Exploring the Antibacterial Activity of Zinc Oxide Nanoparticles against Some Selected Gram-Positive and Gram-Negative Bacteria

Increase in microbial resistance of commonly used antibiotics is a major health concern globally this has necessitated researchers to focus on cheaper alternative materials which could perform the role of antibiotics. This study aimed at investigating the synthesis of zinc oxide nanoparticles (ZnO Nps) and exploring the synthesized nanoparticles as sources of antimicrobials. The antimicrobial activity of the synthesized zinc oxide nanoparticles was tested against ten different bacteria namely; Enterobacter agglumerans, Corynebacterium bovis, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Micrococcus luteus, Klebsiella pneumoniae, Bacillus subtilis, Staphylococcus aureus, and Bacillus cereus. The results from this study revealed that four out of the test organisms (S. aureus, B. cereus, E. coli and Bacillus subtilis) were susceptible to the ZnO nanoparticles. The diameter of the zones of inhibition (ZOI) ranging from 14.50 – 25.50 mm. The synthesized nanoparticles showed the highest activity with S. aureus (ZOI = 25.50 mm, followed by B. cereus (22.00 mm), E. coli and B. subtilis (14.50 mm). The minimum inhibitory concentration (MIC) results showed that ZnO NPs was most effective against S. aureus and B. cereus at 25% concentration while minimum bactericidal concentration (MBC) was at 50%. These findings revealed that zinc oxide nanoparticles have great potentials for inhibiting clinical isolates; thus, their use as an alternative means for new drug discovery should be encouraged.