Search Results (448)

The presence of ciprofloxacin antibiotic in water is a threat to humans and aquatic life since antibiotics are currently regarded as emerging contaminants of major concern. This work reported the use of Nexar^TM film, a sulfonated pentablock copolymer, to effectively remove ciprofloxacin antibiotic from water in a sustainable approach. The removal efficiency of Nexar film was evaluated in aqueous or salty (NaCl 0.5 M) ciprofloxacin solutions as a function of contact time and the initial ciprofloxacin concentration. In the investigated conditions, the polymeric film totally removed ciprofloxacin in MilliQ solution while its removal efficiency in salty solution was approximately 73%. This lower value is due to the presence of Na⁺ ions that compete with antibiotic molecules for adsorption on active surface sites of the polymeric film. No further release of adsorbed antibiotic molecules occurred. The kinetic studies, conducted for ciprofloxacin adsorption on Nexar film in both MilliQ and salty solutions, revealed that the overall sorption process is controlled by the rate of surface reaction between ciprofloxacin molecules and active sites on Nexar surface. Furthermore, at equilibrium conditions, the isotherm model that best fits experimental parameters was not linear. This indicates that the competition between the solute and the solvent for binding sites on the adsorbent should be considered to describe adsorption processes in both MilliQ and salty solutions. Full article

The removal of antibiotics from aqueous media along with their recovery is still an open research topic, due to their practical and economical importance. Adsorption allows these two objectives to be achieved, provided that the adsorbent used is chemically and mechanically stable and has a low preparation cost. In this study, PET (polyethylene terephthalate) fibers, obtained by mechanically processing PET waste, were used for the adsorption of rifampicin (RIF) and rifaximin (RIX) antibiotics from aqueous media. The experimental adsorption capacity of PET fibers for the two antibiotics (RIF and RIX) was determined at different pH values (2.0–6.5), adsorbent dose (0.4–20.0 g/L), contact time (5–1440 min), initial antibiotic concentration (4.0–67.0 mg/L), and temperature (10, 22, and 50 °C); the experimental values of these parameters were analyzed using a neuro-evolutive technique (ANE) combining sequential deep learning (DL) models with a differential evolution algorithm. The obtained optimal ANN-DL algorithm was then used to obtain the optimal models for the adsorption of RIF and RIX on PET fibers, which should adequately describe the adsorption dynamics for both antibiotics. The adsorption processes are spontaneous and endothermic (ΔG < 0, ΔH > 0) and are described by the Langmuir model (R² > 0.97) and the pseudo-second order kinetic model (R² > 0.99). The retention of RIF and RIX on the surface of PET fibers occurs through physicochemical interactions, and the FTIR spectra and microscopic images support this hypothesis. The presence of inorganic anions in the aqueous solution leads to an increase in the adsorption capacities of RIF (max. 7.6 mg/g) and RIX (max. 3.6 mg/g) on PET fibers, which is mainly due to the ordering of water molecules in the solution. The experimental results presented in this study allowed for the development of the adsorption mechanism of RIF and RIX on PET fibers, highlighting the potential practical applications of these adsorption processes. Full article

Previous studies have mostly focused on the adsorption behavior of microplastics for antibiotics in soil or aqueous environments. This study explores the adsorption characteristics of microplastics for antibiotics under groundwater environmental conditions and the influence of typical influencing factors of the groundwater environment (pH, pollutant concentration, aquifer media, dissolved organic matter, and ionic strength) on the adsorption process. Polyethylene (PE) and tetracycline (TC) were selected as typical microplastics and antibiotics in the experiment. The study results showed that the adsorption of TC by PE reached equilibrium at 48 h, and the adsorption kinetics fitted pseudo-second-order kinetics models well. The adsorption isotherm was consistent with the Langmuir model. The adsorption capacity of PE for TC was highest under neutral conditions and positively correlated with the initial concentration of TC. The aquifer media exhibited limited effects on the adsorption process. Fulvic acid (FA) significantly suppressed TC adsorption onto PE, attributable to competitive adsorption mechanisms. TC adsorption on PE initially increased then declined with Ca²⁺ concentration due to Ca²⁺ bridging and competition. This research elucidates the adsorption mechanisms of PE towards TC, providing theoretical basis and reference for assessing the environmental risk of microplastics and antibiotics in groundwater. Full article

Global antibiotic use saturates ecosystems with selective pressure, driving mobile genetic element (MGE)-mediated antibiotic resistance gene (ARG) dissemination that destabilizes ecological integrity and breaches public health defenses. This review synthesizes the sources, environmental distribution, and ecological risks of antibiotics and ARGs, emphasizing the mechanisms of horizontal gene transfer (HGT) driven by MGEs such as plasmids, transposons, and integrons. We further conduct a comparative critical analysis of the effectiveness and limitations of antibiotics and ARGs remediation strategies for adsorption (biochar, activated carbon, carbon nanotubes), chemical degradation (advanced oxidation processes, Fenton-based systems), and biological treatment (microbial degradation, constructed wetlands). To effectively curb the spread of antimicrobial resistance and safeguard the sustainability of ecosystems, we propose an integrated “One Health” framework encompassing enhanced global surveillance (antibiotic residues and ARGs dissemination) as well as public education. Full article

Phage therapy shows promise as an adjunct to antibiotics for treating Staphylococcus aureus infections. We previously reported a combined flucloxacillin/two-phage cocktail treatment selected for resistance to podovirus phage 66 in a rodent model of methicillin-susceptible S. aureus (MSSA) endocarditis. Here we show that resistant clones harbor mutations in tarS, which encodes a glycosyltransferase essential for β-GlcNAcylation of wall teichoic acid (WTA). This WTA modification has been described in vitro as critical for podoviruses adsorption. Transcriptomics confirmed continued tarS expression in resistant clones, supporting a loss-of-function mechanism. Accordingly, phage 66 binding and killing were restored by WT tarS complementation. In addition, we investigated the counterintuitive innate susceptibility to phage 66 of the tarM + Laus102 strain used in the endocarditis model. We show that it likely results from a significant lower tarM expression, in contrast to the innate resistant strain RN4220. Our findings demonstrate that tarS-mediated WTA β-GlcNAcylation is critical for podovirus infection also in vivo and identify tarM transcriptional defect as a new mechanism of podoviruses susceptibility in S. aureus. Moreover, and since tarS disruption has been previously shown to enhance β-lactam susceptibility, our results support the development of combined podovirus/antibiotic strategies for the management of MRSA infections. Full article

Water environments and sediments are important reservoirs for antibiotic resistance genes (ARGs). Under the pressure of antibiotics, ARGs can transform between microorganisms. Lanthanum-modified bentonite (LMB) is a phosphorus passivation material with good prospects in water environment restoration. After a treatment with LMB, the phosphorus forms in water and sediments will change, which may have an impact on microorganisms and the transmission of ARGs. To investigate the effects of LMB and antibiotics on ARGs and bacterial communities in sediment and aquatic environments, LMB and tetracycline (Tet) were added individually and in combination to mixed samples of sediment and water. The results showed that the addition of either LMB or Tet increased the abundance of intI1 and tetA genes in both the sediment and water, with the Tet addition increasing ARGs to more than 1.5 times the abundance in the control group. However, when LMB and Tet were present simultaneously, the abundance of ARGs showed no significant difference compared to the control group. Tet and LMB also affected the bacterial community structure and function in the samples and had different effects on the sediment and water. A correlation analysis revealed that the potential host bacteria of the intI1 and tetA genes were unclassified_Geobacteraceae, Geothrix, Flavobacterium, Anaeromyxobacter, and Geothermobacter. These findings indicate that Tet or LMB may increase the dissemination of ARGs by affecting microbial communities, while LMB may reduce the impact of Tet through adsorption, providing a reference for the safety of the LMB application in the environment and its other effects (alleviating antibiotic pollution) in addition to phosphorus removal. Full article

Every year, a large amount of antibiotics enter aquatic environments globally through discharging of pharmaceutical wastewater and domestic sewage, emissions from agriculture, and livestock, posing a severe threat to ecosystems and human health. Therefore, it is essential to develop efficient adsorption materials for rapid removal of antibiotics in water. In this study, abundant and renewable wetland plants (lotus leaves, Arundo donax, and canna lilies) were utilized as raw materials to prepare biochar through slow pyrolysis combined with KOH chemical activation. The prepared biochar was employed to adsorb typical tetracycline (TC) antibiotics (TC-HCl, CTC-HCl, OTC-HCl) from water. The results showed that the optimum biochar (LBC-600 (1:3)) was prepared at a pyrolysis temperature of 600 °C with the mass ratio of KOH to lotus leaf of 1:3. The optimum pH for the adsorption of the three antibiotics were 5, 4, and 3, respectively. The highest adsorption rates reached 93.32%, 81.44%, and 83.76% for TC-HCl, CTC-HCl, and OTC-HCl with 0.6 g/L of biochar, respectively. At an initial antibiotic concentration of 80 mg·L⁻¹, the maximum adsorption capacities achieved 40.17, 27.76, and 24.6 mg·g⁻¹ for TC-HCl, CTC-HCl, and OTC-HCl, respectively. The adsorption process conformed to the pseudo-second-order kinetic and Langmuir isotherm models, indicating that it was a spontaneous endothermic process and primarily involved monolayer chemical adsorption. This study transformed wetland plant waste into adsorbent and applied it for antibiotic removal, providing a valuable resource utilization strategy and technical support for recycling wetland plant residues and antibiotic removal from water environments. Full article

The use of widespread and inexpensive clay minerals as adsorptive agents, as well as materials obtained by their chemical modification, can contribute to the solution of the problem of environmental pollution with antibiotics. This review considers the structural features of various natural clay minerals and the effect of these features on their sorption capacity. Based on the analysis of available papers (over the last 15 years, also including some fundamental basics over the last 20–30 years), it has been established that the main property of an antibiotic molecule affecting the ability to be adsorbed by a clay mineral is the hydrophilicity of the organic substance molecule. The leading properties that determine the ability of clays to adsorb antibiotics are the charge and area of their surfaces. The ability of antibiotic molecules to protonate and a partial change in the edge charge of mineral layers is determined by the acidity of the sorption solution. In addition, empirical evidence is provided that the most important factors affecting adsorption are the ionic strength of the sorption solution, the concentration of the adsorbent and adsorbate, and the interaction temperature. The diversity of the composition, structure, and properties of clay minerals allows them to be effective sorbents for a wide range of antibiotics. Full article

The increasing prevalence of multidrug-resistant (MDR) bacterial infections necessitates the exploration of alternative antimicrobial strategies, with phage therapy emerging as a viable option. However, the effectiveness of naturally occurring phages can be significantly limited by bacterial defense systems that include adsorption blocking, restriction–modification, CRISPR-Cas immunity, abortive infection, and NAD+ depletion defense systems. This review examines these bacterial defenses and their implications for phage therapy, while highlighting the potential of phages’ bioengineering to overcome these barriers. By leveraging synthetic biology, genetically engineered phages can be tailored to evade bacterial immunity through such modifications as receptor-binding protein engineering, anti-CRISPR gene incorporation, methylation pattern alterations, and enzymatic degradation of bacterial protective barriers. “Armed phages”, enhanced with antimicrobial peptides, CRISPR-based genome-editing tools, or immune-modulating factors, offer a novel therapeutic avenue. Clinical trials of bioengineered phages, currently SNIPR001 and LBP-EC01, showcase their potential to safely and effectively combat MDR infections. SNIPR001 has completed a Phase I clinical trial evaluating safety in healthy volunteers, while LBP-EC01 is in Phase II trials assessing its performance in the treatment of Escherichia coli-induced urinary tract infections in patients with a history of drug-resistant infections. As “armed phages” progress toward clinical application, they hold great promise for precision-targeted antimicrobial therapies and represent a critical innovation in addressing the global antibiotic resistance crisis. Full article

In the process of chicken breeding, there has been a great deal of abuse of antibiotics. Antibiotics can enter the human body along with the chicken meat, comprising a possible risk to human health. In this paper, principal component analysis (PCA)–linear discriminant analysis (LDA) was chosen to classify neomycin (NEO) and chloramphenicol (CAP) residues in chicken meat. A total of 400 chicken meat samples were used for the classification, of which 268 samples and 132 samples were used as the training sets and the test sets, respectively. The experimental condition of SERS spectrum collection was optimized, including the use of a gold colloid and active agent, and an improvement in the adsorption time. The optimal measurement conditions for the SERS spectra were an adsorption time of 4 min and the use of a 14th-generation gold colloid as the enhanced substrate without a surfactant. For three groups of different spectral preprocessing methods, the classification accuracies of PCA-LDA models for test sets were 78.79% for baseline correction, 84.85% for the second derivative and 100% for the second derivative combined with baseline correction. LDA was used to establish a classification model to realize the quick determination of NEO and CAP residues in chicken meat by SERS. The results showed that the characteristic peaks at 546 and 666 cm⁻¹ could be used to distinguish NEO and CAP residues in chicken meat. The classification model based on PCA-LDA had higher classification accuracy, sensitivity and specificity using a second derivative combined with baseline correction as the spectral preprocessing method, which shows that the SERS method based on PCA-LDA could be used to perform the classification of NEO and CAP residues in chicken meat quickly and effectively. It also verified the feasibility of PCA-LDA to effectively classify chicken meat samples into four types. This research method could provide a reference for the measurement of such antibiotic residues in chicken meat in the future. Full article

Lakes are important sinks for antibiotics as suspended particulate matters (SPMs) in lakes have become significant carriers of antibiotic adsorption and migration. The light and heavy fractions of SPM are involved in the process of suspension and sedimentation in the aqueous environment. Combined with the adsorption behaviors of antibiotics onto SPM, a basis for the risk of antibiotic migration in lakes will be provided. In this study, SPM from Lake Taihu was collected and grouped according to density as light fraction (LF) and heavy fraction (HF), with heavy fraction including loosely bound humus (WLH) and tightly bound humus (TH). Adsorption studies were carried out with three typical antibiotics: tetracycline hydrochloride (TC), norfloxacin (NOR), and trimethoprim (TMP). The adsorption processes of all particulate fractions towards antibiotics were fast, which is consistent with pseudo-second-order kinetics. The adsorption in the TC and NOR groups was much higher than that in the TMP group, which was mainly related to the properties of the antibiotics. The LF group was the special component with the fastest adsorption rate, the largest adsorption amount, and the lowest desorption ratio, regardless of antibiotics, which is related to the organic matter content and the rich-carbon-containing functional groups in the LF group, such as -C=O. These findings highlight the need for further attention to the high adsorptive transport effect of LF on antibiotics in lake ecosystems. Full article

This study reports the synthesis, structural characterization, adsorption studies, nanoscale interaction, and photocatalytic application of pure and Fe-doped ZnS quantum dots for the degradation of the antibiotic cefalexin in aqueous solution. Nanoparticles were synthesized via the microwave-assisted method, and Fe doping was introduced at a 1% molar ratio. HRTEM images confirmed quasi-spherical morphology and high crystallinity, with particle sizes averaging 2.4 nm (pure) and 3.5 nm (doped). XRD analysis showed a consistent cubic ZnS structure. UV-vis spectra showed strong absorption at 316 nm for both samples, and PL measurements revealed emission quenching upon Fe doping. Photocatalytic tests under UV light demonstrated significantly higher degradation rates of 10 ppm cefalexin with Fe-doped ZnS, reaching near-complete removal within 90 min. Adsorption experiments revealed higher affinity and adsorption capacity of Fe-doped ZnS toward cefalexin compared to pure ZnS, as demonstrated by the Freundlich isotherm analyses, contributing significantly to enhanced photocatalytic degradation performance. High-resolution QTOF LC-MS analysis confirmed the breakdown of the β-lactam and thiazolidine rings of cefalexin and the formation of low-mass degradation products, including fragments at m/z 122.0371, 116.0937, and 318.2241. These findings provide strong evidence for the structural destruction of the antibiotic and validate the enhanced photocatalytic performance of Fe-doped ZnS. Full article

Background/Objectives: Antibiotic contamination in water sources is a growing global concern, contributing to environmental degradation and the proliferation of antimicrobial resistance. Traditional treatment methods, such as advanced oxidation or high-pressure membrane processes, are often energy-intensive and economically unsustainable for large-scale or decentralized applications. This study explores the potential of two cost-effective, commercially available metal–organic frameworks (MOFs), ZIF-8 and F300, to improve the performance of membrane-based filtration–adsorption systems for removing tetracycline and sulfadiazine from water. Methods: Batch adsorption experiments were performed to evaluate the uptake capacities, kinetics, and isotherms of both MOFs toward the selected antibiotics. The membranes were modified using a low-cost silane-assisted deposition of MOF particles and tested in a microfiltration system. Removal efficiencies and water permeability were assessed and kinetic and isotherm models were applied to understand the adsorption mechanisms. Results: ZIF-8 showed superior adsorption performance, with maximum capacities of 442.2 mg/g for tetracycline and 219.3 mg/g for sulfadiazine. F300 was effective only for tetracycline. Membranes modified with ZIF-8 improved pharmaceutical removal by 187% (tetracycline) and 224% (sulfadiazine) compared to unmodified membranes. Although permeability decreased due to increased hydrophobicity, the materials and processes remained economically favorable. Conclusions: This study demonstrates that MOF-modified ceramic membranes, particularly those incorporating ZIF-8, offer a low-cost, scalable, and energy-efficient alternative for pharmaceutical removal from water. The approach combines strong environmental impact with economic viability, making it attractive for broader implementation in water treatment systems. Full article

Activated carbon is widely recognized as an effective material for removing pollutants, especially pharmaceutical residues, from water. In this study, high-surface-area activated carbon derived from rice husks (RHAC) was synthesized via KOH activation and used for the adsorption of ciprofloxacin, a widely used fluoroquinolone antibiotic. Its adsorption behavior was systematically investigated through batch experiments varying the pH, adsorbent dosage, contact time, initial concentration, and temperature. The RHAC exhibited a high surface area of 1539.7 m²/g and achieved a maximum adsorption capacity of 398.4 mg·g⁻¹. The Freundlich isotherm best describes its adsorption equilibrium, suggesting multilayer adsorption on a heterogeneous surface. Kinetic modeling revealed that the adsorption process followed a pseudo second-order model (R² = 0.9981), indicating chemisorption as the rate-limiting mechanism. Thermodynamic parameters (ΔH° = 6.61 kJ/mol, ΔG° < 0) confirmed that the process was endothermic and spontaneous. These findings demonstrate that RHAC is a highly efficient, low-cost, and sustainable adsorbent for removing ciprofloxacin from aqueous environments. Full article

Antibiotic resistance has been recognized as a global threat to human health. Therefore, it is urgent to develop effective strategies to address the contamination of water environments caused by antibiotics. In this study, Fe/Mn bimetallic-modified biochar (FMBC) was synthesized through a one-pot oxidation/reduction-hydrothermal co-precipitation method, demonstrating an exceptional photocatalytic-Fenton degradation performance for oxytetracycline (OTC). Characterization techniques including FTIR, SEM, XRD, VSM, and N₂ adsorption–desorption analysis confirmed that the Fe/Mn bimetals were successfully loaded onto the surface of biochar in the form of Fe₃O₄ and MnFe₂O₄ mixed crystals and exhibited favorable paramagnetic properties that facilitate magnetic recovery. A key innovation is the utilization of biochar’s inherent phenol/quinone structures as reactive sites and electron transfer mediators, which synergistically interact with the loaded bimetallic oxides to significantly enhance the generation of highly reactive ·OH radicals, thereby boosting catalytic activity. Even after five recycling cycles, the material exhibited minimal changes in degradation efficiency and bimetallic crystal structure, indicating its notable stability and reusability. The photocatalytic degradation experiment conducted in a Fenton-like reaction system demonstrates that, under the conditions of pH 4.0, a H₂O₂ concentration of 5.16 mmol/L, a catalyst dosage of 0.20 g/L, and an OTC concentration of 100 mg/L, the optimal degradation efficiency of 98.3% can be achieved. Additionally, the pseudo-first-order kinetic rate constant was determined to be 4.88 min⁻¹. Furthermore, this study elucidated the detailed degradation mechanisms, pathways, and the influence of various ions, providing valuable theoretical insights and technical support for the degradation of antibiotics in real wastewater. Full article