135 research outputs found

    Tetrodotoxins (Ttxs) and vibrio alginolyticus in mussels from central adriatic sea (italy): Are they closely related?

    Get PDF
    Tetrodotoxins (TTXs), potent neurotoxins, have become an increasing concern in Europe in recent decades, especially because of their presence in mollusks. The European Food Safety Authority published a Scientific Opinion setting a recommended threshold for TTX in mollusks of 44 µg equivalent kg−1 and calling all member states to contribute to an effort to gather data in order to produce a more exhaustive risk assessment. The objective of this work was to assess TTX levels in wild and farmed mussels (Mytilus galloprovincialis) harvested in 2018–2019 along the coastal area of the Marche region in the Central Adriatic Sea (Italy). The presence of Vibrio spp. carrying the non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes, which are suspected to be involved in TTX biosynthesis, was also investigated. Out of 158 mussel samples analyzed by hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILICMS/MS), 11 (7%) contained the toxins at detectable levels (8–26 µg kg−1 ) and 3 (2%) contained levels above the EFSA safety threshold (61–76 µg kg−1 ). Contaminated mussels were all harvested from natural beds in spring or summer. Of the 2019 samples, 70% of them contained V. alginolyticus strains with the NRPS and/or PKS genes. None of the strains containing NRPS and/or PKS genes showed detectable levels of TTXs. TTXs in mussels are not yet a threat in the Marche region nor in Europe, but further investigations are surely needed

    USE OF CAGED MUSSEL MYTILUS GALLOPROVINCIALIS IN AN ECOTOXICOLOGICAL APPROACH TO ASSESS ENVIRONMENTAL IMPACT IN OFF-SHORE ACTIVITIES

    Get PDF
    Abstract Mediterranean mussels, Mytilus galloprovincialis, are well recognized bioindicator organisms which can be easily caged in investigated areas to assess the impact of anthropogenic activities. In this work a monitoring protocol was developed for off-shore installations in the Adriatic sea. Integration of chemical analyses with a wide range of biomarkers analysed in mussels caged at 2 platforms, allowed to evaluate the biological disturbance and confirmed the utility of the ecotoxicological approach for monitoring off-shore activities. Keywords : Bio-indicators, Adriatic Sea. Several environmental issues are associated with the off-shore oil and gas industry, from the impact caused during installation to various form of disturbance related to daily ship traffic, extraction activities, maintenance of structures and, finally, decommissioning of old platforms. During the last year a monitoring protocol with caged mussels, Mytilus galloprovincialis, has been developed, to evaluate the potential ecotoxicological effects caused from the off-shore platform "Giovanna" in the Adriatic sea. Obtained results allowed to exclude marked biological disturbance and demonstrated the suitability of this approach. In this respect considering "Giovanna" as model platform, the monitoring protocol with caged mussel has been extended including also another off-shore installation, the "Emilio" platform. In this work native mussels were collected on a seasonal basis from a reference site on the Adriatic coast (Portonovo, Ancona) and transplanted for 4-6 weeks in both the sampling area and to the investigated platform "Giovanna" (42 • 46' 060N, 14 • 27' 750E) and Emilio (42 • 56' 305 N; 14 • 13' 915 E). After the translocation period, mussels were recovered dissected tissues frozen in liquid nitrogen and maintained at -80 • C until analyses. Chemical analyses on trace metals (arsenic, cadmium, chromium, copper, iron, mercury, manganese, nickel, lead, zinc) in mussels tissues An overall evaluation of results confirmed the absence of marked biological effects caused by the activities of "Giovanna" platform, as already demonstrated during the previous monitoring project. More variations were observed in mussels translocated to "Emilio", i.e. higher activities of glutathione S-transferases, catalase and peroxisomal proliferation decrease of oxyradical scavenging capacity toward hydroxyl and peroxyl radicals and lysosomal destabilization (inhibition of neutral red retention time), indicating an onset of impairment condition in the organisms. Compared to mussels transplanted at the reference site, those from "Emilio" platform did not exhibit more elevated concentrations for the various metals and only for zinc and cadmium an higher bioavailability was detected close to the platform, suggesting the influence of galvanic anodes for cathodic protection. The overall results of this work confirmed the utility of using caged mussels as an additional contribution for monitoring off-shore activities and provided an ecotoxicological protocol based on cellular biomarkers for the early detection of biological disturbance

    Long-lasting effects of chronic exposure to chemical pollution on the hologenome of the Manila clam

    Get PDF
    Chronic exposure to pollutants affects natural populations, creating specific molecular and biochemical signatures. In the present study, we tested the hypothesis that chronic exposure to pollutants might have substantial effects on the Manila clam hologenome long after removal from contaminated sites. To reach this goal, a highly integrative approach was implemented, combining transcriptome, genetic and microbiota analyses with the evaluation of biochemical and histological profiles of the edible Manila clam Ruditapes philippinarum, as it was transplanted for 6 months from the polluted area of Porto Marghera (PM) to the clean area of Chioggia (Venice lagoon, Italy). One month post‐transplantation, PM clams showed several modifications to its resident microbiota, including an overrepresentation of the opportunistic pathogen Arcobacter spp. This may be related to the upregulation of several immune genes in the PM clams, potentially representing a host response to the increased abundance of deleterious bacteria. Six months after transplantation, PM clams demonstrated a lower ability to respond to environmental/physiological stressors related to the summer season, and the hepatopancreas‐associated microbiota still showed different compositions among PM and CH clams. This study confirms that different stressors have predictable effects in clams at different biological levels and demonstrates that chronic exposure to pollutants leads to long‐lasting effects on the animal hologenome. In addition, no genetic differentiation between samples from the two areas was detected, confirming that PM and CH clams belong to a single population. Overall, the obtained responses were largely reversible and potentially related to phenotypic plasticity rather than genetic adaptation. The results here presented will be functional for the assessment of the environmental risk imposed by chemicals on an economically important bivalve species

    Variation of Basal EROD Activities in Ten Passerine Bird Species – Relationships with Diet and Migration Status

    Get PDF
    Inter-specific differences in animal defence mechanisms against toxic substances are currently poorly understood. The ethoxyresorufin-O-deethylase (EROD) enzyme plays an important role in defence against toxic chemicals in a wide variety of animals, and it is an important biomarker for environmental contamination. We compared basal hepatic EROD activity levels among ten passerine species to see if there is inter-specific variation in enzyme activity, especially in relation to their diet and migration status. Migratory insectivores showed higher EROD activity compared to granivores. We hypothesize that the variable invertebrate diet of migratory insectivores contains a wider range of natural toxins than the narrower diet of granivores. This may have affected the evolution of mixed function oxidases (MFO) system and enzyme activities. We further tested whether metabolic rates or relative liver size were associated with the variation in detoxification capacity. We found no association between EROD activity and relative (per mass unit) basal metabolic rate (BMR). Instead, EROD activity and relative liver mass (% of body mass) correlated positively, suggesting that a proportionally large liver also functions efficiently. Our results suggest that granivores and non-migratory birds may be more vulnerable to environmental contaminants than insectivores and migratory birds. The diet and migration status, however, are phylogenetically strongly connected to each other, and their roles cannot be fully separated in our analysis with only ten passerine species

    Metal Bioavailability in the Sava River Water

    Get PDF
    Metals present one of the major contamination problems for freshwater systems, such as the Sava River, due to their high toxicity, persistence, and tendency to accumulate in sediment and living organisms. The comprehensive assessment of the metal bioavailability in the Sava River encompassed the analyses of dissolved and DGT-labile metal species of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the river water, as well as the evaluation of the accumulation of five metals (Cd, Cu, Fe, Mn, and Zn) in three organs (liver, gills, and gastrointestinal tissue) of the bioindicator organism, fish species European chub (Squalius cephalus L.).This survey was conducted mainly during the year 2006, in two sampling campaigns, in April/May and September, as periods representative for chub spawning and post-spawning. Additionally, metal concentrations were determined in the intestinal parasites acanthocephalans, which are known for their high affinity for metal accumulation. Metallothionein concentrations were also determined in three chub organs, as a commonly applied biomarker of metal exposure. Based on the metal concentrations in the river water, the Sava River was defined as weakly contaminated and mainly comparable with unpolluted rivers, which enabled the analyses of physiological variability of metal and metallothionein concentrations in the chub organs, as well as the establishment of their constitutive levels
    corecore