In this 21-day study, we examined the effects of the aqueous methanolic extract of thin-skinned plum (Prunus domestica) on growth, immune response and resistance to a pathogenic bacterium, Yersinia ruckeri in rainbow trout (Oncorhynchus mykiss). Fish were fed with diets containing thin-skinned plum extract doses as 0 (Control) 0.1 (PD01), 0.5 (PD05) and 1% (PD1) ad libitum twice in a day. At the end of the study, growth was affected positively but not significantly. Feed conversion ratio (FCR) was decreased in the PD01 group (P < 0.05). There were elevated respiratory burst and potential bacterial killing activities on the 7th day in the PD1 fish group. No differences were observed in lysozyme activity (P > 0.05). An increased myeloperoxidase activity was recorded on the 14th day of study. Expression of interleukin and COX-2 genes was elevated on the 7th day of study in the kidney and intestine of treated fish. Histological results indicated no marked changes in organs (gill, kidney, liver and spleen) of PD treated fish groups. Challenge results of fish in all plum extract-treated groups showed an increased survival rate against Y. ruckeri (P < 0.05). This study indicated that the thin-skinned plum aqueous methanolic extract could improve innate immunity, survival against Y. ruckeri and decrease the FCR level.

在这项为期21天的研究中，我们研究了薄皮李子（Prunus domestica）的甲醇提取物对虹鳟鱼（Oncorhynchus mykiss）的生长，免疫应答和对病原细菌Rerseria ruckeri的抵抗力。鱼的饲料中随意添加薄皮李子提取物，剂量分别为0（对照）0.1（PD01），0.5（PD05）和1％（PD1）一天两次。在研究结束时，生长受到积极影响，但影响不大。PD01组的饲料转化率（FCR）降低（P <0.05）。在PD1鱼组中，第7天呼吸爆发增加，潜在的细菌杀伤活性增加。溶菌酶活性未见差异（P> 0.05）。在研究的第14天记录到髓过氧化物酶活性增加。研究的第7天，在处理过的鱼的肾脏和肠中白介素和COX-2基因的表达升高。组织学结果表明，PD处理的鱼群的器官（（，肾，肝和脾）没有明显变化。在所有李子提取物治疗组中，鱼的攻击结果表明，它们对Y. ruckeri的存活率提高了（P ＜0.05）。这项研究表明，皮薄的李子含水甲醇提取物可以提高先天免疫力，抵抗卢氏耶尔森菌的存活率并降低FCR水平。