Laboratoire de Bacterio-Virologie, Hopital Aristide Le Dantec, 30 Avenue Pasteur, Dakar, Senegal.
Parasitol Res. 2012 Oct;111(4):1541-6. doi: 10.1007/s00436-012-2994-7. Epub 2012 Jun 17.
The goal of the present study was to assess the evolution of the in vitro chloroquine resistance and also the prevalence of pfcrt T76 and pfmdr1 Y86 mutations in Pikine from 2000 while chloroquine (CQ) was the first-line treatment of malaria to 2009 when artemisinin-based combination therapies (ACTs) are in use. We genotyped pfcrt K76T and pfmdr1 N86Y polymorphisms by PCR-RFLP and assessed in vitro CQ susceptibility by double-site enzyme-linked pLDH immunodetection (DELI) assay in Plasmodium falciparum isolates collected in Pikine, Senegal. The proportions of the pfcrt T76 allele in the light of the three different treatment policies were 72.4 % before CQ withdrawal (2000 to 2003), 47.2% while amodiaquine plus Fansidar was the first-line treatment (2004 to 2005), and 59.5 % since the ACT use was implemented (2006 to 2009). The prevalence of pfcrt T76 decreased significantly after CQ was stopped [X (2) = 6.54, P = 0.01 (2000-2003 versus 2004-2005)] and then slightly since ACTs have been implemented [X(2) = 1.12, P = 0.28 (2000-2003 versus 2006-2009)]. There were no significant differences on the prevalence of pfmdr1 Y86 throughout the three treatment policies. The DELI assay was carried out episodically in 2000 (n = 36), 2001 (n = 47), and 2009 (n = 37). The mean IC(50)s of the isolates to CQ in 2000 versus 2009 and 2001 versus 2009 are significantly different (P < 0.05). The Fisher exact test found a significant association between the presence of the pfcrt T76 mutant allele and in vitro resistance in 2000/2001 (P = 0.023), while in 2009 there were no association between both variables (P = 0.274). Mutant pfcrt T76 and pfmdr1 Y86 alleles and in vitro CQ-resistant strains are still circulating in Pikine. The official discontinuation of CQ use is not completely followed by its total withdrawal from private drug sellers, and the molecule still exerts pressure on local P. falciparum populations.
本研究的目的是评估 2000 年至 2009 年期间塞内加尔皮基纳（Pikine）地区体外氯喹耐药性的演变，以及 pfcrt T76 和 pfmdr1 Y86 突变的流行情况。氯喹（CQ）曾是疟疾的一线治疗药物，而在 2009 年引入青蒿素类复方疗法（ACTs）后，CQ 已不再使用。我们通过 PCR-RFLP 方法对 pfcrt K76T 和 pfmdr1 N86Y 多态性进行基因分型，并通过双位点酶联乳酸脱氢酶免疫检测（DELI）法评估体外 CQ 敏感性，研究对象为 2000 年至 2009 年在塞内加尔皮基纳收集的恶性疟原虫分离株。根据三种不同的治疗政策，pfcrt T76 等位基因的比例分别为：停用 CQ 前（2000 年至 2003 年）为 72.4%，使用阿莫地喹加 Fansidar 作为一线治疗药物时（2004 年至 2005 年）为 47.2%，使用 ACTs 时（2006 年至 2009 年）为 59.5%。停止使用 CQ 后，pfcrt T76 的流行率显著下降[X (2) = 6.54，P = 0.01（2000-2003 年与 2004-2005 年）]，自 ACTs 实施以来略有下降[X(2) = 1.12，P = 0.28（2000-2003 年与 2006-2009 年）]。在三种治疗政策中，pfmdr1 Y86 的流行率没有显著差异。在 2000 年（n = 36）、2001 年（n = 47）和 2009 年（n = 37），我们间歇性地进行了 DELI 检测。2000 年和 2009 年、2001 年和 2009 年分离株对 CQ 的平均 IC（50）值存在显著差异（P < 0.05）。Fisher 确切检验发现，2000 年/2001 年，pfcrt T76 突变等位基因与体外耐药性之间存在显著关联（P = 0.023），而在 2009 年，这两个变量之间没有关联（P = 0.274）。突变型 pfcrt T76 和 pfmdr1 Y86 等位基因以及体外 CQ 耐药株仍在皮基纳流行。CQ 的正式停用并未完全导致其从私人药品供应商中完全撤出，该药物仍对当地恶性疟原虫种群造成压力。
