Assessment of Some Bacteria from Panteka Stream, Kaduna, Nigeria, for their Larvicidal Activity Against Anopheles gambiae

It is obvious that malaria is one of the commonest diseases in Africa, hence the need to embark on a study to reduce its transmission by eliminating the vector. Some microorganisms are known to have larvicidal activity leading to destruction of mosquito larvae, thereby, preventing them from metamorphosing into adult mosquitoes that can transmit Plasmodium spp. Panteka stream, Kaduna, Nigeria, is a dumping site for refuse and automobile waste and thus, a potential source of bacteria. This present investigation was aimed at screening bacterial isolates for their larvicidal activity against Anopheles gambiae. Standard methods were employed in sample collection, isolation, morphological, biochemical identification and protein profiling of these bacteria isolates. Five different types of bacteria were identified; Bacillus thuringiensis, Staphylococcus aureus, Micrococcus sedentarius, Enterococcus faecalis and Streptococcus pneumonia. Among these bacteria, B. thuringiensis exhibited the most larvicidal activity, followed by M. sedentarius. On the basis of lethal concentration (LC50), B. thuringiensis exhibited the highest lethal activity against Anopheles gambiae larvae at 48 hour duration of exposure. Results showed that concentration of bacterial isolates and duration of exposure of larvae to the bacterial isolates, determine the mortality rate of larvae. Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) revealed variable bands between B. thuringiensis and M. sedentarius, which might have accounted for their differences in larvicidal activity. The use of bacteria for the control of mosquito larvae is highly recommended. Further research should be conducted to search for more bacteria and possibly fungi which have potentials for larvicidal activity.