外排泵抑制剂对泛耐药鲍曼不动杆菌生物被膜的影响

Effect of Efflux Pump Inhibitor on the Biofilm of Extensively Drug Resistant Acinetobacter Baumannii

目的了解泛耐药鲍曼不动杆菌(XDR AB)生物被膜形成与外排泵基因表达的关系,比较4种外排泵抑制剂对泛耐药鲍曼不动杆菌生物被膜的作用。方法1)微量肉汤稀释法测定4种外排泵抑制剂(EPIs)PAβN、奥美拉唑、维拉帕米、CCCP对9株泛耐药鲍曼不动杆菌的最低抑菌浓度(MIC);并分别测定9株XDR AB生物被膜形成前后对17种抗菌药物的耐药性变化情况。2)结晶紫染色法测定4种外排泵抑制剂对9株XDR AB生物被膜形成的影响。3)实时定量聚合酶链反应(qRT-PCR)测定9株XDR AB浮游状态与生物被膜状态下外排泵基因adeB、adeG、adeJ的表达情况。结果9株XDR AB除对替加环素、多黏菌素B敏感外,对其余抗菌药物均不同程度耐药。生物被膜状态比浮游状态的XDR AB对于抗菌药物的耐药性进一步增加(1~32倍)。4种EPIs均能够抑制XDR AB生物被膜的形成,以PAβN的抑制作用最强(P<0.05)。在生物被膜态下,9株XDR AB的外排泵基因adeB和adeJ的表达量与浮游状态adeB和adeJ的表达量比较明显增加(P<0.05)。结论XDR AB生物被膜状态比浮游状态耐药性进一步增强与部分外排泵基因的高表达相关;4种EPIs对XDR AB生物被膜的形成具有抑制作用。

Objective To investigate the relationship between the biofilm formation of extensively drug resistant Acinetobacter baumannii(XDR AB)and efflux pump gene expression,and to compare the effects of four efflux pump inhibitors(EPIs)on the biofilm of XDR AB.Methods 1)Broth microdilution method was used to determine the minimum inhibitory concentration(MIC)of four EPIs,namely,PAβN,omeprazole,verapamil,and CCCP,against 9 strains of XDR AB.The changes of the resistance of 9 strains of XDR AB to 17 antibiotics before and after the formation of biofilm were determined.2)Crystal violet staining method was used to determine the effect of four EPIs on the biofilm formation of 9 strains of XDR AB.3)Real-time quantitative polymerase chain reaction(qRT-PCR)was used to determine the expression of efflux pump genes adeB,adeG,and adeJ in 9 strains of XDR AB in planktonic state and biofilm state.Results The 9 strains of XDR AB were sensitive only to tigecycline and polymyxin B,while they were resistant to other antibiotics to different degrees.The antimicrobial resistance of XDR AB in biofilm state was higher(1-32 times)than that in planktonic state.All EPIs could inhibit the formation of XDR AB biofilm,with PAβN showing the strongest inhibitory effect(P<0.05).The expression levels of the efflux pump genes adeB and adeJ of the 9 strains of XDR AB in biofilm state were significantly higher than those in planktonic state.Conclusion XDR AB is more resistant in biofilm state than in planktonic state,which is related to the high expression of some efflux pump genes.Four EPIs can inhibit the formation of XDR AB biofilm.