Concentrations levels and effects of 17alpha-Ethinylestradiol in freshwater and marine waters and bivalves: a review

Pharmaceutical drugs are contaminants of emerging concern and are amongst the most frequent in the aquatic environment. Even though a vast literature indicate that pharmaceuticals exert negative impacts towards aquatic organisms, mainly in vertebrates, there is still limited information regarding the effects of these drugs in freshwater and marine bivalves. Marine bivalves have a high ecological and socio-economic value and are considered good bioindicator species in ecotoxicology and risk assessment programs. Furthermore, another lacking point on these studies is the absence of bioconcentration data, with no clear relationship between the concentration of drugs on tissue and the biological effects. 17alpha-ethinylestradiol (EE2) is a synthetic hormone with high estrogenic potency that was added to the Watch List adopted by the European Commission stating the priority substances to be monitored. Thus, this review summarizes the current knowledge on the concentration levels and effects of EE2 on freshwater and marine bivalves. The inclusion in the Watch List, the presence in freshwater and marine systems, and the impact exerted on aquatic biota, even at trace concentrations, justify the review devoted to this pharmaceutical drug. Globally the available studies found that EE2 induces individual and sub-individual (e.g. tissue, cellular, biochemical and molecular levels of biological organization) impacts in bivalves. Essentially, this estrogenic compound, even in trace concentrations, was found to have accumulated in wild and laboratory exposed bivalves. The most common effects reported were changes on the reproductive function and energy metabolism. The studies used in this review support keeping the EE2 on the Watch List and highlight the need to increase the number of monitorization studies since clear negative effects were exerted on bivalves by this drug.publishe

Can ocean warming alter sub-lethal effects of antiepileptic and antihistaminic pharmaceuticals in marine bivalves?

The negative effects induced in marine organisms by Climate Change related abiotic factors consequences, namely ocean warming, are well-known. However, few works studied the combined impacts of ocean warming and contaminants, as pharmaceutical drugs. Carbamazepine (CBZ) and cetirizine (CTZ) occur in the marine environment, showing negative effects in marine organisms. This study aimed to evaluate the impacts of ocean warming on the effects of CBZ and CTZ, when acting individually and combined (drug vs drug), in the edible clam Ruditapes philippinarum. For that, drugs concentration, bioconcentration factors and biochemical parameters, related with clam's metabolic capacity and oxidative stress, were evaluated after 28 days exposure to environmentally relevant scenarios of these stressors. The results showed limited impacts of the drugs (single and combined) at control and warming condition. Indeed, it appeared that warming improved the oxidative status of contaminated clams (higher reduced to oxidized glutathione ratio, lower lipid peroxidation and protein carbonylation levels), especially when both drugs were combined. This may result from clam's defence mechanisms activation and reduced metabolic capacity that, respectively, increased elimination and limited production of reactive oxygen species. At low stress levels, defence mechanisms were not activated which resulted into oxidative stress. The present findings highlighted that under higher stress levels clams may be able to activate defence strategies that were sufficient to avoid cellular damages and loss of redox homeostasis. Nevertheless, low concentrations were tested in the present study and the observed responses may greatly change under increased pollution levels or temperatures. Further research on this topic is needed since marine heat waves are increasing in frequency and intensity and pollution levels of some pharmaceuticals are also increasing in coastal systems.publishe

Effects of temperature on caffeine and carbon nanotubes co-exposure in Ruditapes philippinarum

In the marine environment, organisms are exposed to a high and increasing number of different con- taminants that can interact among them. In addition, abiotic factors can change the dynamics between contaminants and organisms, thus increasing or even decreasing the toxic effect of a particular com- pound. In this study, the effects of caffeine (CAF) and functionalized multi-walled carbon nanotubes (f- MWCNTs) induced in the clam Ruditapes philippinarum were evaluated, acting alone and in combination (MIX), under two temperature levels (18 and 21 C). To assess the impact of such compounds, their interaction and the possible influence of temperature, biochemical and histopathological markers were investigated. The effects of f-MWCNTs and caffeine appear to be clearly negative at the control tem- perature, with lower protein content in contaminated clams and a significant decrease in their meta- bolism when both pollutants were acting in combination. Also, at control temperature, clams exposed to pollutants showed increased antioxidant capacity, especially when caffeine was acting alone, although cellular damages were still observed at CAF and f-MWCNTs treatments. Increased biotransformation capacity at 18 C and MIX treatment may explain lower caffeine concentration observed. At increased temperature differences among treatments were not so evident as at 18 C, with a similar biological pattern among contaminated and control clams. Higher caffeine accumulation at MIX treatment under warming conditions may result from clams’ inefficient biotransformation capacity when exposed to increased temperatures

Characterization of a new twortlikevirus infecting Staphylococcus epidermidis that exhibits activity against biofilm and stationary bacterial populations

Staphylococcus epidermidis is a major causative agent of nosocomial infections, mainly associated with the use of indwelling devices, on which this bacterium forms structures known as biofilms. Due to biofilms high tolerance to antibiotics, virulent bacteriophages were previously tested as novel therapeutic agents. However, several staphylococcal bacteriophages were shown to be inefficient against biofilms. Using wastewater treatment plant raw effluents, a novel phage was isolated and characterized. This virus was named phiIBB-SEP1 and TEM micrographs suggested that it belonged to the Twortlikevirus genus. Phage phiIBB-SEP1 is able to infect 41 S. epidermidis clinical isolates used in this study, and contrarily to other polyvalent viruses of the Twortlikevirus genus, phiIBB-SEP1 is highly specific for S. epidermidis strains. The genome of this phage was fully sequenced and presents the typical structure of a member of the Twortlikevirus. However, when compared to other staphylococcal members of this genus, it showed DNA sequence identities no greater than 58.2%, suggesting that phiIBB-SEP1 is a new species within this subfamily. Efficacy studies results showed that phage SEP1 is able to cause a 6 Log CFU per ml reduction of the cell titer in less than 2h for some of the clinical strains in exponential phase; and, in less than 4h for stationary phase cells (using a multiplicity of infection of 1). This phage has also the capacity of reducing, by up to 2 Log CFU per ml, 24h scraped biofilm cells. Besides CFU counting, this cell reduction was confirmed by flow cytometry counting. Additionally, live/dead flow cytometry staining allowed the observation that this phage kills biofilms bacteria in different physiological states including dormant cells. These are promising results, since the rare feature presented by this phage of infecting cells with reduced metabolic activity allied with its high broad host strain range suggest its use for therapy purposes

Chronic toxicity of the antiepileptic carbamazepine on the clam ruditapes philippinarum

The impacts of carbamazepine (CBZ) on aquatic organisms are yet notwell investigated. The present study aimed to better understand the chronic effects of environmentally relevant concentrations of CBZ. The experiment was performedby exposing the filter feeding clamRuditapes philippinarum to 0.00, 0.03, 0.30, 3.00 and 9.00 μg/L, during 28 days. To assess the chronic toxicity of the drug a battery of biomarkers related with health status and oxidative stress was applied. In order to quantify CBZ in the clam's tissues and in water samples ELISA was used. The present study showed three types of responses on the clams after a chronic exposure to CBZ. For control condition and the lower concentrations (0.03 and 0.30 μg/L) a “similar” metabolic state was observed and the most efficient antioxidant status leading to the elimination of reactive oxygen species formed during themetabolismof CBZ. The concentration of 3.00 μg/L seemed to be a “threshold” concentration, beyond which the concentration levels of CBZ began to exert a toxic effect, compromising the activity of biotransformation and antioxidant enzymes, with notorious effects at the highest CBZ concentration (9.00 μg/L). CBZ also seemed to alter the energy-related responses, especially the glycogen and electron system responses, revealing a slowdown in metabolism at the higher exposure concentrations (3.00 and 9.00 μg/L). Overall, the present study demonstrated that the higher CBZ concentrations can lead to the impairment of antioxidant enzymes compromising the neutralization of reactive oxygen species, and thus the ability to cope with oxidative stress

Extratos etanólicos de manga como antioxidantes na alimentação de poedeiras

O objetivo deste trabalho foi avaliar o efeito de extratos etanólicos do caroço e da casca de manga, sobre o desempenho de poedeiras e sobre a qualidade e estabilidade lipídica dos ovos. Um total de 180 poedeiras comerciais Hisex White foi distribuído ao acaso em seis tratamentos, com cinco repetições de seis aves. Os tratamentos consistiram de: ração sem adição de antioxidante; ração com 200 ppm do antioxidante butilato de hidroxitolueno (BHT); ração com 200 ou 400 ppm de extrato da casca de manga (Ecas); ração com 200 ou 400 ppm de extrato de caroço de manga (Ecar). Foram avaliados: o consumo de ração, a produção de ovos, o peso do ovo, a massa de ovo produzida (grama por ave por dia), a conversão alimentar e características de qualidade dos ovos. A oxidação lipídica da gema durante o armazenamento foi determinada pela quantificação das substâncias reativas ao ácido tiobarbitúrico. As aves alimentadas com a ração sem adição de antioxidantes produziram ovos com os piores valores de unidade Haugh e maior oxidação lipídica da gema. Os teores de 400 ppm de Ecas e 200 ou 400 ppm de Ecar foram efetivos na prevenção de danos oxidativos aos ovos durante o armazenamento e podem ser utilizados na alimentação das poedeiras como substituto ao antioxidante sintético