Pyraclostrobin (PYR) is a strobilurin fungicide that is commonly used in agriculture, and its use in agriculture may lead to an increase in its residue in the aquatic environment and may have a deleterious influence on the intestinal health of aquatic creatures. Here, common carp were chronically exposed to PYR (0, 0.5, or 5.0 μg/L) for 30 d to determine its effect on the physical and immunological barrier and intestinal microbiota in the intestine. PYR exposure caused significant histological changes; altered the mRNA expression levels of , and (); induced oxidative stress in the common carp intestine; and increased the serum D-lactate and diamine oxidase (DAO) levels. Moreover, PYR significantly increased the protein expression levels of tumour necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and IL-6 while decreasing the level of transforming growth factor beta (TGF-β). Further studies revealed that PYR significantly reduced lysozyme (LZM) and acid phosphatase (ACP) activities as well as complement 3 (C3) and immunoglobulin M (IgM) levels. Furthermore, PYR decreased gut microbial diversity while increasing the abundance of pathogenic bacteria such as and , causing an intestinal microbial disturbances in common carp. These results imply that PYR has a negative impact on fish intestinal health and may pose serious health risks to fish by disrupting the intestinal microbiota, physical barrier, and immunological barrier in common carp.

中文翻译：

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唑菌胺酯对鲤鱼（Cyprinus carpio L.）肠道健康和肠道微生物群的影响

吡唑醚菌酯（PYR）是农业中常用的甲氧基丙烯酸酯类杀菌剂，其在农业中的使用可能会导致其在水生环境中的残留量增加，并可能对水生生物的肠道健康产生有害影响。在这里，鲤鱼长期暴露于 PYR（0、0.5 或 5.0 μg/L）30 天，以确定其对肠道物理和免疫屏障以及肠道微生物群的影响。PYR 暴露引起显着的组织学变化；改变了 、 和 () 的 mRNA 表达水平；在鲤鱼肠道中诱导氧化应激；并增加血清D-乳酸和二胺氧化酶（DAO）水平。此外，PYR 显着增加肿瘤坏死因子 α (TNF-α)、白细胞介素 1 β (IL-1β) 和 IL-6 的蛋白表达水平，同时降低转化生长因子 β (TGF-β) 的水平。进一步的研究表明，PYR 显着降低溶菌酶 (LZM) 和酸性磷酸酶 (ACP) 活性以及补体 3 (C3) 和免疫球蛋白 M (IgM) 水平。此外，PYR 降低了肠道微生物多样性，同时增加了 和 等病原菌的丰度，导致鲤鱼肠道微生物紊乱。这些结果表明，PYR 对鱼类肠道健康有负面影响，并可能通过破坏鲤鱼的肠道微生物群、物理屏障和免疫屏障，对鱼类造成严重的健康风险。