弗氏柠檬酸杆菌的鉴定及其药敏试验  

Identification and Drug Sensitivity Test of Citrobacter freundii

作　　者：许国洋 付文贵[1,2] 付利芝 闫志强[1,2] 高广亮 邓娟[3] 戴玉娇 庞丽霞[3] 翟少钦 XU Guo-yang;FU Wen-gui;FU Li-zhi;YAN Zhi-qiang;GAO Guang-liang;DENG Juan;DAI Yu-jiao;PANG Li-xia;ZHAI Shao-qin(Chongqing Academy of Animal Sciences,Chongqing 402460,China;Chongqing Veterinary Biological Products Engineering Technology Research Center,Chongqing 402460,China;Chongqing Tongnan District Agriculture and Rural Committee,Chongqing 402660,China)

机构地区：[1]重庆市畜牧科学院,重庆402460 [2]重庆市兽用生物制品工程技术研究中心,重庆402460 [3]重庆市潼南区农业农村委,重庆402660

出　　处：《动物医学进展》2024年第4期92-96,共5页Progress In Veterinary Medicine

基　　金：国家生猪技术创新中心奖补专项研发项目(21604);国家动物疫病长期性观测监测项目(ZX06S2302)。

摘　　要：为进一步明确分离自仔猪腹泻肛拭子样本的弗氏柠檬酸杆菌病原特性、耐药情况及其对小鼠的致病性,试验通过5%兔鲜血TSA培养基培养、生化指标测定、敏感药物和耐药基因筛选对其进行鉴定,并用其腹腔注射攻毒小白鼠,分析其对小鼠的致病性。结果显示,分离到的弗氏柠檬酸杆菌在血平板上生长时导致溶血现象。生化试验中,硝酸盐还原、山梨醇和葡萄糖发酵等9个检测指标为阳性;且该菌对氧氟沙星、诺氧沙星、万古霉素、青霉素和链霉素耐药,并携带aacA-aphD、ileS和vanA3种耐药基因。该菌对小鼠的致死率为60%,剖检发现小鼠肝脏、肺脏、肠道、肾脏和脾脏组织发生不同程度病理变化,其中,小鼠肝脏和肺脏组织的出血症状最为明显;组织病理学观察发现,肝脏组织可见多量中央静脉淤血,肝窦内可见淤血;肺脏组织可见大量血管淤血,大面积肺泡壁间质淤血;肠绒毛黏膜上皮与固有层轻度分离。试验结果可为弗氏柠檬酸杆菌致病机理的进一步研究提供参考,也可为仔猪潜在细菌性疫病防治提供了数据支撑。In order to further clarify the pathogenic characteristics,drug resistance,and pathogenicity of Citrobacter freundii isolated from anal swab samples of piglets with diarrhea,5%rabbit fresh blood TSA medium culture,biochemical index determination,sensitive drug and resistance gene screening were used to identify this bacterium,and it was intraperitoneally injected into mice to analyze its pathogenicity to mice.The results showed that the isolated Citrobacter freundii exhibited hemolysis in the blood plate.Nine biochemical indicators,including nitrate reduction,sorbitol,and glucose,were positive.The strain was resistant to ofloxacin,norfloxacin,vancomycin,penicillin and streptomycin,and carried aacA aphD,ileS and vanA3 resistance genes.Its lethality rate in mice was 60%.Upon autopsy,it was found that liver and lung lesions were the most obvious.Pathological observations revealed varying degrees of pathological lesions in the liver,lungs,intestines,kidneys,and spleen of mice,with the most obvious hemorrhage in the liver and lungs of mice.Histopathology observation showed that there were many central venous congestion in liver tissue and congestion in hepatic sinuses.A large amount of blood vessels and interstitial congestion in the alveolar wall could be seen in the lung tissue.The mucosal epithelia of intestinal villi were slightly separated from the lamina propria.This study provides a reference for further research on the pathogenic mechanism of Citrobacter freundii,and also provides data support for the prevention and control of potential bacterial diseases in piglets.

关 键 词：猪 弗氏柠檬酸杆菌 分离鉴定 耐药基因 致病性 

分 类 号：S852.612[农业科学—基础兽医学] S858.28[农业科学—兽医学]