Sandell T A, Teel D J, Fisher J, Beckman B, Jacobson K C
Department of Microbiology, Oregon State University, Corvallis, OR, USA.
J Fish Dis. 2015 Apr;38(4):365-78. doi: 10.1111/jfd.12243. Epub 2014 Apr 10.
We examined 1454 juvenile Chinook salmon, Oncorhynchus tshawytscha (Walbaum), captured in nearshore waters off the coasts of Washington and Oregon (USA) from 1999 to 2004 for infection by Renibacterium salmoninarum, Nanophyetus salmincola Chapin and skin metacercariae. The prevalence and intensities for each of these infections were established for both yearling and subyearling Chinook salmon. Two metrics of salmon growth, weight residuals and plasma levels of insulin-like growth factor-1, were determined for salmon infected with these pathogens/parasites, both individually and in combination, with uninfected fish used for comparison. Yearling Chinook salmon infected with R. salmoninarum had significantly reduced weight residuals. Chinook salmon infected with skin metacercariae alone did not have significantly reduced growth metrics. Dual infections were not associated with significantly more severe effects on the growth metrics than single infections; the number of triple infections was very low and precluded statistical comparison. Overall, these data suggest that infections by these organisms can be associated with reduced juvenile Chinook salmon growth. Because growth in the first year at sea has been linked to survival for some stocks of Chinook salmon, the infections may therefore play a role in regulating these populations in the Northeast Pacific Ocean.
我们检查了1999年至2004年在美国华盛顿州和俄勒冈州海岸近岸水域捕获的1454条幼年奇努克鲑鱼（Oncorhynchus tshawytscha (Walbaum)），以检测其是否感染了鲑鱼肾杆菌、鲑居尾孢虫（Nanophyetus salmincola Chapin）和皮肤囊蚴。确定了一岁和亚一岁奇努克鲑鱼中每种感染的患病率和感染强度。测定了感染这些病原体/寄生虫的鲑鱼个体和组合的两个鲑鱼生长指标，即体重残差和胰岛素样生长因子-1的血浆水平，并与未感染的鱼进行比较。感染鲑鱼肾杆菌的一岁奇努克鲑鱼体重残差显著降低。仅感染皮肤囊蚴的奇努克鲑鱼生长指标没有显著降低。双重感染对生长指标的影响并不比单一感染严重得多；三重感染的数量非常少，无法进行统计比较。总体而言，这些数据表明，这些生物体的感染可能与幼年奇努克鲑鱼生长减缓有关。由于在海洋中的第一年生长与一些奇努克鲑鱼种群的生存有关，因此这些感染可能在调节东北太平洋的这些种群中发挥作用。
