476
Pseudomonas alcaligenes
A fatal disease was recognized in a breeding station for Chinese sturgeon ( Acipenser
sinensis ) summer (July) when the water temperature was 28 +/− 2 °C (Xu et al.
2015 ).
Characteristics of the Disease
The fi sh appeared to be normal before fl oating to the water surface. There were
small numbers of dead fi sh observed daily, but the overall number of mortalities was
high. Diseased fi sh were anaemic, the gills were pale with swollen and haemorrhagic fi laments. Blood spots were present in the oral cavity, and petechiae were
present in the pale livers and the digestive tract; haemorrhaging was observed in the
gonads and kidney. The spleen was swollen, and reddish in colour. Some ascites
was present (Xu et al. 2015 ).
Isolation
Isolation was achieved from the liver and kidney of moribund fi sh using BHIA with
incubation at 28 °C for 10 days (Xu et al. 2015 ).
Characteristics of the Pathogen
Box 9.1: Pseudomonas alcaligenes
Colonies are white, translucent, circular and entire, and contained Gramnegative rods of ~ 2.4 × 0.8 μm that occur singly or in pairs, and are motile by
single polar fl agella. Phenotypic traits were determined using BIOLOG-GN,
and key characters that met the description of Ps. alcaligenes include utilization of lactate, L-alanine, L-arginine, L-glutamic acid, pyruvate, L-lactic acid,
L-malic acid, succinic acid and acetic acid, but not D-maltose, D-trehalose,
sucrose, stachyose, α-D-glucose, D-mannose, D-fructose, D-galactose or
L-serine. There was a 99 % homology with Ps. alcaligenes by sequencing the
16S rRNA gene (Xu et al. 2015 ).
9 Pseudomonads
Pseudomonas alcaligenes
A fatal disease was recognized in a breeding station for Chinese sturgeon ( Acipenser
sinensis ) summer (July) when the water temperature was 28 +/− 2 °C (Xu et al.
2015 ).
Characteristics of the Disease
The fi sh appeared to be normal before fl oating to the water surface. There were
small numbers of dead fi sh observed daily, but the overall number of mortalities was
high. Diseased fi sh were anaemic, the gills were pale with swollen and haemorrhagic fi laments. Blood spots were present in the oral cavity, and petechiae were
present in the pale livers and the digestive tract; haemorrhaging was observed in the
gonads and kidney. The spleen was swollen, and reddish in colour. Some ascites
was present (Xu et al. 2015 ).
Isolation
Isolation was achieved from the liver and kidney of moribund fi sh using BHIA with
incubation at 28 °C for 10 days (Xu et al. 2015 ).
Characteristics of the Pathogen
Box 9.1: Pseudomonas alcaligenes
Colonies are white, translucent, circular and entire, and contained Gramnegative rods of ~ 2.4 × 0.8 μm that occur singly or in pairs, and are motile by
single polar fl agella. Phenotypic traits were determined using BIOLOG-GN,
and key characters that met the description of Ps. alcaligenes include utilization of lactate, L-alanine, L-arginine, L-glutamic acid, pyruvate, L-lactic acid,
L-malic acid, succinic acid and acetic acid, but not D-maltose, D-trehalose,
sucrose, stachyose, α-D-glucose, D-mannose, D-fructose, D-galactose or
L-serine. There was a 99 % homology with Ps. alcaligenes by sequencing the
16S rRNA gene (Xu et al. 2015 ).
9 Pseudomonads