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1.
Nat Commun ; 12(1): 27, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397904

RESUMO

Bacteriophages (phages), or bacterial viruses, are very diverse and highly abundant worldwide, including as a part of the human microbiomes. Although a few metagenomic studies have focused on oral phages, they relied on short-read sequencing. Here, we conduct a long-read metagenomic study of human saliva using PromethION. Our analyses, which integrate both PromethION and HiSeq data of >30 Gb per sample with low human DNA contamination, identify hundreds of viral contigs; 0-43.8% and 12.5-56.3% of the confidently predicted phages and prophages, respectively, do not cluster with those reported previously. Our analyses demonstrate enhanced scaffolding, and the ability to place a prophage in its host genomic context and enable its taxonomic classification. Our analyses also identify a Streptococcus phage/prophage group and nine jumbo phages/prophages. 86% of the phage/prophage group and 67% of the jumbo phages/prophages contain remote homologs of antimicrobial resistance genes. Pan-genome analysis of the phages/prophages reveals remarkable diversity, identifying 0.3% and 86.4% of the genes as core and singletons, respectively. Furthermore, our study suggests that oral phages present in human saliva are under selective pressure to escape CRISPR immunity. Our study demonstrates the power of long-read metagenomics utilizing PromethION in uncovering bacteriophages and their interaction with host bacteria.


Assuntos
Bactérias/virologia , Bacteriófagos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-Patógeno/genética , Metagenômica , Boca/microbiologia , Boca/virologia , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Contaminação por DNA , DNA Viral/genética , Resistência Microbiana a Medicamentos/genética , Genes Virais , Genoma Bacteriano , Humanos , Integrases/genética , Metagenoma , Prófagos/genética , Proteômica , Streptococcus/virologia
2.
Ecotoxicol Environ Saf ; 208: 111724, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396055

RESUMO

In recent years, in order to promote animal growth and reduce the risk of disease, a variety of antibiotics are frequently added to the animal feed of livestock and poultry. However, these antibiotics can not be fully digested by animals and most of them are excreted with feces, consequently causing the enrichment of antibiotic resistance genes (ARGs) and huge environmental risks. Nowadays, composting is a better option to solve these problems. Accordingly, this study explored the effects of co-composting swine manure with different inoculants dominated by Phanerochaete chrysosporium (p), Aspergillus niger (a), and Bacillus licheniformis (b) on the simultaneous removal of multiple antibiotics and resistance genes and evolution of the bacterial community. The results showed that the highest removal extent of tetracycline and oxytetracycline occurred in pile D (p:b:a=1:5:5, biomass) reaching 89.2% and 87.8%, respectively, while the highest removal extent of doxycycline and enrofloxacin occurred in pile A (p:b:a=1:0:0, biomass) reaching 98.6% and 89%, respectively. Compared with the levels in pile B (control check), in pile D, ARGs, except those for sulfonamides, decreased by 1.059 × 10-3-6.68 × 10-2 gene copies/16S rRNA copies. Inoculation with p alone effectively reduced intI1 and intI2. Canonical correspondence analysis (CCA) that microbial community structure evolution had a greater influence on ARGs than environmental factors. In summary, this study provided a feasible way to efficiently remove the antibiotics and antibiotic resistance genes in pig manure.


Assuntos
Antibacterianos/análise , Resistência Microbiana a Medicamentos/genética , Esterco/microbiologia , Ração Animal/análise , Animais , Antibacterianos/metabolismo , Bactérias/efeitos dos fármacos , Compostagem/métodos , Genes Bacterianos , Gado , Microbiota/efeitos dos fármacos , Oxitetraciclina/farmacologia , RNA Ribossômico 16S , Suínos , Tetraciclina/farmacologia
3.
Chemosphere ; 265: 129100, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33310316

RESUMO

Behavior of veterinary antibiotics, the corresponding resistant genes in soil layer of constructed wetlands (red soil), and their response to different hydraulic loading rates (HLR) (2, 5, and 10 cm/d) were investigated. Results indicated that the soil layer had perfect performance for oxytetracycline and ciprofloxacin, yet sulfamethazine removal was unsatisfactory. Detection rates of oxytetracycline, ciprofloxacin and sulfamethazine in the effluent of simulation systems of soil layer were 8.33-36.36%, 8.33-47.83% and 100%, respectively. The model analysis of adsorption and hydrolysis indicated that physical adsorption, which was controlled by exchange reaction process based on diffusion, was the primary adsorption mechanism of target antibiotics in red soil, and the hydrolysis half-life values of antibiotics in the water of soil layer were shorter than them in wastewater. The removal response of oxytetracycline and ciprofloxacin to change of HLR was insignificant, yet the respective effluent concentrations of sulfamethazine at HLR of 2-10 cm/d were 41.90, 61.35 and 73.54 µg/L during treating synthetic livestock wastewater, which revealed significant positive correlation (P < 0.05). The relative abundances of each target resistance genes in soil showed significant increase after treating wastewater (10-5-10-6 to 10-4-10-1), and the total level of those at different HLRs (2, 5, and 10 cm/d) were 3.02 × 10-2, 7.54 × 10-2 and 8.65 × 10-1, respectively. In summary, HLR could affect the removal efficiency of partial antibiotic in soil layer of constructed wetlands, and the expression of antibiotic resistance in the soil gradually increased with increase in the HLR.


Assuntos
Poluentes Químicos da Água , Áreas Alagadas , Animais , Antibacterianos , Resistência Microbiana a Medicamentos/genética , Solo , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Poluentes Químicos da Água/análise
4.
J Environ Sci (China) ; 100: 117-130, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33279025

RESUMO

Although animal manure is applied to agricultural fields for its nutrient value, it may also contain potential contaminants. To determine the variability in such contaminants as well as in valuable nutrients, nine uncomposted manure samples from Idaho dairies collected during 2.5 years were analyzed for macro- and micro-nutrients, hormones, phytoestrogens, antibiotics, veterinary drugs, antibiotic resistance genes, and genetic elements involved in the spread of antibiotic resistance. Total N ranged from 6.8 to 30.7 (C:N of 10 to 21), P from 2.4 to 9.0, and K from 10.2 to 47.7 g/kg manure. Zn (103 - 348 mg/kg) was more abundant than Cu (56 - 127 mg/kg) in all samples. Phytoestrogens were the most prevalent contaminants detected, with concentrations fluctuating over time, reflecting animal diets. This is the first study to document the presence of flunixin, a non-steroidal anti-inflammatory drug, in solid stacked manure from regular dairy operations. Monensin was the most frequently detected antibiotic. Progesterones and sulfonamides were regularly detected. We also investigated the relative abundance of several types of plasmids involved in the spread of antibiotic resistance in clinical settings. Plasmids belonging to the IncI, IncP, and IncQ1 incompatibility groups were found in almost all manure samples. IncQ1 plasmids, class 1 integrons, and sulfonamide resistance genes were the most widespread and abundant genetic element surveyed, emphasizing their potential role in the spread of antibiotic resistance. The benefits associated with amending agricultural soils with dairy manure must be carefully weighed against the potential negative consequences of any manure contaminants.


Assuntos
Esterco , Solo , Animais , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Nutrientes , Microbiologia do Solo
5.
Huan Jing Ke Xue ; 42(1): 211-220, 2021 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-33372473

RESUMO

Owing to the long residence times of water, water reservoirs readily contribute to the accumulation of antibiotic resistant gene (ARG). It is of great public health significance to explore bacterial communities, antibiotic resistomes, and the potential public health risks of water reservoirs. In this study, metagenomic sequencing was used to analyze and compare the bacterial communities, ARG profiles, ARG-horizontal transfer, and ARG-carrying pathogens in the water and sediments of the Dongping Lake Reservoir in the dry and the wet seasons. Compared with that of the sediments, the results showed that both the bacterial communities and ARG profiles in the water were significantly influenced by the seasons, and the total ARG abundance in the dry season was significantly higher than that in the wet season. The total ARG abundance in the sediments was higher than that in water, but the horizontal transfer potential of ARG in the water was higher than that in the sediment. A total of 377 ARG subtypes belonging to 20 ARG types were found in this study. Bacitracin and vancomycin resistance genes were the main ARG types in the water and sediments, respectively, and Proteobacteria and Actinobacteria were the major ARG-carrying bacteria in the water and sediments, respectively. In addition, 30 clinical pathogens carrying ARGs were identified, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica, and Acinetobacter bohemicus. More importantly, two Escherichia coli concurrently carried virulence factor and ARG. In summary, this study revealed that a variety of ARG types existed in the Dongping Lake Reservoir, which has posed potential public health risks by contributing to the horizontal transfer of ARG and the accumulation of clinical pathogens. Therefore, it is necessary to regularly monitor the bacterial community and ARG profile in various water bodies.


Assuntos
Antibacterianos , Lagos , Acinetobacter , Antibacterianos/farmacologia , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Sedimentos Geológicos , Saúde Pública
6.
Huan Jing Ke Xue ; 42(1): 315-322, 2021 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-33372483

RESUMO

Antibiotics and antibiotic resistance genes (ARGs) are highly concerning emerging polltants. Wastewater treatment plants (WWTPs) are considered to be one of the most important anthropogenic sources of antibiotics and ARGs in the environment. Six WWTPs of a city were selected to investigate the antibiotics and ARGs in the influents and effluents, respectively. In total, 73 kinds antibiotics belonging to 7 classes were detected in WWTPs. The total concentration of those antibiotics ranged between 490.2-2288.6 ng·L-1, and ofloxacin, maprofloxacin, and roxithromycin were the most frequently detected antibiotics in the influents. A dramtic difference was observed in the antibiotic removal efficiency among the WWTPs, and the total antibiotic concentration in the effluents ranged between 260.2-1464.3 ng·L-1. Macrolides and quinolones are the main classes in the effluents, and the antibiotic concentration in the effluents was higher than that in the influents. Ten kinds of ARGs were detected in the WWTPs. Among these, sul Ⅰ was the most widely prevalent with an absolute abundance of 2.4×105-5.4×106 copies·mL-1. No significant difference in ARG abundance was observed between industrial wastewater and domesic wastewater. Furthermore, the correlation between ARG abundance and antibiotic concentrations weakened after treatment in the WWTPs.


Assuntos
Eliminação de Resíduos Líquidos , Purificação da Água , Antibacterianos , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/genética , Águas Residuárias/análise
7.
Huan Jing Ke Xue ; 42(1): 323-332, 2021 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-33372484

RESUMO

The waste sludge of municipal wastewater treatment plants is an important reservoir for antibiotic resistance genes (ARG). It is necessary to explore the fate of ARG, microbial community succession, and the correlations between them. Therefore, the distribution of ARG and the microbial community structure of waste sludge from wastewater treatment plants with A2O and A2O-MBR processes during microwave pretreatment and anaerobic digestion were studied in this research. The results showed that the occurrence of ARG and the microbial community structure were quite different in the waste sludge of A2O and A2O-MBR processes. The microwave pretreatment did not change the microbial community much, whereas the community structure of the digested sludge with pretreatment showed significant differences. Anaerobic digestion had a conformity effect on the distribution of ARG and MGE in the digested sludge with or without pretreatment. Among genes, ermF, qnrS, and blaNDM-1 were the most difficult to be reduced ARG and were prone to propagation during anaerobic digestion. The influence of biomass, ammonia nitrogen, and phosphorus on the distribution of ARG and MGE was higher than that of other environmental factors. The sludge characteristics also showed important impacts on the microbial community, especially on some genera with specific functions. These results could help people to better understand the spread and control of ARG during sludge anaerobic digestion.


Assuntos
Micro-Ondas , Esgotos , Anaerobiose , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Humanos , Eliminação de Resíduos Líquidos
8.
Ecotoxicol Environ Saf ; 207: 111310, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32937228

RESUMO

Antibiotic resistance genes (ARGs) in mariculture sediments pose a potential risk to public health due to their ability to transfer from environmental bacteria to human pathogens. Long term, this may reduce pathogen susceptibility to antibiotics in medical settings. In recent years, the poly-culture of multiple species has become a popular mariculture approach in China, thanks to its environmental and economic benefits. However, differences in microbial communities and antibiotic resistome between mono- and poly-culture systems are still unclear. In this study, microbial community composition and profiles of entire (microbial DNA) and mobile (plasmid and phage) ARGs in prawn mono- and poly-culture systems were investigated using metagenomics. The abundance of several viruses and human pathogens were enhanced in prawn poly-culture ponds, when compared to monoculture systems. In contrast, sediments from poly-culture systems had a lower diversity and ARG abundance when compared to mono-culture approaches. These ARG variations were predominantly related to mobile genetic elements. Prawn mariculture activities exerted a unique selectivity for ARGs in plasmids, and this selectivity was not influenced by culture methods. The findings of this study have important implications for the selection of mariculture systems in preventing pollution with ARGs.


Assuntos
Aquicultura , Resistência Microbiana a Medicamentos/genética , Microbiota/fisiologia , Bactérias/efeitos dos fármacos , Bacteriófagos/efeitos dos fármacos , Bacteriófagos/genética , China , Cultura , Genes Bacterianos/efeitos dos fármacos , Humanos , Metagenômica , Microbiota/efeitos dos fármacos
9.
Environ Pollut ; 270: 116278, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33333404

RESUMO

Microplastics (MPs) are found to be ubiquitous and serve as vectors for other contaminants, and the inevitable aging process changes MP properties and fates. However, whether the MPs in aging process affects the fates of antibiotic resistance gene (ARGs) in aquatic environments is poorly understood. Herein, the physicochemical property alteration of MPs being aged in landfill leachate, an important reservoir of MPs and ARGs, was investigated, and microbial community evolution and ARGs occurrence of MP surface during the aging process were analyzed. Aging process remarkably altered surface properties, including increasing specific surface areas, causing the formation of oxygen-containing groups, and changing surface morphology, which further increased the probability of microbial colonization. The bacterial assemblage on MPs showed higher biofilm-forming and pathogenic potential compared to leachate. ARGs quantification results suggested that MPs exhibited selective enrichment for ARGs in a ratio of 5.7-103 folds, and the aging process enhanced the enrichment potential. Further co-occurrence networks suggested that the existence of non-random, closer and more stable ARGs-bacterial taxa relations on MP surface affected the ARG transmission. The study of ARG partitioning on MPs indicated that extracellular DNA was a nonnegligible reservoir of ARGs attached on MP surface, and that biofilm bacterial community influenced ARGs partitioning pattern during the aging process. This study confirmed that the aging process could enhance the potential of MPs as vectors for ARGs, which would promote the holistic understanding of MP behavior and risk in natural environments.


Assuntos
Microplásticos , Poluentes Químicos da Água , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Plásticos , Poluentes Químicos da Água/análise
10.
Sci Total Environ ; 759: 144193, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33338689

RESUMO

This study aimed to investigate the influence of cropping method and substrate type on the fate and the removal of bacterial and antibiotic resistance genes (ARGs) indicators from primary wastewater by constructed wetlands (CWs) during startup and maturation stages. Four small-scale CWs differing in their plantation pattern (monoculture vs. polyculture) and substrate type were constructed and operated under field conditions. While for bacteria, the greatest impact of the cropping method and substrate type on removal was during the startup stage rather than the maturation stage, for ARGs, such impact was significant at both stages. During startup, the removal efficiencies of heterotrophic bacteria, fecal coliforms, E. coli, 16S rRNA genes and lacZ increased with the operation time. At maturation, the removal efficiencies were constant and were within the range of 89.2-99.4%, 93.7-98.9%, 89-98.8%, 94.1-99.6% and 92.9-98.7%, respectively. The removal efficiencies of intl1, tetM, intl1, sul1, ermB and total ARGs were also increased with the operation time. However, they were ARG type and configuration-dependent; at maturation they ranged between 50.7%-89.4%, 85.9%-97%, 49.6%-92.9%, 58.2%-96.7% and 79.9-94.3%, respectively. The tuff-filled serially planted CW was also the only one capable of removing these genes at similar high efficiency. Metagenomic analysis showed that none of the ARGs was among the most common ARGs in water and biofilm samples; rather most ARGs belonged to bacterial efflux transporter superfamilies. Although ARGs were removed, they were still detected in substrate biofilm and their relative concentrations were increased in the effluents. While the removal of both bacteria and ARGs was higher during summer compared to winter, the season had no effect on the removal pattern of ARGs. Hence, combination of the serial plantation with substrate having high surface area is a potential strategy that can be used to improve the performance of CWs.


Assuntos
Poluentes Químicos da Água , Áreas Alagadas , Antibacterianos , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Escherichia coli , Genes Bacterianos , RNA Ribossômico 16S/genética , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Poluentes Químicos da Água/análise
11.
Chemosphere ; 266: 129182, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33333336

RESUMO

Municipal solid waste landfill is now recognized as a significant reservoir of antibiotics and antibiotic resistance genes (ARGs). This study investigates the contamination of antibiotics resistance, in 10 leachate samples collected from four MSW landfills in north Italy spanning 34 years, including ARGs as well as mobile genetic element (MGEs). Antibiotics (0-434740 ng/L) and ARGs (5.56-6.85 × 105copies/µL leachate) were found in leachate. Abundances of the measured ARGs were found to be clustered into two groups with different changing tendencies with landfilling age in different landfills. Even though some antibiotics were banned or limited in Italy, they were found to still occur in landfills and drive the long-term contamination of ARGs indirectly, indicating the persistence of antibiotic resistance. What's more, the complexity of antibiotic resistance in leachate was found to synthetically relate to antibiotics, metals, microbes and MGEs presenting that Mn, SMX and EFC influence positively (p < 0.01) the contamination of tetW, tetQ, tetM, tetA, ermB, and cat, contributing importantly in new leachate. This study discusses the AR pollution of leachate in Italy where antibiotics are used the most in Europe, less reported in literatures. Our results suggest that a full-scale view for landfill antibiotics resistance should be considered with history of landfills, use of antibiotics and different phase in landfills, with both "relative static" and "dynamic tracking" perspective to focus on the principal antibiotic-resistance pollutants for leachate treatment, and raise the attention for landfill post-closure care and landfill mining.


Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Resistência Microbiana a Medicamentos/genética , Europa (Continente) , Itália , Resíduos Sólidos , Instalações de Eliminação de Resíduos
12.
Sci Total Environ ; 754: 142077, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32911148

RESUMO

The in-situ advanced anaerobic digestion (AAD) enhanced with zero-valent iron powder (ZVI) under mesophilic condition was investigated to remove 5 antibiotics (sulfamerazine (SMR), sulfamethoxazole (SMZ), ofloxacin (OFL), tetracycline (TC), and roxithromycin (ROX)) and 11 antibiotic resistance genes (ARGs) (AAC (6')-IB-CR, qnrS, ermF, ermT, ermX, sul1, sul2, sul3, tetA, tetB, and tetG) in sewage sludge. The effects of different ZVI dosages, antibiotic concentrations, and solid retention time (SRTs) on the removal were explored. Also, the correlation coefficient of antibiotics and ARGs, microbial community structure, biogas production and methane yield were analyzed. All conducted treatments operated stably, and the modified Gompertz model described the cumulative methane yield well. The antibiotics, with the exception of OFL, were effectively removed in the sewage sludge at a dosage of 1000 mg/L ZVI, SRT 20 d, and an antibiotic concentration of 20 µg/L during AAD. The removal rates of SMZ, SMR, TC, and ROX reached 97.39%, 74.54%, 78.61%, and 56.58%, respectively. AAC (6')-IB-CR and tetB could be effectively reduced during the in-situ AAD. Through the redundancy analysis, AAC (6')-IB-CR, ermT, ermX, sul2, tetB, and tetG had strong positive correlations with the antibiotics in the reactor. The principle component analysis revealed that the community structure was similar when the SRT was 10 d and 20 d at the same amount of ZVI and antibiotic concentrations in the sludge. Under the operating parameters of 1000 mg/L ZVI dosage, SRT 20 d, and an antibiotic concentration of 20 µg/L, Erysipelotrichia, Verrucomicrobia, Clostridia, Caldiserica, and Alphaproteobacteria of the class were dominated microorganisms in the anaerobic digestion.


Assuntos
Ferro , Esgotos , Anaerobiose , Antibacterianos , Resistência Microbiana a Medicamentos/genética
13.
Sci Total Environ ; 754: 141898, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32916483

RESUMO

Antibiotic resistance and rising CO2 levels are considered among the most significant challenges we will face in terms of global development over the following decades. However, the impact of elevated CO2 on soil antibiotic resistance has rarely been investigated. We used a free-air CO2 enrichment system to investigate the potential risks posed by applying mineral and organic fertilizers to paddy soil at current CO2 concentration (370 ppm) and future elevated CO2 (eCO2, 570 ppm predicted for 2100). Organic fertilizer substitution (substituting the mineral fertilizer by 50% N) alone increased the plant uptake and soil residue of sulfamethazine, and enriched sulfonamide resistance genes (sul1, sul2), tetracycline resistance genes (tetG, tetM) and class 1 integron (intl1). But it decreased the rice grain yield (by 7.6%). Comparatively, eCO2 decreased the sul2, tetG and intl1 gene abundances by organic fertilizer substitution, and meanwhile increased grain yield (by 8.4%). Proteobacteria and Nitrospirae were potential hosts of antibiotic resistance genes (ARGs). Horizontal gene transfer via intl1 may play an important role in ARGs spread under eCO2. Results indicated that future elevated CO2 concentration could modify the effects of organic fertilizer substitution on rice yield and soil ARGs, with unknown implications for future medicine and human health.


Assuntos
Fertilizantes , Oryza , Antibacterianos , Dióxido de Carbono/análise , Resistência Microbiana a Medicamentos/genética , Fertilizantes/análise , Solo
14.
Bioresour Technol ; 319: 124106, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32949830

RESUMO

The individual and combined impacts of copper ion (Cu2+) and oxytetracycline (OTC) on anaerobic ammonium oxidation (anammox) performance and its self-recovery process were examined. Experimental results showed that the anammox performance and activity of anammox bacteria were inhibited by 1.0 mg L-1 OTC, Cu2+ and OTC + Cu2+, and both single and combined inhibitions were reversible. The abundance of functional genes and parts of antibiotic resistance genes (ARGs) were positively related to the dominant bacterium Ca. Kuenenia, implying that the recovery of the performance was associated with the progressive induction of potentially resistant species after inhibition. The above outcomes illustrated that anammox bacteria were stressed by metals and antibiotics, but they still could remove nitrogen at a rate higher than 20.6 ± 0.8 kg N m-3 d-1, providing guidance for engineering applications of anammox processes.


Assuntos
Compostos de Amônio , Microbiota , Oxitetraciclina , Antibacterianos/farmacologia , Reatores Biológicos , Cobre , Resistência Microbiana a Medicamentos/genética , Nitrogênio , Oxirredução , Oxitetraciclina/farmacologia
15.
Bioresour Technol ; 319: 124139, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32971337

RESUMO

This study was focused on the changes of antibiotic resistance genes (ARGs) and their potential host bacteria during the swine manure composting on sub-scale farms. Eight target ARGs increased 427% on average, with a trend of increase at early stage and decrease at later stage, and the main reduction stage appeared in maturity stage. The abundance of ARGs was mainly affected by the community succession of potential host bacteria. Composting could reduce the abundance of potential host bacteria of ARGs as well as pathogens such as Pseudomonas, and reduce the environmental risks of swine manure. N/C and S levels had a positive effect on the potential host of most ARGs. Prolonging the maturity period would inhibit the growth of potential host bacteria of ARGs during composting, therefore inhibiting the transmission of ARGs.


Assuntos
Compostagem , Animais , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Fazendas , Genes Bacterianos/genética , Esterco , Suínos
16.
Chemosphere ; 263: 127936, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297016

RESUMO

Antibiotic resistance is a health challenge across human, animal and environmental settings. In the environment, metals may contribute to antibiotic resistance selection. This study aimed to investigate the role of copper and zinc in the selection of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in a riverine bacterial community. Using a microcosm approach, bacteria in water samples were exposed to 50 µg L-1 and 100 µg L-1 of copper and zinc, for 20 days. The prevalence of ARB was determined from colony forming units counts in media with and without antibiotics. A significant increase in the prevalence of cefotaxime-resistant (from 2.3% in control to 9.5% in Cu50 and 16.8% in Cu100) and tetracycline-resistant bacteria (from 0.03% to 0.23% in Cu100) was observed in communities exposed to copper. Zinc exposure resulted in an increase in the prevalence of cefotaxime-resistant bacteria (from 24.6% to 91.3% in Zn50 and 72.4% in Zn100) and of kanamycin-resistant bacteria (from 6.1% to 24.1% in Zn50 and 43% in Zn100). Cefotaxime- and kanamycin-resistant bacteria belonged to genera intrinsically resistant to these compounds. DGGE profiling confirmed that metal exposure altered the structure and diversity of bacterial communities. Changes in the abundance of genes usually associated with mobile genetic elements (blaCTX-M, blaTEM, tet(A) and intI1) were not detected after exposure. Results demonstrated the selection of bacteria intrinsically resistant to antibiotics imposed by copper and zinc exposure, suggesting an important role played by cross-resistance mechanisms.


Assuntos
Antagonistas de Receptores de Angiotensina , Genes Bacterianos , Inibidores da Enzima Conversora de Angiotensina , Animais , Antibacterianos/toxicidade , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Humanos
17.
Sci Total Environ ; 761: 144108, 2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33360136

RESUMO

Biogas digestate is a reservoir of antibiotic resistance genes (ARGs) and could pose a high health risk to both human and animals if the host microorganisms of ARGs become aerosolized. The purpose of this study was to investigate the diversity and relative abundance characteristics of aerosol-loaded ARGs from biogas digestate during storage, and to explore whether the change of ARGs in biogas digestate directly affect the dispersion of aerosol-loaded ARGs. This study reported for the first time that 28 of 42 ARG subtypes detected in the biogas digestate could be dispersed to the atmosphere via aerosol dispersion in a lab-scale dynamic emission vessels experiment. The relative abundance or diversity of ARGs in aerosols were different from that in biogas digestate, and no significant correlation were observed between the relative abundance of ARGs in biogas digestate and aerosols. The dominant ARGs were tetracycline resistance genes in biogas digestate and ß-lactam resistance genes in aerosols. The process of biogas digestate storage reduced the total relative abundance of targeted ARGs in biogas digestate, decreased by 0.35 copies/16S rRNA after 30 days of storage, but increased the abundance of some ARG subtypes, including tetM, tetX, tetQ, tetS, ermF and sul2. High-concerned ARGs, including NDM-1, mcr-1 and vancomycin resistance genes (including vanA, vanB, vanRA and vanSA), were found in biogas digestate, and NDM-1 and vanB were also detected in aerosols. These results indicated a potential risk of ARGs dispersion during biogas digestate storage. Further research on the dispersion of ARGs from biogas digestate is required to elucidate the emission mechanism and develop mitigation measures.


Assuntos
Biocombustíveis , Esterco , Animais , Antibacterianos/farmacologia , Atmosfera , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , RNA Ribossômico 16S , Suínos
18.
Bioresour Technol ; 319: 124181, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33254446

RESUMO

Antibiotic resistance genes (ARGs) are present as both intracellular and extracellular fractions of DNA in the environment. Due to the poor yield of extracellular DNA in conventional extraction methods, previous studies have mainly focused on intracellular ARGs (iARGs). In this review, we evaluate the prevalence/persistence and horizontal transfer of iARGs and extracellular ARGs (eARGs) in different environments, and then explore advanced mitigation strategies in wastewater treatment plants (WWTPs) for preventing the spread of antibiotic resistance in the environment. Although iARGs are the main fraction of ARGs in nutrient-rich environments, eARGs are predominant in receiving aquatic environments. In such environments, natural transformation of eARGs occurs with a comparable frequency to conjugation of iARGs. Further, eARGs can be adsorbed by soil and sediments particles, protected from DNase degradation, and consequently persist longer than iARGs. Collectively, these characteristics emphasize the crucial role of eARGs in the spread of antibiotic resistance in the environment. Fate of iARGs and eARGs through advanced treatment technologies (disinfection and membrane filtration) indicates that different mitigation strategies may be required for each ARG fraction to be significantly removed. Finally, comprehensive risk assessment is needed to evaluate/compare the effect of iARGs versus eARGs in the environment.


Assuntos
Antibacterianos , Genes Bacterianos , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Prevalência , Águas Residuárias
19.
J Environ Sci (China) ; 99: 51-58, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183716

RESUMO

The large-scale development in livestock feed industry has increased the chances of antibiotics and heavy metals contamination in the soil. The fate of antibiotic resistance genes (ARGs) and microbial community in heavy metals and antibiotic contaminated soil is still unclear. In this study, we investigated the effect of cadmium (Cd) addition on the transport of ARGs, microbial community and human pathogenic bacteria in oxytetracycline (OTC) contaminated soil. Results showed that the addition of OTC significantly increased the abundance of ARGs and intI1 in the soil and lettuce tissues. The addition of Cd to OTC treated soil further increased the abundance and translocation of ARGs and intI1. Moreover, Cd promoted the transfer of potential human pathogenic bacteria (HPB) into lettuce tissues. Compared with O10 treatment, the addition of Cd decreased the concentration of OTC in soil and lettuce tissue, but slightly increased the fresh weight of lettuce tissues. Redundancy analysis indicated that bacterial community succession is a major factor in ARGs variation. Network analysis indicated that the main host bacteria of ARGs were mainly derived from Proteobacteria. Correlation analysis showed that intI1 was significantly correlated with tetG, tetC, sul1, sul2, ermX, and ermQ. Meanwhile, potential HPB (Clostridium, and Burkholderia) was significantly correlated with intI1 and eight ARGs (tetG, tetC, tetW, tetX, sul1, sul2, ermX, and ermQ.). The findings of this study suggest that the addition of heavy metals to agricultural fields must be considered in order to reduce the transfer of ARGs in the soil and crops.


Assuntos
Microbiota , Oxitetraciclina , Antibacterianos/farmacologia , Cádmio/toxicidade , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Solo , Microbiologia do Solo
20.
Sci Total Environ ; 752: 142162, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33207525

RESUMO

The present study compared the effects of adding shrimp shell powder (SSP) at four levels comprising 0% (CK), 5% (L), 10% (M), and 15% (H) on the abundance of antibiotic resistance genes (ARGs) and the bacterial community succession during swine manure composting. The relative abundances of 5/11 ARGs were reduced in CK, and 7/11 in H. Moreover, the removal rate was enhanced by adding SSP. Thus, H decreased the total abundance of ARGs by 32.68%, whereas CK increased it by 6.31%. Redundancy analysis indicated that mobile genetic elements (MGEs) (46.6%) and the bacterial community (31.1%) mainly explained the changes in ARGs. H enhanced the removal of MGEs, prolonged the thermophilic phase, stabilized copper and zinc, and retained nitrogen. LEfSe analysis and non-metric multidimensional scaling indicated that the bacterial community changed in the composting process, and it was optimized by H. The abundances of the potential bacterial co-hosts (such as Lactobacillus, Corynebacterium_1, and Ornithinicoccus) of ARGs and MGEs were lower and the decomposition of organic matter was higher in H compared with CK. Thus, composting with 15% SSP can reduce the risk of ARGs and improve the practical value for agronomic application.


Assuntos
Compostagem , Animais , Antibacterianos , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Esterco , Suínos
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