Crop irrigation (soybean, bean, and corn) with enrofloxacin-contaminated water leads to yield reductions and antibiotic accumulation

Unveiling antibiotic contamination in surface water: A study of the Huaihe River Basin's Huaibei Plain, a significant Chinese herbal medicine planting region

The abuse of antibiotics has caused the accumulation of antibiotic residues in environmental media, threatening the ecosystem and human health. Many studies on the distribution of aqueous antibiotics have been reported. However, the pollution status of antibiotics in the environment in Chinese herbal medicine planting areas is rarely comprehensively clarified, resulting in the lack of updated pollution data and conducive suggestions for ecological cultivation and sustainable development of Chinese herbal medicine. Thus, we comprehensively investigated the distribution, profiles, sources, and risks of the antibiotics in the surface water of an important tributary of the Huaihe River Basin, located in Bozhou City, a significant Chinese herbal medicine planting region. Solid-phase extraction coupled with an ultra-performance liquid chromatography-tandem mass spectrometer (SPE-UPLC-MS) was utilized to detect the antibiotics in the water. 27 kinds of antibiotics were identified with total concentrations ranging from 75.01 to 1737.99 ng·L-1, with doxycycline (DC) and doxycycline hydrochloride (DCH) possessed the highest concentration. And DC, DCH, oxilinic acid (OA), sulfamethoxazole (SMZ), clarithromycin (CLA), and roxithromycinum (ROX) were the main antibiotics detected in this basin. Correlation analysis and principal component analysis (PCA) indicated that animal husbandry was the primary source of antibiotics. Furthermore, the ecological risk assessment revealed that certain antibiotics could seriously threaten the survival of aquatic organisms, implying that local Chinese herbal medicines might be at similar growth risk. The drinking risk assessment showed that antibiotics in the water posed low risks for human, and children faced a greater drinking risk than adults. The study can help to facilitate the management of aqueous antibiotic pollution for the ecological cultivation and safe production of Chinese herbal medicine.

Efficiency of phytoremediation and identification of biotransformation pathways of fluoroquinolones in the aquatic environment

Phytoremediation is a low-cost and sustainable green technology that uses plants to remove organic and inorganic pollutants from aquatic environments. The aim of this study was to investigate the phytoextraction, phytoaccumulation, and phytotransformation of three fluoroquinolones (FQs) (ciprofloxacin [CIP], enrofloxacin [ENF], and levofloxacin [LVF]) by Japanese radish (Raphanus sativus var. longipinnatus) and duckweed (Lemma minor). Determination of FQs and identification of their transformation products (TPs) were performed using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). Inter-tissue translocation of FQs in Japanese radish tissues depended on their initial concentration in the medium. CIP (IT = 14.4) and ENF (IT = 17.0) accumulated mainly in radish roots, while LVF in leaves (IT = 230.8) at an initial concentration of 10 µg g-1. CIP (2,104 ng g-1) was detected in the highest concentration, followed by ENF (426.3 ng g-1) and LVF (273.3 ng g-1) in the tissues of both plants. FQs' bioaccumulation factors were significantly higher for duckweed (1.490-18.240) than Japanese radish (0.027-0.103). The removal of FQs from water using duckweed was mainly due to their photolysis and hydrolysis than plant sorption. In the screening, analysis detected 29 FQ TPs. The biotransformation pathways of FQs are described in detail, and the factors that influence their formation are indicated.

Interconnected environmental challenges: heavy metal-drug interactions and their impacts on ecosystems

Industrial expansion and inadequate environmental safety measures are major contributors to environmental contamination, with heavy metals (HMs) and pharmaceutical waste playing crucial roles. Their negative effects are most noticeable in aquatic species and vegetation, where they accumulate in tissues and cause harmful results. Interactions between HMs and pharmaceutical molecules result in the production of metal-drug complexes (MDCs), which have the potential to disturb diverse ecosystems and their interdependence. However, present studies frequently focus on individual pollutants and their effects on specific environmental parameters, leaving out the cumulative effects of pollutants and their processes across several environmental domains. To address this gap, this review emphasizes the environmental sources of HMs, elucidates their emission pathways during anthropogenic activities, investigates the interactions between HMs and pharmaceutical substances, and defines the mechanisms underlying the formation of MDCs across various ecosystems. Furthermore, this review underscores the simultaneous occurrence of HMs and pharmaceutical waste across diverse ecosystems, including the atmosphere, soil, and water resources, and their incorporation into biotic organisms across trophic levels. It is important to note that these complex compounds represent a higher risk than individual contaminants.

Molecularly Imprinted Heterostructure-Assisted Laser Desorption Ionization Mass Spectrometry Analysis and Imaging of Quinolones

Quinolone residues resulting from body metabolism and waste discharge pose a significant threat to the ecological environment and to human health. Therefore, it is essential to monitor quinolone residues in the environment. Herein, an efficient and sensitive matrix-assisted laser desorption/ionization mass spectrometry (MALDI/MS) method was devised by using a novel molecularly imprinted heterojunction (MIP-TNs@GCNs) as the matrix. Molecularly imprinted titanium dioxide nanosheets (MIP-TNs) and graphene-like carbon nitrides (GCNs) were associated at the heterojunction interface, allowing for the specific, rapid, and high-throughput ionization of quinolones. The mechanism of MIP-TNs@GCNs was clarified using their adsorption properties and laser desorption/ionization capability. The prepared oxygen-vacancy-rich MIP-TNs@GCNs heterojunction exhibited higher light absorption and ionization efficiencies than TNs and GCNs. The good linearity (in the quinolone concentration range of 0.5-50 pg/μL, R2 > 0.99), low limit of detection (0.1 pg/μL), good reproducibility (n = 8, relative standard deviation [RSD] < 15%), and high salt and protein resistance for quinolones in groundwater samples were achieved using the established MIP-TNs@GCNs-MALDI/MS method. Moreover, the spatial distributions of endogenous compounds (e.g., amino acids, organic acids, and flavonoids) and xenobiotic quinolones from Rhizoma Phragmitis and Rhizoma Nelumbinis were visualized using the MIP-TNs@GCNs film as the MALDI/MS imaging matrix. Because of its superior advantages, the MIP-TNs@GCNs-MALDI/MS method is promising for the analysis and imaging of quinolones and small molecules.

Urban agglomerations as an environmental dimension of antibiotics transmission through the "One Health" lens

The spatiotemporal distributions of antibiotics in different media have been widely reported; however, their occurrence in the environmental dimension of the Chinese urban agglomerations has received less attention, especially in bioaccumulation and health risks of antibiotics through the "One Health" lens. The review presents the current knowledge on the environmental occurrence, bioaccumulation, as well as health exposure risks in urban agglomerations through the "One Health" lens, and identifies current information gaps. The reviewed studies suggested antibiotic concentrations in water and soil were more sensitive to social indicators of urban agglomerations than those in sediment. The ecological risk and resistance risk of antibiotics in water were much higher than those of sediments, and the high-risk phenomenon occurred at a higher frequency in urban agglomerations. Erythromycin-H2O (ETM-H2O), amoxicillin (AMOX) and norfloxacin (NFC) were priority-controlled antibiotics in urban waters. Tetracyclines (TCs) posed medium to high risks to soil organisms in the soil of urban agglomerations. Health risk evaluation based on dietary intake showed that children had the highest dietary intake of antibiotics in urban agglomerations. The health risk of antibiotics was higher in children than in other age groups. Our results also demonstrated that dietary structure might impact health risks associated with target antibiotics in urban agglomerations to some extent.

The enrofloxacin pollution control from fish to environment

Enrofloxacin (ENR) is used to prevent and treat fish diseases widely. However, its pollution is increasing public concern on human health and aquatic ecosystem safety. This review aims to find its pollution mechanisms and control way. It is found: (1) The excessive ENR administration is the main source, the sediment ENR escaping from photolysis is the secondary ENR pollution source; (2) The ENR-rich fishes were benthic lipid-rich fishes which can simultaneously absorb administration ENR and sediment ENR, the ENR bioaccumulation is positively related to the fish habitats ENR level and fish lipids content; (3) The ENR t1/2 varies with fish age, body weight, feedstuff lipids and crude fiber level, temperature, salinity, administration mode and dose; Consequently, the first control way is to conduct the minimum inhibitory concentration ENR, combining herbal medicines with antibacterial and detoxification functions. The second way is to develop the enrichment and removal techniques for sediment ENR.

Tetracycline inhibits the nitrogen fixation ability of soybean (Glycine max (L.) Merr.) nodules in black soil by altering the root and rhizosphere bacterial communities

Tetracycline is a widely used antibiotic and may thus also be an environmental contaminant with an influence on plant growth. The aim of this study was to investigate the inhibition mechanisms of tetracycline in relation to soybean growth and ecological networks in the roots and rhizosphere. To this end, we conducted a pot experiment in which soybean seedlings were grown in soil treated with 0, 10, or 25 mg/kg tetracycline. The effects of tetracycline pollution on growth, productivity, oxidative stress, and nitrogenase activity were evaluated. We further identified the changes in microbial taxa composition and structure at the genus and species levels by sequencing the 16S rRNA gene region. The results showed that tetracycline activates the antioxidant defense system in soybeans, which reduces the abundance of Bradyrhizobiaceae, inhibits the nitrogen-fixing ability, and decreases the nitrogen content in the root system. Tetracycline was also found to suppress the formation of the rhizospheric environment and decrease the complexity and stability of bacterial networks. Beta diversity analysis showed that the community structure of the root was markedly changed by the addition of tetracycline, which predominantly affected stochastic processes. These findings demonstrate that the influence of tetracycline on soybean roots could be attributed to the decreased stability of the bacterial community structure, which limits the number of rhizobium nodules and inhibits the nitrogen-fixing capacity. This exploration of the inhibitory mechanisms of tetracycline in relation to soybean root development emphasises the potential risks of tetracycline pollution to plant growth in an agricultural setting. Furthermore, this study provides a theoretical foundation from which to improve our understanding of the physiological toxicity of antibiotics in farmland.

Occurrence of antibiotics in reclaimed water, and their uptake dynamics, phytotoxicity, and metabolic fate in Lolium perenne L

Reclaimed water (RW) has been extensively used for irrigation in agriculture, yet the occurrence of antibiotics in real RW, and their toxicity, uptake dynamics and metabolic fate still needs comprehensive exploration. In this study, we investigated the residual concentrations of nineteen antibiotics in the RW from four wastewater treatment plants, and determined their toxicity on plant at environment-relevant concentration. Total found concentrations of these antibiotics ranged from 623.66 ng L-1 to 1536.96 ng L-1, which decreased 10.3 and 19.4 % of roots' length and weight. Uptake dynamics analysis of the most hazardous antibiotic, norfloxacin (NFX) showed increasing amounts in the roots and leaves up to 3087.71 μg g-1. Ryegrass also can remove >80 % of 100 μg L-1 NFX being achieved by biodegradation through ring cleavage, decarboxylation, defluorination, hydrogenation, methylation and oxidation. Toxicity assessment of the identified byproducts showed their more toxic effect on fish, daphnia and algae. This study extended our understanding of the fate of antibiotics in plants during irrigation with reclaimed water, and emphasized its safety and pollutants' biomagnification concerns.

Degradation of enrofloxacin by a novel Fe-N-C@ZnO material in freshwater and seawater: Performance and mechanism

In this study, we investigated the doping of Fe-N-C with ZnO (Fe-N-C@ZnO) to enhance its performance in the reduction of biological toxicity and degradation of enrofloxacin (ENR) in seawater. The steady-state/transient fluorescence analysis and free radical quenching test indicated an extremely low electron-hole recombination rate and the generation of reactive oxygen species in Fe-N-C@ZnO, leading to an improvement in the energy efficiency. We compared the ENR degradation efficiencies of Fe-N-C@ZnO and ZnO using both freshwater and seawater. In freshwater, Fe-N-C@ZnO exhibited a slightly higher degradation efficiency (95.00%) than ZnO (90.30%). However, the performance of Fe-N-C@ZnO was significantly improved in seawater compared to that of ZnO. The ENR degradation efficiency of Fe-N-C@ZnO (58.87%) in seawater was 68.39% higher than that of ZnO (34.96%). Furthermore, the reaction rate constant for ENR degradation by Fe-N-C@ZnO in seawater (7.31 × 10-3 min-1) was more than twice that of ZnO (3.58 × 10-3 min-1). Response surface analysis showed that the optimal reaction conditions were a pH of 7.42, a photocatalyst amount of 1.26 g L-1, and an initial ENR concentration of 6.56 mg L-1. Fe-N-C@ZnO prepared at a hydrothermal temperature of 128 °C and heating temperature of 300 °C exhibited the optimal performance for the photocatalytic degradation of ENR. Based on liquid chromatography-mass spectrometry analysis, the degradation processes of ENR were proposed as three pathways: two piperazine routes and one quinolone route.

Four antibiotics and copper interactive effects on the growth and physiological characteristics of Hydrilla verticillata (L.f.) Royle

Co-pollution of antibiotics and heavy metal copper (Cu) is common in freshwater environments because of their wide use as antimicrobial agents, especially in aquaculture. However, the toxic effects of coexisting antibiotics and heavy metals on aquatic plants remain unclear. This study investigated the effect of four antibiotics (i.e., enrofloxacin, ENR; tetracycline, TC; sulfamethoxazole, SMX; erythromycin, ERY), Cu, and their mixture on the growth and physiological responses of Hydrilla verticillata (L.f.) Royle. Results showed that the four antibiotics exhibited toxic effects on the growth and physiological indicators of H. verticillata, and root elongation was the most sensitive endpoint of the phytotoxicity test. The median effect concentration (EC50) of root elongation indicated that TC (EC50 = 10.05 mg/L) has the highest level of growth toxicity, and the toxicity of ENR to aquatic plants was close to TC (EC50 = 10.44 mg/L), followed by SMX (EC50 = 20.08 mg/L). However, there was no significant toxic effect of 20 mg/L ERY on the root elongation. Hydrophobicity may be a key factor affecting the phytotoxicity of antibiotics. Moreover, antagonistic toxic effects were observed under ENR + Cu, TC + Cu, SMX + Cu, and ERY + Cu co-exposures at all the experimental concentrations (0.01-20 mg/L). Due to the concentrations of antibiotics in natural waters usually with ng/L levels, our results suggested that environmental antibiotic concentrations probably pose low ecological risk to aquatic plants and indicated the H. verticillata could be used as phytoremediation candidate to remove antibiotic or antibiotic-Cu pollutions in general nature water.

Polystyrene microplastic attenuated the toxic effects of florfenicol on rice (Oryza sativa L.) seedlings in hydroponics: From the perspective of oxidative response, phototoxicity and molecular metabolism

Antibiotics and microplastics (MPs) are two emerging pollutants in agroecosystems, however the effects of co-exposure to antibiotics and MPs remain unclear. The toxicity of florfenicol (FF) and polystyrene microplastics (PS-MPs) on rice seedlings was investigated. FF and PS-MPs caused colloidal agglomeration, which changed the environmental behavior of FF. FF inhibited rice growth and altered antioxidant enzyme (superoxide dismutase, peroxidase, and catalase) activities, leading to membrane lipid peroxidation; impaired photosynthetic systems, decreased photosynthetic pigments (Chlorophyll a, Chlorophyll b, and carotene), chlorophyll precursors (Proto IX, Mg-Proto IX, and Pchlide), photosynthetic and respiratory rates. The key photosynthesis related genes (PsaA, PsaB, PsbA, PsbB, PsbC, and PsbD) were significantly down-regulated. The ultrastructure of mesophyll cells was destroyed with chloroplast swelling, membrane surface blurring, irregular thylakoid lamellar structure, and number of peroxisomes increased. PS-MPs mitigated FF toxicity, and the IBR index values showed that 10 mg∙L-1 PS-MPs were more effective. Metabolomic analysis revealed that the abundance of metabolites and metabolic pathways were altered by FF, was greater than the combined "MPs-FF" contamination. The metabolism of amino acids, sugars, and organic acids were severely interfered. Among these, 15 metabolic pathways were significantly altered, with the most significant effects on phenylalanine metabolism and the citric acid cycle (p < 0.05).

Antenna effect of perylene-sensitized up-conversion luminescent material amplifies the signal of electrochemiluminescence biosensor platform for the ultra-sensitive detection of enrofloxacin

Recently, up-conversion luminescent (UCL) materials have caught extensive sight on account of their excellent biocompatibility and weak automatic fluorescence background, but the low optical signal makes researchers shy away. Organic dye-sensitized UCL materials can improve the low optical signal drawback of UCL and rejuvenate it with adjustable optical properties and unique antenna effects. In this work, an efficient, simple and selective electrochemiluminescence (ECL) sensing platform was developed for determination of enrofloxacin (ENR). 3,4,9,10-perylene tetracarboxylic acid (PTCA) was successfully used as an "antenna" to improve the ECL performance of the UCL nanoparticles (PEI-NaYF4: Yb, Er) due to its appropriate excitation spectrum position and superior electron transfer rate. The specific recognition function of the aptamer enabled the sensor to eliminate the interference from conspecific impurity. In the presence of ENR, the specific combination of ENR with aptamer made the aptamer fall from surface of the electrode, thus we could see a considerable enhancement of signal. Under the most favourable conditions, the aptasensor based on antenna effect displayed a wide detection range (1.0 × 10-14∼1.0 × 10-6 M), low limit of detection (LOD = 3.0 × 10-15 M) and receivable recoveries (96.0%-102.4%) during water samples analysis. At this point, antenna effect provides a powerful strategy to expand the application of UCL in the field of ECL biosensing.

Pharmaceutical-contaminated irrigation water: implications for ornamental plant production and phytoremediation using enrofloxacin-accumulating species

Enrofloxacin (Enro) has been widely encountered in natural water sources, and that water is often used for irrigation in crop production systems. Due to its phytotoxicity and accumulation in plant tissues, the presence of Enro in water used for crop irrigation may represent economical and toxicological concerns. Here, we irrigated two ornamental plant species (Zantedeschia rehmannii Engl. and Spathiphyllum wallisii Regel.) with water artificially contaminated with the antimicrobial enrofloxacin (Enro; 0, 5, 10, 100, and 1000 μg L-1) to evaluate its effects on ornamental plant production, as well as its accumulation and distribution among different plant organs (roots, leaves, bulbs, and flower stems), and examined the economic and environmental safety of commercializing plants produced under conditions of pharmaceutical contamination. The presence of Enro in irrigation water was not found to disrupt plant growth (biomass) or flower production. Both species accumulated Enro, with its internal concentrations distributed as the following: roots > leaves > bulbs > flower stems. In addition to plant tolerance, the content of Enro in plant organs indicated that both Z. rehmannii and S. wallisii could be safety produced under Enro-contaminated conditions and would not significantly contribute to contaminant transfer. The high capacity of those plants to accumulate Enro in their tissues, associated with their tolerance to it, indicates them for use in Enro-phytoremediation programs.

Antibiotics induced changes in nitrogen metabolism and antioxidative enzymes in mung bean (Vigna radiata)

Excessive use and release of antibiotics into the soil environment in the developing world have resulted in altered soil processes affecting terrestrial organisms and posing a serious threat to crop growth and productivity. The present study investigated the influence of exogenously applied oxytetracycline (OXY) and levofloxacin (LEV) on plant physiological responses, key enzymes involved in nitrogen metabolism (e.g., nitrate reductase, glutamine synthetase), nitrogen contents and oxidative stress response of mung bean (Vigna radiata). Plants were irrigated weekly with antibiotics containing water for exposing the plants to different concentrations i.e., 1, 10, 20, 50, and 100 mg L^-1. Results showed a significant decrease in nitrate reductase activity in both antibiotic treatments and their mixtures and increased antioxidant enzymatic activities in plants. At lower concentrations of antibiotics (≤20 mg L^-1), 53.9 % to 78.4 % increase in nitrogen content was observed in levofloxacin and mixtures compared to the control, resulting in an increase in the overall plant biomass. Higher antibiotic (≥50 mg L^-1) concentration showed 58 % decrease in plant biomass content and an overall decrease in plant nitrogen content upon exposure to the mixtures. This was further complemented by 22 % to 42 % increase in glutamine synthetase activity observed in the plants treated with levofloxacin and mixtures. The application of low doses of antibiotics throughout the experiments resulted in lower toxicity symptoms in the plants. However, significantly higher malondialdehyde (MDA) concentrations at higher doses (20 mg L^-1 and above) than the control showed that plants' tolerance against oxidative stress was conceded with increasing antibiotic concentrations. The toxicity trend was: levofloxacin > mixture > oxytetracycline.

Antimicrobial and the Resistances in the Environment: Ecological and Health Risks, Influencing Factors, and Mitigation Strategies

Antimicrobial contamination and antimicrobial resistance have become global environmental and health problems. A large number of antimicrobials are used in medical and animal husbandry, leading to the continuous release of residual antimicrobials into the environment. It not only causes ecological harm, but also promotes the occurrence and spread of antimicrobial resistance. The role of environmental factors in antimicrobial contamination and the spread of antimicrobial resistance is often overlooked. There are a large number of antimicrobial-resistant bacteria and antimicrobial resistance genes in human beings, which increases the likelihood that pathogenic bacteria acquire resistance, and also adds opportunities for human contact with antimicrobial-resistant pathogens. In this paper, we review the fate of antimicrobials and antimicrobial resistance in the environment, including the occurrence, spread, and impact on ecological and human health. More importantly, this review emphasizes a number of environmental factors that can exacerbate antimicrobial contamination and the spread of antimicrobial resistance. In the future, the timely removal of antimicrobials and antimicrobial resistance genes in the environment will be more effective in alleviating antimicrobial contamination and antimicrobial resistance.

Metabolomics and proteomics reveal the toxicological mechanisms of florfenicol stress on wheat (Triticum aestivum L.) seedlings

Although the ecological impacts of antibiotics have received attention worldwide, research on the toxicity of florfenicol is still limited. We conducted a metabolomic and proteomic study on wheat (Triticum aestivum L.) seedlings to reveal the toxicological mechanism of florfenicol. The growth of the wheat seedlings was found to be inhibited by florfenicol. Antioxidant enzyme activities (superoxide dismutase, peroxidase and catalase), malondialdehyde content and membrane permeability increased with increasing florfenicol concentration. The contents of chlorophyll and chlorophyll synthesis precursor substances (Proto IX, Mg-proto IX and Pchlide), photosynthetic and respiration rates, and chlorophyll fluorescence parameters decreased, indicating that photosynthesis was inhibited. The ultrastructure of chloroplasts was destroyed, as evidenced by the blurred membrane surface, irregular grana arrangement, irregular thylakoid lamella structure, and increased plastoglobuli number. Proteome analysis revealed that up-regulated proteins were highly involved in protein refolding, translation, oxidation-reduction, tricarboxylic acid cycle (TCA cycle), reactive oxygen species metabolic process, cellular oxidant detoxification, and response to oxidative stress. The down-regulated proteins were mainly enriched in photosynthesis-related pathways. In the metabolome analysis, the content of most of the metabolites in wheat leaves, such as carbohydrates and amino acids increased significantly (p < 0.05). Combined pathway analysis showed that florfenicol stress stimulated the TCA cycle pathway and downregulated the photosynthesis pathway.

Salvinia molesta phytoremediation capacity as a nature-based solution to prevent harmful effects and accumulation of ciprofloxacin in Neotropical catfish

Phytoremediation has been a potential solution for the removal of pharmaceuticals from water. Here, we evaluated the toxicological safety of ciprofloxacin-contaminated water treated by 96 h with Salvinia molesta. The Neotropical catfish Rhamdia quelen was used as a model, and the potential of the phytoremediation technique for mitigating the drug accumulation in the fishes was also studied. Fish exposed to Cipro (1 and 10 µg·L^-1) in untreated water showed toxic responses (alteration of hematological, genotoxicity, biochemical, and histopathological biomarkers) and accumulated Cipro in their muscles at concentrations high for human consumption (target hazardous quotient > 1). Fish exposed to water treated with S. molesta showed no toxic effect and no accumulation of Cipro in their tissues. This must be related to the fact that S. molesta removed up to 97% of Cipro from the water. The decrease in Cipro concentrations after water treatment with S. molesta not only prevented the toxic effects of Cipro on R. quelen fish but also prevented the antimicrobial accumulation in fish flesh, favouring safe consumption by humans. For the very first time, we showed the potential of phytoremediation as an efficiently nature-based solution to prevent environmental toxicological effects of antimicrobials to nontarget organisms such as fish and humans. The use of S. molesta for Cipro-removal from water is a green technology to be considered in the combat against antimicrobial resistance.

Accumulation and risk assessment of antibiotics in edible plants grown in contaminated farmlands: A review

The extensive occurrence of antibiotics in farmland soil might threaten food safety. The bioaccumulation potential of antibiotics in edible vegetables and crops grown under realistic farming scenarios was reviewed and the human health risk was assessed. A total of 51 antibiotics were documented in 37 species of daily consumed crops. Among different classes of antibiotics, tetracyclines (TCs) exhibited higher residue levels in plants than quinolones (QNs), sulfonamides (SAs), and macrolides (MLs), with median values ranging from 5.10 to 15.4 μg/kg dry weight. The favored accumulation of TCs in plants was probably linked to their relatively higher residual concentrations in soils and greater bioconcentration factors. Compared with the plants grown in open field, accumulation of antibiotics was higher in plant grown under greenhouse condition, probably due to the higher residue levels of antibiotics in the greenhouse soil with intensive application of manure. Cocktails of antibiotics were investigated in potato, corn, carrot, tomato, lettuce, and wheat. Among them, corn exhibited relatively high median concentrations of antibiotics (0.400-203 μg/kg dry weight). Antibiotics tended to accumulate in plant root and their concentrations in fruit were generally low. Risk assessment revealed that human health risk was under the alert line through the daily consumption of antibiotic contaminated vegetables and food crops.

Combined toxic effects of enrofloxacin and microplastics on submerged plants and epiphytic biofilms in high nitrogen and phosphorus waters

With the wide application of plastic products, microplastic pollution has become a major environmental issue of global concern. Microplastics in aquatic environments can interact with organic pollutants, causing a combined effect on submerged macrophytes. This study investigated the response mechanisms of the submerged plant Myriophyllum verticillatum and epiphytic biofilm to the antibiotic enrofloxacin, microplastics, and their combined exposure in a high nitrogen and phosphorus environment. The results indicated that Myriophyllum verticillatum was not sensitive to enrofloxacin of 1 mg L^-1, while 10 and 50 mg L^-1 enrofloxacin inhibited the uptake of nitrogen and phosphorus by the plants, as well as triggered oxidative stress in the plant leaves, causing irreversible damage to the plant cells. In addition, enrofloxacin altered the structure of the leaf epiphytic biofilm community. Interestingly, 1, 5, and 20 mg L^-1 microplastics had no significant effect on the plant, while they facilitated the aggregation of microorganisms, increasing the abundance of the leaf epiphyte biofilm. The combination of enrofloxacin and microplastics induced a synergistic effect on Myriophyllum verticillatum. Specifically, the rate of nitrogen and phosphorus uptake by the plant was reduced, the content of photosynthetic pigments decreased, and antioxidant enzyme activity was further increased. In addition, the diversity of the leaf epiphytic biofilm community was similar to the single enrofloxacin exposure. These results demonstrated the differences between single and combined exposures and provided a new theoretical basis to evaluate the harmful effects of enrofloxacin and microplastics on submerged macrophytes.

Irrigation Ponds as Sources of Antimicrobial-Resistant Bacteria in Agricultural Areas with Intensive Use of Poultry Litter

Poultry litter is widely used worldwide as an organic fertilizer in agriculture. However, poultry litter may contain high concentrations of antibiotics and/or antimicrobial-resistant bacteria (ARB), which can be mobilized through soil erosion to water bodies, contributing to the spread of antimicrobial resistance genes (ARGs) in the environment. To better comprehend this kind of mobilization, the bacterial communities of four ponds used for irrigation in agricultural and poultry production areas were determined in two periods of the year: at the beginning (low volume of rainfall) and at the end of the rainy season (high volume of rainfall). 16S rRNA gene sequencing revealed not only significantly different bacterial community structures and compositions among the four ponds but also between the samplings. When the DNA obtained from the water samples was PCR amplified using primers for ARGs, those encoding integrases (intI1) and resistance to sulfonamides (sul1 and sul2) and β-lactams (blaGES, blaTEM and blaSHV) were detected in three ponds. Moreover, bacterial strains were isolated from CHROMagar plates supplemented with sulfamethoxazole, ceftriaxone or ciprofloxacin and identified as belonging to clinically important Enterobacteriaceae. The results presented here indicate a potential risk of spreading ARB through water resources in agricultural areas with extensive fertilization with poultry litter.

Do anti-HIV drugs pose a threat to photosynthetic microorganisms?

We investigated the occurrence and risk assessment of three anti-HIV drugs [(tenofovir (TNF), lamivudine (LMV) and efavirenz (EFV)] in urban rivers from Curitiba (Brazil), as well as the individual and combined effects of their environmental representative concentrations on the freshwater periphytic species Synechococcus elongatus (Cyanobacteria) and Chlorococcum infusionum (Chlorophyta). The three studied drugs, except TNF, were found in 100% of the samples, and concentrations in samples ranged from 165 to 412 ng TNF L^-1, 173-874 ng LMV L^-1 and 13-1250 ng EFV L^-1. Bioassays using artificial contaminated water showed that at environmental concentrations, TNF and LMV did not represent environmental risks to the studied photosynthetic organisms. However, EFV was shown to be toxic, affecting photosynthesis, respiration, and oxidative metabolism. The studied drugs demonstrated interactive effects. Indeed, when submitted to the combination of TNF and LMV, decreased photosynthesis was observed in C. infusionum cells. Moreover, the toxic effects of EFV were amplified in both species when TNF and/or LMV were added to the media. The simultaneous presence of TNF, LMV and EFV in environmental matrices associated with their interactive effects, lead to increased toxicological effects of water contaminated by anti-HIV drugs and thus to an ecological threat to photosynthetic microorganisms.

Uptake of Pharmaceutical Pollutants and Their Metabolites from Soil Fertilized with Manure to Parsley Tissues

Manure is a major source of soil and plant contamination with veterinary drugs residues. The aim of this study was to evaluate the uptake of 14 veterinary pharmaceuticals by parsley from soil fertilized with manure. Pharmaceutical content was determined in roots and leaves. Liquid chromatography coupled with tandem mass spectrometry was used for targeted analysis. Screening analysis was performed to identify transformation products in the parsley tissues. A solid-liquid extraction procedure was developed combined with solid-phase extraction, providing recoveries of 61.9–97.1% for leaves and 51.7–95.6% for roots. Four analytes were detected in parsley: enrofloxacin, tylosin, sulfamethoxazole, and doxycycline. Enrofloxacin was detected at the highest concentrations (13.4–26.3 ng g⁻¹). Doxycycline accumulated mainly in the roots, tylosin in the leaves, and sulfamethoxazole was found in both tissues. 14 transformation products were identified and their distribution were determined. This study provides important data on the uptake and transformation of pharmaceuticals in plant tissues.

Dipeptide nanoparticle and aptamer-based hybrid fluorescence platform for enrofloxacin determination

A novel fluorescence platform was fabricated for enrofloxacin determination by using cDNA-modified dipeptide fluorescence nanoparticles (FDNP-cDNA) and aptamer-modified magnetic Fe₃O₄ nanoparticles (Fe₃O₄-Apt). The FDNP were prepared via tryptophan-phenylalanine self-assembling. When magnetic Fe₃O₄-Apt incubated with standard solution or sample extracts, the target enrofloxacin was selectively captured by the aptamer on the surface of the Fe₃O₄ nanoparticles. After removing interference by washing with phosphate-buffered saline, the FDNP-cDNA was added, which can bind to the aptamer on the surface of the Fe₃O₄ nanoparticles not occupied by the analyte. The higher the concentration of the target enrofloxacin in the standard or sample solution is, the less the FDNP-cDNA can be bound with the Fe₃O₄ nanoparticles, and the more the FDNP-cDNA can be observed in the supernatant. Fluorescence intensity (E_x/E_m = 310/380 nm) increased linearly in the enrofloxacin concentration range 0.70 to 10.0 ng/mL with a detection limit of 0.26 ng/mL (S/N = 3). Good recoveries (88.17-99.30%) were obtained in spiked lake water, chicken, and eel samples with relative standard deviation of 2.7-6.2% (n = 3).

Antibiotic residues in environment: antimicrobial resistance development, ecological risks, and bioremediation

The overuse of antibiotics and their disposal without processing are leading the environment and its inhabitants towards a serious health emergency. There is abundance of diverse antibiotic resistance genes and bacteria in environment, which demands immediate attention for the effective removal of antibiotics. There are physical and chemical methods for removal, but the generation of toxic byproducts has directed the efforts towards bioremediation for eco-friendly and sustainable elimination of antibiotics from the environment. Various effective and reliable bioremediation approaches have been used, but still antibiotic residues pose a major global threat. Recent developments in molecular and synthetic biology might offer better solution for engineering of microbe-metabolite biodevices and development of novel strains endowed with desirable properties. This review summarizes the impact of antibiotics on environment, mechanisms of resistance development, and different bioremediation approaches.

Metabolic and transcriptional disruption of American shad (Alosa sapidissima) by enrofloxacin in commercial aquaculture

Antibiotics, including enrofloxacin (ENR), are widely used for bacterial disease treatment in aquaculture in China, resulting in their discharge into various aquatic environments. Therefore, researchers have focused their attention on the harmful effects of antibiotics on aquatic animal metabolism. To understand the impacts of ENR on the metabolism of cultured American shad, the guts of these fish were sampled to test the toxicity of ENR through the combined results of metabolomics and transcriptomics analyses. In this study, adult American shad were exposed to ENR (200 mg/kg) for 30 days. The results showed that ENR could significantly (p< 0.05) increase the body weight of American shad. ENR exposure also contributed to the dysregulation of intestinal metabolism (approximately 49 metabolites and 963 genes). Multiomics analyses of the responses indicated that the specific metabolic dysregulation caused by ENR affects many signaling pathways, such as the glycolysis/gluconeogenesis and pentose phosphate pathways, which are known to be linked with body weight gain through protein and lipid accumulation. In conclusion, ENR treatment affected the metabolic system in the gut of American shad. The transcriptomics and metabolomics analysis results provide essential data for evaluating antibiotic hazards in the guts of aquatic organisms.

Antibiotics: An overview on the environmental occurrence, toxicity, degradation, and removal methods

Antibiotics, as antimicrobial drugs, have been widely applied as human and veterinary medicines. Recently, many antibiotics have been detected in the environments due to their mass production, widespread use, but a lack of adequate treatment processes. The environmental occurrence of antibiotics has received worldwide attention due to their potential harm to the ecosystem and human health. Research status of antibiotics in the environment field is presented by bibliometrics. Herein, we provided a comprehensive overview on the following important issues: (1) occurrence of antibiotics in different environmental compartments, such as wastewater, surface water, and soil; (2) toxicity of antibiotics toward non-target organisms, including aquatic and terrestrial organisms; (3) current treatment technologies for the degradation and removal of antibiotics, including adsorption, hydrolysis, photodegradation and oxidation, and biodegradation. It was found that macrolides, fluoroquinolones, tetracyclines, and sulfonamides were most frequently detected in the environment. Compared to surface and groundwaters, wastewater contained a high concentration of antibiotic residues. Both antibiotics and their metabolites exhibited toxicity to non-target organisms, especially aquatic organisms (e.g., algae and fish). Fluoroquinolones, tetracyclines, and sulfonamides can be removed through abiotic process, such as adsorption, photodegradation, and oxidation. Fluoroquinolones and sulfonamides can directly undergo biodegradation. Further studies on the chronic effects of antibiotics at environmentally relevant concentrations on the ecosystem were urgently needed to fully understand the hazards of antibiotics and help the government to establish the permissible limits. Biodegradation is a promising technology; it has numerous advantages such as cost-effectiveness and environmental friendliness.

A novel electrochemiluminescence immunosensing strategy fabricated by Co(OH)2 two-dimensional nanosheets and Ru@SiO2-Au NPs for the highly sensitive detection of enrofloxacin

In this work, a novel sensitive electrochemiluminescence immunosensor based on Ru@SiO₂-Au NPs and Co(OH)₂ two-dimensional nanosheets (2D Co(OH)₂) is constructed for the detection of enrofloxacin (ENR). Ruthenium bipyridine silica spheres and modified gold nanoparticles were synthesized as immune probe materials, which were combined with ENR antibodies (Abs) to form the immune probe part. 2D Co(OH)₂ with a large specific surface area and good catalytic effect was firstly used as an immune substrate material, and at the same time, it was conjugated with the coating antigen (Ae) of ENR to form an immune substrate. Based on the principle of competitive immunity, ENR and ENR coated antigen could jointly compete for the specific binding sites on the ENR antibody, so as to achieve efficient detection of ENR. Under optimal conditions, the prepared immunosensor exhibited high sensitivity with a wide linear range from 0.0001 to 1000 ng mL^-1 and a low detection limit (LOD) of 0.063 pg mL^-1. The proposed immunosensor has been successfully applied to the detection of ENR residues in poultry, aquatic products and lake water.