Increased expression of antibiotic-resistance genes in biofilm communities upon exposure to cetyltrimethylammonium bromide (CTAB) and other stress conditions
Increased expression of antibiotic-resistance genes in biofilm communities upon exposure to cetyltrimethylammonium bromide (CTAB) and other stress conditions
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DOI：
10.1016/j.scitotenv.2020.144264
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发表时间：
2021-01-05
影响因子：
9.8
通讯作者：
Rittmann, Bruce E.
中科院分区：
文献类型：
--
作者：
Luo, Yi-Hao;Lai, YenJung Sean;Rittmann, Bruce E.
季铵化合物（QAC，例如，十六烷基三甲基溴化铵（CTAB））广泛用作表面活性剂和消毒剂。QAC已经在废水中普遍存在，并且它们的浓度可能会增加，因为QAC被推荐用于抑制SARS-CoV-2（COVID-19）病毒。细菌暴露于QAC可导致抗生素耐药基因（ARG）增殖。特别是，O-2-膜生物膜反应器（O-2-MBfRs）实现了优异的CTAB生物降解，但ARG增加在其生物膜。在这里，我们应用元转录组学分析，以评估的影响，CTAB暴露和操作条件对微生物群落的组成和ARG表达的O-2-MBfRs。两种条件致病菌，铜绿假单胞菌和嗜麦芽寡养单胞菌，占主导地位的微生物群落，并与ARG的存在。对生物膜施加应力的操作条件，即，O-2和氮的有限供应或高负荷的CTAB导致ARG表达的大幅增加，特别是对于赋予抗肿瘤靶保护的基因。外排泵中重要的是抗性结瘤分裂（RND）家族，其可能在从细胞中输出CTAB中起作用。氧化应激通过选择固有抗性物种和增强ARG的表达，似乎是触发ARG增殖的关键因素。我们的研究结果表明，手段，以减轻ARG的传播，如在这里显示的O-2为基础的膜生物膜反应器，需要考虑的压力源的影响，包括QAC暴露和紧张的操作条件。(C)2020 Elsevier B. V.保留所有权利。
Quaternary ammonium compounds (QAC, e.g., cetyltrimethylammonium bromide, (CTAB)) are widely used as surfactants and disinfectants. QAC already are commonly found in wastewaters, and their concentration could increase, since QAC are recommended to inactivate the SARS-CoV-2 (COVID-19) virus. Exposure of bacteria to QAC can lead to proliferation of antibiotic resistance genes (ARG). In particular, O-2-based membrane biofilm reactors (O-2-MBfRs) achieved excellent CTAB biodegradation, but ARG increased in their biofilms. Here, we applied meta-transcriptomic analyses to assess the impacts of CTAB exposure and operating conditions on microbial community's composition and ARG expression in the O-2-MBfRs. Two opportunistic pathogens, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, dominated the microbial communities and were associated with the presence of ARG. Operating conditions that imposed stress on the biofilms, i.e., limited supplies of O-2 and nitrogen or a high loading of CTAB, led to large increases in ARG expression, particularly for genes conferring antibiotic-target protection. Important within the efflux pumps was the Resistance-Nodulation-Division (RND) family, which may have been active in exporting CTAB from cells. Oxidative stress appeared to be the key factor that triggered ARG proliferation by selecting intrinsically resistant species and accentuating the expression of ARG. Our findings suggest that means to mitigate the spread of ARG, such as shown here in a O-2-based membrane biofilm reactor, need to consider the impacts of stressors, including QAC exposure and stressful operating conditions. (C) 2020 Elsevier B.V. All rights reserved.