610
Halomonadaceae Representative
Halomonas (=Deleya) cupida
Characteristics of the Disease
During April to June 1984, heavy mortalities occurred in black sea bream,
Acanthopagrus schlegeli, fry (up to 14 days after hatching) in hatcheries in western
Japan. Generally, the fi sh were too small to discern disease signs (Kusuda et al.
1986 ).
Isolation
Although the wisdom of using homogenates of whole fi sh for bacteriological examination may be debated, it is probably an acceptable compromise with fry.
Nevertheless, care needs to be taken when interpreting results insofar as bacteria
may be derived from the normal surface/intestinal microfl ora as well as from diseased tissues. In this investigation, cultures were obtained from homogenates following inoculation of BHIA with incubation at 25 °C for 24 h (Kusuda et al. 1986 ).
Characteristics of the Pathogen
Homogenates of black sea bream revealed the presence of Halomonas (=Deleya)
cupida (=Alcaligenes cupidus), V. alginolyticus and V. nereis (Kusuda et al. 1986 ).
From these characteristics, a close relationship to Alcaligenes cupidus was noted
(see Kersters and De Ley 1984 ). The only discrepancy concerned acid production
from fructose. However, this taxon was re-classifi ed as Deleya cupida (Baumann
Box 11.6: Halomonas cupida
Cultures comprise motile Gram-negative salt-requiring rods, which grow at
10–25 °C but not at 4 °C and 30 °C, and are unreactive in the oxidativefermentative test. Arginine dihydrolase, catalase and lysine and ornithine
decarboxylase are produced, but not H 2 S, indole or oxidase. Nitrates are
reduced, but the methyl red test and Voges Proskauer reaction are negative.
Haemolysis is recorded to eel erythrocytes, but not those of sheep or yellowtail. Sensitivity is recorded to the vibriostatic agent, O/129. Acid is produced
from adonitol, galactose, lactose, maltose, mannitol, L rhamnose, D sorbitol,
salicin, sucrose (weak) and trehalose, but not from fructose or inulin.
11 Miscellaneous Pathogens
Halomonadaceae Representative
Halomonas (=Deleya) cupida
Characteristics of the Disease
During April to June 1984, heavy mortalities occurred in black sea bream,
Acanthopagrus schlegeli, fry (up to 14 days after hatching) in hatcheries in western
Japan. Generally, the fi sh were too small to discern disease signs (Kusuda et al.
1986 ).
Isolation
Although the wisdom of using homogenates of whole fi sh for bacteriological examination may be debated, it is probably an acceptable compromise with fry.
Nevertheless, care needs to be taken when interpreting results insofar as bacteria
may be derived from the normal surface/intestinal microfl ora as well as from diseased tissues. In this investigation, cultures were obtained from homogenates following inoculation of BHIA with incubation at 25 °C for 24 h (Kusuda et al. 1986 ).
Characteristics of the Pathogen
Homogenates of black sea bream revealed the presence of Halomonas (=Deleya)
cupida (=Alcaligenes cupidus), V. alginolyticus and V. nereis (Kusuda et al. 1986 ).
From these characteristics, a close relationship to Alcaligenes cupidus was noted
(see Kersters and De Ley 1984 ). The only discrepancy concerned acid production
from fructose. However, this taxon was re-classifi ed as Deleya cupida (Baumann
Box 11.6: Halomonas cupida
Cultures comprise motile Gram-negative salt-requiring rods, which grow at
10–25 °C but not at 4 °C and 30 °C, and are unreactive in the oxidativefermentative test. Arginine dihydrolase, catalase and lysine and ornithine
decarboxylase are produced, but not H 2 S, indole or oxidase. Nitrates are
reduced, but the methyl red test and Voges Proskauer reaction are negative.
Haemolysis is recorded to eel erythrocytes, but not those of sheep or yellowtail. Sensitivity is recorded to the vibriostatic agent, O/129. Acid is produced
from adonitol, galactose, lactose, maltose, mannitol, L rhamnose, D sorbitol,
salicin, sucrose (weak) and trehalose, but not from fructose or inulin.
11 Miscellaneous Pathogens