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Sample records for antagonize vibrio anguillarum

  1. Disruption of Cell-to-Cell Signaling Does Not Abolish the Antagonism of Phaeobacter gallaeciensis toward the Fish Pathogen Vibrio anguillarum in Algal Systems

    DEFF Research Database (Denmark)

    Prol García, María Jesús; D'Alvise, Paul; Gram, Lone

    2013-01-01

    Quorum sensing (QS) regulates Phaeobacter gallaeciensis antagonism in broth systems; however, we demonstrate here that QS is not important for antagonism in algal cultures. QS mutants reduced Vibrio anguillarum to the same extent as the wild type. Consequently, a combination of probiotic Phaeobac...... Phaeobacter and QS inhibitors is a feasible strategy for aquaculture disease control....

  2. The phosphotransferase VanU represses expression of four qrr genes antagonizing VanO-mediated quorum-sensing regulation in Vibrio anguillarum.

    Science.gov (United States)

    Weber, Barbara; Lindell, Kristoffer; El Qaidi, Samir; Hjerde, Erik; Willassen, Nils-Peder; Milton, Debra L

    2011-12-01

    Vibrio anguillarum utilizes quorum sensing to regulate stress responses required for survival in the aquatic environment. Like other Vibrio species, V. anguillarum contains the gene qrr1, which encodes the ancestral quorum regulatory RNA Qrr1, and phosphorelay quorum-sensing systems that modulate the expression of small regulatory RNAs (sRNAs) that destabilize mRNA encoding the transcriptional regulator VanT. In this study, three additional Qrr sRNAs were identified. All four sRNAs were positively regulated by σ(54) and the σ(54)-dependent response regulator VanO, and showed a redundant activity. The Qrr sRNAs, together with the RNA chaperone Hfq, destabilized vanT mRNA and modulated expression of VanT-regulated genes. Unexpectedly, expression of all four qrr genes peaked at high cell density, and exogenously added N-acylhomoserine lactone molecules induced expression of the qrr genes at low cell density. The phosphotransferase VanU, which phosphorylates and activates VanO, repressed expression of the Qrr sRNAs and stabilized vanT mRNA. A model is presented proposing that VanU acts as a branch point, aiding cross-regulation between two independent phosphorelay systems that activate or repress expression of the Qrr sRNAs, giving flexibility and precision in modulating VanT expression and inducing a quorum-sensing response to stresses found in a constantly changing aquatic environment.

  3. Stress response and virulence in Vibrio anguillarum

    OpenAIRE

    Weber, Barbara

    2010-01-01

    Bacteria use quorum sensing, a cell to cell signaling mechanism mediated by small molecules that are produced by specific signal molecule synthases, to regulate gene expression in response to population density. In Vibrio anguillarum, the quorum-sensing phosphorelay channels information from three hybrid sensor kinases VanN, VanQ, CqsS that sense signal molecules produced by the synthases VanM, VanS and CqsA, onto the phosphotransferase VanU, to regulate activity of the response regulator Van...

  4. Continuous Exposure Of Vibrio Anguillarum To Tropodithietic Acid: Genetic Changes And Influence On Virulence

    DEFF Research Database (Denmark)

    Rasmussen, Bastian Barker; D'Alvise, Paul; Grotkjær, Torben

    2015-01-01

    Introduction: The fish pathogen Vibrio anguillarum is a major problem in aquaculture causing Vibriosis. Bacteria of the Roseobacter clade can antagonize pathogenic vibrios in cultures in live feed such as microalgae, rotifers and Artemia, as well as in fish larvae. Therefore, roseobacters could...

  5. Vibriophages and Their Interactions with the Fish Pathogen Vibrio anguillarum

    DEFF Research Database (Denmark)

    Tan, Demeng; Gram, Lone; Middelboe, Mathias

    2014-01-01

    Vibrio anguillarum is an important pathogen in aquaculture, responsible for the disease vibriosis in many fish and invertebrate species. Disease control by antibiotics is a concern due to potential development and spread of antibiotic resistance. The use of bacteriophages to control the pathogen...... patterns of the individual host isolates, key phenotypic properties related to phage susceptibility are distributed worldwide and maintained in the global Vibrio community for decades. The phage susceptibility pattern of the isolates did not show any relation to the physiological relationships obtained...... from Biolog GN2 profiles, demonstrating that similar phage susceptibility patterns occur across broad phylogenetic and physiological differences in Vibrio strains. Subsequent culture experiments with two phages and two V. anguillarum hosts demonstrated an initial strong lytic potential of the phages...

  6. Inhibition of Vibrio anguillarum by Pseudomonas fluorescens AH2, a possible probiotic treatment of fish

    DEFF Research Database (Denmark)

    Gram, Lone; Melchiorsen, Jette; Spanggaard, Bettina

    1999-01-01

    To study the possible use of probiotics in fish farming, we evaluated the in vitro and in vivo antagonism of antibacterial strain Pseudomonas fluorescens strain AH2 against the fish- pathogenic bacterium Vibrio anguillarum. As iron is important in virulence and bacterial interactions, the effect....... fluorescens AH2 inhibited the growth of V. anguillarum during coculture, independently of the iron concentration, when the initial count of the antagonist was 100 to 1,000 times greater that of the fish pathogen. These in vitro results were successfully repeated in vivo. A probiotic effect in vivo was tested...... by exposing rainbow trout (Oncorynchus mykiss Walbaum) to P. fluorescens AH2 at a density of 10(5) CFU/ml for 5 days before a challenge with V. anguillarum at 10(4) to 10(5) CFU/ml for 1 h. Some fish were also exposed to P. fluorescens AH2 at 10(7) CFU/ml during the 1-h infection. The combined probiotic...

  7. Complete genome sequence of Vibrio anguillarum phage CHOED successfully used for phage therapy in aquaculture

    DEFF Research Database (Denmark)

    Romero, Jaime; Higuera, Gastón; Gajardo, Felipe

    2014-01-01

    Vibrio anguillarum phage CHOED was isolated from Chilean mussels. It is a virulent phage showing effective inhibition of V. anguillarum. CHOED has potential in phage therapy, because it can protect fish from vibriosis in fish farms. Here, we announce the completely sequenced genome of V....... anguillarum phage CHOED....

  8. Exploring the Effect of Phage Therapy in Preventing Vibrio anguillarum Infections in Cod and Turbot Larvae

    DEFF Research Database (Denmark)

    Rørbo, Nanna; Rønneseth, Anita; Kalatzis, Panos G.

    2018-01-01

    The aquaculture industry is suffering from losses associated with bacterial infections by opportunistic pathogens. Vibrio anguillarum is one of the most important pathogens, causing vibriosis in fish and shellfish cultures leading to high mortalities and economic losses. Bacterial resistance to a...... KVP40, demonstrating that the phage could also reduce mortality imposed by the background population of pathogens. Overall, phage-mediated reduction in mortality of cod and turbot larvae in experimental challenge assays with V. anguillarum pathogens suggested that application of broad...

  9. Determining Vaccination Frequency in Farmed Rainbow Trout Using Vibrio anguillarum O1 Specific Serum Antibody Measurements

    DEFF Research Database (Denmark)

    Holten-Andersen, Lars; Dalsgaard, Inger; Nylén, Jørgen

    2012-01-01

    Background Despite vaccination with a commercial vaccine with a documented protective effect against Vibrio anguillarum O1 disease outbreaks caused by this bacterium have been registered among rainbow trout at Danish fish farms. The present study examined specific serum antibody levels as a valid...

  10. Oral administration of formalin killed Vibrio anguillarum cells improves growth and protection against challenge with Vibrio harveyi in banana shrimp.

    Science.gov (United States)

    Patil, P K; Gopal, C; Panigrahi, A; Rajababu, D; Pillai, S M

    2014-03-01

    Larval rearing in hatcheries and highly intensive grow-out culture practices followed in shrimp production systems favour the growth of potential pathogenic bacterial loads. This study reports the efficacy of formalin-killed vibrio bacterin on growth, survival and protection to challenge with virulent Vibrio harveyi and Vibrio anguillarum in juveniles of banana shrimp Fenneropenaeus merguiensis. Postlarvae 15 (0·24 ± 0·01 g) were administered orally in different concentrations of bacterial preparation (0, 10(6) , 10(8) , 10(10) and 10(12 ) CFU kg(-1) feed) for a period of 6 weeks. Physicochemical and microbial quality of water in larval rearing tanks, and growth and survival of the postlarvae were monitored at regular intervals, and body composition was estimated at the end of the experiment. Shrimps were challenged with V. harveyi and V. anguillarum, and cumulative mortality was calculated. The group receiving 10(8)  CFU kg(-1) feed showed highest average weight gain (162·66 ± 22·94 mg) and survival (90·33 ± 4·5%) and lowest cumulative mortality following the challenge with V. anguillarum (26%) and V. harveyi (36·67%). The results of the study suggest that formalized vibrio administered orally to F. merguiensis postlarvae could induce both homologous and heterologous protection against V. anguillarum and V. harveyi. 'Vaccination' of shrimp postlarvae at hatcheries would help in preventing the losses due to vibriosis and the most susceptible stages of shrimp development. The study demonstrates the cross-protection offered by the oral feeding of formalin-killed Vibrio anguillarum against pathogenic V. harveyi challenge at the early developmental stages of banana shrimp, Fenneropenaeus merguiensis. © 2013 The Society for Applied Microbiology.

  11. Phaeobacter gallaeciensis Reduces Vibrio anguillarum in Cultures of Microalgae and Rotifers, and Prevents Vibriosis in Cod Larvae

    Science.gov (United States)

    D’Alvise, Paul W.; Lillebø, Siril; Prol-Garcia, Maria J.; Wergeland, Heidrun I.; Nielsen, Kristian F.; Bergh, Øivind; Gram, Lone

    2012-01-01

    Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 107 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA) did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua) to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect. PMID:22928051

  12. Phaeobacter gallaeciensis reduces Vibrio anguillarum in cultures of microalgae and rotifers, and prevents vibriosis in cod larvae.

    Directory of Open Access Journals (Sweden)

    Paul W D'Alvise

    Full Text Available Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect.

  13. Molecular cloning of the recA analog from the marine fish pathogen Vibrio anguillarum 775

    International Nuclear Information System (INIS)

    Singer, J.T.

    1989-01-01

    The recA analog from Vibrio anguillarum 775 was isolated by complementation of recA mutations in Escherichia coli, and its protein product was identified. The recA analog promoted recombination between two partially deleted lactose operons, stimulated both spontaneous and mitomycin C-induced phage production in RecA- lambda lysogens, and restored near wild-type levels of resistance to UV radiation and methyl methanesulfonate

  14. Colonization of fish skin is vital for Vibrio anguillarum to cause disease.

    Science.gov (United States)

    Weber, Barbara; Chen, Chang; Milton, Debra L

    2010-02-01

    Vibrio anguillarum causes a fatal haemorrhagic septicaemia in marine fish. During initial stages of infection, host surfaces are colonized; however, few virulence factors required for colonization of the host are identified. In this study, in vivo bioluminescent imaging was used to analyse directly the colonization of the whole rainbow trout animal by V. anguillarum. The wild type rapidly colonized both the skin and the intestines by 24 h; however, the bacterial numbers on the skin were significantly higher than in the intestines indicating that skin colonization may be important for disease to occur. Mutants defective for the anguibactin iron uptake system, exopolysaccharide transport, or Hfq, an RNA chaperone, were attenuated for virulence, did not colonize the skin, and penetrated skin mucus less efficiently than the wild type. These mutants, however, did colonize the intestines and were as resistant to 2% bile salts as is the wild type. Moreover, exopolysaccharide mutants were significantly more sensitive to lysozyme and antimicrobial peptides, while the Hfq and anguibactin mutants were sensitive to lysozyme compared with the wild type. Vibrio anguillarum encodes several mechanisms to protect against antimicrobial components of skin mucus enabling an amazingly abundant growth on the skin enhancing its disease opportunities. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  15. Proteomic and metabolomic responses in hepatopancreas of Mytilus galloprovincialis challenged by Micrococcus luteus and Vibrio anguillarum.

    Science.gov (United States)

    Wu, Huifeng; Ji, Chenglong; Wei, Lei; Zhao, Jianmin; Lu, Hongjian

    2013-12-06

    The outbreak of pathogens can induce diseases and lead to massive mortalities of aquaculture animals including fish, mollusk and shrimp. In this work, the responses induced by Micrococcus luteus and Vibrio anguillarum were investigated in hepatopancreas of mussel Mytilus galloprovincialis using proteomics and metabolomics. Metabolic biomarkers demonstrated that M. luteus and V. anguillarum injections could induce osmotic stress and disturbance in energy metabolism. And the uniquely and more markedly altered metabolic biomarkers (glutamine, succinate, aspartate, glucose, ATP, homarine and tyrosine) indicated that V. anguillarum could cause more severe disturbances in osmotic regulation and energy metabolism. The differentially altered proteins meant that M. luteus and V. anguillarum induced different effects in mussels. However, the common proteomic biomarkers, arginine kinase and small heat shock protein, demonstrated that these two bacteria induced similar effects including oxidative stress and disturbance in energy metabolism in M. galloprovincialis. In addition, some metabolic biomarkers, ATP and glutamine, were confirmed by related proteins including arginine kinase, ATP synthase, nucleoside diphosphate kinase and glutamine synthetase in bacteria-challenged mussels. This study demonstrated that proteomics and metabolomics could provide an insightful view into the effects of environmental pathogens to the marine mussel M. galloprovincialis. The outbreak of pathogens can lead to diseases and massive mortalities of aquaculture animals including fish, mollusk and shrimp. The mussel M. galloprovincialis distributes widely along the Bohai coast and is popularly consumed as delicious seafood by local residents. This bivalve has become one of the important species in marine aquaculture industry in China. Therefore a study on pathogen-induced effects is necessary. In the present study, an integrated metabolomic and proteomic approach was used to elucidate the

  16. Vibriophages differentially influence biofilm formation by Vibrio anguillarum strains

    DEFF Research Database (Denmark)

    Tan, Demeng; Dahl, Amalie; Middelboe, Mathias

    2015-01-01

    different effects on the biofilm development. Addition of phage ΦH20 to strain BA35 showed efficient control of biofilm formation and density of free-living cells. The interactions between BA35 and ΦH20 were thus characterized by a strong phage control of the phage-sensitive population and subsequent...... against phage infection. By the formation of biofilms, strain PF430-3 created spatial refuges that protected the host from phage infection and allowed coexistence between phage-sensitive cells and lytic phage KVP40. Together, the results demonstrate highly variable phage protection mechanisms in two......-living and surface-associated growth conditions. In this study, we explored in vitro phage-host interactions in two different strains of V. anguillarum (BA35 and PF430-3) during growth in microcolonies, biofilms, and free-living cells. Two vibriophages, ΦH20 (Siphoviridae) and KVP40 (Myoviridae), had completely...

  17. Bacteriophage interactions with Vibrio anguillarum and the potential for phage therapy in marine aquaculture

    DEFF Research Database (Denmark)

    Rørbo, Nanna Iben

    is widespread in the Vibrio community which underscore the lysogenic phages influence on bacterial evolution and functional properties. Highly genetically similar Vibrio phages, termed H20-like prophages, were isolated across large geographical scales being present both as freeliving phages and as prophages...... in V. anguillarum genomes. The H20-like phages’ widespread presence suggests a mutualistic interaction which selects for co-existence with V. anguillarum. In aquaculture, especially the larvae and fry are vulnerable to pathogens, and they are not susceptible to alternatives to antibiotics, e...

  18. Quorum sensing determines the choice of antiphage defense strategy in Vibrio anguillarum

    DEFF Research Database (Denmark)

    Tan, Demeng; Svenningsen, Sine Lo; Middelboe, Mathias

    2015-01-01

    of the outcome of phage-bacterial encounters in the fish pathogen Vibrio anguillarum is bacterial cell-cell communication, known as quorum sensing. Specifically, V. anguillarum PF430-3 cells locked in the low-cell-density state (ΔvanT mutant) express high levels of the phage receptor OmpK, resulting in a high...... susceptibility to phage KVP40, but achieve protection from infection by enhanced biofilm formation. By contrast, cells locked in the high-cell-density state (ΔvanΟ mutant) are almost completely unsusceptible due to quorum-sensing-mediated downregulation of OmpK expression. The phenotypes of the two quorum......-sensing mutant strains are accurately reflected in the behavior of wild-type V. anguillarum, which (i) displays increased OmpK expression in aggregated cells compared to free-living variants in the same culture, (ii) displays a clear inverse correlation between ompK mRNA levels and the concentration of N...

  19. Pathogenicity of Vibrio anguillarum serogroup O1 strains compared to plasmids, outer membrane protein profiles and siderophore production

    DEFF Research Database (Denmark)

    Pedersen, K.; Gram, Lone; Austin, D.A.

    1997-01-01

    The virulence of 18 strains of Vibrio anguillarum serogroup 01 was compared to plasmid content, expression of siderophores and outer membrane proteins. All strains, irrespective of plasmid content, produced siderophores and inducible outer membrane proteins under iron-limited conditions. Only str...

  20. Development of a two-step, non-probed multiplex real-time PCR for surveilling Vibrio anguillarum in seawater

    Science.gov (United States)

    Vibrio anguillarum is an aggressive and halophilic bacterial pathogen commonly found in seawater. Its presence in aquaculture facilities causes significant morbidity and mortality among aquaculture species primarily from hemorrhaging of the body and skin of the infected fish that eventually leads t...

  1. Protective efficacy of six immunogenic recombinant proteins of Vibrio anguillarum and evaluation them as vaccine candidate for flounder (Paralichthys olivaceus).

    Science.gov (United States)

    Xing, Jing; Xu, Hongsen; Wang, Yang; Tang, Xiaoqian; Sheng, Xiuzhen; Zhan, Wenbin

    2017-06-01

    Vibrio anguillarum is a severe bacterium that causes terminal haemorrhagic septicaemia in freshwater and marine fish. Virulence-associated proteins play an important role in bacterial pathogenicity and could be applied for immunoprophylaxis. In this study, six antigenic proteins from V. anguillarum were selected and the immune protective efficacy of their recombinant proteins was investigated. VirA, CheR, FlaC, OmpK, OmpR and Hsp33 were recombinantly produced and the reactions of recombinant proteins to flounder-anti-V. anguillarum antibodies (fV-ab) were detected, respectively. Then the recombinant proteins were injected to fish, after immunization, the percentages of surface membrane immunoglobulin-positive (sIg+) cell in lymphocytes, total antibodies, antibodies against V. anguillarum, antibodies against recombinant proteins and relative percent survival (RPS) were analyzed, respectively. The results showed that all the recombinant proteins could react to fV-ab, proliferate sIg + cells in lymphocytes and induce production of total antibodies, specific antibodies against V. anguillarum or the recombinant proteins; the RPS of rVirA, rCheR, rFlaC, rOmpK, rOmpR and rHsp33 against V. anguillarum was 70.27%, 27.03%, 16.22%, 62.16%, 45.95% and 81.08%, respectively. The results revealed that rHsp33, rVirA and rOmpK have good protections against V. anguillarum and could be vaccine candidates against V. anguillarum. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Vibrio anguillarum Is Genetically and Phenotypically Unaffected by Long-Term Continuous Exposure to the Antibacterial Compound Tropodithietic Acid

    DEFF Research Database (Denmark)

    Rasmussen, Bastian Barker; Grotkjær, Torben; D'Alvise, Paul

    2016-01-01

    unaffected, supporting the application of TDA-producing roseobacters as probiotics in aquaculture. It is important to limit the use of antibiotics in our food production, to reduce the risk of bacteria developing antibiotic resistance. We showed previously that marine bacteria of the Roseobacter clade can......Minimizing the use of antibiotics in the food production chain is essential for limiting the development and spread of antibiotic-resistant bacteria. One alternative intervention strategy is the use of probiotic bacteria, and bacteria of the marine Roseobacter clade are capable of antagonizing fish...... potential side effects of long-term exposure of the pathogen to the probionts or any compounds they produce. Here we exposed the fish pathogen Vibrio anguillarum to TDA for several hundred generations in an adaptive evolution experiment. No tolerance or resistance arose during the 90 days of exposure...

  3. Exploration of Phage-Host Interactions in Fish Pathogen Vibrio anguillarum and Anti-Phage Defense Strategies

    DEFF Research Database (Denmark)

    Tan, Demeng

    The disease vibriosis is caused by the bacterial pathogen Vibrio anguillarum and results in large losses in aquaculture both in Denmark and around the world. Antibiotics have been widely used in antimicrobial prophylaxis and treatment of vibriosis. Recently, numerous multidrug-resistant strains...... of V. anguillarum have been isolated, indicating that antibiotic use has to be restricted and alternatives have to be developed. Lytic phages have been demonstrated to play an essential role in preventing bacterial infection. However, phages are also known to play a critical role in the evolution...... of bacterial pathogenicity development. Therefore, successful application of phage therapy in the treatment of vibriosis requires a detailed understanding of phage-host interactions, especially with regards to anti-phage defense mechanisms in the host. Part I. As a first approach, 24 V. anguillarum and 13...

  4. Gel shift analysis of the empA promoter region in Vibrio anguillarum

    Directory of Open Access Journals (Sweden)

    Denkin Steven M

    2004-10-01

    Full Text Available Abstract Background The induction of metalloprotease encoded by empA in Vibrio anguillarum occurs at high cell density in salmon intestinal mucus. Previously we have shown that there are significant differences in empA expression in two strains of V. anguillarum, M93Sm and NB10. It is hypothesized that differences in empA regulation are due to differences in binding of regulatory elements. Results Two strains of V. anguillarum, M93Sm and NB10, were examined and compared for the presence of DNA regulatory proteins that bind to and control the empA promoter region. Gel mobility shift assays, using a digoxigenin (DIG-labeled oligomer containing a lux box-like element and the promoter for empA, were done to demonstrate the presence of a DNA-binding protein. Protein extracts from NB10 cells incubated in Luria Bertani broth + 2% NaCl (LB20, nine salts solution + 200 μg/ml mucus (NSSM, 3M (marine minimal medium, or NSS resulted in a gel mobility shift. No gel mobility shift was seen when protein extracts from either LB20- or NSSM-grown M93Sm cells were mixed with the DIG-labeled empA oligomer. The azocasein assay detected protease activity in all incubation conditions for NB10 culture supernatants. In contrast, protease activity was detected in M93Sm culture supernatants only when incubated in NSSM. Since the luxR homologue in V. anguillarum, vanT, has been cloned, sequenced, and shown to be required for protease activity, we wanted to determine if vanT mutants of NB10 exhibit the same gel shift observed in the wild-type. Site-directed mutagenesis was used to create vanT mutants in V. anguillarum M93Sm and NB10 to test whether VanT is involved with the gel mobility shift. Both vanT mutants, M02 and NB02, did not produce protease activity in any conditions. However, protein extracts from NB02 incubated in each condition still exhibited a gel shift when mixed with the DIG-labeled empA oligomer. Conclusions The data demonstrate that protein extracts of V

  5. Profiling of acylated homoserine lactones of Vibrio anguillarum in vitro and in vivo: influence of growth conditions and serotype

    DEFF Research Database (Denmark)

    Buchholtz, Chrstiane; Nielsen, Kristian Fog; L. Milton, Debra

    2006-01-01

    Vibrio anguillarum produces several interlinked acylated homoserine lactone (AHL) signal molecules which may Vibrio anguillarum produces several interlinked acylated homoserine lactone (AHL) signal molecules which may influence expression of its virulence factors such as exoprotease production...... concentration) has little influence on the AHL-profile. Most strains produced N-(3-oxodecanoyl)-l-homoserine lactone (3-oxo-C10-HSL) and N-(3-hydroxy-hexanoyl)-l-homoserine lactone (3-hydroxy-C6-HSL) as the dominant molecules. Also, two spots with AHL activity appeared on TLC plates, which could...... not be identified as AHL structures. Trace amounts of N-(3-hydroxy-octanoyl)-l-homoserine lactone, N-(3-hydroxy-decanoyl)-l-homoserine lactone and N-(3-hydroxy-dodecanoyl)-l-homoserine lactone (3-hydroxy-C8-HSL, 3-hydroxy-C10-HSL and 3-oxo-C12-HSL, respectively) were also detected by HPLC-HRMS analysis from...

  6. Complete genome sequence of Vibrio anguillarum strain NB10, a virulent isolate from the Gulf of Bothnia.

    Science.gov (United States)

    Holm, Kåre Olav; Nilsson, Kristina; Hjerde, Erik; Willassen, Nils-Peder; Milton, Debra L

    2015-01-01

    Vibrio anguillarum causes a fatal hemorrhagic septicemia in marine fish that leads to great economical losses in aquaculture world-wide. Vibrio anguillarum strain NB10 serotype O1 is a Gram-negative, motile, curved rod-shaped bacterium, isolated from a diseased fish on the Swedish coast of the Gulf of Bothnia, and is slightly halophilic. Strain NB10 is a virulent isolate that readily colonizes fish skin and intestinal tissues. Here, the features of this bacterium are described and the annotation and analysis of its complete genome sequence is presented. The genome is 4,373,835 bp in size, consists of two circular chromosomes and one plasmid, and contains 3,783 protein-coding genes and 129 RNA genes.

  7. RpoS induces expression of the Vibrio anguillarum quorum-sensing regulator VanT.

    Science.gov (United States)

    Weber, Barbara; Croxatto, Antony; Chen, Chang; Milton, Debra L

    2008-03-01

    In vibrios, regulation of the Vibrio harveyi-like LuxR transcriptional activators occurs post-transcriptionally via small regulatory RNAs (sRNAs) that destabilize the luxR mRNA at a low cell population, eliminating expression of LuxR. Expression of the sRNAs is modulated by the vibrio quorum-sensing phosphorelay systems. However, vanT mRNA, which encodes a LuxR homologue in Vibrio anguillarum, is abundant at low and high cell density, indicating that VanT expression may be regulated via additional mechanisms. In this study, Western analyses showed that VanT was expressed throughout growth with a peak of expression during late exponential growth. VanO induced partial destabilization of vanT mRNA via activation of at least one Qrr sRNA. Interestingly, the sigma factor RpoS significantly stabilized vanT mRNA and induced VanT expression during late exponential growth. This induction was in part due to RpoS repressing expression of Hfq, an RNA chaperone. RpoS is not part of the quorum-sensing regulatory cascade since RpoS did not regulate expression or activity of VanO, and RpoS was not regulated by VanO or VanT. VanT and RpoS were needed for survival following UV irradiation and for pigment and metalloprotease production, suggesting that RpoS works with the quorum-sensing systems to modulate expression of VanT, which regulates survival and stress responses.

  8. VanT, a homologue of Vibrio harveyi LuxR, regulates serine, metalloprotease, pigment, and biofilm production in Vibrio anguillarum.

    Science.gov (United States)

    Croxatto, Antony; Chalker, Victoria J; Lauritz, Johan; Jass, Jana; Hardman, Andrea; Williams, Paul; Cámara, Miguel; Milton, Debra L

    2002-03-01

    Vibrio anguillarum possesses at least two N-acylhomoserine lactone (AHL) quorum-sensing circuits, one of which is related to the luxMN system of Vibrio harveyi. In this study, we have cloned an additional gene of this circuit, vanT, encoding a V. harveyi LuxR-like transcriptional regulator. A V. anguillarum Delta vanT null mutation resulted in a significant decrease in total protease activity due to loss of expression of the metalloprotease EmpA, but no changes in either AHL production or virulence. Additional genes positively regulated by VanT were identified from a plasmid-based gene library fused to a promoterless lacZ. Three lacZ fusions (serA::lacZ, hpdA-hgdA::lacZ, and sat-vps73::lacZ) were identified which exhibited decreased expression in the Delta vanT strain. SerA is similar to 3-phosphoglycerate dehydrogenases and catalyzes the first step in the serine-glycine biosynthesis pathway. HgdA has identity with homogentisate dioxygenases, and HpdA is homologous to 4-hydroxyphenylpyruvate dioxygenases (HPPDs) involved in pigment production. V. anguillarum strains require an active VanT to produce high levels of an L-tyrosine-induced brown color via HPPD, suggesting that VanT controls pigment production. Vps73 and Sat are related to Vibrio cholerae proteins encoded within a DNA locus required for biofilm formation. A V. anguillarum Delta vanT mutant and a mutant carrying a polar mutation in the sat-vps73 DNA locus were shown to produce defective biofilms. Hence, a new member of the V. harveyi LuxR transcriptional activator family has been characterized in V. anguillarum that positively regulates serine, metalloprotease, pigment, and biofilm production.

  9. Influence of chlorine on the susceptibility of striped bass (Morone saxatilis) to Vibrio anguillarum

    Energy Technology Data Exchange (ETDEWEB)

    Hetrick, F M; Hall, Jr, L W; Wolski, S; Graves, W C; Roberson, B S

    1984-09-01

    The subtle effects that low levels of pollutants have on fish populations are probably more important than the effects of large spills, since the effects are less likely to be obvious and the source more difficult to detect in time to save the environment. An experiment was carried out to determine if exposure of striped bass to sublethal concentrations of chlorine affected their susceptibility to bacterial infection. Exposure of striped bass for 96 h to sublethal concentrations of total residual chlorine (TRC) (0.05-0.23 mg/L) did not increase their susceptibility to infection with the bacterial pathogen Vibrio anguillarum. Variables examined were TRC concentrations, length of exposure to chlorine, and the order of exposure to chlorine and the pathogen. Mortalities in the groups exposed to both chlorine and pathogen were not significantly different from those seen in groups receiving the bacteria only. Smaller fish are more susceptible than larger fish, and the LD50 is markedly affected by the ambient temperature in that fewer bacteria are needed to kill fish at lower temperatures. One contributing factor to this increased resistance of fish at higher water temperatures appears to be related to their immune status. 29 references, 5 tables.

  10. Production of acylated homoserine lactones by different serotypes of Vibrio anguillarum both in culture and during infection of rainbow trout

    DEFF Research Database (Denmark)

    Buch, C.; Sigh, J.; Nielsen, J.

    2003-01-01

    Onehundred and forty-eight out of onehundred and fifty strains of Vibrio anguillarum isolated from vibriosis in Danish marine aquaculture produced bacterial communication signals, acylated homoserine lactones, eliciting a response in the Agrobacterium tumefaciens (pZLR4) monitoring system. One...... strain, a serotype O4, induced a strong response in the Chromobacterium violaceum (CV026) monitoring system. Profiles of AHLs determined by TLC separation revealed the presence of at least four AHLs and a compound similar to N-3-oxo-decanoyl homoserine lactone (3-oxo-C10-HSL) was present in all strains...

  11. The Roles of Heat Shock Proteins 70 and 90 in Exopalaemon carinicauda After WSSV and Vibrio anguillarum Challenges

    Science.gov (United States)

    Li, Jitao; Li, Jian; Duan, Yafei; Chen, Ping; Liu, Ping

    2018-04-01

    Heat shock proteins (HSPs), such as HSP70 and HSP90, are a suite of highly conserved proteins produced in all cellular organisms when they are exposed to stresses. In aquatic animals, they have been proved to play important roles in response to environmental pollutants and particularly in the non-specific immune responses to pathogen infections. In the present study, the expression profiles of HSP70 and HSP90 genes in hemocytes and hepatopancreas from the ridgetail white prawn Exopalaemon carinicauda infected with WSSV and Vibrio anguillarum were detected using reverse transcription polymerase chain reaction (RT-PCR). After WSSV challenge, the expression level of HSP 70 gene transcripts in the hemocytes and hepatopancreas increased to peak level at 6 h and 48 h, respectively. HSP90 gene transcripts in hemocytes and hepatopancreas were up-regulated significantly at 12 h and 6 h, respectively. During V. anguillarum challenge, the mRNA content of HSP70 gene in hemocytes and hepatopancreas increased significantly at 12 h and 6 h post-infection, respectively. The expression level of HSP90 gene both in hemocytes and hepatopancreas were up-regulated in the first 3 h. The expression patterns of HSP70 and HSP90 genes in hemocytes and hepatopancreas showed temporal and spatial differences after challenged with WSSV and V. anguillarum. The results suggested that HSPs might be involved in immune responses to pathogens challenge in E. carinicauda.

  12. Lipopolysaccharide O-antigen prevents phagocytosis of Vibrio anguillarum by rainbow trout (Oncorhynchus mykiss skin epithelial cells.

    Directory of Open Access Journals (Sweden)

    Kristoffer Lindell

    Full Text Available Colonization of host tissues is a first step taken by many pathogens during the initial stages of infection. Despite the impact of bacterial disease on wild and farmed fish, only a few direct studies have characterized bacterial factors required for colonization of fish tissues. In this study, using live-cell and confocal microscopy, rainbow trout skin epithelial cells, the main structural component of the skin epidermis, were demonstrated to phagocytize bacteria. Mutant analyses showed that the fish pathogen Vibrio anguillarum required the lipopolysaccharide O-antigen to evade phagocytosis and that O-antigen transport required the putative wzm-wzt-wbhA operon, which encodes two ABC polysaccharide transporter proteins and a methyltransferase. Pretreatment of the epithelial cells with mannose prevented phagocytosis of V. anguillarum suggesting that a mannose receptor is involved in the uptake process. In addition, the O-antigen transport mutants could not colonize the skin but they did colonize the intestines of rainbow trout. The O-antigen polysaccharides were also shown to aid resistance to the antimicrobial factors, lysozyme and polymyxin B. In summary, rainbow trout skin epithelial cells play a role in the fish innate immunity by clearing bacteria from the skin epidermis. In defense, V. anguillarum utilizes O-antigen polysaccharides to evade phagocytosis by the epithelial cells allowing it to colonize rapidly fish skin tissues.

  13. Lipopolysaccharide O-Antigen Prevents Phagocytosis of Vibrio anguillarum by Rainbow Trout (Oncorhynchus mykiss) Skin Epithelial Cells

    Science.gov (United States)

    Lindell, Kristoffer; Fahlgren, Anna; Hjerde, Erik; Willassen, Nils-Peder; Fällman, Maria; Milton, Debra L.

    2012-01-01

    Colonization of host tissues is a first step taken by many pathogens during the initial stages of infection. Despite the impact of bacterial disease on wild and farmed fish, only a few direct studies have characterized bacterial factors required for colonization of fish tissues. In this study, using live-cell and confocal microscopy, rainbow trout skin epithelial cells, the main structural component of the skin epidermis, were demonstrated to phagocytize bacteria. Mutant analyses showed that the fish pathogen Vibrio anguillarum required the lipopolysaccharide O-antigen to evade phagocytosis and that O-antigen transport required the putative wzm-wzt-wbhA operon, which encodes two ABC polysaccharide transporter proteins and a methyltransferase. Pretreatment of the epithelial cells with mannose prevented phagocytosis of V. anguillarum suggesting that a mannose receptor is involved in the uptake process. In addition, the O-antigen transport mutants could not colonize the skin but they did colonize the intestines of rainbow trout. The O-antigen polysaccharides were also shown to aid resistance to the antimicrobial factors, lysozyme and polymyxin B. In summary, rainbow trout skin epithelial cells play a role in the fish innate immunity by clearing bacteria from the skin epidermis. In defense, V. anguillarum utilizes O-antigen polysaccharides to evade phagocytosis by the epithelial cells allowing it to colonize rapidly fish skin tissues. PMID:22662189

  14. MHC polymorphism and disease resistance to vibrio anguillarum in 8 families of half-smooth tongue sole (Cynoglossus semilaevis

    Directory of Open Access Journals (Sweden)

    Liu Yan-hong

    2011-09-01

    Full Text Available Abstract Background Genes in the major histocompatibility complex (MHC have a critical role in both the innate and adaptive immune responses because of their involvement in presenting foreign peptides to T cells. However, the nature has remained largely unknown. Results We examined the genetic variation in MHC class IIB in half-smooth tongue sole (Cynoglossus semilaevis after challenge with vibrio anguillarum. Two thousand and four hundred fry from 12 half-smooth tongue sole families were challenged with Vibrio anguillarum. To determine any association between alleles and resistance or susceptibility to V. anguillarum, 160 individuals from four high-resistance (HR, 73.27% mortality families were selected for MHC IIB exon2 gene sequence analysis. The MHC IIB exon2 genes of tongue sole displayed a high level of polymorphism and were discovered at least four loci. Meanwhile, the dN/dS [the ratio of non-synonymous (dN substitutions to synonymous (dS substitutions] in the peptide-binding region (PBR was higher than that in the non-peptide-binding region (non-PBR. Eighty-eight alleles were discovered among 160 individuals, and 13 out of 88 alleles were used to analyze the distribution pattern between the resistant and susceptible families. Certain alleles presented in HR and LR with a different frequency, while other alleles were discovered in only the HR or LR families, not both. Five alleles, Cyse-DBB*6501, Cyse-DBB*4002, Cyse-DBB*6102, Cyse-DBB*5601 and Cyse-DBB*2801, were found to be associated with susceptibility to V. anguillarum with a frequency of 1.25%, 1.25%, 1.25%, 1.25% and 2.5% in the HR families, and 35%, 33.75%, 27.5%, 16.25%, 15% in the LR families (p Cyse-DBB*3301, Cyse-DBB*4701, Cyse-DBB*6801 and Cyse-DBB*5901, were found to be associated with resistance to V. anguillarum, with a frequency of 13.75%, 11.25%, 11.25%, 8.75% in the HR families and 1.25%, 1.25%, 1.25%, 1.25% and 1.25% in the LR families (p Conclusions Elucidation of the

  15. Identification of immunogenic proteins and evaluation of four recombinant proteins as potential vaccine antigens from Vibrio anguillarum in flounder (Paralichthys olivaceus).

    Science.gov (United States)

    Xing, Jing; Xu, Hongsen; Wang, Yang; Tang, Xiaoqian; Sheng, Xiuzhen; Zhan, Wenbin

    2017-05-31

    Vibrio anguillarum is a severe bacterial pathogen that can infect a wide range of fish species. Identification of immunogenic proteins and development of vaccine are essential for disease prevention. In this study, immunogenic proteins were screened and identified from V. anguillarum, and then protective efficacy of the immunogenic proteins was evaluated. Immunogenic proteins in V. anguillarum whole cell were detected by Western blotting (WB) using immunized flounder (Paralichthys olivaceus) serum, and then identified by Mass spectrometry (MS). The recombinant proteins of four identified immunogenic proteins were produced and immunized to fish, and then percentages of surface membrane immunoglobulin-positive (sIg+) cells in peripheral blood lymphocytes (PBL), total antibodies, antibodies against V. anguillarum, antibodies against recombinant proteins and relative percent survival (RPS) were measured, respectively. The results showed that five immunogenic proteins, VAA, Groel, OmpU, PteF and SpK, were identified; their recombinant proteins, rOmpU, rGroel, rSpK and rVAA, could induce the proliferation of sIg+ cells in PBL and production of total antibodies, antibodies against V. anguillarum and antibodies against the recombinant proteins; their protection against V. anguillarum showed 64.86%, 72.97%, 21.62% and 78.38% RPS, respectively. The results revealed that the immunoproteomic technique using fish anti-V. anguillarum serum provided an efficient way to screen the immunogenic protein for vaccine antigen. Moreover, the rVAA, rGroel and rOmpU had potential to be vaccine candidates against V. anguillarum infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Isocitrate dehydrogenase mutation in Vibrio anguillarum results in virulence attenuation and immunoprotection in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Mou, Xiangyu; Spinard, Edward J; Hillman, Shelby L; Nelson, David R

    2017-11-14

    Vibrio anguillarum is an extracellular bacterial pathogen that is a causative agent of vibriosis in finfish and crustaceans with mortality rates ranging from 30% to 100%. Mutations in central metabolism (glycolysis and the TCA cycle) of intracellular pathogens often result in attenuated virulence due to depletion of required metabolic intermediates; however, it was not known whether mutations in central metabolism would affect virulence in an extracellular pathogen such as V. anguillarum. Seven central metabolism mutants were created and characterized with regard to growth in minimal and complex media, expression of virulence genes, and virulence in juvenile rainbow trout (Oncorhynchus mykiss). Only the isocitrate dehydrogenase (icd) mutant was attenuated in virulence against rainbow trout challenged by either intraperitoneal injection or immersion. Further, the icd mutant was shown to be immunoprotective against wild type V. anguillarum infection. There was no significant decrease in the expression of the three hemolysin genes detected by qRT-PCR. Additionally, only the icd mutant exhibited a significantly decreased growth yield in complex media. Growth yield was directly related to the abundance of glutamate. A strain with a restored wild type icd gene was created and shown to restore growth to a wild type cell density in complex media and pathogenicity in rainbow trout. The data strongly suggest that a decreased growth yield, resulting from the inability to synthesize α-ketoglutarate, caused the attenuation despite normal levels of expression of virulence genes. Therefore, the ability of an extracellular pathogen to cause disease is dependent upon the availability of host-supplied nutrients for growth. Additionally, a live vaccine strain could be created from an icd deletion strain.

  17. Zebrafish (Danio rerio) as a model to visualize infection dynamics of Vibrio anguillarum following intraperitoneal injection and bath exposure

    DEFF Research Database (Denmark)

    Schmidt, Jacob Günther; Korbut, Rozalia; Ohtani, Maki

    2017-01-01

    , for which the vaccines are targeted. The zebrafish is by now a well established practical vertebrate model species due in part to its size and ease of maintenance and genetic manipulation. Here we use zebrafish as a model to visualize and compare the development of infection of Vibrio anguillarum......Vaccine development is important for sustainable fish farming and novel vaccines need to be efficacy tested before release to the market. Challenge of fish with the pathogen towards which the vaccine has been produced can be conducted either by external exposure though bathing or cohabitation...... on and in the fish following injection or bathing. Injection of 103 bacteria per fish resulted in approximately 50% mortality by day 4 post-injection. Similar mortality levels were reached in the other group by bathing in 1.25 × 109 bacteria for 1 min. The spreading of bacteria was followed for the first 24 h after...

  18. Defense systems in developing Artemia franciscana nauplii and their modulation by probiotic bacteria offer protection against a Vibrio anguillarum challenge.

    Science.gov (United States)

    Giarma, Eleni; Amanetidou, Eleni; Toufexi, Alexia; Touraki, Maria

    2017-07-01

    The alterations of immune responses of Artemia franciscana nauplii as a function of culture time and after a challenge with the pathogen Vibrio anguillarum were studied. The effect of the administration of the probiotic bacteria Bacillus subtilis, Lactobacillus plantarum and Lactococcus lactis either alone or in combination with the pathogen was evaluated. The activity of the antioxidant enzymes superoxide dismutase (SOD), Glutathione reductase (GRed), Glutathione transferase (GST) and Phenoloxidase (PO) presented a significant increase as a function of culture time, appeared elevated following probiotic administration and were depleted 48 h following the experimental challenge. Lipid peroxidation reached peak levels at 48 h of culture, when nauplii start feeding and returned to lower values at 144 h, remaining however significantly higher than control (P probiotics significantly reduced lipid peroxidation in comparison with the corresponding control, while challenge with the pathogen resulted in its threefold increase. Survival of nauplii remained high throughout culture and was either increased or remained at control levels following the administration of the probiotics. The challenge with the pathogen resulted in a significantly decreased survival of 15.3% for the positive control, while in the probiotic treated series survival values were not significantly different from the negative control (P > 0.05). Following a combined administration of each probiotic and the pathogen the activities of all enzymes tested were significantly lower (P probiotic). Lipid peroxidation was significantly lower in the probiotic treated series in comparison to the positive control (P probiotics B. subtilis, L. plantarum and L. lactis protect Artemia against a V. anguillarum challenge by enhancing its immune responses thus contributing to reduced oxidative damage and increased survival. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Genetic Variability of the Heme Uptake System among Different Strains of the Fish Pathogen Vibrio anguillarum: Identification of a New Heme Receptor

    Science.gov (United States)

    Mouriño, Susana; Rodríguez-Ares, Isabel; Osorio, Carlos R.; Lemos, Manuel L.

    2005-01-01

    The ability to utilize heme compounds as iron sources was investigated in Vibrio anguillarum strains belonging to serotypes O1 to O10. All strains, regardless of their serotype or isolation origin could utilize hemin and hemoglobin as sole iron sources. Similarly, all of the isolates could bind hemin and Congo red, and this binding was mediated by cell envelope proteins. PCR and Southern hybridization were used to assay the occurrence of heme transport genes huvABCD, which have been previously described in serotype O1. Of 23 strains studied, two serotype O3 isolates proved negative for all huvABCD genes, whereas nine strains included in serotypes O2, O3, O4, O6, O7, and O10 tested negative for the outer membrane heme receptor gene huvA. A gene coding for a novel outer membrane heme receptor was cloned and characterized in a V. anguillarum serotype O3 strain lacking huvA. The new heme receptor, named HuvS, showed significant similarity to other outer membrane heme receptors described in Vibrionaceae, but little homology (39%) to HuvA. This heme receptor was present in 9 out of 11 of the V. anguillarum strains that tested negative for HuvA. Furthermore, complementation experiments demonstrated that HuvS could substitute for the HuvA function in Escherichia coli and V. anguillarum mutants. The huvS and huvA sequences alignment, as well as the analysis of their respective upstream and downstream DNA sequences, suggest that horizontal transfer and recombination might be responsible for generating this genetic diversity. PMID:16332832

  20. Effect of multiple infections with white spot syndrome virus and Vibrio anguillarum on Pacific white shrimp Litopenaeus vannamei (L.): mortality and viral replication.

    Science.gov (United States)

    Jang, I K; Qiao, G; Kim, S-K

    2014-10-01

    Multiple infections are commonly found in practical shrimp culture and may cause more serious consequences than infections by one pathogen only. Therefore, this study was conducted to evaluate the effect of multiple infections with white spot syndrome virus (WSSV) and Vibrio anguillarum on Pacific white shrimp Litopenaeus vannamei (L.), mortality, WSSV replication in vivo and host immune response. In the WSSV single-infection group (WSSV load, 2 × 10(2) copies μL(-1)), mean cumulative mortality was 29.2%. In the V. anguillarum single-infection group, cumulative mortality was 12.5% when shrimp were challenged by 10(5) CFU mL(-1) of bacteria. In the co- and super-infection groups, 37.5% and 50% cumulative mortalities, respectively, were observed at a lower bacterial concentration of 10(3) CFU mL(-1), suggesting that shrimp with multiple infections died earlier and more frequently than singly infected shrimp. WSSV load after injection was tracked over time by TaqMan quantitative PCR. WSSV load increased more rapidly in the multiple-infection groups than in the single-infection group. Additionally, mRNA expression of the genes encoding prophenoloxidase 1 and 2, which are closely involved in innate immunity in shrimp, was down-regulated more extensively in multiple-infection groups than in single-infection groups, as indicated by quantitative reverse-transcription PCR. © 2013 John Wiley & Sons Ltd.

  1. HSP70 gene expression in Mytilus galloprovincialis hemocytes is triggered by moderate heat shock and Vibrio anguillarum, but not by V. splendidus or Micrococcus lysodeikticus.

    Science.gov (United States)

    Cellura, Cinzia; Toubiana, Mylène; Parrinello, Nicolo; Roch, Philippe

    2006-01-01

    Complete sequence of HSP70 cDNA from the mussel, Mytilus galloprovincialis was established before quantifying its expression following moderate heat shock or injection of heat-killed bacteria. HSP70 cDNA is comprised of 2378 bp including one ORF of 654 aa, with a predicted 70 bp 5'-UTR and a 343 bp 3'-UTR (GenBank, 18 Jan 05, AY861684). Alignment identity ranged from 89% for Crassostrea ariakensis to 72% for C. virginica. Curiously, HSP70 gene and cDNA sequences from M. galloprovincialis, deposited later (03 and 27 May), show only 73% identity with the present sequence. Meanwhile, characteristic motifs of the HSP70 family were located in conserved positions. Expression of HSP70 gene was quantified on circulating hemocyte mRNA using Q-PCR after RT using random hexaprimers. Housekeeping gene was 28S rRNA. Four stresses were applied: heat shock that consisted of immersing mussels for 90 min at 30 degrees C and returning them to 20 degrees C sea water, one injection of heat-killed Gram-negative bacteria, Vibrio splendidus LGP32, one injection of heat-killed Gram-negative bacteria Vibrio anguillarum, one injection of heat-killed Gram-positive bacteria Micrococcus lysodeikticus. We found no significant modification of 28S rRNA gene expression. Significant increase of 5.2 +/- 0.4 fold the ratio HSP70/28S rRNA was observed 6 h after heat shock and was maximum at 15 h (6.1 +/- 1.1), and still significant after 24 h (1.7 +/- 0.03). Similarly, injecting V. anguillarum resulted in a significant increase of 2.7 +/- 0.1 after 12 h. Expression was maximum after 48 h (5.2 +/- 0.05) and returned to baseline after 72 h. In contrast, injecting V. splendidus or M. lysodeikticus failed to significantly modulate HSP70 gene expression at least during the first 3 days post-injection. Consequently, mussel hemocytes appeared to discriminate between pathogenic and non-pathogenic Vibrios, as well as between Gram-negative and Gram-positive bacteria.

  2. Phaeobacter gallaeciensis Reduces Vibrio anguillarum in Cultures of Microalgae and Rotifers, and Prevents Vibriosis in Cod Larvae

    DEFF Research Database (Denmark)

    D'Alvise, Paul; Lillebø, Siril; Prol García, María Jesús

    2012-01-01

    -antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7) cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio...

  3. Molecular characterization and expression analysis of Lily-type lectin ( SmLTL) in turbot Scophthalmus maximus, and its response to Vibrio anguillarum

    Science.gov (United States)

    Xia, Dandan; Ma, Aijun; Huang, Zhihui; Shang, Xiaomei; Cui, Wenxiao; Yang, Zhi; Qu, Jiangbo

    2018-03-01

    A full-length lily-type lectin ( SmLTL) was identified from turbot ( Scophthalmus maximus) in this study. By searching database for protein identification and function prediction, SmLTL were confirmed. The full-length cDNA of SmLTL is composed of 569 bp and contains a 339 bp ORF that encodes 112 amino acid residues. The SmLTL peptide is characterized by a specific β-prism architecture and contains three mannose binding sites in a three-fold internal repeat between amino acids 30-99; two of the repeats share the classical mannose binding domain (QxDxNxVxY) while the third binding site was similar to other fish-specific binding motifs (TxTxGxRxV). The primary, secondary, and tertiary structures of SmLTL were predicted and analyzed, indicating that the SmLTL protein was hydrophilic, contained 5.36% α-helices, 39.29% extended strands, 16.07% β-folds, and 39.29% random coils, and three β-folds. Quantitative realtime polymerase chain reaction (qPCR) analysis revealed that the SmLTL mRNA was abundantly expressed in skin, gill, and intestine. Low levels of SmLTL expression were observed in other tissues. The expression of SmLTL in gill, skin and intestine increased at mRNA level after stimulation of Vibrio anguillarum, our results suggest that SmLTL serve as the first line of defence against microbial infections and play a pivotal role in the innate mucosal immune system. The current study indicates that SmLTL is a member of the lilytype lectin family and the information reported here will provide an important foundation for future research on the role of this protein.

  4. Elucidation of the Vibrio anguillarum genetic response to the potential fish probiont Pseudomonas fluorescens AH2, using RNA-arbitrarily primed PCR

    DEFF Research Database (Denmark)

    Holmstrøm, Kim; Gram, Lone

    2003-01-01

    or another V. anguillarum siderophore. On the pJM1 plasmid of V anguillarum serotype O1, a pseudogene designated open reading frame E (ORF E) that contains a frameshift mutation was previously identified. The gene homologous to vibE identified in this study, interestingly, also has significant homology...... to ORF E on the amino acid level and does not possess the frameshift mutation. Thus, the chromosomally encoded vibE homologue could fulfil the role of the inactive plasmid-encoded ORF E pseudogene. Addition of Fe3+ to the system eliminated the growth arrest, and the genes homologous to rpoS and vibE were...

  5. Isolation of TDA-producing Phaeobacter strains from sea bass larval rearing units and their probiotic effect against pathogenic Vibrio spp. in Artemia cultures

    DEFF Research Database (Denmark)

    Grotkjær, Torben; Bentzon-Tilia, Mikkel; D'Alvise, Paul

    2016-01-01

    V. harveyi, which is the major bacterial pathogen in crustaceans and Mediterranean sea bass larvae cultures. Concomitantly, they significantly improved survival of V. harveyi-infected brine shrimp. 16S rRNA gene sequence homology identified the antagonists as Phaeobacter sp., and in silico DNA...... Vibrio anguillarum and reduce mortality in V. anguillarum-infected cod and turbot larvae. In this study, it was demonstrated that antagonistic Roseobacter-clade bacteria could be isolated from sea bass larval rearing units. In addition, it was shown that they not only antagonized V. anguillarum but also......-producing Phaeobacter isolated from Mediterranean marine larviculture are promising probiotic bacteria against pathogenic Vibrio in crustacean live-feed cultures for marine fish larvae....

  6. ANTAGONISM AGAINST VIBRIO CHOLERAE BY BACTERIAL DIFFUSIBLE COMPOUND IN THE FECAL MICROBIOTA OF RODENTS

    Directory of Open Access Journals (Sweden)

    Silva Simone Helena da

    1998-01-01

    Full Text Available In an ex vivo agar plate assay, we monitored the appearance of an inhibitory halo against Vibrio cholerae from the feces of Wistar and Fischer rats aged 10 to 42 days. The frequency of Wistar rats showing halo increased from 0% (10 days to a maximum of 80.0% (29 days and then decreased to 53.3% (42 days. A similar pattern was obtained with Fischer rats but with a lower intensity (maximum frequency of 50.0% by day 36. In a separate experiment, when Wistar rats were fed a low-protein diet for 7 days, the inhibitory halo decreased drastically. Three apparently different colony morphologies were isolated from the dominant fecal microbiota: a facultative anaerobe (FAN and two strict anaerobes (SAN. The ex vivo inhibitory test showed a halo around the feces of germfree mice monoassociated with the FAN bacterium or one of the SAN bacterium but not of the germfree ones. After oral challenge of all groups with V. cholerae, a permissive and a drastic barrier effects were observed in mice with FAN and SAN associated bacteria, respectively. The FAN and one SAN bacteria used in the in vivo challenges were identified as Escherichia coli and Streptococcus intermedius, respectively. The potent antagonism developed by the rat intestinal microbiota against V. cholerae seems to be due, in part, to diffusible compounds and this phenomenon depends apparently on age, strain and nutrition of the animals. These preliminary results also suggest that this effect was due to more than one bacterial component at any given moment.

  7. Vibrio damsela as a pathogenic agent causing mortalities in cultured sea bass (Lates calcarifer)

    OpenAIRE

    Renault, Tristan; Haffner, Philippe; Malfondet, C.; Weppe, Maurice

    1994-01-01

    Vibrio anguillarum and Vibrio ordali are species frequently described as fish pathogens. Seven species of Vibrio can also be implicated in disease problems in mariculture (Toranzo 1990). sorne of Vibrios and Barja, In addition, these marine such as V. vulnificus (Tison et al.. 1982) and V. damsela (Love et al., 1981) can also cause illness homoiothermic animals

  8. VanT, a central regulator of quorum sensing signalling in Vibrio anguillarum

    OpenAIRE

    Croxatto, Antony

    2006-01-01

    Many bacteria produce signal molecules that serve in a cell-to-cell communication system termed quorum sensing. This signalling system allows a bacterial population to co-ordinately regulate functions according to their cell number in a defined environment. As bacterial growth progresses towards the stationary phase, signalling molecules accumulate in the growth medium and, above a certain threshold level, regulate the expression of genes involved in diverse functions. Most of the functions m...

  9. AI-2 quorum-sensing inhibitors affect the starvation response and reduce virulence in several Vibrio species, most likely by interfering with LuxPQ.

    Science.gov (United States)

    Brackman, Gilles; Celen, Shari; Baruah, Kartik; Bossier, Peter; Van Calenbergh, Serge; Nelis, Hans J; Coenye, Tom

    2009-12-01

    The increase of disease outbreaks caused by Vibrio species in aquatic organisms as well as in humans, together with the emergence of antibiotic resistance in Vibrio species, has led to a growing interest in alternative disease control measures. Quorum sensing (QS) is a mechanism for regulating microbial gene expression in a cell density-dependent way. While there is good evidence for the involvement of auto-inducer 2 (AI-2)-based interspecies QS in the control of virulence in multiple Vibrio species, only few inhibitors of this system are known. From the screening of a small panel of nucleoside analogues for their ability to disturb AI-2-based QS, an adenosine derivative with a p-methoxyphenylpropionamide moiety at C-3' emerged as a promising hit. Its mechanism of inhibition was elucidated by measuring the effect on bioluminescence in a series of Vibrio harveyi AI-2 QS mutants. Our results indicate that this compound, as well as a truncated analogue lacking the adenine base, block AI-2-based QS without interfering with bacterial growth. The active compounds affected neither the bioluminescence system as such nor the production of AI-2, but most likely interfered with the signal transduction pathway at the level of LuxPQ in V. harveyi. The most active nucleoside analogue (designated LMC-21) was found to reduce the Vibrio species starvation response, to affect biofilm formation in Vibrio anguillarum, Vibrio vulnificus and Vibrio cholerae, to reduce pigment and protease production in V. anguillarum, and to protect gnotobiotic Artemia from V. harveyi-induced mortality.

  10. Presence of Vibrios and Aeromonas strains and total psychrotrophs in hexagonal spotted grouper and Spanish Mackerel Fish

    International Nuclear Information System (INIS)

    Al-Dagal, M.

    2002-01-01

    This work was conducted on different parts of hexagonal-spotted grouper and Spanish mackerel fish from 10 major fishery shops in Riyadh city to assess the presence of vibrios and aeromonas using the API20E and Biolog system. Also, pH and total psychotrophs were assessed as two indexes of quality. Similar data were obtained from both identification systems except for Aeromonas media-like and Vibrio anguillarum which are not included in the API20E database. Aeromonas hydrophila, A. media-like, V. alginolyticus, V.anguillarum, V. damsel and V. fluvialis were recovered from fish samples A. medial-like and V. damsel most predominant. Unexpectedly, V. cholera and V. parahemolyticus were not recovered. The numbers of skin samples of grouper having more than 7 log CFU/gm were much higher than that of mackerel skin samples. Similar psychrotrophic counts were noticed in gut samples of the two fish types, indicating similarly in growth habitat. Most of the grouper fish samples had a pH in the range of >6.40-7.02, whereas 95% of mackerel samples had a pH at 6.40 or below. (author)

  11. Genomic taxonomy of vibrios

    DEFF Research Database (Denmark)

    Thompson, Cristiane C.; Vicente, Ana Carolina P.; Souza, Rangel C.

    2009-01-01

    BACKGROUND: Vibrio taxonomy has been based on a polyphasic approach. In this study, we retrieve useful taxonomic information (i.e. data that can be used to distinguish different taxonomic levels, such as species and genera) from 32 genome sequences of different vibrio species. We use a variety of...

  12. Multipurpose assessment for the quantification of Vibrio spp. and total bacteria in fish and seawater using multiplex real-time polymerase chain reaction

    Science.gov (United States)

    Kim, Ji Yeun; Lee, Jung-Lim

    2014-01-01

    Background This study describes the first multiplex real-time polymerase chain reaction assay developed, as a multipurpose assessment, for the simultaneous quantification of total bacteria and three Vibrio spp. (V. parahaemolyticus, V. vulnificus and V. anguillarum) in fish and seawater. The consumption of raw finfish as sushi or sashimi has been increasing the chance of Vibrio outbreaks in consumers. Freshness and quality of fishery products also depend on the total bacterial populations present. Results The detection sensitivity of the specific targets for the multiplex assay was 1 CFU mL−1 in pure culture and seawater, and 10 CFU g−1 in fish. While total bacterial counts by the multiplex assay were similar to those obtained by cultural methods, the levels of Vibrio detected by the multiplex assay were generally higher than by cultural methods of the same populations. Among the natural samples without Vibrio spp. inoculation, eight out of 10 seawater and three out of 20 fish samples were determined to contain Vibrio spp. Conclusion Our data demonstrate that this multiplex assay could be useful for the rapid detection and quantification of Vibrio spp. and total bacteria as a multipurpose tool for surveillance of fish and water quality as well as diagnostic method. © 2014 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:24752974

  13. Nigribactin, a Novel Siderophore from Vibrio nigripulchritudo, Modulates Staphylococcus aureus Virulence Gene Expression

    DEFF Research Database (Denmark)

    Nielsen, Anita; Månsson, Maria; Wietz, Matthias

    2012-01-01

    Staphylococcus aureus is a serious human pathogen that employs a number of virulence factors as part of its pathogenesis. The purpose of the present study was to explore marine bacteria as a source of compounds that modulate virulence gene expression in S. aureus. During the global marine Galathea...... 3 expedition, a strain collection was established comprising bacteria that express antimicrobial activity against Vibrio anguillarum and/or Staphylococcus aureus. Within this collection we searched colony material, culture supernatants, and cell extracts for virulence modulating activity showing......, enterobactin, failed to influence S. aureus virulence gene expression. This study shows that marine microorganisms produce compounds with potential use in therapeutic strategies targeting virulence rather than viability of human pathogens....

  14. Bacterial Associations: Antagonism to Symbiosis

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.

    mutualism through commensalisms and competition, to antagonism, determined ultimately by balancing the cost of the association against the benefits received (Pianka, 1994). A continuum can be envisioned that spans a dynamic bridge from antagonism... when two organisms form a relationship, which provides an advantage for both the partners at least temporarily. In commensalisms only one partner derives benefit and the other does not. Symbiosis The word, ?symbiosis? is derived from the Greek word...

  15. Genomic taxonomy of vibrios

    Directory of Open Access Journals (Sweden)

    Iida Tetsuya

    2009-10-01

    Full Text Available Abstract Background Vibrio taxonomy has been based on a polyphasic approach. In this study, we retrieve useful taxonomic information (i.e. data that can be used to distinguish different taxonomic levels, such as species and genera from 32 genome sequences of different vibrio species. We use a variety of tools to explore the taxonomic relationship between the sequenced genomes, including Multilocus Sequence Analysis (MLSA, supertrees, Average Amino Acid Identity (AAI, genomic signatures, and Genome BLAST atlases. Our aim is to analyse the usefulness of these tools for species identification in vibrios. Results We have generated four new genome sequences of three Vibrio species, i.e., V. alginolyticus 40B, V. harveyi-like 1DA3, and V. mimicus strains VM573 and VM603, and present a broad analyses of these genomes along with other sequenced Vibrio species. The genome atlas and pangenome plots provide a tantalizing image of the genomic differences that occur between closely related sister species, e.g. V. cholerae and V. mimicus. The vibrio pangenome contains around 26504 genes. The V. cholerae core genome and pangenome consist of 1520 and 6923 genes, respectively. Pangenomes might allow different strains of V. cholerae to occupy different niches. MLSA and supertree analyses resulted in a similar phylogenetic picture, with a clear distinction of four groups (Vibrio core group, V. cholerae-V. mimicus, Aliivibrio spp., and Photobacterium spp.. A Vibrio species is defined as a group of strains that share > 95% DNA identity in MLSA and supertree analysis, > 96% AAI, ≤ 10 genome signature dissimilarity, and > 61% proteome identity. Strains of the same species and species of the same genus will form monophyletic groups on the basis of MLSA and supertree. Conclusion The combination of different analytical and bioinformatics tools will enable the most accurate species identification through genomic computational analysis. This endeavour will culminate in

  16. Cinnamaldehyde and cinnamaldehyde derivatives reduce virulence in Vibrio spp. by decreasing the DNA-binding activity of the quorum sensing response regulator LuxR

    Directory of Open Access Journals (Sweden)

    Van Calenbergh Serge

    2008-09-01

    Full Text Available Abstract Background To date, only few compounds targeting the AI-2 based quorum sensing (QS system are known. In the present study, we screened cinnamaldehyde and substituted cinnamaldehydes for their ability to interfere with AI-2 based QS. The mechanism of QS inhibition was elucidated by measuring the effect on bioluminescence in several Vibrio harveyi mutants. We also studied in vitro the ability of these compounds to interfere with biofilm formation, stress response and virulence of Vibrio spp. The compounds were also evaluated in an in vivo assay measuring the reduction of Vibrio harveyi virulence towards Artemia shrimp. Results Our results indicate that cinnamaldehyde and several substituted derivatives interfere with AI-2 based QS without inhibiting bacterial growth. The active compounds neither interfered with the bioluminescence system as such, nor with the production of AI-2. Study of the effect in various mutants suggested that the target protein is LuxR. Mobility shift assays revealed a decreased DNA-binding ability of LuxR. The compounds were further shown to (i inhibit biofilm formation in several Vibrio spp., (ii result in a reduced ability to survive starvation and antibiotic treatment, (iii reduce pigment and protease production in Vibrio anguillarum and (iv protect gnotobiotic Artemia shrimp against virulent Vibrio harveyi BB120. Conclusion Cinnamaldehyde and cinnamaldehyde derivatives interfere with AI-2 based QS in various Vibrio spp. by decreasing the DNA-binding ability of LuxR. The use of these compounds resulted in several marked phenotypic changes, including reduced virulence and increased susceptibility to stress. Since inhibitors of AI-2 based quorum sensing are rare, and considering the role of AI-2 in several processes these compounds may be useful leads towards antipathogenic drugs.

  17. Cinnamaldehyde and cinnamaldehyde derivatives reduce virulence in Vibrio spp. by decreasing the DNA-binding activity of the quorum sensing response regulator LuxR

    Science.gov (United States)

    Brackman, Gilles; Defoirdt, Tom; Miyamoto, Carol; Bossier, Peter; Van Calenbergh, Serge; Nelis, Hans; Coenye, Tom

    2008-01-01

    Background To date, only few compounds targeting the AI-2 based quorum sensing (QS) system are known. In the present study, we screened cinnamaldehyde and substituted cinnamaldehydes for their ability to interfere with AI-2 based QS. The mechanism of QS inhibition was elucidated by measuring the effect on bioluminescence in several Vibrio harveyi mutants. We also studied in vitro the ability of these compounds to interfere with biofilm formation, stress response and virulence of Vibrio spp. The compounds were also evaluated in an in vivo assay measuring the reduction of Vibrio harveyi virulence towards Artemia shrimp. Results Our results indicate that cinnamaldehyde and several substituted derivatives interfere with AI-2 based QS without inhibiting bacterial growth. The active compounds neither interfered with the bioluminescence system as such, nor with the production of AI-2. Study of the effect in various mutants suggested that the target protein is LuxR. Mobility shift assays revealed a decreased DNA-binding ability of LuxR. The compounds were further shown to (i) inhibit biofilm formation in several Vibrio spp., (ii) result in a reduced ability to survive starvation and antibiotic treatment, (iii) reduce pigment and protease production in Vibrio anguillarum and (iv) protect gnotobiotic Artemia shrimp against virulent Vibrio harveyi BB120. Conclusion Cinnamaldehyde and cinnamaldehyde derivatives interfere with AI-2 based QS in various Vibrio spp. by decreasing the DNA-binding ability of LuxR. The use of these compounds resulted in several marked phenotypic changes, including reduced virulence and increased susceptibility to stress. Since inhibitors of AI-2 based quorum sensing are rare, and considering the role of AI-2 in several processes these compounds may be useful leads towards antipathogenic drugs. PMID:18793453

  18. Evidence for the role of horizontal transfer in generating pVT1, a large mosaic conjugative plasmid from the clam pathogen, Vibrio tapetis.

    Directory of Open Access Journals (Sweden)

    Gaël Erauso

    Full Text Available The marine bacterium Vibrio tapetis is the causative agent of the brown ring disease, which affects the clam Ruditapes philippinarum and causes heavy economic losses in North of Europe and in Eastern Asia. Further characterization of V. tapetis isolates showed that all the investigated strains harbored at least one large plasmid. We determined the sequence of the 82,266 bp plasmid pVT1 from the CECT4600(T reference strain and analyzed its genetic content. pVT1 is a mosaic plasmid closely related to several conjugative plasmids isolated from Vibrio vulnificus strains and was shown to be itself conjugative in Vibrios. In addition, it contains DNA regions that have similarity with several other plasmids from marine bacteria (Vibrio sp., Shewanella sp., Listonella anguillarum and Photobacterium profundum. pVT1 contains a number of mobile elements, including twelve Insertion Sequences or inactivated IS genes and an RS1 phage element related to the CTXphi phage of V. cholerae. The genetic organization of pVT1 underscores an important role of horizontal gene transfer through conjugative plasmid shuffling and transposition events in the acquisition of new genetic resources and in generating the pVT1 modular organization. In addition, pVT1 presents a copy number of 9, relatively high for a conjugative plasmid, and appears to belong to a new type of replicon, which may be specific to Vibrionaceae and Shewanelleacae.

  19. Phaeobacter inhibens as probiotic bacteria in non-axenic Artemia and algae cultures

    OpenAIRE

    Grotkjær, T.; Bentzon-Tilia, M.; D'Alvise, P.; Dierckens, K.; Bossier, P.; Gram, L.

    2016-01-01

    The growing aquaculture industry is in need for non-antibiotic based disease control strategies to reduce risk of bacteria developing and spreading antibiotic resistance. We have previously, in axenic model systems of live larval feed, demonstrated that bacteria from the Roseobacter clade can antagonize fish pathogens such as Vibrio anguillarum and Vibrio harveyi and that they can reduce larval mortality in challenge trials. However, in the aquaculture production, a natural microbiota is pres...

  20. Phaeobacter inhibens as probiotic bacteria in non-axenic Artemia and algae cultures

    DEFF Research Database (Denmark)

    Grotkjær, Torben; Bentzon-Tilia, Mikkel; D'Alvise, Paul

    2016-01-01

    antagonize fish pathogens such as Vibrio anguillarum and Vibrio harveyi and that they can reduce larval mortality in challenge trials. However, in the aquaculture production, a natural microbiota is present at all stages and may affect the efficacy of the probiotic bacteria. The purpose of the present study......, irrespective of the background microbiota. We therefore conclude that P. inhibens are indeed promising as probiotic bacteria in marine larvi-culture where it in natural live feed can suppress fish larval pathogens....

  1. Vibrios and Aeromonas.

    Science.gov (United States)

    Holmberg, S D

    1988-09-01

    There are many similarities in the Vibrionaceae that cause human illness in the United States (see Table 1). Vibrios are characteristically indigenous to marine, estuarine, and brackish environments. They are distributed mainly in Gulf of Mexico coastal water, and these organisms "bloom" when the water is warm. Outbreaks of disease in humans frequently occur in summer, coinciding with multiplication of vibrios in warm water. Sporadic cases and small outbreaks of cholera continue to occur in persons living on or near the Gulf of Mexico, but infection in most persons is unrecognized. In fact, more serious and frequent illnesses result from V. vulnificus wound infections and from gastroenteritis caused by vibrios other than V. cholerae 01. Underlying hepatic or neoplastic disease (especially leukemia) apparently increases the likelihood and severity of illnesses caused by V. vulnificus and Aeromonas. Some Vibrionaceae produce clinical illness by means of enterotoxins identical or similar to cholera toxin. For many others, hemolysins, cytotoxins, and other exotoxins are necessary to produce disease; the importance of these virulence factors often is not known or the importance of these virulence factors often is not known or is of doubtful significance. Also, purported pathogenicity as demonstrated by animal models, such as fluid accumulation in ligated ileal loops, is quite nonspecific and needs to be interpreted cautiously. For Plesiomonas, a mode of pathogenesis has not been discovered. Eating raw shellfish (frequently raw oysters) has been linked epidemiologically to enteric infections with most of these bacteria; foreign travel and exposure to seawater are other frequently observed epidemiologic associations with infection. Foreign travel, particularly to the Yucatan Peninsula of Mexico, has been strongly associated with the acquisition of non-01 V. cholerae and Plesiomonas organisms. Most Vibrionaceae in the United States are susceptible in vitro--and illnesses

  2. Microbial Ecophysiology of Vibrio ruber

    Directory of Open Access Journals (Sweden)

    Tjaša Danevčič

    2014-01-01

    Full Text Available Bacteria use different adaptation strategies to survive environmental perturbations. In this minireview, adaptation strategies of new red-pigmented Vibrio ruber isolated from coastal environments to different environmental stresses (i.e. salinity, viscosity, UV light, mitomycin C, nutrient availability and temperature are reviewed. To cope with environmental stresses Vibrio ruber uses several different adaptive strategies. For example, lipid composition as well as phase behaviour are strongly dependent on salt concentration. Vibrio ruber membrane has no hydroxy fatty acids, but exceptionally high lysolipid content compared to other related Vibrio species. Inorganic nutrient uptake by bacteria is selective, depends on environmental conditions and varies several fold with environmental perturbations. Protein composition, carbon flow through the central metabolic pathways, energy generation as well as secondary metabolite production adapt readily to stress conditions. The activity of glucose-6-phosphate dehydrogenase proved to be a good indicator of Vibrio ruber stress. Cells are able to modulate their local viscosity in response to variations of environmental viscosity. The bacterium harbours several viral genetic elements in its genome, which could be induced by mitomycin C. Environmental conditions during growth of bacteria have a significant effect on lysate carbon turnover. Secondary metabolite prodigiosin confers protection against UV in the environment, which adds to the known repertoire of prodigiosin ecophysiological functions. In conclusion, Vibrio ruber in its short acquaintance with the scientific community (less than ten years has proven to be an immensely valuable model system for ecophysiological studies of bacteria.

  3. Predatory bacteria as natural modulators of Vibrio parahaemolyticus and Vibrio vulnificus in seawater and oysters

    Science.gov (United States)

    This study shows that naturally occurring Vibrio predatory bacteria (VPB) exert a major role in controlling pathogenic vibrios in seawater and shellfish. The growth and persistence of Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) were assessed in natural seawater and in the Eastern oyster...

  4. Antagonism of acetylcholine by adrenaline antagonists

    Science.gov (United States)

    Benfey, B. G.; Grillo, S. A.

    1963-01-01

    Phenoxybenzamine antagonized the inhibitory action of acetylcholine on the guinea-pig isolated atrium. The antagonism was slow in onset, very slowly reversible, and could be overcome by increased concentrations of acetylcholine. In contrast, atropine inhibited the action of acetylcholine quickly, and the effect disappeared soon after withdrawal. The pA10 of phenoxybenzamine (2 hr of contact) was 6.8, and that of atropine (30 min of contact) was 8.4. In the presence of atropine phenoxybenzamine did not exert a slowly reversible antagonism, and the dose-ratio of acetylcholine returned to normal soon after withdrawal of both drugs. Phenoxybenzamine also antagonized acetylcholine in the guinea-pig isolated ileum, but with higher concentrations acetylcholine did not overcome the antagonism. The pA10 (60 min of contact) was 6.6. The pA10 of chlorpromazine in the atrium (2 hr of contact) and ileum (60 min of contact) was 5.9. Phentolamine, 2-diethylaminomethylbenzo-1,4-dioxan hydrochloride (883 F), and yohimbine antagonized acetylcholine in the atrium and ileum but required higher concentrations than chlorpromazine. PMID:13967429

  5. Vibrio Parahaemolyticus: The Threat of Another Vibrio Acquiring Pandemic Potential

    Digital Repository Service at National Institute of Oceanography (India)

    Ramamurthy, T.; Nair, G.B.

    investigations of Vibrio parahaemolyticus in oysters following outbreaks in Washington, Texas, and New York. (1997 and 1998). Appl. Envrion. Microbiol. 66, 4649- 4654. DePaola, A., Ulaszek, J., Kaysner, C. A., Tenge, B. J., Nordstrom, J. L., Wells, J., Puhr, N...-710. Andrews, L. S., DeBlanc, S., Veal, C. D., Park, D. L., 2003. Response of Vibrio parahaemolyticus O3:K6 to a hot water/ cold shock pasteurization process. Food Addit. Contam. 20, 331-334. Bag, P. K., Nandi, S., Bhadra, R. K., Ramamurthy, T., Bhattacharya, S...

  6. Isolation and characterization of pathogenic Listonella anguillarum of diseased half-smooth tongue sole ( Cynoglossus semilaevis Günther)

    Science.gov (United States)

    Tang, Xiaoqian; Zhou, Li; Zhan, Wenbin

    2008-08-01

    Studies were conducted to determine the cause of the acute mortality of half-smooth tongue sole Cynoglossus semilaevis Günther juveniles in a fish farm in Jimo, Shandong Province, China, in June 2006. Gross signs of the diseased tongue sole included several petechiae and ecchymoses on the body and fin necrosis and hemorrhagic lesion at the base of the fin. Bacteria were isolated from kidney, liver and hemorrhagic lesions of the diseased tongue sole. Among14 strains, SJ060621 was proved to be highly virulent to juvenile tongue sole with LD50 value of antibiotics tested, SJ060621 was sensitive to gentamicin and nitrofurantoin. It was identified as Listonella anguillarum with conventional plate and tube tests in combination with API 20E analysis. 16S rRNA gene and partial HSP60 gene sequenceing analysis revealed that the strain was highly homologous with L. anguillarum. Examination of the infected musculature by electron microscopy indicated numerous bacteria and lots of macrophages containing phagocytosed bacteria. Histopathological investigations revealed severe necrotic degenerative changes in the infected organs. Indirect immunofluorescence assay (IFA) was employed to detect the location of occurrence of bacteria, and bacteria were found in aggregations in the inflammatory areas in musculature.

  7. The ecology of Vibrio vulnificus, Vibrio cholerae, and Vibrio parahaemolyticus in North Carolina estuaries.

    Science.gov (United States)

    Blackwell, Karen Dyer; Oliver, James D

    2008-04-01

    While numerous studies have characterized the distribution and/or ecology of various pathogenic Vibrio spp., here we have simultaneously examined several estuarine sites for Vibrio vulnificus, V. cholerae, and V. parahaemolyticus. For a one year period, waters and sediment were monitored for the presence of these three pathogens at six different sites on the east coast of North Carolina in the United States. All three pathogens, identified using colony hybridization and PCR methods, occurred in these estuarine environments, although V. cholerae occurred only infrequently and at very low levels. Seventeen chemical, physical, and biological parameters were investigated, including salinity, water temperature, turbidity, dissolved oxygen, levels of various inorganic nutrients and dissolved organic carbon, as well as total vibrios, total coliforms, and E. coli. We found each of the Vibrio spp. in water and sediment to correlate to several of these environmental measurements, with water temperature and total Vibrio levels correlating highly (P<0.0001) with occurrence of the three pathogens. Thus, these two parameters may represent simple assays for characterizing the potential public health hazard of estuarine waters.

  8. Sensitivity of the vibrios to ultraviolet-radiation

    International Nuclear Information System (INIS)

    Banerjee, S.K.; Chatterjee, S.N.

    1977-01-01

    The ultraviolet-inactivation kinetics of a number of strains of Vibrio cholerae (classical), Vibrio cholerae (el tor), NAG vibrios and Vibrio parahaemolyticus were investigated. Statistical analyses revealed significant differences between any two of the four types of vibrio in respect of their sensitivity to U.V. (author)

  9. Prevalence of Vibrio vulnificus and Vibrio parahaemolyticus in the Maryland Coastal Bays

    Science.gov (United States)

    De Pascuale, V. O.

    2016-02-01

    The bacterial family of Vibrionaceae is indigenous in the marine estuarine environments such as the Maryland Coastal Bays. Vibrio vulnificus and Vibrio parahaemolyticus are both pathogenic bacteria. Understanding the distribution of Vibrio species is crucial because of the health concerns associated with the bacteria. The aim of this study was to evaluate the overall abundance of bacteria with a focus on Vibrio species in the Maryland Coastal Bays. Seawater samples were collected from 10 different sites that differ with regard to water quality. The total bacteria count (TBC) was determined by two methods: Total plate count and Epifluorescence microscopy. The most-probable-number (MPN) methodology was used to estimate the population of Vibrio parahaemolyticus and Vibrio vulnificus. In addition to the bacteriological analysis, the environmental parameters of temperature and salinity were measured using YSI 6600 multiparameter meter. The average total bacteria count was 2.21 log CFU ml-1. Vibrio vulnificus comprised 5% of the total bacteria count while Vibrio parahaemolyticus comprised only 2% of the total bacteria count. Vibrio vulnificus ranged from 0.30 to 2.48 log MPN ml-1 at the sites tested. Lower Vibrio parahaemolyticus count was observed at the sites with a range of 0.30 to 1.97 log MPN ml-1. There was no significant correlation between the environmental parameters and the Vibrio spp. Since both Vibrio vulnificus and Vibrio parahaemolyticus peak in the summer, there is a potential for a risk of wound infections and gastrointestinal illness based on this data.

  10. POTENSI BEBERAPA ISOLAT PROBIOTIK SEBAGAI ANTIBAKTERI TERHADAP PERTUMBUHAN Vibrio spp.

    OpenAIRE

    HASBIAH

    2015-01-01

    The research about potential of some probiotic isolates as an antibacterial on the growth of Vibrio spp had been done. This research aimed to know the antibacterial potency from some isolates probiotic on the growth of Vibrio spp. This research to tested the inhibition on the three species of Vibrio that are Vibrio harveyi, Vibrio prahaemolyticus, and Vibrio cholerae using agar diffusion method. Probiotic isolates come from lactic acid bacteria group that provide beneficial effects on health ...

  11. White shrimp (Litopenaeus vannamei) recombinant lysozyme has antibacterial activity against Gram negative bacteria: Vibrio alginolyticus, Vibrio parahemolyticus and Vibrio cholerae.

    Science.gov (United States)

    de-la-Re-Vega, Enrique; García-Galaz, Alfonso; Díaz-Cinco, Martha E; Sotelo-Mundo, Rogerio R

    2006-03-01

    C-type lysozyme has been described as an antibacterial component of the shrimp innate defence system. We determined quantitatively the antibacterial activity of white shrimp (Litopenaeus vannamei) recombinant lysozyme against three Gram negative bacteria: Vibrio alginolyticus, Vibrio parahemolyticus and Vibrio cholerae, using a turbidimetric assay with live bacteria and differential bacterial viable count after interaction with the protein. In conclusion, the antibacterial activity of recombinant shrimp lysozyme against Vibrio sp. is at least equal to the values against the Gram positive M. luteus and more active against the shrimp pathogens V. alginolyticus and V. parahemolyticus.

  12. The Antagonism Mechanism Of Trichoderma spp. Towards Fusarium solani Mold

    OpenAIRE

    Utami Sri Hastuti; Indriana Rahmawati

    2016-01-01

    The antagonism ability of seven Trichoderma isolates towards F.solani have been observed and tested by dual culture technique. The antagonism mechanism observed by microscopic observation with light microscope and Scanning Electron Microscopy (SEM). The research result showed seven species of Trichoderma molds have different antagonism ability towards F.solani each other. The antagonism mechanism observed by light microscope and Scanning Electron Microscopy were mycoparasitism, antibiosis, an...

  13. The Antagonism Mechanism Of Trichoderma spp. Towards Fusarium solani Mold

    Directory of Open Access Journals (Sweden)

    Utami Sri Hastuti

    2016-09-01

    Full Text Available The antagonism ability of seven Trichoderma isolates towards F.solani have been observed and tested by dual culture technique. The antagonism mechanism observed by microscopic observation with light microscope and Scanning Electron Microscopy (SEM. The research result showed seven species of Trichoderma molds have different antagonism ability towards F.solani each other. The antagonism mechanism observed by light microscope and Scanning Electron Microscopy were mycoparasitism, antibiosis, and competition.

  14. Vibrio chromosome-specific families

    DEFF Research Database (Denmark)

    Lukjancenko, Oksana; Ussery, David

    2014-01-01

    We have compared chromosome-specific genes in a set of 18 finished Vibrio genomes, and, in addition, also calculated the pan- and core-genomes from a data set of more than 250 draft Vibrio genome sequences. These genomes come from 9 known species and 2 unknown species. Within the finished...... chromosomes, we find a core set of 1269 encoded protein families for chromosome 1, and a core of 252 encoded protein families for chromosome 2. Many of these core proteins are also found in the draft genomes (although which chromosome they are located on is unknown.) Of the chromosome specific core protein...... families, 1169 and 153 are uniquely found in chromosomes 1 and 2, respectively. Gene ontology (GO) terms for each of the protein families were determined, and the different sets for each chromosome were compared. A total of 363 different "Molecular Function" GO categories were found for chromosome 1...

  15. Crayfish: a newly recognized vehicle for vibrio infections.

    Science.gov (United States)

    Bean, N H; Maloney, E K; Potter, M E; Korazemo, P; Ray, B; Taylor, J P; Seigler, S; Snowden, J

    1998-10-01

    We conducted a 1-year case-control study of sporadic vibrio infections to identify risk factors related to consumption of seafood products in two coastal areas of Louisiana and Texas. Twenty-six persons with sporadic vibrio infections and 77 matched controls were enrolled. Multivariate analysis revealed that crayfish (P Vibrio parahemolyticus infection (OR 9.24, P vibrio infection.

  16. Reconceptualizing synergism and antagonism among multiple stressors

    OpenAIRE

    Piggott, Jeremy J; Townsend, Colin R; Matthaei, Christoph D

    2015-01-01

    The potential for complex synergistic or antagonistic interactions between multiple stressors presents one of the largest uncertainties when predicting ecological change but, despite common use of the terms in the scientific literature, a consensus on their operational definition is still lacking. The identification of synergism or antagonism is generally straightforward when stressors operate in the same direction, but if individual stressor effects oppose each other, the definition of syner...

  17. Triclosan antagonizes fluconazole activity against Candida albicans.

    LENUS (Irish Health Repository)

    Higgins, J

    2012-01-01

    Triclosan is a broad-spectrum antimicrobial compound commonly used in oral hygiene products. Investigation of its activity against Candida albicans showed that triclosan was fungicidal at concentrations of 16 mg\\/L. However, at subinhibitory concentrations (0.5-2 mg\\/L), triclosan antagonized the activity of fluconazole. Although triclosan induced CDR1 expression in C. albicans, antagonism was still observed in cdr1Δ and cdr2Δ strains. Triclosan did not affect fluconazole uptake or alter total membrane sterol content, but did induce the expression of FAS1 and FAS2, indicating that its mode of action may involve inhibition of fatty acid synthesis, as it does in prokaryotes. However, FAS2 mutants did not exhibit increased susceptibility to triclosan, and overexpression of both FAS1 and FAS2 alleles did not alter triclosan susceptibility. Unexpectedly, the antagonistic effect was specific for C. albicans under hypha-inducing conditions and was absent in the non-filamentous efg1Δ strain. This antagonism may be due to the membranotropic activity of triclosan and the unique composition of hyphal membranes.

  18. Genes encoding the Vibrio harveyi haemolysin (VHH)/thermolabile haemolysin (TLH) are widespread in Vibrios%VHH/TLH溶血素基因在海洋弧菌中分布的研究

    Institute of Scientific and Technical Information of China (English)

    王淑娴; 张晓华; 钟英斌; 孙铂光; 陈吉祥

    2007-01-01

    deduced amino acid sequences are up to 85.6%), is a putative virulence factor to marine cultured fish. A VHH probe, which is specific to V. harveyi vhhA haemolysin gene, was used to screen EcoR Ⅰ digests of total DNA from 57 vibrio strains, including 26 vibrio type strains, 20 V. harveyi isolates and 11 V. parahaemolyticus isolates. As a result, 1 strong hybridisation band was detected in 13 type strains, including 2 of Vibrio alginolyticus , 2 of V. harveyi , and 1 strain each of Grimontia hollisae , V. campbellii , V. cincinnatiensis , V. fischeri , V. mimicus , V.natriegens, V. parahaemolyticus, V. proteolyticus and V. logei. Also, 1 weak band was detected in 6 type strains, including V.anguillarum, V. aestuarianus, Photobacterium damselae subsp. damselae, V. fluvialis, V. furnissii and V. vulnificus. There was not any hybridization signal in other type strains. Also, vhh/tlh was present in all isolates of V. harveyi and V. parahaemolyticus. Moreover, 3 isolates of V. harveyi, i.e. VIB 645, VIB 648 and SF1, had duplicated vhh genes. The data indicates that vhh/tlh is widespread in vibrios,especially in V. harveyi related species and V. fischeri related species. To support this conclusion, the vhh/tlh homologue genes in V.anguillarum VIB 72, V. campbellii VIB 285, V. natriegens VIB 299 and V. harveyi VIB 647 were cloned and sequenced, and the deduced amino acid sequences showed high degree of identities to VHH (67% ~ 99% ) and TLH haemolysin (69% ~ 91% ). This study will help us to identify the role of vhh/tlh haemolysin gene in the pathogenicity of vibrios.

  19. Vibrio parahemolyticus bacteremia: case report.

    Science.gov (United States)

    Ng, T C; Chiang, P C; Wu, T L; Leu, H S

    1999-09-01

    Vibrio parahemolyticus (V. parahemolyticus) is a halophilic gram-negative bacillus that lives in the ocean. It is the leading cause of infectious diarrhea in Taiwan and sometimes produces soft tissue infections, but it is rarely a cause of bacteremia. There have been only 11 cases reported in the literature. Most of the cases involved a history of ingestion of seafood or exposure to seawater. In addition, those patients were all immunosuppressed, especially with leukemia and cirrhosis. We report a 60-year-old male patient with chronic hepatitis C and adrenal insufficiency. He developed V. parahemolyticus bacteremia following ingestion of seafood one week prior to admission. His condition was complicated with neck and right lower leg soft tissue infection, as well as multiple organ failure. The patient survived after intravenous ceftazidime, oral doxycycline, and surgical debridement. To our knowledge, this is the 12th reported cases on Medline, and the second bacteremic case in Taiwan. After reviewing the literature, we suggest that all patients with immunosuppressed conditions or adrenal insufficiency should eat foods that are well cooked and avoid raw seafood. Moreover, when patients who are at risk to develop fever, diarrhea, and soft tissue infection after ingestion of seafood, V. parahemolyticus infection should be suspected. All culture specimens should be inoculated on Vibrios selective media.

  20. Natural Protection of Wood with Antagonism Fungi

    Directory of Open Access Journals (Sweden)

    Alba ZAREMSKI

    2011-03-01

    Full Text Available Biological environments contain a certain number of microbial populations which, within a givenecological niche, display various relations ranging from symbiosis to parasitism. Researchers have beeninterested in these types of relations for around fifty years, especially in one very particular type ofrelationship: the antagonism exerted between individuals of the same microbial population.Today, the role played by biological agents, bringing into play inhibitive or destructive antibioticsubstances, reveals a certain potential for their use in controlling microorganisms associated with suchdegradation processes.The work undertaken by HydroQuébec and CIRAD involved two types of experiment: 1 in Petri dishes toassess and characterize the antagonistic capacity of Trichoderma against white rot and brown rot fungi; 2on pieces taken from untreated poles in order to study confrontation between the basidiomycete and theantagonistic strain in wood.This study investigated the antagonism of three ascomycetes of the genus Trichoderma against two whiterot basidiomycetes, Pycnoporus sanguineus and Coriolus versicolor, and two brown rot basidiomycetes,Antrodia sp. and Coniophora puteana, through direct confrontation in Petri dishes and in the wood ofHydroQuébec poles.The results obtained seemed to complete each other coherently. They revealed that the Trichodermagroup of fungi was not aggressive to wood and the results obtained after direct confrontation in Petri disheswere confirmed in wood.By directly exposing the different basidiomycetes and antagonists to each other in Petri dishes, two bytwo, we effectively revealed an antagonism effect for a large majority of the pairs. However, there wassubstantial variability in reactions from one pair to the next.

  1. Reconceptualizing synergism and antagonism among multiple stressors.

    Science.gov (United States)

    Piggott, Jeremy J; Townsend, Colin R; Matthaei, Christoph D

    2015-04-01

    The potential for complex synergistic or antagonistic interactions between multiple stressors presents one of the largest uncertainties when predicting ecological change but, despite common use of the terms in the scientific literature, a consensus on their operational definition is still lacking. The identification of synergism or antagonism is generally straightforward when stressors operate in the same direction, but if individual stressor effects oppose each other, the definition of synergism is paradoxical because what is synergistic to one stressor's effect direction is antagonistic to the others. In their highly cited meta-analysis, Crain et al. (Ecology Letters, 11, 2008: 1304) assumed in situations with opposing individual effects that synergy only occurs when the cumulative effect is more negative than the additive sum of the opposing individual effects. We argue against this and propose a new systematic classification based on an additive effects model that combines the magnitude and response direction of the cumulative effect and the interaction effect. A new class of "mitigating synergism" is identified, where cumulative effects are reversed and enhanced. We applied our directional classification to the dataset compiled by Crain et al. (Ecology Letters, 11, 2008: 1304) to determine the prevalence of synergistic, antagonistic, and additive interactions. Compared to their original analysis, we report differences in the representation of interaction classes by interaction type and we document examples of mitigating synergism, highlighting the importance of incorporating individual stressor effect directions in the determination of synergisms and antagonisms. This is particularly pertinent given a general bias in ecology toward investigating and reporting adverse multiple stressor effects (double negative). We emphasize the need for reconsideration by the ecological community of the interpretation of synergism and antagonism in situations where

  2. Identification and mechanism of ABA receptor antagonism

    KAUST Repository

    Melcher, Karsten; Xu, Yong; Ng, Ley-Moy; Zhou, X. Edward; Soon, Fen-Fen; Chinnusamy, Viswanathan; Suino-Powell, Kelly M.; Kovach, Amanda; Tham, Fook S.; Cutler, Sean R.; Li, Jun; Yong, Eu-Leong; Zhu, Jian-Kang; Xu, H. Eric

    2010-01-01

    The phytohormone abscisic acid (ABA) functions through a family of fourteen PYR/PYL receptors, which were identified by resistance to pyrabactin, a synthetic inhibitor of seed germination. ABA activates these receptors to inhibit type 2C protein phosphatases, such as ABI1, yet it remains unclear whether these receptors can be antagonized. Here we demonstrate that pyrabactin is an agonist of PYR1 and PYL1 but is unexpectedly an antagonist of PYL2. Crystal structures of the PYL2-pyrabactin and PYL1-pyrabactin-ABI1 complexes reveal the mechanism responsible for receptor-selective activation and inhibition, which enables us to design mutations that convert PYL1 to a pyrabactin-inhibited receptor and PYL2 to a pyrabactin-activated receptor and to identify new pyrabactin-based ABA receptor agonists. Together, our results establish a new concept of ABA receptor antagonism, illustrate its underlying mechanisms and provide a rational framework for discovering novel ABA receptor ligands. © 2010 Nature America, Inc. All rights reserved.

  3. Identification and mechanism of ABA receptor antagonism

    KAUST Repository

    Melcher, Karsten

    2010-08-22

    The phytohormone abscisic acid (ABA) functions through a family of fourteen PYR/PYL receptors, which were identified by resistance to pyrabactin, a synthetic inhibitor of seed germination. ABA activates these receptors to inhibit type 2C protein phosphatases, such as ABI1, yet it remains unclear whether these receptors can be antagonized. Here we demonstrate that pyrabactin is an agonist of PYR1 and PYL1 but is unexpectedly an antagonist of PYL2. Crystal structures of the PYL2-pyrabactin and PYL1-pyrabactin-ABI1 complexes reveal the mechanism responsible for receptor-selective activation and inhibition, which enables us to design mutations that convert PYL1 to a pyrabactin-inhibited receptor and PYL2 to a pyrabactin-activated receptor and to identify new pyrabactin-based ABA receptor agonists. Together, our results establish a new concept of ABA receptor antagonism, illustrate its underlying mechanisms and provide a rational framework for discovering novel ABA receptor ligands. © 2010 Nature America, Inc. All rights reserved.

  4. Resistance to Antimicrobial Peptides in Vibrios

    Directory of Open Access Journals (Sweden)

    Delphine Destoumieux-Garzón

    2014-10-01

    Full Text Available Vibrios are associated with a broad diversity of hosts that produce antimicrobial peptides (AMPs as part of their defense against microbial infections. In particular, vibrios colonize epithelia, which function as protective barriers and express AMPs as a first line of chemical defense against pathogens. Recent studies have shown they can also colonize phagocytes, key components of the animal immune system. Phagocytes infiltrate infected tissues and use AMPs to kill the phagocytosed microorganisms intracellularly, or deliver their antimicrobial content extracellularly to circumvent tissue infection. We review here the mechanisms by which vibrios have evolved the capacity to evade or resist the potent antimicrobial defenses of the immune cells or tissues they colonize. Among their strategies to resist killing by AMPs, primarily vibrios use membrane remodeling mechanisms. In particular, some highly resistant strains substitute hexaacylated Lipid A with a diglycine residue to reduce their negative surface charge, thereby lowering their electrostatic interactions with cationic AMPs. As a response to envelope stress, which can be induced by membrane-active agents including AMPs, vibrios also release outer membrane vesicles to create a protective membranous shield that traps extracellular AMPs and prevents interaction of the peptides with their own membranes. Finally, once AMPs have breached the bacterial membrane barriers, vibrios use RND efflux pumps, similar to those of other species, to transport AMPs out of their cytoplasmic space.

  5. Hatchery mortalities of larval oysters caused by Vibrio tubiashii and Vibrio coralliilyticus

    Science.gov (United States)

    Hatchery production of bivalve shellfish has been hampered by the occasional presence of opportunistic pathogens, particularly Vibrio coralliilyticus and Vibrio tubiashii. The present study reports the results of several avenues of research to better define these pathogens and the roles they play i...

  6. Rapid proliferation of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae during freshwater flash floods in French Mediterranean coastal lagoons.

    Science.gov (United States)

    Esteves, Kevin; Hervio-Heath, Dominique; Mosser, Thomas; Rodier, Claire; Tournoud, Marie-George; Jumas-Bilak, Estelle; Colwell, Rita R; Monfort, Patrick

    2015-11-01

    Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae of the non-O1/non-O139 serotype are present in coastal lagoons of southern France. In these Mediterranean regions, the rivers have long low-flow periods followed by short-duration or flash floods during and after heavy intense rainstorms, particularly at the end of the summer and in autumn. These floods bring large volumes of freshwater into the lagoons, reducing their salinity. Water temperatures recorded during sampling (15 to 24°C) were favorable for the presence and multiplication of vibrios. In autumn 2011, before heavy rainfalls and flash floods, salinities ranged from 31.4 to 36.1‰ and concentrations of V. parahaemolyticus, V. vulnificus, and V. cholerae varied from 0 to 1.5 × 10(3) most probable number (MPN)/liter, 0.7 to 2.1 × 10(3) MPN/liter, and 0 to 93 MPN/liter, respectively. Following heavy rainstorms that generated severe flash flooding and heavy discharge of freshwater, salinity decreased, reaching 2.2 to 16.4‰ within 15 days, depending on the site, with a concomitant increase in Vibrio concentration to ca. 10(4) MPN/liter. The highest concentrations were reached with salinities between 10 and 20‰ for V. parahaemolyticus, 10 and 15‰ for V. vulnificus, and 5 and 12‰ for V. cholerae. Thus, an abrupt decrease in salinity caused by heavy rainfall and major flooding favored growth of human-pathogenic Vibrio spp. and their proliferation in the Languedocian lagoons. Based on these results, it is recommended that temperature and salinity monitoring be done to predict the presence of these Vibrio spp. in shellfish-harvesting areas of the lagoons. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Forced Normalization: Antagonism Between Epilepsy and Psychosis.

    Science.gov (United States)

    Kawakami, Yasuhiko; Itoh, Yasuhiko

    2017-05-01

    The antagonism between epilepsy and psychosis has been discussed for a long time. Landolt coined the term "forced normalization" in the 1950s to describe psychotic episodes associated with the remission of seizures and disappearance of epileptiform activity on electroencephalograms in individuals with epilepsy. Since then, neurologists and psychiatrists have been intrigued by this phenomenon. However, although collaborative clinical studies and basic experimental researches have been performed, the mechanism of forced normalization remains unknown. In this review article, we present a historical overview of the concept of forced normalization, and discuss potential pathogenic mechanisms and clinical diagnosis. We also discuss the role of dopamine, which appears to be a key factor in the mechanism of forced normalization. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Agonism and antagonism at the insulin receptor

    DEFF Research Database (Denmark)

    Knudsen, Louise; Hansen, Bo Falck; Jensen, Pia

    2012-01-01

    Insulin can trigger metabolic as well as mitogenic effects, the latter being pharmaceutically undesirable. An understanding of the structure/function relationships between insulin receptor (IR) binding and mitogenic/metabolic signalling would greatly facilitate the preclinical development of new...... insulin analogues. The occurrence of ligand agonism and antagonism is well described for G protein-coupled receptors (GPCRs) and other receptors but in general, with the exception of antibodies, not for receptor tyrosine kinases (RTKs). In the case of the IR, no natural ligand or insulin analogue has been...... shown to exhibit antagonistic properties, with the exception of a crosslinked insulin dimer (B29-B'29). However, synthetic monomeric or dimeric peptides targeting sites 1 or 2 of the IR were shown to be either agonists or antagonists. We found here that the S961 peptide, previously described to be an IR...

  9. Suspension of oysters reduces the populations of Vibrio parahaemolyticus and Vibrio vulnificus.

    Science.gov (United States)

    Cole, K M; Supan, J; Ramirez, A; Johnson, C N

    2015-09-01

    Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) are associated with the consumption of raw oysters and cause illnesses ranging from simple gastroenteritis to life-threatening septicaemia. These halophilic bacteria are frequently found in marine and estuarine systems, accumulating within the tissues of a number of aquatic organisms and passing on to humans after consumption, through contaminated water, or via open wounds. As benthic organisms capable of filtering 40 gallons of water per hour, sediment is an important source of potentially pathogenic vibrios in oysters destined for raw consumption. This research used off-bottom oyster culture to reduce vibrio concentrations in oysters. Colony hybridization was used to enumerate Vp and Vv in bottom and suspended oysters. Vv and Vp concentrations were generally lower in oysters suspended off-bottom, and suspension decreased vibrio loads in oysters by an average of 13%. Suspension of oysters reduced vibrio concentrations. This study found that oyster suspension significantly reduced some populations of potentially pathogenic vibrios. These results indicate that oyster suspension could be a viable approach for preharvest treatment to reduce illness in consumers of raw oysters. © 2015 The Society for Applied Microbiology.

  10. Effects of Global Warming on Vibrio Ecology.

    Science.gov (United States)

    Vezzulli, Luigi; Pezzati, Elisabetta; Brettar, Ingrid; Höfle, Manfred; Pruzzo, Carla

    2015-06-01

    Vibrio-related infections are increasing worldwide both in humans and aquatic animals. Rise in global sea surface temperature (SST), which is approximately 1 °C higher now than 140 years ago and is one of the primary physical impacts of global warming, has been linked to such increases. In this chapter, major known effects of increasing SST on the biology and ecology of vibrios are described. They include the effects on bacterial growth rate, both in the field and in laboratory, culturability, expression of pathogenicity traits, and interactions with aquatic organisms and abiotic surfaces. Special emphasis is given to the effect of ocean warming on Vibrio interactions with zooplankters, which represent one of the most important aquatic reservoirs for these bacteria. The reported findings highlight the biocomplexity of the interactions between vibrios and their natural environment in a climate change scenario, posing the need for interdisciplinary studies to properly understand the connection between ocean warming and persistence and spread of vibrios in sea waters and the epidemiology of the diseases they cause.

  11. Bacteriophage interactions with marine pathogenic Vibrios

    DEFF Research Database (Denmark)

    Kalatzis, Panagiotis

    development and spreading of antibiotic resistant bacteria in the environment. Bacteriophage therapy, constitutes a potent alternative not only for treatment but also for prevention of vibriosis in aquaculture and the current thesis addresses the potential and challenges of using phages to control Vibrio...... pathogens. The combinatory administration of virulent bacteriophages φSt2 and φGrn1, isolated against Vibrio alginolyticus significantly reduced the Vibrio load in cultures of Artemia salina live prey, decreasing subsequently the risk of a vibriosis outbreak in the marine hatchery. During infection...... therapy applications. Lytic phage vB_VspP_pVa5 that has been isolated against the rapidly emerging pathogen V. splendidus is also a promising candidate for phage therapy application according to its gene content and in vitro performance against its host. The genetic features of vB_VspP_pVa5 provide also...

  12. Bacteriophages in the control of pathogenic vibrios

    DEFF Research Database (Denmark)

    Plaza, Nicolás; Castillo Bermúdez, Daniel Elías; Perez-Reytor, Diliana

    2018-01-01

    constitute a continuing threat for aquaculture. Moreover, the continuous use of antibiotics has been accompanied by an emergence of antibiotic resistance in Vibrio species, implying a necessity for efficient treatments. One promising alternative that emerges is the use of lytic bacteriophages; however......, there are some drawbacks that should be overcome to make phage therapy a widely accepted method. In this work, we discuss about the major pathogenic Vibrio species and the progress, benefits and disadvantages that have been detected during the experimental use of bacteriophages to their control....

  13. Vibrio ecology - Identifying Environmental Determinants Favorable for the Presence and Transmission of Pathogenic Vibrios

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In a tri-coastal collaborative study, the population densities of vibrios are being determined in the Mississippi Sound, Puget Sound, Chesapeake Bay, and Timbalier...

  14. Vibrio population structure - Genetic and population structure analysis of clinical and environmental Vibrio parahaemolyticus strains

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Vibrio parahaemolyticus (Vp) is a marine bacterium capable of causing severe gastroenteritis in humans, usually through the consumption of raw shellfish. Before...

  15. Aktivitas Antibakteri Ekstrak Buah Adas (Foeniculum vulgare, Mill) pada Vibrio harveyi dan Vibrio alginolyticus

    OpenAIRE

    Budianto, Budianto; Prajitno, Arief; Yuniarti, Ating

    2017-01-01

    Evaluation of natural products as a safe and effective antimicrobial agent is a scientific strategy to treat the drugresistant pathogens.Fennel(FoeniculumvulgareMill) is an herbal plant that has an active in gredient which is one of its benefit sasan antibacterial material. In thisstudy,water extract of fennel fruit determined the antibacterial activity against Vibrio harveyi and Vibrio alginolyticus using the minimum Inhibitory  Concentration Test (MIC) and paper disk diffusion method....

  16. Luminescence, virulence and quorum sensing signal production by pathogenic Vibrio campbellii and Vibrio harveyi isolates.

    Science.gov (United States)

    Defoirdt, T; Verstraete, W; Bossier, P

    2008-05-01

    To study the relationship between luminescence, autoinducer production and virulence of pathogenic vibrios. Luminescence, quorum sensing signal production and virulence towards brine shrimp nauplii of 13 Vibrio campbellii and Vibrio harveyi strains were studied. Although only two of the tested strains were brightly luminescent, all of them were shown to produce the three different types of quorum sensing signals known to be produced by Vibrio harveyi. Cell-free culture fluids of all strains significantly induced bioluminescence in the cholerae autoinducer 1, autoinducer 2 and harveyi autoinducer 1 reporter strains JAF375, JMH597 and JMH612, respectively. There was no relation between luminescence and signal production and virulence towards brine shrimp. There is a large difference between different strains of Vibrio campbellii and Vibrio harveyi with respect to bioluminescence. However, this is not reflected in signal production and virulence towards gnotobiotic brine shrimp. Moreover, there seems to be no relation between quorum sensing signal production and virulence towards brine shrimp. The results presented here indicate that strains that are most brightly luminescent are not necessarily the most virulent ones and that the lower virulence of some of the strains is not due to a lack of autoinducer production.

  17. Organic metabolites produced by Vibrio parahaemolyticus strain ...

    African Journals Online (AJOL)

    Identification and action of several antibacterial metabolites produced by a fish pathogen Vibrio parahaemolyticus strain An3 from marine ecosystem of Goa has been demonstrated. Antibacterial activity of the crude cell extract of the test bacterium has been evaluated against indicator pathogenic bacterial strains such as ...

  18. Comparison of classifications of aptamers against Vibrio ...

    African Journals Online (AJOL)

    As a novel method to detect the pathogen Vibrio alginolyticus, 45 aptamers were previously selected and tested. In order to better understand the properties of these aptamers, it was essential to classify these aptamers based on appropriate criteria. The primary structure of 45 aptamers against V. alginolyticus was analyzed ...

  19. AKTIVITAS ANTIBAKTERI EKSTRAK BUAH ADAS (Foeniculum vulgare, Mill PADA Vibrio harveyi DAN Vibrio alginolyticus Antibacterial Activity of Fennel (Foeniculum vulgare Mill Extract on Vibrio alginolyticus and Vibrio harveyi

    Directory of Open Access Journals (Sweden)

    Budianto Budianto

    2015-10-01

    Pada penelitian ini menggunakan ekstrak air dari buah adas untuk mengetahui aktivitas antibakteri terhadap Vibrio harveyi dan Vibrio alginolyticus dengan menggunakan metode uji Minimum Inhibitory Concentration (MIC dan difusi cakram kertas. Hasil yang diperoleh pada uji MIC, konsentrasi terkecil untuk menghambat pertumbuhan adalah 0,060 g/ml, untuk kedua spesies bakteri. Variasi perlakuan pada uji cakram kertas yaitu konsentrasi A (0,065 g/ml, B (0,070 g/ml, C (0,075 g/ml, D (0,080 g/ml, E (0,085 g/ml, F (0,090 g/ml dan kontrol (0,000 g/ml, hasil yang diperoleh adalah konsentrasi 0,090 g/ml memiliki diameter zona hambat tertinggi sebesar 11,17 ± 0,5 mm (V. harveyi dan 12,53 ± 1,14 mm (V. alginolyticus, sehingga dapat disimpulkan bahwa buah adas (F. vulgare Mill memiliki peranan ekologi yang sangat penting sebagai bahan pengobatan alternatif dalam pengendalian penyebaran penyakit Vibriosis yang disebabkan oleh V. harveyi dan V. alginolyticus. Kata kunci: Foeniculum vulgare Mill, Vibrio harveyi, Vibrio alginolyticus, uji MIC dan difusi cakram kertas

  20. Isolation of lytic bacteriophage against Vibrio harveyi.

    Science.gov (United States)

    Crothers-Stomps, C; Høj, L; Bourne, D G; Hall, M R; Owens, L

    2010-05-01

    The isolation of lytic bacteriophage of Vibrio harveyi with potential for phage therapy of bacterial pathogens of phyllosoma larvae from the tropical rock lobster Panulirus ornatus. Water samples from discharge channels and grow-out ponds of a prawn farm in northeastern Australia were enriched for 24 h in a broth containing four V. harveyi strains. The bacteriophage-enriched filtrates were spotted onto bacterial lawns demonstrating that the bacteriophage host range for the samples included strains of V. harveyi, Vibrio campbellii, Vibrio rotiferianus, Vibrio parahaemolyticus and Vibrio proteolyticus. Bacteriophage were isolated from eight enriched samples through triple plaque purification. The host range of purified phage included V. harveyi, V. campbellii, V. rotiferianus and V. parahaemolyticus. Transmission electron microscope examination revealed that six purified phage belonged to the family Siphoviridae, whilst two belonged to the family Myoviridae. The Myoviridae appeared to induce bacteriocin production in a limited number of host bacterial strains, suggesting that they were lysogenic rather than lytic. A purified Siphoviridae phage could delay the entry of a broth culture of V. harveyi strain 12 into exponential growth, but could not prevent the overall growth of the bacterial strain. Bacteriophage with lytic activity against V. harveyi were isolated from prawn farm samples. Purified phage of the family Siphoviridae had a clear lytic ability and no apparent transducing properties, indicating they are appropriate for phage therapy. Phage resistance is potentially a major constraint to the use of phage therapy in aquaculture as bacteria are not completely eliminated. Phage therapy is emerging as a potential antibacterial agent that can be used to control pathogenic bacteria in aquaculture systems. The development of phage therapy for aquaculture requires initial isolation and determination of the bacteriophage host range, with subsequent creation of

  1. AN INVESTIGATION ON PATHOGENIC VIBRIOS DISTRIBUTION IN DOMESTIC WASTEWATER

    OpenAIRE

    A. Almasi

    2005-01-01

    Municipal wastewater is one of the most important pollution sources for water supply resources. Identification and enumeration of pathogenic agents particularly pathogenic Vibrios are beneficial for controlling and prevention planning of the infectious diseases. This research was carried out to identify the distribution of the recognized pathogenic Vibrios with emphasizing on identification of Vibrio cholera in the wastewater of Kermanshah city western Iran in 2002. The method of study was cr...

  2. Highly diverse recombining populations of Vibrio cholerae and Vibrio parahaemolyticus in French Mediterranean coastal lagoons

    Directory of Open Access Journals (Sweden)

    Kevin eEsteves

    2015-07-01

    Full Text Available Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species can induce infections in humans. Therefore understanding the structure and dynamics of non-pandemic environmental populations in temperate regions, such as Mediterranean coastal systems, is important if we are to evaluate the risks of infection to humans.Environmental isolates of V. cholerae (n=109 and V. parahaemolyticus (n=89 sampled at different dates, stations and water salinities were investigated for virulence genes and by a multilocus sequence-based analysis (MLSA. V. cholerae isolates were all ctxA negative and only one isolate of V. parahaemolyticus displayed trh2 gene. Most Sequence Types (ST corresponded to unique ST isolated at one date or one station. Frequent recombination events were detected among different pathogenic species, V. parahaemolyticus, V. cholerae, Vibrio mimicus and Vibrio metoecus. Recombination had a major impact on the diversification of lineages. The genetic diversity assessed by the number of ST/strain was higher in low salinity conditions for V. parahaemolyticus and V. cholerae whereas the frequency of recombination events in V. cholerae was lower in low salinity. Mediterranean coastal lagoon systems housed V. cholerae and V. parahaemolyticus with genetic diversities equivalent to the worldwide diversity described so far. The presence of STs found in human infections as well as the frequency of recombination events in environmental vibrios populations could predict a potential epidemiological risk.

  3. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3930 Vibrio... from cultured isolates derived from clinical specimens. The identification aids in the diagnosis of...

  4. Vibrio spp. ISOLATED FROM SHRIMPS AND WATER FROM A MARINE FARM IN PERNAMBUCO, BRAZIL Víbrios en el agua y en las gambas del mar (Litopenaeus vannamei, Boone, 1931 cultivado en Pernambuco Vibrio spp. ISOLADOS DE CAMARÃO E ÁGUA DE CULTIVO DE FAZENDA MARINHA EM PERNAMBUCO

    Directory of Open Access Journals (Sweden)

    Carlos André Bezerra Alves

    2009-12-01

    Full Text Available

    Water and shrimp samples were collected monthly, during all cultivation phases, in three located farms at Pernambuco coast, on winter and summer, for Vibrio spp. quantification and identification. The counting’s were correlated, through mathematical models (P<0.05, with the variables season, water biochemical parameters, wet mount, histopathology exam, toxins presence and handling techniques used. Just the variable cultivation time interfered at total counting of Vibrio spp. in all samples were obtained countings that varied 0.1x 10 to 6.2 x 103 UFC/mL in water, of 7.0 x 10 to 8.2 x 105 UFC/g in powder-larva, of 1.1 x 10 to 1.1 x 105 UFC/mL in hemolymph and of 2.5 x 102 to 1.1 x 106UFC/g in hepatopancreas. The species V. mediterranei (1%, V. mimicus (1.25%, V. fischeri (4.25%, V. cincinnatiensis (4.25%, V. metschnikovii (4.25%, V. proteolyticus (5.5%, V. harveyi (5.5%, V. hollisae (5.5%, V. carchariae (7%, V. vulnificus (8.5%, V. damsela (8.5%, V. parahaemolyticus (13%, V. fluvialis (15%, V. anguillarum (16.5% were identified. It is concluded that the Vibrionaceae load increases proportionally with cultivation time, due to the organic matter increment, what can turn the susceptible animals to the infection for vibrios.

    KEY WORD: Vibrionaceae, Vibrio spp., shrimp and pond water.
    El agua y muestras de la gamba eran la publicación mensual reunido, durante todas las fases del cultivo, en tres granjas localizadas a la costa de Pernambuco, en invierno y verano, para la cuantificación e identificación el de Vibrio spp.. El contando fueron puestos en correlación, a través de los modelos matemáticos (P <0,05, con la estación de las variables, agua que los parámetros bioquímicos, montaña mojada, examen del histopatologia, presencia de las toxinas y técnicas manejando usaron. Simplemente el tiempo del cultivo inconstante interfirió a total que

  5. Effects of Intertidal Harvest Practices on Levels of Vibrio parahaemolyticus and Vibrio vulnificus Bacteria in Oysters.

    Science.gov (United States)

    Jones, J L; Kinsey, T P; Johnson, L W; Porso, R; Friedman, B; Curtis, M; Wesighan, P; Schuster, R; Bowers, J C

    2016-08-01

    Vibrio parahaemolyticus and Vibrio vulnificus can grow rapidly in shellfish subjected to ambient air conditions, such as during intertidal exposure. In this study, levels of total and pathogenic (tdh(+) and/or trh(+)) V. parahaemolyticus and total V. vulnificus were determined in oysters collected from two study locations where intertidal harvest practices are common. Samples were collected directly off intertidal flats, after exposure (ambient air [Washington State] or refrigerated [New Jersey]), and after reimmersion by natural tidal cycles. Samples were processed using a most-probable-number (MPN) real-time PCR method for total and pathogenic V. parahaemolyticus or V. vulnificus In Washington State, the mean levels of V. parahaemolyticus increased 1.38 log MPN/g following intertidal exposure and dropped 1.41 log MPN/g after reimmersion for 1 day, but the levels were dependent upon the container type utilized. Pathogenic V. parahaemolyticus levels followed a similar trend. However, V. vulnificus levels increased 0.10 log MPN/g during intertidal exposure in Washington but decreased by >1 log MPN/g after reimmersion. In New Jersey, initial levels of all vibrios studied were not significantly altered during the refrigerated sorting and containerizing process. However, there was an increase in levels after the first day of reimmersion by 0.79, 0.72, 0.92, and 0.71 log MPN/g for total, tdh(+) and trh(+) V. parahaemolyticus, and V. vulnificus, respectively. The levels of all targets decreased to those similar to background after a second day of reimmersion. These data indicate that the intertidal harvest and handling practices for oysters that were studied in Washington and New Jersey do not increase the risk of illness from V. parahaemolyticus or V. vulnificus Vibrio parahaemolyticus and Vibrio vulnificus are the leading causes of seafood-associated infectious morbidity and mortality in the United States. Vibrio spp. can grow rapidly in shellfish subjected to ambient

  6. Carriage of vibrio species by shrimps harvested from the coastal ...

    African Journals Online (AJOL)

    Objectives: To determine the prevalence of Vibrio spp in unprocessed shrimps and their susceptibility to antibiotics. Design: A prospective study of Vibrio spp associated with shrimps harvested from the coastal waters of South West Cameroon. Setting: A laboratory based study at the Department of Life Sciences, University ...

  7. Rhubarb Antagonizes Matrix Metalloproteinase-9-induced Vascular Endothelial Permeability

    Directory of Open Access Journals (Sweden)

    Yun-Liang Cui

    2016-01-01

    Conclusions: The rhubarb mixture of emodin, 3,8-dihydroxy-1-methyl-anthraquinone-2-carboxylic acid, 1-O-caffeoyl-2-(4-hydroxyl-O-cinnamoyl-β-D-glucose, daucosterol linoleate, and rhein, at a low concentration, antagonized the MMP9-induced HUVEC monolayer permeability by promoting HUVEC proliferation and reducing extracellular VE-cadherin concentrations.

  8. Analysis of Determinants in Filovirus Glycoproteins Required for Tetherin Antagonism

    Directory of Open Access Journals (Sweden)

    Kerstin Gnirß

    2014-04-01

    Full Text Available The host cell protein tetherin can restrict the release of enveloped viruses from infected cells. The HIV-1 protein Vpu counteracts tetherin by removing it from the site of viral budding, the plasma membrane, and this process depends on specific interactions between the transmembrane domains of Vpu and tetherin. In contrast, the glycoproteins (GPs of two filoviruses, Ebola and Marburg virus, antagonize tetherin without reducing surface expression, and the domains in GP required for tetherin counteraction are unknown. Here, we show that filovirus GPs depend on the presence of their authentic transmembrane domains for virus-cell fusion and tetherin antagonism. However, conserved residues within the transmembrane domain were dispensable for membrane fusion and tetherin counteraction. Moreover, the insertion of the transmembrane domain into a heterologous viral GP, Lassa virus GPC, was not sufficient to confer tetherin antagonism to the recipient. Finally, mutation of conserved residues within the fusion peptide of Ebola virus GP inhibited virus-cell fusion but did not ablate tetherin counteraction, indicating that the fusion peptide and the ability of GP to drive host cell entry are not required for tetherin counteraction. These results suggest that the transmembrane domains of filoviral GPs contribute to tetherin antagonism but are not the sole determinants.

  9. Antagonism in the carbon footprint between beef and dairy ...

    African Journals Online (AJOL)

    The higher increase in production (milk) of intensive dairy cows, compared to the increase in production (calf weight) of intensive beef cows, explains the antagonism in the carbon footprint between different beef and dairy production systems. Unfortunately, carbon sequestration estimates have been neglected and thus the ...

  10. Exploitative and hierarchical antagonism in a cooperative bacterium.

    Directory of Open Access Journals (Sweden)

    Francesca Fiegna

    2005-11-01

    Full Text Available Social organisms that cooperate with some members of their own species, such as close relatives, may fail to cooperate with other genotypes of the same species. Such noncooperation may take the form of outright antagonism or social exploitation. Myxococcus xanthus is a highly social prokaryote that cooperatively develops into spore-bearing, multicellular fruiting bodies in response to starvation. Here we have characterized the nature of social interactions among nine developmentally proficient strains of M. xanthus isolated from spatially distant locations. Strains were competed against one another in all possible pairwise combinations during starvation-induced development. In most pairings, at least one competitor exhibited strong antagonism toward its partner and a majority of mixes showed bidirectional antagonism that decreased total spore production, even to the point of driving whole populations to extinction. Differential response to mixing was the primary determinant of competitive superiority rather than the sporulation efficiencies of unmixed populations. In some competitive pairings, the dominant partner sporulated more efficiently in mixed populations than in clonal isolation. This finding represents a novel form of exploitation in bacteria carried out by socially competent genotypes and is the first documentation of social exploitation among natural bacterial isolates. Patterns of antagonistic superiority among these strains form a highly linear dominance hierarchy. At least some competition pairs construct chimeric, rather than segregated, fruiting bodies. The cooperative prokaryote M. xanthus has diverged into a large number of distinct social types that cooperate with clone-mates but exhibit intense antagonism toward distinct social types of the same species. Most lengthy migration events in nature may thus result in strong antagonism between migratory and resident populations, and this antagonism may have large effects on local

  11. Vibrio Iron Transport: Evolutionary Adaptation to Life in Multiple Environments

    Science.gov (United States)

    Mey, Alexandra R.; Wyckoff, Elizabeth E.

    2015-01-01

    SUMMARY Iron is an essential element for Vibrio spp., but the acquisition of iron is complicated by its tendency to form insoluble ferric complexes in nature and its association with high-affinity iron-binding proteins in the host. Vibrios occupy a variety of different niches, and each of these niches presents particular challenges for acquiring sufficient iron. Vibrio species have evolved a wide array of iron transport systems that allow the bacteria to compete for this essential element in each of its habitats. These systems include the secretion and uptake of high-affinity iron-binding compounds (siderophores) as well as transport systems for iron bound to host complexes. Transporters for ferric and ferrous iron not complexed to siderophores are also common to Vibrio species. Some of the genes encoding these systems show evidence of horizontal transmission, and the ability to acquire and incorporate additional iron transport systems may have allowed Vibrio species to more rapidly adapt to new environmental niches. While too little iron prevents growth of the bacteria, too much can be lethal. The appropriate balance is maintained in vibrios through complex regulatory networks involving transcriptional repressors and activators and small RNAs (sRNAs) that act posttranscriptionally. Examination of the number and variety of iron transport systems found in Vibrio spp. offers insights into how this group of bacteria has adapted to such a wide range of habitats. PMID:26658001

  12. Vibrio elicits targeted transcriptional responses from copepod hosts.

    Science.gov (United States)

    Almada, Amalia A; Tarrant, Ann M

    2016-06-01

    Copepods are abundant crustaceans that harbor diverse bacterial communities, yet the nature of their interactions with microbiota are poorly understood. Here, we report that Vibrio elicits targeted transcriptional responses in the estuarine copepod Eurytemora affinis We pre-treated E. affinis with an antibiotic cocktail and exposed them to either a zooplankton specialist (Vibrio sp. F10 9ZB36) or a free-living species (Vibrio ordalii 12B09) for 24 h. We then identified via RNA-Seq a total of 78 genes that were differentially expressed following Vibrio exposure, including homologs of C-type lectins, chitin-binding proteins and saposins. The response differed between the two Vibrio treatments, with the greatest changes elicited upon inoculation with V. sp. F10 We suggest that these differentially regulated genes play important roles in cuticle integrity, the innate immune response, and general stress response, and that their expression may enable E. affinis to recognize and regulate symbiotic vibrios. We further report that V. sp. F10 culturability is specifically altered upon colonization of E. affinis These findings suggest that rather than acting as passive environmental vectors, copepods discriminately interact with vibrios, which may ultimately impact the abundance and activity of copepod-associated bacteria. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. QStatin, a Selective Inhibitor of Quorum Sensing in Vibrio Species

    Directory of Open Access Journals (Sweden)

    Byoung Sik Kim

    2018-01-01

    Full Text Available Pathogenic Vibrio species cause diseases in diverse marine animals reared in aquaculture. Since their pathogenesis, persistence, and survival in marine environments are regulated by quorum sensing (QS, QS interference has attracted attention as a means to control these bacteria in aquatic settings. A few QS inhibitors of Vibrio species have been reported, but detailed molecular mechanisms are lacking. Here, we identified a novel, potent, and selective Vibrio QS inhibitor, named QStatin [1-(5-bromothiophene-2-sulfonyl-1H-pyrazole], which affects Vibrio harveyi LuxR homologues, the well-conserved master transcriptional regulators for QS in Vibrio species. Crystallographic and biochemical analyses showed that QStatin binds tightly to a putative ligand-binding pocket in SmcR, the LuxR homologue in V. vulnificus, and changes the flexibility of the protein, thereby altering its transcription regulatory activity. Transcriptome analysis revealed that QStatin results in SmcR dysfunction, affecting the expression of SmcR regulon required for virulence, motility/chemotaxis, and biofilm dynamics. Notably, QStatin attenuated representative QS-regulated phenotypes in various Vibrio species, including virulence against the brine shrimp (Artemia franciscana. Together, these results provide molecular insights into the mechanism of action of an effective, sustainable QS inhibitor that is less susceptible to resistance than other antimicrobial agents and useful in controlling the virulence of Vibrio species in aquacultures.

  14. Effects of ambient exposure, refrigeration, and icing on Vibrio vulnificus and Vibrio parahaemolyticus abundances in oysters.

    Science.gov (United States)

    Jones, J L; Lydon, K A; Kinsey, T P; Friedman, B; Curtis, M; Schuster, R; Bowers, J C

    2017-07-17

    Vibrio vulnificus (Vv) and V. parahaemolyticus (Vp) illnesses are typically acquired through the consumption of raw molluscan shellfish, particularly oysters. As Vibrio spp. are naturally-occurring bacteria, one means of mitigation of illness is achieved by limiting post-harvest growth. In this study, effects of ambient air storage, refrigeration, and icing of oysters on Vibrio spp. abundances were examined at two sites in Alabama (AL) [Dog River (DR) and Cedar Point (CP)] and one site in Delaware Bay, New Jersey (NJ). As the United States shellfish program recommendations include testing for total these organisms and gene targets, Vv and total (tlh) and pathogenic (tdh+ and trh+) Vp were enumerated from samples using MPN-real-time-PCR approaches. Mean Vv and Vp abundances in oysters from AL-DR were lowest in immediately iced samples (2.3 and -0.1 log MPN/g, respectively) and highest in the 5h ambient then refrigerated samples (3.4 and 0.5 log MPN/g, respectively). Similarly, in AL-CP Vv and Vp mean levels in oysters were lowest in immediately iced samples (3.6 and 1.2 log MPN/g, respectively) and highest in 5h ambient then refrigerated samples (5.1 and 3.2 log MPN/g, respectively). Mean levels of pathogenic Vp from AL sites were frequently below the limit of detection (oysters were highest in samples which were held for 7h in the shade (5.3 and 4.8 log MPN/g, respectively). Mean pathogenic Vp levels in oysters at initial harvest were also highest in oysters 7h in the shade (2.1 and 2.2 log MPN/g for tdh+ and trh+ Vp). Regardless of sampling location, Vibrio spp. levels were generally significantly (poysters exposed to 5h of air storage compared to the initially harvested samples. In addition, the data demonstrated that the use of layered ice resulted in lower Vibrio spp. levels in oysters, compared to those that were refrigerated post-harvest. These results suggest vibriosis risk can be mitigated by shorter storage times and more rapid cooling of oysters

  15. [Mexican phenotype and genotype Vibrio cholerae 01].

    Science.gov (United States)

    Giono, S; Gutiérrez Cogno, L; Rodríguez Angeles, G; del Rio Zolezzi, A; Valdespino González, J L; Sepúlveda Amor, J

    1995-01-01

    This paper presents the phenotypical and genotypical characterization of 26922 Vibrio cholerae 01 strains isolated in Mexico from 1991 to 1993. All strains isolated were El Tor biovar. Strains were sensitive to antibiotics excluding furazolidone, streptomycin and sulfisoxasole to which we found resistance in 97% and we are using this characteristic as epidemiological markers. We detected a marked change in frequency of Inaba serotype from 1991, when it was dominant, with 99.5%, until 1992 when Ogawa serotype turned to be dominant with 95% of isolates. All Vibrio cholerae 01 strains, except one Ogawa strain, were to igenic, and V. choleraeno 01 were not toxigenic by ELISA, PCR and cell culture tests. Dominant ribotype was 5, but we found some strains with 6a pattern and two with ribotype 12. We are searching for ribotype 2 among hemolytic strains in order to learn if there is any relation to Gulf Coast strains prevalent in the USA, but until now we have not found any V. cholerae ribotype 2 in our isolates. Even if rapid tests are recommended for immediate diagnosis of cholera, it is necessary to continue bacterial isolation in order to have strains for phenotyping and genotyping studies that may support epidemiological analysis.

  16. Platformed antagonism: Racist discourses on fake Muslim Facebook pages

    DEFF Research Database (Denmark)

    Farkas, Johan; Schou, Jannick; Neumayer, Christina

    2018-01-01

    This research examines how fake identities on social media create and sustain antagonistic and racist discourses. It does so by analysing 11 Danish Facebook pages, disguised as Muslim extremists living in Denmark, conspiring to kill and rape Danish citizens. It explores how anonymous content...... producers utilize Facebook's socio-technical characteristics to construct, what we propose to term as, platformed antagonism. This term refers to socio-technical and discursive practices that produce new modes of antagonistic relations on social media platforms. Through a discourse-theoretical analysis...... of posts, images, 'about' sections and user comments on the studied Facebook pages, the article highlights how antagonism between ethno-cultural identities is produced on social media through fictitious social media accounts, prompting thousands of user reactions. These findings enhance our current...

  17. Luminescence, virulence and quorum sensing signal production by pathogenic Vibrio campbellii and Vibrio harveyi isolates

    OpenAIRE

    Defoirdt, T.; Verstraete, W.; Bossier, P.

    2008-01-01

    Aims: To study the relationship between luminescence, autoinducer production and virulence of pathogenic vibrios.Methods and Results: Luminescence, quorum sensing signal production and virulence towards brine shrimp nauplii of 13 Vibrio campbellii and Vibrio harveyi strains were studied. Although only two of the tested strains were brightly luminescent, all of them were shown to produce the three different types of quorum sensing signals known to be produced by Vibrio harveyi. Cell-free cultu...

  18. Interleukin-1 Antagonism Decreases Cortisol Levels in Obese Individuals

    OpenAIRE

    Urwyler, Sandrine Andrea; Schuetz, Philipp; Ebrahimi, Fahim; Donath, Marc Y.; Christ-Crain, Mirjam

    2017-01-01

    Increased cortisol levels in obesity may contribute to the associated metabolic syndrome. In obesity, the activated innate immune system leads to increased interleukin (IL)-1β, which is known to stimulate the release of adrenocorticotropin hormone (ACTH).; We hypothesized that in obesity IL-1 antagonism would result in downregulation of the hypothalamo-pituitary-adrenal axis, leading to decreased cortisol levels.; In this prospective intervention study, we included 73 patients with obesity (b...

  19. Antagonism of Innate Immunity by Paramyxovirus Accessory Proteins

    Directory of Open Access Journals (Sweden)

    Raychel Chambers

    2009-10-01

    Full Text Available Paramyxovirinae, a subfamily of Paramyxoviridae, are negative strand RNA viruses comprised of many important human and animal pathogens, which share a high degree of genetic and structural homology. The accessory proteins expressed from the P/V/C gene are major factors in the pathogenicity of the viruses, because of their ability to abrogate various facets of type I interferon (IFN induction and signaling. Most of the paramyxoviruses exhibit a commonality in their ability to antagonize innate immunity by blocking IFN induction and the Jak/STAT pathway. However, the manner in which the accessory proteins inhibit the pathway differs among viruses. Similarly, there are variations in the capability of the viruses to counteract intracellular detectors (RNA helicases, mda-5 and RIG-I. Furthermore, a functional specificity in the antagonism of the IFN response has been reported, suggesting that specificity in the circumvention of innate immunity restricts viral host range. Available evidence indicates that paramyxoviruses employ specific strategies to antagonize the IFN response of their specific hosts, which is one of the major factors that determine viral pathogenicity and host range.

  20. A survey of oysters (Crassostrea gigas) in New Zealand for Vibrio parahaemolyticus and Vibrio vulnificus.

    Science.gov (United States)

    Kirs, M; Depaola, A; Fyfe, R; Jones, J L; Krantz, J; Van Laanen, A; Cotton, D; Castle, M

    2011-05-27

    A microbiological survey was conducted to determine the levels of total and pathogenic Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) in Pacific oysters (Crassostrea gigas) collected from commercial growing areas in the North Island, New Zealand. The survey was intended to be geographically representative of commercial growing areas of Pacific oysters in New Zealand, while selecting the time frame most likely to coincide with the increased abundance of pathogenic vibrio species. Vp was detected in 94.8% of oyster samples examined (n=58) with a geometric mean concentration of 99.3 MPN/g, while Vv was detected in 17.2% of oyster samples examined with a geometric mean concentration of 7.4 MPN/g. The frequency of Vp positive samples was 1.7 fold greater than reported in a study conducted three decades ago in New Zealand. Potentially virulent (tdh positive) Vp was detected in two samples (3.4%, n=58) while no trh (another virulence marker) positive samples were detected. 16S rRNA genotype could be assigned only to 58.8% of Vv isolates (8:1:1 A:B:AB ratio, n=10). There was a good agreement [98.2% of Vp (n=280) and 94.4% of Vv (n=18) isolates] between molecular tests and cultivation based techniques used to identify Vibrio isolates and there was a significant (R(2)=0.95, Pcultivation. There was no significant correlation between any of the environmental parameters tested and Vp or Vv concentrations. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Regulation of Metalloprotease Gene Expression in Vibrio vulnificus by a Vibrio harveyi LuxR Homologue

    Science.gov (United States)

    Shao, Chung-Ping; Hor, Lien-I

    2001-01-01

    Expression of the Vibrio vulnificus metalloprotease gene, vvp, was turned up rapidly when bacterial growth reached the late log phase. A similar pattern of expression has been found in the metalloprotease gene of Vibrio cholerae, and this has been shown to be regulated by a Vibrio harveyi LuxR-like transcriptional activator. To find out whether a LuxR homologue exists in V. vulnificus, a gene library of this organism was screened by colony hybridization using a probe derived from a sequence that is conserved in various luxR-like genes of vibrios. A gene containing a 618-bp open reading frame was identified and found to be identical to the smcR gene of V. vulnificus reported previously. An isogenic SmcR-deficient (RD) mutant was further constructed by an in vivo allelic exchange technique. This mutant exhibited an extremely low level of vvp transcription compared with that of the parent strain. On the other hand, the cytolysin gene, vvhA, was expressed at a higher level in the RD mutant than in the parent strain during the log phase of growth. These data suggested that SmcR might not only be a positive regulator of the protease gene but might also be involved in negative regulation of the cytolysin gene. Virulence of the RD mutant in either normal or iron-overloaded mice challenged by intraperitoneal injection was comparable to that of the parent strain, indicating that SmcR is not required for V. vulnificus virulence in mice. PMID:11157950

  2. Vibrio lentus protects gnotobiotic sea bass (Dicentrarchus labrax L.) larvae against challenge with Vibrio harveyi.

    Science.gov (United States)

    Schaeck, M; Duchateau, L; Van den Broeck, W; Van Trappen, S; De Vos, P; Coulombet, C; Boon, N; Haesebrouck, F; Decostere, A

    2016-03-15

    Due to the mounting awareness of the risks associated with the use of antibiotics in aquaculture, treatment with probiotics has recently emerged as the preferred environmental-friendly prophylactic approach in marine larviculture. However, the presence of unknown and variable microbiota in fish larvae makes it impossible to disentangle the efficacy of treatment with probiotics. In this respect, the recent development of a germ-free culture model for European sea bass (Dicentrarchus labrax L.) larvae opened the door for more controlled studies on the use of probiotics. In the present study, 206 bacterial isolates, retrieved from sea bass larvae and adults, were screened in vitro for haemolytic activity, bile tolerance and antagonistic activity against six sea bass pathogens. Subsequently, the harmlessness and the protective effect of the putative probiotic candidates against the sea bass pathogen Vibrio harveyi were evaluated in vivo adopting the previously developed germ-free sea bass larval model. An equivalence trial clearly showed that no harmful effect on larval survival was elicited by all three selected probiotic candidates: Bacillus sp. LT3, Vibrio lentus and Vibrio proteolyticus. Survival of Vibrio harveyi challenged larvae treated with V. lentus was superior in comparison with the untreated challenged group, whereas this was not the case for the larvae supplemented with Bacillus sp. LT3 and V. proteolyticus. In this respect, our results unmistakably revealed the protective effect of V. lentus against vibriosis caused by V. harveyi in gnotobiotic sea bass larvae, rendering this study the first in its kind. Copyright © 2016. Published by Elsevier B.V.

  3. Antibiotic Resistant Salmonella and Vibrio Associated with Farmed Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Sanjoy Banerjee

    2012-01-01

    Full Text Available Salmonella and Vibrio species were isolated and identified from Litopenaeus vannamei cultured in shrimp farms. Shrimp samples showed occurrence of 3.3% of Salmonella and 48.3% of Vibrio. The isolates were also screened for antibiotic resistance to oxolinic acid, sulphonamides, tetracycline, sulfamethoxazole/trimethoprim, norfloxacin, ampicillin, doxycycline hydrochloride, erythromycin, chloramphenicol, and nitrofurantoin. Salmonella enterica serovar Corvallis isolated from shrimp showed individual and multiple antibiotic resistance patterns. Five Vibrio species having individual and multiple antibiotic resistance were also identified. They were Vibrio cholerae (18.3%, V. mimicus (16.7%, V. parahaemolyticus (10%, V. vulnificus (6.7%, and V. alginolyticus (1.7%. Farm owners should be concerned about the presence of these pathogenic bacteria which also contributes to human health risk and should adopt best management practices for responsible aquaculture to ensure the quality of shrimp.

  4. QStatin, a Selective Inhibitor of Quorum Sensing in Vibrio Species.

    Science.gov (United States)

    Kim, Byoung Sik; Jang, Song Yee; Bang, Ye-Ji; Hwang, Jungwon; Koo, Youngwon; Jang, Kyung Ku; Lim, Dongyeol; Kim, Myung Hee; Choi, Sang Ho

    2018-01-30

    Pathogenic Vibrio species cause diseases in diverse marine animals reared in aquaculture. Since their pathogenesis, persistence, and survival in marine environments are regulated by quorum sensing (QS), QS interference has attracted attention as a means to control these bacteria in aquatic settings. A few QS inhibitors of Vibrio species have been reported, but detailed molecular mechanisms are lacking. Here, we identified a novel, potent, and selective Vibrio QS inhibitor, named QStatin [1-(5-bromothiophene-2-sulfonyl)-1H-pyrazole], which affects Vibrio harveyi LuxR homologues, the well-conserved master transcriptional regulators for QS in Vibrio species. Crystallographic and biochemical analyses showed that QStatin binds tightly to a putative ligand-binding pocket in SmcR, the LuxR homologue in V. vulnificus , and changes the flexibility of the protein, thereby altering its transcription regulatory activity. Transcriptome analysis revealed that QStatin results in SmcR dysfunction, affecting the expression of SmcR regulon required for virulence, motility/chemotaxis, and biofilm dynamics. Notably, QStatin attenuated representative QS-regulated phenotypes in various Vibrio species, including virulence against the brine shrimp ( Artemia franciscana ). Together, these results provide molecular insights into the mechanism of action of an effective, sustainable QS inhibitor that is less susceptible to resistance than other antimicrobial agents and useful in controlling the virulence of Vibrio species in aquacultures. IMPORTANCE Yields of aquaculture, such as penaeid shrimp hatcheries, are greatly affected by vibriosis, a disease caused by pathogenic Vibrio infections. Since bacterial cell-to-cell communication, known as quorum sensing (QS), regulates pathogenesis of Vibrio species in marine environments, QS inhibitors have attracted attention as alternatives to conventional antibiotics in aquatic settings. Here, we used target-based high-throughput screening to identify

  5. Autoinducers act as biological timers in Vibrio harveyi

    OpenAIRE

    Anetzberger, C.; Reiger, M.; Fekete, A.; Schell, U.; Stambrau, N.; Plener, L.; Kopka, J.; Schmitt-Kopplin, P.; Hilbi, H.; Jung, K.

    2012-01-01

    Quorum sensing regulates cell density-dependent phenotypes and involves the synthesis, excretion and detection of so-called autoinducers. Vibrio harveyi strain ATCC BAA-1116 (recently reclassified as Vibrio campbellii), one of the best-characterized model organisms for the study of quorum sensing, produces and responds to three autoinducers. HAI-1, AI-2 and CAI-1 are recognized by different receptors, but all information is channeled into the same signaling cascade, which controls a specific ...

  6. A selective and differential medium for Vibrio harveyi.

    OpenAIRE

    Harris, L; Owens, L; Smith, S

    1996-01-01

    A new medium, termed Vibrio harveyi agar, has been developed for the isolation and enumeration of V. harveyi. It is possible to differentiate V. harveyi colonies from the colonies of strains representing 15 other Vibrio species with this medium. This medium has been shown to inhibit the growth of two strains of marine Pseudomonas spp. and two strains of marine Flavobacterium spp. but to allow the growth of Photobacterium strains. Colonies displaying typical V. harveyi morphology were isolated...

  7. Characterization of Vibrio species isolated from freshwater fishes by ribotyping

    OpenAIRE

    Mishra, P.; Samanta, M.; Mohanty, S.; Maiti, N. K.

    2010-01-01

    Three Vibrio species from the resident microflora of gastrointestinal tract of freshwater carps and prawns were isolated and confirmed biochemically as V. fluvialis from Cyprinus carpio/Labeo rohita; V. parahaemolyticus from Macrobrachium rosenbergii and V. harveyi from Macrobrachium malcomsoni. The genetic relationship among these Vibrio species was carried out by polymerase chain reaction (PCR) amplification of 16S rRNA gene followed by restriction digestion with Hae III, Bam HI and Pst I. ...

  8. Septicemia caused by Vibrio parahemolyticus: a case report.

    Science.gov (United States)

    Hsu, G J; Young, T; Peng, M Y; Chang, F Y; Chou, M Y

    1993-11-01

    Vibrio parahemolyticus is a halophilic marine vibrio commonly associated with outbreaks of acute gastroenteritis which also sometimes causes serious wound infection. It is an uncommon cause of septicemia. A few reports suggest that patients with chronic liver disease and leukemia are more susceptible. A case of liver cirrhosis with septicemia caused by this organism is discussed. The patient's condition rapidly deteriorated, and he died 12 hours after admission.

  9. Passive Immune-Protection of Litopenaeus vannamei against Vibrio harveyi and Vibrio parahaemolyticus Infections with Anti-Vibrio Egg Yolk (IgY-Encapsulated Feed

    Directory of Open Access Journals (Sweden)

    Xiaojian Gao

    2016-05-01

    Full Text Available Vibrio spp. are major causes of mortality in white shrimp (Litopenaeus vannamei which is lacking adaptive immunity. Passive immunization with a specific egg yolk antibody (IgY is a potential method for the protection of shrimp against vibriosis. In this study, immune effects of the specific egg yolk powders (IgY against both V. harveyi and V. parahaemolyticus on white shrimp were evaluated. The egg yolk powders against V. harveyi and V. parahaemolyticus for passive immunization of white shrimp were prepared, while a tube agglutination assay and an indirect enzyme-linked immunosorbent assay (ELISA were used for detection of IgY titer. Anti-Vibrio egg yolk was encapsulated by β-cyclodextrin, which could keep the activity of the antibody in the gastrointestinal tract of shrimp. The results showed that the anti-Vibrio egg powders had an inhibiting effect on V. harveyi and V. parahaemolyticus in vitro. Lower mortality of infected zoeae, mysis, and postlarva was observed in groups fed with anti-Vibrio egg powders, compared with those fed with normal egg powders. The bacterial load in postlarva fed with specific egg powders in seeding ponds was significantly lower than those fed with normal egg powders in seeding ponds. These results show that passive immunization by oral administration with specific egg yolk powders (IgY may provide a valuable protection of vibrio infections in white shrimp.

  10. Occurance and survival of Vibrio alginolyticus in Tamouda Bay (Morocco).

    Science.gov (United States)

    Sabir, M; Cohen, N; Boukhanjer, A; Ennaji, M M

    2011-10-15

    The objectives of this study were to investigate the spatial and seasonal fluctuations of Vibrio alginolyticus in marine environment of the Tamouda Bay on the Mediterranean coast of Morocco and to determine the dominant factors of the environment that govern these fluctuations. The samples (sea water, plankton, shellfish and sediment) were collected fortnightly for two years from three study sites on the coast Tamouda Bay in northern Morocco. The charge of Vibrio alginolyticus is determined by MPN method. The physicochemical parameters including temperature of sea water, pH, salinity, turbidity and chlorophyll a concentration were determined. Analysis of variance of specific variables and several principal component analyses showed that the temperature of seawater is the major determinant of seasonal distribution of Vibrio alginolyticus. The results showed a positive linear correlation between Vibrio alginolyticus and the water temperature, pH, turbidity and chlorophyll a. Similarly, there are seasonal variations and spatial of Vibrio alginolyticus in marine environment of the Tamouda bay and the highest concentrations were recorded in both years of study during the warm season whereas it was minimal during the cold season. Linear positive correlation was recorded between Vibrio alginolyticus populations in all ecological types of samples studied.

  11. VISCOSITY DICTATES METABOLIC ACTIVITY of Vibrio ruber

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    Maja eBoric

    2012-07-01

    Full Text Available Little is known about metabolic activity of bacteria, when viscosity of their environment changes. In this work, bacterial metabolic activity in media with viscosity ranging from 0.8 to 29.4 mPas was studied. Viscosities up to 2.4 mPas did not affect metabolic activity of Vibrio ruber. On the other hand, at 29.4 mPas respiration rate and total dehydrogenase activity increased 8 and 4-fold, respectively. The activity of glucose-6-phosphate dehydrogenase increased up to 13-fold at higher viscosities. However, intensified metabolic activity did not result in faster growth rate. Increased viscosity delayed the onset as well as the duration of biosynthesis of prodigiosin. As an adaptation to viscous environment V. ruber increased metabolic flux through the pentose phosphate pathway and reduced synthesis of a secondary metabolite. In addition, V. ruber was able to modify the viscosity of its environment.

  12. Intestinal Colonization Dynamics of Vibrio cholerae.

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    Salvador Almagro-Moreno

    2015-05-01

    Full Text Available To cause the diarrheal disease cholera, Vibrio cholerae must effectively colonize the small intestine. In order to do so, the bacterium needs to successfully travel through the stomach and withstand the presence of agents such as bile and antimicrobial peptides in the intestinal lumen and mucus. The bacterial cells penetrate the viscous mucus layer covering the epithelium and attach and proliferate on its surface. In this review, we discuss recent developments and known aspects of the early stages of V. cholerae intestinal colonization and highlight areas that remain to be fully understood. We propose mechanisms and postulate a model that covers some of the steps that are required in order for the bacterium to efficiently colonize the human host. A deeper understanding of the colonization dynamics of V. cholerae and other intestinal pathogens will provide us with a variety of novel targets and strategies to avoid the diseases caused by these organisms.

  13. Vibrio vulnificus: An Environmental and Clinical Burden

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    Sing-Peng Heng

    2017-05-01

    Full Text Available Vibrio vulnificus is a Gram negative, rod shaped bacterium that belongs to the family Vibrionaceae. It is a deadly, opportunistic human pathogen which is responsible for the majority of seafood-associated deaths worldwide. V. vulnificus infection can be fatal as it may cause severe wound infections potentially requiring amputation or lead to sepsis in susceptible individuals. Treatment is increasingly challenging as V. vulnificus has begun to develop resistance against certain antibiotics due to their indiscriminate use. This article aims to provide insight into the antibiotic resistance of V. vulnificus in different parts of the world as well as an overall review of its clinical manifestations, treatment, and prevention. Understanding the organism's antibiotic resistance profile is vital in order to select appropriate treatment and initiate appropriate prevention measures to treat and control V. vulnificus infections, which should eventually help lower the mortality rate associated with this pathogen worldwide.

  14. Interleukin-1 Antagonism Decreases Cortisol Levels in Obese Individuals.

    Science.gov (United States)

    Urwyler, Sandrine Andrea; Schuetz, Philipp; Ebrahimi, Fahim; Donath, Marc Y; Christ-Crain, Mirjam

    2017-05-01

    Increased cortisol levels in obesity may contribute to the associated metabolic syndrome. In obesity, the activated innate immune system leads to increased interleukin (IL)-1β, which is known to stimulate the release of adrenocorticotropin hormone (ACTH). We hypothesized that in obesity IL-1 antagonism would result in downregulation of the hypothalamo-pituitary-adrenal axis, leading to decreased cortisol levels. In this prospective intervention study, we included 73 patients with obesity (body mass index [BMI] ≥30 kg/m2) and at least one additional feature of the metabolic syndrome. The primary end point was change in morning cortisol from baseline to after the administration of the IL-1 receptor antagonist (anakinra/Kineret®, total dose 3 × 100 mg). Secondary end points were effects on salivary cortisol and ACTH. Median age was 56 years, 50.7% of patients were female, and median BMI was 36.3 kg/m2. Median morning serum cortisol levels (nmol/L) decreased significantly after IL-1 antagonism [from baseline, 452 to 423; absolute difference, -38.7; 95% confidence interval (CI), -64 to -13.4; P = 0.0019]. Similar effects were found for salivary cortisol levels (-2.8; 95% CI, -4.4 to -1.3; P = 0.0007), ACTH levels (-2.2; 95% CI; -4.2 to -0.1; P = 0.038), systolic blood pressure (-5.2, 95% CI, -8.5 to -1.8; P = 0.0006), and heart rate (-2.9; 95% CI, -4.7 to -1.0; P = 0.0029). IL-1 antagonism in obese individuals with features of the metabolic syndrome leads to a decrease in serum cortisol, salivary cortisol, and ACTH levels along with a reduction in systolic blood pressure and heart rate. Copyright © 2017 Endocrine Society

  15. Liquid holding recovery and photoreactivation of the ultraviolet-inactivated vibrios

    International Nuclear Information System (INIS)

    Banerjee, S.K.; Chatterjee, S.N.

    1981-01-01

    The kinetics of liquid holding recovery and photoreactivation of the ultra-violet-inactivated vibrios have been investigated. Photoreactivation was highest (about 80%) for Vibrio cholerae (classical) strains but the liquid holding recovery was highest (about 29%) for Vibrio parahemolyticus ones. Significance of the differences between any two of the four vibrio biotypes in respect of their liquid holding recovery and also photoreactivation was analysed statistically. (auth.)

  16. Mortalities of Eastern and Pacific oyster Larvae caused by the pathogens Vibrio coralliilyticus and Vibrio tubiashii.

    Science.gov (United States)

    Richards, Gary P; Watson, Michael A; Needleman, David S; Church, Karlee M; Häse, Claudia C

    2015-01-01

    Vibrio tubiashii is reported to be a bacterial pathogen of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) and has been associated with major hatchery crashes, causing shortages in seed oysters for commercial shellfish producers. Another bacterium, Vibrio coralliilyticus, a well-known coral pathogen, has recently been shown to elicit mortality in fish and shellfish. Several strains of V. coralliilyticus, such as ATCC 19105 and Pacific isolates RE22 and RE98, were misidentified as V. tubiashii until recently. We compared the mortalities caused by two V. tubiashii and four V. coralliilyticus strains in Eastern and Pacific oyster larvae. The 50% lethal dose (LD50) of V. coralliilyticus in Eastern oysters (defined here as the dose required to kill 50% of the population in 6 days) ranged from 1.1 × 10(4) to 3.0 × 10(4) CFU/ml seawater; strains RE98 and RE22 were the most virulent. This study shows that V. coralliilyticus causes mortality in Eastern oyster larvae. Results for Pacific oysters were similar, with LD50s between 1.2 × 10(4) and 4.0 × 10(4) CFU/ml. Vibrio tubiashii ATCC 19106 and ATCC 19109 were highly infectious toward Eastern oyster larvae but were essentially nonpathogenic toward healthy Pacific oyster larvae at dosages of ≥1.1 × 10(4) CFU/ml. These data, coupled with the fact that several isolates originally thought to be V. tubiashii are actually V. coralliilyticus, suggest that V. coralliilyticus has been a more significant pathogen for larval bivalve shellfish than V. tubiashii, particularly on the U.S. West Coast, contributing to substantial hatchery-associated morbidity and mortality in recent years. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  17. Flumazenil antagonizes the central effects of zolpidem, an imidazopyridine hypnotic.

    Science.gov (United States)

    Patat, A; Naef, M M; van Gessel, E; Forster, A; Dubruc, C; Rosenzweig, P

    1994-10-01

    Zolpidem is a new imidazopyridine-hypnotic that selectively binds to the central omega 1-receptor subtype. A double-blind, randomized, three-way, crossover placebo-controlled study was carried out in nine healthy male volunteers to assess the possible antagonism of central nervous system--depressant effects of zolpidem by flumazenil. Subjects received zolpidem (0.21 mg/kg) or placebo, intravenously, followed 17 minutes later by flumazenil (0.04 mg/kg) or placebo. Vigilance and performance were assessed by a trained anesthetist with use of ciliary reflex, response to a verbal instruction, subjective sedation, a tracking task, and a free recall task. Zolpidem produced a clinically relevant hypnotic effect in five subjects and significantly impaired performance in all nine subjects up to 90 minutes after dosing. Flumazenil rapidly antagonized clinical sedation in the five subjects who were asleep and significantly reversed the performance decrement within 3 minutes, without any escape phenomenon. Flumazenil did not change zolpidem plasma concentrations, confirming the pharmacodynamic nature of the interaction. Flumazenil may thus be a safe and effective antidote in patients with zolpidem overdosage.

  18. Prevalence study of Vibrio species and frequency of the virulence genes of Vibrio parahaemolyticus isolated from fresh and salted shrimps in Genaveh seaport

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    S Hosseini

    2014-08-01

    Full Text Available Vibrio species are important seafood-borne pathogens that are responsible for 50-70% of gasteroenteritis. The present study was carried out in order to determine the prevalence of Vibrio species and the distribution of tdh, tlh and trh virulence genes in Vibrio parahaemolyticus isolated from fresh and salted shrimp samples. Totally, 60 fresh and salted shrimp samples were collected from the Genaveh seaport. Microbial culture was used to isolate Vibrio species. In addition, the presences of Vibrio parahaemolyticus, Vibrio cholera, Vibrio vulnificus and Vibrio harveyi and the virulence genes of V. parahaemolyticus were studied using the PCR method. Results showed that 20% of fresh and 23.33% of salted shrimp samples were positive for Vibrio species. In studied samples, V. vulnificus had the highest prevalence rate (8.33%, while V. cholera had the lowest prevalence rate (1.66%. From a total of 4 detected V. parahaemolyticus, all of them had tlh gene (100%. The distribution of tdh and trh genes in isolated V. parahaemolyticus strains were 50% and 25%, respectively. High prevalence of Vibrio species and especially virulent V. parahaemolyticus in samples confirmed the lack of hygienic condition in the production and distribution centers of shrimp.

  19. Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species

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    Erika Acosta-Smith

    2018-01-01

    Full Text Available Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species.

  20. Bovine Lactoferrin and Lactoferrin-Derived Peptides Inhibit the Growth of Vibrio cholerae and Other Vibrio species

    Science.gov (United States)

    Acosta-Smith, Erika; Viveros-Jiménez, Karina; Canizalez-Román, Adrian; Reyes-Lopez, Magda; Bolscher, Jan G. M.; Nazmi, Kamran; Flores-Villaseñor, Hector; Alapizco-Castro, Gerardo; de la Garza, Mireya; Martínez-Garcia, Jesús J.; Velazquez-Roman, Jorge; Leon-Sicairos, Nidia

    2018-01-01

    Vibrio is a genus of Gram-negative bacteria, some of which can cause serious infectious diseases. Vibrio infections are associated with the consumption of contaminated food and classified in Vibrio cholera infections and non-cholera Vibrio infections. In the present study, we investigate whether bovine lactoferrin (bLF) and several synthetic peptides corresponding to bLF sequences, are able to inhibit the growth or have bactericidal effect against V. cholerae and other Vibrio species. The antibacterial activity of LF and LF-peptides was assessed by kinetics of growth or determination of colony forming unit in bacteria treated with the peptides and antibiotics. To get insight in the mode of action, the interaction between bLF and bLF-peptides (coupled to FITC) and V. cholera was evaluated. The damage of effector-induced bacterial membrane permeability was measured by inclusion of the fluorescent dye propidium iodide using flow cytometry, whereas the bacterial ultrastructural damage in bacteria treated was observed by transmission electron microscopy. The results showed that bLF and LFchimera inhibited the growth of the V. cholerae strains; LFchimera permeabilized the bacteria which membranes were seriously damaged. Assays with a multidrug-resistant strain of Vibrio species indicated that combination of sub-lethal doses of LFchimera with ampicillin or tetracycline strongly reduced the concentration of the antibiotics to reach 95% growth inhibition. Furthermore, LFchimera were effective to inhibit the V. cholerae counts and damage due to this bacterium in a model mice. These data suggest that LFchimera and bLF are potential candidates to combat the V. cholerae and other multidrug resistant Vibrio species. PMID:29375503

  1. Proteomics Analysis Reveals Previously Uncharacterized Virulence Factors in Vibrio proteolyticus

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    Ann Ray

    2016-07-01

    Full Text Available Members of the genus Vibrio include many pathogens of humans and marine animals that share genetic information via horizontal gene transfer. Hence, the Vibrio pan-genome carries the potential to establish new pathogenic strains by sharing virulence determinants, many of which have yet to be characterized. Here, we investigated the virulence properties of Vibrio proteolyticus, a Gram-negative marine bacterium previously identified as part of the Vibrio consortium isolated from diseased corals. We found that V. proteolyticus causes actin cytoskeleton rearrangements followed by cell lysis in HeLa cells in a contact-independent manner. In search of the responsible virulence factor involved, we determined the V. proteolyticus secretome. This proteomics approach revealed various putative virulence factors, including active type VI secretion systems and effectors with virulence toxin domains; however, these type VI secretion systems were not responsible for the observed cytotoxic effects. Further examination of the V. proteolyticus secretome led us to hypothesize and subsequently demonstrate that a secreted hemolysin, belonging to a previously uncharacterized clan of the leukocidin superfamily, was the toxin responsible for the V. proteolyticus-mediated cytotoxicity in both HeLa cells and macrophages. Clearly, there remains an armory of yet-to-be-discovered virulence factors in the Vibrio pan-genome that will undoubtedly provide a wealth of knowledge on how a pathogen can manipulate host cells.

  2. Abundance and antibiotic susceptibility of Vibrio spp. isolated from microplastics

    Science.gov (United States)

    Laverty, A. L.; Darr, K.; Dobbs, F. C.

    2016-02-01

    In recent years, there has been a growing concern for `microplastics' (particles pieces, paired seawater samples, and from them cultured 44 putative Vibrio spp. isolates, 18 of which were PCR-confirmed as V. parahaemolyticus and 3 as V. vulnificus. There were no PCR-confirmed V. cholerae isolates. We used the Kirby-Bauer disk diffusion susceptibility test to examine the isolates' response to six antibiotics: chloramphenicol (30μg), gentamicin (10μg), ampicillin (10μg), streptomycin (10μg), tetracycline (30μg), and rifampin (5μg). Vibrio isolates were susceptible to three or more of the six antibiotics tested and all were susceptible to tetracycline and chloramphenicol. There were no apparent differences between the antibiotic susceptibilities of vibrios isolated from microplastics compared to those from the water column. In every instance tested, vibrios on microplastics were enriched by at least two orders of magnitude compared to those from paired seawater samples. This study demonstrates that microplastic particles serve as a habitat for Vibrio species, in particular V. vulnificus and V. parahaemolyticus, confirming the conjecture of Zettler et al. (2013) that plastics may serve as a vector for these and other potentially pathogenic bacteria.

  3. Entry of Vibrio harveyi and Vibrio fischeri into the viable but nonculturable state.

    Science.gov (United States)

    Ramaiah, N; Ravel, J; Straube, W L; Hill, R T; Colwell, R R

    2002-01-01

    Physiological responses of marine luminous bacteria, Vibrio harveyi (ATCC 14216) and V. fischeri (UM1373) to nutrient-limited normal strength (35 ppt iso-osmolarity) and low (10 ppt hypo-osmolarity) salinity conditions were determined. Plate counts, direct viable counts, actively respiring cell counts, nucleoid-containing cell counts, and total counts were determined. Vibrio harveyi incubated at 22 degrees C in nutrient-limited artificial seawater (ASW) became nonculturable after approximately 62 and 45 d in microcosms of 35 ppt and 10 ppt ASW, respectively. In contrast, V. fischeri became nonculturable at approximately 55 and 31 d in similar microcosms. Recovery of both culturability and luminescence of cells in the viable but nonculturable state was achieved by addition of nutrient broth or nutrient broth supplemented with a carbon source, including luminescence-stimulating compounds. Temperature upshift from 22 degrees C to 30 degrees C or 37 degrees C did not result in recovery from nonculturability. The study confirms entry of V. harveyi and V. fischeri into the viable but nonculturable state under low-nutrient conditions and demonstrates nutrient-dependent resuscitation from this state. This study confirms loss of luminescence of V. harveyi and V. fischeri on entry into the viable but nonculturable state and suggests that enumeration of luminescent cells in water samples may be a rapid method to deduce the nutrient status of a water sample.

  4. Vibrio parahaemolyticus- An emerging foodborne pathogen

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    S Nelapati

    2012-02-01

    Full Text Available Vibrio parahaemolyticus is a halophilic gram negative, motile, oxidase positive, straight or curved rod-shaped, facultative anaerobic bacteria that occur naturally in the marine environment. They form part of the indigenous microflora of aquatic habitats of various salinity and are the major causative agents for some of the most serious diseases in fish, shellfish and penacid shrimp. This human pathogen causes acute gastroenteritis characterized by diarrhea, vomiting and abdominal cramps through consumption of contaminated raw fish or shellfish. V. parahaemolyticus is the leading cause of gastroenteritis due to the consumption of seafood worldwide. The incidence of V. parahaemolyticus infection has been increasing in many parts of the world, due to the emergence of O3:K6 serotype carrying the tdh gene which is responsible for most outbreaks worldwide. The pathogenicity of this organism is closely correlated with the Kanagawa phenomenon (KP + due to production of Kanagawa hemolysin or the thermostable direct hemolysin (TDH. The TDH and TRH (TDH-related hemolysin encoded by tdh and trh genes are considered to be important virulence factors. [Vet. World 2012; 5(1.000: 48-63

  5. Cell vacuolation caused by Vibrio cholerae hemolysin.

    Science.gov (United States)

    Figueroa-Arredondo, P; Heuser, J E; Akopyants, N S; Morisaki, J H; Giono-Cerezo, S; Enríquez-Rincón, F; Berg, D E

    2001-03-01

    Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (approximately 1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (approximately 16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses.

  6. Relationship of aquatic environmental factors with the abundance of Vibrio cholerae, Vibrio parahaemolyticus, Vibrio mimicus and Vibrio vulnificus in the coastal area of Guaymas, Sonora, Mexico.

    Science.gov (United States)

    León Robles, A; Acedo Félix, E; Gomez-Gil, B; Quiñones Ramírez, E I; Nevárez-Martínez, M; Noriega-Orozco, L

    2013-12-01

    Members of the genus Vibrio are common in aquatic environments. Among them are V. cholerae, V. vulnificus, V. parahaemolyticus and V. mimicus. Several studies have shown that environmental factors, such as temperature, salinity, and dissolved oxygen, are involved in their epidemiology. Therefore, the main objective of this study is to determine if there is a correlation between the presence/amount of V. cholerae, V, vulnificus, V. parahaemolyticus and V. mimicus and the environmental conditions of the seawater off the coast of Guaymas, México. Quantification of all four pathogenic bacteria was performed using the most probable number method, and suspected colonies were identified by polymerase chain reaction (PCR). Correlations were found using principal component analysis. V. parahaemolyticus was the most abundant and widely distributed bacteria, followed by V. vulnificus, V. mimicus and V. cholerae. Positive correlations between V. parahaemolyticus, V. vulnificus and V. mimicus with temperature, salinity, electric conductivity, and total dissolved solids were found. The abundance of V. cholerae was mainly affected by the sampling site and not by physicochemical parameters.

  7. A pan-European ring trial to validate an International Standard for detection of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus in seafoods.

    Science.gov (United States)

    Hartnell, R E; Stockley, L; Keay, W; Rosec, J-P; Hervio-Heath, D; Van den Berg, H; Leoni, F; Ottaviani, D; Henigman, U; Denayer, S; Serbruyns, B; Georgsson, F; Krumova-Valcheva, G; Gyurova, E; Blanco, C; Copin, S; Strauch, E; Wieczorek, K; Lopatek, M; Britova, A; Hardouin, G; Lombard, B; In't Veld, P; Leclercq, A; Baker-Austin, C

    2018-02-10

    Globally, vibrios represent an important and well-established group of bacterial foodborne pathogens. The European Commission (EC) mandated the Comite de European Normalisation (CEN) to undertake work to provide validation data for 15 methods in microbiology to support EC legislation. As part of this mandated work programme, merging of ISO/TS 21872-1:2007, which specifies a horizontal method for the detection of V. parahaemolyticus and V. cholerae, and ISO/TS 21872-2:2007, a similar horizontal method for the detection of potentially pathogenic vibrios other than V. cholerae and V. parahaemolyticus was proposed. Both parts of ISO/TS 21872 utilized classical culture-based isolation techniques coupled with biochemical confirmation steps. The work also considered simplification of the biochemical confirmation steps. In addition, because of advances in molecular based methods for identification of human pathogenic Vibrio spp. classical and real-time PCR options were also included within the scope of the validation. These considerations formed the basis of a multi-laboratory validation study with the aim of improving the precision of this ISO technical specification and providing a single ISO standard method to enable detection of these important foodborne Vibrio spp.. To achieve this aim, an international validation study involving 13 laboratories from 9 countries in Europe was conducted in 2013. The results of this validation have enabled integration of the two existing technical specifications targeting the detection of the major foodborne Vibrio spp., simplification of the suite of recommended biochemical identification tests and the introduction of molecular procedures that provide both species level identification and discrimination of putatively pathogenic strains of V. parahaemolyticus by the determination of the presence of theromostable direct and direct related haemolysins. The method performance characteristics generated in this have been included in revised

  8. Multiple enzymatic profiles of Vibrio parahaemolyticus strains isolated from oysters

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    Renata Albuquerque Costa

    Full Text Available The enzymatic characterization of vibrios has been used as a virulence indicator of sanitary interest. The objective of this study was to determine the enzymatic profile of Vibrio parahaemolyticus strains (n = 70 isolated from Crassostrea rhizophorae oysters. The strains were examined for the presence of gelatinase (GEL, caseinase (CAS, elastase (ELAS, phospholipase (PHOS, lipase (LIP, amilase (AML and DNase. All enzymes, except elastase, were detected in more than 60% of the strains. The most recurrent enzymatic profiles were AML + DNase + PHOS + GEL + LIP (n = 16; 22.9% and AML + CAS + DNase + PHOS + GEL + LIP (n = 21; 30%. Considering the fact that exoenzyme production by vibrios is closely related to virulence, one must be aware of the bacteriological risk posed to human health by the consumption of raw or undercooked oysters.

  9. Insights into bacteriophage application in controlling Vibrio species

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    Vengadesh Letchumanan

    2016-07-01

    Full Text Available Bacterial infections from various organisms including Vibrio sp. pose a serious hazard to humans in many forms from clinical infection to affecting the yield of agriculture and aquaculture via infection of livestock. Vibrio sp. is one of the main foodborne pathogens causing human infection and is also a common cause of losses in the aquaculture industry. Prophylactic and therapeutic usage of antibiotics has become the mainstay of managing this problem, however this in turn led to the emergence of multidrug resistant strains of bacteria in the environment; which has raised awareness of the critical need for alternative non antibiotic based methods of preventing and treating bacterial infections. Bacteriophages - viruses that infect and result in the death of bacteria – are currently of great interest as a highly viable alternative to antibiotics. This article provides an insight into bacteriophage application in controlling Vibrio species as well underlining the advantages and drawbacks of phage therapy.

  10. A selective and differential medium for Vibrio harveyi.

    Science.gov (United States)

    Harris, L; Owens, L; Smith, S

    1996-01-01

    A new medium, termed Vibrio harveyi agar, has been developed for the isolation and enumeration of V. harveyi. It is possible to differentiate V. harveyi colonies from the colonies of strains representing 15 other Vibrio species with this medium. This medium has been shown to inhibit the growth of two strains of marine Pseudomonas spp. and two strains of marine Flavobacterium spp. but to allow the growth of Photobacterium strains. Colonies displaying typical V. harveyi morphology were isolated from the larval rearing water of a commercial prawn hatchery with V. harveyi agar as a primary isolation medium and were positively identified, by conventional tests, as V. harveyi. This agar displays great potential as a primary isolation medium and offers significant advantages over thiosulfate-citrate-bile salts-sucrose agar as a medium for differentiating V. harveyi from other marine and estuarine Vibrio species. PMID:8795252

  11. Chitovibrin: a chitin-binding lectin from Vibrio parahemolyticus.

    Science.gov (United States)

    Gildemeister, O S; Zhu, B C; Laine, R A

    1994-12-01

    A novel 134 kDa, calcium-independent chitin-binding lectin, 'chitovibrin', is secreted by the marine bacterium Vibrio parahemolyticus, inducible with chitin or chitin-oligomers. Chitovibrin shows no apparent enzymatic activity but exhibits a strong affinity for chitin and chito-oligomers > dp9. The protein has an isoelectric pH of 3.6, shows thermal tolerance, binds chitin with an optimum at pH 6 and is active in 0-4 M NaCl. Chitovibrin appears to be completely different from other reported Vibrio lectins and may function to bind V. parahemolyticus to chitin substrates, or to capture or sequester chito-oligomers. It may be a member of a large group of recently described proteins in Vibrios related to a complex chitinoclastic (chitinivorous) system.

  12. Ozone Technology for Pathogenic Bacteria of Shrimp (Vibrio sp.) Disinfection

    Science.gov (United States)

    Wulansarie, Ria; Dyah Pita Rengga, Wara; Rustamadji

    2018-03-01

    One of important marine commodities in Indonesia, shrimps are susceptible with Vibrio sp bacteria infection. That infection must be cleared. One of the technologies for disinfecting Vibrio sp. is ozone technology. In this research, Vibrio sp. is a pathogenic bacterium which infects Penaeus vannamei. Ozone technology is applied for threatening Vibrio sp. In this research, ozonation was performed in different pH. Those are neutral, acid (pH=4), and base (pH=9). The sample was water from shrimp embankment from Balai Besar Perikanan Budidaya Air Payau (BBPBAP) located in Jepara. That water was the habitat of Penaeus vannamei shrimp. The brand of ozonator used in this research was “AQUATIC”. The used ozonator in this research had 0,0325 g/hour concentration. The flow rate of sample used in this research was 2 L/minute. The ozonation process was performed in continuous system. A tank, pipe, pump, which was connected with microfilter, flowmeter and ozone generator were the main tools in this research. It used flowmeter and valve to set the flow rate scalable as desired. The first step was the insert of 5 L sample into the receptacle. Then, by using a pump, a sample supplied to the microfilter to be filtered and passed into the flow meter. The flow rate was set to 2 LPM. Furthermore, gas from ozonator passed to the flow for the disinfection of bacteria and then was recycled to the tank and the process run continuously. Samples of the results of ozonation were taken periodically from time 0, 3, 7, 12, 18, 24 to 30 minutes. The samples of the research were analyzed using Total Plate Count (TPC) test in BBPBAP Jepara to determine the number of Vibrio sp. bacteria. The result of this research was the optimal condition for pathogenic bacteria of shrimp (Vibrio sp.) ozonation was in neutral condition.

  13. Calcitonin gene-related peptide antagonism and cluster headache

    DEFF Research Database (Denmark)

    Ashina, Håkan; Newman, Lawrence; Ashina, Sait

    2017-01-01

    Calcitonin gene-related peptide (CGRP) is a key signaling molecule involved in migraine pathophysiology. Efficacy of CGRP monoclonal antibodies and antagonists in migraine treatment has fueled an increasing interest in the prospect of treating cluster headache (CH) with CGRP antagonism. The exact...... role of CGRP and its mechanism of action in CH have not been fully clarified. A search for original studies and randomized controlled trials (RCTs) published in English was performed in PubMed and in ClinicalTrials.gov . The search term used was "cluster headache and calcitonin gene related peptide......" and "primary headaches and calcitonin gene related peptide." Reference lists of identified articles were also searched for additional relevant papers. Human experimental studies have reported elevated plasma CGRP levels during both spontaneous and glyceryl trinitrate-induced cluster attacks. CGRP may play...

  14. Interferon Induction by RNA Viruses and Antagonism by Viral Pathogens

    Directory of Open Access Journals (Sweden)

    Yuchen Nan

    2014-12-01

    Full Text Available Interferons are a group of small proteins that play key roles in host antiviral innate immunity. Their induction mainly relies on host pattern recognition receptors (PRR. Host PRR for RNA viruses include Toll-like receptors (TLR and retinoic acid-inducible gene I (RIG-I like receptors (RLR. Activation of both TLR and RLR pathways can eventually lead to the secretion of type I IFNs, which can modulate both innate and adaptive immune responses against viral pathogens. Because of the important roles of interferons, viruses have evolved multiple strategies to evade host TLR and RLR mediated signaling. This review focuses on the mechanisms of interferon induction and antagonism of the antiviral strategy by RNA viruses.

  15. Extinction antagonizes olfactory memory at the subcellular level.

    Science.gov (United States)

    Schwaerzel, Martin; Heisenberg, Martin; Zars, Troy

    2002-08-29

    Memory loss occurs by diverse mechanisms, as different time constants of performance decrement and sensitivities to experimental manipulations suggest. While the phenomena of memory decay, interference, and extinction are well established behaviorally, little is known about them at the circuit or molecular level. In Drosophila, odorant memories lasting up to 3 hr can be localized to mushroom body Kenyon cells, a single neuronal level in the olfactory pathway. The plasticity underlying this memory trace can be induced without Kenyon cell synaptic output. Experimental extinction, i.e., presentation of the conditioned stimulus without the reinforcer, reduces memory performance and does so at the same circuit level as memory formation. Thus, unreinforced presentation of learned odorants antagonizes intracellularly the signaling cascade underlying memory formation.

  16. Long-term effects of ocean warming on vibrios

    Science.gov (United States)

    Pruzzo, C.; Pezzati, E.; Brettar, I.; Reid, P. C.; Colwell, R.; Höfle, M. G.; vezzulli, L.

    2012-12-01

    Vibrios are a major source of human disease, play an important role in the ecology and health of marine animals and are regarded as an abundant fraction of culturable bacteria of the ocean. There has been a considerable global effort to reduce the risk of Vibrio infections and yet in most countries both human and non-human illnesses associated with these bacteria are increasing. The cause of this increase is not known, but since vibrios are strongly thermodependant there is good reason to believe that global warming may have contributed. To investigate this possibility we examined historical samples from the Continuous Plankton Recorder (CPR) archive using advanced molecular analysis and pyrosequencing. For the first time we were able to recover environmental DNA from CPR samples that had been stored for up to ~50 years in a formalin-fixed format, which is suitable for molecular analyses of the associated prokaryotic community. To overcome the problem of DNA degradation due to the sample age and storage in formalin we develop an unbiased index of abundance for Vibrio quantification in CPR samples termed a 'relative Vibrio Abundance Index' (VAI). VAI is defined as the ratio of Vibrio spp. cells to total bacterial cells assessed by Real-Time PCR using genus-specific and universal primers, respectively, producing small amplicons of similar size (~100bp). We assessed VAI index on 55 samples (each representing 10 nautical miles tow equal to 3 m3 of filtered sewater) collected in August by the CPR survey in the North Sea from off the Rhine and Humber estuaries between 1961 to 2005 showing that the genus Vibrio has increased in prevalence in the last 44 years and that this increase is correlated significantly, during the same period, with warming sea surface temperature. In addition, by applying deep sequencing analysis of a subset of these samples we provide evidence that bacteria belonging to the genus Vibrio, including the human pathogen V. cholerae, not only increased

  17. Vibrio infections in Louisiana: twenty-five years of surveillance 1980-2005.

    Science.gov (United States)

    Thomas, Annu; Straif-Bourgeois, Susanne; Sokol, Theresa M; Ratard, Raoult C

    2007-01-01

    A total of 1,007 Vibrio infections were reported to the Infectious Disease Epidemiology Department at the Louisiana Office of Public Heath, between 1980 and 2005. The most common were Vibrio vulnificus (257 infections), Vibrio parahemolyticus (249 infections), and Vibrio cholerae non O1 (200 cases). Other species were much less common. Vibrio vulnificus infections, which are associated with consumption of raw seafood (particularly oysters) or contact with sea water, and severe immuno-suppression or liver disease were increasing. Septicemia and blood stream infections are the main manifestations of this infection. The number of infections due to Vibrio parahemolyticus on the other hand, causing mostly gastroenteritis, has remained stable. Vibrio cholerae infections are less common and almost always associated with consumption of partially cooked or contaminated crabs.

  18. Cell Vacuolation Caused by Vibrio cholerae Hemolysin

    Science.gov (United States)

    Figueroa-Arredondo, Paula; Heuser, John E.; Akopyants, Natalia S.; Morisaki, J. Hiroshi; Giono-Cerezo, Silvia; Enríquez-Rincón, Fernando; Berg, Douglas E.

    2001-01-01

    Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (∼1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (∼16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses. PMID:11179335

  19. Development and efficacy of an attenuated Vibrio harveyi vaccine candidate with cross protectivity against Vibrio alginolyticus.

    Science.gov (United States)

    Hu, Yong-hua; Deng, Tian; Sun, Bo-guang; Sun, Li

    2012-06-01

    Vibrio harveyi is a Gram-negative bacterial pathogen that can infect a wide range of marine animals. In previous studies, we have reported a virulent V. harveyi strain, T4D. In the present study, an attenuated mutant of T4D, T4DM, was obtained by selection of rifampicin resistance. Compared to the wild type, T4DM was different in whole-cell protein profile and much slower in growth rate when cultured in stress conditions caused by iron depletion. Virulence analysis showed that compared to T4D, T4DM exhibited a dramatically increased median lethal dose, impaired tissue dissemination capacity, defective hemolytic activity, and significantly reduced resistance against the killing effect of host serum. To examine the potential of T4DM as a live attenuated vaccine, Japanese flounder (Paralichthys olivaceus) were vaccinated with T4DM via intraperitoneal injection or immersion. The results showed that at one and two months post-vaccination, fish administered with T4DM via both approaches, in particular that of immersion, were effectively protected against not only V. harveyi but also Vibrio alginolyticus, another important fish pathogen. Microbiological analysis showed that following immersion vaccination, T4DM was recovered from the internal organs of the vaccinated fish in a time-dependent manner within the first 6 days post-vaccination. Serum antibodies against V. harveyi and V. alginolyticus were detected in T4DM-vaccinated fish, and, compared to serum from control fish, serum from T4DM-vaccinated fish was significantly enhanced in bactericidal activity. These results indicate that T4DM is an attenuated strain with residual infectivity and that T4DM can induce effective cross-species protection against both V. harveyi and V. alginolyticus when used as a live immersion vaccine. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. The evolution of reduced antagonism--A role for host-parasite coevolution.

    Science.gov (United States)

    Gibson, A K; Stoy, K S; Gelarden, I A; Penley, M J; Lively, C M; Morran, L T

    2015-11-01

    Why do some host-parasite interactions become less antagonistic over evolutionary time? Vertical transmission can select for reduced antagonism. Vertical transmission also promotes coevolution between hosts and parasites. Therefore, we hypothesized that coevolution itself may underlie transitions to reduced antagonism. To test the coevolution hypothesis, we selected for reduced antagonism between the host Caenorhabditis elegans and its parasite Serratia marcescens. This parasite is horizontally transmitted, which allowed us to study coevolution independently of vertical transmission. After 20 generations, we observed a response to selection when coevolution was possible: reduced antagonism evolved in the copassaged treatment. Reduced antagonism, however, did not evolve when hosts or parasites were independently selected without coevolution. In addition, we found strong local adaptation for reduced antagonism between replicate host/parasite lines in the copassaged treatment. Taken together, these results strongly suggest that coevolution was critical to the rapid evolution of reduced antagonism. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  1. Localization of immunodominant linear B-cell epitopes of Vibrio ...

    African Journals Online (AJOL)

    Outer membrane protein U (OmpU), an adhesion protein of Vibrio mimicus, is a good antigen, but its epitopes are still unclear. In order to locate the epitopes of OmpU protein, epitope prediction was performed using the amino acid sequence of OmpU protein of V. mimicus HX4 strain that was isolated from the diseased ...

  2. Pseudomonas piscicida kills vibrios by two distinct mechanisms

    Science.gov (United States)

    Pseudoalteromonas piscicida is a naturally-occurring marine bacterium which kills competing bacteria, including vibrios. In studies by Richards et al. (AEM00175-17), three strains of P. piscicida were isolated and characterized. Strains secreted proteolytic enzymes which likely killed competing or...

  3. Vibrio Cholerae 01 Infections In Jos, Nigeria | Opajobi | African ...

    African Journals Online (AJOL)

    A study to determine the prevalence of Vibrio cholerae 01 in stool sample submitted for routine examination of enteric pathogens, as well as identify the serotypes and antibiogram of the isolates to commonly used antibiotics was undertaken. The survey involved the examination of 774 (763 stool and 11 rectal swabs) ...

  4. Outbreak of Vibrio parahaemolyticus Sequence Type 120, Peru, 2009.

    Science.gov (United States)

    Gonzalez-Escalona, Narjol; Gavilan, Ronnie G; Toro, Magaly; Zamudio, Maria L; Martinez-Urtaza, Jaime

    2016-07-01

    In 2009, an outbreak of Vibrio parahaemolyticus occurred in Piura, Cajamarca, Lambayeque, and Lima, Peru. Whole-genome sequencing of clinical and environmental samples from the outbreak revealed a new V. parahaemolyticus clone. All the isolates identified belonged to a single clonal complex described exclusively in Asia before its emergence in Peru.

  5. Molecular analysis of the emergence of pandemic Vibrio parahaemolyticus

    DEFF Research Database (Denmark)

    Boyd, EF; Cohen, AL; Naughton, LM

    2008-01-01

    Background Vibrio parahaemolyticus is abundant in the aquatic environment particularly in warmer waters and is the leading cause of seafood borne gastroenteritis worldwide. Prior to 1995, numerous V. parahaemolyticus serogroups were associated with disease, however, in that year an O3:K6 serogrou...

  6. Vibrio trends in the ecology of the Venice lagoon.

    Science.gov (United States)

    Rahman, Mohammad Shamsur; Martino, Maria Elena; Cardazzo, Barbara; Facco, Pierantonio; Bordin, Paola; Mioni, Renzo; Novelli, Enrico; Fasolato, Luca

    2014-04-01

    Vibrio is a very diverse genus that is responsible for different human and animal diseases. The accurate identification of Vibrio at the species level is important to assess the risks related to public health and diseases caused by aquatic organisms. The ecology of Vibrio spp., together with their genetic background, represents an important key for species discrimination and evolution. Thus, analyses of population structure and ecology association are necessary for reliable characterization of bacteria and to investigate whether bacterial species are going through adaptation processes. In this study, a population of Vibrionaceae was isolated from shellfish of the Venice lagoon and analyzed in depth to study its structure and distribution in the environment. A multilocus sequence analysis (MLSA) was developed on the basis of four housekeeping genes. Both molecular and biochemical approaches were used for species characterization, and the results were compared to assess the consistency of the two methods. In addition, strain ecology and the association between genetic information and environment were investigated through statistical models. The phylogenetic and population analyses achieved good species clustering, while biochemical identification was demonstrated to be imprecise. In addition, this study provided a fine-scale overview of the distribution of Vibrio spp. in the Venice lagoon, and the results highlighted a preferential association of the species toward specific ecological variables. These findings support the use of MLSA for taxonomic studies and demonstrate the need to consider environmental information to obtain broader and more accurate bacterial characterization.

  7. In situ measured elimination of Vibrio cholerae from brackish water

    Czech Academy of Sciences Publication Activity Database

    Martínez-P., M. E.; Macek, Miroslav; Castro-G., M. T.

    2004-01-01

    Roč. 9, č. 1 (2004), s. 133-140 ISSN 1360-2276 R&D Projects: GA MŠk(CZ) ME 296 Grant - others:UNAM/DGAPA/PAPIT(MX) IN216796 Keywords : Vibrio cholerae * protozoan feeding * brackish water Subject RIV: EE - Microbiology, Virology Impact factor: 1.969, year: 2004

  8. Survival of Vibrio cholerae in industrially polluted water, with ...

    African Journals Online (AJOL)

    containing industrial effluents. The effect of iron as well as pH on the survival of Vibrio cholerae (non-O1, El Tor and classical strains) in water samples from 12 points, where selected industrial effluents were discharged into rivers, was studied.

  9. Detection of quorum sensing molecules from Vibrio harveyi and use ...

    African Journals Online (AJOL)

    This paper explores the extraction and detection processes of quorum sensing molecules such as N-aceyl homoserine lactone compounds (AHL) from marine Vibrio harveyi. The spent culture of V. harveyi was solvent partitioned for AHL, rotary evaporated and re-suspended in 50% acetonitrile then detected with reporter ...

  10. Salmonella and Vibrio cholerae in Nile perch ( Lates niloticus ...

    African Journals Online (AJOL)

    The Nile perch (Lates niloticus) industry in East Africa has suffered severe economic losses in the last few years due to failure to comply with the microbiological standards of European Union (E.U). Fresh and frozen products have been suspected to be contaminated with Salmonella and Vibrio cholerae. This has led to a ...

  11. Isolation and molecular identification of Vibrio spp. by sequencing of ...

    African Journals Online (AJOL)

    Out of the 93 cultured samples only 48 (51.6%) yielded colonies on Thiosulfate Citrate Bile Salt agar (TCBS) with culture characteristics of Vibrio spp. More than half (n=27) of processed seafood samples (n=46) yielded colonies on TCBS, while only 44.6% of samples of meat and meat products showed colonies on TCBS.

  12. Natural modulators of Vibrios in seawater and shellfish

    Science.gov (United States)

    Naturally occurring marine bacteria, Vibrio parahaemolyticus and V. vulnificus, are major threats to the safety of molluscan shellfish in the US and elsewhere. Illnesses range from mild gastrointestinal upset to septicemia and death. In studies on the uptake and persistence of V. parahaemolyticus ...

  13. antimicrobial susceptibility pattern of vibrio cholerae 01 strains

    African Journals Online (AJOL)

    hi-tech

    East African Medical Journal Vol. 77 No. 7 July 2000. ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF VIBRIO CHOLERAE 01 STRAINS DURING TWO CHOLERA OUTBREAKS IN DAR ES SALAAM,. TANZANIA. W.K. Urassa, MD, MSc, MMed, Lecturer, Department of Microbiology and Immunology, Muhimbili University ...

  14. Cooperation, Trust, and Antagonism: How Public Goods Are Promoted.

    Science.gov (United States)

    Parks, Craig D; Joireman, Jeff; Van Lange, Paul A M

    2013-12-01

    One of the most continually vexing problems in society is the variability with which citizens support endeavors that are designed to help a great number of people. In this article, we examine the twin roles of cooperative and antagonistic behavior in this variability. We find that each plays an important role, though their contributions are, understandably, at odds. It is this opposition that produces seeming unpredictability in citizen response to collective need. In fact, we suggest that careful consideration of the research allows one to often predict when efforts to provide a collectively beneficial good will succeed and when they will fail. To understand the dynamics of participation in response to collective need, it is necessary to distinguish between the primary types of need situations. A public good is an entity that relies in whole or in part on contributions to be provided. Examples of public goods are charities and public broadcasting. Public goods require that citizens experience a short-term loss (of their contribution) in order to realize a long-term gain (of the good). However, because everyone can use the good once it is provided, there is also an incentive to not contribute, let others give, and then take advantage of their efforts. This state of affairs introduces a conflict between doing what is best for oneself and what is best for the group. In a public goods situation, cooperation and antagonism impact how one resolves this conflict. The other major type of need situation is a common-pool resource problem. Here, a good is fully provided at the outset, and citizens may sample from it. The resource is usually, but not necessarily, partially replenished. Examples of replenished resources are drinking water and trees; examples of resources that are functionally not replenished are oil and minerals. Common-pool resources allow citizens to experience a short-term gain (by getting what they want in the early life of the resource) but also present

  15. Household Transmission of Vibrio cholerae in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Jonathan D Sugimoto

    2014-11-01

    Full Text Available Vibrio cholerae infections cluster in households. This study's objective was to quantify the relative contribution of direct, within-household exposure (for example, via contamination of household food, water, or surfaces to endemic cholera transmission. Quantifying the relative contribution of direct exposure is important for planning effective prevention and control measures.Symptom histories and multiple blood and fecal specimens were prospectively collected from household members of hospital-ascertained cholera cases in Bangladesh from 2001-2006. We estimated the probabilities of cholera transmission through 1 direct exposure within the household and 2 contact with community-based sources of infection. The natural history of cholera infection and covariate effects on transmission were considered. Significant direct transmission (p-value<0.0001 occurred among 1414 members of 364 households. Fecal shedding of O1 El Tor Ogawa was associated with a 4.9% (95% confidence interval: 0.9%-22.8% risk of infection among household contacts through direct exposure during an 11-day infectious period (mean length. The estimated 11-day risk of O1 El Tor Ogawa infection through exposure to community-based sources was 2.5% (0.8%-8.0%. The corresponding estimated risks for O1 El Tor Inaba and O139 infection were 3.7% (0.7%-16.6% and 8.2% (2.1%-27.1% through direct exposure, and 3.4% (1.7%-6.7% and 2.0% (0.5%-7.3% through community-based exposure. Children under 5 years-old were at elevated risk of infection. Limitations of the study may have led to an underestimation of the true risk of cholera infection. For instance, available covariate data may have incompletely characterized levels of pre-existing immunity to cholera infection. Transmission via direct exposure occurring outside of the household was not considered.Direct exposure contributes substantially to endemic transmission of symptomatic cholera in an urban setting. We provide the first estimate of

  16. Isolation and molecular identification of Vibrio spp. by sequencing of 16S rDNA from seafood, meat and meat products in Libya

    OpenAIRE

    S.M. Azwai; E.A. Alfallani; S.K. Abolghait; A.M. Garbaj; H.T. Naas; A.A. Moawad; F.T. Gammoudi; H.M. Rayes; I. Barbieri; I.M. Eldaghayes

    2016-01-01

    The genus Vibrio includes several food-borne pathogens that cause a spectrum of clinical conditions including septicemia, cholera and milder forms of gastroenteritis. Several Vibrio spp. are commonly associated with food-borne transmission including Vibrio cholerae, Vibrio parahemolyticus, and Vibrio vulnificus. Microbiological analysis for enumeration and isolation of Vibrio spp. were carried out for a total of 93 samples of seafood, meat and meat products from different geographic localitie...

  17. Vibrio vulnificus phage PV94 is closely related to temperate phages of V. cholerae and other Vibrio species.

    Directory of Open Access Journals (Sweden)

    Mark Pryshliak

    Full Text Available BACKGROUND: Vibrio vulnificus is an important pathogen which can cause serious infections in humans. Yet, there is limited knowledge on its virulence factors and the question whether temperate phages might be involved in pathogenicity, as is the case with V. cholerae. Thus far, only two phages (SSP002 and VvAW1 infecting V. vulnificus have been genetically characterized. These phages were isolated from the environment and are not related to Vibrio cholerae phages. The lack of information on temperate V. vulnificus phages prompted us to isolate those phages from lysogenic strains and to compare them with phages of other Vibrio species. RESULTS: In this study the temperate phage PV94 was isolated from a V. vulnificus biotype 1 strain by mitomycin C induction. PV94 is a myovirus whose genome is a linear double-stranded DNA of 33,828 bp with 5'-protruding ends. Sequence analysis of PV94 revealed a modular organization of the genome. The left half of the genome comprising the immunity region and genes for the integrase, terminase and replication proteins shows similarites to V. cholerae kappa phages whereas the right half containing genes for structural proteins is closely related to a prophage residing in V. furnissii NCTC 11218. CONCLUSION: We present the first genomic sequence of a temperate phage isolated from a human V. vulnificus isolate. The sequence analysis of the PV94 genome demonstrates the wide distribution of closely related prophages in various Vibrio species. Moreover, the mosaicism of the PV94 genome indicates a high degree of horizontal genetic exchange within the genus Vibrio, by which V. vulnificus might acquire virulence-associated genes from other species.

  18. Kefiran antagonizes cytopathic effects of Bacillus cereus extracellular factors.

    Science.gov (United States)

    Medrano, Micaela; Pérez, Pablo Fernando; Abraham, Analía Graciela

    2008-02-29

    Kefiran, the polysaccharide produced by microorganisms present in kefir grains, is a water-soluble branched glucogalactan containing equal amounts of D-glucose and D-galactose. In this study, the effect of kefiran on the biological activity of Bacillus cereus strain B10502 extracellular factors was assessed by using cultured human enterocytes (Caco-2 cells) and human erythrocytes. In the presence of kefiran concentrations ranging from 300 to 1000 mg/L, the ability of B. cereus B10502 spent culture supernatants to detach and damage cultured human enterocytes was significantly abrogated. In addition, mitochondrial dehydrogenase activity was higher when kefiran was present during the cell toxicity assays. Protection was also demonstrated in hemolysis and apoptosis/necrosis assays. Scanning electron microscopy showed the protective effect of kefiran against structural cell damages produced by factors synthesized by B. cereus strain B10502. Protective effect of kefiran depended on strain of B. cereus. Our findings demonstrate the ability of kefiran to antagonize key events of B. cereus B10502 virulence. This property, although strain-specific, gives new perspectives for the role of bacterial exopolysaccharides in functional foods.

  19. Heterodimerization of Msx and Dlx homeoproteins results in functional antagonism.

    Science.gov (United States)

    Zhang, H; Hu, G; Wang, H; Sciavolino, P; Iler, N; Shen, M M; Abate-Shen, C

    1997-05-01

    Protein-protein interactions are known to be essential for specifying the transcriptional activities of homeoproteins. Here we show that representative members of the Msx and Dlx homeoprotein families form homo- and heterodimeric complexes. We demonstrate that dimerization by Msx and Dlx proteins is mediated through their homeodomains and that the residues required for this interaction correspond to those necessary for DNA binding. Unlike most other known examples of homeoprotein interactions, association of Msx and Dlx proteins does not promote cooperative DNA binding; instead, dimerization and DNA binding are mutually exclusive activities. In particular, we show that Msx and Dlx proteins interact independently and noncooperatively with homeodomain DNA binding sites and that dimerization is specifically blocked by the presence of such DNA sites. We further demonstrate that the transcriptional properties of Msx and Dlx proteins display reciprocal inhibition. Specifically, Msx proteins act as transcriptional repressors and Dlx proteins act as activators, while in combination, Msx and Dlx proteins counteract each other's transcriptional activities. Finally, we show that the expression patterns of representative Msx and Dlx genes (Msx1, Msx2, Dlx2, and Dlx5) overlap in mouse embryogenesis during limb bud and craniofacial development, consistent with the potential for their protein products to interact in vivo. Based on these observations, we propose that functional antagonism through heterodimer formation provides a mechanism for regulating the transcriptional actions of Msx and Dlx homeoproteins in vivo.

  20. Requirements within the Ebola Viral Glycoprotein for Tetherin Antagonism

    Directory of Open Access Journals (Sweden)

    Nathan H. Vande Burgt

    2015-10-01

    Full Text Available Tetherin is an interferon-induced, intrinsic cellular response factor that blocks release of numerous viruses, including Ebola virus, from infected cells. As with many viruses targeted by host factors, Ebola virus employs a tetherin antagonist, the viral glycoprotein (EboGP, to counteract restriction and promote virus release. Unlike other tetherin antagonists such as HIV-1 Vpu or KSHV K5, the features within EboGP needed to overcome tetherin are not well characterized. Here, we describe sequences within the EboGP ectodomain and membrane spanning domain (msd as necessary to relieve tetherin restriction of viral particle budding. Fusing the EboGP msd to a normally secreted form of the glycoprotein effectively promotes Ebola virus particle release. Cellular protein or lipid anchors could not substitute for the EboGP msd. The requirement for the EboGP msd was not specific for filovirus budding, as similar results were seen with HIV particles. Furthermore trafficking of chimeric proteins to budding sites did not correlate with an ability to counter tetherin. Additionally, we find that a glycoprotein construct, which mimics the cathepsin-activated species by proteolytic removal of the EboGP glycan cap and mucin domains, is unable to counteract tetherin. Combining these results suggests an important role for the EboGP glycan cap and msd in tetherin antagonism.

  1. Antagonism of rice phylloplane fungi against Cercospora oryzae

    Science.gov (United States)

    Mardani, A.; Hadiwiyono

    2018-03-01

    Narrow brown leaf spot (NBLS) caused by Cercospora oryzae Miyake is one of the important obstacle in rice cultivation that can decrease the productivity up to 40%. It has been known well that some phylloplane fungi are antagonistic to some leaf diseases. Phylloplane fungi of rice however haven’t been studied much and poorly understood as biological control agent of rice pathogen such C. oryzae. The research aimed to study the antagonism of some phylloplane fungi of rice against C. oryzae. At least 14 isolates of phylloplane fungi were collected which consisted of six pathogenic and eight nonpathogenic variants. All of nonpathogenic isolates were antagonistic against C. oryzae both in vitro and only one isolate could not inhibit the infection of the pathogen in vivo. Some isolates were identified as Aspergillus, Mucor, Penicillium, Fusarium, and Trichoderma. The isolate of Mucor and Fusarium could inhibit the highest growth of pathogen on potato dextrose medium that were at 36.0% and 35.5% respectively. Whereas on artificial inoculation on rice, some isolates such Penicillium and Fusarium could inhibit most effectively and were significantly different to Mencozeb application with dosage 5g L-1.

  2. Caffeine antagonism of alcohol-induced driving impairment.

    Science.gov (United States)

    Liguori, A; Robinson, J H

    2001-07-01

    The extent to which caffeine antagonizes alcohol-induced impairment of simulated automobile driving at the current lowest legal American limit (0.08% BrAC) was the focus of this study. Fifteen adults swallowed a capsule (0, 200, or 400 mg caffeine) then drank a beverage (0.0 or 0.6 g/kg ethanol) in a within-subject, double-blind, randomized procedure. Forty-five minutes later, participants completed a test battery of subjective effects scales, dynamic posturography, critical flicker fusion (CFF), choice reaction time (CRT), divided attention (Stroop test), and simulated driving. Alcohol alone increased ratings of 'dizzy', 'drug effect', and 'high', slowed CRT and brake latency, and increased body sway. Caffeine alone increased ratings of 'alert' and 'jittery', but did not significantly affect body sway or psychomotor performance. Both caffeine doses comparably counteracted alcohol impairment of brake latency but not CRT or body sway. Brake latency with either alcohol-caffeine combination remained significantly longer than that with placebo. Stroop and CFF performance were unaffected by any drug condition. The results suggest that caffeine may increase alertness and improve reaction time after alcohol use but will not completely counteract alcohol impairment in a driver.

  3. Notch pathway signaling in the skin antagonizes Merkel cell development.

    Science.gov (United States)

    Logan, Gregory J; Wright, Margaret C; Kubicki, Adam C; Maricich, Stephen M

    2018-02-15

    Merkel cells are mechanosensitive skin cells derived from the epidermal lineage whose development requires expression of the basic helix-loop-helix transcription factor Atoh1. The genes and pathways involved in regulating Merkel cell development during embryogenesis are poorly understood. Notch pathway signaling antagonizes Atoh1 expression in many developing body regions, so we hypothesized that Notch signaling might inhibit Merkel cell development. We found that conditional, constitutive overexpression of the Notch intracellular domain (NICD) in mouse epidermis significantly decreased Merkel cell numbers in whisker follicles and touch domes of hairy skin. Conversely, conditional deletion of the obligate NICD binding partner RBPj in the epidermis significantly increased Merkel cell numbers in whisker follicles, led to the development of ectopic Merkel cells outside of touch domes in hairy skin epidermis, and altered the distribution of Merkel cells in touch domes. Deletion of the downstream Notch effector gene Hes1 also significantly increased Merkel cell numbers in whisker follicles. Together, these data demonstrate that Notch signaling regulates Merkel cell production and patterning. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Vibrio Parahemolyticus in the Wastewater of Kermanshah City

    Directory of Open Access Journals (Sweden)

    Ali Almasi

    2005-11-01

    Full Text Available آب و فاضلاب                                                                                                                                                                                                               شماره 51- سال 1383     Municipal wastewater is one of the most important pollution sources for water supply resources. Soil, vegetable, and food material are exposed as well. Identification and enumeration of pathogenic agents particularly pathogenic Vibrios are beneficial for control and prevention planning of the infectious diseases. This research carried out to identify the distribution of the recognized pathogenic Vibrios emphasizing on identification of Vibrio cholerain the wastewater of city of Kermanshah in 2001. Population of city of Kermanshah was estimated over 713000 and produced wastewater was approximately 150 l/cap/d. The method of study was cross-sectional descriptive. Sampling procedure was adopted from standard Methods for the Examination of water and wastewater, and the method for Vibrios identification was according to finegold 1990. There were 8 discharge outlet domestic wastewaters, which had been chosen as sampling sites. Samples were collected weekly in randomized manner in day time. Although 288 samples should be collected statistically, 339 samples were collected and analyzed. The results indicated that site 7 with 5 positives, sites 4 and 8 with 3 positives, site 5 with 2 postitives and sites 2, 3 and 6 with one positive suspected to vibrio pathogens. However, not any Vibrio detected in site 1. The most positive samples were seen in spring, late summer and early autumn. The positive results were detected in May, June, September, and October. Among samples which have been detected as a

  5. MR findings of infectious myositis caused by vibrio vulnificus: case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon Ho; Na, Jae Boem [Gyeongsang National University College of Medicine, Jinju (Korea, Republic of)

    2003-03-01

    Vibrio vulnificus infection is a fatal disease occurring after the consumption of seafood in patients with underlying liver disease. Inflammation of the skin, subcutanous fat and fascia disseminates from the lower extremity to the trunk and upper extremity. Infection myositis caused by vibrio vulnificus is rare, and its MR findings have not been reported. We report these in a case of infectious myositis caused by vibrio vulnificus involving both lower extremities.

  6. MR findings of infectious myositis caused by vibrio vulnificus: case report

    International Nuclear Information System (INIS)

    Lee, Joon Ho; Na, Jae Boem

    2003-01-01

    Vibrio vulnificus infection is a fatal disease occurring after the consumption of seafood in patients with underlying liver disease. Inflammation of the skin, subcutanous fat and fascia disseminates from the lower extremity to the trunk and upper extremity. Infection myositis caused by vibrio vulnificus is rare, and its MR findings have not been reported. We report these in a case of infectious myositis caused by vibrio vulnificus involving both lower extremities

  7. Efek Antibakteri Ekstrak Daun Mimba (Azadirachta indica A. Juss) terhadap Bakteri Vibrio algynoliticus Secara In Vitro

    OpenAIRE

    Uli Ayini; Siti Harnina B.; Titis Candra Dewi

    2014-01-01

    Budidaya udang windu di Indonesia telah berkembang pesat. Salah satu kendala budidaya udang adalah penyakit Vibriosis yang disebabkan oleh bakteri Vibrio algynoliticus. Tujuan penelitian ini adalah untuk mengetahui efek antibakeri ekstrak daun mimba terhadap bakteri Vibrio algynoliticus. Penelitian ini menggunakan metode dilusi untuk mengetahui efek antibakteri ekstrak daun mimba terhadap bakteri Vibrio algynoliticus secara in vitro. Konsentrasi ekstrak yang digunakan (%) yaitu: 0; 2,5; 5; 7,...

  8. Emergent Patterns of Diversity and Dynamics in Natural Populations of Planktonic Vibrio Bacteria

    Science.gov (United States)

    2005-06-01

    1973. Ecology of Vibrio parahemolyticus in mixed-template amplifications: formation, consequences and elimination by Chesapeake Bay. J. Bacteriol. 113...Science 1930 and Engineering DOCTORAL DISSERTATION Emergent Patterns of Diversity and Dynamics in Natural Populations of Planktonic Vibrio Bacteria by...DYNAMICS IN NATURAL POPULATIONS OF PLANKTONIC VIBRIO BACTERIA by Janelle Ren6e Thompson B.S. Biological Sciences, Stanford University 1998 M.S

  9. Vibrio parahemolyticus septicaemia in a liver transplant patient: a case report

    OpenAIRE

    Fairweather Morgan G; Krishnan Sujatha; Fernando Rajeev R; Ericsson Charles D

    2011-01-01

    Abstract Introduction Vibrio parahemolyticus is the leading cause of vibrio-associated gastroenteritis in the United States of America, usually related to poor food handling; only rarely has it been reported to cause serious infections including sepsis and soft tissue infections. In contrast, Vibrio vulnificus is a well-known cause of septicaemia, especially in patients with cirrhosis. We present a patient with V. parahemolyticus sepsis who had an orthotic liver transplant in 2007 and was on ...

  10. Hemolytic and urease activities in vibrios isolated from fresh and frozen oysters

    Directory of Open Access Journals (Sweden)

    Renata Albuquerque Costa

    2013-01-01

    Full Text Available INTRODUCTION: The present study aimed to survey the Vibrio microbiota of oysters (Crassostrea rhizophorae obtained from restaurants in Fortaleza, State of Ceará, Brazil, and to identify virulence factors. METHODS: The isolated vibrios were submitted to biochemical identification and were tested for hemolytic and urease activities. RESULTS: The isolated strains belonged to 13 species, with predominance of Vibrio mimicus. Of the strain isolates only from fresh samples, 20.5% and 2.8% showed hemolytic and urease activities, respectively. CONCLUSIONS: The findings support the little-publicized claim that Vibrio species other than V. parahaemolyticus and V. vulnificus can represent a health risk to public health.

  11. Role and regulation of the orphan AphA protein of quorum sensing in pathogenic Vibrios.

    Science.gov (United States)

    Lu, Renfei; Osei-Adjei, George; Huang, Xinxiang; Zhang, Yiquan

    2018-03-01

    Quorum sensing (QS), a cell-to-cell communication process, is widely distributed in the bacterial kingdom. Bacteria use QS to control gene expression in response to cell density by detecting the signal molecules called autoinducers. AphA protein is the master QS regulator of vibrios operating at low cell density. It regulates the expression of a variety of genes, especially those encoding virulence factors, flagella/motility and biofilm formation. The role and regulation of AphA in vibrios, especially in human pathogenic vibrios, are summarized in this review. Clarification of the roles of AphA will help us to understand the pathogenesis of vibrios.

  12. Investigation of household contamination of Vibrio cholerae in Bangladesh

    DEFF Research Database (Denmark)

    Hossain, Zenat Zebin; Farhana, Israt; Mohan Tulsiani, Suhella

    . cholerae El Tor strain N16961, showed hemolysis and proteolysis activity but none of them exhibited any hemagglutinin activity on human erythrocytes. The study findings indicate that V. cholerae contamination is mostly originated in and around kitchen area rather than latrine area. Contaminated food...... and water supply may be the reason behind this relatively high presence of virulence factors in food plates and water pots. Direct exposure routes of disease transmission should be a major consideration in cholera prevention policies. Investigation of household contamination of Vibrio cholerae in Bangladesh......The role of in-house transmission on the incidence of Vibrio cholerae, the deadly waterborne pathogen, is still not developed. The aim of the current study was to investigate possible contamination routes in household domain for effective cholera control in Bangladesh. To examine the prevalence...

  13. Vibrio bacteria in raw oysters: managing risks to human health.

    Science.gov (United States)

    Froelich, Brett A; Noble, Rachel T

    2016-03-05

    The human-pathogenic marine bacteria Vibrio vulnificus and V. parahaemolyticus are strongly correlated with water temperature, with concentrations increasing as waters warm seasonally. Both of these bacteria can be concentrated in filter-feeding shellfish, especially oysters. Because oysters are often consumed raw, this exposes people to large doses of potentially harmful bacteria. Various models are used to predict the abundance of these bacteria in oysters, which guide shellfish harvest policy meant to reduce human health risk. Vibrio abundance and behaviour varies from site to site, suggesting that location-specific studies are needed to establish targeted risk reduction strategies. Moreover, virulence potential, rather than simple abundance, should be also be included in future modeling efforts. © 2016 The Author(s).

  14. The squid-Vibrio symbioses: from demes to genes.

    Science.gov (United States)

    Kimbell, Jennifer R; McFall-Ngai, Margaret J

    2003-04-01

    The monospecific light organ association between the Hawaiian sepiolid squid Euprymna scolopes and the marine luminous bacterium Vibrio fischeri has been used as a model for the study of the most common type of coevolved animal-bacterial interaction; i.e., the association of Gram-negative bacteria with the extracellular apical surfaces of polarized epithelia. Analysis of the squid-vibrio symbiosis has ranged from characterizations of the harvesting mechanisms by which the host ensures colonization by the appropriate symbiont to identification of bacteria-induced changes in host gene expression that accompany the establishment and maintenance of the relationship. Studies of this model have been enhanced by extensive collaboration with microbiologists, who are able to manipulate the genetics of the bacterial symbiont. The results of our studies have indicated that initiation and persistence of the association requires a complex, reciprocal molecular dialogue between these two phylogenetically distant partners.

  15. Characterization of the secretomes of two vibrios pathogenic to mollusks.

    Directory of Open Access Journals (Sweden)

    Stéphanie Madec

    Full Text Available Vibrio tapetis causes the brown ring disease in the Japanese clam Ruditapes philippinarum while Vibrio aestuarianus is associated with massive oyster mortalities. As extracellular proteins are often associated with the virulence of pathogenic bacteria, we undertook a proteomic approach to characterize the secretomes of both vibrios. The extracellular proteins (ECPs of both species were fractionated by SEC-FPLC and in vitro assays were performed to measure the effects of each fraction on hemocyte cellular parameters (phagocytosis and adhesion. Fractions showing a significant effect were subjected to SDS-PAGE, and proteins were identified by nano LC-MS/MS. 45 proteins were identified for V. aestuarianus and 87 for V. tapetis. Most of them belonged to outer membrane or were periplasmic, including porins or adhesins that were already described as virulence factors in other bacterial species. Others were transporter components, flagella proteins, or proteins of unknown function (14 and 15 respectively. Interestingly, for V. aestuarianus, we noted the secretion of 3 extracellular enzymes including the Vam metalloprotease and two other enzymes (one putative lipase and one protease. For V. tapetis, we identified five extracellular enymes, i.e. two different endochitinases, one protease, one lipase and an adhesin. A comparison of both secretomes also showed that only the putative extracellular lipase was common to both secretomes, underscoring the difference in pathogenicity mechanisms between these two species. Overall, these results characterize for the first time the secretomes of these two marine pathogenic vibrios and constitute a useful working basis to further analyze the contribution of specific proteins in the virulence mechanisms of these species.

  16. Marine Vibrio Species Produce the Volatile Organic Compound Acetone

    OpenAIRE

    Nemecek-Marshall, M.; Wojciechowski, C.; Kuzma, J.; Silver, G. M.; Fall, R.

    1995-01-01

    While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine...

  17. Impacts of Climatic Variability on Vibrio parahaemolyticus Outbreaks in Taiwan

    OpenAIRE

    Hsin-I Hsiao; Man-Ser Jan; Hui-Ju Chi

    2016-01-01

    This study aimed to investigate and quantify the relationship between climate variation and incidence of Vibrio parahaemolyticus in Taiwan. Specifically, seasonal autoregressive integrated moving average (ARIMA) models (including autoregression, seasonality, and a lag-time effect) were employed to predict the role of climatic factors (including temperature, rainfall, relative humidity, ocean temperature and ocean salinity) on the incidence of V. parahaemolyticus in Taiwan between 2000 and 201...

  18. Temperature affects species distribution in symbiotic populations of Vibrio spp.

    Science.gov (United States)

    Nishiguchi, M K

    2000-08-01

    The genus Sepiola (Cephalopoda: Sepiolidae) contains 10 known species that occur in the Mediterranean Sea today. All Sepiola species have a light organ that contains at least one of two species of luminous bacteria, Vibrio fischeri and Vibrio logei. The two Vibrio species coexist in at least four Sepiola species (S. affinis, S. intermedia, S. ligulata, and S. robusta), and their concentrations in the light organ depend on changes in certain abiotic factors, including temperature. Strains of V. fischeri grew faster in vitro and in Sepiola juveniles when they were incubated at 26 degrees C. In contrast, strains of V. logei grew faster at 18 degrees C in culture and in Sepiola juveniles. When aposymbiotic S. affinis or S. ligulata juveniles were inoculated with one Vibrio species, all strains of V. fischeri and V. logei were capable of infecting both squid species at the optimum growth temperatures, regardless of the squid host from which the bacteria were initially isolated. However, when two different strains of V. fischeri and V. logei were placed in direct competition with each other at either 18 or 26 degrees C, strains of V. fischeri were present in sepiolid light organs in greater concentrations at 26 degrees C, whereas strains of V. logei were present in greater concentrations at 18 degrees C. In addition to the competition experiments, the ratios of the two bacterial species in adult Sepiola specimens caught throughout the season at various depths differed, and these differences were correlated with the temperature in the surrounding environment. My findings contribute additional data concerning the ecological and environmental factors that affect host-symbiont recognition and may provide insight into the evolution of animal-bacterium specificity.

  19. Distribution ofVibrio cholerae in two Florida estuaries.

    Science.gov (United States)

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-04-01

    The distribution ofVibrio cholerae was examined in 2 Florida estuaries, Apalachicola and Tampa Bay.Vibrio cholerae serotype non-01 was the most abundant serotype, being isolated from 45% of the oyster samples, 30% of the sediments, 50% of the waters, and 75% of the blue crabs.Vibrio cholerae serotype 01 was isolated from only one oyster sample. Strong linear correlations betweenV. cholerae and temperature, salinity, or the other physical/chemical parameters measured,Escherichia coli, or fecal coliforms were not observed, but a range of temperatures and salinities appeared relevant to the distribution of the organism. The organism was present in the highest concentrations when salinities were 10‰-25‰ and temperatures were 20‡C-35‡C.In vitro growth curves of 95V. cholerae environmental isolates further supported that 10‰-25‰ was an ideal salinity range for the organisms. The results suggest thatV. cholerae is a widely distributed organism in the nutrient-rich warm waters of the Gulf Coast estuaries.

  20. [Characterization of haemolysis of the Vibrio parahaemolyticus no.93].

    Science.gov (United States)

    Su, S C; Lee, C Y

    1997-02-01

    Vibrio parahaemolyticus is a causative bacterium of food poisoning, and the haemolysin produced by this organism has been considered as one of the important virulence factors. In order to understand the pathogenic mechanism of this bacterium, the characteristics of haemolysin from Vibrio parahaemolyticus isolated from Taiwan were studied. One of the clinical strains, V. parahaemolyticus No.93, presents a weak hemolytic zone on 7% NaCl-Wagatsuma medium. The DNA hybridization results show that V. parahemolyticus has neither tdh nor trh gene. V. parahaemolyticus No.93 shows obviously hemolytic zone on 3%-NaCl Wagatsuma medium (human blood). The crude extracellular protein of V. parahaemolyticus No. 93 was evaluated for its heat tolerance and enzyme activities by media assay. The results show that this crude extracellular protein is thermolabile. The crude extracellular protein of V. parahaemolyticus No.93 was analyzed on 10% SDS-PAGE and an apparent band of 64 kDa protein was observed. Furthermore, the crude extracellular protein was analyzed by running gelatin-SDS-PAGE and hemoglobin-SDS-PAGE, and three clear zones on 62 kDa, 52 kDa and 41 kDa were observed on both SDS-PAGEs. Thus we propose that the crude extracellular protein of the V. parahaemolyticus No.93 can degrade gelatin as well as hemoglobin. Whether these protease being the virulence factors of Vibrio parahaemolyticus No.93 needs to be further studied.

  1. Saharan dust nutrients promote Vibrio bloom formation in marine surface waters.

    Science.gov (United States)

    Westrich, Jason R; Ebling, Alina M; Landing, William M; Joyner, Jessica L; Kemp, Keri M; Griffin, Dale W; Lipp, Erin K

    2016-05-24

    Vibrio is a ubiquitous genus of marine bacteria, typically comprising a small fraction of the total microbial community in surface waters, but capable of becoming a dominant taxon in response to poorly characterized factors. Iron (Fe), often restricted by limited bioavailability and low external supply, is an essential micronutrient that can limit Vibrio growth. Vibrio species have robust metabolic capabilities and an array of Fe-acquisition mechanisms, and are able to respond rapidly to nutrient influx, yet Vibrio response to environmental pulses of Fe remains uncharacterized. Here we examined the population growth of Vibrio after natural and simulated pulses of atmospherically transported Saharan dust, an important and episodic source of Fe to tropical marine waters. As a model for opportunistic bacterial heterotrophs, we demonstrated that Vibrio proliferate in response to a broad range of dust-Fe additions at rapid timescales. Within 24 h of exposure, strains of Vibrio cholerae and Vibrio alginolyticus were able to directly use Saharan dust-Fe to support rapid growth. These findings were also confirmed with in situ field studies; arrival of Saharan dust in the Caribbean and subtropical Atlantic coincided with high levels of dissolved Fe, followed by up to a 30-fold increase of culturable Vibrio over background levels within 24 h. The relative abundance of Vibrio increased from ∼1 to ∼20% of the total microbial community. This study, to our knowledge, is the first to describe Vibrio response to Saharan dust nutrients, having implications at the intersection of marine ecology, Fe biogeochemistry, and both human and environmental health.

  2. Extract from the fermented soybean product Natto inhibits Vibrio biofilm formation and reduces shrimp mortality from Vibrio harveyi infection.

    Science.gov (United States)

    Yatip, Pattanan; Nitin Chandra Teja, D; Flegel, Timothy W; Soowannayan, Chumporn

    2018-01-01

    Many bacteria, including Vibrio pathogens of shrimp, need to colonize and/or form biofilms in hosts or the environment to cause disease. Thus, one possible control strategy for shrimp Vibriosis is biofilm inhibition. With this objective, an extract from the Japanese fermented soybean product, Natto was tested with the luminescent shrimp pathogen Vibrio harveyi (VH) for its ability to inhibit or degrade biofilm and to interfere with cell growth in broth. Natto is a traditional fermentation product of Bacillus subtilis var Natto (BSN1). Using 96 well microtiter plates coated with 0.4% chitosan, we found that biofilm formation by VH was inhibited, while growth in parallel broth cultures was not. When an extract from Natto prepared using BSN1 was mixed with feed for the whiteleg shrimp Penaeus vannamei before immersion challenge with V. harveyi at 10 6  cfu/ml, survival was significantly higher (p≤0.05) than for control shrimp given feed without these additives. Further work done to test whether d-amino acids were involved in biofilm formation as previously reported for B. subtilis, Staphylococus aureus and Pseudomonas aeruginosa gave negative results. In conclusion, we discovered that Natto extract can inhibit Vibrio biofilm formation and that it or BSN1 alone added to shrimp feed can significantly reduce shrimp mortality in immersion challenges with pathogenic VH. This shows some promise for possible application against Vibriosis in shrimp since Natto is generally regarded as safe (GRAS) for human consumption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. APETALA 2-domain-containing transcription factors: focusing on abscisic acid and gibberellins antagonism.

    Science.gov (United States)

    Shu, Kai; Zhou, Wenguan; Yang, Wenyu

    2018-02-01

    The phytohormones abscisic acid (ABA) and gibberellin (GA) antagonistically mediate diverse plant developmental processes including seed dormancy and germination, root development, and flowering time control, and thus the optimal balance between ABA and GA is essential for plant growth and development. Although more than a half and one century have passed since the initial discoveries of ABA and GA, respectively, the precise mechanisms underlying ABA-GA antagonism still need further investigation. Emerging evidence indicates that two APETALA 2 (AP2)-domain-containing transcription factors (ATFs), ABI4 in Arabidopsis and OsAP2-39 in rice, play key roles in ABA and GA antagonism. These two transcription factors precisely regulate the transcription pattern of ABA and GA biosynthesis or inactivation genes, mediating ABA and GA levels. In this Viewpoint article, we try to shed light on the effects of ATFs on ABA-GA antagonism, and summarize the overlapping but distinct biological functions of these ATFs in the antagonism between ABA and GA. Finally, we strongly propose that further research is needed into the detailed roles of additional numerous ATFs in ABA and GA crosstalk, which will improve our understanding of the antagonism between these two phytohormones. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  4. Antagonism of morphine-induced central respiratory depression by donepezil in the anesthetized rabbit

    Directory of Open Access Journals (Sweden)

    MIKI TSUJITA

    2007-01-01

    Full Text Available Morphine is often used in cancer pain and postoperative analgesic management but induces respiratory depression. Therefore, there is an ongoing search for drug candidates that can antagonize morphine-induced respiratory depression but have no effect on morphine-induced analgesia. Acetylcholine is an excitatory neurotransmitter in central respiratory control and physostigmine antagonizes morphine-induced respiratory depression. However, physostigmine has not been applied in clinical practice because it has a short action time, among other characteristics. We therefore asked whether donepezil (a long-acting acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease can antagonize morphine-induced respiratory depression. Using the anesthetized rabbit as our model, we measured phrenic nerve discharge as an index of respiratory rate and amplitude. We compared control indices with discharges after the injection of morphine and after the injection of donepezil. Morphine-induced depression of respiratory rate and respiratory amplitude was partly antagonized by donepezil without any effect on blood pressure and end-tidal C0(2. In the other experiment, apneic threshold PaC0(2 was also compared. Morphine increased the phrenic nerve apnea threshold but this was antagonized by donepezil. These findings indicate that systemically administered donepezil partially restores morphine-induced respiratory depression and morphine-deteriorated phrenic nerve apnea threshold in the anesthetized rabbit

  5. Vibrio Pathogens: A Public Health Concern in Rural Water Resources in Sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Charles A. Osunla

    2017-10-01

    Full Text Available Members of the Vibrio genus are autochthonous inhabitants of aquatic environments and play vital roles in sustaining the aquatic milieu. The genus comprises about 100 species, which are mostly of marine or freshwater origin, and their classification is frequently updated due to the continuous discovery of novel species. The main route of transmission of Vibrio pathogens to man is through drinking of contaminated water and consumption inadequately cooked aquatic food products. In sub-Saharan Africa and much of the developing world, some rural dwellers use freshwater resources such as rivers for domestic activities, bathing, and cultural and religious purposes. This review describes the impact of inadequately treated sewage effluents on the receiving freshwater resources and the associated risk to the rural dwellers that depends on the water. Vibrio infections remain a threat to public health. In the last decade, Vibrio disease outbreaks have created alertness on the personal, economic, and public health uncertainties associated with the impact of contaminated water in the aquatic environment of sub-Saharan Africa. In this review, we carried out an overview of Vibrio pathogens in rural water resources in Sub-Saharan Africa and the implication of Vibrio pathogens on public health. Continuous monitoring of Vibrio pathogens among environmental freshwater and treated effluents is expected to help reduce the risk associated with the early detection of sources of infection, and also aid our understanding of the natural ecology and evolution of Vibrio pathogens.

  6. Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013

    OpenAIRE

    Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

    2014-01-01

    We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ.

  7. Bactericidal effect of lactoferrin and lactoferrin chimera against halophilic Vibrio parahaemolyticus

    NARCIS (Netherlands)

    Leon-Sicairos, N.; Canizalez-Roman, A.; de la Garza, M.; Reyes-Lopez, M.; Zazueta-Beltran, J.; Nazmi, K.; Gomez-Gil, B.; Bolscher, J.G.

    2009-01-01

    Infections caused by Vibrio parahaemolyticus, an halophilic member of the genus Vibrio, have increased globally in the last 5 years. Diarrhea caused by V. parahaemolyticus results from eating raw or undercooked seafood. The aim of this work was to investigate whether lactoferrin and some

  8. Vibrio Pathogens: A Public Health Concern in Rural Water Resources in Sub-Saharan Africa.

    Science.gov (United States)

    Osunla, Charles A; Okoh, Anthony I

    2017-10-07

    Members of the Vibrio genus are autochthonous inhabitants of aquatic environments and play vital roles in sustaining the aquatic milieu. The genus comprises about 100 species, which are mostly of marine or freshwater origin, and their classification is frequently updated due to the continuous discovery of novel species. The main route of transmission of Vibrio pathogens to man is through drinking of contaminated water and consumption inadequately cooked aquatic food products. In sub-Saharan Africa and much of the developing world, some rural dwellers use freshwater resources such as rivers for domestic activities, bathing, and cultural and religious purposes. This review describes the impact of inadequately treated sewage effluents on the receiving freshwater resources and the associated risk to the rural dwellers that depends on the water. Vibrio infections remain a threat to public health. In the last decade, Vibrio disease outbreaks have created alertness on the personal, economic, and public health uncertainties associated with the impact of contaminated water in the aquatic environment of sub-Saharan Africa. In this review, we carried out an overview of Vibrio pathogens in rural water resources in Sub-Saharan Africa and the implication of Vibrio pathogens on public health. Continuous monitoring of Vibrio pathogens among environmental freshwater and treated effluents is expected to help reduce the risk associated with the early detection of sources of infection, and also aid our understanding of the natural ecology and evolution of Vibrio pathogens.

  9. Vibrio Pathogens: A Public Health Concern in Rural Water Resources in Sub-Saharan Africa

    Science.gov (United States)

    Osunla, Charles A.

    2017-01-01

    Members of the Vibrio genus are autochthonous inhabitants of aquatic environments and play vital roles in sustaining the aquatic milieu. The genus comprises about 100 species, which are mostly of marine or freshwater origin, and their classification is frequently updated due to the continuous discovery of novel species. The main route of transmission of Vibrio pathogens to man is through drinking of contaminated water and consumption inadequately cooked aquatic food products. In sub-Saharan Africa and much of the developing world, some rural dwellers use freshwater resources such as rivers for domestic activities, bathing, and cultural and religious purposes. This review describes the impact of inadequately treated sewage effluents on the receiving freshwater resources and the associated risk to the rural dwellers that depends on the water. Vibrio infections remain a threat to public health. In the last decade, Vibrio disease outbreaks have created alertness on the personal, economic, and public health uncertainties associated with the impact of contaminated water in the aquatic environment of sub-Saharan Africa. In this review, we carried out an overview of Vibrio pathogens in rural water resources in Sub-Saharan Africa and the implication of Vibrio pathogens on public health. Continuous monitoring of Vibrio pathogens among environmental freshwater and treated effluents is expected to help reduce the risk associated with the early detection of sources of infection, and also aid our understanding of the natural ecology and evolution of Vibrio pathogens. PMID:28991153

  10. Effects of Pollution on Vibrios in Woji River | Ojesanmi | Journal of ...

    African Journals Online (AJOL)

    The effect of pollution on Vibrio spp. in five sampling stations along Woji River in Port Harcourt was studied in the months of April and November 2010. Vibrio vulnificus, V. parahaemolyticus and V. alginolyticus were isolated. The Plate count technique on Thiosulphate Citrate Bile Salt agar revealed a high population density ...

  11. Genomic diversity of vibrios associated with the Brazilian coral Mussismilia hispida and its sympatric zoanthids (Palythoa caribaeorum, Palythoa variabilis and Zoanthus solanderi).

    Science.gov (United States)

    Chimetto, L A; Brocchi, M; Gondo, M; Thompson, C C; Gomez-Gil, B; Thompson, F L

    2009-06-01

    A taxonomic survey of the vibrios associated with the Brazilian endemic coral Mussismilia hispida and the sympatric zoanthids (i.e. Palythoa caribaeorum, Palythoa variabilis and Zoanthus solanderi). Mucus of 54 cnidarian specimens collected in three different places at São Sebastião in two consecutive years (i.e. 2005 and 2006) was used for taxonomic characterization of the cnidarian microbiota. Ninety-eight of the 151 vibrio isolates fell within the vibrio core group according to partial 16S rDNA sequences. We performed the sequencing of recA and pyrH genes of all vibrio isolates. The most abundant taxa belonged to the vibrio core group (Vibrio harveyi, Vibrio rotiferianus, Vibrio campbellii and Vibrio alginolyticus), Vibrio mediterranei (=Vibrio shillonii) and Vibrio chagasii. With the exception of V. chagasii which was found only in the mucus of M. hispida, the other species appeared in different hosts with no evidence for the presence of host-specific clones or species. Using rep-PCR analysis, we observed a high genomic heterogeneity within the vibrios. Each vibrio isolate generated a different rep-PCR fingerprint pattern. There was a complete agreement between the grouping based on rep-PCR and concatenated sequences of pyrH, recA and 16S rDNA, but the pyrH gene has the highest discriminatory power for vibrio species identification. The vibrio core group is dominant in the mucus of these cnidarians. There is a tremendous diversity of vibrio lineages within the coral mucus. pyrH gene sequences permit a clear-cut identification of vibrios. The taxonomic resolution provided by pyrH (but not recA) appears to be enough for identifying species of vibrios and for disclosing putative new taxa. The vibrio core group appears to be dominant in the mucus of the Brazilian cnidarians. The overrepresentation of these vibrios may reflect as yet unknown ecological functions in the coral holobiont.

  12. Efek Antibakteri Ekstrak Daun Mimba (Azadirachta indica A. Juss terhadap Bakteri Vibrio algynoliticus Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Uli Ayini

    2014-03-01

    Full Text Available Budidaya udang windu di Indonesia telah berkembang pesat. Salah satu kendala budidaya udang adalah penyakit Vibriosis yang disebabkan oleh bakteri Vibrio algynoliticus. Tujuan penelitian ini adalah untuk mengetahui efek antibakeri ekstrak daun mimba terhadap bakteri Vibrio algynoliticus. Penelitian ini menggunakan metode dilusi untuk mengetahui efek antibakteri ekstrak daun mimba terhadap bakteri Vibrio algynoliticus secara in vitro. Konsentrasi ekstrak yang digunakan (% yaitu: 0; 2,5; 5; 7,5; 10; 12,5 dan sebagai kontrol terdiri dari kontrol positif, dan kontrol negatif. Pengumpulan data untuk menentukan MIC (Minimum Inhibitory Concentration dilakukan dengan membandingkan kejernihan kultur di medium TSB 2% pada berbagai konsentrasi yang berbeda, dengan kontrol positif dan kontrol negatif. Penentuan MBC (Minimum Bacterisidal Concentration dilakukan dengan melihat ada tidaknya dan jumlah koloni bakteri Vibrio alginolyticus yang muncul pada medium subkultur TSA 2% setelah inkubasi 24 jam. Hasil penelitian menunjukkan nilai MIC yaitu konsentrasi 5%, hal ini ditunjukkan dengan tabung yang mulai jernih. Nilai MBC ekstrak daun mimba terhadap bakteri Vibrio alginolyticus adalah konsentrasi 12,5% ditandai dengan sudah tidak munculnya  koloni bakteri Vibrio alginolyticus. Berdasarkan penelitian ini dapat disimpulkan bahwa ekstrak daun mimba dapat memberikan efek antibakteri terhadap bakteri Vibrio alginolyticus secara in vitro.Tiger shrimp cultivation in Indonesia has been growing rapidly. The main obstacle is the shrimp farming vibriosis disease caused by the bacterium Vibrio algynoliticus. The aim of this research was to determine the effects of neem leaf extract antibakeri against Vibrio algynoliticus. This study used a dilution method to determine the antibacterial effect of neem leaf extract against Vibrio algynoliticus bacteria in vitro. The concentration of the extract used (%: 0; 2.5; 5; 7.5; 10; 12.5 and as a control consisting of a positive

  13. Vibrios on the half shell: what the walrus and the carpenter didn't know.

    Science.gov (United States)

    Blake, P A

    1983-10-01

    At least nine Vibrio species have been associated with disease in the United States. Vibrio fluvialis, V. hollisae, V. mimicus, and V. parahaemolyticus cause diarrheal diseases, but may also be encountered in extraintestinal infections such as wound and ear infections, septicemia, and cholecystitis. Vibrio alginolyticus, V. damsela, V. metschnikovii, and V. vulnificus primarily cause extraintestinal disease. Toxigenic V. cholerae O1 is the cause of epidemic cholera, whereas nontoxigenic V. cholerae O1 and non-O1 V. cholerae have been associated with both diarrheal and extraintestinal diseases. Most reports of vibrio infections have come from states along the Atlantic Ocean and Gulf of Mexico and from Hawaii, and most of the infections have occurred during summer and fall. Wound and ear infections have occurred after exposure to salty or brackish water or to drippings from raw seafoods. Foodborne vibrio infections are almost all caused by seafoods, especially oysters eaten raw. Thorough cooking and careful handling will render seafoods safe for consumption.

  14. Vibrio parahaemolyticus: A Review on the Pathogenesis, Prevalence and Advance Molecular Identification Techniques

    Directory of Open Access Journals (Sweden)

    Vengadesh eLetchumanan

    2014-12-01

    Full Text Available Vibrio parahaemolyticus is a Gram-negative halophilic bacterium that is found in estuarine, marine and coastal environments. Vibrio parahaemolyticus is the leading causal agent of human acute gastroenteritis following the consumption of raw, undercooked or mishandled marine products. In rare cases, Vibrio parahaemolyticus causes wound infection, ear infection or septicaemia in individuals with pre-existing medical conditions. Vibrio parahaemolyticus has two hemolysins virulence factors that are thermostable direct hemolysin (tdh-a pore-forming protein that contributes to the invasiveness of the bacterium in humans, and TDH-related hemolysin (trh, which plays a similar role as thermostable direct hemolysin (tdh in the disease pathogenesis. In addition, the bacterium is also encodes for adhesions and type III secretion systems (T3SS1 and T3SS2 to ensure its survival in the environment. This review aims at discussing the Vibrio parahemolyticus growth and characteristics, pathogenesis, prevalence and advances in molecular identification techniques.

  15. Unique and conserved genome regions in Vibrio harveyi and related species in comparison with the shrimp pathogen Vibrio harveyi CAIM 1792

    DEFF Research Database (Denmark)

    Valles, Iliana Espinoza; Vora, Gary J; Lin, Baochuan

    2015-01-01

    Vibrio harveyi CAIM 1792 is a marine bacterial strain that causes mortality in farmed shrimp in north-west Mexico, and the identification of virulence genes in this strain is important for understanding its pathogenicity. The aim of this work was to compare the V. harveyi CAIM 1792 genome....... The proteome of CAIM 1792 had higher similarity to those of other V. harveyi strains (78 %) than to those of the other closely related species Vibrio owensii (67 %), Vibrio rotiferianus (63 %) and Vibrio campbellii (59 %). Pan-genome ORFans trees showed the best fit with the accepted phylogeny based on DNA......-DNA hybridization and multi-locus sequence analysis of 11 concatenated housekeeping genes. SNP analysis clustered 34/38 genomes within their accepted species. The pangenomic and SNP trees showed that V. harveyi is the most conserved of the four species studied and V. campbellii may be divided into at least three...

  16. Vibrio ecology in PNW - The Ecology of Vibrio parahaemolyticus in the Pacific Northwest: Implications for risk assessment and early warning systems

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Over the past decade, there has been a significant increase in Vibrio parahaemolyticus-related gastroenteritis from the consumption of raw oysters harvested in...

  17. Temperature-dependent inhibition of opportunistic Vibrio pathogens by native coral commensal bacteria.

    Science.gov (United States)

    Frydenborg, Beck R; Krediet, Cory J; Teplitski, Max; Ritchie, Kim B

    2014-02-01

    Bacteria living within the surface mucus layer of corals compete for nutrients and space. A number of stresses affect the outcome of this competition. The interactions between native microorganisms and opportunistic pathogens largely determine the coral holobiont's overall health and fitness. In this study, we tested the hypothesis that commensal bacteria isolated from the mucus layer of a healthy elkhorn coral, Acropora palmata, are capable of inhibition of opportunistic pathogens, Vibrio shiloi AK1 and Vibrio coralliilyticus. These vibrios are known to cause disease in corals and their virulence is temperature dependent. Elevated temperature (30 °C) increased the cell numbers of one commensal and both Vibrio pathogens in monocultures. We further tested the hypothesis that elevated temperature favors pathogenic organisms by simultaneously increasing the fitness of vibrios and decreasing the fitness of commensals by measuring growth of each species within a co-culture over the course of 1 week. In competition experiments between vibrios and commensals, the proportion of Vibrio spp. increased significantly under elevated temperature. We finished by investigating several temperature-dependent mechanisms that could influence co-culture differences via changes in competitive fitness. The ability of Vibrio spp. to utilize glycoproteins found in A. palmata mucus increased or remained stable when exposed to elevated temperature, while commensals' tended to decrease utilization. In both vibrios and commensals, protease activity increased at 30 °C, while chiA expression increased under elevated temperatures for Vibrio spp. These results provide insight into potential mechanisms through which elevated temperature may select for pathogenic bacterial dominance and lead to disease or a decrease in coral fitness.

  18. Investigation of Vibrio alginolyticus, V. harveyi, and V. parahaemolyticus in large yellow croaker, Pseudosciaena crocea (Richardson reared in Xiangshan Bay, China

    Directory of Open Access Journals (Sweden)

    Lu Liu

    2016-05-01

    Full Text Available Large yellow croaker (LYC, Pseudosciaena crocea is an economically important fish species of mariculture in China. The variation of yearly production of LYC has been increasingly related to the outbreaks of fish diseases. Moreover, Vibrio infections have been identified in this fish frequently. To understand the pattern of Vibrio infections in LYC, we conducted a culture-independent survey of Vibrios in farmed LYC populations using a multiplex PCR method targeting Vibrio alginolyticus, Vibrio harveyi and Vibrio parahaemolyticus. The results showed that three fish pathogenic Vibrios had been detected in LYC populations at each sampling with a prevalence ranging from 6.7% to 73.3% but no single species dominated the Vibrio infection. The findings indicate that three Vibrio species still have impact on health status of farmed LYC and LYC aquaculture requires more efficacious prophylactic strategies. Keywords: Vibrio, Large yellow croaker, Multiplex PCR, Epidemiology

  19. Incidence of Vibrio cholerae and related vibrios in a coastal lagoon and seawater influenced by lake discharges along an annual cycle.

    Science.gov (United States)

    Garay, E; Arnau, A; Amaro, C

    1985-08-01

    Most probable numbers of Vibrio cholerae and related vibrios were determined in Albufera Lake, Valencia, Spain, and in coastal waters under the influence of the lake discharges over the course of an annual cycle. The influence of temperature, kind of water, and characteristics of the different sampling sites on the numbers of vibrios recovered was evaluated. Maximum recovery of vibrios reached 10(3)/ml in both types of waters analyzed. V. cholerae numbers reached 10(3)/ml in the lake and 10(2) in one of the coastal sites. Frequently during the warm season, all vibrios isolated were identified as V. cholerae. Occasionally, no V. cholerae was recovered. The recovery of vibrios was significantly influenced by the temperature of the water and the type of water analyzed. Most of the V. cholerae isolates were included in Heiberg groups I and II, and nearly 50% of the strains used chitin as sole carbon source. Indole was not produced by 100% of the strains. All strains tested were non-O1 serovars.

  20. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

    International Nuclear Information System (INIS)

    Sharma, Anshu; Rawat, Kamla; Solanki, Pratima R; Bohidar, H B; Baral, Dinesh

    2015-01-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe 3 O 4 )) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe 3 O 4 and CA-Fe 3 O 4 /ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe 3 O 4 , CA-Fe 3 O 4 nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe 3 O 4 ) and 189.51 nm (CA-Fe 3 O 4 ) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe 2 O 3 /ITO immunosensor exhibits a good detection range of 12.5–500 ng mL −1 with a low detection limit of 0.32 ng mL −1 , sensitivity 0.03 Ω/ng ml −1 cm −2 , and reproducibility more than 11 times. (paper)

  1. Quorum Sensing Disruption in Vibrio harveyi Bacteria by Clay Materials.

    Science.gov (United States)

    Naik, Sajo P; Scholin, Jonathon; Ching, San; Chi, Fang; Herpfer, Marc

    2018-01-10

    This work describes the use of clay minerals as catalysts for the degradation of quorum sensing molecule N-(3-oxooctanoyl)-dl-homoserine lactone. Certain clay minerals as a result of their surface properties and porosity can catalytically degrade the quorum sensing molecule into smaller fragments. The disruption of quorum sensing by clay in a growing Gram-negative Vibrio harveyi bacteria culture was also studied by monitoring luminescence and population density of the bacteria, wherein quenching of bacterial quorum sensing activity was observed by means of luminescence reduction. The results of this study show that food-grade clays can be used as biocatalysts in disrupting bacterial activity in various media.

  2. Vibrio cholerae Classical Biotype Strains Reveal Distinct Signatures in Mexico

    OpenAIRE

    Alam, Munirul; Islam, M. Tarequl; Rashed, Shah Manzur; Johura, Fatema-tuz; Bhuiyan, Nurul A.; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Hasan, Nur-A; Colwell, Rita R.; Cravioto, Alejandro

    2012-01-01

    Vibrio cholerae O1 classical (CL) biotype caused the fifth and sixth pandemics, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the seventh pandemic in Asia in the 1970s by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia and although it had never been reported from Latin America, V. cholerae CL and ET biotypes, including a hybrid ET, were found associated with areas of cholera endemicity in Mexico between 199...

  3. Environmental determinants of Vibrio parahaemolyticus in the Chesapeake Bay.

    Science.gov (United States)

    Davis, Benjamin J K; Jacobs, John M; Davis, Meghan F; Schwab, Kellogg J; DePaola, Angelo; Curriero, Frank C

    2017-08-25

    Vibrio parahaemolyticus naturally-occurs in brackish and marine waters and is one of the leading causes of seafood-borne illness. Previous work studying the ecology of V. parahaemolyticus is often limited in geographic extent and lacking a full range of environmental measures. This study used a unique, large dataset of surface water samples in the Chesapeake Bay ( n =1,385) collected from 148 monitoring stations from 2007 to 2010. Water was analyzed for over 20 environmental parameters with additional meteorological and surrounding land use data. V. parahaemolyticus -specific genetic markers thermolabile hemolysin ( tlh ), thermostable direct hemolysin ( tdh ), and tdh -related hemolysin ( trh ) were assayed using quantitative PCR (qPCR), and interval-censored regression models with non-linear effects were estimated to account for limits of detection and quantitation. tlh was detected in 19.6% of water samples; tdh or trh markers were not detected. Results confirmed previously reported positive associations for V. parahaemolyticus abundance with temperature and turbidity and negative associations with high salinity (> 10-23‰). Furthermore, the salinity relationship was determined to be a function of both low temperature and turbidity, with an increase of either nullifying the high salinity effect. Associations with dissolved oxygen and phosphate also appeared stronger when samples were taken nearby human developments. Renewed focus on the V. parahaemolyticus ecological paradigm is warranted to protect public health. Importance Vibrio parahaemolyticus is one of the leading causes of seafood-borne illness in the United States and across the globe. Exposure is often through consuming raw or undercooked shellfish. Given the natural presence of the bacterium in the marine environment, improved understanding of its environmental determinants is necessary for future preventative measures. This analysis of environmental Vibrio parahaemolyticus is one of only a few that

  4. Application of Reverse Transcriptase-PCR-DGGE as a rapid method for routine determination of Vibrio spp. in foods.

    Science.gov (United States)

    Chahorm, Kanchana; Prakitchaiwattana, Cheunjit

    2018-01-02

    The aim of this research was to evaluate the feasibility of PCR-DGGE and Reverse Transcriptase-PCR-DGGE techniques for rapid detection of Vibrio species in foods. Primers GC567F and 680R were initially evaluated for amplifying DNA and cDNA of ten references Vibrio species by PCR method. The GC-clamp PCR amplicons were separated according to their sequences by the DGGE using 10% (w/v) polyacrylamide gel containing 45-70% urea and formamide denaturants. Two pair of Vibrio species, which could not be differentiated on the gel, was Vibrio fluvialis - Vibrio furnissii and Vibrio parahaemolyticus - Vibrio harveyi. To determine the detection limit, in the community of 10 reference strains containing the same viable population, distinct DNA bands of 3 species; Vibrio cholerae, Vibrio mimicus and Vibrio alginolyticus were consistently observed by PCR-DGGE technique. In fact, 5 species; Vibrio cholerae, Vibrio mimicus, Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio fluvialis consistently observed by Reverse Transcriptase-PCR-DGGE. In the community containing different viable population increasing from 10 2 to 10 5 CFU/mL, PCR-DGGE analysis only detected the two most prevalent species, while RT-PCR-DGGE detected the five most prevalent species. Therefore, Reverse Transcriptase-PCR-DGGE was also selected for detection of various Vibrio cell conditions, including viable cell (VC), injured cells from frozen cultures (IVC) and injured cells from frozen cultures with pre-enrichment (PIVC). It was found that cDNA band of all cell conditions gave the same migratory patterns, except that multiple cDNA bands of Plesiomonas shigelloides under IVC and PIVC conditions were found. When Reverse Transcriptase-PCR-DGGE was used for detecting Vibrio parahaemolyticus in the pathogen-spiked food samples, Vibrio parahaemolyticus could be detected in the spiked samples containing at least 10 2 CFU/g of this pathogen. The results obtained also corresponded to standard method (USFDA, 2004

  5. Preliminary study of transplanting as a process for reducing levels of Vibrio vulnificus and Vibrio parahaemolyticus in shellstock oysters.

    Science.gov (United States)

    Walton, William C; Nelson, Chris; Hochman, Mona; Schwarz, John

    2013-01-01

    Increasingly strict standards for harvest of oysters for the raw, half-shell market (designated as "white tag") should increase the proportion of oysters not meeting these standards (designated as "green tag"). Transplanting of green tag oysters into highsalinity waters (>20 practical salinity units) was explored as a means of returning Vibrio vulnificus and Vibrio parahaemolyticus levels to levels present on initial harvest. In summer 2011, oysters originally harvested in Louisiana were transplanted on two separate occasions (n = 2) to two sites in Mississippi Sound, AL: Sandy Bay and Dauphin Island. Oysters were tested for V. vulnificus and V. parahaemolyticus densities (by using the U.S. Food and Drug Administration enrichment method) after 2, 7, and 14 days deployed, with baseline samples taken (i) at the time of original harvest and iced, (ii) from oysters refrigerated within 1 h of harvest at oysters not refrigerated during the harvest trip (green tag) but refrigerated after an 8-h trip. White and green tag oysters were sampled ∼24 h on arrival in Bon Secour, AL, put on ice, and shipped for analysis. Among baseline samples, there were no significant differences in V. vulnificus and V. parahaemolyticus densities, although the densities in the green tag oysters tended to be highest. After transplanting, V. vulnificus densities were significantly highest on day 2, with no significant differences among any of the other days within a site. On day 2, Sandy Bay had significantly greater densities of V. vulnificus than the Dauphin Island site, but no other days differed from time zero. For Vibrio parahaemolyticus, densities were greatest on day 2 and lowest at time zero, but this did not differ significantly from abundance on day 14. Average survival was 83.4% (± 3.13 SD), with no differences between sites. These preliminary results indicate that high-salinity transplanting could be an effective method of converting green tag oysters to oysters suitable for

  6. Inactivation of Vibrio parahaemolyticus and Vibrio vulnificus in oysters by high-hydrostatic pressure and mild heat.

    Science.gov (United States)

    Ye, Mu; Huang, Yaoxin; Chen, Haiqiang

    2012-10-01

    Several recent outbreaks associated with oysters have heightened safety concerns of raw shellfish consumptions, with the majority being attributed to Vibrio spp. The objective of this study was to determine the effect of high-hydrostatic pressure (HHP) followed by mild heating on the inactivation of Vibrio parahaemolyticus and Vibrio vulnificus in live oysters. Inoculated oysters were randomly subjected to: a) pressurization at 200-300 MPa for 2 min at 21 °C, b) mild heat treatment at 40, 45 or 50 °C for up to 20 min and c) pressure treatment of 200-300 MPa for 2 min at 21 °C followed by heat treatment at 40-50 °C. Counts of V. parahaemolyticus and V. vulnificus were then determined using the most probable number (MPN) method. Pressurization at 200-300 MPa for 2 min resulted in various degrees of inactivation, from 1.2 to >7 log MPN/g reductions. Heat treatment at 40 and 45 °C for 20 min only reduced V. parahaemolyticus and V. vulnificus by 0.7-2.5 log MPN/g while at 50 °C for 15 min achieved >7 log MPN/g reduction. HHP and mild heat had synergistic effects. Combinations such as HHP at 250 MPa for 2 min followed by heat treatment at 45 °C for 15 min and HHP at 200 MPa for 2 min followed by heat treatment at 50 °C for 5 min reduced both V. parahaemolyticus and V. vulnificus to non-detectable levels by the MPN method (oysters (negative enrichment results). This study demonstrated the efficiency of HHP followed by mild heat treatments on inactivation of V. parahaemolyticus and V. vulnificus and could help the industry to establish parameters for processing oysters. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Antagonism between penicillin and erythromycin against Streptococcus pneumoniae in vitro and in vivo

    DEFF Research Database (Denmark)

    Johansen, H K; Jensen, T G; Dessau, R B

    2000-01-01

    The combination of beta-lactam antibiotics and macrolides is often recommended for the initial empirical treatment of acute pneumonia in order to obtain activity against the most important pathogens. Theoretically, this combination may be inexpedient, as the bacteriostatic agent may antagonize th...

  8. [Antagonism of Trichoderma spp. to fungi caused root rot of Sophora tonkinensis].

    Science.gov (United States)

    Qin, Liu-yan; Jiang, Ni; Tang, Mei-qiong; Miao, Jian-hua; Li, Lin-xuan

    2011-04-01

    To study the antagonism of Trichoderma spp. to fungi S9(Fusarium solani)which caused root rot of Sophora tonkinensis and discuss the further develop prospects of microbial biological control in soil-borne diseases on Chinese herbal medicines. Antagonism of H2 (Trichoderma harsianum), M6 (Trichoderma viride) and K1 (Trichoderma koningii) to Fusarium solani were researched by growth rate and confront culture. And their mechanisms were discussed. H2 and M6 had obvious competitive advantage, the growth rate of which were 1.43-2.72 times and 1.43-1.95 times as S9 respectively. The space competitive advantage of K1 was relatively weak; the growth rate was slower than S9. The antagonism of three species of Trichoderma spp. to S9 was in varying degrees. The antagonism to S9 of M6 and H2 was better,the inhibition rate were 100% and 82.35% respectively, even cultivated S9 for three days in advance. And their inhibition indexes were both reached class I. The inhibition index and inhibition rate of K1 was respectively 46.36% and class IV. The Trichoderma spp. could cause S9 mycelium to appear some phenomenon just like fracture, constriction reduced, digestion, etc. which were observed under the microscope. Trichoderma harsianum and Trichoderma viride showed the further develop prospects in the fight against soil-borne disease on Chinese herbal medicines.

  9. Mutualism and Antagonism: Ecological Interactions Among Bark Beetles, Mite and Fungi

    Science.gov (United States)

    K.D. Klepzig; J.C. Moser; M.J. Lombardero; M.P. Ayres; R.W. Hofstetter; C.J. Walkinshaw

    2001-01-01

    Insect-fungal complexes provide challenging and fascinating systems for the study of biotic interactions between plants. plant pathogens, insect vectors and other associated organisms. The types of interactions among these organisms (mutualism. antagonism. parasitism. phoresy. etc.) are as variable as the range of organisms involved (plants, fungi, insects. mites. etc...

  10. FoxO3A promotes metabolic adaptation to hypoxia by antagonizing Myc function

    OpenAIRE

    Jensen, Kim Steen; Binderup, Tina; Jensen, Klaus Thorleif; Therkelsen, Ib; Borup, Rehannah; Nilsson, Elise; Multhaupt, Hinke; Bouchard, Caroline; Quistorff, Bjørn; Kjær, Andreas; Landberg, Göran; Staller, Peter

    2011-01-01

    This paper characterizes FoxO3A as required for hypoxic suppression of mitochondrial mass, oxygen consumption, and ROS production. Mechanistically, FoxO3A is shown to promote hypoxic cell survival by directly antagonizing c-Myc at nuclear encoded mitochondrial genes.

  11. Isolation, Characterization and Identification of Environmental Bacterial Isolates with Screening for Antagonism Against Three Bacterial Targets

    Science.gov (United States)

    2017-04-01

    ISOLATES WITH SCREENING FOR ANTAGONISM AGAINST THREE BACTERIAL TARGETS 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...Identification of environmental isolates followed the flowchart from “Bergey’s Manual of Determinative Bacteriology” (Holt et al. 1994), which

  12. Vibrios patogênicos em ostras (Crassostrea rhizophorae servidas em restaurantes no Rio de Janeiro: um alerta para a Saúde Pública Pathogenic Vibrios in oysters (Crassostrea rhizophorae served at restaurants in Rio de Janeiro: a public health warning

    Directory of Open Access Journals (Sweden)

    Christiane Soares Pereira

    2007-06-01

    Full Text Available Avaliaram-se 40 amostras de ostras (Crassostrea rhizophorae servidas in natura em 15 restaurantes da Cidade do Rio de Janeiro, a fim de investigar a presença de Vibrio spp. As amostras de ostras foram analisadas e submetidas a enriquecimento em água peptonada alcalina adicionada de 1 e 3% de NaCl, incubadas a 37°C por 24 horas. Em seguida, os cultivos foram semeados em agar tiossulfato citrato bile sacarose e as colônias suspeitas foram submetidas à caracterização bioquímica. Vibrio parahaemolyticus, Vibrio carchariae, Vibrio alginolyticus e Vibrio vulnificus representaram as principais espécies (> 60% isoladas a partir das ostras in natura.Forty oyster samples (Crassostrea rhizophorae served raw in 15 restaurants in the city of Rio de Janeiro were evaluated in order to investigate the presence of Vibrio spp. The oyster samples were analyzed and subjected to enrichment in alkaline peptone water with the addition of 1 and 3% NaCl and incubated at 37°C for 24 hours. Following this, the cultures were seeded onto thiosulfate citrate bile sucrose agar (TCBS and the suspected colonies were subjected to biochemical characterization. Vibrio parahaemolyticus, Vibrio carchariae, Vibrio alginolyticus and Vibrio vulnificus were the main species (> 60% isolated from raw oysters.

  13. Extracellular proteolytic enzymes produced by human pathogenic Vibrio species

    Directory of Open Access Journals (Sweden)

    Shin-Ichi eMiyoshi

    2013-11-01

    Full Text Available Bacteria in the genus Vibrio produce extracellular proteolytic enzymes to obtain nutrients via digestion of various protein substrates. However, the enzymes secreted by human pathogenic species have been documented to modulate the bacterial virulence. Several species including Vibrio cholerae and V. vulnificus are known to produce thermolysin-like metalloproteases termed vibriolysin. The vibriolysin from V. vulnificus, a causative agent of serious systemic infection, is a major toxic factor eliciting the secondary skin damage characterized by formation of the hemorrhagic brae. The vibriolysin from intestinal pathogens may play indirect roles in pathogenicity because it can activate protein toxins and hemagglutinin by the limited proteolysis and can affect the bacterial attachment to or detachment from the intestinal surface by degradation of the mucus layer. Two species causing wound infections, V. alginolyticus and V. parahaemolyticus, produce another metalloproteases so-called collagenases. Although the detailed pathological roles have not been studied, the collagenase is potent to accelerate the bacterial dissemination through digestion of the protein components of the extracellular matrix. Some species produce cymotrypsin-like serine proteases, which may also affect the bacterial virulence potential. The intestinal pathogens produce sufficient amounts of the metalloprotease at the small intestinal temperature; however, the metalloprotease production by extra-intestinal pathogens is much higher around the body surface temperature. On the other hand, the serine protease is expressed only in the absence of the metalloprotease.

  14. Identification and Initial Characterization of Prophages in Vibrio campbellii.

    Directory of Open Access Journals (Sweden)

    Nicola Lorenz

    Full Text Available Phages are bacteria targeting viruses and represent the most abundant biological entities on earth. Marine environments are exceptionally rich in bacteriophages, harboring a total of 4x1030 viruses. Nevertheless, marine phages remain poorly characterized. Here we describe the identification of intact prophage sequences in the genome of the marine γ-proteobacterium Vibrio campbellii ATCC BAA-1116 (formerly known as V. harveyi ATCC BAA-1116, which presumably belong to the family of Myoviridae. One prophage was found on chromosome I and shows significant similarities to the previously identified phage ΦHAP-1. The second prophage region is located on chromosome II and is related to Vibrio phage kappa. Exposure of V. campbellii to mitomycin C induced the lytic cycle of two morphologically distinct phages and, as expected, extracellular DNA from induced cultures was found to be specifically enriched for the sequences previously identified as prophage regions. Heat stress (50°C, 30 min was also found to induce phage release in V. campbellii. Notably, promoter activity of two representative phage genes indicated heterogeneous phage induction within the population.

  15. Antibiotic Resistance of Vibrio cholerae Isolates from Kashan, Iran

    Directory of Open Access Journals (Sweden)

    Afzali H.MD,

    2016-03-01

    Full Text Available Abstract Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5% and 18 water samples (7.6% were positive for Vibrio cholerae. Non-agglutinating (Nag isolates (75.4% were more common than serotype Inaba (13.2% and Ogawa (11.4%. Nag serotypes were mostly resistant to cefixime (44% and ampicillin (33%. In contaminated water samples also the most frequent cases were Nag serotype (50%. Nag serotype showed 22.2% of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes.

  16. Effect of organic acids on shrimp pathogen, Vibrio harveyi.

    Science.gov (United States)

    Mine, Saori; Boopathy, Raj

    2011-07-01

    Shrimp farming accounts for more than 40% of the world shrimp production. Luminous vibriosis is a shrimp disease that causes major economic losses in the shrimp industry as a result of massive shrimp kills due to infection. Some farms in the South Asia use antibiotics to control Vibrio harveyi, a responsible pathogen for luminous vibriosis. However, the antibiotic-resistant strain was found recently in many shrimp farms, which makes it necessary to develop alternative pathogen control methods. Short-chain fatty acids are metabolic products of organisms, and they have been used as food preservatives for a long time. Organic acids are also commonly added in feeds in animal husbandry, but not in aquaculture. In this study, growth inhibitory effects of short-chain fatty acids, namely formic acid, acetic acid, propionic acid, and butyric acid, on V. harveyi were investigated. Among four acids, formic acid showed the strongest inhibitory effect followed by acetic acid, propionic acid, and butyric acid. The minimum inhibitory concentration (MIC) of 0.035% formic acid suppressed growth of V. harveyi. The major inhibitory mechanism seems to be the pH effect of organic acids. The effective concentration 50 (EC50) values at 96 h inoculation for all organic acids were determined to be 0.023, 0.041, 0.03, and 0.066% for formic, acetic, propionic, and butyric acid, respectively. The laboratory study results are encouraging to formulate shrimp feeds with organic acids to control vibrio infection in shrimp aquaculture farms.

  17. Quorum sensing negatively regulates chitinase in Vibrio harveyi.

    Science.gov (United States)

    Defoirdt, Tom; Darshanee Ruwandeepika, H A; Karunasagar, Indrani; Boon, Nico; Bossier, Peter

    2010-02-01

    Quorum sensing, bacterial cell-to-cell communication, regulates the virulence of Vibrio harveyi towards different hosts. Chitinase can be considered as a virulence factor because it helps pathogenic bacteria to attach to the host and to penetrate its tissues (e.g. in case of shrimp). Here, we show that quorum sensing negatively regulates chitinase in V. harveyi. Chitinolytic activity towards natural chitin from crab shells, the synthetic chitin derivative chitin azure, and fluorogenic chitin oligomers was significantly higher in a mutant in which the quorum-sensing system is completely inactivated when compared with a mutant in which the system is maximally active. Furthermore, the addition of signal molecule containing cell-free culture fluids decreased chitinase activity in a Harveyi Autoinducer 1 and Autoinducer 2-deficient double mutant. Finally, chitinase A mRNA levels were fivefold lower in the mutant in which the quorum-sensing system is maximally active when compared with the mutant in which the system is completely inactivated. [Correction added on 25 September 2009, after first online publication: the preceding sentence was corrected from 'Finally, chitinase A mRNA levels were fivefold lower in the mutant in which the quorum-sensing system is completely inactivated when compared with the mutant in which the system is maximally active.'] We argue that this regulation might help the vibrios to switch between host-associated and free-living life styles. © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.

  18. Vibrio harveyi effect under survival of Litopenaeus vannamei larvae

    Directory of Open Access Journals (Sweden)

    Gabriel Aguirre-Guzmán

    2013-06-01

    Full Text Available The culture of aquatic organisms show a high relevance in the human feeding and the culture activities can create artificial conditions that increase the growth and selection of specific bacteria. Vibrio species are normal bacteria’s from microflora of penaeid shrimp, those are opportunistic pathogens that can take advantage of the ecological changes generated for the culture of aquatic organisms and which may cause diseases, low survival and economic losses in the shrimp production. The aim of this research was to determine the variation in the survival of different larval substages (nauplius, zoea I-III, mysis I-III and postlarvae 1, of Pacific white shrimp Litopenaeus vannamei exposed at three doses [103 , 105 , and 107 colony-forming unit (CFU ml-1 [ of V. harveyi, by immersion (30 min as infection method. This species generated a significant low survival in larvae (p < 0.05 only in high doses (105 and 107 CFU ml-1 , where higher doses show the lowest values of survival. Larval substages and postlarvae 1 of shrimp showed sensitivity associate to the increase of Vibrio doses and this sensitivity decreased with the growth of larval substages and postlarvae 1. This information has high significance for the fisheries and aquaculture industry, which help to generate strategies to reduce the effects of V. harveyi with positive effect in growth and survival of the shrimp larvae and postlarvae 1.

  19. Simulated hatchery system to assess bacteriophage efficacy against Vibrio harveyi.

    Science.gov (United States)

    Raghu Patil, J; Desai, Srividya Narayanamurthy; Roy, Panchali; Durgaiah, Murali; Saravanan, R Sanjeev; Vipra, Aradhana

    2014-12-02

    Vibriosis caused by luminous Vibrio harveyi commonly contributes to poor survival in shrimp hatcheries and aquaculture ponds. Lytic bacteriophages pathogenic for V. harveyi are currently being investigated as an alternative to antibiotics to prevent vibriosis. Here, 8 bacteriophages were isolated from oysters and clams using V. harveyi strains as baiting hosts. Among these bacteriophages, 1 strain (VHP6b) identified as broadly pathogenic for 27 V. harveyi strains examined was further characterized by electron microscopy and genome sequence analysis. Phage VHP6b possessed a tail and morphology consistent with it being a member of the family Siphoviridae, and its genome and proteome were most closely related to the Vibrio phages SSP02 and MAR10. An integrase gene essential for lysogeny was not evident. The ability of bacteriophage VHP6b to protect shrimp postlarvae against vibriosis caused by V. harveyi strain VH6 was demonstrated in a model system designed to simulate typical hatchery conditions. Bacteriophage treatment improved survival of postlarvae by 40 to 60% under these conditions, so therapies based on this or other bacteriophages may be useful in shrimp hatcheries.

  20. Antimicrobial effect of dietary oregano essential oil against Vibrio bacteria in shrimps

    Directory of Open Access Journals (Sweden)

    Gracia-Valenzuela M.H.

    2014-01-01

    Full Text Available The effect of dietary oregano essential oils on the growth of Vibrio bacteria in shrimps was evaluated. Shrimps were fed: (i food with oregano oil with a high level of thymol; (ii food with oregano oil with a high level of carvacrol, and (iii food without oregano oil (the control. The animals were infected by three species of Vibrio (vulnificus, parahaemolyticus and cholerae. The microbial counts of Vibrio species were significantly lower (p <0.05 in tissues from animals whose food was supplemented with oregano oil. We concluded that dietary supplementation of shrimps with oregano oil provides antimicrobial activity into the body of the penaeids.

  1. Detection of Vibrio harveyi using hemolysin primer in tiger shrimp Penaeus monodon

    Directory of Open Access Journals (Sweden)

    Irma Suriyani

    2015-05-01

    Full Text Available ABSTRACT This study was aimed to analyze the sensitivity and ability of primer hemolysin in detecting pathogenetic Vibrio on tiger shrimp post-larvae (PL exposed under different exposure times in media inoculated with Vibrio harveyi. The PL of tiger shrimp were infected with 106 cfu/mL of V. harveyi by immersion method for three, six, 12, 24, 48 and 72 hours. The presence of hemolisin genes was detected by PCR techniques. The electrophoresis detected narrow hemolysin genes after PL were exposed for three and six hours. Clear visible bands of DNA Vibrio were observed for 12 hours of exposure. In contrast, no detected hemolysin gene of Vibrio was observed for PL exposed within 24, 48, and 72 hours. The rapid detection on Vibrio pathogenic for tiger shrimp PL should be conducted within three to 12 hours of exposure. No recommendation in utilizing this rapid detection for tiger shrimp PL exposed beyond 12 hours of V. harveyi. Keywords: specific primer, luminous Vibrio bacteria, pathogenic, PCR method, hemolysin gene  ABSTRAK Penelitian ini bertujuan untuk mengetahui kemampuan atau sensitivitas primer hemolisin dalam mendeteksi Vibrio patogen dengan lama pemaparan berbeda. Penelitian ini dilakukan dengan menginfeksikan Vibrio harveyi pada benur udang dengan metode perendaman pada konsentrasi 106 cfu/mL. Pengambilan sampel dilakukan pada waktu tiga, enam, 12, 24, 48, dan 72 jam pascainfeksi. Keberadaan gen hemolisin pada bakteri V. harveyi dideteksi menggunakan teknik polymerase chain reaction (PCR. Hasil elektroforesis memperlihatkan bahwa pada pemaparan tiga dan enam jam keberadaan gen hemolisin dari bakteri Vibrio patogen yang diinfeksikan sudah dapat terdeteksi pada benur walaupun masih terlihat tipis. Pada pemaparan 12 jam terlihat sangat jelas pita-pita DNA dari bakteri patogen. Sedangkan pada pemaparan 24, 48, dan 72 jam sudah tidak terdeteksi lagi gen hemolisin dari bakteri Vibrio. Hal ini diduga disebabkan terjadinya penurunan populasi

  2. Antagonistic Activities of Purple Non-sulfur Bacterial Extracts Against Antibiotic Resistant Vibrio sp.

    Directory of Open Access Journals (Sweden)

    Chandrasekaran, R.

    2011-01-01

    Full Text Available Solvent extracts of native purple non-sulfur bacterial (PNSB isolates from the effluents of brackish shrimp culture ponds, near Nagapattinam coast (South India were evaluated for antibacterial activity by the disc diffusion method. Best results were shown by the chloroform extracts against oxytetracycline resistant Vibrio harveyi and Vibrio fischerii. Among the purple non-sulfur bacterial isolates, Rhodobacter sphaeroides, showed maximum antagonistic activity. The findings suggest that the antagonistic extracts from Rba. sphaeroides could be used as an effective antibiotic in controlling Vibrio spp., in aquaculture systems.

  3. Aspects of vibrio parahaemolyticus(SAK) in fish preservation by irradiation 1. The presence of vibrio parahaemolyticus(SAK) in coastal areas of Sumatra and Java

    International Nuclear Information System (INIS)

    Suhadi, F.

    1984-01-01

    A study was carried out on the presence of vibrio parahaemolyticus in samples of sediment and seafoods originating from the eastern coast of Sumatra and the north coastal areas of Java. In a total of 2.434 samples of sediment and seafoods, 79 (3,3%) were found to contain vibrio parahaemolyticus. Among the 467 sediment samples, 1.650 fish, 133 shellfish, 123 shrimps, and 61 crab samples, 22 (4.7%), 41 (2.5%), 12 (9.0%), 2 (1,6%) and 2 (3.3%) were positive for vibrio parahaemolyticus, respectively. Based on the sampling areas, the high incidence of vibrio parahaemolyticus was found in samples collected from Riau (5.4%), while the samples from East Java was only about 0.4%. The contamination level of vibrio parahaemolyticus in samples collected from coastal areas of Sumatra and Java is relatively lower compared with the data obtained from some other coastal areas in the United States and Japan. (author)

  4. Structural organization of the transfer RNA operon I of Vibrio cholerae

    Indian Academy of Sciences (India)

    Unknown

    [Ghatak A, Majumdar A and Ghosh R K 2005 Structural organization of the transfer RNA operon I of Vibrio cholerae: Differences ..... clonal relationship are of utmost importance. ... rately derived from environmental, nontoxigenic, non-O1.

  5. Uptake of Vibrio cholerae biotype eltor from contaminated water by water hyacinth (eichornia crassipes).

    Science.gov (United States)

    Spira, W M; Huq, A; Ahmed, Q S; Saeed, Y A

    1981-09-01

    Vibrio cholerae biotype eltor appears to concentrate on the surface of the water hyacinth (Eichornia crassipes), thereby enhancing its survival and its potential for transmission through waterways of cholera-endemic regions such as Bangladesh.

  6. Uptake of Vibrio cholerae Biotype eltor from Contaminated Water by Water Hyacinth (Eichornia crassipes)

    OpenAIRE

    Spira, William M.; Huq, Anwarul; Ahmed, Qazi Shafi; Saeed, Yusuf A.

    1981-01-01

    Vibrio cholerae biotype eltor appears to concentrate on the surface of the water hyacinth (Eichornia crassipes), thereby enhancing its survival and its potential for transmission through waterways of cholera-endemic regions such as Bangladesh.

  7. Risk assessment of Vibrio parahaemolyticus in seafood: interpretative summary and technical report

    National Research Council Canada - National Science Library

    2011-01-01

    "Vibrio parahaemolyticus are common causes of diarrhoeal disease worldwide. These marine micro-organisms, native in estuarine waters globally, concentrate in the gut of filter-feeding molluscan shellfish, such as oysters, clams and mussels...

  8. Corrosion of mild steel and stainless steel by marine Vibrio sp.

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Wagh, A.B.

    Microbially induced corrosion (MIC) of stainless steel and mild steel coupons exposed to media with and without a bacterial culture Vibrio sp. was studied using Scanning Electron Microscope (SEM). Pitting type of corrosion was noticed which was more...

  9. INFLUENCE OF SEASONAL FACTORS ON OYSTER HEMOCYTE KILLING OF VIBRIO PARAHEMOLYTICUS

    Science.gov (United States)

    Seasonal variation of cellular defenses of oyster Crassostrea virginica against Vibrio parahaemolyticus were examined from June 1997 to December 1998 using a recently developed bactericidal assay that utilizes a tetrazolium dye. Mean hemocyte numbers, plasma lysozyme, and P. mari...

  10. DIFFERENTIAL EFFECTS OF OYSTER (CRASSOSTREA VIRGINICA) DEFENSES ON CLINICAL AND ENVIRONMENTAL ISOLATES OF VIBRIO PARAHEMOLYTICUS

    Science.gov (United States)

    Three clinical (2030, 2062, and 2107) and three environmental (1094, 1163, and ATCC 17802) isolates of Vibrio parahaemolyticus were exposed to hemocytes and plasma collected from oysters (Crassostrea virginica) to determine their susceptibility to putative oyster defenses. Clinic...

  11. Microbiota of Vibrio sp. in the hepatopancreas of cultured white pacific shrimp (Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Renata Albuquerque C.

    2013-08-01

    Full Text Available Objective. The present study aimed to investigate the presence of vibrios in the hepatopancreas of cultured shrimp. Materials and methods. Vibrios from the hepatopancreas of fifteen samples of five specimens each, of apparently healthy Pacific white shrimp (Litopenaeus vannamei were isolated, identified and quantified. Results. The vibrio density ranged from 430 to 2,400 MPN g-1 (rs MPN cm-1=-0.114; rs MPN g-1 = 0.211. Thirty isolations were obtained, most of which belonged to the species V. cholerae (n=11 and V. parahaemolyticus (n=7. Conclusions. The outcomes of the present study suggest that, even in the absence of symptoms of vibriosis, the microbiota of the hepatopancreas of cultured shrimp may include sucrose positive and negative vibrios.

  12. [Environmental drivers of emergence and spreading of Vibrio epidemics in South America].

    Science.gov (United States)

    Gavilán, Ronnie G; Martínez-Urtaza, Jaime

    2011-03-01

    Vibrio cholerae and V. parahaemolyticus are the two Vibrio species with a major impact on human health. Diseases caused by both pathogens are acquiring increasing relevance due to their expansion at global scale. In this paper, we resume the ecological aspects associated with the arrival and spreading of infections caused by V. parahaemolyticus and V. cholerae in Peru from a South American perspective. Moreover, we discuss the similarities in the emergence in Peru of cholera cases in 1991 and V. parahaemolyticus infections in 1997. These constituted exceptional experiments to evaluate the relationships between the Vibrio epidemics and changes in the environment. The epidemic radiations of V. cholerae and V. parahaemolyticus constitute to clear examples supporting the oceanic dispersion of pathogenic vibrios and have enabled the identification of El Niño events as a potential mechanism for the spreading of diseases through the ocean.

  13. Experimental Reservoirs of Human Pathogens: The Vibrio Cholerae Paradigm (7th Annual SFAF Meeting, 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Colwell, Rita

    2012-06-01

    Rita Colwell on "Experimental Reservoirs of Human Pathogens: The Vibrio cholerae paradigm" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  14. Antibiotic resistance monitoring in Vibrio spp. isolated from rearing environment and intestines of abalone Haliotis diversicolor.

    Science.gov (United States)

    Wang, R X; Wang, J Y; Sun, Y C; B L Yang; A L Wang

    2015-12-30

    546 Vibrio isolates from rearing seawater (292 strains) and intestines of abalone (254 strains) were tested to ten antibiotics using Kirby-Bauer diffusion method. Resistant rates of abalone-derived Vibrio isolates to chloramphenicol (C), enrofloxacin (ENX) and norfloxacin (NOR) were 40%) to kanamycin (KNA), furazolidone (F), tetracycline (TE), gentamicin (GM) and rifampin (RA). 332 isolates from seawater (n=258) and abalone (n=74) were resistant to more than three antibiotics. Peaked resistant rates of seawater-derived isolates to multiple antibiotics were overlapped in May and August. Statistical analysis showed that pH had an important effect on resistant rates of abalone-derived Vibrio isolates to RA, NOR, and ENX. Salinity and dissolved oxygen were negatively correlated with resistant rates of seawater-derived Vibrio isolates to KNA, RA, and PG. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013.

    Science.gov (United States)

    Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

    2014-10-30

    We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ. Copyright © 2014 Díaz-Quiñonez et al.

  16. Vibrio harveyi modulated gene expression in Penaeus monodon and Fenneropenaeus indicus

    Digital Repository Service at National Institute of Oceanography (India)

    Nayak, S.

    : Gammaproteobacteria Order : Vibrionales Family : Vibrionaceae Genus : Vibrio Species : harveyi Vibrio harveyi is a Gram-negative bioluminescent marine bacterium. It is both a free- living, as well as a symbiont with many... marine animals. In free-living form, it can be found throughout the water column, in the sediment as well as on the exterior surfaces of marine organisms. It causes systemic infection resulting in mortalities in larvae and post-larvae, which sometimes...

  17. Prevalence and diversity of Aeromonas and Vibrio spp. in coastal waters of Southern Italy

    DEFF Research Database (Denmark)

    Dumontet, S.; Krovacek, K.; Svenson, S.B.

    2000-01-01

    % of samples were positive for Vibrio spp. It was interesting to note that 38% of the positive stations for both Aeromonas and Vibrio spp. showed a fecal coliform contamination of water at ... coliforms) do not always satisfactorily reflect the hygienic quality of water. The presence of Vibrionaceae on copepods was also investigated. Copepods were sampled at a station located inside the harbour of the city of Naples and were found contaminated by V. cholerae non-Ol, V. alginolyticus, V. fluvialis...

  18. Potensi Ekstrak Daun Binahong (Anredera cordifolia) Sebagai Penghambat Bakteri Vibrio harveyi

    OpenAIRE

    Gde Raka Angga Kartika; Sri Andayani; Soelistyowati Soelistyowati

    2016-01-01

    Binahong (Anredera cordifolia) is a plant that can treat various kinds of diseases, because this plant has a high antioxidant content and as an antibacterial and antiviral. Vibriosis disease caused by the bacterium Vibrio harveyi is a serious problem in marine and brackish culture, this disease can cause death for shrimp and fish that farmed in marine or brackish. This study aims to determine the potential of using leaf extract Binahong with different concentrations as Vibrio harveyi inhibiti...

  19. Molecular variations in Vibrio alginolyticus and V. harveyi in shrimp-farming systems upon stress

    OpenAIRE

    Santhyia,Anix Vivek; Mulloorpeedikayil,Rosalind George; Kollanoor,Riji John; Jeyaseelan,Prince M.J.

    2015-01-01

    A study was performed to investigate the genomic variations in the shrimp farm isolates of Vibrio alginolyticus and V. harveyi when the isolates were subjected to environmental stress. Samples of shrimps, water and sediment were collected from Southern Indian coastal shrimp farms. Vibrio isolates were biochemically identified and confirmed using 16S rDNA and gyrB gene specific PCR. The bacterial strains were genotyped by PCR fingerprinting using GTG(5) and IS (Insertion Sequence) primers. Sev...

  20. Prevalence and Antimicrobial Resistance of Vibrio spp. in Retail and Farm Shrimps in Ecuador.

    Science.gov (United States)

    Sperling, L; Alter, T; Huehn, S

    2015-11-01

    The aim of this study was to investigate the prevalence of Vibrio spp. in shrimp at retail and in shrimp farms in Ecuador and to determine the antimicrobial agent resistance patterns of farm isolates. The presence of genes linked to early mortality syndrome (EMS) or acute hepatopancreatic necrosis disease (AHPND) also was evaluated. Vibrio spp. were isolated from retail shrimps in Cuenca, Ecuador, and farm shrimps originating from provinces El Oro and Guayas, Ecuador. A total of 229 shrimp samples were collected, of which 71 originated from retail markets in Cuenca and 158 came from shrimp farms. Overall, 219 (95.6%) samples tested positive for Vibrio spp. Vibrio parahaemolyticus (80.8%) was the most common species detected, followed by Vibrio alginolyticus (50.2%), Vibrio cholerae (11.3%), and Vibrio vulnificus (3.5%). None of the V. parahaemolyticus isolates carried the virulence-associated tdh and trh genes. In V. parahaemolyticus shrimp farm isolates, high resistance was found to ampicillin (92.2%), and intermediate resistance was found to tetracycline (51.3%) and amikacin (22.1%). Of the V. parahaemolyticus strains, 68 were resistant to at least three antimicrobial agents, and 2 were resistant to seven antimicrobial agents simultaneously. Up to 18 resistant isolates were found for V. alginolyticus, whereas V. vulnificus and V. cholerae isolates were more susceptible. None of the V. parahaemolyticus isolates carried the EMS-AHPND plasmid. The results of this study revealed the ubiquitous occurrence of Vibrio spp. in shrimps at retail and on shrimp farms in Ecuador.

  1. [Factors of persistence and (or) pathogenicity in vibrios and aeromonads belonging to different ecotopes].

    Science.gov (United States)

    Bukharin, O V; Boĭko, A V; Zhuravleva, L A

    1998-01-01

    Factors of persistence and/or pathogenicity in Vibrio parahaemolyticus and Aeromonas hydrophila (hemolytic, lipase, lecithin, DNAase, RNAase, antilysozyme, "anti-interferon", anticomplementary activities and capacity for absorbing Congo red) were studied. The study revealed the interspecific and subpopulation (hospital and extraorganismal parts of the population) differences in the activity of the manifestation of these factors. Strong dependence of the whole complex of persistence and pathogenicity factors of their belonging to the hostal part of Vibrio and Aeromonas populations was shown.

  2. Natural transformation of Vibrio parahaemolyticus: A rapid method to create genetic deletions.

    Science.gov (United States)

    Chimalapati, Suneeta; de Souza Santos, Marcela; Servage, Kelly; De Nisco, Nicole J; Dalia, Ankur B; Orth, Kim

    2018-03-19

    The Gram-negative bacterium Vibrio parahaemolyticus is an opportunistic human pathogen and the leading cause of seafood borne acute gastroenteritis worldwide. Recently, this bacterium was implicated as the etiologic agent of a severe shrimp disease with consequent devastating outcomes to shrimp farming. In both cases, acquisition of genetic material via horizontal transfer provided V. parahaemolyticus with new virulence tools to cause disease. Dissecting the molecular mechanisms of V. parahaemolyticus pathogenesis often requires manipulating its genome. Classically, genetic deletions in V. parahaemolyticus are performed using a laborious, lengthy, multi-step process. Herein, we describe a fast and efficient method to edit this bacterium's genome based on V. parahaemolyticus natural competence. Although this method is similar to one previously described, V. parahaemolyticus requires counter selection for curing of acquired plasmids due to its recalcitrant nature of retaining extrachromosomal DNA. We believe this approach will be of use to the Vibrio community. Importance Spreading of Vibrios throughout the world correlates with increased global temperatures. As they spread, they find new niches to survive, proliferate and invade. Therefore, genetic manipulation of Vibrios is of utmost importance for studying these species. Herein, we have delineated and validated a rapid method to create genetic deletions in Vibrio parahaemolyticus This study provides insightful methodology for studies with other Vibrio species. Copyright © 2018 American Society for Microbiology.

  3. Prevalence of potentially pathogenic Vibrio species in the seafood marketed in Malaysia.

    Science.gov (United States)

    Elhadi, Nasreldin; Radu, Son; Chen, Chien-Hsien; Nishibuchi, Mitsuaki

    2004-07-01

    Seafood samples obtained in seafood markets and supermarkets at 11 sites selected from four states in Malaysia were examined for the presence of nine potentially pathogenic species from the genus Vibrio between July 1998 and June 1999. We examined 768 sample sets that included shrimp, squid, crab, cockles, and mussels. We extensively examined shrimp samples from Selangor State to determine seasonal variation of Vibrio populations. Eight potentially pathogenic Vibrio species were detected, with overall incidence in the samples at 4.6% for V. cholerae, 4.7% for V. parahaemolyticus, 6.0% for V. vulnificus, 11% for V. alginolyticus, 9.9% for V. metschnikovii, 1.3% for V. mimicus, 13% for V. damsela, 7.6% for V. fluvialis, and 52% for a combined population of all of the above. As many as eight Vibrio species were detected in shrimp and only four in squid and peel mussels. The overall percent incidence of any of the eight vibrios was highest (82%) in cockles (Anadara granosa) among the seafoods examined and was highest (100%) in Kuching, Sarawak State, and lowest (25%) in Penang, Pulau Penang State, among the sampling sites. Of 97 strains of V. cholerae isolated, one strain belonged to the O1 serotype and 14 to the O139 serotype. The results indicate that the various seafood markets in Malaysia are contaminated with potentially pathogenic Vibrio species regardless of the season and suggest that there is a need for adequate consumer protection measures.

  4. Vibrio rotiferianus sp. nov., isolated from cultures of the rotifer Brachionus plicatilis.

    Science.gov (United States)

    Gomez-Gil, B; Thompson, F L; Thompson, C C; Swings, J

    2003-01-01

    Five Gram-negative bacterial strains, oxidase-positive, motile by means of more than one polar flagella, facultative anaerobe, arginine dihydrolase-negative, lysine- and omithine decarboxylase-positive, sensitive to the vibriostatic agent O/129, were isolated from a flow-through rotifer culture system in Gent, Belgium, and previously characterized by fluorescent amplified fragment length polymorphism. Comparison of the 16S rDNA sequence of strain LMG 21460T indicated close relationships (approximately 99% similarity) to Vibrio campbellii, Vibrio harveyi, Vibrio alginolyticus and Vibrio parahaemolyticus. However, DNA hybridization experiments revealed similarity values below 70% with its closest species V. campbellii and V. harveyi. Additionally, the analysed strains differ from related Vibrio species by the utilization of melibiose and production of acid from L-arabinose and amygdalin. Among the strains analysed, differences were observed in some phenotypic characters, particularly susceptibility to ampicillin, polymyxin B and amikacin, and urease activity. The major fatty acids identified were 16:0, 18:1 omega7c, 14:0, 12:0 3-OH and 18:0. Vibrio rotiferianus sp. nov. is proposed, with type strain LMG 21460T (=CAIM 577T); it has a DNA G+C content of 44.5 +/- 0.01 mol%.

  5. Prevalence of listeria, Aeromonas, and Vibrio species in fish used for human consumption in Turkey.

    Science.gov (United States)

    Yücel, Nihal; Balci, Senay

    2010-02-01

    A total of 78 raw retail fish samples from 30 freshwater and 48 marine fish were examined for the presence of Listeria, Aeromonas, and Vibrio species. The overall incidence of Listeria spp. was 30% in freshwater samples and 10.4% in marine fish samples. Listeria monocytogenes (44.5%) was the most commonly isolated species in freshwater fish, and Listeria murrayi (83.5%) was the most commonly isolated species in marine fish samples. Motile aeromonads were more common in marine fish samples (93.7%) than in freshwater fish samples (10%). Vibrio alginolyticus, Vibrio fluvialis, and Vibrio damsela were isolated only in marine fish samples, representing 40.9, 38.6, and 36.3% of Vibrio isolates, respectively. In freshwater and marine fish, the highest incidences of Listeria and Aeromonas were found in skin samples; the highest incidence of Vibrio in marine fish was found in gill samples. The location of Listeria spp. and L. monocytogenes in a fish was significantly different among freshwater fish. A high incidence of these bacterial pathogens was found in the brown trout (Salmo trutta) and horse mackerel (Trachurus trachurus). Handling of contaminated fish, cross-contamination, or eating raw fish might pose a health hazard, especially in immunosuppressed individuals, elderly people, and children. This study highlights the importance of bacterial pathogens in fish intended for human consumption, but more study is needed.

  6. Spatiotemporal Dynamics of Total Viable Vibrio spp. in a NW Mediterranean Coastal Area.

    Science.gov (United States)

    Girard, Léa; Peuchet, Sébastien; Servais, Pierre; Henry, Annabelle; Charni-Ben-Tabassi, Nadine; Baudart, Julia

    2017-09-27

    A cellular approach combining Direct Viable Counting and Fluorescent In Situ Hybridization using a one-step multiple-probe technique and Solid Phase Cytometry (DVC-FISH-SPC) was developed to monitor total viable vibrios and cover the detection of a large diversity of vibrios. FISH combined three probes in the same assay and targeted sequences located at different positions on the 16S rRNA of Vibrio and Aliivibrio members. We performed a 10-month in situ study to investigate the weekly dynamics of viable vibrios relative to culturable counts at two northwestern Mediterranean coastal sites, and identified the key physicochemical factors for their occurrence in water using a multivariate analysis. Total viable and culturable cell counts showed the same temporal pattern during the warmer season, whereas the ratios between both methods were inverted during the colder seasons (<15°C), indicating that some of the vibrio community had entered into a viable but non-culturable (VBNC) state. We confirmed that Seawater Surface Temperature explained 51-62% of the total variance in culturable counts, and also showed that the occurrence of viable vibrios is controlled by two variables, pheopigment (15%) and phosphate (12%) concentrations, suggesting that other unidentified factors play a role in maintaining viability.

  7. Acute Otitis due to Vibrio fluvialis after Swimming

    Directory of Open Access Journals (Sweden)

    Ping-Jen Chen

    2012-01-01

    Full Text Available A 40-year-old female presented with purulent exudate through the left auditive duct and pain in the left ear region, which intensified during mastication. After collection of the pus from the left ear lesion, amoxicillin-clavulanic acid for seven days was prescribed for a presumed diagnosis of acute otitis. Four days later, the pus culture grew V. fluvialis which is further identified by API 20E identification system (bioMérieux. Following the successful completion of a course of antibiotics, the patient recovered completely and without complication. To the best of our knowledge, this is the first case of Vibrio fluvialis otitis after swimming in an immunocompetent patient.

  8. Aptamer-Based Paper Strip Sensor for Detecting Vibrio fischeri.

    Science.gov (United States)

    Shin, Woo-Ri; Sekhon, Simranjeet Singh; Rhee, Sung-Keun; Ko, Jung Ho; Ahn, Ji-Young; Min, Jiho; Kim, Yang-Hoon

    2018-05-14

    Aptamer-based paper strip sensor for detecting Vibrio fischeri was developed. Our method was based on the aptamer sandwich assay between whole live cells, V. fischeri and DNA aptamer probes. Following 9 rounds of Cell-SELEX and one of the negative-SELEX, V. fischeri Cell Aptamer (VFCA)-02 and -03 were isolated, with the former showing approximately 10-fold greater avidity (in the subnanomolar range) for the target cells when arrayed on a surface. The colorimetric response of a paper sensor based on VFCA-02 was linear in the range of 4 × 10 1 to 4 × 10 5 CFU/mL of target cell by using scanning reader. The linear regression correlation coefficient ( R 2 ) was 0.9809. This system shows promise for use in aptamer-conjugated gold nanoparticle probes in paper strip format for in-field detection of marine bioindicating bacteria.

  9. In situ measured elimination of Vibrio cholerae from brackish water.

    Science.gov (United States)

    Pérez, María Elena Martínez; Macek, Miroslav; Galván, María Teresa Castro

    2004-01-01

    In situ elimination of fluorescently labelled Vibrio cholerae (FLB) was measured in two saline water bodies in Mexico: in a brackish water lagoon, Mecoacán (Gulf of Mexico; State of Tabasco) and an athalassohaline lake, Alchichica (State of Puebla). Disappearance rates of fluorescently labelled V. cholera O1 showed that they were eliminated from the environment at an average rate of 32% and 63%/day, respectively (based on the bacterial standing stocks). The indirect immunofluorescence method confirmed the presence of V. cholerae O1 in the lagoon. However, the elimination of FLB was not directly related either to the presence or absence of the bacterium in the water body or to the phytoplankton concentration.

  10. Attenuation of Vibrio fischeri quorum sensing using rationally designed polymers.

    Science.gov (United States)

    Piletska, Elena V; Stavroulakis, Georgios; Karim, Kal; Whitcombe, Michael J; Chianella, Iva; Sharma, Anant; Eboigbodin, Kevin E; Robinson, Gary K; Piletsky, Sergey A

    2010-04-12

    A first attempt to attenuate the quorum sensing (QS) of a marine heterotroph microorganism, Vibrio fischeri , using signal molecule-sequestering polymers (SSPs) is presented. A set of rationally designed polymers with affinity toward a signal molecule of V. fischeri , N-(beta-ketocaproyl)-l-homoserine lactone (3-oxo-C6-AHL) was produced. It is reported that computationally designed polymers could sequester a signal molecule of V. fischeri and prevent QS-controlled phenotypes (in this case, bioluminescence) from being up-regulated. It was proven that the attenuation of bioluminescence of V. fischeri was due to sequestration of the signal molecule by specific polymers and not due to the toxicity of polymer or nonspecific depletion of nutrients. The ability to disrupt the bacterial communication using easy to synthesize and chemically inert polymers could provide a new concept for the development of pharmaceuticals and susceptible device coatings such as catheters.

  11. Vibrio cholerae as a predator: lessons from evolutionary principles

    Directory of Open Access Journals (Sweden)

    Stefan ePukatzki

    2013-12-01

    Full Text Available Diarrheal diseases are the second-most common cause of death among children under the age of five worldwide. Cholera alone, caused by the marine bacterium Vibrio cholerae, is responsible for several million cases and over 120,000 deaths annually. When contaminated water is ingested, V. cholerae passes through the gastric acid barrier, penetrates the mucin layer of the small intestine, and adheres to the underlying epithelial lining. V. cholerae multiplies rapidly, secretes cholera toxin, and exits the human host in vast numbers during diarrheal purges. How V. cholerae rapidly reaches such high numbers during each purge is not clearly understood. We propose that V. cholerae employs its bactericidal type VI secretion system to engage in intraspecies and intraguild predation for nutrient acquisition to support rapid growth and multiplication.

  12. Impacts of Climatic Variability on Vibrio parahaemolyticus Outbreaks in Taiwan

    Science.gov (United States)

    Hsiao, Hsin-I; Jan, Man-Ser; Chi, Hui-Ju

    2016-01-01

    This study aimed to investigate and quantify the relationship between climate variation and incidence of Vibrio parahaemolyticus in Taiwan. Specifically, seasonal autoregressive integrated moving average (ARIMA) models (including autoregression, seasonality, and a lag-time effect) were employed to predict the role of climatic factors (including temperature, rainfall, relative humidity, ocean temperature and ocean salinity) on the incidence of V. parahaemolyticus in Taiwan between 2000 and 2011. The results indicated that average temperature (+), ocean temperature (+), ocean salinity of 6 months ago (+), maximum daily rainfall (current (−) and one month ago (−)), and average relative humidity (current and 9 months ago (−)) had significant impacts on the incidence of V. parahaemolyticus. Our findings offer a novel view of the quantitative relationship between climate change and food poisoning by V. parahaemolyticus in Taiwan. An early warning system based on climate change information for the disease control management is required in future. PMID:26848675

  13. Bile Sensing: The Activation of Vibrio parahaemolyticus Virulence

    Directory of Open Access Journals (Sweden)

    Bey-Hing Goh

    2017-04-01

    Full Text Available Bacteria must develop resistance to various inhospitable conditions in order to survive in the human gastrointestinal tract. Bile, which is secreted by the liver, and plays an important role in food digestion also has antimicrobial properties and is able to disrupt cellular homeostasis. Paradoxically, although bile is one of the guts defenses, many studies have reported that bacteria such as Vibrio parahaemolyticus can sense bile and use its presence as an environmental cue to upregulate virulence genes during infection. This article aims to discuss how bile is detected by V. parahaemolyticus and its role in regulating type III secretion system 2 leading to human infection. This bile–bacteria interaction pathway gives us a clearer understanding of the biochemical and structural analysis of the bacterial receptors involved in mediating a response to bile salts which appear to be a significant environmental cue during initiation of an infection.

  14. Impacts of Climatic Variability on Vibrio parahaemolyticus Outbreaks in Taiwan

    Directory of Open Access Journals (Sweden)

    Hsin-I Hsiao

    2016-02-01

    Full Text Available This study aimed to investigate and quantify the relationship between climate variation and incidence of Vibrio parahaemolyticus in Taiwan. Specifically, seasonal autoregressive integrated moving average (ARIMA models (including autoregression, seasonality, and a lag-time effect were employed to predict the role of climatic factors (including temperature, rainfall, relative humidity, ocean temperature and ocean salinity on the incidence of V. parahaemolyticus in Taiwan between 2000 and 2011. The results indicated that average temperature (+, ocean temperature (+, ocean salinity of 6 months ago (+, maximum daily rainfall (current (− and one month ago (−, and average relative humidity (current and 9 months ago (− had significant impacts on the incidence of V. parahaemolyticus. Our findings offer a novel view of the quantitative relationship between climate change and food poisoning by V. parahaemolyticus in Taiwan. An early warning system based on climate change information for the disease control management is required in future.

  15. Impacts of Climatic Variability on Vibrio parahaemolyticus Outbreaks in Taiwan.

    Science.gov (United States)

    Hsiao, Hsin-I; Jan, Man-Ser; Chi, Hui-Ju

    2016-02-03

    This study aimed to investigate and quantify the relationship between climate variation and incidence of Vibrio parahaemolyticus in Taiwan. Specifically, seasonal autoregressive integrated moving average (ARIMA) models (including autoregression, seasonality, and a lag-time effect) were employed to predict the role of climatic factors (including temperature, rainfall, relative humidity, ocean temperature and ocean salinity) on the incidence of V. parahaemolyticus in Taiwan between 2000 and 2011. The results indicated that average temperature (+), ocean temperature (+), ocean salinity of 6 months ago (+), maximum daily rainfall (current (-) and one month ago (-)), and average relative humidity (current and 9 months ago (-)) had significant impacts on the incidence of V. parahaemolyticus. Our findings offer a novel view of the quantitative relationship between climate change and food poisoning by V. parahaemolyticus in Taiwan. An early warning system based on climate change information for the disease control management is required in future.

  16. Vibrio cholerae infection, novel drug targets and phage therapy.

    Science.gov (United States)

    Fazil, Mobashar Hussain Urf Turabe; Singh, Durg V

    2011-10-01

    Vibrio cholerae is the causative agent of the diarrheal disease cholera. Although antibiotic therapy shortens the duration of diarrhea, excessive use has contributed to the emergence of antibiotic resistance in V. cholerae. Mobile genetic elements have been shown to be largely responsible for the shift of drug resistance genes in bacteria, including some V. cholerae strains. Quorum sensing communication systems are used for interaction among bacteria and for sensing environmental signals. Sequence analysis of the ctxB gene of toxigenic V. cholerae strains demonstrated its presence in multiple cholera toxin genotypes. Moreover, bacteriophage that lyse the bacterium have been reported to modulate epidemics by decreasing the required infectious dose of the bacterium. In this article, we will briefly discuss the disease, its clinical manifestation, antimicrobial resistance and the novel approaches to locate drug targets to treat cholera.

  17. Competitive Dominance by a Bacteriocin-Producing Vibrio harveyi Strain.

    Science.gov (United States)

    Hoyt, P R; Sizemore, R K

    1982-09-01

    Vibrio (Beneckea) harveyi, a bioluminescent marine bacterium, has been shown to produce a bacteriocin-like substance the production of which is mediated by a plasmid. This substance is assumed to be proteinaceous because of its sensitivity to certain proteolytic enzymes. It is stable at low temperatures and can be concentrated by ammonium sulfate precipitation or negative-pressure dialysis. The molecular weight of the bacteriocin was determined to be 2.4 x 10 by molecular exclusion chromatography. Competition experiments indicated that bacteriocin-producing strains predominated over cured variants of the same strain in broth culture experiments. We studied several environmental parameters (pH, salinity, temperature, nutrient concentration) to determine their effects on the competitive advantage bestowed on a bacteriocin-producing strain. Under simulated free-living conditions, no competitive advantage attributable to bacteriocin production was observed. In a simulated enteric habitat, a bacteriocin-producing strain showed dramatic (>90%) inhibition of the sensitive strain within 24 h.

  18. Sequence and features of the tryptophan operon of Vibrio parahemolyticus.

    Science.gov (United States)

    Crawford, I P; Han, C Y; Silverman, M

    1991-01-01

    The nucleotide sequence of the trp operon of the marine enteric bacterium Vibrio parahemolyticus is presented. The gene order E, G, D, C(F), B, A is identical to that of other enterics. The structural genes of the operon are preceded by a long leader region encoding a 41-residue peptide containing five tryptophan residues. The organization of the leader region suggests that transcription of the operon is subject to attenuation control. The promoter-operator region of the V. parahemolyticus trp operon is almost identical to the corresponding promoter-operator of E. coli. The similarities suggest that promoter strength and operator function are identical in the two species, and that transcription initiation is regulated by repression. The operon appears to lack the internal promoter within trpD that is common in terrestrial enteric species.

  19. Virulence of luminous vibrios to Artemia franciscana nauplii.

    Science.gov (United States)

    Soto-Rodriguez, S A; Roque, A; Lizarraga-Partida, M L; Guerra-Flores, A L; Gomez-Gill, B

    2003-02-27

    From healthy and diseased penaeid shrimp from Asia and the Americas, 25 luminous and 2 non-luminous bacterial strains were isolated, and 14 were phenotypically identified as Vibrio harveyi; 9 isolates produced significant mortalities (45 to 80%) in Artemia franciscana nauplii at inoculation densities of 10(5) to 10(6) CFU ml(-1) compared to the controls (unchallenged nauplii). The maximum number of bacteria ingested (bioencapsulated) by the Artemia nauplii varied from less than 10 to 10(3) CFU nauplius(-1) and no significant relationship was observed between the density of bacteria inoculated, the amount of bacteria ingested, and naupliar mortality. Significant correlations were obtained between naupliar mortality and production of proteases, phospholipases or siderophores, but not between mortality and lipase production, gelatinase production, hydrophobicity or hemolytic activity. The results suggest that virulence of the strains tested was more related to the production of particular exoenzymes than to the measured colonization factors.

  20. Effects of Dry Storage and Resubmersion of Oysters on Total Vibrio vulnificus and Total and Pathogenic (tdh+/trh+) Vibrio parahaemolyticus Levels.

    Science.gov (United States)

    Kinsey, Thomas P; Lydon, Keri A; Bowers, John C; Jones, Jessica L

    2015-08-01

    Vibrio vulnificus (Vv) and Vibrio parahaemolyticus (Vp) are the two leading causes of bacterial illnesses associated with raw shellfish consumption. Levels of these pathogens in oysters can increase during routine antifouling aquaculture practices involving dry storage in ambient air conditions. After storage, common practice is to resubmerge these stored oysters to reduce elevated Vv and Vp levels, but evidence proving the effectiveness of this practice is lacking. This study examined the changes in Vv and in total and pathogenic (thermostable direct hemolysin gene and the tdh-related hemolysin gene, tdh+ and trh+) Vp levels in oysters after 5 or 24 h of dry storage (28 to 32°C), followed by resubmersion (27 to 32°C) for 14 days. For each trial, replicate oyster samples were collected at initial harvest, after dry storage, after 7 days, and after 14 days of resubmersion. Oysters not subjected to dry storage were collected and analyzed to determine natural undisturbed vibrio levels (background control). Vibrio levels were measured using a most-probable-number enrichment followed by real-time PCR. After storage, vibrio levels (excluding tdh+ and trh+ Vp during 5-h storage) increased significantly (P oysters stored for 5 h) were not significantly different (P oysters. Vv and total and pathogenic Vp levels were not significantly different (P > 0.1) from levels in background oysters after 14 days of resubmersion, regardless of dry storage time. These data demonstrate that oyster resubmersion after dry storage at elevated ambient temperatures allows vibrio levels to return to those of background control samples. These results can be used to help minimize the risk of Vv and Vp illnesses and to inform the oyster industry on the effectiveness of routine storing and resubmerging of aquaculture oysters.

  1. Ozone Disinfection of Vibrio vulnificus in Shrimp Pond Water

    Science.gov (United States)

    Dyah Pita Rengga, Wara; Cahya Julyta Putri, Echa; Wulansarie, Ria; Suryanto, Agus

    2018-03-01

    One variety of shrimp, L.Vanamei, often uses brackish water during the operation in the shrimp pond. Chlorination and ultraviolet are usually used for disinfection of brackish water. However, it is ineffective and forms sediment in the water distribution. It can be a negative impact on the water quality cause a contamination on the shrimp, so the farmers might have loss of profit because Vibrio vulnificus causes infection and dead on the shrimp. It affects the safety of consumers and should be minimized. The purpose of this study is to reduce the number of V. vulnificus bacteria in the pond water. The water was put in the storage tanks then pumped to filter out the impurities of the water. Furthermore, the water set the flow rate in 1 LPM, 2 LPM, and 3 LPM. After that, the ozone was injected to the water flow to sterilize the V. vulnificus bacteria. Finally, the water was returned to the original tank. The water from the tank was taken through a valve and analyzed in 0, 3, 7, 12, 18, 24, 30 minutes. The sample was analyzed immediately using a Total Plate Count method to determine the number of V. vulnificus bacteria in the shrimp pond water. The flow rate shows that the longer time of ozone made a lower amount of Vibrio v. bacteria. In 2 LPM water, it shows the optimum results of V. vulnificus. bacteria reduction for 88.1% compared to the flow rate of 1 LPM and 3 LPM with the bacteria reduction of 68,8% and 70.6%. This study shows that the ozone with a flow rate of 2 LPM circulation is the most effective method to help reducing the number of V. vulnificus in brackish water distribution system in the shrimp environment and potentially as a disinfectant.

  2. Autoinducers act as biological timers in Vibrio harveyi.

    Science.gov (United States)

    Anetzberger, Claudia; Reiger, Matthias; Fekete, Agnes; Schell, Ursula; Stambrau, Nina; Plener, Laure; Kopka, Joachim; Schmitt-Kopplin, Phillippe; Hilbi, Hubert; Jung, Kirsten

    2012-01-01

    Quorum sensing regulates cell density-dependent phenotypes and involves the synthesis, excretion and detection of so-called autoinducers. Vibrio harveyi strain ATCC BAA-1116 (recently reclassified as Vibrio campbellii), one of the best-characterized model organisms for the study of quorum sensing, produces and responds to three autoinducers. HAI-1, AI-2 and CAI-1 are recognized by different receptors, but all information is channeled into the same signaling cascade, which controls a specific set of genes. Here we examine temporal variations of availability and concentration of the three autoinducers in V. harveyi, and monitor the phenotypes they regulate, from the early exponential to the stationary growth phase in liquid culture. Specifically, the exponential growth phase is characterized by an increase in AI-2 and the induction of bioluminescence, while HAI-1 and CAI-1 are undetectable prior to the late exponential growth phase. CAI-1 activity reaches its maximum upon entry into stationary phase, while molar concentrations of AI-2 and HAI-1 become approximately equal. Similarly, autoinducer-dependent exoproteolytic activity increases at the transition into stationary phase. These findings are reflected in temporal alterations in expression of the luxR gene that encodes the master regulator LuxR, and of four autoinducer-regulated genes during growth. Moreover, in vitro phosphorylation assays reveal a tight correlation between the HAI-1/AI-2 ratio as input and levels of receptor-mediated phosphorylation of LuxU as output. Our study supports a model in which the combinations of autoinducers available, rather than cell density per se, determine the timing of various processes in V. harveyi populations.

  3. Autoinducers act as biological timers in Vibrio harveyi.

    Directory of Open Access Journals (Sweden)

    Claudia Anetzberger

    Full Text Available Quorum sensing regulates cell density-dependent phenotypes and involves the synthesis, excretion and detection of so-called autoinducers. Vibrio harveyi strain ATCC BAA-1116 (recently reclassified as Vibrio campbellii, one of the best-characterized model organisms for the study of quorum sensing, produces and responds to three autoinducers. HAI-1, AI-2 and CAI-1 are recognized by different receptors, but all information is channeled into the same signaling cascade, which controls a specific set of genes. Here we examine temporal variations of availability and concentration of the three autoinducers in V. harveyi, and monitor the phenotypes they regulate, from the early exponential to the stationary growth phase in liquid culture. Specifically, the exponential growth phase is characterized by an increase in AI-2 and the induction of bioluminescence, while HAI-1 and CAI-1 are undetectable prior to the late exponential growth phase. CAI-1 activity reaches its maximum upon entry into stationary phase, while molar concentrations of AI-2 and HAI-1 become approximately equal. Similarly, autoinducer-dependent exoproteolytic activity increases at the transition into stationary phase. These findings are reflected in temporal alterations in expression of the luxR gene that encodes the master regulator LuxR, and of four autoinducer-regulated genes during growth. Moreover, in vitro phosphorylation assays reveal a tight correlation between the HAI-1/AI-2 ratio as input and levels of receptor-mediated phosphorylation of LuxU as output. Our study supports a model in which the combinations of autoinducers available, rather than cell density per se, determine the timing of various processes in V. harveyi populations.

  4. Dynamics of Vibrio with virulence genes detected in Pacific harbor seals (Phoca vitulina richardii) off California: implications for marine mammal health.

    Science.gov (United States)

    Hughes, Stephanie N; Greig, Denise J; Miller, Woutrina A; Byrne, Barbara A; Gulland, Frances M D; Harvey, James T

    2013-05-01

    Given their coastal site fidelity and opportunistic foraging behavior, harbor seals (Phoca vitulina) may serve as sentinels for coastal ecosystem health. Seals using urbanized coastal habitat can acquire enteric bacteria, including Vibrio that may affect their health. To understand Vibrio dynamics in seals, demographic and environmental factors were tested for predicting potentially virulent Vibrio in free-ranging and stranded Pacific harbor seals (Phoca vitulina richardii) off California. Vibrio prevalence did not vary with season and was greater in free-ranging seals (29 %, n = 319) compared with stranded seals (17 %, n = 189). Of the factors tested, location, turbidity, and/or salinity best predicted Vibrio prevalence in free-ranging seals. The relationship of environmental factors with Vibrio prevalence differed by location and may be related to oceanographic or terrestrial contributions to water quality. Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio cholerae were observed in seals, with V. cholerae found almost exclusively in stranded pups and yearlings. Additionally, virulence genes (trh and tdh) were detected in V. parahaemolyticus isolates. Vibrio cholerae isolates lacked targeted virulence genes, but were hemolytic. Three out of four stranded pups with V. parahaemolyticus (trh+ and/or tdh+) died in rehabilitation, but the role of Vibrio in causing mortality is unclear, and Vibrio expression of virulence genes should be investigated. Considering that humans share the environment and food resources with seals, potentially virulent Vibrio observed in seals also may be of concern to human health.

  5. Investigating the decay rates of Escherichia coli relative to Vibrio parahemolyticus and Salmonella Typhi in tropical coastal waters.

    Science.gov (United States)

    Lee, Choon Weng; Ng, Angie Yee Fang; Bong, Chui Wei; Narayanan, Kumaran; Sim, Edmund Ui Hang; Ng, Ching Ching

    2011-02-01

    Using the size fractionation method, we measured the decay rates of Escherichia coli, Salmonella Typhi and Vibrio parahaemolyticus in the coastal waters of Peninsular Malaysia. The size fractions were total or unfiltered, 0.7 μm) than in the smaller fraction (Vibrio grew well in seawater. There was usually an increase in Vibrio after one day incubation. Our results confirmed that decay or loss rates of E. coli did not match that of Vibrio, and also did not correlate with Salmonella decay rates. However E. coli showed persistence where its decay rates were generally lower than Salmonella. © 2010 Elsevier Ltd. All rights reserved.

  6. Does gestrinone antagonize the effects of estrogen on endometrial implants upon the peritoneum of rats?

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Rodrigues Lobo

    2008-01-01

    Full Text Available OBJECTIVE: To evaluate the effects of estrogen treatment in combination with gestrinone on an experimental rat model of endometriosis. METHODS: Uterine transplants were attached to the peritoneum of female Wistar rats via a surgical autotransplantation technique. The implanted area was measured during the proestrus phase and after hormonal treatment. We performed morphometric analysis and examined the macroscopic and morphometric alterations of endometrial implants after hormonal treatment in ovariectomized rats. RESULTS: The high dose of estrogen caused macroscopic increases in the endometrial implant group compared with other groups, which were similar to increases in the proestrus phase. The low dose showed morphometric development of implants, such as an increase in number of endometrial glands, leukocyte infiltration and mitosis. Gestrinone antagonized both doses of estrogen. CONCLUSION: Our findings suggest that gestrinone antagonizes estrogen's effects on rat peritoneal endometrial implants.

  7. Complement C5a receptor antagonism by protamine and poly-L-Arg on human leukocytes.

    Science.gov (United States)

    Olsen, U B; Selmer, J; Kahl, J U

    1988-01-01

    It is shown that protamine selectively and dose-dependently inhibits complement C5a-induced leukocyte responses such as histamine release from basophils, chemiluminescence and beta-glucuronidase release from neutrophils. Protamine produces parallel rightward displacements of the C5a dose-response curves. The inhibitory capacity of the polypeptide is reversible and disappears following repeated washing of exposed cells. In neutrophils poly-L-Arg similarly and specifically antagonizes C5a-induced chemiluminescence and enzyme release. This polymer alone, however, degranulates basophils and neutrophils, leading to histamine and enzyme release, respectively. It is concluded that on human neutrophils the arginine-rich polycations protamine and poly-L-Arg exhibit a competitive C5a receptor antagonism. In addition, protamine inhibits the C5a receptors on basophils. It is hypothesized that molecular conformations of the arginine-rich polycations might bind reversibly to, and block negatively charged groups at the C5a-receptor sites.

  8. [Antagonism in vitro among phytopathogenic and saprobic fungi from horticultural soils].

    Science.gov (United States)

    Alippi, H E; Monaco, C

    1990-01-01

    Two methods were tested in order to determine the existence of in vitro antagonism among saprobic and pathogenic fungi. These microorganisms were the most common isolates from horticultural soils of La Plata (Buenos Aires). Trichoderma harzianum; T. koningii and Penicillium sp. were antagonistic to all the pathogenic fungi tested, Fusarium solani; F. oxysporum; Alternaria solani; Colletotrichum sp. and Sclerotium rolfsii Spicaria sp., Paecilomyces sp. and Chaetomiun sp. were antagonistic only to Colletotrichum sp. and Fusarium solani.

  9. Evaluation of the antagonism of nicotine by mecamylamine and pempidine in the brain

    International Nuclear Information System (INIS)

    Martin, T.J.

    1989-01-01

    Antagonists have been crucial in the characterization of nicotine's pharmacology. Initial evidence for the existence of central nicotinic receptors was based on the fact that nicotine produced a number of behavioral effects that were antagonized by ganglionic blockers that crossed the blood-brain barrier, such as mecamylamine and pempidine. These compounds are thought to be noncompetitive antagonists due to the fact that they do not compete for agonist binding to brain homogenate in vitro. However, pharmacological evidence in support of noncompetitive antagonism is lacking. Dose-response curves for nicotine were determined in the presence of various doses of pempidine for depression of spontaneous activity and antinociception in mice. Pempidine was found to shift the dose response curves for these effects of nicotine in a manner consistent with noncompetitive antagonism. A number of mecamylamine analogs were investigated for antagonism of these central effects of nicotine as well. These studies revealed that the N-, 2-, and 3-methyls were crucial for optimal efficacy and potency and suggests that these compounds possess a specific mechanism of action, possibly involving a receptor. Furthermore, the structure-activity relationships for the mecamylamine analogs were found to be different than that previously reported for the agonists, suggesting that they do not act at the same site. The binding of [ 3 H]-L-nicotine and [ 3 H]-pempidine was studied in vitro to mouse brain homogentate and in situ to rat brain slices. The in situ binding of [ 3 H]-L-nicotine to rat brain slices was quantitated autoradiographically to discrete brain areas in the presence and absence of 1, 10 and 100 μM nicotine and pempidine. Pempidine did not effectively displace [ 3 H]-L-nicotine binding

  10. Recovery and evolutionary analysis of complete integron gene cassette arrays from Vibrio

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    Gillings Michael R

    2006-01-01

    Full Text Available Abstract Background Integrons are genetic elements capable of the acquisition, rearrangement and expression of genes contained in gene cassettes. Gene cassettes generally consist of a promoterless gene associated with a recombination site known as a 59-base element (59-be. Multiple insertion events can lead to the assembly of large integron-associated cassette arrays. The most striking examples are found in Vibrio, where such cassette arrays are widespread and can range from 30 kb to 150 kb. Besides those found in completely sequenced genomes, no such array has yet been recovered in its entirety. We describe an approach to systematically isolate, sequence and annotate large integron gene cassette arrays from bacterial strains. Results The complete Vibrio sp. DAT722 integron cassette array was determined through the streamlined approach described here. To place it in an evolutionary context, we compare the DAT722 array to known vibrio arrays and performed phylogenetic analyses for all of its components (integrase, 59-be sites, gene cassette encoded genes. It differs extensively in terms of genomic context as well as gene cassette content and organization. The phylogenetic tree of the 59-be sites collectively found in the Vibrio gene cassette pool suggests frequent transfer of cassettes within and between Vibrio species, with slower transfer rates between more phylogenetically distant relatives. We also identify multiple cases where non-integron chromosomal genes seem to have been assembled into gene cassettes and others where cassettes have been inserted into chromosomal locations outside integrons. Conclusion Our systematic approach greatly facilitates the isolation and annotation of large integrons gene cassette arrays. Comparative analysis of the Vibrio sp. DAT722 integron obtained through this approach to those found in other vibrios confirms the role of this genetic element in promoting lateral gene transfer and suggests a high rate of gene

  11. In vitro antagonism of Trichoderma harzianum Rifai against Mycosphaerella fijiensis Morelet

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    Mayra Acosta-Suárez

    2013-10-01

    Full Text Available The in vitro antagonism of Trichoderma harzianum against Mycosphaerella fijiensis, foliar pathogen of banana and plantain, was evaluated. The assays were performed using the dual culture method. Competition for space and nutrients, the antagonistic capacity and forms and intensity of antagonism were determined considering the invasion of the surface of the colony, colonization and sporulation of T. harzianum on M. fijiensis after seven days of inoculation. Finally, the effect of volatile metabolites of T. harzianum was evaluated. The results showed in vitro antagonism of T. harzianum against M. fijiensis by competition for space and nutrients of the culture medium. Trichoderma grew over the pathogen colony with hyperparasitism and high intensity. Also, it completely covered the surface of the culture medium. T. harzianum not inhibited the growth of M. fijiensis by volatile metabolites. Damage was observed in the integrity of the cell wall of M. fijiensis hyphae and the cell content exit. The use of antagonistic fungi, could contribute to the design of strategies for integrated management of this disease. Key words: banana and plantain, biocontrol, mechanisms of action

  12. Arctigenin antagonizes mineralocorticoid receptor to inhibit the transcription of Na/K-ATPase.

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    Cheng, Ye; Zhou, Meili; Wang, Yan

    2016-01-01

    Hypertension is one of the most important risk factors in cardiovascular disease and is the most common chronic disease. Mineralocorticoid receptor (MR) antagonists have been successfully used in clinic for the treatment of hypertension. Our study aims to investigate whether Arctigenin can antagonize MR and inhibit the transcription of Na/K-ATPase. The yeast two-hybrid assay was used to screen natural products and Arctigenin was identified as an MR antagonist. The direct binding of Arctigenin to MR was determined using assays based on surface plasmon resonance, differential scanning calorimetry and fluorescence quenching. Furthermore, results from mammalian one-hybrid and transcriptional activation experiments also confirmed that Arctigenin can potently antagonize MR in cells. We demonstrated that Arctigenin can decrease the level of Na/K-ATPase mRNA by antagonizing MR in HK-2 cells. Our findings show that Arctigenin can effectively decrease Na/K-ATPase transcription; thus highlight its potential as an anti-hypertensive drug lead compound. Our current findings demonstrate that Arctigenin is an antagonist of MR and effectively decreases the Na/K-ATPase 1 gene expression. Our work provides a hint for the drug discovery against cardiovascular disease.

  13. Antagonism of Sorafenib and Regorafenib actions by platelet factors in hepatocellular carcinoma cell lines

    International Nuclear Information System (INIS)

    D’Alessandro, Rosalba; Refolo, Maria G; Lippolis, Catia; Giannuzzi, Grazia; Carella, Nicola; Messa, Caterina; Cavallini, Aldo; Carr, Brian I

    2014-01-01

    Platelets are frequently altered in hepatocellular carcinoma (HCC) patients. Platelet lysates (hPL) can enhance HCC cell growth and decrease apoptosis. The aims were to evaluate whether hPL can modulate the actions of Sorafenib or Regorafenib, two clinical HCC multikinase antagonists. Several human HCC cell lines were grown in the presence and absence of Sorafenib or Regorafenib, with or without hPL. Growth was measured by MTT assay, apoptosis was assessed by Annexin V and by western blot, and autophagy and MAPK growth signaling were also measured by western blot, and migration and invasion were measured by standard in vitro assays. Both Sorafenib and Regorafenib-mediated inhibition of cell growth, migration and invasion were all antagonized by hPL. Drug-mediated apoptosis and decrease in phospho-ERK levels were both blocked by hPL, which also increased anti-apoptotic phospho-STAT, Bax and Bcl-xL levels. Preliminary data, obtained with epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I), included in hPL, revealed that these factors were able to antagonized Sorafenib in a proliferation assay, in particular when used in combination. Platelet factors can antagonize Sorafenib or Regorafenib-mediated growth inhibition and apoptosis in HCC cells. The modulation of platelet activity or numbers has the potential to enhance multikinase drug actions

  14. [Antagonism against Beauveria bassiana by lipopeptide metabolites produced by entophyte Bacillus amyloliquefaciens strain SWB16].

    Science.gov (United States)

    Wang, Jingjie; Zhao, Dongyang; Liu, Yonggui; Ao, Xiang; Fan, Rui; Duan, Zhengqiao; Liu, Yanping; Chen, Qianqian; Jin, Zhixiong; Wan, Yongji

    2014-07-04

    We screened bacterial strains that have strong antagonism against Beauveria bassiana, an important pathogen of silkworm industry, and detected the antagonistic activity of lipopeptide metabolites. We identified bacterium SWB16 by morphological observation, physiological and biochemical experiments, 16SrRNA, and gyrA gene sequence analysis, tested antagonistic activity of strain SWB16 against Beauveria bassiana by measuring the inhibition zone diameter using filter paper diffusion method (Kirby-Bauer method), obtained lipopeptide metabolites of the strain using methanol extraction and observed the antagonism of strain SWB16 lipopeptide extracts against the conidia and hyphae of Beauveria bassiana, detected main ingredients and genes of lipopeptide metabolites by high-performance liquid chromatography-mass spectrometry and PCR amplification. SWB16 isolated from tissue of plant Dioscorea zingiberensis C. H. Wright belongs to Bacillus amyloliquefaciens and showed high antagonistic activity to Beauveria bassiana, and the lipopeptide extracts of isolate SWB16 exhibited significant inhibition to conidial germination and mycelial growth of Beauveria bassiana. The result of mass spectrometric detection indicated main component of the lipopeptide metabolites were fengcin and iturin, and genes fenB, ituA involved in the synthesis of them were amplified in the genome. Bacillus amyloliquefaciens strain SWB16 could produce lipopeptide antibiotics with strong antagonism to the entomopathogenic fungus Beauveria bassiana, and the results suggested that strain SWB16 has potential application value for controlling white muscardine of economic insects including silkworm.

  15. Relative contributions of Vibrio polysaccharide and quorum sensing to the resistance of Vibrio cholerae to predation by heterotrophic protists.

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    Shuyang Sun

    Full Text Available Protozoan grazing is a major mortality factor faced by bacteria in the environment. Vibrio cholerae, the causative agent of the disease cholera, is a natural inhabitant of aquatic ecosystems, and its survival depends on its ability to respond to stresses, such as predation by heterotrophic protists. Previous results show that grazing pressure induces biofilm formation and enhances a smooth to rugose morphotypic shift, due to increased expression of Vibrio polysaccharide (VPS. In addition to negatively controlling vps genes, the global quorum sensing (QS regulator, HapR, plays a role in grazing resistance as the ΔhapR strain is efficiently consumed while the wild type (WT is not. Here, the relative and combined contributions of VPS and QS to grazing resistance were investigated by exposing VPS and HapR mutants and double mutants in VPS and HapR encoding genes at different phases of biofilm development to amoeboid and flagellate grazers. Data show that the WT biofilms were grazing resistant, the VPS mutants were less resistant than the WT strain, but more resistant than the QS mutant strain, and that QS contributes to grazing resistance mainly in mature biofilms. In addition, grazing effects on biofilms of mixed WT and QS mutant strains were investigated. The competitive fitness of each strain in mixed biofilms was determined by CFU and microscopy. Data show that protozoa selectively grazed the QS mutant in mixed biofilms, resulting in changes in the composition of the mixed community. A small proportion of QS mutant cells which comprised 4% of the mixed biofilm biovolume were embedded in grazing resistant WT microcolonies and shielded from predation, indicating the existence of associational protection in mixed biofilms.

  16. Relationships between Environmental Factors and Pathogenic Vibrios in the Northern Gulf of Mexico ▿ †

    Science.gov (United States)

    Johnson, C. N.; Flowers, A. R.; Noriea, N. F.; Zimmerman, A. M.; Bowers, J. C.; DePaola, A.; Grimes, D. J.

    2010-01-01

    Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities. PMID:20817802

  17. Relationships between environmental factors and pathogenic Vibrios in the Northern Gulf of Mexico.

    Science.gov (United States)

    Johnson, C N; Flowers, A R; Noriea, N F; Zimmerman, A M; Bowers, J C; DePaola, A; Grimes, D J

    2010-11-01

    Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities.

  18. Ecology of Vibrio vulnificus in estuarine waters of eastern North Carolina.

    Science.gov (United States)

    Pfeffer, Courtney S; Hite, M Frances; Oliver, James D

    2003-06-01

    While several studies on the ecology of Vibrio vulnificus in Gulf Coast environments have been reported, there is little information on the distribution of this pathogen in East Coast waters. Thus, we conducted a multiyear study on the ecology of V. vulnificus in estuarine waters of the eastern United States, employing extensive multiple regression analyses to reveal the major environmental factors controlling the presence of this pathogen, and of Vibrio spp., in these environments. Monthly field samplings were conducted between July 2000 and April 2002 at six different estuarine sites along the eastern coast of North Carolina. At each site, water samples were taken and nine physicochemical parameters were measured. V. vulnificus isolates, along with estuarine bacteria, Vibrio spp., Escherichia coli organisms, and total coliforms, were enumerated in samples from each site by using selective media. During the last 6 months of the study, sediment samples were also analyzed for the presence of vibrios, including V. vulnificus. Isolates were confirmed as V. vulnificus by using hemolysin gene PCR or colony hybridization. V. vulnificus was isolated only when water temperatures were between 15 and 27 degrees C, and its presence correlated with water temperature and dissolved oxygen and vibrio levels. Levels of V. vulnificus in sediments were low, and no evidence for an overwintering in this environment was found. Multiple regression analysis indicated that vibrio levels were controlled primarily by temperature, turbidity, and levels of dissolved oxygen, estuarine bacteria, and coliforms. Water temperature accounted for most of the variability in the concentrations of both V. vulnificus (47%) and Vibrio spp. (48%).

  19. Vibrio sp. DSM 14379 pigment production--a competitive advantage in the environment?

    Science.gov (United States)

    Starič, Nejc; Danevčič, Tjaša; Stopar, David

    2010-10-01

    The ability to produce several antibacterial agents greatly increases the chance of producer's survival. In this study, red-pigmented Vibrio sp. DSM 14379 and Bacillus sp., both isolated from the same sampling volume from estuarine waters of the Northern Adriatic Sea, were grown in a co-culture. The antibacterial activity of the red pigment extract was tested on Bacillus sp. in microtiter plates. The MIC(50) for Bacillus sp. was estimated to be around 10⁻⁵ mg/L. The extract prepared form the nonpigmented mutant of Vibrio sp. had no antibacterial effect. The pigment production of Vibrio sp. was studied under different physicochemical conditions. There was no pigment production at high or low temperatures, high or low salt concentrations in peptone yeast extract (PYE) medium, low glucose concentration in mineral growth medium or high glucose concentration in PYE medium. This indicates that the red pigment production is a luxurious good that Vibrio sp. makes only under favorable conditions. The Malthusian fitness of Bacillus sp. in a co-culture with Vibrio sp. under optimal environmental conditions dropped from 4.0 to -7.6, which corresponds to three orders of magnitude decrease in the number of CFU relative to the monoculture. The nonpigmented mutant of Vibrio sp. in a co-culture with Bacillus sp. had a significant antibacterial activity. This result shows that studying antibacterial properties in isolation (i.e. pigment extract only) may not reveal full antibacterial potential of the bacterial strain. The red pigment is a redundant antibacterial agent of Vibrio sp.

  20. Investigation of Vibrio alginolyticus, V. harveyi, and V. parahaemolyticus in large yellow croaker, Pseudosciaena crocea (Richardson) reared in Xiangshan Bay, China

    OpenAIRE

    Lu Liu; Mingfeng Ge; Xiaoye Zheng; Zhen Tao; Suming Zhou; Guoliang Wang

    2016-01-01

    Large yellow croaker (LYC), Pseudosciaena crocea is an economically important fish species of mariculture in China. The variation of yearly production of LYC has been increasingly related to the outbreaks of fish diseases. Moreover, Vibrio infections have been identified in this fish frequently. To understand the pattern of Vibrio infections in LYC, we conducted a culture-independent survey of Vibrios in farmed LYC populations using a multiplex PCR method targeting Vibrio alginolyticus, Vibri...

  1. Impact of Hurricane Irene on Vibrio vulnificus and Vibrio parahaemolyticus concentrations in surface water, sediment and cultured oysters in the Chesapeake Bay, Maryland, USA

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    Kristi S Shaw

    2014-05-01

    Full Text Available To determine if a storm event (i.e., high winds, large volumes of precipitation could alter concentrations of Vibrio vulnificus and Vibrio parahaemolyticus in aquacultured oysters (Crassostrea virginica and associated surface water and sediment, this study followed a sampling timeline before and after Hurricane Irene impacted the Chesapeake Bay estuary in late August 2011. Aquacultured oysters were sampled from two levels in the water column: surface 0.3 m and near-bottom just above the sediment. Concentrations of each Vibrio spp. and associated virulence genes were measured in oysters with a combination of real-time PCR and most probable number enrichment methods, and in sediment and surface water with real-time PCR. While concentration shifts of each Vibrio species were apparent post-storm, statistical tests indicated no significant change in concentration change for either Vibrio species by location (surface or near bottom oysters or date sampled (oyster tissue, surface water and sediment concentrations. V. vulnificus in oyster tissue was correlated with total suspended solids (r=0.41, p=0.04, and V. vulnificus in sediment was correlated with secchi depth (r=-0.93, p< 0.01, salinity (r=-0.46, p=0.02, tidal height (r=-0.45, p=0.03, and surface water V. vulnificus (r=0.98, p< 0.01. V. parahaemolyticus in oyster tissue did not correlate with environmental measurements, but V. parahaemolyticus in sediment and surface water correlated with several measurements including secchi depth (r=-0.48, p=0.02[sediment]; r=-0.97 p< 0.01[surface water] and tidal height (r=-0.96. p< 0.01[sediment], r=-0.59,p< 0.01 [surface water]. The concentrations of Vibrio spp. were higher in oysters relative to other studies (average V. vulnificus 4x105 MPN g-1, V. parahaemolyticus 1x105 MPN g-1, and virulence-associated genes were detected in most oyster samples. This study provides a first estimate of storm-related Vibrio density changes in oyster tissues, sediment and

  2. An outbreak of Vibrio cholerae in Vikas Nagar, Chandigarh, India

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    Sonia Puri

    2014-01-01

    Full Text Available Background : On 1 July 2012, a large number of cases of acute diarrheal episodes were reported in Vikas Nagar, Chandigarh. A rapid response team was sent to investigate this outbreak on 3 July 2012. Aim : To determine the reasons for the outbreak and to focus on the identification of a gap in the management of the epidemic by applying remedial measures in the Vibrio cholera outbreak in the Vikas Nagar area of Chandigarh district. Materials and Methods : A house-to-house survey of 2765 houses was performed with 20 teams of Auxillary Nurse Midwife ANM/Anganwadi workers. Information regarding age, sex, place of residence, occupation, date of onset and treatment history and laboratory finding were collected. Environmental investigation and laboratory investigation of the stool samples were also performed. As the study was conducted during an emergency response to the outbreak, and was designed to provide information to orient the public health response, ethical approval was not required. Remedial measures were implemented. Results : A total of 1875 patients reported to the various health facilities of the Vikas Nagar area with complaints of increased frequency of loose watery diarrhea and a few had vomiting episodes during the time period of 1 - 14 July 2012. Four deaths were reported. Three hundred eighteen (318 cases were found in the house-to-house survey of 2765 houses of the area. Twenty-six percent of the cases were in the age group of 1800 MPN/100 mL was reported from 10 water samples. Investigations revealed that the epidemic was waterborne. Leakages in the pipes were found at many places leading to mixing of water with drainage, and water samples collected from the houses of the cases were found to be positive for Vibrio cholerae. Conclusion : Among the identified gaps, delays in the initiation of the investigation of the epidemic and pipe leakages were the most important. In India, waterborne epidemics are usual occurrences during the year

  3. Vibrio cholerae Colonization of Soft-Shelled Turtles.

    Science.gov (United States)

    Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin; Kan, Biao

    2017-07-15

    Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae -contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N -acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological

  4. Vibrio Phage KVP40 Encodes a Functional NAD+ Salvage Pathway.

    Science.gov (United States)

    Lee, Jae Yun; Li, Zhiqun; Miller, Eric S

    2017-05-01

    The genome of T4-type Vibrio bacteriophage KVP40 has five genes predicted to encode proteins of pyridine nucleotide metabolism, of which two, nadV and natV , would suffice for an NAD + salvage pathway. NadV is an apparent nicotinamide phosphoribosyltransferase (NAmPRTase), and NatV is an apparent bifunctional nicotinamide mononucleotide adenylyltransferase (NMNATase) and nicotinamide-adenine dinucleotide pyrophosphatase (Nudix hydrolase). Genes encoding the predicted salvage pathway were cloned and expressed in Escherichia coli , the proteins were purified, and their enzymatic properties were examined. KVP40 NadV NAmPRTase is active in vitro , and a clone complements a Salmonella mutant defective in both the bacterial de novo and salvage pathways. Similar to other NAmPRTases, the KVP40 enzyme displayed ATPase activity indicative of energy coupling in the reaction mechanism. The NatV NMNATase activity was measured in a coupled reaction system demonstrating NAD + biosynthesis from nicotinamide, phosphoribosyl pyrophosphate, and ATP. The NatV Nudix hydrolase domain was also shown to be active, with preferred substrates of ADP-ribose, NAD + , and NADH. Expression analysis using reverse transcription-quantitative PCR (qRT-PCR) and enzyme assays of infected Vibrio parahaemolyticus cells demonstrated nadV and natV transcription during the early and delayed-early periods of infection when other KVP40 genes of nucleotide precursor metabolism are expressed. The distribution and phylogeny of NadV and NatV proteins among several large double-stranded DNA (dsDNA) myophages, and also those from some very large siphophages, suggest broad relevance of pyridine nucleotide scavenging in virus-infected cells. NAD + biosynthesis presents another important metabolic resource control point by large, rapidly replicating dsDNA bacteriophages. IMPORTANCE T4-type bacteriophages enhance DNA precursor synthesis through reductive reactions that use NADH/NADPH as the electron donor and NAD

  5. Comparative genomic analysis of Vibrio parahaemolyticus: serotype conversion and virulence

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    Gil Ana I

    2011-06-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is a common cause of foodborne disease. Beginning in 1996, a more virulent strain having serotype O3:K6 caused major outbreaks in India and other parts of the world, resulting in the emergence of a pandemic. Other serovariants of this strain emerged during its dissemination and together with the original O3:K6 were termed strains of the pandemic clone. Two genomes, one of this virulent strain and one pre-pandemic strain have been sequenced. We sequenced four additional genomes of V. parahaemolyticus in this study that were isolated from different geographical regions and time points. Comparative genomic analyses of six strains of V. parahaemolyticus isolated from Asia and Peru were performed in order to advance knowledge concerning the evolution of V. parahaemolyticus; specifically, the genetic changes contributing to serotype conversion and virulence. Two pre-pandemic strains and three pandemic strains, isolated from different geographical regions, were serotype O3:K6 and either toxin profiles (tdh+, trh- or (tdh-, trh+. The sixth pandemic strain sequenced in this study was serotype O4:K68. Results Genomic analyses revealed that the trh+ and tdh+ strains had different types of pathogenicity islands and mobile elements as well as major structural differences between the tdh pathogenicity islands of the pre-pandemic and pandemic strains. In addition, the results of single nucleotide polymorphism (SNP analysis showed that 94% of the SNPs between O3:K6 and O4:K68 pandemic isolates were within a 141 kb region surrounding the O- and K-antigen-encoding gene clusters. The "core" genes of V. parahaemolyticus were also compared to those of V. cholerae and V. vulnificus, in order to delineate differences between these three pathogenic species. Approximately one-half (49-59% of each species' core genes were conserved in all three species, and 14-24% of the core genes were species-specific and in different

  6. Infection Vibrio sp. Bacteria on Kappaphycus Seaweed Varieties Brown and Green

    Science.gov (United States)

    Irmawati, Yuni; Sudirjo, Fien

    2017-10-01

    Disease in seaweed or ice-ice, until today is still a major problem in the cultivation of seaweed. Changes in extreme environmental conditions is a trigger factor of ice-ice, which can result in seaweed susceptible to infection with pathogenic microorganisms, such as bacteria Vibrio sp. This research aims to determine the bacteria Vibrio sp. infection in seaweed Kappaphycus varieties of brown and green. Vibrio sp. bacteria isolated in the infected seaweed thallus ice-ice, grown on TCBS media, purification, gram staining and biochemical tests. Vibrio sp. infected to seaweed Kappaphycus brown and green varieties in containers controlled by different density, 105 CFU/ml, 106 CFU/ml and 107CFU/ml. Observations were made to change clinical effect in thallus seaweed for 14 days of observation. The results obtained show that the levels of infection bacteria Vibrio sp. higher in seaweed Kappaphycus green varieties both in density 105 CFU/ml, 106 CFU/ml and 107CFU/ml, when compared with varieties brown.

  7. Increases in the amounts of Vibrio spp. in oysters upon addition of exogenous bacteria.

    Science.gov (United States)

    Froelich, Brett; Oliver, James

    2013-09-01

    The bacterial pathogen Vibrio vulnificus is found naturally in brackish coastal waters but can be greatly concentrated by filter-feeding organisms such as shellfish. Numerous experiments in which exogenous V. vulnificus cells are added to oysters in an attempt to measure uptake and depuration have been performed. In nearly all cases, results have shown that laboratory-grown bacteria are rapidly taken up by the oysters but ultimately eliminated, while naturally present Vibrio populations in oysters are resistant to depuration. In this study, oysters harvested during winter months, with low culturable Vibrio concentrations, were incubated in aquaria supplemented with strains of V. vulnificus that were either genotypically or phenotypically distinct from the background bacteria. These exogenous cells were eliminated from the oysters, as previously seen, but other vibrios already inhabiting the oysters responded to the V. vulnificus inoculum by rapidly increasing in number and maintaining a large stable population. The presence of such an oyster-adapted Vibrio population would be expected to prevent colonization by exogenous V. vulnificus cells, thus explaining the rapid depuration of these added bacteria.

  8. POTENCY OF VIBRIO ISOLATES FOR BIOCONTROL OF VIBRIOSIS IN TIGER SHRIMP (PENAEUS MONODON LARVAE

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    B. W. LAY

    2003-01-01

    Full Text Available This study was carried out to obtain Vibrio isolates able to function as biocontr ol of vibriosis in shrimp hatchery. Thirty one Vibrio isolates were isolated from tiger shrimp larvae and hatchery environments, i.e. Labuan, Pangandaran, and Lampung, Indonesia. Pathogenic V. harveyi MR5339 was obtained from Maros, South-Sulawesi and was made as a rifampicin resistant mutant (RFR to screen for those 31 Vibrio isolates in in vitro assays and to allow us to monitor their presence in shrimp larvae and larval rearing water. Almost all Vibrio isolates could inhibit the growth of pathogenic V. harveyi MR5339 RFR. SKT-b isolate from Skeletonema was the most effective to inhibit the growth of V. harveyi MR5339 Rf* and significantly reduced larval mortality in pathogen challenge assays. These prospective biocontrol bacteria, at concentration of 10" CFU/ml, did not show pathogenicity to shrimp larvae. SKT-b was Gram negative, short rod-shape, exhibited yellow colonies on TCBS and swarming on SWC-agar media, motile, u tilized glucose and sucrose but not lactose: produced extra-cellular protease and amylase, but did not produce chitmase. Partial sequencing of 16S-rRNA gene SKT-b showed SKT-b similarity to Vibrio alginofyticus.

  9. Identification of capsule, biofilm, lateral flagellum, and type IV pili in Vibrio mimicus strains.

    Science.gov (United States)

    Tercero-Alburo, J J; González-Márquez, H; Bonilla-González, E; Quiñones-Ramírez, E I; Vázquez-Salinas, C

    2014-11-01

    Vibrio mimicus is a bacterium that causes gastroenteritis; it is closely related to Vibrio cholerae, and can cause acute diarrhea like cholera- or dysentery-type diarrhea. It is distributed worldwide. Factors associated with virulence (such as hemolysins, enterotoxins, proteases, phospholipases, aerobactin, and hemagglutinin) have been identified; however, its pathogenicity mechanism is still unknown. In pathogenic Vibrio species such as V. cholerae, Vibrio. parahaemolyticus and Vibrio vulnificus, capsule, biofilms, lateral flagellum, and type IV pili are structures described as essential for pathogenicity. These structures had not been described in V. mimicus until this work. We used 20 V. mimicus strains isolated from water (6), oyster (9), and fish (5) samples and we were able to identify the capsule, biofilm, lateral flagellum, and type IV pili through phenotypic tests, electron microscopy, PCR, and sequencing. In all tested strains, we observed and identified the presence of capsular exopolysaccharide, biofilm formation in an in vitro model, as well as swarming, multiple flagellation, and pili. In addition, we identified homologous genes to those described in other bacteria of the genus in which these structures have been found. Identification of these structures in V. mimicus is a contribution to the biology of this organism and can help to reveal its pathogenic behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Inhibitory effects of Bacillus probionts on growth and toxin production of Vibrio harveyi pathogens of shrimp.

    Science.gov (United States)

    Nakayama, T; Lu, H; Nomura, N

    2009-12-01

    To investigate the effects of Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium in terms of toxin and growth of pathogenic Vibrio harveyi. Three Bacillus probionts were isolated from probiotic BZT aquaculture and identified using a 16S rDNA sequence. Growth inhibition assay showed that supernatants from the 24-h culture of three Bacillus species were able to inhibit the growth of V. harveyi (LMG 4044); B. subtilis was the most effective based on the well diffusion method. Results of a liquid culture model showed that B. subtilis was also widely effective in inhibiting three strains of V. harveyi (isolated from Thailand, the Philippines and LMG 4044), and that both B. licheniformis and B. megaterium inhibit the growth of V. harveyi isolated from the Philippines. Moreover, a haemolytic activity assay demonstrated that V. harveyi (IFO 15634) was significantly decreased by the addition of B. licheniformis or B. megaterium supernatant. Bacillus subtilis inhibited Vibrio growth, and both B. licheniformis and B. megaterium suppressed haemolytic activity in Vibrio. The cell-free supernatants produced by Bacillus probionts inhibit Vibrio disease, and Bacillus probionts might have an influence on Vibrio cell-to-cell communications.

  11. Potensi Ekstrak Daun Binahong (Anredera cordifolia Sebagai Penghambat Bakteri Vibrio harveyi

    Directory of Open Access Journals (Sweden)

    Gde Raka Angga Kartika

    2016-07-01

    Full Text Available Binahong (Anredera cordifolia is a plant that can treat various kinds of diseases, because this plant has a high antioxidant content and as an antibacterial and antiviral. Vibriosis disease caused by the bacterium Vibrio harveyi is a serious problem in marine and brackish culture, this disease can cause death for shrimp and fish that farmed in marine or brackish. This study aims to determine the potential of using leaf extract Binahong with different concentrations as Vibrio harveyi inhibiting bacterial growth in vitro. The method used is to test the Minimum inhibitory concentration (MIC to determine minimum levels inhibit the growth of Vibrio harveyi and Minimum Bactericidal Concentration (MBC using paper disc. The results showed the use of leaf extract Binahong (Anredera cordifolia with different concentrations significant effect on the growth of Vibrio harveyi in vitro. Binahong leaf extract (Anredera cordifolia with a concentration of 3%, 5%, 7%, 9%, 11% and 13% is only bacteriostatic which inhibits the growth of bacteria Vibrio harveyi with the best concentration obtained is equal to 13%.

  12. A novel bacteriocin-like substance (BLIS) from a pathogenic strain of Vibrio harveyi.

    Science.gov (United States)

    Prasad, Sathish; Morris, Peter C; Hansen, Rasmus; Meaden, Philip G; Austin, Brian

    2005-09-01

    Inter-strain and inter-species inhibition mediated by a bacteriocin-like inhibitory substance (BLIS) from a pathogenic Vibrio harveyi strain VIB 571 was demonstrated against four isolates of the same species, and one culture each of a Vibrio sp., Vibrio fischeri, Vibrio gazogenes and Vibrio parahaemolyticus. The crude BLIS, which was obtained by ammonium-sulphate precipitation of the cell-free supernatant of a 72 h broth culture of strain VIB 571, was inactivated by lipase, proteinase K, pepsin, trypsin, pronase E, SDS and incubation at > or =60 degrees C for 10 min. The activity was stable between pH 2-11 for at least 5 h. Anion-exchange chromatography, gel filtration, SDS-PAGE and two-dimensional gel electrophoresis revealed the presence of a single major peak, comprising a protein with a pI of approximately 5.4 and a molecular mass of approximately 32 kDa. The N-terminal amino acid sequence of the protein comprised Asp-Glu-Tyr-Ile-Ser-X-Asn-Lys-X-Ser-Ser-Ala-Asp-Ile (with X representing cysteine or modified amino acid residues). A similarity search based on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) generated peptide masses and the N-terminal sequence did not yield any significant matches.

  13. Phytoplankton production systems in a shellfish hatchery: variations of the bacterial load and diversity of vibrios.

    Science.gov (United States)

    Dubert, J; Fernández-Pardo, A; Nóvoa, S; Barja, J L; Prado, S

    2015-06-01

    Outbreaks of disease caused by some Vibrio species represent the main production bottleneck in shellfish hatcheries. Although the phytoplankton used as food is one of the main sources of bacteria, studies of the associated bacterial populations, specifically vibrios, are scarce. The aim of the study was the microbiological monitoring of the microalgae as the first step in assessing the risk disease for bivalve cultures. Two phytoplankton production systems were sampled weekly throughout 1-year period in a bivalve hatchery. Quantitative analysis revealed high levels of marine heterotrophic bacteria in both systems throughout the study. Presumptive vibrios were detected occasionally and at low concentrations. In most of the cases, they belonged to the Splendidus and Harveyi clades. The early detection of vibrios in the microalgae may be the key for a successful bivalve culture. Their abundance and diversity were affected by factors related to the hatchery environment. This work represents the first long study where the presence of vibrios was evaluated rigorously in phytoplankton production systems and provides a suitable microbiological protocol to control and guarantee the quality of the algal cultures to avoid the risk of transferring potential pathogens to shellfish larvae and/or broodstock. © 2015 The Society for Applied Microbiology.

  14. Occurrence of Vibrio and Salmonella species in mussels (Mytilus galloprovincialis) collected along the Moroccan Atlantic coast.

    Science.gov (United States)

    Mannas, Hasna; Mimouni, Rachida; Chaouqy, Noureddine; Hamadi, Fatima; Martinez-Urtaza, Jaime

    2014-01-01

    This study reports the occurrence of different Vibrio and Salmonella species in 52 samples of Mytilus galloprovincialis collected from four sites along the Atlantic coast between Agadir and Essaouira (Anza, Cap Ghir, Imssouane and Essaouira). The level of Escherichia coli (E. coli) was also determined to evaluate the degree of microbial pollution in the investigated areas. In this study three methods were used : AFNOR NF EN ISO 6579 V08-013 for Salmonella spp., the provisional method routinely used by several laboratories (Institut Pasteur, Paris,…) for Vibrio cholerae and Vibrio parahaemolyticus in the seafood, and the most probable number method (MPN) using Norm ISO/TS 16649-3 (2005) for E. coli. The most frequently isolated Vibrios were Vibrio alginolyticus (90.4% of samples), followed by V. cholerae non O1 non O139 (15.4%) and V. parahaemolyticus (7.7%). Salmonella spp. was found in 15% of the samples. The number of E. coli ranged between 0.2/100 g and 1.8 10(3) /100 g of mussel soft tissues. This study indicates the potential sanitary risk associated with the presence of pathogenic bacteria in cultivated mussels in the two populous regions of southern Morocco, where shellfish production and maritime tourism are important to the local economy.

  15. Screening of probiotic bacteria and its role on artificial infection of Vibrio harvey in white shrimp (Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    . Sukenda

    2007-07-01

    Full Text Available Probiotic was screened from 28 strains of normal bacterial flora isolated from rearing water in a Litopenaeus vannamei farm based on its inhibitory activity against the growth of Vibrio harveyi.  Antibacterial activity was also tested in vivo to V. harveyi in L. vannamei.  The result showed that  the probiotic has a antibacterial effect on V. harveyi.  The in vivo test showed that shrimps injected with probiotic previously before challenged with V. harveyi has survival higher than control.  Probiotic isolate was suspected as Vibrio furnissi. Keywords:  biocontrol, inhibitory activity, Vibrio furnissi, Vibrio harveyi, Litopenaeus vannamei   AbstraK Bakteri probiotik ditapis dari 28 strain bacteria flora yang diisolasi dari air pemeliharaan udang vaname Litopenaeus vannamei berdasarkan aktivitas penghambatannya terhadap pertumbuhan Vibrio harveyi.  Aktivitas bakteri probiotik juga diuji secara in vivo terhadap V. harveyi pada udang putih.  Hasil penelitian menunjukkan bahwa bakteri probiotik isolat memiliki kemampuan antibakteria terhadap V. harveyi.  Uji in vivo menunjukkan bahwa udang yang diinjeksi probiotik sebelum diuji tantang dengan V. harveyi memiliki kelangsungan hidup lebih tinggi daripada kontrol.  Isolat probiotik tersebut diduga adalah Vibrio furnissi. Kata kunci:  biokontrol, aktivitas penghambatan, Vibrio furnissi, Vibrio harveyi, Litopenaeus vannamei

  16. Sensitivity of Vibrio cholerae cells to lethal and mutagenic effect of UV-irradiation mediated by plasmids

    International Nuclear Information System (INIS)

    Tiganova, I.G.; Evdokimova, N.M.; Aleshkin, G.I.

    1988-01-01

    The effect of UV-irradiation on Vibrio cholerae cells and its changes mediated by the plasmid R245 have been studied. Vibrio cholerae strains 569B and RV31 have been shown to be considerably more sensitive to lethal effect of UV-irradiation as compared with Escherichia coli and Salmonella typhimurium cells. Highly toxigenic strain 569B and practically atoxigenic strain RV31 have the same UV-sensitivity. Lethla effect of UV-irradiation on Vibrio cholerae cells is incresed when the irradiated cells are plated on enriched media. UV-induction of mutations was not registered in plasmidless strains of Vibrio cholerae. Plasmid R245 increase UV-resistance of vibrio cells and makes them UV-mutable

  17. α-Hydroxyketone Synthesis and Sensing by Legionella and Vibrio

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    Hubert Hilbi

    2012-03-01

    Full Text Available Bacteria synthesize and sense low molecular weight signaling molecules, termed autoinducers, to measure their population density and community complexity. One class of autoinducers, the α-hydroxyketones (AHKs, is produced and detected by the water-borne opportunistic pathogens Legionella pneumophila and Vibrio cholerae, which cause Legionnaires’ disease and cholera, respectively. The “Legionella quorum sensing” (lqs or “cholera quorum sensing” (cqs genes encode enzymes that produce and sense the AHK molecules “Legionella autoinducer-1” (LAI-1; 3-hydroxypentadecane-4-one or cholera autoinducer-1 (CAI-1; 3-hydroxytridecane-4-one. AHK signaling regulates the virulence of L. pneumophila and V. cholerae, pathogen-host cell interactions, formation of biofilms or extracellular filaments, expression of a genomic “fitness island” and competence. Here, we outline the processes, wherein AHK signaling plays a role, and review recent insights into the function of proteins encoded by the lqs and cqs gene clusters. To this end, we will focus on the autoinducer synthases catalysing the biosynthesis of AHKs, on the cognate trans-membrane sensor kinases detecting the signals, and on components of the down-stream phosphorelay cascade that promote the transmission and integration of signaling events regulating gene expression.

  18. The repertoire of glycosphingolipids recognized by Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    John Benktander

    Full Text Available The binding of cholera toxin to the ganglioside GM1 as the initial step in the process leading to diarrhea is nowadays textbook knowledge. In contrast, the knowledge about the mechanisms for attachment of Vibrio cholerae bacterial cells to the intestinal epithelium is limited. In order to clarify this issue, a large number of glycosphingolipid mixtures were screened for binding of El Tor V. cholerae. Several specific interactions with minor complex non-acid glycosphingolipids were thereby detected. After isolation of binding-active glycosphingolipids, characterization by mass spectrometry and proton NMR, and comparative binding studies, three distinct glycosphingolipid binding patterns were defined. Firstly, V. cholerae bound to complex lacto/neolacto glycosphingolipids with the GlcNAcβ3Galβ4GlcNAc sequence as the minimal binding epitope. Secondly, glycosphingolipids with a terminal Galα3Galα3Gal moiety were recognized, and the third specificity was the binding to lactosylceramide and related compounds. V. cholerae binding to lacto/neolacto glycosphingolipids, and to the other classes of binding-active compounds, remained after deletion of the chitin binding protein GbpA. Thus, the binding of V. cholerae to chitin and to lacto/neolacto containing glycosphingolipids represents two separate binding specificities.

  19. Structure of Vibrio cholerae ribosome hibernation promoting factor

    International Nuclear Information System (INIS)

    De Bari, Heather; Berry, Edward A.

    2013-01-01

    The X-ray crystal structure of ribosome hibernation promoting factor from V. cholerae has been determined at 2.0 Å resolution. The crystal was phased by two-wavelength MAD using cocrystallized cobalt. The X-ray crystal structure of ribosome hibernation promoting factor (HPF) from Vibrio cholerae is presented at 2.0 Å resolution. The crystal was phased by two-wavelength MAD using cocrystallized cobalt. The asymmetric unit contained two molecules of HPF linked by four Co atoms. The metal-binding sites observed in the crystal are probably not related to biological function. The structure of HPF has a typical β–α–β–β–β–α fold consistent with previous structures of YfiA and HPF from Escherichia coli. Comparison of the new structure with that of HPF from E. coli bound to the Thermus thermophilus ribosome [Polikanov et al. (2012 ▶), Science, 336, 915–918] shows that no significant structural changes are induced in HPF by binding

  20. The pathogenesis, detection and prevention of Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Rongzhi eWang

    2015-03-01

    Full Text Available Vibrio parahaemolyticus, a Gram-negative motile bacterium that inhabits marine and estuarine environments throughout the world, is a major food-borne pathogen that causes life-threatening diseases in humans after the consumption of raw or undercooked seafood. The global occurrence of V. parahaemaolyticus accentuates the importance of investigating its virulence factors and their effects on the human host. This review describes the virulence factors of V. parahaemolyticus reported to date, including hemolysin, urease, two type III secretion systems (T3SS and two type VI secretion systems (T6SS, which both cause both cytotoxicity in cultured cells and enterotoxicity in animal models. We describe various types of detection methods, based on virulence factors, that are used for quantitative detection of V. parahaemolyticus in seafood. We also discuss some useful preventive measures and therapeutic strategies for the diseases mediated by V. parahaemolyticus, which can reduce, to some extent, the damage to humans and aquatic animals attributable to V. parahaemolyticus. This review extends our understanding of the pathogenic mechanisms of V. parahaemolyticus mediated by virulence factors and the diseases it causes in its human host. It should provide new insights for the diagnosis, treatment, and prevention of V. parahaemolyticus infection.

  1. Genetic characterization of trh positive Vibrio spp. isolated from Norway

    Directory of Open Access Journals (Sweden)

    Anette eBauer Ellingsen

    2013-12-01

    Full Text Available The thermostable direct hemolysin (TDH and/or TDH-related hemolysin (TRH genes are carried by most virulent Vibrio parahaemolyticus serovars. In Norway, trh+ V. parahaemolyticus constitute 4.4% and 4.5 % of the total number of V. parahaemolyticus isolated from blue mussel (Mytilus edulis and water, respectively. The trh gene is located in a region close to the gene cluster for urease production (ure. This region was characterized in V. parahaemolyticus strain TH3996 and it was found that a nickel transport operon (nik was located between the first gene (ureR and the rest of the ure cluster genes. The organization of the trh-ureR-nik-ure gene cluster in the Norwegian trh+ isolates was unknown. In this study, we explore the gene organization within the trh-ureR-nik-ure cluster for these isolates. PCR analyses revealed that the genes within the trh-ureR-nik-ure gene cluster of Norwegian trh+ isolates were organized in a similar fashion as reported previously for TH33996. Additionally, the phylogenetic relationship among these trh+ isolates was investigated using Multilocus Sequence Typing (MLST. Analysis by MLST or ureR-trh sequences generated two different phylogenetic trees for the same strains analyzed, suggesting that ureR-trh genes have been acquired at different times in Norwegian V. parahaemolyticus isolates. MLST results revealed that some pathogenic and non-pathogenic V. parahaemolyticus isolates in Norway appear to be highly genetically related.

  2. Genetic diversity and population structure of Vibrio cholerae.

    Science.gov (United States)

    Beltrán, P; Delgado, G; Navarro, A; Trujillo, F; Selander, R K; Cravioto, A

    1999-03-01

    Multilocus enzyme electrophoresis (MLEE) of 397 Vibrio cholerae isolates, including 143 serogroup reference strains and 244 strains from Mexico and Guatemala, identified 279 electrophoretic types (ETs) distributed in two major divisions (I and II). Linkage disequilibrium was demonstrated in both divisions and in subdivision Ic of division I but not in subdivision Ia, which includes 76% of the ETs. Despite this evidence of relatively frequent recombination, clonal lineages may persist for periods of time measured in at least decades. In addition to the pandemic clones of serogroups O1 and O139, which form a tight cluster of four ETs in subdivision Ia, MLEE analysis identified numerous apparent clonal lineages of non-O1 strains with intercontinental distributions. A clone of serogroup O37 that demonstrated epidemic potential in the 1960s is closely related to the pandemic O1/O139 clones, but the nontoxigenic O1 Inaba El Tor reference strain is not. A strain of serogroup O22, which has been identified as the most likely donor of exogenous rfb region DNA to the O1 progenitor of the O139 clone, is distantly related to the O1/O139 clones. The close evolutionary relationships of the O1, O139, and O37 epidemic clones indicates that new cholera clones are likely to arise by the modification of a lineage that is already epidemic or is closely related to such a clone.

  3. Non-01 Vibrio cholerae infections in Cancun, Mexico.

    Science.gov (United States)

    Finch, M J; Valdespino, J L; Wells, J G; Perez-Perez, G; Arjona, F; Sepulveda, A; Bessudo, D; Blake, P A

    1987-03-01

    To determine the role of Vibrio cholerae as a cause of diarrheal illness in Cancun, Mexico, an investigation was conducted in July and August 1983. Although toxigenic V. cholerae 01 were not found, non-01 V. cholerae were isolated from 22 (16%) of 134 stools from persons with diarrheal illness and none of 22 stools from well persons; 58 (92%) of 63 sewage samples; 12 (86%) of 14 untreated well water samples; a home storage tank for treated water; and 5 (21%) of 24 samples of raw seafood. None of the V. cholerae isolates from patients were toxigenic. The illness occurred mainly in small children, and were characterized principally by diarrhea and abdominal pain. No patient was seriously ill, and all recovered without sequelae. Seven different serotypes of non-01 V. cholerae were isolated from the stool specimens, and Smith serotype 12 accounted for 10 (46%) of the 22 isolates. A matched-pair case-control study found that cases were more likely than controls to have eaten home prepared gelatin (P = 0.03, OR = 5/0) and seafood (P = 0.06, OR = 4/0).

  4. [The in vitro action of plants on Vibrio cholerae].

    Science.gov (United States)

    Guevara, J M; Chumpitaz, J; Valencia, E

    1994-01-01

    Natural products of several plants, according to the geographic location, are used by Peruvian people in the popular treatment of diarrhea, with good success. When cholerae cases appeared in Peru, we were interested to know the "in vitro" effect against Vibrio cholerae 01, of these useful plants to treat diarrhea. The following plants were tested: Cichorium intybus, Althaea officinalis, Psorela glandulosa, Geranium maculatum, Punica granatum, Malus sativa, Cydonia oblonga, Chenopodium ambrosoides, Krameria triandria, Tea chinensis, Daucus carota, Persea gratissima, Psidium guayaba and Lippia dulcis. Decoction or infusion of the plants were used in the "in vitro" experiments. The following plants showed no "in vitro" effect against V. cholerae: Cichorium intybus, Althaea officinalis, Psorela glandulosa, Geranium maculatum, Chenopodium ambrosoides, Krameria triandria, Psidium guayaba, Lippia dulcis and Daucus carota. Decoction of Malus sativa and Cydenia oblonga showed bactericidal effect for their acidity and stone avocado (Persea gratissima) a late bactericidal effect. Tea infusión and the decoction of Punica granatum peel, showed the best bactericidal effect and we suggest to use them as to stop cholera spreading.

  5. Vibrio infections among marine and fresh-water fish

    Science.gov (United States)

    1959-01-01

    In 1951. B. J. Earpio found a vibrio infection among salmon fingerlings being reared in saltwater at the Deception Pass Biological Station of the Washington State Department of Fisheries. The disease waa characterized by erythema at the base of fins and on the sides of the fish, necrotic areas in the Inusculature, inflammation of the intestinal tract, and general septicernia. The disease reappeared the next year, killing nearly all of the churn salmon (Oncorhynchus keta) fingerlings, killing about half of the pink salmon (O. gorbuscha) fingerlings, and affecting to a lesser degree the chinook salmon (O. tshawytscha) fingerlings. Also, late in 1952. R. R. Rucker and E. J. Ordal found the same disease at a rainbow trout hatchery of the Washington State Department of Game at Vancouver. The disease caused severe losses there among the rainbow trout (Salmo gairdneri) and among the sea-run form of the same species (called steelhead trout). The disease was manifested by bloody, necrotic areas in the musculature and inflammation of the viscera, відоіШат to furumaculoвiв,

  6. Biosynthesis of myristic acid in luminescent bacteria. [Vibrio harveyi

    Energy Technology Data Exchange (ETDEWEB)

    Byers, D.M.

    1987-05-01

    In vivo pulse-label studies have demonstrated that luminescent bacteria can provide myritic acid (14:0) required for the synthesis of the luciferase substrate myristyl aldehyde. Luminescent wild type Vibrio harveyi incubated with (/sup 14/C) acetate in a nutrient-depleted medium accumulated substantial tree (/sup 14/C)fatty acid (up to 20% of the total lipid label). Radio-gas chromatography revealed that > 75% of the labeled fatty acid is 14:0. No free fatty acid was detected in wild type cells labeled prior to the development of bioluminescence in the exponential growth phase, or in a dark mutant of V. harveyi (mutant M17) that requires exogenous 14:0 for light emission. The preferential accumulation of 14:0 was not observed when wild type cells were labeled with (/sup 14/C)acetate in regular growth medium. Moreover, all V. harveyi strains exhibited similar fatty acid mass compositions regardless of the state of bioluminescence. Since earlier work has shown that a luminescence-related acyltransferase (defective in the M17 mutant) can catalyze the deacylation of fatty acyl-acyl carrier protein in vitro, the present results are consistent with a model in which this enzyme diverts 14:0 to the luminescence system during fatty acid biosynthesis. Under normal conditions, the supply of 14:0 by this pathway is tightly regulated such that bioluminescence development does not significantly alter the total fatty acid composition.

  7. Quorum sensing regulates the osmotic stress response in Vibrio harveyi.

    Science.gov (United States)

    van Kessel, Julia C; Rutherford, Steven T; Cong, Jian-Ping; Quinodoz, Sofia; Healy, James; Bassler, Bonnie L

    2015-01-01

    Bacteria use a chemical communication process called quorum sensing to monitor cell density and to alter behavior in response to fluctuations in population numbers. Previous studies with Vibrio harveyi have shown that LuxR, the master quorum-sensing regulator, activates and represses >600 genes. These include six genes that encode homologs of the Escherichia coli Bet and ProU systems for synthesis and transport, respectively, of glycine betaine, an osmoprotectant used during osmotic stress. Here we show that LuxR activates expression of the glycine betaine operon betIBA-proXWV, which enhances growth recovery under osmotic stress conditions. BetI, an autorepressor of the V. harveyi betIBA-proXWV operon, activates the expression of genes encoding regulatory small RNAs that control quorum-sensing transitions. Connecting quorum-sensing and glycine betaine pathways presumably enables V. harveyi to tune its execution of collective behaviors to its tolerance to stress. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Improved quorum sensing capacity by culturing Vibrio harveyi in microcapsules.

    Science.gov (United States)

    Gao, Meng; Song, Huiyi; Liu, Xiudong; Yu, Weiting; Ma, Xiaojun

    2016-04-01

    Microcapsule entrapped low density cells with culture (ELDCwc), different from free cell culture, conferred stronger stress resistance and improved cell viability of microorganisms. In this paper, the quorum sensing (QS) system of Vibrio harveyi was used to investigate changes when cells were cultured in microcapsules. Cells in ELDCwc group grew into cell aggregates, which facilitated cell-cell communication and led to increased bioluminescence intensity. Moreover, the luxS-AI-2 system, a well-studied QS signal pathway, was detected as both luxS gene and the AI-2 signaling molecule, and the results were analyzed with respect to QS capacity of unit cell. The V. harveyi of ELDCwc also showed higher relative gene expression and stronger quorum sensing capacity when compared with free cells. In conclusion, the confined microcapsule space can promote the cell aggregates formation, reduce cell-cell communication distance and increase local concentration of signal molecule, which are beneficial to bacterial QS. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Heterogeneity in quorum sensing-regulated bioluminescence of Vibrio harveyi.

    Science.gov (United States)

    Anetzberger, Claudia; Pirch, Torsten; Jung, Kirsten

    2009-07-01

    Quorum sensing (QS) refers to the ability of bacterial populations to read out the local environment for cell density and to collectively activate gene expression. Vibrio harveyi, one of the best characterized model organisms in QS, was used to address the question how single cells behave within a QS-activated community in a homogeneous environment. Analysis of the QS-regulated bioluminescence of a wild type strain revealed that even at high cell densities only 69% of the cells of the population produced bioluminescence, 25% remained dark and 6% were dead. Moreover, light intensities greatly varied from cell to cell at high population density. Addition of autoinducer to a bright liquid culture of V. harveyi increased the percentage of luminescent cells up to 98%, suggesting that V. harveyi produces and/or keeps the autoinducers at non-saturating concentrations. In contrast, all living cells of a constitutive QS-active mutant (DeltaluxO) produced light. We also found that QS affects biofilm formation in V. harveyi. Our data provide first evidence that a heterogeneous population produces more biofilm than a homogeneous one. It is suggested that even a QS-committed population of V. harveyi takes advantage of heterogeneity, which extends the current view of QS-regulated uniformity.

  10. Antigenicity analysis of Vibrio harveyi TS-628 strain

    Institute of Scientific and Technical Information of China (English)

    QIN Yingxue; WANG Jun; WANG Shifeng; YAN Qingpi

    2007-01-01

    Vibrio harveyi,the major causative agent of vibriosis,affects a diverse range of marine cultured organisms over a wide geographical area.However,reports about screening the effective antigen and research on vaccines of V.harveyi are scarce.Flagellin,lipopolysaccharide (LPS) and outer membrane proteins (OMP) are major immunogenic antigens in many Gram-negative bacteria.In this study,the flagellin,OMP and LPS of the V.harveyi TS-628 strain isolated from infected groupers were extracted and Western blot analysis was used to detect the antigenicity of these extractions.Results of the Western blot assay reveal that there are four positive flagellin bands:35 kDa,38 kDa,43 kDa,and 52 kDa,of which the 43 kDa and 52 kDa bands displayed the strongest positive reaction.There are five positive OMP bands about 35 kDa,38 kDa,43 kDa,47 kDa,and 52 kDa,of which the 43 kDa appeared to have the strongest positive reaction although the other four proteins also displayed strong reactions.However,LPS is Western blot-negative.These results indicate that the 43 kDa and 52 kDa flagellin and OMP of size 43 kDa,52 kDa can be candidates for developing vaccines against V.harveyi.

  11. Human Gut Microbiota Predicts Susceptibility to Vibrio cholerae Infection.

    Science.gov (United States)

    Midani, Firas S; Weil, Ana A; Chowdhury, Fahima; Begum, Yasmin A; Khan, Ashraful I; Debela, Meti D; Durand, Heather K; Reese, Aspen T; Nimmagadda, Sai N; Silverman, Justin D; Ellis, Crystal N; Ryan, Edward T; Calderwood, Stephen B; Harris, Jason B; Qadri, Firdausi; David, Lawrence A; LaRocque, Regina C

    2018-04-12

    Cholera is a public health problem worldwide and the risk factors for infection are only partially understood. We prospectively studied household contacts of cholera patients to compare those who were infected with those who were not. We constructed predictive machine learning models of susceptibility using baseline gut microbiota data. We identified bacterial taxa associated with susceptibility to Vibrio cholerae infection and tested these taxa for interactions with V. cholerae in vitro. We found that machine learning models based on gut microbiota predicted V. cholerae infection as well as models based on known clinical and epidemiological risk factors. A 'predictive gut microbiota' of roughly 100 bacterial taxa discriminated between contacts who developed infection and those who did not. Susceptibility to cholera was associated with depleted levels of microbes from the phylum Bacteroidetes. By contrast, a microbe associated with cholera by our modeling framework, Paracoccus aminovorans, promoted the in vitro growth of V. cholerae. Gut microbiota structure, clinical outcome, and age were also linked. These findings support the hypothesis that abnormal gut microbial communities are a host factor related to V. cholerae susceptibility.

  12. Systematic analysis of the lysine acetylome in Vibrio parahemolyticus.

    Science.gov (United States)

    Pan, Jianyi; Ye, Zhicang; Cheng, Zhongyi; Peng, Xiaojun; Wen, Liangyou; Zhao, Fukun

    2014-07-03

    Lysine acetylation of proteins is a major post-translational modification that plays an important regulatory role in almost every aspect of cells, both eukaryotes and prokaryotes. Vibrio parahemolyticus, a model marine bacterium, is a worldwide cause of bacterial seafood-borne illness. Here, we conducted the first lysine acetylome in this bacterium through a combination of highly sensitive immune-affinity purification and high-resolution LC-MS/MS. Overall, we identified 1413 lysine acetylation sites in 656 proteins, which account for 13.6% of the total proteins in the cells; this is the highest ratio of acetyl proteins that has so far been identified in bacteria. The bioinformatics analysis of the acetylome showed that the acetylated proteins are involved in a wide range of cellular functions and exhibit diverse subcellular localizations. More specifically, proteins related to protein biosynthesis and carbon metabolism are the preferential targets of lysine acetylation. Moreover, two types of acetylation motifs, a lysine or arginine at the +4/+5 positions and a tyrosine, histidine, or phenylalanine at the +1/+2 positions, were revealed from the analysis of the acetylome. Additionally, protein interaction network analysis demonstrates that a wide range of interactions are modulated by protein acetylation. This study provides a significant beginning for the in-depth exploration of the physiological role of lysine acetylation in V. parahemolyticus.

  13. Metabolic responses of Haliotis diversicolor to Vibrio parahaemolyticus infection.

    Science.gov (United States)

    Lu, Jie; Shi, Yanyan; Cai, Shuhui; Feng, Jianghua

    2017-01-01

    Vibrio parahemolyticus is a devastating bacterial pathogen that often causes outbreak of vibriosis in abalone Haliotis diversicolor. Elucidation of metabolic mechanisms of abalones in responding to V. parahemolyticus infection is essential for controlling the epidemic. In this work, 1 H NMR-based metabolomic techniques along with correlation and network analyses are used to investigate characteristic metabolites, as well as corresponding disturbed pathways in hepatopancreas and gill of H. diversicolor after V. parahemolyticus infection for 48 h. Results indicate that obvious gender- and tissue-specific metabolic responses are induced. Metabolic responses in female abalones are more clearly observed than those in males, which are primarily manifested in the accumulation of branched-chain amino acids and the depletion of organic osmolytes (homarine, betaine and taurine) in the infected gills of female abalones, as well as in the depletion of glutamate, branched-chain and aromatic amino acids in the infected hepatopancreases of female abalones. Moreover, based on major metabolic functions of the characteristic metabolites, we have found that V. parahemolyticus infection not only cause the disturbance in energy metabolism, nucleotide metabolism and osmotic balance, but also induce oxidative stress, immune stress and neurotoxic effect in different tissues with various mechanisms. Our study provides details of metabolic responses of abalones to V. parahemolyticus infection and will shed light on biochemical defence mechanisms of male and female hosts against pathogen infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. A conserved tad pilus promotes Vibrio vulnificus oyster colonization.

    Science.gov (United States)

    Pu, Meng; Duriez, Patrick; Arazi, Mattan; Rowe-Magnus, Dean A

    2018-02-01

    Vibrio vulnificus has the highest death rate (>35%) and per-case economic burden ($3.3 million) of any foodborne pathogen in the United States. Infections occur via open wounds or following ingestion of contaminated seafood, most infamously oysters. We isolated a 1000th generation descendant, designated NT that exhibited increased biofilm and aggregate formation relative to its parent. We identified two significant causal changes underlying these phenotypes. First, the entire 24-kb capsular polysaccharide biosynthesis locus, which is essential for virulence but inhibits biofilm formation, had been purged from the genome. However, NT formed more extensive biofilms and aggregates than a defined cps mutant, suggesting that additional factor(s) contributed to its phenotypes. Second, the expression of a tight adherence (tad) pilus locus was elevated in NT. Deletion of the associated pilin (flp) decreased NT biofilm and aggregate formation. Furthermore, NTΔflp strains were deficient relative to NT in an oyster colonization model, demonstrating a positive correlation between the biofilm and aggregation phenotypes associated with Tad pilus production and efficient bacterial retention by feeding oysters. Despite being widely distributed in the Vibrionaceae, this is the first demonstration of a bona fide physiological role for a Tad pilus in this bacterial family. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. Population dynamics of Vibrio fischeri during infection of Euprymna scolopes.

    Science.gov (United States)

    McCann, Jessica; Stabb, Eric V; Millikan, Deborah S; Ruby, Edward G

    2003-10-01

    The luminous bacterium Vibrio fischeri colonizes a specialized light-emitting organ within its squid host, Euprymna scolopes. Newly hatched juvenile squid must acquire their symbiont from ambient seawater, where the bacteria are present at low concentrations. To understand the population dynamics of V. fischeri during colonization more fully, we used mini-Tn7 transposons to mark bacteria with antibiotic resistance so that the growth of their progeny could be monitored. When grown in culture, there was no detectable metabolic burden on V. fischeri cells carrying the transposon, which inserts in single copy in a specific intergenic region of the V. fischeri genome. Strains marked with mini-Tn7 also appeared to be equivalent to the wild type in their ability to infect and multiply within the host during coinoculation experiments. Studies of the early stages of colonization suggested that only a few bacteria became associated with symbiotic tissue when animals were exposed for a discrete period (3 h) to an inoculum of V. fischeri cells equivalent to natural population levels; nevertheless, all these hosts became infected. When three differentially marked strains of V. fischeri were coincubated with juvenile squid, the number of strains recovered from an individual symbiotic organ was directly dependent on the size of the inoculum. Further, these results indicated that, when exposed to low numbers of V. fischeri, the host may become colonized by only one or a few bacterial cells, suggesting that symbiotic infection is highly efficient.

  16. Antagonism of a (+)N-allylnormetazocine stimulus by (-)PPAP and several structurally related analogs.

    Science.gov (United States)

    Glennon, R A; Young, R; Herndon, J L

    1993-08-01

    Employing rats trained to discriminate 5 mg/kg of the benzomorphan opioid (+)N-allylnormetazocine [(+)NANM] from vehicle, tests of stimulus generalization and antagonism were conducted to determine the influence of several potential sigma-receptor ligands. It has been previously suggested that the (+)NANM stimulus may involve concurrent action at sigma- and phencyclidine (PCP) receptors. Although the low-affinity sigma-antagonist rimcazole was without stimulus-attenuating effect, three novel sigma-ligands--(-)PPAP, CNS 3018, and CNS 3093 (ID50 doses = 3.2, 6.7, and 4.5 mg/kg, respectively)--antagonized the (+)NANM stimulus in a dose-related fashion. The nonselective serotonergic agent 1-(3-trifluoromethyl)phenylpiperazine (TFMPP) produced partial generalization in (+)NANM-trained animals whereas buspirone, a 5-hydroxytryptamine1A (5-HT1A) agonist, attenuated (to 27% drug-appropriate responding) the (+)NANM stimulus. Because the prototypic 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) failed to attenuate the (+)NANM stimulus at pharmacologically relevant doses, it seems unlikely that the (+)NANM stimulus involves a 5-HT1A mechanism. TFMPP and buspirone display modest affinity for sigma-receptors and this may account for the present findings with these agents. The present results neither establish a role for sigma involvement in the stimulus properties of (+)NANM nor eliminate a role for PCP receptors. They do, however, demonstrate that sigma-ligands with little to no affinity for PCP receptors are capable of antagonizing the (+)NANM stimulus.

  17. Alcohol-Induced Impairment of Balance is Antagonized by Energy Drinks.

    Science.gov (United States)

    Marczinski, Cecile A; Fillmore, Mark T; Stamates, Amy L; Maloney, Sarah F

    2018-01-01

    The acute administration of alcohol reliably impairs balance and motor coordination. While it is common for consumers to ingest alcohol with other stimulant drugs (e.g., caffeine, nicotine), little is known whether prototypical alcohol-induced balance impairments are altered by stimulant drugs. The purpose of this study was to examine whether the coadministration of a high-caffeine energy drink with alcohol can antagonize expected alcohol-induced increases in body sway. Sixteen social drinkers (of equal gender) participated in 4 separate double-blind dose administration sessions that involved consumption of alcohol and energy drinks, alone and in combination. Following dose administration, participants completed automated assessments of balance stability (both eyes open and eyes closed) measured using the Biosway Portable Balance System. Participants completed several subjective measures including self-reported ratings of sedation, stimulation, fatigue, and impairment. Blood pressure and pulse rate were recorded repeatedly. The acute administration of alcohol increased body sway, and the coadministration of energy drinks antagonized this impairment. When participants closed their eyes, alcohol-induced body sway was similar whether or not energy drinks were ingested. While alcohol administration increased ratings of sedation and fatigue, energy drink administration increased ratings of stimulation and reduced ratings of fatigue. Modest increases in systolic and diastolic blood pressure following energy drink administration were also observed. Visual assessment of balance impairment is frequently used to indicate that an individual has consumed too much alcohol (e.g., as part of police-standardized field sobriety testing or by a bartender assessing when someone should no longer be served more alcohol). The current findings suggest that energy drinks can antagonize alcohol-induced increases in body sway, indicating that future work is needed to determine whether this

  18. Design of the Magnetic Resonance Imaging Evaluation of Mineralocorticoid Receptor Antagonism in Diabetic Atherosclerosis (MAGMA) Trial.

    Science.gov (United States)

    Rajagopalan, Sanjay; Alaiti, M Amer; Broadwater, Kylene; Goud, Aditya; Gaztanaga, Juan; Connelly, Kim; Fares, Anas; Shirazian, Shayan; Kreatsoulas, Catherine; Farkouh, Michael; Dobre, Mirela; Fink, Jeffrey C; Weir, Matthew R

    2017-09-01

    Mineralocorticoid receptor (MR) activation plays an essential role in promoting inflammation, fibrosis, and target organ damage. Currently, no studies are investigating MR antagonism in patients with type 2 diabetes mellitus (T2DM) with chronic kidney disease, at high risk for cardiovascular complications, who are otherwise not candidates for MR antagonism by virtue of heart failure. Further, there is limited information on candidate therapies that may demonstrate differential benefit from this therapy. We hypothesized that MR antagonism may provide additional protection from atherosclerosis progression in higher-risk patients who otherwise may not be candidates for such a therapeutic approach. In this double-blind, randomized, placebo-controlled trial, subjects with T2DM with chronic kidney disease (≥ stage 3) will be randomized in a 1:1 manner to placebo or spironolactone (12.5 mg with eventual escalation to 25 mg daily over a 4-week period). The co-primary efficacy endpoint will be percentage change in total atheroma volume in thoracic aorta and left ventricular mass at 52 weeks in patients treated with spironolactone vs placebo. Secondary outcomes include 24-hour mean systolic blood pressure, central aortic blood pressure, and insulin resistance (HOMA-IR) at 6 weeks. A novel measure in the study will be changes in candidate miRNAs that regulate expression of NR3C2 (MR gene) as well as measuring monocyte/macrophage polarization in response to therapy with spironolactone. We envision that our strategy of simultaneously probing the effects of a drug combined with analysis of mechanisms of action and predictive response will likely provide key information with which to design event-based trials. © 2017 Wiley Periodicals, Inc.

  19. Detection of Salmonella sp., Vibrio sp. and total plate count bacteria on blood cockle (Anadara granosa)

    Science.gov (United States)

    Ekawati, ER; Yusmiati, S. N. H.

    2018-01-01

    Blood cockle (Anadara granosa) has high level of zinc and protein, which is beneficial for therapeutic function for malnourished particularly stunting case in children. Zinc in animal foods is more absorbable than that from vegetable food. Blood cockle (Anadara granosa) is rich in nutrient and an excellent environment for the growth of microorganisms. This research aimed to identify the contamination of Salmonella sp., Vibrio sp. and total plate count bacteria on blood cockle (Anadara granosa). This was observation research with laboratory analysis. Salmonella sp. and Vibrio sp. were detected from blood cockle. Total plate count was determine of the total amount of the bacteria. Results detected from 20 samples of blood cockle showed that all samples were negative of Salmonella sp. and 1 sample positive Vibrio sp. The result of total plate count bacteria was < 5 x 105 colony/g sample.

  20. Bacterial Seed Endophytes of Domesticated Cucurbits Antagonize Fungal and Oomycete Pathogens Including Powdery Mildew

    Science.gov (United States)

    Khalaf, Eman M.; Raizada, Manish N.

    2018-01-01

    The cucurbit vegetables, including cucumbers, melons and pumpkins, have been cultivated for thousands of years without fungicides. However, their seed germination stage is prone to be infected by soil-borne fungal and oomycete pathogens. Endophytes are symbionts that reside inside plant tissues including seeds. Seed endophytes are founders of the juvenile plant microbiome and can promote host defense at seed germination and later stages. We previously isolated 169 bacterial endophytes associated with seeds of diverse cultivated cucurbits. We hypothesized that these endophytes can antagonize major fungal and oomycete pathogens. Here we tested the endophytes for in vitro antagonism (dual culture assays) against important soil-borne pathogens (Rhizoctonia solani, Fusarium graminearum, Phytophthora capsici, Pythium aphanideratum). The endophytes were also assayed in planta (leaf disk and detached leaf bioassays) for antagonism against a foliar pathogen of global importance, Podosphaera fuliginea, the causative agent of cucurbit powdery mildew. The endophytes were further tested in vitro for secretion of volatile organic compounds (VOCs) known to induce plant defense. Extracellular ribonuclease activity was also tested, as a subset of pathogenesis-related (PR) proteins of plant hosts implicated in suppression of fungal pathogens, displays ribonuclease activity. An unexpected majority of the endophytes (70%, 118/169) exhibited antagonism to the five phytopathogens, of which 68% (50/73) of in vitro antagonists belong to the genera Bacillus and Paenibacillus. All Lactococcus and Pantoea endophytes exhibited anti-oomycete activity. However, amongst the most effective inoculants against Podosphaera fuliginea were Pediococcus and Pantoea endophytes. Interestingly, 67% (113/169) of endophytes emitted host defense inducing VOCs (acetoin/diacetyl) and 62% (104/169) secreted extracellular ribonucleases in vitro, respectively. These results show that seeds of cultivated cucurbits

  1. Bacterial Seed Endophytes of Domesticated Cucurbits Antagonize Fungal and Oomycete Pathogens Including Powdery Mildew

    Directory of Open Access Journals (Sweden)

    Eman M. Khalaf

    2018-02-01

    Full Text Available The cucurbit vegetables, including cucumbers, melons and pumpkins, have been cultivated for thousands of years without fungicides. However, their seed germination stage is prone to be infected by soil-borne fungal and oomycete pathogens. Endophytes are symbionts that reside inside plant tissues including seeds. Seed endophytes are founders of the juvenile plant microbiome and can promote host defense at seed germination and later stages. We previously isolated 169 bacterial endophytes associated with seeds of diverse cultivated cucurbits. We hypothesized that these endophytes can antagonize major fungal and oomycete pathogens. Here we tested the endophytes for in vitro antagonism (dual culture assays against important soil-borne pathogens (Rhizoctonia solani, Fusarium graminearum, Phytophthora capsici, Pythium aphanideratum. The endophytes were also assayed in planta (leaf disk and detached leaf bioassays for antagonism against a foliar pathogen of global importance, Podosphaera fuliginea, the causative agent of cucurbit powdery mildew. The endophytes were further tested in vitro for secretion of volatile organic compounds (VOCs known to induce plant defense. Extracellular ribonuclease activity was also tested, as a subset of pathogenesis-related (PR proteins of plant hosts implicated in suppression of fungal pathogens, displays ribonuclease activity. An unexpected majority of the endophytes (70%, 118/169 exhibited antagonism to the five phytopathogens, of which 68% (50/73 of in vitro antagonists belong to the genera Bacillus and Paenibacillus. All Lactococcus and Pantoea endophytes exhibited anti-oomycete activity. However, amongst the most effective inoculants against Podosphaera fuliginea were Pediococcus and Pantoea endophytes. Interestingly, 67% (113/169 of endophytes emitted host defense inducing VOCs (acetoin/diacetyl and 62% (104/169 secreted extracellular ribonucleases in vitro, respectively. These results show that seeds of cultivated

  2. ANTAGONISM OF PROGESTERONE RECEPTOR SUPPRESSES CAROTID BODY RESPONSES TO HYPOXIA AND NICOTINE IN RAT PUPS

    OpenAIRE

    JOSEPH, V.; NIANE, L. M.; BAIRAM, A.

    2012-01-01

    We tested the hypothesis that antagonism of progesterone receptor (PR) in newborn rats alters carotid body and respiratory responses to hypoxia and nicotinic receptor agonists. Rats were treated with the PR antagonist mifepristone (daily oral gavage 40 μg/g/d) or vehicle between post-natal days 3 and 15. In 11–14-day-old rats, we used in vitro carotid body/carotid sinus nerve preparation and whole body plethysmography to assess the carotid body and ventilatory responses to hypoxia (65 mmHg in...

  3. SPOC1-mediated antiviral host cell response is antagonized early in human adenovirus type 5 infection

    DEFF Research Database (Denmark)

    Schreiner, Sabrina; Kinkley, Sarah; Bürck, Carolin

    2013-01-01

    , and playing a role in DNA damage response. SPOC1 co-localized with viral replication centers in the host cell nucleus, interacted with Ad DNA, and repressed viral gene expression at the transcriptional level. We discovered that this SPOC1-mediated restriction imposed upon Ad growth is relieved by its...... viruses (HSV-1, HSV-2, HIV-1, and HCV) also depleted SPOC1 in infected cells. Our findings provide a general model for how pathogenic human viruses antagonize intrinsic SPOC1-mediated antiviral responses in their host cells. A better understanding of viral entry and early restrictive functions in host...

  4. An effector of the Irish potato famine pathogen antagonizes a host autophagy cargo receptor

    Science.gov (United States)

    Dagdas, Yasin F; Belhaj, Khaoula; Maqbool, Abbas; Chaparro-Garcia, Angela; Pandey, Pooja; Petre, Benjamin; Tabassum, Nadra; Cruz-Mireles, Neftaly; Hughes, Richard K; Sklenar, Jan; Win, Joe; Menke, Frank; Findlay, Kim; Banfield, Mark J; Kamoun, Sophien; Bozkurt, Tolga O

    2016-01-01

    Plants use autophagy to safeguard against infectious diseases. However, how plant pathogens interfere with autophagy-related processes is unknown. Here, we show that PexRD54, an effector from the Irish potato famine pathogen Phytophthora infestans, binds host autophagy protein ATG8CL to stimulate autophagosome formation. PexRD54 depletes the autophagy cargo receptor Joka2 out of ATG8CL complexes and interferes with Joka2's positive effect on pathogen defense. Thus, a plant pathogen effector has evolved to antagonize a host autophagy cargo receptor to counteract host defenses. DOI: http://dx.doi.org/10.7554/eLife.10856.001 PMID:26765567

  5. Bacterial Seed Endophytes of Domesticated Cucurbits Antagonize Fungal and Oomycete Pathogens Including Powdery Mildew

    Directory of Open Access Journals (Sweden)

    Eman M. Khalaf

    2018-02-01

    Full Text Available The cucurbit vegetables, including cucumbers, melons and pumpkins, have been cultivated for thousands of years without fungicides. However, their seed germination stage is prone to be infected by soil-borne fungal and oomycete pathogens. Endophytes are symbionts that reside inside plant tissues including seeds. Seed endophytes are founders of the juvenile plant microbiome and can promote host defense at seed germination and later stages. We previously isolated 169 bacterial endophytes associated with seeds of diverse cultivated cucurbits. We hypothesized that these endophytes can antagonize major fungal and oomycete pathogens. Here we tested the endophytes for in vitro antagonism (dual culture assays against important soil-borne pathogens (Rhizoctonia solani, Fusarium graminearum, Phytophthora capsici, Pythium aphanidermatum. The endophytes were also assayed in planta (leaf disk and detached leaf bioassays for antagonism against a foliar pathogen of global importance, Podosphaera fuliginea, the causative agent of cucurbit powdery mildew. The endophytes were further tested in vitro for secretion of volatile organic compounds (VOCs known to induce plant defense. Extracellular ribonuclease activity was also tested, as a subset of pathogenesis-related (PR proteins of plant hosts implicated in suppression of fungal pathogens, displays ribonuclease activity. An unexpected majority of the endophytes (70%, 118/169 exhibited antagonism to the five phytopathogens, of which 68% (50/73 of in vitro antagonists belong to the genera Bacillus and Paenibacillus. All Lactococcus and Pantoea endophytes exhibited anti-oomycete activity. However, amongst the most effective inoculants against Podosphaera fuliginea were Pediococcus and Pantoea endophytes. Interestingly, 67% (113/169 of endophytes emitted host defense inducing VOCs (acetoin/diacetyl and 62% (104/169 secreted extracellular ribonucleases in vitro, respectively. These results show that seeds of cultivated

  6. Antagonistic effect of Pseudomonas aeruginosa isolates from various ecological niches on Vibrio species pathogenic to crustaceans

    Institute of Scientific and Technical Information of China (English)

    Prabhakaran Priyaja; Puthumana Jayesh; Neil Scolastin Correya; Balachandran Sreelakshmi; Naduthalmuriparambil S Sudheer; Rosamma Philip; Isaac Sarogeni Bright Singh

    2014-01-01

    Objective: To abrogate pathogenic vibrios in aquaculture by testing the potential of Pseudomonas isolates from fresh water, brackish and marine environments as probiotics.Methods:Antagonistic activity of the compound against 7 Vibrio spp. was performed. Influence of salinity on the production of pyocyanin and the toxicity was done through the compound using brine shrimp lethality assay. Molecular characterization was performed to confirm that the isolates werePseudomonas aeruginosa. Results: Salinity was found to regulate the levels of pyocyanin production, with 5-10 g/L as the optimum. All Pseudomonas isolates grew at salinities ranging from 5 to 70 g/L. Isolates of marine origin produced detectable levels of pyocyanin up to 45 g/L salinity. Brackish and freshwater isolates ceased to produce pyocyanin at salinities above 30 g/L and 20 g/L, respectively. Culture supernatants of all 5 Pseudomonas isolates possessed the ability to restrict the growth of Vibrio spp. and maximum antagonistic effect on Vibrio harveyi was obtained when they were grown at salinities of 5 to 10 g/L. The marine isolate MCCB117, even when grown at a salinity of 45 g/L possessed the ability to inhibit Vibrio spp.Conclusions:Purification and structural elucidation of antagonistic compound were carried out. ideal for application in freshwater, MCCB102 and MCCB103 in brackish water and MCCB117 and The present investigation showed that Pseudomonas aeruginosa MCCB119 would be MCCB118 in marine aquaculture systems as putative probiotics in the management of vibrios.

  7. Antagonistic effect of Pseudomonas aeruginosa isolates from various ecological niches on Vibrio species pathogenic to crustaceans

    Directory of Open Access Journals (Sweden)

    Prabhakaran Priyaja

    2014-01-01

    Full Text Available Objective: To abrogate pathogenic vibrios in aquaculture by testing the potential of Pseudomonas isolates from fresh water, brackish and marine environments as probiotics. Methods: Purification and structural elucidation of antagonistic compound were carried out. Antagonistic activity of the compound against 7 Vibrio spp. was performed. Influence of salinity on the production of pyocyanin and the toxicity was done through the compound using brine shrimp lethality assay. Molecular characterization was performed to confirm that the isolates were Pseudomonas aeruginosa. Results: Salinity was found to regulate the levels of pyocyanin production, with 5-10 g/L as the optimum. All Pseudomonas isolates grew at salinities ranging from 5 to 70 g/L. Isolates of marine origin produced detectable levels of pyocyanin up to 45 g/L salinity. Brackish and freshwater isolates ceased to produce pyocyanin at salinities above 30 g/L and 20 g/L, respectively. Culture supernatants of all 5 Pseudomonas isolates possessed the ability to restrict the growth of Vibrio spp. and maximum antagonistic effect on Vibrio harveyi was obtained when they were grown at salinities of 5 to 10 g/L. The marine isolate MCCB117, even when grown at a salinity of 45 g/L possessed the ability to inhibit Vibrio spp. Conclusions: The present investigation showed that Pseudomonas aeruginosa MCCB119 would be ideal for application in freshwater, MCCB102 and MCCB103 in brackish water and MCCB117 and MCCB118 in marine aquaculture systems as putative probiotics in the management of vibrios.

  8. Experimental testing of Mackay's model for functional antagonism in the isolated costo-uterus of the rat.

    Science.gov (United States)

    Henry, P. J.; Lulich, K. M.; Paterson, J. W.

    1985-01-01

    Several key predictions of a recently developed model for functional antagonism (Mackay, 1981) were experimentally tested using the rat isolated costo-uterine preparation. In the presence of the functional antagonist fenoterol (Fen), the functional constants (KAF) for carbachol and oxotremorine (Oxo) were respectively 9.9 and 3.4 fold greater than their corresponding affinity constants (KA). According to Mackay's model for functional antagonism, the higher KAF/KA ratio for carbachol indicates that this cholinoceptor agonist has a greater efficacy than Oxo. This was confirmed by using conventional pharmacological methods. As predicted from the model of functional antagonism, the plot of KAF/KA-1 against the fraction of cholinoceptors not irreversibly blocked by phenoxybenzamine (Pbz) was linear for both carbachol and Oxo and the lines of best fit crossed the axes at a point not significantly different from the origin. The value of 4.6 for the relative efficacy of carbachol to Oxo estimated from functional antagonism studies was comparable to the value of 5.6 calculated using the method of irreversible antagonism proposed by Furchgott (1966). PMID:3840396

  9. Sexual antagonism and meiotic drive cause stable linkage disequilibrium and favour reduced recombination on the X chromosome.

    Science.gov (United States)

    Rydzewski, W T; Carioscia, S A; Liévano, G; Lynch, V D; Patten, M M

    2016-06-01

    Sexual antagonism and meiotic drive are sex-specific evolutionary forces with the potential to shape genomic architecture. Previous theory has found that pairing two sexually antagonistic loci or combining sexual antagonism with meiotic drive at linked autosomal loci augments genetic variation, produces stable linkage disequilibrium (LD) and favours reduced recombination. However, the influence of these two forces has not been examined on the X chromosome, which is thought to be enriched for sexual antagonism and meiotic drive. We investigate the evolution of the X chromosome under both sexual antagonism and meiotic drive with two models: in one, both loci experience sexual antagonism; in the other, we pair a meiotic drive locus with a sexually antagonistic locus. We find that LD arises between the two loci in both models, even when the two loci freely recombine in females and that driving haplotypes will be enriched for male-beneficial alleles, further skewing sex ratios in these populations. We introduce a new measure of LD, Dz', which accounts for population allele frequencies and is appropriate for instances where these are sex specific. Both models demonstrate that natural selection favours modifiers that reduce the recombination rate. These results inform observed patterns of congealment found on driving X chromosomes and have implications for patterns of natural variation and the evolution of recombination rates on the X chromosome. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  10. Occurrence of Vibrio parahaemolyticus and Vibrio vulnificus in retail raw oysters from the eastern coast of Thailand.

    Science.gov (United States)

    Changchai, Nuttawee; Saunjit, Sudarat

    2014-05-01

    Occurrence, population density and virulence of Vibrio parahaemolyticus and V. vulnificus in 240 retail raw oysters collected monthly between March 2010 and February 2011 from Ang Sila coast, Chon Buri Province, Thailand were determined using most probable number (MPN) multiplex PCR. Multiplex PCR detected V. parahaemolyticus in 219 raw oyster samples, of which 29 samples contained the virulence tdh. MPN values for V. parahaemolyticus and pathogenic strains in most samples ranged from 10 to 10(2) and from 3 to 10 MPN/g, respectively. The presence of V. vulnificus was found in 53 oyster samples in amounts between 10 and 10(2) MPN/g. Of 1,087 V. parahaemolyticus isolates, 14 and 2 isolates carried tdh and virulence trh, respectively but none with both genes. However, none of the presumptive isolates was shown to be V. vulnificus. The detection of pathogenic V. parahaemolyticus and V. vulnificus in raw oysters has rendered high awareness of risk in consumption of raw or undercooked oysters.

  11. Antagonism by hemoglobin of effects induced by L-arginine in neuromuscular preparations from rats

    Directory of Open Access Journals (Sweden)

    C.R. Ambiel

    2001-04-01

    Full Text Available Nitric oxide (NO-synthase is present in diaphragm, phrenic nerve and vascular smooth muscle. It has been shown that the NO precursor L-arginine (L-Arg at the presynaptic level increases the amplitude of muscular contraction (AMC and induces tetanic fade when the muscle is indirectly stimulated at low and high frequencies, respectively. However, the precursor in muscle reduces AMC and maximal tetanic fade when the preparations are stimulated directly. In the present study the importance of NO synthesized in different tissues for the L-Arg-induced neuromuscular effects was investigated. Hemoglobin (50 nM did not produce any neuromuscular effect, but antagonized the increase in AMC and tetanic fade induced by L-Arg (9.4 mM in rat phrenic nerve-diaphragm preparations. D-Arg (9.4 mM did not produce any effect when preparations were stimulated indirectly at low or high frequency. Hemoglobin did not inhibit the decrease of AMC or the reduction in maximal tetanic tension induced by L-Arg in preparations previously paralyzed with d-tubocurarine and directly stimulated. Since only the presynaptic effects induced by L-Arg were antagonized by hemoglobin, the present results suggest that NO synthesized in muscle acts on nerve and skeletal muscle. Nevertheless, NO produced in nerve and vascular smooth muscle does not seem to act on skeletal muscle.

  12. IFITM Proteins Restrict HIV-1 Infection by Antagonizing the Envelope Glycoprotein

    Directory of Open Access Journals (Sweden)

    Jingyou Yu

    2015-10-01

    Full Text Available The interferon-induced transmembrane (IFITM proteins have been recently shown to restrict HIV-1 and other viruses. Here, we provide evidence that IFITM proteins, particularly IFITM2 and IFITM3, specifically antagonize the HIV-1 envelope glycoprotein (Env, thereby inhibiting viral infection. IFITM proteins interact with HIV-1 Env in viral producer cells, leading to impaired Env processing and virion incorporation. Notably, the level of IFITM incorporation into HIV-1 virions does not strictly correlate with the extent of inhibition. Prolonged passage of HIV-1 in IFITM-expressing T lymphocytes leads to emergence of Env mutants that overcome IFITM restriction. The ability of IFITMs to inhibit cell-to-cell infection can be extended to HIV-1 primary isolates, HIV-2 and SIVs; however, the extent of inhibition appears to be virus-strain dependent. Overall, our study uncovers a mechanism by which IFITM proteins specifically antagonize HIV-1 Env to restrict HIV-1 infection and provides insight into the specialized role of IFITMs in HIV infection.

  13. Analysis of agonist dissociation constants as assessed by functional antagonism in guinea pig left atria

    International Nuclear Information System (INIS)

    Molenaar, P.; Malta, E.

    1986-01-01

    In electrically driven guinea pig left atria, positive inotropic responses to (-)-isoprenaline and the selective beta 1-adrenoceptor agonist RO363 were obtained in the absence and in the presence of the functional antagonists adenosine, carbachol, gallopamil, nifedipine, and Ro 03-7894. Each of the functional antagonists reduced the maximum response to both agonists and produced nonparallel rightward shifts in the cumulative concentration effect curves. For both agonists, dissociation constants (KA) were calculated using the equation described by Furchgott (1966) for irreversible antagonism. For RO363, which is a partial agonist with high agonist activity, the equations outlined for functional interaction by Mackay (1981) were also employed to calculate KA values. The KA values obtained by each method were compared with the dissociation constants (KD) for the two agonists determined from their ability to displace the radioligand (-)-[ 125 I]iodocyanopindolol from beta 1-adrenoceptors in guinea pig left atrial membrane preparations. The estimates of KA varied substantially from KD values. The KD values were taken as more accurate estimates of the true values for the dissociation constants because a high degree of correlation exists between pKD and pD2 values for a number of other beta-adrenoceptor agonists that behave as partial agonists and between pKD and pKB values for a number of beta-adrenoceptor antagonists. Thus, it appears that there are serious limitations in the current theory for using functional antagonism as a means of obtaining agonist dissociation constants

  14. Antagonism of Trichoderma harzianum ETS 323 on Botrytis cinerea mycelium in culture conditions.

    Science.gov (United States)

    Cheng, Chi-Hua; Yang, Chia-Ann; Peng, Kou-Cheng

    2012-11-01

    ABSTRACT Previous studies have shown that the extracellular proteins of Trichoderma harzianum ETS 323 grown in the presence of deactivated Botrytis cinerea in culture include a putative l-amino acid oxidase and have suggested the involvement of this enzyme in the antagonistic mechanism. Here, we hypothesized that the mycoparasitic process of Trichoderma spp. against B. cinerea involves two steps; that is, an initial hyphal coiling stage and a subsequent hyphal coiling stage, with different coiling rates. The two-step antagonism of T. harzianum ETS 323 against B. cinerea during the mycoparasitic process in culture was evaluated using a biexponential equation. In addition, an l-amino acid oxidase (Th-l-AAO) was identified from T. harzianum ETS 323. The secretion of Th-l-AAO was increased when T. harzianum ETS 323 was grown with deactivated hyphae of B. cinerea. Moreover, in vitro assays indicated that Th-l-AAO effectively inhibited B. cinerea hyphal growth, caused cytosolic vacuolization in the hyphae, and led to hyphal lysis. Th-l-AAO also showed disease control against the development of B. cinerea on postharvest apple fruit and tobacco leaves. Furthermore, an apoptosis-like response, including the generation of reactive oxygen species, was observed in B. cinerea after treatment with Th-l-AAO, suggesting that Th-l-AAO triggers programmed cell death in B. cinerea. This may be associated with the two-step antagonism of T. harzianum ETS 323 against B. cinerea.

  15. Effect of endothelin antagonism on apnea frequency following chronic intermittent hypoxia.

    Science.gov (United States)

    Donovan, Lucas M; Liu, Yuzhen; Weiss, J Woodrow

    2014-04-01

    Chronic hypoxia increases the hypoxic ventilatory response (HVR). Augmented HVR contributes to central apneas seen in heart failure and complex sleep apnea. Endothelin receptor (ETR) antagonism decreases carotid body afferent activity following chronic intermittent hypoxia (CIH). We speculated ETR antagonism would reduce HVR and apneas following CIH. HVR and apneas were measured after exposure to CIH and room air sham (SHAM). ETR blocker Ambrisentan was administered via the chow of CIH-exposed animals from days 1 to 12 of CIH (CIH/AMB). A separate crossover group was exposed to CIH and fed normal chow (placebo) days 1-6, and Ambrisentan days 7-12 (CIH/PLA-AMB). SHAM and CIH/PLA animals were fed placebo days 1-12. The CIH/AMB and CIH/PLA-AMB rats had reduced HVR compared to CIH/PLA, similar HVR compared to sham exposed animals, and reduced apnea frequency compared to CIH/PLA animals. The reduced HVR and post-hypoxic apneas resulting from Ambrisentan administration suggests ETR antagonists may have utility in reducing central apneas following CIH. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Dynamical transitions in a pollination-herbivory interaction: a conflict between mutualism and antagonism.

    Directory of Open Access Journals (Sweden)

    Tomás A Revilla

    Full Text Available Plant-pollinator associations are often seen as purely mutualistic, while in reality they can be more complex. Indeed they may also display a diverse array of antagonistic interactions, such as competition and victim-exploiter interactions. In some cases mutualistic and antagonistic interactions are carried-out by the same species but at different life-stages. As a consequence, population structure affects the balance of inter-specific associations, a topic that is receiving increased attention. In this paper, we developed a model that captures the basic features of the interaction between a flowering plant and an insect with a larval stage that feeds on the plant's vegetative tissues (e.g. leaves and an adult pollinator stage. Our model is able to display a rich set of dynamics, the most remarkable of which involves victim-exploiter oscillations that allow plants to attain abundances above their carrying capacities and the periodic alternation between states dominated by mutualism or antagonism. Our study indicates that changes in the insect's life cycle can modify the balance between mutualism and antagonism, causing important qualitative changes in the interaction dynamics. These changes in the life cycle could be caused by a variety of external drivers, such as temperature, plant nutrients, pesticides and changes in the diet of adult pollinators.

  17. Benzodiazepine antagonism by harmane and other beta-carbolines in vitro and in vivo.

    Science.gov (United States)

    Rommelspacher, H; Nanz, C; Borbe, H O; Fehske, K J; Müller, W E; Wollert, U

    1981-03-26

    Harmane and other related beta-carbolines are putative endogenous ligands of the benzodiazepine receptor. Since the compounds are potent convulsants they may have agonist activities at the benzodiazepine receptor while the benzodiazepines may be antagonists. This hypothesis was proved by comparing the in vivo and in vitro antagonism of benzodiazepines by harmane and other beta-carbolines. Harmane is clearly a competitive inhibitor of benzodiazepine receptor binding in vitro. Moreover, harmane-induced convulsions can be inhibited reversibly by diazepam in a manner which is consistent with the assumption of competitive antagonism in vivo. For some beta-carboline derivatives a correlation was found between the affinity for the benzodiazepine receptor in vitro and the convulsive potency in vivo. Thus, the data reported suggest that harmane or other related beta-carbolines are putative endogenous agonists of the benzodiazepine receptor. This suggestion is further supported by the observation that diazepam is equally potent in inhibiting harmane- or picrotoxin-induced convulsions, indicating a convulsive mechanism within the GABA receptor-benzodiazepine receptor system.

  18. FCJ-156 Hacking the Social: Internet Memes, Identity Antagonism, and the Logic of Lulz.

    Directory of Open Access Journals (Sweden)

    Ryan M. Milner

    2013-12-01

    Full Text Available 4chan and reddit are participatory media collectives undergirded by a “logic of lulz” that favours distanced irony and critique. It often works at the expense of core identity categories like race and gender. However, the logic need not be entirely counterproductive to public discourse. Provided that diverse identities find voice instead of exclusion, these sites may facilitate vibrant, agonistic discussion instead of disenfranchising antagonism. In order to assess this potential for productive agonism, I undertook a critical discourse analysis of these collectives. Emphasising the image memes they produce, I evaluated discourses on race and gender. Both race and gender representations were dominated by familiar stereotypes and partial representations. However, while dissenting perspectives on race were repressed or excluded, dissenting perspectives on gender were vocalised and contested. The ‘logic of lulz’ facilitated both dominance and counter, each articulated with heavy reliance on irony and critique. This logic ambiguously balanced agonism and antagonism, but contestation provided sharper engagement than repression.

  19. Antagonism between abscisic acid and gibberellins is partially mediated by ascorbic acid during seed germination in rice.

    Science.gov (United States)

    Ye, Nenghui; Zhang, Jianhua

    2012-05-01

    The antagonism between abscisic acid (ABA) and gibberellin (GA) plays a key role in controlling seed germination, but the mechanism of antagonism during this process is not known. In the associated study, we investigated the relationship among ABA, reactive oxygen species (ROS), ascorbic acid (ASC) and GA during rice seed germination. ROS production is reduced by ABA, which hence results in decreasing ASC accumulation during imbibition. GA accumulation was also suppressed by a reduced ROS and ASC level, whereas application of exogenous ASC can partially rescue seed germination from ABA treatment. Further results show that production of ASC, which acts as a substrate in GA biosynthesis, was significantly inhibited by lycorine which thus suppressed the accumulation of GA. Consequently, expression of GA biosynthesis genes was suppressed by the low levels of ROS and ASC in ABA-treated seeds. These studies reveal a new role for ASC in mediating the antagonism between ABA and GA during seed germination in rice.

  20. Progranulin shows cytoprotective effects on trophoblast cells in vitro but does not antagonize TNF-α-induced apoptosis.

    Science.gov (United States)

    Stubert, Johannes; Waldmann, Kathrin; Dieterich, Max; Richter, Dagmar-Ulrike; Briese, Volker

    2014-11-01

    The glycoprotein progranulin directly binds to TNF-receptors and thereby can antagonize the inflammatory effects of TNF-α. Here we analyzed the impact of both cytokines on cytotoxicity and viability of trophoblast cells. Isolated villous first trimester human trophoblast cells and the human choriocarcinoma cell line BeWo were treated with recombinant human progranulin and TNF-α. Analyses were performed by LDH- and MTT-assay and measurement of caspase-8-activity. Progranulin treatment showed some cytoprotective effects on isolated trophoblast cells. However, TNF-α-induced apoptosis was not antagonized by addition of progranulin. Effects were similar, but more pronounced in BeWo cells. The cytoprotective activity of progranulin on trophoblast cells in vitro was only weak and of doubtful biologic relevance. It was not able to antagonize TNF-α. Future studies should focus on possible paracrine activities of progranulin.

  1. Aggression, Sibling Antagonism, and Theory-of-Mind During the First Year of Siblinghood: A Developmental Cascade Model

    Science.gov (United States)

    Song, Ju-Hyun; Volling, Brenda L.; Lane, Jonathan D.; Wellman, Henry M.

    2016-01-01

    A developmental cascade model was tested to examine longitudinal associations among firstborn children’s aggression, Theory-of-Mind, and antagonism toward their younger sibling during the first year of siblinghood. Aggression and Theory-of-Mind were assessed before the birth of a sibling, and 4 and 12 months after the birth, and antagonism was examined at 4 and 12 months in a sample of 208 firstborn children (initial M age = 30 months, 56% girls) from primarily European American, middle- class families. Firstborns’ aggression consistently predicted high sibling antagonism both directly and through poorer Theory-of-Mind. Results highlight the importance of examining longitudinal influences across behavioral, social-cognitive, and relational factors that are closely intertwined even from the early years of life. PMID:27096923

  2. Unexpected photoreactivation of Vibrio harveyi bacteria living in ionization environment

    International Nuclear Information System (INIS)

    Alifano, P.; Tala, A.; Tredici, S. M.; Nassisi, V.; Siciliano, M. V.

    2011-01-01

    Bacteria undergoing environmental effects is extremely interesting for structural, mechanistic, and evolutionary implications. Luminescent bacteria that have evolved in a specific ambient have developed particular responses and their behavior can give us new suggestions on the task and production of luciferina proteins. To analyze the UV interaction under controlled laboratory conditions, we used photoluminescent bacterial strains belonging to a new species evolutionarily close to Vibrio harveyi sampled from a coastal cave with a high radon content that generates ionizing radiation. The survival of the bacterial strains was analyzed, in the light and in the dark, following a variety of genotoxic treatments including UV radiation exposure. The strains were irradiated by a germicide lamp. The results demonstrated that most of the strains exhibited a low rate of survival after the UV exposure. After irradiation by visible light following the UV exposure, all strains showed a high capability of photoreactivation when grown. This capability was quite unexpected because these bacteria were sampled from a dark ambient without UV radiation. This leads us to hypothesize that the photoreactivation in these bacteria might have been evolved to repair DNA lesions also induced by different radiation sources other than UV (e.g., x-ray) and that the luminescent bacteria might use their own light emission to carry out the photoreactivation. The high capability of photoreactivation of these bacteria was also justified by the results of deconvolution. The deconvolution was applied to the emission spectra and it was able to show evidence of different light peaks. The presence of the visible peak could control the photolysis enzyme.

  3. Vibrio cholerae classical biotype strains reveal distinct signatures in Mexico.

    Science.gov (United States)

    Alam, Munirul; Islam, M Tarequl; Rashed, Shah Manzur; Johura, Fatema-tuz; Bhuiyan, Nurul A; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Hasan, Nur-A; Colwell, Rita R; Cravioto, Alejandro

    2012-07-01

    Vibrio cholerae O1 classical (CL) biotype caused the fifth and sixth pandemics, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the seventh pandemic in Asia in the 1970s by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia and although it had never been reported from Latin America, V. cholerae CL and ET biotypes, including a hybrid ET, were found associated with areas of cholera endemicity in Mexico between 1991 and 1997. In this study, CL biotype strains isolated from areas of cholera endemicity in Mexico between 1983 and 1997 were characterized in terms of major phenotypic and genetic traits and compared with CL biotype strains isolated in Bangladesh between 1962 and 1989. According to sero- and biotyping data, all V. cholerae strains tested had the major phenotypic and genotypic characteristics specific for the CL biotype. Antibiograms revealed the majority of the Bangladeshi strains to be resistant to trimethoprim-sulfamethoxazole, furazolidone, ampicillin, and gentamicin, while the Mexican strains were sensitive to all of these drugs, as well as to ciprofloxacin, erythromycin, and tetracycline. Pulsed-field gel electrophoresis (PFGE) of NotI-digested genomic DNA revealed characteristic banding patterns for all of the CL biotype strains although the Mexican strains differed from the Bangladeshi strains in 1 to 2 DNA bands. The difference was subtle but consistent, as confirmed by the subclustering patterns in the PFGE-based dendrogram, and can serve as a regional signature, suggesting the pre-1991 existence and evolution of the CL biotype strains in the Americas, independent from Asia.

  4. Structural requirements of cholesterol for binding to Vibrio cholerae hemolysin.

    Science.gov (United States)

    Ikigai, Hajime; Otsuru, Hiroshi; Yamamoto, Koichiro; Shimamura, Tadakatsu

    2006-01-01

    Cholesterol is necessary for the conversion of Vibrio cholerae hemolysin (VCH) monomers into oligomers in liposome membranes. Using different sterols, we determined the stereochemical structures of the VCH-binding active groups present in cholesterol. The VCH monomers are bound to cholesterol, diosgenin, campesterol, and ergosterol, which have a hydroxyl group at position C-3 (3betaOH) in the A ring and a C-C double bond between positions C-5 and C-6 (C-C Delta(5)) in the B ring. They are not bound to epicholesterol and dihydrocholesterol, which form a covalent link with a 3alphaOH group and a C-C single bond between positions C-5 and C-6, respectively. This result suggests that the 3betaOH group and the C-CDelta(5) bond in cholesterol are required for VCH monomer binding. We further examined VCH oligomer binding to cholesterol. However, this oligomer did not bind to cholesterol, suggesting that the disappearance of the cholesterol-binding potential of the VCH oligomer might be a result of the conformational change caused by the conversion of the monomer into the oligomer. VCH oligomer formation was observed in liposomes containing sterols with the 3betaOH group and the C-C Delta(5) bond, and it correlated with the binding affinity of the monomer to each sterol. Therefore, it seems likely that monomer binding to membrane sterol leads to the assembly of the monomer. However, since oligomer formation was induced by liposomes containing either epicholesterol or dihydrocholesterol, the 3betaOH group and the C-C Delta(5) bond were not essential for conversion into the oligomer.

  5. Bacteroides species produce Vibrio harveyi autoinducer 2-related molecules.

    Science.gov (United States)

    Antunes, Luis Caetano Martha; Ferreira, Lívia Queiroz; Ferreira, Eliane Oliveira; Miranda, Karla Rodrigues; Avelar, Kátia Eliane Santos; Domingues, Regina Maria Cavalcanti Pilotto; Ferreira, Maria Candida de Souza

    2005-10-01

    Quorum sensing is a density-dependent gene regulation mechanism that has been described in many bacterial species in the last decades. Bacteria that use quorum sensing as part of their gene regulation circuits produce molecules called autoinducers that accumulate in the environment and activate target genes in a quorum-dependent way. Some specific clues led us to hypothesize that Bacteroides species can produce autoinducers and possess a quorum sensing system. First, Bacteroides are anaerobic bacteria that are frequently involved in polymicrobial infections. These infections often involve Pseudomonas aeruginosa and Staphylococcus aureus, two of the best understood examples of bacteria that employ quorum sensing systems as part of their pathogenesis. Also, studies have detected the presence of a quorum sensing gene involved in the production of autoinducers in Porphyromonas gingivalis, a species closely related to the Bacteroides genus. These and other evidences prompted us to investigate if Bacteroides strains could produce autoinducer molecules that could be detected by a Vibrio harveyi reporter system. In this paper, we show that supernatants of B. fragilis, B. vulgatus and B. distasonis strains are able to stimulate the V. harveyi quorum sensing system 2. Also, we were able to demonstrate that the stimulation detected is due to the production of autoinducer molecules and not the growth of reporter strains after addition of supernatant. Moreover, the phenomenon observed does not seem to represent the degradation of repressors possibly present in the culture medium used. We could also amplify bands from some of the strains tested using primers designed to the luxS gene of Escherichia coli. Altogether, our results show that B. fragilis, B. vulgatus and B. distasonis (but possibly some other species) can produce V. harveyi autoinducer 2-related molecules. However, the role of such molecules in the biology of these organisms remains unknown.

  6. Genome assortment, not serogroup, defines Vibrio cholerae pandemic strains

    Energy Technology Data Exchange (ETDEWEB)

    Brettin, Thomas S [Los Alamos National Laboratory; Bruce, David C [Los Alamos National Laboratory; Challacombe, Jean F [Los Alamos National Laboratory; Detter, John C [Los Alamos National Laboratory; Han, Cliff S [Los Alamos National Laboratory; Munik, A C [Los Alamos National Laboratory; Chertkov, Olga [Los Alamos National Laboratory; Meincke, Linda [Los Alamos National Laboratory; Saunders, Elizabeth [Los Alamos National Laboratory; Choi, Seon Y [SEOUL NATL. UNIV.; Haley, Bradd J [U. MARYLAND; Taviani, Elisa [U. MARYLAND; Jeon, Yoon - Seong [INTL. VACCINE INST. SEOUL; Kim, Dong Wook [INTL. VACCINE INST. SEOUL; Lee, Jae - Hak [SEOUL NATL. UNIV.; Walters, Ronald A [PNNL; Hug, Anwar [NATL. INST. CHOLERIC ENTERIC DIS.; Colwell, Rita R [U. MARYLAND

    2009-01-01

    Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the 6th and the current 7th pandemics, respectively. Cholera researchers continually face newly emerging and re-emerging pathogenic clones carrying combinations of new serogroups as well as of phenotypic and genotypic properties. These genotype and phenotype changes have hampered control of the disease. Here we compare the complete genome sequences of 23 strains of V. cholerae isolated from a variety of sources and geographical locations over the past 98 years in an effort to elucidate the evolutionary mechanisms governing genetic diversity and genesis of new pathogenic clones. The genome-based phylogeny revealed 12 distinct V. cholerae phyletic lineages, of which one, designated the V. cholerae core genome (CG), comprises both O1 classical and EI Tor biotypes. All 7th pandemic clones share nearly identical gene content, i.e., the same genome backbone. The transition from 6th to 7th pandemic strains is defined here as a 'shift' between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages within the CG clade. In contrast, transition among clones during the present 7th pandemic period can be characterized as a 'drift' between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V.cholerae serogroup O139 and V.cholerae O1 El Tor hybrid clones that produce cholera toxin of classical biotype. Based on the comprehensive comparative genomics presented in this study it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to

  7. Luciferase inactivation in the luminous marine bacterium Vibrio harveyi.

    Science.gov (United States)

    Reeve, C A; Baldwin, T O

    1981-06-01

    Luciferase was rapidly inactivated in stationary-phase cultures of the wild type of the luminous marine bacterium Vibrio harveyi, but was stable in stationary-phase cultures of mutants of V. harveyi that are nonluminous without exogenous aldehyde, termed the aldehyde-deficient mutants. The inactivation in the wild type was halted by cell lysis and was slowed or stopped by O2 deprivation or by addition of KCN and NaF or of chloramphenicol. If KCN and NaF or chloramphenicol were added to a culture before the onset of luciferase inactivation, then luciferase inactivation did not occur. However, if these inhibitors were added after the onset of luciferase inactivation, then luciferase inactivation continued for about 2 to 3 h before the inactivation process stopped. The onset of luciferase inactivation in early stationary-phase cultures of wild-type cell coincided with a slight drop in the intracellular adenosine 5'-triphosphate (ATP) level from a relatively constant log-phase value of 20 pmol of ATP per microgram of soluble cell protein. Addition of KCN and NaF to a culture shortly after this drop in ATP caused a rapid decrease in the ATP level to about 4 pmol of ATP per microgram whereas chloramphenicol added at this same time caused a transient increase in ATP level to about 25 pmol/microgram. The aldehyde-deficient mutant (M17) showed a relatively constant log-phase ATP level identical with that of the wild-type cells, but rather than decreasing in early stationary phase, the ATP level increased to a value twice that in log-phase cells. We suggest that the inactivation of luciferase is dependent on the synthesis of some factor which is produced during stationary phase and is itself unstable, and whose synthesis is blocked by chloramphenicol or cyanide plus fluoride.

  8. Vibrio cholerae Infection of Drosophilamelanogaster Mimics the Human Disease Cholera.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available Cholera, the pandemic diarrheal disease caused by the gram-negative bacterium Vibrio cholerae, continues to be a major public health challenge in the developing world. Cholera toxin, which is responsible for the voluminous stools of cholera, causes constitutive activation of adenylyl cyclase, resulting in the export of ions into the intestinal lumen. Environmental studies have demonstrated a close association between V. cholerae and many species of arthropods including insects. Here we report the susceptibility of the fruit fly, Drosophila melanogaster, to oral V. cholerae infection through a process that exhibits many of the hallmarks of human disease: (i death of the fly is dependent on the presence of cholera toxin and is preceded by rapid weight loss; (ii flies harboring mutant alleles of either adenylyl cyclase, Gsalpha, or the Gardos K channel homolog SK are resistant to V. cholerae infection; and (iii ingestion of a K channel blocker along with V. cholerae protects wild-type flies against death. In mammals, ingestion of as little as 25 mug of cholera toxin results in massive diarrhea. In contrast, we found that ingestion of cholera toxin was not lethal to the fly. However, when cholera toxin was co-administered with a pathogenic strain of V. cholerae carrying a chromosomal deletion of the genes encoding cholera toxin, death of the fly ensued. These findings suggest that additional virulence factors are required for intoxication of the fly that may not be essential for intoxication of mammals. Furthermore, we demonstrate for the first time the mechanism of action of cholera toxin in a whole organism and the utility of D. melanogaster as an accurate, inexpensive model for elucidation of host susceptibility to cholera.

  9. Vibrio Parahemolyticus in the Wastewater of Kermanshah City

    OpenAIRE

    Ali Almasi; Mohammad Soltanian; Feizollah Mansoori; Mohammad Taghi Aivazy; Parviz Mohajeri; Habibeh Meskini

    2005-01-01

    آب و فاضلاب                                                                                                                                                                                                               شماره 51- سال 1383     Municipal wastewater is one of the most important pollution sources for water supply resources. Soil, vegetable, and food material are exposed as well. Identification and enumeration of pathogenic agents particularly pathogenic Vibrios a...

  10. Modeling Transfer of Vibrio Parahaemolyticus During Peeling of Raw Shrimp.

    Science.gov (United States)

    Xiao, Xingning; Pang, Haiying; Wang, Wen; Fang, Weihuan; Fu, Yingchun; Li, Yanbin

    2018-03-01

    This study aimed to qualify the transfer of Vibrio parahaemolyticus during the shrimp peeling process via gloves under 3 different scenarios. The 1st 2 scenarios provided quantitative information for the probability distribution of bacterial transfer rates from (i) contaminated shrimp (6 log CFU/g) to non-contaminated gloves (Scenario 1) and (ii) contaminated gloves (6 log CFU/per pair) to non-contaminated shrimp (Scenario 2). In Scenario 3, bacterial transfer from contaminated shrimp to non-contaminated shrimp in the shrimp peeling process via gloves was investigated to develop a predictive model for describing the successive bacterial transfer. The range of bacterial transfer rate (%) in Scenarios 1 and 2 was 7% to 91.95% and 0.04% to 12.87%, respectively, indicating that the bacteria can be transferred from shrimp to gloves much easier than that from gloves to shrimp. A Logistic (1.59, 0.14) and Triangle distribution (-1.61, 0.12, 1.32) could be used to describe the bacterial transfer rate in Scenarios 1 and 2, respectively. In Scenario 3, a continuously decay patterning with fluctuations as the peeling progressed has been observed at all inoculation levels of the 1st shrimp (5, 6, and 7 log CFU/g). The bacteria could be transferred easier at 1st few peels, and the decreasing bacterial transfer was found in later phase. Two models (exponential and Weibull) could describe the successive bacterial transfer satisfactorily (pseudo-R 2 > 0.84, RMSE peeling process. The bacterial transfer rate distribution and predictive model derived from this work could be used in risk assessment of V. parahaemolyticus to ensure peeled shrimp safety. © 2018 Institute of Food Technologists®.

  11. Symbiont interactions in a tripartite mutualism: exploring the presence and impact of antagonism between two fungus-growing ant mutualists.

    Directory of Open Access Journals (Sweden)

    Michael Poulsen

    Full Text Available Mutualistic associations are shaped by the interplay of cooperation and conflict among the partners involved, and it is becoming increasingly clear that within many mutualisms multiple partners simultaneously engage in beneficial interactions. Consequently, a more complete understanding of the dynamics within multipartite mutualism communities is essential for understanding the origin, specificity, and stability of mutualisms. Fungus-growing ants cultivate fungi for food and maintain antibiotic-producing Pseudonocardia actinobacteria on their cuticle that help defend the cultivar fungus from specialized parasites. Within both ant-fungus and ant-bacterium mutualisms, mixing of genetically distinct strains can lead to antagonistic interactions (i.e., competitive conflict, which may prevent the ants from rearing multiple strains of either of the mutualistic symbionts within individual colonies. The success of different ant-cultivar-bacterium combinations could ultimately be governed by antagonistic interactions between the two mutualists, either as inhibition of the cultivar by Pseudonocardia or vice versa. Here we explore cultivar-Pseudonocardia antagonism by evaluating in vitro interactions between strains of the two mutualists, and find frequent antagonistic interactions both from cultivars towards Pseudonocardia and vice versa. To test whether such in vitro antagonistic interactions affect ant colonies in vivo, we performed sub-colony experiments using species of Acromyrmex leaf-cutting ants. We created novel ant-fungus-bacterium pairings in which there was antagonism from one, both, or neither of the ants' microbial mutualists, and evaluated the effect of directional antagonism on cultivar biomass and Pseudonocardia abundance on the cuticle of workers within sub-colonies. Despite the presence of frequent in vitro growth suppression between cultivars and Pseudonocardia, antagonism from Pseudonocardia towards the cultivar did not reduce sub

  12. Identification of DLD, by immunoproteomic analysis and evaluation as a potential vaccine antigen against three Vibrio species in Epinephelus coioides.

    Science.gov (United States)

    Pang, Huanying; Chen, Liming; Hoare, Rowena; Huang, Yucong; ZaoheWu; Jian, Jichang

    2016-02-24

    Vibrio spp. represent a serious threat to the culture of Epinephelus coioides (Orange-spotted Grouper) in Southeast Asia. In this study we used two-dimensional electrophoresis (2-DE) and Western blotting to identify common immunogenic proteins of Vibrio alginolyticus, Vibrio harveyi and Vibrio parahaemolyticus. Membranes were probed with orange-spotted grouper anti-V. alginolyticus sera and accordingly 60, 58 and 48 immunogenic protein spots were detected. By matching analysis for the three Western blotting membranes, 6 cross immunogenic spots for the three Vibrio species were identified. They were Outer membrane protein W (OmpW), dihydrolipoamide dehydrogenase (DLD), succinate dehydrogenase flavoprotein subunit(SDHA), elongation factor Ts(Ts), peptide ABC transporter periplasmic peptide-binding protein and phosphoenolpyruvate carboxykinase(PEPCK). One of the proteins, DLD, was used to evaluate the cross protective function for E. coioides with a bacterial immunization and challenge method. The relative percent survival rate of E. coioides against V. alginolyticus, V. harveyi and V. parahaemolyticus was 90%, 86% and 80%, respectively. This work may provide potential cross protective vaccine candidate antigens for three Vibrio species, and DLD may be considered as an effective cross-protective immunogen against three Vibrio species. Copyright © 2016. Published by Elsevier Ltd.

  13. The annual cycle of zooplankton-associated Vibrio cholerae and related vibrios in Albufera lake and its coastal surrounding waters (Valencia, Spain).

    Science.gov (United States)

    Arnau, A; Pujalte, M J; Amaro, C; Garay, E

    1988-12-01

    Most probable numbers of zooplankton-associated Vibrio spp. and V. cholerae were determined in Albufera lake, Spain, and in its coastal receiving waters throughout a year. Highest counts of 10(5) bacterial cells/g of plankton were associated to high temperatures and were also related to the kind of water. All isolates were non-01 serovars, and most belonged to Heiberg groups I and II.

  14. Inhibition of protein synthesis does not antagonize induction of UV-induced sister-chromatid exchange in xeroderma pigmentosum cells

    International Nuclear Information System (INIS)

    Sono, Akira; Sakaguchi, Kengo.

    1988-01-01

    Cycloheximide strongly antagonizes the induction of sisterchromatid exchanges by ethyl methanesulfonate or mitomycin C in human skin fibroblast and xeroderma pigmentosum cells (group A). Analogous behavior has been observed in several other species including Chinese hamster and plant cells. This report documents an exception to that pattern: cycloheximide fails to antagonize UV-induced sister chromatid exchange in xeroderma pigmentosum cells, whereas it does in normal human skin fibroblast cells. A genetic defect in these cells is postulated to alter the UV-mediated DNA recombination process. (author)

  15. Impact of solar irradiation on cholera toxin secretion by different strains of Vibrio cholerae

    CSIR Research Space (South Africa)

    Ssemakalu, CC

    2013-09-01

    Full Text Available , Salomon RN, Garrity K, Reveillaud I, Kopin A, Jackson FR, et al. Vibrio cholerae infection of Drosophila melanogaster mimics the human disease cholera. PLoS Pathog. 2005;1(1):e8. http://dx.doi.org/10.1371/ journal.ppat.0010008 2. World Health...

  16. [Post nearly Drowning Vibrio alginolyticus Septicemia Acquired in Reunion (Indian Ocean)].

    Science.gov (United States)

    Gaüzère, B-A; Chanareille, P; Vandroux, D

    2016-08-01

    AbstractWe report the first case of Vibrio alginolyticus septicemia in the Indian Ocean (Reunion Island), in a patient (70-year-old-man) with multiple underlying conditions, following a nearly drowning in the lagoon of Reunion. From now on, V. alginolyticus should be considered as a possible agent of septicemia in the Indian Ocean, particularly following marine activities.

  17. Indole-positive Vibrio vulnificus isolated from disease outbreaks on a Danish eel farm

    DEFF Research Database (Denmark)

    Dalsgaard, Inger; Høi, L.; Siebeling, R.J.

    1999-01-01

    Vibrio vulnificus was isolated in 1996 from 2 disease outbreaks on a Danish eel farm which used brackish water. A characteristic clinical sign was extensive, deep muscle necrosis in the head region. V. vulnificus was isolated from kidney, mucus, spleen, gill and intestine of diseased eels. Thirty...

  18. Cerebral absces med Vibrio cholerae non-01 efter badning i dansk havvand

    DEFF Research Database (Denmark)

    Torp-Pedersen, Trine; Nielsen, Xiaohui Chen; Olsen, Katharina E P

    2012-01-01

    on the ankle. We treated the patient with meropenem and ciprofloxacin for six weeks followed by ciprofloxacin for four weeks, and she recovered with hemiparesis and speech impairment. Marine Vibrio species may produce intracranial infection in predisposed individuals, even in temperate climate zones....

  19. Carbapenemase VCC-1-Producing Vibrio cholerae in Coastal Waters of Germany

    DEFF Research Database (Denmark)

    Hammerl, Jens A.; Jaeckel, Claudia; Bortolaia, Valeria

    2017-01-01

    During antimicrobial drug resistance testing for Vibrio spp. from coastal waters of Germany, we identified 4 nontoxigenic, carbapenem-resistant V. cholerae isolates. We used whole-genome sequencing to identify the carbapenemase gene bla(VCC-1). In addition, a molecular survey showed that more bla...

  20. Effects of triclosan on bacterial community composition and Vibrio populations in natural seawater microcosms

    OpenAIRE

    Lydon, Keri Ann; Glinski, Donna A.; Westrich, Jason R.; Henderson, W. Matthew; Lipp, Erin K.

    2017-01-01

    Pharmaceuticals and personal care products, including antimicrobials, can be found at trace levels in treated wastewater effluent. Impacts of chemical contaminants on coastal aquatic microbial community structure and pathogen abundance are unknown despite the potential for selection through antimicrobial resistance. In particular, 'Vibrio', a marine bacterial genus that includes several human pathogens, displays resistance to the ubiquitous antimicrobial compound triclosan. Here we demonstrat...

  1. Effects of triclosan on bacterial community composition and 'Vibrio' populations in natural seawater microcosms

    Directory of Open Access Journals (Sweden)

    Keri Ann Lydon

    2017-05-01

    Full Text Available Pharmaceuticals and personal care products, including antimicrobials, can be found at trace levels in treated wastewater effluent. Impacts of chemical contaminants on coastal aquatic microbial community structure and pathogen abundance are unknown despite the potential for selection through antimicrobial resistance. In particular, 'Vibrio', a marine bacterial genus that includes several human pathogens, displays resistance to the ubiquitous antimicrobial compound triclosan. Here we demonstrated through use of natural seawater microcosms that triclosan (at a concentration of ~5 ppm can induce a significant 'Vibrio' growth response (68–1,700 fold increases in comparison with no treatment controls for three distinct coastal ecosystems: Looe Key Reef (Florida Keys National Marine Sanctuary, Doctors Arm Canal (Big Pine Key, FL, and Clam Bank Landing (North Inlet Estuary, Georgetown, SC. Additionally, microbial community analysis by 16 S rRNA gene sequencing for Looe Key Reef showed distinct changes in microbial community structure with exposure to 5 ppm triclosan, with increases observed in the relative abundance of 'Vibrio'naceae (17-fold, Pseudoalteromonadaceae (65-fold, Alteromonadaceae (108-fold, Colwelliaceae (430-fold, and Oceanospirillaceae (1,494-fold. While the triclosan doses tested were above concentrations typically observed in coastal surface waters, results identify bacterial families that are potentially resistant to triclosan and/or adapted to use triclosan as a carbon source. The results further suggest the potential for selection of 'Vibrio' in coastal environments, especially sediments, where triclosan may accumulate at high levels.

  2. [Cytotoxic effect of Vibrio cholerae non-O1 on Vero cells].

    Science.gov (United States)

    Figueroa-Arredondo, P; García-Lozano, H; Gutiérrez-Cogco, L; Valdespino-Gómez, J L

    1994-01-01

    At the present time there is still in Mexico a diarrhoeal outbreak due to Vibrio cholerae O1. In INDRE we have isolated from the same outbreak last year (jan-apr), 70 strains of Vibrio cholerae Non-O1. These were isolated from patients with a diarrhoeal illness different from cholera. Patients were of different ages and sex, and from various geographic areas. The isolated strains were confirmed by serological agglutination test with polyclonal antisera, and they neither belong to O1 serogroup or O139. We assayed all the 70 strains in Vero cells, searching for cytotoxic effect, probably attributed to cholera toxin, or any other toxin. The strains were screened by PCR for cholera toxin gene detection, and negative results were obtained. We have found only one CT-producer strain, but it was a rough one so, we are not able to affirm that is not a V. cholerae O1 serotype. Vibrio cholerae Non-O1 strains, tested in Vero cells assay, produced cytotoxic effect within 24 h. It was found that 48/70 strains (66.6%), had cytotoxic activity, showing rounding and then lysis of cells. From our results we concluded that this cytotoxic effect, is not cholera toxin related, instead we propose it could be due to an unknown virulence factor, probably a different toxin in mexican Vibrio cholerae Non-O1 strains.

  3. The protective activity of tea catechins against experimental infection by Vibrio cholerae O1.

    Science.gov (United States)

    Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Hara, Y; Shimamura, T

    1992-01-01

    Tea catechins inhibited the fluid accumulation induced by cholera toxin in sealed adult mice. The catechins also reduced fluid accumulation by Vibrio cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea catechins may possess protective activity against V. cholerae O1.

  4. Three draft genomes of Vibrio coralliilyticus strains isolated from bivalve hatcheries

    Science.gov (United States)

    Reported here are the draft genomes of three Vibrio coralliilyticus isolates RE87, AIC-7, and 080116A. Each strain was isolated in association with diseased oyster larvae in commercial aquaculture systems. These draft genomes will be useful for further studies in understanding the genomic features...

  5. Crystallization of the HigBA2 toxin-antitoxin complex from Vibrio cholerae

    DEFF Research Database (Denmark)

    Hadǽi, San; Garcia-Pino, Abel; Martinez-Rodriguez, Sergio

    2013-01-01

    The genome of Vibrio cholerae encodes two higBA toxin-antitoxin (TA) modules that are activated by amino-acid starvation. Here, the TA complex of the second module, higBA2, as well as the C-terminal domain of the corresponding HigA2 antitoxin, have been purified and crystallized. The HigBA2 compl...

  6. Isolation of Vibrio cholerae serotype O1 from the eastern oyster, Crassostrea virginica.

    Science.gov (United States)

    Hood, M A; Ness, G E; Rodrick, G E

    1981-01-01

    Two strains of Vibrio cholerae serotype O1 Inaba were isolated from eastern oysters, Crassostrea virginica, collected from estuarine waters in Florida during April 1980. The oyster meats and waters from which the oysters were collected had low fecal coliform counts, and the area had no prior evidence of sewage contamination. PMID:7235700

  7. Septic arthritis and subsequent fatal septic shock caused by Vibrio vulnificus infection

    DEFF Research Database (Denmark)

    Emamifar, Amir; Asmussen Andreasen, Rikke; Andersen, Nanna Skaarup

    2015-01-01

    Vibrio vulnificus is a rare but potential fatal bacterium that can cause severe infections. Wound infections, primary sepsis and gastroenteritis are the most common clinical features. Septic arthritis caused by V. vulnificus is an atypical presentation that has been reported in only two case...

  8. Structural organization of the transfer RNA operon I of Vibrio cholerae

    Indian Academy of Sciences (India)

    Nine major transfer RNA (tRNA) gene clusters were analysed in various Vibrio cholerae strains. Of these, only the tRNA operon I was found to differ significantly in V. cholerae classical (sixth pandemic) and El Tor (seventh pandemic) strains. Amongst the sixteen tRNA genes contained in this operon, genes for tRNA Gln3 ...

  9. INS refuerza vigilancia y diagnóstico de enfermedad diarreica producida por Vibrio parahemolyticus

    OpenAIRE

    Huapaya, Blanca

    2005-01-01

    El Instituto Nacional de Salud (INS) está fortaleciendo la vigilancia y el diagnóstico en el Perú del Vibrio parahaemolyticus, bacteria causante de una enfermedad diarreica aguda, que a inicios de este año produjo un brote de aproximadamente 10 mil casos en Chile.

  10. Contamination of community water sources by potentially pathogenic vibrios following sea water inundation.

    Science.gov (United States)

    Kanungo, Reba; Shashikala; Karunasagar, I; Srinivasan, S; Sheela, Devi; Venkatesh, K; Anitha, P

    2007-12-01

    Potentially pathogenic members of the Vibrionaceae family including Vibrio cholerae and Vibrio parahemolyticus were isolated from domestic sources of drinking water in coastal villages following sea water inundation during the tsunami in Southern India. Phenotypic and genotypic studies were done to confirm the identity and detection of toxins. Vibrio-gyr (gyrase B gene) was detected in all sixteen vibrio isolates. Toxin regulating genes i.e.: ctx gene, tdh gene, and trh gene, however were not detected in any of the strains, thereby ruling out presence of toxins which could endanger human life. Other potentially pathogenic bacteria Aeromonas and Plesiomonas were also isolated from hand pumps and wells, in a few localities. There was no immediate danger in the form of an outbreak or sporadic gastroenteritis at the time of the study. Timely chlorination and restoration of potable water supply to the flood affected population by governmental and nongovernmental agencies averted waterborne gastroenteritis. Assessment of quality of water and detection of potential virulent organisms is an important public health activity following natural disasters. This work highlights the importance of screening water sources for potentially pathogenic microorganisms after natural disasters to avert outbreaks of gastroenteritis and other infectious diseases.

  11. Fuse or die: how to survive the loss of Dam in Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Kennedy, Sean P; Soler-Bistue, Alfonso J.

    2014-01-01

    Dam methylates GATC sequences in γ-proteobacteria genomes, regulating several cellular functions including replication. In Vibrio cholerae, which has two chromosomes, Dam is essential for viability, owing to its role in chr2 replication initiation. In this study, we isolated spontaneous mutants o...

  12. Vibrio galatheae sp. nov., a novel member of the Vibrionaceae family isolated from the Solomon Sea

    DEFF Research Database (Denmark)

    Giubergia, Sonia; Machado, Henrique; Mateiu, Ramona Valentina

    2015-01-01

    Based on genetic, chemotaxonomic and phenotypic characteristics, a novel species belonging to the genus Vibrio is described. The facultative anaerobic strain S2757T was isolated from a mussel collected in the Solomon Sea (Solomon Islands). Phylogenetic analyses based on sequences of 16S r...

  13. PREVALENCE AND IDENTIFICATION OF VIBRIO SPP. ISOLATED ON AQUACULTURED GILTHEAD SEA BREAM

    Directory of Open Access Journals (Sweden)

    C. Scarano

    2011-01-01

    Full Text Available The aim of the study was to investigate the prevalence of Vibrio spp isolated from gilthead sea bream (Sparus aurata farmed on sea cages and to identify and characterize the pathogen by molecular techniques. Eighty fish were collected from two hatcheries located on the North-Est Sardinian Mediterranean coast, and microbiological analysis were performed on different body parts such as skin, gills, muscle and intestinal tract. Subsequently 100 pure colonies with typical morphology and phenotypic characteristics were selected and submitted to the molecular identification. The analysis on the prevalence of Vibrio spp showed the effect of the hatchery rearing system (P<0.001, of the date of sampling (P<0.001, and of the body part (P<0.001. All the strains selected were confirmed to be members of the genus Vibrio spp by the molecular method/techinique/identification, whereas the rpoA gene sequence analyses allowed to identify 89 strains belonging to the species Vibrio harveyi, 6 to V. diabolicus, 2 to V. parahaemolyticus and 1 to V. mediterranei.

  14. Occurrence and molecular characterisation of Vibrio parahaemolyticus in crustaceans commercialised in Venice area, Italy.

    Science.gov (United States)

    Caburlotto, Greta; Suffredini, Elisabetta; Toson, Marica; Fasolato, Luca; Antonetti, Paolo; Zambon, Michela; Manfrin, Amedeo

    2016-03-02

    Infections due to the pathogenic human vibrios, Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus, are mainly associated with consumption of raw or partially cooked bivalve molluscs. At present, little is known about the presence of Vibrio species in crustaceans and the risk of vibriosis associated with the consumption of these products. The aim of the present study was to evaluate the prevalence and concentration of the main pathogenic Vibrio spp. in samples of crustaceans (n=143) commonly eaten in Italy, taking into account the effects of different variables such as crustacean species, storage conditions and geographic origin. Subsequently, the potential pathogenicity of V. parahaemolyticus strains isolated from crustaceans (n=88) was investigated, considering the classic virulence factors (tdh and trh genes) and four genes coding for relevant proteins of the type III secretion systems 2 (T3SS2α and T3SS2β). In this study, the presence of V. cholerae and V. vulnificus was never detected, whereas 40 samples (28%) were positive for V. parahaemolyticus with an overall prevalence of 41% in refrigerated products and 8% in frozen products. The highest prevalence and average contamination levels were detected in Crangon crangon (prevalence 58% and median value 3400 MPN/g) and in products from the northern Adriatic Sea (35%), with the samples from the northern Venetian Lagoon reaching a median value of 1375 MPN/g. While genetic analysis confirmed absence of the tdh gene, three of the isolates contained the trh gene and, simultaneously, the T3SS2β genes. Moreover three possibly clonal tdh-negative/trh-negative isolates carried the T3SS2α apparatus. The detection of both T3SS2α and T3SS2β apparatuses in V. parahaemolyticus strains isolated from crustaceans emphasised the importance of considering new genetic markers associated with virulence besides the classical factors. Moreover this study represents the first report dealing with Vibrio spp. in

  15. CB1 receptor antagonism increases hippocampal acetylcholine release: site and mechanism of action.

    Science.gov (United States)

    Degroot, Aldemar; Köfalvi, Attila; Wade, Mark R; Davis, Richard J; Rodrigues, Ricardo J; Rebola, Nelson; Cunha, Rodrigo A; Nomikos, George G

    2006-10-01

    Evidence indicates that blockade of cannabinoid receptors increases acetylcholine (ACh) release in brain cortical regions. Although it is assumed that this type of effect is mediated through CB1 receptor (CB1R) antagonism, several in vitro functional studies recently have suggested non-CB1R involvement. In addition, neither the precise neuroanatomical site nor the exact mechanisms underlying this effect are known. We thoroughly examined these issues using a combination of systemic and local administration of CB1R antagonists, different methods of in vivo microdialysis, CB1R knockout (KO) mice, tissue measurements of ACh, and immunochemistry. First, we showed that systemic injections of the CB1R antagonists N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR-141716A) and N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251) dose-dependently increased hippocampal ACh efflux. Likewise, local hippocampal, but not septal, infusions of SR141716A or AM251 increased hippocampal ACh release. It is noteworthy that the stimulatory effects of systemically administered CB1R antagonists on hippocampal ACh release were completely abolished in CB1R KO mice. CB1R KO mice had similar basal but higher stress-enhanced hippocampal ACh levels compared with wild-type controls. It is interesting that dopamine D1 receptor antagonism counteracted the stimulatory effect of CB1R blockade on hippocampal ACh levels. Finally, immunohistochemical methods revealed that a high proportion of CB1R-positive nerve terminals were found in hippocampus and confirmed the colocalization of CB1 receptors with cholinergic and dopaminergic nerve terminals. In conclusion, hippocampal ACh release may specifically be controlled through CB1Rs located on both cholinergic and dopaminergic neuronal projections, and CB1R antagonism increases hippocampal ACh release, probably through both a direct

  16. Application of chitosan microparticles for reduction of vibrio species in seawater and live oysters (Crassostrea virginica).

    Science.gov (United States)

    Fang, Lei; Wolmarans, Bernhard; Kang, Minyoung; Jeong, Kwang C; Wright, Anita C

    2015-01-01

    Human Vibrio infections associated with consumption of raw shellfish greatly impact the seafood industry. Vibrio cholerae-related disease is occasionally attributed to seafood, but V. vulnificus and V. parahaemolyticus are the primary targets of postharvest processing (PHP) efforts in the United States, as they pose the greatest threat to the industry. Most successful PHP treatments for Vibrio reduction also kill the molluscs and are not suitable for the lucrative half-shell market, while nonlethal practices are generally less effective. Therefore, novel intervention strategies for Vibrio reduction are needed for live oyster products. Chitosan is a bioactive derivative of chitin that is generally recognized as safe as a food additive by the FDA, and chitosan microparticles (CMs) were investigated in the present study as a potential PHP treatment for live oyster applications. Treatment of broth cultures with 0.5% (wt/vol) CMs resulted in growth cessation of V. cholerae, V. vulnificus, and V. parahaemolyticus, reducing culturable levels to nondetectable amounts after 3 h in three independent experiments. Furthermore, a similar treatment in artificial seawater at 4, 25, and 37°C reduced V. vulnificus levels by ca. 7 log CFU/ml after 24 h of exposure, but 48 h of exposure and elevated temperature were required to achieve similar results for V. parahaemolyticus and V. cholerae. Live oysters that either were artificially inoculated or contained natural populations of V. vulnificus and V. parahaemolyticus showed significant and consistent reductions following CM treatment (5%) compared to the amounts in the untreated controls. Thus, the results strongly support the promising potential for the application of CMs as a PHP treatment to reduce Vibrio spp. in intact live oysters. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  17. Impairments of exploration and memory after systemic or prelimbic D1-receptor antagonism in rats

    DEFF Research Database (Denmark)

    Clausen, Bettina; Schachtman, Todd R.; Mark, Louise T.

    2011-01-01

    to examine the effects on memory: cross-maze and object recognition task. Systemic administration reduced spatial exploration in cross-maze as well as in an open field test, and also reduced object exploration. Spatial (hippocampus-dependent) short-term memory was inhibited in the cross-maze and non......-spatial short-term object retention was also impaired. In contrast to these systemic effects, bilateral injections of SCH23390 into the prelimbic cortices altered neither spatial nor object exploration, but did inhibit short-term memory in both cross-maze and object recognition task. Therefore, the inhibiting......D1-receptor antagonism is known to impair rodent memory but also inhibits spontaneous exploration of stimuli to be remembered. Hypo-exploration could contribute to impaired memory by influencing event processing. In order to explore this effect, the D1 receptor antagonist, SCH23390...

  18. GIP-(3-42) does not antagonize insulinotropic effects of GIP at physiological concentrations

    DEFF Research Database (Denmark)

    Deacon, Carolyn F; Plamboeck, Astrid; Rosenkilde, Mette M

    2006-01-01

    Glucose-dependent insulinotropic polypeptide [GIP-(1-42)] is degraded by dipeptidyl peptidase IV (DPP IV), forming GIP-(3-42). In mice, high concentrations of synthetic GIP-(3-42) may function as a GIP receptor antagonist, but it is unclear whether this occurs at physiological concentrations...... GIP, GIP-(3-42) behaved as a weak antagonist (IC(50), 92 and 731 nM for inhibition of cAMP accumulation elicited by 10 pM and 1 nM native GIP, respectively). In the isolated perfused rat pancreas, GIP-(3-42) alone had no effect on insulin output and only reduced the response to GIP (1 nM) when......-42) can weakly antagonize cAMP accumulation and insulin output in vitro, it does not behave as a physiological antagonist in vivo....

  19. USP10 Antagonizes c-Myc Transcriptional Activation through SIRT6 Stabilization to Suppress Tumor Formation

    Directory of Open Access Journals (Sweden)

    Zhenghong Lin

    2013-12-01

    Full Text Available The reduced protein expression of SIRT6 tumor suppressor is involved in tumorigenesis. The molecular mechanisms underlying SIRT6 protein downregulation in human cancers remain unknown. Using a proteomic approach, we have identified the ubiquitin-specific peptidase USP10, another tumor suppressor, as one of the SIRT6-interacting proteins. USP10 suppresses SIRT6 ubiquitination to protect SIRT6 from proteasomal degradation. USP10 antagonizes the transcriptional activity of the c-Myc oncogene through SIRT6, as well as p53, to inhibit cell-cycle progression, cancer cell growth, and tumor formation. To support this conclusion, we detected significant reductions in both USP10 and SIRT6 protein expression in human colon cancers. Our study discovered crosstalk between two tumor-suppressive genes in regulating cell-cycle progression and proliferation and showed that dysregulated USP10 function promotes tumorigenesis through SIRT6 degradation.

  20. Isolation of Fungi from Heterodera glycines and in vitro Bioassays for Their Antagonism to Eggs.

    Science.gov (United States)

    Meyer, S L; Huettel, R N; Sayre, R M

    1990-10-01

    Twenty fungi were assayed in vitro for antagonism to eggs of Heterodera glycines. Eight of the fungi were isolated from cysts or eggs of H. glycines during the current study, one was isolated from Panagrellus redivivus, and eleven were obtained from other researchers or collections. The bioassays were conducted on eggs from nematodes that had been grown monoxenically on excised root tips. Phoma chrysanthemicola, one strain of Verticillium chlamydosporium, and one strain of V. lecanii caused a decrease (P Trichoderma polysporum infected live eggs but enhanced (P Fusarium sp., Neocosmospora vasinfecta, Scytalidium fulvum, Trichoderma harzianum (two strains), V. chlamydosporium (one strain), V. lecanii (three strains), and an unidentified fungus did not measurably affect egg viability, even though hyphae of five of these fungi were seen in live eggs. The bioassay provides a useful step in the selection of a biological control agent for this major nematode pest.

  1. Neuropeptide Y Y5 receptor antagonism attenuates cocaine-induced effects in mice

    DEFF Research Database (Denmark)

    Sørensen, Gunnar; Jensen, Morten; Weikop, Pia

    2012-01-01

    Rationale Several studies suggest a role for neuropeptide Y (NPY) in addiction to drugs of abuse, including cocaine. However, the NPY receptors mediating addiction-related effects remain to be determined. Objectives To explore the potential role of Y5 NPY receptors in cocaine-induced behavioural...... effects. Methods The Y5 antagonist L-152,804 and Y5-knockout (Y5-KO) mice were tested in two models of cocaine addiction-related behaviour: acute self-administration and cocaine-induced hyperactivity. We also studied effects of Y5 receptor antagonism on cocaine-induced c-fos expression and extracellular...... effects, suggesting that Y5 receptors could be a potential therapeutic target in cocaine addiction....

  2. Combining climate and energy policies: synergies or antagonism? Modeling interactions with energy efficiency instruments

    International Nuclear Information System (INIS)

    Lecuyer, Oskar; Bibas, Ruben

    2012-01-01

    In addition to the already present Climate and Energy package, the European Union (EU) plans to include a binding target to reduce energy consumption. We analyze the rationales the EU invokes to justify such an overlapping and develop a minimal common framework to study interactions arising from the combination of instruments reducing emissions, promoting renewable energy (RE) production and reducing energy demand through energy efficiency (EE) investments. We find that although all instruments tend to reduce GHG emissions and although a price on carbon tends also to give the right incentives for RE and EE, the combination of more than one instrument leads to significant antagonisms regarding major objectives of the policy package. The model allows to show in a single framework and to quantify the antagonistic effects of the joint promotion of RE and EE. We also show and quantify the effects of this joint promotion on ETS permit price, on wholesale market price and on energy production levels. (authors)

  3. What Do Structures Tell Us About Chemokine Receptor Function and Antagonism?

    Energy Technology Data Exchange (ETDEWEB)

    Kufareva, Irina; Gustavsson, Martin; Zheng, Yi; Stephens, Bryan S.; Handel, Tracy M. (UCSD)

    2017-05-22

    Chemokines and their cell surface G protein–coupled receptors are critical for cell migration, not only in many fundamental biological processes but also in inflammatory diseases and cancer. Recent X-ray structures of two chemokines complexed with full-length receptors provided unprecedented insight into the atomic details of chemokine recognition and receptor activation, and computational modeling informed by new experiments leverages these insights to gain understanding of many more receptor:chemokine pairs. In parallel, chemokine receptor structures with small molecules reveal the complicated and diverse structural foundations of small molecule antagonism and allostery, highlight the inherent physicochemical challenges of receptor:chemokine interfaces, and suggest novel epitopes that can be exploited to overcome these challenges. The structures and models promote unique understanding of chemokine receptor biology, including the interpretation of two decades of experimental studies, and will undoubtedly assist future drug discovery endeavors.

  4. An ibuprofen-antagonized plasmin inhibitor released by human endothelial cells.

    Science.gov (United States)

    Rockwell, W B; Ehrlich, H P

    1991-02-01

    Serum-free culture medium harvested from endothelial cell monolayer cultures derived from human scars and dermis was examined for inhibition of fibrinolysis using a fibrin plate assay. Human cultured fibroblasts and smooth muscle cells did not produce any detectable inhibitory activity. The inhibitor is spontaneously released from the cultured endothelial cells over time. In the fibrin plate assay of plasmin-induced fibrinolysis, one nonsteroidal antiinflammatory (NSAI) drug, ibuprofen, was demonstrated to antagonize the inhibition of fibrinolysis. The antagonistic activity of ibuprofen appears unrelated to its NSAI drug activity because other NSAI drugs such as indomethacin and tolmetin have minimal antagonistic activity. Heating the cultured endothelial cells to 42 degrees C stimulates greater release of the inhibitor in a shorter period of time. This plasmin inhibitor, which is produced by endothelial cells, may contribute to postburn vascular occlusion, leading to secondary progressive necrosis in burn-traumatized patients.

  5. Silencing the alarms: innate immune antagonism by rotavirus NSP1 and VP3

    Science.gov (United States)

    Morelli, Marco; Ogden, Kristen M.; Patton, John T.

    2016-01-01

    The innate immune response involves a broad array of pathogen sensors that stimulate the production of interferons (IFN) to induce an antiviral state. Rotavirus, a significant cause of childhood gastroenteritis and a member of the Reoviridae family of segmented, double-stranded RNA viruses, encodes at least two direct antagonists of host innate immunity: NSP1 and VP3. NSP1, a putative E3 ubiquitin ligase, mediates the degradation of cellular factors involved in both IFN induction and downstream signaling. VP3, the viral capping enzyme, utilizes a 2H-phosphodiesterase domain to prevent activation of the cellular oligoadenylate synthase (OAS)-RNase L pathway. Computational, molecular, and biochemical studies have provided key insights into the structural and mechanistic basis of innate immune antagonism by NSP1 and VP3 of group A rotaviruses (RVA). Future studies with non-RVA isolates will be essential to understand how other RV species evade host innate immune responses. PMID:25724417

  6. Interleukin-1 antagonism moderates the inflammatory state associated with Type 1 diabetes during clinical trials conducted at disease onset

    DEFF Research Database (Denmark)

    Cabrera, Susanne M; Wang, Xujing; Chen, Yi-Guang

    2016-01-01

    It was hypothesized that IL-1 antagonism would preserve β-cell function in new onset Type 1 diabetes (T1D). However, the Anti-Interleukin-1 in Diabetes Action (AIDA) and TrialNet Canakinumab (TN-14) trials failed to show efficacy of IL-1 receptor antagonist (IL-1Ra) or canakinumab, as measured...

  7. Small molecule antagonism of oxysterol-induced Epstein-Barr virus induced gene 2 (EBI2) activation

    DEFF Research Database (Denmark)

    Benned-Jensen, Tau; Madsen, Christian M; Arfelt, Kristine N

    2013-01-01

    The Epstein-Barr virus induced gene 2 (EBI2) was recently identified as the first oxysterol-activated 7TM receptor. EBI2 is essential for B cell trafficking within lymphoid tissues and thus the humoral immune response in general. Here we characterize the antagonism of the non-peptide molecule GSK...

  8. Comparison of vascular alpha(1)-adrenoceptor antagonism of tamsulosin in oral controlled absorption system (OCAS) and modified release (MR) formulations

    NARCIS (Netherlands)

    Michel, M. C.; Korstanje, C.; Krauwinkel, W.; Shear, M.; Davies, J.; Quartel, A.

    2005-01-01

    Objective: The cardiovascular a-l-adrenoceptor (AR) antagonism of the new oral controlled absorption system (OCAS) 0.4 mg tablet formulation of tamsulosin was compared with that of the modified release (MR) 0.4 mg capsule formulation in healthy male volunteers after a single dose in the fasted

  9. Ghrelin receptor antagonism of hyperlocomotion in cocaine-sensitized mice requires βarrestin-2.

    Science.gov (United States)

    Toth, Krisztian; Slosky, Lauren M; Pack, Thomas F; Urs, Nikhil M; Boone, Peter; Mao, Lan; Abraham, Dennis; Caron, Marc G; Barak, Lawrence S

    2018-01-01

    The "brain-gut" peptide ghrelin, which mediates food-seeking behaviors, is recognized as a very strong endogenous modulator of dopamine (DA) signaling. Ghrelin binds the G protein-coupled receptor GHSR1a, and administration of ghrelin increases the rewarding properties of psychostimulants while ghrelin receptor antagonists decrease them. In addition, the GHSR1a signals through βarrestin-2 to regulate actin/stress fiber rearrangement, suggesting βarrestin-2 participation in the regulation of actin-mediated synaptic plasticity for addictive substances like cocaine. The effects of ghrelin receptor ligands on reward strongly suggest that modulation of ghrelin signaling could provide an effective strategy to ameliorate undesirable behaviors arising from addiction. To investigate this possibility, we tested the effects of ghrelin receptor antagonism in a cocaine behavioral sensitization paradigm using DA neuron-specific βarrestin-2 KO mice. Our results show that these mice sensitize to cocaine as well as wild-type littermates. The βarrestin-2 KO mice, however, no longer respond to the locomotor attenuating effects of the GHSR1a antagonist YIL781. The data presented here suggest that the separate stages of addictive behavior differ in their requirements for βarrestin-2 and show that pharmacological inhibition of βarrestin-2 function through GHSR1a antagonism is not equivalent to the loss of βarrestin-2 function achieved by genetic ablation. These data support targeting GHSR1a signaling in addiction therapy but indicate that using signaling biased compounds that modulate βarrestin-2 activity differentially from G protein activity may be required. © 2017 Wiley Periodicals, Inc.

  10. Comparative analyses of reproductive structures in harvestmen (opiliones reveal multiple transitions from courtship to precopulatory antagonism.

    Directory of Open Access Journals (Sweden)

    Mercedes M Burns

    Full Text Available Explaining the rapid, species-specific diversification of reproductive structures and behaviors is a long-standing goal of evolutionary biology, with recent research tending to attribute reproductive phenotypes to the evolutionary mechanisms of female mate choice or intersexual conflict. Progress in understanding these and other possible mechanisms depends, in part, on reconstructing the direction, frequency and relative timing of phenotypic evolution of male and female structures in species-rich clades. Here we examine evolution of reproductive structures in the leiobunine harvestmen or "daddy long-legs" of eastern North America, a monophyletic group that includes species in which males court females using nuptial gifts and other species that are equipped for apparent precopulatory antagonism (i.e., males with long, hardened penes and females with sclerotized pregenital barriers. We used parsimony- and Bayesian likelihood-based analyses to reconstruct character evolution in categorical reproductive traits and found that losses of ancestral gift-bearing penile sacs are strongly associated with gains of female pregenital barriers. In most cases, both events occur on the same internal branch of the phylogeny. These coevolutionary changes occurred at least four times, resulting in clade-specific designs in the penis and pregenital barrier. The discovery of convergent origins and/or enhancements of apparent precopulatory antagonism among closely related species offers an unusual opportunity to investigate how major changes in reproductive morphology have occurred. We propose new hypotheses that attribute these enhancements to changes in ecology or life history that reduce the duration of breeding seasons, an association that is consistent with female choice, sexual conflict, and/or an alternative evolutionary mechanism.

  11. SB-224289 Antagonizes the Antifungal Mechanism of the Marine Depsipeptide Papuamide A.

    Directory of Open Access Journals (Sweden)

    Chelsi D Cassilly

    Full Text Available In order to expand the repertoire of antifungal compounds a novel, high-throughput phenotypic drug screen targeting fungal phosphatidylserine (PS synthase (Cho1p was developed based on antagonism of the toxin papuamide A (Pap-A. Pap-A is a cyclic depsipeptide that binds to PS in the membrane of wild-type Candida albicans, and permeabilizes its plasma membrane, ultimately causing cell death. Organisms with a homozygous deletion of the CHO1 gene (cho1ΔΔ do not produce PS and are able to survive in the presence of Pap-A. Using this phenotype (i.e. resistance to Pap-A as an indicator of Cho1p inhibition, we screened over 5,600 small molecules for Pap-A resistance and identified SB-224289 as a positive hit. SB-224289, previously reported as a selective human 5-HT1B receptor antagonist, also confers resistance to the similar toxin theopapuamide (TPap-A, but not to other cytotoxic depsipeptides tested. Structurally similar molecules and truncated variants of SB-224289 do not confer resistance to Pap-A, suggesting that the toxin-blocking ability of SB-224289 is very specific. Further biochemical characterization revealed that SB-224289 does not inhibit Cho1p, indicating that Pap-A resistance is conferred by another undetermined mechanism. Although the mode of resistance is unclear, interaction between SB-224289 and Pap-A or TPap-A suggests this screening assay could be adapted for discovering other compounds which could antagonize the effects of other environmentally- or medically-relevant depsipeptide toxins.

  12. Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by ethamsylate.

    Science.gov (United States)

    Hannaert, Patrick; Alvarez-Guerra, Miriam; Hider, Hamida; Chiavaroli, Carlo; Garay, Ricardo P

    2003-04-11

    The hemostatic agent, ethamsylate, inhibits arachidonic acid metabolism by a mechanism independent of cyclooxygenase activity and blocks carrageenan-induced rat paw edema. Here, ethamsylate was investigated for (i) in vivo actions on the free radical-dependent, permeabilizing responses to arachidonic acid and (ii) its antioxidant potential in vitro. Vascular permeability was equated to the extravasation rate of Evans blue from plasma into the rat peritoneal cavity. Antioxidant potential was investigated by classical in vitro tests for superoxide radicals, hydroxyl radicals (OH(.)), and nitric oxide. Intravenous ethamsylate induced a very important and significant reduction of permeability responses to arachidonate, both when given preventively and cumulatively. Thus, (i) ethamsylate significantly reversed arachidonate-induced permeabilization, even at the lowest dose tested (44+/-5% at 10 mg/kg) and (ii) a maximal reversal (about 70%) was reached between 50 and 200 mg/kg ethamsylate. In contrast, ethamsylate (100 mg/kg) was unable to antagonize the vascular permeabilization induced by serotonin (5-HT). In antioxidant assays, ethamsylate showed scavenging properties against hydroxyl radicals generated by the Fenton reaction (H(2)O(2)/Fe(2+)) even at 0.1 microM (-20+/-3%). OH(.) scavenging by ethamsylate reached 42+/-8% at 10 microM and 57+/-7% at 1 mM and was comparable to that of reference compounds (vitamin E, troxerutin, and mannitol). Conversely, ethamsylate was a poor scavenger of superoxide and nitric oxide radicals. In conclusion, intravenous ethamsylate potently antagonized the peritoneal vascular permeabilization induced by arachidonate, an action likely due to its antioxidant properties, particularly against hydroxyl radical. Such a mechanism can explain previous observations that ethamsylate inhibits carrageenan-induced rat paw edema. Whether it also participates in the hemostatic action of ethamsylate deserves further investigation.

  13. Environmental variation shifts the relationship between trees and scatterhoarders along the continuum from mutualism to antagonism.

    Science.gov (United States)

    Sawaya, Gina M; Goldberg, Adam S; Steele, Michael A; Dalgleish, Harmony J

    2018-05-01

    The conditional mutualism between scatterhoarders and trees varies on a continuum from mutualism to antagonism and can change across time and space, and among species. We examined 4 tree species (red oak [Quercus rubra], white oak [Quercus alba], American chestnut [Castanea dentata] and hybrid chestnut [C. dentata × Castanea mollissima) across 5 sites and 3 years to quantify the variability in this conditional mutualism. We used a published model to compare the rates of seed emergence with and without burial to the probability that seeds will be cached and left uneaten by scatterhoarders to quantify variation in the conditional mutualism that can be explained by environmental variation among sites, years, species, and seed provenance within species. All species tested had increased emergence when buried. However, comparing benefits of burial to the probability of caching by scatterhoarders indicated a mutualism in red oak, while white oak was nearly always antagonistic. Chestnut was variable around the boundary between mutualism and antagonism, indicating a high degree of context dependence in the relationship with scatterhoarders. We found that different seed provenances did not vary in their potential for mutualism. Temperature did not explain microsite differences in seed emergence in any of the species tested. In hybrid chestnut only, emergence on the surface declined with soil moisture in the fall. By quantifying the variation in the conditional mutualism that was not caused by changes in scatterhoarder behavior, we show that environmental conditions and seed traits are an important and underappreciated component of the variation in the relationship between trees and scatterhoarders. © 2018 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  14. The analgesic effects of intrathecal xylazine and detomidine in sheep and their antagonism with systemic atipamezole.

    Science.gov (United States)

    Christina Haerdi-Landerer, M; Schlegel, Urs; Neiger-Aeschbacher, Gina

    2005-09-01

    To evaluate the analgesic and adverse side effects of intrathecal (IT) xylazine (XYL) and detomidine (DET) and the subsequent effects of two doses of intravenous (IV) atipamezole (ATI). Prospective, randomized, cross-over. Five adult healthy female sheep with mean body mass of 55 +/- 2.3 kg. Material and methods Each sheep underwent four treatments: 1) 50 microg kg(-1) XYL IT and 5 microg kg(-1) ATI IV, 2) 50 microg kg(-1) XYL IT and 2.5 microg kg(-1) ATI IV, 3) 10 microg kg(-1) DET IT and 5 microg kg(-1) ATI IV, 4) 10 microg kg(-1) DET IT and 2.5 microg kg(-1) ATI IV. Pain threshold (TH) was tested by applying pulsed and stepwise incremental direct current to the skin overlying the pastern. The current at the point of foot lift was recorded as the TH. Heart rate (HR), mean arterial pressure, arterial oxygen (PO(2)) and carbon dioxide (PCO(2)) tensions were monitored. Outcomes were derived as differences between baseline assessment and measurements after treatment. Two-way anova was used to analyse drug effects, treatment differences between groups were examined with an F-test or Wilcoxon's rank sum test in case of non-parametric data distribution. p was set at 0.05. Both drugs increased the pain TH, caused small increases in PCO(2), and small decreases in HR, the latter was only significant for XYL recipients. Xylazine produced a significantly higher TH, more rapidly and for longer than DET. Atipamezole only significantly affected PaCO(2) in the XYL group 2. The pain TH was not affected in either group after IV ATI. At the doses used, IT XYL, and to a lesser extent DET, induced pastern analgesia. Atipamezole 5 microg kg(-1) IV antagonized some side effects without affecting analgesia. Intrathecal XYL may be useful as an analgesic in sheep. Its safety is increased because IV ATI antagonizes side effects, but not analgesia.

  15. Antagonism pattern detection between microRNA and target expression in Ewing's sarcoma.

    Directory of Open Access Journals (Sweden)

    Loredana Martignetti

    Full Text Available MicroRNAs (miRNAs have emerged as fundamental regulators that silence gene expression at the post-transcriptional and translational levels. The identification of their targets is a major challenge to elucidate the regulated biological processes. The overall effect of miRNA is reflected on target mRNA expression, suggesting the design of new investigative methods based on high-throughput experimental data such as miRNA and transcriptome profiles. We propose a novel statistical measure of non-linear dependence between miRNA and mRNA expression, in order to infer miRNA-target interactions. This approach, which we name antagonism pattern detection, is based on the statistical recognition of a triangular-shaped pattern in miRNA-target expression profiles. This pattern is observed in miRNA-target expression measurements since their simultaneously elevated expression is statistically under-represented in the case of miRNA silencing effect. The proposed method enables miRNA target prediction to strongly rely on cellular context and physiological conditions reflected by expression data. The procedure has been assessed on synthetic datasets and tested on a set of real positive controls. Then it has been applied to analyze expression data from Ewing's sarcoma patients. The antagonism relationship is evaluated as a good indicator of real miRNA-target biological interaction. The predicted targets are consistently enriched for miRNA binding site motifs in their 3'UTR. Moreover, we reveal sets of predicted targets for each miRNA sharing important biological function. The procedure allows us to infer crucial miRNA regulators and their potential targets in Ewing's sarcoma disease. It can be considered as a valid statistical approach to discover new insights in the miRNA regulatory mechanisms.

  16. Ecology, Inhibitory Activity, and Morphogenesis of a Marine Antagonistic Bacterium Belonging to the Roseobacter Clade

    DEFF Research Database (Denmark)

    Bruhn, Jesper Bartholin; Nielsen, Kristian Fog; Hjelm, Mette

    2005-01-01

    Roseobacter strain 27-4 has been isolated from a turbot larval rearing unit and is capable of reducing mortality in turbot egg yolk sac larvae. Here, we demonstrate that the supernatant of Roseobacter 27-4 is lethal to the larval pathogens Vibrio anguillarum and Vibrio splendidus in a buffer syst...

  17. Evaluation of the natural prevalence of Vibrio spp. in Uruguayan mussels (Mytilus sp.) and their control using irradiation

    International Nuclear Information System (INIS)

    Lopez, C.

    2001-01-01

    The presence of potentially pathogenic bacteria belonging to the Vibrionacea, especially Vibrio cholerae, and of Salmonella spp., was examined in fresh Uruguayan mussels (Mytilus sp.) during two annual seasons. The radiation decimal reduction dose (D 10 ) of various toxigenic strains of Vibrio cholerae was determined to vary in vitro between 0.11 and 0.19 kGy. These results and those from the examination of natural Vibrio spp. contamination in mussels were used to conclude that 1.0 kGy would be enough to render Uruguayan mussels Vibrio-safe. Mussels irradiated in the shell at the optical dose survived long enough to allow the eventual introduction of irradiation as an effective intervention measure without affecting local marketing practices, and making it possible to market the fresh mussels live, as required by Uruguayan legislation. (author)

  18. Differential effects of early-life NMDA receptor antagonism on aspartame-impaired insulin tolerance and behavior.

    Science.gov (United States)

    Collison, Kate S; Inglis, Angela; Shibin, Sherin; Andres, Bernard; Ubungen, Rosario; Thiam, Jennifer; Mata, Princess; Al-Mohanna, Futwan A

    2016-12-01

    We have previously showed that lifetime exposure to aspartame, commencing in utero via the mother's diet, may impair insulin tolerance and cause behavioral deficits in adulthood via mechanisms which are incompletely understood. The role of the CNS in regulating glucose homeostasis has been highlighted by recent delineation of the gut-brain axis, in which N-methyl-d-aspartic acid receptors (NMDARs) are important in maintaining glucose homeostasis, in addition to regulating certain aspects of behavior. Since the gut-brain axis can be modulated by fetal programming, we hypothesized that early-life NMDAR antagonism may affect aspartame-induced glucose deregulation in adulthood, and may alter the aspartame behavioral phenotype. Accordingly, C57Bl/6J mice were chronically exposed to aspartame commencing in utero, in the presence and absence of maternal administration of the competitive NMDAR antagonist CGP 39551, from conception until weaning. Drug/diet interactions in adulthood glucocentric and behavioral parameters were assessed. Aspartame exposure elevated blood glucose and impaired insulin-induced glucose disposal during an insulin tolerance test, which could be normalized by NMDAR antagonism. The same effects were not observed in control diet mice, suggesting an early-life drug/diet interaction. Behavioral analysis of adult offspring indicated that NMDAR antagonism of control diet mice caused hyperlocomotion and impaired spatial navigation. Conversely hypolocomotion, reduced exploratory activity and increased anxiety-related behavior were apparent in aspartame diet mice with early-life NMDAR antagonism. significant drug/diet interactions in glucocentric and behavioral parameters were identified in aspartame-exposed mice with early-life NMDAR antagonism. This suggests a possible involvement of early NMDAR interactions in aspartame-impaired glucose homeostasis and behavioral deficits. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Exoproteome and Secretome Derived Broad Spectrum Novel Drug and Vaccine Candidates in Vibrio cholerae Targeted by Piper betel Derived Compounds

    Science.gov (United States)

    Barh, Debmalya; Barve, Neha; Gupta, Krishnakant; Chandra, Sudha; Jain, Neha; Tiwari, Sandeep; Leon-Sicairos, Nidia; Canizalez-Roman, Adrian; Rodrigues dos Santos, Anderson; Hassan, Syed Shah; Almeida, Síntia; Thiago Jucá Ramos, Rommel; Augusto Carvalho de Abreu, Vinicius; Ribeiro Carneiro, Adriana; de Castro Soares, Siomar; Luiz de Paula Castro, Thiago; Miyoshi, Anderson; Silva, Artur; Kumar, Anil; Narayan Misra, Amarendra; Blum, Kenneth; Braverman, Eric R.; Azevedo, Vasco

    2013-01-01

    Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC) for most of the pathogenic Vibrio strains. Two targets (uppP and yajC) are novel to Vibrio, and two targets (uppP and ompU) can be used to develop both drugs and vaccines (dual targets) against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species. PMID:23382822

  20. Isolation of vibrio spp. In oysters (crassostrea rhizophorea) caught in the ‘de la virgen’ swamp

    OpenAIRE

    López Gutiérrez, Lercy; Autor; Manjarrez Pava, Ganiveth; Autor; Herrera Rodríguez, Lilibeth; Autor; Montes Payares, Ana Elena; Autor; Olascuaga Ruíz, Yuranis Paola; Autor; Ortega Quiroz, Rolando José; Autor

    2015-01-01

    Objective:  To establish contamination by Vibrio in oysters (Crassostrea rhizophorae) caught in De La Virgen Swamp, in order to alert entities in charge or protecting consumer health in Cartagena city. Methods: Between February and April 2006, 67 oysters from 5 strategic sites along De La Virgen Swamp, were analyzed. Insulation and identification of Vibrio was performed through a culture and biochemical tests.Results.  Predominant species were V. alginolyticus (23%),V fluvialis  (20%),V. para...

  1. Abundance and Multilocus Sequence Analysis of Vibrio Bacteria Associated with Diseased Elkhorn Coral (Acropora palmata) of the Florida Keys.

    Science.gov (United States)

    Kemp, Keri M; Westrich, Jason R; Alabady, Magdy S; Edwards, Martinique L; Lipp, Erin K

    2018-01-15

    The critically endangered elkhorn coral ( Acropora palmata ) is affected by white pox disease (WPX) throughout the Florida Reef Tract and wider Caribbean. The bacterium Serratia marcescens was previously identified as one etiologic agent of WPX but is no longer consistently detected in contemporary outbreaks. It is now believed that multiple etiologic agents cause WPX; however, to date, no other potential pathogens have been thoroughly investigated. This study examined the association of Vibrio bacteria with WPX occurrence from August 2012 to 2014 at Looe Key Reef in the Florida Keys, USA. The concentration of cultivable Vibrio was consistently greater in WPX samples than in healthy samples. The abundance of Vibrio bacteria relative to total bacteria was four times higher in samples from WPX lesions than in adjacent apparently healthy regions of diseased corals based on quantitative PCR (qPCR). Multilocus sequence analysis (MLSA) was used to assess the diversity of 69 Vibrio isolates collected from diseased and apparently healthy A. palmata colonies and the surrounding seawater. Vibrio species with known pathogenicity to corals were detected in both apparently healthy and diseased samples. While the causative agent(s) of contemporary WPX outbreaks remains elusive, our results suggest that Vibrio spp. may be part of a nonspecific heterotrophic bacterial bloom rather than acting as primary pathogens. This study highlights the need for highly resolved temporal sampling in situ to further elucidate the role of Vibrio during WPX onset and progression. IMPORTANCE Coral diseases are increasing worldwide and are now considered a major contributor to coral reef decline. In particular, the Caribbean has been noted as a coral disease hot spot, owing to the dramatic loss of framework-building acroporid corals due to tissue loss diseases. The pathogenesis of contemporary white pox disease (WPX) outbreaks in Acropora palmata remains poorly understood. This study investigates the

  2. Comparative genome analysis of non-toxigenic non-O1 versus toxigenic O1 Vibrio cholerae

    OpenAIRE

    Mukherjee, Munmun; Kakarla, Prathusha; Kumar, Sanath; Gonzalez, Esmeralda; Floyd, Jared T.; Inupakutika, Madhuri; Devireddy, Amith Reddy; Tirrell, Selena R.; Bruns, Merissa; He, Guixin; Lindquist, Ingrid E.; Sundararajan, Anitha; Schilkey, Faye D.; Mudge, Joann; Varela, Manuel F.

    2014-01-01

    Pathogenic strains of Vibrio cholerae are responsible for endemic and pandemic outbreaks of the disease cholera. The complete toxigenic mechanisms underlying virulence in Vibrio strains are poorly understood. The hypothesis of this work was that virulent versus non-virulent strains of V. cholerae harbor distinctive genomic elements that encode virulence. The purpose of this study was to elucidate genomic differences between the O1 serotypes and non-O1 V. cholerae PS15, a non-toxigenic strain,...

  3. Exoproteome and secretome derived broad spectrum novel drug and vaccine candidates in Vibrio cholerae targeted by Piper betel derived compounds.

    Directory of Open Access Journals (Sweden)

    Debmalya Barh

    Full Text Available Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC for most of the pathogenic Vibrio strains. Two targets (uppP and yajC are novel to Vibrio, and two targets (uppP and ompU can be used to develop both drugs and vaccines (dual targets against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species.

  4. Diversity and dynamics of the Vibrio community in well water used for drinking in Guinea-Bissau (West Africa).

    Science.gov (United States)

    Machado, A; Bordalo, A A

    2014-09-01

    Bacteria of the genus Vibrio are ubiquitous in aquatic environments and can be found either in culturable or in a viable but nonculturable (VBNC) state. The genus comprises many pathogenic species accountable for water and food-borne diseases that prove to be fatal, especially in developing countries, as in Guinea-Bissau (West Africa), where cholera is endemic. In order to ascertain the abundance and structure of Vibrio spp. community in well waters that serve as the sole source of water for the population, quantitative polymerase chain reaction (qPCR), PCR-denaturant gradient gel electrophoresis (DGGE), and cloning approaches were used. Results suggest that Vibrio spp. were present throughout the year in acidic, freshwater wells with a seasonal community composition shift. Vibrio spp. abundance was in accordance with the abundance found in coastal environments. Sequences closely related to pathogenic Vibrio species were retrieved from well water revealing exposure of the population to such pathogens. pH, ammonium, and turbidity, regulated by the rain pattern, seem to be the variables that contributed mostly to the shaping and selection of the Vibrio spp. community. These results reinforce the evidence for water monitoring with culture-independent methods and the clear need to create/recover water infrastructures and a proper water resources management in West African countries with similar environmental conditions.

  5. Exogenous Polyunsaturated Fatty Acids Impact Membrane Remodeling and Affect Virulence Phenotypes among Pathogenic Vibrio Species.

    Science.gov (United States)

    Moravec, Anna R; Siv, Andrew W; Hobby, Chelsea R; Lindsay, Emily N; Norbash, Layla V; Shults, Daniel J; Symes, Steven J K; Giles, David K

    2017-11-15

    The pathogenic Vibrio species ( V. cholerae , V. parahaemolyticus , and V. vulnificus ) represent a constant threat to human health, causing foodborne and skin wound infections as a result of ingestion of or exposure to contaminated water and seafood. Recent studies have highlighted Vibrio 's ability to acquire fatty acids from environmental sources and assimilate them into cell membranes. The possession and conservation of such machinery provokes consideration of fatty acids as important factors in the pathogenic lifestyle of Vibrio species. The findings here link exogenous fatty acid exposure to changes in bacterial membrane phospholipid structure, permeability, phenotypes associated with virulence, and consequent stress responses that may impact survival and persistence of pathogenic Vibrio species. Polyunsaturated fatty acids (PUFAs) (ranging in carbon length and unsaturation) supplied in growth medium were assimilated into bacterial phospholipids, as determined by thin-layer chromatography and liquid chromatography-mass spectrometry. The incorporation of fatty acids variably affected membrane permeability, as judged by uptake of the hydrophobic compound crystal violet. For each species, certain fatty acids were identified as affecting resistance to antimicrobial peptide treatment. Significant fluctuations were observed with regard to both motility and biofilm formation following growth in the presence of individual PUFAs. Our results illustrate the important and complex roles of exogenous fatty acids in the membrane physiology and virulence of a bacterial genus that inhabits aquatic and host environments containing an abundance of diverse fatty acids. IMPORTANCE Bacterial responses to fatty acids include, but are not limited to, degradation for metabolic gain, modification of membrane lipids, alteration of protein function, and regulation of gene expression. Vibrio species exhibit significant diversity with regard to the machinery known to participate in the

  6. pirABvp-Bearing Vibrio parahaemolyticus and Vibrio campbellii Pathogens Isolated from the Same AHPND-Affected Pond Possess Highly Similar Pathogenic Plasmids

    Directory of Open Access Journals (Sweden)

    Xuan Dong

    2017-10-01

    Full Text Available Acute hepatopancreatic necrosis disease (AHPND is a severe shrimp disease originally shown to be caused by virulent strains of Vibrio parahaemolyticus (VPAHPND. Rare cases of AHPND caused by Vibrio species other than V. parahaemolyticus were reported. We compared an AHPND-causing V. campbellii (VCAHPND and a VPAHPND isolate from the same AHPND-affected pond. Both strains are positive for the virulence genes pirABvp. Immersion challenge test with Litopenaeus vannamei indicated the two strains possessed similar pathogenicity. Complete genome comparison showed that the pirABvp-bearing plasmids in the two strains were highly homologous, and they both shared high homologies with plasmid pVA1, the reported pirABvp-bearing plasmid. Conjugation and DNA-uptake genes were found on the pVA1-type plasmids and the host chromosomes, respectively, which may facilitate the dissemination of pirABvp. Novel variations likely driven by ISVal1 in the genetic contexts of the pirABvp genes were found in the two strains. Moreover, the VCAHPND isolate additionally contains multiple antibiotic resistance genes, which may bring difficulties to control its future outbreak. The dissemination of the pirABvp in non-parahaemolyticus Vibrio also rises the concern of missing detection in industrial settings since the isolation method currently used mainly targeting V. parahaemolyticus. This study provides timely information for better understanding of the causes of AHPND and molecular epidemiology of pirABvp and also appeals for precautions to encounter the dissemination of the hazardous genes.

  7. Estudo da radiosensibilidade ao 60CO do Vibrio cholerae O1 incorporado em ostras Radiosensibility of Vibrio cholerae o1 incorporated in oysters, to 60CO

    Directory of Open Access Journals (Sweden)

    Ivany R de Moraes

    2000-02-01

    Full Text Available OBJETIVO: Avaliar a eficiência da radiação ionizante por 60CO na eliminação de Vibrio cholerae O1, El Tor Ogawa, não-toxigênico, incorporados laboratorialmente em ostras vivas da espécie Crassostrea brasiliana. MÉTODO: Foram selecionadas amostras de ostras provenientes de Canan��ia (litoral sul de São Paulo, Brasil, as quais foram contaminadas com Vibrio cholerae e irradiadas com doses de 0,5 kGy e 1,0 kGy. RESULTADOS: Foram observadas diminuições significativas do número inicial do microrganismo indicado: de 3,4.10(7 para 10³ e 10², respectivamente. Os valores de D10 correspondentes foram de 0,173 a 0,235. CONCLUSÃO: Adotando-se o fator 6 como nível de segurança, conclui-se que a dose de irradiação de 1,41 kGy é necessária para eliminar números elevados de células viáveis de V. cholerae em ostras. Os experimentos foram realizados com os controles respectivos.OBJECTIVE: Evaluate the effect of ionizing irradiation by 60Co on Vibrio cholerae O1, El-Tor, Ogawa, non-toxigenic, incorporated in live oysters Crassostrea brasiliana. METHODS: Samples of oysters were selected from Cananéia town in the South coast of S. Paulo state, Brazil, contaminated with Vibrio cholerae and irradiated with 60Co at 0.5 and 1.0 kGy dosages. RESULTS: Showed significant reductions of the initial number of V. cholerae , ranging from 3.4 x10(7 to 10³ and 10², respectively. The D10 values related with the respective doses of irradiation were 0.173 and 0.235. CONCLUSION: Considering a 6 value as safety factor, it is concluded that 1.41 kGy irradiation dosage is necessary to eliminate a high number of V. cholerae viable cells in oysters. Controls were used in the experiment.

  8. Reducing the 2, 4 D+MCPA Antagonism from Hard Spray Waters by Ammonium Sulfate

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Torabi

    2017-03-01

    Full Text Available Introduction: Water is the main carrier of herbicides (HC that its quality plays an important role in herbicide performance hard water has a high concentration of Ca++ and Mg++ and reviews have shown that calcium, manganese and zinc are the main factors reducing the effectiveness of weak acid herbicides. Weak acid herbicides such as glyphosate, paraquat, clethodim and 2, 4 D are compounds that release the H+ ions once dissolved in water, but just slightly. Therefore, herbicides that are weak acids partially dissociate. Herbicides not dissociated (the compound remains whole are more readily absorbed by plant foliage than those that dissociate. Dissociated herbicide molecules have a negative charge. After being dissociated, herbicides might remain as negatively charged molecules, or they might bind with other positively charged cations. Binding to some cations improves herbicide uptake and absorption, binding to others such as Ca++ and Mg++ antagonizes herbicide activity by decreasing absorption or activity in the cell. To correct such carriers, the use of adjuvants, such as ammonium sulphate (AMS, is recommended, which can reduce the use of herbicides and cause economic savings. The aim of this study was to investigate the simple effects and interactions between different amounts of AMS and carrier hardness (CH levels on 2, 4 D + MCPA herbicide efficacy in controlling white clover (Trifolium repens L. in turf grass. Materials and Methods: The experiment was laid out in a RCBD with three replications for each treatment during spring-summer 2013 in 10 years old mixed cold season turf grass (Festuca rubra + Poa pratensis + Poa pratensis dominated by white clover in Mashhad (Iran. The treatments were the factorial combination of four carrier hardness (CH rates (Deionized, 45, 90 and 180 ppm of Ca++ +Mg++ and three Ammonium Sulfate (AMS rates (0, 2, 3 and 4 Kg per100 L of carrier water were studied. The turf was sprayed with 2, 4 D + MCPA (67.5% SL at

  9. Tropical Atlantic marine macroalgae with bioactivity against virulent and antibiotic resistant Vibrio

    Directory of Open Access Journals (Sweden)

    Giselle Cristina Silva

    2013-03-01

    Full Text Available The antibacterial activity of ethanol, methanol, hexane and acetone-based extracts of the macroalgae Padina gymnospora (PG, Hypnea musciformes (HM, Ulva fasciata (UF and Caulerpa prolifera (CP was investigated. The disk diffusion method was used to evaluate the algae antimicrobial effect against standard strains of Vibrio parahaemolyticus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella enterica and five virulent antibiotic-resistant strains of V. brasiliensis, V. xuii and V. navarrensis (isolated from the hemolymph of Litopenaeus vannamei. Ethanol extracts of PG and HM inhibited all Vibrio strains. E. coli and P. aeruginosa were only susceptible to ethanol extracts of PG. Among the methanol extracts, only UF was bioactive, inhibiting V. navarrensis. The observed inhibitory effect of ethanol extracts of PG, HM and UF against virulent antibiotic-resistant bacteria suggests these macroalgal species constitute a potential source of bioactive compounds.

  10. A Real-Time PCR with Melting Curve Analysis for Molecular Typing of Vibrio parahaemolyticus.

    Science.gov (United States)

    He, Peiyan; Wang, Henghui; Luo, Jianyong; Yan, Yong; Chen, Zhongwen

    2018-05-23

    Foodborne disease caused by Vibrio parahaemolyticus is a serious public health problem in many countries. Molecular typing has a great scientific significance and application value for epidemiological research of V. parahaemolyticus. In this study, a real-time PCR with melting curve analysis was established for molecular typing of V. parahaemolyticus. Eighteen large variably presented gene clusters (LVPCs) of V. parahaemolyticus which have different distributions in the genome of different strains were selected as targets. Primer pairs of 18 LVPCs were distributed into three tubes. To validate this newly developed assay, we tested 53 Vibrio parahaemolyticus strains, which were classified in 13 different types. Furthermore, cluster analysis using NTSYS PC 2.02 software could divide 53 V. parahaemolyticus strains into six clusters at a relative similarity coefficient of 0.85. This method is fast, simple, and conveniently for molecular typing of V. parahaemolyticus.

  11. Repair of ultraviolet-light-induced DNA damage in Vibrio cholerae

    International Nuclear Information System (INIS)

    Das, G.; Sil, K.; Das, J.

    1981-01-01

    Repair of ultraviolet-light-induced DNA damage in a highly pathogenic Gram-negative bacterium, Vibrio cholerae, has been examined. All three strains of V. cholerae belonging to two serotypes, Inaba and Ogawa, are very sensitive to ultraviolet irradiation, having inactivation cross-sections ranging from 0.18 to 0.24 m 2 /J. Although these cells are proficient in repairing the DNA damage by a photoreactivation mechanism, they do not possess efficient dark repair systems. The mild toxinogenic strain 154 of classical Vibrios presumably lacks any excision repair mechanism and studies of irradiated cell DNA indicate that the ultraviolet-induced pyrimidine dimers may not be excised. Ultraviolet-irradiated cells after saturation of dark repair can be further photoreactivated. (Auth.)

  12. Pathogenic Vibrio parahaemolyticus isolated from biofouling on commercial vessels and harbor structures.

    Science.gov (United States)

    Revilla-Castellanos, Valeria J; Guerrero, Abraham; Gomez-Gil, Bruno; Navarro-Barrón, Erick; Lizárraga-Partida, Marcial L

    2015-01-01

    Ballast water is a significant vector of microbial dissemination; however, biofouling on commercial vessel hulls has been poorly studied with regard to pathogenic bacteria transport. Biofouling on three commercial vessels and seven port structures in Ensenada, Baja California, Mexico, was examined by qPCR to identify and quantify Vibrio parahaemolyticus, a worldwide recognized food-borne human pathogen. Pathogenic variants (trh+, tdh+) of V. parahaemolyticus were detected in biofouling homogenates samples from several docks in Ensenada and on the hulls of ships with Japanese and South Korean homeports, but not in reference sampling stations. A total of 26 tdh+ V. parahaemolyticus colonies and 1 ORF8+/O3:K6 strain were also isolated from enriched biofouling homogenate samples confirming the qPCR analysis. Our results suggest that biofouling is an important reservoir of pathogenic vibrios. Thus, ship biofouling might be an overlooked vector with regard to the dissemination of pathogens, primarily pathogenic V. parahaemolyticus.

  13. The application of bioflocs technology to protect brine shrimp (Artemia franciscana) from pathogenic Vibrio harveyi.

    Science.gov (United States)

    Crab, R; Lambert, A; Defoirdt, T; Bossier, P; Verstraete, W

    2010-11-01

    To study the potential biocontrol activity of bioflocs technology. Glycerol-grown bioflocs were investigated for their antimicrobial and antipathogenic properties against the opportunistic pathogen Vibrio harveyi. The bioflocs did not produce growth-inhibitory substances. However, bioflocs and biofloc supernatants decreased quorum sensing-regulated bioluminescence of V. harveyi. This suggested that the bioflocs had biocontrol activity against this pathogen because quorum sensing regulates virulence of vibrios towards different hosts. Interestingly, the addition of live bioflocs significantly increased the survival of gnotobiotic brine shrimp (Artemia franciscana) larvae challenged to V. harveyi. Bioflocs grown on glycerol as carbon source inhibit quorum sensing-regulated bioluminescence in V. harveyi and protect brine shrimp larvae from vibriosis. The results presented in this study indicate that in addition to water quality control and in situ feed production, bioflocs technology could help in controlling bacterial infections within the aquaculture pond. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  14. Pathogenic bacteriumVibrio harveyi: an endosymbiont in the marine parasitic ciliate protozoan Cryptocaryon irritans

    Institute of Scientific and Technical Information of China (English)

    QIAO Ying; WANG Jun; MAO Yong; LIU Min; CHEN Ruanni; SU Yongquan; KE Qiaozhen; HAN Kunhuang; ZHENG Weiqiang

    2017-01-01

    Vibrio harveyi, known as a pathogenic bacterium caused severe secondary bacterial infections of the large yellow croaker Larimichthys crocea, was identified as an endosymbiont in the marine parasitic ciliate protozoan Cryptocaryon irritans. Meta 16S sequencing method was used to identify the bacterial flora in C. irritans, and V. harveyi was isolated via culture-dependent method.Vibrio harveyi was observed in cytoplasm of C. irritans at the stage of tomont both by transmission electron microscopy and by Fluorescencein situ hybridization; no signal, however, was detected in nucleus area. The relationship betweenV. harveyi and C. irritans and the role of endosymbioticV. harveyi inC. irritans merit further investigation.

  15. The parental antagonism theory of language evolution: preliminary evidence for the proposal.

    Science.gov (United States)

    Brown, William M

    2011-04-01

    not maternally silenced Alu elements are positively correlated with language diversity. Furthermore, there is a much higher than expected frequency of Alu elements inserted into the protein-coding machinery of imprinted and X-chromosomal language loci compared with nonimprinted language loci. Taken together these findings provide some support for parental antagonism theory. Unlike previous theories for language evolution, parental antagonism theory generates testable predictions at the proximate (e.g., neurocognitive areas important for social transmission and language capacities), ontogenetic (e.g., the function of language at different points of development), ultimate (e.g., inclusive fitness), and phylogenetic levels (e.g., the spread of maternally derived brain components in mammals, particularly in the hominin lineage), thus making human capacities for culture more tractable than previously thought.

  16. Feline immunodeficiency virus envelope glycoproteins antagonize tetherin through a distinctive mechanism that requires virion incorporation.

    Science.gov (United States)

    Morrison, James H; Guevara, Rebekah B; Marcano, Adriana C; Saenz, Dyana T; Fadel, Hind J; Rogstad, Daniel K; Poeschla, Eric M

    2014-03-01

    BST2/tetherin inhibits the release of enveloped viruses from cells. Primate lentiviruses have evolved specific antagonists (Vpu, Nef, and Env). Here we characterized tetherin proteins of species representing both branches of the order Carnivora. Comparison of tiger and cat (Feliformia) to dog and ferret (Caniformia) genes demonstrated that the tiger and cat share a start codon mutation that truncated most of the tetherin cytoplasmic tail early in the Feliformia lineage (19 of 27 amino acids, including the dual tyrosine motif). Alpha interferon (IFN-α) induced tetherin and blocked feline immunodeficiency virus (FIV) replication in lymphoid and nonlymphoid feline cells. Budding of bald FIV and HIV particles was blocked by carnivore tetherins. However, infectious FIV particles were resistant, and spreading FIV replication was uninhibited. Antagonism mapped to the envelope glycoprotein (Env), which rescued FIV from carnivore tetherin restriction when expressed in trans but, in contrast to known antagonists, did not rescue noncognate particles. Also unlike the primate lentiviral antagonists, but similar to the Ebola virus glycoprotein, FIV Env did not reduce intracellular or cell surface tetherin levels. Furthermore, FIV-enveloped FIV particles actually required tetherin for optimal release from cells. The results show that FIV Envs mediate a distinctive tetherin evasion. Well adapted to a phylogenetically ancient tetherin tail truncation in the Felidae, it requires functional virion incorporation of Env, and it shields the budding particle without downregulating plasma membrane tetherin. Moreover, FIV has evolved dependence on this protein: particles containing FIV Env need tetherin for optimal release from the cell, while Env(-) particles do not. HIV-1 antagonizes the restriction factor tetherin with the accessory protein Vpu, while HIV-2 and the filovirus Ebola use their envelope (Env) glycoproteins for this purpose. It turns out that the FIV tetherin antagonist is

  17. Draft Genome Sequences of Vibrio alginolyticus Strains V1 and V2, Opportunistic Marine Pathogens

    DEFF Research Database (Denmark)

    Castillo, Daniel; D'Alvise, Paul; Kalatzis, Panos G.

    2015-01-01

    We announce the draft genome sequences of Vibrio alginolyticus strains V1 and V2, isolated from juvenile Sparus aurata and Dentex dentex, respectively, during outbreaks of vibriosis. The genome sequences are 5,257,950 bp with a G+C content of 44.5% for V. alginolyticus V1 and 5,068,299 bp with a G...

  18. Variability of Total and Pathogenic Vibrio parahaemolyticus Densities in Northern Gulf of Mexico Water and Oysters▿

    OpenAIRE

    Zimmerman, A. M.; DePaola, A.; Bowers, J. C.; Krantz, J. A.; Nordstrom, J. L.; Johnson, C. N.; Grimes, D. J.

    2007-01-01

    Vibrio parahaemolyticus is indigenous to coastal environments and a frequent cause of seafood-borne gastroenteritis in the United States, primarily due to raw-oyster consumption. Previous seasonal-cycle studies of V. parahaemolyticus have identified water temperature as the strongest environmental predictor. Salinity has also been identified, although it is evident that its effect on annual variation is not as pronounced. The effects of other environmental factors, both with respect to the se...

  19. HEAT TREATMENT FOR THE PRECOOCKED SHRIMPS PRODUCTION: VIBRIO PARAHAEMOLYTICUS RISK ANALYSIS

    Directory of Open Access Journals (Sweden)

    L. Serracca

    2010-03-01

    Full Text Available Vibrio parahaemolyticus is a common microflora of marine and estuarine waters known to be associated with gastroenteritis due to consumption of raw seafood, cooked food contaminated through direct contact (cross contamination or improperly cooked. The aim of this study was to evaluate the effectiveness of two different heat processes in reducing microbial load of V. parahaemolyticus. Data show a 4 Log10/g reduction of bacterial load after 3,30 and 15 minutes at 95 °C.

  20. A novel kit for rapid detection of Vibrio cholerae O1.

    OpenAIRE

    Hasan, J A; Huq, A; Tamplin, M L; Siebeling, R J; Colwell, R R

    1994-01-01

    We report on the development and testing of a novel, rapid, colorimetric immunodiagnostic kit, Cholera SMART, for direct detection of the presence of Vibrio cholerae O1 in clinical specimens. Unlike conventional culture methods requiring several days to complete, the Cholera SMART kit can be used directly in the field by untrained or minimally skilled personnel to detect V. cholerae O1 in less than 15 min, without cumbersome laboratory equipment. A total of 120 clinical and environmental bact...

  1. The protective activity of tea against infection by Vibrio cholerae O1.

    Science.gov (United States)

    Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Shimamura, T

    1991-02-01

    Extracts of black tea exhibited bactericidal activity against Vibrio cholerae O1. The tea extract inhibited the haemolysin activity of V. cholerae O1, El Tor and the morphological changes of Chinese hamster ovary cells induced by cholera toxin. Tea extract also reduced fluid accumulation induced by cholera toxin in sealed adult mice and by V. cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea has protective activity against V. cholerae O1.

  2. Extracellular-matrix-mediated osmotic pressure drives Vibrio cholerae biofilm expansion and cheater exclusion

    OpenAIRE

    Yan, Jing; Nadell, Carey D.; Stone, Howard A.; Wingreen, Ned S.; Bassler, Bonnie L.

    2017-01-01

    Biofilms, surface-attached communities of bacteria encased in an extracellular matrix, are a major mode of bacterial life. How the material properties of the matrix contribute to biofilm growth and robustness is largely unexplored, in particular in response to environmental perturbations such as changes in osmotic pressure. Here, using Vibrio cholerae as our model organism, we show that during active cell growth, matrix production enables biofilm-dwelling bacterial cells to establish an osmot...

  3. Quorum-sensing regulators control virulence gene expression in Vibrio cholerae

    OpenAIRE

    Zhu, Jun; Miller, Melissa B.; Vance, Russell E.; Dziejman, Michelle; Bassler, Bonnie L.; Mekalanos, John J.

    2002-01-01

    The production of virulence factors including cholera toxin and the toxin-coregulated pilus in the human pathogen Vibrio cholerae is strongly influenced by environmental conditions. The well-characterized ToxR signal transduction cascade is responsible for sensing and integrating the environmental information and controlling the virulence regulon. We show here that, in addition to the known components of the ToxR signaling circuit, quorum-sensing regulators are involved in regulation of V. ch...

  4. Incidence of Vibrio parahaemolyticus in U.S. coastal waters and oysters.

    OpenAIRE

    DePaola, A; Hopkins, L H; Peeler, J T; Wentz, B; McPhearson, R M

    1990-01-01

    Oyster and seawater samples were collected seasonally from May 1984 through April 1985 from shellfish-growing areas in Washington, California, Texas, Louisiana, Alabama, Florida, South Carolina, Virginia, and Rhode Island which had been designated as approved or prohibited by the National Shellfish Sanitation Program. Fecal coliforms counts, aerobic plate counts, and Vibrio parahaemolyticus densities were determined for the samples. Mean V. parahaemolyticus density was more than 100 times gre...

  5. Incidence of urea-hydrolyzing Vibrio parahaemolyticus in Willapa Bay, Washington.

    Science.gov (United States)

    Kaysner, C A; Abeyta, C; Stott, R F; Lilja, J L; Wekell, M M

    1990-04-01

    A high incidence (71.5%) of Vibrio parahaemolyticus was found in samples of water, oysters, and sediment from a Washington State estuary which produces a significant amount of commercial product. Strains of V. parahaemolyticus capable of hydrolyzing urea comprised 58.4% of all V. parahaemolyticus isolates tested. Values for fecal coliforms were within certification criteria for commercial harvest and were not correlated with levels of V. parahaemolyticus.

  6. BIOFILM FORMATION OF Vibrio cholerae ON STAINLESS STEEL USED IN FOOD PROCESSING

    OpenAIRE

    FERNÁNDEZ-DELGADO, Milagro; ROJAS, Héctor; DUQUE, Zoilabet; SUÁREZ, Paula; CONTRERAS, Monica; GARCÍA-AMADO, M. Alexandra; ALCIATURI, Carlos

    2016-01-01

    Vibrio cholerae represents a significant threat to human health in developing countries. This pathogen forms biofilms which favors its attachment to surfaces and its survival and transmission by water or food. This work evaluated the in vitro biofilm formation of V. cholerae isolated from clinical and environmental sources on stainless steel of the type used in food processing by using the environmental scanning electron microscopy (ESEM). Results showed no cell adhesion at 4 h and scarce sur...

  7. Transferable chloramphenicol resistance determinant in luminous Vibrio harveyi from penaeid shrimp Penaeus monodon larvae

    Directory of Open Access Journals (Sweden)

    Thangapalam Jawahar Abraham

    2016-12-01

    Full Text Available Antibiotic-resistant luminous Vibrio harveyi strains isolated from Penaeus monodon larvae were screened for the possession of transferable resistance determinants. All the strains were resistant to chloramphenicol and the determinant coding for chloramphenicol resistance was transferred to Escherichia coli at frequencies of 9.50x10-4 to 4.20x10-4. The results probably suggest the excessive use of chloramphenicol in shrimp hatcheries to combat luminous vibriosis.

  8. Monitoring of Vibrio harveyi quorum sensing activity in real time during infection of brine shrimp larvae.

    Science.gov (United States)

    Defoirdt, Tom; Sorgeloos, Patrick

    2012-12-01

    Quorum sensing, bacterial cell-to-cell communication, has been linked to the virulence of pathogenic bacteria. Indeed, in vitro experiments have shown that many bacterial pathogens regulate the expression of virulence genes by this cell-to-cell communication process. Moreover, signal molecules have been detected in samples retrieved from infected hosts and quorum sensing disruption has been reported to result in reduced virulence in different host-pathogen systems. However, data on in vivo quorum sensing activity of pathogens during infection of a host are currently lacking. We previously reported that quorum sensing regulates the virulence of Vibrio harveyi in a standardised model system with gnotobiotic brine shrimp (Artemia franciscana) larvae. Here, we monitored quorum sensing activity in Vibrio harveyi during infection of the shrimp, using bioluminescence as a read-out. We found that wild-type Vibrio harveyi shows a strong increase in quorum sensing activity early during infection. In this respect, the bacteria behave remarkably similar in different larvae, despite the fact that only half of them survive the infection. Interestingly, when expressed per bacterial cell, Vibrio harveyi showed around 200-fold higher maximal quorum sensing-regulated bioluminescence when associated with larvae than in the culture water. Finally, the in vivo quorum sensing activity of mutants defective in the production of one of the three signal molecules is consistent with their virulence, with no detectable in vivo quorum sensing activity in AI-2- and CAI-1-deficient mutants. These results indicate that AI-2 and CAI-1 are the dominant signals during infection of brine shrimp.

  9. Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1.

    OpenAIRE

    Cook, W L; Wachsmuth, K; Johnson, S R; Birkness, K A; Samadi, A R

    1984-01-01

    Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to thr...

  10. Vibrio harveyi as a causative agent of the White Syndrome in tropical stony corals.

    Science.gov (United States)

    Luna, Gian Marco; Bongiorni, Lucia; Gili, Claudia; Biavasco, Francesca; Danovaro, Roberto

    2010-02-01

    We investigated bacterial assemblages associated with corals displaying symptoms of the 'White Syndrome' (WS), a general term used for indicating the appearance of bands, spots or patches of tissue loss, which is devastating wide areas of tropical ecosystems worldwide. We collected WS-diseased (n = 15) and healthy (n = 15) corals from the natural reef (Indonesia, Indian Ocean) and from four large public aquaria. By using culture-dependent and culture-independent techniques, we found that a large fraction (73%) of the investigated WS events was associated with the presence of a high bacterial abundance and, specifically, of Vibrio spp. Vibrio harveyi, a pathogen of many marine organisms and recently involved in coral Yellow Band disease, was the most represented species, being recovered from five out of 15 diseased corals. In experimental infection assays, two V. harveyi strains, isolated from diseased corals, were inoculated on a total of 62 healthy colonies of Pocillopora damicornis. WS signs appeared in 57 corals, confirming the ability of V. harveyi strains to induce the disease. We conclude that V. harveyi is one of the coral pathogens involved in the appearance of WS. However, not all of the investigated WSs were associated to V. harveyi detection, nor to other Vibrio species (such as V. coralliilyticus), which supports the hypothesis that WS is not caused exclusively by Vibrio spp., but rather can have a multifactorial aetiology, or can represent a group of diseases caused by a variety of agents. Further investigations to identify specific virulence traits will contribute to the understanding of the role of V. harveyi in WS pathogenesis. © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.

  11. GENETIC DIVERSITY OF Vibrio harveyi ISOLATED FROM TIGER PRAWN Penaeus monodon HATCHERIES AND GROW OUT PONDS

    OpenAIRE

    Muliani Muliani; Ince Ayu Khairana Kadriah; Andi Parenrengi; Sulaeman Sulaeman

    2006-01-01

    ibrio harveyi is known as one among the most harmful bacteria infecting tiger prawn at every stage of its life’s. The present research was aimed to reveal the genetic diversity of Vibrio harveyi isolated from tiger prawn (Penaeus monodon) culture. The samples of bacteria were collected from hatchery (brood-stock, larvae, natural feed, artemia, and larval rearing water) and grow-out (juveniles, water, shrimp, sediment, plankton, crab, mollusc, microalgae, and wild fish).  The taxonomic identif...

  12. Vibrio parahemolyticus septicaemia in a liver transplant patient: a case report

    Science.gov (United States)

    2011-01-01

    Introduction Vibrio parahemolyticus is the leading cause of vibrio-associated gastroenteritis in the United States of America, usually related to poor food handling; only rarely has it been reported to cause serious infections including sepsis and soft tissue infections. In contrast, Vibrio vulnificus is a well-known cause of septicaemia, especially in patients with cirrhosis. We present a patient with V. parahemolyticus sepsis who had an orthotic liver transplant in 2007 and was on immunosuppression for chronic rejection. Clinical suspicion driven by patient presentation, travel to Gulf of Mexico and soft tissue infection resulted in early diagnosis and institution of appropriate antibiotic therapy. Case presentation A 48 year old Latin American man with a history of chronic kidney disease, orthotic liver transplant in 2007 secondary to alcoholic end stage liver disease on immunosuppressants, and chronic rejection presented to the emergency department with fever, vomiting, abdominal pain, left lower extremity swelling and fluid filled blisters after a fishing trip in the Gulf of Mexico. Samples from the blister and blood grew V. parahemolyticus. The patient was successfully treated with ceftriaxone and ciprofloxacin. Conclusion Febrile patients with underlying liver disease and/or immunosuppression should be interviewed regarding recent travel to a coastal area and seafood ingestion. If this history is obtained, appropriate empiric antibiotics must be chosen. Patients with liver disease and/or immunosuppresion should be counselled to avoid eating raw or undercooked molluscan shellfish. People can prevent Vibrio sepsis and wound infections by proper cooking of seafood and avoiding exposure of open wounds to seawater or raw shellfish products. PMID:21548914

  13. Vibrio parahemolyticus septicaemia in a liver transplant patient: a case report.

    Science.gov (United States)

    Fernando, Rajeev R; Krishnan, Sujatha; Fairweather, Morgan G; Ericsson, Charles D

    2011-05-06

    Vibrio parahemolyticus is the leading cause of vibrio-associated gastroenteritis in the United States of America, usually related to poor food handling; only rarely has it been reported to cause serious infections including sepsis and soft tissue infections. In contrast, Vibrio vulnificus is a well-known cause of septicaemia, especially in patients with cirrhosis. We present a patient with V. parahemolyticus sepsis who had an orthotic liver transplant in 2007 and was on immunosuppression for chronic rejection. Clinical suspicion driven by patient presentation, travel to Gulf of Mexico and soft tissue infection resulted in early diagnosis and institution of appropriate antibiotic therapy. A 48 year old Latin American man with a history of chronic kidney disease, orthotic liver transplant in 2007 secondary to alcoholic end stage liver disease on immunosuppressants, and chronic rejection presented to the emergency department with fever, vomiting, abdominal pain, left lower extremity swelling and fluid filled blisters after a fishing trip in the Gulf of Mexico. Samples from the blister and blood grew V. parahemolyticus. The patient was successfully treated with ceftriaxone and ciprofloxacin. Febrile patients with underlying liver disease and/or immunosuppression should be interviewed regarding recent travel to a coastal area and seafood ingestion. If this history is obtained, appropriate empiric antibiotics must be chosen. Patients with liver disease and/or immunosuppresion should be counselled to avoid eating raw or undercooked molluscan shellfish. People can prevent Vibrio sepsis and wound infections by proper cooking of seafood and avoiding exposure of open wounds to seawater or raw shellfish products.

  14. Vibrio parahemolyticus septicaemia in a liver transplant patient: a case report

    Directory of Open Access Journals (Sweden)

    Fairweather Morgan G

    2011-05-01

    Full Text Available Abstract Introduction Vibrio parahemolyticus is the leading cause of vibrio-associated gastroenteritis in the United States of America, usually related to poor food handling; only rarely has it been reported to cause serious infections including sepsis and soft tissue infections. In contrast, Vibrio vulnificus is a well-known cause of septicaemia, especially in patients with cirrhosis. We present a patient with V. parahemolyticus sepsis who had an orthotic liver transplant in 2007 and was on immunosuppression for chronic rejection. Clinical suspicion driven by patient presentation, travel to Gulf of Mexico and soft tissue infection resulted in early diagnosis and institution of appropriate antibiotic therapy. Case presentation A 48 year old Latin American man with a history of chronic kidney disease, orthotic liver transplant in 2007 secondary to alcoholic end stage liver disease on immunosuppressants, and chronic rejection presented to the emergency department with fever, vomiting, abdominal pain, left lower extremity swelling and fluid filled blisters after a fishing trip in the Gulf of Mexico. Samples from the blister and blood grew V. parahemolyticus. The patient was successfully treated with ceftriaxone and ciprofloxacin. Conclusion Febrile patients with underlying liver disease and/or immunosuppression should be interviewed regarding recent travel to a coastal area and seafood ingestion. If this history is obtained, appropriate empiric antibiotics must be chosen. Patients with liver disease and/or immunosuppresion should be counselled to avoid eating raw or undercooked molluscan shellfish. People can prevent Vibrio sepsis and wound infections by proper cooking of seafood and avoiding exposure of open wounds to seawater or raw shellfish products.

  15. Depressed light emission by symbiotic Vibrio fischeri of the sepiolid squid Euprymna scolopes.

    OpenAIRE

    Boettcher, K J; Ruby, E G

    1990-01-01

    Bioluminescent marine bacteria of the species Vibrio fischeri are the specific light organ symbionts of the sepiolid squid Euprymna scolopes. Although they share morphological and physiological characteristics with other strains of V. fischeri, when cultured away from the light organ association the E. scolopes symbionts depress their maximal luminescence over 1,000-fold. The primary cause of this reduced luminescence is the underproduction by these bacteria of luciferase autoinducer, a molec...

  16. Competition between Vibrio fischeri strains during initiation and maintenance of a light organ symbiosis.

    OpenAIRE

    Lee, K H; Ruby, E G

    1994-01-01

    Colonization of the light-emitting organ of the Hawaiian squid Euprymna scolopes is initiated when the nascent organ of a newly hatched squid becomes inoculated with Vibrio fischeri cells present in the ambient seawater. Although they are induced for luminescence in the light organ, these symbiotic strains are characteristically non-visibly luminous (NVL) when grown in laboratory culture. The more typical visibly luminous (VL) type of V. fischeri co-occurs in Hawaiian seawater with these NVL ...

  17. Combined treatment of UVA irradiation and antibiotics induces greater bactericidal effects on Vibrio parahaemolyticus

    OpenAIRE

    Hou, Yanfei; Nakahashi, Mutsumi; Mawatari, Kazuaki; Shimohata, Takaaki; Uebanso, Takashi; Harada, Yumi; Tsunedomi, Akari; Emoto, Takahiro; Akutagawa, Masatake; Kinouchi, Yohsuke; Takahashi, Akira

    2016-01-01

    The presence of antibiotics in the environment and their subsequent impact on the development of multi-antibiotic resistant bacteria has raised concerns globally. Consequently, much research is focused on a method to produce a better disinfectant. We have established a disinfectant system using UVA-LED that inactivates pathogenic bacteria. We assessed the bactericidal efficiency of a combination of UVA-LED and antibiotics against Vibrio parahaemolyticus. Combined use of antibiotic drugs and U...

  18. Complete Genome Sequence of Vibrio campbellii LMB 29 Isolated from Red Drum with Four Native Megaplasmids

    Directory of Open Access Journals (Sweden)

    Jinxin Liu

    2017-10-01

    Full Text Available Vibrio spp. are the most common pathogens for animals reared in aquaculture. Vibrio campbellii, which is often involved in shrimp, fish and mollusks diseases, is widely distributed in the marine environment worldwide, but our knowledge about its pathogenesis and antimicrobial resistance is very limited. The existence of this knowledge gap is at least partially because that V. campbellii was originally classified as Vibrio harveyi, and the detailed information of its comparative genome analysis to other Vibrio spp. is currently lacking. In this study, the complete genome of a V. campbellii predominant strain, LMB29, was determined by MiSeq in conjunction with PacBio SMRT sequencing. This genome consists of two circular DNA chromosomes and four megaplasmids. Comparative genome analysis indicates that LMB29 shares a 96.66% similarity (average nucleotide identity with the V. campbellii ATCC strain BAA-1116 based on a 75% AF (average fraction calculations, and its functional profile is very similar to V. campbellii E1 and V. campbellii CAIM115. Both type III secretion system (T3SS and type VI secretion system (T6SS, along with the tlh gene which encodes a thermolabile hemolysin, are present in LMB29 which may contribute to the bacterial pathogenesis. The virulence of this strain was experimental confirmed by performing a LDH assay on a fish cell infection model, and cell death was observed as early as within 3 h post infection. Thirty-seven antimicrobial resistance genes (>45% identity were predicted in LMB29 which includes a novel rifampicin ADP ribosyltransferase, arr-9, in plasmid pLMB157. The gene arr-9 was predicted on a genomic island with horizontal transferable potentials which may facilitate the rifampicin resistance dissemination. Future researches are needed to explore the pathogenesis of V. campbellii LMB29, but the availability of this genome sequence will certainly aid as a basis for further analysis.

  19. A quorum sensing-mediated switch contributes to natural transformation of Vibrio cholerae

    OpenAIRE

    Blokesch Melanie

    2013-01-01

    There is a fundamental gap in our understanding of how horizontal gene transfer contributes to the enormous range of genetic variations that are observed among bacteria. The objective of our study was to better understand how the acquisition of genetic material by natural transformation is regulated within a population of Vibrio cholerae cells. V. cholerae is an aquatic bacterium and a facultative human pathogen. It acquires natural competence for transformation in response to changing enviro...

  20. Distribution and survival of Vibrio vulnificus genotypes in postharvest Gulf Coast (USA) oysters under refrigeration.

    Science.gov (United States)

    Wood, R R; Arias, C R

    2012-07-01

      The effect of refrigeration on the seafood-borne pathogen Vibrio vulnificus was investigated in terms of genotype selection and persistence in refrigerated oysters.   Naturally occurring numbers of V. vulnificus in oysters from two different locations were compared during a 2-week period under refrigeration conditions. At different time points, V. vulnificus isolates were recovered from oysters and ascribed to 16S rRNA gene type A, B or AB using restriction fragment length polymorphism. Initial V. vulnificus numbers were higher than 10(4) most probable number (MPN) g(-1) and remained unchanged throughout the duration of the study. 16S rRNA gene type B isolates accounted for 53% of the isolates recovered. Amplified fragment length polymorphism analysis confirmed the high genetic variability previously observed within this species but revealed the presence of two main genetic groups within the species that matched 16S rRNA gene ascription.   Vibrio vulnificus numbers in oysters did not significantly declined over the shelf life of the product and refrigeration did not select for specific V. vulnificus types.   The prevalence of V. vulnificus 16S rRNA gene type B in oysters was higher than previously reported from the same geographic area and was not significantly reduced during the storage period. Vibrio vulnificus is divided into two clear genotypes, regardless of the genetic marker used. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  1. A single regulatory gene is sufficient to alter Vibrio aestuarianus pathogenicity in oysters.

    Science.gov (United States)

    Goudenège, David; Travers, Marie Agnès; Lemire, Astrid; Petton, Bruno; Haffner, Philippe; Labreuche, Yannick; Tourbiez, Delphine; Mangenot, Sophie; Calteau, Alexandra; Mazel, Didier; Nicolas, Jean Louis; Jacq, Annick; Le roux, Frédérique

    2015-11-01

    Oyster diseases caused by pathogenic vibrios pose a major challenge to the sustainability of oyster farming. In France, since 2012 a disease affecting specifically adult oysters has been associated with the presence of Vibrio aestuarianus. Here, by combining genome comparison, phylogenetic analyses and high-throughput infections of strains isolated before or during the recent outbreaks, we show that virulent strains cluster into two V. aestuarianus lineages independently of the sampling dates. The bacterial lethal dose was not different between strains isolated before or after 2012. Hence, the emergence of a new highly virulent clonal strain is unlikely. Each lineage comprises nearly identical strains, the majority of them being virulent, suggesting that within these phylogenetically coherent virulent lineages a few strains have lost their pathogenicity. Comparative genomics allowed the identification of a single frameshift in a non-virulent strain. This mutation affects the varS gene that codes for a signal transduction histidine-protein kinase. Genetic analyses confirmed that varS is necessary for infection of oysters and for a secreted metalloprotease expression. For the first time in a Vibrio species, we show here that VarS is a key factor of pathogenicity. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  2. Development of a recombinase polymerase amplification assay for Vibrio parahaemolyticus detection with an internal amplification control.

    Science.gov (United States)

    Yang, Huan-Lan; Wei, Shuang; Gooneratne, Ravi; Mutukumira, Anthony N; Ma, Xue-Jun; Tang, Shu-Ze; Wu, Xi-Yang

    2018-04-01

    A novel RPA-IAC assay using recombinase polymerase and an internal amplification control (IAC) for Vibrio parahaemolyticus detection was developed. Specific primers were designed based on the coding sequence for the toxR gene in V. parahaemolyticus. The recombinase polymerase amplification (RPA) reaction was conducted at a constant low temperature of 37 °C for 20 min. Assay specificity was validated by using 63 Vibrio strains and 10 non-Vibrio bacterial species. In addition, a competitive IAC was employed to avoid false-negative results, which co-amplified simultaneously with the target sequence. The sensitivity of the assay was determined as 3 × 10 3 CFU/mL, which is decidedly more sensitive than the established PCR method. This method was then used to test seafood samples that were collected from local markets. Seven out of 53 different raw seafoods were detected as V. parahaemolyticus-positive, which were consistent with those obtained using traditional culturing method and biochemical assay. This novel RPA-IAC assay provides a rapid, specific, sensitive, and more convenient detection method for V. parahaemolyticus.

  3. In vitro interactions of Acanthamoeba castellanii Neff and Vibrio harveyi.

    Science.gov (United States)

    Reyes-Batlle, María; Martín-Rodríguez, Alberto J; López-Arencibia, Atteneri; Sifaoui, Ines; Liendo, Aitor Rizo; Bethencourt Estrella, Carlos J; García Méndez, Ana B; Chiboub, Olfa; Hajaji, Soumaya; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Lorenzo-Morales, Jacob

    2017-12-01

    Free-living amoebae (FLA) are opportunistic protozoa widely distributed in the environment. They are frequently found in water and soil samples, but they have also been reported to be associated with bacterial human pathogens such as Legionella spp. Campylobacter spp or Vibrio cholerae among others. Including within Vibrio spp. V. harveyi (Johnson and Shunk, 1936) is a bioluminescent marine bacteria which has been found swimming freely in tropical marine waters, being part of the stomach and intestine microflora of marine animals, and as both a primary and opportunistic pathogen of marine animals. Our aim was to study the interactions between Vibrio harveyi and Acanthamoeba castellanii Neff. Firstly, in order to analyze changes in it cultivability, V. harveyi was coincubated with A. castellanii Neff axenic culture and with Acanthamoeba Conditioned Medium (ACM) at different temperatures in aerobic conditions. Interestingly, at 4 °C and 18-20 °C bacteria were still cultivable in marine agar, at 28 °C, in aerobic conditions, but there weren't significant differences comparing with the controls. We also noted an enhanced migration of Acanthamoeba toward V. harveyi on non-nutrient agar plates compared to controls with no bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Chemical and structural characterization of hydroxamate siderophore produced by marine Vibrio harveyi.

    Science.gov (United States)

    Murugappan, R M; Aravinth, A; Karthikeyan, M

    2011-02-01

    In the present study, 22 different bacteria were isolated from open ocean water from the Gulf of Mannar, India. Of the 22 isolates, 4 were identified as Vibrio spp. (VM1, VM2, VM3 and VM4) and found to produce siderophores (iron-binding chelators) under iron-limited conditions. Different media were found to have an influence on siderophore production. Maximum siderophore production was observed with VM1 isolate in MM9 salts medium at 48 h of incubation. The isolate was confirmed as Vibrio harveyi based on 16S rRNA gene sequencing and phylogenetic analysis. Fourier-transform infrared (FTIR) and (1)H nuclear magnetic resonance (NMR) spectra revealed the hydroxamate nature of the siderophore produced. Further characterization of the siderophore revealed it to be of dihydroxamate nature, forming hexadentate ligands with Fe(III) ions. A narrow shift in ultraviolet (UV)-Vis spectrum was observed on photolysis due to ligand oxidation. Growth-promotion bioassay with Aeromonas hydrophila, Staphylococcus aureus and E. coli confirmed the iron-scavenging property of the siderophore produced by Vibrio harveyi.

  5. Molecular variations in Vibrio alginolyticus and V. harveyi in shrimp-farming systems upon stress

    Directory of Open Access Journals (Sweden)

    Anix Vivek Santhyia

    2015-01-01

    Full Text Available A study was performed to investigate the genomic variations in the shrimp farm isolates of Vibrio alginolyticus and V. harveyi when the isolates were subjected to environmental stress. Samples of shrimps, water and sediment were collected from Southern Indian coastal shrimp farms. Vibrio isolates were biochemically identified and confirmed using 16S rDNA and gyrB gene specific PCR. The bacterial strains were genotyped by PCR fingerprinting using GTG(5 and IS (Insertion Sequence primers. Seven strains each of V. alginolyticus and V. harveyi were subjected to 10 passages through trypticase soya broth (TSB, which contained different NaCl concentrations (3, 6 and 8% and trypticase soya agar (TSA. V. alginolyticus was also passaged through TSB with a 12% NaCl concentration. PCR fingerprinting, which was performed on the strains that were passaged through different salt concentrations, confirmed that V. alginolyticus and V. harveyi could affect the genomic variations, depending on the environmental conditions of the culture. The study highlights the complex genotypic variations that occur in Vibrio strains of tropical aquatic environment because of varied environmental conditions, which result in genetic divergence and/or probable convergence. Such genetic divergence and/or convergence can lead to the organismal adaptive variation, which results in their ability to cause a productive infection in aquatic organisms or generation of new strains.

  6. Vibrio Species in Wastewater Final Effluents and Receiving Watershed in South Africa: Implications for Public Health

    Directory of Open Access Journals (Sweden)

    Allisen N. Okeyo

    2018-06-01

    Full Text Available Wastewater treatment facilities in South Africa are obliged to make provision for wastewater effluent quality management, with the aim of securing the integrity of the surrounding watersheds and environments. The Department of Water Affairs has documented regulatory parameters that have, over the years, served as a guideline for quality monitoring/management purposes. However, these guidelines have not been regularly updated and this may have contributed to some of the water quality anomalies. Studies have shown that promoting the monitoring of the current routinely monitored parameters (both microbial and physicochemical may not be sufficient. Organisms causing illnesses or even outbreaks, such as Vibrio pathogens with their characteristic environmental resilience, are not included in the guidelines. In South Africa, studies that have been conducted on the occurrence of Vibrio pathogens in domestic and wastewater effluent have made it apparent that these pathogens should also be monitored. The importance of effective wastewater management as one of the key aspects towards protecting surrounding environments and receiving watersheds, as well as protecting public health, is highlighted in this review. Emphasis on the significance of the Vibrio pathogen in wastewater is a particular focus.

  7. [Development of the soft independent modelling of class analogies model to discrimination Vibrio parahemolyticus by Smartongue].

    Science.gov (United States)

    Huang, Jianfeng; Zhao, Guangying; Dou, Wenchao

    2011-04-01

    To explore a new rapid detection method for detecting of Food pathogens. We used the Smartongue, to determine the composition informations of the liquid culture samples and combined with soft independent modelling of class analogies (SIMCA) to analyze their respective species, then set up a Smartongue -SIMCA model to discriminate the V. parahaemolyticus. The Smartongue has 6 working electrodes and three frequency segments, we can built 18 discrimination models in one detection. After comparing all the 18 discrimination models, the optimal working electrodes and frequency segments were selected out, they were: palladium electrode in 1 Hz frequency segment, tungsten electrode in 100 Hz and silver electrode in 100 Hz. Then 10 species of pathogenic Vibrio were discriminated by the 3 models. The V. damsela, V. metschnikovii, V. alginalyticus, V. cincinnatiensis, V. metschnikovii and V. cholerae O serogroup samples could be discriminated by the SIMCA model of V. parahaemolyticus with palladium electrode 1 Hz frequency segment; V. mimicus and V. vulnincus samples could be discriminated by the SIMCA model of V. parahaemolyticus with tungsten electrode 100 Hz frequency segment; V. carcariae and V. cholerae non-O serogroup samples could be discriminated with the SIMCA model of V. parahaemolyticus in silver electrode 100 Hz frequency segment. The accurate discrimination of ten species of Vibrio samples is 100%. The Smartongue combined with SIMCA can discriminate V. parahaemolyticus with other pathogenic Vibrio effectively. It has a promising future as a new rapid detection method for V. parahaemolyticus.

  8. Two type IV pili of Vibrio parahaemolyticus play different roles in biofilm formation.

    Science.gov (United States)

    Shime-Hattori, Akiko; Iida, Tetsuya; Arita, Michiko; Park, Kwon-Sam; Kodama, Toshio; Honda, Takeshi

    2006-11-01

    Vibrio parahaemolyticus RIMD2210633 has two sets of type IV-A pilus genes. One set is similar to that found in other Gram-negative bacteria, such as Pseudomonas aeruginosa, Vibrio cholerae (chitin-regulated pilus; ChiRP), and Vibrio vulnificus. The other is homologous to the genes for the mannose-sensitive hemagglutinin (MSHA) pilus. In this study, we analyzed the effects of the deletions in the pilin genes for each type IV pilus (the ChiRP and the MSHA pilus) on biofilm formation. Although the MSHA pilin mutant formed aggregates, the number of bacteria that attached directly to the coverslip was reduced, suggesting that this pilus contributes to the bacterial attachment to the surface of the coverslip. In contrast, the ChiRP mutant attached to the surface of the coverslip, but did not form aggregates, suggesting that ChiRP plays a role in bacterial agglutination during biofilm formation. These results suggest that the two type IV pili of V. parahaemolyticus contribute to biofilm formation in different ways. Both mutants showed a lower fitness for adsorption onto chitin particles than that of the wild type. Collectively, these data suggest that the use of two type IV pili is a refined strategy of V. parahaemolyticus for survival in natural environments.

  9. Acetone Formation in the Vibrio Family: a New Pathway for Bacterial Leucine Catabolism

    Science.gov (United States)

    Nemecek-Marshall, Michele; Wojciechowski, Cheryl; Wagner, William P.; Fall, Ray

    1999-01-01

    There is current interest in biological sources of acetone, a volatile organic compound that impacts atmospheric chemistry. Here, we determined that leucine-dependent acetone formation is widespread in the Vibrionaceae. Sixteen Vibrio isolates, two Listonella species, and two Photobacterium angustum isolates produced acetone in the presence of l-leucine. Shewanella isolates produced much less acetone. Growth of Vibrio splendidus and P. angustum in a fermentor with controlled aeration revealed that acetone was produced after a lag in late logarithmic or stationary phase of growth, depending on the medium, and was not derived from acetoacetate by nonenzymatic decarboxylation in the medium. l-Leucine, but not d-leucine, was converted to acetone with a stoichiometry of approximately 0.61 mol of acetone per mol of l-leucine. Testing various potential leucine catabolites as precursors of acetone showed that only α-ketoisocaproate was efficiently converted by whole cells to acetone. Acetone production was blocked by a nitrogen atmosphere but not by electron transport inhibitors, suggesting that an oxygen-dependent reaction is required for leucine catabolism. Metabolic labeling with deuterated (isopropyl-d7)-l-leucine revealed that the isopropyl carbons give rise to acetone with full retention of deuterium in each methyl group. These results suggest the operation of a new catabolic pathway for leucine in vibrios that is distinct from the 3-hydroxy-3-methylglutaryl-coenzyme A pathway seen in pseudomonads. PMID:10601206

  10. Isolation and molecular identification of Vibrio spp. by sequencing of 16S rDNA from seafood, meat and meat products in Libya

    Science.gov (United States)

    Azwai, S.M.; Alfallani, E.A.; Abolghait, S.K.; Garbaj, A.M.; Naas, H.T.; Moawad, A.A.; Gammoudi, F.T.; Rayes, H.M.; Barbieri, I.; Eldaghayes, I.M.

    2016-01-01

    The genus Vibrio includes several food-borne pathogens that cause a spectrum of clinical conditions including septicemia, cholera and milder forms of gastroenteritis. Several Vibrio spp. are commonly associated with food-borne transmission including Vibrio cholerae, Vibrio parahemolyticus, and Vibrio vulnificus. Microbiological analysis for enumeration and isolation of Vibrio spp. were carried out for a total of 93 samples of seafood, meat and meat products from different geographic localities in Libya (Tripoli, Regdalin, Janzour and Tobruk). Vibrio spp. were detected by conventional cultural and molecular method using PCR and sequencing of 16S rDNA. Out of the 93 cultured samples only 48 (51.6%) yielded colonies on Thiosulfate Citrate Bile Salt agar (TCBS) with culture characteristics of Vibrio spp. More than half (n=27) of processed seafood samples (n=46) yielded colonies on TCBS, while only 44.6 % of samples of meat and meat products showed colonies on TCBS. Among cultured seafood samples, the highest bacterial count was recorded in clam with a count of 3.8 ×104 CFU\\g. Chicken burger samples showed the highest bacterial count with 6.5 ×104 CFU\\g. Molecular analysis of the isolates obtained in this study, showed that 11 samples out of 48 (22.9%) were Vibrio spp. Vibrio parahemolyticus was isolated from camel meat for the first time. This study is an initial step to provide a baseline for future molecular research targeting Vibrio spp. foodborne illnesses. This data will be used to provide information on the magnitude of such pathogens in Libyan seafood, meat and meat products. PMID:27004169

  11. Isolation and molecular identification of Vibrio spp. by sequencing of 16S rDNA from seafood, meat and meat products in Libya

    Directory of Open Access Journals (Sweden)

    S.M. Azwai

    2016-03-01

    Full Text Available The genus Vibrio includes several food-borne pathogens that cause a spectrum of clinical conditions including septicemia, cholera and milder forms of gastroenteritis. Several Vibrio spp. are commonly associated with food-borne transmission including Vibrio cholerae, Vibrio parahemolyticus, and Vibrio vulnificus. Microbiological analysis for enumeration and isolation of Vibrio spp. were carried out for a total of 93 samples of seafood, meat and meat products from different geographic localities in Libya (Tripoli, Regdalin, Janzour and Tobruk. Vibrio spp. were detected by conventional cultural and molecular method using PCR and sequencing of 16S rDNA. Out of the 93 cultured samples only 48 (51.6% yielded colonies on Thiosulfate Citrate Bile Salt agar (TCBS with culture characteristics of Vibrio spp. More than half (n=27 of processed seafood samples (n=46 yielded colonies on TCBS, while only 44.6% of samples of meat and meat products showed colonies on TCBS. Among cultured seafood samples, the highest bacterial count was recorded in clam with a count of 3.8 х104 CFU\\g. Chicken burger samples showed the highest bacterial count with 6.5 х104 CFU\\g. Molecular analysis of the isolates obtained in this study, showed that 11 samples out of 48 (22.9% were Vibrio spp. Vibrio parahemolyticus was isolated from camel meat for the first time. This study is an initial step to provide a baseline for future molecular research targeting Vibrio spp. foodborne illnesses. This data will be used to provide information on the magnitude of such pathogens in Libyan seafood, meat and meat products.

  12. Isolation and molecular identification of Vibrio spp. by sequencing of 16S rDNA from seafood, meat and meat products in Libya.

    Science.gov (United States)

    Azwai, S M; Alfallani, E A; Abolghait, S K; Garbaj, A M; Naas, H T; Moawad, A A; Gammoudi, F T; Rayes, H M; Barbieri, I; Eldaghayes, I M

    2016-01-01

    The genus Vibrio includes several food-borne pathogens that cause a spectrum of clinical conditions including septicemia, cholera and milder forms of gastroenteritis. Several Vibrio spp. are commonly associated with food-borne transmission including Vibrio cholerae, Vibrio parahemolyticus, and Vibrio vulnificus. Microbiological analysis for enumeration and isolation of Vibrio spp. were carried out for a total of 93 samples of seafood, meat and meat products from different geographic localities in Libya (Tripoli, Regdalin, Janzour and Tobruk). Vibrio spp. were detected by conventional cultural and molecular method using PCR and sequencing of 16S rDNA. Out of the 93 cultured samples only 48 (51.6%) yielded colonies on Thiosulfate Citrate Bile Salt agar (TCBS) with culture characteristics of Vibrio spp. More than half (n=27) of processed seafood samples (n=46) yielded colonies on TCBS, while only 44.6 % of samples of meat and meat products showed colonies on TCBS. Among cultured seafood samples, the highest bacterial count was recorded in clam with a count of 3.8 ×10(4) CFU\\g. Chicken burger samples showed the highest bacterial count with 6.5 ×10(4) CFU\\g. Molecular analysis of the isolates obtained in this study, showed that 11 samples out of 48 (22.9%) were Vibrio spp. Vibrio parahemolyticus was isolated from camel meat for the first time. This study is an initial step to provide a baseline for future molecular research targeting Vibrio spp. foodborne illnesses. This data will be used to provide information on the magnitude of such pathogens in Libyan seafood, meat and meat products.

  13. A mathematical model and quantitative comparison of the small RNA circuit in the Vibrio harveyi and Vibrio cholerae quorum sensing systems

    International Nuclear Information System (INIS)

    Hunter, G A M; Vasquez, F Guevara; Keener, J P

    2013-01-01

    Quorum sensing is the process by which bacteria regulate their gene expression based on the local cell-population density. The quorum sensing systems of Vibrio harveyi and Vibrio cholerae are comprised of a phosphorelay cascade coupled to a small RNA (sRNA) circuit. The sRNA circuit contains multiple quorum regulated small RNA (Qrr) that regulate expression of the homologous master transcriptional regulators LuxR (in V. harveyi) and HapR (in V. cholerae). Their quorum sensing systems are topologically similar and homologous thereby making it difficult to understand why repression of HapR is more robust than LuxR to changes in Qrr. In this work we formulate and parameterize a novel mathematical model of the V. harveyi and V. cholerae sRNA circuit. We parameterize the model by fitting it to a variety of empirical data from both species. We show that we can distinguish all of the parameters and that the parameterizations (one for each species) are robust to errors in the data. We then use our model to propose some experiments to identify and explain kinetic differences between the species. We find that V. cholerae Qrr are more abundant and more sensitive to changes in LuxO than V. harveyi Qrr and argue that this is why expression of HapR is more robust than LuxR to changes in Qrr. (paper)

  14. Anaerobic respiratory growth of Vibrio harveyi, Vibrio fischeri and Photobacterium leiognathi with trimethylamine N-oxide, nitrate and fumarate: ecological implications.

    Science.gov (United States)

    Proctor, L M; Gunsalus, R P

    2000-08-01

    Two symbiotic species, Photobacterium leiognathi and Vibrio fischeri, and one non-symbiotic species, Vibrio harveyi, of the Vibrionaceae were tested for their ability to grow by anaerobic respiration on various electron acceptors, including trimethylamine N-oxide (TMAO) and dimethylsulphoxide (DMSO), compounds common in the marine environment. Each species was able to grow anaerobically with TMAO, nitrate or fumarate, but not with DMSO, as an electron acceptor. Cell growth under microaerophilic growth conditions resulted in elevated levels of TMAO reductase, nitrate reductase and fumarate reductase activity in each strain, whereas growth in the presence of the respective substrate for each enzyme further elevated enzyme activity. TMAO reductase specific activity was the highest of all the reductases. Interestingly, the bacteria-colonized light organs from the two squids, Euprymna scolopes and Euprymna morsei, and the light organ of the ponyfish, Leiognathus equus, also had high levels of TMAO reductase enzyme activity, in contrast to non-symbiotic tissues. The ability of these bacterial symbionts to support cell growth by respiration with TMAO may conceivably eliminate the competition for oxygen needed for both bioluminescence and metabolism.

  15. Brassinosteroids Antagonize Gibberellin- and Salicylate-Mediated Root Immunity in Rice1[C][W][OA

    Science.gov (United States)

    De Vleesschauwer, David; Van Buyten, Evelien; Satoh, Kouji; Balidion, Johny; Mauleon, Ramil; Choi, Il-Ryong; Vera-Cruz, Casiana; Kikuchi, Shoshi; Höfte, Monica

    2012-01-01

    Brassinosteroids (BRs) are a unique class of plant steroid hormones that orchestrate myriad growth and developmental processes. Although BRs have long been known to protect plants from a suite of biotic and abiotic stresses, our understanding of the underlying molecular mechanisms is still rudimentary. Aiming to further decipher the molecular logic of BR-modulated immunity, we have examined the dynamics and impact of BRs during infection of rice (Oryza sativa) with the root oomycete Pythium graminicola. Challenging the prevailing view that BRs positively regulate plant innate immunity, we show that P. graminicola exploits BRs as virulence factors and hijacks the rice BR machinery to inflict disease. Moreover, we demonstrate that this immune-suppressive effect of BRs is due, at least in part, to negative cross talk with salicylic acid (SA) and gibberellic acid (GA) pathways. BR-mediated suppression of SA defenses occurred downstream of SA biosynthesis, but upstream of the master defense regulators NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 and OsWRKY45. In contrast, BR alleviated GA-directed immune responses by interfering at multiple levels with GA metabolism, resulting in indirect stabilization of the DELLA protein and central GA repressor SLENDER RICE1 (SLR1). Collectively, these data favor a model whereby P. graminicola coopts the plant BR pathway as a decoy to antagonize effectual SA- and GA-mediated defenses. Our results highlight the importance of BRs in modulating plant immunity and uncover pathogen-mediated manipulation of plant steroid homeostasis as a core virulence strategy. PMID:22353574

  16. Brassinosteroids antagonize gibberellin- and salicylate-mediated root immunity in rice.

    Science.gov (United States)

    De Vleesschauwer, David; Van Buyten, Evelien; Satoh, Kouji; Balidion, Johny; Mauleon, Ramil; Choi, Il-Ryong; Vera-Cruz, Casiana; Kikuchi, Shoshi; Höfte, Monica

    2012-04-01

    Brassinosteroids (BRs) are a unique class of plant steroid hormones that orchestrate myriad growth and developmental processes. Although BRs have long been known to protect plants from a suite of biotic and abiotic stresses, our understanding of the underlying molecular mechanisms is still rudimentary. Aiming to further decipher the molecular logic of BR-modulated immunity, we have examined the dynamics and impact of BRs during infection of rice (Oryza sativa) with the root oomycete Pythium graminicola. Challenging the prevailing view that BRs positively regulate plant innate immunity, we show that P. graminicola exploits BRs as virulence factors and hijacks the rice BR machinery to inflict disease. Moreover, we demonstrate that this immune-suppressive effect of BRs is due, at least in part, to negative cross talk with salicylic acid (SA) and gibberellic acid (GA) pathways. BR-mediated suppression of SA defenses occurred downstream of SA biosynthesis, but upstream of the master defense regulators NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 and OsWRKY45. In contrast, BR alleviated GA-directed immune responses by interfering at multiple levels with GA metabolism, resulting in indirect stabilization of the DELLA protein and central GA repressor SLENDER RICE1 (SLR1). Collectively, these data favor a model whereby P. graminicola coopts the plant BR pathway as a decoy to antagonize effectual SA- and GA-mediated defenses. Our results highlight the importance of BRs in modulating plant immunity and uncover pathogen-mediated manipulation of plant steroid homeostasis as a core virulence strategy.

  17. Abscisic Acid-Cytokinin Antagonism Modulates Resistance Against Pseudomonas syringae in Tobacco.

    Science.gov (United States)

    Großkinsky, Dominik K; van der Graaff, Eric; Roitsch, Thomas

    2014-12-01

    Phytohormones are known as essential regulators of plant defenses, with ethylene, jasmonic acid, and salicylic acid as the central immunity backbone, while other phytohormones have been demonstrated to interact with this. Only recently, a function of the classic phytohormone cytokinin in plant immunity has been described in Arabidopsis, rice, and tobacco. Although interactions of cytokinins with salicylic acid and auxin have been indicated, the complete network of cytokinin interactions with other immunity-relevant phytohormones is not yet understood. Therefore, we studied the interaction of kinetin and abscisic acid as a negative regulator of plant immunity to modulate resistance in tobacco against Pseudomonas syringae. By analyzing infection symptoms, pathogen proliferation, and accumulation of the phytoalexin scopoletin as a key mediator of kinetin-induced resistance in tobacco, antagonistic interaction of these phytohormones in plant immunity was identified. Kinetin reduced abscisic acid levels in tobacco, while increased abscisic acid levels by exogenous application or inhibition of abscisic acid catabolism by diniconazole neutralized kinetin-induced resistance. Based on these results, we conclude that reduction of abscisic acid levels by enhanced abscisic acid catabolism strongly contributes to cytokinin-mediated resistance effects. Thus, the identified cytokinin-abscisic acid antagonism is a novel regulatory mechanism in plant immunity.

  18. Salicylic acid antagonizes abscisic acid inhibition of shoot growth and cell cycle progression in rice

    Science.gov (United States)

    Meguro, Ayano; Sato, Yutaka

    2014-04-01

    We analysed effects of abscisic acid (ABA, a negative regulatory hormone), alone and in combination with positive or neutral hormones, including salicylic acid (SA), on rice growth and expression of cell cycle-related genes. ABA significantly inhibited shoot growth and induced expression of OsKRP4, OsKRP5, and OsKRP6. A yeast two-hybrid assay showed that OsKRP4, OsKRP5, and OsKRP6 interacted with OsCDKA;1 and/or OsCDKA;2. When SA was simultaneously supplied with ABA, the antagonistic effect of SA completely blocked ABA inhibition. SA also blocked ABA inhibition of DNA replication and thymidine incorporation in the shoot apical meristem. These results suggest that ABA arrests cell cycle progression by inducing expression of OsKRP4, OsKRP5, and OsKRP6, which inhibit the G1/S transition, and that SA antagonizes ABA by blocking expression of OsKRP genes.

  19. Conditions that Stabilize Membrane Domains Also Antagonize n-Alcohol Anesthesia

    Science.gov (United States)

    Machta, Benjamin B.; Gray, Ellyn; Nouri, Mariam; McCarthy, Nicola L. C.; Gray, Erin M.; Miller, Ann L.; Brooks, Nicholas J.; Veatch, Sarah L.

    2016-08-01

    Diverse molecules induce general anesthesia with potency strongly correlated both with their hydrophobicity and their effects on certain ion channels. We recently observed that several n-alcohol anesthetics inhibit heterogeneity in plasma membrane derived vesicles by lowering the critical temperature ($T_c$) for phase separation. Here we exploit conditions that stabilize membrane heterogeneity to further test the correlation between the anesthetic potency of n-alcohols and effects on $T_c$. First we show that hexadecanol acts oppositely to n-alcohol anesthetics on membrane mixing and antagonizes ethanol induced anesthesia in a tadpole behavioral assay. Second, we show that two previously described `intoxication reversers' raise $T_c$ and counter ethanol's effects in vesicles, mimicking the findings of previous electrophysiological and behavioral measurements. Third, we find that hydrostatic pressure, long known to reverse anesthesia, also raises $T_c$ in vesicles with a magnitude that counters the effect of butanol at relevant concentrations and pressures. Taken together, these results demonstrate that $\\Delta T_c$ predicts anesthetic potency for n-alcohols better than hydrophobicity in a range of contexts, supporting a mechanistic role for membrane heterogeneity in general anesthesia.

  20. TRPV1 Antagonism by Capsazepine Modulates Innate Immune Response in Mice Infected with Plasmodium berghei ANKA

    Directory of Open Access Journals (Sweden)

    Elizabeth S. Fernandes

    2014-01-01

    Full Text Available Thousands of people suffer from severe malaria every year. The innate immune response plays a determinant role in host’s defence to malaria. Transient receptor potential vanilloid 1 (TRPV1 modulates macrophage-mediated responses in sepsis, but its role in other pathogenic diseases has never been addressed. We investigated the effects of capsazepine, a TRPV1 antagonist, in malaria. C57BL/6 mice received 105 red blood cells infected with Plasmodium berghei ANKA intraperitoneally. Noninfected mice were used as controls. Capsazepine or vehicle was given intraperitoneally for 6 days. Mice were culled on day 7 after infection and blood and spleen cell phenotype and activation were evaluated. Capsazepine decreased circulating but not spleen F4/80+Ly6G+ cell numbers as well as activation of both F4/80+and F4/80+Ly6G+ cells in infected animals. In addition, capsazepine increased circulating but not spleen GR1+ and natural killer (NK population, without interfering with natural killer T (NKT cell numbers and blood NK and NKT activation. However, capsazepine diminished CD69 expression in spleen NKT but not NK cells. Infection increased lipid peroxidation and the release of TNFα and IFNγ, although capsazepine-treated group exhibited lower levels of lipid peroxidation and TNFα. Capsazepine treatment did not affect parasitaemia. Overall, TRPV1 antagonism modulates the innate immune response to malaria.

  1. A Soluble Fluorescent Binding Assay Reveals PIP2 Antagonism of TREK-1 Channels

    Directory of Open Access Journals (Sweden)

    Cerrone Cabanos

    2017-08-01

    Full Text Available Lipid regulation of ion channels by low-abundance signaling lipids phosphatidylinositol 4,5-bisphosphate (PIP2 and phosphatidic acid (PA has emerged as a central cellular mechanism for controlling ion channels and the excitability of nerves. A lack of robust assays suitable for facile detection of a lipid bound to a channel has hampered the probing of the lipid binding sites and measuring the pharmacology of putative lipid agonists for ion channels. Here, we show a fluorescent PIP2 competition assay for detergent-purified potassium channels, including TWIK-1-related K+-channel (TREK-1. Anionic lipids PA and phosphatidylglycerol (PG bind dose dependently (9.1 and 96 μM, respectively and agonize the channel. Our assay shows PIP2 binds with high affinity (0.87 μM but surprisingly can directly antagonize TREK-1 in liposomes. We propose a model for TREK-1 lipid regulation where PIP2 can compete with PA and PG agonism based on the affinity of the lipid for a site within the channel.

  2. Equilibrium switching and mathematical properties of nonlinear interaction networks with concurrent antagonism and self-stimulation

    International Nuclear Information System (INIS)

    Rabajante, Jomar Fajardo; Talaue, Cherryl Ortega

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: •Properties of n-dimensional decision model of competitive interaction networks. •Graphical technique for component-wise and steady state stability analysis. •Search for parameter conditions that control equilibrium switching. •Illustrations of multi-stable systems and repressilators. -- Abstract: Concurrent decision-making model (CDM) of interaction networks with more than two antagonistic components represents various biological systems, such as gene interaction, species competition and mental cognition. The CDM model assumes sigmoid kinetics where every component stimulates itself but concurrently represses the others. Here we prove generic mathematical properties (e.g., location and stability of steady states) of n-dimensional CDM with either symmetric or asymmetric reciprocal antagonism between components. Significant modifications in parameter values serve as biological regulators for inducing steady state switching by driving a temporal state to escape an undesirable equilibrium. Increasing the maximal growth rate and decreasing the decay rate can expand the basin of attraction of a steady state that contains the desired dominant component. Perpetually adding an external stimulus could shut down multi-stability of the system which increases the robustness of the system against stochastic noise. We further show that asymmetric interaction forming a repressilator-type network generates oscillatory behavior

  3. Plant Essential Oils Synergize and Antagonize Toxicity of Different Conventional Insecticides against Myzus persicae (Hemiptera: Aphididae)

    Science.gov (United States)

    Faraone, Nicoletta; Hillier, N. Kirk; Cutler, G. Christopher

    2015-01-01

    Plant-derived products can play an important role in pest management programs. Essential oils from Lavandula angustifolia (lavender) and Thymus vulgaris (thyme) and their main constituents, linalool and thymol, respectively, were evaluated for insecticidal activity and synergistic action in combination with insecticides against green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). The essential oils and their main constituents exerted similar insecticidal activity when aphids were exposed by direct sprays, but were non-toxic by exposure to treated leaf discs. In synergism experiments, the toxicity of imidacloprid was synergized 16- to 20-fold by L. angustifolia and T. vulgaris essential oils, but far less synergism occurred with linalool and thymol, indicating that secondary constituents of the oils were probably responsible for the observed synergism. In contrast to results with imidacloprid, the insecticidal activity of spirotetramat was antagonized by L. angustifolia and T. vulgaris essential oils, and linalool and thymol. Our results demonstrate the potential of plant essential oils as synergists of insecticides, but show that antagonistic action against certain insecticides may occur. PMID:26010088

  4. Biological activity of the non-microbial fraction of kefir: antagonism against intestinal pathogens.

    Science.gov (United States)

    Iraporda, Carolina; Abatemarco Júnior, Mário; Neumann, Elisabeth; Nunes, Álvaro Cantini; Nicoli, Jacques R; Abraham, Analía G; Garrote, Graciela L

    2017-08-01

    Kefir is a fermented milk obtained by the activity of kefir grains which are composed of lactic and acetic acid bacteria, and yeasts. Many beneficial health effects have been associated with kefir consumption such as stimulation of the immune system and inhibition of pathogenic microorganisms. The biological activity of kefir may be attributed to the presence of a complex microbiota as well as the microbial metabolites that are released during fermentation. The aim of this work was to characterise the non-microbial fraction of kefir and to study its antagonism against Escherichia coli, Salmonella spp. and Bacillus cereus. During milk fermentation there was a production of organic acids, mainly lactic and acetic acid, with a consequent decrease in pH and lactose content. The non-microbial fraction of kefir added to nutrient broth at concentrations above 75% v/v induced a complete inhibition of pathogenic growth that could be ascribed to the presence of un-dissociated lactic acid. In vitro assays using an intestinal epithelial cell model indicated that pre-incubation of cells with the non-microbial fraction of kefir did not modify the association/invasion of Salmonella whereas pre-incubation of Salmonella with this fraction under conditions that did not affect their viability significantly decreased the pathogen's ability to invade epithelial cells. Lactate exerted a protective effect against Salmonella in a mouse model, demonstrating the relevance of metabolites present in the non-microbial fraction of kefir produced during milk fermentation.

  5. Glucocorticoid Antagonism Reduces Insulin Resistance and Associated Lipid Abnormalities in High-Fructose-Fed Mice.

    Science.gov (United States)

    Priyadarshini, Emayavaramban; Anuradha, Carani Venkatraman

    2017-02-01

    High intake of dietary fructose causes perturbation in lipid metabolism and provokes lipid-induced insulin resistance. A rise in glucocorticoids (GCs) has recently been suggested to be involved in fructose-induced insulin resistance. The objective of the study was to investigate the effect of GC blockade on lipid abnormalities in insulin-resistant mice. Insulin resistance was induced in mice by administering a high-fructose diet (HFrD) for 60 days. Mifepristone (RU486), a GC antagonist, was administered to HFrD-fed mice for the last 18 days, and the intracellular and extracellular GC levels, the glucocorticoid receptor (GR) activation and the expression of GC-regulated genes involved in lipid metabolism were examined. HFrD elevated the intracellular GC content in both liver and adipose tissue and enhanced the GR nuclear translocation. The plasma GC level remained unchanged. The levels of free fatty acids and triglycerides in plasma were elevated, accompanied by increased plasma insulin and glucose levels and decreased hepatic glycogen content. Treatment with RU486 reduced plasma lipid levels, tissue GC levels and the expression of GC-targeted genes involved in lipid accumulation, and it improved insulin sensitivity. This study demonstrated that HFrD-induced lipid accumulation and insulin resistance are mediated by enhanced GC in liver and adipose tissue and that GC antagonism might reduce fructose-induced lipid abnormalities and insulin resistance. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  6. Prolongevity medicine: Antagonic-Stress drug in distress, geriatrics, and related diseases. II. Clinical review--2003.

    Science.gov (United States)

    Riga, S; Riga, D; Schneider, F

    2004-06-01

    Distress and senescence, their reciprocal aggravating-quickening connections, and their related pathologies have a large worldwide impact on healthcare systems in this new millennium. For this reason, Antagonic-Stress (AS)--an advanced integrative therapy, with specific synergistic composition, and patented internationally--represents a significant strategy in health, aging, and longevity. Clinical research with AS proves the drug's efficacy in the management of distress (neurotic, stress-related, and affective disorders; behavioral syndromes associated with physiological disturbances and physical factors; mental and behavioral disorders due to psychoactive substance uses) and psychogeriatrics [organic, including symptomatic, mental disorders (OMD)]. Specific multiaxial psychopathological instruments and psychometric tests in multiple assessments used for gerontopsychiatry demonstrated strong improvements after AS administration in early-moderate stages of Alzheimer or vascular dementia, as well as in other OMD. In addition, comparative clinical studies evinced the superiority of AS (synergistic multitherapy) versus monotherapy [meclofenoxate (MF), piracetam (PA), pyritinol (PT), and nicergoline (NE), respectively]. These comparative clinical trials agreed closely with comparative preclinical research and confirmed AS synergistic homeostatic, adaptogenic, antioxidative, cerebrovascular, neurometabolic, and nootropic actions. Also, the AS protective actions against oxidative stress recommend this orthomolecular therapy in stress, aging, and free radical pathology.

  7. Innate immune restriction and antagonism of viral RNA lacking 2'-O methylation

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, Jennifer L. [Departments of Medicine, Washington University School of Medicine, St Louis., MO 63110 (United States); Diamond, Michael S., E-mail: diamond@borcim.wustl.edu [Departments of Medicine, Washington University School of Medicine, St Louis., MO 63110 (United States); Molecular Microbiology, Washington University School of Medicine, St Louis., MO 63110 (United States); Pathology & Immunology, Washington University School of Medicine, St Louis., MO 63110 (United States); The Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St Louis., MO 63110 (United States)

    2015-05-15

    N-7 and 2′-O methylation of host cell mRNA occurs in the nucleus and results in the generation of cap structures (cap 0, m{sup 7}GpppN; cap 1, m{sup 7}GpppNm) that control gene expression by modulating nuclear export, splicing, turnover, and protein synthesis. Remarkably, RNA cap modification also contributes to mammalian cell host defense as viral RNA lacking 2′-O methylation is sensed and inhibited by IFIT1, an interferon (IFN) stimulated gene (ISG). Accordingly, pathogenic viruses that replicate in the cytoplasm have evolved mechanisms to circumvent IFIT1 restriction and facilitate infection of mammalian cells. These include: (a) generating cap 1 structures on their RNA through cap-snatching or virally-encoded 2′-O methyltransferases, (b) using cap-independent means of translation, or (c) using RNA secondary structural motifs to antagonize IFIT1 binding. This review will discuss new insights as to how specific modifications at the 5′-end of viral RNA modulate host pathogen recognition responses to promote infection and disease.

  8. Endocannabinoid antagonism: blocking the excess in the treatment of high-risk abdominal obesity.

    Science.gov (United States)

    Duffy, Danielle; Rader, Daniel

    2007-02-01

    Abdominal obesity is a prevalent, worldwide problem linked to cardiometabolic comorbidities and an increased risk of coronary heart disease. First-line therapy to reduce such risk revolves around diet and exercise; however, such changes are often difficult to implement and unsuccessful. Understanding the underlying pathophysiology of underlying metabolic derangements could provide new targets for pharmacologic therapy. One system that has gained recent attention is the endocannabinoid system. The endocannabinoid system has a significant role in central appetite control and peripheral lipogenesis and is up-regulated in diet-induced obesity. Rimonabant is a selective cannabinoid-1 receptor antagonist and is the first compound of its type to test the hypothesis that down-regulating an overactive endocannabinoid system could have therapeutic benefit not only for weight loss but also for the atherogenic dyslipidemia and insulin resistance that cluster with abdominal obesity in particular. Animal models have been critical for elucidating the role of the endocannabinoid system in obesity and in demonstrating that antagonism with rimonabant can induce loss of visceral fat and improve insulin sensitivity. Early human trials with rimonabant have confirmed significant reductions in weight, as well as favorable changes in atherogenic dyslipidemia, insulin resistance, and markers of inflammation. Interestingly, some of these beneficial metabolic effects are partially weight-loss-independent, confirming the importance of peripheral endocannabinoid system effects in addition to central effects.

  9. How does the antagonism between capping and anti-capping proteins affect actin network dynamics?

    International Nuclear Information System (INIS)

    Hu Longhua; Papoian, Garegin A

    2011-01-01

    Actin-based cell motility is essential to many biological processes. We built a simplified, three-dimensional computational model and subsequently performed stochastic simulations to study the growth dynamics of lamellipodia-like branched networks. In this work, we shed light on the antagonism between capping and anti-capping proteins in regulating actin dynamics in the filamentous network. We discuss detailed mechanisms by which capping and anti-capping proteins affect the protrusion speed of the actin network and the rate of nucleation of filaments. We computed a phase diagram showing the regimes of motility enhancement and inhibition by these proteins. Our work shows that the effects of capping and anti-capping proteins are mainly transmitted by modulation of the filamentous network density and local availability of monomeric actin. We discovered that the combination of the capping/anti-capping regulatory network with nucleation-promoting proteins introduces robustness and redundancy in cell motility machinery, allowing the cell to easily achieve maximal protrusion speeds under a broader set of conditions. Finally, we discuss distributions of filament lengths under various conditions and speculate on their potential implication for the emergence of filopodia from the lamellipodial network.

  10. Repurposing Hsp104 to Antagonize Seminal Amyloid and Counter HIV Infection.

    Science.gov (United States)

    Castellano, Laura M; Bart, Stephen M; Holmes, Veronica M; Weissman, Drew; Shorter, James

    2015-08-20

    Naturally occurring proteolytic fragments of prostatic acid phosphatase (PAP248-286 and PAP85-120) and semenogelins (SEM1 and SEM2) form amyloid fibrils in seminal fluid, which capture HIV virions and promote infection. For example, PAP248-286 fibrils, termed SEVI (semen-derived enhancer of viral infection), can potentiate HIV infection by several orders of magnitude. Here, we design three disruptive technologies to rapidly antagonize seminal amyloid by repurposing Hsp104, an amyloid-remodeling nanomachine from yeast. First, Hsp104 and an enhanced engineered variant, Hsp104(A503V), directly remodel SEVI and PAP85-120 fibrils into non-amyloid forms. Second, we elucidate catalytically inactive Hsp104 scaffolds that do not remodel amyloid structure, but cluster SEVI, PAP85-120, and SEM1(45-107) fibrils into larger assemblies. Third, we modify Hsp104 to interact with the chambered protease ClpP, which enables coupled remodeling and degradation to irreversibly clear SEVI and PAP85-120 fibrils. Each strategy diminished the ability of seminal amyloid to promote HIV infection, and could have therapeutic utility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Androgen Receptor Antagonism By Divalent Ethisterone Conjugates In Castrate-Resistant Prostate Cancer Cells

    Science.gov (United States)

    Levine, Paul M.; Lee, Eugine; Greenfield, Alex; Bonneau, Richard; Logan, Susan K.; Garabedian, Michael J.; Kirshenbaum, Kent

    2013-01-01

    Sustained treatment of prostate cancer with Androgen Receptor (AR) antagonists can evoke drug resistance, leading to castrate-resistant disease. Elevated activity of the AR is often associated with this highly aggressive disease state. Therefore, new therapeutic regimens that target and modulate AR activity could prove beneficial. We previously introduced a versatile chemical platform to generate competitive and non-competitive multivalent peptoid oligomer conjugates that modulate AR activity. In particular, we identified a linear and a cyclic divalent ethisterone conjugate that exhibit potent anti-proliferative properties in LNCaP-abl cells, a model of castrate-resistant prostate cancer. Here, we characterize the mechanism of action of these compounds utilizing confocal microscopy, time-resolved fluorescence resonance energy transfer, chromatin immunoprecipitation, flow cytometry, and microarray analysis. The linear conjugate competitively blocks AR action by inhibiting DNA binding. In addition, the linear conjugate does not promote AR nuclear localization or co-activator binding. In contrast, the cyclic conjugate promotes AR nuclear localization and induces cell-cycle arrest, despite its inability to compete against endogenous ligand for binding to AR in vitro. Genome-wide expression analysis reveals that gene transcripts are differentially affected by treatment with the linear or cyclic conjugate. Although the divalent ethisterone conjugates share extensive chemical similarities, we illustrate that they can antagonize the AR via distinct mechanisms of action, establishing new therapeutic strategies for potential applications in AR pharmacology. PMID:22871957

  12. ANTAGONISM OF PROGESTERONE RECEPTOR SUPPRESSES CAROTID BODY RESPONSES TO HYPOXIA AND NICOTINE IN RAT PUPS

    Science.gov (United States)

    JOSEPH, V.; NIANE, L. M.; BAIRAM, A.

    2013-01-01

    We tested the hypothesis that antagonism of progesterone receptor (PR) in newborn rats alters carotid body and respiratory responses to hypoxia and nicotinic receptor agonists. Rats were treated with the PR antagonist mifepristone (daily oral gavage 40 μg/g/d) or vehicle between post-natal days 3 and 15. In 11–14-day-old rats, we used in vitro carotid body/carotid sinus nerve preparation and whole body plethysmography to assess the carotid body and ventilatory responses to hypoxia (65 mmHg in vitro, 10% O2 in vivo) and to nicotinic receptor agonists (as an excitatory modulator of carotid body activity—nicotine 100 μM for in vitro studies, and epibatidine 5 μg/kg, i.p., which mainly acts on peripheral nicotinic receptors, for in vivo studies). The carotid body responses to hypoxia and nicotine were drastically reduced by mifepristone. Compared with vehicle, mifepristone-treated rats had a reduced body weight. The ventilatory response to epibatidine was attenuated; however, the hypoxic ventilatory response was similar between vehicle and mifepristone-treated pups. Immunohistochemical staining revealed that mifepristone treatment did not change carotid body morphology. We conclude that PR activity is a critical factor ensuring proper carotid body function in newborn rats. PMID:22326965

  13. FoxO3A promotes metabolic adaptation to hypoxia by antagonizing Myc function

    DEFF Research Database (Denmark)

    Jensen, Kim Steen; Binderup, Tina; Jensen, Klaus Thorleif

    2011-01-01

    Exposure of metazoan organisms to hypoxia engages a metabolic switch orchestrated by the hypoxia-inducible factor 1 (HIF-1). HIF-1 mediates induction of glycolysis and active repression of mitochondrial respiration that reduces oxygen consumption and inhibits the production of potentially harmful...... tumour tissue in vivo and that FoxO3A short-hairpin RNA (shRNA)-expressing xenograft tumours are decreased in size and metabolically changed. Our findings define a novel mechanism by which FoxO3A promotes metabolic adaptation and stress resistance in hypoxia....... reactive oxygen species (ROS). Here, we show that FoxO3A is activated in hypoxia downstream of HIF-1 and mediates the hypoxic repression of a set of nuclear-encoded mitochondrial genes. FoxO3A is required for hypoxic suppression of mitochondrial mass, oxygen consumption, and ROS production and promotes...... cell survival in hypoxia. FoxO3A is recruited to the promoters of nuclear-encoded mitochondrial genes where it directly antagonizes c-Myc function via a mechanism that does not require binding to the consensus FoxO recognition element. Furthermore, we show that FoxO3A is activated in human hypoxic...

  14. Amyloid β-sheet mimics that antagonize protein aggregation and reduce amyloid toxicity

    Science.gov (United States)

    Cheng, Pin-Nan; Liu, Cong; Zhao, Minglei; Eisenberg, David; Nowick, James S.

    2012-11-01

    The amyloid protein aggregation associated with diseases such as Alzheimer's, Parkinson's and type II diabetes (among many others) features a bewildering variety of β-sheet-rich structures in transition from native proteins to ordered oligomers and fibres. The variation in the amino-acid sequences of the β-structures presents a challenge to developing a model system of β-sheets for the study of various amyloid aggregates. Here, we introduce a family of robust β-sheet macrocycles that can serve as a platform to display a variety of heptapeptide sequences from different amyloid proteins. We have tailored these amyloid β-sheet mimics (ABSMs) to antagonize the aggregation of various amyloid proteins, thereby reducing the toxicity of amyloid aggregates. We describe the structures and inhibitory properties of ABSMs containing amyloidogenic peptides from the amyloid-β peptide associated with Alzheimer's disease, β2-microglobulin associated with dialysis-related amyloidosis, α-synuclein associated with Parkinson's disease, islet amyloid polypeptide associated with type II diabetes, human and yeast prion proteins, and Tau, which forms neurofibrillary tangles.

  15. Glutathione and the Antioxidant Potential of Binary Mixtures with Flavonoids: Synergisms and Antagonisms

    Directory of Open Access Journals (Sweden)

    Patrícia Valentão

    2013-07-01

    Full Text Available Polyphenols are able to trap free radicals, which contributes to their known antioxidant capacity. In plant extracts, these secondary metabolites may act in concert, in a way that their combined activities will be superior to their individual effects (synergistic interaction. Several polyphenols have demonstrated clear antioxidant properties in vitro, and many of their biological actions have been attributed to their intrinsic reducing capabilities. As so, the intake of these compounds at certain concentrations in the diet and/or supplementation may potentiate the activity of reduced form glutathione (GSH, thus better fighting oxidative stress. The aim of this work was to predict a structure-antioxidant activity relationship using different classes of flavonoids and to assess, for the first time, possible synergisms and antagonisms with GSH. For these purposes a screening microassay involving the scavenging of DPPH• was applied. In general, among the tested compounds, those lacking the catechol group in B ring showed antagonistic behaviour with GSH. Myricetin displayed additive effect, while quercetin, fisetin, luteolin, luteolin-7-O-glucoside, taxifolin and (+-catechin demonstrated synergistic actions. Furthermore, adducts formed at C2′ and C5′ of the B ring seem to be more important for the antioxidant capacity than adducts formed at C6 and C8 of the A ring.

  16. Action of Bacopa monnieri to antagonize cisplatin-induced emesis in Suncus murinus (house musk shrew

    Directory of Open Access Journals (Sweden)

    Ihsan Ullah

    2017-04-01

    Full Text Available Bacopa monnieri (BM, family Scrophulariaceae is used in several traditional systems of medicine for the management of epilepsy, depression, neuropathic pain, sleep disorders and memory deficits. The present study investigated the potential of BM methanol (BM-MetFr and BM n-butanol fractions (BM-ButFr to reduce chemotherapy-induced emesis in Suncus murinus (house musk shrew. Cisplatin (30 mg/kg, i.p. reliably induced retching and/or vomiting over a 2 day period. BM-MetFr (10–40 mg/kg, s.c. and BM-ButFr (5–20 mg/kg, s.c. antagonized the retching and/or vomiting response by ∼59.4% (p  0.05. In conclusion, the n-butanol fractions of BM have anti-emetic activity comparable with palonosetron and MPG. BM may be useful alone or in combination with other anti-emetic drugs for the treatment of chemotherapy-induced emesis in man.

  17. Accumulation of the Vitamin D Precursor Cholecalciferol Antagonizes Hedgehog Signaling to Impair Hemogenic Endothelium Formation

    Directory of Open Access Journals (Sweden)

    Mauricio Cortes

    2015-10-01

    Full Text Available Hematopoietic stem and progenitor cells (HSPCs are born from hemogenic endothelium in the dorsal aorta. Specification of this hematopoietic niche is regulated by a signaling axis using Hedgehog (Hh and Notch, which culminates in expression of Runx1 in the ventral wall of the artery. Here, we demonstrate that the vitamin D precursor cholecalciferol (D3 modulates HSPC production by impairing hemogenic vascular niche formation. Accumulation of D3 through exogenous treatment or inhibition of Cyp2r1, the enzyme required for D3 25-hydroxylation, results in Hh pathway antagonism marked by loss of Gli-reporter activation, defects in vascular niche identity, and reduced HSPCs. Mechanistic studies indicated the effect was specific to D3, and not active 1,25-dihydroxy vitamin D3, acting on the extracellular sterol-binding domain of Smoothened. These findings highlight a direct impact of inefficient vitamin D synthesis on cell fate commitment and maturation in Hh-regulated tissues, which may have implications beyond hemogenic endothelium specification.

  18. Metformin Antagonizes Cancer Cell Proliferation by Suppressing Mitochondrial-Dependent Biosynthesis.

    Directory of Open Access Journals (Sweden)

    Takla Griss

    2015-12-01

    Full Text Available Metformin is a biguanide widely prescribed to treat Type II diabetes that has gained interest as an antineoplastic agent. Recent work suggests that metformin directly antagonizes cancer cell growth through its actions on complex I of the mitochondrial electron transport chain (ETC. However, the mechanisms by which metformin arrests cancer cell proliferation remain poorly defined. Here we demonstrate that the metabolic checkpoint kinases AMP-activated protein kinase (AMPK and LKB1 are not required for the antiproliferative effects of metformin. Rather, metformin inhibits cancer cell proliferation by suppressing mitochondrial-dependent biosynthetic activity. We show that in vitro metformin decreases the flow of glucose- and glutamine-derived metabolic intermediates into the Tricarboxylic Acid (TCA cycle, leading to reduced citrate production and de novo lipid biosynthesis. Tumor cells lacking functional mitochondria maintain lipid biosynthesis in the presence of metformin via glutamine-dependent reductive carboxylation, and display reduced sensitivity to metformin-induced proliferative arrest. Our data indicate that metformin inhibits cancer cell proliferation by suppressing the production of mitochondrial-dependent metabolic intermediates required for cell growth, and that metabolic adaptations that bypass mitochondrial-dependent biosynthesis may provide a mechanism of tumor cell resistance to biguanide activity.

  19. Antagonizing beta-amyloid peptide neurotoxicity of the anti-aging fungus Ganoderma lucidum.

    Science.gov (United States)

    Lai, Cora Sau-Wan; Yu, Man-Shan; Yuen, Wai-Hung; So, Kwok-Fai; Zee, Sze-Yong; Chang, Raymond Chuen-Chung

    2008-01-23

    Ganoderma lucidum (Leyss. ex Fr.) Karst. (Lingzhi) is a medicinal fungus used clinically in many Asian countries to promote health and longevity. Synaptic degeneration is another key mode of neurodegeneration in Alzheimer's disease (AD). Recent studies have shown the loss of synaptic density proteins in each individual neuron during the progression of AD. It was recently reported that beta-amyloid (Abeta) could cause synaptic dysfunction and contribute to AD pathology. In this study, we reported that aqueous extract of G. lucidum significantly attenuated Abeta-induced synaptotoxicity by preserving the synaptic density protein, synaptophysin. In addition, G. lucidum aqueous extract antagonized Abeta-triggered DEVD cleavage activities in a dose-dependent manner. Further studies elucidated that phosphorylation of c-Jun N-terminal kinase, c-Jun, and p38 MAP kinase was attenuated by G. lucidum in Abeta-stressed neurons. Taken together, the results prove a hypothesis that anti-aging G. lucidum can prevent harmful effects of the exterminating toxin Abeta in AD.

  20. Effect of blockage of the endocannabinoid system by CB(1) antagonism on cardiovascular risk.

    Science.gov (United States)

    Mach, François; Montecucco, Fabrizio; Steffens, Sabine

    2009-01-01

    The endocannabinoid system is a crucial player in the inflammatory processes underlying atherosclerosis. Recently, basic research studies and animal models have strongly supported the role of the endocannabinoid system not only in the regulation of classical cardiovascular risk factors (including lipid profile and glucose homeostasis), but also in the activation of immune cells and inflammatory mediators. Clinical trials investigating treatment with rimonabant (a selective antagonist of the cannabinoid type 1 receptor) have suggested a beneficial effect of this drug in the management of obesity. Further studies are needed to explore a possible use for rimonabant in treating type 2 diabetes and acute and chronic cardiovascular disease. Despite the slight increase in adverse events (mainly psychiatric), which has led to the recent withdrawal of rimonabant from the market, CB(1) receptor antagonism might represent a very promising therapeutic strategy to reduce the cardiovascular risk. In the present review, we focused on the most important experimental investigations into the role of the endocannabinoid system in atherosclerosis and cardiovascular risk.