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Agricultural practices such as extensive manure application (containing residual antibiotics) as fertilizer can also contribute to antibiotic pollution in soil, besides nitrous oxide (N2O) emissions. This dual impact designates certain agricultural soils as hotspots for heightened N2O emissions and antibiotic pollution. Nevertheless, our understanding of the repercussions of antibiotic residues on N2O emissions and the underlying mechanisms remain elusive. This comprehensive literature review investigated recent research findings regarding antibiotic contamination in agricultural soils and its influence on microbial N2O production and consumption. We scrutinized published data and field experimental monitoring results to analyze the prevalence and temporal variation of antibiotic residues in Chinese agricultural soils. By analyzing 482 log response ratio (lnR) datasets obtained from 41 independent articles, we established that quinolones (QNs) significantly (p < 0.05) boost N2O emissions. Conversely, cycloheximide and aminoglycosides (ARs) demonstrated notable inhibitory effects. Antibiotic pollution at concentrations within 1 ppm significantly promoted soil N2O emissions, whereas pollution at concentrations exceeding 10 ppm significantly (95% CI > 0) inhibited N2O emissions. Subsequently, we investigated the changes in oxidation-related microorganisms (AOM), nitrite-oxidizing bacteria (NOB), comammox bacteria, denitrifying bacteria as well as dissimilatory nitrate reduction to ammonium (DNRA) and anammox processes under antibiotic stress. Antibiotics unequally affect microbial N2O production and consumption. Our findings offer valuable insights into the complex relationship between antibiotics and N2O emissions, contributing to a better understanding of the environmental consequences of antibiotic contamination in agricultural systems. [ABSTRACT FROM AUTHOR]

The horizontal transfer of antibiotic resistance genes among bacteria is a pressing global issue. The bacterial defense system clustered regularly interspaced short palindromic repeats (CRISPR)-Cas acts as a barrier to the spread of antibiotic resistance plasmids, and CRISPR-Cas-based antimicrobials can be effective to selectively deplete antibiotic-resistant bacteria. While significant surveillance efforts monitor the spread of antibiotic-resistant bacteria in the clinical context, a major, often overlooked aspect of the issue is resistance emergence in agriculture. Farm animals are commonly treated with antibiotics, and antibiotic resistance in agriculture is on the rise. Yet, CRISPR-Cas efficacy has not been investigated in this setting. Here, we evaluate the prevalence of CRISPR-Cas in agricultural Enterococcus faecalis strains and its antiplasmid efficacy in an agricultural niche: manure. Analyzing 1,986 E. faecalis genomes from human and animal hosts, we show that the prevalence of CRISPR-Cas subtypes is similar between clinical and agricultural E. faecalis strains. Using plasmid conjugation assays, we found that CRISPR-Cas is a significant barrier against resistance plasmid transfer in manure. Finally, we used a CRISPR-based antimicrobial approach to cure resistant E. faecalis of erythromycin resistance, but this was limited by delivery efficiency of the CRISPR antimicrobial in manure. However, immunization of bacteria against resistance gene acquisition in manure was highly effective. Together, our results show that E. faecalis CRISPR-Cas is prevalent and effective in an agricultural setting and has the potential to be utilized for depleting antibiotic-resistant populations. Our work has broad implications for tackling antibiotic resistance in the increasingly relevant agricultural setting, in line with a One Health approach. [ABSTRACT FROM AUTHOR]

Antibiotics are the super drugs that have revolutionized modern medicine by curing many infectious diseases caused by various microbes. They efficiently inhibit the growth and multiplication of the pathogenic microbes without causing adverse effects on the host. However, prescribing suboptimal antibiotic and overuse in agriculture and animal husbandry have led to the emergence of antimicrobial resistance, one of the most serious threats to global health at present. The efficacy of a new antibiotic is high when introduced; however, a small bacterial population attains resistance gradually and eventually survives. Understanding the mode of action of these miracle drugs, as well as their interaction with targets is very complex. However, it is necessary to fulfill the constant need for novel therapeutic alternatives to address the inevitable development of resistance. Therefore, considering the need of the hour, this article has been prepared to discuss the mode of action and recent advancements in the field of antibiotics. Efforts has also been made to highlight the current scenario of antimicrobial resistance and drug repurposing as a fast-track solution to combat the issue. [ABSTRACT FROM AUTHOR]

This paper investigates the challenges of implementing antibiotic stewardship – reducing and optimizing the use of antibiotics – in agricultural settings of Low- and Middle-Income Countries (LMICs) as a strategic part of addressing the global problem of antimicrobial resistance (AMR). It does so through analysis of the rapidly transforming yet diverse Kenyan poultry sector, characterized by growing commercial operations alongside traditional smallholder farming. Our research involves interviews with farmers, processors, policymakers, and agro-veterinary stores in these settings. We blend Chandler's (2019, p. 8) notion of "antibiotics as infrastructure" with value chain frameworks to understand how the structural role of antibiotics in agriculture plays out through contrasting value chains, with different implications for stewardship. Weak regulation and intense market-based pressures are shown to drive widespread antibiotic use in poultry value chains involving small- and medium-sized farms supplying open markets. Antibiotic stewardship through adherence to agricultural and food safety standards is more evident, though unevenly observed, in value chains involving large commercial farms and processors supplying corporate buyers. Our findings reveal the complex structural roles of antibiotics in maintaining producer livelihoods in an intensely competitive and heterogeneous Kenyan poultry sector. This highlights challenges with applying global AMR policy to transforming food systems in LMICs without appropriate translation. We argue that attempts to reduce and optimize the use of antibiotics in agriculture must be informed by nuanced understandings of the roles of antibiotics in food systems in specific places including where very different scales and models of farming and value chain co-exist. [ABSTRACT FROM AUTHOR]

This paper seeks to understand how caring for new-born livestock is made possible, which practices of care are privileged and to what effect? These aims are situated in attempts to promote the prudent use of antibiotics amongst livestock farmers to prevent antimicrobial resistance. In focusing on the rearing of new-born calves on dairy and beef farms in England and Wales, the paper reveals how care is configured by different temporal orders, the tensions between different temporalities of care, the reasons for them and the strategies employed by calf rearers to manage these tensions. Drawing on the concept of the 'timescape', the paper shows how calf care temporalities are relationally enacted and configured by materials, infrastructures and technologies. Common (productivist) agricultural temporalities of care emphasise speed, urgency and efficiency. However, by analysing the practice of feeding colostrum and 'tubing' – the forced feeding of calves via a tube inserted into the oesophagus – we highlight how these rapid caring temporalities conflict with the slower, patient skills of calf rearing. At the same time, however, we show how care is rendered fluid as calf rearers find ways of accommodating seemingly discordant temporalities – what we call 'patient urgence' – allowing different temporalities to co-exist within agricultural timescapes. Nevertheless, we show how these practices of accommodation are themselves the result of a productivist temporal order that marginalises calves and calf rearers. We argue that these timescapes point to the need for broader structural and cultural changes within agriculture to reduce the use of antibiotics. [ABSTRACT FROM AUTHOR]

Avian colibacillosis (AC), caused by infection with Escherichia coli (E. coli), is a major threat to poultry health, food safety and public health, and results in high mortality and significant economic losses. Currently, new drugs are urgently needed to replace antibiotics due to the continuous emergence and increasing resistance of multidrug-resistant (MDR) strains of E. coli caused by the irrational use of antibiotics in agriculture and animal husbandry. In recent years, antimicrobial peptides (AMPs), which uniquely evolved to protect the host, have emerged as a leading alternative to antibiotics in clinical settings. CATH-2, a member of the antimicrobial cathelicidin peptide family, has been reported to have antibacterial activity. To enhance the antimicrobial potency and reduce the adverse effects on animals, we designed five novel AMPs, named C2-1, C2-2, C2-3, C2-4 and C2-5, based on chicken CATH-2, the secondary structures of these AMPs were consistently α-helical and had an altered net charge and hydrophobicity compared to those of the CATH-2 (1-15) sequences. Subsequently, the antimicrobial activities of CATH-2 (1-15) and five designed peptides against MDR E. coli were evaluated in vitro. Specifically, C2-2 showed excellent antimicrobial activity against either the ATCC standard strain or veterinary clinical isolates of MDR E. coli, with concentrations ranging from 2-8 mg/mL. Furthermore, C2-2 maintained its strong antibacterial efficacy under high temperature and saline conditions, demonstrating significant stability. Similarly, C2-2 retained a high level of safety with no significant hemolytic activity on chicken mature red blood cells or cytotoxicity on chicken kidney cells over the concentration range of 0-64 mg/mL. Moreover, the administration of C2-2 improved the survival rate and reduced the bacterial load in the heart, liver and spleen during MDR E. coli infection in chickens. Additionally, pathological damage to the heart, liver and intestine was prevented when MDR E. coli infected chickens were treated with C2-2. Together, our study showed that C2-2 may be a promising novel therapeutic agent for the treatment of MDR E. coli infections and AC. [ABSTRACT FROM AUTHOR]

Growers have depended on the specificity and efficacy of streptomycin and oxytetracycline as a part of their plant disease arsenal since the middle of the 20th century. With climate change intensifying plant bacterial epidemics, the established success of these antibiotics remains threatened. Our strong reliance on certain antibiotics for devastating diseases eventually gave way to resistance development. Although antibiotics in plant agriculture equal to less than 0.5% of overall antibiotic use in the United States, it is still imperative for humans to continue to monitor usage, environmental residues, and resistance in bacterial populations. This review provides an overview of the history and use, resistance and mitigation, regulation, environmental impact, and economics of antibiotics in plant agriculture. Bacterial issues, such as the ongoing Huanglongbing (citrus greening) epidemic in Florida citrus production, may need antibiotics for adequate control. Therefore, preserving the efficacy of our current antibiotics by utilizing more targeted application methods, such as trunk injection, should be a major focus. [ABSTRACT FROM AUTHOR]

This document discusses the global increase in antibiotic use and the resulting concern over antimicrobial resistance. It highlights the significant impact of antibiotic consumption on public health and the potential for a post-antibiotic era if action is not taken. The document also emphasizes the importance of community awareness and education in combating antimicrobial resistance. It presents eight studies from various countries that investigate community antibiotic use and stewardship, revealing variations in knowledge, attitudes, and practices related to antibiotics. The findings underscore the need for targeted campaigns and interventions to improve knowledge and promote responsible antibiotic use in different communities. [Extracted from the article]

Antibiotics in agricultural soil can be accumulated in crops and might pose a potential risk to human health. Nevertheless, there is a lack of knowledge about the impact of nitrogen fertilizers on the dissipation and uptake of antibiotics in soils. Therefore, our aim in this study is to investigate the effects of urea fertilizer on the residues of ciprofloxacin and its uptake by Chinese flowering cabbage (Brassica parachinensis L.) as affected by the associated changes on the soil microbial community. A pot experiment has been conducted using spiked soil with 20 mg ciprofloxacin /kg soil and fertilized with urea at dosages equal to 0, 0.2, 0.4, 0.8 t/ha. Application urea especially at 0.4 t/ha decreased the residue of ciprofloxacin in the soil and its uptake by the roots and its translocation to the shoots of Chinese flowering cabbage. The translocation factors (TFs) for ciprofloxacin were significantly decreased (P < 0.05) only at the treatment of 0.4 t/ha, while no significant difference of bio-concentration factors (BCFs). The average well color development (AWCD) values, Shannon diversity, and richness index were higher in the fertilized than the un-fertilized soils, and all such indicators were greater at the treatment of 0.4 t/ha than at 0.2 and 0.8 t/ha. The carbon substrate utilization of phenolic acids at the treatments of 0.4 t/ha were greater than with other levels of urea fertilizer. In conclusion, moderate urea addition significantly increased soil microbial activity and abundance, which in turn promoted the ciprofloxacin dissipation in soil and plant tissue. The present study provides an economical and operational strategy for the remediation of ciprofloxacin contaminated soils. [ABSTRACT FROM AUTHOR]

This study aims to understand the adsorption/desorption process in six agricultural soils of two antibiotics, Ciprofloxacin (CIP) and Trimethoprim (TRI), widely used today and the influence of pH on this process. Antibiotics can reach the soil through the application of sludge and effluents from wastewater treatment plants and are directly influenced by changes in pH, once in the soil. Therefore, this study with batch experiments allows us to know the adsorption process in a pH range between 2 and 12, in six soils with different organic carbon content, between 1% and 7.7%. The results obtained show that the adsorption of CIP has its maximum at pH between 5 and 7; above and below this range, the adsorption decreases. The soils with the highest organic carbon content (between 4.4% and 7.7%) are those with the highest adsorption. The values for each forms in which the CIP molecule is found are: for KdCIP+, between 0.887 and 8.289 L kg-1; for KdCIP-, between 0.670 and 5.440 L kg-1, while for KdCIP0, the values do not differ from 0, except soils 1 and 3, whose values are 0.206 and 0.615 L kg-1, respectively. Regarding TRI, the maximum adsorption takes place at acidic pHs, below 6 for all soils. Above these values, desorption decreases. The Kd values for each of the species vary between 0.085 and 0.218 L kg-1 for KdTRI+, between 0.011 and 0.056 L kg-1 for KdTRI0, and between 0.092 and 0.189 L kg-1 for KdTRI-. For both antibiotics, the highest adsorption was achieved in the soil with the highest organic carbon content (7.7%). Comparing both antibiotics, we see that CIP presents the highest adsorption, and in the case of desorption, for CIP, it varies between 3.7% and 75.8%, with the maximum desorption at basic pHs. In the case of TRI, desorption is higher, varying between 9.4% and 99.1%, with the maximum around neutrality, except for two soils, whose maximums are at pH of 4.3 and 9.5. These results should be taken into account, as once they reach the soil, pH will be a determining factor in their behaviour and fate. [ABSTRACT FROM AUTHOR]

Ningnanmycin is a widely used antibiotic in agricultural production that effectively controls fungal and viral diseases in tea trees and chrysanthemums. The polarity characteristic of ningnanmycin has posed limitations on the development of robust detection methods, thereby hindering effective monitoring and control measures. By combining cation exchange solid phase extraction (SPE) with hydrophilic interaction chromatography tandem mass spectrometry (HILIC-MS/MS), we have effectively tackled the issue pertaining to the separation and retention of ningnanmycin. The average recoveries of ningnanmycin in green tea, black tea, and chrysanthemum were 77.3–82.0%, 80.1–81.5%, and 74.0–80.0%, respectively. The intraday and interday relative standard deviations (RSDs) were below and equal to 7.7%. Good linearity was observed in the concentration range of 1–1000 μg/L (R2 > 0.998). The limits of detection (LODs) ranged from 1.1 μg/kg to 7.1 μg/kg, and the limits of quantification (LOQs) ranged from 3.6 μg/kg to 23.7 μg/kg for ningnanmycin. These results indicate the good accuracy, repeatability, reproducibility, and sensitivity of the method. It is suitable for detecting ningnanmycin in tea and chrysanthemum. [ABSTRACT FROM AUTHOR]

The text discusses the issue of antimicrobial resistance (AMR) and its global impact on human and animal health, healthcare systems, economies, and the environment. It emphasizes the need for joint efforts and collaboration among various stakeholders to prevent the emergence and spread of drug-resistant infections. The text highlights the consequences of AMR, such as increased morbidity, mortality, healthcare expenses, and economic costs. It also emphasizes the importance of responsible use of antibiotics, surveillance systems, infection prevention and control practices, and interdisciplinary partnerships in addressing AMR. The text concludes by calling for continued collaboration at local, national, and international levels to ensure a healthier and more resilient future for all. [Extracted from the article]

Fire blight, caused by Erwinia amylovora, is a devastating bacterial disease that threatens apple and pear production. It is mainly controlled by using antibiotics, such as streptomycin. Due to development of E. amylovora resistant strains and the excessive agricultural use of antibiotics, there is an increased awareness of the possibility of antibiotic resistance gene transfer to other microbes. Urgent development of biocontrol agents (BCAs) is needed that can be incorporated into integrated pest management programs as antibiotic alternatives. A novel phage-carrier system (PCS) that combines an antagonistic bacterium, Pantoea agglomerans, with its ability to act as a phage-carrier bacterium for Erwinia phages has been developed. The low viability of P. agglomerans cells following spray-drying (SD) has been a challenge for the industrial-scale production of this PCS. Here, an SD protocol was developed for P. agglomerans by modifying the growth medium and bacterial cell formulation using D(+)-trehalose and maltodextrin. The developed protocol is amenable to the industrial-scale production of the BCA/PCS. The P. agglomerans viability was greater than 90% after SD and had a shelf life at 4 °C of 4 months, and reconstituted cells showed a 3 log reduction in E. amylovora counts with a pear disc assay. [ABSTRACT FROM AUTHOR]

The indiscriminate use of antibiotics in agriculture has raised concerns about antibiotic residues in food products, necessitating robust analytical methods for detection and quantification. In this study, our primary aim was to develop a robust and advanced liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology specifically designed for the accurate quantification of ticarcillin degradation products in tomato leaves. The choice of ticarcillin as the target analyte stems from its frequent use in agriculture and the potential formation of degradation products, which can pose a threat to food safety. The use of tomatoes as the target sample matrix in this study is justified by their significance in human diets, their widespread cultivation, and their suitability as a model for assessing antibiotic residue dynamics in diverse agricultural environments. By optimizing the MS/MS parameters, the study successfully demonstrates the practicality and reliability of the employed LC-MS/MS method in accurately assessing ticarcillin degradation product (Thiophene-2-Acetic acid and Thiophene-3-Acetic acid) levels. The chromatographic separation was achieved using a specialized column, ensuring high resolution and sensitivity in detecting analytes. Multiple reaction monitoring (MRM) data acquisition was employed to enhance the selectivity and accuracy of the analysis. The developed method exhibited excellent linearity and precision, meeting the stringent requirements for antibiotic residue analysis in complex matrices. Key outcomes of this study include the successful identification and quantification of ticarcillin and its degradation products in tomato leaves, providing crucial insights into the fate of this antibiotic in agricultural settings. The methodology's applicability was further demonstrated by analyzing real-world samples, highlighting its potential for routine monitoring and ensuring food safety compliance. In summary, our study constitutes a noteworthy advancement in the domain of antibiotic residue analysis, offering a reliable method for quantifying ticarcillin degradation products in tomato leaves. The optimized parameters and MRM-based LC-MS/MS approach enhance the precision and sensitivity of the analysis, opening up opportunities for further studies in the assessment of antibiotic residues in agricultural ecosystems. [ABSTRACT FROM AUTHOR]

Pseudostellaria heterophylla (or Taizishen in Chinese), a medicinal, edible, and ornamental Chinese herb, is seriously affected by leaf spot disease (LSD). Oligochitosan is a natural agricultural antibiotic that is produced via the degradation of chitosan, which is deacetylated from chitin; pyraclostrobin is a broad-spectrum and efficient strobilurin fungicide. In this work, the ability of pyraclostrobin, oligochitosan, and their formula to manage P. heterophylla leaf spot disease and their role in its resistance, leaf photosynthesis, agronomic plant traits, root growth, and root quality were studied. The results show that the joint application of oligochitosan and low-dosage pyraclostrobin could control LSD more efficiently, with control effects of 85.75–87.49% compared to high-dosage pyraclostrobin or oligochitosan alone. Concurrently, the application of this formula could more effectively improve the resistance, leaf photosynthesis, agronomic plant traits, root yield, and medicinal quality of P. heterophylla, as well as reduce the application of pyraclostrobin. This finding suggests that 30% pyraclostrobin suspension concentrate (SC) 1500-time + 5% oligosaccharin aqueous solutions (AS) 500-time diluent can be recommended for use as a feasible formula to manage LSD and reduce the application of chemical pesticides. [ABSTRACT FROM AUTHOR]

• Both plant- and animal-derived fertilizers enhanced soil resistance at spout stage. • Compositions of enriched ARGs in the two amended soils were distinct at sprout stage. • Plant-derived fertilizer showed preference for enriching multidrug resistance genes. • Plant-derived fertilizer enriched soil ARGs by nourishing indigenous bacteria. • Enriched ARGs were linked to distinct bacterial taxa in the two amended soils. Animal manures have been demonstrated to enhance antibiotic resistance in agricultural soils. However, little is known about the effects of plant-derived fertilizer on soil antibiotic resistome. Herein, metagenomic sequencing was used to investigate the effects of a plant-derived fertilizer processed from sugarcane and beet on soil antibiotic resistance genes (ARGs) in a soybean field along crop growth stages. ARG profiles in the soils amended by plant-derived fertilizer were compared with those in the soils amended by chicken manure. The abundance and diversity of total ARGs in the soils amended by plant-derived fertilizer were significantly (P < 0.05) elevated at the sprout stage, to a level comparable to that in the manured soils. Whereas, unlike chicken manure mainly introducing manure-borne ARGs to soil, the plant-derived fertilizer was indicated to mainly enrich multidrug resistance genes in soil by nourishing indigenous bacteria. ARGs with abundances in amended soils significantly (P < 0.05) higher than in unamended soils at the sprout stage of soybean were considered as enriched ARGs. Decrease in the abundance of the enriched ARGs was observed in both the amended soils from the sprout to the harvest. Network analysis further identified Proteobacteria and Bacteroidetes as the primary bacterial taxa involved in the temporal variation of the enriched ARGs in the soils amended by plant-derived fertilizer, while in manured soils were Firmicutes and Actinobacteria. As revealed by multivariate statistical analyses, variation of the enriched ARGs in the soils amended by plant-derived fertilizer was majorly attributed to the response of co-occurred bacteria to depleting nutrients, which was different from the failed establishment of manure-borne bacteria in the manured soils. Our study provided field-based evidence that plant-derived fertilizer stimulated the intrinsic antibiotic resistome, and proposed attention to the un-perceived risk since some clinically relevant ARGs originate and evolve from natural resistome. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, a method is proposed for the determination of antibiotics classified by the World Health Organization as critically important (four macrolides and three quinolones) and highly important (one tetracycline, one diaminopyridine, and three sulfonamides) and eight of their metabolites. The method is based on ultrasound-assisted extraction, dispersive solid-phase extraction clean-up, and analytical determination by liquid chromatography–tandem mass spectrometry. Variables affecting each stage of the analytical method were thoroughly optimised. The method was validated for its application to sewage sludge from different treatment stages (non-treated sludge: primary and secondary sludge; and treated sludge: digested sludge and compost) and to agricultural soil. Limits of quantification were in the range of 0.03–7.50 ng g−1 dry weight (dw) for most of the compounds. Accuracy values were in the range of 70–102%. Precision was below 17%. The application of the method to real samples revealed that macrolides and fluoroquinolones were the antibiotic classes at the highest concentrations in all types of samples. The lowest concentrations of antibiotics were measured in compost (highest concentration: 27 ng g−1 dw, corresponding to norfloxacin) and soil samples (highest concentration: 93 ng g−1 dw, corresponding to a metabolite of clarithromycin). The proposed method is the first developed to date for the determination of multiclass antibiotics and their main metabolites in sludge from different treatment stages. The method can provide a useful tool for obtaining information about antibiotics in sewage sludge prior to its application to agricultural soils and in agricultural soils. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are major components of innate immunity in plants and animals. AMP genes have significant intra- and interspecific polymorphism, the role of which is poorly understood. Previously, by high-throughput transcriptome sequencing of wheat plants, we identified defensin genes up-regulated upon infection with the pathogenic fungus Fusarium oxysporum and/or treatment with resistance inducers. In the present work, a bioinformatic search in NCBI databases for peptide homologs of these defensins was carried out using the sequences of their γ-cores, the sites of the molecules responsible for antimicrobial activity. DEFL1-16 homologs were identified in 95 species of angiosperms belonging to 48 families and 30 orders of monocotyledonous and dicotyledonous plants. The ubiquitous distribution of this defensin in angiosperms suggests its involvement not only in defense but also in other processes in flowering plants. Homologs of other defensins induced by infection were found only in plants of the Poaceae family, which suggests the existence of a Poaceae-specific defense mechanism associated with the expression of these defensins. Among the γ-core variants of wild plant defensins identified in the study, the peptides with better antimicrobial activity compared to wheat may be present, which are of considerable interest for the development of new antibiotics for medicine and agriculture. [ABSTRACT FROM AUTHOR]

This paper examines diverse perspectives around the concept of responsibility concerning antibiotic use in animal agriculture. Antibiotic use in agriculture has been identified as a source of antimicrobial resistance, one of the largest public health threats today. In the United States, efforts to curb antibiotic use in farming draws on a diverse range of actors—including farmers, veterinarians, consumers, and public health advocates—and relies on a mix of industry standards and federal guidelines around responsible use. The paper selects a similarly diverse range of people and employs Q methodology to query the points of disagreement and consensus around the practices that constitute responsible antibiotic use in animal agriculture, and who is responsible for antimicrobial resistance. We find a diverse mix of actor types across three discourses, but with clear differences between farmers and public health advocates. We also argue that, in some cases, points of disagreement and agreement are often based on different interpretations of ideas, indicating points of common ground where there might appear to be disagreement, and areas of difference where there appears to be agreement. We argue that these flexible interpretations of some of the key issues around antibiotic use are nevertheless grounded in durable differences in views of what agriculture is and what it should be. [ABSTRACT FROM AUTHOR]

Agricultural antibiotics are widely used to inhibit the growth of phytopathogenic bacteria involved in plant diseases. However, continuous antibiotic overuse in crop production may lead to the development of antibiotic resistance in phytopathogenic bacteria. This study was conducted to evaluate the resistance to three different agricultural antibiotics (oxytetracycline+streptomycin, streptomycin, and validamycin A) in 91 strains of phytopathogenic bacteria including Pectobacterium carotovorum, Pseudomonas syringae pv. actinidiae, Clavibacter michiganensis subsp. michiganensis, C. michiganensis subsp. capsici, and Xanthomonas arboricola pv. pruni. Bacterial growth in the presence of various concentrations of validamycin A was also assessed spectrophotometrically by analyzing the optical density. All strains did not grow when the cells were exposed to oxytetracycline+streptomycin or 100× of streptomycin. However, among the 91 strains, 4% and 2% strains showed bacterial growth at the concentrations of 1× and 10× of streptomycin, respectively. Furthermore, 97%, 93%, and 73% strains were resistant to the 1×, 10×, and 100× of validamycin A, respectively, and especially, P. carotovorum contained the highest resistance to the validamycin A. Minimum bactericidal concentration values of validamycin A did not correlate with the patterns of agricultural antibiotic resistance. Further studies are needed to understand the incidence and development of antibiotic resistance in phytopathogenic bacteria.

The discovery of antibiotics has fully changed medicinal therapy. However, with the increased therapeutic use of antibiotics, bacteria continued to develop mechanisms to resist these drugs. Today, antibiotics are being prescribed to a range of patients from the common cold to cancer. Antibiotics are poorly metabolized in the body, about 70–80% of them are excreted out. The imprudent and exceeding use of clinically significant antibiotics in agriculture, veterinary medicine, and human healthcare is a causative factor in the escalating global antimicrobial resistance (AMR) epidemic. Researchers and stakeholders are increasingly expressing concern regarding the environment playing a role as a reservoir for AMR and its significant contribution to the dissemination of antimicrobial resistance genes. Multiple drivers contribute to the dissemination of antibiotic-resistant bacteria (ARB) and their associated antibiotic-resistance genes (ARGs). These drivers include direct factors, e.g., the usage of antimicrobial drugs in healthcare, agriculture, livestock, and the environment. The release of antibiotic residues from various domestic settings also contributes to this phenomenon. The main focus of global mitigation strategies is to identify environments that pose a high risk of resistance development and dissemination. The transmission of AMR is subsequently influenced by various factors, including infection control standards, sanitation practices, availability of clean water, access to reliable antimicrobials and diagnostics, and treatment of agriculture and hospital waste. Therefore, we aim to present the global problem of environmental antibiotic resistance and its dissemination in the environment. The key hotspots of ARB and ARGs and their dissemination from the environment to humans are discussed. Further, we aim to highlight the mechanisms of acquiring antibiotic resistance by the environmental bacteria population and possible approaches to combat antibiotic resistance. [ABSTRACT FROM AUTHOR]

BACKGROUND: To find more effective agricultural antibiotics, a class of new 2‐aminothiazole derivatives containing the 4‐aminoquinazoline moiety were synthesized and evaluated for their antimicrobial properties against phytopathogenic bacteria and fungi of agricultural importance. RESULTS: All the target compounds were fully characterized by 1H NMR, 13C NMR, and high‐resolution mass spectrometry. The bioassay results showed that compound F29 with a 2‐pyridinyl substituent exhibited an outstanding antibacterial effect against Xanthomonas oryzae pv. oryzicola (Xoc) in vitro, having an half‐maximal effective concentration (EC50) value as low as 2.0 μg/mL (over 30‐fold more effective than the commercialized agrobactericide bismerthiazol, with an EC50 value of 64.3 μg/mL). In addition, compound F8 with a 2‐fluorophenyl group demonstrated a good inhibitory activity toward the bacterium Xanthomonas axonopodis pv. citri (Xac), around twofold more active than bismerthiazol in terms of their EC50 values (22.8 versus 71.5 μg/mL). Interestingly, this compound also demonstrated a notable fungicidal effect against Phytophthora parasitica var. nicotianae, with an EC50 value largely comparable with that of the commercialized fungicide carbendazim. Finally, mechanistic studies revealed that compound F29 exerted its antibacterial effects by increasing the permeability of bacterial membranes, reducing the release of extracellular polysaccharides, and triggering morphological changes of bacterial cells. CONCLUSION: Compound F29 has promising potential as a lead compound for developing more efficient bactericides to fight against Xoc. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Good water quality for livestock is critical for preserving animal health, ensuring the quality of animal products, supplying safe food, and increasing food production economics. Higher water levels of toxic compounds than permitted can impair meat, fat, eggs, and milk production, lower fertility, and represent public health hazards. Water picks up pollutants from its surroundings and those caused by animal and human activities. Many physicochemical parameters were used to ensure water quality, including pH, salt, taste, color, alkalinity, odor, and hardness. Water quality, directly and indirectly, impacts livestock performance and, thus, the poultry industry. Employing drinking water as a carrier of drugs still faces substantial barriers. The effectiveness of vaccinations and drugs is affected by inadequate water quality. Furthermore, contaminated water and poor nutrition negatively affect broiler chicken immunity, survival, and production. Antibiotics are widely utilized in poultry production to preserve animal health and growth. They can eliminate harmful bacteria in the gut, reduce the load on the immune system, optimize the digestive system, and boost growth performance. However, the abuse of antibiotics in animal agriculture has resulted in antibiotic-resistant infections threatening people and animals. As a result of its positive impact on the metabolome and gut microbiome, the natural antimicrobial combination could be used as an alternative; improving broiler chicken growth performance without negatively affecting the environment is currently paramount. [ABSTRACT FROM AUTHOR]

The creation and continued development of antibiotics have revolutionized human health and disease for the past century. The emergence of antimicrobial resistance represents a major threat to human health, and practices that contribute to the development of this threat need to be addressed. Since the 1950s, antibiotics have been used in low doses to increase growth and decrease the feed requirement of animal-derived food sources. A consequence of this practice is the accelerated emergence of antimicrobial resistance that can influence human health through its distribution via animal food products. In the laboratory setting, sublethal doses of antibiotics promote the expansion of bacterial persister populations, a low energy, low metabolism phenotype characterized broadly by antibiotic tolerance. Furthermore, the induction of persister bacteria has been positively correlated with an increased emergence of antibiotic-resistant strains. This body of evidence suggests that the use of antibiotics in agriculture at subtherapeutic levels is actively catalyzing the emergence of antimicrobial-resistant bacteria through the expansion of bacterial persister populations, which is potentially leading to increased infections in humans and decreased antibiotic potency. There is an urgent need to address this debilitating effect on antibiotics and its influence on human health. In this review, we summarize the recent literature on the topic of emerging antimicrobial resistance and its association with bacterial persister populations. [ABSTRACT FROM AUTHOR]

This article discusses a study conducted in Cambodia on the prevalence and antibiotic resistance of bacteria in fermented fish and vegetables. The study found that E. coli and other species were present in the samples, with most bacteria showing resistance to multiple antibiotics. The article highlights the potential hazards and antimicrobial resistance in Cambodian fermented foods. The study also examines the physicochemical properties and bacterial contamination of fermented products, finding variations in pH, salt concentration, and water activity. The study emphasizes the need for basic sanitary measures during food processing to prevent the consumption of contaminated fermented products. [Extracted from the article]

Antimicrobial resistance (AMR) is one of the major challenges faced by society, with the real threat of the failure of many medical procedures. Antibiotics are also used in livestock production and provide a potential pathway to increasing AMR. The central challenge involves ensuring animal health and welfare while securing the long-term effectiveness of antibiotics. This paper reports the results of a survey of 5693 respondents from the customer panels of four major UK supermarkets regarding preferences and attitudes towards antibiotic use in food animals, and their perspectives on how the balance between animal welfare and human benefit can be achieved. The results of these surveys are consistent with those from other countries that found that consumers generally have limited knowledge about antibiotic use in agriculture and AMR, with around 50% responding "don't know" to many questions. There was agreement about the benefits of antibiotics outweighing harm, with 40% agreeing that, overall, the use of antibiotics to treat disease in farm animals delivers more benefit than harm. However, 44% neither agreed nor disagreed, indicating a high level of uncertainty and a situation that is potentially unstable. The seriousness of the AMR challenge is such that continued action for the more discriminating use of antibiotics must continue. [ABSTRACT FROM AUTHOR]

Residual antibiotics in agricultural soils can be of concern due to the development of antibiotic resistant microorganisms. Among various antibiotics, oxytetracycline (OTC), streptomycin (ST), and validamycin A (VA) have been used for agricultural purposes in South Korea; however, studies on the biodegradation of these antibiotics in soil are limited. Therefore, this study investigated the effects of pH (5.5, 6.8, and 7.4) and temperature (1.8, 23.0, and 31.2 °C) conditions on the biodegradation of these antibiotics in soil. The biodegradation tests were carried out in the field soil (FS) and rice paddy soil (RS) for 30 d with OTC and ST and 10 d with VA, and the residual antibiotics concentrations were monitored over the degradation period. Under various conditions, the degradation rates of ST was lower (11–69%) than that of OTC (60–90%) and VA (15–96%). The degradation half-lives of OTC and VA tend to decrease with increasing pH value, while the degradation half-life of ST tend to increase with increasing pH value. But, the effect of soil pH on the antibiotics degradation was not statistically significant, except for ST in the FS and RS and VA in the FS. The degradation of three antibiotics was greater at higher temperatures (23.0 °C and 31.2 °C) than at lower temperature (1.8 °C), and the degradation half-lives decreased with increasing temperature. The different degradation characteristics of different antibiotics in soil can be explained by the different characteristics of the antibiotics (e.g., sorption affinity, chemical forms) and soil (e.g., organic matter content). The results suggest that the degradation characteristics of antibiotics need to be considered in order to properly manage the residual antibiotics in soil. [ABSTRACT FROM AUTHOR]

To combat the OneHealth threat of antimicrobial resistance (AMR), the use of antibiotics in agriculture is subject to significant governance-led initiatives to change food system behaviours, including promoting more responsible use of antibiotics on farms through market-level interventions. To combat knowledge gaps about how consumers perceive risks associated with antibiotic use and AMR in farming, the current study carried out an in-depth qualitative focus group study incorporating a risk information exposure exercise with food consumers on the island of Ireland (n = 36). Using a theoretical lens of social representation theory, a thematic analysis of the collected data identified how participants made sense of, often new, information on agricultural antibiotic use and AMR. Participants displayed high awareness and concern for AMR but low understanding and misconceptions around AMR transmission from the agri-food sector. Social representations about antibiotics and food and farming systems shaped preferences for a movement away from antibiotics in farming, and in particular, prophylactic use. However, participants acknowledged the role of antibiotics to protect animal health and the integrity of the food supply chain. They debated the lack of a simple fix to antibiotics in the agri-food system and revealed preferences for preventive actions at farm level and supporting actions at market level. The study highlights the need to first tackle low levels of public understanding through effective risk communication including strategies such as targeted message framing and proactive, cross-sector OneHealth awareness campaigns, followed by the introduction of a trusted antibiotic use food labelling system. [ABSTRACT FROM AUTHOR]

The article discusses the significance and challenges of antimicrobial peptides (AMPs) in veterinary medicine as an alternative to antibiotics due to concerns about antibiotic resistance. AMPs have broad-spectrum activities against pathogens and immune-modulatory effects. Challenges include cost-effective production and short half-life in animals, with solutions such as recombinant DNA technology and protective carriers being explored. While AMPs show promise as an alternative to antibiotics, further research is needed to address production challenges for widespread use in farm animal treatment and nutrition. [Extracted from the article]

Background and Aim: Inappropriate antibiotic use in the agricultural sector is a crucial driver of antibiotic resistance which is a global public health concern. Although there are many studies on antibiotic use in livestock production, studies on antibiotic use in crop production are relatively scarce. This study aimed to determine farmers' knowledge, attitudes, and practices (KAP) toward antibiotic use in Mandarin orchard and investigate their associations with the antibiotic susceptibility patterns among Mandarin orchard farmers in Fang District, Chiang Mai Province, Thailand. Materials and Methods: This cross-sectional study was conducted in Fang District between November and December 2021. The participants in this study were 151 farmers (farm owners and farm workers) in ten Mandarin orchards. All participants completed face-to-face interviews using a structured questionnaire. Nasal swabs were collected from 100 participants. The disk diffusion and staphylococcal chromosome cassette mec typing methods were used to test the antibiotic susceptibility of the isolates. Results: All farmers involved in the activities related to antibiotic exposure, 39.7% prepared or mixed antibiotics, and 82.8% injected antibiotics into Mandarin trees. Overall, farmers in this study had moderate levels of knowledge and attitudes and good antibiotic use practices. There was a significant association between attitudes and practices (r = 0.312, p < 0.001). In the analysis of drug resistance of the bacterial isolates, Staphylococcus aureus was detected in 16 of 100 nasal swab samples, with resistance to penicillin (16/16), methicillin (cefoxitin) (1/16), and tetracycline (6/16). Conclusion: This is the first report on farmers' and farm workers' KAP and antibiotic use in crop production, specifically Mandarin production. The findings of this research will help in developing plans and strategies to encourage the appropriate use of antibiotics and prevent antibiotic resistance or microbial resistance in plant production. [ABSTRACT FROM AUTHOR]

Fluoroquinolone (FQ) is a type of widely used antibiotic in agriculture and aquaculture, and exposure to low doses of FQs may result in the transfer of resistance between animal and human pathogens. Based on the optimization of the operating parameters, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) standard curve was constructed for the simultaneous detection of 13 FQs, including enrofloxacin (ENR), ciprofloxacin (CIP), sarafloxacin (SAR), ofloxacin (OFL), norfloxacin (NOR), pefloxacin mesylate (PM), pefloxacin (PEF), enoxacin (ENX), marbofloxacin (MAR), fleroxacin (FLE), lomefloxacin (LOM), danofloxacin (DAN), and difloxacin (DIF). The limit of detection (LOD, computed as IC10) and sensitivity (IC50) of the ic-ELISA for ENR were 0.59 μg/L and 19.23 μg/L, respectively. The precision and dependability of the detection results of this ic-ELISA were properly verified by HPLC in Rana catesbeianus samples. This indicated that the established ic-ELISA approach could be utilized to determine the FQs in Rana catesbeianus. In addition, this ic-ELISA, based on a broad-spectrum antibody, provides a technical reference and potential strategy for an immunoassay of hazard factors with similar structure. [ABSTRACT FROM AUTHOR]

Introduction: The widespread use of antibiotics in animal agriculture has increased the resistance of Escherichia coli, and pathogenic E. coli often harbor complex virulence factors. Antimicrobial resistance in pathogenic bacteria can cause public health problems. Correlation analyses of the resistance, virulence, and serotype data from the pathogenic bacteria found on farms and in the surrounding environment can thus provide extremely valuable data to help improve public health management. Methods: In this investigation, we have assessed the drug resistance and virulence genes as well as the molecular typing characteristics of 30 E. coli strains isolated from duck farms in the Zhanjiang area of China. Polymerase chain reaction was used to detect the drug resistance and virulence genes as well as serotypes, and whole-genome sequencing was used to analyze the multilocus sequence typing. Results: The detection rates for the oqxA resistance gene and fimC virulence gene were highest (93.3%, respectively). There were no correlations between the drug resistance and virulence gene numbers in the same strain. The epidemic serotype was O81 (5/24), ST3856 was an epidemic sequence type, and strains I-9 and III-6 carried 11 virulence genes. The E. coli strains from the duck farms in the Zhanjiang area were thus found to have a broad drug resistance spectrum, various virulence genes, complex serotypes, and certain pathogenicity and genetic relationship. Discussion: Monitoring the spread of pathogenic bacteria and the provision of guidance regarding the use of antibiotics in the livestock and poultry industries will be required in the future in the Zhanjiang area. [ABSTRACT FROM AUTHOR]

Antibiotics reach to agricultural areas through different means and affect the growth and development of plants. The aim of this research is to investigate some biochemical responses caused on pepper plants by enrofloxacin (Enro), an antibiotic widely used on veterinary medicine, and to determine how ascorbate (AsA), which is an antioxidant, affects these responses. For this purpose, activities of ascorbate peroxidase (APX), glutathione S-transferase (GST) and glutathione reductase (GR) as well as total chlorophyll, carotenoids, proline, AsA, glutathione (GSH), malondialdehyde (MDA) contents of pepper plants that are treated with Enro at different concentrations (10, 100, and 1000 µg/L) were analyzed. In general, while total chlorophyll and carotenoid contents as well as APX activities decreased; MDA, glutathione and AsA contents as well as GST and GR activities increased for plants treated with Enro especially at high concentrations. While MDA content decreased with treatment of 100 mg/L ASA as foliar, total chlorophyll and carotenoid contents increased, and antioxidant defense responses were induced. Our findings indicate that treatment with Enro induced some phytotoxic responses on pepper plants and exogenous AsA treatment alleviated negative effects of Enro. [ABSTRACT FROM AUTHOR]

In dairy farming, mastitis treatment is the most common reason for antimicrobial use. The overuse or misuse of antibiotics in agriculture has been associated with the development and spread of antimicrobial resistance (AMR). Traditionally, blanket dry cow therapy (BDCT), in which all cows receive antibiotic treatment, was used prophylactically to prevent and manage disease spread. In recent years, there has been a move toward selective dry cow therapy (SDCT), in which only clinically infected cows are treated with antibiotics. This study aimed to explore farmer attitudes toward antibiotic use (ABU), using the COM-B (Capability-Opportunity-Motivation-Behavior) model as a framework, to identify predictors of changing behavior toward SDCT and suggest interventions to encourage its uptake. Participant farmers (n = 240) were surveyed online between March and July 2021. Five items were found to be significant predictors of farmers having stopped BDCT: (1) having lower knowledge of AMR, (2) greater awareness of AMR and ABU (Capability), (3) feeling social pressure to reduce ABU (Opportunity), and (4) having greater professional identity, and (5) having positive emotions associated with stopping BDCT (Motivation). Direct logistic regression found that these 5 factors explained between 22 and 34.1% of the variance in making changes to BDCT practices. Additionally, objective knowledge was not correlated with current positive antibiotic practices, and farmers often perceived their antibiotic practices as more responsible than they actually were. A multifaceted approach, encompassing each of the predictors highlighted, should be taken to encourage farmer behavior change in relation to stopping BDCT. Additionally, as farmers' perceptions of their own behaviors may not align with their actual practices, awareness raising of what constitutes "responsible" behavior should be targeted at dairy farmers to motivate them to take action and adopt more responsible antibiotic practices. [ABSTRACT FROM AUTHOR]

Phosphonate natural products are renowned for inhibitory activities which underly their development as antibiotics and pesticides. Although most phosphonate natural products have been isolated from Streptomyces, bioinformatic surveys suggest that many other bacterial genera are replete with similar biosynthetic potential. While mining actinobacterial genomes, we encountered a contaminated Mycobacteroides data set which included a biosynthetic gene cluster predicted to produce novel phosphonate compounds. Sequence deconvolution revealed that the contig containing this cluster, as well as many others, belonged to a contaminating Bacillus and is broadly conserved among multiple species, including the epiphyte Bacillus velezensis. Isolation and structure elucidation revealed a new di- and tripeptide composed of L-alanine and a C-terminal L-phosphonoalanine which we name phosphonoalamides E and F. These compounds exhibit broad-spectrum antibacterial activity, including strong inhibition against the agricultural pests responsible for vegetable soft rot (Erwinia rhapontici), onion rot (Pantoea ananatis), and American foulbrood (Paenibacillus larvae). This work expands our knowledge of phosphonate metabolism and underscores the importance of including underexplored microbial taxa in natural product discovery. IMPORTANCE Phosphonate natural products produced by bacteria have been a rich source of clinical antibiotics and commercial pesticides. Here, we describe the discovery of two new phosphonopeptides produced by B. velezensis with antibacterial activity against human and plant pathogens, including those responsible for widespread soft rot in crops and American foulbrood. Our results provide new insight on the natural chemical diversity of phosphonates and suggest that these compounds could be developed as effective antibiotics for use in medicine or agriculture. [ABSTRACT FROM AUTHOR]

Antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) are among the top pharmaceutical contaminants that have been often found in the aquatic environment. The presence of these contaminants in the aquatic environment is of great concern since it has a negative impact on both ecology and human health. In contrast to other tertiary treatments, adsorption stands out as a viable treatment approach since it provides benefits such as easier operating conditions with no byproduct formation. Commercial activated carbon is widely researched as a pharmaceutical adsorbent, but its large-scale applicability is constrained by its high cost. Agricultural waste also contains a large amount of various functional groups, which may be adapted to surface modification to increase its adsorption ability. In this regard, this study is designed to review the recent progress of efficient adsorbents derived from various agricultural wastes for the removal of antibiotics and NSAIDs contaminants from water bodies. Adsorbents made from agricultural waste have important benefits over commercial activated carbon for the reduction in waste while controlling water pollution. [ABSTRACT FROM AUTHOR]

Misuse and overuse of antibiotics have contributed to the rise of antimicrobial resistance as one of the top public health threats. Antibiotics and antibiotic resistance genes (ARGs) are prevalent in agricultural soils due to the widespread application of livestock and organic wastes. However, information about the occurrence, distribution, and risk of antibiotics and ARGs in agricultural soils is lacking for many scenarios. In this study, based on 2225 observations from 135 independent studies, we summarized the concentration or abundance of antibiotics or ARGs under different fertilizer sources and land-use patterns, analyzed the contributions of key environmental factors to the occurrence of antibiotics and ARGs in agricultural soils, and highlighted the potential ecological risk of typical antibiotics and the relationship between ARGs and mobile genetic elements (MGEs). Our results showed that cattle manure, chicken manure, swine manure, and sewage sludge were the primary pollution sources of antibiotics and ARGs in agricultural soils, and sulfonamides, tetracyclines, fluoroquinolones, and their corresponding ARGs were the main pollution types. Land-use type, soil, and climatic factors affected antibiotics concentration and ARG abundances. MGEs play a vital role in promoting the dissemination of ARGs, especially the sul1 gene is closely related to intI1. In conclusion, our findings and future research exploring these topics will contribute to better management of antibiotic and ARG contamination in agricultural soils and their risk to human health. [ABSTRACT FROM AUTHOR]

Background: Enteroccocus spp. are human opportunistic pathogens causing a variety of serious and life-threating infections in humans, including urinary tract infection, endocarditis, skin infection and bacteraemia. Farm animals and direct contact with them are important sources of Enterococcus faecalis (EFA) and Enterococcus faecium (EFM) infections among farmers, veterinarians and individuals working in breeding farms and abattoirs. The spread of antibiotic-resistant strains is one of the most serious public health concerns, as clinicians will be left without therapeutic options for the management of enterococcal infections. The aim of the study was to evaluate the occurrence and antimicrobial susceptibility of EFA and EFM strains isolated from a pig farm environment and to determine the biofilm formation ability of identified Enterococcus spp. strains. Results: A total numer of 160 enterococcal isolates were obtained from 475 samples collected in total (33.7%). Among them, 110 of genetically different strains were identified and classified into EFA (82; 74.5%) and EFM (28; 25.5%). Genetic similarity analysis revealed the presence of 7 and 1 clusters among the EFA and EFM strains, respectively. The highest percentage of EFA strains (16; 19.5%) was resistant to high concentrations of gentamicin. Among the EFM strains, the most frequent strains were resistant to ampicillin and high concentrations of gentamicin (5 each; 17.9%). Six (7.3%) EFA and 4 (14.3%) EFM strains showed vancomycin resistance (VRE - Vancomycin-Resistant Enterococcus). Linezolid resistance was found in 2 strains of each species. The multiplex PCR analysis was performed to identify the vancomycin resistant enterococci. vanB, vanA and vanD genotypes were detected in 4, 1 and 1 EFA strains, respectively. Four EFA VRE-strains in total, 2 with the vanA and 2 with the vanB genotypes, were identified. The biofilm analysis revealed that all vancomycin-resistant E. faecalis and E. faecium strains demonstrated a higher biofilm-forming capacity, as compared to the susceptible strains. The lowest cell count (5.31 log CFU / cm2) was reisolated from the biofilm produced by the vancomycin-sensitive strain EFM 2. The highest level of re-isolated cells was observed for VRE EFA 25 and VRE EFM 7 strains, for which the number was 7 log CFU / cm2 and 6.75 log CFU / cm2, respectively. Conclusions: The irrational use of antibiotics in agriculture and veterinary practice is considered to be one of the key reasons for the rapid spread of antibiotic resistance among microorganisms. Owing to the fact that piggery environment can be a reservoir of antimicrobial resistance and transmission route of antimicrobial resistance genes from commensal zoonotic bacteria to clinical strains, it is of a great importance to public health to monitor trends in this biological phenomenon. [ABSTRACT FROM AUTHOR]

Streptococcus uberis is a major causative agent of bovine mastitis, an inflammation of the mammary gland with substantial economic consequences. To reduce antibiotic use in animal agriculture, alternative strategies to treat or prevent mastitis are being investigated. Bovine-associated non-aureus staphylococci are proposed in that respect due to their capacity to inhibit the in vitro growth of S. uberis. We demonstrate that priming the murine mammary gland with Staphylococcus chromogenes IM reduces S. uberis growth in comparison with non-primed glands. The innate immune system is activated by increasing IL-8 and LCN2, which may explain this decreased growth. [ABSTRACT FROM AUTHOR]

Veterinary antibiotics (VAs) administered to livestock are introduced into the soil through livestock manure and compost. These antibiotics can run off to surface water or leach into groundwater during rainfall, causing problems such as antibiotic contamination or the occurrence of antibiotic-resistant bacteria. In this study, an analytical method for detecting four classes of VAs (penicillin, tetracyclines, macrolides, and sulfonamides) in river water and soil was developed, and the occurrence of residual antibiotics in the agricultural environment was monitored. Soil samples were extracted with the McIlvain buffer solution and pretreatment was conducted using solid-phase extraction, followed by liquid chromatography-tandem mass spectrometry to quantify target VAs. The results of this study showed that the recovery ranged from 62 to 121% in river water and 40.2–149.3% in soil. Among the other VAs, amoxicillin and spiramycin were observed to have low recoveries in all the samples. The method detection limit (MDL) was calculated in the range of 2.1–12.3 ng L−1 in river water and 1.2–13.2 ng kg−1 in soil, and the limit of quantification was 6.6–39.2 ng L−1 and 4.0–42.0 ng kg−1, respectively. This optimal method was then applied to measure the residual concentrations of VAs in river water, sediment, and soil samples around the Muhan watershed in Korea. A total of seven antibiotics were detected, and their concentrations ranged from 0.014 to 0.309 μg L−1in river water, and 1.45–9.04 μg kg−1 in sediment and arable soil. This method can be used to screen VAs in river water and soil and is expected to be used as primary data for examining the occurrence and fate of antibiotics in agricultural environments. [ABSTRACT FROM AUTHOR]

The discovery of novel chiral selectors always fascinates us. This work describes the chiral separation performances of a new chiral selector (kasugamycin, KAS) in capillary electrophoresis (CE) for six pairs of stereoisomers, including ephedrine and pseudoephedrine, quinine and quinidine, cinchonine and cinchonidine, and amlodipine, promethazine and ofloxacin enantiomers. Kasugamycin, an aminoglycoside antibiotic in agriculture, shows significant biological activity against rice blast with low toxicity. As it turns out, this new chiral selector possesses good CE compatibility and stereoselectivity towards model analytes. In this work, we systematically investigated several separation parameters including kasugamycin concentration, buffer pH, separation voltage and the composition of the buffer solution. A detailed discussion about the chiral recognition mechanism was made based on Statistical Product and Service Solution (SPSS) analysis, NMR experiments (1D and 2D) and molecular modeling. This is the first time that kasugamycin is utilized as a chiral selector in CE, and the development of new chiral selectors from agricultural or veterinary antibiotics deserves more attention. [ABSTRACT FROM AUTHOR]

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The necessity for the discovery of innovative antimicrobials to treat life-threatening diseases has increased as multidrug-resistant bacteria has spread. Due to antibiotics' availability over the counter in many nations, antibiotic resistance is linked to overuse, abuse, and misuse of these drugs. The World Health Organization (WHO) recognized 12 families of bacteria that present the greatest harm to human health, where options of antibiotic therapy are extremely limited. Therefore, this paper reviews possible new ways for the development of novel classes of antibiotics for which there is no pre-existing resistance in human bacterial pathogens. By utilizing research and technology such as nanotechnology and computational methods (such as in silico and Fragment-based drug design (FBDD)), there has been an improvement in antimicrobial actions and selectivity with target sites. Moreover, there are antibiotic alternatives, such as antimicrobial peptides, essential oils, anti-Quorum sensing agents, darobactins, vitamin B6, bacteriophages, odilorhabdins, 18β-glycyrrhetinic acid, and cannabinoids. Additionally, drug repurposing (such as with ticagrelor, mitomycin C, auranofin, pentamidine, and zidovudine) and synthesis of novel antibacterial agents (including lactones, piperidinol, sugar-based bactericides, isoxazole, carbazole, pyrimidine, and pyrazole derivatives) represent novel approaches to treating infectious diseases. Nonetheless, prodrugs (e.g., siderophores) have recently shown to be an excellent platform to design a new generation of antimicrobial agents with better efficacy against multidrug-resistant bacteria. Ultimately, to combat resistant bacteria and to stop the spread of resistant illnesses, regulations and public education regarding the use of antibiotics in hospitals and the agricultural sector should be combined with research and technological advancements. [ABSTRACT FROM AUTHOR]

The antimicrobial properties silver nanoparticles (AgNPs) have been well documented against a range of bacterial, fungal and vii-al pathogens. Due to their size and surface area, AgNPs provide a sustained release of silver ions. resulting in efficacy at low concentrations. This precise control over the antimicrobial agent's dosage minimizes environmental impact. Consequently, AgNPs have emerged as an attractive alternative to antibiotics in the treatment of agricultural pathogens. Numerous studies have demonstrated the susceptibility of bacterial plant pathogens to AgNPs, prompting further evaluations for potential field applications. In order to determine the stability of AgNPs iii environmental conditions, we evaluated the effect of UV irradiation on the antimicrobial properties of AgNPs against Sinorhizobium nieliloti and Agrobacterium tumetaciens, analogs of the citrus greening pathogen Candidatus Liberibacter asciancus. Previous research has shown that UV irradiation of AgNPs produced hydroxyl radicals which increased the antimicrobial activity of AgNPs when tested against Escherichia coli. For our analysis, AgNPs solutions were exposed to UV light from a distance of 5 cm for times of 0, 30,60 seconds. and 3 and 30 minutes. A significant increase in antimicrobial activity was observed for the 30-minute treatments. S. meliloti growth decreased from 1.97 x 106 CFU/mi to 1. 87 x 105 CFU/ml. a change of approximated 90%. Exposure to UV light is a major concern for any type of treatment applied in the field, and AgNPs show significant increase in efficacy under UV exposure, further supporting these as good candidates to control agricultural pathogens. [ABSTRACT FROM AUTHOR]

Antibiotics enter into agricultural land, via manure application or wastewater irrigation. The practices of using untreated wastewater in the agricultural system help in the bioaccumulation of antibiotics in vegetables and other crops. Exposure to the bioaccumulated antibiotics poses serious health risks to ecosystem and human. In this study, the prevalence of two fluoroquinolones (levofloxacin and ciprofloxacin), their bioaccumulation in five crops (Daucus carota L., Pisum sativum L., Raphanus raphanistrum L., Lactuca sativa L., Spinacia oleracea L.), and associated human health risks were investigated. Lettuce showed highest bioaccumulation of levofloxacin (LEV) (12.66 μg kg−1) and carrot showed high bioaccumulation of ciprofloxacin (CIP) (13.01 μg kg−1). In roots, bioconcentration factor (BCFroot) was observed to be relatively high in radish (LEV 0.24–0.43, CIP 0.32–0.49) and observed to be lower in spinach (LEV 0.05–0.13, CIP 0.12–0.19). The translocation factor (TF) for LEV and CIP was generally >1 for all five crops under all treatment. The final transfer and distribution of LEV and CIP in the edible parts of the crops were as follows: leaves > shoots > roots for both antibiotics. Risk quotient of both LEV and CIP in current study is found to be in between 0.018 and 0.557 and shows a medium risk (0.1 to 1) to human health due the discharge of untreated wastewater into the fields. However, our study reports that both antibiotics do accumulate in the edible plant parts; therefore, it poses potential risks to human health. [ABSTRACT FROM AUTHOR]