目的 探讨中药黄芩不同提取部位对NDM-1乙酸钙不动杆菌的抑菌效果及质粒消除作用。方法 测定黄芩醇提剂和水煎剂对NDM-1乙酸钙不动杆菌的最小抑菌浓度(MIC);观察亚抑菌浓度下对NDM-1乙酸钙不动杆菌生长曲线的变化;利用亚抑菌浓度黄芩醇提剂和水煎剂对乙酸钙不动杆菌NDM-1质粒进行消除,用平板影印法筛选质粒消除株,并比较质粒的消除率及表型变化。结果 黄芩醇提剂对NDM-1乙酸钙不动杆菌的MIC值为1.56 mg·mL^-1,水煎剂MIC值为6.25 mg·mL^-1。生长曲线实验结果表明,醇提剂对细菌的繁殖抑制作用更强。黄芩醇提剂和水煎剂均有不同程度的质粒消除作用,以醇提剂传代消除作用更为明显,消除率最高可达61.27%,水煎剂亦能达到49.78%。结论 黄芩能够抑制NDM-1乙酸钙不动杆菌的生长并有效消除其耐药质粒,且醇提组分作用效果更佳,可用于控制超耐药不动杆菌的传播或临床感染的辅助治疗。

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 The in 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-1 Acinetobacter 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.