# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 7060 | 0 | 0.9862 | Antibiotic resistance partitioning during on-farm manure separation and high temperature rotary drum composting. Manure application as fertilizer can increase environmental exposure risk, as antibiotics, antibiotic resistance bacteria (ARB), and antibiotic resistant genes (ARGs) can be transmitted to agricultural fields, and adjacent natural systems. Understanding how specific antibiotics and ARGs respond within different manure fractions during on-farm management is limited. The study objective was to conduct a mass flow analysis determining the fate of antibiotic resistance factors (antibiotics, ARGs, and ARB) through solid-liquid separation, with the solid fraction continuing through a bedding recovery unit (BRU) via high temperature rotary composting for use of the manure solids as dairy cow bedding. The results show that most of the manure mass containing the antibiotic resistance factors went untreated following solid-liquid separation, with 95% of the mass leaving the separator as a liquid and pumped to a storage lagoon for field application and 5% proceeding to BRU processing. The tetracyclines and tulathromycin sorbed to the manure solids, while the beta lactams, ampicillin, and benzylpenicilloic acid were only found in the liquid fraction. The removal of antibiotic residuals during the BRU composting was insignificant, yet 40%-73% of the antibiotics were in the liquid fraction. The BRU composting was 100% effective in removing the ARB examined. Five of the eight ARGs (intl1, sul1, tetQ, tetX, and tetM) had significant reduction (>95%) following the BRU composting treatment. While the three other ARGs (tetW, ermB, and bla2) remained constant despite treatment. This study highlighted the importance of examining manure management from a mass balance perspective and understanding antibiotic resistance risk factors. | 2025 | 39617587 |
| 7073 | 1 | 0.9862 | Fecal Indicator Bacteria and Antibiotic Resistance Genes in Storm Runoff from Dairy Manure and Compost-Amended Vegetable Plots. Given the presence of antibiotics and resistant bacteria in livestock manures, it is important to identify the key pathways by which land-applied manure-derived soil amendments potentially spread resistance. The goal of this field-scale study was to identify the effects of different types of soil amendments (raw manure from cows treated with cephapirin and pirlimycin, compost from antibiotic-treated or antibiotic-free cows, or chemical fertilizer only) and crop type (lettuce [ L.] or radish [ L.]) on the transport of two antibiotic resistance genes (ARGs; 1 and ) via storm runoff from six naturally occurring storms. Concurrent quantification of sediment and fecal indicator bacteria (FIB; and enterococci) in runoff permitted comparison to traditional agricultural water quality targets that may be driving factors of ARG presence. Storm characteristics (total rainfall volume, storm duration, etc.) significantly influenced FIB concentration (two-way ANOVA, < 0.05), although both effects from individual storm events (Kruskal-Wallis, < 0.05) and vegetative cover influenced sediment levels. Composted and raw manure-amended plots both yielded significantly higher 1 and B levels in runoff for early storms, at least 8 wk following initial planting, relative to fertilizer-only or unamended barren plots. There was no significant difference between 1 or B levels in runoff from plots treated with compost derived from antibiotic-treated versus antibiotic-free dairy cattle. Our findings indicate that agricultural fields receiving manure-derived amendments release higher quantities of these two "indicator" ARGs in runoff, particularly during the early stages of the growing season, and that composting did not reduce effects of ARG loading in runoff. | 2019 | 31589689 |
| 6790 | 2 | 0.9862 | Overlooked dissemination risks of antimicrobial resistance through green tide proliferation. Green tides, particularly those induced by Enteromorpha, pose significant environmental challenges, exacerbated by climate change, coastal eutrophication, and other anthropogenic impacts. More concerningly, these blooms may influence the spread of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) within ecosystems. However, the manner in which Enteromorpha blooms affect the distribution and spread of antimicrobial resistance (AMR) remains uncertain. This study investigated ARG profiles, dynamic composition, and associated health risks within the Enteromorpha phycosphere and surrounding seawater in typical bays (Jiaozhou, Aoshan, and Lingshan) in the South Yellow Sea. The Enteromorpha phycosphere exhibited significantly higher ARG abundance (p < 0.05) but lower diversity compared to the surrounding seawater. Source-tracking and metagenomic analyses revealed that the phycosphere was the main contributor to the resistome of surrounding seawater. Moreover, resistant pathogens, especially ESKAPE pathogens, with horizontal gene transfer (HGT) potential, were more abundant in the phycosphere than in the surrounding seawater. The phycosphere released high-risk ARGs to the surrounding seawater during Enteromorpha blooms, posing serious health and ecological AMR risks in marine environments. This study highlights the significant role of Enteromorpha blooms in ARG spread and associated risks, urging a reassessment of AMR burden from a public health perspective. | 2025 | 39488061 |
| 6926 | 3 | 0.9861 | Insights into the driving factors of vertical distribution of antibiotic resistance genes in long-term fertilized soils. The prevalence of antibiotic resistance genes (ARGs) in soils has aroused wide attention. However, the influence of long-term fertilization on the distribution of ARGs in different soil layers and its dominant drivers remain largely unknown. In this study, a total of 203 ARGs were analyzed in greenhouse vegetable soils (0-100 cm from a 13-year field experiment applied with different fertilizers (control, chemical fertilizer, organic manure, and mixed fertilizer). Compared with unfertilized and chemically fertilized soils, manure application significantly increased the abundance and alpha diversity of soil ARGs, where the assembly of ARG communities was strongly driven by stochastic processes. The distribution of ARGs was significantly driven by manure application within 60 cm, while it was insignificantly changed in soil below 60 cm under different fertilization regimes. The inter-correlations of ARGs with mobile genetic elements (MGEs) and microbiota were strengthened in manured soil, indicating manure application posed a higher risk for ARGs diffusion in subsurface soil. Bacteria abundance and MGEs directly influenced ARG abundance and composition, whereas soil depth and manure application indirectly influenced ARG abundance and composition by affecting antibiotics. These results strengthen our understanding of the long-term anthropogenic influence on the vertical distribution of soil ARGs and highlight the ecological risk of ARGs in subsurface soil induced by long-term manure application. | 2023 | 37247491 |
| 8120 | 4 | 0.9860 | Insight into the fate of antibiotic resistance genes and bacterial community in co-composting green tea residues with swine manure. Green tea residues (GTRs) are byproducts of tea production and processing, and this type of agricultural waste retains nutritious components. This study investigated the co-composting of GTRs with swine manure, as well as the effects of GTRs on antibiotic resistance genes (ARGs) and the bacterial community during co-composting. The temperature and C/N ratio indicate compost was mature after processing. The addition of GTRs effectively promoted the reduction in the abundances of most targeted ARGs (tet and sul genes), mobile genetic element (MGE; intI1), and metal resistance genes (MRGs; pcoA and tcrB). Redundancy analysis (RDA) showed that GTRs can reduce the abundance of MRGs and ARGs by reducing the bioavailability of heavy metals. Network analysis shows that Firmicutes and Actinobacteria were the main hosts of ARGs and ARGs, MGEs, and MRGs shared the same potential host bacteria. Adding GTRs during composting may reduce ARGs transmission through horizontal gene transfer (HGT). GTRs affected the bacterial community, thereby influencing the variations in the ARG profiles and reducing the potential risk associated with the compost product. | 2020 | 32310121 |
| 7134 | 5 | 0.9860 | Elevated levels of antibiotic resistance in groundwater during treated wastewater irrigation associated with infiltration and accumulation of antibiotic residues. Treated wastewater irrigation (TWW) releases antibiotics and antibiotic resistance genes (ARGs) into the environment and might thus promote the dissemination of antibiotic resistance in groundwater (GW). We hypothesized that TWW irrigation increases ARG abundance in GW through two potential mechanisms: the contamination of GW with resistant bacteria and the accumulation of antibiotics in GW. To test this, the GW below a real-scale TWW-irrigated field was sampled for six months. Sampling took place before, during and after high-intensity TWW irrigation. Samples were analysed with 16S rRNA amplicon sequencing, qPCR of six ARGs and the class 1 integron-integrase gene intI1, while liquid chromatography tandem mass spectrometry was performed to detect antibiotic and pharmaceutical residues. Absolute abundance of 16S rRNA in GW decreased rather than increased during long-term irrigation. Also, the relative abundance of TWW-related bacteria did not increase in GW during long-term irrigation. In contrast, long-term TWW irrigation increased the relative abundance of sul1 and intI1 in the GW microbiome. Furthermore, GW contained elevated concentrations of sulfonamide antibiotics, especially sulfamethoxazole, to which sul1 confers resistance. Total sulfonamide concentrations in GW correlated with sul1 relative abundance. Consequently, TWW irrigation promoted sul1 and intI1 dissemination in the GW microbiome, most likely due to the accumulation of drug residues. | 2022 | 34555761 |
| 8123 | 6 | 0.9860 | The effect of bulk-biochar and nano-biochar amendment on the removal of antibiotic resistance genes in microplastic contaminated soil. Biochar amendment has significant benefits in removing antibiotic resistance genes (ARGs) in the soil. Nevertheless, there is little information on ARGs removal in microplastic contaminated soil. Herein, a 42-day soil microcosm experiment were carried out to study how two coconut shell biochars (bulk- and nano-size) eliminate soil ARGs with/without microplastic presence. The results showed that microplastic increased significantly the numbers and abundances of ARGs in soil at 14d of cultivation. And, two biochars amendment effectively inhibited soil ARGs spread whether or not microplastic was present, especially for nano-biochar which had more effective removal compared to bulk-biochar. However, microplastic weakened soil ARGs removal after applying same biochar. Two biochars removed ARGs through decreasing horizontal gene transfer (HGT) of ARGs, potential host-bacteria abundances, some bacteria crowding the eco-niche of hosts and promoting soil properties. The adverse effect of microplastic on ARGs removal was mainly caused by weakening mobile genetic elements (MGEs) removal, and by changing soil properties. Structural equation modeling (SEM) analysis indicated that biochar's effect on ARGs profile was changed by its size and microplastic presence through altering MGEs abundances. These results highlight that biochar amendment is still an effective method for ARGs removal in microplastic contaminated soil. | 2024 | 37907163 |
| 7216 | 7 | 0.9859 | Tracking antibiotic resistance through the environment near a biosolid spreading ground: Resistome changes, distribution, and metal(loid) co-selection. The application of urban wastewater treatment plants (WWTPs) products to agricultural lands has contributed to the rising level of antibiotic resistance and drawn a critical public health concern. It has not been thoroughly investigated at which spatial scales a biosolid applied area as a potentially predominant source affects surrounding soil resistomes. This study investigated distribution and impact of WWTP biosolids treated with anaerobic digestion on an agricultural area. Heterotrophic plate counts (HPCs) and quantitative polymerase chain reaction (qPCR) were performed for detection of selected antibiotic-resistant bacteria (ARB), selected antibiotic resistance genes (ARGs), intI1 genes, and 16S rRNA genes. Biosolid samples contained significantly higher levels of selected ARGs than the raw agricultural soils (p < 0.05). The average relative abundances of intI1, sul1, bla(SHV), and ermB genes were significantly higher in biosolid-amended soils than nearby agricultural soils (p < 0.05). Spatial interpolation analysis of relative gene abundances of intI1, sul1, sul2, and tetW across the studied area further indicated directional trends towards the northwest and southeast directions, highlighting possible airborne spread. Concentrations of Co, Cu, Ni, and Fe were found to be significantly and positively correlated with relative abundances of intI1, sul1, and tetW genes (p < 0.05). The resistance ratios of culturable antibiotic-resistant bacteria in agricultural soils with biosolid amendments were generally identical to those without biosolid amendments. This study will advance the understanding of the antibiotic resistome in agricultural soils impacted by long-term waste reuse and inform the evaluation strategies for future biosolids application and management. | 2022 | 35121038 |
| 6924 | 8 | 0.9858 | Diversity of antibiotic resistance genes in soils with four different fertilization treatments. Although the enrichment of resistance genes in soil has been explored in recent years, there are still some key questions to be addressed regarding the variation of ARG composition in soil with different fertilization treatments, such as the core ARGs in soil after different fertilization treatments, the correlation between ARGs and bacterial taxa, etc. For soils after different fertilization treatments, the distribution and combination of ARG in three typical fertilization methods (organic fertilizer alone, chemical fertilizer alone, and conventional fertilizer) and non-fertilized soils were investigated in this study using high-throughput fluorescence quantitative PCR (HT-qPCR) technique. The application of organic fertilizers significantly increased the abundance and quantity of ARGs and their subtypes in the soil compared to the non-fertilized soil, where sul1 was the ARGs specific to organic fertilizers alone and in higher abundance. The conventional fertilizer application also showed significant enrichment of ARGs, which indicated that manure addition often had a more decisive effect on ARGs in soil than chemical fertilizers, and three bacteria, Pseudonocardia, Irregularibacter, and Castllaniella, were the key bacteria affecting ARG changes in soil after fertilization. In addition, nutrient factors and heavy metals also affect the distribution of ARGs in soil and are positively correlated. This paper reveals the possible reasons for the increase in the number of total soil ARGs and their relative abundance under different fertilization treatments, which has positive implications for controlling the transmission of ARGs through the soil-human pathway. | 2023 | 37928655 |
| 6923 | 9 | 0.9857 | Soil types influence the fate of antibiotic-resistant bacteria and antibiotic resistance genes following the land application of sludge composts. Sewage sludge was generally considered a significant reservoir of antibiotic resistance genes (ARGs) and could enter agricultural systems as fertilizer after composting. Soil types and the discrepancy of sludge composts could have influenced the fate of antibiotic-resistant bacteria (ARB) following the land application of sludge composts, which deserved to be clarified. Thus, the fate of ARB and ARGs following the land application of three types of sludge composts (A, B, and C) to three different soils (red soil, loess, and black soil) was investigated. The results showed that tetX, which was enriched the most during composting, did not affect the soil resistome, whereas tetG did. Soil types influenced the dynamics of ARB and ARGs significantly, whereas no significant difference was observed among compost types. The advantage of reducing ARGs during the composting process in compost B did not extend to land application. Land application of composts influenced the microbial community significantly at the early stage, but the microbial community returned to the control pattern gradually. Changes in the microbial community contributed more to the dynamics of ARGs in red and black soil compared with other factors, including co-selection from heavy metals, horizontal gene transfer, biomass and environmental factors, whereas horizontal gene transfer, reflected by intI1 levels, contributed the most in loess. | 2018 | 29793114 |
| 7000 | 10 | 0.9857 | Animal manures application increases the abundances of antibiotic resistance genes in soil-lettuce system associated with shared bacterial distributions. An increasing amount of animal manures is being used in agriculture, and the effect of animal manures application on the abundance of antibiotics resistance genes (ARGs) in soil-plant system has attracted widespread attention. However, the impacts of animal manures application on the various types of bacterial distribution that occur in soil-lettuce system are unclear. To address this topic, the effects of poultry manure, swine manure or chemical fertilizer application on ARG abundance and the distribution of shared bacteria were investigated in this study. In a lettuce pot experiment, 13 ARGs and 2 MGEs were quantified by qPCR, and bacterial communities in the soil, lettuce endosphere and lettuce phyllosphere were analysed by 16S rRNA sequence analysis. The results showed that the application of poultry or swine manure significantly increased ARG abundance in the soil, a result attributed mainly to increases in the abundances of tetG and tetC. The application of poultry manure, swine manure and chemical fertilizer significantly increased ARG abundance in the lettuce endosphere, and tetG abundance was significantly increased in the poultry and swine manure groups. However, animal manures application did not significantly increase ARG abundance in the lettuce phyllosphere. Flavobacteriaceae, Sphingomonadaceae and 11 other bacterial families were the shared bacteria in the soil, lettuce endosphere, and phyllosphere. The Streptomycetaceae and Methylobacteriaceae were significantly positively correlated with intI1 in both the soil and endosphere. Chemical fertilizer application increased both the proportions of Sphingomonadaceae and tetX abundance, which were positively correlated in the endosphere. Comamonadaceae and Flavobacteriaceae were not detected in the lettuce endosphere under swine manure application. Cu was related to Flavobacteriaceae in the lettuce endosphere. Overall, poultry and swine manure application significantly increased ARG abundance in the soil-lettuce system, which might be due to the shared bacterial distribution. | 2021 | 34004530 |
| 6991 | 11 | 0.9857 | Distribution and drivers of antibiotic resistance genes in brackish water aquaculture sediment. Brackish water aquaculture has brought numerous economic benefits, whereas anthropogenic activities in aquaculture may cause the dissemination of antibiotic resistance genes (ARGs) in brackish water sediments. The intricate relationships between environmental factors and microbial communities as well as their role in ARGs dissemination in brackish water aquaculture remain unclear. This study applied PCR and 16S sequencing to identify the variations in ARGs, class 1 integron gene (intI1) and microbial communities in brackish water aquaculture sediment. The distribution of ARGs in brackish water aquaculture sediment was similar to that in freshwater aquaculture, and the sulfonamide resistance gene sul1 was the indicator of ARGs. Proteobacteria and Firmicutes were the dominant phyla, and Paenisporosarcina (p_ Firmicutes) was the dominant genus. The results of correlation, network and redundancy analysis indicated that the microbial community in the brackish water aquaculture sediment was function-driven. The neutral model and variation partitioning analysis were used to verify the ecological processes of the bacterial community. The normalized stochasticity ratio showed that pond bacteria community was dominated by determinacy, which was affected by aquaculture activities. The total nitrogen and organic matter influenced the abundance of ARGs, while Proteobacteria and Thiobacillus (p_Proteobacteria) were the key antibiotic-resistant hosts. Our study provides insight into the prevalence of ARGs in brackish water aquaculture sediments, and indicates that brackish water aquaculture is a reservoir of ARGs. | 2023 | 36436623 |
| 7241 | 12 | 0.9856 | In situ analysis of antibiotic resistance genes in anaerobically digested dairy manure and its subsequent disposal facilities. The metagenomic and quantitative polymerase chain reaction approaches were combined to evaluate the profiles of ARGs and plasmids in anaerobically digested dairy manure in situ and reveal the persistence and elevation of typical ARGs and plasmids in its subsequent disposal facilities in CAFOs, respectively. Our results indicated that the typical ARGs and plasimd were mainly sul2, mefa, tetm-01, tetm-02, tetw, aph3iiia, and clostridioides difficile strain 12,038 plasmid unnamed in CAFOs, some of which greatly enriched in AD residue after its storage, especially sul1 and sul2. Meantime, the AD slurry recycling introduced the bacteria carrying ARGs into soil, especially Romboutsia genus, which greatly enriched sul2, tetm-01, tetm-02, aphiiia, and mefa. In the present study, ARGs occurrence, persistence and distribution were understood through in situ analysis of their profiles during dairy manure AD treatment and subsequent disposals in CAFOs, which are helpful for controlling the potential environmental risks from dairy manure recycling. | 2021 | 33894444 |
| 7215 | 13 | 0.9856 | High-throughput qPCR profiling of antimicrobial resistance genes and bacterial loads in wastewater and receiving environments. Wastewater treatment plants (WWTPs) are hot spots for the acquisition and spread of antimicrobial resistance (AMR). This regional-based study quantified antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and bacteria in hospital and community-derived wastewater and receiving environments, using high-throughput qPCR (HT-qPCR). This is the first study to apply Resistomap's Antibiotic Resistance Gene Index (ARGI) as a standardised metric to find the overall AMR level across different WWTPs. ARGI of WWTPs ranged from 2.0 to 2.3, indicating higher relative ARG levels than the mean European ARGI of 2.0, but lower than the global mean of 2.4. The highest diversity and abundance of ARGs were observed in untreated hospital and community wastewater. The reduction of total ARGs during wastewater treatment (0.2-2 logs) and bacteria (0.3-1.5 logs) varied spatio-temporally across the WWTPs. Despite a decrease in ARG and bacterial abundance in treated effluents, substantial loads were still released into receiving environments. Notably, ARG levels in coastal sediments were comparable to those in untreated wastewater, and most ARGs were shared between wastewater and receiving environments, highlighting the impact of wastewater discharge on these ecosystems. Sewage outfall exposure increased ARGs in shellfish, emphasising risks to shellfish hygiene. This study provides evidence to inform policymaking, emphasising advanced wastewater treatment methods and combined sewer overflow (CSO) management to mitigate ARG release, protecting water users and the food chain. | 2025 | 40127809 |
| 6917 | 14 | 0.9856 | Response characteristics of antibiotic resistance genes and bacterial communities during agricultural waste composting: Focusing on biogas residue combined with biochar amendments. This research investigated biogas residue and biochar addition on antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and changes in bacterial community during agricultural waste composting. Sequencing technique investigated bacterial community structure and ARGs, MGEs changes. Correlations among physicochemical factors, ARGs, MGEs, and bacterial community structure were determined using redundancy analysis. Results confirmed that biochar and biogas residue amendments effectively lowered the contents of ARGs and MGEs. The main ARGs detected was sul1. Proteobacteria and Firmicutes were the main host bacteria strongly associated with the dissemination of ARGs. The dynamic characteristics of the bacterial community were strongly correlated with pile temperature and pH (P < 0.05). Redundancy and network analysis revealed that nitrate, intI1, and Firmicutes mainly affected the in ARGs changes. Therefore, regulating these key variables would effectively suppress the ARGs spread and risk of compost use. | 2023 | 36657587 |
| 6957 | 15 | 0.9856 | Untreated swine wastes changed antibiotic resistance and microbial community in the soils and impacted abundances of antibiotic resistance genes in the vegetables. Animal waste fertilization is a traditional agricultural practice, which may have adverse effects to soil ecosystem. However, the side-effects of animal waste fertilization on vegetables are less studied. Here we selected a swine farming village for investigation with a nearby village without swine farming as comparison. In the swine farming village, the farmers use untreated swine manure and wastewater as fertilizers for vegetable cultivation. In the reference village, the farmers mainly use commercial organic fertilizers. The objective of this study is to assess the impacts of untreated swine waste fertilization on both soils and vegetables in terms of antibiotics, antibiotic resistance genes (ARGs) and bacterial microbial communities. The results indicate that untreated swine waste fertilization caused both antibiotic and ARG contaminations and changed the microbial community compositions in the soils. Varieties of tetracyclines and related resistance genes were detected especially in swine wastewater treated soils. The soil quality was impacted with the relations to bacterial abundances and microbial geochemical functions. Proteobacteria and Bacteroidetes were prevalent and positively correlated to ARGs in soils, indicating they were potential antibiotic resistant bacteria. Antibiotics and ARGs were detected in vegetables of both villages. The abundances of ARGs were relatively higher in some vegetable samples of the swine farming village than the reference village. In addition, intracellular parasites Rickettsiales with positive correlation to ARGs were prevalent in some vegetables of swine farming village, indicating potential health risks through eating contaminated vegetables. The results of this study suggest that untreated swine wastes may cause adverse effects to not only agricultural soils but also associated vegetables. | 2020 | 32615438 |
| 6921 | 16 | 0.9856 | Impacts of Chemical and Organic Fertilizers on the Bacterial Communities, Sulfonamides and Sulfonamide Resistance Genes in Paddy Soil Under Rice-Wheat Rotation. The responses of sulfonamides, sulfonamide-resistance genes (sul) and soil bacterial communities to different fertilization regimes were investigated by performing a field experiment using paddy soil with no fertilizer applied, chemical fertilizer applied, organic fertilizer applied, and combination of chemical and organic fertilizer applied. Applying organic fertilizer increased the bacterial community diversity and affected the bacterial community composition. Eutrophic bacteria (Bacteroidetes, Gemmatimonadetes, and Proteobacteria) were significantly enriched by applying organic fertilizer. It was also found organic fertilizer application increased sulfamethazine content and the relative abundances of sul1 and sul2 in the soil. In contrast, applying chemical fertilizer significantly increased the abundance of Nitrospirae, Parcubacteria, and Verrucomicrobia and caused no obvious changes on sul. Correlation analysis indicated that sul enrichment was associated with the increases in sulfamethazine content and potential hosts (e.g., Novosphingobium and Rhodoplanes) population. The potential ecological risks of antibiotics in paddy soil with organic fertilizer applied cannot be ignored. | 2022 | 36547725 |
| 7358 | 17 | 0.9856 | Global dispersal and potential sources of antibiotic resistance genes in atmospheric remote depositions. Antibiotic resistance has become a major Global Health concern and a better understanding on the global spread mechanisms of antibiotic resistant bacteria (ARB) and intercontinental ARB exchange is needed. We measured atmospheric depositions of antibiotic resistance genes (ARGs) by quantitative (q)PCR in rain/snow collected fortnightly along 4 y. at a remote high mountain LTER (Long-Term Ecological Research) site located above the atmospheric boundary layer (free troposphere). Bacterial composition was characterized by 16S rRNA gene sequencing, and air mass provenances were determined by modelled back trajectories and rain/snow chemical composition. We hypothesize that the free troposphere may act as permanent reservoir and vector for ARB and ARGs global dispersal. We aimed to i) determine whether ARGs are long-range intercontinental and persistently dispersed through aerosols, ii) assess ARGs long-term atmospheric deposition dynamics in a remote high mountain area, and iii) unveil potential diffuse ARGs pollution sources. We showed that the ARGs sul1 (resistance to sulfonamides), tetO (resistance to tetracyclines), and intI1 (a proxy for horizontal gene transfer and anthropogenic pollution) were long-range and persistently dispersed in free troposphere aerosols. Major depositions of tetracyclines resistance matched with intensification of African dust outbreaks. Potential ARB mostly traced their origin back into agricultural soils. Our study unveils that air masses pathways are shaping ARGs intercontinental dispersal and global spread of antibiotic resistances, with potential predictability for interannual variability and remote deposition rates. Because climate regulates aerosolization and long-range air masses movement patterns, we call for a more careful evaluation of the connections between land use, climate change and ARB long-range intercontinental dispersal. | 2022 | 35016024 |
| 6952 | 18 | 0.9855 | Modeling the vertical transport of antibiotic resistance genes in agricultural soils following manure application. Antibiotic resistance genes (ARGs) may be introduced to agricultural soil through the land application of cattle manure. During a rainfall event, manure-borne ARGs may infiltrate into subsurface soil and leach into groundwater. The objective of this study was to characterize and model the vertical transport of manure-borne ARGs through soil following the land application of beef cattle manure on soil surface. In this study, soil column experiments were conducted to evaluate the influence of manure application on subsurface transport of four ARGs: erm(C), erm(F), tet(O) and tet(Q). An attachment-detachment model with the decay of ARGs in the soil was used to simulate the breakthrough of ARGs in leachates from the control column (without manure) and treatment (with manure) soil columns. Results showed that the first-order attachment coefficient (k(a)) was five to six orders of magnitude higher in the treatment column than in the control column. Conversely, the first-order detachment and decay coefficients (k(d) and μ(s)) were not significantly changed due to manure application. These findings suggest that in areas where manure is land-applied, some manure-borne bacteria-associated ARGs will be attached to the soil, instead of leaching to groundwater in near terms. | 2021 | 34087637 |
| 8097 | 19 | 0.9855 | Fate of antibiotic resistance genes in farmland soil applied with three different fertilizers during the growth cycle of pakchoi and after harvesting. The increasing prevalence of antibiotic resistance genes (ARGs) in the soil environment poses a serious threat to crop safety and even public health. In this study, the fate of ARGs in the soil was investigated during the growth period of pakchoi and after harvesting with the application of different kinds of fertilizers. The result showed that increasing rate of soil ARGs during the growth period of pakchoi followed the order of composted manure > commercial fertilizer > mineral fertilizer. After harvesting, soil ARGs abundance treated with mineral fertilizer, commercial fertilizer or composted manure significantly increased by 0.63, 3.19 and 8.65 times (p < 0.05), respectively, compared with the non-fertilized soil. The ARGs abundance in the pakchoi treated with composted manure was significantly higher than that of treatments with mineral fertilizer and commercial organic fertilizer. These findings indicated the application of composted pig manure would significantly increase the pollution load of ARGs in farmland soil and plant, and also promote the proliferation of farmland ARGs. Principal component analysis suggested that bacterial communities might have a significant influence on ARGs changes during the growth period of pakchoi. Network analysis further indicated ARGs changes may be mainly related to their host bacteria (including Gammaproteobacteria, Flavobacteriia and Bacilli). The results provided a proper method and useful information on reducing transmission risk of ARGs and control the propagation of ARGs in agricultural activities. | 2021 | 33865023 |