349
Characteristics of the Pathogen
The organisms coincided with the description of Esch. vulneris (Brenner et al.
1982 ).
Pathogenicity
There is scant information about the pathogenicity of Esch. vulneris. It would
appear that infection was achieved in rainbow trout of 120 g in weight with death
ensuing in 175 h (Aydin et al. 1997 ). Details about dosages were not included in the
original publication.
Hafnia alvei
Characteristics of the Disease
The disease was described as a haemorrhagic septicaemia (Orozova et al. 2014 ).
Fish became darker, moved slowly, developed exophthalmia, haemorrhaging in the
eye and petechial haemorrhages on the body surface. Internally, petechial haemorrhages were apparent on the spleen (enlarged) and kidney (hyperemic). The disease
appeared in fi sh after transportation or during cultivation in inappropriate conditions (Gelev and Gelev 1988 ).
A second outbreak occurred in cherry salmon ( O. masou ) on Japanese farms.
Here, the disease was characterised by melanosis, swollen abdomen, and slow
swimming. There were grey/white furuncles on the kidney (Teshima et al. 1992 ).
Box 6.6: Escherichia vulneris
Cultures comprise Gram-negative, motile, fermentative rods, which produce
arginine dihydrolase, catalase and lysine decarboxylase but not H 2 S, indole,
oxidase or ornithine decarboxylase, degrade aesculin and blood, but not
casein, DNA, gelatin, starch or urea, reduce nitrates, utilise malonate, and
produce acid from arabinose, glucose, lactose, maltose, mannitol, melibiose,
rhamnose, salicin, trehalose and xylose, but not adonitol, cellobiose, dulcitol,
glycerol, inositol, sorbitol or sucrose. The methyl red test is positive, but the
Voges Proskauer reaction is negative. Growth occurs at 37 °C but not at 5 or
42 °C.
Hafnia alvei
Characteristics of the Pathogen
The organisms coincided with the description of Esch. vulneris (Brenner et al.
1982 ).
Pathogenicity
There is scant information about the pathogenicity of Esch. vulneris. It would
appear that infection was achieved in rainbow trout of 120 g in weight with death
ensuing in 175 h (Aydin et al. 1997 ). Details about dosages were not included in the
original publication.
Hafnia alvei
Characteristics of the Disease
The disease was described as a haemorrhagic septicaemia (Orozova et al. 2014 ).
Fish became darker, moved slowly, developed exophthalmia, haemorrhaging in the
eye and petechial haemorrhages on the body surface. Internally, petechial haemorrhages were apparent on the spleen (enlarged) and kidney (hyperemic). The disease
appeared in fi sh after transportation or during cultivation in inappropriate conditions (Gelev and Gelev 1988 ).
A second outbreak occurred in cherry salmon ( O. masou ) on Japanese farms.
Here, the disease was characterised by melanosis, swollen abdomen, and slow
swimming. There were grey/white furuncles on the kidney (Teshima et al. 1992 ).
Box 6.6: Escherichia vulneris
Cultures comprise Gram-negative, motile, fermentative rods, which produce
arginine dihydrolase, catalase and lysine decarboxylase but not H 2 S, indole,
oxidase or ornithine decarboxylase, degrade aesculin and blood, but not
casein, DNA, gelatin, starch or urea, reduce nitrates, utilise malonate, and
produce acid from arabinose, glucose, lactose, maltose, mannitol, melibiose,
rhamnose, salicin, trehalose and xylose, but not adonitol, cellobiose, dulcitol,
glycerol, inositol, sorbitol or sucrose. The methyl red test is positive, but the
Voges Proskauer reaction is negative. Growth occurs at 37 °C but not at 5 or
42 °C.
Hafnia alvei