酰基-高丝氨酸内酯(AHL)对鼠伤寒沙门氏菌生物菌膜形成的影响

Effect of acylated homoserine lactones(AHL) on the biofilm formation of Salmonella typhimurium

[目的]研究铜绿假单胞菌所产生的群体感应信号分子酰基-高丝氨酸内酯(AHL)对鼠伤寒沙门氏菌生物菌膜形成的影响,为不同菌体间群体感应的研究提供参考,为沙门氏菌的控制提供帮助。[方法]利用薄层层析法分析铜绿假单胞菌所产生AHL的成分,并通过添加0%、1.0%、1.5%、2.0%(体积分数)的AHL来研究其对鼠伤寒沙门氏菌生物菌膜形成、浮游菌体生长以及菌体泳动能力的影响。[结果]铜绿假单胞菌产生2种相同类型的AHL分子(C12-HSL和3-oxo-C8-HSL),100℃加热5 min并不会改变AHL的成分。当AHL添加量低于1.5%时,虽然浮游菌体指数生长时期受到一定抑制,但随着时间的延长,稳定期浮游菌体的生长并无显著差异,反观生物菌膜,其形成明显受到抑制。当AHL添加量达到2%时,浮游菌体生长和生物菌膜形成均受到显著抑制,说明AHL对鼠伤寒沙门氏菌生物菌膜的形成有明显抑制作用。AHL对单一菌体泳动性有显著抑制作用,而对群体泳动性有不同程度的促进作用。[结论]群体感应信号分子AHL对鼠伤寒沙门氏菌浮游菌体生长的影响受添加量调控,当AHL添加量增加到一定值时浮游菌体生长才受到抑制,但对生物菌膜的形成有明显抑制作用,且随着AHL添加量提高,抑制作用增强。

[Objectives]This study investigated the effect of quorum-sensing molecules acylated homoserine lactones（ AHL） from Pseudomonas aeruginosa on the biofilm formation of Salmonella typhimurium,which provided reference for further study of quorumsensing of different bacteria and help for the control of Salmonella. [Methods]The components of AHL from P. aeruginosa was studied by the thin-layer chromatography（ TLC）. The effect of AHL on the biofilm formation,plankton and motility of S. typhimurium was studied by adding different concentrations of AHL（ 0%,1.0%,1.5%,2.0%）. [Results]P. aeruginosa can produce two same kinds of AHL（ C12-HSL and 3-oxo-C8-HSL） and heating at 100 ℃ for 5 min had no effect on the components of AHL. When the AHL concentration was below 1. 5%,the exponential growth period of planktonic bacteria was inhibited,the stationary phase was not significantly affected,and the biofilm formation of S. typhimurium was significantly inhibited. However,both the growth of planktonic bacteria and the biofilm formation were significantly inhibited by adding 2% AHL,indicating that AHL had significant inhibition on the biofilm formation of S. typhimurium. The swimming of S. typhimurium was significantly inhibited by the presence of AHL. Conversely,the swarming was promoted by the presence of AHL. [Conclusions]The effect of quorum-sensing molecules（ AHL） on the growth of planktonic bacterial depended on the concentrations,and the planktonic bacterial was inhibited only when the concentration of AHL reached a certain value. But the presence of AHL had significant inhibition of the biofilm formation of S. typhimurium,and the inhibition was increased with the increased AHL concentration.