Antibacterial and NDM-1 Plasmid Elimination Effects of Radix Scutellariae Baicalensis on Acinetobacter calcoaceticus / 中国药学杂志

ABSTRACT

OBJECTIVE: To explore the bacteriostasis and plasmid elimination activities of different extracted parts of traditional Chinese medicine Radix Scutellariae Baicalensis on NDM-1 Acinetobacter calcoaceticus. METHODS: Thein vitro antibacterial effect of the extracts from Radix Scutellariae Baicalensis was studied. Inhibition zone and minimum inhibitory concentration(MIC) of the alcohol extract and water decoction were examined by using MH agar plates and microdilution susceptibility testing. The growth curve of the NDM-1 Acinetobacter calcoaceticus was tested after being incubated with alcohol extract and water decoction at sub-MIC. At three time points after incubation with different extracts at sub-MIC, photocopy dish method was used to screen plasmid-cured strains of NDM-1 Acinetobacter calcoaceticus. The plasmid-elimination rates and phenotypic changes were compared. RESULTS: Both the alcohol extract and water decoction of Radix Scutellariae Baicalensis inhibited the growth of NDM-1 Acinetobacter calcoaceticus. The MICs were 1.56 mg·mL-1 for the alcohol extract and 6.25 mg·mL-1 for the water decoction. The growth curve showed that the antibacterial effect of the alcohol extract was more obvious. Both the alcohol extract and water decoction of Radix Scutellariae Baicalensis had some degrees of plasmid elimination effect. The plasmid-elimination rates in the alcohol extract group were higher than those in the water decoction group. The plasmid-elimination rates were 61.27% for the alcohol extract and 49.78% for the water decoction, respectively. CONCLUSION: Radix Scutellariae Baicalensis can inhibit the growth of NDM-1Acinetobacter calcoaceticus and eliminate the drug-resistant plasmid effectively and has the potential to be used to control the spread of pan-drug resistant Acinetobacter strains or be an adjuvant treatment method for clinical infections. Its alcohol extract has better effect.