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

Objective To explore a new method to establish the SD rat model of Pseudomonas aeruginosa (PA) pneumonia. MethodsA 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 experiments, rats were sacrificed and the left lung was taken for pathological examination, and the right lung was used to make the colony count. ResultsCompared with the control, the model group showed significantly more serious clinical manifestation, 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. ConclusionsA SD rat model of PA pneumonia is successfully established which is simple and convenient with a low mortality.