铜绿假单胞菌家兔肺部感染模型的建立与评价

Replication and Evaluation of A Model of Pulmonary Infection of Pseudomonas aeruginasa in Rabbit

目的:建立铜绿假单胞菌(PA,又名绿脓杆菌)肺部感染动物模型,并从病理学及细菌学、影像学等方面进行评价,研究铜绿假单胞菌对肺组织的致病作用。方法:24只健康清洁级新西兰大白兔随机分成2组,实验组采用经皮气管穿刺法,隔日注入铜绿假单胞菌反复感染家兔,对照组施以生理盐水。接种后隔日一次行胸部CT扫描。比较二组家兔的体温、血象及肺组织匀浆菌落计数;观察病理组织改变及胸部CT影像学变化。结果:注菌组家兔白细胞总数显著升高,肺组织匀浆菌落计数显著高于对照组。CT表现为双侧多发斑片状模糊影,部分可见实变及脓肿灶。大体标本可见家兔肺部结节、脓肿及出血灶,病理学镜下观察发现注菌组家兔肺组织内多个脓肿灶形成,大量中性粒细胞浸润,肺泡腔内大量渗出,部分出血,肺泡壁充血及肺水肿。随着注菌次数增多及时间推移,逐渐出现如肺泡间隔增厚、肉芽肿形成、实变等慢性肺部炎症的病理表现。结论:使用经皮气道穿刺法接种铜绿假单胞菌至新西兰兔肺部,可成功建立兔铜绿假单胞菌肺部感染模型。

Objective： To establish an animal model of lung infection of Pseudomonas aeruginosa （PA） and evaluate its pathology and bacteriology, imaging and other aspects, for investigating the effect of Psendomonas aeruginosa on lung infection of PA. Methods： 24 healthy, clean New Zealand rabbits were randomly divided into two groups： experiment group were treated with injection of Pseudomonas aeruginosa suspension by means of percutaneous tracheal puncture every other day; rabbits in control group were subjected to sterile saline. Chest CT scan was performed after inoculation and the bacteria number in the lung was determined. Pathological and radiological changes were compared between these two groups. Results： The number of white blood cells （WBC） and bacteria detected from experiment group were significantly higher than that in control group. CT showed bilateral multiple patchy opacities, consolidation and abscess, et al. Nodules, abscesses, and hemorrhage could be seen on lung specimen while related findings observed under optical microscope. In the early stage, multiple focal abscess, infiltration of neutrophil, exudation in alveolar, alveolar wall＇s congestion and pulmo- nary edema formed. Then, chronic inflammatory of lung such as thickening of alveolar septal, granuloma, consolidation or atelectasis were the major pathological changes. Conclusion： The rabbit model of lung infection can be reproduced by percutaneous puncturing and in- oculating Pseudomonas aeruginosa to airway.