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Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country
BACKGROUND: The population structure of the causative agents of human malaria, Plasmodium sp., including the most serious agent Plasmodium falciparum, depends on the local epidemiological and demographic situations, such as the incidence of infected people, the vector transmission intensity and migr...
Autores principales: | , , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2009
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2722663/ https://www.ncbi.nlm.nih.gov/pubmed/19602241 http://dx.doi.org/10.1186/1475-2875-8-155 |
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author | Pumpaibool, Tepanata Arnathau, Céline Durand, Patrick Kanchanakhan, Naowarat Siripoon, Napaporn Suegorn, Aree Sitthi-amorn, Chitr Renaud, François Harnyuttanakorn, Pongchai |
author_facet | Pumpaibool, Tepanata Arnathau, Céline Durand, Patrick Kanchanakhan, Naowarat Siripoon, Napaporn Suegorn, Aree Sitthi-amorn, Chitr Renaud, François Harnyuttanakorn, Pongchai |
author_sort | Pumpaibool, Tepanata |
collection | PubMed |
description | BACKGROUND: The population structure of the causative agents of human malaria, Plasmodium sp., including the most serious agent Plasmodium falciparum, depends on the local epidemiological and demographic situations, such as the incidence of infected people, the vector transmission intensity and migration of inhabitants (i.e. exchange between sites). Analysing the structure of P. falciparum populations at a large scale, such as continents, or with markers that are subject to non-neutral selection, can lead to a masking and misunderstanding of the effective process of transmission. Thus, knowledge of the genetic structure and organization of P. falciparum populations in a particular area with neutral genetic markers is needed to understand which epidemiological factors should be targeted for disease control. Limited reports are available on the population genetic diversity and structure of P. falciparum in Thailand, and this is of particular concern at the Thai-Myanmar and Thai-Cambodian borders, where there is a reported high resistance to anti-malarial drugs, for example mefloquine, with little understanding of its potential gene flow. METHODS: The diversity and genetic differentiation of P. falciparum populations were analysed using 12 polymorphic apparently neutral microsatellite loci distributed on eight of the 14 different chromosomes. Samples were collected from seven provinces in the western, eastern and southern parts of Thailand. RESULTS: A strong difference in the nuclear genetic structure was observed between most of the assayed populations. The genetic diversity was comparable to the intermediate level observed in low P. falciparum transmission areas (average H(S )= 0.65 ± 0.17), where the lowest is observed in South America and the highest in Africa. However, uniquely the Yala province, had only a single multilocus genotype present in all samples, leading to a strong geographic differentiation when compared to the other Thai populations during this study. Comparison of the genetic structure of P. falciparum populations in Thailand with those in the French Guyana, Congo and Cameroon revealed a significant genetic differentiation between all of them, except the two African countries, whilst the genetic variability of P. falciparum amongst countries showed overlapping distributions. CONCLUSION: Plasmodium falciparum shows genetically structured populations across local areas of Thailand. Although Thailand is considered to be a low transmission area, a relatively high level of genetic diversity and no linkage disequilibrium was found in five of the studied areas, the exception being the Yala province (Southern peninsular Thailand), where a clonal population structure was revealed and in Kanchanaburi province (Western Thailand). This finding is particularly relevant in the context of malaria control, because it could help in understanding the special dynamics of parasite populations in areas with different histories of, and exposure to, drug regimens. |
format | Text |
id | pubmed-2722663 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2009 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-27226632009-08-07 Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country Pumpaibool, Tepanata Arnathau, Céline Durand, Patrick Kanchanakhan, Naowarat Siripoon, Napaporn Suegorn, Aree Sitthi-amorn, Chitr Renaud, François Harnyuttanakorn, Pongchai Malar J Research BACKGROUND: The population structure of the causative agents of human malaria, Plasmodium sp., including the most serious agent Plasmodium falciparum, depends on the local epidemiological and demographic situations, such as the incidence of infected people, the vector transmission intensity and migration of inhabitants (i.e. exchange between sites). Analysing the structure of P. falciparum populations at a large scale, such as continents, or with markers that are subject to non-neutral selection, can lead to a masking and misunderstanding of the effective process of transmission. Thus, knowledge of the genetic structure and organization of P. falciparum populations in a particular area with neutral genetic markers is needed to understand which epidemiological factors should be targeted for disease control. Limited reports are available on the population genetic diversity and structure of P. falciparum in Thailand, and this is of particular concern at the Thai-Myanmar and Thai-Cambodian borders, where there is a reported high resistance to anti-malarial drugs, for example mefloquine, with little understanding of its potential gene flow. METHODS: The diversity and genetic differentiation of P. falciparum populations were analysed using 12 polymorphic apparently neutral microsatellite loci distributed on eight of the 14 different chromosomes. Samples were collected from seven provinces in the western, eastern and southern parts of Thailand. RESULTS: A strong difference in the nuclear genetic structure was observed between most of the assayed populations. The genetic diversity was comparable to the intermediate level observed in low P. falciparum transmission areas (average H(S )= 0.65 ± 0.17), where the lowest is observed in South America and the highest in Africa. However, uniquely the Yala province, had only a single multilocus genotype present in all samples, leading to a strong geographic differentiation when compared to the other Thai populations during this study. Comparison of the genetic structure of P. falciparum populations in Thailand with those in the French Guyana, Congo and Cameroon revealed a significant genetic differentiation between all of them, except the two African countries, whilst the genetic variability of P. falciparum amongst countries showed overlapping distributions. CONCLUSION: Plasmodium falciparum shows genetically structured populations across local areas of Thailand. Although Thailand is considered to be a low transmission area, a relatively high level of genetic diversity and no linkage disequilibrium was found in five of the studied areas, the exception being the Yala province (Southern peninsular Thailand), where a clonal population structure was revealed and in Kanchanaburi province (Western Thailand). This finding is particularly relevant in the context of malaria control, because it could help in understanding the special dynamics of parasite populations in areas with different histories of, and exposure to, drug regimens. BioMed Central 2009-07-14 /pmc/articles/PMC2722663/ /pubmed/19602241 http://dx.doi.org/10.1186/1475-2875-8-155 Text en Copyright © 2009 Pumpaibool et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 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 cited. |
spellingShingle | Research Pumpaibool, Tepanata Arnathau, Céline Durand, Patrick Kanchanakhan, Naowarat Siripoon, Napaporn Suegorn, Aree Sitthi-amorn, Chitr Renaud, François Harnyuttanakorn, Pongchai Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country |
title | Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country |
title_full | Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country |
title_fullStr | Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country |
title_full_unstemmed | Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country |
title_short | Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country |
title_sort | genetic diversity and population structure of plasmodium falciparum in thailand, a low transmission country |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2722663/ https://www.ncbi.nlm.nih.gov/pubmed/19602241 http://dx.doi.org/10.1186/1475-2875-8-155 |
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