Point Mutations of Pfcrt Gene in Patients aged 1-18 years with Falciparum Malaria
in Ogan Komering Ulu District in South Sumatra Province
Rosiana A Marbun
Plasmodium resistance to antimalarial drugs is the most difficult factor to overcome because mutations in the genome of Plasmodium are difficult to control. Today it appears that some strains of P. falciparum are resistant to chloroquine. Strains of P. falciparum which is chloroquine-resistant can survive because it can reduce the accumulation of chloroquine in the digestive vacuole. The findings in recent years state that the resistance of P. falciparum to chloroquine mainly caused by the mutation in the P. falciparum chloroquine resistance transporter (pfcrt) gene. The objectives of this study were to identify and describe the distribution pattern of point mutations at codon 72, 74, 75, 76, 97, 144, 160, 220, 271, 326, 356, and 371 P. Falciparum pfcrt gene based on demographics and topography in Ogan Komering Ulu (OKU), South Sumatra. This study was a descriptive study of molecular epidemiology exploratory in children aged 1-18 years in three malaria-endemic areas which represents OKU-South Sumatra, namely the Tanjung Lengkayap, Banding Agung, and Belitang. The stages of this research were the determination of spleen rate, collecting subjects, clinical malaria diagnosis, microscopic examination of thick and thin stocks of blood specimens, test of chloroquine resistance in vivo, DNA isolation, PCR, and sequencing. Based on the value of spleen rate, those 3 regions were grouped into hypoendemic malaria. Of the 562 samples tested, 171 samples were obtained with falciparum malaria observed by microscopic examination of thin blood supply. Twenty-five (25) samples failed the test of chloroquine resistance in vitro, and the next 146 samples would be proceeded to take resistance test in vivo which, later, it was found that 44 samples were resistant to chloroquine. Three (3) samples showed that results of DNA isolations were negative. One hundred sixty-eight (168) samples of pfcrt gene DNA were successfully analyzed by conducting isolation, PCR, and sequencing. As a result, a point mutation was found at codons 74, 75, 76, 97, 220, and 356, namely M74I, N75L, K76T, H97F, A220S, and I356L . The pattern of distribution of point mutations in Tanjung Lengkayap, Banding Agung, and Belitang was 100% in codons 74,75,76, and 356, while at codon 97 was respectively 44%, 46.9%, and 60%, , at codon 220 was respectively 40.5%, 46.9%, and 60%. This research concluded that Tanjung Lengkayap, Banding Agung, and Belitang were hypoendemic region. Point mutations 100% occurred at codons 74.75, 76, and 356 of P.falciparum pfcrt gene. Distribution of point mutations at codons 97 and 220 were mostly found in Belitang. Multiple point mutations were found in the entire sample. A new local point mutation at codons 75 and 97 of P. falciparum pfcrt gene was found. This has never been found in other places.