408
Disease Control
Antimicrobial Compounds Apparently, some level of control was exercised with
oxytetracycline (Acuigrup 1980 ). In vitro experiments have also pointed to the
value of oxytetracycline and other drugs commonly used in aquaculture (Farkas
1985 ).
Flavobacterium branchiophilum
Isolation
Isolation may be achieved using cytophaga agar (Appendix in Chap. 12 ; after
Anacker and Ordal 1959 ).
Characteristics of the Pathogen
Box 7.7: Flavobacterium branchiophilum
This pathogen forms yellow, translucent, smooth colonies of 0.5–1.0 mm in
diameter after incubation at 18 °C for 5 days. Isolates (10 isolates from
Oregon, 5 from Japan and one from Hungary; Farkas 1985 ) comprise slender,
strictly aerobic, non-motile, Gram-negative rods of 5–8 × 0.5 μm in size,
which are surrounded by pili (Heo et al. 1990 ). Usually, they occur as short
chains, each comprising 2 to 3 cells. Catalase and oxidase are produced, but
not H 2 S or indole. Nitrates are not reduced. Casein, gelatin, lecithin, starch,
tributyrin, Tweens and tyrosine were degraded, but not cellulose or chitin
(Bernardet et al. 1996 ). Growth occurs at 5 and 30 °C but at 37 °C, and in 0
and 0.1 % (w/v) sodium chloride. It is noteworthy that Japanese isolates grow
at 30 °C, whereas American strains do not. Acid is produced from a wide
range of compounds, including cellobiose, fructose, glucose, inulin, maltose,
melibiose, raffi nose, sucrose and trehalose, but not from adonitol, arabinose,
dulcitol, galactose, inositol, lactose, mannitol, salicin, sorbitol or xylose (Ko
and Heo 1997 ). The G + C ratio of the DNA is 29–34 moles %. Another geographical difference concerns serology, insofar as the Japanese isolates are
antigenically distinct from the American and Hungarian cultures (Huh and
Wakabayashi 1989 ). The complete genome sequence, which revealed a small
genome compared with other fl avobacteria, has been published of strain
FL-15, which was recovered from diseased sheatfi sh in Hungary (Touchon
et al. 2011 ).
7 Flavobacteria and Cytophagas
Disease Control
Antimicrobial Compounds Apparently, some level of control was exercised with
oxytetracycline (Acuigrup 1980 ). In vitro experiments have also pointed to the
value of oxytetracycline and other drugs commonly used in aquaculture (Farkas
1985 ).
Flavobacterium branchiophilum
Isolation
Isolation may be achieved using cytophaga agar (Appendix in Chap. 12 ; after
Anacker and Ordal 1959 ).
Characteristics of the Pathogen
Box 7.7: Flavobacterium branchiophilum
This pathogen forms yellow, translucent, smooth colonies of 0.5–1.0 mm in
diameter after incubation at 18 °C for 5 days. Isolates (10 isolates from
Oregon, 5 from Japan and one from Hungary; Farkas 1985 ) comprise slender,
strictly aerobic, non-motile, Gram-negative rods of 5–8 × 0.5 μm in size,
which are surrounded by pili (Heo et al. 1990 ). Usually, they occur as short
chains, each comprising 2 to 3 cells. Catalase and oxidase are produced, but
not H 2 S or indole. Nitrates are not reduced. Casein, gelatin, lecithin, starch,
tributyrin, Tweens and tyrosine were degraded, but not cellulose or chitin
(Bernardet et al. 1996 ). Growth occurs at 5 and 30 °C but at 37 °C, and in 0
and 0.1 % (w/v) sodium chloride. It is noteworthy that Japanese isolates grow
at 30 °C, whereas American strains do not. Acid is produced from a wide
range of compounds, including cellobiose, fructose, glucose, inulin, maltose,
melibiose, raffi nose, sucrose and trehalose, but not from adonitol, arabinose,
dulcitol, galactose, inositol, lactose, mannitol, salicin, sorbitol or xylose (Ko
and Heo 1997 ). The G + C ratio of the DNA is 29–34 moles %. Another geographical difference concerns serology, insofar as the Japanese isolates are
antigenically distinct from the American and Hungarian cultures (Huh and
Wakabayashi 1989 ). The complete genome sequence, which revealed a small
genome compared with other fl avobacteria, has been published of strain
FL-15, which was recovered from diseased sheatfi sh in Hungary (Touchon
et al. 2011 ).
7 Flavobacteria and Cytophagas