嗜水气单胞菌感染大口黑鲈肠炎模型的建立及评价  

Establishment and Evaluation of Enteritis Model of Largemouth Bass by Aeromonas hydrophila Infection

作　　者：黄双慧 李书含 周永恒 黎秋男 耿毅[1] 黄小丽[2] 陈德芳[2] 欧阳萍[1] HUANG Shuanghui;LI Shuhan;ZHOU Yongheng;LI Qiunan;GENG Yi;HUANG Xiaoli;CHEN Defang;OUYANG Ping(College of Veterinary Medicine,Sichuan Agricultural University,Chengdu 611130,China;College of Animal Science and Technology,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]四川农业大学动物医学院,成都611130 [2]四川农业大学动物科技学院,成都611130

出　　处：《四川农业大学学报》2024年第4期886-898,共13页Journal of Sichuan Agricultural University

基　　金：成都市科技局项目(2022YF0501021SN)。

摘　　要：【目的】采用嗜水气单胞菌(Aeromonas hydrophila)感染建立稳定大口黑鲈(Micropterus salmoides)的细菌性肠炎模型,并确定导致肠炎发生的细菌浓度和作用时间。【方法】150尾健康的大口黑鲈随机分为5组:对照组和4个试验组(感染浓度分别为1×10^(8)、1×10^(7)、1×10^(6)和1×10^(5) CFU/mL),通过腹腔注射方式进行人工感染。通过临床症状、剖检病变及评分、组织学变化及评分、肠道组织超微结构变化和炎症因子基因表达量评价各试验组造模效果。【结果】攻毒后试验组表现出游动慢,摄食下降的现象,且在攻毒第2和第3天时,1×10^(8) CFU/mL攻毒组有死亡现象。剖检后可见肛门红肿、外突,腹鳍和腹部皮肤出血等症状,肠道充血、出血,部分可见肠液潴留等。各组大体病理得分与细菌的感染浓度呈正相关,与感染时间呈负相关。组织学观察可见肠道固有层充血、水肿、增厚,并伴有炎性细胞浸润,黏膜上皮损伤脱落、细胞变性、坏死、增生,杯状细胞数目明显增加;组织病理得分随细菌浓度升高而升高,随感染时间呈现先上升后下降的趋势,在感染第5天得分最高。肠道组织超微结构变化显示,攻毒组肠道微绒毛损伤脱落,形态紊乱,上皮细胞排列紊乱,线粒体水肿,出现空泡,部分细胞胞浆中细胞器溶解甚至消失,杯状细胞数目增多。各试验组炎症因子表达量的变化与细菌浓度有关,IL-15、IL-8、TNF-α和IL-1β的表达量随细菌浓度的升高而升高,且随时间呈现先上升后下降的趋势。IL-10、IL-11和TGF-β_(2)的表达量与感染浓度呈负相关,其中IL-10和IL-11的基因表达量变化显著低于对照组,TGF-β_(2)的基因表达量变化不显著。【结论】1×10^(7) CFU/mL攻毒组在整个试验过程中未出现死亡,病理学观察显示肠道有较明显的病理损伤。因此,为构建接近临床条件的细菌性肠炎模型,选择攻毒剂量为200μL 1×10^(7) CFU/【Objective】This study aimed to establish a stable bacterial enteritis model of largemouth bass(Micropterus salmoides)infected by Aeromonas hydrophila,and to determine the concentration and bacte-rial infection time which leading to enteritis.【Method】150 healthy largemouth bass were randomly di-vided into 5 groups:the control group and 4 experimental groups(the infection concentrations of bacteria were 1×10^(8),1×10^(7),1×10^(6) and 1×10^(5) CFU/mL,respectively).The fish was infected by intraperitoneal in-jection.The effect of modeling in each experimental group was evaluated by means of clinical symptom-atology,necropsy lesions and scores,histological changes and scores,intestinal tissue ultrastructural changes and inflammatory factor gene expression.【Result】The experimental groups fish showed slow swimming and decreased feeding after the infection,of which the death was appeared in the 1×10^(8) CFU/mL group on the 2nd and 3rd day post-infection.After the autopsy,anal redness and swelling,protrusion,abdominal fin and abdominal skin bleeding,intestinal congestion and bleeding,intestinal fluid retention were showed in experiment groups.The gross pathological scores of each group were positively correlated with the bacterial infection concentration and negatively correlated with the post-infection time.Histologi-cal observation showed that the intestinal lamina propria was hyperemic,edematous,thickened,accom-panied by inflammatory cell infiltration,mucosal epithelial damage and shedding,cell degeneration,ne-crosis,hyperplasia,and the number of goblet cells significantly increased.The histological score in-creased with the increase of bacterial concentration,which showed a trend of first increasing and then de-creasing with the post-infection day,with the highest histological score on the 5th post-infection day.The ultra-structure morphological disorders in intestinal tissue were observed,which were positively cor-related with the infection concentration.The microvilli were observed to be damaged and

关 键 词：大口黑鲈 细菌性肠炎 模型 嗜水气单胞菌 

分 类 号：S943[农业科学—水产养殖]