134
bilateral exophthalmia was reported. Internally, there was bloody ascites, splenomegaly, peritonitis, the stomach fi lled with mucoidal contents, the presence of petechia, and fl uid or pus fi lled cavities on the internal organs (Olsen et al. 2006b ).
Adhesions were present in the peritoneum, consistent with the administration of
oil-adjuvanted vaccines (Olsen et al. 2006).
The organism has been recovered also from oil-adjuvant vaccinated Atlantic
salmon smolts [cumulative mortality = <0.5 %] in Chile (Perdiguero et al. 2011 ).
Here, the diseased fi sh displayed scale loss, some haemorrhaging at the peduncle,
and tail erosion.
Isolation
Kidney and sometimes ascitic fl uid was inoculated onto 4 % (v/v) bovine or horse
blood agar with incubation at 15 and 22 °C for 7 days (Olsen et al. 2006b ).
Characteristics of the Pathogen
16S rDNA sequencing revealed 99.9 % and 100 % homology between Scottish
and Norwegian isolates and Rhodococcus erythropolis, respectively (Olsen et al.
2006).
Epizootiology
There was a link between the administration of oil-adjuvanted vaccines intraperitoneally. Olsen et al. (2006) speculated that the oil may be a source of nutrition and
may give protection to the rhodococci. However, the precise source/origin of the
organism was not determined.
Box 3.20: Rhodococcus erythropolis
Cultures comprise round, shiny, off-white colonies that contain strictly aerobic, non-haemolytic, Gram-positive rods that produce catalase but not oxidase, grow well at 30 rather than 15 °C and not at all at 4 or 37 °C, and grow
less well in the presence of only 1.5 % (w/v) NaCl. N-acetyl-glucosamine,
adipate, D-arabitol, gluconate, glucose, glycerol, inositol, malate, mannitol,
phenylacetate, sorbitol, sucrose and trehalose are utilised, but not aesculin,
amygdalin, D-and L-arabinose, caprate, cellobiose, dulcitol, D- and L-fucose,
galactose, ß-gentibiose, glycogen, inulin, 2-keto-gluconate, lactose, D-lyxose,
maltose, D-mannose, melezitose, melibiose, α-methyl-D-glucoside, ß-methyl
xyloside, α-methyl-D-mannoside, D-raffi nose, rhamnose, salicin, L-sorbose,
starch, D-tagatose, D-turanose, D- and L-xylose (Olsen et al. 2006b ).
3 Aerobic Gram-Positive Rods and Cocci
bilateral exophthalmia was reported. Internally, there was bloody ascites, splenomegaly, peritonitis, the stomach fi lled with mucoidal contents, the presence of petechia, and fl uid or pus fi lled cavities on the internal organs (Olsen et al. 2006b ).
Adhesions were present in the peritoneum, consistent with the administration of
oil-adjuvanted vaccines (Olsen et al. 2006).
The organism has been recovered also from oil-adjuvant vaccinated Atlantic
salmon smolts [cumulative mortality = <0.5 %] in Chile (Perdiguero et al. 2011 ).
Here, the diseased fi sh displayed scale loss, some haemorrhaging at the peduncle,
and tail erosion.
Isolation
Kidney and sometimes ascitic fl uid was inoculated onto 4 % (v/v) bovine or horse
blood agar with incubation at 15 and 22 °C for 7 days (Olsen et al. 2006b ).
Characteristics of the Pathogen
16S rDNA sequencing revealed 99.9 % and 100 % homology between Scottish
and Norwegian isolates and Rhodococcus erythropolis, respectively (Olsen et al.
2006).
Epizootiology
There was a link between the administration of oil-adjuvanted vaccines intraperitoneally. Olsen et al. (2006) speculated that the oil may be a source of nutrition and
may give protection to the rhodococci. However, the precise source/origin of the
organism was not determined.
Box 3.20: Rhodococcus erythropolis
Cultures comprise round, shiny, off-white colonies that contain strictly aerobic, non-haemolytic, Gram-positive rods that produce catalase but not oxidase, grow well at 30 rather than 15 °C and not at all at 4 or 37 °C, and grow
less well in the presence of only 1.5 % (w/v) NaCl. N-acetyl-glucosamine,
adipate, D-arabitol, gluconate, glucose, glycerol, inositol, malate, mannitol,
phenylacetate, sorbitol, sucrose and trehalose are utilised, but not aesculin,
amygdalin, D-and L-arabinose, caprate, cellobiose, dulcitol, D- and L-fucose,
galactose, ß-gentibiose, glycogen, inulin, 2-keto-gluconate, lactose, D-lyxose,
maltose, D-mannose, melezitose, melibiose, α-methyl-D-glucoside, ß-methyl
xyloside, α-methyl-D-mannoside, D-raffi nose, rhamnose, salicin, L-sorbose,
starch, D-tagatose, D-turanose, D- and L-xylose (Olsen et al. 2006b ).
3 Aerobic Gram-Positive Rods and Cocci