343
formalin- inactivated whole cells of atypical Edw. tarda, administered intraperitoneally without or without oily adjuvant, to protect red sea bream. Following the i.m.
injection of 10 mg amounts of formalised cells/100 g of Japanese eels and a booster
after 7 days, an oral challenge resulted in 60–87.5 % mortalities in the vaccinates,
compared to 80–100 % deaths among controls (Gutierrez and Miyazaki 1994 ).
Rather better protection resulted from use 1 mg of LPS/100 g body weight of
Japanese eels. With this vaccine, 40–57 % mortalities were recorded compared to
80–90 % of the controls (Gutierrez and Miyazaki 1994 ). Oral vaccination at an
equivalent of 5 × 10
8 cells/fi sh/day for two 5-day periods separated by 2 weeks using
ghost cells, which were produced from lysed cultures with the lysis plasmid pλ PR
cI-Elysis, protected olive fl ounder ( Paralichthys olivaceus ) (Kwon et al. 2007 ).
ECPs have been found to modulate innate immunity, and may well become a candidate for future vaccine studies (Lee et al. 2007).
Unfortunately, Mekuchi et al. 1995b ) did not fi nd any clear sign of protection in
Japanese fl ounder, that had been vaccinated with formalised cells via the i.m., oral
or immersion routes. Other work has doubted the importance of cell-mediated
immunity in the protection of fi sh against disease (Miyazaki and Egusa 1976 ). This
is perhaps surprising in view of the current opinions concerning fi sh immunology.
Intramuscular injection of eels and red sea bream with LPS resulted in protection
from challenge with a virulent culture of Edw. tarda (Salati et al. 1987a , b ).
Moreover, there was a demonstrable humoral immune response (titre = 1:2048) and
phagocytosis by T-lymphocytes. Phagocytic activity in the eels peaked 3 weeks
after vaccination (Kusuda and Taira 1990 ). Indeed, the evidence showed that LPS
was much more successful as an immunogen than vaccination with a formalised
culture (Salati et al. 1987a , b ).
Igarashi and Iida ( 2002 ) used live attenuated and formalin-inactivated cells of a
mutant, SPM31, constructed with transposon Tn5 with reduced siderophore producing capability. Tilapia were vaccinated intraperitoneally (0.1 mg of vaccine/100 g
of fi sh) whereupon antibodies were produced and protection recorded after challenge for the live (0 % mortality) but not the formalin-inactivated (mortality = 80–100 %) preparation (Igarashi and Iida 2002 ). Interest in live attenuated
vaccines continued with the work of Li et al. (Li et al. 2015 ), who deleted esrB,
esaC, evpH, rpoS and purA genes thereby establishing 5 double- and 3 triple gene
mutants, which were markedly less virulent in blue gourami ( Trichogaster trichopterus ). Delta aroA Delta esrB mutant led to the highest RPS of 82.6 %, and thus was
evaluated by immersion or i.m. injection in fl ounder ( Paralichthys olivaceus ) leading to persistence in the animals for 14–35 days with higher antibody titres compared with the controls. After challenge, the i.m. and immersion vaccinated fi sh
achieved RPS values of 14.3–66.7 % and 100 %, respectively, pointing to the value
of live attenuated vaccines for the control of edwardsiellosis (Li et al. 2015 ). Work
has been carried out to determine the host response to administered live attenuated
cells. Thus using zebra fi sh as a model, Yang et al. ( 2013 ) During the immunization
phase, the toll-like receptor (TLR) 5 signaling and the MHC-I antigen processing
pathways and cytotoxic T-lymphocyte responses were activated, in succession.
Edwardsiella tarda
formalin- inactivated whole cells of atypical Edw. tarda, administered intraperitoneally without or without oily adjuvant, to protect red sea bream. Following the i.m.
injection of 10 mg amounts of formalised cells/100 g of Japanese eels and a booster
after 7 days, an oral challenge resulted in 60–87.5 % mortalities in the vaccinates,
compared to 80–100 % deaths among controls (Gutierrez and Miyazaki 1994 ).
Rather better protection resulted from use 1 mg of LPS/100 g body weight of
Japanese eels. With this vaccine, 40–57 % mortalities were recorded compared to
80–90 % of the controls (Gutierrez and Miyazaki 1994 ). Oral vaccination at an
equivalent of 5 × 10
8 cells/fi sh/day for two 5-day periods separated by 2 weeks using
ghost cells, which were produced from lysed cultures with the lysis plasmid pλ PR
cI-Elysis, protected olive fl ounder ( Paralichthys olivaceus ) (Kwon et al. 2007 ).
ECPs have been found to modulate innate immunity, and may well become a candidate for future vaccine studies (Lee et al. 2007).
Unfortunately, Mekuchi et al. 1995b ) did not fi nd any clear sign of protection in
Japanese fl ounder, that had been vaccinated with formalised cells via the i.m., oral
or immersion routes. Other work has doubted the importance of cell-mediated
immunity in the protection of fi sh against disease (Miyazaki and Egusa 1976 ). This
is perhaps surprising in view of the current opinions concerning fi sh immunology.
Intramuscular injection of eels and red sea bream with LPS resulted in protection
from challenge with a virulent culture of Edw. tarda (Salati et al. 1987a , b ).
Moreover, there was a demonstrable humoral immune response (titre = 1:2048) and
phagocytosis by T-lymphocytes. Phagocytic activity in the eels peaked 3 weeks
after vaccination (Kusuda and Taira 1990 ). Indeed, the evidence showed that LPS
was much more successful as an immunogen than vaccination with a formalised
culture (Salati et al. 1987a , b ).
Igarashi and Iida ( 2002 ) used live attenuated and formalin-inactivated cells of a
mutant, SPM31, constructed with transposon Tn5 with reduced siderophore producing capability. Tilapia were vaccinated intraperitoneally (0.1 mg of vaccine/100 g
of fi sh) whereupon antibodies were produced and protection recorded after challenge for the live (0 % mortality) but not the formalin-inactivated (mortality = 80–100 %) preparation (Igarashi and Iida 2002 ). Interest in live attenuated
vaccines continued with the work of Li et al. (Li et al. 2015 ), who deleted esrB,
esaC, evpH, rpoS and purA genes thereby establishing 5 double- and 3 triple gene
mutants, which were markedly less virulent in blue gourami ( Trichogaster trichopterus ). Delta aroA Delta esrB mutant led to the highest RPS of 82.6 %, and thus was
evaluated by immersion or i.m. injection in fl ounder ( Paralichthys olivaceus ) leading to persistence in the animals for 14–35 days with higher antibody titres compared with the controls. After challenge, the i.m. and immersion vaccinated fi sh
achieved RPS values of 14.3–66.7 % and 100 %, respectively, pointing to the value
of live attenuated vaccines for the control of edwardsiellosis (Li et al. 2015 ). Work
has been carried out to determine the host response to administered live attenuated
cells. Thus using zebra fi sh as a model, Yang et al. ( 2013 ) During the immunization
phase, the toll-like receptor (TLR) 5 signaling and the MHC-I antigen processing
pathways and cytotoxic T-lymphocyte responses were activated, in succession.
Edwardsiella tarda