定量PCR对兔肺白念珠菌病诊断价值和标准的动物实验研究

Diagnostic value and standard of quantitative PCR in rabbits with pulmonary candidiasis albicance

目的:以病理结果为参照,探讨定量PCR(qPCR)对肺白念珠菌病的诊断价值和诊断标准。方法:利用气管接种法制作新西兰兔肺白念珠菌病动物模型。随机将兔分为实验组、对照组,各18只,并随机排序。实验组气管内注入0.2 ml含1×108个白色念珠菌的菌液,对照组注射等量生理盐水。按接种后天数依次处死动物,取肺组织做病理切片,取支气管冲洗液(BLF)进行白念珠菌定量PCR检测,观察定量PCR检测与病理结果的一致性。结果:以500/ml菌数为界值时,qPCR技术与病理诊断一致性检验示:敏感性、特异性、准确性、阳性似然比、阴性似然比分别为71.9%、92.5%、83.3%、9.59、0.3(P均<0.001)。结论:qPCR技术与病理诊断有良好的一致性,诊断界值以500/ml较合理。

Objective： To explore the diagnostic value and standard of quantitative PCR（qPCR） in pulmonary candidiasis albicance in rabbits referring to pathology. Methods： New Zealand white rabbit models of pulmonary candidiasis were developed. Thirty-six rabbits were randomly divided into two groups： the experimental group and the control group. 18 rabbits were enrolled in each group and they were randomly ranked. Rabbits in the experimental group were formed by per cutem intratracheal injection of 0.2 ml bacterium fluid containing 1 × 10s candida albicans（ C. albicans）. The same volume of normal saline was given in the control group. Rabbits were killed based on a sequence day by day and the pathology of the lungs was observed. Bronchi lavage fluid （BLF） was collected to determine C. albicans by qPCR. Result： If 500 C. albicans/ml was a critical value, the qPCR and pathological results had a significant consistence： sensitivity, specificity, accuracy, positive likelihood ratio and negative likelihood ratio respectively were 71.9%,92.5 %, 83.3 %, 9.59 and 0.3 （ P 〈 0.001 ）. Conclusion： The qPCR is quite consistent with pathology in diagnosis of the disease. The critical value is 500/ml.