Research
Brazilian Plasmodium falciparum isolates: investigation of candidate polymorphisms for artemisinin resistance before introduction of artemisinin-based combination therapy
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* Corresponding author: Maria F Ferreira-da-Cruz mffcruz@ioc.fiocruz.br
1 Laboratory of Malaria Research, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro (RJ), Brazil
2 Ambulatory and Laboratory of Malaria Clinical Assays, Secretariat of Health Vigilance, Instituto Evandro Chagas, Belém (PA), Brazil
3 Laboratory of Entomology, LACEN, Porto Velho (RO), Brazil
4 La Jolla Bioengineering Institute, California, USA
5 Fundação de Medicina Tropical do Amazonas, Manaus (AM), Brazil
6 Department of Medicine, San Francisco General Hospital, University of California, San Francisco, USA
Malaria Journal 2010, 9:355 doi:10.1186/1475-2875-9-355
Published: 8 December 2010Abstract
Background
This study was performed to better understand the genetic diversity of known polymorphisms in pfatpase6 and pfmdr1 genes before the introduction of ACT in Brazil, in order to get a genotypic snapshot of Plasmodium falciparum parasites that may be used as baseline reference for future studies.
Methods
Parasites from P. falciparum samples collected in 2002, 2004 and 2006-2007 were genotyped using PCR and DNA sequencing at codons 86, 130, 184, 1034, 1042, 1109 and 1246 for pfmdr1 gene, and 243, 263, 402, 431, 623, 630, 639, 683, 716, 776, 769 and 771 for pfatpase6 gene.
Results
A pfmdr1 haplotype NEF/CDVY was found in 97% of the samples. In the case of pfatpase6, four haplotypes, wild-type (37%), 630 S (35%), 402 V (5%) and double-mutant 630 S + 402 V (23%), were detected.
Conclusion
Although some polymorphism in pfmdr1 and pfatpase6 were verified, no reported haplotypes in both genes that may mediate altered response to ACT was detected before the introduction of this therapy in Brazil. Thus, the haplotypes herein described can be very useful as a baseline reference of P. falciparum populations without ACT drug pressure.