PCR鉴别诊断间日疟及恶性疟的研究

目的 :在同一反应体系中建立能鉴别诊断间日疟与恶性疟的 PCR检测方法。方法 :根据红内期疟原虫 SSUr RNA编码基因序列 ,设计合成 3个引物 ,采用聚合酶链反应技术 ,在同一反应体系中 ,间日疟原虫和恶性疟原虫分别预期被扩增出 34 1bp和 4 31bp的 DNA条带。结果 :间日疟原虫和恶性疟原虫模板在同一反应体系中分别被扩增出预期大小的 DNA片段 ,并经限制性酶切证实 ;杜氏利什曼原虫、弓形虫、健康人血及空白对照均无特异性扩增条带 ;以该检测体系至少可检出原虫血症为 2 .56× 10 ^-7间日疟原虫感染和 1.0 8× 10 ^-5恶性疟原虫感染 ;69份镜检阳性的间日疟和 2份恶性疟患者血样 PCR检测均为阳性 ,1例发热待查患者PCR诊断为间日疟 ,与镜检复查结果一致 ,所有疟疾阳性标本中未检出混合感染 ,2 0份健康人血 PCR均为阴性。结论 :该检测体系灵敏、特异 ,对于诊断间日疟和恶性疟以及鉴别间日疟原虫和恶性疟原虫混合感染具有一定的应用价值。

DIFFERENTIATION OF VIVAX MALARIA AND FALCIPARUM MALARIA BY POLYMERASE CHAIN REACTION

AIM:To establish a PCR- based method to detect and differentiate Plasmodium vivax (P.v) and Plasmodium falciparum(P.f) in blood samples in a single amplification reaction. METHODS: Three primers were designed according to the asexual stage plasmodial SSUr RNA gene and different sizes of PCR products were yield by PCR including a 341 bp product for P.v and a 431 bp product for P.f. RESULTS:The PCR- based method was successfully in dectecting P.v and P.f infection in a single PCR reaction, which was specific and sensitive enough to detect parasitemia level as low as 2.56×10^-7 for P.v and 1.08×10^-5 for P.f. 69 P.v infection and two P.f infection blood samples were all positive by the PCR and 20 normal blood samples were all negative. CONCLUSION: The PCR was specific and sensitive in the detection of P.v and P.f infections.