Pesticide-induced soil degradation is a major concern for intensive agriculture. This study assessed the impact of deltamethrin and thiophanate-methyl on the cultivable bacterial diversity of agricultural soils in northeastern Algeria. 48 bacterial strains were isolated, among which four representative species for this study —Achromobacter marplatensis EY-T10, Bacillus weihenstephanensis 261ZG8, Arthrobacter sp. dv7, and Bacillus sp. JDMASP42— were selected based on their metabolic potential. Growth assays, measured by Optical Density (OD₆₀₀), revealed distinct strain-specific responses: in the presence of deltamethrin, Bacillus strains reached a mean OD of 0.25, indicating a growth increase of 19% compared to the control. Conversely, thiophanate-methyl exerted a strong inhibitory effect, limiting the final OD to 0.059, for sensitive species, representing an important biomass reduction. Phylogenetic analysis confirmed that Bacillus and Pseudomonas were the dominant taxa among the pesticide-tolerant isolates. These quantitative results demonstrate that pesticide exposure acts as a strong ecological filter, significantly shifting the soil microbial community structure toward tolerant, spore-forming genera. This work provides critical data on the selection pressure exerted by agrochemicals on indigenous soil microflora.