| sensitivity of different aquatic bioassays in the assessment of a new natural formicide. | agrochemicals have the potential to cause deleterious effects on living organisms and therefore they must be subjected to various (eco)toxicological studies and monitoring programs in order to protect human health and the environment. the aim of this study was to assess the ecotoxicity of a new natural formicide with a battery of three classical and three ecotox-kit tests. the former tests were performed with aliivibrio fischeri bacteria (lumistox test), the cladoceran daphnia magna and pseudoki ... | 2013 | 23030441 |
| Assessment of Landfill Leachate Toxicity Reduction After Biological Treatment. | In the present article, the efficiency of biological treatment of landfill leachates was evaluated by implementation of physicochemical characterisation and a complex toxicity assessment. An array of toxicity tests using bacterium Vibrio fischeri, alga Desmodesmus subspicatus, crustacean Daphnia magna, and embryo of fish Danio rerio, as well as unconventional methods using biochemical biomarkers (protein content, enzymes cholinesterase, and glutathione-S-transferase), were employed. Toxicity of ... | 2011 | 21858736 |
| water recycle as a must: decolorization of textile wastewaters by plant-associated fungi. | textile dye effluents are among the most problematic pollutants because of their toxicity on several organisms and ecosystems. low cost and ecocompatible bioremediation processes offer a promising alternative to the conventional and aspecific physico-chemical procedures adopted so far. here, microorganisms resident on three real textile dyeing effluent were isolated, characterized, and tested for their decolorizing performances. although able to survive on these real textile-dyeing wastewaters, ... | 2014 | 23553673 |
| mechanism-specific and whole-organism ecotoxicity of mono-rhamnolipids. | biosurfactants like rhamnolipids are promising alternatives to chemical surfactants in a range of applications. a wider use requires an analysis of their environmental fate and their ecotoxicological potential. in the present study mono-rhamnolipids produced by a recombinant pseudomonas putida strain were analyzed using the green toxicology concept for acute and mechanism-specific toxicity in an ecotoxicological test battery. acute toxicity tests with the invertebrate daphnia magna and with zebr ... | 2016 | 26802344 |
| high levan production by bacillus licheniformis ns032 using ammonium chloride as the sole nitrogen source. | in this study, levan production by bacillus licheniformis ns032 isolated from a petroleum sludge sample was investigated. high levan yield was obtained in a wide range of sucrose concentrations (up to 400 g/l) and, contrary to most levan-producing strains, using ammonium chloride as the sole n source. interaction between sucrose, ammonium chloride, and initial ph of the medium in a low sucrose (60-200 g/l) and a high sucrose (300-400 g/l) system was analyzed by response surface methodology. acco ... | 2015 | 25592434 |
| aquatic toxicity and biodegradability of a surfactant produced by bacillus subtilis ica56. | in this work, the environmental compatibility of a biosurfactant produced by a bacillus subtilis strain isolated from the soil of a brazilian mangrove was investigated. the biosurfactant, identified as surfactin, is able to reduce surface tension (st) to 31.5 ± 0.1 mn m(-1) and exhibits a lowcritical micelle concentration (cmc) value (0.015 ± 0.003 g l(-1)). the highest crude biosurfactant concentration (224.3 ± 1.9 mg l(-1)) was reached at 72 h of fermentation. acute toxicity tests, carried out ... | 2017 | 27791474 |
| derivation of guideline values for gold (iii) ion toxicity limits to protect aquatic ecosystems. | this study focused on estimating the toxicity values of various aquatic organisms exposed to gold (iii) ion (au(3+)), and to propose maximum guideline values for au(3+) toxicity that protect the aquatic ecosystem. a comparative assessment of methods developed in australia and new zealand versus the european community (ec) was conducted. the test species used in this study included two bacteria (escherichia coli and bacillus subtilis), one alga (pseudokirchneriella subcapitata), one euglena (eugl ... | 2014 | 24094731 |
| Acute and chronic toxicity of four frequently used UV filter substances for Desmodesmus subspicatus and Daphnia magna. | As a consequence of growing public concern about UV radiation effects on human health chemical and physical UV filters are increasingly used in personal care and other products. The release of these lipophilic and often persistent compounds into surface waters may pose a risk for aquatic organisms. The aim of the study was to determine effects of four frequently used UV filters on primary aquatic producers and consumers, the green alga Desmodesmus subspicatus and the crustacean Daphnia magna. Ex ... | 2011 | 21929467 |
| evaluation of the hazardous impact of landfill leachates by toxicity and biodegradability tests. | the aim of our research was to assess the ecotoxicity and biodegradability of leachates originating from two parts of a municipal landfill before and after biological treatment in the existing treatment plant. biotests represent important tools for adequate environmental characterization of landfill leachates and could be helpful in reliable assessment and monitoring of the treatment plant efficiency. for ecotoxicity testing of landfill leachate before and after biological treatment, different o ... | 2011 | 21970176 |
| a contribution towards the risk assessment of soils from the são domingos mine (portugal): chemical, microbial and ecotoxicological indicators. | this study is a contribution towards a risk assessment of the são domingos mine area (portugal), integrating information from: soil physicochemical characteristics, pseudo-total and bioavailable trace elements (as, cd, cr, cu, ni, pb and zn), ecotoxicological evaluation, and microbial indicators. the bioassays using soil eluates (seed germination, luminescent inhibition of vibrio fischeri and daphnia magna immobilization) confirmed the soil toxicity categorization obtained with the bioassays usi ... | 2012 | 22230067 |
| a novel approach to parasite population genetics: experimental infection reveals geographic differentiation, recombination and host-mediated population structure in pasteuria ramosa, a bacterial parasite of daphnia. | the population structure of parasites is central to the ecology and evolution of host-parasite systems. here, we investigate the population genetics of pasteuria ramosa, a bacterial parasite of daphnia. we used natural p. ramosa spore banks from the sediments of two geographically well-separated ponds to experimentally infect a panel of daphnia magna host clones whose resistance phenotypes were previously known. in this way, we were able to assess the population structure of p. ramosa based on g ... | 2012 | 23279064 |
| local genetic adaptation generates latitude-specific effects of warming on predator-prey interactions. | temperature effects on predator-prey interactions are fundamental to better understand the effects of global warming. previous studies never considered local adaptation of both predators and prey at different latitudes, and ignored the novel population combinations of the same predator-prey species system that may arise because of northward dispersal. we set up a common garden warming experiment to study predator-prey interactions between ischnura elegans damselfly predators and daphnia magna zo ... | 2012 | 23504827 |
| daphnia intoxicated by nerve agent tabun can be treated using human antidotes. | application of human antidotes against nerve agent intoxications to microcrustacean daphnia magna (crustacea, cladocera) intoxicated by a nerve agent tabun (o-ethyl-n,n-dimethylphosphoramidocyanidate) and their efficacy was investigated. it was found that antidotes can be successfully applied to intoxicated daphnids. three different treatment regimens were tested: the combination of atropine and acetylcholinesterase reactivator (trimedoxime was chosen), atropine only and trimedoxime alone, too. ... | 2008 | 21783870 |
| protein and nucleic acid content in daphnia magna during chronic exposure to cadmium. | daphnia magna straus were exposed to cadmium concentrations of 0, 0.4, 0.8, 2.1, 4.3, and 7.2 micrograms/liter for 21 days. protein, rna, dna, glycogen and lipid content were measured after 4, 7, and 21 days of exposure, and the results were related to survival and reproduction. the no observed effect concentration (noec) for survival, protein growth, and reproduction at day 21 was 2.1, 0.8, and 0.8 microgram/liter cadmium, respectively. protein growth was most sensitive to cadmium exposure foll ... | 2007 | 2440658 |
| ecotoxicity assessment of particulate matter emitted from heavy-duty diesel-powered vehicles: influence of leaching conditions. | concerns regarding the environmental impact of diesel exhaust particulate matter (dpm) have increased in recent years. following emission to the atmosphere, these fine materials can sorb many contaminants at their surface, which can subsequently be released, for instance, due to physicochemical environmental changes. the desorption of contaminants from particulate matter will increase the environmental pollution and can promote ecotoxicological effects. in this context, the objective of this stu ... | 2017 | 28233212 |
| sensitivity of ethiopian aquatic macroinvertebrates to the pesticides endosulfan and diazinon, compared to literature data. | the aims of the present study were to present a methodology for toxicity tests that can be used when analytical resources to verify the test concentrations are limited, and to evaluate whether the sensitivity of a limited number of ethiopian species to pesticides differs from literature values for, mainly, temperate species. acute toxicity tests were performed using three ethiopian aquatic invertebrate species, one crustacean (diaphanosoma brachyurum) and two insects (anopheles pharoensis and cu ... | 2016 | 27221822 |
| purification and studies on characteristics of cholinesterases from daphnia magna. | due to their significant value in both economy and ecology, daphnia had long been employed to investigate in vivo response of cholinesterase (che) in anticholinesterase exposures, whereas the type constitution and property of the enzyme remained unclear. a type of che was purified from daphnia magna using a three-step procedure, i.e., triton x-100 extraction, ammonium sulfate precipitation, and diethylaminoethyl (deae)-sepharose™-fast-flow chromatography. according to sodium dodecyl sulfate poly ... | 0 | 23549850 |
| correlation between acute toxicity for daphnia magna, aliivibrio fischeri and physicochemical variables of the leachate produced in landfill simulator reactors. | due to the diversified nature of municipal solid waste and the different stages of its decomposition, the formed leachates result in a complex chemical mixture with toxic potential. these chemicals can cause environmental problems, such as the contamination of surface or groundwater, thus affecting the balance of aquatic ecosystems. the aim of our study was to evaluate the acute toxicity of leachates in daphnia magna and aliivibrio fischeri and to identify the main physicochemical variables that ... | 2017 | 28076700 |
| antimicrobial filtration with electrospun poly(vinyl alcohol) nanofibers containing benzyl triethylammonium chloride: immersion, leaching, toxicity, and filtration tests. | antimicrobial electrospun poly(vinyl alcohol) (pva) nanofibers were synthesized by impregnating benzyl triethylammonium chloride (bteac) as an antimicrobial agent into pva nanofibers. the bteac-pva nanofibers were heat-methanol treated during the preparation for various tests. the bteac-pva nanofibers became more hydrophilic than the pva nanofibers due to incorporation of bteac. through heat-methanol treatment, thermal property, crystallinity, and water stability of bteac-pva nanofibers were imp ... | 2017 | 27750171 |
| an integrated study on antimicrobial activity and ecotoxicity of quantum dots and quantum dots coated with the antimicrobial peptide indolicidin. | this study attempts to evaluate the antimicrobial activity and the ecotoxicity of quantum dots (qds) alone and coated with indolicidin. to meet this objective, we tested the level of antimicrobial activity on gram-positive and gram-negative bacteria, and we designed an ecotoxicological battery of test systems and indicators able to detect different effects using a variety of end points. the antibacterial activity was analyzed against staphylococcus aureus (atcc 6538), pseudomonas aeruginosa (atc ... | 2017 | 27616887 |
| development of phytotoxicity indexes and their correlation with ecotoxicological, stability and physicochemical parameters during passive composting of poultry manure. | both raw and composted poultry manure is applied as soil amendment. the aims of this study were: (1) to develop phytotoxicity indexes for organic wastes and composts, and (2) to assess the correlation among phytotoxicity indexes, ecotoxicological endpoints and stability and physicochemical parameters during passive composting of poultry manure. six 2-m(3) composting piles were constructed and four parameter groups (physicochemical and microbiological parameters, ecotoxicological endpoints, and b ... | 2016 | 27185192 |
| the time is right to focus on model organism metabolomes. | model organisms are an essential component of biological and biomedical research that can be used to study specific biological processes. these organisms are in part selected for facile experimental study. however, just as importantly, intensive study of a small number of model organisms yields important synergies as discoveries in one area of science for a given organism shed light on biological processes in other areas, even for other organisms. furthermore, the extensive knowledge bases compi ... | 2016 | 26891337 |
| inactivation mechanism of chlorination in escherichia coli internalized in limnoithona sinensis and daphnia magna. | zooplankton may harbor microorganisms in the aquatic environment, thus protecting them from disinfection during drinking water treatment. however, few studies have evaluated the protective effect of internalization by zooplankton against bacterial disinfection. in this study, we investigated the role of zooplankton (limnoithona sinensis and daphnia magna) as a refuge for ingested bacteria against inactivation by chlorination. only 30% of chlorine reached the internalized bacteria inside the dige ... | 2016 | 26624518 |
| lanthanide ecotoxicity: first attempt to measure environmental risk for aquatic organisms. | the geochemical cycles of lanthanides are being disrupted by increasing global production and human use, but their ecotoxicity is not fully characterized. in this study, the sensitivity of aliivibrio fischeri and pseudokirchneriella subcapitata to lanthanides increased with atomic number, while daphnia magna, heterocypris incongruens, brachionus calyciflorus and hydra attenuata were equally sensitive to the tested elements. in some cases, a marked decrease in exposure concentrations was observed ... | 2015 | 25645063 |
| common transcriptional mechanisms for visual photoreceptor cell differentiation among pancrustaceans. | a hallmark of visual rhabdomeric photoreceptors is the expression of a rhabdomeric opsin and uniquely associated phototransduction molecules, which are incorporated into a specialized expanded apical membrane, the rhabdomere. given the extensive utilization of rhabdomeric photoreceptors in the eyes of protostomes, here we address whether a common transcriptional mechanism exists for the differentiation of rhabdomeric photoreceptors. in drosophila, the transcription factors pph13 and orthodenticl ... | 2014 | 24991928 |
| arsenate (as v) in water: quantitative sensitivity relationships among biomarker, ecotoxicity and genotoxicity endpoints. | it is useful to test ecotoxicity and genotoxicity endpoints in the environmental impact assessment. here, we compare and discuss ecotoxicity and genotoxicity effects in organisms in response to exposure to arsenate (as v) in solution. eco(geno)toxicity responses in aliivibrio fischeri, lytechinus variegatus, daphnia magna, skeletonema costatum and vicia faba were analyzed by assessing different endpoints: biomass growth, peroxidase activity, mitotic index, micronucleus frequency, and lethality i ... | 2013 | 23597676 |
| daphnia magna, a host for evaluation of bacterial virulence. | we show that daphnia magna can be used to assess acute virulence of pathogens relevant to human health, such as pseudomonas aeruginosa or photorhabdus asymbiotica. analysis of bacterial mutants suggests that p. aeruginosa uses similar mechanisms to infect daphnia and other hosts. | 2012 | 22081563 |
| an assessment of the potential of the microbial assay for risk assessment (mara) for ecotoxicological testing. | rapid microscale toxicity tests make it possible to screen large numbers of compounds and greatly simplify toxicity identification evaluation and other effect directed chemical analyses of effluents or environmental samples. tests using vibrio fischeri (such as microtox®) detect toxicants that cause non-specific narcosis, but are insensitive to other important classes of contaminants. the microbial assay for risk assessment (mara) is a 24 h multi-species test that seeks to address this problem b ... | 2010 | 20882341 |
| extinction hazards in experimental daphnia magna populations: effects of genotype diversity and environmental variation. | extinction is ubiquitous in natural systems and the ultimate fate of all biological populations. however, the factors that contribute to population extinction are still poorly understood, particularly genetic diversity and composition. a laboratory experiment was conducted to examine the influences of environmental variation and genotype diversity on persistence in experimental daphnia magna populations. populations were initiated in two blocks with one, two, three, or six randomly selected and ... | 2012 | 23467276 |
| population genetics of duplicated alternatively spliced exons of the dscam gene in daphnia and drosophila. | in insects and crustaceans, the down syndrome cell adhesion molecule (dscam) occurs in many different isoforms. these are produced by mutually exclusive alternative splicing of dozens of tandem duplicated exons coding for parts or whole immunoglobulin (ig) domains of the dscam protein. this diversity plays a role in the development of the nervous system and also in the immune system. structural analysis of the protein suggested candidate epitopes where binding to pathogens could occur. these epi ... | 2011 | 22174757 |
| chronic toxicity of aniline and 2,4-dichlorophenol to daphnia magna straus. | | 2012 | 3345354 |
| acute toxicity of cresols, xylenols, and trimethylphenols to daphnia magna straus 1820. | twenty-four-hour ic50 values (50% immobilization concentration) for phenol, o-cresol, m-cresol, p-cresol, six xylenols, and three trimethylphenols were determined for daphnia magna under static conditions. our results show that cresols are more toxic than phenol, that xylenols do not exhibit significantly higher toxicity than cresols, and that trimethylphenols are less toxic than cresols. thus, no direct relationship can be found between the number and position of methyl groups on the phenol nuc ... | 2011 | 3238416 |
| efficacy of fungal decolorization of a mixture of dyes belonging to different classes. | dyes are the most difficult constituents to remove by conventional biological wastewater treatment. colored wastewater is mainly eliminated by physical and chemical procedures, which are very expensive and have drawbacks. therefore, the advantage of using biological processes, such as the biotransformation of dyes, is that they may lead to complete mineralization or formation of less toxic products. to prove the possibility of using fungal processes for decolorization and other applications, the ... | 2015 | 26273256 |
| effectiveness of dyes removal by mixed fungal cultures and toxicity of their metabolites. | decolorization of brilliant green (0.06 g/l), evans blue (0.15 g/l), and their mixture (total concentration 0.08 g/l, proportion 1:1 w/w) by fungi was studied. fungal strains [pleurotus ostreatus (bwph), gloeophyllum odoratum (dca), and fusarium oxysporum (g1)] were used separately and as a mixture of them. zootoxicity (daphnia magna) and phytotoxicity (lemna minor) changes were estimated after the end of experiment. mixtures of fungal strains were less effective in decolorization process than t ... | 2013 | 23687394 |
| proteomic analysis of daphnia magna hints at molecular pathways involved in defensive plastic responses. | phenotypic plasticity in defensive traits occurs in many species when facing heterogeneous predator regimes. the waterflea daphnia is well-known for showing a variety of these so called inducible defences. however, molecular mechanisms underlying this plasticity are poorly understood so far. we performed proteomic analysis on daphnia magna exposed to chemical cues of the predator triops cancriformis. d. magna develops an array of morphological changes in the presence of triops including changes ... | 2014 | 24762235 |
| acute toxicity and qsar of chlorophenols on daphnia magna. | | 2009 | 3768559 |
| biotic interactions govern genetic adaptation to toxicants. | the genetic recovery of resistant populations released from pesticide exposure is accelerated by the presence of environmental stressors. by contrast, the relevance of environmental stressors for the spread of resistance during pesticide exposure has not been studied. moreover, the consequences of interactions between different stressors have not been considered. here we show that stress through intraspecific competition accelerates microevolution, because it enhances fitness differences between ... | 0 | 25833856 |
| relevance of the bioavailable fraction of ddt and its metabolites in freshwater sediment toxicity: new insight into the mode of action of these chemicals on dictyostelium discoideum. | in this work, the toxicity of lake sediments contaminated with ddt and its metabolites ddd and dde (collectively, ddx) was evaluated with widely used toxicity tests (i.e., vibrio fischeri, daphnia magna, pseudokirchneriella subcapitata, and lumbriculus variegatus) and with the social amoeba dictyostelium discoideum, a model organism that is also suitable for studying pollutant-induced alterations at the molecular and cellular levels. although the ddx concentration in the sediments was high (732. ... | 2016 | 27340883 |
| ecotoxicological survey of mnei and y65r-mnei proteins as new potential high-intensity sweeteners. | low-calorie sweeteners are widespread. they are routinely introduced into commonly consumed food such as diet sodas, cereals, and sugar-free desserts. recent data revealed the presence in considerable quantities of some of these artificial sweeteners in water samples qualifying them as a class of potential new emerging contaminants. this study aimed at evaluating the ecotoxicity profile of mnei and y65r-mnei, two engineered products derived from the natural protein monellin, employing representa ... | 2017 | 28251536 |
| effects of ammonia and density on filtering of commensal and pathogenic escherichia coli by the cladoceran daphnia magna. | grazing by cladocerans can reduce the survival of enteric bacteria associated with fecal pollution. this study examined the potential of daphnia magna to filter commensal and pathogenic escherichia coli of human origin. grazing on commensal and pathogenic bacteria was comparable, but slightly greater at 20 compared to 15 and 25°c. filtering activity was strongly dependent on d. magna and e. coli densities at environmentally relevant bacterial concentrations. maximum feeding rates were >10(7) cel ... | 2016 | 27817111 |
| decolorization of acid and basic dyes: understanding the metabolic degradation and cell-induced adsorption/precipitation by escherichia coli. | escherichia coli strain dh5α was successfully employed in the decolorization of commercial anthraquinone and azo dyes, belonging to the general classes of acid or basic dyes. the bacteria showed an aptitude to survive at different ph values on any dye solution tested, and a rapid decolorization was obtained under aerobic conditions for the whole collection of dyes. a deep investigation about the mode of action of e. coli was carried out to demonstrate that dye decolorization mainly occurred via ... | 2015 | 26062529 |
| eco-genotoxicity of six anticancer drugs using comet assay in daphnids. | the eco-genotoxicity of six anti-neoplastic drugs, 5-fluorouracil, capecitabine, cisplatin, doxorubicin, etoposide, and imatinib, belonging to five classes of anatomical therapeutic classification (atc), was studied applying the in vivo comet assay on cells from whole organisms of daphnia magna and ceriodaphnia dubia. for the first time, this test was performed in c. dubia. in addition, to have a wider genotoxic/mutagenic profile of the anticancer drugs selected, sos chromotest and salmonella mu ... | 2015 | 25638790 |
| high concentrations of protein test substances may have non-toxic effects on daphnia magna: implications for regulatory study designs and ecological risk assessments for gm crops. | laboratory testing for possible adverse effects of insecticidal proteins on non-target organisms (ntos) is an important part of many ecological risk assessments for regulatory decision-making about the cultivation of insect-resistant genetically modified (irgm) crops. to increase confidence in the risk assessments, regulatory guidelines for effects testing specify that representative surrogate species for ntos are exposed to concentrations of insecticidal proteins that are in excess of worst-cas ... | 2014 | 25523175 |
| novel composite plastics containing silver(i) acylpyrazolonato additives display potent antimicrobial activity by contact. | new silver(i) acylpyrazolonato derivatives displaying a mononuclear, polynuclear, or ionic nature, as a function of the ancillary azole ligands used in the synthesis, have been fully characterized by thermal analysis, solution nmr spectroscopy, solid-state ir and nmr spectroscopies, and x-ray diffraction techniques. these derivatives have been embedded in polyethylene (pe) matrix, and the antimicrobial activity of the composite materials has been tested against three bacterial strains (e. coli, ... | 2015 | 25358838 |
| tertiary treatment for wastewater reuse based on the daphnia magna filtration - comparison with conventional tertiary treatments. | tertiary treatments are required to permit safe reuse of wastewater. the performance of a new biological tertiary treatment based on the filtration by a population of daphnia magna was studied and compared with the performance of other conventional tertiary treatments such as coagulation-flocculation, settling tank, disc filtration, sand filtering and ultraviolet (uv) light. the analysis was based on the efficiency in the particle removal and escherichia coli inactivation. the daphnia magna trea ... | 2014 | 25116502 |
| peracetic acid for secondary effluent disinfection: a comprehensive performance assessment. | the paper is a review of previous research on secondary effluent disinfection by peracetic acid (paa) integrated with new data about the effect of a preliminary flash-mixing step. the process was studied at bench and pilot scale to assess its performance for discharge in surface water and agricultural reuse (target microorganisms: escherichia coli and faecal coliform bacteria). the purposes of the research were: (1) determining paa decay and disinfection kinetics as a function of operating param ... | 2013 | 24355852 |
| assessment of sediment quality and pore water ecotoxicity in kebir rhumel basin (ne-algeria): a combined approach. | the objectives of this study are to use different approaches to assess the current pollution status in the wadis of the kebir rhumel basin. first, sediment trace metal contents were measured by flame atomic absorption spectroscopy. then, sediment quality was assessed on the basis of contamination assessment indexes such as: geoaccumulation index (igeo), contamination factor (c(f)), contamination degree (c(d)), sediment pollution index (spi) and seq guidelines (consensus sediment quality guidelin ... | 2012 | 22233919 |
| low-dose effects: nonmonotonic responses for the toxicity of a bacillus thuringiensis biocide to daphnia magna. | currently, there is a trend toward an increasing use of biopesticides assumed to be environmentally friendly, such as bacillus thuringiensis (bt). studies of the bt toxicity to nontarget organisms have reported low effects at high exposure levels, which is interpreted as indicating negligible risk to nontarget organisms. we investigated the response of the nontarget organism daphnia magna to waterborne dipel es, a globally used bt formulation. neonates and adults were exposed for 48 h to a wide ... | 2017 | 28001053 |
| interactions between bt crops and aquatic ecosystems: a review. | the term bt crops collectively refers to crops that have been genetically modified to include a gene (or genes) sourced from bacillus thuringiensis (bt) bacteria. these genes confer the ability to produce proteins toxic to certain insect pests. the interaction between bt crops and adjacent aquatic ecosystems has received limited attention in research and risk assessment, despite the fact that some bt crops have been in commercial use for 20 yr. reports of effects on aquatic organisms such as dap ... | 2016 | 27530353 |
| daphnia magna negatively affected by chronic exposure to purified cry-toxins. | cry-toxin genes originating from bacillus thuringiensis are inserted into genetically modified (gm) plants, often called bt-plants, to provide insect resistance to pests. significant amounts of bt-plant residues, and thus cry-toxins, will be shed to soil and aquatic environments. we exposed daphnia magna to purified cry1ab and cry2aa toxins for the full life-span of the animals. we used single toxins in different doses and combinations of toxins and roundup(®), another potential stressor on the ... | 2016 | 26993955 |
| chronic responses of daphnia magna under dietary exposure to leaves of a transgenic (event mon810) bt-maize hybrid and its conventional near-isoline. | insect resistance is the second most common trait globally in cultivated genetically modified (gm) plants. resistance is usually obtained by introducing into the plant's genome genes from the bacterium bacillus thuringiensis (bt) coding for insecticidal proteins (cry proteins or toxins) that target insect pests. the aim of this study was to examine the hypothesis that a chronic, high-dose dietary exposure to leaves of a bt-maize hybrid (gm event mon810, expressing a transgenic or recombinant cry ... | 2015 | 26262442 |
| transgenic bacillus thuringiensis (bt) rice is safer to aquatic ecosystems than its non-transgenic counterpart. | rice lines genetically modified with the crystal toxin genes from bacillus thuringiensis (bt) have experienced rapid development, with biosafety certificates for two bt rice lines issued in 2009. there has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. some studies confirmed that bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in bt ric ... | 2014 | 25105299 |
| daphnia predation on the amphibian chytrid fungus and its impacts on disease risk in tadpoles. | direct predation upon parasites has the potential to reduce infection in host populations. for example, the fungal parasite of amphibians, batrachochytrium dendrobatidis (bd), is commonly transmitted through a free-swimming zoospore stage that may be vulnerable to predation. potential predators of bd include freshwater zooplankton that graze on organisms in the water column. we tested the ability of two species of freshwater crustacean (daphnia magna and d. dentifera) to consume bd and to reduce ... | 2013 | 24324864 |
| chiral triazole fungicide difenoconazole: absolute stereochemistry, stereoselective bioactivity, aquatic toxicity, and environmental behavior in vegetables and soil. | in this study, the systemic assessments of the stereoisomers of triazole fungicide difenoconazole are reported for the first time, including absolute stereochemistry, stereoselective bioactivity toward pathogens (alternaria sonali, fulvia fulva, botrytis cinerea, and rhizoctonia solani), and toxicity toward aquatic organisms (scenedesmus obliquus, daphnia magna, and danio rerio). moreover, the stereoselective degradation of difenoconazole in vegetables (cucumber, cucumis sativus and tomato, lyco ... | 2013 | 23451708 |
| particle size, surface charge and concentration dependent ecotoxicity of three organo-coated silver nanoparticles: comparison between general linear model-predicted and observed toxicity. | mechanism underlying nanotoxicity has remained elusive. hence, efforts to understand whether nanoparticle properties might explain its toxicity are ongoing. considering three different types of organo-coated silver nanoparticles (agnps): citrate-coated agnp, polyvinylpyrrolidone-coated agnp, and branched polyethyleneimine-coated agnp, with different surface charge scenarios and core particle sizes, herein we systematically evaluate the potential role of particle size and surface charge on the to ... | 2014 | 24091120 |
| bioactivity, toxicity and dissipation of hexaconazole enantiomers. | in this study, the bioactivity, acute toxicity and dissipation in vegetables of the individual enantiomers of the fungicide hexaconazole had been investigated. the optical pure single enantiomers were prepared and the bioactivity of (+)-, (-)- and rac-hexaconazole was tested using four target fungi including colletotrichum gloeosporioides penz, alternaria solani, alternaria mali roberts and monilinia fructicola. the results showed (-)-hexaconazole was always more active than (+)-hexaconazole wit ... | 2013 | 24206830 |
| use of ecotoxicity test and ecoscores to improve the management of polluted soils: case of a secondary lead smelter plant. | with the rise of sustainable development, rehabilitation of brownfield sites located in urban areas has become a major concern. management of contaminated soils in relation with environmental and sanitary risk concerns is therefore a strong aim needing the development of both useful tools for risk assessment and sustainable remediation techniques. for soils polluted by metals and metalloids (mte), the criteria for landfilling are currently not based on ecotoxicological tests but on total mte con ... | 2013 | 23328625 |
| whole-cell bacterial biosensors for rapid and effective monitoring of heavy metals and inorganic pollutants in wastewater. | the increasing number of potentially harmful pollutants in the wastewater effluent discharge necessitates the need for the development of fast and cost effective analytical techniques for extensive monitoring programmes to assess the effectiveness of the treatment process. this study compared the use of bacterial biosensors to the conventional daphnia magna assay, chemical oxygen demand (cod) and biochemical oxygen demand (bod) tests as well as chemical analysis, for monitoring the toxicity of w ... | 2011 | 21904738 |
| the influence of bacteria-dominated diets on daphnia magna somatic growth, reproduction, and lipid composition. | we explored how dietary bacteria affect the life history traits and biochemical composition of daphnia magna, using three bacteria taxa with very different lipid composition. our objectives were to (1) examine whether and how bacteria-dominated diets affect daphnia survival, growth, and fecundity, (2) see whether bacteria-specific fatty acid (fa) biomarkers accrued in daphnia lipids, and (3) explore the quantitative relationship between bacteria availability in daphnia diets and the amounts of b ... | 2012 | 22564190 |
| expression of parasite virulence at different host population densities under natural conditions. | it has recently been suggested that the expression of parasite virulence depends on host population density, such that infected hosts have a higher sensitivity to density, and thus reach their carrying capacity earlier than uninfected hosts. in this scenario, parasite-induced reduction in fitness (i.e., virulence) increases with host density. we tested this hypothesis experimentally, using outdoor mesocosm populations of daphnia magna infected by the microsporidian octosporea bayeri. contrary to ... | 2009 | 19219457 |
| different mechanisms of transmission of the microsporidium octosporea bayeri: a cocktail of solutions for the problem of parasite permanence. | periods of low host density impose a constraint on parasites with direct transmission, challenging their permanence in the system. the microsporidium octosporea bayeri faces such constraint in a metapopulation of its host, the cladoceran daphnia magna, where ponds frequently lose their host population due to ponds drying out in summer and freezing in winter. we conducted experiments aimed to investigate the mechanisms of transmission of o. bayeri, and discuss how these mechanisms could contribut ... | 2005 | 15991493 |
| mixed inoculations of a microsporidian parasite with horizontal and vertical infections. | mixed infections, where more than one parasite genotype is present in a single host, have been suggested to be an important factor in host-parasite interactions. as the host represents a limited resource, co-infecting parasite genotypes are expected to be under resource competition. competition will not only modify the survival of the co-infecting genotypes, but is also likely to affect total within-host parasite growth as well as host survival and reproduction. we measured parasite infectivity ... | 2005 | 15742220 |
| role of water fleas (daphnia magna) in the accumulation of avian influenza viruses from the surrounding water. | to determine the role of water fleas in accumulating avian influenza viruses (aiv) from the surrounding water and to estimate their role as a vector of aiv. | 2012 | 22269863 |
| wrecking the curve: altered functional response of tetragoneuria (odonata: corduliidae) naiads infected with metacercariae of haematoloechus floedae. | the ubiquity of host-parasite interactions and their potential for substantial representation, in terms of overall biomass, within ecosystems suggests that parasites have the capacity to influence energy flow within an ecosystem. while the influence of certain parasites on prey behavior has been well-documented, parasites could also exert an influence on ecosystem dynamics by influencing predator feeding behavior. the functional response of tetragoneuria naiads was characterized by presenting na ... | 2017 | 28118094 |
| quantitative pcr to detect, discriminate and quantify intracellular parasites in their host: an example from three microsporidians in daphnia. | reliable detection, discrimination and quantification of parasites are important for host-parasite studies and diagnostics. microsporidial infections are problematic in this respect. their discrimination and quantification using light microscopy is difficult because spores are the only light microscopically visible form of the parasite and they offer few distinct characters. we developed a quantitative pcr (qpcr) assay based on sybr green chemistry to quantify the microsporidia glugoides intesti ... | 2006 | 16563203 |
| apparent seasonality of parasite dynamics: analysis of cyclic prevalence patterns. | seasonal disease dynamics are common in nature, but their causes are often unknown. our case study provides insight into the cyclic prevalence pattern of the horizontally and vertically transmitted microsporidium octosporea bayeri in its daphnia magna host. data from several populations over a four year period revealed a regular prevalence increase during summer and a decrease over winter when hosts underwent diapause. prevalence also decreased after summer diapause indicating that the decline i ... | 2006 | 16555788 |
| transcriptome profiling during a natural host-parasite interaction. | infection outcome in some coevolving host-pathogens is characterised by host-pathogen genetic interactions, where particular host genotypes are susceptible only to a subset of pathogen genotypes. to identify candidate genes responsible for the infection status of the host, we exposed a daphnia magna host genotype to two bacterial strains of pasteuria ramosa, one of which results in infection, while the other does not. at three time points (four, eight and 12 h) post pathogen exposure, we sequenc ... | 2015 | 26311167 |
| host age modulates parasite infectivity, virulence and reproduction. | host age is one of the most striking differences among hosts within most populations, but there is very little data on how age-dependent effects impact ecological and evolutionary dynamics of both the host and the parasite. here, we examined the influence of host age (juveniles, young and old adults) at parasite exposure on host susceptibility, fecundity and survival as well as parasite transmission, using two clones of the water flea daphnia magna and two clones of its bacterial parasite pasteu ... | 2015 | 25661269 |
| octosporea bayeri: fumidil b inhibits vertical transmission in daphnia magna. | microsporidia are a highly successful and ecologically diverse group of parasites, and thus represent interesting model systems for research on host-parasite interactions. however, such research often requires the ability to cure hosts of infections, a difficult task, given the short lifespan of most invertebrates and the efficient vertical transmission of some parasites. to our knowledge, few treatments are available to cure microsporidiosis in invertebrate hosts, and protocols have not yet bee ... | 2005 | 15639141 |
| within-host dynamics of a microsporidium with horizontal and vertical transmission: octosporea bayeri in daphnia magna. | the fresh-water crustacean daphnia magna may acquire an infection with the microsporidium octosporea bayeri either by ingesting spores from the water (horizontally), or directly from its mother (vertically). due to differences in the time and mechanisms of transmission, horizontal and vertical infections may lead to differences in the growth of the parasite within the host. this may influence parasite virulence, transmission to new hosts, and, consequently, epidemiology and evolution. here we de ... | 2004 | 15002901 |
| survival, reproduction, growth, and parasite resistance of aquatic organisms exposed on-site to wastewater treated by advanced treatment processes. | advanced wastewater treatment technologies are generally known to be an effective tool for reducing micropollutant discharge into the aquatic environment. nevertheless, some processes such as ozonation result in stable transformation products with often unknown toxicity. in the present study, whole effluents originating from nine different steps of advanced treatment combinations were compared for their aquatic toxicity. assessed endpoints were survival, growth and reproduction of lumbriculus va ... | 2017 | 28284153 |
| the red queen lives: epistasis between linked resistance loci. | a popular theory explaining the maintenance of genetic recombination (sex) is the red queen theory. this theory revolves around the idea that time-lagged negative frequency-dependent selection by parasites favors rare host genotypes generated through recombination. although the red queen has been studied for decades, one of its key assumptions has remained unsupported. the signature host-parasite specificity underlying the red queen, where infection depends on a match between host and parasite g ... | 2016 | 26763092 |
| infections by pasteuria do not protect its natural host daphnia magna from subsequent infections. | the existence of immunological memory in invertebrates remains a contentious topic. exposure of daphnia magna crustaceans to a noninfectious dose of the bacterium pasteuria ramosa has been reported to reduce the chance of future infection upon exposure to higher doses. using clonal hosts and parasites, we tested whether initial exposure of the host to the parasite (priming), followed by clearing of the parasite with antibiotic, protects the host from a second exposure (challenge). our experiment ... | 2016 | 26709232 |
| genetic architecture of resistance in daphnia hosts against two species of host-specific parasites. | understanding the genetic architecture of host resistance is key for understanding the evolution of host-parasite interactions. evolutionary models often assume simple genetics based on few loci and strong epistasis. it is unknown, however, whether these assumptions apply to natural populations. using a quantitative trait loci (qtl) approach, we explore the genetic architecture of resistance in the crustacean daphnia magna to two of its natural parasites: the horizontally transmitted bacterium p ... | 2015 | 25335558 |
| epidemiology of a daphnia-multiparasite system and its implications for the red queen. | the red queen hypothesis can explain the maintenance of host and parasite diversity. however, the red queen requires genetic specificity for infection risk (i.e., that infection depends on the exact combination of host and parasite genotypes) and strongly virulent effects of infection on host fitness. a european crustacean (daphnia magna)--bacterium (pasteuria ramosa) system typifies such specificity and high virulence. we studied the north american host daphnia dentifera and its natural parasit ... | 2012 | 22761826 |
| starvation reveals the cause of infection-induced castration and gigantism. | parasites often induce life-history changes in their hosts. in many cases, these infection-induced life-history changes are driven by changes in the pattern of energy allocation and utilization within the host. because these processes will affect both host and parasite fitness, it can be challenging to determine who benefits from them. determining the causes and consequences of infection-induced life-history changes requires the ability to experimentally manipulate life history and a framework f ... | 2014 | 25143034 |
| the effects of parasitism and inbreeding on the competitive ability in daphnia magna: evidence for synergistic epistasis. | synergistic epistasis for fitness is often assumed in models of how selection acts on the frequency and distribution of deleterious mutations. evidence for synergistic epistasis would exist if the logarithm of fitness declines more quickly with number of deleterious mutations, than predicted by a linear decline. this can be studied indirectly by quantifying the effect of different levels of inbreeding on fitness. here, six sets (different genetic backgrounds) of three increasingly inbred daphnia ... | 2003 | 14635913 |
| the development of pathogen resistance in daphnia magna: implications for disease spread in age-structured populations. | immunity in vertebrates is well established to develop with time, but the ontogeny of defence in invertebrates is markedly less studied. yet, age-specific capacity for defence against pathogens, coupled with age structure in populations, has widespread implications for disease spread. thus, we sought to determine the susceptibility of hosts of different ages in an experimental invertebrate host-pathogen system. in a series of experiments, we show that the ability of daphnia magna to resist its n ... | 2014 | 25214486 |
| dietary supply with polyunsaturated fatty acids and resulting maternal effects influence host--parasite interactions. | interactions between hosts and parasites can be substantially modulated by host nutrition. polyunsaturated fatty acids (pufas) are essential dietary nutrients; they are indispensable as structural components of cell membranes and as precursors for eicosanoids, signalling molecules which act on reproduction and immunity. here, we explored the potential of dietary pufas to affect the course of parasitic infections using a well-established invertebrate host - parasite system, the freshwater herbivo ... | 2013 | 24175981 |
| effects of juvenile host density and food availability on adult immune response, parasite resistance and virulence in a daphnia-parasite system. | host density can increase infection rates and reduce host fitness as increasing population density enhances the risk of becoming infected either through increased encounter rate or because host condition may decline. conceivably, potential hosts could take high host density as a cue to up-regulate their defence systems. however, as host density usually covaries with food availability, it is difficult to examine the importance of host density in isolation. thus, we performed two full-factorial ex ... | 2014 | 24736707 |
| single-nucleotide polymorphisms of two closely related microsporidian parasites suggest a clonal population expansion after the last glaciation. | the mode of reproduction of microsporidian parasites has remained puzzling since many decades. it is generally accepted that microsporidia are capable of sexual reproduction, and that some species have switched to obligate asexuality, but such process had never been supported with population genetic evidence. we examine the mode of reproduction of hamiltosporidium tvaerminnensis and hamiltosporidium magnivora, two closely related microsporidian parasites of the widespread freshwater crustacean d ... | 2013 | 23163569 |
| host age modulates within-host parasite competition. | in many host populations, one of the most striking differences among hosts is their age. while parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. using two clones of the water flea daphnia magna and two clones of its bacterial parasite pasteuria ramosa, we examined how host age at exposure influences within-host parasite competition and virulence. we found that multiply-exposed hosts we ... | 2015 | 25994010 |
| male-biased sex-ratio distortion caused by octosporea bayeri, a vertically and horizontally-transmitted parasite of daphnia magna. | female-biased sex-ratio distortion is often observed in hosts infected with vertically-transmitted microsporidian parasites. this bias is assumed to benefit the spread of the parasite, because male offspring usually do not transmit the parasite further. the present study reports on sex-ratio distortion in a host-parasite system with both horizontal and vertical parasite transmission: the microsporidium octosporea bayeri and its host, the planktonic cladoceran daphnia magna. in laboratory and fie ... | 2008 | 18190917 |
| the genotype specific competitive ability does not correlate with infection in natural daphnia magna populations. | different evolutionary hypotheses predict a correlation between the fitness of a genotype in the absence of infection and the likelihood to become infected. the cost of resistance hypothesis predicts that resistant genotypes pay a cost of being resistant and are less fit in the absence of parasites. the inbreeding-infection hypothesis predicts that the susceptible individuals are less fit due to inbreeding depression. | 2007 | 18060074 |
| a short term benefit for outcrossing in a daphnia metapopulation in relation to parasitism. | because host-parasite interactions are often specific to the host and parasite genotype, it may be important whether a host reproduces by selfing or outcrossing. the latter is associated with higher genetic diversity among the offspring and may reduce parasite success. here, we test whether outbred offspring of daphnia magna have an advantage over selfed offspring in the presence of a parasite transmitted from mothers to offspring. using outdoor mesocosms, we set up monoclonal and polyclonal hos ... | 2007 | 17456451 |
| expression of parasite genetic variation changes over the course of infection: implications of within-host dynamics for the evolution of virulence. | how infectious disease agents interact with their host changes during the course of infection and can alter the expression of disease-related traits. yet by measuring parasite life-history traits at one or few moments during infection, studies have overlooked the impact of variable parasite growth trajectories on disease evolution. here we show that infection-age-specific estimates of host and parasite fitness components can reveal new insight into the evolution of parasites. we do so by charact ... | 2015 | 25761710 |
| parasitism drives host genome evolution: insights from the pasteuria ramosa-daphnia magna system. | because parasitism is thought to play a major role in shaping host genomes, it has been predicted that genomic regions associated with resistance to parasites should stand out in genome scans, revealing signals of selection above the genomic background. to test whether parasitism is indeed such a major factor in host evolution and to better understand host-parasite interaction at the molecular level, we studied genome-wide polymorphisms in 97 genotypes of the planktonic crustacean daphnia magna ... | 2017 | 28230237 |
| the genetic basis of resistance and matching-allele interactions of a host-parasite system: the daphnia magna-pasteuria ramosa model. | negative frequency-dependent selection (nfds) is an evolutionary mechanism suggested to govern host-parasite coevolution and the maintenance of genetic diversity at host resistance loci, such as the vertebrate mhc and r-genes in plants. matching-allele interactions of hosts and parasites that prevent the emergence of host and parasite genotypes that are universally resistant and infective are a genetic mechanism predicted to underpin nfds. the underlying genetics of matching-allele interactions ... | 2017 | 28222092 |
| evaluation of an eventual ecotoxicity induced by textile effluents using a battery of biotests. | textile industry is considered as one of the important factors of the economic growth in tunisia. however, this prominent role has certainly some drawbacks mainly represented by the huge amounts of textile wastewaters generated that become a real menace to nature. many previous studies showed the purifying potential of some activated sludge and bacteria (pseudomonas putida) to decolourize textile effluents. however, in many cases, decolourization of wastewaters is not necessary associated with d ... | 2015 | 26087930 |
| interactions between environmental stressors: the influence of salinity on host-parasite interactions between daphnia magna and pasteuria ramosa. | interactions between environmental stressors play an important role in shaping the health of an organism. this is particularly true in terms of the prevalence and severity of infectious disease, as stressors in combination will not always act to simply decrease the immune function of a host, but may instead interact to compound or even oppose the influence of parasitism on the health of an organism. here, we explore the impact of environmental stress on host-parasite interactions using the water ... | 2013 | 23001624 |
| gene expression profiling of three different stressors in the water flea daphnia magna. | microarrays are an ideal tool to screen for differences in gene expression of thousands of genes simultaneously. however, often commercial arrays are not available. in this study, we performed microarray analyses to evaluate patterns of gene transcription following exposure to two natural and one anthropogenic stressor. cdna microarrays compiled of three life stage specific and three stressor-specific est libraries, yielding 1734 different est sequences, were used. we exposed juveniles of the wa ... | 2013 | 23564370 |
| sex as a strategy against rapidly evolving parasites. | why is sex ubiquitous when asexual reproduction is much less costly? sex disrupts coadapted gene complexes; it also causes costs associated with mate finding and the production of males who do not themselves bear offspring. theory predicts parasites select for host sex, because genetically variable offspring can escape infection from parasites adapted to infect the previous generations. we examine this using a facultative sexual crustacean, daphnia magna, and its sterilizing bacterial parasite, ... | 2016 | 28003455 |
| the trans-generational impact of population density signals on host-parasite interactions. | the density of a host population is a key parameter underlying disease transmission, but it also has implications for the expression of disease through its effect on host physiology. in response to higher densities, individuals are predicted to either increase their immune investment in response to the elevated risk of parasitism, or conversely to decrease their immune capacity as a consequence of the stress of a crowded environment. however, an individual's health is shaped by many different fa ... | 2016 | 27887563 |
| the cellular immune response of daphnia magna under host-parasite genetic variation and variation in initial dose. | in invertebrate-parasite systems, the likelihood of infection following parasite exposure is often dependent on the specific combination of host and parasite genotypes (termed genetic specificity). genetic specificity can maintain diversity in host and parasite populations and is a major component of the red queen hypothesis. however, invertebrate immune systems are thought to only distinguish between broad classes of parasite. using a natural host-parasite system with a well-established pattern ... | 2012 | 23025616 |
| disentangling the influence of parasite genotype, host genotype and maternal environment on different stages of bacterial infection in daphnia magna. | individuals naturally vary in the severity of infectious disease when exposed to a parasite. dissecting this variation into genetic and environmental components can reveal whether or not this variation depends on the host genotype, parasite genotype or a range of environmental conditions. complicating this task, however, is that the symptoms of disease result from the combined effect of a series of events, from the initial encounter between a host and parasite, through to the activation of the h ... | 2012 | 22593109 |
| growth response of avena sativa in amino-acids-rich soils converted from phenol-contaminated soils by corynebacterium glutamicum. | the biodegradation of phenol in laboratory-contaminated soil was investigated using the gram-positive soil bacterium corynebacterium glutamicum. this study showed that the phenol degradation caused by c. glutamicum was greatly enhanced by the addition of 1% yeast extract. from the toxicity test using daphnia magna, the soil did not exhibit any hazardous effects after the phenol was removed using c. glutamicum. additionally, the treatment of the phenolcontaminated soils with c. glutamicum increas ... | 2012 | 22534303 |
| daphnia magna shows reduced infection upon secondary exposure to a pathogen. | previous pathogen exposure is an important predictor of the probability of becoming infected. this is deeply understood for vertebrate hosts, and increasingly so for invertebrate hosts. here, we test if an initial pathogen exposure changes the infection outcome to a secondary pathogen exposure in the natural host-pathogen system daphnia magna and pasteuria ramosa. hosts were initially exposed to an infective pathogen strain, a non-infective pathogen strain or a control. the same hosts underwent ... | 2012 | 22875818 |
| combined effects of dietary polyunsaturated fatty acids and parasite exposure on eicosanoid-related gene expression in an invertebrate model. | eicosanoids derive from essential polyunsaturated fatty acids (pufa) and play crucial roles in immunity, development, and reproduction. however, potential links between dietary pufa supply and eicosanoid biosynthesis are poorly understood, especially in invertebrates. using daphnia magna and its bacterial parasite pasteuria ramosa as model system, we studied the expression of genes coding for key enzymes in eicosanoid biosynthesis and of genes related to oogenesis in response to dietary arachido ... | 2016 | 27421236 |
| response of vibrio cholerae to low-temperature shifts: cspv regulation of type vi secretion, biofilm formation, and association with zooplankton. | the ability to sense and adapt to temperature fluctuation is critical to the aquatic survival, transmission, and infectivity of vibrio cholerae, the causative agent of the disease cholera. little information is available on the physiological changes that occur when v. cholerae experiences temperature shifts. the genome-wide transcriptional profile of v. cholerae upon a shift in human body temperature (37°c) to lower temperatures, 15°c and 25°c, which mimic those found in the aquatic environment, ... | 2016 | 27208110 |
| a population biology perspective on the stepwise infection process of the bacterial pathogen pasteuria ramosa in daphnia. | the infection process of many diseases can be divided into series of steps, each one required to successfully complete the parasite's life and transmission cycle. this approach often reveals that the complex phenomenon of infection is composed of a series of more simple mechanisms. here we demonstrate that a population biology approach, which takes into consideration the natural genetic and environmental variation at each step, can greatly aid our understanding of the evolutionary processes shap ... | 2016 | 27015951 |