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1.
J Environ Sci (China) ; 111: 24-37, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34949353

RESUMO

Polycyclic aromatic hydrocarbons (PAHs), as persistent toxic substances (PTS), have been widely monitored in coastal environment, including seawater and sediment. However, scientific monitoring methods, like ecological risk assessment and integrated biomarker response, still need massive researches to verify their availabilities. This study was performed in March, May, August and October of 2018 at eight sites, Yellow River estuary (S1), Guangli Port (S2), Xiaying (S3), Laizhou (S4), Inner Bay (S5), Outer Bay (S6), Hongdao (S7) and Hongshiya (S8) of Shandong Peninsula, China. The contents of 16 priority PAHs in local seawater and sediment were determined, by which ecological risk assessment risk quotient (RQ) for seawater and sediment quality guidelines (SQGs) were calculated to characterize the PAHs pollution. Meanwhile, multiple biomarkers in the digestive gland of clam Ruditapes philippinarum were measured to represent different biological endpoints, including ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), sulfotransferase (SULT), superoxide dismutase (SOD) and lipid peroxidation (LPO), by which integrated biomarker response (IBR) was calculated to provide a comprehensive assessment of environmental quality. Taken together, these results revealed the heaviest pollution at S2 as both PAHs concentrations and biomarkers responses reflected, and supported the integrated biomarker response as a useful tool for marine environmental monitoring, through its integration with SQGs.


Assuntos
Bivalves , Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Biomarcadores , China , Sedimentos Geológicos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise
2.
J Environ Manage ; 301: 113866, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34624574

RESUMO

The uses of bivalve molluscs in environmental biomonitoring have recently gained momentum due to their ability to indicate and concentrate human pathogenic microorganisms. In the context of the health crisis caused by the COVID-19 epidemic, the objective of this study was to determine if the SARS-CoV-2 ribonucleic acid genome can be detected in zebra mussels (Dreissena polymorpha) exposed to raw and treated urban wastewaters from two separate plants to support its interest as bioindicator of the SARS-CoV-2 genome contamination in water. The zebra mussels were exposed to treated wastewater through caging at the outlet of two plants located in France, as well as to raw wastewater in controlled conditions. Within their digestive tissues, our results showed that SARS-CoV-2 genome was detected in zebra mussels, whether in raw and treated wastewaters. Moreover, the detection of the SARS-CoV-2 genome in such bivalve molluscans appeared even with low concentrations in raw wastewaters. This is the first detection of the SARS-CoV-2 genome in the tissues of a sentinel species exposed to raw and treated urban wastewaters. Despite the need for development for quantitative approaches, these results support the importance of such invertebrate organisms, especially zebra mussel, for the active surveillance of pathogenic microorganisms and their indicators in environmental waters.


Assuntos
Bivalves , COVID-19 , Dreissena , Animais , Dreissena/genética , Humanos , SARS-CoV-2 , Águas Residuárias
3.
Food Microbiol ; 102: 103921, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809947

RESUMO

Hepatitis A virus (HAV) continues to be a public health concern and has caused large foodborne outbreaks and economic losses worldwide. Rapid detection of HAV in foods can help to confirm the source of outbreaks in a timely manner and prevent more people getting infected. In order to efficiently detect HAV at low levels of contamination in foods, rapid and easy-to-use techniques are required to separate and concentrate viral particles to a small volume. In the current study, HAV particles were eluted from green onion, strawberry, and mussel using glycine buffer (0.05 M glycine, 0.14 M NaCl, 0.2% (v/v) Tween 20, pH 9.0) and suspended viral particles were captured using protamine-coated magnetic nanoparticles (PMNPs). This process caused a selective concentration of the viral particles, which could be followed by quantitative real-time RT-PCR analysis. Results showed that pH, NaCl concentration, and PMNP amount used for the capturing had significant effects on the recovery efficiency of HAV (P < 0.05). The highest recovery rate was obtained at pH 9.0, 0.14 M NaCl, and 50 µL of PMNPs. The optimized PMNP capturing method enabled the rapid capture and concentration of HAV. A sensitive real-time RT-PCR test was developed with detection limits of 8.3 × 100 PFU/15 g, 8.3 × 101 PFU/50 g, and 8.3 × 100 PFU/5 g of HAV in green onion, strawberry, and mussel, respectively. In conclusion, the PMNP method is rapid and convenient in capturing HAV from complex solid food samples and can generate concentrated HAV sample solutions suitable for high-sensitivity real time RT-PCR detection of the virus.


Assuntos
Bivalves/virologia , Contaminação de Alimentos/análise , Fragaria/virologia , Vírus da Hepatite A/isolamento & purificação , Nanopartículas de Magnetita , Cebolas/virologia , Animais , Compostos Férricos , Vírus da Hepatite A/genética , Protaminas , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
4.
Sci Total Environ ; 806(Pt 1): 150567, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34844324

RESUMO

An improved microcontroller-based device for real-time biomonitoring of mussel behaviour is introduced in this study. Open source Arduino platforms were used as processing cores and infra-red (IR) sensors (with transistor output) and Hall sensors to record the cardiac activities and valve movements of mussels. Compared to the devices described in previous studies, this device has low cost, high throughput, and high portability, and can be applied to conduct real-time preliminary automatic data processing. Mediterranean mussels were exposed to Cu2+ and microplastics and their cardiac activities and valve movements were recorded. The results demonstrated that Cu2+ exposure caused valve closure and a drop in the heart rate, similar to the behaviour during natural periods of bradycardia in mussels. The microplastic exposures tended to cause high oscillations (low concentration of microplastics) and slow decreases (high concentration of microplastics) of the maximum valve open positions. Such oscillations and decreases appeared to reset and restart after the bradycardia period. The device has potential to measure and establish behavioural responses of mussels and other bivalves, to the stress of exposure from environmental contaminants.


Assuntos
Bivalves , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Microplásticos , Plásticos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
5.
Colloids Surf B Biointerfaces ; 209(Pt 2): 112173, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34749192

RESUMO

Nanoparticles (NPs) can be produced via physical, chemical, or biological approaches. Yet, the impact of the synthesis approaches on the environmental fate and effects of NPs is poorly understood. Here, we synthesized AgNPs through chemical and biological approaches (cit-AgNPs and bio-AgNPs), characterized their properties, and toxicities relative to commercially available Ag nanopowder (np-AgNPs) to the clam Mercenaria mercenaria. The chemical synthesis is based on the reduction of ionic silver using sodium borohydride as a reducing agent and trisodium citrate as a capping agent. The biological synthesis is based on the reduction of ionic silver using biomolecules extracted from an atoxigenic strain of a filamentous fungus Aspergillus parasiticus. The properties of AgNPs were determined using UV-vis, dynamic light scattering, laser Doppler electrophoresis, (single particle)-inductively coupled plasma-mass spectroscopy, transmission electron microscopy, and asymmetric flow-field flow fractionation. Both chemical and biological synthesis approaches generated spherical AgNPs. The chemical synthesis produced AgNPs with narrower size distributions than those generated through biological synthesis. The polydispersity of bio-AgNPs decreased with increases in cell free extract (CFE):Ag ratios. The magnitude of the zeta potential of the cit-AgNPs was higher than those of bio-AgNPs. All AgNPs formed aggregates in the test media i.e., natural seawater. Based on the same total Ag concentrations, all AgNPs were less toxic than AgNO3. The toxicity of AgNPs toward the juvenile clam, Mercenaria mercenaria, decreased following the order np-AgNPs > cit-AgNPs > bio-AgNPs. Expressed as a function of dissolved Ag concentrations, the toxicity of Ag decreased following the order cit-AgNPs > bio-AgNPs > AgNO3 ~ np-AgNPs. Therefore, the toxicity of AgNP suspensions can be attributed to a combined effect of dissolved and particulate Ag forms. These results indicate that AgNP synthesis methods determine their environmental and biological behaviors and should be considered for a more comprehensive environmental risk assessment of AgNPs.


Assuntos
Bivalves , Nanopartículas Metálicas , Animais , Difusão Dinâmica da Luz , Nanopartículas Metálicas/toxicidade , Extratos Vegetais , Prata/toxicidade
6.
J Hazard Mater ; 423(Pt A): 127078, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-34523496

RESUMO

Beibu Gulf is an important shellfish aquaculture area in the northwest of the South China Sea, China. In this study, the toxin profile and spatial-temporal distribution of domoic acid (DA) and 10 lipophilic phycotoxins were systematically analyzed in the bivalve mollusks collected in Beibu Gulf from October 2018 to October 2020. Neurotoxin DA was first detected in the mollusks from the investigative regions with a prevalence of 17.7%, peaking at 401 µg kg-1. Cyclic imines (CIs) including gymnodimine-A (GYM-A, 46.6%) and 13-desmethyl-spirolide-C (SPX1, 15.8%) predominated the lipophilic phycotoxins in shellfish, peaking at 10.1 µg kg-1 and 19.6 µg kg-1, respectively. Gymnodimine-A partially accompanied by SPX1 was detected in all batches of shellfish samples, suggesting that Alexandrium ostenfeldii and Karenia selliformis were possible sources of CIs-group toxins in Beibu Gulf. During the investigative period, relatively higher levels of DA occurred in shellfishes from March to August, while slightly higher contents of CIs in mollusks appeared in October and December. Spatial distribution of the targeted phycotoxins demonstrated that shellfishes tended to accumulate relatively higher contents of toxins in Lianzhou, Qinzhou and Tieshan bays.


Assuntos
Bivalves , Toxinas Marinhas , Animais , China , Iminas , Ácido Caínico/análogos & derivados , Prevalência
7.
Chemosphere ; 288(Pt 1): 132410, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34600016

RESUMO

Widespread intertidal mussels are exposed to a variety of natural and anthropogenic stressors. Even so, our understanding of the combined influence of stressors such as predation risk and ocean acidification (OA) on these species remains limited. This study examined the response of the purple mussel (Perumytilus purpuratus), a species distributed along Pacific southeastern rocky shores, to the effects of predation risk and OA. Using a laboratory 2 × 2 cross design, purple mussels were either devoid or exposed to predator cues from the muricid snail Acanthina monodon, while simultaneously exposing them to current (500 ppm) or projected OA conditions (1500 ppm). The response of purple mussels to these factors was assessed using growth, calcification, clearance, and metabolic rates, in addition to byssus production. After 60 d, the presence of predator cues reduced mussel growth in width and length, and in the latter case, OA enhanced this response making the effects of predator cues more severe. Calcification rates were driven by the interaction between the two stressors, whereas clearance rates increased only in response to OA, likely explaining some of the growth results. Mussel byssus production also increased with pCO2 but interacted with predation risk: in the absence of predator cues, byssus production increased with OA. These results suggest that projected levels of OA may alter and in some cases prevail over the natural response of purple mussels to predation risk. Considering the role played by this mussel as a dominant competitor and ecosystem engineer in rocky shores, these results have community-wide implications.


Assuntos
Bivalves , Ecossistema , Animais , Concentração de Íons de Hidrogênio , Oceanos e Mares , Comportamento Predatório , Água do Mar , Caramujos
8.
Sci Total Environ ; 806(Pt 1): 150369, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34571231

RESUMO

In coastal systems, pollutants as pharmaceutical drugs exert changes from the molecular to the organism level in marine bivalves. Besides pollutants, coastal systems are prone to changes in environmental parameters, as the alteration of salinity values because of Climate Change. Together, these stressors (pharmaceutical drugs and salinity changes) can exert different threats than each stressor acting individually; for example, salinity can change the physical-chemical properties of the drugs and/or the sensitivity of the organisms to them. However, limited information is available on this subject, with variable results, and for this reason, this study aimed to evaluate the impacts of salinity changes (15, 25 and 35) on the effects of the antiepileptic carbamazepine (CBZ, 1 µg/L) and the antihistamine cetirizine (CTZ, 0.6 µg/L), when acting individually and combined (CBZ + CTZ), in the edible clam Ruditapes philippinarum. After 28 days of exposure, drugs concentrations, bioconcentration factors and biochemical parameters, related to clam's metabolic capacity and oxidative stress were evaluated. The results showed that clams under low salinity suffered more changes in metabolic, antioxidant and biotransformation activities, in comparison with the remaining salinities under study. However, limited impacts were observed when comparing drug effects at low salinity. Indeed, it seemed that CTZ and CBZ + CTZ, under high salinity (salinity 35) were the worst exposure conditions for the clams, since they caused higher levels of cellular damage. It stands out that salinity changes altered the impact of pharmaceutical drugs on marine bivalves.


Assuntos
Bivalves , Preparações Farmacêuticas , Poluentes Químicos da Água , Animais , Anticonvulsivantes , Biomarcadores/metabolismo , Bivalves/metabolismo , Antagonistas dos Receptores Histamínicos , Estresse Oxidativo , Salinidade , Poluentes Químicos da Água/toxicidade
9.
Environ Res ; 203: 111793, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34339694

RESUMO

Considering the ecological risks of polycyclic aromatic hydrocarbons (PAHs) to the marine environment, it is urgent to find scientific and effective monitoring methods. In this study, an integrated approach combining chemical ecological risk assessment and multi-integrated biomarker indexes approach was used to assess the marine environment. Samples included seawater, sediments, and clam Ruditapes philippinarum were collected from four bays on the Shandong Peninsula, China in the four seasons of 2019. The concentrations, composition, potential sources, and ecological risk of PAHs were investigated in seawater and sediments. Risk quotient (RQ) and sediment quality guidelines (SQGs) were calculated to assess the ecological risks of PAHs in seawater and sediment, respectively. And then, clam Ruditapes philippinarum's multi-level biological response, including its ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), superoxide dismutase (SOD), lipid peroxidation (LPO), and acetylcholinesterase (AChE) were investigated in-depth, by which multi-integrated biomarker indexes approach were calculated to evaluate marine environmental quality. Taken together, the results showed that the concentration of PAHs was in good agreement with the response of biomarkers, and the usefulness of the combined use of chemical ecological risk assessment and integrated biomarker indexes to assess PAHs pollution was verified.


Assuntos
Bivalves , Poluentes Químicos da Água , Acetilcolinesterase , Animais , Baías , Biomarcadores , China , Monitoramento Ambiental , Medição de Risco , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
10.
Chemosphere ; 286(Pt 2): 131675, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34358890

RESUMO

Caffeine has been identified as emerging contaminant of concern due to its widespread occurrence in the aquatic environment and potential to be biologically active. Recently, these concerns have been translated in an increasing research on its occurrence and effects on biota. However, there is still a limited knowledge on seawater matrices and the implications of caffeine presence in coastal and marine ecosystems are not fully known. The present review aims to fill these knowledge gaps, analysing the existing literature regarding the occurrence, effects and potential risks of caffeine residues to coastal ecosystems, contributing to the risk assessment of this psychoactive drug in the aquatic environment. The analysed literature reported caffeine concentrations in the coastal ecosystems, raising high concerns about the potential adverse impacts on the ecological safety and human health. Caffeine has been found in tissues from coastal and marine biota including microalgae, coral reefs, bivalves and fish due to bioaccumulation after chronic, long-term exposures in a contaminated environment. Additionally, caffeine residues had been demonstrated to have adverse impacts on aquatic organisms, at environmentally realistic concentrations, inducing oxidative stress and lipid peroxidation, neurotoxicity, changing energy reserves and metabolic activity, affecting reproduction and development and, in some cases, causing mortality. Considering the increasing adverse impacts of caffeine pollution in the coastal environment, this review highlights the urgent need to minimize the increasing load of caffeine to the aquatic ecosystems; being imperative the implementation of scientific programs and projects to classify effectively the caffeine as a high-priority environmentally hazardous emerging pollutant.


Assuntos
Bivalves , Poluentes Químicos da Água , Animais , Cafeína/análise , Cafeína/toxicidade , Ecossistema , Humanos , Água do Mar , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
11.
Biol Trace Elem Res ; 200(1): 385-401, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33590454

RESUMO

Filter-feeder bivalves such as non-indigenous Ruditapes philippinarum absorb and accumulate metals, resulting in multi-element profiles. The goal of this study was to analyse spatial and temporal distributions of the multi-element signatures in R. philippinarum populations of the Tagus and Sado estuaries (SW coast, Portugal). The clam and sediment samples were collected at three sampling sites in each estuary, on three sampling occasions, and the analysis were done by ICP-MS (inductively coupled plasma mass spectrometry). The chemical elements were categorized according to estuarine geomorphology sources (Se, Co, Ni and Cu), elements with function in metabolic processes of the clams (Mn, Fe, Zn and Cr) and elements derived from the anthropogenic inputs (As, Pb and Cd). Zinc, Co, Ni and Pb were the main contributors for the chemical signatures of Tagus estuary populations, whilst for the Sado estuary populations were Cu, Fe, Cr, As and Cd. They were representative of all elemental categories and proved to be spatial and temporal habitat discriminators of bivalves' estuarine populations. The multi-element signatures of R. philippinarum as a natural tag derived from the physical and chemical conditions of its habitat is a potential rapid tool to use in ecological monitoring and habitat assessment.


Assuntos
Bivalves , Metais Pesados , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Estuários , Sedimentos Geológicos , Metais Pesados/análise , Poluentes Químicos da Água/análise
12.
Sci Total Environ ; 806(Pt 4): 150807, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34626624

RESUMO

The West Coast of Ireland hosts many of the few populations of Freshwater Peal Mussels (FPM) left in Europe. The decline of this keystone species is strongly related to deteriorating hydrological conditions, specifically to the threat of low flows during dry summers. Populations still capable of reproducing require a minimum discharge and flow velocity to support juvenile mussels, or else stress builds up and an entire generation may be lost. Monitoring environmental and hydrological conditions in small and remote FPM catchments is difficult due to the lack of infrastructure. Indices derived from remote sensing imagery can be used to assess hydrological variables at the catchment scale. Here, five indices are tested as possible surrogates for soil moisture and evapotranspiration, based on two relevant land-cover types: open peat habitats (OPH) and forestry. Selected indices are then assessed in their ability to reproduce seasonal patterns and in their response to a severe drought event. The moisture stress index (MSI) and normalized difference vegetation index (NDVI) were found to be the best surrogates for soil moisture and evapotranspiration respectively. Both indices showed seasonality patterns in the two land-cover types, although the variability of MSI was significantly higher. During the 2018 drought, MSI visibly increased only in OPH, while NDVI rose only for forestry. The results suggest that OPH enhances the long-term hydrological resilience of a catchment by conserving water in the peat substrate, while industrial forestry plantations exacerbate the pressure on water during drier periods. This has consequences for river discharge, freshwater biodiversity and specifically for FPM. Implementing these surrogates have the potential to identify land-use management strategies that reduce and even avert the effects of drought on FPM. Such strategies are increasingly necessary in a climate change context, as recurring summer droughts are expected in most of Europe.


Assuntos
Bivalves , Tecnologia de Sensoriamento Remoto , Animais , Secas , Água Doce , Hidrologia
13.
J Environ Manage ; 302(Pt A): 113987, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34700084

RESUMO

Man-made, drainable aquaculture ponds have the potential to affect the water quality in the receiving waters, but whether they act mainly as a source or sink of fine sediments and nutrients is still unclear. Particularly in oligotrophic streams containing populations of the highly endangered freshwater pearl mussel (Margaritifera margaritifera), even low additional inputs pose the threat of exceeding thresholds for downstream habitat quality. In this study, the effluent quality during the drainage of two extensively used cyprinid ponds with a size of 0.103 and 0.150 ha was monitored at a high temporal resolution, to characterize the nutrient and sediment loading into the receiving stream under two different management scenarios. The loading of total suspended solids (TSS) was disproportionally dominated by the final step of pond drainage during the fish harvest, when a proportion of 30% of the particles released over the entire drainage process was released with only 1% of the total water volume drained. The continuous release of the ponds' surface water resulted in an additional loading of 28.8 kg/ha of NO3-N, 0.82 kg/ha of NH4-N and 0.58 kg/ha of total-P that was not strongly enhanced by the fish harvest. Using a settling pond was an efficient measure to reduce the amount of suspended particles and excess ammonium and phosphorous reaching the receiving stream. Without such a measure, TSS concentrations in the receiving stream during the fish harvest were elevated to a maximum of >900 mg/l, representing a 20-fold increase compared to 45 mg/l upstream. However, about 1/3 of the released TSS were retained in the overgrown outflow ditch. The differences in loading and retention patterns of dissolved and particulate pollutants revealed the need for divergent approaches to address suspended or dissolved pollutants: Physical settling structures can be effective at reducing particulate inputs, but they might not be sufficient to mitigate the negative effects on oligotrophic streams without a specific design to sustainably remove nutrients. This information on drainage management is not only relevant for minimizing the impacts of aquaculture ponds on downstream ecosystems, but also for the maintenance of nature conservation and flood retention ponds.


Assuntos
Bivalves , Lagoas , Animais , Ecossistema , Monitoramento Ambiental , Humanos , Nutrientes , Fósforo/análise
14.
Zool Res ; 43(1): 111-128, 2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-34904419

RESUMO

In most eukaryotes, oxidative phosphorylation (OXPHOS) is the main energy production process and it involves both mitochondrial and nuclear genomes. The close interaction between the two genomes is critical for the coordinated function of the OXPHOS process. Some bivalves show doubly uniparental inheritance (DUI) of mitochondria, where two highly divergent mitochondrial genomes, one inherited through eggs (F-type) and the other through sperm (M-type), coexist in the same individual. However, it remains a puzzle how nuclear OXPHOS genes coordinate with two divergent mitochondrial genomes in DUI species. In this study, we compared transcription, polymorphism, and synonymous codon usage in the mitochondrial and nuclear OXPHOS genes of the DUI species Ruditapes philippinarum using sex- and tissue-specific transcriptomes. Mitochondrial and nuclear OXPHOS genes showed different transcription profiles. Strong co-transcription signal was observed within mitochondrial (separate for F- and M-type) and within nuclear OXPHOS genes but the signal was weak or absent between mitochondrial and nuclear OXPHOS genes, suggesting that the coordination between mitochondrial and nuclear OXPHOS subunits is not achieved transcriptionally. McDonald-Kreitman and frequency-spectrum based tests indicated that M-type OXPHOS genes deviated significantly from neutrality, and that F-type and M-type OXPHOS genes undergo different selection patterns. Codon usage analysis revealed that mutation bias and translational selection were the major factors affecting the codon usage bias in different OXPHOS genes, nevertheless, translational selection in mitochondrial OXPHOS genes appears to be less efficient than nuclear OXPHOS genes. Therefore, we speculate that the coordination between OXPHOS genes may involve post-transcriptional/translational regulation.


Assuntos
Bivalves , Genoma Mitocondrial , Animais , Bivalves/genética , Genes Mitocondriais , Mitocôndrias/genética , Fosforilação Oxidativa
15.
Environ Pollut ; 295: 118671, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34902528

RESUMO

Freshwater mussels are among the most endangered groups of fauna anywhere in world. The indiscriminate use of antibiotics has led to the emergence of resistant strains. These antibiotic-resistant bacteria play a key role in increasing the risk allied with the use of surface water and in spread of resistance genes. Two endangered freshwater mussel species, Margaritifera margaritifera and Potomida littoralis, were sampled at 4 sampling sites along a 50 km stretch of River Tua. Water samples were taken at same sites. Of the total of 135 isolates, 64.44% (39.26% from water and 25.19% from mussels) were coliform bacteria. Site T1, with the lowest concentration of coliform bacteria, and site T2 were the only ones where M. margaritifera was found. No E. coli isolates were found in this species and the pattern between water and mussels was similar. P. littoralis, which was present at T3/T4 sites, is the one that faces the highest concentration of bacterial toxins, which are found in treated wastewater effluents and around population centers. Sites T3/T4 have the isolates (water and mussels) with the highest resistance pattern, mainly to ß-lactams. Water and P. littoralis isolates (T3/T4) showed resistance to penicillins and their combination with clavulanic acid, and to cephalosporins, precisely to a fourth generation of cephalosporin antibiotics. The analysis provides important information on the risk to water systems, as well as the need to investigate possible management measures. It is suggested that future studies on the health status of freshwater bivalves should incorporate measures to indicate bacteriological water quality.


Assuntos
Bivalves , Animais , Bactérias , Água Doce , Rios , Alimentos Marinhos
16.
J Environ Sci (China) ; 112: 129-139, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34955196

RESUMO

This study analyzed the function of different glutathione S-transferase (GST) isoforms and detoxification metabolism responses in Manila clam, Ruditapes philippinarum, exposed to 4 kinds of polycyclic aromatic hydrocarbons (PAHs) single, and their mixtures for 15 days under laboratory conditions. 13 kinds of GSTs in R. philippinarum were classified, and the results of tissue distribution indicated that 12 kinds of GSTs (except GST sigma 3) expressed most in digestive glands. We detected the mRNA expression levels of aryl hydrocarbon receptor signaling pathway, and detoxification system in digestive glands of clams exposed to benzo[a]pyrene (BaP), chrysene (CHR), benzo[a]anthracene (BaA), benzo[b]fluoranthene (BbF), and BaP + CHR + BaA + BbF, respectively. Among these genes, we selected GST-sigma, GST-omega and GST-pi as potential indicators to BaP; GST-sigma, GST-A and GST-rho to CHR; GST-pi, GST-sigma, GST-A, GST-rho and GST-microsomal to BaA; GST-theta and GST-mu to BbF; while GST-pi and GST-mu to the mixture of BaP, CHR, BaA and BbF. Additionally, the bioaccumulation of PAHs in tissues increased remarkably over time, and showed an obvious dose-effect. Under the same concentration, the bioaccumulation in single exposure group was higher than that in mixture group, and the bioaccumulation of PAHs in tissues with different concentrations of stress was irregular. The results revealed the metabolic differences and bioaccumulation rules in clams exposed to four kinds of PAHs, and provided more valuable information for the PAHs risk assessment.


Assuntos
Bivalves , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Bioacumulação , Bivalves/efeitos dos fármacos , Bivalves/enzimologia , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Isoformas de Proteínas , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
17.
An Acad Bras Cienc ; 93(suppl 4): e20210140, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34909825

RESUMO

Despite the great diversity, economic and environmental importance of limnic mollusks, the group is still little investigated in the Brazilian semiarid region, especially in the state of Piauí. Thus, this work aims to gather information on the diversity of limnic mollusks in the Brazilian Northeast and the semiarid region, including new records for the state of Piauí, northeastern Brazil. For this, collections in the urban perimeter of the Itaim and Guaribas Rivers, municipalities of Itainópolis, and Picos, respectively, between October 2017 and September 2019. Besides, a literature review was conducted on studies of malacofauna in the Northeast and the Brazilian semiarid region. A total of 11 species from the classes Gastropoda and Bivalvia were collected on the rivers of Piauí, being the first record of Uncancylus concentricus for the Northeast region. For lotic environments in the state of Piauí, Drepanotrema schubarti, Pomacea canaliculata, Pisidium dorbignyi and Stenophysa marmorata were registered for the first time. Then, it was possible to verify that the Northeast of Brazil has 71 species registered, of which 34 occur in the semiarid. The diversity of species surveyed and the first record of the occurrence of several of them for the semiarid region demonstrate the importance of expanding studies involving this group to other areas. The present study is the first to gather and increase the information available on the fauna of limnic mollusks for the Northeast and Brazilian semiarid regions. The information gathered here may contribute to future research and to the species conservation and the environments they occupy, especially considering the presence of non- native and vector species.


Assuntos
Bivalves , Rios , Animais , Brasil , Cidades
18.
Dis Aquat Organ ; 147: 13-23, 2021 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-34734570

RESUMO

Perkinsus sp. protozoans are parasites of a wide variety of molluscs around the world and are responsible for episodes of mass mortalities and large economic losses for aquaculture industries and fisheries. The first step towards the management of infectious episodes is the reliable detection of Perkinsus species. While historic methods for diagnosis of Perkinsus sp. infections in mollusc hosts include histological, in vitro, molecular-genetic, and immunoassays, antibody-based diagnostic assays may prove most practical with development of improved reagents and techniques. This paper reviews historic developments of antibodies against Perkinsus species, and of diagnostic immunoassays. Thirteen research papers reported the development of antibodies against Perkinsus sp. or their extracellular products, mainly P. olseni and P. marinus. Nine of those tested the cross-reactivity of their antibodies against different life stages or species than the one used as immunogen. While all antibodies raised against trophozoites labelled hypnospores, several antibodies raised against hypnospores did not label trophozoites, suggesting antigenic differences between those cell types. Antibody specificity studies showed that there is antigenic heterogeneity between Perkinsus species and Perkinsus-like organisms, and also that common epitopes occur among Perkinsus species, as well as some dinoflagellates. This review summarizes the current knowledge and aims at helping the future development of Perkinsus species-specific antibodies and immunoassays.


Assuntos
Apicomplexa , Bivalves , Dinoflagelados , Animais , Aquicultura , Imunoensaio/veterinária , Moluscos
19.
Environ Monit Assess ; 193(12): 833, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34799782

RESUMO

The National Oceanic and Atmospheric Administration (NOAA), National Centers for Coastal Ocean Science (NCCOS) Mussel Watch Program (MWP), conducts basin-wide monitoring and place-based assessments using dreissenid mussels as bioindicators of chemical contamination in the Laurentian Great Lakes. Polycyclic aromatic hydrocarbons (PAHs) body burden results for the period 2009-2018 were combined into one dataset from multiple MWP studies allowing for a robust characterization of PAH contamination. Patterns in PAH data were identified using descriptive statistics and machine learning techniques. Relationships between total PAH concentration in dreissenid mussel tissue, impervious surface percentages, and PAH relative concentration were identified and used to build a predictive model for the Great Lakes Basin. Significant positive correlation was identified by the Spearman's rank correlation test between total PAH concentration and percent impervious surface. The findings support the paradigm that PAHs are primarily derived from land-based sources. Offshore and riverine locations had the lowest and highest median total PAH concentrations, respectively. PAH assemblages and ratios indicated that pyrogenic sources were more predominant than petrogenic sources and that PAHs at offshore sites exhibited relatively more weathering compared to inshore sites.


Assuntos
Bivalves , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Sedimentos Geológicos , Lagos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise
20.
Toxicon ; 204: 56-63, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34742781

RESUMO

Saxitoxin and its derivatives, the paralytic shellfish toxins (PSTs), are well known to be toxic to humans, and maximum permitted levels in seafood have been established by regulatory authorities in many countries. Monitoring of PSTs is typically performed using chemical methods which quantify the concentration of the individual PST analogues, of which there are many. However, since the toxicities of analogues are different, they do not equally contribute to the overall toxicity of the sample. To account for these differences, toxicity equivalency factors (TEFs) need to be determined for each analogue and applied. Currently there are no established TEFs for decarbamoyl gonyautoxin 1&4 (dcGTX1&4), which occurs in some clam species such as Mactra chinensis contaminated with PSTs due to metabolism within the shellfish. In this study the median lethal dose of purified, equilibrated epimeric mixture of dcGTX1&4 has been determined by intraperitoneal injection (i.p.) (4.75 µmol/kg) and by feeding (34.9 µmol/kg). The most relevant route of exposure is orally with feeding being more representative of human consumption and more reliable than gavage. Based on the median lethal dose by feeding, a TEF of 0.1 is recommended for dcGTX1&4. Receptor binding activity and i.p. toxicity results showed dcGTX1&4 to be much less toxic than STX (140-170-fold). However, by feeding a much smaller difference in toxicity was observed with dcGTX1&4 being only 11-fold less toxic than STX. Analysis of the gut contents of mice dosed with dcGTX1&4 showed the presence of decarbamoyl gonyautoxin 2&3, decarbamoyl saxitoxin and decarbamoyl neosaxitoxin, all of which are of greater toxicity. This conversion of dcGTX1&4 within the digestive track to more toxic congeners may explain the high relative toxicity of dcGTX1&4 by feeding compared to that determined by i.p. and by sodium channel activity.


Assuntos
Bivalves , Intoxicação por Frutos do Mar , Animais , Camundongos , Saxitoxina/análogos & derivados , Saxitoxina/toxicidade , Frutos do Mar/análise
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