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1.
Microbiol Res ; 236: 126451, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32146294

RESUMO

Burkholderia species have different lifestyles establishing mutualist or pathogenic associations with plants and animals. Changes in the ecological behavior of these bacteria may depend on genetic variations in response to niche adaptation. Here, we studied 15 Burkholderia strains isolated from different environments with respect to genetic and phenotypic traits. By Multilocus Sequence Analysis (MLSA) these isolates fell into 6 distinct groups. MLSA clusters did not correlate with strain antibiotic sensitivity, but with the bacterial ability to produce antimicrobial compounds and control orchid necrosis. Further, the B. seminalis strain TC3.4.2R3, a mutualistic bacterium, was inoculated into orchid plants and the interaction with the host was evaluated by analyzing the plant response and the bacterial oxidative stress response in planta. TC3.4.2R3 responded to plant colonization by increasing its own growth rate and by differential gene regulation upon oxidative stress caused by the plant, while reducing the plant's membrane lipid peroxidation. The bacterial responses to oxidative stress were recapitulated by bacterial exposure to the herbicide paraquat. We suggest that the ability of Burkholderia species to successfully establish in the rhizosphere correlates with genetic variation, whereas traits associated with antibiotic resistance are more likely to be categorized as strain specific.


Assuntos
Adaptação Biológica/genética , Infecções por Burkholderia , Burkholderia , Interações entre Hospedeiro e Microrganismos , Orchidaceae/microbiologia , Aclimatação/genética , Anti-Infecciosos/farmacologia , Agentes de Controle Biológico/farmacologia , Burkholderia/genética , Burkholderia/crescimento & desenvolvimento , Burkholderia/isolamento & purificação , Burkholderia/metabolismo , Resistência Microbiana a Medicamentos/genética , Endófitos/genética , Endófitos/crescimento & desenvolvimento , Endófitos/isolamento & purificação , Endófitos/metabolismo , Genes Bacterianos , Ilhas Genômicas , Genótipo , Peroxidação de Lipídeos , Tipagem de Sequências Multilocus , Orchidaceae/fisiologia , Estresse Oxidativo/genética , Fenótipo , Filogenia , Doenças das Plantas/microbiologia , Doenças das Plantas/terapia , RNA Ribossômico 16S/genética , Simbiose , Transcriptoma
2.
Chemosphere ; 250: 126181, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32109697

RESUMO

The variation of antibiotic resistance genes (ARGs) and influential factors in pig manure composting were investigated by conducting simulated composting tests using four different supplement materials (wheat straw, corn straw, poplar sawdust and spent mushroom). The results show that the relative abundance of total ARGs increased by 0.19-1.61 logs after composting, and tetX, sulI, sulII, dfrA1 and aadA were the major contributors. The variations of ARG profiles and bacterial communities throughout the composting were clearly divided into mesophilic-thermophilic and cooling-maturation stages in all tests, while different supplement materials did not exert a noticeable influence. Network analysis demonstrated the diversity of bacterial hosts for ARGs, the existence of multiple antibiotic resistant bacteria, and the weak correlations between ARGs and physicochemical factors in the composting piles. Of note, integron intI1 and Mycobacterium (a potential pathogen) were positively correlated with eight and four ARGs, respectively, that displayed increased abundance after composting.


Assuntos
Compostagem , Resistência Microbiana a Medicamentos/genética , Agaricales , Animais , Antibacterianos , Bactérias/efeitos dos fármacos , Genes Bacterianos/efeitos dos fármacos , Integrons , Esterco/análise , Suínos , Zea mays/efeitos dos fármacos
3.
Nature ; 578(7796): 582-587, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32051588

RESUMO

Addressing the ongoing antibiotic crisis requires the discovery of compounds with novel mechanisms of action that are capable of treating drug-resistant infections1. Many antibiotics are sourced from specialized metabolites produced by bacteria, particularly those of the Actinomycetes family2. Although actinomycete extracts have traditionally been screened using activity-based platforms, this approach has become unfavourable owing to the frequent rediscovery of known compounds. Genome sequencing of actinomycetes reveals an untapped reservoir of biosynthetic gene clusters, but prioritization is required to predict which gene clusters may yield promising new chemical matter2. Here we make use of the phylogeny of biosynthetic genes along with the lack of known resistance determinants to predict divergent members of the glycopeptide family of antibiotics that are likely to possess new biological activities. Using these predictions, we uncovered two members of a new functional class of glycopeptide antibiotics-the known glycopeptide antibiotic complestatin and a newly discovered compound we call corbomycin-that have a novel mode of action. We show that by binding to peptidoglycan, complestatin and corbomycin block the action of autolysins-essential peptidoglycan hydrolases that are required for remodelling of the cell wall during growth. Corbomycin and complestatin have low levels of resistance development and are effective in reducing bacterial burden in a mouse model of skin MRSA infection.


Assuntos
Antibacterianos/farmacologia , Descoberta de Drogas , Peptidoglicano/efeitos dos fármacos , Peptidoglicano/metabolismo , Actinobacteria/química , Actinobacteria/genética , Actinobacteria/metabolismo , Animais , Antibacterianos/química , Vias Biossintéticas/genética , Parede Celular/metabolismo , Clorofenóis/química , Clorofenóis/metabolismo , Clorofenóis/farmacologia , Modelos Animais de Doenças , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Feminino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Família Multigênica , N-Acetil-Muramil-L-Alanina Amidase/antagonistas & inibidores , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Peptídeos Cíclicos/farmacologia , Filogenia , Pele/microbiologia , Infecções Estafilocócicas/microbiologia
4.
Environ Pollut ; 259: 113901, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32023788

RESUMO

Soil antibiotic resistome and the nitrogen cycle are affected by florfenicol addition to manured soils but their interactions have not been fully described. In the present study, antibiotic resistance genes (ARGs) and nitrogen cycle genes possessed by soil bacteria were characterized using real-time fluorescence quantification PCR (qPCR) and metagenomic sequencing in a short-term (30 d) soil model experiment. Florfenicol significantly changed in the abundance of genes conferring resistance to aminoglycosides, ß-lactams, tetracyclines and macrolides. And the abundance of Sphingomonadaceae, the protein metabolic and nitrogen metabolic functions, as well as NO reductase, nitrate reductase, nitrite reductase and N2O reductase can also be affected by florfenicol. In this way, ARG types of genes conferring resistance to aminoglycosides, ß-lactamases, tetracyclines, colistin, fosfomycin, phenicols and trimethoprim were closely associated with multiple nitrogen cycle genes. Actinobacteria, Chlorobi, Firmicutes, Gemmatimonadetes, Nitrospirae, Proteobacteria and Verrucomicrobia played an important role in spreading of ARGs. Moreover, soil physicochemical properties were important factors affecting the distribution of soil flora. This study provides a theoretical basis for further exploration of the transmission regularity and interference mechanism of ARGs in soil bacteria responsible for nitrogen cycle.


Assuntos
Bactérias , Resistência Microbiana a Medicamentos , Microbiota , Microbiologia do Solo , Tianfenicol/análogos & derivados , Antibacterianos/análise , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/genética , Ciclo do Nitrogênio , Solo/química , Tianfenicol/análise , Tianfenicol/farmacologia
5.
Mar Pollut Bull ; 151: 110856, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056638

RESUMO

The distribution of 14 ARGs, intI1, and 16S rDNA were analysed in 4 wastewater treatment plants (WWTPs), 2 effluent receiving areas (ERAs), and Hangzhou Bay (HZB). The results showed that each integrated WWTP (IWWTP) received higher abundance of ARGs than pharmaceutical WWTPs (PWWTPs), and IWWTPs removed ARGs more efficiently than PWWTPs. The WWTP effluents greatly contributed to the ARGs pollution in the water environments of the ERAs and HZB, and the total abundance of the ARGs displayed a distance decay pattern. In coastal sediments, more ARGs were accumulated in remote sites. The correlation analysis showed that the occurrence of ARGs was more related to 16S rDNA and intI1 in the WWTPs. Three macrolides resistance genes (ermB, mphA, and vatB) had strong correlations with 16S rDNA and intI1 in all the sample groups. Our study clearly reveals the link between land WWTPs discharge and emerging pollution of ARGs in coastal environments.


Assuntos
Baías , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Águas Residuárias , Poluição da Água , Antibacterianos , China
6.
Chemosphere ; 247: 125908, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31972491

RESUMO

Antibiotic resistance genes (ARGs) have been frequently detected in various matrices all over the world to attract wide attention due to the potential risks. Rare information is available on the pollution of ARGs in the waters of critical ecologically fragile regions such as the coastal zone at a continental scale. Therefore, this study performed field sampling during winter and summer along 18000 km coastline of China to investigate the distribution of target ARGs in coastal waters at a continental scale. The absolute abundances of ARGs in coastal waters showed drastic spatio-temporal variation with a mean value of 8.79 × 104/1.39 × 105 copies/mL in summer/winter, much lower than those in tail water from the maricultural zone or wastewater. The average absolute abundance of class 1 integron-integrase gene (intI1) in coastal waters was 9.68 × 103/4.15 × 104 copies/mL in summer/winter, still lower than that in tail water or wastewater. Quinolone resistance genes were the dominant ARGs in coastal waters to account for over 50% of total ARGs in most of sampling sites. Bacterial communities in coastal waters showed significant difference both at phylum and genus levels. Abundances of ARGs in coastal waters of this study were comparable with those in other regions previously reported. Tail water and wastewater might be the essential sources of ARGs in coastal waters. The findings of this study provided comprehensive information on the pollution status of ARGs in coastal waters at a continental scale, indicating that ARGs pollution has become a crucial stress affecting the sustainable development of coastal regions.


Assuntos
Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Genes Bacterianos , Água do Mar/microbiologia , Poluição da Água/análise , Antibacterianos , Bactérias/efeitos dos fármacos , China , Integrons , Quinolonas , Estações do Ano , Poluição da Água/estatística & dados numéricos
7.
PLoS Pathog ; 16(1): e1008211, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31971995

RESUMO

The decades-long global trend of urbanization has led to a population that spends increasing amounts of time indoors. Exposure to microbes in buildings, and specifically in dust, is thus also increasing, and has been linked to various health outcomes and to antibiotic resistance genes (ARGs). These are most efficiently screened using DNA sequencing, but this method does not determine which microbes are viable, nor does it reveal whether their ARGs can actually disseminate to other microbes. We have thus performed the first study to: 1) examine the potential for ARG dissemination in indoor dust microbial communities, and 2) validate the presence of detected mobile ARGs in viable dust bacteria. Specifically, we integrated 166 dust metagenomes from 43 different buildings. Sequences were assembled, annotated, and screened for potential integrons, transposons, plasmids, and associated ARGs. The same dust samples were further investigated using cultivation and isolate genome and plasmid sequencing. Potential ARGs were detected in dust isolate genomes, and we confirmed their placement on mobile genetic elements using long-read sequencing. We found 183 ARGs, of which 52 were potentially mobile (associated with a putative plasmid, transposon or integron). One dust isolate related to Staphylococcus equorum proved to contain a plasmid carrying an ARG that was detected metagenomically and confirmed through whole genome and plasmid sequencing. This study thus highlights the power of combining cultivation with metagenomics to assess the risk of potentially mobile ARGs for public health.


Assuntos
Poluição do Ar em Ambientes Fechados , Resistência Microbiana a Medicamentos/genética , Poeira , Genes Bacterianos , Microbiota/genética , Microbiologia Ambiental , Transferência Genética Horizontal , Genoma Bacteriano , Metagenômica
8.
J Environ Sci (China) ; 89: 277-286, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31892399

RESUMO

As a major reservoir of antibiotics, animal manure contributes a lot to the augmented environmental pressure of antibiotic resistance genes (ARGs). This might be the first study to explore the effects of different ventilation types on the control of ARGs and to identify the relationships between archaeal communities and ARGs during the composting of dairy manure. Several ARGs were quantified via Real-time qPCR and microbial communities including bacteria and archaea were analyzed by High-throughput sequencing during vacuum-type composting (VTC) and positive-pressure composting (PPC). The total detected ARGs and class I integrase gene (intI1) under VTC were significantly lower than that under PPC during each stage of the composting (p<0.001). The relative abundance of potential human pathogenic bacteria (HPB) which were identified based on sequencing information and correlation analysis decreased by 74.6% and 91.4% at the end of PPC and VTC, respectively. The composition of archaeal communities indicated that methane-producing archaea including Methanobrevibacter, Methanocorpusculum and Methanosphaera were dominant throughout the composting. Redundancy analysis suggested that Methanobrevibacter and Methanocorpusculum were positively correlated with all of the detected ARGs. Network analysis determined that the possible hosts of ARGs were different under VTC and PPC, and provided new sights about potential links between archaea and ARGs. Our results showed better performance of VTC in reducing ARGs and potential HPB and demonstrated that some archaea could also be influential hosts of ARGs, and caution the risks of archaea carrying ARGs.


Assuntos
Compostagem/métodos , Resistência Microbiana a Medicamentos/genética , Genes Arqueais , Animais , Antibacterianos , Archaea , Genes Bacterianos , Esterco , Vácuo
9.
Chemosphere ; 248: 126014, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31995737

RESUMO

Microbial fuel cell constructed wetlands (CW-MFCs) with different circuit operation conditions and hydraulic retention time (HRT) were constructed to evaluate their ability to remove and accumulate pharmaceutical and personal care products (PPCPs) (sulfadiazine (SDZ), carbamazepine (CBZ), naproxen (NPX) and ibuprofen (IBP)) during four months running process. The abundance level of corresponding sulfonamide antibiotic resistance genes (ARGs) was also investigated. The results showed that closed circuit operation of CW-MFC contributed to the decrease in mass loading of COD, NH4+-N, PPCPs, and wastewater toxicity in the effluent. Additionally, closed circuit operation with low HRT contributed to enhancing selected PPCP mass accumulation on electrodes by electro-adsorption, and thus the higher sulfonamide ARG abundance was detected in the electrodes and effluent. Moreover, the composition of bacteria was greatly influenced by the mass accumulation of PPCPs revealed by redundancy analysis results. Procrustes analysis results further demonstrated that bacterial community contributed greatly to the ARGs profiles. Therefore, ARGs with their host bacteria revealed by network analysis were partially deposited on electrode substrates, and thus ARGs were effectively accumulated on electrodes. Function analysis of the bacterial community from PICRUSt predicted metagenomes revealed that closed circuit mode enhanced the abundances of the function genes of metabolic and the multiple ARGs, suggesting that closed circuit operation exhibited positive effects on metabolic process and ARG accumulation in CW-MFC system.


Assuntos
Antibacterianos , Fontes de Energia Bioelétrica/microbiologia , Resistência Microbiana a Medicamentos/genética , Sulfonamidas , Eliminação de Resíduos Líquidos/métodos , Bactérias , Fenômenos Fisiológicos Bacterianos , Eletrodos , Genes Bacterianos , Preparações Farmacêuticas , Sulfadiazina , Sulfanilamida , Águas Residuárias/química , Áreas Alagadas
10.
PLoS One ; 15(1): e0227136, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923233

RESUMO

Antibiotics are administered to livestock in animal feeding operations (AFOs) for the control, prevention, and treatment of disease. Manure from antibiotic treated livestock contains unmetabolized antibiotics that provide selective pressure on bacteria, facilitating the expression of anti-microbial resistance (AMR). Manure application on row crops is an agronomic practice used by growers to meet crop nutrient needs; however, it can be a source of AMR to the soil and water environment. This study in central Iowa aims to directly compare AMR indicators in outlet runoff from two adjacent (221 to 229 ha) manured and non-manured catchments (manure comparison), and among three catchments (600 to 804 ha) with manure influence, no known manure application (control), and urban influences (mixed land use comparison). Monitored AMR indicators included antibiotic resistance genes (ARGs) ermB, ermF (macrolide), tetA, tetM, tetO, tetW (tetracycline), sul1, sul2 (sulfonamide), aadA2 (aminoglycoside), vgaA, and vgaB (pleuromutilin), and tylosin and tetracycline resistant enterococci bacteria. Results of the manure comparison showed significantly higher (p<0.05) tetracycline and tylosin resistant bacteria from the catchment with manure application in 2017, but no differences in 2018, possibly due to changes in antibiotic use resulting from the Veterinary Feed Directive. Moreover, the ARG analysis indicated a larger diversity of ARGs at the manure amended catchment. The mixed land use comparison showed the manure amended catchment had significantly higher (p<0.05) tetracycline resistant bacteria in 2017 and significantly higher tylosin resistant bacteria in 2017 and 2018 than the urban influenced catchment. The urban influenced catchment had significantly higher ermB concentrations in both sampling years, however the manure applied catchment runoff consisted of higher relative abundance of total ARGs. Additionally, both catchments showed higher AMR indicators compared to the control catchment. This study identifies four ARGs that might be specific to AMR as a result of agricultural sources (tetM, tetW, sul1, sul2) and optimal for use in watershed scale monitoring studies for tracking resistance in the environment.


Assuntos
Agricultura , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Água Subterrânea/microbiologia , Esterco/microbiologia , Animais , Enterococcus/genética , Iowa , Gado/microbiologia , Tetraciclina/farmacologia , Tilosina/farmacologia
11.
Chemosphere ; 246: 125736, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31896018

RESUMO

Multidrug-resistant Escherichia coli and antibiotic-resistance genes (ARGs) present a danger to public health. However, information on the dissemination potentials of antibiotic resistance among bacteria from different environments is lacking. We isolated multiple antibiotic-resistant Escherichia spp. from animal farms, hospitals, and municipal wastewater-treatment plants (MWWTPs) using culture-based methods, and carried out resistance phenotype and gene analyses. Thirty-five isolates of multiple antibiotic-resistant Escherichia spp. were further screened to detect 61 ARGs, 18 mobile genetic elements (MGEs), and gene cassettes. The isolates from livestock manure and MWWTPs showed greater diversity in plasmid profiling than hospital wastewater. Each Escherichia sp. carried 21-26 ARGs and 8-12 MGEs. In addition, 11 gene cassettes were detected in 34 Escherichia isolates, with greater diversity in livestock manure and MWWTPs than in hospital wastewater. The results indicated that the potential for ARG transfer was higher in livestock manure and MWWTPs compared with human clinical sources, possibly related to the high occurrence of both residual antibiotics and heavy metals in these environments.


Assuntos
Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Genes Bacterianos , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Escherichia , Humanos , Gado , Esterco/microbiologia , Metais Pesados , Plasmídeos , Águas Residuárias/microbiologia
12.
PLoS Comput Biol ; 16(1): e1007511, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31929521

RESUMO

Antimicrobial resistance (AMR) is an increasing threat to public health. Current methods of determining AMR rely on inefficient phenotypic approaches, and there remains incomplete understanding of AMR mechanisms for many pathogen-antimicrobial combinations. Given the rapid, ongoing increase in availability of high-density genomic data for a diverse array of bacteria, development of algorithms that could utilize genomic information to predict phenotype could both be useful clinically and assist with discovery of heretofore unrecognized AMR pathways. To facilitate understanding of the connections between DNA variation and phenotypic AMR, we developed a new bioinformatics tool, variant mapping and prediction of antibiotic resistance (VAMPr), to (1) derive gene ortholog-based sequence features for protein variants; (2) interrogate these explainable gene-level variants for their known or novel associations with AMR; and (3) build accurate models to predict AMR based on whole genome sequencing data. We curated the publicly available sequencing data for 3,393 bacterial isolates from 9 species that contained AMR phenotypes for 29 antibiotics. We detected 14,615 variant genotypes and built 93 association and prediction models. The association models confirmed known genetic antibiotic resistance mechanisms, such as blaKPC and carbapenem resistance consistent with the accurate nature of our approach. The prediction models achieved high accuracies (mean accuracy of 91.1% for all antibiotic-pathogen combinations) internally through nested cross validation and were also validated using external clinical datasets. The VAMPr variant detection method, association and prediction models will be valuable tools for AMR research for basic scientists with potential for clinical applicability.


Assuntos
Antibacterianos/farmacologia , Bactérias , Resistência Microbiana a Medicamentos/genética , Aprendizado de Máquina , Sequenciamento Completo do Genoma/métodos , Algoritmos , Bactérias/efeitos dos fármacos , Bactérias/genética , Mapeamento Cromossômico , DNA Bacteriano/análise , DNA Bacteriano/genética , Genoma Bacteriano/genética , Modelos Estatísticos , Software
13.
BMC Bioinformatics ; 21(1): 20, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941435

RESUMO

BACKGROUND: Antibiotic resistance genes (ARGs) can spread among pathogens via horizontal gene transfer, resulting in imparities in their distribution even within the same species. Therefore, a pan-genome approach to analyzing resistomes is necessary for thoroughly characterizing patterns of ARGs distribution within particular pathogen populations. Software tools are readily available for either ARGs identification or pan-genome analysis, but few exist to combine the two functions. RESULTS: We developed Pan Resistome Analysis Pipeline (PRAP) for the rapid identification of antibiotic resistance genes from various formats of whole genome sequences based on the CARD or ResFinder databases. Detailed annotations were used to analyze pan-resistome features and characterize distributions of ARGs. The contribution of different alleles to antibiotic resistance was predicted by a random forest classifier. Results of analysis were presented in browsable files along with a variety of visualization options. We demonstrated the performance of PRAP by analyzing the genomes of 26 Salmonella enterica isolates from Shanghai, China. CONCLUSIONS: PRAP was effective for identifying ARGs and visualizing pan-resistome features, therefore facilitating pan-genomic investigation of ARGs. This tool has the ability to further excavate potential relationships between antibiotic resistance genes and their phenotypic traits.


Assuntos
Resistência Microbiana a Medicamentos/genética , Software , Alelos , China , Salmonella enterica/genética , Sequenciamento Completo do Genoma
14.
Environ Pollut ; 259: 113877, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31926390

RESUMO

Long-term substantial application of fungicides in greenhouse cultivation led to residual pollution in soils and then altered soil microbial community. However, it is unclear whether residual fungicides could affect the diversity and abundance of antibiotic resistance genes (ARGs) in greenhouse soils. Here, the dissipation of fungicides and its impact on the abundance of ARGs were determined using shotgun metagenomic sequencing in the greenhouse and mountain soils under laboratory conditions. Our results showed the greenhouse soils harbored more diverse and abundant ARGs than the mountain soils. The application of carbendazim, azoxystrobin, and chlorothalonil could increase the abundance of total ARGs in the greenhouse soils, especially for those dominant ARG subtypes including sul2, sul1, aadA, tet(L), tetA(G), and tetX2. The abundant ARGs were significantly correlated with mobile genetic elements (MGEs, e.g. intI1and R485) in the greenhouse soils but no significant relationship in the mountain soils. Meanwhile, the co-occurrence patterns of ARGs and MGEs, e.g., sul2 and R485, sul1 and transposase, were further verified via the genetic arrangement of genes on the metagenome-assembled contigs in the greenhouse soils. Additionally, host tracking analysis indicated that ARGs were mainly carried by enterobacteria in the greenhouse soils but actinomyces in the mountain soils. These findings confirmed that some fungicides might serve as the co-selectors of ARGs and elevated their abundance via MGEs-mediated horizontal gene transfer in the greenhouse soils.


Assuntos
Resistência Microbiana a Medicamentos , Fungicidas Industriais , Microbiologia do Solo , Agricultura , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Fungicidas Industriais/farmacologia , Genes Bacterianos/genética
15.
Ecotoxicol Environ Saf ; 190: 110131, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31901538

RESUMO

Landfills are one of the most important reservoirs of antibiotic resistance genes (ARGs), and ARG pollution in landfills has been well investigated. However, the various factors contributing to the widespread prevalence of ARGs in landfills have rarely been explored. Here, we quantified three classes of antibiotics, six kinds of heavy metals, eight types of ARGs, and five varieties of mobile genetic elements (MGEs) in refuse samples from 10 landfills in Zhejiang Province, China. Compared with sulfonamides and macrolides, fluoroquinolones were present at much higher concentrations in all refuse samples, reaching a concentration of 1406.85 µg/kg in the Jiaxing region. The relative abundances of qnrD, qnrS, mexF, ermA, ermB, mefA, sul1, and sul2 in most landfills were >10-4 copies per 16S rRNA, suggesting the presence of highly contaminated ARGs. No significant correlations between most target antibiotics and their corresponding ARGs were found. Variation partitioning analysis indicated that MGEs could be the determining factor in the spread of ARGs in landfills. This research not only reveals high levels of ARGs and the ubiquitous presence of antibiotics in refuse, but also provides guidance for controlling the spread of ARGs in landfills.


Assuntos
Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Instalações de Eliminação de Resíduos , Antibacterianos , China , Fluoroquinolonas , Genes Bacterianos/efeitos dos fármacos , Macrolídeos , Metais Pesados/análise , Prevalência , RNA Ribossômico 16S/genética , Sulfonamidas
16.
Science ; 367(6474): 200-204, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31919223

RESUMO

Drug combinations are widely used in clinical practice to prevent the evolution of resistance. However, little is known about the effect of tolerance, a different mode of survival, on the efficacy of drug combinations for preventing the evolution of resistance. In this work, we monitored Staphylococcus aureus strains evolving in patients under treatment. We detected the rapid emergence of tolerance mutations, followed by the emergence of resistance, despite the combination treatment. Evolution experiments on the clinical strains in vitro revealed a new way by which tolerance promotes the evolution of resistance under combination treatments. Further experiments under different antibiotic classes reveal the generality of the effect. We conclude that tolerance is an important factor to consider in designing combination treatments that prevent the evolution of resistance.


Assuntos
Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Evolução Molecular , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/microbiologia , Antibacterianos/uso terapêutico , RNA Polimerases Dirigidas por DNA/genética , Daptomicina/farmacologia , Daptomicina/uso terapêutico , Quimioterapia Combinada , Humanos , Testes de Sensibilidade Microbiana , Mutação , Polimorfismo de Nucleotídeo Único , Rifampina/farmacologia , Rifampina/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Vancomicina/farmacologia , Vancomicina/uso terapêutico
17.
Chemosphere ; 241: 124843, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31605997

RESUMO

Climate changes push for water reuse as a priority to counteract water scarcity and minimize water footprint especially in agriculture, one of the highest water consuming human activities. Phytodepuration is indicated as a promising technology for water reclamation, also in the light of its economic and ecological sustainability, and the use of specific bacterial inocula for microbial assisted phytodepuration has been proposed as a further advance for its implementation. Here we provided an overview on the selection and use of plant growth promoting bacteria in Constructed Wetland (CW) systems, showing their advantages in terms of plant growth support and pollutant degradation abilities. Moreover, CWs are also proposed for the removal of emerging organic pollutants like antibiotics from urban wastewaters. We focused on this issue, still debated in the literature, revealing the necessity to deepen the knowledge on the antibiotic resistance spread into the environment in relation to treated wastewater release and reuse. In addition, given the presence in the plant system of microhabitats (e.g. rhizosphere) that are hot spot for Horizontal Gene Transfer, we highlighted the importance of gene exchange to understand if these events can promote the diffusion of antibiotic resistance genes and antibiotic resistant bacteria, possibly entering in the food production chain when treated wastewater is used for irrigation. Ideally, this new knowledge will lead to improve the design of phytodepuration systems to maximize the quality and safety of the treated effluents in compliance with the 'One Health' concept.


Assuntos
Bactérias/metabolismo , Biodegradação Ambiental , Purificação da Água/métodos , Áreas Alagadas , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Humanos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Águas Residuárias/química
18.
Food Chem Toxicol ; 135: 110934, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31682931

RESUMO

The novel commensal strain of Bacteroides fragilis HCK-B3 isolated from a healthy Chinese donor was discovered beneficial effects of attenuating lipopolysaccharides-induced inflammation. In order to contribute to the development of natural next-generation probiotic strains, the safety assessment was carried out with in vitro investigations of its morphology, potential virulence genes and antimicrobial resistance, and an in vivo acute toxicity study based on both healthy and immunosuppressed mice by cyclophosphamide injection. Consequently, the potential virulence genes in the genome of B. fragilis HCK-B3 have yet been identified as toxicity-associated. The absence of plasmids prevents the possibility of transferring antibiotic resistance features to other intestinal commensals. No intracorporal pathogenic properties were observed according to the body weight, hematological and liver parameters, cytokine secretions and tissue integrity. In addition, B. fragilis HCK-B3 performed alleviations on part of the side effects caused by the cyclophosphamide treatment. Thus, the novel strain of B. fragilis HCK-B3 was confirmed to be non-toxigenic and did not display adverse effects in both healthy and immune-deficient mice at a routinely applicable dose.


Assuntos
Bacteroides fragilis/patogenicidade , Probióticos/toxicidade , Animais , Antibacterianos/farmacologia , Bacteroides fragilis/efeitos dos fármacos , Bacteroides fragilis/genética , Citocinas/metabolismo , Resistência Microbiana a Medicamentos/genética , Resistência Microbiana a Medicamentos/fisiologia , Ilhas Genômicas , Masculino , Camundongos , Anotação de Sequência Molecular , Projetos Piloto , Medição de Risco
19.
Environ Pollut ; 256: 113463, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31677875

RESUMO

Growing evidence suggests that metallic oxide nanoparticles can pose a severe risk to the health of invertebrates. Previous attention has been mostly paid to the effects of metallic oxide nanoparticles on the survival, growth and physiology of animals. In comparison, the effects on gut microbiota and incidence of antibiotic resistance genes (ARGs) in soil fauna remain poorly understood. We conducted a microcosm study to explore the responses of the non-target soil invertebrate Enchytraeus crypticus gut microbiota and resistomes to copper oxide nanoparticles (CuO NPs) and copper nitrate by using bacterial 16S rRNA gene amplicons sequencing and high throughput quantitative PCR. The results showed that exposure to Cu2+ resulted in higher bioaccumulation (P < 0.05) and lower body weight and reproduction (P < 0.05) of Enchytraeus crypticus than exposure to CuO NPs. Nevertheless, exposure to CuO NPs for 21 days markedly increased the alpha-diversity of the gut microbiota of Enchytraeus crypticus (P < 0.05) and shifted the gut microbial communities, with a significant decline in the relative abundance of the phylum Planctomycetes (from 37.26% to 19.80%, P < 0.05) and a significant elevation in the relative abundance of the phyla Bacteroidetes, Firmicutes and Acidobacteria (P < 0.05). The number of detected ARGs in the Enchytraeus crypticus gut significantly decreased from 45 in the Control treatment to 16 in the Cu(NO3)2 treatment and 20 in the CuO NPs treatment. The abundance of ARGs in the Enchytraeus crypticus gut were also significantly decreased to 38.48% when exposure to Cu(NO3)2 and 44.90% when exposure to CuO NPs (P < 0.05) compared with the controls. These results extend our understanding of the effects of metallic oxide nanoparticles on the gut microbiota and resistome of soil invertebrates.


Assuntos
Cobre/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Oligoquetos/fisiologia , Poluentes do Solo/toxicidade , Animais , Bactérias/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Microbioma Gastrointestinal/fisiologia , Microbiota/efeitos dos fármacos , Nitratos , Oligoquetos/efeitos dos fármacos , Oligoquetos/microbiologia , RNA Ribossômico 16S , Solo , Poluentes do Solo/análise
20.
Chemosphere ; 245: 125484, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31864053

RESUMO

Wastewater from high-speed railway trains represents a mobile reservoir of microorganisms with antibiotic resistance. It harbors abundant and diverse antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). This study investigated the removal of ARB and ARGs in a pilot-scale reactor, which consisted of an anaerobic/anoxic/oxic process, anaerobic/anoxic/aerobic process, and ozone-based disinfection to treat 1 m3/day wastewater from an electric multiple unit high-speed train. Further, the high prevalence of two mobile genetic elements (intI1 and Tn916/615) and five ARGs (tetA, tetG, qnrA, qnrS, blaNDM-1, and ermF) was investigated using quantitative PCR. Significant positive correlations between ARGs (tetA, blaNDM-1, and qnrA) and intI1 were identified (R2 of 0.94, 0.85, and 0.70, respectively, P < 0.01). Biological treatment could significantly reduce Tn916/1545 (2.57 logs reduction) and Enterococci (2.56 logs reduction of colony forming unit (CFU)/mL), but the qnrS abundance increased (1.19 logs increase). Ozonation disinfection could further significantly decrease ARGs and Enterococci in wastewater, with a reduction of 1.67-2.49 logs and 3.16 logs CFU/mL, respectively. Moreover, food-related bacteria families which may contain opportunistic or parasitic pathogens (e.g., Moraxellaceae, Carnobacteriaceae, and Ruminococcaceae) were detected frequently. Enterococci filtered in this study shows multi-antibiotic resistance. Our study highlights the significance to mitigate antibiotic resistance from wastewater generated from high-speed railway trains, as a mobile source.


Assuntos
Resistência Microbiana a Medicamentos/genética , Ferrovias , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Desinfecção , Genes Bacterianos/efeitos dos fármacos , Ozônio
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