Limits...
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.

Show MeSH

Related in: MedlinePlus

Malaria incidences in Huaiyuan, Mengcheng, Yongcheng and Guangshui Counties from year 1990 to 2009 from case report system.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3108914&req=5

Figure 2: Malaria incidences in Huaiyuan, Mengcheng, Yongcheng and Guangshui Counties from year 1990 to 2009 from case report system.

Mentions: From Figure 2, malaria reemerged in Yongcheng, Mengcheng and Huaiyuan Counties from 2000 and the incidence of Yongcheng County was highest with 122.41/100,000 in 2007 while malaria is relatively stable in Guangshui City. In these areas, there was a plain landscape with soybean as the primary crop, and it was a fixed vectorial area, including An. sinensis and An. anthropophagus based on historical vectorial investigations in the Huang-Huai River region. The average vector capacity in this area was 0.1686 in 1990's.


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)

Malaria incidences in Huaiyuan, Mengcheng, Yongcheng and Guangshui Counties from year 1990 to 2009 from case report system.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: Malaria incidences in Huaiyuan, Mengcheng, Yongcheng and Guangshui Counties from year 1990 to 2009 from case report system.
Mentions: From Figure 2, malaria reemerged in Yongcheng, Mengcheng and Huaiyuan Counties from 2000 and the incidence of Yongcheng County was highest with 122.41/100,000 in 2007 while malaria is relatively stable in Guangshui City. In these areas, there was a plain landscape with soybean as the primary crop, and it was a fixed vectorial area, including An. sinensis and An. anthropophagus based on historical vectorial investigations in the Huang-Huai River region. The average vector capacity in this area was 0.1686 in 1990's.

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