Antibacterial activity of bio-synthesised copper nanoparticles and synergicimpact with tetracycline

The increasing problem of antibiotic resistance, there is a need to develop effective and eco-friendly antimicrobial strategies. In the present study, copper nanoparticles (CuNPs) were synthesized through a green, fungal-mediated approach using Aspergillusniger isolated from onion peel. The biosynthesis of CuNPswere characterized using UV- Visible spectroscopy to confirm nanoparticle formation. Bacterial strains were isolated from sewage water and identified using standard morphological and biochemical tests. The antimicrobial activity of the synthesized CuNPs was evaluated against the identified bacterial isolates using well diffused method. Furthermore, the synergistic antimicrobial effect of CuNPs in combination with antibiotic tetracycline was assessed. The results demonstrated that fungal-derived CuNPsexhibited significant antimicrobial activity, which was markedly enhanced when used in combination with tetracycline, indicating a synergistic interaction. This study highlights the potential of Aspergillusniger-mediated CuNPs as effective antimicrobial agents and supports their application in combination therapy to combat antibiotic-resistant microorganism.