不同表型表皮葡萄球菌之间的相互作用及LuxS基因对生物膜形成的影响

The interaction of different phenotype Staphylococcus epidermidis and the influence of Luxs gene on biofilm formation

目的探讨不同表型的表皮葡萄球菌(SE)之间的相互作用机制以及luxS基因在SE形成生物膜过程中所起的作用。方法分别应用TSB培养液、ATCC12228上清液以及ATCC35984上清液培养产生生物膜的SE标准菌株ATCC35984和不产生生物膜的ATCC12228菌株,并采用半定量法检测细菌间多糖黏附素(PIA)以及半定量PCR法检测LuxS基因在该菌株中的表达。结果在TSB培养液中,ATCC35984菌株能形成致密完整的生物膜,而ATCC12228菌株不能产生生物膜。在ATCC35984上清液中,ATCC12228菌株形成生物膜的能力增强,LuxS基因表达降低。在ATCC12228菌株上清液中,ATCC35984产生生物膜能力下降,LuxS基因表达增强,两者比较差异均有统计学意义(P<0.05)。结论 LuxS基因在SE形成生物膜的过程中起一定作用,并且不同表型的SE之间存在相互影响的现象。

Objective To investigate the interaction mechanisms between the different phenotype of Staphylococcus epidermidis and the role of LuxS in the process of biofilm formation. Methods SE ATCC35984 with the ability of biofilm formation and SE ATCC12228 without this ability was cultured respectively with TSB medium, SE ATCC12228 supernatant and SE ATCC35984 supematant. After 18h,polysaecharide intercellular adhesion and the expression of LuxS in the strain were detected by semi-quantitative method and semi-quantitative PCR method. Results The strain of SE ATCC35984 cultured by TSB formed dense and compact biofilm, while the strain of SE ATCC 12228 was unable to produce biological membranee. Cultured by SE ATCC35984 supematant, the ability of SE ATCC12228 biofilm formation was increased, and the expression of LuxS in the strain was reduced. Similarly, the biofilm formation ability was reduced and the expression of LuxS was increased in the strain of SE ATCC35984 cultured by ATCC12228 supernatant. The differences among these groups were significant（P 〈 0. 05 ）. Conclusion LuxS plays a key role in the process of biofilm formation of Staphylococcus epidermidis, and the different phenotype of Staphylococcus epidermidis interact with each other.