Isolation and Identification of Local Soil Bacteria with Larvicidal Activities Against Aedes aegypti Larvae

Mosquito-borne diseases caused by infected mosquitoes like dengue fever, Zika fever, Chikungunya and malaria are spread to humans through biting causing disease epidemics all over the world. This indicates the necessity for new mosquito-borne disease control strategies in Saudi Arabia and internationally. This study evaluated the potential of local bacteria isolated from the soil of the Rahat region of Makkah, Saudi Arabia for the biocontrol of Aedes aegypti larvae, a major agent for the transmission of dengue fever. Soil samples were collected from the Rahat region, Makkah for the isolation of bacteria. The bacteria were evaluated for larvicidal activity against the larvae of A. aegypti. The bacteria that show toxicity to the larvae were identified using morphological and molecular characteristics. Four different strains of the bacteria with a toxicity towards A. aegypti larvae were isolated and identified. Two of the isolates (Brevibacillus centrosporus N8 and Cytobacillus species N7) caused 100% mortality in 24 h while the other two isolates (Escherichia coli N3 and Escherichia coli N4) caused at least 70% mortality. The findings of this study revealed the larvicidal activity of soil bacteria from the Rahat region, Makkah and could be a potential candidate for the biocontrol of mosquito vectors.