Detection of Plasmodium Falciparum in Blood Using Dna Probe, Ppf 14

Abstract

A DNA probe pPF14, which is species specific to P.falciparum have been used to identify malaria species. The blood specimens were pretreated before spotting onto nitrocellulose filter to eliminate non specific hybridization of DNA to blood components. In this study, die DNA probe pPF14 was used for detection of P.falciparum in blood specimens spotted directly (a simple preparation of sample) onto nitrocellulose filter. Ninety two blood specimens from individuals with fever living in a P.falciparum endemic area were collected at the local Primary Health Centre in Lampung. Blood was collected by finger prick technique using heparinized capillary tubes. Twenty microliter of blood was plotted directly onto nitrocellulose filter, extracted, treated with proteinase K and tested with DNA probe pPF14. Another 20 microliter of blood was used for thick smear and examined microscopically. Nineteen out of 92 (20,7 %) of the blood specimens were found to contain P.falciparum parasites by DNA probing and by thick smear. The densities of parasites ranged from 350 to 28,775 per microliter. The jDNA probing technique was successfully done for the detection of P.falciparum in the laboratory. However, this technique seems not to be quite sensitive for parasitological survey (detects 40-50 parasites per microliter of blood); while using thick smear examination, 5-10 parasites per microliter of blood could be detected with confidence. The important issue in this case is that no special treatment before spotting the blood onto nitrocellulose filter was needed to eliminate non-specific hybridization, when protease treatment was used. Collection of specimens would be easily done in the field