洪都拉斯伦皮拉港pfhrp2和pfhrp3基因缺失的患病率

Prevalence of pfhrp2 and pfhrp3 gene deletions in Puerto Lempira, Honduras.

作者信息

Abdallah Joseph F, Okoth Sheila Akinyi, Fontecha Gustavo A, Torres Rosa Elena Mejia, Banegas Engels I, Matute María Luisa, Bucheli Sandra Tamara Mancero, Goldman Ira F, de Oliveira Alexandre Macedo, Barnwell John W, Udhayakumar Venkatachalam

机构信息

Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Road, MS D-67, Atlanta 30333, GA, USA.

出版信息

Malar J. 2015 Jan 21;14:19. doi: 10.1186/s12936-014-0537-7.

DOI:10.1186/s12936-014-0537-7

PMID:25604310

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4308922/

Abstract

BACKGROUND

Recent studies have demonstrated the deletion of the histidine-rich protein 2 (PfHRP2) gene (pfhrp2) in field isolates of Plasmodium falciparum, which could result in false negative test results when PfHRP2-based rapid diagnostic tests (RDTs) are used for malaria diagnosis. Although primary diagnosis of malaria in Honduras is determined based on microscopy, RDTs may be useful in remote areas. In this study, it was investigated whether there are deletions of the pfhrp2, pfhrp3 and their respective flanking genes in 68 P. falciparum parasite isolates collected from the city of Puerto Lempira, Honduras. In addition, further investigation considered the possible correlation between parasite population structure and the distribution of these gene deletions by genotyping seven neutral microsatellites.

METHODS

Sixty-eight samples used in this study, which were obtained from a previous chloroquine efficacy study, were utilized in the analysis. All samples were genotyped for pfhrp2, pfhrp3 and flanking genes by PCR. The samples were then genotyped for seven neutral microsatellites in order to determine the parasite population structure in Puerto Lempira at the time of sample collection.

RESULTS

It was found that all samples were positive for pfhrp2 and its flanking genes on chromosome 8. However, only 50% of the samples were positive for pfhrp3 and its neighboring genes while the rest were either pfhrp3-negative only or had deleted a combination of pfhrp3 and its neighbouring genes on chromosome 13. Population structure analysis predicted that there are at least two distinct parasite population clusters in this sample population. It was also determined that a greater proportion of parasites with pfhrp3-(and flanking gene) deletions belonged to one cluster compared to the other.

CONCLUSION

The findings indicate that the P. falciparum parasite population in the municipality of Puerto Lempira maintains the pfhrp2 gene and that PfHRP2-based RDTs could be considered for use in this region; however continued monitoring of parasite population will be useful to detect any parasites with deletions of pfhrp2.

摘要

背景

近期研究表明，恶性疟原虫的现场分离株中存在富含组氨酸蛋白2（PfHRP2）基因（pfhrp2）的缺失，当使用基于PfHRP2的快速诊断检测（RDT）进行疟疾诊断时，这可能导致假阴性检测结果。虽然洪都拉斯疟疾的初步诊断是基于显微镜检查确定的，但RDT在偏远地区可能有用。在本研究中，调查了从洪都拉斯伦皮拉港城市收集的68株恶性疟原虫分离株中是否存在pfhrp2、pfhrp3及其各自侧翼基因的缺失。此外，通过对七个中性微卫星进行基因分型，进一步研究了寄生虫种群结构与这些基因缺失分布之间的可能相关性。

方法

本研究中使用的68个样本取自先前的氯喹疗效研究，并用于分析。通过PCR对所有样本的pfhrp2、pfhrp3和侧翼基因进行基因分型。然后对样本进行七个中性微卫星的基因分型，以确定样本采集时伦皮拉港的寄生虫种群结构。

结果

发现所有样本的pfhrp2及其8号染色体上的侧翼基因均为阳性。然而，只有50%的样本pfhrp3及其相邻基因呈阳性，其余样本要么仅pfhrp3呈阴性，要么在13号染色体上缺失了pfhrp3及其相邻基因的组合。种群结构分析预测，该样本群体中至少存在两个不同的寄生虫种群簇。还确定，与另一个簇相比，具有pfhrp3（及其侧翼基因）缺失的寄生虫在一个簇中的比例更大。