Piperine, a Plant Alkaloid, Exhibits Efficient Disintegration of the Pre-existing Biofilm of Staphylococcus aureus: a Step Towards Effective Management of Biofilm Threats.

Staphylococcus aureus causes a range of chronic infections in humans by exploiting its biofilm machinery and drug-tolerance property. Although several strategies have been proposed to eradicate biofilm-linked issues, here, we have explored whether piperine, a bioactive plant alkaloid, can disintegrate an already existing Staphylococcal biofilm. Towards this direction, the cells of S. aureus were allowed to develop biofilm first followed by treatment with the test concentrations (8 and 16 µg/mL) of piperine. In this connection, several assays such as total protein recovery assay, crystal violet assay, extracellular polymeric substances (EPS) measurement assay, fluorescein diacetate hydrolysis assay, and fluorescence microscopic image analysis confirmed the biofilm-disintegrating property of piperine against S. aureus. Piperine reduced the cellular auto-aggregation by decreasing the cell surface hydrophobicity. On further investigation, we observed that piperine could down regulate the dltA gene expression that might reduce the cell surface hydrophobicity of S. aureus. It was also observed that the piperine-induced accumulation of reactive oxygen species (ROS) could enhance biofilm disintegration by decreasing the cell surface hydrophobicity of the test organism. Together, all the observations suggested that piperine could be used as a potential molecule for the effective management of the pre-existing biofilm of S. aureus.