Background: Staphylococcus aureus is an opportunistic pathogen that plays a role in hospital infections. Due to the ability of this bacteria to produce biofilm, its antibiotic resistance has increased. Silver nanoparticles (AgNPs), due to their small size, can penetrate bacterial cells and destroy the bacterial biofilm. The present study aimed to investigate the anti-biofilm effect of AgNPs and gentamicin on clinical Staphylococcus aureus.
Materials and Methods: Staphylococcus aureus isolates were collected from health centers in Kerman, Iran, and identified by biochemical tests. The antibiotic resistance of the isolates was evaluated against antibiotics, and then, the minimum inhibitory concentration (MIC) of the isolates was assessed by gentamicin and AgNPs. Bacterial isolates were exposed to 2 MIC, 1 MIC, ½ MIC, and ¼ MIC of gentamicin and AgNPs separately, and the results were compared.
Results: The 100% resistance of isolates to oxacillin and penicillin antibiotics was observed, and the resistance percentages 63.33%, 6.66%, and 3.33% to tetracycline, ciprofloxacin and gentamicin, respectively, were confirmed. The MIC of the isolates was from 64 μg/ml to 32 μg/ml against gentamicin, and it was from 10.62 ppm to 5.31 ppm against AgNPs. Comparing the anti-biofilm effect of AgNPs and gentamicin at 1 MIC, ½ MIC, and ¼ MIC, there was a significant difference at the 5% probability level, and the anti-biofilm effect of AgNPs was better than gentamicin.
Conclusion: According to the obtained results, it is suggested that AgNPs be used to control and destroy the biofilms formed by Staphylococcus aureus with further research.
