Xiamen Key Laboratory of Indoor Air and Health, Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; School of Public Utilities, Jiangsu Urban and Rural Construction Vocational College, Changzhou 213147, China.
Xiamen Key Laboratory of Indoor Air and Health, Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Total Environ. 2023 Dec 20;905:167359. doi: 10.1016/j.scitotenv.2023.167359. Epub 2023 Sep 26.
The co-existence of microplastics (MPs) and antibiotics in the coastal environment poses a combined ecological risk. Single toxic effects of MPs or antibiotics on aquatic organisms have been verified, however, the exploration of their combined toxic effects remains limited. Here, foodborne polystyrene microplastics (PS-MPs, 10 μm, 0.1 % w/w in food) and waterborne tetracyclines (TC, 50 μg/L) were used to expose an estuarine fish Oryzias melastigma for four weeks. We found that the aqueous availability of TC was not significantly altered coexisting with MPs. The fish body weight gain was significantly slower in TC alone or combined groups than the control group, consistent with the lower lipid content in livers. The body length gain was significantly inhibited by the combined presence compared to the single exposure. Both exposures led to a shift of gut microbiota composition and diversity. TC and the combined group possessed similar gut microbiota which is distinct from PS-MPs and the control group. The Firmicutes/Bacteroidetes (F/B) ratio in the TC and combined groups were significantly lower compared to the control, while the PS-MPs group showed no significant impact. Metabolomic analysis of the fish liver confirmed the shift of metabolites in specific pathways after different exposures. More, a number of gut microbiota-related metabolites on lipid metabolism was perturbed, which were annotated in arachidonic acid metabolism and linoleic acid metabolism. In all, TC modulates bacterial composition in the fish gut and disturbs their liver metabolites via the gut-liver axis, which led to the slower growth of O. melastigma. More, the adverse impact was aggravated by the co-exposure to foodborne PS-MPs.
微塑料（MPs）和抗生素在沿海环境中共存，构成了一种联合的生态风险。已经验证了 MPs 或抗生素对水生生物的单一毒性作用，然而，它们联合毒性作用的探索仍然有限。在这里，我们使用食源聚苯乙烯微塑料（PS-MPs，10μm，食物中 0.1%w/w）和水四环素（TC，50μg/L）暴露河口鱼类 Oryzias melastigma 四周。我们发现，TC 与 MPs 共存时，其在水中的可用性没有明显改变。与对照组相比，仅 TC 或联合组的鱼体重增加明显较慢，这与肝脏中较低的脂质含量一致。与单一暴露相比，联合暴露显著抑制了体长的增加。两种暴露都导致了肠道微生物群落组成和多样性的变化。TC 和联合组的肠道微生物群落与 PS-MPs 和对照组相似。与对照组相比，TC 和联合组的厚壁菌门/拟杆菌门（F/B）比值明显降低，而 PS-MPs 组没有明显影响。对鱼肝脏的代谢组学分析证实，不同暴露后特定代谢途径的代谢物发生了变化。此外，一些与肠道微生物群相关的脂质代谢物发生了扰动，这些代谢物被注释为花生四烯酸代谢和亚油酸代谢。总之，TC 通过肠-肝轴调节鱼类肠道中的细菌组成，并扰乱其肝脏代谢物，导致 O. melastigma 生长缓慢。此外，食源 PS-MPs 的共同暴露加剧了这种不利影响。
