Malaria Genomics Research and Training Centre, Department of Biochemistry & Nutrition, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria.
Medical Research Council Unit, the Gambia - The London School of Hygiene and Tropical Medicine, Fajara, Banjul, Gambia.
Front Cell Infect Microbiol. 2024 Apr 23;14:1366563. doi: 10.3389/fcimb.2024.1366563. eCollection 2024.
Routine surveillance for antimalarial drug resistance is critical to sustaining the efficacy of artemisinin-based Combination Therapies (ACTs). and non- artemisinin ART) resistance-associated mutations are uncommon in Africa. We investigated polymorphisms in actin-binding protein (Pfcoronin associated with reduced sensitivity to ART in Nigeria.
Fifty-two malaria subjects who met the inclusion criteria were followed up in a 28-day therapeutic efficacy study of artemether-lumefantrine in Lagos, Nigeria. Parasite detection was done by microscopy and molecular diagnostic approaches involving PCR amplification of genes for 18S rRNA, ATS, telomere-associated repetitive elements-2 (TARE-2). and genes were sequenced bi-directionally while clonality of infections was determined using 12 neutral microsatellite and analyses. Antimalarial drugs (sulfadoxine-pyrimethamine, amodiaquine, chloroquine and some quinolones) resistance variants (DHFR_51, DHFR_59, DHFR_108, DHFR_164, MDR1_86, MDR1_184, DHPS_581 and DHPS_613) were genotyped by high-resolution melting (HRM) analysis.
A total of 7 (26.92%) cases were identified either as early treatment failure, late parasitological failure or late clinical failure. Of the four post-treatment infections identified as recrudescence by genotypes, only one was classified as recrudescence by multilocus microsatellites genotyping. Microsatellite analysis revealed no significant difference in the mean allelic diversity, , (P = 0.19, Mann-Whitney test). Allele sizes and frequency per locus implicated one isolate. Genetic analysis of this isolate identified two new SNVs (I68G and L173F) in addition to the P76S earlier reported. Linkage-Disequilibrium as a standardized association index, , between multiple loci revealed significant LD ( = 0.2865, =0.02, Monte-Carlo simulation) around the neutral microsatellite loci. The drug resistance-associated haplotypes combinations, (108/51164/59/581/86/184), were observed in two samples.
mutations identified in this study, with potential to impact parasite clearance, may guide investigations on emerging ART tolerance in Nigeria, and West African endemic countries.
常规监测抗疟药物耐药性对于维持青蒿素为基础的联合疗法（ACTs）的疗效至关重要。在非洲，青蒿素耐药相关突变和非青蒿素 ART 耐药相关突变并不常见。我们研究了与尼日利亚青蒿素类药物敏感性降低相关的肌动蛋白结合蛋白（Pfcoronin）多态性。
在尼日利亚拉各斯进行的青蒿琥酯-咯萘啶 28 天疗效研究中，对符合纳入标准的 52 名疟疾患者进行了随访。通过显微镜检查和涉及 18S rRNA、ATS、端粒相关重复元件-2（TARE-2）基因 PCR 扩增的分子诊断方法进行寄生虫检测。PfCRT 和 Pfcrt 基因进行了双向测序，而感染的克隆性则使用 12 个中性微卫星和分析来确定。抗疟药物（磺胺多辛-乙胺嘧啶、阿莫地喹、氯喹和一些喹诺酮类药物）耐药变异（DHFR_51、DHFR_59、DHFR_108、DHFR_164、MDR1_86、MDR1_184、DHPS_581 和 DHPS_613）通过高分辨率熔解（HRM）分析进行基因分型。
共有 7 例（26.92%）患者被确定为早期治疗失败、晚期寄生虫学失败或晚期临床失败。在通过基因型鉴定的 4 例治疗后感染中，只有 1 例被多基因座微卫星基因分型归类为复发。微卫星分析显示，平均等位基因多样性、、（P=0.19，曼-惠特尼检验）无显著差异。每个基因座的等位基因大小和频率提示一个分离株。对该分离株的遗传分析除了早期报道的 P76S 外，还发现了两个新的 SNVs（I68G 和 L173F）。多个基因座的连锁不平衡作为标准化关联指数，、（=0.2865，=0.02，蒙特卡罗模拟）显示中性微卫星基因座周围存在显著的 LD。在两个样本中观察到与药物耐药相关的单倍型组合，（108/51164/59/581/86/184）。
本研究中鉴定的突变可能会影响寄生虫清除，这可能会指导尼日利亚和西非流行国家对新兴 ART 耐受性的研究。
