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Monitoring resistance of Plasmdium vivax: point mutations in dihydrofolate reductase gene in isolates from Central China.

Huang F, Zhou S, Zhang S, Li W, Zhang H - Parasit Vectors (2011)

Bottom Line: Antifolate resistance in Plasmodium vivax is caused by point mutations in genes encoding dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps).Three types of single mutation (S58R, T61M and S117N) were found in 2.1%, 11.8% and 20.9% of parasite isolates, respectively.And it also highlights genotyping in the pvdhfr genes remains a useful tool to monitor the emergence and spread of P. vivax pyrimethamine resistance.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, PR China.

ABSTRACT

Background: Malaria still represents a significant public health problem in China, and the cases dramatically increased in Central China after 2001. Antifolate resistance in Plasmodium vivax is caused by point mutations in genes encoding dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps). In this study, we used direct sequencing to investigate genetic variation in pvdhfr of malaria patients' samples from Central China.

Results: Among all the samples, 21.4% were wild-type, whereas mutations were detected at three codons (58, 61 and 117) including single mutant (34.6%) and double mutants (43.8%). The most prevalent mutant allele was the one with double mutation at codons 58 and 117 (24.6%). Three types of single mutation (S58R, T61M and S117N) were found in 2.1%, 11.8% and 20.9% of parasite isolates, respectively. The four P. vivax parasite populations in Central China also differed in pvdhfr allele frequencies.

Conclusions: This study suggested that P. vivax in Central China may be relatively susceptible to pyrimethamine. And it also highlights genotyping in the pvdhfr genes remains a useful tool to monitor the emergence and spread of P. vivax pyrimethamine resistance.

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Map of distribution sentinel sites and mutant pvdhfr in Central China.
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Figure 1: Map of distribution sentinel sites and mutant pvdhfr in Central China.

Mentions: In recent years the re-emergence of malaria was considerable in Central China, especially along the Huang-Huai River. Four counties in three provinces located in Central China were selected for collecting blood samples (Figure 1). The counties were Huaiyuan and Mengcheng county in Anhui Province, Yongcheng county in Henan Province, Guangshui city in Hubei Province. All the counties were located at 32°17'~34°18' north latitude, 113°~117°09' east longitude with malaria re-emergence in recent years.


Monitoring resistance of Plasmdium vivax: point mutations in dihydrofolate reductase gene in isolates from Central China.

Huang F, Zhou S, Zhang S, Li W, Zhang H - Parasit Vectors (2011)

Map of distribution sentinel sites and mutant pvdhfr in Central China.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108914&req=5

Figure 1: Map of distribution sentinel sites and mutant pvdhfr in Central China.
Mentions: In recent years the re-emergence of malaria was considerable in Central China, especially along the Huang-Huai River. Four counties in three provinces located in Central China were selected for collecting blood samples (Figure 1). The counties were Huaiyuan and Mengcheng county in Anhui Province, Yongcheng county in Henan Province, Guangshui city in Hubei Province. All the counties were located at 32°17'~34°18' north latitude, 113°~117°09' east longitude with malaria re-emergence in recent years.

Bottom Line: Antifolate resistance in Plasmodium vivax is caused by point mutations in genes encoding dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps).Three types of single mutation (S58R, T61M and S117N) were found in 2.1%, 11.8% and 20.9% of parasite isolates, respectively.And it also highlights genotyping in the pvdhfr genes remains a useful tool to monitor the emergence and spread of P. vivax pyrimethamine resistance.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, PR China.

ABSTRACT

Background: Malaria still represents a significant public health problem in China, and the cases dramatically increased in Central China after 2001. Antifolate resistance in Plasmodium vivax is caused by point mutations in genes encoding dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps). In this study, we used direct sequencing to investigate genetic variation in pvdhfr of malaria patients' samples from Central China.

Results: Among all the samples, 21.4% were wild-type, whereas mutations were detected at three codons (58, 61 and 117) including single mutant (34.6%) and double mutants (43.8%). The most prevalent mutant allele was the one with double mutation at codons 58 and 117 (24.6%). Three types of single mutation (S58R, T61M and S117N) were found in 2.1%, 11.8% and 20.9% of parasite isolates, respectively. The four P. vivax parasite populations in Central China also differed in pvdhfr allele frequencies.

Conclusions: This study suggested that P. vivax in Central China may be relatively susceptible to pyrimethamine. And it also highlights genotyping in the pvdhfr genes remains a useful tool to monitor the emergence and spread of P. vivax pyrimethamine resistance.

Show MeSH
Related in: MedlinePlus