ANTIMICROBIAL AND ANTIPLASMODIAL ACTIVITY DISPLAYED BY ACTINOMYCETES ISOLATED FROM SOILS FROM KAVANGO AND HARDAP REGIONS IN NAMIBIA

Plasmodium falciparum and multidrug resistant bacteria such as Mycobacterium avium, Staphylococcus aureus and Escherichia coli are among the top causes of morbidity and mortality especially in developing countries. These pathogens are responsible for the reported antibiotic resistance incidents globally. Due to the increase in antibiotic resistance worldwide, there is an urgent need for new bioactive compounds. This study aimed at determining the antiplasmodial and antimicrobial activity of secondary metabolites produced by soil actinomycetes. Soil samples were collected from Kavango and Hardap regions and cultured on various media to isolate and identify actinomycetes. Secondary metabolites produced were extracted using different solvents. The antimicrobial activity of different isolated secondary metabolites was determined against M. avium, S. aureus and E. coli. Antiplasmodial activity of four bioactive fractions with potent antibacterial activity was further determined against a chloroquine resistant (D10) P. falciparum strain at various concentrations. Bioactive compounds from two isolates displayed activity against M. avium, whilst another two showed activity against E. coli. None of the secondary metabolites displayed activity against S. aureus. A concentration dependent reduction in parasitaemia for P. falciparum was observed across all four fractions both after 24 and 48 h. These results display a vast potential antibacterial and antiplasmodial activity and should be considered for future drug development.