446
1988b ). In in vivo experiments, the effi cacy of sodium nifurstyrenate was confi rmed
for chemotherapy. Thus, immersion (0.5 μg/μl for 1 h) or oral administration
(30 mg/kg body weight of fi sh/day for 4 days) reduced mortalities in yellowtail to
60.5 %, compared to 100 % among the untreated controls (Baxa et al. 1988b ).
Trimethoprim and amoxicillin (dosed at 80 mg/kg body weight of fi sh) have been
recommended in Australia (Soltani et al. 1995 ).
Tenacibaculum ovolyticum (=Flexibacter ovolyticus)
Characteristics of the Disease
T. ovolyticus led to mortalities among halibut eggs and larvae. The chorion became
dissolved, and the underlying zona radiata was damaged by exotoxins resulting in
puncturing of the egg, leakage of cell constituents and larval death (Hansen et al.
1992 ).
Isolation
Cytophaga agar, prepared in 70 % seawater, has been used for the recovery of the
pathogen (Hansen et al. 1992 ).
Characteristics of the Pathogen
The 35 isolates were described as comprising:
Box 7.20: Tenacibaculum ovolyticum
Pale yellow-pigmented long, slender (0.4 × 2–20 μm) Gram-negative rods,
which demonstrate gliding movement. Catalase and oxidase are produced, but
not so arginine dihydrolase, ß-galactosidase, H 2 S, indole or lysine or ornithine
decarboxylase. Nitrates are reduced. DNA, Tween 80 and tyrosine but not
agar, cellulose, chitin, starch or urea, are degraded. Acid is not produced aerobically from arabinose, cellobiose, glucose, lactose, mannitol, raffi nose, salicin, sucrose or xylose. Growth occurs at 4–30 °C but not 35 °C, and in >3 %
(w/v) sodium chloride. The G + C ratio of the DNA was reported as 31.0
moles % (Hansen et al. 1992 ).
7 Flavobacteria and Cytophagas
1988b ). In in vivo experiments, the effi cacy of sodium nifurstyrenate was confi rmed
for chemotherapy. Thus, immersion (0.5 μg/μl for 1 h) or oral administration
(30 mg/kg body weight of fi sh/day for 4 days) reduced mortalities in yellowtail to
60.5 %, compared to 100 % among the untreated controls (Baxa et al. 1988b ).
Trimethoprim and amoxicillin (dosed at 80 mg/kg body weight of fi sh) have been
recommended in Australia (Soltani et al. 1995 ).
Tenacibaculum ovolyticum (=Flexibacter ovolyticus)
Characteristics of the Disease
T. ovolyticus led to mortalities among halibut eggs and larvae. The chorion became
dissolved, and the underlying zona radiata was damaged by exotoxins resulting in
puncturing of the egg, leakage of cell constituents and larval death (Hansen et al.
1992 ).
Isolation
Cytophaga agar, prepared in 70 % seawater, has been used for the recovery of the
pathogen (Hansen et al. 1992 ).
Characteristics of the Pathogen
The 35 isolates were described as comprising:
Box 7.20: Tenacibaculum ovolyticum
Pale yellow-pigmented long, slender (0.4 × 2–20 μm) Gram-negative rods,
which demonstrate gliding movement. Catalase and oxidase are produced, but
not so arginine dihydrolase, ß-galactosidase, H 2 S, indole or lysine or ornithine
decarboxylase. Nitrates are reduced. DNA, Tween 80 and tyrosine but not
agar, cellulose, chitin, starch or urea, are degraded. Acid is not produced aerobically from arabinose, cellobiose, glucose, lactose, mannitol, raffi nose, salicin, sucrose or xylose. Growth occurs at 4–30 °C but not 35 °C, and in >3 %
(w/v) sodium chloride. The G + C ratio of the DNA was reported as 31.0
moles % (Hansen et al. 1992 ).
7 Flavobacteria and Cytophagas