Total alkaloids of Sophora alopecuroides and matrine inhibit auto-inducer 2 in the biofilms of Staphylococcus epidermidis.

Quorum sensing (QS) mediates the coordination of population-based behavior in bacteria, which is highly involved in the formation of bacterial biofilms and virulence of bacteria in vivo. Therefore, an inhibition of QS and biofilm growth is of therapeutic interest. This study exhibited the an auto-inducer molecule (AI-2) activity as the most important component of the QS system was positively correlated with the growth and biofilm formation of S. epidermidis strains. In addition, TASA and matrine have a capacity to inhibit AI-2 in three S. epidermidis strains compared to the control (p < 0.01). This result indicated TASA and matrine can also decrease AI-2 activity in the biofilm of S. epidermidis (p < 0.05). By comparison, TASA was more effective than ceftazidime and matrine to inhibit the AI-2 activity in biofilm S.epidermidis reference strain ATCC35984 (p < 0.05). This result indicated potentials of TCM compounds TASA and matrine in prevention of biofilm formation in Staphylococcus epidermidis infections.