376
tive immune genes, comprising the transformation of resident cells into macrophagelike cells, and the increased occurrence of CD8 α and IgM cells (Deshmukh et al.
2013 ).
The initial attempts to produce vaccines for ERM may be traced back to the work
of Ross and Klontz ( 1965 ). These workers used a phenol inactivated vaccine, which
was administered orally, via the food. Success was most encouraging, insofar as
90 % of the vaccinated fi sh survived subsequent infection with Y. ruckeri. A comparison of different methods of bacterial inactivation convinced Anderson and Ross
( 1972 ) that 3 % chloroform was better than sonication, 1 % formalin, or 0.5 % or 3 %
phenol. Passive immunisation confi rmed that the fi sh produced humoral antibodies
to chloroform inactivated cells (Busch 1978 ). Commercial interest in Y. ruckeri vaccines grew with the involvement of the now defunct Tavolek Company. Amend et al.
( 1983 ), examining factors affecting the potency of preparations, reported that
potency was not affected by pH values of 6.5 to 7.7, or by cultivation for up to 96 h
in TSB at room temperature. This team concluded that inactivation, whether by
formalin or chloroform, did not matter. However, there was good evidence that protection was enhanced by culturing the cells for 48 h at pH 7.2, lysing them at pH 9.8
for 1–2 h, and then adding 0.3 % (w/v) formalin. A live auxotrophic aroA mutant
was evaluated by i.p. injection in rainbow trout, and an RPS of 90 % recorded after
challenge (Temprano et al. 2005 ).
Application of these vaccine formulations may be by the oral route, i.e. on food
(Klontz 1963 ; Ross and Klontz 1965 ; Anderson and Nelson 1974 ; Villumsen et al.
2014 ), by injection (Anderson and Nelson 1974 ; Cossarini-Dunier 1986 ), by immersion, shower or spray (Johnson and Amend 1983a , b ), nasally (LaPatra et al. 2015 )
or by anal intubation (Johnson and Amend 1983b ). Immersion vaccination of rainbow trout using a inactivated whole-cell vaccine with and without Montanide IMS
1312 VG led to better protection when the adjuvant was present. Thus without
Montanide, the RPS after challenge was 80–82 % whereas with adjuvant, the corresponding RPS was 93.8–100 % (Soltani et al. 2014 ). Researching vaccination to
Y. ruckeri O1 biotype 2 in rainbow trout, Chettri et al. ( 2013 ) used a commercial
product, which was used at recommended or a greater dilution by immersion or
injection with or without boosters. Challenge was 3–7 months after the initial vaccination. At 3-months, the best results in terms of protection were the single injection where the group had a mortality of 2 %, and the immersion in the manufacturer’s
recommended dose plus a booster by injection 1 month later where there was 0 %
mortality, in comparison the unvaccinated controls with 76 % mortalities. At
5-months after the initial vaccination, the corresponding mortalities levels were 5 %
and 0 %, and 26 % for the controls. At 7-month, the injection vaccinated fi sh demonstrated 17 % mortalities compared to 44 % mortalities of the controls. At this this
time, there was not any evidence of protection for the fi sh that received a single
immersion dose. Clearly, the use of vaccination by injection and the use of a booster
dose resulted in long term health benefi ts to rainbow trout (Chettri et al. 2013 ).
6 Enterobacteriaceae Representatives
tive immune genes, comprising the transformation of resident cells into macrophagelike cells, and the increased occurrence of CD8 α and IgM cells (Deshmukh et al.
2013 ).
The initial attempts to produce vaccines for ERM may be traced back to the work
of Ross and Klontz ( 1965 ). These workers used a phenol inactivated vaccine, which
was administered orally, via the food. Success was most encouraging, insofar as
90 % of the vaccinated fi sh survived subsequent infection with Y. ruckeri. A comparison of different methods of bacterial inactivation convinced Anderson and Ross
( 1972 ) that 3 % chloroform was better than sonication, 1 % formalin, or 0.5 % or 3 %
phenol. Passive immunisation confi rmed that the fi sh produced humoral antibodies
to chloroform inactivated cells (Busch 1978 ). Commercial interest in Y. ruckeri vaccines grew with the involvement of the now defunct Tavolek Company. Amend et al.
( 1983 ), examining factors affecting the potency of preparations, reported that
potency was not affected by pH values of 6.5 to 7.7, or by cultivation for up to 96 h
in TSB at room temperature. This team concluded that inactivation, whether by
formalin or chloroform, did not matter. However, there was good evidence that protection was enhanced by culturing the cells for 48 h at pH 7.2, lysing them at pH 9.8
for 1–2 h, and then adding 0.3 % (w/v) formalin. A live auxotrophic aroA mutant
was evaluated by i.p. injection in rainbow trout, and an RPS of 90 % recorded after
challenge (Temprano et al. 2005 ).
Application of these vaccine formulations may be by the oral route, i.e. on food
(Klontz 1963 ; Ross and Klontz 1965 ; Anderson and Nelson 1974 ; Villumsen et al.
2014 ), by injection (Anderson and Nelson 1974 ; Cossarini-Dunier 1986 ), by immersion, shower or spray (Johnson and Amend 1983a , b ), nasally (LaPatra et al. 2015 )
or by anal intubation (Johnson and Amend 1983b ). Immersion vaccination of rainbow trout using a inactivated whole-cell vaccine with and without Montanide IMS
1312 VG led to better protection when the adjuvant was present. Thus without
Montanide, the RPS after challenge was 80–82 % whereas with adjuvant, the corresponding RPS was 93.8–100 % (Soltani et al. 2014 ). Researching vaccination to
Y. ruckeri O1 biotype 2 in rainbow trout, Chettri et al. ( 2013 ) used a commercial
product, which was used at recommended or a greater dilution by immersion or
injection with or without boosters. Challenge was 3–7 months after the initial vaccination. At 3-months, the best results in terms of protection were the single injection where the group had a mortality of 2 %, and the immersion in the manufacturer’s
recommended dose plus a booster by injection 1 month later where there was 0 %
mortality, in comparison the unvaccinated controls with 76 % mortalities. At
5-months after the initial vaccination, the corresponding mortalities levels were 5 %
and 0 %, and 26 % for the controls. At 7-month, the injection vaccinated fi sh demonstrated 17 % mortalities compared to 44 % mortalities of the controls. At this this
time, there was not any evidence of protection for the fi sh that received a single
immersion dose. Clearly, the use of vaccination by injection and the use of a booster
dose resulted in long term health benefi ts to rainbow trout (Chettri et al. 2013 ).
6 Enterobacteriaceae Representatives