老龄家兔慢性铜绿假单胞菌肺部感染的实验研究

An experimental model of chronic lung infection caused by pseudomonas aeruginosa in aged rabbits

目的:建立慢性铜绿假单胞菌(PA)肺部感染动物模型,研究铜绿假单胞菌对肺组织的致病作用。方法:本实验用生理盐水作对照,用喷雾法反复吸入感染家兔。比较二组家兔的体温、血象及支气管肺泡灌洗液(BALF)细菌计数;观察肺组织的病理改变。结果:吸菌组家兔白细胞总数显著升高,BALF细菌培养菌落计数显著高于对照组。病理学观察发现吸菌组家兔肺泡腔内大量出血、渗出,肺组织内多个小脓肿形成,中性粒细胞及多核巨细胞浸润。随着吸菌时间延长,逐渐出现慢性肺部病理改变。结论:使用老龄家兔反复吸入黏液型PA,可以建立PA菌慢性肺部感染家兔模型。

Objective： To study the pathogenic role of pseudomonas aernginosa （PA） in the pulmonary infection in aged patients.Methods.. An experimental model of chronic lung infection caused by PA bad been established in aged rabbits. Theses animals were divided into two groups, i.e. group A and group B. Group A inhaled saline suspension as the control and group B were challenged by PA suspension three times each week for four weeks. The body temperature and peripheral white blood cells（WBC） of these animals were measured, the bacteria in their hronchoalveolar lavage fluid（BALF） were incubated and the bacterial colonies were counted at the 3rd day, 15th, 30th and 60th day. At the same time, the pathological changes of the lung tissues were observed under microscopee. Results：Compared with group A, the temperature and peripheral WBC and bacterial colonies in BALF were higher significantly in group B. In group B, severe hemorrhage and exudation, polymorphonuclears and macropbages infiltration were found, and many small abscesses could he seen under light microscope. Along with PA challenge continuing, the chronic lung pathological changes appeared gradually.Conclusion. The chronic lung infection model can be established by inhalation with PA suspension repeatedly in aged rabbits.