Andrade L E, Cardona L E, Vergara C
Departamento de Microbiología, Fac. de Salud, Universidad del Valle, Cali, Colombia.
Arch Invest Med (Mex). 1991 Apr-Jun;22(2):181-7.
Probes pRepHind, Rep20, p242B1-1, pPF-14, clone 26 and 34 were compared for their applicability to detect P. falciparum in field conditions. Ninety four clinical samples from patients living in the malaria endemic area of Tumaco (Pacific Coast) plus 88 from Villavicencio (Eastern Plains) were tested in "dotblot" hybridization experiments. Probes Rep20, p242B1-1, pRepHind and pPF-14 detected up to 17 pg of purified P. falciparum DNA, while clone 26 and clone 34 detected up to 425 pg DNA. Probes pPF-14, P242B1-1, pRepHind and Rep 20 exhibited comparable detection levels of parasites in infected blood samples. Sensitivity declined from 69-94% in subjects with parasitemias higher than 10.000 par./ul to 15-42% in subjects with parasitemias lower than 100 par./ul. pPF-14 and p24B1-1 showed the highest sensitivity, while clone 26 and 34 presented significantly lower sensitivities. All probes were shown to be highly specific. Detection levels are dependent on specimen treatment. Treatment consisting of serum removal, Triton X-100 lysis, Proteinase K digestion, Phenol and Chloroform extractions followed by Ethanol precipitation yielded 100% sensitivity for specimens with parasite density higher than 1,000 par./l.
对探针pRepHind、Rep20、p242B1-1、pPF-14、克隆26和克隆34在现场条件下检测恶性疟原虫的适用性进行了比较。对来自图马科（太平洋沿岸）疟疾流行地区患者的94份临床样本以及来自比亚维森西奥（东部平原）的88份样本进行了“斑点印迹”杂交实验。探针Rep20、p242B1-1、pRepHind和pPF-14能检测到高达17 pg的纯化恶性疟原虫DNA，而克隆26和克隆34能检测到高达425 pg的DNA。探针pPF-14、P242B1-1、pRepHind和Rep 20在感染血样中对疟原虫的检测水平相当。寄生虫血症高于10,000个/微升的受试者的灵敏度从69%-94%下降到寄生虫血症低于100个/微升的受试者的15%-42%。pPF-14和p24B1-1的灵敏度最高，而克隆26和34的灵敏度明显较低。所有探针均显示具有高度特异性。检测水平取决于样本处理。包括去除血清、用Triton X-100裂解、蛋白酶K消化、苯酚和氯仿萃取，然后乙醇沉淀的处理方法对寄生虫密度高于1,000个/升的样本产生了100%的灵敏度。
