Insights of Bacterial Biofilm Suppression by Cucurbita moschata Seed‐Mediated ZnO Nanorods

Biogenically synthesized ZnO nanorods using Cucurbita moschata seed have demonstrated significant antibiofilm activity against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. Building on our previous findings, the current study extends to investigate the interactions of the nanorods during the pre- and postbiofilm formations. The pre-biofilm investigations include monitoring the changes in cellular zeta potential and hydrophobicity upon nanorod treatment. The post-biofilm assessments focus on the inhibition of cellular revival, extracellular polymeric substance components, and vital virulence factors-staphyloxanthin and pyocyanin; loss of cellular viability and biofilm architecture; and loss of cellular integrity and observation of the alterations in the pH of biofilm cultured media. Notably, the cellular hydrophobicity decreases to 5% and 17% for S. aureus and P. aeruginosa, respectively, at 250 μg/mL. Meanwhile, staphyloxanthin was inhibited by 48.49% ± 1.3% (250 μg/mL), and pyocyanin reduction hit a dose-dependent plateau at 500 μg/mL with 89.78% ± 0.47%. Further propositions on the strain-specific mechanistic insights by evaluating the relative mode of interaction with the green-synthesized ZnO nanorods have been discussed. Interestingly, the antibacterial modes of action by 1D-biogenic ZnO nanorods offer a novel approach and insight into the use of eco-friendly resources for an integrated approach towards antibiofilm strategies.