Bactericidal potentials of silver and gold nanoparticles stabilized with cefixime: a strategy against antibiotic-resistant bacteria

The rapid increase in antibacterial resistance of pathogenic bacteria poses a key threat to human health. This has triggered initiatives worldwide to discover more potent antimicrobial agents. Hence, cefixime was conjugated to gold and silver nanoparticles (NPs) and resultant nano-conjugates (Cfm-AuNPs and Cfm-AgNPs) were evaluated against Staphylococcus aureus (S. aureus) ATCC 25923. The synthesized nano-conjugates were characterized by using UV–visible, IR spectroscopy, and atomic force microscopy (AFM). The bactericidal potential of Cfm-AuNPs and Cfm-AgNPs was compared with the efficacy of non-conjugated cefixime served as control. Experimentally obtained results confirmed that the bactericidal potential of cefixime was enhanced by 8 and 3 times upon conjugation with gold and silver NPs respectively. Moreover, the improved antibacterial activity and kinetics of the conjugated cefixime were observed under AFM. Surface topography analysis of the controlled and treated S. aureus cells revealed that effective treatment time (8 h) of cefixime also gets reduced to one-half(4 h) upon conjugation with both gold and silver NPs. Furthermore, the toxicity assay demonstrated that the cytocompatibility of gold and silver NPs was improved by conjugation with cefixime. Consequently, Cfm-AuNPs and Cfm-AgNPs offer the technical benefits of improved bactericidal effects of cefixime at lower dosages and serve to overcome antibiotic resistance in bacteria.