黄芩苷消除鲍曼不动杆菌耐药质粒的实验研究

Experimental Study of Baicalin Curing Antibiotic-Resistant Plasmid in Acinetobacter Baumanii

关键词:  黄芩苷  质粒  鲍曼不动杆菌  庆大霉素  环丙沙星

Key words:  baicalin  plasmid  Acinetobacter baumannii  gentamicin  ciprofloxacin

摘要:

目的 探讨黄芩苷能否消除鲍曼不动杆菌质粒，并影响抗菌药物对细菌的最低抑菌浓度(MIC)。方法 测定黄芩苷处理的鲍曼不动杆菌生长曲线。16株庆大霉素和环丙沙星双重耐药的鲍曼不动杆菌，经黄芩苷作用20 h，分别在处理前和处理后应用碱裂解法检测质粒，琼脂稀释法测定抗菌药物MIC。结果 黄芩苷能抑制鲍曼不动杆菌生长。16株鲍曼不动杆菌耐药株均携带质粒，经1 mg·mL^-1黄芩苷作用后，质粒消除率为37.5%(6/16)。6株经黄芩苷消除质粒的细菌，庆大霉素中度水平或低水平耐药株的MIC值均下降至敏感水平；环丙沙星低水平耐药株的MIC值下降至敏感水平，部分环丙沙星中度水平耐药株的MIC值下降但高于耐药水平。结论 黄芩苷能够消除鲍曼不动杆菌低水平耐药株携带的质粒，恢复菌株对庆大霉素和环丙沙星的敏感性，可用于鲍曼不动杆菌低水平耐药株感染辅助治疗。

Abstract:

OBJECTIVE To investigate if baicalin was able to cure antibiotic-resistant plasmid in Acinetobacter baumanii, and affect minimum inhibitory concentrations (MIC) of antibiotics to bacteria. METHODS The growth curve of A. baumanii treated with baicalin was detected. 16 strains of A. baumanii, gentamicin(GEN) and ciprofloxacin(CIP) resistance, were treated with baicalin for 20 hours. Before and after baicalin treatment, plasmids of A. baumanii were determined with alkaline lysis method, and MICs of GEN and CIP were measured by agar dilution method. RESULTS Baicalin inhibited the growth of A. baumanii. The plasmid curing rate was 37.5%(6/16) in 16 strains of A. baumanii with plasmids, after the treatment with baicalin (1 mg.mL^-1). In 6 strains of A. baumanii with plasmid cured by baicalin, for medium or low level of GEN-resistance strains, MICs of GEN all decreased to sensitive level; for low level of CIP-resistance strains, MICs of CIP all dropped to sensitive level, and for some medium-level of CIP-resistance strains, MICs of CIP also dropped, but still above the resistance level. CONCLUSION Baicalin can eliminate plasmids of A. baumanii with low level of antibiotic-resistance, and make these strains recover the susceptibility to GEN and CIP, which shows an adjuvant treatment method for antibiotic-resistant A. baumanii infections.