Introduction
Development and spread of P.falciparum resistance to commonly used antimalarial drugs is a major obstacle to achieve malaria elimination. Several questions remain concerning the risk of selection of genetic alterations associated with resistance and how such alterations effect the parasite growth (fitness). Information regarding the cost-benefit of antimalarial drug resistance is crucial to understand the selection and transmission of resistant P. falciparum parasites to possibly optimize drug policies and prevent re-emerging drug resistance.
We are performing an in vitro study on commonly used antimalarial drugs to determine to what extent and how increased resistance and decreased fitness simultaneously affect parasite competitiveness and selection.

Material and Methods
Two genetically modified isogenic clones only differing in the crucial P. falciparum chloroquine resistance transporter gene (pfcrt) are used to explore the cost-benefit effect in comparison with parasites without the alterations i.e. “wild-type” parasites. Parasite fitness is determined through pair-wise growth competition experiments between the clones grown separately or in indirect contact through transwell membranes. Parasite drug susceptibilities are determined with Elisa. From this data we determine the fitness cost and the benefit of resistance and as such the risk of selection and spread of resistant parasites.

Main objective for the student project
To further analyse the mechanism behind decreased fitness we will characterize the parasite growth in blood cultures. The student will learn:
1.Different techniques for culturing of malaria parasites in vitro
2.Microscopic examination and characterisation of parasites
3.Elisa methods
4.Differentiation of parasite clones with sequencing
5.Writing and presentation of results