the antagonist activity against FG. Further, this strain displayed a disease reduction of 71 % in maize plants inoculated with FG compared to negative control. Pointing out that the T. asperellum strain ZJSX5003 is a potential source for the development of a biocontrol agent against corn stalk rot. PMID:27407296

  16. Antagonistic and Biocontrol Potential of Trichoderma asperellum ZJSX5003 Against the Maize Stalk Rot Pathogen Fusarium graminearum.

    PubMed

    Li, Yaqian; Sun, Ruiyan; Yu, Jia; Saravanakumar, Kandasamy; Chen, Jie

    2016-09-01

    The efficacy of seven strains of Trichoderma asperellum collected from the fields in Southern China was assessed against Fusarium graminearum (FG) the causal agent of corn stalk rot of maize were in vitro for their antagonistic properties followed by statistical model of principal compound analysis to identify the beneficial antagonist T. asperellum strain. The key factors of antagonist activity were attributed to a total of 13 factors including cell wall degrading enzymes (chitnase, protease and β-glucanases), secondary metabolites and peptaibols and these were analyzed from eight strains of Trichoderma. A linear regression model demonstrated that interaction of enzymes and secondary metabolites of T. asperellum strain ZJSX5003 enhanced the antagonist activity against FG. Further, this strain displayed a disease reduction of 71 % in maize plants inoculated with FG compared to negative control. Pointing out that the T. asperellum strain ZJSX5003 is a potential source for the development of a biocontrol agent against corn stalk rot.

  17. Bacteriocin-Producing Lactic Acid Bacteria Isolated from Mangrove Forests in Southern Thailand as Potential Bio-Control Agents: Purification and Characterization of Bacteriocin Produced by Lactococcus lactis subsp. lactis KT2W2L.

    PubMed

    Hwanhlem, Noraphat; Biscola, Vanessa; El-Ghaish, Shady; Jaffrès, Emmanuel; Dousset, Xavier; Haertlé, Thomas; H-Kittikun, Aran; Chobert, Jean-Marc

    2013-12-01

    The aim of this work was to purify and characterize the bacteriocin produced by Lactococcus lactis subsp. lactis KT2W2L previously isolated from mangrove forests in southern Thailand, in order to evaluate its potential as new food protective agent. The active peptide from the cell-free supernatant of this strain was purified in 4 steps: (1) precipitation with 70 % saturated ammonium sulfate, (2) elution on a reversed-phase cartridge using different concentrations of acetonitrile, (3) cation-exchange chromatography and (4) final purification by reversed-phase HPLC on a C8 column. The molecular mass of 3,329.5254 Da of the purified bacteriocin, determined by mass spectrometry, is nearly identical to that of peptide nisin Z. The activity of the purified bacteriocin was unaffected by pH (2.0-10.0), thermostable but was sensitive to proteolytic enzymes. The bacteriocin activity was stable after 8 weeks of storage at -20 °C and 7 weeks of storage at 4 °C, but decreased after 3 weeks of storage at 37 °C. It was stable when incubated for 1 month at 4 °C in 0-30 % NaCl. Inhibitory spectrum of this bacteriocin showed a wide range of activity against similar bacterial strains, food-spoilage and food-borne pathogens. L. lactis subsp. lactis KT2W2L was sensitive to kanamycin, penicillin and tetracycline but resistant to ampicillin, gentamicin and vancomycin. The fragment obtained after amplification of genomic DNA from L. lactis subsp. lactis KT2W2L, with specific primers for bacteriocin genes, presented 99 % homology to the nisin Z gene. PCR amplification demonstrated that L. lactis subsp. lactis KT2W2L does not harbor virulence genes cylA, cylB, efaAfs and esp. The bacteriocin and its producing strain may find application as bio-preservatives for reduction in food-spoilage and food-borne pathogens in food products.

  18. Ecology of Anti-Biofilm Agents II: Bacteriophage Exploitation and Biocontrol of Biofilm Bacteria

    PubMed Central

    Abedon, Stephen T.

    2015-01-01

    Bacteriophages are the viruses of bacteria. In the guise of phage therapy they have been used for decades to successfully treat what are probable biofilm-containing chronic bacterial infections. More recently, phage treatment or biocontrol of biofilm bacteria has been brought back to the laboratory for more rigorous assessment as well as towards the use of phages to combat environmental biofilms, ones other than those directly associated with bacterial infections. Considered in a companion article is the inherent ecological utility of bacteriophages versus antibiotics as anti-biofilm agents. Discussed here is a model for phage ecological interaction with bacteria as they may occur across biofilm-containing ecosystems. Specifically, to the extent that individual bacterial types are not highly abundant within biofilm-containing environments, then phage exploitation of those bacteria may represent a “Feast-or-famine” existence in which infection of highly localized concentrations of phage-sensitive bacteria alternate with treacherous searches by the resulting phage progeny virions for new concentrations of phage-sensitive bacteria to infect. An updated synopsis of the literature concerning laboratory testing of phage use to combat bacterial biofilms is then provided along with tips on how “Ecologically” such phage-mediated biofilm control can be modified to more reliably achieve anti-biofilm efficacy. PMID:26371011

  19. Native Killer Yeasts as Biocontrol Agents of Postharvest Fungal Diseases in Lemons

    PubMed Central

    Garnica, Nydia Mercedes; Fernández-Zenoff, María Verónica; Farías, María Eugenia; Sepulveda, Milena; Ramallo, Jacqueline; Dib, Julián Rafael

    2016-01-01

    Economic losses caused by postharvest diseases represent one of the main problems of the citrus industry worldwide. The major diseases affecting citrus are the "green mold" and "blue mold", caused by Penicillium digitatum and P. italicum, respectively. To control them, synthetic fungicides are the most commonly used method. However, often the emergence of resistant strains occurs and their use is becoming more restricted because of toxic effects and environmental pollution they generate, combined with trade barriers to international markets. The aim of this work was to isolate indigenous killer yeasts with antagonistic activity against fungal postharvest diseases in lemons, and to determine their control efficiency in in vitro and in vivo assays. Among 437 yeast isolates, 8.5% show to have a killer phenotype. According to molecular identification, based on the 26S rDNA D1/D2 domain sequences analysis, strains were identified belonging to the genera Saccharomyces, Wickerhamomyces, Kazachstania, Pichia, Candida and Clavispora. Killers were challenged with pathogenic molds and strains that caused the maximum in vitro inhibition of P. digitatum were selected for in vivo assays. Two strains of Pichia and one strain of Wickerhamomyces depicted a significant protection (p <0.05) from decay by P. digitatum in assays using wounded lemons. Thus, the native killer yeasts studied in this work showed to be an effective alternative for the biocontrol of postharvest fungal infections of lemons and could be promising agents for the development of commercial products for the biological control industry. PMID:27792761

  20. Biocontrol agent Bacillus amyloliquefaciens LJ02 induces systemic resistance against cucurbits powdery mildew

    PubMed Central

    Li, Yunlong; Gu, Yilin; Li, Juan; Xu, Mingzhu; Wei, Qing; Wang, Yuanhong

    2015-01-01

    Powdery mildew is a fungal disease found in a wide range of plants and can significantly reduce crop yields. Bacterial strain LJ02 is a biocontrol agent (BCA) isolated from a greenhouse in Tianjin, China. In combination of morphological, physiological, biochemical and phylogenetic analyses, strain LJ02 was classified as a new member of Bacillus amyloliquefaciens. Greenhouse trials showed that LJ02 fermentation broth (LJ02FB) can effectively diminish the occurrence of cucurbits powdery mildew. When treated with LJ02FB, cucumber seedlings produced significantly elevated production of superoxide dismutase, peroxidase, polyphenol oxidase and phenylalanine ammonia lyase as compared to that of the control. We further confirmed that the production of free salicylic acid (SA) and expression of one pathogenesis-related (PR) gene PR-1 in cucumber leaves were markedly elevated after treating with LJ02FB, suggesting that SA-mediated defense response was stimulated. Moreover, LJ02FB-treated cucumber leaves could secrete resistance-related substances into rhizosphere that inhibit the germination of fungi spores and the growth of pathogens. Finally, we separated bacterium and its fermented substances to test their respective effects and found that both components have SA-inducing activity and bacterium plays major roles. Altogether, we identified a BCA against powdery mildew and its mode of action by inducing systemic resistance such as SA signaling pathway. PMID:26379654

  1. [Impact of biocontrol agent Bacillus subtilis on bacterial communities in tobacco rhizospheric soil].

    PubMed

    You, Cai; Zhang, Li-Meng; Ji, Si-Gui; Gao, Jia-Ming; Zhang, Cheng-Sheng; Kong, Fan-Yu

    2014-11-01

    The impact of inoculation with the biocontrol agent Bacillus subtilis on bacterial communities and bacterial diversity in rhizospheric soil of Nicotiana tabacum was assessed by constructing a 16S rRNA gene clone library and conducting amplified ribosomal DNA restriction analysis (ARDRA). The bacterial diversity was evaluated by coverage value (C), Shannon index (H), Pielou evenness index (E) and Margalef richness index (R). Phylogenetic analysis revealed that the inoculation significantly affected the composition of bacterial communities in tobacco rhizospheric soil. A total of twelve bacterial groups including Acidobacteria, Proteobacteria (including α-, β-, δ-, γ-Proteobacteria) , Planctomycetes, Firmicutes, Nitrospirae, Gemmatimonadetes, Actinobacteria, Chloroflexi and Bacteroidetes were detected to be shared by inoculated soil and control soil. The community composition and proportions of different bacteria in the communities showed significant variations between the two samples. The dominant bacteria were Acidobacteria (27.1%) and Proteobacteria (26.5%) in control soil, while in the inoculated soil Proteobacteria (38.0%) and Acidobacteria (29.6%) were dominant. B. subtilis inoculation increased the numbers of γ-Proteobacteria and α-Proteobacteria but reduced the numbers of bacterial groups such as β-Proteobacteria, Planctomycetes, Firmicutes. Diversity analysis showed that bacterial diversity was rich for both soil samples, and soil bacterial Shannon index and Margalef richness index were promoted after inoculation.

  2. Improvement of the fungal biocontrol agent Trichoderma atroviride to enhance both antagonism and induction of plant systemic disease resistance.

    PubMed

    Brunner, Kurt; Zeilinger, Susanne; Ciliento, Rosalia; Woo, Sheridian L; Lorito, Matteo; Kubicek, Christian P; Mach, Robert L

    2005-07-01

    Biocontrol agents generally do not perform well enough under field conditions to compete with chemical fungicides. We determined whether transgenic strain SJ3-4 of Trichoderma atroviride, which expresses the Aspergillus niger glucose oxidase-encoding gene, goxA, under a homologous chitinase (nag1) promoter had increased capabilities as a fungal biocontrol agent. The transgenic strain differed only slightly from the wild-type in sporulation or the growth rate. goxA expression occurred immediately after contact with the plant pathogen, and the glucose oxidase formed was secreted. SJ3-4 had significantly less N-acetylglucosaminidase and endochitinase activities than its nontransformed parent. Glucose oxidase-containing culture filtrates exhibited threefold-greater inhibition of germination of spores of Botrytis cinerea. The transgenic strain also more quickly overgrew and lysed the plant pathogens Rhizoctonia solani and Pythium ultimum. In planta, SJ3-4 had no detectable improved effect against low inoculum levels of these pathogens. Beans planted in heavily infested soil and treated with conidia of the transgenic Trichoderma strain germinated, but beans treated with wild-type spores did not germinate. SJ3-4 also was more effective in inducing systemic resistance in plants. Beans with SJ3-4 root protection were highly resistant to leaf lesions caused by the foliar pathogen B. cinerea. This work demonstrates that heterologous genes driven by pathogen-inducible promoters can increase the biocontrol and systemic resistance-inducing properties of fungal biocontrol agents, such as Trichoderma spp., and that these microbes can be used as vectors to provide plants with useful molecules (e.g., glucose oxidase) that can increase their resistance to pathogens.

  3. Biology and host preferences of Cryptorhynchus melastomae (Coleoptera: Curculionidae), a possible biocontrol agent for Miconia calvescens (Melastomataceae) in Hawaii.

    PubMed

    Reichert, Elisabeth; Johnson, M Tracy; Chacón, Eduardo; Anderson, Robert S; Wheeler, Terry A

    2010-12-01

    The introduced plant Miconia calvescens (Melastomataceae) poses a grave threat to Hawaii's native ecosystems and biodiversity. One potential candidate for classical biological control is Cryptorhynchus melastomae (Coleoptera: Curculionidae: Cryptorhynchinae), a stem-boring weevil from Central and South America. This weevil feeds on M. calvescens in its native Costa Rica and has been successfully reared under greenhouse conditions. Comparison of its environmental conditions in Costa Rica with those in the Miconia infested areas of Hawaii indicates the latter is a suitable habitat for C. melastomae. C. melastomae has one or two generations per year. Adults feed on new stems, petioles, leaf buds, veins, and lamina, whereas larvae mine the stem until pupation. Adults appear to prefer saplings for oviposition and feeding. Under greenhouse conditions both adults and larvae can seriously damage and kill small M. calvescens. Preliminary host testing indicates that C. melastomae may be family specific on Melastomataceae. However, because Hawaii lacks native melastomes and has many other serious melastome weeds, a family specific insect may be suitable as a biocontrol agent in this case. PMID:22182550

  4. Integrated management of foot rot of lentil using biocontrol agents under field condition.

    PubMed

    Hannan, M A; Hasan, M M; Hossain, I; Rahman, S M E; Ismail, Alhazmi Mohammed; Oh, Deog-Hwan

    2012-07-01

    The efficacy of cowdung, Bangladesh Institute of Nuclear Agriculture (BINA)-biofertilizer, and Bangladesh Agricultural University (BAU)-biofungicide, alone or in combination, was evaluated for controlling foot rot disease of lentil. The results exhibited that BINA-biofertilizer and BAUbiofungicide (peat soil-based Rhizobium leguminosarum and black gram bran-based Trichoderma harzianum) are compatible and have combined effects in controlling the pathogenic fungi Fusarium oxysporum and Sclerotium rolfsii, which cause the root rot of lentil. Cowdung mixing with soil (at 5 t/ha) during final land preparation and seed coating with BINA-biofertilizer and BAU-biofungicide (at 2.5% of seed weight) before sowing recorded 81.50% field emergence of lentil, which showed up to 19.85% higher field emergence over the control. Post-emergence deaths of plants due to foot rot disease were significantly reduced after combined seed treatment with BINA-biofertilizer and BAU-biofungicide. Among the treatments used, only BAU-biofungicide as the seed treating agent resulted in higher plant stand (84.82%). Use of BINA-biofertilizer and BAU-biofungicide as seed treating biocontrol agents and application of cowdung in the soil as an organic source of nutrient resulted in higher shoot and root lengths, and dry shoot and root weights of lentil. BINA-biofertilizer significantly increased the number of nodules per plant and nodules weight of lentil. Seeds treating with BAUbiofungicide and BINA-biofertilizer and soil amendment with cowdung increased the biomass production of lentil up to 75.56% over the control.

  5. Biocontrol: Bacillus penetrans and Related Parasites of Nematodes

    PubMed Central

    Sayre, R. M.

    1980-01-01

    Bacillus penetrans Mankau, 1975, previously described as Duboscqia penetrans Thorne 1940, is a candidate agent for biocontrol of nematodes. This review considers the life stages of this bacterium: vegetative growth phase, colony fragmentation, sporogenesis, soil phase, spore attachment, and penetration into larvae of root-knot nematodes. The morphology of the microthallus colonies and the unusual external features of the spore are discussed. Taxonomic affinities with the actinomycetes, particularly with the genus Pasteuria, are considered. Also discussed are other soil bacterial species that are potential biocontrol agents. Products of their bacterial fermentation in soil are toxic to nematodes, making them effective biocontrol agents. PMID:19300701

  6. Amblyseius swirskii: what made this predatory mite such a successful biocontrol agent?

    PubMed

    Calvo, F Javier; Knapp, Markus; van Houten, Yvonne M; Hoogerbrugge, Hans; Belda, José E

    2015-04-01

    The predatory mite Amblyseius swirskii quickly became one of the most successful biocontrol agents in protected cultivation after its introduction into the market in 2005 and is now released in more than 50 countries. There are several key factors contributing to this success: (1) it can control several major pests including the western flower thrips, Frankliniella occidentalis, the whiteflies Bemisia tabaci and Trialeurodes vaporariorum and the broad mite, Polyphagotarsonemus latus, simultaneously in vegetables and ornamental crops; (2) it can develop and reproduce feeding on non-prey food sources such as pollen, which allows populations of the predator to build up on plants before the pests are present and to persist in the crop during periods when prey is scarce or absent; and (3) it can be easily reared on factitious prey, which allows economic mass production. However, despite the fact that A. swirskii provides growers with a robust control method, external demands were initially a key factor in promoting the use of this predator, particularly in Spain. In 2006, when exports of fresh vegetables from Spain were stopped due to the presence of pesticide residues, growers were forced to look for alternatives to chemical control. This resulted in the massive adoption of biological control-based integrated pest management programmes based on the use of A. swirskii in sweet pepper. Biological control increased from 5 % in 2005, 1 year before A. swirskii was commercially released, to almost 100 % of a total 6,000 ha of protected sweet pepper in Spain within 3 years. Later, it was demonstrated that A. swirskii was equally effective in other crops and countries, resulting in extensive worldwide use of A. swirskii in greenhouses.

  7. Chitinases from the Plant Disease Biocontrol Agent, Stenotrophomonas maltophilia C3.

    PubMed

    Zhang, Z; Yuen, G Y; Sarath, G; Penheiter, A R

    2001-02-01

    ABSTRACT Stenotrophomonas maltophilia strain C3, a biocontrol agent of Bipolaris sorokiniana in turfgrass, produced chitinases in broth media containing chitin. Chitinases were partially purified from culture fluid by ammonium sulfate precipitation and chitin affinity chromatography. The chromatography fraction with the highest specific chitinase activity was inhibitory to conidial germination and germ-tube elongation of B. sorokiniana, but it was less inhibitory than the protein fraction or the raw culture filtrate. The fraction exhibited strong exochitinase and weak endo-chitinase activity. Optimum temperature and pH for chitinase activity were 45 to 50 degrees C and 4.5 to 5.0, respectively. Chitinase activity was inhibited by Hg(2+) and Fe(3+), but not by other metal ions or enzyme inhibitors. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the chromatography fraction revealed the presence of five protein bands of 25, 32, 48, 65, and 75 kDa. Partial amino acid sequences of the 32-, 65-, and 75-kDa proteins indicated that they are homologous to known bacterial chitinases. There was no homology found in the partial amino acid sequences of the 25- and 48-kDa proteins to any known chitinases. Five chitinase-active proteins were detected in the protein and chromatography fractions by activity gels, but when each protein was extracted and re-electrophoresed separately under denaturing conditions, only 32- or 48-kDa proteins were revealed. It was concluded that strain C3 produces at least two chitinases that are antifungal.

  8. GFP technology for the study of biocontrol agents in tritrophic interactions: a case study with Pseudozyma flocculosa.

    PubMed

    Neveu, Bertrand; Labbé, Caroline; Bélanger, Richard R

    2007-02-01

    GFP technology was applied to the biocontrol agent (BCA) Pseudozyma flocculosa to study its development and interactions at the tritrophic level plant-powdery mildew-BCA. Transformation experiments with GFP led to the production of a strongly fluorescent strain, Act-4, that displayed biocontrol traits typical of P. flocculosa WT. Following inundative applications, growth of P. flocculosa Act-4 was closely and almost exclusively associated with the colonies of the pathogen regardless of the powdery mildew species or the host plant tested. Development of P. flocculosa Act-4 on control leaves alone was extremely limited 24 h after its application and was typical of the epiphytic growth characterizing this type of yeast-like fungus. Based on the strong correlation between the colonization pattern of the different powdery mildew species tested and the presence of P. flocculosa Act-4, as determined by its fluorescence, it seems that growth of the BCA is dependant on the presence of powdery mildews. These results demonstrate that the GFP technology can be used to study plant-pathogen-BCA interactions and fulfill a wide array of purposes ranging from fundamental observations of the biocontrol behavior of a BCA to very applied ones serving some of the requirements for the registration of BCA's such as defining their environmental fate. PMID:17028024

  9. A new method to evaluate the biocontrol potential of single spore isolates of fungal entomopathogens

    PubMed Central

    Posada, Francisco J.; Vega, Fernando E.

    2005-01-01

    Fifty Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) strains isolated from the coffee berry borer were used to develop a novel screening method aimed at selecting strains with the highest biocontrol potential. The screening method is based on percent insect mortality, average survival time, mortality distribution, percent spore germination, fungal life cycle duration, and spore production on the insect. Based on these parameters, only 11 strains merited further study. The use of a sound scientific protocol for the selection of promising fungal entomopathogens should lead to more efficient use of time, labor, and financial resources in biological control programs. PMID:17119619

  10. Draft Whole-Genome Sequence of the Biocontrol Agent Trichoderma harzianum T6776.

    PubMed

    Baroncelli, Riccardo; Piaggeschi, Giulia; Fiorini, Lisa; Bertolini, Edoardo; Zapparata, Antonio; Pè, Mario Enrico; Sarrocco, Sabrina; Vannacci, Giovanni

    2015-01-01

    Trichoderma harzianum T6776 is a promising beneficial isolate whose effects consist of growth promotion, positive response of photosynthetic activity, hormonal signaling, and carbon partitioning in tomato, coupled with biocontrol of plant pathogens. Here, we present the first genome assembly of T6776, providing a useful platform for the scientific community. PMID:26067977

  11. Draft Whole-Genome Sequence of the Biocontrol Agent Trichoderma harzianum T6776.

    PubMed

    Baroncelli, Riccardo; Piaggeschi, Giulia; Fiorini, Lisa; Bertolini, Edoardo; Zapparata, Antonio; Pè, Mario Enrico; Sarrocco, Sabrina; Vannacci, Giovanni

    2015-06-11

    Trichoderma harzianum T6776 is a promising beneficial isolate whose effects consist of growth promotion, positive response of photosynthetic activity, hormonal signaling, and carbon partitioning in tomato, coupled with biocontrol of plant pathogens. Here, we present the first genome assembly of T6776, providing a useful platform for the scientific community.

  12. Bio-control potential of Cladosporium sp. (MCPL-461), against a noxious weed Parthenium hysterophorus L.

    PubMed

    Kumar, Anuj; Verma, V C; Gond, S K; Kumar, V; Kharwar, R N

    2009-03-01

    The phenological survey of Parthenium hysterophorus L., in and around the campus of Banaras Hindu University (BHU) was done for about two years (2004-06). During Nov 2004, a few Parthenium plants were found diseased, and symptoms were restricted to the flowers, buds, and inflorescences. The disease causes sterility and reduces seed viability, which was observed with seed germination test from infected and healthy plants. The fungal pathogen was isolated and identified as Cladosporium sp. (MCPL-461). The severity of pathogen to the reproductive organs led to serious damages of the Parthenium plants. Thus in vitro and in vivo experiments were conducted to determine the bio-control potential of Cladosporium sp. (MCPL 461) against Parthenium weed. A combinatorial effort of Cladosporium sp. (MCPL 461) bio-control potential was evaluated with different culture media, incubation periods and spores strength. Spore suspension of 10(5) to 10(12) spores ml(-1) were used to spray on healthy Parthenium plants, and it was found that severe infection symptoms were appeared at 10(10) to 10(12) spores ml(-1) suspension. LD50 was found at 10(7) spores ml(-1). To enhance the myco-herbicide activity 3% sucrose was added to the spore suspension, which further resolute the bio-control efficacy of the isolates. Only 20-30% seeds of infected plants could germinate. However the safety of non-targeted and wild plants was also tested with Lantana camera, Chromolaena odorata and found that suspension up to 10(12) spores ml(-1) were not sufficient for disease outbreak in them.

  13. Polysaccharide Production Benefits Dry Storage Survival of the Biocontrol Agent Pseudomonas fluorescens S11:P:12 Effective Against Several Maladies of Stored Potatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas fluorescens S11:P:12 (NRRL B-21133) is a biological control agent able to suppress several potato diseases and sprouting. Notably, it produces a polysaccharide during liquid cultivation; and the objective of this work was to determine the role of this material in the bio-control process...

  14. Biocontrol potential of Steinernema thermophilum and its symbiont Xenorhabdus indica against lepidopteran pests: virulence to egg and larval stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under laboratory conditions, the biocontrol potential of Steinernema thermophilum was tested against eggs and larval stages of two important lepidopteran insect pests, Helicoverpa armigera and Spodoptera litura (polyphagous pests), as well as Galleria mellonella (used as a model host) . In terms of ...

  15. Potential for bio-control of food-borne pathogens with Bacteriovorax spp. and implications for food safety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteriovorax spp. (Bvx) are delta proteobacteria adapted to marine ecosystems where salinity concentration range from 1-3%. Due to their predation of Gram-negative bacteria, Bvx may have great potential for biocontrol of food-borne pathogens on fruits and leafy greens. The goal of this research was...

  16. Structural characterization of antibiotic self-immunity tRNA synthetase in plant tumour biocontrol agent

    PubMed Central

    Chopra, Shaileja; Palencia, Andrés; Virus, Cornelia; Schulwitz, Sarah; Temple, Brenda R.; Cusack, Stephen; Reader, John

    2016-01-01

    Antibiotic-producing microbes evolved self-resistance mechanisms to avoid suicide. The biocontrol Agrobacterium radiobacter K84 secretes the Trojan Horse antibiotic agrocin 84 that is selectively transported into the plant pathogen A. tumefaciens and processed into the toxin TM84. We previously showed that TM84 employs a unique tRNA-dependent mechanism to inhibit leucyl-tRNA synthetase (LeuRS), while the TM84-producer prevents self-poisoning by expressing a resistant LeuRS AgnB2. We now identify a mechanism by which the antibiotic-producing microbe resists its own toxin. Using a combination of structural, biochemical and biophysical approaches, we show that AgnB2 evolved structural changes so as to resist the antibiotic by eliminating the tRNA-dependence of TM84 binding. Mutagenesis of key resistance determinants results in mutants adopting an antibiotic-sensitive phenotype. This study illuminates the evolution of resistance in self-immunity genes and provides mechanistic insights into a fascinating tRNA-dependent antibiotic with applications for the development of anti-infectives and the prevention of biocontrol emasculation. PMID:27713402

  17. A mutant of the nematophagous fungus Paecilomyces lilacinus (Thom) is a novel biocontrol agent for Sclerotinia sclerotiorum.

    PubMed

    Yang, Fan; Abdelnabby, Hazem; Xiao, Yannong

    2015-12-01

    Sclerotinia sclerotiorum causes severe stem rot and yield loss in oilseed rape (Brassica napus L.) and other crops worldwide. Extensive studies have been conducted on Paecilomyces lilacinus as a nematophagous bioagent. However, no reports stated the effect of P. lilacinus as a biocontrol agent against oilseed rape rot S. sclerotiorum. This study describes such effect in lab and field trials using the new transformant pt361 derived from the wild strain P. lilacinus 36-1. Unlike the wild-type strain, the mutant pt361 showed high antagonistic effect against S. Sclerotiorum A. Under lab conditions, the pt361 inhibited (65%) radial mycelial growth of S. sclerotiorum in dual culture test producing 5.9 mm inhibition zone IZ in front of the S. sclerotiorum colony. Moreover, the cell-free filtrate of pt361 culture showed strong inhibitory effects (60.3-100%) on mycelial growth of S. sclerotiorum. In leaf detached assay, pt361 significantly (p < 0.05) inhibited (40.4-97.9%) the extension of the leaf spots caused by S. sclerotiorum A at all tested concentrations. The genomic DNA sequences of the inserted T-DNA flanking obtained from pt361 strain was cloned, verified as a glycoside hydrolase 31 family by homologous analysis with other fungal strains, and named PGH31 (2556bp). Secondary structure prediction showed a domain (Glycoside hydrolase31). Three years field trial confirmed that the cell-free filtrates or spores suspension of pt361 achieved significant (p < 0.05) suppression of oilseed rape stem rot, promoted growth and increased yield compared to the control and exceeded, at dose 100%, the action of the fungicide procymidone(®). In conclusion, the mutant pt361 of P. lilacinus is a novel and promising biocontrol agent against oilseed rape Sclerotinia stem rot. PMID:26521137

  18. Endophytic fungal diversity in Theobroma cacao (cacao) and T. grandiflorum (cupuaçu) trees and their potential for growth promotion and biocontrol of black-pod disease.

    PubMed

    Hanada, Rogério Eiji; Pomella, Alan William V; Costa, Heron Salazar; Bezerra, José Luiz; Loguercio, Leandro L; Pereira, José O

    2010-01-01

    The endophytic niches of plants are a rich source of microbes that can directly and indirectly promote plant protection, growth and development. The diversity of culturable endophytic fungi from stems and branches of Theobroma cacao (cacao) and Theobroma grandiflorum (cupuaçu) trees growing in the Amazon region of Brazil was assessed. The collection of fungal endophytic isolates obtained was applied in field experiments to evaluate their potential as biocontrol agents against Phytophthora palmivora, the causal agent of the black-pod rot disease of cacao, one of the most important pathogens in cocoa-producing regions worldwide. The isolated endophytic fungi from 60 traditional, farmer-planted, healthy cacao and 10 cupuaçu plants were cultured in PDA under conditions inducing sporulation. Isolates were classified based upon the morphological characteristics of their cultures and reproductive structures. Spore suspensions from a total of 103 isolates that could be classified at least up to genus level were tested against P. palmivora in pods attached to cacao trees in the field. Results indicated that ∼70% of isolates showed biocontrol effects to a certain extent, suggesting that culturable endophytic fungal biodiversity in this system is of a mostly mutualistic type of interaction with the host. Eight isolates from genera Trichoderma (reference isolate), Pestalotiopsis, Curvularia, Tolypocladium and Fusarium showed the highest level of activity against the pathogen, and were further characterized. All demonstrated their endophytic nature by colonizing axenic cacao plantlets, and confirmed their biocontrol activity on attached pods trials by showing significant decrease in disease severity in relation to the positive control. None, however, showed detectable growth-promotion effects. Aspects related to endophytic biodiversity and host-pathogen-endophyte interactions in the environment of this study were discussed on the context of developing sustainable strategies

  19. Evaluation of yeasts from Tibetan fermented products as agents for biocontrol of blue mold of Nashi pear fruits*

    PubMed Central

    Hu, Hao; Xu, Yang; Lu, Huang-ping; Xiao, Rui; Zheng, Xiao-dong; Yu, Ting

    2015-01-01

    A total of 20 strains of yeast isolated from Tibetan fermented products were screened for antagonism against blue mold of pear caused by Penicillium expansum. Six isolates that inhibited incidence of postharvest decay by 35% or more were selected for further screening. Among them, the most effective was Rhodotorula mucilaginosa. The results showed that washed cell suspensions of R. mucilaginosa yielded better antagonistic efficacy than unwashed cell-culture mixtures, cell-free culture filtrates, and autoclaved cell cultures. Biocontrol activity improved with increasing concentrations of incubated cells. The best concentration was 1×108 cells/ml, at which the incidence of decay was only 16.7% after 6 d of incubation. The germination of conidia of P. expansum in vitro was significantly inhibited by both washed cell-suspensions and unwashed cell-culture mixtures. Rapid colonization by yeast at different concentrations showed a relationship between yeast-cell concentration and biocontrol activity. Although the titratable acidity of pear fruits increased after treatment, R. mucilaginosa did not affect the total soluble solids or ascorbic acid content. This is the first study to report that the yeast R. mucilaginosa from Tibet Autonomous Region of China may have potential as an antagonist to control the postharvest decay of pear fruits. PMID:25845361

  20. Genome Sequencing and Comparative Analysis of the Biocontrol Agent Trichoderma harzianum sensu stricto TR274

    SciTech Connect

    Steindorff, Andrei S.; Noronha, Elilane F.; Ulhoa, Cirano J.; Kuo, Alan; Salamov, Asaf A.; Haridas, Sajeet; Riley, Robert W.; Druzhinina, Irina S.; Kubicek, Christian P.; Grigoriev, Igor V.

    2015-03-17

    Biological control is a complex process which requires many mechanisms and a high diversity of biochemical pathways. The species of Trichoderma harzianum are well known for their biocontrol activity against many plant pathogens. To gain new insights into the biocontrol mechanism used by T. harzianum, we sequenced the isolate TR274 genome using Illumina. The assembly was performed using AllPaths-LG with a maximum coverage of 100x. The assembly resulted in 2282 contigs with a N50 of 37033bp. The genome size generated was 40.8 Mb and the GC content was 47.7%, similar to other Trichoderma genomes. Using the JGI Annotation Pipeline we predicted 13,932 genes with a high transcriptome support. CEGMA tests suggested 100% genome completeness and 97.9% of RNA-SEQ reads were mapped to the genome. The phylogenetic comparison using orthologous proteins with all Trichoderma genomes sequenced at JGI, corroborates the Trichoderma (T. asperellum and T. atroviride), Longibrachiatum (T. reesei and T. longibrachiatum) and Pachibasium (T. harzianum and T. virens) section division described previously. The comparison between two Trichoderma harzianum species suggests a high genome similarity but some strain-specific expansions. Analyses of the secondary metabolites, CAZymes, transporters, proteases, transcription factors were performed. The Pachybasium section expanded virtually all categories analyzed compared with the other sections, specially Longibrachiatum section, that shows a clear contraction. These results suggests that these proteins families have an important role in their respective phenotypes. Future analysis will improve the understanding of this complex genus and give some insights about its lifestyle and the interactions with the environment.

  1. Bacteriophage biocontrol of foodborne pathogens.

    PubMed

    Kazi, Mustafa; Annapure, Uday S

    2016-03-01

    Bacteriophages are viruses that only infect bacterial cells. Phages are categorized based on the type of their life cycle, the lytic cycle cause lysis of the bacterium with the release of multiple phage particles where as in lysogenic phase the phage DNA is incorporated into the bacterial genome. Lysogeny does not result in lysis of the host. Lytic phages have several potential applications in the food industry as biocontrol agents, biopreservatives and as tools for detecting pathogens. They have also been proposed as alternatives to antibiotics in animal health. Two unique features of phage relevant for food safety are that they are harmless to mammalian cells and high host specificity, keeping the natural microbiota undisturbed. However, the recent approval of bacteriophages as food additives has opened the discussion about 'edible viruses'. This article reviews in detail the application of phages for the control of foodborne pathogens in a process known as "biocontrol". PMID:27570260

  2. Identification of volatiles produced by Cladosporium cladosporioides CL-1, a fungal biocontrol agent that promotes plant growth.

    PubMed

    Paul, Diby; Park, Kyung Seok

    2013-10-16

    Certain microbial Volatile Organic Compounds (VOCs) have been reported to enhance the growth and development of plants. The biocontrol fungi, Cladosporium cladosporioides CL-1 significantly improved the growth of tobacco seedlings in vitro when they were co-cultivated without physical contact. SPME Quadrupole GC/MS/MS revealed that CL-1 emited the volatiles α-pinene, (-)-trans-caryophyllene, tetrahydro-2,2,5,5-tetramethylfuran, dehydroaromadendrene, and (+)-sativene. Potential roles of these volatiles in plant growth and development are discussed. Even though there were several fungal VOCs reported in the past that could influence plant growth, their exact mechanisms of action are not fully known. Fungal VOC-mediated plant growth promotion requires in-depth study in order for this technology to be used in large scale for crops, especially those grown under greenhouse conditions.

  3. The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis.

    PubMed

    Jeffries, Claire L; Walker, Thomas

    2015-01-01

    Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE) in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000-175,000, with 25%-30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a "dead-end" host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia) mosquitoes has resulted in the generation of "dengue-refractory" mosquito lines. The successful

  4. The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis

    PubMed Central

    Jeffries, Claire L.; Walker, Thomas

    2015-01-01

    Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE) in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000–175,000, with 25%–30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a “dead-end” host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia) mosquitoes has resulted in the generation of “dengue-refractory” mosquito lines

  5. The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis.

    PubMed

    Jeffries, Claire L; Walker, Thomas

    2015-01-01

    Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE) in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000-175,000, with 25%-30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a "dead-end" host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia) mosquitoes has resulted in the generation of "dengue-refractory" mosquito lines. The successful

  6. Bacillus amyloliquefaciens subsp. plantarum GR53, a potent biocontrol agent resists Rhizoctonia disease on Chinese cabbage through hormonal and antioxidants regulation.

    PubMed

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; Lee, In-Jung

    2015-10-01

    The fungus Rhizoctonia solani is one of the causal agents of numerous diseases that affect crop growth and yield. The aim of this present investigation was to identify a biocontrol agent that acts against R. solani and to determine the agent's protective effect through phytohormones and antioxidant regulation in experimentally infected Chinese cabbage plants. Four rhizospheric soil bacterial isolates GR53, GR169, GR786, and GR320 were tested for their antagonistic activity against R. solani. Among these isolates, GR53 significantly suppressed fungal growth. GR53 was identified as Bacillus amyloliquefaciens subsp. plantarum by phylogenetic analysis of the 16S rDNA sequence. The biocontrol activity of B. amyloliquefaciens subsp. plantarum GR53 was tested in Chinese cabbage plants under controlled conditions. Results showed that R. solani inhibited plant growth (length, width, fresh and dry weight of leaves) by reducing chlorophyll and total phenolic content, as well as by increasing the levels of salicylic acid, jasmonic acid, abscisic acid, and DPPH scavenging activity. By regulating the levels of these compounds, the co-inoculation of B. amyloliquefaciens subsp. plantarum GR53 heightened induced systemic resistance in infected Chinese cabbage, effectively mitigating R. solani-induced damaging effects and improving plant growth. The results obtained from this study suggest that B. amyloliquefaciens subsp. plantarum GR53 is an effective biocontrol agent to prevent the damage caused by R. solani in Chinese cabbage plants.

  7. Bacillus amyloliquefaciens subsp. plantarum GR53, a potent biocontrol agent resists Rhizoctonia disease on Chinese cabbage through hormonal and antioxidants regulation.

    PubMed

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; Lee, In-Jung

    2015-10-01

    The fungus Rhizoctonia solani is one of the causal agents of numerous diseases that affect crop growth and yield. The aim of this present investigation was to identify a biocontrol agent that acts against R. solani and to determine the agent's protective effect through phytohormones and antioxidant regulation in experimentally infected Chinese cabbage plants. Four rhizospheric soil bacterial isolates GR53, GR169, GR786, and GR320 were tested for their antagonistic activity against R. solani. Among these isolates, GR53 significantly suppressed fungal growth. GR53 was identified as Bacillus amyloliquefaciens subsp. plantarum by phylogenetic analysis of the 16S rDNA sequence. The biocontrol activity of B. amyloliquefaciens subsp. plantarum GR53 was tested in Chinese cabbage plants under controlled conditions. Results showed that R. solani inhibited plant growth (length, width, fresh and dry weight of leaves) by reducing chlorophyll and total phenolic content, as well as by increasing the levels of salicylic acid, jasmonic acid, abscisic acid, and DPPH scavenging activity. By regulating the levels of these compounds, the co-inoculation of B. amyloliquefaciens subsp. plantarum GR53 heightened induced systemic resistance in infected Chinese cabbage, effectively mitigating R. solani-induced damaging effects and improving plant growth. The results obtained from this study suggest that B. amyloliquefaciens subsp. plantarum GR53 is an effective biocontrol agent to prevent the damage caused by R. solani in Chinese cabbage plants. PMID:26160009

  8. Novel Trichoderma polysporum Strain for the Biocontrol of Pseudogymnoascus destructans, the Fungal Etiologic Agent of Bat White Nose Syndrome.

    PubMed

    Zhang, Tao; Chaturvedi, Vishnu; Chaturvedi, Sudha

    2015-01-01

    White-nose syndrome (WNS), an emerging disease of hibernating bats, has rapidly spread across eastern North America killing millions of bats. Pseudogymnoascus destructans (Pd), the sole etiologic agent of WNS, is widespread and persistent in bat hibernacula. Control of Pd in the affected sites is urgently needed to break the transmission cycle while minimizing any adverse impact on the native organisms. We isolated a novel strain of Trichoderma polysporum (Tp) from one of the caves at the epicenter of WNS zoonotic. Detailed experimental studies revealed: (1) Tp WPM 39143 was highly adapted to grow at temperatures simulating the cave environment (6°C-15°C), (2) Tp WPM 39143 restricted Pd colony growth in dual culture challenges, (3) Tp WPM 39143 caused four logs reduction of Pd colony forming units and genome copies in autoclaved soil samples from one of the WNS affected caves, (4) Tp WPM 39143 extract showed specific fungicidal activity against Pd in disk diffusion assay, but not against closely related fungus P. pannorum (Pp), (5) Tp WPM 39143 extract retained inhibitory activity after exposure to high temperatures, light and proteinase K, and (6) Inhibitory metabolites in Tp WPM 39143 extract comprised of water-soluble, high polarity compounds. These results suggest that Tp WPM 39143 is a promising candidate for further evaluation as a biocontrol agent of Pd in WNS affected sites. PMID:26509269

  9. Novel Trichoderma polysporum Strain for the Biocontrol of Pseudogymnoascus destructans, the Fungal Etiologic Agent of Bat White Nose Syndrome

    PubMed Central

    Zhang, Tao; Chaturvedi, Vishnu; Chaturvedi, Sudha

    2015-01-01

    White-nose syndrome (WNS), an emerging disease of hibernating bats, has rapidly spread across eastern North America killing millions of bats. Pseudogymnoascus destructans (Pd), the sole etiologic agent of WNS, is widespread and persistent in bat hibernacula. Control of Pd in the affected sites is urgently needed to break the transmission cycle while minimizing any adverse impact on the native organisms. We isolated a novel strain of Trichoderma polysporum (Tp) from one of the caves at the epicenter of WNS zoonotic. Detailed experimental studies revealed: (1) Tp WPM 39143 was highly adapted to grow at temperatures simulating the cave environment (6°C-15°C), (2) Tp WPM 39143 restricted Pd colony growth in dual culture challenges, (3) Tp WPM 39143 caused four logs reduction of Pd colony forming units and genome copies in autoclaved soil samples from one of the WNS affected caves, (4) Tp WPM 39143 extract showed specific fungicidal activity against Pd in disk diffusion assay, but not against closely related fungus P. pannorum (Pp), (5) Tp WPM 39143 extract retained inhibitory activity after exposure to high temperatures, light and proteinase K, and (6) Inhibitory metabolites in Tp WPM 39143 extract comprised of water-soluble, high polarity compounds. These results suggest that Tp WPM 39143 is a promising candidate for further evaluation as a biocontrol agent of Pd in WNS affected sites. PMID:26509269

  10. Host-Range Dynamics of Cochliobolus lunatus: From a Biocontrol Agent to a Severe Environmental Threat

    PubMed Central

    Louis, Bengyella; Waikhom, Sayanika Devi; Roy, Pranab; Bhardwaj, Pardeep Kumar; Sharma, Chandradev K.; Singh, Mohendro Wakambam; Talukdar, Narayan Chandra

    2014-01-01

    We undertook an investigation to advance understanding of the host-range dynamics and biocontrol implications of Cochliobolus lunatus in the past decade. Potato (Solanum tuberosum L) farms were routinely surveyed for brown-to-black leaf spot disease caused by C. lunatus. A biphasic gene data set was assembled and databases were mined for reported hosts of C. lunatus in the last decade. The placement of five virulent strains of C. lunatus causing foliar necrosis of potato was studied with microscopic and phylogenetic tools. Analysis of morphology showed intraspecific variations in stromatic tissues among the virulent strains causing foliar necrosis of potato. A maximum likelihood inference based on GPDH locus separated C. lunatus strains into subclusters and revealed the emergence of unclustered strains. The evolving nutritional requirement of C. lunatus in the last decade is exhibited by the invasion of vertebrates, invertebrates, dicots, and monocots. Our results contribute towards a better understanding of the host-range dynamics of C. lunatus and provide useful implications on the threat posed to the environment when C. lunatus is used as a mycoherbicide. PMID:24987680

  11. Complete genome sequence of Pseudomonas fluorescens strain PICF7, an indigenous root endophyte from olive (Olea europaea L.) and effective biocontrol agent against Verticillium dahliae.

    PubMed

    Martínez-García, Pedro Manuel; Ruano-Rosa, David; Schilirò, Elisabetta; Prieto, Pilar; Ramos, Cayo; Rodríguez-Palenzuela, Pablo; Mercado-Blanco, Jesús

    2015-01-01

    Pseudomonas fluorescens strain PICF7 is a native endophyte of olive roots. Previous studies have shown this motile, Gram-negative, non-sporulating bacterium is an effective biocontrol agent against the soil-borne fungus Verticillium dahliae, the causal agent of one of the most devastating diseases for olive (Olea europaea L.) cultivation. Here, we announce and describe the complete genome sequence of Pseudomonas fluorescens strain PICF7 consisting of a circular chromosome of 6,136,735 bp that encodes 5,567 protein-coding genes and 88 RNA-only encoding genes. Genome analysis revealed genes predicting factors such as secretion systems, siderophores, detoxifying compounds or volatile components. Further analysis of the genome sequence of PICF7 will help in gaining insights into biocontrol and endophytism.

  12. Complete genome sequence of Pseudomonas fluorescens strain PICF7, an indigenous root endophyte from olive (Olea europaea L.) and effective biocontrol agent against Verticillium dahliae

    PubMed Central

    2015-01-01

    Pseudomonas fluorescens strain PICF7 is a native endophyte of olive roots. Previous studies have shown this motile, Gram-negative, non-sporulating bacterium is an effective biocontrol agent against the soil-borne fungus Verticillium dahliae, the causal agent of one of the most devastating diseases for olive (Olea europaea L.) cultivation. Here, we announce and describe the complete genome sequence of Pseudomonas fluorescens strain PICF7 consisting of a circular chromosome of 6,136,735 bp that encodes 5,567 protein-coding genes and 88 RNA-only encoding genes. Genome analysis revealed genes predicting factors such as secretion systems, siderophores, detoxifying compounds or volatile components. Further analysis of the genome sequence of PICF7 will help in gaining insights into biocontrol and endophytism. PMID:25685259

  13. Complete genome sequence of Pseudomonas fluorescens strain PICF7, an indigenous root endophyte from olive (Olea europaea L.) and effective biocontrol agent against Verticillium dahliae.

    PubMed

    Martínez-García, Pedro Manuel; Ruano-Rosa, David; Schilirò, Elisabetta; Prieto, Pilar; Ramos, Cayo; Rodríguez-Palenzuela, Pablo; Mercado-Blanco, Jesús

    2015-01-01

    Pseudomonas fluorescens strain PICF7 is a native endophyte of olive roots. Previous studies have shown this motile, Gram-negative, non-sporulating bacterium is an effective biocontrol agent against the soil-borne fungus Verticillium dahliae, the causal agent of one of the most devastating diseases for olive (Olea europaea L.) cultivation. Here, we announce and describe the complete genome sequence of Pseudomonas fluorescens strain PICF7 consisting of a circular chromosome of 6,136,735 bp that encodes 5,567 protein-coding genes and 88 RNA-only encoding genes. Genome analysis revealed genes predicting factors such as secretion systems, siderophores, detoxifying compounds or volatile components. Further analysis of the genome sequence of PICF7 will help in gaining insights into biocontrol and endophytism. PMID:25685259

  14. Biocontrol agents-mediated suppression of oxalic acid induced cell death during Sclerotinia sclerotiorum-pea interaction.

    PubMed

    Jain, Akansha; Singh, Akanksha; Singh, Surendra; Sarma, Birinchi Kumar; Singh, Harikesh Bahadur

    2015-05-01

    Oxalic acid (OA) is an important pathogenic factor during early Sclerotinia sclerotiorum-host interaction and might work by reducing hydrogen peroxide production (H2 O2 ). In the present investigation, oxalic acid-induced cell death in pea was studied. Pea plants treated with biocontrol agents (BCAs) viz., Pseudomonas aeruginosa PJHU15, Bacillus subtilis BHHU100, and Trichoderma harzianum TNHU27 either singly and/or in consortium acted on S. sclerotiorum indirectly by enabling plants to inhibit the OA-mediated suppression of oxidative burst via induction of H2 O2 . Our results showed that BCA treated plants upon treatment with culture filtrate of the pathogen, conferred the resistance via. significantly decreasing relative cell death of pea against S. sclerotiorum compared to control plants without BCA treatment but treated with the culture filtrate of the pathogen. The results obtained from the present study indicate that the microbes especially in consortia play significant role in protection against S. sclerotiorum by modulating oxidative burst and partially enhancing tolerance by increasing the H2 O2 generation, which is otherwise suppressed by OA produced by the pathogen.

  15. A comparison of four geographic sources of the biocontrol agent Prokelisia marginata (Homoptera: Delphacidae) following introduction into a common environment.

    PubMed

    Grevstad, F S; O'Casey, C; Katz, M L

    2012-06-01

    As part of a biological control program against Spartina alterniflora Loisel. (smooth cordgrass), we simultaneously released populations of the planthopper Prokelisia marginata (van Duzee) from four geographic areas in each of five replicate field sites in the Willapa Bay estuary in Washington State. The four sources (California, Georgia, Virginia, and Rhode Island) have varying climate and seasonal regimes. We expected local adaptations would affect performance in the new environment. Using vacuum sampling, we measured population densities in spring and fall for 2 yr after release. In addition, we measured the timing of spring emergence through bi-weekly surveys of the number of nymphs residing in overwintering sites (curled leaves of senesced Spartina culms) versus on live green shoots. The observed sequence of emergence GA>CA>VA>RI was consistent with the hypothesis that this insect responds to a photoperiod cue for emergence timing. The four populations also differed in their reproductive capacity as measured by the increase in population densities over the summer months. Overall, the California and Rhode Island populations had higher population growth than those from Virginia and Georgia. Our results suggest that the climate and seasonal adaptations of biocontrol agents should be carefully considered as they can affect the performance and phenology in the new range. At the same time, it is noteworthy that all four populations were capable of establishing and growing, indicating a degree of resiliency for populations experiencing a rapid change in climate. PMID:22732601

  16. Bacteriocins as Potential Anticancer Agents

    PubMed Central

    Kaur, Sumanpreet; Kaur, Sukhraj

    2015-01-01

    Cancer remains one of the leading causes of deaths worldwide, despite advances in its treatment and detection. The conventional chemotherapeutic agents used for the treatment of cancer have non-specific toxicity toward normal body cells that cause various side effects. Secondly, cancer cells are known to develop chemotherapy resistance in due course of treatment. Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeutic potential of bacteriocins against various types of cancer cell lines. Bacteriocins are ribosomally-synthesized cationic peptides secreted by almost all groups of bacteria. Some bacteriocins have shown selective cytotoxicity toward cancer cells as compared to normal cells. This makes them promising candidates for further investigation and clinical trials. In this review article, we present the overview of the various cancer cell-specific cytotoxic bacteriocins, their mode of action and efficacies. PMID:26617524

  17. Bacteriocins as Potential Anticancer Agents.

    PubMed

    Kaur, Sumanpreet; Kaur, Sukhraj

    2015-01-01

    Cancer remains one of the leading causes of deaths worldwide, despite advances in its treatment and detection. The conventional chemotherapeutic agents used for the treatment of cancer have non-specific toxicity toward normal body cells that cause various side effects. Secondly, cancer cells are known to develop chemotherapy resistance in due course of treatment. Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeutic potential of bacteriocins against various types of cancer cell lines. Bacteriocins are ribosomally-synthesized cationic peptides secreted by almost all groups of bacteria. Some bacteriocins have shown selective cytotoxicity toward cancer cells as compared to normal cells. This makes them promising candidates for further investigation and clinical trials. In this review article, we present the overview of the various cancer cell-specific cytotoxic bacteriocins, their mode of action and efficacies.

  18. Plant growth-promoting traits of biocontrol potential bacteria isolated from rice rhizosphere.

    PubMed

    Gopalakrishnan, Subramaniam; Upadhyaya, Hd; Vadlamudi, Srinivas; Humayun, Pagidi; Vidya, Meesala Sree; Alekhya, Gottumukkala; Singh, Amit; Vijayabharathi, Rajendran; Bhimineni, Ratna Kumari; Seema, Murali; Rathore, Abhishek; Rupela, Om

    2012-12-01

    Seven isolates of bacteria (SRI-156, SRI-158, SRI-178, SRI-211, SRI-229, SRI-305 and SRI-360) were earlier reported by us as having potential for biocontrol of charcoal rot of sorghum and plant growth promotion (PGP) of the plant. In the present study, the seven isolates were characterized for their physiological traits (tolerance to salinity, pH, temperature and resistance to antibiotics and fungicides) and further evaluated in the field for their PGP of rice. All the seven isolates were able to grow at pH values between 5 and 13, in NaCl concentrations of up to 8% (except SRI-156 and SRI-360), temperatures between 20 and 40°C and were resistant to ampicillin (>100 ppm; except SRI-158 and SRI-178) but sensitive (<10 ppm) to chloramphenicol, kanamycin, nalidixic acid, streptomycin (except SRI-156 and SRI-211) and tetracycline. They were tolerant to fungicides benlate and captan, except SRI-158 and SRI-178, bavistin and sensitive to thiram (except SRI-156 and SRI-211) at field application level. In the field, four of the seven isolates (SRI-158, SRI-211, SRI-229 and SRI-360) significantly enhanced the tiller numbers, stover and grain yields, total dry matter, root length, volume and dry weight over the un-inoculated control. In the rhizosphere soil at harvest, all the isolates significantly enhanced microbial biomass carbon (except SRI-156), microbial biomass nitrogen and dehydrogenase activity (up to 33%, 36% and 39%, respectively) and total N, available P and% organic carbon (up to 10%, 38% and 10%, respectively) compared to the control. This investigation further confirms that the SRI isolates have PGP properties.

  19. Peptaibol, secondary-metabolite, and hydrophobin pattern of commercial biocontrol agents formulated with species of the Trichoderma harzianum complex.

    PubMed

    Degenkolb, Thomas; Fog Nielsen, Kristian; Dieckmann, Ralf; Branco-Rocha, Fabiano; Chaverri, Priscila; Samuels, Gary J; Thrane, Ulf; von Döhren, Hans; Vilcinskas, Andreas; Brückner, Hans

    2015-04-01

    The production of bioactive polypeptides (peptaibiotics) in vivo is a sophisticated adaptation strategy of both mycoparasitic and saprotrophic Trichoderma species for colonizing and defending their natural habitats. This feature is of major practical importance, as the detection of peptaibiotics in plant-protective Trichoderma species, which are successfully used against economically relevant bacterial and fungal plant pathogens, certainly contributes to a better understanding of these complex antagonistic interactions. We analyzed five commercial biocontrol agents (BCAs), namely Canna(®) , Trichosan(®) , Vitalin(®) , Promot(®) WP, and TrichoMax(®) , formulated with recently described species of the Trichoderma harzianum complex, viz. T. afroharzianum, T. simmonsii, and T. guizhouense. By using the well-established, HPLC/MS-based peptaibiomics approach, it could unequivocally be demonstrated that all of these formulations contained new and recurrent peptaibols, i.e., peptaibiotics carrying an acetylated N-terminus, the C-terminus of which is reduced to a 1,2-amino alcohol. Their chain lengths, including the amino alcohol, were 11, 14, and 18 residues, respectively. Peptaibols were also to be the dominating secondary metabolites in plate cultures of the four strains obtained from four of the Trichoderma- based BCAs, contributing 95% of the UHPLC-UV/VIS peak areas and 99% of the total ion count MS peak area from solid media. Furthermore, species-specific hydrophobins, as well as non-peptaibiotic secondary metabolites, were detected, the latter being known for their antifungal, siderophore, or plant-growth-promoting activities. Notably, none of the isolates produced low-molecular weight mycotoxins. PMID:25879509

  20. Peptaibol, secondary-metabolite, and hydrophobin pattern of commercial biocontrol agents formulated with species of the Trichoderma harzianum complex.

    PubMed

    Degenkolb, Thomas; Fog Nielsen, Kristian; Dieckmann, Ralf; Branco-Rocha, Fabiano; Chaverri, Priscila; Samuels, Gary J; Thrane, Ulf; von Döhren, Hans; Vilcinskas, Andreas; Brückner, Hans

    2015-04-01

    The production of bioactive polypeptides (peptaibiotics) in vivo is a sophisticated adaptation strategy of both mycoparasitic and saprotrophic Trichoderma species for colonizing and defending their natural habitats. This feature is of major practical importance, as the detection of peptaibiotics in plant-protective Trichoderma species, which are successfully used against economically relevant bacterial and fungal plant pathogens, certainly contributes to a better understanding of these complex antagonistic interactions. We analyzed five commercial biocontrol agents (BCAs), namely Canna(®) , Trichosan(®) , Vitalin(®) , Promot(®) WP, and TrichoMax(®) , formulated with recently described species of the Trichoderma harzianum complex, viz. T. afroharzianum, T. simmonsii, and T. guizhouense. By using the well-established, HPLC/MS-based peptaibiomics approach, it could unequivocally be demonstrated that all of these formulations contained new and recurrent peptaibols, i.e., peptaibiotics carrying an acetylated N-terminus, the C-terminus of which is reduced to a 1,2-amino alcohol. Their chain lengths, including the amino alcohol, were 11, 14, and 18 residues, respectively. Peptaibols were also to be the dominating secondary metabolites in plate cultures of the four strains obtained from four of the Trichoderma- based BCAs, contributing 95% of the UHPLC-UV/VIS peak areas and 99% of the total ion count MS peak area from solid media. Furthermore, species-specific hydrophobins, as well as non-peptaibiotic secondary metabolites, were detected, the latter being known for their antifungal, siderophore, or plant-growth-promoting activities. Notably, none of the isolates produced low-molecular weight mycotoxins.

  1. Studies of plant colonisation by closely related Bacillus amyloliquefaciens biocontrol agents using strain specific quantitative PCR assays.

    PubMed

    Johansson, Anna H; Bejai, Sarosh; Niazi, Adnan; Manzoor, Shahid; Bongcam-Rudloff, Erik; Meijer, Johan

    2014-12-01

    Certain strains of Bacillus amyloliquefaciens can colonize plants and improve growth and stress management. In order to study these effects, bacterial growth dynamics on plants and in the rhizosphere are of interest calling for specific analytical tools. For that purpose, quantitative real-time PCR (qPCR) assays were developed in order to differentiate among three closely related B. amyloliquefaciens subsp. plantarum strains (UCMB5033, UCMB5036, UCMB5113) and to determine their levels with high accuracy. Oligonucleotide primers were designed for strain unique gene sequences and used for SYBR green based qPCR analysis. Standard curves covered a wide linear range (10(6)) of DNA amounts with the lowest detection level at 50 fg. Post-reaction melting curve analysis showed only a single product. Accurate threshold cycles were obtained, even in the presence of high excess of related Bacillus strains and total bacterial DNA from soil. Analysis of Bacillus colonisation after seed treatment of two oilseed rape cultivars (Oase and Ritz) grown on agar support showed a time dependent effect but that the bacteria mostly were found on root tissues and little on green tissues. The colonisation on plants grown in soil varied among the Bacillus strains where Oase seemed to house more bacteria than Ritz. Applied as a mixture, all three Bacillus strains co-existed on the roots of plants grown in soil. The qPCR assay in combination with other techniques will be a powerful tool to study plant interactions of these B. amyloliquefaciens biocontrol agents to further understand the requirements for successful interactions and improvement of plant properties.

  2. Osmotically induced trehalose and glycine betaine accumulation improves tolerance to desiccation, survival and efficacy of the postharvest biocontrol agent Pantoea agglomerans EPS125.

    PubMed

    Bonaterra, Anna; Camps, Jaume; Montesinos, Emilio

    2005-09-01

    The application of the biocontrol agent Pantoea agglomerans EPS125 to unwounded fruits was practically ineffective for control of postharvest blue mould caused by Penicillium expansum when the treatment and subsequent wounding and pathogen inoculation were separated by periods of unfavourable conditions. This was due to a rapid decrease in viability of the alocthonous introduced biocontrol agent in the intact peel surface. A system for osmoadaptation of the biocontrol agent was developed by combining saline osmotic stress and osmolyte amendment to the growth medium. Osmoadapted cells accumulated trehalose and glycine betaine (GB) intracellularly and showed a higher tolerance to desiccation than non-osmoadapted cells. Osmoadaptation in NaCl plus GB during inoculum preparation increased considerably survival on the peel surface of apple fruits. This effect was significant under low relative humidity (RH) and fluctuating RH conditions, but was not significant at high RH. Osmoadaptation significantly improved blue mould control under conditions where the standard biological control treatments were ineffective. The rot diameter was significantly reduced in apple fruits which were treated with EPS125 and incubated for several days under low, high or fluctuating RH, followed by wounding and inoculation of P. expansum. Growth of EPS125 with NaCl, either with or without the addition of GB, was an effective osmoadaptation treatment for improving blue mould rot control. However, the addition of GB to the NaCl amended growth medium increased 4-5-fold growth rate and OD of the cultures. This is an advantage for mass production of P. agglomerans EPS125 in a NaCl amended growth medium.

  3. Effects of plant virus and its insect vector on Encarsia formosa, a biocontrol agent of whiteflies

    PubMed Central

    Liu, Xiaoyuan; Xiang, Wensheng; Jiao, Xiaoguo; Zhang, Youjun; Xie, Wen; Wu, Qingjun; Zhou, Xuguo; Wang, Shaoli

    2014-01-01

    In this study, we investigated the tritrophic interactions among a persistently transmitted plant virus, Tomato yellow leaf curl virus (TYLCV), its insect vector, the sweetpotato whitefly Bemisia tabaci, and a parasitoid, Encarsia formosa Gahan, one of the most extensively used biological control agents. As an emerging invasive pest worldwide, the two most damaging whiteflies are B. tabaci B and Q cryptic species. On healthy tomato plants, parasitoid-induced mortality was significantly higher in B. tabaci B than in Q. In contrast, similar mortality levels of B and Q were observed on TYLCV-infected plants. A higher rate of parasitism was consistently observed in B, independent of the TYLCV infection. Similarly, the life history traits of E. formosa were influenced by both TYLCV and the two cryptic species of B. tabaci. Specifically, E. formosa parasitizing B had a greater adult longevity and shorter developmental time on healthy plants, whereas the parasitoids developing from Q has a greater adult longevity on TYLCV-infected plants. The emergence rate of E. formosa was unaffected by either B. tabaci cryptic species or the virus. These results suggest that the vector-borne pathogen can manipulate the host suitability of a parasitoid and hence the parasitoid-host interactions. PMID:25096549

  4. Effects of plant virus and its insect vector on Encarsia formosa, a biocontrol agent of whiteflies.

    PubMed

    Liu, Xiaoyuan; Xiang, Wensheng; Jiao, Xiaoguo; Zhang, Youjun; Xie, Wen; Wu, Qingjun; Zhou, Xuguo; Wang, Shaoli

    2014-01-01

    In this study, we investigated the tritrophic interactions among a persistently transmitted plant virus, Tomato yellow leaf curl virus (TYLCV), its insect vector, the sweetpotato whitefly Bemisia tabaci, and a parasitoid, Encarsia formosa Gahan, one of the most extensively used biological control agents. As an emerging invasive pest worldwide, the two most damaging whiteflies are B. tabaci B and Q cryptic species. On healthy tomato plants, parasitoid-induced mortality was significantly higher in B. tabaci B than in Q. In contrast, similar mortality levels of B and Q were observed on TYLCV-infected plants. A higher rate of parasitism was consistently observed in B, independent of the TYLCV infection. Similarly, the life history traits of E. formosa were influenced by both TYLCV and the two cryptic species of B. tabaci. Specifically, E. formosa parasitizing B had a greater adult longevity and shorter developmental time on healthy plants, whereas the parasitoids developing from Q has a greater adult longevity on TYLCV-infected plants. The emergence rate of E. formosa was unaffected by either B. tabaci cryptic species or the virus. These results suggest that the vector-borne pathogen can manipulate the host suitability of a parasitoid and hence the parasitoid-host interactions. PMID:25096549

  5. Biocontrol of Rhizoctonia solani, the causal agent of bean damping-off by fluorescent pseudomonads.

    PubMed

    Afsharmanesh, H; Ahmadzadeh, M; Sharifi-Tehrani, A

    2006-01-01

    Rhizosphere bacteria belonging to the fluorescent pseudomonads are receiving increasing attention for the protection of plants against soil-borne fungal pathogens. Among these pathogens, Rhizoctonia solani, the causal agent of bean damping- off is very important in bean fields of Iran. In this study, the antagonistic activity of 46 isolates of fluorescent pseudomonads (isolated from different area of Iran) and Pseudomonas fluorescens strain CHA0 investigated against one isolate of R. solani. About 64% of isolates revealed antagonistic activity against R. solani. Production of antifungal metabolites such as HCN, siderophore and protease was evaluated. The results showed that 97.8%, 17% and 78% of isolates produced siderophore, HCN and protease respectively. There was no significant correlation between antagonistic activity and production of these metabolites. Isolates P-5, P-10 and P-32 with strain CHA0 were selected in order to investigate involvement of siderophore, volatile metabolites (HCN), and non-volatile metabolites in reducing mycelial growth of R. olani. Isolate P-5 showed much more inhibitory effect by production of volatile metabolites and siderophore. Non-volatile metabolites in isolates P-32 and P-5 completely inhibited mycelial growth of the fungus. After the primary labrotory tests, isolates P-14, P-35, P-30, P-5 and strain CHA0 were selected for in vivo experiments. These selected isolates with benomyl fungicide were used as seed coating and soil drenching in sterile soil under greenhouse condition. The result indicated that in seed treatment method, isolates P-30 by 66% had the most effect in disease reduction while in soil treatment method, strain CHAO by 60% had the most effect, such that this two isolates showed significant differences in comparison with plants inoculated with R. solani inoculums.

  6. Marine yeasts as biocontrol agents and producers of bio-products.

    PubMed

    Chi, Zhen-Ming; Liu, Guanglei; Zhao, Shoufeng; Li, Jing; Peng, Ying

    2010-05-01

    As some species of marine yeasts can colonize intestine of marine animals, they can be used as probiotics. It has been reported that beta-glucans from marine yeast cells can be utilized as immuno-stimulants in marine animals. Some siderophores or killer toxins produced by marine yeasts have ability to inhibit growth of pathogenic bacteria or kill pathogenic yeasts in marine animals. The virulent factors from marine pathogens can be genetically displayed on marine yeast cells, and the yeast cells displaying the virulent factors can stimulate marine animals to produce specific antibody against the pathogens. Some marine yeast cells are rich in proteins and essential amino acids and can be used in nutrition for marine animals. The marine yeast cells rich in lipid can be used for biodiesel production. Recently, it has been reported that some strains of Yarrowia lipolytica isolated from marine environments can produce nanoparticles. Because many marine yeasts can remove organic pollutants and heavy metals, they can be applied to remediation of marine environments. It has been shown that the enzymes produced by some marine yeasts have many unique properties and many potential applications. PMID:20195858

  7. Investigating the compatibility of the biocontrol agent Clonostachys rosea IK726 with prodigiosin-producing Serratia rubidaea S55 and phenazine-producing Pseudomonas chlororaphis ToZa7.

    PubMed

    Kamou, Nathalie N; Dubey, Mukesh; Tzelepis, Georgios; Menexes, Georgios; Papadakis, Emmanouil N; Karlsson, Magnus; Lagopodi, Anastasia L; Jensen, Dan Funck

    2016-05-01

    This study was carried out to assess the compatibility of the biocontrol fungus Clonostachys rosea IK726 with the phenazine-producing Pseudomonas chlororaphis ToZa7 or with the prodigiosin-producing Serratia rubidaea S55 against Fusarium oxysporum f. sp. radicis-lycopersici. The pathogen was inhibited by both strains in vitro, whereas C. rosea displayed high tolerance to S. rubidaea but not to P. chlororaphis. We hypothesized that this could be attributed to the ATP-binding cassette (ABC) proteins. The results of the reverse transcription quantitative PCR showed an induction of seven genes (abcB1, abcB20, abcB26, abcC12, abcC12, abcG8 and abcG25) from subfamilies B, C and G. In planta experiments showed a significant reduction in foot and root rot on tomato plants inoculated with C. rosea and P. chlororaphis. This study demonstrates the potential for combining different biocontrol agents and suggests an involvement of ABC transporters in secondary metabolite tolerance in C. rosea.

  8. Genetic Control of Plant Root Colonization by the Biocontrol agent, Pseudomonas fluorescens

    SciTech Connect

    Cole, Benjamin J.; Fletcher, Meghan; Waters, Jordan; Wetmore, Kelly; Blow, Matthew J.; Deutschbauer, Adam M.; Dangl, Jeffry L.; Visel, Axel

    2015-03-19

    Plant growth promoting rhizobacteria (PGPR) are a critical component of plant root ecosystems. PGPR promote plant growth by solubilizing inaccessible minerals, suppressing pathogenic microorganisms in the soil, and directly stimulating growth through hormone synthesis. Pseudomonas fluorescens is a well-established PGPR isolated from wheat roots that can also colonize the root system of the model plant, Arabidopsis thaliana. We have created barcoded transposon insertion mutant libraries suitable for genome-wide transposon-mediated mutagenesis followed by sequencing (TnSeq). These libraries consist of over 105 independent insertions, collectively providing loss-of-function mutants for nearly all genes in the P.fluorescens genome. Each insertion mutant can be unambiguously identified by a randomized 20 nucleotide sequence (barcode) engineered into the transposon sequence. We used these libraries in a gnotobiotic assay to examine the colonization ability of P.fluorescens on A.thaliana roots. Taking advantage of the ability to distinguish individual colonization events using barcode sequences, we assessed the timing and microbial concentration dependence of colonization of the rhizoplane niche. These data provide direct insight into the dynamics of plant root colonization in an in vivo system and define baseline parameters for the systematic identification of the bacterial genes and molecular pathways using TnSeq assays. Having determined parameters that facilitate potential colonization of roots by thousands of independent insertion mutants in a single assay, we are currently establishing a genome-wide functional map of genes required for root colonization in P.fluorescens. Importantly, the approach developed and optimized here for P.fluorescens>A.thaliana colonization will be applicable to a wide range of plant-microbe interactions, including biofuel feedstock plants and microbes known or hypothesized to impact on biofuel-relevant traits including biomass productivity

  9. Study on Interactions between the Major Apple Valsa Canker Pathogen Valsa mali and Its Biocontrol Agent Saccharothrix yanglingensis Hhs.015 Using RT-qPCR

    PubMed Central

    Fan, Dongying; Li, Yanfang; Zhao, Lingyun; Li, Zhengpeng; Huang, Lili; Yan, Xia

    2016-01-01

    The mechanism of biocontrol agent Saccharothrix yanglingensis Hhs.015 action against Valsa mali, a major apple Valsa canker pathogen, was examined using a novel, sensitive (minimum detection limit 100 pg/μL) and reliably RT-qPCR technique. Prior to lesion formation, total concentration of V. mali in the bark showed a significant decrease (p<0.05) after 24 h of Hhs.015 treatment. This was more pronounced at 48 and 96 h post treatment. After lesion formation, levels of V. mali remained constant at the boundary between infected and uninfected bark tissues, although the relative expansion rate of the lesion was significantly reduced (p<0.05). Gene expression levels of endo-polygalacturonase, a marker for fungal pathogenicity, were sharply reduced while host induced resistance callose synthase levels increased significantly (p<0.05) at the boundary bark at 9 d after Hhs.015 treatment. The results showed that biocontrol agent Hhs.015 prevented infection of V. mali by inhibiting pathogen growth, down-regulating pathogenicity factor expression and inducing a high level of host resistance. PMID:27611855

  10. Study on Interactions between the Major Apple Valsa Canker Pathogen Valsa mali and Its Biocontrol Agent Saccharothrix yanglingensis Hhs.015 Using RT-qPCR.

    PubMed

    Fan, Dongying; Li, Yanfang; Zhao, Lingyun; Li, Zhengpeng; Huang, Lili; Yan, Xia

    2016-01-01

    The mechanism of biocontrol agent Saccharothrix yanglingensis Hhs.015 action against Valsa mali, a major apple Valsa canker pathogen, was examined using a novel, sensitive (minimum detection limit 100 pg/μL) and reliably RT-qPCR technique. Prior to lesion formation, total concentration of V. mali in the bark showed a significant decrease (p<0.05) after 24 h of Hhs.015 treatment. This was more pronounced at 48 and 96 h post treatment. After lesion formation, levels of V. mali remained constant at the boundary between infected and uninfected bark tissues, although the relative expansion rate of the lesion was significantly reduced (p<0.05). Gene expression levels of endo-polygalacturonase, a marker for fungal pathogenicity, were sharply reduced while host induced resistance callose synthase levels increased significantly (p<0.05) at the boundary bark at 9 d after Hhs.015 treatment. The results showed that biocontrol agent Hhs.015 prevented infection of V. mali by inhibiting pathogen growth, down-regulating pathogenicity factor expression and inducing a high level of host resistance. PMID:27611855

  11. Bacillus velezensis RC 218 as a biocontrol agent to reduce Fusarium head blight and deoxynivalenol accumulation in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacillus velezensis RC 218 was originally isolated for the anthers of wheat as a potential antagonist of Fusarium graminearium, the causal agent of Fusarium head blight. It was demonstrated to have antagonist activity against the plant pathogen with in vitro and greenhouse assays. The current study ...

  12. Shallot aphids, Myzus ascalonicus, in strawberry: biocontrol potential of three predators and three parasitoids.

    PubMed

    Enkegaard, Annie; Sigsgaard, Lene; Kristensen, Kristian

    2013-01-01

    The parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, Myzus ascalonicus Doncaster (Homoptera: Aphididae), on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae) cv. Honeoye, were examined in laboratory experiments. In Petri dish assays, both Aphidius colemani Viereck (Hymenoptera: Aphidiidae) and A. ervi Haliday readily stung shallot aphids, with no significant difference in stinging frequency between the two species. A. ervi induced a significantly higher mortality (79.0 ± 7.2%) in terms of stung aphids compared with A. colemani (55.3 ± 4.1%); however, only a minor fraction (2.7 ± 1.8% and 7.1 ± 3.1%, respectively) of the killed aphids resulted in formation of mummies, presumably due to a physiological response to parasitism. The low percentage of mummification precludes the use of either Aphidius species in anything but inundative biocontrol. In similar set-ups, Aphelinus abdominalis (Dalman) (Hymenoptera: Aphelinidae) killed almost half (49.6 ± 5.3%) of the exposed aphids through host feeding. In addition, 23.2 ± 7.3% of non-host-fed aphids developed into mummified aphids, and 38.1 ± 13.2% of non-host-fed aphids died from other parasitoid-induced causes. However, the host feeding rate was reduced to only 1.2 ± 0.8%, and no significant parasitization mortality was observed on strawberry plants, suggesting that host plants interfered with A. abdominalis activity. This parasitoid does not, therefore, seem to be suited to either inoculative or inundative biocontrol of shallot aphids in strawberry. The three predators studied were the green lacewing, Chrysoperla carnea Steph. (Neuroptera: Chrysopidae), the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae), and the gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). Third instars of all 3 predators readily preyed upon the shallot aphid in Petri dish set-ups with significant differences in daily

  13. Shallot aphids, Myzus ascalonicus, in strawberry: biocontrol potential of three predators and three parasitoids.

    PubMed

    Enkegaard, Annie; Sigsgaard, Lene; Kristensen, Kristian

    2013-01-01

    The parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, Myzus ascalonicus Doncaster (Homoptera: Aphididae), on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae) cv. Honeoye, were examined in laboratory experiments. In Petri dish assays, both Aphidius colemani Viereck (Hymenoptera: Aphidiidae) and A. ervi Haliday readily stung shallot aphids, with no significant difference in stinging frequency between the two species. A. ervi induced a significantly higher mortality (79.0 ± 7.2%) in terms of stung aphids compared with A. colemani (55.3 ± 4.1%); however, only a minor fraction (2.7 ± 1.8% and 7.1 ± 3.1%, respectively) of the killed aphids resulted in formation of mummies, presumably due to a physiological response to parasitism. The low percentage of mummification precludes the use of either Aphidius species in anything but inundative biocontrol. In similar set-ups, Aphelinus abdominalis (Dalman) (Hymenoptera: Aphelinidae) killed almost half (49.6 ± 5.3%) of the exposed aphids through host feeding. In addition, 23.2 ± 7.3% of non-host-fed aphids developed into mummified aphids, and 38.1 ± 13.2% of non-host-fed aphids died from other parasitoid-induced causes. However, the host feeding rate was reduced to only 1.2 ± 0.8%, and no significant parasitization mortality was observed on strawberry plants, suggesting that host plants interfered with A. abdominalis activity. This parasitoid does not, therefore, seem to be suited to either inoculative or inundative biocontrol of shallot aphids in strawberry. The three predators studied were the green lacewing, Chrysoperla carnea Steph. (Neuroptera: Chrysopidae), the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae), and the gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). Third instars of all 3 predators readily preyed upon the shallot aphid in Petri dish set-ups with significant differences in daily

  14. Shallot Aphids, Myzus ascalonicus, in Strawberry: Biocontrol Potential of Three Predators and Three Parasitoids

    PubMed Central

    Enkegaard, Annie; Sigsgaard, Lene; Kristensen, Kristian

    2013-01-01

    The parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, Myzus ascalonicus Doncaster (Homoptera: Aphididae), on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae) cv. Honeoye, were examined in laboratory experiments. In Petri dish assays, both Aphidius colemani Viereck (Hymenoptera: Aphidiidae) and A. ervi Haliday readily stung shallot aphids, with no significant difference in stinging frequency between the two species. A. ervi induced a significantly higher mortality (79.0 ± 7.2%) in terms of stung aphids compared with A. colemani (55.3 ± 4.1%); however, only a minor fraction (2.7 ± 1.8% and 7.1 ± 3.1%, respectively) of the killed aphids resulted in formation of mummies, presumably due to a physiological response to parasitism. The low percentage of mummification precludes the use of either Aphidius species in anything but inundative biocontrol. In similar set-ups, Aphelinus abdominalis (Dalman) (Hymenoptera: Aphelinidae) killed almost half (49.6 ± 5.3%) of the exposed aphids through host feeding. In addition, 23.2 ± 7.3% of non-host-fed aphids developed into mummified aphids, and 38.1 ± 13.2% of non-host-fed aphids died from other parasitoid-induced causes. However, the host feeding rate was reduced to only 1.2 ± 0.8%, and no significant parasitization mortality was observed on strawberry plants, suggesting that host plants interfered with A. abdominalis activity. This parasitoid does not, therefore, seem to be suited to either inoculative or inundative biocontrol of shallot aphids in strawberry. The three predators studied were the green lacewing, Chrysoperla carnea Steph. (Neuroptera: Chrysopidae), the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae), and the gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). Third instars of all 3 predators readily preyed upon the shallot aphid in Petri dish set-ups with significant differences in daily

  15. The importance of chorismate mutase in the biocontrol potential of Trichoderma parareesei

    PubMed Central

    Pérez, Esclaudys; Rubio, M. Belén; Cardoza, Rosa E.; Gutiérrez, Santiago; Bettiol, Wagner; Monte, Enrique; Hermosa, Rosa

    2015-01-01

    Species of Trichoderma exert direct biocontrol activity against soil-borne plant pathogens due to their ability to compete for nutrients and to inhibit or kill their targets through the production of antibiotics and/or hydrolytic enzymes. In addition to these abilities, Trichoderma spp. have beneficial effects for plants, including the stimulation of defenses and the promotion of growth. Here we study the role in biocontrol of the T. parareesei Tparo7 gene, encoding a chorismate mutase (CM), a shikimate pathway branch point leading to the production of aromatic amino acids, which are not only essential components of protein synthesis but also the precursors of a wide range of secondary metabolites. We isolated T. parareesei transformants with the Tparo7 gene silenced. Compared with the wild-type, decreased levels of Tparo7 expression in the silenced transformants were accompanied by reduced CM activity, lower growth rates on different culture media, and reduced mycoparasitic behavior against the phytopathogenic fungi Rhizoctonia solani, Fusarium oxysporum and Botrytis cinerea in dual cultures. By contrast, higher amounts of the aromatic metabolites tyrosol, 2-phenylethanol and salicylic acid were detected in supernatants from the silenced transformants, which were able to inhibit the growth of F. oxysporum and B. cinerea. In in vitro plant assays, Tparo7-silenced transformants also showed a reduced capacity to colonize tomato roots. The effect of Tparo7-silencing on tomato plant responses was examined in greenhouse assays. The growth of plants colonized by the silenced transformants was reduced and the plants exhibited an increased susceptibility to B. cinerea in comparison with the responses observed for control plants. In addition, the plants turned yellowish and were defective in jasmonic acid- and ethylene-regulated signaling pathways which was seen by expression analysis of lipoxygenase 1 (LOX1), ethylene-insensitive protein 2 (EIN2) and pathogenesis

  16. The importance of chorismate mutase in the biocontrol potential of Trichoderma parareesei.

    PubMed

    Pérez, Esclaudys; Rubio, M Belén; Cardoza, Rosa E; Gutiérrez, Santiago; Bettiol, Wagner; Monte, Enrique; Hermosa, Rosa

    2015-01-01

    Species of Trichoderma exert direct biocontrol activity against soil-borne plant pathogens due to their ability to compete for nutrients and to inhibit or kill their targets through the production of antibiotics and/or hydrolytic enzymes. In addition to these abilities, Trichoderma spp. have beneficial effects for plants, including the stimulation of defenses and the promotion of growth. Here we study the role in biocontrol of the T. parareesei Tparo7 gene, encoding a chorismate mutase (CM), a shikimate pathway branch point leading to the production of aromatic amino acids, which are not only essential components of protein synthesis but also the precursors of a wide range of secondary metabolites. We isolated T. parareesei transformants with the Tparo7 gene silenced. Compared with the wild-type, decreased levels of Tparo7 expression in the silenced transformants were accompanied by reduced CM activity, lower growth rates on different culture media, and reduced mycoparasitic behavior against the phytopathogenic fungi Rhizoctonia solani, Fusarium oxysporum and Botrytis cinerea in dual cultures. By contrast, higher amounts of the aromatic metabolites tyrosol, 2-phenylethanol and salicylic acid were detected in supernatants from the silenced transformants, which were able to inhibit the growth of F. oxysporum and B. cinerea. In in vitro plant assays, Tparo7-silenced transformants also showed a reduced capacity to colonize tomato roots. The effect of Tparo7-silencing on tomato plant responses was examined in greenhouse assays. The growth of plants colonized by the silenced transformants was reduced and the plants exhibited an increased susceptibility to B. cinerea in comparison with the responses observed for control plants. In addition, the plants turned yellowish and were defective in jasmonic acid- and ethylene-regulated signaling pathways which was seen by expression analysis of lipoxygenase 1 (LOX1), ethylene-insensitive protein 2 (EIN2) and pathogenesis

  17. The importance of chorismate mutase in the biocontrol potential of Trichoderma parareesei.

    PubMed

    Pérez, Esclaudys; Rubio, M Belén; Cardoza, Rosa E; Gutiérrez, Santiago; Bettiol, Wagner; Monte, Enrique; Hermosa, Rosa

    2015-01-01

    Species of Trichoderma exert direct biocontrol activity against soil-borne plant pathogens due to their ability to compete for nutrients and to inhibit or kill their targets through the production of antibiotics and/or hydrolytic enzymes. In addition to these abilities, Trichoderma spp. have beneficial effects for plants, including the stimulation of defenses and the promotion of growth. Here we study the role in biocontrol of the T. parareesei Tparo7 gene, encoding a chorismate mutase (CM), a shikimate pathway branch point leading to the production of aromatic amino acids, which are not only essential components of protein synthesis but also the precursors of a wide range of secondary metabolites. We isolated T. parareesei transformants with the Tparo7 gene silenced. Compared with the wild-type, decreased levels of Tparo7 expression in the silenced transformants were accompanied by reduced CM activity, lower growth rates on different culture media, and reduced mycoparasitic behavior against the phytopathogenic fungi Rhizoctonia solani, Fusarium oxysporum and Botrytis cinerea in dual cultures. By contrast, higher amounts of the aromatic metabolites tyrosol, 2-phenylethanol and salicylic acid were detected in supernatants from the silenced transformants, which were able to inhibit the growth of F. oxysporum and B. cinerea. In in vitro plant assays, Tparo7-silenced transformants also showed a reduced capacity to colonize tomato roots. The effect of Tparo7-silencing on tomato plant responses was examined in greenhouse assays. The growth of plants colonized by the silenced transformants was reduced and the plants exhibited an increased susceptibility to B. cinerea in comparison with the responses observed for control plants. In addition, the plants turned yellowish and were defective in jasmonic acid- and ethylene-regulated signaling pathways which was seen by expression analysis of lipoxygenase 1 (LOX1), ethylene-insensitive protein 2 (EIN2) and pathogenesis

  18. The effect of locust bean gum (LBG)-based edible coatings carrying biocontrol yeasts against Penicillium digitatum and Penicillium italicum causal agents of postharvest decay of mandarin fruit.

    PubMed

    Parafati, Lucia; Vitale, Alessandro; Restuccia, Cristina; Cirvilleri, Gabriella

    2016-09-01

    Strains belonging to Wickerhamomyces anomalus, Metschnikowia pulcherrima and Aureobasidium pullulans species were tested in vitro as biocontrol agents (BCAs) against the post-harvest pathogenic molds Penicillium digitatum and Penicillium italicum. Moreover, studies aimed at screening the antifungal activity of selected yeast strains in vivo conditions against P. digitatum and P. italicum, and investigated the efficacy of a polysaccharidic matrix, locust bean gum (LBG), enriched with the tested BCAs, in controlling postharvest decays in artificially inoculated mandarins. The population dynamics of BCAs on wounds and the magnitude of peroxidase (POD) and superoxide dismutase (SOD) in fruit tissues were also investigated after treatments of mandarins with antagonistic yeasts. W. anomalus BS91, M. pulcherrima MPR3 and A. pullulans PI1 provided excellent control of postharvest decays caused by P. digitatum and P. italicum on mandarins, both when the yeasts were used alone and in combination with LBG, which enhanced the yeast cell viability over time. Finally, the increased activity of POD and lower decrease in SOD activity in response to BCAs application in mandarin fruits confirmed their involvement in the biocontrol mechanism.

  19. The glyoxylate cycle is involved in pleotropic phenotypes, antagonism and induction of plant defence responses in the fungal biocontrol agent Trichoderma atroviride.

    PubMed

    Dubey, Mukesh K; Broberg, Anders; Sooriyaarachchi, Sanjeewani; Ubhayasekera, Wimal; Jensen, Dan Funck; Karlsson, Magnus

    2013-01-01

    Isocitrate lyase (ICL), a signature enzyme of the glyoxylate cycle, is required for metabolism of non-fermentable carbon compounds like acetate or ethanol, and virulence in bacteria and fungi. In the present study, we investigate the role of the glyoxylate cycle in the fungal biocontrol agent Trichoderma atroviride by generating icl deletion and complementation mutants. Phenotypic analyses of the deletion mutant Δicl suggest that ICL is required for normal growth, conidial pigmentation and germination, and abiotic stress tolerance. The Δicl strain display reduced antagonism towards Botrytis cinerea in plate confrontation assays. Secretion and sandwich assays further show that secreted factors are partly responsible for the reduced antagonism. Furthermore, in vitro root colonization assays shows that the Δicl strain retains the ability to internally colonize Arabidopsis thaliana roots. However, the Δicl strain has a reduced ability to induce systemic defence in A. thaliana leaves that results in reduced protection against B. cinerea. These data shows that ICL and the glyoxylate cycle are important for biocontrol traits in T. atroviride, including direct antagonism and induction of defence responses in plants.

  20. The effect of locust bean gum (LBG)-based edible coatings carrying biocontrol yeasts against Penicillium digitatum and Penicillium italicum causal agents of postharvest decay of mandarin fruit.

    PubMed

    Parafati, Lucia; Vitale, Alessandro; Restuccia, Cristina; Cirvilleri, Gabriella

    2016-09-01

    Strains belonging to Wickerhamomyces anomalus, Metschnikowia pulcherrima and Aureobasidium pullulans species were tested in vitro as biocontrol agents (BCAs) against the post-harvest pathogenic molds Penicillium digitatum and Penicillium italicum. Moreover, studies aimed at screening the antifungal activity of selected yeast strains in vivo conditions against P. digitatum and P. italicum, and investigated the efficacy of a polysaccharidic matrix, locust bean gum (LBG), enriched with the tested BCAs, in controlling postharvest decays in artificially inoculated mandarins. The population dynamics of BCAs on wounds and the magnitude of peroxidase (POD) and superoxide dismutase (SOD) in fruit tissues were also investigated after treatments of mandarins with antagonistic yeasts. W. anomalus BS91, M. pulcherrima MPR3 and A. pullulans PI1 provided excellent control of postharvest decays caused by P. digitatum and P. italicum on mandarins, both when the yeasts were used alone and in combination with LBG, which enhanced the yeast cell viability over time. Finally, the increased activity of POD and lower decrease in SOD activity in response to BCAs application in mandarin fruits confirmed their involvement in the biocontrol mechanism. PMID:27217363

  1. Identification of an antifungal metabolite produced by a potential biocontrol Actinomyces strain A01.

    PubMed

    Lu, Cai Ge; Liu, Wei Cheng; Qiu, Ji Yan; Wang, Hui Min; Liu, Ting; De Liu, Wen

    2008-10-01

    Actinomyces strain A01 was isolated from soil of a vegetable field in the suburb of Beijing, China. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain A01 was identified as Streptomyces lydicus. In the antimicrobial spectrum test strain A01 presented a stable and strong inhibitory activity against several plant pathogenic fungi such as Fusarium oxysporum, Botrytis cinerea, Monilinia laxa, etc. However, no antibacterial activity was found. In pot experiments in greenhouse, the development of tomato gray mold was markedly suppressed by treatment with the fermentation broth of the strain A01, and the control efficacy was higher than those of Pyrimethanil and Polyoxin. A main antifungal compound (purity 99.503%) was obtained from the fermentation broth of strain A01 using column chromatography and HPLC. The chemical structural analysis with U V, IR, MS, and NMR confirmed that the compound produced by the strain A01 is natamycin, a polyene antibiotic produced by S. chattanovgensis, S. natalensis, and S. gilvosporeus, widely used as a natural biological preservative for food according to previous reports. The present study revealed a new producing strain of natamycin and its potential application as a biological control agent for fungal plant diseases.

  2. Natural enemy-mediated indirect interactions among prey species: potential for enhancing biocontrol services in agroecosystems.

    PubMed

    Chailleux, Anaïs; Mohl, Emily K; Teixeira Alves, Mickaël; Messelink, Gerben J; Desneux, Nicolas

    2014-12-01

    Understanding how arthropod pests and their natural enemies interact in complex agroecosystems is essential for pest management programmes. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent competition). From this premise, we (i) discuss the complexity of indirect interactions among pests in agroecosystems and highlight the importance of natural enemy-mediated indirect interactions other than apparent competition, (ii) outline factors that affect the nature of enemy-mediated indirect interactions in the field and (iii) identify the way to manipulate enemy-mediated interactions for biological control. We argue that there is a need to increase the link between community ecology theory and biological control to develop better agroecological methods of crop protection via conservation biological control. In conclusion, we identify (i) interventions to be chosen depending on agroecosystem characteristics and (ii) several lines of research that will improve the potential for enemy-mediated indirect interactions to be applied to biological control.

  3. Biocide effects of volatile organic compounds produced by potential biocontrol rhizobacteria on Sclerotinia sclerotiorum

    PubMed Central

    Giorgio, Annalisa; De Stradis, Angelo; Lo Cantore, Pietro; Iacobellis, Nicola S.

    2015-01-01

    Six rhizobacteria isolated from common bean and able to protect bean plants from the common bacterial blight (CBB) causal agent, were in vitro evaluated for their potential antifungal effects toward different plant pathogenic fungi, mostly soil-borne. By dual culture assays, the above bacteria resulted producing diffusible and volatile metabolites which inhibited the growth of the majority of the pathogens under study. In particular, the latter substances highly affected the mycelium growth of Sclerotinia sclerotiorum strains, one of which was selected for further studies either on mycelium or sclerotia. Gas chromatographic analysis of the bacterial volatiles led to the identification of an array of volatile organic compounds (VOCs). Time course studies showed the modification of the VOCs profile along a period of 5 days. In order to evaluate the single detected VOC effects on fungal growth, some of the pure compounds were tested on S. sclerotiorum mycelium and their minimal inhibitory quantities were determined. Similarly, the minimal inhibitory quantities on sclerotia germination were also defined. Moreover, observations by light and transmission electron microscopes highlighted hyphae cytoplasm granulation and ultrastructural alterations at cell organelles, mostly membranes, mitochondria, and endoplasmic reticulum. The membranes appeared one of the primary targets of bacterial volatiles, as confirmed by hemolytic activity observed for the majority of pure VOCs. However, of interest is the alteration observed on mitochondria as well. PMID:26500617

  4. Biocontrol potential of essential oil monoterpenes against housefly, Musca domestica (Diptera: Muscidae).

    PubMed

    Kumar, Peeyush; Mishra, Sapna; Malik, Anushree; Satya, Santosh

    2014-02-01

    Housefly (Musca domestica L.), one of the most common insects in human settlements, has been associated as vectors for various food-borne pathogens, causing food spoilage and disease transmission. The control of housefly was attempted using plant monoterpenes; menthone, menthol, menthyl acetate, limonene, citral and 1,8-cineole, against different life stages of housefly. Bioefficacy against housefly adults revealed highest repellent activity by menthol (95.6 percent) and menthone (83.3 percent). Against housefly larvae, menthol with an LC90 of 0.02 µl/cm(2) in contact toxicity assay and menthone with a LC90 value of 5.4 µl/L in fumigation assay were found to be most effective control agent. With respect to pupicidal activity, superior performance was shown by menthol, citral and 1,8-cineole in contact toxicity assay and citral and 1,8-cineole in fumigation assay. Limonene was found to be the poorest performer in all the assays. Overall, highest efficacy observed for menthol and menthone in various bioassays was in agreement with the results of essential oil activity obtained previously. Significant activity of monoterpenes against various life stages of housefly demonstrates their potential as excellent insecticides with prospects of monoterpenes being developed into eco-friendly and acceptable products for housefly control.

  5. Identification of an antifungal metabolite produced by a potential biocontrol Actinomyces strain A01

    PubMed Central

    Lu, Cai Ge; Liu, Wei Cheng; Qiu, Ji Yan; Wang, Hui Min; Liu, Ting; De Liu, Wen

    2008-01-01

    Actinomyces strain A01 was isolated from soil of a vegetable field in the suburb of Beijing, China. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain A01 was identified as Streptomyces lydicus. In the antimicrobial spectrum test strain A01 presented a stable and strong inhibitory activity against several plant pathogenic fungi such as Fusarium oxysporum, Botrytis cinerea, Monilinia laxa, etc. However, no antibacterial activity was found. In pot experiments in greenhouse, the development of tomato gray mold was markedly suppressed by treatment with the fermentation broth of the strain A01, and the control efficacy was higher than those of Pyrimethanil and Polyoxin. A main antifungal compound (purity 99.503%) was obtained from the fermentation broth of strain A01 using column chromatography and HPLC. The chemical structural analysis with U V, IR, MS, and NMR confirmed that the compound produced by the strain A01 is natamycin, a polyene antibiotic produced by S. chattanovgensis, S. natalensis, and S. gilvosporeus, widely used as a natural biological preservative for food according to previous reports. The present study revealed a new producing strain of natamycin and its potential application as a biological control agent for fungal plant diseases. PMID:24031293

  6. Biocide effects of volatile organic compounds produced by potential biocontrol rhizobacteria on Sclerotinia sclerotiorum.

    PubMed

    Giorgio, Annalisa; De Stradis, Angelo; Lo Cantore, Pietro; Iacobellis, Nicola S

    2015-01-01

    Six rhizobacteria isolated from common bean and able to protect bean plants from the common bacterial blight (CBB) causal agent, were in vitro evaluated for their potential antifungal effects toward different plant pathogenic fungi, mostly soil-borne. By dual culture assays, the above bacteria resulted producing diffusible and volatile metabolites which inhibited the growth of the majority of the pathogens under study. In particular, the latter substances highly affected the mycelium growth of Sclerotinia sclerotiorum strains, one of which was selected for further studies either on mycelium or sclerotia. Gas chromatographic analysis of the bacterial volatiles led to the identification of an array of volatile organic compounds (VOCs). Time course studies showed the modification of the VOCs profile along a period of 5 days. In order to evaluate the single detected VOC effects on fungal growth, some of the pure compounds were tested on S. sclerotiorum mycelium and their minimal inhibitory quantities were determined. Similarly, the minimal inhibitory quantities on sclerotia germination were also defined. Moreover, observations by light and transmission electron microscopes highlighted hyphae cytoplasm granulation and ultrastructural alterations at cell organelles, mostly membranes, mitochondria, and endoplasmic reticulum. The membranes appeared one of the primary targets of bacterial volatiles, as confirmed by hemolytic activity observed for the majority of pure VOCs. However, of interest is the alteration observed on mitochondria as well. PMID:26500617

  7. Characterization of ACC deaminase from the biocontrol and plant growth-promoting agent Trichoderma asperellum T203.

    PubMed

    Viterbo, Ada; Landau, Udi; Kim, Sofia; Chernin, Leonid; Chet, Ilan

    2010-04-01

    1-aminocyclopropane-1-carboxylate (ACC) deaminase activity was evaluated in the biocontrol and plant growth-promoting fungus Trichoderma asperellum T203. Fungal cultures grown with ACC as the sole nitrogen source showed high enzymatic activity. The enzyme encoding gene (Tas-acdS) was isolated, and an average 3.5-fold induction of the gene by 3 mM ACC was detected by real-time PCR. Escherichia coli bacteria carrying the intron-free cDNA of Tas-acdS cloned into the vector pAlter-EX1 under the control of the tac promoter revealed specific ACC deaminase (ACCD) activity and the ability to promote canola (Brassica napus) root elongation in pouch assays. RNAi silencing of the ACCD gene in T. asperellum showed decreased ability of the mutants to promote root elongation of canola seedlings. These data suggest a role for ACCD in the plant root growth-promotion effect by T. asperellum.

  8. Distribution and Biocontrol Potential of phlD(+) Pseudomonads in Corn and Soybean Fields.

    PubMed

    McSpadden Gardener, Brian B; Gutierrez, Laura J; Joshi, Raghavendra; Edema, Richard; Lutton, Elizabeth

    2005-06-01

    these findings to natural and augmentative biocontrol of root pathogens by these bacteria is discussed. PMID:18943789

  9. Effect of heat shock treatment on stress tolerance and biocontrol efficacy of biocontrol yeasts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several different species of yeasts have been used as biocontrol agents against postharvest diseases of fruits and vegetables. Our current research is directed to develop a better understanding of yeast biology in relation to biocontrol activity and to develop strategies to improve the efficacy of ...

  10. Screening Commercially Available Entomopathogenic Biocontrol Agents for the Control of Aethina tumida (Coleoptera: Nitidulidae) in the UK.

    PubMed

    Cuthbertson, Andrew G S; Mathers, James J; Blackburn, Lisa F; Powell, Michelle E; Marris, Gay; Pietravalle, Stephane; Brown, Mike A; Budge, Giles E

    2012-08-09

    The Small hive beetle, Aethina tumida, is an invasive pest of honey bees. Indigenous to sub-Saharan Africa, it has now become established in North America and Australia. It represents a serious threat to European honey bees. Commercially available entomopathogenic agents were screened for their potential to control beetle larvae. Entomopathogenic fungi investigated had minimal impact. The nematodes Steinernema kraussei and S. carpocapsae provided excellent control with 100% mortality of larvae being obtained. Sequential applications of the nematodes following larvae entering sand to pupate also provided excellent control for up to 3 weeks. The information gained supports the development of contingency plans to deal with A. tumida should it occur in the UK, and is relevant to the management of Small hive beetle where it is already present.

  11. Exploring ComQXPA quorum-sensing diversity and biocontrol potential of Bacillus spp. isolates from tomato rhizoplane

    PubMed Central

    Oslizlo, A; Stefanic, P; Vatovec, S; Beigot Glaser, S; Rupnik, M; Mandic-Mulec, I

    2015-01-01

    Bacillus subtilis is a widespread and diverse bacterium t exhibits a remarkable intraspecific diversity of the ComQXPA quorum-sensing (QS) system. This manifests in the existence of distinct communication groups (pherotypes) that can efficiently communicate within a group, but not between groups. Similar QS diversity was also found in other bacterial species, and its ecological and evolutionary meaning is still being explored. Here we further address the ComQXPA QS diversity among isolates from the tomato rhizoplane, a natural habitat of B. subtilis, where these bacteria likely exist in their vegetative form. Because this QS system regulates production of anti-pathogenic and biofilm-inducing substances such as surfactins, knowledge on cell–cell communication of this bacterium within rhizoplane is also important from the biocontrol perspective. We confirm the presence of pherotype diversity within B. subtilis strains isolated from a rhizoplane of a single plant. We also show that B. subtilis rhizoplane isolates show a remarkable diversity of surfactin production and potential plant growth promoting traits. Finally, we discover that effects of surfactin deletion on biofilm formation can be strain specific and unexpected in the light of current knowledge on its role it this process. PMID:25757097

  12. Exploring ComQXPA quorum-sensing diversity and biocontrol potential of Bacillus spp. isolates from tomato rhizoplane.

    PubMed

    Oslizlo, A; Stefanic, P; Vatovec, S; Beigot Glaser, S; Rupnik, M; Mandic-Mulec, I

    2015-05-01

    Bacillus subtilis is a widespread and diverse bacterium t exhibits a remarkable intraspecific diversity of the ComQXPA quorum-sensing (QS) system. This manifests in the existence of distinct communication groups (pherotypes) that can efficiently communicate within a group, but not between groups. Similar QS diversity was also found in other bacterial species, and its ecological and evolutionary meaning is still being explored. Here we further address the ComQXPA QS diversity among isolates from the tomato rhizoplane, a natural habitat of B. subtilis, where these bacteria likely exist in their vegetative form. Because this QS system regulates production of anti-pathogenic and biofilm-inducing substances such as surfactins, knowledge on cell-cell communication of this bacterium within rhizoplane is also important from the biocontrol perspective. We confirm the presence of pherotype diversity within B. subtilis strains isolated from a rhizoplane of a single plant. We also show that B. subtilis rhizoplane isolates show a remarkable diversity of surfactin production and potential plant growth promoting traits. Finally, we discover that effects of surfactin deletion on biofilm formation can be strain specific and unexpected in the light of current knowledge on its role it this process.

  13. Biocontrol of the Potato Blackleg and Soft Rot Diseases Caused by Dickeya dianthicola

    PubMed Central

    Raoul des Essarts, Yannick; Cigna, Jérémy; Quêtu-Laurent, Angélique; Caron, Aline; Munier, Euphrasie; Beury-Cirou, Amélie

    2015-01-01

    Development of protection tools targeting Dickeya species is an important issue in the potato production. Here, we present the identification and the characterization of novel biocontrol agents. Successive screenings of 10,000 bacterial isolates led us to retain 58 strains that exhibited growth inhibition properties against several Dickeya sp. and/or Pectobacterium sp. pathogens. Most of them belonged to the Pseudomonas and Bacillus genera. In vitro assays revealed a fitness decrease of the tested Dickeya sp. and Pectobacterium sp. pathogens in the presence of the biocontrol agents. In addition, four independent greenhouse assays performed to evaluate the biocontrol bacteria effect on potato plants artificially contaminated with Dickeya dianthicola revealed that a mix of three biocontrol agents, namely, Pseudomonas putida PA14H7 and Pseudomonas fluorescens PA3G8 and PA4C2, repeatedly decreased the severity of blackleg symptoms as well as the transmission of D. dianthicola to the tuber progeny. This work highlights the use of a combination of biocontrol strains as a potential strategy to limit the soft rot and blackleg diseases caused by D. dianthicola on potato plants and tubers. PMID:26497457

  14. Phages of Listeria offer novel tools for diagnostics and biocontrol

    PubMed Central

    Hagens, Steven; Loessner, Martin J.

    2014-01-01

    Historically, bacteriophages infecting their hosts have perhaps been best known and even notorious for being a nuisance in dairy-fermentation processes. However, with the rapid progress in molecular microbiology and microbial ecology, a new dawn has risen for phages. This review will provide an overview on possible uses and applications of Listeria phages, including phage-typing, reporter phage for bacterial diagnostics, and use of phage as biocontrol agents for food safety. The use of phage-encoded enzymes such as endolysins for the detection and as antimicrobial agent will also be addressed. Desirable properties of candidate phages for biocontrol will be discussed. While emphasizing the enormous future potential for applications, we will also consider some of the intrinsic limitations dictated by both phage and bacterial ecology. PMID:24782847

  15. Antagonistic activity of Bacillus subtilis SB1 and its biocontrol effect on tomato bacterial wilt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A potential biocontrol agent of bacterial wilt, Bacillus subtilis SB1, isolated from tomato roots, showed a broad-spectrum of antimicrobial activity in in vitro experiments. It inhibited the growth of many plant pathogens, including Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, Fusarium ox...

  16. Functional analysis of the class II hydrophobin gene HFB2-6 from the biocontrol agent Trichoderma asperellum ACCC30536.

    PubMed

    Huang, Ying; Mijiti, Gulijimila; Wang, Zhiying; Yu, Wenjing; Fan, Haijuan; Zhang, Rongshu; Liu, Zhihua

    2015-02-01

    A class II hydrophobin gene, HFB2-6, was cloned from Trichoderma asperellum ACCC30536 and its biocontrol function was studied. According to our previous transcriptome data, six of the eight class II hydrophobin genes were obviously differential expression in four inducing conditions, especially the gene HFB2-6. Moreover, HFB2-6 proven to be differentially transcribed under eight different treatments. HFB2-6 transcripts were up-regulated under 1% Alternaria alternata cell wall and 5% A. alternata fermentation liquid treatments, and by nutritional stress conditions, suggesting that HFB2-6 plays roles in interactions with both biotic and abiotic environmental conditions. HFB2-6 expression was down-regulated under 1% poplar leaf powder culture conditions, but its expression was up-regulated under 1% poplar root powder, indicating that HFB2-6 has a function in root colonization. Furthermore, the recombinant hydrophobin rHFB2-6 was successfully expressed in Escherichia coli BL21-HFB2-6 and purified from the recombinant strain. Genes related to both the jasmonic acid and salicylic acid signal transduction pathways were up-regulated by interaction with renatured rHFB2-6. The ORCA3 (octadecanoid-derivative responsive Catharanthus AP2-domain) gene of the poplar jasmonic acid signal transduction pathway showed a peak expression of 4.48 times at 2 h, and the peak expression of PR1 (pathogenesis-related protein gene) in the salicylic acid signal transduction pathway was 4.58 times at 72 h. Two genes, MP (monopteros) and GH3.17 (auxin original response gene), in the auxin signal transduction pathway were also up-regulated after induction with rHFB2-6, indicating that rHFB2-6 can promote poplar growth and confer broad-spectrum resistance to pathogens.

  17. Mycorrhizal fungi and Trichoderma harzianum as biocontrol agents for suppression of Rhizoctonia solani damping-off disease of tomato.

    PubMed

    Amer, M A; Abou-El-Seoud, I I

    2008-01-01

    The objective of the present work was to examine the interaction between arbuscular mycorrhizal fungus (AMF) Glomus intraradices and Trichoderma harzianum in soil. Soil application with T. harzianum or/and G. intraradices significantly reduced tomato seedlings damping-off incited by Rhizoctonia solani. Moreover, more pronounced disease suppression was obtained when both bioagents were applied together. Application of T. harzianum to healthy or inoculated seedlings significantly increased phosphorous supply, which resulted in higher yield, associated with the accumulation of high phosphorus levels in tissues of tomato plants (4.7- 6.5-fold), compared with low P supply. Inoculation with both bioagents in the presence or absence of the pathogen gave significant rise (2.1 - 2.2-fold), compared with low P levels. Root length of inoculated plants treated with T. harzianum or G. intraradices appeared longer than those of inoculated untreated plants at all P levels. Phosphorus uptake (mg P/plant) of tomato plant increased in all treatments with increasing of P levels with R. solani, T. harzianum or their combination and untreated plants have vigorous response to phosphorus fertilization. At low P levels, there was a significant difference between treatments, P uptake of tomato plants inoculated with AMF, T. harzianum or in combination, either in absence or in the presence of the tested pathogen showed highly significant increase, compared to untreated plant, infected plants with pathogen, T. harzianum, and their mixture. At high P levels, there was no significant difference between control and both AMF and T. harzianum, either individually in health plants or in combination with the pathogen. Eventually, results presented here substantiate other studies reporting enhanced biocontrol performance.

  18. Field observation on the efficacy of Toxorhynchites splendens (Wiedemann) as a biocontrol agent against Aedes albopictus (Skuse) larvae in a cemetery.

    PubMed

    Nyamah, M A; Sulaiman, S; Omar, B

    2011-08-01

    This study explored the efficacy of Toxorhynchites splendens, predator of Aedes albopictus as a biocontrol agent. There was a negative correlation between Ae. albopictus larval population and Tx. splendens larval population in ovitraps (r=-0.287, R²=0.0821). The correlation is higher between the mean number of Ae. albopictus larvae per ovitrap and the number of Tx. splendens larvae in an ovitrap (r=-0.987, R²=0.9737). Larvae of Tx. splendens were observed to co-exist with larvae of Ae. albopictus and Culex fuscocephala in the ovitraps placed in the study area. The existence of Tx. splendens larvae in the study area coincides with their habit, preferring to breed in bamboo stumps. A total of 480 ovitraps were inspected for 30-week study period and 281 ovitraps were positive with Ae. albopictus larvae respectively. There was a significant difference between numbers of ovitrap positive for Ae. albopictus larvae with number of Tx. splendens larvae in the ovitraps (ANOVA, F((4,475)) 2.655, p<0.05). Of 281 ovitraps positive with Ae. albopictus larvae, 255 ovitraps contained only one Tx. splendens larva each. Only one ovitrap contained four, the most number of Tx. splendens larvae (p< 0.05). Thus, Tx. splendens could be utilised as an alternative for dengue vector control programme. PMID:22041750

  19. The development of genetic and molecular markers to register and commercialize Penicillium rubens (formerly Penicillium oxalicum) strain 212 as a biocontrol agent.

    PubMed

    Villarino, Maria; De Cal, Antonieta; Melgarejo, Paloma; Larena, Inmaculada; Espeso, Eduardo A

    2016-01-01

    Penicillium oxalicum strain 212 (PO212) is an effective biocontrol agent (BCA) against a large number of economically important fungal plant pathogens. For successful registration as a BCA in Europe, PO212 must be accurately identified. In this report, we describe the use of classical genetic and molecular markers to characterize and identify PO212 in order to understand its ecological role in the environment or host. We successfully generated pyrimidine (pyr-) auxotrophic mutants. In addition we also designed specific oligonucleotides for the pyrF gene at their untranslated regions for rapid and reliable identification and classification of strains of P. oxalicum and P. rubens, formerly P. chrysogenum. Using these DNA-based technologies, we found that PO212 is a strain of P. rubens, and is not a strain of P. oxalicum. This work presents PO212 as the unique P. rubens strain to be described as a BCA and the information contained here serves for its registration and commercialization in Europe.

  20. Role of the methylcitrate cycle in growth, antagonism and induction of systemic defence responses in the fungal biocontrol agent Trichoderma atroviride.

    PubMed

    Dubey, Mukesh K; Broberg, Anders; Jensen, Dan Funck; Karlsson, Magnus

    2013-12-01

    Methylisocitrate lyase (MCL), a signature enzyme of the methylcitrate cycle, which cleaves methylisocitrate to pyruvate and succinate, is required for propionate metabolism, for secondary metabolite production and for virulence in bacteria and fungi. Here we investigate the role of the methylcitrate cycle by generating an mcl deletion mutant in the fungal biocontrol agent Trichoderma atroviride. Gene expression analysis shows that a basal expression of mcl is observed in all growth conditions tested. Phenotypic analysis of an mcl deletion mutant suggests the requirement of MCL in propionate resistance, growth, conidial pigmentation and germination, and abiotic stress tolerance. A plate confrontation assay did not show a difference between the WT and the Δmcl strain in antagonism towards Botrytis cinerea. However, the Δmcl strain displays reduced antagonism towards B. cinerea based on a secretion assay. Furthermore, an in vitro root colonization assay shows that the Δmcl strain had reduced ability to colonize Arabidopsis thaliana roots, which results in reduced induction of systemic resistance towards B. cinerea. These data show that MCL is important not only for growth and development in T. atroviride but also in antagonism, root colonization and induction of defence responses in plants.

  1. An alpha-glucosidase inhibitor from an endophytic Cladosporium sp. with potential as a biocontrol agent.

    PubMed

    Singh, Bahaderjeet; Kaur, Tamanreet; Kaur, Sanehdeep; Manhas, Rajesh K; Kaur, Amarjeet

    2015-02-01

    This study highlights the importance of alpha-glucosidase inhibitors as mechanisms for endophyte-mediated resistance to insect pests. One of the major benefits which endophytes confer on plants is providing resistance against insect pests. This built-in defense mechanism of the plant can be used for exploring ecofriendly strategies for pest control. In the present study, 34 endophytic fungi were isolated from Tinospora cordifolia and screened for their ability to produce alpha-glucosidase inhibitors. Maximum inhibitory activity was observed in an isolate from T. cordifolia (TN-9S), identified to be Cladosporium sp. The inhibitor was purified using chromatographic techniques. The insecticidal activity of the purified inhibitor was evaluated against Spodoptera litura. The inhibitor induced a significant mortality in the larvae of S. litura and adversely affected its survival and development. It also inhibited the activity of α-glycosidases in vivo in the gut of the larvae. The purified inhibitor was determined to be a phenolic compound with amine groups, demonstrating a noncompetitive type of inhibition in vitro. The production of the inhibitor was optimized. Response surface methodology (RSM) analysis revealed a significant interaction between dextrose and malt extract, with first-order effect of pH. PMID:25432333

  2. Potential of predatory bacteria as biocontrol agents for foodborne and plant pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne pathogens such as Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, Shigella are responsible for frequent occurrences of illnesses and mortality in humans and produce losses. Pre-harvest yield losses and post-harvest decay on minimally processed produce (fruits, vegetables...

  3. An alpha-glucosidase inhibitor from an endophytic Cladosporium sp. with potential as a biocontrol agent.

    PubMed

    Singh, Bahaderjeet; Kaur, Tamanreet; Kaur, Sanehdeep; Manhas, Rajesh K; Kaur, Amarjeet

    2015-02-01

    This study highlights the importance of alpha-glucosidase inhibitors as mechanisms for endophyte-mediated resistance to insect pests. One of the major benefits which endophytes confer on plants is providing resistance against insect pests. This built-in defense mechanism of the plant can be used for exploring ecofriendly strategies for pest control. In the present study, 34 endophytic fungi were isolated from Tinospora cordifolia and screened for their ability to produce alpha-glucosidase inhibitors. Maximum inhibitory activity was observed in an isolate from T. cordifolia (TN-9S), identified to be Cladosporium sp. The inhibitor was purified using chromatographic techniques. The insecticidal activity of the purified inhibitor was evaluated against Spodoptera litura. The inhibitor induced a significant mortality in the larvae of S. litura and adversely affected its survival and development. It also inhibited the activity of α-glycosidases in vivo in the gut of the larvae. The purified inhibitor was determined to be a phenolic compound with amine groups, demonstrating a noncompetitive type of inhibition in vitro. The production of the inhibitor was optimized. Response surface methodology (RSM) analysis revealed a significant interaction between dextrose and malt extract, with first-order effect of pH.

  4. Whole genome shotgun sequence of Bacillus amyloliquefaciens TF28, a biocontrol entophytic bacterium.

    PubMed

    Zhang, Shumei; Jiang, Wei; Li, Jing; Meng, Liqiang; Cao, Xu; Hu, Jihua; Liu, Yushuai; Chen, Jingyu; Sha, Changqing

    2016-01-01

    Bacillus amyloliquefaciens TF28 is a biocontrol endophytic bacterium that is capable of inhibition of a broad range of plant pathogenic fungi. The strain has the potential to be developed into a biocontrol agent for use in agriculture. Here we report the whole-genome shotgun sequence of the strain. The genome size of B. amyloliquefaciens TF28 is 3,987,635 bp which consists of 3754 protein-coding genes, 65 tandem repeat sequences, 47 minisatellite DNA, 2 microsatellite DNA, 63 tRNA, 7rRNA, 6 sRNA, 3 prophage and CRISPR domains. PMID:27688836

  5. Artificial diets for classical weed biocontrol agents-it's been done. The Cactoblastis cactorum story in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The South American cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) is celebrated for its role as a biological control agent for weedy Opuntia spp., but its unintentional arrival in North America represents an economic and ecological threat to native Opuntia spp. in the U. S. and ...

  6. Chitinase production by Bacillus thuringiensis and Bacillus licheniformis: their potential in antifungal biocontrol.

    PubMed

    Gomaa, Eman Zakaria

    2012-02-01

    Thirty bacterial strains were isolated from the rhizosphere of plants collected from Egypt and screened for production of chitinase enzymes. Bacillus thuringiensis NM101-19 and Bacillus licheniformis NM120-17 had the highest chitinolytic activities amongst those investigated. The production of chitinase by B. thuringiensis and B. licheniformis was optimized using colloidal chitin medium amended with 1.5% colloidal chitin, with casein as a nitrogen source, at 30°C after five days of incubation. An enhancement of chitinase production by the two species was observed by addition of sugar substances and dried fungal mats to the colloidal chitin media. The optimal conditions for chitinase activity by B. thuringiensis and B. licheniformis were at 40°C, pH 7.0 and pH 8.0, respectively. Na(+), Mg(2+), Cu(2+), and Ca(2+) caused enhancement of enzyme activities whereas they were markedly inhibited by Zn(2+), Hg(2+), and Ag(+). In vitro, B. thuringiensis and B. licheniformis chitinases had potential for cell wall lysis of many phytopathogenic fungi tested. The addition of B. thuringiensis chitinase was more effective than that of B. licheniformis in increasing the germination of soybean seeds infected with various phytopathogenic fungi.

  7. Indirect effects of biocontrol of an invasive riparian plant (Tamarix) alters habitat and reduces herpetofauna abundance

    USGS Publications Warehouse

    Bateman, H.L.; Merritt, D.M.; Glenn, E.P.; Nagler, P.L.

    2014-01-01

    The biological control agent (tamarisk leaf beetle, Diorhabda spp.) is actively being used to defoliate exotic saltcedar or tamarisk (Tamarix spp.) in riparian ecosystems in western USA. The Virgin River in Arizona and Nevada is a system where tamarisk leaf beetle populations are spreading. Saltcedar biocontrol, like other control methods, has the potential to affect non-target species. Because amphibians and reptiles respond to vegetation changes in habitat and forage in areas where beetles are active, herpetofauna are model taxa to investigate potential impacts of biocontrol defoliation. Our objectives related herpetofauna abundance to vegetation cover and indices (normalized difference vegetation index, NDVI; enhanced vegetation index, EVI) and timing of biocontrol defoliation. We captured herpetofauna and ground-dwelling arthropods in trap arrays and measured vegetation using remotely sensed images and on-the-ground measurements at 16–21 sites 2 years before (2009–2010) and 2 years following (2011–2012) biocontrol defoliation. Following defoliation, riparian stands (including stands mixed with native and exotic trees and stands of monotypic exotic saltcedar) had significantly lower NDVI and EVI values and fewer captures of marked lizards. Total captures of herpetofauna (toads, lizards, and snakes) were related to higher vegetation cover and sites with a lower proportion of saltcedar. Our results suggest that effects of biocontrol defoliation are likely to be site-specific and depend upon the proportion of native riparian trees established prior to biocontrol introduction and defoliation. The mechanisms by which habitat structure, microclimate, and ultimately vertebrate species are affected by exotic plant biocontrol riparian areas should be a focus of natural-resource managers.

  8. Suppression of the biocontrol agent trichoderma harzianum by mycelium of the arbuscular mycorrhizal fungus glomus intraradices in root-free soil

    PubMed

    Green; Larsen; Olsson; Jensen; Jakobsen

    1999-04-01

    Trichoderma harzianum is an effective biocontrol agent against several fungal soilborne plant pathogens. However, possible adverse effects of this fungus on arbuscular mycorrhizal fungi might be a drawback in its use in plant protection. The objective of the present work was to examine the interaction between Glomus intraradices and T. harzianum in soil. The use of a compartmented growth system with root-free soil compartments enabled us to study fungal interactions without the interfering effects of roots. Growth of the fungi was monitored by measuring hyphal length and population densities, while specific fatty acid signatures were used as indicators of living fungal biomass. Hyphal 33P transport and beta-glucuronidase (GUS) activity were used to monitor activity of G. intraradices and a GUS-transformed strain of T. harzianum, respectively. As growth and metabolism of T. harzianum are requirements for antagonism, the impact of wheat bran, added as an organic nutrient source for T. harzianum, was investigated. The presence of T. harzianum in root-free soil reduced root colonization by G. intraradices. The external hyphal length density of G. intraradices was reduced by the presence of T. harzianum in combination with wheat bran, but the living hyphal biomass, measured as the content of a membrane fatty acid, was not reduced. Hyphal 33P transport by G. intraradices also was not affected by T. harzianum. This suggests that T. harzianum exploited the dead mycelium but not the living biomass of G. intraradices. The presence of external mycelium of G. intraradices suppressed T. harzianum population development and GUS activity. Stimulation of the hyphal biomass of G. intraradices by organic amendment suggests that nutrient competition is a likely means of interaction. In conclusion, it seemed that growth of and phosphorus uptake by the external mycelium of G. intraradices were not affected by the antagonistic fungus T. harzianum; in contrast, T. harzianum was adversely

  9. The SRAP based molecular diversity related to antifungal and antioxidant bioactive constituents for biocontrol potentials of Trichoderma against Sclerotium rolfsii Scc.

    PubMed

    Hirpara, Darshna G; Gajera, H P; Bhimani, R D; Golakiya, B A

    2016-08-01

    The study was performed to examine 11 isolates of Trichoderma for their bio-control potentials against Sclerotium rolfsii Sacc. causing stem rot in groundnut. The antagonists Trichoderma were subjected to sequence related amplified polymorphism (SRAP) based molecular diversity analysis and compared with their hardness to S. rolfsii with respect to secretary antifungal and antioxidant profile. T. virens NBAII Tvs 12 evident highest (87.91 %) growth inhibition of test pathogen followed by T. koningii MTCC 796 (67.03 %) at 7 days after inoculation (DAI). Microscopic study confirmed biocontrol mechanism as mycoparasitism for Tvs 12 and antibiosis for MTCC 796. The growth inhibition of test pathogen was significantly negatively correlated with sclerotia formation and lipid peroxidation during antagonism due to release of secretary bioactive antioxidants by antagonists to terminate oxidative burst generated by S. rolfsii and causing inhibition of sclerotium formation. The GC-MS profile identified antifungal and antioxidant constituents hexadecane, 1,2-benzenedicarboxylic acid, mono (2-ethylhexyl) ester, 1-hexadecanesulfonyl chloride, and octadecane in potent antagonists Tvs 12; and nonacosane and octadecane in MTCC 796 along with two novel compounds 1-pentadecene and 1-heneicosyl formate for biocontrol activity. Molecular diversity of Trichoderma isolates associated with antagonistic activity was assessed by SRAP markers. The 115 primer combinations generate total 1328 amplified products of which, 1095 are shared polymorphic and 199 are unique polymorphic. The 15 SRAP combinations produced 18 bands to diagnose best antagonist Tvs 12 and 13 SRAP combinations generated 19 unique bands for identification of MTCC 796. The mycoparasitic antagonist Tvs 12 would be the best antagonist and released unique antifungal and antioxidant constituents to combat pathogen infection. The SRAP based genetic diversity indicates Tvs12 strain clustered with T. viride NBAII Tv23 and shared

  10. Therapeutic potential of chalcones as cardiovascular agents.

    PubMed

    Mahapatra, Debarshi Kar; Bharti, Sanjay Kumar

    2016-03-01

    Cardiovascular diseases are the leading cause of death affecting 17.3 million people across the globe and are estimated to affect 23.3 million people by year 2030. In recent years, about 7.3 million people died due to coronary heart disease, 9.4 million deaths due to high blood pressure and 6.2 million due to stroke, where obesity and atherosclerotic progression remain the chief pathological factors. The search for newer and better cardiovascular agents is the foremost need to manage cardiac patient population across the world. Several natural and (semi) synthetic chalcones deserve the credit of being potential candidates to inhibit various cardiovascular, hematological and anti-obesity targets like angiotensin converting enzyme (ACE), cholesteryl ester transfer protein (CETP), diacylglycerol acyltransferase (DGAT), acyl-coenzyme A: cholesterol acyltransferase (ACAT), pancreatic lipase (PL), lipoprotein lipase (LPL), calcium (Ca(2+))/potassium (K(+)) channel, COX-1, TXA2 and TXB2. In this review, a comprehensive study of chalcones, their therapeutic targets, structure activity relationships (SARs), mechanisms of actions (MOAs) have been discussed. Chemically diverse chalcone scaffolds, their derivatives including structural manipulation of both aryl rings, replacement with heteroaryl scaffold(s) and hybridization through conjugation with other pharmacologically active scaffold have been highlighted. Chalcones which showed promising activity and have a well-defined MOAs, SARs must be considered as prototype for the design and development of potential anti-hypertensive, anti-anginal, anti-arrhythmic and cardioprotective agents. With the knowledge of these molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective chalcone derivatives as potential cardiovascular agents. PMID:26876916

  11. Complete Genome Sequence of Biocontrol Strain Pseudomonas fluorescens LBUM 223

    PubMed Central

    Roquigny, Roxane; Arseneault, Tanya; Gadkar, Vijay J.; Novinscak, Amy

    2015-01-01

    Pseudomonas fluorescens LBUM 223 is a plant growth-promoting rhizobacterium (PGPR) with biocontrol activity against various plant pathogens. It produces the antimicrobial metabolite phenazine-1-carboxylic acid, which is involved in the biocontrol of Streptomyces scabies, the causal agent of common scab of potato. Here, we report the complete genome sequence of P. fluorescens LBUM 223. PMID:25953163

  12. Complete Genome Sequence of Biocontrol Strain Pseudomonas fluorescens LBUM223

    PubMed Central

    Roquigny, Roxane; Arseneault, Tanya; Gadkar, Vijay J.; Novinscak, Amy

    2015-01-01

    Pseudomonas fluorescens LBUM223 is a plant growth-promoting rhizobacterium (PGPR) with biocontrol activity against various plant pathogens. It produces the antimicrobial metabolite phenazine-1-carboxylic acid, which is involved in the biocontrol of Streptomyces scabies, the causal agent of common scab of potato. Here, we report the complete genome sequence of P. fluorescens LBUM223. PMID:25953163

  13. Rodents as potential couriers for bioterrorism agents.

    PubMed

    Lõhmus, Mare; Janse, Ingmar; van de Goot, Frank; van Rotterdam, Bart J

    2013-09-01

    Many pathogens that can cause major public health, economic, and social damage are relatively easily accessible and could be used as biological weapons. Wildlife is a natural reservoir for many potential bioterrorism agents, and, as history has shown, eliminating a pathogen that has dispersed among wild fauna can be extremely challenging. Since a number of wild rodent species live close to humans, rodents constitute a vector for pathogens to circulate among wildlife, domestic animals, and humans. This article reviews the possible consequences of a deliberate spread of rodentborne pathogens. It is relatively easy to infect wild rodents with certain pathogens or to release infected rodents, and the action would be difficult to trace. Rodents can also function as reservoirs for diseases that have been spread during a bioterrorism attack and cause recurring disease outbreaks. As rats and mice are common in both urban and rural settlements, deliberately released rodentborne infections have the capacity to spread very rapidly. The majority of pathogens that are listed as potential agents of bioterrorism by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases exploit rodents as vectors or reservoirs. In addition to zoonotic diseases, deliberately released rodentborne epizootics can have serious economic consequences for society, for example, in the area of international trade restrictions. The ability to rapidly detect introduced diseases and effectively communicate with the public in crisis situations enables a quick response and is essential for successful and cost-effective disease control.

  14. Brucella as a potential agent of bioterrorism.

    PubMed

    Doganay, Gizem D; Doganay, Mehmet

    2013-04-01

    Perception on bioterrorism has changed after the deliberate release of anthrax by the postal system in the United States of America in 2001. Potential bioterrorism agents have been reclassified based on their dissemination, expected rate of mortality, availability, stability, and ability to lead a public panic. Brucella species can be easily cultured from infected animals and human materials. Also, it can be transferred, stored and disseminated easily. An intentional contamination of food with Brucella species could pose a threat with low mortality rate. Brucella spp. is highly infectious through aerosol route, making it an attractive pathogen to be used as a potential agent for biological warfare purposes. Recently, many studies have been concentrated on appropriate sampling of Brucella spp. from environment including finding ways for its early detection and development of new decontamination procedures such as new drugs and vaccines. There are many ongoing vaccine development studies; some of which recently received patents for detection and therapy of Brucella spp. However, there is still no available vaccine for humans. In this paper, recent developments and recent patents on brucellosis are reviewed and discussed.

  15. Rodents as potential couriers for bioterrorism agents.

    PubMed

    Lõhmus, Mare; Janse, Ingmar; van de Goot, Frank; van Rotterdam, Bart J

    2013-09-01

    Many pathogens that can cause major public health, economic, and social damage are relatively easily accessible and could be used as biological weapons. Wildlife is a natural reservoir for many potential bioterrorism agents, and, as history has shown, eliminating a pathogen that has dispersed among wild fauna can be extremely challenging. Since a number of wild rodent species live close to humans, rodents constitute a vector for pathogens to circulate among wildlife, domestic animals, and humans. This article reviews the possible consequences of a deliberate spread of rodentborne pathogens. It is relatively easy to infect wild rodents with certain pathogens or to release infected rodents, and the action would be difficult to trace. Rodents can also function as reservoirs for diseases that have been spread during a bioterrorism attack and cause recurring disease outbreaks. As rats and mice are common in both urban and rural settlements, deliberately released rodentborne infections have the capacity to spread very rapidly. The majority of pathogens that are listed as potential agents of bioterrorism by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases exploit rodents as vectors or reservoirs. In addition to zoonotic diseases, deliberately released rodentborne epizootics can have serious economic consequences for society, for example, in the area of international trade restrictions. The ability to rapidly detect introduced diseases and effectively communicate with the public in crisis situations enables a quick response and is essential for successful and cost-effective disease control. PMID:23971813

  16. Q69 (an E. faecalis-Infecting Bacteriophage) As a Biocontrol Agent for Reducing Tyramine in Dairy Products

    PubMed Central

    Ladero, Victor; Gómez-Sordo, Carolina; Sánchez-Llana, Esther; del Rio, Beatriz; Redruello, Begoña; Fernández, María; Martín, M. Cruz; Alvarez, Miguel A.

    2016-01-01

    Biogenic amines (BAs) are low molecular weight nitrogenous compounds with biological activity, formed from amino acids by decarboxylation. BAs are naturally present in all living organisms playing essential roles. However, their accumulation in food through the metabolic activity of certain microorganisms constitutes a toxicological hazard. Among foods, cheeses accumulate some of the highest concentrations of BAs since they provide an ideal environment for their accumulation. Most of the methods proposed for reducing BAs in cheese, such as milk pasteurization, have not only failed to completely solve the problem, they also affect non-BA producing lactic acid bacteria, i.e., the bacteria that participate in the development of the organoleptic characteristics of cheese. Novel technologies specifically targeted against BA producers are therefore needed to control BA accumulation. Bacteriophages have been proposed as agents for specifically controlling the presence of foodborne pathogens in food. Due to its specificity, they could be used as a biotechnological tool targeted to reduce the population of BA-producing bacteria. The present work reports the isolation, from cheese, and the characterization of bacteriophage Q69, which infects specifically Enterococcus faecalis, the species mainly responsible of the accumulation of the BA tyramine in foods. Furthermore, its capacity to reduce the accumulation of tyramine in different conditions –including a model cheese- was proven. The obtained results open up the possibility of use bacteriophages to prevent BA accumulation in fermented foods. PMID:27092117

  17. Q69 (an E. faecalis-Infecting Bacteriophage) As a Biocontrol Agent for Reducing Tyramine in Dairy Products.

    PubMed

    Ladero, Victor; Gómez-Sordo, Carolina; Sánchez-Llana, Esther; Del Rio, Beatriz; Redruello, Begoña; Fernández, María; Martín, M Cruz; Alvarez, Miguel A

    2016-01-01

    Biogenic amines (BAs) are low molecular weight nitrogenous compounds with biological activity, formed from amino acids by decarboxylation. BAs are naturally present in all living organisms playing essential roles. However, their accumulation in food through the metabolic activity of certain microorganisms constitutes a toxicological hazard. Among foods, cheeses accumulate some of the highest concentrations of BAs since they provide an ideal environment for their accumulation. Most of the methods proposed for reducing BAs in cheese, such as milk pasteurization, have not only failed to completely solve the problem, they also affect non-BA producing lactic acid bacteria, i.e., the bacteria that participate in the development of the organoleptic characteristics of cheese. Novel technologies specifically targeted against BA producers are therefore needed to control BA accumulation. Bacteriophages have been proposed as agents for specifically controlling the presence of foodborne pathogens in food. Due to its specificity, they could be used as a biotechnological tool targeted to reduce the population of BA-producing bacteria. The present work reports the isolation, from cheese, and the characterization of bacteriophage Q69, which infects specifically Enterococcus faecalis, the species mainly responsible of the accumulation of the BA tyramine in foods. Furthermore, its capacity to reduce the accumulation of tyramine in different conditions -including a model cheese- was proven. The obtained results open up the possibility of use bacteriophages to prevent BA accumulation in fermented foods.

  18. Impact of a Recombinant Biocontrol Bacterium, Pseudomonas fluorescens pc78, on Microbial Community in Tomato Rhizosphere.

    PubMed

    Kong, Hyun Gi; Kim, Nam Hee; Lee, Seung Yeup; Lee, Seon-Woo

    2016-04-01

    Pseudomonas fluorescens pc78 is an effective biocontrol agent for soil-borne fungal diseases. We previously constructed a P43-gfp tagged biocontrol bacteria P. fluorescens pc78-48 to investigate bacterial traits in natural ecosystem and the environmental risk of genetically modified biocontrol bacteria in tomato rhizosphere. Fluctuation of culturable bacteria profile, microbial community structure, and potential horizontal gene transfer was investigated over time after the bacteria treatment to the tomato rhizosphere. Tagged gene transfer to other organisms such as tomato plants and bacteria cultured on various media was examined by polymerase chain reaction, using gene specific primers. Transfer of chromosomally integrated P43-gfp from pc78 to other organisms was not apparent. Population and colony types of culturable bacteria were not significantly affected by the introduction of P. fluorescens pc78 or pc78-48 into tomato rhizosphere. Additionally, terminal restriction fragment length polymorphism profiles were investigated to estimate the influence on the microbial community structure in tomato rhizosphere between non-treated and pc78-48-treated samples. Interestingly, rhizosphere soil treated with strain pc78-48 exhibited a significantly different bacterial community structure compared to that of non-treated rhizosphere soil. Our results suggest that biocontrol bacteria treatment influences microbial community in tomato rhizosphere, while the chromosomally modified biocontrol bacteria may not pose any specific environmental risk in terms of gene transfer. PMID:27147933

  19. Impact of a Recombinant Biocontrol Bacterium, Pseudomonas fluorescens pc78, on Microbial Community in Tomato Rhizosphere.

    PubMed

    Kong, Hyun Gi; Kim, Nam Hee; Lee, Seung Yeup; Lee, Seon-Woo

    2016-04-01

    Pseudomonas fluorescens pc78 is an effective biocontrol agent for soil-borne fungal diseases. We previously constructed a P43-gfp tagged biocontrol bacteria P. fluorescens pc78-48 to investigate bacterial traits in natural ecosystem and the environmental risk of genetically modified biocontrol bacteria in tomato rhizosphere. Fluctuation of culturable bacteria profile, microbial community structure, and potential horizontal gene transfer was investigated over time after the bacteria treatment to the tomato rhizosphere. Tagged gene transfer to other organisms such as tomato plants and bacteria cultured on various media was examined by polymerase chain reaction, using gene specific primers. Transfer of chromosomally integrated P43-gfp from pc78 to other organisms was not apparent. Population and colony types of culturable bacteria were not significantly affected by the introduction of P. fluorescens pc78 or pc78-48 into tomato rhizosphere. Additionally, terminal restriction fragment length polymorphism profiles were investigated to estimate the influence on the microbial community structure in tomato rhizosphere between non-treated and pc78-48-treated samples. Interestingly, rhizosphere soil treated with strain pc78-48 exhibited a significantly different bacterial community structure compared to that of non-treated rhizosphere soil. Our results suggest that biocontrol bacteria treatment influences microbial community in tomato rhizosphere, while the chromosomally modified biocontrol bacteria may not pose any specific environmental risk in terms of gene transfer.

  20. Impact of a Recombinant Biocontrol Bacterium, Pseudomonas fluorescens pc78, on Microbial Community in Tomato Rhizosphere

    PubMed Central

    Kong, Hyun Gi; Kim, Nam Hee; Lee, Seung Yeup; Lee, Seon-Woo

    2016-01-01

    Pseudomonas fluorescens pc78 is an effective biocontrol agent for soil-borne fungal diseases. We previously constructed a P43-gfp tagged biocontrol bacteria P. fluorescens pc78-48 to investigate bacterial traits in natural ecosystem and the environmental risk of genetically modified biocontrol bacteria in tomato rhizosphere. Fluctuation of culturable bacteria profile, microbial community structure, and potential horizontal gene transfer was investigated over time after the bacteria treatment to the tomato rhizosphere. Tagged gene transfer to other organisms such as tomato plants and bacteria cultured on various media was examined by polymerase chain reaction, using gene specific primers. Transfer of chromosomally integrated P43-gfp from pc78 to other organisms was not apparent. Population and colony types of culturable bacteria were not significantly affected by the introduction of P. fluorescens pc78 or pc78-48 into tomato rhizosphere. Additionally, terminal restriction fragment length polymorphism profiles were investigated to estimate the influence on the microbial community structure in tomato rhizosphere between non-treated and pc78-48-treated samples. Interestingly, rhizosphere soil treated with strain pc78-48 exhibited a significantly different bacterial community structure compared to that of non-treated rhizosphere soil. Our results suggest that biocontrol bacteria treatment influences microbial community in tomato rhizosphere, while the chromosomally modified biocontrol bacteria may not pose any specific environmental risk in terms of gene transfer. PMID:27147933

  1. Intracellular trehalose and sorbitol synergistically promoting cell viability of a biocontrol yeast Pichia anomala for aflatoxin reduction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pichia anomala WRL-076 was discovered by a visual screening bioassay for its antagonism against Aspergillus flavus. The yeast was shown to significantly inhibit aflatoxin production and the growth of A. flavus. P. anomala is a potential biocontrol agent for reduction of mycotoxin in the food chain...

  2. Therapeutic Potential of Spirooxindoles as Antiviral Agents.

    PubMed

    Ye, Na; Chen, Haiying; Wold, Eric A; Shi, Pei-Yong; Zhou, Jia

    2016-06-10

    Antiviral therapeutics with profiles of high potency, low resistance, panserotype, and low toxicity remain challenging, and obtaining such agents continues to be an active area of therapeutic development. Due to their unique three-dimensional structural features, spirooxindoles have been identified as privileged chemotypes for antiviral drug development. Among them, spiro-pyrazolopyridone oxindoles have been recently reported as potent inhibitors of dengue virus NS4B, leading to the discovery of an orally bioavailable preclinical candidate (R)-44 with excellent in vivo efficacy in a dengue viremia mouse model. This review highlights recent advances in the development of biologically active spirooxindoles for their antiviral potential, primarily focusing on the structure-activity relationships (SARs) and modes of action, as well as future directions to achieve more potent analogues toward a viable antiviral therapy. PMID:27627626

  3. TRPV1 antagonists as potential antitussive agents.

    PubMed

    McLeod, Robbie L; Correll, Craig C; Jia, Yanlin; Anthes, John C

    2008-01-01

    Cough is an important defensive pulmonary reflex that removes irritants, fluids, or foreign materials from the airways. However, when cough is exceptionally intense or when it is chronic and/or nonproductive it may require pharmacologic suppression. For many patients, antitussive therapies consist of OTC products with inconsequential efficacies. On the other hand, the prescription antitussive market is dominated by older opioid drugs such as codeine. Unfortunately, "codeine-like" drugs suppress cough at equivalent doses that also often produce significant ancillary liabilities such as GI constipation, sedation, and respiratory depression. Thus, the discovery of a novel and effective antitussive drug with an improved side effect profile relative to codeine would fulfill an unmet clinical need in the treatment of cough. Afferent pulmonary nerves are endowed with a multitude of potential receptor targets, including TRPV1, that could act to attenuate cough. The evidence linking TRPV1 to cough is convincing. TRPV1 receptors are found on sensory respiratory nerves that are important in the generation of the cough reflex. Isolated pulmonary vagal afferent nerves are responsive to TRPV1 stimulation. In vivo, TRPV1 agonists such as capsaicin elicit cough when aerosolized and delivered to the lungs. Pertinent to the debate on the potential use of TRPV1 antagonist as antitussive agents are the observations that airway afferent nerves become hypersensitive in diseased and inflamed lungs. For example, the sensitivity of capsaicin-induced cough responses following upper respiratory tract infection and in airway inflammatory diseases such as asthma and COPD is increased relative to that of control responses. Indeed, we have demonstrated that TRPV1 antagonism can attenuate antigen-induced cough in the allergic guinea pig. However, it remains to be determined if the emerging pharmacologic profile of TRPV1 antagonists will translate into a novel human antitussive drug. Current

  4. Plants' Metabolites as Potential Antiobesity Agents

    PubMed Central

    Gooda Sahib, Najla; Saari, Nazamid; Ismail, Amin; Khatib, Alfi; Mahomoodally, Fawzi; Abdul Hamid, Azizah

    2012-01-01

    Obesity and obesity-related complications are on the increase both in the developed and developing world. Since existing pharmaceuticals fail to come up with long-term solutions to address this issue, there is an ever-pressing need to find and develop new drugs and alternatives. Natural products, particularly medicinal plants, are believed to harbor potential antiobesity agents that can act through various mechanisms either by preventing weight gain or promoting weight loss amongst others. The inhibition of key lipid and carbohydrate hydrolyzing and metabolizing enzymes, disruption of adipogenesis, and modulation of its factors or appetite suppression are some of the plethora of targeted approaches to probe the antiobesity potential of medicinal plants. A new technology such as metabolomics, which deals with the study of the whole metabolome, has been identified to be a promising technique to probe the progression of diseases, elucidate their pathologies, and assess the effects of natural health products on certain pathological conditions. This has been applied to drug research, bone health, and to a limited extent to obesity research. This paper thus endeavors to give an overview of those plants, which have been reported to have antiobesity effects and highlight the potential and relevance of metabolomics in obesity research. PMID:22666121

  5. Biocontrol of Rhizoctonia solani AG-2, the causal agent of damping-off by Muscodor cinnamomi CMU-Cib 461.

    PubMed

    Suwannarach, Nakarin; Kumla, Jaturong; Bussaban, Boonsom; Lumyong, Saisamorn

    2012-11-01

    Rhizoctonia solani is a damping-off pathogen that causes significant crop loss worldwide. In this study, the potential of Muscodor cinnamomi, a new species of endophytic fungus for controlling R. solani AG-2 damping-off disease of plant seedlings by biological fumigation was investigated. In vitro tests showed that M. cinnamomi volatile compounds inhibited mycelial growth of pathogens. Among nine solid media tested, rye grain was the best grain for inoculum production. An in vivo experiment of four seedlings, bird pepper, bush bean, garden pea and tomato were conducted. The results indicated that treatment with 30 g of M. cinnamomi inoculum was the minimum dose that caused complete control of damping-off symptoms of all seedlings after one month of planting. The R. solani-infested soil showed the lowest percentage of seed germination. In addition, M. cinnamomi did not cause any disease symptoms. From the results it is clear that M. cinnamomi is effective in controlling R. solani AG-2 both in vitro and in vivo.

  6. The roles of inoculants' carbon source use in the biocontrol of potato scab disease.

    PubMed

    Sun, Pingping; Zhao, Xinbei; Shangguan, Nini; Chang, Dongwei; Ma, Qing

    2015-04-01

    Despite the application of multiple strains in the biocontrol of plant diseases, multistrain inoculation is still constrained by its inconsistency in the field. Nutrients, especially carbons, play an important role in the biocontrol processes. However, little work has been done on the systematic estimation of inoculants' carbon source use on biocontrol efficacies in vivo. In the present study, 7 nonpathogenic Streptomyces strains alone and in different combinations were inoculated as biocontrol agents against the potato scab disease, under field conditions and greenhouse treatments. The influence of the inoculants' carbon source use properties on biocontrol efficacies was investigated. The results showed that increasing the number of inoculated strains did not necessarily result in greater biocontrol efficacy in vivo. However, single strains with higher growth rates or multiple strains with less carbon source competition had positive effects on the biocontrol efficacies. These findings may shed light on optimizing the consistent biocontrol of plant disease with the consideration of inoculants' carbon source use properties. PMID:25756527

  7. Partial purification, characterization, and kinetic studies of a low-molecular-weight, alkali-tolerant chitinase enzyme from Bacillus subtilis JN032305, A potential biocontrol strain.

    PubMed

    Shivakumar, Srividya; Karmali, Anika Nayak; Ruhimbana, Charles

    2014-01-01

    A new alkalophilic low-molecular-mass chitinase of 14 kD from the potent biocontrol agent Bacillus subtilis JN032305 was partially purified and enzymology of the chitinase was studied. The enzyme showed optimal pH of 9.0 and temperature of 50°C. The enzyme was found stable during the 60-min incubation at 50 °C. The chitinase was inhibited by group specific agents like IAA, DAN, TLCK, and SDS and metal ions Mg(2+), Ca(2+), Fe(2+), Mn(2+), Ba(2+), and Hg(2+), whereas Zn(2+) did not show significant inhibitory effect against the chitinase. PMSF partially inhibited the enzyme. Substrates specificity tests indicated that the enzyme showed 75% of relative activity on glycol chitin, 58% on carboxymethylcellulose (CMC), 33% on chitin flakes, and 166% laminarin compared to that on colloidal chitin. The enzyme also hydrolyzed 4-methylumbelliferyl-N-acetyl-D-glucosaminide, indicating its chitobiase activity. The chitinase of this study has broad specificity, which could hydrolyze not only the glycosidic bond in GlcNAc-GlcNAc but also that of related carbohydrates with glycosidic linkages. The partially purified chitinase not only showed antifungal activity against Rhizoctonia solani and Colletotrichum gloeosporioides, two potent phytopathogens of chilli, but also increased the germination of chilli seeds when infected with the two potent phytopathogenic fungi. PMID:24499366

  8. Calcium channel as a potential anticancer agent.

    PubMed

    Kriazhev, L

    2009-11-01

    Anticancer treatment in modern clinical practices includes chemotherapy and radiation therapy with or without surgical interventions. Efficiency of both methods varies greatly depending on cancer types and stages. Besides, chemo- and radiotherapy are toxic and damaging that causes serious side effects. This fact prompts the search for alternative methods of antitumor therapy. It is well known that prolonged or high increase of intracellular calcium concentration inevitably leads to the cell death via apoptosis or necrosis. However, stimulation of cell calcium level by chemical agents is hardly achievable because cells have very sophisticated machinery for maintaining intracellular calcium in physiological ranges. This obstacle can be overridden, nevertheless. It was found that calcium channels in so called calcium cells in land snails are directly regulated by extracellular calcium concentration. The higher the concentration the higher the calcium intake is through the channels. Bearing in mind that extracellular/intracellular calcium concentration ratio in human beings is 10,000-12,000 fold the insertion of the channel into cancer cells would lead to fast and uncontrollable by the cells calcium intake and cell death. Proteins composing the channel may be extracted from plasma membrane of calcium cells and sequenced by mass-spectrometry or N-terminal sequencing. Either proteins or corresponding genes could be used for targeted delivery into cancer cells.

  9. Efficient synthesis of benzamide riboside, a potential anticancer agent.

    PubMed

    Bonnac, Laurent F; Gao, Guang-Yao; Chen, Liqiang; Patterson, Steven E; Jayaram, Hiremagalur N; Pankiewicz, Krzysztof W

    2007-01-01

    An efficient five step synthesis of benzamide riboside (BR) amenable for a large scale synthesis has been developed. It allows for extensive pre-clinical studies of BR as a potential anticancer agent. PMID:18066762

  10. 4-Aminoquinoline Derivatives as Potential Antileishmanial Agents.

    PubMed

    Antinarelli, Luciana M R; Dias, Rafael M P; Souza, Isabela O; Lima, Wallace P; Gameiro, Jacy; da Silva, Adilson D; Coimbra, Elaine S

    2015-10-01

    The leishmanicidal activity of a series of 4-aminoquinoline (AMQ) derivatives was assayed against Leishmania amazonensis. This activity against the intracellular parasite was found stronger than for L. amazonensis promastigotes. Neither compound was cytotoxic against macrophages. The compound AMQ-j, which exhibited a strong activity against promastigotes and amastigotes of L. amazonensis (IC50 values of 5.9 and 2.4 μg/mL, respectively) and similar leishmanicidal activity to reference drugs, was chosen for studies regarding its possible mechanism of action toward parasite death. The results showed that the compound AMQ-j induced depolarization of the mitochondrial membrane potential in promastigotes and in L. amazonensis-infected macrophages, but not in uninfected macrophages. Furthermore, the depolarization of the mitochondrial membrane potential was dose dependent in infected macrophages. We have established that promastigotes and L. amazonensis-infected macrophages treated with AMQ-j were submitted to oxidative stress. This is in line with the increase in the level of reactive oxygen species (ROS). Leishmania amazonensis-infected macrophages treated with AMQ-j did not show a significant increase in the production of nitric oxide. Our results indicate the effective and selective action of AMQ-j against L. amazonensis, and its mechanism of action appears to be mediated by mitochondrial dysfunction associated with ROS production. PMID:25682728

  11. Quinol derivatives as potential trypanocidal agents

    PubMed Central

    Capes, Amy; Patterson, Stephen; Wyllie, Susan; Hallyburton, Irene; Collie, Iain T.; McCarroll, Andrew J.; Stevens, Malcolm F.G.; Frearson, Julie A.; Wyatt, Paul G.; Fairlamb, Alan H.; Gilbert, Ian H.

    2012-01-01

    Quinols have been developed as a class of potential anti-cancer compounds. They are thought to act as double Michael acceptors, forming two covalent bonds to their target protein(s). Quinols have also been shown to have activity against the parasite Trypanosoma brucei, the causative organism of human African trypanosomiasis, but they demonstrated little selectivity over mammalian MRC5 cells in a counter-screen. In this paper, we report screening of further examples of quinols against T. brucei. We were able to derive an SAR, but the compounds demonstrated little selectivity over MRC5 cells. In an approach to increase selectivity, we attached melamine and benzamidine motifs to the quinols, because these moieties are known to be selectively concentrated in the parasite by transporter proteins. In general these transporter motif-containing analogues showed increased selectivity; however they also showed reduced levels of potency against T. brucei. PMID:22264753

  12. Rhizoma Coptidis: A Potential Cardiovascular Protective Agent

    PubMed Central

    Tan, Hui-Li; Chan, Kok-Gan; Pusparajah, Priyia; Duangjai, Acharaporn; Saokaew, Surasak; Mehmood Khan, Tahir; Lee, Learn-Han; Goh, Bey-Hing

    2016-01-01

    Cardiovascular diseases (CVDs) are among the leading causes of morbidity and mortality in both the developed and developing world. Rhizoma coptidis (RC), known as Huang Lian in China, is the dried rhizome of medicinal plants from the family Ranunculaceae, such as Coptis chinensis Franch, C. deltoidea C.Y. Cheng et Hsiao, and C. teeta Wall which has been used by Chinese medicinal physicians for more than 2000 years. In China, RC is a common component in traditional medicines used to treat CVD associated problems including obesity, diabetes mellitus, hyperlipidemia, hyperglycemia and disorders of lipid metabolism. In recent years, numerous scientific studies have sought to investigate the biological properties of RC to provide scientific evidence for its traditional medical uses. RC has been found to exert significant beneficial effects on major risk factors for CVDs including anti-atherosclerotic effect, lipid-lowering effect, anti-obesity effect and anti-hepatic steatosis effect. It also has myocardioprotective effect as it provides protection from myocardial ischemia-reperfusion injury. These properties have been attributed to the presence of bioactive compounds contained in RC such as berberine, coptisine, palmatine, epiberberine, jatrorrhizine, and magnoflorine; all of which have been demonstrated to have cardioprotective effects on the various parameters contributing to the occurrence of CVD through a variety of pathways. The evidence available in the published literature indicates that RC is a herb with tremendous potential to reduce the risks of CVDs, and this review aims to summarize the cardioprotective properties of RC with reference to the published literature which overall indicates that RC is a herb with remarkable potential to reduce the risks and damage caused by CVDs. PMID:27774066

  13. Biocontrol Ability and Action Mechanism of Starmerella bacillaris (Synonym Candida zemplinina) Isolated from Wine Musts against Gray Mold Disease Agent Botrytis cinerea on Grape and Their Effects on Alcoholic Fermentation

    PubMed Central

    Lemos Junior, Wilson José Fernandes; Bovo, Barbara; Nadai, Chiara; Crosato, Giulia; Carlot, Milena; Favaron, Francesco; Giacomini, Alessio; Corich, Viviana

    2016-01-01

    Gray mold is one of the most important diseases of grapevine in temperate climates. This plant pathogen affects plant growth and reduces wine quality. The use of yeasts as biocontrol agents to apply in the vineyard have been investigated in recent years as an alternative to agrochemicals. In this work, fermenting musts obtained from overripe grape berries, therefore more susceptible to infection by fungal pathogens such as Botrytis cinerea, were considered for the selection of yeasts carrying antifungal activity. Thirty-six isolates were identified as Starmerella bacillaris, a species recently proven to be of enological interest. Among them 14 different strains were studied and antifungal activity against B. cinerea was demonstrated, for the first time, to be present in S. bacillaris species. The production of volatile organic compounds (VOCs), tested in vitro, was found to be the main responsible of S. bacillaris antifungal effects. All the strains were able to reduce B. cinerea decay on wounded grape berries artificially inoculated with gray mold. The colonization level of wound was very high reaching, after 5 days, a concentration of 106 cells per ml of grape juice obtained after berry crushing. At this cell concentration S. bacillaris strains were used to ferment synthetic and natural musts. The sequential yeast inoculation, performed by adding S. cerevisiae 48 h after S. bacillaris, was needed to complete sugar consumption and determined a significant increase in glicerol content and a reduction of ethanol and acetic acid concentrations. The high wound colonization ability, found in this work, together with the propensity to colonize grape berry and the interesting enological traits possessed by the selected S. bacillaris strains allow the use of this yeast as biocontrol agent on vine and grape berries with possible positive effects on must fermentation, although the presence of S. cerevisiae is needed to complete the fermentation process. This work introduces

  14. Biocontrol Ability and Action Mechanism of Starmerella bacillaris (Synonym Candida zemplinina) Isolated from Wine Musts against Gray Mold Disease Agent Botrytis cinerea on Grape and Their Effects on Alcoholic Fermentation.

    PubMed

    Lemos, Wilson J; Bovo, Barbara; Nadai, Chiara; Crosato, Giulia; Carlot, Milena; Favaron, Francesco; Giacomini, Alessio; Corich, Viviana

    2016-01-01

    Gray mold is one of the most important diseases of grapevine in temperate climates. This plant pathogen affects plant growth and reduces wine quality. The use of yeasts as biocontrol agents to apply in the vineyard have been investigated in recent years as an alternative to agrochemicals. In this work, fermenting musts obtained from overripe grape berries, therefore more susceptible to infection by fungal pathogens such as Botrytis cinerea, were considered for the selection of yeasts carrying antifungal activity. Thirty-six isolates were identified as Starmerella bacillaris, a species recently proven to be of enological interest. Among them 14 different strains were studied and antifungal activity against B. cinerea was demonstrated, for the first time, to be present in S. bacillaris species. The production of volatile organic compounds (VOCs), tested in vitro, was found to be the main responsible of S. bacillaris antifungal effects. All the strains were able to reduce B. cinerea decay on wounded grape berries artificially inoculated with gray mold. The colonization level of wound was very high reaching, after 5 days, a concentration of 10(6) cells per ml of grape juice obtained after berry crushing. At this cell concentration S. bacillaris strains were used to ferment synthetic and natural musts. The sequential yeast inoculation, performed by adding S. cerevisiae 48 h after S. bacillaris, was needed to complete sugar consumption and determined a significant increase in glicerol content and a reduction of ethanol and acetic acid concentrations. The high wound colonization ability, found in this work, together with the propensity to colonize grape berry and the interesting enological traits possessed by the selected S. bacillaris strains allow the use of this yeast as biocontrol agent on vine and grape berries with possible positive effects on must fermentation, although the presence of S. cerevisiae is needed to complete the fermentation process. This work

  15. Secretome of the Biocontrol Agent Metarhizium anisopliae Induced by the Cuticle of the Cotton Pest Dysdercus peruvianus Reveals New Insights into Infection

    PubMed Central

    2015-01-01

    Metarhizium anisopliae is an entomopathogenic fungus that has evolved specialized strategies to infect insect hosts. Here we analyzed secreted proteins related to Dysdercus peruvianus infection. Using shotgun proteomics, abundance changes in 71 proteins were identified after exposure to host cuticle. Among these proteins were classical fungal effectors secreted by pathogens to degrade physical barriers and alter host physiology. These include lipolytic enzymes, Pr1A, B, C, I, and J proteases, ROS-related proteins, oxidorreductases, and signaling proteins. Protein interaction networks were generated postulating interesting candidates for further studies, including Pr1C, based on possible functional interactions. On the basis of these results, we propose that M. anisopliae is degrading host components and actively secreting proteins to manage the physiology of the host. Interestingly, the secretion of these factors occurs in the absence of a host response. The findings presented here are an important step in understanding the host–pathogen interaction and developing more efficient biocontrol of D. peruvianus by M. anisopliae. PMID:24702058

  16. Bacillus velezensis RC 218 as a biocontrol agent to reduce Fusarium head blight and deoxynivalenol accumulation: Genome sequencing and secondary metabolite cluster profiles.

    PubMed

    Palazzini, Juan M; Dunlap, Christopher A; Bowman, Michael J; Chulze, Sofía N

    2016-11-01

    Bacillus subtilis RC 218 was originally isolated from wheat anthers as a potential antagonist of Fusarium graminearum, the causal agent of Fusarium head blight (FHB). It was demonstrated to have antagonist activity against the plant pathogen under in vitro and greenhouse assays. The current study extends characterizing B. subtilis RC 218 with a field study and genome sequencing. The field study demonstrated that B. subtilis RC 218 could reduce disease severity and the associated mycotoxin (deoxynivalenol) accumulation, under field conditions. The genome sequencing allowed us to accurately determine the taxonomy of the strain using a phylogenomic approach, which places it in the Bacillus velezensis clade. In addition, the draft genome allowed us to use bioinformatics to mine the genome for potential metabolites. The genome mining allowed us to identify 9 active secondary metabolites conserved by all B. velezensis strains and one additional secondary metabolite, the lantibiotic ericin, which is unique to this strain. This study represents the first confirmed production of ericin by a B. velezensis strain. The genome also allowed us to do a comparative genomics with its closest relatives and compare the secondary metabolite production of the publically available B. velezensis genomes. The results showed that the diversity in secondary metabolites of strains in the B. velezensis clade is driven by strains making different antibacterials. PMID:27664721

  17. Bacillus velezensis RC 218 as a biocontrol agent to reduce Fusarium head blight and deoxynivalenol accumulation: Genome sequencing and secondary metabolite cluster profiles.

    PubMed

    Palazzini, Juan M; Dunlap, Christopher A; Bowman, Michael J; Chulze, Sofía N

    2016-11-01

    Bacillus subtilis RC 218 was originally isolated from wheat anthers as a potential antagonist of Fusarium graminearum, the causal agent of Fusarium head blight (FHB). It was demonstrated to have antagonist activity against the plant pathogen under in vitro and greenhouse assays. The current study extends characterizing B. subtilis RC 218 with a field study and genome sequencing. The field study demonstrated that B. subtilis RC 218 could reduce disease severity and the associated mycotoxin (deoxynivalenol) accumulation, under field conditions. The genome sequencing allowed us to accurately determine the taxonomy of the strain using a phylogenomic approach, which places it in the Bacillus velezensis clade. In addition, the draft genome allowed us to use bioinformatics to mine the genome for potential metabolites. The genome mining allowed us to identify 9 active secondary metabolites conserved by all B. velezensis strains and one additional secondary metabolite, the lantibiotic ericin, which is unique to this strain. This study represents the first confirmed production of ericin by a B. velezensis strain. The genome also allowed us to do a comparative genomics with its closest relatives and compare the secondary metabolite production of the publically available B. velezensis genomes. The results showed that the diversity in secondary metabolites of strains in the B. velezensis clade is driven by strains making different antibacterials.

  18. [Bioterrorism, parasites as potential bioterrorism agents and biosecurity studies].

    PubMed

    Aksoy, Umit

    2006-01-01

    A variety of agents have a potential risk for being use as weapons of biological terrorism. However, the use of parasites as bioterrorism agents has not received so much attention. Parasites could contribute to the installation of fear in human population upon intentional addition to their food and water supplies. On the other hand, vector-borne parasites can also constitute risk of bioterrorism. Biosecurity issues are gaining importance as a consequence of globalization. Surveillance is critical in maintaining biosecurity and early detection of infectious disease agents is essential. In this review article, bioterrorism, the role of parasites as potential bioterrorism agents, studies on biosecurity and laboratory design for biosafety have been discussed under the light of recent literature.

  19. The relationship of biofilm production to biocontrol activity of Burkholderia pyrrocinia FP62

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar biocontrol agent (BCA) efficacy is often inconsistent due to poor colonization and survival on plant surfaces. Burkholderia pyrrocinia FP62, a superior leaf colonist and BCA of Botrytis cinerea, forms unsaturated biofilms on plant surfaces. To determine the relationship between biocontrol act...

  20. Gadolinium oxide nanoparticles as potential multimodal imaging and therapeutic agents.

    PubMed

    Kim, Tae Jeong; Chae, Kwon Seok; Chang, Yongmin; Lee, Gang Ho

    2013-01-01

    Potentials of hydrophilic and biocompatible ligand coated gadolinium oxide nanoparticles as multimodal imaging agents, drug carriers, and therapeutic agents are reviewed. First of all, they can be used as advanced T1 magnetic resonance imaging (MRI) contrast agents because they have r1 larger than those of Gd(III)-chelates due to a high density of Gd(III) per nanoparticle. They can be further functionalized by conjugating other imaging agents such as fluorescent imaging (FI), X-ray computed tomography (CT), positron emission tomography (PET), and single photon emission tomography (SPECT) agents. They can be also useful for drug carriers through morphology modifications. They themselves are also potential CT and ultrasound imaging (USI) contrast and thermal neutron capture therapeutic (NCT) agents, which are superior to commercial iodine compounds, air-filled albumin microspheres, and boron ((10)B) compounds, respectively. They, when conjugated with targeting agents such as antibodies and peptides, will provide enhanced images and be also very useful for diagnosis and therapy of diseases (so called theragnosis).

  1. Lepidopterans as potential agents for the biological control of the invasive plant, Miconia calvescens.

    PubMed

    Morais, Elisangela G F; Picanço, Marcelo C; Semeão, Altair A; Barreto, Robert W; Rosado, Jander F; Martins, Julio C

    2012-01-01

    This work investigated eight species of Lepidoptera associated with Miconia calvescens DC. (Myrtales: Melastomataceae) in Brazil, including six defoliators, Salbia lotanalis Druce (Lepidoptera: Pyralidae), Druentia inscita Schaus (Mimallonidae), Antiblemma leucocyma Hampson (Noctuidae), three Limacodidae species, a fruit borer Carposina cardinata Meyrick (Carposinidae), and a damager of flowers Pleuroprucha rudimentaria Guenée (Geometridae). Based on host specificity and the damage caused to plants, S. lotanalis and D. inscita are the most promising species for biological control of M. calvescens. Furthermore, if C. cardinata and P. rudimentaria have host specificity in future tests, these caterpillars could also be considered as appropriate biocontrol agents.

  2. Lepidopterans as Potential Agents for the Biological Control of the Invasive Plant, Miconia calvescens

    PubMed Central

    Morais, Elisangela G.F.; Picanço, Marcelo C.; Semeão, Altair A.; Barreto, Robert W.; Rosado, Jander F.; Martins, Julio C.

    2012-01-01

    This work investigated eight species of Lepidoptera associated with Miconia calvescens DC. (Myrtales: Melastomataceae) in Brazil, including six defoliators, Salbia lotanalis Druce (Lepidoptera: Pyralidae), Druentia inscita Schaus (Mimallonidae), Antiblemma leucocyma Hampson (Noctuidae), three Limacodidae species, a fruit borer Carposina cardinata Meyrick (Carposinidae), and a damager of flowers Pleuroprucha rudimentaria Guenée (Geometridae). Based on host specificity and the damage caused to plants, S. lotanalis and D. inscita are the most promising species for biological control of M. calvescens. Furthermore, if C. cardinata and P. rudimentaria have host specificity in future tests, these caterpillars could also be considered as appropriate biocontrol agents. PMID:22938203

  3. Lepidopterans as potential agents for the biological control of the invasive plant, Miconia calvescens.

    PubMed

    Morais, Elisangela G F; Picanço, Marcelo C; Semeão, Altair A; Barreto, Robert W; Rosado, Jander F; Martins, Julio C

    2012-01-01

    This work investigated eight species of Lepidoptera associated with Miconia calvescens DC. (Myrtales: Melastomataceae) in Brazil, including six defoliators, Salbia lotanalis Druce (Lepidoptera: Pyralidae), Druentia inscita Schaus (Mimallonidae), Antiblemma leucocyma Hampson (Noctuidae), three Limacodidae species, a fruit borer Carposina cardinata Meyrick (Carposinidae), and a damager of flowers Pleuroprucha rudimentaria Guenée (Geometridae). Based on host specificity and the damage caused to plants, S. lotanalis and D. inscita are the most promising species for biological control of M. calvescens. Furthermore, if C. cardinata and P. rudimentaria have host specificity in future tests, these caterpillars could also be considered as appropriate biocontrol agents. PMID:22938203

  4. Marine isolates of Trichoderma spp. as potential halotolerant agents of biological control for arid-zone agriculture.

    PubMed

    Gal-Hemed, Inbal; Atanasova, Lea; Komon-Zelazowska, Monika; Druzhinina, Irina S; Viterbo, Ada; Yarden, Oded

    2011-08-01

    The scarcity of fresh water in the Mediterranean region necessitates the search for halotolerant agents of biological control of plant diseases that can be applied in arid-zone agriculture irrigated with saline water. Among 29 Trichoderma strains previously isolated from Mediterranean Psammocinia sp. sponges, the greatest number of isolates belong to the Trichoderma longibrachiatum-Hypocrea orientalis species pair (9), H. atroviridis/T. atroviride (9), and T. harzianum species complex (7), all of which are known for high mycoparasitic potential. In addition, one isolate of T. asperelloides and two putative new species, Trichoderma sp. O.Y. 14707 and O.Y. 2407, from Longibrachiatum and Strictipilosa clades, respectively, have been identified. In vitro salinity assays showed that the ability to tolerate increasing osmotic pressure (halotolerance) is a strain- or clade-specific property rather than a feature of a species. Only a few isolates were found to be sensitive to increased salinity, while others either were halotolerant or even demonstrated improved growth in increasingly saline conditions. In vitro antibiosis assays revealed strong antagonistic activity toward phytopathogens due to the production of both soluble and volatile metabolites. Two marine-derived Trichoderma isolates, identified as T. atroviride and T. asperelloides, respectively, effectively reduced Rhizoctonia solani damping-off disease on beans and also induced defense responses in cucumber seedlings against Pseudomonas syringae pv. lachrimans. This is the first inclusive evaluation of marine fungi as potential biocontrol agents.

  5. Marine Isolates of Trichoderma spp. as Potential Halotolerant Agents of Biological Control for Arid-Zone Agriculture ▿ †

    PubMed Central

    Gal-Hemed, Inbal; Atanasova, Lea; Komon-Zelazowska, Monika; Druzhinina, Irina S.; Viterbo, Ada; Yarden, Oded

    2011-01-01

    The scarcity of fresh water in the Mediterranean region necessitates the search for halotolerant agents of biological control of plant diseases that can be applied in arid-zone agriculture irrigated with saline water. Among 29 Trichoderma strains previously isolated from Mediterranean Psammocinia sp. sponges, the greatest number of isolates belong to the Trichoderma longibrachiatum-Hypocrea orientalis species pair (9), H. atroviridis/T. atroviride (9), and T. harzianum species complex (7), all of which are known for high mycoparasitic potential. In addition, one isolate of T. asperelloides and two putative new species, Trichoderma sp. O.Y. 14707 and O.Y. 2407, from Longibrachiatum and Strictipilosa clades, respectively, have been identified. In vitro salinity assays showed that the ability to tolerate increasing osmotic pressure (halotolerance) is a strain- or clade-specific property rather than a feature of a species. Only a few isolates were found to be sensitive to increased salinity, while others either were halotolerant or even demonstrated improved growth in increasingly saline conditions. In vitro antibiosis assays revealed strong antagonistic activity toward phytopathogens due to the production of both soluble and volatile metabolites. Two marine-derived Trichoderma isolates, identified as T. atroviride and T. asperelloides, respectively, effectively reduced Rhizoctonia solani damping-off disease on beans and also induced defense responses in cucumber seedlings against Pseudomonas syringae pv. lachrimans. This is the first inclusive evaluation of marine fungi as potential biocontrol agents. PMID:21666030

  6. Appraisal of selected osmoprotectants and carriers for formulating Gram-negative biocontrol agents active against Fusarium dry rot on potatoes in storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The production of a dry formulation containing a high titer of viable cells of a Gram-negative biological control agent is a challenging and critically important step in developing the agent into a commercial product. Producing a dry formulation using methods based on air-drying is especially attrac...

  7. A new species of Dichrorampha (Lepidoptera: Tortricidae) from Jamaica: A potential biocontrol agent against Chromolaena odorata (Asterasceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dichrorampha odorata Brown and Zachariades, new species, is described and illustrated from Jamaica. It is most similar to D. sapodilla Heppner among described species, both superficially and in the male genitalia. However, the two are easily separated by the long costal fold of the male forewing of ...

  8. Corynespora cassiicola f. sp. schinii, a potential biocontrol agent for the weed Schinus terebinthifolius in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An isolate of Corynespora cassiicola was found in Brazil (state of Espírito Santo) causing a severe leaf spot and foliage blight on Schinus terebinthifolius (Anacardiaceae, Brazilian peppertree or ‘aroeira’) which is a major environmental weed in many tropical and sub-tropical areas of the globe, in...

  9. Characterization of streptomyces lydicus WYEC108 as a potential biocontrol agent against fungal root and seed rots.

    PubMed Central

    Yuan, W M; Crawford, D L

    1995-01-01

    The actinomycete Streptomyces lydicus WYEC108 showed strong in vitro antagonism against various fungal plant pathogens in plate assays by producing extracellular antifungal metabolites. When Pythium ultimum or Rhizoctonia solani was grown in liquid medium with S. lydicus WYEC108, inhibition of growth of the fungi was observed. When WYEC108 spores or mycelia were used to coat pea seeds, the seeds were protected from invasion by P. ultimum in an oospore-enriched soil. While 100% of uncoated control seeds were infected by P. ultimum within 48 h after planting, less than 40% of coated seeds were infected. When the coated seeds were planted in soil 24 h prior to introduction of the pathogen, 96 h later, less than 30% of the germinating seeds were infected. Plant growth chamber studies were also carried out to test for plant growth effects and for suppression by S. lydicus WYEC108 of Pythium seed rot and root rot. When WYEC108 was applied as a spore-peat moss-sand formulation (10(8) CFU/g) to P. ultimum-infested sterile or nonsterile soil planted with pea and cotton seeds, significant increases in average plant stand, plant length, and plant weight were observed in both cases compared with untreated control plants grown in similar soils. WYEC108 hyphae colonized and were able to migrate downward with the root as it elongated. Over a period of 30 days, the population of WYEC108 colonized emerging roots of germinating seeds and remained stable (10(5) CFU/g) in the rhizosphere, whereas the nonrhizosphere population of WYEC108 declined at least 100-fold (from 10(5) to 10(3) or fewer CFU/g). The stability of the WYEC108 population incubated at 25 degrees C in the formulation, in sterile soil, and in nonsterile soil was also evaluated. In all three environments, the population of WYEC108 maintained its size for 90 days or more. When pea, cotton, and sweet corn seeds were placed into sterile and nonsterile soils containing 10(6) or more CFU of WYEC108 per g, it colonized the emerging roots. After a 1-week growing period, WYEC108 populations of 10(5) CFU/g (wet weight) of root were found on pea roots in the amended sterile soil environment versus 10(4) CFU/g in amended nonsterile soil. To further study the in vitro interaction between the streptomycete and P. ultimum, mycelia of WYEC108 were mixed with oospores of P. ultimum in agar, which was then used as a film to coat slide coverslips.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7487043

  10. Stimulative effect of the fungal biocontrol agent Fusarium oxysporum f.sp. Striga on abundance of nitrifying prokaryotes in a maize rhizosphere

    NASA Astrophysics Data System (ADS)

    Musyoki, Mary; Enowashu, Esther; Zimmermann, Judith; Muema, Esther; Wainright, Henry; Vanlauwe, Bernard; Cadisch, Georg; Rasche, Frank

    2014-05-01

    The integration of resistant crop varieties and Fusarium oxysporum f.sp. strigae (Foxy-2) strains as biological control agent (BCA) has shown to be an effective control of the weed Striga hermonthica which is parasitic to several cereals (e.g., maize) cultivated in Sub-Saharan Africa. Most studies have examined the efficacy of the BCA and its interactions with host crops, while overlooking the interplay among key microorganisms in the soil nitrogen (N) cycle. Hence, we postulated that both Foxy-2 and Striga pose threats to the indigenous plant root-associated microbial communities involved in N cycling through direct or indirect competition for nutrients and that the application of high quality organic residues would compensate these effects. The primary objective of this study was thus to assess the potential impact of Foxy-2 on indigenous nitrifying prokaryotes in maize rhizosphere cultivated on two distinct soils (sandy Ferric Alisol versus clayey Humic Nitisol) obtained from Machanga and Embu, respectively, in central Kenya. These soils were treated with or without Foxy-2 and Striga; and in combination with high quality (i.e. CN ratio; 13, lignins, 8.9 % and polyphenols, 1.7 %) organic residues (i.e., Tithonia diversifolia) as N source. Using quantitative polymerase chain reaction (qPCR), we followed at three pre-defined sampling dates (14, 28 and 42 days after planting) the responses of ammonia-oxidizing archaea (AOA) and bacteria (AOB), total bacteria and archaea in four treatments of a rhizobox experiment: (i) Foxy-2 plus Striga (F+S), (ii) Striga only (C+S), (iii) Foxy-2 plus Striga plus Tithonia diversifolia residues (F+S+T), and (iv) a non-treated control (C). Overall, the treatment effects on soil microbial populations were, in comparison to the clayey Embu soil, more pronounced in the sandy Machanga soil. Contrary to our expectations, we observed a distinct stimulative, but no resource competition effect of Foxy-2 on the abundance of AOA, as well as

  11. Primary screen for potential sheep scab control agents.

    PubMed

    Dunn, J A; Prickett, J C; Collins, D A; Weaver, R J

    2016-07-15

    The efficacy of potential acaricidal agents were assessed against the sheep scab mite Psoroptes ovis using a series of in vitro assays in modified test arenas designed initially to maintain P. ovis off-host. The mortality effects of 45 control agents, including essential oils, detergents, desiccants, growth regulators, lipid synthesis inhibitors, nerve action/energy metabolism disruptors and ecdysteroids were assessed against adults and nymphs. The most effective candidates were the desiccants (diatomaceous earth, nanoclay and sorex), the growth regulators (buprofezin, hexythiazox and teflubenzuron), the lipid synthesis inhibitors (spirodiclofen, spirotetramat and spiromesifen) and the nerve action and energy metabolism inhibitors (fenpyroximate, spinosad, tolfenpyrad, and chlorantraniliprole). PMID:27270393

  12. Interregional comparison of the size-structure of populations of Melaleuca quinquenervia in its native and exotic range, with and without biocontrol agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We compare size structure and rates of recruitment and mortality in populations of Melaleuca quinquenervia in its native and exotic ranges. In the exotic range study sites were chosen to include contrasts in presence and abundance of two biological control agents. We tagged and measured (DBH) all ...

  13. Ceratapion basicorne (Illiger) (Coleoptera: Curculionidae): laboratory and open field trials to assess its specificity as biocontrol agent of Centaurea solstitialis (Asteraceae: Cardueae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prospective biological control agents generally must be demonstrated to not pose risks to non-target plants. Laboratory experiments evaluating host plant specificity are the most common method of evaluating such risk; however, they are constrained by limitations of space and number of replicates, gi...

  14. Polysaccharide benefits dry storage survival of the biocontrol agent Pseudomonas fluorescens S11:P:12 effective against several maladies of stored potatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas fluorescens S11:P:12 (NRRL B-21133) is a biological control agent able to suppress several storage maladies of potatoes including sprouting, Fusarium dry rot incited by Gibberella pulicaris, pink rot incited by Phytophthora erythroseptica, and late blight incited by Phytophthora infestan...

  15. Chalcone derivatives as potential antifungal agents: Synthesis, and antifungal activity

    PubMed Central

    Gupta, Deepa; Jain, D. K.

    2015-01-01

    Much research has been carried out with the aim to discover the therapeutic values of chalcone derivatives. Chalcones possess wide range of pharmacological activity such as antibacterial, antimalarial, antiprotozoal, antitubercular, anticancer, and antifungal agents etc. The presence of reactive α,β-unsaturated keto group in chalcones is found to be responsible for their biological activity. The rapid developments of resistance to antifungal agents, led to design, and synthesize the new antifungal agents. The derivatives of chalcones were prepared using Claisen–Schmidt condensation scheme with appropriate tetralone and aldehyde derivatives. Ten derivatives were synthesized and were biologically screened for antifungal activity. The newly synthesized derivatives of chalcone showed antifungal activity against fungal species, Microsporum gypseum. The results so obtained were superior or comparable to ketoconazole. It was observed that none of the compounds tested showed positive results for fungi Candida albicans nor against fungi Aspergillus niger. Chalcone derivatives showed inhibitory effect against M. gypseum species of fungus. It was found that among the chalcone derivatives so synthesized, two of them, that is, 4-chloro derivative, and unsubstituted derivative of chalcone showed antifungal activity superior to ketoconazole. Thus, these can be the potential new molecule as antifungal agent. PMID:26317075

  16. Toxicity and sublethal effects of six insecticides to last instar larvae and adults of the biocontrol agents Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and Adalia bipunctata (L.) (Coleoptera: Coccinellidae).

    PubMed

    Garzón, A; Medina, P; Amor, F; Viñuela, E; Budia, F

    2015-08-01

    To further develop Integrated Pest Management (IPM) strategies against crop pests, it is important to evaluate the effects of insecticides on biological control agents. Therefore, we tested the toxicity and sublethal effects (fecundity and fertility) of flonicamid, flubendiamide, metaflumizone, spirotetramat, sulfoxaflor and deltamethrin on the natural enemies Chrysoperla carnea and Adalia bipunctata. The side effects of the active ingredients of the insecticides were evaluated with residual contact tests for the larvae and adults of these predators in the laboratory. Flonicamid, flubendiamide, metaflumizone and spirotetramat were innocuous to last instar larvae and adults of C. carnea and A. bipunctata. Sulfoxaflor was slightly toxic to adults of C. carnea and was highly toxic to the L4 larvae of A. bipunctata. For A. bipunctata, sulfoxaflor and deltamethrin were the most damaging compounds with a cumulative larval mortality of 100%. Deltamethrin was also the most toxic compound to larvae and adults of C. carnea. In accordance with the results obtained, the compounds flonicamid, flubendiamide, metaflumizone and spirotetramat might be incorporated into IPM programs in combination with these natural enemies for the control of particular greenhouse pests. Nevertheless, the use of sulfoxaflor and deltamethrin in IPM strategies should be taken into consideration when releasing either of these biological control agents, due to the toxic behavior observed under laboratory conditions. The need for developing sustainable approaches to combine the use of these insecticides and natural enemies within an IPM framework is discussed.

  17. Potential for Water Salvage by Release of the Biocontrol Beetle, Diorhabda carinulata, on Tamarisk (Tamarix ramosissima) Dominated Western U.S. Rivers

    NASA Astrophysics Data System (ADS)

    Murray, R. S.; Nagler, P. L.; van Riper, C.; Bean, D.; Glenn, E. P.

    2009-12-01

    The biocontrol beetle, Diorhabda carinulata, has been widely released in the upper basin of the Colorado River to control Tamarisk in the western U.S. A primary motivation for beetle release is to salvage water that would otherwise be lost to transpiration by Tamarisk. We summarize preliminary findings of our assessment of tamarisk, beetle and avian phenology and tamarisk water usage. We used the Enhanced Vegetation Index (EVI) from the MODIS sensors on the Terra satellite to evaluate the prospects for water salvage at 15 riparian release sites in Utah, Colorado, Nevada and Wyoming. EVI was combined with meteorological data to estimate evapotranspiration (ET) at the release sites and in adjacent sites to which the beetle might have spread. ET was estimated at 16-day intervals from 2000 to 2008, encompassing pre-release and post-release periods at each site. Baseline ET rates tended to be low, from 2-6 mm d-1 in summer (less than half of potential ET). At 4 of 15 sites, ET rates estimated by MODIS EVI decreased markedly one to two years after release. At other sites, however, no decrease in ET was detected, and ET tended to recover to pre-release levels at affected sites. Ground observations confirmed that beetles were active at all sites following release, defoliating stands of Tamarisk over areas as large as 200 ha. Along approximately 300 km of the Dolores and Colorado Rivers, ground based monitoring of tamarisk defoliation and refoliation was done using hand held GPS units and GIS software. Monitoring here began at the time beetles entered the system in 2004. Selected sites (15 ha) were also monitored for beetle presence and life stage as well as tamarisk condition. Additional ground data collected at four sites on the Dolores River includes vegetation structure, composition and phenology as well as bird monitoring and productivity. The four sites are dominated by saltcedar, with components of willow and cottonwood. For the last 3 years, monthly monitoring of

  18. Securinine, a Myeloid Differentiation Agent with Therapeutic Potential for AML

    PubMed Central

    Gupta, Kalpana; Chakrabarti, Amitabha; Rana, Sonia; Ramdeo, Ritu; Roth, Bryan L.; Agarwal, Munna L.; Tse, William; Agarwal, Mukesh K.; Wald, David N.

    2011-01-01

    As the defining feature of Acute Myeloid Leukemia (AML) is a maturation arrest, a highly desirable therapeutic strategy is to induce leukemic cell maturation. This therapeutic strategy has the potential of avoiding the significant side effects that occur with the traditional AML therapeutics. We identified a natural compound securinine, as a leukemia differentiation-inducing agent. Securinine is a plant-derived alkaloid that has previously been used clinically as a therapeutic for primarily neurological related diseases. Securinine induces monocytic differentiation of a wide range of myeloid leukemia cell lines as well as primary leukemic patient samples. Securinine's clinical potential for AML can be seen from its ability to induce significant growth arrest in cell lines and patient samples as well as its activity in significantly impairing the growth of AML tumors in nude mice. In addition, securinine can synergize with currently employed agents such as ATRA and decitabine to induce differentiation. This study has revealed securinine induces differentiation through the activation of DNA damage signaling. Securinine is a promising new monocytic differentiation inducing agent for AML that has seen previous clinical use for non-related disorders. PMID:21731671

  19. Magnetic nanobeads as potential contrast agents for magnetic resonance imaging.

    PubMed

    Pablico-Lansigan, Michele H; Hickling, William J; Japp, Emily A; Rodriguez, Olga C; Ghosh, Anup; Albanese, Chris; Nishida, Maki; Van Keuren, Edward; Fricke, Stanley; Dollahon, Norman; Stoll, Sarah L

    2013-10-22

    Metal-oxo clusters have been used as building blocks to form hybrid nanomaterials and evaluated as potential MRI contrast agents. We have synthesized a biocompatible copolymer based on a water stable, nontoxic, mixed-metal-oxo cluster, Mn8Fe4O12(L)16(H2O)4, where L is acetate or vinyl benzoic acid, and styrene. The cluster alone was screened by NMR for relaxivity and was found to be a promising T2 contrast agent, with r1 = 2.3 mM(-1) s(-1) and r2 = 29.5 mM(-1) s(-1). Initial cell studies on two human prostate cancer cell lines, DU-145 and LNCap, reveal that the cluster has low cytotoxicity and may be potentially used in vivo. The metal-oxo cluster Mn8Fe4(VBA)16 (VBA = vinyl benzoic acid) can be copolymerized with styrene under miniemulsion conditions. Miniemulsion allows for the formation of nanometer-sized paramagnetic beads (~80 nm diameter), which were also evaluated as a contrast agent for MRI. These highly monodispersed, hybrid nanoparticles have enhanced properties, with the option for surface functionalization, making them a promising tool for biomedicine. Interestingly, both relaxivity measurements and MRI studies show that embedding the Mn8Fe4 core within a polymer matrix decreases r2 effects with little effect on r1, resulting in a positive T1 contrast enhancement.

  20. Potential new agents for chronic lymphocytic leukemia treatment.

    PubMed

    Kiliańska, Zofia M; Rogalińska, Małgorzata

    2010-11-01

    Chronic lymphocytic leukemia (CLL) is the most frequent type of hematological cancer in the Western World. An accumulation of leukemic cells in peripheral blood of patients is a result of apoptosis disturbances as well as an increase in germinal centers CLL cell proliferation. The differences between CLL patients in the course and response to therapy reflects personal variability between patients in their genetic material. It was documented that many sufferers from CLL are over 60 years old, and because of many countries' population obsolescence this type of leukemia could become more frequent in the future. CLL remains incurable, and the therapy regimens available at present could induce even complete remissions, but finally a relapse of the disease. The etiology of this disease is still not known, but our understanding of the processes running in CLL cells has significantly increased. A number of new agents with potential of CLL cell elimination by apoptosis or autophagy were characterized. Some of them reflect potential in cell sensitization to standard therapy. The major challenge for the future is to develop targeted anti-cancer therapy and design the optimal personalized manner of CLL treatment. A special interest is focused on anti-cancer agents - natural substances of plant origin. This paper reviews chosen new anti-leukemic agents belonging to different drug-classes (new monoclonal antibodies or apoptosis-, BCR signaling- and cell cycle-related inhibitors, substances of plant origin) which are under intense investigation in preclinical studies and early clinical trials. PMID:21235440

  1. Biological Control Potential of Bacillus amyloliquefaciens KB3 Isolated from the Feces of Allomyrina dichotoma Larvae

    PubMed Central

    Nam, Hyo-Song; Yang, Hyun-Ju; Oh, Byung Jun; Anderson, Anne J.; Kim, Young Cheol

    2016-01-01

    Most biocontrol agents for plant diseases have been isolated from sources such as soils and plants. As an alternative source, we examined the feces of tertiary larvae of the herbivorous rhino beetle, Allomyrina dichotoma for presence of biocontrol-active microbes. The initial screen was performed to detect antifungal activity against two common fungal plant pathogens. The strain with strongest antifungal activity was identified as Bacillus amyloliquefaciens KB3. The inhibitory activity of this strain correlated with lipopeptide productions, including iturin A and surfactin. Production of these surfactants in the KB3 isolate varied with the culture phase and growth medium used. In planta biocontrol activities of cell-free culture filtrates of KB3 were similar to those of the commercial biocontrol agent, B. subtilis QST-713. These results support the presence of microbes with the potential to inhibit fungal growth, such as plant pathogens, in diverse ecological niches. PMID:27298603

  2. Draft Genome Sequence of a Biocontrol Rhizobacterium, Chryseobacterium kwangjuense Strain KJ1R5, Isolated from Pepper (Capsicum annuum)

    PubMed Central

    Jeong, Jin-Ju; Park, Hongjae; Park, Byeong Hyeok; Mannaa, Mohamed; Sang, Mee Kyung

    2016-01-01

    Strain KJ1R5 of the rhizobacterium Chryseobacterium kwangjuense is an effective biocontrol agent against Phytophthora blight of pepper caused by a destructive soilborne oomycete, Phytophthora capsici. Here, we present the draft genome sequence of strain KJ1R5, which contains genes related to biocontrol, plant growth promotion, and environmental stress adaptation. PMID:27103726

  3. Molecular markers discriminate closely related Encarsia spp. (E. diaspidicola and E. berlesei): candidate biocontrol agents for white peach scale in Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The white peach scale (WPS), Pseudaulacaspis pentagona Targioni-Tozetti (Hemiptera: Diaspididae) is a serious economic pest of papaya in Hawaii. In 2006, Encarsia diaspidicola Silvestri (Hymenoptera: Aphelinidae) was imported from Samoa to perform host-range studies. Another potential future candi...

  4. Molecular markers discriminate closely related species, Encarsia diaspidicola and E. berlesei (Hymenoptera: Aphelinidae): Biocontrol candidate agents for white peach scale in Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The white peach scale, Pseudaulacaspis pentagona Targioni-Tozetti (Hemiptera: Diaspididae), is a serious economic pest of papaya in Hawaii. The endoparasitoid Encarsia diaspidicola Silvestri (Hymenoptera: Aphelinidae) was imported from Samoa into quarantine in Hawaii to be evaluated for potential r...

  5. Terpenoids as potential chemopreventive and therapeutic agents in liver cancer

    PubMed Central

    Thoppil, Roslin J; Bishayee, Anupam

    2011-01-01

    Despite significant advances in medicine, liver cancer, predominantly hepatocellular carcinoma remains a major cause of death in the United States as well as the rest of the world. As limited treatment options are currently available to patients with liver cancer, novel preventive control and effective therapeutic approaches are considered to be reasonable and decisive measures to combat this disease. Several naturally occurring dietary and non-dietary phytochemicals have shown enormous potential in the prevention and treatment of several cancers, especially those of the gastrointestinal tract. Terpenoids, the largest group of phytochemicals, traditionally used for medicinal purposes in India and China, are currently being explored as anticancer agents in clinical trials. Terpenoids (also called “isoprenoids”) are secondary metabolites occurring in most organisms, particularly plants. More than 40 000 individual terpenoids are known to exist in nature with new compounds being discovered every year. A large number of terpenoids exhibit cytotoxicity against a variety of tumor cells and cancer preventive as well as anticancer efficacy in preclinical animal models. This review critically examines the potential role of naturally occurring terpenoids, from diverse origins, in the chemoprevention and treatment of liver tumors. Both in vitro and in vivo effects of these agents and related cellular and molecular mechanisms are highlighted. Potential challenges and future directions involved in the advancement of these promising natural compounds in the chemoprevention and therapy of human liver cancer are also discussed. PMID:21969877

  6. Potential central nervous system antitumor agents. Aziridinylbenzoquinones. 1.

    PubMed

    Khan, A H; Driscoll, J S

    1976-02-01

    A series of 3,6-substituted 2,5-diaziridinyl-1,4-benzoquinones was prepared as potential CNS antitumor agents. Activity was evaluated in the murine leukemia L1210 system. The diurethane derivative 9 was found to have significant activity in that system as well as in the intraperitoneal P388 and B16 tumor models. Marginal Lewis lung activity was observed. Reproducible activity was seen in the intracerebral L1210 and P388 systems. Multiple cures were observed in the murine ependymoblastoma brain tumor model. The effect of substituent type on aziridinylquinone activity is discussed.

  7. Hypoglycemic agents and potential anti-inflammatory activity

    PubMed Central

    Kothari, Vishal; Galdo, John A; Mathews, Suresh T

    2016-01-01

    Current literature shows an association of diabetes and secondary complications with chronic inflammation. Evidence of these immunological changes include altered levels of cytokines and chemokines, changes in the numbers and activation states of various leukocyte populations, apoptosis, and fibrosis during diabetes. Therefore, treatment of diabetes and its complications may include pharmacological strategies to reduce inflammation. Apart from anti-inflammatory drugs, various hypoglycemic agents have also been found to reduce inflammation that could contribute to improved outcomes. Extensive studies have been carried out with thiazolidinediones (peroxisome proliferator-activated receptor-γ agonist), dipeptidyl peptidase-4 inhibitors, and metformin (AMP-activated protein kinase activator) with each of these classes of compounds showing moderate-to-strong anti-inflammatory action. Sulfonylureas and alpha glucosidase inhibitors appeared to exert modest effects, while the injectable agents, insulin and glucagon-like peptide-1 receptor agonists, may improve secondary complications due to their anti-inflammatory potential. Currently, there is a lack of clinical data on anti-inflammatory effects of sodium–glucose cotransporter type 2 inhibitors. Nevertheless, for all these glucose-lowering agents, it is essential to distinguish between anti-inflammatory effects resulting from better glucose control and effects related to intrinsic anti-inflammatory actions of the pharmacological class of compounds. PMID:27114714

  8. Underestimated potential of organometallic rhenium complexes as anticancer agents.

    PubMed

    Leonidova, Anna; Gasser, Gilles

    2014-10-17

    In the recent years, organometallic compounds have become recognized as promising anti-cancer drug candidates. While radioactive (186/188)Re compounds are already used in clinics for cancer treatment, cold Re organometallic compounds have mostly been explored as luminescent probes for cell imaging and photosensitizers in photocatalysis. However, a growing number of studies have recently revealed the potential of Re organometallic complexes as anti-cancer agents. Several compounds have displayed cytotoxicity equaling or exceeding that of the well-established anti-cancer drug cisplatin. In this review, we present the currently known Re organometallic complexes that have shown anti-proliferative activity on cancer cell lines. A particular emphasis is placed on their cellular uptake and localization as well as their potential mechanism of action.

  9. Artocarpus plants as a potential source of skin whitening agents.

    PubMed

    Arung, Enos Tangke; Shimizu, Kuniyoshi; Kondo, Ryuichiro

    2011-09-01

    Artocarpus plants have been a focus of constant attention due to the potential for skin whitening agents. In the in vitro experiment, compounds from the Artocarpus plants, such as artocarpanone, norartocarpetin, artocarpesin, artogomezianol, andalasin, artocarbene, and chlorophorin showed tyrosinase inhibitory activity. Structure-activity investigations revealed that the 4-substituted resorcinol moiety in these compounds was responsible for their potent inhibitory activities on tyrosinase. In the in vitro assay, using B16 melanoma cells, the prenylated polyphenols isolated from Artocarpus plants, such as artocarpin, cudraflavone C, 6-prenylapigenin, kuwanon C, norartocarpin, albanin A, cudraflavone B, and brosimone I showed potent inhibitory activity on melanin formation. Structure-activity investigations revealed that the introduction of an isoprenoid moiety to a non-isoprenoid-substituted polyphenol enhanced the inhibitory activity of melanin production in B16 melanoma cells. In the in vivo investigation, the extract of the wood of Artocarpus incisus and a representative isolated compound from it, artocarpin had a lightening effect on the skin of guinea pigs' backs. Other in vivo experiments using human volunteers have shown that water extract of Artocarpus lakoocha reduced the melanin formation in the skin of volunteers. These results indicate that the extracts of Artocarpus plants are potential sources for skin whitening agents.

  10. Turning on the Radio: Epigenetic Inhibitors as Potential Radiopriming Agents

    PubMed Central

    Oronsky, Bryan; Scicinski, Jan; Kim, Michelle M.; Cabrales, Pedro; Salacz, Michael E.; Carter, Corey A.; Oronsky, Neil; Lybeck, Harry; Lybeck, Michelle; Larson, Christopher; Reid, Tony R.; Oronsky, Arnold

    2016-01-01

    First introduced during the late 1800s, radiation therapy is fundamental to the treatment of cancer. In developed countries, approximately 60% of all patients receive radiation therapy (also known as the sixty percenters), which makes radioresistance in cancer an important and, to date, unsolved, clinical problem. Unfortunately, the therapeutic refractoriness of solid tumors is the rule not the exception, and the ubiquity of resistance also extends to standard chemotherapy, molecularly targeted therapy and immunotherapy. Based on extrapolation from recent clinical inroads with epigenetic agents to prime refractory tumors for maximum sensitivity to concurrent or subsequent therapies, the radioresistant phenotype is potentially reversible, since aberrant epigenetic mechanisms are critical contributors to the evolution of resistant subpopulations of malignant cells. Within the framework of a syllogism, this review explores the emerging link between epigenetics and the development of radioresistance and makes the case that a strategy of pre- or co-treatment with epigenetic agents has the potential to, not only derepress inappropriately silenced genes, but also increase reactive oxygen species production, resulting in the restoration of radiosensitivity. PMID:27384589

  11. Biological activities of phosphocitrate: a potential meniscal protective agent.

    PubMed

    Sun, Yubo; Roberts, Andrea; Mauerhan, David R; Sun, Andrew R; Norton, H James; Hanley, Edward N

    2013-01-01

    Phosphocitrate (PC) inhibited meniscal calcification and the development of calcium crystal-associated osteoarthritis (OA) in Hartley guinea pigs. However, the mechanisms remain elusive. This study sought to examine the biological activities of PC in the absence of calcium crystals and test the hypothesis that PC is potentially a meniscal protective agent. We found that PC downregulated the expression of many genes classified in cell proliferation, ossification, prostaglandin metabolic process, and wound healing, including bloom syndrome RecQ helicase-like, cell division cycle 7 homolog, cell division cycle 25 homolog C, ankylosis progressive homolog, prostaglandin-endoperoxide synthases-1/cyclooxygenase-1, and plasminogen activator urokinase receptor. In contrast, PC stimulated the expression of many genes classified in fibroblast growth factor receptor signaling pathway, collagen fibril organization, and extracellular structure organization, including fibroblast growth factor 7, collagen type I, alpha 1, and collagen type XI, alpha 1. Consistent with its effect on the expression of genes classified in cell proliferation, collagen fibril organization, and ossification, PC inhibited the proliferation of OA meniscal cells and meniscal cell-mediated calcification while stimulating the production of collagens. These findings indicate that PC is potentially a meniscal-protective agent and a disease-modifying drug for arthritis associated with severe meniscal degeneration. PMID:23936839

  12. Mi-1.2, an R gene for aphid resistance in tomato, has direct negative effects on a zoophytophagous biocontrol agent, Orius insidiosus

    PubMed Central

    Pallipparambil, Godshen R.; Sayler, Ronald J.; Shapiro, Jeffrey P.; Thomas, Jean M. G.; Kring, Timothy J.; Goggin, Fiona L.

    2015-01-01

    Mi-1.2 is a single dominant gene in tomato that confers race-specific resistance against certain phloem-feeding herbivores including aphids, whiteflies, psyllids, and root-knot nematodes. Few prior studies have considered the potential non-target effects of race-specific resistance genes (R genes), and this paper evaluates the compatibility of Mi-mediated resistance in tomato with a beneficial zoophytophagous predator, Orius insidiosus (Say). In addition to preying on aphids and other pests, this piercing–sucking insect also feeds from the xylem, epidermis, and/or mesophyll, and oviposits within plant tissues. Comparison of O. insidiosus confined to isogenic tomato plants with and without Mi-1.2 revealed that immatures of O. insidiosus had lower survival on resistant plants even when the immatures were provisioned with prey that did not feed on the host plant. Molecular gut content analysis confirmed that adults and immatures of O. insidiosus feed on both resistant (Mi-1.2+) and susceptible (Mi-1.2–) genotypes, and bioassays suggest that resistance does not affect oviposition rates, plant sampling, or prey acceptance by O. insidiosus adults. These results demonstrate a direct negative impact of R-gene-mediated host plant resistance on a non-target beneficial species, and reveal that Mi-mediated resistance can impact organisms that do not feed on phloem sap. Through laser capture microdissection and RT-PCR, Mi-1.2 transcripts were detected in the epidermis and mesophyll as well as the phloem of tomato plants, consistent with our observations that Mi-mediated resistance is active outside the phloem. These results suggest that the mode of action and potential ecological impacts of Mi-mediated resistance are broader than previously assumed. PMID:25189594

  13. Potential anti-HIV agents from marine resources: an overview.

    PubMed

    Vo, Thanh-Sang; Kim, Se-Kwon

    2010-11-29

    Human immunodeficiency virus (HIV) infection causes acquired immune deficiency syndrome (AIDS) and is a global public health issue. Anti-HIV therapy involving chemical drugs has improved the life quality of HIV/AIDS patients. However, emergence of HIV drug resistance, side effects and the necessity for long-term anti-HIV treatment are the main reasons for failure of anti-HIV therapy. Therefore, it is essential to isolate novel anti-HIV therapeutics from natural resources. Recently, a great deal of interest has been expressed regarding marine-derived anti-HIV agents such as phlorotannins, sulfated chitooligosaccharides, sulfated polysaccharides, lectins and bioactive peptides. This contribution presents an overview of anti-HIV therapeutics derived from marine resources and their potential application in HIV therapy.

  14. Potential Anti-HIV Agents from Marine Resources: An Overview

    PubMed Central

    Vo, Thanh-Sang; Kim, Se-Kwon

    2010-01-01

    Human immunodeficiency virus (HIV) infection causes acquired immune deficiency syndrome (AIDS) and is a global public health issue. Anti-HIV therapy involving chemical drugs has improved the life quality of HIV/AIDS patients. However, emergence of HIV drug resistance, side effects and the necessity for long-term anti-HIV treatment are the main reasons for failure of anti-HIV therapy. Therefore, it is essential to isolate novel anti-HIV therapeutics from natural resources. Recently, a great deal of interest has been expressed regarding marine-derived anti-HIV agents such as phlorotannins, sulfated chitooligosaccharides, sulfated polysaccharides, lectins and bioactive peptides. This contribution presents an overview of anti-HIV therapeutics derived from marine resources and their potential application in HIV therapy. PMID:21339954

  15. Aptamer Oligonucleotides: Novel Potential Therapeutic Agents in Autoimmune Disease.

    PubMed

    Li, Weibin; Lan, Xiaopeng

    2015-08-01

    Aptamers are single-stranded deoxyribonucleic acid or ribonucleic acid oligonucleotides generated in vitro based on affinity for certain target molecules by a process known as Systematic Evolution of Ligands by Exponential Enrichment. Aptamers can bind their target molecules with high specificity and selectivity by means of structure compatibility, stacking of aromatic rings, electrostatic and van der Waals interactions, and hydrogen bonding. With several advantages over monoclonal antibodies and other conventional small-molecule therapeutics, such as high specificity and affinity, negligible batch to batch variation, flexible modification and stability, lack of toxicity and low immunogenicity, aptamers are becoming promising novel diagnostic and therapeutic agents. This review focuses on the development of aptamers as potential therapeutics for autoimmune diseases, including diabetes mellitus, multiple sclerosis, rheumatoid arthritis, myasthenia gravis, and systemic lupus erythematosus. PMID:25993618

  16. Application of biocontrol agents in forest nurseries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bare-root conifer seedling culture consists of growing seedlings (sown or transplanted) in soil, and is the predominant method for supplying America’s need for healthy regeneration stock to produce and sustain forests, wildlife food sources, fiber, wood products, paper, bio-pharmaceuticals and now p...

  17. Can generalist predators be effective biocontrol agents?

    PubMed

    Symondson, W O C; Sunderland, K D; Greenstone, M H

    2002-01-01

    Theoretical developments are helping us to comprehend the basic parameters governing the dynamics of the interactions between generalist predators and their many pest and nonpest prey. In practice, however, inter- and intraspecific interactions between generalist predators, and between the predators and their prey, within multispecies systems under the influence of rapidly changing biotic and abiotic variables are difficult to predict. We discuss trade-offs between the relative merits of specialists and generalists that allow both to be effective, and often complementary, under different circumstances. A review of manipulative field studies showed that in approximately 75% of cases, generalist predators, whether single species or species assemblages, reduced pest numbers significantly. Techniques for manipulating predator numbers to enhance pest control at different scales are discussed. We now need to find ways of disentangling the factors influencing positive and negative interactions within natural enemy communities in order to optimize beneficial synergies leading to pest control.

  18. Production Methods for Microbial Biocontrol Agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A critical constraint to the commercial use of microbial biopesticides is the development of an economic production process. The production process must be cost-effective and yield a microbial propagule that is stable and efficacious under field conditions. Currently, the commercial production of ...

  19. Selection of the N-Acylhomoserine Lactone-Degrading Bacterium Alteromonas stellipolaris PQQ-42 and of Its Potential for Biocontrol in Aquaculture.

    PubMed

    Torres, Marta; Rubio-Portillo, Esther; Antón, Josefa; Ramos-Esplá, Alfonso A; Quesada, Emilia; Llamas, Inmaculada

    2016-01-01

    The production of virulence factors by many pathogenic microorganisms depends on the intercellular communication system called quorum sensing, which involves the production and release of signal molecules known as autoinducers. Based on this, new-therapeutic strategies have emerged for the treatment of a variety of infections, such as the enzymatic degradation of signaling molecules, known as quorum quenching (QQ). In this study, we present the screening of QQ activity amongst 450 strains isolated from a bivalve hatchery in Granada (Spain), and the selection of the strain PQQ-42, which degrades a wide range of N-acylhomoserine lactones (AHLs). The selected strain, identified as Alteromonas stellipolaris, degraded the accumulation of AHLs and reduced the production of protease and chitinase and swimming motility of a Vibrio species in co-cultivation experiments in vitro. In the bio-control experiment, strain PQQ-42 significantly reduced the pathogenicity of Vibrio mediterranei VibC-Oc-097 upon the coral Oculina patagonica showing a lower degree of tissue damage (29.25 ± 14.63%) in its presence, compared to when the coral was infected with V. mediterranei VibC-Oc-097 alone (77.53 ± 13.22%). Our results suggest that this AHL-degrading bacterium may have biotechnological applications in aquaculture.

  20. Soil type-dependent effects of a potential biocontrol inoculant on indigenous bacterial communities in the rhizosphere of field-grown lettuce.

    PubMed

    Schreiter, Susanne; Ding, Guo-Chun; Grosch, Rita; Kropf, Siegfried; Antweiler, Kai; Smalla, Kornelia

    2014-12-01

    Bacterial biocontrol strains used as an alternative to chemical fungicides may influence bacterial communities in the rhizosphere and effects might differ depending on the soil type. Here we present baseline data on the effects of Pseudomonas jessenii RU47 on the bacterial community composition in the rhizosphere of lettuce grown in diluvial sand, alluvial loam and loess loam at the same field site. 16S rRNA gene fragments amplified from total community DNA were analyzed by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. DGGE fingerprints revealed that in three consecutive years (2010-2012) RU47 had a slight but statistically significant effect on the bacterial community composition in one (2010), two (2011) or all the three soils (2012). However, these effects were much less pronounced compared with the influence of soil types. Additional pyrosequence analysis of samples from 2011 showed that significant changes in bacterial community compositions in response to RU47 inoculation occurred only in alluvial loam. Different taxonomic groups responded to the RU47 application depending on the soil type. Most remarkable was the increased relative abundance of OTUs belonging to the genera Bacillus and Paenibacillus in alluvial loam. Pyrosequencing allowed side-effects of the application of bacterial inoculants into the rhizosphere to be identified. PMID:25244497

  1. Selection of the N-Acylhomoserine Lactone-Degrading Bacterium Alteromonas stellipolaris PQQ-42 and of Its Potential for Biocontrol in Aquaculture

    PubMed Central

    Torres, Marta; Rubio-Portillo, Esther; Antón, Josefa; Ramos-Esplá, Alfonso A.; Quesada, Emilia; Llamas, Inmaculada

    2016-01-01

    The production of virulence factors by many pathogenic microorganisms depends on the intercellular communication system called quorum sensing, which involves the production and release of signal molecules known as autoinducers. Based on this, new-therapeutic strategies have emerged for the treatment of a variety of infections, such as the enzymatic degradation of signaling molecules, known as quorum quenching (QQ). In this study, we present the screening of QQ activity amongst 450 strains isolated from a bivalve hatchery in Granada (Spain), and the selection of the strain PQQ-42, which degrades a wide range of N-acylhomoserine lactones (AHLs). The selected strain, identified as Alteromonas stellipolaris, degraded the accumulation of AHLs and reduced the production of protease and chitinase and swimming motility of a Vibrio species in co-cultivation experiments in vitro. In the bio-control experiment, strain PQQ-42 significantly reduced the pathogenicity of Vibrio mediterranei VibC-Oc-097 upon the coral Oculina patagonica showing a lower degree of tissue damage (29.25 ± 14.63%) in its presence, compared to when the coral was infected with V. mediterranei VibC-Oc-097 alone (77.53 ± 13.22%). Our results suggest that this AHL-degrading bacterium may have biotechnological applications in aquaculture. PMID:27242684

  2. Investigation of acetylated chitosan microspheres as potential chemoembolic agents.

    PubMed

    Zhou, Xuan; Kong, Ming; Cheng, Xiaojie; Li, Jingjing; Li, Jing; Chen, Xiguang

    2014-11-01

    The aim was to investigate the potential of chitosan microspheres (CMs) with different acetylation using as a chemoembolic agent. Chitosan microspheres (CMs) were prepared via water-in-oil (W/O) emulsification cross-linking method, and acetylated chitosan microspheres (ACMs) were obtained by acetylation of CMs. Next, we characterized the morphology, size, composition and degrees of deacetylation using scanning electron microscopy (TEM), dynamic laser light scattering (DLS), and Fourier transform infrared spectrometer (FTIR). All microspheres had smooth surfaces and good mechanical flexibility, and all could pass through a 5F catheter. The swelling rate (SR) of CMs decreased significantly with the increase of pH (4.0-10.0) but ACMs did not change under the same conditions. Protein absorption assays suggested that albumin was more greatly adsorbed on CMs than on ACMs. Furthermore, CMs caused more blood clots than ACMs. ACMs caused hemolysis less than CMs (<5% of the time). Data indicated that ACMs had more hemocompatibility. Cytotoxicity tests indicated that ACMs initially had less cell attached proliferation but increased with incubation. In contrast, the relative growth rate of mouse embryo fibroblasts (MEFs) on CMs decreased gradually. The results suggested that ACMs could stimulate the growth of MEFs, and CMs were not cytotoxic to MEFs. Thus, ACMs were more biocompatible with greater potential to be used as chemoembolic material.

  3. Saprotrophic competitiveness and biocontrol fitness of a genetically modified strain of the plant-growth-promoting fungus Trichoderma hamatum GD12.

    PubMed

    Ryder, Lauren S; Harris, Beverley D; Soanes, Darren M; Kershaw, Michael J; Talbot, Nicholas J; Thornton, Christopher R

    2012-01-01

    Trichoderma species are ubiquitous soil fungi that hold enormous potential for the development of credible alternatives to agrochemicals and synthetic fertilizers in sustainable crop production. In this paper, we show that substantial improvements in plant productivity can be met by genetic modification of a plant-growth-promoting and biocontrol strain of Trichoderma hamatum, but that these improvements are obtained in the absence of disease pressure only. Using a quantitative monoclonal antibody-based ELISA, we show that an N-acetyl-β-d-glucosaminidase-deficient mutant of T. hamatum, generated by insertional mutagenesis of the corresponding gene, has impaired saprotrophic competitiveness during antagonistic interactions with Rhizoctonia solani in soil. Furthermore, its fitness as a biocontrol agent of the pre-emergence damping-off pathogen Sclerotinia sclerotiorum is significantly reduced, and its ability to promote plant growth is constrained by the presence of both pathogens. This work shows that while gains in T. hamatum-mediated plant-growth-promotion can be met through genetic manipulation of a single beneficial trait, such a modification has negative impacts on other aspects of its biology and ecology that contribute to its success as a saprotrophic competitor and antagonist of soil-borne pathogens. The work has important implications for fungal morphogenesis, demonstrating a clear link between hyphal architecture and secretory potential. Furthermore, it highlights the need for a holistic approach to the development of genetically modified Trichoderma strains for use as crop stimulants and biocontrol agents in plant agriculture.

  4. Viral biocontrol: grand experiments in disease emergence and evolution

    PubMed Central

    Di Giallonardo, Francesca; Holmes, Edward C.

    2014-01-01

    Although viral emergence is commonly associated with cross-species transmission, the processes and determinants of viral evolution in a novel host environment are poorly understood. We address key questions in virus emergence and evolution using data generated from two unique natural experiments: the deliberate release of myxoma virus (MYXV) and rabbit hemorrhagic disease virus (RHDV) as biological control (biocontrol) agents against the European rabbit in Australia, and which have been of enormous benefit to Australia’s ecosystem and agricultural industries. Notably, although virulence evolution in MYXV and RHDV followed different trajectories, a strongly parallel evolutionary process was observed in Australia and Europe. These biocontrol agents were also characterised by a lack of transmission to non-target host species, suggesting that there are major barriers to successful emergence. PMID:25455418

  5. Host specificity of Argopistes tsekooni (Coleoptera: Chrysomelidae), a potential biological control agent of Chinese privet.

    PubMed

    Zhang, Yan-Zhuo; Hanula, James L; Sun, Jiang-Hua

    2008-08-01

    Chinese privet, Ligustrum sinense Lour., is a perennial semi-evergreen shrub that is a serious invasive weed in the United States. Classical biological control offers the best hope for controlling it in an economic, effective, and persistent way. Host specificity of one of the most promising biological control agents of Chinese privet, a flea beetle, Argopistes tsekooni Chen (Coleoptera: Chrysomelidae), was evaluated in China by using laboratory no-choice and choice tests on 13 species of Oleaceae and eight species in other families that have important economic value. In adult no-choice survival and oviposition tests, the flea beetle fed and survived for 30 d on Syringa oblata Lindl., Jasminum nudiflorum Lindl., and three species in the genus Ligustrum. Females also oviposited on these species, but only larvae from eggs laid on S. oblata and Ligustrum spp. developed successfully. In addition, the beetles did not feed or oviposit on the species of economic importance. In choice tests, adults preferred L. sinense for feeding and oviposition. These results show that A. tsekooni is relatively host specific and warrants further testing as a biocontrol agent of Chinese privet in the United States. PMID:18767722

  6. Marine Diterpenoids as Potential Anti-Inflammatory Agents.

    PubMed

    González, Yisett; Torres-Mendoza, Daniel; Jones, Gillian E; Fernandez, Patricia L

    2015-01-01

    The inflammatory response is a highly regulated process, and its dysregulation can lead to the establishment of chronic inflammation and, in some cases, to death. Inflammation is the cause of several diseases, including rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, and asthma. The search for agents inhibiting inflammation is a great challenge as the inflammatory response plays an important role in the defense of the host to infections. Marine invertebrates are exceptional sources of new natural products, and among those diterpenoids secondary metabolites exhibit notable anti-inflammatory properties. Novel anti-inflammatory diterpenoids, exclusively produced by marine organisms, have been identified and synthetic molecules based on those structures have been obtained. The anti-inflammatory activity of marine diterpenoids has been attributed to the inhibition of Nuclear Factor-κB activation and to the modulation of arachidonic acid metabolism. However, more research is necessary to describe the mechanisms of action of these secondary metabolites. This review is a compilation of marine diterpenoids, mainly isolated from corals, which have been described as potential anti-inflammatory molecules. PMID:26538822

  7. Radioiodinated carnitine and acylcarnitine analogs as potential myocardial imaging agents

    SciTech Connect

    McConnell, D.S.

    1991-01-01

    R-carnitine is extremely important in mammalian energy metabolism. Gamma-butyrobetaine, the immediate biosynthetic precursor to R-carnitine, is synthesized in many organs. However, only liver can hydroxylate gamma-butyrobetaine to carnitine. Thus the transport of carnitine from its site of synthesis to the site of utilization is of utmost importance. Carnitine is found in highest concentration in cardiac and skeletal muscle, where it is required for the transport of fatty acids into the mitochondria. Before fatty acids are utilized as fuel for the myocyte by beta-oxidation, they are bound to carnitine as an acylcarnitine ester at the 3-hydroxyl, and transported across the micochondrial membranes. R,S-Carnitine has been shown to be taken up by myocytes. The author has begun a study on the use of carnitine derivatives as potential carriers for the site-specific delivery of radioiodine to bidning sites in the myocardium. Such agents labeled with a gamma-emitting nuclide such as iodine-123 would be useful for the noninvasive imaging of these tissues. The aim was to synthesize a variety of radiolabeled analogs of carnitine and acylcarnitine to address questions of transport, binding and availability for myocardial metabolism. These analogs consist of N-alkylated derivatives of carnitine, acylcarnitine esters as well as carnitine amides and ethers. One C-alkylated derivative showed interesting biodistribution, elevated myocardial uptake and competition with carnitine for binding in the myocardium.

  8. Marine Diterpenoids as Potential Anti-Inflammatory Agents

    PubMed Central

    González, Yisett; Torres-Mendoza, Daniel; Jones, Gillian E.; Fernandez, Patricia L.

    2015-01-01

    The inflammatory response is a highly regulated process, and its dysregulation can lead to the establishment of chronic inflammation and, in some cases, to death. Inflammation is the cause of several diseases, including rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, and asthma. The search for agents inhibiting inflammation is a great challenge as the inflammatory response plays an important role in the defense of the host to infections. Marine invertebrates are exceptional sources of new natural products, and among those diterpenoids secondary metabolites exhibit notable anti-inflammatory properties. Novel anti-inflammatory diterpenoids, exclusively produced by marine organisms, have been identified and synthetic molecules based on those structures have been obtained. The anti-inflammatory activity of marine diterpenoids has been attributed to the inhibition of Nuclear Factor-κB activation and to the modulation of arachidonic acid metabolism. However, more research is necessary to describe the mechanisms of action of these secondary metabolites. This review is a compilation of marine diterpenoids, mainly isolated from corals, which have been described as potential anti-inflammatory molecules. PMID:26538822

  9. Honey: A Potential Therapeutic Agent for Managing Diabetic Wounds

    PubMed Central

    Islam, Md. Asiful; Gan, Siew Hua; Khalil, Md. Ibrahim

    2014-01-01

    Diabetic wounds are unlike typical wounds in that they are slower to heal, making treatment with conventional topical medications an uphill process. Among several different alternative therapies, honey is an effective choice because it provides comparatively rapid wound healing. Although honey has been used as an alternative medicine for wound healing since ancient times, the application of honey to diabetic wounds has only recently been revived. Because honey has some unique natural features as a wound healer, it works even more effectively on diabetic wounds than on normal wounds. In addition, honey is known as an “all in one” remedy for diabetic wound healing because it can combat many microorganisms that are involved in the wound process and because it possesses antioxidant activity and controls inflammation. In this review, the potential role of honey's antibacterial activity on diabetic wound-related microorganisms and honey's clinical effectiveness in treating diabetic wounds based on the most recent studies is described. Additionally, ways in which honey can be used as a safer, faster, and effective healing agent for diabetic wounds in comparison with other synthetic medications in terms of microbial resistance and treatment costs are also described to support its traditional claims. PMID:25386217

  10. Astaxanthin: a potential therapeutic agent in cardiovascular disease.

    PubMed

    Fassett, Robert G; Coombes, Jeff S

    2011-01-01

    Astaxanthin is a xanthophyll carotenoid present in microalgae, fungi, complex plants, seafood, flamingos and quail. It is an antioxidant with anti-inflammatory properties and as such has potential as a therapeutic agent in atherosclerotic cardiovascular disease. Synthetic forms of astaxanthin have been manufactured. The safety, bioavailability and effects of astaxanthin on oxidative stress and inflammation that have relevance to the pathophysiology of atherosclerotic cardiovascular disease, have been assessed in a small number of clinical studies. No adverse events have been reported and there is evidence of a reduction in biomarkers of oxidative stress and inflammation with astaxanthin administration. Experimental studies in several species using an ischaemia-reperfusion myocardial model demonstrated that astaxanthin protects the myocardium when administered both orally or intravenously prior to the induction of the ischaemic event. At this stage we do not know whether astaxanthin is of benefit when administered after a cardiovascular event and no clinical cardiovascular studies in humans have been completed and/or reported. Cardiovascular clinical trials are warranted based on the physicochemical and antioxidant properties, the safety profile and preliminary experimental cardiovascular studies of astaxanthin.

  11. Potential of Biological Agents in Decontamination of Agricultural Soil

    PubMed Central

    Javaid, Muhammad Kashif; Ashiq, Mehrban; Tahir, Muhammad

    2016-01-01

    Pesticides are widely used for the control of weeds, diseases, and pests of cultivated plants all over the world, mainly since the period after the Second World War. The use of pesticides is very extensive to control harm of pests all over the globe. Persistent nature of most of the synthetic pesticides causes serious environmental concerns. Decontamination of these hazardous chemicals is very essential. This review paper elaborates the potential of various biological agents in decontamination of agricultural soils. The agricultural crop fields are contaminated by the periodic applications of pesticides. Biodegradation is an ecofriendly, cost-effective, highly efficient approach compared to the physical and chemical methods which are expensive as well as unfriendly towards environment. Biodegradation is sensitive to the concentration levels of hydrogen peroxide and nitrogen along with microbial community, temperature, and pH changes. Experimental work for optimum conditions at lab scale can provide very fruitful results about specific bacterial, fungal strains. This study revealed an upper hand of bioremediation over physicochemical approaches. Further studies should be carried out to understand mechanisms of biotransformation. PMID:27293964

  12. Potential of Biological Agents in Decontamination of Agricultural Soil.

    PubMed

    Javaid, Muhammad Kashif; Ashiq, Mehrban; Tahir, Muhammad

    2016-01-01

    Pesticides are widely used for the control of weeds, diseases, and pests of cultivated plants all over the world, mainly since the period after the Second World War. The use of pesticides is very extensive to control harm of pests all over the globe. Persistent nature of most of the synthetic pesticides causes serious environmental concerns. Decontamination of these hazardous chemicals is very essential. This review paper elaborates the potential of various biological agents in decontamination of agricultural soils. The agricultural crop fields are contaminated by the periodic applications of pesticides. Biodegradation is an ecofriendly, cost-effective, highly efficient approach compared to the physical and chemical methods which are expensive as well as unfriendly towards environment. Biodegradation is sensitive to the concentration levels of hydrogen peroxide and nitrogen along with microbial community, temperature, and pH changes. Experimental work for optimum conditions at lab scale can provide very fruitful results about specific bacterial, fungal strains. This study revealed an upper hand of bioremediation over physicochemical approaches. Further studies should be carried out to understand mechanisms of biotransformation. PMID:27293964

  13. What magnitude are observed non-target impacts from weed biocontrol?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A systematic review focused by plant on non-target impacts from agents deliberately introduced for the biological control of weeds found significant non-target impacts to be rare. The magnitude of direct impact of 43 biocontrol agents on 140 non-target plants was retrospectively categorized using a ...

  14. Potential clinical application of interleukin-27 as an antitumor agent.

    PubMed

    Yoshimoto, Takayuki; Chiba, Yukino; Furusawa, Jun-Ichi; Xu, Mingli; Tsunoda, Ren; Higuchi, Kaname; Mizoguchi, Izuru

    2015-09-01

    Cancer immunotherapies such as sipuleucel-T and ipilimumab are promising new treatments that harness the power of the immune system to fight cancer and achieve long-lasting remission. Interleukin (IL)-27, a member of the IL-12 heterodimeric cytokine family, has pleiotropic functions in the regulation of immune responses with both pro-inflammatory and anti-inflammatory properties. Evidence obtained using a variety of preclinical mouse models indicates that IL-27 possesses potent antitumor activity against various types of tumors through multiple mechanisms without apparent adverse effects. These mechanisms include those mediated not only by CD8(+) T cells, natural killer cells and macrophages, but also by antibody-dependent cell-mediated cytotoxicity, antiangiogenesis, direct antiproliferative effects, inhibition of expression of cyclooxygenase-2 and prostaglandin E2 , and suppression of epithelial-mesenchymal transition, depending on the characteristics of individual tumors. However, the endogenous role of IL-27 subunits and one of its receptor subunits, WSX-1, in the susceptibility to tumor development after transplantation of tumor cell lines or endogenously arising tumors seems to be more complicated. IL-27 functions as a double-edged sword: IL-27 increases IL-10 production and the expression of programmed death ligand 1 and T-cell immunoglobulin and mucin domain-3, and promotes the generation of regulatory T cells, and IL-27 receptor α singling enhances transformation; IL-27 may augment protumor effects as well. Here, we review both facets of IL-27, antitumor effects and protumor effects, and discuss the potential clinical application of IL-27 as an antitumor agent.

  15. Disulfiram Attenuates Osteoclast Differentiation In Vitro: A Potential Antiresorptive Agent

    PubMed Central

    Cheng, Tak S.; Pavlos, Nathan J.; Rea, Sarah; Dai, Kerong; Zheng, Ming H.

    2015-01-01

    Disulfiram (DSF), a cysteine modifying compound, has long been clinically employed for the treatment of alcohol addiction. Mechanistically, DSF acts as a modulator of MAPK and NF-κB pathways signaling pathways. While these pathways are crucial for osteoclast (OC) differentiation, the potential influence of DSF on OC formation and function has not been directly assessed. Here, we explore the pharmacological effects of DSF on OC differentiation, activity and the modulation of osteoclastogenic signaling cascades. We first analyzed cytotoxicity of DSF on bone marrow monocytes isolated from C57BL/6J mice. Upon the establishment of optimal dosage, we conducted osteoclastogenesis and bone resorption assays in the presence or absence of DSF treatment. Luciferase assays in RAW264.7 cells were used to examine the effects of DSF on major transcription factors activation. Western blot, reverse transcription polymerase chain reaction, intracellular acidification and proton influx assays were employed to further dissect the underlying mechanism. DSF treatment dose-dependently inhibited both mouse and human osteoclastogenesis, especially at early stages of differentiation. This inhibition correlated with a decrease in the expression of key osteoclastic marker genes including CtsK, TRAP, DC-STAMP and Atp6v0d2 as well as a reduction in bone resorption in vitro. Suppression of OC differentiation was found to be due, at least in part, to the blockade of several key receptor activators of nuclear factor kappa-B ligand (RANKL)-signaling pathways including ERK, NF-κB and NFATc1. On the other hand, DSF failed to suppress intracellular acidification and proton influx in mouse and human osteoclasts using acridine orange quenching and microsome-based proton transport assays. Our findings indicate that DSF attenuates OC differentiation via the collective suppression of several key RANKL-mediated signaling cascades, thus making it an attractive agent for the treatment of OC

  16. Biofertilization and Biocontrol in the fight against soilborne fungal root pathogens in Australian soils

    NASA Astrophysics Data System (ADS)

    Cooper, Sarah; Agnew, Linda; Pereg, Lily

    2015-04-01

    Control of soilborne fungal root pathogens that severely compromise cotton production and other crops worldwide has historically been through the use of synthetic fungicides and fertilizers, these often have hazardous implications for environmental and soil health. The search for sustainable alternatives has lead to heightened interest in biocontrol, using soil microorganisms that suppress the growth of phytopathogens directly and biofertilization, the use of microorganisms to increasing the nutrient availability in soils, increasing seedling vigour. Soil properties and consequently soil microbial properties are strongly impacted by agricultural practices, therefore we are isolating indigenous microorganisms from soils collected from ten different geographical locations within the Australian cotton-growing region. These differ vastly in soil type and management practices. Soils are being analysed to compare the abundance of phosphate solubilising, auxin producing and nitrogen cycling bacteria. Rhizospheric bacteria capable of plant growth promoting through a multiple actions are being isolated. In addition, a method for isolating soilborne fungal suppressive microbes directly from soil samples has been designed and is currently being used. Comparisons between agricultural practices and the plant growth promoting microbial component of soil microbiome will be reported on. We will discuss the microbial isolates identified, their modes of action and their potential use as biocontrol agents and/or biofertilizers in Australian cotton growing soils.

  17. Francisella tularensis as a potential agent of bioterrorism?

    PubMed

    Maurin, Max

    2015-02-01

    Francisella tularensis is a category A bioterrorism agent. It is the etiological agent of tularemia, a zoonotic disease found throughout the northern hemisphere. The intentional spread of F. tularensis aerosols would probably lead to severe and often fatal pneumonia cases, but also secondary cases from contaminated animals and environments. We are not ready to face such a situation. No vaccine is currently available. A few antibiotics are active against F. tularensis, but strains resistant to these antibiotics could be used in the context of bioterrorism. We need new therapeutic strategies to fight against category A bioterrorism agents, including development of new drugs inhibiting F. tularensis growth and/or virulence, or enhancing the host response to infection by this pathogen.

  18. Diamondback moth in Ukraine: current status and potential for use biological control agents.

    PubMed

    Likar, Y; Stefanovska, T

    2009-01-01

    The Diamondback moth (DBM), Plutella xillostella (Linnaeus) (Lepidoptera: Plutellidae) is the insect pest damaging cabbage in Ukraine, especially in the Southern region. Biology, damage, population dynamics of diamondback moth and effect of natural enemies on the level of infestation of this pest by parasitoids and pathogens were studied in 2004-2007 in the laboratory and field conditions. Obtained results show that in general the pest has 2-3 generations, although up to 5-6 can evolve in the South. Fecundity and life longevity of Diamondback were studied on white cabbage, red cabbage, broccoli, cauliflower and two basic weeds: shepherd's purse and wild mustard. The host plant affects fecundity and life span of the diamondback moth. Fecundity differs significantly and is highest with white cabbage. Fauna of Diamondback moth parasitoids is quite rich. All stages are affected by numerous parasitoids and predators. Around 22 parasitoid species were recorded during the study. Overall parasitism ranged from 18% to 60% varying essentially between the areas. Apanteles (Cotesia) sp., Diadegma sp., Trichogramma sp. were most common in all areas. Steinernema sp., entomopathogenic nematodes are found to be natural enemies of diamondback moth. The range of natural enemies contributes significantly to the control of Diamondback moth. Conservation and augmentation of natural enemies should be used in IPM systems in order to control diamondback moth on cabbage. Entomopathogenic nematodes are prominent biocontrol agents.

  19. Physiological characteristics of the biocontrol yeast Pichia anomala J121.

    PubMed

    Fredlund, Elisabeth; Druvefors, Ulrika; Boysen, Marianne E; Lingsten, Karl-Johan; Schnürer, Johan

    2002-08-01

    The yeast Pichia anomala J121 prevents mold spoilage and enhances preservation of moist grain in malfunctioning storage systems. Development of P. anomala J121 as a biocontrol agent requires in-depth knowledge about its physiology. P. anomala J121 grew under strictly anaerobic conditions, at temperatures between 3 degrees C and 37 degrees C, at pH values between 2.0 and 12.4, and at a water activity of 0.92 (NaCl) and 0.85 (glycerol). It could assimilate a wide range of C- and N-sources and produce killer toxin. A selective medium containing starch, nitrate, acetic acid, and chloramphenicol was developed for P. anomala. P. anomala was equally sensitive as Candida albicans to common antifungal compounds. Growth ability at a range of environmental conditions contributes to the competitive ability of the biocontrol yeast P. anomala J121. PMID:12702290

  20. Occupational exposures to potentially hazardous agents in the petroleum industry

    SciTech Connect

    Runion, H.E.

    1988-07-01

    This chapter has been created to acquaint the reader with occupational exposures that are more common in, and somewhat unique to, the petroleum industry. Both highly toxic materials capable of causing acute illness or even death following short-term exposure, and chemical and physical agents that pose risk of chronic and irreversible damage to health during prolonged exposure are addressed.

  1. Generalist-feeding subterranean mites as potential biological control agents of immature corn rootworms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predatory mites are important components of subterranean food webs and may help regulate densities of agricultural pests, including western corn rootworms (Chrysomelidae: Diabrotica virgifera virgifera). Implementing conservation and/or classical biocontrol tactics could enhance densities of special...

  2. Nontarget herbivory by a weed biocontrol insect is limited to spillover, reducing the chance of population-level impacts.

    PubMed

    Catton, Haley A; Lalonde, Robert G; De Clerck-Floate, Rosemarie A

    2015-03-01

    Insects approved for classical biocontrol of weeds are often capable of using close relatives of their target weed for feeding, oviposition, or larval development, with reduced preference and performance. When nontarget herbivory occurs and is suspected to reduce survival, growth, or fecundity of individual plants, and insects are capable of reproducing on their nontarget host, characterization of spatial and temporal patterns of the occurrence and intensity of herbivory is valuable for predicting potential population-level effects. Here, we perform a novel post-release manipulative field experiment with a root-feeding biocontrol weevil, Mogulones crucifer, released in Canada to control the rangeland weed Cynoglossum officinale, to test for its ability to establish on the nontarget plant Hackelia micrantha. After Cynoglossum, M. crucifer exhibits its highest preference for and performance on Hackelia spp. We released M. crucifer on Canadian rangeland sites with naturally occurring populations of H. micrantha growing interspersed with the target weed or in the near absence of the target weed. Adult weevil feeding on surrounding plants was monitored for three summers after release (years 0, 1, and 2), and, subsequently, subsets of plants were destructively sampled to determine M. crucifer oviposition levels. Additional oviposition and larval development data were obtained from seven non-experimental sites where weevils were released zero, three, or four years earlier. M. crucifer was not detected on experimental sites without C. officinale after two years, and nontarget herbivory was restricted to rare, low-level spillover. Visible evidence of adult herbivory (i.e., scars on shoots) was associated with oviposition in 90% of targets but only 30% of nontarget plants. We infer, through ecological refuge theory, that nontarget population-level impacts from M. crucifer spillover are unlikely because of temporal, spatial, and probabilistic refuges from herbivory, and make

  3. Antioxidants: potential antiviral agents for Japanese encephalitis virus infection.

    PubMed

    Zhang, Yu; Wang, Zehua; Chen, Huan; Chen, Zongtao; Tian, Yanping

    2014-07-01

    Japanese encephalitis (JE) is prevalent throughout eastern and southern Asia and the Pacific Rim. It is caused by the JE virus (JEV), which belongs to the family Flaviviridae. Despite the importance of JE, little is known about its pathogenesis. The role of oxidative stress in the pathogenesis of viral infections has led to increased interest in its role in JEV infections. This review focuses mainly on the role of oxidative stress in the pathogenesis of JEV infection and the antiviral effect of antioxidant agents in inhibiting JEV production. First, this review summarizes the pathogenesis of JE. The pathological changes include neuronal death, astrocyte activation, and microglial proliferation. Second, the relationship between oxidative stress and JEV infection is explored. JEV infection induces the generation of oxidants and exhausts the supply of antioxidants, which activates specific signaling pathways. Finally, the therapeutic efficacy of a variety of antioxidants as antiviral agents, including minocycline, arctigenin, fenofibrate, and curcumin, was studied. In conclusion, antioxidants are likely to be developed into antiviral agents for the treatment of JE. PMID:24780919

  4. Pseudomonas fluorescens F113 mutant with enhanced competitive colonization ability and improved biocontrol activity against fungal root pathogens.

    PubMed

    Barahona, Emma; Navazo, Ana; Martínez-Granero, Francisco; Zea-Bonilla, Teresa; Pérez-Jiménez, Rosa María; Martín, Marta; Rivilla, Rafael

    2011-08-01

    Motility is one of the most important traits for efficient rhizosphere colonization by Pseudomonas fluorescens F113rif (F113). In this bacterium, motility is a polygenic trait that is repressed by at least three independent pathways, including the Gac posttranscriptional system, the Wsp chemotaxis-like pathway, and the SadB pathway. Here we show that the kinB gene, which encodes a signal transduction protein that together with AlgB has been implicated in alginate production, participates in swimming motility repression through the Gac pathway, acting downstream of the GacAS two-component system. Gac mutants are impaired in secondary metabolite production and are unsuitable as biocontrol agents. However, the kinB mutant and a triple mutant affected in kinB, sadB, and wspR (KSW) possess a wild-type phenotype for secondary metabolism. The KSW strain is hypermotile and more competitive for rhizosphere colonization than the wild-type strain. We have compared the biocontrol activity of KSW with those of the wild-type strain and a phenotypic variant (F113v35 [V35]) which is hypermotile and hypercompetitive but is affected in secondary metabolism since it harbors a gacS mutation. Biocontrol experiments in the Fusarium oxysporum f. sp. radicis-lycopersici/Lycopersicum esculentum (tomato) and Phytophthora cactorum/Fragaria vesca (strawberry) pathosystems have shown that the three strains possess biocontrol activity. Biocontrol activity was consistently lower for V35, indicating that the production of secondary metabolites was the most important trait for biocontrol. Strain KSW showed improved biocontrol compared with the wild-type strain, indicating that an increase in competitive colonization ability resulted in improved biocontrol and that the rational design of biocontrol agents by mutation is feasible. PMID:21685161

  5. Microtubule-Stabilizing Agents as Potential Therapeutics for Neurodegenerative Disease

    PubMed Central

    Brunden, Kurt R.; Trojanowski, John Q.; Smith, Amos B.; Lee, Virginia M.-Y.; Ballatore, Carlo

    2014-01-01

    Microtubules (MTs)1, cytoskeletal elements found in all mammalian cells, play a significant role in cell structure and in cell division. They are especially critical in the proper functioning of post-mitotic central nervous system neurons, where MTs serve as the structures on which key cellular constituents are trafficked in axonal projections. MTs are stabilized in axons by the MT-associated protein tau, and in several neurodegenerative diseases, including Alzheimer’s disease, frontotemporal lobar degeneration, and Parkinson’s disease, tau function appears to be compromised due to the protein dissociating from MTs and depositing into insoluble inclusions referred to as neurofibrillary tangles. This loss of tau function is believed to result in alterations of MT structure and function, resulting in aberrant axonal transport that likely contributes to the neurodegenerative process. There is also evidence of axonal transport deficiencies in other neurodegenerative diseases, including amyotrophic lateral sclerosis and Huntington’s disease, which may result, at least in part, from MT alterations. Accordingly, a possible therapeutic strategy for such neurodegenerative conditions is to treat with MT-stabilizing agents, such as those that have been used in the treatment of cancer. Here, we review evidence of axonal transport and MT deficiencies in a number of neurodegenerative diseases, and summarize the various classes of known MT-stabilizing agents. Finally, we highlight the growing evidence that small molecule MT-stabilizing agents provide benefit in animal models of neurodegenerative disease and discuss the desired features of such molecules for the treatment of these central nervous system disorders. PMID:24433963

  6. Investigation of Vietnamese plants for potential anticancer agents

    PubMed Central

    Pérez, Lynette Bueno; Still, Patrick C.; Naman, C. Benjamin; Ren, Yulin; Pan, Li; Chai, Hee-Byung; Carcache de Blanco, Esperanza J.; Ninh, Tran Ngoc; Van Thanh, Bui; Swanson, Steven M.; Soejarto, Djaja D.

    2014-01-01

    Higher plants continue to afford humankind with many new drugs, for a variety of disease types. In this review, recent phytochemical and biological progress is presented for part of a collaborative multi-institutional project directed towards the discovery of new antitumor agents. The specific focus is on bioactive natural products isolated and characterized structurally from tropical plants collected in Vietnam. The plant collection, identification, and processing steps are described, and the natural products isolated from these species are summarized with their biological activities. PMID:25395897

  7. Potential for laboratory exposures to biohazardous agents found in blood.

    PubMed Central

    Evans, M R; Henderson, D K; Bennett, J E

    1990-01-01

    The magnitude of risk for occupational exposures to biohazardous agents found in blood was assessed by 800 environmental samples taken from a total of 10 clinical and research laboratories at the National Institutes of Health (NIH). Thirty-one samples from 11 work stations in three laboratories contained hepatitis B virus surface antigen (HBsAg). Observations of workers indicated that environmental contamination arose from several sources. Among the 11 work stations with HBsAg environmental samples, eight had high work loads, seven had inappropriate behaviors, and nine had flawed laboratory techniques. This information suggests that a multifactorial approach is needed to minimize the risk of laboratory-associated infections. PMID:2316762

  8. Monocarboxylate Transporter 1 Inhibitors as Potential Anticancer Agents

    PubMed Central

    2015-01-01

    Potent monocarboxylate transporter 1 inhibitors (MCT1) have been developed based on α-cyano-4-hydroxycinnamic acid template. Structure–activity relationship studies demonstrate that the introduction of p-N, N-dialkyl/diaryl, and o-methoxy groups into cyanocinnamic acid has maximal MCT1 inhibitory activity. Systemic toxicity studies in healthy ICR mice with few potent MCT1 inhibitors indicate normal body weight gains in treated animals. In vivo tumor growth inhibition studies in colorectal adenocarcinoma (WiDr cell line) in nude mice xenograft models establish that compound 27 exhibits single agent activity in inhibiting the tumor growth. PMID:26005533

  9. Surfactin triggers biofilm formation of Bacillus subtilis in melon phylloplane and contributes to the biocontrol activity.

    PubMed

    Zeriouh, Houda; de Vicente, Antonio; Pérez-García, Alejandro; Romero, Diego

    2014-07-01

    The biocontrol activity of many Bacillus species has been traditionally related to the direct antagonism of pathogens. In previous works, we reported that B. subtilis strain UMAF6614 was an efficient biocontrol agent that produced bacillomycin, fengycin and surfactin lipopeptides. Bacillomycins and fengycins were shown to have antagonistic activity towards fungal and bacterial pathogens of cucurbits; however, the functionality of surfactin remained unclear. In this study, the role of surfactin in the biocontrol activity of this strain was investigated. We observed that a deficiency in surfactin production led to a partial reduction of disease suppression by this biocontrol agent, which coincided with a defect in biofilm formation and the colonization of the melon phylloplane. These effects were due to a dramatic reduction in the production of exopolysaccharide and the TasA protein, which are the two major components of the extracellular matrix. We propose that the biocontrol activity of this strain is the result of the coordinated action of the three families of lipopeptides. B. subtilis UMAF6614 produces surfactin to trigger biofilm formation on melon phylloplane, which ensures the long-term persistence and the adequate secretion of suppressive lipopeptides, bacillomycins and fengycins, which efficiently target pathogens.

  10. Killer activity of Saccharomyces cerevisiae strains: partial characterization and strategies to improve the biocontrol efficacy in winemaking.

    PubMed

    de Ullivarri, Miguel Fernández; Mendoza, Lucía M; Raya, Raúl R

    2014-11-01

    Killer yeasts are considered potential biocontrol agents to avoid or reduce wine spoilage by undesirable species. In this study two Saccharomyces cerevisiae strains (Cf8 and M12) producing killer toxin were partially characterized and new strategies to improve their activity in winemaking were evaluated. Killer toxins were characterized by biochemical tests and growth inhibition of sensitive yeasts. Also genes encoding killer toxin were detected in the chromosomes of both strains by PCR. Both toxins showed optimal activity and production at conditions used during the wine-making process (pH 3.5 and temperatures of 15-25 °C). In addition, production of both toxins was higher when a nitrogen source was added. To improve killer activity different strategies of inoculation were studied, with the sequential inoculation of killer strains the best combination to control the growth of undesired yeasts. Sequential inoculation of Cf8-M12 showed a 45 % increase of killer activity on sensitive S. cerevisiae and spoilage yeasts. In the presence of ethanol (5-12 %) and SO2 (50 mg/L) the killer activity of both toxins was increased, especially for toxin Cf8. Characteristics of both killer strains support their future application as starter cultures and biocontrol agents to produce wines of controlled quality.

  11. Intracellular trehalose and sorbitol synergistically promoting cell viability of a biocontrol yeast, Pichia anomala, for aflatoxin reduction.

    PubMed

    Hua, Sui Sheng T; Hernlem, Bradley J; Yokoyama, Wallace; Sarreal, Siov Bouy L

    2015-05-01

    Pichia anomala (Wickerhamomyces anomalus) WRL-076 was discovered by a visual screening bioassay for its antagonism against Aspergillus flavus. The yeast was shown to significantly inhibit aflatoxin production and the growth of A. flavus. P. anomala is a potential biocontrol agent for reduction of aflatoxin in the food chain. Maintaining the viability of biocontrol agents in formulated products is a great challenge for commercial applications. Four media, NYG, NYGS, NYGT and NYGST are described which support good growth of yeast cells and were tested as storage formulations. Post growth supplement of 5 % trehalose to NYGST resulted in 83 % viable yeast cells after 12 months in cold storage. Intracellular sorbitol and trehalose concentrations were determined by HPLC analysis at the beginning of the storage and at the end of 12 month. Correlation of cell viability to both trehalose and sorbitol suggested a synergistic effect. Bonferroni (Dunn) t Test, Tukey's Studentized Range (HSD) Test and Duncan's Multiple Range Test, all showed that yeast cell viability in samples with both intracellular trehalose and sorbitol were significantly higher than those with either or none, at a 95 % confidence level. DiBAC4(5) and CFDA-AM were used as the membrane integrity fluorescent stains to create a two-color vital staining scheme with red and green fluorescence, respectively. Yeast cells stored in formulations NYG and NYGS with no detectable trehalose, displayed mostly red fluorescence. Yeast cells in NYGST+5T showed mostly green fluorescence. PMID:25700743

  12. Intracellular trehalose and sorbitol synergistically promoting cell viability of a biocontrol yeast, Pichia anomala, for aflatoxin reduction.

    PubMed

    Hua, Sui Sheng T; Hernlem, Bradley J; Yokoyama, Wallace; Sarreal, Siov Bouy L

    2015-05-01

    Pichia anomala (Wickerhamomyces anomalus) WRL-076 was discovered by a visual screening bioassay for its antagonism against Aspergillus flavus. The yeast was shown to significantly inhibit aflatoxin production and the growth of A. flavus. P. anomala is a potential biocontrol agent for reduction of aflatoxin in the food chain. Maintaining the viability of biocontrol agents in formulated products is a great challenge for commercial applications. Four media, NYG, NYGS, NYGT and NYGST are described which support good growth of yeast cells and were tested as storage formulations. Post growth supplement of 5 % trehalose to NYGST resulted in 83 % viable yeast cells after 12 months in cold storage. Intracellular sorbitol and trehalose concentrations were determined by HPLC analysis at the beginning of the storage and at the end of 12 month. Correlation of cell viability to both trehalose and sorbitol suggested a synergistic effect. Bonferroni (Dunn) t Test, Tukey's Studentized Range (HSD) Test and Duncan's Multiple Range Test, all showed that yeast cell viability in samples with both intracellular trehalose and sorbitol were significantly higher than those with either or none, at a 95 % confidence level. DiBAC4(5) and CFDA-AM were used as the membrane integrity fluorescent stains to create a two-color vital staining scheme with red and green fluorescence, respectively. Yeast cells stored in formulations NYG and NYGS with no detectable trehalose, displayed mostly red fluorescence. Yeast cells in NYGST+5T showed mostly green fluorescence.

  13. Pyrazoles as potential anti-angiogenesis agents: a contemporary overview

    PubMed Central

    Kasiotis, Konstantinos M.; Tzanetou, Evangelia N.; Haroutounian, Serkos A.

    2014-01-01

    Angiogenesis is a mulit-step process by which new blood vessels are formed from preexisting vasculature. It is a key rate limiting factor in tumor growth since new blood vessels are necessary to increase tumor size. In this context it has been shown that anti-angiogenic factors can be used in cancer therapy. Among the plethora of heterocyclic compounds administered as anti-angiogenesis agents, pyrazoles constitute one of the bottlenecks of this category. Currently, several pyrazole based compounds are administered or are in Phase II and III trials and new targets emerge. It is highly possible that the advent of the next two decades will lead to the discovery and use of additional pyrazoles whose anti-angiogenic profile will position them in the forefront of the battle of various malignancies. The present review is an attempt to focus on those pyrazoles that arise as anti-angiogenesis agents commenting both on the chemistry and bioactivity that these exhibit aiming to contribute to the perspectives that they hold for future research. PMID:25250310

  14. Pyrazoles as potential anti-angiogenesis agents: A contemporary overview

    NASA Astrophysics Data System (ADS)

    Kasiotis, Konstantinos; Tzanetou, Evangelia; Haroutounian, Serkos

    2014-09-01

    Angiogenesis is a mulit-step process by which new blood vessels are formed from preexisting vasculature. It is a key rate limiting factor in tumor growth since new blood vessels are necessary to increase tumor size. In this context it has been shown that anti-angiogenic factors can be used in cancer therapy. Among the plethora of heterocyclic compounds administered as anti-angiogenesis agents, pyrazoles constitute one of the bottlenecks of this category. Currently several pyrazole based compounds are administered or are in Phase II and III trials and new targets emerge. It is highly possible that the advent of the next two decades will lead to the discovery and use of additional pyrazoles whose anti-angiogenic profile will position them in the forefront of the battle of various malignancies. The present review is an attempt to focus on those pyrazoles that arise as anti-angiogenesis agents commenting both on the chemistry and bioactivity that these exhibit aiming to contribute to the perspectives that they hold for future research.

  15. Quinine conjugates and quinine analogues as potential antimalarial agents.

    PubMed

    Jones, Rachel A; Panda, Siva S; Hall, C Dennis

    2015-06-01

    Malaria is a tropical disease, prevalent in Southeast Asia and Africa, resulting in over half a million deaths annually; efforts to develop new antimalarial agents are therefore particularly important. Quinine continues to play a role in the fight against malaria, but quinoline derivatives are more widely used. Drugs based on the quinoline scaffold include chloroquine and primaquine, which are able to act against the blood and liver stages of the parasite's life cycle. The purpose of this review is to discuss reported biologically active compounds based on either the quinine or quinoline scaffold that may have enhanced antimalarial activity. The review emphasises hybrid molecules, and covers advances made in the last five years. The review is divided into three sections: modifications to the quinine scaffold, modifications to aminoquinolines and finally metal-containing antimalarial compounds.

  16. Therapeutic Potential of Hydrazones as Anti-Inflammatory Agents

    PubMed Central

    Bala, Suman; Sharma, Neha; Saini, Vipin

    2014-01-01

    Hydrazones are a special class of organic compounds in the Schiff base family. Hydrazones constitute a versatile compound of organic class having basic structure (R1R2C=NNR3R4). The active centers of hydrazone, that is, carbon and nitrogen, are mainly responsible for the physical and chemical properties of the hydrazones and, due to the reactivity toward electrophiles and nucleophiles, hydrazones are used for the synthesis of organic compound such as heterocyclic compounds with a variety of biological activities. Hydrazones and their derivatives are known to exhibit a wide range of interesting biological activities like antioxidant, anti-inflammatory, anticonvulsant, analgesic, antimicrobial, anticancer, antiprotozoal, antioxidant, antiparasitic, antiplatelet, cardioprotective, anthelmintic, antidiabetic, antitubercular, trypanocidal, anti-HIV, and so forth. The present review summarizes the efficiency of hydrazones as potent anti-inflammatory agents. PMID:25383223

  17. Biological agents with potential for misuse: a historical perspective and defensive measures.

    PubMed

    Bhalla, Deepak K; Warheit, David B

    2004-08-15

    Biological and chemical agents capable of producing serious illness or mortality have been used in biowarfare from ancient times. Use of these agents has progressed from crude forms in early and middle ages, when snakes and infected cadavers were used as weapons in battles, to sophisticated preparations for use during and after the second World War. Cults and terrorist organizations have attempted the use of biological agents with an aim to immobilize populations or cause serious harm. The reasons for interest in these agents by individuals and organizations include relative ease of acquisition, potential for causing mass casualty or panic, modest financing requirement, availability of technology, and relative ease of delivery. The Centers for Disease Control and Prevention has classified Critical Biological Agents into three major categories. This classification was based on several criteria, which include severity of impact on human health, potential for delivery in a weapon, capacity to cause panic and special needs for development, and stockpiling of medication. Agents that could cause the greatest harm following deliberate use were placed in category A. Category B included agents capable of producing serious harm and significant mortality but of lower magnitude than category A agents. Category C included emerging pathogens that could be developed for mass dispersion in future and their potential as a major health threat. A brief description of the category A bioagents is included and the pathophysiology of two particularly prominent agents, namely anthrax and smallpox, is discussed in detail. The potential danger from biological agents and their ever increasing threat to human populations have created a need for developing technologies for their early detection, for developing treatment strategies, and for refinement of procedures to ensure survival of affected individuals so as to attain the ultimate goal of eliminating the threat from intentional use of

  18. Testing the efficacy of eGFP-transformed Aspergillus flavus as biocontrol strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current biological control methods to prevent pre-harvest aflatoxin contamination of corn, cottonseed, and ground and tree nuts involve field inoculation of non-aflatoxigenic Aspergillus flavus. To date, the efficacy of this approach requires annual reapplication of the biocontrol agent. The reason ...

  19. Biocontrol attack exacerbates pollen-limitation in the invasive plant Centaurea solstitialis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollen-limited seed set is rarely studied in invasive plants despite the fact that >50% of the most problematic invaders in North America are pollinator-dependent. Further, pollinators are rarely considered in the use biocontrol agents to manage invaders. The ecological literature shows that herbivo...

  20. Potential Role of Garcinol as an Anticancer Agent

    PubMed Central

    Saadat, Nadia; Gupta, Smiti V.

    2012-01-01

    Garcinol, a polyisoprenylated benzophenone, is extracted from the rind of the fruit of Garcinia indica, a plant found extensively in tropical regions. Although the fruit has been consumed traditionally over centuries, its biological activities, specifically its anticancer potential is a result of recent scientific investigations. The anticarcinogenic properties of garcinol appear to be moderated via its antioxidative, anti-inflammatory, antiangiogenic, and proapoptotic activities. In addition, garcinol displays effective epigenetic influence by inhibiting histone acetyltransferases (HAT 300) and by possible posttranscriptional modulation by mi RNA profiles involved in carcinogenesis. In vitro as well as some in vivo studies have shown the potential of this compound against several cancers types including breast, colon, pancreatic, and leukemia. Although this is a promising molecule in terms of its anticancer properties, investigations in relevant animal models, and subsequent human trials are warranted in order to fully appreciate and confirm its chemopreventative and/or therapeutic potential. PMID:22745638

  1. Neem components as potential agents for cancer prevention and treatment.

    PubMed

    Hao, Fang; Kumar, Sandeep; Yadav, Neelu; Chandra, Dhyan

    2014-08-01

    Azadirachta indica, also known as neem, is commonly found in many semi-tropical and tropical countries including India, Pakistan, and Bangladesh. The components extracted from neem plant have been used in traditional medicine for the cure of multiple diseases including cancer for centuries. The extracts of seeds, leaves, flowers, and fruits of neem have consistently shown chemopreventive and antitumor effects in different types of cancer. Azadirachtin and nimbolide are among the few bioactive components in neem that have been studied extensively, but research on a great number of additional bioactive components is warranted. The key anticancer effects of neem components on malignant cells include inhibition of cell proliferation, induction of cell death, suppression of cancer angiogenesis, restoration of cellular reduction/oxidation (redox) balance, and enhancement of the host immune responses against tumor cells. While the underlying mechanisms of these effects are mostly unclear, the suppression of NF-κB signaling pathway is, at least partially, involved in the anticancer functions of neem components. Importantly, the anti-proliferative and apoptosis-inducing effects of neem components are tumor selective as the effects on normal cells are significantly weaker. In addition, neem extracts sensitize cancer cells to immunotherapy and radiotherapy, and enhance the efficacy of certain cancer chemotherapeutic agents. This review summarizes the current updates on the anticancer effects of neem components and their possible impact on managing cancer incidence and treatment. PMID:25016141

  2. Neem components as potential agents for cancer prevention and treatment.

    PubMed

    Hao, Fang; Kumar, Sandeep; Yadav, Neelu; Chandra, Dhyan

    2014-08-01

    Azadirachta indica, also known as neem, is commonly found in many semi-tropical and tropical countries including India, Pakistan, and Bangladesh. The components extracted from neem plant have been used in traditional medicine for the cure of multiple diseases including cancer for centuries. The extracts of seeds, leaves, flowers, and fruits of neem have consistently shown chemopreventive and antitumor effects in different types of cancer. Azadirachtin and nimbolide are among the few bioactive components in neem that have been studied extensively, but research on a great number of additional bioactive components is warranted. The key anticancer effects of neem components on malignant cells include inhibition of cell proliferation, induction of cell death, suppression of cancer angiogenesis, restoration of cellular reduction/oxidation (redox) balance, and enhancement of the host immune responses against tumor cells. While the underlying mechanisms of these effects are mostly unclear, the suppression of NF-κB signaling pathway is, at least partially, involved in the anticancer functions of neem components. Importantly, the anti-proliferative and apoptosis-inducing effects of neem components are tumor selective as the effects on normal cells are significantly weaker. In addition, neem extracts sensitize cancer cells to immunotherapy and radiotherapy, and enhance the efficacy of certain cancer chemotherapeutic agents. This review summarizes the current updates on the anticancer effects of neem components and their possible impact on managing cancer incidence and treatment.

  3. Thymol and eugenol derivatives as potential antileishmanial agents.

    PubMed

    de Morais, Selene Maia; Vila-Nova, Nadja Soares; Bevilaqua, Claudia Maria Leal; Rondon, Fernanda Cristina; Lobo, Carlos Henrique; de Alencar Araripe Noronha Moura, Arlindo; Sales, Antônia Débora; Rodrigues, Ana Paula Ribeiro; de Figuereido, José Ricardo; Campello, Claudio Cabral; Wilson, Mary E; de Andrade, Heitor Franco

    2014-11-01

    In Northeastern Brazil visceral leishmaniasis is endemic with lethal cases among humans and dogs. Treatment is toxic and 5-10% of humans die despite treatment. The aim of this work was to survey natural active compounds to find new molecules with high activity and low toxicity against Leishmania infantum chagasi. The compounds thymol and eugenol were chosen to be starting compounds to synthesize acetyl and benzoyl derivatives and to test their antileishmanial activity in vitro and in vivo against L. i. chagasi. A screening assay using luciferase-expressing promastigotes was used to measure the growth inhibition of promastigotes, and an ELISA in situ was performed to evaluate the growth inhibition of amastigote. For the in vivo assay, thymol and eugenol derivatives were given IP to BALB/c mice at 100mg/kg/day for 30 days. The thymol derivatives demonstrated the greater activity than the eugenol derivatives, and benzoyl-thymol was the best inhibitor (8.67 ± 0.28 μg/mL). All compounds demonstrated similar activity against amastigotes, and acetyl-thymol was more active than thymol and the positive control drug amphotericin B. Immunohistochemistry demonstrated the presence of Leishmania amastigote only in the spleen but not the liver of mice treated with acetyl-thymol. Thus, these synthesized derivatives demonstrated anti-leishmanial activity both in vitro and in vivo. These may constitute useful compounds to generate new agents for treatment of leishmaniasis.

  4. Thymol and eugenol derivatives as potential antileishmanial agents.

    PubMed

    de Morais, Selene Maia; Vila-Nova, Nadja Soares; Bevilaqua, Claudia Maria Leal; Rondon, Fernanda Cristina; Lobo, Carlos Henrique; de Alencar Araripe Noronha Moura, Arlindo; Sales, Antônia Débora; Rodrigues, Ana Paula Ribeiro; de Figuereido, José Ricardo; Campello, Claudio Cabral; Wilson, Mary E; de Andrade, Heitor Franco

    2014-11-01

    In Northeastern Brazil visceral leishmaniasis is endemic with lethal cases among humans and dogs. Treatment is toxic and 5-10% of humans die despite treatment. The aim of this work was to survey natural active compounds to find new molecules with high activity and low toxicity against Leishmania infantum chagasi. The compounds thymol and eugenol were chosen to be starting compounds to synthesize acetyl and benzoyl derivatives and to test their antileishmanial activity in vitro and in vivo against L. i. chagasi. A screening assay using luciferase-expressing promastigotes was used to measure the growth inhibition of promastigotes, and an ELISA in situ was performed to evaluate the growth inhibition of amastigote. For the in vivo assay, thymol and eugenol derivatives were given IP to BALB/c mice at 100mg/kg/day for 30 days. The thymol derivatives demonstrated the greater activity than the eugenol derivatives, and benzoyl-thymol was the best inhibitor (8.67 ± 0.28 μg/mL). All compounds demonstrated similar activity against amastigotes, and acetyl-thymol was more active than thymol and the positive control drug amphotericin B. Immunohistochemistry demonstrated the presence of Leishmania amastigote only in the spleen but not the liver of mice treated with acetyl-thymol. Thus, these synthesized derivatives demonstrated anti-leishmanial activity both in vitro and in vivo. These may constitute useful compounds to generate new agents for treatment of leishmaniasis. PMID:25281268

  5. Neem components as potential agents for cancer prevention and treatment

    PubMed Central

    Hao, Fang; Kumar, Sandeep; Yadav, Neelu; Chandra, Dhyan

    2016-01-01

    Azadirachta indica, also known as neem, is commonly found in many semi-tropical and tropical countries including India, Pakistan, and Bangladesh. The components extracted from neem plant have been used in traditional medicine for the cure of multiple diseases including cancer for centuries. The extracts of seeds, leaves, flowers, and fruits of neem have consistently shown chemopreventive and antitumor effects in different types of cancer. Azadirachtin and nimbolide are among the few bioactive components in neem that have been studied extensively, but research on a great number of additional bioactive components is warranted. The key anticancer effects of neem components on malignant cells include inhibition of cell proliferation, induction of cell death, suppression of cancer angiogenesis, restoration of cellular reduction/oxidation (redox) balance, and enhancement of the host immune responses against tumor cells. While the underlying mechanisms of these effects are mostly unclear, the suppression of NF-κB signaling pathway is, at least partially, involved in the anticancer functions of neem components. Importantly, the anti-proliferative and apoptosis-inducing effects of neem components are tumor selective as the effects on normal cells are significantly weaker. In addition, neem extracts sensitize cancer cells to immunotherapy and radiotherapy, and enhance the efficacy of certain cancer chemotherapeutic agents. This review summarizes the current updates on the anticancer effects of neem components and their possible impact on managing cancer incidence and treatment. PMID:25016141

  6. Viruses as potential pathogenic agents in systemic lupus erythematosus.

    PubMed

    Nelson, P; Rylance, P; Roden, D; Trela, M; Tugnet, N

    2014-05-01

    Genetic and environmental factors appear to contribute to the pathogenesis of systemic lupus erythematosus (SLE). Viral infections have been reported to be associated with the disease. A number of exogenous viruses have been linked to the pathogenesis of SLE, of which Epstein-Barr virus (EBV) has the most evidence of an aetiological candidate. In addition, human endogenous retroviruses (HERV), HRES-1, ERV-3, HERV-E 4-1, HERV-K10 and HERV-K18 have also been implicated in SLE. HERVs are incorporated into human DNA, and thus can be inherited. HERVs may trigger an autoimmune reaction through molecular mimicry, since homology of amino acid sequences between HERV proteins and SLE autoantigens has been demonstrated. These viruses can also be influenced by oestrogen, DNA hypomethylation, and ultraviolet light (UVB) exposure which have been shown to enhance HERV activation or expression. Viral infection, or other environmental factors, could induce defective apoptosis, resulting in loss of immune tolerance. Further studies in SLE and other autoimmune diseases are needed to elucidate the contribution of both exogenous and endogenous viruses in the development of autoimmunity. If key peptide sequences could be identified as molecular mimics between viruses and autoantigens, then this might offer the possibility of the development of blocking peptides or antibodies as therapeutic agents in SLE and other autoimmune conditions.

  7. Yeasts from native Brazilian Cerrado plants: Occurrence, diversity and use in the biocontrol of citrus green mould.

    PubMed

    Sperandio, Eugenio Miranda; do Vale, Helson Mario Martins; Moreira, Geisianny Augusta Monteiro

    2015-11-01

    Yeasts are some of the most important postharvest biocontrol agents. Postharvest oranges frequently deteriorate due to green mould (Penicillium digitatum), which causes significant losses. The aims of this study were to determine the composition and diversity of yeasts on plants of the Brazilian Cerrado and to explore their potential for inhibiting citrus green mould. Leaves and fruit of Byrsonima crassifolia and Eugenia dysenterica were collected from Cerrado conservation areas, and thirty-five yeasts were isolated and identified by sequencing the D1-D2 domain of the rDNA large subunit (26S). The isolates represented the Aureobasidium, Meyerozyma, Candida, and Pichia genera. Three isolates identified as Aureobasidium pullulans exhibited potential for the control of P. digitatum in both in vitro and in vivo tests; these isolates reduced the incidence of disease and increased the storage time of fruit. Aureobasidium. pullulans has immense potential for the biological control of filamentous fungi.

  8. Yeasts from native Brazilian Cerrado plants: Occurrence, diversity and use in the biocontrol of citrus green mould.

    PubMed

    Sperandio, Eugenio Miranda; do Vale, Helson Mario Martins; Moreira, Geisianny Augusta Monteiro

    2015-11-01

    Yeasts are some of the most important postharvest biocontrol agents. Postharvest oranges frequently deteriorate due to green mould (Penicillium digitatum), which causes significant losses. The aims of this study were to determine the composition and diversity of yeasts on plants of the Brazilian Cerrado and to explore their potential for inhibiting citrus green mould. Leaves and fruit of Byrsonima crassifolia and Eugenia dysenterica were collected from Cerrado conservation areas, and thirty-five yeasts were isolated and identified by sequencing the D1-D2 domain of the rDNA large subunit (26S). The isolates represented the Aureobasidium, Meyerozyma, Candida, and Pichia genera. Three isolates identified as Aureobasidium pullulans exhibited potential for the control of P. digitatum in both in vitro and in vivo tests; these isolates reduced the incidence of disease and increased the storage time of fruit. Aureobasidium. pullulans has immense potential for the biological control of filamentous fungi. PMID:26466874

  9. In vitro biocontrol analysis of Alternaria alternata (Fr.) Keissler under different environmental conditions.

    PubMed

    Sempere, F; Santamarina, M P

    2007-03-01

    The species Trichoderma harzianum was analyzed as possible biocontrol agent of Alternaria alternata under different environmental conditions (water activity and temperature). The strains were analyzed macroscopically to obtain the Index of Dominance. The analysis was completed using two microscopic techniques. T. harzianum showed dominance on contact over A. alternata at all testing temperatures and water activities tested except at 0.95 a(w) and 15 degrees C, at which T. harzianum inhibited A. alternata at a distance. Biocontrol was governed by different mechanisms such as competition for space and nutrients, mycoparasitism, and possible antibiosis. Temperature and water activity significantly influenced fungal growth rate. PMID:17356789

  10. Interactions between conventional and organic farming for biocontrol services across the landscape.

    PubMed

    Bianchi, F J J A; Ives, A R; Schellhorn, N A

    2013-10-01

    While the area of organic crop production increases at a global scale, the potential interactions between pest management in organic and conventionally managed systems have so far received little attention. Here, we evaluate the landscape-level codependence of insecticide-based and natural enemy-based pest management using a simulation model for parasitoid-host interactions in landscapes consisting of conventionally and organically managed fields. In our simulations conventional management consists of broad-spectrum or selective insecticide application, while organic management involves no insecticides. Simulations indicate that insecticide use can easily result in lose-lose scenarios whereby both organically and conventionally managed fields suffer from increased pest loads as compared to a scenario where no insecticides are used, but that under some conditions insecticide use can be compatible with biocontrol. Simulations also suggest that the pathway to achieve the insecticide reduction without triggering additional pest pressure is not straightforward, because increasing the proportion of organically managed fields or reducing the spray frequency in conventional fields can potentially give rise to dramatic increases in pest load. The disruptive effect of insecticide use, however, can be mitigated by spatially clustering organic fields and using selective insecticides, although the effectiveness of this mitigation depends on the behavioral traits of the biocontrol agents. Poorly dispersing parasitoids and parasitoids with high attack rates required a lower amount of organically managed fields for effective pest suppression. Our findings show that the transition from a landscape dominated by conventionally managed crops to organic management has potential pitfalls; intermediate levels of organic management may lead to higher pest burdens than either low or high adoption of organic management.

  11. Copper-D-penicillamine complex as potential contrast agent for MRI.

    PubMed

    Kupka, T; Dziegielewski, J O; Pasterna, G; Małecki, J G

    1992-01-01

    In vitro and in vivo proton T1 data are reported that demonstrate that the paramagnetic copper-D-penicillamine complex can be applied as a potential contrast agent to magnetic resonance imaging. PMID:1461082

  12. Potential effects of cannabidiol as a wake-promoting agent.

    PubMed

    Murillo-Rodríguez, Eric; Sarro-Ramírez, Andrea; Sánchez, Daniel; Mijangos-Moreno, Stephanie; Tejeda-Padrón, Alma; Poot-Aké, Alwin; Guzmán, Khalil; Pacheco-Pantoja, Elda; Arias-Carrión, Oscar

    2014-05-01

    Over the last decades, the scientific interest in chemistry and pharmacology of cannabinoids has increased. Most attention has focused on ∆(9)-tetrahydrocannabinol (∆(9)-THC) as it is the psychoactive constituent of Cannabis sativa (C. sativa). However, in previous years, the focus of interest in the second plant constituent with non-psychotropic properties, cannabidiol (CBD) has been enhanced. Recently, several groups have investigated the pharmacological properties of CBD with significant findings; furthermore, this compound has raised promising pharmacological properties as a wake-inducing drug. In the current review, we will provide experimental evidence regarding the potential role of CBD as a wake-inducing drug. PMID:24851090

  13. Potential Effects of Cannabidiol as a Wake-Promoting Agent

    PubMed Central

    Murillo-Rodríguez, Eric; Sarro-Ramírez, Andrea; Sánchez, Daniel; Mijangos-Moreno, Stephanie; Tejeda-Padrón, Alma; Poot-Aké, Alwin; Guzmán, Khalil; Pacheco-Pantoja, Elda; Arias-Carrión, Oscar

    2014-01-01

    Over the last decades, the scientific interest in chemistry and pharmacology of cannabinoids has increased. Most attention has focused on ∆9-tetrahydrocannabinol (∆9-THC) as it is the psychoactive constituent of Cannabis sativa (C. sativa). However, in previous years, the focus of interest in the second plant constituent with non-psychotropic properties, cannabidiol (CBD) has been enhanced. Recently, several groups have investigated the pharmacological properties of CBD with significant findings; furthermore, this compound has raised promising pharmacological properties as a wake-inducing drug. In the current review, we will provide experimental evidence regarding the potential role of CBD as a wake-inducing drug. PMID:24851090

  14. Annexin A5 multitasking: a potentially novel antiatherothrombotic agent?

    PubMed

    Cederholm, Anna; Frostegård, Johan

    2007-06-01

    Atherothrombosis, formed on an underlying atherosclerotic plaque, is the key pathogenic mechanism behind the majority of clinically evident cardiovascular ischemic diseases including acute coronary artery disease, cerebrovascular and peripheral arterial occlusion. Annexin A5 (ANXA5; previously annexin V), a member of the annexin superfamily, is a protein with potent and unique antithrombotic properties. The antithrombotic effect exerted by ANXA5 is thought to be mediated mainly by mechanical shielding of phospholipids, phosphatidylserine in particular, thereby reducing their availability for coagulation reactions. However, other intriguing properties of ANXA5 potentially contributing to its antithrombotic function, especially downregulation of surface expressed tissue factor, or interaction with additional ligands involved in hemostasis such as sulfatide and heparin, as well as upregulation of urokinase-type plasminogen activator were reported. The biological significance of ANXA5 as a member of endogenous antithrombotic system in vivo has been suggested recently for the large vasculature and for placental microcirculation. Antiatherothrombotic potential of ANXA5 deserves further attention and careful studies in order to determine its true physiological impact as well as its possible therapeutic applications.

  15. Selection and characterization of Argentine isolates of Trichoderma harzianum for effective biocontrol of Septoria leaf blotch of wheat.

    PubMed

    Stocco, Marina C; Mónaco, Cecilia I; Abramoff, Cecilia; Lampugnani, Gladys; Salerno, Graciela; Kripelz, Natalia; Cordo, Cristina A; Consolo, Verónica F

    2016-03-01

    Species of the genus Trichoderma are economically important as biocontrol agents, serving as a potential alternative to chemical control. The applicability of Trichoderma isolates to different ecozones will depend on the behavior of the strains selected from each zone. The present study was undertaken to isolate biocontrol populations of Trichoderma spp. from the Argentine wheat regions and to select and characterize the best strains of Trichoderma harzianum by means of molecular techniques. A total of 84 out of the 240 strains of Trichoderma were able to reduce the disease severity of the leaf blotch of wheat. Thirty-seven strains were selected for the reduction equal to or greater than 50% of the severity, compared with the control. The percentage values of reduction of the pycnidial coverage ranged between 45 and 80%. The same last strains were confirmed as T. harzianum by polymerase chain reaction amplification of internal transcribed spacers, followed by sequencing. Inter-simple sequence repeat was used to examine the genetic variability among isolates. This resulted in a total of 132 bands. Further numerical analysis revealed 19 haplotypes, grouped in three clusters (I, II, III). Shared strains, with different geographical origins and isolated in different years, were observed within each cluster. The origin of the isolates and the genetic group were partially related. All isolates from Paraná were in cluster I, all isolates from Lobería were in cluster II, and all isolates from Pergamino and Santa Fe were in cluster III. Our results suggest that the 37 native strains of T. harzianum are important in biocontrol programs and could be advantageous for the preparation of biopesticides adapted to the agroecological conditions of wheat culture. PMID:26873560

  16. Selection and characterization of Argentine isolates of Trichoderma harzianum for effective biocontrol of Septoria leaf blotch of wheat.

    PubMed

    Stocco, Marina C; Mónaco, Cecilia I; Abramoff, Cecilia; Lampugnani, Gladys; Salerno, Graciela; Kripelz, Natalia; Cordo, Cristina A; Consolo, Verónica F

    2016-03-01

    Species of the genus Trichoderma are economically important as biocontrol agents, serving as a potential alternative to chemical control. The applicability of Trichoderma isolates to different ecozones will depend on the behavior of the strains selected from each zone. The present study was undertaken to isolate biocontrol populations of Trichoderma spp. from the Argentine wheat regions and to select and characterize the best strains of Trichoderma harzianum by means of molecular techniques. A total of 84 out of the 240 strains of Trichoderma were able to reduce the disease severity of the leaf blotch of wheat. Thirty-seven strains were selected for the reduction equal to or greater than 50% of the severity, compared with the control. The percentage values of reduction of the pycnidial coverage ranged between 45 and 80%. The same last strains were confirmed as T. harzianum by polymerase chain reaction amplification of internal transcribed spacers, followed by sequencing. Inter-simple sequence repeat was used to examine the genetic variability among isolates. This resulted in a total of 132 bands. Further numerical analysis revealed 19 haplotypes, grouped in three clusters (I, II, III). Shared strains, with different geographical origins and isolated in different years, were observed within each cluster. The origin of the isolates and the genetic group were partially related. All isolates from Paraná were in cluster I, all isolates from Lobería were in cluster II, and all isolates from Pergamino and Santa Fe were in cluster III. Our results suggest that the 37 native strains of T. harzianum are important in biocontrol programs and could be advantageous for the preparation of biopesticides adapted to the agroecological conditions of wheat culture.

  17. Myco-Biocontrol of Insect Pests: Factors Involved, Mechanism, and Regulation

    PubMed Central

    Sandhu, Sardul Singh; Sharma, Anil K.; Beniwal, Vikas; Goel, Gunjan; Batra, Priya; Kumar, Anil; Jaglan, Sundeep; Sharma, A. K.; Malhotra, Sonal

    2012-01-01

    The growing demand for reducing chemical inputs in agriculture and increased resistance to insecticides have provided great impetus to the development of alternative forms of insect-pest control. Myco-biocontrol offers an attractive alternative to the use of chemical pesticides. Myco-biocontrol agents are naturally occurring organisms which are perceived as less damaging to the environment. Their mode of action appears little complex which makes it highly unlikely that resistance could be developed to a biopesticide. Past research has shown some promise of the use of fungi as a selective pesticide. The current paper updates us about the recent progress in the field of myco-biocontrol of insect pests and their possible mechanism of action to further enhance our understanding about the biological control of insect pests. PMID:22567344

  18. Regulation of morphogenesis and biocontrol properties in Trichoderma virens by a VELVET protein, Vel1.

    PubMed

    Mukherjee, Prasun K; Kenerley, Charles M

    2010-04-01

    Mycoparasitic strains of Trichoderma are applied as commercial biofungicides for control of soilborne plant pathogens. Although the majority of commercial biofungicides are Trichoderma based, chemical pesticides, which are ecological and environmental hazards, still dominate the market. This is because biofungicides are not as effective or consistent as chemical fungicides. Efforts to improve these products have been limited by a lack of understanding of the genetic regulation of biocontrol activities. In this study, using gene knockout and complementation, we identified the VELVET protein Vel1 as a key regulator of biocontrol, as well as morphogenetic traits, in Trichoderma virens, a commercial biocontrol agent. Mutants with mutations in vel1 were defective in secondary metabolism (antibiosis), mycoparasitism, and biocontrol efficacy. In nutrient-rich media they also lacked two types of spores important for survival and development of formulation products: conidia (on agar) and chlamydospores (in liquid shake cultures). These findings provide an opportunity for genetic enhancement of biocontrol and industrial strains of Trichoderma, since Vel1 is very highly conserved across three Trichoderma species.

  19. Nutraceuticals as potential therapeutic agents for colon cancer: a review

    PubMed Central

    Kuppusamy, Palaniselvam; Yusoff, Mashitah M.; Maniam, Gaanty Pragas; Ichwan, Solachuddin Jauhari Arief; Soundharrajan, Ilavenil; Govindan, Natanamurugaraj

    2014-01-01

    Colon cancer is a world-wide health problem and the second-most dangerous type of cancer, affecting both men and women. The modern diet and lifestyles, with high meat consumption and excessive alcohol use, along with limited physical activity has led to an increasing mortality rate for colon cancer worldwide. As a result, there is a need to develop novel and environmentally benign drug therapies for colon cancer. Currently, nutraceuticals play an increasingly important role in the treatment of various chronic diseases such as colon cancer, diabetes and Alzheimer׳s disease. Nutraceuticals are derived from various natural sources such as medicinal plants, marine organisms, vegetables and fruits. Nutraceuticals have shown the potential to reduce the risk of colon cancer and slow its progression. These dietary substances target different molecular aspects of colon cancer development. Accordingly, this review briefly discusses the medicinal importance of nutraceuticals and their ability to reduce the risk of colorectal carcinogenesis. PMID:26579381

  20. Potential of iron chelators as effective antiproliferative agents.

    PubMed

    Richardson, D R

    1997-01-01

    Initially the impetus to develop iron (Fe) chelators for clinical use was based upon the need for a drug to treat Fe-overload diseases such as beta-thalassemia. However, it has become clear that Fe chelators may be useful for the treatment of a wide variety of disease states, including cancer, malaria, and free radical mediated injury. In particular, over the last 10 years a number of studies have shown that Fe chelators may be of use in the treatment of a number of aggressive human cancers, including neuroblastoma and leukemia, and several clinical trials have substantiated their potential. In the current review the role of Fe in cellular proliferation will be discussed, followed by the possible sites and mechanism of action of some of the most effective ligands. Attention will then be turned to examine the Fe chelators shown to possess antiproliferative activity and the clinical trials performed to assess their efficacy.

  1. Melatonin as a Potential Agent in the Treatment of Sarcopenia

    PubMed Central

    Coto-Montes, Ana; Boga, Jose A.; Tan, Dun X.; Reiter, Russel J.

    2016-01-01

    Considering the increased speed at which the world population is aging, sarcopenia could become an epidemic in this century. This condition currently has no means of prevention or treatment. Melatonin is a highly effective and ubiquitously acting antioxidant and free radical scavenger that is normally produced in all organisms. This molecule has been implicated in a huge number of biological processes, from anticonvulsant properties in children to protective effects on the lung in chronic obstructive pulmonary disease. In this review, we summarize the data which suggest that melatonin may be beneficial in attenuating, reducing or preventing each of the symptoms that characterize sarcopenia. The findings are not limited to sarcopenia, but also apply to osteoporosis-related sarcopenia and to age-related neuromuscular junction dysfunction. Since melatonin has a high safety profile and is drastically reduced in advanced age, its potential utility in the treatment of sarcopenic patients and related dysfunctions should be considered. PMID:27783055

  2. Potential Antiviral Agents from Marine Fungi: An Overview.

    PubMed

    Moghadamtousi, Soheil Zorofchian; Nikzad, Sonia; Kadir, Habsah Abdul; Abubakar, Sazaly; Zandi, Keivan

    2015-07-22

    Biodiversity of the marine world is only partially subjected to detailed scientific scrutiny in comparison to terrestrial life. Life in the marine world depends heavily on marine fungi scavenging the oceans of lifeless plants and animals and entering them into the nutrient cycle by. Approximately 150 to 200 new compounds, including alkaloids, sesquiterpenes, polyketides, and aromatic compounds, are identified from marine fungi annually. In recent years, numerous investigations demonstrated the tremendous potential of marine fungi as a promising source to develop new antivirals against different important viruses, including herpes simplex viruses, the human immunodeficiency virus, and the influenza virus. Various genera of marine fungi such as Aspergillus, Penicillium, Cladosporium, and Fusarium were subjected to compound isolation and antiviral studies, which led to an illustration of the strong antiviral activity of a variety of marine fungi-derived compounds. The present review strives to summarize all available knowledge on active compounds isolated from marine fungi with antiviral activity.

  3. Potential Antiviral Agents from Marine Fungi: An Overview

    PubMed Central

    Zorofchian Moghadamtousi, Soheil; Nikzad, Sonia; Abdul Kadir, Habsah; Abubakar, Sazaly; Zandi, Keivan

    2015-01-01

    Biodiversity of the marine world is only partially subjected to detailed scientific scrutiny in comparison to terrestrial life. Life in the marine world depends heavily on marine fungi scavenging the oceans of lifeless plants and animals and entering them into the nutrient cycle by. Approximately 150 to 200 new compounds, including alkaloids, sesquiterpenes, polyketides, and aromatic compounds, are identified from marine fungi annually. In recent years, numerous investigations demonstrated the tremendous potential of marine fungi as a promising source to develop new antivirals against different important viruses, including herpes simplex viruses, the human immunodeficiency virus, and the influenza virus. Various genera of marine fungi such as Aspergillus, Penicillium, Cladosporium, and Fusarium were subjected to compound isolation and antiviral studies, which led to an illustration of the strong antiviral activity of a variety of marine fungi-derived compounds. The present review strives to summarize all available knowledge on active compounds isolated from marine fungi with antiviral activity. PMID:26204947

  4. Potential Antiviral Agents from Marine Fungi: An Overview.

    PubMed

    Moghadamtousi, Soheil Zorofchian; Nikzad, Sonia; Kadir, Habsah Abdul; Abubakar, Sazaly; Zandi, Keivan

    2015-07-01

    Biodiversity of the marine world is only partially subjected to detailed scientific scrutiny in comparison to terrestrial life. Life in the marine world depends heavily on marine fungi scavenging the oceans of lifeless plants and animals and entering them into the nutrient cycle by. Approximately 150 to 200 new compounds, including alkaloids, sesquiterpenes, polyketides, and aromatic compounds, are identified from marine fungi annually. In recent years, numerous investigations demonstrated the tremendous potential of marine fungi as a promising source to develop new antivirals against different important viruses, including herpes simplex viruses, the human immunodeficiency virus, and the influenza virus. Various genera of marine fungi such as Aspergillus, Penicillium, Cladosporium, and Fusarium were subjected to compound isolation and antiviral studies, which led to an illustration of the strong antiviral activity of a variety of marine fungi-derived compounds. The present review strives to summarize all available knowledge on active compounds isolated from marine fungi with antiviral activity. PMID:26204947

  5. [Immunotropic activity of a potential antiparkinson agent himantane].

    PubMed

    Nezhinskaia, G I; Val'dman, E A; Nazarov, P G; Voronina, T A

    2001-01-01

    N-(Adamant-2-yl) hexamethyleneimine hydrochloride (A-7, himantane), a new potential antiparkinsonian drug belonging to the class of aminoadamantyl derivatives, exhibits pronounced immunomodulant activity in a therapeutic dose of 10 mg/kg. A single intraperitoneal injection of himantane stimulated a high B-lymphocyte activity in mice over a period of 21 days. The drug inhibited the reaction of delayed hypersensitivity with respect to the Freund adjuvant, while enhancing the immediate reaction with respect to horse serum in guinea pigs. Himantane increased the functional (absorption) activity of macrophages in the peritoneal exudate, while not affecting superoxide anion production by the macrophages. These results suggest that the immunomodulant activity of himantane may produce a positive neuroprotective and symptomatic effects in the course of parkinsonism. PMID:11548451

  6. Potential Antiosteoporotic Agents from Plants: A Comprehensive Review

    PubMed Central

    Jia, Min; Nie, Yan; Cao, Da-Peng; Xue, Yun-Yun; Wang, Jie-Si; Zhao, Lu; Rahman, Khalid; Zhang, Qiao-Yan; Qin, Lu-Ping

    2012-01-01

    Osteoporosis is a major health hazard and is a disease of old age; it is a silent epidemic affecting more than 200 million people worldwide in recent years. Based on a large number of chemical and pharmacological research many plants and their compounds have been shown to possess antiosteoporosis activity. This paper reviews the medicinal plants displaying antiosteoporosis properties including their origin, active constituents, and pharmacological data. The plants reported here are the ones which are commonly used in traditional medical systems and have demonstrated clinical effectiveness against osteoporosis. Although many plants have the potential to prevent and treat osteoporosis, so far, only a fraction of these plants have been thoroughly investigated for their physiological and pharmacological properties including their mechanism of action. An attempt should be made to highlight plant species with possible antiosteoporosis properties and they should be investigated further to help with future drug development for treating this disease. PMID:23365596

  7. Production of microsclerotia of the fungal entomopathogen Metarhizium anisopliae and their potential for use as a biocontrol agent for soil-inhabiting insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microsclerotia (MS), overwintering structures produced by many plant pathogenic fungi, have not been described for Metarhizium anisopliae. Three strains of M. anisopliae – F52, TM109, and MA1200 – formed MS in shake flask cultures using media with varying carbon concentrations and carbon-to-nitroge...

  8. Field host range of Apanteles opuntiarum (Hymenoptera: Braconidae) in Argentina, a potential biocontrol agent of Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cactoblastis cactorum (Berg) (Lepidoptera, Pyralidae) was successfully used for biological control of Opuntia spp. (Cactaceae) in Australia and South Africa, where no native cacti occur. Since 1989, this South American moth has been invading the southeastern United States, threatening the unique ca...

  9. Entomopathogenic fungi as potential biocontrol agents of the ecto-parasitic mite, Varroa destructor, and their effect on the immune response of honey bees (Apis mellifera L.).

    PubMed

    Hamiduzzaman, Mollah Md; Sinia, Alice; Guzman-Novoa, Ernesto; Goodwin, Paul H

    2012-11-01

    Three isolates of each of the entomopathogenic fungi, Metarhizium anisopliae, Beauveria bassiana and Clonostachys rosea, were assessed for their pathogenicity to the honey bee parasitic mite, Varroa destructor. The fungi were applied to varroa mites by immersing them in a spore solution, and then the inoculated mites were placed on honey bee brood inside capped cells. At 7 days post inoculation (dpi), the three fungi caused significant varroa mortality compared to non-inoculated mites. In brood treated only with varroa mites, expression of the honey bee genes, hymenoptaecin and poly U binding factor 68 Kd (pUf68), decreased over time, while expression of blue cheese (BlCh) and single minded (SiMd) was not affected. In brood inoculated directly only with M. anisopliae or B. bassiana, the emerged adults showed reduced weight indicating infection by the fungi, which was confirmed by observation of hyphae in the brood. Fungal infection of the brood resulted in increased expression of hymenoptaecin, pUf68 and BlCh, but not SiMd. In brood treated with varroa mites that had been inoculated with the fungi, expression of hymenoptaecin, pUf68 and BlCh, but not SiMd, was even more up-regulated. While varroa mites can suppress gene expression in honey bee brood, varroa mites infected with entomopathogenic fungi induced their expression. This may be due to a low level of fungal infection of the bee, which negated the immunosuppression by the mites. Therefore, entomopathogenic fungi could reduce varroa mite damage to honey bee brood by both infecting the parasite and preventing varroa-associated suppression of honey bee immunity.

  10. Potential of bacteriophage ΦAB2 as an environmental biocontrol agent for the control of multidrug-resistant Acinetobacter baumannii

    PubMed Central

    2013-01-01

    Background Multidrug-resistant Acinetobacter baumannii (MDRAB) is associated with nosocomial infections worldwide. To date, the use of a phage to prevent infections caused by MDRAB has not been demonstrated. Results The MDRAB-specific phage ϕAB2 was stable at 4°C and pH 7 in 0.5% chloroform solution, and showed a slight decrease in plaque-forming units (PFU)/ml of 0.3–0.9 log after 330 days of storage. The addition of ϕAB2 at a concentration of at least 105 PFU/ml to an A. baumannii M3237 suspension killed >99.9% of A. baumannii M3237 after 5 min, regardless of A. baumannii M3237 concentration (104, 105, or 106 colony-forming units (CFU)/ml). The addition of ϕAB2 at a concentration of 108 PFU/slide (>107 PFU/cm2) to glass slides containing A. baumannii M3237 at 104, 105, or 106 CFU/slide, significantly reduced bacterial numbers by 93%, 97%, and 99%, respectively. Thus, this concentration is recommended for decontamination of glass surfaces. Moreover, infusion of ϕAB2 into 10% glycerol exhibited strong anti-MDRAB activity (99.9% reduction), even after 90 days of storage. Treatment of a 10% paraffin oil-based lotion with ϕAB2 significantly reduced (99%) A. baumannii M3237 after 1 day of storage. However, ϕAB2 had no activity in the lotion after 1 month of storage. Conclusions Phages may be useful for reducing MDRAB contamination in liquid suspensions or on hard surfaces. Phages may also be inoculated into a solution to produce an antiseptic hand wash. However, the phage concentration and incubation time (the duration of phage contact with bacteria) should be carefully considered to reduce the risk of MDRAB contamination. PMID:23834712

  11. Toxicity of pirimiphos methyl (Actellic 25EC) on Anopheles gambiae s.s., Culex quinquefasciatus (Diptera: Culicidae), and potential biocontrol agent, Poecilia reticulata (Pisces: Poeciliidae).

    PubMed

    Anogwih, Joy A

    2014-08-01

    The toxicity of an emulsifiable formulation of pirimiphos methyl (Actellic 25EC) on Anopheles gambiae s.s. Giles, Culex quinquefasciatus Say (Diptera: Culicidae), and predator fish Poecilia reticulata Peters (Pisces: Poeciliidae) was investigated. Acute toxicity tests were carried out to determine the effect of the larvicide on mosquito larvae and fish species. To investigate the nontarget effects on P. reticulata, fish of similar size (3.5 +/- 0.2 cm) were randomly selected and exposed for 28 d, under static renewal bioassay, to sublethal concentrations of the larvicide capable of killing 30 and 70% of Cx. quinquefasciatus. The 24 h LC50 value of pirimiphos methyl on the test organisms ranged between 20.44 and 697.30 microg liter(-1). The ultrastructural changes observed in the intestinal cells of P. reticulata were characterized by degenerating cell membranes with gradual loss of gray area in pycnotic nucleus at lower concentration. Marked damage was found at higher concentration including distinct loss of gray areas in cytosol, absence of cristae, numerous ruptures, and several dead cells. Pirimiphos methyl was toxic to a predatory fish species, and for its relevance in vector control and crop protection, warrants cumulative assessment to establish its comprehensive ecological risk, and the dosage required for field larviciding.

  12. Characterization of a novel plant growth-promoting bacteria strain Delftia tsuruhatensis HR4 both as a diazotroph and a potential biocontrol agent against various plant pathogens.

    PubMed

    Han, Jigang; Sun, Lei; Dong, Xiuzhu; Cai, Zhengqiu; Sun, Xiaolu; Yang, Hailian; Wang, Yunshan; Song, Wei

    2005-01-01

    A novel, plant growth-promoting bacterium Delftia tsuruhatensis, strain HR4, was isolated from the rhizoplane of rice (Oryza sativa L., cv. Yueguang) in North China. In vitro antagonistic assay showed this strain could suppress the growth of various plant pathogens effectively, especially the three main rice pathogens (Xanthomonas oryzae pv. oryzae, Rhizoctonia solani and Pyricularia oryzae Cavara). Treated with strain HR4 culture, rice blast, rice bacterial blight and rice sheath blight for cv. Yuefu and cv. Nonghu 6 were evidently controlled in the greenhouse. Strain HR4 also showed a high nitrogen-fixing activity in N-free Döbereiner culture medium. The acetylene reduction activity and 15N2-fixing activity (N2FA) were 13.06 C2H4 nmolml(-1) h(-1) and 2.052 15Na.e.%, respectively. The nif gene was located in the chromosome of this strain. Based on phenotypic, physiological, biochemical and phylogenetic studies, strain HR4 could be classified as a member of D. tsuruhatensis. However, comparisons of characteristics with other known species of the genus Delftia suggested that strain HR4 was a novel dizotrophic PGPB strain. PMID:15709367

  13. Remineralizing potential of various agents on dental erosion

    PubMed Central

    Somani, Rani; Jaidka, Shipra; Singh, Deepti Jawa; Arora, Vanika

    2014-01-01

    Aim The purpose of this study is to compare the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP, Tooth Mousse) containing and casein phosphopeptide-amorphous calcium phosphate with fluoride (CPP-ACPF, Tooth Mousse Plus) containing pastes on dental erosion. Materials and methods Thirty permanent non-carious premolars indicated for orthodontic extraction were included in this study and were sectioned in mesiodistal direction vertically. After immersion in the carbonated drink for 14 min, samples were treated with various remineralizing pastes which were CPP-ACP containing paste (Tooth Mousse) and CPP-ACPF containing paste (Tooth Mousse Plus) according to the manufacturer's instructions. Vickers Microhardness was recorded at baseline, after exposure to erosive drink and after treatment with remineralizing pastes. Data obtained was statistically analysed using Student t-test with a level of significance set at p < 0.05. Results CPP-ACP (Tooth Mousse) and CPP-ACP with fluoride (Tooth Mousse Plus) resulted in 30.52% and 38.98% increase in post-erosion microhardness values respectively. The remineralizing potential of CPP-ACP with fluoride containing paste (Tooth Mousse Plus) was significantly better than that of CPP-ACP containing paste (Tooth Mousse) (p < 0.05). Conclusion Casein phosphopeptide-amorphous calcium phosphate with fluoride (CPP-ACPF, Tooth Mousse Plus) can be recommended to be used in preventing erosive tooth wear from acidic beverages. PMID:25737926

  14. Potential New Agents for the Management of Hyperkalemia.

    PubMed

    Packham, David K; Kosiborod, Mikhail

    2016-02-01

    Hyperkalemia is a common electrolyte disturbance with multiple potential etiologies. It is usually observed in the setting of reduced renal function. Mild to moderate hyperkalemia is usually asymptomatic, but is associated with poor prognosis. When severe, hyperkalemia may cause serious acute cardiac arrhythmias and conduction abnormalities, and may result in sudden death. The rising prevalence of conditions associated with hyperkalemia (heart failure, chronic kidney disease, and diabetes) and broad use of renin-angiotensin-aldosterone system (RAAS) inhibitors and mineralocorticoid receptor antagonists (MRAs), which improve patient outcomes but increase the risk of hyperkalemia, have led to a significant rise in hyperkalemia-related hospitalizations and deaths. Current non-invasive therapies for hyperkalemia either do not remove excess potassium or have poor efficacy and tolerability. There is a clear need for safer, more effective potassium-lowering therapies suitable for both acute and chronic settings. Patiromer sorbitex calcium and sodium zirconium cyclosilicate (ZS-9) are two new potassium-lowering compounds currently in development. Although they have not yet been approved by the US FDA, both have demonstrated efficacy and safety in recent trials. Patiromer sorbitex calcium is a polymer resin and sorbitol complex that binds potassium in exchange for calcium; ZS-9, a non-absorbed, highly selective inorganic cation exchanger, traps potassium in exchange for sodium and hydrogen. This review discusses the merits of both novel drugs and how they may help optimize the future management of patients with hyperkalemia.

  15. Morphine as a Potential Oxidative Stress-Causing Agent

    PubMed Central

    Skrabalova, Jitka; Drastichova, Zdenka; Novotny, Jiri

    2013-01-01

    Morphine exhibits important pharmacological effects for which it has been used in medical practice for quite a long time. However, it has a high addictive potential and can be abused. Long-term use of this drug can be connected with some pathological consequences including neurotoxicity and neuronal dysfunction, hepatotoxicity, kidney dysfunction, oxidative stress and apoptosis. Therefore, most studies examining the impact of morphine have been aimed at determining the effects induced by chronic morphine exposure in the brain, liver, cardiovascular system and macrophages. It appears that different tissues may respond to morphine diversely and are distinctly susceptible to oxidative stress and subsequent oxidative damage of biomolecules. Importantly, production of reactive oxygen/nitrogen species induced by morphine, which have been observed under different experimental conditions, can contribute to some pathological processes, degenerative diseases and organ dysfunctions occurring in morphine abusers or morphine-treated patients. This review attempts to provide insights into the possible relationship between morphine actions and oxidative stress. PMID:24376392

  16. Investigation of Stilbenoids as Potential Therapeutic Agents for Rotavirus Gastroenteritis.

    PubMed

    Ball, Judith M; Medina-Bolivar, Fabricio; Defrates, Katelyn; Hambleton, Emily; Hurlburt, Megan E; Fang, Lingling; Yang, Tianhong; Nopo-Olazabal, Luis; Atwill, Richard L; Ghai, Pooja; Parr, Rebecca D

    2015-01-01

    Rotavirus (RV) infections cause severe diarrhea in infants and young children worldwide. Vaccines are available but cost prohibitive for many countries and only reduce severe symptoms. Vaccinated infants continue to shed infectious particles, and studies show decreased efficacy of the RV vaccines in tropical and subtropical countries where they are needed most. Continuing surveillance for new RV strains, assessment of vaccine efficacy, and development of cost effective antiviral drugs remain an important aspect of RV studies. This study was to determine the efficacy of antioxidant and anti-inflammatory stilbenoids to inhibit RV replication. Peanut (A. hypogaea) hairy root cultures were induced to produce stilbenoids, which were purified by high performance countercurrent chromatography (HPCCC) and analyzed by HPLC. HT29.f8 cells were infected with RV in the presence stilbenoids. Cell viability counts showed no cytotoxic effects on HT29.f8 cells. Viral infectivity titers were calculated and comparatively assessed to determine the effects of stilbenoid treatments. Two stilbenoids, trans-arachidin-1 and trans-arachidin-3, show a significant decrease in RV infectivity titers. Western blot analyses performed on the infected cell lysates complemented the infectivity titrations and indicated a significant decrease in viral replication. These studies show the therapeutic potential of the stilbenoids against RV replication.

  17. Curcumin: a potential neuroprotective agent in Parkinson's disease.

    PubMed

    Mythri, R B; Bharath, M M Srinivas

    2012-01-01

    Parkinson's disease (PD) is an age-associated neurodegenerative disease clinically characterized as a movement disorder. The motor symptoms in PD arise due to selective degeneration of dopaminergic neurons in the substantia nigra of the ventral midbrain thereby depleting the dopamine levels in the striatum. Most of the current pharmacotherapeutic approaches in PD are aimed at replenishing the striatal dopamine. Although these drugs provide symptomatic relief during early PD, many patients develop motor complications with long-term treatment. Further, PD medications do not effectively tackle tremor, postural instability and cognitive deficits. Most importantly, most of these drugs do not exhibit neuroprotective effects in patients. Consequently, novel therapies involving natural antioxidants and plant products/molecules with neuroprotective properties are being exploited for adjunctive therapy. Curcumin is a polyphenol and an active component of turmeric (Curcuma longa), a dietary spice used in Indian cuisine and medicine. Curcumin exhibits antioxidant, anti-inflammatory and anti-cancer properties, crosses the blood-brain barrier and is neuroprotective in neurological disorders. Several studies in different experimental models of PD strongly support the clinical application of curcumin in PD. The current review explores the therapeutic potential of curcumin in PD. PMID:22211691

  18. β-Nitrostyrenes as Potential Anti-leishmanial Agents.

    PubMed

    Shafi, Syed; Afrin, Farhat; Islamuddin, Mohammad; Chouhan, Garima; Ali, Intzar; Naaz, Faatima; Sharma, Kalicharan; Zaman, Mohammad S

    2016-01-01

    Development of new therapeutic approach to treat leishmaniasis has become a priority. In the present study, the antileishmanial effect of β-nitrostyrenes was investigated against in vitro promastigotes and amastigotes. A series of β-nitrostyrenes have been synthesized by using Henry reaction and were evaluated for their antimicrobial activities by broth microdilution assay and in vitro antileishmanial activities against Leishmania donovani promastigotes by following standard guidelines. The most active compounds were futher evaluated for their in vitro antileishmanial activities against intracellular amastigotes. Among the tested β-nitrostyrenes, compounds 7, 8, 9, 12, and 17 exhibited potential activities (MICs range, 0.25-8 μg/mL) against clinically significant human pathogenic fungi. However, the microbactericidal concentrations (MBCs) and the microfungicidal concentrations (MFCs) were found to be either similar or only two-fold greater than the MICs. Anti-leishmanial results demonstrated that compounds 9, 12, 14, and 18 were found to be most active among the tested samples and exhibited 50% inhibitory concentration (IC50) by 23.40 ± 0.71, 37.83 ± 3.74, 40.50 ± 1.47, 55.66 ± 2.84 nM against L. donovani promastigotes and 30.5 ± 3.42, 21.46 ± 0.96, 26.43 ± 2.71, and 61.63 ± 8.02 nM respectively against intracellular L. donovani promastigotes amastigotes respectively which are comparable with standard AmB (19.60 ± 1.71 nM against promastigotes and 27.83 ± 3.26 nM against amastigotes). Compounds 9, 12, 14, and 18 were found to have potent in vitro leishmanicidal activity against L. donovani and found to be non-toxic against mammalian macrophages even at a concentration of 25 μM. Nitric oxide (NO) estimation studies reveals that these compounds are moderately inducing NO levels. PMID:27635124

  19. β-Nitrostyrenes as Potential Anti-leishmanial Agents

    PubMed Central

    Shafi, Syed; Afrin, Farhat; Islamuddin, Mohammad; Chouhan, Garima; Ali, Intzar; Naaz, Faatima; Sharma, Kalicharan; Zaman, Mohammad S.

    2016-01-01

    Development of new therapeutic approach to treat leishmaniasis has become a priority. In the present study, the antileishmanial effect of β-nitrostyrenes was investigated against in vitro promastigotes and amastigotes. A series of β-nitrostyrenes have been synthesized by using Henry reaction and were evaluated for their antimicrobial activities by broth microdilution assay and in vitro antileishmanial activities against Leishmania donovani promastigotes by following standard guidelines. The most active compounds were futher evaluated for their in vitro antileishmanial activities against intracellular amastigotes. Among the tested β-nitrostyrenes, compounds 7, 8, 9, 12, and 17 exhibited potential activities (MICs range, 0.25–8 μg/mL) against clinically significant human pathogenic fungi. However, the microbactericidal concentrations (MBCs) and the microfungicidal concentrations (MFCs) were found to be either similar or only two-fold greater than the MICs. Anti-leishmanial results demonstrated that compounds 9, 12, 14, and 18 were found to be most active among the tested samples and exhibited 50% inhibitory concentration (IC50) by 23.40 ± 0.71, 37.83 ± 3.74, 40.50 ± 1.47, 55.66 ± 2.84 nM against L. donovani promastigotes and 30.5 ± 3.42, 21.46 ± 0.96, 26.43 ± 2.71, and 61.63 ± 8.02 nM respectively against intracellular L. donovani promastigotes amastigotes respectively which are comparable with standard AmB (19.60 ± 1.71 nM against promastigotes and 27.83 ± 3.26 nM against amastigotes). Compounds 9, 12, 14, and 18 were found to have potent in vitro leishmanicidal activity against L. donovani and found to be non-toxic against mammalian macrophages even at a concentration of 25 μM. Nitric oxide (NO) estimation studies reveals that these compounds are moderately inducing NO levels.

  20. Hypochlorous Acid as a Potential Wound Care Agent

    PubMed Central

    Wang, L; Bassiri, M; Najafi, R; Najafi, K; Yang, J; Khosrovi, B; Hwong, W; Barati, E; Belisle, B; Celeri, C; Robson, MC

    2007-01-01

    Objective: Hypochlorous acid (HOCl), a major inorganic bactericidal compound of innate immunity, is effective against a broad range of microorganisms. Owing to its chemical nature, HOCl has never been used as a pharmaceutical drug for treating infection. In this article, we describe the chemical production, stabilization, and biological activity of a pharmaceutically useful formulation of HOCl. Methods: Stabilized HOCl is in the form of a physiologically balanced solution in 0.9% saline at a pH range of 3.5 to 4.0. Chlorine species distribution in solution is a function of pH. In aqueous solution, HOCl is the predominant species at the pH range of 3 to 6. At pH values less than 3.5, the solution exists as a mixture of chlorine in aqueous phase, chlorine gas, trichloride (Cl3−), and HOCl. At pH greater than 5.5, sodium hypochlorite (NaOCl) starts to form and becomes the predominant species in the alkaline pH. To maintain HOCl solution in a stable form, maximize its antimicrobial activities, and minimize undesirable side products, the pH must be maintained at 3.5 to 5. Results: Using this stabilized form of HOCl, the potent antimicrobial activities of HOCl are demonstrated against a wide range of microorganisms. The in vitro cytotoxicity profile in L929 cells and the in vivo safety profile of HOCl in various animal models are described. Conclusion: On the basis of the antimicrobial activity and the lack of animal toxicity, it is predicted that stabilized HOCl has potential pharmaceutical applications in the control of soft tissue infection. PMID:17492050

  1. Bio-Control of Salmonella Enteritidis in Foods Using Bacteriophages

    PubMed Central

    Bao, Hongduo; Zhang, Pengyu; Zhang, Hui; Zhou, Yan; Zhang, Lili; Wang, Ran

    2015-01-01

    Two lytic phages, vB_SenM-PA13076 (PA13076) and vB_SenM-PC2184 (PC2184), were isolated from chicken sewage and characterized with host strains Salmonella Enteritidis (SE) ATCC13076 and CVCC2184, respectively. Transmission electron microscopy revealed that they belonged to the family Myoviridae. The lytic abilities of these two phages in liquid culture showed 104 multiplicity of infection (MOI) was the best in inhibiting bacteria, with PC2184 exhibiting more activity than PA13076. The two phages exhibited broad host range within the genus Salmonella. Phage PA13076 and PC2184 had a lytic effect on 222 (71.4%) and 298 (95.8%) of the 311 epidemic Salmonella isolates, respectively. We tested the effectiveness of phage PA13076 and PC2184 as well as a cocktail combination of both in three different foods (chicken breast, pasteurized whole milk and Chinese cabbage) contaminated with SE. Samples were spiked with 1 × 104 CFU individual SE or a mixture of strains (ATCC13076 and CVCC2184), then treated with 1 × 108 PFU individual phage or a two phage cocktail, and incubated at 4 °C or 25 °C for 5 h. In general, the inhibitory effect of phage and phage cocktail was better at 4 °C than that at 25 °C, whereas the opposite result was observed in Chinese cabbage, and phage cocktail was better than either single phage. A significant reduction in bacterial numbers (1.5–4 log CFU/sample, p < 0.05) was observed in all tested foods. The two phages on the three food samples were relatively stable, especially at 4 °C, with the phages exhibiting the greatest stability in milk. Our research shows that our phages have potential effectiveness as a bio-control agent of Salmonella in foods. PMID:26305252

  2. Bio-Control of Salmonella Enteritidis in Foods Using Bacteriophages.

    PubMed

    Bao, Hongduo; Zhang, Pengyu; Zhang, Hui; Zhou, Yan; Zhang, Lili; Wang, Ran

    2015-08-24

    Two lytic phages, vB_SenM-PA13076 (PA13076) and vB_SenM-PC2184 (PC2184), were isolated from chicken sewage and characterized with host strains Salmonella Enteritidis (SE) ATCC13076 and CVCC2184, respectively. Transmission electron microscopy revealed that they belonged to the family Myoviridae. The lytic abilities of these two phages in liquid culture showed 104 multiplicity of infection (MOI) was the best in inhibiting bacteria, with PC2184 exhibiting more activity than PA13076. The two phages exhibited broad host range within the genus Salmonella. Phage PA13076 and PC2184 had a lytic effect on 222 (71.4%) and 298 (95.8%) of the 311 epidemic Salmonella isolates, respectively. We tested the effectiveness of phage PA13076 and PC2184 as well as a cocktail combination of both in three different foods (chicken breast, pasteurized whole milk and Chinese cabbage) contaminated with SE. Samples were spiked with 1 × 10(4) CFU individual SE or a mixture of strains (ATCC13076 and CVCC2184), then treated with 1 × 10(8) PFU individual phage or a two phage cocktail, and incubated at 4 °C or 25 °C for 5 h. In general, the inhibitory effect of phage and phage cocktail was better at 4 °C than that at 25 °C, whereas the opposite result was observed in Chinese cabbage, and phage cocktail was better than either single phage. A significant reduction in bacterial numbers (1.5-4 log CFU/sample, p < 0.05) was observed in all tested foods. The two phages on the three food samples were relatively stable, especially at 4 ºC, with the phages exhibiting the greatest stability in milk. Our research shows that our phages have potential effectiveness as a bio-control agent of Salmonella in foods.

  3. Bio-Control of Salmonella Enteritidis in Foods Using Bacteriophages.

    PubMed

    Bao, Hongduo; Zhang, Pengyu; Zhang, Hui; Zhou, Yan; Zhang, Lili; Wang, Ran

    2015-08-01

    Two lytic phages, vB_SenM-PA13076 (PA13076) and vB_SenM-PC2184 (PC2184), were isolated from chicken sewage and characterized with host strains Salmonella Enteritidis (SE) ATCC13076 and CVCC2184, respectively. Transmission electron microscopy revealed that they belonged to the family Myoviridae. The lytic abilities of these two phages in liquid culture showed 104 multiplicity of infection (MOI) was the best in inhibiting bacteria, with PC2184 exhibiting more activity than PA13076. The two phages exhibited broad host range within the genus Salmonella. Phage PA13076 and PC2184 had a lytic effect on 222 (71.4%) and 298 (95.8%) of the 311 epidemic Salmonella isolates, respectively. We tested the effectiveness of phage PA13076 and PC2184 as well as a cocktail combination of both in three different foods (chicken breast, pasteurized whole milk and Chinese cabbage) contaminated with SE. Samples were spiked with 1 × 10(4) CFU individual SE or a mixture of strains (ATCC13076 and CVCC2184), then treated with 1 × 10(8) PFU individual phage or a two phage cocktail, and incubated at 4 °C or 25 °C for 5 h. In general, the inhibitory effect of phage and phage cocktail was better at 4 °C than that at 25 °C, whereas the opposite result was observed in Chinese cabbage, and phage cocktail was better than either single phage. A significant reduction in bacterial numbers (1.5-4 log CFU/sample, p < 0.05) was observed in all tested foods. The two phages on the three food samples were relatively stable, especially at 4 ºC, with the phages exhibiting the greatest stability in milk. Our research shows that our phages have potential effectiveness as a bio-control agent of Salmonella in foods. PMID:26305252

  4. β-Nitrostyrenes as Potential Anti-leishmanial Agents

    PubMed Central

    Shafi, Syed; Afrin, Farhat; Islamuddin, Mohammad; Chouhan, Garima; Ali, Intzar; Naaz, Faatima; Sharma, Kalicharan; Zaman, Mohammad S.

    2016-01-01

    Development of new therapeutic approach to treat leishmaniasis has become a priority. In the present study, the antileishmanial effect of β-nitrostyrenes was investigated against in vitro promastigotes and amastigotes. A series of β-nitrostyrenes have been synthesized by using Henry reaction and were evaluated for their antimicrobial activities by broth microdilution assay and in vitro antileishmanial activities against Leishmania donovani promastigotes by following standard guidelines. The most active compounds were futher evaluated for their in vitro antileishmanial activities against intracellular amastigotes. Among the tested β-nitrostyrenes, compounds 7, 8, 9, 12, and 17 exhibited potential activities (MICs range, 0.25–8 μg/mL) against clinically significant human pathogenic fungi. However, the microbactericidal concentrations (MBCs) and the microfungicidal concentrations (MFCs) were found to be either similar or only two-fold greater than the MICs. Anti-leishmanial results demonstrated that compounds 9, 12, 14, and 18 were found to be most active among the tested samples and exhibited 50% inhibitory concentration (IC50) by 23.40 ± 0.71, 37.83 ± 3.74, 40.50 ± 1.47, 55.66 ± 2.84 nM against L. donovani promastigotes and 30.5 ± 3.42, 21.46 ± 0.96, 26.43 ± 2.71, and 61.63 ± 8.02 nM respectively against intracellular L. donovani promastigotes amastigotes respectively which are comparable with standard AmB (19.60 ± 1.71 nM against promastigotes and 27.83 ± 3.26 nM against amastigotes). Compounds 9, 12, 14, and 18 were found to have potent in vitro leishmanicidal activity against L. donovani and found to be non-toxic against mammalian macrophages even at a concentration of 25 μM. Nitric oxide (NO) estimation studies reveals that these compounds are moderately inducing NO levels. PMID:27635124

  5. Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis

    PubMed Central

    Großkinsky, Dominik K.; Tafner, Richard; Moreno, María V.; Stenglein, Sebastian A.; García de Salamone, Inés E.; Nelson, Louise M.; Novák, Ondřej; Strnad, Miroslav; van der Graaff, Eric; Roitsch, Thomas

    2016-01-01

    Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience. PMID:26984671

  6. Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis.

    PubMed

    Großkinsky, Dominik K; Tafner, Richard; Moreno, María V; Stenglein, Sebastian A; García de Salamone, Inés E; Nelson, Louise M; Novák, Ondřej; Strnad, Miroslav; van der Graaff, Eric; Roitsch, Thomas

    2016-01-01

    Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience. PMID:26984671

  7. Synthetic Ni3S2/Ni hybrid architectures as potential contrast agents in MRI

    NASA Astrophysics Data System (ADS)

    Ma, J.; Chen, K.

    2016-04-01

    Traditional magnetic resonance imaging (MRI) contrast agents mainly include superparamagnetic (SPM) iron oxide nanoparticle as T 2 contrast agent for liver and paramagnetic Gd (III)-chelate as T 1 contrast agent for all organs. In this work, weak ferromagnetic kale-like and SPM cabbage-like Ni3S2@Ni hybrid architectures were synthesized and evaluated as potential T 1 MRI contrast agents. Their relatively small r 2/r 1 ratios of 2.59 and 2.38, and high r 1 values of 11.27 and 4.89 mmol-1 L s-1 (for the kale-like and cabbage-like Ni3S2@Ni, respectively) will shed some light on the development of new-type MRI contrast agents.

  8. Synthetic Ni3S2/Ni hybrid architectures as potential contrast agents in MRI

    NASA Astrophysics Data System (ADS)

    Ma, J.; Chen, K.

    2016-04-01

    Traditional magnetic resonance imaging (MRI) contrast agents mainly include superparamagnetic (SPM) iron oxide nanoparticle as T 2 contrast agent for liver and paramagnetic Gd (III)-chelate as T 1 contrast agent for all organs. In this work, weak ferromagnetic kale-like and SPM cabbage-like Ni3S2@Ni hybrid architectures were synthesized and evaluated as potential T 1 MRI contrast agents. Their relatively small r 2/r 1 ratios of 2.59 and 2.38, and high r 1 values of 11.27 and 4.89 mmol‑1 L s‑1 (for the kale-like and cabbage-like Ni3S2@Ni, respectively) will shed some light on the development of new-type MRI contrast agents.

  9. Indigenous bacteria may interfere with the biocontrol of plant diseases

    NASA Astrophysics Data System (ADS)

    Someya, Nobutaka; Akutsu, Katsumi

    2009-06-01

    Prodigiosin is a reddish antibiotic pigment that plays an important role in the biocontrol of plant diseases by the bacterium Serratia marcescens. However, its activity is unstable under agricultural conditions; further, it can be degraded by various environmental factors. To examine the effect of epiphytic microbes on the stability of prodigiosin used for biological control processes, we collected a total of 1,280 bacterial isolates from the phylloplane of cyclamen and tomato plants. Approximately 72% of the bacterial strains isolated from the cyclamen plants and 66% of those isolated from the tomato plants grew on minimal agar medium containing 100 μg ml-1 prodigiosin. Certain isolates obtained from both plant species exhibited prodigiosin-degrading activity. We compared the 16S rRNA gene sequences derived from the isolates with sequences in a database. The comparison revealed that the sequences determined for the prodigiosin-degrading isolates were homologous to those of the genera Pseudomonas, Caulobacter, Rhizobium, Sphingomonas, Janthinobacterium, Novosphingobium, and Rathayibacter. These results indicate that indigenous epiphytic microorganisms may interfere with the interaction between plant pathogens and biocontrol agents by degrading the antibiotics produced by the agents.

  10. Antifungal Activity of Isolated Bacillus amyloliquefaciens SYBC H47 for the Biocontrol of Peach Gummosis.

    PubMed

    Li, Xunhang; Zhang, Yanzhou; Wei, Zhiwen; Guan, Zhengbing; Cai, Yujie; Liao, Xiangru

    2016-01-01

    and the growth of mycelia from B. dothidea; therefore, this strain behaves as a potential biocontrol agent against the gummosis disease. PMID:27583463

  11. Antifungal Activity of Isolated Bacillus amyloliquefaciens SYBC H47 for the Biocontrol of Peach Gummosis

    PubMed Central

    Zhang, Yanzhou; Wei, Zhiwen; Guan, Zhengbing; Cai, Yujie; Liao, Xiangru

    2016-01-01

    and the growth of mycelia from B. dothidea; therefore, this strain behaves as a potential biocontrol agent against the gummosis disease. PMID:27583463

  12. The role of potential agents in making spatial perspective taking social

    PubMed Central

    Clements-Stephens, Amy M.; Vasiljevic, Katarina; Murray, Alexandra J.; Shelton, Amy L.

    2013-01-01

    A striking relationship between visual spatial perspective taking (VSPT) and social skills has been demonstrated for perspective-taking tasks in which the target of the imagined or inferred perspective is a potential agent, suggesting that the presence of a potential agent may create a social context for the seemingly spatial task of imagining a novel visual perspective. In a series of studies, we set out to investigate how and when a target might be viewed as sufficiently agent-like to incur a social influence on VSPT performance. By varying the perceptual and conceptual features that defined the targets as potential agents, we find that even something as simple as suggesting animacy for a simple wooden block may be sufficient. More critically, we found that experience with one potential agent influenced the performance with subsequent targets, either by inducing or eliminating the influence of social skills on VSPT performance. These carryover effects suggest that the relationship between social skills and VSPT performance is mediated by a complex relationship that includes the task, the target, and the context in which that target is perceived. These findings highlight potential problems that arise when identifying a task as belonging exclusively to a single cognitive domain and stress instead the highly interactive nature of cognitive domains and their susceptibility to cross-domain individual differences. PMID:24046735

  13. CHARACTERIZATION AND BIOCONTROL POTENT OF STREPTOMYCES SP. ISOLATED FROM THE RHIZOSPHERE OF ONONIS ANGUSTISSIMA LAM.

    PubMed

    Ghadbane, M; Belhadj, H; Medjekal, S; Harzallah, D

    2015-01-01

    A total of 40 actinomycetes isolated from rhizosphere soils of Ononis angustissima Lam. were in vitro tested for their antagonism against deferent pathogenic microorganisms by streak assay. Among the isolates, four (21, 2A26, 1B10 and 2C34) present a potent antagonism against both pathogenic bacteria and fungi, they were selected, identified by 16S rDNA sequence analysis and phenotypic properties, and tested for their antimicrobial activity as well as their biocontrol potential against Chickpea (Cicer arietinum L.) pathogenic fungus (Fusarium oxysporum). Cultural characteristic studies strongly suggested that these strains belong to the genus Streptomyces. The four Streptomyces sp., solubilize phosphate and produce extracellular fungal cell-wall degrading enzymes chitinase and protease, as well as a marked production of acid-β-indole acetic (AIA). The nucleotide sequence of the 16S rRNA gene of Streptomyces sp. strains 21, 2A26, 1B10 and 2C34 exhibited close similarity (62-75%) with Streptomyces parvulus MARS 16S rRNA genes. The inhibition was higher against fungi and Gram+ bacteria, while Gram- bacteria were less inhibited. The growth of the plant pathogenic fungus Fusarium oxysporum was considerably inhibited in the presence of the strains 21, 2A26, 1B10 and 2C34 culture supernatant. These studies revealed that the presence of the Streptomyces strains in the soil significantly promoted the growth of the Chickpea plants. These results indicate that the Streptomyces strains isolated for rhizosphere from Ononis angustissima Lam. growing in arid conditions in southern Algeria (Sahara) could be an interesting source for antimicrobial bioactive substances and as biocontrol agents.

  14. CHARACTERIZATION AND BIOCONTROL POTENT OF STREPTOMYCES SP. ISOLATED FROM THE RHIZOSPHERE OF ONONIS ANGUSTISSIMA LAM.

    PubMed

    Ghadbane, M; Belhadj, H; Medjekal, S; Harzallah, D

    2015-01-01

    A total of 40 actinomycetes isolated from rhizosphere soils of Ononis angustissima Lam. were in vitro tested for their antagonism against deferent pathogenic microorganisms by streak assay. Among the isolates, four (21, 2A26, 1B10 and 2C34) present a potent antagonism against both pathogenic bacteria and fungi, they were selected, identified by 16S rDNA sequence analysis and phenotypic properties, and tested for their antimicrobial activity as well as their biocontrol potential against Chickpea (Cicer arietinum L.) pathogenic fungus (Fusarium oxysporum). Cultural characteristic studies strongly suggested that these strains belong to the genus Streptomyces. The four Streptomyces sp., solubilize phosphate and produce extracellular fungal cell-wall degrading enzymes chitinase and protease, as well as a marked production of acid-β-indole acetic (AIA). The nucleotide sequence of the 16S rRNA gene of Streptomyces sp. strains 21, 2A26, 1B10 and 2C34 exhibited close similarity (62-75%) with Streptomyces parvulus MARS 16S rRNA genes. The inhibition was higher against fungi and Gram+ bacteria, while Gram- bacteria were less inhibited. The growth of the plant pathogenic fungus Fusarium oxysporum was considerably inhibited in the presence of the strains 21, 2A26, 1B10 and 2C34 culture supernatant. These studies revealed that the presence of the Streptomyces strains in the soil significantly promoted the growth of the Chickpea plants. These results indicate that the Streptomyces strains isolated for rhizosphere from Ononis angustissima Lam. growing in arid conditions in southern Algeria (Sahara) could be an interesting source for antimicrobial bioactive substances and as biocontrol agents. PMID:27141751

  15. Can efficacy of new agents be predicted before their release?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prediction of the efficacy of new biocontrol agents before their release, while desirable and of scientific interest, is not possible at this time. Several approaches that attempt to do so are discussed. Measurement of per capita impact is recommended by some weed biocontrol scientists but does not...

  16. Macromolecular Imaging Agents Containing Lanthanides: Can Conceptual Promise Lead to Clinical Potential?

    PubMed Central

    Bryson, Joshua; Reineke, Jeffrey W.; Reineke, Theresa M.

    2012-01-01

    Macromolecular magnetic resonance imaging (MRI) contrast agents are increasingly being used to improve the resolution of this noninvasive diagnostic technique. All clinically-approved T1 contrast agents are small molecule chelates of gadolinium [Gd(III)] that affect bound water proton relaxivity. Both the small size and monomeric nature of these agents ultimately limits the image resolution enhancement that can be achieved for both contrast enhancement and pharmacokinetic/biodistribution reasons. The multimeric nature of macromolecules, such as polymers, dendrimers, and noncovalent complexes of small molecule agents with proteins, have been shown to significantly increase the image contrast and resolution due to their large size and ability to incorporate multiple Gd(III) chlelation sites. Also, macromolecular agents are advantageous as they have the ability to be designed to be nontoxic, hydrophilic, easily purified, aggregation-resistant, and have controllable three-dimensional macromolecular structure housing the multiple lanthanide chelation sites. For these reasons, large molecule diagnostics have the ability to significantly increase the relaxivity of water protons within the targeted tissues and thus the image resolution for many diagnostic applications. The FDA approval of a contrast agent that consists of a reversible, non-covalent coupling of a small Gd(III) chelate with serum albumin for blood pool imaging (marketed under the trade names of Vasovist and Ablivar) proved to be one of the first diagnostic agent to capitalize on these benefits from macromolecular association in humans. However, much research and development is necessary to optimize the safety of these unique agents for in vivo use and potential clinical development. To this end, recent work in the field of polymer, dendrimer, and noncovalent complex-based imaging agents are reviewed herein and the future outlook of this field is discussed. PMID:23467737

  17. Biocontrol of Aspergillus species on peanut kernels by antifungal diketopiperazine producing Bacillus cereus associated with entomopathogenic nematode.

    PubMed

    Kumar, Sasidharan Nishanth; Sreekala, Sreerag Ravikumar; Chandrasekaran, Dileep; Nambisan, Bala; Anto, Ruby John

    2014-01-01

    The rhabditid entomopathogenic nematode associated Bacillus cereus and the antifungal compounds produced by this bacterium were evaluated for their activity in reducing postharvest decay of peanut kernels caused by Aspergillus species in in vitro and in vivo tests. The results showed that B. cereus had a significant effect on biocontrol effectiveness in in vitro and in vivo conditions. The antifungal compounds produced by the B. cereus were purified using silica gel column chromatography and their structure was elucidated using extensive spectral analyses. The compounds were identified as diketopiperazines (DKPs) [cyclo-(L-Pro-Gly), cyclo(L-Tyr-L-Tyr), cyclo-(L-Phe-Gly) and cyclo(4-hydroxy-L-Pro-L-Trp)]. The antifungal activities of diketopiperazines were studied against five Aspergillus species and best MIC of 2 µg/ml was recorded against A. flavus by cyclo(4-hydroxy-L-Pro-L-Trp). To investigate the potential application of cyclo(4-hydroxy-L-Pro-L-Trp) to eliminate fungal spoilage in food and feed, peanut kernels was used as a food model system. White mycelia and dark/pale green spores of Aspergillus species were observed in the control peanut kernels after 2 days incubation. However the fungal growth was not observed in peanut kernels treated with cyclo(4-hydroxy-L-Pro-L-Trp). The cyclo(4-hydroxy-L-Pro-L-Trp) was nontoxic to two normal cell lines [fore skin (FS) normal fibroblast and African green monkey kidney (VERO)] up to 200 µg/ml in MTT assay. Thus the cyclo(4-hydroxy-L-Pro-L-Trp) identified in this study may be a promising alternative to chemical preservatives as a potential biopreservative agent which prevent fungal growth in food and feed. To the best of our knowledge, this is the first report demonstrating that the entomopathogenic nematode associated B. cereus and cyclo(4-hydroxy-L-Pro-L-Trp) could be used as a biocontrol agents against postharvest fungal disease caused by Aspergillus species.

  18. Imaging of hemorrhagic fever with renal syndrome: a potential bioterrorism agent of military significance.

    PubMed

    Bui-Mansfield, Liem T; Cressler, Dana K

    2011-11-01

    Hemorrhagic fever with renal syndrome (HFRS) is a potentially fatal infectious disease with worldwide distribution. Its etiologic agents are viruses of the genus Hantavirus of the virus family Bunyaviridae. Hypothetical ease of production and distribution of these agents, with their propensity to incapacitate victims and overwhelm health care resources, lend themselves as significant potential biological agents of terrorism. HFRS has protean clinical manifestations, which may mimic upper respiratory tract infection, nephrolithiasis, and Hantavirus pulmonary syndrome and may delay proper treatment. Sequelae of HFRS, such as hemorrhage, acute renal failure, retroperitoneal edema, pancreatitis, pulmonary edema, and neurologic symptoms, can be detected by different imaging modalities. Medical providers caring for HFRS patients must be aware of its radiologic features, which may help to confirm its clinical diagnosis. In this article, the authors review the epidemiology, pathophysiology, clinical presentation, diagnosis, treatment, and complications of HFRS. PMID:22165665

  19. Progress in Nanotechnology Based Approaches to Enhance the Potential of Chemopreventive Agents

    PubMed Central

    Muqbil, Irfana; Masood, Ashiq; Sarkar, Fazlul H.; Mohammad, Ramzi M.; Azmi, Asfar S.

    2011-01-01

    Cancer chemoprevention is defined as the use of natural agents to suppress, reverse or prevent the carcinogenic process from turning into aggressive cancer. Over the last two decades, multiple natural dietary compounds with diverse chemical structures such flavonoids, tannins, curcumins and polyphenols have been proposed as chemopreventive agents. These agents have proven excellent anticancer potential in the laboratory setting, however, the observed effects in vitro do not translate in clinic where they fail to live up to their expectations. Among the various reasons for this discrepancy include inefficient systemic delivery and robust bioavailability. To overcome this barrier, researchers have focused towards coupling these agents with nano based encapsulation technology that in principle will enhance bioavailability and ultimately benefit clinical outcome. The last decade has witnessed rapid advancement in the development of nanochemopreventive technology with emergence of many nano encapsulated formulations of different dietary anticancer agents. This review summarizes the most up-to-date knowledge on the studies performed in nanochemoprevention, their proposed use in the clinic and future directions in which this field is heading. As the knowledge of the dynamics of nano encapsulation evolves, it is expected that researchers will bring forward newer and far more superior nanochemopreventive agents that may become standard drugs for different cancers. PMID:24212623

  20. Intelligent Agents and Their Potential for Future Design and Synthesis Environment

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K. (Compiler); Malone, John B. (Compiler)

    1999-01-01

    This document contains the proceedings of the Workshop on Intelligent Agents and Their Potential for Future Design and Synthesis Environment, held at NASA Langley Research Center, Hampton, VA, September 16-17, 1998. The workshop was jointly sponsored by the University of Virginia's Center for Advanced Computational Technology and NASA. Workshop attendees came from NASA, industry and universities. The objectives of the workshop were to assess the status of intelligent agents technology and to identify the potential of software agents for use in future design and synthesis environment. The presentations covered the current status of agent technology and several applications of intelligent software agents. Certain materials and products are identified in this publication in order to specify adequately the materials and products that were investigated in the research effort. In no case does such identification imply recommendation or endorsement of products by NASA, nor does it imply that the materials and products are the only ones or the best ones available for this purpose. In many cases equivalent materials and products are available and would probably produce equivalent results.

  1. Molecular effective coverage surface area of optical clearing agents for predicting optical clearing potential

    NASA Astrophysics Data System (ADS)

    Feng, Wei; Ma, Ning; Zhu, Dan

    2015-03-01

    The improvement of methods for optical clearing agent prediction exerts an important impact on tissue optical clearing technique. The molecular dynamic simulation is one of the most convincing and simplest approaches to predict the optical clearing potential of agents by analyzing the hydrogen bonds, hydrogen bridges and hydrogen bridges type forming between agents and collagen. However, the above analysis methods still suffer from some problem such as analysis of cyclic molecule by reason of molecular conformation. In this study, a molecular effective coverage surface area based on the molecular dynamic simulation was proposed to predict the potential of optical clearing agents. Several typical cyclic molecules, fructose, glucose and chain molecules, sorbitol, xylitol were analyzed by calculating their molecular effective coverage surface area, hydrogen bonds, hydrogen bridges and hydrogen bridges type, respectively. In order to verify this analysis methods, in vitro skin samples optical clearing efficacy were measured after 25 min immersing in the solutions, fructose, glucose, sorbitol and xylitol at concentration of 3.5 M using 1951 USAF resolution test target. The experimental results show accordance with prediction of molecular effective coverage surface area. Further to compare molecular effective coverage surface area with other parameters, it can show that molecular effective coverage surface area has a better performance in predicting OCP of agents.

  2. Rapid, cell-based toxicity screen of potentially therapeutic post-transcriptional gene silencing agents.

    PubMed

    Kolniak, Tiffany A; Sullivan, Jack M

    2011-05-01

    Post-transcriptional gene silencing (PTGS) agents such as antisense, ribozymes and RNA interference (RNAi) have great potential as therapeutics for a variety of eye diseases including retinal and macular degenerations, glaucoma, corneal degenerations, inflammatory and viral conditions. Despite their great potential and over thirty years of academic and corporate research only a single PTGS agent is currently approved for human therapy for a single disease. Substantial challenges exist to achieving both efficacious and safe PTGS agents. Efficacy, as measured in specific target mRNA and protein knockdown, depends upon a number of complex factors including the identification of rare regions of target mRNA accessibility, cellular co-localization of the PTGS agent in sufficient concentration with the target mRNA, and stability of the PTGS agent in the target cells in which it is delivered or expressed. Safety is commonly measured by lack of cytotoxicity or other deleterious cellular responses in cells in which the PTGS agent is delivered or expressed. To relieve major bottlenecks in RNA drug discovery novel, efficient, inexpensive, and rapid tools are needed to facilitate lead identification of the most efficacious PTGS agent, rational optimization of efficacy of the lead agent, and lead agent safety determinations. We have developed a technological platform using cell culture expression systems that permits lead identification and efficacy optimization of PTGS agents against arbitrary disease target mRNAs under relatively high throughput conditions. Here, we extend the technology platform to include PTGS safety determinations in cultured human cells that are expected to represent the common cellular housekeeping microenvironment. We developed a high throughput screening (HTS) cytotoxicity assay in 96-well plate format based around the SYTOX Green dye which is excluded from healthy viable cells and becomes substantially fluorescent only after entering cells and binding

  3. Rapid, cell-based toxicity screen of potentially therapeutic post-transcriptional gene silencing agents.

    PubMed

    Kolniak, Tiffany A; Sullivan, Jack M

    2011-05-01

    Post-transcriptional gene silencing (PTGS) agents such as antisense, ribozymes and RNA interference (RNAi) have great potential as therapeutics for a variety of eye diseases including retinal and macular degenerations, glaucoma, corneal degenerations, inflammatory and viral conditions. Despite their great potential and over thirty years of academic and corporate research only a single PTGS agent is currently approved for human therapy for a single disease. Substantial challenges exist to achieving both efficacious and safe PTGS agents. Efficacy, as measured in specific target mRNA and protein knockdown, depends upon a number of complex factors including the identification of rare regions of target mRNA accessibility, cellular co-localization of the PTGS agent in sufficient concentration with the target mRNA, and stability of the PTGS agent in the target cells in which it is delivered or expressed. Safety is commonly measured by lack of cytotoxicity or other deleterious cellular responses in cells in which the PTGS agent is delivered or expressed. To relieve major bottlenecks in RNA drug discovery novel, efficient, inexpensive, and rapid tools are needed to facilitate lead identification of the most efficacious PTGS agent, rational optimization of efficacy of the lead agent, and lead agent safety determinations. We have developed a technological platform using cell culture expression systems that permits lead identification and efficacy optimization of PTGS agents against arbitrary disease target mRNAs under relatively high throughput conditions. Here, we extend the technology platform to include PTGS safety determinations in cultured human cells that are expected to represent the common cellular housekeeping microenvironment. We developed a high throughput screening (HTS) cytotoxicity assay in 96-well plate format based around the SYTOX Green dye which is excluded from healthy viable cells and becomes substantially fluorescent only after entering cells and binding

  4. General guidelines for medically screening mixed population groups potentially exposed to nerve or vesicant agents

    SciTech Connect

    Watson, A.P.; Munro, N.B.; Sidell, F.R.; Leffingwell, S.S.

    1992-01-01

    A number of state and local planners have requested guidance on screening protocols and have expressed interest in sampling body fluids from exposed or potentially exposed individuals as a means of estimating agent dose. These guidelines have been developed to provide a clear statement that could be used by state and local emergency response personnel in the event of a nerve or vesicant agent incident resulting in off-post contamination; maximum protection from harm is the goal. The assumption is that any population group so exposed would be heterogeneous for age, gender, reproductive status, and state of health.

  5. New 1,4-anthracene-9,10-dione derivatives as potential anticancer agents.

    PubMed

    Zagotto, G; Supino, R; Favini, E; Moro, S; Palumbo, M

    2000-01-01

    The amino-substituted anthracene-9,10-dione (9,10-anthraquinone) derivatives represent one of the most important classes of potential anticancer agents. To better understand the basic rules governing DNA sequence specificity, we have recently synthesized a new class of D- and L-aminoacyl-anthraquinone derivatives. We have tested these new compounds as cytotoxic agents, and we have correlated their activity with the configuration of the chiral aminoacyl moiety. Molecular modeling studies have been performed to compare the test drugs in terms of steric overlapping.

  6. Involvement of phenazines and biosurfactants in biocontrol of Pythium myriotylum root rot on cocoyam by Pseudomonas sp. CMR12A

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas sp. CMR12a was isolated from the rhizosphere of the tropical tuber crop cocoyam and produces both phenazines and cyclic lipopeptide (CLP) biosurfactants. CMR12a was shown to be an efficient biocontrol agent of P. myriotylum on cocoyam. To assess the importance of phenazine and biosurfact...

  7. Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms.

    PubMed

    Bosmans, L; De Bruijn, I; De Mot, R; Rediers, H; Lievens, B

    2016-08-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens. We showed that when using the same medium, but different agar compositions, the activity of a bacterial antagonist against Agrobacterium was strongly affected. Consequently, results from in vitro screenings should be interpreted cautiously. PMID:27166668

  8. Evaluation of neutralized chemical agent identification sets (CAIS) for skin injury with an overview of the vesicant potential of agent degradation products.

    PubMed

    Olajos, E J; Olson, C T; Salem, H; Singer, A W; Hayes, T L; Menton, R G; Miller, T L; Rosso, T; MacIver, B

    1998-01-01

    Vesication and skin irritation studies were conducted in hairless guinea-pigs to determine the vesicant and skin irritation potential of chemically-neutralized Chemical Agent Identification Sets (CAIS). The CAIS are training items that contain chemical warfare-related material--sulfur mustard (HD), nitrogen mustard (HN) or lewisite (L)--and were declared obsolete in 1971. Animals were dosed topically with 'test article'--neat HD, 10% agent/chloroform solutions or product solutions (waste-streams) from neutralized CAIS--and evaluated for skin-damaging effects (gross and microscopic). Product solutions from the chemical neutralization of neat sulfur mustard resulted in microvesicle formation. All agent-dosed (HD or agent/chloroform solutions) sites manifested microblisters as well as other histopathological lesions of the skin. Waste-streams from the neutralization of agent (agent/chloroform or agent/charcoal) were devoid of vesicant activity. Cutaneous effects (erythema and edema) were consistent with the skin-injurious activity associated with the neutralizing reagent 1,3-dichloro-5,5-dimethylhydantoin (DCDMH). Chemical neutralization of CAIS was effective in eliminating/reducing the vesicant property of CAIS containing agent in chloroform or agent on charcoal but was inefficient in reducing the vesicant potential of CAIS containing neat sulfur mustard.

  9. Novel Hydrogel Material as a Potential Embolic Agent in Embolization Treatments

    NASA Astrophysics Data System (ADS)

    Zhou, Feng; Chen, Liming; An, Qingzhu; Chen, Liang; Wen, Ying; Fang, Fang; Zhu, Wei; Yi, Tao

    2016-08-01

    We report a novel graphene-oxide (GO) enhanced polymer hydrogel (GPH) as a promising embolic agent capable of treating cerebrovascular diseases and malignant tumors, using the trans-catheter arterial embolization (TAE) technique. Simply composed of GO and generation five poly(amidoamine) dendrimers (PAMAM-5), our rheology experiments reveal that GPH exhibits satisfactory mechanical strength, which resist the high pressures of blood flow. Subcutaneous experiments on Sprague-Dawley (SD) rats demonstrate the qualified biocompatibility of GPH. Finally, our in vivo experiments on New Zealand rabbits, which mix GPH with the X-ray absorbing contrast agent, Iohexol, reveal complete embolization of the artery. We also note that GPH shortens embolization time and exhibits low toxicity in follow-up experiments. Altogether, our study demonstrates that GPH has many advantages over the currently used embolic agents and has potential applications in clinical practice.

  10. Novel Hydrogel Material as a Potential Embolic Agent in Embolization Treatments

    PubMed Central

    Zhou, Feng; Chen, Liming; An, Qingzhu; Chen, Liang; Wen, Ying; Fang, Fang; Zhu, Wei; Yi, Tao

    2016-01-01

    We report a novel graphene-oxide (GO) enhanced polymer hydrogel (GPH) as a promising embolic agent capable of treating cerebrovascular diseases and malignant tumors, using the trans-catheter arterial embolization (TAE) technique. Simply composed of GO and generation five poly(amidoamine) dendrimers (PAMAM-5), our rheology experiments reveal that GPH exhibits satisfactory mechanical strength, which resist the high pressures of blood flow. Subcutaneous experiments on Sprague-Dawley (SD) rats demonstrate the qualified biocompatibility of GPH. Finally, our in vivo experiments on New Zealand rabbits, which mix GPH with the X-ray absorbing contrast agent, Iohexol, reveal complete embolization of the artery. We also note that GPH shortens embolization time and exhibits low toxicity in follow-up experiments. Altogether, our study demonstrates that GPH has many advantages over the currently used embolic agents and has potential applications in clinical practice. PMID:27561915

  11. The poultry red mite (Dermanyssus gallinae): a potential vector of pathogenic agents.

    PubMed

    Valiente Moro, Claire; De Luna, Carlos J; Tod, Alexander; Guy, Jonathan H; Sparagano, Olivier A E; Zenner, Lionel

    2009-06-01

    The poultry red mite, D. gallinae has been involved in the transmission of many pathogenic agents, responsible for serious diseases both in animals and humans. Nowadays, few effective methods are available to control the ectoparasite in poultry farms. Consequently, this is an emerging problem which must be taken into account to maintain good health in commercial egg production. This paper addresses the vector capacity of the ectoparasite with special emphasis on salmonellae, pathogenic agents responsible for many of the most important outbreaks of food-borne diseases worlwide. It has been experimentally shown that D. gallinae could act as a biological vector of S. enteritidis and natural carriage of these bacteria by the mite on poultry premises has also been reported. It was also found that D. gallinae carried other pathogens such as E. coli, Shigella sp., and Staphylococcus, thus increasing the list of pathogenic agents potentially transmitted by the mite.

  12. Novel Hydrogel Material as a Potential Embolic Agent in Embolization Treatments.

    PubMed

    Zhou, Feng; Chen, Liming; An, Qingzhu; Chen, Liang; Wen, Ying; Fang, Fang; Zhu, Wei; Yi, Tao

    2016-01-01

    We report a novel graphene-oxide (GO) enhanced polymer hydrogel (GPH) as a promising embolic agent capable of treating cerebrovascular diseases and malignant tumors, using the trans-catheter arterial embolization (TAE) technique. Simply composed of GO and generation five poly(amidoamine) dendrimers (PAMAM-5), our rheology experiments reveal that GPH exhibits satisfactory mechanical strength, which resist the high pressures of blood flow. Subcutaneous experiments on Sprague-Dawley (SD) rats demonstrate the qualified biocompatibility of GPH. Finally, our in vivo experiments on New Zealand rabbits, which mix GPH with the X-ray absorbing contrast agent, Iohexol, reveal complete embolization of the artery. We also note that GPH shortens embolization time and exhibits low toxicity in follow-up experiments. Altogether, our study demonstrates that GPH has many advantages over the currently used embolic agents and has potential applications in clinical practice. PMID:27561915

  13. Bio-protective microbial agents from rhizosphere eco-systems trigger plant defense responses provide protection against sheath blight disease in rice (Oryza sativa L.).

    PubMed

    Singh, Udai B; Malviya, Deepti; Wasiullah; Singh, Shailendra; Pradhan, Jatindra K; Singh, Bhanu P; Roy, Manish; Imram, Mohd; Pathak, Neelam; Baisyal, B M; Rai, Jai P; Sarma, B K; Singh, Rajiv K; Sharma, P K; Kaur, Saman Deep; Manna, M C; Sharma, Sushil K; Sharma, Arun K

    2016-11-01

    Sheath blight of rice (Oryza sativa L.) caused by Rhizoctonia solani is a major disease and attempts are being made to develop microbe based technologies for biocontrol of this pathogen. However, the mechanisms of biocontrol are not fully understood and still require indepth study in the backdrop of emerging concepts in biological systems. The present investigation was aimed at deciphering the mechanisms of biocontrol of sheath blight of rice employing Pseudomonas fluorescens and Trichoderma harzianum as model agents for biocontrol. Initially 25, 5 and 5 strains of P. fluorescens, T. viride and T. harzianum, respectively, were screened for their biocontrol potential. Out of which, six strains with higher value of percent inhibition of fungal mycelium in dual plate assay were selected. The role of P. fluorescens, T. viride and T. harzianum were investigated in induction and bioaccumulation of natural antioxidants, defence-related biomolecules and other changes in plant which lead not only to growth promotion but also protection from pathogenic stress conditions in rice. The two most promising strains, P. fluorescens PF-08 and T. harzianum UBSTH-501 selected on the basis of in planta evaluation, when applied individually or in combination, significantly enhanced the accumulation of defence-related biomolecules, enzymes and exhibited biocontrol potential against R. solani. A modified/newly developed delivery system was applied for the first time in the experiments involving inoculation of plants with both bioagents, viz. P. fluorescens PF-08 and T. harzianum UBSTH-501. Results suggested that application of P. fluorescens PF-08 and T. harzianum UBSTH-501 alone or in combination, not only helps in control of the disease but also increases plant growth along with reduction in application of toxic chemical pesticides.

  14. Bio-protective microbial agents from rhizosphere eco-systems trigger plant defense responses provide protection against sheath blight disease in rice (Oryza sativa L.).

    PubMed

    Singh, Udai B; Malviya, Deepti; Wasiullah; Singh, Shailendra; Pradhan, Jatindra K; Singh, Bhanu P; Roy, Manish; Imram, Mohd; Pathak, Neelam; Baisyal, B M; Rai, Jai P; Sarma, B K; Singh, Rajiv K; Sharma, P K; Kaur, Saman Deep; Manna, M C; Sharma, Sushil K; Sharma, Arun K

    2016-11-01

    Sheath blight of rice (Oryza sativa L.) caused by Rhizoctonia solani is a major disease and attempts are being made to develop microbe based technologies for biocontrol of this pathogen. However, the mechanisms of biocontrol are not fully understood and still require indepth study in the backdrop of emerging concepts in biological systems. The present investigation was aimed at deciphering the mechanisms of biocontrol of sheath blight of rice employing Pseudomonas fluorescens and Trichoderma harzianum as model agents for biocontrol. Initially 25, 5 and 5 strains of P. fluorescens, T. viride and T. harzianum, respectively, were screened for their biocontrol potential. Out of which, six strains with higher value of percent inhibition of fungal mycelium in dual plate assay were selected. The role of P. fluorescens, T. viride and T. harzianum were investigated in induction and bioaccumulation of natural antioxidants, defence-related biomolecules and other changes in plant which lead not only to growth promotion but also protection from pathogenic stress conditions in rice. The two most promising strains, P. fluorescens PF-08 and T. harzianum UBSTH-501 selected on the basis of in planta evaluation, when applied individually or in combination, significantly enhanced the accumulation of defence-related biomolecules, enzymes and exhibited biocontrol potential against R. solani. A modified/newly developed delivery system was applied for the first time in the experiments involving inoculation of plants with both bioagents, viz. P. fluorescens PF-08 and T. harzianum UBSTH-501. Results suggested that application of P. fluorescens PF-08 and T. harzianum UBSTH-501 alone or in combination, not only helps in control of the disease but also increases plant growth along with reduction in application of toxic chemical pesticides. PMID:27664749

  15. Functional Hyperbranched Polylysine as Potential Contrast Agent Probes for Magnetic Resonance Imaging.

    PubMed

    Zu, Guangyue; Liu, Min; Zhang, Kunchi; Hong, Shanni; Dong, Jingjin; Cao, Yi; Jiang, Bin; Luo, Liqiang; Pei, Renjun

    2016-06-13

    Researchers have never stopped questing contrast agents with high resolution and safety to overcome the drawbacks of small-molecule contrast agents in clinic. Herein, we reported the synthesis of gadolinium-based hyperbranched polylysine (HBPLL-DTPA-Gd), which was prepared by thermal polymerization of l-lysine via one-step polycondensation. After conjugating with folic acid, its potential application as MRI contrast agent was then evaluated. This contrast agent had no obvious cytotoxicity as verified by WST assay and H&E analysis. Compared to Gd(III)-diethylenetriaminepentaacetic acid (Gd-DTPA) (r1 = 4.3 mM(-1) s(-1)), the FA-HBPLL-DTPA-Gd exhibited much higher longitudinal relaxivity value (r1 = 13.44 mM(-1) s(-1)), up to 3 times higher than Gd-DTPA. The FA-HBPLL-DTPA-Gd showed significant signal intensity enhancement in the tumor region at various time points and provided a long time window for MR examination. The results illustrate that FA-HBPLL-DTPA-Gd will be a potential candidate for tumor-targeted MRI. PMID:27187578

  16. A phenazine-1-carboxylic acid producing polyextremophilic Pseudomonas chlororaphis (MCC2693) strain, isolated from mountain ecosystem, possesses biocontrol and plant growth promotion abilities.

    PubMed

    Jain, Rahul; Pandey, Anita

    2016-09-01

    The genus Pseudomonas is known to comprise a huge diversity of species with the ability to thrive in different habitats, including those considered as extreme environments. In the present study, a psychrotolerant, wide pH tolerant and halotolerant strain of Pseudomonas chlororaphis GBPI_507 (MCC2693), isolated from the wheat rhizosphere growing in a mountain location in Indian Himalayan Region (IHR), has been investigated for its antimicrobial potential with particular reference to phenazine production and plant growth promoting traits. GBPI_507 showed phenazine production at the temperatures ranged from 14 to 25°C. The benzene extracted compound identified as phenazine-1-carboxylic acid (PCA) through GC-MS exhibited antimicrobial properties against Gram positive bacteria and actinomycetes. The inhibition of phytopathogens in diffusible biocontrol assays was recorded in an order: Alternaria alternata>Phytophthora sp.>Fusarium solani>F. oxysporum. In volatile metabolite assays, all the pathogens, except Phytophthora sp. produced distorted colonies, characterized by restricted sporulation. The isolate also possessed other growth promoting and biocontrol traits including phosphate solubilization and production of siderophores, HCN, ammonia, and lytic enzymes (lipase and protease). Molecular studies confirmed production of PCA by the bacterium GBPI_507 through presence of phzCD and phzE genes in its genome. The polyextremophilic bacterial strain possesses various important characters to consider it as a potential agent for field applications, especially in mountain ecosystem, for sustainable and eco-friendly crop production.

  17. A phenazine-1-carboxylic acid producing polyextremophilic Pseudomonas chlororaphis (MCC2693) strain, isolated from mountain ecosystem, possesses biocontrol and plant growth promotion abilities.

    PubMed

    Jain, Rahul; Pandey, Anita

    2016-09-01

    The genus Pseudomonas is known to comprise a huge diversity of species with the ability to thrive in different habitats, including those considered as extreme environments. In the present study, a psychrotolerant, wide pH tolerant and halotolerant strain of Pseudomonas chlororaphis GBPI_507 (MCC2693), isolated from the wheat rhizosphere growing in a mountain location in Indian Himalayan Region (IHR), has been investigated for its antimicrobial potential with particular reference to phenazine production and plant growth promoting traits. GBPI_507 showed phenazine production at the temperatures ranged from 14 to 25°C. The benzene extracted compound identified as phenazine-1-carboxylic acid (PCA) through GC-MS exhibited antimicrobial properties against Gram positive bacteria and actinomycetes. The inhibition of phytopathogens in diffusible biocontrol assays was recorded in an order: Alternaria alternata>Phytophthora sp.>Fusarium solani>F. oxysporum. In volatile metabolite assays, all the pathogens, except Phytophthora sp. produced distorted colonies, characterized by restricted sporulation. The isolate also possessed other growth promoting and biocontrol traits including phosphate solubilization and production of siderophores, HCN, ammonia, and lytic enzymes (lipase and protease). Molecular studies confirmed production of PCA by the bacterium GBPI_507 through presence of phzCD and phzE genes in its genome. The polyextremophilic bacterial strain possesses various important characters to consider it as a potential agent for field applications, especially in mountain ecosystem, for sustainable and eco-friendly crop production. PMID:27394000

  18. Novel Routes for Improving Biocontrol Activity of Bacillus Based Bioinoculants

    PubMed Central

    Wu, Liming; Wu, Hui-Jun; Qiao, Junqing; Gao, Xuewen; Borriss, Rainer

    2015-01-01

    Biocontrol (BC) formulations prepared from plant-growth-promoting bacteria are increasingly applied in sustainable agriculture. Especially inoculants prepared from endospore-forming Bacillus strains have been proven as efficient and environmental-friendly alternative to chemical pesticides due to their long shelf life, which is comparable with that of agrochemicals. However, these formulations of the first generation are sometimes hampered in their action and do not fulfill in each case the expectations of the appliers. In this review we use the well-known plant-associated Bacillus amyloliquefaciens type strain FZB42 as example for the successful application of different techniques offered today by comparative, evolutionary and functional genomics, site-directed mutagenesis and strain construction including marker removal, for paving the way for preparing a novel generation of BC agents. PMID:26696998

  19. Commercialization of postharvest biocontrol: barriers and opportunities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The past twenty years has seen the field of postharvest biocontrol evolve from an unknown entity with one or two novel reports in the literature to a sophisticated science with strong research programs worldwide, hundreds of publications, patented technologies, and now several commercial products. ...

  20. Discovery of wall teichoic acid inhibitors as potential anti-MRSA β-lactam combination agents.

    PubMed

    Wang, Hao; Gill, Charles J; Lee, Sang H; Mann, Paul; Zuck, Paul; Meredith, Timothy C; Murgolo, Nicholas; She, Xinwei; Kales, Susan; Liang, Lianzhu; Liu, Jenny; Wu, Jin; Santa Maria, John; Su, Jing; Pan, Jianping; Hailey, Judy; Mcguinness, Debra; Tan, Christopher M; Flattery, Amy; Walker, Suzanne; Black, Todd; Roemer, Terry

    2013-02-21

    Innovative strategies are needed to combat drug resistance associated with methicillin-resistant Staphylococcus aureus (MRSA). Here, we investigate the potential of wall teichoic acid (WTA) biosynthesis inhibitors as combination agents to restore β-lactam efficacy against MRSA. Performing a whole-cell pathway-based screen, we identified a series of WTA inhibitors (WTAIs) targeting the WTA transporter protein, TarG. Whole-genome sequencing of WTAI-resistant isolates across two methicillin-resistant Staphylococci spp. revealed TarG as their common target, as well as a broad assortment of drug-resistant bypass mutants mapping to earlier steps of WTA biosynthesis. Extensive in vitro microbiological analysis and animal infection studies provide strong genetic and pharmacological evidence of the potential effectiveness of WTAIs as anti-MRSA β-lactam combination agents. This work also highlights the emerging role of whole-genome sequencing in antibiotic mode-of-action and resistance studies.

  1. The use of marine-derived bioactive compounds as potential hepatoprotective agents

    PubMed Central

    Nair, Dileep G; Weiskirchen, Ralf; Al-Musharafi, Salma K

    2015-01-01

    The marine environment may be explored as a rich source for novel drugs. A number of marine-derived compounds have been isolated and identified, and their therapeutic effects and pharmacological profiles are characterized. In the present review, we highlight the recent studies using marine compounds as potential hepatoprotective agents for the treatment of liver fibrotic diseases and discuss the proposed mechanisms of their activities. In addition, we discuss the significance of similar studies in Oman, where the rich marine life provides a potential for the isolation of novel natural, bioactive products that display therapeutic effects on liver diseases. PMID:25500871

  2. Synthesis and biological evaluation of pseudolaric acid B derivatives as potential immunosuppressive agents.

    PubMed

    Chen, Shou-Qiang; Wang, Jie; Zhao, Chuan; Sun, Qiang-Wen; Wang, Yi-Teng; Ai, Ting; Li, Tan; Gao, Ying; Wang, Huo; Chen, Hong

    2015-01-01

    Pseudolaric acid B (PB) derivatives with immunosuppressive activity were found by our group. In order to find potential immunosuppressive agents with high efficacy and low toxicity, a series of novel PB derivatives were synthesized and evaluated on their immunosuppressive activities. Most of the synthesized compounds were tested in vitro on murine T and B proliferation. In particular, compound 11 exhibited excellent inhibitory activity toward murine T cells (up to 19-fold enhancement compared to that of mycophenolatemofetil) and little cytotoxicity toward normal murine spleen cells. These experimental data demonstrated that some of these PB derivatives have great potential for future immunosuppressive studies.

  3. Cobalt Zinc Ferrite Nanoparticles as a Potential Magnetic Resonance Imaging Agent: An In vitro Study

    PubMed Central

    Ghasemian, Zeinab; Shahbazi-Gahrouei, Daryoush; Manouchehri, Sohrab

    2015-01-01

    Background: Magnetic Nanoparticles (MNP) have been used for contrast enhancement in Magnetic Resonance Imaging (MRI). In recent years, research on the use of ferrite nanoparticles in T2 contrast agents has shown a great potential application in MR imaging. In this work, Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Fe2O4-DMSA magnetic nanoparticles, CZF-MNPs and CZF-MNPs-DMSA, were investigated as MR imaging contrast agents. Methods: Cobalt zinc ferrite nanoparticles and their suitable coating, DMSA, were investigated under in vitro condition. Human prostate cancer cell lines (DU145 and PC3) with bare (uncoated) and coated magnetic nanoparticles were investigated as nano-contrast MR imaging agents. Results: Using T2-weighted MR images identified that signal intensity of bare and coated MNPs was enhanced with increasing concentration of MNPs in water. The values of 1/T2 relaxivity (r2) for bare and coated MNPs were found to be 88.46 and 28.80 (mM−1 s−1), respectively. Conclusion: The results show that bare and coated MNPs are suitable as T2-weighted MR imaging contrast agents. Also, the obtained r2/r1 values (59.3 and 50) for bare and coated MNPs were in agreement with the results of other previous relevant works. PMID:26140183

  4. Design, synthesis, molecular modeling, and biological evaluation of sulfanilamide-imines derivatives as potential anticancer agents.

    PubMed

    Mohamed, Sofian S; Tamer, Abdalkarem R; Bensaber, Salah M; Jaeda, Mousa I; Ermeli, Nouri B; Allafi, Aemen Ali; Mrema, Ibrahim A; Erhuma, Mabrouk; Hermann, Anton; Gbaj, Abdul M

    2013-09-01

    A series of sulfanilamide Schiff base derivatives (1 to 15) have been designed as potential antitubulin agents depending on the chemical structures of combretastatine A-4 and isoquinoline sulfamate (antimitotic agents under investigation). The designed compounds were synthesized by microwave chemical synthesis, their purity was confirmed by melting point and HPLC and chemical structures were determined by FT-IR, UV, and 1H and 13C-NMR spectroscopic techniques. The synthesized compounds have been docked in the colchicine binding site of β-tubulin using molecular modeling programs and the antitumor activities were screened on human breast and lung cancer cells by cell counting assay. Some tested compounds showed potent and selective activity against breast cancer (MCF-7) with IC50 range of 90 to 166 μM. With regarding broad-spectrum activity, compounds 4, 8, and 13 have shown potent antitumor activity against human breast and human lung cells with IC50 range of 96 to 140 μM. The obtained results suggest that the sulfanilamide Schiff base derivatives might potentially constitute an interesting novel class of anticancer agents, which deserve further studies. PMID:23708566

  5. Chitosan oligosaccharide based Gd-DTPA complex as a potential bimodal magnetic resonance imaging contrast agent.

    PubMed

    Huang, Yan; Cao, Juan; Zhang, Qi; Lu, Zheng-rong; Hua, Ming-qing; Zhang, Xiao-yan; Gao, Hu

    2016-01-01

    A new gadolinium diethylenetriamine pentaacetic acid (DTPA) complex (Gd-DTPA-DMABA-CS11) as a potential bimodal magnetic resonance imaging (MRI) contrast agent with fluorescence was synthesized. It was synthesized by the incorporation of 4-dimethylaminobenzaldehyde (DMABA) and chitosan oligosaccharide (CSn; n=11) with low polydispersity index to DTPA anhydride and then chelated with gadolinium chloride. The structure was characterized by Fourier transform infrared (FTIR), (1)H NMR, elemental analysis and size exclusion chromatography (SEC). MRI measurements in vitro were evaluated. The results indicated that Gd-DTPA-DMABA-CS11 provided higher molar longitudinal relaxivity (r1) (12.95mM(-1)·s(-1)) than that of commercial Gd-DTPA (3.63mM(-1)·s(-1)) at 0.5T. Gd-DTPA-DMABA-CS11 also emitted fluorescence, and the intensity was much stronger than that of Gd-DTPA. Therefore, it can be meanwhile used in fluorescent imaging for improving the sensitivity in clinic diagnosis. Gd-DTPA-DMABA-CS11 as a potential contrast agent is preliminarily stable in vitro. The results of thermodynamic action between Gd-DTPA-DMABA-CS11 and bovine serum albumin (BSA) illustrated that the binding process was exothermic and spontaneous, and the main force was van der Waals' interaction and hydrogen bond. The preliminary study suggested that Gd-DTPA-DMABA-CS11 could be used in both magnetic resonance and fluorescent imaging as a promising bimodal contrast agent.

  6. Xanthones from Mangosteen Extracts as Natural Chemopreventive Agents: Potential Anticancer Drugs

    PubMed Central

    Shan, T.; Ma, Q.; Guo, K.; Liu, J.; Li, W.; Wang, F.; Wu, E.

    2011-01-01

    Despite decades of research, the treatment and management of malignant tumors still remain a formidable challenge for public health. New strategies for cancer treatment are being developed, and one of the most promising treatment strategies involves the application of chemopreventive agents. The search for novel and effective cancer chemopreventive agents has led to the identification of various naturally occurring compounds. Xanthones, from the pericarp, whole fruit, heartwood, and leaf of mangosteen (Garcinia mangostana Linn., GML), are known to possess a wide spectrum of pharmacologic properties, including anti-oxidant, anti-tumor, anti-allergic, anti-inflammatory, anti-bacterial, anti-fungal, and anti-viral activities. The potential chemopreventive and chemotherapeutic activities of xanthones have been demonstrated in different stages of carcinogenesis (initiation, promotion, and progression) and are known to control cell division and growth, apoptosis, inflammation, and metastasis. Multiple lines of evidence from numerous in vitro and in vivo studies have confirmed that xanthones inhibit proliferation of a wide range of human tumor cell types by modulating various targets and signaling transduction pathways. Here we provide a concise and comprehensive review of preclinical data and assess the observed anticancer effects of xanthones, supporting its remarkable potential as an anticancer agent. PMID:21902651

  7. Synthesis and evaluation of novel tropane derivatives as potential PET imaging agents for the dopamine transporter

    PubMed Central

    Qiao, Hongwen; Zhu, Lin; Lieberman, Brian P.; Zha, Zhihao; Plössl, Karl; Kung, Hank F.

    2012-01-01

    A novel series of tropane derivatives containing a fluorinated tertiary amino or amide at the 2β position was synthesized, labeled with the positron-emitter fluorine-18 (T1/2 = 109.8 min), and tested as potential in vivo dopamine transporter (DAT) imaging agents. The corresponding chlorinated analogs were prepared and employed as precursors for radiolabeling leading to the fluorine-18-labeled derivatives via a one-step nucleophilic aliphatic substitution reaction. In vitro binding results showed that the 2β-amino compounds 6b, 6d and 7b displayed moderately high affinities to DAT (Ki < 10 nM). Biodistribution studies of [18F]6b and [18F]6d showed that the brain uptakes in rats were low. This is likely due to their low lipophilicities. Further structural modifications of these tropane derivatives will be needed to improve their in vivo properties as DAT imaging agents. PMID:22658558

  8. Isolation of Dickeya dadantii strains from potato disease and biocontrol by their bacteriophages

    PubMed Central

    Soleimani-Delfan, Abbas; Etemadifar, Zahra; Emtiazi, Giti; Bouzari, Majid

    2015-01-01

    One of the most economically important bacterial pathogens of plants and plant products is Dickeya dadantii. This bacterium causes soft rot disease in tubers and other parts of the potato and other plants of the Solanaceae family. The application of restricted host range bacteriophages as biocontrol agents has recently gained widespread interest. This study purposed to isolate the infectious agent of the potato and evaluate its biocontrol by bacteriophages. Two phytopathogenic strains were isolated from infected potatoes, identified based on biochemical and 16S rRNA gene sequencing, and submitted to GenBank as D. dadantii strain pis3 (accession no. HQ423668) and D. dadantii strain sip4 (accession no. HQ423669). Their bacteriophages were isolated from Caspian Sea water by enriching the water filtrate with D. dadantii strains as hosts using spot or overlay methods. On the basis of morphotypes, the isolated bacteriophages were identified as members of the Myoviridae and Siphoviridae families and could inhibit the growth of antibiotic resistant D. dadantii strains in culture medium. Moreover, in Dickeya infected plants treated with bacteriophage, no disease progression was detected. No significant difference was seen between phage-treated and control plants. Thus, isolated bacteriophages can be suggested for the biocontrol of plant disease caused by Dickeya strains. PMID:26413062

  9. Isolation of Dickeya dadantii strains from potato disease and biocontrol by their bacteriophages.

    PubMed

    Soleimani-Delfan, Abbas; Etemadifar, Zahra; Emtiazi, Giti; Bouzari, Majid

    2015-01-01

    One of the most economically important bacterial pathogens of plants and plant products is Dickeya dadantii. This bacterium causes soft rot disease in tubers and other parts of the potato and other plants of the Solanaceae family. The application of restricted host range bacteriophages as biocontrol agents has recently gained widespread interest. This study purposed to isolate the infectious agent of the potato and evaluate its biocontrol by bacteriophages. Two phytopathogenic strains were isolated from infected potatoes, identified based on biochemical and 16S rRNA gene sequencing, and submitted to GenBank as D. dadantii strain pis3 (accession no. HQ423668) and D. dadantii strain sip4 (accession no. HQ423669). Their bacteriophages were isolated from Caspian Sea water by enriching the water filtrate with D. dadantii strains as hosts using spot or overlay methods. On the basis of morphotypes, the isolated bacteriophages were identified as members of the Myoviridae and Siphoviridae families and could inhibit the growth of antibiotic resistant D. dadantii strains in culture medium. Moreover, in Dickeya infected plants treated with bacteriophage, no disease progression was detected. No significant difference was seen between phage-treated and control plants. Thus, isolated bacteriophages can be suggested for the biocontrol of plant disease caused by Dickeya strains.

  10. Stress tolerance and biocontrol performance of the yeast antagonist, Candida diversa, change with morphology transition.

    PubMed

    Li, Guangkun; Chi, Mengshan; Chen, Huizhen; Sui, Yuan; Li, Yan; Liu, Yongsheng; Zhang, Xiaojing; Sun, Zhiqiang; Liu, Guoqing; Wang, Qi; Liu, Jia

    2016-02-01

    As an eco-friendly management method, biological control of postharvest diseases, utilizing antagonistic yeasts, is a research topic receiving considerable attention. Detailed knowledge on the biology of yeast antagonists is crucial when considering their potential application and development as biocontrol products. Changes in the growth form, such as single-cell to pseudohyphae, have been associated with the mode of action in postharvest biocontrol yeasts. In this study, the antagonistic yeast, Candida diversa, reversibly shifted from a single-cell morphology on yeast peptone dextrose (YPD) medium with 2 % agar to a pseudohyphal morphology on YPD with 0.3 % agar. The tolerance of the pseudohyphal form to heat and oxidative stresses, as well as the biocontrol efficacy against Botrytis cinerea on apple and kiwifruit stored at 25 and 4 °C, was significantly higher as compared to the single-cell form. This study provides new information on the ability of C. diversa to change its morphology and the impact of the morphology shift on stress tolerance and biocontrol performance. PMID:26637302

  11. Stress tolerance and biocontrol performance of the yeast antagonist, Candida diversa, change with morphology transition.

    PubMed

    Li, Guangkun; Chi, Mengshan; Chen, Huizhen; Sui, Yuan; Li, Yan; Liu, Yongsheng; Zhang, Xiaojing; Sun, Zhiqiang; Liu, Guoqing; Wang, Qi; Liu, Jia

    2016-02-01

    As an eco-friendly management method, biological control of postharvest diseases, utilizing antagonistic yeasts, is a research topic receiving considerable attention. Detailed knowledge on the biology of yeast antagonists is crucial when considering their potential application and development as biocontrol products. Changes in the growth form, such as single-cell to pseudohyphae, have been associated with the mode of action in postharvest biocontrol yeasts. In this study, the antagonistic yeast, Candida diversa, reversibly shifted from a single-cell morphology on yeast peptone dextrose (YPD) medium with 2 % agar to a pseudohyphal morphology on YPD with 0.3 % agar. The tolerance of the pseudohyphal form to heat and oxidative stresses, as well as the biocontrol efficacy against Botrytis cinerea on apple and kiwifruit stored at 25 and 4 °C, was significantly higher as compared to the single-cell form. This study provides new information on the ability of C. diversa to change its morphology and the impact of the morphology shift on stress tolerance and biocontrol performance.

  12. Metal-oxo containing polymer nanobeads as potential contrast agents for magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Pablico, Michele Huelar

    Magnetic resonance imaging (MRI) has greatly revolutionized the way diseases are detected and treated, as it is a non-invasive imaging modality solely based on the interaction of radiowaves and hydrogen nuclei in the presence of an external magnetic field. It is widely used today for the diagnosis of diseases as it offers an efficient method of mapping structure and function of soft tissues in the body. Most MRI examinations utilize paramagnetic materials known as contrast agents, which enhance the MR signal by decreasing the longitudinal (T1) and transverse (T2) relaxation times of the surrounding water protons in biological systems. This results into increased signal intensity differences thereby allowing better interpretation and analysis of pathological tissues. Contrast agents function by lowering the T1 or lowering the T2, resulting into bright and dark contrasts, respectively. The most common MRI contrast agents that are in clinical use today are gadolinium chelates and superparamagnetic iron oxide nanoparticles, both of which have their own advantages in terms of contrast enhancement properties. In the past few years, however, there has been interest in utilizing metal-containing clusters for MRI contrast enhancement as these materials bridge the gap between the constrained structure and magnetic properties of the gadolinium chelates with the superparamagnetic behavior of the iron oxide nanoparticles. Recently, metallic clusters containing Mn and Fe metal centers have received increased attention mainly because of their potential for high spin states and benign nature. In the quest to further develop novel imaging agents, this research has focused on investigating the use of metal-oxo clusters as potential contrast agents for MRI. The primary goal of this project is to identify clusters that meet the following criteria: high paramagnetic susceptibility, water-soluble, stable, cheap, contain environmentally benign metals, and easily derivatized. This work is

  13. The biocontrol endophytic bacterium Pseudomonas fluorescens PICF7 induces systemic defense responses in aerial tissues upon colonization of olive roots

    PubMed Central

    Gómez-Lama Cabanás, Carmen; Schilirò, Elisabetta; Valverde-Corredor, Antonio; Mercado-Blanco, Jesús

    2014-01-01

    Pseudomonas fluorescens PICF7, a native olive root endophyte and effective biocontrol agent (BCA) against Verticillium wilt of olive, is able to trigger a broad range of defense responses in root tissues of this woody plant. In order to elucidate whether strain PICF7 also induces systemic defense responses in above-ground organs, aerial tissues of olive plants grown under non-gnotobiotic conditions were collected at different time points after root bacterization with this endophytic BCA. A suppression subtractive hybridization (SSH) cDNA library, enriched in up-regulated genes, was generated. This strategy enabled the identification of 376 ESTs (99 contigs and 277 singlets), many of them related to response to different stresses. Five ESTs, involved in defense responses, were selected to carry out time-course quantitative real-time PCR (qRT-PCR) experiments aiming to: (1) validate the induction of these genes, and (2) shed light on their expression pattern along time (from 1 to 15 days). Induction of olive genes potentially coding for lipoxygenase 2, catalase, 1-aminocyclopropane-1-carboxylate oxidase, and phenylananine ammonia-lyase was thus confirmed at some time points. Computational analysis also revealed that different transcription factors were up-regulated in olive aerial tissues (i.e., JERF, bHLH, WRKY), as previously reported for roots. Results confirmed that root colonization by this endophytic bacterium does not only trigger defense responses in this organ but also mounts a wide array of systemic defense responses in distant tissues (stems, leaves). This sheds light on how olive plants respond to the “non-hostile” colonization by a bacterial endophyte and how induced defense response can contribute to the biocontrol activity of strain PICF7. PMID:25250017

  14. Evaluation of a targeted nanobubble ultrasound contrast agent for potential tumor imaging

    NASA Astrophysics Data System (ADS)

    Li, Chunfang; Shen, Chunxu; Liu, Haijuan; Wu, Kaizhi; Zhou, Qibing; Ding, Mingyue

    2015-03-01

    Targeted nanobubbles have been reported to improve the contrast effect of ultrasound imaging due to the enhanced permeation and retention effects at tumor vascular leaks. In this work, the contrast enhancement abilities and the tumor targeting potential of a self-made VEGFR2-targeted nanobubble ultrasound contrast agent was evaluated in-vitro and in-vivo. Size distribution and zeta potential were assessed. Then the contrast-enhanced ultrasound imaging of the VEGFR2 targeted nanobubbles were evaluated with a custom-made experimental apparatus and in normal Wistar rats. Finally, the in-vivo tumor-targeting ability was evaluated on nude mice with subcutaneous tumor. The results showed that the target nanobubbles had uniform distribution with the average diameter of 208.1 nm, polydispersity index (PDI) of 0.411, and zeta potential of -13.21 mV. Significant contrast enhancement was observed in both in-vitro and in-vivo ultrasound imaging, demonstrating that the self-made target nanobubbles can enhance the contrast effect of ultrasound imaging efficiently. Targeted tumor imaging showed less promising result, due to the fact that the targeted nanobubbles arriving and permeating through tumor vessels were not many enough to produce significant enhancement. Future work will focus on exploring new imaging algorithm which is sensitive to targeted nanobubbles, so as to correctly detect the contrast agent, particularly at a low bubble concentration.

  15. Effects of Potential Therapeutic Agents on Copper Accumulations in Gill of Crassostrea virginica

    PubMed Central

    Luxama, Juan D.; Carroll, Margaret A.; Catapane, Edward J.

    2010-01-01

    Copper is an essential trace element for organisms, but when in excess, copper’s redox potential enhances oxyradical formation and increases cellular oxidative stress. Copper is a major pollutant in Jamaica Bay and other aquatic areas. Bivalves are filter feeders that accumulate heavy metals and other pollutants from their environment. Previously it was determined that seed from the bivalve Crassostrea virginica, transplanted from an oyster farm to Jamaica Bay readily accumulated copper and other pollutants into their tissues. In the present study we utilized Atomic Absorption Spectrometry to measure the uptake of copper into C. virginica gill in the presence and absence of three potential copper -blocking agents: diltiazem, lanthanum, and p-aminosalicyclic acid. Diltiazem and lanthanum are known calcium-channel blockers and p-aminosalicylic acid is an anti-infammarory agent with possible metal chelating properties. We also used the DMAB-Rhodanine histochemistry staining technique to confirm that copper was entering gill cells. Our result showed that diltiazem and p-aminosalicyclic acid reduced copper accumulations in the gill, while lanthanum did not. DMAB-Rhodanine histochemistry showed enhanced cellular copper staining in copper-treated samples and further demonstrated that diltiazem was able to reduce copper uptake. The accumulation of copper into oyster gill and its potential toxic effects could be of physiological significance to the growth and long term health of oysters and other marine animals living in a copper polluted environment. Identifying agents that block cellular copper uptake will further the understanding of metal transport mechanisms and may be beneficial in the therapeutic treatment of copper toxicity in humans. PMID:21841975

  16. Effects of Potential Therapeutic Agents on Copper Accumulations in Gill of Crassostrea virginica.

    PubMed

    Luxama, Juan D; Carroll, Margaret A; Catapane, Edward J

    2010-01-01

    Copper is an essential trace element for organisms, but when in excess, copper's redox potential enhances oxyradical formation and increases cellular oxidative stress. Copper is a major pollutant in Jamaica Bay and other aquatic areas. Bivalves are filter feeders that accumulate heavy metals and other pollutants from their environment. Previously it was determined that seed from the bivalve Crassostrea virginica, transplanted from an oyster farm to Jamaica Bay readily accumulated copper and other pollutants into their tissues. In the present study we utilized Atomic Absorption Spectrometry to measure the uptake of copper into C. virginica gill in the presence and absence of three potential copper -blocking agents: diltiazem, lanthanum, and p-aminosalicyclic acid. Diltiazem and lanthanum are known calcium-channel blockers and p-aminosalicylic acid is an anti-infammarory agent with possible metal chelating properties. We also used the DMAB-Rhodanine histochemistry staining technique to confirm that copper was entering gill cells. Our result showed that diltiazem and p-aminosalicyclic acid reduced copper accumulations in the gill, while lanthanum did not. DMAB-Rhodanine histochemistry showed enhanced cellular copper staining in copper-treated samples and further demonstrated that diltiazem was able to reduce copper uptake. The accumulation of copper into oyster gill and its potential toxic effects could be of physiological significance to the growth and long term health of oysters and other marine animals living in a copper polluted environment. Identifying agents that block cellular copper uptake will further the understanding of metal transport mechanisms and may be beneficial in the therapeutic treatment of copper toxicity in humans. PMID:21841975

  17. Impact of bacterial biocontrol agents on aflatoxin biosynthetic genes, aflD and aflR expression, and phenotypic aflatoxin B₁ production by Aspergillus flavus under different environmental and nutritional regimes.

    PubMed

    Al-Saad, Labeed A; Al-Badran, Adnan I; Al-Jumayli, Sami A; Magan, Naresh; Rodríguez, Alicia

    2016-01-18

    The objectives of this study were to examine the efficacy of four bacterial antagonists against Aspergillus flavus using 50:50 ratio of bacterial cells/conidia for the control of aflatoxin B1 (AFB1) production on two different nutritional matrices, nutrient and maize-based media at different water availabilities (0.98, 0.94 water activity (aw) on nutrient medium; 0.995, 0.98 aw on maize meal agar medium) at 35°C. The indicators of efficacy used were the relative expression of one structural and regulatory gene in the biosynthetic pathway (aflD and aflR respectively) and the production of AFB1. These studies showed that some of the bacterial species could significantly inhibit the relative expression of the aflD and aflR genes at both 0.98 and 0.94 aw on nutrient agar. On maize-based media some of the bacterial antagonists reduced the activity of both genes at 0.94 aw and some at 0.995 aw. However, the results for AFB1 production were not consistent with the effects on gene expression. Some bacterial species stimulated AFB1 production on both nutrient and maize-based media regardless of aw. However, some bacterial treatments did inhibit AFB1 production significantly when compared to the control. Overall, this study suggests that temporal studies are required on the biosynthetic genes under different environmental and nutritional conditions to evaluate the potential of antagonists to control AFB1. PMID:26513252

  18. Quercetin and rutin as potential sunscreen agents: determination of efficacy by an in vitro method.

    PubMed

    Choquenet, Benjamin; Couteau, Céline; Paparis, Eva; Coiffard, Laurence J M

    2008-06-01

    Given that flavonoids are known for their ultraviolet (UV)B photoprotective properties in plants that contain them, we chose to study quercetin (1) and rutin (2) as agents that could potentially be used in sunscreen products. These two substances proved to behave in similar ways. When incorporated in oil-in-water emulsions, at a concentration of 10% (w/w), 1 and 2 give sun protection factor (SPF) values similar to that of homosalate, a standard substance. These two flavonoids also provided a non-negligible level of photoprotection in the UVA range. When used in association with titanium dioxide, the SPF obtained was around 30.

  19. Antioxidants as potential medical countermeasures for chemical warfare agents and toxic industrial chemicals.

    PubMed

    McElroy, Cameron S; Day, Brian J

    2016-01-15

    The continuing horrors of military conflicts and terrorism often involve the use of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs). Many CWA and TIC exposures are difficult to treat due to the danger they pose to first responders and their rapid onset that can produce death shortly after exposure. While the specific mechanism(s) of toxicity of these agents are diverse, many are associated either directly or indirectly with increased oxidative stress in affected tissues. This has led to the exploration of various antioxidants as potential medical countermeasures for CWA/TIC exposures. Studies have been performed across a wide array of agents, model organisms, exposure systems, and antioxidants, looking at an almost equally diverse set of endpoints. Attempts at treating CWAs/TICs with antioxidants have met with mixed results, ranging from no effect to nearly complete protection. The aim of this commentary is to summarize the literature in each category for evidence of oxidative stress and antioxidant efficacy against CWAs and TICs. While there is great disparity in the data concerning methods, models, and remedies, the outlook on antioxidants as medical countermeasures for CWA/TIC management appears promising.

  20. Functional outcome after intracerebral haemorrhage - a review of the potential role of antiapoptotic agents.

    PubMed

    Salihu, Abubakar Tijjani; Muthuraju, Sangu; Idris, Zamzuri; Izaini Ghani, Abdul Rahman; Abdullah, Jafri Malin

    2016-04-01

    Intracerebral haemorrhage (ICH) is the second most common form of stroke and is associated with greater mortality and morbidity compared with ischaemic stroke. The current ICH management strategies, which mainly target primary injury mechanisms, have not been shown to improve patient's functional outcome. Consequently, multimodality treatment approaches that will focus on both primary and secondary pathophysiology have been suggested. During the last decade, a proliferation of experimental studies has demonstrated the role of apoptosis in secondary neuronal loss at the periphery of the clot after ICH. Subsequently, the value of certain antiapoptotic agents in reducing neuronal death and improving functional outcome following ICH was evaluated in animal models. Preliminary evidence from those studies strongly supports the potential role of antiapoptotic agents in reducing neuronal death and improving functional outcome after intracerebral haemorrhage. Expectedly, the ongoing and subsequent clinical trials will substantiate these findings and provide clear information on the most potent and safe antiapoptotic agents, their appropriate dosage, and temporal window of action, thereby making them suitable for the multimodality treatment approach. PMID:26641962

  1. Discovery of transition state factor Xa inhibitors as potential anticoagulant agents.

    PubMed

    Zhu, B Y; Huang, W; Su, T; Marlowe, C; Sinha, U; Hollenbach, S; Scarborough, R M

    2001-06-01

    Factor Xa is an attractive biological target in the discovery and development of either parenteral or orally active anticoagulant agents. Several strategies have been utilized at COR Therapeutics in the pursuit of tri-peptide based transition state mimetic factor Xa inhibitors with high aqueous solubility. Some of these inhibitors have displayed excellent in vitro potency in inhibiting factor Xa in the prothrombinase complex. More importantly, these compounds showed strong in vivo antithrombotic efficacy without significant bleeding complications in several animal thrombosis models. These results demonstrated that small molecule factor Xa inhibitors could be advantageous over Warfarin and LMWH. For the discovery and development of orally active anticoagulant agents, small organic molecules as reversible factor Xa inhibitors were explored. From a medicinal chemistry perspective, significant insight has been gained regarding the in vivo antithrombotic efficacy and pharmacokinetic behaviors of each class of factor Xa inhibitors. This review will focus on the design and discovery of transition state factor Xa inhibitors as potential parenteral anticoagulant agents. Several excellent comprehensive review articles on factor Xa inhibitors have appeared recently [1-4]. PMID:11899247

  2. Rosemary (Rosmarinus officinalis L.) Extract as a Potential Complementary Agent in Anticancer Therapy.

    PubMed

    González-Vallinas, Margarita; Reglero, Guillermo; Ramírez de Molina, Ana

    2015-01-01

    Cancer remains an important cause of mortality nowadays and, therefore, new therapeutic approaches are still needed. Rosemary (Rosmarinus officinalis L.) has been reported to possess antitumor activities both in vitro and in animal studies. Some of these activities were attributed to its major components, such as carnosic acid, carnosol, ursolic acid, and rosmarinic acid. Initially, the antitumor effects of rosemary were attributed to its antioxidant activity. However, in recent years, a lack of correlation between antioxidant and antitumor effects exerted by rosemary was reported, and different molecular mechanisms were related to its tumor inhibitory properties. Moreover, supported by the U.S. Food and Drug Administration and the European Food and Safety Authority, specific compositions of rosemary extract were demonstrated to be safe for human health and used as antioxidant additive in foods, suggesting the potential easy application of this agent as a complementary approach in cancer therapy. In this review, we aim to summarize the reported anticancer effects of rosemary, the demonstrated molecular mechanisms related to these effects and the interactions between rosemary and currently used anticancer agents. The possibility of using rosemary extract as a complementary agent in cancer therapy in comparison with its isolated components is discussed.

  3. Nucleic Acid Aptamers as Potential Therapeutic and Diagnostic Agents for Lymphoma

    PubMed Central

    Shum, Ka-To; Zhou, Jiehua; Rossi, John J.

    2014-01-01

    Lymphomas are cancers that arise from white blood cells and usually present as solid tumors. Treatment of lymphoma often involves chemotherapy, and can also include radiotherapy and/or bone marrow transplantation. There is an un-questioned need for more effective therapies and diagnostic tool for lymphoma. Aptamers are single stranded DNA or RNA oligonucleotides whose three-dimensional structures are dictated by their sequences. The immense diversity in function and structure of nucleic acids enable numerous aptamers to be generated through an iterative in vitro selection technique known as Systematic Evolution of Ligands by EXponential enrichment (SELEX). Aptamers have several biochemical properties that make them attractive tools for use as potential diagnostic and pharmacologic agents. Isolated aptamers may directly inhibit the function of target proteins, or they can also be formulated for use as delivery agents for other therapeutic or imaging cargoes. More complex aptamer identification methods, using whole cancer cells (Cell-SELEX), may identify novel targets and aptamers to affect them. This review focuses on recent advances in the use of nucleic acid aptamers as diagnostic and therapeutic agents and as targeted delivery carriers that are relevant to lymphoma. Some representative examples are also discussed. PMID:25057429

  4. Cardiocladius oliffi (Diptera: Chironomidae) as a potential biological control agent against Simulium squamosum (Diptera: Simuliidae)

    PubMed Central

    Boakye, Daniel A; Fokam, Eric; Ghansah, Anita; Amakye, Josef; Wilson, Michael D; Brown, Charles A

    2009-01-01

    Background The control of onchocerciasis in the African region is currently based mainly on the mass drug administration of ivermectin. Whilst this has been found to limit morbidity, it does not stop transmission. In the absence of a macrofilaricide, there is a need for an integrated approach for disease management, which includes vector control. Vector control using chemical insecticides is expensive to apply, and therefore the use of other measures such as biological control agents is needed. Immature stages of Simulium squamosum, reared in the laboratory from egg masses collected from the field at Boti Falls and Huhunya (River Pawnpawn) in Ghana, were observed to be attacked and fed upon by larvae of the chironomid Cardiocladius oliffi Freeman, 1956 (Diptera: Chironomidae). Methods Cardiocladius oliffi was successfully reared in the rearing system developed for S. damnosum s.l. and evaluated for its importance as a biological control agent in the laboratory. Results Even at a ratio of one C. oliffi to five S. squamosum, they caused a significant decrease in the number of adult S. squamosum emerging from the systems (treatments). Predation was confirmed by the amplification of Simulium DNA from C. oliffi observed to have fed on S. squamosum pupae. The study also established that the chironomid flies could successfully complete their development on a fish food diet only. Conclusion Cardiocladius oliffi has been demonstrated as potential biological control agent against S. squamosum. PMID:19393069

  5. Double layered hydroxides as potential anti-cancer drug delivery agents.

    PubMed

    Riaz, Ufana; Ashraf, S M

    2013-04-01

    The emergence of nanotechnology has changed the scenario of the medical world by revolutionizing the diagnosis, monitoring and treatment of cancer. This nanotechnology has been proved miraculous in detecting cancer cells, delivering chemotherapeutic agents and monitoring treatment from non-specific to highly targeted killing of tumor cells. In the past few decades, a number of inorganic materials have been investigated such as calcium phosphate, gold, carbon materials, silicon oxide, iron oxide, and layered double hydroxide (LDH) for examining their efficacy in targeting drug delivery. The reason behind the selection of these inorganic materials was their versatile and unique features efficient in drug delivery, such as wide availability, rich surface functionality, good biocompatibility, potential for target delivery, and controlled release of the drug from these inorganic nanomaterials. Although, the drug-LDH hybrids are found to be quite instrumental because of their application as advanced anti-cancer drug delivery systems, there has not been much research on them. This mini review is set to highlight the advancement made in the use of layered double hydroxides (LDHs) as anti-cancer drug delivery agents. Along with the advantages of LDHs as anti-cancer drug delivery agents, the process of interaction of some of the common anti-cancer drugs with LDH has also been discussed.

  6. Selection and evaluation of Debaryomyces hansenii isolates as potential bioprotective agents against toxigenic penicillia in dry-fermented sausages.

    PubMed

    Núñez, Félix; Lara, María S; Peromingo, Belén; Delgado, Josué; Sánchez-Montero, Lourdes; Andrade, María J

    2015-04-01

    Biocontrol using autochthonous Debaryomyces hansenii isolates is a potentially suitable strategy for inhibiting toxigenic moulds in dry-cured meat products. The antifungal activity of 280 D. hansenii isolated from dry-cured meat products as well as the mode of action of the most active isolates against toxigenic penicillia were evaluated in this work. A 13.9% of the D. hansenii isolates showed inhibitory activity in a radial inhibition assay. The effects on penicillia growth of both the cell-free culture filtrate and volatile compounds from active yeast isolates were analysed. Penicillia growth inhibition by D. hansenii was probably based on additive or synergistic effects of several inhibiting factors such as competition for nutrient and space, and production of soluble or volatile compounds. When four D. hansenii isolates were tested on dry-fermented sausage, two of them produced a significantly growth reduction of the ochratoxigenic Penicillium verrucosum, keeping its counts under the level considered as hazardous for the mycotoxin presence. Therefore, the use of these two D. hansenii isolates during the processing of dry-fermented meat product could be a promising tool to control toxigenic moulds in the meat industry.

  7. Selection and evaluation of Debaryomyces hansenii isolates as potential bioprotective agents against toxigenic penicillia in dry-fermented sausages.

    PubMed

    Núñez, Félix; Lara, María S; Peromingo, Belén; Delgado, Josué; Sánchez-Montero, Lourdes; Andrade, María J

    2015-04-01

    Biocontrol using autochthonous Debaryomyces hansenii isolates is a potentially suitable strategy for inhibiting toxigenic moulds in dry-cured meat products. The antifungal activity of 280 D. hansenii isolated from dry-cured meat products as well as the mode of action of the most active isolates against toxigenic penicillia were evaluated in this work. A 13.9% of the D. hansenii isolates showed inhibitory activity in a radial inhibition assay. The effects on penicillia growth of both the cell-free culture filtrate and volatile compounds from active yeast isolates were analysed. Penicillia growth inhibition by D. hansenii was probably based on additive or synergistic effects of several inhibiting factors such as competition for nutrient and space, and production of soluble or volatile compounds. When four D. hansenii isolates were tested on dry-fermented sausage, two of them produced a significantly growth reduction of the ochratoxigenic Penicillium verrucosum, keeping its counts under the level considered as hazardous for the mycotoxin presence. Therefore, the use of these two D. hansenii isolates during the processing of dry-fermented meat product could be a promising tool to control toxigenic moulds in the meat industry. PMID:25475274

  8. Efficacy of potential chemopreventive agents on rat colon aberrant crypt formation and progression.

    PubMed

    Wargovich, M J; Jimenez, A; McKee, K; Steele, V E; Velasco, M; Woods, J; Price, R; Gray, K; Kelloff, G J

    2000-06-01

    We assessed the effects of 78 potential chemopreventive agents in the F344 rat using two assays in which the inhibition of carcinogen-induced aberrant crypt foci (ACF) in the colon was the measure of efficacy. In both assays ACF were induced by the carcinogen azoxymethane (AOM) in F344 rats by two sequential weekly injections at a dose of 15 mg/kg. Two weeks after the last AOM injection, animals were evaluated for the number of aberrant crypts detected in methylene blue stained whole mounts of rat colon. In the initiation phase protocol agents were given during the period of AOM administration, whereas in the post-initiation assay the chemopreventive agent was introduced during the last 4 weeks of an 8 week assay, a time when ACF had progressed to multiple crypt clusters. The agents were derived from a priority listing based on reports of chemopreventive activity in the literature and/or efficacy data from in vitro models of carcinogenesis. During the initiation phase carboxyl amidoimidazole, p-chlorphenylacetate, chlorpheniramine maleate, D609, diclofenac, etoperidone, eicosatetraynoic acid, farnesol, ferulic acid, lycopene, meclizine, methionine, phenylhexylisothiocyanate, phenylbutyrate, piroxicam, 9-cis-retinoic acid, S-allylcysteine, taurine, tetracycline and verapamil were strong inhibitors of ACF. During the post-initiation phase aspirin, calcium glucarate, ketoprofen, piroxicam, 9-cis-retinoic acid, retinol and rutin inhibited the outgrowth of ACF into multiple crypt clusters. Based on these data, certain phytochemicals, antihistamines, non-steroidal anti-inflammatory drugs and retinoids show unique preclinical promise for chemoprevention of colon cancer, with the latter two drug classes particularly effective in the post-initiation phase of carcinogenesis. PMID:10837003

  9. Metal chelators coupled with nanoparticles as potential therapeutic agents for Alzheimer's disease

    PubMed Central

    Liu, Gang; Men, Ping; Perry, George; Smith, Mark A.

    2009-01-01

    Alzheimer's disease (AD) is a devastating neuro-degenerative disorder characterized by the progressive and irreversible loss of memory followed by complete dementia. Despite the disease's high prevalence and great economic and social burden, an explicative etiology or viable cure is not available. Great effort has been made to better understand the disease's pathogenesis, and to develop more effective therapeutic agents. However, success is greatly hampered by the presence of the blood-brain barrier that limits a large number of potential therapeutics from entering the brain. Nanoparticle-mediated drug delivery is one of the few valuable tools for overcoming this impediment and its application as a potential AD treatment shows promise. In this review, the current studies on nanoparticle delivery of chelation agents as possible therapeutics for AD are discussed because several metals are found excessive in the AD brain and may play a role in the disease development. Specifically, a novel approach involving transport of iron chelation agents into and out of the brain by nanoparticles is highlighted. This approach may provide a safer and more effective means of simultaneously reducing several toxic metals in the AD brain. It may also provide insights into the mechanisms of AD pathophysiology, and prove useful in treating other iron-associated neurodegenerative diseases such as Friedreich's ataxia, Parkinson's disease, Huntington's disease and Hallervorden-Spatz Syndrome. It is important to note that the use of nanoparticle-mediated transport to facilitate toxicant excretion from diseased sites in the body may advance nanoparticle technology, which is currently focused on targeted drug delivery for disease prevention and treatment. The application of nanoparticle-mediated drug transport in the treatment of AD is at its very early stages of development and, therefore, more studies are warranted. PMID:19936278

  10. Biological control agents elevate hantavirus by subsidizing deer mouse populations.

    PubMed

    Pearson, Dean E; Callaway, Ragan M

    2006-04-01

    Biological control of exotic invasive plants using exotic insects is practiced under the assumption that biological control agents are safe if they do not directly attack non-target species. We tested this assumption by evaluating the potential for two host-specific biological control agents (Urophora spp.), widely established in North America for spotted knapweed (Centaurea maculosa) control, to indirectly elevate Sin Nombre hantavirus by providing food subsidies to populations of deer mice (Peromyscus maniculatus), the primary reservoir for the virus. We show that seropositive deer mice (mice testing positive for hantavirus) were over three times more abundant in the presence of the biocontrol food subsidy. Elevating densities of seropositive mice may increase risk of hantavirus infection in humans and significantly alter hantavirus ecology. Host specificity alone does not ensure safe biological control. To minimize indirect risks to non-target species, biological control agents must suppress pest populations enough to reduce their own numbers. PMID:16623730

  11. Novel molecular hybrids of cinnamic acids and guanylhydrazones as potential antitubercular agents.

    PubMed

    Bairwa, Ranjeet; Kakwani, Manoj; Tawari, Nilesh R; Lalchandani, Jaya; Ray, M K; Rajan, M G R; Degani, Mariam S

    2010-03-01

    In an attempt to identify potential new agents active against tuberculosis, 20 novel phenylacrylamide derivatives incorporating cinnamic acids and guanylhydrazones were synthesized using microwave assisted synthesis. Activity of the synthesized compounds was evaluated using resazurin microtitre plate assay (REMA) against Mycobacterium tuberculosis H37Rv. Based on empirical structure-activity relationship data it was observed that both steric and electronic parameters play major role in the activity of this series of compounds. Compound 7s (2E)-N-((-2-(3,4-dimethoxybenzylidene) hydrazinyl) (imino) methyl)-3-(4-methoxyphenyl) acrylamide showed MIC of 6.49microM along with good safety profile of >50-fold in VERO cell line. Thus, this compound could act as a potential lead for further antitubercular studies.

  12. Potential Anti-HPV and Related Cancer Agents from Marine Resources: An Overview

    PubMed Central

    Wang, Shi-Xin; Zhang, Xiao-Shuang; Guan, Hua-Shi; Wang, Wei

    2014-01-01

    Recently, the studies on the prevention and treatment of human papillomavirus (HPV) which is closely related to the cervical cancer and other genital diseases are attracting more and more attention all over the world. Marine-derived polysaccharides and other bioactive compounds have been shown to possess a variety of anti-HPV and related cancer activities. This paper will review the recent progress in research on the potential anti-HPV and related cancer agents from marine resources. In particular, it will provide an update on the anti-HPV actions of heparinoid polysaccharides and bioactive compounds present in marine organisms, as well as the therapeutic vaccines relating to marine organisms. In addition, the possible mechanisms of anti-HPV actions of marine bioactive compounds and their potential for therapeutic application will also be summarized in detail. PMID:24705500

  13. Chemical warfare agent and biological toxin-induced pulmonary toxicity: could stem cells provide potential therapies?

    PubMed

    Angelini, Daniel J; Dorsey, Russell M; Willis, Kristen L; Hong, Charles; Moyer, Robert A; Oyler, Jonathan; Jensen, Neil S; Salem, Harry

    2013-01-01

    Chemical warfare agents (CWAs) as well as biological toxins present a significant inhalation injury risk to both deployed warfighters and civilian targets of terrorist attacks. Inhalation of many CWAs and biological toxins can induce severe pulmonary toxicity leading to the development of acute lung injury (ALI) as well as acute respiratory distress syndrome (ARDS). The therapeutic options currently used to treat these conditions are very limited and mortality rates remain high. Recent evidence suggests that human stem cells may provide significant therapeutic options for ALI and ARDS in the near future. The threat posed by CWAs and biological toxins for both civilian populations and military personnel is growing, thus understanding the mechanisms of toxicity and potential therapies is critical. This review will outline the pulmonary toxic effects of some of the most common CWAs and biological toxins as well as the potential role of stem cells in treating these types of toxic lung injuries.

  14. 4, 5-Dihydrooxazole-pyrazoline hybrids: Synthesis and their evaluation as potential antimalarial agents.

    PubMed

    Pandey, Ashutosh Kumar; Sharma, Supriya; Pandey, Minakshi; Alam, M Mumtaz; Shaquiquzzaman, M; Akhter, Mymoona

    2016-11-10

    A new series of oxazoline-pyrazoline hybrids (4a-p) were synthesized by condensation reaction of substituted oxazoline based chalcones (3a-m) and substituted hydrazines in methanol. Some of the compounds exhibited promising in vitro antimalarial activity for chloroquine sensitive CQ(S) (3D7) strain and chloroquine resistant CQ(R) (RKL9) strain. The most potent analogue 4i (IC50 0.322 μg/ml) exhibited significant in vivo antimalarial potential against Plasmodium berghei mouse model. The stable complex of 4i with hematin (1:1 stoichiometry) suggests that heme may be one possible target for these hybrid compounds. The study has revealed potential of title compounds as lead for the development of antimalarial agents. PMID:27494165

  15. Avena sativa (Oat), a potential neutraceutical and therapeutic agent: an overview.

    PubMed

    Singh, Rajinder; De, Subrata; Belkheir, Asma

    2013-01-01

    The aim of the present review article is to summarize the available information related to the availability, production, chemical composition, pharmacological activity, and traditional uses of Avena sativa to highlight its potential to contribute to human health. Oats are now cultivated worldwide and form an important dietary staple for the people in number of countries. Several varieties of oats are available. It is a rich source of protein, contains a number of important minerals, lipids, β-glucan, a mixed-linkage polysaccharide, which forms an important part of oat dietary fiber, and also contains various other phytoconstituents like avenanthramides, an indole alkaloid-gramine, flavonoids, flavonolignans, triterpenoid saponins, sterols, and tocols. Traditionally oats have been in use since long and are considered as stimulant, antispasmodic, antitumor, diuretic, and neurotonic. Oat possesses different pharmacological activities like antioxidant, anti-inflammatory, wound healing, immunomodulatory, antidiabetic, anticholesterolaemic, etc. A wide spectrum of biological activities indicates that oat is a potential therapeutic agent.

  16. Synthesis and biological evaluation of oxindole linked indolyl-pyrimidine derivatives as potential cytotoxic agents.

    PubMed

    Prajapti, Santosh Kumar; Nagarsenkar, Atulya; Guggilapu, Sravanthi Devi; Gupta, Keshav Kumar; Allakonda, Lingesh; Jeengar, Manish Kumar; Naidu, V G M; Babu, Bathini Nagendra

    2016-07-01

    In our endeavor towards the development of effective cytotoxic agents, a series of oxindole linked indolyl-pyrimidine derivatives were synthesized and characterized by IR, (1)H NMR, (13)C NMR and Mass spectral analysis. All the newly synthesized target compounds were assessed against PA-1 (ovarian), U-87MG (glioblastoma), LnCaP (prostate), and MCF-7 (Breast) cancer cell lines for their cytotoxic potential, with majority of them showing inhibitory activity at low micro-molar concentrations. Significantly, compound 8e was found to be most potent amongst all the tested compounds with an IC50 value of (2.43±0.29μM) on PA-1 cells. The influence of the most active cytotoxic compound 8e on the cell cycle distribution was assessed on the PA-1 cell line, exhibiting a cell cycle arrest at the G2/M phase. Moreover, acridine orange/ethidium bromide staining and annexin V binding assay confirmed that compound 8e can induce cell apoptosis in PA-1 cells. These preliminary results persuade further investigation on the synthesized compounds aiming to the development of potential cytotoxic agents.

  17. Design, synthesis, and evaluation of novel galloyl pyrrolidine derivatives as potential anti-tumor agents.

    PubMed

    Li, Xun; Li, Yalin; Xu, Wenfang

    2006-03-01

    A series of novel galloyl pyrrolidine derivatives were synthesized as potential anti-tumor agents. Their inhibiting activities on gelatinase (MMP-2 and -9) were tested with succinylated gelatin as the substrate. Structure-activity analyses demonstrate that introduction of longer and more flexible side chains at the C(4) position of the pyrrolidine ring brings higher activity against gelatinase. Free phenol hydroxyl group is more favorable than the methylated one, which confirms the important role of the phenol hydroxyl group when inhibitors interact with gelatinase. In particular, (2S,4S)-4-(3-(3,4-dimethoxyphenyl)acrylamido)-N-hydroxy-1-(3,4,5- trimethoxybenzoyl)pyrrolidine-2-carboxamide (18) stood out as the most attractive compound (IC(50) = 0.9 nM). The anti-metastasis model of mice bearing H(22) tumor cells was used to evaluate their anti-tumor activities in vivo. The assay in vivo revealed that most of these inhibitors displayed favorable inhibitory activities (inhibitory rate >35%) and no significant toxic effects were observed. The inhibition for 62.37% of 19 indicates the strategy used to design MMP inhibitors (MMPIs) of galloyl pyrrolidine derivatives as potential anti-tumor agents is promising.

  18. Development and thermodynamic evaluation of novel lipid raft stationary phase chromatography for screening potential antitumor agents.

    PubMed

    Tong, Shanshan; Sun, Chaonan; Cao, Xia; Zheng, Qianfeng; Zhang, Huiyun; Firempong, Caleb Kesse; Feng, Yingshu; Yang, Yan; Yu, Jiangnan; Xu, Ximing

    2014-12-01

    Novel lipid raft stationary phase chromatography (LRSC), with lipid rafts that contain abundant tropomyosin-related tyrosine kinase A receptors immobilized on the stationary phase, was developed for a high-throughput screening of potentially active antitumor agents. Lestaurtinib was used as a model compound to determine the operational parameters of the LRSC. Of all the factors considered, the particle size of column packing, the column temperature and the flow rate were of immense importance in determining the performance of the established LRSC system. In order to profoundly comprehend the binding interaction between the model drug and the receptors on the column, thermodynamic studies were employed. The results revealed that the interaction was spontaneous and exothermic, a typical enthalpy-driven process. Additionally, the primary forces were hydrogen bonding and van der Waals forces. In evaluating the applicability of the method, active extracts from Albizziae Cortex were screened out using the LRSC system under the optimized conditions. The bioactive components were successfully confirmed by the MTT assay. In conclusion, it could be said that the LRSC is a good model for screening potential antitumor agents because of its viability, rapid response and scalable features.

  19. Potential water-quality effects from iron cyanide anticaking agents in road salt

    SciTech Connect

    Paschka, M.G.; Ghosh, R.S.; Dzombak, D.A.

    1999-10-01

    Water-soluble iron cyanide compounds are widely used as anticaking agents in road salt, which creates potential contamination of surface and groundwater with these compounds when the salt dissolves and is washed off roads in runoff. This paper presents a summary of available information on iron cyanide use in road salt and its potential effects on water quality. Also, estimates of total cyanide concentrations in snow-melt runoff from roadways are presented as simple mass-balance calculations. Although available information does not indicate a widespread problem, it also is clear that the water-quality effects of cyanide in road salt have not been examined much. Considering the large, and increasing, volume of road salt used for deicing, studies are needed to determine levels of total and free cyanide in surface and groundwater adjacent to salt storage facilities and along roads with open drainage ditches. Results could be combined with current knowledge of the fate and transport of cyanide to assess water-quality effects of iron cyanide anticaking agents used in road salt.

  20. Effect of hypobaric hypoxia on cognitive functions and potential therapeutic agents.

    PubMed

    Muthuraju, Sangu; Pati, Soumya

    2014-12-01

    High altitude (HA), defined as approximately 3000-5000 m, considerably alters physiological and psychological parameters within a few hours. Chronic HA-mediated hypoxia (5000 m) results in permanent neuronal damage to the human brain that persists for one year or longer, even after returning to sea level. At HA, there is a decrease in barometric pressure and a consequential reduction in the partial pressure of oxygen (PO2), an extreme environmental condition to which humans are occasionally exposed. This condition is referred to as hypobaric hypoxia (HBH), which represents the most unfavourable characteristics of HA. HBH causes the disruption of oxygen availability to tissue. However, no review article has explored the impact of HBH on cognitive functions or the potential therapeutic agents for HBH. Therefore, the present review aimed to describe the impact of HBH on both physiological and cognitive functions, specifically learning and memory. Finally, the potential therapeutic agents for the treatment of HBH-induced cognitive impairment are discussed. PMID:25941462

  1. Silibinin, dexamethasone, and doxycycline as potential therapeutic agents for treating vesicant-inflicted ocular injuries

    SciTech Connect

    Tewari-Singh, Neera; Jain, Anil K.; Inturi, Swetha; Ammar, David A.; Agarwal, Chapla; Tyagi, Puneet; Kompella, Uday B.; Enzenauer, Robert W.; Petrash, J. Mark; Agarwal, Rajesh

    2012-10-01

    There are no effective and approved therapies against devastating ocular injuries caused by vesicating chemical agents sulfur mustard (SM) and nitrogen mustard (NM). Herein, studies were carried out in rabbit corneal cultures to establish relevant ocular injury biomarkers with NM for screening potential efficacious agents in laboratory settings. NM (100 nmol) exposure of the corneas for 2 h (cultured for 24 h), showed increases in epithelial thickness, ulceration, apoptotic cell death, epithelial detachment microbullae formation, and the levels of VEGF, cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9). Employing these biomarkers, efficacy studies were performed with agent treatments 2 h and every 4 h thereafter, for 24 h following NM exposure. Three agents were evaluated, including prescription drugs dexamethasone (0.1%; anti-inflammatory steroid) and doxycycline (100 nmol; antibiotic and MMP inhibitor) that have been studied earlier for treating vesicant-induced eye injuries. We also examined silibinin (100 μg), a non-toxic natural flavanone found to be effective in treating SM analog-induced skin injuries in our earlier studies. Treatments of doxycycline + dexamethasone, and silibinin were more effective than doxycycline or dexamethasone alone in reversing NM-induced epithelial thickening, microbullae formation, apoptotic cell death, and MMP-9 elevation. However, dexamethasone and silibinin alone were more effective in reversing NM-induced VEGF levels. Doxycycline, dexamethasone and silibinin were all effective in reversing NM-induced COX-2 levels. Apart from therapeutic efficacy of doxycycline and dexamethasone, these results show strong multifunctional efficacy of silibinin in reversing NM-induced ocular injuries, which could help develop effective and safe therapeutics against ocular injuries by vesicants. -- Highlights: ► Established injury biomarkers in rabbit corneal culture with nitrogen mustard (NM) ► This NM model is a cost effective

  2. Draft Genome Sequence of Biocontrol Agent Bacillus cereus UW85

    PubMed Central

    Lozano, Gabriel L.; Holt, Jonathan; Rasko, David A.; Thomas, Michael G.

    2016-01-01

    Bacillus cereus UW85 was isolated from a root of a field-grown alfalfa plant from Arlington, WI, and identified for its ability to suppress damping off, a disease caused by Phytophthora megasperma f. sp. medicaginis on alfalfa. Here, we report the draft genome sequence of B. cereus UW85, obtained by a combination of Sanger and Illumina sequencing. PMID:27587823

  3. Draft Genome Sequence of Biocontrol Agent Bacillus cereus UW85.

    PubMed

    Lozano, Gabriel L; Holt, Jonathan; Ravel, Jacques; Rasko, David A; Thomas, Michael G; Handelsman, Jo

    2016-01-01

    Bacillus cereus UW85 was isolated from a root of a field-grown alfalfa plant from Arlington, WI, and identified for its ability to suppress damping off, a disease caused by Phytophthora megasperma f. sp. medicaginis on alfalfa. Here, we report the draft genome sequence of B. cereus UW85, obtained by a combination of Sanger and Illumina sequencing. PMID:27587823

  4. The spined soldier bug: an important biocontrol agent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spined soldier bug, Podisus maculiventris (Heteroptera: Pentatomidae) is a generalist predator known to feed on over 75 insect species, several of which are important invasive insect pests. A substantial body of knowledge from our research studies on the ecology of this predator will be present...

  5. Responses of yeast biocontrol agents to environmental stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological control of postharvest diseases, utilizing wild species and strains of antagonistic yeasts, is a research topic that has received considerable attention in the literature over the past 30 years. In principle, it represents a promising alternative to chemical fungicides for the management...

  6. Draft Genome Sequence of Biocontrol Agent Bacillus cereus UW85.

    PubMed

    Lozano, Gabriel L; Holt, Jonathan; Ravel, Jacques; Rasko, David A; Thomas, Michael G; Handelsman, Jo

    2016-09-01

    Bacillus cereus UW85 was isolated from a root of a field-grown alfalfa plant from Arlington, WI, and identified for its ability to suppress damping off, a disease caused by Phytophthora megasperma f. sp. medicaginis on alfalfa. Here, we report the draft genome sequence of B. cereus UW85, obtained by a combination of Sanger and Illumina sequencing.

  7. Biocontrol agents fly through x-ray scans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 9/11, intensive baggage scans using various cabinet x-ray systems have become routine. The increased use of x-ray scanning has prompted many biological control practitioners to ask about possible harmful effects of x-ray radiation on shipments of live biological material, such as biological co...

  8. Correction: Polyol synthesis, functionalisation, and biocompatibility studies of superparamagnetic iron oxide nanoparticles as potential MRI contrast agents

    NASA Astrophysics Data System (ADS)

    Hachani, Roxanne; Lowdell, Mark; Birchall, Martin; Hervault, Aziliz; Mertz, Damien; Begin-Colin, Sylvie; Thanh, Nguy&Ecirtil; N. Thi&Cmb. B. Dot; Kim

    2016-02-01

    Correction for `Polyol synthesis, functionalisation, and biocompatibility studies of superparamagnetic iron oxide nanoparticles as potential MRI contrast agents' by Roxanne Hachani et al., Nanoscale, 2015, DOI: 10.1039/c5nr03867g.

  9. Correction: Polyol synthesis, functionalisation, and biocompatibility studies of superparamagnetic iron oxide nanoparticles as potential MRI contrast agents.

    PubMed

    Hachani, Roxanne; Lowdell, Mark; Birchall, Martin; Hervault, Aziliz; Mertz, Damien; Begin-Colin, Sylvie; Thanh, Nguyen Thi Kim

    2016-02-21

    Correction for 'Polyol synthesis, functionalisation, and biocompatibility studies of superparamagnetic iron oxide nanoparticles as potential MRI contrast agents' by Roxanne Hachani et al., Nanoscale, 2015, DOI: 10.1039/c5nr03867g. PMID:26823197

  10. Statistical media optimization for the biomass production of postharvest biocontrol yeast Rhodosporidium paludigenum.

    PubMed

    Wang, Peng; Liu, Xia; Wang, Yifei; Ruan, Hui; Zheng, XiaoDong

    2011-01-01

    A cane molasses-based medium for the biomass production of biocontrol agent Rhodosporidium paludigenum was statistically optimized. Molasses concentration (after pretreatment), yeast extract, and initial pH were identified by the Plackett-Burman design to show significant influence on the biomass production. The three factors were further optimized by central composite design and response-surface methodology. The statistical analysis indicated the optimum values of the variables were 89.98 g/L for cane molasses, 2.35 g/L for yeast extract and an initial pH of 8.48. The biomass yield at the optimal culture achieved 15.89 g/L in flask fermentation, which was 2.1 times higher than that at the initial NYDB medium. In a 10-L fermenter, 18.97 g/L of biomass was obtained after 36 hr of cultivation. Moreover, the biocontrol efficacy of the yeast was investigated after culture optimization. The results showed the yeast harvested in the optimal medium maintained its initial biocontrol properties by reducing the percentage of decayed apples to below 20%.

  11. Statistical media optimization for the biomass production of postharvest biocontrol yeast Rhodosporidium paludigenum.

    PubMed

    Wang, Peng; Liu, Xia; Wang, Yifei; Ruan, Hui; Zheng, XiaoDong

    2011-01-01

    A cane molasses-based medium for the biomass production of biocontrol agent Rhodosporidium paludigenum was statistically optimized. Molasses concentration (after pretreatment), yeast extract, and initial pH were identified by the Plackett-Burman design to show significant influence on the biomass production. The three factors were further optimized by central composite design and response-surface methodology. The statistical analysis indicated the optimum values of the variables were 89.98 g/L for cane molasses, 2.35 g/L for yeast extract and an initial pH of 8.48. The biomass yield at the optimal culture achieved 15.89 g/L in flask fermentation, which was 2.1 times higher than that at the initial NYDB medium. In a 10-L fermenter, 18.97 g/L of biomass was obtained after 36 hr of cultivation. Moreover, the biocontrol efficacy of the yeast was investigated after culture optimization. The results showed the yeast harvested in the optimal medium maintained its initial biocontrol properties by reducing the percentage of decayed apples to below 20%. PMID:21967338

  12. Biocontrol of tomato plant diseases caused by Fusarium solani using a new isolated Aspergillus tubingensis CTM 507 glucose oxidase.

    PubMed

    Kriaa, Mouna; Hammami, Inès; Sahnoun, Mouna; Azebou, Manel Cheffi; Triki, Mohamed Ali; Kammoun, Radhouane

    2015-10-01

    The present study focuses on the potential of glucose oxidase (GOD) as a promising biocontrol agent for fungal plant pathogens. In fact, a new GOD producing fungus was isolated and identified as an Aspergillus tubingensis. GOD (125 AU) has been found to inhibit Fusarium solani growth and spore production. Indeed, GOD caused the reduction of spores, the formation of chlamydospores, the induction of mycelial cords and the vacuolization of mycelium. In vivo assays, GOD acted as a curative treatment capable of protecting the tomato plants against F. solani diseases. In fact, the incidence was null in the curative treatment with GOD and it is around 45% for the preventive treatment. The optimization of media composition and culture conditions led to a 2.6-fold enhancement in enzyme activity, reaching 81.48U/mL. This study has demonstrated that GOD is a potent antifungal agent that could be used as a new biofungicide to protect plants from diseases. PMID:26299190

  13. Exploring simvastatin, an antihyperlipidemic drug, as a potential topical antibacterial agent.

    PubMed

    Thangamani, Shankar; Mohammad, Haroon; Abushahba, Mostafa F N; Hamed, Maha I; Sobreira, Tiago J P; Hedrick, Victoria E; Paul, Lake N; Seleem, Mohamed N

    2015-01-01

    The rapid rise of bacterial resistance to traditional antibiotics combined with the decline in discovery of novel antibacterial agents has created a global public health crisis. Repurposing existing drugs presents an alternative strategy to potentially expedite the discovery of new antimicrobial drugs. The present study demonstrates that simvastatin, an antihyperlipidemic drug exhibited broad-spectrum antibacterial activity against important Gram-positive (including methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative pathogens (once the barrier imposed by the outer membrane was permeabilized). Proteomics and macromolecular synthesis analyses revealed that simvastatin inhibits multiple biosynthetic pathways and cellular processes in bacteria, including selective interference of bacterial protein synthesis. This property appears to assist in simvastatin's ability to suppress production of key MRSA toxins (α-hemolysin and Panton-Valentine leucocidin) that impair healing of infected skin wounds. A murine MRSA skin infection experiment confirmed that simvastatin significantly reduces the bacterial burden and inflammatory cytokines in the infected wounds. Additionally, simvastatin exhibits excellent anti-biofilm activity against established staphylococcal biofilms and demonstrates the ability to be combined with topical antimicrobials currently used to treat MRSA skin infections. Collectively the present study lays the foundation for further investigation of repurposing simvastatin as a topical antibacterial agent to treat skin infections. PMID:26553420

  14. Bismuth@US-tubes as a Potential Contrast Agent for X-ray Imaging Applications

    PubMed Central

    Rivera, Eladio J.; Tran, Lesa A.; Hernández-Rivera, Mayra; Yoon, Diana; Mikos, Antonios G.; Rusakova, Irene A.; Cheong, Benjamin Y.; Cabreira-Hansen, Maria da Graça; Willerson, James T.; Perin, Emerson C.; Wilson, Lon J.

    2013-01-01

    The encapsulation of bismuth as BiOCl/Bi2O3 within ultra-short (ca. 50 nm) single-walled carbon nanocapsules (US-tubes) has been achieved. The Bi@US-tubes have been characterized by high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Bi@US-tubes have been used for intracellular labeling of pig bone marrow-derived mesenchymal stem cells (MSCs) to show high X-ray contrast in computed tomography (CT) cellular imaging for the first time. The relatively high contrast is achieved with low bismuth loading (2.66% by weight) within the US-tubes and without compromising cell viability. X-ray CT imaging of Bi@US-tubes-labeled MSCs showed a nearly two-fold increase in contrast enhancement when compared to unlabeled MSCs in a 100 kV CT clinical scanner. The CT signal enhancement from the Bi@US-tubes is 500 times greater than polymer-coated Bi2S3 nanoparticles and several-fold that of any clinical iodinated contrast agent (CA) at the same concentration. Our findings suggest that the Bi@US-tubes can be used as a potential new class of X-ray CT agent for stem cell labeling and possibly in vivo tracking. PMID:24288589

  15. Theranostic Au Cubic Nano-aggregates as Potential Photoacoustic Contrast and Photothermal Therapeutic Agents

    PubMed Central

    Hu, Juan; Zhu, Xianglong; Li, Hui; Zhao, Zhenghuan; Chi, Xiaoqin; Huang, Guoming; Huang, Dengtong; Liu, Gang; Wang, Xiaomin; Gao, Jinhao

    2014-01-01

    Multifunctional nanostructures combining diagnosis and therapy modalities into one entity have drawn much attention in the biomedical applications. Herein, we report a simple and cost-effective method to synthesize a novel cubic Au nano-aggregates structure with edge-length of 80 nm (Au-80 CNAs), which display strong near-infrared (NIR) absorption, excellent water-solubility, good photothermal stability, and high biocompatibility. Under 808 nm laser irradiation for 5 min, the temperature of the solution containing Au-80 CNAs (100 μg/mL) increased by ~38 °C. The in vitro and in vivo studies demonstrated that Au-80 CNAs could act as both photothermal therapeutic (PTT) agents and photoacoustic imaging (PAI) contrast agents, indicating that the only one nano-entity of Au-80 CNAs shows great potentials for theranostic applications. Moreover, this facile and cost-effective synthetic method provides a new strategy to prepare stable Au nanomaterials with excellent optical properties for biomedical applications. PMID:24672584

  16. Potential Molecular Targets for Narrow-Spectrum Agents to Combat Mycoplasma pneumoniae Infection and Disease.

    PubMed

    Balish, Mitchell F; Distelhorst, Steven L

    2016-01-01

    As Mycoplasma pneumoniae macrolide resistance grows and spreads worldwide, it is becoming more important to develop new drugs to prevent infection or limit disease. Because other mycoplasma species have acquired resistance to other classes of antibiotics, it is reasonable to presume that M. pneumoniae can do the same, so switching to commonly used antibiotics like fluoroquinolones will not result in forms of therapy with long-term utility. Moreover, broad-spectrum antibiotics can have serious consequences for the patient, as these drugs may have severe impacts on the natural microbiota of the individual, compromising the health of the patient either short-term or long-term. Therefore, developing narrow-spectrum antibiotics that effectively target only M. pneumoniae and no more than a small portion of the microbiota is likely to yield impactful, positive results that can be used perhaps indefinitely to combat M. pneumoniae. Development of these agents requires a deep understanding of the basic biology of M. pneumoniae, in many areas deeper than what is currently known. In this review, we discuss potential targets for new, narrow-spectrum agents and both the positive and negative aspects of selecting these targets, which include toxic molecules, metabolic pathways, and attachment and motility. By gathering this information together, we anticipate that it will be easier for researchers to evaluate topics of priority for study of M. pneumoniae. PMID:26941728

  17. Understanding Virulence in the Brucellae and Francisellae: Towards Efficacious Treatments for Two Potential Biothreat Agents

    SciTech Connect

    Rasley, A; Parsons, D A; El-Etr, S; Roux, C; Tsolis, R

    2009-12-30

    Francisella tularensis, Yersinia pestis and Brucellae species are highly infectious pathogens classified as select agents by the Centers for Disease Control and Prevention (CDC) with the potential for use in bioterrorism attacks. These organisms are known to be facultative intracellular pathogens that preferentially infect human monocytes. As such, understanding how the host responds to infection with these organisms is paramount in detecting and combating human disease. We have compared the ability of fully virulent strains of each pathogen and their non-pathogenic near neighbors to enter and survive inside the human monocytic cell line THP-1 and have quantified the cellular response to infection with the goal of identifying both unique and common host response patterns. We expanded the scope of these studies to include experiments with pathogenic and non-pathogenic strains of Y. pestis, the causative agent of plague. Nonpathogenic strains of each organism were impaired in their ability to survive intracellularly compared with their pathogenic counterparts. Furthermore, infection of THP-1 cells with pathogenic strains of Y. pestis and F. tularensis resulted in marked increases in the secretion of the inflammatory chemokines IL-8, RANTES, and MIP-1{beta}. In contrast, B. melitensis infection failed to elicit any significant increases in a panel of cytokines tested. These differences may underscore distinct strategies in pathogenic mechanisms employed by these pathogens.

  18. Exploring simvastatin, an antihyperlipidemic drug, as a potential topical antibacterial agent

    PubMed Central

    Thangamani, Shankar; Mohammad, Haroon; Abushahba, Mostafa F. N.; Hamed, Maha I.; Sobreira, Tiago J. P.; Hedrick, Victoria E.; Paul, Lake N.; Seleem, Mohamed N.

    2015-01-01

    The rapid rise of bacterial resistance to traditional antibiotics combined with the decline in discovery of novel antibacterial agents has created a global public health crisis. Repurposing existing drugs presents an alternative strategy to potentially expedite the discovery of new antimicrobial drugs. The present study demonstrates that simvastatin, an antihyperlipidemic drug exhibited broad-spectrum antibacterial activity against important Gram-positive (including methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative pathogens (once the barrier imposed by the outer membrane was permeabilized). Proteomics and macromolecular synthesis analyses revealed that simvastatin inhibits multiple biosynthetic pathways and cellular processes in bacteria, including selective interference of bacterial protein synthesis. This property appears to assist in simvastatin’s ability to suppress production of key MRSA toxins (α-hemolysin and Panton-Valentine leucocidin) that impair healing of infected skin wounds. A murine MRSA skin infection experiment confirmed that simvastatin significantly reduces the bacterial burden and inflammatory cytokines in the infected wounds. Additionally, simvastatin exhibits excellent anti-biofilm activity against established staphylococcal biofilms and demonstrates the ability to be combined with topical antimicrobials currently used to treat MRSA skin infections. Collectively the present study lays the foundation for further investigation of repurposing simvastatin as a topical antibacterial agent to treat skin infections. PMID:26553420

  19. Amphiphilic cationic β(3R3)-peptides: membrane active peptidomimetics and their potential as antimicrobial agents.

    PubMed

    Mosca, Simone; Keller, Janos; Azzouz, Nahid; Wagner, Stefanie; Titz, Alexander; Seeberger, Peter H; Brezesinski, Gerald; Hartmann, Laura

    2014-05-12

    We introduce a novel class of membrane active peptidomimetics, the amphiphilic cationic β(3R3)-peptides, and evaluate their potential as antimicrobial agents. The design criteria, the building block and oligomer synthesis as well as a detailed structure-activity relationship (SAR) study are reported. Specifically, infrared reflection absorption spectroscopy (IRRAS) was employed to investigate structural features of amphiphilic cationic β(3R3)-peptide sequences at the hydrophobic/hydrophilic air/liquid interface. Furthermore, Langmuir monolayers of anionic and zwitterionic phospholipids have been used to model the interactions of amphiphilic cationic β(3R3)-peptides with prokaryotic and eukaryotic cellular membranes in order to predict their membrane selectivity and elucidate their mechanism of action. Lastly, antimicrobial activity was tested against Gram-positive M. luteus and S. aureus as well as against Gram-negative E. coli and P. aeruginosa bacteria along with testing hemolytic activity and cytotoxicity. We found that amphiphilic cationic β(3R3)-peptide sequences combine high and selective antimicrobial activity with exceptionally low cytotoxicity in comparison to values reported in the literature. Overall, this study provides further insights into the SAR of antimicrobial peptides and peptidomimetics and indicates that amphiphilic cationic β(3R3)-peptides are strong candidates for further development as antimicrobial agents with high therapeutic index.

  20. Pharmacophore modeling and in silico toxicity assessment of potential anticancer agents from African medicinal plants.

    PubMed

    Ntie-Kang, Fidele; Simoben, Conrad Veranso; Karaman, Berin; Ngwa, Valery Fuh; Judson, Philip Neville; Sippl, Wolfgang; Mbaze, Luc Meva'a

    2016-01-01

    Molecular modeling has been employed in the search for lead compounds of chemotherapy to fight cancer. In this study, pharmacophore models have been generated and validated for use in virtual screening protocols for eight known anticancer drug targets, including tyrosine kinase, protein kinase B β, cyclin-dependent kinase, protein farnesyltransferase, human protein kinase, glycogen synthase kinase, and indoleamine 2,3-dioxygenase 1. Pharmacophore models were validated through receiver operating characteristic and Güner-Henry scoring methods, indicating that several of the models generated could be useful for the identification of potential anticancer agents from natural product databases. The validated pharmacophore models were used as three-dimensional search queries for virtual screening of the newly developed AfroCancer database (~400 compounds from African medicinal plants), along with the Naturally Occurring Plant-based Anticancer Compound-Activity-Target dataset (comprising ~1,500 published naturally occurring plant-based compounds from around the world). Additionally, an in silico assessment of toxicity of the two datasets was carried out by the use of 88 toxicity end points predicted by the Lhasa's expert knowledge-based system (Derek), showing that only an insignificant proportion of the promising anticancer agents would be likely showing high toxicity profiles. A diversity study of the two datasets, carried out using the analysis of principal components from the most important physicochemical properties often used to access drug-likeness of compound datasets, showed that the two datasets do not occupy the same chemical space. PMID:27445461

  1. Pseudopterosin A: Protection of Synaptic Function and Potential as a Neuromodulatory Agent

    PubMed Central

    Caplan, Stacee Lee; Zheng, Bo; Dawson-Scully, Ken; White, Catherine A.; West, Lyndon M.

    2016-01-01

    Natural products have provided an invaluable source of inspiration in the drug discovery pipeline. The oceans are a vast source of biological and chemical diversity. Recently, this untapped resource has been gaining attention in the search for novel structures and development of new classes of therapeutic agents. Pseudopterosins are group of marine diterpene glycosides that possess an array of potent biological activities in several therapeutic areas. Few studies have examined pseudopterosin effects during cellular stress and, to our knowledge, no studies have explored their ability to protect synaptic function. The present study probes pseudopterosin A (PsA) for its neuromodulatory properties during oxidative stress using the fruit fly, Drosophila melanogaster. We demonstrate that oxidative stress rapidly reduces neuronal activity, resulting in the loss of neurotransmission at a well-characterized invertebrate synapse. PsA mitigates this effect and promotes functional tolerance during oxidative stress by prolonging synaptic transmission in a mechanism that differs from scavenging activity. Furthermore, the distribution of PsA within mammalian biological tissues following single intravenous injection was investigated using a validated bioanalytical method. Comparable exposure of PsA in the mouse brain and plasma indicated good distribution of PsA in the brain, suggesting its potential as a novel neuromodulatory agent. PMID:26978375

  2. Potential Molecular Targets for Narrow-Spectrum Agents to Combat Mycoplasma pneumoniae Infection and Disease

    PubMed Central

    Balish, Mitchell F.; Distelhorst, Steven L.

    2016-01-01

    As Mycoplasma pneumoniae macrolide resistance grows and spreads worldwide, it is becoming more important to develop new drugs to prevent infection or limit disease. Because other mycoplasma species have acquired resistance to other classes of antibiotics, it is reasonable to presume that M. pneumoniae can do the same, so switching to commonly used antibiotics like fluoroquinolones will not result in forms of therapy with long-term utility. Moreover, broad-spectrum antibiotics can have serious consequences for the patient, as these drugs may have severe impacts on the natural microbiota of the individual, compromising the health of the patient either short-term or long-term. Therefore, developing narrow-spectrum antibiotics that effectively target only M. pneumoniae and no more than a small portion of the microbiota is likely to yield impactful, positive results that can be used perhaps indefinitely to combat M. pneumoniae. Development of these agents requires a deep understanding of the basic biology of M. pneumoniae, in many areas deeper than what is currently known. In this review, we discuss potential targets for new, narrow-spectrum agents and both the positive and negative aspects of selecting these targets, which include toxic molecules, metabolic pathways, and attachment and motility. By gathering this information together, we anticipate that it will be easier for researchers to evaluate topics of priority for study of M. pneumoniae. PMID:26941728

  3. A Novel Potential Positron Emission Tomography Imaging Agent for Vesicular Monoamine Transporter Type 2.

    PubMed

    Huang, Zih-Rou; Tsai, Chia-Ling; Huang, Ya-Yao; Shiue, Chyng-Yann; Tzen, Kai-Yuan; Yen, Ruoh-Fang; Hsin, Ling-Wei

    2016-01-01

    In the early 1990s, 9-(+)-11C-dihydrotetrabenazine (9-(+)-11C-DTBZ) was shown to be a useful positron emission tomography (PET) imaging agent for various neurodegenerative disorders. Here, we described the radiosynthesis and evaluation of the 9-(+)-11C-DTBZ analog, 10-(+)-11C-DTBZ, as a vesicular monoamine transporter 2 (VMAT2) imaging agent and compare it with 9-(+)-11C-DTBZ. 10-(+)-11C-DTBZ was obtained by 11C-MeI methylation with its 10 hydroxy precursor in the presence of 5 M NaOH. It had a slightly better average radiochemical yield of 35.3 ± 3.6% (decay-corrected to end of synthesis (EOS)) than did 9-(+)-11C-DTBZ (30.5 ± 2.3%). MicroPET studies showed that 10-(+)-11C-DTBZ had a striatum-to-cerebellum ratio of 3.74 ± 0.21 at 40 min post-injection, while the ratio of 9-(+)-11C-DTBZ was 2.50 ± 0.33. This indicated that 10-(+)-11C-DTBZ has a higher specific uptake in VMAT2-rich brain regions, and 10-(+)-11C-DTBZ may be a potential VMAT2 radioligand. Our experiment is the first study of 10-(+)-11C-DTBZ to include dynamic brain distribution in rat brains. PMID:27612194

  4. A Novel Potential Positron Emission Tomography Imaging Agent for Vesicular Monoamine Transporter Type 2

    PubMed Central

    Huang, Zih-Rou; Tsai, Chia-Ling; Huang, Ya-Yao; Shiue, Chyng-Yann; Tzen, Kai-Yuan; Yen, Ruoh-Fang; Hsin, Ling-Wei

    2016-01-01

    In the early 1990s, 9-(+)-11C-dihydrotetrabenazine (9-(+)-11C-DTBZ) was shown to be a useful positron emission tomography (PET) imaging agent for various neurodegenerative disorders. Here, we described the radiosynthesis and evaluation of the 9-(+)-11C-DTBZ analog, 10-(+)-11C-DTBZ, as a vesicular monoamine transporter 2 (VMAT2) imaging agent and compare it with 9-(+)-11C-DTBZ. 10-(+)-11C-DTBZ was obtained by 11C-MeI methylation with its 10 hydroxy precursor in the presence of 5 M NaOH. It had a slightly better average radiochemical yield of 35.3 ± 3.6% (decay-corrected to end of synthesis (EOS)) than did 9-(+)-11C-DTBZ (30.5 ± 2.3%). MicroPET studies showed that 10-(+)-11C-DTBZ had a striatum-to-cerebellum ratio of 3.74 ± 0.21 at 40 min post-injection, while the ratio of 9-(+)-11C-DTBZ was 2.50 ± 0.33. This indicated that 10-(+)-11C-DTBZ has a higher specific uptake in VMAT2-rich brain regions, and 10-(+)-11C-DTBZ may be a potential VMAT2 radioligand. Our experiment is the first study of 10-(+)-11C-DTBZ to include dynamic brain distribution in rat brains. PMID:27612194

  5. Pharmacophore modeling and in silico toxicity assessment of potential anticancer agents from African medicinal plants

    PubMed Central

    Ntie-Kang, Fidele; Simoben, Conrad Veranso; Karaman, Berin; Ngwa, Valery Fuh; Judson, Philip Neville; Sippl, Wolfgang; Mbaze, Luc Meva’a

    2016-01-01

    Molecular modeling has been employed in the search for lead compounds of chemotherapy to fight cancer. In this study, pharmacophore models have been generated and validated for use in virtual screening protocols for eight known anticancer drug targets, including tyrosine kinase, protein kinase B β, cyclin-dependent kinase, protein farnesyltransferase, human protein kinase, glycogen synthase kinase, and indoleamine 2,3-dioxygenase 1. Pharmacophore models were validated through receiver operating characteristic and Güner–Henry scoring methods, indicating that several of the models generated could be useful for the identification of potential anticancer agents from natural product databases. The validated pharmacophore models were used as three-dimensional search queries for virtual screening of the newly developed AfroCancer database (~400 compounds from African medicinal plants), along with the Naturally Occurring Plant-based Anticancer Compound-Activity-Target dataset (comprising ~1,500 published naturally occurring plant-based compounds from around the world). Additionally, an in silico assessment of toxicity of the two datasets was carried out by the use of 88 toxicity end points predicted by the Lhasa’s expert knowledge-based system (Derek), showing that only an insignificant proportion of the promising anticancer agents would be likely showing high toxicity profiles. A diversity study of the two datasets, carried out using the analysis of principal components from the most important physicochemical properties often used to access drug-likeness of compound datasets, showed that the two datasets do not occupy the same chemical space. PMID:27445461

  6. Design and evaluation of novel oxadiazole derivatives as potential prostate cancer agents

    PubMed Central

    Qi, Xin; Euynni, Suresh; Sikazwi, Donald; Mateeva, Nelly; Soliman, Karam F.

    2016-01-01

    Various 1,3,4-oxadiazole derivatives have been synthesized and their antiproliferative properties have been studied. The in vitro screening was performed against androgen dependent (LNCaP) and androgen independent (PC-3) prostate cancer cell lines. Most of the compounds showed promising activity. Among them, compounds 2d (IC50 = 0.22 and 1.3 μM) and 2a (IC50 = 8.34 and 2,5 μM) have shown significant activities on PC-3 and LNCaP cell lines respectively. To investigate the mechanism of cell death we performed cell apoptosis staining and cell cycle arrest assay on more sensitive PC-3 cell lines on 2d. The results demonstrated that 2d induced apoptosis and shifted the cells to the sub G0/G1 and S phase. Our study evidently identified the potency of compound 2d as potential anti-prostate cancer agent. PMID:27156770

  7. Novel enterobactin analogues as potential therapeutic chelating agents: Synthesis, thermodynamic and antioxidant studies

    PubMed Central

    Zhang, Qingchun; Jin, Bo; Shi, Zhaotao; Wang, Xiaofang; Liu, Qiangqiang; Lei, Shan; Peng, Rufang

    2016-01-01

    A series of novel hexadentate enterobactin analogues, which contain three catechol chelating moieties attached to different molecular scaffolds with flexible alkyl chain lengths, were prepared. The solution thermodynamic stabilities of the complexes with uranyl, ferric(III), and zinc(II) ions were then investigated. The hexadentate ligands demonstrate effective binding ability to uranyl ion, and the average uranyl affinities are two orders of magnitude higher than 2,3-dihydroxy-N1,N4-bis[(1,2-hydroxypyridinone-6-carboxamide)ethyl]terephthalamide [TMA(2Li-1,2-HOPO)2] ligand with similar denticity. The high affinity of hexadentate ligands could be due to the presence of the flexible scaffold, which favors the geometric agreement between the ligand and the uranyl coordination preference. The hexadentate ligands also exhibit higher antiradical efficiency than butylated hydroxyanisole (BHA). These results provide a basis for further studies on the potential applications of hexadentate ligands as therapeutic chelating agents. PMID:27671769

  8. Sodium arsenite potentiates the clastogenicity and mutagenicity of DNA cross linking agents

    SciTech Connect

    Lee, T.C.; Lee, K.C.; Tzeng, Y.J.; Huang, R.Y.; Jan, K.Y.

    1986-01-01

    To see if sodium arsenite enhances the clastogenicity and the mutagenicity of DNA crosslinking agents, Chinese hamster ovary (CHO) cells and human skin fibroblasts were exposed to cis-diamminedichloroplatinum (II) (cis-Pt(II)) or 8-methoxypsoralen (8-MOP) plus long-wave ultraviolet light (UVA) and then to sodium arsenite. The results indicate that the clastogenicity of cis-Pt(II) and 8-MOP pllus UVA are enhanced by the post-treatment with sodium arsenite. Chromatid breaks and exchanges are predominantly increased in doubly treated cells. Furthermore, the mutagenicity of cis-Pt(II) at the hypoxanthine-guanine phosphoribosyl transferase locus is also potentiated by sodium arsenite in CHO cells

  9. 227Th-EDTMP: a potential therapeutic agent for bone metastasis.

    PubMed

    Washiyama, Kohshin; Amano, Ryohei; Sasaki, Jun; Kinuya, Seigo; Tonami, Norihisa; Shiokawa, Yoshinobu; Mitsugashira, Toshiaki

    2004-10-01

    The biodistribution of 227Th-EDTMP and retention of its daughter nuclide 223Ra were examined. 227Th-EDTMP was found to show high uptake and long-term retention in bone. The clearance of 227Th-EDTMP from blood and soft tissues was rapid and the femur-to-tissue uptake ratios reached more than 100 within 30 min for all tissues except the kidney. Seven and 14 days after injection of 227Th-EDTMP, the retention index of 223Ra in bone showed high values, and the differences between these time points were not significant. Therefore, 227Th-EDTMP is a potential radiotherapeutic agent for bone metastasis. PMID:15464392

  10. Chitosan as a potential stabilizing agent for titania nanoparticle dispersions for preparation of multifunctional cotton fabric.

    PubMed

    Goyal, Nidhi; Rastogi, Deepali; Jassal, Manjeet; Agrawal, Ashwini K

    2016-12-10

    Titania (TiO2) nanoparticle dispersions in water were prepared using chitosan (CS) as the stabilizing agent. The dispersion stability was evaluated with respect to storage time, hydrodynamic particle size, and zeta potential. The effect of the molecular weight of CS and presence of non-ionic polymers (poly(vinyl alcohol) and poly(ethylene glycol)) as co-dispersants was investigated. Despite the increase in size of dispersed particles, the long-term storage stability of the dispersions improved with increasing concentration and molecular weight of CS. The TiO2/CS dispersions were applied on cotton fabric and characterized. The presence of CS did not seriously affect the photocatalytic self-cleaning activity (SCA) of TiO2; with CS, a SCA of 89% was achieved compared with a value of 96% without CS. In addition, the TiO2/CS-treated cotton fabrics provided UV protection and significant antimicrobial activity. PMID:27577907

  11. Potential Use of Phenolic Acids as Anti-Candida Agents: A Review

    PubMed Central

    Teodoro, Guilherme R.; Ellepola, Kassapa; Seneviratne, Chaminda J.; Koga-Ito, Cristiane Y.

    2015-01-01

    There has been a sharp rise in the occurrence of Candida infections and associated mortality over the last few years, due to the growing body of immunocompromised population. Limited number of currently available antifungal agents, undesirable side effects and toxicity, as well as emergence of resistant strains pose a considerable clinical challenge for the treatment of candidiasis. Therefore, molecules that derived from natural sources exhibiting considerable antifungal properties are a promising source for the development of novel anti-candidal therapy. Phenolic compounds isolated from natural sources possess antifungal properties of interest. Particularly, phenolic acids have shown promising in vitro and in vivo activity against Candida species. However, studies on their mechanism of action alone or in synergism with known antifungals are still scarce. This review attempts to discuss the potential use, proposed mechanisms of action and limitations of the phenolic acids in anti-candidal therapy. PMID:26733965

  12. Potential Relevance of Melatonin Against Some Infectious Agents: A Review and Assessment of Recent Research.

    PubMed

    Elmahallawy, Ehab Kotb; Luque, Javier Ortega; Aloweidi, Abdelkarim Saleh; Gutiérrez-Fernández, José; Sampedro-Martínez, Antonio; Rodriguez-Granger, Javier; Kaki, Abdullah; Agil, Ahmad

    2015-01-01

    Melatonin, a tryptophan-derived neurohormone found in animals, plants, and microbes, participates in various biological and physiological functions. Among other properties, numerous in vitro or in vivo studies have reported its therapeutic potential against many parasites, bacteria and viruses. In this concern, melatonin was found to be effective against many parasites such as Plasmodium, Toxoplasma gondii, and Trypansoma cruzi, via various mechanisms such as modulation of calcium level and/or host immune system. Likewise, a recent investigation has reported in vitro activity of melatonin against Leishmania infantum promastigotes which is the causative agent of fascinating visceral Leishmaniasis. This review was initially undertaken to summarize some facts about certain physiological and therapeutic effects of melatonin. It also reviews the effects and action mechanisms of melatonin in bacterial and viral infection besides biology of different parasites which may provide a promising strategy for control of many diseases of public health importance.

  13. Preparation and in vitro evaluation of benzylsulfanyl benzoxazole derivatives as potential antituberculosis agents.

    PubMed

    Klimesová, Vera; Kocí, Jan; Waisser, Karel; Kaustová, Jarmila; Möllmann, Ute

    2009-05-01

    A set of 2-benzylsulfanyl derivatives of benzoxazole was synthesized and evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis, non-tuberculous mycobacteria and multidrug-resistant M. tuberculosis. The activities were expressed as the minimum inhibitory concentration (MIC) in mmol/L. The substances showed similar activity against all tested strains. The lead compounds in the set, dinitro derivatives exhibited significant activity against both sensitive and resistant strains of M. tuberculosis and also against non-tuberculous mycobacteria. To facilitate drug design of benzoxazole as potential antituberculosis agent, we have explored the quantitative structure-activity relationship (QSAR). We demonstrated that lower lipophilicity has significant contribution to activity. Dinitrobenzylsulfanyl derivative of benzoxazole represents the promising small-molecule synthetic antimycobacterials.

  14. Microtubule Stabilizing Agents as Potential Treatment for Alzheimer’s Disease and Related Neurodegenerative Tauopathies

    PubMed Central

    Ballatore, Carlo; Brunden, Kurt R.; Huryn, Donna M.; Trojanowski, John Q.; Lee, Virginia M.-Y.; Smith, Amos B.

    2012-01-01

    The microtubule (MT)-associated protein tau, which is highly expressed in the axons of neurons, is an endogenous MT-stabilizing agent that plays an important role in the axonal transport. Loss of MT-stabilizing tau function, caused by misfolding, hyperphosphorylation and sequestration of tau into insoluble aggregates, leads to axonal transport deficits with neuropathological consequences. Several in vitro and preclinical in vivo studies have shown that MT-stabilizing drugs can be utilized to compensate for the loss of tau function and to maintain/restore an effective axonal transport. These findings indicate that MT-stabilizing compounds hold considerable promise for the treatment of Alzheimer disease and related tauopathies. The present article provides a synopsis of the key findings demonstrating the therapeutic potential of MT-stabilizing drugs in the context of neurodegenerative tauopathies, as well as an overview of the different classes of MT-stabilizing compounds. PMID:23020671

  15. New multifunctional ligands for potential use in the design therapeutic or diagnostic radiopharmaceutical imaging agents

    DOEpatents

    Katti, Kattesh V.; Volkert, Wynn A.; Ketring, Alan R.; Singh, Prahlad R.

    1997-01-01

    A class of diagnostic and therapeutic compounds derived from phosphinimines that include ligands containing either a single phosphinimine functionality or both a phosphinimine group and a phosphine or arsine group, or an aminato group, or a second phosphinimine moiety. These phosphinimine ligands are complexed to early transition metal radionuclides (e.g. .sup.99m Tc or .sup.186 Re/.sup.188 Re) or late transition metals (e.g., .sup.105 Rh or .sup.109 Pd). The complexes with these metals .sup.186 Re/.sup.188 Re, .sup.99m Tc and .sup.109 Pd exhibit a high in vitro and high in vivo stability. The complexes are formed in high yields and can be neutral or charged. These ligands can also be used to form stable compounds with paramagnetic transition metals (e.g. Fe and Mn) for potential use as MRI contrast agents. Applications for the use of ligands and making the ligands are also disclosed.

  16. Novel enterobactin analogues as potential therapeutic chelating agents: Synthesis, thermodynamic and antioxidant studies

    NASA Astrophysics Data System (ADS)

    Zhang, Qingchun; Jin, Bo; Shi, Zhaotao; Wang, Xiaofang; Liu, Qiangqiang; Lei, Shan; Peng, Rufang

    2016-09-01

    A series of novel hexadentate enterobactin analogues, which contain three catechol chelating moieties attached to different molecular scaffolds with flexible alkyl chain lengths, were prepared. The solution thermodynamic stabilities of the complexes with uranyl, ferric(III), and zinc(II) ions were then investigated. The hexadentate ligands demonstrate effective binding ability to uranyl ion, and the average uranyl affinities are two orders of magnitude higher than 2,3-dihydroxy-N1,N4-bis[(1,2-hydroxypyridinone-6-carboxamide)ethyl]terephthalamide [TMA(2Li-1,2-HOPO)2] ligand with similar denticity. The high affinity of hexadentate ligands could be due to the presence of the flexible scaffold, which favors the geometric agreement between the ligand and the uranyl coordination preference. The hexadentate ligands also exhibit higher antiradical efficiency than butylated hydroxyanisole (BHA). These results provide a basis for further studies on the potential applications of hexadentate ligands as therapeutic chelating agents.

  17. Squalamine as a broad-spectrum systemic antiviral agent with therapeutic potential

    PubMed Central

    Zasloff, Michael; Adams, A. Paige; Beckerman, Bernard; Campbell, Ann; Han, Ziying; Luijten, Erik; Meza, Isaura; Julander, Justin; Mishra, Abhijit; Qu, Wei; Taylor, John M.; Weaver, Scott C.; Wong, Gerard C. L.

    2011-01-01

    Antiviral compounds that increase the resistance of host tissues represent an attractive class of therapeutic. Here, we show that squalamine, a compound previously isolated from the tissues of the dogfish shark (Squalus acanthias) and the sea lamprey (Petromyzon marinus), exhibits broad-spectrum antiviral activity against human pathogens, which were studied in vitro as well as in vivo. Both RNA- and DNA-enveloped viruses are shown to be susceptible. The proposed mechanism involves the capacity of squalamine, a cationic amphipathic sterol, to neutralize the negative electrostatic surface charge of intracellular membranes in a way that renders the cell less effective in supporting viral replication. Because squalamine can be readily synthesized and has a known safety profile in man, we believe its potential as a broad-spectrum human antiviral agent should be explored. PMID:21930925

  18. Squalamine as a broad-spectrum systemic antiviral agent with therapeutic potential.

    PubMed

    Zasloff, Michael; Adams, A Paige; Beckerman, Bernard; Campbell, Ann; Han, Ziying; Luijten, Erik; Meza, Isaura; Julander, Justin; Mishra, Abhijit; Qu, Wei; Taylor, John M; Weaver, Scott C; Wong, Gerard C L

    2011-09-20

    Antiviral compounds that increase the resistance of host tissues represent an attractive class of therapeutic. Here, we show that squalamine, a compound previously isolated from the tissues of the dogfish shark (Squalus acanthias) and the sea lamprey (Petromyzon marinus), exhibits broad-spectrum antiviral activity against human pathogens, which were studied in vitro as well as in vivo. Both RNA- and DNA-enveloped viruses are shown to be susceptible. The proposed mechanism involves the capacity of squalamine, a cationic amphipathic sterol, to neutralize the negative electrostatic surface charge of intracellular membranes in a way that renders the cell less effective in supporting viral replication. Because squalamine can be readily synthesized and has a known safety profile in man, we believe its potential as a broad-spectrum human antiviral agent should be explored. PMID:21930925

  19. A potential therapeutic strategy for inhibition of corneal neovascularization with new anti-VEGF agents.

    PubMed

    Hosseini, Hamid; Nejabat, Mahmood

    2007-01-01

    The factors triggering corneal neovascularization involve various growth factors. The data supporting a causal role for vascular endothelial growth factor (VEGF) in corneal neovascularization are extensive. One possible strategy for treating corneal neovascularization is to inhibit VEGF activity by competitively binding VEGF with a specific neutralizing anti-VEGF antibody. The vireo-retinal service in the recent years enjoyed a high level of success in managing choroidal neovascularization using anti-VEGF strategies. Efficacy and tolerability have been demonstrated for drugs targeting VEGF. We herein hypothesize that topical application of new anti-VEGF agents such as pegaptanib, ranibizumab and bevacizumab are potentially useful for inhibiting corneal neovascularization and restoration of corneal clarity. Further investigations are needed to place these medical treatments alongside corneal neovascularization therapeutics. PMID:17107753

  20. Yeasts associated with nectarines and their potential for biological control of brown rot.

    PubMed

    Janisiewicz, W J; Kurtzman, C P; Buyer, J S

    2010-07-01

    Resident fruit microflora has been the source of biocontrol agents for the control of postharvest decay of fruits and the active ingredient in commercialized biocontrol products. With the exception of grapes and apples, information on the resident microflora of other fruits is only fragmentary, but greater knowledge in this area can be very helpful in developing biocontrol strategies. We characterized the yeast microflora of nectarines ('Croce del Sud') from the early stages of fruit development until harvest. The fruit samples were collected from trees in an unmanaged orchard. The resident fruit microflora was separated from the occasionally deposited microorganisms by discarding initial fruit washings before the final wash, followed by sonication and plating on NYDA medium. The isolated yeasts were identified by BIOLOG and by sequencing the D1/D2 domain of a large subunit of the rRNA gene and, where available, the ITS sequence. BIOLOG identified 19 and the genetic analysis 23 species of yeasts. Although the identification by these two systems was not always the same, the predominant yeasts were Rhodotorula spp., Sporodiobolus spp., Cryptococcus spp., Pichia spp., Candida spp. and yeast-like Aureobasidium pullulans. Several of the taxa appear to represent new species. The preliminary biocontrol tests against brown rot of nectarine fruit caused by Monilinia fructicola indicates significant decay control potential of some of the identified yeast species, namely Cryptococcus magnus, Cryptococcus sp. nov., Sporidiobolus pararoseus, A. pullulans and Rhodotorula sp. nov.

  1. Evaluation of Gd-DTPA-monophytanyl and phytantriol nanoassemblies as potential MRI contrast agents.

    PubMed

    Gupta, Abhishek; de Campo, Liliana; Rehmanjan, Beenish; Willis, Scott A; Waddington, Lynne J; Stait-Gardner, Tim; Kirby, Nigel; Price, William S; Moghaddam, Minoo J

    2015-02-01

    Supramolecular self-assembling amphiphiles have been widely used in drug delivery and diagnostic imaging. In this report, we present the self-assembly of Gd (III) chelated DTPA-monophytanyl (Gd-DTPA-MP) amphiphiles incorporated within phytantriol (PT), an inverse bicontinuous cubic phase forming matrix at various compositions. The dispersed colloidal nanoassemblies were evaluated as potential MRI contrast agents at various magnetic field strengths. The homogeneous incorporation of Gd-DTPA-MP in PT was confirmed by polarized optical microscopy (POM) and synchrotron small-angle X-ray scattering (SAXS) of the bulk phases of the mixtures. The liquid crystalline nanostructures, morphology, and the size distribution of the nanoassemblies were studied by SAXS, cryogenic transmission electron microscopy (cryo-TEM), and dynamic light scattering (DLS). The dispersions with up to 2 mol % of Gd-DTPA-MP in PT retained inverse cubosomal nanoassemblies, whereas the rest of the dispersions transformed to liposomal nanoassemblies. In vitro relaxivity studies were performed on all the dispersions at 0.54, 9.40, and 11.74 T and compared to Magnevist, a commercially available contrast agent. All the dispersions showed much higher relaxivities compared to Magnevist at both low and high magnetic field strengths. Image contrast of the nanoassemblies was also found to be much better than Magnevist at the same Gd concentration at 11.74 T. Moreover, the Gd-DTPA-MP/PT dispersions showed improved relaxivities over the pure Gd-DTPA-MP dispersion at high magnetic fields. These stable colloidal nanoassemblies have high potential to be used as combined delivery matrices for diagnostics and therapeutics.

  2. Novel Penicillin Analogues as Potential Antimicrobial Agents; Design, Synthesis and Docking Studies.

    PubMed

    Ashraf, Zaman; Bais, Abdul; Manir, Md Maniruzzaman; Niazi, Umar

    2015-01-01

    A number of penicillin derivatives (4a-h) were synthesized by the condensation of 6-amino penicillinic acid (6-APA) with non-steroidal anti-inflammatory drugs as antimicrobial agents. In silico docking study of these analogues was performed against Penicillin Binding Protein (PDBID 1CEF) using AutoDock Tools 1.5.6 in order to investigate the antimicrobial data on structural basis. Penicillin binding proteins function as either transpeptidases or carboxypeptidases and in few cases demonstrate transglycosylase activity in bacteria. The excellent antibacterial potential was depicted by compounds 4c and 4e against Escherichia coli, Staphylococcus epidermidus and Staphylococcus aureus compared to the standard amoxicillin. The most potent penicillin derivative 4e exhibited same activity as standard amoxicillin against S. aureus. In the enzyme inhibitory assay the compound 4e inhibited E. coli MurC with an IC50 value of 12.5 μM. The docking scores of these compounds 4c and 4e also verified their greater antibacterial potential. The results verified the importance of side chain functionalities along with the presence of central penam nucleus. The binding affinities calculated from docking results expressed in the form of binding energies ranges from -7.8 to -9.2kcal/mol. The carboxylic group of penam nucleus in all these compounds is responsible for strong binding with receptor protein with the bond length ranges from 3.4 to 4.4 Ǻ. The results of present work ratify that derivatives 4c and 4e may serve as a structural template for the design and development of potent antimicrobial agents.

  3. Novel Penicillin Analogues as Potential Antimicrobial Agents; Design, Synthesis and Docking Studies

    PubMed Central

    Ashraf, Zaman; Bais, Abdul; Manir, Md. Maniruzzaman; Niazi, Umar

    2015-01-01

    A number of penicillin derivatives (4a-h) were synthesized by the condensation of 6-amino penicillinic acid (6-APA) with non-steroidal anti-inflammatory drugs as antimicrobial agents. In silico docking study of these analogues was performed against Penicillin Binding Protein (PDBID 1CEF) using AutoDock Tools 1.5.6 in order to investigate the antimicrobial data on structural basis. Penicillin binding proteins function as either transpeptidases or carboxypeptidases and in few cases demonstrate transglycosylase activity in bacteria. The excellent antibacterial potential was depicted by compounds 4c and 4e against Escherichia coli, Staphylococcus epidermidus and Staphylococcus aureus compared to the standard amoxicillin. The most potent penicillin derivative 4e exhibited same activity as standard amoxicillin against S. aureus. In the enzyme inhibitory assay the compound 4e inhibited E. coli MurC with an IC50 value of 12.5 μM. The docking scores of these compounds 4c and 4e also verified their greater antibacterial potential. The results verified the importance of side chain functionalities along with the presence of central penam nucleus. The binding affinities calculated from docking results expressed in the form of binding energies ranges from -7.8 to -9.2kcal/mol. The carboxylic group of penam nucleus in all these compounds is responsible for strong binding with receptor protein with the bond length ranges from 3.4 to 4.4 Ǻ. The results of present work ratify that derivatives 4c and 4e may serve as a structural template for the design and development of potent antimicrobial agents. PMID:26267242

  4. A quantitative structure activity/dose response relationship for contact allergic potential of alkyl group transfer agents.

    PubMed

    Roberts, D W; Basketter, D A

    1990-11-01

    As part of the investigation of structure activity relationships in contact allergy, it has been shown that methyl transfer agents are capable of acting as skin sensitizers. This work has now been extended to a more general examination of alkyl transfer reactions. The modified single injection adjuvant test has been used to investigate the sensitization potential of C12, C16 and unsaturated C18 alkyl transfer agents. Dose responses to challenge and the patterns of cross-reactivity between these materials and methyl transfer agents have been studied. All alkyl transfer agents examined were potent sensitizers in the guinea pig. There was evidence of mutual cross-reactivity between all alkyl transfer agents examined (including methyl transfer agents). Analysis of the data in terms of a modified relative alkylation index showed evidence of an overload effect. The sensitization data has been accurately modelled using a mathematical equation. These results emphasize the possibilities for relating physicochemical parameters and skin sensitization potential. Further studies with alkyl transfer agents are in progress of amplify the observations and conclusions presented in this report. No in vitro model is available for the prediction of skin sensitization potential. Therefore an approach based on a model using physicochemical criteria is the most likely route to a reduced requirement for animal testing. PMID:1965716

  5. Demographic Modelling in Weed Biocontrol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Demographic matrix modeling of plant populations can be a powerful tool to identify key life stage transitions that contribute the most to population growth of an invasive plant and hence should be targeted for disruption. Therefore, this approach has the potential to guide the pre-release selection...

  6. Biocontrol of Aspergillus Species on Peanut Kernels by Antifungal Diketopiperazine Producing Bacillus cereus Associated with Entomopathogenic Nematode

    PubMed Central

    Kumar, Sasidharan Nishanth; Sreekala, Sreerag Ravikumar; Chandrasekaran, Dileep; Nambisan, Bala; Anto, Ruby John

    2014-01-01

    The rhabditid entomopathogenic nematode associated Bacillus cereus and the antifungal compounds produced by this bacterium were evaluated for their activity in reducing postharvest decay of peanut kernels caused by Aspergillus species in in vitro and in vivo tests. The results showed that B. cereus had a significant effect on biocontrol effectiveness in in vitro and in vivo conditions. The antifungal compounds produced by the B. cereus were purified using silica gel column chromatography and their structure was elucidated using extensive spectral analyses. The compounds were identified as diketopiperazines (DKPs) [cyclo-(L-Pro-Gly), cyclo(L-Tyr-L-Tyr), cyclo-(L-Phe-Gly) and cyclo(4-hydroxy-L-Pro-L-Trp)]. The antifungal activities of diketopiperazines were studied against five Aspergillus species and best MIC of 2 µg/ml was recorded against A. flavus by cyclo(4-hydroxy-L-Pro-L-Trp). To investigate the potential application of cyclo(4-hydroxy-L-Pro-L-Trp) to eliminate fungal spoilage in food and feed, peanut kernels was used as a food model system. White mycelia and dark/pale green spores of Aspergillus species were observed in the control peanut kernels after 2 days incubation. However the fungal growth was not observed in peanut kernels treated with cyclo(4-hydroxy-L-Pro-L-Trp). The cyclo(4-hydroxy-L-Pro-L-Trp) was nontoxic to two normal cell lines [fore skin (FS) normal fibroblast and African green monkey kidney (VERO)] up to 200 µg/ml in MTT assay. Thus the cyclo(4-hydroxy-L-Pro-L-Trp) identified in this study may be a promising alternative to chemical preservatives as a potential biopreservative agent which prevent fungal growth in food and feed. To the best of our knowledge, this is the first report demonstrating that the entomopathogenic nematode associated B. cereus and cyclo(4-hydroxy-L-Pro-L-Trp) could be used as a biocontrol agents against postharvest fungal disease caused by Aspergillus species. PMID:25157831

  7. The S-adenosyl-L-homocysteine hydrolase gene ahcY of Agrobacterium radiobacter K84 is required for optimal growth, antibiotic production, and biocontrol of crown gall disease.

    PubMed

    Penyalver, Ramón; Oger, Phil M; Su, Shengchang; Alvarez, Belén; Salcedo, Carmina I; López, María M; Farrand, Stephen K

    2009-06-01

    Agrobacterium radiobacter K84 is a commercial agent used worldwide to control crown gall disease caused by pathogenic isolates of A. tumefaciens. More than 2,000 transposon insertion derivatives of strain K84 were screened by a standardized greenhouse bioassay to identify mutants defective in biocontrol. Three mutants affected in biocontrol properties were identified. All three mutants displayed normal levels of attachment to tomato seed and root colonization. One of these mutants, M19-164, exhibited partial biocontrol and did not produce detectable levels of agrocin 84. In this mutant, the transposon is located in the agn locus of pAgK84, which codes for agrocin 84 biosynthesis. The second mutant, M19-158, also exhibited partial biocontrol and produced reduced amounts of agrocin 84 as a result of a mutation in a chromosomal gene of unknown function. The third mutant, M9-22, failed to biocontrol, was impaired in both growth in minimal medium and siderophore production, and failed to produce detectable levels of agrocin 84. The chromosomal gene ahcY, which encodes S-adenosyl-l-homocysteine hydrolase, was disrupted in this mutant. Expression of a functional copy of ahcY in M9-22 restored all of the altered phenotypes. The fact that all identified biocontrol mutants exhibited a partial or total defect in production of agrocin 84 indicates that this antibiotic is required for optimum biocontrol. This study also identified two chromosomally encoded genes required for agrocin 84 production. That a mutation in ahcY abolishes biocontrol suggests that the intracellular ratio of S-adenosyl-l-methionine to S-adenosyl-l-homocysteine is an important factor for agrocin 84 biosynthesis. Finally, we demonstrate that the ahcY gene in strain K84 is also required for optimal growth as well as for antibiotic production and biocontrol of crown gall disease.

  8. Siderophore as a potential plant growth-promoting agent produced by Pseudomonas aeruginosa JAS-25.

    PubMed

    Sulochana, M B; Jayachandra, S Y; Kumar, S Anil; Parameshwar, A B; Reddy, K Mohan; Dayanand, A

    2014-09-01

    Siderophores scavenges Fe(+3) from the vicinity of the roots of plants, and thus limit the amount of iron required for the growth of pathogens such as Fusarium oxysporum, Pythium ultimum, and Fusarium udum, which cause wilt and root rot disease in crops. The ability of Pseudomonas to grow and to produce siderophore depends upon the iron content, pH, and temperature. Maximum yield of siderophore of 130 μM was observed at pH 7.0 ± 0.2 and temperature of 30 °C at 30 h. The threshold level of iron was 50 μM, which increases up to 150 μM, favoring growth but drastically affecting the production of siderophore by Pseudomonas aeruginosa JAS-25. The seeds of agricultural crops like Cicer arietinum (chick pea), Cajanus cajan (pigeon pea), and Arachis hypogaea (ground nut) were treated with P. aeruginosa JAS-25, which enhanced the seed germination, root length, shoot length, and dry weight of chick pea, pigeon pea, and ground nut plants under pot studies. The efficient growth of the plants was not only due to the biocontrol activity of the siderophore produced by P. aeruginosa JAS-25 but also may be by the production of indole acetic acid (IAA), which influences the growth of the plants as phytohormones. PMID:25062779

  9. Siderophore as a potential plant growth-promoting agent produced by Pseudomonas aeruginosa JAS-25.

    PubMed

    Sulochana, M B; Jayachandra, S Y; Kumar, S Anil; Parameshwar, A B; Reddy, K Mohan; Dayanand, A

    2014-09-01

    Siderophores scavenges Fe(+3) from the vicinity of the roots of plants, and thus limit the amount of iron required for the growth of pathogens such as Fusarium oxysporum, Pythium ultimum, and Fusarium udum, which cause wilt and root rot disease in crops. The ability of Pseudomonas to grow and to produce siderophore depends upon the iron content, pH, and temperature. Maximum yield of siderophore of 130 μM was observed at pH 7.0 ± 0.2 and temperature of 30 °C at 30 h. The threshold level of iron was 50 μM, which increases up to 150 μM, favoring growth but drastically affecting the production of siderophore by Pseudomonas aeruginosa JAS-25. The seeds of agricultural crops like Cicer arietinum (chick pea), Cajanus cajan (pigeon pea), and Arachis hypogaea (ground nut) were treated with P. aeruginosa JAS-25, which enhanced the seed germination, root length, shoot length, and dry weight of chick pea, pigeon pea, and ground nut plants under pot studies. The efficient growth of the plants was not only due to the biocontrol activity of the siderophore produced by P. aeruginosa JAS-25 but also may be by the production of indole acetic acid (IAA), which influences the growth of the plants as phytohormones.

  10. [Evaluation of Trichoderma spp. as antagonist of Rhizoctonia solani in vitro and as biocontrol of greenhouse tomato plants].

    PubMed

    Durman, S; Menendez, A; Godeas, A

    1999-01-01

    Five Trichoderma isolates were compared in their ability for controlling Rhizoctonia solani attack to tomato plants in greenhouse and as antagonists of this pathogen in three independent laboratory assays. Four out of five isolates showed biocontrol ability and decreased pathogen growth and survival of its sclerotia in soil. Results suggest that dual cultures in Petri dishes and mycoparasitism assays against R. solani sclerotia may be useful for detecting isolates effective as biological control agents against this pathogen in tomato plants. PMID:10327455

  11. Epidermal growth factor (EGF) as a potential targeting agent for delivery of boron to malignant gliomas

    SciTech Connect

    Capala, J.; Barth, R.F.; Adams, D.M.; Bailey, M.Q.; Soloway, A.H.; Carlsson, J.

    1994-12-31

    The majority of high grade gliomas express an amplified epidermal growth factor receptor (EGFR) gene, and this often is associated with an increase in cell surface receptor expression. The rapid internalization and degradation of EGF-EGFR complexes, as well as their high affinity make EGF a potential targeting agent for delivery of {sup 10}B to tumor cells with an amplified number of EGFR. Human glioma cells can expresses as many as 10{sup 5} {minus}10{sup 6} EGF receptors per cell, and if these could be saturated with boronated EGF, then > 10{sup 8} boron atoms would be delivered per cell. Since EGF has a comparatively low molecular weight ({approximately} 6 kD), this has allowed us to construct relatively small bioconjugates containing {approximately} 900 boron atoms per EGF molecule{sup 3}, which also had high affinity for EGFR on tumor cells. In the present study, the feasibility of using EGF receptors as a potential target for therapy of gliomas was investigated by in vivo scintigraphic studies using {sup 131}I{minus} or {sup 99m}{Tc}-labeled EGF in a rat brain tumor model. Our results indicate that intratumorally delivered boron- EGF conjugates might be useful for targeting EGFR on glioma cells if the boron containing moiety of the conjugates persisted intracellularly. Further studies are required, however, to determine if this approach can be used for BNCT of the rat glioma.

  12. STATINS MORE THAN CHOLESTEROL LOWERING AGENTS IN ALZHEIMER DISEASE: THEIR PLEIOTROPIC FUNCTIONS AS POTENTIAL THERAPEUTIC TARGETS

    PubMed Central

    Barone, Eugenio; Domenico, Fabio Di; Butterfield, D. Allan

    2013-01-01

    Alzheimer disease (AD) is a progressive neurodegenerative disorder characterized by severe cognitive impairment, inability to perform activities of daily living and mood changes. Statins, long known to be beneficial in conditions where dyslipidemia occurs by lowering serum cholesterol levels, also have been proposed for use in neurodegenerative conditions, including AD. However, it is not clear that the purported effectiveness of statins in neurodegenerative disorders is directly related to cholesterol-lowering effects of these agents; rather, the pleiotropic functions of statins likely play critical roles. The aim of this review is to provide an overview on the new discoveries about the effects of statin therapy on the oxidative ad nitrosative stress levels as well as on the modulation of the heme oxygenase/biliverdin reductase (HO/BVR) system in the brain. We propose a novel mechanism of action for atorvastatin which, through the activation of HO/BVR-A system, may contribute to the neuroprotective effects thus suggesting a potential therapeutic role in AD and potentially accounting for the observation of decreased AD incidence with persons on statin. PMID:24231510

  13. Screening for potential anti-infective agents towards Burkholderia pseudomallei infection

    NASA Astrophysics Data System (ADS)

    Eng, Su Anne; Nathan, Sheila

    2014-09-01

    The established treatment for melioidosis is antibiotic therapy. However, a constant threat to this form of treatment is resistance development of the causative agent, Burkholderia pseudomallei, towards antibiotics. One option to circumvent this threat of antibiotic resistance is to search for new alternative anti-infectives which target the host innate immune system and/or bacterial virulence. In this study, 29 synthetic compounds were evaluated for their potential to increase the lifespan of an infected host. The nematode Caenorhabditis elegans was adopted as the infection model as its innate immune pathways are homologous to humans. Screens were performed in a liquid-based survival assay containing infected worms exposed to individual compounds and survival of untreated and compound-treated worms were compared. A primary screen identified nine synthetic compounds that extended the lifespan of B. pseudomallei-infected worms. Subsequently, a disc diffusion test was performed on these selected compounds to delineate compounds into those that enhanced the survival of worms via antimicrobial activity i.e. reducing the number of infecting bacteria, or into those that did not target pathogen viability. Out of the nine hits selected, two demonstrated antimicrobial effects on B. pseudomallei. Therefore, the findings from this study suggest that the other seven identified compounds are potential anti-infectives which could protect a host against B. pseudomallei infection without developing the risk of drug resistance.

  14. An information potential approach for tracking and surveilling multiple moving targets using mobile sensor agents

    NASA Astrophysics Data System (ADS)

    Lu, W.; Zhang, G.; Ferrari, S.; Fierro, R.; Palunko, I.

    2011-05-01

    The problem of surveilling moving targets using mobile sensor agents (MSAs) is applicable to a variety of fields, including environmental monitoring, security, and manufacturing. Several authors have shown that the performance of a mobile sensor can be greatly improved by planning its motion and control strategies based on its sensing objectives. This paper presents an information potential approach for computing the MSAs' motion plans and control inputs based on the feedback from a modified particle filter used for tracking moving targets. The modified particle filter, as presented in this paper implements a new sampling method (based on supporting intervals of density functions), which accounts for the latest sensor measurements and adapts, accordingly, a mixture representation of the probability density functions (PDFs) for the target motion. It is assumed that the target motion can be modeled as a semi-Markov jump process, and that the PDFs of the Markov parameters can be updated based on real-time sensor measurements by a centralized processing unit or MSAs supervisor. Subsequently, the MSAs supervisor computes an information potential function that is communicated to the sensors, and used to determine their individual feedback control inputs, such that sensors with bounded field-of-view (FOV) can follow and surveil the target over time.

  15. Triterpenoids as potential agents for the chemoprevention and therapy of breast cancer

    PubMed Central

    Bishayee, Anupam; Ahmed, Shamima; Brankov, Nikoleta; Perloff, Marjorie

    2010-01-01

    Breast cancer remains a major cause of death in the United States as well as the rest of the world. In view of the limited treatment options for patients with advanced breast cancer, preventive and novel therapeutic approaches play an important role in combating this disease. The plant-derived triterpenoids, commonly used for medicinal purposes in many Asian countries, posses various pharmacological properties. A large number of triterpenoids are known to exhibit cytotoxicity against a variety of tumor cells as well as anticancer efficacy in preclinical animal models. Numerous triterpenoids have been synthesized by structural modification of natural compounds. Some of these analogs are considered to be the most potent antiinflammatory and anticarcinogenic triterpenoids known. This review examines the potential role of natural triterpenoids and their derivatives in the chemoprevention and treatment of mammary tumors. Both in vitro and in vivo effects of these agents and related molecular mechanisms are presented. Potential challenges and future directions involved in the advancement of these promising compounds in the prevention and therapy of human breast cancer are also identified. PMID:21196213

  16. Ketamine potentiates cerebrocortical damage induced by the common anaesthetic agent nitrous oxide in adult rats.

    PubMed

    Jevtovic-Todorovic, V; Benshoff, N; Olney, J W

    2000-08-01

    For general anaesthesia, patients usually receive a combination of drugs, all of which are classified as gamma-amino-butyric acid (GABA) agonists, with two notable exceptions - ketamine and nitrous oxide (laughing gas, N(2)O) - which are antagonists of N-methyl-D-aspartate (NMDA) glutamate receptors. At clinically relevant doses both ketamine and N(2)O, like other NMDA antagonists, have the potential to induce psychotomimetic reactions in humans and to cause pathomorphological changes in cerebrocortical neurons in rat brain. Because drug combinations used in clinical anaesthesia sometimes include both ketamine and N(2)O, we undertook experiments to evaluate whether augmented neurotoxicity results from their combined use. Ketamine and N(2)O were administered alone or in combination by various dosing regimens to adult female rats for a duration of 3 h and the severity of cerebrocortical neurotoxic changes was quantified histologically. Because GABA agonists are known to protect against the psychotomimetic and neurotoxic effects of NMDA antagonists, we also evaluated whether the combined neurotoxicity of ketamine+N(2)O can be prevented by certain commonly used GABA agonists. When ketamine and N(2)O were used in combination the neurotoxic reaction was enhanced to a degree much greater than can be explained by simple additivity. The apparent synergistic interaction was particularly striking when low doses of the agents were combined, the degree of toxic synergism at higher doses being masked by a ceiling effect. GABA agonists protected against ketamine/N(2)O neurotoxicity. It is recommended that this information be taken into consideration in the selection of drugs to be used in multi-agent protocols for general anaesthesia. PMID:10928976

  17. Combining UV-C treatment with biocontrol yeast to control postharvest decay of melon.

    PubMed

    Huang, Ke; Zou, Yong; Luo, Jie; Liu, Yiqing

    2015-09-01

    Significant losses in harvested melon can be directly attributable to decay fungi. In the present study, the use of UV-C treatment combined with biocontrol yeast, Pichia cecembensis, was evaluated for their ability to control postharvest decay of melon fruits after they were artificially inoculated with Fusarium oxysporum and Alternaria alternata. Natural infection of fruit was also assessed. As a stand-alone treatment, UV-C or P. cecembensis significantly reduced Fusarium rot and Alternaria rot, and also the level of natural infection on melon fruit, relative to the untreated control. The combination of UV-C or P. cecembensis, however, provided a superior level of decay control on artificially inoculated and naturally infected fruit, compared to either treatment alone. None of the treatments impaired fruit quality. Integrating the use of UV-C treatment with biocontrol yeast has potential as an effective method to control postharvest decay of melon.

  18. Synthesis and evaluation of 18F labeled alanine derivatives as potential tumor imaging agents

    PubMed Central

    Wang, Limin; Zha, Zhihao; Qu, Wenchao; Qiao, Hongwen; Lieberman, Brian P.; Plössl, Karl; Kung, Hank F.

    2012-01-01

    Introduction This paper reports the synthesis and labeling of 18F alanine derivatives. We also investigate their biological characteristics as potential tumor imaging agents mediated by alanine-serine-cysteine preferring (ASC) transporter system. Methods Three new 18F alanine derivatives were prepared from corresponding tosylate-precursors through a two-step labelling reaction. In vitro uptake studies to evaluate and to compare these three analogs were carried out in 9L glioma and PC-3 prostate cancer cell lines. Potential transport mechanisms, protein incorporation and stability of 3-(1-[18F]fluoromethyl)-L-alanine (L[18F]FMA) were investigated in 9L glioma cells. Its biodistribution was determined in a rat-bearing 9L tumor model. PET imaging studies were performed on rat bearing 9L glioma tumors and transgenic mouse carrying spontaneous generated M/tomND tumor (mammary gland adenocarcinoma). Results New 18F alanine derivatives were prepared with 7–34% uncorrected radiochemical yields, excellent enantiomeric purity (>99%) and good radiochemical purity (>99%). In vitro uptake of the L-[18F]FMA in 9L glioma and PC-3 prostate cancer cells was higher than those observed for other two alanine derivatives and [18F]FDG in first 1 h. Inhibition of cell uptake studies suggested that L-[18F]FMA uptake in 9L glioma was predominantly via transport system ASC. After entering into cells, L-[18F]FMA remained stable and was not incorporated into protein within 2 h. In vivo biodistribution studies demonstrated that L-[18F]FMA had relatively high uptake in liver and kidney. Tumor uptake was fast, reaching a maximum within 30 min. The tumor-to-muscle, tumor-to-blood and tumor-to-brain ratios at 60 min post injection were 2.2, 1.9 and 3.0, respectively. In PET imaging studies, tumors were visualized with L-[18F]FMA in both 9L rat and transgenic mouse. Conclusion L-[18F]FMA showed promising properties as a PET imaging agent for up-regulated ASC transporter associated with tumor

  19. Polyol synthesis, functionalisation, and biocompatibility studies of superparamagnetic iron oxide nanoparticles as potential MRI contrast agents

    NASA Astrophysics Data System (ADS)

    Hachani, Roxanne; Lowdell, Mark; Birchall, Martin; Hervault, Aziliz; Mertz, Damien; Begin-Colin, Sylvie; Thanh, Nguy&Ecirtil; N. Thi&Cmb. B. Dot; Kim

    2016-02-01

    Iron oxide nanoparticles (IONPs) of low polydispersity were obtained through a simple polyol synthesis in high pressure and high temperature conditions. The control of the size and morphology of the nanoparticles was studied by varying the solvent used, the amount of iron precursor and the reaction time. Compared with conventional synthesis methods such as thermal decomposition or co-precipitation, this process yields nanoparticles with a narrow particle size distribution in a simple, reproducible and cost effective manner without the need for an inert atmosphere. For example, IONPs with a diameter of ca. 8 nm could be made in a reproducible manner and with good crystallinity as evidenced by X-ray diffraction analysis and high saturation magnetization value (84.5 emu g-1). The surface of the IONPs could be tailored post synthesis with two different ligands which provided functionality and stability in water and phosphate buffer saline (PBS). Their potential as a magnetic resonance imaging (MRI) contrast agent was confirmed as they exhibited high r1 and r2 relaxivities of 7.95 mM-1 s-1 and 185.58 mM-1 s-1 respectively at 1.4 T. Biocompatibility and viability of IONPs in primary human mesenchymal stem cells (hMSCs) was studied and confirmed.Iron oxide nanoparticles (IONPs) of low polydispersity were obtained through a simple polyol synthesis in high pressure and high temperature conditions. The control of the size and morphology of the nanoparticles was studied by varying the solvent used, the amount of iron precursor and the reaction time. Compared with conventional synthesis methods such as thermal decomposition or co-precipitation, this process yields nanoparticles with a narrow particle size distribution in a simple, reproducible and cost effective manner without the need for an inert atmosphere. For example, IONPs with a diameter of ca. 8 nm could be made in a reproducible manner and with good crystallinity as evidenced by X-ray diffraction analysis and high

  20. Experimental evidence for the phenotypic impact of admixture between wild and biocontrol Asian ladybird (Harmonia axyridis) involved in the European invasion.

    PubMed

    Turgeon, J; Tayeh, A; Facon, B; Lombaert, E; De Clercq, P; Berkvens, N; Lundgren, J G; Estoup, A

    2011-05-01

    Hybridization can fuel evolutionary processes during biological invasions. The harlequin ladybird Harmonia axyridis has long been used as a biocontrol agent before the species became invasive worldwide. Previous analysis based on microsatellite data has shown that European invasive populations bear traces of admixture between an eastern North American source, which is at the origin of the worldwide invasion, and biocontrol strains used in Europe. In this study, we tested the hypothesis that this early admixture event may have fostered the European invasion by impacting on the phenotypes of wild European populations. Mean life history traits of experimental F(1) hybrids are compared with pure parental sources and wild European crosses. Our results reveal a biased impact whereby North American beetles benefitted from being admixed with European biocontrol strains. Resemblance between experimental hybrids and wild European invasive crosses further suggests a long-lasting effect of admixture that may still be at work and fostering invasiveness.

  1. Draft Genome Sequence of the Endophytic Strain Rhodococcus kyotonensis KB10, a Potential Biodegrading and Antibacterial Bacterium Isolated from Arabidopsis thaliana

    PubMed Central

    Hong, Chi Eun; Jo, Sung Hee

    2016-01-01

    Rhodococcus kyotonensis KB10 is an endophytic bacterium isolated from Arabidopsis thaliana. The organism showed mild antibacterial activity against the phytopathogen Pseudomonas syringae pv. tomato DC3000. This study reports the genome sequence of R. kyotonensis KB10. This bacterium contains an ectoine biosynthesis gene cluster and has the potential to degrade nitroaromatic compounds. The identified bacterium may be a suitable biocontrol agent and degrader of environmental pollutants. PMID:27389269

  2. Striga Biocontrol on a Toothpick: A Readily Deployable and Inexpensive Method for Smallholder Farmers.

    PubMed

    Nzioki, Henry S; Oyosi, Florence; Morris, Cindy E; Kaya, Eylul; Pilgeram, Alice L; Baker, Claire S; Sands, David C

    2016-01-01

    Striga hermonthica (witchweed) is a parasitic weed that attacks and significantly reduces the yields of maize, sorghum, millet, and sugarcane throughout sub-Saharan Africa. Low cost management methods such as hand weeding, short crop rotations, trap cropping, or conventional biocontrol have not been effective. Likewise, Striga-tolerant or herbicide-resistant maize cultivars are higher yielding, but are often beyond the economic means of sustenance farmers. The fungal pathogen, Fusarium oxysporum f.sp. strigae, has been the object of numerous studies to develop Striga biocontrol. Under experimental conditions this pathogen can reduce the incidence of Striga infestation but field use is not extensive, perhaps because it has not been sufficiently effective in restoring crop yield and reducing the soil Striga seed bank. Here we brought together Kenyan and US crop scientists with smallholder farmers to develop and validate an effective biocontrol strategy for management of Striga on smallholder farms. Key components of this research project were the following: (1) Development of a two-step method of fungal delivery, including laboratory coating of primary inoculum on toothpicks, followed by on-farm production of secondary field inoculum in boiled rice enabling delivery of vigorous, fresh inoculum directly to the seedbed; (2) Training of smallholder farmers (85% women), to produce the biocontrol agent and incorporate it into their maize plantings in Striga-infested soils and collect agronomic data. The field tests expanded from 30 smallholder farmers to a two-season, 500-farmer plot trial including paired plus and minus biocontrol plots with fertilizer and hybrid seed in both plots and; (3) Concerted selection of variants of the pathogen identified for enhanced virulence, as has been demonstrated in other host parasite systems were employed here on Striga via pathogen excretion of the amino acids L-leucine and L-tyrosine that are toxic to Striga but innocuous to maize

  3. Striga Biocontrol on a Toothpick: A Readily Deployable and Inexpensive Method for Smallholder Farmers

    PubMed Central

    Nzioki, Henry S.; Oyosi, Florence; Morris, Cindy E.; Kaya, Eylul; Pilgeram, Alice L.; Baker, Claire S.; Sands, David C.

    2016-01-01

    Striga hermonthica (witchweed) is a parasitic weed that attacks and significantly reduces the yields of maize, sorghum, millet, and sugarcane throughout sub-Saharan Africa. Low cost management methods such as hand weeding, short crop rotations, trap cropping, or conventional biocontrol have not been effective. Likewise, Striga-tolerant or herbicide-resistant maize cultivars are higher yielding, but are often beyond the economic means of sustenance farmers. The fungal pathogen, Fusarium oxysporum f.sp. strigae, has been the object of numerous studies to develop Striga biocontrol. Under experimental conditions this pathogen can reduce the incidence of Striga infestation but field use is not extensive, perhaps because it has not been sufficiently effective in restoring crop yield and reducing the soil Striga seed bank. Here we brought together Kenyan and US crop scientists with smallholder farmers to develop and validate an effective biocontrol strategy for management of Striga on smallholder farms. Key components of this research project were the following: (1) Development of a two-step method of fungal delivery, including laboratory coating of primary inoculum on toothpicks, followed by on-farm production of secondary field inoculum in boiled rice enabling delivery of vigorous, fresh inoculum directly to the seedbed; (2) Training of smallholder farmers (85% women), to produce the biocontrol agent and incorporate it into their maize plantings in Striga-infested soils and collect agronomic data. The field tests expanded from 30 smallholder farmers to a two-season, 500-farmer plot trial including paired plus and minus biocontrol plots with fertilizer and hybrid seed in both plots and; (3) Concerted selection of variants of the pathogen identified for enhanced virulence, as has been demonstrated in other host parasite systems were employed here on Striga via pathogen excretion of the amino acids L-leucine and L-tyrosine that are toxic to Striga but innocuous to maize

  4. Molecular Modeling Studies of Thiophenyl C-Aryl Glucoside SGLT2 Inhibitors as Potential Antidiabetic Agents

    PubMed Central

    Sharma, Mukesh C.; Sharma, Smita

    2014-01-01

    A QSAR study on thiophenyl derivatives as SGLT2 inhibitors as potential antidiabetic agents was performed with thirty-three compounds. Comparison of the obtained results indicated the superiority of the genetic algorithm over the simulated annealing and stepwise forward-backward variable method for feature selection. The best 2D QSAR model showed satisfactory statistical parameters for the data set (r2 = 0.8499, q2 = 0.8267, and pred_r2 = 0.7729) with four descriptors describing the nature of substituent groups and the environment of the substitution site. Evaluation of the model implied that electron-rich substitution position improves the inhibitory activity. The good predictive 3D-QSAR models by k-nearest neighbor (kNN) method for molecular field analysis (MFA) have cross-validated coefficient q2 value of 0.7663 and predicted r2 value of 0.7386. The results have showed that thiophenyl groups are necessary for activity and halogen, bulky, and less bulky groups in thiophenyl nucleus enhanced the biological activity. These studies are promising for the development of novel SGLT2 inhibitor, which may have potent antidiabetic activity. PMID:25574393

  5. Evaluation of Se-75 BISTAES as a potential articular cartilage imaging agent

    SciTech Connect

    Yu, S.W.K.

    1987-01-01

    The potential of Se-75 bis (..beta..-N,N,N-trimethylamino)-ethyl) selenide diiodide (Se-75 BISTAES) as an articular cartilage imaging agent for the early diagnosis of osteoarthritis was evaluated. The compound was synthesized and the identity was established. The radiochemical purity and stability were determined initially and over a two-month period of storage at three temperatures. The biodistribution of Se-75 BISTAES in rabbits and guinea pigs was studied. A high concentration of radioactivity was found in the knee and shoulder cartilage. The radioactivity in the cartilage was the highest at 15 minutes to one hour post-injection. In rabbits, the highest ratio of radioactivity in the cartilage to the surrounding tissues was about 30. A minimal ratio of 10 is required for nuclear medicine imaging. Nuclear medicine imaging conducted on rabbits demonstrated increased radioactivity in the articular cartilage in the knee and shoulder. The impression from the nuclear medicine images and the findings of the biodistribution study indicated that the route of excretion of Se-75 BISTAES was the urine. The in vitro binding between Se-75 BISTAES and chondroitin sulfate was determined by an equilibrium dialysis technique.

  6. Human recombinant truncated RNASET2, devoid of RNase activity; A potential cancer therapeutic agent

    PubMed Central

    Nesiel-Nuttman, Liron; Schwartz, Betty; Shoseyov, Oded

    2014-01-01

    Human RNASET2 has been implicated in antitumorigenic and antiangiogenic activities, independent of its ribonuclease capacities. We constructed a truncated version of human RNASET2, starting at E50 (trT2-50) and devoid of ribonuclease activity. trT2-50 maintained its ability to bind actin and to inhibit angiogenesis and tumorigenesis. trT2-50 binds to cell surface actin and formed a complex with actin in vitro. The antiangiogenic effect of this protein was demonstrated in human umbilical vein endothelial cells (HUVECs) by its ability to arrest tube formation on Matrigel, induced by angiogenic factors. Immunofluorescence staining of HUVECs showed nuclear and cytosolic RNASET2 protein that was no longer detectable inside the cell following trT2-50 treatment. This effect was associated with disruption of the intracellular actin network. trT2-50 co-localized with angiogenin, suggesting that both molecules bind (or compete) for similar cellular epitopes. Moreover, trT2-50 led to a significant inhibition of tumor development. Histological analysis demonstrated abundant necrotic tissue and a substantial loss of endothelial structure in trT2-50-treated tumors. Collectively, the present results indicate that trT2-50, a molecule engineered to be deficient of its catalytic activity, still maintained its actin binding and anticancer-related biological activities. We therefore suggest that trT2-50 may serve as a potential cancer therapeutic agent. PMID:25426551

  7. Scaffold Hopping Toward Agomelatine: Novel 3, 4-Dihydroisoquinoline Compounds as Potential Antidepressant Agents

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Ang, Wei; Long, Haiyue; Chang, Ying; Li, Zicheng; Zhou, Liangxue; Yang, Tao; Deng, Yong; Luo, Youfu

    2016-10-01

    A scaffold-hopping strategy toward Agomelatine based on in silico screening and knowledge analysis was employed to design novel antidepressant agents. A series of 3, 4-dihydroisoquinoline compounds were selected for chemical synthesis and biological assessment. Three compounds (6a-1, 6a-2, 6a-9) demonstrated protective effects on corticosterone-induced lesion of PC12 cells. Compound 6a-1 also displayed low inhibitory effects on the growth of HEK293 and L02 normal cells and it was further evaluated for its potential antidepressant effects in vivo. The forced swim test (FST) results revealed that compound 6a-1 remarkably reduced the immobility time of rats and the open field test (OFT) results indicated a better general locomotor activity of the rats treated with compound 6a-1 than those with Agomelatine or Fluoxetine. Mechanism studies implied that compound 6a-1 can significantly reduce PC12 cell apoptosis by up-regulation of GSH and down-regulation of ROS in corticosterone-induced lesion of PC12 cells. Meanwhile, the down-regulation of calcium ion concentration and up-regulation of BDNF level in PC12 cells may account for the neuroprotective effects. Furthermore, compound 6a-1 can increase cell survival and cell proliferation, promote cell maturation in the rat hippocampus after chronic treatment. The acute toxicity data in vivo indicated compound 6a-1 exhibited less hepatotoxicity than Agomelatine.

  8. Biorelevant reactions of the potential anti-tumor agent vanadocene dichloride.

    PubMed

    Sanna, Daniele; Serra, Maria; Ugone, Valeria; Manca, Laura; Pirastru, Monica; Buglyó, Péter; Bíró, Linda; Micera, Giovanni; Garribba, Eugenio

    2016-05-01

    The interaction of the potential anti-tumor agent vanadocene dichloride ([Cp2VCl2] or VDC) with some relevant bioligands of the cytosol such as proteins (Hb), amino acids (glycine and histidine), NADH derivatives (NADH, NADPH, NAD(+) and NADP(+)), reductants (GSH and ascorbic acid), phosphates (HPO4(2-), P2O7(4-), cAMP, AMP, ADP and ATP) and carboxylate derivatives (lactate) and its uptake by red blood cells were studied. The results indicated that [Cp2VCl2] transforms at physiological pH into [Cp2V(OH)2] and that only HPO4(2-), P2O7(4-), lactate, ATP and ADP form mixed species with the [Cp2V](2+) moiety replacing the two hydroxide ions. EPR and electronic absorption spectroscopy, agarose gel electrophoresis and spin trapping measurements allow excluding any direct interaction and/or intercalation with DNA and the formation of reactive oxygen species (ROS) in Fenton-like reactions. Uptake experiments by erythrocytes suggested that VDC crosses the membrane and enters inside the cells, whereas 'bare' V(IV) transforms into V(IV)O species with loss of the two cyclopentadienyl rings. This transformation in the cellular environment could be related to the mechanism of action of VDC. PMID:27121101

  9. Recent Development of Multifunctional Agents as Potential Drug Candidates for the Treatment of Alzheimer's Disease

    PubMed Central

    Guzior, Natalia; ckowska,, Anna Wię; Panek, Dawid; Malawska, Barbara

    2015-01-01

    Alzheimer’s disease (AD) is a complex and progressive neurodegenerative disorder. The available therapy is limited to the symptomatic treatment and its efficacy remains unsatisfactory. In view of the prevalence and expected increase in the incidence of AD, the development of an effective therapy is crucial for public health. Due to the multifactorial aetiology of this disease, the multi-target-directed ligand (MTDL) approach is a promising method in search for new drugs for AD. This review updates information on the development of multifunctional potential anti-AD agents published within the last three years. The majority of the recently reported structures are acetylcholinesterase inhibitors, often endowed with some additional properties. These properties enrich the pharmacological profile of the compounds giving hope for not only symptomatic but also causal treatment of the disease. Among these advantageous properties, the most often reported are an amyloid-β anti-aggregation activity, inhibition of β-secretase and monoamine oxidase, an antioxidant and metal chelating activity, NO-releasing ability and interaction with cannabinoid, NMDA or histamine H3 receptors. The majority of novel molecules possess heterodimeric structures, able to interact with multiple targets by combining different pharmacophores, original or derived from natural products or existing therapeutics (tacrine, donepezil, galantamine, memantine). Among the described compounds, several seem to be promising drug candidates, while others may serve as a valuable inspiration in the search for new effective therapies for AD. PMID:25386820

  10. The preclinical pharmacokinetic disposition of a series of perforin-inhibitors as potential immunosuppressive agents.

    PubMed

    Bull, M R; Spicer, J A; Huttunen, K M; Denny, W A; Ciccone, A; Browne, K A; Trapani, J A; Helsby, N A

    2015-12-01

    The cytolytic protein perforin is a key component of the immune response and is implicated in a number of human pathologies and therapy-induced conditions. A novel series of small molecule inhibitors of perforin function have been developed as potential immunosuppressive agents. The pharmacokinetics and metabolic stability of a series of 16 inhibitors of perforin was evaluated in male CD1 mice following intravenous administration. The compounds were well tolerated 6 h after dosing. After intravenous administration at 5 mg/kg, maximum plasma concentrations ranged from 532 ± 200 to 10,061 ± 12 ng/mL across the series. Plasma concentrations were greater than the concentrations required for in vitro inhibitory activity for 11 of the compounds. Following an initial rapid distribution phase, the elimination half-life values for the series ranged from 0.82 ± 0.25 to 4.38 ± 4.48 h. All compounds in the series were susceptible to oxidative biotransformation. Following incubations with microsomal preparations, a tenfold range in in vitro half-life was observed across the series. The data suggests that oxidative biotransformation was not singularly responsible for clearance of the compounds and no direct relationship between microsomal clearance and plasma clearance was observed. Structural modifications however, do provide some information as to the relative microsomal stability of the compounds, which may be useful for further drug development.

  11. Potential of Submergedly Cultivated Mycelia of Ganoderma spp. as Antioxidant and Antimicrobial Agents.

    PubMed

    Ćilerdžić, Jasmina; Stajic, Mirjana; Vukojevic, Jelena

    2016-01-01

    The study aimed to evaluate the antiradical and antimicrobial (antibacterial and antifungal) potentials of ethanol mycelial extracts of selected Ganoderma species and strains and to define interand intraspecies diversity among Ganoderma species and strains. Ganoderma lucidum strains were good DPPH• scavengers (neutralizing up to 57.12% radicals), contrary to G. applanatum (20.35%) and G. carnosum (17.04%). High correlations between the activities and contents of total phenols in the extracts showed that these compounds were carriers of the activity. Results obtained by both discdiffusion and microdilution methods indicated that the extract of G. lucidum BEOFB 433 was the most potent antibacterial agent that inhibited growth of almost all bacterial species at a concentration of 1.0 mg/mL. Salmonella typhimurium was the most sensitive species to the mycelium extracts. Extracts of G. lucidum BEOFB 431 and BEOFB 434 showed the best antifungal activity since in concentration of 0.5 mg/mL inhibited the growth of Aspergillus glaucus (BEOFB 431) and the growth of A. glaucus and Trichoderma viride (BEOFB 434). Extracts of G. applanatum and G. lucidum BEOFB 431 had the strongest fungicidal effects, with lethal outcomes for A. glaucus and T. viride, respectively, being noted at a concentration of 1.17 mg/mL. Aspergillus niger was proved as the most resistant species. PMID:26420047

  12. Potential of immunomodulatory agents as adjunct host-directed therapies for multidrug-resistant tuberculosis.

    PubMed

    Zumla, Alimuddin; Rao, Martin; Dodoo, Ernest; Maeurer, Markus

    2016-06-15

    Treatment of multidrug-resistant tuberculosis (MDR-TB) is extremely challenging due to the virulence of the etiologic strains of Mycobacterium tuberculosis (M. tb), the aberrant host immune responses and the diminishing treatment options with TB drugs. New treatment regimens incorporating therapeutics targeting both M. tb and host factors are urgently needed to improve the clinical management outcomes of MDR-TB. Host-directed therapies (HDT) could avert destructive tuberculous lung pathology, facilitate eradication of M. tb, improve survival and prevent long-term functional disability. In this review we (1) discuss the use of HDT for cancer and other infections, drawing parallels and the precedent they set for MDR-TB treatment, (2) highlight preclinical studies of pharmacological agents commonly used in clinical practice which have HDT potential, and (3) outline developments in cellular therapy to promote clinically beneficial immunomodulation to improve treatment outcomes in patients with pulmonary MDR-TB. The use of HDTs as adjuncts to MDR-TB therapy requires urgent evaluation.

  13. Sonorensin: A new bacteriocin with potential of an anti-biofilm agent and a food biopreservative.

    PubMed

    Chopra, Lipsy; Singh, Gurdeep; Kumar Jena, Kautilya; Sahoo, Debendra K

    2015-01-01

    The emergence of antibiotic resistant bacteria has led to exploration of alternative therapeutic agents such as ribosomally synthesized bacterial peptides known as bacteriocins. Biofilms, which are microbial communities that cause serious chronic infections, form environments that enhance antimicrobial resistance. Bacteria in biofilm can be upto thousand times more resistant to antibiotics than the same bacteria circulating in a planktonic state. In this study, sonorensin, predicted to belong to the heterocycloanthracin subfamily of bacteriocins, was found to be effectively killing active and non-multiplying cells of both Gram-positive and Gram-negative bacteria. Sonorensin showed marked inhibition activity against biofilm of Staphylococcus aureus. Fluorescence and electron microscopy suggested that growth inhibition occurred because of increased membrane permeability. Low density polyethylene film coated with sonorensin was found to effectively control the growth of food spoilage bacteria like Listeria monocytogenes and S. aureus. The biopreservative effect of sonorensin coated film showing growth inhibition of spoilage bacteria in chicken meat and tomato samples demonstrated the potential of sonorensin as an alternative to current antibiotics/ preservatives. PMID:26292786

  14. Potential of immunomodulatory agents as adjunct host-directed therapies for multidrug-resistant tuberculosis.

    PubMed

    Zumla, Alimuddin; Rao, Martin; Dodoo, Ernest; Maeurer, Markus

    2016-01-01

    Treatment of multidrug-resistant tuberculosis (MDR-TB) is extremely challenging due to the virulence of the etiologic strains of Mycobacterium tuberculosis (M. tb), the aberrant host immune responses and the diminishing treatment options with TB drugs. New treatment regimens incorporating therapeutics targeting both M. tb and host factors are urgently needed to improve the clinical management outcomes of MDR-TB. Host-directed therapies (HDT) could avert destructive tuberculous lung pathology, facilitate eradication of M. tb, improve survival and prevent long-term functional disability. In this review we (1) discuss the use of HDT for cancer and other infections, drawing parallels and the precedent they set for MDR-TB treatment, (2) highlight preclinical studies of pharmacological agents commonly used in clinical practice which have HDT potential, and (3) outline developments in cellular therapy to promote clinically beneficial immunomodulation to improve treatment outcomes in patients with pulmonary MDR-TB. The use of HDTs as adjuncts to MDR-TB therapy requires urgent evaluation. PMID:27301245

  15. Rapid screening of potential autophagic inductor agents using mammalian cell lines.

    PubMed

    Martins, Waleska K; Severino, Divinomar; Souza, Cleidiane; Stolf, Beatriz S; Baptista, Maurício S

    2013-06-01

    Recent progress in understanding the molecular basis of autophagy has demonstrated its importance in several areas of human health. Affordable screening techniques with higher sensitivity and specificity to identify autophagy are, however, needed to move the field forward. In fact, only laborious and/or expensive methodologies such as electron microscopy, dye-staining of autophagic vesicles, and LC3-II immunoblotting or immunoassaying are available for autophagy identification. Aiming to fulfill this technical gap, we describe here the association of three widely used assays to determine cell viability - Crystal Violet staining (CVS), 3-[4, 5-dimethylthiaolyl]-2, 5-diphenyl-tetrazolium bromide (MTT) reduction, and neutral red uptake (NRU) - to predict autophagic cell death in vitro. The conceptual framework of the method is the superior uptake of NR in cells engaging in autophagy. NRU was then weighted by the average of MTT reduction and CVS allowing the calculation of autophagic arbitrary units (AAU), a numeric variable that correlated specifically with the autophagic cell death. The proposed strategy is very useful for drug discovery, allowing the investigation of potential autophagic inductor agents through a rapid screening using mammalian cell lines B16-F10, HaCaT, HeLa, MES-SA, and MES-SA/Dx5 in a unique single microplate.

  16. Child as change agent. The potential of children to increase healthy food purchasing.

    PubMed

    Wingert, Katherine; Zachary, Drew A; Fox, Monica; Gittelsohn, Joel; Surkan, Pamela J

    2014-10-01

    Shoppers make many food choices while buying groceries. Children frequently accompany caregivers, giving them the potential to influence these choices. We aimed to understand low-income shoppers' perceptions of how children influence caregivers' purchasing decisions and how the supermarket environment could be manipulated to allow children to serve as change agents for healthy food purchasing in a primarily African-American community. We conducted thirty in-depth interviews, five follow-up interviews, one supermarket walk-through interview, and four focus groups with adult supermarket shoppers who were regular caregivers for children under age 16. We conducted one focus group with supermarket employees and one in-depth interview with a supermarket manager. Qualitative data were analyzed using iterative thematic coding and memo writing. Caregivers approached grocery shopping with efforts to save money, prevent waste and purchase healthy food for their families, but described children as promoting unplanned, unhealthy food purchases. This influence was exacerbated by the supermarket environment, which participants found to promote unhealthy options and provide limited opportunities for children to interact with healthier foods. Caregivers' suggestions for promoting healthy purchasing for shoppers with children included manipulating the placement of healthy and unhealthy foods and offering opportunities for children to taste and interact with healthy options. PMID:24996593

  17. Potential of Submergedly Cultivated Mycelia of Ganoderma spp. as Antioxidant and Antimicrobial Agents.

    PubMed

    Ćilerdžić, Jasmina; Stajic, Mirjana; Vukojevic, Jelena

    2016-01-01

    The study aimed to evaluate the antiradical and antimicrobial (antibacterial and antifungal) potentials of ethanol mycelial extracts of selected Ganoderma species and strains and to define interand intraspecies diversity among Ganoderma species and strains. Ganoderma lucidum strains were good DPPH• scavengers (neutralizing up to 57.12% radicals), contrary to G. applanatum (20.35%) and G. carnosum (17.04%). High correlations between the activities and contents of total phenols in the extracts showed that these compounds were carriers of the activity. Results obtained by both discdiffusion and microdilution methods indicated that the extract of G. lucidum BEOFB 433 was the most potent antibacterial agent that inhibited growth of almost all bacterial species at a concentration of 1.0 mg/mL. Salmonella typhimurium was the most sensitive species to the mycelium extracts. Extracts of G. lucidum BEOFB 431 and BEOFB 434 showed the best antifungal activity since in concentration of 0.5 mg/mL inhibited the growth of Aspergillus glaucus (BEOFB 431) and the growth of A. glaucus and Trichoderma viride (BEOFB 434). Extracts of G. applanatum and G. lucidum BEOFB 431 had the strongest fungicidal effects, with lethal outcomes for A. glaucus and T. viride, respectively, being noted at a concentration of 1.17 mg/mL. Aspergillus niger was proved as the most resistant species.

  18. N-( sup 18 F)fluoroacetyl-D-glucosamine: A potential agent for cancer diagnosis

    SciTech Connect

    Fujiwara, T.; Kubota, K.; Sato, T.; Matsuzawa, T.; Tada, M.; Iwata, R.; Itoh, M.; Hatazawa, J.; Sato, K.; Fukuda, H. )

    1990-10-01

    Positron labeled substrates such as sugars, amino acids, and nucleosides have been investigated for the in-vivo evaluation of biochemical processes in cancerous tissue. Hexosamines are obligatory structural components of many biologically important macromolecules, including membrane glycoproteins and mucopolysaccharide. We evaluated a new synthesized pharmaceutical, N-({sup 18}F)fluoroacetyl-D-glucosamine ({sup 18}F-FAG), which is a structural analog of N-acetyl-D-glucosamine. C3H/HeMsNRS mice bearing spontaneous hepatomas were used for the tissue distribution study. At 60 min after injection, high uptakes were found in tumor (5.16, mean value of %dose/g), liver (3.71), and kidney (3.27). The tumor uptake of 18F-FAG showed the highest value in all tissue. In the PET study, VX-2 carcinoma of the rabbit was clearly visualized. Our preliminary results suggest that {sup 18}F-FAG has potential as a new agent for tumor imaging.

  19. Scaffold Hopping Toward Agomelatine: Novel 3, 4-Dihydroisoquinoline Compounds as Potential Antidepressant Agents

    PubMed Central

    Yang, Yang; Ang, Wei; Long, Haiyue; Chang, Ying; Li, Zicheng; Zhou, Liangxue; Yang, Tao; Deng, Yong; Luo, Youfu

    2016-01-01

    A scaffold-hopping strategy toward Agomelatine based on in silico screening and knowledge analysis was employed to design novel antidepressant agents. A series of 3, 4-dihydroisoquinoline compounds were selected for chemical synthesis and biological assessment. Three compounds (6a-1, 6a-2, 6a-9) demonstrated protective effects on corticosterone-induced lesion of PC12 cells. Compound 6a-1 also displayed low inhibitory effects on the growth of HEK293 and L02 normal cells and it was further evaluated for its potential antidepressant effects in vivo. The forced swim test (FST) results revealed that compound 6a-1 remarkably reduced the immobility time of rats and the open field test (OFT) results indicated a better general locomotor activity of the rats treated with compound 6a-1 than those with Agomelatine or Fluoxetine. Mechanism studies implied that compound 6a-1 can significantly reduce PC12 cell apoptosis by up-regulation of GSH and down-regulation of ROS in corticosterone-induced lesion of PC12 cells. Meanwhile, the down-regulation of calcium ion concentration and up-regulation of BDNF level in PC12 cells may account for the neuroprotective effects. Furthermore, compound 6a-1 can increase cell survival and cell proliferation, promote cell maturation in the rat hippocampus after chronic treatment. The acute toxicity data in vivo indicated compound 6a-1 exhibited less hepatotoxicity than Agomelatine. PMID:27698414

  20. Animals living in polluted environments are potential source of antimicrobials against infectious agents

    PubMed Central

    Lee, Simon; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2012-01-01

    The antimicrobials crisis is a ticking time bomb which could lead to millions of people dying from untreatable infections. With the worsening trends of antimicrobial resistance, we are heading towards a pre-antibiotic era. Thus, there is a need for newer and more powerful antibiotic agents. The search for new antibiotic compounds originating from natural resources is a promising research area. Animals living in germ-infested environments are a potent source of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of bacteria, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances which show potent activity in the nervous system. We hope that the discovery of antimicrobial activity in the cockroach brain will stimulate research in finding antimicrobials from unusual sources, and has potential for the development of novel antibiotics. Nevertheless, intensive research in the next few years will be required to approach or realize these expectations. PMID:23265422

  1. Recent development of multifunctional agents as potential drug candidates for the treatment of Alzheimer's disease.

    PubMed

    Guzior, Natalia; Wieckowska, Anna; Panek, Dawid; Malawska, Barbara

    2015-01-01

    Alzheimer's disease (AD) is a complex and progressive neurodegenerative disorder. The available therapy is limited to the symptomatic treatment and its efficacy remains unsatisfactory. In view of the prevalence and expected increase in the incidence of AD, the development of an effective therapy is crucial for public health. Due to the multifactorial aetiology of this disease, the multi-target-directed ligand (MTDL) approach is a promising method in search for new drugs for AD. This review updates information on the development of multifunctional potential anti-AD agents published within the last three years. The majority of the recently reported structures are acetylcholinesterase inhibitors, often endowed with some additional properties. These properties enrich the pharmacological profile of the compounds giving hope for not only symptomatic but also causal treatment of the disease. Among these advantageous properties, the most often reported are an amyloid-β antiaggregation activity, inhibition of β-secretase and monoamine oxidase, an antioxidant and metal chelating activity, NOreleasing ability and interaction with cannabinoid, NMDA or histamine H3 receptors. The majority of novel molecules possess heterodimeric structures, able to interact with multiple targets by combining different pharmacophores, original or derived from natural products or existing therapeutics (tacrine, donepezil, galantamine, memantine). Among the described compounds, several seem to be promising drug candidates, while others may serve as a valuable inspiration in the search for new effective therapies for AD. PMID:25386820

  2. Sonorensin: A new bacteriocin with potential of an anti-biofilm agent and a food biopreservative

    PubMed Central

    Chopra, Lipsy; Singh, Gurdeep; Kumar Jena, Kautilya; Sahoo, Debendra K.

    2015-01-01

    The emergence of antibiotic resistant bacteria has led to exploration of alternative therapeutic agents such as ribosomally synthesized bacterial peptides known as bacteriocins. Biofilms, which are microbial communities that cause serious chronic infections, form environments that enhance antimicrobial resistance. Bacteria in biofilm can be upto thousand times more resistant to antibiotics than the same bacteria circulating in a planktonic state. In this study, sonorensin, predicted to belong to the heterocycloanthracin subfamily of bacteriocins, was found to be effectively killing active and non-multiplying cells of both Gram-positive and Gram-negative bacteria. Sonorensin showed marked inhibition activity against biofilm of Staphylococcus aureus. Fluorescence and electron microscopy suggested that growth inhibition occurred because of increased membrane permeability. Low density polyethylene film coated with sonorensin was found to effectively control the growth of food spoilage bacteria like Listeria monocytogenes and S. aureus. The biopreservative effect of sonorensin coated film showing growth inhibition of spoilage bacteria in chicken meat and tomato samples demonstrated the potential of sonorensin as an alternative to current antibiotics/ preservatives. PMID:26292786

  3. New multifunctional ligands for potential use in the design therapeutic or diagnostic radiopharmaceutical imaging agents

    DOEpatents

    Katti, K.V.; Volkert, W.A.; Ketring, A.R.; Singh, P.R.

    1997-02-11

    A class of diagnostic and therapeutic compounds are derived from phosphinimines that include ligands containing either a single phosphinimine functionality or both a phosphinimine group and a phosphine or arsine group, or an aminato group, or a second phosphinimine moiety. These phosphinimine ligands are complexed to early transition metal radionuclides (e.g., {sup 99m}Tc or {sup 186}Re/{sup 188}Re) or late transition metals (e.g., {sup 105}Rh or {sup 109}Pd). The complexes with these metals {sup 186}Re/{sup 188}Re, {sup 99m}Tc and {sup 109}Pd exhibit a high in vitro and high in vivo stability. The complexes are formed in high yields and can be neutral or charged. These ligands can also be used to form stable compounds with paramagnetic transition metals (e.g., Fe and Mn) for potential use as MRI contrast agents. Applications for the use of ligands and making the ligands are also disclosed.

  4. Sonorensin: A new bacteriocin with potential of an anti-biofilm agent and a food biopreservative.

    PubMed

    Chopra, Lipsy; Singh, Gurdeep; Kumar Jena, Kautilya; Sahoo, Debendra K

    2015-01-01

    The emergence of antibiotic resistant bacteria has led to exploration of alternative therapeutic agents such as ribosomally synthesized bacterial peptides known as bacteriocins. Biofilms, which are microbial communities that cause serious chronic infections, form environments that enhance antimicrobial resistance. Bacteria in biofilm can be upto thousand times more resistant to antibiotics than the same bacteria circulating in a planktonic state. In this study, sonorensin, predicted to belong to the heterocycloanthracin subfamily of bacteriocins, was found to be effectively killing active and non-multiplying cells of both Gram-positive and Gram-negative bacteria. Sonorensin showed marked inhibition activity against biofilm of Staphylococcus aureus. Fluorescence and electron microscopy suggested that growth inhibition occurred because of increased membrane permeability. Low density polyethylene film coated with sonorensin was found to effectively control the growth of food spoilage bacteria like Listeria monocytogenes and S. aureus. The biopreservative effect of sonorensin coated film showing growth inhibition of spoilage bacteria in chicken meat and tomato samples demonstrated the potential of sonorensin as an alternative to current antibiotics/ preservatives.

  5. Curcumin derivatives as metal-chelating agents with potential multifunctional activity for pharmaceutical applications.

    PubMed

    Ferrari, Erika; Benassi, Rois; Sacchi, Stefania; Pignedoli, Francesca; Asti, Mattia; Saladini, Monica

    2014-10-01

    Curcuminoids represent new perspectives for the development of novel therapeutics for Alzheimer's disease (AD), one probable mechanism of action is related to their metal complexing ability. In this work we examined the metal complexing ability of substituted curcuminoids to propose new chelating molecules with biological properties comparable with curcumin but with improved stability as new potential AD therapeutic agents. The K2T derivatives originate from the insertion of a -CH2COOC(CH3)3 group on the central atom of the diketonic moiety of curcumin. They retain the diketo-ketoenol tautomerism which is solvent dependent. In aqueous solution the prevalent form is the diketo one but the addition of metal ion (Ga(3+), Cu(2+)) causes the dissociation of the enolic proton creating chelate complexes and shifting the tautomeric equilibrium towards the keto-enol form. The formation of metal complexes is followed by both NMR and UV-vis spectroscopy. The density functional theory (DFT) calculations on K2T21 complexes with Ga(3+) and Cu(2+) are performed and compared with those on curcumin complexes. [Ga(K2T21)2(H2O)2](+) was found more stable than curcumin one. Good agreement is detected between calculated and experimental (1)H and (13)C NMR data. The calculated OH bond dissociation energy (BDE) and the OH proton dissociation enthalpy (PDE), allowed to predict the radical scavenging ability of the metal ion complexed with K2T21, while the calculated electronic affinity (EA) and ionization potential (IP) represent yardsticks of antioxidant properties. Eventually theoretical calculations suggest that the proton-transfer-associated superoxide-scavenging activity is enhanced after binding metal ions, and that Ga(3+) complexes display possible superoxide dismutase (SOD)-like activity.

  6. Novel glyoxalase-I inhibitors possessing a “zinc-binding feature” as potential anticancer agents

    PubMed Central

    Al-Balas, Qosay A; Hassan, Mohammad A; Al-Shar’i, Nizar A; Mhaidat, Nizar M; Almaaytah, Ammar M; Al-Mahasneh, Fatima M; Isawi, Israa H

    2016-01-01

    Background The glyoxalase system including two thiol-dependent enzymes, glyoxalase I (Glo-I) and glyoxalase II, plays an important role in a ubiquitous metabolic pathway involved in cellular detoxification of cytotoxic 2-oxoaldehydes. Tumor cells have high glycolytic activity, leading to increased cellular levels of these toxic metabolites. The increased activity of the detoxification system in cancerous cells makes this pathway a viable target for developing novel anticancer agents. In this study, we examined the potential utility of non-glutathione-based inhibitors of the Glo-I enzyme as novel anticancer drugs. Methods Computer-aided drug design techniques, such as customized pharmacophoric features, virtual screening, and flexible docking, were used to achieve the project goals. Retrieved hits were extensively filtered and subsequently docked into the active site of the enzyme. The biological activities of retrieved hits were assessed using an in vitro assay against Glo-I. Results Since Glo-I is a zinc metalloenzyme, a customized Zn-binding pharmacophoric feature was used to search for selective inhibitors via virtual screening of a small-molecule database. Seven hits were selected, purchased, and biologically evaluated. Three of the seven hits inhibited Glo-I activity, the most effective of which exerted 76.4% inhibition at a concentration of 25 µM. Conclusion We successfully identified a potential Glo-I inhibitor that can serve as a lead compound for further optimization. Moreover, our in silico and experimental results were highly correlated. Hence, the docking protocol adopted in this study may be efficiently employed in future optimization steps. PMID:27574401

  7. Volatile Organic Compounds from Native Potato-associated Pseudomonas as Potential Anti-oomycete Agents

    PubMed Central

    De Vrieze, Mout; Pandey, Piyush; Bucheli, Thomas D.; Varadarajan, Adithi R.; Ahrens, Christian H.; Weisskopf, Laure; Bailly, Aurélien

    2015-01-01

    The plant kingdom represents a prominent biodiversity island for microbes that associate with the below- or aboveground organs of vegetal species. Both the root and the leaf represent interfaces where dynamic biological interactions influence plant life. Beside well-studied communication strategies based on soluble compounds and protein effectors, bacteria were recently shown to interact both with host plants and other microbial species through the emissions of volatile organic compounds (VOCs). Focusing on the potato late blight-causing agent Phytophthora infestans, this work addresses the potential role of the bacterial volatilome in suppressing plant diseases. In a previous study, we isolated and identified a large collection of strains with anti-Phytophthora potential from both the phyllosphere and the rhizosphere of potato. Here we report the characterization and quantification of their emissions of biogenic volatiles, comparing 16 Pseudomonas strains differing in (i) origin of isolation (phyllosphere vs. rhizosphere), (ii) in vitro inhibition of P. infestans growth and sporulation behavior, and (iii) protective effects against late blight on potato leaf disks. We systematically tested the pharmacological inhibitory activity of core and strain-specific single compounds against P. infestans mycelial growth and sporangial behavior in order to identify key effective candidate molecules present in the complex natural VOCs blends. We envisage the plant bacterial microbiome as a reservoir for functional VOCs and establish the basis for finding the primary enzymatic toolset that enables the production of active components of the volatile bouquet in plant-associated bacteria. Comprehension of these functional interspecies interactions will open perspectives for the sustainable control of plant diseases in forthcoming agriculture. PMID:26635763

  8. Biocontrol and Rapid Detection of Food-Borne Pathogens Using Bacteriophages and Endolysins

    PubMed Central

    Bai, Jaewoo; Kim, You-Tae; Ryu, Sangryeol; Lee, Ju-Hoon

    2016-01-01

    Bacteriophages have been suggested as natural food preservatives as well as rapid detection materials for food-borne pathogens in various foods. Since Listeria monocytogenes-targeting phage cocktail (ListShield) was approved for applications in foods, numerous phages have been screened and experimentally characterized for phage applications in foods. A single phage and phage cocktail treatments to various foods contaminated with food-borne pathogens including E. coli O157:H7, Salmonella enterica, Campylobacter jejuni, Listeria monocytogenes, Staphylococcus aureus, Cronobacter sakazakii, and Vibrio spp. revealed that they have great potential to control various food-borne pathogens and may be alternative for conventional food preservatives. In addition, phage-derived endolysins with high host specificity and host lysis activities may be preferred to food applications rather than phages. For rapid detection of food-borne pathogens, cell-wall binding domains (CBDs) from endolysins have been suggested due to their high host-specific binding. Fluorescence-tagged CBDs have been successfully evaluated and suggested to be alternative materials of expensive antibodies for various detection applications. Most recently, reporter phage systems have been developed and tested to confirm their usability and accuracy for specific detection. These systems revealed some advantages like rapid detection of only viable pathogenic cells without interference by food components in a very short reaction time, suggesting that these systems may be suitable for monitoring of pathogens in foods. Consequently, phage is the next-generation biocontrol agent as well as rapid detection tool to confirm and even identify the food-borne pathogens present in various foods. PMID:27092128

  9. Biocontrol and Rapid Detection of Food-Borne Pathogens Using Bacteriophages and Endolysins.

    PubMed

    Bai, Jaewoo; Kim, You-Tae; Ryu, Sangryeol; Lee, Ju-Hoon

    2016-01-01

    Bacteriophages have been suggested as natural food preservatives as well as rapid detection materials for food-borne pathogens in various foods. Since Listeria monocytogenes-targeting phage cocktail (ListShield) was approved for applications in foods, numerous phages have been screened and experimentally characterized for phage applications in foods. A single phage and phage cocktail treatments to various foods contaminated with food-borne pathogens including E. coli O157:H7, Salmonella enterica, Campylobacter jejuni, Listeria monocytogenes, Staphylococcus aureus, Cronobacter sakazakii, and Vibrio spp. revealed that they have great potential to control various food-borne pathogens and may be alternative for conventional food preservatives. In addition, phage-derived endolysins with high host specificity and host lysis activities may be preferred to food applications rather than phages. For rapid detection of food-borne pathogens, cell-wall binding domains (CBDs) from endolysins have been suggested due to their high host-specific binding. Fluorescence-tagged CBDs have been successfully evaluated and suggested to be alternative materials of expensive antibodies for various detection applications. Most recently, reporter phage systems have been developed and tested to confirm their usability and accuracy for specific detection. These systems revealed some advantages like rapid detection of only viable pathogenic cells without interference by food components in a very short reaction time, suggesting that these systems may be suitable for monitoring of pathogens in foods. Consequently, phage is the next-generation biocontrol agent as well as rapid detection tool to confirm and even identify the food-borne pathogens present in various foods.

  10. Biocontrol and Rapid Detection of Food-Borne Pathogens Using Bacteriophages and Endolysins.

    PubMed

    Bai, Jaewoo; Kim, You-Tae; Ryu, Sangryeol; Lee, Ju-Hoon

    2016-01-01

    Bacteriophages have been suggested as natural food preservatives as well as rapid detection materials for food-borne pathogens in various foods. Since Listeria monocytogenes-targeting phage cocktail (ListShield) was approved for applications in foods, numerous phages have been screened and experimentally characterized for phage applications in foods. A single phage and phage cocktail treatments to various foods contaminated with food-borne pathogens including E. coli O157:H7, Salmonella enterica, Campylobacter jejuni, Listeria monocytogenes, Staphylococcus aureus, Cronobacter sakazakii, and Vibrio spp. revealed that they have great potential to control various food-borne pathogens and may be alternative for conventional food preservatives. In addition, phage-derived endolysins with high host specificity and host lysis activities may be preferred to food applications rather than phages. For rapid detection of food-borne pathogens, cell-wall binding domains (CBDs) from endolysins have been suggested due to their high host-specific binding. Fluorescence-tagged CBDs have been successfully evaluated and suggested to be alternative materials of expensive antibodies for various detection applications. Most recently, reporter phage systems have been developed and tested to confirm their usability and accuracy for specific detection. These systems revealed some advantages like rapid detection of only viable pathogenic cells without interference by food components in a very short reaction time, suggesting that these systems may be suitable for monitoring of pathogens in foods. Consequently, phage is the next-generation biocontrol agent as well as rapid detection tool to confirm and even identify the food-borne pathogens present in various foods. PMID:27092128

  11. Antitumor Agents 250.† Design and Synthesis of New Curcumin Analogs as Potential Anti-Prostate Cancer Agents

    PubMed Central

    Lin, Li; Shi, Qian; Nyarko, Alexander K.; Bastow, Kenneth F.; Wu, Chin-Chung; Su, Ching-Yuan; Shih, Charles C.-Y; Lee, Kuo-Hsiung

    2008-01-01

    In a continuing study of curcumin analogs as potential drug candidates to treat prostate cancer at both androgen-dependent and androgen-refractory stages, we designed and synthesized over 40 new analogs classified into four series: monophenyl analogs (series A), heterocycle-containing analogs (series B), analogs bearing various substituents on the phenyl rings (series C) and analogs with various linkers (series D). These new compounds were tested for cytotoxicity against two human prostate cancer cell lines, androgen-dependent LNCaP and androgen-independent PC-3. Antiandrogenic activity was also evaluated in LNCaP cells and PC-3 cells transfected with wild-type androgen receptor. Ten compounds possessed potent cytotoxicity against both LNCaP and PC-3 cells; seven only against LNCaP; and one solely against PC-3. This study established an advanced structure-activity relationship (SAR), and these correlations will guide the further design of new curcumin analogs with better anti-prostate cancer activity. PMID:16789753

  12. Genomic Basis of Plant Pathogen Suppression by Biocontrol Pseudomonas Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Various plant commensal bacterial species, which naturally colonize the plant rhizosphere, are able to suppress fungal, bacterial, viral and even insect plant pathogens. These biocontrol activities are elicited primarily through the production of secreted exoenzymes and secondary metabolites that ma...

  13. Tick control: trapping, biocontrol, host management and other alternative strategies

    USGS Publications Warehouse

    Ginsberg, Howard S.; Edited by Sonenshine, Daniel E.; Roe, R. Michael

    2014-01-01

    Biology of Ticks is the most comprehensive work on tick biology and tick-borne diseases. This second edition is a multi-authored work, featuring the research and analyses of renowned experts across the globe. Spanning two volumes, the book examines the systematics, biology, structure, ecological adaptations, evolution, genomics and the molecular processes that underpin the growth, development and survival of these important disease-transmitting parasites. Also discussed is the remarkable array of diseases transmitted (or caused) by ticks, as well as modern methods for their control. This book should serve as a modern reference for students, scientists, physicians, veterinarians and other specialists. Volume I covers the biology of the tick and features chapters on tick systematics, tick life cycles, external and internal anatomy, and others dedicated to specific organ systems, specifically, the tick integument, mouthparts and digestive system, salivary glands, waste removal, salivary glands, respiratory system, circulatory system and hemolymph, fat body, the nervous and sensory systems and reproductive systems. Volume II includes chapters on the ecology of non-nidicolous and nidicolous ticks, genetics and genomics (including the genome of the Lyme disease vector Ixodes scapularis) and immunity, including host immune responses to tick feeding and tick-host interactions, as well as the tick's innate immune system that prevents and/or controls microbial infections. Six chapters cover in depth the many diseases caused by the major tick-borne pathogens, including tick-borne protozoa, viruses, rickettsiae of all types, other types of bacteria (e.g., the Lyme disease agent) and diseases related to tick paralytic agents and toxins. The remaining chapters are devoted to tick control using vaccines, acaricides, repellents, biocontrol, and, finally, techniques for breeding ticks in order to develop tick colonies for scientific study.

  14. Biocontrol of collar rot disease of betelvine (Piper betle L.) caused by Sclerotium rolfsii by using rhizosphere-competent Pseudomonas fluorescens NBRI-N6 and P. fluorescens NBRI-N.

    PubMed

    Singh, Anand; Mehta, Sangeeta; Singh, Harikesh Bahadur; Nautiyal, Chandra Shekhar

    2003-08-01

    Collar rot disease of betelvine (Piper betle L.) caused by Sclerotium rolfsii is difficult to control by conventional means by use of chemicals; therefore, use of biocontrol agents is desirable. In the present study, 186 bacterial strains of different morphological types were screened for their biocontrol activity against S. rolfsii under in vitro conditions. Two strains, Pseudomonas fluorescens NBRI-N6 and P. fluorescens NBRI-N, were selected for further studies because of their ability to inhibit the mycelial growth of the pathogen significantly. Spontaneous rifampicin-resistant (Rif) derivatives of P. fluorescens NBRI-N6 and P. fluorescens NBRI-N showing growth rate and membrane protein composition comparable to the wild type were selected to facilitate their monitoring in the rhizosphere. Field trials demonstrated that strain P. fluorescens NBRI-N6 was better than P. fluorescens NBRI-N in increasing the yield of betelvine significantly, whereas a consortium of the two strains controlled the disease more than either of the strains. The screening method should prove useful in identifying rhizosphere bacteria with the greatest potential for controlling diseases caused by phytopathogenic fungi. PMID:14506865

  15. Omega-3 fatty acid is a potential preventive agent for recurrent colon cancer.

    PubMed

    Vasudevan, Anita; Yu, Yingjie; Banerjee, Sanjeev; Woods, James; Farhana, Lulu; Rajendra, Sindhu G; Patel, Aamil; Dyson, Gregory; Levi, Edi; Maddipati, Krishna Rao; Majumdar, Adhip P N; Nangia-Makker, Pratima

    2014-11-01

    Increasing evidence supports the contention that many malignancies, including sporadic colorectal cancer, are driven by the self-renewing, chemotherapy-resistant cancer stem/stem-like cells (CSC/CSLC), underscoring the need for improved preventive and therapeutic strategies targeting CSCs/CSLCs. Omega-3 polyunsaturated fatty acids (ω-3 PUFA), have been reported to inhibit the growth of primary tumors, but their potential as a preventive agent for recurring cancers is unexplored. The primary objectives of this investigation are (i) to examine whether eicosapentaenoic acid (EPA; one of the ω-3 PUFA) synergizes with FuOx (5-FU+Oxaliplatin), the backbone of colon cancer chemotherapy, and (ii) whether EPA by itself or in combination with conventional chemotherapy prevents the recurrence of colon cancer via eliminating/suppressing CSCs/CSLCs. FuOx-resistant (chemoresistant; CR) colon cancer cells, highly enriched in CSCs, were used for this study. Although EPA alone was effective, combination of EPA and FuOx was more potent in (i) inhibiting cell growth, colonosphere formation, and sphere-forming frequency, (ii) increasing sphere disintegration, (iii) suppressing the growth of SCID mice xenografts of CR colon cancer cells, and (iv) decreasing proinflammatory metabolites in mice. In addition, EPA + FuOx caused a reduction in CSC/CSLC population. The growth reduction by this regimen is the result of increased apoptosis as evidenced by PARP cleavage. Furthermore, increased pPTEN, decreased pAkt, normalization of β-catenin expression, localization, and transcriptional activity by EPA suggests a role for the PTEN-Akt axis and Wnt signaling in regulating this process. Our data suggest that EPA by itself or in combination with FuOx could be an effective preventive strategy for recurring colorectal cancer.

  16. Pharmacological characterization of a novel gastrodin derivative as a potential anti-migraine agent.

    PubMed

    Wang, Ping-Han; Zhao, Li-Xue; Wan, Jing-Yu; Zhang, Liang; Mao, Xiao-Na; Long, Fang-Yi; Zhang, Shuang; Chen, Chu; Du, Jun-Rong

    2016-03-01

    Migraine is a highly prevalent neurovascular disorder in the brain. An optimal therapy for migraine has not yet been developed. Gastrodin (Gas), the main effective constitute from Gastrodiae Rhizoma (Tianma in Chinese), has been indicated for migraine treatment and prophylaxis more than 30 years, with demonstrated safety. However, Gas is a phenolic glycoside, with relatively low concentrations and weak efficacy in the central nervous system. To develop more effective anti-migraine agents, we synthesized a novel Gas derivative (Gas-D). In the present study, comparative pharmacodynamic evaluations of Gas and Gas-D were performed in a model of nitroglycerin (NTG)-induced migraine in rats and the hot-plate test in mice. Following behavioral testing in this migraine model, external jugular vein blood and the trigeminal nucleus caudalis (TNC) were collected to analyze plasma nitric oxide (NO) and calcitonin gene-related peptide (CGRP) concentrations and c-Fos expression in the TNC. The acute oral toxicity of Gas and Gas-D was also examined. We found that Gas-D had potent anti-migraine effects, likely attributable to inhibition of both trigeminal nerve activation at central sites and the peripheral release of CGRP following NO scavenging. Additionally, Gas-D exerted significant anti-nociceptive effect in response to thermal pain compared with Gas. Furthermore, a single dose of 2.048 g/kg Gas or Gas-D presented no acute oral toxicity in mice. Altogether, the potent anti-migraine and anti-hyperalgesic effects of Gas-D suggest that it might be a potentially novel drug candidate for migraine treatment or prophylaxis. PMID:26704993

  17. Pharmacological characterization of a novel gastrodin derivative as a potential anti-migraine agent.

    PubMed

    Wang, Ping-Han; Zhao, Li-Xue; Wan, Jing-Yu; Zhang, Liang; Mao, Xiao-Na; Long, Fang-Yi; Zhang, Shuang; Chen, Chu; Du, Jun-Rong

    2016-03-01

    Migraine is a highly prevalent neurovascular disorder in the brain. An optimal therapy for migraine has not yet been developed. Gastrodin (Gas), the main effective constitute from Gastrodiae Rhizoma (Tianma in Chinese), has been indicated for migraine treatment and prophylaxis more than 30 years, with demonstrated safety. However, Gas is a phenolic glycoside, with relatively low concentrations and weak efficacy in the central nervous system. To develop more effective anti-migraine agents, we synthesized a novel Gas derivative (Gas-D). In the present study, comparative pharmacodynamic evaluations of Gas and Gas-D were performed in a model of nitroglycerin (NTG)-induced migraine in rats and the hot-plate test in mice. Following behavioral testing in this migraine model, external jugular vein blood and the trigeminal nucleus caudalis (TNC) were collected to analyze plasma nitric oxide (NO) and calcitonin gene-related peptide (CGRP) concentrations and c-Fos expression in the TNC. The acute oral toxicity of Gas and Gas-D was also examined. We found that Gas-D had potent anti-migraine effects, likely attributable to inhibition of both trigeminal nerve activation at central sites and the peripheral release of CGRP following NO scavenging. Additionally, Gas-D exerted significant anti-nociceptive effect in response to thermal pain compared with Gas. Furthermore, a single dose of 2.048 g/kg Gas or Gas-D presented no acute oral toxicity in mice. Altogether, the potent anti-migraine and anti-hyperalgesic effects of Gas-D suggest that it might be a potentially novel drug candidate for migraine treatment or prophylaxis.

  18. Synthesis, functionalization, and characterization of rod-shaped gold nanoparticles as potential optical contrast agents

    NASA Astrophysics Data System (ADS)

    Rayavarapu, R. G.; Petersen, W.; Le Gac, S.; Ungureanu, C.; van Leeuwen, T. G.; Manohar, S.

    2007-07-01

    Gold nanoparticles exhibit intense and narrow optical extinction bands due to the phenomenon of plasmon resonance making them useful as contrast agents for light-based imaging techniques. Localized heating results from the absorbed light energy, which shows potential for these particles in photothermal therapy as well. The bioconjugation of gold nanoparticles to appropriate antibodies targeted to tumors in vivo, could make highly selective detection and therapy of tumors possible. We have synthesised gold nanorods based on seed mediated protocols using two methods. The first method is based on using a mono-surfactant silver assisted method which produces gold nanorods having plasmon peaks between 670-850 nm within the "optical imaging and therapeutic window". These nanorods have aspect ratios between 2.3 - 3.7. A second method is a silver assisted bi-surfactant method which produce nanorods with peaks in the range of 850-1100 nm having aspect ratios between 5 - 11. Typical concentrations of these particles in aqueous dispersions are in the range of 1x10 10 - 1x10 11 particles per mL. We have bioconjugated these gold nanorods with anti-HER2/neu mouse monoclonal antibodies (MAb). Since the as-prepared CTAB-stabilized nanorods were found to be toxic to SKBR3 cells, we decided to coat the gold nanorods with polyethylene glycol (PEG). Characterization and size estimation of the nanoparticles were performed using electron microscopies, optical spectroscopy and confocal microscopy. We present these results and implications for use of these nanoparticles for in vivo biomedical applications.

  19. Identification of novel class of falcipain-2 inhibitors as potential antimalarial agents.

    PubMed

    Chakka, Sai Kumar; Kalamuddin, Mohammad; Sundararaman, Srividhya; Wei, Lianhu; Mundra, Sourabh; Mahesh, Radhakrishnan; Malhotra, Pawan; Mohmmed, Asif; Kotra, Lakshmi P

    2015-05-01

    Falcipain-2 is a papain family cysteine protease and an emerging antimalarial drug target. A pseudo-tripeptide scaffold I was designed using in silico screening tools and the three dimensional structures of falcipain-2, falcipain-3, and papain. This scaffold was investigated at four positions, T1, T2, T3, and T3', with various targeted substitutions to understand the structure-activity relationships. Inhibitor synthesis was accomplished by first obtaining the appropriate dipeptide precursors with common structural components. The pyrrolidine moiety introduced interesting rotamers in a number of synthesized molecules, which was confirmed using high-temperature (1)H NMR spectroscopy. Among the synthesized compounds, 61, 62, and 66 inhibited falcipain-2 activity with inhibition constants (Ki) of 1.8 ± 1.1, 0.2 ± 0.1 and 7.0 ± 2.3 μM, respectively. A group of molecules with a pyrrolidine moiety at the T2 position (68, 70, 71, 72, and 73) also potently inhibited falcipain-2 activity (Ki=0.4 ± 0.1, 2.5 ± 0.5, 3.3 ± 1.1, 7.5 ± 1.9, and 4.6 ± 0.7 μM, respectively). Overall, compound 74 exhibited potent anti-parasitic activity (IC₅₀=0.9 ± 0.1 μM), corresponding with its inhibitory activity against falcipain-2, with a Ki of 1.1 ± 0.1 μM. Compounds 62 and 67 inhibited the growth of the drug resistant parasite Dd2 with better efficacy, and compound 74 exhibited a 7- to 12-fold higher potency against Dd2 and MCamp isolates, than the laboratory strain (3D7). These data suggest that this novel series of compounds should be further investigated as potential antimalarial agents. PMID:25840796

  20. Whole-Genome Sequence of Pseudomonas graminis Strain UASWS1507, a Potential Biological Control Agent and Biofertilizer Isolated in Switzerland

    PubMed Central

    Crovadore, Julien; Calmin, Gautier; Chablais, Romain; Cochard, Bastien; Schulz, Torsten

    2016-01-01

    We report here the whole-genome shotgun sequence of the strain UASWS1507 of the species Pseudomonas graminis, isolated in Switzerland from an apple tree. This is the first genome registered for this species, which is considered as a potential and valuable resource of biological control agents and biofertilizers for agriculture. PMID:27795260