阿米卡星诱导对大肠埃希氏菌耐药性及生物被膜和外排泵活性的影响  

Effects of Amikacin Induction on Drug Resistance,Biofilm Formation and Efflux Pump Activity of Escherichia coli

作　　者：李苗苗 赵恒 陶梦珂 张鲁星 石晴晴 胡功政[1] 贺丹丹 刘建华[1] LI Miao-miao;ZHAO Heng;TAO Meng-ke;ZHANG Lu-xing;SHI Qing-qing;HU Gong-zheng;HE Dan-dan;LIU Jian-hua(Henan Agricultural University,Zhengzhou,Henan,450000,China)

机构地区：[1]河南农业大学,河南郑州450000

出　　处：《动物医学进展》2024年第6期83-89,共7页Progress In Veterinary Medicine

基　　金：国家自然科学基金面上项目(32072914);河南省重点研发项目(221111111300)。

摘　　要：为研究亚抑菌浓度阿米卡星诱导对大肠埃希氏菌敏感菌株耐药性、生物被膜形成能力及外排泵活性的影响,采用微量肉汤稀释法测定阿米卡星对6株菌株的最小抑菌浓度(MIC),并以0.5 MIC作为初始诱导浓度进行诱导,每隔5 d重新测定阿米卡星MIC,并调整诱导浓度,共计30 d,最后将诱导第30天菌株进行无药物压力稳定培养5 d,保存各诱导菌株及无药传代菌株共计210株,测定各诱导菌株药物敏感性、生物被膜形成能力及部分菌株外排泵活性变化。结果发现,随着诱导天数的增加,阿米卡星对6株分离菌株MIC逐渐升高,诱导菌株耐药性不断增强,其对诱导第30天菌株的MIC值为诱导前的8~32倍;经过5 d无药培养后,MIC测定结果与第30天基本保持一致;诱导后的菌株中,强成膜能力菌株占总数的5%,中成膜能力菌株为56.7%;以每5 d的生物被膜形成量平均值与原菌相比,结果发现,所有诱导菌株生物被膜形成量均显著增加(P<0.01),表明亚抑菌浓度阿米卡星诱导可促进大肠埃希氏菌生物被膜的形成;无药稳定培养5 d的菌株与诱导第30天菌株相比,生物被膜形成能力基本保持不变。荧光探针测定外排泵结果显示,诱导菌株外排泵活性显著受到抑制。以上研究结果表明,阿米卡星诱导促进菌株生物被膜的形成,抑制外排泵活性,使菌株的耐药性增强,研究结果可为氨基糖苷类药物用药提供理论依据。To investigate the impact of amikacin induction on drug resistance,biofilm formation and efflux pump activity in sensitive strains of E.coli,the microbroth dilution method was utilized to determine the minimum inhibitory concentration(MIC)of amikacin against six strains,and an initial induced concentration of 0.5 MIC was employed.The MIC value of amikacin was determined at 5-day intervals,and the drug induction concentration was adjusted over a period of 30 days.Finally,the induced strains were cultured without drugs for 5 days on day 30.A total of 210 strains,including induced and drug-free ones were preserved,and subjected to drug sensitivity testing,biofilm formation ability was determined using crystal violet staining,while the efflux pumping activity of some strains was determined by fluorescent probe analysis.The result showed that,with the prolongation of induction duration,the MIC of amikacin against 6 isolates increased,leading to enhanced resistance in induced strains.The MIC value of strain 30 d was 8-32 fold higher than that before induction.After a drug-free culture for 5 days,the MIC results were consistent with those on day 30.In the amikacin-induced strains,5%of the total induced strains exhibited a strong capacity for biofilm forming,while 56.7%displayed a medium capacity.The mean biofilm formation per five days was compared to that of the original bacteria and results indicated a significant increase(P<0.01)in biofilm formation among all induced strains,suggesting that amikacin promotes clinical Escherichia coli biofilm formation.The biofilm formation ability of the strain cultured for 5 days without drug remained unaltered compared to that of the strain cultured for 30 days.Fluorescence probe assay revealed a significant inhibition in efflux pump activity of the induced strain as opposed to the original strain.The above mentioned findings demonstrate that amikacin induces and promotes biofilm formation in strains,inhibits efflux pump activity,and enhances the drug resistance of all strains on t

关 键 词：大肠埃希氏菌 阿米卡星 诱导 生物被膜 外排泵活性 

分 类 号：S852.612[农业科学—基础兽医学] S859.796[农业科学—兽医学]