432
Reduction of outbreaks of disease in fry may occur by implementation of a management strategy in which progeny of heavily infected broodstock are removed
from the population. Thus, broodstock screening may well be an effective means of
evaluating infection levels, which in turn could feed into disease management strategies (Long et al. 2014 ).
Disease Resistant Fish Amphidromous stock of ayu challenged with Fla. psychrophilum experienced reduced mortalities after challenge, than domesticated,
hybridized or landlocked fi sh (Nagai et al. 2004 ; Nagai and Sakamoto 2006 ). The
comparative resistance of the amphidromous stock could not be correlated with
innate immune parameters, for example respiratory burst, serum-killing, and phagocytic activity of leucocytes.
Vaccine Development Fla. psychrophilum has been investigated as a vaccine candidate, by passive immunisation (LaFrentz et al. 2003 ), with formalin inactivated
cells administered orally at 0.1–02 g/kg body weight of fi sh for 2 weeks or on 5 days
over 2 weeks which led to good protection of ayu after immersion challenge (Kondo
et al. 2003 ), formalin inactivated cells with water soluble adjuvant, i.e. Montanide
IMS1312 administered i.p. to ayu which led to an RPS of 33 % and 39.6 % (Nagai
et al. 2003 ), by use of surface antigens (Dumetz et al. 2006 ) and by use of an auxotroph, i.e. an aroA mutant (Thune et al. 2003 ). Administration of a formalin-killed
whole vaccine in FCA intraperitoneally led to high serum and mucosal antibody
titres in 9 weeks, and commendable protection (RPS = 83 %) (LaFrentz et al. 2002 ).
Two autogenous multivalent or divalent water-in-oil vaccines comprising whole
cells were administered intraperitoneally to rainbow trout with signifi cant protectiom resulting after challenge (Fredriksen et al. 2013 ). In parallel, formalin- and
heat-inactivated whole cell preparations of two serotypes in oily adjuvant led to
high antibody titres, but not in the skin mucus, and protection (Madetoja et al.
2006 ). Similarly, use of OMP administered intraperitoneally led to a demonstrable
immune response and protection of ayu (RPS = 64 and 71 %) and rainbow trout
(RPS = 93 and 95 %) (Rahman et al. 2002). A surface protein, coined P18, was purifi ed and the responsible gene identifi ed which encoded a 166 amino acid OmpH –
like protein. In vaccine trials using rainbow trout and intraperitoneal administration
with FCA, a high antibody titre developed and protection ensued (RPS = 88 %)
(Dumetz et al. 2006 ). The auxotroph, which has a mutation in the shikimate pathway, was used successfully by injection and immersion with hybrid striped bass
(RPS = 85 %) (Thune et al. 2003 ). A live attenuated vaccine was administered by
immersion or orally with or without alginate microencapsulation to rainbow trout,
and conferred protection from challenge (Ghosh et al. 2015 ). A live attenuated
strain, CSF259-93B.17 grown under conditions of iron-limitation or in the presence
of iron was used as a vaccine administered by injection or immersion in coho
salmon. Following vaccination by injection, the RPS values after challenge were
98 % and 90 % for the iron-limited and iron-replete preparations, respectively. By
immersion, the corresponding RPS values were 73 % and 46 % (Long et al. 2013 ).
Similarly, the use of subcellular components, specifi cally fractions of 18–28, 41–49
7 Flavobacteria and Cytophagas
Reduction of outbreaks of disease in fry may occur by implementation of a management strategy in which progeny of heavily infected broodstock are removed
from the population. Thus, broodstock screening may well be an effective means of
evaluating infection levels, which in turn could feed into disease management strategies (Long et al. 2014 ).
Disease Resistant Fish Amphidromous stock of ayu challenged with Fla. psychrophilum experienced reduced mortalities after challenge, than domesticated,
hybridized or landlocked fi sh (Nagai et al. 2004 ; Nagai and Sakamoto 2006 ). The
comparative resistance of the amphidromous stock could not be correlated with
innate immune parameters, for example respiratory burst, serum-killing, and phagocytic activity of leucocytes.
Vaccine Development Fla. psychrophilum has been investigated as a vaccine candidate, by passive immunisation (LaFrentz et al. 2003 ), with formalin inactivated
cells administered orally at 0.1–02 g/kg body weight of fi sh for 2 weeks or on 5 days
over 2 weeks which led to good protection of ayu after immersion challenge (Kondo
et al. 2003 ), formalin inactivated cells with water soluble adjuvant, i.e. Montanide
IMS1312 administered i.p. to ayu which led to an RPS of 33 % and 39.6 % (Nagai
et al. 2003 ), by use of surface antigens (Dumetz et al. 2006 ) and by use of an auxotroph, i.e. an aroA mutant (Thune et al. 2003 ). Administration of a formalin-killed
whole vaccine in FCA intraperitoneally led to high serum and mucosal antibody
titres in 9 weeks, and commendable protection (RPS = 83 %) (LaFrentz et al. 2002 ).
Two autogenous multivalent or divalent water-in-oil vaccines comprising whole
cells were administered intraperitoneally to rainbow trout with signifi cant protectiom resulting after challenge (Fredriksen et al. 2013 ). In parallel, formalin- and
heat-inactivated whole cell preparations of two serotypes in oily adjuvant led to
high antibody titres, but not in the skin mucus, and protection (Madetoja et al.
2006 ). Similarly, use of OMP administered intraperitoneally led to a demonstrable
immune response and protection of ayu (RPS = 64 and 71 %) and rainbow trout
(RPS = 93 and 95 %) (Rahman et al. 2002). A surface protein, coined P18, was purifi ed and the responsible gene identifi ed which encoded a 166 amino acid OmpH –
like protein. In vaccine trials using rainbow trout and intraperitoneal administration
with FCA, a high antibody titre developed and protection ensued (RPS = 88 %)
(Dumetz et al. 2006 ). The auxotroph, which has a mutation in the shikimate pathway, was used successfully by injection and immersion with hybrid striped bass
(RPS = 85 %) (Thune et al. 2003 ). A live attenuated vaccine was administered by
immersion or orally with or without alginate microencapsulation to rainbow trout,
and conferred protection from challenge (Ghosh et al. 2015 ). A live attenuated
strain, CSF259-93B.17 grown under conditions of iron-limitation or in the presence
of iron was used as a vaccine administered by injection or immersion in coho
salmon. Following vaccination by injection, the RPS values after challenge were
98 % and 90 % for the iron-limited and iron-replete preparations, respectively. By
immersion, the corresponding RPS values were 73 % and 46 % (Long et al. 2013 ).
Similarly, the use of subcellular components, specifi cally fractions of 18–28, 41–49
7 Flavobacteria and Cytophagas