不同浓度柠檬酸钠对肺炎克雷伯菌生物被膜形成的抑制作用

目的 探讨不同浓度柠檬酸钠对肺炎克雷伯菌生物被膜(biofilm, BF)形成的抑制作用。方法 体外构建肺炎克雷伯菌BF模型；分别添加15%和7.5%的柠檬酸钠溶液，运用结晶紫法连续4d检测肺炎克雷伯菌BF的吸光度；采用扫描电镜观察其对BF的抑制情况。结果 肺炎克雷伯菌BF体外培养后其570nm吸光度值由0.2逐天升高，至第4天达到高峰0.6以上；而在添加柠檬酸后肺炎克雷伯菌BF的吸光度显著下降。其中15%的柠檬酸钠对肺炎克雷伯菌BF的抑制效果优于7.5%的柠檬酸钠溶液。结论 7.5%和15%的柠檬酸钠溶液均可抑制肺炎克雷伯菌BF的形成，且随柠檬酸钠浓度增高，抑制效果增强。

The inhibitory effect of different concentrations of sodium citrate on the biofilm formed by Klebsiella pneumoniae

Objective To assess the inhibitory effect of different concentrations of sodium citrate on the biofilm formed by Klebsiella pneumoniae. Methods A biofilm model was established in vitro. Two groups were divided into experimental groups (one added 15% concentration of sodium citrate, the other added 7.5% concentration of sodium citrate), and the control group where none of sodium citrate was added. The method of crystal violet staining was used to determine the absorbance of biofilm forfour days. Then the scanning electron microscopy was used to observe the biofilmmorphology. Results Compared with the control group, the absorbances of bioflim were all significantly decreased whether adding 15% concentration of sodium citrate or 7.5% ones. The inhibitory effect was better in 15% concentration of sodium citrate than that in 7.5%. Conclusion Sodium citrate could significantly inhibit the biofilm formation by Klebsiella pneumoniae. With the increase of sodium citrate concentration, the inhibitory effect was enhanced.