40
(Wallbanks et al. 1990 ). Further isolates have been studied by Schmidtke and Carson
( 1994 ).
Based on an examination of only one culture of Vag. salmoninarum , it was established that there was 96.3 % homology with Vag. salmoninarum in the
1,340- nucleotide region of the 16S rRNA. Slightly lower homology values of
94.5 %, 94.1 %, 94.0 %, 93.8 % and 93.7 % were obtained with En. durans, Car.
divergens, En. avium, Car. piscicola and Car. mobile, respectively. Despite the very
high similarity to Vag. fl uvialis , strain 051–68
T was described in a new species, as
Vagococcus salmoninarum. It remains for the examination of further isolates to
determine the level of genetic variability within the taxon.
Pathogenicity
Laboratory infections with Vag. salmoninarum were achieved using a comparatively high dose of 1.8 × 10
6 cells/rainbow trout (Michel et al. 1997 ).
Box 2.8: Vagococcus salmoninarum
Cultures comprise short or oval non-motile, facultatively anaerobic Grampositive rods, which produce H 2 S but not arginine dihydrolase or catalase.
Aesculin and blood (α -haemolysis), but not sodium hippurate or urea, are
degraded. Nitrates are not reduced. The Voges Proskauer reaction is negative.
Acid is produced from amygdalin, arbutin, N-acetylglucosamine, cellobiose,
fructose, ß-gentiobiose, glucose (gas is not produced), maltose, mannose,
α-methyl-D-glucoside, ribose, salicin, starch, sucrose, D-tagatose and trehalose, but not from D or L-arabinose, D or L-arabitol, adonitol, dulcitol, erythritol, D or L fucose, galactose, gluconate, glycogen, glycerol, 2 or
5-keto-gluconate, inulin, inositol, lactose, D-lyxose, melibiose, melezitose,
methyl-xyloside, methyl-D-mannoside, mannitol, rhamnose, raffi nose, sorbose, sorbitol, D-turanose, D or L-xylose or xylitol. Growth occurs at 5–30 °C
but not 40 °C, and at pH 9.6. The major cellular fatty acids are of the straightchain saturated and mono-unsaturated types. The G + C ratio of the DNA is
36.0–36.5 mol %.
2 Gram-Positive Bacteria (Anaerobes and ‘Lactic Acid’ Bacteria)
(Wallbanks et al. 1990 ). Further isolates have been studied by Schmidtke and Carson
( 1994 ).
Based on an examination of only one culture of Vag. salmoninarum , it was established that there was 96.3 % homology with Vag. salmoninarum in the
1,340- nucleotide region of the 16S rRNA. Slightly lower homology values of
94.5 %, 94.1 %, 94.0 %, 93.8 % and 93.7 % were obtained with En. durans, Car.
divergens, En. avium, Car. piscicola and Car. mobile, respectively. Despite the very
high similarity to Vag. fl uvialis , strain 051–68
T was described in a new species, as
Vagococcus salmoninarum. It remains for the examination of further isolates to
determine the level of genetic variability within the taxon.
Pathogenicity
Laboratory infections with Vag. salmoninarum were achieved using a comparatively high dose of 1.8 × 10
6 cells/rainbow trout (Michel et al. 1997 ).
Box 2.8: Vagococcus salmoninarum
Cultures comprise short or oval non-motile, facultatively anaerobic Grampositive rods, which produce H 2 S but not arginine dihydrolase or catalase.
Aesculin and blood (α -haemolysis), but not sodium hippurate or urea, are
degraded. Nitrates are not reduced. The Voges Proskauer reaction is negative.
Acid is produced from amygdalin, arbutin, N-acetylglucosamine, cellobiose,
fructose, ß-gentiobiose, glucose (gas is not produced), maltose, mannose,
α-methyl-D-glucoside, ribose, salicin, starch, sucrose, D-tagatose and trehalose, but not from D or L-arabinose, D or L-arabitol, adonitol, dulcitol, erythritol, D or L fucose, galactose, gluconate, glycogen, glycerol, 2 or
5-keto-gluconate, inulin, inositol, lactose, D-lyxose, melibiose, melezitose,
methyl-xyloside, methyl-D-mannoside, mannitol, rhamnose, raffi nose, sorbose, sorbitol, D-turanose, D or L-xylose or xylitol. Growth occurs at 5–30 °C
but not 40 °C, and at pH 9.6. The major cellular fatty acids are of the straightchain saturated and mono-unsaturated types. The G + C ratio of the DNA is
36.0–36.5 mol %.
2 Gram-Positive Bacteria (Anaerobes and ‘Lactic Acid’ Bacteria)