Larvicidal activities of local bacteria against Aedes aegypti larvae

Since the beginning, mosquito-borne diseases like dengue fever, encephalitis, yellow fever, malaria, and filariasis have been caused by numerous medically significant pathogens and parasites, including viruses, bacteria, and protozoans. This indicates the necessity for the ongoing creation of new and effective mosquito-borne disease control strategies in Saudi Arabia and internationally. This investigation has tried to assess the potential larvicidal capacity of local bacteria isolated from the soil of the Rahat region of Makkah, Saudi Arabia for the bio-control of Aedes aegypti larvae, a main cause of dengue. The bacteria were identified using morphological and molecular characteristics. Bioassays were used to determine the pathogenicity of various strains against A. aegypti larvae. A total of 66 different bacteria were isolated. Overall, four (6.06%) of the 66 bacteria caused mortality in the A. aegypti larvae, and only two (Brevibacillus centrosporus, and Cytobacillus firmus) caused 100% mortality in 24 h. After 48 h, two isolates (Escherichia fergusonii1 and E. fergusonii 2) caused mortality of over 70%. The outcomes of this investigation exhibited that local isolates of bacteria in the soils of the Rahat region of Makkah, Saudi Arabia, have larvicidal ability. These bacteria have shown larvicidal effects on the larvae of A. aegypti. In conclusion, further studies are required to evaluate other mechanisms that contribute to the production of larvicidal toxins in these bacteria.