对密度感知信号系统在 MRSA 菌株感染及红霉素干预作用的观察  

Effect of quorum sensing system on the infection of MRSA and the intervention of erythromycin on it

作　　者：史华英[1] 李青栋[1] 万献尧[1] 

机构地区：[1]大连医科大学附属第一医院重症医学科重症医学研究所,116011

出　　处：《中华医学杂志》2016年第37期3014-3019,共6页National Medical Journal of China

摘　　要：目的：探究红霉素对生物膜的破坏作用及红霉素对密度感知信号（QS）系统相关因子的影响。方法检测红霉素对 MRSA 菌株的最低杀菌浓度（MBC）。构建生物膜模型，24 h 予红霉素干预后6、12、24、48、72 h 及7 d 时检测生物膜，并取菌液上清液及大鼠血清检测自分泌诱导肽（AIP）。结果红霉素对 MRSA 的 MBC 为256 g／L。予红霉素或胰蛋白胨大豆肉汤培养基（TSB）后生物膜先减少后增加，干预后12、24、48 h 实验组生物膜量（1．348、1．236、1．667）明显少于对照组（1．789、1．712、2．349），P ＜0．05。红霉素直接作用于成熟生物膜，使后者逐渐减少乃至完全消散。细菌接种后不同时间予红霉素干预，只有3 h 之内干预可有效杀菌，且无生物膜形成。自分泌诱导肽（AIP）的发展趋势相似于并且早于生物膜的发展趋势。予红霉素或 TSB 干预后6、24、48 h 实验组 AIP （0．8915、0．8539、0．7924）明显少于对照组（1．0237、1．0616、1．0347），P ＜0．05。结论未形成生物膜时予红霉素干预可有效杀菌；生物膜形成后，红霉素可破坏已形成的生物膜。 AIP 是促进生物膜形成的重要因素。红霉素对 AIP 的合成分泌有一定的抑制作用。Objective To investigate the destructive effects of erythromycin on biofilm of MRSA and find the effect of erythromycin on QS related factors.Methods Tested the MBC of erythromycin on MRSA.Established the model of biofilm.Erythromycin was added into the medium when bacteria were inoculated for 24 h.Tested the biofilm and collected the supernatant or serum of rat at 6, 12, 24, 48, 72 h and 7 d after adding erythromycin to detect the concentration of autoinducing peptides （AIP）.Results The MBC of the erythromycin on standard strains of MRSA was 256 g/L.There is a decreasing tendency of biofilm in a short time after adding erythromycin or TSB and then gradually increase until to a steady state.Biofilm of experimental group（1.348, 1.236, 1.667）were significantly less than the control group（1.789, 1.712, 2.349,P 〈0.05） at 12, 24, 48 h.Adding erythromycin to the mature biofilm, there was a significant decrease of biofilm.Adding erythromycin within 3 hours after inoculating bacteria, there was no bacterial growth or biofilm formation.The development trend of AIP was similar with biofilm and AIP happened earlier than biofilm.With the intervention of erythromycin, AIP of experimental group （ 0.891 5, 0.853 9, 0.792 4）were significantly less than the control group（1.023 7, 1.061 6, 1.034 7,P 〈0.05）at 6, 24, 48 h. Conclusion Adding erythromycin timely before biofilm formation, then bacteria were killed effectively.Erythromycin was able to destroy biofilm.Biofilm was inhibited by AIP obviously.To some extent, erythromycin can inhibit the synthesis or secretion of AIP.

关 键 词：葡萄球菌 金黄色 甲氧西林抗药性 自身分泌信号交流 生物膜 红霉素 

分 类 号：R515[医药卫生—内科学]