Palikova Miroslava, Papezikova Ivana, Markova Zdenka, Navratil Stanislav, Mares Jan, Mares Lukas, Vojtek Libor, Hyrsl Pavel, Jelinkova Eva, Schmidt-Posthaus Heike
Department of Ecology and Diseases of Game Fish and Bees, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho tr. 1946/1, 612 42 Brno, Czech Republic.
Department of Ecology and Diseases of Game Fish and Bees, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho tr. 1946/1, 612 42 Brno, Czech Republic.
Vet Parasitol. 2017 Apr 30;238:5-16. doi: 10.1016/j.vetpar.2017.03.003. Epub 2017 Mar 6.
Proliferative kidney disease (PKD) is an endoparasitic disease of salmonid fish caused by Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea). This study presents a comprehensive view on PKD development in rainbow trout (Oncorhynchus mykiss) reared at an intensive fish breeding facility, with focus on mortality, pathology/histopathology, haematological findings and immune functions. Diseased and reference fish were sampled monthly and time course of natural infection was followed up from the onset of clinical signs (September 2014) to full recovery (January 2015). PKD- associated cumulative mortality was 30% with a peak value in October, while immunohistochemical testing indicated a continuous significant decrease in T. bryosalmonae numbers from September to December; with no parasites detected in January. During peak clinical infection, a significant decrease in red blood cell counts, haematocrit values, haemoglobin concentration, along with a reduction in lymphocytes and a significant phagocyte elevation corresponding with an increase in phagocyte oxidative burst were measured in comparison to control animals. Complement activity and total immunoglobulin plasma concentrations were also elevated, though only during the initial monitoring period (September). Individuals surviving PKD, recovered and were able to fully regenerate both renal structure and haematopoietic parameters to normal levels. Changes in the red blood cell parameters indicate anaemia and a decreased oxygen transportation capacity during the clinical disease phase. Together with an increased oxygen demand at higher temperatures and decreased oxygen solubility this could lead to decompensation and elevated mortality. The stimulation of immune parameters, and especially oxidative phagocytic burst, is likely to have had a strong effect on both, regeneration and elimination of the pathogenic agent.
增殖性肾病（PKD）是由脑粘体虫（粘孢子虫纲：软孢子虫目）引起的鲑科鱼类的一种内寄生虫病。本研究全面呈现了在集约化鱼类养殖设施中饲养的虹鳟（Oncorhynchus mykiss）的PKD发病情况，重点关注死亡率、病理学/组织病理学、血液学结果和免疫功能。每月对患病鱼和对照鱼进行采样，跟踪从临床症状出现（2014年9月）到完全恢复（2015年1月）的自然感染时间进程。与PKD相关的累计死亡率为30%，10月达到峰值，而免疫组织化学检测表明，从9月到12月，脑粘体虫数量持续显著减少；1月未检测到寄生虫。在临床感染高峰期，与对照动物相比，测量到红细胞计数、血细胞比容值、血红蛋白浓度显著下降，淋巴细胞减少，吞噬细胞显著升高，同时吞噬细胞氧化爆发增加。补体活性和血浆总免疫球蛋白浓度也有所升高，不过仅在初始监测期（9月）。从PKD中存活下来的个体恢复了，并且能够使肾脏结构和造血参数都完全恢复到正常水平。红细胞参数的变化表明在临床疾病阶段出现贫血和氧运输能力下降。再加上较高温度下氧需求增加和氧溶解度降低，这可能导致失代偿和死亡率升高。免疫参数的刺激，尤其是氧化吞噬爆发，可能对病原体的再生和清除都产生了强烈影响。
