Sulfonamide Residues Research Articles

Preparation and evaluation of polymeric ionic liquid functionalized microparticles as the efficient adsorbent for pipette tip solid phase extraction of sulfonamides

Sulfonamides (SAs) residues are commonly found in environmental samples, which is highly concerning for public safety and environmental protection. The detection of SAs is quite important but challenging. In this work, a kind of polymeric ionic liquid functionalized microparticles (PIL-FM) was synthesized via a simple free radical polymerization reaction, and applied as the adsorbent for pipette tip solid phase extraction (PT-SPE) of three SAs from river water, milk powder and honey samples. The adsorption performance of PIL-FM on SAs were evaluated using adsorption kinetics and adsorption isotherms, and the results showed that PIL-FM had the best selectivity for SMZ with the maximum adsorption capacity was as high as 45.05 mg·g−1. The extraction process was optimized and the adsorption mechanism was preliminarily discussed. PIL-FM has the excellent selectivity for SAs mainly because of the strong π-π interaction, and the electrostatic repulsion between them in the elution step also has a positive impact. Under optimal conditions, combined with HPLC, this PT-SPE method had wide linearity (0.2–100 μg·L−1, R2 ≥ 0.9998) and low limits of detection (0.06–0.08 μg·L−1). The intra-day and inter-day repeatability were found to be 3.7 %–4.6 % and 4.5 %–6.2 %, respectively. The suggested PT-SPE method is simple, low cost, rapid, and efficient to extract SAs, and can be applied for the monitoring of SAs residues in the aquatic environment and in food.

Assessment of Veterinary Antibiotic Use and Occurrence of Veterinary Antibiotics in Livestock Manure from Farms in Rongai Sub-County, Kenya

Veterinary antibiotics are commonly used in livestock rearing to prevent diseases and stimulate growth. The release of antibiotics into the environment has become a significant environmental and public health concern. This research evaluated antibiotic use, livestock treatment, manure utilization, livestock waste treatment methods and antibiotic residues in livestock manure. Questionnaires were administered to 170 farmers rearing both cattle and poultry. Subsequently, 28 livestock manure samples from 15 cattle and 13 poultry rearing farms were collected from various farms to assess concentrations of tetracyclines (Tetracycline, Oxytetracycline) and sulfonamides (Sulfadiazine, Sulfamethoxazole) residues. Residues analysis was done using High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD). Veterinarians were the most preferred in treating both cattle and poultry in farms. Tetracyclines and sulfonamides were the most consumed class of antibiotics among both poultry and cattle rearing farmers. Compost manure and Biogas were the most preferred use of animal waste within farms. Antibiotic presence in samples was detected in 80% and 93% of cattle and poultry manure respectively. Maximum antibiotic concentrations of 16.24 and 15.18 (mg/kg) were recorded in poultry and cattle manure, respectively. There was a statistically significant difference in antibiotic concentrations in poultry and cattle manure (P<0.05). The results of this research are important in monitoring rising concerns about veterinary antibiotics on environmental and public health.

Efficient extraction and HPLC determination of sulfonamide residues in milk samples using acylated graphene oxide-functionalized polyurethane sponges: A tailored approach for efficient analyte recovery

This study reports a novel surface modification of polyurethane sponge (PUS) with acylated graphene oxide (AGO), yielding a versatile sorbent material (AGO@PUS) for the efficient extraction of sulfonamide residues from milk samples. The AGO@PUS combines the extractive properties of AGO with the advantages of PUS, enabling easy, fast, cost-effective, and efficient sample preparation. The material was characterized using FTIR, SEM, XRD and the extraction protocol was optimized for the determination of three sulfonamides (SGD, SDS, and SDZ) by HPLC-UV. The proposed method exhibited excellent linearity (0.01–1000 µg mL−1), low limits of detection (0.04–0.06 µg mL−1) and quantification (0.13–0.21 µg mL−1), and high coefficients of determination (R2 = 0.993–0.997). The maximum recovery rate reached 99.63 %, demonstrating the exceptional sorption capacity of AGO@PUS. Notably, the clear extracts obtained with this material highlight its potential for efficient sample preparation and analysis.

Study on the Rapid Limit Test for Six Sulfonamide Residues in Food Based on the TLC-SERS Method.

Sulfonamides are not only widely applied in clinics but also highly valued in animal husbandry. Recently, it has become common for sulfonamide residues to exceed the standard limits in food, which can affect human health. Current regulations limit these residues. Therefore, we constructed a new limit test method to rapidly determine the levels of sulfonamide residues. Six sulfonamides were detected using the latest method called TLC-SERS, namely, sulfamethasone (A), sulfamethazine (B), sulfadoxine (C), sulfamethoxydiazine (D), sulfamethoxazole (E), and sulfathiazole (F). The optimal conditions for SERS detection were investigated for these six drugs, and the separation effects of different TLC spreaders on them were compared. Then, we successfully established a separation system using dichloromethane-methanol-ammonia in a ratio of 5:1:0.25 (v/v/v), which provided good separation effects on the six drugs. The residues were preliminarily separated via TLC. A silver sol solution was added to the spot on the silica gel G plate at the corresponding specific shift values, and SERS detection was performed. The sample solution was placed on the spot under a 532 nm laser, and the SERS spectrum was collected and analyzed for the six sulfonamides. The results showed obvious variations in the SERS spectrum among the six sulfonamides, with the LODs being 12.5, 6.4, 6.3, 7.1, 18.8, and 6.2 ng/mL from A to F, respectively, and an RSD of <3.0%. Within 48 h, the SERS signal for each sulfonamide drug was kept stable, with an RSD of <3.0%. The detection results of 20 samples using the TLC-SERS method were consistent with those obtained by UPLC-MS/MS. The established TLC-SERS method is simple and fast, providing a useful reference for the rapid detection of residue limits in food.

Isolation of aptamers with excellent cross-reactivity and specificity to sulfonamides towards a ratiometric fluorescent aptasensor for the detection of nine sulfonamides in seafood

Sulfonamides (SAs) is a class of antibiotics that extensively used for treating infectious diseases in livestock industries and aquaculture. Thus, it is urgent need to obtain the bio-receptor, which has excellent cross-reactivity and specificity to SAs, for developing high-throughput methods for the determination of multiple SAs even all commonly-used SAs, to realize the quick screening/detection of total SAs in animal-derived foods. We herein isolated several SAs-specific cross-reactive aptamers by using a library-immobilized SELEX with multi-SAs parallel selection strategy. Two of the isolated aptamers (Sul-01 and Sul-04) can specifically recognize and bind seven SAs respectively with higher binding affinity and no interference of non-sulfonamide antibiotics, and thus can be applied as bio-receptors for developing high-throughput aptasensors for the quick screening/detection of multiple SAs. By using the mixture of Sul-01 and Sul-04 as bio-receptor, a ratiometric fluorescent aptasensor was created for the quick detection of nine SAs including sulfamethoxydiazine (SMD), sulfapyridine (SPD), sulfaquinoxaline (SQ), sulfathiazole (ST), sulfamonomethoxine (SMM), sulfamerazine (SMR), sulfaguanidine (SG), sulfamethazine (SMZ) and sulfadiazine (SD) with a detection limit (LOD) of 0.10–0.50 μM, or total of above nine SAs with a LOD of 0.20 μM. The fluorescent aptasensor was successfully applied to detect each or total of SMD, SPD, SQ, ST, SMM, SMR, SG, SMZ and SD in fish samples with a recovery of 83 %–92 % and a relative standard deviation (RSD, n = 5) < 5 %. This study not only provided several promising bio-receptors for the development of diverse high-throughput aptasensors to achieve the quick screening of multiple SAs residues, but also provided a simple, stable and sensitive method for the quick screening of SMD, SPD, SQ, ST, SMM, SMR, SG, SMZ and SD in seafood.

Analysis of Antibiotics in Milk from Smallholder Farmers from Kenya Shows Traces Above the Recommended Maximum Residue Limits

Antimicrobial resistance (AMR) is rising globally and is likely to cause more deaths because of antibiotic-resistant microbial infections and antibiotic residues in animal foods and products as a result of misuse of antibiotics in dairying. Thus, we determined the presence and quantities of sulfonamide, tetracycline, and beta-lactam drug residues in milk sampled in Nyandarua, Meru, and Kiambu counties in Kenya using the Charm TRIO® test kit and liquid chromatography (LC) coupled to the triple quadrupole mass spectroscopy (MS) (LC-MS/MS). The TRIO® test kit showed dicloxacillin as the most prevalent at 9.3%, followed by penicillin and cloxacillin at 3.7% each, and nafcillin at 0.9% among the beta-lactams. Among the tetracyclines, demeclocycline and tigecycline were the most prevalent at 10.3% each, followed by oxytetracycline at 9.3%, chlortetracycline at 7.5%, and doxycycline at 3.7%, while sulfaquinoxaline was the only sulfonamide drug detected at 4%. The LC-MS/MS detected the presence of all the tested β-lactam and tetracycline antimicrobial traces and all sulfonamide drugs except sulfamerazine in all three counties. All the tetracycline antibiotics recorded between 3 and 10.5% of antibiotic residues above the recommended Maximum Residue Levels (MRLs) in milk across all three counties, with beta-lactam antibiotics recording between 2 and 33.3%, indicating their misuse in the three counties. Sulfaquinoxaline was the only sulfonamide detected in milk samples above the recommended MRLs, indicating sulfonamides are less used in those counties. Therefore, it is important to enforce a regulatory framework to control antibiotic use in livestock to minimize potential health risks related to their traces in the foods.

Determination of sulfonamide antibiotics by magnetic porous carbon solid-phase extraction coupled with capillary electrophoresis

Sulfonamide antibiotics (SAs) have been widely used as antibacterial drugs for the prevention and treatment of livestock and poultry diseases, but they seriously threaten human health because they can accumulate in humans. Therefore, it is highly important to develop methods for monitoring sulfonamide residues in aquaculture and food. In this research, based on the generation of porous carbon (PC) by the pyrolysis of sodium citrate, magnetic porous carbon (PC@Fe3O4) was synthesized by a solvothermal method and used as an adsorbent for the magnetic solid-phase extraction of SAs. The effects of the proportion of PC in PC@Fe3O4, adsorbent dosage, adsorption time, eluent type, extraction pH, salt concentration and eluent dosage on the extraction efficiency were systematically studied. The adsorption performance and behavior of PC@Fe3O4 on SAs were evaluated using adsorption kinetics and adsorption isotherms, and the adsorption mechanism was preliminarily discussed. Under optimal conditions, combined with capillary electrophoresis diode array detection, a sensitive detection method for SAs was developed. The proposed method can be used for the determination of six SAs in fishpond water and milk samples, with a linear range of 0.5–200 ng mL−1, detection limits of 0.24–0.34 ng mL−1, and spiked recoveries of 85.9–109.0 %.

A dual-mode fluorometric/colorimetric sensor for sulfadimethoxine detection based on Prussian blue nanoparticles and carbon dots.

A dual-mode (colorimetric/fluorescence) nanoenzyme-linked immunosorbent assay (NLISA) was developed based on Au-Cu nanocubes generating Prussian blue nanoparticles (PBNPs). It is expected that this method can be used to detect the residues of sulfonamides in the field, and solve the problem of long analysis time and high cost of the traditional method. Sulfadimethoxine (SDM) was selected as the proof-of-concept target analyte. The Au-Cu nanocubes were linked to the aptamer by amide interaction, and the Au-Cu nanocubes, SDM and antibody were immobilized on a 96-well plate using the sandwich method. The assay generates PBNPs by oxidising the Cu shells on the Au-Cu nanocubes in the presence of hydrochloric acid, Fe3+ and K3[Fe (CN)6]. In this process, the copper shell undergoes oxidation to Cu2+ and subsequently Cu2 + further quenches the fluorescence of the carbon point. PBNPs exhibit peroxidase-like activity, oxidising 3,3',5,5'-tetramethylbenzidine (TMB) to OX-TMB in the presence of H2O2, which alters the colorimetric signal. The dual-mode signals are directly proportional to the sulfadimethoxine concentration within the range 10- 3~10- 7 mg/mL. The limit of detection (LOD) of the assay is 0.023 ng/mL and 0.071 ng/mL for the fluorescent signal and the colorimetric signal, respectively. Moreover, the assay was successfully applied to determine sulfadimethoxine in silver carp, shrimp, and lamb samples with satisfactory results.

Evaluation of some sulfonamide antibiotics residues in chicken meat samples using in-syringe counter current homogenous liquid–liquid extraction and magnetic deep eutectic solvent-based dispersive liquid–liquid microextraction and HPLC–DAD

A sample pretreatment method based on the combination of counter current salting-out homogenous liquid–liquid extraction and magnetic deep eutectic solvent-based dispersive liquid–liquid microextraction was developed and employed for the extraction of some sulfonamide antibiotics from chicken meat samples. For this purpose, first, a homogenous solution of acetonitrile and deionized water was passed through a syringe barrel filled sodium chloride and chicken meat sample. By doing so, the fine droplets of acetonitrile were produced and collected on the surface of solution. In the following, this phase containing the extracted analytes was taken and injected into deionized water after mixing with [Choline: 4-chlorophenol]+[FeCl4]- magnetic deep eutectic solvent. Then, the magnetic deep eutectic solvent droplets were separated in the presence of an external magnetic field and injected into high performance liquid chromatography-diode array detector for quantitative analysis. Based on the validation results, low limits of detection (0.15–0.24 ng g−1) and quantification (0.51–0.80 ng g−1), high extraction recovery (67–78 %), and good precision (relative standard deviations ≤ 5.7 %) were obtainable by using the offered method. Finally, the suggested method was employed for the quantification of the studied sulfonamide antibiotics in various chicken meat samples.

Optimization and performance evaluation of a fluorescent sensor for residual sulfonamide antibiotics in honey samples

AbstractIn the quest to address the mounting concerns over sulfonamide antibiotic residues in food, which pose significant threats to public health and food safety, this study introduces a cutting‐edge detection method. Surface molecular imprinting on silicon nanoparticles is harnessed to fabricate a novel fluorescent sensor that exploits the luminescent properties of cadmium telluride (CdTe) quantum dots. This innovative approach aims to detect residual sulfonamide antibiotics with high specificity and sensitivity. At the heart of this research is the development of a core‐shell nanostructure, where silicon dioxide serves as the core, and a molecularly imprinted polymers (MIPs) layer, tailored to recognize sulfamethazine (SM2), forms the shell. The pivotal advancement in this sensor design is the integration of highly fluorescent CdTe quantum dots within the MIPs layer, which significantly enhances the signal response, enabling the detection of SM2 with remarkable precision. The synthesis of this sensor employs a novel strategy, utilizing 3‐aminopropyltriethoxysilane as the functional monomer, while tetraethyl orthosilicate and ammonium hydroxide act as catalysts to facilitate the polymerization reaction. This meticulous process yields a stable core‐shell structure with active fluorescent properties. Experimental results reveal that under optimal conditions, the sensor exhibits a robust linear response to SM2 concentrations ranging from 10 to 60 μmol L−1, with a detection limit as low as 0.78 μmol L−1. Furthermore, when applied to real food samples, such as honey, the sensor not only demonstrates high recovery rates of 92.3%–98.1%, but also maintains a low relative standard deviation of less than 2.5%. The implications of this study are far‐reaching, offering a promising avenue for the rapid and reliable monitoring of antibiotic residues in the food supply chain, thereby safeguarding consumer health and upholding food safety standards.

Green application of surfactant modified silica as effective sorbent for extraction and preconcentration of sulfonamide residues in environmental water and honey samples

Micro-solid phase extraction (µ-SPE) using surfactant coated silica for extraction and preconcentration of sulfonamide residues at trace levels in environmental water and honey samples prior their analysis by high performance liquid chronatography coupled with photodiode array detector (HPLC-PDA). The sample solution were dispersed in a small amounts of solid sorbent by vacuum manifold for sample preparation, and extraction occurred by adsorption in a short time. Finally, the analytes were subsequently desorbed using an appropriate solvent. The pure and coated silica were physicochemically and morphologically characterized by nittrogen (N2) sorptions analyses, and transmission electron microscopy (TEM). Parameters influencing extraction efficiency, such as amount of sorbent, kind, concentration and volume of surfactant, and kind and volume of desorption solvent, were investigated. The optimum conditions of the proposed method, were mixed standard/sample solution (10 mL), 0.4 g silica, 0.03 M CTAB (150 µL), and 500 μL methanol (as elution solvent). The proposed method, under optimal conditions, showed excellent linearity in different ranges (9–300 μg L−1, the a coefficient of determination (R2) of greater than 0.99), good repeatability (RSD < 6.72 %), good sensitivity (LODs in the range of 1 to 3 µg L−1), high enrichment factor (5.63–13.33), and acceptable relative recoveries (61.0–121.4 %). The developed µ-SPE method was applied to analyze sulfonamide residues in water and honey samples with relative recoveries of 60.9–119.4 % were obtained. This alternative method is simple and is also environmentally friendly which assessed using Analytical Eco-scale and Analytical GREEnness metric (AGREE).

One-pot derivatization/magnetic solid-phase extraction coupled with liquid chromatography-fluorescence detection for the rapid determination of sulfonamide residues in honey

Consuming foods with excess sulfonamide residues threatens human health, underscoring the importance of their detection in food. This study presents an innovative one-pot derivatization/magnetic solid-phase extraction (OPD/MSPE) method for sulfonamides analysis. This approach integrates the derivatization and extraction steps into a single process. The sample solution, along with the derivatization reagent fluorescamine and the sorbent magnetic hydroxyl multi-walled carbon nanotubes, is mixed and vortexed for 3 min. This procedure simultaneously conducts derivatization and extraction, with easy phase separation using an external magnet. This streamlined sample preparation method is completed in only 5 min and, when combined with liquid chromatography-fluorescence detection (LC-FLD), demonstrates excellent linearity (R2 > 0.99) and satisfactory detection limits (0.004–0.04 ng/g) for the quantification of nine sulfonamides in honey samples. The proposed OPD/MSPE-LC-FLD method is distinguished by its simplicity, rapidity, high sensitivity, and specificity, making it an outstanding advancement in the field of food safety analysis.

Status of antibiotic residues in milk and dairy products of Iran: a systematic review and meta-analysis.

Today, antibiotics are widely used for treatment and feed additives to enhance livestock growth. Antibiotic residues may be found in food of animal origin for various reasons, including ignoring the withdrawal period after treatment, overuse for animals, and contamination of feed with treated animals in animal products. Among animal products, dairy products have a special place in the human diet, and antibiotic residues in them have caused a great deal of concern among consumers. This systematic review and meta-analysis aimed to evaluate and compare studies conducted in Iran on antibiotic residues in dairy products during 2000-2022. In this review, 52 eligible studies were collected by searching the Scientific Information Database (SID), Magiran, Google Scholar, Science-Direct, Scopus, and PubMed using the English or Persian keywords such as an antibiotic or antimicrobial residue, Beta-lactam residue, Tetracycline residue, Sulfonamide residue, Chloramphenicol residue, Aminoglycosides residue, Macrolide residue, Quinolones residue, Milk, Raw milk, Pasteurized milk, UHT milk, Powder milk, Cheese, Yogurt, Butter, Cream, Doogh, Kashk, Ice cream, and Iran. According to the reviewed studies, the total prevalence of antibiotic residues in dairy products was 29% (95% CI: 15-43%). Among the seven evaluated antibiotic groups, most studies have been conducted on tetracycline, beta-lactam, and sulfonamide groups, with 16, 10, and 7 respectively, and the highest level of contamination with 663 ± 1540μg/l is related to tetracycline. Most studies on antibiotic dairy product residues in Iran with 12, 11, and 8 studies are associated with East Azarbaijan province, then Tehran and Khorasan Razavi respectively, and no study has been conducted in 11 provinces of the country. According to the studies, Gilan, Qazvin and Razavi Khorasan provinces had the highest amount of antibiotic residue in milk with an average value of 56.415 ± 33.354, 45.955 ± 4.179 and 45.928 ± 33.027, respectively. Most of the methods used in the studies to measure antibiotic residues in milk were the Copan test kit and the HPLC method, which were used in 19 and 14 studies, respectively. Studies have shown that the prevalence of antibiotic residue in dairy products in Iran is high, so applying an effective strategy and developing the necessary standards in this field to control milk quality is a public health necessity. The findings of this study show that further evaluation of fermented dairy products, especially non-fermented ones such as butter and cream, is needed to prevent adverse health reactions.

The Synthesis and Antibacterial Properties of Pillar[5]arene with Streptocide Fragments.

The growing problem of bacterial resistance to antimicrobials actualizes the development of new approaches to solve this challenge. Supramolecular chemistry tools can overcome the limited bacterial resistance and side effects of classical sulfonamides that hinder their use in therapy. Here, we synthesized a number of pillar[5]arenes functionalized with different substituents, determined their ability to self-association using DLS, and characterized antimicrobial properties against S. typhimurium, K. pneumoniae, P. aeruginosa, S. epidermidis, S. aureus via a resazurin test. Biofilm prevention concentration was calculated for an agent with established antimicrobial activity by the crystal-violet staining method. We evaluated the mutagenicity of the macrocycle using the Ames test and its ability to affect the viability of A549 and LEK cells in the MTT-test. It was shown that macrocycle functionalized with sulfonamide residues exhibited antimicrobial activity an order higher than pure streptocide and also revealed the ability to prevent biofilm formation of S. aureus and P. aeruginosa. The compound did not show mutagenic activity and exhibited low toxicity to eukaryotic cells. The obtained results allow considering modification of the macrocyclic platforms with classic antimicrobials as an opportunity to give them a "second life" and return to practice with improved properties.

Flexible silver ring SERS substrate array fabrication by vortex evaporation method and its application for high sensitive detection of sulfonamides residues in water

Flexible surface-enhanced Raman scattering (SERS) substrates have driven much attention in Raman detection of environmental pollutants due to their unique advantage of sensitivity, low-cost and fast sampling. However, it is still a high challenge for fabricating flexible SERS substrate with high reproducibility and sensitivity. In this study, we developed a novel silver nanoparticle assembly method based on vortex evaporation method to batch assemble multiple silver ring (SR) SERS substrate array on a parafilm. The flexible SR SERS substrates were uniformly covered with active silver nano-islands, which significantly improved the Raman signal intensity of the targets by 126 folds and showed 5 times Raman enhancement compared with the common SERS substrate by direct evaporation method, and also represented the unique bending response properties of flexible substrate. The Raman detection for sulfonamide residues in water with SR SERS substrate represented high sensitivity, which limits of detection for Sulfapyridine and Sulfacloropyridazine were 9.46 and 9.3 × 10−8 mol/L, respectively. The quantitative relationships were obtained in wide linear range of 4 orders with good accuracy and stability. The flexible SR SERS substrate array can be large-scale prepared with good repeatability, stability, and low-cost, which has promising applications for trace contaminants detection in water environment.

Occurrence and Health Risk Assessment of Sulfonamide Antibiotics in Different Freshwater Fish in Northeast China.

This study aimed to investigate the levels of 12 sulfonamide antibiotics in freshwater fish species obtained from three cities in northeastern China (Harbin, Changchun, and Shenyang). The analysis was conducted using HPLC-MS/MS to accurately quantify the antibiotic concentrations in the fish samples. The results showed that the average levels of sulfonamide antibiotics in fish samples from Harbin, Changchun, and Shenyang were 1.83 ng/g ww, 0.98 ng/g ww, and 1.60 ng/g ww, respectively. Sulfamethoxazole displayed the highest levels and detection rates in all three cities, whereas sulphapyridine exhibited the lowest concentrations in all the fish samples. The levels of sulfonamide antibiotic residues in the different fish species varied widely among the cities, and the highest level of antibiotic residues was found in the muscle of carnivorous fish. The results from a health risk evaluation on the consumption of these fish indicated that the risk from long-term antibiotic exposure to local residents from the intake of the sampled fish was small and not sufficient to pose a significant health risk to consumers.

Development of a receptor based signal amplified fluorescence polarization assay for multi-detection of 35 sulfonamides in pork.

With the increasing focus on food security, a screening method with high-throughput, ultra-sensitivity, and user-friendly operation is urgently needed for monitoring of sulfonamides residues in animal-derived foods. In this study, the sulfonamides' receptor dihydropteroate synthase of Staphylococcus aureus was subjected to saturate mutation, and a mutant with higher affinities for sulfonamides was obtained. The mutant was then used as recognition material to establish a fluorescence polarization assay for determination of 35 sulfonamides in pork. Due to the use of an enhanced fluorescent tracer containing two fluorophore molecules, the sensitivities for the 35 sulfonamides were improved for 2.8-8.6 folds (LODs 0.03-1.16ng/mL) in comparison with using conventional fluorescent tracer.The present method outperformed all previous fluorescence polarization (immuno)assays for sulfonamides due to its broader spectrum, higher sensitivity, and shorter assay time. Furthermore, this is the first study reporting an enhanced fluorescence polarization assay for determination of small molecule substance.

Current Status and Spatiotemporal Evolution of Antibiotic Residues in Livestock and Poultry Manure in China

The use of antibiotics in the livestock and poultry industries has raised significant concern about environmental and health problems. In light of this, accurate knowledge of antibiotic residues in livestock and poultry manure is important for pollution management and strategic decision-making at the national level. This study aims to provide a comprehensive report on antibiotic residues in livestock and poultry manure in China using the published data of 3751 livestock and poultry feces in 29 provincial-level units over the past 20 years. In this study, the overall status of antibiotic residues in livestock and poultry feces was analyzed by mathematical statistics. Moreover, the spatio-temporal variation characteristics were analyzed by spatial statistics, and the differences among livestock and poultry species were evaluated by subgroup analysis. The finding indicated that tetracyclines (TCs), quinolones (QLs), sulfonamides (SAs), and macrolides (MLs) were the most abundant residues in livestock and poultry manure. The spatial and temporal variation revealed that the overall trend of antibiotic residues decreased gradually, and the spatial distribution was primarily concentrated in the southeast of Hu Line, exhibiting a “northeast-southwest” distribution. The distribution range also decreased slightly, with the residues of tetracyclines (TCs), quinolones (QLs), sulfonamides (SAs), and pleuromutilins (PMs) showing a significant spatial hot spot. The center of gravity of antibiotic residue shifted to the southwest between 2003 and 2021. In comparison to cow and sheep manure, the tetracyclines (TCs), sulfonamides (SAs), and macrolides (MLs) in pig and chicken manure were higher. The results can serve as a reference for the control and reduction of antibiotic pollution in livestock and poultry manure, as well as the wise utilization of those resources and achieving goals for clean agriculture.

Contamination of long-term manure-fertilized Indian paddy soils with veterinary antibiotics: Impact on bacterial communities and antibiotics resistance genes

In the present study, we investigated the implication of long-term fertilization of Indian rice paddies with animal manures on the prevalence of veterinary antibiotics (VAs) residues, enrichment of soil microorganisms, and abundance of antibiotic resistance genes (ARGs). The most frequently detected antibiotics in Indian paddy soils were tetracyclines followed by sulfonamides. The soils long-term fertilized with poultry manure (PM) and cow manure (CM) contained significant amounts of VAs (137.20 μg kg−1) in soil. Members of Actinobacteria, Streptomyces, Rubrobacter, Pseudonocardia, Pseudomonas and Rhizobium were predominant in soils that received PM or CM. ARGs such as mtrA, arlR, bcrA, novA, oleC, sul4 and kdpE that confer resistance mostly to macrolides, aminocoumarins, multi-drugs, and sulfonamides were predominant, and the main phyla that contributed ARGs included Actinobacteria (55 %) and Proteobacteria (22 %). Antibiotic modification/degradation was the major (58.30 %) antibiotic resistance mechanism in bacteria enriched in long-term fertilized soils. Residues of tetracyclines, quinolones, sulfonamides, Cu and Cd in soils positively correlated with ARGs. Notably, this study is the first evidence on the prevalence of VAs, antibiotic-resistant microbes, and ARGs in paddy soils of India long-term fertilized with PM or CM and shed light on the interactions between antibiotics, heavy metals and ARGs.

Behavioral and ecotoxicology of sulfonamide metabolites in the aquatic environment.

Sulfonamides (SAs) are the first broad-spectrum synthetic antimicrobial agents used in human health and veterinary medicine. The majority of SAs entering human body is discharged into aquatic environment in the form of parent material or metabolites. The residues of SAs and their metabolites in the aquatic environment and the development of drug resistance can be serious threats to ecosystems and human health. We summarized recent advances in the research of SAs. The main metabolite types of SAs and the distribution characteristics of metabolites in different aquatic environments were introduced. The ecotoxicology of SAs metabolites, especially the distribution and hazards of sulfonamide resistance genes (sul-ARGs), were discussed with emphasis. Finally, the future research works were proposed. This paper could provide basic information for further research on SAs.