Sulfonamide Research Articles

Adsorbent beads based on Fe-BTC@Chitosan/microcrystalline cellulose for simultaneous removal of sulfa drugs

Adsorbent beads based on Fe-BTC@Chitosan/microcrystalline cellulose for simultaneous removal of sulfa drugs

Degradation of sulfamethoxazole in a falling film dielectric barrier discharge system: Performance, mechanism and toxicity evaluation

The ubiquitous presence of sulfonamides (SAs) in wastewater poses serious risks to human health and ecosystem safety. This study evaluated the performance of a falling film dielectric barrier discharge (DBD) system on the removal of five SAs, namely sulfamethoxazole (SMX), sulfisoxazole (SIZ), sulfathiazole (STZ), sulfadiazine (SDZ) and sulfamerazine (SMR). Removal efficiencies >99 % were observed for all target SAs within 30 min of treatment, with pseudo-first order rate constants varying between 0.17 and 0.27 min−1. Superior removal efficiencies were achieved under acidic conditions compared to neutral and alkaline conditions. Using SMX as a model compound, mechanistic investigations revealed that the synergy of reactive oxygen species (ROS) and reactive nitrogen species (RNS) led to its efficient degradation, with peroxynitrites (ONOO−/ONOOH) and hydroxyl radical (OH) playing pivotal roles. SMX degradation pathways encompassing nitration/nitrosation, hydroxylation, deamination, CS and SN bond cleavage were proposed. The toxicity evaluation results demonstrated that the solution toxicity diminished following the plasma treatment under specific conditions. In particular, the solution treated with air or oxygen discharge enhanced the growth of wheat seedlings, suggesting the potential for reusing plasma-treated wastewater in agriculture. This study enhances our understanding of the underlying mechanisms involved in the plasma degradation of SAs and reveals the significant potential of plasma technology as a sustainable approach for treating wastewater.

Rapid and Simultaneous Determination of 13 Sulfonamides in Soil by Matrix Solid-Phase Dispersion With High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Sulfonamides, the most frequent antibacterial agent, are widely used due to their low cost and excellent antibacterial effect. With the emergence of the environment, the potential hazard to the ecological environment has attracted the great attention of humans. Based on matrix solid-phase dispersion coupled with high-performance liquid chromatography-tandem mass spectrometry, an accurate, fast, and sensitive analytical method was developed for the determination of sulfonamides (SAs) in soil. Several influencing factors including the type of dispersants, the ratio of sample-to-sorbent, eluents, and solvent volume were investigated, and the matrix effects were evaluated. Under optimized conditions, the calibration curves exhibited excellent linearity with correlation coefficients (r) exceeding 0.996. The limit of detection (based on signal-to-noise ratio [S/N]=3) and limit of quantification (based on S/N=10) were 0.024-0.058 and 0.079-0.195µg/kg, respectively. The recoveries ranging from 70.12% to 123.63% were obtained with a relative standard deviation of less than 15% at three levels (20, 40, and 200µg/kg). The developed method was successfully applied to analyze 13 SAs at trace levels in a real soil sample. This proposed method would be an alternative and suitable for routine application in the future owing to its rapidity, sensitivity, and affordability.

Ecological influences of sulfadiazine on rhizosphere soil microbial communities in ryegrass (Lolium perenne L.)-soil potting systems: Perspectives on diversity, co-occurrence networks, and assembly processes.

Microorganisms in the soil are crucial constituents of land ecosystems, significantly influencing their structure and functionality. However, the accumulation of antibiotics in agricultural practices may negatively affect these microbial communities. The objective of this study was to explore the ecological effects of the sulfonamide drug sulfadiazine (SDZ) on the rhizosphere soil microbial communities of ryegrass (Lolium perenne L.). A potting system experiment was constructed by exposing for 45 days after treatments with different initial concentrations of SDZ (0, 1, 10, and 30 mg/kg) to assess the effects of SDZ on soil microbial diversity, bacterial-fungal co-occurrence networks, and community assembly processes. The findings indicated that SDZ treatment significantly altered the community composition, especially for bacteria in the phylum Proteobacteria and Gemmatimonadota and fungi in the phylum Mortierellomycota and Aphelidiomycota. Network analysis revealed that SDZ stress caused alterations in microbial interaction patterns, especially at high treatment concentrations, and reduced network connectivity. In addition, SDZ significantly affected microbial community assembly processes, where stochastic processes were enhanced in bacterial communities, while fungal communities showed a balance of stochastic and deterministic processes. Analysis of environmental variables revealed that the presence of SDZ may disrupt the link between soil microorganisms and soil nitrogen compounds. The results provide new perspectives for understanding the ecological impacts of antibiotic residues in agroecosystems and provide a scientific basis for soil health management.

Construction of “organic–inorganic” hierarchical structure of carbon fibers and the effect on the properties of epoxy composites

AbstractThe demand for epoxy (EP) in semiconductor, aerospace, and other applications is currently on the rise. However, pure epoxy is difficult to meet these requirements, such as low thermal conductivity and poor toughness. Therefore, in this paper, sulfonamides (SAs) and core‐shell silica (SLC‐SiO2) were grafted onto the surface of short carbon fibers (SCF) with sizes of 0.1–6 mm by the chemical grafting method. As a result, the surface activity of SCF was improved and the interfacial properties of the EP composites were enhanced. The interfacial compatibility of SCF grafted with SAs and SLC‐SiO2 in EP is greatly improved, resulting in stronger mechanical interlocking and chemical bonding ability between EP and SCF. The results showed that when the content of SCF@SAs@SLC‐SiO2/EP composites reached 0.3 wt% of SCF@SAs@SLC‐SiO2, the impact and tensile strengths were increased from 12.15 kJ·m−2 and 43.4 MPa to 16.93 kJ·m−2 and 74.97 MPa compared with the pure epoxy, which were improved 39.3% and 72.7%. In addition, the thermal conductivity of SCF@SAs@SLC‐SiO2/EP composites was also improved by 12.5% from 0.205 W·(m·K)−1 to 0.2306 W·(m·K)−1 compared with the pure EP. This is due to improved chemical interactions and mechanical interlocking at the fiber‐epoxy interface. This study provides a new method for the preparation of high‐performance SCF/EP composites.Highlights The amino group of sulfonamides was grafted with short carbon fiber to increase the surface active group of short carbon fiber. Sulfonamides react with carboxyl groups on the surface of core‐shell silica to form an “organic–inorganic” structure. Improve the surface roughness of short carbon fiber, and make it evenly dispersed in epoxy resin, so as to improve the performance of epoxy composite materials.

Source apportionment and ecological risk assessment of antibiotics in Dafeng River Basin using PMF and Monte-Carlo simulation.

Antibiotics, prevalent in aquatic ecosystems, pose a grave threat to human health and the ecological well-being. This paper performed a case study on Dafeng River Basin in southern China. Specifically, techniques including positive matrix factorization (PFM) and Monte-Carlo simulation were employed to comprehensively investigate the spatial variations, possible sources, and ecological risks of antibiotics in four groups: sulfonamides (SAs), macrolides (MLs), quinolones (QNs), and tetracyclines (TCs). The major findings were as follows: first, 43 and 39 antibiotics were detected in the surface water and sediments of the basin, respectively, where the respective total content were ND-490.08ng/L and ND-144.34μg/kg, and the QNs and TCs were the two dominating groups. Second, the highest antibiotic content in surface water (441.43ng/L) was observed in the midstream area, whereas the highest concentration in sediments (68.41μg/kg) was found in the upstream region. Third, the investigation identified five sources of antibiotics discharged to surface water: domestic sewage, agricultural drainage, livestock discharge, sewage treatment plants, and aquaculture; three sources were detected for antibiotics in sediments: aquaculture, sewage treatment plants, and livestock discharge. Fourth, QNs had a significantly higher ecological risk than the other three groups of antibiotics, and livestock discharge (31.4% contribution) and aquaculture (23.4% contribution) were the main sources of risks of antibiotic contamination in Dafeng River Basin. This study is expected to provide some reference for control and risk management of antibiotic pollution in Dafeng River Basin.

Exploration of the Solubility Hyperspace of Selected Active Pharmaceutical Ingredients in Choline- and Betaine-Based Deep Eutectic Solvents: Machine Learning Modeling and Experimental Validation.

Deep eutectic solvents (DESs) are popular green media used for various industrial, pharmaceutical, and biomedical applications. However, the possible compositions of eutectic systems are so numerous that it is impossible to study all of them experimentally. To remedy this limitation, the solubility landscape of selected active pharmaceutical ingredients (APIs) in choline chloride- and betaine-based deep eutectic solvents was explored using theoretical models based on machine learning. The available solubility data for the selected APIs, comprising a total of 8014 data points, were collected for the available neat solvents, binary solvent mixtures, and DESs. This set was augmented with new measurements for the popular sulfa drugs in dry DESs. The descriptors used in the machine learning protocol were obtained from the σ-profiles of the considered molecules computed within the COSMO-RS framework. A combination of six sets of descriptors and 36 regressors were tested. Taking into account both accuracy and generalization, it was concluded that the best regressor is nuSVR regressor-based predictive models trained using the relative intermolecular interactions and a twelve-step averaged simplification of the relative σ-profiles.

A Voltage-Controlled Strategy for Modular Shono-Type Amination.

Shono-type oxidation to generate functionalized heterocycles is a powerful method for late-stage diversification of relevant pharmacophores; however, development beyond oxygen-based nucleophiles remains underdeveloped. The limited scope can often be ascribed to constant current electrolysis resulting in potential drifts that oxidize a desired nucleophilic partner. Herein, we report a voltage-controlled strategy to selectively oxidize a broad scope of substrates, enabling modular C-N bond formation from protected amine nucleophiles. We implement an electroanalytically guided workflow using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) to identify oxidation potentials across a range of heterocyclic substrates. Controlled potential electrolysis (CPE) selectively generates α-functionalized C-N products in moderate to good yields using carbamate-, sulfonamide-, and benzamide-derived nucleophiles. The importance of voltage control is further exemplified through a systematic study comparing our developed CPE method to constant current electrolysis (CCE) protocols. Voltage-guided CCE and traditionally optimized CCE reveal the importance of maintaining voltage control for high yields and selectivity over a broad scope; a case study with a morpholine-derived substrate illustrates the negative impact of potential drifting under CCE. Sulfonamide drugs, which have significant oxidation potential overlap with model substrates, are rendered competent nucleophiles under CPE. Lastly, sequential voltage-controlled C-N and C-O functionalization of a model substrate generates difunctionalized pyrrolidines further broadening the utility of this reaction.

B-204 A Real-time Probe-based PCR Assay for Detection of Pneumocystis Pneumonia

Abstract Background Pneumocystis jirovecii is an atypical opportunistic fungus with lung tropism and worldwide distribution that continues to be one of the major opportunistic pathogens causing severe Pneumocystis pneumonia (PcP) in individuals with acquired immune deficiency syndrome (AIDS) and patients with immunosuppression due to other causes. Widespread prophylaxis and treatment for P. jirovecii with sulfa drugs have decreased the incidence of PcP, but concerns have been raised about the possible emergence of P. jirovecii isolates resistant to these drugs. Point mutations in this gene have been associated with prior exposure to sulfa drugs in other microorganisms, the polymorphic positions 165 and 171, which lead to an amino acid change at positions 55 (Thr55Ala) and 57 (Pro57Ser) of the polypeptide chain, respectively. Fluorescent PCR technology can detect the nucleic acid fragments of P. jirovecii in patients' serum, alveolar perfusion fluid (BALF) and tissue samples, and further identify drug-resistant mutations, which is of great significance for early clinical and accurate initiation of antifungal therapy. MycoMDx Pneumocystis Jirovecii PCR Assay is the use of PCR-fluorescence probe method, combined with other methods to achieve the auxiliary diagnosis of P. jirovecii infection and resistance to sulfonamides (Fig. 1). Methods In this study, we did a performance evaluation of the MycoMDx Pneumocystis Jirovecii PCR Assay (CE-approved), including diagnostic sensitivity and specificity, the limit of detection (LoD), precision and stability. The above PCR assay reagents were developed and produced by Dynamiker Biotechnology (Tianjin) Co., Ltd. Results The sensitivity and specificity of the PCR assay reagents were above 90%, the LoD was 1000 copies/mL, and the precision and stability were in accordance with the requirements (CV≤5%). Conclusions The MycoMDx Pneumocystis Jirovecii PCR Assay has great clinical value by providing a rapid and reliable test to aid in early diagnosis.

Polyacrylonitrile nanofibrous mat modified with cysteamine and ionic liquid as a recyclable and efficient adsorbent for selective removal of sulfonamides and Cu(II) from aqueous solution: Roles of multi-function adsorption

The combined contamination of heavy metals and antibiotics is a prevalent occurrence, yet the distinct chemical characteristics of these substances pose a significant obstacle to their simultaneous elimination. In this work, novel polyacrylonitrile nanofibrous mat (NFsM) modified with cysteamine and ionic liquid (IL@Cys@PAN NFsM) was developed using a cascade thiol-ene click reaction. The IL@Cys@PAN NFsM exhibits a rich array of functional groups and demonstrates strong binding affinity, fast mass transfer, and exceptional selectivity for sulfonamides (SAs) and Cu(II). The maximum adsorption capacities for SAs and Cu(II) in single-component systems were 122.3 and 97.4 mg/g respectively, according to the Langmuir isotherm model. The time dependent adsorption capacities followed a pseudo-second-order kinetic model, demonstrating a chemisorption-dominant process for each analyte. In binary pollutant systems, the co-occurrence of SAs and Cu(II) in water produced a competitive effect; however, the decrease in adsorption capacity was minimal. Through experimental analysis, FTIR characterization and density functional theory (DFT) studies, reasonable interactions of hydrogen-bond, electrostatic interactions, π-π stacking for SAs, and chelation effect for Cu(II) were proposed. Additionally, the reusability and recyclability of IL@Cys@PAN NFsM enhance its practicality for real-world applications. This paper presents the first systematic study on the simultaneous adsorption of heavy metals and antibiotics using NFsM, offering a novel perspective on the design of custom adsorbents capable of efficiently removing multiple contaminants with diverse characteristics while balancing eco-friendliness, excellent adsorption performance, and impressive recyclability for wastewater remediation.

Distribution of tetracyclines and sulfonamides resistance genes around a smallholder pig farm: Modeling and attribution

Livestock farm is a major source of antibiotics and antibiotic resistance genes (ARGs) pollution. ARGs can directly enter the environment through runoff and air deposition. The impact extent and the driving factors require further investigation to inform effective policies and actions to mitigate their spread. This study investigated a smallholder pig farm and its surrounding areas to understand the spread of ARGs. Topsoil samples were collected from 56 different sites within one kilometer of the farm, and a comprehensive analysis was conducted to reveal effects of soil properties, antibiotic residues, microbiome, mobilome on the variation of typical ARGs. The results confirmed that the ARGs reduced exponentially with increasing distance from the farm, with a goodness of fit (R2) of 0.7 for total ARGs. For tetracyclines (TC) and sulfonamides (SA) resistance genes, the fitting R2 exceeded 0.9. Model estimates allowed for quantitative comparisons of in-farm increments, out-farm background levels, and spread abilities of ARGs with distinct resistance mechanisms. SA-specific resistance genes (SRGs, 0.097 copies/16S rRNA gene) and TC-specific resistance genes (TRGs, 0.036 copies/16S rRNA gene) showed higher within-farm increases compared to multidrug resistance genes (MDRGs, 0.020 copies/16S rRNA gene). MDRGs, however, had a higher background level and a greater impact distance (0.18 km, 4.4 times the farm radius). Additionally spread abilities of TRGs varied by resistance mechanism, with ribosome protection proteins showing greater spread than TC inactivating enzymes and TC efflux pumps, likely due to different fitness costs. Correlation analysis and structural equation modeling indicated that changes in bacterial community composition and mobilome are primary factors influencing ARGs variation during their spread. Abiotic factors like soil nutrients and antibiotics also selectively enriched ARGs within the farm. These findings provide insights into the ARGs dissemination and could inform strategies to prevent their spread from smallholder livestock farms.

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.

Functional metagenomics highlights varied infection states with dynamics of pathogens and antibiotic resistance in lower respiratory tract infections

BackgroundAntimicrobial resistance (AMR) amongst pathogenic bacterial species poses significant challenges in treating infections of the lower respiratory tract (LRT), leading to higher hospitalization and mortality rates. MethodsBronchoalveolar lavage fluid (BALF) from 84 clinically adjudicated LRTI patients were subjected to respiratory pathogen ID/AMR (RPIP) enrichment and sequencing followed by Explify and CZID seq data analysis to identify potential LRTI pathogens and associated AMR genes. Patients were categorized as LRTI-WP (with pneumonia) and LRTI-WoP (without pneumonia). FindingsmNGS achieved 100 % pathogen detection compared to 73 % through clinician-used BioFire panel. Predominant pathogens included Acinetobacter baumannii, Klebsiella pneumoniae along with detection of Aspergillus versicolor and Herpes simplex virus. Double and polymicrobial infections were captured, involving non-respiratory pathogens like Rothia mucilaginosa, Escherichia coli, and Moraxella osloensis. AMR detection highlighted macrolide (MPH; ERM) and Sulfonamide (SUL) rich resistome in 60 % of patients followed by extended spectrum beta lactamase (OXA) and tetracycline (TET). LRTI-WP showed high abundance of A. baumannii, majorly associated with MPH whereas K. pneumoniae with beta-lactams was comparable in both groups. Differences in clinical severity may stem from non-respiratory pathogens, newly recognized via mNGS. CZID seq pipeline validated and revealed additional microbes and AMR genes in the cohort. InterpretationThe prevalence of common pathogens like A. baumannii and K. pneumoniae along with the non-respiratory pathogens identified by RPIP-Explify and CZID seq provided an understanding to evaluate the LRTI. mNGS is crucial for precise pathogen and antibiotic resistance detection, vital for combating antibiotic resistance.

Occurrence and risk assessment of quinolones and sulfonamides in freshwater aquaculture ponds in Northeast Zhejiang, China

Antibiotics play an essential role in the aquaculture industry, but their overuse and weak degradability inevitably lead to light to severe residues in natural and aquaculture environments. Most studies were interested in the occurrence, distribution, and ecological risks of a limited number of antibiotics in natural environments (rivers, lakes, and coastal regions) with a minor focus on antibiotic presence in either water, sediments, or organisms in aquaculture environments located in specific regions. In this study, we conducted a comprehensive investigation into the occurrence and distribution of up to 32 antibiotics [including 15 quinolones (QNs) and 17 sulfonamides (SAs)] in organisms and their corresponding environmental matrices from 26 freshwater aquaculture ponds in Northeast Zhejiang, China. A total of 13, 9, 7, and 7 antibiotics were detected in pond water, sediments, feeds, and aquaculture organisms, respectively, with concentration ranges of 0.6–92.2 ng/L, 0.4–1169.3 ng/g dw, <LOD–17.5 ng/g dw, and < LOD–234.3 ng/g ww, respectively, where enrofloxacin (ENR) was the main component in different matrix samples, with a proportion range of 51 %–88 %. There were differences in the predominant antibiotic and concentration abundance among fishponds, shrimp ponds, crab ponds, and turtle ponds. Feed was likely one of the most essential source of antibiotics in freshwater aquaculture ponds. The risk quotient (RQ) results revealed that ciprofloxacin (CIP) and ENR showed high risks to algae in water at the maximum measured concentrations and norfloxacin (NOR), CIP, ENR, and ofloxacin (OFL) exhibited high risks in sediments. However, the joint probability curve (JPC) showed acceptable risk in water. On the basis of the calculated hazard quotients (HQ < 1), the risk of human antibiotic ingestion through aquaculture organisms was acceptable. These results suggest that the rational control of antibiotic use is necessary for human health and ecological security.

Development of new methods for Determination of Sulpha Drugs with N-Chlorosacchrin Reagent

Sulpha drugs (sulphanilamide and their derivatives) are widely used as antibacterial drugs. An accurate and rapid method for quantitative determination of sulpha drugs and sulphanilamide would be of great importance. In literature several methods have been discussed for determination of sulphanilamide. The previous methods upon the evaluation of their nitrogen and sulphur contents while the latter were based upon the reaction of functional groups present in them.

Tunable morphology of Ce-organic framework for efficient removal of sulfamethazine and sulphanilamide

Discharging of “sulfa drugs” as a type of antibiotics in the wastewater, causes dangerous pollution impact for the aquatic system. Subsequently, the treatment of wastewater from “sulfa drugs” is interestingly required. Herein, removal of “sulfamethazine” and “sulfanilamide” as “sulfa drugs” from aqueous media was investigated by Ce-MOF with different morphologies. Ce-benzene tri-carboxylic acid “Ce-BTC” was synthesized by solvo-thermal, microwave and cold precipitation techniques to produce “Ce-BTC” (s) with straw-sheaf like structure, “Ce-BTC” (m) with spherical shaped particles and “Ce-BTC” (p) with orthorhombic structure, respectively. The effect of “Ce-BTC” morphology on the adsorption of “sulfamethazine” and “sulfanilamide” was kinetically and isothermally studied. The adsorption capacity for sulfamethazine was quite higher than that of sulfanilamide and “Ce-BTC” (m) with the spherical shape exhibited the highest adsorption capacity. The measured maximum capacity onto “Ce-BTC” (m) was 171.6 mg/g for sulfamethazine and 132.9 mg/g for sulphanilamide. The maximum capacity of “sulfamethazine” and “sulfanilamide” onto “Ce-BTC” (m) was quite higher than that onto “Ce-BTC” (s) by factor of 1.6 and 1.8, respectively. The prepared “Ce-BTC” (s) showed substantially good recyclability, while the removal efficiency is lowered by 15 % and 26 % for sulfamethazine and sulphanilamide, respectively, after 5 consecutive cycles.

Deciphering the degradation of sulfonamides by UV/chlorination in aqueous solution: kinetics, reaction pathways, and toxicological evolution

UV/Cl is a cost-effective process and is often used in municipal water treatment plants as well as in industrial applications. UV/Cl method is found highly effective in degrading contaminants, including pathogens, The conventional methods for water treatment have been proven inefficient for the complete elimination of pollutants and generate harmful by-products in the environment. This study evaluated the efficacy of three different treatment methods, chlorination alone, UV photolysis, and UV/Cl, for the degradation of sulfonamides (SAs) in water. The results highlighted that UV/Cl treatment was an efficient method for enhancing the degradation of sulfisoxazole (SFX), sulfadimethoxine (SAT), and sulfaguanidine (SG), with substrates degrading in 5, 6.5, and 4 min. The study also investigated the reactive species generated in the UV/Cl system and found that ·OH was the species responsible for the elimination of SFX. Additionally, the study explored the intermediate products generated during the degradation of SFX under the UV/Cl system, identifying VI distinct degradation pathways. The presence of ·OH radicals significantly enhanced the degradation of SFX, while some chlorine species also contributed to the degradation. The study predicted the toxicity of degradation products from the UV/Cl system using the ECOSAR (Ecological Structure Activity Relationships) program and found that the final degradation products of SFX were non-toxic, but concerns were raised about acute toxicity.

Occurrence, Source Apportionment, and Risk Assessment of Antibiotics in Mangrove Sediments from the Lianzhou Bay, China.

In recent years, the widespread application of antibiotics has raised global concerns, posing a severe threat to ecological health. In this study, the occurrence, source, and ecological risks of 39 antibiotics belonging to 5 classes in mangrove sediments from Lianzhou Bay, China, were assessed. The total concentrations of the antibiotics (∑39 antibiotics) ranged from 65.45 to 202.24 ng/g dry weight (dw), with an average of 142.73 ± 36.76 ng/g dw. The concentrations of these five classes of antibiotics were as follows: Sulfonamides (SAs) > Tetracyclines (TCs) > Fluoroquinolones (QUs) > Penicillin (PCs) > Macrolides (MLs). The spatial distribution of antibiotics varied as high tidal zone > middle tidal zone > low tidal zone. The total organic carbon (TOC), pH, nitrate (NO3--N), and nitrite (NO2--N) of the sediment significantly influenced the distribution of antibiotics (p < 0.05). A source analysis identified untreated sewage from aquaculture as the primary source of antibiotics in the local mangrove. A risk assessment revealed that ciprofloxacin, norfloxacin, ofloxacin of QUs, and tetracycline of TCs exhibited medium risks to algae in certain sampling sites, while other antibiotics exhibited low or no risks to all organisms. Nevertheless, the total risk of all the detected antibiotics to algae was medium in 95% of the sites. The overall ecological risk level of antibiotics in the middle tidal zone was slightly lower than in the high tidal zone and the lowest in the low tidal zone. In summary, the experimental results provided insights into the fate and transport behaviors of antibiotics in mangrove sediments from Lianzhou Bay.

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.

The Use and Assessment of Vetom-15.1 in the Treatment and Prevention of Dyspepsia in Newborn Calves

Treatments for dyspepsia, which is commonly used in newborn calves in livestock production, rely on the use of antibiotics. Examples of this: sulfonamide, nitrofuran and other synthetic drugs. The use of these drugs does not always give positive results. With prolonged and unjustified systematic use of antibiotics, especially on farms, the therapeutic result is ineffective due to the fact that most microorganisms adapt to them. Antibiotics, together with pathogens of intestinal infections, suppress that part of the microflora that normally performs protective functions and do not allow beneficial microflora to colonize growths inside the intestines. When treatment is aimed at destroying pathogens, normal microflora is destroyed, which leads to the development of dysbacteriosis and negatively affects the development of immunobiological reactivity in the body of young animals, which is manifested in their clinical status. The studies conducted examined the development of new safe modern methods of treating young animals and the therapeutic effect of new medicinal substances.