Diagnosis and Species Discrimination of Positive Malaria Samples by Real-Time Polymerase Chain Reaction

Abstract

OBJECTIVE: Malaria is an important tropical disease that is detected in 198 million people and causes 367-755 thousand deaths annually. Recently, the real-time Polymerase Chain Reaction (PCR) technique has enabled quick determination of Plasmodium spp. and species identification in the same assay with a low contamination risk. In the present study, we aimed to use real-time PCR targeting the 18S rRNA gene to diagnose Plasmodium spp. and perform species identification. METHODS: DNA samples of 15 patients with malaria (14 caused by P. vivax, 1 caused by P. falciparum) confirmed by microscopy as well as positive control plasmids were used. As the negative control, DNA samples of 15 individuals without malaria were used. RESULTS: According to the results of real-time PCR, samples of 15 patients with malaria were found to be positive for Plasmodium spp. Melting curve analysis showed that 14 of them were P. vivax and the remaining was P. falciparum. In addition, mixed infection with P. falciparum and P. vivax was successfully detected by real-time PCR when DNA of P. falciparum- and P. vivax-positive samples was experimentally mixed. CONCLUSION: The present study showed that real-time PCR can be useful in the diagnosis and species identification of Plasmodium spp. as well as the detection of mixed infections in addition to microscopy in Turkey.