Article

Ecotoxicity of veterinary enrofloxacin and ciprofloxacin antibiotics on anuran amphibian larvae

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Abstract

The ecological risks posed by two β-diketone antibiotics (DKAs, enrofloxacin, ENR and ciprofloxacin, CPX), characterized by their long persistence in aqueous environments and known deleterious effect on model organisms such as zebrafish were analysed using Rhinella arenarum larvae. Sublethal tests were conducted using environmentally relevant concentrations of both ENR and CPX (1-1000 μg L⁻¹) under standard laboratory conditions for 96 h. Biological endpoints and biomarkers evaluated were body size, shape, development and growth rates, and antioxidant enzymes (Glutathione-S-transferase, GST; Catalase, CAT). Risk assessment was analysed based on ration quotients (RQ). The size and shape measurements of the larvae exposed to concentrations greater than 10 μg L⁻¹ of CPX were lower compared to controls (Dunnett post-hoc p < 0.05) and presented signs of emaciation. Concentrations of 1000 μg L⁻¹of CPX induced GST activity, in contrast with inhibited GST and CAT of larvae exposed to ENR. Risk assessments indicated that concentrations greater than or equal to10 μg L⁻¹ of CPX and ENR are ecotoxic for development, growth, detoxifying, and oxidative stress enzymes. It is suggested that additional risk assessments may provide evidence of bioaccumulation of CPX and ENR in tissues or organs of amphibian larvae by mesocosm sediment test conditions. Finally, intestinal microbiome studies should be considered to establish the mechanisms of action of both antibiotics.

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... [3] Pharmaceuticals are one of the most persistent groups of pollutants in the environment which could ultimately pose a serious health risk to humans and aquatic biota. Bioaccumulation studies have shown the presence of these compounds in various tissues of fish including muscles [4] , gills [5] , blood plasma [6] , brain [5] and liver. [7] Prolonged exposure of these compounds promotes antibiotic resistance which could hugely affect public health. ...
... [3] Pharmaceuticals are one of the most persistent groups of pollutants in the environment which could ultimately pose a serious health risk to humans and aquatic biota. Bioaccumulation studies have shown the presence of these compounds in various tissues of fish including muscles [4] , gills [5] , blood plasma [6] , brain [5] and liver. [7] Prolonged exposure of these compounds promotes antibiotic resistance which could hugely affect public health. ...
... This inhibition can decrease the efficiency of the waste water treatment plan and may result in contamination of receiving water bodies. [3,5] Toxicity studies of fish, daphnia and algae have been used to predict environmental concentrations and ecological risk of most pharmaceuticals. [7] The biological activity of pharmaceuticals released in aquatic systems has been observed in nature and laboratory investigations have shown that they cause both acute and chronic effects. ...
... The acute toxicity tests were performed in triplicate using 200-mL sterile glass flasks (0.85 cm in diameter, 1100 mm in height), and 10 eggs per flask. Two cohorts of T. typhonius and P. albonotatus were randomly mixed separately for genetic homogenization of each species before placing them into the experimental flasks ( Peltzer et al., 2017). The experiments started by exposing them to DCF at an early developmental stage (Gosner Stage (GS) 5;Gosner, 1960). ...
... Larval mortality showed no differences between replicates during the study period (Fisher's exact test P N 0.05); thus, data (N = 150 for each species) from replicates were pooled in each DFC treatment and control for subsequent analyses (Peltzer et al., 2013a). This chronic exposure finished when at least two larvae reached the GS 38 to avoid morphological changes due to metamorphosis near the climax and reduce floating ( Peltzer et al., 2017), being different between the two species (T. typhonius = 22 days; P. albonotatus = 20 days). ...
... To date, several studies have shown that amphibians under conditions of stress (i.e., pesticides, predators, water acidity) can trigger an excess of ROS, inducing antioxidant activation (Attademo et al. 2007;Menon and Rozman 2007;Lascano et al. 2009;Jones et al. 2010;Burraco and Gomez-Mestre 2016;Curi et al. 2017;Peltzer et al. 2017). However, to our knowledge only one study has evaluated whether amphibian embryos at risk of oomycetes infection trigger antioxidant activation (Ghirardi et al. 2018). ...
... Several studies have shown that under stress conditions (i.e., pesticides, predators, water acidity), amphibians can trigger an excess of ROS, inducing antioxidant activation (Attademo et al. 2007;Menon and Rozman 2007;Jones et al. 2010;Burraco and Gomez-Mestre 2016;Curi et al. 2017;Peltzer et al. 2017). Nevertheless, this amphibian antioxidant system reaction against water mould infections remains little studied or understood (Ghirardi et al. 2018). ...
Article
Water moulds are pathogens of amphibian eggs and embryos. However, little is known about oxidant or antioxidant status of amphibians in response to stress caused by water moulds. We exposed embryo stages of two-coloured oval frogs Elachistocleis bicolor (Guérin-Méneville, 1838) to Saprolegnia -like sp. water mould in order to explore homeostatic adjustments by the shifting of oxidative stress markers. We also tested whether water mould infection affected survivorship and hatching time and morphology of hatching embryos. We found that Saprolegnia -like sp. is a genuine stressor and substantially altered the physiological state of E. bicolor embryos. Among antioxidant defences, superoxide dismutase (SOD) and glutathione S-transferase (GST) activity increased in embryos exposed to Saprolegnia -like sp. However, no difference in lipid peroxidation levels was found between treatments, which might indicate that SOD and GST activation could be enough to prevent oxidative damage. Finally, we found higher mortality and number of malformations in the water mould treatment. We showed the stressful effect of water moulds on amphibian embryos, evidenced by the activation of their antioxidant system, and reveal the importance of considering physiological stress markers as key information when studying the potential consequences of disease outbreaks in the ecology and conservation of amphibians.
... The direct discharge of untreated wastewater to the environment is another main source, particularly in developing countries [5]. Several pharmaceuticals released into the aquatic environment have been linked to imposing a large variety of toxic effects in both vertebrates and invertebrates [8][9][10][11]. ...
... Hydrogen peroxide (mg L -1 ) two processes (i.e., Peroxi-EC and Peroxi-PEC) are lower than the PEC process. This might be due to the addition of H 2 O 2 in these processes, that let the reaction depicted in Eq. (8), and eventually lower the pH in comparison to the PEC process. In the Peroxi-PEC process in the presence of urea, the final pH is higher than Peroxi-PEC process in the absence of urea. ...
... For different model organisms, toxic values obtained from 48-h acute testing of CFX, OFX, and TET revealed substantial variability (Dalla Bona et al., 2014;Havelkova et al., 2016;Isidori et al., 2005;Li, 2013). Acute tests using biomarkers done on multiple model organisms using CFX, OFX, and TET, on the other hand, are highly sensitive, regardless of the organisms studied (Dionísio et al., 2020;Nogueira and Nunes, 2020;Peltzer et al., 2017;Xie et al., 2019;Yang et al., 2019). Biomarkers are not utilized to evaluate dangerous levels because negative effects on biomarkers do not always represent the phenotypes of tested animals, such as behavior (Nogueira and Nunes, 2020), morphology (Peltzer et al., 2017), and life-history features (Nunes et al., 2018). ...
... Acute tests using biomarkers done on multiple model organisms using CFX, OFX, and TET, on the other hand, are highly sensitive, regardless of the organisms studied (Dionísio et al., 2020;Nogueira and Nunes, 2020;Peltzer et al., 2017;Xie et al., 2019;Yang et al., 2019). Biomarkers are not utilized to evaluate dangerous levels because negative effects on biomarkers do not always represent the phenotypes of tested animals, such as behavior (Nogueira and Nunes, 2020), morphology (Peltzer et al., 2017), and life-history features (Nunes et al., 2018). Only two research have looked into the ecotoxicity of GFX so far. ...
Article
Antibiotics, widely known as major environmental xenobiotics, are increasingly being released into ecosystems due to their essential functions in human health and production. During the COVID-19 pandemic waves, antibiotic use increases remarkably in treating bacterial coinfections. Antibiotics were initially expected only to affect prokaryotes, but recent research has shown that they can disturb the biological systems of eukaryotes, especially vulnerable aquatic creatures, through both direct and indirect processes. However, their toxicity to the freshwater cladoceran Simocephalus vetulus, an essential link in the aquatic food web, has never been evaluated. The effects of four fluoroquinolones (ciprofloxacin: CFX, ofloxacin: OFX, gatifloxacin: GFX, delafloxacin: DFX), tetracycline (TET), and a mixture of these medicines (MIX) on S. vetulus thoracic limb rate (TLR) were examined in this study. After S. vetulus was exposed to 20 and 40 mg GFX L⁻¹, 90% and 100% mortality rates were recorded. At 2.5–10 mg L⁻¹, GFX dramatically lowered the TLR of S. vetulus, resulting in a median effective concentration of 9.69 mg L⁻¹. TLRs increased when the organisms were exposed to 10–40 mg L⁻¹ of CFX and 1.25–40 mg L⁻¹ of OFX. However, DFX and TET exposures did not affect TLRs. Exposure to MIX reduced TLR only at 40 mg L⁻¹, suggesting an antagonistic interaction among the five pharmaceuticals. This study demonstrated that S. vetulus physiological responses to antibiotics, even in the same class, are complex and elusive. Beyond a common additive concentration principle, the antagonistic interaction of antibiotic mixture indicates a high level of uncertainty in terms of ecological dangers. We initially introduce S. vetulus to ecotoxicological studies of antibiotics, presenting the species as a low-cost model for physiological investigations of environmental xenobiotics.
... The continued entry of enrofloxacin into the aquatic environment poses a long-term threat to the organisms living there. The removal of enrofloxacin and other fluoroquinolone antibiotics is a very complex process, and it is not always effective [155,156]. Therefore, the biocontrol of organisms exposed to these antibiotics is crucial. The effects of en-rofloxacin on the growth of giant freshwater shrimp were investigated. ...
... Moreover, the induction of oxidative stress by enrofloxacin is believed to be a likely cause of this phenomenon [157]. Interestingly, a safety analysis of this antibiotic on anuran amphibian larvae showed that the environmental concentration of enrofloxacin (10 µg/L) affected the development, size, shape, and growth of larvae, as well as inhibiting the activity of antioxidant enzymes [155]. It was also proposed that in Daphnia magna, enrofloxacin can cause high reproductive toxicity, as well as genetic or epigenetic changes that will only produce effects in subsequent generations [158][159][160]. ...
Article
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Enrofloxacin is a compound that originates from a group of fluoroquinolones that is widely used in veterinary medicine as an antibacterial agent (this antibiotic is not approved for use as a drug in humans). It reveals strong antibiotic activity against both Gram-positive and Gram-negative bacteria, mainly due to the inhibition of bacterial gyrase and topoisomerase IV enzymatic actions. The high efficacy of this molecule has been demonstrated in the treatment of various animals on farms and other locations. However, the use of enrofloxacin causes severe adverse effects, including skeletal, reproductive, immune, and digestive disorders. In this review article, we present in detail and discuss the advantageous and disadvantageous properties of enrofloxacin, showing the benefits and risks of the use of this compound in veterinary medicine. Animal health and the environmental effects of this stable antibiotic (with half-life as long as 3–9 years in various natural environments) are analyzed, as are the interesting properties of this molecule that are expressed when present in complexes with metals. Recommendations for further research on enrofloxacin are also proposed.
... The direct discharge of untreated wastewater to the environment is another main source, particularly in developing countries [5]. Several pharmaceuticals released into the aquatic environment have been linked to imposing a large variety of toxic effects in both vertebrates and invertebrates [8][9][10][11]. ...
... Hydrogen peroxide (mg L -1 ) two processes (i.e., Peroxi-EC and Peroxi-PEC) are lower than the PEC process. This might be due to the addition of H 2 O 2 in these processes, that let the reaction depicted in Eq. (8), and eventually lower the pH in comparison to the PEC process. In the Peroxi-PEC process in the presence of urea, the final pH is higher than Peroxi-PEC process in the absence of urea. ...
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This study evaluates the performance of photoelectrocoagulation, peroxi-electrocoagulation, and peroxi-photoelectrocoagulation for the removal of the antiviral drug lamivudine formulation from wastewater by a stainless-steel electrode. To investigate matrix effects for this oxidation process, the influence of substrates such as urea and simulated wastewater (SWW) was studied. Moreover, degradation kinetics and energy efficiency are also discussed. Results indicate that the removal efficiency was in the order of peroxi-photoelectrocoagulation > peroxi-photoelectrocoagulation (in the presence of urea) > peroxi-photoelectrocoagulation (in the presence of SWW) > peroxi-electrocoagulation > photoelectrocoagulation. In peroxi-photoelectrocoagulation, the 96% degradation of lamivudine formulation indicates a nearly complete degradation of lamivudine. In this process, the presence of urea and SWW resulted in a substantial reduction of chemical oxygen demand (COD) decay. Kinetic studies using linear pseudo-first and pseudo-second-order reaction kinetics showed that the pseudo-first-order equation effectively described the removal of lamivudine formulation. The highest energy consumption per kgCOD decay (i.e., kWh kgCOD− 1) was obtained for the photoelectrocoagulation process, while the lowest energy consumption was obtained for peroxi-electrocoagulation, for all electrolysis times. The peroxi-photoelectrocoagulation process was shown to be an effective and energy-efficient technique for removing the antiviral drug lamivudine formulation from wastewater. Graphic abstract
... After exposure to SMM, CFT, TC, ENR, and their mixture at 100 μg/L, the body lengths of zebrafish larvae were significantly inhibited, and some larvae were deformed. Previous studies have reported the malformation of Danio rerio larvae after treatment with sulfadiazine (0.01 and 10 mg/L) and the mixture of six β-diketone antibiotics (N37.5 mg/L) (Lin et al., 2014;Peltzer et al., 2017;Wang et al., 2014). It was also found that 20 μg/L TC could induce malformation and reduce the body lengths of Danio rerio larvae (Zhang et al., 2015b). ...
... While 200 μg/L norfloxacin and sulfamethoxazole showed no adverse effect on the body lengths of Danio rerio larvae, it did negatively affect the body weight (Yan et al., 2016); this may be because of the different sensitivities of individual organisms to various antibiotics. In addition, the body lengths of another aquatic organism, Rhinella arenarum, were also inhibited by treatment with 100 μg/L ciprofloxacin (Peltzer et al., 2017). Therefore, from the results of the above-mentioned studies, it can be shown that antibiotics have a negative effect on the early development of bony fishes. ...
Article
In China, antibiotics are commonly used for human and veterinary medicine, and they are present in various environmental media. Thus, the toxic effects of antibiotics on organisms have attracted the attention of society and scientists alike. In this study, zebrafish embryos were used to test the single and joint toxicity of four antibiotics, sulfamonomethoxine (SMM), cefotaxime sodium (CFT), tetracycline (TC), enrofloxacin (ENR), and their combinations, combining the results of experimental and omics techniques. Following exposure to antibiotics for 120 h, the body lengths of zebrafish larvae in all 100 μg/L antibiotic groups were significantly shortened, and the reactive oxygen species (ROS) content in the 100 μg/L Mix group was significantly increased. Transcriptome sequencing (RNA-seq) showed that the mRNA level of numerous genes was significantly changed in the five antibiotic treatment groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differentially expressed genes revealed a significant enrichment of the steroid biosynthesis and other metabolism pathways. Hub gene analysis highlighted dhcr24, acat1, aldh1a2, aldh8a1, suclg2, hadh, and hsdl2 as the key genes, and hub gene expression changes because of the antibiotic treatment suggested that the metabolic system of the zebrafish larvae was severely disrupted by the interaction with other genes. In conclusion, single or joint exposure to different antibiotics at environmental concentrations affected the early development and metabolic system of zebrafish larvae, and our results provide fundamental evidence for future studies of antibiotic toxicity in aquatic organisms.
... Most anuran species have a tadpole form that is always bound to an aquatic or very moist habitat (Duellman and Trueb, 1986). Morphological features of tadpoles have been analyzed by applying traditional and geometric morphometric techniques to study their shape evolution in different habitats (e.g., Van Buskirk, 2009Baldo et al., 2014;Marques and Nomura, 2015;Sherratt et al., 2018), relationships between morphology and locomotory performance (e.g., burst speed) (e.g., Van Buskirk and Relyea, 1998;Dayton et al., 2005;Arendt, 2010;Johansson, Lederer and Lind, 2010), and the effects of predation (e.g., Ferland-Raymond and Murray, 2008;Johnson et al., 2015), antibiotics and herbicides (e.g., Katzenberger et al., 2014;Peltzer et al., 2017) on tadpole shape. Moreover, as research on tadpoles is expanding, and the tadpoles of some species are visually quite alike, the need for proper taxonomic identification is becoming more urgent (McDiarmid and Altig, 1999). ...
... For taxonomic identification, we applied the DNA barcoding method with the 16S rRNA sequence as the gene marker (Ilić et al., 2016). In accordance with previously published papers dealing with morphological variation in tadpoles, we chose a standard set of 2D landmarks (Dayton et al., 2005;Ferland-Raymond and Murray, 2008;Arendt, 2010;Johansson, Lederer and Lind, 2010;Haad, Vera Candioti and Baldo, 2011;Katzenberger et al., 2014;Johnson et al., 2015;Peltzer et al., 2017) and linear measurements (Relyea, 2001;Grosjean, 2005;Alvarez and Nicieza, 2006;Altig, 2007;Arendt, 2010;Hsu et al., 2011;Lima and Pederassi, 2012;Ilić et al., 2016). In order to compare the methodologies for quantification and description of morphological differences among the three species of tadpoles, we aimed to 1) calculate interspecies genetic distances as the most relevant measurement of species differentiation, 2) determine and describe size and shape variation, 3) identify relationships among the analyzed species at the morphological level and 4) assess their classification accuracy. ...
Article
We conducted a comparative (2D landmark-based geometric and traditional) morphometric analysis on tadpoles at early developmental stages. Two species of brown frog ( Rana dalmatina and R. temporaria ) and the common toad ( Bufo bufo ) were involved, all raised in the laboratory from fertilized eggs collected in their natural habitat. Taxonomic identification was confirmed by the DNA barcoding method with the 16S rRNA sequence as the gene marker. Interested to compare the methodologies for quantification and description of morphological differences among tadpoles of mentioned species, we aimed to: 1) calculate interspecies genetic distances as the most relevant measurement for species differentiation, 2) determine and describe size and shape variation, 3) identify relationships among the analyzed species at the morphological level and 4) assess their classification accuracy. Within the framework of the specified aims, both methodologies produced very similar results, i.e., the smallest divergence was between R. dalmatina and R. temporaria , while the most discriminative were B. bufo and R. temporaria . However, we observed subtle shape variation of the distal region of the tail that was detected only by the geometric morphometrics. Our findings support the following. Geometric morphometric method captures more subtle shape differences that were unable to be recovered from linear measurements. It performs slightly better in classification rate. Although it was not quantified, it stands to reason that there is no difference in time investment between the two approaches. Geometric morphometrics provides more information that can be leveraged to answer further questions and it has a clear advantage in visualizing.
... In another study investigating the effects on Amphibia (Rhinella arenarum) exposed to 1, 10, 100 and 1000 lg/L for 4 days, ciprofloxacin reduced the larval length at 10 lg/L. A significant development inhibition greater than 10% was observed for the concentrations of 100 and 1000 lg/L, and additionally, GST levels were increased at 1000 lg/L (Peltzer et al., 2017). For meiofauna, marine nematodes have especially shown that the beta-lactam antibiotic, penicillin G, significantly decreases the univariate index including species number, Shannon index, Margalef's richness and Pielou's equitability after experimental treatment during 30 days (Nasri et al., 2015). ...
Article
Full-text available
A laboratory bioassay was performed to assess the ecotoxicity of ciprofloxacin on a meiobenthic nematodes community from Bizerte lagoon (NE Tunisia). Four ciprofloxacin doses [D1 (50 µg/g), D2 (100 µg/g), D3 (200 µg/g), and D4 (500 µg/g)] were applied to the substrate, and responses were studied after one month. Discernible differences were observed between control assemblages and those populating ciprofloxacin treated substrates. All univariate indices were affected significantly compared to those in the control microcosm with increasing antibiotic concentration. The non-parametric Multi-Dimensional Scaling based on species abundances (MDS) showed significant separation of the control microcosm from the antibiotic-treated populations. The nematode species responses to the fluoroquinolone treatments varied: Odontophora villoti was reduced at all concentrations of ciprofloxacin and was considered “sensitive,” whereas Metoncholaimus pristiurus was affected by moderate concentrations; its abundance increased with the highest dose D4 and was described as “opportunistic.” Paramonohystera pilosa, whose abundance increased with antibiotic doses appeared “resistant.” Keywords: Meiobenthic nematodes, Susbstrate, Antibiotic, Ciprofloxacin, Exposure, Bioassay
... The potential risk of some antiinflamamatory drugs to the reproductive success of estuarine crabs are currently under evaluation by the author of this editorial. Several antiobiotics of common use in cattle and poultry veterinary medicine have shown to affect both growth and development in amphibian larvae, at environmental concentrations [6]. Similarly to the situation mentioned above for the consumption of drugs by human population, there is no regulation in Argentina for processing the wastes produced by feedlots; therefore, the environmental impact of drugs for veterinary use is expected to remain high. ...
... The presence of enrofloxacin in this kind of natural water course constitutes a huge environmental problem related to the generation of harmful effects on native flora and fauna, and on the population as well. In this regard, Peltzer et al. (2017) have demonstrated the negative effects that enrofloxacin and ciprofloxacin have on the development of the South American common toad Rhinella arenarum (Anura: Bufonidae). In their in vitro study of biological endpoints (mainly development, growth, and antioxidant enzyme activities), impairments were observed after exposure to enrofloxacin and ciproflaxin; the authors concluded that continuous exposure to these substances can lead wileyonlinelibrary.com/ETC ...
Article
Full-text available
The use of fluoroquinolones for the treatment of infections in humans and animals has increased in Argentina, concurrently with the possibility of finding them in large amount in water bodies. In the present work, the occurrence and associated ecological risk of five fluoroquinolones were investigated in rivers and farm wastewaters of San Luis, Santa Fe, Córdoba, Entre Ríos and Buenos Aires provinces of Argentina by high‐performance liquid chromatography coupled to fast‐scanning fluorescence detection and ultra‐high performance liquid chromatography coupled to triple quadrupole mass spectrometry detection. The maximum concentrations of ciprofloxacin, enrofloxacin, ofloxacin, enoxacin and difloxacin found in wastewater were 1.14, 11.9, 1.78, 22.1 and 14.2 μg L–1, respectively. In the case of river samples, only enrofloxacin was found at a concentration of 0.97 μg L–1. The individual risk of aquatic organisms associated with water pollution due to fluoroquinolones was higher in bacteria, cyanobacteria, algae, plant and anuran than in crustaceae and fish with, in some cases, risk quotients higher than 1. The proportion of samples classified as high risk was 87.5% for ofloxacin, 63.5% for enrofloxacin, 57.1% for ciprofloxacin and 25% for enoxacin. These studies suggested that the prevalence of fluoroquinolones in the water could be potentially risky for the aquatic ecosystem, and harmful to biodiversity. This article is protected by copyright. All rights reserved.
... Además del uso humano, los antibióticos son usados ampliamente en veterinaria para controlar enfermedades causadas por infecciones bacterianas y como estimuladores de crecimiento. Un ejemplo del amplio uso de antibióticos se presentó en China, uno de los países con más producción y consumo de estos de alimentos y productos de origen animal 10,11 . Los compuestos farmacéuticos son relativamente recalcitrantes e inclusive algunos se muestran resistentes a la biodegradación. ...
Article
Full-text available
Los antibióticos son fármacos considerados como contaminantes emergentes, usados para el tratamiento de enfermedades bacterianas, los antibióticos son utilizados en salud humana y veterinaria. Los antibióticos al ser metabolizados incompletamente llegan a las aguas residuales a través de las heces fecales y orina, añadiendo la contaminación causada por su mala disposición final, efluentes hospitalarios y algunas industrias, llegando a las plantas de tratamiento de aguas residuales, en donde no son tratados adecuadamente por la falta de monitoreo y su normatividad, además de que se encuentran en concentraciones trazas y ultratrazas lo que dificulta su monitoreo. Los antibióticos en el ambiente pueden generar genes de resistencia bacteriana, disminuir diversidad microbiana, y ser tóxicos para algunas especies de peces e invertebrados. En América Latina existen muy pocos estudios sobre el monitoreo de los fármacos, sin embargo en algunos estudios se ha visto que las concentraciones ambientales llegan a ser mayor en algunos cuerpos de agua que en aguas residuales. Esta revisión plantea visibilizar la problemática ambiental de los antibióticos en América Latina, desde la falta de monitoreo hasta la nula regulación ambiental que existe en estos países.
... According to data obtained in this study and previous reports, the increase in antibiotic concentrations that accumulated in blood clam might be attributed to both the Trojan horse effect and the disruption of detoxification. 18,53 On the basis of accumulating evidence, waterborne pollutants, including antibiotics such as OTC and FLO, may be absorbed on the surface of MPs. 54,55 Because MPs are easily ingested by clams through filter-feeding, 25,56 MPs may therefore carry condensed antibiotics into the body of the clam and subsequently increase the in vivo concentrations of OTC and FLO. ...
Article
Edible bivalves are one of the major types of seafood and may be subject to antibiotic and microplastics (MPs) co-exposure under realistic scenarios. However, the effect of MPs on the bioaccumulation of antibiotics in edible bivalves and subsequent health risks for consumers remain poorly understood. Therefore, the bioaccumulation of two frequently detected veterinary antibiotics, oxytetracycline (OTC) and florfenicol (FLO), with or without the co-presence of MPs was investigated in the blood clam. Health risks associated with the consumption of contaminated clams were also assessed. Furthermore, the activity of GST and expression of key detoxification genes were analyzed as well. The bioaccumulation of OTC and FLO in clams was found to be aggravated by MPs. Since the estimated target hazard quotients (THQs) were far less than the critical value, direct toxic effects of consuming contaminated clams are negligible. However, the dietary exposure doses of the human gut microbiota (DEGM) to the antibiotics tested were greater than or similar to corresponding minimum selective concentrations (MSC), indicating a potential antibiotic resistance risk. Moreover, the GST activity and expression of detoxification genes were significantly suppressed by MPs, suggesting that the disruption of detoxification represents one possible explanation for the aggravated bioaccumulation observed here.
... Pharmaceuticals are among the prime examples of contaminants that have recently been detected in water systems, with up to 90% of oral drugs that pass through the human body ending up in the water supply. 1 These emerging pollutants, therefore, present a new global water quality challenge with potentially serious implications to human health and ecosystems. Some of the challenges include the development of antibiotic-resistant bacteria and genes 2 , persistence of endocrine disrupting compounds in aquatic systems, and other deleterious ecotoxicological effects 3,4 . The increased consumption, disposal and presence of human pharmaceuticals in the environment, particularly in aquatic systems, has raised concerns worldwide due to their continued introduction into the environment mainly via hospital effluents, agricultural activities and waste-water treatment plants (WWTP). ...
Article
Full-text available
The carbon footprint of pharmaceuticals through manufacturing, distribution, the incineration of unwanted pharmaceuticals as well as the packaging of pharmaceutical waste is an emerging and enormous challenge. Pharmaceuticals are major contributors to water pollution in aquatic environments that include surface water and groundwater. These pollutants arise not only from waste products but also from pharmaceutical products that have not been properly disposed of. The continuous exposure to unspecified sub-therapeutic doses of antibiotics presents risks to humans and other animals. Due to their extensive use and incomplete elimination, antibiotics have been detected in various environmental waters. The persistence of antibiotics in the environment and chronic exposure of organisms to these chemical stressors has also proven to have ecotoxicological effects. The prevailing emergence of antimicrobial resistance amongst bacteria is an area of primary concern, especially with regard to the release of antibiotics into the environment. Resistance is the acquired ability of bacterial populations to render an antibiotic ineffective as a result of a change in bacterial DNA which occurs when bacteria are subjected to an antibiotic concentration that will not kill them. A sub-lethal concentration possibly exerts a selective pressure that can result in the development of antimicrobial resistance in bacteria. It is clear that there is a need for extensive research to improve regulations and guidance on pharmaceutical waste management, pharmaceutical take-back programmes and consumer awareness.
... Expanding knowledge about the consequences of sub-lethal effects and chronic exposure to antimicrobials and their metabolites in aquatic invertebrates, fish, other aquatic species, and aquatic environment was identified as an important necessity (53,54). Peltzer et al. (55) pointed out the need for additional risk assessments to show bioaccumulation of antibiotics in tissue and organs of amphibian larvae and consequently ecological impairments in water and aquatic system sediments. Several authors pointed out the need for toxicological studies to evaluate and better understand the health risk that these bacteria may present (54,56,57). ...
Article
Antimicrobial resistance (AMR) is a public health concern that has gained increasing global awareness, and it is estimated that there will be 10 million deaths annually by 2050. The importance of the role of the environment in disseminating clinically relevant AMR is a concern. Although research on AMR in Latin America and the Caribbean (LAC) has been conducted, these data have not been analyzed together to better understand which areas in AMR have been more studied, and which require more attention. Objective: Determine the state of knowledge and identify the information gaps for AMR in water in LAC through an exploratory review that identifies the scientific articles that have addressed the topic. Method: The process of selecting scientific articles from databases consisted of the four phases of an exploratory review focusing on eight themes of interest. Results: The selection process identified 289 studies that were published between 1973 and October 2017, and these studies were included in the analysis. Most of the research was performed from 2008 to 2017. Brazil was the main contributor to the study of AMR in the region while no research was identified in AMR in water in eight of 18 of LAC countries. The most researched topics in water are phenotypic detection of AMR (theme VIII), detection of antimicrobial resistance genes (ARG) (theme V), and degradation of AMR (theme III). Limited research was identified on insects, agricultural products, aquatic organisms, livestock, and wastewater other than hospital wastewater. Research on emerging pests and diseases with a potential impact on the production of AMR (theme VII), impact of the use of antimicrobials on agricultural production (theme IV), and negative effects of AMR on wildlife (theme II) was scarce.
... Expanding knowledge about the consequences of sub-lethal effects and chronic exposure to antimicrobials and their metabolites in aquatic invertebrates, fish, other aquatic species, and aquatic environment was identified as an important necessity (53,54). Peltzer et al. (55) pointed out the need for additional risk assessments to show bioaccumulation of antibiotics in tissue and organs of amphibian larvae and consequently ecological impairments in water and aquatic system sediments. Several authors pointed out the need for toxicological studies to evaluate and better understand the health risk that these bacteria may present (54,56,57). ...
Article
Introduction: Antimicrobial resistance (AMR) is a public health concern that has gained increasing global awareness, and it is estimated that there will be 10 million deaths annually by 2050. The importance of the role of the environment in disseminating clinically relevant AMR is a concern. Although research on AMR in Latin America and the Caribbean (LAC) has been conducted, these data have not been analyzed together to better understand which areas in AMR have been more studied, and which require more attention. Objective: Determine the state of knowledge and identify the information gaps for AMR in water in LAC through an exploratory review that identifies the scientific articles that have addressed the topic. Method: The process of selecting scientific articles from databases consisted of the four phases of an exploratory review focusing on eight themes of interest. Results: The selection process identified 289 studies that were published between 1973 and October 2017, and these studies were included in the analysis. Most of the research was performed from 2008 to 2017. Brazil was the main contributor to the study of AMR in the region while no research was identified in AMR in water in eight of 18 of LAC countries. The most researched topics in water are phenotypic detection of AMR (theme VIII), detection of antimicrobial resistance genes (ARG) (theme V), and degradation of AMR (theme III). Limited research was identified on insects, agricultural products, aquatic organisms, livestock, and wastewater other than hospital wastewater. Research on emerging pests and diseases with a potential impact on the production of AMR (theme VII), impact of the use of antimicrobials on agricultural production (theme IV), and negative effects of AMR on wildlife (theme II) was scarce. Conclusions: We suggest to focus research efforts and resources to study themes I, II, IV, VI, and VII, for which there is little research in LAC, without hindering the valuable research conducted on themes III, V, and VIII. The AMR environmental situation is mainly driven by a few countries that are not representative of the LAC region, and therefore, research is needed in other LAC countries besides Brazil.
... Several studies have indicated that AChE is also sensitive to complex mixtures of pollutants including antibiotics and pesticides (Guilhermino et al., 2000;Tu et al., 2009 , to binary mixtures with GBH and quaternary complex mixture treatments led to a significant decrease in AChE activity. In other ecotoxicological researches in R. arenarum tadpoles, we found that exposure to CP 125 μg/L led to an inhibition of 42-78% of AChE activities (Attademo et al. 2017). Barreto et al. (2020) reported similar findings for Boana pulchella tadpoles acutely exposed to environmentally relevant concentrations of CP, wit ha significant decrease in AChE in tadpoles exposed to 0.1 mg/LCP (21 %) and 0.5 mg/L CP (21 %). ...
Article
The presence of pesticides as well as that of several antibiotics provided at a great scale to poultry, cattle, and swine in aquatic environments within agroecosystems is a matter of growing concern. The objective of the present study was to characterize the sublethal effects of four environmental toxic compounds at two experimental pollution scenarios on the morphology, development and thyroid (T4), acetylcholinesterase (AChE) and glutathione S-transferase (GST) levels in Rhinella arenarum tadpoles. The first experimental pollution scenario aimed to evaluate the individual and mixed toxicity (50:50% v/v) of a glyphosate-based herbicide (GBH) and the antibiotic ciprofloxacin (CIP) on earlier developmental stages. The second experimental pollution scenario aimed to evaluate the effects of other toxic compounds (the insecticide chlorpyrifos (CP) and the antibiotic amoxicillin (AMX)) added to the ones from the first scenario on previously exposed premetamorphic tadpoles. In all the treatments of the first pollution scenario, the most conspicuous effect observed in early-stage tadpoles was a high prevalence of morphological abnormalities. Exposure to GBH and to its mixture with CIP also led to a significant decrease in T4 levels and lower development. Both pollutant combinations from the second experimental scenario significantly increased T4 levels, inhibited AChE activities, and led to lower development, whereas the quaternary mixture led to a significant decrease in GST levels. The alterations here revealed by our approaches in several morphological and biochemical endpoints allow characterizing the ecotoxicological risk for anurans exposed to complex mixtures of pollutants that frequently occur in aquatic systems.
... They are impacted by anthropogenic action, serve as reservoirs for resistance factors (Marti et al., 2014), and reports of adverse effects on aquatic organisms are plenty. Algae (Lanzky and Halting-Sørensen, 1997), ciliates (Láng and Kőhidai, 2012), amphibians (Peltzer et al., 2017), and fish (Carlson et al., 2015;Liu et al., 2012;Yin et al., 2014) are some examples where the overall health, survival, reproductive status, and/or biochemical markers have been altered by these drugs, demonstrating their influence in the entire food chain of aquatic organisms. However, in this context, the effects of antibiotic exposure on the behavior of aquatic animals were rarely explored (Liu et al., 2017;Pan et al., 2017;Wang et al., 2016). ...
Article
Antibiotics are widely used drugs in human and veterinary health as well as in the food industry. The majority of these compounds are, however, excreted unchanged and found as contaminants in water bodies. Although the toxicity of these drugs was previously studied in aquatic organisms, the behavioral effects of these pollutants have not been fully explored. Here we exposed adult zebrafish to environmentally relevant concentrations of different classes of antibiotics (Chlortetracycline, Ciprofloxacin, and Ceftazidime) and assessed zebrafish exploratory, cognitive, aggressive, and social behaviors. Ciprofloxacin, Chlortetracycline, and Ceftazidime exposure induced hyperlocomotion, which was characterized by an increase in the distance traveled in zebrafish. These antibiotics promoted cognitive decline and exacerbated aggressive behavior. In summary, this study shows that antibiotic contamination may impact zebrafish behavior in a short-time manner.
... Ciprofloxacin is the main metabolite of the veterinary antibiotic enrofloxacin, and it is also a pharmaceutical used in human medicine. Both compounds have been proved to exert a negative impact on amphibian larvae growth and development at concentrations greater than or equal to 10 μgL −1 [25]. Photo-transformation products of the antibiotic tetracycline exhibit a higher toxicity towards luminescent bacteria V. fischeri than tetracycline [26] and photoproducts of the hormone altrenogest seem to possess significant androgenic activity according to in vitro tests performed by Wammer et al. [27]. ...
Thesis
La Directive Cadre sur l’Eau (2000) fait état de la dégradation du bon état chimique des eaux superficielles et des eaux souterraines. Parmi les polluants émergents mis en cause figurent les résidus de médicaments qui représentent une menace diffuse et potentiellement persistante dans les hydro-systèmes. A ce jour, peu d’études se sont intéressées spécifiquement aux résidus médicamenteux vétérinaires (RMV). En France, la Bretagne est une région d'élevage intensif. 75% des eaux destinées à la consommation humaine (EDCH) sont issues d’eau de surface particulièrement vulnérables. Dans ce contexte, les objectifs de cette thèse sont de (i) sélectionner les sites à risque et les RMV d’intérêt, (ii) développer une méthode d’analyse pour la liste de composés retenus, (iii) acquérir des premières données d’occurrence par les RMV dans les EDCH en Bretagne et (iv) identifier les sources des RMV à l’aide de l’étude de la contamination fécale associée dans les eaux brutes. Cette thèse est constituée de trois chapitres : une synthèse bibliographique des connaissances relatives aux RMV dans les eaux brutes et les eaux traitées, ainsi qu’une synthèse sur les outils existant pour étudier la contamination fécale ; les matériels et méthodes incluant la stratégie d’échantillonnage, le choix des RMV d’intérêt et les méthodes d’analyse développées sur cette base; les données d’occurrence des RMV dans les EDCH bretonnes. Ces travaux se concluent sur un contexte plus large avec des perspectives pour mieux comprendre les facteurs impactant ces occurrences et pour évaluer l’exposition de la population.
... Tadpoles are very vulnerable because xenobiotics can penetrate the skin, mouth, and gills in the aquatic environment (Pollo et al. 2016). Studies evaluating environmental quality are performed in laboratory, with micronucleus and comet bioassays, among others (Arcaute et al. 2014;Peltzer et al. 2017). ...
Article
Full-text available
Animals have a long history of assessing ecosystem responses to environmental disturbances, and amphibians stand out for presenting themselves as good animal model and bioindicators of environmental quality. The main purpose of the present work was to investigate the cellular effects of contamination of waters of the Marrecas River, located in the southwest of the state of Paraná, Brazil. Therefore, the objective of the present study was to investigate and monitor the cytotoxic and mutagenic effect, with bullfrog tadpoles, and to discuss these effects with land use along this hydrographic basin. Mutagenic effects were determined by micronucleus assay, and cytotoxicity by other nuclear changes, such as segmented cells, binucleated cells, cells with buds and reniform cells. Water samples were obtained at nine sites along the Marrecas River, covering areas with rural and urban hydrological contribution. For each site, four samples were collected, along the years 2017 and 2018, encompassing the four seasons (summer, autumn, winter, and spring). The results showed mutagenic and cytotoxic effect in four sampling sites, and only cytotoxic effect in other four sites. These effects may be due, possibly, to the use of different agrochemicals across the hydrographic basin region, which have predominant hydrological contributions from crops. Data of this study indicate the presence of cytotoxic and mutagenic contaminants in the waters of the Marrecas River, which can generate environmental problems on the river fauna/flora, and can also affect the local population health.
... In 2013, a total of 92,700 tons of 36 most common antibiotics were used in China, the largest producer and consumer of antibiotics, as shown in Fig. 1 (Zhang et al. 2015). The extensive use of antibiotics has led to the spread of antibiotics in the environment throughout the country, which has caused a series of potential hazards, such as the biotoxicity of antibiotics themselves and the emergence of drug-resistant bacteria, which have attracted more attention (Martin 2011;Wollenberger et al. 2000;Robinson et al. 2010;Peltzer et al. 2017;Rahube and Yost 2010). ...
Article
Full-text available
China, the largest producer and user of antibiotics in the world, discharges excessive amounts of these substances into the environment, without prior treatment. This results in ubiquitous distribution of these substances, as well as increased levels of drug-resistant bacteria, that will eventually cause unimaginable consequences to the environment and to humans. However, most of the research on antibiotics has focused on residue analysis of single medium such as wastewater and landfills. There is paucity of research that systematically investigates the fate of antibiotics after excretion, and specifically of end-treatment processes. In this paper, the fate of antibiotic emissions is systematically calculated. The results show that human and livestock feces account for 57.6% and 42.6% of the discharge of medicinal antibiotics and veterinary antibiotics, respectively. Of these feces types, pig feces accounted for 98.7% of antibiotic residues in livestock feces. The above conclusions can be used to clarify the direction of the tracking and supervision of antibiotic residues and provide new ideas for the treatment of antibiotics, especially their terminal removal.
... Although the concentrations of pharmaceutical compounds and their metabolites are low in the environment, their harmfulness and risk to humans and animals are very high (Boxall et al. 2012). Their presence in the environment may create drug resistance amongst pathogens and lead to many negative impacts such as convulsion, This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY-NC-ND 4.0), which permits copying and redistribution for non-commercial purposes with no derivatives, provided the original work is properly cited (http:// creativecommons.org/licenses/by-nc-nd/4.0/) brain damage, cancer diseases, reproductive behavioral disorder, liver damage, cardiovascular diseases and lung defects as well as disturbances in gene expression and other deleterious ecotoxicological effects on aquatic organisms (Saravanan et al. 2014;Peltzer et al. 2017). Pharmaceutical compounds are discharged to the environment and water resources through different sources (Ilyas et al. 2020). ...
Article
Full-text available
Emerging contaminants such as pharmaceutical compounds offer potential hazards to the aquatic environment and human health. In this paper, the adsorptive removal of the drug Nitrazepam from water was investigated for the first time using biochar prepared from Sargassum macroalgae. The removal efficiency of Nitrazepam using 1 g/L of Sargassum macroalgae-derived biochar was 98% with a maximum adsorption capacity of 143.12 mg/g. Effects of solution pH, adsorbent mass, adsorbate concentration, contact time and temperature on the removal of Nitrazepam were investigated. Different adsorption isotherms and kinetics were also tested. It was found that the solution pH slightly influenced the removal efficiency. The adsorption data fit the Freundlich isotherm model and the adsorption process of Nitrazepam onto Sargassum macroalgae-derived biochar is spontaneous, endothermic and followed the pseudo-second-order kinetics. Based on this work, it was determined that the low-cost Sargassum macroalgae-derived biochar adsorbent could be a promising adsorbent to remove Nitrazepam from water effectively. Highlights A biochar prepared from macroalgae was investigated for Nitrazepam removal from water.; The adsorbent has high efficiency and adsorption capacity for Nitrazepam emerging contaminant.; The kinetics and thermodynamics of Nitrazepam adsorption were studied.; The adsorption process was spontaneous, endothermic and thermodynamically favorable.; Mixed mechanism was dominated by physisorption and followed pseudo second-order kinetics.;
... En las últimas décadas los anfibios han resultado ser modelos sumamente adecuados para el estudio de diferentes problemáticas tanto a 4.6 Estudios experimentales 187 Caja 4.6.1 -Esquema generalizado de los componentes lógicos de un programa de investigación. Adaptado de Underwood (1) escala global como regional, como el estudio de estresores antropogénicos tales como la pérdida de hábitat, la contaminación ( 11,12 , citando solo un par de ejemplos de Argentina), la introducción y/o translocación de especies que pueden resultar invasoras (ejemplo en Argentina: 13 ), las enfermedades emergentes ( 14 ; en Argentina [15][16][17], y el cambio climático global (18)(19)(20)(21)(22)(23) . También los anfibios han constituido un modelo de estudio en enfoques de biología evolutiva del desarrollo ("Evo-Devo") (24) con abundantes estudios en Argentina como, variación y diversificación morfológica (e.g. ...
... Additionally, exposure to pesticides has been associated with altered cholinesterase and glutathione S-transferase activities as well as erythrocyte nuclear abnormalities in amphibians (Slaby et al., 2019;Venturino et al., 2003). Exposure to the antimicrobial drugs enrofloxacin and ciprofloxacin at concentrations >10 μg L -1 induces altered larval development, increased oxidative stress and reduced growth rates in Rana arenarum (Peltzer et al., 2017). ...
Article
Full-text available
Anthropogenic pressure such as agricultural pollution globally affects amphibian populations. In this study, a total of 178 different compounds from five agrochemical groups (i.e. antimicrobial drugs residues (ADRs), coccidiostats and anthelmintics, heavy metals, mycotoxins and pesticides) were determined monthly, from March until June 2019 in 26 amphibian breeding ponds in Flanders, Belgium. Furthermore, a possible correlation between the number and concentration of selected contaminants that were found and the percentage of arable land within a 200 m radius was studied. Within each group, the highest detected concentrations were obtained for 4-epioxytetracycline (0.422 μg L⁻¹), levamisole (0.550 μg L⁻¹), zinc (333.1 μg L⁻¹), 3-acetyldeoxynivalenol (0.013 μg L⁻¹), and terbuthylazine (38.7 μg L⁻¹), respectively, with detection frequencies ranging from 1 (i.e. 3-acetyldeoxynivalenol) to 26 (i.e. zinc) out of 26 ponds. Based on reported acute and chronic ecotoxicological endpoints, detected concentrations of bifenthrin, cadmium, copper, cypermethrin, hexachlorobenzene, mercury, terbuthylazine, and zinc pose a substantial ecological risk to aquatic invertebrates such as Daphnia magna and Ceriodaphnia dubia, which both play a role in the food web and potentially in amphibian disease dynamics. Additionally, the detected concentrations of copper were high enough to exert chronic toxicity in the gray treefrog (Hyla versicolor). The number of detected compounds per pond ranged between 0 and 5 (ADRs), 0 - 2 (coccidiostats and anthelmintics), 1 - 7 (heavy metals), 0 - 4 (mycotoxins), and 0 - 12 (pesticides) across the four months. Furthermore, no significant correlation was demonstrated between the number of detected compounds per pond, as well as the detected concentrations of 4-epioxytetracycline, levamisole, copper, zinc, enniatin B and terbuthylazine, and the percentage of arable land within a 200 m radius. For heavy metals and pesticides, the number of compounds per pond varied significantly between months. Conclusively, amphibian breeding ponds in Flanders were frequently contaminated with agrochemicals, yielding concentrations up to the high μg per liter level, regardless of the percentage surrounding arable land, however showing temporal variation for heavy metals and pesticides. This research also identifies potential hazardous substances which may be added to the European watch list (CD 2018/408/EC) in the future.
... En las últimas décadas los anfibios han resultado ser modelos sumamente adecuados para el estudio de diferentes problemáticas tanto a 4.6 Estudios experimentales 187 Caja 4.6.1 -Esquema generalizado de los componentes lógicos de un programa de investigación. Adaptado de Underwood (1) escala global como regional, como el estudio de estresores antropogénicos tales como la pérdida de hábitat, la contaminación ( 11,12 , citando solo un par de ejemplos de Argentina), la introducción y/o translocación de especies que pueden resultar invasoras (ejemplo en Argentina: 13 ), las enfermedades emergentes ( 14 ; en Argentina [15][16][17], y el cambio climático global (18)(19)(20)(21)(22)(23) . También los anfibios han constituido un modelo de estudio en enfoques de biología evolutiva del desarrollo ("Evo-Devo") (24) con abundantes estudios en Argentina como, variación y diversificación morfológica (e.g. ...
Chapter
Full-text available
El objetivo principal de este Manual es el desarrollo de un compendio de técnicas y protocolos estándares para el inventario y monitoreo de poblaciones de anfibios, actualizado con los procedimientos, herramientas y técnicas de análisis más recientes y adaptado a las condiciones y realidades nacionales. Su contenido está destinado a ayudar a superar algunas de las dificultades que se pueden enfrentar al configurar un programa de inventario y monitoreo para anfibios. Pretendemos brindar una orientación práctica sobre cómo diseñar y llevar a cabo estudios que puedan servir para múltiples aplicaciones más allá de las necesidades de un proyecto particular. En este manual compilamos las experiencias y consejos de numerosos especialistas sobre diferentes temáticas que pudieran permitir a los lectores y usuarios de este manual obtener la mayor cantidad y calidad de datos durante la realización de futuros proyectos de investigación relacionados con estas temáticas.
... En las últimas décadas los anfibios han resultado ser modelos sumamente adecuados para el estudio de diferentes problemáticas tanto a 4.6 Estudios experimentales 187 Caja 4.6.1 -Esquema generalizado de los componentes lógicos de un programa de investigación. Adaptado de Underwood (1) escala global como regional, como el estudio de estresores antropogénicos tales como la pérdida de hábitat, la contaminación ( 11,12 , citando solo un par de ejemplos de Argentina), la introducción y/o translocación de especies que pueden resultar invasoras (ejemplo en Argentina: 13 ), las enfermedades emergentes ( 14 ; en Argentina [15][16][17], y el cambio climático global (18)(19)(20)(21)(22)(23) . También los anfibios han constituido un modelo de estudio en enfoques de biología evolutiva del desarrollo ("Evo-Devo") (24) con abundantes estudios en Argentina como, variación y diversificación morfológica (e.g. ...
Article
The presence of antibiotics in wastewater, domestic water, and sewage has been found to produce ecotoxicological effects on living beings. Fluoroquinolones (FQs) are recognized as critically important and highly prioritized antimicrobial and are frequently used in veterinary and human medicine. The recalcitrance of these antibiotics along with their poor metabolism has led to their detection in manures and wastewater. Ciprofloxacin (CIP) is a synthetic and commonly prescribed FQ and the metabolite of enrofloxacin, the veterinary drug. CIP has negative effects on the flora and fauna. Due to the emergence of bacterial resistance against FQs, special attention is given to the environmental degradation of these antibiotics by microorganisms. Physicochemical processes and bioremediation are employed for the removal of CIP, but the lipophilic and hydrophobic nature of the antibiotics acts as a hindrance to their complete removal from the environment. The present review gives an insight into the sources of FQs in the environment, their detection, and their impact on living beings. CIP removal is being paid special attention and recent trends in its removal are discussed.
Article
Atrazine, a widely used herbicide, is a potential threat to the intestines of animals due to its long-term persistence in water and accumulation in animal tissues, but the underlying mechanism is unclear. In this study, we evaluated the toxicity of atrazine (50, 100, and 500 µg/L) on the intestine of Pelophylax nigromaculatus larvae from Gosner stages 18–42 (about 90 days). We conducted a 16 S rRNA gene amplification study, which showed that chronic exposure to atrazine changed the diversity and composition of intestinal microbiota of P. nigromaculatus larvae. Chronic exposure to atrazine (50, 100, and 500 µg/L) significantly decreased the relative abundance of Fusobacteria and U114, while 50 µg/L and 100 µg/L atrazine resulted in a significant increase of Clavibacter. The LC-MS/MS metabolomics indicated that there were 145 significantly changed metabolites. Furthermore, atrazine led to metabolic abnormalities related to purine metabolism and biosynthesis of amino acids in the intestine. The transcriptomic results showed that atrazine exposure caused 21,120 differentially expressed genes between the control and the atrazine exposure groups. Atrazine exposure primarily disturbed the pathways related to the cytokine-cytokine receptor interaction and cell adhesion molecules. Moreover, 500 µg/L atrazine caused a significant up-regulation in the gene expression of apolipoprotein (ApoA1, ApoB, and ApoA4), and fatty acid binding protein (FABP1), as well as a significant down-regulation in the gene expression of superoxide dismutase (SOD). Our work provides insight into the ecotoxicity mechanisms of atrazine in amphibians at the level of intestinal microbiota response, metabolome and transcriptome, and serves as a basis for future research on pesticide pollutants.
Article
Background Although animal experiments found that antibiotic exposure during early life increased adiposity, limited human epidemiological evidence is available for the effects of veterinary antibiotic exposure on children's growth and development. Objective This study was conducted to examine the body burden of fluoroquinolones in northern Chinese children and assess its association with growth and development. Methods After recruiting 233 children aged 0–15 years from 12 different sites in northern China in 2020, we measured urinary concentrations of 5 respective fluoroquinolones (fleroxacin, ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin) by high performance liquid chromatography. Categories of children's growth and development were identified based on the Z score of body mass index. The health risks of individual and combined antibiotic exposure were estimated by the hazard quotient (HQ) and hazard index (HI), respectively. The association between children's growth and development with antibiotic concentrations was evaluated via multiple logistic regression analysis. Results In total, 4 antibiotics, fleroxacin, ofloxacin, ciprofloxacin, and enrofloxacin, were found in urine samples of northern Chinese children at an overall frequency of 57.08%. Due to diet and economic differences, antibiotic concentrations in urine samples differed by study area, and the highest concentrations were found in Tianjin, Henan, and Beijing. The percentage of the participants with HQ > 1 caused by ciprofloxacin exposure was 20.61%, and the HI values in 23.18% of samples exceeded 1, suggesting potential health risks. The odds ratio (95% confidence interval) of overweight or obesity risk of tertile 2 of enrofloxacin was 3.01 (1.12, 8.11), indicating an increase in overweight or obesity risk for children with middle-concentration enrofloxacin exposure. Conclusion This is the first study to show a positive association of enrofloxacin internal exposure with overweight or obesity risk in children, demonstrating that more attention should be given to the usage and disposal of fluoroquinolones to safeguard children's health.
Article
The presence of antibiotics in different water sources is a ubiquitous, global concern. The persistence of trace amounts of antibiotics can lead to antibiotic resistance of microbial pathogens and jeopardize the health of ecosystems. One possible solution is the photocatalytic degradation of antibiotics from water systems by titanium dioxide (TiO2) photocatalysis. In recent years, heterogeneous TiO2 has been examined for the photocatalytic degradation of ciprofloxacin (CIP) under UV/visible light irradiation. This review offers an overview of the recent advances in visible light-activated TiO2 for the photocatalytic degradation of CIP and the factors impacting the photocatalytic behavior. In particular, we focused on the structural elucidation of reaction intermediates, and we aimed to determine research gaps in the utilization of visible light-activated TiO2 for water treatment. Future research directions, including the ecotoxicological effect of the photocatalytic degradation intermediates, the thermodynamical and kinetic mechanisms of the photocatalytic degradation process, and future applications of heterogeneous TiO2 photocatalysts, are also proposed.
Article
Fluoroquinolone antibiotics (FQs) that persist and bioaccumulate in the environment have aroused people's great concern. Here, we studied the adverse effects of FQs in soil animals of Caenorhabditis elegans via food-chronically exposure. The result shows C. elegans exposed to FQs exhibited reproductive toxicity with small-brood size and low-egg hatchability. To study the underlying mechanism, we conduct a deep investigation of enrofloxacin (ENR), one of the most frequently detected FQs, on nematodes which is one of commonly used animal indicator of soil sustainability. The concentration-effect curves simulated by the Hill model showed that the half effect concentrations (EC50) of ENR were (494.3 ± 272.9) μmol/kg and (107.4 ± 30.9) μmol/kg for the brood size and the hatchability, respectively. Differential gene expression between the control and the ENR-exposure group enriched with the oxidative stress and cell apoptosis pathways. The results together with the enzyme activity in oxidative stress and the cell corpses suggested that ENR-induced reproductive toxicity was related to germ cell apoptosis under oxidative stress. The risk quotients of some soil and livestock samples were calculated based on the threshold value of EC10 for the egg hatchability (2.65 μmol/kg). The results indicated that there was possible reproductive toxicity on the nematodes in certain agricultural soils for the FQs. This study suggested that chronic exposure to FQs at certain levels in environment would induce reproductive toxicity to the nematodes and might reduce the soil sustainability, alarming the environment risks of antibiotics abuse.
Article
This study aimed to determine the effects of Enrofloxacin (ENR) exposure and depuration on the disruption of thyroid function and growth of juvenile grass carp (Ctenopharyngodon idella) as well as to assess the risk of ENR exposure to human health. Juvenile grass carp were treated with ENR solutions at different concentration gradients for 21 days and then depurated for 14 days. The results indicated ENR accumulation in the juvenile grass carp muscles, which persisted after depuration. In addition, exposure to ENR could alter growth by regulating the expression of genes associated with growth hormone/insulin-like growth factor (GH)/IGF) axis and the hypothalamic–pituitary–thyroid (HPT) axis. During ENR exposure, no significant changes in growth hormone levels were observed; however, a significant increase in the growth hormone level was noted. GH/IGF axis-related genes were upregulated after ENR exposure, and their expression levels remained high after depuration. Notably, a significant increase in the serum triiodothyronine (T3) and thyroxine (T4) levels coincided with the upregulation of HPT axis-related genes in both exposure and depuration treatments, and their expression levels remained high after depuration. Therefore, juvenile grass carp exposure to ENR induces physiological stress through HPT and GH/IGF axes that cannot be recovered after depuration. ENR accumulates in the muscles of juvenile grass carp and may pose a threat to human health. Therefore, exposure of juvenile grass carp to ENR results in impaired thyroid function and impaired growth. In addition, consumption of ENR-exposed fish poses human health risks.
Article
The aim of the present study was to investigate the bioaccumulation and toxicological effects of four antiretrovirals (lamivudine, stavudine, zidovudine and nevirapine) on Rhinella arenarum tadpoles, after short-term (48 h) exposure to these drugs at sublethal concentrations. The analytical procedure involved a simple extraction method followed by ultra-high performance liquid chromatography with diode array detection and chemometric analysis for data processing. Under the conditions studied, the analytes investigated, particularly nevirapine, showed possible bioaccumulation in tadpoles. Besides, an increase in the bioaccumulation was observed when increasing the exposure concentration. In addition, the enzymatic biomarkers measured to evaluate the toxicological effects showed that acethylcholinesterase activity was similar to that of the control group, while glutathione S-transferase activity was increased, indicating potential oxidative stress damage. Our results also allowed demonstrating the usefulness of chemometric algorithms to quantitate analytes in complex matrices, such as those absorbed by tadpoles in aquatic ecosystems. The results also evidenced the short-term antiretroviral bioaccumulation in tadpoles and the alteration of antioxidant systems, highlighting the need of environmental studies to elucidate the ecotoxicological risk of antiretrovirals in humans and wildlife.
Article
Antiretrovirals are pharmaceuticals used in the treatment of the human immunodeficiency virus; they are contaminants of emerging concern that have received considerable attention in recent decades due to their potential negative environmental effects. Data on the bioaccumulation and possible environmental risks posed by these drugs to aquatic organisms are very scarce. Therefore, the aim of this study was to evaluate the bioaccumulation of abacavir and efavirenz in Rhinella arenarum tadpoles subjected to acute static toxicity tests (96 h) at environmentally relevant concentrations. The analytical procedure consisted of the development and optimization of a method involving ultra-high performance liquid chromatography with tandem mass spectrometry detection. The instrumental conditions, optimized by design of experiments using the response surface methodology, yielded limits of detection of 0.3 μg L⁻¹ for abacavir and 0.9 μg L⁻¹ for efavirenz; and limits of quantification of 1.9 μg L⁻¹ for abacavir and 5.6 μg L⁻¹ for efavirenz. Subsequently, the bioaccumulation of the pharmaceutical drugs in tadpoles was evaluated at three exposure concentrations. Efavirenz displayed the highest bioaccumulation levels. This study shows the bioaccumulation potential of abacavir and efavirenz in amphibian tadpoles at exposure concentrations similar to those already detected in the environment, indicating an ecological risk for R. arenarum and probably other aquatic organisms exposed to these drugs in water bodies.
Article
Micropollutants (MPs) released into aquatic ecosystems have adverse effects on public health. Hence, monitoring and managing MPs in aquatic systems is imperative. MPs can be quantified by high-resolution mass spectrometry (HRMS) with stable isotope-labeled (SIL) standards. However, high cost of SIL solutions is a significant issue. This study aims to develop a rapid, cost-effective analytical approach to estimate MP concentrations in aquatic systems based on deep learning (DL) and multi-objective optimization. We hypothesized that internal standards could quantify the MP concentrations other than the target substance. Our approach considered the precision of intra-/inter-day repeatability and natural organic matter information to reduce instrumental error and matrix effect. We selected standard solutions to estimate the concentrations of 18 MPs. Among the optimal DL models, DarkNet-53 using nine standard solutions yielded the highest performance, while ResNet-50 yielded the lowest. Overall, this study demonstrated the capability of DL models for estimating MP concentrations.
Chapter
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Manual de técnicas y protocolos para el relevamiento y estudio de anfibios de Argentina L a u r a P e r e y r a E d u a r d o E t c h e p a r e M a r c o s V a i r a E d i t o r e s 2021
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The purpose of this long-term experiment was on gaining more insights into the environmental behaviour of veterinary antibiotics in the subsurface after application with manure. Therefore, manure spiked with a bromide tracer and eight antibiotics (enrofloxacin, lincomycin, sulfadiazine, sulfamethazine, tetracycline, tiamulin, tilmicosin and tylosin) in concentrations of milligrams per litre were applied at an experimental field site. Their pathway was tracked by continuous extraction of soil pore water at different depths and systematic sampling of groundwater for a period of two years. Seven target compounds were detected in soil pore water of which four leached into groundwater. Concentrations of the detected target compounds were, with few exceptions, in the range of nanograms per litre. It was concluded that a large fraction of the investigated antibiotics sorbed or degraded already within the first meter of the soil. Further, it was inferred from the data that long and warm dry periods cause attenuation of the target compounds through increased degradation or sorption occurring in the soil. In addition, the comprehensive data-set allowed to estimate a retardation factor between 1.1 and 2.0 for sulfamethazine in a Plaggic Anthrosol soil, and to classify the individual compounds by environmental relevance based on transport behaviour and persistence. According to the distribution of resistant genes in the environment, sulfamethazine was found to be the most mobile and persistent substance.
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Manual de técnicas y protocolos para el relevamiento y estudio de anfibios de Argentina L a u r a P e r e y r a E d u a r d o E t c h e p a r e M a r c o s V a i r a E d i t o r e s 2021
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The high load of agrochemicals and antibiotics coexisting in aquatic environments within agroecosystems represents a risk for wildlife. As the gut microbiota plays a key role on its host’s functioning and is sensitive to a wide variety of pollutants, its study allows evaluating organisms’ health and therefore, the ecosystem. We studied toxic effects of commercial formulations of a glyphosate-based herbicide (GBH) and the antibiotic ciprofloxacin (CIP) on gut bacterial microbiota diversity of the common toad ( Rhinella arenarum ) tadpoles, considered a sentinel species. The study was carried out by classic microbiological analysis and matrix-assisted laser desorption ionization-time of flight mass spectrometry. The microbiota from GBH treatment had greater taxa diversity and richness, including some genera, such as Proteus spp. and Yersinia spp. that were absent in control. In contrast, microbiota from CIP treatment registered a decrease of diversity indexes, dominance of Aeromonas spp. and presence of Leclercia spp. The GBH-CIP treatment showed changes in taxa composition, including decrease of Klebsiella spp. and Pseudomonas spp. and trends of individual pollutant treatments. For all cases, changes in the composition of bacterial community (dysbiosis) were linked to a significant decrease in tadpoles’ weight. To the best of our knowledge, this is the first report on the disruption of gut bacterial microbiota of tadpoles by a mixture of two contaminants of emerging concern worldwide. These findings contribute to understanding how the presence of two co-occurring pollutants in freshwaters results in deleterious effects on the amphibian community and potentially affect the microbiota of those environments.
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El objetivo principal de este Manual es el desarrollo de un compendio de técnicas y protocolos estándares para el inventario y monitoreo de poblaciones de anfibios, actualizado con los procedimientos, herramientas y técnicas de análisis más recientes y adaptado a las condiciones y realidades nacionales. Su contenido está destinado a ayudar a superar algunas de las dificultades que se pueden enfrentar al configurar un programa de inventario y monitoreo para anfibios. Pretendemos brindar una orientación práctica sobre cómo diseñar y llevar a cabo estudios que puedan servir para múltiples aplicaciones más allá de las necesidades de un proyecto particular. En este manual compilamos las experiencias y consejos de numerosos especialistas sobre diferentes temáticas que pudieran permitir a los lectores y usuarios de este manual obtener la mayor cantidad y calidad de datos durante la realización de futuros proyectos de investigación relacionados con estas temáticas.
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Dexamethasone (DEX) is a glucocorticoid highly effective as an anti-inflammatory, immunosuppressant and decongestant drug. In the present study, a preliminary acute toxicity test was assayed in order to determinate DEX median-lethal, lowest-observed-effect and the no-observed effect concentrations (LC50, LOEC and NOEC, respectively) on the common toad embryos (Rhinella arenarum). Also, morphological and histological abnormalities from five body larval regions, liver melanomacrophages (MM) and glutathione S-transferase (GST) activity were evaluated in the toad larvae to characterize the chronic sublethal effects of DEX (1–1,000 mg L-1). Results of the acute test showed that the LC50 of DEX at 96 h of exposure for the toad embryos (GS 18–20) was 10.720mg L-1, and the LOEC was 1 mg L-1. In the chronic assay, the larval development and body length were significantly affected. DEX exposition also induced teratogenic effects. Most frequent external abnormalities observed in DEX-treated larvae included abdominal edema and swollen body, abnormal gut coiling and visceral congestion. Intestinal dysplasia was recurrent in cross-section of all DEX-treated larvae. Neural, conjunctive and renal epithelial cells were also affected. Significant increase in liver MM number and size, and GST activity levels were also registered in DEX treatments with respect to controls. The evaluation of a variety of biomarkers provided clear evidence of toad larvae sensitivity to DEX, and the ecotoxicological risk of these pharmaceuticals, commonly found in different water bodies worldwide on aquatic animals.
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The release of pharmaceutical chemicals in the biosphere can have unpredictable ecological consequences, and knowledge concerning their putative toxic effects is still scarce. One example of a widely used pharmaceutical that is present in the aquatic environment is ciprofloxacin. Previous indications suggest that this drug may exert several adverse effects on exposed biota, but the characterization of a full ecotoxicological response to this drug is far from complete, especially in estuarine ecosystems. This work aimed to characterize the acute and chronic effects of ciprofloxacin in the polychaete Hediste diversicolor (Annelida: Polychaeta), exposed to environmentally relevant levels of this drug, close to the real concentrations of this pharmaceutical in surface waters. The adopted toxic endpoints were behavioral parameters, combined with a biomarker-based approach (quantification of the activities of catalase (CAT), glutathione-S-transferase (GSTs), cholinesterases (ChEs), glutathione peroxidase (GPx), and lipid peroxidation levels. Exposure to ciprofloxacin caused effects on behavioural traits, such as an increase in burrowing times and hyperactivity, alongside alterations in biomarkers, including a significant increase in CAT activity following acute exposure. In addition, and after both acute and chronic exposure, lipid peroxidation was reduced, while AChE activities were enhanced. It was possible to ascertain the occurrence of pro-oxidative alterations following exposure to low levels of ciprofloxacin, which were counteracted by the triggering of CAT activity. The meaning of the enhancement of AChE activity is not clear, but it appears to be linked with the observed behavioural changes, and may have been associated with the stimulation of the behavioural traits. These data strongly suggest that the presence of ciprofloxacin in estuarine areas is not without risks, and exposed biota, namely polychaete species, are likely to have their ecological roles affected, thereby compromising the chemical, physical and microbiological stability of sediments, which in turn alters nutrient cycles.
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Ciprofloxacin drugs are a second‐generation fluoroquinolone highly prescribed medication against various bacterial infections in human and aquaculture practices. These drugs are chemically designed to persist in the body long enough to achieve target objectives. Extensive usage has resulted in ciprofloxacin becoming a ubiquitous contaminant in the environment. Unfortunately, the ecotoxicological profiles for ciprofloxacin are scanty. This study was aimed to assess the ecotoxicity of ciprofloxacin at environmentally relevant concentrations (1 μg/L, and 1.5 μg/L) to a cultivable fish Cirrhinus mrigala. Responses of antioxidant enzymes, histological anomalies, and inorganic ion levels were studied. SOD activity in gill, liver, and kidney tissues was elevated in ciprofloxacin‐exposed groups when compared with the control group. CAT activity was predominantly decreased in ciprofloxacin treated groups relative to the control group. GST activity in the ciprofloxacin treated groups was increased (except kidney tissues [Treatment I (1 μg/L)], and gill tissues fifteenth day) significantly (p < .05). The LPO level was elevated in the ciprofloxacin treatment groups throughout the study period (except Treatment II (1.5 μg/L) tenth day in kidney tissues). A series of histological anomalies were noticed in the gill, liver, and kidney tissues of the ciprofloxacin treated groups. Ciprofloxacin exposure caused a significant decrease of sodium, potassium, and chloride levels in the plasma of C. mrigala. A parallel among an imbalanced oxidative defense system, tissue structural changes, and alterations of plasma inorganic ions could be considered as a reliable biomarker for antibiotic toxicity study. This study could be a primary platform for further toxicity studies to understand the potential molecular impacts and adverse effects of ciprofloxacin on aquatic organisms.
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In this study, the effects of enrofloxacin-based antibiotic (EBA) used as a drug in veterinary medicine were evaluated on zebrafish embryos and larvae. The embryos were exposed to 17.56–300 mg L⁻¹ EBA for 96 h and survival rates and body malformations were evaluated under a stereo-microscope. In addition, 10-days larvae were exposed to LC50/4, LC50/2 and LC50 concentrations of antibiotic for 72 h and activities of glutathione S-transferase (GST), glutathione reductase, carboxylesterase, acetylcholinesterase, lactate dehydrogenase (LDH) and aspartate aminotransferases (AST) were measured. LC50 and EC50 values and the teratogenic index (TI) were calculated as 150.1 and 124.8 mg L⁻¹ and 1.2, respectively. EBA was teratogen for zebrafish embryos according to calculated TI. Spinal curvature, tail malformation, pericardial oedema and yolk sac oedema were determined in embryos exposed to 88.8 mg L⁻¹ and higher EBA concentrations. Furthermore, significant growth inhibitions were determined in larvae exposed to 59.26 mg L⁻¹ and above EBA concentrations. Also, 75 and 150 mg L⁻¹ concentrations of EBA caused a significant increase in GST, LDH and AST activities in zebrafish larvae. These results show that EBA causes adverse effects on zebrafish development and may adversely affect the aquatic ecosystem if it enters the aquatic environment.
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In this study the effects of environmentally realistic concentrations of the antibiotics sulfamethoxazole (SMX) and oxytetracyclyne (OTC) on Lithobates catesbeianus tadpoles were evaluated, through the analyzes of the frequencies of micronucleus and nuclear abnormalities in erythrocytes, alterations in leucocytes, liver histopathology, and changes in hepatic esterase activities and oxidative stress biomarkers. The animals were exposed for 16 days at concentrations of 0 (control), 20, 90 and 460 ng L⁻¹. No significant difference was found in the frequencies of micronucleus and nuclear abnormalities. The two highest concentrations of SMX and all concentrations of OTC caused a significant increase in the number of lymphocytes. A significant decrease in the number of neutrophils compared to the control group was observed for all concentrations tested of both antibiotics. Also, decrease in the activity of glutathione S-transferase and high histopathological severity scores, indicating liver damage, were found in tadpoles exposed to the two highest concentrations of SMX and all concentrations of OTC. The main changes in the liver histopathology were the presence of inflammatory infiltrate, melanomacrophages, vascular congestion, blood cells and eosinophils. Esterase activities were unchanged. Indeed, the two highest concentrations of OTC caused a reduction in the activities of superoxide dismutase and glucose 6-phosphate dehydrogenase, while the highest concentration inhibited the activity of glutathione peroxidase and increased protein carbonyl levels. These results evidences that environmentally realistic concentrations of SMX and OTC in aquatic environments are capable to significantly disrupt tadpoles’ physiology, possibly affecting negatively their survival rate in natural environments..
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The aim of the present study was to assess the ecotoxicity of glyphosate and glufosinate ammonium mixtures on amphibian tadpoles and the potential impact of mixture in aquatic ecosystems health. The bonding properties of the mixture based on computational chemistry and an experimental bioassay on morphology, DNA damage and biochemical biomarkers on tadpoles of the common toad Rhinella arenarum were studied. The results of the density functional theory analysis showed trends of the pesticides clustering to form exothermic mixtures, suggesting the likelihood of hot-spots of pesticides in real aquatic systems. In addition, biological effects of individual pesticides and the mixture were studied on tadpoles over 45 days-chronic bioassay. The bioassay consisted of four treatments: a negative control (CO), 2.5 mg L⁻¹ of a glyphosate-based herbicide (GBH), 2.5 mg L⁻¹ of a glufosinate ammonium-based herbicide (GABH) and their 50:50 (% v/v) mixture (GBH-GABH). Morphological abnormality rates were significantly higher in all herbicide treatments with respect to CO at 48 h of exposure. Abdominal edema was the most frequent type of abnormality recorded at 48 h, 10 and 45 days of exposure. DNA damage was recorded in all herbicides treatments. Thyroxin increased only in GABH treatment. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) significantly increased in GBH treatment, indicating a GBH-neurotoxic effect. Glutathione S-transferase decreased in GABH and GBH-GABH treatments, while catalase decreased in individual GBH and GABH treatments. Overall, teratogenicity, DNA damage, hormonal disruption (T4), and oxidative stress were greater in GABH-treated tadpoles than GBH-treated tadpoles. This study also highlights the robust chemical interaction between the active ingredients of both herbicides, which is reflected on antagonisms in most of analyzed biomarkers, as well as potentiation and additivity in others. Based on our results, the GABH had a higher toxicity than GBH for amphibian tadpoles.
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This paper addresses the issue of antibacterial drugs, estrogens and cytostatic drugs' presence in surface waters and their influence on animals. The ecotoxicity and the impact of three active compounds: ciprofloxacin, 17α-ethinylestradiol and 5-fluorouracil on protozoa, crustaceans and fish were examined. Acute tests (crustaceans' immobilization test, fish survival test, enzymatic test on Daphnia magna) and chronic tests (growth test on protozoa, reproduction test on crustaceans and juvenile growth test on two species offish) were performed. Acute toxicity studies revealed diversified species - sensitivity to the tested compounds. Crustaceans Anemia salina were the most resistant to all three pharmaceuticals. Fish also demonstrated low sensitivity to ciprofloxacin and 5-fluorouracil (LC(EC) 50-96h > 100 mg/l). In the survival tests, the greatest harm in respect to fish and crustaceans was demonstrated by 17α-ethinylestradiol, and in the enzymatic tests - by ciprofloxacin. In all chronic tests, the toxic effects of drugs were proven. Tested compounds limited reproduction of crustaceans and growth of protozoa and fry. The risk assessment, conducted on the basis of the PEC/PNEC quotient, showed a significant risk in "relation to aquatic animals caused by the presence of 17α-ethiny lestradiol and 5-fluorouracil in concentrations detected in surface waters. © Copyright by Institute of Envionmental Engineering of the Polish Academy of Sciences, Zabrze, Poland 2011.
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Demand for animal protein for human consumption is rising globally at an unprecedented rate. Modern animal production practices are associated with regular use of antimicrobials, potentially increasing selection pressure on bacteria to become resistant. Despite the significant potential consequences for antimicrobial resistance, there has been no quantitative measurement of global antimicrobial consumption by livestock. We address this gap by using Bayesian statistical models combining maps of livestock densities, economic projections of demand for meat products, and current estimates of antimicrobial consumption in high-income countries to map antimicrobial use in food animals for 2010 and 2030. We estimate that the global average annual consumption of antimicrobials per kilogram of animal produced was 45 mg·kg−1, 148 mg·kg−1, and 172 mg·kg−1 for cattle, chicken, and pigs, respectively. Starting from this baseline, we estimate that between 2010 and 2030, the global consumption of antimicrobials will increase by 67%, from 63,151 ± 1,560 tons to 105,596 ± 3,605 tons. Up to a third of the increase in consumption in livestock between 2010 and 2030 is imputable to shifting production practices in middleincome countries where extensive farming systems will be replaced by large-scale intensive farming operations that routinely use antimicrobials in subtherapeutic doses. For Brazil, Russia, India, China, and South Africa, the increase in antimicrobial consumption will be 99%, up to seven times the projected population growth in this group of countries. Better understanding of the consequences of the uninhibited growth in veterinary antimicrobial consumption is needed to assess its potential effects on animal and human health.
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Triclosan is a widely used antimicrobial compound and emerging environmental contaminant. Although the role of the gut microbiome in health and disease is increasingly well established, the interaction between environmental contaminants and host microbiome is largely unexplored, with unknown consequences for host health. This study examined the effects of low, environmentally relevant levels of triclosan exposure on the fish gut microbiome. Developing fathead minnows (Pimephales promelas) were exposed to two low levels of triclosan over a 7-day exposure. Fish gastrointestinal tracts from exposed and control fish were harvested at four time points: immediately preceding and following the 7-day exposure and after 1 and 2 weeks of depuration. A total of 103 fish gut bacterial communities were characterized by high-throughput sequencing and analysis of the V3-V4 region of the 16S rRNA gene. By measures of both alpha and beta diversity, gut microbial communities were significantly differentiated by exposure history immediately following triclosan exposure. After 2 weeks of depuration, these differences disappear. Independent of exposure history, communities were also significantly structured by time. This first detailed census of the fathead minnow gut microbiome shows a bacterial community that is similar in composition to those of zebrafish and other freshwater fish. Among the triclosan-resilient members of this host-associated community are taxa associated with denitrification in wastewater treatment, taxa potentially able to degrade triclosan, and taxa from an unstudied host-associated candidate division. The fathead minnow gut microbiome is rapidly and significantly altered by exposure to low, environmentally relevant levels of triclosan, yet largely recovers from this short-term perturbation over an equivalently brief time span. These results suggest that even low-level environmental exposure to a common antimicrobial compound can induce significant short-term changes to the gut microbiome, followed by restoration, demonstrating both the sensitivity and resilience of the gut flora to challenges by environmental toxicants. This short-term disruption in a developing organism may have important long-term consequences for host health. The identification of multiple taxa not often reported in the fish gut suggests that microbial nitrogen metabolism in the fish gut may be more complex than previously appreciated.
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We know that animals live in a world dominated by bacteria. In the last 20 years, we have learned that microbes are essential regulators of mucosal immunity. Bacteria, archeas, and viruses influence different aspects of mucosal development and function. Yet, the literature mainly covers findings obtained in mammals. In this review, we focus on two major themes that emerge from the comparative analysis of mammals and amphibians. These themes concern: (i) the structure and functions of lymphoid organs and immune cells in amphibians, with a focus on the gut mucosal immune system; and (ii) the characteristics of the amphibian microbiota and its influence on mucosal immunity. Lastly, we propose to use Xenopus tadpoles as an alternative small-animal model to improve the fundamental knowledge on immunological functions of gut microbiota.
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This study investigated the occurrence of 12 veterinary antibiotics (VAs) and the susceptibility of Escherichia coli (E. coli) in a rural water system that was affected by livestock production in northern China. Each of the surveyed sites was determined with at least eight antibiotics with maximum concentration of up to 450 ng L-1. The use of VAs in livestock farming probably was a primary source of antibiotics in the rivers. Increasing total antibiotics were measured from up- to mid- and downstream in the two tributaries. Eighty-eight percent of the 218 E. coli isolates that were derived from the study area exhibited, in total, 48 resistance profiles against the eight examined drugs. Significant correlations were found among the resistance rates of sulfamethoxazole-trimethoprim, chloromycetin and ampicillin as well as between tetracycline and chlortetracycline, suggesting a possible cross-selection for resistance among these drugs. The E. coli resistance frequency also increased from up- to midstream in the three rivers. E. coli isolates from different water systems showed varying drug numbers of resistance. No clear relationship was observed in the antibiotic resistance frequency with corresponding antibiotic concentration, indicating that the antibiotic resistance for E. coli in the aquatic environment might be affected by factors besides antibiotics. High numbers of resistant E. coli were also isolated from the conserved reservoir. These results suggest that rural surface water may become a large pool of VAs and resistant bacteria. This study contributes to current information on VAs and resistant bacteria contamination in aquatic environments particularly in areas under intensive agriculture. Moreover, this study indicates an urgent need to monitor the use of VAs in animal production, and to control the release of animal-originated antibiotics into the environment.
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Veterinary antibiotics (VAs) are emerging contaminants and enter into soil principally by agricultural application of organic fertilizer. A total of 33 solid animal manures and 17 compost samples from protected vegetable farms in nine areas of China were analyzed for the antibiotic classes of tetracyclines, fluoroquinolones, sulfonamides, and macrolides (17 substances in total). Oxytetracycline was found as a dominant compound in the samples, and its highest concentration reached 416.8 mg kg(-1) in a chicken manure sample from Shouguang, Shandong Province. Among the samples, animal manures (especially pig manure) contained higher VA residues than composts. However, fluoroquinolones exhibited higher persistence in the compost samples than other antibiotic classes. This is particularly the case in the rice husk compost, which contained the highest level of ofloxacin and ciprofloxacin (1334.5 and 1717.4 μg kg(-1) on average, respectively). The veterinary antibiotic profile in the risk husk compost had a good relationship with that in the corresponding manures. The refined commercial compost had the lowest VA residues among the compost samples in general. This implied that composting process might be important to reduce the antibiotic residue. High residue of antibiotics in soil was assumed to be a hazard to ecosystem. This is especially noticeable under current application rates (150 t ha(-1) a(-1)) in protected vegetable farming because over half of the samples exhibited a risk quotient (RQ) >1 for one or more antibiotics.
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The aim of this review paper is to provide a comprehensive overview of different chemical and environmental aspects concerning fluoroquinolone antibiotics as emerging contaminants. A literature survey has been performed based on 204 papers from 1998 to mid-2013, resulting in a dataset consisting out of 4100 data points related to physical-chemical properties, environmental occurrence, removal efficiencies, and ecotoxicological data. In a first part, an overview is given on relevant physical-chemical parameters to better understand the behavior of fluoroquinolones during wastewater treatment and in the environment. Secondly, the route of these antibiotics after their application in both human and veterinary surroundings is discussed. Thirdly, the occurrence of fluoroquinolone residues is discussed for different environmental matrices. The final part of this review provides a tentative risk assessment of fluoroquinolone compounds and their transformation products in surface waters by means of hazard quotients. Overall, this review shows that fluoroquinolone antibiotics have a wide spread use and that their behavior during wastewater treatment is complex with an incomplete removal. As a result, it is observed that these biorecalcitrant compounds are present in different environmental matrices at potentially hazardous concentrations for the aquatic environment. The latter calls for actions on both the consumption as well as the wastewater treatment aspect to diminish the discharge of these biological active compounds.
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To forecast biological responses to changing environments, we need to understand how a species's physiology varies through space and time and assess how changes in physiological function due to environmental changes may interact with phenotypic changes caused by other types of environmental variation. Amphibian larvae are well known for expressing environmentally induced phenotypes, but relatively little is known about how these responses might interact with changing temperatures and their thermal physiology. To address this question, we studied the thermal physiology of grey treefrog tadpoles (Hyla versicolor) by determining whether exposures to predator cues and an herbicide (Roundup) can alter their critical maximum temperature (CTmax) and their swimming speed across a range of temperatures, which provides estimates of optimal temperature (Topt) for swimming speed and the shape of the thermal performance curve (TPC). We discovered that predator cues induced a 0.4°C higher CTmax value, whereas the herbicide had no effect. Tadpoles exposed to predator cues or the herbicide swam faster than control tadpoles and the increase in burst speed was higher near Topt. In regard to the shape of the TPC, exposure to predator cues increased Topt by 1.5°C, while exposure to the herbicide marginally lowered Topt by 0.4°C. Combining predator cues and the herbicide produced an intermediate Topt that was 0.5°C higher than the control. To our knowledge this is the first study to demonstrate a predator altering the thermal physiology of amphibian larvae (prey) by increasing CTmax, increasing the optimum temperature, and producing changes in the thermal performance curves. Furthermore, these plastic responses of CTmax and TPC to different inducing environments should be considered when forecasting biological responses to global warming.
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The aim of the study was to investigate the effects of subchronic exposure of zebrafish (Danio rerio) to a fluoroquinolone norfloxacin, using selected oxidative stress parameters as a target. Toxicity tests were performed on zebrafish according to the OECD Guidelines number 203 and number 215. In the Subchronic Toxicity Test, a significant (P < 0.01) increase in the activity of glutathione peroxidase, glutathione S-transferase, and catalase was found. In the test, norfloxacin did not affect lipid peroxidation and catalytic activity of glutathione reductase. From the results, we can conclude that norfloxacin has a negative impact on specific biochemical processes connected with the production of reactive oxygen species in fish tested.
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We investigated the effects of four commercial formulations of herbicides (glyphosate [GLY], metsulfuron-methyl [MET], bispyribac-sodium [BIS], and picloram [PIC]) individually, and in three 50:50 mixtures (GLY–MET, GLY–BIS, GLY–PIC) on the common toad Rhinella arenarum (Anura: Bufonidae) tadpoles. Enzymatic parameters such as, glutathione S-transferase (GST), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) activities, as well as erythrocyte nuclear abnormalities (ENA) were studied. Interactions between herbicides in mixtures were evaluated and classified as additive, synergistic, or antagonistic. Toxicity results (48-h LC50) showed that PIC was the most toxic herbicide, followed by BIS, GLY, and MET, while GLY–PIC was the most toxic mixture, followed by GLY–BIS, and GLY–MET. All commercial herbicide formulations and their mixtures significantly inhibited BChE activity in exposed tadpoles. The AChE activity was also inhibited by all herbicides and their mixtures, except by GLY–BIS. The inhibition of GST activity was only significant for GLY, MET, PIC, and GLY–MET. A significant increase in the frequency of ENA was found for tadpoles exposed either to commercial herbicide formulations or to mixtures, except for GLY. All the mixtures showed synergism for BChE activity while for AChE only the GLY–MET and GLY–PIC mixtures acted synergistically. GLY–MET showed synergism for GST, whereas for ENA, the mixture GLY–BIS was antagonistic. This study with R. arenarum tadpoles demonstrates that the interactions between three of the most intensively used herbicides in soybean crops results in synergistic effects on mortality and neurotoxicity and synergistic or additive effects in genotoxicity.
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In this study, amphibian tadpoles of Hypsiboas pulchellus were exposed to herbicide Liberty(®), which contains glufosinate ammonium (GLA), for 48 h to the following concentrations: 0 (control), 3.55, 4.74, 6.32, 8.43, 11.25, 15, 20, 26.6, and 35.5 mg GLA L(-1). Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities, as well as swimming capabilities (swimming speed and mean distance) were measured in tadpoles whose concentrations displayed survival rates >85 %. Our results reveal that sublethal concentrations of GLA significantly inhibited both AChE and BChE activities in tadpoles with respect to the control, showing a concentration-dependent inhibitory effect. The highest inhibition percentages of AChE (50.86 %) and BChE (53.02 %) were registered in tadpoles exposed to 15 mg GLA L(-1). At this concentration, a significant increase of the swimming speed and mean distance were found in exposed tadpoles with respect to the control, as well as a negative and significant correlation between swimming speed and BChE activity, thus suggesting that this enzyme inhibition is related to an increase in swimming speed. Therefore, exposure of tadpoles to GLA in the wild at concentrations similar to those tested here may have adverse consequences at population level because neurotransmission and swimming performance are essential for tadpole performance and survival.
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An urban watershed in northern New Jersey was studied to determine the presence of four classes of antibiotic compounds (macrolides, fluoroquinolones, sulfonamides, and tetracyclines) and six degradates in the water column and bottom sediments upstream and downstream from the discharges of two wastewater treatment plants (WWTPs) and a drinking-water intake (DWI). Many antibiotic compounds in the four classes not removed by conventional WWTPs enter receiving waters and partition to stream sediments.
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The relationship between the genes and the effects attributed to them has been object of many studies, especially those seeking to establish the response of genes to environmental prod. The aim of this work was to establish a standard system to monitor effluents by using juvenile Nile tilapia (Oreochromis niloticus) as a bioindicator of genotoxicity, utilizing micronuclei test and comet assay. For this, the fish were exposed during 24, 48, 72 and 240 hours (10 days), to water samples collected at two sites of the Itajaí-Açú River: Ilhota and Blumenau, in the Santa Catarina State, Brazil. For positive control the herbicide 2,4-D (75 ppm) was utilized, and the negative control of each fish were the values obtained before the exposure to the river water, termed time zero (T 0). Water samples from both sites of the Itajaí-Açú River showed significant genotoxic effects in erythrocytes of the exposed fishes. The comet assay was a more sensitive test to detect genotoxic damage in shorter exposure times (24 and 48 hours) than the micronuclei test. Avaliação da genotoxicidade em tilápias (Oreochromis niloticus) expostas às águas de dois locais do Rio Itajaí-Açu (SC, Brasil) Resumo A relação entre os genes e os efeitos a eles atribuídos tem sido objeto de muitos estudos, sobretudo aqueles que buscam estabelecer a resposta dos genes aos estímulos ambientais. Este estudo teve por objetivo padronizar um sistema de monitoramento de efluentes tendo juvenis de peixes exóticos da espécie tilápia (Oreochromis niloticus) como bioindicadores de genotoxicidade, utilizando as técnicas do teste do micronúcleo e ensaio cometa. Para isto, os peixes foram expostos no período de 24, 48, 72 e 240 horas (10 dias) às amostras de água coletadas em dois locais do Rio Itajaí-Açú: Ilhota e Blumenau, no Estado de Santa Catarina, Brasil. De controle positivo foi utilizado o herbicida 2,4-D (75ppm), e para o controle negativo foram atribuídos os valores obtidos de cada peixe antes da exposição às águas do rio, determinado como tempo zero (T 0). As amostras de água de ambos os pontos de coleta do Rio Itajaí-Açú mostraram efeitos genotóxicos significativos nos eritrócitos dos peixes expostos. O ensaio cometa mostrou ser mais sensível para detectar danos genotóxicos, nos menores tempos de exposição em relação ao teste do micronúcleo. Palavras-chave: genotoxicidade, ensaio cometa, teste do micronúcleo, Oreochromis niloticus, bioindicador.
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