摘要

       抗生素耐药性对全球公共卫生构成严重威胁，抗生素耐药性决定因素可以通过废水排放进入自然水生系统。与市政废水相比，医院废水尤其预计含有高丰度的抗生素抗性基因 (ARG)，因为它含有人类肠道细菌，其中可能包括源自医院患者的抗生素抗性生物体，并且还可能含有高浓度的抗生素和抗微生物剂。到市政污水。病毒在废水处理系统中也发挥着重要作用，因为它们可以通过杀死细菌、促进生物体之间遗传物质的转导以及改变细菌作为原噬菌体的染色体含量来影响细菌群落组成。然而，人们对医院废水系统中 ARG、病毒及其相关细菌之间的命运和联系知之甚少。为了解决这一知识差距，我们使用鸟枪宏基因组学对以色列一个试点规模的医院废水处理系统中从进水到出水的 ARG、dsDNA 病毒和细菌的组成和持久性进行了表征。结果表明，在整个中试规模系统的所有采样位置都检测到 ARG，包括赋予对具有高度临床相关性的抗生素产生抗性的基因，流入和流出之间每个基因组当量的 ARG 总体消耗仅 16%。在整个系统中检测到的最常见的 ARG 类别赋予对氨基糖苷类、头孢菌素、大环内酯、青霉烯和四环素抗生素的抗性。与流入物中相比，流出物中更大比例的总 ARG 与质粒相关基因相关。在该系统的病毒宏基因组中没有发现病毒序列和 ARG 之间的强关联，这表明噬菌体可能不是该系统中 ARG 转移的重要载体。中试规模系统中的大多数病毒属于肌病毒科、足状病毒科和丝状病毒科。 Gammaproteobacteria 是携带 ARG 的主要细菌类别，也是所有样本中最常见的假定病毒宿主，其次是杆菌和 Betaproteobacteria。在总细菌群落中，每个样品的优势类别是 Betaproteobacteria。总的来说，我们发现各种不同类型的 ARG 和病毒在整个医院废水处理系统中持续存在，它们可以通过污水排放释放到环境中。

       Antibiotic resistance poses a serious threat to global public health, and antibiotic resistance determinants can enter natural aquatic systems through discharge of wastewater effluents. Hospital wastewater in particular is expected to contain high abundances of antibiotic resistance genes (ARGs) compared to municipal wastewater because it contains human enteric bacteria that may include antibiotic-resistant organisms originating from hospital patients, and can also have high concentrations of antibiotics and antimicrobials relative to municipal wastewater. Viruses also play an important role in wastewater treatment systems since they can influence the bacterial community composition through killing bacteria, facilitating transduction of genetic material between organisms, and modifying the chromosomal content of bacteria as prophages. However, little is known about the fate and connections between ARGs, viruses, and their associated bacteria in hospital wastewater systems. To address this knowledge gap, we characterized the composition and persistence of ARGs, dsDNA viruses, and bacteria from influent to effluent in a pilot-scale hospital wastewater treatment system in Israel using shotgun metagenomics. Results showed that ARGs, including genes conferring resistance to antibiotics of high clinical relevance, were detected in all sampling locations throughout the pilot-scale system, with only 16% overall depletion of ARGs per genome equivalent between influent and effluent. The most common classes of ARGs detected throughout the system conferred resistance to aminoglycoside, cephalosporin, macrolide, penam, and tetracycline antibiotics. A greater proportion of total ARGs were associated with plasmid-associated genes in effluent compared to in influent. No strong associations between viral sequences and ARGs were identified in viral metagenomes from the system, suggesting that phage may not be a significant vector for ARG transfer in this system. The majority of viruses in the pilot-scale system belonged to the families Myoviridae, Podoviridae, and Siphoviridae. Gammaproteobacteria was the dominant class of bacteria harboring ARGs and the most common putative viral host in all samples, followed by Bacilli and Betaproteobacteria. In the total bacterial community, the dominant class was Betaproteobacteria for each sample. Overall, we found that a variety of different types of ARGs and viruses were persistent throughout this hospital wastewater treatment system, which can be released to the environment through effluent discharge.

https://www.frontiersin.org/articles/10.3389/fmicb.2020.00153/full?utm_source=S-TWT&utm_medium=SNET&utm_campaign=ECO_FCIMB_XXXXXXXX_auto-dlvrit