Pratt-Riccio Lilian Rose, Baptista Bárbara de Oliveira, Torres Vanessa Rodrigues, Bianco-Junior Cesare, Perce-Da-Silva Daiana de Souza, Riccio Evelyn Kety Pratt, Lima-Junior Josué da Costa, Totino Paulo Renato Rivas, Cassiano Gustavo Capatti, Storti-Melo Luciane Moreno, Machado Ricardo Luiz Dantas, de Oliveira-Ferreira Joseli, Banic Dalma Maria, Carvalho Leonardo José de Moura, Daniel-Ribeiro Cláudio Tadeu
Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Laboratório de Pesquisa em Malária, Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz, Centro de Pesquisa, Diagnóstico e Treinamento em Malária, Rio de Janeiro, RJ, Brasil.
Mem Inst Oswaldo Cruz. 2019;114:e190054. doi: 10.1590/0074-02760190054. Epub 2019 Aug 12.
The central repetitive region (CRR) of the Plasmodium vivax circumsporozoite surface protein (CSP) is composed of a repetitive sequence that is characterised by three variants: VK210, VK247 and P. vivax-like. The most important challenge in the treatment of P. vivax infection is the possibility of differential response based on the parasite genotype.
To characterise the CSP variants in P. vivax isolates from individuals residing in a malaria-endemic region in Brazil and to profile these variants based on sensitivity to chloroquine and mefloquine.
The CSP variants were determined by sequencing and the sensitivity of the P. vivax isolates to chloroquine and mefloquine was determined by Deli-test.
Although five different allele sizes were amplified, the sequencing results showed that all of the isolates belonged to the VK210 variant. However, we observed substantial genetic diversity in the CRR, resulting in the identification of 10 different VK210 subtypes. The frequency of isolates that were resistant to chloroquine and mefloquine was 11.8 and 23.8%, respectively. However, we did not observe any difference in the frequency of the resistant isolates belonging to the VK210 subtypes.
The VK210 variant is the most frequently observed in the studied region and there is significant genetic variability in the CRR of the P. vivax CSP. Moreover, the antimalarial drug sensitivity profiles of the isolates does not seem to be related to the VK210 subtypes.
间日疟原虫环子孢子表面蛋白（CSP）的中央重复区域（CRR）由一个重复序列组成，该序列具有三种变体特征：VK210、VK247和间日疟原虫样。治疗间日疟原虫感染最重要的挑战是基于寄生虫基因型出现不同反应的可能性。
对来自巴西疟疾流行地区个体的间日疟原虫分离株中的CSP变体进行特征分析，并根据对氯喹和甲氟喹的敏感性对这些变体进行分析。
通过测序确定CSP变体，并通过Deli试验确定间日疟原虫分离株对氯喹和甲氟喹的敏感性。
尽管扩增出了五种不同的等位基因大小，但测序结果表明所有分离株均属于VK210变体。然而，我们在CRR中观察到了大量的遗传多样性，从而鉴定出10种不同的VK210亚型。对氯喹和甲氟喹耐药的分离株频率分别为11.8%和23.8%。然而，我们没有观察到属于VK210亚型的耐药分离株频率有任何差异。
VK210变体是在所研究地区最常观察到的，并且间日疟原虫CSP的CRR中存在显著的遗传变异性。此外，分离株的抗疟药物敏感性谱似乎与VK210亚型无关。
