Repurposing streptomycin and chloramphenicol against bacterial pathogens by combination with diminazene aceturate.

This article focuses on evaluating the in vitro antimicrobial efficacy and synergistic potential of diminazene aceturate (DA), chloramphenicol (CHL), and streptomycin (STP) against clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus. DA, a drug traditionally used for animal trypanosomiasis, showed inhibitory activity against all tested strains, and when combined with STP or CHL, demonstrated synergistic effects particularly against Gram-negative bacteria, as indicated by fractional inhibitory concentration indices (FICIs) ≤ 0.5. Time-kill assays confirmed that the DA and STP combination inhibited bacterial growth more rapidly at lower concentrations than monotherapies, and no hemolytic activity was observed for any antimicrobial or combination at tested concentrations. These findings suggest that repositioning DA in combination with conventional antibiotics could be a promising strategy to enhance treatment efficacy against resistant bacterial pathogens.