Antimicrobial Activity of Iron Oxide Nanoparticles Stabilized by Alginate

Increase in microbial resistance of commonly used antibiotics is a major health concern globally. This study aimed at exploring the use of iron oxide nanoparticles (IONPs) stabilized by alginate as sources of antimicrobials. Antimicrobial activity of synthesized magnetic nanoparticles was tested against six organisms (Bacillus subtilis, Staphylococcus aureus, Candida albicans, Vibrio cholerae, Proteus vulgaris and Micrococcus luteus) using agar diffusion method. Results showed that IONPs exhibited a strong antimicrobial activity against most of the tested clinical isolates. M. luteus had highest antimicrobial activity (21 mm), followed by B. subtilis (20 mm), S. aureus (20 mm) and V. cholerae (20 mm) while P. vulgaris and C. albicans had intermediate activities against IONPs. The minimum inhibitory concentration (MIC) results showed that IONPs was most effective against B. subtilis and S. aureus, followed by M. luteus and least activity was noticed against V. cholerae. Also, minimum bactericidal concentration (MBC) result revealed that IONPs had MBC of 40 mg/ml against both B. subtilis and S. aureus, and 60 mg/ml against M. luteus and V. cholerae. These findings revealed that alginate stabilized IONPs have great potentials for inhibiting clinical isolates; thus, their use as an alternative means for new drug discovery should be encouraged.