多黏菌素B联合褪黑素对多黏菌素B耐药鲍曼不动杆菌的体外抗菌活性  

In vitro antimicrobial activity of polymyxin B combined with melatonin against polymyxin B-resistant Acinetobacter baumannii

作　　者：赵玉杰 吴巧萍 冯络珠 刘亿 秦玲 ZHAO Yujie;WU Qiaoping;FENG Luozhu;LIU Yi;QIN Ling(The Affiliated Li Huili Hospital of Ningbo University,Ningbo,Zhejiang 315040,China;不详)

机构地区：[1]宁波大学附属李惠利医院检验科,浙江宁波315040 [2]宁波大学附属第一医院检验科,浙江宁波315000

出　　处：《中华医院感染学杂志》2025年第6期834-839,共6页Chinese Journal of Nosocomiology

基　　金：浙江省医药卫生科技计划基金资助项目(2023KY245);宁波大学附属李惠利医院“惠利基金”科研基金资助项目(2022FZ001)。

摘　　要：目的研究体外诱导多黏菌素B耐药鲍曼不动杆菌的耐药机制,并探究多黏菌素B联合褪黑素对其的体外杀菌活性。方法采用体外诱导方法将宁波大学附属李惠利医院2021年1月-2021年12月临床分离的10株多黏菌素B敏感鲍曼不动杆菌诱导成多黏菌素B耐药株;聚合酶链反应(PCR)法联合测序分析探究鲍曼不动杆菌对多黏菌素B的耐药机制;微量棋盘稀释法检测多黏菌素B与褪黑素单用及联用对多黏菌素B耐药鲍曼不动杆菌的最小抑菌浓度(MIC),并通过计算部分抑菌浓度指数(FICI)评价多黏菌素B与褪黑素的联合抑菌效果,选取联合抗菌活性表现为明显协同效应的菌株测定其时间杀菌曲线。结果在多黏菌素B诱导耐药的鲍曼不动杆菌中,多黏菌素耐药基因pmrB、lpxA和lpxD均出现不同位点的基因突变;多黏菌素B和褪黑素联合用药后,鲍曼不动杆菌对多黏菌素B的MIC值下降,两种药物的联合抗菌活性表现为协同作用的占80.00%(8/10),相加作用的占20.00%(2/10);时间杀菌曲线显示多黏菌素B和褪黑素联用在24 h时呈现显著的杀菌效应。结论染色体介导的耐药基因突变是本研究鲍曼不动杆菌对多黏菌素B耐药的主要机制。多黏菌素B与褪黑素联用可逆转鲍曼不动杆菌对多黏菌素B的耐药性。OBJECTIVE To observe the in vitro induced drug resistance mechanisms of polymyxin B-resistant Acinetobacter baumannii and explore the in vitro antimicrobial activity of polymyxin B combined with melatonin.METHODS Totally 10 strains of polymyxin B-sensitive A.baumannii were clinically isolated from the Affiliated Li Huili Hospital of Ningbo university between Jan.2021 to Dec.2021 and were induced to the polymyxin B-resistant strains by means of in vitro induction method.The drug resistance mechanisms of the polymyxin B-resistant A.baumannii strains were explored by polymerase chain reaction(PCR)combined with sequencing analysis.The minimum inhibitory concentrations(MICs)of the single and joint use of polymyxin B and melatonin were detected by using broth microdilution checkerboard.The antibacterial effect of polymyxin combined with melatonin was evaluated by calculating fractional inhibitory concentration index(FICI).The strains that showed the remarkable synergistic effect for the antimicrobial activity were chosen to determine the time-kill curves.RESULTS Among the polymyxin B-induced drug-resistant A.baumannii strains,there were gene mutations at various loci of polymyxin resistance genes pmrB,lpxA and lpxD.The MIC of polymyxin B against A.baumannii strains declined after the combined use of polymyxin B and melatonin.The combined use of the two drugs that showed synergistic effect for antimicrobial activity accounted for 80.00%(8/10),the additive effect 20.00%(2/10).The time-kill curve showed that the combined use of polymyxin B and melatonin showed remarkable antibacterial effect at the 24th hour.CONCLUSIONS The drug resistance gene mutations that are mediated by chromosomes are the major drug resistance mechanisms of the A.baumannii strains to polymyxin B.The combined use of polymyxin B and melatonin may reverse the drug resistance of the A.baumannii to polymyxin B.

关 键 词：多黏菌素B 褪黑素 鲍曼不动杆菌 耐药机制 

分 类 号：R378.99[医药卫生—病原生物学]