临床分离菌株ICR小鼠血流感染模型的建立  

Establishment of the ICR mouse models of bloodstream infections induced by clinical strains

作　　者：谢尹晶[1,2] 段晋燕[2] 张洪瑞[1,2] 王娜[1,2] 刘一凡[2] 吴小利[1,2] 唐红卫[2] 王成彬[1,2] 

机构地区：[1]温州医科大学检验医学院生命科学学院临床检验诊断学,浙江温州325035 [2]解放军总医院临床检验科,北京100853

出　　处：《中华医院感染学杂志》2014年第3期521-523,共3页Chinese Journal of Nosocomiology

基　　金：国家重大科学仪器专项基金资助项目(2012YQ18011708)

摘　　要：目的建立革兰阴性菌和革兰阳性菌ICR小鼠血流感染模型,为寻找能在疾病早期鉴别不同病原菌所致血流感染的炎症指标等研究提供有效可靠的实验模型。方法收集临床分离的大肠埃希菌和金黄色葡萄球菌菌株,将不同浓度的细菌悬液通过尾静脉注射入ICR小鼠体内,按Reed-Muench方法计算半数致死量LD50,并根据1/2LD50浓度的菌液建立小鼠感染模型,通过进行小鼠血液白细胞(WBC)计数和C-反应蛋白(CRP)检测,肝和肺的病理改变观察,验证造模结果。结果大肠埃希菌的LD50为1.77×109 CFU/ml,金黄色葡萄球菌为4.21×108 CFU/ml;运用1/2LD50的菌液浓度感染后6h,大肠埃希菌和金黄色葡萄球菌感染小鼠血浆CRP即明显升高,分别为(263.3±28.7)、(499.1±32.6)ng/ml;感染后12h,各组小鼠的WBC明显升高;感染12h即可观察到肝和肺的炎症细胞浸润,至感染48h肺泡腔可见大量渗出液,肝脏可见明显坏死灶。结论成功建立小鼠血流感染模型,为血流感染的早期诊断和不同病原菌感染的鉴别诊断等研究提供了可靠的动物模型。OBJECTIVE To establish the ICR mouse models of gram-negative and gram-positive bloodstream infections so as to provide effective and reliable experimental models for the study of inflammatory mediators that can differentiate diagnosis of gram-negative and gram-positive infections earlier. METHODS ICR mice were challenged with different dose of clinical strains of Escherichia coli and Staphylococcus aureus by intravenous tail injection. The median lethal dose （LD50） was calculated according to the Reed-Muench method, and the model was established by injecting according to 1/2 LD50 dose. The models were evaluated by white blood cells （WBC）, C-reactive protein （CRP） and pathological examination of liver and lung. RESULTS The LD50 of E. coli and S. aureus to ICR mice were 1.77× 10^9 CFU/ml and 4.21× 10^8 CFU/ml, respectively. By injecting the dose of 1/2 LD50, the mice had evident CRP increase at six hours after E. coli and S. aureus infections, （263.3±28. 7）, （499.1 ± 32.6）ng/ml respectively, and had significant WBC increase （12 hours after infection）, and pathological alterations in liver and lung （12 hours after infection）. Extensive exudates were found in alveolar space after 48 h of infection, and focal necrosis can be seen obviously in the liver. CONCLUSIONS The ICR mouse models of blood- stream infections induced by clinical strains are successfully established and can provide reliable model for the relevant research such as early diagnosis and differential diagnosis of bloodstream infection.

关 键 词：血流感染 动物模型 

分 类 号：R378[医药卫生—病原生物学]