免疫感受态小鼠感染卡氏肺孢子虫的研究

目的;研究成年感受态CB17小鼠对卡氏肺孢子虫（Pneumocystis carinii,Pc)的敏感性,探讨其在Pc传播中的作用。方法：使用免疫机能正常的健康成年CB17小鼠,使其中一部分小鼠与Pc( )-SCID小鼠接触1周,另一部分持续接触至被处时为止,分别在第3、5、6周检查肺内Pc包囊或PcDNA。观察病原体和Pc DNA出现和持续时间。结果：接触传染源的动物,不论是接触1周,还是持续接触至被处死,肺内均查到Pc包囊或PcDNA。其中,3周时,PCR法查到PcDNA,第5周时,PCR法和病原学染色法均查到Pc,第6周时,虫体减少到可检出阈值以下。结论：免疫感受态宿主可通过接触方式感染Pc,接触传染源1周即可被感染,感染状态可持续5周以上。期间,这种病原携带状态的小鼠在Pc传播中存在潜在的危险。此状态宿主在流行病学中的意义有待于进一步研究证明。

Immunocompetent healthy adult mice infected with Pneumocystis carinii by contagious transmission

Aim To study the sensitivity to Pneumocystis carinii (Pc) in immunocompetent adult CB17 mice and its role in transmitting Pneumocystis carinii Method Healthy adult CB17 mice were used and contacted with Pc (+) SCID mice Half of the mice were removed from contacting after one week and the rest remained in contacting for duration of the experiment The numbers of Pneumocystis carinii and Pc DNA were determined at 3,5,6 weeks after contacting Result In contacted mice,Pneumocystis carinii specific DNA were found by PCR at 3 weeks All of the contacted mice had microscopically detectable numbers of Pneumocystis carinii in their lungs as well as Pc DNA by PCR at 5 weeks By 6 weeks after the end of contacting,Pneumocystis carinii declined to undetectable numbers Conclusion The immunocompetent mice could get infected by Pneumocystis carinii when they were cohabited with Pneumocystis carinii positive mice Pneumocystis carinii persist in the lungs of immunocompetent adult for 5 weeks This could be able time for the "infected" mouse to infect other mice It should be researched in future that the ability of Pneumocystis carinii harboring immunocompetent mice to transmit Pneumocystis carinii to other mice