Plasmodium vivax drug resistance genes; Pvmdr1 and Pvcrt-o polymorphisms in relation to chloroquine sensitivity from a malaria endemic area of Thailand.
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 μl) 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.
College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand.
Kanchana
K
Rungsihirunrat
Drug Discovery and Development Center, Thammasat University, Pathumthani, Thailand.
Poonuch
P
Muhamad
Center of Excellence in Molecular Biology and Pharmacology of Malaria and Cholangiocarcinoma, Chulabhorn International College of Medicine, Thammasat University, Patumthani, Thailand.
Wanna
W
Chaijaroenkul
Graduate Program in Biomedical Sciences, Allied Health Sciences, Thammasat University, Pathumthani, Thailand.
Jiraporn
J
Kuesap
Center of Excellence in Molecular Biology and Pharmacology of Malaria and Cholangiocarcinoma, Chulabhorn International College of Medicine, Thammasat University, Patumthani, Thailand.
Kesara
K
Na-Bangchang
D019943:Amino Acid Substitution; D000962:Antimalarials / Q000494:pharmacology*; D002738:Chloroquine / Q000494:pharmacology*; D004351:Drug Resistance; D006801:Humans; D020128:Inhibitory Concentration 50; D016780:Malaria, Vivax / Q000469:parasitology*; D026901:Membrane Transport Proteins / Q000235:genetics*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D020125:Mutation, Missense; D002052:Myanmar; D021261:Parasitic Sensitivity Tests; D010966:Plasmodium vivax / Q000187:drug effects* / Q000235:genetics; D015800:Protozoan Proteins / Q000235:genetics*; D013785:Thailand
D000962:Antimalarials; D002738:Chloroquine; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015800:Protozoan Proteins; C541685:Crt-o protein, Plasmodium vivax; C541684:Mdr1 protein, Plasmodium vivax
Plasmodium vivax; Pvcrt-o; Pvmdr1; chloroquine; drug resistance