Anti-biofilm activity of TanReQing, a Traditional Chinese Medicine used for the treatment of acute pneumonia

Abstract

Aim of the study: TanReQing (TRQ) is a Traditional Chinese Medicine used to treat biofilm related upper respiratory infections. However, its anti-biofilm mechanism remains unknown. The aim of this study is to investigate the anti-biofilm activity of TRQ and to compare it with penicillin in vitro.

Materials and methods: The effect of TRQ and penicillin on free state, biofilm formation and mature biofilms of Staphylococcus aureus was studied using the crystal violet and the XTT reduction assays. Confocal Laser Scanning Microscopy was used to generate the 3D-transmission-fluorescence images of drug treated Staphylococcus aureus biofilms.

Results: The in vitro data showed that TRQ is less effective than penicillin in eradicating the planktonic bacteria. However, the anti-biofilm activity of TRQ is different from that of penicillin. TRQ not only does inhibit the formation of the Staphylococcus aureus biofilm, but also kills the viable cells embed in Staphylococcus aureus biofilm matrix.

Conclusions: This study shows for the first time that TRQ possesses an antibiotic activity against biofilm bacteria. This activity is different from that of penicillin. The evaluation system applied in this study can be utilized for identifying new anti-biofilm products from Traditional Chinese Medicine.