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Ahmed Y, Zhong J, Yuan Z, Guo J. Simultaneous removal of antibiotic resistant bacteria, antibiotic resistance genes, and micropollutants by a modified photo-Fenton process. WATER RESEARCH 2021; 197:117075. [PMID: 33819660 DOI: 10.1016/j.watres.2021.117075] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 03/12/2021] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Although photo-driven advanced oxidation processes (AOPs) have been developed to treat wastewater, few studies have investigated the feasibility of AOPs to simultaneously remove antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs) and micropollutants (MPs). This study employed a modified photo-Fenton process using ethylenediamine-N,N'-disuccinic acid (EDDS) to chelate iron(III), thus maintaining the reaction pH in a neutral range. Simultaneous removal of ARB and associated extracellular (e-ARGs) and intracellular ARGs (i-ARGs), was assessed by bacterial cell culture, qPCR and atomic force microscopy. The removal of five MPs was also evaluated by liquid chromatography coupled with mass spectrometry. A low dose comprising 0.1 mM Fe(III), 0.2 mM EDDS, and 0.3 mM hydrogen peroxide (H2O2) was found to be effective for decreasing ARB by 6-log within 30 min, and e-ARGs by 6-log within 10 min. No ARB regrowth occurred after 48-h, suggesting that the proposed process is an effective disinfectant against ARB. Moreover, five recalcitrant MPs (carbamazepine, diclofenac, sulfamethoxazole, mecoprop and benzotriazole at an initial concentration of 10 μg/L each) were >99% removed after 30 min treatment in ultrapure water. The modified photo-Fenton process was also validated using synthetic wastewater and real secondary wastewater effluent as matrices, and results suggest the dosage should be doubled to ensure equivalent removal performance. Collectively, this study demonstrated that the modified process is an optimistic 'one-stop' solution to simultaneously mitigate both chemical and biological hazards.
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Affiliation(s)
- Yunus Ahmed
- Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
| | - Jiexi Zhong
- Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
| | - Jianhua Guo
- Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia.
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Wang Y, Lu J, Engelstädter J, Zhang S, Ding P, Mao L, Yuan Z, Bond PL, Guo J. Non-antibiotic pharmaceuticals enhance the transmission of exogenous antibiotic resistance genes through bacterial transformation. THE ISME JOURNAL 2020; 14:2179-2196. [PMID: 32424247 PMCID: PMC7367833 DOI: 10.1038/s41396-020-0679-2] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 12/19/2022]
Abstract
Antibiotic resistance is a serious global threat for public health. Considering the high abundance of cell-free DNA encoding antibiotic resistance genes (ARGs) in both clinical and environmental settings, natural transformation is an important horizontal gene transfer pathway to transmit antibiotic resistance. It is acknowledged that antibiotics are key drivers for disseminating antibiotic resistance, yet the contributions of non-antibiotic pharmaceuticals on transformation of ARGs are overlooked. In this study, we report that some commonly consumed non-antibiotic pharmaceuticals, at clinically and environmentally relevant concentrations, significantly facilitated the spread of antibiotic resistance through the uptake of exogenous ARGs. This included nonsteroidal anti-inflammatories, ibuprofen, naproxen, diclofenac, the lipid-lowering drug, gemfibrozil, and the β-blocker propranolol. Based on the results of flow cytometry, whole-genome RNA sequencing and proteomic analysis, the enhanced transformation of ARGs was affiliated with promoted bacterial competence, enhanced stress levels, over-produced reactive oxygen species and increased cell membrane permeability. In addition, a mathematical model was proposed and calibrated to predict the dynamics of transformation during exposure to non-antibiotic pharmaceuticals. Given the high consumption of non-antibiotic pharmaceuticals, these findings reveal new concerns regarding antibiotic resistance dissemination exacerbated by non-antibiotic pharmaceuticals.
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Affiliation(s)
- Yue Wang
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Ji Lu
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jan Engelstädter
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Shuai Zhang
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Pengbo Ding
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Likai Mao
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Philip L Bond
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jianhua Guo
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia.
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Ambur OH, Engelstädter J, Johnsen PJ, Miller EL, Rozen DE. Steady at the wheel: conservative sex and the benefits of bacterial transformation. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0528. [PMID: 27619692 PMCID: PMC5031613 DOI: 10.1098/rstb.2015.0528] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2016] [Indexed: 12/25/2022] Open
Abstract
Many bacteria are highly sexual, but the reasons for their promiscuity remain obscure. Did bacterial sex evolve to maximize diversity and facilitate adaptation in a changing world, or does it instead help to retain the bacterial functions that work right now? In other words, is bacterial sex innovative or conservative? Our aim in this review is to integrate experimental, bioinformatic and theoretical studies to critically evaluate these alternatives, with a main focus on natural genetic transformation, the bacterial equivalent of eukaryotic sexual reproduction. First, we provide a general overview of several hypotheses that have been put forward to explain the evolution of transformation. Next, we synthesize a large body of evidence highlighting the numerous passive and active barriers to transformation that have evolved to protect bacteria from foreign DNA, thereby increasing the likelihood that transformation takes place among clonemates. Our critical review of the existing literature provides support for the view that bacterial transformation is maintained as a means of genomic conservation that provides direct benefits to both individual bacterial cells and to transformable bacterial populations. We examine the generality of this view across bacteria and contrast this explanation with the different evolutionary roles proposed to maintain sex in eukaryotes. This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.
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Affiliation(s)
- Ole Herman Ambur
- Department of Life Sciences and Health, Oslo and Akershus University College of Applied Sciences, 1478 Oslo, Norway
| | - Jan Engelstädter
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Pål J Johnsen
- Faculty of Health Sciences, Department of Pharmacy, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Eric L Miller
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Daniel E Rozen
- Institute of Biology, Leiden University, 2333 BE Leiden, The Netherlands
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