Relatively little progress has been made towards the production of suitable vaccines for any of the protozoan species and the emergence of drug-resistant strains has made the development of new drugs an urgent issue. Knowledge of the basic biochemistry and molecular biology of these parasites remains scant and this undoubtedly contributes to the lack of progress in developing new drugs and vaccines to control the diseases they cause. The leishmaniases form a group of tropical and sub-tropical diseases with about 12 million new cases worldwide each year. Leishmania major and L. tropica are the causative agents for cutaneous leishmaniasis or oriental sore. Crithidia luciliae is a non-pathogenic organism which is used as an experimental model for the infectious genera, with the advantage that it can be grown in relatively large amounts.
Malaria is a disease caused by infection of the red cells by the malarial parasite.
Recently this disease has become a major problem worldwide, due to resistance of the parasite to most known drugs. The research in this department is aimed at a rational approach to the development of new antiparasitic agents in malaria by investigating biochemical pathways which are different in the parasite compared to the host and by cloning some of the parasite genes which are essential for the survival and reproduction of the parasite. Research in this laboratory involves the design of new antimalarials by determining new pathways induced by the malarial parasite, which are different to that of the host red cell. One such pathway which we have demonstrated to be different is the salvage or transport of nucleosides across the membrane into the malarial infected cell. Plasmodium falciparum the intraerythrocytic malarial parasite, which is maintained in in vitro culture in the laboratory, has been shown to lack de novo purine biosynthesis and thus is dependent on purine salvage for the essential components of its nucleic acids.