Antibacterial activity and mechanism of berberine against Streptococcus agalactiae

Int J Clin Exp Pathol. 2015 May 1;8(5):5217-23. eCollection 2015.


The antibacterial activity and mechanism of berberine against Streptococcus agalactiae were investigated in this study by analyzing the growth, morphology and protein of the S. agalactiae cells treated with berberine. The antibacterial susceptibility test result indicated minimum inhibition concentration (MIC) of berberine against Streptococcus agalactiae was 78 μg/mL and the time-kill curves showed the correlation of concentration-time. After the bacteria was exposed to 78 μg/mL berberine, the fragmentary cell membrane and cells unequal division were observed by the transmission electron microscopy (TEM), indicating the bacterial cells were severely damaged. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) study demonstrated that berberine could damage bacterial cells through destroying cellular proteins. Meanwhile, Fluorescence microscope revealed that berberine could affect the synthesis of DNA. In conclusion, these results strongly suggested that berberine may damage the structure of bacterial cell membrane and inhibit synthesis of protein and DNA, which cause Streptococcus agalactiae bacteria to die eventually.

Keywords: Berberine; SDS-PAGE; Streptococcus agalactiae; TEM; antibacterial activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / biosynthesis
  • Berberine / pharmacology*
  • Cell Membrane / drug effects
  • Cell Membrane / ultrastructure
  • DNA Replication / drug effects
  • DNA, Bacterial / biosynthesis
  • Dose-Response Relationship, Drug
  • Electrophoresis, Polyacrylamide Gel
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Microscopy, Electron, Transmission
  • Microscopy, Fluorescence
  • Protein Biosynthesis / drug effects
  • Proteomics / methods
  • Streptococcus agalactiae / drug effects*
  • Streptococcus agalactiae / genetics
  • Streptococcus agalactiae / growth & development
  • Streptococcus agalactiae / metabolism
  • Streptococcus agalactiae / ultrastructure
  • Time Factors


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • DNA, Bacterial
  • Berberine