Assessment of the drug susceptibility of Plasmodium falciparum clinical isolates from Africa by using a Plasmodium lactate dehydrogenase immunodetection assay and an inhibitory maximum effect model for precise measurement of the 50-percent inhibitory concentration
Assessment of the drug susceptibility of Plasmodium falciparum clinical isolates from Africa by using a Plasmodium lactate dehydrogenase immunodetection assay and an inhibitory maximum effect model for precise measurement of the 50-percent inhibitory concentration
复制标题
DOI：
10.1128/aac.00367-06
复制
发表时间：
2006-10-01
影响因子：
4.9
通讯作者：
Le Bras, Jacques
中科院分区：
文献类型：
--
作者：
Kaddouri, Halima;Nakache, Serge;Le Bras, Jacques
在非洲，引起疟疾的恶性疟原虫抗药性的扩大需要实施新的联合治疗战略。药物敏感性表型需要精确的测量。直到最近，裂殖体成熟和体外同位素分析是唯一可用的方法，但它们的使用受到技术限制的限制。这解释了人们对替代方法的发展重新产生了兴趣，例如疟原虫乳酸脱氢酶(PLDH)免疫检测方法。我们评估了一种商业控制的pLDH酶联免疫吸附试验(ELISA；ELISA-疟疾抗原试验；DiaMed AG，Cressier S/Morat，瑞士)，以在标准的体外试验中评估药物敏感性，使用相当基本的实验室设备来研究疟疾寄生虫对主要抗疟疾药物的体外耐药性。对2003~2004年收集的5个恶性疟原虫克隆株和121个非洲临床分离株进行了pLDH酶联免疫吸附试验和[8(-3)H]次黄嘌呤同位素测定，并以4种抗疟药为参照物。采用最大效应模型进行非线性回归，估算其半数抑制浓度(IC50)及其可信区间。两种方法具有相似的重复性，但pLDH-ELISA法的灵敏度更高。两种方法的相关性高(r=0.98)，表型一致性高(K=0.88)，可通过测定IC(50)S进行比较。最近收集的恶性疟原虫非洲分离株对氯喹和阿莫地喹活性代谢物的耐药性或敏感性分别为6 2%和11 5%。没有检测到对鲁米芬或青蒿素活性代谢物的敏感性降低。这种简便、高灵敏度的pLDH免疫检测方法的建立，将为疟疾原虫的药敏试验提供一种更简便的方法。
The extension of drug resistance among malaria-causing Plasmodium falciparum parasites in Africa necessitates implementation of new combined therapeutic strategies. Drug susceptibility phenotyping requires precise measurements. Until recently, schizont maturation and isotopic in vitro assays were the only methods available, but their use was limited by technical constraints. This explains the revived interest in the development of replacement methods, such as the Plasmodium lactate dehydrogenase (pLDH) immunodetection assay. We evaluated a commercially controlled pLDH enzyme-linked immunosorbent assay (ELISA; the ELISA-Malaria antigen test; DiaMed AG, Cressier s/Morat, Switzerland) to assess drug susceptibility in a standard in vitro assay using fairly basic laboratory equipment to study the in vitro resistance of malaria parasites to major antimalarials. Five Plasmodium falciparum clones and 121 clinical African isolates collected during 2003 and 2004 were studied by the pLDH ELISA and the [8(-3)H]hypoxanthine isotopic assay as a reference with four antimalarials. Nonlinear regression with a maximum effect model was used to estimate the 50% inhibitory concentration (IC50) and its confidence intervals. The two methods were observed to have similar reproducibilities, but the pLDH ELISA demonstrated a higher sensitivity. The high correlation (r = 0.98) and the high phenotypic agreement (K = 0.88) between the two methods allowed comparison by determination of the IC(50)s. Recently collected Plasmodium falciparum African isolates were tested by pLDH ELISA and showed drug resistance or decreased susceptibilities of 62% to chloroquine and 11.5% to the active metabolite of amodiaquine. No decreased susceptibility to lumefantrine or the active metabolite of artemisinin was detected. The availability of this simple and highly sensitive pLDH immunodetection assay will provide an easier method for drug susceptibility testing of malaria parasites.