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1.
Environ Pollut ; 291: 118095, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34537598

RESUMO

Ciprofloxacin (CFX) and ofloxacin (OFX) are two of the most often used fluoroquinolone antibiotics, and their residues are found in large amounts in various aquatic settings. However, the toxicity tests of CFX using eukaryotic organisms such as Daphnia magna are inadequate, and the test result of OFX is currently unknown. Therefore, the chronic toxicity test for D. magna was performed during 42 days under exposure to CFX and OFX concentrations of 50, 500, and 5000 µg L-1. All exposure conditions did not cause mortality for D. magna. CFX exposure at 500 µg L-1 resulted in an earlier oogenesis date and increased brood size in the second birth. The Poisson-based generalized linear mixed-effects model revealed that the reduction of fertility was statistically significant for the CFX and OFX exposures at 5000 µg L-1. On the other hand, the production of dead eggs as offspring degradation was also found significantly as maternal D. magna exposed to antibiotics at 5000 µg L-1. In addition, following long-term exposure to antibiotics, maternal adaptation to antibiotics was established for offspring deterioration and fertility. However, the OFX exposure showed that the fertility-suppressed effects continued for a longer period than the CFX exposure. Although no rational explanation has yet been given for the more substantial effect of OFX on reducing fertility than CFX, molecular cell biology and symbiotic microbial flora derived from previous studies could explain our ecotoxicological results. This study is the first report for the OFX chronic toxicities on D. magna by comparing it to the toxicity of CFX. Our study contributes to guiding the future impact assessment of fluoroquinolone antibiotic pollution on ecosystems, including the need for new statistical methods in ecotoxicological studies.


Assuntos
Daphnia , Poluentes Químicos da Água , Animais , Ciprofloxacina/toxicidade , Ecossistema , Ecotoxicologia , Ofloxacino/toxicidade , Reprodução , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
2.
Front Immunol ; 12: 668962, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34385999

RESUMO

Neuromuscular blocking agents (NMBAs) like atracurium and rocuronium as well as fluoroquinolones (FQs) cause mast cell-mediated anaphylaxis by activating Mas-related G protein-coupled receptor X2 (MRGPRX2), but many questions remain unanswered. Here, we address three of them, namely whether primary human mast cells show similar activation by these drugs as murine mast cells and mast cell lines, how sugammadex protects from atracurium-induced MRGPRX2-mediated mast cell activation, and why some but not all patients treated with rocuronium develop anaphylaxis. We used peripheral blood-derived cultured mast cells from healthy donors and patients, assessed mast cell activation and degranulation by quantifying intracellular calcium and CD63 expression, respectively, and made use of MRGPRX2-silencing, via electroporation with Dicer-substrate small interfering RNAs, and single cell flow cytometric analyses. Atracurium, ciprofloxacin, and levofloxacin activated and degranulated primary human mast cells, but only MRGPRX2-positive and not MRGPRX2-negative or -silenced mast cells. Sugammadex attenuated the atracurium-induced and MRGPRX2-mediated activation and degranulation of human mast cells by reducing free atracurium levels. The mast cells of patients with IgE-independent anaphylaxis to rocuronium were similar, in their MRGPRX2 expression and function, to those of patients with IgE-mediated anaphylaxis. These findings further improve our understanding of the role and relevance of MRGPRX2-driven mast cell activation in anaphylactic reactions to NMBAs and FQs and may help to improve their prediction, prevention, and treatment.


Assuntos
Anafilaxia/induzido quimicamente , Antibacterianos/toxicidade , Degranulação Celular/efeitos dos fármacos , Hipersensibilidade a Drogas/etiologia , Mastócitos/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , Fármacos Neuromusculares não Despolarizantes/toxicidade , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Anafilaxia/imunologia , Anafilaxia/metabolismo , Atracúrio/toxicidade , Sinalização do Cálcio/efeitos dos fármacos , Células Cultivadas , Ciprofloxacina/toxicidade , Hipersensibilidade a Drogas/imunologia , Hipersensibilidade a Drogas/metabolismo , Humanos , Imunoglobulina E/imunologia , Levofloxacino/toxicidade , Mastócitos/imunologia , Mastócitos/metabolismo , Proteínas do Tecido Nervoso/genética , Receptores Acoplados a Proteínas G/genética , Receptores de Neuropeptídeos/genética , Rocurônio/toxicidade , Fatores de Tempo
3.
Environ Int ; 157: 106842, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34438231

RESUMO

Although nanoplastics/microplastics (NPs/MPs) may interact with co-contaminants (e.g. antibiotics) in aquatic systems, little is known about their combined toxicity. Here, we compared the individual toxicity of NPs/MPs or ciprofloxacin (CIP, a very commonly detected antibiotic) and their combined toxicity toward a unicellular cyanobacterium Synechocystis sp. in terms of the cellular responses and metabolomic analysis. We found that CIP exhibited an antagonistic effect with NPs/MPs due to its adsorption onto the surface of NPs/MPs. Particle size-dependent toxic effects of NPs/MPs were observed. Reactive oxygen species (ROS) was verified as an important factor for NPs/MPs to inhibit cell growth, other than for CIP. Metabolomics further revealed that Synechocystis sp. up-regulated glycerophospholipids, amino acids, nucleotides, and carbohydrates to tolerate CIP pressure. NPs/MPs downregulated the TCA cycle and glycerophospholipids metabolism and impaired the primary production and membrane integrity via adhesion with Synechocystis sp.. Additionally, the toxicity of NPs/MPs throughout ten growth cycles at a sublethal concentration unveiled its potential risks in interfering with metabolism. Collectively, our findings provide insights into the joint ecotoxicity of NPs/MPs and antibiotics, and highlight the potential risks of co-pollutants at environmental relevant concentrations.


Assuntos
Synechocystis , Poluentes Químicos da Água , Ciprofloxacina/toxicidade , Microplásticos , Plásticos , Poluentes Químicos da Água/análise
4.
J Hazard Mater ; 419: 126466, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34323704

RESUMO

Direct Z-scheme Bi5O7I/UiO-66-NH2 (denoted as BU-x) heterojunction photocatalysts were successfully constructed through ball-milling method. Photocatalytic activities of the as-prepared BU-x samples were determined by using a typical fluoroquinolone antibiotic, ciprofloxacin (CIP). All BU-x heterojunctions exhibited better CIP removal performances than that of pristine Bi5O7I and UiO-66-NH2 upon exposure to white light irradiation. In comparison, the heterojunction with UiO-66-NH2 content of 50 wt% (BU-5) showed excellent structural stability and the optimal adsorption-photodegradation efficiency for the CIP removal. The removal efficiency of CIP (10 mg/L) over BU-5 (0.75 g/L) achieved 96.1% within 120 min illumination. Meanwhile, the effect of photocatalyst dosage, pH and inorganic anions were systemically explored. Reactive species trapping experiments, electron spin resonance (ESR) signals, Mott-Schottky measurements and density functional theory (DFT) simulation revealed that the photo-generated holes (h+), hydroxyl radical (·OH) and superoxide radical (·O2-) played crucial roles in CIP degradation. This result can be ascribed to that the unique Z-scheme charge transfer configuration retained the excellent redox capacities of Bi5O7I and UiO-66-NH2. Meanwhile, the CIP degradation pathways and the toxicity of various intermediates were subsequently analyzed. This work provided a feasible idea for removing antibiotics by bismuth-rich bismuth oxyhalide/MOF-based heterostructured photocatalysts.


Assuntos
Bismuto , Ciprofloxacina , Antibacterianos/toxicidade , Catálise , Ciprofloxacina/toxicidade , Fotólise
5.
Environ Res ; 200: 111396, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34062201

RESUMO

The knowledge about the effects of pharmaceuticals on aquatic organisms has been increasing in the last decade. However, due to the variety of compounds presents in the aquatic medium, exposure scenarios and exposed organisms, there are still many gaps in the knowledge on how mixtures of such bioactive compounds affect exposed non target organisms. The crayfish Procambarus clarkii was used to analyze the toxicity effects of mixtures of ciprofloxacin, flumequine and ibuprofen at low and high concentrations (10 and 100 µg/L) over 21 days of exposure and to assess the recovery capacity of the organism after a depuration phase following exposure during additional 7 days in clean water. The crayfish accumulated the three compounds throughout the entire exposure in the hepatopancreas. The exposure to the mixture altered the abundance of proteins associated with different cells functions such as biotransformation and detoxification processes (i.e. catalase and glutathione transferase), carbohydrate metabolism and immune responses. Additionally changes in expression of genes encoding antioxidant enzymes and in activity of the corresponding enzymes (i.e. superoxide dismutase, glutathione peroxidase and glutathione transferase) were reported. Alterations at different levels of biological organization did not run in parallel under all circumstances and can be related to changes in the redox status of the target tissue. No differences were observed between control and exposed organisms for most of selected endpoints after a week of depuration, indicating that exposure to the drug mixture did not produce permanent damage in the hepatopancreas of P. clarkii.


Assuntos
Preparações Farmacêuticas , Poluentes Químicos da Água , Animais , Astacoidea , Ciprofloxacina/metabolismo , Ciprofloxacina/toxicidade , Fluoroquinolonas , Hepatopâncreas/metabolismo , Ibuprofeno/toxicidade , Análise Multinível , Estresse Oxidativo , Preparações Farmacêuticas/metabolismo , Proteômica , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
6.
Sci Total Environ ; 789: 147887, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34051493

RESUMO

Plastic pollution has become a global environmental threat, and its potential to affect the bioavailability and toxicity of pharmaceuticals to aquatic organism are of growing concern. However, little is known regarding the combined toxicity of micro/nano-plastics and pharmaceuticals to benthic organisms in sediments. Thus, we employed a freshwater benthic bivalve, Corbicula fluminea (C. fluminea), to investigate the individual and co-toxicity of model plastics, microscopic fluorescent polystyrene (PS) (PS nano-plastic (PS-NP) and PS micro-plastic (PS-MP), 80 nm and 6 µm, respectively) and the common antibiotic ciprofloxacin (CIP) in formulated sediments. Our results suggest that oxidative damage and neurotoxicity were confirmed to occur in C. fluminea in all the treatments. The oxidative damage in the digestive glands reduced the clam ability to scavenge free radicals, causing severe tissue damage to the digestive glands of C. fluminea. Filtration rates of C. fluminea were significantly decreased in a concentration-dependent manner across all the treatments, which might be due to the inhibition of acetylcholinesterase activities. Interactions between CIP and micro/nano-plastic were observed, whereby the presence of PS decreased the toxicity of CIP in the digestive glands but aggravated the C. fluminea siphoning inhibition rate in the nano-plastic co-treatments group; in addition, the CIP toxicity to C. fluminea decreased because that the concentration of free dissolved CIP was lowered by micro/nano-PS. Taken together, the current study could contribute greatly to evaluating the ecological risk of CIP and PS in aquatic environments and sheds light on potential issues of food safety caused by both emerging pollutants.


Assuntos
Corbicula , Poluentes Químicos da Água , Animais , Ciprofloxacina/toxicidade , Água Doce , Plásticos , Poliestirenos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
7.
Sci Total Environ ; 779: 146503, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34030234

RESUMO

In order to explore the impact of antibiotics on the bacterial metabolic cycling of nitrate within contaminated soil and groundwater environments, we compared the effects of polymyxin B (PMB) and ciprofloxacin (CIP) concentration gradients on the distribution and activity of a wild type (WT) and a flagella deficient mutant (Δflag) of Shewanella oneidensis MR-1 in a microfluidic gradient chamber (MGC). Complementary batch experiments were performed to measure bacteriostatic versus bactericidal concentrations of the two antibiotics, as well as their effect on nitrate reduction. Prior work demonstrated that PMB disrupts cell membranes while CIP inhibits DNA synthesis. Consistent with these modes of action, batch results from this work show that PMB is bactericidal at lower concentrations than CIP relative to their respective minimum inhibitory concentrations (MICs) (≥5× MICPMB vs. ≥20× MICCIP). Concentration gradients from 0 to 50× the MIC of both antibiotics were established in the MGC across a 2-cm interconnected pore network, with nutrients injected at both concentration boundaries. The WT cells could only access and reduce nitrate in regions of the MGC with PMB at <18× MICPMB, whereas this occurred with CIP up to 50× MICCIP; and cells extracted from these MGCs showed no antibiotic resistance. The distribution of Δflag cells was further limited to lower antibiotic concentrations (≤1× MICPMB, ≤43× MICCIP) due to inability of movement. These results indicate that S. oneidensis access and reduce nitrate in bactericidal regions via chemotactic migration without development of antibiotic resistance, and that this migration is inhibited by acutely lethal bactericidal levels of antibiotics.


Assuntos
Antibacterianos , Nitratos , Antibacterianos/toxicidade , Ciprofloxacina/toxicidade , Resistência Microbiana a Medicamentos/genética , Testes de Sensibilidade Microbiana , Microfluídica , Nitratos/toxicidade , Shewanella
8.
Sci Total Environ ; 773: 145041, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33940712

RESUMO

This study aims to offer insights into how ciprofloxacin (CIP) impact bacterial community structures in the Sponge-MBR process when CIP is spiked into hospital wastewater. We found that the CIP toxicity decreased richness critical phylotypes such as phylum class ẟ-, ß-, É£-proteobacteria, and Flavobacteria that co-respond to suppress denitrification and cake fouling to 37% and 28% respectively. Cluster analysis shows that the different community structures were formed under the influence of CIP toxicity. CIP decreased attached growth biomass by 2.3 times while increasing the concentration of permeate nitrate by 3.8 times, greatly affecting TN removal by up to 26%. Ammonia removal was kept stable by inflating the ammonia removal rate (p < 0.003), with the wealthy Nitrospira genus guaranteeing the nitrification activity. In addition, we observed an increasing richness of Chloroflexi and Planctomycetes, which may play a role in fouling reduction in the Sponge-MBR. Therefore, if the amount of antibiotics in hospital wastewater continues to increase, it is so important to extend biomass retention for denitrification recovery.


Assuntos
Ciprofloxacina , Microbiota , Reatores Biológicos , Ciprofloxacina/toxicidade , Nitrificação , Águas Residuárias
9.
Sci Total Environ ; 771: 144787, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33548726

RESUMO

Ciprofloxacin (CIP), a widely used fluoroquinolone antibiotic, is frequently detected in aqueous environments, and could be assimilated by vegetable plants to possess potential threats to human and animal health through food chains. However, plant uptake of CIP in different chemical speciation has still far from clear now. Thus, the toxicity and uptake of CIP by rice plants were investigated under different solution pH, owing to its contribution to different chemical speciation of CIP. Results display that high pH-driven changes of CIP from cation (CIP+) to anion (CIP-) decreased its adsorption and uptake by excised roots and intact plants, respectively. However, CIP concentrations in roots, stems and leaves all exhibited no significant differences with increasing solution pH. Moreover, six intermediates of CIP were detected and two possible transformation pathways were proposed in rice plants, including firstly oxidation and following consecutive cleavage of piperazine ring. After accumulated in plant tissues, CIP significantly inhibited the plant growth, decreased the photosynthetic pigments contents and enhanced the antioxidant enzyme activities in a concentration-dependent manner. Besides, high pH exacerbated the growth inhibition and changed the oxidative damage responses of rice plants to CIP. These findings indicate that the uptake and toxicity of CIP in rice plants were influenced by solution pH-driven changes of its chemical speciation.


Assuntos
Ciprofloxacina , Oryza , Adsorção , Ciprofloxacina/toxicidade , Fluoroquinolonas , Humanos , Água
10.
Nucleic Acids Res ; 49(3): 1581-1596, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33434265

RESUMO

DNA gyrase, a type II topoisomerase found predominantly in bacteria, is the target for a variety of 'poisons', namely natural product toxins (e.g. albicidin, microcin B17) and clinically important synthetic molecules (e.g. fluoroquinolones). Resistance to both groups can be mediated by pentapeptide repeat proteins (PRPs). Despite long-term studies, the mechanism of action of these protective PRPs is not known. We show that a PRP, QnrB1 provides specific protection against fluoroquinolones, which strictly requires ATP hydrolysis by gyrase. QnrB1 binds to the GyrB protein and stimulates ATPase activity of the isolated N-terminal ATPase domain of GyrB (GyrB43). We probed the QnrB1 binding site using site-specific incorporation of a photoreactive amino acid and mapped the crosslinks to the GyrB43 protein. We propose a model in which QnrB1 binding allosterically promotes dissociation of the fluoroquinolone molecule from the cleavage complex.


Assuntos
Proteínas de Bactérias/metabolismo , DNA Girase/metabolismo , Inibidores da Topoisomerase II/toxicidade , Trifosfato de Adenosina/metabolismo , Bacteriocinas/toxicidade , Ciprofloxacina/toxicidade , DNA/metabolismo , Escherichia coli/enzimologia , Hidrólise , Compostos Orgânicos/toxicidade , Xanthomonas
11.
Environ Sci Pollut Res Int ; 28(20): 25680-25691, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33469791

RESUMO

The global detection of ciprofloxacin and atrazine in soil is linked to intensive anthropogenic activities in agriculture and inadvertent discharge of industrial wastes to the environment. Nauphoeta cinerea is a terrestrial insect with cosmopolitan distribution and great environmental function. The current study probed the neurobehavioral and cellular responses of N. cinerea singly and jointly exposed to atrazine (1.0 and 0.5 µg g-1 feed) and ciprofloxacin (0.5 and 0.25 µg g-1 feed) for 63 days. Results demonstrated that the reductions in the body rotation, maximum speed, turn angle, path efficiency, distance traveled, episodes, and time of mobility induced by atrazine or ciprofloxacin per se was exacerbated in the co-exposure group. The altered exploratory and locomotor in insects singly and jointly exposed to ciprofloxacin and atrazine were verified by track plots and heat maps. Furthermore, we observed a decrease in acetylcholinesterase and anti-oxidative enzyme activities with concomitant elevation in the levels of lipid peroxidation, nitric oxide, and reactive oxygen and nitrogen species were significantly intensified in the midgut, hemolymph, and head of insects co-exposed to ciprofloxacin and atrazine. In conclusion, exposure to binary mixtures of ciprofloxacin and atrazine elicited greater locomotor and exploratory deficits than upon exposure to the individual compound by inhibiting acetylcholinesterase activity and induction of oxido-inflammatory stress responses in the insects. N. cinerea may be a usable model insect for checking contaminants of ecological risks.


Assuntos
Atrazina , Ciprofloxacina , Baratas/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Acetilcolinesterase/metabolismo , Animais , Atrazina/toxicidade , Ciprofloxacina/toxicidade , Baratas/metabolismo , Peroxidação de Lipídeos , Estresse Oxidativo
12.
Environ Pollut ; 268(Pt B): 115494, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33152600

RESUMO

The present study deals with the adsorption of antibiotic Ciprofloxacin (CPXO) and anti-inflammatory agent Diclofenac (DCF) on Grass nanocellulose (GNC) extracted from Cyprus rotundas grass. The adsorbent GNC was characterised using various microscopic, elemental and spectroscopic analysis to monitor the physicochemical alterations of the surface before and after adsorption. The size of the converted nanocellulose was found to be 40-50 nm. The experimental measures influencing the adsorption of CPXO and DCF that were optimised are initial solution pH, GNC dosage, temperature and initial concentration of the adsorbate. Halsey isotherm model and pseudo-second order kinetic model agreed best with the experimental outcome for both the adsorbate. The maximum adsorption capacity of GNC were 227.223 and 192.307 mg/g for CPXO and DCF respectively. Phytotoxicity studies were performed using 6 different types of seeds to evaluate the effect of GNC treated effluent on plants. Similarly, acute fish toxicity on zebra fish analysis showed to have lesser mortality rate of the effluent after adsorption of CPXO and DCF on GNC.


Assuntos
Diclofenaco , Poluentes Químicos da Água , Adsorção , Ciprofloxacina/toxicidade , Diclofenaco/toxicidade , Concentração de Íons de Hidrogênio , Cinética , Poaceae , Termodinâmica , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
13.
Ecotoxicology ; 30(8): 1598-1609, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33180212

RESUMO

Antibiotics are recently recognized as a group of emerging environmental contaminants that are frequently detected in various environmental matrixes. Relative root elongation (RRE) test is a rapid and effective strategy to evaluate the water/soil quality and the toxic effects of environmental contaminants on plants. In the present study, we examine the toxicity effect of ciprofloxacin (CIP), norfloxacin (NOR), and tetracycline (TET) to pakchoi individually and in combinations. Both independent action (IA) and concentration addition (CA) models are used for toxicity assessment. Results showed that the EC50 values of CIP, NOR, and TET are 193.59, 60.81, and 40.37 µM, respectively. Combinations of TET + CIP and TET + NOR caused more inhibitory effects on root elongation than those of CIP + NOR. Toxic Unit (TU) and Synergistic Ratio (SR) analysis showed that the relatively lower (higher) EC values are observed in the combinations with lower (higher) antibiotic concentrations, suggesting an effect of low-dose synergism and high-dose antagonism. The reliability of the simulation results from IA and CA models to predict that combined toxicity is highly dependent upon the results from the analysis of TU or SR.


Assuntos
Antibacterianos , Tetraciclina , Antibacterianos/toxicidade , Ciprofloxacina/toxicidade , Reprodutibilidade dos Testes , Solo , Tetraciclina/toxicidade
14.
Environ Pollut ; 270: 116071, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33218776

RESUMO

Discharged carbon nanotubes (CNTs) likely interact with co-existing organic contaminants (OCs) and pose joint toxicity to environmental microbes. Herein, hydrophobic pentachlorophenol (PCP) and hydrophilic ciprofloxacin (CIP) were used as representative OCs and their joint toxicities with CNTs to Bacillus subtilis were systematically investigated at cellular, biochemical, and omics levels. The 3-h bacterial growth half inhibitory concentrations of CNTs, PCP, and CIP were 12.5 ± 2.6, 3.5 ± 0.5, and 0.46 ± 0.03 mg/L, respectively, and they all could damage cell membrane, increase intracellular oxidative stress, and alter bacterial metabolomics and transcriptomics; while CNTs-PCP and CNTs-CIP binary exposures exhibited distinct additive and synergistic toxicities, respectively. CNTs increased bacterial bioaccumulation of PCP and CIP via destabilizing and damaging cell membrane. PCP reduced the bioaccumulation of CNTs, while CIP had no significant effect; this difference could be owing to the different effects of the two OCs on cell-surface hydrophobicity and CNTs electronegativity. The additive toxicity outcome upon CNTs-PCP co-exposure could be a result of the balance between the increased toxicity from increased PCP bioaccumulation and the decreased toxicity from decreased CNTs bioaccumulation. The increased bioaccumulation of CIP contributed to the synergistic toxicity upon CNTs-CIP co-exposure, as confirmed by the increased inhibition of topoisomerase Ⅳ activity and interference in gene expressions regulating ABC transporters and lysine biosynthesis. The findings provide novel insights into environmental risks of CNTs.


Assuntos
Nanotubos de Carbono , Pentaclorofenol , Bacillus subtilis , Membrana Celular , Ciprofloxacina/toxicidade , Nanotubos de Carbono/toxicidade , Pentaclorofenol/toxicidade
15.
Environ Toxicol ; 36(5): 887-902, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33382204

RESUMO

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.


Assuntos
Antioxidantes , Poluentes Químicos da Água , Animais , Antioxidantes/metabolismo , Ciprofloxacina/toxicidade , Fluoroquinolonas/toxicidade , Brânquias/metabolismo , Íons , Fígado , Estresse Oxidativo , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
16.
Sci Total Environ ; 750: 142370, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182210

RESUMO

Plastic debris is ubiquitous in aquatic systems and has been proven vehicles for the transport of various pollutants including trace organic compounds. Nanoplastics have large specific surface area and hydrophobic characteristics and therefore are capable of adsorbing other organic or inorganic chemicals from the environment. Antibiotics, as another class of emerging contaminants, have raised significant research concern in recent years as they pose threats to the ecosytems and human health. Nevertheless, little information is available on the adsorption behaviors of antibiotics onto nano-sized plastics. The toxicity of combined nanoplastics and antibiotics is also largely unknown. In this study, the physicochemical and thermodynamic interactions between representative nanoplastics, which containing a carboxyl functional group of polystyrene nanoplastics (PS-COOH), and typical antibiotic, i.e., ciprofloxacin (CIP) were investigated in a batch adsorption experiment. The specific thermodynamic correlation function of PS-COOH combined with CIP was obtained through isothermal titration microcalorimetry (ITC) analysis. The adsorption kinetics and isotherm of CIP on PS-COOH closely fit the pseudo-second-order kinetic model (r2 = 0.99) and Freundlich isotherm (r2 = 0.99). The ITC results showed that the adsorption reaction of PS-COOH with CIP was a spontaneous exothermic reaction. The adsorption of antibiotics on nanoplastics may aggravate the negative impacts of these two pollutants on aqueous ecosystems, and we hypothesized that would be reflected in the survival rate of model organism of Caenorhabditis elegans when exposed to this combination. This work used a mechanistic approach to unravel the adsorption behavior of antibiotics on nanoplastics and shed light on their potential impact on aquatic ecosystems.


Assuntos
Plásticos , Poluentes Químicos da Água , Adsorção , Ciprofloxacina/toxicidade , Ecossistema , Cinética , Plásticos/toxicidade , Poliestirenos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
17.
Aquat Toxicol ; 228: 105632, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33010638

RESUMO

An experiment was carried out using microcosms to evaluate the impact of the fluoroquinolone antibiotic on nematode trophic groups structure and bacterial abundance. Sediment samples were experimentally enriched with four increasing doses of ciprofloxacin [D1 (50 ppm), D2 (100 ppm), D3 (200 ppm) and D4 (500 ppm)] and compared to non-enriched sediments (used as control). Ciprofloxacin changed the trophic composition of nematodes taxa where the relative abundance of microvores (M), epigrowth feeders (EF) and ciliate consumers (CF), raised in a control microcosm, was highly affected and significantly decreased in response to the increasing doses. Nevertheless, the abundance of deposit feeders (DF), optional predators (FP) and exclusive predators (Pr) showed a significant increase. Results from the multivariate analysis showed a clear impact of this antibiotic on nematode trophic assemblages. Microcosms treated with the three highest doses [D2, D3 and D4] were different from the control. The exceptions were those treated with the lowest dose, D1, and which were grouped with the control. The SIMPER analysis results showed that the average dissimilarity continuously increased in the treated microcosms compared to the control. Furthermore, our results have shown that ciprofloxacin also leads to a significant decrease in bacterial density with the highest dose, which could explain the results obtained for nematode trophic groups distribution. Thus, the bacteriophages nematodes only use bacteria as a nutrition source and the lack or presence in small quantity of this food could induce a decrease in their abundance as well as changing of nematodes groups repartition. Our work demonstrates that the nematode responses were dependent on sediment enrichment with ciprofloxacin and opens new perspectives on the potential impact of antibiotics on functional nematode diversity.


Assuntos
Antibacterianos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Ciprofloxacina/toxicidade , Ecossistema , Sedimentos Geológicos/química , Nematoides/fisiologia , Animais , Bactérias/efeitos dos fármacos , Análise por Conglomerados , Geografia , Sedimentos Geológicos/microbiologia , Região do Mediterrâneo , Análise Multivariada , Nematoides/efeitos dos fármacos , Densidade Demográfica , Análise de Componente Principal , Poluentes Químicos da Água/toxicidade
18.
Environ Toxicol Pharmacol ; 80: 103505, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33002593

RESUMO

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.


Assuntos
Antibacterianos/toxicidade , Ciprofloxacina/toxicidade , Poliquetos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Catalase/metabolismo , Colinesterases/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Poliquetos/fisiologia
19.
Sci Rep ; 10(1): 15026, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929164

RESUMO

It is important that antibiotics prescriptions are based on antimicrobial susceptibility data to ensure effective treatment outcomes. The increasing availability of next-generation sequencing, bacterial whole genome sequencing (WGS) can facilitate a more reliable and faster alternative to traditional phenotyping for the detection and surveillance of AMR. This work proposes a machine learning approach that can predict the minimum inhibitory concentration (MIC) for a given antibiotic, here ciprofloxacin, on the basis of both genome-wide mutation profiles and profiles of acquired antimicrobial resistance genes. We analysed 704 Escherichia coli genomes combined with their respective MIC measurements for ciprofloxacin originating from different countries. The four most important predictors found by the model, mutations in gyrA residues Ser83 and Asp87, a mutation in parC residue Ser80 and presence of the qnrS1 gene, have been experimentally validated before. Using only these four predictors in a linear regression model, 65% and 93% of the test samples' MIC were correctly predicted within a two- and a four-fold dilution range, respectively. The presented work does not treat machine learning as a black box model concept, but also identifies the genomic features that determine susceptibility. The recent progress in WGS technology in combination with machine learning analysis approaches indicates that in the near future WGS of bacteria might become cheaper and faster than a MIC measurement.


Assuntos
Antibacterianos/toxicidade , Ciprofloxacina/toxicidade , Farmacorresistência Bacteriana , Genes Bacterianos , Aprendizado de Máquina , DNA Girase/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Concentração Inibidora 50 , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mutação , Testes de Toxicidade/métodos
20.
Water Res ; 185: 116286, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32818732

RESUMO

Chemical speciation of ionizable antibiotics greatly affects its photochemical kinetics and mechanisms; however, the mechanistic impact of chemical speciation is not well understood. For the first time, the impact of different dissociation species (cationic, zwitterionic and anionic forms) of ciprofloxacin (CIP) on its photocatalytic transformation fate was systematically studied in a UVA/LED/TiO2 system. The dissociation forms of CIP at different pH affected the photocatalytic degradation kinetics, transformation products (TPs) formation as well as degradation pathways. Zwitterionic form of CIP exhibited the highest degradation rate constant (0.2217 ± 0.0179 min-1), removal efficiency of total organic carbon (TOC) and release of fluoride ion (F-). Time-dependent evolution profiles on TPs revealed that the cationic and anionic forms of CIP mainly underwent piperazine ring dealkylation, while zwitterionic CIP primarily proceeded through defluorination and piperazine ring oxidation. Moreover, density functional theory (DFT) calculation based on Fukui index well interpreted the active sites of different CIP species. Potential energy surface (PES) analysis further elucidated the reaction transition state (TS) evolution and energy barrier (ΔEb) for CIP with different dissociation species after radical attack. This study provides deep insights into degradation mechanisms of emerging organic contaminants in advanced oxidation processes associated to their chemical speciation.


Assuntos
Ciprofloxacina , Poluentes Químicos da Água , Antibacterianos/toxicidade , Ciprofloxacina/análise , Ciprofloxacina/toxicidade , Cinética , Oxirredução , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
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