背景：
铜绿假单胞菌的抗生素耐药菌株是医院内革兰氏阴性感染的原因，特别是在免疫抑制患者。细菌含有las I和las R基因，这些基因在攻击的发病机制和机制中起着非常重要的作用。这些基因可受到群体感应（QS）系统的影响，并且这种机制在全世界变得临床上变得重要。本研究旨在探讨的发病相关基因在铜绿假单胞菌的表达，拉斯拉斯维加斯我和R绿咖啡提取物（GCE）的预防作用。

方法：
总共54个铜绿假单胞菌菌株分离出的从使用常规显微镜和生化方法不同医院（德黑兰省）感染病房100个收集的临床样品。阐明了分离物对不同抗生素，GCE和绿原酸的敏感性。进行多重聚合酶链反应（PCR）和实时PCR以检测和定量las I和las R基因的表达水平。通过HPLC确认GCE中存在绿原酸。

结果：
抗生素敏感性测试显示这40株的临床分离物中多药耐药性是耐环丙沙星（74.07％），43对头孢他啶（79.26％），29至阿米卡星（53.7％），42至氨苄青霉素（77.77％），17至粘菌素（31.48％），40对庆大霉素（74.77％），和50至哌拉西林（92.59％）。 PCR的结果显示出其的拉斯拉斯我和R基因的频率在从绿脓杆菌的临床和标准菌株（ATCC 15449）中分离敏感和抗性菌株分别为100％。实时PCR分析显示GCE显着阻止了铜绿假单胞菌中las I和las R基因的表达。 GCE和浓度水平低至2.5毫克/毫升可以防止粉碎的铜绿假单胞菌的临床分离株中的表达及LASR基因。

结论：
当细菌暴露于GCE在铜绿假单胞菌菌株拉斯拉斯我的存在和表达水平和R基因进行了研究。我们的结果倾向于表明，参与的发病机制的基因：绿脓杆菌是下降的绿原酸的群体感应效应调节，并且因此GCE可以像在打击绿脓杆菌的多药耐药菌株的佐剂是有用的。

BACKGROUND:
Antibiotic resistant strains of Pseudomonas aeruginosa are the cause of Gram negative nosocomial infections especially among the immunosuppressed patients. The bacteria contains las I and las R genes that play very important roles in the pathogenesis and mechanisms of aggression. These genes can be influenced by the quorum sensing (QS) system and such mechanism is becoming clinically important worldwide. This study aimed to investigate the preventive effects of green coffee extract (GCE) on the expression of pathogenesis-related genes, las I and las R in P. aeruginosa.

METHODS:
A total of fifty four P. aeruginosa strains were isolated out of 100 clinical samples collected from the infectious wards in different hospitals (Tehran province) using conventional microscopic and biochemical methods. Susceptibility of the isolates to different antibiotics, GCE and chlorogenic acid were elucidated. Multiplex polymerase chain reaction (PCR) and real-time PCR were performed to detect and quantify the expression levels of las I and las R genes. The presence of chlorogenic acid in GCE was confirmed by HPLC.

RESULTS:
Antibiotic susceptibility tests revealed multidrug resistance among the clinical isolates of those 40 strains were resistant to ciprofloxacin (74.07%), 43 to ceftazidime (79.26%), 29 to amikacin (53.7%), 42 to ampicillin (77.77%), 17 to colistin (31.48%), 40 to gentamicin (74.77%), and 50 to piperacillin (92.59%). PCR outcomes exhibited that the frequency of las I and las R genes were 100% in resistant and sensitive strains isolated from clinical and standard strains of P. aeruginosa (ATCC 15449). Real-time PCR analyses revealed that GCE significantly prevented the expression of las I and las R genes in P. aeruginosa. GCE at concentration level as low as 2.5 mg/mL could prevent the expression of lasI and lasR genes in P. aeruginosa clinical isolates.

CONCLUSION:
The presence and expression levels of las I and las R genes in P. aeruginosa isolates were investigated when the bacteria was exposed to GCE. Our results tend to suggest that genes involved in pathogenesis of: Pseudomonas aeruginosa are down regulated by quorum sensing effect of chlorogenic acid and therefore GCE could be useful as an adjuvant in combating multidrug resistance strains of Pseudomonas aeruginosa.

https://www.ncbi.nlm.nih.gov/pubmed/31187452