应用二步PCR检测法筛选及鉴别诊断脑膜炎的实验研究

An experimental study on diagnosing and distinguishing meningitis using two step PCR reaction

目的 寻找快速筛选及鉴别细菌性和非细菌性脑膜炎的方法。方法 二步 PCR法 ,第一步检测真细菌 ,所用引物 U3- r U8,区分细菌性和非细菌性 ;第二步检测目的菌 ,引物为 r U 8- NM,r U8- HI,r U8- STIEP,TB1-TB2 ,区分化脓性和结核性。应用此法检测临床脑膜炎 CSF标本总共 113例 ,对照组 6 6例。结果 第一步真细菌引物特异性试验阳性模板均为阳性结果 ,第一步各菌引物对应目的菌阳性 ,其余阴性。PCR灵敏度各菌最低检测浓度为 2 0 CFU /m l。临床检测 1周内特异性为 10 0 % ,敏感性为 93.75 % ,准确性为 98.32 %。 1周后临床检测特异性为10 0 % ,敏感性为 86 .5 7% ;准确性为 94.6 7%。结论 1周内早期诊断敏感性和准确性更高。联合检测法为脑膜炎早期快速筛选鉴别的有效方法。

Objective: To find a quick method to diagnose and distinguish meningitis. Methods Two step PCR was used in this study. Bacteria and non bacteria were distinguished for fungus by primer U3 rU8 in first step,suppurate and tuberculosis distinguished for objective bacteria by primer rU8 NM,rU8 HI,rU8 STIEP,TB 1 TB 2 in second step. Experimental CSF (113 cases) and control CSF (66 cases)were included in this study. Results Specific testing templates for fungus primer were all positive in first step,the bacteria conresponding to objective bacterium were positive too,and the othes were negitive. For PCR sensitivity,the lowest density for bactria examination was 20 CFU/ml,for clinical examination in one week,the specificify was 100%,the susceptibility 93.8%,accuracy 98.3%. However,after one week,the specificity was 100%,the susceptibility 86.6%,accuracy 94.7%. Conclusion Two step PCR was more sensible and accurate in the first week. The combined method was a good way to diagnose and distinguish meningitis at early stage.