Nor Azrina Norahmad, Noor Rain Abdullah, Norhayati Yaccob, Jenarun Jelip, Jiloris F Dony, Khairul Faiz Ruslan, Lokman Hakim Sulaiman, Hasidah Mohd Sidek, Harald Noedl and Zakiah Ismail (2011). High prevalence of PFCRT K77T mutants among Plasmodium falciparum isolates from Sabah, Malaysia. Southeast Asian Journal of Tropical Medicine and Public Health 42(6): 1322-1326
Chloroquine (CQ) remains the first line drug for the prevention and treatment of malaria in Malaysia in spite of the fact that resistance to CQ has been observed in Malaysia since the 1960s. CQ-resistance is associated with various mutations in pfcrt, which encodes a putative transporter located in the digestive vacuolar membrane of P. falciparum. Substitution of lysine (K) to threonine (T) at amino acid 76 (K76T) in pfcrt is the primary genetic marker conferring resistance to CQ. To determine the presence of T76 mutation in pfcrt from selected areas of Kalabakan, Malaysia 619 blood samples were screened for P. falciparum, out of which 31 were positive. Blood samples were collected on 3 MM® Whatman filter papers and DNA was extracted using QIAmp DNA mini kit. RFLP-PCR for the detection of the CQ-resistant T76 and sensitive K76 genotype was carried out. Twenty-five samples were shown to have the point mutation in pfcrt whereas the remaining samples were classified as CQ-sensitive (wild-type). In view of the fact that CQ is the first line anti-malarial drug in Malaysia, this finding could be an important indication that treatment with CQ may no longer be effective in the future.