肺炎克雷伯菌致大鼠重症肺炎模型的建立

Rat model of Klebsiella pneumoniae-induced severe pneumonia

目的探索大鼠细菌性重症肺炎的诊断标准及病理生理特点。方法SpragueDawleg大鼠随机分为模型组、观察组和对照组,每组分为3小组,前两组每小组8只,对照组每小组4只。其中,模型组和观察组分别接种相同浓度不同剂量的肺炎克雷伯菌菌液,对照组接种与观察组剂量相同的生理盐水。分别与接种后的第2、4、6天分批处死动物,动态观察动物的血液动力学、血气分析、外周血象、肺泡灌洗液中白细胞和中性粒细胞计数及病理改变。结果接种高剂量菌液的模型组于接种后第5天出现明显血液动力学改变,于第4天出现血气分析的改变。模型组外周血象、肺泡灌洗液的白细胞和中性粒细胞计数及病理改变在各处死时间段较接种低剂量的观察组明显加重。同时,模型组和观察组随着接种时间的延长,血液动力学、血气分析、外周血象、肺泡灌洗液的白细胞和中性粒细胞计数及病理改变逐渐加重。对照组的各项检测指标于接种前后无明显变化。结论随着接种一定浓度菌液剂量的增加,致使大鼠肺炎明显加重,出现类似人群细菌性重症肺炎的改变。

Objective To explore the diagnostic criteria and physiopathological features of severe bacterial pneumonia in rats. Methods A total of 60 Sprague Dawleg rats were randomly divided into 3 groups, namely the model group （n=24）, observation group （n=24）, and control group （n=12）. The rats in the former two groups were intratracheally instilled with KlebsieUa pneumonioe suspension at different doses, while those in the control group received intratracheal administration of 1 ml saline. On the 2nd, 4th, and 6th days after intratracheal instillation, 1/3 of the rats in each group were killed to determine the hemodynamics, arterial blood gas （ABG）, peripheral hemogram, leukocytes and neutrophils in the bronchoalveolar lavage fluid （BALF）, followed by pathological examination of the lung. Results Obvious hemodynamic changes occurred in the rats of the model group on the 5th day and ABG changes appeared on the 4th day. The changes in peripheral hemogram, leukocytes and neutrophils in the BALF, and lung pathology of the rats in the model group were more obvious than those in the observation group on each time point. As the time prolonged, the changes in the hemodynamics, ABG, peripheral hemogram, leukocytes and neutrophils in the BALF and pathology of the lung exacerbated in the model group and observation group, but all these indices in the control group remain unchanged after bacterial inoculation. Conclusion The severity of pneumonia in rats increases with the dose increment of the administered Klebsiella p neumoniae suspension, which mimics the pathological changes in severe bacterial pneumonia in human.