SHORT REPORT: POLYMORPHISMS IN THE CHLOROQUINE RESISTANCE TRANSPORTER GENE IN PLASMODIUM FALCIPARUM ISOLATES FROM LOMBOK, INDONESIA

The polymorphisms in the Plasmodium falciparum multidrug resistance 1 (pfmdr1) and P. falciparum chloroquine resistance transporter (pfcrt) genes, which are associated with chloroquine resistance, were examined in 48 P. falciparum isolates from uncomplicated malaria patients from the West Lombok District in Indonesia. The point mutation N86Y in pfmdr1 was present in 35.4% of the isolates and mutation K76T in pfcrt was found in all but one of the samples studied. Identified pfcrt haplotypes were mainly identical to the Papua New Guinea type SagtVMNT (42 of 48, 87.5%), and a few isolates had the Southeast Asia type CVIET (5 of 48, 10.4%). Moreover, one P. falciparum isolate harbored the K76N mutation, giving rise to the haplotype CVMNN, which was not previously reported in field isolates. Our findings suggest that chloroquine resistance in this area might have the same origin as in Papua New Guinea. The mechanism of chloroquine (CQ) resistance in Plasmo- dium falciparum has been investigated and mutations in the P. falciparum CQ resistance transporter gene (pfcrt) located on chromosome 7, and the P. falciparum multidrug resistant gene 1 (pfmdr1), located on chromosome 5, have been impli- cated. The substitution of threonine for lysine in codon 76, K76T in the pfcrt gene, was shown in vitro to be associated with CQ resistance in isolates from Asia, Africa, South Amer- ica, and Papua New Guinea. 1,2 Sequence polymorphisms at position 72-76 of this gene have been associated with the geographic origin of parasite samples, with the CVIET pat- tern in resistant isolates from Asia and Africa, and with SVMNT in resistant isolates from Papua New Guinea and South America. 1,3 The multidrug resistant gene pfmdr1 with a