Nilsen Hanne, Johansen Renate, Colquhoun Duncan John, Kaada Inge, Bottolfsen Kirsten, Vågnes Øyvind, Olsen Anne Berit
Norwegian Veterinary Institute Bergen, PO Box 1263 Sentrum, 5811 Bergen, Norway.
Dis Aquat Organ. 2011 Nov 3;97(1):37-46. doi: 10.3354/dao02390.
We describe the first case from Norway of increased mortality in Atlantic salmon Salmo salar (L.), with septicaemia and necrotic myositis, associated with infection by Flavobacterium psychrophilum. The outbreak occurred in smolt of 60 to 100 g in fresh water on a land-based farm in Western Norway during winter 2008-2009. The water temperature was < 5 degrees C and the accumulated mortality was 7.0%. Necropsy of dead and moribund fish revealed a swollen dark spleen, pale liver, serohaemorrhagic ascites and haemorrhage in the abdominal fat and muscle. F. psychrophilum was isolated from the kidney and spleen of diseased fish. Muscle biopsy revealed the presence of long filamentous rods in necrotic areas of skeletal muscle. Immunohistochemistry was positive for F. psychrophilum. Identification of cultured isolates as F. psychrophilum was confirmed using phenotypic testing and sequencing of the 16S rRNA gene. Analysis by allele-specific polymerase chain reaction (allele-specific PCR) indicated that 2 different genotypes of the bacterium were present in the outbreak.
我们描述了挪威首例大西洋鲑（Salmo salar, L.）死亡率增加的病例，该病例伴有败血症和坏死性肌炎，与嗜冷黄杆菌感染有关。此次疫情于2008 - 2009年冬季在挪威西部一个陆基养殖场的淡水中60至100克的鲑鱼苗种中爆发。水温低于5摄氏度，累计死亡率为7.0%。对死亡和濒死鱼进行尸检发现脾脏肿大且颜色暗黑、肝脏苍白、浆液性出血性腹水以及腹部脂肪和肌肉出血。从患病鱼的肾脏和脾脏中分离出嗜冷黄杆菌。肌肉活检显示在骨骼肌坏死区域存在长丝状杆菌。免疫组织化学检测显示嗜冷黄杆菌呈阳性。通过表型测试和16S rRNA基因测序确认培养分离株为嗜冷黄杆菌。等位基因特异性聚合酶链反应（等位基因特异性PCR）分析表明，此次疫情中存在该细菌的2种不同基因型。
