Second-, third- and fourth-generation quinolones: Ecotoxicity effects on Daphnia and Ceriodaphnia species

Cyclodextrin-based ternary supramolecular deep eutectic solvents for efficient extraction and analysis of trace quinolones and sulfonamides in wastewater by adjusting pH

BACKGROUND

Antibiotics residues can accelerate the growth of drug-resistant bacteria and harm the ecological environment. Under the effect of enrichment and biomagnification, the emergence of drug-resistant pathogenic bacteria may eventually lead to humans being ineffective to drugs in the face of bacterial or fungal disease infections in the future. It is urgent to develop an efficient separation medium and analytical method for simultaneous extraction and determination of antibiotics in the water environment.

RESULTS

This work doped 2,6-Di-O-methyl-β-cyclodextrin, randomly methyl-β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin with thymol:fatty acid respectively to construct non-covalent interaction-dominated pH-responsive ternary supramolecular deep eutectic solvents (SUPRADESs), which can undergo a hydrophilic/hydrophobic transition with aqueous phase to achieve an efficient microextraction. Semi-empirical method illustrated that SUPRADESs have a wide range of hydrogen bond receptor sites. We developed a SUPRADES-based analytical method combined with liquid chromatography-triple quadrupole mass spectrometry for the extraction and determination of trace quinolones and sulfonamides in wastewater. The overall limits of detection of the method were 0.0021-0.0334 ng mL-1 and the limits of quantification were 0.0073-0.1114 ng mL-1. The linearity maintained good in the spiked level of 0.01-100 ng mL-1 (R2 > 0.99). The overall enrichment factors of the method were 157-201 with lower standard deviations (≤8.7).

SIGNIFICANCE

The method gave an extraction recovery of 70.1-115.3 % for 28 antibiotics in livestock farming wastewater samples from Zhejiang, China, at trace levels (minimum 0.5 ng mL-1). The results demonstrated that inducing the phase transition between SUPRADES and aqueous phase by adjusting pH for extraction is a novel and efficient pretreatment strategy. To our knowledge, this is the first application of cyclodextrin-based ternary SUPRADESs with pH-responsive reversible hydrophobicity-hydrophilicity transition behavior in wastewater analysis.

A Review on Fluoroquinolones' Toxicity to Freshwater Organisms and a Risk Assessment

Fluoroquinolones (FQs) have achieved significant success in both human and veterinary medicine. However, regulatory authorities have recommended limiting their use, firstly because they can have disabling side effects; secondly, because of the need to limit the spread of antibiotic resistance. This review addresses another concerning consequence of the excessive use of FQs: the freshwater environments contamination and the impact on non-target organisms. Here, an overview of the highest concentrations found in Europe, Asia, and the USA is provided, the sensitivity of various taxa is presented through a comparison of the lowest EC50s from about a hundred acute toxicity tests, and primary mechanisms of FQ toxicity are described. A risk assessment is conducted based on the estimation of the Predicted No Effect Concentration (PNEC). This is calculated traditionally and, in a more contemporary manner, by constructing a normalized Species Sensitivity Distribution curve. The lowest individual HC5 (6.52 µg L-1) was obtained for levofloxacin, followed by ciprofloxacin (7.51 µg L-1), sarafloxacin and clinafloxacin (12.23 µg L-1), and ofloxacin (17.12 µg L-1). By comparing the calculated PNEC with detected concentrations, it is evident that the risk cannot be denied: the potential impact of FQs on freshwater ecosystems is a further reason to minimize their use.

Ecotoxicity of the fluoroquinolone antibiotic delafloxacin to the water flea Simocephalus vetulus and its offspring under the influence of calcium modulation

Delafloxacin (DFX), one of the latest additions to the fluoroquinolone antibiotics, is gaining heightened recognition in human therapy due to its potential antibacterial efficacy in a wide range of applications. Concerns have arisen regarding its presence in the environment and its potential interactions with multivalent metals, such as calcium (Ca). The present study investigated the trans- and multigenerational effects of environmentally projected concentrations of DFX (100-400 μg DFX L-1) on individual- and population-level responses of parental S. vetulus (F0) and its descendants (F1) under normal (26 mg L-1) and high (78 mg L-1) Ca conditions. Exposure of the F0 generation to DFX under the normal Ca condition resulted in reduced juvenile body length (JBL), increased age-specific survival rate (lx), indicating prolonged developmental time, reduced age-specific fecundity rate (mx), and decreased population growth rate (rm). Under the high Ca condition, JBL, mx, and rm were adversely affected. Transgenerational effects of DFX existed, as F1 individuals exhibited persistent suppressions in at least one endpoint under both Ca conditions even after being transferred to a clear medium. Continuous exposure of the F1 generation to DFX had negative impacts on JBL, mx, and rm under the normal Ca condition, and on JBL and rm under the high Ca condition. However, cumulative effects were not observed, suggesting the potential development of tolerance to DFX in the F1 organisms. These findings suggest that DFX is a harmful compound for the non-target model organism S. vetulus and reveal a potential antagonism between DFX and Ca. Nevertheless, the interaction between other (fluoro)quinolones and Ca remains unclear, necessitating further research to establish this phenomenon more comprehensively, including understanding the interaction mechanism in ecotoxicological contexts.

A group-targeting biosensor for sensitive and rapid detection of quinolones in water samples

BACKGROUND

Quinolones (QNs) widely exist in the environment due to their wide range of applications and poor metabolic properties, resulting in the generation and spread of resistance genes, posing a potential threat to human health. Traditional analytical methods cannot detect all broad ranges of QNs simultaneously. The development of facile, efficient and reliable method for quantification and assessment of the total QNs is a long-lasting challenge.

RESULTS

We hereby provide a simple, sensitive and instantaneous group-targeting biosensor for the detection of total QNs in environmental water samples. The biosensor is based on a group-specific antibodies with high affinity against QNs. Fluorescent labeled antibodies bound to the coated antigen modified on the surface of the transducer, and excited by the evanescent waves. The detected fluorescent signal is inversely proportional to the QNs concentration. This biosensor exhibited excellent performance with detection limits lower than 0.15 μg L-1 for all five QNs variants, and even lower than 0.075 μg L-1 for ciprofloxacin (CIP) and ofloxacin (OFL). Environmental water samples can be detected after simple pretreatment, and all detection steps can be completed in 10 min. The transducer has a high regenerative capacity and shows no significant signal degradation after two hundred detection cycles. The recoveries of QNs in a variety of wastewater range from 105 to 119%, confirming its application potential in the measurement of total QNs in reality.

SIGNIFICANCE

The biosensor can realize rapid and sensitive detection of total QNs in water samples by simple pretreatment, which overcomes the disadvantage of the traditional methods that require complex pretreatment and time-consuming, and pave the groundwork for expansive development centered around this technology.

The number of test organisms might influence the toxicity evaluation of hydrophobic micropollutants

Evaluating the toxicity of micropollutants forms the basis for understanding their potential risks to the ecosystem and/or human health. To accurately evaluate the toxicity of micropollutants in toxicity tests, many factors have been carefully considered, while the impact of the number of test organisms on toxicity results has rarely been taken into account. In this study, the role of the organism number on the developmental toxicity of five micropollutants was investigated using embryos of the marine polychaete Platynereis dumerilii. The toxicity of hydrophobic micropollutants was found to decrease significantly with increasing the number of embryos used in the test. A quantitative model was developed to better describe how the number of embryos affected developmental toxicity. The model showed a satisfactory fit to the raw data in all scenarios tested. The intrinsic half-maximal effective concentration EC50,int was then determined using the model. For a given compound, the EC50,int was a stable parameter that did not depend on the number of test embryos and thus provided an indication of the intrinsic toxicity of the compounds tested. Compared with the EC50 values determined with the commonly used embryo number (around 120), the EC50,int values of all tested hydrophobic micropollutants were lower. The more hydrophobic the compounds tested, the more pronounced the reduction in toxicity. This suggested that hydrophobic micropollutants could be more toxic than reported in the literature. Some suggestions were also made to eliminate the effect of the number of organisms used in the toxicity evaluation.

Antibiotic occurrence, environmental risks, and their removal from aquatic environments using microalgae: Advances and future perspectives

Antibiotic pollution has caused a continuous increase in the development of antibiotic-resistant bacteria and antibiotic-resistant genes (ARGs) in aquatic environments worldwide. Algae-based bioremediation technology is a promising eco-friendly means to remove antibiotics and highly resistant ARGs, and the generated biomass can be utilized to produce value-added products of industrial significance. This review discussed the prevalence of antibiotics and ARGs in aquatic environments and their environmental risks to non-target organisms. The potential of various microalgal species for antibiotic and ARG removal, their mechanisms, strategies for enhanced removal, and future directions were reviewed. Antibiotics can be degraded into non-toxic compounds in microalgal cells through the action of extracellular polymeric substances, glutathione-S-transferase, and cytochrome P450; however, antibiotic stress can alter microalgal gene expression and growth. This review also deciphered the effect of antibiotic stress on microalgal physiology, biomass production, and biochemical composition that can impact their commercial applications.

Occurrence, Bioaccumulation, Metabolism and Ecotoxicity of Fluoroquinolones in the Aquatic Environment: A Review

In recent years, there has been growing concern about antibiotic contamination in water bodies, particularly the widespread presence of fluoroquinolones (FQs), which pose a serious threat to ecosystems due to their extensive use and the phenomenon of "pseudo-persistence". This article provides a comprehensive review of the literature on FQs in water bodies, summarizing and analyzing contamination levels of FQs in global surface water over the past three years, as well as the bioaccumulation and metabolism patterns of FQs in aquatic organisms, their ecological toxicity, and the influencing factors. The results show that FQs contamination is widespread in surface water across the surveyed 32 countries, with ciprofloxacin and norfloxacin being the most heavy contaminants. Furthermore, contamination levels are generally higher in developing and developed countries. It has been observed that compound types, species, and environmental factors influence the bioaccumulation, metabolism, and toxicity of FQs in aquatic organisms. FQs tend to accumulate more in organisms with higher lipid content, and toxicity experiments have shown that FQs exhibit the highest toxicity to bacteria and the weakest toxicity to mollusk. This article summarizes and analyzes the current research status and shortcomings of FQs, providing guidance and theoretical support for future research directions.

Veterinary pharmaceutical as emerging contaminants in wastewater and surface water: An overview

Veterinary pharmaceuticals have become of interest due to their indiscriminate use. Thus, this paper compiles studies on detection in surface and wastewater, and the treatment applied for their removal. Additionally, a case study was performed to evaluate its commercialization, as the ecological risk assessment for the most relevant compounds. 241 compounds were detected. The highest concentrations were found for antibiotics such as oxytetracycline, amoxicillin, and monensin, with values up to 3732.4 µg/L. Biological treatments have been mainly reported, obtaining removal greater than 80% for sulfadiazine, sulfamethazine, sulfamethoxazole, enrofloxacin, and oxytetracycline. Considering the case study, enrofloxacin and oxytetracycline were widely commercialized. Finally, there was a low risk for the species exposed to enrofloxacin, in contrast, the species exposed to oxytetracycline presented a high risk of long-term mortality. Concluding that veterinary compounds have emerged as a significant concern regarding water source contamination, owing to their potential adverse effects on aquatic biota and even human. This is particularly relevant because many water bodies that receive wastewater are utilized for drinking water purposes. Consequently, the development of comprehensive, full-scale systems for efficient antibiotic removal before their introduction into water sources becomes imperative. Equally important is the need to reconsider their extensive use altogether.

A comprehensive and global evaluation of residual antibiotics in agricultural soils: Accumulation, potential ecological risks, and attenuation strategies

The occurrence of antibiotics in agricultural soils has raised concerns due to their potential risks to ecosystems and human health. However, a comprehensive understanding of antibiotic accumulation, distribution, and potential risks to terrestrial ecosystems on a global scale is still limited. Therefore, in this study, we evaluated the accumulation of antibiotics and their potential risks to soil microorganisms and plants, and highlighted the driving factors of antibiotic accumulation in agricultural soils based on 134 peer-reviewed studies (between 2000 and 2022). The results indicated that 56 types of antibiotics were detected at least once in agricultural soils with concentrations ranging from undetectable to over 7000 µg/kg. Doxycycline, tylosin, sulfamethoxazole, and enrofloxacin, belonging to the tetracyclines, macrolides, sulfonamides, and fluoroquinolones, respectively, were the most accumulated antibiotics in agricultural soil. The accumulation of TCs, SAs, and FQs was found to pose greater risks to soil microorganisms (average at 29.3%, 15.4%, and 21.8%) and plants (42.4%, 26.0%, and 38.7%) than other antibiotics. East China was identified as a hot spot for antibiotic contamination due to high levels of antibiotic concentration and ecological risk to soil microorganisms and plants. Antibiotic accumulation was found to be higher in vegetable fields (245.5 µg/kg) and orchards (212.4 µg/kg) compared to croplands (137.2 µg/kg). Furthermore, direct land application of manure resulted in a greater accumulation of TCs, SAs, and FQs accumulation in soils than compost fertilization. The level of antibiotics decreased with increasing soil pH and organic matter content, attributed to decreasing adsorption and enhancing degradation of antibiotics. In conclusion, this study highlights the need for further research on the impacts of antibiotics on soil ecological function in agricultural fields and their interaction mechanisms. Additionally, a whole-chain approach, consisting of antibiotic consumption reduction, manure management strategies, and remediation technology for soil contaminated with antibiotics, is needed to eliminate the potential environmental risks of antibiotics for sustainable and green agriculture.

Magnetically separable laccase-biochar composite enable highly efficient adsorption-degradation of quinolone antibiotics: Immobilization, removal performance and mechanisms

The tremendous potential of hybrid technologies for the elimination of quinolone antibiotics has recently attracted considerable attention. This current work prepared a magnetically modified biochar (MBC) immobilized laccase product named LC-MBC through response surface methodology (RSM), and LC-MBC showed an excellent capacity in the removal of norfloxacin (NOR), enrofloxacin (ENR) and moxifloxacin (MFX) from aqueous solution. The superior pH, thermal, storage and operational stability demonstrated by LC-MBC revealed its potential for sustainable application. The removal efficiencies of LC-MBC in the presence of 1 mM 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) for NOR, ENR and MFX were 93.7 %, 65.4 % and 77.0 % at pH 4 and 40 °C after 48 h reaction, respectively, which were 1.2, 1.3 and 1.3 times higher than those of MBC under the same conditions. The synergistic effect of adsorption by MBC and degradation by laccase dominated the removal of quinolone antibiotics by LC-MBC. Pore-filling, electrostatic, hydrophobic, π-π interactions, surface complexation and hydrogen bonding contributed in the adsorption process. The attacks on the quinolone core and piperazine moiety were involved in the degradation process. This study underscored the possibility of immobilization of laccase on biochar for enhanced remediation of quinolone antibiotics-contaminated wastewater. The proposed physical adsorption-biodegradation system (LC-MBC-ABTS) provided a novel perspective for the efficient and sustainable removal of antibiotics in actual wastewater through combined multi-methods.

Biochar composite derived from cellulase hydrolysis apple branch for quinolone antibiotics enhanced removal: Precursor pyrolysis performance, functional group introduction and adsorption mechanisms

In this study, magnetic biochar (MAB) and humic acid (HA)-coated magnetic biochar produced from apple branches without and after cellulase hydrolysis (HMAB and CHMAB, respectively) were prepared and tested as adsorbents of enrofloxacin (ENR) and moxifloxacin (MFX) in aqueous solution. Compared with MAB and HMAB, novel adsorbent CHMAB possessed a superior mesoporous structure, greater graphitization degree and abundant functional groups. When antibiotic solutions ranged from 2 to 20 mg L^-1, the theoretical maximum adsorption capacities of CHMAB for ENR and MFX were 48.3 and 61.5 mg g^-1 at 35 °C with adsorbent dosage of 0.4 g L^-1, respectively, while those of MAB and HMAB were 39.6 and 54.4 mg g^-1, and 44.7 and 59.0 mg g^-1, respectively. The pseudo-second-order kinetic model and Langmuir model presented a better fitting to the spontaneous and endothermic adsorption process. The maximum adsorption capacity of ENR and MFX onto CHMAB was achieved at initial pH values of 5 and 8, respectively. Additionally, the adsorption capacity of ENR and MFX decreased with increasing concentrations of K⁺ and Ca²⁺ (0.02-0.1 mol L^-1). Synergism between the pore-filling effect, π-π electron-donor-acceptor interactions, regular and negative charge-assisted H-bonding, surface complexation, electrostatic interactions and hydrophobic interactions may dominate the adsorption process. This study demonstrated that a novel magnetic biochar composite prepared through pyrolysis of agricultural waste lignocellulose hydrolyzed by cellulase in combination with HA coating was a promising adsorbent for eliminating quinolone antibiotics from aqueous media.

Impact of Antibiotics as Waste, Physical, Chemical, and Enzymatical Degradation: Use of Laccases

The first traces of Tetracycline (TE) were detected in human skeletons from Sudan and Egypt, finding that it may be related to the diet of the time, the use of some dyes, and the use of soils loaded with microorganisms, such as Streptomyces spp., among other microorganisms capable of producing antibiotics. However, most people only recognise authors dating between 1904 and 1940, such as Ehrlich, Domagk, and Fleming. Antibiotics are the therapeutic option for countless infections treatment; unfortunately, they are the second most common group of drugs in wastewaters worldwide due to failures in industrial waste treatments (pharmaceutics, hospitals, senior residences) and their irrational use in humans and animals. The main antibiotics problem lies in delivered and non-prescribed human use, use in livestock as growth promoters, and crop cultivation as biocides (regulated activities that have not complied in some places). This practice has led to the toxicity of the environment as antibiotics generate eutrophication, water pollution, nutrient imbalance, and press antibiotic resistance. In addition, the removal of antibiotics is not a required process in global wastewater treatment standards. This review aims to raise awareness of the negative impact of antibiotics as residues and physical, chemical, and biological treatments for their degradation. We discuss the high cost of physical and chemical treatments, the risk of using chemicals that worsen the situation, and the fact that each antibiotic class can be transformed differently with each of these treatments and generate new compounds that could be more toxic than the original ones; also, we discuss the use of enzymes for antibiotic degradation, with emphasis on laccases.

Instantaneous synthesis and full characterization of organic-inorganic laccase-cobalt phosphate hybrid nanoflowers

A novel approach termed the "concentrated method" was developed for the instant fabrication of laccase@Co₃(PO₄)₂•hybrid nanoflowers (HNFs). The constructed HNFs were obtained by optimizing the concentration of cobalt chloride and phosphate buffer to reach the highest activity recovery. The incorporation of 30 mM CoCl₂ and 160 mM phosphate buffer (pH 7.4) resulted in a fast anisotropic growth of the nanomaterials. The purposed method did not involve harsh conditions and prolonged incubation of precursors, as the most reported approaches for the synthesis of HNFs. The catalytic efficiency of the immobilized and free laccase was 460 and 400 M⁻¹S⁻¹, respectively. Also, the enzymatic activity of the prepared biocatalyst was 113% of the free enzyme (0.5 U mL⁻¹). The stability of the synthesized HNFs was enhanced by 400% at pH 6.5–9.5 and the elevated temperatures. The activity of laccase@Co₃(PO₄)₂•HNFs declined to 50% of the initial value after 10 reusability cycles, indicating successful immobilization of the enzyme. Structural studies revealed a 32% increase in the α-helix content after hybridization with cobalt phosphate, which improved the activity and stability of the immobilized laccase. Furthermore, the fabricated HNFs exhibited a considerable ability to remove moxifloxacin as an emerging pollutant. The antibiotic (10 mg L⁻¹) was removed by 24% and 75% after 24 h through adsorption and biodegradation, respectively. This study introduces a new method for synthesizing HNFs, which could be used for the fabrication of efficient biocatalysts, biosensors, and adsorbents for industrial, biomedical, and environmental applications.

Automated Counting of Daphnid Neonates, Artemia Nauplii, and Zebrafish Eggs: A Proof of Concept

In aquatic invertebrate (e.g., daphnids and Artemia sp.) and zebrafish cultures, in ecotoxicological bioassays, or when addressing complex population-level experimental designs, the counting of an organism's progeny is often required. This counting process is laborious, repetitive, and time-consuming, potentially posing health hazards to the operators, and necessarily entailing a higher likelihood of human error. We present an experimental evaluation of a computer-based device for counting neonates (Daphnia magna, Daphnia longispina, and Ceriodaphnia sp.), nauplii (Artemia salina and Artemia franciscana), and zebrafish (Danio rerio) eggs. Manual counts by an experienced technician were compared with the corresponding automated counts achieved by the computer-based counting device. A minimum of 55 counts/species was performed, with the number of counted organisms being up to a maximum of 150 neonates of Ceriodaphnia dubia, 200 neonates of D. magna and D. longispina, 200 nauplii of A. franciscana and A. salina, and 500 zebrafish eggs. Manual and automated counts were both performed in culture medium solutions of 50 ml of volume. Automated counts showed a mean relative acccuracy of 98.9% (97.9%-99.4%) and a relative standard deviation of 1.72%. The results demonstrate that the computer-based device can be used for accurately counting these aquatic organisms. This computer-based counting might be extended to other organisms of similar size, thus facilitating reproduction and life-cycle ecotoxicity tests. Environ Toxicol Chem 2022;41:1451-1458. © 2022 SETAC.

Lattice B-doping evolved ferromagnetic perovskite-like catalyst for enhancing persulfate-based degradation of norfloxacin

Series of B-doped perovskite-like materials CeCu_0.5Co_0.5O₃ (B-C³O) were fabricated with unique ferromagnetic property due to partial substitution of non-magnetic 2p-impurities boron in the lattice. Then, B-C³O was used for activating peroxymonosulfate (PMS) for the degradation of norfloxacin (NOR), one kind of emerging pollutants with the concentration level up to mg/L in wastewaters. The results indicated that 5.0% B-C³O exhibited stable catalytic ability at pH 3.0-9.0 and high degradation efficiency in co-existing inorganic Cl^-, SO₄^2-, NO₃^-, H₂PO₄^- and organic humic acid. Non-radical ¹O₂, radicals •OH and SO₄^•-, as well as ClO^- were detected with synergy effect for NOR degradation. By quantifying free radicals, •OH with 0.52 µM and SO₄^•- with 10.91 µM were obtained at 180 min, verifying the leading role of SO₄^•-. The degradation process involved the defluorination and decarboxylation, as well as opening of quinolone and piperazinyl rings. Adopting alfalfa as the model plant, the toxicity effect before and after NOR degradation was finally evaluated with seed germination rate and chlorophyll content as the physiological indicators. In summary, non-metal B-doping not only provides a creative strategy for the development of ferromagnetic perovskite-like materials, but also affords excellent catalysts for aiding the advanced oxidation technology for removal of emerging pollutants in wastewaters.

Interactive effects of micro/nanoplastics and nanomaterials/pharmaceuticals: Their ecotoxicological consequences in the aquatic systems

Micro/nanoplastics are ubiquitous in the environment and cause pollution of the aquatic ecosystem, in particular, which is a serious concern worldwide. Micro/nanoplastics can act as a vector for multiple co-contaminants that co-exist in the aquatic environment. Apart from micro/nanoplastics, nanomaterials and pharmaceuticals are other emerging contaminants that can also raise severe problems. Thus, in this review, the physicochemical interactions occurring between micro/nanoplastics and nanomaterials and pharmaceuticals and the factors (chemical and environmental) affecting the sorption efficiency of nanomaterials and pharmaceuticals have been addressed. Furthermore, the influence of micro/nanoplastics on the bioavailability and toxic effects of nanomaterials and pharmaceuticals on both freshwater and marine species has been highlighted. Additional focus has also been given to study the mechanism of toxicity of the micro/nanoplastics-nanomaterials and pharmaceuticals complex on the different species of different trophic levels. Finally, this review addresses the knowledge gaps and provides insights into the future research strategies to better understand the interactive mechanisms between the binary contaminants and also the toxicity mechanisms of micro/nanoplastics and nanomaterials and pharmaceuticals.