Bacteriocin-Mediated Silver Nanoconjugate: Synthesis, Characterization, and Application as an Antibiofilm Agent...

Antibiotic resistance is generated due to rampant misuse of antibiotics, and almost 80% of persistent and hard-to-treat disease-causing bacteria are difficult to treat with antibiotics because of the presence of biofilm. Hence, a different approach must be implemented in such a way that these biofilm-forming recalcitrant infectious agents can be treated without causing antibiotic resistance to develop. Bacteriocins from lactic acid bacteria, although they offer a safer therapeutic option but are limited by their narrow antimicrobial scope and the need for high doses. To address these constraints, this study focused on synthesizing bacteriocin-capped nanoparticles and evaluating their antibiofilm activities. A purified bacteriocin extracted from a strain of Enterococcus faecalis BDR22 was used for biogenic synthesis of silver nanoparticles (AgNPs). The efficacies of the biogenic nanoparticle (Bac-AgNP) against two nosocomial disease-causing bacteria, Pseudomonas aeruginosa ATCC 10145 and Staphylococcus aureus ATCC 23235, were evaluated, which indicated a significant reduction in bacterial biofilm 81.82667 ± 0.03163% (S. aureus) and 78.43 ± 0.03796% (P. aeruginosa) at a concentration of 1.7 μg/mL. It has the ability to disrupt the EPS matrix within the bacterial biofilm, which was further confirmed through SEM and FTIR analyses. The flow cytometric analysis clearly depicts the intracellular ROS generation and death of bacterial cells after treatment with Bac-AgNP. This synthesized nanoparticle was found as non-cytotoxic against the HaCat cell line, approving the candidacy of these particles as an effective therapeutic strategy to treat nosocomial infections.