419
Bacteriophage Bacteriophage were recovered from fi sh farms and freshwater in
Finland with a view for using them in phage therapy (Laanto et al. 2011 ). Experiments
with rainbow trout and zebra fi sh were successful insofar as a single application of
bacteriophage FCL-2 into the water supply of a fl ow-through system protected the
fi sh against challenge (Laanto et al. 2015 ).
Flavobacterium hydatis (= Cytophaga aquatilis)
Isolation
Isolation from infected tissues may be achieved on cytophaga agar (Appendix in
Chap. 12 ; after Anacker and Ordal 1959 ) and Pacha and Ordal’s medium (Pacha and
Ordal 1967 ) (Strohl and Tait 1978 ).
Characteristics of the Pathogen
On the basis of the micromorphology, gliding movement, G + C ratio, and the
ability to degrade complex molecules, this group was considered to represent a previously undescribed species of Cytophaga, for which the name of Cyt. aquatilis was
Box 7.9: Flavobacterium hydatis (= Cytophaga aquatilis)
Following incubation at 20 °C for 14 days, yellow-orange colonies develop,
which contain Gram-negative facultatively anaerobic rods of 8.0 × 0.5 μm in
size. Copious quantities of extracellular slime are produced. Cells demonstrate gliding movement. Microcysts and fruiting bodies are absent. Catalase
is produced, but not H 2 S, indole, lysine or ornithine decarboxylase, oxidase or
phenylalanine deaminase, and the methyl red test and Voges Proskauer reaction are negative. A wide range of complex molecules are degraded, including
aesculin, blood, casein, DNA, gelatin, pectin, starch, tributyrin, Tween 40, 60
and 80, and tyrosine (slowly), but not cellulose or urea. Some strains attack
chitin. Growth occurs at 5 to 35 °C but not 42 °C, in 0–2 % (w/v) sodium
chloride, which is an indication that the organism is unlikely to be present in
full strength seawater. Growth occurs also at pH 5.5–11.0. Nitrates are reduced
to ammonia. Acid is produced from arabinose, cellobiose, glucose, lactose,
mannitol, raffi nose, sucrose and xylose. The G + C content of the DNA is 33.7
moles %. Chemical analyses have established that the major pigments are
similar to the ‘fl exirubin’ of Fle. elegans (Strohl and Tait 1978 ).
Flavobacterium hydatis (= Cytophaga aquatilis)
Bacteriophage Bacteriophage were recovered from fi sh farms and freshwater in
Finland with a view for using them in phage therapy (Laanto et al. 2011 ). Experiments
with rainbow trout and zebra fi sh were successful insofar as a single application of
bacteriophage FCL-2 into the water supply of a fl ow-through system protected the
fi sh against challenge (Laanto et al. 2015 ).
Flavobacterium hydatis (= Cytophaga aquatilis)
Isolation
Isolation from infected tissues may be achieved on cytophaga agar (Appendix in
Chap. 12 ; after Anacker and Ordal 1959 ) and Pacha and Ordal’s medium (Pacha and
Ordal 1967 ) (Strohl and Tait 1978 ).
Characteristics of the Pathogen
On the basis of the micromorphology, gliding movement, G + C ratio, and the
ability to degrade complex molecules, this group was considered to represent a previously undescribed species of Cytophaga, for which the name of Cyt. aquatilis was
Box 7.9: Flavobacterium hydatis (= Cytophaga aquatilis)
Following incubation at 20 °C for 14 days, yellow-orange colonies develop,
which contain Gram-negative facultatively anaerobic rods of 8.0 × 0.5 μm in
size. Copious quantities of extracellular slime are produced. Cells demonstrate gliding movement. Microcysts and fruiting bodies are absent. Catalase
is produced, but not H 2 S, indole, lysine or ornithine decarboxylase, oxidase or
phenylalanine deaminase, and the methyl red test and Voges Proskauer reaction are negative. A wide range of complex molecules are degraded, including
aesculin, blood, casein, DNA, gelatin, pectin, starch, tributyrin, Tween 40, 60
and 80, and tyrosine (slowly), but not cellulose or urea. Some strains attack
chitin. Growth occurs at 5 to 35 °C but not 42 °C, in 0–2 % (w/v) sodium
chloride, which is an indication that the organism is unlikely to be present in
full strength seawater. Growth occurs also at pH 5.5–11.0. Nitrates are reduced
to ammonia. Acid is produced from arabinose, cellobiose, glucose, lactose,
mannitol, raffi nose, sucrose and xylose. The G + C content of the DNA is 33.7
moles %. Chemical analyses have established that the major pigments are
similar to the ‘fl exirubin’ of Fle. elegans (Strohl and Tait 1978 ).
Flavobacterium hydatis (= Cytophaga aquatilis)