印度北部昌迪加尔地区复杂和不复杂间日疟原虫分离株中氯喹和抗叶酸药物耐药相关基因的氨基酸突变分布模式。

Distribution pattern of amino acid mutations in chloroquine and antifolate drug resistance associated genes in complicated and uncomplicated Plasmodium vivax isolates from Chandigarh, North India.

机构信息

Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

Department of Virology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

出版信息

BMC Infect Dis. 2020 Sep 15;20(1):671. doi: 10.1186/s12879-020-05397-6.

DOI:10.1186/s12879-020-05397-6

PMID:32933490

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7493319/

Abstract

BACKGROUND

The increasing antimalarial drug resistance is a significant hindrance to malaria control and elimination programs. For the last six decades, chloroquine (CQ) plus pyrimethamine remains the first-line treatment for P. vivax malaria. Regions where both P. falciparum and P. vivax co-exist, P. vivax is exposed to antifolate drugs due to either misdiagnosis or improper treatment that causes selective drug pressure to evolve. Therefore, the present study aims to estimate antimalarial drug resistance among the complicated and uncomplicated P. vivax patients.

METHODS

A total of 143 P. vivax malaria positive patients were enrolled in this study, and DNA was isolated from their blood samples. Pvcrt-o, Pvmdr-1, Pvdhps, and Pvdhfr genes were PCRs amplified, and drug resistance-associated gene mutations were analyzed. Statistical analysis of the drug resistance genes and population diversity was performed using MEGA vs. 7.0.21 and DnaSP v software.

RESULTS

Among the CQ resistance marker gene Pvcrt-o, the prevalence of K10 insertion was 17.5% (7/40) and 9.5% (7/73) of complicated and uncomplicated P vivax group isolates respectively. In Pvmdr-1, double mutant haplotype (M/L) was found in 99% of the clinical isolates. Among the pyrimethamine resistance-associated gene Pvdhfr, the double mutant haplotype IPFRTNI was detected in 23% (11/48) in complicated and 20% (17/85) in uncomplicated group isolates. In the sulphadoxine resistance-associated Pvdhps gene, limited polymorphism was observed with the presence of a single mutant (D459A) among 16 and 5% of the clinical isolates in the complicated and uncomplicated group respectively.

CONCLUSION

The study presents the situations of polymorphism in the antimalarial drug resistance-associated genes and emphasizes the need for regular surveillance. It is imperative for the development of suitable antimalarial drug policy in India.

摘要

背景

抗疟药物的耐药性不断增加，是疟疾控制和消除规划的重大障碍。在过去的六十年里，氯喹（CQ）加乙胺嘧啶仍然是治疗间日疟原虫疟疾的一线药物。在同时存在恶性疟原虫和间日疟原虫的地区，由于误诊或治疗不当，间日疟原虫暴露于抗叶酸药物下，导致药物选择压力下的耐药性进化。因此，本研究旨在评估复杂和不复杂的间日疟原虫患者中的抗疟药物耐药性。

方法

本研究共纳入了 143 例间日疟原虫阳性患者，从他们的血液样本中提取 DNA。通过 PCR 扩增 Pvcrt-o、Pvmdr-1、Pvdhps 和 Pvdhfr 基因，并分析耐药相关基因突变。使用 MEGA vs. 7.0.21 和 DnaSP v 软件对耐药基因和群体多样性进行统计分析。

结果

在 CQ 耐药标记基因 Pvcrt-o 中，复杂和不复杂的间日疟原虫组分离株中 K10 插入的发生率分别为 17.5%（7/40）和 9.5%（7/73）。在 Pvmdr-1 中，99%的临床分离株存在双突变体（M/L）。在嘧啶耐药相关基因 Pvdhfr 中，复杂组中有 23%（11/48），不复杂组中有 20%（17/85）的分离株检测到双重突变体 IPFRTNI。在磺胺多辛耐药相关基因 Pvdhps 中，仅观察到 16%和 5%的临床分离株存在单一突变（D459A），存在有限的多态性。