摘要目的 探讨肾上腺素( EPI)对生物材料表面大肠埃希氏菌 qseC 缺陷株生物被膜形成的影响.方法 以大肠杆菌MC1000、MC1000△qseC为实验菌株,对两菌株在不同培养基(LB或LBEPI)中的运动能力进行比较;同时分别将两菌株和PVC材料片在不同培养基(LB或LB+EPI)中培养,用激光共聚焦显微镜(CLSM)和扫描电镜(SEM)观察EPI对PVC表面细菌生物被膜形成的影响.结果 在LB培养基中,qseC缺陷株的细菌生物被膜形成能力较野生菌株明显减弱(P＜0.05).MC1000菌株在LBEPI培养基中的运动力较之在LB培养基中明显增强(P＜0.05),而qseC缺陷株的变化不明显.CLSM和SEM对PVC表面细菌生物被膜的检测结果表明,EPI增强MC1000菌株生物被膜形成能力,而对qseC缺陷株的影响不大.结论 肾上腺素促进大肠埃希氏菌在生物材料表面细菌生物被膜的形成,该作用由qseC介导.

abstractsObjective To study the effect of epinephrine on biofilm formation of the qseC-deleted mutant of Escherichia coli on biomaterial.Methods The strains used in this study are Escherichia coli MC1000 and MC1000AqseC.LB was used for all the experiments.To determine the effect of epinephrine on motility,halos were measured in LB medium at 37℃ in the presence of epinephrine(50 μmol/L).LB with epinephrine and without epinephrine were used,and then the experiment of bacterial biofilm formation on PVC material was taken.The relative amount of biofilm was estimated.The thickness of bacterial community and bacterial community quantity in the unit area on PVC materials were measured by confocal laser scanning microscope( CLSM),and the surface structure of biofilm formation was observed by scanning electron microscope(SEM).Results The mutant strain formed less biofilm than the wild-type strain in LB.The increment in motility of wild-type strain due to epinephrine addition was shown,but mutant strain is unaffected.Similarly,biofilm formation of the wild-type strain was increased by epinephrine,but epinephrine did not affect the biofilm formation of the qseC mutant.The CLSM and SEM showed that epinephrine stimulated biofilm formation of wild-type strain on PVC materials,but had no effect on qseC-deleted mutant strain.Conclusion Epinephrine increases Escherichia coli biofilms on biomaterials through qseC.