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1.
Sci Total Environ ; 689: 655-661, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31279212

RESUMO

Ostreopsis cf. ovata is a benthic microalga distributed in tropical and temperate regions worldwide which produces palytoxins (PlTXs). Herein, an electrochemical biosensor for the detection of this toxic microalga is described. The detection strategy involves isothermal recombinase polymerase amplification (RPA) of the target using tailed primers and a sandwich hybridisation assay on maleimide-coated magnetic beads immobilised on electrode arrays. The biosensor attained a limit of detection of 9 pg/µL of O. cf. ovata DNA (which corresponds to ~640 cells/L), with no interferences from two non-target Ostreopsis species (O. cf. siamensis and O. fattorussoi). The biosensor was applied to the analysis of planktonic and benthic environmental samples. Electrochemical O. cf. ovata DNA quantifications demonstrated an excellent correlation with other molecular methods (qPCR and colorimetric assays) and allowed the construction of a predictive regression model to estimate O. cf. ovata cell abundances. This new technology offer great potential to improve research, monitoring and management of O. cf. ovata and harmful algal blooms.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Algas/análise , DNA de Protozoário/análise , Dinoflagelados/isolamento & purificação , Técnicas Eletroquímicas/instrumentação , Técnicas Biossensoriais/instrumentação , Proliferação Nociva de Algas
2.
Mol Ecol Resour ; 19(4): 1063-1080, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30740899

RESUMO

We present SymPortal (SymPortal.org), a novel analytical framework and platform for genetically resolving the algal symbionts of reef corals using next-generation sequencing (NGS) data of the ITS2 rDNA. Although the ITS2 marker is widely used to genetically characterize taxa within the family Symbiodiniaceae (formerly the genus Symbiodinium), the multicopy nature of the marker complicates its use. Commonly, the intragenomic diversity resultant from this multicopy nature is collapsed by analytical approaches, thereby focusing on only the most abundant sequences. In contrast, SymPortal employs logic to identify within-sample informative intragenomic sequences, which we have termed 'defining intragenomic variants' (DIVs), to identify ITS2-type profiles representative of putative Symbiodiniaceae taxa. By making use of this intragenomic ITS2 diversity, SymPortal is able to resolve genetic delineations using the ITS2 marker at a level that was previously only possible by using additional genetic markers. We demonstrate this by comparing this novel approach to the most commonly used alternative approach for NGS ITS2 data, the 97% similarity clustering to operational taxonomic units (OTUs). The SymPortal platform accepts NGS raw sequencing data as input to provide an easy-to-use, standardization-enforced, and community-driven framework that integrates with a database to gain resolving power with increased use. We consider that SymPortal, in conjunction with ongoing large-scale sampling and sequencing efforts, should play an instrumental role in making future sampling efforts more comparable and in maximizing their efficacy in working towards the classification of the global Symbiodiniaceae diversity.


Assuntos
Antozoários/parasitologia , Biologia Computacional/métodos , DNA de Protozoário/genética , DNA Espaçador Ribossômico/genética , Dinoflagelados/classificação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Filogenia , Animais , DNA de Protozoário/química , DNA Espaçador Ribossômico/química , Dinoflagelados/genética , Dinoflagelados/isolamento & purificação
3.
ISME J ; 13(6): 1635-1638, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30705413

RESUMO

The establishment of coral microbial communities in early developmental stages is fundamental to coral fitness, but its drivers are largely unknown, particularly for bacteria. Using an in situ reciprocal transplant experiment, we examined the influence of parental, planulation and early recruit environments on the microbiome of brooded offspring in the coral Pocillopora damicornis. 16S rRNA and ITS2 rDNA gene metabarcoding showed that bacterial and microalgal endosymbiont communities varied according to parental and planulation environments, but not with early recruit environment. Only a small number of bacterial strains were shared between offspring and their respective parents, revealing bacterial establishment as largely environmentally driven in very early life stages. Conversely, microalgal communities of recruits were highly similar to those of their respective parents, but also contained additional low abundance strains, suggesting both vertical transmission and novel ('horizontal') acquisition. Altogether, recruits harboured more variable microbiomes compared to their parents, indicating winnowing occurs as corals mature.


Assuntos
Antozoários/crescimento & desenvolvimento , Antozoários/microbiologia , Bactérias/isolamento & purificação , Dinoflagelados/isolamento & purificação , Animais , Antozoários/parasitologia , Antozoários/fisiologia , Bactérias/classificação , Bactérias/genética , Fenômenos Fisiológicos Bacterianos , Dinoflagelados/classificação , Dinoflagelados/genética , Microbiota , Simbiose
4.
Mar Pollut Bull ; 139: 197-204, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30686419

RESUMO

A bloom of putatively non-indigenous species (NIS) Prorocentrum shikokuense was detected for the first time in the Mediterranean Sea at the Brindisi harbor (Southern Adriatic Sea) on September 2016, in the context of EU Marine Strategy Framework Directive monitoring in the ports. This species is usually observed in the East China Sea and Japanese and Korean waters. In the Brindisi harbor this dinoflagellate reached the concentration 105 cell/L and represented from 30 to 50% of the total phytoplankton population. Besides this event, Prorocentrum shikokuense has not been found blooming until today in Mediterranean waters. This study suggests the necessity to improve the monitoring surveys in areas that are known vulnerable systems to alien and invasive species, such as ports.


Assuntos
Dinoflagelados/isolamento & purificação , Monitoramento Ambiental/métodos , Espécies Introduzidas/tendências , Fitoplâncton/isolamento & purificação , Água do Mar/química , Eutrofização , Itália , Mar Mediterrâneo
5.
Toxins (Basel) ; 11(1)2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-30646509

RESUMO

Blooms of Dinophysis acuminata occur every year in Galicia (northwest Spain), between spring and autumn. These blooms contaminate shellfish with lipophilic toxins and cause lengthy harvesting bans. They are often followed by short-lived blooms of Dinophysis acuta, associated with northward longshore transport, at the end of the upwelling season. During the summers of 1989 and 1990, dense blooms of D. acuta developed in situ, initially co-occurring with D. acuminata and later with the paralytic shellfish toxin-producer Gymnodinium catenatum. Unexplored data from three cruises carried out before, during, and following autumn blooms (13⁻14, 27⁻28 September and 11⁻12 October) in 1990 showed D. acuta distribution in shelf waters within the 50 m and 130 m isobaths, delimited by the upwelling front. A joint review of monitoring data from Galicia and Portugal provided a mesoscale view of anomalies in SST and other hydroclimatic factors associated with a northward displacement of the center of gravity of D. acuta populations. At the microscale, re-examination of the vertical segregation of cell maxima in the light of current knowledge, improved our understanding of niche differentiation between the two species of Dinophysis. Results here improve local transport models and forecast of Dinophysis events, the main cause of shellfish harvesting bans in the most important mussel production area in Europe.


Assuntos
Bivalves , Dinoflagelados/isolamento & purificação , Ácido Okadáico/análise , Frutos do Mar/análise , Animais , Contagem de Células , Monitoramento Ambiental , Fitoplâncton/isolamento & purificação , Portugal , Estações do Ano , Água do Mar/microbiologia
6.
Toxins (Basel) ; 11(1)2019 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-30621266

RESUMO

Here, we present the interannual distribution of Dinophysis acuminata and Protoceratium reticulatum over a 10-year period in the Reloncaví Fjord, a highly stratified fjord in southern Chile. A realized subniche approach based on the Within Outlying Mean Index (WitOMI) was used to decompose the species' realized niche into realized subniches (found within subsets of environmental conditions). The interannual distribution of both D. acuminata and P. reticulatum summer blooms was strongly influenced by climatological regional events, i.e., El Niño Southern Oscillation (ENSO) and the Southern Annual Mode (SAM). The two species showed distinct niche preferences, with blooms of D. acuminata occurring under La Niña conditions (cold years) and low river streamflow whereas P. reticulatum blooms were observed in years of El Niño conditions and positive SAM phase. The biological constraint exerted on the species was further estimated based on the difference between the existing fundamental subniche and the realized subniche. The observed patterns suggested that D. acuminata was subject to strong biological constraint during the studied period, probably as a result of low cell densities of its putative prey (the mixotrophic ciliate Mesodinium cf. rubrum) usually observed in the studied area.


Assuntos
Dinoflagelados/isolamento & purificação , Estuários , Chile , Proliferação Nociva de Algas , Estações do Ano
7.
Environ Pollut ; 244: 617-626, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30384067

RESUMO

Plastic debris carry fouling a variety of class-size organisms, among them harmful microorganisms that potentially play a role in the dispersal of allochthonous species and toxic compounds with ecological impacts on the marine environment and human health. We analyzed samples of marine plastics floating at the sea surface using a molecular qPCR assay to quantify the attached microalgal taxa, in particular, harmful species. Diatoms were the most abundant group of plastic colonizers with maximum abundance of 8.2 × 104 cells cm-2 of plastics, the maximum abundance of dinoflagellates amounted to 1.1 × 103 cells cm-2 of plastics. The most abundant harmful microalgal taxon was the diatom Pseudo-nitzschia spp., including at least 12 toxic species, and the dinoflagellate Ostreopsis cf. ovata with 6606 and 259 cells cm-2, respectively. The abundance of other harmful microalgal species including the toxic allochthonous dinoflagellate Alexandrium pacificum ranged from 1 to 73 cells cm-2. In the present study, a direct relationship between the abundance of harmful algal species colonizing the plastic substrates and their toxin production was found. The levels of potential toxins on plastic samples ranged from 101 to 102 ng cm-2, considering the various toxin families produced by the colonized harmful microalgal species. We also measured the rate of adhesion by several target microalgal species. It ranged from 1.8 to 0.3 day-1 demonstrating the capacity of plastic substrate colonizing rapidly by microalgae. The present study reports the first estimates of molecular quantification of microorganisms including toxin producing species that can colonize plastics. Such findings provide important insights for improving the monitoring practice of plastics and illustrate how the epi-plastic community can exacerbate the harmful effects of plastics by dispersal, acting as an alien and toxic species carrier and potentially being ingested through the marine trophic web.


Assuntos
Diatomáceas/crescimento & desenvolvimento , Dinoflagelados/crescimento & desenvolvimento , Monitoramento Ambiental , Toxinas Marinhas/análise , Microalgas/crescimento & desenvolvimento , Plásticos/química , Diatomáceas/isolamento & purificação , Dinoflagelados/isolamento & purificação , Humanos , Microalgas/isolamento & purificação , Resíduos/análise
8.
ISME J ; 13(3): 734-737, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30367123

RESUMO

Syndiniales (Dinophyceae, Alveolata) are a diverse parasitic group common in all marine environments, but their ecological role remains poorly understood. Here we show an unprecedented dominance of a single Syndiniales group I operational taxonomic unit (OTU) across 3000 km of Southern Ocean transects near the sea-ice edge. This super-abundant OTU consistently represented >20%, and in some locations >50%, of eukaryote 18S rDNA sequences. Identical 18S V4 sequences have been isolated from seven Northern Hemisphere locations, and the OTU's putative V9 rDNA sequence was detected at every station of the global Tara Oceans voyage. Although Syndiniales taxa display some host specificity, our identification of candidate Southern Ocean hosts suggests this OTU associates with distinct phyla in different parts of the world. Our results indicate Syndiniales are key players in surface waters near the vast and dynamic sea-ice edge in the world's most biologically productive ocean.


Assuntos
Biodiversidade , Dinoflagelados/crescimento & desenvolvimento , Camada de Gelo/parasitologia , Animais , Dinoflagelados/classificação , Dinoflagelados/genética , Dinoflagelados/isolamento & purificação , Ecologia , Ecossistema , Oceanos e Mares
9.
Environ Monit Assess ; 190(11): 689, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30377842

RESUMO

Microplankton population of Asia's largest coastal lagoon Chilika was studied for five major groups, bacillariophyceae, cyanophyceae, chlorophyceae, dinophyceae, rotifera, and tintinninae. The study reported presence of 233 species of microplankton whose average annual abundance was 1631 cells/l. The physicochemical parameters contributing to the spatio-temporal fluctuations in microplankton diversity, abundance, and community structure were identified as salinity, pH, DO, nitrate, and silicate. Salinity, transparency, depth, and silicate most explained the abundance of bacillariophyceae; nitrate, pH, and DO influenced cyanophyceae; salinity, transparency, and chlorophyll concentration influenced chlorophyceae; salinity, depth, and water temperature influenced dinophyceae; salinity, free CO2, and nitrate-influenced rotifers, whereas salinity, pH, DO, and depth influenced tintinnids. Biotic-abiotic relationships revealed particular preference of environmental conditions at species level in groups like bacillariophyceae, cyanophyceae, and dinophyceae. Although the lagoon is shallow, bacillariophyceae-environment interaction showed depth can be a critical factor for species like Aulocoseira sp., Amphipleura sp., and Rhophalodia sp. Species of dinoflagellates like Dinophysis caudata, Noctiluca scintillans, and Protoperidinium proliferated in lower level of silicate. Unlike other cyanophyceae species Streptococcus sp., Chroococcus sp., Diplococcus sp., Aphanocapsa sp., and Gloeocapsa sp. were negatively influenced by nitrate concentration. The study provides better scope for ecological management of the lagoon with respect to conserving biodiversity and hydrological quality of the ecosystem.


Assuntos
Cianobactérias/isolamento & purificação , Diatomáceas/isolamento & purificação , Dinoflagelados/isolamento & purificação , Monitoramento Ambiental/métodos , Plâncton/classificação , Rotíferos/isolamento & purificação , Animais , Biodiversidade , Clorofila/análise , Ecossistema , Índia , Nitratos/análise , Salinidade , Estações do Ano , Temperatura Ambiente
10.
Toxins (Basel) ; 10(10)2018 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-30274219

RESUMO

Diarrhetic shellfish toxins produced by the dinoflagellate genus Dinophysis are a major problem for the shellfish industry worldwide. Separate species of the genus have been associated with the production of different analogues of the okadaic acid group of toxins. To evaluate the spatial and temporal variability of Dinophysis species and toxins in the important shellfish-harvesting region of the Scottish west coast, we analysed data collected from 1996 to 2017 in two contrasting locations: Loch Ewe and the Clyde Sea. Seasonal studies were also undertaken, in Loch Ewe in both 2001 and 2002, and in the Clyde in 2015. Dinophysis acuminata was present throughout the growing season during every year of the study, with blooms typically occurring between May and September at both locations. The appearance of D. acuta was interannually sporadic and, when present, was most abundant in the late summer and autumn. The Clyde field study in 2015 indicated the importance of a temperature front in the formation of a D. acuta bloom. A shift in toxin profiles of common mussels (Mytilus edulis) tested during regulatory monitoring was evident, with a proportional decrease in okadaic acid (OA) and dinophysistoxin-1 (DTX1) and an increase in dinophysistoxin-2 (DTX2) occurring when D. acuta became dominant. Routine enumeration of Dinophysis to species level could provide early warning of potential contamination of shellfish with DTX2 and thus determine the choice of the most suitable kit for effective end-product testing.


Assuntos
Bivalves/química , Dinoflagelados/isolamento & purificação , Toxinas Marinhas/análise , Ácido Okadáico/análise , Piranos/análise , Poluentes da Água/análise , Animais , Monitoramento Ambiental , Contaminação de Alimentos/análise , Escócia , Alimentos Marinhos/análise , Intoxicação por Frutos do Mar
12.
Toxins (Basel) ; 10(6)2018 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-29882830

RESUMO

Dinophysis spp. are a major source of diarrheic toxins to marine food webs, especially during blooms. This study documented the occurrence, in late May 2016, of a massive toxic bloom of the Dinophysis acuminata complex along the southern coast of Brazil, associated with an episode of marked salinity stratification. The study tracked the daily vertical distribution of Dinophysis spp. cells and their ciliate prey, Mesodinium cf. rubrum, and quantified the amount of lipophilic toxins present in seston and accumulated by various marine organisms in the food web. The abundance of the D. acuminata complex reached 43 × 104 cells·L−1 at 1.0 m depth at the peak of the bloom. Maximum cell densities of cryptophyceans and M. cf. rubrum (>500 × 104 and 18 × 104 cell·L−1, respectively) were recorded on the first day of sampling, one week before the peak in abundance of the D. acuminata complex. The diarrheic toxin okadaic acid (OA) was the only toxin detected during the bloom, attaining unprecedented, high concentrations of up to 829 µg·L−1 in seston, and 143 ± 93 pg·cell−1 in individually picked cells of the D. acuminata complex. Suspension-feeders such as the mussel, Perna perna, and barnacle, Megabalanus tintinnabulum, accumulated maximum OA levels (up to 578.4 and 21.9 µg total OA·Kg−1, respectively) during early bloom stages, whereas predators and detritivores such as Caprellidae amphipods (154.6 µg·Kg−1), Stramonita haemastoma gastropods (111.6 µg·Kg−1), Pilumnus spinosissimus crabs (33.4 µg·Kg−1) and a commercially important species of shrimp, Xiphopenaeus kroyeri (7.2 µg·Kg−1), only incorporated OA from mid- to late bloom stages. Conjugated forms of OA were dominant (>70%) in most organisms, except in blenny fish, Hypleurochilus fissicornis, and polychaetes, Pseudonereis palpata (up to 59.3 and 164.6 µg total OA·Kg−1, respectively), which contained mostly free-OA throughout the bloom. Although algal toxins are only regulated in bivalves during toxic blooms in most countries, including Brazil, this study indicates that human seafood consumers might be exposed to moderate toxin levels from a variety of other vectors during intense toxic outbreaks.


Assuntos
Dinoflagelados/isolamento & purificação , Cadeia Alimentar , Toxinas Marinhas/análise , Poluentes da Água/análise , Animais , Brasil , Contagem de Colônia Microbiana , Monitoramento Ambiental , Peixes , Proliferação Nociva de Algas , Invertebrados , Intoxicação por Frutos do Mar
13.
Protist ; 169(3): 333-350, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29864699

RESUMO

This study describes a novel species of Haplozoon, H. ezoense n. sp., a dinoflagellate parasite isolated from the intestines of Praxillella pacifica (Polychaeta). Trophonts (feeding stages) of H. ezoense n. sp. were isolated and studied with scanning and transmission electron microscopy, and molecular phylogenetic analyses was performed using 18S rDNA and 28S rDNA. Trophonts had an average length of 120µm, and were linear, forming a single longitudinal row comprising a trophocyte with a stylet, an average of 14 gonocytes (width=10µm), and bulbous cells that we concluded were likely sporocytes. The surface of H. ezoense n. sp. was covered with projections of the amphiesma. Sections viewed under TEM revealed multiple triple membrane-bound organelles reminiscent of relic non-photosynthetic plastids within the gonocytes. Haplozoon ezoense n. sp., H. praxillellae, and H. axiothellae formed a well-supported clade in the 18S rDNA datasets. The sequences of H. ezoense n. sp. differed from H. praxillellae, a species of Haplozoon isolated from the same host species in the Northeast Pacific, at 88/1,748 bases; and 155/1,752 bases from H. axiothellae. Concatenated 18S rDNA and 28S rDNA datasets were unable to resolve the deeper relationships of Haplozoon in the context of dinoflagellates.


Assuntos
Dinoflagelados/classificação , Dinoflagelados/isolamento & purificação , Filogenia , Plastídeos/ultraestrutura , Animais , Análise por Conglomerados , DNA de Protozoário/química , DNA de Protozoário/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dinoflagelados/genética , Dinoflagelados/ultraestrutura , Trato Gastrointestinal/parasitologia , Estudos Longitudinais , Microscopia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Poliquetos/parasitologia , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Análise de Sequência de DNA
14.
Dis Aquat Organ ; 129(1): 41-51, 2018 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-29916391

RESUMO

Amyloodinium ocellatum, the causative agent of amyloodiniosis (marine velvet, velvet disease), affects marine and brackish fish in various warm and temperate habitats. We recorded disease outbreaks with high morbidity and mortality rates in marine-cultured European seabass Dicentrarchus labrax fry at 2 locations in northwest Egypt. The sudden outbreak, high morbidity and mortality rates, and skin lesions with a velvety appearance in affected fish all indicated A. ocellatum infection. This was further confirmed by microscopic findings of the parasitic stage (trophonts) in skin and gill smears. While ecological factors including water temperature and salinity were all amenable to parasite establishment and propagation, mortality rates differed between the 2 farms, with rates of mortality well correlated with prevalence and intensity of A. ocellatum infections. Characterization by PCR targeting rDNA gene fragments and subsequent DNA sequencing and phylogenetic analysis further confirmed the molecular identity of the A. ocellatum isolate, which was genetically similar to isolates from other geographical locations. Finally, an improved treatment method using dual hyposalination and copper sulfate exposure to increase the efficiency and decrease the toxicity of copper sulfate was tested. The gradual reduction in water salinity coupled with copper sulfate treatment was more efficient at controlling the disease than only applying copper sulfate. To our knowledge, this is the first parasitological and molecular characterization of A. ocellatum in marine cultures in Egypt. The high molecular identity and close phylogenetic relationship further confirmed the monophyletic nature of A. ocellatum isolates.


Assuntos
Aquicultura , Bass/parasitologia , Dinoflagelados/isolamento & purificação , Ectoparasitoses/veterinária , Doenças dos Peixes/parasitologia , Infecções Protozoárias em Animais/parasitologia , Animais , Sulfato de Cobre/uso terapêutico , Dinoflagelados/genética , Surtos de Doenças , Ectoparasitoses/parasitologia , Filogenia , Salinidade , Água/química
15.
Lab Chip ; 18(16): 2369-2377, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-29923578

RESUMO

In this study, a plastic microdevice based on loop-mediated isothermal amplification (LAMP) was fabricated for the amplification and on-chip fluorescence detection of multiple pathogens. Papers infused with LAMP reagents and specific primers were embedded inside the multiple reaction chambers of the microdevice. A solution containing the target pathogens was injected into the sample chamber, located in the center of the microdevice, and evenly distributed to the reaction chambers simultaneously via centrifugal force. For detection, fisetin, a plant-derived fluorophore, was used as the DNA-intercalating dye. Purified DNAs of Escherichia coli O157:H7 (E. coli O157:H7), Salmonella spp., Staphylococcus aureus (S. aureus), and Cochlodinium polykrikoides were successfully amplified and directly detected on the microdevice, where as low as 0.13 and 0.12 ng µL-1 of the DNA of E. coli O157:H7 and S. aureus, respectively, were identified. In addition, the potential of this microdevice for point-of-care testing was further examined by incorporating on-chip sample purification module and testing using a real sample - milk spiked with Salmonella spp. The thermally lysed milk sample was filtered using polydopamine-coated paper embedded inside a sample chamber and seamlessly transported into the reaction chambers by centrifugal force for subsequent LAMP followed by direct on-chip detection inside the reaction chambers in which fisetin-soaked papers were embedded. The limit of detection for Salmonella spp. was determined to be approximately 1.7 × 102 CFU mL-1 using the microdevice. This microdevice is safe, easy to use, selective, and sensitive enough for point-of-care testing to identify foodborne pathogens as well as environmentally harmful microorganisms.


Assuntos
Microbiologia de Alimentos , Microtecnologia/instrumentação , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Temperatura Ambiente , Dinoflagelados/genética , Dinoflagelados/isolamento & purificação , Escherichia coli O157/genética , Escherichia coli O157/isolamento & purificação , Química Verde , Limite de Detecção , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Fatores de Tempo
16.
Acta pediatr. esp ; 76(5/6): 68-71, mayo-jun. 2018. ilus, graf
Artigo em Espanhol | IBECS | ID: ibc-177400

RESUMO

En este artículo se describen las características del organismo productor de la ciguatera, su agente tóxico y su distribución en el mundo. Se comentan los síntomas de la enfermedad y los posibles tratamientos. Se incide en el hecho de que es una enfermedad rara en nuestro medio, pero se empieza a generalizar debido a los viajes internacionales a países endémicos, el comercio internacional e incluso el cambio climático


It describes the characteristics of the organism producing the ciguatera, the toxic and its distribution in the world. Symptoms of the disease and possible treatments are discussed. It is affected by the fact that it is a rare disease in our environment but is beginning to generalize due to international travel to endemic countries, international trade and even climate change


Assuntos
Humanos , Intoxicação por Ciguatera/epidemiologia , Intoxicação por Ciguatera/etiologia , Doenças Raras/epidemiologia , Gastroenteropatias/complicações , Dinoflagelados/isolamento & purificação , Intoxicação por Ciguatera/transmissão , Descontaminação , Antagonistas dos Receptores Histamínicos , Manitol , Intoxicação por Ciguatera/prevenção & controle
17.
Sci Rep ; 8(1): 7011, 2018 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-29725114

RESUMO

The total dinoflagellate cyst community and the cysts of Cochlodinium polykrikoides in the surface sediments of South Sea (Tongyeong coast), South Korea, were analysed using next-generation sequencing (NGS) and morphological approaches. Dinoflagellate cysts can be highly abundant (111-4,087 cysts g-1 dry weight) and have diverse species composition. A total of 35 taxa of dinoflagellate cysts representing 16 genera, 21 species (including four unconfirmed species), and 14 complex species were identified by NGS analysis. Cysts of Scrippsiella spp (mostly Scrippsiella trochoidea) were the most dominant and Polykrikos schwartzii, Pentapharsodinium dalei, Ensiculifera carinata, and Alexandrium catenella/tamarense were common. Thus, a combination of NGS and morphological analysis is effective for studying the cyst communities present in a given environment. Although C. polykrikoides developed massive blooms during 2013-2014, microscopy revealed low density of their cysts, whereas no cysts were detected by NGS. However, the vegetative C. polykrikoides not appeared during 2015-2017 in spite of the observation of C. polykrikoides cysts. This suggests that the C. polykrikoides blooms were not due to development of their cysts but to other factors such as currents transporting them to a marine environment suitable for their growth.


Assuntos
Biodiversidade , Dinoflagelados/classificação , Dinoflagelados/isolamento & purificação , Sedimentos Geológicos/parasitologia , Animais , Dinoflagelados/citologia , Dinoflagelados/genética , Sequenciamento de Nucleotídeos em Larga Escala , República da Coreia
18.
Biotechnol Bioeng ; 115(9): 2194-2204, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29777597

RESUMO

We demonstrate the integration of DNA amplification and detection functionalities developed on a lab-on-a-chip microdevice utilizing solid-phase polymerase chain reaction (SP-PCR) for point-of-need (PON) DNA analyses. First, the polycarbonate microdevice was fabricated by thermal bonding  to contain microchambers as reservoirs for performing SP-PCR. Next, the microchambers were subsequently modified with polyethyleneimine and glutaraldehyde for immobilizing amine-modified forward primers. During SP-PCR, the immobilized forward primers and freely diffusing fluorescence-labeled reverse primers cooperated to generate target amplicons, which remained covalently attached to the microchambers for the fluorescence detection. The SP-PCR microdevice was used for the direct identifications of two widely detected foodborne pathogens, namely Salmonella spp. and Staphylococcus aureus, and an alga causing harmful algal blooms annually in South Korea, Cochlodinium polykrikoides. The SP-PCR microdevice would be versatilely applied in PON testing as a universal platform for the fast identification of foodborne pathogens and environmentally threatening biogenic targets.


Assuntos
Dispositivos Lab-On-A-Chip , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase/métodos , Dinoflagelados/isolamento & purificação , Técnicas Microbiológicas/instrumentação , Técnicas de Diagnóstico Molecular/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito , Reação em Cadeia da Polimerase/instrumentação , Salmonella/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Fatores de Tempo
19.
Harmful Algae ; 75: 105-117, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29778220

RESUMO

Blooms of ichthyotoxic microalgae pose a great challenge to the aquaculture industry world-wide, and there is a need for fast and specific methods for their detection and quantification in monitoring programs. In this study, quantitative real-time PCR (qPCR) assays for the detection and enumeration of three ichthyotoxic flagellates: the dinoflagellate Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup and the two raphidophytes Heterosigma akashiwo (Hada) Hada ex Hara & Chihara and Fibrocapsa japonica Toriumi & Takano were developed. Further, a previously published qPCR assay for the dinoflagellate Karlodinium veneficum (Ballantine) Larsen was used. Monthly samples collected for three years (Aug 2009-Jun 2012) in outer Oslofjorden, Norway were analysed, and the results compared with light microscopy cell counts. The results indicate a higher sensitivity and a lower detection limit (down to 1 cell L-1) for both qPCR assays. Qualitative and semi-quantitative results were further compared with those obtained by environmental 454 high throughput sequencing (HTS, metabarcoding) and scanning electron microscopy (SEM) examination from the same samplings. All four species were detected by qPCR and HTS and/or SEM in outer Oslofjorden (Aug 2009-Jun 2012); Karlodinium veneficum was present year-round, whereas Karenia mikimotoi, Heterosigma akashiwo and Fibrocapsa japonica appeared mainly during the autumn in all three years. This is the first observation of Fibrocapsa japonica in Norwegian coastal waters. This species has previously been recorded off the Swedish west coast and German Bight, which may suggest a northward dispersal.


Assuntos
Dinoflagelados/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Estramenópilas/isolamento & purificação , Proliferação Nociva de Algas , Toxinas Marinhas/análise , Microalgas/isolamento & purificação , Noruega
20.
Harmful Algae ; 75: 45-56, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29778225

RESUMO

Benthic dinoflagellates of the toxigenic genus Coolia Meunier (Dinophyceae) are known to have a global distribution in both tropical and temperate waters. The type species, C. monotis, has been reported from the Mediterranean Sea, the NE Atlantic and from Rhode Island, USA in the NW Atlantic, whereas other species in the genus have been reported from tropical locations. Coolia cells were observed in algal drift samples collected at seven sites in Nova Scotia, Canada. Clonal isolates were established from four of these locations and identified with light and scanning electron microscopy, then confirmed with genetic sequencing to be C. monotis. This is the first record of this species in Nova Scotia. The isolates were established and incubated at 18 °C under a 14:10 L:D photoperiod with an approximate photon flux density of 50-60 µmol m-2 s-1. Growth experiments using an isolate from Johnston Harbour (CMJH) were carried out at temperatures ranging from 5 to 30 °C under the same photoperiod with an approximate photon flux density of 45-50 µmol m-2 s-1. Cells tolerated temperatures from 5 to 25 °C with optimum growth and mucilage aggregate production between 15 and 20 °C. Methanol extracts of this isolate examined by Liquid Chromatography-Mass Spectrometry (LC-MS) did not show the presence of the previously reported cooliatoxin. Toxic effects were assayed using two zebrafish bioassays, the Fish Embryo Toxicity (FET) assay and the General Behaviour and Toxicity (GBT) assay. The results of this study demonstrate a lack of toxicity in C. monotis from Nova Scotia, as has been reported for other genetically-confirmed isolates of this species. Conditions in which cell growth that could potentially degrade water quality and provide substrate and dispersal mechanisms for other harmful microorganisms via mucilage production are indicated.


Assuntos
Dinoflagelados/química , Dinoflagelados/crescimento & desenvolvimento , Animais , Cromatografia Líquida , Dinoflagelados/isolamento & purificação , Embrião não Mamífero/efeitos dos fármacos , Genes de Protozoários , Genes de RNAr , Espectrometria de Massas , Nova Escócia , Testes de Toxicidade , Peixe-Zebra
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