Molecular characterization of Aedes aegypti (L.), its bacterial microbiomes and their control in Saudi Arabia

Abstract

Aim: This study aims to identify laboratory strains of Aedes aegypti at a molecular level and isolate bacteria from various developmental stages, while also assessing the effectiveness of environmentally friendly Bacillus subtilis compared to a commercial insecticide (Bacilod 5000 IU) containing Bacillus thuringiensis against the 4th larval stage of Ae. aegypti. Methodology: The molecular analysis revealed a new strain of Ae. aegypti and identified 24 bacterial strains from 9 distinct families. These novel strains were documented and deposited in the GenBank for future reference. Notably, in this study B. subtilis at different concentrations (1000, 3000, 5000, 7000 and 9000 ppm) was compared with Bacilod 5000 IU (0.1, 0.3, 0.5, 0.8 and 1 ppm). Results: The mortality rate of 4th instar larvae ranged from 12 to 93% for strains treated with the isolated bacteria B. subtilis and 14 to 92% for strains treated with the commercial insecticide B. thuringiensis IU. In comparison to B. subtilis, the commercial insecticide B. thuringiensis showed an approximate 8939.91 times higher relative resistance index. Interpretation: The results obtained in this study highlights the need for further research into isolated bacteria as potential biological controls for Ae. aegypti. Key words: Aedes aegypti, Bacillus subtilis, Biological control, Insecticides, Microbiomes