Yin Hongping, Deng Yifeng, Wang Huafu, Liu Wugao, Zhuang Xiyi, Chu Weihua
Department of Veterinary Surgery, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Lishui People's Hospital, the Sixth Affiliated Hospital of Wenzhou Medical University, Lishui 323000, China.
Sci Rep. 2015 Nov 9;5:16158. doi: 10.1038/srep16158.
Green tea, a water extract of non-fermented leaves of Camellia sinensis L., is one of the nonalcoholic beverages in China. It is becoming increasingly popular worldwide, because of its refreshing, mild stimulant and medicinal properties. Here we examined the quorum sensing inhibitory potentials of tea polyphenols (TP) as antivirulence compounds both in vitro and in vivo. Biosensor assay data suggested minimum inhibitory concentrations (MICs) of TP against selected pathogens were 6.25 ~ 12.5 mg/mL. At sub-MIC, TP can specifically inhibit the production of violacein in Chromobacterium violaceum 12472 with almost 98% reduction at 3.125 mg/mL without affecting its growth rate. Moreover, TP exhibited inhibitory effects on virulence phenotypes regulated by QS in Pseudomonas aeruginosa. The total proteolytic activity, elastase, swarming motility and biofilm formation were reduced in a concentration-dependent manner. In vivo, TP treatment resulted in the reduction of P. aeruginosa pathogenicity in Caenorhabditis elegans. When its concentration was 3.125 mg/mL, the survival rate reached 63.3%. In the excision wound infection model, the wound contraction percentage in treatment groups was relatively increased and the colony-forming units (CFU) in the wound area were significantly decreased. These results suggested that TP could be developed as a novel non-antibiotic QS inhibitor without killing the bacteria but as an antivirulence compound to control bacterial infection.
绿茶是茶树（Camellia sinensis L.）未发酵叶片的水提取物，是中国的非酒精饮料之一。由于其提神、温和的刺激作用和药用特性，它在全球越来越受欢迎。在这里，我们研究了茶多酚（TP）作为抗毒力化合物在体外和体内的群体感应抑制潜力。生物传感器测定数据表明，TP对选定病原体的最小抑菌浓度（MIC）为6.25~12.5mg/mL。在亚MIC浓度下，TP可以特异性抑制紫色杆菌（Chromobacterium violaceum）12472中紫菌素的产生，在3.125mg/mL时减少近98%，而不影响其生长速率。此外，TP对铜绿假单胞菌中由群体感应调节的毒力表型具有抑制作用。总蛋白水解活性、弹性蛋白酶、群集运动性和生物膜形成均呈浓度依赖性降低。在体内，TP处理导致秀丽隐杆线虫中铜绿假单胞菌的致病性降低。当浓度为3.125mg/mL时，存活率达到63.3%。在切除伤口感染模型中，治疗组的伤口收缩百分比相对增加，伤口区域的菌落形成单位（CFU）显著减少。这些结果表明，TP可以开发成为一种新型的非抗生素群体感应抑制剂，不杀死细菌，而是作为一种抗毒力化合物来控制细菌感染。
