Occurrence of antibiotics in mussels and clams from various FAO areas

Tris(1-chloro-2-propyl) phosphate enhances the adverse effects of biodegradable polylactic acid microplastics on the mussel Mytilus coruscus

Microplastics (MPs) and organophosphate flame retardants (OPFRs) have recently become ubiquitous and cumulative pollutants in the oceans. Since OPFRs are added to or adsorbed onto MPs as additives, it is necessary to study the composite contamination of OPFRs and MPs, with less focus on bio-based PLA. Therefore, this study focused on the ecotoxicity of the biodegradable MP polylactic acid (PLA) (5 μm, irregular fragments, 102 and 106 particles/L), and a representative OPFRs tris(1-chloro-2-propyl) phosphate (TCPP, 0.5 and 50 μg/L) at environmental and high concentrations. The mussel Mytilus coruscus was used as a standardised bioindicator for exposure experiments. The focus was on examining oxidative stress (catalase, CAT, superoxide dismutase, SOD, malondialdehyde, MDA), immune responses acid (phosphatase, ACP, alkaline phosphatase, AKP, lysozyme, LZM), neurotoxicity (acetylcholinesterase, AChE), energy metabolism (lactate dehydrogenase, LDH, succinate dehydrogenase, SDH, hexokinase, HK), and physiological indices (absorption efficiency, AE, excretion rate, ER, respiration rate, RR, condition index, CI) after 14 days exposure. The results of significantly increased oxidative stress and immune responses, and significantly disturbed energy metabolism and physiological activities, together with an integrated biomarker response (IBR) analysis, indicate that bio-based PLA MPs and TCPP could cause adverse effects on mussels. Meanwhile, TCPP interacted significantly with PLA, especially at environmental concentrations, resulting in more severe negative impacts on oxidative and immune stress, and neurotoxicity. The more severe adverse effects at environmental concentrations indicate higher ecological risks of PLA, TCPP and their combination in the real marine environment. Our study presents reliable data on the complex effects of bio-based MP PLA, TCPP and their combination on marine organisms and the environment.

Copaiba oil's bactericidal activity and its effects on health and zootechnical performance for Nile tilapia after oral supplementation

Tilapia is one of the most important farmed fish in the world and the most cultivated in Brazil. The increase of this farming favors the appearance of diseases, including bacterial diseases. Therefore, the aim of this study was to evaluate the bactericidal activity of copaiba oil, Copaifera duckei, against Streptococcus agalactiae and Flavobacterium columnare and the dietary effect of copaiba oil on zootechnical performance, hematological, biochemical, immunological, and histological analysis before and after an intraperitoneal infection (body cavity) with S. agalactiae in Nile tilapia. For this, fish were randomly distributed into 15 fiber tanks in five treatments (0, 0.25, 0.50, 0.75, and 1.0%) and fed with a commercial diet supplemented with copaiba oil for 30 days. After this period, the fish were randomly redistributed for the experimental challenge with S. agalactiae into six treatments (T0, T1, T2, T3, T4, and T5), the fish were anesthetized, and blood samples were collected to assess hematological, biochemical, immunological, and histological parameters. Copaiba oil showed bactericidal activity against Streptococcus spp. and Flavobacterium spp. in vitro. In addition, concentrations of 0.75 and 1.0% of copaiba oil have an anti-inflammatory effect and improve hematological and immunological parameters, increasing leukocyte numbers, albumin, and serum lytic activity. Furthermore, there is an increase in the intestinal villus length and tissue damage in groups at concentrations of 0.75 and 1.0% of copaiba oil. In conclusion, copaiba oil presented bactericidal activity against Streptococcus spp. and Flavobacterium spp. in vitro, and oral supplementation at concentrations of 0.75 and 1.0% compared to the control group enhanced non-specific immune parameters and digestibility in Nile Tilapia.

Chemical contamination affecting filter-feeding bivalves in no-take marine protected areas from Brazil

Marine protected areas (MPAs) are zones geographically delimited under pre-defined management goals, seeking to reduce anthropogenic threats to biodiversity. Despite this, in recent years reports of MPAs affected by chemical contamination has grown. Therefore, this study addresses this critical issue assessing legacy and current chemical contamination in filter-feeder bivalves obtained in very restrictive no-take MPAs from Brazil. The detected pollutants encompass polycyclic aromatic hydrocarbons (PAHs), linear alkylbenzenes (LABs), and persistent organic pollutants (POPs) like dichlorodiphenyltrichloroethane (DDTs) and polychlorinated biphenyls (PCBs). Despite protective measures, bivalves from nine MPAs exhibited high LABs (13.2-1139.0 ng g-1) and DDTs levels (0.1-62.3 ng g-1). PAHs were present in low concentrations (3.1-29.03 ng g-1), as PCBs (0.7-6.4 ng g-1), hexachlorobenzene (0.1-0.2 ng g-1), and Mirex (0.1-0.3 ng g-1). Regardless of the sentinel species, MPAs and management categories, similar accumulation patterns were observed for LABs, DDTs, PAHs, and PCBs. Based on the limits proposed by Oslo Paris Commission, the measured levels of PAHs, PCBs and were below the environmental assessment criteria. Such findings indicate the no biological effects are expected to occur. However, they are higher considering background conditions typically measured in remote or pristine areas and potential simultaneous exposure. Such findings indicate an influence of anthropogenic sources, emphasizing the urgency for monitoring programs guiding strategic management efforts to safeguard these areas.

The EU Interreg Project "ADRINET": Assessment of Well-Known and Emerging Pollutants in Seafood and Their Potential Effects for Food Safety

Anthropogenic activities lead to the spread of chemicals and biological materials, including plastic waste, toxic metals, and pharmaceuticals, of which the impact on the Mediterranean Sea is of high concern. In this context, the EU Interreg Italy-Albania-Montenegro Project "ADRINET (Adriatic Network for Marine Ecosystem) _244" (2018-2020) arises. It aims to carry out biomonitoring campaigns in the main commercial interest of fish and cephalopod species, such as Sparus aurata, Dicentrarchus labrax, Sepia spp., and Loligo spp. sampled in three different subregions of the Mediterranean Sea. The presence of the main environmental contaminants, such as cadmium, microplastics, and antibiotics was investigated in these seafood samples. Contamination by cadmium and antibiotics in the seafood investigated in our study was negligible. However, a high value of microplastics was detected in the stomach and gut of Sparus aurata and Dicentrarchus labrax. Overall, even though the presence of microplastics needs to be investigated by further studies, the results confirmed that the environmental conditions of the three bays investigated by the ADRINET project partners (Italy, Albania, Montenegro) are positive and not affected by intensive anthropogenic activity.

Contaminants of Emerging Concern: Antibiotics Research in Mussels from the Coasts of the Tyrrhenian Sea (Sardinia, Italy)

Contaminants of emerging concern (CECs) are compounds found in several environmental compartments whose ubiquitous presence can cause toxicity for the entire ecosystem. Several personal care products, including antibiotics, have entered this group of compounds, constituting a major global threat. It is essential to develop simple and reliable methods by which to quantify these contaminants in several matrices. In this work, mussels were chosen as sentinel organisms to assess environmental pollution and the safety of bivalve mollusk consumption according to the "One Health perspective". A liquid chromatographic tandem mass spectrometry method (LC-MS/MS) was developed for the quantification of two macrolides, erythromycin (ERY) and azithromycin (AZI), in mussels. This new method was validated according to international guidelines, showing high selectivity, good recoveries (>60% for both of them), sensitivity, and precision. The method was successfully applied for ERY and AZI research in mussels farmed along the Sardinian coasts (Italy), demonstrating itself to be useful for routine analysis by competent authorities. The tested macrolides were not determined in the analyzed sites at concentrations above the limits of detection (LODs). These results demonstrate the food safety of mussels (as concerns the studied antibiotics) and a negligible amount of pollution derived from these drugs in the studied area.

Distribution and Probabilistic Risk Assessment of Antibiotics, Illegal Drugs, and Toxic Elements in Gastropods from Southeast China

We investigated fourteen antibiotics, three illegal drugs, and two toxic elements in commercially available gastropods from southeast China. The data revealed high detection frequencies (DFs) for florfenicol (61.32%), florfenicol amine (47.33%), and thiamphenicol (39.88%), with maximum concentrations of 1110, 2222, and 136 μg/kg wet weight (ww), respectively. The DFs of illegal drugs were 3.54% for leucomalachite green and 0.3% for chloramphenicol. The average levels of Cd and As were 1.17 and 6.12 mg/kg ww, respectively. All chemicals presented diverse DFs in different sampling months. The highest DFs of florfenicol, florfenicol amine, and thiamphenicol were in July. The health risk assessment showed that targeted hazard quotients (THQs) of antibiotics, Cd, and As for children, teens, and adults were all less than one. Notably, the toxic elements (Cd and As) were identified as the primary health risk in gastropods, contributing to over 90% of the total THQs.

An update on the prevalence of colistin and carbapenem-resistant Gram-negative bacteria in aquaculture: an emerging threat to public health

Aquaculture has been recognized as a hotspot for the emergence and spread of antimicrobial resistance genes conferring resistance to clinically important antibiotics. This review gives insights into studies investigating the prevalence of colistin and carbapenem resistance (CCR) among Gram-negative bacilli in aquaculture. Overall, a high incidence of CCR has been reported in aquatic farms in several countries, with CCR being more prevalent among opportunistic human pathogens such as Acinetobacter nosocomialis, Shewanella algae, Photobacterium damselae, Vibrio spp., Aeromonas spp., as well as members of Enterobacteriaceae family. A high proportion of isolates in these studies exhibited wide-spectrum profiles of antimicrobial resistance, highlighting their multidrug-resistance properties (MDR). Several mobile colistin resistance genes (including, mcr-1, mcr-1.1, mcr-2, mcr-2.1, mcr-3, mcr-3.1, mcr-4.1, mcr-4.3, mcr-5.1, mcr-6.1, mcr-7.1, mcr-8.1, and mcr-10.1) and carbapenemase encoding genes (including, blaOXA-48, blaOXA-55, blaNDM, blaKPC, blaIMI, blaAIM, blaVIM, and blaIMP) have been detected in aquatic farms in different countries. The majority of these were carried on MDR Incompatibility (Inc) plasmids including IncA/C, and IncX4, which have been associated with a wide host range of different sources. Thus, there is a risk for the possible spread of resistance genes between fish, their environments, and humans. These findings highlight the need to monitor and regulate the usage of antimicrobials in aquaculture. A multisectoral and transdisciplinary (One Health) approach is urgently needed to reduce the spread of resistant bacteria and/or resistance genes originating in aquaculture and avoid their global reach.

Integrated analysis of marine biotoxins and contaminants of emerging concern in bivalve mollusks from Santa Catarina, Brazil

Santa Catarina is the main producer state of oysters and mussels in Brazil, reaching 98 % of national production. To assure the safety of bivalve mollusks production, control programs of marine biotoxins (MBs) have been continuously performed. Herein, the co-occurrence of MBs and contaminants of emerging concern (CECs) in oyster and mussels from the main production sites of Santa Catarina was reported, covering 178 compounds. Samples of wild and non-cultivated oysters and mussels were also assessed. Chemometric tools were used to evaluate and optimize several sample preparation techniques such as solid-liquid, ultrasound assisted, and pressurized liquid extraction. The optimized protocol was based on ultrasound assisted extraction followed by liquid chromatography coupled to tandem mass spectrometry. The results showed the incidence of several CECs and MBs. In the case of MBs, all results were below the regulatory limits for both cultivated and non-cultivated samples. Wild mollusks have shown a higher number of compounds. Regarding CECs, the more frequent compounds were caffeine, diclofenac, meloxicam, and sertraline. Domoic acid and okadaic acid were the main toxins detected. The results highlighted the need of monitoring for MBs and the potential of oyster and mussels as sentinel organisms to risk analysis of CECs in coastal regions. To the best of our knowledge, this is the first method to describe a simultaneous sample preparation and analysis of CECs and MBs in bivalve mollusks, as well as the first report of meloxicam and florfenicol in mussels and oysters.

Management and Mitigation of Vibriosis in Aquaculture: Nanoparticles as Promising Alternatives

Vibriosis is one of the most common diseases in marine aquaculture, caused by bacteria belonging to the genus Vibrio, that has been affecting many species of economically significant aquatic organisms around the world. The prevention of vibriosis in aquaculture is difficult, and the various treatments for vibriosis have their limitations. Therefore, there is an imperative need to find new alternatives. This review is based on the studies on vibriosis, specifically on the various treatments and their limitations, as well as the application of nanoparticles in aquaculture. One of the promising nanoparticles is graphene oxide (GO), which has been used in various applications, particularly in biological applications such as biosensors, drug delivery, and potential treatment for infectious diseases. GO has been shown to have anti-bacterial properties against both Gram-positive and Gram-negative bacteria, but no research has been published that emphasizes its impact on Vibrio spp. The review aims to explore the potential use of GO for treatment against vibriosis.

Seahorse Male Pregnancy as a Model System to Study Pregnancy, Immune Adaptations, and Environmental Effects

Seahorses, together with sea dragons and pipefishes, belong to the Syngnathidae family of teleost fishes. Seahorses and other Syngnathidae species have a very peculiar feature: male pregnancy. Among different species, there is a gradation of paternal involvement in carrying for the offspring, from a simple attachment of the eggs to the skin surface, through various degrees of egg coverage by skin flaps, to the internal pregnancy within a brood pouch, which resembles mammalian uterus with the placenta. Because of the gradation of parental involvement and similarities to mammalian pregnancy, seahorses are a great model to study the evolution of pregnancy and the immunologic, metabolic, cellular, and molecular processes of pregnancy and embryo development. Seahorses are also very useful for studying the effects of pollutants and environmental changes on pregnancy, embryo development, and offspring fitness. We describe here the characteristics of seahorse male pregnancy, its regulatory mechanisms, the development of immune tolerance of the parent toward the allogeneic embryos, and the effects of environmental pollutants on pregnancy and embryo development.

Extraction method for the multiresidue analysis of legacy and emerging pollutants in marine mussels from the Adriatic Sea

The release of hazardous chemicals into aquatic environments has long been a known problem, but its full impact has only recently been realized. This study presents a validated liquid chromatography-mass spectrometry (HPLC-MS/MS) method for detecting pharmaceutical and pesticide residues in mussels (Mytilus galloprovincialis). An innovative MS-compatible extraction method was developed and validated, demonstrating successful recovery rates for analytes at three different concentration levels (25-95%). The method detected the target analytes at ng/g concentrations with high accuracy (-7% to 11%) and low relative standard deviation (<10%) for both intra-day and inter-day analyses. After validation, the method was applied to mussel samples collected from a commercial farm near Senigallia, Adriatic Sea, detecting different contaminants in the range of 2-40 ng/g (dry weight). The study provides a valuable tool for investigating the potential threats posed by diverse contaminant classes with high annual tonnage, including analytes with known persistence and/or illegal status.

Analysis of Antibiotics in Bivalves by Ultra-High Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry

The presence of pharmaceuticals in aquatic ecosystems mostly originates from wastewater treatment plants (WWTPs) and such a situation can be responsible for significant negative impacts on natural ecosystems, such as estuarine and coastal areas. Bioaccumulation of pharmaceuticals, namely antibiotics, in exposed organisms is known to have remarkable effects on different trophic levels of non-target organisms such as algae, invertebrates and vertebrates, including the emergence of bacterial resistance. Bivalves are a highly appreciated seafood product, as they are fed by filtering water, and can bioconcentrate chemicals, being ideal for biomonitoring environmental health hazards in coastal and estuarine ecosystems. To use this sentinel species, an analytical strategy was developed to be used in accessing antibiotics, from human and veterinary medicine, and evaluate their occurrence as emerging pollutants in aquatic environments. The optimized analytical method was fully validated according to the European requirements defined by the Commission Implementing Regulation 2021/808. The validation comprised the following parameters: specificity, selectivity, precision, recovery, ruggedness, linearity, and the decision limit CCα, as well as the limit of detection (LoD) and limit of quantification (LoQ). The method was validated for 43 antibiotics to allow their quantification in both contexts, environmental biomonitoring and food safety.

Antimicrobial Susceptibility of Bacteria Isolated from Freshwater Mussels in the Wildcat Creek Watershed, Indiana, United States

Antimicrobial resistance (AMR) is a global health crisis that threatens the health of humans and animals. The spread of resistance among species may occur through our shared environment. Prevention of AMR requires integrated monitoring systems, and these systems must account for the presence of AMR in the environment in order to be effective. The purpose of this study was to establish and pilot a set of procedures for utilizing freshwater mussels as a means of surveillance for microbes with AMR in Indiana waterways. One hundred and eighty freshwater mussels were sampled from three sites along the Wildcat Creek watershed in north-central Indiana. Specimens were evaluated for the presence of ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species), Escherichia coli, Campylobacter, and Salmonella species, and the isolates were tested for antimicrobial resistance. A total of 24 bacterial isolates were obtained from tissue homogenates of freshwater mussels collected at a site directly downstream from Kokomo, Indiana. Of these, 17 were Enterobacter spp., five were Escherichia coli, one was Pseudomonas aeruginosa, and one was Klebsiella pneumoniae. All isolates were resistant to three or more antimicrobial drug classes. Further work is necessary to determine the source of the bacterial species found in the mussels.

Microbial profiles and immune responses in seahorse gut and brood pouch under chronic exposure to environmental antibiotics

Ocean antibiotics pose substantial risks to the adaptation and lifespan of marine organisms. Seahorses are unique owing to the occurrence of brood pouches, male pregnancy, and loss of gut-associated lymphatic tissues and spleen, which lead to increased sensitivity to environmental changes. This study evaluated the changes in microbial diversity and immune responses within the gut and brood pouch in the lined seahorse Hippocampus erectus under chronic exposure to environmental levels of triclosan (TCS) and sulfamethoxazole (SMX), which are common antibiotics in coastal regions. The results showed that microbial abundance and diversity within the gut and brood pouch of seahorses were significantly changed following antibiotics treatment, with the expression of core genes involved in immunity, metabolism, and circadian rhythm processes evidently regulated. Notably, the abundance of potential pathogens in brood pouches was considerably increased upon treatment with SMX. Transcriptome analysis revealed that the expression of toll-like receptors, c-type lectins, and inflammatory cytokine genes in brood pouches was significantly upregulated. Notably, some essential genes related to male pregnancy significantly varied after antibiotic treatment, implying potential effects on seahorse reproduction. This study provides insights into the physiological adaptation of marine animals to environmental changes resulting from human activity.

Occurrence and seasonal variation of plasticizers in sediments and biota from the coast of Mahdia, Tunisia

Plasticizers are compounds often involved in the manufacturing of plastic products. Nevertheless, the ageing of the latter generates plasticizers that generally end up in the marine environment. In fact, marine pollution by phthalate acid esters (PAEs) and their alternatives has become an environmental and health issue of serious concern, as they are largely and ubiquitously present in the environment and aquatic organisms. In the present study, four PAEs, such as diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), and one non-phthalate plasticizer (NPP), namely di-2-ethylhexyl terephthalate (DEHT), are wanted in different marine compartments from the coast of Mahdia in Tunisia such as sediment, seagrass, and mussel. The most abundant and frequently detected congener was DEHT at the concentrations reached 1.181 mg/kg in the sediment, 1.121 mg/kg in the seagrass, and 1.86 mg/kg in the mussel. This result indicates that the DEHT could emerge through the food chain and therefore bioaccumulate in marine compartments. In addition, we noticed that the seasonal variations of plasticizers were seriously affected by environmental factors including industrial and urban discharges.

Molluscs-A ticking microbial bomb

Bivalve shellfish consumption (ark shells, clams, cockles, and oysters) has increased over the last decades. Following this trend, infectious disease outbreaks associated with their consumption have been reported more frequently. Molluscs are a diverse group of organisms found wild and farmed. They are common on our tables, but unfortunately, despite their great taste, they can also pose a threat as a potential vector for numerous species of pathogenic microorganisms. Clams, in particular, might be filled with pathogens because of their filter-feeding diet. This specific way of feeding favors the accumulation of excessive amounts of pathogenic microorganisms like Vibrio spp., including Vibrio cholerae and V. parahaemolyticus, Pseudomonas aeruginosa, Escherichia coli, Arcobacter spp., and fecal coliforms, and intestinal enterococci. The problems of pathogen dissemination and disease outbreaks caused by exogenous bacteria in many geographical regions quickly became an unwanted effect of globalized food supply chains, global climate change, and natural pathogen transmission dynamics. Moreover, some pathogens like Shewanella spp., with high zoonotic potential, are spreading worldwide along with food transport. These bacteria, contained in food, are also responsible for the potential transmission of antibiotic-resistance genes to species belonging to the human microbiota. Finally, they end up in wastewater, thus colonizing new areas, which enables them to introduce new antibiotic-resistance genes (ARG) into the environment and extend the existing spectrum of ARGs already present in local biomes. Foodborne pathogens require modern methods of detection. Similarly, detecting ARGs is necessary to prevent resistance dissemination in new environments, thus preventing future outbreaks, which could threaten associated consumers and workers in the food processing industry.

An Overview of Antibiotics as Emerging Contaminants: Occurrence in Bivalves as Biomonitoring Organisms

Simple Summary

In recent years, the use of antibiotics has increased worldwide in both human and veterinary fields. This led to them accumulating in the environment to such an extent that they are actually included in the category of contaminants of emerging concern. For this reason, many of them have been included in monitoring lists of potential pollutants by competent authorities in order to limit their concentration in surface waters and to determine the risk to the aquatic environments. From this perspective, the aim of this review is to update and discuss the available data on antibiotic residues, using bivalves as biomonitoring organisms. Bivalves are good candidate for this purpose, being globally present in large and accessible populations, sedentary and able to accumulate several xenobiotics thanks to their large filtration capacity. The current research indicates that antibiotics’ presence in bivalves has been investigated along European, American and Asian coasts. Except for tetracycline, determined at high concentration in the North Adriatic Sea, all antibiotics residues in bivalves were under the maximum residual limit established by the competent authorities. Nevertheless, further investigations are necessary in order to prevent antimicrobial resistance, preserve the environment from antibiotic pollution and monitor the associated risk for animals and humans.

Abstract

Antibiotics are used for therapeutic and prophylactic purposes in both human and veterinary medicine and as growth promoting agents in farms and aquaculture. They can accumulate in environmental matrices and in the food chain, causing adverse effects in humans and animals including the development of antibiotic resistance. This review aims to update and discuss the available data on antibiotic residues, using bivalves as biomonitoring organisms. The current research indicates that antibiotics’ presence in bivalves has been investigated along European, American and Asian coasts, with the majority of studies reported for the last. Several classes of antibiotics have been detected, with a higher frequency of detection reported for macrolides, sulfonamides and quinolones. The highest concentration was instead reported for tetracyclines in bivalves collected in the North Adriatic Sea. Only oxytetracycline levels detected in this latter site exceeded the maximum residual limit established by the competent authorities. Moreover, the risk that can be derived from bivalve consumption, calculated considering the highest concentrations of antibiotics residues reported in the analyzed studies, is actually negligible. Nevertheless, further supervisions are needed in order to preserve the environment from antibiotic pollution, prevent the development of antimicrobial resistance and reduce the health risk derived from seafood consumption.

Correlation of phytoplankton satellite observations and radiological doses in molluscs

In this work data of salinity, temperature, suspended particulate matter (SPM), chlorophyll-a, and phytoplankton concentration in the Gibraltar Strait coast, in the confluence of the Mediterranean Sean and the Atlantic Ocean, were analyzed together with ²¹⁰Po, ⁴⁰K, ²¹⁰Pb and ²³⁴Th activity concentration in different types of bivalve molluscs at the same time-period. The physicochemical parameters were evaluated using the Copernicus Marine Environment Monitoring Service (CMEMS) products based on satellite observations. A multivariate statistical analysis, including contrasted natural radioactivity contents, allowed the discrimination of bivalve molluscs from Atlantic and Mediterranean coasts. Additionally, a cluster analysis determined a highly significant negative correlation ²¹⁰Po concentration in molluscs and phytoplankton concentration suggesting that phytoplankton concentration in the water column is a determinant factor to regulate ²¹⁰Po concentration in those animals. These results introduce a useful tool to calculate the radiological doses in seafood from chlorophyll satellite image.

Assessing the Bacterial Community Composition of Bivalve Mollusks Collected in Aquaculture Farms and Respective Susceptibility to Antibiotics

Aquaculture is a growing sector, providing several products for human consumption, and it is therefore important to guarantee its quality and safety. This study aimed to contribute to the knowledge of bacterial composition of Crassostrea gigas, Mytilus spp. and Ruditapes decussatus, and the antibiotic resistances/resistance genes present in aquaculture environments. Two hundred and twenty-two bacterial strains were recovered from all bivalve mollusks samples belonging to the Aeromonadaceae, Bacillaceae, Comamonadaceae, Enterobacteriaceae, Enterococcaceae, Micrococcaceae, Moraxellaceae, Morganellaceae, Pseudomonadaceae, Shewanellaceae, Staphylococcaceae, Streptococcaceae, Vibrionaceae, and Yersiniaceae families. Decreased susceptibility to oxytetracycline prevails in all bivalve species, aquaculture farms and seasons. Decreased susceptibilities to amoxicillin, amoxicillin/clavulanic acid, cefotaxime, cefoxitin, ceftazidime, chloramphenicol, florfenicol, colistin, ciprofloxacin, flumequine, nalidixic acid and trimethoprim/sulfamethoxazole were also found. This study detected six qnrA genes among Shewanella algae, ten qnrB genes among Citrobacter spp. and Escherichia coli, three oqxAB genes from Raoultella ornithinolytica and bla_TEM-1 in eight E. coli strains harboring a qnrB19 gene. Our results suggest that the bacteria and antibiotic resistances/resistance genes present in bivalve mollusks depend on several factors, such as host species and respective life stage, bacterial family, farm’s location and season, and that is important to study each aquaculture farm individually to implement the most suitable measures to prevent outbreaks.

Bisphenols' occurrence in bivalves as sentinel of environmental contamination

Bisphenols are massively used in several manufacture processes such that bisphenol A (BPA) is ubiquitous in environment worldwide. After the implementation of regulations about BPA use, manufacturers have moved their production toward alternative substances structurally similar to it. Unfortunately, BPA analogues, given their structural similarity, exert also similar adverse effects. This review aims to investigate the occurrence of bisphenols (BPs) in bivalve molluscs. In this way, valuable information on the amount of BPs released into the environment in different areas are given. The current research indicates that BPA presence in bivalve molluscs has been investigated in Asia (Indian Ocean and Pacific Ocean), Europe (Mediterranean Sea, Baltic Sea and Atlantic Ocean) and America (Lake Mead, Nevada) with the highest amount of studies reported in bivalves harvested in Asian Coasts. BPA analogues are frequently detected in several matrices and their levels will continuously increase in the environment. Nevertheless, there is a current lack of studies analysing BPs other than BPA in bivalves. Further investigations should be conducted in this direction, in order to assess environmental distribution and the hazard for animals and human health given that seafood consumption could be an important pathway of bisphenols intake.

Sulfamethoxazole induced systematic and tissue-specific antioxidant defense in marine mussels (Mytilus galloprovincialis): Implication of antibiotic's ecotoxicity

Sulfamethoxazole (SMX), recognized as emerging pollutant, has been frequently detected in aquatic environment. However, effects induced by SMX and the underneath mechanism on non-target aquatic organisms, marine mussels (Mytilus galloprovincialis), are still largely unknown. In present study, marine mussels were exposed to SMX (nominal concentrations 0.5, 50 and 500 μg/L) for 6 days, followed by 6 days depuration and responses of antioxidant defenses, e.g. superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST), etc., at transcriptional, translational and functional levels were evaluated in two vital tissues, gills and digestive glands. Results showed SMX can be accumulated in mussels while the bio-accumulative ability was low under the experimental condition. A systemic but not completely synchronous antioxidant defense at different levels upon SMX exposure. The transcriptional alteration was more sensitive and had the potential to be used as early warning of SMX induced ecotoxicity. Complementary function of antioxidant enzymes with specific alteration of metabolism related gene (gst) suggested that further researches should focused on SMX metabolism and SMX induced effects simultaneously. Significant tissue-specific antioxidant responses were discovered and gills showed earlier and quicker reacting ability than digestive glands, which was closely related to the functional diversity and different thresholds of xenobiotics allowance.

Occurrence of antibiotics and antibiotic resistance genes and their correlations in river-type drinking water source, China

The occurrence and distribution of antibiotics and antibiotic resistance genes (ARGs) in natural water has attracted worldwide attention. Antibiotic and ARG pollution in the surface water of drinking water sources might directly/indirectly affect human health. In this study, the distribution of 38 antibiotics, 10 ARGs, 2 integrons, and 16S r DNA in river-type water sources in a large city of China were monitored in winter, which was a period with high level of antibiotic pollution. The results showed that 20 antibiotics were detected with different detection frequencies. The antibiotic pollution in December 2019 was relatively high, with the total concentrations of antibiotics ranging from 281.95 to 472.42 ng/L, followed by that in January 2020 (191.70-337.29 ng/L) and November 2019 (161.25-309.72 ng/L). Sulfacetamide was dominant in November 2019 (23.52-219.00 ng/L) and in January 2020 (113.18-209 ng/L), while norfloxacin in December 2019 (146.72-290.20 ng/L). All the target antibiotics posed low or medium risk for aquatic organisms, and posed low health risk for mankind. Sul1 and erm36 were the predominant ARGs, and intI1 was the predominant integron in drinking water sources. Only tetA showed positive correlations with its corresponding antibiotic (tetracycline). The rest of ARGs showed no correlations with antibiotics or positive / negative correlations with their non-corresponding antibiotics. Overall, the antibiotics and ARG pollution in these water sources was relatively low. These findings provided some reference data for the distribution of antibiotics and ARGs in river-type drinking water sources of large cities in China.

Occurrence of common plastic additives and contaminants in mussel samples: Validation of analytical method based on matrix solid-phase dispersion

A new matrix solid-phase dispersion (MSPD) extraction methodology, combined with high-performance liquid chromatography equipped with a diode-array detector, was developed and validated for the simultaneous determination of 10 compounds in mussels from Galician Rias (Spain). These pollutants are compounds commonly used for plastic production as additives, as well as common plastic contaminants. The compounds selected were bisphenol-A, bisphenol-F, bisphenol-S, nonylphenol-9, nonylphenol, diethyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethane, and dichlorodiphenyldichloroethylene. The parameters affecting the MSPD extraction efficiency such as the type of sorbent, mass sample-sorbent ratio, and extraction solvent were optimised. The proposed method provided satisfactory quantitative recoveries (80-100%), with relative standard deviations lower than 7%. In all cases, the matrix-matched calibration curves were linear in the concentration range of 0.32-120.00 µg/kg, with quantification limits of 0.25-16.20 µg/kg. The novel developed MSPD-high-performance liquid chromatography methodology provided good sensitivity, accuracy, and repeatability for quality control analysis in mussels.

Emerging contaminants detected in aquaculture sites in Java, Indonesia

Pharmaceuticals of emerging concern (acetaminophen (ACM), trimethoprim (TMP), oxytetracycline (OTC), and sulfamethoxazole (SMX)) were detected in water samples from aquaculture environments and nonaquaculture sites in four regions located on the northern coast of Central Java. ACM was the most prevalent pharmaceutical, with a mean concentration ranging from not detected (n.d.) to 5.5 ± 1.9 ngL^-1 (Brebes). Among the target antibiotics (TMP, OTC, SMX), OTC was the most ubiquitous, with a mean concentration varying from n.d. to 8.0 ± 3.3 ngL^-1. Correlation analysis demonstrated that there was a significant correlation between TMP and SMX concentrations. Based on ecological risk assessment evaluation, the use of OTC requires serious consideration, as it presented high health risks to algae, while ACM, TMP, and SMX posed an insignificant to moderate risk to algae, invertebrates, and fish. The findings obtained from this study highlight OTC as an emerging contaminant of prominent concern. More attention needs to be given to managing and planning for the sustainable management of shrimp farms, particularly in the northern part of Central Java.

Bioaccessibility evaluation of pharmaceuticals in market fish with in vitro simulated digestion

The consumption of pharmaceuticals-contaminated aquatic products could pose risks to human health, and risk assessments considering bioaccessibility can provide better dietary recommendations. In this study, the bioaccessibility of 6 pharmaceuticals (sulfadiazine (SD), sulfapyridine (SPD), roxithromycin (ROX), tylosin (TYL), diclofenac (DIC) and carbamazepine (CMZP)) in several fish species collected from Shanghai markets was evaluated using in vitro simulated digestion. The total mixed pharmaceuticals concentration in freshwater fish were lower than those in marine fish, and statistics showed that the total concentrations of SD, SPD and CMZP in freshwater fish were significantly lower than those of marine fish (p < 0.05). The bioaccessible concentration of each pharmaceutical accounted for 26.3% (TYL) to 101.5% (CMZP) of the total concentration in market fish (n = 70). The bioaccessibility of 6 pharmaceuticals in species of fish was 18.8% (cutlassfish) to 99.6% (bream), which may be related to the physical-chemical properties of the pharmaceutical and the characteristics of the matrix (e.g. lipid content). According to health risk assessments, the consumption of market fish in Shanghai posed no remarkable risk to human health (hazard quotient < 0.099). Ignoring the bioaccessibility of pharmaceuticals in aquatic products might overestimate the human health risks by dietary exposure.

A reusable QCR aptasensor for the detection of Brevetoxin-2 in shellfish

Brevetoxins (BTX) are pharmacologically active, lipid soluble cyclic polyether neurotoxins that are known to cause a wide range of neurological symptoms in humans.Harvesting and consumption of infected molluscs provide an entry point for BTXs into, the food chain, causing long-term health effects on accumulation for individuals, commonly in people with a compromised immune system and existing allergies. This study is an acoustic assay that has been constructed using a 9 MHz AT-cut quartz crystal resonator modified by attaching a specific single-stranded DNA aptamer. The DNA oligo modifies its conformation to attach itself to the binding site of the incoming BTX molecule resulting in a change in frequency on the QCR. A small Δf value was observed for lower concentrations of BTX indicating a small change in mass deposited on the crystal surface, while the opposite was true for higher concentrations. Cross-species behavior was evaluated using samples of similar origin, molecular weight and a combination of two toxins. The LOD of the fabricated QCR is 220 nM which is lower than the maximum recommended residue limit in food samples. Fresh mussel samples were spiked with known concentrations of BTX to evaluate its sensitivity in a food matrix. No interaction with other compounds was observed. Overall, this sensor finds potential application in the food sector (fishing units) where mussels are tested and graded for allergens and toxins before reaching the customer.

Microbial community composition and antimicrobial resistance in agricultural soils fertilized with livestock manure from conventional farming in Northern Italy

Antimicrobials are commonly used in conventional livestock production and manure is widely applied to agricultural lands as fertilizer. This practice raises questions regarding the effects of fertilization on (i) soil microbiota composition and (ii) spread of antimicrobials and antimicrobial resistance (AMR) in the environment. This study was conducted in a high-density farming area of Northern Italy and aimed at assessing the impact of (dairy cattle, chickens and swine) manure application on soil microbiome, antimicrobial concentrations and antimicrobial resistance gene (ARG) abundance. We found the microbial community composition in manure to be different and less diverse than in soil, with manure application altering only marginally the soil microbiome. Exceptions were the phyla Firmicutes, Tenericutes and Cloacimonetes, which significantly enriched in fertilized soil. Of the antimicrobials investigated, only flumequine concentrations increased after manure application, albeit non-significantly. ARGs were more abundant in manure, with ermA, ermB, bla_OXA-1 and oqxA being significantly enriched in fertilized soil. Positive correlations between oqxA and qnrS abundances and flumequine concentrations were observed, together with the co-occurrence of some ARGs and microbial taxa (e.g. oqxA correlated with Acidobacteria and Gemmatimonadetes). This study showed that manure application has little effect on soil microbiome but may contribute to the dissemination of specific ARGs into the environment. Moreover, flumequine residues seem to enhance the emergence of oqxA and qnrS in soil.

Trace Analysis of Multiclass Antibiotics in Food Products by Liquid Chromatography-Tandem Mass Spectrometry: Method Development

It is commonly known that the widespread use of antibiotics has led to their existence in food products as residues and ingestion of these food products may create a selection pressure on bacteria inhabiting the human body. In this study, an optimized method for the analysis of antibiotic residues in different food groups, including cereals, meat, eggs, milk, vegetables, and fruits, was developed using solvent extraction, solid-phase extraction cleanup, and liquid chromatography-mass spectrometry (LC-MS/MS). The limits of detection (LODs) were achieved as 0.007-1.1, 0.008-0.46, 0.002-0.67, 0.007-0.63, 0.001-0.098, and 0.005-0.26 ng/g in ng/g in cereals, meat, eggs, milk, vegetables, and fruits, respectively. The overall average recoveries at three spiking levels of the 81 antibiotics (5, 25, and 50 ng/g dry weight) were 82 ± 26, 77 ± 26, 70 ± 34, 69 ± 31, 73 ± 29, and 62 ± 37% in cereals, meat, eggs, milk, vegetables, and fruits, respectively. The method was then applied to the analysis of the targets in the collected wheat flour, mutton, chicken egg, boxed milk, cabbage, and banana samples, with the total concentration of the antibiotics detected being 4.4, 2.3, 36, 5.5, 2.7, and 14 ng/g, respectively. This work suggests that the developed method provides a time- and cost-effective method to identify and quantify antibiotic residues in common food products.

Discrimination between Fresh and Frozen-Thawed Fish Involved in Food Safety and Fraud Protection

This study aims to discriminate fresh fish from frozen/thawed by identification of the key metabolites that are altered during the freezing/thawing processing. Atlantic salmon (Salmo salar) and bullet tuna (Auxis rochei) were selected as they are representative of broad consumption, and susceptible to pathogen contamination. Atlantic salmon samples were subjected to the following regimes: −20 °C (24h) and −35 °C (15 h) freezing, then thawed respectively in the blast chiller and in the cold room and analyzed immediately or after 10 days; (2) bullet tuna samples were frozen at −18 °C and thawed after 15, 30 and 90 days. High resolution mass spectrometry based on untargeted metabolomic analyses and statistical data treatment confirmed significant variations in the quantity of certain metabolites: the amount of l-phenylalanine in salmon increased immediately after thawing while that of anserine decreased. The concentration of l-arginine and its metabolites was altered at the 10th day after thawing rendering them promising markers of salmon freezing/thawing. As regards bullet tuna, compounds resulting from lipid degradation (l-α-Glyceryl-phosphoryl-choline and N-methyl-ethanolamine phosphate) increased notably during the storage period. This approach could be used to reveal common fraudulent incidents such as deliberate replacement of fresh fish with frozen/thawed, with food safety risks as the primary implication.

Cytotoxic responses of the anticancer drug cyclophosphamide in the mussel Mytilus galloprovincialis and comparative sensitivity with human cells lines

The rise of cancer cases worldwide led to an increase in production and consumption of anticancer drugs, that ultimately end up in the marine environment and are accumulated in aquatic organisms. Cyclophosphamide (CP) is a cytotoxic alkylating agent frequently prescribed in cancer treatments. This study assess ecotoxicological effects of CP on mussels Mytilus galloprovincialis, through in vivo and ex vivo approaches and compares the sensitivity of mussel haemocytes with well-established human cell lines (RPE and HeLa). Mussels were exposed in vivo to CP (1000 ng L^-1) and several biomarkers analysed in gills and digestive glands namely neurotoxicity (AChE activity), oxidative stress (GPx activity), biotransformation (GST activity), lipid peroxidation (LPO) and apoptosis (caspase activity), whereas genotoxicity was determined in mussels' haemocytes. Cytotoxicity was also assessed in haemocytes (in vivo and ex vivo) and human cell lines (in vitro) exposed to a range of CP concentrations (50, 100, 250, 500 and 1000 ng L^-1) over 24 h, via neutral red assay. In in vivo exposure, detoxification of CP did not efficiently occur in the gills while in digestive glands GPx and GST activities were induced, jointly with a decrease in lipid peroxidation, indicating a potential outcome of the protective antioxidant mechanisms, whereas no apoptosis was noted. Moreover, cytotoxicity and DNA damage were detected in haemocytes. The ex vivo exposure haemocytes to CP caused cytotoxicity (from 100 ng L^-1), whereas no effects occurred in human cell lines. This suggests that, at relevant environmental concentrations, CP cause subtle and irreversible impacts on M. galloprovincialis.

Efficient degradation of lomefloxacin by Co-Cu-LDH activating peroxymonosulfate process: Optimization, dynamics, degradation pathway and mechanism

In this study, bimetal layered double hydroxides (Co_xCu_y-LDHs) containing a carbonate interlayer were synthesized using coprecipitation with a variety of Co/Cu mole ratios. Meanwhile, the corresponding layered double oxides (Co_xCu_y-LDOs) were prepared as controls. In this study, Electrical energy per order was performed to evaluate economic analysis. Correspondingly, we found that Co_xCu_y-LDHs possessed a significantly better PMS activation capability than the corresponding metal oxide composite (Co₃O₄/CuO). Compared with other Co_xCu_y-LDHs, Co₂Cu₁ LDH possessed the best PMS activation capability for LOM degradation and the lowest electrical energy per order (EE/O) value during the reaction. Additionally, Co₂Cu₁ LDH presented an excellent stability and worked over a wide pH range. The hydroxide states of Co(III), Co(II), Cu(I) and Cu(II) were all able to activate PMS, indicating that there were many active sites on the surface of Co₂Cu₁ LDH. The involvement of radicals in this reaction system was determined via scavenger experiments and electron paramagnetic resonance (EPR). Meanwhile, it's worth noting that a mathematical model was developed to quantify the involvement of SO₄^- and OH. Subsequently, we determined PMS activation mechanism and LOM decomposition pathway for the PMS/Co₂Cu₁ LDH system.

Identification of Emerging Hazards in Mussels by the Galician Emerging Food Safety Risks Network (RISEGAL). A First Approach

Emerging risk identification is a priority for the European Food Safety Authority (EFSA). The goal of the Galician Emerging Food Safety Risks Network (RISEGAL) is the identification of emerging risks in foods produced and commercialized in Galicia (northwest Spain) in order to propose prevention plans and mitigation strategies. In this work, RISEGAL applied a systematic approach for the identification of emerging food safety risks potentially affecting bivalve shellfish. First, a comprehensive review of scientific databases was carried out to identify hazards most quoted as emerging in bivalves in the period 2016-2018. Then, identified hazards were semiquantitatively assessed by a panel of food safety experts, who scored them accordingly with the five evaluation criteria proposed by EFSA: novelty, soundness, imminence, scale, and severity. Scores determined that perfluorinated compounds, antimicrobial resistance, Vibrio parahaemolyticus, hepatitis E virus (HEV), and antimicrobial residues are the emerging hazards that are considered most imminent and severe and that could cause safety problems of the highest scale in the bivalve value chain by the majority of the experts consulted (75%). Finally, in a preliminary way, an exploratory study carried out in the Galician Rías highlighted the presence of HEV in mussels cultivated in class B production areas.

Super-porous semi-interpenetrating polymeric composite prepared in straw for micro solid phase extraction of antibiotics from honey, urine and wastewater

A cryogel-based semi-interpenetrating polymer network (Cryo-SIPN) was prepared in which conductive polymers such as polyaniline (PANI) and polypyrrole (PPy) were formed within the super porous network of acrylic acid cryogel. For completion of cryo-polymerization, all the constituent solutions were severely mixed and placed into the plastic straws and kept at -20°C and then the synthesized cyrogels were cut into the 1-cm length and freeze dried after washing with water. The Cryo-SIPN polymeric composite was applied in micro solid phase extraction (µSPE) of some selected antibiotic residues from various samples. The µSPE method combined with a high performance liquid chromatography-ultraviolet (HPLC-UV) system allowed trace quantification of antibiotic residues in the honey and water samples while the significant variables were optimized using a central composite design (CCD) to find optimum conditions. The method performance was satisfactory with recovery ranges from 70.0 to 109%. The limits of detection (S/N = 3) and quantification (S/N = 10) for all samples were within the 17-50 μg kg^-1 and 47-140 μg kg^-1 range, respectively. The relative standard deviation was less than 10 % for antibiotics in the foodstuff and water samples. The validated Cryo-SIPN-µSPE in conjunction with HPLC-UV, proved to be versatile, efficient and robust while its capability toward the trace determination of drugs residues in real-life samples is demonstrated in this work.

A sensitive and stable visible-light-driven photoelectrochemical aptasensor for determination of oxytetracycline in tomato samples

Sensitive detection of oxytetracycline (OTC) has attracted increasing attention worldwide due to the relationship between food safety and human health problems. In this work, a visible-light-driven photoelectrochemical (PEC) OTC aptasensor was constructed using Bi₄VO₈Cl/nitrogen-doped graphene quantum dots (Bi₄VO₈Cl/N-GQDs) nanohybrids as photoactive material and OTC aptamer as identification element. Owing to the well matched heterojunction of Bi₄VO₈Cl and nitrogen-doped graphene quantum dots (N-GQDs), the photogenerated electron-hole pairs could be separated effectively, so that the photocurrent intensity of as-prepared Bi₄VO₈Cl/N-GQDs nanohybrids was about 7 times higher than pure Bi₄VO₈Cl and had higher stability. The constructed "signal-off" PEC aptasensor realized OTC detection in tomato samples with excellent sensitivity, specificity and repeatability. The photocurrent decreased with the increase of OTC concentration in a range from 0.1 nM to 150 nM, and the detection limit was 0.03 nM (S/N = 3). The national standard method was used to compare with our method and the results were consistent.

Development of a new SLE-SPE-HPLC-MS/MS method for the determination of selected antibiotics and their transformation products in anthropogenically altered solid environmental matrices

The presence of antibiotic residues, their bioactive metabolites and other transformation products in the environment may adversely affect the organisms that live in the environment and may also contribute to increasing the antibiotic resistance of bacteria. It is particularly difficult to determine the types of contaminants in solid samples, in particular, those that are anthropogenically changed, e.g., as a result of controlled biochemical processes. Therefore, the aim of this research was to develop of a new method for the determination of twelve antibiotics belonging to different groups, such as penicillins, sulfonamides, tetracyclines, quinolones, imidazoles and cefalosporins, in digested manure and activated sludge samples, which were used as examples of anthropogenically altered environmental solid samples. The analyses were performed using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The solid-liquid extraction (SLE) method to isolate analytes from digested manure and activated sludge was developed and optimized, the same as clean-up procedure followed by solid phase extraction (SPE). The recovery ranged from 45 to 85%. Finally, the validated method was applied to the determination of the selected antibiotics in manure and activated sludge samples after an anaerobic digestion process.. An additional aim of the study was to verify whether the developed method allows simultaneous detection of transformation products of the studied antibiotics in solid samples. The study showed that by optimizing the analysis conditions, it is possible to simultaneously determine the selected antibiotics and their transformation products (including their epimeric forms), which can significantly improve the ability to control the efficiency of the biological processes used in this area. In practice, this means that the developed methodology may be particularly useful in the context of research and other works related to the anaerobic digestion of activated sludge, manure or other solid substrates of environmental origin.

Application of Nanostructured Carbon-Based Electrochemical (Bio)Sensors for Screening of Emerging Pharmaceutical Pollutants in Waters and Aquatic Species: A Review

Pharmaceuticals, as a contaminant of emergent concern, are being released uncontrollably into the environment potentially causing hazardous effects to aquatic ecosystems and consequently to human health. In the absence of well-established monitoring programs, one can only imagine the full extent of this problem and so there is an urgent need for the development of extremely sensitive, portable, and low-cost devices to perform analysis. Carbon-based nanomaterials are the most used nanostructures in (bio)sensors construction attributed to their facile and well-characterized production methods, commercial availability, reduced cost, high chemical stability, and low toxicity. However, most importantly, their relatively good conductivity enabling appropriate electron transfer rates-as well as their high surface area yielding attachment and extraordinary loading capacity for biomolecules-have been relevant and desirable features, justifying the key role that they have been playing, and will continue to play, in electrochemical (bio)sensor development. The present review outlines the contribution of carbon nanomaterials (carbon nanotubes, graphene, fullerene, carbon nanofibers, carbon black, carbon nanopowder, biochar nanoparticles, and graphite oxide), used alone or combined with other (nano)materials, to the field of environmental (bio)sensing, and more specifically, to pharmaceutical pollutants analysis in waters and aquatic species. The main trends of this field of research are also addressed.

Occurrence of perchlorate, chlorate and polar herbicides in different baby food commodities

The incidence of endocrine disruptors, both possible (glyphosate and glufosinate), and demonstrated (perchlorate and chlorate), was estimated in baby food commodities (meat, fish, cheese, vegetable and fruit). Ion-chromatography coupled to high resolution mass spectrometry analysis of the 105 samples did not show traces of glyphosate, glufosinate or their metabolites, while in 10.5% of the samples a quantifiable amount of perchlorate was found. Some samples based on fruit and vegetables revealed a substantial amount of chlorate, especially the preparations that contained carrots and potatoes: five samples were in a concentration range of 40-120 μg kg^-1, while one homogenized pear sample reached 372.2 μg kg^-1. The pure meat samples revealed occasional chlorate appearance, with less than 10 μg kg^-1. This is the first report of chlorate evaluated in various types of baby food and may serve as symptomatic data regarding its occurrence in infant/toddler diets. Therefore, effective monitoring programs and subsequent strict regulations are strongly required.

Evaluating exposures of bay mussels (Mytilus trossulus) to contaminants of emerging concern through environmental sampling and hydrodynamic modeling

Bay mussels (Mytilus trossulus) were transplanted to 18 locations representing a range of potential exposures throughout Puget Sound, WA. Tissues were analyzed for over 200 organic contaminants. Results indicated the widespread exposure of marine organisms to trace levels of organic contaminants including the synthetic opioid oxycodone, present at three urban sites, and the chemotherapy drug melphalan, present at nine locations, at levels that may be of biological concern. Land-use and wastewater outfalls were evaluated as potential sources of CECs to the nearshore. Exposure to alkylphenol ethoxylates was associated with increased impervious surfaces in upland watersheds. A hydrodynamic simulation was performed using the Salish Sea Model to integrate inputs from 99 wastewater sources to Puget Sound. Predictions were consistent with concentrations of several wastewater-associated contaminants and δ¹⁵N enrichment. These results support the notion that Puget Sound nearshore biota suffer chronic exposures to a suite of contaminants from multiple sources and provide critical to focus future monitoring and management.

Mytilidae as model organisms in the marine ecotoxicology of pharmaceuticals - A review

Growing production and consumption of pharmaceuticals is a global problem. Due to insufficient data on the concentration and distribution of pharmaceuticals in the marine environment, there are no appropriate legal regulations concerning their emission. In order to understand all aspects of the fate of pharmaceuticals in the marine environment and their effect on marine biota, it is necessary to find the most appropriate model organism for this purpose. This paper presents an overview of the ecotoxicological studies of pharmaceuticals, regarding the assessment of Mytilidae as suitable organisms for biomonitoring programs and toxicity tests. The use of mussels in the monitoring of pharmaceuticals allows the observation of changes in the concentration and distribution of these compounds. This in turn gives valuable information on the amount of pharmaceutical pollutants released into the environment in different areas. In this context, information necessary for the assessment of risks related to pharmaceuticals in the marine environment are provided based on what effective management procedures can be developed. However, the accumulation capacity of individual Mytilidae species, the bioavailability of pharmaceuticals and their biological effects should be further scrutinized.

Presence of emerging contaminants in baby food

Food safety becomes imperative when it aims to protect infants. The objective of this study was to investigate the presence of emerging contaminants of which some act as endocrine-disruptors in baby food. Persistent organic pollutants (POPs), perfluoroalkyl substances (PFASs), parabens and antibiotics were analysed in 112 baby food of different categories (meat, fish, vegetables, fruit, cheese). As regard POPs, PFASs and antibiotics, no residues were detected, while one sample showed methyl-paraben (4.14 ng g^-1), whereas another three contained propyl-paraben (median 1.70 ng g^-1). Special attention must be paid on parabens metabolites, as 4-hydroxybenzoic acid, the principal parabens metabolite, was detected in all samples (median 176.7 ng g^-1). It may be present as a degradation product, but also, it can be released from vegetables and fruits during food processing. It is recommended to collect more data on natural vs non-natural occurrence of parabens and metabolites to evaluate the exposure of sensitive population vs ADI published by the European Food Safety Authority and European Medicines Agency.

Geographical origin of bivalve molluscs in coastal areas using natural radioactivity fingerprinting and multivariate statistical analyses: Andalusian coast as case of study

The presence of natural and artificial radionuclides in the marine environment produces the accumulation of radionuclides in bivalve molluscs consumed by humans, and therefore it could result in a radiological hazard. In this study, the activity concentrations of ²¹⁰Po, ⁴⁰K, ²¹⁰Pb and ²³⁴Th were determined in different types of bivalve molluscs sampled during the period of May 2014-June 2015, along coastal areas from the Andalusian region (South of Spain), through alpha-particle spectrometry and low-level gamma-ray spectrometry. The activity concentrations of ²¹⁰Po; ⁴⁰K; ²¹⁰Pb and ²³⁴Th varied between 40 ± 2 and 515 ± 9 Bq kg^-1 dry weight (d.w.); 121 ± 7 and 674 ± 34 Bq kg^-1 d.w.; ND (lower than limit of detection) and 73 ± 10 Bq kg^-1 d.w.; and ND and 126 ± 27 Bq kg^-1 d.w., respectively. The committed effective dose to humans was calculated to range from 41 to 479 μSv year^-1. Both activity concentrations and dose levels were comparable to previous studies from other countries. Finally, a multivariate statistical analysis of natural radioactivity content allowed the discrimination between bivalve molluscs from Atlantic and Mediterranean coasts.

Implementation and Validation of an Analytical Method for Lincomycin Determination in Feathers and Edible Tissues of Broiler Chickens by Liquid Chromatography Tandem Mass Spectrometry

Recent studies have detected different antimicrobial residues in broiler chicken feathers, where they persisted for longer periods of time and at greater concentrations than in edible tissues. However, until today, lincomycin behaviour in this nonedible tissue has not been assessed yet. Considering this, an analytical methodology to detect and quantify this antibiotic concentration in feathers, muscle, and liver tissues from broiler chickens was implemented and in-house validated. The methodology will allow the determination of the bioaccumulation of this highly persistent antibiotic in feathers of treated birds. For this purpose, 98% lincomycin and 95% lincomycin D3 standards were used. Methanol was selected as the extraction solvent, and Chromabond® Florisil® cartridges were used for the clean-up stage. The separation of analytes was performed through the analytical column SunFire C18 with a running time of 4 minutes, and the instrumental analysis was performed through an LC-MS/MS, with a liquid chromatograph Agilent® 1290 Infinity, coupled to an AB SCIEX® API 5500 mass spectrometer. An internal protocol for an in-house validation was designed based on recommendations from Commission Decision 2002/657/EC and the Guidance document on the estimation of limit of detection and limit of quantification for measurements in the field of contaminants in feed and food. The average retention time for lincomycin was 2.255 min (for quantifier ion, 126.0). The calibration curves showed a coefficient of determination (r ²) greater than 0.99 for all matrices, while recovery levels ranged between 98% and 101%. The limit of detection (LOD) calculated was of 19, 22, and 10 μg·kg^-1, and the limit of quantification (LOQ) was of 62, 73, and 34 μg·kg^-1 in feathers, muscle, and liver, respectively. This method detects lincomycin in the studied matrices, confidently and accurately, as it is required for designing analytical studies of drug residues in edible and nonedible tissues, such as feathers.

Human health risk assessment of antibiotic resistance associated with antibiotic residues in the environment: A review

The extensive use of antibiotics leading to the rapid spread of antibiotic resistance poses high health risks to humans, but to date there is still lack of a quantitative model to properly assess the risks. Concerns over the health risk of antibiotic residues in the environment are mainly (1) the potential hazard of ingested antibiotic residues in the environment altering the human microbiome and promoting emergence and selection for bacteria resistance inhabiting the human body, and (2) the potential hazard of creating a selection pressure on environmental microbiome and leading to reservoirs of antibiotic resistance in the environment. We provide a holistic view of health risk assessment of antibiotic resistance associated with antibiotic residues in the environment in contrast with that of the antibiotic resistant bacteria and discuss the main knowledge gaps and the future research that should be prioritized to achieve the quantitative risk assessment. We examined and summarized the available data and information on the four core elements of antibiotic resistance associated with antibiotic residues in the environment: hazard identification, exposure assessment, dose-response assessment, and risk characterization. The data required to characterize the risks of antibiotic residues in the environment is severely limited. The main future research needs have been identified to enable better assessments of antibiotic resistance associated with antibiotic residues in the environment: (1) establishment of a standardized monitoring guide of antibiotic residues and antibiotic resistance in the environment, (2) derivation of the relationship between antibiotic levels and pathogenic antibiotic-resistance development in different settings, and (3) establishment of the dose-response relationship between pathogenic antibiotic resistant bacteria and various infection diseases. After identification of key risk determinant parameters, we propose a conceptual framework of human health risk assessments of antibiotic residues in the environment. CAPSULE: A holistic view of human health risk assessment of antibiotic residues in the environment was provided.

Using mussel as a global bioindicator of coastal microplastic pollution

The ubiquity and high bioavailability of microplastics have an unknown risk on the marine environment. Biomonitoring should be used to investigate biotic impacts of microplastic exposure. While many studies have used mussels as indicators for marine microplastic pollution, a robust and clear justification for their selection as indicator species is still lacking. Here, we review published literature from field investigations and laboratory experiments on microplastics in mussels and critically discuss the suitability and challenges of mussels as bioindicator for microplastic pollution. Mussels are suitable bioindicator for microplastic pollution because of their wide distribution, vital ecological niches, susceptibility to microplastic uptake and close connection with marine predators and human health. Field investigations highlight a wide occurrence of microplastics in mussels from all over the world, yet their abundance varies enormously. Problematically, these studies are not comparable due to the lack of a standardized approach, as well as temporal and spatial variability. Interestingly, microplastic abundance in field-collected mussels is closely related to human activity, and there is evidence for a positive and quantitative correlation between microplastics in mussels and surrounding waters. Laboratory studies collectively demonstrate that mussels may be good model organisms in revealing microplastic uptake, accumulation and toxicity. Consequently, we propose the use of mussels as target species to monitor microplastics and call for a uniform, efficient and economical approach that is suitable for a future large-scale monitoring program.

Distribution of POPs, pesticides and antibiotic residues in organic honeys from different production areas

Demand for honey is increasing, especially if it is organic and if its nutritional properties are linked to untreated environments in order to guarantee quality for health. Sources of contamination of honey can be divided into environmental and apicultural. Therefore, the distribution of persistent organic pollutants, pesticides and antibiotic residues from geographical areas with different contamination sources (high anthropic impact, intensive farming, husbandry and low anthropic impact) was investigated in order to confirm the potential transfer of xenobiotics into the supply chain and to give beekeepers tools for the selection of areas dedicated to organic production. The presence of polychlorinated biphenyls, polybrominated diphenyl ether and polycyclic aromatic hydrocarbons was confirmed, not only in proximity to highly urbanised centres, where the concentrations were higher, but in all environment contexts, confirming their ubiquity. No antibiotics or neonicotinoids were detected in 95 organic honeys, demonstrating the absence of apicultural treatments and consequently the good quality of honey of different areas. These results are important due to the undefined regulatory European situation on honey antibiotic limits.