Download Impact of dissolved oxygen on vaccine efficacy of vaccinated

Possibility of disease control by
ambient dissolved oxygen level
Masashi Maita
Tokyo University of Marine Science and Technology
Japan
Counter measures against infectious diseases
in Aquaculture
Food safety issues by drug residues
Chemotherapy
Vaccination
Probiotics
Feed additives
Concept of disease outbreaks
in farmed fish
Host
Vaccination
Feed additives
Probiotics
Etiologic agent
Environment
DO levels
Disease outbreaks
(Snieszko, 1974)
Hypoxia and infectious diseases
• Hypoxia (including Low Oxygen
uptake by gill damage) are
extremely common in
aquaculture systems.
• Low dissolved oxygen in water
has brought high mortality due
to infectious diseases.
(Fukuda et al. 1997; Walter &
Plumb 1980; Mqolomba &
Plumb 1992; Caldwell &
Hinshaw 1995).
Author and year
Finding
Fukuda, Maita
et al. 1997
Influence of dissolved oxygen concentration on mortality of
yellowtail experimentally infected with Enterococcus seriolicida
Scapigliati et
al.,1999
Hyperoxygenation of sea water resulted in a two-fold increase
of immunoglobulins of sea bass compared to running seawater.
Barton, 2000
Hypoxia is strong enough to alter homeostatsis of fish, more
energy in fish body might be allocated for maintain integrity
and less will be remain for immunity
Boleza et
al.,2001
Hypercapnic hypoxia compromises bactericidal activity of fish
anterior kidney cells against opportunistic environmental
pathogens
Cecchini and
Saroglia, 2002
Specific antibody response of sea bass against human-γglobulin was reduced after hypoxia exposure than fish in
hyperoxia or normoxia
Welker et al.,
2007
Sub lethal hypoxia compromises immune response of channel
cat fish and increase susceptibility to Enteric septicemia
Choi et al., 2007 Acute hypoxia compromises immunity of fish
In human, it is well known that the oxygen-dependent
bactericidal activity plays an important role to protect from
bacterial infection (Johnston et al. 1975) and decreased
environmental oxygen inhibits the NBT reduction activity,
production of reactive oxygen species and the respiratory burst
of leukocytes (Jarstrand et al. 1989; Gabig et al. 1979).
Objective of this study
To investigate the effects of Hypoxia , Hypoxia –reperfusion on
mortality and immune response in fish and find the possibility of
disease control by ambient oxygen management.
Notify:
In this study Hypoxia is defined as “low oxygen level
(50% DO saturation) where no physiological or
behavioral changes could observe”
HDO tank
LDO tank
110~120% DO-saturation
40~50% DO-saturation
Challenged with
pathogens
Challenged fish and non-challenged fish were cohabited in
same tank.
Cumulative mortality (%)
110~120% DO-saturation
40~50% DO-saturation
c
20
c
15
b
10
5
0
a
Non-challenge Challenge
In HDO
In HDO
Challenge
In LDO
Non-challenge
In LDO
 Mortality due to experimental challenge in LDO was
significantly higher.
 Horizontal transmission was easy to occur in
moderate hypoxic condition.
110~120% DO-saturation
40~50% DO-saturation
All groups of fish were
challenged with pathogens
H-H
L-H
H-L
L-L
L-L: ■
H-L: ●
L-H：□
H-H: 〇
Mortality of infected fish that were transferred to the
hyperoxic condition were significantly lowered.
Infected fish reared in hypoxic condition would cause high
mortality but the mortality could lowered by transfer to
hyperoxic condition.
HDO tank
LDO tank
110~120% DO-saturation
Decrease 40-50%
saturation
40~50% DO-saturation
Challenged with
pathogens
Increase 40-50%
saturation
Both group of fish were reared at normoxic tank (80~90%
saturation).
Survival rate （％）
100
80
Control
60
LDO before
challenge
HDO before
challenge
40
20
0
0
5
10
Days after challenge
If the dissolved oxygen level after infection maintain higher
than acclimated level, the mortality could be decreased.
Partial pressure of venous blood oxygen
tension (mmHg)
60
50
40
30
HDO
LDO
20
10
0
0
10
20
30
40
50
Days
The partial pressure of venous blood were decreased by
hypoxic condition and were acclimated by 2 weeks.
Phagocytic activity
In HKL
100
(%)
80
60
40
20
0
HDO
LDO
**
0.1
Reactive oxygen
production in HKL
(O.D. at 540 nm)
0.08
0.06
0.04
0.02
0
HDO
LDO
The partial pressure of venous
blood oxygen (mmHg)
70
60
50
control
LDO
40
30
20
10
0
0
10
20
30
Days
40
50
Cumulative mortality of rainbow trout challenged with Vibrio
anguillarum
100
Cumulative mortality (%)
LDO→HDO
LDO→LDO
80
control
60
*
40
20
0
0
5
Days after the challenge
10
Recommendation
• The dissolved oxygen levels in rearing water should
monitor frequently to know the oxygen levels that fish
are acclimated.
• If a few diseased fish are found, oxygen should be
supply into the water.
Awaiting solution
• Optimum farm management procedure on dissolved
oxygen should be established.
• Suitable equipment of oxygen supply should be
developed.
Practical use of oxygen generator