探索建立SD大鼠铜绿假单胞菌肺炎模型的新方法

A new method to establish the SD rat model of Pseudomonas aeruginosa pneumonia

目的研究一种建立SD大鼠铜绿假单胞菌肺炎模型的新方法。方法清洁级SD大鼠30只，随机分为模型组（n=20）和对照组（n=10），所有实验动物用10％水合氯醛腹腔注射麻醉，模型组经口气管插管接种0．4ml铜绿假单胞菌（PA）混悬液，对照组予以同等方法气管内注入0．4ml灭菌生理盐水。观察2组大鼠的临床表现、体温、白细胞计数（WBC）、中性粒细胞计数（NEUT）、中性粒细胞百分数（NEUTr％）、C反应蛋白（CRP）的变化，实验24h后处死大鼠，剖胸取左肺做病理学检查，右肺做肺组织匀浆菌落计数。结果与对照组比较，模型组临床表现、肺组织病理改变明显加重，体温变化更明显，肺组织匀浆菌落计数平均为6．8×10^5cfu／g。模型组注菌前后WBC、NEUT、NEUTr％、CRP差异有统计学意义（P〈0．05）。对照组各项观察指标在注菌前后无明显变化（P〉0．05），肺组织匀浆未培养出铜绿假单胞菌标准株。结论应用该方法成功建立SD大鼠铜绿假单胞菌肺炎模型，该方法简单、便捷、对动物损伤小、病死率低。

Objective To explore a new method to establish the SD rat model of Pseudomonas aeruginosa （PA） pneumonia. Methods A total of 30 SD rats were randomly divided into a model group （n = 20） and a control group （ n = 10）. All animal were intraperitoneally injected with 10% chloral hydrate. The model group was inoculated with 0.4 ml of PA suspension through orotracheal intubation, while the control group was given 0.4 ml sterile saline through the same method. Then, the changes of clinical manifestation, body temperature, white blood cell count （WBC）, neutrophil count （NEUT）, neutrophil percentage （NEUTr%） and C -reactive protein （CRP） were observed. One day after experi- ments, rats were sacrificed and the left lung was taken for pathological examination, and the fight lung was used to make the colony count. Results Compared with the control, the model group showed significantly more serious clinical mani- festation, more obvious temperature changes and pathological changes of the lung, with 6.8 × 105 cfu/g of colony count of lung homogenate on the average. Significant differences were found in WBC, NEUT, NEUTr%, and CRP in the model group before and after injection （P 〈 0.05 ）. No significant difference was found as to the indexes above in the control group before and after experiment （ P 〉 0.05 ）. No standard PA strain was detected in the lung homogenate. Conclusions A SD rat model of PA pneumonia is successfully established which is simple and convenient with a low mortality.