Molecular identification of bacteria associated with Anopheles mosquitoes for prevention and control of Malaria in the Environment

Every year, hundreds of thousands of people die of malaria in African countries especially Nigeria. Current control measures against malaria are based on drugs against the parasites (Plasmodium spp) and the vector (mosquitoes) using insecticides. Additional areas of malaria control must be explored because of the development of resistance, one of such areas involves the use of bacteria associated with the vector mosquitoes. This study investigated the molecular characterization of bacteria associated with anopheles’ mosquito for the prevention and control of malaria fever in the environment. Twenty (20) samples were collected from five different mosquito breeding places including water lodged areas, drainages, stagnant water, domestic wastes and stored rain water. Isolation of bacteria was carried out by pour plate method, identification of bacteria, mass rearing of mosquito’s larvae, larvicidal activity, optimization of the bacterial isolates for the best lavarcidal activity and molecular characterization of the isolated bacteria were carried out by standard methods. The isolated bacteria include Proteus vulgaris, Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa. Bacterial isolates with the best larvicidal activity were Staphylococcus aureus (WL3), Bacillus subtilis (S4), Pseudomonas aeruginosa (R5) and Proteus vulgaris (D1). Optimum temperature, pH and appropriate carbon source play an important role in determining the larvicidal effectiveness of bacterial isolates. Optimum temperature of 37oC and near-neutral pH conditions (6.5–7.0) were more favorable for larvicidal metabolite production while glucose and sucrose were more effective than soluble starch in enhancing larvicidal activity. The study revealed naturally occurring pathogenic bacteria associated with mosquitoes, these bacterial isolates and their metabolites may be used to reduce transmission of malaria fever by reducing population size, shorten life span and inhibit the ability of mosquitoes to transmit malaria parasites by eliminating the parasites in the vectors.