摘要
为了系统评估海藻糖比伯斯坦杆菌(Bibersteinia trehalosi,B.trehalosi)对实验动物小鼠和靶动物绵羊的致病特征,本研究将分离自因肺炎死亡绵羊的B.trehalosi GD01菌株以不同剂量进行接种小鼠与绵羊,并确定动物接种后的临床表现、病理变化与病原载量等关键指标。结果表明:在小鼠的试验中,通过腹腔接种该菌后,表现出剂量依赖性致死效应,随着剂量的增加,死亡率逐渐上升,并伴随着严重的肺部病变和细菌载量的显著升高。在绵羊的试验中,将该菌以不同剂量经气管内接种绵羊后,可诱发急性发热、咳嗽、流涕和食欲减退等症状,且随着接种剂量的增加,症状表现逐渐加重。剖检结果显示,绵羊肺脏呈现不同程度的淤血、实变、纤维素渗出、胸肺黏连及化脓等大体病变,病理变化呈现典型的纤维素性肺炎与胸膜肺炎,病变程度与感染剂量呈正相关;组织病理学观察可见纤维细胞增生和炎症性细胞浸润等病理变化,且免疫组化显示肺泡内病原明显聚集。qPCR检测绵羊感染后能够通过鼻腔持续排菌,且肺脏中检测到高细菌载量,表明该菌能够在绵羊肺脏中成功定植并引发疾病。综上所述,本研究对B.trehalosi感染小鼠和绵羊后的临床症状、病理变化与病原载量等方面进行了详细表征,确定了B.trehalosi能够以剂量依赖性的方式诱发小鼠和绵羊的致病反应,这些结果将为进一步了解该菌致病机制、建立动物感染模型、以及防控技术的开发提供了重要实验依据。
To thoroughly evaluate the pathogenic characteristics of Bibersteinia trehalosi(B.trehalosi)in experimental animals(mice)and target animals(sheep),this study will inoculate mice and sheep with varying doses of the B.trehalosi GD01 strain,which was isolated from a sheep that died of pneumonia.Key indicators,including clinical symptoms,pathological changes,and pathogen load post-inoculation,will be assessed to provide a detailed understanding of the virulence of the strain.In the mouse experiment,intraperitoneal inoculation of the bacteria resulted in a dose-dependent lethal effect.As the dose increased,the mortality rate gradually rose,accompanied by severe pulmonary lesions and a significant increase in bacterial load.In the sheep experiment,intratracheal inoculation of the bacterium at different doses induced acute fever,coughing,nasal discharge,and anorexia,with more severe symptoms at higher doses.Necropsy results showed varying degrees of congestion,consolidation,fibrinous exudation,pleuropulmonary adhesions,and purulence in the lungs,with pathological changes typical of fibrinous pneumonia and pleuropneumonia.The severity of these changes was positively correlated with the infection dose.Histopathological observations revealed fibroblast proliferation and inflammatory cell infiltration,and immunohistochemistry showed significant pathogen aggregation within the alveoli.qPCR analysis showed that sheep continued to shed bacteria through the nasal cavity after infection,with high viral loads detected in the lungs,indicating that the bacterium successfully colonized the sheep’s lungs and caused disease.In conclusion,this study characterized the clinical symptoms,pathological changes,and pathogen load after B.trehalosi infection in mice and sheep,confirming that B.trehalosi induces a dose-dependent pathogenic response in both species.These findings provide important experimental data for further understanding the pathogenic mechanisms of this bacterium,establishing animal infection models,and developing prevention and control strategies.
作者
相浩雨
王晶
贾琦
杨鸣发
常继涛
王芳
姜志刚
尹鑫
XIANG Haoyu;WANG Jing;JIA Qi;YANG Mingfa;CHANG Jitao;WANG Fang;JIANG Zhigang;YIN Xin(College of Animal Science and Technology,Ningxia University,Yinchuan 750021,China;State Key Laboratory for Animal Disease Control and Prevention,Harbin Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Harbin 150069,China)
出处
《畜牧兽医学报》
北大核心
2025年第12期6450-6457,共8页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
基金
国家重点研发计划项目(2022YFF0710500)。
关键词
海藻糖比伯斯坦杆菌
致病性
临床症状
病理变化
细菌载量
Bibersteinia trehalosi
pathogenicity
clinical symptoms
pathological changes
bacterial load
