491
Disease Control
Vaccine Development Formalin inactivated cells administered in oily adjuvant,
i.e. Montanide-ISA711 or Montanide-ISA763A, or saline to ayu followed by challenge after 22 and 52 days led to reasonable to excellent protection. Thus, the RPS
for the Montanide-ISA711, Montanide-ISA763A and saline vaccines were
17–58 %, 57–92 % and 65–86 %, respectively (Ninomiya and Yamamoto 2001 ). An
acetone- killed (37 °C for 2 h), dehydrated oral whole cell vaccine was developed
and fed to ayu at 2 week intervals before challenge (RPS = 40–79 %) (Kintsuji et al.
2006 ).
Biological Control Two lytic bacteriophage – Podoviridae PPp-W4 and
Myoviridae PppW-3 –, which were recovered from diseased ayu and pond water
used to rear fi sh (Park et al. 2000 ) have been considered for use against Ps. plecoglossicida in ayu (Park and Nakai 2003 ). In in vitro work, PPp-W4 was the more
successful at inhibiting the pathogen. In fi sh experiments involving challenge with
feed supplemented with Ps. plecoglossicida at 10
7 CFU/fi sh followed by use of feed
containing bacteriophage (10
7 PFU/fi sh), the resulting mortalities were greatly
reduced. Thus, by use of groups with PPp-W3, PPp-W4 and a mixture of both,
mortalities of 53, 40 and 20 % were recorded compared to 93 % mortalities among
the controls (Park and Nakai 2003 ). Field trials were equally successfully, and there
was no evidence for the development of bacteriophage resistance by Ps. plecoglossicida (Park and Nakai 2003 ).
Pseudomonas pseudoalcaligenes
Characteristics of the Disease
During 1992 at a site in the UK, rainbow trout (average weight = 100 g) were
observed with extensive skin lesions and signs of ERM (from which Yersinia ruckeri was recovered). The fi sh displayed extensive skin lesions, which extended over
the entire fl ank from the operculum to the tail. The skin and underlying muscle to a
depth of approximately 1 mm were totally eroded (Austin and Stobie 1992 ).
Isolation
Ps. pseudoalcaligenes was recovered as mixed cultures with Serratia plymuthica
from the ascitic fl uid and surface lesions following incubation on TSA at 22 °C for
3–4 days (Austin and Stobie 1992 ).
Pseudomonas pseudoalcaligenes
Disease Control
Vaccine Development Formalin inactivated cells administered in oily adjuvant,
i.e. Montanide-ISA711 or Montanide-ISA763A, or saline to ayu followed by challenge after 22 and 52 days led to reasonable to excellent protection. Thus, the RPS
for the Montanide-ISA711, Montanide-ISA763A and saline vaccines were
17–58 %, 57–92 % and 65–86 %, respectively (Ninomiya and Yamamoto 2001 ). An
acetone- killed (37 °C for 2 h), dehydrated oral whole cell vaccine was developed
and fed to ayu at 2 week intervals before challenge (RPS = 40–79 %) (Kintsuji et al.
2006 ).
Biological Control Two lytic bacteriophage – Podoviridae PPp-W4 and
Myoviridae PppW-3 –, which were recovered from diseased ayu and pond water
used to rear fi sh (Park et al. 2000 ) have been considered for use against Ps. plecoglossicida in ayu (Park and Nakai 2003 ). In in vitro work, PPp-W4 was the more
successful at inhibiting the pathogen. In fi sh experiments involving challenge with
feed supplemented with Ps. plecoglossicida at 10
7 CFU/fi sh followed by use of feed
containing bacteriophage (10
7 PFU/fi sh), the resulting mortalities were greatly
reduced. Thus, by use of groups with PPp-W3, PPp-W4 and a mixture of both,
mortalities of 53, 40 and 20 % were recorded compared to 93 % mortalities among
the controls (Park and Nakai 2003 ). Field trials were equally successfully, and there
was no evidence for the development of bacteriophage resistance by Ps. plecoglossicida (Park and Nakai 2003 ).
Pseudomonas pseudoalcaligenes
Characteristics of the Disease
During 1992 at a site in the UK, rainbow trout (average weight = 100 g) were
observed with extensive skin lesions and signs of ERM (from which Yersinia ruckeri was recovered). The fi sh displayed extensive skin lesions, which extended over
the entire fl ank from the operculum to the tail. The skin and underlying muscle to a
depth of approximately 1 mm were totally eroded (Austin and Stobie 1992 ).
Isolation
Ps. pseudoalcaligenes was recovered as mixed cultures with Serratia plymuthica
from the ascitic fl uid and surface lesions following incubation on TSA at 22 °C for
3–4 days (Austin and Stobie 1992 ).
Pseudomonas pseudoalcaligenes