Genetic diversity and multiple infections of Plasmodium vivax malaria in western Thailand
Genetic diversity and multiple infections of Plasmodium vivax malaria in western Thailand
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DOI：
10.4269/ajtmh.2003.68.613
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发表时间：
2003-05-01
影响因子：
3.3
通讯作者：
Sattabongkot, J
中科院分区：
文献类型：
--
作者：
Cui, LW;Mascorro, CN;Sattabongkot, J
使用两个多态性遗传标记，裂殖子表面蛋白-3 α（MSP-3 α）和环子孢子蛋白（CSP），我们调查了2000年4月至2001年6月间日疟原虫在泰国湄索的人口多样性。对从两个当地诊所就诊的90名疟疾患者中分离出的二态CSP基因的寄生虫进行基因分型，发现大多数寄生虫（77%）是VK 210型。MSP 3-α基因分型表明间日疟原虫种群与高流行地区巴布亚新几内亚的种群表现出同样高水平的多态性。根据聚合酶链反应产物的长度，MSP-3 α位点分为三种主要类型，频率分别为74.8%、18.7%和6.5%。限制性片段长度多态性分析区分的13个等位基因的频率没有显示出显着的季节性变化。MSP-3 α和CSP基因分型显示，分别有19.3%和25.6%的患者有多重感染，合并感染率为35.6%。MSP-3 α序列的比较，从9个克隆进一步证实了高水平的遗传多样性的寄生虫，也表明地理隔离可能存在。这些结果有力地表明，间日疟原虫种群是高度多样化的，多克隆感染是常见的，在这个疟疾低流行地区的泰国。
Using two polymorphic genetic markers, the merozoite surface protein-3alpha (MSP-3alpha) and the circumsporozoite protein (CSP), we investigated the population diversity of Plasmodium vivax in Mae Sod, Thailand from April 2000 through June 2001. Genotyping the parasites isolated from 90 malaria patients attending two local clinics for the dimorphic CSP gene revealed that the majority of the parasites (77%) were the VK210 type. Genotyping the MSP3-alpha gene indicated that P. vivax populations exhibited an equally high level of polymorphism as those from Papua New Guinea, a hyperendemic region. Based on the length of polymerase chain reaction products, three major types of the MSP-3alpha locus were distinguished, with frequencies of 74.8%, 18.7%, and 6.5%, respectively. The 13 alleles distinguished by restriction fragment length polymorphism analysis did not show a significant seasonal variation in frequency. Genotyping the MSP-3alpha and CSP genes showed that 19.3% and 25.6% of the patients had multiple infections, respectively, and the combined rate was 35.6%. Comparisons of MSP-3alpha sequences from nine clones further confirmed the high level of genetic diversity of the parasite and also suggested that geographic isolation may exist. These results strongly indicate that P. vivax populations are highly diverse and multiple clonal infections are common in this malaria-hypoendemic region of Thailand.