Korean J Parasitol.  2015 Feb;53(1):43-49. 10.3347/kjp.2015.53.1.43.

Plasmodium vivax Drug Resistance Genes; Pvmdr1 and Pvcrt-o Polymorphisms in Relation to Chloroquine Sensitivity from a Malaria Endemic Area of Thailand

• Rungsihirunrat K
• Muhamad P
• Chaijaroenkul W
• Kuesap J
• Na-Bangchang K

• KMID: 2381795
• DOI: http://doi.org/10.3347/kjp.2015.53.1.43

Abstract

The aim of the study was to explore the possible molecular markers of chloroquine resistance in Plasmodium vivax isolates in Thailand. A total of 30 P. vivax isolates were collected from a malaria endemic area along the Thai-Myanmar border in Mae Sot district of Thailand. Dried blood spot samples were collected for analysis of Pvmdr1 and Pvcrt-o polymorphisms. Blood samples (100 mul) were collected by finger-prick for in vitro chloroquine susceptibility testing by schizont maturation inhibition assay. Based on the cut-off IC50 of 100 nM, 19 (63.3%) isolates were classified as chloroquine resistant P. vivax isolates. Seven non-synonymous mutations and 2 synonymous were identified in Pvmdr1 gene. Y976F and F1076L mutations were detected in 7 (23.3%) and 16 isolates (53.3%), respectively. Analysis of Pvcrt-o gene revealed that all isolates were wild-type. Our results suggest that chloroquine resistance gene is now spreading in this area. Monitoring of chloroquine resistant molecular markers provide a useful tool for future control of P. vivax malaria.

Keyword

Plasmodium vivax; Pvmdr1; Pvcrt-o; drug resistance; chloroquine

MeSH Terms

Amino Acid Substitution
Antimalarials/*pharmacology
Chloroquine/*pharmacology
*Drug Resistance
Humans
Inhibitory Concentration 50
Malaria, Vivax/*parasitology
Membrane Transport Proteins/*genetics
Multidrug Resistance-Associated Proteins/*genetics
Mutation, Missense
Myanmar
Parasitic Sensitivity Tests
Plasmodium vivax/*drug effects/genetics
Protozoan Proteins/*genetics
Thailand
Antimalarials
Chloroquine
Membrane Transport Proteins
Multidrug Resistance-Associated Proteins
Protozoan Proteins