Diversity and population structure of Plasmodium falciparum in Thailand based on the spatial and temporal haplotype patterns of the C-terminal 19-kDa domain of merozoite surface protein-1

Malaria Journal

Research

Aree Seugorn¹  Napaporn Siripoon¹  Phumin Simpalipan²  Sittiporn Pattaradilokrat²  Pongchai Harnyuttanakorn²  Morakot Kaewthamasorn³  Robert DJ Butcher⁴ 

[1] College of Public Health Sciences, Chulalongkorn University, 10330, Bangkok, Thailand;Department of Biology, Faculty of Science, Chulalongkorn University, 10330, Bangkok, Thailand;Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, 10330, Bangkok, Thailand;Office of Research Affairs, Faculty of Science, Chulalongkorn University, 10330, Bangkok, Thailand;

关键词: Allelic polymorphism;    DNA sequencing;    Merozoite surface antigen;    Population structure;    Southeast Asia;   

DOI  :  10.1186/1475-2875-13-54

 received in 2013-10-03, accepted in 2014-01-27,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundThe 19-kDa C-terminal region of the merozoite surface protein-1 of the human malaria parasite Plasmodium falciparum (Pf MSP-119) constitutes the major component on the surface of merozoites and is considered as one of the leading candidates for asexual blood stage vaccines. Because the protein exhibits a level of sequence variation that may compromise the effectiveness of a vaccine, the global sequence diversity of Pf MSP-119 has been subjected to extensive research, especially in malaria endemic areas. In Thailand, Pf MSP-119 sequences have been derived from a single parasite population in Tak province, located along the Thailand-Myanmar border, since 1995. However, the extent of sequence variation and the spatiotemporal patterns of the MSP-119 haplotypes along the Thai borders with Laos and Cambodia are unknown.MethodsSixty-three isolates of P. falciparum from five geographically isolated populations along the Thai borders with Myanmar, Laos and Cambodia in three transmission seasons between 2002 and 2008 were collected and culture-adapted. The msp-1 gene block 17 was sequenced and analysed for the allelic diversity, frequency and distribution patterns of Pf MSP-119 haplotypes in individual populations. The Pf MSP-119 haplotype patterns were then compared between parasite populations to infer the population structure and genetic differentiation of the malaria parasite.ResultsFive conserved polymorphic positions, which accounted for five distinct haplotypes, of Pf MSP-119 were identified. Differences in the prevalence of Pf MSP-119 haplotypes were detected in different geographical regions, with the highest levels of genetic diversity being found in the Kanchanaburi and Ranong provinces along the Thailand-Myanmar border and Trat province located at the Thailand-Cambodia border. Despite this variability, the distribution patterns of individual Pf MSP-119 haplotypes seemed to be very similar across the country and over the three malarial transmission seasons, suggesting that gene flow may operate between parasite populations circulating in Thailand and the three neighboring countries.ConclusionThe major MSP-119 haplotypes of P. falciparum populations in all endemic populations during three transmission seasons in Thailand were identified, providing basic information on the common haplotypes of MSP-119 that is of use for malaria vaccine development and inferring the population structure of P. falciparum populations in Thailand.

【 授权许可】

Unknown   
© Simpalipan et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.