铜绿假单胞菌是常见的人类条件致病菌，其生物被膜的形成会增强菌体的耐药性。已有文献报道绿原酸可抑制铜绿假单胞菌生物被膜的形成，本研究在此基础上主要探究了其对全局性次级代谢调控系统Gac-Rsm表达的影响。结果显示，绿原酸可抑制铜绿假单胞菌生物被膜形成的能力，降低胞外总多糖合成量，但关键胞外多糖psl的合成酶基因pslA转录未受影响，还可增强Gac-Rsm系统中关键调控因子RsmA的表达水平，降低细胞内关键信使分子环二鸟苷酸(cyclic dimeric guanosine monophosphate，c-di-GMP)水平。结果表明，绿原酸可通过增强RsmA的表达来抑制铜绿假单胞菌生物被膜的形成。

Pseudomonas aeruginosa (P. aeruginosa) is a common human opportunistic pathogen, and the biofilm formation could enhance its antibiotic tolerance. Chlorogenic acid (CA) has been reported to repress the biofilm formation of P. aeruginosa, so the present study aims to further explore the regulatory mechanism of CA, especially the effect of CA on the expression of Gac-Rsm (global secondary metabolism regulation system). The results showed that CA could repress the biofilm formation of P. aeruginosa, reduce exopolysaccharide production, although the transcription level of pslA (synthetase gene of key exopolysaccharide psl) was not significantly changed. The expression of RsmA (core regulator in Gac-Rsm system) was enhanced and the level of key signal molecule cyclic dimeric guanosine monophosphate (c-di-GMP) was reduced. It is suggested that CA represses the biofilm formation of P. aeruginosa via increasing the expression of RsmA.