Plasmodium falciparum merozoite surface protein 1 block 2 gene polymorphism in field isolates along the slope of mount Cameroon: a cross - sectional study.
Plasmodium falciparum merozoite surface protein 1 block 2 gene polymorphism in field isolates along the slope of mount Cameroon: a cross - sectional study.
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DOI：
10.1186/s12879-015-1066-x
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发表时间：
2015-08-05
影响因子：
3.7
通讯作者：
Achidi EA
中科院分区：
文献类型：
--
作者：
Apinjoh TO;Tata RB;Anchang-Kimbi JK;Chi HF;Fon EM;Mugri RN;Tangoh DA;Nyingchu RV;Ghogomu SM;Nkuo-Akenji T;Achidi EA
尽管加强了控制工作，但疟疾仍然是全球主要的健康负担，部分原因是缺乏有效的疫苗。有关自然寄生虫种群遗传多样性的信息是疫苗开发工作的一个主要障碍，在一些流行环境中是有限的。本研究通过调查msp1基因片段2的多态性以及等位基因家族与人口学指标和临床表型的关系来表征基因的多样性。从喀麦隆山坡不同海拔的农村、半农村和半城市地区登记了无症状寄生虫血症(AP)或无并发症疟疾(UM)患者。经光镜筛选的恶性疟原虫血用CF11纤维素柱去除白细胞，用套式聚合酶链式反应进行DNA分型。对15 1株野毒株进行长度多态性分析，发现(5株)和2 74株(2 2株)分别存在明显的重组msp1基因片段和主要等位基因片段(基因型别)。家系特有的等位基因类型(K1、MAD20和RO33)以及MR均出现在不同的位置，其中K1最为丰富。87人(60%)有一个以上的寄生虫克隆，与其他环境相比，农村地区的比例很大(p = 0.009)。与UM患者相比，AP患者K1等位基因频率较高(p = 0.007)，但平均每次感染的基因多样性较低(p = 0.003)(2.00 ± 0.98vs.2.56 ± 1.17)。这些结果表明恶性疟原虫在该地区具有巨大的多样性，并提示等位基因的特异性和复杂性可能与疾病的进展有关。
Malaria remains a major global health burden despite the intensification of control efforts, due partly to the lack of an effective vaccine. Information on genetic diversity in natural parasite populations constitutes a major impediment to vaccine development efforts and is limited in some endemic settings. The present study characterized diversity by investigating msp1 block 2 polymorphisms and the relationship between the allele families with ethnodemographic indices and clinical phenotype. Individuals with asymptomatic parasitaemia (AP) or uncomplicated malaria (UM) were enrolled from rural, semi-rural and semi-urban localities at varying altitudes along the slope of mount Cameroon. P. falciparum malaria parasitaemic blood screened by light microscopy was depleted of leucocytes using CF11 cellulose columns and the parasite DNA genotyped by nested PCR. Length polymorphism was assessed in 151 field isolates revealing 64 (5) and 274 (22) distinct recombinant and major msp1 allelic fragments (genotypes) respectively. All family specific allelic types (K1, MAD20 and RO33) as well as MR were observed in the different locations, with K1 being most abundant. Eighty seven (60 %) of individuals harbored more than one parasite clone, with a significant proportion (p = 0.009) in rural compared to other settings. AP individuals had higher (p = 0.007) K1 allele frequencies but lower (p = 0.003) mean multiplicity of genotypes per infection (2.00 ± 0.98 vs. 2.56 ± 1.17) compared to UM patients. These results indicate enormous diversity of P. falciparum in the area and suggests that allele specificity and complexity may be relevant for the progression to symptomatic disease.