Antibacterial and Anti-biofilm Activity of Three Phenolic Plant Extracts and Silver Nanoparticles on Staphylococcus aureus and Klebsiella pneumoniae

Abstract

Background: Multi-drug resistance is a growing problem in the treatment of infectious diseases and the widespread use of broad-spectrum antibiotics has produced antibiotic resistance for many human bacterial pathogens. Advances in nanotechnology have opened new horizons in Nano medicine, allowing the synthesis of nanoparticles that can be assembled into complex architectures. Method: Novel studies were carried out to assess the antibacterial effect of phenolic plants extracts and silver nanoparticles on the development of biofilm formation of bacterial species (Klebsiella pneumoniae) and (Staphylococcus aureus) using fourteen isolates from both clinical and environmental samples. Also, the experiments were conducted to study the antibacterial effect by determining the minimum inhibitory concentrations (MICs), and susceptibility test of these strains for 8 antibiotics. Moreover, the study used silver nanoparticles Ag-NPs which indicated a size range of 101.77 nm as antimicrobial agent. Although the Zingiber officinal Roscoe, Thymus vulgaris L. and Cinnamomum zeylanicum phenolic plant extracts concentrations (50, 25, 12.5, 6.25, 3.125 and 1.625 µg/ml) (W/V) were used through antibiotic and biofilm inhibition assay. Result: The result showed that the isolates behaved differently in their sensitivity to the different extracts added to their growth medium. Among the different plant phenolic extracts tested, Z. officinale showed antibiofilm efficacy against k. pneumoniae and S. aureus followed by T. vulgaris and C. zeylanicum extracts exhibited. Conclusion: The silver nanoparticles with either the plants extract compound (phenolic compound) may provide a safe and highly effective alternative to commonly used antibiotics, which are ineffective towards the antibiotic-resistant S. aureus and K. pneumonia .Also, The silver nanoparticles presented strong antimicrobial and antibiofilm activity against and K. pneumoniae and S. aureus in an indication that represents a new potential candidate for alternative antibiofilm.