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1.
Harmful Algae ; 84: 27-35, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31128810

RESUMO

Ostreopsis is a toxic benthic dinoflagellate largely distributed worldwide in tropical and temperate areas. In the Mediterranean Sea, periodic summer blooms have been reported and have become a serious concern due to their direct impact on human health and the environment. Current microalgae identification is performed via light microscopy, which is time-consuming and is not able to differentiate among Ostreopsis species. Therefore, there is mature need for rapid, specific and easy-to-use detection tools. In this work, a colorimetric assay exploiting a combination of recombinase polymerase amplification (RPA) and a sandwich hybridisation assay was developed for O. cf. ovata and O. cf. siamensis detection and quantification. The specificity of the system was demonstrated by cross-reactivity experiments and calibration curves were successfully constructed using genomic DNA, achieving limits of detection of 10 and 14 pg/µL for O. cf. ovata and O. cf. siamensis, respectively. The assay was applied to the analysis of planktonic and benthic environmental samples from different sites of the Catalan coast. Species-specific DNA quantifications were in agreement with qPCR analysis, demonstrating the reliability of the colorimetric approach. Significant correlations were also obtained between DNA quantifications and light microscopy counts. The approach may be a valuable tool to provide timely warnings, facilitate monitoring activities or study population dynamics, and paves the way towards the development of in situ tools for the monitoring of harmful algal blooms.


Assuntos
Colorimetria , Dinoflagelados , DNA , Humanos , Mar Mediterrâneo , Reprodutibilidade dos Testes
2.
Anal Chim Acta ; 1039: 140-148, 2018 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-30322545

RESUMO

Karlodinium is a dinoflagellate responsible for fish-killing events worldwide. In Alfacs Bay (NW Mediterranean Sea), the presence of two Karlodinium species (K. veneficum and K. armiger) with different toxicities has been reported. This work presents a method that combines recombinase polymerase amplification (RPA) with an enzyme-linked oligonucleotide assay (ELONA) to identify, discriminate and quantify these two species. The system was characterised using synthetic DNA and genomic DNA, and the specificity was confirmed by cross-reactivity experiments. Calibration curves were constructed using 10-fold dilutions of cultured cells, attaining a limit of detection of around 50,000 cells/L, far below the Karlodinium spp. alert threshold (200,000 cells/L). Finally, the assay was applied to spiked seawater samples, showing an excellent correlation with the spiking levels and light microscopy counts. This approach is more rapid, specific and user-friendly than traditional microscopy techniques, and shows great promise for the surveillance and management of harmful algal blooms.


Assuntos
Ensaio de Imunoadsorção Enzimática , Toxinas Marinhas/análise , Microalgas/química , Oligonucleotídeos/química , Reação em Cadeia da Polimerase em Tempo Real , Oligonucleotídeos/metabolismo
3.
Environ Int ; 119: 570-581, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30172197

RESUMO

Pharmaceuticals (PhACs) and endocrine disrupting compounds (EDCs) are chemicals of emerging concern that can accumulate in seafood sold in markets. These compounds may represent a risk to consumers through effects on the human reproductive system, metabolic disorders, pathogenesis of breast cancer or development of microbial resistance. Measuring their levels in highly consumed seafood is important to assess the potential risks to human health. Besides, the effect of cooking on contaminant levels is relevant to investigate. Therefore, the objectives of this research were to study the presence and levels of PhACs and EDCs in commercially available seafood in the European Union market, to investigate the effect of cooking on contaminant levels, and to evaluate the dietary exposure of humans to these compounds through seafood consumption. A sampling survey of seafood from 11 European countries was undertaken. Twelve highly consumed seafood types were analysed raw and cooked with 3 analytical methods (65 samples, 195 analysis). PhACs were mostly not detectable or below quantification limits in seafood whereas EDCs were a recurrent group of contaminants quantified in the majority of the samples. Besides, cooking by steaming significantly increased their levels in seafood from 2 to 46-fold increase. Based on occurrence and levels, bisphenol A, methylparaben and triclosan were selected for performing a human exposure assessment and health risk characterisation through seafood consumption. The results indicate that the Spanish population has the highest exposure to the selected EDCs through seafood consumption, although the exposure via seafood remained below the current toxicological reference values.


Assuntos
Exposição Dietética/análise , Disruptores Endócrinos/análise , Contaminação de Alimentos/análise , Preparações Farmacêuticas/análise , Alimentos Marinhos/análise , Adolescente , Adulto , Idoso , Compostos Benzidrílicos/análise , Culinária , Europa (Continente) , Humanos , Pessoa de Meia-Idade , Parabenos/análise , Fenóis/análise , Triclosan/análise , Adulto Jovem
4.
Food Chem ; 267: 15-27, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-29934150

RESUMO

The oral bioaccessibility of several essential and toxic elements was investigated in raw and cooked commercially available seafood species from European markets. Bioaccessibility varied between seafood species and elements. Methylmercury bioaccessibility varied between 10 (octopus) and 60% (monkfish). Arsenic (>64%) was the toxic element showing the highest bioaccessibility. Concerning essential elements bioaccessibility in raw seafood, selenium (73%) and iodine (71%) revealed the highest percentages. The bioaccessibility of elements in steamed products increased or decreased according to species. For example, methylmercury bioaccessibility decreased significantly after steaming in all species, while zinc bioaccessibility increased in fish (tuna and plaice) but decreased in molluscs (mussel and octopus). Together with human exposure assessment and risk characterization, this study could contribute to the establishment of new maximum permissible concentrations for toxic elements in seafood by the European food safety authorities, as well as recommended intakes for essential elements.


Assuntos
Contaminação de Alimentos/análise , Compostos Inorgânicos/análise , Alimentos Crus/análise , Alimentos Marinhos/análise , Animais , Arsênico/análise , Culinária , Peixes/metabolismo , Iodo/análise , Compostos de Metilmercúrio/análise , Selênio/análise , Zinco/análise
5.
Food Chem Toxicol ; 118: 490-504, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29787848

RESUMO

Seafood consumption is a major route for human exposure to environmental contaminants of emerging concern (CeCs). However, toxicological information about the presence of CeCs in seafood is still insufficient, especially considering the effect of cooking procedures on contaminant levels. This study is one among a few who evaluated the effect of steaming on the levels of different CeCs (toxic elements, PFCs, PAHs, musk fragrances and UV-filters) in commercially relevant seafood in Europe, and estimate the potential risks associated with its consumption for consumers. In most cases, an increase in contaminant levels was observed after steaming, though varying according to contaminant and seafood species (e.g. iAs, perfluorobutanoate, dibenzo(ah)anthracene in Mytilus edulis, HHCB-Lactone in Solea sp., 2-Ethylhexyl salicylate in Lophius piscatorius). Furthermore, the increase in some CeCs, like Pb, MeHg, iAs, Cd and carcinogenic PAHs, in seafood after steaming reveals that adverse health effects can never be excluded, regardless contaminants concentration. However, the risk of adverse effects can vary. The drastic changes induced by steaming suggest that the effect of cooking should be integrated in food risk assessment, as well as accounted in CeCs regulations and recommendations issued by food safety authorities, in order to avoid over/underestimation of risks for consumer health.


Assuntos
Culinária , Exposição Dietética , Fluorcarbonetos/análise , Contaminação de Alimentos/análise , Metais Pesados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Alimentos Marinhos/análise , Cromatografia Líquida de Alta Pressão , Europa (Continente) , Ácidos Graxos Monoinsaturados/análise , Humanos , Limite de Detecção , Espectrometria de Massas , Medição de Risco , Espectrofotometria Atômica , Raios Ultravioleta
6.
Mar Environ Res ; 133: 6-14, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29174400

RESUMO

Rapid and cost-effective methods to monitor the presence of diarrhetic shellfish poisoning (DSP) toxins in seawater samples in an easy and reliable manner are required to protect human health and avoid economic losses to shellfish industry. Immunoassays for the detection of okadaic acid (OA) and dinophysistoxin-1 and dinophysistoxin-2 are developed by immobilising OA on self-assembled monothiols or dithiols in an ordered and oriented way, providing an effective limit of detection of ∼1 ng OA equiv./mL seawater. The immunoassays are applied to the analysis of the particulate fraction of seawater samples from two Catalan harbours (NW Mediterranean) and samples collected periodically from the Galician Rias (E Atlantic), as well as a reference mussel sample. Results are in agreement with LC-MS/MS and the certified values. OA concentration in seawater correlates with Dinophysis cell abundance, with a 1-2 weeks lag. The immunoassays provide powerful high-throughput analytical methods potentially applicable as alternative monitoring tools.


Assuntos
Monitoramento Ambiental/métodos , Imunoensaio , Toxinas Marinhas/análise , Ácido Okadáico/análise , Animais , Bivalves , Humanos , Água do Mar/química , Frutos do Mar , Intoxicação por Frutos do Mar
7.
Environ Res ; 161: 392-398, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29197280

RESUMO

Cyclic imines constitute a quite recently discovered group of marine biotoxins that act on neural receptors and that bioaccumulate in seafood. They are grouped together due to the imino group functioning as their common pharmacore, responsible for acute neurotoxicity in mice. Cyclic imines (CIs) have not been linked yet to human poisoning and are not regulated in the European Union (EU), although the European Food Safety Authority (EFSA) requires more data to perform conclusive risk assessment for consumers. Several commercial samples of bivalves including raw and processed samples from eight countries (Italy, Portugal, Slovenia, Spain, Ireland, Norway, The Netherlands and Denmark) were obtained over 2 years. Emerging cyclic imine concentrations in all the samples were analysed on a LC-3200QTRAP and LC-HRMS QExactive mass spectrometer. In shellfish, two CIs, pinnatoxin G (PnTX-G) and 13-desmethylspirolide C (SPX-1) were found at low concentrations (0.1-12µg/kg PnTX-G and 26-66µg/kg SPX-1), while gymnodimines and pteriatoxins were not detected in commercial (raw and processed) samples. In summary, SPX-1 (n: 47) and PnTX-G (n: 96) were detected in 9.4% and 4.2% of the samples, respectively, at concentrations higher than the limit of quantification (LOQ), and in 7.3% and 31.2% of the samples at concentrations lower than the LOQ (25µg/kg for SPX-1 and 3µg/kg for PnTX-G), respectively. For the detected cyclic imines, the average exposure and the 95th percentile were calculated. The results obtained indicate that it is unlikely that a potential health risk exists through the seafood diet for CIs in the EU. However, further information about CIs is necessary in order to perform a conclusive risk assessment.


Assuntos
Iminas , Alimentos Marinhos , Animais , Europa (Continente) , Contaminação de Alimentos , Humanos , Iminas/análise , Iminas/toxicidade , Camundongos , Medição de Risco
8.
Mar Drugs ; 15(12)2017 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-29258236

RESUMO

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the detection and quantitation of karlotoxins in the selected reaction monitoring (SRM) mode. This novel method was based upon the analysis of purified karlotoxins (KcTx-1, KmTx-2, 44-oxo-KmTx-2, KmTx-5), one amphidinol (AM-18), and unpurified extracts of bulk cultures of the marine dinoflagellate Karlodinium veneficum strain CCMP2936 from Delaware (Eastern USA), which produces KmTx-1 and KmTx-3. The limit of detection of the SRM method for KmTx-2 was determined as 2.5 ng on-column. Collision induced dissociation (CID) spectra of all putative karlotoxins were recorded to present fragmentation patterns of each compound for their unambiguous identification. Bulk cultures of K. veneficum strain K10 isolated from an embayment of the Ebro Delta, NW Mediterranean, yielded five previously unreported putative karlotoxins with molecular masses 1280, 1298, 1332, 1356, and 1400 Da, and similar fragments to KmTx-5. Analysis of several isolates of K. veneficum from the Ebro Delta revealed small-scale diversity in the karlotoxin spectrum in that one isolate from Fangar Bay produced KmTx-5, whereas the five putative novel karlotoxins were found among several isolates from nearby, but hydrographically distinct Alfacs Bay. Application of this LC-MS/MS method represents an incremental advance in the determination of putative karlotoxins, particularly in the absence of a complete spectrum of purified analytical standards of known specific potency.


Assuntos
Organismos Aquáticos/química , Dinoflagelados/química , Toxinas Marinhas/química , Cromatografia Líquida/métodos , Dinoflagelados/isolamento & purificação , Mar Mediterrâneo , Polienos/química , Piranos/química , Espectrometria de Massas em Tandem/métodos
9.
Front Physiol ; 8: 125, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28316573

RESUMO

Since 2006, the production of Pacific oyster Crassostrea gigas in the Ebro Delta area has dramatically declined from around 800 metric tons (MT) per year to 138 MT in 2011. This decline in production has had a significant socio-economic impact in a region where the shellfish sector is a traditional economic activity for many families. The identified agent responsible for this reduction in C. gigas production was Ostreid Herpesvirus microvar (OsHV-1 µvar), which has been associated with C. gigas spat mortalities in France, and in many other countries. In Spain the episodes of mortality became critical for the regional shellfish production between 2008 until 2014, with mortality percentage up to 100%. In this study, local hatchery C. gigas spat was used as sentinel animals for epidemiological studies and management tests carried out with the aim of reducing oyster mortality in the Ebro Delta area. A production calendar mainly based on water temperature dynamics was designed around an optimal schedule for spat immersion. The immersion calendar included two optimal periods for spat immersion, in summer when temperatures are ≥25°C and at the end of autumn and beginning of winter when they are ≤13°C. Such production planning has reduced mortalities from 80% (in 2014 and previous years) to 2-7.5% in 2015 in cemented oysters. Furthermore, other recommendations related to spat immersion size, culture density and methodology, and cementing calendar, which helped to achieve the results presented, were also recorded and transferred to local producers. This work presents a successfully tested management strategy reducing OsHV-1 µvar impact by designing new field management practices mainly focused on the handling and timing of spat immersion. This approach could be used as a management model in areas presenting similar production practices and environmental characteristics.

10.
Food Chem Toxicol ; 104: 69-78, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28202359

RESUMO

A preliminary assessment of the bioaccessibility of contaminants of emerging concern (CeCs), including perfluorinated compounds (PFCs; i.e. PFOS and PFUnA), brominated flame retardants (BFRs; i.e. BDE47, BDE100, α-HBCD) and pharmaceuticals and personal care products (PPCPs; i.e. venlafaxine, methylparaben and UV-filter OC) was performed in seafood species available in the European markets. Additionally, the effect of steaming on CeCs bioaccessibility was also investigated for the first time. Overall, steaming affected differentially contaminants' concentrations, for instance, decreasing PFOS levels in flounder, but increasing both BDE47 and BDE100. CeCs bioaccessibility varied according to seafood species and contaminant group, i.e. in general, lower bioaccessibility values were obtained for PBDEs (<70%, except for mackerel), while PFCs and PPCPs revealed higher bioaccessibility percentages (between 71 and 95%). The lowest bioaccessibility value was obtained for α-HBCD (mussel; 14%), whereas the highest percentage was observed in venlafaxine (mullet; 95%). Our preliminary study reports also, for the first time, the effects of steaming on CeCs bioaccessibility. In most cases, bioaccessibility was not affected by cooking, however, a decrease was observed in PBDEs and venlafaxine bioaccessibility in steamed mussels and mullet, respectively, thus lowering the potential health risks associated with seafood consumption.


Assuntos
Contaminação de Alimentos/análise , Alimentos Marinhos/análise , Poluentes Químicos da Água/metabolismo , Animais , Culinária , Digestão , Retardadores de Chama/análise , Retardadores de Chama/metabolismo , Retardadores de Chama/toxicidade , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/metabolismo , Éteres Difenil Halogenados/toxicidade , Humanos , Hidrocarbonetos Bromados/análise , Hidrocarbonetos Bromados/metabolismo , Hidrocarbonetos Bromados/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
11.
Harmful Algae ; 55: 191-201, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-28073532

RESUMO

Harmful Algal Bloom (HAB) surveillance is complicated by high diversity of species and associated phycotoxins. Such species-level information on taxonomic affiliations and on cell abundance and toxin content is, however, crucial for effective monitoring, especially of aquaculture and fisheries areas. The aim addressed in this study was to determine putative HAB taxa and related phycotoxins in plankton from aquaculture sites in the Ebro Delta, NW Mediterranean. The comparative geographical distribution of potentially harmful plankton taxa was established by weekly field sampling throughout the water column during late spring-early summer over two years at key stations in Alfacs and Fangar embayments within the Ebro Delta. Core results included not only confirmed identification of HAB taxa that are common for the time period and geographical area, but also provided evidence of potentially new taxa. At least 25 HAB taxa were identified to species level, and an additional six genera were confirmed, by morphological criteria under light microscopy and/or by molecular genetics approaches involving qPCR and next generation DNA pyrosequencing. In particular, new insights were gained by the inclusion of molecular techniques, which focused attention on the HAB genera Alexandrium, Karlodinium, and Pseudo-nitzschia. Noteworthy is the discovery of Azadinium sp., a potentially new HAB species for this area, and Gymnodinium catenatum or Gymnodinium impudicum by means of light microscopy. In addition, significant amounts of the neurotoxin domoic acid (DA) were found for the first time in phytoplankton samples in the Ebro Delta. While the presence of the known DA-producing diatom genus Pseudo-nitzschia was confirmed in corresponding samples, the maximal toxin concentration did not coincide with highest cell abundances of the genus and the responsible species could not be identified. Combined findings of microscopic and molecular detection approaches underline the need for a synoptic strategy for HAB monitoring, which integrates the respective advantages and compensates for limitations of individual methods.


Assuntos
Dinoflagelados/química , Dinoflagelados/fisiologia , Monitoramento Ambiental , Toxinas Marinhas/análise , Diatomáceas/química , Diatomáceas/fisiologia , Dinoflagelados/classificação , Eutrofização , Proliferação Nociva de Algas , Mar Mediterrâneo , Fitoplâncton/química , Fitoplâncton/classificação , Fitoplâncton/fisiologia
12.
Harmful Algae ; 57(Pt A): 98-108, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30170726

RESUMO

The dinoflagellate Ostreopsis cf. ovata proliferates seasonally in the Mediterranean Sea, producing palytoxin-like compounds (ovatoxins) which are considered among the most potent marine toxins. Blooms have been related to several toxic events in which respiratory problems in humans and mortality of benthic marine organisms have been observed. In the coming decades, an increase in temperature and salinity is predicted in the Mediterranean Sea as a consequence of global warming that may provoke alterations in the dynamics of marine microorganisms. In this study, the physiological effects of changes in water temperature and salinity were analyzed, and their interaction through a multi-factorial experiment using two strains of O. cf. ovata in culture that had been isolated from the western Mediterranean Sea. In order to perform an accurate and reliable estimation of cell abundance, hydrochloric acid and sodium-ethylenediaminetetraacetic acid treatments were evaluated for the purpose of disaggregating cell clumps, with the former providing lower counting errors, especially after the stationary phase. Results of the physiological study showed that growth was inhibited at 19°C for all salinities. The highest growth rates were registered at 24°C for both strains (0.48±0.05divday-1), and a significant variability in growth rate was found among salinities at 24°C and 28°C. Two groups were distinguished by cell size in all high temperature conditions and a positive correlation was found between the amount of small cells and growth rate. The concentration of palytoxin-like compounds in the cultures increased with time and significantly higher amounts of toxin were found at 28°C in comparison to 24°C. The results suggest that climate change may not affect intensity of blooms, but their toxicity may be enhanced.

13.
Environ Res ; 143(Pt B): 89-99, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26365038

RESUMO

An expansion of the distribution of Ostreopsis cf. ovata, a dinoflagellate which produces palytoxin-like compounds, has been reported in recent years. Economical and social interests are affected by blooms, as they are responsible for respiratory and skin problems in humans and may cause damage to marine organisms. In order to identify the most influential environmental factors that trigger proliferations of O. cf. ovata in the area of the adjacent shallow rocky coast of the Ebro Delta (NW Mediterranean Sea) a three-year survey was performed on the metaphytic microalgae community growing on the macrophytes Jania rubens and Corallina elongata. Small-size diatoms were more abundant than dinoflagellates; O. cf. ovata was identified as the only species present from the genus. Seawater temperature was the primary driver defining the ecological niche of O. cf. ovata. Freshwater and groundwater fluxes were more pronounced in southern than in northern sites, which may have resulted in a distinct O. cf. ovata spatial distribution, with the highest records of abundance and more frequent blooms in the north. In consequence, negative correlations between the abundance of O. cf. ovata and nitrate concentrations and significant positive correlation with salinity were observed. The temporal pattern of O. cf. ovata dynamics from mid-July to early-November is probably due to the fact that this species is observed only above a certain threshold temperature of seawater. Metaphytic cells of O. cf. ovata were smaller in the northern site than in the south, possibly as a result of an increase in cell division, coinciding with higher abundance, and this could be an indicator of favorable conditions. Toxicity in planktonic cells was negatively correlated with cell abundance in the water column, achieving maximum concentrations of 25pg. PLTX eqcell(-1).


Assuntos
Biota , Dinoflagelados/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Proliferação Nociva de Algas , Água do Mar/química , Acrilamidas/análise , Acrilamidas/toxicidade , Biota/efeitos dos fármacos , Venenos de Cnidários , Diatomáceas/efeitos dos fármacos , Diatomáceas/crescimento & desenvolvimento , Mar Mediterrâneo , Microalgas/efeitos dos fármacos , Microalgas/crescimento & desenvolvimento , Dinâmica Populacional , Análise de Componente Principal , Salinidade , Espanha , Temperatura , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
14.
Environ Res ; 143(Pt B): 72-81, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26411778

RESUMO

The presence of cadmium (Cd), lead (Pb), mercury (THg), methylmercury (MeHg), arsenic (TAs), inorganic arsenic (iAs), cobalt (Co), copper (Cu), zinc (Zn), nickel (Ni), chromium (Cr) and iron (Fe) was investigated in seafood collected from European marine ecosystems subjected to strong anthropogenic pressure, i.e. hotspot areas. Different species (Mytilus galloprovincialis, n=50; Chamelea gallina, n=50; Liza aurata, n=25; Platichthys flesus, n=25; Laminaria digitata, n=15; and Saccharina latissima, n=15) sampled in Tagus estuary, Po delta, Ebro delta, western Scheldt, and in the vicinities of a fish farm area (Solund, Norway), between September and December 2013, were selected to assess metal contamination and potential risks to seafood consumers, as well as to determine the suitability of ecologically distinct organisms as bioindicators in environmental monitoring studies. Species exhibited different elemental profiles, likely as a result of their ecological strategies, metabolism and levels in the environment (i.e. seawater and sediments). Higher levels of Cd (0.15-0.94 mg kg(-1)), Pb (0.37-0.89 mg kg(-1)), Co (0.48-1.1 mg kg(-1)), Cu (4.8-8.4 mg kg(-1)), Zn (75-153 mg kg(-1)), Cr (1.0-4.5 mg kg(-1)) and Fe (283-930 mg kg(-1)) were detected in bivalve species, particularly in M. galloprovincialis from Ebro and Po deltas, whereas the highest content of Hg was found in P. flesus (0.86 mg kg(-1)). In fish species, most Hg was organic (MeHg; from 69 to 79%), whereas lower proportions of MeHg were encountered in bivalve species (between 20 and 43%). The highest levels of As were found in macroalgae species L. digitata and S. latissima (41 mg kg(-1) and 43 mg kg(-1), respectively), with iAs accounting almost 50% of the total As content in L. digitata but not with S. latissima nor in the remaining seafood samples. This work highlights that the selection of the most appropriate bioindicator species is a fundamental step in environmental monitoring of each contaminant, especially in coastal areas. Furthermore, data clearly shows that the current risk assessment and legislation solely based on total As or Hg data is limiting, as elemental speciation greatly varies according to seafood species, thus playing a key role in human exposure assessment via food.


Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/análise , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise , Animais , Arsenicais/análise , Bivalves/química , Europa (Continente) , Peixes/metabolismo , Cadeia Alimentar , Limite de Detecção , Metais Pesados/toxicidade , Compostos de Metilmercúrio/análise , Compostos de Metilmercúrio/toxicidade , Alimentos Marinhos/normas , Alga Marinha/química , Poluentes Químicos da Água/toxicidade
15.
Environ Monit Assess ; 185(8): 6653-66, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23275095

RESUMO

Monitoring of amnesic shellfish poisoning (ASP) toxins in shellfish from the Catalan coast started in 2001. No ASP toxins were detected in any of the analyses performed before 2008. On 22 January 2008, domoic acid (DA) was detected in Donax trunculus (0.5 mg kg(-1)) and confirmed by rapid resolution liquid chromatography-tandem mass spectrometry (0.6 mg kg(-1)). A total of 974 shellfish samples were analyzed from January 2008 to December 2011, covering all the Catalan production areas and the most important marketed species. DA was detected in 23.8 % of the samples and was recorded every month in all areas and all species, except Ostrea edulis, although the percentage of samples with DA and DA content varied widely among samples. DA exceeded the regulatory level of 20 mg kg(-1) twice: in Callista chione sampled on February 2008 and in D. trunculus sampled on April 2010. DA content in Bolinus brandaris appeared constant and close to 4.5 mg kg(-1) for months in 2009. Mytilus galloprovincialis, Crassostrea gigas, and Ruditapes sp. presented very low concentrations of DA in the Ebro Delta bays, despite 113 alert situations according to Pseudo-nitzschia spp. abundances and the high number of shellfish samples analyzed. The origin of DA in Catalan shellfish remains unknown.


Assuntos
Monitoramento Ambiental/métodos , Ácido Caínico/análogos & derivados , Frutos do Mar/análise , Poluentes Químicos da Água/análise , Animais , Contaminação de Alimentos/análise , Ácido Caínico/análise , Toxinas Marinhas/análise , Espanha
16.
J Phycol ; 49(6): 1056-60, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27007626

RESUMO

Knowledge concerning the ability of microalgae to produce metabolites of interest such as toxins or high-value secondary metabolites requires exhaustive details to be supplied on how the research was conducted. These should include the microalgal species and strain characterization, the culture conditions, the cell density, and physiological state at the time of harvesting, the harvesting method, the sample pre-treatment protocol, and the subsequent instrumental analytical separation/detection system. In this comment, we discuss issues that affect algal research from an analytical chemistry perspective, particularly (i) the need to specify detection capabilities of the entire method (i.e., limits of detection or threshold detection levels), which we illustrate in relation to classification of a species or strain as being "toxin producing" or "non-toxin producing"; and (ii) the requirements that have to be satisfied to confirm a microalgal species (new or not) as a producer of a particular chemical of interest for phycologists, which again we illustrate in relation to toxins. A successful collaboration among phycologists and analytical chemists will only be achieved as a result of a synergistic collaboration between the two disciplines, with a reciprocal understanding at least at a background level.

17.
Sci Total Environ ; 437: 209-18, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22940045

RESUMO

Pesticide usage in Delta del Ebro (NE Spain) during the rice growing season has been associated with oyster episodes of mortality that occur early in summer. However, there are no studies that have directly evaluated pesticide levels and effects in oysters (Crassotrea gigas) cultured in Ebro's Bays. In this study pesticide levels in water, metal body burdens and up to 12 different biochemical markers were monitored in gills and digestive glands of oysters transplanted from May to June in 2008 and 2009. Biochemical responses evidenced clear differences in oysters from 2008 and 2009. Oysters transplanted in 2009 showed their antioxidant defenses unaffected from May to June and consequently increased levels of tissue damage measured as lipid peroxidation and DNA strand breaks and of mortality rates. Conversely oysters transplanted in 2008 increase their antioxidant defenses from May to June, had low levels of lipid peroxidation and DNA damage and low mortality rates. Some pesticides in water such as bentazone and propanil together with high temperatures and salinity levels were related with tissue damage in oyster transplanted in 2008 but the observed large differences between years indicate that abiotic factors alone could not explain the high mortalities observed in 2009. An analysis of recent reported studies pointed out in the direction that in addition to abiotic factors the use of oysters sensitive to diseases may explain the observed responses.


Assuntos
Oryza/efeitos dos fármacos , Ostreidae/efeitos dos fármacos , Resíduos de Praguicidas/efeitos adversos , Animais , Biomarcadores/análise , Biomarcadores/metabolismo , Quebras de DNA/efeitos dos fármacos , Sistema Digestório/efeitos dos fármacos , Sistema Digestório/metabolismo , Monitoramento Ambiental/métodos , Brânquias/química , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Temperatura Alta/efeitos adversos , Peroxidação de Lipídeos/efeitos dos fármacos , Oryza/metabolismo , Ostreidae/crescimento & desenvolvimento , Resíduos de Praguicidas/análise , Salinidade , Espanha , Poluentes Químicos da Água/efeitos adversos , Poluentes Químicos da Água/análise , Qualidade da Água
18.
Appl Environ Microbiol ; 77(5): 1651-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21193668

RESUMO

The frequency and intensity of Pseudo-nitzschia spp. blooms along the coast of Catalonia have been increasing over the past 20 years. As species from this genus that are documented as toxigenic have been found in local waters, with both toxic and nontoxic species cooccurring in the same bloom, there is a need to develop management tools for discriminating the difference. Currently, differentiation of toxic and nontoxic species requires time-consuming electron microscopy to distinguish taxonomic features that would allow identification as to species, and cryptic species can still remain misidentified. In this study, cells of Pseudo-nitzschia from clonal cultures isolated from seawater were characterized to their species identity using scanning electron microscopy, and subsamples of each culture were used to create an internal transcribed spacer 1 (ITS-1), 5.8S, and ITS-2 ribosomal DNA database for development of species-specific quantitative PCR (qPCR) assays. Once developed, these qPCR assays were applied to field samples collected over a 2-year period in Alfaques Bay in the northwestern Mediterranean Sea to evaluate the possibility of a comprehensive surveillance for all Pseudo-nitzschia spp. using molecular methods to supplement optical microscopy, which can discern taxonomy only to the genus level within this taxon. Total Pseudo-nitzschia cell density was determined by optical microscopy from water samples collected weekly and compared to results obtained from the sum of eight Pseudo-nitzschia species-specific qPCR assays using duplicate samples. Species-specific qPCR followed by melt curve analysis allowed differentiation of amplicons and identification of false positives, and results correlated well with the total Pseudo-nitzschia cell counts from optical microscopy.


Assuntos
Diatomáceas/classificação , Diatomáceas/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Água do Mar/microbiologia , Análise por Conglomerados , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Diatomáceas/genética , Diatomáceas/ultraestrutura , Genes de RNAr , Mar Mediterrâneo , Microscopia Eletrônica de Varredura , Filogenia , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
19.
Anal Bioanal Chem ; 396(6): 2321-30, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20140666

RESUMO

This work describes the development and applicability of two functional assays for the detection of yessotoxin (YTX), a polycyclic ether marine toxin produced by dinoflagellates. The assays are based on the interaction between this toxin and the phosphodiesterase (PDE) enzyme and the subsequent measurement of the enzyme activity by colorimetric and electrochemical methods. Firstly, several enzyme substrates were tested in order to select those able to be detected by colorimetry or electrochemistry after enzymatic hydrolysis. The substrates that provided the highest absorbance values and density currents were p-nitrophenyl phenylphosphonate and alpha-naphthyl phosphate, respectively. After optimisation of the experimental parameters, limits of detection of 0.8 and 0.6 microM were attained by colorimetry and electrochemistry, respectively. An inhibitory effect of YTX on the PDE activity was observed. The assays have been applied to the analysis of YTX production by Protoceratium reticulatum cultures, and results were compared with liquid chromatography-tandem mass spectrometry analysis.


Assuntos
Colorimetria/métodos , Dinoflagelados/química , Oxocinas/análise , Inibidores de Fosfodiesterase/análise , Diester Fosfórico Hidrolases/química , Animais , Cromatografia Líquida/métodos , Crotalus/metabolismo , Eletroquímica , Limite de Detecção , Ligação Proteica , Espectrometria de Massas em Tandem/métodos
20.
Dis Aquat Organ ; 77(1): 53-9, 2007 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-17933397

RESUMO

Between January and April 2000, several experiments were performed during a Karlodinium spp. proliferation in Alfacs Bay (Ebro delta, NW Mediterranean) to determine the effects of these dinoflagellates on sea bream Sparus aurata cultivated in the area. Moribund fish showed an increase in plasma osmolality together with a decrease in the haematocrit percentage compared to control fish. The efficacy of copper sulphate, hydrogen peroxide, potassium permanganate and formalin against Karlodinium spp. was also tested. None of these treatments had mitigation effects when applied in the presence of fish; on the contrary, lethal effects appeared at lower Karlodinium spp. densities compared to fish control groups. When a lytic agent, such as copper sulphate, was used as a water pre-treatment, in the absence of fish, Karlodinium spp. toxicity was significantly reduced. Protocols for water pre-treatments were studied as a potential tool for combating Karlodinium spp. in fish farms.


Assuntos
Dinoflagelados/efeitos dos fármacos , Doenças dos Peixes/prevenção & controle , Doenças dos Peixes/parasitologia , Hematócrito/veterinária , Concentração Osmolar , Infecções Protozoárias em Animais , Dourada/parasitologia , Animais , Aquicultura , Sulfato de Cobre/toxicidade , Dinoflagelados/fisiologia , Desinfetantes/toxicidade , Doenças dos Peixes/mortalidade , Doenças dos Peixes/fisiopatologia , Formaldeído/toxicidade , Peróxido de Hidrogênio/toxicidade , Permanganato de Potássio/toxicidade , Infecções por Protozoários/mortalidade , Infecções por Protozoários/fisiopatologia , Infecções por Protozoários/prevenção & controle
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