College of Fisheries, Huazhong Agricultural University, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
College of Fisheries, Huazhong Agricultural University, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China; Central Laboratory for Environmental Quality Monitoring "CLEQM" National Water Research Center "NWRC" Cairo, Egypt.
Aquat Toxicol. 2019 Jan;206:186-194. doi: 10.1016/j.aquatox.2018.11.014. Epub 2018 Nov 15.
Microcystin-LR (MC-LR) is regarded as one of the most toxic microcystins (MCs) isoforms. Microcystins could cause multiple organs dysfunction, and more attention has been drawn to the toxic effects on the gastrointestinal disorder. By using ex vivo everted gut sac model in 6 fish (Carassius auratus, Megalobrama amblycephala, Hypophthalmichthys molitrix, Aristichthys nobilis, Ctenopharyngodon idellus and Cyprinus carpio) and determining the accumulation of MC-LR in zebrafish intestine, we found a dose-dependent manner in the absorption and accumulation of MC-LR. Until now, little studies have been reported concerning the gut microbiota composition caused by different MC-LR exposure. The present study is the first time characterized the phylogenetic composition and taxonomic of the bacterial communities growth in the intestines of zebrafish treated with MC-LR using 16S rRNA pyrosequencing. After 30 days of treatment with 0, 1, 5 or 20 μg/L MC-LR, the alpha and beta diversity did not generate significant differences, indicating the existence of a core microbiota. However, db-RDA analysis showed that treatment with 20 μg/L MC-LR changed the characteristics of high abundances microbiota. The expression of Oatp2b1, stress related enzyme activities in gut and their associations with gut microbiota were also determined. The identified phylotypes including Actinobacteria, Lactobacillus and some opportunistic pathogens highlight the increasing risks of pathogen invasion and recovery tendency via potential probiotics resistance in zebrafish exposed to MC-LR.
微囊藻毒素-LR (MC-LR) 被认为是最具毒性的微囊藻毒素 (MCs) 同工型之一。微囊藻毒素可导致多个器官功能障碍，对胃肠道紊乱的毒性作用受到了更多关注。本研究通过使用 6 种鱼类（金鱼、团头鲂、草鱼、鳊鱼、鲤鱼和鲫鱼）的离体外翻肠囊模型，以及测定 MC-LR 在斑马鱼肠道中的积累，发现 MC-LR 的吸收和积累呈剂量依赖性。到目前为止，关于不同 MC-LR 暴露引起的肠道微生物群组成的研究很少。本研究首次利用 16S rRNA 焦磷酸测序技术，描述了 MC-LR 处理的斑马鱼肠道中细菌群落的系统发育组成和分类。在 0、1、5 或 20μg/L MC-LR 处理 30 天后，α 和 β 多样性没有产生显著差异，表明存在核心微生物群。然而，db-RDA 分析表明，20μg/L MC-LR 处理改变了高丰度菌群的特征。还测定了 Oatp2b1 的表达、肠道中与应激相关的酶活性及其与肠道微生物群的关系。鉴定的菌群包括放线菌、乳杆菌和一些机会性病原体，这突出表明斑马鱼暴露于 MC-LR 后，病原体入侵的风险增加，通过潜在的益生菌耐药性恢复的趋势。
