International Research Center for Marine Biosciences, College of Fisheries and Life Science at Shanghai Ocean University, Ministry of Science and Technology, Shanghai 201306, China; Key laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China.
CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, Yantai 264003, China.
Sci Total Environ. 2023 Jul 1;880:163304. doi: 10.1016/j.scitotenv.2023.163304. Epub 2023 Apr 6.
Antibiotics and nanoplastics (NPs) are among the two most concerned and studied marine emerging contaminants in recent years. Given the large number of different types of antibiotics and NPs, there is a need to apply efficient tools to evaluate their combined toxic effects. Using the thick-shelled mussel (Mytilus coruscus) as a marine ecotoxicological model, we applied a battery of fast enzymatic activity assays and 16S rRNA sequencing to investigate the biochemical and gut microbial response of mussels exposed to antibiotic norfloxacin (NOR) and NPs (80 nm polystyrene beads) alone and in combination at environmentally relevant concentrations. After 15 days of exposure, NPs alone significantly inhibited superoxide dismutase (SOD) and amylase (AMS) activities, while catalase (CAT) was affected by both NOR and NPs. The changes in lysozyme (LZM) and lipase (LPS) were increased over time during the treatments. Co-exposure to NPs and NOR significantly affected glutathione (GSH) and trypsin (Typ), which might be explained by the increased bioavailable NOR carried by NPs. The richness and diversity of the gut microbiota of mussels were both decreased by exposures to NOR and NPs, and the top functions of gut microbiota that were affected by the exposures were predicted. The data fast generated by enzymatic test and 16S sequencing allowed further variance and correlation analysis to understand the plausible driving factors and toxicity mechanisms. Despite the toxic effects of only one type of antibiotics and NPs being evaluated, the validated assays on mussels are readily applicable to other antibiotics, NPs, and their mixture.
抗生素和纳米塑料（NPs）是近年来人们最为关注和研究的两种海洋新兴污染物。鉴于抗生素和 NPs 的种类繁多，需要应用有效的工具来评估它们的联合毒性效应。本研究以厚壳贻贝（Mytilus coruscus）为海洋生态毒理学模型，采用一系列快速酶活性测定和 16S rRNA 测序技术，研究了在环境相关浓度下，单独及联合暴露于抗生素诺氟沙星（NOR）和 NPs（80nm 聚苯乙烯珠）的贻贝的生化和肠道微生物响应。暴露 15 天后，单独暴露 NPs 显著抑制了超氧化物歧化酶（SOD）和淀粉酶（AMS）活性，而过氧化氢酶（CAT）则同时受到 NOR 和 NPs 的影响。溶菌酶（LZM）和脂肪酶（LPS）随时间推移而增加。NOR 和 NPs 的共同暴露显著影响了谷胱甘肽（GSH）和胰蛋白酶（Typ），这可能是由于 NPs 携带的生物可利用 NOR 增加所致。NOR 和 NPs 暴露均降低了贻贝肠道微生物的丰富度和多样性，预测了受暴露影响的肠道微生物的主要功能。酶活性测定和 16S 测序快速产生的数据允许进一步进行方差和相关性分析，以了解可能的驱动因素和毒性机制。尽管仅评估了一种抗生素和 NPs 的毒性效应，但已验证的贻贝测定方法可轻松应用于其他抗生素、NPs 及其混合物。
