减少向环境中释放抗生素和抗生素耐药基因的管理措施

[背景]全球越来越关注污染土壤、水环境对抗生素耐药性产生和蔓延的作用。[目的]本研究的目的是确定那些可以减少抗生素和抗生素耐药性经环境途径传播影响因素的管理措施,以最终达到延长抗生素使用寿命的目标。此外还研究了实施这些措施的激励和阻碍因素。[方法]着重研究有关农业源头限制,生活、医院和工业废水处理,以及水产养殖三方面的管理措施。[讨论]我们确定了若干措施,如养份管理、径流控制和基础设施升级。凡适当处,可提供世界不同地区的典型实例。研究还强调了监测和验证管理策略有效性的重要性。最后,介绍了一则瑞典的案例研究,展示了通过沟通来发动利益相关方参与和促进行动的重要作用。[结论]在许多情况下,可以花费很少或根本不花费成本来减少抗生素和抗生素耐药性细菌的环境释放。一些管理措施与现有的政策和目标协同作用。预期的效益是延长现有和未来的抗生素使用寿命。虽然往往难以量化所降低的风险,但是全球抗生素耐药性相关发病率和死亡率加速增长,这一情况的严重程度强烈表明采取行动的必要性。

Stable oligonucleotide-functionalized gold nanosensors for environmental biocontaminant monitoring

The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes（ARGs） is a public health concern that highlights the need for improved monitoring strategies. Here, we demonstrate the environmental stability and applicability of an oligonucleotide-functionalized gold nanosensor. The mec A ARG was targeted as model biocontaminant due to its presence in clinically-relevant pathogens and to its emergence as an environmental contaminant.mec A-specific nanosensors were tested for antibiotic resistance gene（ARG） detection in ARG-spiked effluent from four wastewater treatment plants（WWTPs）. The mec A-specific nanosensors showed stability in environmental conditions and in high ionic strength（[MgCl_2] 〈 50 m M）, and high selectivity against mismatched targets. Spectrophotometric detection was reproducible with an LOD of 70 pM（≈ 4 × 10~7 genes/μL）, even in the presence of interferences associated with non-target genomic DNA and complex WWTP effluent. This contribution supports the environmental applicability of a new line of cost-effective, field-deployable tools needed for wide-scale biocontaminant monitoring.

Degradation of extracellular genomic, plasmid DNA and specific antibiotic resistance genes by chlorination

There is a need to improve understanding of the effect of chlorine disinfection on antibiotic resistance genes (ARGs) in order to advance relevant drinking water, wastewater, and reuse treatments. However, few studies have explicitly assessed the physical effects on the DNA. Here we examined the effects of free chlorine (1-20 mg CI2/L) on extracellular genomic, plasmid DNA and select ARGs. Chlorination was found to decrease the fluorometric signal of extracellular genomic and plasmid DNA (ranging from 0.005 to 0.05 μg/mL) by 70%, relative to a no-chlorine control. Resulting DNA was further subject to a fragment analysis using a Bioanalyzer, indicating that chlorination resulted in fragmentation. Moreover, chlorine also effectively deactivated both chromosomal- and plasmidborne ARGs, mecK and tetA., respectively. For concentrations >2 mg CI2//L× 30 min, chlorine efficiently reduced the qPCR signal when the initial concentration of ARGs was 10^5 copies/μL or less. Notably, genomic DNA and mecA gene signals were more readily reduced by chlorine than the plasmid-bome tetK gene (by ~2 fold). Based on the results of qPCR with short (~200 bps) and long amplicons (-1200 bps), chlorination could destroy the integrity of ARGs, which likely reduces the possibility of natural transformation. Overall, our findings strongly illustrate that chlorination could be an effective method for inactivating extracellular chromosomal- and plasmid-bome DNA and ARGs.