壳聚糖修饰多黏菌素B脂质体联合超声微泡对生物膜态鲍曼不动杆菌协同抗菌作用

Synergetic Antibacterial Effect of Ultrasound Microbubbles Combined with Chitosan-Modified Polymyxin B Liposomes on Biofilm-producing Acinetobacter baumannii

目的探讨壳聚糖修饰的多黏菌素B脂质体联合超声微泡对生物膜态鲍曼不动杆菌(AB)的体外协同抗菌作用。方法采用注入法制备壳聚糖修饰的多黏菌素B脂质体(c-PMB-Lip),检测不同多黏菌素B制剂对临床分离AB的最小生物膜抑菌浓度(MBIC);进一步探讨壳聚糖修饰的多黏菌素B脂质体组(c-PMB-Lip)、超声微泡+多黏菌素B组(USMB+PMB)、超声微泡+壳聚糖修饰的多黏菌素B脂质体组(USMB+c-PMB-Lip)对生物膜态AB的抗菌作用,并分析其抗菌效应的量效关系。结果 c-PMB-Lip对生物膜态AB的MBIC为(8.0±2.0)μg·mL^(-1);超声微泡能增强抗菌药物多黏菌素B对生物膜态AB的抑制作用;而超声微泡联合脂质体制剂可得到更为显著的抗生物膜态AB效应,甚至可以完全清除生物膜态AB;各组随着药物浓度的增加,在一定范围内与其抗菌作用呈现量效关系;同无菌空白对照组相比,USMB+c-PMB-Lip在2μg·mL^(-1)时几乎能够完全清除细菌生物膜并达到最大抗菌效应(P>0.05)。结论壳聚糖修饰的多黏菌素B脂质体联合超声微泡对生物膜态AB具有显著的协同抗菌作用。

OBJECTIVE To investigate the synergetic antibacterial effects of chitosan-modified polymyxin B liposomes （c-PMB-Lip） combined with ultrasound microbubbles on biofilm-producing Acinetobacter baumannii（AB） in vitro. METHODS c-PMB-Lip was prepared by an injection method. The minimum biofilm inhibition concentrations （MBIC） of the AB clinical isolates treated with different preparations of polymyxin B were determined. The antibacterial effects and the dose-effect relationship of ehitosan-modified polymyxin B liposome group （c-PMB-Lip） , ultrasound mierobubble ＋ polymyxin B group （ USMB ＋ PMB） and ultrasound microbubble ＋ chitosan modified polymyxin B liposome group （USMB ＋ c-PMB-Lip） were further revealed. RESULTS The MBIC of c-PMB-Lip was （ 8.0 ±2.0） μg · mL^-1 against biofilm-producing AB. USMB could enhance the inhibitory effects of polymyxin B on biofilm-produeing AB. Moreover, USMB combined with lipid agents could obtain the most significant inhibitory effects and even completely remove the biofilm-producing AB. With the drug concentration increasing, the antibacterial effects of each group showed a dose-effect relationship within a certain range. Compared with the sterile blank group, USMB ＋ c-PMB-Lip could completely remove the bacterial biofilm and achieve a maximum antibacterial effects at 2 μg · mL^-1 （P 〉 0.05）. CONCLUSION c-PMB-Lip combined with USMB have significant synergistic antibacterial effect on biofilm-producing AB.