中国农业科学 ›› 2024, Vol. 57 ›› Issue (20): 4145-4160.doi: 10.3864/j.issn.0578-1752.2024.20.018

• 畜牧·兽医 • 上一篇    

黄曲霉毒素B1对仔猪体内流感病毒复制、器官损伤和肠道菌群的影响

赵文硕(), 张金龙, 姚兆然, 宋宇琪, 吕顺, 刘迎雪, 袁聪聪, 孙雨航*()   

  1. 沈阳农业大学动物科学与医学学院,沈阳 110866
  • 收稿日期:2024-04-17 接受日期:2024-08-25 出版日期:2024-10-16 发布日期:2024-10-24
  • 通信作者:
    孙雨航,E-mail:
  • 联系方式: 赵文硕,E-mail:z13942923144@163.com。
  • 基金资助:
    国家自然科学基金青年项目(32002347); 中国博士后科学基金面上项目(2023M741095); 中国博士后科学基金面上项目(2021M692231)

Effects of Aflatoxin B1 on Influenza Virus Replication, Organ Damages and Intestinal Microbiota Disorder of Swine

ZHAO WenShuo(), ZHANG JinLong, YAO ZhaoRan, SONG YuQi, LÜ Shun, LIU YingXue, YUAN CongCong, SUN YuHang*()   

  1. College of Animal Science and Medicine, Shenyang Agricultural University, Shenyang 110866
  • Received:2024-04-17 Accepted:2024-08-25 Published:2024-10-16 Online:2024-10-24

摘要:

【背景】黄曲霉毒素B1(AFB1)是由寄生曲霉菌产生的次级代谢产物,广泛存在于世界各地受污染的食品和饲料中,被认为是影响人类和动物健康的主要风险因素之一。猪流感病毒(SIV)是目前世界上传播最为广泛的病毒之一,其复制易受环境和营养等多种因素影响。然而,饲料中AFB1污染与SIV感染的关系尚不明确。【目的】探究AFB1暴露对SIV感染的仔猪体内SIV复制、器官损伤和肠道菌群的影响,为研究霉菌毒素中毒机制奠定基础,也为探讨其他感染性疾病易感性增加原因提供参考。【方法】选取保育期雄性仔猪32头,随机分为4组(每组8头),在试验开始第1和第4天分别滴鼻接种低致病性SIV病毒稀释液,建立SIV感染仔猪(本体动物)模型。每天新鲜稀释AFB1,按照0、10、20和40 μg·kg-1(饲料)浓度灌服给仔猪,持续21 d。分别在第7、14和21天饲喂前对仔猪进行称重,然后应用多种技术手段检测各组仔猪器官脏器指数、剖检变化和病理特征,并在此基础上,进一步使用免疫印迹分析肺部SIV的核衣壳蛋白(NP)的表达情况以及16S rRNA检测肠道菌群变化,阐明AFB1暴露对SIV感染、脏器损伤和肠道菌群的影响。【结果】暴露于40 μg·kg-1 AFB1的仔猪较对照组仔猪(无AFB1)体增重显著降低(P<0.01),NP蛋白表达以及肺脏指数显著升高(P<0.01),而脾脏指数显著降低(P<0.01)。剖检结果显示,暴露于40 μg·kg-1 AFB1仔猪的脾脏、肝脏和肺脏损伤严重。H.E染色也表现出相似的结果,与SIV对照组相比,40 μg·kg-1 AFB1处理组仔猪脾脏出现淤血,红白髓界限不清;肝组织出血、炎症细胞浸润;肺脏小肺泡融合成形态不规则的大肺泡,肺泡间质增厚,炎性细胞浸润增多;此外,肠绒毛形状不规则,结缔组织松散,有淋巴细胞浸润。16S rRNA测序结果显示,暴露于40 μg·kg-1 AFB1显著提高了仔猪肠道放线菌门和梭状芽孢杆菌的相对丰度,降低了乳酸菌属和拟杆菌属的丰度。【结论】AFB1暴露降低了SIV感染仔猪的体增重,促进SIV复制,加剧了肺组织等器官损伤,并引起肠道菌群紊乱,该发现为研究AFB1的毒性作用机制提供理论参考依据。

关键词: 黄曲霉毒素B1, 猪流感病毒, 病毒复制, 脏器损伤, 16S rRNA, 肠道菌群

Abstract:

【Background】 Aflatoxin B1 (AFB1) is a secondary metabolite produced by Aspergillus parasiticus, which is widely found in contaminated food and feed all over the world and is considered one of the major risk factors affecting human and animal health. The swine influenza virus (SIV) is currently one of the most widespread viruses in the world, and its replication is susceptible to environmental and nutritional factors. However, the relationship between AFB1 contamination in feed and SIV infection is not clear.【Objective】The objective of this study was to investigate the effects of AFB1 exposure on SIV replication, organs damage and intestinal microbiota, so as to lay a foundation for the study on the mechanism of mycotoxin poisoning, and also provide a reference for exploring the reasons for the increase in susceptibility to other infectious diseases. 【Method】 In this study, thirty-two male piglets were randomly divided into 4 groups (8 piglets in each group), the low-pathogenic SIV virus dilution was inoculated on the first and fourth day of the trial, and established a piglet model of SIV infection (the natural host of SIV). AFB1 was freshly diluted daily and and given 0, 10, 20 and 40 μg·kg-1 (feed) AFB1 to piglets for 21 days. The piglets were weighed before feeding at 7, 14 and 21 days, respectively, and used a variety of technologies to assess the effects of dietary AFB1 exposure on the weight gain, SIV replication, organs index, autopsy changes, and pathological characteristics, On this basis, the expression of nucleoprotein (NP) of SIV in the lungs were further analyzed by Western blotting and the changes of intestinal microbiota were detected by 16S rRNA, thereby elucidate the effect of AFB1 exposure on SIV infection, organ damage, and intestinal microbiota. 【Result】The results showed that piglets exposed to 40 μg·kg-1AFB1 had significantly lower weight gain (P<0.01), the expression of NP and lung index of SIV were significantly higher (P<0.01), and the spleen index was significantly lower than those exposed to 0 μg·kg-1AFB1 (P<0.01); The results of autopsy showed severe spleen, liver and lung damage in piglets exposed to 40 μg·kg-1 AFB1; HE-stained also showed similar results, compared with the SIV control group, 40 μg·kg-1 AFB1 treatment group showed congestion in the spleen, the red and white pulp were not clear; the liver tissue was hemorrhage, inflammatory cells were infiltrated; the small alveoli of the lungs fused into large alveoli with irregular morphology, the alveolar interstitium was thickened, and the inflammatory cell infiltration was increased; in addition, the intestinal villi were irregularly shaped, the connective tissue was loose, and there was lymphocytic infiltration. The results from 16S rRNA sequencing showed that the exposure to 40 μg·kg-1 AFB1 significantly increased the relative abundance of Actinomycetota and Clostridium in the intestinal tract of piglets, and decreased the abundance of Lactobacillus and Bacteroidetes. 【Conclusion】Taken together, our results suggest that AFB1 exposure can reduce the body weight gain, promote SIV replication, aggravated the damage of lung tissue and other organs, and cause intestinal microbiota disorders, which provided a theoretical reference for the study of the toxic mechanism of AFB1.

Key words: aflatoxin B1, swine influenza virus, virus replication, organs damage, 16S rRNA, intestinal microbiota