# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 6921 | 0 | 0.9831 | 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 |
| 8123 | 1 | 0.9825 | 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 |
| 7057 | 2 | 0.9824 | Enrichment of antibiotic resistance genes in soil receiving composts derived from swine manure, yard wastes, or food wastes, and evidence for multiyear persistence of swine Clostridium spp. The impact of amendment with swine manure compost (SMC), yard waste compost (YWC), or food waste compost (FWC) on the abundance of antibiotic resistance genes in soil was evaluated. Following a commercial-scale application of the composts in a field experiment, soils were sampled periodically for a decade, and archived air-dried. Soil DNA was extracted and gene targets quantified by qPCR. Compared with untreated control soil, all 3 amendment types increased the abundance of gene targets for up to 4 years postapplication. The abundance of several gene targets was much higher in soil amended with SMC than in soil receiving either YWC or FWC. The gene target ermB remained higher in the SMC treatment for a decade postapplication. Clostridia were significantly more abundant in the SMC-amended soil throughout the decade following application. Eight percent of Clostridium spp. isolates from the SMC treatment carried ermB. Overall, addition of organic amendments to soils has the potential to increase the abundance of antibiotic resistance genes. Amendments of fecal origin, such as SMC, will in addition entrain bacteria carrying antibiotic resistance genes. Environmentally recalcitrant clostridia, and the antibiotic resistance genes that they carry, will persist for many years under field conditions following the application of SMC. | 2018 | 29342372 |
| 8120 | 3 | 0.9824 | 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 |
| 6926 | 4 | 0.9824 | 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 |
| 7073 | 5 | 0.9822 | 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 |
| 8097 | 6 | 0.9822 | 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 |
| 8110 | 7 | 0.9822 | Removal of chlortetracycline and antibiotic resistance genes in soil by earthworms (epigeic Eisenia fetida and endogeic Metaphire guillelmi). The impacts of two ecological earthworms on the removal of chlortetracycline (CTC, 0.5 and 15 mg kg(-1)) and antibiotic resistance genes (ARGs) in soil were explored through the soil column experiments. The findings showed that earthworm could significantly accelerate the degradation of CTC and its metabolites (ECTC) in soil (P < 0.05), with epigeic Eisenia fetida promoting degradation rapidly and endogeic Metaphire guillelmi exhibiting a slightly better elimination effect. Earthworms alleviated the abundances of tetR, tetD, tetPB, tetG, tetA, sul1, TnpA, ttgB and intI1 in soil, with the total relative abundances of ARGs decreasing by 35.0-44.2% in earthworm treatments at the 28th day of cultivation. High throughput sequencing results displayed that the structure of soil bacteria community was modified apparently with earthworm added, and some possible CTC degraders, Aeromonas, Flavobacterium and Luteolibacter, were promoted by two kinds of earthworms. Redundancy analysis demonstrated that the reduction of CTC residues, Actinobacteria, Acidobacteria and Gemmatimonadetes owing to earthworm stimulation was responsible for the removal of ARGs and intI1 in soil. Additionally, intI1 declined obviously in earthworm treatments, which could weaken the risk of horizontal transmission of ARGs. Therefore, earthworm could restore the CTC-contaminated soil via enhancing the removal of CTC, its metabolites and ARGs. | 2021 | 33798888 |
| 7538 | 8 | 0.9821 | Short-term thermophilic treatment cannot remove tetracycline resistance genes in pig manures but exhibits controlling effects on their accumulation and spread in soil. In this work, a microcosm experiment was conducted to merely mimic thermophilic phase in aerobic composting with pig manures in order to explore: (i) the effect of thermophilic phase in composting on the abundances of tetracycline resistance genes (TRGs); and (ii) the impacts of the treated manures on the abundances of TRGs in soil. It was found that 4days of thermophilic process reduced the abundance of TRGs in pig manures by ∼1 lg unit compared to the samples without treatments, suggesting that other phases in composting may play significant roles in removal of TRGs. Once pig manures with thermophilic treatment were applied to soil, TRGs abundances decreased to the levels in unfertilized soil. With correlation analyses, it was concluded that pig manure derived tetracycline-resistant bacteria (TRB) and nutrients exerted different effects on TRGs abundances in soil. In conclusion, short-term thermophilic treatment cannot remove tetracycline resistance genes in pig manures but exhibits controlling effects on their accumulation and spread in soil. Nutrients enrichment in soil following manuring of treated pig manures, together with a large proportion of gram-positive TRB left in treated pig manures with less risk to TRGs spread, contributed to the controlling effects. | 2017 | 28715744 |
| 8115 | 9 | 0.9820 | Effects of reductive soil disinfestation on potential pathogens and antibiotic resistance genes in soil. Reductive soil disinfestation (RSD) is commonly employed for soil remediation in greenhouse cultivation. However, its influence on antibiotic resistance genes (ARGs) in soil remains uncertain. This study investigated the dynamic changes in soil communities, potential bacterial pathogens, and ARG profiles under various organic material treatments during RSD, including distillers' grains, potato peel, peanut vine, and peanut vine combined with charcoal. Results revealed that applying diverse organic materials in RSD significantly altered bacterial community composition and diminished the relative abundance of potential bacterial pathogens (P < 0.05). The relative abundance of high-risk ARGs decreased by 10.7%-30.6% after RSD treatments, the main decreased ARG subtypes were AAC(3)_Via, dfrA1, ErmB, lnuB, aadA. Actinobacteria was the primary host of ARGs and was suppressed by RSD. Soil physicochemical properties, such as total nitrogen, soil pH, total carbon, were crucial factors affecting ARG profiles. Our findings demonstrated that RSD treatment inhibited pathogenic bacteria and could be an option for reducing high-risk ARG proliferation in soil. | 2025 | 39306413 |
| 6923 | 10 | 0.9820 | 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 | 11 | 0.9820 | 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 |
| 8117 | 12 | 0.9820 | Composting of oxytetracycline fermentation residue in combination with hydrothermal pretreatment for reducing antibiotic resistance genes enrichment. Hydrothermal pretreatment can efficiently remove the residual antibiotics in oxytetracycline fermentation residue (OFR), but its effect on antibiotic resistance genes (ARGs) during composting remains unclear. This study compared the shifts in bacterial community and evolutions in ARGs and integrons during different composting processes of OFRs with and without hydrothermal pretreatment. The results demonstrated that hydrothermal pretreatment increased the bacterial alpha diversity at the initial phase, and increased the relative abundances of Proteobacteria and Actinobacteria but decreased that of Bacteroidetes at the final phase by inactivating mycelia and removing residual oxytetracycline. Composting process inevitably elevated the abundance and relative abundance of ARGs. However, the increase in ARGs was significantly reduced by hydrothermal pretreatment, because the removal of oxytetracycline decreased their potential host bacteria and inhibited their horizontal gene transfer. The results demonstrated that hydrothermal pretreatment is an efficient strategy to reduce the enrichment of ARGs during the OFR composting. | 2020 | 33099099 |
| 7059 | 13 | 0.9820 | Composting reduces the risks of antibiotic resistance genes in maize seeds posed by gentamicin fermentation waste. Using high-throughput quantitative PCR and next generation sequencing, the impact of land application of raw and composted gentamicin fermentation waste (GFW) on antibiotic resistance genes (ARGs) in maize seeds was studied in a three-year field trial. The raw and composted GFW changed both the bacterial community composition and the ARGs diversity in the maize seeds compared to non-amended controls and chemical fertilizer. The abundance of ARGs after raw GFW amendment was significantly higher than other treatments because of a high abundance of aadA1, qacEdeltal and aph(2')-Id-02; probably induced by gentamicin selection pressure in maize tissues. Meanwhile, the potential host of these three ARGs, pathogenic bacteria Tenacibaculum, also increased significantly in maize seeds after the application of raw GFW. But our result proved that composting could weaken the risk posed by GFW. We further reveal that the key biotic driver for shaping the ARG profiles in maize seeds is bacterial community followed by heavy metal resistance genes, and ARGs are more likely located on bacterial chromosomes. Our findings provide new insight into ARGs dispersal mechanism in maize seeds after long-term GFW application, demonstrate the potential benefits of composting the GFW to reduce risks as well as the potential efficient management method to GFW. | 2023 | 36736399 |
| 6924 | 14 | 0.9819 | 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 |
| 6917 | 15 | 0.9818 | 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 |
| 8058 | 16 | 0.9817 | Effects of biochars on the fate of antibiotics and their resistance genes during vermicomposting of dewatered sludge. It is currently still difficult to decrease the high contents of antibiotics and their corresponding antibiotic resistance genes (ARGs) in sludge vermicompost. To decrease the environmental risk of vermicompost as a bio-fertilizer, this study investigated the feasibility of biochar addition to decrease the levels of antibiotics and ARGs during vermicomposting of dewatered sludge. To achieve this, 1.25% and 5% of corncob and rice husk biochars, respectively, were added to sludge, which was then vermicomposted by Eisenia fetida for 60 days. The sludge blended with corncob biochar showed increased decomposition and humification of organic matter. Higher biochar concentration promoted both the number and diversity of bacteria, and differed dominant genera. The level of antibiotics significantly decreased as a result of biochar addition (P < 0.05), and tetracycline was completely removed. Relative to the control without addition of biochars, ermF and tetX genes significantly decreased with corncob biochar treatment (P < 0.05). Rice husk biochar (5%) could effectively decrease sul-1 and sul-2 genes in vermicompost (P < 0.05). However, the abundance of the intI-1 gene increased with biochar concentration. This study suggests that biochar addition can lessen the antibiotic and ARG pollution in sludge vermicompost, depending on the type and concentration of biochars. | 2020 | 32388093 |
| 6911 | 17 | 0.9816 | Linking bacterial life strategies with the distribution pattern of antibiotic resistance genes in soil aggregates after straw addition. Straw addition markedly affects the soil aggregates and microbial community structure. However, its influence on the profile of antibiotic resistance genes (ARGs), which are likely associated with changes in bacterial life strategies, remains unclear. To clarify this issue, a soil microcosm experiment was incubated under aerobic (WS) or anaerobic (AnWS) conditions after straw addition, and metagenomic sequencing was used to characterise ARGs and bacterial communities in soil aggregates. The results showed that straw addition shifted the bacterial life strategies from K- to r-strategists in all aggregates, and the aerobic and anaerobic conditions stimulated the growth of aerobic and anaerobic r-strategist bacteria, respectively. The WS decreased the relative abundances of dominant ARGs such as QnrS5, whereas the AnWS increased their abundance. After straw addition, the macroaggregates consistently exhibited a higher number of significantly altered bacteria and ARGs than the silt+clay fractions. Network analysis revealed that the WS increased the number of aerobic r-strategist bacterial nodes and fostered more interactions between r-and K-strategist bacteria, thus promoting ARGs prevalence, whereas AnWS exhibited an opposite trend. These findings provide a new perspective for understanding the fate of ARGs and their controlling factors in soil ecosystems after straw addition. ENVIRONMENTAL IMPLICATIONS: Straw soil amendment has been recommended to mitigate soil fertility degradation, improve soil structure, and ultimately increase crop yields. However, our findings highlight the importance of the elevated prevalence of ARGs associated with r-strategist bacteria in macroaggregates following the addition of organic matter, particularly fresh substrates. In addition, when assessing the environmental risk posed by ARGs in soil that receives crop straw, it is essential to account for the soil moisture content. This is because the species of r-strategist bacteria that thrive under aerobic and anaerobic conditions play a dominant role in the dissemination and accumulation of ARG. | 2024 | 38643583 |
| 8094 | 18 | 0.9816 | Additive quality influences the reservoir of antibiotic resistance genes during chicken manure composting. Aerobic composting is commonly used to dispose livestock manure and is an efficient way to reduce antibiotic resistance genes (ARGs). Here, the effects of different quality substrates on the fate of ARGs were assessed during manure composting. Results showed that the total relative abundances of ARGs and intI1 in additive treatments were lower than that in control, and high quality treatment with low C/N ratio and lignin significantly decreased the relative abundance of tetW, ermB, ermC, sul1 and sul2 at the end of composting. Additionally, higher quality treatment reduced the relative abundances of some pathogens such as Actinomadura and Pusillimonas, and some thermotolerant degrading-related bacteria comprising Pseudogracilibacillus and Sinibacillus on day 42, probably owing to the change of composting properties in piles. Structural equation models (SEMs) further verified that the physiochemical properties of composting were the dominant contributor to the variations in ARGs and they could also indirectly impact ARGs by influencing bacterial community and the abundance of intI1. Overall, these findings indicated that additives with high quality reduced the reservoir of antibiotic resistance genes of livestock manure compost. | 2021 | 34139628 |
| 8101 | 19 | 0.9816 | Enhanced removal of antibiotic resistance genes and mobile genetic elements during swine manure composting inoculated with mature compost. Livestock manure is a major source of antibiotic resistance genes (ARGs) that enter the environment. This study assessed the effects of inoculation with mature compost (MC) on the fates of ARGs and the bacterial community during swine manure composting. The results showed that MC prolonged the thermophilic period and promoted the decomposition of organic matter, which was due to the rapid growth and reproduction of thermophilic bacteria (Bacillus, Thermobifida, and Thermobacillus). MC significantly reduced the relative abundances of ARGs (1.02 logs) and mobile genetic elements (MGEs) (1.70 logs) after composting, especially sulfanilamide resistance genes. The total ARGs removal rate was 1.11 times higher in MC than the control. Redundancy analysis and structural equation modeling showed that horizontal gene transfer mediated by MGEs (ISCR1 and intI1) was the main direct factor related to the changes in ARGs during composting, whereas the C/N ratio and pH were the two most important indirect factors. Network analysis showed that members of Firmicutes comprising Romboutsia, Clostridisensu_stricto_1, and Terrisporobacter were the main bacterial hosts of ARGs and MGEs. MC reduced the risk of ARGs transmission by decreasing the abundances of bacterial hosts. Thus, MC is a promising strategy for reducing the proliferation risk of ARGs. | 2021 | 33858100 |