RESUMO
Plastic pollution represents a critical threat to soil ecosystems and even humans, as plastics can serve as a habitat for breeding and refuging pathogenic microorganisms against stresses. However, evaluating the health risk of plastispheres is difficult due to the lack of risk factors and quantification model. Here, DNA sequencing, single-cell Raman-D2O labeling, and transformation assay were used to quantify key risk factors of plastisphere, including pathogen abundance, phenotypic resistance to various stresses (antibiotic and pesticide), and ability to acquire antibiotic resistance genes. A Bayesian network model was newly introduced to integrate these three factors and infer their causal relationships. Using this model, the risk of pathogen in the plastisphere is found to be nearly 3 magnitudes higher than that in free-living state. Furthermore, this model exhibits robustness for risk prediction, even in the absence of one factor. Our framework offers a novel and practical approach to assessing the health risk of plastispheres, contributing to the management of plastic-related threats to human health.
Assuntos
Teorema de Bayes , Bactérias/genética , Bactérias/isolamento & purificação , Fenótipo , Microbiologia do Solo , Humanos , Antibacterianos/farmacologiaRESUMO
Global patterns in soil microbiomes are driven by non-linear environmental thresholds. Fertilization is known to shape the soil microbiome of terrestrial ecosystems worldwide. Yet, whether fertilization influences global thresholds in soil microbiomes remains virtually unknown. Here, utilizing optimized machine learning models with Shapley additive explanations on a dataset of 10,907 soil samples from 24 countries, we discovered that the microbial community response to fertilization is highly dependent on environmental contexts. Furthermore, the interactions among nitrogen (N) addition, pH, and mean annual temperature contribute to non-linear patterns in soil bacterial diversity. Specifically, we observed positive responses within a soil pH range of 5.2-6.6, with the influence of higher temperature (>15°C) on bacterial diversity being positive within this pH range but reversed in more acidic or alkaline soils. Additionally, we revealed the threshold effect of soil organic carbon and total nitrogen, demonstrating how temperature and N addition amount interacted with microbial communities within specific edaphic concentration ranges. Our findings underscore how complex environmental interactions control soil bacterial diversity under fertilization.
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Bactérias , Fertilizantes , Microbiota , Nitrogênio , Microbiologia do Solo , Solo , Temperatura , Nitrogênio/análise , Nitrogênio/metabolismo , Fertilizantes/análise , Concentração de Íons de Hidrogênio , Solo/química , Carbono/análise , Carbono/metabolismo , Aprendizado de Máquina , BiodiversidadeRESUMO
Soil bacteria are diverse and form complicated ecological networks through various microbial interactions, which play important roles in soil multi-functionality. However, the seasonal effects on the bacterial network, especially the relationship between bacterial network topological features and soil resistomes remains underexplored, which impedes our ability to unveil the mechanisms of the temporal-dynamics of antibiotic resistance genes (ARGs). Here, a field investigation was conducted across four seasons at the watershed scale. We observed significant seasonal variation in bacterial networks, with lower complexity and stability in autumn, and a wider bacterial community niche in summer. Similar to bacterial communities, the co-occurrence networks among ARGs also shift with seasonal change, particularly with respect to the topological features of the node degree, which on average was higher in summer than in the other seasons. Furthermore, the nodes with higher betweenness, stress, degree, and closeness centrality in the bacterial network showed strong relationships with the 10 major classes of ARGs. These findings highlighted the changes in the topological properties of bacterial networks that could further alter antibiotic resistance in soil. Together, our results reveal the temporal dynamics of bacterial ecological networks at the watershed scale, and provide new insights into antibiotic resistance management under environmental changes.
Assuntos
Genes Bacterianos , Solo , Microbiologia do Solo , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Antibacterianos/farmacologiaRESUMO
BACKGROUND: Previous studies have shown that IL-25 levels are increased in patients with asthma with fixed airflow limitation (FAL). However, the mechanism by which IL-25 contributes to airway remodeling and FAL remains unclear. Here, we hypothesized that IL-25 facilitates pro-fibrotic phenotypic changes in bronchial epithelial cells (BECs) and circulating fibrocytes (CFs), orchestrates pathological crosstalk from BECs to CFs, and thereby contributes to airway remodeling and FAL. METHODS: Fibrocytes from asthmatic patients with FAL and chronic asthma murine models were detected using flow cytometry, multiplex staining and multispectral imaging analysis. The effect of IL-25 on BECs and CFs and on the crosstalk between BECs and CFs was determined using cell culture and co-culture systems. RESULTS: We found that asthmatic patients with FAL had higher numbers of IL-25 receptor (i.e., IL-17RB)+-CFs, which were negatively correlated with forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC). The number of airway IL-17RB+-fibrocytes was significantly increased in ovalbumin (OVA)- and IL-25-induced asthmatic mice versus the control subjects. BECs stimulated with IL-25 exhibited an epithelial-mesenchymal transition (EMT)-like phenotypic changes. CFs stimulated with IL-25 produced high levels of extracellular matrix (ECM) proteins and connective tissue growth factors (CTGF). These profibrotic effects of IL-25 were partially blocked by the PI3K-AKT inhibitor LY294002. In the cell co-culture system, OVA-challenged BECs facilitated the migration and expression of ECM proteins and CTGF in CFs, which were markedly blocked using an anti-IL-17RB antibody. CONCLUSION: These results suggest that IL-25 may serve as a potential therapeutic target for asthmatic patients with FAL.
Assuntos
Remodelação das Vias Aéreas , Asma , Animais , Camundongos , Fosfatidilinositol 3-Quinases , Células Epiteliais , Inibidores da Angiogênese , Proteínas da Matriz ExtracelularRESUMO
The widespread occurrence of tire tread particles (TPs) has aroused increasing concerns over their impacts. However, how they affect the soil fauna remains poorly understood. Here, based on systematically assessing the toxicity of TPs on soil model speciesEnchytraeus crypticusat environmentally relevant concentrations through both soil and food exposure routes, we reported that TPs affected gut microbiota, intestinal histopathology, and metabolites of the worms both through particulate- and leachate-induced effects, while TP leachates exerted stronger effects. The dominant role of TP leachates in TP toxicity was further explained by the findings that worms did not ingest TPs with a particle size of over 150 µm and actively avoided consuming TP particles. Moreover, by comparing the effects of different brands of TPs as well as new and aged TPs, we demonstrated that it was mainly TP leachates that resulted in the ubiquity of the disturbance in the worm's gut microbiota among different brands of TPs. Notably, the large variations in leachate compositions among different brands of TPs provided us a unique opportunity to identify the determinants of TP toxicity. These results provide novel insights into the toxicity of TPs to soil fauna and a reference for toxicity reduction of tires.
Assuntos
Microbioma Gastrointestinal , Poeira , Tamanho da Partícula , SoloRESUMO
Although bottom-up attention can improve visual performance with and without awareness to the exogenous cue, whether they are governed by a common neural computation remains unclear. Using a modified Posner paradigm with backward masking, we found that the cueing effect displayed a monotonic gradient profile (Gaussian-like), both with and without awareness, whose scope, however, was significantly wider with than without awareness. This awareness-dependent scope offered us a unique opportunity to change the relative size of the attention field to the stimulus, differentially modulating the gain of attentional selection, as proposed by the normalization model of attention. Therefore, for each human subject (male and female), the stimulus size was manipulated as their respective mean attention fields with and without awareness while stimulus contrast was varied in a spatial cueing task. By measuring the gain pattern of contrast-response functions on the spatial cueing effect derived by visible or invisible cues, we observed changes in the cueing effect consonant with changes in contrast gain for visible cues and response gain for invisible cues. Importantly, a complementary analysis confirmed that subjects' awareness-dependent attention fields can be simulated by using the normalization model of attention. Together, our findings indicate an awareness-dependent normalization framework of visual bottom-up attention, placing a necessary constraint, namely, awareness, on our understanding of the neural computations underlying visual attention.SIGNIFICANCE STATEMENT Bottom-up attention is known to improve visual performance with and without awareness. We discovered that manipulating subjects' awareness can modulate their attention fields of visual bottom-up attention, which offers a unique opportunity to regulate its normalization processes. On the one hand, by measuring the gain pattern of contrast-response functions on the spatial cueing effect derived by visible or invisible cues, we observed changes in the cueing effect consonant with changes in contrast gain for visible cues and response gain for invisible cues. On the other hand, by using the normalization model of attention, subjects' awareness-dependent attention fields can be simulated successfully. Our study supports important predictions of the normalization model of visual bottom-up attention and further reveals its dependence on awareness.
Assuntos
Atenção/fisiologia , Conscientização/fisiologia , Modelos Neurológicos , Percepção Visual/fisiologia , Adulto , Sinais (Psicologia) , Feminino , Humanos , MasculinoRESUMO
Despite the importance of soil bacterial and fungal communities for ecosystem services and human welfare, how their ecological networks respond to climatic aridity have yet been evaluated. Here, we collected soil samples from 47 sites across 2500 km in coastal and inland areas of eastern Australia with contrasting status of aridity. We found that the diversity of both bacteria and fungi significantly differed between inland and coastal soils. Despite the significant differences in soil nutrient availability and stoichiometry between the inland and coastal regions, aridity was the most important predictor of bacterial and fungal community compositions. Aridity has altered the potential microbial migration rates and further impacted the microbial assembly processes by increasing the importance of stochasticity in bacterial and fungal communities. More importantly, ecological network analysis indicated that aridity enhanced the complexity and stability of the bacterial network but reduced that of the fungal network, possibly due to the contrasting impacts of aridity on the community-level habitat niche breadth and overlaps. Our work paves the way towards a more comprehensive understanding of how climate changes will alter soil microbial communities, which is integral to predicting their long-term consequences for ecosystem sustainability and resilience to future disturbances.
Assuntos
Microbiota , Solo , Humanos , Microbiologia do Solo , Ecossistema , Fungos/genética , Bactérias/genéticaRESUMO
Plants form complex interaction networks with diverse microbiomes in the environment, and the intricate interplay between plants and their associated microbiomes can greatly influence ecosystem processes and functions. The phyllosphere, the aerial part of the plant, provides a unique habitat for diverse microbes, and in return the phyllosphere microbiome greatly affects plant performance. As an open system, the phyllosphere is subjected to environmental perturbations, including global change, which will impact the crosstalk between plants and their microbiomes. In this review, we aim to provide a synthesis of current knowledge of the complex interactions between plants and the phyllosphere microbiome under global changes and to identify future priority areas of research on this topic.
Assuntos
Microbiota , PlantasRESUMO
Multitrophic communities inhabit in soil faunal gut, including bacteria, fungi, and protists, which have been considered a hidden reservoir for antibiotic resistance genes (ARGs). However, there is a dearth of research focusing on the relationships between ARGs and multitrophic communities in the gut of soil faunas. Here, we studied the contribution of multitrophic communities to variations of ARGs in the soil woodlouse gut. The results revealed diverse and abundant ARGs in the woodlouse gut. Network analysis further exhibited strong connections between key ecological module members and ARGs, suggesting that multitrophic communities in the keystone ecological cluster may play a pivotal role in the variation of ARGs in the woodlouse gut. Moreover, long-term application of sewage sludge significantly altered the woodlice gut resistome and interkingdom communities. The variation portioning analysis indicated that the fungal community has a greater contribution to variations of ARGs than bacterial and protistan communities in the woodlice gut after long-term application of sewage sludge. Together, our results showed that changes in gut microbiota associated with agricultural practices (e.g., sewage sludge application) can largely alter the gut interkingdom network in ecologically relevant soil animals, with implications for antibiotic resistance, which advances our understanding of the microecological drivers of ARGs in terrestrial ecosystem.
Assuntos
Isópodes , Microbiota , Animais , Solo , Esgotos/microbiologia , Antibacterianos/farmacologia , Isópodes/genética , Genes Bacterianos , Bactérias/genética , Microbiologia do SoloRESUMO
Massive microplastics are deposited in the coastal zone. Tire particles (TPs) are an important microplastic source, but little is known about how TPs affect the microbial community composition and function in coastal sediments and the role leachable additives play in TP toxicity. Here, a microcosm experiment was performed using coastal sediments amended with different doses of TPs and with their leachable additives to investigate their effects on the sediment microbial community composition and function. Environmentally relevant concentrations of TPs can change the microbial community structure, decrease community diversity, and inhibit nutrient cycling processes, including carbon fixation and degradation, nitrification, denitrification, and sulfur cycling in sediments. Notably, the raw TP and leachate treatments showed consistent effects. A variety of additives were found in the pore water of sediment, and they could explain over 90% of the variations of the community structure. Further modeling revealed that leachable additives not only directly influenced community function but also indirectly affected community diversity and function by shifting the community structure. In addition, rare taxa could be crucial mediators of ecological functions of sediment microbial community. Combined, this study provides novel insights into the role of TPs' leachable additives in affecting sediment microbial community and function.
Assuntos
Sedimentos Geológicos , Microbiota , Sedimentos Geológicos/química , Microplásticos , Nitrificação , Plásticos/farmacologiaRESUMO
Total solid content (TS) is an important factor for biogas production during anaerobic digestion. In this study, we explored the influence of different TS (5% wet, 15% semi-solid and 25% solid state) on the relative cumulative methane production (RCMP) during anaerobic co-digestion of chicken manure with corn straw. Results showed that total ammonium nitrogen and free ammonia nitrogen concentration increased with the increase of TS. Ammonium nitrogen in treatments at 15% TS was 2.25-2.76 times as high as that at 5% TS, which was below 3 times. The highest chemical oxygen demand removal and RCMP were obtained in the treatment of 15% TS with a ratio of 2:1 chicken manure: corn straw (based on TS). The RCMP in the treatments of 15% TS were 3.63-4.59 times higher than that of 5% TS based on the volume of substrates. The abundance of Caldicoprobacter improving the degradation of corn straw was significantly positively correlated with the RCMP, and the average abundance of Caldicoprobacter at 15% TS was 8.33 and 7.02 times higher than that at 5% and 25% TS, respectively. Structural equation models analysis suggested that TS significantly impacted the RCMP by indirectly impacting free ammonia nitrogen and microbial abundance. These findings indicated semi-solid state (15% TS) decreased ammonia nitrogen releasing and improved the abundance of Caldicoprobacter, and increased RCMP during anaerobic co-digestion of chicken manure with corn straw.
Assuntos
Compostos de Amônio , Esterco , Amônia/análise , Anaerobiose , Animais , Biocombustíveis/análise , Reatores Biológicos , Galinhas/metabolismo , Digestão , Esterco/análise , Metano/análise , Nitrogênio/análise , Zea mays/metabolismoRESUMO
Termites are pivotal ecosystem engineers in tropical and subtropical habitats, where they construct massive nests ('mounds') that substantially modify soil properties and promote nutrient cycling. Yet, little is known about the roles of termite nesting activity in regulating the spread of antimicrobial resistance (AMR), one of the major Global Health challenges. Here, we conducted a large-scale (> 1500 km) investigation in northern Australia and found distinct resistome profiles in termite mounds and bulk soils. By profiling a wide spectrum of ARGs, we found that the abundance and diversity of antibiotic resistance genes (ARGs) were significantly lower in termite mounds than in bulk soils (P < 0.001). The proportion of efflux pump ARGs was significantly lower in termite mound resistome than in bulk soil resistome (P < 0.001). The differences in resistome profiles between termite mounds and bulk soils may result from the changes in microbial interactions owing to the substantial increase in pH and nutrient availability induced by termite nesting activities. These findings advance our understanding of the profile of ARGs in termite mounds, which is a crucial step to evaluate the roles of soil faunal activity in regulating soil resistome under global environmental change.
Assuntos
Isópteros , Animais , Austrália , Ecossistema , Isópteros/genética , Solo , Microbiologia do SoloRESUMO
Understanding the current and future distributions of plant pathogens is critical to predict the plant performance and related economic benefits in the changing environment. Yet, little is known about the roles of environmental drivers in shaping the profiles of fungal plant pathogens in phyllosphere, an important habitat of microbiomes on Earth. Here, using a large-scale investigation of Eucalyptus phyllospheric microbiomes in Australia and the multiple linear regression model, we show that precipitation is the most important predictor of fungal taxonomic diversity and abundance. The abundance of fungal plant pathogens in phyllosphere exhibited a positive linear relationship with precipitation. With this empirical dataset, we constructed current and future atlases of phyllosphere plant pathogens to estimate their spatial distributions under different climate change scenarios. Our atlases indicate that the abundance of fungal plant pathogens would increase especially in the coastal regions with up to 100-fold increase compared with the current abundance. These findings advance our understanding of the distributions of fungal plant pathogens in phyllospheric microbiomes under the climate change, which can improve our ability to predict and mitigate their impacts on plant productivity and economic losses.
Assuntos
Eucalyptus , Microbiota , Mudança Climática , Fungos/genética , PlantasRESUMO
Crop plants carry an enormous diversity of microbiota that provide massive benefits to hosts. Protists, as the main microbial consumers and a pivotal driver of biogeochemical cycling processes, remain largely understudied in the plant microbiome. Here, we characterized the diversity and composition of protists in sorghum leaf phyllosphere, and rhizosphere and bulk soils, collected from an 8-year field experiment with multiple fertilization regimes. Phyllosphere was an important habitat for protists, dominated by Rhizaria, Alveolata and Amoebozoa. Rhizosphere and bulk soils had a significantly higher diversity of protists than the phyllosphere, and the protistan community structure significantly differed among the three plant-soil compartments. Fertilization significantly altered specific functional groups of protistan consumers and parasites. Variation partitioning models revealed that soil properties, bacteria and fungi predicted a significant proportion of the variation in the protistan communities. Changes in protists may in turn significantly alter the compositions of bacterial and fungal communities from the top-down control in food webs. Altogether, we provide novel evidence that fertilization significantly affects the functional groups of protistan consumers and parasites in crop-associated microbiomes, which have implications for the potential changes in their ecological functions under intensive agricultural managements.
Assuntos
Microbiota , Parasitos , Animais , Fertilização , Rizosfera , Solo , Microbiologia do SoloRESUMO
Termites are ubiquitous insects in tropical and subtropical habitats, and some of them construct massive nests ('mounds'), which substantially promote substrate heterogeneity by altering soil properties. Yet, the role of termite nesting process in regulating the distribution and diversity of soil microbial communities remains poorly understood, which introduces uncertainty in predictions of ecosystem functions of termite mounds in a changing environment. Here, by using amplicon sequencing, we conducted a survey of 134 termite mounds across >1500 km in northern Australia and found that termite mounds significantly differed from bulk soils in the microbial diversity and community compositions. Compared with bulk soils, termite nesting process decreased the microbial diversity and the relative abundance of rare taxa. Rare taxa had a narrower habitat niche breadth than dominant taxa and might be easier to be filtered by the potential intensive microbial competition during the nesting processes. We further demonstrated that the shift in pH induced by termite nesting process was a major driver shaping the microbial community profiles in termite mounds. Together, our work provides novel evidence that termite nesting is an important process in regulating soil microbial diversity, which advances our understanding of the functioning of termite mounds.
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Isópteros , Microbiota , Animais , Insetos , Microbiota/genética , Solo , Microbiologia do SoloRESUMO
Applying organic fertilizers has been well documented to facilitate the dissemination of antibiotic resistance genes (ARGs) in soil ecosystems. However, the role of soil fauna in this process has been seldom addressed, which hampers our ability to predict the fate of and to manage the spread of ARGs. Here, using high-throughput quantitative polymerase chain reaction (HT-qPCR), we examined the effect of long-term (5-, 8-, and 10-year) fertilization treatments (control, inorganic fertilizers, and mixed fertilizers) on the transfer of ARGs between soil, nematodes, and earthworms. We found distinct fates for ARGs in the nematodes and earthworms, with the former having higher enriched levels of ARGs than the latter. Fertilization impacted the number and abundance of ARGs in soil, and fertilization duration altered the composition of ARGs. Shared ARGs among soil, nematodes, and earthworm guts supported by a fast expectation-maximization microbial source tracking analysis demonstrated the trophic transfer potential of ARGs through this short soil food chain. The transfer of ARGs was reduced by fertilization duration, which was mainly ascribed to the reduction of ARGs in the earthworm gut microbiota. This study identified the transfer of ARGs in the soil-nematode-earthworm food chain as a potential mechanism for a wider dissemination of ARGs in the soil ecosystem.
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Microbioma Gastrointestinal , Solo , Animais , Antibacterianos , Resistência Microbiana a Medicamentos/genética , Fertilização , Genes Bacterianos , Esterco , Microbiologia do SoloRESUMO
Growing evidence suggests that livestock manure used as organic fertilizer in agriculture may lead to the potential propagation of antibiotic resistance genes (ARGs) from "farm to fork." However, little is known about the impacts of manure fertilization on the incidence of ARGs in the plant-associated microbiomes (including rhizosphere, endosphere, and phyllosphere), which hampers our ability to assess the dissemination of antibiotic resistance in the soil-plant system. Here, we constructed a pot experiment to explore the effects of poultry and cattle manure applications on the shifts in the resistome in the plant microbiome of harvested cherry radish. A total of 144 ARGs conferring resistance to eight major classes of antibiotics were detected among all the samples. Rhizosphere and phyllosphere microbiomes harbored significantly higher diversity and abundance of ARGs than did root endophytic microbiomes of cherry radish. Manure application significantly increased the abundance of ARGs in the rhizosphere and phyllosphere but not in the endophytes of the root, which is the edible part of cherry radish. Soil and plant microbiomes changed dramatically after manure applications and clustered separately according to different sample types and treatments. Structural equation modeling revealed that bacterial abundance was the most important factor modulating the distribution patterns of soil and plant resistomes after accounting for multiple drivers. Taken together, we provide evidence that enrichment of the resistome in the rhizosphere and phyllosphere of cherry radish is more obvious than with the endosphere after manure application, suggesting that manure amendment might not enhance the dissemination of ARGs into the root of vegetables in the pot experiment.IMPORTANCE Our study provides important evidence that manure application increased the occurrence of ARGs in the rhizosphere and phyllosphere of cherry radish, compared with that in the endophytic bacterial microbiota of root, which is the edible part of cherry radish. Our findings suggest that although manure amendment is a significant route of ARGs entering agricultural soils, these manure-derived ARGs may be at low risk of migrating into the endophytes of root vegetables.
Assuntos
Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Endófitos/genética , Genes Bacterianos , Esterco , Raphanus/microbiologia , Animais , Antibacterianos/farmacologia , Bovinos , Microbiota/genética , Raízes de Plantas/microbiologia , Aves DomésticasRESUMO
Protists, an integral component of soil microbiome, are one of the main predators of bacteria. Bacteria can produce toxic secondary metabolites, e.g., antibiotics to fight stress under the predation pressure of protists; however, impacts of antibiotics on the profile of protists in soils remain unclear. Here, we constructed a microcosm incubation to investigate the effects of two common antibiotics, oxytetracycline and ciprofloxacin, on the protistan and bacterial communities in an arable soil. Rhizaria were the most abundant protist supergroup, followed by Amoebozoa, Stramenopiles, and Aveolata. Among trophic functional groups, consumers were predominant within the protistan community. The protistan alpha-diversity was not significantly changed, while the bacterial alpha-diversity was decreased under the pressure of antibiotics. Nevertheless, the antibiotic exposure considerably reduced the relative abundance of protistan lineages in Rhizaria and Amoebozoa, which were the dominant supergroups of protistan consumers, while increased the relative abundance of other consumer and phototrophic protists. Altogether, we provide novel experimental evidence that the bacterivorous consumers, an important functional group of protists, were more sensitive to antibiotics than other functional groups. Our findings have potential implications for the induced alterations of protistan community and their ecological functions under the scenarios of projected increasing global antibiotic usage.
Assuntos
Oxitetraciclina , Solo , Biodiversidade , Ciprofloxacina , EucariotosRESUMO
The increasing and simultaneous pollution of plastic debris and antibiotic resistance in aquatic environments makes plastisphere a great health concern. However, the development process of antibiotic resistome in the plastisphere is largely unknown, impeding risk assessment associated with plastics. Here, we profiled the temporal dynamics of antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and microbial composition in the plastisphere from initial microbial colonization to biofilm formation in urban water. A total of 82 ARGs, 12 MGEs, and 63 bacterial pathogens were detected in the plastisphere and categorized as the pioneering, intermediate, and persistent ones. The high number of five MGEs and six ARGs persistently detected in the whole microbial colonization process was regarded as a major concern because of their potential role in disseminating antibiotic resistance. In addition to genomic analysis, D2O-labeled single-cell Raman spectroscopy was employed to interrogate the ecophysiology of plastisphere in a culture-independent way and demonstrated that the plastisphere was inherently more tolerant to antibiotics than bacterioplankton. Finally, by combining persistent MGEs, intensified colonization of pathogenic bacteria, increased tolerance to antibiotic, and potential trophic transfer into a holistic risk analysis, the plastisphere was indicated to constitute a hot spot to acquire and spread antibiotic resistance and impose a long-term risk to ecosystems and human health. These findings provide important insights into the antibiotic resistome and ecological risk of the plastisphere and highlight the necessity for comprehensive surveillance of plastisphere.
Assuntos
Antibacterianos , Genes Bacterianos , Antibacterianos/farmacologia , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Ecossistema , HumanosRESUMO
Tread particles (TPs) from vehicle tires are widely distributed in soil ecosystems; therefore, there is an urgent need to evaluate their effects on soil biota. In the present study, the soil worm Enchytraeus crypticus was incubated for 21 days in soil microcosms containing increasing concentrations of TPs (0, 0.0048%, 0.024%, 0.12%, 0.6%, and 3% of dry soil weight). High concentrations of zinc (Zn, 9407.4 mg kg-1) and polycyclic aromatic hydrocarbons (PAHs, 46.8 mg kg-1) were detected in the TPs, which resulted in their increased concentrations in soils amended with TPs. We demonstrated that TPs had an adverse effect on the survival (decreased by more than 25%) and reproduction (decreased by more than 50%) of the soil worms. Moreover, TP exposure disturbed the microbiota of the worm guts and surrounding soil. In addition, a covariation between bacterial and fungal communities was observed in the worm guts after exposure to TPs. Further analysis showed that TP exposure caused an enrichment of microbial genera associated with opportunistic pathogenesis in the worm guts. The combined results from this study indicate that TPs might threaten the terrestrial ecosystem by affecting soil fauna and their gut microbiota.