There is a critical need for better malaria rapid diagnostic tests to discriminate Plasmodium falciparum and Plasmodium vivax infection given the recent observation of HRP2 deletions in P. falciparum parasites. We previously identified a DNA aptamer, 2008s, that targets P. falciparum lactate dehydrogenase (PfLDH) and developed a sensitive aptamer-tethered enzyme capture (APTEC) assay. Here, we characterise two different LDH-binding DNA aptamers in their species-specific activities, then integrate within biochemical diagnostic assays and test in clinical samples. An enzyme-linked oligonucleotide assay demonstrated that aptamer pL1 bound with high affinity to both PfLDH and P. vivax lactate dehydrogenase (PvLDH), whereas aptamer 2008s was specific to PfLDH. An aptamer-tethered enzyme capture (APTEC) assay confirmed the specificity of 2008s in binding and capturing the enzyme activity of PfLDH which could be observed colorimetrically. In malaria patient samples, the 2008s APTEC assay was specific for P. falciparum blood samples and could discriminate against P. vivax blood samples. An aptamer for specific detection of falciparum malaria holds promise as a new strategy for species-specific malaria diagnosis rather than the conventional HRP2 immuno-assay.

鉴于最近在恶性疟原虫中观察到HRP2缺失，迫切需要更好的疟疾快速诊断检测方法，以区分恶性疟原虫和间质疟原虫感染。我们先前确定了针对恶性疟原虫乳酸脱氢酶（PfLDH）的DNA适体，2008年代，并开发了一种敏感的适体拴系酶捕获（APTEC）分析方法。在这里，我们表征两种不同的LDH结合DNA适体的物种特异性活性，然后整合到生化诊断测定中并在临床样品中进行测试。酶联寡核苷酸测定表明适体pL1与PfLDH和间日疟原虫都具有高亲和力乳酸脱氢酶（PvLDH），而适体2008s是PfLDH特有的。适体束缚的酶捕获（APTEC）分析证实了2008年代在结合和捕获PfLDH的酶活性方面的特异性，这可以通过比色法观察到。在疟疾患者样本中，2008s APTEC分析法对恶性疟原虫血样具有特异性，可以区分间日疟原虫血样。特异性检测恶性疟疾的适体有望成为一种针对物种特异性疟疾诊断的新策略，而不是常规的HRP2免疫测定。