488
Pseudomonas luteola
Characteristics of the Disease
A disease outbreak occurred during 2004 in a rainbow trout farm in Turkey when
40 % of the fi sh population died, with signs including exophthalmia, melanosis,
haemorrhaging at the base of the fi ns and around the vent, pale liver, enlarged
spleen, and the intestine fi lled with yellowish fl uid (Altinok et al. 2007 ).
Isolation
The organism was recovered on TSA with incubation at 25 °C for 2 days (Altinok
et al. 2007 ).
Characteristics of the Pathogen
By means of sequencing of the 16S rDNA gene, a 99.8 % homology was recorded
to Ps. luteola (Altinok et al. 2007 ).
Pathogenicity
Experimental challenge was established by immersion of rainbow trout in
6.4 × 10
6 CFU/ml for 1 h (Altinok et al. 2007 ).
Box 9.6: Pseudomonas luteola
Cultures comprise Gram-negative, motile, oxidative, oxidase bacteria that
produce arginine dihydrolase and ß-galactosidase but not H 2 S, indole, lysine
or ornithine decarboxylase, or tryptophan deaminase. Capric acid, citrate,
glucose, malate and potassium gluconate are utilised, but not adipic acid or
phenylacetic acid. The Voges Proskauer reaction is negative. Aesculin, and
gelatin are degraded, but not urea. Acid is produced from arabinose, glucose,
inositol, D-mannose, mannitol and sucrose but not rhamnose (Altinok et al.
2007 ).
9 Pseudomonads
Pseudomonas luteola
Characteristics of the Disease
A disease outbreak occurred during 2004 in a rainbow trout farm in Turkey when
40 % of the fi sh population died, with signs including exophthalmia, melanosis,
haemorrhaging at the base of the fi ns and around the vent, pale liver, enlarged
spleen, and the intestine fi lled with yellowish fl uid (Altinok et al. 2007 ).
Isolation
The organism was recovered on TSA with incubation at 25 °C for 2 days (Altinok
et al. 2007 ).
Characteristics of the Pathogen
By means of sequencing of the 16S rDNA gene, a 99.8 % homology was recorded
to Ps. luteola (Altinok et al. 2007 ).
Pathogenicity
Experimental challenge was established by immersion of rainbow trout in
6.4 × 10
6 CFU/ml for 1 h (Altinok et al. 2007 ).
Box 9.6: Pseudomonas luteola
Cultures comprise Gram-negative, motile, oxidative, oxidase bacteria that
produce arginine dihydrolase and ß-galactosidase but not H 2 S, indole, lysine
or ornithine decarboxylase, or tryptophan deaminase. Capric acid, citrate,
glucose, malate and potassium gluconate are utilised, but not adipic acid or
phenylacetic acid. The Voges Proskauer reaction is negative. Aesculin, and
gelatin are degraded, but not urea. Acid is produced from arabinose, glucose,
inositol, D-mannose, mannitol and sucrose but not rhamnose (Altinok et al.
2007 ).
9 Pseudomonads