NanoImpact
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2017
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IF 0
Xiaolong Wang,Fengxia Yang,Jing Zhao,Yan Xu,Daqing Mao,Xiao Zhu,Yi Luo,P.J.J. Alvarez
Bacterial exposure to ZnO nanoparticles (nZnO) at sublethal concentrations (1 to 10 mg/l) for 24 h significantly increased the conjugative frequency of antibiotic resistance plasmid RP4. A 24.3-fold increase was observed in E . coli pure cultures, and an 8.3-fold increase occurred in a mixed culture of indigenous aquatic microbiota. In addition, nZnO increased by three fold the transformation efficiency of E . coli via the uptake of naked plasmid pGEX4T-1, which was confirmed by confocal fluorescence microscopy. Enhanced horizontal transfer of resistance plasmids was a nanoparticle-specific effect, since 5.3 mg/l Zn 2 + (representing the maximum release of Zn 2 + from 10 mg/l nZnO) did not enhance RP4 transfer or pGEX4T-1 uptake frequency. This phenomenon was attributed to increased bacterial cell permeability after exposure to nZnO (but not to Zn 2 + ), which was confirmed by flow cytometry with propidium iodide staining. Overall, this study forewarns that accidental or incidental release of nZnO may facilitate environmental dissemination and propagation of antibiotic resistance genes through horizontal gene transfer.
研究领域:
微生物学
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环境科学
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分子生物学
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产品关联
DOI
JOURNAL OF HAZARDOUS MATERIALS
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2022
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IF 14.224
Yingying Zha,Ziwei Li,Zheng Zhong,Yiming Ruan,Lili Sun,Fangfang Zuo,Liangzhong Li,Sen Hou
Recently micro/nanoplastics (MNPs) have raised intensive concerns due to their possible enhancement effect on the dissemination of antibiotic genes. Unfortunately, data is still lacking to verify the effect. In the study, the influence of polystyrene MNPs on the conjugative gene transfer was studied by using E. coli DH5ɑ with RP4 plasmid as the donor bacteria and E. coli K12 MG1655 as the recipient bacteria. We found that influence of MNPs on gene transfer was size-dependent. Small MNPs (10 nm in radius) caused an increase and then a decrease in gene transfer efficiency with their concentration increasing. Moderate-sized MNPs (50 nm in radius) caused an increase in gene transfer efficiency. Large MNPs (500 nm in radius) had almost no influence on gene transfer. The gene transfer could be further enhanced by optimizing mating time and mating ratio. Scavenging reactive oxygen species (ROS) production did not affect the cell membrane permeability, indicating that the increase in cell membrane permeability was not related to ROS production. The mechanism of the enhanced gene transfer efficiency was attributed to a combined effect of the increased ROS production and the increased cell membrane permeability, which ultimately regulated the expression of corresponding genes.
研究领域:
环境科学
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微生物学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2025
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IF 12.4
Lingling Rong,Baoyin Zhang,Hongmu Qiu,Hailin Zhang,Jiayin Yu,Qing Yuan,Ligui Wu,Hong Chen,Yuanmin Mo,Xiaoming Zou,Xubiao Luo
The generational effects of antibiotics are well-documented within the field of pharmacology, but their specific influence on the enhancement of plasmid-mediated conjugative transfer remains insufficiently understood, although plasmid-mediated conjugative transfer represents a crucial process for the horizontal dissemination of antibiotic resistance genes (ARGs). We pioneeringly investigate the effects of eight tetracyclines (TCs) across three generations on the conjugative transfer of RP4 plasmid, utilizing Escherichia coli strains isolated from typical wastewater. Results indicate that TCs enhance plasmid conjugative transfer, exhibiting significant generational effects. Average hormetic zone for conjugative transfer (ΔA R ) induced by 1st-generation TCs is 4.46 to 5.95 times greater than that induced by 2nd- and 3rd-generation TCs, respectively. Furthermore, this intriguing phenomenon is unrelated to TCs’ degradation characteristics (P > 0.05), but is closely associated with bacterial biochemical responses (P < 0.05), including reactive oxygen species (ROS), cell membrane permeability, and ATP synthesis. Moreover, mechanistic results reveal that key structural parameters of TCs significantly impact their interactions with the essential protein UspD, which regulates biochemical processes and relevant genes on RP4 plasmid in donor bacteria, thereby substantially enhancing the plasmid conjugative transfer frequency and exhibiting significant generational effects (P < 0.001). Our findings shed light on the generational effects of TCs on plasmid conjugative transfer in wastewater treatment systems, offering theoretical supports for ARGs dissemination control.
研究领域:
环境科学
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微生物学
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药理学
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分子生物学
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水处理
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抗生素抗性
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产品关联
DOI
PubMed
高影响因子
Environmental Chemistry Letters
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2022
·Vol. 20
·期 3
·1553-1560
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IF 13.615
Feng Mingbao,Ye Chengsong,Zhang Shengqi,Sharma Virender K.,Manoli Kyriakos,Yu Xin
The global dissemination of antibiotic resistance is severely threatening public health. Several non-antibiotic chemicals facilitate the horizontal transfer of antibiotic resistance genes. Bisphenol analogs, e.g., bisphenol S and bisphenol AF, are known pollutants, yet their effects on the propagation and spread of antibiotic resistance genes remain unknown. Our study demonstrates for the first time that bisphenol S and bisphenol AF at environmentally relevant concentrations of 0.1–100.0 μg/L accelerates 2–5 folds the conjugative transfer frequency of RP4 plasmid-borne antibiotic resistance genes within and across bacterial genera, from Escherichia coli DH5α to Escherichia coli HB101 or Salmonella enterica . Bisphenol S and bisphenol AF exerted no effect on the bacterial growth and little change in cell membrane permeability. Accelerated conjugative transfer is explained by the repression of the global regulator, with a maximum relative expression level of 0.23, and of the vertical transfer system (0.26), with simultaneous up-regulation of DNA horizontal transfer and replication system (3.66). This bisphenols-induced conjugative transfer of antibiotic resistance genes could promote the spread of antibiotic resistance in the environment and in gut microbial communities of wildlife and human.
研究领域:
环境科学
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微生物学
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公共卫生
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分子生物学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）