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Sample records for vibrio fischeri previous

  1. Engineering Vibrio fischeri for Inducible Gene Expression.

    Science.gov (United States)

    Ondrey, Jakob M; Visick, Karen L

    2014-01-01

    The marine bacterium Vibrio fischeri serves as a model organism for a variety of natural phenomena, including symbiotic host colonization. The ease with which the V. fischeri genome can be manipulated contributes greatly to our ability to identify the factors involved in these phenomena. Here, we have adapted genetic tools for use in V. fischeri to promote our ability to conditionally control the expression of genes of interest. Specifically, we modified the commonly used mini-Tn5 transposon to contain an outward-facing, LacI-repressible/IPTG-inducible promoter, and inserted the lacI gene into the V. fischeri chromosome. Used together, these tools permit the identification and induction of genes that control specific phenotypes. To validate this approach, we identified IPTG-controllable motility mutants. We anticipate that the ability to randomly insert an inducible promoter into the genome of V. fischeri will advance our understanding of various aspects of the physiology of this microbe.

  2. Vibrio fischeri metabolism: symbiosis and beyond.

    Science.gov (United States)

    Dunn, Anne K

    2012-01-01

    Vibrio fischeri is a bioluminescent, Gram-negative marine bacterium that can be found free living and in a mutualistic association with certain squids and fishes. Over the past decades, the study of V. fischeri has led to important discoveries about bioluminescence, quorum sensing, and the mechanisms that underlie beneficial host-microbe interactions. This chapter highlights what has been learned about metabolic pathways in V. fischeri, and how this information contributes to a broader understanding of the role of bacterial metabolism in host colonization by both beneficial and pathogenic bacteria, as well as in the growth and survival of free-living bacteria. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. [Influence of aflatoxin on Vibrio fischeri luminescence].

    Science.gov (United States)

    Li, Xiang; Pan, Li; Wang, Bin

    2011-12-01

    In the present study, we aim to evaluate the inhibitory effect of aflatoxin on Vibrio fischeri luminescence. V. fischeri culture is treated with aflatoxin or the culture broth of aflatoxin-producing strains, and the luminescence intensity of V. fischeri is detected to analyze the influence of aflatoxin on V. fischeri. The logarithmic value of aflatoxin concentration and the decrease ratio of V. fischeri luminescence is in a linear relationship. Based on the regression equation between aflatoxin concentration and luminescence decrease of V. fischeri, the toxin-producing status of different microbes can be detected quickly and exactly: all of six tested Aspergillus flavus strains show toxigenicity to V. fischeri, and their toxin yield reached 14.94 mg/L - 46.45 mg/L (represented by aflatoxin concentration), while the tested Aspergillus oryzae shows no toxigenicity. The above data showed that the luminescence change of V. fischeri could exactly reflect the capability of various microbes to produce toxin (especially aflatoxin), which provided a new clue for rapid detection of aflatoxin in industrial and agricultural production and could be developed as a potential method for aflatoxin assay.

  4. Transformation Experiment Using Bioluminescence Genes of "Vibrio fischeri."

    Science.gov (United States)

    Slock, James

    1995-01-01

    Bioluminescence transformation experiments show students the excitement and power of recombinant DNA technology. This laboratory experiment utilizes two plasmids of "Vibrio fischeri" in a transformation experiment. (LZ)

  5. Arabinose induces pellicle formation by Vibrio fischeri.

    Science.gov (United States)

    Visick, Karen L; Quirke, Kevin P; McEwen, Sheila M

    2013-03-01

    Biofilms are multicellular communities of bacteria attached to a surface and embedded in a protective matrix. In many cases, the signals that induce biofilm formation are unknown. Here, we report that biofilm formation by the marine bacterium Vibrio fischeri can be induced by the addition of arabinose to LBS (Luria-Bertani-salt), a tryptone-based medium. Growth of cells in the presence of 0.2% arabinose, but not other sugars, induced the production of a pellicle at the air/liquid interfaces of static cultures. V. fischeri failed to grow on arabinose as the sole carbon source, suggesting that pellicle production did not occur as a result of increased growth, but experiments using the acid/base indicator phenol red suggested that V. fischeri may partially metabolize arabinose. Pellicle production was independent of the syp polysaccharide locus but was altered upon disruption of the bcs cellulose locus. Through a screen for mutants defective for pellicle production, we found that loss of motility disrupted the formation of the arabinose-induced pellicle. Among the ∼20 mutants that retained motility were strains with insertions in a putative msh pilus locus and a strain with a defect in yidK, which is involved in galactose catabolism. Mutants with the msh gene disrupted grew poorly in the presence of arabinose, while the yidK mutant appeared to be "blind" to the presence of arabinose. Finally, arabinose impaired symbiotic colonization by V. fischeri. This work thus identifies a novel signal and new pathways involved in control of biofilm formation by V. fischeri.

  6. Vibrio fischeri-derived outer membrane vesicles trigger host development.

    Science.gov (United States)

    Aschtgen, Marie-Stephanie; Wetzel, Keith; Goldman, William; McFall-Ngai, Margaret; Ruby, Edward

    2016-04-01

    Outer membrane vesicles (OMV) are critical elements in many host-cell/microbe interactions. Previous studies of the symbiotic association between Euprymna scolopes and Vibrio fischeri had shown that within 12 h of colonizing crypts deep within the squid's light organ, the symbionts trigger an irreversible programme of tissue development in the host. Here, we report that OMV produced by V. fischeri are powerful contributors to this process. The first detectable host response to the OMV is an increased trafficking of macrophage-like cells called haemocytes into surface epithelial tissues. We showed that exposing the squid to other Vibrio species fails to induce this trafficking; however, addition of a high concentration of their OMV, which can diffuse into the crypts, does. We also provide evidence that tracheal cytotoxin released by the symbionts, which can induce haemocyte trafficking, is not part of the OMV cargo, suggesting two distinct mechanisms to induce the same morphogenesis event. By manipulating the timing and localization of OMV signal delivery, we showed that haemocyte trafficking is fully induced only when V. fischeri, the sole species able to reach and grow in the crypts, succeeds in establishing a sustained colonization. Further, our data suggest that the host's detection of OMV serves as a symbiotic checkpoint prior to inducing irreversible morphogenesis. © 2015 John Wiley & Sons Ltd.

  7. O-antigen and Core Carbohydrate of Vibrio fischeri Lipopolysaccharide

    Science.gov (United States)

    Post, Deborah M. B.; Yu, Liping; Krasity, Benjamin C.; Choudhury, Biswa; Mandel, Mark J.; Brennan, Caitlin A.; Ruby, Edward G.; McFall-Ngai, Margaret J.; Gibson, Bradford W.; Apicella, Michael A.

    2012-01-01

    Vibrio fischeri exists in a symbiotic relationship with the Hawaiian bobtail squid, Euprymna scolopes, where the squid provides a home for the bacteria, and the bacteria in turn provide camouflage that helps protect the squid from night-time predators. Like other Gram-negative organisms, V. fischeri expresses lipopolysaccharide (LPS) on its cell surface. The structure of the O-antigen and the core components of the LPS and their possible role in colonization of the squid have not previously been determined. In these studies, an O-antigen ligase mutant, waaL, was utilized to determine the structures of these LPS components and their roles in colonization of the squid. WaaL ligates the O-antigen to the core of the LPS; thus, LPS from waaL mutants lacks O-antigen. Our results show that the V. fischeri waaL mutant has a motility defect, is significantly delayed in colonization, and is unable to compete with the wild-type strain in co-colonization assays. Comparative analyses of the LPS from the wild-type and waaL strains showed that the V. fischeri LPS has a single O-antigen repeat composed of yersiniose, 8-epi-legionaminic acid, and N-acetylfucosamine. In addition, the LPS from the waaL strain showed that the core structure consists of l-glycero-d-manno-heptose, d-glycero-d-manno-heptose, glucose, 3-deoxy-d-manno-octulosonic acid, N-acetylgalactosamine, 8-epi-legionaminic acid, phosphate, and phosphoethanolamine. These studies indicate that the unusual V. fischeri O-antigen sugars play a role in the early phases of bacterial colonization of the squid. PMID:22247546

  8. Role for cheR of Vibrio fischeri in the Vibrio-squid symbiosis.

    Science.gov (United States)

    Deloney-Marino, Cindy R; Visick, Karen L

    2012-01-01

    Upon hatching, the Hawaiian squid Euprymna scolopes is rapidly colonized by its symbiotic partner, the bioluminescent marine bacterium Vibrio fischeri . Vibrio fischeri cells present in the seawater enter the light organ of juvenile squid in a process that requires bacterial motility. In this study, we investigated the role chemotaxis may play in establishing this symbiotic colonization. Previously, we reported that V. fischeri migrates toward numerous attractants, including N-acetylneuraminic acid (NANA), a component of squid mucus. However, whether or not migration toward an attractant such as squid-derived NANA helps the bacterium to localize toward the light organ is unknown. When tested for the ability to colonize juvenile squid, a V. fischeri chemotaxis mutant defective for the methyltransferase CheR was outcompeted by the wild-type strain in co-inoculation experiments, even when the mutant was present in fourfold excess. Our results suggest that the ability to perform chemotaxis is an advantage during colonization, but not essential.

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

    Digital Repository Service at National Institute of Oceanography (India)

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

    Physical 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...

  10. Shedding light on bioluminescence regulation in Vibrio fischeri.

    Science.gov (United States)

    Miyashiro, Tim; Ruby, Edward G

    2012-06-01

    The bioluminescence emitted by the marine bacterium Vibrio fischeri is a particularly striking result of individual microbial cells co-ordinating a group behaviour. The genes responsible for light production are principally regulated by the LuxR-LuxI quorum-sensing system. In addition to LuxR-LuxI, numerous other genetic elements and environmental conditions control bioluminescence production. Efforts to mathematically model the LuxR-LuxI system are providing insight into the dynamics of this autoinduction behaviour. The Hawaiian squid Euprymna scolopes forms a natural symbiosis with V. fischeri, and utilizes the symbiont-derived bioluminescence for certain nocturnal behaviours, such as counterillumination. Recent work suggests that the tissue with which V. fischeri associates not only can detect bioluminescence but may also use this light to monitor the V. fischeri population. © 2012 Blackwell Publishing Ltd.

  11. Chemoreceptor VfcA mediates amino acid chemotaxis in Vibrio fischeri.

    Science.gov (United States)

    Brennan, Caitlin A; DeLoney-Marino, Cindy R; Mandel, Mark J

    2013-03-01

    Flagellar motility and chemotaxis by Vibrio fischeri are important behaviors mediating the colonization of its mutualistic host, the Hawaiian bobtail squid. However, none of the 43 putative methyl-accepting chemotaxis proteins (MCPs) encoded in the V. fischeri genome has been previously characterized. Using both an available transposon mutant collection and directed mutagenesis, we isolated mutants for 19 of these genes, and screened them for altered chemotaxis to six previously identified chemoattractants. Only one mutant was defective in responding to any of the tested compounds; the disrupted gene was thus named vfcA (Vibrio fischeri chemoreceptor A; locus tag VF_0777). In soft-agar plates, mutants disrupted in vfcA did not exhibit the serine-sensing chemotactic ring, and the pattern of migration in the mutant was not affected by the addition of exogenous serine. Using a capillary chemotaxis assay, we showed that, unlike wild-type V. fischeri, the vfcA mutant did not undergo chemotaxis toward serine and that expression of vfcA on a plasmid in the mutant was sufficient to restore the behavior. In addition to serine, we demonstrated that alanine, cysteine, and threonine are strong attractants for wild-type V. fischeri and that the attraction is also mediated by VfcA. This study thus provides the first insights into how V. fischeri integrates information from one of its 43 MCPs to respond to environmental stimuli.

  12. The Effect of Magnetic Fields on the Quorum Sensing-Regulated Luminescence of Vibrio fischeri

    Science.gov (United States)

    Barron, Addie; Hagen, Steve; Son, Minjun

    2015-03-01

    Quorum sensing (QS) is a mechanism by which bacteria communicate through the secretion and detection of extracellular signaling molecules known as autoinducers. This research focuses on the quorum sensing regulated bioluminescence of Vibrio fischeri, a marine bacterium that lives in symbiosis with certain fish and squid species. Previous studies of V. harveyi, a close relative of V. fisheri, indicate that a strong magnetic field has a positive effect on V.harveyi bioluminescence. However the effect of magnetic fields on quorum sensing-regulated luminescence is in general poorly understood. We grew V. fischeri in solid and liquid growth media, subject to strong static magnetic fields, and imaged the bioluminescence over a period of forty-eight hours. Luminescence patterns were analyzed in both the spatial and time dimensions. We find no indication that a magnetic field influences Vibrio fischeri luminescence either positively or negatively. This research was funded by the Grant Number NSF DMR-1156737.

  13. Photodynamic antimicrobial chemotherapy in aquaculture: photoinactivation studies of Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Eliana Alves

    Full Text Available BACKGROUND: Photodynamic antimicrobial chemotherapy (PACT combines light, a light-absorbing molecule that initiates a photochemical or photophysical reaction, and oxygen. The combined action of these three components originates reactive oxygen species that lead to microorganisms' destruction. The aim was to evaluate the efficiency of PACT on Vibrio fischeri: 1 with buffer solution, varying temperature, pH, salinity and oxygen concentration values; 2 with aquaculture water, to reproduce photoinactivation (PI conditions in situ. METHODOLOGY/PRINCIPAL FINDINGS: To monitor the PI kinetics, the bioluminescence of V. fischeri was measured during the experiments. A tricationic meso-substituted porphyrin (Tri-Py(+-Me-PF was used as photosensitizer (5 µM in the studies with buffer solution and 10-50 µM in the studies with aquaculture water; artificial white light (4 mW cm(-2 and solar irradiation (40 mW cm(-2 were used as light sources; and the bacterial concentration used for all experiments was ≈10(7 CFU mL(-1 (corresponding to a bioluminescence level of 10(5 relative light units--RLU. The variations in pH (6.5-8.5, temperature (10-25°C, salinity (20-40 g L(-1 and oxygen concentration did not significantly affect the PI of V. fischeri, once in all tested conditions the bioluminescent signal decreased to the detection limit of the method (≈7 log reduction. The assays using aquaculture water showed that the efficiency of the process is affected by the suspended matter. Total PI of V. fischeri in aquaculture water was achieved under solar light in the presence of 20 µM of Tri-Py(+-Me-PF. CONCLUSIONS/SIGNIFICANCE: If PACT is to be used in environmental applications, the matrix containing target microbial communities should be previously characterized in order to establish an efficient protocol having into account the photosensitizer concentration, the light source and the total light dose delivered. The possibility of using solar light in PACT to

  14. Predation response of Vibrio fischeri biofilms to bacterivorus protists.

    Science.gov (United States)

    Chavez-Dozal, Alba; Gorman, Clayton; Erken, Martina; Steinberg, Peter D; McDougald, Diane; Nishiguchi, Michele K

    2013-01-01

    Vibrio fischeri proliferates in a sessile, stable community known as a biofilm, which is one alternative survival strategy of its life cycle. Although this survival strategy provides adequate protection from abiotic factors, marine biofilms are still susceptible to grazing by bacteria-consuming protozoa. Subsequently, grazing pressure can be controlled by certain defense mechanisms that confer higher biofilm antipredator fitness. In the present work, we hypothesized that V. fischeri exhibits an antipredator fitness behavior while forming biofilms. Different predators representing commonly found species in aquatic populations were examined, including the flagellates Rhynchomonas nasuta and Neobodo designis (early biofilm feeders) and the ciliate Tetrahymena pyriformis (late biofilm grazer). V. fischeri biofilms included isolates from both seawater and squid hosts (Euprymna and Sepiola species). Our results demonstrate inhibition of predation by biofilms, specifically, isolates from seawater. Additionally, antiprotozoan behavior was observed to be higher in late biofilms, particularly toward the ciliate T. pyriformis; however, inhibitory effects were found to be widespread among all isolates tested. These results provide an alternative explanation for the adaptive advantage and persistence of V. fischeri biofilms and provide an important contribution to the understanding of defensive mechanisms that exist in the out-of-host environment.

  15. Dominance of Vibrio fischeri in secreted mucus outside the light organ of Euprymna scolopes: the first site of symbiont specificity.

    Science.gov (United States)

    Nyholm, Spencer V; McFall-Ngai, Margaret J

    2003-07-01

    Previous studies of the Euprymna scolopes-Vibrio fischeri symbiosis have demonstrated that, during colonization, the hatchling host secretes mucus in which gram-negative environmental bacteria amass in dense aggregations outside the sites of infection. In this study, experiments with green fluorescent protein-labeled symbiotic and nonsymbiotic species of gram-negative bacteria were used to characterize the behavior of cells in the aggregates. When hatchling animals were exposed to 10(3) to 10(6) V. fischeri cells/ml added to natural seawater, which contains a mix of approximately 10(6) nonspecific bacterial cells/ml, V. fischeri cells were the principal bacterial cells present in the aggregations. Furthermore, when animals were exposed to equal cell numbers of V. fischeri (either a motile or a nonmotile strain) and either Vibrio parahaemolyticus or Photobacterium leiognathi, phylogenetically related gram-negative bacteria that also occur in the host's habitat, the symbiont cells were dominant in the aggregations. The presence of V. fischeri did not compromise the viability of these other species in the aggregations, and no significant growth of V. fischeri cells was detected. These findings suggested that dominance results from the ability of V. fischeri either to accumulate or to be retained more effectively within the mucus. Viability of the V. fischeri cells was required for both the formation of tight aggregates and their dominance in the mucus. Neither of the V. fischeri quorum-sensing compounds accumulated in the aggregations, which suggested that the effects of these small signal molecules are not critical to V. fischeri dominance. Taken together, these data provide evidence that the specificity of the squid-vibrio symbiosis begins early in the interaction, in the mucus where the symbionts aggregate outside of the light organ.

  16. Vibrio fischeri flavohaemoglobin protects against nitric oxide during initiation of the squid-Vibrio symbiosis.

    Science.gov (United States)

    Wang, Yanling; Dunn, Anne K; Wilneff, Jacqueline; McFall-Ngai, Margaret J; Spiro, Stephen; Ruby, Edward G

    2010-11-01

    Nitric oxide (NO) is implicated in a wide range of biological processes, including innate immunity against pathogens, signal transduction and protection against oxidative stress. However, its possible roles in beneficial host-microbe associations are less well recognized. During the early stages of the squid-vibrio symbiosis, the bacterial symbiont Vibrio fischeri encounters host-derived NO, which has been hypothesized to serve as a specificity determinant. We demonstrate here that the flavohaemoglobin, Hmp, of V. fischeri protects against NO, both in culture and during colonization of the squid host. Transcriptional analyses indicate that hmp expression is highly responsive to NO, principally through the repressor, NsrR. Hmp protects V. fischeri from NO inhibition of aerobic respiration, and removes NO under both oxic and anoxic conditions. A Δhmp mutant of V. fischeri initiates squid colonization less effectively than wild type, but is rescued by the presence of an NO synthase inhibitor. The hmp promoter is activated during the initial stage of colonization, during which the Δhmp strain fails to form normal-sized aggregates of colonizing cells. Taken together, these results suggest that the sensing of host-derived NO by NsrR, and the subsequent removal of NO by Hmp, influence aggregate size and, thereby, V. fischeri colonization efficiency. © 2010 Blackwell Publishing Ltd.

  17. Transcriptional characterization of Vibrio fischeri during colonization of juvenile Euprymna scolopes.

    Science.gov (United States)

    Thompson, Luke R; Nikolakakis, Kiel; Pan, Shu; Reed, Jennifer; Knight, Rob; Ruby, Edward G

    2017-05-01

    The marine bacterium Vibrio fischeri is the monospecific symbiont of the Hawaiian bobtail squid, Euprymna scolopes, and the establishment of this association involves a number of signaling pathways and transcriptional responses between both partners. We report here the first full RNA-Seq dataset representing host-associated V. fischeri cells from colonized juvenile E. scolopes, as well as comparative transcriptomes under both laboratory and simulated marine planktonic conditions. These data elucidate the broad transcriptional changes that these bacteria undergo during the early stages of symbiotic colonization. We report several previously undescribed and unexpected transcriptional responses within the early stages of this symbiosis, including gene expression patterns consistent with biochemical stresses inside the host, and metabolic patterns distinct from those reported in associations with adult animals. Integration of these transcriptional data with a recently developed metabolic model of V. fischeri provides us with a clearer picture of the metabolic state of symbionts within the juvenile host, including their possible carbon sources. Taken together, these results expand our understanding of the early stages of the squid-vibrio symbiosis, and more generally inform the transcriptional responses underlying the activities of marine microbes during host colonization. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Complete Genome Sequence of Vibrio fischeri: A Symbiotic Bacterium with Pathogenic Congeners

    National Research Council Canada - National Science Library

    E. G. Ruby; M. Urbanowski; J. Campbell; A. Dunn; M. Faini; R. Gunsalus; P. Lostroh; C. Lupp; J. McCann; D. Millikan; A. Schaefer; E. Stabb; A. Stevens; K. Visick; C. Whistler; E. P. Greenberg

    2005-01-01

    Vibrio fischeri belongs to the Vibrionaceae, a large family of marine γ-proteobacteria that includes several dozen species known to engage in a diversity of beneficial or pathogenic interactions with animal tissue...

  19. Global discovery of colonization determinants in the squid symbiont Vibrio fischeri

    National Research Council Canada - National Science Library

    John F. Brooks; Mattias C. Gyllborg; David C. Cronin; Sarah J. Quillin; Celeste A. Mallama; Randi Foxall; Cheryl Whistler; Andrew L. Goodman; Mark J. Mandel

    2014-01-01

    .... To understand the molecular determinants of microbiota selection, we examined colonization of a simplified model in which the light organ of Euprymna scolopes squid is colonized exclusively by Vibrio fischeri bacteria...

  20. The light organ symbiont Vibrio fischeri possesses a homolog of the Vibrio cholerae transmembrane transcriptional activator ToxR.

    OpenAIRE

    Reich, K A; Schoolnik, G K

    1994-01-01

    A cross-hybridizing DNA fragment to Vibrio cholerae toxR was cloned from the nonpathogenic light organ symbiont Vibrio fischeri, and three proteins homologous to V. cholerae ToxR, ToxS, and HtpG were deduced from its DNA sequence. V. fischeri ToxR was found to activate a V. cholerae ToxR-regulated promoter, and an antiserum raised against the amino-terminal domain of V. cholerae ToxR cross-reacts V. fischeri ToxR.

  1. Vibrio fischeri σ54 Controls Motility, Biofilm Formation, Luminescence, and Colonization

    OpenAIRE

    Wolfe, Alan J.; Millikan, Deborah S.; Campbell, Joy M.; Visick, Karen L.

    2004-01-01

    In this study, we demonstrated that the putative Vibrio fischeri rpoN gene, which encodes σ54, controls flagellar biogenesis, biofilm development, and bioluminescence. We also show that rpoN plays a requisite role initiating the symbiotic association of V. fischeri with juveniles of the squid Euprymna scolopes.

  2. Regulation of lux Genes in Vibrio fischeri: Control of Symbiosis-Related Gene Expression System in a Marine Bacterium

    Science.gov (United States)

    1989-11-04

    RR04106 411d019 11 TITLE (Include Security Classification) U. Regulation of lux Genes in Vibrio fischeri : Control of a Symbiosis-Related Gene Expression...communication - - 19 ABSTRACT (Continue on reverse if necessary and identify by block number) The lux genes of Vibrio fischeri encode the ability of this...Regulation of lux Genes in Vibrio fischeri : Control of a Symbiosis-related Gene Expression System in a Marine Bacterium START DATE: 15 August 1988

  3. Reclassification of Vibrio fischeri, Vibrio logei, Vibrio salmonicida and Vibrio wodanis as Aliivibrio fischeri gen. nov., comb. nov., Aliivibrio logei comb. nov., Aliivibrio salmonicida comb. nov. and Aliivibrio wodanis comb. nov.

    Science.gov (United States)

    Urbanczyk, Henryk; Ast, Jennifer C; Higgins, Melissa J; Carson, Jeremy; Dunlap, Paul V

    2007-12-01

    Four closely related species, Vibrio fischeri, Vibrio logei, Vibrio salmonicida and Vibrio wodanis, form a clade within the family Vibrionaceae; the taxonomic status and phylogenetic position of this clade have remained ambiguous for many years. To resolve this ambiguity, we tested these species against other species of the Vibrionaceae for phylogenetic and phenotypic differences. Sequence identities for the 16S rRNA gene were > or =97.4 % among members of the V. fischeri group, but were Vibrio, with which they overlap in G+C content, and Enterovibrio, Grimontia and Salinivibrio, with which they do not overlap in G+C content). Combined analysis of the recA, rpoA, pyrH, gyrB and 16S rRNA gene sequences revealed that the species of the V. fischeri group form a tightly clustered clade, distinct from these other genera. Furthermore, phenotypic traits differentiated the V. fischeri group from other genera of the Vibrionaceae, and a panel of 13 biochemical tests discriminated members of the V. fischeri group from type strains of Photobacterium and Vibrio. These results indicate that the four species of the V. fischeri group represent a lineage within the Vibrionaceae that is distinct from other genera. We therefore propose their reclassification in a new genus, Aliivibrio gen. nov. Aliivibrio is composed of four species: Aliivibrio fischeri comb. nov. (the type species) (type strain ATCC 7744(T) =CAIM 329(T) =CCUG 13450(T) =CIP 103206(T) =DSM 507(T) =LMG 4414(T) =NCIMB 1281(T)), Aliivibrio logei comb. nov. (type strain ATCC 29985(T) =CCUG 20283(T) =CIP 104991(T) =NCIMB 2252(T)), Aliivibrio salmonicida comb. nov. (type strain ATCC 43839(T) =CIP 103166(T) =LMG 14010(T) =NCIMB 2262(T)) and Aliivibrio wodanis comb. nov. (type strain ATCC BAA-104(T) =NCIMB 13582(T) =LMG 24053(T)).

  4. Coordination of the arc regulatory system and pheromone-mediated positive feedback in controlling the Vibrio fischeri lux operon

    National Research Council Canada - National Science Library

    Septer, Alecia N; Stabb, Eric V

    2012-01-01

    .... We have explored the interplay between an environmentally responsive regulator and pheromone-mediated positive feedback in intercellular signaling by Vibrio fischeri ES114, a bioluminescent bacterium...

  5. Toxicity of individual naphthenic acids to Vibrio fischeri.

    Science.gov (United States)

    Jones, David; Scarlett, Alan G; West, Charles E; Rowland, Steven J

    2011-11-15

    Numerous studies have suggested that the toxicity of organic compounds containing at least one carboxylic acid group and broadly classified as "naphthenic acids", is of environmental concern. For example, the acute toxicity of the more than 1 billion m(3) of oil sands process-affected water and the hormonal activity of some offshore produced waters has been attributed to the acids. However, experimental evidence for the toxicity of the individual acids causing these effects has not been very forthcoming. Instead, most data have been gathered from assays of incompletely characterized extracts of the water, which may contain other toxic constituents. An alternative approach is to assay the individual identified toxicants. Since numerous petroleum-derived naphthenic acids and some in oil sands process water, have recently been identified, we were able to measure the toxicity of some individual acids to the bioluminescent bacterium, Vibrio fischeri. Thirty-five pure individual acids were either synthesized or purchased for this purpose. We also used the US EPA ECOSAR computer model to predict the toxicity of each acid to the water flea, Daphnia magna. Both are well-accepted toxicological screening end points. The results show how toxic some of the naphthenic acids really are (e.g., V. fischeri Effective Concentrations for 50% response (EC(50)) 0.004 to 0.7 mM) and reveal the influence of hydrophobicity and aqueous solubility on the toxicities. Comparison with measured toxicities of other known, but more minor, constituents of oil sands process water, such as polycyclic aromatic hydrocarbons and alkylphenols, helps place these toxicities into a wider context. Given the reported toxicological effects of naphthenic acids to other organisms (e.g., fish, plants), the toxicities of the acids to further end points should now be determined.

  6. Interactions between bicarbonate, potassium, and magnesium, and sulfur-dependent induction of luminescence in Vibrio fischeri.

    Science.gov (United States)

    Tabei, Yosuke; Era, Mariko; Ogawa, Akane; Morita, Hiroshi

    2012-06-01

    In spite of its central importance in research efforts, the relationship between seawater compounds and bacterial luminescence has not previously been investigated in detail. Thus, in this study, we investigated the effect of cations (Na(+) , K(+) , NH(4) (+) , Mg(2+) , and Ca(2+) ) and anions (Cl(-) , HCO(3) (-) , CO(3) (2-) , and NO(3) (-) ) on the induction of both inorganic (sulfate, sulfite, and thiosulfate) and organic (L-cysteine and L-cystine) sulfur-dependent luminescence in Vibrio fischeri. We found that HCO(3) (-) (bicarbonate) and CO(3) (2-) (carbonate), in the form of various compounds, had a stimulatory effect on sulfur-dependent luminescence. The luminescence induced by bicarbonate was further promoted by the addition of magnesium. Potassium also increased sulfur-dependent luminescence when sulfate or thiosulfate was supplied as the sole sulfur source, but not when sulfite, L-cysteine, or L-cystine was supplied. The positive effect of potassium was accelerated by the addition of magnesium and/or calcium. Furthermore, the additional supply of magnesium improved the induction of sulfite- or L-cysteine-dependent luminescence, but not the l-cystine-dependent type. These results suggest that sulfur-dependent luminescence of V. fischeri under nutrient-starved conditions is mainly controlled by bicarbonate, carbonate, and potassium. In addition, our results indicate that an additional supply of magnesium is effective for increasing V. fischeri luminescence. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Cellulose effects on morphology and elasticity of Vibrio fischeri biofilms.

    Science.gov (United States)

    Ziemba, Christopher; Shabtai, Yael; Piatkovsky, Maria; Herzberg, Moshe

    2016-01-01

    Cellulose effects on Vibrio fischeri biofilm morphology were tested for the wild-type and two of its isogenic mutants that either exhibit increased cellulose production or do not produce cellulose at all. Confocal laser scanning microscopy imaging of each biofilm revealed that total sessile volume increases with cellulose expression, but the size of colonies formed with cellulose was smaller, creating a more diffuse biofilm. These morphological differences were not attributed to variations in bacterial deposition, extracellular polymeric substances affinity to the surface or bacterial growth. A positive correlation was found between cellulose expression, Young's (elastic) modulus of the biofilm analyzed with atomic force microscope and shear modulus of the related extracellular polymeric substances layers analyzed with quartz crystal microbalance with dissipation monitoring. Cellulose production also correlated positively with concentrations of extracellular DNA. A significant negative correlation was observed between cellulose expression and rates of diffusion through the extracellular polymeric substances. The difference observed in biofilm morphology is suggested as a combined result of cellulose and likely extracellular DNA (i) increasing biofilm Young's modulus, making shear removal more difficult, and (ii) decreased diffusion rate of nutrients and wastes into and out of the biofilm, which effectively limits colony size.

  8. Directed evolution of Vibrio fischeri LuxR signal sensitivity.

    Science.gov (United States)

    Kimura, Yuki; Tashiro, Yohei; Saito, Kyoichi; Kawai-Noma, Shigeko; Umeno, Daisuke

    2016-11-01

    LuxR is the core component of Vibrio fischeri quorum sensing. It acts as the transcriptional activator by binding to its cognate signaling molecules 3-oxo-hexanoyl-homoserine lactone (3OC6HSL). Although several acyl-HSLs with 3-oxo groups are known to activate LuxR with similar efficiency, acyl-HSLs without 3-oxo groups are very weak inducers. We conducted a round of LuxR directed evolution to acquire LuxR mutants with higher signal sensitivity to octanoyl-homoserine lactone (C8HSL). All of the isolated mutants showed increased signal sensitivity to many other acyl-HSLs, including C8HSL, and some to the LuxR antagonist p-coumaroyl-HSL. The evolution of their ligand sensitivity proceeded through the stabilization of the signal-bound state, thereby elevating the effective concentration of LuxR at the ON-state. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Phylogeny and fitness of Vibrio fischeri from the light organs of Euprymna scolopes in two Oahu, Hawaii populations.

    Science.gov (United States)

    Wollenberg, Michael S; Ruby, Edward G

    2012-02-01

    The evolutionary relationship among Vibrio fischeri isolates obtained from the light organs of Euprymna scolopes collected around Oahu, Hawaii, were examined in this study. Phylogenetic reconstructions based on a concatenation of fragments of four housekeeping loci (recA, mdh, katA, pyrC) identified one monophyletic group ('Group-A') of V. fischeri from Oahu. Group-A V. fischeri strains could also be identified by a single DNA fingerprint type. V. fischeri strains with this fingerprint type had been observed to be at a significantly higher abundance than other strains in the light organs of adult squid collected from Maunalua Bay, Oahu, in 2005. We hypothesized that these previous observations might be related to a growth/survival advantage of the Group-A strains in the Maunalua Bay environments. Competition experiments between Group-A strains and non-Group-A strains demonstrated an advantage of the former in colonizing juvenile Maunalua Bay hosts. Growth and survival assays in Maunalua Bay seawater microcosms revealed a reduced fitness of Group-A strains relative to non-Group-A strains. From these results, we hypothesize that there may exist trade-offs between growth in the light organ and in seawater environments for local V. fischeri strains from Oahu. Alternatively, Group-A V. fischeri may represent an example of rapid, evolutionarily significant, specialization of a horizontally transmitted symbiont to a local host population.

  10. Vibrio fischeri LuxS and AinS: comparative study of two signal synthases.

    Science.gov (United States)

    Lupp, Claudia; Ruby, Edward G

    2004-06-01

    Vibrio fischeri possesses two acyl-homoserine lactone quorum-sensing systems, ain and lux, both of which are involved in the regulation of luminescence gene expression and are required for persistent colonization of the squid host, Euprymna scolopes. We have previously demonstrated that the ain system induces luminescence at cell densities that precede lux system activation. Our data suggested that the ain system both relieves repression and initially induces the lux system, thereby achieving sequential induction of gene expression by these two systems. Analysis of the V. fischeri genome revealed the presence of a putative third system based on the enzyme LuxS, which catalyzes the synthesis of the Vibrio harveyi autoinducer 2 (AI-2). In this study, we investigated the impact of V. fischeri LuxS on luminescence and colonization competence in comparison to that of the ain system. Similar to the ain system, inactivation of the AI-2 system decreased light production in culture, but not in the squid host. However, while an ainS mutant produces no detectable light in culture, a luxS mutant expressed approximately 70% of wild-type luminescence levels. A mutation in luxS alone did not compromise symbiotic competence of V. fischeri; however, levels of colonization of an ainS luxS double mutant were reduced to 50% of the already diminished level of ainS mutant colonization, suggesting that these two systems regulate colonization gene expression synergistically through a common pathway. Introduction of a luxO mutation into the luxS and ainS luxS background could relieve both luminescence and colonization defects, consistent with a model in which LuxS, like AinS, regulates gene expression through LuxO. Furthermore, while luxS transcription appeared to be constitutive and the AI-2 signal concentration did not change dramatically, our data suggest that ainS transcription is autoregulated, resulting in an over 2,000-fold increase in signal concentration as culture density

  11. Comparison of organics and heavy metals acute toxicities to Vibrio fischeri

    Directory of Open Access Journals (Sweden)

    Yang Xuepeng

    2016-01-01

    Full Text Available Vibrio fischeri bioluminescence inhibition has been widely used to test acute toxicities of metals and organics contaminants. However, the differences of metals and organics acute toxicities to V. fischeri have not been compared. Here, four heavy metals (Zn2+, Cu2+, Cd2+, Cr6+ and five organics (phenol, benzoic acid, p-hydroxy benzoic acid, nitro-benzene and benzene acute toxicities to V. fischeri were investigated. Heavy metals toxicities to V. fischeri were increased along with the reaction time, while the organics toxicities kept the same level in different reaction times. In order to explain the difference, the relative cell death rate of V. fischeri was detected. In metals toxicities tests, the bioluminescence inhibition rate of V. fischeri was found to be significantly higher than the relative cell death rate (P<0.05, while for the organics toxicities tests, the cell death rate was similar to the bioluminescence inhibition rate. These results indicated that organics acute toxicities to V. fischeri could reflect the death of cell, but metals acute toxicities to V. fischeri may not lead to the death of cell, just represent the bioluminescence inhibition.

  12. Measurement and analysis of Vibrio fischeri cell-based microfluidic device for personal health monitoring.

    Science.gov (United States)

    Zhao, Xinyan; Dong, Tao

    2013-01-01

    The cell-based microfluidic chip was designed and fabricated as a low-cost detector to continuously monitor toxicants in drinking water or human urine samples, which is expected to be an important component of a household health monitoring system in the future. The bioluminescent bacterium, Vibrio Fischeri, was selected to validate the function of device. Water samples and Vibrio fischeri cells were mixed and encapsulated into droplets in air flow, which can guarantee sufficient oxygen supply for cells in droplets. Preliminary tests were performed using copper ion (Cu(2+)) as the model toxicant. The droplet system was measured and analyzed at various flow rates in different observation chambers. Both deionized water and human urine samples were tested in the cell-based device. Interestingly, a strong relation between the R.L.U. (Relative Luminescence Units) in the observation chamber and the minute concentration of toxicant (Cu(2+)) was found using deionized water as solvent, whereas the relation was insignificant using human urine as solvent. This study showed the Vibrio fischeri cell-based device might be reliably employed as an early-warning system for the safety of drinking water. However, Vibrio fischeri is not competent to detect dangerous materials in a complex biofluid. With the replacement of cell sensors, the microfluidic device might be functional to analyze urine samples in theory.

  13. Substrate specificity and function of the pheromone receptor AinR in Vibrio fischeri ES114.

    Science.gov (United States)

    Kimbrough, John H; Stabb, Eric V

    2013-11-01

    Two distinct but interrelated pheromone-signaling systems, LuxI/LuxR and AinS/AinR, positively control bioluminescence in Vibrio fischeri. Although each system generates an acyl-homoserine lactone (AHL) signal, the protein sequences of LuxI/LuxR and AinS/AinR are unrelated. AinS and LuxI generate the pheromones N-octanoyl-AHL (C8-AHL) and N-3-oxo-hexanoyl-AHL (3OC6-AHL), respectively. LuxR is a transcriptional activator that responds to 3OC6-AHL, and to a lesser extent to C8-AHL. AinR is hypothesized to respond to C8-AHL and, based on homology to Vibrio harveyi LuxN, to mediate the repression of a Qrr regulatory RNA. However, a ΔainR mutation decreased luminescence, which was not predicted based on V. harveyi LuxN, raising the possibility of a distinct regulatory mechanism for AinR. Here we show that ainR can complement a luxN mutant, suggesting functional similarity. Moreover, in V. fischeri, we observed ainR-dependent repression of a Pqrr-lacZ transcriptional reporter in the presence of C8-AHL, consistent with its hypothesized regulatory role. The system appears quite sensitive, with a half-maximal effect on a Pqrr reporter at 140 pM C8-AHL. Several other AHLs with substituted and unsubstituted acyl chains between 6 and 10 carbons also displayed an AinR-dependent effect on Pqrr-lacZ; however, AHLs with acyl chains of four carbons or 12 or more carbons lacked activity. Interestingly, 3OC6-AHL also affected expression from the qrr promoter, but this effect was largely luxR dependent, indicating a previously unknown connection between these systems. Finally, we propose a preliminary explanation for the unexpected luminescence phenotype of the ΔainR mutant.

  14. Natural transformation of Vibrio fischeri requires tfoX and tfoY

    Science.gov (United States)

    Pollack-Berti, Amber; Wollenberg, Michael S.

    2010-01-01

    SUMMARY Recent evidence has indicated that natural genetic transformation occurs in Vibrio cholerae, and that it requires both induction by chitin oligosaccharides, like chitohexaose, and expression of a putative regulatory gene designated tfoX. Using sequence and phylogenetic analyses we have found two tfoX paralogues in all sequenced genomes of the genus Vibrio. Like V. cholerae, when grown in chitohexaose, cells of V. fischeri are able to take up and incorporate exogenous DNA. Chitohexaose-independent transformation by V. fischeri was observed when tfoX was present in multi-copy. The second tfoX paralogue, designated tfoY, is also required for efficient transformation in V. fischeri, but is not functionally identical to tfoX. Natural transformation of V. fischeri facilitates rapid transfer of mutations across strains, and provides a highly useful tool for experimental genetic manipulation in this species. The presence of chitin-induced competence in several vibrios highlights the potential for a conserved mechanism of genetic exchange across this family of environmentally important marine bacteria. PMID:21966921

  15. Gimme shelter: how Vibrio fischeri successfully navigates an animal’s multiple environments

    Science.gov (United States)

    Norsworthy, Allison N.; Visick, Karen L.

    2013-01-01

    Bacteria successfully colonize distinct niches because they can sense and appropriately respond to a variety of environmental signals. Of particular interest is how a bacterium negotiates the multiple, complex environments posed during successful infection of an animal host. One tractable model system to study how a bacterium manages a host’s multiple environments is the symbiotic relationship between the marine bacterium, Vibrio fischeri, and its squid host, Euprymna scolopes. V. fischeri encounters many different host surroundings ranging from initial contact with the squid to ultimate colonization of a specialized organ known as the light organ. For example, upon recognition of the squid, V. fischeri forms a biofilm aggregate outside the light organ that is required for efficient colonization. The bacteria then disperse from this biofilm to enter the organ, where they are exposed to nitric oxide, a molecule that can act as both a signal and an antimicrobial. After successfully managing this potentially hostile environment, V. fischeri cells finally establish their niche in the deep crypts of the light organ where the bacteria bioluminesce in a pheromone-dependent fashion, a phenotype that E. scolopes utilizes for anti-predation purposes. The mechanism by which V. fischeri manages these environments to outcompete all other bacterial species for colonization of E. scolopes is an important and intriguing question that will permit valuable insights into how a bacterium successfully associates with a host. This review focuses on specific molecular pathways that allow V. fischeri to establish this exquisite bacteria–host interaction. PMID:24348467

  16. Gimme shelter: how Vibrio fischeri successfully navigates an animal's multiple environments.

    Science.gov (United States)

    Norsworthy, Allison N; Visick, Karen L

    2013-01-01

    Bacteria successfully colonize distinct niches because they can sense and appropriately respond to a variety of environmental signals. Of particular interest is how a bacterium negotiates the multiple, complex environments posed during successful infection of an animal host. One tractable model system to study how a bacterium manages a host's multiple environments is the symbiotic relationship between the marine bacterium, Vibrio fischeri, and its squid host, Euprymna scolopes. V. fischeri encounters many different host surroundings ranging from initial contact with the squid to ultimate colonization of a specialized organ known as the light organ. For example, upon recognition of the squid, V. fischeri forms a biofilm aggregate outside the light organ that is required for efficient colonization. The bacteria then disperse from this biofilm to enter the organ, where they are exposed to nitric oxide, a molecule that can act as both a signal and an antimicrobial. After successfully managing this potentially hostile environment, V. fischeri cells finally establish their niche in the deep crypts of the light organ where the bacteria bioluminesce in a pheromone-dependent fashion, a phenotype that E. scolopes utilizes for anti-predation purposes. The mechanism by which V. fischeri manages these environments to outcompete all other bacterial species for colonization of E. scolopes is an important and intriguing question that will permit valuable insights into how a bacterium successfully associates with a host. This review focuses on specific molecular pathways that allow V. fischeri to establish this exquisite bacteria-host interaction.

  17. Gimme shelter: how Vibrio fischeri successfully navigates an animal’s multiple environments

    Directory of Open Access Journals (Sweden)

    Allison N Norsworthy

    2013-11-01

    Full Text Available Bacteria successfully colonize distinct niches because they can sense and appropriately respond to a variety of environmental signals. Of particular interest is how a bacterium negotiates the multiple, complex environments posed during successful infection of an animal host. One tractable model system to study how a bacterium manages a host’s multiple environments is the symbiotic relationship between the marine bacterium, Vibrio fischeri, and its squid host, Euprymna scolopes. V. fischeri encounters many different host surroundings ranging from initial contact with the squid to ultimate colonization of a specialized organ known as the light organ. For example, upon recognition of the squid, V. fischeri forms a biofilm aggregate outside the light organ that is required for efficient colonization. The bacteria then disperse from this biofilm to enter the organ, where they are exposed to nitric oxide, a molecule that can act as both a signal and an antimicrobial. After successfully managing this potentially hostile environment, V. fischeri finally establish their niche in the deep crypts of the light organ where the bacteria bioluminesce in a pheromone-dependent fashion, a phenotype that E. scolopes utilizes for anti-predation purposes. The mechanism by which V. fischeri manages these environments to outcompete all other bacterial species for colonization of E. scolopes is an important and intriguing question that will permit valuable insights into how a bacterium successfully associates with a host. This review focuses on specific molecular pathways that allow V. fischeri to establish this exquisite bacteria-host interaction.

  18. Vibrio fischeri exhibit the growth advantage in stationary-phase phenotype.

    Science.gov (United States)

    Petrun, Branden; Lostroh, C Phoebe

    2013-02-01

    Vibrio fischeri are bioluminescent marine bacteria that can be isolated from their symbiotic animal partners or from ocean water. A V. fischeri population increases exponentially inside the light organ of the Hawaiian bobtail squid (Euprymna scolopes) while the host is quiescent during the day. This bacterial light organ population reaches stationary phase and then remains high during the night, when the squid use bacterial bioluminescence as a counter-predation strategy. At dawn, host squid release 90%-95% of the light organ contents into the ocean water prior to burying in the sand for the day. As the squid sleeps, the cycle of bacterial population growth in the light organ begins again. These V. fischeri cells that are vented into the ocean must persist under typical marine low nutrient conditions until they encounter another opportunity to colonize a host. We hypothesized that because V. fischeri regularly encounter cycles of feast and famine in nature, they would exhibit the growth advantage in stationary phase (GASP) phenotype. We found that older V. fischeri cells exhibit a Class 2 GASP response in which old cells increase dramatically in frequency while the population of young V. fischeri cells remains almost constant during co-incubation.

  19. Colonization of Euprymna scolopes squid by Vibrio fischeri.

    Science.gov (United States)

    Naughton, Lynn M; Mandel, Mark J

    2012-03-01

    Specific bacteria are found in association with animal tissue. Such host-bacterial associations (symbioses) can be detrimental (pathogenic), have no fitness consequence (commensal), or be beneficial (mutualistic). While much attention has been given to pathogenic interactions, little is known about the processes that dictate the reproducible acquisition of beneficial/commensal bacteria from the environment. The light-organ mutualism between the marine Gram-negative bacterium V. fischeri and the Hawaiian bobtail squid, E. scolopes, represents a highly specific interaction in which one host (E. scolopes) establishes a symbiotic relationship with only one bacterial species (V. fischeri) throughout the course of its lifetime. Bioluminescence produced by V. fischeri during this interaction provides an anti-predatory benefit to E. scolopes during nocturnal activities, while the nutrient-rich host tissue provides V. fischeri with a protected niche. During each host generation, this relationship is recapitulated, thus representing a predictable process that can be assessed in detail at various stages of symbiotic development. In the laboratory, the juvenile squid hatch aposymbiotically (uncolonized), and, if collected within the first 30-60 minutes and transferred to symbiont-free water, cannot be colonized except by the experimental inoculum. This interaction thus provides a useful model system in which to assess the individual steps that lead to specific acquisition of a symbiotic microbe from the environment. Here we describe a method to assess the degree of colonization that occurs when newly hatched aposymbiotic E. scolopes are exposed to (artificial) seawater containing V. fischeri. This simple assay describes inoculation, natural infection, and recovery of the bacterial symbiont from the nascent light organ of E. scolopes. Care is taken to provide a consistent environment for the animals during symbiotic development, especially with regard to water quality and light

  20. Ecological diversification of Vibrio fischeri serially passaged for 500 generations in novel squid host Euprymna tasmanica.

    Science.gov (United States)

    Soto, William; Rivera, Ferdinand M; Nishiguchi, Michele K

    2014-04-01

    Vibrio fischeri isolated from Euprymna scolopes (Cephalopoda: Sepiolidae) was used to create 24 lines that were serially passaged through the non-native host Euprymna tasmanica for 500 generations. These derived lines were characterized for biofilm formation, swarming motility, carbon source utilization, and in vitro bioluminescence. Phenotypic assays were compared between "ES" (E. scolopes) and "ET" (E. tasmanica) V. fischeri wild isolates to determine if convergent evolution was apparent between E. tasmanica evolved lines and ET V. fischeri. Ecological diversification was observed in utilization of most carbon sources examined. Convergent evolution was evident in motility, biofilm formation, and select carbon sources displaying hyperpolymorphic usage in V. fischeri. Convergence in bioluminescence (a 2.5-fold increase in brightness) was collectively evident in the derived lines relative to the ancestor. However, dramatic changes in other properties--time points and cell densities of first light emission and maximal light output and emergence of a lag phase in growth curves of derived lines--suggest that increased light intensity per se was not the only important factor. Convergent evolution implies that gnotobiotic squid light organs subject colonizing V. fischeri to similar selection pressures. Adaptation to novel hosts appears to involve flexible microbial metabolism, establishment of biofilm and swarmer V. fischeri ecotypes, and complex changes in bioluminescence. Our data demonstrate that numerous alternate fitness optima or peaks are available to V. fischeri in host adaptive landscapes, where novel host squids serve as habitat islands. Thus, V. fischeri founder flushes occur during the initiation of light organ colonization that ultimately trigger founder effect diversification.

  1. Ecological Diversification of Vibrio fischeri Serially Passaged for 500 Generations in Novel Squid Host Euprymna tasmanica

    Science.gov (United States)

    Soto, William; Rivera, Ferdinand M.; Nishiguchi, Michele K.

    2014-01-01

    Vibrio fischeri isolated from Euprymna scolopes (Cephalopoda: Sepiolidae) was used to create twenty-four lines that were serially passaged through the non-native host E. tasmanica for 500 generations. These derived lines were characterized for biofilm formation, swarming motility, carbon source utilization, and in vitro bioluminescence. Phenotypic assays were compared between “ES” (E. scolopes) and “ET” (E. tasmanica) V. fischeri wild isolates to determine if convergent evolution was apparent between E. tasmanica evolved lines and ET V. fischeri. Ecological diversification was observed in utilization of most carbon sources examined. Convergent evolution was evident in motility, biofilm formation, and select carbon sources displaying hyperpolymorphic usage in V. fischeri. Convergence in bioluminescence (a 2.5-fold increase in brightness) was collectively evident in the derived lines relative to the ancestor. However, dramatic changes in other properties—time points and cell densities of first light emission and maximal light output and emergence of a lag phase in growth curves of derived lines suggest increased light intensity per se was not the only important factor. Convergent evolution implies gnotobiotic squid light organs subject colonizing V. fischeri to similar selection pressures. Adaptation to novel hosts appears to involve flexible microbial metabolism, establishment of biofilm and swarmer V. fischeri ecotypes, and complex changes in bioluminescence. Our data demonstrate numerous alternate fitness optima or peaks are available to V. fischeri in host adaptive landscapes, where novel host squids serve as habitat islands. Thus, V. fischeri founder flushes occur during the initiation of light organ colonization that ultimately trigger founder effect diversification. PMID:24402368

  2. The Role of Light Organ Symbiosis in the Distribution and Diversity of the Marine Luminous Bacterium Vibrio Fischeri

    Science.gov (United States)

    1993-06-01

    of the marine luminous bacterium Vibrio fischeri NOOO14-91-J-1670 Li L AUTHOR(S) Edward G. Ruby Di t .b-.ti&-- ś. PERFORMING ORGANIZATION NAME(S...2. Lee, K.-H., and E.G. Ruby (1992) Detection of the light organ symbiont Vibrio fischeri in Hawaiian seawater using luj gene probes. Appl. Environ...the presence of a significant population of typically ’- m culturable V. fischeri cells in seawater that have entered a non-culturable state from which

  3. Colonization of Euprymna scolopes Squid by Vibrio fischeri

    Science.gov (United States)

    Naughton, Lynn M.; Mandel, Mark J.

    2012-01-01

    Specific bacteria are found in association with animal tissue1-5. Such host-bacterial associations (symbioses) can be detrimental (pathogenic), have no fitness consequence (commensal), or be beneficial (mutualistic). While much attention has been given to pathogenic interactions, little is known about the processes that dictate the reproducible acquisition of beneficial/commensal bacteria from the environment. The light-organ mutualism between the marine Gram-negative bacterium V. fischeri and the Hawaiian bobtail squid, E. scolopes, represents a highly specific interaction in which one host (E. scolopes) establishes a symbiotic relationship with only one bacterial species (V. fischeri) throughout the course of its lifetime6,7. Bioluminescence produced by V. fischeri during this interaction provides an anti-predatory benefit to E. scolopes during nocturnal activities8,9, while the nutrient-rich host tissue provides V. fischeri with a protected niche10. During each host generation, this relationship is recapitulated, thus representing a predictable process that can be assessed in detail at various stages of symbiotic development. In the laboratory, the juvenile squid hatch aposymbiotically (uncolonized), and, if collected within the first 30-60 minutes and transferred to symbiont-free water, cannot be colonized except by the experimental inoculum6. This interaction thus provides a useful model system in which to assess the individual steps that lead to specific acquisition of a symbiotic microbe from the environment11,12. Here we describe a method to assess the degree of colonization that occurs when newly hatched aposymbiotic E. scolopes are exposed to (artificial) seawater containing V. fischeri. This simple assay describes inoculation, natural infection, and recovery of the bacterial symbiont from the nascent light organ of E. scolopes. Care is taken to provide a consistent environment for the animals during symbiotic development, especially with regard to water

  4. Squid-derived chitin oligosaccharides are a chemotactic signal during colonization by Vibrio fischeri.

    Science.gov (United States)

    Mandel, Mark J; Schaefer, Amy L; Brennan, Caitlin A; Heath-Heckman, Elizabeth A C; Deloney-Marino, Cindy R; McFall-Ngai, Margaret J; Ruby, Edward G

    2012-07-01

    Chitin, a polymer of N-acetylglucosamine (GlcNAc), is noted as the second most abundant biopolymer in nature. Chitin serves many functions for marine bacteria in the family Vibrionaceae ("vibrios"), in some instances providing a physical attachment site, inducing natural genetic competence, and serving as an attractant for chemotaxis. The marine luminous bacterium Vibrio fischeri is the specific symbiont in the light-emitting organ of the Hawaiian bobtail squid, Euprymna scolopes. The bacterium provides the squid with luminescence that the animal uses in an antipredatory defense, while the squid supports the symbiont's nutritional requirements. V. fischeri cells are harvested from seawater during each host generation, and V. fischeri is the only species that can complete this process in nature. Furthermore, chitin is located in squid hemocytes and plays a nutritional role in the symbiosis. We demonstrate here that chitin oligosaccharides produced by the squid host serve as a chemotactic signal for colonizing bacteria. V. fischeri uses the gradient of host chitin to enter the squid light organ duct and colonize the animal. We provide evidence that chitin serves a novel function in an animal-bacterial mutualism, as an animal-produced bacterium-attracting synomone.

  5. Assessing single and joint toxicity of three phenylurea herbicides using Lemna minor and Vibrio fischeri bioassays.

    Science.gov (United States)

    Gatidou, Georgia; Stasinakis, Athanasios S; Iatrou, Evangelia I

    2015-01-01

    Single and joint toxicity of three substituted urea herbicides, namely monolinuron [3-(4-chlorophenyl)-1-methoxy-1-methylurea], linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea] and diuron [1-(3,4 dichlorophenyl)-3,3 dimethyl urea], were studied. The duckweed Lemna minor and the luminescent bacterium Vibrio fischeri were used for the toxicity assessment and they were exposed to various concentrations of the herbicides, individually and in binary mixtures. The exposure time was 7d for the duckweed and 30 min for the bacterium. Estimation of EC50 values was performed by frond counting and reduction in light output for Lemna minor and Vibrio fischeri, respectively. Lemna minor was found to be much more sensitive than Vibrio fischeri to target compounds. The toxicity of the three herbicides applied solely was estimated to be in decreasing order: diuron (EC50=28.3 μg L(-1))≈linuron (EC50=30.5 μg L(-1))>monolinuron (EC50=300 μg L(-1)) for the duckweed and linuron (EC50=8.2 mg L(-1))>diuron (EC50=9.2 mg L(-1))>monolinuron (EC50=11.2 mg L(-1)) for the bacterium. Based on the environmental concentrations reported in the literature and EC50 values obtained from Lemna minor experiments, Risk Quotients (RQ) much higher than 1 were calculated for diuron and linuron. In Lemna minor experiments, combination of target compounds resulted to additive effects due to their same mode of phenylurea action on photosynthetic organisms. Regarding Vibrio fischeri, synergistic, additive and antagonistic effects were observed, which varied according to the concentrations of target compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Coordination of the Arc Regulatory System and Pheromone-Mediated Positive Feedback in Controlling the Vibrio fischeri lux Operon: e49590

    National Research Council Canada - National Science Library

    Alecia N Septer; Eric V Stabb

    2012-01-01

    .... We have explored the interplay between an environmentally responsive regulator and pheromone-mediated positive feedback in intercellular signaling by Vibrio fischeri ES114, a bioluminescent bacterium...

  7. Polyphyly of non-bioluminescent Vibrio fischeri sharing a lux-locus deletion.

    Science.gov (United States)

    Wollenberg, M S; Preheim, S P; Polz, M F; Ruby, E G

    2012-03-01

    This study reports the first description and molecular characterization of naturally occurring, non-bioluminescent strains of Vibrio fischeri. These 'dark' V. fischeri strains remained non-bioluminescent even after treatment with both autoinducer and aldehyde, substrate additions that typically maximize light production in dim strains of luminous bacteria. Surprisingly, the entire lux locus (eight genes) was absent in over 97% of these dark V. fischeri strains. Although these strains were all collected from a Massachusetts (USA) estuary in 2007, phylogenetic reconstructions allowed us to reject the hypothesis that these newly described non-bioluminescent strains exhibit monophyly within the V. fischeri clade. These dark strains exhibited a competitive disadvantage against native bioluminescent strains when colonizing the light organ of the model V. fischeri host, the Hawaiian bobtail squid Euprymna scolopes. Significantly, we believe that the data collected in this study may suggest the first observation of a functional, parallel locus-deletion event among independent lineages of a non-pathogenic bacterial species. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  8. Genome-Wide Biases in the Rate and Molecular Spectrum of Spontaneous Mutations in Vibrio cholerae and Vibrio fischeri.

    Science.gov (United States)

    Dillon, Marcus M; Sung, Way; Sebra, Robert; Lynch, Michael; Cooper, Vaughn S

    2017-01-01

    The vast diversity in nucleotide composition and architecture among bacterial genomes may be partly explained by inherent biases in the rates and spectra of spontaneous mutations. Bacterial genomes with multiple chromosomes are relatively unusual but some are relevant to human health, none more so than the causative agent of cholera, Vibrio cholerae Here, we present the genome-wide mutation spectra in wild-type and mismatch repair (MMR) defective backgrounds of two Vibrio species, the low-%GC squid symbiont V. fischeri and the pathogen V. cholerae, collected under conditions that greatly minimize the efficiency of natural selection. In apparent contrast to their high diversity in nature, both wild-type V. fischeri and V. cholerae have among the lowest rates for base-substitution mutations (bpsms) and insertion-deletion mutations (indels) that have been measured, below 10(-)(3)/genome/generation. Vibrio fischeri and V. cholerae have distinct mutation spectra, but both are AT-biased and produce a surprising number of multi-nucleotide indels. Furthermore, the loss of a functional MMR system caused the mutation spectra of these species to converge, implying that the MMR system itself contributes to species-specific mutation patterns. Bpsm and indel rates varied among genome regions, but do not explain the more rapid evolutionary rates of genes on chromosome 2, which likely result from weaker purifying selection. More generally, the very low mutation rates of Vibrio species correlate inversely with their immense population sizes and suggest that selection may not only have maximized replication fidelity but also optimized other polygenic traits relative to the constraints of genetic drift. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  9. Comparative analysis reveals regulatory motifs at the ainS/ainR pheromone-signaling locus of Vibrio fischeri.

    Science.gov (United States)

    Kimbrough, John H; Stabb, Eric V

    2017-09-15

    Vibrio fischeri uses the AinS/AinR pheromone-signaling system to control bioluminescence and other symbiotic colonization factors. The Ain system is thought to initiate cell-cell signaling at moderate cell densities and to prime the LuxI/LuxR signaling system. Here we compared and analyzed the ain locus from two V. fischeri strains and a Vibrio salmonicida strain to explore ain regulation. The ainS and ainR genes were predicted to constitute an operon, which we corroborated using RT-PCR. Comparisons between strains revealed a stark area of conservation across the ainS-ainR junction, including a large inverted repeat in ainR. We found that this inverted repeat in cis can affect accumulation of the AinS-generated pheromone N-octanoyl homoserine lactone, which may account for the previously unexplained low-signal phenotype of a ∆ainR mutant, although the mechanism behind this regulation remains elusive. We also extended the previous observation of a possible "lux box" LuxR binding site upstream of ainS by showing the conservation of this site as well as a second putative lux box. Using a plasmid-based reporter we found that LuxR can mediate repression of ainS, providing a negative feedback mechanism in the Ain/Lux signaling cascade. Our results provide new insights into the regulation, expression, and evolution of ainSR.

  10. Assessing chemical toxicity of ionic liquids on Vibrio fischeri: Correlation with structure and composition.

    Science.gov (United States)

    Montalbán, Mercedes G; Hidalgo, Juana M; Collado-González, Mar; Díaz Baños, F Guillermo; Víllora, Gloria

    2016-07-01

    One of the most important properties of ionic liquids is their non-volatility, making them potentially "green" alternatives to volatile organic compounds. However, they are widely soluble in water, meaning that they can be released into aquatic ecosystems and so contribute to water pollution. Nevertheless, although the toxicity of ILs has been widely assessed in the literature, the information is still scarce due to the great number of ionic liquids that have been synthesized. The present work reports the toxicity of twenty-nine imidazolium-, pyridinium- and ammonium-based ionic liquids towards the bioluminescent photobacterium Vibrio fischeri. When the effect of the type of anion, the length of the alkyl chain of the cation, the cation core and the presence of a functionalized side chain in the cation on ionic liquid toxicity were analyzed, the main influence was seen to be exercised by the alkyl chain length. A Quantitative Structure-Activity Relationships-based method was used to compare the experimental results with previously estimated values and very good agreement was obtained. A relationship between the toxicity, expressed as Log EC50, and the 1-octanol-water partition coefficient was established. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Ecotoxicological screening of reclaimed disinfected wastewater by Vibrio fischeri bioassay after a chlorination-dechlorination process.

    Science.gov (United States)

    Bayo, Javier; Angosto, José M; Gómez-López, M Dolores

    2009-12-15

    It is well known that different substances can react with chlorine in a water disinfection process to produce disinfection by-products (DBPs). Some of these substances have proven to be carcinogenic in humans and animals. Because it is not possible to detect all DBPs produced in chlorinated wastewater, toxicity tests have been proposed as a useful tool for screening toxic chemicals in treated wastewater. In this study, the Microtox bioassay with Vibrio fischeri was used to evaluate the formation of toxic by-products in wastewater, after a chlorination-dechlorination disinfection treatment. All the variables were found to be normally distributed, so analysis of variance could be directly applied without transformation of variables. Significant correlations were obtained between toxicity values and total carbon, total inorganic carbon, total nitrogen, chlorine, and pH. In contrast, total organic carbon, chemical oxygen demand, electrical conductivity and turbidity had no effect on toxicity formation. Toxicity increased with the Cl2:NH4+ ratio at a higher chlorine concentration released from combined chlorine. Regression models provided a good fit for effective concentration (EC50) as a function of total carbon and total nitrogen, after 5, 10, and 15 min of exposure. These models had greater multiple determination coefficients than previously reported for similar studies, without autocorrelation in the residuals as indicated by the Durbin-Watson statistic test. The measured and predicted ecotoxicity values were strongly correlated.

  12. The iron-dependent regulator fur controls pheromone signaling systems and luminescence in the squid symbiont Vibrio fischeri ES114.

    Science.gov (United States)

    Septer, Alecia N; Lyell, Noreen L; Stabb, Eric V

    2013-03-01

    Bacteria often use pheromones to coordinate group behaviors in specific environments. While high cell density is required for pheromones to achieve stimulatory levels, environmental cues can also influence pheromone accumulation and signaling. For the squid symbiont Vibrio fischeri ES114, bioluminescence requires pheromone-mediated regulation, and this signaling is induced in the host to a greater extent than in culture, even at an equivalent cell density. Our goal is to better understand this environment-specific control over pheromone signaling and bioluminescence. Previous work with V. fischeri MJ1 showed that iron limitation induces luminescence, and we recently found that ES114 encounters a low-iron environment in its host. Here we show that ES114 induces luminescence at lower cell density and achieves brighter luminescence in low-iron media. This iron-dependent effect on luminescence required ferric uptake regulator (Fur), which we propose influences two pheromone signaling master regulators, LitR and LuxR. Genetic and bioinformatic analyses suggested that under low-iron conditions, Fur-mediated repression of litR is relieved, enabling more LitR to perform its established role as an activator of luxR. Interestingly, Fur may similarly control the LitR homolog SmcR of Vibrio vulnificus. These results reveal an intriguing regulatory link between low-iron conditions, which are often encountered in host tissues, and pheromone-dependent master regulators.

  13. Observing Chemotaxis in Vibrio fischeri Using Soft Agar Assays in an Undergraduate Microbiology Laboratory

    Directory of Open Access Journals (Sweden)

    Cindy R. DeLoney-Marino

    2013-08-01

    Full Text Available Chemotaxis, the directed movement of cells towards or away from a chemical, is both an exciting and complicated behavior observed in many bacterial species. Attempting to adequately visualize or demonstrate the chemotaxic response of bacteria in the classroom is difficult at best, with good models to illustrate the concept lacking. The BSL-1 marine bacterium Vibrio fischeri (a.k.a. Aliivibrio fischeri is easy to culture, making it an ideal candidate for experiments in an undergraduate microbiology course. A number of chemoattractants for V. fischeri have been identified, including a variety of sugars, nucleosides, and amino acids (1, 2. Below presents how the soft agar-based chemotaxis assay can be implemented in the undergraduate laboratory. As bacterial cells migrate towards one or more attractants in soft agar, students can directly observe the chemotaxic behavior of V. fischeri without the need to learn complicated techniques or use specialized equipment. Once the bands of bacterial cells are observed, the migration can then be disrupted by the addition of excess attractant to the soft agar, thereby visualizing what happens once cells are no longer in a gradient of attractant. In addition, soft agar plates lacking attractants can be used to visualize the random movements of bacterial cells that are non-chemotaxing. These exercises can be used in the microbiology laboratory to help students understand the complex behavior of bacterial chemotaxis.

  14. Comparisons of Vibrio fischeri, Photobacterium phosphoreum, and recombinant luminescent using Escherichia coli as BOD measurement.

    Science.gov (United States)

    Cheng, Chiu-Yu; Kuo, Jong-Tar; Lin, Yu-Cheng; Liao, Yi-Ru; Chung, Ying-Chien

    2010-01-01

    To shorten the time needed to measure biochemical oxygen demand (BOD) in water samples and to provide a rapid feedback of the real condition of water quality, we tested and evaluated the validity and reliability of luminescent bacteria Vibrio fischeri, Photobacterium phosphoreum, and recombinant Escherichia coli as potential indicators of BOD in the domestic wastewaters. The results indicate that the luminescence intensities of these strains are dependent on temperature, pH, and BOD concentration. In comparison to the standard BOD(5) method, the time needed for BOD measurement can be shortened by 90, 120, and 150 min when V. fischeri, P. phosphoreum, and recombinant E. coli, respectively, are used. Recombinant E. coli can be adapted to measure BOD in domestic wastewater containing a wide range of BOD concentrations, V. fischeri is not suitable for measuring diluted wastewater, and P. phosphoreum has only a limited application in measuring concentrated wastewater. To the best of our knowledge, this is the first report in which V. fischeri, P. phosphoreum, and recombinant luminescent E. coli are compared in terms of their potential in BOD measurement systems.

  15. Toxicity assessment of ionic liquids with Vibrio fischeri: an alternative fully automated methodology.

    Science.gov (United States)

    Costa, Susana P F; Pinto, Paula C A G; Lapa, Rui A S; Saraiva, M Lúcia M F S

    2015-03-02

    A fully automated Vibrio fischeri methodology based on sequential injection analysis (SIA) has been developed. The methodology was based on the aspiration of 75 μL of bacteria and 50 μL of inhibitor followed by measurement of the luminescence of bacteria. The assays were conducted for contact times of 5, 15, and 30 min, by means of three mixing chambers that ensured adequate mixing conditions. The optimized methodology provided a precise control of the reaction conditions which is an asset for the analysis of a large number of samples. The developed methodology was applied to the evaluation of the impact of a set of ionic liquids (ILs) on V. fischeri and the results were compared with those provided by a conventional assay kit (Biotox(®)). The collected data evidenced the influence of different cation head groups and anion moieties on the toxicity of ILs. Generally, aromatic cations and fluorine-containing anions displayed higher impact on V. fischeri, evidenced by lower EC50. The proposed methodology was validated through statistical analysis which demonstrated a strong positive correlation (P>0.98) between assays. It is expected that the automated methodology can be tested for more classes of compounds and used as alternative to microplate based V. fischeri assay kits. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Ecotoxicological evaluation of selected pharmaceuticals to Vibrio fischeri and Daphnia magna before and after photooxidation process.

    Science.gov (United States)

    Czech, Bożena; Jośko, Izabela; Oleszczuk, Patryk

    2014-06-01

    The aim of the research was the determination of the toxicity of photocatalytically treated water contaminated by different pharmaceuticals: chloramphenicol (CPL), diclofenac (DCF) or metoprolol (MT). Daphtoxkit F™ with Dapnia magna and Microtox(®) with Vibrio fischeri were used to evaluate the toxicity of the water before and after treatment. D. magna showed higher sensitivity to the presence of pharmaceuticals than V. fischeri. Generally, both tested organisms revealed the greatest sensitivity to the presence of CPL. The application of photocatalytic oxidation has resulted in decreased toxicity. It may confirm the reduction of high toxic parent compounds to less toxic metabolites. The toxicity was reduced in the range from 30% to 100% depending on pharmaceutical tested. The highest reduction of toxicity to V. fischeri and D. magna was observed to MT and CPL respectively. Depending on bioassay the toxicity decrease as follows: CPL>DCF>MT for D. magna and CPL>MT>DCF for V. fischeri. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Population structure of Vibrio fischeri within the light organs of Euprymna scolopes squid from Two Oahu (Hawaii) populations.

    Science.gov (United States)

    Wollenberg, M S; Ruby, E G

    2009-01-01

    We resolved the intraspecific diversity of Vibrio fischeri, the bioluminescent symbiont of the Hawaiian sepiolid squid Euprymna scolopes, at two previously unexplored morphological and geographical scales. These scales ranged from submillimeter regions within the host light organ to the several kilometers encompassing two host populations around Oahu. To facilitate this effort, we employed both novel and standard genetic and phenotypic assays of light-organ symbiont populations. A V. fischeri-specific fingerprinting method and five phenotypic assays were used to gauge the genetic richness of V. fischeri populations; these methods confirmed that the symbiont population present in each adult host's light organ is polyclonal. Upon statistical analysis of these genetic and phenotypic population data, we concluded that the characteristics of symbiotic populations were more similar within individual host populations than between the two distinct Oahu populations of E. scolopes, providing evidence that local geographic symbiont population structure exists. Finally, to better understand the genesis of symbiont diversity within host light organs, the process of symbiosis initiation in newly hatched juvenile squid was examined both experimentally and by mathematical modeling. We concluded that, after the juvenile hatches, only one or two cells of V. fischeri enter each of six internal epithelium-lined crypts present in the developing light organ. We hypothesize that the expansion of different, crypt-segregated, clonal populations creates the polyclonal adult light-organ population structure observed in this study. The stability of the luminous-bacterium-sepiolid squid mutualism in the presence of a polyclonal symbiont population structure is discussed in the context of contemporary evolutionary theory.

  18. Population Structure of Vibrio fischeri within the Light Organs of Euprymna scolopes Squid from Two Oahu (Hawaii) Populations▿ †

    Science.gov (United States)

    Wollenberg, M. S.; Ruby, E. G.

    2009-01-01

    We resolved the intraspecific diversity of Vibrio fischeri, the bioluminescent symbiont of the Hawaiian sepiolid squid Euprymna scolopes, at two previously unexplored morphological and geographical scales. These scales ranged from submillimeter regions within the host light organ to the several kilometers encompassing two host populations around Oahu. To facilitate this effort, we employed both novel and standard genetic and phenotypic assays of light-organ symbiont populations. A V. fischeri-specific fingerprinting method and five phenotypic assays were used to gauge the genetic richness of V. fischeri populations; these methods confirmed that the symbiont population present in each adult host's light organ is polyclonal. Upon statistical analysis of these genetic and phenotypic population data, we concluded that the characteristics of symbiotic populations were more similar within individual host populations than between the two distinct Oahu populations of E. scolopes, providing evidence that local geographic symbiont population structure exists. Finally, to better understand the genesis of symbiont diversity within host light organs, the process of symbiosis initiation in newly hatched juvenile squid was examined both experimentally and by mathematical modeling. We concluded that, after the juvenile hatches, only one or two cells of V. fischeri enter each of six internal epithelium-lined crypts present in the developing light organ. We hypothesize that the expansion of different, crypt-segregated, clonal populations creates the polyclonal adult light-organ population structure observed in this study. The stability of the luminous-bacterium-sepiolid squid mutualism in the presence of a polyclonal symbiont population structure is discussed in the context of contemporary evolutionary theory. PMID:18997024

  19. LuxCDABE?Transformed Constitutively Bioluminescent Escherichia coli for Toxicity Screening: Comparison with Naturally Luminous Vibrio fischeri

    OpenAIRE

    Anne Kahru; Olesja Bondarenko; Mariliis Sihtmäe; Imbi Kurvet; Angela Ivask

    2011-01-01

    We show that in vitro toxicity assay based on inhibition of the bioluminescence of recombinant Escherichia coli encoding thermostable luciferase from Photorhabdus luminescens is a versatile alternative to Vibrio fischeri MicrotoxTM test. Performance of two luxCDABE-transformed E. coli MC1061 constructs (pDNlux) and (pSLlux) otherwise identical, but having 100-fold different background luminescence was compared with the performance of V. fischeri. The microplate luminometer and a kinetic Flash...

  20. Vibrio fischeri Outer Membrane Protein OmpU Plays a Role in Normal Symbiotic Colonization

    Science.gov (United States)

    Aeckersberg, F.; Lupp, C.; Feliciano, B.; Ruby, E. G.

    2001-01-01

    The nascent light-emitting organ of newly hatched juveniles of the Hawaiian sepiolid squid Euprymna scolopes is specifically colonized by cells of Vibrio fischeri that are obtained from the ambient seawater. The mechanisms that promote this specific, cooperative colonization are likely to require a number of bacterial and host-derived factors and activities, only some of which have been described to date. A characteristic of many host-pathogen associations is the presence of bacterial mechanisms that allow attachment to specific tissues. These mechanisms have been well characterized and often involve bacterial fimbriae or outer membrane proteins (OMPs) that act as adhesins, the expression of which has been linked to virulence regulators such as ToxR in Vibrio cholerae. Analogous or even homologous mechanisms are probably operative in the initiation and persistence of cooperative bacterial associations, although considerably less is known about them. We report the presence in V. fischeri of ompU, a gene encoding a 32.5-kDa protein homolog of two other OMPs, OmpU of V. cholerae (50.8% amino acid sequence identity) and OmpL of Photobacterium profundum (45.5% identity). A null mutation introduced into the V. fischeri ompU resulted in the loss of an OMP with an estimated molecular mass of about 34 kDa; genetic complementation of the mutant strain with a DNA fragment containing only the ompU gene restored the production of this protein. The expression of the V. fischeri OmpU was not significantly affected by either (i) iron or phosphate limitation or (ii) a mutation that renders V. fischeri defective in the synthesis of a homolog of the OMP-regulatory protein ToxR. The ompU mutant grew normally in complex nutrient media but was more susceptible to growth inhibition in the presence of either anionic detergents or the antimicrobial peptide protamine sulfate. Interestingly, colonization experiments showed that the ompU null mutant initiated a symbiotic association with

  1. Impact of Salt and Nutrient Content on Biofilm Formation by Vibrio fischeri.

    Science.gov (United States)

    Marsden, Anne E; Grudzinski, Kevin; Ondrey, Jakob M; DeLoney-Marino, Cindy R; Visick, Karen L

    2017-01-01

    Vibrio fischeri, a marine bacterium and symbiont of the Hawaiian bobtail squid Euprymna scolopes, depends on biofilm formation for successful colonization of the squid's symbiotic light organ. Here, we investigated if culture conditions, such as nutrient and salt availability, affect biofilm formation by V. fischeri by testing the formation of wrinkled colonies on solid media. We found that V. fischeri forms colonies with more substantial wrinkling when grown on the nutrient-dense LBS medium containing NaCl relative to those formed on the more nutrient-poor, seawater-salt containing SWT medium. The presence of both tryptone and yeast extract was necessary for the production of "normal" wrinkled colonies; when grown on tryptone alone, the colonies displayed a divoting phenotype and were attached to the agar surface. We also found that the type and concentration of specific seawater salts influenced the timing of biofilm formation. Of the conditions assayed, wrinkled colony formation occurred earliest in LBS(-Tris) media containing 425 mM NaCl, 35 mM MgSO4, and 5 mM CaCl2. Pellicle formation, another measure of biofilm development, was also enhanced in these growth conditions. Therefore, both nutrient and salt availability contribute to V. fischeri biofilm formation. While growth was unaffected, these optimized conditions resulted in increased syp locus expression as measured by a PsypA-lacZ transcriptional reporter. We anticipate these studies will help us understand how the natural environment of V. fischeri affects its ability to form biofilms and, ultimately, colonize E. scolopes.

  2. Rotation of Vibrio fischeri Flagella Produces Outer Membrane Vesicles That Induce Host Development.

    Science.gov (United States)

    Aschtgen, Marie-Stephanie; Lynch, Jonathan B; Koch, Eric; Schwartzman, Julia; McFall-Ngai, Margaret; Ruby, Edward

    2016-08-15

    Using the squid-vibrio association, we aimed to characterize the mechanism through which Vibrio fischeri cells signal morphogenesis of the symbiotic light-emitting organ. The symbiont releases two cell envelope molecules, peptidoglycan (PG) and lipopolysaccharide (LPS) that, within 12 h of light organ colonization, act in synergy to trigger normal tissue development. Recent work has shown that outer membrane vesicles (OMVs) produced by V. fischeri are sufficient to induce PG-dependent morphogenesis; however, the mechanism(s) of OMV release by these bacteria has not been described. Like several genera of both beneficial and pathogenic bacteria, V. fischeri cells elaborate polar flagella that are enclosed by an extension of the outer membrane, whose function remains unclear. Here, we present evidence that along with the well-recognized phenomenon of blebbing from the cell's surface, rotation of this sheathed flagellum also results in the release of OMVs. In addition, we demonstrate that most of the development-inducing LPS is associated with these OMVs and that the presence of the outer membrane protein OmpU but not the LPS O antigen on these OMVs is important in triggering normal host development. These results also present insights into a possible new mechanism of LPS release by pathogens with sheathed flagella. Determining the function(s) of sheathed flagella in bacteria has been challenging, because no known mutation results only in the loss of this outer membrane-derived casing. Nevertheless, the presence of a sheathed flagellum in such host-associated genera as Vibrio, Helicobacter, and Brucella has led to several proposed functions, including physical protection of the flagella and masking of their immunogenic flagellins. Using the squid-vibrio light organ symbiosis, we demonstrate another role, that of V. fischeri cells require rotating flagella to induce apoptotic cell death within surface epithelium, which is a normal step in the organ's development

  3. The novel sigma factor-like regulator RpoQ controls luminescence, chitinase activity, and motility in Vibrio fischeri.

    Science.gov (United States)

    Cao, Xiaodan; Studer, Sarah V; Wassarman, Karen; Zhang, Yuanxing; Ruby, Edward G; Miyashiro, Tim

    2012-01-01

    Vibrio fischeri, the bacterial symbiont of the Hawaiian bobtail squid, Euprymna scolopes, uses quorum sensing to control genes involved in bioluminescence, host colonization, and other biological processes. Previous work has shown that AinS/R-directed quorum sensing also regulates the expression of rpoQ (VF_A1015), a gene annotated as an RpoS-like sigma factor. In this study, we demonstrate using phylogenetics that RpoQ is related to, but distinct from, the stationary-phase sigma factor RpoS. Overexpression of rpoQ results in elevated chitinase activity but decreased motility and luminescence, three activities associated with symbiosis. The reduction in bacterial luminescence associated with the overexpression of rpoQ occurs both in culture and within the light-emitting organ of the squid host. This suppression of bioluminescence is due to the repression of the luxICDABEG promoter. Our results highlight RpoQ as a novel regulatory component, embedded in the quorum-signaling network that controls several biological processes in V. fischeri. Quorum signaling is a widely occurring phenomenon that functions in diverse bacterial taxa. It is most often found associated with species that interact with animal or plant hosts, either as mutualists or pathogens, and controls the expression of genes critical to tissue colonization. We present the discovery of rpoQ, which encodes a new regulatory component in the quorum-signaling pathway of Vibrio fischeri. RpoQ is a novel protein in the RpoS family of stationary-phase sigma factors. Unlike many other regulatory proteins involved in the quorum-signaling pathways of the Vibrionaceae, the distribution of RpoQ appears to be restricted to only two closely related species. The role of this regulator is to enhance some quorum-signaling outputs (motility) while suppressing others (luminescence). We propose that RpoQ may be a recently evolved or acquired component in V. fischeri that provides this organism with an additional level of

  4. Toxicity evaluation of pharmaceutical wastewaters using the alga Scenedesmus obliquus and the bacterium Vibrio fischeri.

    Science.gov (United States)

    Yu, Xin; Zuo, Jiane; Tang, Xinyao; Li, Ruixia; Li, Zaixing; Zhang, Fei

    2014-02-15

    The toxicity of pharmaceutical wastewaters has recently been the focus of the public in China. This study aimed to evaluate the conventional pollution parameters and toxicities of different raw and treated pharmaceutical wastewaters to algae Scenedesmus obliquus and bacteria Vibrio fischeri. Wastewater samples were collected from 16 pharmaceutical wastewater treatment plants in China. The results of the conventional parameters analysis indicated that the total suspended solids, chemical oxygen demand (COD), ammonia (NH3-N), and total phosphorus (TP) were largely removed after treatment. Pharmaceutical effluents were mainly polluted with organics and phosphorus as indicated by the average COD (388 mg/L) and TP (3.16 mg/L) concentrations. The toxicity test results indicated that the influent samples were toxic to both test species. Although the toxicities could be remarkably reduced after treatment, 10 out of the 16 effluent samples exceeded the acute toxicity discharge limit of the Chinese national standards. Spearman rank correlation coefficients indicated a significantly positive correlation between the toxicity values of S. obliquus and V. fischeri. Compared with S. obliquus, V. fischeri detected more pharmaceutical effluent samples with toxicities. Meanwhile, the toxicity indicators were significantly and positively correlated with the COD and NH3-N concentrations based on a Spearman rank correlation analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. The putative oligosaccharide translocase SypK connects biofilm formation with quorum signaling in Vibrio fischeri.

    Science.gov (United States)

    Miyashiro, Tim; Oehlert, Dane; Ray, Valerie A; Visick, Karen L; Ruby, Edward G

    2014-12-01

    Quorum signaling (QS) describes how bacteria can use small signaling molecules (autoinducers) to coordinate group-level behaviors. In Vibrio fischeri, QS is achieved through a complex regulatory network that ultimately controls bioluminescence, motility, and host colonization. We conducted a genetic screen focused on qrr1, which encodes a small regulatory RNA that is necessary for the core quorum-signaling cascade to transduce autoinducer information into cellular responses. We isolated unique mutants with a transposon inserted into one of two genes within the syp locus, which is involved in biofilm formation. We found that overexpression of sypK, which encodes a putative oligosaccharide translocase, is sufficient to activate qrr1, and, in addition, this effect appears to depend on the kinase activity of the sensor LuxQ. Consistent with the established model for QS in V. fischeri, enhanced expression of qrr1 by the overexpression of sypK resulted in reduced bioluminescence and increased motility. Finally, we found that induction of the syp locus by overexpression of sypG was sufficient to activate qrr1 levels. Together, our results show how conditions that promote biofilm formation impact the quorum-signaling network in V. fischeri, and further highlight the integrated nature of the regulatory circuits involved in complex bacterial behaviors. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  6. Characterization of the Vibrio fischeri Fatty Acid Chemoreceptors, VfcB and VfcB2.

    Science.gov (United States)

    Nikolakakis, K; Monfils, K; Moriano-Gutierrez, S; Brennan, C A; Ruby, E G

    2015-11-13

    Bacteria use a wide variety of methyl-accepting chemotaxis proteins (MCPs) to mediate their attraction to or repulsion from different chemical signals in their environment. The bioluminescent marine bacterium Vibrio fischeri is the monospecific symbiont of the Hawaiian bobtail squid, Euprymna scolopes, and encodes a large repertoire of MCPs that are hypothesized to be used during different parts of its complex, multistage lifestyle. Here, we report the initial characterization of two such MCPs from V. fischeri that are responsible for mediating migration toward short- and medium-chain aliphatic (or fatty) acids. These receptors appear to be distributed among only members of the family Vibrionaceae and are likely descended from a receptor that has been lost by the majority of the members of this family. While chemotaxis greatly enhances the efficiency of host colonization by V. fischeri, fatty acids do not appear to be used as a chemical cue during this stage of the symbiosis. This study presents an example of straight-chain fatty acid chemoattraction and contributes to the growing body of characterized MCP-ligand interactions. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  7. LuxU connects quorum sensing to biofilm formation in Vibrio fischeri.

    Science.gov (United States)

    Ray, Valerie A; Visick, Karen L

    2012-11-01

    Biofilm formation by Vibrio fischeri is a complex process involving multiple regulators, including the sensor kinase (SK) RscS and the response regulator (RR) SypG, which control the symbiosis polysaccharide (syp) locus. To identify other regulators of biofilm formation in V. fischeri, we screened a transposon library for mutants defective in wrinkled colony formation. We identified LuxQ as a positive regulator of syp-dependent biofilm formation. LuxQ is a member of the Lux phosphorelay and is predicted to control bioluminescence in concert with the SK AinR, the phosphotransferase LuxU and the RR LuxO. Of these, LuxU was the only other regulator that exerted a substantial impact on biofilm formation. We propose a model in which the Lux pathway branches at LuxU to control both bioluminescence and biofilm formation. Furthermore, our evidence suggests that LuxU functions to regulate syp transcription, likely by controlling SypG activity. Finally, we found that, in contrast to its predicted function, the SK AinR has little impact on bioluminescence under our conditions. Thus, this study reveals a novel connection between the Lux and Syp pathways in V. fischeri, and furthers our understanding of how the Lux pathway regulates bioluminescence in this organism. © 2012 Blackwell Publishing Ltd.

  8. Heterogeneous response to a quorum-sensing signal in the luminescence of individual Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Pablo Delfino Pérez

    Full Text Available The marine bacterium Vibrio fischeri regulates its bioluminescence through a quorum sensing mechanism: the bacterium releases diffusible small molecules (autoinducers that accumulate in the environment as the population density increases. This accumulation of autoinducer (AI eventually activates transcriptional regulators for bioluminescence as well as host colonization behaviors. Although V. fischeri quorum sensing has been extensively characterized in bulk populations, far less is known about how it performs at the level of the individual cell, where biochemical noise is likely to limit the precision of luminescence regulation. We have measured the time-dependence and AI-dependence of light production by individual V. fischeri cells that are immobilized in a perfusion chamber and supplied with a defined concentration of exogenous AI. We use low-light level microscopy to record and quantify the photon emission from the cells over periods of several hours as they respond to the introduction of AI. We observe an extremely heterogeneous response to the AI signal. Individual cells differ widely in the onset time for their luminescence and in their resulting brightness, even in the presence of high AI concentrations that saturate the light output from a bulk population. The observed heterogeneity shows that although a given concentration of quorum signal may determine the average light output from a population of cells, it provides far weaker control over the luminescence output of each individual cell.

  9. Intraspecific Competition Impacts Vibrio fischeri Strain Diversity during Initial Colonization of the Squid Light Organ.

    Science.gov (United States)

    Sun, Yan; LaSota, Elijah D; Cecere, Andrew G; LaPenna, Kyle B; Larios-Valencia, Jessie; Wollenberg, Michael S; Miyashiro, Tim

    2016-05-15

    Animal development and physiology depend on beneficial interactions with microbial symbionts. In many cases, the microbial symbionts are horizontally transmitted among hosts, thereby making the acquisition of these microbes from the environment an important event within the life history of each host. The light organ symbiosis established between the Hawaiian squid Euprymna scolopes and the bioluminescent bacterium Vibrio fischeri is a model system for examining how hosts acquire horizontally transmitted microbial symbionts. Recent studies have revealed that the light organ of wild-caught E. scolopes squid contains polyclonal populations of V. fischeri bacteria; however, the function and development of such strain diversity in the symbiosis are unknown. Here, we report our phenotypic and phylogenetic characterizations of FQ-A001, which is a V. fischeri strain isolated directly from the light organ of an E. scolopes individual. Relative to the type strain ES114, FQ-A001 exhibits similar growth in rich medium but displays increased bioluminescence and decreased motility in soft agar. FQ-A001 outcompetes ES114 in colonizing the crypt spaces of the light organs. Remarkably, we find that animals cocolonized with FQ-A001 and ES114 harbor singly colonized crypts, in contrast to the cocolonized crypts observed from competition experiments involving single genotypes. The results with our two-strain system suggest that strain diversity within the squid light organ is a consequence of diversity in the single-strain colonization of individual crypt spaces. The developmental programs and overall physiologies of most animals depend on diverse microbial symbionts that are acquired from the environment. However, the basic principles underlying how microbes colonize their hosts remain poorly understood. Here, we report our findings of bacterial strain competition within the coevolved animal-microbe symbiosis composed of the Hawaiian squid and bioluminescent bacterium Vibrio fischeri

  10. Comparative genomics-based investigation of resequencing targets in Vibrio fischeri: Focus on point miscalls and artefactual expansions

    Directory of Open Access Journals (Sweden)

    Ruby Edward G

    2008-03-01

    Full Text Available Abstract Background Sequence closure often represents the end-point of a genome project, without a system in place for subsequent improvement and refinement. Building on the genome project of Vibrio fischeri ES114, we used a comparative approach to identify and investigate genes that had a high likelihood of sequence error. Results Comparison of the V. fischeri ES114 genome with that of conspecific strain MJ11 identified 82 target loci in ES114 as containing likely errors, and thus of high-priority for resequencing. Analysis of the targets identified 75 loci in which an error had occurred, resulting in the correction of 10,457 base pairs to generate the new ES114 genomic sequence. A majority of the inaccurate loci involved frameshift errors, correction of which fused adjacent ORFs. Although insertions/deletions are thought to be rare in microbial genome assemblies, fourteen of the loci contained extraneous sequence of over 300 bp, likely due to imperfect contig ends that were misassembled in tandem rather than as overlapping segments. Additionally we updated the entire genome annotation with 113 new features including previously uncalled protein-coding genes, regulatory RNA genes and operon leader peptides, and we analyzed the transcriptional apparatus encoded by ES114. Conclusion We demonstrate that errors in microbial genome sequences, thought to largely be confined to point mutations, may also consist of other prevalent large-scale rearrangements such as insertions. Ongoing genome quality control and annotation programs are necessary to accompany technological advancements in data generation. These updates further advance V. fischeri as an important model for understanding intercellular communication and colonization of animal tissue.

  11. Genetic determinants of swimming motility in the squid light-organ symbiont Vibrio fischeri.

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    Brennan, Caitlin A; Mandel, Mark J; Gyllborg, Mattias C; Thomasgard, Krista A; Ruby, Edward G

    2013-08-01

    Bacterial flagellar motility is a complex cellular behavior required for the colonization of the light-emitting organ of the Hawaiian bobtail squid, Euprymna scolopes, by the beneficial bioluminescent symbiont Vibrio fischeri. We characterized the basis of this behavior by performing (i) a forward genetic screen to identify mutants defective in soft-agar motility, as well as (ii) a transcriptional analysis to determine the genes that are expressed downstream of the flagellar master regulator FlrA. Mutants with severe defects in soft-agar motility were identified due to insertions in genes with putative roles in flagellar motility and in genes that were unexpected, including those predicted to encode hypothetical proteins and cell division-related proteins. Analysis of mutants for their ability to enter into a productive symbiosis indicated that flagellar motility mutants are deficient, while chemotaxis mutants are able to colonize a subset of juvenile squid to light-producing levels. Thirty-three genes required for normal motility in soft agar were also downregulated in the absence of FlrA, suggesting they belong to the flagellar regulon of V. fischeri. Mutagenesis of putative paralogs of the flagellar motility genes motA, motB, and fliL revealed that motA1, motB1, and both fliL1 and fliL2, but not motA2 and motB2, likely contribute to soft-agar motility. Using these complementary approaches, we have characterized the genetic basis of flagellar motility in V. fischeri and furthered our understanding of the roles of flagellar motility and chemotaxis in colonization of the juvenile squid, including identifying 11 novel mutants unable to enter into a productive light-organ symbiosis. © 2013 The Authors. Microbiology Open published by John Wiley & Sons Ltd.

  12. CysK Plays a Role in Biofilm Formation and Colonization by Vibrio fischeri.

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    Singh, Priyanka; Brooks, John F; Ray, Valerie A; Mandel, Mark J; Visick, Karen L

    2015-08-01

    A biofilm, or a matrix-embedded community of cells, promotes the ability of the bacterium Vibrio fischeri to colonize its symbiotic host, the Hawaiian squid Euprymna scolopes. Biofilm formation and colonization depend on syp, an 18-gene polysaccharide locus. To identify other genes necessary for biofilm formation, we screened for mutants that failed to form wrinkled colonies, a type of biofilm. We obtained several with defects in genes required for cysteine metabolism, including cysH, cysJ, cysK, and cysN. The cysK mutant exhibited the most severe wrinkling defect. It could be complemented with a wild-type copy of the cysK gene, which encodes O-acetylserine sulfhydrolase, or by supplementing the medium with additional cysteine. None of a number of other mutants defective for biosynthetic genes negatively impacted wrinkled colony formation, suggesting a specific role for CysK. CysK did not appear to control activation of Syp regulators or transcription of the syp locus, but it did influence production of the Syp polysaccharide. Under biofilm-inducing conditions, the cysK mutant retained the same ability as that of the parent strain to adhere to the agar surface. The cysK mutant also exhibited a defect in pellicle production that could be complemented by the cysK gene but not by cysteine, suggesting that, under these conditions, CysK is important for more than the production of cysteine. Finally, our data reveal a role for cysK in symbiotic colonization by V. fischeri. Although many questions remain, this work provides insights into additional factors required for biofilm formation and colonization by V. fischeri. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Modeling Analysis of Signal Sensitivity and Specificity by Vibrio fischeri LuxR Variants.

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    Deanna M Colton

    Full Text Available The LuxR protein of the bacterium Vibrio fischeri belongs to a family of transcriptional activators that underlie pheromone-mediated signaling by responding to acyl-homoserine lactones (-HSLs or related molecules. V. fischeri produces two acyl-HSLs, N-3-oxo-hexanoyl-HSL (3OC6-HSL and N-octanoyl-HSL (C8-HSL, each of which interact with LuxR to facilitate its binding to a "lux box" DNA sequence, thereby enabling LuxR to activate transcription of the lux operon responsible for bioluminescence. We have investigated the HSL sensitivity of four different variants of V. fischeri LuxR: two derived from wild-type strains ES114 and MJ1, and two derivatives of LuxRMJ1 generated by directed evolution. For each LuxR variant, we measured the bioluminescence induced by combinations of C8-HSL and 3OC6-HSL. We fit these data to a model in which the two HSLs compete with each other to form multimeric LuxR complexes that directly interact with lux to activate bioluminescence. The model reproduces the observed effects of HSL combinations on the bioluminescence responses directed by LuxR variants, including competition and non-monotonic responses to C8-HSL and 3OC6-HSL. The analysis yields robust estimates for the underlying dissociation constants and cooperativities (Hill coefficients of the LuxR-HSL complexes and their affinities for the lux box. It also reveals significant differences in the affinities of LuxRMJ1 and LuxRES114 for 3OC6-HSL. Further, LuxRMJ1 and LuxRES114 differed sharply from LuxRs retrieved by directed evolution in the cooperativity of LuxR-HSL complex formation and the affinity of these complexes for lux. These results show how computational modeling of in vivo experimental data can provide insight into the mechanistic consequences of directed evolution.

  14. Modeling Analysis of Signal Sensitivity and Specificity by Vibrio fischeri LuxR Variants.

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    Colton, Deanna M; Stabb, Eric V; Hagen, Stephen J

    2015-01-01

    The LuxR protein of the bacterium Vibrio fischeri belongs to a family of transcriptional activators that underlie pheromone-mediated signaling by responding to acyl-homoserine lactones (-HSLs) or related molecules. V. fischeri produces two acyl-HSLs, N-3-oxo-hexanoyl-HSL (3OC6-HSL) and N-octanoyl-HSL (C8-HSL), each of which interact with LuxR to facilitate its binding to a "lux box" DNA sequence, thereby enabling LuxR to activate transcription of the lux operon responsible for bioluminescence. We have investigated the HSL sensitivity of four different variants of V. fischeri LuxR: two derived from wild-type strains ES114 and MJ1, and two derivatives of LuxRMJ1 generated by directed evolution. For each LuxR variant, we measured the bioluminescence induced by combinations of C8-HSL and 3OC6-HSL. We fit these data to a model in which the two HSLs compete with each other to form multimeric LuxR complexes that directly interact with lux to activate bioluminescence. The model reproduces the observed effects of HSL combinations on the bioluminescence responses directed by LuxR variants, including competition and non-monotonic responses to C8-HSL and 3OC6-HSL. The analysis yields robust estimates for the underlying dissociation constants and cooperativities (Hill coefficients) of the LuxR-HSL complexes and their affinities for the lux box. It also reveals significant differences in the affinities of LuxRMJ1 and LuxRES114 for 3OC6-HSL. Further, LuxRMJ1 and LuxRES114 differed sharply from LuxRs retrieved by directed evolution in the cooperativity of LuxR-HSL complex formation and the affinity of these complexes for lux. These results show how computational modeling of in vivo experimental data can provide insight into the mechanistic consequences of directed evolution.

  15. Cyclic AMP receptor protein regulates pheromone-mediated bioluminescence at multiple levels in Vibrio fischeri ES114.

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    Lyell, Noreen L; Colton, Deanna M; Bose, Jeffrey L; Tumen-Velasquez, Melissa P; Kimbrough, John H; Stabb, Eric V

    2013-11-01

    Bioluminescence in Vibrio fischeri ES114 is activated by autoinducer pheromones, and this regulation serves as a model for bacterial cell-cell signaling. As in other bacteria, pheromone concentration increases with cell density; however, pheromone synthesis and perception are also modulated in response to environmental stimuli. Previous studies suggested that expression of the pheromone-dependent bioluminescence activator LuxR is regulated in response to glucose by cyclic AMP (cAMP) receptor protein (CRP) (P. V. Dunlap and E. P. Greenberg, J. Bacteriol. 164:45-50, 1985; P. V. Dunlap and E. P. Greenberg, J. Bacteriol. 170:4040-4046, 1988; P. V. Dunlap, J. Bacteriol. 171:1199-1202, 1989; and W. F. Friedrich and E. P. Greenberg, Arch. Microbiol. 134:87-91, 1983). Consistent with this model, we found that bioluminescence in V. fischeri ES114 is modulated by glucose and stimulated by cAMP. In addition, a Δcrp mutant was ∼100-fold dimmer than ES114 and did not increase luminescence in response to added cAMP, even though cells lacking crp were still metabolically capable of producing luminescence. We further discovered that CRP regulates not only luxR but also the alternative pheromone synthase gene ainS. We found that His-tagged V. fischeri CRP could bind sequences upstream of both luxR and ainS, supporting bioinformatic predictions of direct regulation at both promoters. Luminescence increased in response to cAMP if either the ainS or luxR system was under native regulation, suggesting cAMP-CRP significantly increases luminescence through both systems. Finally, using transcriptional reporters in transgenic Escherichia coli, we elucidated two additional regulatory connections. First, LuxR-independent basal transcription of the luxI promoter was enhanced by CRP. Second, the effect of CRP on the ainS promoter depended on whether the V. fischeri regulatory gene litR was also introduced. These results suggest an integral role for CRP in pheromone signaling that goes

  16. Implications of handling practices on the ecotoxic profile of alumina nanoparticles towards the bacteria Vibrio fischeri.

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    Tsiridis, Vasilios; Petala, Maria; Koukiotis, Chris; Darakas, Efthymios

    2017-01-02

    The complex nature and behavior of Engineered Nanomaterials (ENMs) has led to adoption of customized experimental ecotoxicity practices that are prone to possible artefacts in the inherent toxic properties of ENMs. In addition, the lack of standardized handling procedures for the ecotoxicity testing of ENMs prevents the development of experimental protocols for regulatory purposes. In this study, a suite of techniques for dispersion of ENMs was adopted and tested for two types of surface-modified alumina nanoparticles-one hydrophobic and one hydrophilic-towards the bacteria, Vibrio fischeri. The effect of certain handling practices on the observed ecotoxic effects on V. fischeri was examined. The overall goal was to evaluate by what means the handling practices of ENMs may affect the obtained toxicity results. It was realized that the toxicity of the hydrophilic and hydrophobic ENMs was mainly affected by the centrifugation and the salinity of the tested dispersions, respectively. It is more likely that both aluminium and coating substance contributed to the overall toxicity. Toxicity results are discussed with regard to generic physicochemical characteristics of the dispersions.

  17. Identification of a novel matrix protein that promotes biofilm maturation in Vibrio fischeri.

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    Ray, Valerie A; Driks, Adam; Visick, Karen L

    2015-02-01

    Bacteria form communities, termed biofilms, in which cells adhere to each other within a matrix, typically comprised of polysaccharides, proteins, and extracellular DNA. Biofilm formation by the marine bacterium Vibrio fischeri requires the Syp polysaccharide, but the involvement of matrix proteins is as yet unknown. Here we identified three genes, termed bmpA, -B, and -C (biofilm maturation protein), with overlapping functions in biofilm maturation. A triple bmpABC mutant, but not single or double mutants, was defective in producing wrinkled colonies, a form of biofilm. Surprisingly, the triple mutant was competent to form pellicles, another biofilm phenotype, but they generally lacked a three-dimensional architecture. Transmission electron microscopy revealed that the extracellular matrix of the bmp mutant contained electron-dense, thread-like structures that were also present in the wild type but lacking in syp mutant strains. We hypothesized that the bmp mutant produces the Syp polysaccharide but fails to produce/export a distinct matrix component. Indeed, a mixture of the bmp and syp mutants produced a wrinkled colony. Finally, BmpA could be detected in cell-free supernatants from disrupted pellicles. Thus, this work identifies a new matrix protein necessary for biofilm maturation by V. fischeri and, based on the conservation of bmp, potentially other microbes. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  18. The first engagement of partners in the Euprymna scolopes-Vibrio fischeri symbiosis is a two-step process initiated by a few environmental symbiont cells.

    Science.gov (United States)

    Altura, Melissa A; Heath-Heckman, Elizabeth A C; Gillette, Amani; Kremer, Natacha; Krachler, Anne-Marie; Brennan, Caitlin; Ruby, Edward G; Orth, Kim; McFall-Ngai, Margaret J

    2013-11-01

    We studied the Euprymna scolopes-Vibrio fischeri symbiosis to characterize, in vivo and in real time, the transition between the bacterial partner's free-living and symbiotic life styles. Previous studies using high inocula demonstrated that environmental V. fischeri cells aggregate during a 3 h period in host-shed mucus along the light organ's superficial ciliated epithelia. Under lower inoculum conditions, similar to the levels of symbiont cells in the environment, this interaction induces haemocyte trafficking into these tissues. Here, in experiments simulating natural conditions, microscopy revealed that at 3 h following first exposure, only ∼ 5 V. fischeri cells aggregated on the organ surface. These cells associated with host cilia and induced haemocyte trafficking. Symbiont viability was essential and mutants defective in symbiosis initiation and/or production of certain surface features, including the Mam7 protein, which is implicated in host cell attachment of V. cholerae, associated normally with host cilia. Studies with exopolysaccharide mutants, which are defective in aggregation, suggest a two-step process of V. fischeri cell engagement: association with host cilia followed by aggregation, i.e. host cell-symbiont interaction with subsequent symbiont-symbiont cell interaction. Taken together, these data provide a new model of early partner engagement, a complex model of host-symbiont interaction with exquisite sensitivity. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Proteomic and metabolomic profiles demonstrate variation among free-living and symbiotic vibrio fischeri biofilms.

    Science.gov (United States)

    Chavez-Dozal, Alba; Gorman, Clayton; Nishiguchi, Michele K

    2015-10-23

    A number of bacterial species are capable of growing in various life history modes that enable their survival and persistence in both planktonic free-living stages as well as in biofilm communities. Mechanisms contributing to either planktonic cell or biofilm persistence and survival can be carefully delineated using multiple differential techniques (e.g., genomics and transcriptomics). In this study, we present both proteomic and metabolomic analyses of Vibrio fischeri biofilms, demonstrating the potential for combined differential studies for elucidating life-history switches important for establishing the mutualism through biofilm formation and host colonization. The study used a metabolomics/proteomics or "meta-proteomics" approach, referring to the combined protein and metabolic data analysis that bridges the gap between phenotypic changes (planktonic cell to biofilm formation) with genotypic changes (reflected in protein/metabolic profiles). Our methods used protein shotgun construction, followed by liquid chromatography coupled with mass spectrometry (LC-MS) detection and quantification for both free-living and biofilm forming V. fischeri. We present a time-resolved picture of approximately 100 proteins (2D-PAGE and shotgun proteomics) and 200 metabolites that are present during the transition from planktonic growth to community biofilm formation. Proteins involved in stress response, DNA repair damage, and transport appeared to be highly expressed during the biofilm state. In addition, metabolites detected in biofilms correspond to components of the exopolysaccharide (EPS) matrix (sugars and glycerol-derived). Alterations in metabolic enzymes were paralleled by more pronounced changes in concentration of intermediates from the glycolysis pathway as well as several amino acids. This combined analysis of both types of information (proteins, metabolites) has provided a more complete picture of the biochemical processes of biofilm formation and what determines

  20. The haem-uptake gene cluster in Vibrio fischeri is regulated by Fur and contributes to symbiotic colonization.

    Science.gov (United States)

    Septer, Alecia N; Wang, Yanling; Ruby, Edward G; Stabb, Eric V; Dunn, Anne K

    2011-11-01

    Although it is accepted that bacteria-colonizing host tissues are commonly faced with iron-limiting conditions and that pathogenic bacteria often utilize iron from host-derived haem-based compounds, the mechanisms of iron acquisition by beneficial symbiotic bacteria are less clear. The bacterium Vibrio fischeri mutualistically colonizes the light organ of the squid Euprymna scolopes. Genome sequence analysis of V. fischeri revealed a putative haem-uptake gene cluster, and through mutant analysis we confirmed this cluster is important for haemin use by V. fischeri in culture. LacZ reporter assays demonstrated Fur-dependent transcriptional regulation of cluster promoter activity in culture. GFP-based reporter assays revealed that gene cluster promoter activity is induced in symbiotic V. fischeri as early as 14 h post inoculation, although colonization assays with the haem uptake mutant suggested an inability to uptake haem does not begin to limit colonization until later stages of the symbiosis. Our data indicate that the squid light organ is a low iron environment and that haem-based sources of iron are used by symbiotic V. fischeri cells. These findings provide important additional information on the availability of iron during symbiotic colonization of E. scolopes by V. fischeri, as well as the role of haem uptake in non-pathogenic host-microbe interactions. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  1. Characterization of htrB and msbB mutants of the light organ symbiont Vibrio fischeri.

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    Adin, Dawn M; Phillips, Nancy J; Gibson, Bradford W; Apicella, Michael A; Ruby, Edward G; McFall-Ngai, Margaret J; Hall, Daniel B; Stabb, Eric V

    2008-02-01

    Bacterial lipid A is an important mediator of bacterium-host interactions, and secondary acylations added by HtrB and MsbB can be critical for colonization and virulence in pathogenic infections. In contrast, Vibrio fischeri lipid A stimulates normal developmental processes in this bacterium's mutualistic host, Euprymna scolopes, although the importance of lipid A structure in this symbiosis is unknown. To further examine V. fischeri lipid A and its symbiotic function, we identified two paralogs of htrB (designated htrB1 and htrB2) and an msbB gene in V. fischeri ES114 and demonstrated that these genes encode lipid A secondary acyltransferases. htrB2 and msbB are found on the Vibrio "housekeeping" chromosome 1 and are conserved in other Vibrio species. Mutations in htrB2 and msbB did not impair symbiotic colonization but resulted in phenotypic alterations in culture, including reduced motility and increased luminescence. These mutations also affected sensitivity to sodium dodecyl sulfate, kanamycin, and polymyxin, consistent with changes in membrane permeability. Conversely, htrB1 is located on the smaller, more variable vibrio chromosome 2, and an htrB1 mutant was wild-type-like in culture but appeared attenuated in initiating the symbiosis and was outcompeted 2.7-fold during colonization when mixed with the parent. These data suggest that htrB2 and msbB play conserved general roles in vibrio biology, whereas htrB1 plays a more symbiosis-specific role in V. fischeri.

  2. Noise and crosstalk in two quorum-sensing inputs of Vibrio fischeri.

    Science.gov (United States)

    Pérez, Pablo D; Weiss, Joel T; Hagen, Stephen J

    2011-09-29

    One of the puzzles in bacterial quorum sensing is understanding how an organism integrates the information gained from multiple input signals. The marine bacterium Vibrio fischeri regulates its bioluminescence through a quorum sensing mechanism that receives input from three pheromone signals, including two acyl homoserine lactone (HSL) signals. While the role of the 3-oxo-C6 homoserine lactone (3OC6HSL) signal in activating the lux genes has been extensively studied and modeled, the role of the C8 homoserine lactone (C8HSL) is less obvious, as it can either activate luminescence or block its activation. It remains unclear how crosstalk between C8HSL and 3OC6HSL affects the information that the bacterium obtains through quorum sensing. We have used microfluidic methods to measure the response of individual V.fischeri cells to combinations of C8HSL and 3OC6HSL. By measuring the fluorescence of individual V.fischeri cells containing a chromosomal gfp-reporter for the lux genes, we study how combinations of exogenous HSLs affect both the population average and the cell-to-cell variability of lux activation levels. At the level of a population average, the crosstalk between the C8HSL and 3OC6HSL inputs is well-described by a competitive inhibition model. At the level of individual cells, the heterogeneity in the lux response depends only on the average degree of activation, so that the noise in the output is not reduced by the presence of the second HSL signal. Overall we find that the mutual information between the signal inputs and the lux output is less than one bit. A nonlinear correlation between fluorescence and bioluminescence outputs from lux leads to different noise properties for these reporters. The lux genes in V.fischeri do not appear to distinguish between the two HSL inputs, and even with two signal inputs the regulation of lux is extremely noisy. Hence the role of crosstalk from the C8HSL input may not be to improve sensing precision, but rather to

  3. Noise and crosstalk in two quorum-sensing inputs of Vibrio fischeri

    Directory of Open Access Journals (Sweden)

    Weiss Joel T

    2011-09-01

    Full Text Available Abstract Background One of the puzzles in bacterial quorum sensing is understanding how an organism integrates the information gained from multiple input signals. The marine bacterium Vibrio fischeri regulates its bioluminescence through a quorum sensing mechanism that receives input from three pheromone signals, including two acyl homoserine lactone (HSL signals. While the role of the 3-oxo-C6 homoserine lactone (3OC6HSL signal in activating the lux genes has been extensively studied and modeled, the role of the C8 homoserine lactone (C8HSL is less obvious, as it can either activate luminescence or block its activation. It remains unclear how crosstalk between C8HSL and 3OC6HSL affects the information that the bacterium obtains through quorum sensing. Results We have used microfluidic methods to measure the response of individual V.fischeri cells to combinations of C8HSL and 3OC6HSL. By measuring the fluorescence of individual V.fischeri cells containing a chromosomal gfp-reporter for the lux genes, we study how combinations of exogenous HSLs affect both the population average and the cell-to-cell variability of lux activation levels. At the level of a population average, the crosstalk between the C8HSL and 3OC6HSL inputs is well-described by a competitive inhibition model. At the level of individual cells, the heterogeneity in the lux response depends only on the average degree of activation, so that the noise in the output is not reduced by the presence of the second HSL signal. Overall we find that the mutual information between the signal inputs and the lux output is less than one bit. A nonlinear correlation between fluorescence and bioluminescence outputs from lux leads to different noise properties for these reporters. Conclusions The lux genes in V.fischeri do not appear to distinguish between the two HSL inputs, and even with two signal inputs the regulation of lux is extremely noisy. Hence the role of crosstalk from the C8HSL input

  4. Topological study on the toxicity of ionic liquids on Vibrio fischeri by the quantitative structure-activity relationship method.

    Science.gov (United States)

    Yan, Fangyou; Shang, Qiaoyan; Xia, Shuqian; Wang, Qiang; Ma, Peisheng

    2015-04-09

    As environmentally friendly solvents, ionic liquids (ILs) are unlikely to act as air contaminants or inhalation toxins resulting from their negligible vapor pressure and excellent thermal stability. However, they can be potential water contaminants because of their considerable solubility in water; therefore, a proper toxicological assessment of ILs is essential. The environmental fate of ILs is studied by quantitative structure-activity relationship (QSAR) method. A multiple linear regression (MLR) model is obtained by topological method using toxicity data of 157 ILs on Vibrio fischeri, which are composed of 74 cations and 22 anions. The topological index developed in our research group is used for predicting the V. fischeri toxicity for the first time. The MLR model is precise for estimating LogEC50 of ILs on V. fischeri with square of correlation coefficient (R(2)) = 0.908 and the average absolute error (AAE) = 0.278. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. O-antigen and core carbohydrate of Vibrio fischeri lipopolysaccharide: composition and analysis of their role in Euprymna scolopes light organ colonization.

    Science.gov (United States)

    Post, Deborah M B; Yu, Liping; Krasity, Benjamin C; Choudhury, Biswa; Mandel, Mark J; Brennan, Caitlin A; Ruby, Edward G; McFall-Ngai, Margaret J; Gibson, Bradford W; Apicella, Michael A

    2012-03-09

    Vibrio fischeri exists in a symbiotic relationship with the Hawaiian bobtail squid, Euprymna scolopes, where the squid provides a home for the bacteria, and the bacteria in turn provide camouflage that helps protect the squid from night-time predators. Like other gram-negative organisms, V. fischeri expresses lipopolysaccharide (LPS) on its cell surface. The structure of the O-antigen and the core components of the LPS and their possible role in colonization of the squid have not previously been determined. In these studies, an O-antigen ligase mutant, waaL, was utilized to determine the structures of these LPS components and their roles in colonization of the squid. WaaL ligates the O-antigen to the core of the LPS; thus, LPS from waaL mutants lacks O-antigen. Our results show that the V. fischeri waaL mutant has a motility defect, is significantly delayed in colonization, and is unable to compete with the wild-type strain in co-colonization assays. Comparative analyses of the LPS from the wild-type and waaL strains showed that the V. fischeri LPS has a single O-antigen repeat composed of yersiniose, 8-epi-legionaminic acid, and N-acetylfucosamine. In addition, the LPS from the waaL strain showed that the core structure consists of L-glycero-D-manno-heptose, D-glycero-D-manno-heptose, glucose, 3-deoxy-D-manno-octulosonic acid, N-acetylgalactosamine, 8-epi-legionaminic acid, phosphate, and phosphoethanolamine. These studies indicate that the unusual V. fischeri O-antigen sugars play a role in the early phases of bacterial colonization of the squid.

  6. Requirements for sulfur in cell density-independent induction of luminescence in Vibrio fischeri under nutrient-starved conditions.

    Science.gov (United States)

    Tabei, Yosuke; Era, Mariko; Ogawa, Akane; Morita, Hiroshi

    2012-04-01

    Despite the universal requirement for sulfur in living organisms, it is not known whether the luminescence of Vibrio fischeri is sulfur-dependent and how sulfur affects the intensity of its luminescence. In this study, we investigated the requirement for sulfur in V. fischeri luminescence under nutrient-starved conditions. Full induction of V. fischeri luminescence required MgSO(4); in artificial seawater cultures that lacked sufficient MgSO(4), its luminescence was not fully induced. This induction of luminescence was not dependent on autoinduction because the cell density of V. fischeri did not reach the critical threshold concentration. In addition to MgSO(4), this cell density-independent luminescence was induced or maintained by nontoxic concentrations of l-cysteine, sulfate, sulfite, and thiosulfate. Moreover, the addition of N -3-oxo-hexanoyl homoserine lactone and N -octanoyl homoserine lactone, which are known autoinducers in V. fischeri, did not induce luminescence under these conditions. This result suggested that the underlying mechanism of luminescence may be different from the known autoinduction mechanism. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Oil effect in freshly spiked marine sediment on Vibrio fischeri, Corophium volutator, and Echinocardium cordatum.

    Science.gov (United States)

    Brils, Jos M; Huwer, Sherri L; Kater, Belinda J; Schout, Peter G; Harmsen, Joop; Delvigne, Gerard A L; Scholten, Martin C Th

    2002-10-01

    The purpose of this study was to provide data to be used in The Netherlands for development of ecotoxicologically based quality criteria for oil-contaminated sediments and dredged material. In addition, the relation of toxicity to specific oil boiling-point fraction ranges was explored. Natural marine sediment, with a moisture, organic carbon, and silt content of approximately 80, 1.8, and 33% of the dry weight, respectively, was artificially spiked using a spiking method developed in this project. Aliquots of one part of the sediment were spiked to several concentrations of Gulf distillate marine grade A (DMA) gasoil (containing 64% C10-19) and aliquots of the other part to several concentrations of Gulf high viscosity grade 46 (HV46) hydraulic oil (containing 99.2% C19-40). Thus, for each individual oil type, a concentration series was created. Vibrio fischeri (endpoint: bioluminescence inhibition), Corophium volutator (endpoint:mortality), and Echinocardium cordatum (endpoint:mortality) were exposed to these spiked sediments for 10 min, 10 d and 14 d, respectively. Based on the test results, the effective concentration on 50% of the test animals was statistically estimated. For DMA gasoil and HV46 hydraulic oil, respectively, the effective concentrations were 43.7 and 2,682 mg/kg dry weight for V. fischeri, 100 and 9,138 mg/kg dry weight for C. volutator, 190, and 1064 mg/kg dry weight for E. cordatum. This study shows that the toxicity is strongly correlated with the lower boiling-point fractions and especially to those within the C10-C19 range.

  8. Reduction of acute toxicity of the pharmaceutical fluoxetine (Prozac) submitted to ionizing radiation to Vibrio fischeri

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Dymes R.A.; Garcia, Vanessa S.G.; Vilarrubia, Anna C.S.; Borrely, Sueli I., E-mail: vanessagarcia@usp.br, E-mail: sborrely@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The constant use of pharmaceutical drugs by great part of the population and its continuous input into the environment creates a growing need of investigating its presence, behavior and the effects on aquatic biota, as well as new ways to treat wastewater containing such substances. The fluoxetine hydrochloride (FH) present in the drug Prozac is an active ingredient used in the treatment of depressive and anxiety disorders. Generally, these compounds enter the aquatic environment by sewage collectors systems after undergoing prior treatment in sewage treatment plants (STPs) or without any treatment. This study focused on evaluating the reduction of acute toxicity of the pharmaceutical FH, under its manipulated formula, for the marine bacterium Vibrio fischeri. It was also evaluated the acute toxicity of the aqueous solution containing the FH after its exposition to ionizing radiation from industrial electron accelerator. It was performed acute toxicity tests lasting 15 minutes, where the average EC (50) of the non-irradiated CF water solution was approximately 0.68 mg L-1. While the CF water solution irradiated with 1 kGy, 2.5 kGy, 7.5 kGy and 10 kGy, presented an average EC(50) 1.63 mg.L{sup -1}, 2.34 mg.L{sup -1}, 2.35 mg.L{sup -1} and 1.80 mg.L{sup -1}, respectively, showing a notable reduction of the acute toxicity for this organism. (author)

  9. How the structure of ionic liquid affects its toxicity to Vibrio fischeri?

    Science.gov (United States)

    Grzonkowska, Monika; Sosnowska, Anita; Barycki, Maciej; Rybinska, Anna; Puzyn, Tomasz

    2016-09-01

    In the present work, we have proposed a statistical model predicting the toxicity of ionic liquids (ILs) to Vibrio fischeri bacteria using the Quantitative Structure-Activity Relationships (QSAR) method. The model was developed with Multiple Linear Regression (MLR) technique, using the Gutman molecular topological index (GMTI), the lopping centric information index (LOC) and the number of oxygen atoms. Presented model is characterized by the good fit to the experimental data (R(2) = 0.78), high robustness (Q(2)CV = 0.72) and good predictive ability (Q(2)EXT = 0.75). This approach, with using very simple descriptors, helps to initially evaluate the toxicity of newly designed ionic liquids. The studied toxicity of ionic liquids depends mainly on their cations' structure: larger, more branched cations with long alkyl chains are more toxic than the smaller, linear ones. The presence of polar functional groups in the cation's structure reduces the toxic properties of ionic liquids. The structure of the anion has little effect on the toxicity of the studied ionic liquids. Obtained results will provide insight into the toxicity mechanisms and useful information for assessing the potential ecological risk of ionic liquids. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Engineering Vibrio fischeri transcriptional activator LuxR for diverse transcriptional activities.

    Science.gov (United States)

    Lu, Yang

    2016-09-01

    To alter DNA binding specificity of Vibrio fischeri LuxR and to expand the toolbox for constructing synthetic networks. A mutation library (about 10,000 individuals) of the DNA binding domain of LuxR were generated. A genetic selection was performed to obtain LuxR mutants that recognize three lux box DNA variants that are not recognized by wild-type LuxR. Six LuxR mutants were identified. The evolved LuxR mutants were further characterized by measuring the transcriptional activities of different combinations of LuxR mutants and lux box variants. Varied transcriptional activities were found in these LuxR-lux box pairs. The background expressions of the evolved LuxR-lux box systems are more tightly regulated than the wild-type LuxR-lux box system. The LuxR transcriptional system was evolved to recognize three lux box DNAs which are not recognized by wild-type LuxR.

  11. Directed evolution of the autoinducer selectivity of Vibrio fischeri LuxR.

    Science.gov (United States)

    Tashiro, Yohei; Kimura, Yuki; Furubayashi, Maiko; Tanaka, Akira; Terakubo, Kei; Saito, Kyoichi; Kawai-Noma, Shigeko; Umeno, Daisuke

    2016-11-25

    LuxR family transcriptional regulators are the core components of quorum sensing in Gram-negative bacteria and exert their effects through binding to the signaling molecules acyl-homoserine lactones (acyl-HSLs). The function of the LuxR homologs is remarkably plastic, and naturally occurring acyl-HSLs are structurally diverse. To investigate the molecular basis of the functional plasticity of Vibrio fischeri LuxR, we directed the evolution of LuxR toward three different specificities in the laboratory. We found an orthogonal pair of LuxR mutants specific either to 3-oxo-hexanoyl homoserine lactone or to 3-oxo-octanoyl homoserine lactone. Interestingly, the majority of the specificity changes did not arise from modulating the recognition event but rather from changing the efficiency of the transition from the inactive form to the active form upon signal binding. This finding explains how quorum sensing systems can rapidly diverge in nature and in the laboratory and how signal orthogonality and mutual inhibition frequently occur among closely related diverging systems.

  12. Assessment of heavy metals bioavailability and toxicity toward Vibrio fischeri in sediment of the Huelva estuary.

    Science.gov (United States)

    Rosado, Daniel; Usero, José; Morillo, José

    2016-06-01

    Relationship between toxicity and bioavailable metals in sediments from the Huelva estuary and its littoral of influence was analyzed. Toxicity was assessed with Microtox® bioassay using a marine luminescent bacterium: Vibrio fischeri. Bioavailable metals were considered as both, acid extractable fraction of BCR procedure and the sum of exchangeable and bound to carbonates fractions of Tessier sequential extraction. A bioavailable metals index was calculated to integrate results in a single figure. Toxicity and bioavailable metals showed a similar pattern. Higher levels were found in the estuary than in the littoral (140 TU/g). In Huelva estuary, highest levels were found in the Tinto estuary (5725 TU/g), followed by the Odiel estuary (5100 TU/g) and the Padre Santo Canal (2500 TU/g). Results in this area were well over than those in nearby estuaries. Furthermore, they are similar to or even higher than those in other polluted sediments around the world. Bioavailable metal index showed a stronger correlation with acid extractable fraction of BCR (R(2) = 0.704) than that for the sum of exchangeable and bound to carbonates fractions of Tessier (R(2) = 0.661). These results suggest that bioavailable metals are an important source of sediment toxicity in the Huelva estuary and its littoral of influence, an area with one of the highest mortality risks of Spain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Development of QSAR model to predict the ecotoxicity of Vibrio fischeri using COSMO-RS descriptors.

    Science.gov (United States)

    Ghanem, Ouahid Ben; Mutalib, M I Abdul; Lévêque, Jean-Marc; El-Harbawi, Mohanad

    2017-03-01

    Ionic liquids (ILs) are class of solvent whose properties can be modified and tuned to meet industrial requirements. However, a high number of potentially available cations and anions leads to an even increasing members of newly-synthesized ionic liquids, adding to the complexity of understanding on their impact on aquatic organisms. Quantitative structure activity∖property relationship (QSAR∖QSPR) technique has been proven to be a useful method for toxicity prediction. In this work,σ-profile descriptors were used to build linear and non-linear QSAR models to predict the ecotoxicities of a wide variety of ILs towards bioluminescent bacterium Vibrio fischeri. Linear model was constructed using five descriptors resulting in high accuracy prediction of 0.906. The model performance and stability were ascertained using k-fold cross validation method. The selected descriptors set from the linear model was then used in multilayer perceptron (MLP) technique to develop the non-linear model, the accuracy of the model was further enhanced achieving high correlation coefficient with the lowest value being 0.961 with the highest mean square error of 0.157. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. FNR-mediated regulation of bioluminescence and anaerobic respiration in the light-organ symbiont Vibrio fischeri.

    Science.gov (United States)

    Septer, Alecia N; Bose, Jeffrey L; Dunn, Anne K; Stabb, Eric V

    2010-05-01

    Vibrio fischeri induces both anaerobic respiration and bioluminescence during symbiotic infection. In many bacteria, the oxygen-sensitive regulator FNR activates anaerobic respiration, and a preliminary study using the light-generating lux genes from V. fischeri MJ1 cloned in Escherichia coli suggested that FNR stimulates bioluminescence. To test for FNR-mediated regulation of bioluminescence and anaerobic respiration in V. fischeri, we generated fnr mutants of V. fischeri strains MJ1 and ES114. In both strains, FNR was required for normal fumarate- and nitrate-dependent respiration. However, contrary to the report in transgenic E. coli, FNR mediated the repression of lux. ArcA represses bioluminescence, and P(arcA)-lacZ reporters showed reduced expression in fnr mutants, suggesting a possible indirect effect of FNR on bioluminescence via arcA. Finally, the fnr mutant of ES114 was not impaired in colonization of its host squid, Euprymna scolopes. This study extends the characterization of FNR to the Vibrionaceae and underscores the importance of studying lux regulation in its native background.

  15. Influence of Select Antibiotics on Vibrio fischeri and Desmodesmus subspicatus at μg L-1 Concentrations.

    Science.gov (United States)

    de Vasconcelos, E C; Dalke, C R; de Oliveira, C M R

    2017-07-01

    The presence of pharmaceuticals in the aquatic environment is a contemporary reality and it is necessary to understand more about the effects of this presence on organisms. The purpose of this work was to assess the ecotoxicity of antibiotics metronidazole, nitrofurantoin, trimethoprim, and sulphamethoxazole (single and mixture) in Vibrio fischeri and Desmodesmus subspicatus at μg L-1 concentrations. The evaluation of the toxic effect of the antibiotics on V. fischeri and D. subspicatus was based on fluorescence and bioluminescence tests, respectively, using nominal concentrations. When tested individually, the four antibiotics gave rise to a toxic effect on the evaluated organisms. Sulphamethoxazole caused a higher toxic effect on V. fischeri and D. subspicatus from 7.81 to 500 μg L-1. Trimethoprim and sulphamethoxazole showed hormesis for the concentrations, which ranged from 7.81 to 62.5 μg L-1. The mixture of antibiotics induced a toxic effect on the V. fischeri and D. subspicatus organisms (from 0.03 to 1 μg L-1 concentrations) than when the antibiotics were evaluated individually. These results were significant since water quality problems are widespread all over the word, and emerging pollutants such as antibiotics have been detected in the aquatic environment in very low concentrations.

  16. FNR-mediated regulation of bioluminescence and anaerobic respiration in the light-organ symbiont Vibrio fischeri

    Science.gov (United States)

    Septer, Alecia N.; Bose, Jeffrey L.; Dunn, Anne K.; Stabb, Eric V.

    2010-01-01

    Vibrio fischeri induces both anaerobic respiration and bioluminescence during symbiotic infection. In many bacteria, the oxygen-sensitive regulator FNR activates anaerobic respiration, and a preliminary study using the light-generating lux genes from V. fischeri MJ1 cloned in Escherichia coli suggested that FNR stimulates bioluminescence. To test for FNR-mediated regulation of bioluminescence and anaerobic respiration in V. fischeri, we generated fnr mutants of V. fischeri strains MJ1 and ES114. In both strains, FNR was required for normal fumarate- and nitrate-dependent respiration. However, contrary to the report in transgenic E. coli, FNR mediated repression of lux. ArcA represses bioluminescence, and ParcA-lacZ reporters showed reduced expression in fnr mutants, suggesting a possible indirect effect of FNR on bioluminescence via arcA. Finally, the fnr mutant of ES114 was not impaired in colonization of its host squid, Euprymna scolopes. This study extends characterization of FNR to the Vibrionaceae and underscores the importance of studying lux regulation in its native background. PMID:20298504

  17. Quorum Sensing Signal Synthesis May Represent a Selective Advantage Independent of Its Role in Regulation of Bioluminescence in Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Grace Chong

    Full Text Available The evolution of biological signalling systems and apparently altruistic or cooperative traits in diverse organisms has required selection against the subversive tendencies of self-interested biological entities. The bacterial signalling and response system known as quorum sensing or Acylated Homoserine Lactone (AHL mediated gene expression is thought to have evolved through kin selection. In this in vitro study on the model quorum sensing bioluminescent marine symbiont Vibrio fischeri, competition and long-term sub culturing experiments suggest that selection for AHL synthesis (encoded by the AHL synthase gene luxI is independent of the quorum sensing regulated phenotype (bioluminescence encoded by luxCDABE. Whilst results support the hypothesis that signal response (AHL binding and transcriptional activation encoded by the luxR gene is maintained through indirect fitness benefits (kin selection, signal synthesis is maintained in the V. fischeri genome over evolutionary time through direct fitness benefits at the individual level from an unknown function.

  18. The periplasmic sensing domain of Vibrio fischeri chemoreceptor protein A (VfcA): cloning, purification and crystallographic analysis.

    Science.gov (United States)

    Salah Ud-Din, Abu Iftiaf Md; Roujeinikova, Anna

    2016-05-01

    Flagella-mediated motility and chemotaxis towards nutrients are important characteristics of Vibrio fischeri that play a crucial role in the development of its symbiotic relationship with its Hawaiian squid host Euprymna scolopes. The V. fischeri chemoreceptor A (VfcA) mediates chemotaxis toward amino acids. The periplasmic sensory domain of VfcA has been crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol 3350 as a precipitating agent. The crystals belonged to space group P1, with unit-cell parameters a = 39.9, b = 57.0, c = 117.0 Å, α = 88.9, β = 80.5, γ = 89.7°. A complete X-ray diffraction data set has been collected to 1.8 Å resolution using cryocooling conditions and synchrotron radiation.

  19. Quorum Sensing Signal Synthesis May Represent a Selective Advantage Independent of Its Role in Regulation of Bioluminescence in Vibrio fischeri

    Science.gov (United States)

    Chong, Grace; Kimyon, Önder; Manefield, Mike

    2013-01-01

    The evolution of biological signalling systems and apparently altruistic or cooperative traits in diverse organisms has required selection against the subversive tendencies of self-interested biological entities. The bacterial signalling and response system known as quorum sensing or Acylated Homoserine Lactone (AHL) mediated gene expression is thought to have evolved through kin selection. In this in vitro study on the model quorum sensing bioluminescent marine symbiont Vibrio fischeri, competition and long-term sub culturing experiments suggest that selection for AHL synthesis (encoded by the AHL synthase gene luxI) is independent of the quorum sensing regulated phenotype (bioluminescence encoded by luxCDABE). Whilst results support the hypothesis that signal response (AHL binding and transcriptional activation encoded by the luxR gene) is maintained through indirect fitness benefits (kin selection), signal synthesis is maintained in the V. fischeri genome over evolutionary time through direct fitness benefits at the individual level from an unknown function. PMID:23825662

  20. Assessing the function of STAS domain protein SypA in Vibrio fischeri using a comparative analysis.

    Science.gov (United States)

    Thompson, Cecilia M; Visick, Karen L

    2015-01-01

    Colonization of the squid Euprymna scolopes by Vibrio fischeri requires biofilm formation dependent on the 18-gene symbiosis polysaccharide locus, syp. One key regulator, SypA, controls biofilm formation by an as-yet unknown mechanism; however, it is known that SypA itself is regulated by SypE. Biofilm-proficient strains form wrinkled colonies on solid media, while sypA mutants form biofilm-defective smooth colonies. To begin to understand the function of SypA, we used comparative analyses and mutagenesis approaches. sypA (and the syp locus) is conserved in other Vibrios, including two food-borne human pathogens, Vibrio vulnificus (rbdA) and Vibrio parahaemolyticus (sypA VP ). We found that both homologs could complement the biofilm defect of the V. fischeri sypA mutant, but their phenotypes varied depending on the biofilm-inducing conditions used. Furthermore, while SypAVP retained an ability to be regulated by SypE, RbdA was resistant to this control. To better understand SypA function, we examined the biofilm-promoting ability of a number of mutant SypA proteins with substitutions in conserved residues, and found many that were biofilm-defective. The most severe biofilm-defective phenotypes occurred when changes were made to a conserved stretch of amino acids within a predicted α-helix of SypA; we hypothesize that this region of SypA may interact with another protein to promote biofilm formation. Finally, we identified a residue required for negative control by SypE. Together, our data provide insights into the function of this key biofilm regulator and suggest that the SypA orthologs may play similar roles in their native Vibrio species.

  1. Dose-response behavior of the bacterium Vibrio fischeri exposed to pharmaceuticals and personal care products.

    Science.gov (United States)

    Ortiz de García, Sheyla; García-Encina, Pedro A; Irusta-Mata, Rubén

    2016-01-01

    The presence of pharmaceuticals and personal care products (PPCPs) in the environment has become a real and widespread concern in recent years. Therefore, the primary goal of this study was to investigate 20 common and widely used PPCPs to assess their individual and combined effect on an important species in one trophic level, i.e., bacteria. The ecotoxicological effects of PPCPs at two different concentration ranges were determined in the bacterium Vibrio fischeri using Microtox(®) and were statistically analyzed using three models in the GraphPad Prism 6 program for Windows, v.6.03. A four-parameter model best fit the majority of the compounds. The half maximal effective concentration (EC50) of each PPCP was estimated using the best-fitting model and was compared with the results from a recent study. Comparative analysis indicated that most compounds showed the same level of toxicity. Moreover, the stimulatory effects of PPCPs at environmental concentrations (low doses) were assessed. These results indicated that certain compounds have traditional inverted U- or J-shaped dose-response curves, and 55% of them presented a stimulatory effect below the zero effect-concentration point. Effective concentrations of 0 (EC0), 5 (EC5) and 50% (EC50) were calculated for each PPCP as the ecotoxicological points. All compounds that presented narcosis as a mode of toxic action at high doses also exhibited stimulation at low concentrations. The maximum stimulatory effect of a mixture was higher than the highest stimulatory effect of each individually tested compound. Moreover, when the exposure time was increased, the hormetic effect decreased. Hormesis is being increasingly included in dose-response studies because this may have a harmful, beneficial or indifferent effect in an environment. Despite the results obtained in this research, further investigations need to be conducted to elucidate the behavior of PPCPs in aquatic environments.

  2. Global discovery of colonization determinants in the squid symbiont Vibrio fischeri.

    Science.gov (United States)

    Brooks, John F; Gyllborg, Mattias C; Cronin, David C; Quillin, Sarah J; Mallama, Celeste A; Foxall, Randi; Whistler, Cheryl; Goodman, Andrew L; Mandel, Mark J

    2014-12-02

    Animal epithelial tissue becomes reproducibly colonized by specific environmental bacteria. The bacteria (microbiota) perform critical functions for the host's tissue development, immune system development, and nutrition; yet the processes by which bacterial diversity in the environment is selected to assemble the correct communities in the host are unclear. To understand the molecular determinants of microbiota selection, we examined colonization of a simplified model in which the light organ of Euprymna scolopes squid is colonized exclusively by Vibrio fischeri bacteria. We applied high-throughput insertion sequencing to identify which bacterial genes are required during host colonization. A library of over 41,000 unique transposon insertions was analyzed before and after colonization of 1,500 squid hatchlings. Mutants that were reproducibly depleted following squid colonization represented 380 genes, including 37 that encode known colonization factors. Validation of select mutants in defined competitions against the wild-type strain identified nine mutants that exhibited a reproducible colonization defect. Some of the colonization factors identified included genes predicted to influence copper regulation and secretion. Other mutants exhibited defects in biofilm development, which is required for aggregation in host mucus and initiation of colonization. Biofilm formation in culture and in vivo was abolished in a strain lacking the cytoplasmic chaperone DnaJ, suggesting an important role for protein quality control during the elaboration of bacterial biofilm in the context of an intact host immune system. Overall these data suggest that cellular stress responses and biofilm regulation are critical processes underlying the reproducible colonization of animal hosts by specific microbial symbionts.

  3. NagC represses N-acetyl-glucosamine utilization genes in Vibrio fischeri within the light organ of Euprymna scolopes.

    Science.gov (United States)

    Sun, Yan; Verma, Subhash C; Bogale, Haikel; Miyashiro, Tim

    2015-01-01

    Bacteria often use transcription factors to regulate the expression of metabolic genes in accordance to available nutrients. NagC is a repressor conserved among γ-proteobacteria that regulates expression of enzymes involved in the metabolism of N-acetyl-glucosamine (GlcNAc). The polymeric form of GlcNAc, known as chitin, has been shown to play roles in chemotactic signaling and nutrition within the light organ symbiosis established between the marine bacterium Vibrio fischeri and the Hawaiian squid Euprymna scolopes. Here, we investigate the impact of NagC regulation on the physiology of V. fischeri. We find that NagC repression contributes to the fitness of V. fischeri in the absence of GlcNAc. In addition, the inability to de-repress expression of NagC-regulated genes reduces the fitness of V. fischeri in the presence of GlcNAc. We find that chemotaxis toward GlcNAc or chitobiose, a dimeric form of GlcNAc, is independent of NagC regulation. Finally, we show that NagC represses gene expression during the early stages of symbiosis. Our data suggest that the ability to regulate gene expression with NagC contributes to the overall fitness of V. fischeri in environments that vary in levels of GlcNAc. Furthermore, our finding that NagC represses gene expression within the squid light organ during an early stage of symbiosis supports the notion that the ability of the squid to provide a source of GlcNAc emerges later in host development.

  4. NagC represses N-acetyl-glucosamine utilization genes in Vibrio fischeri within the light organ of Euprymna scolopes

    Directory of Open Access Journals (Sweden)

    Yan eSun

    2015-07-01

    Full Text Available Bacteria often use transcription factors to regulate the expression of metabolic genes in accordance to available nutrients. NagC is a repressor conserved among γ-proteobacteria that regulates expression of enzymes involved in the metabolism of N-acetyl-glucosamine (GlcNAc. The polymeric form of GlcNAc, known as chitin, has been shown to play roles in chemotactic signaling and nutrition within the light organ symbiosis established between the marine bacterium Vibrio fischeri and the Hawaiian squid Euprymna scolopes. Here, we investigate the impact of NagC regulation on the physiology of V. fischeri. We find that NagC repression contributes to the fitness of V. fischeri in the absence of GlcNAc. In addition, the inability to de-repress expression of NagC-regulated genes reduces the fitness of V. fischeri in the presence of GlcNAc. We find that chemotaxis towards GlcNAc or chitobiose, a dimeric form of GlcNAc, is independent of NagC regulation. Finally, we show that NagC represses gene expression during the early stages of symbiosis. Our data suggest that the ability to regulate gene expression with NagC contributes to the overall fitness of V. fischeri in environments that vary in levels of GlcNAc. Furthermore, our finding that NagC represses gene expression within the squid light organ during an early stage of symbiosis supports the notion that the ability of the squid to provide a source of GlcNAc emerges later in host development.

  5. A genomic comparison of 13 symbiotic Vibrio fischeri isolates from the perspective of their host source and colonization behavior.

    Science.gov (United States)

    Bongrand, Clotilde; Koch, Eric J; Moriano-Gutierrez, Silvia; Cordero, Otto X; McFall-Ngai, Margaret; Polz, Martin F; Ruby, Edward G

    2016-12-01

    Newly hatched Euprymna scolopes squid obtain their specific light-organ symbionts from an array of Vibrio (Allivibrio) fischeri strains present in their environment. Two genetically distinct populations of this squid species have been identified, one in Kaneohe Bay (KB), and another in Maunaloa Bay (MB), Oahu. We asked whether symbionts isolated from squid in each of these populations outcompete isolates from the other population in mixed-infection experiments. No relationship was found between a strain's host source (KB or MB) and its ability to competitively colonize KB or MB juveniles in a mixed inoculum. Instead, two colonization behaviors were identified among the 11 KB and MB strains tested: a 'dominant' outcome, in which one strain outcompetes the other for colonization, and a 'sharing' outcome, in which two strains co-colonize the squid. A genome-level comparison of these and other V. fischeri strains suggested that the core genomic structure of this species is both syntenous and highly conserved over time and geographical distance. We also identified ~250 Kb of sequence, encoding 194 dispersed orfs, that was specific to those strains that expressed the dominant colonization behavior. Taken together, the results indicate a link between the genome content of V. fischeri strains and their colonization behavior when initiating a light-organ symbiosis.

  6. Oxidative stress and antioxidant enzymes activities in the African catfish, Clarias gariepinus, experimentally challenged with Escherichia coli and Vibrio fischeri.

    Science.gov (United States)

    Adeyemi, Joseph A

    2014-04-01

    The impacts of bacterial infection on cultivated fish species, African catfish, were investigated using oxidative stress biomarkers [lipid peroxidation (LPO) and protein carbonylation] and the activities of important antioxidant/detoxifying enzymes [catalase and glutathione S-transferase (GST)]. Fish were inoculated via oral gavage with one of the following treatments: 1 × 10(5) CFU/ml of Escherichia coli (EC1), 2 × 10(5) CFU/ml of E. coli (EC2), 1 × 10(5) CFU/ml of Vibrio fischeri (V1), 2 × 10(5) CFU/ml of V. fischeri (V2), gavaged with distilled water and not gavaged. Fish were maintained in the laboratory for 7 days after the bacterial inoculation, and the levels of LPO, protein carbonylation, GST, and catalase activities were determined in the muscle, gills, and liver of fish. Fish inoculated with bacteria (either E. coli or V. fischeri) had a significant higher levels of tissue LPO, protein carbonylation, and GST activities in a tissue-specific pattern (liver > muscle > gills). This appears to be related with the levels of bacterial inoculation, with effects more pronounced in fish inoculated with either EC2 or V2. The catalase activity did not differ significantly between the inoculated and fish that were not inoculated. The results of this study indicate that bacterial inoculation could result in oxidative stress in fish, and liver has a higher rate of oxidative stress per mg tissue compared to the gills and the muscle.

  7. Acute and Chronic Toxicity of Soluble Fractions of Industrial Solid Wastes on Daphnia magna and Vibrio fischeri

    Directory of Open Access Journals (Sweden)

    Letícia Flohr

    2012-01-01

    Full Text Available Industrial wastes may produce leachates that can contaminate the aquatic ecosystem. Toxicity testing in acute and chronic levels is essential to assess environmental risks from the soluble fractions of these wastes, since only chemical analysis may not be adequate to classify the hazard of an industrial waste. In this study, ten samples of solid wastes from textile, metal-mechanic, and pulp and paper industries were analyzed by acute and chronic toxicity tests with Daphnia magna and Vibrio fischeri. A metal-mechanic waste (sample MM3 induced the highest toxicity level to Daphnia magna(CE50,48 h=2.21%. A textile waste induced the highest toxicity level to Vibrio fischeri (sample TX2, CE50,30 min=12.08%. All samples of pulp and paper wastes, and a textile waste (sample TX2 induced chronic effects on reproduction, length, and longevity of Daphnia magna. These results could serve as an alert about the environmental risks of an inadequate waste classification method.

  8. Characterization of a Vibrio fischeri aminopeptidase and evidence for its influence on an early stage of squid colonization.

    Science.gov (United States)

    Fidopiastis, Pat M; Rader, Bethany A; Gerling, David G; Gutierrez, Nestor A; Watkins, Katherine H; Frey, Michelle West; Nyholm, Spencer V; Whistler, Cheryl A

    2012-08-01

    Vibrio fischeri cells are the sole colonists of a specialized light organ in the mantle cavity of the sepiolid squid Euprymna scolopes. The process begins when the bacteria aggregate in mucus secretions outside the light organ. The cells eventually leave the aggregate, enter the light organ, and encounter a rich supply of peptides. The need to dissociate from mucus and presumably utilize peptides led us to hypothesize that protease activity is integral to the colonization process. Protease activity associated with whole cells of Vibrio fischeri strain ES114 was identified as the product of a putative cell membrane-associated aminopeptidase (PepN). To characterize this activity, the aminopeptidase was cloned, overexpressed, and purified. Initial steady-state kinetic studies revealed that the aminopeptidase has broad activity, with a preference for basic and hydrophobic side chains and k(cat) and K(m) values that are lower and smaller, respectively, than those of Escherichia coli PepN. A V. fischeri mutant unable to produce PepN is significantly delayed in its ability to colonize squid within the first 12 h, but eventually it establishes a wild-type colonization level. Likewise, in competition with the wild type for colonization, the mutant is outcompeted at 12 h postinoculation but then competes evenly by 24 h. Also, the PepN-deficient strain fails to achieve wild-type levels of cells in aggregates, suggesting an explanation for the initial colonization delay. This study provides a foundation for more studies on PepN expression, localization, and role in the early stages of squid colonization.

  9. Characterization of a Vibrio fischeri Aminopeptidase and Evidence for Its Influence on an Early Stage of Squid Colonization

    Science.gov (United States)

    Rader, Bethany A.; Gerling, David G.; Gutierrez, Nestor A.; Watkins, Katherine H.; Frey, Michelle West; Nyholm, Spencer V.; Whistler, Cheryl A.

    2012-01-01

    Vibrio fischeri cells are the sole colonists of a specialized light organ in the mantle cavity of the sepiolid squid Euprymna scolopes. The process begins when the bacteria aggregate in mucus secretions outside the light organ. The cells eventually leave the aggregate, enter the light organ, and encounter a rich supply of peptides. The need to dissociate from mucus and presumably utilize peptides led us to hypothesize that protease activity is integral to the colonization process. Protease activity associated with whole cells of Vibrio fischeri strain ES114 was identified as the product of a putative cell membrane-associated aminopeptidase (PepN). To characterize this activity, the aminopeptidase was cloned, overexpressed, and purified. Initial steady-state kinetic studies revealed that the aminopeptidase has broad activity, with a preference for basic and hydrophobic side chains and kcat and Km values that are lower and smaller, respectively, than those of Escherichia coli PepN. A V. fischeri mutant unable to produce PepN is significantly delayed in its ability to colonize squid within the first 12 h, but eventually it establishes a wild-type colonization level. Likewise, in competition with the wild type for colonization, the mutant is outcompeted at 12 h postinoculation but then competes evenly by 24 h. Also, the PepN-deficient strain fails to achieve wild-type levels of cells in aggregates, suggesting an explanation for the initial colonization delay. This study provides a foundation for more studies on PepN expression, localization, and role in the early stages of squid colonization. PMID:22636772

  10. Purification and crystallization of Vibrio fischeri CcdB and its complexes with fragments of gyrase and CcdA

    Energy Technology Data Exchange (ETDEWEB)

    De Jonge, Natalie, E-mail: ndejonge@vub.ac.be; Buts, Lieven; Vangelooven, Joris [Department of Molecular and Cellular Interactions, VIB, Pleinlaan 2, 1050 Brussels (Belgium); Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Mine, Natacha; Van Melderen, Laurence [Laboratoire de Génétique des Procaryotes, Institut de Biologie et de Médecine, Université Libre de Bruxelles, Gosselies (Belgium); Wyns, Lode; Loris, Remy [Department of Molecular and Cellular Interactions, VIB, Pleinlaan 2, 1050 Brussels (Belgium); Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium)

    2007-04-01

    A CcdB homologue from V. fischeri was overexpressed in E. coli and purified. The free protein was crystallized, as were its complexes with fragments of E. coli and V. fischeri gyrase and with the F-plasmid CcdA C-terminal domain. The ccd toxin–antitoxin module from the Escherichia coli F plasmid has a homologue on the Vibrio fischeri integron. The homologue of the toxin (CcdB{sub Vfi}) was crystallized in two different crystal forms. The first form belongs to space group I23 or I2{sub 1}3, with unit-cell parameter a = 84.5 Å, and diffracts to 1.5 Å resolution. The second crystal form belongs to space group C2, with unit-cell parameters a = 58.5, b = 43.6, c = 37.5 Å, β = 110.0°, and diffracts to 1.7 Å resolution. The complex of CcdB{sub Vfi} with the GyrA14{sub Vfi} fragment of V. fischeri gyrase crystallizes in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 53.5, b = 94.6, c = 58.1 Å, and diffracts to 2.2 Å resolution. The corresponding mixed complex with E. coli GyrA14{sub Ec} crystallizes in space group C2, with unit-cell parameters a = 130.1, b = 90.8, c = 58.1 Å, β = 102.6°, and diffracts to 1.95 Å. Finally, a complex between CcdB{sub Vfi} and part of the F-plasmid antitoxin CcdA{sub F} crystallizes in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 46.9, b = 62.6, c = 82.0 Å, and diffracts to 1.9 Å resolution.

  11. Model-enabled gene search (MEGS) allows fast and direct discovery of enzymatic and transport gene functions in the marine bacterium Vibrio fischeri.

    Science.gov (United States)

    Pan, Shu; Nikolakakis, Kiel; Adamczyk, Paul A; Pan, Min; Ruby, Edward G; Reed, Jennifer L

    2017-06-16

    Whereas genomes can be rapidly sequenced, the functions of many genes are incompletely or erroneously annotated because of a lack of experimental evidence or prior functional knowledge in sequence databases. To address this weakness, we describe here a model-enabled gene search (MEGS) approach that (i) identifies metabolic functions either missing from an organism's genome annotation or incorrectly assigned to an ORF by using discrepancies between metabolic model predictions and experimental culturing data; (ii) designs functional selection experiments for these specific metabolic functions; and (iii) selects a candidate gene(s) responsible for these functions from a genomic library and directly interrogates this gene's function experimentally. To discover gene functions, MEGS uses genomic functional selections instead of relying on correlations across large experimental datasets or sequence similarity as do other approaches. When applied to the bioluminescent marine bacterium Vibrio fischeri, MEGS successfully identified five genes that are responsible for four metabolic and transport reactions whose absence from a draft metabolic model of V. fischeri caused inaccurate modeling of high-throughput experimental data. This work demonstrates that MEGS provides a rapid and efficient integrated computational and experimental approach for annotating metabolic genes, including those that have previously been uncharacterized or misannotated. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. The response regulator SypE controls biofilm formation and colonization through phosphorylation of the syp-encoded regulator SypA in Vibrio fischeri.

    Science.gov (United States)

    Morris, Andrew R; Visick, Karen L

    2013-02-01

    Bacteria utilize multiple regulatory systems to modulate gene expression in response to environmental changes, including two-component signalling systems and partner-switching networks. We recently identified a novel regulatory protein, SypE, that combines features of both signalling systems. SypE contains a central response regulator receiver domain flanked by putative kinase and phosphatase effector domains with similarity to partner-switching proteins. SypE was previously shown to exert dual control over biofilm formation through the opposing activities of its terminal effector domains. Here, we demonstrate that SypE controls biofilms in Vibrio fischeri by regulating the activity of SypA, a STAS (sulphate transporter and anti-sigma antagonist) domain protein. Using biochemical and genetic approaches, we determined that SypE both phosphorylates and dephosphorylates SypA, and that phosphorylation inhibits SypA's activity. Furthermore, we found that biofilm formation and symbiotic colonization required active, unphosphorylated SypA, and thus SypA phosphorylation corresponded with a loss of biofilms and impaired host colonization. Finally, expression of a non-phosphorylatable mutant of SypA suppressed both the biofilm and symbiosis defects of a constitutively inhibitory SypE mutant strain. This study demonstrates that regulation of SypA activity by SypE is a critical mechanism by which V. fischeri controls biofilm development and symbiotic colonization. © 2012 Blackwell Publishing Ltd.

  13. Assessing the function of STAS domain protein SypA in Vibrio fischeri using a comparative analysis

    Directory of Open Access Journals (Sweden)

    Cecilia M Thompson

    2015-07-01

    Full Text Available Colonization of the squid Euprymna scolopes by Vibrio fischeri requires biofilm formation dependent on the 18-gene symbiosis polysaccharide locus, syp. One key regulator, SypA, controls biofilm formation by an as-yet unknown mechanism; however, it is known that SypA itself is regulated by SypE. Biofilm-proficient strains form wrinkled colonies on solid media, while sypA mutants form biofilm-defective smooth colonies. To begin to understand the function of SypA, we used comparative analyses and mutagenesis approaches. sypA (and the syp locus is conserved in other Vibrios, including two food-borne human pathogens, V. vulnificus (rbdA and V. parahaemolyticus (sypAVP. We found that both homologs could complement the biofilm defect of the V. fischeri sypA mutant, but their phenotypes varied depending on the biofilm-inducing conditions used. Furthermore, while SypAVP retained an ability to be regulated by SypE, RbdA was resistant to this control. To better understand SypA function, we examined the biofilm-promoting ability of a number of mutant SypA proteins with substitutions in conserved residues, and found many that were biofilm-defective. The most severe biofilm-defective phenotypes occurred when changes were made to a conserved stretch of amino acids within a predicted a-helix of SypA; we hypothesize that this region of SypA may interact with another protein to promote biofilm formation. Finally, we identified a residue required for negative control by SypE. Together, our data provide insights into the function of this key biofilm regulator and suggest that the SypA orthologs may play similar roles in their native Vibrio species.

  14. TfoX-based genetic mapping identifies Vibrio fischeri strain-level differences and reveals a common lineage of laboratory strains.

    Science.gov (United States)

    Brooks, John F; Gyllborg, Mattias C; Kocher, Acadia A; Markey, Laura E H; Mandel, Mark J

    2015-03-01

    Bacterial strain variation exists in natural populations of bacteria and can be generated experimentally through directed or random mutation. The advent of rapid and cost-efficient whole-genome sequencing has facilitated strain-level genotyping. Even with modern tools, however, it often remains a challenge to map specific traits to individual genetic loci, especially for traits that cannot be selected under culture conditions (e.g., colonization level or pathogenicity). Using a combination of classical and modern approaches, we analyzed strain-level variation in Vibrio fischeri and identified the basis by which some strains lack the ability to utilize glycerol as a carbon source. We proceeded to reconstruct the lineage of the commonly used V. fischeri laboratory strains. Compared to the wild-type ES114 strain, we identify in ES114-L a 9.9-kb deletion with endpoints in tadB2 and glpF; restoration of the missing portion of glpF restores the wild-type phenotype. The widely used strains ESR1, JRM100, and JRM200 contain the same deletion, and ES114-L is likely a previously unrecognized intermediate strain in the construction of many ES114 derivatives. ES114-L does not exhibit a defect in competitive squid colonization but ESR1 does, demonstrating that glycerol utilization is not required for early squid colonization. Our genetic mapping approach capitalizes on the recently discovered chitin-based transformation pathway, which is conserved in the Vibrionaceae; therefore, the specific approach used is likely to be useful for mapping genetic traits in other Vibrio species. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. LuxCDABE—Transformed Constitutively Bioluminescent Escherichia coli for Toxicity Screening: Comparison with Naturally Luminous Vibrio fischeri

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    Anne Kahru

    2011-08-01

    Full Text Available We show that in vitro toxicity assay based on inhibition of the bioluminescence of recombinant Escherichia coli encoding thermostable luciferase from Photorhabdus luminescens is a versatile alternative to Vibrio fischeri MicrotoxTM test. Performance of two luxCDABE-transformed E. coli MC1061 constructs (pDNlux and (pSLlux otherwise identical, but having 100-fold different background luminescence was compared with the performance of V. fischeri. The microplate luminometer and a kinetic Flash-Assay test format was used that differently from Microtox test is also applicable for high throughput analysis. Toxic effects (30-s till 30-min EC50 of four heavy metals (Zn, Cd, Hg, Cu and three organic chemicals (aniline, 3,5-dichloroaniline and 3,5-dichlorophenol were studied. Both E. coli strains had comparable sensitivity and the respective 30-min EC50 values highly correlated (log-log R2 = 0.99; p < 0.01 showing that the sensitivity of the recombinant bacteria towards chemicals analyzed did not depend on the bioluminescence level of the recombinant cells. The most toxic chemical for all used bacterial strains (E. coli, V. fischeri was mercury whereas the lowest EC50 values for Hg (0.04–0.05 mg/L and highest EC50 values for aniline (1,300–1,700 mg/L were observed for E. coli strains. Despite of that, toxicity results obtained with both E. coli strains (pSLlux and pDNlux significantly correlated with V. fischeri results (log-log R2 = 0.70/0.75; p < 0.05/0.01. The use of amino acids (0.25% and glucose (0.05%-supplemented M9 medium instead of leucine-supplemented saline significantly (p < 0.05 reduced the apparent toxicity of heavy metals to both E. coli strains up to three orders of magnitude, but had little or no complexing effect on organic compounds. Thus, P. luminescens luxCDABE-transformed E. coli strains can be successfully used for the acute toxicity screening of various types of organic chemicals and heavy metals and can replace V. fischeri in

  16. LuxCDABE--transformed constitutively bioluminescent Escherichia coli for toxicity screening: comparison with naturally luminous Vibrio fischeri.

    Science.gov (United States)

    Kurvet, Imbi; Ivask, Angela; Bondarenko, Olesja; Sihtmäe, Mariliis; Kahru, Anne

    2011-01-01

    We show that in vitro toxicity assay based on inhibition of the bioluminescence of recombinant Escherichia coli encoding thermostable luciferase from Photorhabdus luminescens is a versatile alternative to Vibrio fischeri Microtox™ test. Performance of two luxCDABE-transformed E. coli MC1061 constructs (pDNlux) and (pSLlux) otherwise identical, but having 100-fold different background luminescence was compared with the performance of V. fischeri. The microplate luminometer and a kinetic Flash-Assay test format was used that differently from Microtox test is also applicable for high throughput analysis. Toxic effects (30-s till 30-min EC(50)) of four heavy metals (Zn, Cd, Hg, Cu) and three organic chemicals (aniline, 3,5-dichloroaniline and 3,5-dichlorophenol) were studied. Both E. coli strains had comparable sensitivity and the respective 30-min EC(50) values highly correlated (log-log R(2) = 0.99; p E. coli, V. fischeri) was mercury whereas the lowest EC(50) values for Hg (0.04-0.05 mg/L) and highest EC(50) values for aniline (1,300-1,700 mg/L) were observed for E. coli strains. Despite of that, toxicity results obtained with both E. coli strains (pSLlux and pDNlux) significantly correlated with V. fischeri results (log-log R(2) = 0.70/0.75; p heavy metals to both E. coli strains up to three orders of magnitude, but had little or no complexing effect on organic compounds. Thus, P. luminescens luxCDABE-transformed E. coli strains can be successfully used for the acute toxicity screening of various types of organic chemicals and heavy metals and can replace V. fischeri in certain cases where the thermostability of luciferase >30 °C is crucial. The kinetic Flash Assay test format of the bioluminescence inhibition assay facilitates high throughput analysis. The assay medium, especially in case of testing heavy metals should be a compromise: optimal for the viability/luminescence of the recombinant test strain and of minimum complexing potential.

  17. Bright luminescence of Vibrio fischeri aconitase mutants reveals a connection between citrate and the Gac/Csr regulatory system.

    Science.gov (United States)

    Septer, Alecia N; Bose, Jeffrey L; Lipzen, Anna; Martin, Joel; Whistler, Cheryl; Stabb, Eric V

    2015-01-01

    The Gac/Csr regulatory system is conserved throughout the γ-proteobacteria and controls key pathways in central carbon metabolism, quorum sensing, biofilm formation and virulence in important plant and animal pathogens. Here we show that elevated intracellular citrate levels in a Vibrio fischeri aconitase mutant correlate with activation of the Gac/Csr cascade and induction of bright luminescence. Spontaneous or directed mutations in the gene that encodes citrate synthase reversed the bright luminescence of aconitase mutants, eliminated their citrate accumulation and reversed their elevated expression of CsrB. Our data elucidate a correlative link between central metabolic and regulatory pathways, and they suggest that the Gac system senses a blockage at the aconitase step of the tricarboxylic acid cycle, either through elevated citrate levels or a secondary metabolic effect of citrate accumulation, and responds by modulating carbon flow and various functions associated with host colonization, including bioluminescence. © 2014 John Wiley & Sons Ltd.

  18. Automated evaluation of pharmaceutically active ionic liquids' (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri.

    Science.gov (United States)

    Costa, Susana P F; Justina, Vanessa D; Bica, Katharina; Vasiloiu, Maria; Pinto, Paula C A G; Saraiva, M Lúcia M F S

    2014-01-30

    The toxicity of 16 pharmaceutical active ionic liquids (IL-APIs) was evaluated by automated approaches based on sequential injection analysis (SIA). The implemented bioassays were centered on the inhibition of human carboxylesterase 2 and Vibrio fischeri, in the presence of the tested compounds. The inhibitory effects were quantified by calculating the inhibitor concentration required to cause 50% of inhibition (EC50). The EC50 values demonstrated that the cetylpyridinium group was one of the most toxic cations and that the imidazolium group was the less toxic. The obtained results provide important information about the safety of the studied IL-APIs and their possible use as pharmaceutical drugs. The developed automated SIA methodologies are robust screening bioassays, and can be used as a generic tools to identify the (eco)toxicity of the structural elements of ILs, contributing to a sustainable development of drugs. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Vibrio fischeri and Escherichia coli adhesion tendencies towards photolithographically modified nanosmooth poly (tert-butyl methacrylate polymer surfaces

    Directory of Open Access Journals (Sweden)

    Elena P Ivanova

    2008-09-01

    Full Text Available Elena P Ivanova1, Natasa Mitik-Dineva1, Radu C Mocanasu1, Sarah Murphy1, James Wang2, Grant van Riessen3, Russell J Crawford11Faculty Life and Social Sciences; 2IRIS, Swinburne University of Technology, Hawthorn, Victoria, Australia; 3Centre for Materials and Surface Science, La Trobe University, Melbourne, Victoria, AustraliaAbstract: This study reports the adhesion behavior of two bacterial species, Vibrio fischeri and Escherichia coli, to the photoresistant poly(tert-butyl methacrylate (P(tBMA polymer surface. The data has demonstrated that ultraviolet irradiation of P(tBMA was able to provide control over bacterial adhesion tendencies. Following photolithography, several of the surface characteristics of P(tBMA were found to be altered. Atomic force microscopy analysis indicated that photolithographically modified P(tBMA (henceforth termed ‘modified polymer’ appeared as a ‘nanosmooth’ surface with an average surface roughness of 1.6 nm. Although confocal laser scanning microscopy and scanning electron microscopy analysis clearly demonstrated that V. fischeri and E. coli presented largely different patterns of attachment in order to adhere to the same surfaces, both species exhibited a greater adhesion propensity towards the ‘nanosmooth’ surface. The adhesion of both species to the modified polymer surface appeared to be facilitated by an elevated production of extracellular polymeric substances when in contact with the substrate.Keywords: poly(tert-butylmethacrylate polymeric surfaces, surface nanotopography, bacterial attachment, extracellular polymeric substances

  20. Experimental and predicted acute toxicity of antibacterial compounds and their mixtures using the luminescent bacterium Vibrio fischeri.

    Science.gov (United States)

    Villa, Sara; Vighi, Marco; Finizio, Antonio

    2014-08-01

    This article investigates the bioluminescence inhibition effects of the antimicrobials triclocarban, triclosan and its metabolite methyl triclosan, using the marine bacterium Vibrio fischeri as the test organism (Microtox©). The concentration response analysis was performed for the three individual substances and for a mixture in which the three compounds were mixed in a ratio of the IC50 of the individual components (equitoxic ratio). Toxicity values (the median inhibitory concentration value, in mg L(-1)) in the decreasing order of sensitivity were triclosan (0.73)>triclocarban (0.91)>methyl-triclosan (1.76). The comparison of the experimental data with those obtained by using Quantitative Structure-Activity Relationship (QSAR) equations indicated that triclosan and triclocarban act as polar narcotic compounds towards V. fischeri, whereas methyl-triclosan acts as a narcotic (baseline toxicity). The toxicity of the mixture was measured experimentally and predicted by two models (CA: concentration addition; IA: independent action). The results showed that the observed mixture toxicity (IC50=0.23 mg L(-1)) had no significant differences from those predicted by both CA and IA models. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Bioluminescent Vibrio fischeri Assays in the Assessment of Seasonal and Spatial Patterns in Toxicity of Contaminated River Sediments.

    Science.gov (United States)

    Jarque, Sergio; Masner, Petr; Klánová, Jana; Prokeš, Roman; Bláha, Ludek

    2016-01-01

    Several bacteria-based assays, notably Vibrio fischeri luminescence assays, are often used as environmental monitoring tool for toxicity in sediments that may serve as both sinks and secondary source of contamination in aquatic ecosystems. In this study, we used 30-s kinetic bioassays based on V. fischeri to evaluate the toxicity associated to sediments from five localities with different contamination inputs (Morava River and its tributary Drevnice River in the south-eastern part of the Czech Republic). Toxicity assessed as half maximal inhibitory concentration (IC50) over the course of a year-long sampling was compared in bottom sediments and freshly trapped particulate material. Standard approach based on testing of aqueous elutriates was compared with toxicity of whole sediments (contact suspension toxicity). Bottom sediments showed lower toxicity compared to freshly trapped suspended materials in all cases. On the other hand, standardized elutriates induced generally weaker effects than suspended sediments likely due to losses during the extraction process. Toxicity generally increased during winter reaching maximum peaks in early spring months in all five sites. Total organic carbon (TOC) was found to be highly correlated with toxic effects. Toxicity from sites with direct industrial and agricultural water inputs also correlated with concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). Single time point sampling followed by the extraction and testing of elutriates, do not truly reflect the spatial and temporal variability in natural sediments and may lead to underestimation of ecotoxic risks.

  2. Characterizing the Host and Symbiont Proteomes in the Association between the Bobtail Squid, Euprymna scolopes, and the Bacterium, Vibrio fischeri

    Science.gov (United States)

    Schleicher, Tyler R.; Nyholm, Spencer V.

    2011-01-01

    The beneficial symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium, Vibrio fischeri, provides a unique opportunity to study host/microbe interactions within a natural microenvironment. Colonization of the squid light organ by V. fischeri begins a lifelong association with a regulated daily rhythm. Each morning the host expels an exudate from the light organ consisting of 95% of the symbiont population in addition to host hemocytes and shed epithelial cells. We analyzed the host and symbiont proteomes of adult squid exudate and surrounding light organ epithelial tissue using 1D- and 2D-polyacrylamide gel electrophoresis and multidimensional protein identification technology (MudPIT) in an effort to understand the contribution of both partners to the maintenance of this association. These proteomic analyses putatively identified 1581 unique proteins, 870 proteins originating from the symbiont and 711 from the host. Identified host proteins indicate a role of the innate immune system and reactive oxygen species (ROS) in regulating the symbiosis. Symbiont proteins detected enhance our understanding of the role of quorum sensing, two-component signaling, motility, and detoxification of ROS and reactive nitrogen species (RNS) inside the light organ. This study offers the first proteomic analysis of the symbiotic microenvironment of the adult light organ and provides the identification of proteins important to the regulation of this beneficial association. PMID:21998678

  3. Inactivation of a novel response regulator is necessary for biofilm formation and host colonization by Vibrio fischeri.

    Science.gov (United States)

    Morris, Andrew R; Darnell, Cynthia L; Visick, Karen L

    2011-10-01

    The marine bacterium Vibrio fischeri uses a biofilm to promote colonization of its eukaryotic host Euprymna scolopes. This biofilm depends on the symbiosis polysaccharide (syp) locus, which is transcriptionally regulated by the RscS-SypG two-component regulatory system. An additional response regulator (RR), SypE, exerts both positive and negative control over biofilm formation. SypE is a novel RR protein, with its three putative domains arranged in a unique configuration: a central phosphorylation receiver (REC) domain flanked by two effector domains with putative enzymatic activities (serine kinase and serine phosphatase). To determine how SypE regulates biofilm formation and host colonization, we generated a library of SypE domain mutants. Our results indicate that the N-terminus inhibits biofilm formation, while the C-terminus plays a positive role. The phosphorylation state of SypE appears to regulate these opposing activities, as disruption of the putative site of phosphorylation results in a protein that constitutively inhibits biofilm formation. Furthermore, SypE restricts host colonization: (i) sypE mutants with constitutive inhibitory activity fail to efficiently initiate host colonization and (ii) loss of sypE partially alleviates the colonization defect of an rscS mutant. We conclude that SypE must be inactivated to promote symbiotic colonization by V. fischeri. © 2011 Blackwell Publishing Ltd.

  4. Bioluminescent Vibrio fischeri assays in the assessment of seasonal and spatial patterns in toxicity of contaminated river sediments

    Directory of Open Access Journals (Sweden)

    Sergio Jarque

    2016-11-01

    Full Text Available Several bacteria-based assays, notably Vibrio fischeri luminescence assays, are often used as environmental monitoring tool for toxicity in sediments that may serve as both sinks and secondary source of contamination in aquatic ecosystems. In this study, we used 30-s kinetic bioassays based on V. fischeri to evaluate the toxicity associated to sediments from five localities with different contamination inputs (Morava River and its tributary Drevnice River in the south-eastern part of the Czech Republic. Toxicity assessed as half maximal inhibitory concentration (IC50 over the course of a year-long sampling was compared in bottom sediments and freshly trapped particulate material. Standard approach based on testing of aqueous elutriates was compared with toxicity of whole sediments (contact suspension toxicity. Bottom sediments showed lower toxicity compared to freshly trapped suspended materials in all cases. On the other hand, standardized elutriates induced generally weaker effects than suspended sediments likely due to losses during the extraction process. Toxicity generally increased during winter reaching maximum peaks in early spring months in all five sites. Total organic carbon (TOC was found to be highly correlated with toxic effects. Toxicity from sites with direct industrial and agricultural water inputs also correlated with concentrations of metals, polycyclic aromatic hydrocarbons (PAHs and polychlorinated biphenyls (PCBs. Single time point sampling followed by the extraction and testing of elutriates, do not truly reflect the spatial and temporal variability in natural sediments and may lead to underestimation of ecotoxic risks.

  5. Joint toxicity of tetracycline with copper(II) and cadmium(II) to Vibrio fischeri: effect of complexation reaction.

    Science.gov (United States)

    Tong, Fei; Zhao, Yanping; Gu, Xueyuan; Gu, Cheng; Lee, Charles C C

    2015-03-01

    Co-contamination of antibiotic and heavy metals commonly occurs in the environment. Tetracycline (TC), a common antibiotic, can behave as an efficient organic ligand to complex with cations. In this paper, the joint toxicity of TC with two commonly existing metals, copper(II) and cadmium(II), towards a luminescent bacteria, Vibrio fischeri, are investigated. Results showed that coexistence of TC and Cu(II) showed a significant antagonistic effect, while TC and Cd(II) showed a synergistic effect. The aqueous speciation of TC with two metal cations was calculated using a chemical equilibrium software Visual MINTEQ and results indicated that a strong complexation exist between TC and Cu(II), while much weaker interaction between TC and Cd(II). Traditional joint toxicity prediction model based on independent action failed to predict the combined toxicity of TC with metals. A new method based on speciation calculation was used to evaluate the joint toxicity of ligands and cations. It is assumed that the metal-ligand complexes are non-toxic to V. fischeri and the joint toxicity is determined by the sum of toxic unit of free metal-ions and free organic ligands. It explained the joint toxicity of the mixed systems reasonably well. Meanwhile, citric acid (CA) and fulvic acid (FA) were also introduced in this study to provide a benchmark comparison with TC. Results showed it is also valid for mixed systems of CA and FA with metals except for the Cd-CA mixture.

  6. Characterizing the host and symbiont proteomes in the association between the Bobtail squid, Euprymna scolopes, and the bacterium, Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Tyler R Schleicher

    Full Text Available The beneficial symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium, Vibrio fischeri, provides a unique opportunity to study host/microbe interactions within a natural microenvironment. Colonization of the squid light organ by V. fischeri begins a lifelong association with a regulated daily rhythm. Each morning the host expels an exudate from the light organ consisting of 95% of the symbiont population in addition to host hemocytes and shed epithelial cells. We analyzed the host and symbiont proteomes of adult squid exudate and surrounding light organ epithelial tissue using 1D- and 2D-polyacrylamide gel electrophoresis and multidimensional protein identification technology (MudPIT in an effort to understand the contribution of both partners to the maintenance of this association. These proteomic analyses putatively identified 1581 unique proteins, 870 proteins originating from the symbiont and 711 from the host. Identified host proteins indicate a role of the innate immune system and reactive oxygen species (ROS in regulating the symbiosis. Symbiont proteins detected enhance our understanding of the role of quorum sensing, two-component signaling, motility, and detoxification of ROS and reactive nitrogen species (RNS inside the light organ. This study offers the first proteomic analysis of the symbiotic microenvironment of the adult light organ and provides the identification of proteins important to the regulation of this beneficial association.

  7. An annotated cDNA library of juvenile Euprymna scolopes with and without colonization by the symbiont Vibrio fischeri

    Directory of Open Access Journals (Sweden)

    Tong Deyan

    2006-06-01

    Full Text Available Abstract Background Biologists are becoming increasingly aware that the interaction of animals, including humans, with their coevolved bacterial partners is essential for health. This growing awareness has been a driving force for the development of models for the study of beneficial animal-bacterial interactions. In the squid-vibrio model, symbiotic Vibrio fischeri induce dramatic developmental changes in the light organ of host Euprymna scolopes over the first hours to days of their partnership. We report here the creation of a juvenile light-organ specific EST database. Results We generated eleven cDNA libraries from the light organ of E. scolopes at developmentally significant time points with and without colonization by V. fischeri. Single pass 3' sequencing efforts generated 42,564 expressed sequence tags (ESTs of which 35,421 passed our quality criteria and were then clustered via the UIcluster program into 13,962 nonredundant sequences. The cDNA clones representing these nonredundant sequences were sequenced from the 5' end of the vector and 58% of these resulting sequences overlapped significantly with the associated 3' sequence to generate 8,067 contigs with an average sequence length of 1,065 bp. All sequences were annotated with BLASTX (E-value Conclusion Both the number of ESTs generated from each library and GO categorizations are reflective of the activity state of the light organ during these early stages of symbiosis. Future analyses of the sequences identified in these libraries promise to provide valuable information not only about pathways involved in colonization and early development of the squid light organ, but also about pathways conserved in response to bacterial colonization across the animal kingdom.

  8. Inhibition of SypG-induced biofilms and host colonization by the negative regulator SypE in Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Andrew R Morris

    Full Text Available Vibrio fischeri produces a specific biofilm to promote colonization of its eukaryotic host, the squid Euprymna scolopes. Formation of this biofilm is induced by the sensor kinase RscS, which functions upstream of the response regulator SypG to regulate transcription of the symbiosis polysaccharide (syp locus. Biofilm formation is also controlled by SypE, a multi-domain response regulator that consists of a central regulatory receiver (REC domain flanked by an N-terminal serine kinase domain and a C-terminal serine phosphatase domain. SypE permits biofilm formation under rscS overexpression conditions, but inhibits biofilms induced by overexpression of sypG. We previously investigated the function of SypE in controlling biofilm formation induced by RscS. Here, we examined the molecular mechanism by which SypE naturally inhibits SypG-induced biofilms. We found that SypE's N-terminal kinase domain was both required and sufficient to inhibit SypG-induced biofilms. This effect did not occur at the level of syp transcription. Instead, under sypG-overexpressing conditions, SypE inhibited biofilms by promoting the phosphorylation of another syp regulator, SypA, a putative anti-sigma factor antagonist. Inhibition by SypE of SypG-induced biofilm formation could be overcome by the expression of a non-phosphorylatable SypA mutant, indicating that SypE functions primarily if not exclusively to control SypA activity via phosphorylation. Finally, the presence of SypE was detrimental to colonization under sypG-overexpressing conditions, as cells deleted for sypE outcompeted wild-type cells for colonization when both strains overexpressed sypG. These results provide further evidence that biofilm formation is critical to symbiotic colonization, and support a model in which SypE naturally functions to restrict biofilm formation, and thus host colonization, to the appropriate environmental conditions.

  9. An Expanded Transposon Mutant Library Reveals that Vibrio fischeri δ-Aminolevulinate Auxotrophs Can Colonize Euprymna scolopes.

    Science.gov (United States)

    Lyell, Noreen L; Septer, Alecia N; Dunn, Anne K; Duckett, Drew; Stoudenmire, Julie L; Stabb, Eric V

    2017-03-01

    Libraries of defined mutants are valuable research tools but necessarily lack gene knockouts that are lethal under the conditions used in library construction. In this study, we augmented a Vibrio fischeri mutant library generated on a rich medium (LBS, which contains [per liter] 10 g of tryptone, 5 g of yeast extract, 20 g of NaCl, and 50 mM Tris [pH 7.5]) by selecting transposon insertion mutants on supplemented LBS and screening for those unable to grow on LBS. We isolated strains with insertions in alr, glr (murI), glmS, several heme biosynthesis genes, and ftsA, as well as a mutant disrupted 14 bp upstream of ftsQ Mutants with insertions in ftsA or upstream of ftsQ were recovered by addition of Mg2+ to LBS, but their cell morphology and motility were affected. The ftsA mutant was more strongly affected and formed cells or chains of cells that appeared to wind back on themselves helically. Growth of mutants with insertions in glmS, alr, or glr was recovered with N-acetylglucosamine (NAG), d-alanine, or d-glutamate, respectively. We hypothesized that NAG, d-alanine, or d-glutamate might be available to V. fischeri in the Euprymna scolopes light organ; however, none of these mutants colonized the host effectively. In contrast, hemA and hemL mutants, which are auxotrophic for δ-aminolevulinate (ALA), colonized at wild-type levels, although mutants later in the heme biosynthetic pathway were severely impaired or unable to colonize. Our findings parallel observations that legume hosts provide Bradyrhizobium symbionts with ALA, but they contrast with virulence phenotypes of hemA mutants in some pathogens. The results further inform our understanding of the symbiotic light organ environment.IMPORTANCE By supplementing a rich yeast-based medium, we were able to recover V. fischeri mutants with insertions in conditionally essential genes, and further characterization of these mutants provided new insights into this bacterium's symbiotic environment. Most notably, we

  10. Comparative evaluation of acute toxicity by Vibrio fischeri and fern spore based bioassays in the follow-up of toxic chemicals degradation by photocatalysis.

    Science.gov (United States)

    Marugán, Javier; Bru, David; Pablos, Cristina; Catalá, Myriam

    2012-04-30

    The development of efficient bioassays is a necessary step for cost-effective environmental monitoring and evaluation of novel decontamination technologies. Marine Vibrio fischeri kits have demonstrated to be extremely sensitive but lack of ecological relevance, especially when assessing impacts on freshwater higher organisms. A novel riparian are fern spore microbioassay could merge higher ecological relevance and reduced costs. The aim of this work is the comparative evaluation of the V. fischeri and fern spore bioassays for the follow up of detoxification processes of water contaminated with cyanide and phenol by advanced oxidation technologies, using heterogeneous photocatalysis as example. In both cases, EC(50) values differed significantly for V. fischeri commercial kit, V. fischeri lab cultures and Polystichum setiferum fern spores (1.9, 16 and 101 mg cyanide L(-1) and 27.0, 49.3 and 1440 mg phenol L(-1), respectively). Whereas V. fischeri bioassays are extremely sensitive and dilution series must be prepared, toxicant solutions can be directly applied to spores. Spore microbioassay was also useful in the follow up of photoxidation processes of cyanide and phenol, also reflecting the formation of intermediate degradation by-products even more toxic than phenol. We conclude that this new microbioassay is a promising cost-effective tool for the follow up of decontamination processes. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Toxicity of Nine (Doped) Rare Earth Metal Oxides and Respective Individual Metals to Aquatic Microorganisms Vibrio fischeri and Tetrahymena thermophila.

    Science.gov (United States)

    Kurvet, Imbi; Juganson, Katre; Vija, Heiki; Sihtmäe, Mariliis; Blinova, Irina; Syvertsen-Wiig, Guttorm; Kahru, Anne

    2017-07-05

    Despite the increasing use of rare earth elements (REEs) and oxides (REOs) in various technologies, the information on their ecotoxicological hazard is scarce. Here, the effects of La(3+), Ce(3+), Pr(3+), Nd(3+), Gd(3+), CeO₂, and eight doped REOs to marine bacteria Vibrio fischeri and freshwater protozoa Tetrahymena thermophila were studied in parallel with REO dopant metals (Co(2+), Fe(3+), Mn(2+), Ni(2+), Sr(2+)). The highest concentrations of REOs tested were 100 mg/L with protozoa in deionized water and 500 mg/L with bacteria in 2% NaCl. Although (i) most REOs produced reactive oxygen species; (ii) all studied soluble REEs were toxic to bacteria (half-effective concentration, EC50 3.5-21 mg metal/L; minimal bactericidal concentration, MBC 6.3-63 mg/L) and to protozoa (EC50 28-42 mg/L); and (iii) also some dopant metals (Ni(2+), Fe(3+)) proved toxic (EC50 ≤ 3 mg/L), no toxicity of REOs to protozoa (EC50 > 100 mg/L) and bacteria (EC50 > 500 mg/L; MBC > 500 mg/L) was observed except for La₂NiO₄ (MBC 25 mg/L). According to kinetics of V. fischeri bioluminescence, the toxicity of REEs was triggered by disturbing cellular membrane integrity. Fortunately, as REEs and REOs are currently produced in moderate amounts and form in the environment insoluble salts and/or oxides, they apparently present no harm to aquatic bacteria and protozoa.

  12. Comparative evaluation of acute and chronic toxicities of CuO nanoparticles and bulk using Daphnia magna and Vibrio fischeri.

    Science.gov (United States)

    Rossetto, Ana Letícia de O F; Melegari, Silvia Pedroso; Ouriques, Luciane Cristina; Matias, William Gerson

    2014-08-15

    Copper oxide (CuO) has various applications, as highlighted by the incorporation of this compound as a biocide of antifouling paints for coating ships and offshore oil platforms. The objective of this study was to evaluate and compare the aquatic toxicity of CuO nanoparticles (NPs) and microparticles (MPs) through acute and chronic toxicity tests with the freshwater microcrustacean Daphnia magna and an acute toxicity test with the bioluminescent marine bacteria Vibrio fischeri. Acute toxicity results for D. magna in tests with CuO NPs (EC50, 48 h=22 mg L(-1)) were ten times higher than those for tests with CuO MPs (EC50, 48 h=223.6 mg L(-1)). In both periods of exposure of V. fischeri, the CuO NPs (EC50, 15m 248±56.39 - equivalent to 12.40%; EC50, 30 m 257.6±30.8 mg L(-1) - equivalent to 12.88%) were more toxic than the CuO MPs (EC50, 15m 2404.6±277.4 - equivalent to 60.10%; EC50, 30 m 1472.9±244.7 mg L(-1) - equivalent to 36.82%). In chronic toxicity tests, both forms of CuO showed significant effects (p<0.05) on the growth and reproduction parameters of the D. magna relative to the control. Additionally, morphological changes, such as lack of apical spine development and malformed carapaces in D. magna, were observed for organisms after the chronic test. The toxicity results demonstrate that CuO NPs have a higher level of toxicity than CuO MPs, emphasizing the need for comparative toxicological studies to correctly classify these two forms of CuO with identical CAS registration numbers. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. A Spectral-SAR Model for the Anionic-Cationic Interaction in Ionic Liquids: Application to Vibrio fischeri Ecotoxicity

    Directory of Open Access Journals (Sweden)

    Vasile Ostafe

    2007-08-01

    Full Text Available Within the recently launched the spectral-structure activity relationship (S-SARanalysis, the vectorial anionic-cationic model of a generic ionic liquid is proposed, alongwith the associated algebraic correlation factor in terms of the measured and predictedactivity norms. The reliability of the present scheme is tested by assessing the Hanschfactors, i.e. lipophylicity, polarizability and total energy, to predict the ecotoxicityendpoints of wide types of ionic liquids with ammonium, pyridinium, phosphonium,choline and imidazolium cations on the aquatic bacteria Vibrio fischeri. The results, whileconfirming the cationic dominant influence when only lipophylicity is considered,demonstrate that the anionic effect dominates all other more specific interactions. It wasalso proved that the S-SAR vectorial model predicts considerably higher activity for theionic liquids than for its anionic and cationic subsystems separately, in all consideredcases. Moreover, through applying the least norm-correlation path principle, the completetoxicological hierarchies are presented, unfolding the ecological rules of combined cationicand anionic influences in ionic liquid toxicity.

  14. Impact of Surface-Active Guanidinium-, Tetramethylguanidinium-, and Cholinium-Based Ionic Liquids on Vibrio Fischeri Cells and Dipalmitoylphosphatidylcholine Liposomes

    Science.gov (United States)

    Rantamäki, Antti H.; Ruokonen, Suvi-Katriina; Sklavounos, Evangelos; Kyllönen, Lasse; King, Alistair W. T.; Wiedmer, Susanne K.

    2017-04-01

    We investigated the toxicological effect of seven novel cholinium, guanidinium, and tetramethylguanidinium carboxylate ionic liquids (ILs) from an ecotoxicological point of view. The emphasis was on the potential structure-toxicity dependency of these surface-active ILs in aqueous environment. The median effective concentrations (EC50) were defined for each IL using Vibrio (Aliivibrio) fischeri marine bacteria. Dipalmitoylphosphatidylcholine (DPPC) liposomes were used as biomimetic lipid membranes to study the interactions between the surface-active ILs and the liposomes. The interactions were investigated by following the change in the DPPC phase transition behaviour using differential scanning calorimetry (DSC). Critical micelle concentrations for the ILs were determined to clarify the analysis of the toxicity and the interaction results. Increasing anion alkyl chain length increased the toxicity, whereas branching of the chain decreased the toxicity of the ILs. The toxicity of the ILs in this study was mainly determined by the surface-active anions, while cations induced a minor impact on the toxicity. In the DSC experiments the same trend was observed for all the studied anions, whereas the cations seemed to induce more variable impact on the phase transition behaviour. Toxicity measurements combined with liposome interaction studies can provide a valuable tool for assessing the mechanism of toxicity.

  15. Automated evaluation of pharmaceutically active ionic liquids’ (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Susana P.F.; Justina, Vanessa D. [REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto (Portugal); Bica, Katharina; Vasiloiu, Maria [Vienna University of Technology, Institute of Applied and Synthetic Chemistry, A-1060 Vienna (Austria); Pinto, Paula C.A.G., E-mail: ppinto@ff.up.pt [REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto (Portugal); Saraiva, M. Lúcia M.F.S., E-mail: lsaraiva@ff.up.pt [REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto (Portugal)

    2014-01-30

    Highlights: • IL-APIs toxicity on humans and aquatic environment was evaluated by inhibition assays. • The inhibition assays were implemented through automated screening bioassays. • Automation of bioassays enabled a rigorous control of the reaction conditions. • EC{sub 50} obtained provide vital information on IL-APIs safety and potential use as drugs. -- Abstract: The toxicity of 16 pharmaceutical active ionic liquids (IL-APIs) was evaluated by automated approaches based on sequential injection analysis (SIA). The implemented bioassays were centered on the inhibition of human carboxylesterase 2 and Vibrio fischeri, in the presence of the tested compounds. The inhibitory effects were quantified by calculating the inhibitor concentration required to cause 50% of inhibition (EC{sub 50}). The EC{sub 50} values demonstrated that the cetylpyridinium group was one of the most toxic cations and that the imidazolium group was the less toxic. The obtained results provide important information about the safety of the studied IL-APIs and their possible use as pharmaceutical drugs. The developed automated SIA methodologies are robust screening bioassays, and can be used as a generic tools to identify the (eco)toxicity of the structural elements of ILs, contributing to a sustainable development of drugs.

  16. The time-dependent stimulation of sodium halide salts on redox reactants, energy supply and luminescence in Vibrio fischeri.

    Science.gov (United States)

    Yu, Zhenyang; Zhang, Jing; Hou, Meifang

    2017-08-28

    The excess of halide ions (F(-), Cl(-), Br(-), I(-)) can cause adverse effects. Earlier studies demonstrated time-dependent stimulations of organic salts with halide ions on photobacteria. Therefore, inorganic ones with halide ions (e.g., NaX, X=F(-), Cl(-), Br(-), I(-)) were assumed to cause similar effects. In the present study, Vibrio fischeri was exposed to NaX. Results showed that the contents of favin mono-nucleotide (FMN), nicotinamide adenine dinucleotide (NADH), and nicotinamide adenine dinucleotide phosphate (NADPH) were stimulated by NaX with a time-dependent fashion. The maximum stimulations on FMN at 24h were 172%, 168%, 211% and 298% of the control (p<0.05) in NaF, NaCl, NaBr and NaI, respectively, with an order of NaF≈NaCl

  17. Impact of Surface-Active Guanidinium-, Tetramethylguanidinium-, and Cholinium-Based Ionic Liquids on Vibrio Fischeri Cells and Dipalmitoylphosphatidylcholine Liposomes.

    Science.gov (United States)

    Rantamäki, Antti H; Ruokonen, Suvi-Katriina; Sklavounos, Evangelos; Kyllönen, Lasse; King, Alistair W T; Wiedmer, Susanne K

    2017-04-21

    We investigated the toxicological effect of seven novel cholinium, guanidinium, and tetramethylguanidinium carboxylate ionic liquids (ILs) from an ecotoxicological point of view. The emphasis was on the potential structure-toxicity dependency of these surface-active ILs in aqueous environment. The median effective concentrations (EC50) were defined for each IL using Vibrio (Aliivibrio) fischeri marine bacteria. Dipalmitoylphosphatidylcholine (DPPC) liposomes were used as biomimetic lipid membranes to study the interactions between the surface-active ILs and the liposomes. The interactions were investigated by following the change in the DPPC phase transition behaviour using differential scanning calorimetry (DSC). Critical micelle concentrations for the ILs were determined to clarify the analysis of the toxicity and the interaction results. Increasing anion alkyl chain length increased the toxicity, whereas branching of the chain decreased the toxicity of the ILs. The toxicity of the ILs in this study was mainly determined by the surface-active anions, while cations induced a minor impact on the toxicity. In the DSC experiments the same trend was observed for all the studied anions, whereas the cations seemed to induce more variable impact on the phase transition behaviour. Toxicity measurements combined with liposome interaction studies can provide a valuable tool for assessing the mechanism of toxicity.

  18. In silico Prediction and Docking of Tertiary Structure of LuxI, an Inducer Synthase of Vibrio fischeri

    Directory of Open Access Journals (Sweden)

    Mohammed Zaghlool Saeed Al-Khayyat

    2016-05-01

    Full Text Available Background: LuxI is a component of the quorum sensing signaling pathway in Vibrio fischeri responsible for the inducer synthesis that is essential for bioluminescence. Methods: Homology modeling of LuxI was carried out using Phyre2 and refined with the GalaxyWEB server. Five models were generated and evaluated by ERRAT, ANOLEA, QMEAN6, and Procheck. Results: Five refined models were generated by the GalaxyWEB server, with Model 4 having the greatest quality based on the QMEAN6 score of 0.732. ERRAT analysis revealed an overall quality of 98.9%, while the overall quality of the initial model was 54%. The mean force potential energy, as analyzed by ANOLEA, were better compared to the initial model. Sterochemical quality estimation by Procheck showed that the refined Model 4 had a reliable structure, and was therefore submitted to the protein model database. Drug Discovery Workbench V.2 was used to screen 2700 experimental compounds from the DrugBank database to identify inhibitors that can bind to the active site between amino acids 24 and 110. Ten compounds with high negative scores were selected as the best in binding. Conclusion: The model produced, and the predicted acteyltransferase binding site, could be useful in modeling homologous sequences from other microorganisms and the design of new antimicrobials.

  19. Predicting the ecotoxicity of ionic liquids towards Vibrio fischeri using genetic function approximation and least squares support vector machine.

    Science.gov (United States)

    Ma, Shuying; Lv, Min; Deng, Fangfang; Zhang, Xiaoyun; Zhai, Honglin; Lv, Wenjuan

    2015-01-01

    Ionic liquids (ILs) are widely used in industrial production for their unique physicochemical properties, and they are even regarded as green solvents. However, the recent study showed ILs might pose a potential risk to aquatic ecosystems. In the present work, the quantitative structure-activity relationship (QSAR) models, including genetic function approximation (GFA) and least squares support vector machine (LSSVM) were developed for predicting the ecotoxicity of ILs towards the marine bacterium Vibrio fischeri based on the descriptors calculated from cations and anions. Five descriptors were selected by GFA and used to develop the linear model. From the discussion of descriptors, the cation structure was the main factor to the toxicity, which mainly depended on the size, lipophilic, and 3D molecular structure of cations. In order to capture the nonlinear nature, the LSSVM model was also built for more accurately predicting the ecotoxicity. The GFA and LSSVM models were performed the rigorous internal and external validation, further verifying these models with excellent robustness and predictive ability. Therefore, both of models can be used for the prediction of the ecotoxicity of newly synthesized and untested ILs, and can provide reference information and theoretical guidance for designing and synthesizing safer and more eco-friendly ILs. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. A DFT-based toxicity QSAR study of aromatic hydrocarbons to Vibrio fischeri: Consideration of aqueous freely dissolved concentration.

    Science.gov (United States)

    Wang, Ying; Yang, Xianhai; Wang, Juying; Cong, Yi; Mu, Jingli; Jin, Fei

    2016-05-05

    In the present study, quantitative structure-activity relationship (QSAR) techniques based on toxicity mechanism and density functional theory (DFT) descriptors were adopted to develop predictive models for the toxicity of alkylated and parent aromatic hydrocarbons to Vibrio fischeri. The acute toxicity data of 17 aromatic hydrocarbons from both literature and our experimental results were used to construct QSAR models by partial least squares (PLS) analysis. With consideration of the toxicity process, the partition of aromatic hydrocarbons between water phase and lipid phase and their interaction with the target biomolecule, the optimal QSAR model was obtained by introducing aqueous freely dissolved concentration. The high statistical values of R(2) (0.956) and Q(CUM)(2) (0.942) indicated that the model has good goodness-of-fit, robustness and internal predictive power. The average molecular polarizability (α) and several selected thermodynamic parameters reflecting the intermolecular interactions played important roles in the partition of aromatic hydrocarbons between the water phase and biomembrane. Energy of the highest occupied molecular orbital (E(HOMO)) was the most influential descriptor which dominated the toxicity of aromatic hydrocarbons through the electron-transfer reaction with biomolecules. The results demonstrated that the adoption of freely dissolved concentration instead of nominal concentration was a beneficial attempt for toxicity QSAR modeling of hydrophobic organic chemicals. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Relationship between acute and chronic toxicity for prevalent organic pollutants in Vibrio fischeri based upon chemical mode of action.

    Science.gov (United States)

    Wang, Xiao H; Fan, Ling Y; Wang, Shuo; Wang, Yue; Yan, Li C; Zheng, Shan S; Martyniuk, Christopher J; Zhao, Yuan H

    2017-09-15

    Chemicals show diverse modes of action (MOAs) in aquatic organisms depending upon acute and chronic toxicity evaluations. Here, toxicity data for Vibrio fischeri involving 52 compounds for acute and chronic toxicity were used to determine the congruence of acute and chronic toxicity for assessing MOAs. Using toxic ratios, most of the compounds categorized into MOAs that included baseline, less inert or reactive compounds with acute toxicity were also categorized as baseline, less inert or reactive compounds with chronic toxicity. However, significantly different toxic effects were observed with acute and chronic toxicity for the reactive and specific-acting compounds. The acute-chronic toxic ratios were smaller and less variable for the baseline and less inert compounds, but were greater and more variable for the reactive and specific-acting compounds. Baseline and less inert compounds share same MOAs, but reactive and specific-acting compounds have different MOAs between acute and chronic toxicity. Bioconcentration processes cannot reach an equilibrium for highly hydrophilic and ionized compounds with short-term exposure, resulting in lower toxicity compared to long-term exposure. Pronounced differences for the antibiotics were not only due to the difference in bioconcentration, but also due to a predicted difference in MOAs during acute and chronic exposures. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A best​ comprehension about the toxicity of phenylsulfonyl carboxylates in Vibrio fischeri using quantitative structure activity/property relationship methods.

    Science.gov (United States)

    de Melo, Eduardo Borges; Martins, João Paulo Athaíde; Miranda, Eduardo Hösel; Ferreira, Márcia Miguel Castro

    2016-03-05

    Aromatic sulfones comprise a class of chemicals used in agrochemical and pharmaceutical industries and as floatation and extractant agents in petrochemical and metallurgy industries. In this study, new QSA(P)R studies were carried out to predict the toxicity against Vibrio fischeri of a set of 52 aromatic sulfones. The same approach was used to evaluate the relationship between these endpoint and the water solubility, another important environmental endpoint. The study resulted in models of good statistical quality and mechanistic interpretation with a possible correlation between the two endpoints, but the toxic effect is also likely to depend on other physicochemical properties. The use of the PLS2, a method not commonly used in QSA(P)R studies, also produced models of greater reliability, and the relationship between the two endpoints was reinforced to some degree. These results are useful for better understanding the process by which these compounds exert their environmental toxicity, thus aiding in the development of industrially useful compounds with less potential environmental damage. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Cr(VI) reduction into Cr(III) as a mechanism to explain the low sensitivity of Vibrio fischeri bioassay to detect chromium pollution.

    Science.gov (United States)

    Fulladosa, Elena; Desjardin, Valérie; Murat, Jean-Claude; Gourdon, Rémy; Villaescusa, Isabel

    2006-10-01

    Vibrio fischeri bacteria, used as a biological target in either acute or chronic toxicity tests, display a low sensitivity to Cr(VI). This phenomenon could be due to the capacity of these bacteria to reduce Cr(VI) into Cr(III). This reducing capacity was found to depend on culture medium composition, pH value, incubation time and the presence of a carbon source. It also depends on the nature of the carbon source, glucose being more efficient than glycerol. This is probably related to differences in bacterial metabolism when given either glucose or glycerol. The thermostable Cr(VI)-reducing activity found in the supernatants of V. fischeri cultures grown on glucose suggests that, under these conditions, the bacteria release non-proteic reducing substances which have not been identified yet.

  4. Antisocial luxO Mutants Provide a Stationary-Phase Survival Advantage in Vibrio fischeri ES114.

    Science.gov (United States)

    Kimbrough, John H; Stabb, Eric V

    2015-12-07

    The squid light organ symbiont Vibrio fischeri controls bioluminescence using two acyl-homoserine lactone pheromone-signaling (PS) systems. The first of these systems to be activated during host colonization, AinS/AinR, produces and responds to N-octanoyl homoserine lactone (C(8)-AHL). We screened activity of a P(ainS)-lacZ transcriptional reporter in a transposon mutant library and found three mutants with decreased reporter activity, low C(8)-AHL output, and other traits consistent with low ainS expression. However, the transposon insertions were unrelated to these phenotypes, and genome resequencing revealed that each mutant had a distinct point mutation in luxO. In the wild type, LuxO is phosphorylated by LuxU and then activates transcription of the small RNA (sRNA) Qrr, which represses ainS indirectly by repressing its activator LitR. The luxO mutants identified here encode LuxU-independent, constitutively active LuxO* proteins. The repeated appearance of these luxO mutants suggested that they had some fitness advantage during construction and/or storage of the transposon mutant library, and we found that luxO* mutants survived better and outcompeted the wild type in prolonged stationary-phase cultures. From such cultures we isolated additional luxO* mutants. In all, we isolated LuxO* allelic variants with the mutations P41L, A91D, F94C, P98L, P98Q, V106A, V106G, T107R, V108G, R114P, L205F, H319R, H324R, and T335I. Based on the current model of the V. fischeri PS circuit, litR knockout mutants should resemble luxO* mutants; however, luxO* mutants outcompeted litR mutants in prolonged culture and had much poorer host colonization competitiveness than is reported for litR mutants, illustrating additional complexities in this regulatory circuit. Our results provide novel insight into the function of LuxO, which is a key component of pheromone signaling (PS) cascades in several members of the Vibrionaceae. Our results also contribute to an increasingly appreciated

  5. Toxicity of 58 substituted anilines and phenols to algae Pseudokirchneriella subcapitata and bacteria Vibrio fischeri: comparison with published data and QSARs.

    Science.gov (United States)

    Aruoja, Villem; Sihtmäe, Mariliis; Dubourguier, Henri-Charles; Kahru, Anne

    2011-09-01

    A congeneric set of 58 substituted anilines and phenols was tested using the 72-h algal growth inhibition assay with Pseudokirchneriella subcapitata and 15-min Vibrio fischeri luminescence inhibition assay. The set contained molecules substituted with one, two or three groups chosen from -chloro, -methyl or -ethyl. For 48 compounds there was no REACH-compatible algal toxicity data available before. The experimentally obtained EC50 values (mg L(-1)) for algae ranged from 1.43 (3,4,5-trichloroaniline) to 197 (phenol) and for V. fischeri from 0.37 (2,3,5-trichlorophenol) to 491 (aniline). Only five of the tested 58 chemicals showed inhibitory effect to algae at concentrations >100 mg L(-1), i.e. could be classified as "not harmful", 32 chemicals as "harmful" (10-100 mg L(-1)) and 21 as "toxic" (1-10 mg L(-1)). The occupied para-position tended to increase toxicity whereas most of the ortho-substituted congeners were the least toxic. As a rule, the higher the number of substituents the higher the hydrophobicity and toxicity. However, in case of both assays, the compounds of similar hydrophobicity showed up to 30-fold different toxicities. There were also assay/organism dependent tendencies: phenols were more toxic than anilines in the V. fischeri assay but not in the algal test. The comparison of the experimental toxicity data to the data available from the literature as well as to QSAR predictions showed that toxicity of phenols to algae can be modeled based on hydrophobicity, whereas the toxicity of anilines to algae as well as toxicity of both anilines and phenols to V. fischeri depended on other characteristics in addition to log K(ow). Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Sensor kinase RscS induces the production of antigenically distinct outer membrane vesicles that depend on the symbiosis polysaccharide locus in Vibrio fischeri.

    Science.gov (United States)

    Shibata, Satoshi; Visick, Karen L

    2012-01-01

    Robust biofilm formation by Vibrio fischeri depends upon activation of the symbiosis polysaccharide (syp) locus, which is achieved by overexpressing the RscS sensor kinase (RscS(+)). Other than the Syp polysaccharide, however, little is known about V. fischeri biofilm matrix components. In other bacteria, biofilms contain polysaccharides, secreted proteins, and outer membrane vesicles (OMVs). Here, we asked whether OMVs are part of V. fischeri biofilms. Transmission electron microscopy revealed OMV-like particles between cells within colonies. In addition, OMVs could be purified from culture supernatants of both RscS(+) and control cells, with the former releasing 2- to 3-fold more OMVs. The increase depended upon the presence of an intact syp locus, as an RscS(+) strain deleted for sypK, which encodes a putative oligosaccharide translocase, exhibited reduced production of OMVs; it also showed a severe defect in biofilm formation. Western immunoblot analyses revealed that the RscS(+) strain, but not the control strain or the RscS(+) sypK mutant, produced a distinct set of nonproteinaceous molecules that could be detected in whole-cell extracts, OMV preparations, and lipopolysaccharide (LPS) extracts. Finally, deletion of degP, which in other bacteria influences OMV production, decreased OMV production and reduced the ability of the cells to form biofilms. We conclude that overexpression of RscS induces OMV production in a manner that depends on the presence of the syp locus and that OMVs produced under these conditions contain antigenically distinct molecules, possibly representing a modified form of lipopolysaccharide (LPS). Finally, our data indicate a correlation between OMV production and biofilm formation by V. fischeri.

  7. Coordination of the arc regulatory system and pheromone-mediated positive feedback in controlling the Vibrio fischeri lux operon.

    Directory of Open Access Journals (Sweden)

    Alecia N Septer

    Full Text Available Bacterial pheromone signaling is often governed both by environmentally responsive regulators and by positive feedback. This regulatory combination has the potential to coordinate a group response among distinct subpopulations that perceive key environmental stimuli differently. We have explored the interplay between an environmentally responsive regulator and pheromone-mediated positive feedback in intercellular signaling by Vibrio fischeri ES114, a bioluminescent bacterium that colonizes the squid Euprymna scolopes. Bioluminescence in ES114 is controlled in part by N-(3-oxohexanoyl-L-homoserine lactone (3OC6, a pheromone produced by LuxI that together with LuxR activates transcription of the luxICDABEG operon, initiating a positive feedback loop and inducing luminescence. The lux operon is also regulated by environmentally responsive regulators, including the redox-responsive ArcA/ArcB system, which directly represses lux in culture. Here we show that inactivating arcA leads to increased 3OC6 accumulation to initiate positive feedback. In the absence of positive feedback, arcA-mediated control of luminescence was only ∼2-fold, but luxI-dependent positive feedback contributed more than 100 fold to the net induction of luminescence in the arcA mutant. Consistent with this overriding importance of positive feedback, 3OC6 produced by the arcA mutant induced luminescence in nearby wild-type cells, overcoming their ArcA repression of lux. Similarly, we found that artificially inducing ArcA could effectively repress luminescence before, but not after, positive feedback was initiated. Finally, we show that 3OC6 produced by a subpopulation of symbiotic cells can induce luminescence in other cells co-colonizing the host. Our results suggest that even transient loss of ArcA-mediated regulation in a sub-population of cells can induce luminescence in a wider community. Moreover, they indicate that 3OC6 can communicate information about both cell density

  8. Comparison of Toxicities to Vibrio fischeri and Fish Based on Discrimination of Excess Toxicity from Baseline Level.

    Science.gov (United States)

    Wang, Xiao H; Yu, Yang; Huang, Tao; Qin, Wei C; Su, Li M; Zhao, Yuan H

    2016-01-01

    Investigations on the relationship of toxicities between species play an important role in the understanding of toxic mechanisms to environmental organisms. In this paper, the toxicity data of 949 chemicals to fish and 1470 chemicals to V. fischeri were used to investigate the modes of action (MOAs) between species. The results show that although there is a positive interspecies correlation, the relationship is poor. Analysis on the excess toxicity calculated from toxic ratios (TR) shows that many chemicals have close toxicities and share the same MOAs between the two species. Linear relationships between the toxicities and octanol/water partition coefficient (log KOW) for baseline and less inert compounds indicate that the internal critical concentrations (CBRs) approach a constant both to fish and V. fischeri for neutral hydrophobic compounds. These compounds share the same toxic mechanisms and bio-uptake processes between species. On the other hand, some hydrophilic compounds exhibit different toxic effects with greatly different log TR values between V. fischeri and fish species. These hydrophilic compounds were identified as reactive MOAs to V. fischeri, but not to fish. The interspecies correlation is improved by adding a hydrophobic descriptor into the correlation equation. This indicates that the differences in the toxic ratios between fish and V. fischeri for these hydrophilic compounds can be partly attributed to the differences of bioconcentration between the two species, rather than the differences of reactivity with the target macromolecules. These hydrophilic compounds may more easily pass through the cell membrane of V. fischeri than the gill and skin of fish, react with the target macromolecules and exhibit excess toxicity. The compounds with log KOW > 7 exhibiting very low toxicity (log TR < -1) to both species indicate that the bioconcentration potential of a chemical plays a very important role in the identification of excess toxicity and MOAs.

  9. Comparison of Toxicities to Vibrio fischeri and Fish Based on Discrimination of Excess Toxicity from Baseline Level.

    Directory of Open Access Journals (Sweden)

    Xiao H Wang

    Full Text Available Investigations on the relationship of toxicities between species play an important role in the understanding of toxic mechanisms to environmental organisms. In this paper, the toxicity data of 949 chemicals to fish and 1470 chemicals to V. fischeri were used to investigate the modes of action (MOAs between species. The results show that although there is a positive interspecies correlation, the relationship is poor. Analysis on the excess toxicity calculated from toxic ratios (TR shows that many chemicals have close toxicities and share the same MOAs between the two species. Linear relationships between the toxicities and octanol/water partition coefficient (log KOW for baseline and less inert compounds indicate that the internal critical concentrations (CBRs approach a constant both to fish and V. fischeri for neutral hydrophobic compounds. These compounds share the same toxic mechanisms and bio-uptake processes between species. On the other hand, some hydrophilic compounds exhibit different toxic effects with greatly different log TR values between V. fischeri and fish species. These hydrophilic compounds were identified as reactive MOAs to V. fischeri, but not to fish. The interspecies correlation is improved by adding a hydrophobic descriptor into the correlation equation. This indicates that the differences in the toxic ratios between fish and V. fischeri for these hydrophilic compounds can be partly attributed to the differences of bioconcentration between the two species, rather than the differences of reactivity with the target macromolecules. These hydrophilic compounds may more easily pass through the cell membrane of V. fischeri than the gill and skin of fish, react with the target macromolecules and exhibit excess toxicity. The compounds with log KOW > 7 exhibiting very low toxicity (log TR < -1 to both species indicate that the bioconcentration potential of a chemical plays a very important role in the identification of excess

  10. Spontaneous phenotypic suppression of GacA-defective Vibrio fischeri is achieved via mutation of csrA and ihfA.

    Science.gov (United States)

    Foxall, Randi L; Ballok, Alicia E; Avitabile, Ashley; Whistler, Cheryl A

    2015-09-16

    Symbiosis defective GacA-mutant derivatives of Vibrio fischeri are growth impaired thereby creating a selective advantage for growth-enhanced spontaneous suppressors. Suppressors were isolated and characterized for effects of the mutations on gacA-mutant defects of growth, siderophore activity and luminescence. The mutations were identified by targeted and whole genome sequencing. Most mutations that restored multiple phenotypes were non-null mutations that mapped to conserved domains in or altered expression of CsrA, a post-transcriptional regulator that mediates GacA effects in a number of bacterial species. These represent an array of unique mutations compared to those that have been described previously. Different substitutions at the same amino acid residue were identified allowing comparisons of effects such as at the R6 residue, which conferred relative differences in luminescence and siderophore levels. The screen revealed residues not previously identified as critical for function including a single native alanine. Most csrA mutations enhanced luminescence more than siderophore activity, which was especially evident for mutations predicted to reduce the amount of CsrA. Although CsrA mutations compensate for many known GacA mutant defects, not all CsrA suppressors restore symbiotic colonization. Phenotypes of a suppressor allele of ihfA that encodes one subunit of the integration host factor (IHF) heteroduplex indicated the protein represses siderophore and activates luminescence in a GacA-independent manner. In addition to its established role in regulation of central metabolism, the CsrA regulator represses luminescence and siderophore as an intermediate of the GacA regulatory hierachy. Siderophore regulation was less sensitive to stoichiometry of CsrA consistent with higher affinity for the targets of this trait. The lack of CsrA null-mutant recovery implied these mutations do not enhance fitness of gacA mutants and alluded to this gene being

  11. Development of a Facile and High-Throughput Bioluminescence Assay Using Vibrio fischeri to Determine the Chronic Toxicity of Contaminated Samples.

    Science.gov (United States)

    Nasuhoglu, Deniz; Westlund, Paul; Isazadeh, Siavash; Neamatallah, Sarah; Yargeau, Viviane

    2017-02-01

    Chronic toxicity testing using the luminescent bacterium, Vibrio fischeri, has recently been demonstrated to be a suitable bioassay for water quality monitoring. The toxicity evaluation is typically based on determining the EC50 at specific time points which may lead to overlooking the dynamic nature of luminescence response and limits information regarding the possible mechanisms of action of target compounds. This study investigated various approaches (standard, integral, and luminescence rate inhibition) to evaluate the chronic toxicity of three target compounds (atrazine, trimethoprim, and acetamiprid) using a 96-well plate based method. The chronic toxicity assay and the methods used for EC50 calculation provided in this work resulted in a high-throughput method of chronic toxicity testing and indicated lower EC50 than the values provided by the standard short term methods, indicating higher toxicity. This study emphasizes the need for additional chronic toxicity testing to further evaluate the toxicity of compounds or unknown samples.

  12. Growth on glucose decreases cAMP-CRP activity while paradoxically increasing intracellular cAMP in the light-organ symbiont Vibrio fischeri.

    Science.gov (United States)

    Colton, Deanna M; Stoudenmire, Julie L; Stabb, Eric V

    2015-09-01

    Proteobacteria often co-ordinate responses to carbon sources using CRP and the second messenger cyclic 3', 5'-AMP (cAMP), which combine to control transcription of genes during growth on non-glucose substrates as part of the catabolite-repression response. Here we show that cAMP-CRP is active and important in Vibrio fischeri during colonization of its host squid Euprymna scolopes. Moreover, consistent with a classical role in catabolite repression, a cAMP-CRP-dependent reporter showed lower activity in cells grown in media amended with glucose rather than glycerol. Surprisingly though, intracellular cAMP levels were higher in glucose-grown cells. Mutant analyses were consistent with predictions that CyaA was responsible for cAMP generation, that the EIIA(Glc) component of glucose transport could enhance cAMP production and that the phophodiesterases CpdA and CpdP consumed intracellular and extracellular cAMP respectively. However, the observation of lower cAMP levels in glycerol-grown cells seemed best explained by changes in cAMP export, via an unknown mechanism. Our data also indicated that cAMP-CRP activity decreased during growth on glucose independently of crp's native transcriptional regulation or cAMP levels. We speculate that some unknown mechanism, perhaps carbon-source-dependent post-translational modulation of CRP, may help control cAMP-CRP activity in V.fischeri. © 2015 John Wiley & Sons Ltd.

  13. Time-dependent hormesis of chemical mixtures: A case study on sulfa antibiotics and a quorum-sensing inhibitor of Vibrio fischeri.

    Science.gov (United States)

    You, Ruirong; Sun, Haoyu; Yu, Yan; Lin, Zhifen; Qin, Mengnan; Liu, Ying

    2016-01-01

    Sulfa antibiotics (SAs) and quorum-sensing inhibitor (QSI) may pose potential ecological risks because mixed using of them has been proposed to inhibit bacteria from generating antibiotic resistance. This study investigated the time-dependent hormesis of single and binary mixtures of QSI and SAs of Vibrio fischeri (V. fischeri) for 0-24 h. Although the low-dose SAs stimulated the expression of LuxR protein, the high-dose SAs could inhibit bacteria growth by competitively binding to dihydropteroate synthase. Moreover, AinR protein was bound to Benzofuran-3(2H)-one (B3O) with low concentration, thus the N-octanoyl homoserine lactone signal molecules (C8) has chance to bind to LuxR protein to promote light emission. The hormesis effect induced by the mixtures could be deduced that SAs promoted the expression of LuxR protein and B3O increases the chance of C8 binding to LuxR. Our findings facilitate new insight into the mechanistic study of hormesis and ecological risks of the chemical mixtures. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. The syp enhancer sequence plays a key role in transcriptional activation by the σ54-dependent response regulator SypG and in biofilm formation and host colonization by Vibrio fischeri.

    Science.gov (United States)

    Ray, Valerie A; Eddy, Justin L; Hussa, Elizabeth A; Misale, Michael; Visick, Karen L

    2013-12-01

    Biofilm formation by Vibrio fischeri is a complex process that requires multiple regulators. One such regulator, the NtrC-like response regulator SypG, controls biofilm formation and host colonization by V. fischeri via its impact on transcription of the symbiosis polysaccharide (syp) locus. SypG is predicted to activate syp transcription by binding to the syp enhancer (SE), a conserved sequence located upstream of four syp promoters. In this study, we performed an in-depth analysis of the sequences necessary for SypG to promote syp transcription and biofilm formation. We found that the SE sequence is necessary for SypG-mediated syp transcription, identified individual bases necessary for efficient activation, and determined that SypG is able to bind to syp promoter regions. We also identified SE sequences outside the syp locus and established that SypG recognizes these sequences as well. Finally, deletion of the SE sequence upstream of sypA led to defects in both biofilm formation and host colonization that could be restored by reintroducing the SE sequence into its native location in the chromosome. This work thus fills in critical gaps in knowledge of the Syp regulatory circuit by demonstrating a role for the SE sequence in SypG-dependent control of biofilm formation and host colonization and by identifying new putative regulon members. It may also provide useful insights into other bacteria, such as Vibrio vulnificus and Vibrio parahaemolyticus, that have syp-like loci and conserved SE sequences.

  15. In silico modelling for predicting the cationic hydrophobicity and cytotoxicity of ionic liquids towards the Leukemia rat cell line, Vibrio fischeri and Scenedesmus vacuolatus based on molecular interaction potentials of ions.

    Science.gov (United States)

    Cho, C-W; Ranke, J; Arning, J; Thöming, J; Preiss, U; Jungnickel, C; Diedenhofen, M; Krossing, I; Stolte, S

    2013-10-01

    In this study we present prediction models for estimating in silico the cationic hydrophobicity and the cytotoxicity (log [1/EC50]) of ionic liquids (ILs) towards the Leukemia rat cell line (IPC-81), the marine bacterium Vibrio fischeri and the limnic green algae Scenedesmus vacuolatus using linear free energy relationship (LFER) descriptors computed by COSMO calculations. The LFER descriptors used for the prediction model (i.e. excess molar refraction (E), dipolarity/polarizability (S), hydrogen-bonding acidity (A), hydrogen-bonding basicity (B) and McGowan volume (V)) were calculated using sub-descriptors (sig2, sig3, HBD3, HBA4, MR, and volume) derived from COSMO-RS, COSMO and OBPROP. With the combination of two solute descriptors (B, V) of the cation we were able to predict cationic hydrophobicity values (log ko ) with r (2) = 0.987 and standard error (SE) = 0.139 log units. By using the calculated log k o values, we were able to deduce a linear toxicity prediction model. In the second prediction study for the cytotoxicity of ILs, analysis of descriptor sensitivity helped us to determine that the McGowan volume (V) terms of the cation was the most important predictor of cytotoxicity and to simplify prediction models for cytotoxicity of ILs towards the IPC-81 (r (2) of 0.778, SE of 0.450 log units), Vibrio fischeri (r (2) of 0.762, SE of 0.529 log units) and Scenedesmus vacuolatus (r (2) of 0.776, SE of 0.825 log units). The robustness and predictivity of the two models for IPC-81 and Vibrio fischeri were checked by comparing the calculated SE and r (2) (coefficient of determination) values of the test set.

  16. Time- and anion-dependent stimulation on triphosphopyridine nucleotide followed by antioxidant responses in Vibrio fischeri after exposure to 1-ethyl-3-methylimidazolium salts.

    Science.gov (United States)

    Yu, ZhenYang; Mo, LingYun; Zhang, Jing; Liu, ShuShen

    2016-11-01

    A toxicity database of over 157 ionic liquids (ILs) was established on Vibrio fischeri (VF). The database contained mainly monotonic concentration-response relationship, and its application in risk assessment was challenged by potential non-monotonic hormetic effects of ILs. In the present study, the hormetic effects of 1-ethyl-3-methylimidazolium salts ([emim]X, X = BF4, Cl and Br) were confirmed on VF, and biochemical explanations were explored in a time-dependent manner. On luminescence, [emim]BF4 showed inhibitory effects compared with the control, and the median effective concentration (EC50) increased from 3.15E-02 to 8.88E-02 mol/L from 0.25 to 24 h. Notably, [emim]BF4 also showed stimulatory effects at 18 h when the maximum stimulation (Emin) was 51.8% higher than the control, and at 24 h when the Emin increased to 120% higher than the control. Compared with [emim]BF4, [emim]Cl had higher EC50 values which increased over time, while it had less maximum stimulation which also increased over time. In results of [emim]Br, there were only inhibitory effects. At the biochemical level, the stimulatory effects of [emim]BF4 and [emim]Cl on triphosphopyridine nucleotide (NADPH) and nicotinamide adenine dinucleotide (NADH) were earlier than those on luminescence. Moreover, NAD(P)H showed stimulation in [emim]Br which did not have hormetic effects on luminescence. Meanwhile, the effects of [emim]X on flavin mononucleotide, adenosine-triphosphate, reactive oxygen species, superoxide dismutase, catalase, reduced glutathione and lipid peroxidases showed consistent time-dependent changes with those on luminescence. The results indicated different roles between NAD(P)H and other biochemical indices, e.g., the antioxidant responses, in the stimulation of [emim]X on luminescence. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Coexpression of luxA and luxB genes of Vibrio fischeri in NIH3T3 mammalian cells and evaluation of its bioluminescence activities.

    Science.gov (United States)

    Tehrani, Golnaz Asaadi; Mirzaahmadi, Sina; Bandehpour, Mojgan; Kazemi, Bahram

    2014-02-01

    Expression of bacterial luciferase enzyme (lux) in eukaryotic cells would provide a new bioreporter system for in vivo imaging and diagnostics technology. In spite of this, until now only a few efforts have been made to express bacterial luciferase enzyme in eukaryotic cells. We attempted to synthesize an expression construct of luxA and luxB genes from Vibrio fischeri. The luxA and luxB genes were cloned into the MCS of pTZ57R via the 5' kpnI, BamHI and BamHI, EcoRI restriction sites to generate pTZ57R/luxA and pTZ57R/luxB respectively, then newly synthesized constructs were cleaved with the same enzymes and respectively cloned into the pcDNA3.1(+) (Hyg) and pcDNA3.1(+) (Neo) expression vectors to create pcDNA3.1(+) (Hyg)/luxA and pcDNA3.1(+) (neo)/luxB. Recombinant constructs were cotransfected to the NIH3T3 cell line. Gene expression was confirmed by reverse transcription-polymerase chain reaction, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting; in addition, bioluminescence characteristics of transfected NIH3T3 cell lines were evaluated by decanal supplement. In conclusion, in the current research, separate vector systems were constructed, which are composed of bacterial luciferase genes (luxA and luxB) that accordingly have not already been reported. These results hold promise toward the potential development of an autonomous light-generating lux reporter system in eukaryotic cells. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Determination of drugs in surface water and wastewater samples by liquid chromatography-mass spectrometry: Methods and preliminary results including toxicity studies with Vibrio fischeri

    Science.gov (United States)

    Farre, M.; Ferrer, I.; Ginebreda, A.; Figueras, M.; Olivella, L.; Tirapu, L.; Vilanova, M.; Barcelo, D.

    2001-01-01

    In the present work a combined analytical method involving toxicity and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) was developed for the determination of pharmaceutical compounds in water samples. The drugs investigated were the analgesics: ibuprofen, ketoprofen, naproxen, and diclofenac, the decomposition product of the acetyl salicylic acid: salicylic acid and one lipid lowering agent, gemfibrozil. The selected compounds are acidic substances, very polar and all of them are analgesic compounds that can be purchased without medical prescription. The developed protocol consisted, first of all, on the use Microtox?? and ToxAlert??100 toxicity tests with Vibrio fischeri for the different pharmaceutical drugs. The 50% effective concentration (EC50) values and the toxicity units (TU) were determined for every compound using both systems. Sample enrichment of water samples was achieved by solid-phase extraction procedure (SPE), using the Merck LiChrolut?? EN cartridges followed by LC-ESI-MS. Average recoveries loading 1 l of samples with pH=2 varied from 69 to 91% and the detection limits in the range of 15-56 ng/l. The developed method was applied to real samples from wastewater and surface-river waters of Catalonia (north-east of Spain). One batch of samples was analyzed in parallel also by High Resolution Gas Chromatography coupled with Mass Spectrometry (HRGC-MS) and the results have been compared with the LC-ESI-MS method developed in this work. ?? 2001 Elsevier Science B.V. All rights reserved.

  19. Rapid in situ toxicity testing with luminescent bacteria Photorhabdus luminescens and Vibrio fischeri adapted to a small portable luminometer.

    Science.gov (United States)

    Masner, Petr; Javůrková, Barbora; Bláha, Luděk

    2017-02-01

    The present study demonstrates development of a rapid testing protocol based on a small portable luminometer using flash kinetic assessment of bacterial bioluminescence. The laboratory comparisons based on six model organic toxicants and two metals showed significant correlations between responses of freshwater bacteria Photorhabdus luminescens and standard marine bacterial species Vibrio fisheri. While P. luminescens was less sensitive in standard arrangements, the responses of both organisms were comparable in the newly introduced portable luminometer setup. The applicability and reproducibility of the portable luminometer protocol was further demonstrated in the assessment of 43 European wastewater effluents that were simultaneously tested for toxicity and analysed for 150 organic and 20 inorganic contaminants grouped into 13 major chemical classes. Clear association between the toxic responses in both compared bacterial species and the elevated levels of inorganic compounds (toxic metals), chlorophenols and benzotriazole anticorrosives was observed. The new protocol with a portable luminometer provides a fast (30 s) response and may be used as a tool for rapid in situ toxicity evaluation of freshwater environmental samples such as effluents.

  20. Qualité de l'eau ? Détermination de l'effet inhibiteur d'échantillons d'eau sur la luminescence de Vibrio fischeri (Essai de bactéries luminescentes) : Partie 3: Méthode utilisant des bactéries lyophilisées

    CERN Document Server

    International Organization for Standardization. Geneva

    1998-01-01

    Qualité de l'eau ? Détermination de l'effet inhibiteur d'échantillons d'eau sur la luminescence de Vibrio fischeri (Essai de bactéries luminescentes) : Partie 3: Méthode utilisant des bactéries lyophilisées

  1. Chronic ecotoxic effects to Pseudomonas putida and Vibrio fischeri, and cytostatic and genotoxic effects to the hepatoma cell line (HepG2) of ofloxacin photo(cata)lytically treated solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.I. [University of Cyprus, Department of Civil and Environmental Engineering, University of Cyprus, 75 Kallipoleos Street, 1678 Nicosia (Cyprus); Nireas International Water Research Center, University of Cyprus (Cyprus); Garcia-Käufer, M. [University Medical Centre Freiburg, Department of Environmental Health Sciences, 115 B, Breisacher Straße, 79106 Freiburg (Germany); Hapeshi, E. [University of Cyprus, Department of Civil and Environmental Engineering, University of Cyprus, 75 Kallipoleos Street, 1678 Nicosia (Cyprus); Nireas International Water Research Center, University of Cyprus (Cyprus); Menz, J. [Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, Scharnhorststraße 1/C13, 21335 Lüneburg (Germany); Kostarelos, K.; Fatta-Kassinos, D. [University of Cyprus, Department of Civil and Environmental Engineering, University of Cyprus, 75 Kallipoleos Street, 1678 Nicosia (Cyprus); Nireas International Water Research Center, University of Cyprus (Cyprus); Kümmerer, K., E-mail: Klaus.Kuemmerer@uni.leuphana.de [Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, Scharnhorststraße 1/C13, 21335 Lüneburg (Germany)

    2013-04-15

    Ofloxacin (OFL), a broad-spectrum and widespread-used photolabile fluoroquinolone, is frequently found in treated wastewaters, aquatic and terrestrial ecosystems leading to increasing concern during the past decades regarding its effects to the environment and human health. The elimination of OFL and other xenobiotics by the application of advanced oxidation processes using photolytic (PL) and photocatalytic (PC) treatments seems promising. However, an integrated assessment scheme is needed, in which, not only the removal of the parent compound, but also the effects of the photo-transformation products (PTPs) are investigated. For this purpose, in the present study, a chronic ecotoxic assessment using representative bacteria of marine and terrestrial ecosystems and a cytostatic and genotoxic evaluation using hepatoma cell line were performed. PL and PC treatments of OFL were applied using UV radiation. The photo-transformation of OFL during the treatments was monitored by DOC measurements and UPLC–MS/MS analysis. The chronic ecotoxicity of OFL and treated samples was evaluated using Pseudomonas putida and Vibrio fischeri; whereas the cytostasis and genotoxicity were estimated by the cytokinesis-block micronucleus assay (CBMN). The main results suggest that photo-transformation of OFL took place during these treatments since the concentration of OFL decreased when the irradiation time increased, as quantified by UPLC–MS/MS analysis, and this was not coupled with an analogous DOC removal. Furthermore, nine compounds were identified as probable PTPs formed through piperazinyl dealkylation and decarboxylation. The ecotoxicity of treated solutions to the bacteria studied decreased while the cytostasis to the hepatoma cell line remained at low levels during both treatments. However, the genotoxicity to the hepatoma cell line demonstrated a different pattern in which treated samples induced a greater number of MNi for the 4–16 min of irradiation (p < 0.05) during

  2. Novel Claycunbic to Eliminate Micropollutants and Vibrio fischeri from Water

    Science.gov (United States)

    Montmorillonite clay (K10) was used as a precursor for the synthesis of a catalytic adsorbent, Claycunbic (Bi/Cu-pillared K10), which was characterized by SEM (EDS), TEM, XRD, BET, TGA and XPS analysis. The catalytic adsorption of cationic dye methylene blue (MB), anionic dye met...

  3. Exopolysaccharide production by Vibrio fischeri, a fouling marine bacterium

    Digital Repository Service at National Institute of Oceanography (India)

    Rodrigues, C.L; Bhosle, N.B.

    stream_size 8 stream_content_type text/plain stream_name Biofouling_4_301.pdf.txt stream_source_info Biofouling_4_301.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  4. Quorum Sensing in the Squid-Vibrio Symbiosis

    Directory of Open Access Journals (Sweden)

    Tim Miyashiro

    2013-08-01

    Full Text Available Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization.

  5. Quorum Sensing in the Squid-Vibrio Symbiosis

    Science.gov (United States)

    Verma, Subhash C.; Miyashiro, Tim

    2013-01-01

    Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization. PMID:23965960

  6. Quorum sensing in the squid-Vibrio symbiosis.

    Science.gov (United States)

    Verma, Subhash C; Miyashiro, Tim

    2013-08-07

    Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization.

  7. Colonization state influences the hemocyte proteome in a beneficial squid-Vibrio symbiosis.

    Science.gov (United States)

    Schleicher, Tyler R; VerBerkmoes, Nathan C; Shah, Manesh; Nyholm, Spencer V

    2014-10-01

    The squid Euprymna scolopes and the luminescent bacterium Vibrio fischeri form a highly specific beneficial light organ symbiosis. Not only does the host have to select V. fischeri from the environment, but it must also prevent subsequent colonization by non-symbiotic microorganisms. Host macrophage-like hemocytes are believed to play a role in mediating the symbiosis with V. fischeri. Previous studies have shown that the colonization state of the light organ influences the host's hemocyte response to the symbiont. To further understand the molecular mechanisms behind this process, we used two quantitative mass-spectrometry-based proteomic techniques, isobaric tags for relative and absolute quantification (iTRAQ) and label-free spectral counting, to compare and quantify the adult hemocyte proteomes from colonized (sym) and uncolonized (antibiotic-treated/cured) squid. Overall, iTRAQ allowed for the quantification of 1,024 proteins with two or more peptides. Thirty-seven unique proteins were determined to be significantly different between sym and cured hemocytes (p value < 0.05), with 20 more abundant proteins and 17 less abundant in sym hemocytes. The label-free approach resulted in 1,241 proteins that were identified in all replicates. Of 185 unique proteins present at significantly different amounts in sym hemocytes (as determined by spectral counting), 92 were more abundant and 93 were less abundant. Comparisons between iTRAQ and spectral counting revealed that 30 of the 37 proteins quantified via iTRAQ exhibited trends similar to those identified by the label-free method. Both proteomic techniques mutually identified 16 proteins that were significantly different between the two groups of hemocytes (p value < 0.05). The presence of V. fischeri in the host light organ influenced the abundance of proteins associated with the cytoskeleton, adhesion, lysosomes, proteolysis, and the innate immune response. These data provide evidence that colonization by V. fischeri

  8. Colonization State Influences the Hemocyte Proteome in a Beneficial Squid–Vibrio Symbiosis*

    Science.gov (United States)

    Schleicher, Tyler R.; VerBerkmoes, Nathan C.; Shah, Manesh; Nyholm, Spencer V.

    2014-01-01

    The squid Euprymna scolopes and the luminescent bacterium Vibrio fischeri form a highly specific beneficial light organ symbiosis. Not only does the host have to select V. fischeri from the environment, but it must also prevent subsequent colonization by non-symbiotic microorganisms. Host macrophage-like hemocytes are believed to play a role in mediating the symbiosis with V. fischeri. Previous studies have shown that the colonization state of the light organ influences the host's hemocyte response to the symbiont. To further understand the molecular mechanisms behind this process, we used two quantitative mass-spectrometry-based proteomic techniques, isobaric tags for relative and absolute quantification (iTRAQ) and label-free spectral counting, to compare and quantify the adult hemocyte proteomes from colonized (sym) and uncolonized (antibiotic-treated/cured) squid. Overall, iTRAQ allowed for the quantification of 1,024 proteins with two or more peptides. Thirty-seven unique proteins were determined to be significantly different between sym and cured hemocytes (p value < 0.05), with 20 more abundant proteins and 17 less abundant in sym hemocytes. The label-free approach resulted in 1,241 proteins that were identified in all replicates. Of 185 unique proteins present at significantly different amounts in sym hemocytes (as determined by spectral counting), 92 were more abundant and 93 were less abundant. Comparisons between iTRAQ and spectral counting revealed that 30 of the 37 proteins quantified via iTRAQ exhibited trends similar to those identified by the label-free method. Both proteomic techniques mutually identified 16 proteins that were significantly different between the two groups of hemocytes (p value < 0.05). The presence of V. fischeri in the host light organ influenced the abundance of proteins associated with the cytoskeleton, adhesion, lysosomes, proteolysis, and the innate immune response. These data provide evidence that colonization by V. fischeri

  9. Vibrio and Pregnancy

    Science.gov (United States)

    ... 2013. Vibrio Infection. [Accessed January 2015]. Available at URL: http: / / www. cdc. gov/ vibrio/ index. html Centers for ... 2013. Vibrio parahaemolyticus. [Accessed January 2015]. Available at URL: http: / / www. cdc. gov/ vibrio/ vibriop. html Centers for ...

  10. Mannitol is essential for the development of stress-resistant ascospores in Neosartorya fischeri (Aspergillus fischeri)

    NARCIS (Netherlands)

    Wyatt, T T; van Leeuwen, M R; Dijksterhuis, J; Wosten, Han

    2014-01-01

    The polyol mannitol is one of the main compatible solutes in Neosartorya fischeri and accumulates in conidia and ascospores. Here, it is shown that biosynthesis of mannitol in N. fischeri mainly depends on mannitol 1-phosphate dehydrogenase (MpdA). Reporter studies and qPCR analysis demonstrated

  11. Mannitol is essential for the development of stress-resistant ascospores in Neosartorya fischeri (Aspergillus fischeri)

    NARCIS (Netherlands)

    Wyatt, T T; van Leeuwen, M R; Wösten, H A B; Dijksterhuis, J

    The polyol mannitol is one of the main compatible solutes in Neosartorya fischeri and accumulates in conidia and ascospores. Here, it is shown that biosynthesis of mannitol in N. fischeri mainly depends on mannitol 1-phosphate dehydrogenase (MpdA). Reporter studies and qPCR analysis demonstrated

  12. Screening for antibacterial activity in 72 species of wood-colonizing fungi by the Vibrio fisheri bioluminescence method.

    Science.gov (United States)

    Zrimec, Maja Berden; Zrimec, Alexis; Slanc, Petra; Kac, Javor; Kreft, Samo

    2004-01-01

    Resistance of pathogenic bacteria to antibiotics leads scientists to discover new antibacterial drugs. Ninety samples of wood-colonizing fungi were cultivated on agar plates, and their extracts tested for antibacterial activity using the Vibrio fischeri bioluminescence test. Two fungi species, Serpula lacrymans and Nectria vilior, were found to be a potential new source of thermostable antibiotics. Vibrio fischeri bioluminescence test was found to be a useful method for antibacterial activity screening from the samples of natural origin. Copyright 2004 WILEY-VCH Verlag GmbH & Co.

  13. Anticonvulsant Activity Of Diospyros fischeri Root Extracts | Moshi ...

    African Journals Online (AJOL)

    These results provide evidence for the potential of D. fischeri extracts to treat absence seizures, especially given their seemingly innocuous nature. Keywords: Diospyros fischeri; Pentylenetetrazole; Anticonvulsant activity; Brine shrimp toxicity. African Journal of Traditional, Complementary and Alternative Medicines Vol.

  14. Elongation of exogenous fatty acids by the bioluminescent bacterium Vibrio harveyi.

    OpenAIRE

    Byers, D M

    1989-01-01

    Bioluminescent bacteria require myristic acid (C14:0) to produce the myristaldehyde substrate of the light-emitting luciferase reaction. Since both endogenous and exogenous C14:0 can be used for this purpose, the metabolism of exogenous fatty acids by luminescent bacteria has been investigated. Both Vibrio harveyi and Vibrio fischeri incorporated label from [1-14C]myristic acid (C14:0) into phospholipid acyl chains as well as into CO2. In contrast, Photobacterium phosphoreum did not exhibit p...

  15. Microencapsulated Aliivibrio fischeri in Alginate Microspheres for Monitoring Heavy Metal Toxicity in Environmental Waters

    Directory of Open Access Journals (Sweden)

    Dedi Futra

    2014-12-01

    Full Text Available In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri encapsulated in alginate microspheres is described. Cu(II, Cd(II, Pb(II, Zn(II, Cr(VI, Co(II, Ni(II, Ag(I and Fe(II were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD range of 2.4–5.7% (n = 8. The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD for Cu(II (6.40 μg/L, Cd(II (1.56 μg/L, Pb(II (47 μg/L, Ag(I (18 μg/L than Zn(II (320 μg/L, Cr(VI (1,000 μg/L, Co(II (1700 μg/L, Ni(II (2800 μg/L, and Fe(III (3100 μg/L. Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples.

  16. Microencapsulated Aliivibrio fischeri in alginate microspheres for monitoring heavy metal toxicity in environmental waters.

    Science.gov (United States)

    Futra, Dedi; Heng, Lee Yook; Surif, Salmijah; Ahmad, Asmat; Ling, Tan Ling

    2014-12-05

    In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri) encapsulated in alginate microspheres is described. Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(II) were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD) range of 2.4-5.7% (n = 8). The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD) for Cu(II) (6.40 μg/L), Cd(II) (1.56 μg/L), Pb(II) (47 μg/L), Ag(I) (18 μg/L) than Zn(II) (320 μg/L), Cr(VI) (1,000 μg/L), Co(II) (1700 μg/L), Ni(II) (2800 μg/L), and Fe(III) (3100 μg/L). Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS) and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples.

  17. Oil effect in freshly spiked marine sediment on Vibrio fischeri, Corophium volutator and Echinocardium cordatum

    NARCIS (Netherlands)

    Brils, J.M.; Huwer, S.L.; Kater, B.J.; Schout, P.G.; Harmsen, J.; Delvigne, G.A.L.; Scholten, M.C.T.

    2002-01-01

    The purpose of this study was to provide data to be used in The Netherlands for development of ecotoxicologically based quality criteria for oil-contaminated sediments and dredged material. In addition, the relation of toxicity to specific oil boiling-point fraction ranges was explored. Natural

  18. Phototransformation of sulfamethoxazole under simulated sunlight: Transformation products and their antibacterial activity toward Vibrio fischeri

    Energy Technology Data Exchange (ETDEWEB)

    Gmurek, M., E-mail: marta.gmurek@p.lodz.pl [Lodz University of Technology, Faculty of Process & Environmental Engineering, Department of Bioprocess Engineering, Wolczanska 213, 90-924 Lodz (Poland); Horn, H.; Majewsky, M. [Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany)

    2015-12-15

    Sulfamethoxazole (SMX) is a bacteriostatic antibiotic ubiquitously found in the aquatic environment. Since conventional biological wastewater treatment is not efficient to remove SMX, photolysis in natural waters can represent an important transformation pathway. It was recently shown that SMX transformation products can retain antibiotic activity. Therefore, it is crucial to better understand photochemical processes occurring in natural water just as the formation of active transformation products (TPs). During long-term SMX photolysis experiments (one week), nine TPs were identified by reference standards. Moreover, five further TPs of photodecomposition of SMX were found. For the first time, a TP with m/z 271 [M + H]{sup +} was observed during photolysis and tentatively confirmed as 4,x-dihydroxylated SMX. The DOC mass balance clearly showed that only around 5 to 10% were mineralized during the experiment emphasizing the need to elucidate the fate of TPs. Bacterial bioassays confirmed that the mixture retains its antibiotic toxicity toward luminescence (24 h) and that there is no change over the treatment time on EC{sub 50}. In contrast, growth inhibition activity was found to slightly decrease over the irradiation time. However, this decrease was not proportional to the transformation of the parent compound SMX. - Highlights: • During SMX photolysis experiments, nine TPs were identified by reference standards. • Six further TPs of SMX phototransformation were found. • A TP with a m/z 271 was tentatively confirmed as 4-,x-dihydroxylated SMX. • The mixture exhibitsluminescence inhibition without changes over the irradiation time. • Growth inhibition was found to slightly decrease over the irradiation time.

  19. BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, LEPOMIS MACROCHIRUS, AND VIBRIO FISCHERI TO TOLUENE

    Science.gov (United States)

    The research presented here is a continuation of work designed to further the science of available and developing online toxicity monitors(OTMs) and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system. Source waters o...

  20. Response of Vibrio fischeri to repeated exposures over time in an Online Toxicity Monitor

    Science.gov (United States)

    Online Toxicity Monitors have been developed to provide continuous, time-relevant information regarding water quality. These systems measure a physiological or behavioral response of a sentinel organism to changes water quality. One such system, the Microlan Toxcontrol, is base...

  1. Anticonvulsant activity of extracts of Diospyros fischeri stem bark ...

    African Journals Online (AJOL)

    Evaluation of extracts of Diospyros fischeri Gurke (Ebenaceae), which is used traditionally for the treatment of epilepsy shows that the aqueous extract of the tem bark has no effect against picrotoxin induced convulsions in mice. However, an 80% ethanol extract of the bark caused dose-dependent suppression of ...

  2. 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 ...

  3. 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...... analytical and bioinformatics tools will enable the most accurate species identification through genomic computational analysis. This endeavour will culminate in the birth of the online genomic taxonomy whereby researchers and end-users of taxonomy will be able to identify their isolates through a web...

  4. 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

  5. The dual nature of haemocyanin in the establishment and persistence of the squid–vibrio symbiosis

    Science.gov (United States)

    Kremer, Natacha; Schwartzman, Julia; Augustin, René; Zhou, Lawrence; Ruby, Edward G.; Hourdez, Stéphane; McFall-Ngai, Margaret J.

    2014-01-01

    We identified and sequenced from the squid Euprymna scolopes two isoforms of haemocyanin that share the common structural/physiological characteristics of haemocyanin from a closely related cephalopod, Sepia officinalis, including a pronounced Bohr effect. We examined the potential roles for haemocyanin in the animal's symbiosis with the luminous bacterium Vibrio fischeri. Our data demonstrate that, as in other cephalopods, the haemocyanin is primarily synthesized in the gills. It transits through the general circulation into other tissues and is exported into crypt spaces that support the bacterial partner, which requires oxygen for its bioluminescence. We showed that the gradient of pH between the circulating haemolymph and the matrix of the crypt spaces in adult squid favours offloading of oxygen from the haemocyanin to the symbionts. Haemocyanin is also localized to the apical surfaces and associated mucus of a juvenile-specific epithelium on which the symbionts gather, and where their specificity is determined during the recruitment into the association. The haemocyanin has an antimicrobial activity, which may be involved in this enrichment of V. fischeri during symbiont initiation. Taken together, these data provide evidence that the haemocyanin plays a role in shaping two stages of the squid–vibrio partnership. PMID:24807261

  6. The dual nature of haemocyanin in the establishment and persistence of the squid-vibrio symbiosis.

    Science.gov (United States)

    Kremer, Natacha; Schwartzman, Julia; Augustin, René; Zhou, Lawrence; Ruby, Edward G; Hourdez, Stéphane; McFall-Ngai, Margaret J

    2014-06-22

    We identified and sequenced from the squid Euprymna scolopes two isoforms of haemocyanin that share the common structural/physiological characteristics of haemocyanin from a closely related cephalopod, Sepia officinalis, including a pronounced Bohr effect. We examined the potential roles for haemocyanin in the animal's symbiosis with the luminous bacterium Vibrio fischeri. Our data demonstrate that, as in other cephalopods, the haemocyanin is primarily synthesized in the gills. It transits through the general circulation into other tissues and is exported into crypt spaces that support the bacterial partner, which requires oxygen for its bioluminescence. We showed that the gradient of pH between the circulating haemolymph and the matrix of the crypt spaces in adult squid favours offloading of oxygen from the haemocyanin to the symbionts. Haemocyanin is also localized to the apical surfaces and associated mucus of a juvenile-specific epithelium on which the symbionts gather, and where their specificity is determined during the recruitment into the association. The haemocyanin has an antimicrobial activity, which may be involved in this enrichment of V. fischeri during symbiont initiation. Taken together, these data provide evidence that the haemocyanin plays a role in shaping two stages of the squid-vibrio partnership.

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

    Digital Repository Service at National Institute of Oceanography (India)

    Ramamurthy, T.; Nair, G.B.

    or indirectly via contaminated food and water. Food-borne Vibrio infections tend to occur more frequently in developed countries while transmission of Vibrio infections in developing countries is, by and large, water-borne. Further, the magnitude of food... and pandemics mainly due to poor water supply and personal hygiene. The other important and most common seafood-borne halophilic Vibrio is V. parahaemolyticus. Since its discovery in 1953 (Fujino et al., 1953), many aspects on this pathogen were explored...

  8. Shaping the microenvironment: evidence for the influence of a host galaxin on symbiont acquisition and maintenance in the squid-Vibrio symbiosis.

    Science.gov (United States)

    Heath-Heckman, Elizabeth A C; Gillette, Amani A; Augustin, René; Gillette, Miles X; Goldman, William E; McFall-Ngai, Margaret J

    2014-12-01

    Most bacterial species make transitions between habitats, such as switching from free living to symbiotic niches. We provide evidence that a galaxin protein, EsGal1, of the squid Euprymna scolopes participates in both: (i) selection of the specific partner Vibrio fischeri from the bacterioplankton during symbiosis onset and, (ii) modulation of V. fischeri growth in symbiotic maintenance. We identified two galaxins in transcriptomic databases and showed by quantitative reverse-transcriptase polymerase chain reaction that one (esgal1) was dominant in the light organ. Further, esgal1 expression was upregulated by symbiosis, a response that was partially achieved with exposure to symbiont cell-envelope molecules. Confocal immunocytochemistry of juvenile animals localized EsGal1 to the apical surfaces of light-organ epithelia and surrounding mucus, the environment in which V. fischeri cells aggregate before migration into the organ. Growth assays revealed that one repeat of EsGal1 arrested growth of Gram-positive bacterial cells, which represent the cell type first 'winnowed' during initial selection of the symbiont. The EsGal1-derived peptide also significantly decreased the growth rate of V. fischeri in culture. Further, when animals were exposed to an anti-EsGal1 antibody, symbiont population growth was significantly increased. These data provide a window into how hosts select symbionts from a rich environment and govern their growth in symbiosis. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  9. Autecology of Vibrio vulnificus and Vibrio parahaemolyticus in tropical waters

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, S.; Lugo, T.; Hazen, T.C. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico)

    1988-12-31

    Water and shellfish samples collected from estuaries, mangroves, and beaches along the coast of Puerto Rico were examined for Vibrio vulnificus and Vibrio parahaemolyticus. An array of water quality parameters were also measured simultaneous with bacteria sampling. Both species of vibrio were associated with estuary and mangrove locations, and neither was isolated from sandy beaches. Densities of V. vulnificus were negatively correlated with salinity, 10--15 ppt being optimal. V. parahaemolyticus was isolated from sites with salinities between 20 and 35 ppt, the highest densities occurring at 20 ppt. Densities of Vibrio spp. and V. parahaemolyticus for a tropical estuary surpassed those reported for temperate estuaries by several orders of magnitude. Both densities of total Vibrio spp. and V. parahaemolyticus in the water were directly related to densities of fecal coliforms, unlike V. vulnificus. The incidence of ONPG(+) strains among sucrose({minus}) Vibrio spp. served as an indicator of the frequency of V. vulnificus in this group. More than 63% of the V. vulnificus isolated were pathogenic. V. vulnificus and V. parahaemolyticus occupy clearly separate niches within the tropical estuarine-marine ecosystem.

  10. Late Winter Population and Distribution of Spectacled Eiders (Somateria fischeri) in the Bering Sea

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We conducted aerial surveys in the northern Bering Sea in late winter 1995, 1996 and 1997 to estimate the population of spectacled eiders (Somateria fischeri)...

  11. Microarray analysis of Neosartorya fischeri using different carbon sources, petroleum asphaltenes and glucose-peptone

    Directory of Open Access Journals (Sweden)

    Edna L. Hernández-López

    2015-09-01

    Here we describe experimental procedures and methods about our dataset (NCBI GEO accession number GSE68146 and describe the data analysis to identify different expression levels in N. fischeri using this recalcitrant carbon source.

  12. Understanding the Role of Host Hemocytes in a Squid/Vibrio Symbiosis Using Transcriptomics and Proteomics

    Directory of Open Access Journals (Sweden)

    Andrew J. Collins

    2012-05-01

    Full Text Available The symbiosis between the squid, Euprymna scolopes, and the bacterium, Vibrio fischeri, serves as a model for understanding interactions between beneficial bacteria and animal hosts. The establishment and maintenance of the association is highly specific and depends on the selection of V. fischeri and exclusion of non-symbiotic bacteria from the environment. Current evidence suggests that the host’s cellular innate immune system, in the form of macrophage-like hemocytes, helps to mediate host tolerance of V. fischeri. To begin to understand the role of hemocytes in this association, we analyzed these cells by high-throughput 454 transcriptomic and liquid chromatography/ tandem mass spectrometry (LC-MS/MS proteomic analyses. 454 high-throughput sequencing produced 650,686 reads totaling 279.9 Mb while LC-MS/MS analyses of circulating hemocytes putatively identified 702 unique proteins. Several receptors involved with the recognition of microbial associated molecular patterns (MAMPs were identified. Among these was a complete open reading frame (ORF to a putative peptidoglycan recognition protein (EsPGRP5 that has conserved residues for amidase activity. Assembly of the hemocyte transcriptome showed EsPGRP5 had high coverage, suggesting it is among the 5% most abundant transcripts in circulating hemocytes. Other transcripts and proteins identified included members of the conserved NFκB signaling pathway, putative members of the complement pathway, the carbohydrate binding protein galectin, and cephalotoxin. Quantitative PCR of complement-related genes, cephalotoxin, EsPGRP5, and a nitric oxide synthase showed differential expression in circulating hemocytes isolated from adult squid with colonized light organs compared to those for which the symbionts were removed. These data suggest that the presence of the symbiont influences gene expression of the cellular innate immune system of the host.

  13. Reclassification of the larval pathogen for marine bivalves Vibrio tubiashii subsp. europaeus as Vibrio europaeus sp. nov.

    Science.gov (United States)

    Dubert, Javier; Romalde, Jesús L; Spinard, Edward J; Nelson, David R; Gomez-Chiarri, Marta; Barja, Juan L

    2016-11-01

    The Orientalis clade has a relevant significance for bivalve aquaculture since it includes the pathogens Vibrio bivalvicida, Vibrio tubiashii subsp. tubiashii and Vibrio tubiashii subsp. europaeus. However, the previous taxonomic description of the subspecies of V. tubiashii shows some incongruities that should be emended. In the genomic age, the comparison between genome assemblies is the key to clarify the taxonomic position of both subspecies. With this purpose, we have tested the ability of multilocus sequence analysis based on eight housekeeping gene sequences (gapA, gyrB, ftsZ, mreB, pyrH, recA, rpoA and topA), different in silico genome-to-genome comparisons, chemotaxonomic features and phenotypic traits to reclassify the subspecies V. tubiashii subsp. europaeus within the Orientalis clade. This polyphasic approach clearly demonstrated that this subspecies is phylogenetically and phenotypically distinct from V. tubiashii and should be elevated to the rank of species as Vibrio europaeus sp. nov. This reclassification allows us to update the Orientalis clade (V. bivalvicida,V. brasiliensis, V. crosai, V. hepatarius, V. orientalis, V. sinaloensis, V. tubiashii and V. europaeus sp. nov.) and reconstruct a better phylogeny of the genus Vibrio. An emended description of V. tubiashii is provided. Finally, the proposed novel species is represented by emergent bivalve pathogens [type strain PP-638T (=CECT 8136T=DSM 27349T), PP2-843 and 07/118 T2] responsible for high mortalities in Spanish and French hatcheries.

  14. Canine visceral leishmaniasis in the metropolitan area of São Paulo: Pintomyia fischeri as potential vector of Leishmania infantum

    Directory of Open Access Journals (Sweden)

    Galvis-Ovallos Fredy

    2017-01-01

    Full Text Available American visceral leishmaniasis is a zoonosis caused by Leishmania infantum and transmitted mainly by Lutzomyia longipalpis. However, canine cases have been reported in the absence of this species in the Greater São Paulo region, where Pintomyia fischeri and Migonemyia migonei are the predominant species. This raises the suspicion that they could be acting as vectors. Therefore, this study sought to investigate specific vector capacity parameters of these species and to compare them with those of Lu. longipalpis s.l. Among these parameters the blood feeding rate, the survival, and the susceptibility to the development of Le. infantum were evaluated for the three species, and the attractiveness of dogs to Pi. fischeri and Mg. migonei was evaluated. The estimated interval between blood meals was shorter for Lu. longipalpis s.l, followed by Pi. fischeri and Mg. migonei. The infection rate with Le. infantum flagellates in Lu. longipalpis was 9.8%, in Pi. fischeri 4.8%, and in Mg. migonei nil. The respective infective life expectancies (days of Lu. longipalpis, Mg. migonei, and Pi. fischeri were 2.4, 1.94, and 1.68. Both Pi. fischeri and Mg. migonei were captured in the kennel with a predominance (95% of Pi. fischeri. Considering the great attractiveness of dogs to Pi. fischeri, its susceptibility to infection by Le. infantum, infective life expectancies, and predominance in Greater São Paulo, this study presents evidence of Pi. fischeri as a potential vector of this parasite in the region.

  15. Toxicity Screening of Hydrolyzed H, HD, and HT using the Bioluminescent Marine Bacterium, Vibrio Fischeri, by Means of Microtox Assay

    National Research Council Canada - National Science Library

    Haley, Mark V; Checkai, Ronald T

    2006-01-01

    .... The mineralization of HD through hot water hydrolysis with subsequent neutralization using NaOH, followed by biodegradation, has been demonstrated to be an effective technology at the Aberdeen...

  16. Functionality and prevalence of trehalose-based oligosaccharides as novel compatible solutes in ascospores of Neosartorya fischeri (Aspergillus fischeri) and other fungi

    NARCIS (Netherlands)

    Wyatt, Timon T; van Leeuwen, M Richard; Golovina, Elena A; Hoekstra, Folkert A; Kuenstner, Eric J; Palumbo, Edward A; Snyder, Nicole L; Visagie, Cobus; Verkennis, Alex; Hallsworth, John E; Wösten, Han A B; Dijksterhuis, Jan

    Ascospores of Neosartorya, Byssochlamys and Talaromyces can be regarded as the most stress-resistant eukaryotic cells. They can survive exposure at temperatures as high as 85°C for 100 min or more. Neosartorya fischeri ascospores are more viscous and more resistant to the combined stress of heat and

  17. Development of a More Sensitive and Specific Chromogenic Agar Medium for the Detection of Vibrio parahaemolyticus and Other Vibrio Species.

    Science.gov (United States)

    Yeung, Marie; Thorsen, Trevor

    2016-11-08

    Foodborne infections in the US caused by Vibrio species have shown an upward trend. In the genus Vibrio, V. parahaemolyticus is responsible for the majority of Vibrio-associated infections. Thus, accurate differentiation among Vibrio spp. and detection of V. parahaemolyticus is critically important to ensure the safety of our food supply. Although molecular techniques are increasingly common, culture-depending methods are still routinely done and they are considered standard methods in certain circumstances. Hence, a novel chromogenic agar medium was tested with the goal of providing a better method for isolation and differentiation of clinically relevant Vibrio spp. The protocol compared the sensitivity, specificity and detection limit for the detection of V. parahaemolyticus between the new chromogenic medium and a conventional medium. Various V. parahaemolyticus strains (n=22) representing diverse serotypes and source of origins were used. They were previously identified by Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC), and further verified in our laboratory by tlh-PCR. In at least four separate trials, these strains were inoculated on the chromogenic agar and thiosulfate-citrate-bile salts-sucrose (TCBS) agar, which is the recommended medium for culturing this species, followed by incubation at 35-37 °C for 24-96 hr. Three V. parahaemolyticus strains (13.6%) did not grow optimally on TCBS, nonetheless exhibited green colonies if there was growth. Two strains (9.1%) did not yield the expected cyan colonies on the chromogenic agar. Non-V. parahaemolyticus strains (n=32) were also tested to determine the specificity of the chromogenic agar. Among these strains, 31 did not grow or exhibited other colony morphologies. The mean recovery of V. parahaemolyticus on the chromogenic agar was ~96.4% relative to tryptic soy agar supplemented with 2% NaCl. In conclusion, the new chromogenic agar is an effective medium to detect V

  18. Zoonose Vibrio vulnificus: meldingsplicht raadzaam

    NARCIS (Netherlands)

    Dijkstra, A.; Haenen, O.L.M.; Moller, L.

    2010-01-01

    Op de lijst van meldingsplichtige infectieziekten komen een aantal zoönosen voor, zoals pest, rabiës en leptospirose. De relatief onbekende zoönotische Vibrio vulnificus valt opmerkelijk genoeg niet onder de meldingsplichtige infectieziekten. Juist vanwege het zeer agressieve beloop van een

  19. 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.

  20. Elongation of exogenous fatty acids by the bioluminescent bacterium Vibrio harveyi.

    Science.gov (United States)

    Byers, D M

    1989-01-01

    Bioluminescent bacteria require myristic acid (C14:0) to produce the myristaldehyde substrate of the light-emitting luciferase reaction. Since both endogenous and exogenous C14:0 can be used for this purpose, the metabolism of exogenous fatty acids by luminescent bacteria has been investigated. Both Vibrio harveyi and Vibrio fischeri incorporated label from [1-14C]myristic acid (C14:0) into phospholipid acyl chains as well as into CO2. In contrast, Photobacterium phosphoreum did not exhibit phospholipid acylation or beta-oxidation using exogenous fatty acids. Unlike Escherichia coli, the two Vibrio species can directly elongate fatty acids such as octanoic (C8:0), lauric (C12:0), and myristic acid, as demonstrated by radio-gas liquid chromatography. The induction of bioluminescence in late exponential growth had little effect on the ability of V. harveyi to elongate fatty acids, but it did increase the amount of C14:0 relative to C16:0 labeled from [14C]C8:0. This was not observed in a dark mutant of V. harveyi that is incapable of supplying endogenous C14:0 for luminescence. Cerulenin preferentially decreased the labeling of C16:0 and of unsaturated fatty acids from all 14C-labeled fatty acid precursors as well as from [14C]acetate, suggesting that common mechanisms may be involved in elongation of fatty acids from endogenous and exogenous sources. Fatty acylation of the luminescence-related synthetase and reductase enzymes responsible for aldehyde synthesis exhibited a chain-length preference for C14:0, which also was indicated by reverse-phase thin-layer chromatography of the acyl groups attached to these enzymes. The ability of V. harveyi to activate and elongate exogenous fatty acids may be related to an adaptive requirement to metabolize intracellular C14:0 generated by the luciferase reaction during luminescence development.

  1. Elongation of exogenous fatty acids by the bioluminescent bacterium Vibrio harveyi

    Energy Technology Data Exchange (ETDEWEB)

    Byers, D.M.

    1989-01-01

    Bioluminescent bacteria require myristic acid (C14:0) to produce the myristaldehyde substrate of the light-emitting luciferase reaction. Since both endogenous and exogenous C14:0 can be used for this purpose, the metabolism of exogenous fatty acids by luminescent bacteria has been investigated. Both Vibrio harveyi and Vibrio fischeri incorporated label from (1-14C)myristic acid (C14:0) into phospholipid acyl chains as well as into CO2. In contrast, Photobacterium phosphoreum did not exhibit phospholipid acylation or beta-oxidation using exogenous fatty acids. Unlike Escherichia coli, the two Vibrio species can directly elongate fatty acids such as octanoic (C8:0), lauric (C12:0), and myristic acid, as demonstrated by radio-gas liquid chromatography. The induction of bioluminescence in late exponential growth had little effect on the ability of V. harveyi to elongate fatty acids, but it did increase the amount of C14:0 relative to C16:0 labeled from (14C)C8:0. This was not observed in a dark mutant of V. harveyi that is incapable of supplying endogenous C14:0 for luminescence. Cerulenin preferentially decreased the labeling of C16:0 and of unsaturated fatty acids from all 14C-labeled fatty acid precursors as well as from (14C)acetate, suggesting that common mechanisms may be involved in elongation of fatty acids from endogenous and exogenous sources. Fatty acylation of the luminescence-related synthetase and reductase enzymes responsible for aldehyde synthesis exhibited a chain-length preference for C14:0, which also was indicated by reverse-phase thin-layer chromatography of the acyl groups attached to these enzymes. The ability of V. harveyi to activate and elongate exogenous fatty acids may be related to an adaptive requirement to metabolize intracellular C14:0 generated by the luciferase reaction during luminescence development.

  2. Antiadhesive activity of poly-hydroxy butyrate biopolymer from a marine Brevibacterium casei MSI04 against shrimp pathogenic vibrios.

    Science.gov (United States)

    Kiran, George Seghal; Lipton, Anuj Nishanth; Priyadharshini, Sethu; Anitha, Kumar; Suárez, Lucia Elizabeth Cruz; Arasu, Mariadhas Valan; Choi, Ki Choon; Selvin, Joseph; Al-Dhabi, Naif Abdullah

    2014-08-13

    Vibrio pathogens are causative agents of mid-culture outbreaks, and early mortality syndrome and secondary aetiology of most dreadful viral outbreaks in shrimp aquaculture. Among the pathogenic vibrios group, Vibrio alginolyticus and V. harveyi are considered as the most significant ones in the grow-out ponds of giant black tiger shrimp Penaeus monodon in India. Use of antibiotics was banned in many countries due to the emergence of antibiotic-resistant strains and accumulation of residual antibiotics in harvested shrimp. There is an urgent need to consider the use of alternative antibiotics for the control of vibriosis in shrimp aquaculture. Biofilm formation is a pathogenic and/or establishment mechanism of Vibrio spp. This study aims to develop novel safe antibiofilm and/or antiadhesive process using PHB to contain vibrios outbreaks in shrimp aquaculture. In this study a poly-hydroxy butyrate (PHB) polymer producing bacterium Brevibacterium casei MSI04 was isolated from a marine sponge Dendrilla nigra and production of PHB was optimized under submerged-fermentation (SmF) conditions. The effect of carbon, nitrogen and mineral sources on PHB production and enhanced production of PHB by response surface methods were demonstrated. The maximum PHB accumulation obtained was 6.74 g/L in the optimized media containing 25 g/L starch as carbon source, 96 h of incubation, 35°C and 3% NaCl. The highest antiadhesive activity upto 96% was recorded against V. vulnificus, and V. fischeri, followed by 92% against V. parahaemolyticus and V. alginolyticus and 88% inhibition was recorded against V. harveyi. In this study, a thermostable biopolymer was chemically characterized as PHB based on 1HNMR spectra, FT-IR and GC-MS spectra. The NMR spectra revealed that the polymer was an isocratic homopolymer and it also confirmed that the compound was PHB. The antiadhesive activity of PHB was determined in microtitre plate assay and an effective concentration (EC) of PHB (200

  3. Identification of Vibrio spp. with a set of dichotomous keys.

    Science.gov (United States)

    Noguerola, I; Blanch, A R

    2008-07-01

    To define a binary biochemical key for the identification of all recognized Vibrio spp. A matrix of phenotypical results was developed based on the previous taxonomical studies and the first description manuscripts. A unification of results from various sources was also performed to integrate different taxonomical studies within the same data matrix. Established criteria for selecting the optimal set of tests yielded the highest discrimination, as well as the lowest number of tests. An initial identification key was defined using arginine dihydrolase, lysine decarboxylase and ornithine decarboxylase tests, as well as defining eight different clusters. This key leads each cluster to a secondary key for species identification. Most of Vibrio spp. presented an identification threshold of 100%. A new set of biochemical keys has been determined provides a scheme for the rapid identification of clinical and environmental species of Vibrio. No more than 14 are needed for even the most complicated identifications. This newly defined set of keys updates and improves similar findings published in previous studies. These biochemical keys are designed for use in routine applications, particularly in environmental and clinical studies involving a high number of isolates.

  4. Occurrences of pathogenic Vibrio parahaemolyticus from Vellar ...

    African Journals Online (AJOL)

    Vibrio parahaemolyticus is the predominant seafood pathogen associated with human gastroenteritis. Samples were collected from Vellar estuary, shrimp ponds and shrimp for characterization of V. parahaemolyticus. A total of 26 blue green centre (BG) Vibrio strains were isolated and characterized through biochemical ...

  5. Contaminant Case Report: Spectacled eider (Somateria fischeri) eggs and feathers from the Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We collected spectacled eider (Somateria fischeri) eggs and shed breast contour feathers from nests on the Yukon-Kuskokwim Delta, Alaska, in 1992 to evaluate...

  6. The Vibrio cholerae O139 O-antigen polysaccharide is essential for Ca2+-dependent biofilm development in sea water

    OpenAIRE

    Kierek, Katharine; Watnick, Paula I.

    2003-01-01

    Vibrio cholerae is both an inhabitant of estuarine environments and the etiologic agent of the diarrheal disease cholera. Previous work has demonstrated that V. cholerae forms both an exopolysaccharide-dependent biofilm and a Ca2+-dependent biofilm. In this work, we demonstrate a role for the O-antigen polysaccharide of V. cholerae in Ca2+-dependent biofilm development in model and true sea water. Interestingly, V. cholerae biofilms, as well as the biofilms of several other Vibrio species, di...

  7. Assessment of bacterial biodetoxification of herbicide atrazine using Aliivibrio fischeri cytotoxicity assay with prolonged contact time.

    Science.gov (United States)

    Háhn, Judit; Szoboszlay, Sándor; Tóth, Gergő; Kriszt, Balázs

    2017-07-01

    In our study, we determined and compared the atrazine-biodetoxification ability of 41 bacterial strains and 21 consortia created of those with over 50% degradation rate in pure cultures. Biodegradation capacity was measured with GC-MS. Detoxification was assessed based on the cytotoxic effect of end-products to Aliivibrio fischeri in chronic bioluminescence inhibition assay with 25 h contact time. Chronic A. fischeri assay adapted to a microplate, which is suitable for examine numerous residues simultaneously, also appeared to be significantly more sensitive to atrazine compared to the standard acute (30 min) test. Due to its sensitivity, the chronic assay could be a valuable tool to provide a more comprehensive view of the ecological risks of atrazine and other chemicals. Thirteen strains were able to degrade more than 50% of 50 ppm atrazine. Four of these belong to Rhodococcus aetherivorans, R. qingshengii, Serratia fonticola and Olivibacter oleidegradans which species' atrazine degrading ability has never been reported before. Four consortia degrading ability was more effective than that of the creating individual strains; moreover, their residues did not show cytotoxic effects to A. fischeri. However, in several cases, the degradation products of sole strains and consortia resulted in significant bioluminescence inhibition. Thus high biodegradation (>90%) does not certainly mean the reduction or cessation of toxicity highlighting the importance of the evaluation of biological effects of degradation residues to improve the efficiency and abate the ecological risks of bioremediation techniques.

  8. Complete genome sequence of a giant Vibrio phage ValKK3 infecting Vibrio alginolyticus

    Directory of Open Access Journals (Sweden)

    Tamrin M. Lal

    2016-06-01

    Full Text Available This paper describes the complete sequence of a giant lytic marine myophage, Vibrio phage ValKK3 that is specific to Vibrio alginolyticus ATCC® 17749™. Vibrio phage ValKK3 was subjected to whole genome sequencing on MiSeq sequencing platform and annotated using Blast2Go. The complete sequence of ValKK3 genome was deposited in DBBJ/EMBL/GenBank under accession number KP671755.

  9. Complete genome sequence of a giant Vibrio phage ValKK3 infecting Vibrio alginolyticus.

    Science.gov (United States)

    Lal, Tamrin M; Sano, Motohiko; Hatai, Kishio; Ransangan, Julian

    2016-06-01

    This paper describes the complete sequence of a giant lytic marine myophage, Vibrio phage ValKK3 that is specific to Vibrio alginolyticus ATCC(®) 17749™. Vibrio phage ValKK3 was subjected to whole genome sequencing on MiSeq sequencing platform and annotated using Blast2Go. The complete sequence of ValKK3 genome was deposited in DBBJ/EMBL/GenBank under accession number KP671755.

  10. 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.

  11. The LuxR regulator protein controls synthesis of polyhydroxybutyrate in Vibrio harveyi.

    Science.gov (United States)

    Miyamoto, C M; Sun, W; Meighen, E A

    1998-05-19

    The LuxR regulatory protein of Vibrio harveyi has been shown to control synthesis of polyhydroxybutyrate (PHB) as well as luminescence so as to occur at high cell density, suggesting that it is a general regulatory protein. Mutants defective in the production of LuxR (D1, D34, and MR1130) were found to be missing PHB, whose synthesis could be restored by complementation with luxR. Triparental mating with a V. harveyi genomic library revealed the presence of three genomic clones (G1, G2 and G3) that could also restore PHB synthesis and luminescence to cells which express low levels of luxR (D1 and D34) but not to luxR- cells (MR1130) suggesting that luxR expression was being stimulated. Analyses of luxR mRNA levels by mRNA dot blot hybridization and by primer extension confirmed that luxR mRNA levels were increased 4 to 7-fold in the D1 and D34 cells by the G1, G2 and G3 fragments and show that expression of a single genomic copy of luxR is sufficient to restore synthesis of PHB. The results demonstrate that V. harveyi LuxR controls the induction of a process not intimately involved in the bioluminescence system and clearly distinguishes its role in V. harveyi from that of LuxR from Vibrio (Photobacterium) fischeri, which has only been associated with regulation of light emission.

  12. Bacterial bioluminescence regulates expression of a host cryptochrome gene in the squid-Vibrio symbiosis.

    Science.gov (United States)

    Heath-Heckman, Elizabeth A C; Peyer, Suzanne M; Whistler, Cheryl A; Apicella, Michael A; Goldman, William E; McFall-Ngai, Margaret J

    2013-04-02

    The symbiosis between the squid Euprymna scolopes and its luminous symbiont, Vibrio fischeri, is characterized by daily transcriptional rhythms in both partners and daily fluctuations in symbiont luminescence. In this study, we sought to determine whether symbionts affect host transcriptional rhythms. We identified two transcripts in host tissues (E. scolopes cry1 [escry1] and escry2) that encode cryptochromes, proteins that influence circadian rhythms in other systems. Both genes cycled daily in the head of the squid, with a pattern similar to that of other animals, in which expression of certain cry genes is entrained by environmental light. In contrast, escry1 expression cycled in the symbiont-colonized light organ with 8-fold upregulation coincident with the rhythms of bacterial luminescence, which are offset from the day/night light regime. Colonization of the juvenile light organ by symbionts was required for induction of escry1 cycling. Further, analysis with a mutant strain defective in light production showed that symbiont luminescence is essential for cycling of escry1; this defect could be complemented by presentation of exogenous blue light. However, blue-light exposure alone did not induce cycling in nonsymbiotic animals, but addition of molecules of the symbiont cell envelope to light-exposed animals did recover significant cycling activity, showing that light acts in synergy with other symbiont features to induce cycling. While symbiont luminescence may be a character specific to rhythms of the squid-vibrio association, resident microbial partners could similarly influence well-documented daily rhythms in other systems, such as the mammalian gut.

  13. Bacteriophage interactions with marine pathogenic Vibrios

    DEFF Research Database (Denmark)

    Kalatzis, Panagiotis

    Incidents of Vibrio-associated diseases in marine aquaculture are increasingly reported on a global scale, incited also by the world’s rising temperature. Administration of antibiotics has been the most commonly applied remedy used for facing vibriosis outbreaks, giving rise to concerns about...... 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...... to studying the interactions between marine pathogenic Vibrio and their corresponding bacteriophages, while discussing the potential and limitations of phage therapy application in the biological control of vibriosis....

  14. Occurrences of pathogenic Vibrio parahaemolyticus from Vellar ...

    African Journals Online (AJOL)

    user

    2013-04-03

    2001). Vibrio vulnificus as a health hazard for shrimp consumers. Revista do Instituto de Medicina Tropical de Sao Paulo. 43: 263- 266. Sambrook J, Fritsch EF, Maniatis T (1989). Molecular Cloning: A. Laboratory Manual, 2nd ed.

  15. Leisingera sp. JC1, a Bacterial Isolate from Hawaiian Bobtail Squid Eggs, Produces Indigoidine and Differentially Inhibits Vibrios

    Directory of Open Access Journals (Sweden)

    Samantha M. Gromek

    2016-09-01

    Full Text Available Female members of many cephalopod species house a bacterial consortium that is part of their reproductive system, the accessory nidamental gland (ANG. These bacteria are deposited into eggs that are then laid in the environment where they must develop unprotected from predation, pathogens and fouling. In this study, we characterized the genome and secondary metabolite production of Leisingera sp. JC1, a member of the roseobacter clade (Rhodobacteraceae of Alphaproteobacteria isolated from the jelly coat of eggs from the Hawaiian bobtail squid, Euprymna scolopes. Whole genome sequencing and MLSA analysis revealed that Leisingera sp. JC1 falls within a group of roseobacters associated with squid ANGs. Genome and biochemical analyses revealed the potential for and production of a number of secondary metabolites, including siderophores and acyl-homoserine lactones involved with quorum sensing. The complete biosynthetic gene cluster for the pigment indigoidine was detected in the genome and mass spectrometry confirmed the production of this compound. Furthermore, we investigated the production of indigoidine under co-culture conditions with Vibrio fischeri, the light organ symbiont of E. scolopes, and with other vibrios. Finally, both Leisingera sp. JC1 and secondary metabolite extracts of this strain had differential antimicrobial activity against a number of marine vibrios, suggesting that Leisingera sp. JC1 may play a role in host defense against other marine bacteria either in the eggs and/or ANG. These data also suggest that indigoidine may be partially, but not wholly, responsible for the antimicrobial activity of this squid-associated bacterium. □

  16. Vibrio diseases of marine fish populations

    Science.gov (United States)

    Colwell, R. R.; Grimes, D. J.

    1984-03-01

    Several Vibrio spp. cause disease in marine fish populations, both wild and cultured. The most common disease, vibriosis, is caused by V. anguillarum. However, increase in the intensity of mariculture, combined with continuing improvements in bacterial systematics, expands the list of Vibrio spp. that cause fish disease. The bacterial pathogens, species of fish affected, virulence mechanisms, and disease treatment and prevention are included as topics of emphasis in this review.

  17. Vibrio chromosomes share common history

    Directory of Open Access Journals (Sweden)

    Gevers Dirk

    2010-05-01

    Full Text Available Abstract Background While most gamma proteobacteria have a single circular chromosome, Vibrionales have two circular chromosomes. Horizontal gene transfer is common among Vibrios, and in light of this genetic mobility, it is an open question to what extent the two chromosomes themselves share a common history since their formation. Results Single copy genes from each chromosome (142 genes from chromosome I and 42 genes from chromosome II were identified from 19 sequenced Vibrionales genomes and their phylogenetic comparison suggests consistent phylogenies for each chromosome. Additionally, study of the gene organization and phylogeny of the respective origins of replication confirmed the shared history. Conclusions Thus, while elements within the chromosomes may have experienced significant genetic mobility, the backbones share a common history. This allows conclusions based on multilocus sequence analysis (MLSA for one chromosome to be applied equally to both chromosomes.

  18. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Skovgaard, Ole; Ducos-Galand, Magaly

    2012-01-01

    importance in public health, Vibrio cholerae, the causative agent of cholera, has become a preferred model to study bacteria with multipartite genomes. However, most in vivo studies in V. cholerae have been hampered by its genome architecture, as it is difficult to give phenotypes to a specific chromosome....... This difficulty was surmounted using a unique and powerful strategy based on massive rearrangement of prokaryotic genomes. We developed a site-specific recombination-based engineering tool, which allows targeted, oriented, and reciprocal DNA exchanges. Using this genetic tool, we obtained a panel of V. cholerae...... in V. cholerae and the general question concerning bacteria carrying circular chromosomes--by looking at the effect of chromosome size on topological issues. In this article, we show that Dam, RctB, and ParA2/ParB2 are strictly essential for chrII origin maintenance, and we formally demonstrate...

  19. Antibiotic Susceptibility Patterns of Vibrio cholerae isolates

    Directory of Open Access Journals (Sweden)

    S D Shrestha

    2010-09-01

    Full Text Available INTRODUCTION: Cholera is one of the most common diarrhoeal diseases in Nepal. Etiological agent of cholera is Vibrio cholerae which removes essential body fluids, salts and vital nutrients, which are necessary for life causing dehydration and malnutrition. Emerging antimicrobial resistant is common. The aim of the present study was to determine the antibiotic susceptibility pattern of cholera patients in Nepal. METHODS: All the laboratory works were conducted in the bacteriology section of National Public Health Laboratory, Teku from March to September 2005. During this period a total of 340 stool samples from diarrhoeal patients were collected and processed according to the standard laboratory methods. Each patient suffering from diarrhoea was directly interviewed for his or her clinical history during sample collection. RESULTS: A total of 340 stool samples were processed and studied from both sex including all ages of patients. Among the processed sample 53 Vibrio cholerae cases were found. All isolated Vibrio cholerae O1 were El Tor, Inaba. All isolated (100% Vibrio cholerae O1 were sensitive to Ampicillin, Ciprofloxacin, Erythromycin and Tetracycline whereas all were resistant to Nalidixic acid and Cotrimoxazole. Only 15.1% cases were sensitive to Furazolidone whereas 84.9% were resistant. CONCLUSION: All V. cholerae strains isolated in this study were found resistant to Multi Drug Resistant (resistant to at least two antibiotics of different group. Ampicillin, Ciprofloxacin, Erythromycin and Tetracycline were found still more potent antibiotics against Vibrio cholerae isolated during the study. Keywords: antibiotics, susceptibility, Vibrio cholera.

  20. Surface-attachment sequence in Vibrio Cholerae

    Science.gov (United States)

    Utada, Andrew; Gibiansky, Maxsim; Wong, Gerard

    2013-03-01

    Vibrio cholerae is a gram-negative bacterium that causes the human disease cholera. It is found natively in brackish costal waters in temperate climates, where it attaches to the surfaces of a variety of different aquatic life. V. cholerae has a single polar flagellum making it highly motile, as well as a number of different pili types, enabling it to attach to both biotic and abiotic surfaces. Using in-house built tracking software we track all surface-attaching bacteria from high-speed movies to examine the early-time attachment profile of v. cholerae onto a smooth glass surface. Similar to previous work, we observe right-handed circular swimming trajectories near surfaces; however, in addition we see a host of distinct motility mechanisms that enable rapid exploration of the surface before forming a more permanent attachment. Using isogenic mutants we show that the motility mechanisms observed are due to a complex combination of hydrodynamics and pili-surface interactions. Lauga, E., DiLuzio, W. R., Whitesides, G. M., Stone, H. A. Biophys. J. 90, 400 (2006).

  1. Identifying the cellular mechanisms of symbiont-induced epithelial morphogenesis in the squid-Vibrio association.

    Science.gov (United States)

    Koropatnick, Tanya; Goodson, Michael S; Heath-Heckman, Elizabeth A C; McFall-Ngai, Margaret

    2014-02-01

    The symbiotic association between the Hawaiian bobtail squid Euprymna scolopes and the luminous marine bacterium Vibrio fischeri provides a unique opportunity to study epithelial morphogenesis. Shortly after hatching, the squid host harvests bacteria from the seawater using currents created by two elaborate fields of ciliated epithelia on the surface of the juvenile light organ. After light organ colonization, the symbiont population signals the gradual loss of the ciliated epithelia through apoptosis of the cells, which culminates in the complete regression of these tissues. Whereas aspects of this process have been studied at the morphological, biochemical, and molecular levels, no in-depth analysis of the cellular events has been reported. Here we describe the cellular structure of the epithelial field and present evidence that the symbiosis-induced regression occurs in two steps. Using confocal microscopic analyses, we observed an initial epithelial remodeling, which serves to disable the function of the harvesting apparatus, followed by a protracted regression involving actin rearrangements and epithelial cell extrusion. We identified a metal-dependent gelatinolytic activity in the symbiont-induced morphogenic epithelial fields, suggesting the involvement of Zn-dependent matrix metalloproteinase(s) (MMP) in light organ morphogenesis. These data show that the bacterial symbionts not only induce apoptosis of the field, but also change the form, function, and biochemistry of the cells as part of the morphogenic program.

  2. Impact and influence of the natural Vibrio-squid symbiosis in understanding bacterial-animal interactions

    Directory of Open Access Journals (Sweden)

    Mark J Mandel

    2016-12-01

    Full Text Available Animals are colonized by bacteria, and in many cases partners have co-evolved to perform mutually beneficial functions. An exciting and ongoing legacy of the past decade has been an expansion of technology to enable study of natural associations in situ/in vivo. As a result, more symbioses are being examined, and additional details are being revealed for well-studied systems with a focus on the interactions between partners in the native context. With this framing, we review recent literature from the Vibrio fischeri-Euprymna scolopes symbiosis and focus on key studies that have had an impact on understanding bacteria-animal interactions broadly. This is not intended to be a comprehensive review of the system, but rather to focus on particular studies that have excelled at moving from pattern to process in facilitating an understanding of the molecular basis to intriguing observations in the field of host-microbe interactions. In this review we discuss the following topics: processes regulating strain and species specificity; bacterial signaling to host morphogenesis; multiple roles for nitric oxide; flagellar motility and chemotaxis; and efforts to understand unannotated and poorly annotated genes. Overall these studies demonstrate how functional approaches in vivo in a tractable system have provided valuable insight into general principles of microbe-host interactions.

  3. 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...

  4. 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.

  5. Vibrios associated with red tides caused by Mesodinium rubrum.

    OpenAIRE

    Romalde, J L; Barja, J L; Toranzo, A E

    1990-01-01

    Vibrios were isolated from red tides caused by Mesodinium rubrum and also throughout the year in the Ria de Pontevedra, Spain. The isolates were grouped into 14 phena by numerical toxonomy. Strains associated with red tides were restricted to four phena: phena I and II were Vibrio alginolyticus, and phena III and IV were Vibrio tubiashii and Vibrio anguillarum, respectively. V. anguillarum-like strains (phena V through XI) predominated throughout the year outside the red tide areas. Cytotoxic...

  6. 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.

  7. 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.

  8. 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.

  9. Stem Rot on Ligularia fischeri Caused by Sclerotium rolfsii in Korea

    Directory of Open Access Journals (Sweden)

    Youn-Gi Moon

    2015-03-01

    Full Text Available In June 2012 and 2013, a destructive stem rot symptoms of Ligularia fischeri occurred sporadically in Hoengseong- gun and Pyeongchang-gun Gangwon-do, Korea. The typical symptom included water-soaking on the main stem, rotting, wilting and blighting, which eventually leads to death of the plant. White mycelial mats were spread over lesions and brown sclerotia were formed on stems and near soil surface. The sclerotia were white to brown, spherical or irregular, 1-3 mm in size on potato dextrose agar (PDA, The optimum temperature range of hyphal growth was 25-30oC and the hyphal diameter was 4-10 mm. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. The resulting sequence of 695 bp was deposited in GenBank. A BLAST search revealed that sequences of the this isolates showed >99% identity with those of Sclerotium rolfsii. On the basis of the morphological characteristics and phylogenetic analyses of molecular markers ITS rDNA, the fungi were identified as S. rolfsii. A pathogenicity test was carried out to fulfill Koch’s postulates. To our knowledge, this is the first report of S. rolfsii on Ligularia fischeri in Korea

  10. A decrease in bulk water and mannitol and accumulation of trehalose and trehalose-based oligosaccharides define a two-stage maturation process towards extreme stress resistance in ascospores of Neosartorya fischeri (Aspergillus fischeri)

    NARCIS (Netherlands)

    Wyatt, Timon T; Golovina, Elena A; van Leeuwen, Richard; Hallsworth, John E; Wösten, Han A B; Dijksterhuis, Jan

    Fungal propagules survive stresses better than vegetative cells. Neosartorya fischeri, an Aspergillus teleomorph, forms ascospores that survive high temperatures or drying followed by heat. Not much is known about maturation and development of extreme stress resistance in fungal cells. This study

  11. 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...

  12. 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...

  13. Genome analysis of the coral bleaching pathogen Vibrio shiloi.

    Science.gov (United States)

    Reshef, Leah; Ron, Eliora; Rosenberg, Eugene

    2008-08-01

    The past few decades have seen a world-wide increase in coral diseases, yet little is known about coral pathogens. In this study, techniques commonly used in pathogenomic research were applied to the coral pathogen Vibrio shiloi in order to identify genetic elements involved in its virulence. Suppressive subtractive hybridization was used to compare the gene content of V. shiloi to that of a closely related but non-pathogenic bacterium, Vibrio mediterranei, resulting in identification of several putative virulence factors and of three novel genomic islands. The entire genome of V. shiloi was further screened for genes related to previously characterized steps in infection: adhesion, superoxide dismutase production and toxin production. Exposure of pure cultures of V. shiloi to crushed coral tissues strongly affected the expression of seven genes encoding pili, zona occludins toxin (Zot) and a superoxide dismutase. Analysis of eight V. shiloi strains isolated in the last decade shows a shift of the natural population from strains carrying all three genomic islands to strains carrying none of them. This shift occurred following appearance of resistance in the coral Oculina patagonica to infection by V. shiloi. The relevance of these findings to the bleaching disease caused by V. shiloi is discussed.

  14. Benthic ecology of Vibrio spp. and pathogenic Vibrio species in a coastal Mediterranean environment (La Spezia Gulf, Italy).

    Science.gov (United States)

    Vezzulli, Luigi; Pezzati, Elisabetta; Moreno, Mariapaola; Fabiano, Mauro; Pane, Luigi; Pruzzo, Carla

    2009-11-01

    We carried out a 16-month in situ study to investigate the ecology of Vibrio spp. and pathogenic Vibrio species in coastal sediments of the Mediterranean Sea, employing multiple-regression analysis to reveal the major environmental factors controlling their occurrence in the benthic environment. In addition, association between vibrios and sediment-inhabiting meiofauna, which is a major component of benthic ecosystems, was investigated. Culturable and total Vibrio spp. estimates by most-probable-number technique coupled with standard polymerase chain reaction (PCR) and real-time PCR methods, respectively, were at least one order of magnitude higher in sediment than in seawater. In addition, potential human pathogenic species Vibrio cholerae, Vibrio vulnificus and Vibrio parahaemolyticus occurred in the sediment with V. parahaemolyticus being the most frequently found. In the pelagic environment, 60% of total variance in culturable Vibrio data was explained by sea surface temperature (40%), salinity (13%) and organic matter concentration (7%). In the benthic environment, sea surface temperature was the only factor that significantly affected culturable Vibrio occurrence although it explained only 25% of total variance, suggesting that additional unexplored factors may play a role as well. No correlation was found between culturable Vibrio spp. concentrations and the abundance of harpacticoid copepods in the sediment whilst a negative correlation was found between Vibrio spp. and nematode abundance which accounted for almost 90% of the total meiofaunal density. Taxonomic analysis revealed that selective bacterial feeders accounted for nearly 50% of the total nematode community and included genera such as Terschellingia, Molgolaimus and Halalaimus, suggesting that top-down control by nematode grazing may be an important factor affecting Vibrio occurrence in these sediments. It is concluded that the benthic marine environment may function as a reservoir of Vibrio spp

  15. Antimicrobial susceptibilty of potentially pathogenic halophilic Vibrio ...

    African Journals Online (AJOL)

    Surveillance of antimicrobial resistance is indispensable for empirical treatment of infections and in preventing the spread of antimicrobial resistant microorganisms. This study is aimed at determining the antibiotic susceptibility of potentially pathogenic halophylic Vibrio species isolated in Lagos, Nigeria. Susceptibility ...

  16. 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 ...

  17. 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

  18. Identification of a novel UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from Vibrio fischeri that confers high fosfomycin resistance in Escherichia coli

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, S.; Parvathi, A; Hernandez, R.L.; Cadle, K.M.; Varela, M.F.

    MurA [UDP-N-acetylglucosamine (UDP-NAG) enolpyruvyl transferase] is a key enzyme involved in bacterial cell wall peptidoglycan synthesis and a target for the antimicrobial agent fosfomycin, a structural analog of the MurA substrate phosphoenol...

  19. Plankton composition and environmental factors contribute to Vibrio seasonality.

    Science.gov (United States)

    Turner, Jeffrey W; Good, Brooks; Cole, Dana; Lipp, Erin K

    2009-09-01

    Plankton represent a nutrient-rich reservoir capable of enriching Vibrio species, which can include human pathogens, at higher densities than the surrounding water column. To better understand the relationship between vibrios and plankton, the partitioning of culturable vibrios, on TCBS, between free living and plankton associated (63-200- and >200-microm-size fractions) was monitored over a 1-year period in coastal waters of Georgia, USA. Seasonal changes in the total Vibrio concentration were then compared with changes in environmental parameters as well as changes in the relative composition of the plankton community. Using univariate analyses, Vibrio concentrations were strongly associated with temperature, especially when those vibrios were plankton associated (R(2)=0.69 and 0.88 for the water and both plankton fractions; respectively) (Pplankton fractions were also correlated to shifts in the relative abundance of specific plankton taxa. In the 63-200-micro fraction, Vibrio concentrations were inversely associated with copepods, cyanobacteria and diatoms. In the >200-micro fraction, Vibrio concentrations were positively associated with copepods and negatively associated with decapod larvae. Our results confirm the role of temperature in Vibrio seasonality and highlight an important and independent role for plankton composition in explaining seasonal changes in Vibrio concentration.

  20. Emergence of Asiatic Vibrio diseases in South America in phase with El Niño.

    Science.gov (United States)

    Martinez-Urtaza, Jaime; Huapaya, Blanca; Gavilan, Ronnie G; Blanco-Abad, Veronica; Ansede-Bermejo, Juan; Cadarso-Suarez, Carmen; Figueiras, Adolfo; Trinanes, Joaquin

    2008-11-01

    The seventh pandemic of Vibrio cholerae unexpectedly reached the coast of Peru in 1991, causing an explosive emergence of infections throughout the American continents. The origin and routes of dissemination are as yet unknown. A new Vibrio epidemic arose in 1997 in South America (northern Chile) when the pandemic clone of Vibrio parahaemolyticus was for the fist time detected outside of Asia. These 2 cases were concurrent with 2 episodes of El Niño. We carried out a survey of records of V. parahaemolyticus infection and of strains existing in the Instituto Nacional de Salud of Peru between 1994 and 2005. Association between the El Niño event and the V. parahaemolyticus disease was analyzed through generalized additive models applied to time-series data with negative binomial response, selecting some oceanographic factors distinctive of the movement of the El Niño waters. Epidemiologic data and laboratory investigations of the strains showed that V. parahaemolyticus infections caused by the pandemic clone emerged in the coasts of Peru linked to the 1997 El Niño episode. The epidemic dissemination of this clone matched the expansion and dynamics of the poleward propagation and the receding of the El Niño waters. This pattern was similar to previously reported onset of cholera epidemic in 1991. These findings identify the El Niño episodes as a reliable vehicle for the introduction and propagation of Vibrio pathogens in South America. The movement of oceanic waters seems to be one of the driving forces of the spread of Vibrio diseases.

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

    Science.gov (United States)

    Esteves, Kévin; Mosser, Thomas; Aujoulat, Fabien; Hervio-Heath, Dominique; Monfort, Patrick; Jumas-Bilak, Estelle

    2015-01-01

    Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species found in Mediterranean coastal systems can induce infections in 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 condition for V. parahaemolyticus and V. cholerae whereas the frequency of recombination events in V. cholerae was lower in low salinity condition. 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. PMID:26236294

  2. Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

    Science.gov (United States)

    Lutz, Carla; Erken, Martina; Noorian, Parisa; Sun, Shuyang; McDougald, Diane

    2013-01-01

    It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium can be detected in areas where it has not previously been isolated, indicating a much broader, global distribution of this bacterium outside of endemic regions. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of this bacterium in the environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature, and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists. PMID:24379807

  3. Extended serotyping scheme for Vibrio anguillarum with the definition and characterization of seven provisional O-serogroups

    DEFF Research Database (Denmark)

    Pedersen, Karl; Grisez, L.; van Houdt, R.

    1999-01-01

    The present paper summarizes the serotyping scheme of the fish pathogenic bacterium Vibrio anguillarum and defines seven additional O-serogroups. Strains, collected in our laboratories that were nontypable with antisera against the previously defined 16 O-serotypes, were used for generating new...

  4. Comparison of Chemical Sensitivity of Fresh and Long-Stored Heat Resistant Neosartorya fischeri Environmental Isolates Using BIOLOG Phenotype MicroArray System.

    Directory of Open Access Journals (Sweden)

    Jacek Panek

    Full Text Available Spoilage of heat processed food and beverage by heat resistant fungi (HRF is a major problem for food industry in many countries. Neosartorya fischeri is the leading source of spoilage in thermally processed products. Its resistance to heat processing and toxigenicity makes studies about Neosartorya fischeri metabolism and chemical sensitivity essential. In this study chemical sensitivity of two environmental Neosartorya fischeri isolates were compared. One was isolated from canned apples in 1923 (DSM3700, the other from thermal processed strawberry product in 2012 (KC179765, used as long-stored and fresh isolate, respectively. The study was conducted using Biolog Phenotype MicroArray platforms of chemical sensitivity panel and traditional hole-plate method. The study allowed for obtaining data about Neosartorya fischeri growth inhibitors. The fresh isolate appeared to be much more resistant to chemical agents than the long-stored isolate. Based on phenotype microarray assay nitrogen compounds, toxic cations and membrane function compounds were the most effective in growth inhibition of N. fischeri isolates. According to the study zaragozic acid A, thallium(I acetate and sodium selenate were potent and promising N. fischeri oriented fungicides which was confirmed by both chemical sensitivity microplates panel and traditional hole-plate methods.

  5. First study of Vibrios in larval cultures of pullet carpet shell clam (Venerupis corrugata in hatchery

    Directory of Open Access Journals (Sweden)

    Javier Dubert Pérez

    2014-07-01

    Full Text Available Protocol for hatchery culture of the pullet carpet shell clam Venerupis corrugata spat is currently under development, as the only reliable means of providing spat to replenish natural beds or to support aquaculture activities. Among other variables, the microbiota has been demonstrated to be critical for successful bivalve culture. Shellfish hatcheries are hindered by fatal outbreaks of disease, regardless the bivalve species. These mass mortalities are mainly caused by opportunistic bacteria belonging to genus Vibrio and constitute one bottleneck for this economic activity. Different species, as V. tubiashii, V. pectenicida, V. splendidus, V. neptunius, V. ostreicida and V. bivalvicida, have been identified as responsible of mortalities in hatchery-reared larvae, affecting a wide range of bivalves. This is the first report of the microbiota associated with larval cultures of the pullet carpet shell clam. We present the results of the microbiological analyses of two larval cultures of pullet carpet shell reared in the Centro de Investigacións Mariñas (CIMA, Xunta de Galicia de Ribadeo (Galicia, NW Spain following the procedures developed in the institution. Each batch, A and B, was obtained from broodstocks collected in natural environment but in different geographical locations, the stock A (SW Galicia and the stock B (NW Galicia. Previous records of mortalities led us to divide each batch in two. One sub-batch (A1 and B1 was cultured following the routine procedures. Antibiotic was experimentally added to the other sub-batch (A2 and B2 with the aim of evaluating the effects on the culturable bacterial population (total marine bacteria and presumptive vibrios and on larval survival. Chloramphenicol, formerly the most commonly used antibiotic in bivalve hatcheries, was supplied with each change of seawater during larval development. Microbiological samples of broodstock, larvae and seawater in culture tanks were taken and processed

  6. Vibrios associated with red tides caused by Mesodinium rubrum.

    Science.gov (United States)

    Romalde, J L; Barja, J L; Toranzo, A E

    1990-11-01

    Vibrios were isolated from red tides caused by Mesodinium rubrum and also throughout the year in the Ria de Pontevedra, Spain. The isolates were grouped into 14 phena by numerical toxonomy. Strains associated with red tides were restricted to four phena: phena I and II were Vibrio alginolyticus, and phena III and IV were Vibrio tubiashii and Vibrio anguillarum, respectively. V. anguillarum-like strains (phena V through XI) predominated throughout the year outside the red tide areas. Cytotoxicity assays conducted in different poikilothermic and homoiothermic cell lines showed that cytotoxin production was not necessarily associated with the species selected during the red tides.

  7. 21 CFR 866.3930 - Vibrio cholerae serological reagents.

    Science.gov (United States)

    2010-04-01

    ... cholera caused by the bacterium Vibrio cholerae and provides epidemiological information on cholera. Cholera is an acute infectious disease characterized by severe diarrhea with extreme fluid and electrolyte...

  8. Updating the Vibrio Clades Defined by Multilocus Sequence Phylogeny: Proposal of Eight New Clades, and the Description of Vibrio tritonius sp. nov.

    Directory of Open Access Journals (Sweden)

    Tomoo eSawabe

    2013-12-01

    Full Text Available To date 142 species have been described in the Vibrionaceae family of bacteria, classified into seven genera; Aliivibrio, Echinomonas, Enterovibrio, Grimontia, Photobacterium, Salinivibrio and Vibrio. As vibrios are widespread in marine environments and show versatile metabolisms and ecologies, these bacteria are recognized as one of the most diverse and important marine heterotrophic bacterial groups for elucidating the correlation between genome evolution and ecological adaptation. However, on the basis of 16S rRNA gene phylogeny, we could not find any robust monophyletic lineages in any of the known genera. We needed further attempts to reconstruct their evolutionary history based on multilocus sequence analysis (MLSA and/or genome wide taxonomy of all the recognized species groups. In our previous report in 2007, we conducted the first broad multilocus sequence analysis (MLSA to infer the evolutionary history of vibrios using nine housekeeping genes (the 16S rRNA gene, gapA, gyrB, ftsZ, mreB, pyrH, recA, rpoA, and topA, and we proposed 14 distinct clades in 58 species of Vibrionaceae. Due to the difficulty of designing universal primers that can amplify the genes for MLSA in every Vibrionaceae species, some clades had yet to be defined. In this study, we present a better picture of an updated molecular phylogeny for 86 described vibrio species and 10 genome sequenced Vibrionaceae strains, using 8 housekeeping gene sequences. This new study places special emphasis on 1 eight newly identified clades (Damselae, Mediterranei, Pectenicida, Phosphoreum, Profundum, Porteresiae, Rosenbergii, and Rumoiensis; 2 clades amended since the 2007 proposal with recently described new species; 3 orphan clades of genomospecies F6 and F10; 4 phylogenetic positions defined in 3 genome-sequenced strains (N418, EX25, and EJY3; and 5 description of V. tritonius sp. nov., which is a member of the Porteresiae clade.

  9. Modeling the growth of Byssochlamys fulva and Neosartorya fischeri on solidified apple juice by measuring colony diameter and ergosterol content.

    Science.gov (United States)

    Tremarin, Andréia; Longhi, Daniel Angelo; Salomão, Beatriz de Cassia Martins; Aragão, Gláucia Maria Falcão

    2015-01-16

    Byssochlamys fulva and Neosartorya fischeri are heat-resistant fungi which are a concern to food industries (e.g. apple juice industry) since their growth represents significant economic liabilities. Although the most common method used to assess fungal growth in solid substrates is by measuring the colony's diameter, it is difficult to apply this method to food substrates. Alternatively, ergosterol contents have been used to quantify fungal contamination in some types of food. The current study aimed at modeling the growth of the heat-resistant fungi B. fulva and N. fischeri by measuring the colony diameter and ergosterol content, fitting the Baranyi and Roberts model to the results, and finally establishing a correlation between the parameters of the two analytical methods. Whereas the colony diameter was measured daily, the quantification of ergosterol was performed when the colonies reached diameters of 30, 60, 90, 120 and 150 mm. Results showed that B. fulva and N. fischeri were able to grow successfully on solidified apple juice at 10, 15, 20, 25 and 30 °C, and the Baranyi and Roberts model showed good ability to describe growth data. The correlation curves between the parameters of colony diameter and ergosterol content were obtained with satisfactory statistical indexes. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Diversity and ecological structure of vibrios in benthic and pelagic habitats along a latitudinal gradient in the Southwest Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Luciane A. Chimetto Tonon

    2015-02-01

    Full Text Available We analyzed the diversity and population structure of the 775 Vibrio isolates from different locations of the southwestern Atlantic Ocean (SAO, including St. Peter and St. Paul Archipelago (SPSPA, Abrolhos Bank (AB and the St. Sebastian region (SS, between 2005 and 2010. In this study, 195 novel isolates, obtained from seawater and major benthic organisms (rhodoliths and corals, were compared with a collection of 580 isolates previously characterized (available at www.taxvibrio.lncc.br. The isolates were distributed in 8 major habitat spectra according to AdaptML analysis on the basis of pyrH phylogenetic reconstruction and ecological information, such as isolation source (i.e., corals: Madracis decactis, Mussismilia braziliensis, M. hispida, Phyllogorgia dilatata, Scolymia wellsi; zoanthids: Palythoa caribaeorum, P. variabilis and Zoanthus solanderi; fireworm: Hermodice carunculata; rhodolith; water and sediment and sampling site regions (SPSPA, AB and SS. Ecologically distinct groups were discerned through AdaptML, which finds phylogenetic groups that are significantly different in their spectra of habitat preferences. Some habitat spectra suggested ecological specialization, with habitat spectra 2, 3, and 4 corresponding to specialization on SPSPA, AB, and SS, respectively. This match between habitat and location may reflect a minor exchange of Vibrio populations between geographically isolated benthic systems. Moreover, we found several widespread Vibrio species predominantly from water column, and different populations of a single Vibrio species from H. carunculata in ecologically distinct groups (H-1 and H-8 respectively. On the other hand, AdaptML detected phylogenetic groups that are found in both the benthos and in open water. The ecological grouping observed suggests dispersal and connectivity between the benthic and pelagic systems in AB. This study is a first attempt to characterize the biogeographic distribution of vibrios in both

  11. Diversity and ecological structure of vibrios in benthic and pelagic habitats along a latitudinal gradient in the Southwest Atlantic Ocean

    Science.gov (United States)

    Silva, Bruno Sergio de O.; Moreira, Ana Paula B.; Valle, Cecilia; Alves, Nelson; Cavalcanti, Giselle; Garcia, Gizele; Lopes, Rubens M.; Francini-Filho, Ronaldo B.; de Moura, Rodrigo L.; Thompson, Cristiane C.

    2015-01-01

    We analyzed the diversity and population structure of the 775 Vibrio isolates from different locations of the southwestern Atlantic Ocean (SAO), including St. Peter and St. Paul Archipelago (SPSPA), Abrolhos Bank (AB) and the St. Sebastian region (SS), between 2005 and 2010. In this study, 195 novel isolates, obtained from seawater and major benthic organisms (rhodoliths and corals), were compared with a collection of 580 isolates previously characterized (available at www.taxvibrio.lncc.br). The isolates were distributed in 8 major habitat spectra according to AdaptML analysis on the basis of pyrH phylogenetic reconstruction and ecological information, such as isolation source (i.e., corals: Madracis decactis, Mussismilia braziliensis, M. hispida, Phyllogorgia dilatata, Scolymia wellsi; zoanthids: Palythoa caribaeorum, P. variabilis and Zoanthus solanderi; fireworm: Hermodice carunculata; rhodolith; water and sediment) and sampling site regions (SPSPA, AB and SS). Ecologically distinct groups were discerned through AdaptML, which finds phylogenetic groups that are significantly different in their spectra of habitat preferences. Some habitat spectra suggested ecological specialization, with habitat spectra 2, 3, and 4 corresponding to specialization on SPSPA, AB, and SS, respectively. This match between habitat and location may reflect a minor exchange of Vibrio populations between geographically isolated benthic systems. Moreover, we found several widespread Vibrio species predominantly from water column, and different populations of a single Vibrio species from H. carunculata in ecologically distinct groups (H-1 and H-8 respectively). On the other hand, AdaptML detected phylogenetic groups that are found in both the benthos and in open water. The ecological grouping observed suggests dispersal and connectivity between the benthic and pelagic systems in AB. This study is a first attempt to characterize the biogeographic distribution of vibrios in both seawater and

  12. 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 ...

  13. Environmental occurrence and clinical impact of Vibrio vulnificus and Vibrio parahaemolyticus: a European perspective.

    Science.gov (United States)

    Baker-Austin, Craig; Stockley, Louise; Rangdale, Rachel; Martinez-Urtaza, Jaime

    2010-02-01

    Vibrio vulnificus and Vibrio parahaemolyticus are ubiquitous Gram-negative bacterial pathogens found naturally in marine and estuarine waters, and are a leading cause of seafood-associated bacterial illness. These pathogens are commonly reported in the USA and in many Asian countries, including China, Japan and Taiwan; however, there is growing concern that V. vulnificus and V. parahaemolyticus may represent an important and increasing clinical problem in Europe. Several factors underlie the need for a greater understanding of these non-cholera vibrios within a European context. First, there is a growing body of evidence to suggest that V. vulnificus and V. parahaemolyticus infections are increasing, and tend to follow regional climatic trends, with outbreaks typically following episodes of unusually warm weather. Such findings are especially alarming given current predictions regarding warming of marine waters as a result of global climatic change. Second, a myriad of epidemiological factors may greatly increase the incidence as well as clinical burden of these pathogens - including increasing global consumption and trade of seafood produce coupled to an increase in the number of susceptible individuals consuming seafood produce. Finally, there is currently a lack of detailed surveillance information regarding non-cholerae Vibrio infections in Europe, as these pathogens are not notifiable in many countries, which probably masks the true clinical burden of many human infections. This review will present a pertinent overview of both the environmental occurrence and clinical impact of V. vulnificus and V. parahaemolyticus in Europe. © 2010 Crown copyright.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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 (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, providing data regulatory authorities can use to evaluate Vibrio spp. control plans. Published by Elsevier B.V.

  16. Monitoring of Vibrio harveyi quorum sensing activity in real time during infection of brine shrimp larvae

    Science.gov (United States)

    Defoirdt, Tom; Sorgeloos, Patrick

    2012-01-01

    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. PMID:22673627

  17. The Role of Vibrios in Diseases of Corals.

    Science.gov (United States)

    Munn, Colin B

    2015-08-01

    The tissue, skeleton, and secreted mucus of corals supports a highly dynamic and diverse community of microbes, which play a major role in the health status of corals such as the provision of essential nutrients or the metabolism of waste products. However, members of the Vibrio genus are prominent as causative agents of disease in corals. The aim of this chapter is to review our understanding of the spectrum of disease effects displayed by coral-associated vibrios, with a particular emphasis on the few species where detailed studies of pathogenicity have been conducted. The role of Vibrio shilonii in seasonal bleaching of Oculina patagonica and the development of the coral probiotic hypothesis is reviewed, pointing to unanswered questions about this phenomenon. Detailed consideration is given to studies of V. coralliilyticus and related pathogens and changes in the dominance of vibrios associated with coral bleaching. Other Vibrio-associated disease syndromes discussed include yellow band/blotch disease and tissue necrosis in temperate gorgonian corals. The review includes analysis of the role of enzymes, resistance to oxidative stress, and quorum sensing in virulence of coral-associated vibrios. The review concludes that we should probably regard most-possibly all-vibrios as "opportunistic" pathogens which, under certain environmental conditions, are capable of overwhelming the defense mechanisms of appropriate hosts, leading to rapid growth and tissue destruction.

  18. Catechol Siderophore Transport by Vibrio cholerae.

    Science.gov (United States)

    Wyckoff, Elizabeth E; Allred, Benjamin E; Raymond, Kenneth N; Payne, Shelley M

    2015-09-01

    Siderophores, small iron-binding molecules secreted by many microbial species, capture environmental iron for transport back into the cell. Vibrio cholerae synthesizes and uses the catechol siderophore vibriobactin and also uses siderophores secreted by other species, including enterobactin produced by Escherichia coli. E. coli secretes both canonical cyclic enterobactin and linear enterobactin derivatives likely derived from its cleavage by the enterobactin esterase Fes. We show here that V. cholerae does not use cyclic enterobactin but instead uses its linear derivatives. V. cholerae lacked both a receptor for efficient transport of cyclic enterobactin and enterobactin esterase to promote removal of iron from the ferrisiderophore complex. To further characterize the transport of catechol siderophores, we show that the linear enterobactin derivatives were transported into V. cholerae by either of the catechol siderophore receptors IrgA and VctA, which also transported the synthetic siderophore MECAM [1,3,5-N,N',N″-tris-(2,3-dihydroxybenzoyl)-triaminomethylbenzene]. Vibriobactin is transported via the additional catechol siderophore receptor ViuA, while the Vibrio fluvialis siderophore fluvibactin was transported by all three catechol receptors. ViuB, a putative V. cholerae siderophore-interacting protein (SIP), functionally substituted for the E. coli ferric reductase YqjH, which promotes the release of iron from the siderophore in the bacterial cytoplasm. In V. cholerae, ViuB was required for the use of vibriobactin but was not required for the use of MECAM, fluvibactin, ferrichrome, or the linear derivatives of enterobactin. This suggests the presence of another protein in V. cholerae capable of promoting the release of iron from these siderophores. Vibrio cholerae is a major human pathogen and also serves as a model for the Vibrionaceae, which include other serious human and fish pathogens. The ability of these species to persist and acquire essential

  19. Survival of Vibrio parahaemolyticus in cooked seafood at refrigeration temperatures.

    Science.gov (United States)

    Bradshaw, J G; Francis, D W; Twedt, R M

    1974-04-01

    The growth and survival of two strains of Vibrio parahaemolyticus isolated during food-borne gastroenteritis outbreaks in Japan and surface inoculated on cooked shrimp, shrimp with sauce, or cooked crab were tested at various refrigeration temperatures during a 48-h holding period. On cooked shrimp and crab, the vibrios grew well at 18.3 C, but their numbers declined gradually at 10 C and below. At 12.8 C, vibrios remained static for the most part. Thus, it appeared that 12.8 C was the borderline temperature for growth of the organism on cooked seafood. When cocktail sauce was added to surface-inoculated shrimp at a ratio of 2:1, the vibrio die-off rate was accelerated. In the shrimp and sauce few cells remained after 48 h, but in the sauce alone die-off was complete at 6 h.

  20. Opkomst van Vibrio infecties in brakwaterkweekvis : uit de ziekenboeg

    NARCIS (Netherlands)

    Haenen, O.L.M.; Engelsma, M.Y.

    2010-01-01

    De laatste paar jaar zijn er diverse Vibrio-soorten als ziekteverwekkende bacterie aangetoond in brak- en zoutwaterkweekvis. We gaan in dit artikel in op vibriose bij tong, tarbot, barramundi een zeebaars.

  1. Antibiotic Susceptibility Patterns and Plasmid Profile of Vibrio ...

    African Journals Online (AJOL)

    32.14%) samples of Vibrio cholerae isolates recovered from water samples from Elele Community. All isolates showed a multiple resistance patterns to 7 antibiotics namely amoxicillin, cotrimoxazole, nitrofurantoin, gentamicin, tetracycline, ...

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

    African Journals Online (AJOL)

    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 ...

  3. Inactivation of Vibrio anguillarum by attached and planktonic Roseobacter cells

    DEFF Research Database (Denmark)

    D'Alvise, Paul; Melchiorsen, Jette; Porsby, Cisse Hedegaard

    2010-01-01

    The purpose of the present study was to investigate inhibition of Vibrio by Roseobacter in a combined liquid-surface system. Exposure of Vibrio anguillarum to surface-attached roseobacters (10e7 cfu/cm2) resulted in significant reduction or complete killing of the pathogen inoculated at 10e2 – 10...... cfu/ml. The effect was likely associated with production of tropodithietic acid (TDA), as a TDA-negative mutant did not affect survival or growth of V. anguillarum....

  4. Mortality event involving larvae of the carpet shell clam Ruditapes decussatus in a hatchery: isolation of the pathogen Vibrio tubiashii subsp. europaeus.

    Science.gov (United States)

    Dubert, J; Aranda-Burgos, J A; Ojea, J; Barja, J L; Prado, S

    2017-09-01

    Diseases caused by bacteria belonging to the genus Vibrio are a common, as yet unresolved, cause of mortality in shellfish hatcheries. In this study, we report the results of routine microbiological monitoring of larval cultures of the carpet shell clam Ruditapes decussatus in a hatchery in Galicia (NW Spain). Previous episodes of mortality with signs similar to those of vibriosis affecting other species in the installation indicated the possibility of bacterial infection and led to division of the culture at the early D-veliger larval stage. One batch was cultured under routine conditions, and the other was experimentally treated with antibiotic (chloramphenicol). Differences in larval survival were assessed, and culturable bacterial population in clams and sea water was evaluated, with particular attention given to vibrios. Severe mortalities were recorded from the first stages of culture onwards. The pathogen Vibrio tubiashii subsp. europaeus was detected in both batches, mainly associated with larvae. Moreover, initial detection of the pathogen in the eggs suggested the vertical transmission from broodstock as a possible source. Experimental use of antibiotic reduced the presence and diversity of vibrios in sea water, but proved inefficient in controlling vibrios associated with larvae from early stages and it did not stop mortalities. © 2017 John Wiley & Sons Ltd.

  5. Vibrio cholerae Biofilms and Cholera Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Anisia J Silva

    2016-02-01

    Full Text Available Vibrio cholerae can switch between motile and biofilm lifestyles. The last decades have been marked by a remarkable increase in our knowledge of the structure, regulation, and function of biofilms formed under laboratory conditions. Evidence has grown suggesting that V. cholerae can form biofilm-like aggregates during infection that could play a critical role in pathogenesis and disease transmission. However, the structure and regulation of biofilms formed during infection, as well as their role in intestinal colonization and virulence, remains poorly understood. Here, we review (i the evidence for biofilm formation during infection, (ii the coordinate regulation of biofilm and virulence gene expression, and (iii the host signals that favor V. cholerae transitions between alternative lifestyles during intestinal colonization, and (iv we discuss a model for the role of V. cholerae biofilms in pathogenicity.

  6. Viscosity dictates metabolic activity of Vibrio ruber

    Science.gov (United States)

    Borić, Maja; Danevčič, Tjaša; Stopar, David

    2012-01-01

    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 (GPD) 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. PMID:22826705

  7. VpsT is a transcriptional regulator required for expression of vps biosynthesis genes and the development of rugose colonial morphology in Vibrio cholerae O1 El Tor.

    Science.gov (United States)

    Casper-Lindley, Catharina; Yildiz, Fitnat H

    2004-03-01

    Vibrio cholerae switches between smooth and rugose colonial variants. The rugose variant produces more vibrio polysaccharides (VPS(El Tor)) and forms well-developed biofilms. Both phenotypes depend on expression of vps biosynthesis genes. We identified a positive transcriptional regulator of vps gene expression, VpsT, which is homologous to response regulators of two-component regulatory systems. Disruption of vpsT in the rugose variant yields smooth colonies, prevents formation of mature biofilms, and decreases vps gene expression. The interaction between VpsT and VpsR, a previously identified positive regulator of vps genes, was also investigated.

  8. 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 resistance profiles of Vibrio spp. found on them. We collected 22 microplastic 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.

  9. 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.

  10. Mutation of Bacterium Vibrio gazogenes for Selective Preparation of Colorants

    Science.gov (United States)

    Alihosseini, Farzaneh; Lango, Jozsef; Ju, Kou-San; Hammock, Bruce D.; Sun, Gang

    2010-01-01

    A novel marine bacterium strain effectively produced prodiginine type pigments. These colorants could dye wool, silk and synthetic fabrics such as polyester and polyacrylic and also show antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria on the dyed products. Methyl nitrosoguanidine was used as a mutation agent to increase the genetic diversity and the production yield of the bacteria of the family of Vibrio gazogenes. The analysis of the mutated samples showed that two new main colorants as well as three previously found ones were produced. Liquid chromatography electro spray ionization mass spectrometry (LC-ESI-MS) and nuclear magnetic resonance (NMR) spectroscopic techniques were used to elucidate the structures of the newly produced colorants. Mass measurements revealed that the colorants C1, C2, C3, C4 have molecular masses of 321, 323, 351, and 295 Da. One unstable colorant C5 with molecular mass of 309 Da was detected as well. The mutated bacteria strains increased the yield of pigment production by about 81% and produced prodigiosin in 97% purity. The antibiotic activities of pure colorants are discussed as well. Based on their bio-activity and excellent dyeing capabilities, these colorants could be employed in cosmetic and textile industries. PMID:19902486

  11. Mutation of bacterium Vibrio gazogenes for selective preparation of colorants.

    Science.gov (United States)

    Alihosseini, Farzaneh; Lango, Jozsef; Ju, Kou-San; Hammock, Bruce D; Sun, Gang

    2010-01-01

    A novel marine bacterium strain effectively produced prodiginine type pigments. These colorants could dye wool, silk and synthetic fabrics such as polyester and polyacrylic and also show antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria on the dyed products. Methyl nitrosoguanidine was used as a mutation agent to increase the genetic diversity and the production yield of the bacteria of the family of Vibrio gazogenes. The analysis of the mutated samples showed that two new main colorants as well as three previously found ones were produced. Liquid chromatography electro spray ionization mass spectrometry (LC-ESI-MS) and nuclear magnetic resonance (NMR) spectroscopic techniques were used to elucidate the structures of the newly produced colorants. Mass measurements revealed that the colorants C1, C2, C3, C4 have molecular masses of 321, 323, 351, and 295 Da. One unstable colorant C5 with molecular mass of 309 Da was detected as well. The mutated bacteria strains increased the yield of pigment production by about 81% and produced prodigiosin in 97% purity. The antibiotic activities of pure colorants are discussed as well. Based on their bio-activity and excellent dyeing capabilities, these colorants could be employed in cosmetic and textile industries.

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

    Science.gov (United States)

    Ellingsen, Anette B; Olsen, Jaran S; Granum, Per E; Rørvik, Liv M; González-Escalona, Narjol

    2013-01-01

    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.

  13. Purification of Protease from Vibrio cholerae O1 and its Partial Characterization

    OpenAIRE

    Ichinose, Yoshio; Ehara, Masahiko; Utsunomiya, Akiyoshi

    1992-01-01

    A protease produced by a clinical isolate of Vibrio cholerae O1 was purified to apparent homogeneity by ammonium sulfate fractionation, ultracentrifuge and succesive column chromatography on a Bio-gel A5m and a TSK gel G-3000SW HPLC column. The molecular weight of the purified protease was estimated to be 32,000 on the basis of its mobility on SDS-PAGE and was identical to HA/protease biochemically and physicochemically as previously reported (Booth et al., 1983; Honda et al., 1987). The hema...

  14. 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...... reports; however, it has not been previously noted in Denmark. The authors report a case of septic arthritis caused by V. vulnificus in an immunocompromised patient. The disease progressed to severe sepsis and subsequent death within 10 h of admission....

  15. New Sequence Types of Vibrio parahaemolyticus Isolated from a Malaysian Aquaculture Pond, as Revealed by Whole-Genome Sequencing.

    Science.gov (United States)

    Foo, Soon Man; Eng, Wilhelm Wei Han; Lee, Yin Peng; Gui, Kimberly; Gan, Han Ming

    2017-05-11

    The acquisition of Photorhabdus insect-related (Pir) toxin-like genes in Vibrio parahaemolyticus has been linked to hepatopancreatic necrosis disease in shrimp. We report the whole-genome sequences of genetically virulent and avirulent V. parahaemolyticus isolated from a Malaysian aquaculture pond and show that they represent previously unreported sequence types of V. parahaemolyticus. Copyright © 2017 Foo et al.

  16. The mosaic accessory gene structures of the SXT/R391-like integrative and conjugative elements derived from Vibrio spp. isolated from aquatic products and environment in the Yangtze River Estuary, China.

    Science.gov (United States)

    Song, Yuze; Yu, Pan; Li, Bailin; Pan, Yingjie; Zhang, Xiaojun; Cong, Jian; Zhao, Yinying; Wang, Hua; Chen, Lanming

    2013-09-30

    The emergence, resurgence and spread of human food-borne pathogenic Vibrios are one of the major contributors to disease burden and mortality particularly in developing countries with disputable sanitary conditions. Previous research on pathogenic Vibrio cholerae and Vibrio parahaemolitycus derived from clinical samples has proposed links between acquisition of virulence and multiple drug resistance traits and intercellular transmissibility of mobile genetic elements in the environment. To date, very few information is available on environmental Vibrio isolates. In this study, we characterized eleven Vibrio strains bearing the SXT/R391-like integrative and conjugative elements (ICEs) derived from aquatic products and environment in the Yangtze River Estuary, China. The eleven Vibrio strains were isolated in 2010 to 2011, and taxonomically identified, which included six Vibrio cholerae, three Vibrio parahaemolyticus, one Vibrio alginolyticus and one Vibrio natriegens. Most of the strains displayed strong resistance phenotypes to ampicillin, mercury and chromium. The majority of their ICEs, which belong to S and R exclusion system groups, contain ICEs-chromosome junction sequences and highly conserved core-genes required for ICE transfer. However, comparative sequence analysis uncovered interesting diversity in their mosaic accessory gene structures, which carry many novel genes that have not been described in any known ICEs to date. In addition, antibiotic resistance was transmitted by ICEVchChn6 and ICEVpaChn1 from V. cholerae, V. parahaemolyticus to E. coli MG1655 via conjugation, respectively. Our data also revealed that the ICEs characterized in this study are phylogenetically distant from most of the SXT/R391 ICEs reported previously, which may represent a novel cluster likely shaped by the ecological environment in the Yangtze River Estuary, China. This study constitutes the first investigation of ICEs-positive Vibrio spp. in the Yangze River Estuary, China

  17. The mosaic accessory gene structures of the SXT/R391-like integrative and conjugative elements derived from Vibrio spp. isolated from aquatic products and environment in the Yangtze River estuary, China

    Science.gov (United States)

    2013-01-01

    Background The emergence, resurgence and spread of human food-borne pathogenic Vibrios are one of the major contributors to disease burden and mortality particularly in developing countries with disputable sanitary conditions. Previous research on pathogenic Vibrio cholerae and Vibrio parahaemolitycus derived from clinical samples has proposed links between acquisition of virulence and multiple drug resistance traits and intercellular transmissibility of mobile genetic elements in the environment. To date, very few information is available on environmental Vibrio isolates. In this study, we characterized eleven Vibrio strains bearing the SXT/R391-like integrative and conjugative elements (ICEs) derived from aquatic products and environment in the Yangtze River Estuary, China. Results The eleven Vibrio strains were isolated in 2010 to 2011, and taxonomically identified, which included six Vibrio cholerae, three Vibrio parahaemolyticus, one Vibrio alginolyticus and one Vibrio natriegens. Most of the strains displayed strong resistance phenotypes to ampicillin, mercury and chromium. The majority of their ICEs, which belong to S and R exclusion system groups, contain ICEs-chromosome junction sequences and highly conserved core-genes required for ICE transfer. However, comparative sequence analysis uncovered interesting diversity in their mosaic accessory gene structures, which carry many novel genes that have not been described in any known ICEs to date. In addition, antibiotic resistance was transmitted by ICEVchChn6 and ICEVpaChn1 from V. cholerae, V. parahaemolyticus to E. coli MG1655 via conjugation, respectively. Our data also revealed that the ICEs characterized in this study are phylogenetically distant from most of the SXT/R391 ICEs reported previously, which may represent a novel cluster likely shaped by the ecological environment in the Yangtze River Estuary, China. Conclusions This study constitutes the first investigation of ICEs-positive Vibrio spp. in the

  18. General baseline toxicity QSAR for nonpolar, polar and ionisable chemicals and their mixtures in the bioluminescence inhibition assay with Aliivibrio fischeri.

    Science.gov (United States)

    Escher, Beate I; Baumer, Andreas; Bittermann, Kai; Henneberger, Luise; König, Maria; Kühnert, Christin; Klüver, Nils

    2017-03-22

    The Microtox assay, a bioluminescence inhibition assay with the marine bacterium Aliivibrio fischeri, is one of the most popular bioassays for assessing the cytotoxicity of organic chemicals, mixtures and environmental samples. Most environmental chemicals act as baseline toxicants in this short-term screening assay, which is typically run with only 30 min of exposure duration. Numerous Quantitative Structure-Activity Relationships (QSARs) exist for the Microtox assay for nonpolar and polar narcosis. However, typical water pollutants, which have highly diverse structures covering a wide range of hydrophobicity and speciation from neutral to anionic and cationic, are often outside the applicability domain of these QSARs. To include all types of environmentally relevant organic pollutants we developed a general baseline toxicity QSAR using liposome-water distribution ratios as descriptors. Previous limitations in availability of experimental liposome-water partition constants were overcome by reliable prediction models based on polyparameter linear free energy relationships for neutral chemicals and the COSMOmic model for charged chemicals. With this QSAR and targeted mixture experiments we could demonstrate that ionisable chemicals fall in the applicability domain. Most investigated water pollutants acted as baseline toxicants in this bioassay, with the few outliers identified as uncouplers or reactive toxicants. The main limitation of the Microtox assay is that chemicals with a high melting point and/or high hydrophobicity were outside of the applicability domain because of their low water solubility. We quantitatively derived a solubility cut-off but also demonstrated with mixture experiments that chemicals inactive on their own can contribute to mixture toxicity, which is highly relevant for complex environmental mixtures, where these chemicals may be present at concentrations below the solubility cut-off.

  19. 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

  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

    2017-01-01

    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.

  1. Anti-vibrio potentials of acetone and aqueous leaf extracts of ...

    African Journals Online (AJOL)

    Purpose: To evaluate the anti-vibrio potentials of acetone and aqueous leaf extracts of Ocimum gratissimum and determine its relevance in the treatment of vibrios infection. Methods: The agar-well diffusion method was used for screening the extracts for their anti-vibrio activity. Broth micro-dilution assay was used to ...

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Non-Cholera Vibrios: The Microbial Barometer of Climate Change.

    Science.gov (United States)

    Baker-Austin, Craig; Trinanes, Joaquin; Gonzalez-Escalona, Narjol; Martinez-Urtaza, Jaime

    2017-01-01

    There is a growing interest in the role of climate change in driving the spread of waterborne infectious diseases, such as those caused by bacterial pathogens. One particular group of pathogenic bacteria - vibrios - are a globally important cause of diseases in humans and aquatic animals. These Gram-negative bacteria, including the species Vibrio vulnificus, Vibrio parahaemolyticus and Vibrio cholerae, grow in warm, low-salinity waters, and their abundance in the natural environment mirrors ambient environmental temperatures. In a rapidly warming marine environment, there are greater numbers of human infections, and most notably outbreaks linked to extreme weather events such as heatwaves in temperate regions such as Northern Europe. Because the growth of pathogenic vibrios in the natural environment is largely dictated by temperature, we argue that this group of pathogens represents an important and tangible barometer of climate change in marine systems. We provide a number of specific examples of the impacts of climate change on this group of bacteria and their associated diseases, and discuss advanced strategies to improve our understanding of these emerging waterborne diseases through the integration of microbiological, genomic, epidemiological, climatic, and ocean sciences. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  4. Vibrio parahaemolyticus- An emerging foodborne pathogen

    Directory of Open Access Journals (Sweden)

    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. Household Transmission of Vibrio cholerae in Bangladesh.

    Science.gov (United States)

    Sugimoto, Jonathan D; Koepke, Amanda A; Kenah, Eben E; Halloran, M Elizabeth; Chowdhury, Fahima; Khan, Ashraful I; LaRocque, Regina C; Yang, Yang; Ryan, Edward T; Qadri, Firdausi; Calderwood, Stephen B; Harris, Jason B; Longini, Ira M

    2014-11-01

    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-valuelevels 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 the transmissibility of endemic cholera within prospectively-followed members of households. The role of direct transmission must be considered when planning cholera control activities.

  6. Role of Vibrio polysaccharide (vps) genes in VPS production, biofilm formation and Vibrio cholerae pathogenesis.

    Science.gov (United States)

    Fong, Jiunn C N; Syed, Khalid A; Klose, Karl E; Yildiz, Fitnat H

    2010-09-01

    Biofilm formation enhances the survival and persistence of the facultative human pathogen Vibrio cholerae in natural ecosystems and its transmission during seasonal cholera outbreaks. A major component of the V. cholerae biofilm matrix is the Vibrio polysaccharide (VPS), which is essential for development of three-dimensional biofilm structures. The vps genes are clustered in two regions, the vps-I cluster (vpsU, vpsA-K, VC0916-27) and the vps-II cluster (vpsL-Q, VC0934-39), separated by an intergenic region containing the rbm gene cluster that encodes biofilm matrix proteins. In-frame deletions of the vps clusters and genes encoding matrix proteins drastically altered biofilm formation phenotypes. To determine which genes within the vps gene clusters are required for biofilm formation and VPS synthesis, we generated in-frame deletion mutants for all the vps genes. Many of these mutants exhibited reduced capacity to produce VPS and biofilms. Infant mouse colonization assays revealed that mutants lacking either vps clusters or rbmA (encoding secreted matrix protein RbmA) exhibited a defect in intestinal colonization compared to the wild-type. Understanding the roles of the various vps gene products will aid in the biochemical characterization of the VPS biosynthetic pathway and elucidate how vps gene products contribute to VPS biosynthesis, biofilm formation and virulence in V. cholerae.

  7. Differential metabolic responses of clam Ruditapes philippinarum to Vibrio anguillarum and Vibrio splendidus challenges.

    Science.gov (United States)

    Liu, Xiaoli; Ji, Chenglong; Zhao, Jianmin; Wu, Huifeng

    2013-12-01

    Clam Ruditapes philippinarum is one of the important marine aquaculture species in North China. However, pathogens can often cause diseases and lead to massive mortalities and economic losses of clam. In this work, we compared the metabolic responses induced by Vibrio anguillarum and Vibrio splendidus challenges towards hepatopancreas of clam using NMR-based metabolomics. Metabolic responses suggested that both V. anguillarum and V. splendidus induced disturbances in energy metabolism and osmotic regulation, oxidative and immune stresses with different mechanisms, as indicated by correspondingly differential metabolic biomarkers (e.g., amino acids, ATP, glucose, glycogen, taurine, betaine, choline and hypotaurine) and altered mRNA expression levels of related genes including ATP synthase, ATPase, glutathione peroxidase, heat shock protein 90, defensin and lysozyme. However, V. anguillarum caused more severe oxidative and immune stresses in clam hepatopancreas than V. splendidus. Our results indicated that metabolomics could be used to elucidate the biological effects of pathogens to the marine clam R. philippinarum. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Feeding truncated heat shock protein 70s protect Artemia franciscana against virulent Vibrio campbellii challenge.

    Science.gov (United States)

    Baruah, Kartik; Norouzitallab, Parisa; Shihao, Li; Sorgeloos, Patrick; Bossier, Peter

    2013-01-01

    The 70 kDa heat shock proteins (Hsp70s) are highly conserved in evolution, leading to striking similarities in structure and composition between eukaryotic Hsp70s and their homologs in prokaryotes. The eukaryotic Hsp70 like the DnaK (Escherichia coli equivalent Hsp70) protein, consist of three functionally distinct domains: an N-terminal 44-kDa ATPase portion, an 18-kDa peptide-binding domain and a C-terminal 10-kDa fragment. Previously, the amino acid sequence of eukaryotic (the brine shrimp Artemia franciscana) Hsp70 and DnaK proteins were shown to share a high degree of homology, particularly in the peptide-binding domain (59.6%, the putative innate immunity-activating portion) compared to the N-terminal ATPase (48.8%) and the C-terminal lid domains (19.4%). Next to this remarkable conservation, these proteins have been shown to generate protective immunity in Artemia against pathogenic Vibrio campbellii. This study, aimed to unravel the Vibrio-protective domain of Hsp70s in vivo, demonstrated that gnotobiotically cultured Artemia fed with recombinant C-terminal fragment (containing the conserved peptide binding domain) of Artemia Hsp70 or DnaK protein were well protected against subsequent Vibrio challenge. In addition, the prophenoloxidase (proPO) system, at both mRNA and protein activity levels, was also markedly induced by these truncated proteins, suggesting epitope(s) responsible for priming the proPO system and presumably other immune-related genes, consequently boosting Artemia survival upon challenge with V. campbellii, might be located within this conserved region of the peptide binding domain. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Insights into bacteriophage application in controlling Vibrio species

    Directory of Open Access Journals (Sweden)

    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. [Genomic variability of vibrio cholerae El Tor biovariant strains].

    Science.gov (United States)

    Smirnova, N I; Kostromitina, E A; Osin, A V; Kutyrev, V V

    2005-01-01

    The authors performed comparative analysis of the genomes of 145 clinical and environmental isolates of Vibrio cholerae El Tor biovariants using single locus and multiplex PCR. The study found that clinical strains isolated from patients with cholera formed a genetically homogenous group, where bacterial chromosome contained all the tested virulence genes, situated on mobile genetic elements that had been acquired by the pathogen at various stages of its evolution. Strains isolated from water ecosystems during interepidemic period were heterogeneous and formed three groups: a small number of virulent strains; non-toxigenic vibrio strains that, in the process of reductional variation in their new econiche, had only managed to maintain individual virulence genes; non-pathogenic "water" vibrios, whose chromosome contained only the genes from its core part, mobile genetic elements being optionally represented only by the persistence island. Molecular typing established genetic relations among V. cholerae strains under study.

  11. 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

  12. 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

  13. 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

  14. Temporal and spatial variability in culturable pathogenic Vibrio spp. in Lake Pontchartrain, Louisiana, following hurricanes Katrina and Rita.

    Science.gov (United States)

    Nigro, Olivia D; Hou, Aixin; Vithanage, Gayatri; Fujioka, Roger S; Steward, Grieg F

    2011-08-01

    We investigated the abundance, distribution, and virulence gene content of Vibrio cholerae, V. parahaemolyticus, and V. vulnificus in the waters of southern Lake Pontchartrain in Louisiana on four occasions from October 2005 to September 2006, using selective cultivation and molecular assays. The three targeted pathogenic vibrios were generally below the detection level in January 2006, when the water was cold (13°C), and most abundant in September 2006, when the lake water was warmest (30°C). The maximum values for these species were higher than reported previously for the lake by severalfold to orders of magnitude. The only variable consistently correlated with total vibrio abundance within a single sampling was distance from shore (P = 0.000). Multiple linear regression of the entire data set revealed that distance from shore, temperature, and turbidity together explained 82.1% of the variability in total vibrio CFU. The log-transformed mean abundance of V. vulnificus CFU in the lake was significantly correlated with temperature (P = 0.014), but not salinity (P = 0.625). Virulence-associated genes of V. cholerae (ctx) and V. parahaemolyticus (trh and tdh) were not detected in any isolates of these species (n = 128 and n = 20, respectively). In contrast, 16S rRNA typing of V. vulnificus (n = 298) revealed the presence of both environmental (type A) and clinical (type B) strains. The percentage of the B-type V. vulnificus was significantly higher in the lake in October 2005 (35.8% of the total) than at other sampling times (P ≤ 0.004), consistent with the view that these strains represent distinct ecotypes.

  15. Modeling and forecasting the distribution of Vibrio vulnificus in Chesapeake Bay.

    Science.gov (United States)

    Jacobs, J M; Rhodes, M; Brown, C W; Hood, R R; Leight, A; Long, W; Wood, R

    2014-11-01

    To construct statistical models to predict the presence, abundance and potential virulence of Vibrio vulnificus in surface waters of Chesapeake Bay for implementation in ecological forecasting systems. We evaluated and applied previously published qPCR assays to water samples (n = 1636) collected from Chesapeake Bay from 2007-2010 in conjunction with State water quality monitoring programmes. A variety of statistical techniques were used in concert to identify water quality parameters associated with V. vulnificus presence, abundance and virulence markers in the interest of developing strong predictive models for use in regional oceanographic modeling systems. A suite of models are provided to represent the best model fit and alternatives using environmental variables that allow them to be put to immediate use in current ecological forecasting efforts. Environmental parameters such as temperature, salinity and turbidity are capable of accurately predicting abundance and distribution of V. vulnificus in Chesapeake Bay. Forcing these empirical models with output from ocean modeling systems allows for spatially explicit forecasts for up to 48 h in the future. This study uses one of the largest data sets compiled to model Vibrio in an estuary, enhances our understanding of environmental correlates with abundance, distribution and presence of potentially virulent strains and offers a method to forecast these pathogens that may be replicated in other regions. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  16. Vibrio vulnificus Type 6 Secretion System 1 Contains Anti-Bacterial Properties.

    Directory of Open Access Journals (Sweden)

    Selina R Church

    Full Text Available Vibrio vulnificus is a bacterium responsible for severe gastroenteritis, sepsis and wound infections. Gastroenteritis and sepsis are commonly associated with the consumption of raw oysters, whereas wound infection is often associated with the handling of contaminated fish. Although classical virulence factors of this emerging pathogen are well characterised, there remains a paucity of knowledge regarding the general biology of this species. To investigate the presence of previously unreported virulence factors, we applied whole genome sequencing to a panel of ten V. vulnificus strains with varying virulence potentials. This identified two novel type 6 secretion systems (T6SSs, systems that are known to have a role in bacterial virulence and population dynamics. By utilising a range of molecular techniques and assays we have demonstrated the functionality of one of these T6SSs. Furthermore, we have shown that this system is subject to thermoregulation and is negatively regulated by increasing salinity concentrations. This secretion system was also shown to be involved in the killing of V. vulnificus strains that did not possess this system and a model is proposed as to how this interaction may contribute to population dynamics within V. vulnificus strains. In addition to this intra-species killing, this system also contributes to the killing of inter bacterial species and may have a role in the general composition of Vibrio species in the environment.

  17. Power plays: iron transport and energy transduction in pathogenic vibrios.

    Science.gov (United States)

    Kustusch, Ryan J; Kuehl, Carole J; Crosa, Jorge H

    2011-06-01

    The Vibrios are a unique group of bacteria inhabiting a vast array of aquatic environments. Many Vibrio species are capable of infecting a wide assortment of hosts. Some of these species include V. parahaemolyticus, V. alginolyticus, V. vulnificus, V. anguillarum, and V. cholerae. The ability of these organisms to utilize iron is essential in establishing both an infection in their hosts as well as surviving in the environment. Bacteria are able to sequester iron through the secretion of low molecular weight iron chelators termed siderophores. The iron-siderophore complexes are bound by specific outer membrane receptors and are brought through both the outer and inner membranes of the cell. The energy needed to drive this active transport is achieved through the TonB energy transduction system. When first elucidated in E. coli, the TonB system was shown to be a three protein complex consisting of TonB, ExbB and ExbD. Most Vibrio species carry two TonB systems. The second TonB system includes a fourth protein; TtpC, which is essential for TonB2 mediated iron transport. Some Vibrio species have been shown to carry a third TonB system that also includes a TtpC protein.

  18. 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 ...

  19. Vibrio vulnificus-infektioner i Danmark sommeren 1994

    DEFF Research Database (Denmark)

    Bruun, Brita Grønbech; Frimodt-Møller, N; Dalsgaard, A.

    1996-01-01

    The clinical manifestations and epidemiological data of 11 patients infected with Vibrio vulnificus found in Denmark during the unusually warm summer of 1994 are reported. All patients had been exposed to seawater prior to illness, but none had consumed seafood. Nine patients, including four...

  20. Genome sequence of the human pathogen Vibrio cholerae Amazonia.

    NARCIS (Netherlands)

    Thompson, C.C.; Marin, M.A.; Dias, G.M.; Dutilh, B.E.; Edwards, R.A.; Iida, T.; Thompson, F.L.; Vicente, A.C.

    2011-01-01

    Vibrio cholerae O1 Amazonia is a pathogen that was isolated from cholera-like diarrhea cases in at least two countries, Brazil and Ghana. Based on multilocus sequence analysis, this lineage belongs to a distinct profile compared to strains from El Tor and classical biotypes. The genomic analysis

  1. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    A rapid and sensitive assay was developed for the detection of low numbers of viable Vibrio cholerae and Shigella spp. cells in environmental and drinking water samples. Water samples were filtered, and the filters were enriched in a non-selective medium. The enrichment cultures were prepared for polymerase chain ...

  2. 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 serogroup...

  3. 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 ...

  4. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    DRINIE

    2003-04-02

    Apr 2, 2003 ... A rapid and sensitive assay was developed for the detection of low numbers of viable Vibrio cholerae and Shigella spp. cells in environmental and drinking water samples. Water samples were filtered, and the filters were enriched in a non-selective medium. The enrichment cultures were prepared for ...

  5. 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.

  6. Detection and confirmation of toxigenic Vibrio cholerae O1 in ...

    African Journals Online (AJOL)

    Epidemic cholera caused by toxigenic Vibrio cholerae O1 is a major health problem in several developing countries. Traditional methods for identifying V. cholerae involve cultural, biochemical and immunological assays which are cumbersome and often take several days to complete. In the present study, a direct cell ...

  7. 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) ...

  8. Ion-swimming speed variation of Vibrio cholerae cells

    Indian Academy of Sciences (India)

    In the present work we report the variation in swimming speed of Vibrio cholerae with respect to the change in concentration of sodium ions in the medium. We have also studied the variation in swimming speed with respect to temperature. We find that the swimming speed initially shows a linear increase with the increase of ...

  9. 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 ...

  10. Detection and confirmation of toxigenic Vibrio cholerae O1 in ...

    African Journals Online (AJOL)

    2013-08-20

    Aug 20, 2013 ... Epidemic cholera caused by toxigenic Vibrio cholerae O1 is a major health problem in several developing countries. Traditional methods for identifying V. cholerae involve cultural, biochemical and immunological assays which are cumber- some and often take several days to complete. In the present study, ...

  11. 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 ...

  12. Prevalence of Vibrio cholerae in rivers of Mpumalanga province ...

    African Journals Online (AJOL)

    Cholera is a life-threatening diarrhoeal disease, which mainly affects inhabitants of developing countries due to poor socio-economic conditions and lack of access to potable water and sanitation. Toxigenic Vibrio cholerae are the aetiological agents of cholera. These bacteria are autochthonous to aquatic environments, ...

  13. 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...

  14. Evaluation of in vitro Vibrio static activity of Shewanella algae ...

    African Journals Online (AJOL)

    conventional methods followed by Biolog microlog software. Since production of antagonistic agents rely on cultural conditions, antagonistic ability of candidate probioic against the mentioned Vibrios was assessed using Response Surface Methodology, with central composite design in which four independents variables ...

  15. 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...

  16. Exposure of gnotobiotic Artemia franciscana larvae to abiotic stress promotes heat shock protein 70 synthesis and enhances resistance to pathogenic Vibrio campbellii

    Science.gov (United States)

    Pineda, Carlos; MacRae, Thomas H.; Sorgeloos, Patrick; Bossier, Peter

    2008-01-01

    Larvae of the brine shrimp Artemia franciscana serve as important feed in fish and shellfish larviculture; however, they are subject to bacterial diseases that devastate entire populations and consequently hinder their use in aquaculture. Exposure to abiotic stress was shown previously to shield Artemia larvae against infection by pathogenic Vibrio, with the results suggesting a mechanistic role for heat shock protein 70. In the current report, combined hypothermic/hyperthermic shock followed by recovery at ambient temperature induced Hsp70 synthesis in Artemia larvae. Thermotolerance was also increased as was protection against infection by Vibrio campbellii, the latter indicated by reduced mortality and lower bacterial load in challenge tests. Resistance to Vibrio improved in the face of declining body mass as demonstrated by measurement of ash-free dry weight. Hypothermic stress only and acute osmotic insult did not promote Hsp70 expression and thermotolerance in Artemia larvae nor was resistance to Vibrio challenge augmented. The data support a causal link between Hsp70 accumulation induced by abiotic stress and enhanced resistance to infection by V. campbellii, perhaps via stimulation of the Artemia immune system. This possibility is now under investigation, and the work may reveal fundamental properties of crustacean immunity. Additionally, the findings are important in aquaculture where development of procedures to prevent bacterial infection of feed stock such as Artemia larvae is a priority. PMID:18347942

  17. 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

  18. Evaluation of Cholera Toxin Expression in Different Populations of Vibrio cholera

    OpenAIRE

    Sedigheh Ebrahimi Kasgari; Mahnaz Nourani; Yousef Yahyapour; Seyed Ehsanollah Mousavi; Enayatollah Kalantar; Hami Kaboosi; Seyed Mahmoud Amin Marashi

    2015-01-01

    Background: Cholera is one of the most diseases of human. Cholera toxin is the most important pathogenic factor in humans that causes diarrhea. The cholera toxin is produced by V. cholerae and CTXфPhage. Objectives: In this study, we have investigated the production cholera toxin with different density of Vibrio cholerae. Materials and Methods: With this propose we inoculated classical strain O1 of Vibrio cholerae ATCC 14035 and Vibrio cholerae O1biovar El Tor N16961 into th...

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

    OpenAIRE

    Gracia-Valenzuela M.H.; Vergara-Jiménez M.J.; Baez-Flores M.E.; Cabrera-Chavez F.

    2014-01-01

    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

  20. Intussusception in a young female with Vibrio gastroenteritis and diabetic ketoacidosis.

    Science.gov (United States)

    Koh, Jin Shin; Hahm, Jong Ryeal; Jung, Jung Hwa; Jung, Tae Sik; Rhyu, Seung Seok; Moon, Sung Won; Kang, Mi Yeon; Ahn, Yong Jun; Kim, Sun Joo; Chung, Soon Ii

    2007-01-01

    The incidence of functional intussusception is extremely rare in adults. A 23-year-old woman, previously diagnosed with type 1 diabetes mellitus (DM), complained of colicky abdominal pain associated with vomiting of 1-day duration. Currant jelly stool was observed. Irrespective of hydration and intravenous insulin injection under the diagnosis of diabetic ketoacidosis (DKA), her abdominal pain and laboratory parameters did not improve. Abdominal computerized tomography (CT) revealed a jejunojejunal intussusception. We maintained large-volume fluid administration, and her abdominal pain began to subside. The stool culture was positive for Vibrio parahaemolyticus. We confirm the intussusception that was resolved by supportive management without surgical intervention in a patient with gastroenteritis and diabetic ketoacidosis.

  1. Vibrio cholerae non-O1, non-O139 bacteraemia associated with pneumonia, Italy 2016.

    Science.gov (United States)

    Marinello, Serena; Marini, Giulia; Parisi, Giancarlo; Gottardello, Lorena; Rossi, Lucia; Besutti, Valeria; Cattelan, Anna Maria

    2017-04-01

    This paper describes an elderly male patient, living in the Veneto Region, Italy, who developed Vibrio cholerae bacteraemia and pneumonia. Some days previously, while on holiday in the Lagoon of Venice, he had been collecting clams in seawater, during which he suffered small abrasions of the skin. On admission to hospital, he was confused, had fever and a cough, but neither diarrhoea nor signs of gastroenteritis were found. Both blood and stool cultures grew V. cholerae of non-O1 non-O-139 type, and the patient recovered after prompt administration of intravenous ceftriaxone for 2 weeks. This clinical case emphasises the role of global warming and climate changes in causing increasing numbers of water-borne infections.

  2. Memory B Cell Responses to Vibrio cholerae O1 Lipopolysaccharide Are Associated with Protection against Infection from Household Contacts of Patients with Cholera in Bangladesh

    OpenAIRE

    Patel, Sweta M.; Rahman, Mohammad Arif; Mohasin, M.; Riyadh, M. Asrafuzzaman; Leung, Daniel T.; Alam, Mohammad Murshid; Chowdhury, Fahima; Ashraful I Khan; Weil, Ana A.; Aktar, Amena; Nazim, Mohammad; Regina C LaRocque; Edward T Ryan; Calderwood, Stephen B.; Qadri, Firdausi

    2012-01-01

    Vibrio cholerae O1 causes cholera, a dehydrating diarrheal disease. We have previously shown that V. cholerae-specific memory B cell responses develop after cholera infection, and we hypothesize that these mediate long-term protective immunity against cholera. We prospectively followed household contacts of cholera patients to determine whether the presence of circulating V. cholerae O1 antigen-specific memory B cells on enrollment was associated with protection against V. cholerae infection ...

  3. VibrioBase: A Model for Next-Generation Genome and Annotation Database Development

    Directory of Open Access Journals (Sweden)

    Siew Woh Choo

    2014-01-01

    Full Text Available To facilitate the ongoing research of Vibrio spp., a dedicated platform for the Vibrio research community is needed to host the fast-growing amount of genomic data and facilitate the analysis of these data. We present VibrioBase, a useful resource platform, providing all basic features of a sequence database with the addition of unique analysis tools which could be valuable for the Vibrio research community. VibrioBase currently houses a total of 252 Vibrio genomes developed in a user-friendly manner and useful to enable the analysis of these genomic data, particularly in the field of comparative genomics. Besides general data browsing features, VibrioBase offers analysis tools such as BLAST interfaces and JBrowse genome browser. Other important features of this platform include our newly developed in-house tools, the pairwise genome comparison (PGC tool, and pathogenomics profiling tool (PathoProT. The PGC tool is useful in the identification and comparative analysis of two genomes, whereas PathoProT is designed for comparative pathogenomics analysis of Vibrio strains. Both of these tools will enable researchers with little experience in bioinformatics to get meaningful information from Vibrio genomes with ease. We have tested the validity and suitability of these tools and features for use in the next-generation database development.

  4. FURTHER STUDIES ON THE ETIOLOGICAL ROLE OF VIBRIO FETUS.

    Science.gov (United States)

    Smith, T; Little, R B; Taylor, M S

    1920-11-30

    The data bearing on these three cases are quite sufficient to rule out Bacillus abortus as the agent. Not only the cultures and guinea pig tests of fetal tissues and contents of the digestive tract, but also the agglutination and guinea pig tests of the milk, were negative. The same is true of the agglutination tests of the blood serum. Only in one case was the placenta obtained in part. The stained films and the sections from various regions showed no abortion bacilli. Guinea pig tests of placental tissue were negative for Bacillus abortus. On the other hand) minute organisms resembling vibrios were detected in the cytoplasm of endothelial cells within capillaries in the edematous subchorionic tissue. Subsequently the agglutination titer of the blood serum of one of these cases rose to a level indicating infection with Bacillus abortus during the second pregnancy. The peculiar distribution of abortions due to Vibrio fetus among older cows and heifers in this herd, resulting at first in cases among older cows and latterly passing to young stock, may be explained by certain occurrences in the herd itself. It may be assumed that the infection was originally brought in by purchased cows. The young stock is kept segregated from these in a special barn, and when 6 months old it is pastured on outlying farms until returned in an advanced stage of pregnancy. The heifers during the first pregnancy were thus kept away from vibrio carriers until after the first calf was born. In June and July, 1919, 55 older cows, purchased and native, were placed on the young stock pasture. The three cases of abortion in heifers due to Vibrio fetus occurred October 24, November 9, and December 2, 1919. The age and condition of the fetuses accord very well with the assumption that Vibrio fetus was introduced among the young stock in June or July of the same year. The information gathered thus far concerning vibrionic abortion in this herd enables us to formulate a tentative hypothesis

  5. 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...

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

    Science.gov (United States)

    Madec, Stéphanie; Pichereau, Vianney; Jacq, Annick; Paillard, Mathieu; Boisset, Claire; Guérard, Fabienne; Paillard, Christine; Nicolas, Jean-Louis

    2014-01-01

    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.

  7. Mutation of Bacterium Vibrio gazogenes for Selective Preparation of Colorants

    OpenAIRE

    Alihosseini, Farzaneh; Lango, Jozsef; Ju, Kou-San; Hammock, Bruce D.; Sun, Gang

    2010-01-01

    A novel marine bacterium strain effectively produced prodiginine type pigments. These colorants could dye wool, silk and synthetic fabrics such as polyester and polyacrylic and also show antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria on the dyed products. Methyl nitrosoguanidine was used as a mutation agent to increase the genetic diversity and the production yield of the bacteria of the family of Vibrio gazogenes. The analysis of the mutated samples show...

  8. Wind direction and its linkage with Vibrio cholerae dissemination.

    Science.gov (United States)

    Paz, Shlomit; Broza, Meir

    2007-02-01

    The relevance of climatic events as causative factors for cholera epidemics is well known. However, examinations of the involvement of climatic factors in intracontinental disease distribution are still absent. The spreading of cholera epidemics may be related to the dominant wind direction over land. We examined the geographic diffusion of three cholera outbreaks through their linkage with the wind direction: a) the progress of Vibrio cholerae O1 biotype El Tor in Africa during 1970-1971 and b) again in 2005-2006; and c) the rapid spread of Vibrio cholerae O139 over India during 1992-1993. We also discuss the possible influence of the wind direction on windborn dissemination by flying insects, which may serve as vectors. Analysis of air pressure data at sea level and at several altitudes over Africa, India, and Bangladesh show a correspondence between the dominant wind direction and the intracontinental spread of cholera. We explored the hypothesis that winds have assisted the progress of cholera Vibrios throughout continents. The current analysis supports the hypothesis that aeroplankton (the tiny life forms that float in the air and that may be caught and carried upward by the wind, landing far from their origin) carry the cholera bacteria from one body of water to an adjacent one. This finding may improve our understanding of how climatic factors are involved in the rapid distribution of new strains throughout a vast continental area. Awareness of the aerial transfer of Vibrio cholerae may assist health authorities by improving the prediction of the disease's geographic dissemination.

  9. Adsorption kinetics of laterally and polarly flagellated Vibrio.

    OpenAIRE

    Belas, M R; Colwell, R R

    1982-01-01

    The adsorption of laterally and polarly flagellated bacteria to chitin was measured, and from the data obtained, a modified Langmuir adsorption isotherm was derived. Results indicated that the adsorption of laterally flagellated Vibrio parahaemolyticus follows the Langmuir adsorption isotherm, a type of adsorption referred to as surface saturation kinetics, when conditions are favorable for the production of lateral flagella. When conditions were not favorable for the production of lateral fl...

  10. A Symposium on Bioluminescence and Chemiluminescence.

    Science.gov (United States)

    1998-01-01

    in marine Vibrio . (25 min) B.L. Bassler (US) • The Vibrio fischeri LuxR-LuxI system, a model for quorum sensing in Gram-negative bacteria. (20 min...The Euprymna scolopes/ Vibrio fischeri symbiosis. The squid says: Margaret McFall-Ngai (US) The bacterium responds: Edward Ruby (US) MIXER: Meigs...Education Co-chairs: S. Albrecht (Germany) and J.D. Andrade (US) • Transformation experiment using bioluminescence genes of Vibrio fischeri as a

  11. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

    Science.gov (United States)

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

    2015-05-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe3O4)) 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 Fe3O4 and CA-Fe3O4/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 Fe3O4, CA-Fe3O4 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 (Fe3O4) and 189.51 nm (CA-Fe3O4) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe2O3/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.

  12. Vibrio vulnificus infection in Southern Brazil - Case report Infecção por Vibrio vulnificus no sul do Brasil - Relato de caso

    Directory of Open Access Journals (Sweden)

    João César Beenke França

    2013-06-01

    Full Text Available The genus Vibrio is a member of the family Vibrionaceae, and among their disease-causing species, Vibrio vulnificus, a lactose-positive gram-negative bacillus, is one of the most virulent pathogen of the noncholerae vibrios. We describe the case of a 39-year-old male patient, who was using immunosuppressive therapy, admitted to the hospital for liver transplantation. Twelve hours later, the patient presented high fever, myalgia, anuria and erythematous plaques on lower limbs, of rapid growth and proximal progression. The patient was treated with ceftriaxone, meropenem and oxacillin, however he expired within 30 hours. Blood cultures showed growth of a gram-negative bacillus, which was later identified as Vibrio vulnificus.O gênero Vibrio é membro da família Vibrionaceae, e entre as espécies patogênicas, Vibrio vulnificus, bacilo gram negativo lactose positivo, tem sido frequentemente citado. Descrevemos o caso de um paciente masculino de 39 anos, em uso de medicação imunossupressora, admitido no hospital para transplante hepático. Doze horas após a internação, o paciente evoluiu com febre, mialgias, anúria e placas eritematosas em membros inferiores, com rápido crescimento e evolução proximal. O paciente foi tratado com ceftriaxona, meropenem e oxacilina sem melhora, evoluindo para óbito em 30 horas. Hemocultura mostrou crescimento de bacilo gram negativo posteriormente identificado como Vibrio vulnificus.

  13. Evolutionary dynamics of Vibrio cholerae O1 following a single-source introduction to Haiti.

    Science.gov (United States)

    Katz, Lee S; Petkau, Aaron; Beaulaurier, John; Tyler, Shaun; Antonova, Elena S; Turnsek, Maryann A; Guo, Yan; Wang, Susana; Paxinos, Ellen E; Orata, Fabini; Gladney, Lori M; Stroika, Steven; Folster, Jason P; Rowe, Lori; Freeman, Molly M; Knox, Natalie; Frace, Mike; Boncy, Jacques; Graham, Morag; Hammer, Brian K; Boucher, Yan; Bashir, Ali; Hanage, William P; Van Domselaar, Gary; Tarr, Cheryl L

    2013-07-02

    Prior to the epidemic that emerged in Haiti in October of 2010, cholera had not been documented in this country. After its introduction, a strain of Vibrio cholerae O1 spread rapidly throughout Haiti, where it caused over 600,000 cases of disease and >7,500 deaths in the first two years of the epidemic. We applied whole-genome sequencing to a temporal series of V. cholerae isolates from Haiti to gain insight into the mode and tempo of evolution in this isolated population of V. cholerae O1. Phylogenetic and Bayesian analyses supported the hypothesis that all isolates in the sample set diverged from a common ancestor within a time frame that is consistent with epidemiological observations. A pangenome analysis showed nearly homogeneous genomic content, with no evidence of gene acquisition among Haiti isolates. Nine nearly closed genomes assembled from continuous-long-read data showed evidence of genome rearrangements and supported the observation of no gene acquisition among isolates. Thus, intrinsic mutational processes can account for virtually all of the observed genetic polymorphism, with no demonstrable contribution from horizontal gene transfer (HGT). Consistent with this, the 12 Haiti isolates tested by laboratory HGT assays were severely impaired for transformation, although unlike previously characterized noncompetent V. cholerae isolates, each expressed hapR and possessed a functional quorum-sensing system. Continued monitoring of V. cholerae in Haiti will illuminate the processes influencing the origin and fate of genome variants, which will facilitate interpretation of genetic variation in future epidemics. Vibrio cholerae is the cause of substantial morbidity and mortality worldwide, with over three million cases of disease each year. An understanding of the mode and rate of evolutionary change is critical for proper interpretation of genome sequence data and attribution of outbreak sources. The Haiti epidemic provides an unprecedented opportunity to

  14. Biochemical properties and evaluation of washing performance in commercial detergent compatibility of two collagenolytic serine peptidases secreted by Aspergillus fischeri and Penicillium citrinum.

    Science.gov (United States)

    Ida, Érika Lika; da Silva, Ronivaldo Rodrigues; de Oliveira, Tássio Brito; Souto, Tatiane Beltramini; Leite, Juliana Abigail; Rodrigues, André; Cabral, Hamilton

    2017-03-16

    Filamentous fungi secrete diverse peptidases with different biochemical properties, which is of considerable importance for application in various commercial sectors. In this study, we describe the isolation of two fungal species collected from the soil of decayed organic matter: Aspergillus fischeri and Penicillium citrinum. In a submerged bioprocess, we observed better peptidase production with the fungus P. citrinum, which reached a peak production at 168 h with 760 U/mL, in comparison with the fungus A. fischeri, which reached a peak production at 72 h with 460 U/mL. In both situations, the fermentative medium contained 0.5% crushed feathers as a source of nitrogen. On performing biochemical characterization, we detected two alkaline serine peptidases: The one secreted by P. citrinum had optimal activity at pH 7.0 and at 45°C, while the one secreted by A. fischeri had optimal activity in pH 6.5-8 and at 55-60°C. Metallic ions were effective in modulating these peptidases; in particular, Cu(2+) promoted negative modulation of both peptidases. The peptidases were stable and functional under conditions of nonionic surfactants, temperatures up to 45°C for 1 h, and incubation over a wide pH range. In addition, it was observed that both peptidases had the capacity to hydrolyze collagen and performed well in removing an egg protein stain when supplemented into a commercial powder detergent; this was especially true for the peptidase from P. citrinum.

  15. 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.

  16. 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.

  17. The Occurrence of Vibrio species in the Gut of Sardinella madrensis ...

    African Journals Online (AJOL)

    The occurrence of vibrio bacteria in the gut of “Songu”: Sardinella madrensis was investigated using enrichment procedures. Seventy percent (70%) of the total fish samples examined were positive for vibrios. The mean bacterial counts ranged between 2.68 x 102 to 1.30 x 104 cfu/g in all the fish samples. The weight of fish ...

  18. Onderzoek pathogene vibrio soorten in Nederlandse mosselen en oesters in augustus en september 2003

    NARCIS (Netherlands)

    Aalberts, C.H.J.

    2003-01-01

    Naar aanleiding van de hoge weerstemperatuur in augustus 2003 zijn in de kweek- en verwatergebieden van mosselen en oesters in Nederland enkele monsters onderzocht op de aanwezigheid van voor de mens pathogene vibrio soorten. In geen van de 18 monsters is Vibrio parahaemolyticus, vulnificus of

  19. Effects of Pollution on Vibrios in Woji River OJESANMI, A S; IBE, S N ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    ABSTRACT: 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.

  20. 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 ...

  1. Impact of milk fish farming in the tropics on potentially pathogenic vibrios.

    Science.gov (United States)

    Reichardt, W T; Reyes, J M; Pueblos, M J; Lluisma, A O

    2013-12-15

    Ratios of sucrose-negative to sucrose-positive vibrios on TCBS agar (suc-/suc+) indicate the abundance of potential human pathogenic non-cholera vibrios in coastal mariculture environments of the Lingayen Gulf (Philippines. In guts of adult maricultured milkfish (Chanos chanos) of suc- vibrios reached extreme peak values ranging between 2 and 545 million per g wet weight. Suc- vibrios outnumbered suc+ vibrios in anoxic sediments, too, and were rarely predominant in coastal waters or in oxidized sediments. Suc-/suc+ ratios in sediments increased toward the mariculture areas with distance from the open sea at decreasing redox potentials. There is circumstantial evidence that suc- vibrios can be dispersed from mariculture areas to adjacent environments including coral reefs. An immediate human health risk by pathogenic Vibrio species is discounted, since milkfish guts contained mainly members of the Enterovibrio group. A representative isolate of these contained proteolytic and other virulence factors, but no genes encoding toxins characteristic of clinical Vibrio species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Complete genome sequence for the shellfish pathogen Vibrio coralliilyticus RE98 isolated from a shellfish hatchery

    Science.gov (United States)

    Vibrio coralliilyticus is a pathogen of corals and larval shellfish. Publications on strain RE98 list it as a Vibrio tubiashii; however, whole genome sequencing confirms RE98 as V. coralliilyticus containing a total of 6,037,824 bp consisting of two chromosomes (3,420,228 and 1,917,482 bp), and two...

  3. 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

  4. 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

  5. Comparative assessment of Vibrio virulence in marine fish larvae

    DEFF Research Database (Denmark)

    Rønneseth, A.; Castillo, D.; D'Alvise, Paul

    2017-01-01

    Vibrionaceae infections are a major obstacle for marine larviculture; however, little is known about virulence differences of Vibrio strains. The virulence of Vibrio strains, mostly isolated from vibriosis outbreaks in farmed fish, was tested in larval challenge trials with cod (Gadus morhua...... effects on survival. Some Vibrio strains were pathogenic in all of the larva species, while some caused disease only in one of the species. Twenty-nine of the Vibrio anguillarum strains increased the mortality of larvae from at least one fish species; however, pathogenicity of the strains differed...... markedly. Other Vibrio species had no or less pronounced effects on larval mortalities. Iron uptake has been related to V. anguillarum virulence; however, the presence or absence of the plasmid pJM1 encoding anguibactin did not correlate with virulence. The genomes of V. anguillarum were compared (D...

  6. 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.

  7. 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...

  8. Occurrence and Diversity of Clinically Important Vibrio Species in the Aquatic Environment of Georgia.

    Science.gov (United States)

    Kokashvili, Tamar; Whitehouse, Chris A; Tskhvediani, Ana; Grim, Christopher J; Elbakidze, Tinatin; Mitaishvili, Nino; Janelidze, Nino; Jaiani, Ekaterine; Haley, Bradd J; Lashkhi, Nino; Huq, Anwar; Colwell, Rita R; Tediashvili, Marina

    2015-01-01

    Among the more than 70 different Vibrio species inhabiting marine, estuarine, and freshwater ecosystems, 12 are recognized as human pathogens. The warm subtropical climate of the Black Sea coastal area and inland regions of Georgia likely provides a favorable environment for various Vibrio species. From 2006 to 2009, the abundance, ecology, and diversity of clinically important Vibrio species were studied in different locations in Georgia and across seasons. Over a 33-month period, 1,595 presumptive Vibrio isolates were collected from the Black Sea (n = 657) and freshwater lakes around Tbilisi (n = 938). Screening of a subset of 440 concentrated and enriched water samples by PCR-electrospray ionization/mass spectrometry (PCR-ESI/MS) detected the presence of DNA from eight clinically important Vibrio species: V. cholerae, V. parahaemolyticus, V. vulnificus, V. mimicus, V. alginolyticus, V. harveyi, V. metschnikovii, and V. cincinnatiensis. Almost 90% of PCR/ESI-MS samples positive for Vibrio species were collected from June through November. Three important human-pathogenic Vibrio species (V. cholerae, V. parahaemolyticus, and V. vulnificus) were detected in 62.8, 37.8, and 21.4% of samples testing positive for Vibrios, respectively. The results of these activities suggest that natural reservoirs for human-pathogenic Vibrios exist in Georgian aquatic environments. Water temperature at all sampling sites was positively correlated with the abundance of clinically important Vibrio spp. (except V. metschnikovii), and salinity was correlated with species composition at particular Black Sea sites as well as inland reservoirs.

  9. 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.

    2016-01-01

    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 Vibrioafter 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.

  10. Vibrio fujianensis sp. nov., isolated from aquaculture water.

    Science.gov (United States)

    Fang, Yujie; Chen, Aiping; Dai, Hang; Huang, Ying; Kan, Biao; Wang, Duochun

    2018-02-13

    A Gram-stain-negative, facultatively anaerobic strain, designated FJ201301 T , was isolated from aquaculture water collected from Fujian province, China. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain FJ201301 T belonged to the genus Vibrio, formed a distinct cluster with Vibriocincinnatiensis ATCC 35912 T and shared the highest similarity with Vibriosalilacus CGMCC 1.12427 T . A 15 bp insertion found in the 16S rRNA gene was a significant marker that distinguished strain FJ201301 T from several phylogenetic neighbours (e.g. V. cincinnatiensis). Multilocus sequence analysis of eight genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; concatenated 4135 bp sequence) showed that, forming a long and independent phylogenetic branch, strain FJ201301 T clustered with V. cincinnatiensis ATCC 35912 T , Vibrioinjenensis KCTC 32233 T and Vibriometschnikovii CIP 69.14 T clearly separated from V. salilacus CGMCC 1.12427 T . Furthermore, the highest in silico DNA-DNA hybridization and average nucleotide identity values between strain FJ201301 T and the closest related species were 26.3 and 83.1 % with V. cincinnatiensis ATCC 35912 T , less than the proposed cutoff levels for species delineation, i.e. 70 and 95 %, respectively. Biochemical, sequence and genomic analysis suggested the designation of strain FJ201301 T representing a novel species of the genus Vibrio, for which the name Vibrio fujianensis sp. nov. is proposed. The type strain is FJ201301 T (=DSM 104687 T =CGMCC 1.16099 T ).

  11. 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.

  12. Inhibitory Effect of Glycerin on Vibrio parahaemolyticus and Salmonella

    Science.gov (United States)

    Chun, Doki; Seol, Sung Yong; Tak, Ryunbin; Park, Cheong Kyu

    1972-01-01

    In a study of the effect of glycerin in transport media on Vibrio parahaemolyticus and Salmonella, it was found that a concentration of 30% glycerin was highly inhibitory for V. parahaemolyticus and to a lesser degree for Salmonella. The incorporation of peptone or human feces in media did not reduce the inhibitory effect of glycerin. In media with 15% glycerin, viable counts of V. parahaemolyticus and Salmonella increased after 24 hr of incubation both in the presence and absence of feces. Due to the concurrent increase in the total bacterial count in the media containing feces, no enrichment effect was noted. PMID:4565633

  13. 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

  14. New insights into Oculina patagonica coral diseases and their associated Vibrio spp. communities.

    Science.gov (United States)

    Rubio-Portillo, Esther; Yarza, Pablo; Peñalver, Cindy; Ramos-Esplá, Alfonso A; Antón, Josefa

    2014-09-01

    Bleaching of Oculina patagonica has been extensively studied in the Eastern Mediterranean Sea, although no studies have been carried out in the Western basin. In 1996 Vibrio mediterranei was reported as the causative agent of bleaching in O. patagonica but it has not been related to bleached or healthy corals since 2003, suggesting that it was no longer involved in bleaching of O. patagonica. In an attempt to clarify the relationship between Vibrio spp., seawater temperature and coral diseases, as well as to investigate the putative differences between Eastern and Western Mediterranean basins, we have analysed the seasonal patterns of the culturable Vibrio spp. assemblages associated with healthy and diseased O. patagonica colonies. Two sampling points located in the Spanish Mediterranean coast were chosen for this study: Alicante Harbour and the Marine Reserve of Tabarca. A complex and dynamic assemblage of Vibrio spp. was present in O. patagonica along the whole year and under different environmental conditions and coral health status. While some Vibrio spp. were detected all year around in corals, the known pathogens V. mediteranei and V. coralliilyticus were only present in diseased specimens. The pathogenic potential of these bacteria was studied by experimental infection under laboratory conditions. Both vibrios caused diseased signs from 24 °C, being higher and faster at 28 °C. Unexpectedly, the co-inoculation of these two Vibrio species seemed to have a synergistic pathogenic effect over O. patagonica, as disease signs were readily observed at temperatures at which bleaching is not normally observed.

  15. Persistence, seasonal dynamics and pathogenic potential of Vibrio communities from Pacific oyster hemolymph.

    Science.gov (United States)

    Wendling, Carolin C; Batista, Frederico M; Wegner, K Mathias

    2014-01-01

    Bacteria of the genus Vibrio occur at a continuum from free-living to symbiotic life forms, including opportunists and pathogens, that can contribute to severe diseases, for instance summer mortality events of Pacific oysters Crassostrea gigas. While most studies focused on Vibrio isolated from moribund oysters during mortality outbreaks, investigations of the Vibrio community in healthy oysters are rare. Therefore, we characterized the persistence, diversity, seasonal dynamics, and pathogenicity of the Vibrio community isolated from healthy Pacific oysters. In a reciprocal transplant experiment we repeatedly sampled hemolymph from adult Pacific oysters to differentiate population from site-specific effects during six months of in situ incubation in the field. We characterized virulence phenotypes and genomic diversity based on multilocus sequence typing in a total of 70 Vibrio strains. Based on controlled infection experiments we could show that strains with the ability to colonize healthy adult oysters can also have the potential to induce high mortality rates on larvae. Diversity and abundance of Vibrio varied significantly over time with highest values during and after spawning season. Vibrio communities from transplanted and stationary oysters converged over time, indicating that communities were not population specific, but rather assemble from the surrounding environment forming communities, some of which can persist over longer periods.

  16. Assay development and high-throughput screening for small molecule inhibitors of a Vibrio cholerae stress response pathway

    Directory of Open Access Journals (Sweden)

    Stanbery L

    2017-09-01

    Full Text Available Laura Stanbery, Jyl S Matson Department of Medical Microbiology and Immunology, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH, USA Abstract: Antibiotics are important adjuncts to oral rehydration therapy in cholera disease management. However, due to the rapid emergence of resistance to the antibiotics used to treat cholera, therapeutic options are becoming limited. Therefore, there is a critical need to develop additional therapeutics to aid in the treatment of cholera. Previous studies showed that the extracytoplasmic stress response (σE pathway of Vibrio cholerae is required for full virulence of the organism. The pathway is also required for bacterial growth in the presence of ethanol. Therefore, we exploited this ethanol sensitivity phenotype in order to develop a screen for inhibitors of the pathway, with the aim of also inhibiting virulence of the pathogen. Here we describe the optimization and implementation of our high-throughput screening strategy. From a primary screen of over 100,000 compounds, we have identified seven compounds that validated the growth phenotypes from the primary and counterscreens. These compounds have the potential to be developed into therapeutic agents for cholera and will also be valuable probes for uncovering basic molecular mechanisms of an important cause of diarrheal disease. Keywords: Vibrio cholerae, stress response, σE, high-throughput screening

  17. The Vibrio cholerae O139 O-antigen polysaccharide is essential for Ca2+-dependent biofilm development in sea water.

    Science.gov (United States)

    Kierek, Katharine; Watnick, Paula I

    2003-11-25

    Vibrio cholerae is both an inhabitant of estuarine environments and the etiologic agent of the diarrheal disease cholera. Previous work has demonstrated that V. cholerae forms both an exopolysaccharide-dependent biofilm and a Ca2+-dependent biofilm. In this work, we demonstrate a role for the O-antigen polysaccharide of V. cholerae in Ca2+-dependent biofilm development in model and true sea water. Interestingly, V. cholerae biofilms, as well as the biofilms of several other Vibrio species, disintegrate when Ca2+ is removed from the bathing medium, suggesting that Ca2+ is interacting directly with the O-antigen polysaccharide. In the Bay of Bengal, cholera incidence has been correlated with increased sea surface height. Because of the low altitude of this region, increases in sea surface height are likely to lead to transport of sea water, marine particulates, and marine biofilms into fresh water environments. Because fresh water is Ca2+-poor, our results suggest that one potential outcome of an increase is sea surface height is the dispersal of marine biofilms with an attendant increase in planktonic marine bacteria such as V. cholerae. Such a phenomenon may contribute to the correlation of increased sea surface height with cholera.

  18. Vibrio cholerae Represses Polysaccharide Synthesis To Promote Motility in Mucosa

    Science.gov (United States)

    Liu, Zhenyu; Wang, Yuning; Liu, Shengyan; Sheng, Ying; Rueggeberg, Karl-Gustav; Wang, Hui; Li, Jie; Gu, Frank X.; Zhong, Zengtao; Kan, Biao

    2015-01-01

    The viscoelastic mucus layer of gastrointestinal tracts is a host defense barrier that a successful enteric pathogen, such as Vibrio cholerae, must circumvent. V. cholerae, the causative agent of cholera, is able to penetrate the mucosa and colonize the epithelial surface of the small intestine. In this study, we found that mucin, the major component of mucus, promoted V. cholerae movement on semisolid medium and in liquid medium. A genome-wide screen revealed that Vibrio polysaccharide (VPS) production was inversely correlated with mucin-enhanced motility. Mucin adhesion assays indicated that VPS bound to mucin. Moreover, we found that vps expression was reduced upon exposure to mucin. In an infant mouse colonization model, mutants that overexpressed VPS colonized less effectively than wild-type strains in more distal intestinal regions. These results suggest that V. cholerae is able to sense mucosal signals and modulate vps expression accordingly so as to promote fast motion in mucus, thus allowing for rapid spread throughout the intestines. PMID:25561707

  19. Invariant recognition of polychromatic images of Vibrio cholerae 01

    Science.gov (United States)

    Alvarez-Borrego, Josue; Mourino-Perez, Rosa R.; Cristobal, Gabriel; Pech-Pacheco, Jose L.

    2002-04-01

    Cholera is an acute intestinal infectious disease. It has claimed many lives throughout history, and it continues to be a global health threat. Cholera is considered one of the most important emergence diseases due its relation with global climate changes. Automated methods such as optical systems represent a new trend to make more accurate measurements of the presence and quantity of this microorganism in its natural environment. Automatic systems eliminate observer bias and reduce the analysis time. We evaluate the utility of coherent optical systems with invariant correlation for the recognition of Vibrio cholerae O1. Images of scenes are recorded with a CCD camera and decomposed in three RGB channels. A numeric simulation is developed to identify the bacteria in the different samples through an invariant correlation technique. There is no variation when we repeat the correlation and the variation between images correlation is minimum. The position-, scale-, and rotation-invariant recognition is made with a scale transform through the Mellin transform. The algorithm to recognize Vibrio cholerae O1 is the presence of correlation peaks in the green channel output and their absence in red and blue channels. The discrimination criterion is the presence of correlation peaks in red, green, and blue channels.

  20. 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.

  1. Vibrio japonicus sp. nov., a novel member of the Nereis clade in the genus Vibrio isolated from the coast of Japan.

    Science.gov (United States)

    Doi, Hiroyasu; Osawa, Ikuko; Adachi, Hayamitsu; Kawada, Manabu

    2017-01-01

    A novel Vibrio strain, JCM 31412T, was isolated from seawater collected from the Inland Sea (Setonaikai), Japan, and characterized as a Gram-negative, oxidase-positive, catalase-negative, facultatively anaerobic, motile, ovoid-shaped bacterium with one polar flagellum. Based on 16S rDNA gene identity, strain JCM 31412T showed a close relationship with type strains of Vibrio brasiliensis (LMG 20546T, 98.2% identity), V. harveyi (NBRC 15634T, 98.2%), V. caribbeanicus (ATCC BAA-2122T, 97.8%) and V. proteolyticus (NBRC 13287T, 97.8%). The G+C content of strain JCM 31412T DNA was 46.8%. Multi-locus sequence analysis (MLSA) of eight loci (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; 5535bp) further clustered strain JCM 31412T in the Nereis clade, genus Vibrio. Phenotypically, strain JCM 31412T differed from the closest related Vibrio species in its utilization of melibiose and raffinose, and its lack of casein and gelatin hydrolysis. It was further differentiated based on its fatty acid composition, specifically properties of C12:03OH and summed features, which were significantly different from those of V. brasiliensis, V. nigripulchritudo and V. caribbeanicus type strains. Overall, the results of DNA-DNA hybridization, and physiological and biochemical analysis differentiated strain JCM 31412T from other described species of the genus Vibrio. Based on these polyphasic taxonomic findings, it was therefore concluded that JCM 31412T was a novel Vibrio species, for which the name Vibrio japonicus sp. nov. was proposed, with JCM 31412T (= LMG 29636T = ATCC TSD-62T) as the type strain.

  2. Vibrio japonicus sp. nov., a novel member of the Nereis clade in the genus Vibrio isolated from the coast of Japan.

    Directory of Open Access Journals (Sweden)

    Hiroyasu Doi

    Full Text Available A novel Vibrio strain, JCM 31412T, was isolated from seawater collected from the Inland Sea (Setonaikai, Japan, and characterized as a Gram-negative, oxidase-positive, catalase-negative, facultatively anaerobic, motile, ovoid-shaped bacterium with one polar flagellum. Based on 16S rDNA gene identity, strain JCM 31412T showed a close relationship with type strains of Vibrio brasiliensis (LMG 20546T, 98.2% identity, V. harveyi (NBRC 15634T, 98.2%, V. caribbeanicus (ATCC BAA-2122T, 97.8% and V. proteolyticus (NBRC 13287T, 97.8%. The G+C content of strain JCM 31412T DNA was 46.8%. Multi-locus sequence analysis (MLSA of eight loci (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; 5535bp further clustered strain JCM 31412T in the Nereis clade, genus Vibrio. Phenotypically, strain JCM 31412T differed from the closest related Vibrio species in its utilization of melibiose and raffinose, and its lack of casein and gelatin hydrolysis. It was further differentiated based on its fatty acid composition, specifically properties of C12:03OH and summed features, which were significantly different from those of V. brasiliensis, V. nigripulchritudo and V. caribbeanicus type strains. Overall, the results of DNA-DNA hybridization, and physiological and biochemical analysis differentiated strain JCM 31412T from other described species of the genus Vibrio. Based on these polyphasic taxonomic findings, it was therefore concluded that JCM 31412T was a novel Vibrio species, for which the name Vibrio japonicus sp. nov. was proposed, with JCM 31412T (= LMG 29636T = ATCC TSD-62T as the type strain.

  3. Occurrence of Vibrio species, beta-lactam resistant Vibrio species, and indicator bacteria in ballast and port waters of a tropical harbor.

    Science.gov (United States)

    Ng, Charmaine; Goh, Shin Giek; Saeidi, Nazanin; Gerhard, William A; Gunsch, Claudia K; Gin, Karina Yew Hoong

    2018-01-01

    Ballast water discharges are potential sources for the spread of invasive and pathogenic aquatic organisms. Ballast waters from six ships docked in the Port of Singapore were tested to determine if indictor organisms fell within proposed standards for ballast water discharge according to regulation D-2 of the Ballast Water Management Convention (BWMC) guidelines. Vibrio species were cultured on media supplemented with beta-lactam antibiotics to determine the presence of antibiotic resistant Vibrio species in the ballast waters of these vessels. Indicator organisms were quantified using culture media Colilert-18 and Enterolert in ballast waters of six ships docked in a tropical harbor, with uptake from different geographical locations. Of the six ships, one had ballast water originating from the Persian Gulf, another from the East China Sea, and four from the South China Sea. Two of the six ships which carried ballast waters from the East China Sea and the South China Sea did not meet the D-2 stipulated requirements of the Ballast Water Management Convention for indicator organisms with Enterococci values more than three times higher than the acceptable limit of 110 MPN/100mL), and Vibrio parahaemolyticus (2 to >110 MPN/100mL) were detected in at least one of six ballast water samples. Using thiosulfate-citrate-bile salts-sucrose agar (TCBS) supplemented with beta-lactam antibiotics (meropenem, ceftazidime), 11 different Vibrio species, exhibiting resistance to beta-lactam antibiotics were isolated; with Vibrio campbellii (44%) and Vibrio alginolyticus (15%) the most detected antibiotic resistant Vibrio species. A practical approach of prioritized screening of high-risk vessels should be conducted to ensure that the water quality meets D-2 standards prior to discharge. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. 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.

  5. Proteolytic inactivation of luciferases from three species of luminous marine bacteria, Beneckea harveyi, Photobacterium fischeri, and Photobacterium phosphoreum: evidence of a conserved structural feature.

    Science.gov (United States)

    Holzman, T F; Baldwin, T O

    1980-01-01

    Upon limited proteolysis of luciferases from the luminous marine bacteria Photobacterium fischeri, Photobacterium phosphoreum, and Beneckea harveyi, the rate of loss of luciferase activity is the same as the rate of loss of the heavier subunit of all three enzymes. It thus appears that the larger subunit of the luciferase from P. phosphoreum should be designated alpha based on its apparent homology with the alpha subunits of the luciferases from B. harveyi and P. fischeri. The luciferase from B. harveyi is more sensitive to chymotrypsin than to trypsin; the luciferases of the Photobacterium species are more sensitive to trypsin than to chymotrypsin. Proteolytic inactivation of all three luciferases results from hydrolysis of a few peptide bonds in the alpha subunit; the proteolytic fragments from the three luciferases in 0.50 M phosphate are approximately the same size, indicating that the three enzymes have a protease-labile region at about the same position in the primary structure of their alpha subunits. Phosphate stabilizes all three luciferases against inactivation by proteases. Formation and degradation of intermediate species derived from the alpha subunits are readily observable in all three luciferases. Phosphate alters both the rate of product formation and the sites of peptide bond scission. The beta subunits of the luciferases from the two Photobacterium species, unlike the enzyme of B. harveyi, appear to be degraded in buffers containing low concentrations of phosphate; in high-phosphate buffers, the beta subunits of all three luciferases appear to resist proteases. Analysis of native and chymotrypsin-inactivated P. fischeri and P. phosphoreum luciferases in the analytical ultracentrifuge indicates that, as with B. harveyi luciferase, the products of limited proteolysis do not dissociate under nondenaturing conditions. The fact that the luciferases from evolutionarily diverse species of luminous bacteria have protease-sensitive bonds in the same

  6. Multi-locus variable number tandem repeat analysis of 7th pandemic Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    Lam Connie

    2012-05-01

    Full Text Available Abstract Background Seven pandemics of cholera have been recorded since 1817, with the current and ongoing pandemic affecting almost every continent. Cholera remains endemic in developing countries and is still a significant public health issue. In this study we use multilocus variable number of tandem repeats (VNTRs analysis (MLVA to discriminate between isolates of the 7th pandemic clone of Vibrio cholerae. Results MLVA of six VNTRs selected from previously published data distinguished 66 V. cholerae isolates collected between 1961–1999 into 60 unique MLVA profiles. Only 4 MLVA profiles consisted of more than 2 isolates. The discriminatory power was 0.995. Phylogenetic analysis showed that, except for the closely related profiles, the relationships derived from MLVA profiles were in conflict with that inferred from Single Nucleotide Polymorphism (SNP typing. The six SNP groups share consensus VNTR patterns and two SNP groups contained isolates which differed by only one VNTR locus. Conclusions MLVA is highly discriminatory in differentiating 7th pandemic V. cholerae isolates and MLVA data was most useful in resolving the genetic relationships among isolates within groups previously defined by SNPs. Thus MLVA is best used in conjunction with SNP typing in order to best determine the evolutionary relationships among the 7th pandemic V. cholerae isolates and for longer term epidemiological typing.

  7. Advanced Microbial Taxonomy Combined with Genome-Based-Approaches Reveals that Vibrio astriarenae sp. nov., an Agarolytic Marine Bacterium, Forms a New Clade in Vibrionaceae.

    Directory of Open Access Journals (Sweden)

    Nurhidayu Al-Saari

    Full Text Available Advances in genomic microbial taxonomy have opened the way to create a more universal and transparent concept of species but is still in a transitional stage towards becoming a defining robust criteria for describing new microbial species with minimum features obtained using both genome and classical polyphasic taxonomies. Here we performed advanced microbial taxonomies combined with both genome-based and classical approaches for new agarolytic vibrio isolates to describe not only a novel Vibrio species but also a member of a new Vibrio clade. Two novel vibrio strains (Vibrio astriarenae sp. nov. C7T and C20 showing agarolytic, halophilic and fermentative metabolic activity were isolated from a seawater sample collected in a coral reef in Okinawa. Intraspecific similarities of the isolates were identical in both sequences on the 16S rRNA and pyrH genes, but the closest relatives on the molecular phylogenetic trees on the basis of 16S rRNA and pyrH gene sequences were V. hangzhouensis JCM 15146T (97.8% similarity and V. agarivorans CECT 5085T (97.3% similarity, respectively. Further multilocus sequence analysis (MLSA on the basis of 8 protein coding genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA, and topA obtained by the genome sequences clearly showed the V. astriarenae strain C7T and C20 formed a distinct new clade protruded next to V. agarivorans CECT 5085T. The singleton V. agarivorans has never been included in previous MLSA of Vibrionaceae due to the lack of some gene sequences. Now the gene sequences are completed and analysis of 100 taxa in total provided a clear picture describing the association of V. agarivorans into pre-existing concatenated network tree and concluded its relationship to our vibrio strains. Experimental DNA-DNA hybridization (DDH data showed that the strains C7T and C20 were conspecific but were separated from all of the other Vibrio species related on the basis of both 16S rRNA and pyrH gene phylogenies (e.g., V

  8. Salinity-induced survival strategy of Vibrio cholerae associated with copepods in Cochin backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Thomas, K.U.; Joseph, N.; Raveendran, O.; Nair, S.

    The occurrence of Vibrio cholerae in water, sediment and copepods was studied over a wide range of salinity using conventional and polymerase chain reaction (PCR) techniques in the Cochin backwaters. V. cholerae occurred either as culturable or non-culturable...

  9. Competitive Survival of Escherichia coli, Vibrio cholerae, Salmonella typhimurium and Shigella dysenteriae in Riverbed Sediments

    CSIR Research Space (South Africa)

    Abia, AL

    2016-11-01

    Full Text Available investigated the survival of Escherichia coli, Salmonella enterica ser. Typhimurium, Vibrio cholerae and Shigella dysenteriae in riverbed sediments of the Apies River. Experiments were performed in flow chambers containing three sediment types and connected...

  10. 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...

  11. Vibrio cholerae Detection in Water and Wastewater by Polymerase Chain Reaction Assay

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    Behnaz Barzamini

    2014-11-01

    Full Text Available Background: Vibrio cholerae is a significant human pathogen worldwide and annually causes some cases of deaths. Contaminated water plays an important role in transmission of this pathogen, which indicates the importance of early diagnosis. Objectives: The current study aimed to perform Polymerase Chain Reaction (PCR on water and wastewater samples to determine the detection limit for Vibrio cholerae. Materials and Methods: PCR was performed on the DNA extracted from Vibrio cholerae of the contaminated water and wastewater using ctxA gene specific primers. The accuracy of PCR method to detect these bacteria was also assessed. Results: The result of PCR performed on the extracted DNA showed a specific 241 base pair band. The limit of bacterial detection for water and wastewater were 40 cfu/mL and 81 cfu/mL, respectively. Conclusions: In the current study, PCR performance using the ctxA gene specific primers to detect Vibrio cholerae was found highly accurate and specific.

  12. Genome sequence of vibrio cholerae G4222, a South African clinical isolate

    CSIR Research Space (South Africa)

    Le Rouw, Wouter J

    2013-03-01

    Full Text Available Vibrio cholerae, a Gram-negative pathogen autochthonous to the aquatic environment, is the causative agent of cholera. Here, we report the complete genome sequence of V. cholerae G4222, a clinical isolate from South Africa....

  13. The Toxicity of Mustard and Mustard Lewisite to Terrestrial Organisms

    Science.gov (United States)

    1998-09-24

    sensitivity of Vibrio fischeri to HD and HL was evaluated by testing the 1000 mg!L stock solutions immediately after preparation, to reduce loss of the...enumeration. An attempt was made to expose Vibrio fischeri directly to HD so that exposure to products of rapid hydrolysis could be avoided, by adding...loss of compounds by hydrolysis. Despite apparent insolubility of the products in water, both HD and HL were toxic to Vibrio fischeri . HD toxicity

  14. Oxidation/Biodegradation of Solid Propellants From a 4.2-Inch Chemical Round

    Science.gov (United States)

    2004-11-16

    Microtox (MTX) assay. The MICROTOX assay exposes a bioluminescent marine bacterium ( Vibrio fischeri ) to a sample of unknown toxicity and measuring the...the Microtox values indicates a decrease in the toxicity of the propellant feed to the Vibrio fischeri . This data can be used, as an indicator as to...not only non-toxic but has become nutritive to Vibrio fischeri . The overall effectiveness of the strategy 1 approach for both propellant types

  15. Symbiosis in Marine Luminous Bacteria

    Science.gov (United States)

    1993-01-01

    1992) Detection of the light organ symbiont Vibrio fischeri in Hawaiian seawater using lux gene probes. Appl. Environ. Microbiol. 58:942-947. 3. Lee, K...H., and E.G. Ruby (1993) Evidence of viable but non-culturable symbiotic Vibrio fischeri in Hawaiian seawater. Abstr. Gen. Meet. Amer. Soc...Microbiol. 93:258. 4. Lee, K.-H., and E.G. Ruby. Competition between Vibrio fischeri strains during initiation and maintenance of a light organ symbiosis. (in

  16. 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.

  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. Multiple Antibiotic Resistances of Vibrio Isolates from Coastal and Brackish Water Areas

    OpenAIRE

    S. Manjusha; G. B. Sarita; K. K. Elyas; Chandrasekaran, M.

    2005-01-01

    An experiment was designed to assess the occurrence of multiple antibiotic resistances in Vibrio spp. from different (brackish and marine) environments. Water samples from nine marine landing sites and two coastal inland aquaculture farms were screened for the Vibrio spp. and assessed their resistance to twenty-two different antibiotics, which are commonly encountered in the aquatic ecosystem. Tissue samples (shrimp, mussel and sepia) were tested from the sampling site wit...

  19. Identification and Characterization of a Putative Manganese Export Protein in Vibrio cholerae

    OpenAIRE

    Fisher, Carolyn R.; Wyckoff, Elizabeth E.; Peng, Eric D.; Payne, Shelley M.

    2016-01-01

    Manganese plays an important role in the cellular physiology and metabolism of bacterial species, including the human pathogen Vibrio cholerae. The intracellular level of manganese ions is controlled through coordinated regulation of the import and export of this element. We have identified a putative manganese exporter (VC0022), named mneA (manganese exporter A), which is highly conserved among Vibrio spp. An mneA mutant exhibited sensitivity to manganese but not to other cations. Under high...

  20. Oligotyping reveals community level habitat selection within the genus Vibrio

    Directory of Open Access Journals (Sweden)

    Victor Thomas Schmidt

    2014-11-01

    Full Text Available The genus Vibrio is a metabolically and genetically diverse group of facultative anaerobic Bacteria, common in aquatic environments and marine hosts. The genus contains several species of importance to human health and aquaculture, including the causative agents of human cholera and fish vibriosis. Vibrios display a wide variety of known life histories, from opportunistic pathogens to long-standing symbioses with individual host species. Studying Vibrio ecology has been challenging as individual species often display a wide range of habitat preferences, and groups of vibrios can act as socially cohesive groups. Although strong associations with salinity, temperature and other environmental variables have been established, the degree of habitat or host specificity at both the individual and community levels is unknown. Here we use oligotyping analyses in combination with a large collection of existing Vibrio 16S ribosomal RNA (rRNA gene sequence data to reveal patterns of Vibrio ecology across a wide range of environmental, host, and abiotic substrate associated habitats. Our data show that individual taxa often display a wide range of habitat preferences yet tend to be highly abundant in either substrate-associated or free-living environments. Our analyses show that Vibrio communities share considerable overlap between two distinct hosts (i.e., sponge and fish yet are distinct from the abiotic plastic substrates. Lastly, evidence for habitat specificity at the community level exists in some habitats, despite considerable stochasticity in others. In addition to providing insights into Vibrio ecology across a broad range of habitats, our study shows the utility of oligotyping as a facile, high-throughput and unbiased method for large scale analyses of publicly available sequence data repositories and suggests its wide application could greatly extend the range of possibilities to explore microbial ecology.

  1. Ocean warming and spread of pathogenic vibrios in the aquatic environment.

    Science.gov (United States)

    Vezzulli, Luigi; Colwell, Rita R; Pruzzo, Carla

    2013-05-01

    Vibrios are among the most common bacteria that inhabit surface waters throughout the world and are responsible for a number of severe infections both in humans and animals. Several reports recently showed that human Vibrio illnesses are increasing worldwide including fatal acute diarrheal diseases, such as cholera, gastroenteritis, wound infections, and septicemia. Many scientists believe this increase may be associated with global warming and rise in sea surface temperature (SST), although not enough evidence is available to support a causal link between emergence of Vibrio infections and climate warming. The effect of increased SST in promoting spread of vibrios in coastal and brackish waters is considered a causal factor explaining this trend. Field and laboratory studies carried out over the past 40 years supported this hypothesis, clearly showing temperature promotes Vibrio growth and persistence in the aquatic environment. Most recently, a long-term retrospective microbiological study carried out in the coastal waters of the southern North Sea provided the first experimental evidence for a positive and significant relationship between SST and Vibrio occurrence over a multidecadal time scale. As a future challenge, macroecological studies of the effects of ocean warming on Vibrio persistence and spread in the aquatic environment over large spatial and temporal scales would conclusively support evidence acquired to date combined with studies of the impact of global warming on epidemiologically relevant variables, such as host susceptibility and exposure. Assessing a causal link between ongoing climate change and enhanced growth and spread of vibrios and related illness is expected to improve forecast and mitigate future outbreaks associated with these pathogens.

  2. 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.

  3. Comparative Genomics of Vibrio cholerae from Haiti, Asia, and Africa

    Science.gov (United States)

    Reimer, Aleisha R.; Van Domselaar, Gary; Stroika, Steven; Walker, Matthew; Kent, Heather; Tarr, Cheryl; Talkington, Deborah; Rowe, Lori; Olsen-Rasmussen, Melissa; Frace, Michael; Sammons, Scott; Dahourou, Georges Anicet; Boncy, Jacques; Smith, Anthony M.; Mabon, Philip; Petkau, Aaron; Graham, Morag; Gilmour, Matthew W.

    2011-01-01

    Cholera was absent from the island of Hispaniola at least a century before an outbreak that began in Haiti in the fall of 2010. Pulsed-field gel electrophoresis (PFGE) analysis of clinical isolates from the Haiti outbreak and recent global travelers returning to the United States showed indistinguishable PFGE fingerprints. To better explore the genetic ancestry of the Haiti outbreak strain, we acquired 23 whole-genome Vibrio cholerae sequences: 9 isolates obtained in Haiti or the Dominican Republic, 12 PFGE pattern-matched isolates linked to Asia or Africa, and 2 nonmatched outliers from the Western Hemisphere. Phylogenies for whole-genome sequences and core genome single-nucleotide polymorphisms showed that the Haiti outbreak strain is genetically related to strains originating in India and Cameroon. However, because no identical genetic match was found among sequenced contemporary isolates, a definitive genetic origin for the outbreak in Haiti remains speculative. PMID:22099115

  4. Pre-earthquake non-epidemic Vibrio cholerae in Haiti.

    Science.gov (United States)

    Liu, Jie; Winstead-Derlega, Christopher; Houpt, Eric; Heidkamp, Rebecca; Pape, Jean; Dillingham, Rebecca

    2014-01-15

    To our knowledge, there was no record of Vibrio cholerae in Haiti until the 2010 post earthquake outbreak. This study describes the analysis of 301 stool samples from 117 infants in Port-au-Prince, Haiti, who participated in a pediatric nutrition study between July 2008 and October 2009. Nine samples were identified positive with both SYBR Green and Taqman-MGB probe based molecular assays targeting V. cholerae hlyA and toxR, respectively (Ct = 33-40), but none were O1 or O139. Our results from multiple molecular assays demonstrate the presence of non-O1/O139 V. cholerae DNA in stools collected from nine asymptomatic Haitian infants two years prior to the 2010 earthquake.

  5. Peptide nucleic acid fluorescence in-situ hybridization for identification of Vibrio spp. in aquatic products and environments.

    Science.gov (United States)

    Zhang, Xiaofeng; Li, Ke; Wu, Shan; Shuai, Jiangbing; Fang, Weihuan

    2015-08-03

    A peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) method was developed for specific detection of the Vibrio genus. In silico analysis by BLAST and ProbeCheck showed that the designed PNA probe targeting the 16S rRNAs was suitable for specific identification of Vibrio. Specificity and sensitivity of the probe Vib-16S-1 were experimentally verified by its reactivity against 18 strains of 9 Vibrio species and 14 non-Vibrio strains of 14 representative species. The PNA-FISH assay was able to identify 47 Vibrio positive samples from selectively enriched cultures of 510 samples of aquatic products and environments, comparable with the results obtained by biochemical identification and real-time PCR. We conclude that PNA-FISH can be an alternative method for rapid identification of Vibrio species in a broad spectrum of seafood or related samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Genetic diversity of culturable Vibrio in an Australian blue mussel Mytilus galloprovincialis hatchery.

    Science.gov (United States)

    Kwan, Tzu Nin; Bolch, Christopher J S

    2015-09-17

    Bacillary necrosis associated with Vibrio species is the common cause of larval and spat mortality during commercial production of Australian blue mussel Mytilus galloprovincialis. A total of 87 randomly selected Vibrio isolates from various stages of rearing in a commercial mussel hatchery were characterised using partial sequences of the ATP synthase alpha subunit gene (atpA). The sequenced isolates represented 40 unique atpA genotypes, overwhelmingly dominated (98%) by V. splendidus group genotypes, with 1 V. harveyi group genotype also detected. The V. splendidus group sequences formed 5 moderately supported clusters allied with V. splendidus/V. lentus, V. atlanticus, V. tasmaniensis, V. cyclitrophicus and V. toranzoniae. All water sources showed considerable atpA gene diversity among Vibrio isolates, with 30 to 60% of unique isolates recovered from each source. Over half (53%) of Vibrio atpA genotypes were detected only once, and only 7 genotypes were recovered from multiple sources. Comparisons of phylogenetic diversity using UniFrac analysis showed that the culturable Vibrio community from intake, header, broodstock and larval tanks were phylogenetically similar, while spat tank communities were different. Culturable Vibrio associated with spat tank seawater differed in being dominated by V. toranzoniae-affiliated genotypes. The high diversity of V. splendidus group genotypes detected in this study reinforces the dynamic nature of microbial communities associated with hatchery culture and complicates our efforts to elucidate the role of V. splendidus group bacteria in vibriosis.

  7. Vibrio bivalvicida sp. nov., a novel larval pathogen for bivalve molluscs reared in a hatchery.

    Science.gov (United States)

    Dubert, Javier; Romalde, Jesús L; Prado, Susana; Barja, Juan L

    2016-02-01

    Three isolates were obtained from cultures of carpet shell clam (Ruditapes decussatus) reared in a bivalve hatchery (Galicia, NW Spain) from different sources: healthy broodstock, moribund larvae and the seawater corresponding to the larval tank. All isolates were studied by a polyphasic approach, including a phylogenetic analysis based on concatenated sequences of the five housekeeping genes ftsZ, gyrB, pyrH, recA and rpoA. The analysis supported their inclusion in the Orientalis clade of the genus Vibrio, and they formed a tight group separated from the closest relatives: Vibrio tubiashii subsp. europaensis, Vibrio tubiashii subsp. tubiashii and Vibrio orientalis. The percentages of genomic resemblance, including average nucleotide identity, DNA-DNA hybridization and in silico genome-to-genome comparison, between the type strain and the closest relatives were below values for species delineation and confirmed the taxonomic position of the new species, which could be differentiated from the related taxa on the basis of several phenotypic and chemotaxonomic features, including FAME and MALDI-TOF-MS. The pathogenicity of the new species was demonstrated in larvae of R. decussatus, Ruditapes philippinarum, Ostrea edulis and Donax trunculus. The results demonstrated that the strains analyzed represented a novel species in the Orientalis clade of the genus Vibrio, for which the name Vibrio bivalvicida sp. nov. is proposed, with 605(T) (= CECT 8855(T)=CAIM 1904(T)) designated as the type strain. Copyright © 2015 Elsevier GmbH. All rights reserved.

  8. Prevalensi Gen tdh dan trh Vibrio parahaemolyticus pada Udang Vaname Di Wilayah Indramayu, Jawa Barat

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    Yusma Yennie

    2015-06-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui prevalensi Vibrio parahaemolyticus patogenik pada udang vaname yang berasal dari tambak tradisional dan intensif berdasarkan keberadaan gen tdh dan trh. Isolasi dan konfirmasi Vibrio parahaemolyticus mengacu pada BAM (2004, yang dilanjutkan dengan konfirmasi gen tdh dan trh Vibrio parahaemolyticus  menggunakan metode PCR.  Hasil identifikasi menunjukkan bahwa  sebanyak 16/32(50% dan 6/32 (18,8% udang dari tambak tradisional dan intensif positif Vibrio parahaemolyticus. Berdasarkan gen tdh, ditemukan Vibrio parahaemolyticus patogenik pada udang tambak tradisional dan intensif berturut-turut adalah 81% (13/16 dan 50% (3/6. Sementara itu, jika didasarkan pada gen trh, Vibrio parahaemolyticus patogenik pada udang tambak tradisional dan intensif berturut-turut adalah 15/16 (93,8% dan 4/6 (66,7%. Secara keseluruhan prevalensi udang vaname yang positif gen tdh adalah sebesar 72,2% (16/22 gen trh sebesar 86,4% (19/22 dan yang memiliki kedua gen adalah sebanyak 63,6% (14/22.

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

    Science.gov (United States)

    Shaw, Kristi S; Jacobs, John M; Crump, Byron C

    2014-01-01

    To determine if a storm event (i.e., high winds, large volumes of precipitation) could alter concentrations of Vibrio vulnificus and V. 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 (MPN) 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 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 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 4 × 10(5) MPN g(-1), V. parahaemolyticus 1 × 10(5) 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 surface water at an aquaculture facility in the Chesapeake Bay.

  10. AP4 method for two-tube nested PCR detection of AHPND isolates of Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Sirintip Dangtip

    2015-11-01

    Full Text Available Our previous work on the mechanism of virulence for the unique isolates of Vibrio parahaemolyticus that cause acute hepatopancreatic necrosis disease (VPAHPND revealed that it was mediated by a binary Pir-like toxin pair ToxA and ToxB. These toxins are located on the pVA plasmid, a plasmid carried by AHPND-causing strain of V. parahaemolyticus with a size of approximately 69 kbp. Using the coding sequences of ToxA, a one-step PCR detection method for VPAHPND was introduced in June 2014 but had the limitation that attempts to adapt it into a nested PCR protocol were unsuccessful. As a result, low levels of VPAHPND in shrimp or other samples could not be detected without first preparing an enrichment broth culture to allow bacterial growth before extraction of template DNA. Here, we describe the AP4 (abbreviation of AHPND detection version 4 method, a two-tube nested PCR method that targets the tandem genes ToxA and ToxB, including the 12 bp spacer that separates them on pVA plasmid. Testing of the method revealed that it gave 100% positive and negative predictive values for VPAHPND using a panel of 104 bacterial isolates including 51 VPAHPND isolates and 53 non-AHPND isolates, the latter including 34 isolates of V. parahaemolyticus and 19 isolates of other bacteria found in shrimp ponds, including other Vibrio species. The AP4 nested PCR method was 100 times more sensitive (100 fg total DNA template than the one-step AP3 (10 pg total DNA template method, and it could detect VPAHPND in experimentally challenged shrimp by 6 h post immersion (n = 2/3, while AP3 could not detect is until 12 h post immersion (n = 1/3. Thus, the AP4 method may be useful in detecting VPAHPND isolates in samples where target material is limited (e.g., small tissue quantity or archived DNA and enrichment cannot be employed (i.e., frozen samples or samples preserved in alcohol.

  11. Genome sequencing and analysis of a highly virulent Vibrio parahaemolyticus strain isolated from the marine environment

    Science.gov (United States)

    Parks, M. C.; Moreno, E.

    2016-02-01

    Vibrio parahaemolyticus [Vp] is a Gram-negative bacterium and a natural inhabitant of coastal marine ecosystems worldwide. Vp is also a coincidental pathogen of humans. Virulent strains are commonly identified by the presence of the thermostable direct (tdh) or tdh-related (trh) hemolysin genes. However, virulence is multifaceted and many clinical Vp isolates do not carry tdh or trh. In this study, we sequenced and assembled the draft genome of a tdh- and trh-negative environmental isolate (805) shown previously to be highly virulent in zebrafish. To investigate potential mechanisms of virulence, we compared 805 to the clinical V. parahaemolyticus type strain (RIMD2210633). Pairwise comparison revealed the presence of multiple genomic regions including an IncF conjugative pilus (1.3 Kb) and a colicin V plasmid (1.49 Kb). These features are homologous to genomic regions present in clinical V. vulnificus and V. cholerae strains. Genome comparison also revealed the presence of five toxin-antitoxin systems. Isolate 805 likely attained these new features through the lateral acquisition of mobile genomic material - a hypothesis supported by the aberrant GC content of these regions. Colicin V plasmids are a diverse group of IncF plasmids found in invasive bacterial strains. Similarly, an abundance of toxin-antitoxin systems have been linked to virulence in Gram-negative bacteria. Current efforts are focused on characterizing 142 coding features present in 805 but absent from the type strain.

  12. Genomic analysis of immune response against Vibrio cholerae hemolysin in Caenorhabditis elegans.

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    Surasri N Sahu

    Full Text Available Vibrio cholerae cytolysin (VCC is among the accessory V. cholerae virulence factors that may contribute to disease pathogenesis in humans. VCC, encoded by hlyA gene, belongs to the most common class of bacterial toxins, known as pore-forming toxins (PFTs. V. cholerae infects and kills Caenorhabditis elegans via cholerae toxin independent manner. VCC is required for the lethality, growth retardation and intestinal cell vacuolation during the infection. However, little is known about the host gene expression responses against VCC. To address this question we performed a microarray study in C. elegans exposed to V. cholerae strains with intact and deleted hlyA genes.Many of the VCC regulated genes identified, including C-type lectins, Prion-like (glutamine [Q]/asparagine [N]-rich-domain containing genes, genes regulated by insulin/IGF-1-mediated signaling (IIS pathway, were previously reported as mediators of innate immune response against other bacteria in C. elegans. Protective function of the subset of the genes up-regulated by VCC was confirmed using RNAi. By means of a machine learning algorithm called FastMEDUSA, we identified several putative VCC induced immune regulatory transcriptional factors and transcription factor binding motifs. Our results suggest that VCC is a major virulence factor, which induces a wide variety of immune response- related genes during V. cholerae infection in C. elegans.

  13. A Transposon Screen Identifies Genetic Determinants of Vibrio cholerae Resistance to High-Molecular-Weight Antibiotics.

    Science.gov (United States)

    Dörr, Tobias; Delgado, Fernanda; Umans, Benjamin D; Gerding, Matthew A; Davis, Brigid M; Waldor, Matthew K

    2016-08-01

    Gram-negative bacteria are notoriously resistant to a variety of high-molecular-weight antibiotics due to the limited permeability of their outer membrane (OM). The basis of OM barrier function and the genetic factors required for its maintenance remain incompletely understood. Here, we employed transposon insertion sequencing to identify genes required for Vibrio cholerae resistance to vancomycin and bacitracin, antibiotics that are thought to be too large to efficiently penetrate the OM. The screen yielded several genes whose protein products are predicted to participate in processes important for OM barrier functions and for biofilm formation. In addition, we identified a novel factor, designated vigA (for vancomycin inhibits growth), that has not previously been characterized or linked to outer membrane function. The vigA open reading frame (ORF) codes for an inner membrane protein, and in its absence, cells became highly sensitive to glycopeptide antibiotics (vancomycin and ramoplanin) and bacitracin but not to other large antibiotics or detergents. In contrast to wild-type (WT) cells, the vigA mutant was stained with fluorescent vancomycin. These observations suggest that VigA specifically prevents the periplasmic accumulation of certain large antibiotics without exerting a general role in the maintenance of OM integrity. We also observed marked interspecies variability in the susceptibilities of Gram-negative pathogens to glycopeptides and bacitracin. Collectively, our findings suggest that the OM barrier is not absolute but rather depends on specific OM-antibiotic interactions. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  14. Bicarbonate Increases Binding Affinity of Vibrio cholerae ToxT to Virulence Gene Promoters

    Science.gov (United States)

    Thomson, Joshua J.

    2014-01-01

    The major Vibrio cholerae virulence gene transcription activator, ToxT, is responsible for the production of the diarrhea-inducing cholera toxin (CT) and the major colonization factor, toxin coregulated pilus (TCP). In addition to the two primary virulence factors mentioned, ToxT is responsible for the activation of accessory virulence genes, such as aldA, tagA, acfA, acfD, tcpI, and tarAB. ToxT activity is negatively modulated by bile and unsaturated fatty acids found in the upper small intestine. Conversely, previous work identified another intestinal signal, bicarbonate, which enhances the ability of ToxT to activate production of CT and TCP. The work presented here further elucidates the mechanism for the enhancement of ToxT activity by bicarbonate. Bicarbonate was found to increase the activation of ToxT-dependent accessory virulence promoters in addition to those that produce CT and TCP. Bicarbonate is taken up into the V. cholerae cell, where it positively affects ToxT activity by increasing DNA binding affinity for the virulence gene promoters that ToxT activates regardless of toxbox configuration. The increase in ToxT binding affinity in the presence of bicarbonate explains the elevated level of virulence gene transcription. PMID:25182489

  15. Characterization of Vibrio Parahaemolyticus isolated from oysters and mussels in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Martha Virginia Ribeiro Rojas

    2011-08-01

    Full Text Available Vibrio parahaemolyticus is a marine bacterium, responsible for gastroenteritis in humans. Most of the clinical isolates produce thermostable direct hemolysin (TDH and TDH-related hemolysin (TRH encoded by tdh and trh genes respectively. In this study, twenty-three V. parahaemolyticus, previously isolated from oysters and mussels were analyzed by PCR using specific primers for the 16S rRNA and virulence genes (tdh, trh and tlh and for resistance to different classes of antibiotics and PFGE. Nineteen isolates were confirmed by PCR as V. parahaemolyticus. The tlh gene was present in 100% of isolates, the tdh gene was identified in two (10.5% isolates, whereas the gene trh was not detected. Each isolate was resistant to at least one of the nine antimicrobials tested. Additionally, all isolates possessed the blaTEM-116 gene. The presence of this gene in V. parahaemolyticus indicates the possibility of spreading this gene in the environment. Atypical strains of V. parahaemolyticus were also detected in this study.

  16. Synthetic hepcidin from fish: Uptake and protection against Vibrio anguillarum in sea bass (Dicentrarchus labrax).

    Science.gov (United States)

    Álvarez, Claudio Andrés; Acosta, Félix; Montero, Daniel; Guzmán, Fanny; Torres, Elisa; Vega, Belinda; Mercado, Luis

    2016-08-01

    The generation of a variety of new therapeutic agents to control and reduce the effects of pathogen in aquaculture is urgently needed. The antimicrobial peptides (AMPs) are one of the major components of the innate defenses and typically have broad-spectrum antimicrobial activity. However, absorption and distributions of exogenous AMPs for therapeutics application on farmed fish species need to be studied. Previous studies in our laboratory have shown the properties of hepcidin as an effective antimicrobial peptide produced in fish in response to LPS and iron. Therefore, we decided to investigate the antimicrobial activity of four synthetic variants of hepcidin against Vibrio anguillarum in vitro, and using the more effective peptide we demonstrated the pathogen's ability to protect against the infection in European Sea bass. Additionally the uptake of this peptide after ip injection was demonstrated, reaching its distribution organs such as intestine, head kidney, spleen and liver. The synthetic peptide did not show cytotoxic effects and significantly reduced the accumulated mortalities percentage (23.5%) compared to the European Sea bass control (72.5%) at day 21. In conclusion, synthetic hepcidin shows antimicrobial activity against V. anguillarum and the in vivo experiments suggest that synthetic hepcidin was distributed trough the different organs in the fish. Thus, synthetic hepcidin antimicrobial peptide could have high potential for therapeutic application in farmed fish species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Vibrio cholerae hemolysin is required for lethality, developmental delay, and intestinal vacuolation in Caenorhabditis elegans.

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    Hediye Nese Cinar

    Full Text Available BACKGROUND: Cholera toxin (CT and toxin-co-regulated pili (TCP are the major virulence factors of Vibrio cholerae O1 and O139 strains that contribute to the pathogenesis of disease during devastating cholera pandemics. However, CT and TCP negative V. cholerae strains are still able to cause severe diarrheal disease in humans through mechanisms that are not well understood. METHODOLOGY/PRINCIPAL FINDINGS: To determine the role of other virulence factors in V. cholerae pathogenesis, we used a CT and TCP independent infection model in the nematode Caenorhabditis elegans and identified the hemolysin A (hlyA gene as a factor responsible for animal death and developmental delay. We demonstrated a correlation between the severity of infection in the nematode and the level of hemolytic activity in the V. cholerae biotypes. At the cellular level, V. cholerae infection induces formation of vacuoles in the intestinal cells in a hlyA dependent manner, consistent with the previous in vitro observations. CONCLUSIONS/SIGNIFICANCE: Our data strongly suggest that HlyA is a virulence factor in C. elegans infection leading to lethality and developmental delay presumably through intestinal cytopathic changes.

  18. Characterization of Aeromonas trota strains that cross-react with Vibrio cholerae O139 Bengal.

    Science.gov (United States)

    Albert, M J; Ansaruzzaman, M; Shimada, T; Rahman, A; Bhuiyan, N A; Nahar, S; Qadri, F; Islam, M S

    1995-12-01

    It has previously been shown that Vibrio cholerae O139 Bengal shares antigens with V. cholerae serogroups O22 and O155. We detected six surface water isolates of Aeromonas trota that agglutinated in polyclonal antisera to V. cholerae O139 and V. cholerae O22 but not in antiserum to V. cholerae O155. On the basis of agglutinin-absorption studies, the antigenic relationship between the cross-reacting bacteria were found to be in an a,b-a,c fashion, where a is the common antigenic epitope and b and c are unique epitopes. The antigen sharing between A. trota strains and V. cholerae O139 was confirmed in immunoblot studies. However, A. trota strains did not react with two monoclonal antibodies specific for V. cholerae O139 and, consequently, tested negative in the Bengal SMART rapid diagnostic test for V. cholerae O139 which uses one of the monoclonal antibodies. A polyclonal antiserum to a cross-reacting A. trota strain cross-protected infant mice against cholera on challenge with virulent V. cholerae O139. All A. trota strains were cytotoxic for HeLa cells, positive for adherence to HEp-2 cells, and weakly invasive for HEp-2 cells; one strain was heat-stable toxin positive in the suckling mouse assay; however, all strains were negative for cholera toxin-like enterotoxin. Studies on bacteria that share somatic antigen with V. cholerae O139 may shed further light on the genesis of V. cholerae O139.

  19. Surface display of Aeromonas hydrophila GAPDH in attenuated Vibrio anguillarum to develop a Noval multivalent vector vaccine.

    Science.gov (United States)

    Zhao, Yan; Liu, Qin; Wang, Xiuhua; Zhou, Lingyun; Wang, Qiyao; Zhang, Yuanxing

    2011-10-01

    Displaying foreign antigens on the surface of attenuated or avirulent bacteria is an important strategy to develop live multivalent vector vaccines. In our previous work, several efficient surface display systems have been established based on outer membrane anchoring elements, which could successfully display heterologous proteins in attenuated Vibrio anguillarum. In this work, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from pathogenic Aeromonas hydrophila LSA34 was fused to seven display systems and introduced into attenuated V. anguillarum strain MVAV6203 (AV) to get seven GAPDH-display strains. The strain AV/pN-gapA showed the best display efficacy of GAPDH and was tested as the multivalent vaccine candidate. Further immune protection evaluation of AV/pN-gapA in turbot (Scophtalmus maximus) demonstrated that the attenuated V. anguillarum with surface-displayed GAPDH of A. hydrophila LSA34 effectively protected turbot from the infections of A. hydrophila and V. anguillarum and showed potential value for further multivalent vaccine development.

  20. Transcriptome analysis of the white body of the squid Euprymna tasmanica with emphasis on immune and hematopoietic gene discovery

    National Research Council Canada - National Science Library

    Salazar, Karla A; Joffe, Nina R; Dinguirard, Nathalie; Houde, Peter; Castillo, Maria G

    2015-01-01

    In the mutualistic relationship between the squid Euprymna tasmanica and the bioluminescent bacterium Vibrio fischeri, several host factors, including immune-related proteins, are known to interact...

  1. Transoceanic spreading of pathogenic strains of Vibrio parahaemolyticus with distinctive genetic signatures in the recA gene.

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    Narjol González-Escalona

    Full Text Available Vibrio parahaemolyticus is an important human pathogen whose transmission is associated with the consumption of contaminated seafood. Consistent multilocus sequence typing for V. parahaemolyticus has shown difficulties in the amplification of the recA gene by PCR associated with a lack of amplification or a larger PCR product than expected. In one strain (090-96, Peru, 1996, the produced PCR product was determined to be composed of two recA fragments derived from different Vibrio species. To better understand this phenomenon, we sequenced the whole genome of this strain. The hybrid recA gene was found to be the result of a fragmentation of the original lineage-specific recA gene resulting from a DNA insertion of approximately 30 kb in length. This insert had a G+C content of 38.8%, lower than that of the average G+C content of V. parahaemolyticus (45.2%, and contained 19 ORFs, including a complete recA gene. This new acquired recA gene deviated 24% in sequence from the original recA and was distantly related to recA genes from bacteria of the Vibrionaceae family. The reconstruction of the original recA gene (recA3 identified the precursor as belonging to ST189, a sequence type reported previously only in Asian countries. The identification of this singular genetic feature in strains from Asia reveals new evidence for genetic connectivity between V. parahaemolyticus populations at both sides of the Pacific Ocean that, in addition to the previously described pandemic clone, supports the existence of a recurrent transoceanic spreading of pathogenic V. parahaemolyticus with the corresponding potential risk of pandemic expansion.

  2. Survey on antimicrobial resistance patterns in Vibrio vulnificus and Vibrio cholerae non-O1/non-O139 in Germany reveals carbapenemase-producing Vibrio cholerae in coastal waters

    Directory of Open Access Journals (Sweden)

    Nadja eBier

    2015-10-01

    Full Text Available An increase in the occurrence of potentially pathogenic Vibrio species is expected for waters in Northern Europe as a consequence of global warming. In this context, a higher incidence of Vibrio infections is predicted for the future and forecasts suggest that people visiting and living at the Baltic Sea are at particular risk.This study aimed to investigate antimicrobial resistance patterns among Vibrio vulnificus and Vibrio cholerae non-O1/non-O139 isolates that could pose a public health risk. Antimicrobial susceptibility of 141 V. vulnificus and 184 V. cholerae non-O1/non-O139 strains isolated from German coastal waters (Baltic Sea and North Sea as well as from patients and retail seafood was assessed by broth microdilution and disk diffusion. Both species were susceptible to most of the agents tested (12 subclasses and no multidrug-resistance was observed. Among V. vulnificus isolates, non-susceptibility was exclusively found towards aminoglycosides. In case of V. cholerae, a noticeable proportion of strains was non-susceptible to aminopenicillins and aminoglycosides. In addition, resistance towards carbapenems, quinolones, and folate pathway inhibitors was sporadically observed. Biochemical testing indicated the production of carbapenemases with unusual substrate specificity in four environmental V. cholerae strains. Most antimicrobial agents recommended for treatment of V. vulnificus and V. cholerae non-O1/non-O139 infections were found to be effective in vitro. However, the occurrence of putative carbapenemase producing V. cholerae in German coastal waters is of concern and highlights the need for systematic monitoring of antimicrobial susceptibility in potentially pathogenic Vibrio spp. in Europe.

  3. 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.

  4. Genomic Variation and Evolution of Vibrio parahaemolyticus ST36 over the Course of a Transcontinental Epidemic Expansion.

    Science.gov (United States)

    Martinez-Urtaza, Jaime; van Aerle, Ronny; Abanto, Michel; Haendiges, Julie; Myers, Robert A; Trinanes, Joaquin; Baker-Austin, Craig; Gonzalez-Escalona, Narjol

    2017-11-14

    Vibrio parahaemolyticus is the leading cause of seafood-related infections with illnesses undergoing a geographic expansion. In this process of expansion, the most fundamental change has been the transition from infections caused by local strains to the surge of pandemic clonal types. Pandemic clone sequence type 3 (ST3) was the only example of transcontinental spreading until 2012, when ST36 was detected outside the region where it is endemic in the U.S. Pacific Northwest causing infections along the U.S. northeast coast and Spain. Here, we used genome-wide analyses to reconstruct the evolutionary history of the V. parahaemolyticus ST36 clone over the course of its geographic expansion during the previous 25 years. The origin of this lineage was estimated to be in ~1985. By 1995, a new variant emerged in the region and quickly replaced the old clone, which has not been detected since 2000. The new Pacific Northwest (PNW) lineage was responsible for the first cases associated with this clone outside the Pacific Northwest region. After several introductions into the northeast coast, the new PNW clone differentiated into a highly dynamic group that continues to cause illness on the northeast coast of the United States. Surprisingly, the strains detected in Europe in 2012 diverged from this ancestral group around 2000 and have conserved genetic features present only in the old PNW lineage. Recombination was identified as the major driver of diversification, with some preliminary observations suggesting a trend toward a more specialized lifestyle, which may represent a critical element in the expansion of epidemics under scenarios of coastal warming.IMPORTANCEVibrio parahaemolyticus and Vibrio cholerae represent the only two instances of pandemic expansions of human pathogens originating in the marine environment. However, while the current pandemic of V. cholerae emerged more than 50 years ago, the global expansion of V. parahaemolyticus is a recent phenomenon

  5. Effectiveness of icing as a postharvest treatment for control of Vibrio vulnificus and Vibrio parahaemolyticus in the eastern oyster (Crassostrea virginica).

    Science.gov (United States)

    Melody, Kevin; Senevirathne, Reshani; Janes, Marlene; Jaykus, Lee Ann; Supan, John

    2008-07-01

    The focus of this research was to investigate the efficacy of icing as a postharvest treatment for reduction of the levels of Vibrio vulnificus and Vibrio parahaemolyticus in commercial quantities of shellstock oysters. The experiments were conducted in June and August of 2006 and consisted of the following treatments: (i) on-board icing immediately after harvest; (ii) dockside icing approximately 1 to 2 h prior to shipment; and (iii) no icing (control). Changes in the levels of pathogenic Vibrio spp. during wholesale and retail handling for 2 weeks postharvest were also monitored. On-board icing achieved temperature reductions in all sacks in accordance with the National Shellfish Sanitation Program standard, but dockside icing did not meet this standard. Based on one-way analysis of variance, the only statistically significant relationship between Vibrio levels and treatment occurred for samples harvested in August; in this case, the levels of V. vulnificus in the noniced oysters were significantly higher (P iced on-board. When analyzing counts over the 14-day storage period, using factorial analysis, there were statistically significant differences in V. vulnificus and V. parahaemolyticus levels by sample date and/or treatment (P iced) oysters had significantly higher gaping (approximately 20%) after 1 week in cold storage than did noniced oysters (approximately 10%) and gaping increased significantly by day 14 of commercial storage. On-board and dockside icing did not predictably reduce the levels of V. vulnificus or V. parahaemolyticus in oysters, and icing negatively impacted oyster survival during subsequent cold storage.

  6. 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

  7. Toxicity of individual pharmaceuticals and their mixtures to Aliivibrio fischeri: Experimental results for single compounds and considerations of their mechanisms of action and potential acute effects on aquatic organisms.

    Science.gov (United States)

    Di Nica, Valeria; Villa, Sara; Finizio, Antonio

    2017-03-01

    In the first part of a broader study on the effects of individual and multicomponent mixtures of pharmaceutical active compounds, the authors used the Microtox(®) test system to analyze in detail the effects of 10 widely used human and veterinary pharmaceutical active compounds toward the bioluminescent bacterium Aliivibrio fischeri. The experimental results indicated moderate toxicity for the majority of the tested compounds. Comparison between experimental 50% inhibitory concentrations and those predicted from the quantitative structure-activity relationship models indicated that most of the tested pharmaceutical active compounds behave as polar narcotic compounds toward A. fischeri (only the antibiotic chlortetracycline seemed to have a specific mechanism of action). A comparison between the experimental results and a collection of acute toxicity data on other nontarget organisms indicated that in general A. fischeri has a comparable sensitivity to other aquatic species. However, according to the Globally Harmonized System of Classification and Labelling of Chemicals, the majority of the investigated chemicals can be classified as harmful or nontoxic for aquatic ecosystems. Finally, based on comparisons among the 95th percentile of measured environmental concentrations found in European Union water bodies and acute toxicity data on various aquatic organisms, no risk to aquatic life exists when the tested pharmaceutical active compounds are assessed as individual chemicals. Environ Toxicol Chem 2017;36:807-814. © 2016 SETAC. © 2016 SETAC.

  8. 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

  9. 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

  10. 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

  11. Novel β-N-acetylglucosaminidases from Vibrio harveyi 650: Cloning, expression, enzymatic properties, and subsite identification

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    Mizuhara Mamiko

    2010-09-01

    Full Text Available Abstract Background Since chitin is a highly abundant natural biopolymer, many attempts have been made to convert this insoluble polysaccharide into commercially valuable products using chitinases and β-N-acetylglucosaminidases (GlcNAcases. We have previously reported the structure and function of chitinase A from Vibrio harveyi 650. This study t reports the identification of two GlcNAcases from the same organism and their detailed functional characterization. Results The genes encoding two new members of family-20 GlcNAcases were isolated from the genome of V. harveyi 650, cloned and expressed at a high level in E. coli. VhNag1 has a molecular mass of 89 kDa and an optimum pH of 7.5, whereas VhNag2 has a molecular mass of 73 kDa and an optimum pH of 7.0. The recombinant GlcNAcases were found to hydrolyze all the natural substrates, VhNag2 being ten-fold more active than VhNag1. Product analysis by TLC and quantitative HPLC suggested that VhNag2 degraded chitooligosaccharides in a sequential manner, its highest activity being with chitotetraose. Kinetic modeling of the enzymic reaction revealed that binding at subsites (-2 and (+4 had unfavorable (positive binding free energy changes and that the binding pocket of VhNag2 contains four GlcNAc binding subsites, designated (-1,(+1,(+2, and (+3. Conclusions Two novel GlcNAcases were identified as exolytic enzymes that degraded chitin oligosaccharides, releasing GlcNAc as the end product. In living cells, these intracellular enzymes may work after endolytic chitinases to complete chitin degradation. The availability of the two GlcNAcases, together with the previously-reported chitinase A from the same organism, suggests that a systematic development of the chitin-degrading enzymes may provide a valuable tool in commercial chitin bioconversion.

  12. 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.

  13. Isolation of Vibrio parahaemolyticus from fecal specimens on mannitol salt agar.

    Science.gov (United States)

    Carruthers, M M; Kabat, W J

    1976-08-01

    Unless laboratories use an inhibitory medium, Vibrio parahaemolyticus will be unrecognizable in fecal specimens. The use of a medium exclusively for vibrio isolation, such as thiosulfate-citrate-bile salts-sucrose agar (TCBS), however, may not be considered economically justified in the United States. The isolation and recognition of V. parahaemolyticus is reported on mannitol salt agar (MS), a medium which is used for fecal specimens here. Eight Kanagawa-positive and two of three Kanagawa-negative strains of V. parahaemolyticus grew as well on MS as on TCBS and better than on a representative enteric medium, Hektoen enteric agar (HE). Twenty-two fecal specimens from 16 noninfected individuals were inoculated with known quantities of V. parahaemolyticus, and recovery of these vibrios was assessed on TCBS, MS, and HE. Recovery of vibrios from MS and TCBS was similar when inoculum size was 10(3) colony-forming units/ml or greater. Recovery of vibrios from mixed culture was distinctly lower on HE. The colonial morphology of V. parahaemolyticus and several other bacteria on MS is illustrated.

  14. Essential oils of Nigella sativa protects Artemia from the pathogenic effect of Vibrio parahaemolyticus Dahv2.

    Science.gov (United States)

    Manju, Sivalingam; Malaikozhundan, Balasubramanian; Withyachumnarnkul, Boonsirm; Vaseeharan, Baskaralingam

    2016-05-01

    The anti-Vibrio activity of essential oils (EOs) of nine medicinal plants was tested against 28 Vibrio spp. isolated from diseased Fenneropenaeus indicus. EO of Nigella sativa exhibited anti-Vibrio activity against all Vibrio spp. and greater inhibition was noted for the isolate V2 which was identified as Vibrio parahaemolyticus Dahv2. Further, EO of N. sativa effectively inhibited V. parahaemolyticus Dahv2 with an inhibition zone of 23.9mm at 101.2μgml(-1). Moreover, EO of N. sativa revealed anti-biofilm activity at 101.2μgml(-1) against V. parahaemolyticus Dahv2 and inhibited the growth of V. parahaemolyticus Dahv2 at 100μgml(-1).In vivo experimental infection studies showed that the survival of Artemia spp. infected with V. parahaemolyticus Dahv2 at 1×10(3)cfuml(-1) was only 40%. However, the survival of Artemia spp. was significantly increased after challenge with 100μgml(-1) of EO of N. sativa. EO of N. sativa showed higher anti-oxidant potential and total phenol content than other EOs tested. The anti-oxidant activity of EO of N. sativa was highly correlated to their total phenolic contents (r=0.836, PArtemia spp. after experimental infection of V. parahaemolyticus Dahv2. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. 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.

  16. Effect of Climate Change on the Concentration and Associated Risks of Vibrio Spp. in Dutch Recreational Waters

    NARCIS (Netherlands)

    Sterk, Ankie; Schets, Franciska M; de Roda Husman, Ana Maria; de Nijs, Ton; Schijven, Jack F; de Roda Husman, Ana Maria

    2015-01-01

    Currently, the number of reported cases of recreational- water-related Vibrio illness in the Netherlands is low. However, a notable higher incidence of Vibrio infections has been observed in warm summers. In the future, such warm summers are expected to occur more often, resulting in enhanced water

  17. Effect of Climate Change on the Concentration and Associated Risks of Vibrio Spp. in Dutch Recreational Waters.

    Science.gov (United States)

    Sterk, Ankie; Schets, Franciska M; de Roda Husman, Ana Maria; de Nijs, Ton; Schijven, Jack F

    2015-09-01

    Currently, the number of reported cases of recreational- water-related Vibrio illness in the Netherlands is low. However, a notable higher incidence of Vibrio infections has been observed in warm summers. In the future, such warm summers are expected to occur more often, resulting in enhanced water temperatures favoring Vibrio growth. Quantitative information on the increase in concentration of Vibrio spp. in recreational water under climate change scenarios is lacking. In this study, data on occurrence of Vibrio spp. at six different bathing sites in the Netherlands (2009-2012) were used to derive an empirical formula to predict the Vibrio concentration as a function of temperature, salinity, and pH. This formula was used to predict the effects of increased temperatures in climate change scenarios on Vibrio concentrations. For Vibrio parahaemolyticus, changes in illness risks associated with the changed concentrations were calculated as well. For an average temperature increase of 3.7 °C, these illness risks were calculated to be two to three times higher than in the current situation. Current illness risks were, varying per location, on average between 10(-4) and 10(-2) per person for an entire summer. In situations where water temperatures reached maximum values, illness risks are estimated to be up to 10(-2) and 10(-1) . If such extreme situations occur more often during future summers, increased numbers of ill bathers or bathing-water-related illness outbreaks may be expected. © 2015 Society for Risk Analysis.

  18. Genetic components of stringent response in Vibrio cholerae

    Science.gov (United States)

    Pal, Ritesh Ranjan; Das, Bhabatosh; Dasgupta, Shreya; Bhadra, Rupak K.

    2011-01-01

    Nutritional stress elicits stringent response in bacteria involving modulation of expression of several genes. This is mainly triggered by the intracellular accumulation of two small molecules, namely, guanosine 3’-diphosphate 5’-triphosphate and guanosine 3’,5’-bis(diphosphate), collectively called (p)ppGpp. Like in other Gram-negative bacteria, the cellular level of (p)ppGpp is maintained in Vibrio cholerae, the causative bacterial pathogen of the disease cholera, by the products of two genes relA and spoT. However, apart from relA and spoT, a novel gene relV has recently been identified in V. cholerae, the product of which has been shown to be involved in (p)ppGpp synthesis under glucose or fatty acid starvation in a ΔrelA ΔspoT mutant background. Furthermore, the GTP binding essential protein CgtA and a non-DNA binding transcription factor DksA also seem to play several important roles in modulating stringent response and regulation of other genes in this pathogen. The present review briefly discusses about the role of all these genes mainly in the management of stringent response in V. cholerae. PMID:21415497

  19. The pathogenesis, detection and prevention of Vibrio parahaemolyticus

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    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.

  20. The association between non-biting midges and Vibrio cholerae.

    Science.gov (United States)

    Broza, Meir; Gancz, Hanan; Kashi, Yechezkel

    2008-12-01

    Vibrio cholerae is a natural inhabitant of aquatic ecosystems, yet its interactions within this habitat are poorly understood. Here we describe the current knowledge on the interaction of V. cholerae with one group of co-inhabitants, the chironomids. Chironomids, non-biting midges (Chironomidae, Diptera), are an abundant macroinvertebrate group encountered in freshwater aquatic habitats. As holometabolous insects, chironomids start life when their larvae hatch from eggs laid at the water/air interface; through various feeding strategies, the larvae grow and pupate to become short-lived, non-feeding, adult flying insects. The discovery of the connection between V. cholerae and chironomids was accidental. While working with Chironomus transavaalensis, we observed the disintegration of its egg masses and searched for a possible microbial agent. We identified V. cholerae as the primary cause of this phenomenon. Haemagglutinin/protease, a secreted extracellular enzyme, degraded the gelatinous matrix surrounding the eggs, enabling bacterial growth. Observation of chironomids in relation to V. cholerae continuously for 7 years in various types of water bodies in Israel, India, and Africa revealed that environmental V. cholerae adhere to egg-mass surfaces of various Chironomini ('bloodworms'). The flying adults' potential to serve as mechanical vectors of V. cholerae from one water body to another was established. This, in turn, suggested that these insects play a role in the ecology of V. cholerae and possibly take part in the dissemination of the pathogenic serogroups during, and especially between, epidemics.

  1. Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

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    Carla eLutz

    2013-12-01

    Full Text Available It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium could be detected in areas where it had not been isolated from before, indicating a much broader, global distribution of this bacterium rather than specifically within regions where cholera is endemic. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of the bacterium in the sometimes hostile environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists.

  2. Vibrio cholerae: A historical perspective and current trend

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    Mary Oyenike Oladokun

    2016-11-01

    Full Text Available Vibrio cholerae (V. cholerae is a Gram-negative, curved, rod-shaped bacteria with two of its strains V. cholerae O1 and V. cholerae O139 known to cause cholera, a deadly diarrheal disease that has repeatedly plagued the world in pandemics since 1817 and still remains a public health problem globally till today. The pathogens’ persistence in aquatic milieux during inter-epidemic periods is facilitated by the production of a biofilm, thus evolving from being an infection of oral-fecal transmission to a more composite ecological framework of a communicable disease. The outbreaks of cholera spread rapidly in various intensities within and among countries and even continents and the World Health Organization estimates that 3–5 million cases outbreak and over 200 000 die yearly from cholera. Also, the impact of a cholera epidemic is not limited to its high morbidity and mortality rates alone, but also the grievous impact on the economy of the countries experiencing the outbreaks. In this review, we carried out an overview of V. cholerae including its isolation and detection, genetics as well as a comparison of the toxigenic and non-toxigenic determinants in the human host and the host defences. Furthermore, the history of global pandemics, cost implications, conflict and ecological methodologies of cholera prevention and control. The management of disease and antibiotic resistance in V. cholerae are also highlighted.

  3. The repertoire of glycosphingolipids recognized by Vibrio cholerae.

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    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.

  4. Characterization of Toxigenic Vibrio cholerae from Haiti, 2010–2011

    Science.gov (United States)

    Bopp, Cheryl; Tarr, Cheryl; Parsons, Michele B.; Dahourou, Georges; Freeman, Molly; Joyce, Kevin; Turnsek, Maryann; Garrett, Nancy; Humphrys, Michael; Gomez, Gerardo; Stroika, Steven; Boncy, Jacques; Ochieng, Benjamin; Oundo, Joseph; Klena, John; Smith, Anthony; Keddy, Karen; Gerner-Smidt, Peter

    2011-01-01

    In October 2010, the US Centers for Disease Control and Prevention received reports of cases of severe watery diarrhea in Haiti. The cause was confirmed to be toxigenic Vibrio cholerae, serogroup O1, serotype Ogawa, biotype El Tor. We characterized 122 isolates from Haiti and compared them with isolates from other countries. Antimicrobial drug susceptibility was tested by disk diffusion and broth microdilution. Analyses included identification of rstR and VC2346 genes, sequencing of ctxAB and tcpA genes, and pulsed-field gel electrophoresis with SfiI and NotI enzymes. All isolates were susceptible to doxycycline and azithromycin. One pulsed-field gel electrophoresis pattern predominated, and ctxB sequence of all isolates matched the B-7 allele. We identified the tcpETCIRS allele, which is also present in Bangladesh strain CIRS 101. These data show that the isolates from Haiti are clonally and genetically similar to isolates originating in Africa and southern Asia and that ctxB-7 and tcpETCIRS alleles are undergoing global dissemination. PMID:22099116

  5. Immune response of shrimp (Penaeus monodon against Vibrios furnissii pathogen

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    Kumaran Subramanian

    2014-04-01

    Full Text Available Objective: To analyse experimental infection and immune system of shrimp (Penaeus monodon against Vibrios furnissii (V. furnissii. Methods: Experimental animals were collected and acclimatized by maintaining specific temperature, pH and salinity to avoid mortality. Shrimps were experimentally infected with V. furnissii and their immune responses were monitored. After the infection all the shrimps were monitored for any symptoms, death rate in 0, 12, 24, 36, 48 h. Then haemolymph were collected and tetrahydrocannabinol, phenol oxidase, nitroblue tetrazolium and lysozyme were monitored in every 12 h at the interval of 48 h. Results: Shrimps infected by live V. furnissii had showed gradual increase in tetrahydrocannabinol, phenol oxidase activity, nitro-blue-tetrazolium and lysozyme activity comparing with the killed and control. Conclusions: The live V. furnissii had showed infection in the shrimp immune system. The live V. furnissii shows infection in experimental shrimps comparing with killed V. furnissii. So the V. furnissii in nature cause the infection in shrimp Penaeus monodon immune system. This report could be applied to control of the infection in shrimp hatchery.

  6. Molecular characterization of a highly-active thermophilic β-glucosidase from Neosartorya fischeri P1 and its application in the hydrolysis of soybean isoflavone glycosides.

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    Xinzhuo Yang

    Full Text Available Isoflavone occurs abundantly in leguminous seeds in the form of glycoside and aglycone. However, isoflavone glycoside has anti-nutritional effect and only the free type is beneficial to human health. In the present study we identified a β-glucosidase from thermophilic Neosartorya fischeri P1, termed NfBGL1, capable of efficiently converting isoflavone glycosides into free isoflavones. The gene, belonging to glycoside hydrolase family 3, was successfully overexpressed in Pichia pastoris at high cell density in a 3.7-l fermentor. Purified recombinant NfBGL1 had higher specific activity (2189 ± 1.7 U/mg and temperature optimum (80 °C than other fungal counterparts when using p-nitrophenyl β-D-glucopyranoside as the substrate. It retained stable at temperatures up to 70 °C and over a broad pH range of 3.0-10.0. NfBGL1 had broad substrate specificity including glucosidase, cellobiase, xylanase and glucanase activities, and displayed preference for hydrolysis of β-1,2 glycosidic bond rather than β-1,3, β-1,4, β-1,6 bonds. The enzyme showed high bioconversion ability for major soybean isoflavone glycosides (daidin, gensitin and glycitin into free forms. These properties make NfBGL1 potential for the wide use in the food, feed, pharmacy and biofuel industries.

  7. First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838 (Hymenoptera, Vespidae, Masarinae in Cyprus In memory of Friedrich W. Gess

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    Volker Mauss

    2014-09-01

    Full Text Available Celonites fischeri was recorded from ten localities in various open, disturbed habitats in North-West Cyprus. The species is probably narrowly oligolectic exploiting exclusively flowers of Echium (Boraginaceae as the sole pollen and nectar source. Females perform a pollen collecting strategy hitherto unknown in pollen wasps; they ingest pollen from fresh anthers of Echium flowers that have just started to open by forcing their head into the only slightly opened corolla. Males patrol along Echium plants in search for females. Mating was mainly observed at Echium flowers but also occurred in the area of a male sleeping aggregation. The aerial nest, consisting of 2–5 earthen cells sometimes covered with an additional thin layer of earth, is attached to stones or plants. Nest building and soil collection behaviour are described and an ethogram of a nesting female observed during three consecutive days is given. Males form sleeping aggregations at particular sites that are continuously used over at least eleven consecutive nights, even though the size of the male groups may vary from day to day. During sleeping, the males characteristically curl their bodies around withered stems.

  8. Vibrio alginolyticus Associated Chronic Myringitis Acquired in Mediterranean Waters of Turkey

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    Burak Ekrem Citil

    2015-01-01

    Full Text Available Vibrio alginolyticus was originally classified as biotype 2 of Vibrio parahaemolyticus. Most clinical isolates are recovered from superficial wounds or the external ear infections. V. alginolyticus is acknowledged to be nearly nonpathogenic in humans. The reason for presence of V. alginolyticus’s virulence is uncertain. We describe a chronic myringitis case in a 47-year-old female due to V. alginolyticus. According to her anamnesis, it was detected that she had sea bathing history in Mugla Coast in Turkey. Pure isolation of V. alginolyticus was obtained from external auditory canal’s culture. Investigation and antimicrobial susceptibility of the isolate were performed by the automatized BD Phoenix system and Kirby-Bauer disk diffusion method, respectively. The bacteria were sensitive to all antibiotics. This case was presented to pay attention to Vibrio alginolyticus infections.

  9. Evaluation of Cholera Toxin Expression in Different Populations of Vibrio cholera

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    Sedigheh Ebrahimi Kasgari

    2015-02-01

    Full Text Available Background: Cholera is one of the most diseases of human. Cholera toxin is the most important pathogenic factor in humans that causes diarrhea. The cholera toxin is produced by V. cholerae and CTXфPhage. Objectives: In this study, we have investigated the production cholera toxin with different density of Vibrio cholerae. Materials and Methods: With this propose we inoculated classical strain O1 of Vibrio cholerae ATCC 14035 and Vibrio cholerae O1biovar El Tor N16961 into the AKI medium. Then, the total mRNA was determined by standard procedure which was converted into total cDNA. Results: Cholra toxin production was determined by qPCR and maximum production of cholera toxin was at 1010 cfu/mL. Conclusions: In conclusion, production of cholera toxin was minimized almost up to zero at 1010.5 cfu/mL; which could be due to presence of high level concentration of autoinducer.

  10. Prevalence of Vibrio parahaemolyticus, and Vibrio vulnificus in blue crabs (Callinectes sapidus), seawater and sediments of the Maryland Coastal Bays.

    Science.gov (United States)

    Rodgers, C; Parveen, S; Chigbu, P; Jacobs, J; Rhodes, M; Harter-Dennis, J

    2014-10-01

    To determine the prevalence of total and pathogenic Vibrio parahaemolyticus (Vp) and V. vulnificus (Vv) in blue crabs, water and sediment from the Maryland Coastal Bays (MCBs), USA. Crab, haemolymph, sediment and seawater samples were collected monthly from four sites in MCBs from February 2012 through October 2012 with environmental parameters recorded. The most-probable-number (MPN) methodology was used to enumerate Vp and Vv with presumptive colonies and the presence of virulence markers confirmed using polymerase chain reaction (PCR). Results indicate that blue crabs contained both Vp and Vv at densities (7·28 and 5·43 log MPN g(-1) , respectively) higher than those reported for bivalves. In addition, markers for clinically relevant strains of both species were detected in over 30% of samples. Haemolymph, sediment and seawater samples were also routinely positive for both species and clinically relevant strains, but generally at lower densities than found in crabs (4·27, 3·28, and 2·39 log MPN g(-1) per ml(-1) Vp, and 4·28, 2·49 and 2·38 log MPN g(-1) per ml(-1) Vv). Blue crabs concentrate Vp and Vv at levels greater than found in water or sediment. While changes in abundance associated with temperature are apparent, there is little evidence to support differences among sampling locations. These results highlight the potential for blue crab related vibriosis and the importance of proper handling, cooking and care of this popular seafood before consumption. © 2014 The Society for Applied Microbiology.

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

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    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.

  12. 77 FR 70176 - Previous Participation Certification

    Science.gov (United States)

    2012-11-23

    ... URBAN DEVELOPMENT Previous Participation Certification AGENCY: Office of the Chief Information Officer... digital submission of all data and certifications is available via HUD's secure Internet systems. However...: Previous Participation Certification. OMB Approval Number: 2502-0118. Form Numbers: HUD-2530 . Description...

  13. Chitinase determinants of Vibrio vulnificus: gene cloning and applications of a chitinase probe.

    OpenAIRE

    Wortman, A T; Somerville, C C; Colwell, R R

    1986-01-01

    To initiate study of the genetic control of chitinolytic activity in vibrios, the chitobiase gene was isolated by cloning chromosomal DNA prepared from Vibrio vulnificus. Chimeric plasmids were constructed from Sau3A I partial digests of chromosomal DNA by ligating 5 to 15-kilobase fragments into the BamHI site, i.e., in the Tcr gene, of pBR322 (Amr Tcr). The resulting plasmids were transformed into Escherichia coli DH1. Chitobiase activity of the insert-bearing clones was detected by using a...

  14. 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

    We present the first case of intracerebral abscess after blood-borne infection with non-toxigenic Vibrio cholerae (non-01). The patient was a 66 year-old woman who was infected after swimming in Danish seawater during an unusually hot summer. She had predisposing haemochromatosis and a skin lesion...... 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....

  15. Comparative Genome Analyses of Vibrio anguillarum Strains Reveal a Link with Pathogenicity Traits

    DEFF Research Database (Denmark)

    Castillo, Daniel; D'Alvise, Paul; Xu, Ruiqi

    2017-01-01

    Vibrio anguillarum is a marine bacterium that can cause vibriosis in many fish and shellfish species, leading to high mortalities and economic losses in aquaculture. Although putative virulence factors have been identified, the mechanism of pathogenesis of V. anguillarum is not fully understood...... a link between genotype and virulence characteristics of Vibrio anguillarum, which can be used to unravel the molecular evolution of V. anguillarum and can also be important from survey and diagnostic perspectives. Importance : Comparative genome analysis of strains of a pathogenic bacterial species can...

  16. Characterization of a Vibrio cholerae phage isolated from the coastal water of Peru.

    Science.gov (United States)

    Talledo, Miguel; Rivera, Irma N G; Lipp, Erin K; Neale, Angela; Karaolis, David; Huq, Anwar; Colwell, Rita R

    2003-05-01

    A Vibrio cholerae bacteriophage, family Myoviridae, was isolated from seawater collected from the coastal water of Lima, Peru. Genome size was estimated to be 29 kbp. The temperate phage was specific to V. cholerae and infected 12/13 V. cholerae O1 strains and half of the four non-O1/non-O139 strains tested in this study. Vibrio cholerae O139 strains were resistant to infection and highest infection rates were obtained in low nutrient media amended with NaCl or prepared using seawater as diluent.

  17. Vibrio cholerae Serogroup O139: Isolation from Cholera Patients and Asymptomatic Household Family Members in Bangladesh between 2013 and 2014.

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    Fahima Chowdhury

    2015-11-01

    Full Text Available Cholera is endemic in Bangladesh, with outbreaks reported annually. Currently, the majority of epidemic cholera reported globally is El Tor biotype Vibrio cholerae isolates of the serogroup O1. However, in Bangladesh, outbreaks attributed to V. cholerae serogroup O139 isolates, which fall within the same phylogenetic lineage as the O1 serogroup isolates, were seen between 1992 and 1993 and in 2002 to 2005. Since then, V. cholerae serogroup O139 has only been sporadically isolated in Bangladesh and is now rarely isolated elsewhere.Here, we present case histories of four cholera patients infected with V. cholerae serogroup O139 in 2013 and 2014 in Bangladesh. We comprehensively typed these isolates using conventional approaches, as well as by whole genome sequencing. Phenotypic typing and PCR confirmed all four isolates belonging to the O139 serogroup.Whole genome sequencing revealed that three of the isolates were phylogenetically closely related to previously sequenced El Tor biotype, pandemic 7, toxigenic V. cholerae O139 isolates originating from Bangladesh and elsewhere. The fourth isolate was a non-toxigenic V. cholerae that, by conventional approaches, typed as O139 serogroup but was genetically divergent from previously sequenced pandemic 7 V. cholerae lineages belonging to the O139 or O1 serogroups.These results suggest that previously observed lineages of V. cholerae O139 persist in Bangladesh and can cause clinical disease and that a novel disease-causing non-toxigenic O139 isolate also occurs.

  18. Molecular and Genomic Characterization of Vibrio mimicus Isolated from a Frozen Shrimp Processing Facility in Mexico.

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    Iliana Guardiola-Avila

    Full Text Available Vibrio mimicus is a gram-negative bacterium responsible for diseases in humans. Three strains of V. mimicus identified as V. mimicus 87, V. mimicus 92 and V. mimicus 93 were isolated from a shrimp processing facility in Guaymas, Sonora, Mexico. The strains were analyzed using several molecular techniques and according to the cluster analysis they were different, their similarities ranged between 51.3% and 71.6%. ERIC-PCR and RAPD (vmh390R were the most discriminatory molecular techniques for the differentiation of these strains. The complete genomes of two strains (V. mimicus 87, renamed as CAIM 1882, and V. mimicus 92, renamed as CAIM 1883 were sequenced. The sizes of the genomes were 3.9 Mb in both strains, with 2.8 Mb in ChI and 1.1 Mb in ChII. A 12.7% difference was found in the proteome content (BLAST matrix. Several virulence genes were detected (e.g. capsular polysaccharide, an accessory colonization factor and genes involved in quorum-sensing which were classified in 16 categories. Variations in the gene content between these genomes were observed, mainly in proteins and virulence genes (e.g., hemagglutinin, mobile elements and membrane proteins. According to these results, both strains were different, even when they came from the same source, giving an insight of the diversity of V. mimicus. The identification of various virulence genes, including a not previously reported V. mimicus gene (acfD in ChI in all sequenced strains, supports the pathogenic potential of this species. Further analysis will help to fully understand their potential virulence, environmental impact and evolution.

  19. Regulatory cross-talk links Vibrio cholerae chromosome II replication and segregation.

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    Yoshiharu Yamaichi

    2011-07-01

    Full Text Available There is little knowledge of factors and mechanisms for coordinating bacterial chromosome replication and segregation. Previous studies have revealed that genes (and their products that surround the origin of replication (oriCII of Vibrio cholerae chromosome II (chrII are critical for controlling the replication and segregation of this chromosome. rctB, which flanks one side of oriCII, encodes a protein that initiates chrII replication; rctA, which flanks the other side of oriCII, inhibits rctB activity. The chrII parAB2 operon, which is essential for chrII partitioning, is located immediately downstream of rctA. Here, we explored how rctA exerts negative control over chrII replication. Our observations suggest that RctB has at least two DNA binding domains--one for binding to oriCII and initiating replication and the other for binding to rctA and thereby inhibiting RctB's ability to initiate replication. Notably, the inhibitory effect of rctA could be alleviated by binding of ParB2 to a centromere-like parS site within rctA. Furthermore, by binding to rctA, ParB2 and RctB inversely regulate expression of the parAB2 genes. Together, our findings suggest that fluctuations in binding of the partitioning protein ParB2 and the chrII initiator RctB to rctA underlie a regulatory network controlling both oriCII firing and the production of the essential chrII partitioning proteins. Thus, by binding both RctB and ParB2, rctA serves as a nexus for regulatory cross-talk coordinating chrII replication and segregation.

  20. Insight Into the Origin and Evolution of the Vibrio parahaemolyticus Pandemic Strain

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    Romilio T. Espejo

    2017-07-01

    Full Text Available A strain of Vibrio parahaemolyticus that emerged in 1995 caused the first known pandemic involving this species. This strain comprises clonal autochthonous ocean-dwelling bacteria whose evolution has occurred in the ocean environment. The low sequence diversity in this population enabled the discovery of information on its origin and evolution that has been hidden in bacterial clones that have evolved over a long period. Multilocus sequencing and microarray analysis, together with phylogenetic analysis, of pandemic and pre-pandemic isolates has suggested that the founder clone was an O3:K6 non-pathogenic strain that initially acquired a toxRS/new region and subsequently acquired at least seven novel genomic islands. Sequencing and comparison of whole genomes later confirmed these early observations, and it confirmed that most of the genetic changes occurred via gene conversion involving horizontally transmitted DNA. The highly clonal population rapidly diversified, especially in terms of antigenicity, and 27 serotypes have already been reported. Comparisons of the core genomes derived from the founder clone indicate that there are only a few hundred single-nucleotide variations between isolates. However, when the whole genome is considered (the core plus non-core genome and from any clonal frame, the amount of DNA with a different clonal frame can reach up to 4.2% and the number of single-nucleotide variations can reach several hundred thousand. Altogether, these and previous observations based on multilocus sequence typing, microarray analysis, and whole-genome sequencing indicate the large contribution made by DNA with different clonal genealogy to genome diversification. The evidence also indicates that horizontal gene transfer (HGT caused the emergence of new pathogens. Furthermore, the extent of HGT seems to depend on the vicissitudes of the life of each bacterium, as exemplified by differences in thousands of base pairs acquired by HGT

  1. Selective and Efficient Elimination of Vibrio cholerae with a Chemical Modulator that Targets Glucose Metabolism

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    Young Taek Oh

    2016-11-01

    Full Text Available Vibrio cholerae, a Gram-negative bacterium, is the causative agent of pandemic cholera. Previous studies have shown that the survival of the seventh pandemic El Tor biotype V. cholerae strain N16961 requires production of acetoin in a glucose-rich environment. The production of acetoin, a neutral fermentation end-product, allows V. cholerae to metabolize glucose without a pH drop, which is mediated by the production of organic acid. This finding suggests that inhibition of acetoin fermentation can result in V. cholerae elimination by causing a pH imbalance under glucose-rich conditions. Here, we developed a simple high-throughput screening method and identified an inducer of medium acidification (iMAC. Of 8,364 compounds screened, we identified one chemical, 5-(4-chloro-2-nitrobenzoyl-6-hydroxy-1,3-dimethylpyrimidine-2,4(1H,3H-dione, that successfully killed glucose-metabolizing N16961 by inducing acidic stress. When N16961 was grown with abundant glucose in the presence of iMAC, acetoin production was completely suppressed and concomitant accumulation of lactate and acetate was observed. Using a beta-galactosidase activity assay with a single-copy palsD::lacZ reporter fusion, we show that that iMAC likely inhibits acetoin production at the transcriptional level. Thin-layer chromatography revealed that iMAC causes a significantly reduced accumulation of intracellular (pppGpp, a bacterial stringent response alarmone known to positively regulate acetoin production. In vivo bacterial colonization and fluid accumulation were also markedly decreased after iMAC treatment. Finally, we demonstrate iMAC-induced bacterial killing for 22 different V. cholerae strains belonging to diverse serotypes. Together, our results suggest that iMAC, acting as a metabolic modulator, has strong potential as a novel antibacterial agent for treatment against cholera.

  2. Comparative genomics of pathogenic lineages of Vibrio nigripulchritudo identifies virulence-associated traits.

    Science.gov (United States)

    Goudenège, David; Labreuche, Yannick; Krin, Evelyne; Ansquer, Dominique; Mangenot, Sophie; Calteau, Alexandra; Médigue, Claudine; Mazel, Didier; Polz, Martin F; Le Roux, Frédérique

    2013-10-01

    Vibrio nigripulchritudo is an emerging pathogen of farmed shrimp in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have suggested that pathogenicity is linked to particular lineages. Here, we performed high-throughput sequencing-based comparative genome analysis of 16 V. nigripulchritudo strains to explore the genomic diversity and evolutionary history of pathogen-containing lineages and to identify pathogen-specific genetic elements. Our phylogenetic analysis revealed three pathogen-containing V. nigripulchritudo clades, including two clades previously identified from New Caledonia and one novel clade comprising putatively pathogenic isolates from septicemic shrimp in Madagascar. The similar genetic distance between the three clades indicates that they have diverged from an ancestral population roughly at the same time and recombination analysis indicates that these genomes have, in the past, shared a common gene pool and exchanged genes. As each contemporary lineage is comprised of nearly identical strains, comparative genomics allowed differentiation of genetic elements specific to shrimp pathogenesis of varying severity. Notably, only a large plasmid present in all highly pathogenic (HP) strains encodes a toxin. Although less/non-pathogenic strains contain related plasmids, these are differentiated by a putative toxin locus. Expression of this gene by a non-pathogenic V. nigripulchritudo strain resulted in production of toxic culture supernatant, normally an exclusive feature of HP strains. Thus, this protein, here termed 'nigritoxin', is implicated to an extent that remains to be precisely determined in the toxicity of V. nigripulchritudo.

  3. OpaR controls a network of downstream transcription factors in Vibrio parahaemolyticus BB22OP.

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    Alison Kernell Burke

    Full Text Available Vibrio parahaemolyticus is an emerging world-wide human pathogen that is associated with food-borne gastroenteritis when raw or undercooked seafood is consumed. Expression of virulence factors in this organism is modulated by the phenomenon known as quorum sensing, which permits differential gene regulation at low versus high cell density. The master regulator of quorum sensing in V. parahaemolyticus is OpaR. OpaR not only controls virulence factor gene expression, but also the colony and cellular morphology associated with growth on a surface and biofilm formation. Whole transcriptome Next Generation sequencing (RNA-Seq was utilized to determine the OpaR regulon by comparing strains BB22OP (opaR+, LM5312 and BB22TR (∆opaR1, LM5674. This work, using the published V. parahaemolyticus BB22OP genome sequence, confirms and expands upon a previous microarray analysis for these two strains that used an Affymetrix GeneChip designed from the closely related V. parahaemolyticus RIMD2210633 genome sequence. Overall there was excellent correlation between the microarray and RNA-Seq data. Eleven transcription factors under OpaR control were identified by both methods and further confirmed by quantitative reverse transcription PCR (qRT-PCR analysis. Nine of these transcription factors were demonstrated to be direct OpaR targets via in vitro electrophoretic mobility shift assays with purified hexahistidine-tagged OpaR. Identification of the direct and indirect targets of OpaR, including small RNAs, will enable the construction of a network map of regulatory interactions important for the switch between the nonpathogenic and pathogenic states.

  4. Molecular Epidemiology and Genetic Variation of Pathogenic Vibrio parahaemolyticus in Peru

    Science.gov (United States)

    Gavilan, Ronnie G.; Zamudio, Maria L.; Martinez-Urtaza, Jaime

    2013-01-01

    Vibrio parahaemolyticus is a foodborne pathogen that has become a public health concern at the global scale. The epidemiological significance of V. parahaemolyticus infections in Latin America received little attention until the winter of 1997 when cases related to the pandemic clone were detected in the region, changing the epidemic dynamics of this pathogen in Peru. With the aim to assess the impact of the arrival of the pandemic clone on local populations of pathogenic V. parahaemolyticus in Peru, we investigated the population genetics and genomic variation in a complete collection of non-pandemic strains recovered from clinical sources in Peru during the pre- and post-emergence periods of the pandemic clone. A total of 56 clinical strains isolated in Peru during the period 1994 to 2007, 13 strains from Chile and 20 strains from Asia were characterized by Multilocus Sequence Typing (MLST) and checked for the presence of Variable Genomic Regions (VGRs). The emergence of O3:K6 cases in Peru implied a drastic disruption of the seasonal dynamics of infections and a shift in the serotype dominance of pathogenic V. parahaemolyticus. After the arrival of the pandemic clone, a great diversity of serovars not previously reported was detected in the country, which supports the introduction of additional populations cohabitating with the pandemic group. Moreover, the presence of genomic regions characteristic of the pandemic clone in other non-pandemic strains may represent early evidence of genetic transfer from the introduced population to the local communities. Finally, the results of this study stress the importance of population admixture, horizontal genetic transfer and homologous recombination as major events shaping the structure and diversity of pathogenic V. parahaemolyticus. PMID:23696906

  5. Prevalence and population structure of Vibrio vulnificus on fishes from the northern Gulf of Mexico.

    Science.gov (United States)

    Tao, Zhen; Larsen, Andrea M; Bullard, Stephen A; Wright, Anita C; Arias, Covadonga R

    2012-11-01

    The prevalence of Vibrio vulnificus on the external surfaces of fish from the northern Gulf of Mexico was determined in this study. A collection of 242 fish comprising 28 species was analyzed during the course of 12 sampling trips over a 16-month period. The prevalence of V. vulnificus was 37% but increased up to 69% in summer. A positive correlation was found between the percentages of V. vulnificus-positive fish and water temperatures, while salinity and V. vulnificus-positive fish prevalence were inversely correlated. A general lineal model (percent V. vulnificus-positive fish = 0.5930 - 0.02818 × salinity + 0.01406 × water temperature) was applied to best fit the data. Analysis of the population structure was carried out using 244 isolates recovered from fish. Ascription to 16S rRNA gene types indicated that 157 isolates were type A (62%), 72 (29%) were type B, and 22 (9%) were type AB. The percentage of type B isolates, considered to have greater virulence potential, was higher than that previously reported in oyster samples from the northern Gulf of Mexico. Amplified fragment length polymorphism (AFLP) was used to resolve the genetic diversity within the species. One hundred twenty-one unique AFLP profiles were found among all analyzed isolates, resulting in a calculated Simpson's index of diversity of 0.991. AFLP profiles were not grouped on the basis of collection date, fish species, temperature, or salinity, but isolates were clustered into two main groups that correlated precisely with 16S rRNA gene type. The population of V. vulnificus associated with fishes from the northern Gulf of Mexico is heterogeneous and includes strains of great virulence potential.

  6. Marine Lactobacillus pentosus H16 protects Artemia franciscana from Vibrio alginolyticus pathogenic effects.

    Science.gov (United States)

    Garcés, M E; Sequeiros, C; Olivera, N L

    2015-02-10

    Vibrio alginolyticus is an opportunistic pathogen which may affect different aquatic organisms. The aim of this study was to assess the probiotic properties and the protective mode of action of Lactobacillus pentosus H16 against V. alginolyticus 03/8525, through in vitro and in vivo studies using Artemia franciscana (hereafter Artemia). This strain showed antimicrobial activity against V. alginolyticus 03/8525 and Aeromonas salmonicida subsp. salmonicida ATCC33658 possibly related to lactobacilli organic acid production. It was able to survive at high rainbow trout bile concentrations and showed high selective adhesion to rainbow trout mucus (1.2×10(5)±8.0×10(3) cells cm(-2)). H16 outcompeted V. alginolyticus 03/8525 and A. salmonicida subsp. salmonicida ATCC33658, greatly reducing their adherence to rainbow trout mucus (64.8 and 74.1%, respectively). Moreover, H16 produced a cell-bound biosurfactant which caused an important decrease in the surface tension. H16 also protected Artemia nauplii against mortality when it was administered previous to V. alginolyticus 03/8525 inoculation. Furthermore, H16 bioencapsulated in Artemia, suggesting that it is possible to use live carriers in its administration. We conclude that the ability of L. pentosus H16 to selectively adhere to mucosal surfaces and produce cell-bound biosurfactants, displacing pathogenic strains, in addition to its antimicrobial activity, confer H16 competitive advantages against pathogens as demonstrated in in vivo challenge experiments. Thus, L. pentosus H16, a marine bacterium from the intestinal tract of hake, is an interesting probiotic for Artemia culture and also has the potential to prevent vibriosis in other aquaculture activities such as larvae culture and fish farming.

  7. Ecological fitness and virulence features of Vibrio parahaemolyticus in estuarine environments.

    Science.gov (United States)

    Lovell, Charles R

    2017-03-01

    Vibrio parahaemolyticus is a commonly encountered and highly successful organism in marine ecosystems. It is a fast-growing, extremely versatile copiotroph that is active over a very broad range of conditions. It frequently occurs suspended in the water column (often attached to particles or zooplankton), and is a proficient colonist of submerged surfaces. This organism is an important pathogen of animals ranging from microcrustaceans to humans and is a causative agent of seafood-associated food poisoning. This review examines specific ecological adaptations of V. parahaemolyticus, including its broad tolerances to temperature and salinity, its utilization of a wide variety of organic carbon and energy sources, and its pervasive colonization of suspended and stationary materials that contribute to its success and ubiquity in temperate and tropical estuarine ecosystems. Several virulence-related features are examined, in particular the thermostable direct hemolysin (TDH), the TDH-related hemolysin (TRH), and the type 3 secretion system, and the possible importance of these features in V. parahaemolyticus pathogenicity is explored. The impact of new and much more effective PCR primers on V. parahaemolyticus detection and our views of virulent strain abundance are also described. It is clear that strains carrying the canonical virulence genes are far more common than previously thought, which opens questions regarding the role of these genes in pathogenesis. It is also clear that virulence is an evolving feature of V. parahaemolyticus and that novel combinations of virulence factors can lead to emergent virulence in which a strain that is markedly more pathogenic evolves and propagates to produce an outbreak. The effects of global climate change on the frequency of epidemic disease, the geographic distribution of outbreaks, and the human impacts of V. parahaemolyticus are increasing and this review provides information on why this ubiquitous human pathogen has

  8. Analysis of the RNA degradosome complex in Vibrio angustum S14.

    Science.gov (United States)

    Erce, Melissa A; Low, Jason K K; Wilkins, Marc R

    2010-12-01

    The RNA degradosome is built on the C-terminal half of ribonuclease E (RNase E) which shows high sequence variation, even amongst closely related species. This is intriguing given its central role in RNA processing and mRNA decay. Previously, we have identified RhlB (ATP-dependent DEAD-box RNA helicase)-binding, PNPase (polynucleotide phosphorylase)-binding and enolase-binding microdomains in the C-terminal half of Vibrio angustum S14 RNase E, and have shown through two-hybrid analysis that the PNPase and enolase-binding microdomains have protein-binding function. We suggest that the RhlB-binding, enolase-binding and PNPase-binding microdomains may be interchangeable between Escherichia coli and V. angustum S14 RNase E. In this study, we used two-hybrid techniques to show that the putative RhlB-binding microdomain can bind RhlB. We then used Blue Native-PAGE, a technique commonly employed in the separation of membrane protein complexes, in a study of the first of its kind to purify and analyse the RNA degradosome. We showed that the V. angustum S14 RNA degradosome comprises at least RNase E, RhlB, enolase and PNPase. Based on the results obtained from sequence analyses, two-hybrid assays, immunoprecipitation experiments and Blue Native-PAGE separation, we present a model for the V. angustum S14 RNA degradosome. We discuss the benefits of using Blue Native-PAGE as a tool to analyse the RNA degradosome, and the implications of microdomain-mediated RNase E interaction specificity. © 2010 The Authors Journal compilation © 2010 FEBS.

  9. 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.

  10. RpoS controls the Vibrio cholerae mucosal escape response.

    Directory of Open Access Journals (Sweden)

    Alex Toftgaard Nielsen

    2006-10-01

    Full Text Available Vibrio cholerae causes a severe diarrhoeal disease by secreting a toxin during colonization of the epithelium in the small intestine. Whereas the initial steps of the infectious process have been intensively studied, the last phases have received little attention. Confocal microscopy of V. cholerae O1-infected rabbit ileal loops captured a distinctive stage in the infectious process: 12 h post-inoculation, bacteria detach from the epithelial surface and move into the fluid-filled lumen. Designated the "mucosal escape response," this phenomenon requires RpoS, the stationary phase alternative sigma factor. Quantitative in vivo localization assays corroborated the rpoS phenotype and showed that it also requires HapR. Expression profiling of bacteria isolated from ileal loop fluid and mucus demonstrated a significant RpoS-dependent upregulation of many chemotaxis and motility genes coincident with the emigration of bacteria from the epithelial surface. In stationary phase cultures, RpoS was also required for upregulation of chemotaxis and motility genes, for production of flagella, and for movement of bacteria across low nutrient swarm plates. The hapR mutant produced near-normal numbers of flagellated cells, but was significantly less motile than the wild-type parent. During in vitro growth under virulence-inducing conditions, the rpoS mutant produced 10- to 100-fold more cholera toxin than the wild-type parent. Although the rpoS mutant caused only a small over-expression of the genes encoding cholera toxin in the ileal loop, it resulted in a 30% increase in fluid accumulation compared to the wild-type. Together, these results show that the mucosal escape response is orchestrated by an RpoS-dependent genetic program that activates chemotaxis and motility functions. This may furthermore coincide with reduced virulence gene expression, thus preparing the organism for the next stage in its life cycle.

  11. 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.

  12. A Comprehensive Epidemiological Research for Clinical Vibrio parahaemolyticus in Shanghai

    Directory of Open Access Journals (Sweden)

    Huan Li

    2017-06-01

    Full Text Available Vibrio parahaemolyticus is one of the most important pathogen for seafood-borne gastroenteritis in Shanghai and the rest of the world. A total of 42 V. parahaemolyticus strains were isolated from 1900 fecal specimens collected from patients in Shanghai hospital presenting from January 2014 to December 2015. All isolates were evaluated for potential virulence factors [tdh, trh, and type three secretion system (T3SS genes], typed using multilocus sequence typing (MLST and screened for antimicrobial resistance phenotype and genotype. And for the first time, the relationship between virulence, genetic diversity and antimicrobial resistance of these isolates were identified. The results showed that 37 isolates carried the tdh gene (88.1% and only seven isolates were positive for the trh gene. The T3SS1 and T3SS2 genes were detected in all strains and only trh-positive isolates are also containing the T3SS2β genes. MLST analysis of the 42 Shanghai isolates identified 20 sequence types (STs with 16 novel STs and that these clinical V. parahaemolyticus strains showed high degrees of genetic diversity. All isolates expressed high levels of resistance against Ampicillin (100.0%, Streptomycin (100.0%, Cephazolin (92.9%, Kanamycin (92.8% and Amikacin (90.5%, and eight out of 38 resistance genes (SHV, tet(B, strA, qnrA, gryA, qnrB, sulI, sulII were detected in at least two isolates. This study confirms that antimicrobial resistance of clinical V. parahaemolyticus isolates is greater than those of environmental isolates. Furthermore, no clear correlation between antimicrobial resistance and virulence or genetic diversity was found in this study. These results add to epidemiological data of clinical V. parahaemolyticus isolates in Shanghai and highlight the need for additional mechanistic studies, especially antimicrobial resistance, to reduce the burden of disease caused by this pathogen in China.

  13. Detection of Vibrio splendidus and related species in Chamelea gallina sampled in the Adriatic along the Abruzzi coastline

    Directory of Open Access Journals (Sweden)

    Marina Torresi

    2011-09-01

    Full Text Available Vibrio species are an important and widespread component of marine microbial communities. Some Vibrio strains are potentially pathogenic to marine vertebrates and invertebrates. The aim of this study was to identify vibrios, in particular Vibrio splendidus and related species, isolated from clams (Chamelea gallina collected along the coasts of the Abruzzi region from May to October 2007. The isolates obtained were phenotyped and classified as belonging to the genus Vibrio. The strains underwent biochemical testing in accordance with Alsina’s scheme for V. splendidus identification. Molecular analysis of the 16S-23S intergenic space region and recA gene was used to identify V. splendidus and related species. All the samples examined were found to contain halophylic Vibrio species, with V. alginolyticus, V. splendidus-related species and V. mediterranei most commonly found. A polymerase chain reaction of the 16S-23S intergenic space region and sequencing of the recA gene from isolates confirmed that phenotyping of Vibrio species is not sufficient to distinguish between different species. Differentiation of the highly related species among V. splendidus-related clusters remains an important issue. In this regard, our data suggests sequencing the recA genes was far more discriminatory than sequencing 16S rDNA for this purpose.

  14. Abundance and distribution of Vibrio cholerae, V. parahaemolyticus, and V. vulnificus following a major freshwater intrusion into the Mississippi Sound.

    Science.gov (United States)

    Griffitt, Kimberly J; Grimes, D Jay

    2013-04-01

    In response to a major influx of freshwater to the Mississippi Sound following the opening of the Bonnet Carre Spillway, water samples were collected from three sites along the Mississippi shoreline to assess the impact of altered salinity on three pathogenic Vibrio species. Salinity readings across the affected area during the 2011 sample period ranged from 1.4 to 12.9 ppt (mean = 7.0) and for the 2012 sample period from 14.1 to 23.6 ppt (mean = 19.8). Analyses of the data collected in 2011 showed a reduction in densities of Vibrio parahaemolyticus and Vibrio vulnificus with a concurrent increase of Vibrio cholerae numbers, with V. cholerae becoming the only Vibrio detected once salinity readings dropped to 6 ppt. Follow-up samples taken in 2012 after recovery of the salinity in the sound showed that the relative densities of the three pathogenic vibrios had reverted back to normal levels. This study shows that although the spillway was open but a few weeks and the effects were therefore time limited, the Mississippi River water had a profound, if temporary, effect on Vibrio ecology in the Mississippi Sound.

  15. Activity of the Agrobacterium Ti plasmid conjugal transfer regulator TraR is inhibited by the product of the traM gene.

    OpenAIRE

    Fuqua, C; Burbea, M; Winans, S C

    1995-01-01

    The Agrobacterium Ti plasmid tra regulon was previously found to be positively regulated by the TraR protein in the presence of a diffusible N-acyl homoserine lactone designated Agrobacterium autoinducer (AAI). TraR and AAI are similar to LuxR from Vibrio fischeri and the Vibrio autoinducer (VAI), which regulate target bioluminescence (lux) genes in a cell density-dependent manner. We now show that tra genes are also regulated by a second protein, designated TraM, which acts to antagonize Tra...

  16. 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 rRNA and ...

  17. Prevalence and heterogeneity of Hemolysin gene vhh among hatchery isolates of Vibrio harveyi in India

    Digital Repository Service at National Institute of Oceanography (India)

    Parvathi, A.; George, J.; Kumar, S.

    , Baticados MCL, Cruz-Lacierda ER, de la Pena EL (1990) Occurrence of luminous bacterial disease of Penaeus monodon larvae in the Philippines. Aquaculture 91:1-13 19. Liu PC, Lee KK, Chen SN (1996) Pathogenicity of different isolates of Vibrio harveyi...

  18. Molecular Analysis and Toxigenic Potential of Vibrio cholerae Isolated from Hilsha fish (Tenualosa ilisha), Bangladesh

    DEFF Research Database (Denmark)

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

    Exposure to contaminated fish may upsurge the virulent strains of Vibrio cholerae, the deadly human pathogen in the households of rural and urban Bangladesh. Since V. cholerae spreading was reported from the Bay of Bengal, this study hypothesized that Hilsha (Tenualosa ilisha), a marine and fresh...

  19. Draft Genome Sequences of the Fish Pathogen Vibrio harveyi Strains VH2 and VH5

    DEFF Research Database (Denmark)

    Castillo, Daniel; D'Alvise, Paul; Middelboe, Mathias

    2015-01-01

    Vibrio harveyi is an important marine pathogen that is responsible for vibriosis outbreaks in cultured fish and invertebrates worldwide. Here, we announce the draft genome sequences of V. harveyi strains VH2 and VH5, isolated from farmed juvenile Seriola dumerili during outbreaks of vibriosis...

  20. Vibrio cholerae O1 from superficial water of the Tucunduba Stream, Brazilian Amazon

    Science.gov (United States)

    Sá, L.L.C.; Vale, E.R.V.; Garza, D.R.; Vicente, A.C.P.

    2012-01-01

    Isolation and genetic characterization of an environmental Vibrio cholerae O1 from the Amazon is reported. This strain lacks two major virulence factors - CTX and TCP - but carries other genes related to virulence. Genetic similarity with epidemic strains is evaluated and the importance of V. cholerae surveillance in the Amazon is emphasized. PMID:24031874

  1. Occurrence and distribution of Vibrio parahaemolyticus and related organisms in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Nair, S.; Chandramohan, D.

    The occurrence and distribution of Vibrio parahaemolyticus and related organisms were studied from offshore water samples (Lat. 10 degrees N and Long. 65 degrees to 69 degrees E) collected at 5, 10, 50, 100, 200 and 500 m depths and in the surface...

  2. Occurrence and distribution of Vibrio parahaemolyticus (Sakazaki et al) related organisms in the Laccadive Sea

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Ramaiah, N.; Chandramohan, D.

    The occurrence and distribution of Vibrio parahaemolyticus and related organisms were studied from offshore water samples (Lat. 10 degrees N and Long. 65 degrees to 69 degrees E) collected at 5, 10, 50, 100, 200 and 500 m depths and in the surface...

  3. 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.

  4. 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.

  5. Diversity of Vibrio spp in Karstic Coastal Marshes in the Yucatan Peninsula.

    Science.gov (United States)

    Ortiz-Carrillo, Icela; Estrella-Gómez, Neyi Eloísa; Zamudio-Maya, Marcela; Rojas-Herrera, Rafael

    2015-01-01

    Coastal bodies of water formed by the combination of seawater, underground rivers and rainwater comprise the systems with the greatest solar energy flow and biomass production on the planet. These characteristics make them reservoirs for a large number species, mainly microorganisms. Bacteria of the genus Vibrio are natural inhabitants of these environments and their presence is determined by variations in the nutrient, temperature and salinity cycles generated by the seasonal hydrologic behavior of these lagoon systems. This study determined the diversity of the genus Vibrio in 4 coastal bodies of water on the Yucatan Peninsula (Celestun Lagoon, Chelem Lagoon, Rosada Lagoon and Sabancuy Estuary). Using the molecular technique of 454 pyrosequencing, DNA extracted from water samples was analyzed and 32,807 reads were obtained belonging to over 20 culturable species of the genus Vibrio and related genera. OTU (operational taxonomic unit) richness and Chao2 and Shannon Weaver diversity indices were obtained with the database from this technique. Physicochemical and environmental parameters were determined and correlated with Vibrio diversity measured in OTUs.

  6. 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 complex...

  7. 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...

  8. PHYSIOCHEMICAL CONDITIONS AND CONTAMINATION WITH VIBRIOS OF SURFACE WATER AT MATLAB, BANGLADESH

    Directory of Open Access Journals (Sweden)

    Debasish Paul

    2012-10-01

    Full Text Available Cholera is water-borne infectious disease caused by Vibrio cholerae O1 and O139. Currently a proportion of people living in rural area like Matlab, Bangladesh are dependent on surface water for various purposes to surface water. People of the area are affected by cholera particularly in rainy seasons. We measured in situ the physicochemical parameters of water using portable meters and counted the Vibrio sp. from water, phytoplankton and zooplankton samples of river and pond water of Matlab, Bangladesh. The culturable Vibrios were counted thiosulfate-citrate-bile salts-sucrose agar (TCBS and taurocholate tellurite gelatin agar (TTGA plates and viable but nonculturable (VBNC by direct fluorescent microscopy. To confirm, we further did PCR of ompW gene and serology for V. cholerae O1/O139. Strong correlation of Vibrios cultural counts with pH, total coliform and faecal coliform heterotropic plate counts and viable but nonculturable (VBNC counts with only total dissolved solids (TDS noticed from the results. We identified 25 V. cholerae non-O1 and five V. cholerae O1 serotype which is main cause of cholera from water, phytoplankton and zooplankton samples of pond and rivers. Therefore, the present study indicated that the surface water sources are the main causes of cholera and reestablished the Matlab as epidemic area of Bangladesh.

  9. Diversity of Vibrio spp in Karstic Coastal Marshes in the Yucatan Peninsula

    Science.gov (United States)

    2015-01-01

    Coastal bodies of water formed by the combination of seawater, underground rivers and rainwater comprise the systems with the greatest solar energy flow and biomass production on the planet. These characteristics make them reservoirs for a large number species, mainly microorganisms. Bacteria of the genus Vibrio are natural inhabitants of these environments and their presence is determined by variations in the nutrient, temperature and salinity cycles generated by the seasonal hydrologic behavior of these lagoon systems. This study determined the diversity of the genus Vibrio in 4 coastal bodies of water on the Yucatan Peninsula (Celestun Lagoon, Chelem Lagoon, Rosada Lagoon and Sabancuy Estuary). Using the molecular technique of 454 pyrosequencing, DNA extracted from water samples was analyzed and 32,807 reads were obtained belonging to over 20 culturable species of the genus Vibrio and related genera. OTU (operational taxonomic unit) richness and Chao2 and Shannon Weaver diversity indices were obtained with the database from this technique. Physicochemical and environmental parameters were determined and correlated with Vibrio diversity measured in OTUs. PMID:26252792

  10. Vibrio parahaemolyticus: A Rare Cause of Chronic Diarrhea in a Heart Transplant Patient

    OpenAIRE

    Shuja, Asim; Dickstein, Aaron; Lee, Hannah M.

    2014-01-01

    Vibrio parahaemolyticus usually causes a self-limiting acute diarrheal illness, and is rarely tested for in cases of chronic diarrhea. We present a rare case of chronic diarrhea caused by V. parahaemolyticus in a heart transplant patient requiring antibiotic treatment.

  11. The Vibrio parahaemolyticus-infecting bacteriophage qdvp001: genome sequence and endolysin with a modular structure.

    Science.gov (United States)

    Wang, Weiyu; Li, Mengzhe; Lin, Hong; Wang, Jingxue; Mao, Xiangzhao

    2016-10-01

    Vibrio parahaemolyticus, a marine pathogen, is a causative agent of gastroenteritis in humans after consumption of contaminated seafood. In recent years, infections with V. parahaemolyticus have become an increasingly frequent factor in microbial food poisoning; therefore, it is urgent to figure out ways to control Vibrio parahaemolyticus. Endolysins, lytic enzymes encoded by bacteriophages, have been regarded as a therapeutic alternative to antibiotics in control of bacterial growth and have been successfully utilized in various areas. Here, we report the full genome sequence of the novel phage qdvp001, which lyses Vibrio parahaemolyticus 17802. The qdvp001 genome consists of a 134,742-bp DNA with a G+C content of 35.35 % and 227 putative open reading frames. Analysis revealed that the qdvp001 open reading frames encoded various putative functional proteins with a putative endolysin gene (ORF 60). No holin genes were identified in qdvp001. ORF 60 was cloned and expressed. The results showed that the purified endolysin Lysqdvp001 had a high hydrolytic activity toward Vibrio parahaemolyticus and a broader spectrum compared to that of the parental bacteriophage qdvp001. Thus, purified endolysin Lysqdvp001 has a potential to be used as an antibacterial agent in the future.

  12. Cerebral absces med Vibrio cholerae non-01 efter badning i dansk havvand

    DEFF Research Database (Denmark)

    Pedersen, Trine Torp; Nielsen, Xiaohui Chen; Olsen, Katharina Elisabeth Pribil

    2012-01-01

    We present the first case of intracerebral abscess after blood-borne infection with non-toxigenic Vibrio cholerae (non-01). The patient was a 66 year-old woman who was infected after swimming in Danish seawater during an unusually hot summer. She had predisposing haemochromatosis and a skin lesion...

  13. Prevalence and Molecular Typing of Vibrio parahaemolyticus (tdh+) isolated from seafood using PCR-based methods

    Science.gov (United States)

    Vibrio parahaemolyticus is a pathogen most frequently implicated in foodborne outbreaks linked to the consumption of seafood in the coastal cities of China. The pathogenicity of environmental V. parahaemolyticus is mostly correlated with the production of thermostable direct hemolysin (TDH). In orde...

  14. A checkpoint control orchestrates the replication of the two chromosomes of Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Marbouty, Martial; Martins, Francisco de Lemos

    2016-01-01

    of the important differences between plasmids and chromosomes is that the latter replicate during a defined period of the cell cycle, ensuring a single round of replication per cell. Vibrio cholerae carries two circular chromosomes, Chr1 and Chr2, which are replicated in a well-orchestrated manner with the cell...

  15. Molecular phylogenetic analysis of Vibrio cholerae O1 El Tor strains ...

    Indian Academy of Sciences (India)

    Unknown

    all five ISR classes, could be successfully used to study phylogeny in this organism. [Ghatak A, Majumdar A and Ghosh R K 2005 Molecular phylogenetic analysis of Vibrio cholerae O1 El Tor strains isolated before, during and after the O139 outbreak based on the intergenomic heterogeneity of the 16S-23S rRNA intergenic ...

  16. 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...

  17. A survey of Vibrio cholerae O1 and O139 in estuarine waters and ...

    African Journals Online (AJOL)

    This study determined whether the estuarine and freshwater environment in Beira, Mozambique, serves as a reservoir of Vibrio cholerae O1 and O139. Ninety-nine estuarine water samples were collected at 6 sites in Beira. An additional 54 samples were collected from rural areas around Beira which included 3 freshwater ...

  18. [MALDI-TOF mass-spectrometric analysis in the accelerated identification of the Vibrio genus microorganisms].

    Science.gov (United States)

    Afanasev, M V; Mironova, L V; Basov, E A; Ostyak, A S; Kulikalova, E S; Urbanovich, L Ya; Balahonov, S V

    2014-01-01

    The goal of this work was to develop methodological approaches to identification of the Vibrio genus representatives using the MALDI-TOF mass-spectrometric analysis technologies. The aspects of the biological safety in sample preparations for mass-spectrometric analysis were studied, reference spectra of six typical V. cholerae strains were developed. Identification of 55 strains, representatives of the Vibrio genus, including 45 V. cholerae strains with different epidemic importance, was performed using the MALDI Biotyper 3.0 basis comprising V. cholerae reference spectra. The possibility of reliable definition of the tested strain taxonomic belonging to the species level was demonstrated. Thus, the results completely corresponded to the data of classical microbiological identification. Stability and reproducibility of the offered research method was experimentally shown. The results allow identification of the Vibrio genus representatives to be implemented with the use of the mass-spectrometric analysis as an effective method that defines a species belonging of the basic Vibrio genus representatives in the shortest-terms.

  19. Vibrio vulnificus outbreaks in Dutch eel farms since 1996: strain diversity and impact.

    NARCIS (Netherlands)

    Haenen, O.L.M.; Zanten, van E.; Jansen, R.; Roozenburg, I.; Engelsma, M.Y.; Dijkstra, A.; Boers, S.A.; Voorbergen-Laarman, M.; Möller, A.V.M.

    2014-01-01

    Vibrio vulnificus is a potentially zoonotic bacterial pathogen of fish, which can infect humans (causing necrotic fasciitis). We analysed 24 V. vulnificus isolates (from 23 severe eel disease outbreaks in 8 Dutch eel farms during 1996 to 2009, and 1 clinical strain from an eel farmer) for genetic

  20. Migratory deficiency of Clithon retropictus hemocytes to Vibrio parahaemolyticus and Escherichia coli.

    Science.gov (United States)

    Kumazawa, N H; Kato, E; Okamoto, Y

    1990-08-01

    Hemocytes of a marine gastropod, Nerita albicilla, but not those of an estuarine gastropod, Clithon retropictus, were observed to migrate to live and heat-killed cells of Vibrio parahaemolyticus and Escherichia coli through Nucleopore membrane in Blind well chamber. The defective migration of C. retropictus hemocytes might reflect, at least in part, the survival of V. parahaemolyticus in the estuarine gastropod.

  1. 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.

  2. NCBI nr-aa BLAST: CBRC-FCAT-01-0604 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-FCAT-01-0604 ref|YP_205428.1| maltose transport system permease protein MalG [Vibrio fischer...i ES114] gb|AAW86540.1| maltose transport system permease protein MalG [Vibrio fischeri ES114] YP_205428.1 1.1 31% ...

  3. NCBI nr-aa BLAST: CBRC-CINT-01-0194 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CINT-01-0194 ref|YP_206739.1| ferrichrome transport system permease protein FhuB [Vibrio fischer...i ES114] gb|AAW87851.1| ferrichrome transport system permease protein FhuB [Vibrio fischeri ES114] YP_206739.1 0.15 24% ...

  4. NCBI nr-aa BLAST: CBRC-RMAC-21-0022 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-RMAC-21-0022 ref|YP_203452.1| chloramphenicol-sensitive protein RarD [Vibrio fischer...i ES114] gb|AAW84564.1| chloramphenicol-sensitive protein RarD [Vibrio fischeri ES114] YP_203452.1 0.015 24% ...

  5. NCBI nr-aa BLAST: CBRC-AGAM-07-0003 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0003 ref|YP_205202.1| heme chaperone--apocytochrome heme-lyase [Vibrio fischer...i ES114] gb|AAW86314.1| heme chaperone--apocytochrome heme-lyase [Vibrio fischeri ES114] YP_205202.1 3e-70 67% ...

  6. NCBI nr-aa BLAST: CBRC-AGAM-07-0016 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0016 ref|YP_203424.1| chloramphenicol resistance protein [Vibrio fischer...i ES114] gb|AAW84536.1| chloramphenicol resistance protein [Vibrio fischeri ES114] YP_203424.1 2e-54 54% ...

  7. Selection of a Battery of Rapid Toxicity Sensors for Drinking Water Evaluation

    Science.gov (United States)

    2006-01-01

    Strategic Diagnostics, nc., Newark, DE) measured changes in natural bioluminescence roduced by the marine bacteria Vibrio fischeri (Bulich, 1979...tates et al., 2003). Toxic substances decreased light output, hich was measured using a photometer.Vibrio fischeri supplied n a standard freeze-dried

  8. Antisense RNA that Affects Rhodopseudomonas palustris Quorum-Sensing Signal Receptor Expression

    Science.gov (United States)

    2012-01-01

    a selectable DNA fragment. Gene 29:303–313. 17. Egland KA, Greenberg EP (1999) Quorum sensing in Vibrio fischeri : Elements of the luxl promoter. Mol...terminal region of the Vibrio fischeri LuxR pro- tein contains an inducer-independent lux gene activating domain. Proc Natl Acad Sci USA 88:11115

  9. Detection of Pathogenic Organisms in Food, Water and Body (Postprint)

    Science.gov (United States)

    2002-06-27

    originally cloned from the marine bacterium Vibrio fischeri . The bioluminescent (lux) genes from bacteria have been genetically and biochemically...bacteriophage specific for pathogenic bacteria. The bioreporter design will incorporate a lux gene from Vibrio fischeri into the genome of the

  10. Empowerment perceptions of educational managers from previously ...

    African Journals Online (AJOL)

    The perceptions of educational manag ers from previously disadvantaged primary and high schools in the Nelson Mandela Metropole regarding the issue of empowerment are outlined and the perceptions of educational managers in terms of various aspects of empowerment at different levels reflected. A literature study ...

  11. Knowledge and Previous Contraceptive Use by Pregnant ...

    African Journals Online (AJOL)

    Information obtained included demographic characteristics, knowledge of and previous use of contraception. Results: Respondents displayed a high level of contraceptive knowledge, as 277 (91.7%) were aware of it. The condom and the combined oral pill were the two contraceptive methods most commonly known, by 254 ...

  12. Subsequent pregnancy outcome after previous foetal death

    NARCIS (Netherlands)

    Nijkamp, J. W.; Korteweg, F. J.; Holm, J. P.; Timmer, A.; Erwich, J. J. H. M.; van Pampus, M. G.

    Objective: A history of foetal death is a risk factor for complications and foetal death in subsequent pregnancies as most previous risk factors remain present and an underlying cause of death may recur. The purpose of this study was to evaluate subsequent pregnancy outcome after foetal death and to

  13. Laboratory Grouping Based on Previous Courses.

    Science.gov (United States)

    Doemling, Donald B.; Bowman, Douglas C.

    1981-01-01

    In a five-year study, second-year human physiology students were grouped for laboratory according to previous physiology and laboratory experience. No significant differences in course or board examination performance were found, though correlations were found between predental grade-point averages and grouping. (MSE)

  14. Clinical manifestations of non-O1 Vibrio cholerae infections.

    Directory of Open Access Journals (Sweden)

    Yen-Ting Chen

    Full Text Available BACKGROUND: Infections caused by non-O1 Vibrio cholera are uncommon. The aim of our study was to investigate the clinical and microbiological characteristics of patients with non-O1 V. cholera infections. METHODS: The clinical charts of all patients with non-O1 V. cholera infections and who were treated in two hospitals in Taiwan were retrospectively reviewed. RESULTS: From July 2009 to June 2014, a total of 83 patients with non-O1 V. cholera infections were identified based on the databank of the bacteriology laboratories of two hospitals. The overall mean age was 53.3 years, and men comprised 53 (63.9% of the patients. Liver cirrhosis and diabetes mellitus were the two most common underlying diseases, followed by malignancy. The most common type of infection was acute gastroenteritis (n = 45, 54.2%, followed by biliary tract infection (n = 12, 14.5% and primary bacteremia (n = 11, 13.3%. Other types of infection, such as peritonitis (n = 5, 6.0%, skin and soft tissue infection (SSTI (n = 5, 6.0%, urinary tract infection (n = 3, 3.6% and pneumonia (2, 2.4%, were rare. July and June were the most common months of occurrence of V. cholera infections. The overall in-hospital mortality of 83 patients with V. cholera infections was 7.2%, but it was significantly higher for patients with primary bacteremia, hemorrhage bullae, acute kidney injury, acute respiratory failure, or admission to an ICU. Furthermore, multivariate analysis showed that in-hospital mortality was significantly associated with acute respiratory failure (odds ratio, 60.47; 95% CI, 4.79-763.90, P = 0.002. CONCLUSIONS: Non-O1 V. cholera infections can cause protean disease, especially in patients with risk factors and during warm-weather months. The overall mortality of 83 patients with non-O1 V. cholera infections was only 7.2%; however, this value varied among different types of infection.

  15. Diversity of vibrios in the haemolymph of the spider crab Maja brachydactyla.

    Science.gov (United States)

    Gomez-Gil, B; Roque, A; Lacuesta, B; Rotllant, G

    2010-09-01

    The aim of this study was to characterise and identify vibrios isolated from the haemolymph of apparently healthy adult spider crabs (Maja brachydactyla) wild-caught in the Spanish localities of Galician coast and in the Canary Islands and also from captive animals held at IRTA's facilities in the Ebro Delta of Catalonia, north-west Spanish Mediterranean coast. A total of 277 bacterial isolates were obtained, and of these, 171 were characterised with rep-PCR, resulting electrophoretic bands were analysed and clusters formed. Identification of representative strains of each cluster was made by sequencing the 16S rRNA. Samples from animals caught in Galicia and captive at IRTA (around 15-18°C) rendered mostly species belonging to the Splendidus clade (72·2 and 76·6% respectively), commonly found in cold waters (below 20°C). Higher species diversity was found in the haemolymph of the captive animals. In the warmer Canary Islands waters (around 21°C), the diversity of vibrios is dominated by three clades, Harveyi (Vibrio core group, 39·3%), Orientalis (23·2%) and Splendidus (21·4%) with a species diversity that equals that of the colder captive animals. Differences in the vibrios populations were found in the haemolymph extracted from animals collected from the three localities. Potential new species were found, and their description is under way. As with other invertebrates, spider crabs also contain a diverse population of vibrios. These findings should help researchers to diagnose when a crab is infected. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

  16. The Vibrio cholerae cytolysin promotes chloride secretion from intact human intestinal mucosa.

    Directory of Open Access Journals (Sweden)

    Lucantonio Debellis

    Full Text Available BACKGROUND: The pathogenicity of the Vibrio cholerae strains belonging to serogroup O1 and O139 is due to the production of virulence factors such as cholera toxin (CT and the toxin-coregulated pilus (TCP. The remaining serogroups, which mostly lack CT and TCP, are more frequently isolated from aquatic environmental sources than from clinical samples; nevertheless, these strains have been reported to cause human disease, such as sporadic outbreaks of watery diarrhoea and inflammatory enterocolitis. This evidence suggested the possibility that other virulence factor(s than cholera toxin might be crucial in the pathogenesis of Vibrio cholerae-induced diarrhoea, but their nature remains unknown. VCC, the hemolysin produced by virtually all Vibrio cholerae strains, has been proposed as a possible candidate, though a clear-cut demonstration attesting VCC as crucial in the pathogenesis of Vibrio cholerae-induced diarrhoea is still lacking. METHODOLOGY/PRINCIPAL FINDINGS: Electrophysiological parameters and paracellular permeability of stripped human healthy colon tissues, obtained at subtotal colectomy, mounted in Ussing chamber were studied in the presence or absence of VCC purified from culture supernatants of V. cholerae O1 El Tor strain. Short circuit current (I(SC and transepithelial resistance (R(T were measured by a computerized voltage clamp system. The exposure of sigmoid colon specimens to 1 nM VCC resulted in an increase of I(SC by 20.7%, with respect to the basal values, while R(T was reduced by 12.3%. Moreover, increase in I(SC was abolished by bilateral Cl(- reduction. CONCLUSION/SIGNIFICANCE: Our results demonstrate that VCC, by forming anion channels on the apical membrane of enterocytes, triggers an outward transcellular flux of chloride. Such an ion movement, associated with the outward movement of Na(+ and water, might be responsible for the diarrhoea caused by the non-toxigenic strains of Vibrio cholerae.

  17. Variable Virulence of Biotype 3 Vibrio vulnificus due to MARTX Toxin Effector Domain Composition.

    Science.gov (United States)

    Kim, Byoung Sik; Gavin, Hannah E; Satchell, Karla J F

    2017-01-01

    Vibrio vulnificus is an environmental organism that causes septic human infections characterized by high morbidity and mortality. The annual incidence and global distribution of this pathogen are increasing as ocean waters warm. Clinical strains exhibit variations in the primary virulence toxin, suggesting a potential for the emergence of new strains with altered virulence properties. A clonal outbreak of tilapia-associated wound infections in Israel serves as a natural experiment for the sudden emergence of a new V. vulnificus strain. The effector domain content of the multifunctional autoprocessing RTX (MARTX) toxin of the outbreak-associated biotype 3 (BT3) strains was previously shown to harbor a modification generated by recombination. The modification introduced an actin-induced adenylate cyclase effector domain (ExoY) and an effector domain that disrupts the Golgi organelle (DmX). Here, we report that the exchange of these effector domains for a putative progenitor biotype 1 toxin arrangement produces a toxin that slows the lysis kinetics of targeted epithelial cells but increases cellular rounding phenotypes in response to bacteria. In addition, replacing the biotype 3 toxin variant with the putative progenitor biotype 1 variant renders the resulting strain significantly more virulent in mice. This suggests that the exchange of MARTX effector domains during the emergence of BT3 generated a toxin with reduced toxin potency, resulting in decreased virulence of this outbreak-associated strain. We posit that selection for reduced virulence may serve as a route for this lethal infectious agent to enter the human food chain by allowing it to persist in natural hosts. IMPORTANCEVibrio vulnificus is a serious infection linked to climate change. The virulence capacity of these bacteria can vary by gene exchange, resulting in new variants of the primary virulence toxin. In this study, we tested whether the emergence of an epidemic strain of V. vulnificus with a

  18. Vibrio cholerae/mimicus in fecal microbiota of healthy children in a cholera endemic urban slum setting in Kolkata, India

    National Research Council Canada - National Science Library

    Nair, Gopinath Balakrish; Ramamurthy, Thandavarayan; Sur, Dipika; Kurakawa, Takashi; Takahashi, Takuya; Nomoto, Koji; Takeda, Yoshifumi

    2012-01-01

    During a double‐blind, randomized, placebo‐controlled probiotic trial among 3758 children residing in an urban slum in Kolkata, India, Vibrio cholerae / mimicus was detected in fecal microbiota of healthy children...

  19. Amplification of tlh gene in other Vibrionaceae specie by specie-specific multiplex PCR of Vibrio parahaemolyticus

    National Research Council Canada - National Science Library

    Romina Yáñez; Roberto Bastías; Gastón Higuera; Oscar Salgado; Pantelis Katharios; Jaime Romero; Romilio Espejo; Katherine García

    2015-01-01

    Background: The surveillance of Vibrio parahaemolyticus in the Chilean coast has been mainly performed by multiplex PCR amplification of three different hemolysin genes, which are specie-specific virulence factors...

  20. Daya Hambat Ekstrak Daun Pegagan (Centella asiatica yang Diambil di Batusangkar terhadap Pertumbuhan Kuman Vibrio cholerae secara In Vitro

    Directory of Open Access Journals (Sweden)

    Nelvita Sari Ramadhan

    2015-01-01

    Full Text Available AbstrakPegagan (Centella asiatica merupakan salah satu tanaman yang digunakan sebagai obat. Salah satu manfaat yang bisa didapatkan dari pegagan (Centella asiatica adalah antibakterinya. Manfaat antibakterinya didapatkan karena pegagan (Centella asiatica mengandung zat antibakteri, diantaranya adalah saponin, tannin, alkaloid, dan flavonoid. Telah dilakukan penelitian tentang daya hambat ekstrak pegagan (Centella asiatica terhadap pertumbuhan Vibrio cholerae secara in vitro, dengan tujuan untuk mengetahui daya hambat ekstrak pegagan (Centella asiatica terhadap pertumbuhan Vibrio cholera secara in vitro. Penelitian dilakukan dengan metode eksperimental laboratorium dengan metode difusi (cakram, pada berbagai konsentrasi yaitu 5%, 10%, 20%, 30%, 40%, 50%, dan100%, di Laboratorium Mikrobiologi Fakultas Kedokteran Universitas Andalas. Hasil penelitian didapatkan bahwa ekstrak daun pegagan (Centella asiatica yang diambil di daerah Batusangkar, ternyata tidak dapat menghambat pertumbuhan kuman Vibrio cholerae secara in vitro, sedangkan tetrasiklin yang digunakan sebagai kontrol positif memberikan daya hambat yang baik terhadap pertumbuhan Vibrio cholera, dengan zona hambat 16,3 mm. Ada atau tidaknya daya hambat ekstrak pegagan (Centella asiatica terhadap pertumbuhan Vibrio cholerae dalam penelitian ini bisa dipengaruhi oleh jenis bakteri yang digunakan, metode pembuatan ekstrak yang dipakai, dan sumber daun pegagan yang digunakan dalam penelitian.Kata kunci: efek antibakteri, ekstrak daun pegagan (Centella asiatica, Vibrio choleraeAbstractCentella asiatica is one of the plants used as medicine. One of the benefits that can be obtained from Centella asiatica is an antibacterial effect. Antibacterial effect obtained as Centella asiatica contains anti-bacterial substances, such as saponins, tannins, alkaloids, and flavonoids. This study was conducted to determine the inhibition of extracts of Centella asiatica on the growth of Vibrio cholerae in vitro