来自巴西流行地区的间日疟原虫分离株中缺乏与磺胺多辛-乙胺嘧啶耐药性相关的四重和五重突变等位基因。

Lack of quadruple and quintuple mutant alleles associated with sulfadoxine-pyrimethamine resistance in Plasmodium vivax isolates from Brazilian endemic areas.

作者信息

Gomes Larissa Rodrigues, Lavigne Aline, Brasil Patrícia, Peterka Cassio Leonel, Ménard Didier, Daniel-Ribeiro Cláudio Tadeu, Ferreira-da-Cruz Maria de Fátima

机构信息

Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Pesquisa em Malária, Rio de Janeiro, RJ, Brasil.

Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisa, Diagnóstico e Treinamento em Malária, Rio de Janeiro, RJ, Brasil.

出版信息

Mem Inst Oswaldo Cruz. 2019 Feb 4;114:e180425. doi: 10.1590/0074-02760180425.

DOI:10.1590/0074-02760180425

PMID:30726345

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6364293/

Abstract

BACKGROUND AND OBJECTIVE

Brazil is responsible for a large number of Plasmodium vivax cases in America. Given the emergence of P. vivax parasites resistant to chloroquine and the effectiveness of antifolates in vivax malaria treatment together with a correlation between mutations in P. vivax dhfr and dhps genes and SP treatment failure, the point mutations in these genes were investigated.

METHODS

Blood samples from 54 patients experiencing vivax malaria symptomatic episodes in the Amazonian Region were investigated. Genomic DNA was extracted using a DNA extraction kit (QIAGENTM). Nested polymerase chain reaction (PCR) amplification was carried out followed by Sanger sequencing to detect single nucleotide polymorphisms (SNPs).

FINDINGS

All tested isolates showed non-synonymous mutations in pvdhfr gene: 117N (54/54, 100%) and 58R (25/54, 46%). Double mutant allele 58R/117N (FRTNI, 28%) was the most frequent followed by triple mutant alleles (58R/117N/173L, FRTNL, 11%; 58R/61M/117N, FRMNI, 5% 117N/173L, FSTNL, 4%) and quadruple mutant allele (58R/61M/117N/173L, FRMNL, 2%). A single mutation was observed at codon C383G in pvdhps gene (SGKAV, 48%).

CONCLUSION

No evidence of molecular signatures associated with P. vivax resistance to SP was observed in the Brazilian samples.

摘要

背景与目的

巴西是美洲间日疟原虫病例的主要来源地。鉴于出现了对氯喹耐药的间日疟原虫寄生虫，且抗叶酸药物在间日疟治疗中有效，同时间日疟二氢叶酸还原酶（dhfr）和二氢蝶酸合成酶（dhps）基因的突变与磺胺多辛-乙胺嘧啶（SP）治疗失败相关，因此对这些基因的点突变进行了研究。

方法

对亚马逊地区54例有间日疟症状发作的患者的血样进行了研究。使用DNA提取试剂盒（QIAGENTM）提取基因组DNA。进行巢式聚合酶链反应（PCR）扩增，随后进行桑格测序以检测单核苷酸多态性（SNP）。

结果

所有测试分离株的pvdhfr基因均显示非同义突变：117N（54/54，100%）和58R（25/54，46%）。双突变等位基因58R/117N（FRTNI，28%）最为常见，其次是三突变等位基因（58R/117N/173L，FRTNL，11%；58R/61M/117N，FRMNI，5%；117N/173L，FSTNL，4%）和四突变等位基因（58R/61M/117N/173L，FRMNL，2%）。在pvdhps基因的C383G密码子处观察到单个突变（SGKAV，48%）。