Antibacterial Effects Of Berberine On Antibiotic-Resistant Staphylococcus Aureus

ABSTRACT

Antibiotic-resistant Staphylococcus aureus (S. aureus )emerged in many parts of the world and increased complex clinical problems.Therefore,new agents are needed to treat the antibiotic-resistant S. aureus .Some natural products are candidates of new antibiotic substances.Previous reports showed that the extract of Coptidis Rhizoma and Phellodendri Cortex have antimicrobial effects.The main antibacterial substance of Coptidis Rhizoma and Phellodendri Cortex is berberine.In this study,we examined the antimicrobial activity of berberine to antibiotic-resistant S. aureus.We isolated the 13 strains of antibiotic-resistant S. aureus from the oral cavity of healthy children in a preschool,and investigated the antimicrobial activity of berberine.We examined the effects of berberine on the level of resistance to antibiotic-resistant S. aureus .We observed that the invasion of S. aureus into human gingival fibroblasts was blocked by berberine.Berberine inhibited the growth of antibiotic-resistant S. aureus as a dose dependent maner.Minimum inhibitory concentration (MIC)of berberine against antibiotic-resistant S. aureus was 50~100micro gram/ml.The inhibition of S. aureus invasion was depended on the concentration of berberine in human gingival fibroblasts.The MIC of ampicillin against antibiotic-resistant S. aureus was 32micro gram/ml.However,the MIC of ampicillin against antibiotic-resistant S. aureus in the presence of 50micro gram/ml berberine was 1micro gram/ml.These data indicate that the combination with berberine and beta -lactam antibiotics resulted in the synergistic reaction.These results suggest that the berberine may have the antimicrobial activities to antibiotic-resistant S. aureus,and the mechanism may be the inhibition of growth and intracellular invasion,and alteration of antibiotic-resistance level of antibioticresistant S. aureus.