The clonal composition of the P. falciparum population in the course of the in-vitro cultivation

Original article


Aisha Gashot 1,Walter Maier 2, Helge Kamper 2

1-Department of Serology & Immuno-logy, Central Hospital, Tripoli, Libya2- Institute of medical Parasitology, University of Bonn, Germany

Libyan J Infect Dis. Vol. 1, No.1. Jan-2007:32-39


Objectives: In the present study, alterations in P.falciparum parasite population composition, caused by selective adaptation to the culture conditions, were examined by polymerase chain reaction (PCR). In the course of these experiments such alterations were induced by potentially mutagenic UV-radiation imploring different UV doses for different periods of time. Materials and Methods: Six deep frozen stabilates of the NF54-strain of P. falciparum (named A, B, C, D, E, and F) as well as the clone TM106-R2 and the stabilate CH1501- were thawed and cultivated under various conditions for a period of 4 and 6 months. While cultivating, samples were taken several times for molecular biological typing of presence of dominant parasite clones. In a parallel experiment, two of the cultivated stabilates (E and F) were exposed to different doses of UV-radiation. The UV-treatment of the cultures was performed with the DNA-Cross-linker FLUO-LINK while the open culture dishes were placed in the device drawer. Analysis of molecular biology of the clonal composition was performed by PCR. Results: UV-light had an effect on the development of the parasites but this could not be verified on the DNA level. The presented different stabilates of the NF54-strain of P.falciparum displayed changes in the genotyping pattern caused by different culture conditions. The analysis of a small number of genetic markers (in this case four) is often sufficient to detect such changes in a culture.Conclusion: UV-light had an effect on the development of the malaria parasites but this could not be verified on the DNA level. Mutations induced by UV-radiation normally are point mutations which are not detectable by common gel electrophoresis. Further investigations are necessary to explain the complex processes induced in malaria parasites by UV-irradiation.

Keywords: Malaria, Parasites, Plasmodium falciparum, Polymerase chain reaction, UV-irradiation