Marancik David P, Leeds Timothy D, Wiens Gregory D
a National Center for Cool and Cold Water Aquaculture , 11861 Leetown Road, Kearneysville , West Virginia 25430 , USA.
J Aquat Anim Health. 2014 Sep;26(3):181-9. doi: 10.1080/08997659.2014.920735.
Abstract A challenge to selectively breeding fish populations for improved disease resistance in aquaculture is an incomplete understanding of how artificial selection affects innate immunity at the host-pathogen level. The objective of this study was to determine whether Rainbow Trout Oncorhynchus mykiss bred for differential susceptibility to bacterial cold-water disease exhibited altered tissue damage and cellular inflammatory response following experimental challenge with Flavobacterium psychrophilum. Fish from disease-resistant (ARS-Fp-R) and disease-susceptible (ARS-Fp-S) lines were experimentally challenged as juveniles, and mortalities, as well as survivors, were sampled for histopathology during the acute phase of the disease. Microscopic lesions were quantified or semiquantified and statistically compared for changes over time and between genetic lines. Significant progression in the degree of perisplenitis, splenic necrosis, splenic inflammatory infiltrates, average splenic ellipsoid area, total splenic ellipsoid area, and peritonitis was present over time in both genetic lines on at least one postinfection time point. No differences were found between renal inflammatory infiltrates and renal hematopoietic cell depletion over time. Perisplenitis was significantly lower in fish from the ARS-Fp-R line on day 9 postinfection than in fish from the ARS-Fp-S line. The ARS-Fp-R line demonstrated a trend towards reduced splenic necrosis compared with the ARS-Fp-S line that approached significance, and fish from the ARS-Fp-S line were 3.6 times more likely than fish from the ARS-Fp-R line to have a higher splenic necrosis lesion score after day 3 postinfection. These findings support the hypothesis that differential survival is a result of divergence in disease magnitude and not altered disease course between genetic lines. Characterization of histopathologic changes between genetic lines and over time helps elucidate mechanisms of disease resistance and contributes to our understanding of disease pathogenesis in fish infected with F. psychrophilum. Received January 7, 2014; accepted March 10, 2014.
摘要 在水产养殖中，为提高抗病能力而对鱼类种群进行选择性育种面临的一个挑战是，人们对人工选择如何在宿主 - 病原体层面影响先天免疫的理解尚不完整。本研究的目的是确定，针对细菌性冷水病具有不同易感性的养殖虹鳟（Oncorhynchus mykiss），在受到嗜冷黄杆菌实验性攻击后，其组织损伤和细胞炎症反应是否会发生改变。将抗病品系（ARS-Fp-R）和易感病品系（ARS-Fp-S）的鱼苗在幼鱼期进行实验性攻击，在疾病急性期对死亡鱼和存活鱼进行组织病理学采样。对微观病变进行量化或半量化，并对随时间变化以及不同遗传品系之间的变化进行统计学比较。在至少一个感染后时间点上，两个遗传品系的脾周炎程度、脾脏坏死、脾脏炎性浸润、平均脾脏椭球体面积、总脾脏椭球体面积和腹膜炎随时间均有显著进展。随时间推移，两个品系的肾脏炎性浸润和肾脏造血细胞耗竭没有差异。感染后第9天，ARS-Fp-R品系鱼的脾周炎明显低于ARS-Fp-S品系鱼。与ARS-Fp-S品系相比，ARS-Fp-R品系的脾脏坏死有降低趋势，接近显著水平，感染后第3天，ARS-Fp-S品系鱼出现较高脾脏坏死病变评分的可能性是ARS-Fp-R品系鱼的3.6倍。这些发现支持了以下假设：不同的存活率是疾病严重程度差异的结果，而非不同遗传品系间疾病进程的改变。对不同遗传品系间以及随时间变化的组织病理学变化进行表征，有助于阐明抗病机制，并有助于我们理解感染嗜冷黄杆菌的鱼类的疾病发病机制。2014年1月7日收到；2014年3月10日接受。
