Condensed tannins (CTs), which extracted from yew leaves, tilia flower and black locust leaves, were examined for their antimicrobial in vitro activity against avian pathogenic Escherichia coli (APEC). Past research demonstrated that CTs which contain procyanidins and prodelphinidins that could inhibit the growth of a wide range of bacteria. However, there is no information on how these affect pathogenic bacteria from chickens such as APEC. The high concentration of extracts, 10, 5, 2·5 mg ml−1, affected the growth curves of APEC, which gave different inhibition values for the three CT extracts. Furthermore, these CTs had significant effects (P ≤ 0·05) on APEC biofilm and motility depending on each CT concentration and composition. However, at low concentration (0·6 mg ml−1), the tilia flowers, a high molar percentage of procyanidins, enhanced bacterial cell attachment and improved the swimming motility of APEC. In contrast, yew, an equal molar percentage of procyanidins/prodelphinidins, and black locust, a high molar percentage of prodelphinidins, interrupted and blocked swarming and swimming motility. The data suggested that the antimicrobial activity of the CT extracts was elicited by a positive relationship between anti‐biofilm formation and anti‐motility capacities.

中文翻译：

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缩合单宁提取物对禽致病性大肠杆菌的体外抗菌活性

从红豆杉叶、椴花和刺槐叶中提取的浓缩单宁 (CT) 被检测其对禽致病性大肠杆菌 (APEC) 的体外抗菌活性。过去的研究表明，含有原花青素和原飞燕草素的 CTs 可以抑制多种细菌的生长。然而，没有关于这些如何影响APEC等鸡的病原菌的信息。10, 5, 2·5 mg ml-1 的高浓度提取物影响APEC 的生长曲线，这对三种CT 提取物给出了不同的抑制值。此外，这些 CT 对 APEC 生物膜和运动有显着影响（P ≤ 0·05），具体取决于每个 CT 浓度和组成。然而，在低浓度 (0·6 mg ml−1) 下，椴花、高摩尔百分比的原花青素、增强细菌细胞附着并改善APEC的游泳运动。相比之下，红豆杉，等摩尔百分比的原花青素/原飞燕草素和黑刺槐，高摩尔百分比的原花青素，中断和阻止了蜂群和游泳运动。数据表明，CT 提取物的抗菌活性是由抗生物膜形成和抗运动能力之间的正相关关系引起的。