Influence of hybrid inorganic/organic mesoporous and nanostructured materials on the cephalosporins´ efficacy on different bacterial strains

The aim of this study was to investigate the effect of different hybrid inorganic-organic micro- and nanomaterials (Fe₃O₄/PEG₆₀₀, Fe₃O₄/C₁₂, ZSM-5) on the antibacterial activity of different cephalosporins against Gram-positive and Gram-negative bacterial strains. The synergic effect of the studied materials was demonstrated by the increase in the growth inhibition zones diameter. All tested hybrid micro- and nanomaterials increased the activity of cefotaxime against Staphylococcus aureus. ZSM-5 increased the activity of cefotaxime and ceftriaxone and Fe₃O₄/C₁₂ that of ceftriaxone against Pseudomonas aeruginosa and S. aureus. The anti-Pseudomonas, anti-Klebsiella pneumoniae and anti-Bacillus subtilis activity of cefoperazone was increased by Fe₃O₄/C₁₂ nanoparticles, while the ZSM-5 improved its anti-Escherichia coli, K. pneumoniae, S. aureus and B. subtilis activity, whereas Fe₃O₄/PEG₆₀₀ against K. pneumoniae. The anti-K. pneumoniae activity of cefepime was increased by all tested nanoparticles, whereas its anti-B. subtilis and anti-E. coli activity was improved by Fe₃O₄/C₁₂ and Fe₃O₄/PEG₆₀₀ nanoparticles. In conclusion, both magnetic Fe₃O₄ nanoparticles, charged outside as extra-shell with the antibiotic as well as ZSM-5 microparticles carrying the antibiotic inside the pores, significantly and specifically improved cephalosporin efficacy. A probable explanation for the increase in the antibiotic efficiency is the better penetration through the cellular wall of the antibiotic charged nanoparticles.