Protease as the pathogenic factor of Pseudomonas cepacia pneumonia

本研究的目的是研究蛋白酶的作用，作为一个致病性决定因素的洋葱疫霉。在本研究中使用洋葱假单胞菌的临床分离菌株（KF-1），其来源于洋葱假单胞菌肺炎患者，并产生显著量的蛋白酶。作为比较，还使用了KFT 1007菌株，该菌株通过插入单个转座子基因由KF-1产生，并且失去了释放蛋白酶的能力。免疫抑制小鼠经阴道接种2 × 10^8集落形成单位的洋葱伯克霍尔德菌进行攻击，并记录存活率。产蛋白酶菌株与不产蛋白酶菌株的存活率存在明显差异。总之，我们的研究表明，蛋白酶起着重要的作用，洋葱疫霉的发病机制。

The present study was designed to examine the role of protease as a pathogenic determinant of P.cepacia. Clinically isolated strain of P.cepacia (KF-1), which was derived from a patient with P.cepacia pneumonia, and produced a significant amount of protease was used in this study. In comparison, the strain KFT1007, which was produced from KF-1 by the insertion of a single transposont gene, and lost the ability to release protease was also used. Immunosuppressed mice were challenged by intratracheal inoculation of 2*10^8 colony-forming units of P cepacia, and the survival rates were recorded. Between the strains which could produce protease and could not produce protease, there was an obvious difference in survival rates. In conclusion, our study suggests that protease plays an important role in the pathogenesis of P.cepacia.