RESUMEN
The emergence of antibiotic-resistant bacteria, particularly the most hazardous pathogens, namely Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. (ESKAPE)-pathogens pose a significant threat to global health. Current antimicrobial therapies, including those targeting biofilms, have shown limited effectiveness against these superbugs. Nanoparticles, specifically silver nanoparticles (AgNPs), have emerged as a promising alternative for combating bacterial infections. In this study, two types of AgNPs with different physic-chemical properties were evaluated for their antimicrobial and antibiofilm activities against clinical ESKAPE strains. Two types of silver nanoparticles were assessed: spherical silver nanoparticles (AgNPs-1) and cubic-shaped silver nanoparticles (AgNPs-2). AgNPs-2, characterized by a cubic shape and higher surface-area-to-volume ratio, exhibited superior antimicrobial activity compared to spherical AgNPs-1. Both types of AgNPs demonstrated the ability to inhibit biofilm formation and disrupt established biofilms, leading to membrane damage and reduced viability of the bacteria. These findings highlight the potential of AgNPs as effective antibacterial agents against ESKAPE pathogens, emphasizing the importance of nanoparticle characteristics in determining their antimicrobial properties. Further research is warranted to explore the underlying mechanisms and optimize nanoparticle-based therapies for the management of infections caused by antibiotic-resistant bacteria.
RESUMEN
Bacterial biofilm formation and antibiotic resistance are the main factors of surgical wound complications. Traditional treatments in some cases cannot provide complete bacterial eradication and new therapeutic approaches should be developed to overcome antibiotic resistance. Silver nanoparticles (AgNPs) can be the first choice for bacteria treatment but their clinical application is limited due to toxic effects. Combination of AgNPs with the low-frequency ultrasound (US) treatment expected to decrease toxicity and leads to the facilitation of wound healing. In current research we investigated the antibacterial activity of AgNPs per se and in combination with low-frequency US, assessed the cytotoxicity of AgNPs on human dermal fibroblasts and finally, wound healing was evaluated in purulent wound model (96 white laboratory rats) applying AgNPs and US as a treatment strategy. Our results demonstrate no toxic effect of AgNPs in minimum inhibitory concentrations and show increasing their antibacterial effectiveness after US application. The combination of low-frequency US and AgNPs provides reduction of the inflammatory reaction, microorganism elimination and leads to facilitation of new tissue formation with complete epithelization. All effects were significant over the Chlorhexidine treatment, monotherapy with AgNPs or US. Advanced effectiveness of complex therapy opens new perspectives for clinical application of AgNPs solution accompanied by US.
