Characterisation of kenyan isolates of plasmodium falciparum by isoenzyme electrophoresis and drug sensitivity.

Abstract

Twenty one Kenyan isolates of Plasmodium falciparum were characterised by enzyme electrophoresis and antimalarial drug sensitivity. For isoenzyme analysis, cellulose acetate and thin layer starch gel electrophoresis techniques were employed. P. falciparum isolates from malarious areas of Nyanza, Rift Valley and Coast provinces were cultivated in vitro and used in the isoenzyme study. The enzymes of uninfected red blood cells served as controls. The enzymes studied were: Glucose phosphate isomerase (GPI)(EC 5.3.19), 6-phosphogluconate dehydrogenase (6PGD)(EC 1.1.1.44), Lactate dehydrogenase (LDH)(EC 1.1.1.27), NADPdependent glutamate dehydrogenase (GDH)(EC 1.4.1.4), Adenosine deaminase (ADA)(EC 3.5.4.4) and Peptidase E (PEPE)(EC 3.4.11 or 13). The sensitivitie~ of cultured isolates to seven antimalarial drugs (chloroquine, amodiaquine, quinine, quinidine, mefloquine, pyrimethamine and sulphadoxine) were examined by the in vitro radioisotopic methods of Desjardins et al.(1979) with minor modifications. Variant forms of the enzymes GPI and 6PGD were found in the Kenyan isolates of E. falciparum. GPI enzymes appeared as GPI-l and GPI-2 variants and 6PGD as 6PGD-l and 6PGD-2 variants. The level of enzyme polymorphism was greater in