Search Results (245)

Back-mixing has been widely applied during practical composting to initiate the process and improve compost product quality. However, for antibiotic mycelial residue (AMR), a fermentation by-product containing residual antibiotics, the ecological safety of this treatment remains unclear. In this study, pleuromutilin mycelial residue (PMR) was subjected to a 35-day aerobic composting experiment with a back-mixing treatment (T group) and the conventional composting group (CK group) to evaluate composting performance and antibiotic resistance risk. The results demonstrated that the T group exhibited more rapid heating and a higher degree of humification. Additionally, the T group not only exhibited faster pleuromutilin degradation, reaching below the detection limit 3 days earlier than in the CK group, but also achieved up to a 3.1-fold reduction in antibiotic resistance genes (ARGs) and a 93.2% overall reduction in mobile genetic elements (MGEs). Redundancy analysis (RDA), variance partitioning analysis (VPA), and co-occurrence network analysis indicated that microbial community structure appeared to be more strongly associated with ARG variation than MGEs under the tested conditions. Overall, back-mixing accelerated pleuromutilin degradation and enhanced PMR composting performance, while no substantial enrichment of the detected ARGs was observed under the tested composting conditions. This study provides a scientific basis for the safe resource utilization of AMR. Full article

The widespread use of antibacterial agents in livestock production is associated with antibiotic residues in animal products and feed, posing a potential threat to food safety and contributing to antimicrobial resistance. The aim of this study was to assess contamination levels of beef, pork, and feed with antibiotic residues in the Kostanay region. The results demonstrated the presence of antibiotic residues in beef, pork, and feed, while all detected concentrations remained below established maximum residue limits. Despite compliance with regulatory standards, residues were detected frequently, and their levels differed significantly depending on feed type (p < 0.001). Microbiological analysis confirmed the presence of Escherichia coli and Staphylococcus aureus in meat samples, with isolates exhibiting moderate to high antimicrobial resistance, particularly in pork. The highest resistance was observed to tetracycline, streptomycin, and thiamphenicol. The obtained data indicate that even trace antibiotic concentrations entering the “feed–animal–product” chain may be associated with selective pressure on microbiota and the circulation of resistant microorganisms. The results highlight the need for comprehensive monitoring of feed and animal products to assess and mitigate antimicrobial resistance spread within the food chain. Full article

Background/Objectives: Residues of β-lactam antibiotics in foods of animal origin are important for official residue control and public-health risk assessment. Sample storage conditions may affect the measured concentrations of these analytes, whereas cooking may influence consumer exposure. This study evaluated the stability of six β-lactam antibiotics—amoxicillin, ampicillin, phenoxymethylpenicillin, benzylpenicillin, cefazolin, and cefotaxime—and clavulanic acid, a β-lactamase inhibitor, in chicken meat during storage and thermal processing. Methods: Incurred chicken meat samples were obtained after in vivo administration of the studied compounds. Stability was assessed during storage at +4 °C, −20 °C, and −86 °C for up to 165 days, during repeated freeze–thaw handling, and during heating at 100 °C for up to 30 min. The target compounds were quantified by HPLC–MS/MS after acetonitrile extraction and hexane clean-up. Results: The studied compounds were unstable at +4 °C, with concentrations decreasing below the detection limit within 3–27 days depending on the compound. Storage at −20 °C was insufficient for long-term preservation of most penicillins, whereas −86 °C improved stability. Cefazolin was the most stable compound under the tested storage conditions, while cefotaxime was the least stable. Heating at 100 °C for 30 min caused substantial reduction in parent-compound concentrations, ranging from 63.8 ± 4.0% for cefazolin to complete disappearance below the detection limit for cefotaxime. Conclusions: For reliable official residue analysis, chicken meat samples intended for β-lactam testing should be stored at −86 °C whenever long-term storage is required. Repeated thawing should be avoided. Cooking substantially reduces the concentrations of the parent compounds but cannot be considered a reliable safety measure, because degradation may be incomplete and degradation products were not assessed in this study. Full article

Aquaculture sediments are increasingly recognized as important reservoirs of antibiotic resistance genes (ARGs). Although thermophilic fermentation is widely used to reduce ARGs and pathogens in manure, most biosafety assessments stop at the fertilizer product itself, leaving unresolved whether these benefits persist after application to aquaculture sediments. Here, we compared inorganic fertilizer (IF), raw manure (RM), and fermented fertilizer (FF) to test whether fermentation confers sustained biosafety benefits in aquaculture pond sediments. After a 6-month co-culture period, sediment samples were analyzed using shotgun metagenomic sequencing, ARG and mobile genetic element (MGE) profiling, antibiotic residue determination, and network analyses. Long-term fertilization significantly altered sediment physicochemical properties, microbial community composition, and resistome structure. Among the three groups, the RM exhibited the highest total ARG abundance and the greatest number of unique ARG subtypes, with significant enrichment of multidrug resistance genes as well as pathogen-, disease-, and host-associated mobile genetic elements (MGEs). In contrast, the FF group showed the lowest total ARG abundance and fewest unique ARG subtypes, along with suppression of pathogen-associated MGEs, indicating that FF can effectively reduce the risk of ARG dissemination. However, the potential impact of residual antibiotics still warrants attention. Redundancy analysis showed that TC and TN primarily explained bacteriome and resistome variation under RM, whereas pH, EC, AP, and AK were more strongly associated with FF. Co-occurrence analysis further suggested that fertilizer-driven microbial community shifts may regulate ARG persistence and potential cross-ecosystem dissemination. Overall, fermented fertilizer attenuated, but did not eliminate, manure-derived resistance risks in aquaculture sediments. These findings support fermented fertilizer as a safer management option than raw manure and highlight the need for integrated risk assessment combining ARGs, MGEs, microbial hosts, and antibiotic residues. Full article

This study isolated and characterized Lactiplantibacillus plantarum WYP from naturally fermented pineapple peel residues. The strain exhibited a potent in vitro histamine degradation rate of 78.63% and demonstrated multiple probiotic properties, including acid and bile salt tolerance, simulated gastrointestinal fluid resistance, antimicrobial activity against foodborne pathogens, and in vitro cholesterol-lowering ability. Whole-genome sequencing revealed a 3.34 Mb circular genome encoding 3200 genes. Genomic analysis elucidated a multidimensional “Prevention–Promotion–Utilization” (PPU) strategy for histamine regulation: prevention via the absence of histidine decarboxylase (hdc) genes; promotion of degradation via multicopper oxidase (e.g., cueO) and amine oxidase systems; and utilization through downstream aldehyde metabolism and redox homeostasis genes. Safety assessments confirmed the strain’s non-hemolytic nature, absence of harmful metabolite production, and no detectable risk of acquired antibiotic resistance gene transfer. The integration of phenotypic and genomic evidence positions LPWYP as a promising probiotic candidate for mitigating biogenic amines in fermented foods. Full article

Carbon quantum dots (CQDs) have attracted considerable attention as versatile fluorescent nanomaterials in the domains of food safety and preservation, primarily due to their tunable photoluminescence, high aqueous dispersibility, and favorable biocompatibility. Although numerous reviews have documented the synthesis and extensive applications of CQDs, a focused critical assessment specifically addressing how rational surface functionalization and heteroatom doping impact their performance within complex food matrices remains absent. This review provides a targeted analysis of the interplay between the functional design of CQDs, including both surface group engineering and elemental doping, and their practical efficacy in food-related applications. Initially, a concise overview of the fundamental aspects of CQDs relevant to their functionality is presented, emphasizing the origin and role of surface chemical groups and pivotal photophysical sensing mechanisms. Subsequently, the core of the review critically evaluates recent advancements (particularly those from 2022 onward) in the use of functionalized CQDs for detecting food contaminants (such as heavy metals, pesticide residues, antibiotic residues, pathogens, and additives) and in food preservation techniques, including active packaging, antioxidative and antimicrobial coatings, and photodynamic inactivation. Through a systematic comparison of analytical figures of merit and the effects of various matrices across different design approaches, we delineate both the established capabilities and the current limitations of CQD-based technologies in realistic food systems. The review concludes by identifying ongoing challenges, specifically, batch-to-batch consistency, the long-term safety profile of CQDs in food-contact applications, and the translation gap from laboratory innovation to industrial practice, and outlines prospective research directions. The overarching aim of this work is to provide a structured framework for understanding how deliberate functional design can lead to improved performance, thereby guiding the rational development of next-generation CQD-based materials for ensuring food quality and public health. Full article

The widespread presence of pharmaceutical residues, particularly emerging antibiotics such as levofloxacin (LVX) and amoxicillin (AMOX), in aquatic environments poses serious risks to ecosystems and public health. In this study, magnetically modified biochar was synthesized from orange peel waste and evaluated for the percentage removal of LVX and AMOX from synthetic wastewater. The biochar was chemically modified with iron to enhance its adsorption capacity and facilitate magnetic separation. The physicochemical properties of raw and iron-modified biochar were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Batch adsorption experiments were conducted to investigate the effects of temperature, contact time, adsorbent dosage, pH, and initial antibiotic concentration on removal efficiency. Antibiotic concentrations were quantified using UV–Vis spectrophotometry. Batch adsorption experiments revealed that iron-modified biochar (FeMBC) significantly outperformed raw biochar (RBC) in antibiotic removal. Optimal removal efficiencies of 90% for AMOX and 92% for LVX were achieved at an adsorbent dosage of 0.1 g, antibiotic concentration of 10 mg L⁻¹, contact time of 120 min, and temperature of 30 °C. Equilibrium data were best described by the Langmuir isotherm model, indicating monolayer adsorption, with correlation coefficients of 0.98 for AMOX and 0.97 for LVX. Kinetic analysis showed that the pseudo-second-order model provided the best fit, suggesting that chemisorption dominated the adsorption process. Thermodynamic studies confirmed that the adsorption was spontaneous and exothermic. Overall, the results demonstrate that iron-modified orange peel biochar is an efficient (90% better removal efficiency than RBC), low-cost, and environmentally sustainable adsorbent for the removal of emerging antibiotics from pharmaceutical wastewater, offering strong potential for practical water treatment applications. Full article

Escherichia coli, a facultative anaerobic Gram-negative member of the Enterobacteriaceae, is an increasingly important opportunistic pathogen driven in part by rising resistance to clinically important antibiotics. Regulation of multidrug efflux systems by two-component signal transduction pathways, particularly the BaeSR system, plays a central role in this process. However, the functional residues governing signal transduction through the sensor kinase BaeS remain incompletely defined. In this study, we integrated domain prediction, homology-guided site-directed mutagenesis, in vitro protein purification, autophosphorylation assays, and reverse-transcription quantitative polymerase chain reaction (RT-qPCR)-based transcriptional analysis of selected BaeSR-regulated genes to delineate key residues required for BaeS function. Sequence analysis identified His250 as a candidate autophosphorylation site and Asn364 as a conserved residue within the catalytic domain. Biochemical characterization of purified wild-type BaeS and an H250A mutant demonstrated that His250 is indispensable for autophosphorylation. Consistently, RT-qPCR analysis showed that BaeS activation markedly induced the transcription of BaeSR-regulated efflux-associated genes, whereas genetic deletion of baeS or selective disruption of kinase activity by the N364A mutation abolished this response. Together, these findings establish His250 as a key residue for BaeS autophosphorylation and identify Asn364 as essential for inducible BaeSR signaling and activation of resistance-associated target genes, thereby establishing an experimental framework for elucidating BaeSR-mediated efflux regulation and informing future studies of resistance regulatory networks and potential intervention strategies centered on key signaling nodes. Full article

There is growing concern that antimicrobial use (AMU) in livestock may contribute to antimicrobial resistance (AMR) in humans and lead to the consumption of animal-derived foods contaminated with antimicrobial residues. As stakeholders in the livestock industry, farmers must participate in the joint effort to reduce AMU. This cross-sectional study, based on a survey questionnaire, was conducted to evaluate the biosafety measures implemented on small ruminant farms and to assess the knowledge, attitudes and practices (KAP) of small ruminant farmers regarding AMU, AMR and residues. The mean biosafety score obtained was 8.4 points on a 0–17 scale. Some biosafety measures appeared difficult to implement, namely vehicle disinfection, requiring visitors to change clothing and footwear at the farm entrance, cleaning and disinfecting farm facilities, using high-pressure washing equipment, and requiring employees to change clothing and footwear upon entering the farm. Although farmers self-reported moderate levels of knowledge (4.9 points on a 0–7 scale) and positive attitudes (5.8 points on a 0–7 scale), significant gaps in knowledge about antibiotics and antimicrobial stewardship persisted. Practices received lower scores (4.7 on a 0–7 scale), especially regarding medication recording, leftover antibiotic management, and waste disposal. Cluster analysis identified distinct farmer profiles with different patterns of knowledge and practices. These findings underscore the importance of considering farmer heterogeneity when designing interventions aimed at improving AMU. Full article

The increasing use of antibiotics around the globe has contributed to an increase in antimicrobial resistance and become a major risk to both public health and sustainable development. Reliable and fast detection of antibiotic residues in clinical, agricultural, and environmental matrices is required to monitor antimicrobial resistance effectively. The conventional analytical techniques are sensitive, but they are also expensive, complex and lacking in portability. Voltammetry is a recently emerging electrochemical detection technique that is low-cost and rapid. To the best of our knowledge, for the first time, a meta-analysis was conducted on graphene-based electrochemical sensors and biosensors for antibiotic detection over the last decade. This systematic review critically examines the analytical properties of sensors and biosensors, the physicochemical properties of antibiotics, adsorption characteristics, and the use of nanoparticles to improve the selectivity and sensitivity of devices. This review critically examines the cost-effectiveness, scalability, and practicality of point-of-use devices using graphene-based sensors and biosensors. This systematic review also discusses the potential risks to human health from antibiotic contamination and the role of monitoring in contributing to achieving the UN’s Sustainable Development Goals. This systematic review identifies a gap between developing sensors in laboratories versus their deployment as field-deployable devices; it highlights challenges associated with stability, matrix effects and the complexity of manufacturing devices. Finally, it provides recommendations for future research that may help to address this gap to promote the transition of innovative devices from academic to practical applications. Full article

Despite the undisputable ecosystem importance of honeybees, human activities have a substantial impact on their health. Since foraging is directly linked to a wide range of crops and bee-attracting flowers, plant protection products are at the forefront of chemical scrutiny, along with contamination of pollen, nectar, beehive components and water by other xenobiotics. In this study, a non-targeted Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS) screening was applied to 25 honeybee samples collected after reported death incidents in Greece. This approach led to the tentative annotation of over 50 compounds across various chemical classes, including pesticides, PFAS candidates not included in the EFSA “PFAS-4”, pharmaceuticals, antibiotics, industrial chemicals, and natural product constituents. In parallel, targeted pesticide residue analysis using liquid and gas chromatography coupled to tandem mass spectrometry (LC-MS/MS and GC-MS/MS) was performed, covering more than 250 active substances and providing direct quantitative results, revealing 11 active substances in concentrations ranging from <limit of quantification (LOQ) to 0.95 mg/kg, overlapping substantially with the HRMS detection. Overall, this study does not allow concrete causal attribution of mortality to specific chemicals; however, it documents complex co-occurrence patterns (pesticides together with other xenobiotics and plant bioactives), not excluding sublethal and mixture-toxicity effects. Quantified pesticide concentrations were below acute LD50-based thresholds, yet selected samples combined neonicotinoid/pyrethroid/fungicide signatures and other contaminants, supporting the need for mixture-toxicity frameworks and effect-based follow-ups. Full article

Agroindustrial residues represent an abundant and underutilized source of carbon-rich materials for environmental remediation. In this study, annatto processing waste (Bixa orellana), a largely unexplored lignocellulosic by-product generated during pigment extraction, was converted into hydrochar via hydrothermal carbonization at 200 °C for 3 h. The resulting hydrochar (HC-AW) exhibited a predominantly amorphous carbon structure with retained oxygen-containing surface functionalities, and a solid yield of 44%, indicating efficient biomass conversion under subcritical conditions. Adsorption performance toward tetracycline was evaluated through pH-dependent experiments, kinetic modeling, equilibrium isotherms, and thermodynamic analysis. Maximum adsorption occurred under near-neutral conditions (pH ≈ 7), consistent with the interplay between tetracycline speciation and the hydrochar surface charge (pH_PZC ≈ 6.3), highlighting its potential applicability under realistic water treatment conditions without pH adjustment. Kinetic data were well described by the pseudo-second-order model, while equilibrium results were best fitted by the Langmuir model, with a maximum adsorption capacity of 14.94 mg g⁻¹ at 30 °C. Thermodynamic analysis indicated a spontaneous and slightly endothermic adsorption process. Overall, the results highlight the potential of annatto-derived hydrochar as a low-cost adsorbent and provide insight into the relationship between surface properties and adsorption behavior governing antibiotic removal from aqueous systems. Full article

The increasing occurrence of antibiotic residues in poultry meat represents a serious food safety concern associated with antimicrobial resistance and potential risks to human health. This study investigated the effects of electron beam irradiation on antibiotic residues and nutritional quality parameters of poultry meat. All experiments and data collection were carried out in 2025. Fresh poultry samples were irradiated using an ILU-10 pulsed linear electron accelerator at doses of 2, 4, 6, 8, and 10 kGy. Antibiotic residues were determined by HPLC-DAD, amino acid composition was analyzed using HPLC, and fatty acid profiles were evaluated by gas chromatography. Electron beam irradiation produced significant dose-dependent changes in the chemical composition of poultry meat. Total amino acid content decreased progressively with increasing irradiation dose, with reductions of up to 60–73% at 10 kGy depending on tissue type. Branched-chain and essential amino acids showed similar trends. Fatty acid analysis revealed a shift toward higher proportions of saturated fatty acids and a decline in monounsaturated and polyunsaturated fatty acids. The PUFA/SFA ratio decreased from 0.48 in control samples to 0.25 at 10 kGy. Tetracycline residues were not detected in any samples, whereas chloramphenicol residues were present in control meat but were progressively reduced after irradiation and became undetectable at doses ≥ 8 kGy. These results demonstrate that electron beam irradiation can effectively reduce antibiotic residues in poultry meat; however, higher irradiation doses may significantly alter amino acid and lipid composition. Therefore, optimization of irradiation parameters is necessary to balance improvements in food safety with the preservation of nutritional quality for the production of safe and sustainable food products. Optimization of irradiation parameters is therefore necessary to balance food safety benefits with preservation of nutritional quality. Furthermore, this research contributes to the achievement of Sustainable Development Goal (SDG) 2, while the obtained results also support SDG 3 by promoting safer food systems and protecting public health. Full article

Background/Objectives. The actin-binding protein EPLIN (epithelial protein lost in neoplasm), also known as LIMA1, contributes to the maintenance of cytoskeleton structure and dynamic. This protein, which interacts with multiple partners to regulate cell adhesion and migration, has been implicated in the progression of solid tumors and in tumor metastasis. Consequently, small molecules binding to EPLIN are actively searched. EPLIN has been characterized as a molecular target for the antitumor antibiotic albacarcin V which affects the cytoskeletal structure and induces cell growth arrest. Methods. We have modeled the binding of albacarcin and naturally occurring derivatives to EPLIN conformers, in order to locate the drug-binding site and to identify additional EPLIN binders. Nineteen compounds were studied, including albacarcins V (vinyl) and M (methyl), five gilvocarcins, four ravidomycins, two chrysomycins, and six related products (including polycarcin and fucomycin). Results. The modeling analysis confirmed the capacity of albacarcin V to bind to EPLIN and identified a few better binders. In particular, ravidomycin V bearing a dimethylamino sugar unit were identified as the best binders in the series, along with the two related anticancer natural products FE35A-B. Structure-binding relationships are discussed. The drug-binding site has been localized near the central residue Asn34 in the conformationally constrained domain between the two zinc-binding regions. Conclusions. This study provides guidance to the design of EPLIN inhibitors based on the ravidomycin core structure. Full article

Fluoroquinolones (FQs) are a kind of antibiotics, which are widely used in animal husbandry and aquaculture. However, the abuse of FQs can result in residues in foodstuffs of animal origin. Therefore, it is essential to establish a sensitive and accurate detection method for determination of FQs in food samples. An effective sample pretreatment method is a crucial procedure for enrichment of trace target compounds from complex matrix before HPLC analysis. As an emerging kind of sample pretreatment methods, magnetic solid-phase extraction (MSPE) has attracted much interest due to its characteristics including low cost, simplicity, and rapidity. In this study, a novel fluorinated magnetic covalent organic framework (Fe₃O₄@PDA@COF) was fabricated, which was used as an adsorbent in MSPE as well as coupled with HPLC to determine FQs in food samples. Under optimal conditions, the developed Fe₃O₄@PDA@COF-MSPE-HPLC-UV method possessed a wide linear range (1–250 µg·kg⁻¹) and low limits of detection (0.5–0.7 µg·kg⁻¹) with good linearity (R² ≥ 0.9938). Additionally, the method has been used to adsorb FQs from chicken samples. The recoveries of target FQs in spiked samples were 84.2–106.7% with relative standard deviations (RSDs) below 7.8%. These results demonstrated that the established method provides an efficient and sensitive solution for monitoring FQ residues in foodstuffs. Full article